69 research outputs found
Efecto del entrenamiento de la potencia sobre la velocidad de lanzamiento en balonmano
Capacidad de realizar esprints repetidos en jugadores profesionales de fútbol vs. Fútbol sala
Objetivo: Investigar los cambios producidos ante acciones de esprines repetidos (20+20 metros con cambio de dirección ), el CMJ, la respuesta metabólica (lactato) , y la relación entre estas variables y la fuerza y resistencia en jugadores profesionales de fútbol y fútbol sala. Métodos: Jugadores profesionales (n=30, doce de fútbol sala y veinte de fútbol) completaron tres sesiones de evaluación; VO2max en tapiz rodante, el salto CMJ y la RM en sentadilla completa y finalmente, se realizó el test de RSA (6 x 40 (20+20)). Resultados: Se obtuvieron valores similares de fuerza en sentadilla, en CMJ, de LAC después de la prueba RSA y de VO2max ( 95,12 kg vs 94,73 kg ; 34,5 cm vs 35,9 cm ; 13,65 mmol vs 14,33 mmol ; 62,78 ml·kg·min-1 vs . 62,95 ml·kg·min-1 fútbol vs. fútbol sala, respectivamente). Se obtuvieron diferencias significativas cuando se analizó la pérdida de rendimiento en velocidad (total y entre los tres primeros y tres últimos bloques de esprines) y en salto (2,67% vs 4,4%**; 1,28% vs 2,1%*; 2,88% vs 6,1%**; 9,71% vs 14,3%* de fútbol vs. fútbol sala, respectivamente). Conclusiones: Ambos deportes presentan diferencias significativas en las pérdidas de rendimiento en velocidad y salto a pesar de tener valores similares de fuerza, de VO2max, de lactato tras RSA y de CMJ. Podría atribuirse a los esfuerzos propios de cada deporte y puede sugerir que debería incrementarse el volumen de entrenamiento orientado a la capacidad de realizar esfuerzos repetidos frente a otro tipo de objetivo como la mejora de la capacidad aeróbica, sobre todo a nivel profesional.To investigate the changes through repeated explosive effort sequences (20+20-m sprint with change of direction), jumping, metabolic response (lactate), as well as the relationship between these variables and fitness qualities (strength and endurance) in professional futsal and soccer players. Methods: Male players (n =30, Twelve futsal and twenty soccer players) completed three testing sessions. In the first session was measured VO2max on a motorized treadmill. In the second session was measured counter movement jump (CMJ) and full squat RM in Smith Machine. Finally, in the third session six repeated-explosive effort sequences (RES) was performed. Results: Similar values of lower limbs strength, CMJ height, LAC after RSA test and VO2max (95,12 vs. 94,73; 34,5 vs. 35,9; 13,65 vs. 14,33; 62,78 vs. 62,95 soccer vs. futsal respectively) and significant differences when are analysed the loss of performance in velocity (total and between three first and three last) and vertical jump height (2,67 vs. 4,4**; 1,28 vs. 2,1*; 2,88 vs. 6,1**; 9,71 vs. 14,3* soccer vs. futsal respectively). Conclusions: Professional futsal and soccer obtain significant differences in speed and vertical jump height (CMJ) loss despite having similar values in squat, oxygen consumption, lactate after RSA test and CMJ height. Issue that could be attributed to the characteristics of the sport. This suggests that the volume should be increased oriented ability to perform repeated sprint actions over other type of training aimed at improving aerobic capacity especially at professional level.peerReviewe
Load that maximizes power output in countermovement jump
Introduction:
One of the main problems faced by strength and conditioning coaches is the issue of how to objectively quantify and monitor the actual training load undertaken by athletes in order to maximize performance. It is well known that performance of explosive sports activities is largely determined by mechanical power.
Objective:
This study analysed the height at which maximal power output is generated and the corresponding load with which is achieved in a group of male-trained track and field athletes in the test of countermovement jump (CMJ) with extra loads (CMJEL).
Methods:
Fifty national level male athletes in sprinting and jumping performed a CMJ test with increasing loads up to a height of 16 cm. The relative load that maximized the mechanical power output (Pmax) was determined using a force platform and lineal encoder synchronization and estimating the power by peak power, average power and flight time in CMJ.
