The team’s fieldwork covered 16 plots across four land-use systems, each plot a 500-square-meter sampling unit designed to capture the internal variability of these ecosystems. In the coffee systems, located between 1,060 and 1,080 meters above sea level, the researchers measured every tree within their plots, recording trunk diameter at breast height, total height, and wood density. These measurements fed into generalized allometric regression equations that estimate aboveground biomass from trunk dimensions and wood basal density, with species-level wood density values drawn from the Global Wood Density Database. Where species data were unavailable, the team used genus or family averages. Belowground biomass was estimated using root-to-shoot ratios developed for tropical highland forests, and a standard carbon fraction of 50 percent was applied to convert dry biomass into carbon, a figure consistent with IPCC default values of 0.47 to 0.50 for tropical woods.

The results are unambiguous. Primary forests stored approximately 133.74 tonnes of aboveground carbon per hectare and 40.12 tonnes of belowground carbon per hectare, equivalent to roughly 638.05 tonnes of carbon dioxide per hectare when the carbon is converted to its CO2 equivalent. The coffee systems, by comparison, stored dramatically less. Among them, the agroforestry coffee system with mixed shade trees performed best, followed by coffee grown with Inga, while the monoculture system consistently registered the lowest values across every carbon metric. The statistical models, fitted with Gamma distributions and generalized linear mixed models in R, achieved adjusted R-squared values exceeding 99 percent, confirming that the differences in carbon storage were overwhelmingly associated with the type of ecosystem rather than random variation.

Biodiversity followed the same gradient. Using the Shannon index, Simpson index, and Pielou evenness index, the researchers found that primary forests hosted the highest species richness and the most balanced distribution of individuals across all metrics, with statistically significant differences at p < 0.01. The agroforestry coffee system maintained a species richness of 6.25, though its lower evenness value of 0.42 suggested that a few dominant species shaped the community. Coffee grown with Inga showed lower richness at 2.0 but moderate evenness at 0.58, while the monoculture system presented minimal diversity, reflecting a simplified community dominated by very few species. The primary forest’s superior diversity may be linked to its higher elevation of 1,625 meters, where cooler temperatures and greater humidity favor the coexistence of more plant species.

When the researchers translated carbon storage into economic terms using Peru’s social cost of carbon of 7.1 US dollars per tonne, the primary forest’s value reached approximately 949.52 dollars per hectare in aboveground carbon alone, with additional valuations of 284.86 dollars per hectare in belowground carbon and 4,530.15 dollars per hectare when total CO2 storage was considered. The coffee systems, by contrast, registered values far below these figures, with the agroforestry system performing best among them and the monoculture worst. The economic gap between primary forest and any coffee system is so wide that the researchers describe forest conversion as generating significant losses in carbon-related benefits, losses that compound with every additional hectare cleared.

A sensitivity analysis tested how these valuations would shift under alternative carbon pricing scenarios. At low prices of 5 and 20 dollars per tonne of CO2, the economic differences between coffee systems narrowed considerably. But from 50 dollars per tonne upward, the gap widened, with the agroforestry coffee system standing out as the highest-value option among the coffee treatments, followed by coffee with Inga and then the monoculture. At 100 dollars per tonne, the greater structural complexity of the agroforestry system translated into a clearly visible relative economic advantage, suggesting that carbon markets could increasingly reward farmers who maintain shade trees and diverse canopy structures within their coffee plantations.

A principal component analysis integrating the ecological and economic data revealed that the first two axes explained 94.07 percent of total variation, with the first component capturing a robust gradient from simplified monoculture systems to complex, carbon-rich primary forests. The biplot positioned primary forests at the high end of total CO2, evenness, Shannon diversity, and Simpson index values, while the agroforestry coffee system clustered near species richness, and the monoculture sat at the opposite end of the gradient. Coffee with Inga occupied an intermediate position, suggesting a transitional state between low and high ecological complexity. This multivariate structure reinforces the biodiversity-functioning theory: ecosystems with greater species diversity tend to store more carbon because diverse communities use resources more complementarily, build more complex forest structures, and are more resilient to environmental disturbances.

The findings carry direct implications for climate policy in Peru and beyond. The researchers note that forests are expected to contribute roughly 10 percent of the mitigation required to limit global warming to 1.5 degrees Celsius, which would require carbon prices to reach approximately 281 dollars per tonne of CO2 by 2055. By comparison, the average carbon sequestration cost in northwest China has been estimated at 4.77 dollars per tonne, well below the 7.1 dollars per tonne applied in this study. Protecting forests in the Peruvian Amazon may require investments ranging from 7.97 to 10.45 dollars per tonne of CO2, figures that support the implementation of conservation strategies and increase the economic value of standing forests. The study’s authors argue that these valuations provide a technical basis for incorporating coffee agroforestry systems into Payments for Ecosystem Services schemes and for aligning coffee production models with Peru’s Nationally Determined Contributions under international climate agreements.

The research also speaks to the principles of REDD+ initiatives, which aim to conserve forests and increase carbon stocks through economic incentives. The observed transition from monoculture coffee to agroforestry systems represents a trajectory compatible with REDD+ objectives by simultaneously increasing stored carbon and biological diversity. The economic potential associated with conserving tree cover, rising from 174.06 dollars per hectare in monoculture to 4,530.15 dollars per hectare in primary forest, illustrates how market mechanisms such as PES and REDD+ can generate effective incentives when supported by strong institutions, transparent monitoring systems, and equitable distribution of benefits among local actors. In Latin America, which constitutes one of the main global suppliers of forest carbon credits, agroforestry systems hold particular promise for generating credits due to their CO2 capture capacity, though certification continues to face challenges related to additionality, permanence, and transparency of projects.

The authors acknowledge that their observational comparison carries limitations. The primary forest site sat more than 500 meters higher than the coffee systems, an altitudinal difference that could influence carbon dynamics, though previous research has shown that the loss of aboveground biomass from forest conversion dominates the carbon balance at all elevational levels. The models achieved high statistical fit, but uncertainty remains associated with ecosystem variability, biomass measurement, and the selection of allometric equations, meaning small changes in carbon estimates could modify the economic valuation of the ecosystem service. Nevertheless, the study’s central message is clear: conserving native forests remains the most effective strategy for maintaining carbon storage, biodiversity, and ecosystem services in the Peruvian Amazon, while promoting sustainable agroforestry practices offers a complementary pathway that rewards farmers for keeping trees on the land. As Peru grapples with continued forest loss, these findings provide the quantitative evidence needed to make standing forests economically competitive with the coffee that threatens to replace them.

