897 resultados para Aging. Mobility. Body Balance. Performance Muscle
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Four groups of yearling heifers representing different frame sizes—small, medium, and large Angus and medium Simmental—were fed high-grain finishing diets to average Low Choice quality grade. Half the heifers were implanted with estrogen and trenbolone acetate. Backfat and ribeye area were measured by ultrasound four times during the study to assess growth of muscle and fat. Increasing frame size resulted in increased feed intake, greater rates of gain, and a trend towards reduced feed conversion. Greater returns would have been realized from each of the four groups had they been sold in a premium market based on yield grade rather than the conventional grade and yield market. Increasing frame size resulted in greater returns to the value-based market. Implants increased rate of gain and improved feed conversion but did not result in significantly greater returns to the value-based market compared with the grade and yield market. Ribeye area and backfat increased with body weight and time on feed. Increase in ribeye area was linear with time, whereas accumulation of backfat was exponential. Rate of increase in area of ribeye tended to increase and backfat tended to decrease as frame size increased. Implants increased rate of increase in ribeye area but had no effect on rate of deposition of subcutaneous fat. Equations describing growth of ribeye area and backfat for each group predicted average growth for the heifers but did not predict growth of individual heifers. Final carcass yield grade was related to initial thickness of backfat but not to initial ribeye area. These results indicate that the type of cattle selected to be fed for a premium market based on yield grade is important to the success of the program. More work is needed to develop growth equations from ultrasound measurements, but ultrasound will likely be a useful tool in selecting feeder cattle for a value-based market.
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Cachexia is very common among patients with advanced pancreatic cancer and is a marker of poor prognosis. Weight loss in cachexia is due to both adipose and muscle compartments, and sarcopenia (severe muscle depletion) is associated with worse outcomes. Curcumin has shown a myriad of biological effects, including anti-cancer and anti-inflammatory. The ability of curcumin to attenuate cachexia and muscle loss has been tested in animal models, with conflicting results so far. The hypothesis of this study was that patients with advanced pancreatic cancer treated with curcumin for two months have less fat and muscle loss as compared to matched controls not treated with this compound. A matched 1:2 case-control retrospective study was conducted with 22 patients with pancreatic cancer who were treated with curcumin on a previous protocol and 44 untreated controls with the same diagnosis matched by age, gender, time from advanced cancer, body mass index, and number of prior therapies. Data was collected regarding oncologic treatment, medication use, weights, heights, and survival. Body composition was determined by computerized tomography analyses at two timepoints separated by 60±20 days. For treated patients, the first image was at the beginning of treatment and for controls it was determined by the matching time from advanced cancer. The evolution of body composition over time was quantitatively analyzed comparing both groups. All patients lost weight both due to fat and muscle losses, and patients treated with curcumin presented greater losses both in lean adipose body mass. Use of medications, chemotherapy, age, time from advanced cancer, baseline albumin, performance status, and number of prior therapies were not independently correlated with changes in body composition variables. Patients treated with curcumin had borderline shorter survival when compared with untreated patients. Sarcopenic treated patients had significantly shorter survival than non-sarcopenic counterparts, and sarcopenia status was not associated with survival among the controls. Treated patients with shorter survival showed a tendency to lose more lean and especially fat body mass as compared to untreated patients, maybe suggesting an effect of curcumin on shifting weight loss towards the end of life by impacting its mechanisms.
