922 research outputs found
Fluorescent amplified fragment length polymorphism analysis of Norwegian Bacillus cereus and Bacillus thuringiensis soil isolates
We examined 154 Norwegian B. cereus and B. thuringiensis soil isolates (collected from five different locations), 8 B. cereus and 2 B. thuringiensis reference strains, and 2 Bacillus anthracis strains by using fluorescent amplified fragment length polymorphism (AFLP). We employed a novel fragment identification approach based on a hierarchical agglomerative clustering routine that identifies fragments in an automated fashion. No method is free of error, and we identified the major sources so that experiments can be designed to minimize its effect. Phylogenetic analysis of the fluorescent AFLP results reveals five genetic groups in these group 1 bacilli. The ATCC reference strains were restricted to two of the genetic groups, clearly not representative of the diversity in these bacteria. Both B. anthracis strains analyzed were closely related and affiliated with a B. cereus milk isolate (ATCC 4342) and a B. cereus human pathogenic strain (periodontitis). Across the entire study, pathogenic strains, including B. anthracis, were more closely related to one another than to the environmental isolates. Eight strains representing the five distinct phylogenetic clusters were further analyzed by comparison of their 16S rRNA gene sequences to confirm the phylogenetic status of these groups. This analysis was consistent with the AFLP analysis, although of much lower resolution. The innovation of automated genotype analysis by using a replicated and statistical approach to fragment identification will allow very large sample analyses in the future
A comparative study of WASP-67b and HAT-P-38b from WFC3 data
Atmospheric temperature and planetary gravity are thought to be the main
parameters affecting cloud formation in giant exoplanet atmospheres. Recent
attempts to understand cloud formation have explored wide regions of the
equilibrium temperature-gravity parameter space. In this study, we instead
compare the case of two giant planets with nearly identical equilibrium
temperature ( ) and gravity (. During Cycle 23, we collected WFC3/G141
observations of the two planets, WASP-67 b and HAT-P-38 b. HAT-P-38 b, with
mass 0.42 M and radius 1.4 , exhibits a relatively
clear atmosphere with a clear detection of water. We refine the orbital period
of this planet with new observations, obtaining . WASP-67 b, with mass 0.27 M and radius 0.83
, shows a more muted water absorption feature than that of
HAT-P-38 b, indicating either a higher cloud deck in the atmosphere or a more
metal-rich composition. The difference in the spectra supports the hypothesis
that giant exoplanet atmospheres carry traces of their formation history.
Future observations in the visible and mid-infrared are needed to probe the
aerosol properties and constrain the evolutionary scenario of these planets.Comment: 16 pages, 17 figures, 8 tables, accepted for publication in The
Astronomical Journa
Unexpected patterns of global population structure in melon-headed whales Peponocephala electra
Foraging specialization, environmental barriers, and social structure have driven the development of strong genetic differentiation within many marine species, including most of the large dolphin species commonly referred to as ‘blackfish’ (subfamily Globicephalinae). We used mitochondrial sequence data (mtDNA) and genotypes from 14 nuclear microsatellite loci (nDNA) to examine patterns of genetic population structure in melon-headed whales Peponocephala electra (MHWs), poorly known members of the blackfish family for which genetic structuring is unknown. MHWs are globally distributed in tropical and subtropical waters, and have formed resident populations around oceanic islands. They frequently mass strand, suggesting strong social cohesion within groups. Based on these characteristics, we hypothesized that MHWs would exhibit strong regional genetic differentiation, similar to that observed in other members of the Globicephalinae subfamily. Instead we found only moderate differentiation (median mtDNA ΦST = 0.204, median nDNA FST = 0.012) among populations both within and between ocean basins. Our results suggest that populations of MHWs that are resident to oceanic islands maintain a higher level of genetic connectivity than is seen in most other blackfish. MHWs may be more behaviorally similar to delphinids from the Delphininae subfamily (particularly the spinner dolphin Stenella longirostris), which are known to form coastal and island-associated resident populations that maintain genetic connectivity either through occasional long-distance dispersal or gene flow with larger pelagic populations. Our results suggest that differences in social organization may drive different patterns of population structure in social odontocete
Changes in undergraduate student alcohol consumption as they progress through university
BACKGROUND:
Unhealthy alcohol use amongst university students is a major public health concern. Although previous studies suggest a raised level of consumption amongst the UK student
population there is little consistent information available about the pattern of alcohol consumption as they progress through university. The aim of the current research was to describe drinking patterns of UK full-time undergraduate students as they progress through their degree course.