Subject of Research: Carbon sequestration economics of forest-to-coffee conversion in the Peruvian Amazon

Article Title: Converting forests to coffee cultivation (Coffea arabica) significantly reduces organic carbon sequestration payments in the Peruvian Amazon

Article References: Gaona-Jimenez, N., Padilla-Macedo, B. T., Saucedo Vega, W., Ludena-Cárdenas, J. C., Zevallos Ruiz, M., Ríos Vargas, C., Martínez Quiroz, E. N., Gutiérrez López, J. F., Saavedra-Ramírez, J., Tuesta-Hidalgo, J. C., Tuesta-Hidalgo, O. A., Hidalgo Tuesta, J. J., Rengifo Amasifen, R. R., Juárez Rivero, A. A., Aldava Pardave, U., & Ordonez-Ruiz, K. M. (2026). Converting forests to coffee cultivation (Coffea arabica) significantly reduces organic carbon sequestration payments in the Peruvian Amazon. Frontiers in Environmental Economics, 5, Article 1905945. https://doi.org/10.3389/frevc.2026.1905945

Image Credits: AI Generated

DOI: 10.3389/frevc.2026.1905945

Keywords: carbon sequestration, Peruvian Amazon, coffee agroforestry, REDD+, payments for ecosystem services, biodiversity, Converting, forests, coffee, cultivation, Coffea, arabica

The research team surveyed 155 households in Corosha, a community of roughly 250 families in the Bongará Province of Peru’s Amazonas Department, whose territory borders and partially overlaps the Hierba Buena-Allpayacu Private Conservation Area. That protected landscape, spanning montane forests, shrublands and grasslands between 2,000 and 3,000 metres above sea level, shelters species such as the Andean cock-of-the-rock, the puma, the spectacled bear and the endemic yellow-tailed woolly monkey. The survey, conducted in July 2023 with a sample calculated for finite populations at a 95 percent confidence level, achieved an unusually high coverage rate of 62 percent of all families, mitigating the selection bias that often plagues remote fieldwork. Two trained local interviewers independently coded a subset of 30 interviews, achieving an average inter-coder reliability kappa of 0.72, a solid figure for exploratory social research in challenging rural conditions.

The sociodemographic profile that emerged is telling. Respondents averaged 39.3 years of age, with households of 3.9 members on average, and women made up 86.4 percent of participants, reflecting their central role in rural Amazonian subsistence agriculture. Agriculture was the primary economic activity for 80 percent of households, and 92.9 percent of families maintained a chacra, the small agricultural plot that anchors Amazonian livelihoods. Tubers dominated the cropping system, grown by 85.4 percent of farming families, followed by sugarcane and maize at 48.6 percent each and beans at 46.5 percent. Two-thirds of farmers visited their plots daily or more often, a level of management intensity that the authors note resembles patterns seen in fruit gardens of Loreto, where frequent visits correlate with higher productivity and fewer pests.

But the chacra is not only a place of crops. In a finding the researchers describe as rarely documented in the literature, 66.7 percent of farmers reported being accompanied by animals, mainly dogs, during their visits to agricultural plots. This practice transforms the chacra into a multi-species meeting ground where domestic and wild animals routinely cross paths. Overall, roughly 80 percent of households kept animals both in their homes and on their plots, with livestock such as cattle and horses concentrated on farm plots while dogs and cats clustered around dwellings. The result is a tripartite interface among humans, livestock and wildlife that conservation biologists have increasingly recognised as a critical, and often overlooked, driver of both conflict and disease transmission.

The health data collected in Corosha underscore how precarious that interface can be. Poultry showed the highest burden of reported disease, affecting 52.9 percent of households that kept them, with outbreaks consistent with Newcastle disease and respiratory infections dominating the reports. Cattle were the second most affected, at 43.6 percent, with tick infestations, internal parasites, fever and, notably, vampire bat bites and suspected bovine rabies among the documented problems. Dogs suffered from distemper, undetermined infections and mange, while pigs, guinea pigs, horses and cats reported lower but non-trivial disease levels. In a region where veterinary services are scarce and sanitary protocols are poorly known, the authors argue, these conditions create ideal circumstances for communicable diseases to persist and circulate at the wildlife-livestock-human boundary, echoing findings from Rondônia, Brazil, where high parasite prevalence in domestic dogs facilitates pathogen spread to livestock and people.

Perhaps the study’s most striking quantitative result concerns predation. Of the 12 documented wildlife hunting events attributed to domestic animals, dogs were responsible for 83.3 percent, a proportion significantly higher than that of cats, which accounted for the remaining 16.7 percent and hunted only parrots. The statistical comparison yielded an odds ratio of 25.0 with a Fisher’s exact test p-value of 0.0033, a robust signal despite the modest number of events. Dog prey ranged widely across the vertebrate spectrum, from parrots and hummingbirds to monkeys, a sloth and a deer. Free-roaming and semi-domestic dogs are increasingly recognised across Amazonia and other tropical regions as significant predators of birds and small mammals, and their activity patterns often overlap with those of vulnerable wildlife, multiplying opportunities for lethal encounters that rarely appear in official conservation statistics.

Wildlife was far from absent in the agricultural landscape itself. The frequency distribution of species observed in chacras was highly skewed, with a chi-square test of 480.84 and p less than 0.001 confirming that sightings were far from homogeneous across taxonomic groups. Agoutis were reported by 70.8 percent of farming families and parrots by 56.3 percent, while primates appeared in 35.4 percent of households’ observations. Carnivores such as the ocelot and vampire bats were rarely seen, at less than 2 percent of families. The authors interpret this as evidence that Corosha’s agricultural mosaic retains substantial ecological value, consistent with broader Amazonian research showing that bird richness in agroforestry systems depends on proximity to forest and that generalist groups such as parrots and rodents thrive even in landscapes with moderately complex vegetation.

