358 research outputs found

    Somatic hybridisation using a double mutant of Nicotiana tabacum

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    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

    Microscopic dynamics in liquid metals: the experimental point of view

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    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

    Effects of oxidized lipids (4,5 (E)-epoxy-2(E)-heptenal and 4,5 (E)-epoxy-2 (E) -decenal) and lysine reaction products on zinc and calcium utilization: assays in Caco-2 cells

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    The influence of the presence of brown products from the reaction between two oxidized lipids (4,5 (E)-epoxy-2(E)-heptenal, EH, and 4,5 (E)-epoxy-2 (E)-decenal, ED) and lysine (EH-L and ED-L) on zinc and calcium utilization was studied, and compared with a fructosyl-lysine mixture (F-L). Assays were carried out in Caco-2 cells grown in bicameral chambers. The Zn transported across the cell monolayer was significantly lower in the presence of the EH-L, ED-L and F-L samples, specially with EH-L. Significant decreases in Zn uptake were also observed, with no differences between samples. However, calcium transport was not modified. Thus, the assayed lipid-aminoacid brown products seem to have negative effects on Zn availability, whereas Ca availability appears to be unaffected.Se estudió la influencia de la presencia de productos obtenidos en la reacción de dos lípidos oxidados (4,5(E)-epoxy-2(E)- heptenal, EH, y 4,5(E)-epoxy-2(E)-decenal, ED) con el aminoácido lisina (EH-L y ED-L), sobre la absorción de zinc y calcio, comparándolos frente a una mezcla de fructosil-lisina (F-L). Los ensayos se realizaron con células Caco-2 sembradas en placas bicamerales. La adición de las muestras EH-L, ED-L y F-L al medio de cultivo supuso una reducción significativa en el Zn transportado a través de la monocapa de células, mucho más marcada ante la presencia de EH-L. También se redujo significativamente la captación celular de Zn, sin diferencias entre las distintas muestras ensayadas. Sin embargo, el transporte de Ca no se vio modificado. Por lo tanto, los productos pardos lípido-aminoacídicos ensayados parecen afectar negativamente la disponibilidad del Zn, sin tener efectos notables sobre la del Ca.Peer reviewe

    Can group-based strategies increase community resilience? Longitudinal predictors of sustained participation in Covid-19 mutual aid and community support groups

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    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.

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    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

    Aerial detection of beached marine plastic using a novel, hyperspectral short-wave infrared (SWIR) camera

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    Plastic pollution in the marine environment is a pervasive, global problem that threatens wildlife and human health. Routine monitoring is required to determine pollution hotspots, focus clean-up efforts, and assess the efficacy of legislation implemented to reduce environmental contamination. The shoreline represents an accessible area, relative to open water, from which to monitor this. Unmanned aerial vehicles (UAVs) offer a low-cost platform for remote sensing that operates below cloud coverage, which can interfere with satellite imagery. Detection of plastic using visible light is limited however, and results may be improved by using short-wave infrared (SWIR) imagery to collect chemical information. Within the commercial recycling industry, plastic items are sorted successfully based on their composition using SWIR instrumentation that measures the chemical spectra of waste items under controlled illumination. Here, proof of concept is established for aerial detection of domestic and shoreline-harvested plastic items on a beach under natural sunlight with a lightweight (800 g), hyperspectral SWIR camera deployed at an altitude of ∼ 5 m over ∼ 30-m transects. The results of spectral correlation mapping to compare imagery spectra to polyethylene and polypropylene reference spectra demonstrate that these two polymers can be successfully detected with this novel method

    PAin SoluTions In the Emergency Setting (PASTIES)—patientcontrolled analgesia versus routine care in emergency department patients with pain from traumatic injuries: Randomised trial

