1,544 research outputs found
Functional Traits Explain Amphibian Distribution in the Brazilian Atlantic Forest
Aim: Species distributions are one of the most important ways to understand how communities interact through macroecological relationships. The functional abilities of a species, such as its plasticity in various environments, can determine its distribution and beta diversity patterns. In this study, we evaluate how functional traits influence the distribution of amphibians, and hypothesize which functional traits explain the current pattern of amphibian species composition in the Atlantic Forest.
Location: Atlantic Forest, Brazil.
Methods: Using potential distributions of Brazilian Atlantic Forest of amphibian species, we analysed the relative importance of abiotic factors and species functional traits in explaining species richness, endemism (with permutation multivariate analysis), and beta diversity components (i.e. total, turnover and nestedness dissimilarities).
Results: Environmental variables explained 59.5% of species richness, whereas functional traits explained 15.8% of species distribution for Anuran and 88.8% for 58 Gymnophiona. Body size had the strongest correlation with the species distribution. Results of nestedness dissimilarities showed that species with medium to large body size, and species that are adapted to living in open areas tended to disperse from west to east direction. Current forest changes directly affected beta diversity patterns (i.e. most species adapted to novel environments increased their ranges). Beta diversity partitioning between humid and dry forests showed decreased nestedness and increased turnover by increasing altitude in the southeastern region of the Atlantic Forest.
Main conclusions: Our study shows that functional traits directly influence the ability of the species to disperse. With the alterations of the natural environment, species more apt to these alterations have dispersed or increased their distribution, which consequently changes community structure. As result, there is nested species distribution patterns and homogenization of amphibian species composition throughout the Brazilian Atlantic Forest
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Predicting Hydrologic Function With Aquatic Gene Fragments
Recent advances in microbiology techniques, such as genetic sequencing, allow for rapid and cost-effective collection of large quantities of genetic information carried within water samples. Here we posit that the unique composition of aquatic DNA material within a water sample contains relevant information about hydrologic function at multiple temporal scales. In this study, machine learning was used to develop discharge prediction models trained on the relative abundance of bacterial taxa classified into operational taxonomic units (OTUs) based on 16S rRNA gene sequences from six large arctic rivers. We term this approach "genohydrology," and show that OTU relative abundances can be used to predict river discharge at monthly and longer timescales. Based on a single DNA sample from each river, the average Nash-Sutcliffe efficiency (NSE) for predicted mean monthly discharge values throughout the year was 0.84, while the NSE for predicted discharge values across different return intervals was 0.67. These are considerable improvements over predictions based only on the area-scaled mean specific discharge of five similar rivers, which had average NSE values of 0.64 and -0.32 for seasonal and recurrence interval discharge values, respectively. The genohydrology approach demonstrates that genetic diversity within the aquatic microbiome is a large and underutilized data resource with benefits for prediction of hydrologic function
Cross-Platform Analysis of HIV-1 RNA Data Generated by a Multicenter Assay Validation Study with Wide Geographic Representation
HIV-1 RNA quantitation continues to be extremely important for monitoring patients infected with HIV-1, and a number of assays have been utilized for this purpose. Differences in assay performance with respect to log10 recovery and HIV-1 subtype specificity have been well documented for commercially available assays, although comparisons are usually limited to one or two assay platforms. Two new FDA-approved assays, the Roche Cobas AmpliPrep/Cobas TaqMan HIV-1 test (RT) and the Abbott RealTime HIV-1 assay (AR), that utilize real-time PCR have replaced previous HIV-1 RNA platforms. Inadequate detection of some strains of HIV-1 resulted in the addition of a new primer/probe set and the introduction of a second version of the RT assay. In this study, comparisons of assay performance between the different FDA-approved HIV-1 RNA assay platforms (both new and existing) were performed by using validation data that included both well-characterized virus stock and locally collected clinical samples. Laboratories across diverse geographical regions performed the validation testing and submitted data to the Virology Quality Assurance program (VQA) for analysis. Correlation values for clinical sample testing varied across the assay platforms (r = 0.832 to 0.986), and average log10 recoveries for HIV-1 RNA controls (compared to the nominal value) ranged from â0.215 to 0.181. These data demonstrate the need for use of one assay platform for longitudinal patient monitoring, but the data also reinforce the notion that no one assay is superior and that testing across platforms may be required for discordance reconciliation
Multimorbidity in bipolar disorder and under-treatment of cardiovascular disease: a cross sectional study
Background: Individuals with serious mental disorders experience poor physical health, especially increased rates of cardiometabolic morbidity and premature morbidity. Recent evidence suggests that individuals with schizophrenia have numerous comorbid physical conditions which may be under-recorded and under-treated but to date very few studies have explored this issue for bipolar disorder.
Methods:We conducted a cross-sectional analysis of a dataset of 1,751,841 registered patients within 314 primary-care practices in Scotland, U.K. Bipolar disorder was identified using Read Codes recorded within electronic medical records. Data on 32 common chronic physical conditions were also assessed. Potential prescribing inequalities were evaluated by analyzing prescribing data for coronary heart disease (CHD) and hypertension.
