Sample records for FRAGMENTACION NUCLEAR (nuclear fragmentation)
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Sample records 1 - 13 shown.



1

Temporalidades fragmentadas: La experiencia social de trabajadores petroleros de la Cuenca Neuquina

García, Analía
2009-06-01

Resumen en español Un debate muy prolífero en torno a las políticas de reglamentación sobre los oligopolios y sus resultados después de casi dos décadas ha tenido lugar desde la desregulación de la actividad de hidrocarburos. Al mismo tiempo, un foco de preocupación ha sido el alto nivel de conflictividad que ha tenido lugar en los pueblos históricamente dedicados a esta actividad económica. Por otro lado, la crisis económica ha permitido a las ciencias sociales actualizar los deb (mas) ates en torno al drama del desempleo en la última década. A raíz de estas cuestiones, nos preguntamos sobre la dinámica social que rodea la experiencia biográfica de los trabajadores de hidrocarburos de la Cuenca Neuquina. Construimos una relación entre el estado actual del capitalismo y el territorio de la producción de hidrocarburos con el objetivo de entender las expresiones de una subjetividad particular, que se construye alrededor de los horizontes de la vida caracterizados por una fragmentación del tiempo y el espacio. Luego, analizamos la dinámica de los trabajadores migrantes en dos pueblos: Rincón de los Sauces y Buta Ranquil, donde viven durante la semana de trabajo lejos de sus familias nucleares. Dentro de este marco, nos preguntamos acerca de la soledad y el desarraigo que revelan sus horizontes personales de vida. Resumen en inglés A very proliferous debate around the regulatory policies on oligopolies and their results after almost two decades has been taking place since the deregularization of the hydrocarbon activity. At the same time, a focus of concern has been the high level of conflictivity that has been taking place on villages historically dedicated to this economic activity. On the other hand, the economic crisis has allowed social science to update the debates around the drama of unemploy (mas) ment that characterized the economic reforms of the last decade. Following these issues, we inquire on the social dinamics that encircles the biographic experiences of hydrocarbon workers of the Cuenca Neuquina. We build a relationship between the present state of capitalism and the territory of hydrocarbon production with the objective of understanding the expressions of a particular subjectivity that is built around horizons of life characterized by a fragmentation of time and space. Then, we analyze the dynamics of migrant workers in two villages: Rincón de los Sauces y Buta Ranquil, where they live during the labor week away from their nuclear families. Within this framework, we consider about the lonelyness and uprooting that their personal horizons of life reveal.

Scientific Electronic Library Online (Spanish)

2

Estudio del daño celular producido por isquemia cerebral, en un modelo de rata. Determinación de la presencia de apoptosis/ Cellular injury study caused by cerebral ischemia in a rat model. Determination of apoptosis presence

Ortíz Plata, Alma; Sandoval, Carlos; Uribe, Paul; Guevara, Jorge; Rembao, Daniel; Nader, Juan; de la Cruz Hernández Hernández, Fidel
2004-12-01

