ABSTRACT
El objetivo del presente estudio fue analizar la relación entre las capacidades físicas, el hábito de realizar actividad física y la capacidad de atención selectiva en una muestra de estudiantes de enseñanza secundaria. La muestra fue configurada por un total de 97 participantes, concretamente 51 estudiantes de género femenino (n = 51) y 46 de género masculino (n = 46) de Barcelona (Cataluña) con edades comprendidas entre los 13 y los 15 años (13,7 ± 1,17). Para analizar la capacidad de atención selectiva se utilizó el Test de Percepción de Semejanzas y Diferencias (CARAS-R). Referente a la condición física, se evaluó la velocidad lineal (30 metros lisos), la fuerza de tren inferior (test de salto horizontal), la agilidad (test de10x5 metros) y la resistencia aeróbica (test de Luc-Léger). Finalmente el hábito de realización de actividad física se calculó con el Cuestionario internacional de actividad física en su formato adaptado para adolescentes (IPAQ-A). Los resultados mostraron que los participantes con un mayor rendimiento en el test de Luc-Léger, obtuvieron mejores puntuaciones en el test CARAS-R. Asimismo se obtuvo una correlación alta entre los registros del test de Luc-Léger y el test CARAS-R tanto para el género masculino como el femenino y una correlación alta entre el cuestionario IPAQ-A y el test CARAS-R en el género masculino. Dichos hallazgos, ponen de manifiesto la relación entre la atención selectiva y el nivel de condición física en adolescentes. En este sentido, se refuerza la importancia de practicar actividad física a esta edad, sugiriendo que el incremento de la condición física puede tener implicaciones positiva sobre la atención selectiva.
The aim of this study was to analyze the relationship between fitness, selective attention and the physical activity habit in high school students. The sample was configured by a total of 97 participants, 51 females (n = 51) and 46 males (n = 46) from Barcelona (Catalonia), aged between 13 and 15 years (13,7 ± 1,17). To analyze the selective attention capacity, it was used the Perception of Similarities and Differences Test (CARAS-R). Regarding physical fitness, linear velocity (30-meter dash test), lower body strength (board jump test), agility (10x5 meter test) and aerobic capacity (Luc-Léger test) were evaluated. Finally, the physical activity was calculated with the International Physical Activity Questionnaire adapted for adolescents (IPAQ-A). The results showed that the subjects with higher performance in the Luc-Léger test obtained better scores in the CARAS-R test. A high correlation was also obtained between the records of the Luc-Léger test and the CARAS-R test in both boys and girls and a high correlation between the IPAQ-A questionnaire and the CARAS-R test in boys. These findings highlight the relationship between selective attention and the fitness level in adolescents. In this sense, the importance of practicing physical activity at this age is reinforced, suggesting that the increase of physical condition may have positive implications on selective attention.
O objetivo do presente estudo foi analisar a relação entre habilidades físicas, atenção seletiva e o hábito de praticar atividade física numa amostra de estudantes do ensino médio. A amostra foi composta por um total de 97 sujeitos, especificamente 51 estudantes do sexo feminino (n = 51) e 46 do sexo masculino (n = 46) de Barcelona (Catalunha) com idades entre 13 e 15 anos (13,7 ± 1,17). Para analisar a capacidade de atenção seletiva, foi utilizado o Teste de Percepção de Diferenças e Diferenças (CARAS-R). A condição física foi avaliada através do teste de 30 metros de velocidade suave (velocidade linear), do teste de salto horizontal (força do corpo inferior), do teste de 10x5 metros (agilidade) e do teste de Luc-Léger (resistência). Por fim, o hábito de realizar atividade física foi calculado com o Questionário Internacional de Atividade Física, em formato adaptado para adolescentes (IPAQ-A). Os resultados mostraram que os sujeitos com maior desempenho no teste Luc-Léger obtiveram melhores pontuações no teste CARAS-R. Da mesma forma, foi obtida uma alta correlação entre os registros do teste Luc-Léger e o teste CARAS-R em meninos e meninas e uma alta correlação entre o questionário IPAQ-A e o teste CARAS-R em meninos. Os resultados revelam a relação entre a atenção seletiva e o nível de aptidão física em adolescentes. Nesse sentido, a importância da prática de atividade física nessa faixa etária é reforçada, sugerindo que o aumento da condição física pode ter implicações positivas na atenção seletiva. (AU)
Subject(s)
Humans , Male , Female , Adolescent , Attentional Bias , Motor Activity , Physical Fitness , Exercise , Surveys and Questionnaires , Education, Primary and SecondaryABSTRACT
This work demonstrates a novel broadband optical switch, based on dynamic-scattering effect in liquid crystals (LCs). Dynamic-scattering-mode technology was developed for display applications over four decades ago, but was displaced in favor of the twisted-nematic LCs. However, with the recent development of more stable LCs, dynamic scattering provides advantages over other technologies for optical switching. We demonstrate broadband polarization-insensitive attenuation of light directly passing thought the cell by 4 to 5 orders of magnitude at 633 nm. The attenuation is accomplished by light scattering to higher angles. Switching times of 150 µs to 10% transmission have been demonstrated. No degradation of devices is found after hundreds of switching cycles. The light-rejection mechanism is due to scattering, induced by disruption of LC director orientation with dopant ion motion with an applied electric field. Angular dependence of scattering is characterized as a function of bias voltage.
