2,754 research outputs found
Influence of intervals of radiant heat on performance and pacing dynamics during rowing exercise
Abstract: The purpose of this study was to investigate whether intervals of radiant heat during thermoneutral exercise altered either the performance outcome or the dynamics of pacing within the exercise bout. Eleven male participants ( ; 56 ± 12 ml∙kg-1∙min-1) performed three 5000m exercise trials on a rowing ergometer in three different conditions, in a random order. The participants were either: non-warmed (NW), warmed (W), or periodically warmed in intervals throughout each trial (IW). Warming was achieved using radiant heat lamps to raise the localised environmental temperature from 18 ˚C to 35 ˚C. Intervals of warming were applied over fixed periods of the 5000m bouts between 1000-2000m (W1) and 3000-4000m (W2). The results of the experiment demonstrated that performance time and average power output of the 5000m matched intensity trials were not significantly different between conditions (p=0.10 ; p=0.189). However, the application of warming significantly reduced intra-trial power output during the first (W1) interval in the IW condition (p=0.03) but not during the second (W2) warming interval (p=0.10). Tsk increased by 0.51˚C (p=0.05) in response to the application of warming during W1 in the IW condition and by 0.15 ˚C in W2 (p=0.28). No significant between-condition differences were observed in Tc throughout the trials. These findings suggest that an abrupt change to environmental conditions brought about through intervals of radiant warming can affect the transient pacing dynamics of an exercise bout, but not necessarily impact overall performance time. Performance time appears unaffected by intervals of radiant heat during an exercise bout, although further work is required in more challenging dynamic environmental conditions
Archäologische Prospektionen im Brüniggebiet - Vorbericht zur Prospektionskampagne 2014 in Lungern (OW) und Meiringen (BE)
Das Bronzemesser lag – wie auch ein Teil der mittelalterlichen Silberpfennige und verschiedene im Jahr 2014 gefundene (früh-)neuzeitliche Metallobjekte – unmittelbar auf der Laubdecke, d.h. auf der Oberkante des humosen Oberbodens (Ah-Horizont). Dies zeigt, dass die Bodenbildungsprozesse im Brüniggebiet äusserst langsam verlaufen und sich deswegen unterschiedlich alte Fundobjekte oftmals im gleichen stratigraphischen Kontext finden. Bei einer der untersuchten Trockenmauerkonstruktion am Nordrand der Geländestufe könnten Lage, Befund und Funde dafür sprechen, dass es sich um eine der „Hütten“ bzw. „Wachthütten“ handeln könnte, die von den Unterwaldnern im Zusammenhang mit dem Grenzkonflikt im Jahre 1712 errichtet wurden. Wichtige Hinweise für die Interpretation und Einordnung der diesjährigen und und früheren Prospektionsergebnisse lieferte die Transkription und Analyse des „Plan und Grundriss von dem grossen Pass über den so genannten Breünig Berg“ des Ingenieurs und Artillerieoffiziers Samuel Bodmer aus dem Jahr 1712 – auch wenn sich die Lokalisierung der verschiedenen militärischen und zivilen Bauten im Einzelfall ein schwieriges Unterfangen bleibt. Im Sinne einer ganzheitlichen Betrachtung der archäologisch-historischen Situation im Bereich des Brünig wurde im Berichtsjahr erstmals und mit Erfolg auch auf dem Gebiet der Gemeinde Meiringen (BE) prospektiert und erste Vorarbeiten und Abklärungen im Hinblick auf die geplante Dokumentation der erstaunlich gut erhaltenen Überreste des zwischen 1712 und 1714 errichteten „Schäntzli Nydegg“ durchgeführt
The role of pacing in sub-maximal and maximal intensity exercise: impacts of environmental and protocol manipulations
The purpose of this thesis was to investigate the role of pacing in the development of fatigue through four studies which examined the impact of environmental and protocol manipulations, and evaluated the role of an ability to fluctuate pace during exercise at sub-maximal and maximal intensities. The role of self-pacing in exercise protocols represents a distinct contrast to the use of enforced-pace exercise common in many conventional scientific protocols, and thus required the development of novel methodologies, relevant to current sporting practices, which were shown to demonstrate validity and reliability using a range of contemporary measures.
