Perturbations in the gastrointestinal microbiome caused by antibiotics are a major risk factor for Clostridium difficile infection (CDI). Probiotics are often recommended to mitigate CDI symptoms; ...however, there exists only limited evidence showing probiotic efficacy for CDI. Here, we examined changes to the GI microbiota in a study population where probiotic treatment was associated with significantly reduced duration of CDI diarrhea. Subjects being treated with standard of care antibiotics for a primary episode of CDI were randomized to probiotic treatment or placebo for 4 weeks. Probiotic treatment consisted of a daily multi-strain capsule (Lactobacillus acidophilus NCFM, ATCC 700396; Lactobacillus paracasei Lpc-37, ATCC SD5275; Bifidobacterium lactis Bi-07, ATCC SC5220; Bifidobacterium lactis B1-04, ATCC SD5219) containing 1.7 x 1010 CFUs. Stool was collected and analyzed using 16S rRNA sequencing. Microbiome analysis revealed apparent taxonomic differences between treatments and timepoints. Subjects administered probiotics had reduced Verrucomicrobiaceae at week 8 compared to controls. Bacteroides were significantly reduced between weeks 0 to 4 in probiotic treated subjects. Ruminococcus (family Lachnospiraceae), tended to be more abundant at week 8 than week 4 within the placebo group and at week 8 than week 0 within the probiotic group. Similar to these results, previous studies have associated these taxa with probiotic use and with mitigation of CDI symptoms. Compositional prediction of microbial community function revealed that subjects in the placebo group had microbiomes enriched with the iron complex transport system, while probiotic treated subjects had microbiomes enriched with the antibiotic transport system. Results indicate that probiotic use may impact the microbiome function in the face of a CDI; yet, more sensitive methods with higher resolution are warranted to better elucidate the roles associated with these changes. Continuing studies are needed to better understand probiotic effects on microbiome structure and function and the resulting impacts on CDI.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The Global Virome Project Carroll, Dennis; Daszak, Peter; Wolfe, Nathan D ...
Science (American Association for the Advancement of Science),
2018-Feb-23, 2018-02-23, 20180223, Letnik:
359, Številka:
6378
Journal Article
Recenzirano
Expanded viral discovery can improve mitigation
Outbreaks of novel and deadly viruses highlight global vulnerability to emerging
diseases, with many having massive health and economic impacts. Our ...adaptive
toolkit—based largely on vaccines and therapeutics—is often
ineffective because countermeasure development can be outpaced by the speed of
novel viral emergence and spread. Following each outbreak, the public health
community bemoans a lack of prescience, but after decades of reacting to each
event with little focus on mitigation, we remain only marginally better
protected against the next epidemic. Our ability to mitigate disease emergence
is undermined by our poor understanding of the diversity and ecology of viral
threats, and of the drivers of their emergence. We describe a Global Virome
Project (GVP) aimed to launch in 2018 that will help identify the bulk of this
viral threat and provide timely data for public health interventions against
future pandemics.
Systematic review.
To conduct a systematic review of evidence surrounding the effects of exercise on physical fitness in people with spinal cord injury (SCI).
Canada.
The review was limited to ...English-language studies (published prior to March 2010) of people with SCI that evaluated the effects of an exercise intervention on at least one of the four main components of physical fitness (physical capacity, muscular strength, body composition and functional performance). Studies reported at least one of the following outcomes: oxygen uptake/consumption, power output, peak work capacity, muscle strength, body composition, exercise performance or functional performance. A total of 166 studies were identified. After screening, 82 studies (69 chronic SCI; 13 acute SCI) were included in the review. The quality of evidence derived from each study was evaluated using established procedures.
Most studies were of low quality; however, the evidence was consistent that exercise is effective in improving aspects of fitness. There is strong evidence that exercise, performed 2-3 times per week at moderate-to-vigorous intensity, increases physical capacity and muscular strength in the chronic SCI population; the evidence is not strong with respect to the effects of exercise on body composition or functional performance. There were insufficient high-quality studies in the acute SCI population to draw any conclusions.
In the chronic SCI population, there is good evidence that exercise is effective in improving both physical capacity and muscular strength, but insufficient quality evidence to draw meaningful conclusions on its effect on body composition or functional capacity.
To systematically develop evidence-informed physical activity guidelines to improve physical fitness in people with spinal cord injury (SCI).
This study was conducted in Canada.
The Appraisal of ...Guidelines, Research and Evaluation II guideline development protocol was used to develop exercise guidelines to improve physical capacity and muscular strength. The evidence base for the guideline development process consisted of a systematic review and quality appraisal of research examining the effects of exercise on physical fitness among people with SCI. A multidisciplinary expert panel deliberated the evidence and generated the guidelines. Pilot testing led to refinement of the wording and presentation of the guidelines.
