Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Front Psychol ; 13: 873474, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35734458

RESUMEN

Expert athletes are determined to make faster and better decisions, as revealed in several simple heuristic studies using verbal reports or micro-movement responses. However, heuristic decision-making experiments that require motor responses, also being considered as the embodied-choice experiments, are still underrepresented. Furthermore, it is less understood how decision time and confidence depend on the type of embodied choices players make. To scrutinize the decision-making processes (i.e., decision time, decision confidence), this study investigated the embodied choices of male athletes with different expertise in a close-to-real-life environment; 22 elite (M age = 17.59 yrs., SD = 3.67), and 22 amateur (M age = 20.71 yrs., SD = 8.54) team handball players performed a sport-specific embodied-choice test. Attack sequences (n = 32) were shown to the players, who had to choose between four provided options by giving a respective sport-specific motor response. We analyzed the frequencies of specific choices and the best choice, as well as the respective decision time and decision confidence. Elite and amateur players differed in the frequencies of specific choices (i.e., forward/tackling; passive blocking), and elite players made the best choice more often. Slower decision times of elite players were revealed in specific choices and in best choices, the confidence of decisions was rated equally high by both player groups. Indications are provided that elite players make better choices rather slower, instead of faster. We suppose this is due to specific sensorimotor interactions and speed-accuracy-tradeoffs in favor of accuracy in elite players. Our findings extend expert decision-making research by using an embodied-choice paradigm, highlighting considerations of decision time and confidence in future experiments.

2.
Front Psychol ; 13: 854208, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35496175

RESUMEN

Athletic features distinguishing experts from non-experts in team sports are relevant for performance analyses, talent identification and successful training. In this respect, perceptual-cognitive factors like decision making have been proposed to be important predictor of talent but, however, assessing decision making in team sports remains a challenging endeavor. In particular, it is now known that decisions expressed by verbal reports or micro-movements in the laboratory differ from those actually made in on-field situations in play. To address this point, our study compared elite and amateur players' decision-making behavior in a near-game test environment including sport-specific sensorimotor responses. Team-handball players (N = 44) were asked to respond as quickly as possible to representative, temporally occluded attack sequences in a team-handball specific defense environment on a contact plate system. Specifically, participants had to choose and perform the most appropriate out of four prespecified, defense response actions. The frequency of responses and decision time were used as dependent variables representing decision-making behavior. We found that elite players responded significantly more often with offensive responses (p < 0.05, odds ratios: 2.76-3.00) in left-handed attack sequences. Decision time decreased with increasing visual information, but no expertise effect was found. We suppose that expertise-related knowledge and processing of kinematic information led to distinct decision-making behavior between elite and amateur players, evoked in a domain-specific and near-game test setting. Results also indicate that the quality of a decision might be of higher relevance than the required time to decide. Findings illustrate application opportunities in the context of performance analyses and talent identification processes.

3.
Int J Sports Physiol Perform ; 17(6): 901-907, 2022 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-35235906

RESUMEN

PURPOSE: In elite team handball, talent identification and selection of the best young players is a fundamental process in several national federations and clubs; however, literature addressing the specific game-based performance in team handball is almost nonexistent. Consequently, the aim of the study was to assess and compare the team-handball-specific game-based performance of elite male team handball players of different ages. METHODS: Twelve under-23, 10 under-19, 10 under-17, and 10 under-15 elite male players performed the team-handball game-based performance test. During testing, oxygen uptake, heart rate, sprinting time in defense, offense, fast breaks, and fast retreats, as well as ball velocity and jump height in the jump shot, were measured. RESULTS: Significant differences (P < .05) between under-23, under-19, under-17, and under-15 players were found for absolute peak oxygen uptake, defense, offense and fast break time, ball velocity, and jump height in the game-based performance test, as well as in body weight and height. CONCLUSION: The results revealed that with increasing age, elite male team handball players are heavier and taller (body weight and height); faster (team-handball offense, defense, and fast break); jump higher and throw faster (in the team-handball jump shot); and perform better aerobically (absolute peak oxygen uptake). The better performance in the under-23 and under-19 players compared with male adult players competing in a lower National Federation league (not on top-elite level) demonstrates that highly specific game-based physical performance determines the potential for developing young male team handball players for competition at the top level.


