1,319 research outputs found
The Drosophila genome nexus: a population genomic resource of 623 Drosophila melanogaster genomes, including 197 from a single ancestral range population.
Hundreds of wild-derived Drosophila melanogaster genomes have been published, but rigorous comparisons across data sets are precluded by differences in alignment methodology. The most common approach to reference-based genome assembly is a single round of alignment followed by quality filtering and variant detection. We evaluated variations and extensions of this approach and settled on an assembly strategy that utilizes two alignment programs and incorporates both substitutions and short indels to construct an updated reference for a second round of mapping prior to final variant detection. Utilizing this approach, we reassembled published D. melanogaster population genomic data sets and added unpublished genomes from several sub-Saharan populations. Most notably, we present aligned data from phase 3 of the Drosophila Population Genomics Project (DPGP3), which provides 197 genomes from a single ancestral range population of D. melanogaster (from Zambia). The large sample size, high genetic diversity, and potentially simpler demographic history of the DPGP3 sample will make this a highly valuable resource for fundamental population genetic research. The complete set of assemblies described here, termed the Drosophila Genome Nexus, presently comprises 623 consistently aligned genomes and is publicly available in multiple formats with supporting documentation and bioinformatic tools. This resource will greatly facilitate population genomic analysis in this model species by reducing the methodological differences between data sets
Modeling the RXTE light curve of Carinae from a 3-D SPH simulation of its binary wind collision
The very massive star system Carinae exhibits regular 5.54-year
(2024-day) period disruptive events in wavebands ranging from the radio to
X-ray. There is a growing consensus that these events likely stem from
periastron passage of an (as yet) unseen companion in a highly eccentric
() orbit. This paper presents three-dimensional (3-D)
Smoothed Particle Hydrodynamics (SPH) simulations of the orbital variation of
the binary wind-wind collision, and applies these to modeling the X-ray light
curve observed by the Rossi X-ray Timing Explorer (RXTE). By providing a global
3-D model of the phase variation of the density of the interacting winds, the
simulations allow computation of the associated variation in X-ray absorption,
presumed here to originate from near the apex of the wind-wind interaction
cone. We find that the observed RXTE light curve can be readily fit if the
observer's line of sight is within this cone along the general direction of
apastron. Specifically, the data are well fit by an assumed inclination for the orbit's polar axis, which is thus consistent with orbital
angular momentum being along the inferred polar axis of the Homunculus nebula.
The fits also constrain the position angle that an orbital-plane
projection makes with the apastron side of the semi-major axis, strongly
excluding positions along or to the retrograde side of the
axis, with the best fit position given by . Overall the
results demonstrate the utility of a fully 3-D dynamical model for constraining
the geometric and physical properties of this complex colliding-wind binary
system.Comment: 5 pages, 4 figures, accepted to MNRAS Letter
REMOTE INFLUENCE OF HUMAN PHYSIOLOGY BY A RITUAL HEALING TECHNIQUE
Two experiments tested the hypothesis that remote calming effects of a traditional healing ritual can be objectively measured using indicators of electrodermal activity, heart rate and blood volume. A total of 14 sessions were conducted in the initial study and 16 sessions were conducted in the replication. In both experiments, the authors exchanged roles as experimenter, healer and patient. Healers were instructed to try to calm the remote patient using a set of traditional ritual magic strategies, or to exert no influence (as a control). The patient created a doll in his or her likeness and provided mementos, pictures and an autobiographical sketch. The healer used these materials to form a sympathetic connection with the patient who was located in another building in an isolated toom. During the experiments, there were no other connections between the healer and the patient. Each session consisted of a randomized counterbalanced sequence of five calming and five control epochs of one minute each. No performance feedback was provided to the healer or patient during the session. The combined results of both experiments showed significant effects for changes in blood volume (p = .00002), heart rate (p = .001) and electrodermal activity (p = .013), suggesting that traditional magic healing rituals caused significant relaxation of the vascular system and arousal of electrodermal activity. These rituals appear to be helpful in focusing mental intention in laboratory investigations of direct mental interactions with living systems
REMOTE INFLUENCE OF HUMAN PHYSIOLOGY BY A RITUAL HEALING TECHNIQUE