Chapters 1-3 of this thesis provided a rationale for the studies, a review of relevant literature, and an overview of the scientific methodologies common to the studies.
The study in Chapter 4 reported the findings of an investigation comparing 1) selfpaced and 2) enforced-pace exercise at matched intensities. This study demonstrated that self-paced exercise poses a reduced metabolic challenge when compared to matched-intensity enforced-pace exercise. The study findings suggest that the ability to voluntarily fluctuate power output in accordance with transient sensations of fatigue may represent an important physiological mechanism used during self-paced exercise to defend homeostasis.
The study in Chapter 5 reported the test-retest reliability of a self-paced perceptually regulated time-trial by comparing power output responses within- and between-groups of aerobically-matched participants. Using a range of reliability measures this study showed that all participants were able to reliably reproduce the same power output over 5000m at a fixed rate of perceived exertion (RPE 15) providing evidence of the reliability of a sub-maximal time-trial protocol based on a fixed RPE score both withingroups and between independently sampled groups.
Chapter 6 reported a study which investigated the effects of intervals of radiant warming and thermoneutral conditions on pacing during a sub-maximal perceptually regulated exercise test. Participants completed 5000m rowing trials in 1) warmed, 2) non-warmed, or 3) interval-warmed conditions. Dynamic analysis of results showed a significant reduction in power during the first warming bout in the interval warmed condition, which was unobserved in the second period of warming. The ability to complete each exercise bout with similar average power and performance time, despite significant changes to pacing within the trial demonstrated evidence of a multi-level pacing plan with the capacity to alter effort during a bout in response to thermal challenges, but without impact to overall performance within a trial.
The final study in Chapter 7 reported the design of a novel perceptually regulated test of maximal aerobic power. The study compared physiological and performance responses to repeated 1) self-paced perceptually regulated maximal exercise tests and 2) conventional incremental maximal exercise tests. Similar peak power outputs and VO2peak were observed in the self-paced and conventional, enforced pace exercise tests (p>0.05). The findings of this study validated a reliable self-paced maximal exercise test (VO2peak CV<1%; icc 0.999) that presents a protocol which can be applied across multiple modalities, furthermore the dynamic analysis of the performance responses in this novel protocol provided evidence of energy-sparing pacing behaviours unobservable using conventional measures.
This thesis has shown the importance of self-pacing in exercise through outcomes which cannot be demonstrated when the pace of an exercise bout is externally enforced. The imposition of an enforced pace results in an increased physiological demand in response to a mode of performance that is unrelated to current sporting practices. The positive impact of self-pacing on performance and physiological variables demonstrated in this thesis suggests that the ability to vary pace, under the influence of a model of complex metabolic control, is fundamental to optimal performance, and the incorporation of self-paced protocols in exercise testing is vital to the continued development of models of fatigue
Development of the nanobody display technology to target lentiviral vectors to antigen-presenting cells
Lentiviral vectors (LVs) provide unique opportunities for the development of immunotherapeutic strategies, as they transduce a variety of cells in situ, including antigen-presenting cells (APCs). Engineering LVs to specifically transduce APCs is required to promote their translation towards the clinic. We report on the Nanobody (Nb) display technology to target LVs to dendritic cells (DCs) and macrophages. This innovative approach exploits the budding mechanism of LVs to incorporate an APC-specific Nb and a binding-defective, fusion-competent form of VSV. G in the viral envelope. In addition to production of high titer LVs, we demonstrated selective, Nb-dependent transduction of mouse DCs and macrophages both in vitro and in situ. Moreover, this strategy was translated to a human model in which selective transduction of in vitro generated or lymph node (LN)-derived DCs and macrophages, was demonstrated. In conclusion, the Nb display technology is an attractive approach to generate LVs targeted to specific cell types
Practice to pitch: The relationship between force-velocity profiles and match-day performance of semi-professional rugby union players
