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The burden of anthrax in wildlife is demonstrated through high numbers of sudden mortalities among herbivore species, including endangered animal species. East Africa is home of multiple species of faunal wildlife numbering in the millions but there are limited disease surveillance programmes, resulting in a paucity of information on the role of anthrax and other infectious diseases on declining wildlife populations in the region. We reviewed historical data on anthrax outbreaks from Kenya Wildlife Service (KWS) spanning from 1999 to 2017 in Kenya to determine the burden, characteristics and spatial distribution of anthrax outbreaks. A total of 51 anthrax outbreaks associated with 1014 animal deaths were reported across 20 of 60 wildlife conservation areas located in six of the seven agro-ecological zones. Overall, 67% of the outbreaks were reported during the dry seasons, affecting 24 different wildlife species. Over 90% (22 of 24) of the affected species were herbivore, including 12 grazers, five browsers and five mixed grazers and browsers. Buffaloes (23.5%), black rhinos (21.6%) and elephants (17.6%) were the most frequently affected species. Our findings demonstrate the extensive geographic distribution of wildlife anthrax in the country, making it one of the important infectious diseases that threaten wildlife conservation.
We implemented a cross-sectional study in Tana River County, Kenya, a Rift Valley fever (RVF)-endemic area, to quantify the strength of association between RVF virus (RVFv) seroprevalences in livestock and humans, and their respective intra-cluster correlation coefficients (ICCs). The study involved 1932 livestock from 152 households and 552 humans from 170 households. Serum samples were collected and screened for anti-RVFv immunoglobulin G (IgG) antibodies using inhibition IgG enzyme-linked immunosorbent assay (ELISA). Data collected were analysed using generalised linear mixed effects models, with herd/household and village being fitted as random variables. The overall RVFv seroprevalences in livestock and humans were 25.41% (95% confidence interval (CI) 23.49–27.42%) and 21.20% (17.86–24.85%), respectively. The presence of at least one seropositive animal in a household was associated with an increased odds of exposure in people of 2.23 (95% CI 1.03–4.84). The ICCs associated with RVF virus seroprevalence in livestock were 0.30 (95% CI 0.19–0.44) and 0.22 (95% CI 0.12–0.38) within and between herds, respectively. These findings suggest that there is a greater variability of RVF virus exposure between than within herds. We discuss ways of using these ICC estimates in observational surveys for RVF in endemic areas and postulate that the design of the sentinel herd surveillance should consider patterns of RVF clustering to enhance its effectiveness as an early warning system for RVF epidemics.
Oral glucose tolerance and insulin sensitivity are common measures, but are determined using various blood sampling methods, employed under many different experimental conditions. This study established whether measures of oral glucose tolerance and oral glucose-derived insulin sensitivity (insulin sensitivity indices; ISI) differ when calculated from venous v. arterialised blood. Critically, we also established whether any differences between sampling methods are consistent across distinct metabolic conditions (after rest v. after exercise). A total of ten healthy men completed two trials in a randomised order, each consisting of a 120-min oral glucose tolerance test (OGTT), either at rest or post-exercise. Blood was sampled simultaneously from a heated hand (arterialised) and an antecubital vein of the contralateral arm (venous). Under both conditions, glucose time-averaged AUC was greater from arterialised compared with venous plasma but importantly, this difference was larger after rest relative to after exercise (0·99 (sd 0·46) v. 0·56 (sd 0·24) mmol/l, respectively; P<0·01). OGTT-derived ISIMatsuda and ISICederholm were lower when calculated from arterialised relative to venous plasma and the arterialised–venous difference was greater after rest v. after exercise (ISIMatsuda: 1·97 (sd 0·81) v. 1·35 (sd 0·57) arbitrary units (au), respectively; ISICederholm : 14·76 (sd 7·83) v. 8·70 (sd 3·95) au, respectively; both P<0·01). Venous blood provides lower postprandial glucose concentrations and higher estimates of insulin sensitivity, compared with arterialised blood. Most importantly, these differences between blood sampling methods are not consistent after rest v. post-exercise, preventing standardised venous-to-arterialised corrections from being readily applied.
