Prevalence, transmission and intensity of infection by a microsporidian sex ratio distorter in natural Gammarus duebeni populations

This is a report of the prevalence, transmission and intensity of infection of a microsporidian sex ratio distorter in natural populations of its crustacean host Gammarus duebeni. Prevalence in the adult host population reflects differences in the intensity of infection in transovarially infected embryos and in adult gonadal tissue. The efficiency of transovarial parasite transmission to young also differs between populations, but this alone is insufficient to explain observed patterns of prevalence. Infection intensity may be important in determining future infection of target tissue in the adult and subsequent transmission to future host generations. We consider patterns of parasite infection in terms of selection on transmission and virulence

The effect of salinity on transovarial transmission of a microsporidian infecting Gammarus duebeni

This is an investigation of the impact of salinity on transovarial transmission and burden of a microsporidian sex ratio distorter in the inter-tidal crustacean Gammarus duebeni. Exposure of parasitized mothers to increased salinity during the gonotrophic cycle caused an increase in parasite burden in the follicle cells and a decrease in burden in the oocytes. It appears that salinity impedes parasite transmission from the follicle cells to the oocytes during host oogenesis. A lower proportion of the young were infected in broods from elevated salinity and, in infected offspring, parasite burden was lower than in control embryos. Parasite replication occurred during embryogenesis. However, the pattern of parasite growth did not differ between salinities, indicating that differences in parasite burden could be attributed to a reduction in the initial parasite burden transmitted to the gamete, rather than to a reduction in parasite replication during host embryogenesis. We discuss our findings with respect to parasite/host dynamics and the ecology of the host

The impact of a vertically transmitted microsporidian, Nosema granulosis on the fitness of its Gammarus duebeni host under stressful environmental conditions

Although purely vertically transmitted parasites are predicted to cause low pathogenicity in their hosts, the effects of such parasites on host fitness under stressful environmental conditions have not previously been assessed. Here, we investigate the effects of Nosema granulosis, a vertically transmitted, microsporidian parasite of the brackish water amphipod Gammarus duebeni, on host growth and survival under conditions of host–host competition and limited food. The parasite had no effect on host survival, but caused a reduction in juvenile growth. Stressful environmental conditions also led to a reduction in G. duebeni growth. However, we found no evidence to support the prediction that parasitized hosts would suffer a greater reduction in fitness than uninfected hosts under adverse environmental conditions. We interpret our results in the context of selection for successful vertical parasite transmission

Infection of Gammarus duebeni populations by two vertically transmitted microsporidia; parasite detection and discrimination by PCR–RFLP

We screened a population of the brackish water crustacean Gammarus duebeni from the Isle of Cumbrae for the presence of vertically transmitted microsporidia. We compared 2 screening techniques; light microscopy and PCR-based detection using generic 16S rDNA microsporidian primers. Fifty percent of females from this population tested positive for vertically transmitted microsporidia. The PCR screen was 100% efficient in comparison with existing LM based screening. In addition, the PCR screen produced bands of 2 sizes suggesting that more than 1 species of microsporidian was present. Sequencing revealed 2 distinct species of vertically transmitted microsporidia; 33% of females were infected with the feminizer Nosema granulosis and 17% were infected with a new species which we provisionally designate Microsporidium sp. On the basis of sequence information, we developed a discriminatory PCR–RFLP test based on MspI and HaeIII digests. This screen allows rapid detection and discrimination of vertically transmitted microsporidia in natural field populations. We applied the PCR–RFLP screen to a second G. duebeni population from the Isle of Man. This population also hosted these 2 parasite species. In total 45% of females harboured N. granulosis and 10% harboured Microsporidium sp. No dual-infected individuals were found in either population. The occurrence of 2 vertically transmitted parasites within a population has implications for our understanding of parasite–host relationships in the field and we discuss factors affecting the dynamics of parasite–parasite competition and coexistence

Determination of clothing microclimate volume

Human heat transfer depends on the amount of ventilation between the skin and the clothing layers, which in turn depends on the microclimate volume (7). This volume is hard to quantify. The traditional method, developed by Crockford et al. (4) and further in Birnbaum and Crockford (1) and Sullivan et al. (10) utilises a vacuum oversuit to evacuate and measure the quantity of air trapped in the microenvironment. This method is cumbersome and an alternative may be found in a model approach or using 3D whole body scans. Lee and Hong (8) endeavoured to ascertain the relationship between the insulation value of the clothing ensemble and the air volume measured by using phase-shifting moiré topography. They determined the microclimate volume between a manikin and a T-shirt. This technique was time efficient and accurate, but it was not reported if this technique could be used on humans and how the results compared to the traditional technique of microclimate volume measurement. A third technique to estimate the microclimate volume assumes that the body is represented by a series of cylinders. The circumference of each segment is measured with and without clothing, allowing the volume of each to be calculated. The method was adopted from Lotens and Havenith (9) and is fast and simple. It is the purpose of this study to compare the reliability and reproducibility of the vacuum suit method, scanning method and cylinder model to determine microclimate volume

Perceived impacts of a pilot agricultural livelihood and microfinance intervention on agricultural practices, food security and nutrition for Kenyans living with HIV