ABSTRACT
The optical switching time of twisted-nematic liquid-crystal cells using the liquid crystals, 5CB (C(5)H(11)-Ph-Ph-CN), 5OCB(C(5)H(11)-O-Ph-Ph-CN) and PCH5 (C(5)H(11)-Cy-Ph-CN) have been characterized as a function of temperature, bias voltage and switching voltage, V. The transition time from 90% to 10% transmission scales as V(-1.9) and is limited to 30 to 50 ns by the liquid-crystal breakdown electric field, ~100 V µm(-1). The time from the initial switching voltage step to 90% transmission, delay time, decreases with increasing bias and switching voltage. For 5CB and 5OCB the delay time approaches a constant value at higher electric fields, >10 V µm(-1). Both the transition and delay times decrease with increasing temperature. The minimum transition time at temperatures a few degrees below the nematic-isotropic temperature are 32, 32, and 44 ns and delay times are 44, 25 and 8 ns for 5CB, 5OCB, and PCH5 respectively.
ABSTRACT
SOI CMOS compatible Si waveguide photodetectors are made responsive from 1100 to 1750 nm by Si+ implantation and annealing. Photodiodes have a bandwidth of >35 GHz, an internal quantum efficiency of 0.5 to 10 AW-1, and leakage currents of 0.5 nA to 0.5 microA. Phototransistors have an optical response of 50 AW-1 with a bandwidth of 0.2 GHz. These properties are related to carrier mobilities in the implanted Si waveguide. These detectors exhibit low optical absorption requiring lengths from <0.3 mm to 3 mm to absorb 50% of the incoming light. However, the high bandwidth, high quantum efficiency, low leakage current, and potentially high fabrication yields, make these devices very competitive when compared to other detector technologies.
Subject(s)
Photometry/instrumentation , Silicon/chemistry , Transducers , Transistors, Electronic , Computer-Aided Design , Equipment Design , Equipment Failure Analysis , Infrared Rays , Microwaves , Reproducibility of Results , Sensitivity and Specificity , Silicon/radiation effectsABSTRACT
A broadband, Mach-Zehnder-interferometer based silicon optical modulator is demonstrated, with an electrical bandwidth of 26 GHz and V(pi)L of 4 V.cm. The design of this modulator does not require epitaxial overgrowth and is therefore simpler to fabricate than previous devices with similar performance.