Resumen en español La enfermedad vascular cerebral constituye una de las primeras causas de discapacidad y mortalidad en el mundo. En este trabajo, se analizó el daño celular isquémico por oclusión de la arteria cerebral media en ratas a distintos tiempos (5, 10, 12-15, 30 y 60 min), n diferentes regiones cerebrales (frontal, parietal, occipital e hipocampo), que fueron, analizadas por microscopia óptica, microscopia electrónica, LM-PCR (Ladder Assay-Polymerase Chain Reaction) y TUNEL (mas) (Terminal deoxinucleotidil transferasa mediated dUTP Nick End Labeling). A los 5 min se observaron cambios hipóxicos caracterizados por células de volumen reducido y núcleos picnóticos. A los 12 min aparecieron en todas las regiones cerebrales y con predominio en occipital e hipocampo, cambios sugestivos de apoptosis consistentes en células individuales con condensación de la cromatina, disminución de volumen celular y ausencia de edema. Al microscopio electrónico se observó condensación de la cromatina en algunas células. El LM-PCR mostró a partir de los 12 min de isquemia, la característica fragmentación en escalera del DNA que se encuentra en la apoptosis. La prueba de TUNEL fue positiva a los 12 min en hipocampo y lóbulo occipital. Estos resultados sugieren que la apoptosis activa, ocurre en las células cerebrales, en fases tempranas de la muerte neuronal isquémica a partir de los 12 min de isquemia focal. Resumen en inglés The cerebral vascular disease is one of the main reasons of incapacity and mortality in the world. Here it was analyzed the cellular ischemic injury by middle cerebral artery occlusion in a rat model at several times (5, 10, 12-15, 30 and 60 minutes), in different cerebral regions (frontal, parietal, occipital and hippocampus), that were analyzed by light microscopy, electron microscopy, LM-PCR (Ladder Assay-Polymerase Chain Reaction) and TUNEL (Terminal deoxinucleotidil (mas) transferasa mediated dUTP Nick End Labeling). At five minutes hypoxic changes as loss of cytoplasmic volume and nuclear pyknosis were observed. At 12 minutes were found changes suggesting apoptosis such as individual cells with chromatin and cytoplasmic condensation but without edema in all cerebral regions, predominantly in occipital and hippocampus. Under electron microscopy so me cells with chromatin condensation were observed. LM-PCR technique shows the typical DNA ladder fragmentation, starting at 12 minutes. TUNEL test was positive in neurons at 12 minutes in occipital and hippocampus regions. These results suggest that apoptosis in cerebral cells start at 12 minutes after focal cerebral ischemia. It might evidence the presence of cellular active processes of neuronal death at early times of ischemia.

Scientific Electronic Library Online (Spanish)

3

Evaluación de la calidad del espermatozoide humano: comparación entre la integridad del ADN espermático y variables del semen/ Evaluation of the quality of the human spermatozoon: comparison between spermatic DNA integrity and semen variables

Cruz, Ibis; Colmenares, Melisa; Berrueta-Carrillo, Leidith; Gomez-Perez, Roald; Montes, Henry; Berrueta, Lisbeth; Salmen, Siham; Osuna, Jesús Alfonso
2010-03-01

Resumen en español El análisis del semen no tiene valor predictivo absoluto de fertilidad, pero informa sobre el potencial de fertilidad del varón, el cual está relacionado con la calidad de sus espermatozoides y de otras variables del semen. Se ha comprobado que los valores del semen pueden mostrar gran variabilidad en un mismo individuo. Esto explica por que un hombre cuyas variables no son absolutamente normales, puede lograr un embarazo en su pareja. Dentro de los parámetros tradici (mas) onalmente utilizados en la evaluación clínica de la fertilidad masculina se encuentran: la concentración, la movilidad y la morfología espermática; además de medir estas variables, nuevos procedimientos han sido incorporados para evaluar la capacidad funcional de los espermatozoides, uno de los que ha alcanzado particular importancia en la última década es la medida de la integridad del ADN nuclear. La fragmentación del ADN consiste en interrupciones en las cadenas simples o dobles del ADN que ocurre frecuentemente en la muestra de pacientes no fértiles. Se ha llevado a cabo un estudio clínico, en muestras de semen provenientes de pacientes que acudieron al laboratorio de Andrología de la Universidad de los Andes, colectadas entre marzo del 2007 y marzo del 2009, a fin de establecer comparaciones entre los parámetros convencionales y la medición de la integridad de la cromatina espermática, mediante citometría de flujo. Los resultados obtenidos mostraron correlaciones evidentes entre los parámetros convencionales y la integridad del ADN espermático y aportan datos de gran utilidad en el estudio clínico integral de la infertilidad masculina. Resumen en inglés Semen analysis does not have an absolute predictive value on fertility, however it is a reflection of male fertility potential, which is related to its spermatozoa quality and other semen variables. Great variability in human semen parameters has been demonstrated within a single individual, an observation that could explain why a male with low semen quality can successfully fertilize an egg. Although conventional semen analysis, such as sperm concentration, motility and (mas) morphology, provide important information about the clinical status of male fertility, new procedures to predict the sperm functional capability have been developed in the last decade, such as analysis of nuclear DNA integrity, which have improved considerably the clinical diagnosis of male infertility, and increased the knowledge about spermatozoa function. DNA fragmentation consist in interruptions, both in single and double DNA strains, that frequently occur in sperm samples from infertile patients. We have conducted a clinical study in semen samples from patients who have attended the Andrology laboratory of the University of Los Andes, between March 2007 and March 2009. The aim of this study was to compare sperm DNA integrity, analyzed by flow cytometry, with traditional semen parameters. Our results show remarkable correlations between conventional human semen variables and sperm chromatin integrity, contributing to asses an integral evaluation of sperm quality allowing the analysis of its fertilizing potential in clinical studies.

