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1.
Phys Rev Lett ; 132(20): 208301, 2024 May 17.
Article in English | MEDLINE | ID: mdl-38829083

ABSTRACT

When two active Brownian particles collide, they slide along each other until they can continue their free motion. For persistence lengths much larger than the particle diameter, the directors do not change, but the collision can be modeled as producing a net displacement on the particles compared to their free motion in the absence of the encounter. With these elements, a Boltzmann-Enskog-like kinetic theory is built. A linear stability analysis of the homogeneous state predicts a density instability resulting from the effective velocity reduction of tagged particles predicted by the theory.

2.
Acta bioeth ; 30(1)jun. 2024.
Article in Spanish | LILACS-Express | LILACS | ID: biblio-1556621

ABSTRACT

Este artículo explora los desafíos que presenta a la bioética la emergencia del transhumanismo en Occidente. La exploración es abordada desde una perspectiva de investigación genealógica, que tiene por objetivo preguntarse por las condiciones de inteligibilidad del transhumanismo y a partir de allí analizar sus impactos en la actualización de un debate central en bioética, a saber, los límites a la manipulación de la vida humana. El transhumanismo, habitando la crisis del humanismo que le antecede y compele, reactualiza la cuestión de la condición humana presentando una línea argumental que al menos autoriza a formular de nuevo la pregunta límite: ¿podemos, o acaso debemos, ir más allá de lo humano?.


This article explores the challenges presented to bioethics by the emergence of transhumanism in the West. The exploration is approached from a genealogical research perspective. A genealogical investigation aims to question the conditions of intelligibility of transhumanism and from there analyze its impacts on the updating of a central debate in bioethics, namely: the limits to the manipulation of human life. Transhumanism, inhabiting the crisis of humanism that precedes and compels it, updates the issue of the human condition by presenting a line of argument that at least authorizes to formulate again the limit question: can we/should we go beyond the human?.


Este artigo explora os desafios apresentados à bioética pela emergência do transumanismo no Ocidente. A exploração é abordada a partir de uma perspectiva de pesquisa genealógica. Uma investigação genealógica visa indagar sobre as condições de inteligibilidade do transumanismo e a partir daí analisar seus impactos na atualização de um debate central na bioética, a saber: os limites à manipulação da vida humana. O transumanismo, habitando a crise do humanismo que o precede e o compele, atualiza a questão da condição humana ao apresentar uma linha de argumentação que ao menos nos autoriza a formular novamente a questão límite: podemos ou devemos ir além do que é humano?.

3.
BMJ Open ; 13(6): e065009, 2023 06 23.
Article in English | MEDLINE | ID: mdl-37355266

ABSTRACT

INTRODUCTION: Leptospirosis is a globally distributed zoonotic and environmentally mediated disease that has emerged as a major health problem in urban slums in developing countries. Its aetiological agent is bacteria of the genus Leptospira, which are mainly spread in the urine of infected rodents, especially in an environment where adequate sanitation facilities are lacking, and it is known that open sewers are key transmission sources of the disease. Therefore, we aim to evaluate the effectiveness of a simplified sewerage intervention in reducing the risk of exposure to contaminated environments and Leptospira infection and to characterise the transmission mechanisms involved. METHODS AND ANALYSIS: This matched quasi-experimental study design using non-randomised intervention and control clusters was designed to assess the effectiveness of an urban simplified sewerage intervention in the low-income communities of Salvador, Brazil. The intervention consists of household-level piped sewerage connections and community engagement and public involvement activities. A cohort of 1400 adult participants will be recruited and grouped into eight clusters consisting of four matched intervention-control pairs with approximately 175 individuals in each cluster in baseline. The primary outcome is the seroincidence of Leptospira infection assessed through five serological measurements: one preintervention (baseline) and four postintervention. As a secondary outcome, we will assess Leptospira load in soil, before and after the intervention. We will also assess Leptospira exposures before and after the intervention, through transmission modelling, accounting for residents' movement, contact with flooding, contaminated soil and water, and rat infestation, to examine whether and how routes of exposure for Leptospira change following the introduction of sanitation. ETHICS AND DISSEMINATION: This study protocol has been reviewed and approved by the ethics boards at the Federal University of Bahia and the Brazilian National Research Ethics Committee. Results will be disseminated through peer-reviewed publications and presentations to implementers, researchers and participating communities. TRIAL REGISTRATION NUMBER: Brazilian Clinical Trials Registry (RBR-8cjjpgm).