Parasites of the genera Plasmodium and Haemoproteus (Apicomplexa: Haemosporida) are a diverse group of pathogens that infect birds nearly worldwide. Despite their ubiquity, the ecological and evolutionary factors that shape the diversity and distribution of these protozoan parasites among avian communities and geographic regions are poorly understood. Based on a survey throughout the Neotropics of the haemosporidian parasites infecting manakins (Pipridae), a family of Passerine birds endemic to this region, we asked whether host relatedness, ecological similarity and geographic proximity structure parasite turnover between manakin species and local manakin assemblages. We used molecular methods to screen 1343 individuals of 30 manakin species for the presence of parasites. We found no significant correlations between manakin parasite lineage turnover and both manakin species turnover and geographic distance. Climate differences, species turnover in the larger bird community and parasite lineage turnover in non-manakin hosts did not correlate with manakin parasite lineage turnover. We also found no evidence that manakin parasite lineage turnover among host species correlates with range overlap and genetic divergence among hosts. Our analyses indicate that host switching (turnover among host species) and dispersal (turnover among locations) of haemosporidian parasites in manakins are not constrained at this scale.
Correlation of lower Cambrian strata is often confounded by provincialism of key fauna. The widespread occurrence of the micromollusc Watsonella crosbyi Grabau, 1900 is therefore an important biostratigraphic signpost with potential for international correlation of lower Cambrian successions. Previous correlations of W. crosbyi from Australia (Normanville Group) suggested an Atdabanian- to Botoman-equivalent age. However, in the upper part of the Mount Terrible Formation, stratigraphic ranges of W. crosbyi and Aldanella sp. cf. golubevi overlap prior to the incoming of vertically burrowed ‘piperock’, which is indicative of an age no earlier than Cambrian Stage 2. The stratigraphic range of W. crosbyi in the Normanville Group, South Australia correlates with the ranges of the taxon in China, France, Mongolia and Siberia (though not Newfoundland). The new Australian data add further support for considering the first occurrence of W. crosbyi a good potential candidate for defining the base of Cambrian Stage 2. The stratigraphic range of W. crosbyi through the lower Cambrian Normanville Group has been determined based on collections from measured sections. Although rare, W. crosbyi is part of an assemblage of micromolluscs including Bemella sp., Parailsanella sp. cf. murenica and a sinistral form of Aldanella (A. sp. cf. A. golubevi). Other fauna present include Australohalkieria sp., Eremactis mawsoni, chancelloriids and Cupitheca sp.
Mental health research funding priorities in high-income countries must balance longer-term investment in identifying neurobiological mechanisms of disease with shorter-term funding of novel prevention and treatment strategies to alleviate the current burden of mental illness. Prioritising one area of science over others risks reduced returns on the entire scientific portfolio.
This article reviews the most likely mechanisms of transmission of the commonly encountered respiratory viruses (influenza, respiratory syncytial virus, parainfluenza, rhinovirus), herpesviruses, and hepatitis viruses, and presents the guidelines used currently for prevention and control that are in use at Strong Memorial Hospital.
The Helicon-Cathode(HelCat) device is a medium-size linear experiment suitable for a wide range of basic plasma science experiments in areas such as electrostatic turbulence and transport, magnetic relaxation, and high power microwave (HPM)-plasma interactions. The HelCat device is based on dual plasma sources located at opposite ends of the 4 m long vacuum chamber – an RF helicon source at one end and a thermionic cathode at the other. Thirteen coils provide an axial magnetic field B ⩾ 0.220 T that can be configured individually to give various magnetic configurations (e.g. solenoid, mirror, cusp). Additional plasma sources, such as a compact coaxial plasma gun, are also utilized in some experiments, and can be located either along the chamber for perpendicular (to the background magnetic field) plasma injection, or at one of the ends for parallel injection. Using the multiple plasma sources, a wide range of plasma parameters can be obtained. Here, the HelCat device is described in detail and some examples of results from previous and ongoing experiments are given. Additionally, examples of planned experiments and device modifications are also discussed.
A large-scale mass vaccination campaign was carried out in Java, Indonesia in an attempt to control outbreaks of highly pathogenic avian influenza (HPAI) in backyard flocks and commercial smallholder poultry. Sero-monitoring was conducted in mass vaccination and control areas to assess the proportion of the target population with antibodies against HPAI and Newcastle disease (ND). There were four rounds of vaccination, and samples were collected after each round resulting in a total of 27 293 samples. Sampling was performed irrespective of vaccination status. In the mass vaccination areas, 20–45% of poultry sampled had a positive titre to H5 after each round of vaccination, compared to 2–3% in the control group. In the HPAI + ND vaccination group, 12–25% of the population had positive ND titres, compared to 5–13% in the areas without ND vaccination. The level of seropositivity varied by district, age of the bird, and species (ducks vs. chickens).
