The study examined cervical cancer, HPV-associated cancers outside the cervix in females, and HPV-associated cancers in males. For females, researchers characterized relative burden patterns using country-specific ratios of age-standardised incidence rates and a quartile-based classification. They also evaluated associations between incidence rates and the Human Development Index, using data for 2022 to compare the geographic distribution of these cancers.

In 24 countries and territories, the age-standardised incidence rate of female non-cervical HPV-associated cancers exceeded that of cervical cancer. The analysis found contrasting development gradients: cervical cancer incidence was inversely associated with HDI, whereas female non-cervical and male HPV-associated cancer incidence showed positive associations with HDI. The relationships for cervical cancer and female non-cervical HPV-associated cancers were nonlinear, indicating that the association between national development and incidence was not uniform across all development levels.

Historical data from Cancer Incidence in Five Continents Plus were used to examine changes in 40 countries between 1998 and 2017. Joinpoint regression showed that cervical cancer age-standardised incidence decreased in 23 of the 40 countries. By contrast, incidence increased in 23 countries for female non-cervical HPV-associated cancers and in 13 countries for male HPV-associated cancers. These temporal results describe the study population of countries with available data, rather than every country worldwide.

The analysis also tested whether the time elapsed since HPV vaccine introduction into national immunisation programmes was associated with incidence rates in 2022. An inverse association was observed between years since vaccine introduction and cervical cancer incidence. That association was no longer statistically significant after adjustment for cervical screening coverage, with an adjusted coefficient of β = −0.19 and P = 0.537.

The positive association between years since HPV vaccine introduction and female non-cervical HPV-associated cancer incidence was attenuated after adjustment for HDI, but remained statistically significant, with β = 0.11 and P = 0.022. These analyses were ecological, so the results identify population-level associations between vaccination timing and incidence rather than demonstrating a causal effect of vaccination on an individual or establishing benefits from the vaccine itself.

Taken together, the findings show that the global burden of HPV-associated cancer does not follow one geographic pattern. Cervical cancer remained a major burden in low-HDI countries, while non-cervical HPV-associated cancers were increasingly prominent in many higher-HDI settings. The historical analysis also documented declines in cervical cancer in most of the 40 countries with usable time-series data, alongside increases in female non-cervical HPV-associated cancers in the same number of countries and male HPV-associated cancers in 13.

The authors concluded that future strategies should be tailored to local epidemiological contexts, with gender-neutral HPV vaccination considered where appropriate alongside integrated management of shared behavioural risk factors. Their conclusions are based on modelled global estimates for 2022, historical incidence data from a limited group of countries, and observational associations. As a result, the study supports context-specific planning rather than a single universal interpretation of HPV-associated cancer trends.

Subject of Research: Global epidemiology of cervical and non-cervical HPV-associated cancers

Article Title: The global landscape of HPV-associated cancers beyond the cervix: a comparative epidemiological analysis

Article References: Zhong, P., Zhang, X., Hu, S., Zhao, X., Xia, C., Yang, H., Stafford, R. S., Zhao, F., & Zhang, L. (2026). The global landscape of HPV-associated cancers beyond the cervix: a comparative epidemiological analysis. BMC Infectious Diseases. https://doi.org/10.1186/s12879-026-14563-1

Image Credits: AI Generated

DOI: 10.1186/s12879-026-14563-1

Keywords: HPV, cervical cancer, global epidemiology, cancer incidence, HPV vaccination, human development, cervical screening, anal cancer, oropharyngeal cancer, health inequality, global, landscape

The researchers used human GENCODE version 38 annotations as the reference and applied TOGA, a tool for inferring orthologs from genome alignments, to compare genes across 462 placental mammals. TOGA identified disruptive mutations including frameshifts, premature stop codons, splice-site disruptions and larger deletions. A gene was classified as lost when its intact reading frame was absent in a species and all corresponding transcripts met the criteria for loss. Across the dataset, each gene had a median of 18 loss events, while each species had a median of 1,130 likely gene-loss events. Only six genes had no observed loss across the complete mammalian sample: NAP1L1, ZC3H14, MEIS2, STRIP1, CCT5 and ATP6V0D1.

GISMO was designed as a weighted estimate of the proportion of species in which a gene has been lost. Each loss is weighted according to evolutionary distance from humans, so losses in more distantly related species contribute more heavily. A lower score indicates that a gene is rarely lost and is therefore more constrained across the sampled mammals. The researchers also examined a phylogenetically adjusted version, which was strongly correlated with the regular score, but the nonphylogenetic version showed stronger empirical associations with independent constraint measures. They attributed some of this performance to TOGA’s requirement for multiple disruptions in an open reading frame before classifying a gene as lost, which can reduce the risk of counting a single questionable disruption as a loss event. The metric covered 97.7% of genes in GENCODE version 38, the highest proportion among the conservation scores benchmarked in the study.

The second measure, GISMO-mis, captures a different aspect of constraint. For each gene, the researchers generated a mammalian consensus sequence and counted missense and synonymous differences in each species relative to that consensus. They then calculated the mean missense-to-synonymous ratio across available species. A lower ratio indicates that amino-acid-changing substitutions are relatively depleted compared with synonymous changes, consistent with stronger functional constraint at the protein level. Codon alignments were included when a gene had a single ortholog in at least 75% of queried species; species with more than four predicted orthologs were excluded. The method extends the logic of the missense-to-synonymous substitution ratio by using a multi-species consensus and by handling ambiguous alignments conservatively.

Tests against independent gene sets showed that the most constrained deciles were enriched for genes whose disruption causes early lethality in mice or loss of viability in cell lines. For mouse heterozygous knockouts, the odds ratios were 3.43 for GISMO and 5.78 for GISMO-mis. The corresponding values for homozygous knockouts were 8.21 and 13.1, while essential cell-line genes had odds ratios of 4.34 and 10.70. By contrast, the least constrained deciles contained the greatest proportions of genes classified as nonessential or associated with olfaction. Frequently lost genes also tended to be expressed in fewer tissues in the GTEx dataset, with expression defined as more than 0.3 transcripts per million. The distributions of GISMO scores did not drift as gene-family size increased, indicating no observed association with that feature in the benchmarked data.

Both measures were correlated with human constraint estimates derived from large-scale sequencing data. GISMO correlated with the gnomAD LOEUF score at Spearman’s R of 0.38, while GISMO-mis reached R of 0.56, with both P values below 1 × 10−300. GISMO-mis also correlated with the missense constraint score MOEUF at R of 0.61 and with the predicted missense effect metric AlphaMissense at R of 0.84. Both measures were associated with haploinsufficiency and triplosensitivity scores, while GISMO-mis had stronger correlations than GISMO for each dosage measure. In a UK Biobank copy-number-variant dataset generated from exome sequencing in 197,306 people, the most constrained deciles of both metrics had the fewest deletions and duplications. GISMO showed an even stronger correlation with deletions than pHaplo, a dosage-sensitivity metric derived from lower-resolution microarray data across about one million human samples. These results establish associations with independent measures of constraint, rather than showing that the scores are interchangeable.

A major difference from LOEUF was the reduced sensitivity of the mammalian measures to coding-sequence length. LOEUF was strongly correlated with coding-sequence length at R of −0.50, whereas the correlations for GISMO and GISMO-mis were each −0.12. When the researchers defined intolerance as the most constrained 15% of genes, GISMO identified 2,897 genes with a median coding-sequence length of 1,502 base pairs, and GISMO-mis identified 2,502 with a median of 1,302 base pairs. LOEUF identified 2,968 intolerant genes with a longer median of 2,267 base pairs. Genes considered intolerant by GISMO or GISMO-mis but tolerant by LOEUF were enriched in mouse phenotypes involving sperm immotility, absence of the acrosome and abnormal actin cytoskeleton morphology. The analysis was comparative and computational, so these enrichments identify previously unclassified constrained genes for further study rather than demonstrating human clinical outcomes.

The study also examined whether the evolutionary measures captured disease-associated genetic signals. Using linkage disequilibrium score regression, the researchers partitioned common-variant heritability across 276 independent UK Biobank traits and several additional disease phenotypes. Heritability showed a strong linear enrichment across the constraint deciles of both GISMO and GISMO-mis and was lowest in the least constrained deciles, with consistent results at 10-, 50- and 100-kilobase flanking windows. Genes in the most constrained deciles also showed stronger associations with rare variants linked to reduced fecundity, including schizophrenia, autism and neurodevelopmental disorders. The findings indicate that deeply conserved genes contribute disproportionately to both common- and rare-variant signals in these phenotypes, but they do not establish that conservation itself causes the associations. The researchers also found that genes with high LOEUF constraint but low GISMO conservation were disproportionately X-linked, raising the possibility of differences related to hemizygosity, sex-biased selection or technical challenges in short-read variant detection; this discordant subset was not enriched for Mendelian disease genes or essential phenotypes when restricted to the X chromosome.