Two experiments tested the hypothesis that remote calming effects of a traditional healing ritual can be objectively measured using indicators of electrodermal activity, heart rate and blood volume. A total of 14 sessions were conducted in the initial study and 16 sessions were conducted in the replication. In both experiments, the authors exchanged roles as experimenter, healer and patient. Healers were instructed to try to calm the remote patient using a set of traditional ritual magic strategies, or to exert no influence (as a control). The patient created a doll in his or her likeness and provided mementos, pictures and an autobiographical sketch. The healer used these materials to form a sympathetic connection with the patient who was located in another building in an isolated toom. During the experiments, there were no other connections between the healer and the patient. Each session consisted of a randomized counterbalanced sequence of five calming and five control epochs of one minute each. No performance feedback was provided to the healer or patient during the session. The combined results of both experiments showed significant effects for changes in blood volume (p = .00002), heart rate (p = .001) and electrodermal activity (p = .013), suggesting that traditional magic healing rituals caused significant relaxation of the vascular system and arousal of electrodermal activity. These rituals appear to be helpful in focusing mental intention in laboratory investigations of direct mental interactions with living systems
Postexercise hot-water immersion does not further enhance heat adaptation or performance in endurance athletes training in a hot environment
Purpose: Hot-water immersion (HWI) after training in temperate conditions has been shown to induce thermophysiological adaptations and improve endurance performance in the heat; however, the potential additive effects of HWI and training in hot outdoor conditions remain unknown. Therefore, this study aimed to determine the effect of repeated postexercise HWI in athletes training in a hot environment. Methods: A total of 13 (9 female) elite/preelite racewalkers completed a 15-day training program in outdoor heat (mean afternoon high temperature = 34.6°C). Athletes were divided into 2 matched groups that completed either HWI (40°C for 30–40 min) or seated rest in 21°C (CON), following 8 training sessions. Pre–post testing included a 30-minute fixed-intensity walk in heat, laboratory incremental walk to exhaustion, and 10,000-m outdoor time trial. Results: Training frequency and volume were similar between groups (P = .54). Core temperature was significantly higher during immersion in HWI (38.5 [0.3]) than CON (37.8°C [0.2°C]; P .05). There were significant (P < .05) pre–post differences for both groups in submaximal exercising heart rate (∼11 beats·min−1), sweat rate (0.34–0.55 L·h−1) and thermal comfort (1.2–1.5 arbitrary units), and 10,000-m racewalking performance time (∼3 min). Conclusions: Both groups demonstrated significant improvement in markers of heat adaptation and performance; however, the addition of HWI did not provide further enhancements. Improvements in adaptation appeared to be maximized by the training program in hot conditions
Post-exercise hot-water immersion does not further enhance heat adaptation or performance in endurance athletes training in hot environment
INTRODUCTION:
Hot-water immersion (HWI) after training in temperate conditions has been shown to induce thermophysiological adaptations and improve endurance performance in the heat, however, the potential additive effects of HWI and training in hot outdoor conditions remain unknown. Therefore, this study aimed to determine the effect of repeated post-exercise HWI in athletes training in a hot environment.
METHODS:
Thirteen (9 female) elite/pre-elite partially heat acclimatized racewalkers completed a 15-day training program in outdoor heat (mean afternoon high temperature=34.6°C). Athletes were divided into two groups matched for VO2max and 10,000 m walking performance time that completed either HWI (40°C for 30-40 min) or seated rest in 21°C (CON), following 8 training sessions. Pre-post testing included a 30-min fixed-intensity walk in heat, laboratory incremental walk to exhaustion and 10,000 m outdoor time-trial.
RESULTS:
Training frequency and volume was similar between groups (P=0.54). Core temperature was significantly higher during immersion in HWI (38.5 ± 0.3) than CON (37.8 ± 0.2°C; P0.05). There were significant (P<0.05) pre-post differences for both groups in submaximal exercising heart rate (~11 bpm) sweat rate (0.34-0.55 L.h-1) and thermal comfort (1.2–1.5 arbitrary units), and 10,000 m racewalking performance time (~3 min).
CONCLUSION:
After a 15-day heat training intervention, we observed significantly improved submaximal exercising heart rate, sweat rate, and thermal comfort, as well as improved 10,000 m racewalking performance in both groups. However, the addition of HWI did not further enhance heat adaptation or performance in partially heat-acclimatized athletes. Physiological adaptation appeared to be optimized from training in hot conditions alone
Hair cortisol as a biomarker of stress in mindfulness training for smokers.
