The nilpotent (n,n(n+1)/2) sub-Riemannian problem

In this paper we study the sub-Riemannian geodesic problem determined by a left invariant distribution of dimension n in a nilpotent Lie group G of dimension n(n+1)/2. The problem is formulated as an left invariant optimal control sytem. We describe a group action that leaves invariant the system. We apply Pontryagin maximum to derive necessary conditions for the optimality of the geodesics. For n odd abnormal extremals do exists, but they turn out to be non-strictly abnormal. The adjoint equation for the normal extremals is explicitly integrated. At the end, we specialize our results in some of the known low dimensional cases, namely, the Heisenberg (2,3) case and the (3,6) case

Integrability of nilpotent sub-Riemannian structures

We consider the action of a Lie group that leaves invariant the sub-Riemannian structures associated to Goursat systems and Euclidean metrics. The low dimensional cases contain the well-known Heisenberg group, as well as the nilpotent groups associated to the Martinet and Engel systems. For arbitrary dimensions, we establish the complete integrability of the associated adjoint system by means of the explicit calculation of Casimir functions of the associated nilpotent Poisson algebra. We define a new algebraic curve in total space and compute two examples of sub-Riemannian extremals in cotangent space. Our approach fits certain non-holonomic classical problems, particularly that of the physical model for a plasma considered as a gas of non interacting charged particles under the influence of a static non homogeneous magnetic field

Psychological Impact during Confinement by COVID-19 on Health Sciences University Students—A Prospective, Longitudinal, and Comparative Study

The objective was to analyze the factors that influence reactions to confinement situations, such as personality, humor, coping with stressors, and resilience, and to compare this population with a normal situation of exposure to an intense academic stressor such as a partial test, and with the confinement situation caused by the COVID-19 pandemic. Methods: A longitudinal study was performed involving 116 health sciences students from Spain. Three situations were evaluated: a basal situation of normality at the beginning of the course, situation facing an academic stressor (partial test), and confinement situation due to COVID-19. The Positive and Negative Affect Schedule (PANAS), Coping Orientation to Problems Experienced (COPE), Connor–Davidson Resilience Scale, and NEO-FFI scale were used. Results: Significant differences were observed in the increase in negative humor and decrease in positive one, as well as decrease in “Focus on and Venting of Emotions”. Personality factors that better predict humor at confinement were “conscientiousness” for having positive humor and low “extraversion” for negative humor. Conclusions: The confinement situation due to COVID-19 has caused changes in predominant humor, as well as in coping strategies. Personality factors positively or negatively influence the situation

El Desarrollo de la Marcha Infantil como Proceso de Aprendizaje

Children gait development is a particularly complex process in which motor, perceptual, and cognitive factors interact. From the moment of birth, the child integrates the information he receives and builds up a progressive cortical control on the innate neuromotor patterns to develop different forms of locomotion until achieving  independent gait. These ideas are not new but they are currently being reviewed and have encouraged numerous changes in the study of child development. Considering gait acquisition as a learning process in changing situations allows to understand gait as an action which involves the acquisition of new knowledge and interaction capabilities. This paper summarizes the main body of knowledge about this learning process and intends to highlight gait alterations as indicators of development difficulties, requiring interdisciplinary assessment and therapeutic approach.ResumenEl desarrollo de la marcha infantil es un proceso especialmente complejo en que el intervienen  factores motores, perceptivos y cognitivos. Desde el nacimiento, el niño integra la información recibida y realiza un progresivo control cortical sobre los patrones neuromotores innatos para desarrollar diferentes formas de locomoción hasta la marcha independiente. Estas ideas no son novedosas pero se están revisando en la actualidad y han motivado numerosos cambios en el estudio del desarrollo infantil. La consideración de la adquisición de la marcha como un aprendizaje en situaciones de constante cambio permite comprender la marcha como acción, cuya realización implica la adquisición de nuevas capacidades de interacción y conocimientos. En este trabajo se exponen los  principales conocimientos acerca de este proceso de aprendizaje y se propone destacar las alteraciones de la marcha como indicadores de dificultades en el desarrollo, que requieren una valoración y un abordaje terapéutico interdisciplinares. AbstractChildren gait development is a particularly complex process in which motor, perceptual, and cognitive factors interact. From the moment of birth, the child integrates the information he receives and builds up a progressive cortical control on the innate neuromotor patterns to develop different forms of locomotion until achieving  independent gait. These ideas are not new but they are currently being reviewed and have encouraged numerous changes in the study of child development. Considering gait acquisition as a learning process in changing situations allows to understand gait as an action which involves the acquisition of new knowledge and interaction capabilities. This paper summarizes the main body of knowledge about this learning process and intends to highlight gait alterations as indicators of development difficulties, requiring interdisciplinary assessment and therapeutic approach.