Scientific Electronic Library Online (Spanish)

4

Systematic investigation of the drip-line nuclei Li-11 and Be-14 and their unbound subsystems Li-10 and Be-13

Simon, H.; Meister, M.; Aumann, T.; García Borge, María José; Chulkov, L. V.; Pramanik, U. Datta; Elze, Th. W.

36 pages, 10 figures, 8 tables, 3 appendices.-- PACS nrs.: 27.20.+n; 24.70.+s.-- Printed version published Jul 15, 2007. | Fragmentation reactions in a carbon target with beams of Li-11 and Be-14 at relativistic energies have been studied in a kinematically complete experiment at the ALADIN-LAND set...

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5

New results on the halo structure of B-8

Smedberg, M. H.; Baumann, T.; Aumann, T.; Axelsson, L.; Bergmann, U.; García Borge, María José; Cortina-Gil, D.

7 pages, 1 table, 3 figures.-- PACS nrs.: 25.60.Gc; 27.20.+n. | The longitudinal momentum distribution of Be-7 fragments after fragmentation of B-8 and the one-proton removal cross section (σ(-1p)) in a carbon target were measured at 1440 MeV/u with the fragment separator FRS used as an energy-loss ...

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6

Neutron single spin asymmetries from semi-inclusive deep inelastic scattering off transversely polarized He-3

Scopetta, Sergio

10 pages, 3 figures.-- PACS nrs.: 13.60.Hb, 13.85.Hd, 13.85.Ni, 13.87.Fh.-- ISI Article Identifier: 000245333000018.-- ArXiv pre-print available at: http://arxiv.org/abs/hep-ph/0612354 | A study of semi-inclusive deep inelastic scattering off transversely polarized He-3 is presented. The formal expr...

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7

Longitudinal momentum distributions of C-16,C-18 fragments after one-neutron removal from C-17,C-19

Baumann, T.; García Borge, María José; Geissel, H.; Lenske, H.; Markenroth, K.; Schwab, W.; Smedberg, M. H.

6 pages, 5 figures.-- PACS nrs.: 25.60.Gc; 25.70.Mn; 27.20.+n.-- ArXiv pre-print available at: http://arxiv.org/abs/nucl-ex/9810011 | The fragment separator FRS at GSI was used as an energy-loss spectrometer to measure the longitudinal momentum distributions of C-16,C-18 fragments after one-neutron ...

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8

Invariant-mass spectroscopy of Li-10 and Li-11

Zinser, M.; Humbert, F.; Nilsson, T.; Schwab, W.; Simon, H.; Aumann, T.; García Borge, María José; Chulkov, L. V.

26 pages, 5 tables, 10 figures.-- PACS nrs.: 25.60.+v; 27.20.+n; 25.70.Mn; 25.70.De. | Break-up of secondary Li-11 ion beams (280 MeV/nucleon) on C and Pb targets into Li-9 and neutrons is studied experimentally. Cross sections and neutron multiplicity distributions are obtained, characterizing diff...

