Further observations on the relationship of EMG and muscle force

Human skeletal muscle may be regarded as an electro-mechanical transducer. Its physiological input is a neural signal originating at the alpha motoneurons in the spinal cord and its output is force and muscle contraction, these both being dependent on the external load. Some experimental data taken during voluntary efforts around the ankle joint and by direct electrical stimulation of the nerve are described. Some of these experiments are simulated by an analog model, the input of which is recorded physiological soleus muscle EMG. The output is simulated foot torque. Limitations of a linear model and effect of some nonlinearities are discussed

Crystallographic studies of the Escherichia coli quinol-fumarate reductase with inhibitors bound to the quinol-binding site

The quinol-fumarate reductase (QFR) respiratory complex of Escherichia coli is a four-subunit integral-membrane complex that catalyzes the final step of anaerobic respiration when fumarate is the terminal electron acceptor. The membrane-soluble redox-active molecule menaquinol (MQH(2)) transfers electrons to QFR by binding directly to the membrane-spanning region. The crystal structure of QFR contains two quinone species, presumably MQH(2), bound to the transmembrane-spanning region. The binding sites for the two quinone molecules are termed Q(P) and Q(D), indicating their positions proximal Q(P)) or distal (Q(D)) to the site of fumarate reduction in the hydrophilic flavoprotein and iron-sulfur protein subunits. It has not been established whether both of these sites are mechanistically significant. Co-crystallization studies of the E. coli QFR with the known quinol-binding site inhibitors 2-heptyl-4-hydroxyquinoline-N-oxide and 2-[1-(p-chlorophenyl)ethyl] 4,6-dinitrophenol establish that both inhibitors block the binding of MQH(2) at the Q(P) site. In the structures with the inhibitor bound at Q(P), no density is observed at Q(D), which suggests that the occupancy of this site can vary and argues against a structurally obligatory role for quinol binding to Q(D). A comparison of the Q(P) site of the E. coli enzyme with quinone-binding sites in other respiratory enzymes shows that an acidic residue is structurally conserved. This acidic residue, Glu-C29, in the E. coli enzyme may act as a proton shuttle from the quinol during enzyme turnover

Bulk Etch Rate Measurements and Calibrations of Plastic Nuclear Track Detectors

New calibrations of CR39 and Makrofol nuclear track detectors have been obtained using 158 A GeV Pb (82+) and In (49+) ions; a new method for the bulk etch rate determination, using both cone height and base diameter measurements was developed. The CR39 charge resolution based on the etch-pit base area measurement is adequate to identify nuclear fragments in the interval 7 <= Z/beta <= 49. For CR39 the detection threshold is at REL~50 MeV cm^2/g, corresponding to a nuclear fragment with Z/beta~7. Base cone area distributions for Makrofol foils exposed to Pb (82+) ions have shown for the first time all peaks due to nuclear fragments with Z > 50; the distribution of the etched cone heights shows well separated individual peaks for Z/beta = 78 - 83 (charge pickup). The Makrofol detection threshold is at REL 2700 MeV cm^2/g, corresponding to a nuclear fragment with Z/beta~50.Comment: 11 pages, 5 EPS figures. Submitted to Nucl. Instr. Meth.

Cosmic rays 10Be biennal data and their relationship to aurorae and sunspots

The galactic cosmic ray (C.R.) variations which should give information on three dimensional aspects of the heliospheric magnetic fields and on the solar wind, which modulate their influx into the Solar System were studied. In order to decode the information from the C.R. series it is necessary to know the mechanisms through which the modulation is produced. It it clear that a balance of effects with sources at different heliospheric latitudes results in the modulated C.R. intensity. It is found that the modulation of 10Be in polar ice may be due to at least two main contributions: (1) negative and in phase with the Solar flare activity modulating the cosmic ray flux in Forbush-type decreases, and (2) positive in phase with the appearance of large wind streams situated at both polar coronal holes. It is found that the high heliolatitude activity is related to a stable periodicity of 11.1y whereas the low heliolatitude activity contributes to the wondering of the solar cycles

The energy-oriented management of public historic buildings: An integrated approach and methodology applications

In the European framework, there is a strong drive to develop integrated approaches aimed at understanding and improving the energy behavior of public historic buildings within urban contexts. However, the examples already provided tend to address the issue from mono-disciplinary perspectives, losing the opportunity for a coordinated view. The research suggests a methodology to reach the definition of a three-dimensional database, which incorporates spatial models and energy information, with the final goal of merging heterogeneous information that is useful to interpret the overall framework and to design sustainable development scenarios. The platform achieves GIS (Geographic Information System) and BIM (Building Information Modeling) integration by using the CityGML data model, for supporting multi-scale analyses without break of continuity, ranging from urban to building level. The discussion combines the applicative case with the theoretical background, deepening the role of a solid knowledge framework as a basis for sustainable interventions on public historic buildings. To better explain and test the methodology, a case study on the University built heritage of Pavia is presented and three possible outputs deriving from the database are discussed. The example demonstrates the strength of the approach, which is able to provide a variety of results coming from a unique source of information, ensuring coherence and unambiguousness at all levels of investigation

Evaluation of metaperception of goal orientation and moral functioning in soccer spectators

