Host species composition influences infection severity among amphibians in the absence of spillover transmission

Wildlife epidemiological outcomes can depend strongly on the composition of an ecological community, particularly when multiple host species are affected by the same pathogen. However, the relationship between host species richness and disease risk can vary with community context and with the degree of spillover transmission that occurs among co‐occurring host species. We examined the degree to which host species composition influences infection by Batrachochytrium dendrobatidis (Bd), a widespread fungal pathogen associated with amphibian population declines around the world, and whether transmission occurs from one highly susceptible host species to other co‐occurring host species. By manipulating larval assemblages of three sympatric amphibian species in the laboratory, we characterized the relationship between host species richness and infection severity, whether infection mediates growth and survivorship differently across various combinations of host species, and whether Bd is transmitted from experimentally inoculated tadpoles to uninfected tadpoles. We found evidence of a dilution effect where Bd infection severity was dramatically reduced in the most susceptible of the three host species (Anaxyrus boreas). Infection also mediated survival and growth of all three host species such that the presence of multiple host species had both positive (e.g., infection reduction) and negative (e.g., mortality) effects on focal species. However, we found no evidence that Bd infection is transmitted by this species. While these results demonstrate that host species richness as well as species identity underpin infection dynamics in this system, dilution is not the product of reduced transmission via fewer infectious individuals of a susceptible host species. We discuss various mechanisms, including encounter reduction and antagonistic interactions such as competition and opportunistic cannibalism that may act in concert to mediate patterns of infection severity, growth, and mortality observed in multihost communities.There are many ways in which infection can be influenced by species diversity. Here we show experimentally that the interactions between species in a multi‐host amphibian community drive the severity of infection by the amphibian chytrid fungus. We find no evidence that infection is transmitted between two host species in our study, suggesting that spillover infection is not a cause of dilution effects in this system.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111214/1/ece31385.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/111214/2/ece31385-sup-0001-FigureS1.pd

Surrogate Parenthood: Protected and Informative Graphs

Many applications, including provenance and some analyses of social networks, require path-based queries over graph-structured data. When these graphs contain sensitive information, paths may be broken, resulting in uninformative query results. This paper presents innovative techniques that give users more informative graph query results; the techniques leverage a common industry practice of providing what we call surrogates: alternate, less sensitive versions of nodes and edges releasable to a broader community. We describe techniques for interposing surrogate nodes and edges to protect sensitive graph components, while maximizing graph connectivity and giving users as much information as possible. In this work, we formalize the problem of creating a protected account G' of a graph G. We provide a utility measure to compare the informativeness of alternate protected accounts and an opacity measure for protected accounts, which indicates the likelihood that an attacker can recreate the topology of the original graph from the protected account. We provide an algorithm to create a maximally useful protected account of a sensitive graph, and show through evaluation with the PLUS prototype that using surrogates and protected accounts adds value for the user, with no significant impact on the time required to generate results for graph queries.Comment: VLDB201

Ultraviolet Radiation Influences Perch Selection by a Neotropical Poison-Dart Frog

Ambient ultraviolet-B radiation can harm amphibian eggs, larvae and adults. However, some amphibians avoid UV-B radiation when given the opportunity. The strawberry poison dart frog, Oophaga pumilio, is diurnal and males vocalize throughout the day in light gaps under forest canopies that expose them to solar radiation. Previous studies have demonstrated that males calling from high perches are more successful at mating than those at lower perches. We investigated whether frogs at higher perches receive more ultraviolet-B than those calling from lower perches. We also investigated whether frogs on perches receiving relatively low ultraviolet-B levels maintained their positions for longer compared to individuals calling from perches receiving higher levels of ultraviolet-B. Finally, since it has been hypothesized that some animals utilize levels of UV-A as a visual cue to avoid UV-B damage, we artificially elevated ultraviolet-A levels to examine whether males exposed to artificially elevated ultraviolet-A abandoned their perches sooner compared to males exposed to visible light. We found that frogs called from perches receiving low ultraviolet-B regardless of perch height, and that frogs maintain their positions longer on perches receiving low ultraviolet-B compared to perches receiving even slightly higher ultraviolet-B levels. Exposing the frogs to artificially elevated levels of ultraviolet-A radiation caused males to move off of their perches faster than when they were exposed to a control light source. These experiments suggest that ultraviolet radiation plays an important role in frog behavior related to perch selection, even in rainforests where much of the solar radiation is shielded by the forest canopy

Sexual assault, sexual abuse, and harassment: Understanding the mental health impact and providing care for survivors: An International Society for Traumatic Stress Studies Briefing Paper