The COVID-19 Student Stress Questionnaire: Validation in Spanish university students from health sciences

This study aimed to validate the Spanish version of the COVID-19 Student Stress Questionnaire (CSSQ), a 7-item tool assessing COVID-19-related stressors among university students, namely, Relationships and Academic Life, Isolation, and Fear of Contagion. Participants were 331 Spanish university students. Factor analyses sustained the three factor solution of the original tool. Data also revealed satisfactory convergent and discriminant validity, suitable internal consistency, and significant associations with psychological symptoms, as measured by the Symptom Checklist-90-Revised. The Spanish version of the CSSQ represents a valid tool to be used in clinical settings to timely identify students at high psychological risk and to develop evidence-based interventions during/after the pandemic

Occupational and Leisure-Time Physical Activity Related to Job Stress and Job Satisfaction: Correspondence Analysis on a Population-Based Study

Leisure-time physical activity (LTPA) is not the same as occupational activity. Various factors influence both forms of physical activity, including job stress and job satisfaction, but the associations found are weak, and the need for new studies in large populations is emphasized. The objective was to study the relationship between job stress and job satisfaction, and the relationship between these and occupational and leisure-time physical activity according to the National Survey of Health 2017.Ye

COVID-19 Infection among Nursing Students in Spain: The Risk Perception, Perceived Risk Factors, Coping Style, Preventive Knowledge of the Disease and Sense of Coherence as Psychological Predictor Variables: A Cross Sectional Survey

The exploration of patterns of health beliefs about COVID-19 among nursing students may be beneficial to identify behaviors, attitudes and knowledge about contagion risk. We sought to analyze the variables of risk perception, perceived risk factors, coping style, sense of coherence and knowledge of preventive measures as possible predictors of having suffered from COVID-19. Participants were nursing students from 13 universities in Spain. Sociodemographic and health variables were collected. To test the independent variables, the Perception Risk Coping Knowledge (PRCK-COVID-19) scale was created and validated because there was no specific survey for young people adapted to the pandemic situation of COVID-19. It was validated with adequate psychometric properties. A total of 1562 students (87.5% female, mean age 21.5 ± 5.7 years) responded. The high perception of the risk of contagion, the high level of knowledge and a coping style focused on the situation were notable. Significant differences by gender were found in the coping styles, problem-focused, avoidance and knowledge scales, with women scoring higher in all categories. The multiple regression analysis was significant (F = 3.68; p < 0.001). The predictor variables were the coping styles subscale search for support and the intrinsic and extrinsic perceived risk factors. Our model predicts that nursing students with a social support-based coping style are at a higher risk of becoming infected with COVID-19, based on their own health belief model.Funding: This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. Acknowledgments: We are grateful to all participating institutions and students

Design of the EBE-ST questionnaire among nursing students: mnulticenter study from eight universities in Spain

Background: Twenty years after the degree in nursing was introduced in Spain, the subject of evidence-based nursing is still unstructured and unestablished in most faculties. Moreover, there are hardly any rigorous studies at a national level that evaluate the current state of this competence in our faculties. Understanding the starting point is essential for the curricular design to ensure that evidence-based practice is implemented among future professionals. Aim: To design and validate an evidence-based nursing competency questionnaire for fourth-year nursing students. Methods: A specific questionnaire was developed and validated (EBE-ST). A cross-sectional survey design with psychometric validation of an instrument. Participants were 304 senior year nursing students from eight universities in Spain (2020). Results: The EBE-ST questionnaire is composed of 33 items that determine eight factors. It presents adequate reliability and validity (alpha = 0.882), measuring knowledge, attitudes and the practical application of evidence-based practice. Conclusions: We have created an instrument with good psychometric properties to measure evidence-based practice competence among senior nursing students. The heterogeneity of knowledge regarding evidence-based nursing in our country suggests that further reflection is warranted on the incorporation of this topic during undergraduate training. We have designed and validated an evidence-based nursing competency questionnaire specific to nursing student