785 research outputs found

    Dynamically Generated Resonances in the Chiral Unitary Approach to Meson Baryon Interaction

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    In this talk we report on the use of a chiral unitary approach for the interaction of the octets of meson and baryon and the octet of mesons with the decuplet of baryons. Two octets of Jπ=1/2J^{\pi}=1/2^- baryon states and a singlet are generated dynamically in the first case, resulting in the case of strangeness S=1S=-1 in two poles of the scattering matrix close to the nominal Λ(1405)\Lambda(1405) resonance. In the second case many resonances are also generated, among them an exotic baryon with S=1 corresponding to a ΔK\Delta K resonance. We make suggestions of experiments which could show evidence for the existence of these states.Comment: Talk at the MENU04 Symposium, Beijing, September 200

    Cortical and trabecular bone at the radius and tibia in male and female adolescents with Down syndrome:a peripheral quantitative computed tomography (pQCT) study

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    Abstract Summary We aimed to describe the structure and strength of the tibia and radius of adolescents with Down syndrome. We observed that despite higher levels of volumetric bone mineral density in determined skeletal sites, they are at higher risk of developing osteoporotic fractures in the future due to their lower bone strength indexes. Introduction The aims of the study were to describe the cortical and trabecular volumetric bone mineral density (vBMD), bone mineral content (BMC), area, and bone strength in adolescents with Down syndrome (DS) and to compare them with adolescents without disabilities. Methods Thirty adolescents (11 girls) with DS and 28 without disabilities (10 girls) participated in the study. Peripheral quantitative computed tomography measurements were taken at proximal and distal sites of the tibia and radius. Values of total, trabecular, and cortical BMC; vBMD; and area were obtained of each scan. Cortical thickness and endosteal and periosteal circumferences were also measured, and different bone strength indexes were calculated. Student's t tests were applied between groups. Results The DS group showed greater vBMD at distal radius, BMC at proximal radius, and total and cortical vBMD at proximal tibia. The non-DS group showed higher total and trabecular area at the distal radius and total, cortical, and trabecular BMC and area at distal tibia. Higher values of periosteal and endosteal circumference and bone strength were also found in non-DS group. Conclusions From these results, it can be believed that even with higher vBMD in determined skeletal sites, adolescents with DS are at higher risk of suffering bone fractures due to an increased fragility by lower resistance to load bending or torsion

    El Taiji Quan y Qigong en la promoción de la salud y en el afrontamiento del estrés

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    Exercise and physical activity improves psychological and physical health in users. However, rarely it is examined the quantitative effects of Tai Chi in cardiovascular, locomotor, mental, cognitive and psychosocial systems among others. The effects on stress, blood pressure and cardiopulmonary risk, breathing capacity and its impact on diseases of this system, balance, muscle elasticity on the locomotor system, anxiety, depression and disorders of systematically reviewed mood in both eastern and western populations. 53 studies were considered and 5875 subject were studied. Tai Chi appears to be associated with improvements in the vast majority of systems that analyze the authors but stresses the psychological well-being, including reducing stress, anxiety, depression and improvements to musculoskeletal level. Conclusion: these are limited due to variation in design, the various results and incorrect quality controls. Randomized trials are necessary to ensure the evidence.El ejercicio y la actividad física mejoran la salud psicológica y física de los usuarios. Sin embargo, pocas veces se han examinado los efectos cuantitativos del Tai Chi Chuan en los sistemas cardiovascular, locomotor, mental, cognitivo y psicosocial entre otros. Se revisaron sistemáticamente los efectos sobre el estrés, la presión arterial y el riesgo cardiopulmonar, la capacidad respiratoria y su incidencia sobre patologías de este sistema, el equilibrio, la elasticidad muscular sobre el sistema locomotor, la ansiedad, la depresión y trastornos del estado de ánimo en las poblaciones orientales y occidentales. Se han considerado 53 estudios con una muestra de 5.875 sujetos y 13 meta análisis. Hay que resaltar que el Tai Chi parece estar asociado con mejoras en la gran mayoría de los sistemas que analizan los autores pero destaca el bienestar psicológico, incluyendo la reducción del estrés, ansiedad, depresión así como las mejoras a nivel musculo esquelético. Las conclusiones definitivas son limitadas debido a la variación en los diseños, los resultados diversos y los controles incorrectos de calidad. Son necesarios más ensayos aleatorios que garanticen la evidencia

