309 research outputs found
Somatic hybridisation using a double mutant of Nicotiana tabacum
Leaf mesophyll protoplasts of a nitrate reductase deficient, streptomycin resistant double mutant of Nicotiana tabacum were fused with cell suspension protoplasts of wild type N. rustica. Hybrid colonies were selected for nitrate reductase proficiency and streptomycin resistance. Green, actively proliferating colonies were recovered in the selection medium. Eleven of twenty green colonies, transferred to regeneration medium, produced plants. Regenerated plants were analysed for their vegetative and floral characteristics, Fraction 1 protein polypeptide composition and leaf esterases. All the eleven regenerants were nuclear somatic hybrids possessing the chloroplast of the N. tabacum parent. By developing a double mutant with a negative (auxotrophic) and a positive (resistance) selection marker in a species of interest, this species can be hybridised by somatic cell fusion with wild type species lacking selectable markers
The bursting response of isolated avena coleoptile protoplasts to indol-3-ylacetic acid
'I found myself a despicable being!':Medical students face disturbing moral dilemmas
CONTEXT: The psychological realm of medical students` moral experiences is explored tangentially in medical education literature, often in the context of ethics or professionalism education. This study deepens our understanding by (1) investigating the nature of moral dilemmas experienced at the onset of clinical practice, (2) exploring students` emotional response to these dilemmas, and (3) examining how students perceive the influence of these dilemmas on their professional development. METHODS: This is a cross-sectional qualitative study carried out in 2017 that applied Thematic Template Analysis to individual interviews performed with last-year medical students. The interviews followed the drawing of a Rich Picture representing moral dilemmas experienced by medical students at the onset of clinical practice. RESULTS: Moral dilemmas have four intertwined dimensions. The first relates to students` struggle to prioritize, balance and apply conflicting moral values; the second comprises the clash between students` inner motivation and the external constraints that limit the moral action; the third refers to the conflict between students' current attitudes with the desired/idealized attitudes of the doctor they intend to become; the forth corresponds to weighting conflicting ethical principles during the moral decision. Students` emotional responses are intense, long-lasting, and with a remarkable residue effect, particularly when the moral decision does not align with their moral beliefs. Moral dilemmas are impactful experiences that affect the professional development of medical students and can culminate in both detachment or growth in moral courage. CONCLUSION: Moral dilemmas are memorable, complex, and emotionally intense experiences that impact the professional development of medical students. Understanding students` moral dilemmas can help educators to devise pedagogical activities to anticipate and reflect on these experiences. These activities should happen under the guidance of a non-judgmental facilitator, capable of listening and legitimating students' thoughts and feelings while providing insights to nurture their professional development
Microscopic dynamics in liquid metals: the experimental point of view
The experimental results relevant for the understanding of the microscopic
dynamics in liquid metals are reviewed, with special regards to the ones
achieved in the last two decades. Inelastic Neutron Scattering played a major
role since the development of neutron facilities in the sixties. The last ten
years, however, saw the development of third generation radiation sources,
which opened the possibility of performing Inelastic Scattering with X rays,
thus disclosing previously unaccessible energy-momentum regions. The purely
coherent response of X rays, moreover, combined with the mixed
coherent/incoherent response typical of neutron scattering, provides enormous
potentialities to disentangle aspects related to the collectivity of motion
from the single particle dynamics.
If the last twenty years saw major experimental developments, on the
theoretical side fresh ideas came up to the side of the most traditional and
established theories. Beside the raw experimental results, therefore, we review
models and theoretical approaches for the description of microscopic dynamics
over different length-scales, from the hydrodynamic region down to the single
particle regime, walking the perilous and sometimes uncharted path of the
generalized hydrodynamics extension. Approaches peculiar of conductive systems,
based on the ionic plasma theory, are also considered, as well as kinetic and
mode coupling theory applied to hard sphere systems, which turn out to mimic
with remarkable detail the atomic dynamics of liquid metals. Finally, cutting
edges issues and open problems, such as the ultimate origin of the anomalous
acoustic dispersion or the relevance of transport properties of a conductive
systems in ruling the ionic dynamic structure factor are discussed.Comment: 53 pages, 41 figures, to appear in "The Review of Modern Physics".