La violencia en el fútbol es un grave problema social. Algunas de sus manifestaciones están relacionadas con el espectáculo deportivo y su tratamiento en los medios de comunicación. La finalidad de este estudio ha sido analizar las propiedades psicométricas de dos escalas en español que miden la meta-percepción de orientación de meta y el funcionamiento moral en espectadores de fútbol. Los participantes fueron estudiantes universitarios (N = 616) que completaron cuestionarios valorando el tiempo dedicado al consumo de programas deportivos sobre fútbol, la meta-percepción de orientación de meta y el funcionamiento moral. Las escalas definitivas mostraron una adecuada validez de constructo, validez convergente y validez concurrente. Estos resultados indican que las nuevas escalas poseen adecuadas propiedades psicométricas, lo que permite una evaluación válida y fiable que mejore el entendimiento de los procesos que operan en los espectadores de deportes como el fútbolSoccer violence is a serious social problem. Some of its manifestations are related to competitive sport and its treatment by the mass media. The purpose of this study was to analyze the psychometric properties of two Spanish scales which measure the metaperception of goal orientation and moral functioning in soccer spectators. Participants (N = 616) reported the time spent viewing soccer sport programming, and rated metaperception of goal orientation and moral functioning. The scales exhibited adequate construct, convergent and concurrent validity. These results indicate that the new scales have adequate psychometric properties, allowing a valid and reliable assessment in order to explain the processes that take place in sport spectators like soccer viewer

Collaborative facilitation and collaborative inhibition in virtual environments

Worldwide, organizations and small and medium-sized enterprises have already disruptively changed in many ways their physiological inner mechanisms, because of information and communication technologies (ICT) revolution. Nevertheless, the still ongoing COVID-19 worldwide emergency definitely promoted a wide adoption of teleworking modalities for many people around the world, making it more relevant than before to understand the real impact of virtual environments (VEs) on teamwork dynamics. From a psychological point of view, a critical question about teleworking modalities is how the social and cognitive dynamics of collaborative facilitation and collaborative inhibition would affect teamwork within VEs. This study analyzed the impact of a virtual environment (VE) on the recall of individuals and members of nominal and collaborative groups. The research assessed costs and benefits for collaborative retrieval by testing the effect of experimental conditions, stimulus materials, group size, experimental conditions order, anxiety state, personality traits, gender group composition and social interactions. A total of 144 participants were engaged in a virtual Deese-Roediger-McDermott (DRM) classical paradigm, which involved remembering word lists across two successive sessions, in one of four protocols: I-individual/nominal, I I -nominal/individual, I I I -nominal/collaborative, I V -collaborative/nominal. Results suggested, in general, a reduced collaborative inhibition effect in the collaborative condition than the nominal and individual condition. A combined effect between experimental condition and difficulty of the task appears to explain the presence of collaborative inhibition or facilitation. Nominal groups appeared to enhance the collaborative groups’ performance when virtual nominal groups come before collaborative groups. Variables such as personality traits, gender and social interactions may have a contribution to collaborative retrieval. In conclusion, this study indicated how VEs could maintain those peculiar social dynamics characterizing the participants’ engagement in a task, both working together and individually, and could affect their intrinsic motivation as well as performances. These results could be exploited in order to design brand new and evidenced-based practices, to improve teleworking procedures and workers well-being, as well as teleworking teamwork effectiveness.</jats:p

A survey on the use of antibacterial in orthopaedic surgery

The aim of this study is the comprehensive (pre-operative, operative and post-operative) evaluation of the use of antibacterial drugs on a group of patients subjected to orthopaedical surgery. The data regarding 1000 orthopaedic surgical operations, corresponding to 1000 non-urgent patients, have been examined. This study reveals the incongruity in the use of antibacterial drugs in the orthopaedic surgical activity mainly in operative prophylaxis, but also the administration during the intra operative period, and the use of the same drugs in the post operative perio

3x2 Achievement Goals, Friendship and Affectivity in Physical Education: Age-Gender Differences

Se persiguen tres objetivos: (a) analizar las diferencias relativas a la edad y sexo en las metas de logro 3x2, metas de amistad, y afectividad en Educación Física, (b) estudiar las relaciones entre esas variables, y (c) explorar el valor predictivo de las metas de logro 3x2 y amistad sobre la afectividad. La muestra estuvo formada por 1610 alumnos (855 varones y 755 mujeres) de 10 a 17 años. Se realizaron MANOVAS, análisis univariados (Scheffé), y regresiones lineales. Los resultados mostraron un descenso significativo de las metas de logro (excepto aproximación-otro), metas de amistad y afecto positivo debido al desarrollo. Los varones puntuaron más alto las metas de aproximación-tarea, aproximación-otro, y evitación-otro. Las metas de aproximación-tarea y aproximación-amistad fueron los principales predictores positivos del afecto positivo. La franja de 13 a 14 años muestra una gran sensibilidad a los tres estándares de competencia de logro, competencia social e inestabilidad afectivaThe objectives of the study are three: (a) to analyze the differences related to age and sex in the 3x2 achievement goals, the friendship goals, and the affectivity in Physical Education, (b) to study the relationships between these variables, and c) to explore the predictive value of the 3x2 achievement goals and friendship on affectivity. The sample consisted of 1610 students (855 males and 755 females), aged between 10 and 17 years. MANOVAS, univariate analyzes (Scheffé), and linear regressions were performed. The results showed a significant decrease in achievement goals (except other-approach), friendship goals, and positive affect due to development. Males scored higher on task-approach, other-approach, and other-avoidance goals than women. Task-approach and friendship-approach were the main positive predictors of positive affect. The range of 13 to 14 years shows a great sensitivity to the three competences of achievement, social competence, and affective instabilit