Subject(s)
Leptospira , Leptospirosis , Animals , Rats , Brazil/epidemiology , Leptospirosis/epidemiology , Leptospirosis/prevention & control , Poverty , Soil
4.
Soft Matter ; 17(46): 10479-10491, 2021 Dec 01.
Article in English | MEDLINE | ID: mdl-34750600

ABSTRACT

Active matter deals with systems whose particles consume energy at the individual level in order to move. To unravel features such as the emergence of collective structures, several models have been suggested, such as the on-lattice model of run-and-tumble particles implemented via the persistent exclusion process (PEP). In our work, we study a one-dimensional system of run-and-tumble repulsive or attractive particles, both on-lattice and off-lattice. Additionally, we implement cluster motility dynamics in the on-lattice case (since in the off-lattice case, cluster motility arises from the individual particle dynamics). While we observe important differences between discrete and continuous dynamics, few common features are of particular importance. Increasing particle density drives aggregation across all different systems explored. For non-attractive particles, the effects of particle activity on aggregation are largely independent of the details of the dynamics. In contrast, once attractive interactions are introduced, the steady-state, which is completely determined by the interplay between these and the particles' activity, becomes highly dependent on the details of the dynamics.


Subject(s)
Motion
5.
Phys Rev E ; 102(5-1): 052904, 2020 Nov.
Article in English | MEDLINE | ID: mdl-33327089

ABSTRACT

A collisional model of a confined quasi-two-dimensional granular mixture is considered to analyze homogeneous steady states. The model includes an effective mechanism to transfer the kinetic energy injected by vibration in the vertical direction to the horizontal degrees of freedom of grains. The set of Enskog kinetic equations for the velocity distribution functions of each component is derived first to analyze the homogeneous state. As in the one-component case, an exact scaling solution is found where the time dependence of the distribution functions occurs entirely through the granular temperature T. As expected, the kinetic partial temperatures T_{i} of each component are different and, hence, energy equipartition is broken down. In the steady state, explicit expressions for the temperature T and the ratio of partial kinetic temperatures T_{i}/T_{j} are obtained by considering Maxwellian distributions defined at the partial temperatures T_{i}. The (scaled) granular temperature and the temperature ratios are given in terms of the coefficients of restitution, the solid volume fraction, the (scaled) parameters of the collisional model, and the ratios of mass, concentration, and diameters. In the case of a binary mixture, the theoretical predictions are exhaustively compared with both direct simulation Monte Carlo and molecular dynamics simulations with a good agreement. The deviations are identified to be originated in the non-Gaussianity of the velocity distributions and on microsegregation patterns, which induce spatial correlations not captured in the Enskog theory.

7.
Article in English | MEDLINE | ID: mdl-25615082

ABSTRACT

The shear viscosity in the dilute regime of a model for confined granular matter is studied by simulations and kinetic theory. The model consists on projecting into two dimensions the motion of vibrofluidized granular matter in shallow boxes by modifying the collision rule: besides the restitution coefficient that accounts for the energy dissipation, there is a separation velocity that is added in each collision in the normal direction. The two mechanisms balance on average, producing stationary homogeneous states. Molecular dynamics simulations show that in the steady state the distribution function departs from a Maxwellian, with cumulants that remain small in the whole range of inelasticities. The shear viscosity normalized with stationary temperature presents a clear dependence with the inelasticity, taking smaller values compared to the elastic case. A Boltzmann-like equation is built and analyzed using linear response theory. It is found that the predictions show an excellent agreement with the simulations when the correct stationary distribution is used but a Maxwellian approximation fails in predicting the inelasticity dependence of the viscosity. These results confirm that transport coefficients depend strongly on the mechanisms that drive them to stationary states.