GISMO had a distinct association with recessive disease genes because gene loss across species can reflect selection against homozygous loss-of-function alleles. In a set of 1,183 autosomal recessive genes assembled from OMIM, the most constrained GISMO deciles were enriched with an odds ratio of 3.37 and a 95% confidence interval of 2.91 to 3.89. GISMO-mis did not show significant enrichment for this set, with an odds ratio of 0.91 and P = 0.41. Both measures were enriched for 709 dominant disorder genes: the odds ratio was 9.92 for GISMO and 4.38 for GISMO-mis. In the Deciphering Developmental Disorders study of about 14,000 trios, GISMO distributions for recessive developmental-disorder genes with confident or strong evidence were similar to those of Mendelian recessive genes, whereas genes with limited or moderate evidence were unclear. The authors described GISMO and GISMO-mis as complementary: GISMO emphasizes disruption of an entire gene across species, while GISMO-mis emphasizes amino-acid-level constraint. They recommend using the continuous scores where possible and calibrating categorical thresholds against relevant gene sets such as ClinGen annotations, mouse knockout phenotypes or disease-gene catalogs.

Several limitations constrain the interpretation and future refinement of the results. Mammalian conservation may not reflect recent human selective pressures or human-specific innovations, and a gene tolerated in other mammals may nevertheless be essential in humans. The available species may also introduce survivorship and accessibility biases, so broader taxonomic sampling could improve the metrics. GISMO combines signals associated with heterozygous and homozygous selection and therefore does not distinguish between them by itself; pairing it with LOEUF and GISMO-mis can help separate those relationships. Although the nonphylogenetic version of GISMO does not distinguish multiple independent losses from one ancestral loss, it performed better against independent measures of functional constraint than the phylogenetic alternative, and a phylogenetic version was also released. Recent human-specific duplications showed a slight correlation with the conservation score of the original paralog, but such cases were few. Overall, the analyses support gene loss and missense fixation across mammals as measurable signals of selection and show that these scores can rank gene importance, inform disease-gene prioritization and provide evolutionary evidence alongside variation in modern human populations.

Subject of Research: Evolutionary constraint and gene essentiality across 462 placental mammals

Article Title: The landscape of gene loss and missense variation across the mammalian tree informs on gene essentiality

Article References: Liao, C., Ye, R., Ivankovic, F., Fu, J. M., Walters, R., Lowther, C., Valkanas, E., Churchhouse, C., Samocha, K. E., Lindblad-Toh, K., Karlsson, E., Hiller, M., Talkowski, M. E., & Neale, B. M. (2026). The landscape of gene loss and missense variation across the mammalian tree informs on gene essentiality. Nature Genetics. https://doi.org/10.1038/s41588-026-02783-9

Image Credits: AI Generated

DOI: 10.1038/s41588-026-02783-9

Keywords: comparative genomics, gene essentiality, mammalian evolution, gene loss, missense variation, evolutionary constraint, disease-gene prioritization, rare variants, common-variant heritability, copy-number variation, landscape, gene

The study, published in the journal Metabarcoding and Metagenomics as part of the Horizon Europe project eDNAqua-Plan, took an unusually comprehensive look at how eDNA data are generated, archived and shared across the continent. Rather than relying on a single method, the team combined four complementary approaches: a qualitative evaluation of the major databases that store eDNA records, a quantitative audit of metadata completeness, a questionnaire survey of 69 researchers from 29 countries, and a large-scale analysis of more than 1,600 scientific publications using a fine-tuned large language model. The verdict is stark. While some repositories demonstrate strong curation and accessibility, others lack essential metadata descriptors, and the gaps are heavily concentrated in exactly the areas that determine whether data can ever be reused.

The technical core of the problem lies in metadata, the structured information that describes how each sample was collected, processed and sequenced. Without knowing the filter pore size used to capture DNA particles, the volume of water extracted, the primers deployed during PCR amplification, or the bioinformatic pipeline applied to the raw reads, a downstream user cannot meaningfully compare one dataset with another. The international standards designed to solve this exist. The Genomic Standards Consortium’s MIxS framework defines mandatory and recommended metadata terms for sequence submissions, including a Water extension with fields such as size_frac_low and samp_vol_we_dna_ext. The Darwin Core standard underpins biodiversity platforms like GBIF and OBIS. Yet the audit of 5,280 European aquatic eDNA sample accessions in the European Nucleotide Archive revealed that these standards are being applied only patchily.

The numbers are remarkable. Although every retrieved sample carried the mandatory environmental context fields, Environment Ontology terms appeared in only about 18 percent of entries. The sample collection method was provided in fewer than 20 percent of records, and the size fraction used for pre-filtration in just 13.5 percent. The volume or mass of sample used for DNA extraction was reported in a mere 1.5 percent of cases, and the nucleic acid extraction method in 2 percent. PCR primers, a critical determinant of taxonomic coverage and amplification bias, were given for 23 percent of records, while the target gene fragment appeared in only 2 percent. Even the MIxS term nucl_acid_ext, designed specifically to hold extraction protocol information, did not appear in a single record. In practice, much of the metadata that does exist was submitted as inconsistent free text rather than standardised values, forcing anyone hoping to harmonise the data into laborious manual curation.

The questionnaire survey exposed a second, more troubling layer to the problem: a significant gap between what researchers believe they are doing and what the repositories actually record. Respondents reported higher compliance with metadata submission practices than the automated audit revealed. Sampling methods were reported by 59 percent of survey participants and DNA extraction protocols by 51 percent, yet the actual BioSample records showed far lower volumes of reported metadata. The authors attribute this mismatch to a combination of survey biases, including self-selection of more engaged respondents and social desirability bias, alongside structural factors such as misperceptions of the full scope of metadata requirements, lack of training, the complexity of submission systems, time constraints and limited incentives or enforcement.

The large language model analysis added a third dimension by revealing how these weaknesses recur across the literature itself. The team assembled 117 manually curated publications as a training set, then used a fine-tuned Llama 2 model to automatically extract methodological information from an expanded corpus of 1,607 eDNA papers, achieving validation accuracy of 97 to 99 percent. The synthesis showed a strong concentration of studies around a limited set of genetic markers, with the mitochondrial COI marker most frequently reported at 19 percent, followed by 16S rRNA at 17 percent and ITS at 14.5 percent. GenBank dominated as the reference database for taxonomic assignment, cited in 19.7 percent of papers where the model could infer one, with SILVA at 18.3 percent and BOLD at 9.9 percent. But the most striking finding concerned protocol transparency: of 1,440 publications for which methodological information could be inferred, only six, or 0.4 percent, cited experimental protocols deposited in protocols.io, and none of those protocol DOIs appeared in the formal reference sections of the papers.

Geographic disparities compound the technical gaps. Analysis of European aquatic eDNA sequence records in the International Nucleotide Sequence Database Collaboration, which comprises ENA, NCBI and the DNA Data Bank of Japan, revealed that records are heavily concentrated in Northern and Western European countries, while Eastern and Southeastern Europe contribute substantially fewer. The imbalance reflects not just differences in sequencing volume but disparities in project-level participation, suggesting that in some regions DNA research activity exists but projects are smaller in scale or involve lower sequencing intensity. Meanwhile, the mobilisation of processed eDNA-derived biodiversity data into secondary platforms remains limited: only 25 datasets in OBIS contained the DNA-derived data extension from European marine waters, and just 15 percent of questionnaire respondents reported submitting such data to biodiversity portals.

The way forward, the authors argue, lies in a structured framework combining three complementary sets of principles. The FAIR principles, ensuring data are Findable, Accessible, Interoperable and Reusable, form the technical foundation, drawing on Darwin Core and MIxS standards alongside GBIF guidelines for publishing DNA-derived data. The CARE principles, emphasising Collective benefit, Authority to control, Responsibility and Ethics, address Indigenous data governance and responsible sample stewardship. The TRUST principles, covering Transparency, Responsibility, User focus, Sustainability and Technology, provide criteria for repository reliability and long-term digital preservation. Recent work by Takahashi and colleagues on Making eDNA FAIR has already produced a comprehensive metadata checklist integrating these standards with new terms tailored specifically to eDNA workflows, and core terms of MIxS and Darwin Core have been mapped to improve interoperability between the sequence and biodiversity data infrastructures.

Importantly, the authors stress that standardisation does not imply a single universal eDNA protocol. Rather, it entails a portfolio of context-dependent, transparent and well-documented methodological approaches that are comparable because they adhere to shared reporting principles. PCR conditions and primer sequences should be consistently reported, as they are a critical determinant of taxonomic coverage and amplification bias. The cost of poor metadata standardisation, in terms of wasted research investment, duplicated efforts and reduced funding efficiency, was not quantified in this study, but the authors describe it as a substantial hidden burden on the research ecosystem.

As Europe moves toward coordinated aquatic biodiversity monitoring at scale, the message from this assessment is unambiguous. eDNA can become a cornerstone of conservation strategy, environmental policy and rigorous evaluation of restoration interventions, but only if the data infrastructure catches up with the science. Coordinated efforts between field and laboratory method experts, data custodians and policymakers are essential to embed minimum metadata requirements into harmonised reporting frameworks, ensuring that high-quality metadata becomes a natural outcome of methodological compliance rather than an afterthought. The technology is ready. The question now is whether the community can align its incentives, training and repositories to make every eDNA dataset as reusable as the science it enables.

