2,369 research outputs found
Heat pumping in nanomechanical systems
We propose using a phonon pumping mechanism to transfer heat from a cold to a
hot body using a propagating modulation of the medium connecting the two
bodies. This phonon pump can cool nanomechanical systems without the need for
active feedback. We compute the lowest temperature that this refrigerator can
achieve.Comment: 4 pages, 1 figure, published versio
Studies on Soil Transmitted Helminthic Infection Among Coal Miners in Sawah Lunto, West Sumatra
Prevalensi cacing Perut diantara karyawan tambang batu bara Ombilin Sawah Lunto adalah 91,2 persen, 39,8 persen dan 13,persen masing-masing untuk cacing tambang, Ascaris lumbricoides dan Trichuris trichiura. Sebagian besar karyawan tambang bati bara ini menderita anemia (hanya 13,3 persen diantara mereka yang mempunyai kadar haemoglobin dalam batas-batas normal). Ukuran persen diantara mereka yang mempunyai kadar haemoglobin dalam batas-batas normal). Ukuran Unthropometrik menunjukkan bahwa hanya 62,5 persen berat badak untuk tinggi badan karyawan tambang ini termasuk kategori 90 persen atau lebih Standard nasional yang diusulkan. Percobaan pengobatan dengan menggunakan tetramisole (ascaridil) menunjukkan bahwa obat ini memberikan hasil yang memuaskan hanya untuk infestasi A. lumbricoides
Methodological considerations in assessing interlimb coordination on poststroke gait: a scoping review of biomechanical approaches and outcomes
To identify and summarize biomechanical assessment approaches in interlimb coordination on poststroke gait. Interlimb coordination involves complex neurophysiological mechanisms that can be expressed through the biomechanical output. The deepening of this concept would have a significant contribution in gait rehabilitation in patients with an asymmetric neurological impairment as poststroke adults. Poststroke adults (>19 years old), with assessment of interlimb coordination during gait, in an open context, according to the Population, Concept, Context framework. A literature search was performed in PubMed, Web of Science™, Scopus, and gray literature in Google Scholar™, according to the PRISMA-ScR recommendations. Studies written in Portuguese or English language and published between database inception and 14 November 2021 were included. Qualitative studies, conference proceedings, letters, and editorials were excluded. The main conceptual categories were “author/year”, “study design”, “participant’s characteristics”, “walking conditions”, “instruments” and “outcomes”. The search identified 827 potentially relevant studies, with a remaining seven fulfilling the established criteria. Interlimb coordination was assessed during walking in treadmill (n = 3), overground (n = 3) and both (n = 1). The instruments used monitored electromyography (n = 2), kinetics (n = 2), and kinematics (n = 4) to assess spatiotemporal parameters (n = 4), joint kinematics (n = 2), anteroposterior ground reaction forces (n = 2), and electromyography root mean square (n = 2) outcomes. These outcomes were mostly used to analyze symmetry indices or ratios, to calculate propulsive impulse and external mechanical power produced on the CoM, as well as antagonist coactivation. Assessment of interlimb coordination during gait is important for consideration of natural auto-selected overground walking, using kinematic, kinetic, and EMG instruments. These allow for the collection of the main biomechanical outcomes that could contribute to improve better knowledge of interlimb coordination assessment in poststroke patients.info:eu-repo/semantics/publishedVersio
Adaptation and validation of the WHOQOL-OLD for the Portuguese population: Results of focus groups implementation
No âmbito dos estudos de adaptação e validação do WHOQOL-OLD, foram
implementados oito grupos focais, num total de 33 participantes, em amostra de
conveniência: um com profissionais em formação (N=4), um com cuidadores
(N=4) e seis grupos com adultos idosos (N=25; quatro com idosos da comunidade e dois com idosos institucionalizados). Os resultados corroboram a natureza
multidimensional do constructo QdV. Foram evocados espontaneamente os seis
domínios do WHOQOL-100 e todas as suas facetas (exceptuando Actividade sexual), bem como as seis facetas do WHOQOL-OLD. Com maior frequência, oadultos idosos destacam Qualidade de vida e saúde geral e dimensões de Relações
sociais, Ambiente, Psicológico, Aspectos espirituais e Autonomia; os cuidadores
referem dimensões de Autonomia, Saúde, Ambiente e Relações sociais; e os profissionais destacam Saúde, Nível de independência, Ambiente e Relações sociais.