8.
Article in English | MEDLINE | ID: mdl-23496507

ABSTRACT

Confined granular fluids, placed in a shallow box that is vibrated vertically, can achieve homogeneous stationary states due to energy injection mechanisms that take place throughout the system. These states can be stable even at high densities and inelasticities allowing for a detailed analysis of the hydrodynamic modes that govern the dynamics of granular fluids. By analyzing the decay of the time correlation functions it is shown that there is a crossover from a quasielastic regime in which energy evolves as a slow mode to an inelastic regime with energy slaved to the other conserved fields. The two regimes have well differentiated transport properties and in the inelastic regime the dynamics can be described by a reduced hydrodynamics with modified longitudinal viscosity and sound speed. The crossover between the two regimes takes place at a wave vector that is proportional to the inelasticity. A two-dimensional granular model, with collisions that mimic the energy transfers that take place in a confined system, is studied by means of microscopic simulations. The results show excellent agreement with the theoretical framework and allow validation of hydrodynamiclike models.


Subject(s)
Colloids/chemistry , Models, Chemical , Models, Molecular , Solutions/chemistry , Computer Simulation , Hydrodynamics
9.
Mediciego ; 17(Supl. 1)jul. 2011. tab
Article in Spanish | CUMED | ID: cum-47250

ABSTRACT

Se realizó un estudio analítico transversal en pre-escolares de 5 años de edad, de ambos sexos, de los círculos infantiles de las áreas de salud de las Clínicas Estomatológicas Docentes de los municipios Ciego de Ávila (209 pre-escolares) y Chambas (190 pre-escolares), provincia Ciego de Ávila, en el curso escolar 2009-10, para determinar y comparar la relación existente entre el tiempo de lactancia materna, la aparición de los factores de riesgo hábitos bucales deformantes y las alteraciones de la oclusión temporal. Se llega a la conclusión de que en Ciego de Ávila menos de la mitad de los pre-escolares presentaron el factor de riesgo hábitos bucales deformantes, mientras en Chambas fueron las tres cuartas partes. Los pre-escolares que lactaron menos de cuatro meses presentaron la mayor cantidad de hábitos en todos sus tipos. En Ciego, la asociación de hábitos y en Chambas la succión digital, se relacionaron más a las alteraciones. El tiempo de lactancia materna menor de cuatro meses fue considerado factor de riesgo en la aparición de hábitos y alteraciones oclusales(AU)


An analytic and transversal study was carried out in pre-school children 5 years of age, of both sexes, children's centers in health areas of teaching dental clinic of Ciego de Avila municipalities (209 pre-school) and Chambas (190 pre-school), Ciego de Avila province in 2009-10 school year to determine and compare the relationship between time of breastfeeding, risk factors like deforming oral habits and changes in temporary occlusion. It concludes that in Ciego de Ávila less than half preschoolers had risk factor like deforming oral habits, while in Chambas were three quarter parts. Preschoolers who breastfeed less than four months had more amount of habits in all its types. The habits Association in Ciego de Avila and digital suction in Chambas are more related to changes. The breastfeeding for less than four months was considered a risk factor in the development of habits and occlusal disorders(AU)


Subject(s)
Humans , Male , Female , Child, Preschool , Breast Feeding/adverse effects , Risk Factors , Malocclusion/etiology , Schools, Nursery , Cross-Sectional Studies
10.
Mediciego ; 17(Supl. 1)jul. 2011. tab
Article in Spanish | LILACS | ID: lil-616721

ABSTRACT

Se realizó un estudio analítico transversal en pre-escolares de 5 años de edad, de ambos sexos, de los círculos infantiles de las áreas de salud de las Clínicas Estomatológicas Docentes de los municipios Ciego de Ávila (209 pre-escolares) y Chambas (190 pre-escolares), provincia Ciego de Ávila, en el curso escolar 2009-10, para determinar y comparar la relación existente entre el tiempo de lactancia materna, la aparición de los factores de riesgo hábitos bucales deformantes y las alteraciones de la oclusión temporal. Se llega a la conclusión de que en Ciego de Ávila menos de la mitad de los pre-escolares presentaron el factor de riesgo hábitos bucales deformantes, mientras en Chambas fueron las tres cuartas partes. Los pre-escolares que lactaron menos de cuatro meses presentaron la mayor cantidad de hábitos en todos sus tipos. En Ciego, la asociación de hábitos y en Chambas la succión digital, se relacionaron más a las alteraciones. El tiempo de lactancia materna menor de cuatro meses fue considerado factor de riesgo en la aparición de hábitos y alteraciones oclusales.