Subject of Research: Navigating the European aquatic eDNA landscape: Opportunities for metadata standardisation and data mobilisation

Article Title: Navigating the European aquatic eDNA landscape: Opportunities for metadata standardisation and data mobilisation

Article References: Kavakiotis, I., Woollard, P., Babo, C., Egge, E., Krawczyk, D., Laamanen, T., Paupério, J., Bacela-Spychalska, K., Pade, N., Costa, F. O., Grabowski, M., Norros, V., Meissner, K., & Papakostas, S. (2026). Navigating the European aquatic eDNA landscape: Opportunities for metadata standardisation and data mobilisation. Metabarcoding and Metagenomics, 10, Article e173612. https://doi.org/10.3897/mbmg.10.173612

Image Credits: AI Generated

DOI: 10.3897/mbmg.10.173612

Keywords: Navigating, European, aquatic, eDNA, landscape, Opportunities, metadata, standardisation, data, mobilisation, scientific research

The Olentangy River is an ideal natural laboratory for this kind of work because it performs a complete land-use transformation within a single watershed. Covering 1,370 square kilometers of central Ohio, the river begins in row-crop farmland to the north, passes through a 35-kilometer stretch designated a Scenic River for its undisturbed riparian buffer, and then plunges into metropolitan Columbus, the fourteenth-largest city in the United States with a population density of roughly 1,400 people per square kilometer. The researchers sampled the river and two outfalls on the university campus between November 2021 and November 2022, collecting water weekly or biweekly. The Big Outfall drains a broad network extending into Columbus’ combined sewer system, fed by campus runoff, sanitary sewer overflows, and combined sewer overflows. The Small Outfall, just thirty meters downstream, drains a smaller campus network centered on parking lots around Ohio Stadium, a parking garage, and academic buildings.

The analytical results were unambiguous. Chloride concentrations in the outfalls ranged from less than 150 to more than 3,400 micromolar, and in the Small Outfall, 69 percent of samples exceeded the Environmental Protection Agency’s chronic threshold for aquatic life of 6,488 micromolar. The outfall waters also carried elevated sodium, potassium, magnesium, calcium, sulfate, and dissolved silica compared with the river itself. Mean calcium concentrations in the two outfalls were around 2,238 and 2,294 micromolar, well above the river’s mean of 1,432 micromolar. Sulfate means were similarly elevated, at 1,220 and 1,475 micromolar in the outfalls versus 548 micromolar in the river, while dissolved silica averaged 148 and 134 micromolar in the outfalls against just 88 micromolar in the river. Interestingly, the pattern reversed for nutrients: the Olentangy typically carried greater nitrate and soluble reactive phosphorus concentrations than the outfalls, a fingerprint of the agricultural headwaters upstream.

To trace where all those ions were coming from, the team deployed a geochemical detective kit. Chloride-to-bromide ratios, which ranged from roughly 1,100 to 7,000 in the outfalls, pointed squarely at road salt, since halite formed by evaporation preferentially excludes bromide and carries a characteristically high ratio. Winter samples showed the greatest ratios, matching the deicing season. The Small Outfall’s chloride dominance persisted well beyond the typical November-to-March application window, evidence that salt stored in soils and shallow groundwater continues to leach for months. Previous research has shown road salt signatures in storm drain effluent up to seven months after the last application, and the Columbus data reinforce that persistence. Sodium-to-chloride ratios in the outfalls were enriched in chloride, consistent with sodium undergoing cation exchange with potassium, calcium, and magnesium on soils and sediments as chloride moves conservatively through the environment.

But road salt is only one ingredient in what urban geochemists have come to call chemical cocktails. The potassium story led the researchers to municipal water treatment. The mean potassium concentration in the Small Outfall, 123 micromolar, sat squarely within the range measured in Columbus’ three municipal water plants, where potassium is added as a water softener. Sodium carbonate is dosed to soften water naturally high in calcium and magnesium from limestone weathering, alum serves as a coagulant, and fluoride is added for dental health. Mean fluoride concentrations were greater in the outfalls than in the river, a telltale sign that treated municipal water leaks into the storm system. Notably, the Big Outfall and the urban river showed potassium patterns driven more by seasonal baseflow and by weathering of Devonian-age shale and carbonate bedrock than by sewage, since the three ions lacked the correlations that a sewage source would produce.

Perhaps the most surprising source was the infrastructure itself. Concrete pipes, through which nearly all this water flows, are actively dissolving. Concrete paste is composed of roughly 60 percent calcium silicate hydrates, 25 percent portlandite, and 15 percent ettringite, with gypsum frequently added to slow hydration. As urban water percolates through these networks, it weathers the pipe walls, releasing calcium, potassium, bicarbonate, sulfate, and silica into the dissolved load. The statistical fingerprints were compelling: in both outfalls, calcium showed robust, significant correlations with sulfate, dissolved silica, magnesium, and potassium, with coefficients reaching 0.97 between calcium and sulfate in the Small Outfall. Those same correlations were weak or absent in the Olentangy River, indicating that pipe weathering exerts its strongest control inside the subsurface system before the water reaches the river. The researchers argue that concrete drainage infrastructure should be viewed as an impervious surface in its own right, one that interacts chemically with every drop it conveys.

Stable water isotopes added a temporal dimension to the picture. The mean δ18O and δ2H values of the Olentangy River, Big Outfall, and Small Outfall were −6.66, −7.20, and −7.35 per mil, and −42.3, −46.5, and −47.4 per mil, respectively, closely matching the mean weighted annual precipitation composition of −7.40 and −48.2 per mil. Yet 74 percent of Big Outfall samples and 84 percent of Small Outfall samples fell outside instrument uncertainty when compared with the river, showing that the pipe water is more responsive to recent precipitation than the river itself. After a large, isotopically depleted storm on May 27, the outfalls displayed depleted signatures within hours, indicating rapid flushing of event water through the urban karst. During most of the study period, however, the consistent isotope values suggested that water in the subsurface network was well mixed, a blend of multiple precipitation events with residence times ranging from hours after major storms to days or weeks during dry periods.

All of these inputs converge on a single worrying outcome: freshwater salinization syndrome. The mean cation abundance in the urban corridor of the Olentangy shifted to calcium, sodium, magnesium, potassium, compared with calcium, magnesium, sodium, potassium in the upstream agricultural corridor, while chloride became overwhelmingly dominant among anions, averaging roughly 1,500 micromolar in the river versus 3,800 to 8,300 micromolar in the outfalls. Ternary diagrams plotting mean water compositions revealed a clear mixing line running from the agricultural river and precipitation toward urban highway runoff, with the urban Olentangy and both outfalls falling along it. This progressive enrichment in sodium and chloride, accompanied by rising calcium, magnesium, sulfate, and bicarbonate, mirrors patterns documented from Baltimore to Philadelphia and beyond, and it has consequences that reach all the way to the tap: chloride concentrations in Columbus drinking water have been observed to rise each January as road salt accumulates in the reservoirs supplying the city.

The agricultural headwaters, meanwhile, still control the river’s nutrient chemistry. Nitrate in the urban Olentangy climbed to roughly 400 micromolar in late spring and early summer, more than half of the EPA maximum contaminant level for nitrate-nitrogen in drinking water, as fertilizer applied to fields upstream was flushed into the river system. Outfall nitrate concentrations, averaging just 51 to 65 micromolar, were overwhelmed by this agricultural signal, though episodic spikes in the Small Outfall during April and August, alongside elevated soluble reactive phosphorus, hinted at campus fertilizer sources, animal waste, lawn runoff, and vehicle-related atmospheric deposition. The contrast with phosphorus is instructive: while nitrate stays dissolved, most phosphorus in urban stormwater adsorbs onto particles and iron oxyhydroxides, meaning different management strategies are needed to rein in nitrogen and phosphorus separately.

By 2050, the United Nations projects that 68 percent of the global population will live in cities, and within the United States that figure will reach 89 percent. Urban land, currently 3 percent of the American landscape, is expected to more than double by 2060. Every one of those expanding cities will build its own version of the urban karst, the fracture-like network of pipes, leaks, and conduits that turns shallow groundwater into a chemically engineered fluid. The Olentangy study demonstrates that rivers flowing from farm to city undergo a predictable geochemical evolution, their dissolved loads rewritten by road salt, water treatment chemicals, and dissolving concrete, while their nutrients remain hostage to decisions made upstream. Understanding that transformation, the authors argue, is essential for designing green infrastructure that can intercept these chemical cocktails before they reach the rivers that cities depend on for drinking water, recreation, and life itself.

Subject of Research: Geochemistry of urban waters and their evolution within the urban landscape

Article Title: Geochemistry of urban waters and their evolution within the urban landscape

Article References: Smith, D. F., Welch, S. A., Rankin, A., Carey, A. E., & Lyons, W. B. (2024). Geochemistry of urban waters and their evolution within the urban landscape. Frontiers in Geochemistry, 2, Article 1475109. https://doi.org/10.3389/fgeoc.2024.1475109

Image Credits: AI Generated

DOI: 10.3389/fgeoc.2024.1475109

Keywords: Geochemistry, urban, waters, evolution, within, landscape, scientific research

More than twenty-five years ago, Tom Seeley argued in his influential book The Wisdom of the Hive that the honey bee colony is a system complex enough to demand computer simulation if we ever hope to predict its responses to stimuli. That vision has recently gained institutional weight: the European Food Safety Authority has endorsed the development of a mechanistic colony model as the foundation for environmental risk assessment of multiple stressors to bees at the European scale. The model now under construction, called ApisRAM, uses an agent-based modelling approach in which individual bees are represented as digital agents with their own behavioural rules, interacting with each other, with the hive’s physical and chemical properties, and with the external environment. The colony-level outcomes that emerge from these interactions are not programmed in directly; they arise from the bottom up, as consequences of thousands of individual decisions.