Asunto(s)
Rendimiento Atlético , Adolescente , Adulto , Rendimiento Atlético/fisiología , Estatura , Peso Corporal , Prueba de Esfuerzo/métodos , Humanos , Masculino , Oxígeno
4.
Am J Geriatr Psychiatry ; 27(4): 426-445, 2019 04.
Artículo en Inglés | MEDLINE | ID: mdl-30642650

RESUMEN

OBJECTIVE: The aim of this study was to estimate the efficacy of technology-based interventions for informal caregivers of people with dementia (PWD). METHODS: PubMed, PsycINFO, and Cochrane Library databases were searched in August 2018, with no restrictions in language or publication date. Two independent reviewers identified 33 eligible randomized controlled trials (RCTs) conducting a technology-based intervention for informal carers of PWD. Meta-analyses for the outcome measures caregiver depression and caregiver burden were conducted with subgroup analyses according to mode of delivery (telephone, computer/web-based, combined interventions). To assess methodologic quality, the Cochrane risk-of-bias assessment was rated. RESULTS: Meta-analyses revealed a small but significant postintervention effect of technology-based interventions for caregiver depression and caregiver burden. Combined interventions showed the strongest effects. CONCLUSION: Technology-based interventions have the potential to support informal caregivers of PWD. Because of advantages such as high flexibility and availability, technology-based interventions provide a promising alternative compared with "traditional services," e.g., those for people living in rural areas. More high-quality RCTs for specific caregiver groups are needed.


Asunto(s)
Cuidadores/psicología , Costo de Enfermedad , Demencia/enfermería , Ensayos Clínicos Controlados Aleatorios como Asunto/estadística & datos numéricos , Telemedicina/estadística & datos numéricos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Depresión/terapia , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven
5.
J Strength Cond Res ; 30(10): 2794-801, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-24942169

RESUMEN

Wagner, H, Orwat, M, Hinz, M, Pfusterschmied, J, Bacharach, DW, von Duvillard, SP, and Müller, E. Testing game-based performance in team-handball. J Strength Cond Res 30(10): 2794-2801, 2016-Team-handball is a fast paced game of defensive and offensive action that includes specific movements of jumping, passing, throwing, checking, and screening. To date and to the best of our knowledge, a game-based performance test (GBPT) for team-handball does not exist. Therefore, the aim of this study was to develop and validate such a test. Seventeen experienced team-handball players performed 2 GBPTs separated by 7 days between each test, an incremental treadmill running test, and a team-handball test game (TG) (2 × 20 minutes). Peak oxygen uptake (V[Combining Dot Above]O2peak), blood lactate concentration (BLC), heart rate (HR), sprinting time, time of offensive and defensive actions as well as running intensities, ball velocity, and jump height were measured in the game-based test. Reliability of the tests was calculated using an intraclass correlation coefficient (ICC). Additionally, we measured V[Combining Dot Above]O2peak in the incremental treadmill running test and BLC, HR, and running intensities in the team-handball TG to determine the validity of the GBPT. For the test-retest reliability, we found an ICC >0.70 for the peak BLC and HR, mean offense and defense time, as well as ball velocity that yielded an ICC >0.90 for the V[Combining Dot Above]O2peak in the GBPT. Percent walking and standing constituted 73% of total time. Moderate (18%) and high (9%) intensity running in the GBPT was similar to the team-handball TG. Our results indicated that the GBPT is a valid and reliable test to analyze team-handball performance (physiological and biomechanical variables) under conditions similar to competition.


Asunto(s)
Rendimiento Atlético/fisiología , Prueba de Esfuerzo/métodos , Carrera/fisiología , Deportes/fisiología , Adolescente , Adulto , Frecuencia Cardíaca/fisiología , Humanos , Ácido Láctico/sangre , Masculino , Consumo de Oxígeno/fisiología , Reproducibilidad de los Resultados , Adulto Joven
6.
Ann Hepatol ; 12(1): 92-9, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23293199