OBJECTIVES: Stress is a well-known predictor of smoking relapse, and cortisol is a primary biomarker of stress. The current pilot study examined changes in levels of cortisol in hair within the context of two time-intensity matched behavioral smoking cessation treatments: mindfulness training for smokers and a cognitive-behavioral comparison group.
PARTICIPANTS: Eighteen participants were recruited from a larger randomized controlled trial of smoking cessation.
OUTCOME MEASURES: Hair samples (3 cm) were obtained 1 month after quit attempt, allowing for a retrospective analysis of hair cortisol at preintervention and post-quit attempt time periods. Self-reported negative affect was also assessed before and after treatment.
INTERVENTION: Both groups received a 7-week intensive intervention using mindfulness or cognitive-behavioral strategies.
RESULTS: Cortisol significantly decreased from baseline to 1 month after quit attempt in the entire sample (d=-0.35; p=.005). In subsequent repeated-measures analysis of variance models, time by group and time by quit status interaction effects were not significant. However, post hoc paired t tests yielded significant pre-post effects among those randomly assigned to the mindfulness condition (d=-0.48; p=.018) and in those abstinent at post-test (d=-0.41; p=.004). Decreased hair cortisol correlated with reduced negative affect (r=.60; p=.011).
CONCLUSIONS: These preliminary findings suggest that smoking cessation intervention is associated with decreased hair cortisol levels and that reduced hair cortisol may be specifically associated with mindfulness training and smoking abstinence. RESULTS support the use of hair cortisol as a novel objective biomarker in future research
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AAPM medical physics practice guideline 10.a.: Scope of practice for clinical medical physics.
The American Association of Physicists in Medicine (AAPM) is a nonprofit professional society whose primary purposes are to advance the science, education, and professional practice of medical physics. The AAPM has more than 8000 members and is the principal organization of medical physicists in the United States. The AAPM will periodically define new practice guidelines for medical physics practice to help advance the science of medical physics and to improve the quality of service to patients throughout the United States. Existing medical physics practice guidelines will be reviewed for the purpose of revision or renewal, as appropriate, on their fifth anniversary or sooner. Each medical physics practice guideline (MPPG) represents a policy statement by the AAPM, has undergone a thorough consensus process in which it has been subjected to extensive review, and requires the approval of the Professional Council. The medical physics practice guidelines recognize that the safe and effective use of diagnostic and therapeutic radiation requires specific training, skills, and techniques as described in each document. As the review of the previous version of AAPM Professional Policy (PP)-17 (Scope of Practice) progressed, the writing group focused on one of the main goals: to have this document accepted by regulatory and accrediting bodies. After much discussion, it was decided that this goal would be better served through a MPPG. To further advance this goal, the text was updated to reflect the rationale and processes by which the activities in the scope of practice were identified and categorized. Lastly, the AAPM Professional Council believes that this document has benefitted from public comment which is part of the MPPG process but not the AAPM Professional Policy approval process. The following terms are used in the AAPM's MPPGs: Must and Must Not: Used to indicate that adherence to the recommendation is considered necessary to conform to this practice guideline. Should and Should Not: Used to indicate a prudent practice to which exceptions may occasionally be made in appropriate circumstances
Antigiardial activity of novel guanidine compounds
From four focused compound libraries based on the known anticoccidial agent robenidine, 44 compounds total were synthesised and screened for antigiardial activity. All active compounds were counter-screened for antibiotic and cytotoxic action. Of the analogues examined, 21 displayed IC50<5 μM, seven with IC50<1.0 μM. Most active were 2,2′-bis{[4-(trifluoromethoxy)phenyl]methylene}carbonimidic dihydrazide hydrochloride (30), 2,2′-bis{[4-(trifluoromethylsulfanyl)phenyl]methylene}carbonimidic dihydrazide hydrochloride (32), and 2,2′-bis[(2-bromo-4,5-dimethoxyphenyl)methylene]carbonimidic dihydrazide hydrochloride (41) with IC50=0.2 μM. The maximal observed activity was a 5 h IC50 value of 0.2 μM for 41. The clinically used metronidazole was inactive at this timepoint at a concentration of 25 μM. Robenidine off-target effects at bacteria and cell line toxicity were removed. Analogue 41 was well tolerated in mice treated orally (100 mg/kg). Following 5 h treatment with 41, no Giardia regrowth was noted after 48 h
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