The Role of Latin America’s Land and Water Resources for Global Food Security: Environmental Trade-Offs of Future Food Production Pathways

One of humanity’s major challenges of the 21st century will be meeting future food demands on an increasingly resource constrained-planet. Global food production will have to rise by 70 percent between 2000 and 2050 to meet effective demand which poses major challenges to food production systems. Doing so without compromising environmental integrity is an even greater challenge. This study looks at the interdependencies between land and water resources, agricultural production and environmental outcomes in Latin America and the Caribbean (LAC), an area of growing importance in international agricultural markets. Special emphasis is given to the role of LAC’s agriculture for (a) global food security and (b) environmental sustainability. We use the International Model for Policy Analysis of Agricultural Commodities and Trade (IMPACT)—a global dynamic partial equilibrium model of the agricultural sector—to run different future production scenarios, and agricultural trade regimes out to 2050, and assess changes in related environmental indicators. Results indicate that further trade liberalization is crucial for improving food security globally, but that it would also lead to more environmental pressures in some regions across Latin America. Contrasting land expansion versus more intensified agriculture shows that productivity improvements are generally superior to agricultural land expansion, from an economic and environmental point of view. Finally, our analysis shows that there are trade-offs between environmental and food security goals for all agricultural development paths.     

Food or just a free ride? A meta-analysis reveals the global diversity of the Plastisphere

It is now indisputable that plastics are ubiquitous and problematic in ecosystems globally. Many suggestions have been made about the role that biofilms colonizing plastics in the environment—termed the “Plastisphere”—may play in the transportation and ecological impact of these plastics. By collecting and re-analyzing all raw 16S rRNA gene sequencing and metadata from 2,229 samples within 35 studies, we have performed the first meta-analysis of the Plastisphere in marine, freshwater, other aquatic (e.g., brackish or aquaculture) and terrestrial environments. We show that random forest models can be trained to differentiate between groupings of environmental factors as well as aspects of study design, but—crucially—also between plastics when compared with control biofilms and between different plastic types and community successional stages. Our meta-analysis confirms that potentially biodegrading Plastisphere members, the hydrocarbonoclastic Oceanospirillales and Alteromonadales are consistently more abundant in plastic than control biofilm samples across multiple studies and environments. This indicates the predilection of these organisms for plastics and confirms the urgent need for their ability to biodegrade plastics to be comprehensively tested. We also identified key knowledge gaps that should be addressed by future studies.Subject terms: Microbial ecology, Soil microbiology, Water microbiology, Microbial ecology, Microbiome     

Understanding the Development and Perception of Global Health for More Effective Student Education

The concept of “global health” that led to the establishment of the World Health Organization in the 1940s is still promoting a global health movement 70 years later. Today’s global health acts first as a guiding principle for our effort to improve people’s health across the globe. Furthermore, global health has become a branch of science, “global health science,” supporting institutionalized education. Lastly, as a discipline, global health should focus on medical and health issues that: 1) are determined primarily by factors with a cross-cultural, cross-national, cross-regional, or global scope; 2) are local but have global significance if not appropriately managed; and 3) can only be efficiently managed through international or global efforts. Therefore, effective global health education must train students 1) to understand global health status; 2) to investigate both global and local health issues with a global perspective; and 3) to devise interventions to deal with these issues.     

Evidence-based policymaking when evidence is incomplete: The case of HIV programme integration

Jan Hontelez and co-authors discuss the use of different types of evidence to inform HIV program integration.