Results:
The load at which the power output no longer existed was at a height of 19.9 ± 2.35, referring to a 99.1 ± 1% of the maximum power output. The load that maximizes power output in all cases has been the load with which an athlete jump a height of approximately 20 cm.
Conclusion:
These results highlight the importance of considering the height achieved in CMJ with extra load instead of power because maximum power is always attained with the same height. We advise for the preferential use of the height achieved in CMJEL test, since it seems to be a valid indicative of an individual's actual neuromuscular potential providing a valid information for coaches and trainers when assessing the performance status of our athletes and to quantify and monitor training loads, measuring only the height of the jump in the exercise of CMJEL.Actividad Física y Deport
Differentiating Endurance- and Speed-Adapted Types of Elite and World Class Milers According to Biomechanical, Pacing and Perceptual Responses during a Sprint Interval Session
The aim was to compare pacing, biomechanical and perceptual responses between elite speed- and endurance-adapted milers during a sprint interval training session (SIT). Twenty elite and world-class middle-distance runners (male: n = 16, female: n = 4; 24.95 ± 5.18 years; 60.89 ± 7 kg) were classified as either speed- or endurance-adapted milers according to their recent per-formances at 800 m or longer races than 1500 m (10 subjects per group). Participants performed 10 repetitions of 100 m sprints with 2 min of active recovery between each, and performance, per-ceptual and biomechanical responses were collected. The difference between accumulated times of the last and the first five repetitions was higher in speed-adapted milers (ES = 1.07) displaying a more positive pacing strategy. A higher coefficient of variation (CV%) was displayed across the session by speed-adapted milers in average repetition time, contact time, and affective valence (ES ≥ 1.15). Speed-adapted milers experienced lower rates of valence after the 4th repetition excepting at the 8th repetition (ES ≥ 0.99). Speed-adapted milers may need to display a more positive pacing profile than endurance-adapted milers and, therefore, would experience lower levels of affective valence and a more rapid increase of ground contact time during a SIT
Differences between adjusted vs. non- adjusted loads in velocity-based training: consequences for strength training control and programming
Strength and conditioning specialists commonly deal with the quantification and
selection the setting of protocols regarding resistance training intensities. Although
the one repetition maximum (1RM) method has been widely used to prescribe exercise
intensity, the velocity-based training (VBT) method may enable a more optimal tool
for better monitoring and planning of resistance training (RT) programs. The aim of
this study was to compare the effects of two RT programs only differing in the training
load prescription strategy (adjusting or not daily via VBT) with loads from 50 to 80%
1RM on 1RM, countermovement (CMJ) and sprint. Twenty-four male students with
previous experience in RT were randomly assigned to two groups: adjusted loads (AL)
(nD13) and non-adjusted loads (NAL) (nD11) and carried out an 8-week (16 sessions)
RT program. The performance assessment pre- and post-training program included
estimated 1RM and full load-velocity profile in the squat exercise; countermovement
jump (CMJ); and 20-m sprint (T20). Relative intensity (RI) and mean propulsive
velocity attained during each training session (Vsession) was monitored. Subjects in the
NAL group trained at a significantly faster Vsession than those in AL (p < 0.001) (0.88 -
0.91 vs. 0.67- 0.68 m/s, with a 15% RM gap between groups for the last sessions), and
did not achieve the maximum programmed intensity (80% RM). Significant differences
were detected in sessions 3- 4, showing differences between programmed and performed
Vsession and lower RI and velocity loss (VL) for the NAL compared to the AL group
(p < 0.05). Although both groups improved 1RM, CMJ and T20, NAL experienced
greater and significant changes than AL (28.90 vs.12.70%, 16.10 vs. 7.90% and -1.99 vs.