An analytic and transversal study was carried out in pre-school children 5 years of age, of both sexes, children's centers in health areas of teaching dental clinic of Ciego de Avila municipalities (209 pre-school) and Chambas (190 pre-school), Ciego de Avila province in 2009-10 school year to determine and compare the relationship between time of breastfeeding, risk factors like deforming oral habits and changes in temporary occlusion. It concludes that in Ciego de Ávila less than half preschoolers had risk factor like deforming oral habits, while in Chambas were three quarter parts. Preschoolers who breastfeed less than four months had more amount of habits in all its types. The habits Association in Ciego de Avila and digital suction in Chambas are more related to changes. The breastfeeding for less than four months was considered a risk factor in the development of habits and occlusal disorders.


Subject(s)
Humans , Male , Female , Child, Preschool , Breast Feeding , Malocclusion/etiology , Risk Factors , Cross-Sectional Studies
11.
J Appl Clin Med Phys ; 12(2): 3330, 2011 Jan 30.
Article in English | MEDLINE | ID: mdl-21587175

ABSTRACT

The Brazilian Institute of Radiation Protection and Dosimetry (IRD/CNEN) carried out quality assurance regulatory audits in Brazilian radiotherapy facilities from 1995 to 2007. In this work, the set of data collected from 195 radiotherapy facilities that use high-energy photon beams are analyzed. They include results from audits in linear electron accelerators and/or Co-60 units. The inspectors of IRD/CNEN performed the dosimetry of high-energy radiotherapy photon beams according to the IAEA dosimetry protocols TRS 277 and TRS 398, and the values of measurements were compared to stated values. Other aspects of radiological protection were checked during on-site audits such as calibration certification of clinical dosimeters and portable monitors, existence and use of check source, use of barometer and thermometer, individual dose registry and training of staff. It was verified that no check source was available in 38% of the visited facilities; the training of personnel was not adequate in 9% of the facilities and the registry of accumulated individual doses was not being done in 6% of the facilities. Measurements of absorbed dose have indicated deviations in the range ± 3% for 67.6% of the cobalt-60 units and 79.6% of medical linear accelerators; 18.5% of Co-60 irradiators and 9.6% of linear accelerators presented deviations in the range 3% < δ ≤ 5%. Finally, 13.9% of Co-60 facilities and 10.8% of linear accelerator facilities presented dosimetry deviations above 5%. The effort in dosimetric quality control performed by IRD/CNEN audits has yielded positive changes that make radiation treatment facilities more reliable.


Subject(s)
Radiometry/methods , Radiotherapy, High-Energy/methods , Brazil , Calibration , Cobalt Isotopes/chemistry , Humans , Particle Accelerators , Quality Control , Radiation Oncology/standards , Radiation Protection/methods , Radiotherapy Dosage , Radiotherapy, High-Energy/standards , Safety , Thermometers
12.
J. bras. neurocir ; 22(3): 124-127, 2011.
Article in English | LILACS | ID: lil-608876

ABSTRACT

O mieloma múltiplo em sistema nervoso central (SNC) é uma condição extremamente rara, sendo descrita em pouco mais de 100 casos na literatura. Neste artigo, os autores descrevem o caso de uma paciente do sexo feminino de 55 anos, submetida a transplante autólogo de medula óssea, e, mais tarde, à biopsia de tecido cerebral com confirmação imunohistoquímica, revelando tecido cerebral infiltrado por grande quantidade de plasmócitos, compatível com a história clínica de mieloma múltiplo. A paciente foi então submetida a radioterapia adjuvante em SNC, permanecendo em acompanhamento ambulatorial com a oncologia clínica e utilizando pamidronato dissódico mensal. Mesmo sendo uma afecção incurável, a radioterapia mostrou-se importante para o controle local.