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Introduction Musicians often suffer injuries related to their music playing. Therefore, some use Alexander Technique (AT), a mental-physical method that facilitates to release unnecessary muscle tension and to re-educate non-beneficial movement patterns through enhanced kinaesthetic awareness. According to a recent review AT may be effective for chronic back pain [1]. This review aimed to evaluate the evidence for the effectiveness of AT lessons on music performance and musicians’ health and well-being. Methods The following electronic databases were searched up to July 2012 for relevant literature: PUBMED, Google Scholar, CINAHL and EMBASE. The search criteria were "Alexander technique" AND "music*" [all fields]. References were searched, and experts and societies of AT or musicians' medicine contacted for further publications. Results 100 studies were identified. 24 studies were included for further analysis, 5 of which were randomised controlled trials (RCTs), 5 controlled but not randomised (CTs), 5 without control group, 2 mixed methods (RCT and case studies), and 7 surveys. 13 to 72 musicians participated per RCT. In 5 RCTs AT groups received between 12 and 20 one-to-one lessons. In 4 RCTs control groups received no interventions. Primary outcomes were performance anxiety, music performance, "use" as well as respiratory function and pain. Performance anxiety decreased by AT in 3 of 4 RCTs and in 3 of 3 CTs. Music performance was improved by AT in 1 RCT, yet in 2 RCTs comparing neurofeedback (NF) to AT, only NF showed improvements. Discussion and Conclusion To investigate the effectiveness of AT in musicians a variety of study designs and outcome measures have been used. Evidence from RCTs suggests that AT may improve performance anxiety in musicians. Effects on music performance, body use and respiratory function yet remain inconsistent. Future trials with scientifically sound study designs are warranted to further and more reliably explore the potential of AT as a relatively low cost and low risk method in the interest of musicians. References [1] Woodman JP, Moore NR. Evidence for the effectiveness of Alexander Technique lessons in medical and health-related conditions: a systematic review. Int J Clin Pract 2012;66(1):98-112.
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Purpose Musicians often suffer injuries related to their music playing. Therefore, some use the Alexander Technique (AT), a psycho-physical method that helps to release unnecessary muscle tension and re-educates non-beneficial movement patterns through enhanced kinaesthetic awareness. According to a recent review AT may be effective for chronic back pain. This review aimed to evaluate the evidence for the effectiveness of AT lessons on music performance and musicians’ health and well-being. Methods The following electronic databases were searched up to July 2012 for relevant literature: PUBMED, Google Scholar, CINAHL and EMBASE. The search criteria were "Alexander technique" AND "music*" [all fields]. References were searched, and experts and societies of AT or musicians' medicine contacted for further publications. Results 100 studies were identified. 35 studies were included for further analysis, 5 of which were randomised controlled trials (RCTs), 5 controlled but not randomised, 5 not controlled, 5 qualitative case studies, 2 mixed-models (RCT and case studies), 7 surveys, 4 qualitative case reports and 2 unpublished pilot studies. 13 to 72 musicians participated per RCT. In 5 RCTs AT groups received between 12 and 20 one-to-one lessons. In 4 RCTs control groups received no interventions. Primary outcomes were performance anxiety, performance, "use" as well as respiratory function and pain. Performance anxiety decreased by AT in 3 of 4 RCTs. Music performance was improved by AT in 1 RCT, yet in 2 RCTs comparing neurofeedback (NF) to AT, only NF showed improvements. Conclusions To investigate the effectiveness of AT in musicians a variety of study designs and outcome measures have been used. Evidence from RCTs suggests that AT may improve performance anxiety in musicians. Effects on music performance, body use and respiratory function yet remain inconsistent. Future trials with well-established study designs are warranted to further and more reliably explore the potential of AT as a relatively low cost and low risk method in the interest of musicians.
