Atmospheric mass loss by stellar wind from planets around main sequence M stars

We present an analytic model for the interaction between planetary atmospheres and stellar winds from main sequence M stars, with the purpose of obtaining a quick test-model that estimates the timescale for total atmospheric mass loss due to this interaction. Planets in the habitable zone of M dwarfs may be tidally locked and may have weak magnetic fields, because of this we consider the extreme case of planets with no magnetic field. The model gives the planetary atmosphere mass loss rate as a function of the stellar wind and planetary properties (mass, atmospheric pressure and orbital distance) and an entrainment efficiency coefficient $\alpha$. We use a mixing layer model to explore two different cases: a time-independent stellar mass loss and a stellar mass loss rate that decreases with time. For both cases we consider planetary masses within the range of $1\to10$ M$_{\oplus}$ and atmospheric pressures with values of 1, 5 and 10 atm. For the time dependent case, planets without magnetic field in the habitable zone of M dwarfs with initial stellar mass losses of $\leq \dot{M}_{w} < 10^{-11}$ M$_{\odot}$ yr$^{-1}$, may retain their atmospheres for at least 1 Gyr. This case may be applied to early spectral type M dwarfs (earlier than M5). Studies have shown that late type M dwarfs (later than M5) may be active for long periods of time ($\geq 4$Gyr), and because of that our model with constant stellar mass loss rate may be more accurate. For these stars most planets may have lost their atmospheres in 1 Gyr or less because most of the late type M dwarfs are expected to be active. We emphasize that our model only considers planets without magnetic fields. Clearly we must expect a higher resistance to atmospheric erosion if we include the presence of a magnetic field.Comment: Icarus, submitted. 18 pages, 6 figure

Integrated control of chagas disease for its elimination as public health problem: A review

Chagas disease or American trypanosomiasis is, together with geohelminths, the neglected disease that causes more loss of years of healthy life due to disability in Latin America. Chagas disease, as determined by the factors and determinants, shows that different contexts require different actions, preventing new cases or reducing the burden of disease. Control strategies must combine two general courses of action including prevention of transmission to prevent the occurrence of new cases (these measures are cost effective), as well as opportune diagnosis and treatment of infected individuals in order to prevent the clinical evolution of the disease and to allow them to recuperate their health. All actions should be implemented as fully as possible and with an integrated way, to maximise the impact. Chagas disease cannot be eradicated due because of the demonstrated existence of infected wild triatomines in permanent contact with domestic cycles and it contributes to the occurrence of at least few new cases. However, it is possible to interrupt the transmission of Trypanosoma cruzi in a large territory and to eliminate Chagas disease as a public health problem with a dramatic reduction of burden of the disease.Fil: Sosa-Estani, Sergio Alejandro. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud. Instituto Nacional de Parasitología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Segura, Elsa Leonor. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud. Instituto Nacional de Parasitología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

O pastor, o doutor e o Big Data

The rise of the Internet as a space for global interaction makes the political subjectivation of automated surveillance especially important for understanding the mechanisms of social control in our current culture. This essay approaches mass electronic surveillance from the perspective of the processes of production of subjectivities among users of the Net. It will briefly outline a history of the production of subjects as related to the necessity of expressing a certain truth about themselves, of confessing and conforming to a normality regulated by the strategic frameworks of power. At the same time, it will attempt to associate the logic of that history with the rise of Big Data as a device for the tracking, discrimination and management of personal data. Finally, the paper will provide some reflections on the significance of resistance to the loss of privacy in digital culture.La consolidación de Internet como espacio de relación global implica que la subjetivación política de la vigilancia automatizada adquiera especial relevancia a la hora de comprender los mecanismos de control social en nuestra cultura. Este ensayo pretende ser una aproximación a la cuestión de la vigilancia masiva desde la perspectiva de los procesos de configuración de subjetividades de los usuarios de la red. Es por ello que se procurará trazar sucintamente un recorrido histórico de producción de sujetos en torno a la necesidad de expresar cierto tipo de verdad sobre sí mismos, de confesar y de conformar con una normalidad reglada por los marcos estratégicos del poder. Al mismo tiempo, se tratará de poner en relación la lógica de ese recorrido con el advenimiento del Big Data como dispositivo de rastreo, discriminación y tratamiento de información personal; para, finalmente, reflexionar sobre el sentido de la resistencia a la pérdida de privacidad en la cultura digital.A consolidação da Internet como espaço de relação global resulta na subjetivação políticade vigilância automatizada que vai adquirindo especial relevância na hora de compreender os mecanismos de controle social em nossa cultura. Este ensaio pretende aproximar-se à questão da vigilância massiva desde a perspectiva dos processos configuradores de subjetividades que incidem sobre os usuários da rede. Para isso será delimitado um período histórico de produção de sujeitos ao redor da necessidade de expressar um certo tipo de verdade sobre si mesmo, de confessar e de adequar-se a uma normalidade regrada por marcos estratégicos depoder. Simultaneamente, esta lógica será relacionada ao surgimento do Big Data como dispositivo de rastreio, registro e tratamento de informação pessoal para, finalmente, refletir sobre o sentido da resistência à perda de privacidade na cultura digital

