896 research outputs found
Hewlett Packard Enterprise
Para mi proyecto PAP2 del periodo de verano 2023, trabajé en la empresa huésped HPE aquí en Guadalajara. Mi rol como becario es en un proceso operativo, pero tuve la oportunidad de conocer otras áreas de la empresa y obtuve mejor panorama de lo que hacía. Después de la sesión introductoria al Proyecto de Aplicación Profesional y la presentación de los temas del curso, decidí trabajar en una propuesta de mejora de procesos y automatización. Vi una oportunidad clara de diseñar un algoritmo que realizara las actividades que hacía una persona.
Presenté mi idea y las necesidades del PAP con mi supervisor y me aprobó la iniciativa, básicamente mi intención era reemplazar la actividad manual de generar reportes y que lo hiciera un flujo automatizado en una herramienta llamada power automate. Después pensé que para realmente proponer una mejora debía de llevar a cabo un análisis como he trabajado durante la carrera y así definí el alcance de este proyecto en el que participé como administrador y desarrollador.
Al concluir el proyecto, el flujo automatizado cumplió las expectativas, sin embargo lo más valioso fue el análisis de riesgos y oportunidades con el que se desarrollará un proyecto de mejora con más personas involucradas.ITESO, A.C
Probing microscopic origins of confined subdiffusion by first-passage observables
Subdiffusive motion of tracer particles in complex crowded environments, such
as biological cells, has been shown to be widepsread. This deviation from
brownian motion is usually characterized by a sublinear time dependence of the
mean square displacement (MSD). However, subdiffusive behavior can stem from
different microscopic scenarios, which can not be identified solely by the MSD
data. In this paper we present a theoretical framework which permits to
calculate analytically first-passage observables (mean first-passage times,
splitting probabilities and occupation times distributions) in disordered media
in any dimensions. This analysis is applied to two representative microscopic
models of subdiffusion: continuous-time random walks with heavy tailed waiting
times, and diffusion on fractals. Our results show that first-passage
observables provide tools to unambiguously discriminate between the two
possible microscopic scenarios of subdiffusion. Moreover we suggest experiments
based on first-passage observables which could help in determining the origin
of subdiffusion in complex media such as living cells, and discuss the
implications of anomalous transport to reaction kinetics in cells.Comment: 21 pages, 3 figures. Submitted versio
Membrane shape as a reporter for applied forces
Recent advances have enabled 3-dimensional reconstructions of biological structures in vivo, ranging in size and complexity from single proteins to multicellular structures. In particular, tomography and confocal microscopy have been exploited to capture detailed 3-dimensional conformations of membranes in cellular processes ranging from viral budding and organelle maintenance to phagocytosis. Despite the wealth of membrane structures available, there is as yet no generic, quantitative method for their interpretation. We propose that by modeling these observed biomembrane shapes as fluid lipid bilayers in mechanical equilibrium, the externally applied forces as well as the pressure, tension, and spontaneous curvature can be computed directly from the shape alone. To illustrate the potential power of this technique, we apply an axial force with optical tweezers to vesicles and explicitly demonstrate that the applied force is equal to the force computed from the membrane conformation
Domain Growth Kinetics in a Cell-sized Liposome
We investigated the kinetics of domain growth on liposomes consisting of a
ternary mixture (unsaturated phospholipid, saturated phospholipid, and
cholesterol) by temperature jump. The domain growth process was monitored by
fluorescence microscopy, where the growth was mediated by the fusion of domains
through the collision. It was found that an average domain size r develops with
time t as r ~ t^0.15, indicating that the power is around a half of the
theoretical expectation deduced from a model of Brownian motion on a
2-dimensional membrane. We discuss the mechanism of the experimental scaling
behavior by considering the elasticity of the membrane
Papers please: Predictive factors of national and international attitudes toward immunity and vaccination passports. Online representative surveys
BACKGROUND: In response to the COVID-19 pandemic, countries are introducing digital passports that allow citizens to return to normal activities if they were previously infected with (immunity passport) or vaccinated against (vaccination passport) SARS-CoV-2. To be effective, policy decision-makers must know whether these passports will be widely accepted by the public and under what conditions. This study focuses attention on immunity passports, as these may prove useful in countries both with and without an existing COVID-19 vaccination program; however, our general findings also extend to vaccination passports. OBJECTIVE: We aimed to assess attitudes toward the introduction of immunity passports in six countries, and determine what social, personal, and contextual factors predicted their support. METHODS: We collected 13,678 participants through online representative sampling across six countries—Australia, Japan, Taiwan, Germany, Spain, and the United Kingdom—during April to May of the 2020 COVID-19 pandemic, and assessed attitudes and support for the introduction of immunity passports. RESULTS: Immunity passport support was moderate to low, being the highest in Germany (775/1507 participants, 51.43%) and the United Kingdom (759/1484, 51.15%); followed by Taiwan (2841/5989, 47.44%), Australia (963/2086, 46.16%), and Spain (693/1491, 46.48%); and was the lowest in Japan (241/1081, 22.94%). Bayesian generalized linear mixed effects modeling was used to assess predictive factors for immunity passport support across countries. International results showed neoliberal worldviews (odds ratio [OR] 1.17, 95% CI 1.13-1.22), personal concern (OR 1.07, 95% CI 1.00-1.16), perceived virus severity (OR 1.07, 