Tentatively scheduled for July issu
Can group-based strategies increase community resilience? Longitudinal predictors of sustained participation in Covid-19 mutual aid and community support groups
Mutual aid groups have been a critical part of the coronavirus disease-2019 (Covid-19) response and continue to address the needs of people in their communities. To understand how mutual aid and similar community support groups can be sustained over time, we test the idea that using group-based strategies initiates psychological trajectories that shape future participation. We conducted a preregistered longitudinal survey among Covid-19 mutual aid and community support volunteers in the United Kingdom (nWave 1 = 600, May 2021; nWave 2 = 299, July–August 2021) who were registered panelists of an independent research organization. Assessments included measures of group-based strategies, collective participation predictors, participation experience, and sustained participation. Volunteers engaged in a wide range of support activities including shopping, emotional support provision, and deliveries. Two group-based strategies—group alliances and group horizontality—longitudinally predicted sustained participation. In addition, sense of community responsibility and burnout were longitudinal predictors of sustained participation. Importantly, predictors of sustained participation diverged for volunteers with different levels of volunteering experience. Our findings highlight group-based strategies as a potential resource for organizers seeking to sustain participation. Use can be tailored depending on the profiles of individual Covid-19 mutual aid volunteers. These findings have significance beyond Covid-19 as they are relevant to sustaining community resilience more generally
Time-of-day variation on performance measures in repeated-sprint tests: A systematic review.
The lack of standardization of methods and procedures have hindered agreement in the literature related to time-of-day effects on repeated sprint performance and needs clarification. Therefore, the aim of the present study was to investigate and systematically review the evidence relating to time-of-day based on performance measures in repeated-sprints.
The entire content of PubMed (MEDLINE), Scopus, SPORTDiscus® (via EBSCOhost) and Web of Science was searched. Only experimental research studies conducted in male adult participants aged ≥18yrs, published in English before June 2019 were included. Studies assessing repeated-sprints between a minimum of two time-points during the day (morning versus evening) were deemed eligible.
The primary search revealed that a total of 10 out of 112 articles were considered eligible and subsequently included. Seven articles were deemed strong and three moderate quality. Eight studies found repeated-sprint performance across the first, first few, or all sprints, to increase in favor of the evening. The magnitude of difference is dependent on the modality and the exercise protocol used. The non-motorized treadmill established an average 3.5–8.5% difference in distance covered, average and peak velocity, and average power, across all sprints in three studies and in peak power in two studies. In cycling, power output differed across all sprints by 6.0% in one study and 8.0% for the first sprint only in five studies. All four studies measuring power decrement values (i.e. rate of fatigue) established differences up to 4.0% and two out of five studies established total work to be significantly higher by 8.0%.
Repeated-sprint performance is affected by time-of-day with greater performance in the late/early afternoon. The magnitude is dependent on the variable assessed and the mode of exercise. There is a clear demand for more rigorous investigations which control factors that specifically relate to investigations of time-of-day and are specific to the sport of individuals
The role of meat in the European diet: current state of knowledge on dietary recommendations, intakes and contribution to energy and nutrient intakes and status
The role of meat in the diet has come under scrutiny recently due to an increased public emphasis on providing healthy diets from sustainable food systems and due to health concerns relating to the consumption of red and processed meat. The present review aimed to summarise dietary guidelines relating to meat, actual meat intakes and the contribution of meat to energy and nutrient intakes of children, teenagers and adults in Europe. The available literature has shown that food-based dietary guidelines for most countries recommend consuming lean meat in moderation and many recommend limiting red and processed meat consumption. Mean intakes of total meat in Europe range from 40 to 160 g/d in children and teenagers and from 75 to 233 g/d in adults. Meat contributes to important nutrients such as protein, PUFA, B vitamins, vitamin D and essential minerals such as Fe and Zn; however, processed meat contributes to significant proportions of saturated fat and Na across population groups. While few data are available on diaggregated intakes of red and processed meat, where data are available, mean intakes in adults are higher than the upper limits recommended by the UK Scientific Advisory Committee on Nutrition (70 g/d) and the World Cancer Research Fund (500 g/week). While there are no recommendations for red and processed meat consumption in children and teenagers, intakes currently range from 30 to 76 g/d. The present review provides a comprehensive overview of the role of meat in the European diet which may be of use to stakeholders including researchers, policy makers and the agri-food sector
Evaluation of Simvastatin as a Disease-Modifying Treatment for Patients With Parkinson Disease: A Randomized Clinical Trial