- 0.95%, respectively). Load adjustment based on movement velocity is a useful way to
control for highly individualised responses to training and improve the implementation
of RT programs
Wideband 67-116 GHz cryogenic receiver development for ALMA Band 2
The Atacama Large Millimeter/sub-millimeter Array (ALMA) is already
revolutionising our understanding of the Universe. However, ALMA is not yet
equipped with all of its originally planned receiver bands, which will allow it
to observe over the full range of frequencies from 35-950 GHz accessible
through the Earth's atmosphere. In particular Band 2 (67-90 GHz) has not yet
been approved for construction. Recent technological developments in cryogenic
monolithic microwave integrated circuit (MMIC) high electron mobility
transistor (HEMT) amplifier and orthomode transducer (OMT) design provide an
opportunity to extend the originally planned on-sky bandwidth, combining ALMA
Bands 2 and 3 into one receiver cartridge covering 67-116 GHz.
The IF band definition for the ALMA project took place two decades ago, when
8 GHz of on-sky bandwidth per polarisation channel was an ambitious goal. The
new receiver design we present here allows the opportunity to expand ALMA's
wideband capabilities, anticipating future upgrades across the entire
observatory. Expanding ALMA's instantaneous bandwidth is a high priority, and
provides a number of observational advantages, including lower noise in
continuum observations, the ability to probe larger portions of an astronomical
spectrum for, e.g., widely spaced molecular transitions, and the ability to
scan efficiently in frequency space to perform surveys where the redshift or
chemical complexity of the object is not known a priori. Wider IF bandwidth
also reduces uncertainties in calibration and continuum subtraction that might
otherwise compromise science objectives.
Here we provide an overview of the component development and overall design
for this wideband 67-116 GHz cryogenic receiver cartridge, designed to operate
from the Band 2 receiver cartridge slot in the current ALMA front end receiver
cryostat.Comment: 8 pages, proceedings from the 8th ESA Workshop on Millimetre-Wave
Technology and Applications
(https://atpi.eventsair.com/QuickEventWebsitePortal/millimetre-wave/mm-wave
Gongolarones as antiamoeboid chemical scaffold
Free Living Amoeba (FLA) infections caused by Acanthamoeba genus include chronic nervous system diseases such as Granulomatous Amoebic Encephalitis (GAE), or a severe eye infection known as Acanthamoeba keratitis (AK). Current studies focused on therapy against these diseases are aiming to find novel compounds with amoebicidal activity and low toxicity to human tissues. Brown algae, such as Gongolaria abies-marina (previously known as Cystoseira abies-marina, S.G. Gmelin), presents bioactive molecules of interest, including some with antiprotozoal activity. In this study, six meroterpenoids were isolated and purified from the species Gongolaria abies-marina. Gongolarones A (1), B (2) and C (3) were identified as new compounds. Additionally, cystomexicone B (4), 1′-methoxyamentadione (5) and 6Z-1′-methoxyamentadione (6) were isolated. All compounds exhibited amoebicidal activity against Acanthamoeba castellanii Neff, A. polyphaga and A. griffini strains. Gongolarones A (1) and C (3) showed the lowest IC50 values against the two stages of these amoebae (trophozoite and cyst). Structure-activity relationship revealed that the cyclization by ether formation from C-12 to C-15 of 1, and the isomerization Δ2 t to Δ3 t of 3, increased the antiamoeboid activity of both compounds. Furthermore, gongolarones A (1) and C (3) triggered chromatin condensation, mitochondrial malfunction, oxidative stress, and disorganization of the tubulin-actin cytoskeleton in treated trophozoites. Moreover, transmission electron microscopy (TEM) images analysis revealed that compounds 1 and 3 induced autophagy process and inhibited the encystation process. All those results suggest that both compounds could induce programmed cell death (PCD) in Acanthamoeba.This study was supported funded by projects PID2019-109476RB-C21 (BIOALGRI) (Spanish Ministry of Science), Madrid, Spain; Fundación CajaCanarias–Fundación Bancaria “La Caixa” (2019SP52). Red de Investigación Cooperativa en Enfermedades Tropicales (RICET), Spain (project no. RD16/0027/0001 of the programe of Redes Temáticas de Investigación Cooperativa, FIS). Consorcio Centro de Investigación Biomédica en Red (CIBER), Área de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, 28029, Madrid, Spain (CB21/13/00100). Project No. 21/0587 funded by the Cabildo de Tenerife, Tenerife innova, Marco Estratégico de Desarrollo Insular (MEDI) and Fondo de Desarrollo de Canarias (FDCAN). Project number ProID2021010118 funded by Agencia Canaria de Investigación, Innovación y Sociedad de la Información (ACIISI). RLRE was funded by a grant from ACIISI cofunded by Fondo Social Europeo (FSE) and FEDER, (TESIS2020010117). MOM was supported by the Programa de Apoyos para la Superación del Personal Académico de la UNAM (PASPA 2021) for carrying out the research stay between the Universidad de La Laguna and la Facultad de Estudios Superiores Iztacala.Peer reviewe