Perceptions, however, told a more conflicted story. Negative views of wildlife predominated at 63.2 percent of respondents, driven overwhelmingly by crop damage, which 51.6 percent of all participants cited. Rodents, including the paca and agouti, were the primary villains, implicated by 49.7 percent of respondents, followed by parrots at 33.5 percent. Positive perceptions were rare, at 16.8 percent, and mostly attached to charismatic or culturally significant species such as the Andean bear, the toucan and certain game birds like guans. Monkeys and hummingbirds attracted mixed feelings, blending aesthetic appreciation with practical grievances. Notably, the study detected a significant gender-based disparity in perception patterns, with women reporting more negative and mixed interactions than men, a Fisher’s exact test confirming the difference at p less than 0.05. Since women dominate both farming and household animal care in Corosha, they sit squarely at the front line of human-wildlife friction.

The authors frame these interconnected findings through a One Health lens, the framework that recognises the inseparable health of people, domestic animals and ecosystems. Their recommendations are concrete: participatory crop protection to reduce losses to rodents and parrots without resorting to hunting, community-based animal health programmes offering vaccination and parasite control, and environmental education that highlights the ecological roles of so-called pest species, many of which, like agoutis, are vital seed dispersers supporting forest regeneration. The alternative, the study suggests, is a spiral in which crop losses harden attitudes, attitudes justify retaliation, and retaliation erodes the biodiversity that makes landscapes like Corosha ecologically valuable in the first place.

What makes the Corosha study resonate beyond its mountain valleys is its methodological ambition. Rather than isolating a single conflict species or cataloguing crop damage alone, it connects livelihoods, animal husbandry, predation records and perception data within one analytical frame, revealing how tightly these threads are braided. A dog carried to a chacra is simultaneously a guardian, a disease vector and an unrecognised predator; a parrot is a cultural treasure and a maize thief; a woman tending tubers is a farmer, a wildlife observer and the community’s most reliable witness to all of it. For conservationists seeking sustainable co-existence in the Amazon’s biodiversity hotspots, the message from Corosha is clear: any strategy that ignores domestic animals, gendered labour or local attitudes is likely to fail, while integrated approaches that address all three simultaneously offer the best chance of keeping both farms and forests alive.

Subject of Research: Human–wildlife interactions, domestic animal predation and local perceptions in a rural Peruvian Amazonian community

Article Title: Human–wildlife interactions in a rural Amazonian community: Linking productive land use, domestic animals and local perceptions

Article References: Carlos, N., & Cornejo, F. M. (2026). Human–wildlife interactions in a rural Amazonian community: Linking productive land use, domestic animals and local perceptions. Neotropical Biology and Conservation, 21(3), 245-260. https://doi.org/10.3897/neotropical.21.e178289

Image Credits: AI Generated

DOI: 10.3897/neotropical.21.e178289

Keywords: human-wildlife conflict, Peruvian Amazon, One Health, domestic dogs, crop damage, subsistence agriculture, wildlife perceptions, animal health, conservation, Corosha, chacras, zoonotic disease

The challenge the researchers set out to address is familiar to every elimination program. As transmission falls, infected individuals increasingly carry very small numbers of parasites in their blood, often below the threshold that a microscopist examining a blood smear can reliably detect. These submicroscopic infections still contribute to onward transmission, because mosquitoes that feed on an infected person can pick up gametocytes even when the density of parasites in the peripheral blood is tiny. In settings such as the Amazon basin, where P. vivax in particular hides in the liver and re-emerges in relapses, missing these infections allows reservoirs of disease to persist in communities that appear, on paper, to be approaching elimination.

Loop-mediated isothermal amplification was developed as a molecular diagnostic that avoids the thermal cycling equipment required by conventional PCR. Instead of repeatedly heating and cooling a sample, LAMP uses a strand-displacing DNA polymerase and four to six specially designed primers that recognize six to eight distinct regions of the target genome. The reaction proceeds at a constant temperature, typically around 60 to 65 degrees Celsius, which can be maintained by a simple heating block or even a water bath. Amplification produces enormous quantities of pyrophosphate and protons as byproducts, and in a colorimetric formulation a pH-sensitive dye shifts color when the reaction succeeds, turning a positive result into something a technician can read with the naked eye.

That simplicity is what makes cLAMP attractive for field surveillance, but the technology has a well-known Achilles heel: sample preparation. DNA extraction remains the most technically demanding and contamination-prone step in any molecular assay, and the choice of extraction method can dominate overall performance. The Peruvian team confronted this directly by comparing two approaches on the same samples. The first was a mini spin column method, in which DNA is bound to a silica membrane, washed, and eluted in clean buffer, a process that concentrates and purifies genetic material but requires more reagents, equipment, and hands-on time. The second was a boil-and-spin method, in which a small piece of dried blood is simply heated in water or buffer to release DNA, then briefly centrifuged to pellet debris, leaving crude lysate ready for amplification.

The samples came from two complementary surveillance strategies that elimination programs run in parallel. Active case detection, abbreviated ACD, involves health workers visiting communities and screening people regardless of whether they feel ill, in order to flush out asymptomatic carriers. Passive case detection, or PCD, relies on patients who come to a clinic with fever or other symptoms. The study analyzed 574 dried blood spots from active detection and 431 from passive detection. Dried blood spots themselves are a surveillance workhorse: a finger-prick of blood spotted onto filter paper, dried, and stored, they are cheap to collect, stable at ambient temperatures for weeks to months, and far easier to transport from remote river communities to a laboratory than whole blood or slides.

To judge how well cLAMP performed, the researchers benchmarked it against two references. Real-time quantitative PCR, or qPCR, served as the molecular gold standard, while microscopy represented the current reality of most field diagnosis. The gap between the two was stark. In the active detection set, qPCR identified 125 positive samples, 117 of them P. vivax and 8 P. falciparum. Microscopy, run against that standard, achieved a sensitivity of only 57.6 percent, meaning it missed more than four in ten infections that were genuinely present. cLAMP with the crude boil-and-spin extraction did somewhat better, reaching 63.2 percent sensitivity, while cLAMP paired with the spin column extraction climbed to 82.4 percent, a dramatic improvement over the smear.

