884 research outputs found
Economic Impact of Wildlife-Based Tourism in Northern Botswana
Resource /Energy Economics and Policy,
Knowledge, attitudes, and practices related to voluntary counseling and testing (VCT) for HIV among nursing students in Zambia
Access to voluntary counseling and testing (VCT) services has become an important tool in the treatment and prevention of HIV infection. A cross-sectional knowledge, attitudes, and practices (KAP) study was conducted with 50 nursing students in Zambia. All students were aware of where to go for VCT, and 80% had reported using VCT services. However, the participants expressed concerns about privacy and confidentiality related to testing, with most students preferring to seek future VCT at a facility far from their workplace. This ongoing fear of stigma associated with HIV testing was similar to the findings of a recent KAP study conducted among young adults in Bo, Sierra Leone
Cancer Information-Seeking Experiences: The Implications of Hispanic Ethnicity and Spanish Language
BACKGROUND: Strategies to support cancer information-seeking among Hispanics are needed.
METHODS: We analyzed data from the 2005 Health Information National Trends Survey (HINTS) to explore cancer information-seeking experiences among respondents according to ethnicity and language of interview.
RESULTS: Over 80% of Spanish-speaking Hispanics had never looked for cancer information. Compared to English-speaking respondents, Spanish-speaking Hispanics who sought cancer information indicated their search took a lot of effort (67%), was hard to understand (54%), and frustrating (42%). Spanish-speaking Hispanics noted minimal confidence in obtaining cancer information.
CONCLUSIONS: Language and cultural differences must be considered in the design, implementation, and dissemination of cancer information
Microscopic theory for nonequilibrium correlation functions in dense active fluids
One of the key hallmarks of dense active matter in the liquid, supercooled,
and solid phases is so-called equal-time velocity correlations. Crucially,
these correlations can emerge spontaneously, i.e., they require no explicit
alignment interactions, and therefore represent a generic feature of dense
active matter. This indicates that for a meaningful comparison or possible
mapping between active and passive liquids one not only needs to understand
their structural properties, but also the impact of these velocity
correlations. This has already prompted several simulation and theoretical
studies, though they are mostly focused on athermal systems and thus overlook
the effect of translational diffusion. Here we present a fully microscopic
method to calculate nonequilibrium correlations in systems of thermal active
Brownian particles (ABPs). We use the integration through transients (ITT)
formalism together with (active) mode-coupling theory (MCT) and analytically
calculate qualitatively consistent static structure factors and active velocity
correlations. We complement our theoretical results with simulations of both
thermal and athermal ABPs which exemplify the disruptive role that thermal
noise has on velocity correlations
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Control systems for membrane fusion in the ancestral eukaryote; evolution of tethering complexes and SM proteins.
BACKGROUND: In membrane trafficking, the mechanisms ensuring vesicle fusion specificity remain to be fully elucidated. Early models proposed that specificity was encoded entirely by SNARE proteins; more recent models include contributions from Rab proteins, Syntaxin-binding (SM) proteins and tethering factors. Most information on membrane trafficking derives from an evolutionarily narrow sampling of model organisms. However, considering factors from a wider diversity of eukaryotes can provide both functional information on core systems and insight into the evolutionary history of the trafficking machinery. For example, the major Qa/syntaxin SNARE families are present in most eukaryotic genomes and likely each evolved via gene duplication from a single ancestral syntaxin before the existing eukaryotic groups diversified. This pattern is also likely for Rabs and various other components of the membrane trafficking machinery. RESULTS: We performed comparative genomic and phylogenetic analyses, when relevant, on the SM proteins and components of the tethering complexes, both thought to contribute to vesicle fusion specificity. Despite evidence suggestive of secondary losses amongst many lineages, the tethering complexes are well represented across the eukaryotes, suggesting an origin predating the radiation of eukaryotic lineages. Further, whilst we detect distant sequence relations between GARP, COG, exocyst and DSL1 components, these similarities most likely reflect convergent evolution of similar secondary structural elements. No similarity is found between the TRAPP and HOPS complexes and the other tethering factors. Overall, our data favour independent origins for the various tethering complexes. The taxa examined possess at least one homologue of each of the four SM protein families; since the four monophyletic families each encompass a wide diversity of eukaryotes, the SM protein families very likely evolved before the last common eukaryotic ancestor (LCEA). CONCLUSION: These data further support a highly complex LCEA and indicate that the basic architecture of the trafficking system is remarkably conserved and ancient, with the SM proteins and tethering factors having originated very early in eukaryotic evolution. However, the independent origin of the tethering complexes suggests a novel pattern for increasing complexity in the membrane trafficking system, in addition to the pattern of paralogous machinery elaboration seen thus far.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are
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The trypanosome transcriptome is remodelled during differentiation but displays limited responsiveness within life stages.