Assessing the Diversity and Specificity of Two Freshwater Viral Communities through Metagenomics
Transitions between saline and fresh waters have been shown to be infrequent for microorganisms. Based on host-specific interactions, the presence of specific clades among hosts suggests the existence of freshwater-specific viral clades. Yet, little is known about the composition and diversity of the temperate freshwater viral communities, and even if freshwater lakes and marine waters harbor distinct clades for particular viral sub-families, this distinction remains to be demonstrated on a community scale
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Cause of Death and Predictors of All-Cause Mortality in Anticoagulated Patients With Nonvalvular Atrial Fibrillation : Data From ROCKET AF
M. Kaste on työryhmän ROCKET AF Steering Comm jäsen.Background-Atrial fibrillation is associated with higher mortality. Identification of causes of death and contemporary risk factors for all-cause mortality may guide interventions. Methods and Results-In the Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared with Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation (ROCKET AF) study, patients with nonvalvular atrial fibrillation were randomized to rivaroxaban or dose-adjusted warfarin. Cox proportional hazards regression with backward elimination identified factors at randomization that were independently associated with all-cause mortality in the 14 171 participants in the intention-to-treat population. The median age was 73 years, and the mean CHADS(2) score was 3.5. Over 1.9 years of median follow-up, 1214 (8.6%) patients died. Kaplan-Meier mortality rates were 4.2% at 1 year and 8.9% at 2 years. The majority of classified deaths (1081) were cardiovascular (72%), whereas only 6% were nonhemorrhagic stroke or systemic embolism. No significant difference in all-cause mortality was observed between the rivaroxaban and warfarin arms (P=0.15). Heart failure (hazard ratio 1.51, 95% CI 1.33-1.70, P= 75 years (hazard ratio 1.69, 95% CI 1.51-1.90, P Conclusions-In a large population of patients anticoagulated for nonvalvular atrial fibrillation, approximate to 7 in 10 deaths were cardiovascular, whereasPeer reviewe
Clinical and organizational factors associated with mortality during the peak of first COVID-19 wave: the global UNITE-COVID study
Purpose: To accommodate the unprecedented number of critically ill patients with pneumonia caused by coronavirus disease 2019 (COVID-19) expansion of the capacity of intensive care unit (ICU) to clinical areas not previously used for critical care was necessary. We describe the global burden of COVID-19 admissions and the clinical and organizational characteristics associated with outcomes in critically ill COVID-19 patients. Methods: Multicenter, international, point prevalence study, including adult patients with SARS-CoV-2 infection confirmed by polymerase chain reaction (PCR) and a diagnosis of COVID-19 admitted to ICU between February 15th and May 15th, 2020. Results: 4994 patients from 280 ICUs in 46 countries were included. Included ICUs increased their total capacity from 4931 to 7630 beds, deploying personnel from other areas. Overall, 1986 (39.8%) patients were admitted to surge capacity beds. Invasive ventilation at admission was present in 2325 (46.5%) patients and was required during ICU stay in 85.8% of patients. 60-day mortality was 33.9% (IQR across units: 20%–50%) and ICU mortality 32.7%. Older age, invasive mechanical ventilation, and acute kidney injury (AKI) were associated with increased mortality. These associations were also confirmed specifically in mechanically ventilated patients. Admission to surge capacity beds was not associated with mortality, even after controlling for other factors. Conclusions: ICUs responded to the increase in COVID-19 patients by increasing bed availability and staff, admitting up to 40% of patients in surge capacity beds. Although mortality in this population was high, admission to a surge capacity bed was not associated with increased mortality. Older age, invasive mechanical ventilation, and AKI were identified as the strongest predictors of mortality
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