Por todos os grupos foi apontada a dimensão “Família/Vida familiar”, que poderá constituir-se como uma nova faceta do módulo WHOQOL-OLD português
Relación entre el bienestar y el rendimiento académico en alumnos de primer año de medicina
Background: Stress may affect the sense of wellbeing and academic achievement of university students. Aim: To assess the relationship of academic engagement and burnout with academic achievement among first year medical students. Material and Methods: The Utrecht Work Engagement Scale-Student and Maslach Burnout Inventory Student Survey (MBI-SS) were applied to 277 first year medical students of four universities. Their results were correlated with the grades obtained in the different courses. Results: Moderately high engagement and low burnout levels were detected. There was a high level of satisfaction with studies and a moderate exhaustion level. Academic achievement was associated with the degree of engagement with studies but not with burnout. Conglomerate analysis detected a group of students with high levels of wellbeing, characterized by high levels of academic engagement and low burnout. Other group had moderate levels of engagement and lack of personal fulfilment. Other group, identified as extenuated, had high levels of personal exhaustion and depersonalization. Finally the disassociated group had a low academic engagement, low emotional exhaustion, high levels of depersonalization and lack of personal fulfillment. Conclusions: Academic achievement is associated with the level of engagement with studies but not with burnout
Assessment of psychometric properties of the academic involvement questionnaire, expectations version
Indexación: Web of Science; Scielo.Background: Academic Involvement Questionnaire, Expectations version (CIA-A), assesses the expectations of involvement in studies. It is a relevant predictor of student success. However, the evidence of its validity and reliability in Chile is low, and in the case of Medical students, there is no evidence at all. Aim: To evaluate the factorial structure and internal consistency of the CIA-A in Chilean Medical school freshmen. Material and Methods: The survey was applied to 340 Medicine freshmen, chosen by non-probability quota sampling. They answered a back-translated version of CIA-A from Portuguese to Spanish, plus a sociodemographic questionnaire. For psychometric analysis of the CIA-A, an exploratory factor analysis was carried on, the reliability of the factors was calculated, a descriptive analysis was conducted and their correlation was assessed. Results: Five factors were identified: vocational, institutional and social involvement, use of resources and student participation. Their reliabilities ranged between Cronbach’s alpha values of 0.71 to 0.87. Factors also showed statistically significant correlations between each other. Conclusions: Identified factor structure is theoretically consistent with the structure of original version. It just disagrees in one factor. In addition, the factors’ internal consistency were adequate for using them in research. This supports the construct validity and reliability of the CIA-A to assess involvement expectations in medical school freshmen.http://ref.scielo.org/r2sn6
Evaluación toxicológica no invasiva del cadmio: modificaciones de biomarcadores conductuales en Cyprinus carpio
Se describe un dispositivo que permite evaluar simultáneamente varios parámetros conductuales de peces en cautiverio. Se informan los resultados preliminares alcanzados al exponer juveniles (3-4 g) de la carpa común (Cyprinus carpio) a dos soluciones subletales de de Cd2+ (0.3 y 0.5 mg/L), determinándose los cambios en su actividad natatoria (expresada cuantitativamente mediante un Indice de actividad relativa, Ia) y en sus preferencias altitudinal y lateral en los acuarios. La actividad natatoria total se redujo significativamente a la concentración más elevada del metal, retornando a los niveles basales registrados en el período Control luego de transferir los peces a medio sin el metal. La preferencia altitudinal, resultó modificada, encontrándose que los peces expuestos al metal se hallaban la mayor cantidad de tiempo en la capa superior de los acuarios. En cuanto a la preferencia lateral el resultado más importante fue la evidencia de que los mismos peces evitaban la sección correspondiente al sitio de goteo de la solución de Cadmio, sin hallarse un patrón particular de distribución en el resto de las secciones de los acuarios. Los cambios en la actividad natatoria total y en la preferencia altitudinal de los peces fueron reversibles; en cambio, la alteración en la preferencia lateral no se modificó luego del reemplazo de las soluciones de Cd por medios limpios.Trabajo presentado en II Jornadas sobre Ecología y Manejo de Ecosistemas Acuáticos Pampeanos (EMEAP) (La Plata, 2002)
