Soil zinc deficiency and child stunting: Evidence from Nepal

We examine the negative child health impacts of soil zinc (Zn) deficiency in Nepal. Soil Zn deficiency limits both crop yields and the Zn concentration in food crops, leading many to speculate that it underlies human Zn deficiency and child stunting, globally and particularly in South Asia. We find strong evidence that soil Zn deficiency does have a causal impact on child stunting in Nepal’s Tarai region, the breadbasket of the country. Using causal bounds, we find that a 1 part per million increase in plant-available soil Zn – achievable with application of Zn-enriched fertilizer – decreases child stunting by between 1 and 7.5 percentage points. Multiple statistical sensitivity tests indicate that this relationship is unlikely to be manufactured by omitted, relevant variables.     

Extending multilevel spatial models to include spatially varying coefficients

Multilevel models have long been used by health geographers working on questions of space, place, and health. Similarly, health geographers have pursued interests in determining whether or not the effect of an exposure on a health outcome varies spatially. However, relatively little work has sought to use multilevel models to explore spatial variability in the effects of a contextual exposure on a health outcome. Methodologically, extending multilevel models to allow intercepts and slopes to vary spatially is straightforward. The purpose of this paper, therefore, is to show how multilevel spatial models can be extended to include spatially varying covariate effects. We provide an empirical example on the effect of agriculture on malaria risk in children under 5 years of age in the Democratic Republic of Congo.     

Embracing nature’s complexity: Immunoparasitology in the wild

A wealth of research is dedicated to understanding how resistance against parasites is conferred and how parasite-driven pathology is regulated. This research is in part driven by the hope to better treatments for parasitic diseases of humans and livestock, and in part by immunologists who use parasitic infections as biomedical tools to evoke physiological immune responses. Much of the current mechanistic knowledge has been discovered in laboratory studies using model organisms, especially the laboratory mouse. However, wildlife are also hosts to a range of parasites. Through the study of host-parasite interactions in these non-laboratory systems we can gain a deeper understanding of parasite immunology in a more natural, complex environment. With a focus on helminth parasites, we here explore the insights gained into parasite-induced immune responses through (for immunologists) non-conventional experimental systems, and how current core findings from laboratory studies are reflected in these more natural conditions. The quality of the immune response is undoubtedly a central player in susceptibility versus resistance, as many laboratory studies have shown. Yet, in the wild, parasite infections tend to be chronic diseases. Whilst reading our review, we encourage the reader to consider the following questions which may (only) be answered by studying naturally occurring parasites in the wild: a) what type of immune responses are mounted against parasites in different hosts in the wild, and how do they vary within an individual over time, between individuals of the same species and between species? b) can we use wild or semi-wild study systems to understand the evolutionary drivers for tolerance versus resistance towards a parasite? c) what determines the ability of the host to cope with an infection and is there a link with the type of immune response mounted? d) can we modulate environmental factors to manipulate a wild animal’s immune response to parasitic infections, with translation potential for humans, wildlife, and livestock? and e) in context of this special issue, what lessons for Type 2 immunity can we glean from studying animals in their natural environments? Further, we aim to integrate some of the knowledge gained in semi-wild and wild settings with knowledge gained from traditional laboratory-based research, and to raise awareness for the opportunities (and challenges) that come with integrating a multitude of naturally-occurring variables into immunoparasitological research.     

La maladie de l’oreille du surfeur : l’imaginaire du soi naturalisé à partir d’une pathologie due à l’immersion en milieu aquatique

GoalsStarting from the example of the exostosis of the external auditory canal, a modification due to the impact of the sea on the body, this article considers how this pathology is experienced and interpreted by those who contract it. After defining “surfer's ear” from an anthropo-medical point of view, we will address the meaning that individuals give to it, such as the belief of becoming fish.MethodologyOver the course of several years of field observation and interviews, mainly on the beaches of the Atlantic Pyrenees, we were able to compare different individuals’ discourses about how the surfing body, immersed in nature, is perceived and experienced.ResultsThis helps to understand thoughts that can link people to the ocean, and more widely to nature, in our contemporary Western society. Thus, penetrating and being penetrated by this living water implies a sensual relationship with the environment, in a search both for erotic pleasure and an enveloping maternal security, lost from birth.DiscussionThis relationship to the environment implements a sensory ecology where the human becomes nature, and nature takes human form. This is an occasion for the reinvention of links, not in an opposition between human and non-human, but by reminding humans that they can find balance in abandoning themselves to nature.ConclusionPathologies of the ear define an imaginary clinic of the body. The body is thus rendered unfit by the physical sensations of marine pathology but, above all, by the belief in a psychic envelopment in water.     