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9

Invariant mass spectrum and alpha-n correlation function studied in the fragmentation of He-6 on a carbon target

Aleksandrov, D.; Aumann, T.; Axelsson, L.; Baumann, T.; García Borge, María José; Chulkov, L. V.; Cub, J.

13 pags, 5 figures.-- PACS nrs.: 24.60.−t; 25.70.Ef; 27.20.+n. | Momentum distributions and invariant mass spectra from the breakup of He-6 ions with an energy of 240 MeV/u interacting with a carbon target have been studied. The data were used to extract information about the reaction mechanism whic...

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10

Inducción de apoptosis por el principio activo citotóxico de Espeletia killipii Cuatr. sobre líneas celulares humanas/ Indução de apoptose pelo princípio ativo citotóxico de Espeletia killipii Cuatr. sobre linhagens celulares humanas/ Induction of apoptosis by the citotoxic active principle of Espeletia killipii Cuatr. on human cell lines

Castro, Clemencia de; Riveros de Murcia, Tulia; Jaimes, Gustavo; Téllez Alfonso, Alba N.
2007-12-01

Resumen en portugués O acetato de longipilina, o princípio ativo citotóxico, isolado de Espeletia killipii Cuatr., uma planta endêmica de Colômbia, é uma sesquiterpenlactona que tem a propriedade de induzir apoptose em algumas linhagens celulares de câncer de mama como MCF-7 e CSC-1595 (obtidas do Instituto Nacional de Cancerologia, Bogotá - Colômbia). Reconhecimento morfológico, método de Tunel e citometria de fluxo foram utilizados para avaliar a atividade apoptótica. Os resultados mostraram que a longipilina é um potencial agente antitumoral. Resumen en inglés Longipilin acetate is the compound exhibiting cytotoxicity, isolated from endemic plant specie from Colombia, South America, Espeletia killipii Cuatr. Longipilin acetate is a sesquiterpenelactone having the ability to induce apoptosis in several breast cancer cell-lines like MCF-7 y CSC-1595 (obtained from National Cancer Institute, Bogotá Colombia), Morphological examination, nuclear DNA fragmentation, tunel and flow cytometry were used to evaluate apoptosis. Therefore longipilin acetate is a compound showing potential as an antitumor agent.

Scientific Electronic Library Online (Spanish)

11

He-8 - He-6: a comparative study of electromagnetic fragmentation reactions

Meister, M.; Markenroth, K.; Aleksandrov, D.; Aumann, T.; Baumann, T.; García Borge, María José; Chulkov, L. V.

14 pages, 1 table, 2 figures.-- PACS nrs.:27.20.+n; 24.70.+.-- Available online Oct 8, 2001. | Dissociation of a 227 MeV/u He-8 beam in a lead target has been studied in a kinematically complete experiment. The results are compared with similar data from the well-known halo nucleus He-6. Coulomb-nuc...

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12

Halo excitations in fragmentation of He-6 at 240 MeV/u on carbon and lead targets

Aleksandrov, D.; Aumann, T.; Axelsson, L.; Baumann, T.; García Borge, María José; Chulkov, L. V.; Cub, J.

14 pages, 6 figures.-- PACS nrs.: 27.20.+n; 24.70.+. | Dissociation of a 240 MeV/u beam of He-6, incident on carbon and lead targets, has been studied in kinematically complete experiments to investigate low-lying excitation modes in the halo nucleus He-6. It is shown that alignment effects characte...

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13

8He-6He: a comparative study of nuclear fragmentation reactions

Markenroth, K.; Meister, M.; Eberlein, B.; Aleksandrov, D.; Aumann, T.; Axelsson, L.; Baumann, T.; García Borge, María José

19 pages, 3 tables, 6 figures.-- PACS nrs.: 27.20.+n; 24.70.+s; 25.06.-t.-- Available online Dec 4, 2000. | Dissociation of 227 MeV/u 8He in a carbon target has been studied in kinematically complete experiments. The data include the relative energy spectrum, angular distributions in the neutron kno...

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