\ua9 2022 American Medical Association. All rights reserved.Importance: Current treatments manage symptoms of Parkinson disease (PD), but no known treatment slows disease progression. Preclinical and epidemiological studies support the potential use of statins as disease-modifying therapy. Objective: To determine whether simvastatin has potential as a disease-modifying treatment for patients with moderate PD. Design, Setting, and Participants: This randomized clinical trial, a double-blind, parallel-group, placebo-controlled futility trial, was conducted between March 2016 and May 2020 within 23 National Health Service Trusts in England. Participants aged 40 to 90 years with a diagnosis of idiopathic PD, with a modified Hoehn and Yahr stage of 3.0 or less while taking medication, and taking dopaminergic medication with wearing-off phenomenon were included. Data were analyzed from May 2020 to September 2020, with additional analysis in February 2021. Interventions: Participants were allocated 1:1 to simvastatin or matched placebo via a computer-generated random sequence, stratified by site and Hoehn and Yahr stage. In the simvastatin arm, participants entered a 1-month phase of simvastatin, 40 mg daily, followed by 23 months of simvastatin, 80 mg daily, before a 2-month washout period. Main Outcomes and Measures: The prespecified primary outcome was 24-month change in Movement Disorder Society Unified Parkinson Disease Rating Scale (MDS-UPDRS) part III score measured while not taking medication (high scores indicate worse outcome). The primary futility analysis included participants who commenced the 80-mg phase and had valid primary outcome data. The safety analysis included all participants who commenced trial treatment and is reported by dose at time of event. Results: Of 332 patients assessed for eligibility, 32 declined and 65 were ineligible. Of 235 recruited participants, 97 (41%) were female, 233 (99%) were White, and the mean (SD) age was 65.4 (9.4) years. A total of 216 patients progressed to the 80-mg dose. Primary outcome analysis (n = 178) indicated the simvastatin group had an additional deterioration in MDS-UPDRS III score while not taking medication at 24 months compared with the placebo group (1.52 points; 2-sided 80% CI, -0.77 to 3.80; 1-sided futility test P =.006). A total of 37 serious adverse events (AEs), including 3 deaths, and 171 AEs were reported for participants receiving 0-mg simvastatin; 37 serious AEs and 150 AEs were reported for participants taking 40 mg or 80 mg of simvastatin. Four participants withdrew from the trial because of an AE. Conclusions and Relevance: In this randomized clinical trial, simvastatin was futile as a disease-modifying therapy in patients with PD of moderate severity, providing no evidence to support proceeding to a phase 3 trial. Trial Registration: ISRCTN Identifier: 16108482
Reconstitution of cytokeratin filaments in vitro: further evidence for the role of nonhelical peptides in filament assembly.
Evaluation of Simvastatin as a Disease-Modifying Treatment for Patients With Parkinson Disease: A Randomized Clinical Trial.
Importance: Current treatments manage symptoms of Parkinson disease (PD), but no known treatment slows disease progression. Preclinical and epidemiological studies support the potential use of statins as disease-modifying therapy. Objective: To determine whether simvastatin has potential as a disease-modifying treatment for patients with moderate PD. Design, Setting, and Participants: This randomized clinical trial, a double-blind, parallel-group, placebo-controlled futility trial, was conducted between March 2016 and May 2020 within 23 National Health Service Trusts in England. Participants aged 40 to 90 years with a diagnosis of idiopathic PD, with a modified Hoehn and Yahr stage of 3.0 or less while taking medication, and taking dopaminergic medication with wearing-off phenomenon were included. Data were analyzed from May 2020 to September 2020, with additional analysis in February 2021. Interventions: Participants were allocated 1:1 to simvastatin or matched placebo via a computer-generated random sequence, stratified by site and Hoehn and Yahr stage. In the simvastatin arm, participants entered a 1-month phase of simvastatin, 40 mg daily, followed by 23 months of simvastatin, 80 mg daily, before a 2-month washout period. Main Outcomes and Measures: The prespecified primary outcome was 24-month change in Movement Disorder Society Unified Parkinson Disease Rating Scale (MDS-UPDRS) part III score measured while not taking medication (high scores indicate worse outcome). The primary futility analysis included participants who commenced the 80-mg phase and had valid primary outcome data. The safety analysis included all participants who commenced trial treatment and is reported by dose at time of event. Results: Of 332 patients assessed for eligibility, 32 declined and 65 were ineligible. Of 235 recruited participants, 97 (41%) were female, 233 (99%) were White, and the mean (SD) age was 65.4 (9.4) years. A total of 216 patients progressed to the 80-mg dose. Primary outcome analysis (n = 178) indicated the simvastatin group had an additional deterioration in MDS-UPDRS III score while not taking medication at 24 months compared with the placebo group (1.52 points; 2-sided 80% CI, -0.77 to 3.80; 1-sided futility test P = .006). A total of 37 serious adverse events (AEs), including 3 deaths, and 171 AEs were reported for participants receiving 0-mg simvastatin; 37 serious AEs and 150 AEs were reported for participants taking 40 mg or 80 mg of simvastatin. Four participants withdrew from the trial because of an AE. Conclusions and Relevance: In this randomized clinical trial, simvastatin was futile as a disease-modifying therapy in patients with PD of moderate severity, providing no evidence to support proceeding to a phase 3 trial. Trial Registration: ISRCTN Identifier: 16108482
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