Agent-based models of bee foraging are not new. Researchers have previously explored the metabolic costs of foraging, the exploitation of rewarding resources, the behavioural rules governing recruitment, and the feedback mechanisms that control foraging through nectar receivers. But these earlier efforts shared serious limitations. The landscapes in which model bees foraged were simplistic, often containing only a handful of food sources. Weather variables were either ignored or disconnected from the landscape representation. Crucially, none of the previous foraging models fully integrated the spatial and temporal dynamics of landscape resources, and the role of the colony itself in shaping forager numbers and behaviour was rarely considered at the individual level. Studies evaluating colony strength and production, meanwhile, seldom accounted for environmental conditions at all, typically defining landscape structure with broad land-use categories like urban, grassland, or forest, without any quantitative assessment of the resources actually available to bees.

The new foraging sub-model, developed as part of ApisRAM and described in the Food and Ecological Systems Modelling Journal, overcomes these constraints by embedding foraging bees within the Animal, Landscape and Man Simulation System, known as ALMaSS. This landscape representation typically operates on a ten by ten kilometre window at a spatial resolution of one square metre, combining detailed land-use and land-cover mapping with information on farming systems, farm practices, weather, and plant growth. Fields belong to farm units classified by type, each with associated crop rotation plans that allow realistic modelling of crop patterns changing in space and time. Country-specific management plans describe soil cultivation, fertiliser, and pesticide applications within time windows and probabilities of occurrence. Vegetation growth models supply daily biomass figures for all modelled vegetation types and crops, driven by weather conditions such as mean daily temperature.

Layered onto this dynamic landscape are floral resource models that describe pollen, nectar, and sugar production levels and their changes throughout the year for every vegetated polygon. Flowering time and resource production are tied to accumulated growing degree-days, calculated from daily average temperatures. For annual crops, degree-days accumulate from the sowing date using crop-specific thermal requirements; for other vegetated elements, the models superimpose the production of all individual plant species composing a given habitat. The result is daily information on nectar and pollen quantity in milligrams per square metre, with nectar quality defined as sugar content. When a model bee forages at a location, the foraged amount is depleted from the corresponding resource map, so the landscape genuinely responds to bee activity. Hourly weather data, including wind speed, rainfall, temperature, and solar radiation, complete the environmental picture delivered to each foraging agent.

The behavioural rules for individual model bees were defined with care. Low temperatures below ten degrees Celsius, darkness, rain, and strong winds exceeding twenty-five metres per second prevent foraging or scouting. Under favourable conditions, the possibility of flight is determined by hourly solar radiation and temperature, following an exponential equation relating the radiation threshold to ambient temperature. Each model bee has a maximum flying distance of twenty kilometres per day and can carry fifty milligrams of nectar or eight milligrams of pollen per flight, defined as a full crop. If a bee cannot fill its crop within a single square metre of a resource polygon, it performs searching flights in the surrounding square metres, up to a maximum local area of twenty-five square metres, before the flight is counted as unsuccessful. Successful bees memorise the relative position, quantity, and quality of the resources they found, and bring this information back to the colony.

The researchers then tested four distinct strategies that model bees could use when deciding where to forage. The distance strategy prioritised the closest polygons to the colony, reflecting evidence that honey bees have poor stereo vision and that smaller colonies tend to forage closer to the hive early in the season. The quality strategy, applied to nectar, prioritised polygons with the highest sugar content, drawing on the bee’s gustatory sensilla that allow rapid assessment of sugar levels. For pollen, where no single quality factor has been clearly identified, the equivalent strategy prioritised quantity. The random strategy had bees choose randomly among polygons visited during scouting trips, acknowledging that the mechanisms driving real scouting choices remain poorly understood. Finally, an energetic efficiency strategy, tested only for nectar, prioritised polygons offering the best balance between energy gained from the resource and energy spent travelling to it, calculated from sugar quantity and distance from the colony.

The simulations, run across one hundred different colony locations within a real Danish landscape near Ringkøbing and repeated to produce twelve hundred one-year simulations, yielded striking results. When scout bees applied the distance strategy, the colony collected the highest average amounts of sugar, between ninety-one and one hundred twenty-five kilograms depending on the foraging strategy, but at the cost of many daily flights with a lower success rate, and with enormous variability in outcomes. This variability revealed that distance-prioritising bees could find the most profitable foraging sites only locally, not at the landscape level, exploring habitats further afield only after the closest resources were depleted. Contrary to expectations, the energetic efficiency strategy did not deliver the highest sugar haul; bees using it performed fewer but more successful flights, most likely because a twenty-kilometre daily flight budget limited their trips. For pollen, the highest collection, between twenty-six and thirty-four kilograms on average, came when the distance strategy was used by scouts or foragers, with the unexpected best combination being distance scouting coupled with random foraging, which kept social information flowing and resources depleting slowly.

Perhaps the most important lesson concerns the scout bees, whose supposedly minor role proved decisive: the choice of scouting strategy influenced the annual resource collection of the whole colony for both nectar and pollen. The researchers conclude that foraging models must include a reliable implementation of scouting strategies, and that nectar foraging should not be determined by distance alone, since such a strategy ignores resource profitability. Future development will integrate pollen quality and diversity, refine how bees weigh private versus social information when deciding to switch foraging locations, and couple the foraging sub-model to other colony processes like food processing and brood rearing. Field-collected data from EFSA projects will be used to validate the tested strategies against real colony populations, weather, resource supply, and honey gains.

The significance of this work extends well beyond model calibration. By predicting the distribution of foraging bees and their use of resources within a dynamic landscape, the ApisRAM foraging sub-model aims to correctly predict exposure pathways to pesticides and other stressors, providing regulators with a tool that captures the feedback loops between environment and colony. The study also highlights how much fundamental behavioural knowledge is still missing, from the drivers of scouting decisions to the thresholds that cause bees to abandon known foraging sites, and makes a strong case for modern tracking technologies to fill these gaps. What emerges is a portrait of the colony as a genuinely emergent system: its success in gathering food arises not from any central plan, but from the accumulated decisions of individuals navigating a landscape that changes beneath their wings.

Subject of Research: Modelling foraging strategies of honey bees as agents in a dynamic landscape representation

Article Title: Modelling foraging strategies of honey bees as agents in a dynamic landscape representation

Article References: Capela, N., Duan, X., Ziółkowska, E., & Topping, C. J. (2024). Modelling foraging strategies of honey bees as agents in a dynamic landscape representation. Food and Ecological Systems Modelling Journal, 5, Article e99103. https://doi.org/10.3897/fmj.5.99103

Image Credits: AI Generated

DOI: 10.3897/fmj.5.99103

Keywords: Modelling, foraging, strategies, honey, bees, agents, dynamic, landscape, representation, scientific research

Aphids are the classic case. These tiny insects can reach population sizes in the billions across a landscape, and for many species the detailed individual behaviour information needed to build an agent-based model does not exist. Running billions of agents alongside the detailed predator models that depend on them, such as ladybirds hunting aphids across fields, would be either computationally ruinous or outright unfeasible. Yet aphids matter enormously, both as crop pests and as the prey base that drives predator population dynamics. A new study published in the Food and Ecological Systems Modelling Journal introduces a general subpopulation model framework that solves this problem, allowing ALMaSS to represent entire landscapes of aphids efficiently while keeping the detailed landscape simulation intact.

The key insight is that the minimal unit of simulation does not have to be the individual. Instead, the new framework divides the entire simulated landscape into a non-overlapping grid, with a default cell size of 10 metres by 10 metres. Within each grid cell, the population is managed as a stage-structured subpopulation, tracking the number of individuals at each life stage and at each age within that stage. A standard 10 kilometre by 10 kilometre landscape therefore contains one million subpopulation objects, each one a compact numerical model rather than a swarm of agents. The approach draws on the Lefkovitch stage-structured population model, which classifies individuals by characteristics such as developmental stage or reproductive status rather than chronological age alone, and associates each stage with its own transition probabilities.

What makes the framework unique, according to its developers, is the integration of three modelling traditions that are usually kept apart: stage-structured population models, spatially structured population models, and highly detailed landscape simulation. Previous aphid models have typically relied on just one of these approaches, from lattice models of carabid-aphid systems to multi-patch differential equation models of aphid and ladybird dynamics. The ALMaSS subpopulation model links its numerical population engine directly to the ALMaSS landscape simulation, which resolves the underlying topographical map at one square metre and simulates daily farm management, field operations, and plant growth. Every subpopulation therefore receives dynamic, landscape-specific information as the simulation progresses, from crop rotations to seasonal vegetation change.

The implementation is organised around two C++ classes. The Subpopulation class represents a single stage-structured subpopulation within one grid cell, while the Subpopulation_Population_Manager class administers the entire population across the landscape, initialising every cell, assigning suitability values based on habitat and crop type, and stepping the whole system forward in daily time increments. Suitability is determined by the habitat or crop type at the grid centre: if it matches a host list stored in an external text file, the suitability is set to one, otherwise zero. Arable fields are handled separately through a crop list, because their vegetation is dynamically determined by the farming simulation. When suitability drops to zero, for instance after a non-host crop is planted, the mortality function removes the entire subpopulation from that cell.

