3,690 research outputs found
Einstein's unpublished opening lecture for his course on relativity theory in Argentina, 1925
In 1922 the University of Buenos Aires (UBA) Council approved a motion to
send an invitation to Albert Einstein to visit Argentina and give a course of
lectures on his theory of relativity. The motion was proposed by Jorge Duclout
(1856-1927), who had been educated at the Eidgenossische Technische Hochschule,
Zurich (ETH). This proposal was the culmination of a series of initiatives of
various Argentine intellectuals interested in the theory of relativity. In a
very short time Dr. Mauricio Nirenstein (1877-1935), then the university's
administrative secretary, fulfilled all the requirements for the university's
invitation to be endorsed and delivered to the sage in Berlin. The visit took
place three years later, in March-April 1925.
The Argentine press received Einstein with great interest and respect; his
early exchanges covered a wide range of topics, including international
politics and Jewish matters. Naturally, the journalists were more eager to hear
from the eminent pacifist than from the incomprehensible physicist. However,
after his initial openness with the press, the situation changed and Einstein
restricted his public discourse to topics on theoretical physics, avoiding some
controversial political, religious, or philosophical matters that he had freely
touched upon in earlier interviews.. [abridged].Comment: Published version available at
http://www.universoeinstein.com.ar/einsteinargentina.ht
Diabetic retinopathy: could the alpha-1 antitrypsin be a therapeutic option?
Diabetic retinopathy is one of the most important causes of blindness. The underlying mechanisms of this disease include inflammatory changes and remodeling processes of the extracellular-matrix (ECM) leading to pericyte and vascular endothelial cell damage that affects the retinal circulation. In turn, this causes hypoxia leading to release of vascular endothelial growth factor (VEGF) to induce the angiogenesis process. Alpha-1 antitrypsin (AAT) is the most important circulating inhibitor of serine proteases (SERPIN). Its targets include elastase, plasmin, thrombin, trypsin, chymotrypsin, proteinase 3 (PR-3) and plasminogen activator (PAI). AAT modulates the effect of protease-activated receptors (PARs) during inflammatory responses. Plasma levels of AAT can increase 4-fold during acute inflammation then is so-called acute phase protein (APPs). Individuals with low serum levels of AAT could develop disease in lung, liver and pancreas. AAT is involved in extracellular matrix remodeling and inflammation, particularly migration and chemotaxis of neutrophils. It can also suppress nitric oxide (NO) by nitric oxide sintase (NOS) inhibition. AAT binds their targets in an irreversible way resulting in product degradation. The aim of this review is to focus on the points of contact between multiple factors involved in diabetic retinopathy and AAT resembling pleiotropic effects that might be beneficial.Fil: Ortiz, Gustavo Alfredo. Universidad Austral. Facultad de Ciencias Biomédicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Salica, Juan Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Austral. Facultad de Ciencias Biomédicas; ArgentinaFil: Chuluyan, Hector Eduardo. Universidad de Buenos Aires. Facultad de Medicina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gallo, Juan Eduardo Maria. Universidad Austral. Facultad de Ciencias Biomédicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
02: Perceptions of “community” about Hispanic/Latinos living in Cache Valley, Utah
We are going to explore briefly the dynamic and complex communal stories of many Hispanic/Latino members living in Cache Valley. As we know, each community is unique and each one has different forms, sizes, capitals, and infinite human dimensions. It has been accepted that the concept of community should always include at least three important elements: a) A place or geographic territory, b) The people living on that place or territory, and c) The personal interactions and developed relationships that helped to establish common goals, principles, and values and shared beliefs. We will review some recorded stories on the context of the three elements of place, people, and interactions for interpretation and analysis related to the community life Hispanic/Latino residents of Cache Valley, Utah.https://digitalcommons.usu.edu/latino_voices/1000/thumbnail.jp
A vulnerability approach to the definition of the middle class
Measurement of the middle class has recently come to the center of policy debate in middle-income countries as they search for the potential engines of growth and good governance. This debate assumes, first, that there is a meaningful definition of class, and second, that thresholds that define relatively homogeneous groups in terms of pre-determined sociological characteristics can be found empirically. This paper aims at proposing a view of the middle class based on vulnerability to poverty. Following this approach the paper exploits panel data to determine the amount of comparable income -- associated with a low probability of falling into poverty -- which could define the lower bound of the middle class. The paper looks at absolute thresholds, challenging the view that people above the poverty line are actually part of the middle class. The estimated lower threshold is used in cross-section surveys to quantify the size and the evolution of middle classes in Chile, Mexico, and Peru over the past two decades. The first relevant feature relates to the fact that the proposed thresholds lie around the 60th percentile of the distribution. The evidence also shows that the middle class has increased significantly in all three countries, suggesting that a higher number of households face lower probabilities of falling into poverty than they did in the 1990s. There is an important group of people, however, which cannot be defined as middle class from this perspective, but are not eligible for poverty programs according to traditional definitions of poverty.Rural Poverty Reduction,Inequality,Regional Economic Development,Urban Partnerships&Poverty,Services&Transfers to Poor
Mecanismos, lenguajes, y geometría: Lanz y la composición de las máquinas
Este trabajo es parte de un estudio en el que se trata de construir la filiación de algunas ideas básicas de las ciencias exactas que, habiendo llegado en diferentes épocas, finalmente se arraigaron en el mundo científico de habla hispana. En este trabajo analizo ideas cuya motivación inicial se relaciona con el desarrollo del concepto de máquina, y que luego se extendió en direcciones más abstractas
Episiotomia e laceração perineal no parto vertical.
Trabalho de Conclusão de Curso - Universidade Federal de Santa Catarina, Centro de Ciências da Saúde, Departamento de Tocoginecologia, Curso de Medicina, Florianópolis, 199
The thermal degradation of polyvinyl alcohol
The thermal degradation of polyvinyl alcohol has been investigated using mass spectrometry, differential thermal analysis, and infrared spectroscopy unlike previous investigators, formaldehyde and acrolein were not observed volatiles. In addition, acetic acid was observed, a product not reported previously
The Influence of Family Structure and the Role of Siblings on Early Language Development of Latino Preschool Children
The purpose of this research is to examine the relationship between family structure including family size, number of parents at home, and presence of an older sibling at home, and the language development of young Latino children. I used data from the Head Start--Family and Child Experiences Survey (FACES) year 2000, which included information on 746 Latino preschool children and their families in different Head Start programs nationwide. A subgroup of 369 children were identified as English-language learners (ELL) because they were determined to be primarily Spanish speaking. Some of the findings indicate that more than two thirds of children (69%) who do not have two parents at home are primarily English speakers and more than two thirds of children (68%) who have two parents at home are primarily Spanish speakers. Independent sample t tests indicate there are statistically significant differences between Latino primarily Spanish speakers and Latino primarily English speakers on vocabulary and early literacy outcomes. Family background variables such as English language proficiency of parents and parent education are important factors that affect early language and literacy development of their children. In addition, family structure variables have some effects on these outcomes. The variables family poverty and family size, specifically having an older sibling, had negative impacts only on the primarily English-speaking group. The most influential social factors for the Latino primarily English-speaking preschool children\u27s language and literacy outcomes are different than the most influential social factors for the same outcomes of their primarily Spanish-speaking preschooler counterparts who in general experience less favorable outcomes overall
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