Results: Compared to controls, individuals with bipolar disorder were significantly less likely to have no recorded physical conditions (OR 0.59, 95% CI 0.54-0.63) and significantly more likely to have one physical condition (OR 1.27, 95% CI 1.16-1.39), two physical conditions (OR 1.45, 95% CI 1.30-1.62) and three or more physical conditions (OR 1.44, 95% CI 1.30-1.64). People with bipolar disorder also had higher rates of thyroid disorders, chronic kidney disease, chronic pain, chronic obstructive airways disease and diabetes but, surprisingly, lower recorded rates of hypertension and atrial fibrillation. People with bipolar disorder and comorbid CHD or hypertension were significantly more likely to be prescribed no antihypertensive or cholesterol-lowering medications compared to controls, and bipolar individuals with CHD or hypertension were significantly less likely to be on 2 or more antihypertensive agents.
Conclusions: Individuals with bipolar disorder are similar to individuals with schizophrenia in having a wide range of comorbid and multiple physical health conditions. They are also less likely than controls to have a primary-care record of cardiovascular conditions such as hypertension and atrial fibrillation. Those with a recorded diagnosis of CHD or hypertension were less likely to be treated with cardiovascular medications and were treated less intensively. This study highlights the high physical healthcare needs of people with bipolar disorder, and provides evidence for a systematic under-recognition and under-treatment of cardiovascular disease in this group
Epidemiology of Coxiella burnetii infection in Africa: a OneHealth systematic review
Background:
Q fever is a common cause of febrile illness and community-acquired pneumonia in resource-limited settings. Coxiella burnetii, the causative pathogen, is transmitted among varied host species, but the epidemiology of the organism in Africa is poorly understood. We conducted a systematic review of C. burnetii epidemiology in Africa from a âOne Healthâ perspective to synthesize the published data and identify knowledge gaps.<p></p>
Methods/Principal Findings:
We searched nine databases to identify articles relevant to four key aspects of C. burnetii epidemiology in human and animal populations in Africa: infection prevalence; disease incidence; transmission risk factors; and infection control efforts. We identified 929 unique articles, 100 of which remained after full-text review. Of these, 41 articles describing 51 studies qualified for data extraction. Animal seroprevalence studies revealed infection by C. burnetii (≤13%) among cattle except for studies in Western and Middle Africa (18â55%). Small ruminant seroprevalence ranged from 11â33%. Human seroprevalence was <8% with the exception of studies among children and in Egypt (10â32%). Close contact with camels and rural residence were associated with increased seropositivity among humans. C. burnetii infection has been associated with livestock abortion. In human cohort studies, Q fever accounted for 2â9% of febrile illness hospitalizations and 1â3% of infective endocarditis cases. We found no studies of disease incidence estimates or disease control efforts.<p></p>
Conclusions/Significance:
C. burnetii infection is detected in humans and in a wide range of animal species across Africa, but seroprevalence varies widely by species and location. Risk factors underlying this variability are poorly understood as is the role of C. burnetii in livestock abortion. Q fever consistently accounts for a notable proportion of undifferentiated human febrile illness and infective endocarditis in cohort studies, but incidence estimates are lacking. C. burnetii presents a real yet underappreciated threat to human and animal health throughout Africa.<p></p>
How do tsetse recognise their hosts? The role of shape in the responses of tsetse (Glossina fuscipes and G. palpalis) to artificial hosts
Palpalis-group tsetse, particularly the subspecies of Glossina palpalis and G. fuscipes, are the most important transmitters of human African trypanomiasis (HAT), transmitting .95% of cases. Traps and insecticide-treated targets are used to control tsetse but more cost-effective baits might be developed through a better understanding of the flyâs host-seeking behaviour.Electrocuting grids were used to assess the numbers of G. palpalis palpalis and G. fuscipes quanzensis attracted to and landing on square or oblong targets of black cloth varying in size from 0.01 m2 to 1.0 m2. For both species, increasing the size of a square target from 0.01 m2 (dimensions = 0.1 x 0.1 m) to 1.0 m2 (1.0 x 1.0 m) increased the catch ,4x however the numbers of tsetse killed per unit area of target declined with target size suggesting that the most cost efficient targets are not the largest. For G. f. quanzensis, horizontal oblongs, (1 m wide x 0.5 m high) caught, 1.8x more tsetse than vertical ones (0.5 m wide x 1.0 m high) but the opposite applied for G. p. palpalis. Shape preference was consistent over the range of target sizes. For G. p. palpalis square targets caught as many tsetse as the oblong; while the evidence is less strong the same
appears to apply to G. f. quanzensis. The results suggest that targets used to control G. p. palpalis and G. f. quanzensis should be square, and that the most cost-effective designs, as judged by the numbers of tsetse caught per area of target, are likely to be in the region of 0.25 x 0.25 m2. The preference of G. p. palpalis for vertical oblongs is unique amongst tsetse species, and it is suggested that this response might be related to its anthropophagic behaviour and hence importance as a vector of HAT
Unionoida (Mollusca: Margaritiferidae, Unionidae) in Arkansas, Third Status Review
We analyzed stream inventories, phylogeographic studies, community and population estimates, life history and reproductive biology research, and suitable habitat investigations conducted from 1997-2008, as well as the Arkansas Natural Heritage Commission mussel database, to update the conservation status for all native freshwater unionoid bivalves thought to occur in Arkansas. Prior to this study, Harris et al. (1997) reviewed the distribution and status of 75 freshwater mussels considered native to Arkansas and ranked 22 species as endangered, threatened or special concern. We now recognize 85 mussel taxa in Arkansas; however, some of those have yet to be described or their nomenclature remains in a state of flux. The previous inclusion of Fusconaia subrotunda (I. Lea 1831) and Obovaria subrotunda (Rafinesque 1820) in the Arkansas native mussel fauna was based on misidentifications. Within the Arkansas mussel fauna, 19 species (22%) are now considered Endangered, 5 species (6%) are ranked as Threatened, 20 species (24%) are of Special Concern, and unfortunately, 1 species has probably been extirpated
Identifying Youth at Clinical High Risk: Whatâs the Emotional Impact?