Recent events including revelations of the systematic cover-up of widespread childhood sexual abuse in the Catholic Church, sexual assault and harassment accusations involving many prominent individuals in the entertainment and other industries in the U.S., Canada, Europe, Australia, and Japan, global coverage of cases of violent rape and rape-murder of girls and young women in India, and the #metoo movement, have served to increase public consciousness internationally regarding the pervasiveness of various forms of sexual victimization worldwide. In response, the International Society for Traumatic Stress Studies (ISTSS) commissioned this briefing paper to inform its membership, policymakers, and global stakeholders about the prevalence, impact, and barriers faced by survivors of various forms of sexual victimization including attempted and completed rape, sexual abuse in childhood, and sexual harassment in workplace and educational settings. This paper outlines the research evidence regarding (1) the prevalence of different forms of sexual victimization worldwide including childhood sexual abuse, various forms of sexual assault in adulthood, and sexual harassment in workplace and educational settings, (2) the prevalence of various forms of sexual victimization among several marginalized groups, (3) the psychological, behavioral, and physical health impacts of sexual victimization in childhood and adulthood, (4) evidence-based interventions for survivors of sexual victimization, and (5) barriers to treatment seeking commonly faced by survivors of different forms of sexual victimization. Recommendations are also made in the areas of policy, practice, research, and for professional organizations. Research conducted throughout the world continues to document the alarmingly high prevalence of various forms of sexual victimization throughout the lifespan, including the sexual abuse of children, sexual assault of adults, and sexual harassment within individuals’ place of employment and in educational settings. Although all individuals are vulnerable to experiences of sexual victimization, sexual assault, abuse, and harassment are gendered crimes, such that women and girls are more likely to be victims of these forms of sexual violence. In addition, members of a number of marginalized groups face substantially increased vulnerability to sexual victimization. These include individuals with disabilities, sexual and gender minorities, homeless individuals, individuals engaging in various kinds of sex work, and members of indigenous populations. Further, the impact of sexual victimization is both broad and targeted, with various forms of sexual victimization, including experiences of childhood sexual abuse and sexual assault in adulthood, associated with a host of negative outcomes including the development of posttraumatic stress disorder, depression, anxiety, substance use disorders, eating disordered pathology, suicidality, dissociation, and high risk sexual behaviors. Further, sexual victimization is associated with risk for a number of negative physical health outcomes including obesity, gastrointestinal disorders, chronic pelvic pain, and reproductive health issues. There exists a robust evidence base supporting the efficacy of psychological treatment for PTSD symptomology among adult survivors of childhood sexual abuse and sexual assault. Of extant treatments, cognitive-behavioral based treatments have the strongest evidence for their efficacy. Similarly, cognitive-behavioral treatments, such as trauma-focused CBT, have demonstrated efficacy in treating PTSD and depressive symptomology among children and adolescents who have experienced sexual abuse. There is also some evidence supporting the efficacy of psychopharmacological treatment in reducing PTSD symptomology among adult survivors of sexual abuse or assault. Conversely, there is far more limited research examining the efficacy of psychological treatments for PTSD in other cultural contexts, with the vast majority of research involving United States samples. There is also much less evidence regarding the impact of trauma-focused treatments on other outcomes besides PTSD symptomology and depression, or examining how to treat additional behavioral and mental health issues among survivors of sexual victimization. Finally, almost no research has evaluated the efficacy of psychological treatments for individuals who have experienced sexual harassment in their workplace. Further, research documents that survivors of various forms of sexual victimization often face substantial barriers to disclosing their experience or seeking formal help. These barriers include issues related to defining the experience as a victimization, concerns about not being believed or taken seriously, and feelings of stigma, shame, or embarrassment. Other barriers include concerns about whether the experience will be reported to authorities, mistrust of formal support systems, and prior negative experiences following disclosure of a sexual victimization experience. Many survivors also may be unaware of services that are available to them, may believe that available services are not appropriate for them, and may also face substantial barriers to accessing the care that is available, and available care may be inadequate for addressing their needs in many parts of the world. Finally, it is important to note that many individuals who experience sexual victimization face ongoing issues related to poverty, socioeconomic disadvantage, ongoing personal and community violence, and belong to marginalized groups. Given the prevalence, impact, and substantial barriers to care faced by individuals who experience sexual victimization, including childhood sexual abuse, sexual assault, and sexual harassment, it is clear that concerted, international, and collaborative efforts involving policymakers, researchers, clinicians, professional organizations, and other global stakeholders is imperative

Effects of an Infectious Fungus, Batrachochytrium dendrobatidis, on Amphibian Predator-Prey Interactions