Summary points

• Sustainable Development Goal 3 aims to “ensure healthy lives and promote well-being for all at all ages” and has set a target of achieving global universal health coverage, representing a major policy shift away from mostly disease-specific “vertical programmes”.
• While health service integration can be a promising strategy to improve healthcare coverage, health outcomes, and efficiency, the exact impact of integration in different settings is hard to predict, and policy makers need to choose from a large variety of integration strategies and opportunities with varying levels of scientific evidence.
• Using the case of health service integration for HIV in low- and middle-income countries, we outline implementation strategies for integration opportunities with lacking or scarce high-level causal evidence, based on existing frameworks and methodologies from within and beyond healthcare and implementation science.
• Proper use of scientific evidence in other contexts requires adequate and systematic assessments of the transportability of an intervention. Several methods exist that allow for judging transferability and comprehensively identifying key context-specific indicators across studies that can affect the reported impact of interventions.
• When (transferable) evidence is absent, we propose that by drawing on well-established design and implementation methodologies—underpinned by ongoing learning and iterative improvement of local service delivery strategies—countries could substantially improve decision-making even in the absence of scientific evidence.
• Reaching the goal of making the HIV response an integral part of a larger, universal, people-centred health system that meets the needs and requirements of citizens can be facilitated by applying lessons learned from implementation science and novel design methodologies.

     

Beyond UHC: Monitoring Health and Social Protection Coverage in the Context of Tuberculosis Care and Prevention

Tuberculosis (TB) remains a major global public health problem. In all societies, the disease affects the poorest individuals the worst. A new post-2015 global TB strategy has been developed by WHO, which explicitly highlights the key role of universal health coverage (UHC) and social protection. One of the proposed targets is that “No TB affected families experience catastrophic costs due to TB.” High direct and indirect costs of care hamper access, increase the risk of poor TB treatment outcomes, exacerbate poverty, and contribute to sustaining TB transmission. UHC, conventionally defined as access to health care without risk of financial hardship due to out-of-pocket health care expenditures, is essential but not sufficient for effective and equitable TB care and prevention. Social protection interventions that prevent or mitigate other financial risks associated with TB, including income losses and non-medical expenditures such as on transport and food, are also important. We propose a framework for monitoring both health and social protection coverage, and their impact on TB epidemiology. We describe key indicators and review methodological considerations. We show that while monitoring of general health care access will be important to track the health system environment within which TB services are delivered, specific indicators on TB access, quality, and financial risk protection can also serve as equity-sensitive tracers for progress towards and achievement of overall access and social protection.

This paper is part of the PLOS Universal Health Coverage Collection.

Summary Points

1. The WHO has developed a post-2015 Global TB Strategy emphasizing that significant improvement to TB care and prevention will be impossible without the progressive realization of both universal health coverage and social protection. This paper discusses indicators and measurement approaches for both.
2. While access to high-quality TB diagnosis and treatment has improved dramatically in recent decades, there is still insufficient coverage, especially for correct diagnosis and treatment of multi-drug resistant TB.
3. Continued and expanded monitoring of effective coverage of TB diagnosis and treatment is needed, for which further improvements to existing surveillance systems are required.
4. Many households face severe financial hardship due to TB. Out-of-pocket costs for medical care, transport, and food are often high. However, income loss is the largest financial threat for TB-affected households.
5. Consequently, the financial risk protection target in the post-2015 Global TB Strategy—“No TB affected families experience catastrophic costs due to TB”—concerns all direct costs as well as income loss. This definition is more inclusive than the one conventionally used for “catastrophic health expenditure,” which concerns only direct medical costs.

     

Characterizing Social Media Metrics of Scholarly Papers: The Effect of Document Properties and Collaboration Patterns

A number of new metrics based on social media platforms—grouped under the term “altmetrics”—have recently been introduced as potential indicators of research impact. Despite their current popularity, there is a lack of information regarding the determinants of these metrics. Using publication and citation data from 1.3 million papers published in 2012 and covered in Thomson Reuters’ Web of Science as well as social media counts from Altmetric.com, this paper analyses the main patterns of five social media metrics as a function of document characteristics (i.e., discipline, document type, title length, number of pages and references) and collaborative practices and compares them to patterns known for citations. Results show that the presence of papers on social media is low, with 21.5% of papers receiving at least one tweet, 4.7% being shared on Facebook, 1.9% mentioned on blogs, 0.8% found on Google+ and 0.7% discussed in mainstream media. By contrast, 66.8% of papers have received at least one citation. Our findings show that both citations and social media metrics increase with the extent of collaboration and the length of the references list. On the other hand, while editorials and news items are seldom cited, it is these types of document that are the most popular on Twitter. Similarly, while longer papers typically attract more citations, an opposite trend is seen on social media platforms. Finally, contrary to what is observed for citations, it is papers in the Social Sciences and humanities that are the most often found on social media platforms. On the whole, these findings suggest that factors driving social media and citations are different. Therefore, social media metrics cannot actually be seen as alternatives to citations; at most, they may function as complements to other type of indicators.     

