oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

4 ( 1 )

3 ( 1 )

2019 ( 125 )

2018 ( 157 )

Custom range...

Search Results: 1 - 10 of 81723 matches for " Maria Elena;Orozco "
All listed articles are free for downloading (OA Articles)
Page 1 /81723
Display every page Item
In vitro rhizogenesis: histoanatomy of Cedrela odorata (Meliaceae) microcuttings
Millán-Orozco,Liliana; Corredoira,Elena; San José,Maria del Carmen;
Revista de Biología Tropical , 2011,
Abstract: cedrela odorata (meliaceae) is considered as one of the most valuable forest tree in the tropics. clonal propagation of this species provide an alternative method to propagate superior genotypes, being the production of good quality adventitious roots one of the most important steps in micropropagation techniques. the sequence of anatomical changes that takes place during the formation of adventitious roots in shoots of cedrela odorata cultured in vitro is described in this study. eigth-week-old shoots, from multiplication cultures, were rooted in murashige and skoog′s medium (1962) with half- strength macronutrients and with 0 or 1mg/l indole-3-butyric acid (iba). between 12 and 24h after the start of rooting, some cambium, phloem and interfascicular parenchyma cells became dense cytoplasm, nuclei with prominent nucleoli and the first cell divisions were observed, especially in shoots treated with auxin (dedifferentiation phase). after 3-4 days, the number of dedifferentiated cells and mitotic divisions increased considerably, and the formation of groups of some 30-40 meristematic cells (meristemoids) was observed (induction phase). the first primordial roots developed from the 4th-5th day. the vascular tissues of these primordia connected to those of the explant, and roots began to emerge from the base by day 6. development of the primordial roots was similar in the control shoots and shoots treated with 1mg/l iba, although there were more roots per explant in the latter. rev. biol. trop. 59 (1): 447-453. epub 2011 march 01.
Distribución y determinantes sociodemográficos de la conducta suicida en México
Borges, Guilherme;Medina-Mora, Maria Elena;Orozco, Ricardo;Ouéda, Christiane;Villatoro, Jorge;Fleiz, Clara;
Salud mental , 2009,
Abstract: introduction mexico has seen constant increases in the rate of completed suicide in the last decades, especially among youth. the mexican population between 1 5-24 years of age is currently the most affected, with 28% of all suicides in 2007. in this context of increasing suicide mortality, the study of suicide-related behaviors, that is, suicidal ideation, plans, gestures and suicide attempts, has special relevance. all of these are immediate precursors to death by suicide and independent risk factors of subsequent suicide attempts and completed suicides. episodes that do not result in death, can lead to serious, long-term consequences in one's physical health, as well as being an important cause of psychological suffering on the part of the individual and his/her family. up until now, research in our country has emphasized the prevalence of lifetime suicidal behavior and its associated factors. however, the current (12-month) prevalences are indispensable in order to define the demographic profile and clinical needs, and to build risk profiles for immediate application by the clinics treating these individuals. objectives to report the prevalence and sociodemographic characteristics of suicide-related behaviors in the past 12 months in a nationally representative sample of respondents from the encuesta nacional de adicciones (ena) of 2008. methods cross-sectional prevalence study which obtained data from a nationally-representative sample of 22 966 individuals, between the ages of 12 and 65, during 2008, who answered the section on suicidal behaviors. the response rate was 77%. twelve-month prevalences of suicidality are reported according to different sociodemographic and economic factors. multiple logistic regression models for odds ratios and 95% confidence intervals, corrected for the study design, are reported. results we found the prevalence of any suicidal ideation to be 8.79% (ranging from 4.2 to 6.2%, depending on the question used), the prevalence of a s
Suicidio y conductas suicidas en México: retrospectiva y situación actual
Borges,Guilherme; Orozco,Ricardo; Benjet,Corina; Medina-Mora,Maria Elena;
Salud Pública de México , 2010, DOI: 10.1590/S0036-36342010000400005
Abstract: objective. to summarize the epidemiology of completed suicide and suicidal behavior in mexico. material and methods. national data registries on mortality from the year 1970 to 2007 and cross-sectional surveys were used to analyze suicide mortality and suicidal behavior. results. the suicide rate grew 275% from 1970 to 2007. suicide has been increasing among mexicans 15-29 years old since 1970. in adults aged 18-29 years the lifetime prevalence of ideation was 9.7%, and attempt 3.8%. about 6,601,210 mexicans had suicidal thoughts, 593,600 attempted suicide and 99,731 used some sort of medical service as a direct consequence of the latter in the year prior to the survey. conclusions. suicide and suicide-related behaviors are significant public health problems and, as such, actions are urgently required to identify and treat persons with suicidal thoughts, assess suicidal risk in patients with psychiatric disorders and implement population interventions.