RESUMEN

BACKGROUND: Combination therapy with terlipressin and albumin substitution is considered a widely accepted treatment regimen for patients with hepatorenal syndrome (HRS). However, only half of the patients respond to treatment and to date albumin substitution and terlipressin therapy are among the most expensive medical treatments available for patients with liver diseases. Thus, we aimed to identify clinical and etiological parameters to predict treatment response and overall mortality in patients with HRS. MATERIAL AND METHODS: We retrospectively evaluated 21 patients, 13 male/8 female, aged 43-72 years with HRS. Four patients were transplanted after following combination treatment. Terlipressin was administered by continuous intravenous perfusion (2-6 mg/d) and albumin drips (50 mg) were given daily. Treatment response was defined by a decrease in serum creatinine level to ≤ 1.5 mg/dL or by a ≥ 50% reduction of the baseline concentration. RESULTS: 57% of the patients responded to treatment, which was associated with improved survival at day 60, compared to non-responders. However, the overall mortality was not different between the two groups. Median age of 63 years was a significant negative predictor for therapy response. High baseline urinary sodium levels were of prognostic value for survival. The Model of End stage Liver Disease score (MELD score) did not correlate with therapy response. CONCLUSION: In conclusion high age is a predictor of non-response. Low urinary sodium before treatment is associated with poor survival. Terlipressin and albumin co-treatment is associated with increased two-months survival rate. This seemingly moderate extension in survival rate can, however, be decisive for obtaining liver transplantation.


Asunto(s)
Albúminas/uso terapéutico , Síndrome Hepatorrenal , Cirrosis Hepática , Lipresina/análogos & derivados , Sodio/orina , Vasoconstrictores/uso terapéutico , Adulto , Factores de Edad , Anciano , Creatinina/sangre , Quimioterapia Combinada , Femenino , Síndrome Hepatorrenal/tratamiento farmacológico , Síndrome Hepatorrenal/mortalidad , Síndrome Hepatorrenal/orina , Humanos , Cirrosis Hepática/mortalidad , Cirrosis Hepática/orina , Lipresina/uso terapéutico , Masculino , Persona de Mediana Edad , Pronóstico , Estudios Retrospectivos , Índice de Severidad de la Enfermedad , Terlipresina , Resultado del Tratamiento
7.
J Virol ; 79(16): 10467-77, 2005 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-16051839

RESUMEN

Entry of most paramyxoviruses is accomplished by separate attachment and fusion proteins that function in a cooperative manner. Because of this close interdependence, it was not possible with most paramyxoviruses to replace either of the two protagonists by envelope glycoproteins from related paramyxoviruses. By using reverse genetics of Sendai virus (SeV), we demonstrate that chimeric respiratory syncytial virus (RSV) fusion proteins containing either the cytoplasmic domain of the SeV fusion protein or in addition the transmembrane domain were efficiently incorporated into SeV particles provided the homotypic SeV-F was deleted. In the presence of SeV-F, the chimeric glycoproteins were incorporated with significantly lower efficiency, indicating that determinants in the SeV-F ectodomain exist that contribute to glycoprotein uptake. Recombinant SeV in which the homotypic fusion protein was replaced with chimeric RSV fusion protein replicated in a trypsin-independent manner and was neutralized by antibodies directed to RSV-F. However, replication of this virus also relied on the hemagglutinin-neuraminidase (HN) as pretreatment of cells with neuraminidase significantly reduced the infection rate. Finally, recombinant SeV was generated with chimeric RSV-F as the only envelope glycoprotein. This virus was not neutralized by antibodies to SeV and did not use sialic acids for attachment. It replicated more slowly than hybrid virus containing HN and produced lower virus titers. Thus, on the one hand RSV-F can mediate infection in an autonomous way while on the other hand it accepts support by a heterologous attachment protein.


Asunto(s)
Proteína HN/fisiología , Proteínas Recombinantes de Fusión/fisiología , Virus Sincitiales Respiratorios/fisiología , Virus Sendai/genética , Proteínas Virales de Fusión/fisiología , Animales , Anticuerpos Antivirales/inmunología , Chlorocebus aethiops , Células HeLa , Humanos , Recombinación Genética , Virus Sendai/fisiología , Tripsina/farmacología , Células Vero , Replicación Viral
8.
J Biol Chem ; 279(9): 7840-9, 2004 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-14681219