The effects of parasites and pathogens on host behaviors may be particularly important in predator-prey contexts, since few animal behaviors are more crucial for ensuring immediate survival than the avoidance of lethal predators in nature. We examined the effects of an emerging fungal pathogen of amphibians, Batrachochytrium dendrobatidis, on anti-predator behaviors of tadpoles of four frog species. We also investigated whether amphibian predators consumed infected prey, and whether B. dendrobatidis caused differences in predation rates among prey in laboratory feeding trials. We found differences in anti-predator behaviors among larvae of four amphibian species, and show that infected tadpoles of one species (Anaxyrus boreas) were more active and sought refuge more frequently when exposed to predator chemical cues. Salamander predators consumed infected and uninfected tadpoles of three other prey species at similar rates in feeding trials, and predation risk among prey was unaffected by B. dendrobatidis. Collectively, our results show that even sub-lethal exposure to B. dendrobatidis can alter fundamental anti-predator behaviors in some amphibian prey species, and suggest the unexplored possibility that indiscriminate predation between infected and uninfected prey (i.e., non-selective predation) could increase the prevalence of this widely distributed pathogen in amphibian populations. Because one of the most prominent types of predators in many amphibian systems is salamanders, and because salamanders are susceptible to B. dendrobatidis, our work suggests the importance of considering host susceptibility and behavioral changes that could arise from infection in both predators and prey

Effects of Anacetrapib in Patients with Atherosclerotic Vascular Disease

BACKGROUND: Patients with atherosclerotic vascular disease remain at high risk for cardiovascular events despite effective statin-based treatment of low-density lipoprotein (LDL) cholesterol levels. The inhibition of cholesteryl ester transfer protein (CETP) by anacetrapib reduces LDL cholesterol levels and increases high-density lipoprotein (HDL) cholesterol levels. However, trials of other CETP inhibitors have shown neutral or adverse effects on cardiovascular outcomes. METHODS: We conducted a randomized, double-blind, placebo-controlled trial involving 30,449 adults with atherosclerotic vascular disease who were receiving intensive atorvastatin therapy and who had a mean LDL cholesterol level of 61 mg per deciliter (1.58 mmol per liter), a mean non-HDL cholesterol level of 92 mg per deciliter (2.38 mmol per liter), and a mean HDL cholesterol level of 40 mg per deciliter (1.03 mmol per liter). The patients were assigned to receive either 100 mg of anacetrapib once daily (15,225 patients) or matching placebo (15,224 patients). The primary outcome was the first major coronary event, a composite of coronary death, myocardial infarction, or coronary revascularization. RESULTS: During the median follow-up period of 4.1 years, the primary outcome occurred in significantly fewer patients in the anacetrapib group than in the placebo group (1640 of 15,225 patients [10.8%] vs. 1803 of 15,224 patients [11.8%]; rate ratio, 0.91; 95% confidence interval, 0.85 to 0.97; P=0.004). The relative difference in risk was similar across multiple prespecified subgroups. At the trial midpoint, the mean level of HDL cholesterol was higher by 43 mg per deciliter (1.12 mmol per liter) in the anacetrapib group than in the placebo group (a relative difference of 104%), and the mean level of non-HDL cholesterol was lower by 17 mg per deciliter (0.44 mmol per liter), a relative difference of -18%. There were no significant between-group differences in the risk of death, cancer, or other serious adverse events. CONCLUSIONS: Among patients with atherosclerotic vascular disease who were receiving intensive statin therapy, the use of anacetrapib resulted in a lower incidence of major coronary events than the use of placebo. (Funded by Merck and others; Current Controlled Trials number, ISRCTN48678192 ; ClinicalTrials.gov number, NCT01252953 ; and EudraCT number, 2010-023467-18 .)

Correctness Conditions for Highly Available Replicated Databases

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Provenance-based Belief

Provenance has been touted as a basis to establish trust in data. Intuitively, belief in a hypothesis should depend on how much one trusts the relevant data. However, current proposals to assess trust based solely on provenance are insufficient for rigourous decision making. We describe a model of provenance and belief that is necessary and sufficient to incorporate “trust in the data ” in a way that supports normative inference. The model is based on the observation that provenance can be viewed as a causal structure which can be used to compute belief from assessments of the accuracy of sources and transformations that produced relevant data. In our model, data sources are like sensors with associated conditional probability tables. Provenance identifies dependencies among sensors. Together, this information allows construction of causal networks that can be used to compute the belief in a state of the world based on observation of data. This model formalizes the role of source accuracy, and provides a method for formally assessing belief that uses only information in the provenance store, not the contents of the data. 1