1,747 research outputs found
Specificity Between Lactobacilli And Hymenopteran Hosts Is The Exception Rather Than The Rule
Lactobacilli (Lactobacillales: Lactobacillaceae) are well known for their roles in food fermentation, as probiotics, and in human health, but they can also be dominant members of the microbiota of some species of Hymenoptera (ants, bees, and wasps). Honey bees and bumble bees associate with host-specific lactobacilli, and some evidence suggests that these lactobacilli are important for bee health. Social transmission helps maintain associations between these bees and their respective microbiota. To determine whether lactobacilli associated with social hymenopteran hosts are generally host specific, we gathered publicly available Lactobacillus 16S rRNA gene sequences, along with Lactobacillus sequences from 454 pyrosequencing surveys of six other hymenopteran species (three sweat bees and three ants). We determined the comparative secondary structural models of 16S rRNA, which allowed us to accurately align the entire 16S rRNA gene, including fast-evolving regions. BLAST searches and maximum-likelihood phylogenetic reconstructions confirmed that honey and bumble bees have host-specific Lactobacillus associates. Regardless of colony size or within-colony oral sharing of food (trophallaxis), sweat bees and ants associate with lactobacilli that are closely related to those found in vertebrate hosts or in diverse environments. Why honey and bumble bees associate with host-specific lactobacilli while other social Hymenoptera do not remains an open question. Lactobacilli are known to inhibit the growth of other microbes and can be beneficial whether they are coevolved with their host or are recruited by the host from environmental sources through mechanisms of partner choice.National Science Foundation PRFB-1003133, DEB-0919519Texas Higher Education Coordinating Board 01923, National Institutes of Health GM067317Integrative BiologyCellular and Molecular BiologyCenter for Computational Biology and BioinformaticsBrackenridge Field Laborator
Human epicardial adipose tissue expresses a pathogenic profile of adipocytokines in patients with cardiovascular disease
Introduction: Inflammation contributes to cardiovascular disease and is exacerbated with
increased adiposity, particularly omental adiposity; however, the role of epicardial fat is poorly
understood.
Methods: For these studies the expression of inflammatory markers was assessed in epicardial fat
biopsies from coronary artery bypass grafting (CABG) patients using quantitative RT-PCR. Further,
the effects of chronic medications, including statins, as well as peri-operative glucose, insulin and
potassium infusion, on gene expression were also assessed. Circulating resistin, CRP, adiponectin
and leptin levels were determined to assess inflammation.
Results: The expression of adiponectin, resistin and other adipocytokine mRNAs were
comparable to that in omental fat. Epicardial CD45 expression was significantly higher than control
depots (p < 0.01) indicating significant infiltration of macrophages. Statin treated patients showed
significantly lower epicardial expression of IL-6 mRNA, in comparison with the control abdominal
depots (p < 0.001). The serum profile of CABG patients showed significantly higher levels of both
CRP (control: 1.28 ± 1.57 μg/mL vs CABG: 9.11 ± 15.7 μg/mL; p < 0.001) and resistin (control:
10.53 ± 0.81 ng/mL vs CABG: 16.8 ± 1.69 ng/mL; p < 0.01) and significantly lower levels of
adiponectin (control: 29.1 ± 14.8 μg/mL vs CABG: 11.9 ± 6.0 μg/mL; p < 0.05) when compared to
BMI matched controls.
Conclusion: Epicardial and omental fat exhibit a broadly comparable pathogenic mRNA profile,
this may arise in part from macrophage infiltration into the epicardial fat. This study highlights that
chronic inflammation occurs locally as well as systemically potentially contributing further to the
pathogenesis of coronary artery disease
Willingness to participate in a randomized trial comparing catheters to fistulas for vascular access in incident hemodialysis patients: an international survey of nephrologists
BACKGROUND: Current guidelines favor fistulas over catheters as vascular access. Yet, the observational literature comparing fistulas to catheters has important limitations and biases that may be difficult to overcome in the absence of randomization. However, it is not clear if physicians would be willing to participate in a clinical trial comparing fistulas to catheters.