The Grand Convergence: Closing the Divide between Public Health Funding and Global Health Needs

The Global Health 2035 report notes that the “grand convergence”—closure of the infectious, maternal, and child mortality gap between rich and poor countries—is dependent on research and development (R&D) of new drugs, vaccines, diagnostics, and other health tools. However, this convergence (and the R&D underpinning it) will first require an even more fundamental convergence of the different worlds of public health and innovation, where a largely historical gap between global health experts and innovation experts is hindering achievement of the grand convergence in health.The Global Health 2035 report notes that the “grand convergence”—closure of the infectious, maternal, and child mortality gap between rich and poor countries—is dependent on research and development (R&D) of new drugs, vaccines, diagnostics, and other health tools. New tools alone are estimated to deliver a 2% decline each year in the under-5 mortality rate, maternal mortality ratio, and deaths from HIV/AIDS and tuberculosis (TB) [1].However, this convergence (and the R&D underpinning it) is unlikely unless we first have an even more fundamental convergence of the parallel worlds of public health and innovation. At the moment, these worlds are often disconnected, with major gaps to be bridged at both the intellectual and practical levels before we can truly reach a grand convergence in health.     

Improving timeliness in the neglected tropical diseases preventive chemotherapy donation supply chain through information sharing: A retrospective empirical analysis

BackgroundBillions of doses of medicines are donated for mass drug administrations in support of the World Health Organization’s “Roadmap to Implementation,” which aims to control, eliminate, and eradicate Neglected Tropical Diseases (NTDs). The supply chain to deliver these medicines is complex, with fragmented data systems and limited visibility on performance. This study empirically evaluates the impact of an online supply chain performance measurement system, “NTDeliver,” providing understanding of the value of information sharing towards the success of global health programs.MethodsRetrospective secondary data were extracted from NTDeliver, which included 1,484 shipments for four critical medicines ordered by over 100 countries between February 28, 2006 and December 31, 2018. We applied statistical regression models to analyze the impact on key performance metrics, comparing data before and after the system was implemented.FindingsThe results suggest information sharing has a positive association with improvement for two key performance indicators: purchase order timeliness (β = 0.941, p = 0.003) and—most importantly—delivery timeliness (β = 0.828, p = 0.027). There is a positive association with improvement for three variables when the data are publicly shared: shipment timeliness (β = 2.57, p = 0.001), arrival timeliness (β = 2.88, p = 0.003), and delivery timeliness (β = 2.82, p = 0.011).ConclusionsOur findings suggest that information sharing between the NTD program partners via the NTDeliver system has a positive association with supply chain performance improvements, especially when data are shared publicly. Given the large volume of medicine and the significant number of people requiring these medicines, information sharing has the potential to provide improvements to global health programs affecting the health of tens to hundreds of millions of people.     

Latitudinal gradients in biotic niche breadth vary across ecosystem types

Several properties of food webs—the networks of feeding links between species—are known to vary systematically with the species richness of the underlying community. Under the ‘latitude–niche breadth hypothesis’, which predicts that species in the tropics will tend to evolve narrower niches, one might expect that these scaling relationships could also be affected by latitude. To test this hypothesis, we analysed the scaling relationships between species richness and average generality, vulnerability and links per species across a set of 196 empirical food webs. In estuarine, marine and terrestrial food webs there was no effect of latitude on any scaling relationship, suggesting constant niche breadth in these habitats. In freshwater communities, on the other hand, there were strong effects of latitude on scaling relationships, supporting the latitude–niche breadth hypothesis. These contrasting findings indicate that it may be more important to account for habitat than latitude when exploring gradients in food-web structure.     