The passive detection samples told a related but distinct story. Here qPCR found 140 positives, comprising 129 P. vivax infections, 9 P. falciparum infections, and 2 mixed infections containing both species. Because symptomatic patients generally carry higher parasite densities, microscopy fared better in this group, achieving 72.9 percent sensitivity. cLAMP with boil-and-spin extraction reached 77.1 percent, roughly comparable to the smear, while the column-based extraction again pushed sensitivity to 82.1 percent. Across both surveillance modes and all diagnostic methods, specificity remained above 99 percent, indicating that false positives were vanishingly rare and that a positive result could be trusted as a true infection.

The pattern in these numbers carries a clear technical message. The amplification chemistry itself is sensitive enough, but its real-world performance is gated by the quality of the DNA template fed into it. Boil-and-spin extraction releases parasite DNA but also carries blood-derived inhibitors and leaves the template dilute, which hurts most precisely where sensitivity matters most: in the low-density, often asymptomatic infections found by active case detection. Column-based extraction cleans and concentrates the template, and the benefit shows up disproportionately in the ACD samples, where cLAMP with columns outperformed microscopy by nearly 25 percentage points. In passive surveillance, where parasite densities run higher, the extraction method mattered less because even crude lysate contained enough template for the reaction to succeed.

For program managers weighing options in low-transmission settings, the study frames a trade-off rather than a single verdict. Boil-and-spin cLAMP is cheaper, faster, and simpler, and it performs at least as well as microscopy, making it a plausible upgrade for laboratories that cannot sustain column-based workflows. Column-based cLAMP, meanwhile, delivers sensitivity approaching qPCR from a filter paper sample, without needing a thermocycler or fluorescent detection hardware, and it substantially outperforms the smear in exactly the active surveillance campaigns where finding hidden infections is the whole point. Because the readout is a visible color change, results do not require expensive instruments, and the isothermal reaction can run on basic laboratory equipment already common in regional health posts.

The authors conclude that cLAMP, particularly when combined with column-based DNA extraction, is a practical and sensitive complementary tool for malaria surveillance in elimination settings. As countries in the Amazon and beyond push toward the last mile of malaria elimination, the infections that matter are the ones nobody can see under a microscope, and tools that can find them cheaply, reliably, and close to the communities where they occur will determine whether the final stretch of the campaign succeeds. This study suggests that a color-changing tube, a filter paper spot, and a careful choice of extraction chemistry may be enough to bring molecular-grade detection out of the reference laboratory and into the field.

Subject of Research: Evaluation of colorimetric loop-mediated isothermal amplification for malaria detection from dried blood spots in the Peruvian Amazon

Article Title: Detection of Plasmodium vivax and Plasmodium falciparum using colorimetric loop-mediated isothermal amplification from dried blood spots collected in active and passive malaria surveillance in the Peruvian Amazon

Article References: Nolasco, O., Gómez, J., Rodríguez-Ferrucci, H., Gamboa, D., & Delgado-Ratto, C. (2026). Detection of Plasmodium vivax and Plasmodium falciparum using colorimetric loop-mediated isothermal amplification from dried blood spots collected in active and passive malaria surveillance in the Peruvian Amazon. PLOS Neglected Tropical Diseases, 20(10), e0014366. https://doi.org/10.1371/journal.pntd.0014366

Image Credits: AI Generated

DOI: 10.1371/journal.pntd.0014366

Keywords: malaria, Plasmodium vivax, Plasmodium falciparum, LAMP, colorimetric assay, dried blood spots, molecular diagnostics, active case detection, passive case detection, Peruvian Amazon, malaria elimination, DNA extraction

Resource insecurity is a growing concern for Indigenous populations worldwide, many of whom depend directly on local ecosystems for food, water, and livelihoods. Climate change, deforestation, mining, and infrastructure development are altering the hydrological and ecological foundations of these livelihoods at unprecedented speed. Yet the relationship between access to water and access to food is rarely studied together, despite the obvious practical connections between the two. Drawing water, purifying it, and transporting it all consume time, energy, and health; when any of those resources are stretched thin, the ability to procure and prepare diverse foods can suffer. The new study set out to quantify precisely these linkages in an Awajún population for whom both water and food systems remain closely tied to the surrounding forest and rivers.

The researchers analyzed cross-sectional data from 212 Awajún adults, using linear and logistic regression models with robust standard errors to test associations between water insecurity, food insecurity, and dietary diversity. Water insecurity was assessed through a composite score as well as through individual indicators capturing distinct lived experiences, such as being unable to collect water because of distance, being unable to collect water due to illness or weakness, going for extended periods without drinking water, and not boiling water before use. Food insecurity was likewise measured with a validated score, while dietary diversity captured the variety of foods consumed, a widely used proxy for overall diet quality. This dual approach, combining a composite index with its component indicators, proved to be the study’s most consequential methodological decision.

The results confirmed that both food and water insecurity are prevalent among the Awajún, a finding that may surprise outsiders who imagine the Amazon as a landscape of limitless water. Abundance in the environment does not guarantee access at the household level. Rivers and streams may be contaminated, distant, or dangerous to reach, and seasonal variation can leave families dependent on sources that are unreliable for months at a time. The study’s statistical models showed that these everyday struggles with water translate directly into struggles with food, even after adjusting for other factors.

In adjusted linear regression models, higher composite water insecurity scores were significantly associated with higher food insecurity scores, with a beta coefficient of 0.24 and a 95 percent confidence interval of 0.11 to 0.36, and a p-value below 0.001. In practical terms, this means that as Awajún adults experienced more severe and more frequent water problems, their food insecurity rose in a predictable, measurable way. The association was independent of other variables in the model, strengthening the case that water insecurity is not merely a symptom of general poverty but a distinct driver of hunger. Interestingly, however, the composite water insecurity score was not significantly associated with dietary diversity, suggesting that the aggregated measure was averaging away some of the most important signals.