The expert panel generated the following guidelines: for important fitness benefits, adults with a SCI should engage in (a) at least 20 min of moderate to vigorous intensity aerobic activity two times per week and (b) strength training exercises two times per week, consisting of three sets of 8-10 repetitions of each exercise for each major muscle group.
People with SCI, clinicians, researchers and fitness programmers are encouraged to adopt these rigorously developed guidelines.
The NASA In Situ Airborne Formaldehyde (ISAF) instrument is a high-performance laser-based detector for gas-phase formaldehyde (HCHO). ISAF uses rotational-state specific laser excitation at 353 nm ...for laser-induced fluorescence (LIF) detection of HCHO. A number of features make ISAF ideal for airborne deployment, including (1) a compact, low-maintenance fiber laser, (2) a single-pass design for stable signal response, (3) a straightforward inlet design, and (4) a stand-alone data acquisition system. A full description of the instrument design is given, along with detailed performance characteristics. The accuracy of reported mixing ratios is ±10% based on calibration against IR and UV absorption of a primary HCHO standard. Precision at 1 Hz is typically better than 20% above 100 pptv, with uncertainty in the signal background contributing most to variability at low mixing ratios. The 1 Hz detection limit for a signal / noise ratio of 2 is 36 pptv for 10 mW of laser power, and the e fold time response at typical sample flow rates is 0.19 s. ISAF has already flown on several field missions and platforms with excellent results.
We review the use of clay models to explore questions about predation rates on small vertebrate taxa that are typically difficult to observe directly. The use of models has a relatively long history ...and we examine the range of taxa studied, which includes squamate reptiles, amphibians, mammals and birds. Within this review, we have also included studies of model eggs, which are used in nest predation studies. We review the questions that have been asked and the interpretations arising from the data. The use of clay model animals has provided us with insights into how differences in prey morphology, size, and colour influence the rate at which they are attacked by predators. This allows us insights into the ecological, behavioural and evolutionary selective pressures of different predators on small vertebrate prey, including analysis of what characteristics predators target and how predators approach their prey (e.g. which part of the body is attacked). Further available interpretations include how regional and habitat variation influences predation events on models. We also briefly discuss the potential for clay models to study interspecific sociality and competition. Finally, we review the problems and limitations with the method and make some suggestions for further studies and amendments to help standardize this creative tool for ecological research.
Observing predation, particularly in small or cryptic animals, can be very difficult. The use of fake prey made from modelling clay, so that one can vary size, colour and shape of the prey, allows us to explore this otherwise hidden relationship between predator and prey. This paper reviews the research on vertebrates using this technique to date. We discuss both the findings and the failings of this technique and make suggestions for further studies.
Global patterns in coronavirus diversity Anthony, Simon J; Johnson, Christine K; Greig, Denise J ...
Virus evolution,
01/2017, Letnik:
3, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Abstract
Since the emergence of Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) and Middle East Respiratory Syndrom Coronavirus (MERS-CoV) it has become increasingly clear that bats are ...important reservoirs of CoVs. Despite this, only 6% of all CoV sequences in GenBank are from bats. The remaining 94% largely consist of known pathogens of public health or agricultural significance, indicating that current research effort is heavily biased towards describing known diseases rather than the ‘pre-emergent’ diversity in bats. Our study addresses this critical gap, and focuses on resource poor countries where the risk of zoonotic emergence is believed to be highest. We surveyed the diversity of CoVs in multiple host taxa from twenty countries to explore the factors driving viral diversity at a global scale. We identified sequences representing 100 discrete phylogenetic clusters, ninety-one of which were found in bats, and used ecological and epidemiologic analyses to show that patterns of CoV diversity correlate with those of bat diversity. This cements bats as the major evolutionary reservoirs and ecological drivers of CoV diversity. Co-phylogenetic reconciliation analysis was also used to show that host switching has contributed to CoV evolution, and a preliminary analysis suggests that regional variation exists in the dynamics of this process. Overall our study represents a model for exploring global viral diversity and advances our fundamental understanding of CoV biodiversity and the potential risk factors associated with zoonotic emergence.