Assessing and comparing relative farm-level sustainability of smallholder shrimp farms in two Sri Lankan provinces using indices developed from two methodological frameworks

As shrimp farming can be an important means of income generation, particularly among Sri Lanka’s rural communities, it is important that this industry grows in a sustainable manner, starting at the farm level. The objectives of this study were to; 1) create baseline farm-level sustainability indices for smallholder shrimp farms in Sri Lanka using both content-based and system-based frameworks adapted from agriculture; 2) determine whether arranging indicators within both content- and system-based sustainability frameworks would provide additional insight into relative farm sustainability (rather than using just one framework); and 3) seek differences between the North Western Province (NWP) and the Eastern Province (EP) in sustainability index, sub-index, or indicator scores that might be used to create province-specific policies and education programs designed to potentially improve sustainable practices at the farm level. Since little has been published on the development of practical indicators and evaluation of farm-level sustainability in aquaculture, this study adapted two types of frameworks used for measuring sustainability in agriculture: content- and system-based. Using both frameworks, along with expert opinion, indicators of farm level sustainability were developed into a questionnaire and measured on 225 farms in two provinces of Sri Lanka. Indicators primarily included modifiable practices that farmers could influence to improve the chances of their farms’ survival. The farm indicators were normalized using “min-max” normalization, where scores of zero and one were assigned for the least and most sustainable options, respectively. Farm indicators in each province were then aggregated into sub-indices as well an overall aggregated sustainability index score. Similar themes were gleaned from both the content-based and system-based sustainability frameworks, and there was no significant difference between mean overall sustainability scores for the two different frameworks. Farms in the NWP scored significantly higher on the overall sustainability indices of both models despite the NWP’s history of severe disease outbreaks while the EP farms had no disease. Possible reasons for this difference were explored with an in-depth analysis of sub-indices as well as individual indicators. An overall aggregated sustainability index score was a useful baseline measure for monitoring changes in sustainability over time; however, its use was limited when attempting to identify gaps in sustainable management practices and provide practical information for farmers and stakeholders to improve farm-level sustainability. It was important to evaluate individual indicators in addition to sub-indices and overall index scores when making recommendations or identifying gaps in sustainable practices at the farm level.     

Genome Elimination: Translating Basic Research into a Future Tool for Plant Breeding

During the course of our history, humankind has been through different periods of agricultural improvement aimed at enhancing our food supply and the performance of food crops. In recent years, it has become apparent that future crop improvement efforts will require new approaches to address the local challenges of farmers while empowering discovery across industry and academia. New plant breeding approaches are needed to meet this challenge to help feed a growing world population. Here I discuss how a basic research discovery is being translated into a potential future tool for plant breeding, and share the story of researcher Simon Chan, who recognized the potential application of this new approach—genome elimination—for the breeding of staple food crops in Africa and South America.

This article is part of the PLOS Biology Collection “The Promise of Plant Translational Research.”

     

Managing uncertainty: a review of food system scenario analysis and modelling

Complex socio-ecological systems like the food system are unpredictable, especially to long-term horizons such as 2050. In order to manage this uncertainty, scenario analysis has been used in conjunction with food system models to explore plausible future outcomes. Food system scenarios use a diversity of scenario types and modelling approaches determined by the purpose of the exercise and by technical, methodological and epistemological constraints. Our case studies do not suggest Malthusian futures for a projected global population of 9 billion in 2050; but international trade will be a crucial determinant of outcomes; and the concept of sustainability across the dimensions of the food system has been inadequately explored so far. The impact of scenario analysis at a global scale could be strengthened with participatory processes involving key actors at other geographical scales. Food system models are valuable in managing existing knowledge on system behaviour and ensuring the credibility of qualitative stories but they are limited by current datasets for global crop production and trade, land use and hydrology. Climate change is likely to challenge the adaptive capacity of agricultural production and there are important knowledge gaps for modelling research to address.     