Development is driven by degree days, the accumulated physiological age that insects gain as temperatures rise above a stage-specific base temperature. Because the whole landscape shares the same weather, the manager class calculates degree days once per day for every life stage, rather than recalculating them in each of the million subpopulations. A two-dimensional array tracks accumulated degree days for each life stage and each calendar day of birth or transition, with oldest and newest indices marking where the extant population sits and where newborn individuals should be added. When a cohort accumulates enough degree days to exceed the maximum for its stage, it is flagged as ready to transition, and the subpopulation moves those individuals into the next life stage, whether that is egg to larva, larva to pupa, or pupa to adult.

Dispersal operates at two spatial scales. Short-distance movement shifts a proportion of the subpopulation to one of the eight adjacent cells, chosen randomly, but only if the destination is suitable and less crowded than the departure cell. Long-distance dispersal belongs to the winged adult stage and is modelled as partly passive flight influenced by wind. The framework pre-calculates two-dimensional landing masks for four wind directions and discrete wind speed ranges, generated from a polynomial landing curve along the wind direction. Most dispersers land near a peak distance, with a long tail out to a longest distance that scales upward as wind speed increases. Above a maximum wind speed of 12 metres per second, the model species does not attempt to fly at all. The masks are skewed using the cosine of the angle between the dispersal path and the wind direction, so more individuals land downwind and none land directly upwind, and they are normalised so their sum equals one.

Performance is the other half of the story. The three daily loops over all subpopulation objects, calling BeginStep, Step, and EndStep in sequence, are parallelised at the thread level using OpenMP. In a five-year simulation on a 10 kilometre by 10 kilometre Danish landscape, running on a single thread took 1472 seconds, while five threads cut that to 748 seconds and twenty threads brought it down to 615 seconds, a relative speed of 0.417. The gains diminish with additional threads, but the parallel design is what allows the model to handle up to one million grid cells efficiently. The developers demonstrated the framework with a hypothetical generic species parameterised purely for illustration, with five life stages spanning egg, larva, pupa, winged adult, and wingless adult, and showed that it captures annual population cycles while responding to landscape dynamics such as weather and crop variation.

The real test came with four aphid species implemented within ALMaSS: the black bean aphid Aphis fabae, the pea aphid Acyrthosiphon pisum, the peach potato aphid Myzus persicae, and the English grain aphid Sitobion avenae. Combined with an agent-based ladybird model simulating predator behaviour, the subpopulation framework handled billions of modelled aphids of four species in a single 30-year simulation running simultaneously with the ladybird agents. Visualisations of the simulation show aphids concentrated in natural habitat areas at first, then migrating into crop areas through long-distance dispersal as crops grow, with ladybirds tracking the aphid abundance and reproducing in response. The heatmap time series reveals the spatial and temporal complexity that emerges when a numerical prey base interacts with individual predators across a dynamic landscape.

The framework is provided as a set of C++ classes that can be integrated directly into the ALMaSS software environment or adapted to other simulation systems capable of supplying the necessary landscape data. Its conceptual structure is straightforward, but its implementation requires a solid understanding of the ALMaSS programming environment, a trade-off between complexity and flexibility that the developers argue is worth making. Because the stage-structured table and vital rate parameters can be tuned to represent a wide range of species, from aphids that give birth to live nymphs to species with entirely different life cycles, the model offers a versatile foundation for future ecological modelling. For researchers studying pest outbreaks, predator-prey dynamics, or the knock-on effects of insecticide treatments, the ability to simulate billions of individuals within a realistic landscape, without sacrificing the detail that makes agent-based modelling valuable, opens a door that has been closed for years.

Subject of Research: A general subpopulation model for the Animal Landscape and Man Simulation System ( ALMaSS )

Article Title: A general subpopulation model for the Animal Landscape and Man Simulation System ( ALMaSS )

Article References: Duan, X., & Topping, C. J. (2024). A general subpopulation model for the Animal Landscape and Man Simulation System (ALMaSS). Food and Ecological Systems Modelling Journal, 5, Article e122467. https://doi.org/10.3897/fmj.5.122467

Image Credits: AI Generated

DOI: 10.3897/fmj.5.122467

Keywords: general, subpopulation, model, Animal, Landscape, Simulation, System, ALMaSS, scientific research

Xylella fastidiosa is a xylem-limited bacterium transmitted by sap-feeding insects such as Philaenus spumarius and Neophilaenus campestris. Once inside a host, it multiplies within the water-conducting vessels, physically occluding them and triggering hydraulic failure that manifests as leaf scorch, defoliation and progressive branch death. Since its first European detection in Apulian olive trees in 2013, the pathogen has spread across France, Portugal and Spain, where the Alicante demarcated area has become a stronghold of the X. fastidiosa subspecies multiplex sequence type ST6, the strain behind almond leaf scorch disease. Its extraordinary host range, encompassing hundreds of plant species, combined with its dependence on generalist insect vectors, makes it a paradigm of a polyphagous invader capable of exploiting both cultivated and natural ecosystems.

To understand what drives the impact of this invader, a research team surveyed 19 almond orchards embedded within a semi-arid Mediterranean mosaic of limestone hills, pine forests and cultivated land. The region receives a meagre 290 to 460 millimetres of annual precipitation under a mean temperature of roughly 18 degrees Celsius, conditions that already push vegetation to its physiological limits. Within each orchard, six almond trees were visually assessed for canopy defoliation and the proportion of dead branches on a continuous 0 to 100 percent scale, following protocols adapted from the International Co-operative Programme on Forests. Adjacent natural vegetation was surveyed along parallel 50-metre transects starting at the orchard edge, where every woody and herbaceous individual was recorded, its distance from the crop measured and its health evaluated through leaf discoloration and dead branch percentages.

Molecular diagnostics formed the backbone of the study. Plant material from almond trees and selected wild species was collected according to European and Mediterranean Plant Protection Organisation standard PM7/24, which prescribes sampling xylem-rich tissues to maximise detection probability. DNA was extracted using the CTAB method and screened with a duplex quantitative PCR protocol that simultaneously targets two independent genomic regions of the bacterium, combining the Harper and Ouyang assays. A sample was deemed positive only when both protocols amplified, with cycle quantification values at or below 35 considered positive, above 38 negative and intermediate values re-tested as inconclusive. The results confirmed the presence of X. fastidiosa in 36 of 114 sampled almond trees, allowing the team to classify 11 orchards as infected and 8 as uninfected at the time of sampling. Notably, two orchards with a clean surveillance history tested positive during the survey, while two previously classified as infected showed no detection, underscoring the temporal variability of bacterial loads and the insufficiency of visual symptoms alone for reliable inference of infection status.

The phytosanitary contrast between infected and uninfected trees was stark. Mean defoliation reached 53.9 percent in infected trees against 30.2 percent in uninfected ones, while dead branch proportions climbed to 37.0 percent versus 25.6 percent, differences that were statistically significant. In the adjacent vegetation, 353 individuals belonging to 22 species were sampled, of which 40, or 11.4 percent, tested positive for the pathogen. The highest incidence occurred in Ulex parviflorus at 37.5 percent, followed by Rhamnus alaternus, Cistus albidus and Salvia rosmarinus. Crucially, 87.5 percent of all positive wild-plant samples came from areas surrounding infected orchards, and the cycle quantification values in those plants were markedly lower, ranging from 16.3 to 38.0, indicating far higher bacterial concentrations than in vegetation near uninfected orchards, where values clustered between 32.7 and 36.3. Lower quantification cycles translate into greater inoculum availability, which in turn raises the probability that xylem-feeding vectors acquire the bacterium while feeding.

The statistical analysis employed generalised linear mixed models within a multi-model inference framework, screening predictors for collinearity, standardising them and selecting models through an all-subsets approach based on the corrected Akaike Information Criterion. Akaike weights ranked predictor importance and coefficients were estimated as weighted averages across models within four criterion units of the best fit. The models revealed that defoliation in almond trees increased significantly with X. fastidiosa infection, higher shrub cover within the orchard, greater abundance of potential host species in the adjacent vegetation and higher long-term variability in potential evapotranspiration, a proxy for drought-related climatic stress. Defoliation decreased with increasing landscape contagion, meaning that more fragmented landscapes, where the contagion index is lower, suffered greater damage. Dead branch percentages rose with infection and shrub cover but fell with higher annual mean potential evapotranspiration. Significant interactions between infection and several environmental variables, including evapotranspiration range, shrub cover, host abundance and the Compound Topographic Index, a measure of soil water retention, all pointed in the same direction: infected orchards exhibited exacerbated symptoms under elevated drought variability, denser shrub cover, higher host abundance and lower soil water availability.

Perhaps the most provocative result concerns plant diversity. Contrary to the dilution hypothesis, which posits that richer communities reduce pathogen transmission, overall Shannon diversity of the adjacent vegetation showed no buffering effect on almond health. Instead, the abundance of potential X. fastidiosa host plants in the surrounding wild vegetation was positively associated with defoliation in infected orchards, suggesting an indirect facilitation of disease dynamics. For a generalist pathogen with such a broad host range, a denser assemblage of competent hosts likely increases landscape-level inoculum and provides continuous habitat for insect vectors, amplifying pressure on the focal crop. Interestingly, the direct detection of the bacterium in adjacent vegetation was not linked to almond damage, implying that the role of wild hosts as vector reservoirs may matter more than their role as direct pathogen reservoirs in this system. The authors propose that vector persistence, rather than pathogen spillover per se, could be the critical mechanism linking wild host abundance to crop decline, although transmission processes were not directly assessed.