Introduction Agriculture is the primary source of income and household food for >75% of rural Kenyans, including people living with HIV (PLHIV), making agricultural yields an important factor in food security and nutrition. Previous studies have shown the interconnectedness of food insecurity, malnutrition, and poor HIV health by elucidating that having one of these conditions increases the likelihood and severity of having another. However, few studies have explored the linkages between agricultural practices, food security and nutrition for PLHIV, or how agricultural livelihood interventions may affect these domains. This study aimed to examine the mechanisms through which an agricultural livelihood intervention can positively or negatively affect agricultural practices, food security, and nutrition for PLHIV. Methods From July 2012-August 2013, we interviewed participants with HIV on antiretroviral therapy (ART) enrolled in a pilot randomized controlled trial (RCT) of an agricultural livelihood and finance intervention to understand the mechanisms through which the intervention may have affected HIV health outcomes. The intervention included agricultural and finance training and a microfinance loan to purchase the MoneyMaker hip pump, a human-powered water pump, seeds, and other farming implements. A purposive sample of 45 intervention and a random subset of 9 control participants were interviewed at 12-month endline visit with a subset of 31 intervention participants interviewed longitudinally at both the 3- and 12-month visits. Transcripts were double coded using an inductive-deductive approach and analyzed for impacts of the intervention on agricultural practices, food security, and nutrition using analytic reports for each key theme. Results All intervention participants described improvements in agricultural practices and yields attributed to the intervention while many also described improvements in income; these changes in turn contributed to improved HIV health, including suppressed viral loads, and a few people noted improved immunologic parameters. Key mechanisms included the knowledge gained from agricultural training which led to improved yields and access to new markets. The use of the irrigation pump was also identified as an additional, lesser important mechanism. All intervention participants reported sustained improvements in food security and nutrition through increased yields and income from the sale of excess crops used to purchase food, and diversification of fresh fruits and vegetables consumed through agricultural production. This led to self-reported weight gain which was a nutritional mechanism towards improved health. Conclusions Agricultural and finance interventions that improve farming practices could lead to improved health outcomes through the pathways of improved food security, income, and diversified diet. The results from this study helped the team to enhance the intervention prior to implementation of the larger cluster RCT (cRCT). By understanding how agricultural livelihood interventions act upon pathways towards improved health, policy options can be developed and implemented to include components that are needed to achieve sustainable outcomes

Hopf algebras and Markov chains: Two examples and a theory

The operation of squaring (coproduct followed by product) in a combinatorial Hopf algebra is shown to induce a Markov chain in natural bases. Chains constructed in this way include widely studied methods of card shuffling, a natural "rock-breaking" process, and Markov chains on simplicial complexes. Many of these chains can be explictly diagonalized using the primitive elements of the algebra and the combinatorics of the free Lie algebra. For card shuffling, this gives an explicit description of the eigenvectors. For rock-breaking, an explicit description of the quasi-stationary distribution and sharp rates to absorption follow.Comment: 51 pages, 17 figures. (Typographical errors corrected. Further fixes will only appear on the version on Amy Pang's website, the arXiv version will not be updated.

Paleobiology of titanosaurs: reproduction, development, histology, pneumaticity, locomotion and neuroanatomy from the South American fossil record

Fil: García, Rodolfo A.. Instituto de Investigación en Paleobiología y Geología. Museo Provincial Carlos Ameghino. Cipolletti; ArgentinaFil: Salgado, Leonardo. Instituto de Investigación en Paleobiología y Geología. General Roca. Río Negro; ArgentinaFil: Fernández, Mariela. Inibioma-Centro Regional Universitario Bariloche. Bariloche. Río Negro; ArgentinaFil: Cerda, Ignacio A.. Instituto de Investigación en Paleobiología y Geología. Museo Provincial Carlos Ameghino. Cipolletti; ArgentinaFil: Carabajal, Ariana Paulina. Museo Carmen Funes. Plaza Huincul. Neuquén; ArgentinaFil: Otero, Alejandro. Museo de La Plata. Universidad Nacional de La Plata; ArgentinaFil: Coria, Rodolfo A.. Instituto de Paleobiología y Geología. Universidad Nacional de Río Negro. Neuquén; ArgentinaFil: Fiorelli, Lucas E.. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica. Anillaco. La Rioja; Argentin

Volume I. Introduction to DUNE

The preponderance of matter over antimatter in the early universe, the dynamics of the supernovae that produced the heavy elements necessary for life, and whether protons eventually decay—these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our universe, its current state, and its eventual fate. The Deep Underground Neutrino Experiment (DUNE) is an international world-class experiment dedicated to addressing these questions as it searches for leptonic charge-parity symmetry violation, stands ready to capture supernova neutrino bursts, and seeks to observe nucleon decay as a signature of a grand unified theory underlying the standard model. The DUNE far detector technical design report (TDR) describes the DUNE physics program and the technical designs of the single- and dual-phase DUNE liquid argon TPC far detector modules. This TDR is intended to justify the technical choices for the far detector that flow down from the high-level physics goals through requirements at all levels of the Project. Volume I contains an executive summary that introduces the DUNE science program, the far detector and the strategy for its modular designs, and the organization and management of the Project. The remainder of Volume I provides more detail on the science program that drives the choice of detector technologies and on the technologies themselves. It also introduces the designs for the DUNE near detector and the DUNE computing model, for which DUNE is planning design reports. Volume II of this TDR describes DUNE\u27s physics program in detail. Volume III describes the technical coordination required for the far detector design, construction, installation, and integration, and its organizational structure. Volume IV describes the single-phase far detector technology. A planned Volume V will describe the dual-phase technology