Estimating density limits for walking pedestrians keeping a safe interpersonal distancing.

With people trying to keep a safe distance from others due to the COVID-19 outbreak, the way in which pedestrians walk has completely changed since the pandemic broke out1,2. In this work, laboratory experiments demonstrate the effect of several variables-such as the pedestrian density, the walking speed and the prescribed safety distance-on the interpersonal distance established when people move within relatively dense crowds. Notably, we observe that the density should not be higher than 0.16 pedestrians per square meter (around 6 m2 per pedestrian) in order to guarantee an interpersonal distance of 1 m. Although the extrapolation of our findings to other more realistic scenarios is not straightforward, they can be used as a first approach to establish density restrictions in urban and architectonic spaces based on scientific evidence.

[Evaluation of function and limiting factors of gait disorder treatment in cerebral palsy: development of the Walking Abilities Levels Classification System]. / Evaluación funcional y de factores limitantes del tratamiento de los trastornos de la marcha en la parálisis cerebral infantil: desarrollo del sistema de clasificación de niveles de deambulación funcional.

INTRODUCTION: The Gross Motor Function Classification System has allowed us to stratificate cerebral palsy patients, according to their walking abilities. The lack of sensitivity about detecting changes and the absence of a global patient evaluation, justify the search of new pre-operative evaluation tools. AIMS: To present the Walking Abilities Levels Classification System (WALCS) and to show the first inter-observer agreement study that has been carried out. This system uses first a different pattern for ordering gait functional skills, and after that, evaluates the reversibility of the contextual factors that may limit the result of a gait disorder treatment. SUBJECTS AND METHODS: A new evaluation frame was built by an interdisciplinary team with an average professional experience of more than 15 years, initially focused as part of the pre-surgical patient evaluation. An inter-observer agreement study was held to gain the first insight of it. 14 participants studied the medical reports and gait lab video images of 10 cases. RESULTS: The kappa index was 0.76 for the walking ability level, 0.79 for the biological type, 0.69 psychological type and 0.64 social type of limiting factors. CONCLUSIONS: The WALCS offers a new evaluation frame gathering patient walking skills and limiting factors treatment. The initial inter-observer agreement rate endorsed more intra- and inter-studies in order to achieve a more robust validation.

TITLE: Evaluación funcional y de factores limitantes del tratamiento de los trastornos de la marcha en la parálisis cerebral infantil: desarrollo del sistema de clasificación de niveles de deambulación funcional.Introducción. El Gross Motor Function Classification System ha permitido estratificar, según su habilidad para caminar, a los pacientes que padecen parálisis cerebral infantil. La falta de sensibilidad en la detección de cambios y la ausencia de una evaluación del paciente en el contexto en el que se encuentra justifican la búsqueda de alternativas de evaluación pretratamiento. Objetivos. Presentar y mostrar la concordancia interobservador inicial del sistema de clasificación de niveles de deambulación funcional. Con él se evalúa la destreza para caminar y la necesidad de asistencia para realizar transferencias desde la silla de ruedas, y, posteriormente se analiza el escenario que la salud y el entorno del paciente ofrecen como condicionantes en la corrección de la marcha o la bipedestación asistida. Sujetos y métodos. Se describe un nuevo marco de evaluación, elaborado por un grupo interdisciplinar con más de 15 años de experiencia media, enfocado inicialmente a la toma de decisiones antes de un tratamiento quirúrgico. Como control interno, 14 participantes evaluaron la historia clínica y los vídeos de marcha de 10 casos. Resultados. Se alcanzó un índice kappa de acuerdo de 0,76 en niveles funcionales y de 0,79 en el tipo de escenario biológico, de 0,69 en el psicológico y de 0,64 en el social. Conclusiones. El sistema de clasificación de niveles de deambulación funcional ofrece un marco para la evaluación conjunta de la deambulación y de los factores limitantes en la eficacia de un tratamiento. La concordancia interobservador avala iniciar su validación.

Pedestrian collective motion in competitive room evacuation.

When a sizable number of people evacuate a room, if the door is not large enough, an accumulation of pedestrians in front of the exit may take place. This is the cause of emerging collective phenomena where the density is believed to be the key variable determining the pedestrian dynamics. Here, we show that when sustained contact among the individuals exists, density is not enough to describe the evacuation, and propose that at least another variable -such as the kinetic stress- is required. We recorded evacuation drills with different degrees of competitiveness where the individuals are allowed to moderately push each other in their way out. We obtain the density, velocity and kinetic stress fields over time, showing that competitiveness strongly affects them and evidencing patterns which have been never observed in previous (low pressure) evacuation experiments. For the highest competitiveness scenario, we detect the development of sudden collective motions. These movements are related to a notable increase of the kinetic stress and a reduction of the velocity towards the door, but do not depend on the density.