In the natural vegetation itself, the story was different. Leaf discoloration and branch dieback in wild plants were governed primarily by abiotic stress gradients rather than by pathogen presence. Discoloration increased with higher plant diversity, greater distance from orchard edges, higher host species abundance, higher temperatures and lower precipitation, while dead branch rates rose with distance from the crop. The positive effect of distance may reflect denser, less-managed semi-natural communities where competition for scarce water intensifies under Mediterranean conditions. Higher diversity itself may amplify competition during drought, increasing susceptibility to abiotic stress rather than to infection. This contrast between managed and natural systems underscores a differential vulnerability: almond orchards suffer most where infection synergises with drought and landscape fragmentation, whereas wild communities decline mainly under climatic pressure.

The management implications are far-reaching. The authors advocate a shift from reactive eradication towards integrated, landscape-level strategies that explicitly incorporate landscape configuration, vegetation structure and climate context into phytosanitary decision-making. Surveillance should prioritise orchards embedded in drought-prone, fragmented landscapes with high shrub cover and abundant alternative hosts. Strategic management of key reservoir species such as Ulex parviflorus and Cistus spp., together with the reduction of dense shrub cover within and immediately adjacent to orchards, may limit vector habitat suitability without compromising broader biodiversity values. Drought adaptation, through optimised irrigation, soil management that improves water retention and drought-resilient rootstocks, should be regarded as a central pillar of pathogen management under climate change, potentially weakening the interaction between abiotic stress and invasion impact. Above all, the findings caution against promoting plant diversity per se as a disease buffer when the invader is a polyphagous generalist; host identity and density, not diversity metrics alone, are the variables most directly tied to invasion dynamics and vector ecology.

The study is not without limitations. Its single-season design cannot capture the seasonal and inter-annual fluctuations of bacterial titres, and the visual symptoms recorded can also be induced by other undiagnosed biotic or abiotic stressors. Transect-based measures of host abundance serve as proxies for reservoir size, and future work integrating vector population densities, movement patterns and transmission assays will be needed to forge the causal links suggested here. Nevertheless, by combining field surveys, molecular diagnostics and landscape analysis within a coherent invasion-biology framework, the research delivers a robust foundation for risk assessment in Mediterranean agroecosystems and offers a template for confronting other invasive, polyphagous pathogens in an era of accelerating global change.

Subject of Research: Landscape and environmental drivers of plant health decline during an active invasion of Xylella fastidiosa Wells et al. in Mediterranean agroecosystems

Article Title: Landscape and environmental drivers of plant health decline during an active invasion of Xylella fastidiosa Wells et al. in Mediterranean agroecosystems

Article References: Hernández-Lambraño, R. E., Ruiz-Gómez, F. J., Vilà, M., Landa, B. B., Hernández-Clemente, R., Fernández-Bravo, M., Quesada-Moraga, E., Olivares-Garcia, C., & González-Moreno, P. (2026). Landscape and environmental drivers of plant health decline during an active invasion of Xylella fastidiosa Wells et al. in Mediterranean agroecosystems. NeoBiota, 109, 25-43. https://doi.org/10.3897/neobiota.109.190448

Image Credits: AI Generated

DOI: 10.3897/neobiota.109.190448

Keywords: Xylella fastidiosa, plant pathology, invasive species, almond orchards, Mediterranean ecosystems, drought stress, landscape ecology, NeoBiota, Landscape, environmental, drivers, plant

The research, led by Bharat Bhushan and colleagues at Lovely Professional University with collaborators from Manipal University Jaipur, the University of Pécs in Hungary and Minia University in Egypt, set out to answer a question that conventional urban studies often gloss over. Most assessments of Indian cities rely on simple area statistics or single-date land-use comparisons, which can quantify the magnitude of growth but say little about its mode. The team instead applied the Landscape Expansion Index, or LEI, a metric that classifies every newly grown urban patch as infilling, edge-expansion or leapfrog development depending on its spatial relationship to pre-existing built-up land. Patches with LEI values above 50 are classified as infilling, those between 0 and 50 as edge-expansion, and those at exactly zero as leapfrog, meaning entirely disconnected new development.

To build the analysis, the researchers drew on multi-temporal Landsat 5 Thematic Mapper and Landsat 8 OLI/TIRS surface reflectance imagery for five observation years: 2000, 2005, 2010, 2015 and 2020, all acquired during the post-monsoon months of October and November to minimize atmospheric and phenological variation. The images were classified in QGIS using a supervised Minimum Distance classifier trained on 50 to 100 pixels per land-cover class, with training samples compiled from high-resolution Google Earth imagery and field observations. Accuracy assessment using 200 stratified random sample points produced overall accuracies ranging from 85.63 percent in 2000 to 92.38 percent in 2020, with kappa coefficients climbing steadily from 0.85 to 0.92, a gradual improvement the authors attribute to better sensor radiometric resolution and spectral range over the two decades.

The classified built-up layers were then interrogated through concentric distance buffers at 2, 4, 6, 8 and 10 kilometers from the city center and through eight directional wedges radiating outward. The results revealed a striking anisotropy in Rohtak’s growth. The north-western and western sectors emerged as the most aggressive fronts of expansion, with built-up area at 6 kilometers northwest increasing by 69.6 percent, from 3.03 to 5.14 square kilometers, between 2000 and 2020. At 4 kilometers north, urban area surged by an extraordinary 410 percent, from 0.65 to 3.32 square kilometers. The largest single regional increase was recorded at 8 kilometers southwest, where built-up area grew by 365 percent over the study period. By contrast, the eastern corridor remained conspicuously underdeveloped, with growth at 2 kilometers east amounting to just 1.3 percent.

The Mann-Kendall trend test combined with Sen’s slope estimator confirmed that this directional selectivity is statistically robust rather than a product of noise. At the innermost 2-kilometer radius, significant increasing trends appeared in the northeast, north, northwest, southwest, south and southeast sectors, with the steepest rates northward at 0.034 square kilometers per year, while the pure east and west sectors failed to reach significance. From 4 kilometers outward, every sector exhibited a statistically significant increasing trend, with the highest single slope recorded in the northern sector at 4 kilometers, at 0.127 square kilometers per year, followed by the eastern sector at 6 kilometers at 0.135 square kilometers per year. Beyond 6 kilometers the rates moderated but remained positive and significant, indicating that expansion continues into the outer annuli at a slower absolute pace.

The distance-gradient analysis produced one of the study’s most consequential findings: a clear concentric structure in the mode of expansion. At 2 kilometers from the core, growth was classified almost entirely as infilling, with LEI values ranging from 46.17 to 99.80, and edge-expansion dropping to zero after 2005, confirming that the saturated core is filling in its last vacant gaps rather than adding new territory. At 4 kilometers the picture was transitional, with infilling predominating in the northwest and west while edge-expansion dominated elsewhere. Beyond 4 kilometers, infilling disappeared completely; all expansion at 6, 8 and 10 kilometers was edge-expansion, with the 6-kilometer ring consistently contributing the largest single share of total growth, between 23.74 and 25.29 percent. The authors interpret this as evidence that infill saturation occurs between 2 and 4 kilometers of the core, while leapfrog and edge-expansion processes dominate between 6 and 10 kilometers, especially around the larger institutions and the Industrial Model Township developed by HSIIDC along National Highway 9.

Complementary landscape metrics corroborated this reading. Edge length rose steadily in seven of the eight sectors, with the largest absolute gains in the northern and eastern corridors, while the Largest Patch Index increased or remained near saturation above 90 percent in the northern, northeastern, eastern and southeastern sectors, indicating progressive dominance by a single contiguous urban core. Mean patch area accelerated sharply after 2010, most markedly in the southeastern and eastern sectors, consistent with the coalescence of previously discrete patches. In parallel, edge density and patch density declined across all directions, the steepest reductions occurring in the southern sector, and the number of patches fell correspondingly, with the most rapid loss in the southeast, from 40 to 14. Landscape division and splitting indices decreased monotonically, falling below 0.2 and 1.5 respectively in most sectors by 2020, signalling a measurable reduction in fragmentation and a corresponding rise in the contiguity of the built-up fabric.

To move beyond configuration and capture the temporal ordering of change, the team applied Principal Component Analysis to the multicollinear set of landscape metrics, standardized across distance and directional strata. Two retained components explained 86.01 percent of the variance in the direction-wise analysis and 92.35 percent in the distance-wise analysis, with Kaiser-Meyer-Olkin values of 0.656 and 0.732 respectively confirming sampling adequacy. Projecting successive yearly observations onto the two-dimensional component space yielded trajectory metrics: total path length, net displacement, straightness and step lengths between consecutive intervals. The largest cumulative multivariate shifts occurred at 2 kilometers, with a total length of 2.26, and at 8 kilometers, with 2.13, reflecting terminal infilling of the core and active fringe coalescence respectively, while the 4 and 6 kilometer rings showed comparatively short paths indicative of a more stable, mid-transition configuration. All trajectories were strongly directional, with straightness indices ranging from 0.74 to 0.99, demonstrating that change was dominated by a consistent driver rather than random fluctuation.

