342 research outputs found
Efeito do Potato virus X no conteúdo de fenóis totais e alcalóides em folhas de Datura stramonium
The present paper reports results of the effect of Potato virus X (PVX) on the contents of total phenols and alkaloids in leaves of Datura stramonium. A significant decrease in the contents of phenols and alkaloids was observed in leaves inoculated with PVX (X-I). However, there was an increase in the percentage of phenols in leaves rubbed with phosphate buffer (C1-I) and in leaves from the nodes immediately above, possibly induced by mechanical injury. Gas chromatography/mass spectroscopy revealed amounts of scopolamine in samples submitted to all treatments, except X-I, in which the amount of this alkaloid was low. High amounts of an unidentified compound (molecular ion m/z 302 and a prominent peak at m/z 129) were noted in extracts from leaves X-I, C1-I and leaves from the nodes immediately above the leaves inoculated with PVX. It is suggested that the synthesis and accumulation of the unidentified compound is a result of stress from mechanical injury and virus inoculation.O presente trabalho relata resultados sobre a ação do Potato virus X (PVX) no conteúdo de fenóis totais e alcalóides em folhas de Datura stramonium. Uma diminuição significativa no conteúdo dessas substâncias foi observada nas folhas inoculadas com o PVX (X-I). Entretanto, houve um aumento na porcentagem de fenóis nas folhas friccionadas com tampão fosfato (C1-I) e nas acima das friccionadas, possivelmente induzido por injúria mecânica. Cromatografia gasosa/espectroscopia de massas revelou quantidades de escopolamina nas amostras submetidas a todos os tratamentos, exceto em X-I, no qual a quantidade deste alcalóide foi baixa. Altas quantidades de uma substância não identificada (Ãon molecular m/z 302 e um proeminente pico a m/z 129) foram notadas em extratos a partir de folhas dos tratamentos X-I, C1-I e nas acima das inoculadas com o PVX. Sugere-se que a sÃntese e acúmulo da substância não identificada é um resultado do estresse causado pela injúria mecânica e pelo vÃrus
Sensitivity to Cosmic Rays of Cold Electron Bolometers for Space Applications
An important phenomenon limiting the sensitivity of bolometric detectors for
future space missions is the interaction with cosmic rays. We tested the
sensitivity of Cold Electron Bolometers (CEBs) to ionizing radiation using
gamma-rays from a radioactive source and X-rays from a X-ray tube. We describe
the test setup and the results. As expected, due to the effective thermal
insulation of the sensing element and its negligible volume, we find that CEBs
are largely immune to this problem.Comment: LTD15; 6 pages, 6 figure
Cold-electron bolometers for future mm and sub-mm sky surveys
Future sky surveys in the mm/sub-mm range, like the forthcoming balloon-borne
missions LSPE, OLIMPO, SPIDER etc., will need detectors insensitive to cosmic
rays (CRs) and with a NEP of the order of W/sqrt(Hz).
The Cold-Electron Bolometers (CEBs) technology is promising, having the
required properties, since the absorber volume is extremely small and the
electron system of the absorber is thermally insulated from the phonon system.