In vitro rhizogenesis: histoanatomy of Cedrela odorata (Meliaceae) microcuttings
Liliana Millán-Orozco,Elena Corredoira,Maria del Carmen San José
Revista de Biología Tropical , 2011,
Abstract: Cedrela odorata (Meliaceae) is considered as one of the most valuable forest tree in the tropics. Clonal propagation of this species provide an alternative method to propagate superior genotypes, being the production of good quality adventitious roots one of the most important steps in micropropagation techniques. The sequence of anatomical changes that takes place during the formation of adventitious roots in shoots of Cedrela odorata cultured in vitro is described in this study. Eigth-week-old shoots, from multiplication cultures, were rooted in Murashige and Skoog′s medium (1962) with half- strength macronutrients and with 0 or 1mg/l indole-3-butyric acid (IBA). Between 12 and 24h after the start of rooting, some cambium, phloem and interfascicular parenchyma cells became dense cytoplasm, nuclei with prominent nucleoli and the first cell divisions were observed, especially in shoots treated with auxin (dedifferentiation phase). After 3-4 days, the number of dedifferentiated cells and mitotic divisions increased considerably, and the formation of groups of some 30-40 meristematic cells (meristemoids) was observed (induction phase). The first primordial roots developed from the 4th-5th day. The vascular tissues of these primordia connected to those of the explant, and roots began to emerge from the base by day 6. Development of the primordial roots was similar in the control shoots and shoots treated with 1mg/l IBA, although there were more roots per explant in the latter. Rev. Biol. Trop. 59 (1): 447-453. Epub 2011 March 01. Cedrela odorata (Meliaceae) es una especie tropical de gran valor económico. La propagación in vitro de esta especie ofrece una vía alternativa para la clonación de genotipos superiores, siendo la formación de un buen sistema radical uno de los pasos claves en la micropropagación. En este trabajo analizamos la secuencia de cambios anatómicos que tienen lugar durante la formación de raíces adventicias en microestaquillas de Cedrela odorata. Para el enraizamiento se utilizó el medio MS con los macronutrientes reducidos a la mitad, suplementado con AIB 0 ó 1mg/l. A partir de las 12-24 horas del comienzo del enraizamiento, se observaron los primeros cambios en las células del cambium, del floema y del parénquima interfascicular (fase de diferenciación). Después de 3-4 días, aparecen grupos de células meristemáticas (fase de inducción). Los primordios se desarrollan después de 4-5 días, siendo visibles al exterior a partir del sexto día (fase de emergencia). El desarrollo de las raíces fue similar en ambos tratamientos, pero la presenc
Distribución y determinantes sociodemográficos de la conducta suicida en México
Guilherme Borges,Maria Elena Medina-Mora,Ricardo Orozco,Christiane Ouéda
Salud mental , 2009,
Abstract: En las últimas décadas, México ha visto incrementos constantes en la tasa de suicidio consumado, especialmente entre la población joven. La población mexicana de entre 15 y 24 a os de edad es hoy día de las más afectadas, con 28% de todos los suicidios en 2007. En este contexto de incremento de la mortalidad por suicidio cobra especial relevancia el estudio de las conductas relacionadas con el suicidio, es decir, la ideación suicida, los planes, los gestos y los intentos de suicidio. Todos éstos son precursores inmediatos de la muerte por suicidio y factores de riesgo independientes de intentos subsecuentes de suicidio y de suicidios consumados. Aun cuando estas conductas no lleven a la muerte, pueden acarrear consecuencias graves y de largo alcance para la salud física, y pueden constituir una importante causa de sufrimiento psicológico para el individuo y sus familiares. Hasta ahora, las investigaciones en nuestro país han enfatizado el conocimiento de la prevalencia y los factores asociados con la conducta suicida alguna vez en la vida. Las prevalencias actuales (últimos 12 meses) son, sin embargo, indispensables para definir el perfil demográfico y las necesidades clínicas de atención, y para elaborar perfiles de riesgo de aplicación inmediata para el clínico tratante de estos sujetos. Objetivos: En este trabajo reportamos las prevalencias y el perfil sociodemográfico de las conductas relacionadas con el suicidio en los últimos 12 meses en una muestra representativa de la población nacional. Para hacerlo se utilizó la Encuesta Nacional de Adicciones (ENA) del 2008...
Breast Cancer Screening: A Stochastic DEA Study  [PDF]
Maria Elena Bruni
American Journal of Operations Research (AJOR) , 2013, DOI: 10.4236/ajor.2013.36049
Abstract:

The goal of screening tests for breast cancer is early detection and treatment with a consequent reduction in mortality caused by the disease. Screening tests, however, might produce misleading diagnoses and potentially significant emotional, financial and health costs. The effectiveness of a breast screening program has effects on the quality of life of the target population. Even if the screening units regularly attain coverage targets, it remains essential to ensure that women receive the same high standard of service wherever they live. In order to assess the relative efficiency of individual screening units we use stochastic D.E.A. models, which can be used as reliable tools for external audit. The technique is tested on breast cancer screening data of two Italian regions.

Effect of Ethanol Deprivation and Re-Exposure on the Ethanol Drinking Behaviour of the High-Alcohol-Drinker (UChB) Rats  [PDF]
Lutske Tampier, Maria Elena Quintanilla
Journal of Behavioral and Brain Science (JBBS) , 2011, DOI: 10.4236/jbbs.2011.11001
Abstract: Alcohol addiction constitutes a major health problem in the general population, it is a complex pathology characterized by the development of tolerance, physical dependence and compulsive ethanol-seeking behaviour that often manifests as a chronic relapsing syndrome. 0ne of the major concerns in the treatment of alcohol-dependent patients is the prevention of relapse during periods of abstinence. The alcohol deprivation effect (ADE) is defined as a temporary increase in the voluntary intake of ethanol when it is reinstated after a period of alcohol deprivation and has been used as an animal model of relapse-like drinking. ADE can be used to evaluate the efficacy of possible pharmacological agents to prevent relapse drinking. The current study was undertaken to examine whether the high-alcohol-drinker UChB rats would display an ADE. Rats were given either continuous or periodic concurrent access to 10, 20% (vol/vol) of ethanol across deprivation cycles. UChB rats consuming ethanol voluntarily for two months, exhibit a robust ADE after a single deprivation period of two weeks. The increased alcohol intake during the early days of re-exposure, following a withdrawal phase, is attributed to a shift in preference towards the higher concentration of ethanol that might reflect an increase in craving for alcohol. Since an ADE is also observed in UChB rats, make this line of rats selectively bred for their high voluntary ethanol consumption, a useful model for study the efficacy of pharmacological agents for the treatment of relapse of alcohol consumption.
A Proposal for Estimating the Order Level for Slow Moving Spare Parts Subject to Obsolescence  [PDF]
Marcello Fera, Alfredo Lambiase, Maria Elena Nenni
iBusiness (IB) , 2010, DOI: 10.4236/ib.2010.23029
Abstract: During the last decade technologies have had a significant development in many areas, as military and civil protection, telecommunication and electrical distribution and production. Particularly in the mentioned areas we can find very complex products, with a cycle life generally longer than their components. Companies have thus the need to better manage the replacement of spare parts in order to reduce the holding costs and to satisfy the service level. In this paper authors analyse the state of the art about the spare parts logistic (SPL) problem for products characterized by a long cycle life and by slow moving spare parts subject to obsolescence. A new model to estimate the spare part order level is then proposed and tested on a simulated case.
The Role of Prolactin in the Evolution of Prostate Cancer  [PDF]
Maria Elena Hernandez, Michael J. Wilson
Open Journal of Urology (OJU) , 2012, DOI: 10.4236/oju.2012.223034
Abstract: Today there is significant information indicating an effect of prolactin on the prostate gland. It has been shown to be involved in mechanisms leading to the synthesis of some proteins such as PSA and cathepsin D, synthesis of citrate and accumulation of zinc. Also, at the behavioral level, prolactin is known to control some aspects of reproduction, including documentation on the physiology of the prostate and the possibility to trigger pathologies in this sex gland. Although the later still is not clear, there is a correlation between the level of prolactin and the presence of prostate pathologies. Thus, the aim of this review is to show how prolactin is involved in the progression of some pathologies of this male sexual gland.
CARACTERIZACIóN DE CONCENTRADOS DE COBRE PRODUCIDOS EN ARGENTINA PARA ANALIZAR LA FACTIBILIDAD DE LA INSTALACIóN DE UNA PLANTA PIROMETALúRGICA
Bazán,Vanesa; Sarquis,Pedro; Brandaleze,Elena; Orozco,Ivana;
Ingeniare. Revista chilena de ingeniería , 2010, DOI: 10.4067/S0718-33052010000300008
Abstract: the copper demand in the world has considerably increased during the last years due to the emergent markets, particularly the chinese market. nowadays, the mining projects for copper exploitation that are being developed in the north of argentina conclude with the concentrates exports. in our country different explorations have been carried out and in some cases high law of copper minerals are being exploited (0,5% - 0,8%). these minerals are free from impurities such as: sb,as,pb,bi and hg. this would lead to think that there are good prospects for the copper pyrometallurgy that have not been developed yet in our country. the conditions for the argentinean copper market present and unfulfilled demand for this metal, since there are industrial plants which convert metallic copper into final products leading to a new copper intermediate product import. this paper proposes to deepen the knowledge and to broaden the range of technical principles with can avoid exporting concentrates and instead it can provided raw material to a national metallurgical industry in order to produce metallic copper so that the domestic market will be supplied, thus importing raw material will no longer be necessary.
Page 1 /81723
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.