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Over recent years, it has repeatedly been shown that optimal gaze strategies enhance motor control (e.g., Foulsham, 2015). However, little is known, whether, vice versa, visual performance can be improved by optimized motor control. Consequently, in two studies, we investigated visual performance as a function of motor control strategies and task parameters, respectively. In Experiment 1, 72 participants were tested on visual acuity (Landolt) and contrast sensitivity (Grating), while standing in two different postures (upright vs. squat) on a ZEPTOR-platform that vibrated at four different frequencies (0, 4, 8, 12 Hz). After each test, perceived exertion (Borg) was assessed. Significant interactions were revealed for both tests, Landolt: F(3,213)=13.25, p<.01, ηp2=.16, Grating: F(3,213)=4.27, p<.01, ηp2=.06, elucidating a larger loss of acuity/contrast sensitivity with increasing frequencies for the upright compared with the squat posture. For perceived exertion, however, a diametrical interaction for frequency was found for acuity, F(3,213)=7.45, p<.01, ηp2=.09, and contrast sensitivity, F(3,213)=7.08, p < .01, ηp2=.09, substantiating that the impaired visual performance cannot be attributed to exertion. Consequently, the squat posture could permit better head and, hence, gaze stabilization. In Experiment 2, 64 participants performed the same tests while standing in a squat position on a ski-simulator, which vibrated with two different frequencies (2.4, 3.6 Hz) and amplitudes (50, 100 mm) in a predictable or unpredictable manner. Control strategies were identified by tracking segmental motion, which allows to derive damping characteristics. Considerable main effects were found for frequency, all F’s(1,52)>10.31, all p’s<.01, all ηp2’s>.16, as well as, in the acuity test, for predictability, F(1,52)=10.31, p<.01, ηp2=.17, and by tendency for amplitude, F(1,52)=3.53, p=.06, ηp2=.06. A significant correlation between the damping amplitude in the knee joint and the performance drop in visual acuity, r=-.97, p<.001, again points towards the importance of motor control strategies to maintain optimal visual performance.
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BACKGROUND: Learning surgical skills in the operating room may be a challenge for medical students. Therefore, more approaches using simulation to enable students to develop their practical skills are required. OBJECTIVES: We hypothesized that (1) there would be a need for additional surgical training for medical students in the pre-final year, and (2) our basic surgery skills training program using fresh human skin would improve medical students' surgical skills. DESIGN: We conducted a preliminary survey of medical students to clarify the need for further training in basic surgery procedures. A new approach using simulation to teach surgical skills on human skin was set up. The procedural skills of 15 randomly selected students were assessed in the operating room before and after participation in the simulation, using Objective Structured Assessment of Technical Skills. Furthermore, subjective assessment was performed based on students' self-evaluation. The data were analyzed using SPSS, version 21 (SPSS, Inc., Chicago, IL). SETTING: The study took place at the Inselspital, Bern University Hospital. PARTICIPANTS: A total of 186 pre-final-year medical students were enrolled into the preliminary survey; 15 randomly selected medical students participated in the basic surgical skills training course on the fresh human skin operating room. RESULTS: The preliminary survey revealed the need for a surgical skills curriculum. The simulation approach we developed showed significant (p < 0.001) improvement for all 12 surgical skills, with mean cumulative precourse and postcourse values of 31.25 ± 5.013 and 45.38 ± 3.557, respectively. The self-evaluation contained positive feedback as well. CONCLUSION: Simulation of surgery using human tissue samples could help medical students become more proficient in handling surgical instruments before stepping into a real surgical situation. We suggest further studies evaluating our proposed teaching method and the possibility of integrating this simulation approach into the medical school curriculum.
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One of the reasons for animals not to grow as fast as they potentially could is that fast growth has been shown to be associated with reduced lifespan. However, we are still lacking a clear description of the reality of growth-dependent modulation of ageing mechanisms in wild animals. Using the particular growth trajectory of small king penguin chicks naturally exhibiting higher-than-normal growth rate to compensate for the winter break, we tested whether oxidative stress and telomere shortening are related to growth trajectories. Plasma antioxidant defences, oxidative damage levels and telomere length were measured at the beginning and at the end of the post-winter growth period in three groups of chicks (small chicks, which either passed away or survived the growth period, and large chicks). Small chicks that died early during the growth period had the highest level of oxidative damage and the shortest telomere lengths prior to death. Here, we show that small chicks that grew faster did it at the detriment of body maintenance mechanisms as shown by (i) higher oxidative damage and (ii) accelerated telomere loss. Our study provides the first evidence for a mechanistic link between growth and ageing rates under natural conditions.
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In total of 504 Lohmann Brown hens were used to study the influence of the initial BW of the birds and the crude protein (CP) and fat content of the diet on performance and egg quality traits from 22 to 49 weeks of age. The experiment was completely randomized with 8 treatments arranged factorially with 2 initial BW (1,726 vs. 1,987g) and 4 diets with similar AMEn (2,750 kcal AMEn/ kg) and indispensable (lys, Met+Cys, Thr, and Trp) amino acid contents.