El impacto de la motivación en el desempeño de sus empleados. Estudio de caso: Google

Treball Final de Grau en Relacions Laborals i Recursos Humans. Codi: RL0947. Curs acadèmic: 2016/2017Los recursos humanos han sufrido un importante cambio y evolución a lo largo de los años, modificando incluso el significado y valor de los mismos con respecto a sus inicios. En un contexto donde la sociedad es tan dependiente de las organizaciones y el mundo empresarial, analizamos el valor del factor humano en toda esta ecuación, y, por consiguiente, las diferentes visiones en cuanto a la gestión del talento y tratamiento de las personas, tomando como referencia a una de las empresas más conocidas a nivel internacional, Google, considerada pionera en muchas de sus técnicas en cuanto a motivación y tratamiento de las personas. El presente trabajo se centrará en valorar el impacto de la motivación y una política moderna del tratamiento de personas y la respuesta de los mismos, del mismo modo, analizaremos los efectos positivos y negativos, resultantes de apostar por una política abierta en la gestión de personas.Human resources have undergone a major change and an evolution over the years, also modifying the meaning and value of the same with respect to its beginnings. In a context in which society is so dependent on organizations and the business world, I will analyze the value of the human factor in the whole equation, and the different visions of talent and the treatment of people by the management companies. As a reference to one of the most internationally known companies, Google, considered a pioneer in many of its techniques in terms of motivation and treatment of people. The current work is focused on assessing the impact of motivation and a modern policy on the treatment of people and their response. Likewise, we will analyze the positive and negative effects, resulting from betting on an open policy in the management of people

Development of an optrode for characterization of tissue optical properties at the neural tissue-electrode interface

Thesis (M.Sc.Eng.)The use of implantable neural probes has become common, both for stimulation and recording, and their applications range from chronic pain treatment to implementation of brain machine interfaces (BMI). Studies have shown that signal quality of implanted electrodes decays over time mainly due to the immune response. Characterization of the tissue-electrode interface is critical for better understanding of the physiological dynamics and potential performance improvement of the electrode itself and its task. This work describes the fabrication of an implantable electrode with optical measurement capabilities for providing means to characterize the tissue-electrode interface using optical spectroscopy. The electrode has a set of waveguides embedded in its shanks, which are used to inject white light into tissue and then collect the light reflected from the tissue surrounding the shanks. The collected light was analyzed with a spectrometer and the spectra processed to detect changes in optical properties, information that allows to track physiological changes. It is believed that the immune response can be correlated to changes in scattering as more cells are recruited to the injury site. The increased cell density in local injury/implantation sites increases the amount of scattering due to the increased number of cell nuclei and membranes that light encounters in its path. Investigation of scattering and absorption coefficients in such interface and their change over time can provide useful data for modeling and determining physiological parameters like blood oxygenation while the actual shape of the acquired spectra might highlight particular phenomena that can be indicative of scaring process or hemorrhaging. Validation of this system was done using optical phantoms based on polystyrene spheres and solutions with various concentrations of fat emulsion, which yielded scattering coefficients similar to those of brain tissue. Results suggest that the developed optrodes are able to detect differences between samples with different scattering coefficients. Improvements of fabrication process are discussed based on experimental results and future work includes attempting to perform fluorescence measurements of voltage reporters for optogenetic applications. The ultimate goal of this project was to create a novel device that is capable of satisfying the unmet need of tissue characterization at the implanted electrode interface as well as a tool for the optogenetics field suitable for greater depths than those a microscope can achieve

Electrocardiographic Abnormalities and Treatment with Benznidazole among Children with Chronic Infection by Trypanosoma cruzi: A Retrospective Cohort Study