There are two prominent motivations for why governments seek to promote the electric car: risk management and industrial policy. This article provides operational definitions of these two motivations and uses them to characterize the public policies of six political jurisdictions: California, China, the European Union, France, Germany, and the United States. The article finds that while the European Union is focused primarily on risk management, China, Germany and the United States are primarily engaged in industrial policy. California and France are intermediate cases with a substantial blend of industrial policy and risk management. Future research into the ramifications of industrial policy for liberalized international trade is recommended.
In this chapter, we address the biophysical impacts of climate change, and the consequent impacts on socio-economic systems. Modelling the impacts associated with future climate change provides important information for society’s mitigation and adaptation responses. It also presents significant challenges for Earth system science. We discuss the ways in which uncertainty in impact modelling arises and how it can be managed.
Changes in climate, including those arising as a consequence of anthropogenic perturbations of the climate system, can result in a wide variety of impacts on Earth’s ecosystems and the human activities that depend on them. There are two good practical reasons why it is important to understand the processes involved and assess the possible magnitudes of impacts.
First, an assessment of the extent to which continued anthropogenic climate change could inflict damage is needed in order that well-informed decisions can be made about the reduction of human influences on climate. Our understanding of Earth system behaviour alerts us to the fact that action to mitigate climate change through reductions in greenhouse-gas emissions is not without consequences; so decisions to pursue mitigation options need to be weighed up on the basis of reliable estimates of the costs, risks and benefits of different courses of action.
Secondly, the increase in atmospheric greenhouse-gas concentrations since the Industrial Revolution means that further climate change is inevitable even if greenhouse-gas emissions were to be reduced soon ( Figure 6.1 ). It is therefore necessary for society to adapt to unavoidable changes. Since adaptation action is also not without consequences, it is important that adaptive action addresses credible risks , and represents an efficient allocation of resources.
Databases of accumulated paleoecological and archaeological records provide a means for large-scale syntheses of environmental and cultural histories. We describe the current status of the Canadian Archaeological Radiocarbon Database (CARD), a searchable collection of more than 36,000 14C dates from archaeological and paleontological sites from across North America. CARD, built by the late Dr Richard Morlan of the Canadian Museum of Civilization, consists of uncalibrated 14C data as well as information about the material dated, the cultural association of the date (e.g. Paleoindian, Archaic, Woodland), and its geographic location. The database can be used to study questions relating to prehistoric demography, migrations, human vulnerability to environmental change, and human impact on the landscape, but biases relating to sampling intensity and taphonomy must first be accounted for. Currently, Canada and the northern United States are well represented in the database, while the southern United States is underrepresented. The frequency of 14C dates associated with archaeological sites increases through time from 15,000 cal yr BP until European contact, which likely reflects, among other factors, both the destruction of older cultural carbon due to erosion and dissolution and increasing population numbers through time. An exploratory analysis of the dates reveals their distribution in both time and space, and suggests that the database is sufficiently complete to enable quantitative analysis of general demographic trends.
Women's crisis houses have been developed in the UK as a less stigmatising and less institutional alternative to traditional psychiatric wards.
To examine the effectiveness and cost-effectiveness of women's crisis houses by first examining the feasibility of a pilot patient-preference randomised controlled trial (PP–RCT) design (ISRCTN20804014).
We used a PP–RCT study design to investigate women presenting in crisis needing informal admission. The four study arms were the patient preference arms of women's crisis house or hospital admission, and randomised arms of women's crisis house or hospital admission.
Forty-one women entered the randomised arms of the trial (crisis house n = 19, wards n = 22) and 61 entered the patient-preference arms (crisis house n = 37, ward n = 24). There was no significant difference in outcomes (symptoms, functioning, perceived coercion, stigma, unmet needs or quality of life) or costs for any of the groups (randomised or preference arms), but women who obtained their preferred intervention were more satisfied with treatment.
Although the sample sizes were too small to allow definite conclusions, the results suggest that when services are able to provide interventions preferred by patients, those patients are more likely to be satisfied with treatment. This pilot study provides some evidence that women's crisis houses are as effective as traditional psychiatric wards, and may be more cost-effective.
Nine gnotobiotic piglets, when 8–9 days old, were exposed to an aerosol of strain TR 32 of Mycoplasma hyorhinis and killed at intervals from 14 to 37 days after infection. The aerosol of M. hyorhinis caused bronchopneumonia in 1 pig, pleurisy alone in 2 pigs, pleuropneumonia in 2 pigs and no lung changes in 4 pigs. M. hyorhinis was re-isolated from the lungs of all infected pigs, irrespective of the presence or absence of lesions, though it was only isolated from the serosa and joints when lesions were present. Four control pigs exposed to aerosols of mycoplasma medium had no lesions.