That is where the component-level analysis became revelatory. When the researchers disaggregated the composite score, individual indicators turned out to be more strongly associated with food insecurity and dietary diversity than the composite measure itself. Being unable to collect water due to distance was associated with a 0.61-point increase in food insecurity scores (95 percent CI: 0.19 to 1.03; p = 0.005). Being unable to collect water due to illness or weakness showed an even stronger association, with a beta of 0.68 (95 percent CI: 0.20 to 1.16; p = 0.006). Not boiling water before drinking was associated with a 0.60-point increase in food insecurity (95 percent CI: 0.15 to 1.05; p = 0.009). Each of these associations was stronger than the one observed for the composite score, indicating that specific, concrete hardships carry more statistical and practical information than a blended index.

Perhaps the most striking result concerned dehydration. Going for extended periods of time without drinking water was associated with lower dietary diversity scores, with a beta of -0.79 and a 95 percent confidence interval of -1.43 to -0.16 (p = 0.01). This inverse relationship hints at a physiological and behavioral cascade: people who cannot drink enough water may reduce their consumption of foods that are difficult to eat or digest without adequate hydration, or they may lack the energy to prepare varied meals. It may also reflect that households facing the most acute water deprivation are those whose entire subsistence system, from farming to fishing to forest gathering, is under strain. Whatever the precise mechanism, the finding links an extreme form of water deprivation to the quality of the diet itself, not just its quantity.

The authors argue that these findings carry significant implications for how governments and aid organizations monitor and address resource insecurity in vulnerable populations. Composite scores, while useful for standardization and cross-cultural comparison, can dilute the signal of specific experiences that are both more measurable in practice and more actionable in policy. A survey that records only an aggregate water insecurity number might miss the fact that distance to water, physical illness, and lack of water treatment are each distinct levers for intervention. Building a well closer to a community addresses one indicator; a mobile water delivery program for sick or elderly residents addresses another; a boiling or filtration campaign addresses a third. The study suggests that tracking these dimensions separately could sharpen the targeting and evaluation of such programs.

The research also speaks directly to the United Nations Sustainable Development Goals, particularly SDG 6 on clean water and sanitation and SDG 2 on zero hunger. Progress toward these goals is often measured and pursued separately, with water programs in one ministry and nutrition programs in another. The Awajún data demonstrate that in Indigenous Amazonian communities, the two agendas are empirically inseparable: water insecurity predicts food insecurity, and specific water deprivations shape dietary quality. Interventions that treat water access as a food security strategy, and vice versa, are likely to outperform siloed approaches. For health surveillance systems, the message is equally clear: questionnaires that capture the lived, granular experiences of water hardship, such as walking long distances, collecting water while ill, or going hours without a drink, may identify at-risk households that aggregate indices overlook.

Beyond its policy relevance, the study is a methodological caution for the growing field of water insecurity research. As instruments like composite water insecurity scales are deployed across dozens of countries, researchers have tended to report the headline score. This analysis shows that the components of such scores can behave differently, and sometimes more powerfully, than the sum of their parts. For the Awajún, whose food systems and water systems are bound together by rainforest ecology, by the labor of collection, and by the daily decisions of households, the path to both clean water and adequate food runs through the same small, hard details of ordinary life. Recognizing those details, the authors suggest, is the first step toward measuring them, and measuring them is the first step toward fixing them.

Subject of Research: Associations between water insecurity, food insecurity, and dietary diversity among Indigenous Awajún adults in the Peruvian Amazon

Article Title: Water insecurity, food insecurity, and dietary diversity among Awajún adults living in the Peruvian Amazon

Article References: Tallman, P. S., & Collins, S. M. (2026). Water insecurity, food insecurity, and dietary diversity among Awajún adults living in the Peruvian Amazon. PLOS Water, 5(9), e0000556. https://doi.org/10.1371/journal.pwat.0000556

Image Credits: AI Generated

DOI: 10.1371/journal.pwat.0000556

Keywords: water insecurity, food insecurity, dietary diversity, Awajún, Peruvian Amazon, Indigenous health, PLOS Water, Sustainable Development Goals, clean water access, nutrition surveillance, resource insecurity, Water

The research, conducted by Peter Coaguila-Rodriguez and Alberto Franco Cerna-Cueva of the Universidad Nacional Agraria de la Selva in Tingo María, Huánuco, set out to answer a deceptively simple question: can ordinary soil chemistry measurements predict which samples will show aluminium saturation at or above 20 percent, a threshold commonly associated with high or very high toxicity risk? To do so, the team turned to an anonymized institutional soil-monitoring database containing 1,842 records from cacao-growing areas of the central Peruvian Amazon. After filtering for acidity, 1,539 samples with pH below 5.5 formed the analytical cohort, a substantial dataset for a region where such comprehensive soil records are rare.

Aluminium saturation is defined as the proportion of the soil’s exchangeable cation exchange capacity occupied by aluminium rather than by base cations such as calcium, magnesium and potassium. As soils acidify, base cations are leached away and aluminium increasingly dominates the exchange complex, which is why the metric serves as a direct chemical indicator of the intensity of acid-soil stress a plant will experience. Cacao, a crop native to the upper Amazon and economically vital to Peru, is known from prior ecophysiological work to be sensitive to soil acidity, with juvenile plants showing impaired growth and altered nutrition under acidic conditions. Yet the full exchangeable-acidity analysis needed to compute saturation requires titration procedures that many regional laboratories do not routinely offer, whereas pH, organic matter and exchangeable bases are standard fare.

The researchers built six logistic-regression models, comparing predictors drawn from routine soil tests against covariates derived from two publicly available gridded data products: PISCOp, Peru’s high-resolution interpolated rainfall dataset, and SoilGrids, a global digital soil mapping product. The outcome variable in every case was the laboratory-reported aluminium saturation value, dichotomized at the 20 percent threshold. Logistic regression, a workhorse of applied statistics, estimates the probability of a binary outcome as a function of predictor variables, making it well suited to a screening task where the goal is to flag samples for follow-up rather than to measure toxicity directly.