IntroductionThis exploratory study aimed to assess the relationship between athlete neuromuscular performance and rugby performance indicators. Specifically, the study looked at the force-velocity profiles (FVPs) derived from four common resistance exercises and their relationship with rugby performance indicators (RPIs).MethodsThe study recruited twenty-two semi-professional male rugby players (body mass 102.5 ± 12.6 kg, height 1.85 ± 0.74 m, age 24.4 ± 3.4 years) consisting of ten backs and twelve forwards. Prior to the first game of a Covid-impacted nine-match season, participants performed four common resistance exercises (barbell box squat, jammer push-press, sled pull, and sled push) at incremental loads to establish force-velocity profiles. During the season, rugby performance indicators (post-contact metres, tries, turnovers conceded, tackles, try assists, metres ran, defenders beaten, and tackle breaks) were collated from two trusted sources by a performance analyst. Correlational analyses were used to determine the relationship between the results of FVPs and RPIs.ResultsThe study found a statistically significant, moderate, positive correlation between tackle-breaks and sled push V0 (r = .35, p = .048). Significant, large, positive correlations were also found between tackles and jammer push-press V0 (r = .53, p = .049) and tackle-breaks and sled pull F0 (r = .53, p = .03). There was a significant, negative relationship between sled pull V0 and tackle-breaks (r = −.49, p = .04). However, the largest, significant correlation reported was between metres ran and sled pull F0 (r = .66, p = .03).ConclusionThe study suggests that a relationship may exist between FVPs of particular exercises and RPIs, but further research is required to confirm this. Specifically, the results suggest that horizontal resistance training may be best to enhance RPIs (tackle-breaks, tackles, and metres ran). The study also found that maximal power was not related to any rugby performance indicator, which suggests that a specified prescription of either force or velocity dominant exercises to enhance RPIs may be warranted
Neighborhood regulation by lncRNA promoters, transcription, and splicing
Mammalian genomes are pervasively transcribed to produce thousands of spliced long noncoding RNAs (lncRNAs), whose functions remain poorly understood. Because recent evidence has implicated several specific lncRNA loci in the local regulation of gene expression, we sought to determine whether such local regulation is a property of many lncRNA loci. We used genetic manipulations to dissect 12 genomic loci that produce lncRNAs and found that 5 of these loci influence the expression of a neighboring gene in cis. Surprisingly, however, none of these effects required the specific lncRNA transcripts themselves and instead involved general processes associated with their production, including enhancer-like activity of gene promoters, the process of transcription, and the splicing of the transcript. Interestingly, such effects are not limited to lncRNA loci: we found similar effects on local gene expression at 4 of 6 protein-coding loci. These results demonstrate that 'crosstalk' among neighboring genes is a prevalent phenomenon that can involve multiple mechanisms and cis regulatory signals, including a novel role for RNA splicing. These mechanisms may explain the function and evolution of some genomic loci that produce lncRNAs
RNA-RNA Interactions Enable Specific Targeting of Noncoding RNAs to Nascent Pre-mRNAs and Chromatin Sites
Intermolecular RNA-RNA interactions are used by many noncoding RNAs (ncRNAs) to achieve their diverse functions. To identify these contacts, we developed a method based on RNA antisense purification to systematically map RNA-RNA interactions (RAP-RNA) and applied it to investigate two ncRNAs implicated in RNA processing: U1 small nuclear RNA, a component of the spliceosome, and Malat1, a large ncRNA that localizes to nuclear speckles. U1 and Malat1 interact with nascent transcripts through distinct targeting mechanisms. Using differential crosslinking, we confirmed that U1 directly hybridizes to 5′ splice sites and 5′ splice site motifs throughout introns and found that Malat1 interacts with pre-mRNAs indirectly through protein intermediates. Interactions with nascent pre-mRNAs cause U1 and Malat1 to localize proximally to chromatin at active genes, demonstrating that ncRNAs can use RNA-RNA interactions to target specific pre-mRNAs and genomic sites. RAP-RNA is sensitive to lower abundance RNAs as well, making it generally applicable for investigating ncRNAs
Association between the COVID-19 pandemic and insurance-based disparities in mortality after major surgery among US adults
Importance: The COVID-19 pandemic caused significant disruptions in surgical care. Whether these disruptions disproportionately impacted economically disadvantaged individuals is unknown.
