106 research outputs found
Family Reunification among Two Groups of Runaway Adolescents Utilizing Emergency Shelters
Limited research has addressed reunification of runaway youths with their families following an emergency shelter stay; however, recent studies have shown that those who reunify with their families following a shelter stay have more positive outcomes than those relocated to other residences. This study evaluated differences between two samples of runaway youth utilizing youth emergency shelters in New York (n = 155) and Texas (n = 195) and identified factors associated with reunification among these two groups of adolescents. Less than half (43.7%) of the youths were reunited with their families. Among New York runaway youths, those who had lived primarily with someone other than a parent before shelter admission, were physically abused, or neglected were less likely to return home. Among youths admitted to emergency shelter services in Texas, those with longer shelter stays, living primarily with someone other than a parent before shelter admission, or being pregnant or a parent were less likely to reunify. This study provides valuable information concerning family reunification following shelter service use; however, additional research is needed to delineate youth, family, and shelter system factors that distinguish successful from unsuccessful reunification over an extended period of time
Exsudação de ácidos orgânicos por dois cultivares de arroz (Oryza sativa L.), submetidos a nÃveis tóxicos de alumÃnio.
Um dos principais mecanismos de tolerância ao Al, manifestado por várias espécies vegetais, baseia-se na capacidade que as plantas teriam de sintetizar e exsudar para o meio de cultivo certos ácidos orgânicos. Estes ácidos orgânicos seriam capazes de complexar a forma monomérica e mais tóxica do Al, diminuindo sua fitotoxicidade. A indução à exsudação parece ser especificamente regulada pelo Al e o sÃtio de sua secreção parece ser a zona distal de transição..
Amenização dos efeitos tóxicos do alumÃnio pela adição de ácidos orgânicos à solução nutritiva.
Um dos principais mecanismos de tolerância ao Al, manifestado por várias espécies vegetais, baseia-se na capacidade que as plantas teriam de sintetizar e exsudar para o meio de cultivo certos ácidos orgânicos. Estes ácidos orgânicos seriam capazes de complexar a forma monomérica e mais tóxica do Al no meio de cultivo, diminuindo sua absorção e, portanto, diminuindo a intensidade da fitotoxidade. A indução à exsudação parece ser especificamente regulada pelo Al e o sÃtio de sua secreção parece ser a zona distal de transição nas raÃzes..
Efeito do alumÃnio sobre parâmetros de crescimento em dois cultivares de arroz (Oryza sativa L.).
O Al absorvido pelas plantas tende a se acumular preferencialemente nos ápices radiculares, região da raiz tida como o principal sÃtio da ação inibitória do AL. Seja pela sua interferência na dinâmica do citoesqueleto, agindo sobre microtúbulos e filamentos de actina, seja pela inibição na absorção de Ca a inibição do alongamento radicular induzida por Al constitui um dos primeiros e mais importantes efeitos de cátion nas plantas..
Changes in antioxidative defense system of Stizolobium aterrimum and Canavalia ensiformis exposed to arsenic
The present work evaluated the antioxidant responses of Stilozobium aterrimum and Canavalia ensiformis after exposure to arsenic (As). Plants of these two species with the first pair of fully expanded cotyledonary leaves, grown in nutrient solution, pH 5.5, were treated with 0.0 and 1.5 mg.L-1 of As. After 5 days, the effects of As on lipid peroxidation and antioxidant enzymes were measured. Lipid peroxidation increased in both roots and leaves after As treatment, especially in S. aterrimum. Superoxide dismutase (SOD) activity increased in the two parts of the plants of both species with As treatment. Peroxidase (POX) activity, on the other hand, reduced with As treatment in S. aterrimum, but increased in C. ensiformis. Glutathione reductase (GR) increased in roots of both species, mainly in S. aterrimum. GR activity also increased in the leaves of C. ensiformis, but decreased in S. aterrimum. Under the experimental conditions of this study, C. ensiformis was considered to have antioxidant mechanisms slightly more efficient than S. aterrimum against reactive oxygen intermediates (ROIs). Keywords: arsenic, antioxidative mechanisms, lipid peroxidation, reactive oxygen intermediates
Efeito do alumÃnio sobre a absorção, o acúmulo e o fracionamento do fósforo em sorgo
O trabalho teve como objetivo estudar o efeito do Al sobre a absorção, o acúmulo e o fracionamento do P em duas cultivares de sorgo. As plantas foram expostas a nÃveis tóxicos de Al durante dez dias e, então, colhidas e determinados o crescimento em tamanho e produção de massa seca, os teores de Al e de P total e as diversas formas de P nas duas partes das plantas. Avaliou-se, também, o efeito do Al sobre a absorção de P pelas raÃzes de plantas intactas. O Al reduziu o crescimento da raiz seminal e a produção de matéria seca de raÃzes e parte aérea nas duas cultivares, especialmente na sensÃvel. Os teores de Al e de P total aumentaram nas raÃzes, mas não foram modificados na parte aérea nas duas cultivares. A absorção de P, entretanto, decresceu na presença de Al nas duas cultivares, principalmente na sensÃvel. O Al, de modo geral, modificou as concentrações das várias formas de P solúvel (Pi e Porg) e insolúvel (P RNA e Presidual), exceto a da forma P LIP. Algumas dessas modificações parecem ser importantes e podem estar relacionadas com o mecanismo de tolerância ao Al em sorgo.The objective of this work was to evaluate Al effect on uptake, accumulation and fractionation of P in two sorghum cultivars. Plants were treated with toxic levels of Al during ten days and then they were harvested and growth, dry matter yield, Al and total P contents and concentrations of the various P forms in the two parts of the plants were determined. Aluminum effect on P uptake was also evaluated in intact plants. Aluminum reduced the growth of the seminal root and dry matter yield in roots and tops of both cultivars, especially in the sensitive one. Aluminum and P contents increased in roots but did not change in the top of both cultivars. Phosphate uptake by roots, however, decreased in the presence of Al in both cultivars, especially in the sensitive one. Aluminum, in general, changed concentrations of all soluble (Pi e Porg) and insoluble P forms (P RNA e Presidual), except of the P LIP form. Some of these modifications seem to be important and may be related to Al tolerance mechanism in sorghum
Standardization of the normative group for the third version of the test of visual attention - TAVIS
He votes or she votes? Female and male discursive strategies in Twitter political hashtags
In this paper, we conduct a study about differences between female and
male discursive strategies when posting in the microblogging service
Twitter, with a particular focus on the hashtag designation process
during political debate. The fact that men and women use language in
distinct ways, reverberating practices linked to their expected roles in
the social groups, is a linguistic phenomenon known to happen in
several cultures and that can now be studied on the Web and on online
social networks in a large scale enabled by computing power. Here, for
instance, after analyzing tweets with political content posted during
Brazilian presidential campaign, we found out that male Twitter users,
when expressing their attitude toward a given candidate, are more prone
to use imperative verbal forms in hashtags, while female users tend to
employ declarative forms. This difference can be interpreted as a sign
of distinct approaches in relation to other network members: for
example, if political hashtags are seen as strategies of persuasion in
Twitter, imperative tags could be understood as more overt ways of
persuading and declarative tags as more indirect ones. Our findings help
to understand human gendered behavior in social networks and contribute
to research on the new fields of computer-enabled Internet linguistics
and social computing, besides being useful for several computational
tasks such as developing tag recommendation systems based on users'
collective preferences and tailoring targeted advertising strategies,
among others.FGW – Publications without University Leiden contrac
- …