OBJECTIVES: We also sought to elicit participants' opinions on willingness to participate in a future trial regarding catheters and fistulas.
DESIGN: We created a three-part survey consisting of 19 questions. We collected demographic information, respondents' knowledge of the vascular access literature, appropriateness of current guideline recommendations, and their willingness to participate in a future trial.
SETTING: Participants were recruited from Canada, Europe, Australia, and New Zealand.
PARTICIPANTS: Participants include physicians and trainees who are involved in the care of end-stage renal disease patients requiring vascular access.
MEASUREMENTS: Descriptive statistics were used to describe baseline characteristics of respondents according to geographic location. We used logistic regression to model willingness to participate in a future trial.
METHODS: We surveyed nephrologists from Canada, Europe, Australia, and New Zealand to assess their willingness to participate in a randomized trial comparing fistulas to catheters in incident hemodialysis patients.
RESULTS: Our results show that in Canada, 86 % of respondents were willing to participate in a trial (32 % in all patients; 54 % only in patients at high risk of primary failure). In Europe and Australia/New Zealand, the willingness to participate in a trial that included all patients was lower (28 % in Europe; 25 % in Australia/New Zealand), as was a trial that included patients at high risk of primary failure (38 % in Europe; 39 % in Australia/New Zealand). Nephrologists who have been in practice for a few years, saw a larger volume of patients, or self-identified as experts in vascular access literature were more likely to participate in a trial.
LIMITATIONS: Survey distribution was limited to vascular access experts in participating European countries and ultimately led to a discrepancy in numbers of European to non-European respondents overall. Canadian views are likely over-represented in the overall outcomes.
CONCLUSIONS: Our survey results suggest that nephrologists believe there is equipoise surrounding the optimal vascular access strategy and that a randomized controlled study should be undertaken, but restricted to those individuals with a high risk of primary fistula failure
Orbits for the Impatient: A Bayesian Rejection Sampling Method for Quickly Fitting the Orbits of Long-Period Exoplanets
We describe a Bayesian rejection sampling algorithm designed to efficiently
compute posterior distributions of orbital elements for data covering short
fractions of long-period exoplanet orbits. Our implementation of this method,
Orbits for the Impatient (OFTI), converges up to several orders of magnitude
faster than two implementations of MCMC in this regime. We illustrate the
efficiency of our approach by showing that OFTI calculates accurate posteriors
for all existing astrometry of the exoplanet 51 Eri b up to 100 times faster
than a Metropolis-Hastings MCMC. We demonstrate the accuracy of OFTI by
comparing our results for several orbiting systems with those of various MCMC
implementations, finding the output posteriors to be identical within shot
noise. We also describe how our algorithm was used to successfully predict the
location of 51 Eri b six months in the future based on less than three months
of astrometry. Finally, we apply OFTI to ten long-period exoplanets and brown
dwarfs, all but one of which have been monitored over less than 3% of their
orbits, producing fits to their orbits from astrometric records in the
literature.Comment: 32 pages, 28 figures, Accepted to A
Sexual Dimorphic Metabolic and Cognitive Responses of C57BL/6 Mice to Fisetin or Dasatinib and Quercetin Cocktail Oral Treatment.