Subject(s)
Interferometry/instrumentation , Optics and Photonics/instrumentation , Semiconductors , Signal Processing, Computer-Assisted/instrumentation , Silicon/chemistry , Telecommunications/instrumentation , Equipment Design , Equipment Failure AnalysisABSTRACT
The purpose of the study was to determine the overall risk of a permanent stoma in patients with complicated perianal Crohn's disease, and to identify risk factors predicting stoma carriage. A total of 102 consecutive patients presented with the first manifestation of complicated perianal Crohn's disease in our outpatient department between 1992 and 1995. Ninety-seven patients (95%) could be followed up at a median of 16 years after first diagnosis of Crohn's disease. Patients were sent a standardized questionnaire and patient charts were reviewed with respect to the recurrence of perianal abscesses or fistulas and surgical treatment, including fecal diversion. Factors predictive of permanent stoma carriage were determined by univariate and multivariate analysis. Thirty of 97 patients (31%) with complicated perianal Crohn's disease eventually required a permanent stoma. The median time from first diagnosis of Crohn's disease to permanent fecal diversion was 8.5 years (range 0-23 years). Temporary fecal diversion became necessary in 51 of 97 patients (53%), but could be successfully removed in 24 of 51 patients (47%). Increased rates of permanent fecal diversion were observed in 54% of patients with complex perianal fistulas and in 54% of patients with rectovaginal fistulas, as well as in patients that had undergone subtotal colon resection (60%), left-sided colon resection (83%), or rectal resection (92%). An increased risk for permanent stoma carriage was identified by multivariate analysis for complex perianal fistulas (odds ratio [OR] 5; 95% confidence interval [CI] 2-18), temporary fecal diversion (OR 8; 95% CI 2-35), fecal incontinence (OR 21, 95% CI 3-165), or rectal resection (OR 30; 95% CI 3-179). Local drainage, setons, and temporary stoma for deep and complicated fistulas in Crohn's disease, followed by a rectal advancement flap, may result in closing of the stoma in 47% of the time. The risk of permanent fecal diversion was substantial in patients with complicated perianal Crohn's disease, with patients requiring a colorectal resection or suffering from fecal incontinence carrying a particularly high risk for permanent fecal diversion. In contrast, patients with perianal Crohn's disease who required surgery for small bowel disease or a segmental colon resection carried no risk of a permanent stoma.
Subject(s)
Crohn Disease/surgery , Enterostomy , Abscess/complications , Abscess/surgery , Adolescent , Adult , Anus Diseases/complications , Anus Diseases/surgery , Child , Crohn Disease/complications , Female , Humans , Male , Middle Aged , Rectovaginal Fistula/complications , Rectovaginal Fistula/surgery , Risk FactorsABSTRACT
CMOS compatible infrared waveguide Si photodiodes are made responsive from 1100 to 1750 nm by Si(+) implantation and annealing. This article compares diodes fabricated using two annealing temperatures, 300 and 475 degrees C. 0.25-mm-long diodes annealed to 300 degrees C have a response to 1539 nm radiation of 0.1 A W-(-1) at a reverse bias of 5 V and 1.2 A W(-1) at 20 V. 3-mm-long diodes processed to 475 degrees C exhibited two states, L1 and L2, with photo responses of 0.3 +/-0.1 A W(-1) at 5 V and 0.7 +/-0.2 A W(-1) at 20 V for the L1 state and 0.5 +/-0.2 A W(-1) at 5 V and 4 to 20 A W(-1)-1 at 20 V for the L2 state. The diodes can be switched between L1 and L2. The bandwidths vary from 10 to 20 GHz. These diodes will generate electrical power from the incident radiation with efficiencies from 4 to 10 %.
ABSTRACT
BACKGROUND: Granulocyte-colony-stimulating factor (G-CSF) has been used to increase the number of CD34+ peripheral blood stem and progenitor cells collected by apheresis for use in autologous or allogeneic progenitor cell transplantation. The most frequent side effect of G-CSF treatment is bone pain, which occurs in over 80 percent of healthy progenitor cell donors. STUDY DESIGN AND METHODS: The possible mechanism of bone pain was investigated by measuring serum levels of osteocalcin (OC), bone-specific alkaline phosphatase (BAP), acid phosphatase (ACP), and tartrate-resistant acid phosphatase (TRAP) in seven healthy progenitor cell donors treated with human recombinant G-CSF administered subcutaneously for 5 consecutive days. RESULTS: All seven patients experienced bone pain during the treatment period. Serum levels of OC, BAP, ACP, and TRAP were measured in blood samples drawn on Days 0, 4, 5, 6, and 14. Levels of BAP were increased (p<0.05) over baseline on Days 4, 5, and 6, while those of OC decreased on Days 4, 5, and 6 (p<0.05). No significant changes occurred in ACP or TRAP levels. OC and BAP are considered markers of bone formation (osteoblast activity), and they correlate in many patients with metabolic bone disorders. The pattern of increased BAP and decreased OC has been reported in patients with osteolytic bone metastases. CONCLUSION: G-CSF treatment in healthy stem and progenitor cell donors may affect osteoblastic activity, and this activity may be associated with bone pain.