Direction-wise trajectories sharpened the picture further. The northern, eastern and southeastern sectors traced the longest, most displaced paths in component space, with total lengths between 3.30 and 4.10, indicating the most complete transition from fragmented to coalesced form, while the western, southwestern and northwestern sectors followed short, tortuous, low-straightness paths, signalling that their considerable built-up gains were achieved largely through in-place densification and infilling rather than radial advance. Notably, the single largest multivariate jump clustered in the 2010 to 2015 window, coinciding with Rohtak’s elevation to Municipal Corporation status in 2010 and the attendant 240 percent enlargement of its municipal boundary. The authors suggest that this discrete administrative shock may be temporally associated with an accelerated transition from diffusion toward greater morphological contiguity, though they caution that the observational design cannot establish causation.

Read through the diffusion-coalescence framework of urban growth, the findings resolve Rohtak’s two decades into three phases: a fragmented phase from 2000 to 2010, when numerous small patches emerged through opportunistic development as surrounding villages were gradually engulfed; a transitional phase from 2010 to 2015, when patches began to merge as mean patch area and the Largest Patch Index rose and fragmentation indices fell; and a coalescence phase from 2015 to 2020, when contiguous large patches dominated and edge and patch densities fell, producing a classic consolidation pattern guided by National Highway 9 integration and the Rohtak Master Plan 2031. The directional bias itself, the authors argue, is endogenously generated rather than imposed by geography, since the city sits on unconstrained flat terrain. Instead, the growth engines are identifiable anchors: Maharshi Dayananda University, the Indian Institute of Management Rohtak and the Pt. B.D. Sharma University of Health Sciences, which generate sustained demand for housing and services, reinforced by the Industrial Model Township and radial highway connectivity to Delhi. The muted eastern corridor, lacking equivalent pull-factors and possibly zoned for agriculture or future-use reserves, is earmarked by a proposed eastern industrial township for later-phase growth. Overall, Rohtak exemplifies a ripple-effect urbanisation model, shifting from a monocentric core to polycentric, corridor-based growth at the edges, and the integrated distance-direction-trajectory framework the researchers developed, requiring only multi-date classified built-up layers and a defined urban core, is readily transferable to the secondary cities of South and Southeast Asia, Sub-Saharan Africa and Latin America, where an estimated 90 percent of future urban growth will occur and where planning still relies heavily on aggregate-area assessments.

Subject of Research: Assessing urban development trajectories using landscape expansion metrics and multivariate statistical approaches: evidences from rohtak city, NCR, India

Article Title: Assessing urban development trajectories using landscape expansion metrics and multivariate statistical approaches: evidences from rohtak city, NCR, India

Article References: Bhushan, B., Singh, S., Mandal, S., Sharma, V., Kumar, P., Fülöp, A., & Elhdad, S. (2026). Assessing urban development trajectories using landscape expansion metrics and multivariate statistical approaches: evidences from rohtak city, NCR, India. Frontiers in Remote Sensing, 7, Article 1912607. https://doi.org/10.3389/frsen.2026.1912607

Image Credits: AI Generated

DOI: 10.3389/frsen.2026.1912607

Keywords: Assessing, urban, development, trajectories, landscape, expansion, metrics, multivariate, statistical, approaches, evidences, rohtak

The research, published in Frontiers in Health Services by a team at Xuzhou Medical University led by Zhiqiang Hao, Guoxuan Xu, Wei Zhuang, Xingchen Zhu, and Xianliang Yan, is the first of its kind in this domain. It integrates three methods: a bibliometric mapping of 683 publications from 2015 to 2026, a PRISMA-ScR-compliant scoping review of 168 studies following Joanna Briggs Institute methodology with the PAGER (Patterns, Advances, Gaps, Evidence, Recommendations) synthesis framework, and a quantitative policy text analysis of 62 Chinese policy documents related to the low-altitude economy and emergency medical rescue from 2020 to 2025, yielding 526 codable policy provisions. The design is deliberately sequential: the bibliometric clusters supply the organizing domains for the scoping review, the barriers charted in the review structure the value-chain dimension of the policy coding, and the resulting policy-gap diagnosis is read against the maturity of the clinical evidence.

The bibliometric analysis identified 683 unique publications across five thematic clusters, with exponential growth from 2022 onward. The largest and most densely interconnected cluster centers on drone-delivered automated external defibrillators (AEDs) for out-of-hospital cardiac arrest, followed by medical supply logistics, eVTOL and advanced air mobility, helicopter EMS as comparator context, and health system and policy integration. Notably, the linkage strength between the eVTOL technology cluster and the health policy cluster was only 0.12, compared to 0.67 between the drone AED and logistics clusters — a quantitative confirmation that the communities building the aircraft and the communities studying health governance barely talk to each other. Only nine publications across all databases searched addressed eVTOL aircraft specifically in medical or health contexts, confirming how nascent this subfield remains.

The scoping review synthesized evidence showing drone-delivered AEDs arrived before ambulances in 67% of cases, with a median lead time of 3 minutes and 14 seconds. In Sweden, Schierbeck and colleagues demonstrated this prospectively in the Gothenburg region, and a subsequent analysis showed that a structured dispatcher educational bundle could raise bystander AED attachment from 27% to 50%. Denmark replicated the findings with semi-autonomous drone operations in Aalborg, achieving a 100% delivery success rate across 16 eligible cases, though the median drone response of 4 minutes 47 seconds was slightly slower than the corresponding ambulance response of 3 minutes 25 seconds in that dense urban context — a reminder that drone effectiveness depends critically on base station placement relative to existing EMS infrastructure.

The economic evidence is particularly striking. Building on the network-optimization lineage inaugurated by Boutilier and colleagues in Toronto, Maaz and colleagues constructed a Markov microsimulation using data from 22,017 out-of-hospital cardiac arrests over a decade in Ontario, evaluating 964 distinct drone network configurations. Every configuration proved cost-effective under the model’s assumptions, with the smallest non-dominated network of 20 drones generating an incremental cost-effectiveness ratio of $20,912 per quality-adjusted life year gained. Drone networks reduced response times by 32% to 71% compared to standard care and improved hospital discharge survival by 21% to 46%. In the logistics domain, Rwanda’s Zipline program, analyzed by Nisingizwe and colleagues across 12,733 deliveries, documented a 61% reduction in blood product delivery time and a 67% decrease in blood unit expiration rates; the program has since expanded to six countries with over two million deliveries.

At the eVTOL scale, evidence remains predominantly simulation-based. Heidet and colleagues modeled 6,217 real cardiac arrest cases across Greater Paris and Metro Vancouver, finding that deploying one to two VTOL ambulances cut advanced life support arrival times from 21 minutes to 7–9 minutes in Paris and from 12 to 7–9 minutes in Vancouver. Goyal and Cohen identified battery technology as the primary constraint: current charge times would need a four-fold reduction before eVTOLs could compete operationally with ground ambulances for short-distance transports under 40 kilometers. Industry partnerships are advancing rapidly, with ADAC Luftrettung and Volocopter planning 250 multicopter stations across Germany, and several Chinese manufacturers developing medical-specific platforms at estimated operating costs one-third to one-half those of conventional helicopters.

A sobering contextual finding comes from the traditional helicopter EMS literature. The largest meta-analysis to date, by Orso and colleagues, pooling 77 studies involving 2.6 million patients, could not conclusively demonstrate survival benefits over ground EMS, with a mortality risk ratio of 1.13 (95% CI: 0.96–1.34) based on very low quality evidence. Subgroup analysis restricted to patients with an Injury Severity Score of at least nine did find a survival benefit for helicopter scene response, suggesting aerial platforms may generate value in well-selected populations even where all-comer analyses are null. This uncertain cost-effectiveness of traditional HEMS creates a powerful argument for novel eVTOL platforms that could deliver comparable clinical capabilities at substantially lower per-mission costs — but it also cautions against assuming that faster response times automatically translate into better outcomes.

The policy analysis of 526 coded provisions across 62 Chinese documents revealed a pronounced structural imbalance. Environmental tools constituted 38.4% of provisions, supply-side tools 36.9%, while demand-side tools accounted for only 24.7%. Governments have been effective at funding research, building vertiport networks, and establishing airspace management reform, but have devoted insufficient attention to procurement mechanisms, insurance pathways, and market signals that would incentivize sustained operational deployment. The Policy Modeling Consistency (PMC) Index, applied to evaluate the comprehensiveness and internal consistency of individual documents, yielded a mean score of 7.46 (SD = 0.89), classified as “Good” on the Estrada scale, with timeliness (0.73) and policy measures (0.72) as the weakest dimensions. Talent cultivation received the lowest policy attention on the emergency rescue value chain, with only 12.4% of coding units — a critical gap for training hybrid aviation-medical professionals, a workforce category that does not yet exist in any country’s occupational classification system.

Synthesizing these findings, the authors propose a “dual-wheel drive, four-chain integration” framework. The scenario implementation wheel addresses whether aerial emergency medical services can work in specific operational contexts — drone AED delivery for cardiac arrest in areas with response times exceeding 8–10 minutes, blood product delivery to facilities more than 30 minutes from blood banks, and eVTOL patient transport for time-sensitive conditions across 40–150 kilometers. The ecosystem cultivation wheel addresses whether such services can be sustained, scaled, and equitably distributed, encompassing four interdependent chains: infrastructure, industrial innovation, institutional policy, and human capital. The framework’s central argument is that the failure mode for eVTOL emergency medical services is unlikely to be technological but rather ecosystemic — a successful demonstration flight proves only that one link in a complex chain can function under controlled conditions.