Repeatability and temporal consistency of lower limb biomechanical variables expressing interlimb coordination during the double-support phase in people with and without stroke sequelae
Reliable biomechanical methods to assess interlimb coordination during the double-support phase in post-stroke subjects are needed for assessing movement dysfunction and related variability. The data obtained could provide a significant contribution for designing rehabilitation programs and for their monitorisation. The present study aimed to determine the minimum number of gait cycles needed to obtain adequate values of repeatability and temporal consistency of lower limb kinematic, kinetic, and electromyographic parameters during the double support of walking in people with and without stroke sequelae. Eleven post-stroke and thirteen healthy participants performed 20 gait trials at self-selected speed in two separate moments with an interval between 72 h and 7 days. The joint position, the external mechanical work on the centre of mass, and the surface electromyographic activity of the tibialis anterior, soleus, gastrocnemius medialis, rectus femoris, vastus medialis, biceps femoris, and gluteus maximus muscles were extracted for analysis. Both the contralesional and ipsilesional and dominant and non-dominant limbs of participants with and without stroke sequelae, respectively, were evaluated either in trailing or leading positions. The intraclass correlation coefficient was used for assessing intra-session and inter-session consistency analysis. For most of the kinematic and the kinetic variables studied in each session, two to three trials were required for both groups, limbs, and positions. The electromyographic variables presented higher variability, requiring, therefore, a number of trials ranging from 2 to >10. Globally, the number of trials required inter-session ranged from 1 to >10 for kinematic, from 1 to 9 for kinetic, and 1 to >10 for electromyographic variables. Thus, for the double support analysis, three gait trials were required in order to assess the kinematic and kinetic variables in cross-sectional studies, while for longitudinal studies, a higher number of trials (>10) were required for kinematic, kinetic, and electromyographic variables.info:eu-repo/semantics/publishedVersio
Evaluación toxicológica no invasiva del cadmio: modificaciones de biomarcadores conductuales en <i>Cyprinus carpio</i>
Se describe un dispositivo que permite evaluar simultáneamente varios parámetros conductuales de peces en cautiverio. Se informan los resultados preliminares alcanzados al exponer juveniles (3-4 g) de la carpa común (Cyprinus carpio) a dos soluciones subletales de de Cd2+ (0.3 y 0.5 mg/L), determinándose los cambios en su actividad natatoria (expresada cuantitativamente mediante un Indice de actividad relativa, Ia) y en sus preferencias altitudinal y lateral en los acuarios. La actividad natatoria total se redujo significativamente a la concentración más elevada del metal, retornando a los niveles basales registrados en el período Control luego de transferir los peces a medio sin el metal. La preferencia altitudinal, resultó modificada, encontrándose que los peces expuestos al metal se hallaban la mayor cantidad de tiempo en la capa superior de los acuarios. En cuanto a la preferencia lateral el resultado más importante fue la evidencia de que los mismos peces evitaban la sección correspondiente al sitio de goteo de la solución de Cadmio, sin hallarse un patrón particular de distribución en el resto de las secciones de los acuarios. Los cambios en la actividad natatoria total y en la preferencia altitudinal de los peces fueron reversibles; en cambio, la alteración en la preferencia lateral no se modificó luego del reemplazo de las soluciones de Cd por medios limpios.Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) - Instituto de Limnología "Dr. Raul A. Ringuelet" (ILPLA
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