95% CI 1.01-1.14), the fairness of immunity passports (OR 2.51, 95% CI 2.36-2.66), liking immunity passports (OR 2.77, 95% CI 2.61-2.94), and a willingness to become infected to gain an immunity passport (OR 1.6, 95% CI 1.51-1.68) were all predictive factors of immunity passport support. By contrast, gender (woman; OR 0.9, 95% CI 0.82-0.98), immunity passport concern (OR 0.61, 95% CI 0.57-0.65), and risk of harm to society (OR 0.71, 95% CI 0.67-0.76) predicted a decrease in support for immunity passports. Minor differences in predictive factors were found between countries and results were modeled separately to provide national accounts of these data. CONCLUSIONS: Our research suggests that support for immunity passports is predicted by the personal benefits and societal risks they confer. These findings generalized across six countries and may also prove informative for the introduction of vaccination passports, helping policymakers to introduce effective COVID-19 passport policies in these six countries and around the world
Curvature-coupling dependence of membrane protein diffusion coefficients
We consider the lateral diffusion of a protein interacting with the curvature
of the membrane. The interaction energy is minimized if the particle is at a
membrane position with a certain curvature that agrees with the spontaneous
curvature of the particle. We employ stochastic simulations that take into
account both the thermal fluctuations of the membrane and the diffusive
behavior of the particle. In this study we neglect the influence of the
particle on the membrane dynamics, thus the membrane dynamics agrees with that
of a freely fluctuating membrane. Overall, we find that this curvature-coupling
substantially enhances the diffusion coefficient. We compare the ratio of the
projected or measured diffusion coefficient and the free intramembrane
diffusion coefficient, which is a parameter of the simulations, with analytical
results that rely on several approximations. We find that the simulations
always lead to a somewhat smaller diffusion coefficient than our analytical
approach. A detailed study of the correlations of the forces acting on the
particle indicates that the diffusing inclusion tries to follow favorable
positions on the membrane, such that forces along the trajectory are on average
smaller than they would be for random particle positions.Comment: 16 pages, 8 figure
The molecular epidemiology of human immunodeficiency virus type 1 in six cities in Britain and Ireland
The authors sequenced the p17 coding regions of the gag gene from 211 patients infected either through injecting drug use (IDU) or by sexual intercourse between men from six cities in Scotland, N. England, N. Ireland, and the Republic of Ireland. All sequences were of subtype 5. Phylogenetic analysis revealed substantial heterogeneity in the sequences from homosexual men. In contrast, sequence from over 80% of IDUs formed a relatively tight cluster, distinct both from those of published isolates and of the gay men. There was no large-scale clustering of sequences by city in either risk group, although a number of close associations between pairs of individuals were observed. From the known date of the HIV-1 epidemic among IDUs in Edinburgh, the rate of sequence divergence at synonymous sites is estimated to be about 0.8%. On this basis it has been estimated that the date of divergence of the sequences among homosexual men to be about 1975, which may correspond to the origin of the B subtype epidemic
Cell jamming, stratification and p63 expression in cultivated human corneal epithelial cell sheets
Corneal limbal epithelial stem cell transplantation using cultivated human corneal epithelial cell sheets has been used successfully to treat limbal stem cell deficiencies. Here we report an investigation into the quality of cultivated human corneal epithelial cell sheets using time-lapse imaging of the cell culture process every 20 minutes over 14 days to ascertain the level of cell jamming, a phenomenon in which cells become smaller, more rounded and less actively expansive. In parallel, we also assessed the expression of p63, an important corneal epithelial stem cell marker. The occurrence of cell jamming was variable and transient, but was invariably associated with a thickening and stratification of the cell sheet. p63 was present in all expanding cell sheets in the first 9 days of culture, but it’s presence did not always correlate with stratification of the cell sheet. Nor did p63 expression necessarily persist in stratified cell sheets. An assessment of cell jamming, therefore, can shed significant light on the quality and regenerative potential of cultivated human corneal epithelial cell sheets
On logical gates in precipitating medium: cellular automaton model
We study a two-dimensional semi-totalistic binary cell-state cellular
automaton, which imitates a reversible precipitation in an abstract chemical
medium. The systems exhibits a non-trivial growth and nucleation. We
demonstrate how basic computational operation can be realized in the system
when the propagation of the growing patterns is self-restricted by stationary
localizations. We show that precipitating patterns of different morphology
compete between each other and thus implement serial and non-serial logical
gates
The Localization Transition of the Two-Dimensional Lorentz Model
We investigate the dynamics of a single tracer particle performing Brownian
motion in a two-dimensional course of randomly distributed hard obstacles. At a
certain critical obstacle density, the motion of the tracer becomes anomalous
over many decades in time, which is rationalized in terms of an underlying
percolation transition of the void space. In the vicinity of this critical
density the dynamics follows the anomalous one up to a crossover time scale
where the motion becomes either diffusive or localized. We analyze the scaling
behavior of the time-dependent diffusion coefficient D(t) including corrections
to scaling. Away from the critical density, D(t) exhibits universal
hydrodynamic long-time tails both in the diffusive as well as in the localized
phase.Comment: 13 pages, 7 figures
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