Subject(s)
Humans , Female , Adult , Central Nervous System , Multiple Myeloma , Neoplasm Metastasis , Plasma Cells , Radiotherapy
13.
Mediciego ; 12(2)Dic. 2006. ilus, tab
Article in Spanish | CUMED | ID: cum-32829

ABSTRACT

Producto de la complejidad de la materia "Electrocardiografía", se elaboró un software educativo con el cual se aporta un conocimiento básico general sobre el tema, el contenido distribuido por tópicos garantiza la búsqueda rápida de información y visualización de esquemas, acercarse a una nueva bibliografía y autoevaluarse. El mismo fue validado en un grupo de estudiantes de la carrera de Medicina, de los cuales un grupo se entrenó y observó el medio y otro no desarrolló este método. El análisis estadístico de los resultados a través de la prueba “t de Student" mostró diferencias estadísticamente significativas (p < 0.05) de los valores de la puntuación general entre ambos grupos, así como de las temáticas de reconocimiento de accidentes en un electrocardiograma, cálculo de la frecuencia cardiaca y determinación de la posición de electrodos. (AU)


Subject(s)
Electrocardiography , Software , Software Validation
14.
Mediciego ; 12(2)dic. 2006. ilus, tab
Article in Spanish | LILACS | ID: lil-488127

ABSTRACT

Producto de la complejidad de la materia "Electrocardiografía", se elaboró un software educativo con el cual se aporta un conocimiento básico general sobre el tema, el contenido distribuido por tópicos garantiza la búsqueda rápida de información y visualización de esquemas, acercarse a una nueva bibliografía y autoevaluarse. El mismo fue validado en un grupo de estudiantes de la carrera de Medicina, de los cuales un grupo se entrenó y observó el medio y otro no desarrolló este método. El análisis estadístico de los resultados a través de la prueba “t de Student" mostró diferencias estadísticamente significativas (p < 0.05) de los valores de la puntuación general entre ambos grupos, así como de las temáticas de reconocimiento de accidentes en un electrocardiograma, cálculo de la frecuencia cardiaca y determinación de la posición de electrodos.


Due to the complexity of the subject mather electrocardiography we made an educative software which provides a comprenhensive basic knowledge on the topic; the content was distributed by topic which guarantees the guick search , vizualization of graphics, get closer to a new bibliography and self-test. It was validated by a group of students of the Medicine carreer; our group was trained and observed the means where as the other did not use the method (student) test demonstrated significant statistical differences (p<0.05) of the values of the general score between both groups, as well as in the themes of recognition of accidents in an ECG, computation of thye heart rate and the assessment of the position of electrodes.


Subject(s)
Electrocardiography , Software , Software Validation
15.
MediCiego ; 6(1): 31-34, ene.-jun. 2000.
Article in Spanish | CUMED | ID: cum-19245

ABSTRACT

El desafío que hoy se abre es de una Universidad que busca la creatividad; la educaciòn a distancia ha demostrado que puede combinar la ampliación de la cobertura, para favoreser un mayor acceso a la educaciòn médica postgraduada, con proceso de calidad a partir de un proyecto pedagógico de la Universidad Virtual de la Salud (UVS). Con este trabajo pretendemos presentar las experiencias de la la UVS de Ciego de Avila. (AU)


Subject(s)
Computer Literacy
16.
Rev cuba ortod ; 12(2): 96-101, ene.- jun. 1997. tab
Article in Spanish | CUMED | ID: cum-10580

ABSTRACT

Se realizó un estudio epidemiológico descriptivo transversal, en una muestra representativa de 896 niños de 0 a 14 años de edad del área de salud Florencia, en la Provincia Ciego de Avila, durante el curso escolar 1995-1995, para conocer el diagnóstico ortodóntico de esta población. Se encontró una prevalencia de maloclusión entre 25,0 y 30,8 por ciento, la cual fue significativamente mayor en el grupo de 5 a 11 años de edad. Se observó que entre el 47,6 y el 62 por ciento de los niños con hábitos deformantes presentaban maloclusiones. Se recomendó seguir incrementando la atención primaria de Ortodoncia como método, para contribuir a satisfacer las necesidades crecientes de tratamiento de ortodoncia(AU)


