517 research outputs found
Chemical and hydrodynamic alignment of an enzyme
Motivated by the implications of the complex and dynamic modular geometry of
an enzyme on its motion, we investigate the effect of combining long-range
internal and external hydrodynamic interactions due to thermal fluctuations
with short-range surface interactions. An asymmetric dumbbell consisting of two
unequal subunits, in a nonuniform suspension of a solute with which it
interacts via hydrodynamic interactions as well as non-contact surface
interactions, is shown to have two alignment mechanisms due to the two types of
interactions. In addition to alignment, the chemical gradient results in a
drift velocity that is modified by hydrodynamic interactions between the
constituents of the enzyme.Comment: 7+4 pages, 3 figure
Estudio piloto para una investigación descriptiva sobre los programas afectivo-sexuales de los colegios de Madrid
Trabajo fin de grado en EnfermerÃaObjetivos. Analizar las caracterÃsticas de los programas afectivo-sexuales de diferentes colegios de Madrid.
Material y métodos. Estudio piloto descriptivo transversal, efectuado en colegios de Educación Primaria en los distritos Salamanca, Retiro y San Blas-Canillejas del Municipio de Madrid. Se seleccionaron mediante un muestreo no aleatorio intencional. Se recogió la información a través de un cuestionario para obtener los valores de los indicadores y su frecuencia. Mediante tablas de distribución se calcularán frecuencias y porcentajes analizando las diferentes variables por separado. Los datos cuantitativos se analizarán mediante la media, desviación tÃpica, mediana, mÃnimo y máximo. Los datos cualitativos se describirán con frecuencias absolutas y porcentajes.
Resultados. No se pudieron obtener resultados para el estudio debido a que los colegios no participaron en el estudio, asimismo los resultados no serÃa extrapolables debido al método de muestreo y el tamaño muestral.
Conclusiones. Al no participar en el estudio queda patente la falta de implicación de los colegios, serÃa conveniente alentar a los centros educativos a participar en estudios que impulsen la igualdad de género. SerÃa conveniente seguir con estudios descriptivos para profundizar en la situación actual.Objective. To analyze affective-sexual education programs features of some of the Madrid’s schools.
Material and methods. Descriptive transversal pilot project, made in Primary Education schools of the Retiro, Salamanca and San Blas-Canillejas districts, which were selected through a non-random intentional sampling. Information has been gathered using a questionnaire designed to obtain indicator’s values and frequency. Through tables of distribution, frequencies and percentages will be calculated, analyzing separately different variables. Quantitative data will be analyzed through average, typical deviation, median, minimum and maximum, while qualitative ones will be described with absolute frequencies and percentages.
Results. It was not possible to obtain result for the study, owing to lack of cooperation from the schools; anyway, results would not be translatable because of the sample size and the sampling method used.
Conclusions. The fact that the schools did not collaborate in the study makes it clear that schools feel scarcely involved with this particular subject. It would be advisable to encourage education centers to take part in studies promoting gender equality. It would also be desirable to go ahead with descriptive studies which dig deeply in the current situation
Realització d'un portal web d'oci i cultura del Maresme
La comarca del Maresme és molt activa en matèria d'oci i cultura,però els mitjans locals no més es fan ressò del que es fa a la seva localitat, i aquells que tenen un carà cter més comarcal opten per donar més importà ncia a temes polÃtics o esportius, deixant una mica de banda la cultura i l'oci. Els mitjans de comunicació generalistes, ja siguin digital o en format paper,han de ser una selecció de les notÃcies que succeeixen i moltes queden fora. A la comarca no hi ha cap portal cultural que es faci ressò de tots els actes, events i espectacles culturals que es duen a terme per entitats, institucions, empreses i associacions. La idea principal del meu Projecte Final de Carrera és omplir aquest buit i crear un portal web d'oci i cultura de la comarca del Maresme amb articles d'allò que es fa i s'ha fet, crÃtiques, enriquit amb fotografÃes i videos
Cuidados y bienestar : el trabajo sanitario femenino en respuesta a la «cuestión social» (1857-1936)
Se analiza la práctica cuidadora ejercida en España por las matronas, enfermeras y practicantas en el periodo de 1857 hasta 1936. El estudio se articula con la perspectiva feminista a través de la microhistoria, según la identidad que dichos colectivos tuvieron en la provincia de AlmerÃa. Se ha conectado con el discurso androcéntrico y actitudes sociales hacia ellas para analizar el desenvolvimiento de las mujeres, comparándolas con otras cuidadoras de la geografÃa nacional. Las distintas categorÃas de cuidados que llevaron a cabo como medio de suavizar la «cuestión social» son el telón de fondo que nos revela la respuesta a la pregunta de en qué medida las matronas, practicantas y enfermeras de aquella época contribuyeron a la salud de la ciudadanÃa y al bienestar social
Realització d'un portal web d'oci i cultura del Maresme
La comarca del Maresme és molt activa en matèria d’oci i cultura, però els mitjans locals només es fan ressò del que es fa a la seva localitat, i aquells que tenen un carà cter més comarcal opten per donar més importà ncia a temes polÃtics o esportius, deixant una mica de banda la cultura i l’oci. Els mitjans de comunicació generalistes, ja siguin digital o en format paper, han de fer una selecció de les noticies que succeeixen i moltes queden fora. A la comarca no hi ha cap portal cultural que es faci ressò de tots els actes, events i espectacles culturals que es duen a terme per entitats, institucions, empreses i associacions. La idea principal del meu Projecte Final de Carrera és omplir aquest buit i crear un portal web d’oci i cultura de la comarca del Maresme amb articles d’allò del que es fa i s’ha fet, crÃtiques, enriquit amb fotografies i vÃdeos
Active phase separation in mixtures of chemically interacting particles
We theoretically study mixtures of chemically-interacting particles, which
produce or consume a chemical to which they are attracted or repelled, in the
most general case of many coexisting species. We find a new class of active
phase separation phenomena in which the nonequilibrium chemical interactions
between particles, which break action-reaction symmetry, can lead to separation
into phases with distinct density and stoichiometry. Due to the generic nature
of our minimal model, our results shed light on the underlying fundamental
principles behind nonequilibrium self-organization of cells and bacteria,
catalytic enzymes, or phoretic colloids.Comment: Main Text (5 pages, 3 figures) plus Supplemental Material (8 pages, 4
figures). The associated movies 1-12 can be found at
http://www.ds.mpg.de/LMP/arxiv19010902
Diffusion and steady state distributions of flexible chemotactic enzymes
Many experiments in recent years have reported that, when exposed to their
corresponding substrate, catalytic enzymes undergo enhanced diffusion as well
as chemotaxis (biased motion in the direction of a substrate gradient). Among
other possible mechanisms, in a number of recent works we have explored several
passive mechanisms for enhanced diffusion and chemotaxis, in the sense that
they require only binding and unbinding of the enzyme to the substrate rather
than the catalytic reaction itself. These mechanisms rely on conformational
changes of the enzyme due to binding, as well as on phoresis due to non-contact
interactions between enzyme and substrate. Here, after reviewing and
generalizing our previous findings, we extend them in two different ways. In
the case of enhanced diffusion, we show that an exact result for the long-time
diffusion coefficient of the enzyme can be obtained using generalized Taylor
dispersion theory, which results in much simpler and transparent analytical
expressions for the diffusion enhancement. In the case of chemotaxis, we show
that the competition between phoresis and binding-induced changes in diffusion
results in non-trivial steady state distributions for the enzyme, which can
either accumulate in or be depleted from regions with a specific substrate
concentration.Comment: 16 pages, 2 figure
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