    Metabolomic evaluation of pulsed electric field-induced stress on potato tissue

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    Metabolite profiling was used to characterize stress responses of potato tissue subjected to reversible electroporation, providing insights on how potato tissue responds to a physical stimulus such as pulsed electric fields (PEF), which is an artificial stress. Wounded potato tissue was subjected to field strengths ranging from 200 to 400 V/cm, with a single rectangular pulse of 1 ms. Electroporation was demonstrated by propidium iodide staining of the cell nucleae. Metabolic profiling of data obtained through GC/TOF-MS and UPLC/TOF-MS complemented with orthogonal projections to latent structures clustering analysis showed that 24 h after the application of PEF, potato metabolism shows PEF-specific responses characterized by the changes in the hexose pool that may involve starch and ascorbic acid degradation.The Royal Physiographic Society in Lund, SwedenPortuguese Foundation of Science (FCT), PortugalDepartment of Cell and Organism Biology, Lund Universit

    Pulsed electric field-induced cell permeabilisation of potato tissue lead to sustained metabolic changes

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    Metabolite profiling was used to characterize stress responses of potato tissue subjected to reversible electroporation, providing insights on how potato tissue responds to a physical stimulus such as pulsed electric fields (PEF), which is an artificial stress. Wounded potato tissue was subjected to field strengths ranging from 200 to 400 V/cm, with a single rectangular pulse of 1 ms. Electroporation was demonstrated by propidium iodide staining of the cells nucleae. Metabolic profiling of data obtained through GC/TOF-MS complemented with orthogonal projections to latent structures (OPLS) clustering analysis showed that 24 h after the application of PEF, potato metabolism shows PEF-specific responses characterized by the changes in the hexose pool that may involve starch and ascorbic acid degradation

    Bone strength index at Tibia and standing broad jump in adolescent swimmers

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    Measurement of broad jump is a simple, economical and non-invasive test that provides valuable information on muscular strength and power in youth lower limbs,and has been shown to be related to bone health..

    Is Playing Soccer More Osteogenic for Females Before the Pubertal Spurt?

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    The aims of this study were to assess bone mass in children and adolescent soccer players and to evaluate the influence of both gender and pubertal status on bone mass. A total of 110 soccer players (75 males / 35 females; 12.73 ± 0.65 / 12.76 ± 0.59 years) participated in this cross-sectional study. They were divided into two groups according to their pubertal status. Bone and lean masses were measured with Dual-energy X-ray Absorptiometry. An independent t-test and an adjusted by subtotal lean and training experience multivariate analysis of covariance were used to analyse the differences in bone mass values between genders and maturity status. Female soccer players presented higher bone mass values than their male counterparts in most of the measured weight-bearing sites. Moreover, when stratifying by pubertal status, peripubertal and postpubertal females had higher subtotal body and lumbar spine bone mass than males. Comparing between pubertal status groups before adjustment, both male and female postpubertal players showed higher bone mass than their pubertal counterparts. After adjusting, these differences disappeared and, in fact results were inverted as bone mass at the femoral neck was higher in both male and female peripubertal soccer players than in postpubertal players. Bone mass seems to be more intensely stimulated by playing soccer in female than male players, particularly in the lumbar spine. The results of peripubertal players showing higher bone mass at the femoral neck after adjusting suggest that playing soccer during the peripubertal stage could be an effective activity to achieve optimal bone mass values

    The effects of age, organized physical activity and sedentarism on fitness in older adults: An 8-year longitudinal study

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    The aims of the present study were (1) to describe the changes in physical fitness during an 8 year follow-up in a large sample of Spanish adults aged 65 or over that are initially engaged in organized physical activity (OPA), (2) to compare fitness changes according to different age groups (65 to 69 vs. 70 to 74 vs. =75 years-old), (3) to evaluate the independent and combined effects of changes in OPA engagement and sitting time (ST) on physical fitness. A total of 642 (147 males) non-institutionalized over 65 years-old participants completed the EXERNET battery fitness tests and completed a validated questionnaire from which information regarding OPA and ST were collected. All participants completed evaluations in 2008-2009 and in 2016-2017. An impairment of fitness-related variables happens after 65 years of age in both males and females, with the older participants (=75), showing the largest decreases. Males who continued performing OPA demonstrated lower decreases in balance, leg flexibility and agility when compared to those who stopped performing OPA during the follow-up. Females who continued performing OPA demonstrated lower decreases of all variables except for balance when compared to those who stopped performing OPA during the follow-up
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