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    Objective To determine whether patient controlled analgesia (PCA) is better than routine care in patients presenting to emergency departments with moderate to severe pain from traumatic injuries.Design Pragmatic, multicentre, parallel group, randomised controlled trial.Setting Five English hospitals.Participants 200 adults (71% (n=142) male), aged 18 to 75 years, who presented to the emergency department requiring intravenous opioid analgesia for the treatment of moderate to severe pain from traumatic injuries and were expected to be admitted to hospital for at least 12 hours.Interventions PCA (n=99) or nurse titrated analgesia (treatment as usual; n=101).Main outcome measures The primary outcome was total pain experienced over the 12 hour study period, derived by standardised area under the curve (scaled from 0 to 100) of each participant’s hourly pain scores, captured using a visual analogue scale. Pre-specified secondary outcomes included total morphine use, percentage of study period in moderate/severe pain, percentage of study period asleep, length of hospital stay, and satisfaction with pain management.Results 200 participants were included in the primary analyses. Mean total pain experienced was 47.2 (SD 21.9) for the treatment as usual group and 44.0 (24.0) for the PCA group. Adjusted analyses indicated slightly (but not statistically significantly) lower total pain experienced in the PCA group than in the routine care group (mean difference 2.7, 95% confidence interval −2.4 to 7.8). Participants allocated to PCA used more morphine in total than did participants in the treatment as usual group (mean 44.3 (23.2) v 27.2 (18.2) mg; mean difference 17.0, 11.3 to 22.7). PCA participants spent, on average, less time in moderate/severe pain (36.2% (31.0) v 44.1% (31.6)), but the difference was not statistically significant. A higher proportion of PCA participants reported being perfectly or very satisfied compared with the treatment as usual group (86% (78/91) v 76% (74/98)), but this was also not statistically significant.Conclusions PCA provided no statistically significant reduction in pain compared with routine care for emergency department patients with traumatic injuries.Trial registration European Clinical Trials Database EudraCT2011-000194-31; Current Controlled Trials ISRCTN25343280

    Post-activation Potentiation: Effect of Recovery Duration and Gender on Countermovement Jump, Agility, and Linear Speed in Team-Sport Athletes

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    Background: Studies assessing post-activation potentiation (PAP) responses comparing male and female athletes are conflicting. Objectives: This study investigated whether differences exist in the duration for optimal post-preload stimulus measures on performance in male and female team sport athletes. Methods: Twenty-four participants (12 males and 12 females) participated in the study. Two familiarization sessions were conducted with each participant. Then, three experimental conditions were implemented, incorporating a standardized warm-up, followed by back squats (conditioning exercises) and varying passive recovery times of 4 min (PAP4), 8 min (PAP8), or 12 min (PAP12). Following the recovery, players performed three physical performance measures related to team sports: A countermovement jump, a modified agility t-test, and a 20-m linear sprint. The significance level was set at P < 0.05. Results: All performance measures were significantly greater in PAP12 than in PAP4 and PAP8 conditions in both males (1.50 to 2.95%) and females (1.09 to 5.79%) (P < 0.05). The PAP12 condition also had significantly lower values for HR (3.18 to 5.15 beats.min-1; P < 0.0005) and ratings of perceived exertion (RPE) (0.63 to 1.02; P < 0.05) than PAP8 and PAP4. Males performed better on all the performance tests (19.33 to 26.34%) compared to their female counterparts (P < 0.0005). Conclusions: A pre-load stimulus consisting of one set of 5 repetitions of back squat at 85% one-repetition maximum can elicit a PAP response. A 12-min passive rest after the pre-load stimulus was most beneficial in improving physical performance measures in both male and female team-sport athletes

    On having bad persons as friends

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    Intuitively, one who counts a morally bad person as a friend has gone wrong somewhere. But it is far from obvious where exactly they have gone astray. Perhaps in cultivating a friendship with a bad person, one extends to them certain goods that they do not deserve. Or perhaps the failure lies elsewhere; one may be an abettor to moral transgressions. Yet another option is to identify the mistake as a species of imprudence—one may take on great personal risk in counting a bad person as a friend. In this paper, I argue that none of these intuitive explanations are entirely convincing; for many such proposals run contrary to widely accepted features of friendship. However, they do point us in the direction of a more satisfying explanation—one which concerns a person’s moral priorities. An individual who counts a morally bad person as a friend is, I propose, one who betrays a distinct kind of defect in her values
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