Subject(s)
Alkaline Phosphatase/blood , Blood Donors , Bone and Bones/drug effects , Granulocyte Colony-Stimulating Factor/adverse effects , Hematopoietic Stem Cells , Osteocalcin/blood , Pain/etiology , Bone and Bones/enzymology , HumansABSTRACT
Interest in differentiating community health nursing from home health nursing has focused on theoretical models, concepts, and examinations of the historical origins and evolution of the roles. Although not usually included in the recent differentiation efforts, school and occupational health nursing traditionally have been considered important subspecialties of community health nursing. Utilizing an approach to technology developed by organizational researchers and focusing not on hardware and equipment, but on the characteristics of the raw materials and techniques employed, this study examined the differences among public health/community health, home health, school health, and occupational health on the three technological dimensions of uncertainty, instability, and variability. Survey data from nurses in the four areas (N = 40) were utilized. Results indicated that home health nursing differed significantly from the other groups on the dimensions of uncertainty and instability.
Subject(s)
Community Health Nursing/standards , Medical Laboratory Science , Occupational Health Nursing/standards , Public Health Nursing/standards , School Nursing/standards , Specialties, Nursing/standards , Humans , Models, Nursing , Nursing Methodology Research , Role , Surveys and QuestionnairesABSTRACT
Thep hotoresponseo f Schottkya nd np-diamondd iodes has been measured from 120 to 600 nm. The ultraviolet response is 100 times the visible response.
ABSTRACT
Examinations of the adoption and diffusion processes relative to innovations have focused on a variety of factors including the characteristics of the environment, the adoptive unit, and the innovation itself. This study explored the relationship between environmental factors, organizational characteristics, and the spread of 2-year associate degree nursing (ADN) programs among community colleges in the U.S. Data were secured from census materials, educational directories, community college catalogs, various other documents, and interviews with community college representatives. Results indicated that such factors as general population heterogeneity, change and wealth, and various measures of the need for nurses and nursing education were not useful predictors of the prevalence of ADN programs among the population of community colleges in a state. Two-year colleges that operated ADN programs were larger, wealthier, offered more occupational programs, and were more likely to be publicly controlled than were community colleges that had not adopted the ADN program feature. Analysis of case materials suggested that at the community level, hospitals and hospital-sponsored nursing schools were important factors in the community college's decision to adopt or reject the ADN program feature.
Subject(s)
Communication , Diffusion of Innovation , Education, Nursing, Associate , Universities , Environment , Organizational Innovation , United StatesSubject(s)
Bacillus subtilis/enzymology , Geobacillus stearothermophilus/enzymology , Guanine Nucleotides/metabolism , Guanosine Tetraphosphate/metabolism , Pyrophosphatases/metabolism , Cations, Divalent , Escherichia coli/enzymology , Manganese/metabolism , Molecular Weight , Pyrophosphatases/isolation & purificationABSTRACT
Guanosine 3'-diphosphate 5'-diphosphate (ppGpp) is rapidly degraded to guanosine 5'-diphosphate (ppG) and probably pyrophosphate by an enzyme present in the ribosomal fraction prepared from spoT+ strains of Escherichia coli. The ppGpp-degrading enzyme was released from the ribosomes during dissociation at low ionic strength. Ribosomes are not essential for degradation of ppGpp, and decay of ppGpp is strictly dependent on manganese ions. The reaction is sensitive to inhibition by tetracycline, which can be reversed by MnCl2, indicating that the inhibitory effect is due to the previously described chelating properties of the antibiotic. When the ppGpp-degrading enzyme was complemented with adenosine 5'-triphosphate (pppA) and a nucleoside diphosphate kinase, decay of ppGpp was accelerated yielding pppG and ppG as major products. In the absence of pppA we have been unable to detect the ppGpp-degrading enzyme in various spoT- mutant strains indicating that this enzyme is the spoT gene product.