Global conservation priorities for marine turtles

Where conservation resources are limited and conservation targets are diverse, robust yet flexible priority-setting frameworks are vital. Priority-setting is especially important for geographically widespread species with distinct populations subject to multiple threats that operate on different spatial and temporal scales. Marine turtles are widely distributed and exhibit intra-specific variations in population sizes and trends, as well as reproduction and morphology. However, current global extinction risk assessment frameworks do not assess conservation status of spatially and biologically distinct marine turtle Regional Management Units (RMUs), and thus do not capture variations in population trends, impacts of threats, or necessary conservation actions across individual populations. To address this issue, we developed a new assessment framework that allowed us to evaluate, compare and organize marine turtle RMUs according to status and threats criteria. Because conservation priorities can vary widely (i.e. from avoiding imminent extinction to maintaining long-term monitoring efforts) we developed a “conservation priorities portfolio” system using categories of paired risk and threats scores for all RMUs (n = 58). We performed these assessments and rankings globally, by species, by ocean basin, and by recognized geopolitical bodies to identify patterns in risk, threats, and data gaps at different scales. This process resulted in characterization of risk and threats to all marine turtle RMUs, including identification of the world''s 11 most endangered marine turtle RMUs based on highest risk and threats scores. This system also highlighted important gaps in available information that is crucial for accurate conservation assessments. Overall, this priority-setting framework can provide guidance for research and conservation priorities at multiple relevant scales, and should serve as a model for conservation status assessments and priority-setting for widespread, long-lived taxa.     

Ancient Protostome Origin of Chemosensory Ionotropic Glutamate Receptors and the Evolution of Insect Taste and Olfaction

Ionotropic glutamate receptors (iGluRs) are a highly conserved family of ligand-gated ion channels present in animals, plants, and bacteria, which are best characterized for their roles in synaptic communication in vertebrate nervous systems. A variant subfamily of iGluRs, the Ionotropic Receptors (IRs), was recently identified as a new class of olfactory receptors in the fruit fly, Drosophila melanogaster, hinting at a broader function of this ion channel family in detection of environmental, as well as intercellular, chemical signals. Here, we investigate the origin and evolution of IRs by comprehensive evolutionary genomics and in situ expression analysis. In marked contrast to the insect-specific Odorant Receptor family, we show that IRs are expressed in olfactory organs across Protostomia—a major branch of the animal kingdom that encompasses arthropods, nematodes, and molluscs—indicating that they represent an ancestral protostome chemosensory receptor family. Two subfamilies of IRs are distinguished: conserved “antennal IRs,” which likely define the first olfactory receptor family of insects, and species-specific “divergent IRs,” which are expressed in peripheral and internal gustatory neurons, implicating this family in taste and food assessment. Comparative analysis of drosophilid IRs reveals the selective forces that have shaped the repertoires in flies with distinct chemosensory preferences. Examination of IR gene structure and genomic distribution suggests both non-allelic homologous recombination and retroposition contributed to the expansion of this multigene family. Together, these findings lay a foundation for functional analysis of these receptors in both neurobiological and evolutionary studies. Furthermore, this work identifies novel targets for manipulating chemosensory-driven behaviours of agricultural pests and disease vectors.     

The Past and Future of Tuberculosis Research

Renewed efforts in tuberculosis (TB) research have led to important new insights into the biology and epidemiology of this devastating disease. Yet, in the face of the modern epidemics of HIV/AIDS, diabetes, and multidrug resistance—all of which contribute to susceptibility to TB—global control of the disease will remain a formidable challenge for years to come. New high-throughput genomics technologies are already contributing to studies of TB''s epidemiology, comparative genomics, evolution, and host–pathogen interaction. We argue here, however, that new multidisciplinary approaches—especially the integration of epidemiology with systems biology in what we call “systems epidemiology”—will be required to eliminate TB.     