What distinguishes the study methodologically is the rigor of its validation design. All preprocessing steps and the selection of the decision threshold were nested inside a fivefold grouped cross-validation scheme, meaning that the data transformations and cutoff choices were re-learned within each training fold rather than tuned on the full dataset. The grouping was based on surrogate environmental signatures, a strategy designed to prevent information leakage between samples drawn from similar environments, a well-known pitfall in spatially structured ecological and soil data. This kind of careful cross-validation is essential when records may cluster by farm, soil type or microregion, because otherwise a model can appear far more accurate than it truly is when deployed on genuinely new locations.

The performance of the simplest model, built entirely from routine soil test variables, was striking. Across pooled cross-validation folds it achieved a balanced accuracy of 0.876, with a fold-level standard deviation of 0.022 and a group-bootstrap 95 percent confidence interval of 0.856 to 0.896. Balanced accuracy, the average of sensitivity and specificity, is a robust metric when the two outcome classes are unevenly represented. The model’s sensitivity, its ability to correctly flag samples that truly exceed the 20 percent threshold, was 0.868, while its specificity, the ability to correctly clear samples below the threshold, was 0.885. Perhaps most importantly for a screening application, the positive predictive value reached 0.952, meaning that when the model flags a sample as high-risk, that flag is very likely to be confirmed by the full laboratory determination.

Additional metrics reinforced the picture of a well-calibrated classifier. The area under the receiver-operating-characteristic curve, which summarizes discrimination across all possible thresholds, was 0.936, and the area under the precision-recall curve, often more informative when positive cases are the minority, was 0.968. The Brier score, a measure combining discrimination and calibration that penalizes both wrong predictions and misplaced confidence, came in at 0.082, with lower values indicating better overall probabilistic accuracy. Together these figures indicate that routine soil chemistry carries a strong, quantifiable signal about aluminium saturation, enough to triage samples with a high degree of confidence before committing resources to confirmatory analysis.

Just as revealing is what the study found when it added the gridded environmental covariates. Relative to the routine model, the difference in balanced accuracy was 0.000, with a 95 percent confidence interval of −0.010 to 0.010, when PISCOp rainfall covariates were included, and −0.007, with an interval of −0.020 to 0.005, when PISCOp and SoilGrids were combined. In other words, the authors found no evidence of a stable improvement from the remotely sensed and interpolated data layers within the spatial support available. This is a noteworthy result in a field where digital soil mapping and machine learning covariates are frequently promoted as enhancements to local prediction, and it suggests that for this specific screening task, at this spatial resolution, the chemistry already measured in routine tests contains most of the relevant information.

The authors are careful to delineate what the model can and cannot do, and these caveats matter for anyone hoping to apply it. The tool is intended to prioritize confirmatory aluminium-saturation analysis in comparable acidic cacao soils, not to measure plant toxicity directly, not to replace laboratory diagnosis and not to support continuous zoning or mapping of unsampled areas. Aluminium saturation in a soil sample is a chemical property, not a biological endpoint, and actual toxicity to a given cacao genotype depends on root architecture, cultivar-specific tolerance mechanisms and management history. The model’s value lies in triage: laboratories and extension services with limited budgets can use routine test results to decide which samples genuinely need the more elaborate exchangeable-acidity workup, concentrating scarce analytical capacity where it is most likely to change management decisions.

The practical implications extend across the tropical cacao belt, where acid soils cover vast areas and liming decisions hinge on knowing where aluminium stress is severe. Acid soils are estimated to occupy a large share of the world’s potentially arable land, and aluminium toxicity is among the principal chemical constraints on crop production in these regions. A screening approach that leverages data already flowing through regional monitoring programs could accelerate the identification of high-risk fields without new instrumentation or new sampling campaigns. The study’s data and code are available from the corresponding authors upon reasonable request, subject to the confidentiality restrictions of the institutional monitoring database, and the work received no external funding. For the farmers of the central Peruvian Amazon, and potentially for cacao producers far beyond it, the message is quietly transformative: the answers to one of tropical agriculture’s most stubborn soil problems may already be sitting in the routine test reports that laboratories produce every day.

Subject of Research: Predictive screening of high aluminium saturation in acidic cacao soils of the Peruvian Amazon using routine soil test data and logistic regression

Article Title: Routine soil tests support screening of high aluminium saturation in acidic cacao soils

Article References: Coaguila-Rodriguez, P., & Cerna-Cueva, A. F. (2026). Routine soil tests support screening of high aluminium saturation in acidic cacao soils. Environmental Monitoring and Assessment, 198(10), Article 1105. https://doi.org/10.1007/s10661-026-15945-3

Image Credits: AI Generated

DOI: 10.1007/s10661-026-15945-3

Keywords: soil acidity, aluminium saturation, Theobroma cacao, Peruvian Amazon, logistic regression, soil screening, cross-validation, digital soil mapping, SoilGrids, PISCOp, environmental monitoring, soil chemistry

The research, published in the journal Discover Psychology, was conducted by a team at the Escuela de Psicología of the Universidad Peruana Unión in Tarapoto, Peru. Lead author Alexandra Asto-Janampa and colleagues, including corresponding author Calixto Tapullima-Mori, set out to answer a question that had not previously been examined empirically: if unfinished business is associated with a diminished sense of meaning in life, what regulatory mechanisms might explain part of that association? Their focus fell on cognitive emotion regulation strategies, the conscious mental tactics people deploy to manage the emotional impact of stressful or negative events.

Cognitive emotion regulation strategies are typically divided into two broad families. Adaptive strategies include putting situations into perspective, positive reappraisal, positive refocusing, refocusing on planning, and acceptance—mental moves that reframe or reorganize a stressful experience in ways that tend to protect psychological well-being. Maladaptive strategies, by contrast, include self-blame, other-blame, rumination or focusing on thoughts and feelings, and catastrophizing, all of which are generally associated with poorer emotional outcomes. The Peruvian team wanted to know which of these two families, if either, acts as the hidden pathway connecting unresolved past experiences to a person’s sense of meaning.

To investigate, the researchers carried out a cross-sectional explanatory study with an associative strategy, recruiting 617 university students in the San Martín Region of the Peruvian Amazon. Participants had a mean age of 22.1 years with a standard deviation of 3.6, and 54.0 percent were women. Recruitment used convenience sampling with a snowball component, in which initial participants helped identify others eligible for the study. The study received ethics approval from the Research Ethics Committee of the Universidad Peruana Unión under Resolution No. 0421-T-2025/UPeU-FCS-CF and was conducted in accordance with the principles of the Declaration of Helsinki. Informed consent was obtained electronically before questionnaires were administered, participation was voluntary, anonymous and unremunerated, and all participants were of legal age.