METHOD:
Data were collected over three years from 5895 undergraduate students who began their studies in either 2000 or 2001. Longitudinal data (i.e. Years 1–3) were available from 225 students. The remaining 5670 students all responded to at least one of the three surveys (Year 1
n = 2843; Year 2 n = 2219; Year 3 n = 1805).
Results: Students reported consuming significantly more units of alcohol per week at Year 1 than at Years 2 or 3 of their degree. Male students reported a higher consumption of units of alcohol than their female peers. When alcohol intake was classified using the Royal College of Physicians
guidelines [1] there was no difference between male and females students in terms of the percentage exceeding recommended limits. Compared to those who were low level consumers students who reported drinking above low levels at Year 1 had at least 10 times the odds of continuing to consume above low levels at year 3. Students who reported higher levels of drinking were more likely to report that alcohol had a negative impact on their studies, finances and physical health. Consistent with the reduction in units over time students reported lower levels of negative
impact during Year 3 when compared to Year 1.
CONCLUSION:
The current findings suggest that student alcohol consumption declines over their undergraduate studies; however weekly levels of consumption at Year 3 remain high for a substantial number of students. The persistence of high levels of consumption in a large population
of students suggests the need for effective preventative and treatment interventions for all year
groups
The Basic Competencies of Biological Experimentation: Concept-Skill Statements
This biological experimentation competencies map is a model created by members of the ACE-Bio Network of seven areas a competent biologist calls in when doing experimentation in biology. Each competency is represented by a summary word on a uniquely colored segment of the model. For presentation convenience, the seven major areas within experimentation in biology are mapped onto tables in a linear manner. However, this is not meant to convey a particular order that one must follow during experimentation. The areas are given equal weight and flexible order of their use throughout the process of experimentation. This work is meant to provide a framework for ACE Bio Network participants and other instructors or academic leaders in the biological sciences to study implementation of experimentation activities and assessments across diverse institutional and curricular contexts. In addition to the document in pdf format, another link provides the file in MSWord format so that users can easily modify it to guide assessment of student learning about experimentation, undergraduate biology instruction, curriculum development, professional faculty development, program evaluation, or review of research literature in a way that is appropriate to their own context
Acute low-volume high-intensity interval exercise and continuous moderate-intensity exercise elicit a similar improvement in 24-h glycemic control in overweight and obese adults
Background: Acute exercise reduces postprandial oxidative stress and glycemia; however, the effects of exercise intensity are unclear. We investigated the effect of acute low-volume high-intensity interval-exercise (LV-HIIE) and continuous moderate-intensity exercise (CMIE) on glycemic control and oxidative stress in overweight and obese, inactive adults.Methods: Twenty-seven adults were randomly allocated to perform a single session of LV-HIIE (9 females, 5 males; age: 30 ± 1 years; BMI: 29 ± 1 kg·m−2; mean ± SEM) or CMIE (8 females, 5 males; age: 30 ± 2.0; BMI: 30 ± 2.0) 1 h after consumption of a standard breakfast. Plasma redox status, glucose and insulin were measured. Continuous glucose monitoring (CGM) was conducted during the 24-h period before (rest day) and after exercise (exercise day).Results: Plasma thiobarbituric acid reactive substances (TBARS; 29 ±13%, p < 0.01; mean percent change ±90% confidence limit), hydrogen peroxide (44 ± 16%, p < 0.01), catalase activity (50 ± 16%, p < 0.01), and superoxide dismutase activity (21 ± 6%, p < 0.01) significantly increased 1 h after breakfast (prior to exercise) compared to baseline. Exercise significantly decreased postprandial glycaemia in whole blood (−6 ± 5%, p < 0.01), irrespective of the exercise protocol. Only CMIE significantly decreased postprandial TBARS (CMIE: −33 ± 8%, p < 0.01; LV-HIIE: 11 ± 22%, p = 0.34) and hydrogen peroxide (CMIE: −25 ± 15%, p = 0.04; LV-HIIE: 7 ± 26%; p = 0.37). Acute exercise provided a similar significant improvement in 24-h average glucose levels (−5 ± 2%, p < 0.01), hyperglycemic excursions (−37 ± 60%, p < 0.01), peak glucose concentrations (−8 ± 4%, p < 0.01), and the 2-h postprandial glucose response to dinner (−9 ± 4%, p < 0.01), irrespective of the exercise protocol.Conclusion: Despite elevated postprandial oxidative stress compared to CMIE, LV-HIIE is an equally effective exercise mode for improving 24-h glycemic control in overweight and obese adults