Flow and clogging of a sheep herd passing through a bottleneck.

We present an experimental study of a flock passing through a narrow door. Video monitoring of daily routines in a farm has enabled us to collect a sizable amount of data. By measuring the time lapse between the passage of consecutive animals, some features of the flow regime can be assessed. A quantitative definition of clogging is demonstrated based on the passage time statistics. These display broad tails, which can be fitted by power laws with a relatively large exponent. On the other hand, the distribution of burst sizes robustly evidences exponential behavior. Finally, borrowing concepts from granular physics and statistical mechanics, we evaluate the effect of increasing the door size and the performance of an obstacle placed in front of it. The success of these techniques opens new possibilities regarding their eventual extension to the management of human crowds.

[Epidemiological study of colorectal cancer in Zamora (Spain): a comparison between the years 1996 and 2003]. / Estudio epidemiológico del cáncer colorrectal en la provincia de Zamora: comparación entre los años 1996 y 2003.

INTRODUCTION: Colorectal cancer (CRC) is one of the most frequent tumors in Western countries. In Spain, widely different rates have been reported for distinct regions. AIM: To determine the epidemiological characteristics of CRC in the province of Zamora in 1996 and 2003 and to identify possible variations in these characteristics in each of these two years. MATERIAL AND METHODS: We performed a descriptive, retrospective study of all cases of CRC diagnosed in the Complejo Asistencial de Zamora in 1996 and 2003. RESULTS: In 1996, 146 patients were diagnosed with CRC, representing an unadjusted and adjusted incidence of 70.85 and 49.40 cases per 10(5) inhabitants. In 2003, 173 patients were diagnosed, representing an unadjusted and adjusted incidence of 86.89 and 58.12 cases per 105 inhabitants. The mean age at diagnosis was 72.08 years in 1996 and 71.15 years in 2003. The mean time to diagnosis was 3.37 months in 1996 and 4.11 in 2003. The mean time to diagnosis in 1996 was 4.35 months in rectal tumors and 2.87 months in colon tumors (p = 0.013). In 2003, the mean time to diagnosis was 4.70 months in rectal tumors and 3.84 months in colon tumors (p = 0.0749). The mean time to diagnosis was 3.56 and 3.83 months in patients living in urban areas and was 3.24 and 4.35 months in those living in rural areas in 1996 and 2003, respectively. More than 65% of the neoplasms were located in the rectum and sigmoid colon, with no differences between the two years. In 1996, 46.1% of the tumors were stage III or IV at diagnosis while in 2003, this percentage increased to 50.9%. In both years, the four basic health areas with the highest rates within the province were Aliste, Carbajales, Carballeda and Corrales. CONCLUSION: CRC is a highly frequent disease in the province of Zamora, especially in some of the western regions. The incidence of CRC was higher in 2003 than in 1996. Most of the tumors were located in the rectum and sigmoid colon. The time from symptom onset to diagnosis was prolonged. A high percentage of tumors were diagnosed in advanced stages.

[Psychosocial treatment of bipolar disorder]. / Tratamiento psicosocial del trastorno bipolar.

INTRODUCTION: The bipolar disorder is an important health problem. It presents with severe sintoms, and it tends to cronify. Although lithium has a prophilactic role, it has not controlled the development of severe psychosocial complications. It is necessary to study the psychosocial aspects related to this disorder, to define the areas in which the psychosocial interventions are needed, and the types of psychosocial approaches that can be useful. METHODS: Review of the literature, through MEDLINE database in the last fifteen years, about psychosocial complications of bipolar disorder and its treatment. RESULTS: Many articles emphasize the important psychosocial deficits that appear in patients with bipolar disorder. These deficits concern to all social functions and persist for a long time. The patients are more vulnerable to stressing events, that can have devastating consecuences. The articles report the influence in the evolution and prognosis of this disorder, by the comorbidity of other medical and pschiatric problems. The psychotherapeutical interventions can be of interest to treat the social aspects that lithium fails to control. CONCLUSIONS: Our approach would tend to integrate in the clinical practice both, the biomedical and psychosocial theories. This permits an integral treatment of all the factors implicated in the genesis, maintenance, and consecuences of the mental disorders.