On the analytical side, the team used structural equation modeling with a maximum likelihood robust estimator, a technique that allows researchers to test networks of relationships among latent psychological constructs while guarding against deviations from normality in the data. To probe indirect pathways, they ran mediation analyses built on 5,000 bias-corrected bootstrap resamples, a resampling procedure that generates confidence intervals for indirect effects without relying on assumptions that those effects follow a normal distribution. An indirect effect is considered statistically significant when its 95 percent confidence interval does not cross zero. Both of the structural models tested in the study showed acceptable fit to the data.

The headline finding concerns the adaptive strategies, and it is anything but straightforward. Students who reported more unfinished business also reported greater use of adaptive cognitive emotion regulation strategies, and those strategies in turn were positively associated with meaning in life. The indirect pathway through adaptive strategies was positive and significant, with a standardized coefficient of 0.087 and a 95 percent confidence interval running from 0.055 to 0.126. Yet the direct association between unfinished business and meaning in life was negative, at −0.202, and the total association was also negative, at −0.115. In other words, the indirect effect and the direct effect pointed in opposite directions.

That sign reversal is what methodologists call an inconsistent mediation, or a suppression pattern, and the authors are careful to stress that it is not the ordinary partial mediation familiar from most psychology papers. In a classic partial mediation, the indirect pathway carries the same sign as the direct effect and simply accounts for a portion of it. Here, the adaptive strategies appear to work against the direct negative association, offsetting part of the damage that unfinished business does to perceived meaning. The total effect of −0.115 is smaller in magnitude than the direct effect of −0.202 precisely because the positive indirect effect of 0.087 is subtracting from it. The practical implication is striking: without the mobilization of adaptive regulation, the association between unresolved experiences and diminished meaning would have been substantially stronger.

The story for maladaptive strategies is different. The indirect association through the maladaptive family was small and not statistically significant, with a coefficient of 0.026 and a 95 percent confidence interval spanning from −0.027 to 0.078, a range that includes zero. Whatever role rumination, self-blame, or catastrophizing play in the lives of these students, the data did not support the idea that they form a measurable bridge between unfinished business and meaning in life. The suppression effect, in this sample, belongs entirely to the adaptive side of the regulatory ledger.

The authors interpret this pattern as suggesting that adaptive cognitive emotion regulation may operate as a compensatory resource, one that is mobilized in response to unresolved experiences rather than being a simple conduit through which those experiences exert their influence. On this reading, encountering unfinished business does not merely erode meaning; it also triggers a regulatory response. Students who respond by reappraising, accepting, planning, and putting things into perspective recover part of the ground that unresolved experiences would otherwise claim. Those who lack or fail to deploy such strategies may bear the full weight of the direct negative association. The finding resonates with a broader theme in emotion science: regulation is not only a trait-like capacity but also a dynamic process recruited by adversity itself.

As with any cross-sectional study, the design captures associations at a single point in time, so the direction of the pathways cannot be established with certainty, and the convenience sampling with a snowball component means the sample may not represent all young adults in the region. Still, the study is the first to examine these regulatory mechanisms empirically in this population, and its suppression finding carries a genuinely hopeful message for university communities in the Peruvian Amazon and beyond. Unfinished business, the data suggest, exacts a real toll on how much meaning students find in their lives, but the human capacity for adaptive cognitive regulation is not a bystander to that process—it is an active counterweight. Interventions that strengthen reappraisal, acceptance, and planning skills may help young adults convert unresolved past experiences from silent burdens into catalysts for reflection, closing a few of the open loops that otherwise keep meaning out of reach.

Subject of Research: Cognitive emotion regulation strategies as a suppressive mediator between unfinished business and meaning in life among Peruvian university students

Article Title: Cognitive emotion regulation strategies in the association between unfinished business and meaning in life among Peruvian university students: an inconsistent (suppression) mediation model

Article References: Asto-Janampa, A., Algarate-Rubio, P. N., Tafur-Becerra, Y. A., Mayta-Llanos, J., & Tapullima-Mori, C. (2026). Cognitive emotion regulation strategies in the association between unfinished business and meaning in life among Peruvian university students: an inconsistent (suppression) mediation model. Discover Psychology. https://doi.org/10.1007/s44202-026-00890-6

Image Credits: AI Generated

DOI: 10.1007/s44202-026-00890-6

Keywords: unfinished business, cognitive emotion regulation, meaning in life, suppression effect, mediation analysis, university students, Peruvian Amazon, structural equation modeling, adaptive strategies, maladaptive strategies, psychology, San Martín Region

The retrospective study covered January 2023 through October 2025 and began with a hospital-wide sweep of emergency department and inpatient records carrying any ICD-10 malaria code. Of 519 laboratory-confirmed malaria diagnoses recorded during the period, 428 (82.5 percent) were P. vivax, 88 (17.0 percent) were P. falciparum, two were mixed infections, and one was P. malariae. From this pool, 127 patients met the analytic criteria: microscopy-confirmed malaria, at least one dose of intravenous artesunate given for severe disease or inability to tolerate oral therapy, survival of at least 24 hours after admission, and laboratory results available at two or more time points. Notably, 22.7 percent of vivax patients and 30.7 percent of falciparum patients entered the cohort, a proportion of hospitalization far higher than the 1.6 to 3.2 percent reported in earlier Peruvian and Brazilian Amazonian series.

The headline result is stark in its symmetry. Severe malaria, defined by at least one criterion from the 2022 WHO guidelines, occurred in 51 of 97 vivax patients (52.6 percent) and 14 of 27 falciparum patients (51.9 percent). That equivalence emerged despite a marked asymmetry in underlying vulnerability: recognized risk factors or comorbidities were recorded in 59.3 percent of falciparum patients but only 26.8 percent of vivax patients, a difference largely driven by pregnancy. In other words, vivax patients reached comparable severity with a lighter load of predisposing conditions, suggesting that the parasite itself, rather than patient frailty, was driving the clinical picture.