RESUMEN

Type I phosphatidylinositol 4-phosphate 5-kinase (PIP5K) catalyzes the formation of the phospholipid, phosphatidylinositol 4,5-bisphosphate (PIP(2)), which is implicated in many cellular processes. The Rho GTPases, RhoA and Rac1, have been shown previously to activate PIP5K and to bind PIP5K. Three type I PIP5K isoforms (Ialpha,Ibeta, and Igamma) have been identified; however, it is unclear whether these isoforms are differentially or even sequentially regulated by Rho GTPases. Here we show that RhoA and Rac1, as well as Cdc42, but not the Ras-like GTPases, RalA and Rap1A, markedly stimulate PIP(2) synthesis by all three PIP5K isoforms expressed in human embryonic kidney 293 cells, both in vitro and in vivo. RhoA-stimulated PIP(2) synthesis by the PIP5K isoforms was mediated by the RhoA effector, Rho-kinase. Stimulation of PIP5K isoforms by Rac1 and Cdc42 was apparently independent of and additive with RhoA- and Rho-kinase, as shown by studies with C3 transferase and Rho-kinase mutants. RhoA, and to a lesser extent Rac1, but not Cdc42, interacted in a nucleotide-independent form with all three PIP5K isoforms. Binding of PIP5K isoforms to GTP-bound, but not GDP-bound, RhoA could be displaced by Rho-kinase, suggesting a direct and constitutive PIP5K-Rho GTPase binding, which, however, does not trigger PIP5K activation. In summary, our findings indicate that synthesis of PIP(2) by the three PIP5K isoforms is controlled by RhoA, acting via Rho-kinase, as well as Rac1 and Cdc42, implicating that regulation of PIP(2) synthesis has a central position in signaling by these three Rho GTPases.


Asunto(s)
Isoenzimas/metabolismo , Fosfotransferasas (Aceptor de Grupo Alcohol)/metabolismo , Proteína de Unión al GTP cdc42/farmacología , Proteína de Unión al GTP rac1/farmacología , Proteína de Unión al GTP rhoA/farmacología , Animales , Línea Celular , Embrión de Mamíferos , Activación Enzimática/efectos de los fármacos , Expresión Génica , Guanosina 5'-O-(3-Tiotrifosfato)/metabolismo , Guanosina Difosfato/metabolismo , Humanos , Péptidos y Proteínas de Señalización Intracelular , Riñón , Ratones , Mutagénesis , Fosfatidilinositol 4,5-Difosfato/biosíntesis , Fosfotransferasas (Aceptor de Grupo Alcohol)/genética , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Recombinantes de Fusión/metabolismo , Transfección , Proteína de Unión al GTP cdc42/genética , Proteína de Unión al GTP cdc42/metabolismo , Proteína de Unión al GTP rac1/genética , Proteína de Unión al GTP rac1/metabolismo , Quinasas Asociadas a rho , Proteína de Unión al GTP rhoA/genética , Proteína de Unión al GTP rhoA/metabolismo
9.
Physiol Plant ; 114(3): 414-421, 2002 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-12060264

RESUMEN

Rain-cracking of sweet cherry fruit has been related to water absorption through the fruit surface and large fruit has been reported to be more susceptible to cracking than small fruit. Therefore, the effect of fruit size on water conductance of the cuticular membrane (CM) of exocarp segments excised from cheek, suture or stylar end region of mature sweet cherry fruit (Prunus avium L. cv. Sam) was investigated. Segments consisting of epidermis, hypodermis and several layers of mesocarp cells were mounted in diffusion cells filled with deionized water. Mass loss due to transpiration was monitored gravimetrically during an 8-h incubation period (25 +/- 2 degrees C) over dry silica in the dark. Conductance was calculated from the amount of water transpired per unit surface area and time divided by the difference in water vapour concentration across the segment. For an average size cv. Sam sweet cherry CM conductance was 1.06 x 10-4, 0.91 x 10-4 and 2.09 x 10-4 m s-1 in cheek, suture and stylar end region, respectively. Fruit size had no significant effect on conductance in cheek or suture regions, but for the stylar end region conductance was positively related to fruit size. Stomatal density in the cheek, but not the suture or stylar end region increased as fruit size increased. The area of the stylar scar was positively related to fruit size. Conductance of the stylar scar averaged 37.6 +/- 4.0 x 10-4 m s-1 and was 54-fold higher than that of the CM between stomata in the cheek region (mean 0.69 x 10-4 m s-1). Conductance calculated on a whole fruit basis is estimated to increase by 108% as fruit size increases from 6 to 12 g. Increased conductance on a whole fruit basis may be attributed to increased fruit surface area and increased conductance per unit fruit surface area, particularly in the stylar end region.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...