Background: Chronic infection by Trypanosoma cruzi could cause heart conduction disturbances. We sought to analyze electrocardiographic abnormalities among children with chronic T. cruzi infection with and without trypanocidal treatment with benznidazole. Methodology/Principal Findings: We studied 111 children 6–16 years of age with asymptomatic chronic T. cruzi infection who were recruited in 1991–1992 in Salta, Argentina. Most children were randomly assigned to benznidazole 5 mg/Kg/day (n = 47) or matching placebo (n = 48) for 60 days. Remaining children (n = 16) received treatment with benznidazole 5 mg/Kg/day open-label. Electrocardiograms were obtained at baseline and in 1995–1996, 1998, 2000 and 2005, and were analyzed using the Buenos Aires method. Among the 94 children with an electrocardiogram at baseline, 8 (8.5%) had electrocardiographic abnormalities, including 4 (4.7%) children with right bundle branch block. Proportion of abnormal electrocardiograms in the full population (n = 111) remained constant over time (media follow-up 8.6 years). Multivariable adjusted prevalence ratios (95% confidence interval [95%CI]) for electrocardiographic abnormalities in 1995–1996, 1998, 2000 and 2005 comparing children treated with benznidazole versus those not treated were 2.76 (0.66, 11.60), 2.33 (0.44, 12.31), 3.06 (0.48, 19.56), and 1.94 (0.33, 11.25), respectively. Among the 86 children with a normal electrocardiogram at baseline, 16 (18.6%) developed electrocardiographic abnormalities during follow-up. The multivariable adjusted hazard ratio for incident electrocardiographic abnormalities comparing children treated with benznidazole versus those not treated was 0.68 (95%CI: 0.25, 1.88). Conclusions/Significance: Electrocardiographic abnormalities are frequent among children with chronic T. cruzi infection. Treatment with benznidazole for 60 days may not be associated with less electrocardiographic abnormalities.Fil: Colantonio, Lisandro Damián. University of Alabama at Birmingahm; Estados Unidos. Universidad de Buenos Aires. Facultad de Medicina; ArgentinaFil: Prado, Nilda. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud “Dr. C. G. Malbrán”. Instituto Nacional de Parasitología "Dr. Mario Fatala Chaben”; ArgentinaFil: Segura, Elsa Leonor. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud “Dr. C. G. Malbrán”. Instituto Nacional de Parasitología "Dr. Mario Fatala Chaben”; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Sosa-Estani, Sergio Alejandro. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud “Dr. C. G. Malbrán”. Instituto Nacional de Parasitología "Dr. Mario Fatala Chaben”; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Southernmost record of Yellow-headed Vulture, <i>Cathartes burrovianus</i> Cassin, 1845 (Cathartiformes, Cathartidae), in Buenos Aires Province, Argentina

We report the southernmost record of Yellow-headed Vulture, Cathartes burrovianus, in Punta Piedras, north-eastern Buenos Aires province, Argentina. This record implies the presence of this species in a new habitat: the Pampas ecoregion. Considering this and other records in Argentina and Uruguay, the species distribution could be extending south from its known range.Facultad de Ciencias Naturales y Muse

Southernmost record of Yellow-headed Vulture, <i>Cathartes burrovianus</i> Cassin, 1845 (Cathartiformes, Cathartidae), in Buenos Aires Province, Argentina

We report the southernmost record of Yellow-headed Vulture, Cathartes burrovianus, in Punta Piedras, north-eastern Buenos Aires province, Argentina. This record implies the presence of this species in a new habitat: the Pampas ecoregion. Considering this and other records in Argentina and Uruguay, the species distribution could be extending south from its known range.Facultad de Ciencias Naturales y Muse

Southernmost record of Yellow-headed Vulture, <i>Cathartes burrovianus</i> Cassin, 1845 (Cathartiformes, Cathartidae), in Buenos Aires Province, Argentina

We report the southernmost record of Yellow-headed Vulture, Cathartes burrovianus, in Punta Piedras, north-eastern Buenos Aires province, Argentina. This record implies the presence of this species in a new habitat: the Pampas ecoregion. Considering this and other records in Argentina and Uruguay, the species distribution could be extending south from its known range.Facultad de Ciencias Naturales y Muse

Prototipo de aplicativo para especificar requerimientos de software

Trabajo de InvestigaciónLa especificación de requerimientos para un desarrollo eficaz del producto necesario en una empresa o entidad es de gran importancia, tanto para los intereses económicos como para resolver los problemas que el proyecto plantea. Este trabajo de grado está pensado y desarrollado para minimizar los errores en la especificación de requerimientos de negocio a través de un aplicativo, diseñado para que el Core del negocio es decir, la parte donde el cliente recita las expectativas del proyecto, sea lo más objetiva posible, concediendo al grupo de analistas una mejor idea del producto final que se quiere implementar.INTRODUCCIÓN 1. PLANTEAMIENTO DEL PROBLEMA 2. OBJETIVOS DEL PROYECTO 3. MARCO REFERENCIAL 4. METODOLOGÍA PROPUESTA 5. LECTURA DE PAPERS 6. DESARROLLO DEL PROYECTO 7. CONCLUSIONES BIBLIOGRAFÍA ANEXOSPregradoIngeniero de Sistema