We have developed an experimental setup to test the optical performance and the
CRs insensitivity of CEBs, with the target of integrating them in the OLIMPO
and LSPE focal planes.Comment: 6 figure
De prescindibles a indispensables: trabajadores y trabajadoras agrÃcolas del Valle de Uco en contexto de pandemia
En las últimas décadas, el Valle de Uco se ha convertido en un lugar fértil para el gran capital, con una importante expansión de las medianas y grandes empresas en el sector agrÃcola. Esto se destaca en la vitivinicultura, aunque también sucede en la fruticultura y la horticultura. La zona en su conjunto es presentada como un caso exitoso de modernización del sector agropecuario donde se destacan los cambios tecnológicos y la mecanización de las actividades, asà como la incorporación de nuevas variedades de vid y frutales, y de cultivares hortÃcolas. Además, se observa una importante expansión de la frontera productiva gracias a las nuevas tecnologÃas de perforación y riego, que posibilitan la producción en tierras que antes eran consideradas improductivas o poco fértiles. Generalmente, cuando se describe la agricultura de la zona, los/as trabajadores/as del agro están ausentes o aparecen como un costo prescindible y sencillamente reemplazable por una máquina. No obstante, la producción de la zona requiere de gran cantidad de trabajadores/as para llevar adelante un variado calendario de actividades agrÃcolas en las más de 50.000 hectáreas cultivadas. Incluso, en la época de cosecha, el requerimiento de mano de obra aumenta de forma significativa, cuestión que se resuelve con la movilidad de trabajadores estacionales -en su mayorÃa procedentes del noroeste de Argentina: Jujuy, Salta, Tucumán y Santiago del Estero, como asà también de Bolivia-. Durante el 2020 y lo que va del 2021, el contexto de emergencia sanitaria por el Covid-19 plantea de una situación inusual, los empresarios y productores reconocieron la importancia del trabajo agrÃcola y le reclamaron al gobierno la urgencia de tomar las medidas necesarias para contar con trabajadores/as. Para estos sectores el problema a resolver era la disposición de mano de obra para continuar con la actividad. Es por ello que se establecieron protocolos, mesas de trabajo y programas en pos de resolver esta problemática. Aun asÃ, las condiciones históricas de precariedad laboral y de vulnerabilidad de los trabajadores/as agrÃcolas, se tornaron crÃticas y, en muchos casos, resultó imposible el cumplimiento de estas medidas. En esta ponencia, se aborda la disyuntiva entre trabajo esencial y trabajo precario en la agricultura. Se indaga sobre los protocolos que entraron en vigencia y cómo fueron puestos en marcha efectivamente en los territorios, en este caso, el Valle de Uco. Damos cuenta de la distancia que existe entre las medidas recomendadas en estos últimos meses y la situación concreta del trabajo en la agricultura. Más allá de la formalidad o informalidad del vÃnculo laboral (estar o no registrados) nos referimos a las condiciones históricas de precariedad, vulnerabilidad y desigualdad en las que se encuentran insertos los/as trabajadores/as agrÃcolas. La metodologÃa de este trabajo combina técnicas conversacionales, con rastreo documental y uso de fuentes secundarias. Se utilizan entrevistas semi-estructuradas realizadas a diferentes actores (trabajadores/as; productores; intermediarios y referentes institucionales), además se realizó un seguimiento de la problemática en medios de comunicación. Finalmente, para analizar los datos de contexto y estructurales se recurrió a fuentes de datos de secundarios (censos de población, censo agropecuario, entre otros).Fil: Salatino, Maria Noelia. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Mendoza; Argentina. Instituto Nacional de TecnologÃa Agropecuaria. Centro Regional Mendoza-San Juan. Estación Experimental Agropecuaria La Consulta; ArgentinaPREASET X Pre Congreso Regional de Especialistas en Estudios del Trabajo: Transformaciones en las condiciones de trabajo en tiempos de pandemiaMendozaArgentinaUniversidad Nacional de Cuyo. Instituto de Trabajo y Producció
Women, land and territory
In this article we present a review of the book "We are land, seed, rebellion, women, land and territory in Latin America" by Claudia Korol. In this work, the author analyzes the inequalities faced by rural women in Latin America to access land tenure and use. His presentation presents an important synthesis of different views on territory, land ownership, patriarchy and colonialism, whose common objective is to make visible the place of women in rural and agrarian areas. Claudia Korol interpellates the Eurocentric and Western perspectives that some gender studies go through, at the same time that she dialogues with community feminisms, indigenous feminisms, black feminisms and eco-feminism. Discussing women's access to the land, is for the author, not only a debate in terms of economy, but in terms of politics and culture, of imagining and fighting for a life alternative, more just not only with women but also with nature
Horticultura en el Valle de Uco, una aproximación a los sujetos sociales hortÃcolas