Objective: To evaluate the association between the COVID-19 pandemic and mortality after major surgery among patients with Medicaid insurance or without insurance compared with patients with commercial insurance.
Design, Setting, and Participants: This cross-sectional study used data from the Vizient Clinical Database for patients who underwent major surgery at hospitals in the US between January 1, 2018, and May 31, 2020.
Exposures: The hospital proportion of patients with COVID-19 during the first wave of COVID-19 cases between March 1 and May 31, 2020, stratified as low (≤5.0%), medium (5.1%-10.0%), high (10.1%-25.0%), and very high (\u3e25.0%).
Main Outcomes and Measures: The main outcome was inpatient mortality. The association between mortality after surgery and payer status as a function of the proportion of hospitalized patients with COVID-19 was evaluated with a quasi-experimental triple-difference approach using logistic regression.
Results: Among 2 950 147 adults undergoing inpatient surgery (1 550 752 female [52.6%]) at 677 hospitals, the primary payer was Medicare (1 427 791 [48.4%]), followed by commercial insurance (1 000 068 [33.9%]), Medicaid (321 600 [10.9%]), other payer (140 959 [4.8%]), and no insurance (59 729 [2.0%]). Mortality rates increased more for patients undergoing surgery during the first wave of the pandemic in hospitals with a high COVID-19 burden (adjusted odds ratio [AOR], 1.13; 95% CI, 1.03-1.24; P = .01) and a very high COVID-19 burden (AOR, 1.38; 95% CI, 1.24-1.53; P \u3c .001) compared with patients in hospitals with a low COVID-19 burden. Overall, patients with Medicaid had 29% higher odds of death (AOR, 1.29; 95% CI, 1.22-1.36; P \u3c .001) and patients without insurance had 75% higher odds of death (AOR, 1.75; 95% CI, 1.55-1.98; P \u3c .001) compared with patients with commercial insurance. However, mortality rates for surgical patients with Medicaid insurance (AOR, 1.03; 95% CI, 0.82-1.30; P = .79) or without insurance (AOR, 0.85; 95% CI, 0.47-1.54; P = .60) did not increase more than for patients with commercial insurance in hospitals with a high COVID-19 burden compared with hospitals with a low COVID-19 burden. These findings were similar in hospitals with very high COVID-19 burdens.
Conclusions and Relevance: In this cross-sectional study, the first wave of the COVID-19 pandemic was associated with a higher risk of mortality after surgery in hospitals with more than 25.0% of patients with COVID-19. However, the pandemic was not associated with greater increases in mortality among patients with no insurance or patients with Medicaid compared with patients with commercial insurance in hospitals with a very high COVID-19 burden
Interest in Co-located Reproductive and Sexual Health Services Among Women and Men Receiving Medication for Opioid Use Disorder in an Outpatient Treatment Clinic
Introduction Reproductive and sexual health (RSH) are core components of comprehensive care, yet often omitted in addiction treatment. We characterize knowledge of and interest in RSH services and contraceptive method awareness and use in a rural, Appalachian outpatient clinic. Materials and Methods Between September 2016 and April 2018, a convenience sample of 225 patients receiving treatment for opioid use disorder at an outpatient buprenorphine/naloxone clinic was collected. Participants completed a cross-sectional RSH survey that included demographics, interest in RSH service integration, contraceptive use, and contraceptive knowledge. Results A total of 212 people (126 non-pregnant women, 29 pregnant women, and 57 men) completed the survey of whom 45.8% indicated interest in adding RSH services. Services of interest include regular physical exams (44.8%), STI/STD testing (41.0%), and contraception education and administration (38.2%). There were no significant differences between interest in co-located services between women and men (P = 0.327). Current contraceptive use was low (17.9–30.9%) among women and men. Contraceptive method awareness was 43.3% for high efficacy methods and 50.0% for medium efficacy methods. Women and currently pregnant women knew more total, high, and medium efficacy contraceptive method than men (P = 0.029). Discussion Both women and men in this sample are interested in co-located RSH services. Current contraceptive use was low among participants. Contraceptive knowledge was lower among men compared to women, and generally low. Providing co-located RSH services may facilitate RSH education, contraceptive method uptake, and promote engagement across various RSH domains
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