Subject(s)
Humans , Child , Diagnosis, Oral , Malocclusion/epidemiology , Dental Occlusion , Dental Care , Primary Health Care
17.
Rev. cuba. ortod ; 12(1): 96-101, ene.-jun. 1997. tab
Article in Spanish | LILACS | ID: lil-205338

ABSTRACT

Se realizó un estudio epidemiológico descriptivo transversal, en una muestra representativa de 896 niños de 0 a 14 años de edad del área de salud Florencia, en la Provincia Ciego de Avila, durante el curso escolar 1995-1995, para conocer el diagnóstico ortodóntico de esta población. Se encontró una prevalencia de maloclusión entre 25,0 y 30,8 por ciento, la cual fue significativamente mayor en el grupo de 5 a 11 años de edad. Se observó que entre el 47,6 y el 62 por ciento de los niños con hábitos deformantes presentaban maloclusiones. Se recomendó seguir incrementando la atención primaria de Ortodoncia como método, para contribuir a satisfacer las necesidades crecientes de tratamiento de ortodoncia


Subject(s)
Humans , Child , Dental Care , Dental Occlusion , Diagnosis, Oral , Malocclusion/epidemiology , Primary Health Care
18.
Rev cuba ortod ; 11(2): 75-81, jul.- dic. 1996. ilus
Article in Spanish | CUMED | ID: cum-8263

ABSTRACT

Se analizan 3 pacientes con alteraciones dentoesqueletales que acudieron a los servicios multidisciplinarios y que en su infancia recibieron tratamiento ortodóntico convencional con aparatología fija. Se muestra cómo en ocasiones la corrección dentaria no satisface la espectativa del paciente con relación de la alteraciones esqueletales que influyen en la forma de la cara (AU)


Subject(s)
INFORME DE CASO , Humans , Female , Adult , Orthodontics, Corrective/adverse effects , Mouth Abnormalities/therapy , Jaw Abnormalities/therapy , Evaluation of Results of Therapeutic Interventions
19.
Rev. cuba. ortod ; 11(2): 75-81, jul.-dic. 1996. ilus
Article in Spanish | LILACS | ID: lil-182978

ABSTRACT

Se analizan 3 pacientes con alteraciones dentoesqueletales que acudieron a los servicios multidisciplinarios y que en su infancia recibieron tratamiento ortodontico convencional con aparatologia fija. Se muestra como en ocasiones la correccion dentaria no satisface la espectativa del paciente con relacion de la alteraciones esqueletales que influyen en la forma de la cara


Subject(s)
Humans , Female , Adult , Mouth Abnormalities/therapy , Evaluation of Results of Therapeutic Interventions , Jaw Abnormalities/therapy , Orthodontics, Corrective/adverse effects
20.
Rev cuba ortod ; 11(1): 22-5, ene.-jun. 1996. tab
Article in Spanish | CUMED | ID: cum-7992

ABSTRACT

Se realiza un estudio representativo de 325 niños menores de 15 años de edad, del área de salud "Venezuela", de la provincia Ciego de Avila, durante el curso 1993-1994, para conocer el diagnóstico de salud ortodóntico de esta población. Se encontró una prevalencia de maloclusión de 43,08 por ciento. Los niños más afectados fueron los de las escuelas primarias, que tenían edades entre 5 y 11 años. La presencia de los hábitos bucales deformantes se encontró muy ligada a la aparición de maloclusiones. Recomendamos al incremento de la aplicación de los programas de atención primaria de ortodoncia (AU)


Subject(s)
Humans , Infant , Child, Preschool , Child , Adolescent , Oral Health , Diagnosis, Oral , Dental Occlusion , Malocclusion , Tooth Eruption , Orthodontics, Corrective
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