The study has limitations the authors acknowledge candidly: no formal risk-of-bias appraisal was undertaken, the review was not prospectively registered, the policy corpus was limited to Chinese national and provincial documents, and the published record should be read as a conservative lower bound on field activity in an operator-led domain where evidence generation lags practice by years. Still, the evidence base for drone-delivered AEDs and drone-based medical logistics has reached a level that supports active integration into health service delivery models, provided deployment is coupled to prospective outcome evaluation. As nations worldwide accelerate investment in advanced air mobility — China elevated the low-altitude economy to an “emerging pillar industry” in its 2026 Government Work Report, and twenty-nine provinces had incorporated it into planning by mid-2025 — the health services research community faces both an opportunity and a responsibility to ensure that the integration of these technologies into emergency care is guided by evidence, equity, and the imperative to save lives otherwise lost to the tyranny of distance and time.

Subject of Research: Drones and eVTOL aircraft could transform emergency medical services, but a new triple-method analysis shows policy frameworks lag behind the technology.

Article Title: Mapping the research landscape of UAV- and eVTOL-enabled emergency medical services: a bibliometric analysis, scoping review, and policy tool assessment

Article References: Hao, Z., Xu, G., Zhuang, W., Xu, L., Xu, T., Zhu, X., & Yan, X. (2026). Mapping the research landscape of UAV- and eVTOL-enabled emergency medical services: a bibliometric analysis, scoping review, and policy tool assessment. Frontiers in Health Services, 6, Article 1861375. https://doi.org/10.3389/frhs.2026.1861375

Image Credits: AI Generated

DOI: 10.3389/frhs.2026.1861375

Keywords: emergency medical services, UAV, eVTOL, drones, health policy, cardiac arrest, scoping review, bibliometrics, Mapping, research, landscape, UAV-

The methodological design of the study is itself notable for its rigor in a field where such designs are often missing. The researchers used a sequential mixed-methods approach, labeled QUAN-qual, meaning the quantitative phase came first and directly informed the qualitative phase that followed. In the quantitative phase, the team surveyed 71 faculty members who held postgraduate training in medical education, drawn from institutions across Pakistan, and achieved a striking 93.4 percent response rate. Such a high rate matters because it reduces the risk that the survey reflects only the views of the most motivated or most frustrated respondents. The qualitative phase then used two focus group discussions, one with junior faculty and one with senior faculty, to dig beneath the survey numbers and understand the lived experience behind them.

The results reveal a generational split in the obstacles that matter most. Among junior faculty, the primary challenges in conducting medical education research were lack of time, lack of training, and lack of support. These are, in many respects, the classic barriers reported by early-career researchers everywhere, but in Pakistan they take on a particular intensity because medical educationists often carry heavy teaching and administrative loads with no protected time carved out for scholarship. For senior faculty, the picture shifted: their main challenges were lack of funding for publication, the absence of well-reputed local journals devoted to medical education research, and a pervasive culture of mistrust that undermines collaboration. In other words, even those who had survived the early career bottleneck found themselves facing a publishing ecosystem and a professional culture that offered little reward or scaffolding.

The qualitative analysis distilled these findings into overarching themes that applied to both junior and senior faculty. At the systemic level, participants described the absence of protected time and inadequate institutional support as structural features of their working lives, not temporary inconveniences. At the individual level, they acknowledged gaps in their own preparation, including insufficient training in research methods and in the theoretical frameworks that give educational scholarship its analytical backbone. This dual diagnosis is important because it suggests the problem cannot be fixed by training alone or by institutional reform alone; the barriers operate at multiple levels simultaneously and reinforce one another. A well-trained educationist with no protected time produces nothing, while an educationist with generous time but no methodological grounding produces work that journals will not accept.

The context in which these findings sit is a global one. Medical education research is overwhelmingly produced in high-income countries, with limited contribution from low- and middle-income countries such as Pakistan. This asymmetry matters for science as a whole because educational questions in Lahore or Karachi differ in funding realities, class sizes, student demographics, and cultural expectations from those in Boston or London. When the evidence base for how to teach medicine is built almost entirely in resource-rich settings, its findings travel poorly to the places where most of the world’s medical students actually study. Pakistan, as the study’s authors note, has made departments of medical education mandatory in every medical and dental college, creating a large pool of trained professionals whose insights are, in principle, exactly what the global literature lacks.

The study was conducted with formal ethical oversight, receiving approval from the Ethics Review Committee at Aga Khan University Hospital under study ID 2022-7738-23209, with informed consent obtained from all participants and the research conducted in accordance with the ethical principles of the Declaration of Helsinki. The researchers report that the work received no specific grant from any funding agency in the public, commercial, or non-profit sectors, a detail that is perhaps telling in itself: even a study about the lack of research funding had to proceed without it. The authors declare no competing interests, and the article is published open access under a Creative Commons license, making the full findings freely available to the very community of educationists whose circumstances it documents.

What makes the study’s conclusions actionable is the specificity of its recommendations. The authors argue that scholarship in medical education in Pakistan is hindered by individual, institutional, and systemic factors, and they direct their prescriptions accordingly. Institutions, they conclude, need to focus on providing protected research time, bolstering training in medical education research, and establishing robust mentorship and collaborative networks to strengthen the research culture. Protected time, in particular, is a recurring theme in faculty development research worldwide, but the Pakistani data give it local weight: when 93 percent of trained educationists in a national survey point to time as a barrier, the case for institutional scheduling reforms becomes difficult to ignore.

The mistrust that senior faculty identified as a barrier to collaboration deserves particular attention, because it points to a problem that no amount of funding can solve on its own. Collaborative research depends on norms of credit-sharing, transparent authorship, and confidence that intellectual contributions will be respected. Where those norms are weak, researchers retreat into silos, small studies go unpublished, and the cumulative building of knowledge stalls. Similarly, the absence of well-reputed local journals means Pakistani educationists face a choice between competing in high-income-country journals with rejection rates shaped by different priorities, or publishing in venues with limited visibility. A credible regional publication infrastructure, the findings imply, is not a vanity project but a structural prerequisite for a self-sustaining research community.

The implications extend well beyond Pakistan’s borders. The World Health Organization and international medical education bodies have repeatedly emphasized that health workforce education in low- and middle-income countries must be evidence-driven rather than imported wholesale from contexts that differ fundamentally. Studies like this one provide the diagnostic foundation for that ambition, identifying exactly where the pipeline from trained educationist to published researcher breaks down. The senior authors, including Naveed Yousuf, and co-author Syed Moin Ali of Aga Khan University’s Department for Educational Development, along with Rafay Iqbal of the university’s Department of Family Medicine, frame their work as a mapping exercise, and the map they produce is one that institutional leaders, policymakers, and international funders can all read. For junior faculty wondering whether their struggles are personal failings, and for deans wondering why their education departments generate so little publishable output, the answer documented here is neither indolence nor incapacity, but the accumulated weight of missing time, missing training, missing money, missing journals, and missing trust.

Beyond its specific findings, the study offers a useful illustration of how research capacity itself can be built in resource-constrained settings. The near-complete survey response suggests that Pakistani medical educationists were eager to have their professional difficulties documented, an appetite for engagement that institutions could harness. The sequential design also demonstrates a pragmatic model for LMIC researchers: a modest survey followed by focused group discussions can generate publishable, policy-relevant evidence without the large budgets that often deter early-career scholars in such settings.

The timing of the work is also worth noting. The article was released as an accepted manuscript ahead of its final version of record, a publishing route that shortens the lag between peer review and public availability. For a field whose participants explicitly identified slow, difficult publication as a barrier, faster dissemination models have practical relevance. The open access license further means the findings can circulate freely among the very institutions expected to act on them, including smaller colleges that may lack journal subscriptions.

There is also a measurement lesson embedded in the study. By separating junior and senior faculty experiences, the researchers avoided treating the workforce as a monolith, revealing that career stage changes which barriers dominate. That distinction has direct implications for intervention design: mentorship schemes and protected time may matter most early on, while funding access, journal infrastructure, and trust-building become decisive later. Capacity-building programs imported from high-income countries frequently assume a uniform faculty trajectory, and this evidence argues for tailoring support to career stage. The study thus functions both as a diagnosis of Pakistan’s medical education scholarship landscape and as a template for how other low- and middle-income countries might map their own.

Subject of Research: Mapping the landscape: current status, challenges, and perspectives on scholarship of medical educationists in Pakistan

Article Title: Mapping the landscape: current status, challenges, and perspectives on scholarship of medical educationists in Pakistan

Article References: Sabzwari, S. R., Ali, S. M., Iqbal, R., & Yousuf, N. (2026). Mapping the landscape: current status, challenges, and perspectives on scholarship of medical educationists in Pakistan. BMC Medical Education. https://doi.org/10.1186/s12909-026-10078-0

Image Credits: AI Generated

DOI: 10.1186/s12909-026-10078-0

Keywords: Mapping, landscape, current, status, challenges, perspectives, scholarship, medical, educationists, Pakistan, scientific research