This paper documents the biogeochemistry configuration of the Energy Exascale Earth System Model (E3SM), E3SMv1.1‐BGC. The model simulates historical carbon cycle dynamics, including carbon losses ...predicted in response to land use and land cover change, and the responses of the carbon cycle to changes in climate. In addition, we introduce several innovations in the treatment of soil nutrient limitation mechanisms, including explicit dependence on phosphorus availability. The suite of simulations described here includes E3SM contributions to the Coupled Climate‐Carbon Cycle Model Intercomparison Project and other projects, as well as simulations to explore the impacts of structural uncertainty in representations of nitrogen and phosphorus limitation. We describe the model spin‐up and evaluation procedures, provide an overview of results from the simulation campaign, and highlight key features of the simulations. Cumulative warming over the twentieth century is similar to observations, with a midcentury cold bias offset by stronger warming in recent decades. Ocean biomass production and carbon uptake are underpredicted, likely due to biases in ocean transport leading to widespread anoxia and undersupply of nutrients to surface waters. The inclusion of nutrient limitations in the land biogeochemistry results in weaker carbon fertilization and carbon‐climate feedbacks than exhibited by other Earth System Models that exclude those limitations. Finally, we compare with an alternative representation of terrestrial biogeochemistry, which differs in structure and in initialization of soil phosphorus. While both configurations agree well with observational benchmarks, they differ significantly in their distribution of carbon among different pools and in the strength of nutrient limitations.
Plain Language Summary
A new state‐of‐the‐art Earth System Model has been funded by the United States Department of Energy (DOE) to explore questions relevant to DOE's mission. The Energy Exascale Earth System Model version 1.1 (E3SMv1.1) represents nitrogen and phosphorous controls on the carbon cycle and extends the recently released E3SMv1 to include active biogeochemistry in the land, ocean, and ice components. E3SMv1.1 also includes an alternative representation of terrestrial carbon and nutrient cycles that is used to explore model structural uncertainties. E3SMv1.1's capabilities are demonstrated through a set of experiments described by the Coupled Climate‐Carbon Cycle Model Intercomparison Project, aimed at understanding the influence of changes in climate and CO2 on the carbon cycle. Simulations of the land surface properties and terrestrial carbon cycle compare well with observations, as does the simulated global and regional climate. Nutrient limitations result in less land carbon uptake compared to models that exclude these limitations. However, variations in model structure and initialization influence the magnitude of those limitations and carbon cycle dynamics. The ocean biogeochemistry in E3SMv1.1 simulates less biomass and slightly lower anthropogenic carbon uptake than is observed. Future efforts will aim to reduce model biases as well as to include additional aspects of global carbon cycle dynamics.
Key Points
Introduces the U.S. DOE's Energy Exascale Earth System Model‐Biogeochemistry version, E3SMv1.1‐BGC, is introduced
Ecosystem‐climate responses are characterized in a standard set of C4MIP‐type simulations
The impacts of terrestrial nitrogen and phosphorus limitations and their structural uncertainties are explored
An introductory general chemistry laboratory course was developed to provide an authentic research experience in environmental chemistry. First- and second-year students learned general chemistry ...concepts and laboratory skills in the context of snow chemistry while participating in the course-based undergraduate research experience. Students were guided through all steps of the research process, including research question development, data collection and processing, interpretation of results in the context of scientific literature, and both written and oral presentations. A key component of the course was an individual laboratory experiment in which snow samples from the Arctic were analyzed for pH and ion content. Assessment of the course via pre- and postcourse surveys indicated that students, the majority of whom were women, experienced greater gains in confidence of research skills and general attitudes toward chemistry as compared to the traditional general chemistry laboratory course. This course represents a novel integration of environmental chemistry research into an introductory level chemistry laboratory course, and this approach has significant potential to increase student engagement in the sciences.
A reliable and precise in situ CO2 and CO analysis system has been developed and deployed at eight sites in the NOAA Earth System Research Laboratory's (ESRL) Global Greenhouse Gas Reference Network. ...The network uses very tall (> 300 m) television and radio transmitter towers that provide a convenient platform for mid-boundary-layer trace-gas sampling. Each analyzer has three sample inlets for profile sampling, and a complete vertical profile is obtained every 15 min. The instrument suite at one site has been augmented with a cavity ring-down spectrometer for measuring CO2 and CH4 . The long-term stability of the systems in the field is typically better than 0.1 ppm for CO2 , 6 ppb for CO, and 0.5 ppb for CH4 , as determined from repeated standard gas measurements. The instrumentation is fully automated and includes sensors for measuring a variety of status parameters, such as temperatures, pressures, and flow rates, that are inputs for automated alerts and quality control algorithms. Detailed and time-dependent uncertainty estimates have been constructed for all of the gases, and the uncertainty framework could be readily adapted to other species or analysis systems. The design emphasizes use of off-the-shelf parts and modularity to facilitate network operations and ease of maintenance. The systems report high-quality data with > 93% uptime. Recurrent problems and limitations of the current system are discussed along with general recommendations for high-accuracy trace-gas monitoring. The network is a key component of the North American Carbon Program and a useful model for future research-grade operational greenhouse gas monitoring efforts.
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