En este artÃculo presentamos una serie de reflexiones en torno a la horticultura delValle de Uco, partimos de considerar que el entramado social de esta zona esdiferente al de otros cinturones hortÃcolas, principalmente por su orientación a laproducción de hortalizas pesadas. En primer lugar, damos cuenta de algunos de losrasgos de la horticultura argentina, luego describimos de forma general lascaracterÃsticas productivas y territoriales de la horticultura en la zona; y, finalmente,presentamos un acercamiento a los sujetos sociales de la horticultura de este valle. Eltexto representa un esfuerzo de sÃntesis de lecturas y aproximaciones realizadas en elmarco de la tesis doctoral43, por lo tanto, no pretende ser exhaustivo ni definitivo, sinoque busca aportar a esa reflexión.Fil: Salatino, Maria Noelia. Instituto Nacional de TecnologÃa Agropecuaria. Centro Regional Mendoza-San Juan. Estación Experimental Agropecuaria La Consulta; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Mendoza; Argentin
Use of natural and homeopathic remedies in children ailments
In recent decades the use of CAM (Complementary and Alternative Medicine) has increased significantly, not only among adults but also in the pediatric population. Perceived efficacy of homeopathic or natural treatments, fear of drug adverse effects, dissatisfaction with conventional medicine, and the need for more personal attention are the main reasons given by parents who treat their children with homeopathy.In the present paper the use of natural and homeopathic remedies  for the treatment of children ailments are considered. In particular we focus on minor disorders of early childhood with a major impact on the well-being of the whole family, namely infant colic, teething, upper respiratory tract infections (URTIs) and tonsillopharyngitis. The results of recent studies on homeopathic products for the treatment of these disorders are be presented and discussed
Consequences of postnatal stress: maternal separation in rats induces long-lasting changes on glutamate transporters
Background: There is increasing evidence that environmental factors, particularly stressful events experienced early in life, increase the risk of developing a psychiatric illness and/or a behavioural disorder. The aim of this study was to evaluate the effects of acute and chronic maternal separation (AMS and CMS) plus cold stress on the expression patterns of Glutamate Transporters (TGlus) in the developing and young adult Central Nervous System (CNS). As regulation of Glutamate (Glu) extracellular levels is of key importance, sodium-dependent Glu uptake using synaptosome-enriched fractions isolated from Frontal Cortex (FC) and Hippocampus (Hic) was also studied. Results: In animals under AMS stress found that Glu uptake decreases with respect to control groups. Meanwhile in CMS did not observe changes on Glu uptake in adult animals. These data would suggest the existence of an adaptive mechanism that could compensate the effect of AMS and CMS plus cold stress on glutamate uptake. Western blotting was performed in homogenates prepared from FC and Hic from both neonate and young adult rat brains. These blots exposed that homogenates include GLT-1 and EAAC-1 proteins and their levels varied in different areas of the rat brain and with the age of animals. Conclusions: During early postnatal life, exposure to various stressors lead to the development of various neurological, psychiatric, neurodegenerative and behavioral disorders, expressible in adult life in the case of chronic stress. These results demonstrate that adverse early life events have profound and persistent effects on brain function and may represent a risk factor for the development of psychopathology later life.Fil: Odeon, Maria Mercedes. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas (i); ArgentinaFil: Salatino, Adrián Emanuel. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas (i); ArgentinaFil: Acosta, Gabriela Beatriz. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas (i); Argentina. Universidad de Buenos Aires. Facultad de Farmacia y BioquÃmica. Departamento de Ciencias Biológicas. Cátedra de FisiopatologÃa; Argentin
A Frequency Selective Surface based focal plane receiver for the OLIMPO balloon-borne telescope
We describe here a focal plane array of Cold-Electron Bolometer (CEB)
detectors integrated in a Frequency Selective Surface (FSS) for the 350 GHz
detection band of the OLIMPO balloon-borne telescope. In our architecture, the
two terminal CEB has been integrated in the periodic unit cell of the FSS
structure and is impedance matched to the embedding impedance seen by it and
provides a resonant interaction with the incident sub-mm radiation. The
detector array has been designed to operate in background noise limited
condition for incident powers of 20 pW to 80 pW, making it possible to use the
same pixel in both photometric and spectrometric configurations. We present
high frequency and dc simulations of our system, together with fabrication
details. The frequency response of the FSS array, optical response measurements
with hot/cold load in front of optical window and with variable temperature
black body source inside cryostat are presented. A comparison of the optical
response to the CEB model and estimations of Noise Equivalent power (NEP) is
also presented
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