We have studied the low-temperature growth of GaNAs layers on sapphire substrates by plasma-assisted molecular beam epitaxy. We have succeeded in achieving GaN1-xAsx alloys over a large composition range by growing the films at temperature much below the normal GaN growth temperatures with increasing the As2 flux as well as Ga:N flux ratio. We found that the alloys with high As content x>0.1 are amorphous. Optical absorption measurements reveal a continuous gradual decrease of band gap from ˜3.4 eV to ˜1.4 eV with increasing As content. The energy gap reaches its minimum of ˜1.4 eV at the x˜0.6-0.7. For amorphous GaAsN alloys with x<0.3 the composition dependence of the band gap follows the prediction of the band anticrossing model developed for dilute alloys. This suggests that the amorphous GaN1-xAsx alloys have short-range ordering that resembles random crystalline GaN1-xAsx alloys. Such amorphous GaN1-xAsx alloys with tunable electronic structure may be useful as photoanodes in photo-electrochemical cells for hydrogen production.
Bacterial cell biology and pathogenesis
Helen J. Betts, Bacterial Pathogenesis and Genomics Unit, Division of Immunity and Infection, The Institute for Biomedical Research, University of Birmingham, Edgbaston, UK,
Christopher M. Bailey, Bacterial Pathogenesis and Genomics Unit, Division of Immunity and Infection, The Institute for Biomedical Research, University of Birmingham, Edgbaston, UK,
Mark J. Pallen, Bacterial Pathogenesis and Genomics Unit, Division of Immunity and Infection, The Institute for Biomedical Research, University of Birmingham, Edgbaston, UK,
Ian R. Henderson, Bacterial Pathogenesis and Genomics Unit, Division of Immunity and Infection, The Institute for Biomedical Research, University of Birmingham, Edgbaston, UK
To survive in any given niche, bacteria must be capable of sensing, interacting with, and responding to their environment. The method and extent to which bacteria interact with their environment are governed to a large degree by the proteinaceous molecules located on the bacterial cell surface or released into the extracellular milieu. Due to differences in cell-envelope architecture, this process of protein secretion is markedly different between Gram-positive and Gram-negative organisms.
GRAM-POSITIVE VERSUS GRAM-NEGATIVE BACTERIA
Gram-positive bacteria possess a single biological membrane termed the cytoplasmic membrane, which is surrounded by a thick cell wall. The majority of proteins targeted for secretion possess an N-terminal amino-acid signal peptide and utilize the Sec-dependent pathway (Holland, 2004). The Sec machinery is composed of several membrane-associated proteins, including an ATPase (SecA), the Sec translocon (SecYEG), which appears to be the basic unit of cellular life forms, several integral membrane proteins (e.g. SecD, SecF), and a signal peptidase that removes the signal peptide during translocation of the proteins across the cytoplasmic membrane (Dalbey and Chen, 2004). In addition to the Sec pathway, several alternative protein-secretion systems have been recognized in Gram-positive organisms, including the Tat (twin arginine translocation) and ESAT-6/WXG-100 pathways (Pallen, 2002; Robinson and Bolhuis, 2004). However, the role of these systems in protein secretion in Gram-positive bacteria is minor in comparison with the Sec-dependent pathway. Once translocated across the cytoplasmic membrane, the mature protein either can be released into the extracellular milieu or may remain in contact with the cell wall.
Exogenous diseases represent one of the principal agents of culture change associated with the historic period, yet the timing of their initial influence remains undocumented in many regions of North America. Settlement variables, cooking pot volume, and mortality profiles from Oneota tradition occupations are used to investigate the possible occurrence of epidemics in the Upper Mississippi River valley. Synchronous fluctuations in settlement and ceramic variables indicate that following at least two centuries of population growth a significant population decline occurred in the early seventeenth century. Several factors provide support for the role of disease in this decline, including its timing, magnitude, and the documented presence of epidemics in adjacent regions combined with substantial evidence for extensive contact with those areas. This event, prior to direct, sustained contact, is associated with the increased intensity of intergroup exchange occurring with the fur trade. The ability to identify the occurrence of such epidemics is essential for understanding protohistoric cultural dynamics as well as the transmission of disease on a continental level.
Scanning electron microscopy (SEM) for imaging the interface between carbon nanofibers (CNFs) and the underlying substrate is presented. By irradiating the electron beam perpendicular to the substrate, bright contrast is observed at the region where a small gap exists between the CNF and substrate. The energy-diameter diagram for the observation of the bright contrast is derived, which can be understood by using the theory of electron penetration into solid. Monte Carlo simulation is performed to reproduce the experimental observation based on our model, and the contrast sensitivity to the gap height is discussed.