563 research outputs found

    Soil carbon dynamic associated to land-use changes in semi-arid forests of Argentina

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    Fil: Conti, G. Universidad Nacional de CĂłrdoba. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Instituto Multidisciplinario de BiologĂ­a Vegetal; Argentina.Fil: Conti, G. Universidad Nacional de CĂłrdoba. Facultad de Ciencias Exactas, FĂ­sicas y Naturales. Departamento de Diversidad BiolĂłgica y EcologĂ­a; Argentina.Fil: Kowaljow, E. Universidad Nacional de CĂłrdoba. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Instituto Multidisciplinario de BiologĂ­a Vegetal; Argentina.Fil: Kowaljow, E. Universidad Nacional de CĂłrdoba. Facultad de Ciencias Exactas, FĂ­sicas y Naturales. Departamento de Diversidad BiolĂłgica y EcologĂ­a; Argentina.Fil: Baptist, F. Biotope; Francia.Fil: Rumpel, C. Centre national de la recherche scientifique; Francia.Fil: Cuchietti, A. Universidad Nacional de CĂłrdoba. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Instituto Multidisciplinario de BiologĂ­a Vegetal; Argentina.Fil: Cuchietti, A. Universidad Nacional de CĂłrdoba. Facultad de Ciencias Exactas, FĂ­sicas y Naturales. Departamento de Diversidad BiolĂłgica y EcologĂ­a; Argentina.Fil: DĂ­az, S. Universidad Nacional de CĂłrdoba. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Instituto Multidisciplinario de BiologĂ­a Vegetal; Argentina.Fil: DĂ­az, S. Universidad Nacional de CĂłrdoba. Facultad de Ciencias Exactas, FĂ­sicas y Naturales. Departamento de Diversidad BiolĂłgica y EcologĂ­a; Argentina.Land-use change represents one of the main drivers of global climatic change, affecting the amount and quality of organic matter (OM) in soils worldwide. A reduction in the amount of biomass due to forest management is expected to affect both the amount of new OM going into the soil and its microbial decomposability due to changes in soil environmental conditions. These changes should impact soil microbial communities, their activity and decomposition rates, affecting the amount and quality of organic carbon (OC) remaining in the soil. In order to obtain information on the effect of land-use change on the OM quantity and quality, its origin and its degree of stabilization (i.e., microbial decomposability), we characterized the amount of OC, the lignin and polysaccharide compounds by wet chemical analysis, as well as basal respiration rates across a disturbance gradient (n=20) in a semiarid Chaco forest of central Argentina. Disturbance reduced the amount and quality of litterfall, reflected in a reduction in SOM content. Soil carbohydrates content followed the same trend but lignin was not affected by land-use change. Although basal CO2 effluxes showed the same pattern than SOM content, when normalized per OC content, they showed the opposite trend, with higher CO2 released per C in sites with lower OC and carbohydrates content. Our results support the idea that in the semi-arid Chaco forest, chemically labile compounds are more vulnerable to disturbance, but also that OM could be protected and stabilized regardless of its chemical identity.Fil: Conti, G. Universidad Nacional de CĂłrdoba. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Instituto Multidisciplinario de BiologĂ­a Vegetal; Argentina.Fil: Conti, G. Universidad Nacional de CĂłrdoba. Facultad de Ciencias Exactas, FĂ­sicas y Naturales. Departamento de Diversidad BiolĂłgica y EcologĂ­a; Argentina.Fil: Kowaljow, E. Universidad Nacional de CĂłrdoba. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Instituto Multidisciplinario de BiologĂ­a Vegetal; Argentina.Fil: Kowaljow, E. Universidad Nacional de CĂłrdoba. Facultad de Ciencias Exactas, FĂ­sicas y Naturales. Departamento de Diversidad BiolĂłgica y EcologĂ­a; Argentina.Fil: Baptist, F. Biotope; Francia.Fil: Rumpel, C. Centre national de la recherche scientifique; Francia.Fil: Cuchietti, A. Universidad Nacional de CĂłrdoba. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Instituto Multidisciplinario de BiologĂ­a Vegetal; Argentina.Fil: Cuchietti, A. Universidad Nacional de CĂłrdoba. Facultad de Ciencias Exactas, FĂ­sicas y Naturales. Departamento de Diversidad BiolĂłgica y EcologĂ­a; Argentina.Fil: DĂ­az, S. Universidad Nacional de CĂłrdoba. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Instituto Multidisciplinario de BiologĂ­a Vegetal; Argentina.Fil: DĂ­az, S. Universidad Nacional de CĂłrdoba. Facultad de Ciencias Exactas, FĂ­sicas y Naturales. Departamento de Diversidad BiolĂłgica y EcologĂ­a; Argentina.EcologĂ­

    Ecologisch gericht suppleren, nu en in de toekomst: het ontwerp meerjarenplan voor monitoring en (toepassingsgericht) onderzoek

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    Zandsuppleties. Het programma “Ecologisch gericht suppleren, nu en in de toekomst” is een onderzoeks- en monitoringsprogramma voor de middellange termijn (2009-2014) met als doelstelling meer inzicht te krijgen of, en in welke mate, zandsuppleties van invloed zijn op natuurwaarden en op welke wijze zandsuppleties in de nabije toekomst kunnen bijdragen aan de opgaven van veiligheid samen met natuurbehoud en -ontwikkeling. Het programma moet leiden tot een optimalisatie van natuurbescherming van het kustecosysteem en een dynamisch beheer en behoud van de kustlijn