BACKGROUND: Trypanosomatids utilise polycistronic transcription for production of the vast majority of protein-coding mRNAs, which operates in the absence of gene-specific promoters. Resolution of nascent transcripts by polyadenylation and trans-splicing, together with specific rates of mRNA turnover, serve to generate steady state transcript levels that can differ in abundance across several orders of magnitude and can be developmentally regulated. We used a targeted oligonucleotide microarray, representing the strongly developmentally-regulated T. brucei membrane trafficking system and approximately 10% of the Trypanosoma brucei genome, to investigate both between-stage, or differentiation-dependent, transcriptome changes and within-stage flexibility in response to various challenges. RESULTS: 6% of the gene cohort are developmentally regulated, including several small GTPases, SNAREs, vesicle coat factors and protein kinases both consistent with and extending previous data. Therefore substantial differentiation-dependent remodeling of the trypanosome transcriptome is associated with membrane transport. Both the microarray and qRT-PCR were then used to analyse transcriptome changes resulting from specific gene over-expression, knockdown, altered culture conditions and chemical stress. Firstly, manipulation of Rab5 expression results in co-ordinate changes to clathrin protein expression levels and endocytotic activity, but no detectable changes to steady-state mRNA levels, which indicates that the effect is mediated post-transcriptionally. Secondly, knockdown of clathrin or the variant surface glycoprotein failed to perturb transcription. Thirdly, exposure to dithiothreitol or tunicamycin revealed no evidence for a classical unfolded protein response, mediated in higher eukaryotes by transcriptional changes. Finally, altered serum levels invoked little transcriptome alteration beyond changes to expression of ESAG6/7, the transferrin receptor. CONCLUSION: While trypanosomes regulate mRNA abundance to effect the major changes accompanying differentiation, a given differentiated state appears transcriptionally inflexible. The implications of the absence of a transcriptome response in trypanosomes for both virulence and models of life cycle progression are discussed.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are
Evolution of factors shaping the endoplasmic reticulum
Endomembrane system compartments are significant elements in virtually all eukaryotic cells, supporting functions including protein synthesis, post‐translational modifications and protein/lipid targeting. In terms of membrane area the endoplasmic reticulum (ER) is the largest intracellular organelle, but the origins of proteins defining the organelle and the nature of lineage‐specific modifications remain poorly studied. To understand the evolution of factors mediating ER morphology and function we report a comparative genomics analysis of experimentally characterized ER‐associated proteins involved in maintaining ER structure. We find that reticulons, REEPs, atlastins, Ufe1p, Use1p, Dsl1p, TBC1D20, Yip3p and VAPs are highly conserved, suggesting an origin at least as early as the last eukaryotic common ancestor (LECA), although many of these proteins possess additional non‐ER functions in modern eukaryotes. Secondary losses are common in individual species and in certain lineages, for example lunapark is missing from the Stramenopiles and the Alveolata. Lineage‐specific innovations include protrudin, Caspr1, Arl6IP1, p180, NogoR, kinectin and CLIMP‐63, which are restricted to the Opisthokonta. Hence, much of the machinery required to build and maintain the ER predates the LECA, but alternative strategies for the maintenance and elaboration of ER shape and function are present in modern eukaryotes. Moreover, experimental investigations for ER maintenance factors in diverse eukaryotes are expected to uncover novel mechanisms
Comparison of the Effects of Adenosine, Inosine, and Their Combination as an Adjunct to Reperfusion in the Treatment of Acute Myocardial Infarction
Adenosine and inosine are both key intracellular energy substrates for nucleotide synthesis by salvage pathways, especially during ischemic stress conditions. Additionally they both possess cell protective and cell repair properties. The objective of this study is to detect potential advantages of the combination of adenosine and inosine versus each drug alone, in terms of ventricular function, infarct size reduction and angiogenesis. Myocardial ischemia was created in rodents and treated with adenosine, inosine or their combination. Results of experiments showed that the combination of both drugs significantly reduced infarct size and improved myocardial angiogenesis and ventricular function. The two compounds, while chemically similar, use different intracellular pathways, allowing for complementary biological activities without overlapping. The drug combination at specific 1 : 5 adenosine : inosine dose ratio demonstrated positive cardiologic effects, deserving further evaluation as an adjunct to reperfusion techniques during and after acute coronary syndrome. The association of adenosine and inosine may contribute to reduce myocardial infarction morbidity and mortality rates
Hormonal differences in intimate partner violence perpetrators when they cope with acute stress: A pilot study
Background: Only a few studies have paid attention to the ability of perpetrators of intimate partner violence (IPVAW) against women to cope with acute stress, including hormonal pa-rameters. In fact, previous studies assessed how salivary testosterone (Tsal) and cortisol (Csal) changed after coping with an acute emotional stressor (directly related to IPVAW), and they con-cluded that an imbalance between the two hormones might be characteristic of these men. Never-theless, they neglected to examine the role of other hormones, such as salivary oxytocin (OXsal), which also seemed to play an important role in behavioral regulation, and whether this response could be generalized to other types of stress not directly related to IPVAW. Methods: This study aims to assess whether IPVAW perpetrators (n = 19) present differential hormonal (Tsal, Csal, OXsal and their ratios) and psychological state (anxiety, anger, and general affect) responses when coping with an acute cognitive laboratory stressor (a set of neuropsychological tests performed in front of an expert committee) in comparison with non-violent men (n = 16). This quasi-experimental study also assessed whether the psychological state variables drive this different hormonal response. Re-sults: Our results revealed that IPVAW perpetrators had lower Csal and higher Tsal/Csal ratio levels during the post-task period, as well as higher total levels (average) of OXsal than controls. We also found that, only in IPVAW perpetrators, high levels of baseline anxiety and negative affect were related to high rises in Csal during the stress task. Conclusions: These data present a background showing that IPVAW perpetrators and non-violent men cope differently with stress. These findings might help to identify idiosyncratic profiles of IPVAW perpetrators that can then be employed to establish their therapeutic needs. Moreover, we reinforced the importance of combining biological markers with self-reports, thus increasing the reliability of these forensic assessments. © 2021 by the authors. Licensee MDPI, Basel, Switzerland
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