Fish Invasions in the World's River Systems: When Natural Processes Are Blurred by Human Activities

Because species invasions are a principal driver of the human-induced biodiversity crisis, the identification of the major determinants of global invasions is a prerequisite for adopting sound conservation policies. Three major hypotheses, which are not necessarily mutually exclusive, have been proposed to explain the establishment of non-native species: the “human activity” hypothesis, which argues that human activities facilitate the establishment of non-native species by disturbing natural landscapes and by increasing propagule pressure; the “biotic resistance” hypothesis, predicting that species-rich communities will readily impede the establishment of non-native species; and the “biotic acceptance” hypothesis, predicting that environmentally suitable habitats for native species are also suitable for non-native species. We tested these hypotheses and report here a global map of fish invasions (i.e., the number of non-native fish species established per river basin) using an original worldwide dataset of freshwater fish occurrences, environmental variables, and human activity indicators for 1,055 river basins covering more than 80% of Earth's surface. First, we identified six major invasion hotspots where non-native species represent more than a quarter of the total number of species. According to the World Conservation Union, these areas are also characterised by the highest proportion of threatened fish species. Second, we show that the human activity indicators account for most of the global variation in non-native species richness, which is highly consistent with the “human activity” hypothesis. In contrast, our results do not provide support for either the “biotic acceptance” or the “biotic resistance” hypothesis. We show that the biogeography of fish invasions matches the geography of human impact at the global scale, which means that natural processes are blurred by human activities in driving fish invasions in the world's river systems. In view of our findings, we fear massive invasions in developing countries with a growing economy as already experienced in developed countries. Anticipating such potential biodiversity threats should therefore be a priority.     

Prevalence and Correlates of HIV Testing among Young People Enrolled in Non-Formal Education Centers in Urban Chiang Mai,Thailand: A Cross-Sectional Study

BackgroundHIV testing is the gateway to HIV prevention, treatment, and care. Despite the established vulnerability of young Thai people to HIV infection, studies examining the prevalence and correlates of HIV testing among the general population of Thai youth are still very limited. This study investigates socio-demographic, behavioral, and psychosocial factors associated with HIV testing among young Thai people enrolled in Non-formal Education Centers (NFEC) in urban Chiang Mai, Northern Thailand.MethodsThis was a cross-sectional quantitative study conducted among young unmarried Thai youth—between the ages of 15 and 24—who were enrolled in NFEC in urban Chiang Mai. Multiple logistic regressions were used to identify correlates of “ever tested for HIV” among the sexually active participants.FindingsOf the 295 sexually active participants, 27.3% reported “ever tested for HIV;” 65.4% “did not consistently use condom;” and 61.7% “had at least 2 lifetime partners.” We found that “self-efficacy” (AOR, 4.92; CI, 1.22–19.73); “perception that it is easy to find a location nearby to test for HIV” (AOR, 4.67; CI, 1.21–18.06); “having at least 2 lifetime sexual partners” (AOR, 2.05; CI, 1.09–3.85); and “ever been pregnant or made someone pregnant” (AOR, 4.06; CI, 2.69–9.15); were associated with increased odds of having ever been tested. On the other hand, “fear of HIV test results” (AOR, 0.21; CI, 0.08–0.57) was associated with lower odds of ever having been tested for HIV.ConclusionThe main finding is that a substantially high proportion of Thai youth is engaged in risky sexual behaviors—yet reports low rates of ever having been tested for HIV. This highlights an urgent need to develop appropriate interventions—based on the identified correlates of HIV testing. There is also an urgent need to enhance HIV testing and to promote safer sexual behaviors among young Thai people—particularly those who are out-of-school.     

Epithelial cell plasticity: breaking boundaries and changing landscapes

Epithelial tissues respond to a wide variety of environmental and genotoxic stresses. As an adaptive mechanism, cells can deviate from their natural paths to acquire new identities, both within and across lineages. Under extreme conditions, epithelial tissues can utilize “shape‐shifting” mechanisms whereby they alter their form and function at a tissue‐wide scale. Mounting evidence suggests that in order to acquire these alternate tissue identities, cells follow a core set of “tissue logic” principles based on developmental paradigms. Here, we review the terminology and the concepts that have been put forward to describe cell plasticity. We also provide insights into various cell intrinsic and extrinsic factors, including genetic mutations, inflammation, microbiota, and therapeutic agents that contribute to cell plasticity. Additionally, we discuss recent studies that have sought to decode the “syntax” of plasticity—i.e., the cellular and molecular principles through which cells acquire new identities in both homeostatic and malignant epithelial tissues—and how these processes can be manipulated for developing novel cancer therapeutics.