    Negative parental responses to coming out and family functioning in a sample of lesbian and gay young adults

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    Parental responses to youths' coming out (CO) are crucial to the subsequent adjustment of children and family. The present study investigated the negative parental reaction to the disclosure of same-sex attraction and the differences between maternal and paternal responses, as reported by their homosexual daughters and sons. Participants' perceptions of their parents' reactions (evaluated through the Perceived Parental Reactions Scale, PPRS), age at coming out, gender, parental political orientation, and religiosity involvement, the family functioning (assessed through the Family Adaptability and Cohesion Evaluation Scales, FACES IV), were assessed in 164 Italian gay and lesbian young adults. Pearson correlation coefficients were calculated to assess the relation between family functioning and parental reaction to CO. The paired sample t-test was used to compare mothers and fathers' scores on the PPRS. Hierarchical multiple regression was conducted to analyze the relevance of each variable. No differences were found between mothers and fathers in their reaction to the disclosure. The analysis showed that a negative reaction to coming out was predicted by parents' right-wing political conservatism, strong religious beliefs, and higher scores in the scales Rigid and Enmeshed. Findings confirm that a negative parental reaction is the result of poor family resources to face a stressful situation and a strong belief in traditional values. These results have important implications in both clinical and social fields

    Potent cytotoxic effects of Calomeria amaranthoides on ovarian cancers

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    <p>Abstract</p> <p>Background</p> <p>Ovarian cancer remains the leading cause of death from gynaecological malignancy. More than 60% of the patients are presenting the disease in stage III or IV. In spite of combination of chemotherapy and surgery the prognosis stays poor for therapy regimen.</p> <p>Methods</p> <p>The leaves of a plant endemic to Australia, <it>Calomeria amaranthoides</it>, were extracted and then fractionated by column chromatography. <it>In vitro </it>cytotoxicity tests were performed with fractions of the plant extract and later with an isolated compound on ovarian cancer cell lines, as well as normal fibroblasts at concentrations of 1-100 μg/mL (crude extract) and 1-10 μg/mL (compound). Cytotoxicity was measured after 24, 48 and 72 hours by using a non-fluorescent substrate, Alamar blue.</p> <p><it>In vivo </it>cytotoxicity was tested on ascites, developed in the abdomen of nude mice after inoculation with human OVCAR<sub>3 </sub>cells intraperitoneally. The rate of change in abdomen size for the mice was determined by linear regression and statistically evaluated for significance by the unpaired t test.</p> <p>Results</p> <p>Two compounds were isolated by chromatographic fractionation and identified by <sup>1</sup>H-NMR, <sup>13</sup>C-NMR and mass spectrometry analyses, EPD, an α-methylene sesquiterpene lactone of the eremophilanolide subtype, and EPA, an α-methylene carboxylic acid.</p> <p>Cytotoxicity of EPD for normal fibroblasts at all time points IC<sub>50 </sub>was greater than 10 μg/mL, whereas, for OVCAR<sub>3 </sub>cells at 48 hours IC<sub>50 </sub>was 5.3 μg/mL (95% confidence interval 4.3 to 6.5 μg/mL).</p> <p>Both, the crude plant extract as well as EPD killed the cancer cells at a final concentration of 10 μg/mL and 5 μg/mL respectively, while in normal cells only 20% cell killing effect was observed. EPA had no cytotoxic effects.</p> <p>Changes in abdomen size for control versus Cisplatin treated mice were significantly different, P = 0.023, as were control versus EPD treated mice, P = 0.025, whereas, EPD versus Cisplatin treated mice were not significantly different, P = 0.13.</p> <p>Conclusions</p> <p>For the first time both crude plant extract from <it>Calomeria amaranthoides </it>and EPD have been shown to have potent anti-cancer effects against ovarian cancer.</p

    Race, Slavery, and the Expression of Sexual Violence in Louisa Picquet, The Octoroon

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    Historically, victims of sexual violence have rarely left written accounts of their abuse, so while sexual violence has long been associated with slavery in the United States, historians have few accounts from formerly enslaved people who experienced it first-hand. Through a close reading of the narrative of Louisa Picquet, a survivor of sexual violence in Georgia and Louisiana, this article reflects on the recovery of evidence of sexual violence under slavery through amanuensis-recorded testimony, the unintended evidence of survival within the violent archive of female slavery, and the expression of “race” as an authorial device through which to demonstrate the multigenerational nature of sexual victimhood

    New insights into perinatal testicular torsion

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    Perinatal testicular torsion is a relatively rare event that remains unrecognized in many patients or is suspected and treated accordingly only after an avoidable loss of time. The authors report their own experience with several patients, some of them quite atypical but instructive. Missed bilateral torsion is an issue, as are partial torsion, possible antenatal signs, and late presentation. These data are discussed together with the existing literature and may help shed new light on the natural course of testicular torsion and its treatment. The most important conclusion is that a much higher index of suspicion based on clinical findings is needed for timely detection of perinatal torsion. It is the authors’ opinion that immediate surgery is mandatory not only in suspected bilateral torsions but also in cases of possible unilateral torsions. There is no place for a more fatalistic “wait-and-see” approach. Whenever possible, even necrotic testes should not be removed during surgery because some endocrine function may be retained
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