Senolytic treatment in aged mice clears senescent cell burden leading to functional improvements. However, less is known regarding the effects of these compounds when administered prior to significant senescent cell accumulation. From 4-13 months of age, C57BL/6 male and female mice received monthly oral dosing of either 100 mg/kg Fisetin or a 5 mg/kg Dasatinib (D) plus 50 mg/kg Quercetin (Q) cocktail. During treatment, several aspects of healthy aging were assayed including glucose metabolism using an insulin and glucose tolerance test, cognitive performance using Morris water maze and novel object recognition, and energy metabolism using indirect calorimetry. Afterwards, mice were euthanized for plasma, tissue specific markers of senescence-associated secretory phenotype (SASP), and white adipose tissue accumulation (WAT). Sexually dimorphic treatment effects were observed. Fisetin treated male mice had reduced SASP, enhanced glucose and energy metabolism, improved cognitive performance, and increased mRNA expression of adiponectin receptor 1 and glucose transporter 4. D + Q treatment had minimal effects in male C57BL/6 mice, but was detrimental to females causing increased SASP expression along with accumulation of WAT depots. Reduced energy metabolism and cognitive performance were also noted. Fisetin treatment had no effect in female C57BL/6 mice potentially due to a slower rate of biological aging. In summary, the senolytic treatment in young adulthood, has beneficial, negligible, or detrimental effects in C57BL/6 mice dependent upon sex and treatment. These observations should serve as a note of caution in this rapidly evolving and expanding field of investigation. Male and female C57BL/6 mice were treated with once monthly oral doses of either Dasatinib (D) + Quercetin (Q) or Fisetin from 4-13 months of age. Males treated with Fisetin had reduced SASP markers (blue spheres) as well as improved metabolism (red flame) and cognition. Females treated with D + Q had increased adiposity and SASP markers (red spheres) along with decreased metabolism (blue flame) and cognitive performance. No effects were observed in females treated with Fisetin or males treated with D + Q
Airborne sampling of aerosol particles: Comparison between surface sampling at Christmas Island and P-3 sampling during PEM-Tropics B
Bulk aerosol sampling of soluble ionic compounds from the NASA Wallops Island P-3 aircraft and a tower on Christmas Island during PEM-Tropics B provides an opportunity to assess the magnitude of particle losses in the University of New Hampshire airborne bulk aerosol sampling system. We find that most aerosol-associated ions decrease strongly with height above the sea surface, making direct comparisons between mixing ratios at 30 m on the tower and the lowest flight level of the P-3 (150 m) open to interpretation. Theoretical considerations suggest that vertical gradients of sea-salt aerosol particles should show exponential decreases with height. Observed gradients of Na+ and Mg2+, combining the tower observations with P-3 samples collected below 1 km, are well described by exponential decreases (r values of 0.88 and 0.87, respectively), though the curve fit underestimates average mixing ratios at the surface by 25%. Cascade impactor samples collected on the tower show that \u3e99% of the Na+ and Mg2+mass is on supermicron particles, 65% is in the 1–6 micron range, and just 20% resides on particles with diameters larger than 9 microns. These results indicate that our airborne aerosol sampling probes must be passing particles up to at least 6 microns with high efficiency. We also observed that nss SO42− and NH4+, which are dominantly on accumulation mode particles, tended to decrease between 150 and 1000 m, but they were often considerably higher at the lowest P-3 sampling altitudes than at the tower. This finding is presently not well understood
Mechanical Characterisation of Pneumatically-Spliced Carbon Fibre Yarns as Reinforcements for Polymer Composites
An investigation into the mechanical response of pneumatically-spliced carbon fibre yarns as a potential reinforcing material for polymer composites is presented. High strength mechanical connections between carbon fibre yarns are produced by joining short discontinuous tows into longer lengths via fibre entanglement. The effect of altering the number of high-pressure air pulses fired by a commercially available (Airbond 701H) splicing machine, to form the tow-tow connection, on load bearing capacity and linear stiffness is first evaluated on splices between virgin T700SC-24K-50C carbon fibre tows. The best performing spliced configuration is subsequently utilised in reinforcing unidirectional epoxy laminates, which are mechanically characterised, and their properties compared to those of various continuous fibre and chopped strand mat panels. Results presented in this study demonstrate that pneumatic splicing provides a high strength and sustainable solution for reinforcing polymers with discontinuous (approx. >50 mm in length) virgin, off-cut or waste carbon fibre yarns. It is speculated that with further research, quasi-continuous yarns remanufactured by splicing waste fibres could provide a novel material for weaving, braiding, non-crimp fabrics, or use in 3D printing applications
COVID-19: Time for precision epidemiology
The global COVID-19 (SARS-CoV2, COVID-19) tsunami caused by SARSCoV2 is inundating and often-overwhelming health care systems in most countries and regions..
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