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In pressure irrigation-water distribution networks, pressure regulating devices for controlling the discharged flow rate by irrigation units are needed due to the variability of flow rate. In addition, applied water volume is used controlled operating the valve during a calculated time interval, and assuming constant flow rate. In general, a pressure regulating valve PRV is the commonly used pressure regulating device in a hydrant, which, also, executes the open and close function. A hydrant feeds several irrigation units, requiring a wide range in flow rate. In addition, some flow meters are also available, one as a component of the hydrant and the rest are placed downstream. Every land owner has one flow meter for each group of field plots downstream the hydrant. Its lecture could be used for refining the water balance but its accuracy must be taken into account. Ideal PRV performance would maintain a constant downstream pressure. However, the true performance depends on both upstream pressure and the discharged flow rate. The objective of this work is to asses the influence of the performance on the applied volume during the whole irrigation events in a year. The results of the study have been obtained introducing the flow rate into a PRV model. Variations on flow rate are simulated by taking into account the consequences of variations on climate conditions and also decisions in irrigation operation, such us duration and frequency application. The model comprises continuity, dynamic and energy equations of the components of the PRV.
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We present and validate a test able to provide reliable body sway measurements in air pistol shooting, without the use of a gun. 46 senior male pistol shooters who participated in Spanish air pistol championships participated in the study. Body sway data of two static bipodal balance tests have been compared: during the first test, shooting was simulated by use of a dumbbell, while during the second test the shooters own pistol was used. Both tests were performed the day previous to the competition, during the official training time and at the training stands to simulate competition conditions. The participants performance was determined as the total score of 60 shots at competition. Apart from the commonly used variables that refer to movements of the shooters centre of pressure (COP), such as COP displacements on the X and Y axes, maximum and average COP velocities and total COP area, the present analysis also included variables that provide information regarding the axes of the COP ellipse (length and angle in respect to X). A strong statistically significant correlation between the two tests was found (with an interclass correlation varying between 0.59 and 0.92). A statistically significant inverse linear correlation was also found between performance and COP movements. The study concludes that dumbbell tests are perfectly valid for measuring body sway by simulating pistol shooting.
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Soccer participation worldwide is increasing and every club try to discover new talents. It is well know that there is an important correlation between body composition (BC) and talent detection (TD) and when coaches and selectors choose players, they tend to choose them with optimum BC.
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We hypothesize that pullets could respond similarly, independent of feed form, to the feeding of diets based on corn or wheat supplemented with adequate NSP enzymes. Also, pullets would quickly adapt their gastrointestinal tract and modify productive performance accordingly, when switched from crumbles to mash feeds. The aim of this research was to evaluate the effects of feeding crumbles for different periods of time, followed by feeding mash to 17 wk of age, on performance, gastrointestinal tract development, and body measurements of brown-egg laying pullets fed diets based on corn or wheat.
Alternative splicing, muscle calcium sensitivity, and the modulation of dragonfly flight performance
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Calcium sensitivity of myosin cross-bridge activation in striated muscles commonly varies during ontogeny and in response to alterations in muscle usage, but the consequences for whole-organism physiology are not well known. Here we show that the relative abundances of alternatively spliced transcripts of the calcium regulatory protein troponin T (TnT) vary widely in flight muscle of Libellula pulchella dragonflies, and that the mixture of TnT splice variants explains significant portions of the variation in muscle calcium sensitivity, wing-beat frequency, and an index of aerodynamic power output during free flight. Two size-distinguishable morphs differ in their maturational pattern of TnT splicing, yet they show the same relationship between TnT transcript mixture and calcium sensitivity and between calcium sensitivity and aerodynamic power output. This consistency of effect in different developmental and physiological contexts strengthens the hypothesis that TnT isoform variation modulates muscle calcium sensitivity and whole-organism locomotor performance. Modulating muscle power output appears to provide the ecologically important ability to operate at different points along a tradeoff between performance and energetic cost.