Identifying strains that contribute to complex diseases through the study of microbial inheritance

It has been 35 y since Carl Woese reported in PNAS how sequencing ribosomal RNA genes could be used to distinguish the three domains of life on Earth. During the past decade, 16S rDNA sequencing has enabled the now frequent enumeration of bacterial communities that populate the bodies of humans representing different ages, cultural traditions, and health states. A challenge going forward is to quantify the contributions of community members to wellness, disease risk, and disease pathogenesis. Here, we explore a theoretical framework for studies of the inheritance of bacterial strains and discuss the advantages and disadvantages of various study designs for assessing the contribution of strains to complex diseases.     

Dental Signatures for Exudativory in Living Primates,with Comparisons to Other Gouging Mammals

Exudativory, the consumption of gums, is an obligate or a facultative dietary niche for some primates and marsupials. Exudativory has been cited as a dietary niche that may have been present in early primates, so finding a dental signature for exudativory is highly desirable. The present study combines exudativorous lorisoids (galagos and lorises) into one sample to compare to closely related, non-exudativorous lorisoids to search for a consistent dental signature of exudativory. Linear measurements were taken from the toothcomb, P₂, M₃, upper canine, and P² from skulls of 295 adult galagids and lorisids. Also, differential distribution of enamel on the anterior teeth was qualitatively investigated as a dental signature for gouging (a behavior that facilitates some exudativory) by micro-CT scanning one specimen each from two gougers, Nycticebus coucang and Callithrix jacchus, and two non-gougers, Perodicticus potto, and Saguinus fuscicollis. Non-primate gouging mammals, the vampire bat Desmodus rotundus and the sugar glider Petaurus breviceps, were compared to non-gouging relatives. Statistical analysis revealed that exudativorous galagos and lorises had significantly (P < 0.05) reduced M₃ relative to non-exudativorous galagos and lorises. While the sample sizes for assessing enamel thickness were small, preliminary results show that gouging primates and non-primate mammals have reduced lingual enamel thickness on the anterior dentition compared to non-gouging relatives. We suggest that reduction of mastication, and, therefore, M₃ dimensions are a likely dental signature for exudativory in Primates. While broader samples are needed to statistically confirm, differential distribution of enamel in the anterior dentition may also be a signature of exudativory. Anat Rec, 2019. © 2018 Wiley Periodicals, Inc. Anat Rec, 303:265–281, 2020. © 2018 American Association for Anatomy     

Impacts of biodiversity and biodiversity loss on zoonotic diseases

Zoonotic diseases are infectious diseases of humans caused by pathogens that are shared between humans and other vertebrate animals. Previously, pristine natural areas with high biodiversity were seen as likely sources of new zoonotic pathogens, suggesting that biodiversity could have negative impacts on human health. At the same time, biodiversity has been recognized as potentially benefiting human health by reducing the transmission of some pathogens that have already established themselves in human populations. These apparently opposing effects of biodiversity in human health may now be reconcilable. Recent research demonstrates that some taxa are much more likely to be zoonotic hosts than others are, and that these animals often proliferate in human-dominated landscapes, increasing the likelihood of spillover. In less-disturbed areas, however, these zoonotic reservoir hosts are less abundant and nonreservoirs predominate. Thus, biodiversity loss appears to increase the risk of human exposure to both new and established zoonotic pathogens. This new synthesis of the effects of biodiversity on zoonotic diseases presents an opportunity to articulate the next generation of research questions that can inform management and policy. Future studies should focus on collecting and analyzing data on the diversity, abundance, and capacity to transmit of the taxa that actually share zoonotic pathogens with us. To predict and prevent future epidemics, researchers should also focus on how these metrics change in response to human impacts on the environment, and how human behaviors can mitigate these effects. Restoration of biodiversity is an important frontier in the management of zoonotic disease risk.     

预印本学术交流生态中的参与主体及作用

【目的】 探究预印本学术生态的参与主体,以及参与主体发挥的具体作用,以期为我国预印本学术生态的建设提供借鉴。【方法】 通过生态角色分析的方法,调研并梳理arXiv、bioRxiv和SSRN 3个典型预印本平台的学术交流生态。根据梳理结果对预印本学术交流生态中具体的参与主体以及主体承担的生态角色进行分析,归纳预印本学术交流生态模型,结合该模型对每类主体所发挥的作用作出具体阐述。【结果】 预印本学术交流生态中有5类常见的参与主体和8种生态角色。不同参与主体承担不同的生态角色,并在预印本学术交流生态中发挥不同的作用。【结论】 预印本学术交流是一个由科学界主导的学术交流方式,各类参与主体对预印本学术交流生态建设发挥着重要作用。我国预印本学术交流的发展尚未成熟,各类参与主体需要通过承担各自的角色积极参与预印本学术交流,以推动我国学术信息交流新生态的建设和发展。