Understanding the process of envelope glycoprotein incorporation into virions in simian and feline immunodeficiency viruses

The lentiviral envelope glycoproteins (Env) mediate virus entry by interacting with specific receptors present at the cell surface, thereby determining viral tropism and pathogenesis. Therefore, Env incorporation into the virions formed by assembly of the viral Gag polyprotein at the plasma membrane of the infected cells is a key step in the replication cycle of lentiviruses. Besides being useful models of human immunodeficiency virus (HIV) infections in humans and valuable tools for developing AIDS therapies and vaccines, simian and feline immunodeficiency viruses (SIV and FIV, respectively) are relevant animal retroviruses; the study of which provides important information on how lentiviral replication strategies have evolved. In this review, we discuss the molecular mechanisms underlying the incorporation of the SIV and FIV Env glycoproteins into viral particles.Fil: Affranchino, Jose Luis. Universidad de Belgrano. Facultad de Ciencias Exactas y Naturales. Laboratorio de Virología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gonzalez, Silvia Adriana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Belgrano. Facultad de Ciencias Exactas y Naturales. Laboratorio de Virología; Argentin

On the disintegration of cosmic ray nuclei by solar photons

We discuss in detail the possibility of observing pairs of simultaneous parallel air showers produced by the fragments of cosmic ray nuclei which disintegrated in collisions with solar photons. We consider scenarios with different cosmic ray compositions, exploring the predicted rates for existing and planned detectors and looking for methods to extract information on the initial composition from the characteristics of the signal. In particular, we find that fluorescence detectors, such as HiRes or the Telescope Array, due to their low threshold ($\sim 10^{17}$ eV) and large area ($\sim 10^4 km^2$) may observe several events per year if cosmic rays at those energies are indeed heavy nuclei. The possibility of exploiting the angular orientation of the plane containing the two showers to further constrain the cosmic ray composition is also discussed.Comment: 15 page

The effect of social programs and exposure to professionals on the educational aspirations of the poor

Investment in human capital is an important tool for reducing poverty. However, the poor may lack the capacity to aspire, which often results in underinvestment in their children’s education. This paper studies the effect of a social program on the educational aspirations of the poor, and explores the role of exposure to educated professionals as a possible channel for increasing aspirations. First, using differences-in-differences, we show that beneficiary parents of the Mexican antipoverty program PROGRESA have higher educational aspirations for their children of a third of a school year than do non-beneficiary parents. This effect corresponds to a 15% increase in the proportion of parents who aspire for their children to finish college. Then, we exploit the design of the program whose requirements cause its target population to have different levels of mandated exposure to doctors and nurses. Our triple difference estimate shows that, educational aspirations for children from high-exposure households (relative to low- exposure households) in treatment villages (relative to control villages) were a third of a school year higher six months after the start of the program (relative to before its introduction). These results suggest that the change in aspirations is driven by exposure to highly educated professionals.social programs, educational aspirations, poverty, educational aspirations

The euro area Bank Lending Survey matters: empirical evidence for credit and output growth

This study examines empirically the information content of the euro area Bank Lending Survey for aggregate credit and output growth. The responses of the lending survey, especially those related to loans to enterprises, are a significant leading indicator for euro area bank credit and real GDP growth. Notwithstanding the short history of the survey, the findings are robust across various specifications, including “horse races” with other well-known leading financial indicators. Our results are supportive of the existence of a bank lending, balance sheet, and risk-taking channel of monetary policy. They also suggest that price as well as non-price conditions and terms of credit standards do matter for credit and business cycles. Finally, we discuss the implications for the 2007/2009 financial and economic crisis. JEL Classification: C23, E32, E51, E52, G21, G28bank lending survey, business cycle, credit cycle, euro area, Monetary policy transmission

Teachers who leave a mark. Personal biography and professional identity in memorable teachers

Fernández Cruz (1994), states that identity relates to the building of one-self in the interactionwith others. Professional identification in teaching is a slow process. Some people start undergoingthis process in childhood, some others with their professional practice. In this research advancewe analyze the life story of a university teacher from the Faculty of Architecture, Mar del PlataNational University (UNMdP) previously identified as a memorable professor by his students. Adeep cycle called biographical stimulated self theme (Kelchterman, 1993) in which the professor isled to reconstruct his biography and its sense, stems from the understanding and reconstruction ofhis professional life. This allows us to organize, focus, interpret, understand and validate what heis narrating. In this way tensions understood as categories emerge, associated to the meaning theprofessor himself gives to his own personal, professional experience and development

Glyphosate and AMPA concentrations in wind-blown material under field conditions

Agricultural intensification in fragile arid and semiarid environments has led to an increase in soil degradation, mainly through wind erosion. Argentina is an agricultural and cattle-farming country, which has increased its productivity in the last few decades, widening the boundaries of farm land and the use of herbicides to control weeds. Glyphosate, which accounts for 65% of the Argentinian pesticides market, is strongly retained in soil. The World Health Organization concluded that there was evidence to classify glyphosate as ‘probably carcinogenic to humans.’ In this context, the objective of this study was to determine the presence and concentration of glyphosate and aminomethylphosphonic acid (AMPA) in wind-blown material in 3 areas in Argentine semiarid regions (Chaco, La Pampa, and San Luis). In 1-ha2 plots, left uncovered and levelled, the wind-blown material was collected at heights of 13.5, 50, and 150 cm during 18 erosion events. The wind-blown material carried by the wind at a height of 150 cm had concentrations of 247 and 218 μg kg−1 of glyphosate and AMPA, respectively. This material was enriched 60 times in glyphosate and 3 times in AMPA as compared with the original soil. This shows that the eroded material can, potentially, have a negative impact on the ecosystem and also on human health, depending on the proportion of this material released into the atmosphere in suspension as particulate matter. This study is, to our knowledge, the first to report concentrations of glyphosate and AMPA in wind-blown material under field conditions.Fil: Aparicio, Virginia Carolina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Aimar, Silvia Beatriz. Universidad Nacional de La Pampa. Facultad de Agronomía; ArgentinaFil: de Gerónimo, Eduardo. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mendez, Mariano Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa; ArgentinaFil: Costa, Jose Luis. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce; Argentin

Un reto para enseñar las cadenas de Markov en undécimo grado

En el estudio de las cadenas de Markov, la probabilidad condicional es un objeto matemático que se desarrolla bajo el argumento práctico del análisis de fenómenos cotidianos sujeto a una relación de dependencia entre observaciones. Así, los objetivos de este conjunto de actividades son: ilustrar e interpretar la relación de dependencia anteriormente referida así como la relación entre conceptos de probabilidad y matemática que subyacen a su aplicación; ofrecer al estudiante de 11° grado otras formas de representar los sucesos del medio desde el enfoque del análisis de datos y probabilidad; y finalmente, resaltar y establecer las conexiones existentes entre las representaciones propuestas durante las sesiones del taller