Update to the study protocol for an implementation-effectiveness trial comparing two education strategies for improving the uptake of noninvasive ventilation in patients with severe COPD exacerbation
BACKGROUND: There is strong evidence that noninvasive ventilation (NIV) improves the outcomes of patients hospitalized with severe COPD exacerbation, and NIV is recommended as the first-line therapy for these patients. Yet, several studies have demonstrated substantial variation in NIV use across hospitals, leading to preventable morbidity and mortality. In addition, prior studies suggested that efforts to increase NIV use in COPD need to account for the complex and interdisciplinary nature of NIV delivery and the need for team coordination. Therefore, our initial project aimed to compare two educational strategies: online education (OLE) and interprofessional education (IPE), which targets complex team-based care in NIV delivery. Due to the impact of the COVID-19 pandemic on recruitment and planned intervention, we had made several changes in the study design, statistical analysis, and implementation strategies delivery as outlined in the methods.
METHODS: We originally proposed a two-arm, pragmatic, cluster, randomized hybrid implementation-effectiveness trial comparing two education strategies to improve NIV uptake in patients with severe COPD exacerbation in 20 hospitals with a low baseline rate of NIV use. Due to logistical constrains and slow recruitment, we changed the study design to an opened cohort stepped-wedge design with three steps which will allow the institutions to enroll when they are ready to participate. Only the IPE strategy will be implemented, and the education will be provided in an online virtual format. Our primary outcome will be the hospital-level risk-standardized NIV proportion for the period post-IPE training, along with the change in rate from the period prior to training. Aim 1 will compare the change over time of NIV use among patients with COPD in the step-wedged design. Aim 2 will explore the mediators\u27 role (respiratory therapist autonomy and team functionality) on the relationship between the implementation strategies and effectiveness. Finally, in Aim 3, through interviews with providers, we will assess the acceptability and feasibility of the educational training.
CONCLUSION: The changes in study design will result in several limitation. Most importantly, the hospitals in the three cohorts are not randomized as they enroll based on their readiness. Second, the delivery of the IPE is virtual, and it is not known if remote education is conducive to team building. However, this study will be among the first to test the impact of IPE in the inpatient setting carefully and may generalize to other interventions directed to seriously ill patients.
TRIAL REGISTRATION: ClinicalTrials.gov NCT04206735 . Registered on December 20, 2019
Fructose reprogrammes glutamine-dependent oxidative metabolism to support LPS-induced inflammation
Combined MYC and P53 defects emerge at medulloblastoma relapse and define rapidly progressive, therapeutically targetable disease
We undertook a comprehensive clinical and biological investigation of serial medulloblastoma biopsies obtained at diagnosis and relapse. CombinedMYCfamily amplifications and P53 pathway defects commonly emerged at relapse, and all patients in this group died of rapidly progressive disease postrelapse. To study this interaction, we investigated a transgenic model of MYCN-driven medulloblastoma and found spontaneous development ofTrp53inactivating mutations. Abrogation of p53 function in this model produced aggressive tumors that mimicked characteristics of relapsed human tumors with combined P53-MYC dysfunction. Restoration of p53 activity and genetic and therapeutic suppression of MYCN all reduced tumor growth and prolonged survival. Our findings identify P53-MYC interactions at medulloblastoma relapse as biomarkers of clinically aggressive disease that may be targeted therapeutically.Additional co-authors: Louise Howell, Colin Kwok, Abhijit Joshi, Sarah Leigh Nicholson, Stephen Crosier, David W. Ellison, Stephen B. Wharton, Keith Robson, Antony Michalski, Darren Hargrave, Thomas S. Jacques, Barry Pizer, Simon Bailey, Fredrik J. Swartling, William A. Weiss, Louis Chesler, Steven C. Cliffor
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