The spectrum of severity criteria also overlapped substantially between species. Prostration and altered consciousness were the most frequent clinical manifestations, while severe anaemia led the biochemical criteria. Sixty-six of the 67 patients who ultimately fulfilled a severity criterion already met one at admission, but nine patients developed new or recurrent WHO-recognized manifestations during hospitalization, including impaired consciousness, shock, metabolic acidosis, jaundice, severe anaemia, haemoglobinuria and renal impairment at various time points after admission. The authors argue that this longitudinal evolution supports continued clinical and laboratory reassessment throughout the hospital stay, even though formal repeated screening against all criteria is not mandated by current WHO guidance.

Laboratory data reinforced the impression that vivax malaria is haematologically aggressive. At baseline, patients with severe disease had significantly lower haemoglobin and haematocrit values than non-severe patients, and haemoglobin remained lower in severe cases after treatment. In non-severe malaria, falciparum infection was actually associated with a less favourable baseline profile, with lower haemoglobin and haematocrit than vivax. Strikingly, platelet counts were significantly higher in falciparum infections in both severity strata, echoing prior reports that thrombocytopenia in vivax malaria can be as marked as, or more marked than, that seen in falciparum disease, and often out of proportion to the peripheral parasite density visible on a blood smear.

That dissociation between circulating parasites and clinical damage has a plausible biological explanation. Human splenectomy studies have shown that P. vivax–infected erythrocytes accumulate alongside immature reticulocytes in the red pulp of the spleen, creating a hidden reservoir that peripheral microscopy systematically undercounts. A larger total parasite biomass has been linked to thrombocytopenia, inflammatory activation, endothelial dysfunction and disruption of the vascular glycocalyx. Endothelial activation in acute vivax malaria is pronounced and associated with impaired microvascular reactivity and reduced tissue perfusion, and unlike in severe falciparum malaria it does not appear to be driven by intravascular haemolysis, pointing instead to depleted arginine and nitric oxide bioavailability as a key pathway toward organ dysfunction.

The relapsing biology of P. vivax adds a cumulative dimension to its threat. Reactivation of dormant hepatic hypnozoites or release of parasites from extravascular reservoirs can produce recurrent episodes before haematological recovery is complete, progressively eroding haemoglobin reserves and nutritional status and priming patients for severe disease in later attacks. This mechanism may be especially relevant in the Peruvian Amazon, where vivax predominates and more than half of the study patients, 52.8 percent, reported previous malaria episodes. Evidence from Indonesia suggests that although early mortality after a first episode is higher with falciparum, the mortality gap narrows and may even reverse after repeated vivax infections.

Treatment outcomes in the cohort were generally favourable. The median time to parasite clearance after intravenous artesunate was 48 hours, with no substantial difference by severity, and 93.3 percent of the 89 patients evaluated at 72 hours had completely cleared parasites on smear. The median hospital stay was five days, and all surviving patients were switched to oral antimalarial therapy after parenteral treatment. Yet the study also exposed gaps in pre-hospital care: 60.6 percent of patients had received no antimalarial treatment before admission, and 14.2 percent had been given empirical therapy with no antimalarial activity, a pattern at odds with WHO recommendations for prompt effective treatment after diagnosis.

The single death in the cohort underscores how conventional severity criteria can fail pregnant patients. A pregnant woman with falciparum malaria, admitted eight days after symptom onset, met neither clinical nor biochemical severity criteria at admission and had a normal platelet count. Roughly 48 hours after starting artesunate, her platelets had collapsed from 253 to 36 thousand per microlitre, she remained parasitaemic, and moderate anaemia persisted. She suffered foetal loss on hospital day five, followed by massive obstetric haemorrhage, and died the next day despite timely obstetric intervention and transfusion. The authors note that while the recorded cause of death was uterine haemorrhage, falciparum infection in pregnancy is an established cause of stillbirth, and the case illustrates how difficult it can be to disentangle immediate from contributing causes of maternal death.

Coinfections added further complexity to the clinical landscape. Dengue was identified in 14 patients, eight with severe and six with non-severe malaria, alongside two cases of bacterial sepsis and one of leptospirosis, while intestinal parasitosis was detected in 21 patients. Previous work has suggested that dengue–malaria coinfection may worsen haematological complications, though the small number of coinfected cases here precluded any conclusion. The authors also acknowledge the limits of their retrospective, single-centre design: incomplete follow-up laboratories, cultures obtained only when infection was clinically suspected, reliance on microscopy with limited sensitivity for low-level or mixed infections, and the likelihood that the most severely ill patients died before ever reaching the hospital. Even so, the central message stands. In this low-transmission Amazonian setting, P. vivax carried a burden of WHO-defined severe malaria comparable to P. falciparum, with broadly similar clinical, laboratory and parasitological profiles, and the authors conclude that both locally prevalent species warrant the same degree of clinical vigilance.

Subject of Research: Comparative severity of Plasmodium vivax and Plasmodium falciparum malaria in hospitalized patients in the Peruvian Amazon

Article Title: Comparable severity of Plasmodium vivax and Plasmodium falciparum malaria in hospitalized patients in the Peruvian Amazon

Article References: Bresciani, L., Guardiani, M., Rojas-Blasquez, M., Ramirez, E., Iaquinandi, S., Martel, C., Velarde-Mera, M., Sifuentes-Vidigal, S., Carraro, A., Russo, G., Pasquazzi, C., Celis, J. C., Casapia Morales, M., Nicastri, E., Asayag, C. R., Lichtner, M., & Vita, S. (2026). Comparable severity of Plasmodium vivax and Plasmodium falciparum malaria in hospitalized patients in the Peruvian Amazon. New Microbes and New Infections, 73, Article 101849. https://doi.org/10.1016/j.nmni.2026.101849

Image Credits: AI Generated

DOI: 10.1016/j.nmni.2026.101849

Keywords: malaria, Plasmodium vivax, Plasmodium falciparum, severe malaria, Peruvian Amazon, WHO severity criteria, intravenous artesunate, thrombocytopenia, severe anaemia, malaria in pregnancy, parasite clearance, endothelial dysfunction