Background:
Early intervention in major mental illness promises to improve the lives of those identified.
⢠But could identifying youth as at clinical high risk (CHR) for psychosis also do harm given that the majority never develop a psychotic disorder?
⢠Could telling someone they are at risk for psychosis activate internalized stigma that has been associated with increased emotional distress, social withdrawal, non-engagement in treatment, and suicide risk in CHR youth?
⢠Within the context of a larger study of stigma in CHR, we compared emotional responses to the CHR concept assessed before and after clinical feedback by study clinicians.
⢠Some participants had been told of their risk prior to study entry; others had not
Deciphering ocean carbon in a changing world
Author Posting. Š The Author(s), 2016. This is the author's version of the work. It is posted here for personal use, not for redistribution. The definitive version was published in Proceedings of the National Academy of Sciences of the United States of America 113 (2016): 3143-3151, doi:10.1073/pnas.1514645113.Dissolved organic matter (DOM) in the oceans is one of the largest pools of reduced carbon on Earth, comparable in size to the atmospheric CO2 reservoir. A vast number of compounds are present in DOM and they play important roles in all major element cycles, contribute to the storage of atmospheric CO2 in the ocean, support marine ecosystems, and facilitate interactions between organisms. At the heart of the DOM cycle lie molecular-level relationships between the individual compounds in DOM and the members of the ocean microbiome that produce and consume them. In the past, these connections have eluded clear definition because of the sheer numerical complexity of both DOM molecules and microorganisms. Emerging tools in analytical chemistry, microbiology and informatics are breaking down the barriers to a fuller appreciation of these connections. Here we highlight questions being addressed using recent methodological and technological developments in those fields and consider how these advances are transforming our understanding of some of the most important reactions of the marine carbon cycle.Support was provided by National Science Foundation grants OCE1356010, OCE1154320, and OCE1356890, and Gordon and Betty Moore Foundation Grant #3304
Impact of socioeconomic deprivation on rate and cause of death in severe mental illness
Background:
Socioeconomic status has important associations with disease-specific mortality in the general population. Although individuals with Severe Mental Illnesses (SMI) experience significant premature mortality, the relationship between socioeconomic status and mortality in this group remains under investigated.<p></p>
Aims:
To assess the impact of socioeconomic status on rate and cause of death in individuals with SMI (schizophrenia and bipolar disorder) relative to the local (Glasgow) and wider (Scottish) populations.<p></p>
Methods:
Cause and age of death during 2006-2010 inclusive for individuals with schizophrenia or bipolar disorder registered on the Glasgow Psychosis Clinical Information System (PsyCIS) were obtained by linkage to the Scottish General Register Office (GRO). Rate and cause of death by socioeconomic status, measured by Scottish Index of Multiple Deprivation (SIMD), were compared to the Glasgow and Scottish populations.<p></p>
Results:
Death rates were higher in people with SMI across all socioeconomic quintiles compared to the Glasgow and Scottish populations, and persisted when suicide was excluded. Differences were largest in the most deprived quintile (794.6 per 10,000 population vs. 274.7 and 252.4 for Glasgow and Scotland respectively). Cause of death varied by socioeconomic status. For those living in the most deprived quintile, higher drug-related deaths occurred in those with SMI compared to local Glasgow and wider Scottish population rates (12.3% vs. 5.9%, p = <0.001 and 5.1% p = 0.002 respectively). A lower proportion of deaths due to cancer in those with SMI living in the most deprived quintile were also observed, relative to the local Glasgow and wider Scottish populations (12.3% vs. 25.1% p = 0.013 and 26.3% p = <0.001). The proportion of suicides was significantly higher in those with SMI living in the more affluent quintiles relative to Glasgow and Scotland (54.6% vs. 5.8%, p = <0.001 and 5.5%, p = <0.001).
Discussion and conclusions:
Excess mortality in those with SMI occurred across all socioeconomic quintiles compared to the Glasgow and Scottish populations but was most marked in the most deprived quintiles when suicide was excluded as a cause of death. Further work assessing the impact of socioeconomic status on specific causes of premature mortality in SMI is needed
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