31 resultados para Endosperm absence


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Even though many schools and educational systems, from elementary to tertiary, state that they endorse antihomophobic policies, pedagogies, and programs, there appears to be an absence of education about, and affirmation of, bisexuality, and minimal specific attention to bi-phobia in curriculum, policy, and student welfare. Bisexuality continues to fall into the gap between the binary of heterosexuality and homosexuality across all educational sectors. These absences and erasures leave bisexual students, family members, and educators feeling silenced and invisibilized within school communities. Indeed, these absences and erasures have been considered a major factor in bisexual young people, family members, and educators in school communities experiencing worse mental, emotional, sexual, and social health than their homosexual or heterosexual counterparts. Also of interest is the persistence of bisexual erasure in adult-developed resources and programs, even though there is increasing evidence of sexual identities and practices in youth subcultures that are adopting shifting discursive and societal constructs of sexuality, characterized by notions of fluidity, ambisexuality, and a reluctance to label their sexuality according to the heterosexual/homosexual binary. The articles in this issue profoundly engage with and problematize the three impediments to education systems when those systems engage with sexual diversity instead of sexual duality, namely, erasure, exclusion by inclusion into gay and lesbian categories, and the absence of intersectionality (wherein other facets of identity and experience that interweave with sexuality are not taken into account, such as class, gender, Indigeneity/Aboriginality, ethnicity, geographical location, and religion). 

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A suboptimal in utero environment leads to fetal adaptations to ensure short-term survival but in the long-term may lead to disease when the postnatal growth does not reflect that in utero. This study examined the effect of IUGR on whole body insulin sensitivity and metabolic activity in adult rats. Female Wistar-Kyoto rats were fed either a normal protein diet (NPD 20% casein) or a low protein diet (LPD; 8.7% casein) during pregnancy and 2 wk of lactation. In offspring at 32 wk of age, indirect calorimetry and dual energy x-ray absorptiometry (DEXA) were performed to assess metabolic activity and body composition. Insulin sensitivity was assessed using a euglycemic-hyperinsulinemic clamp. At 3 d of age, male and female LPD offspring were 23 and 27% smaller than controls, respectively. They remained significantly smaller throughout the experimental period (~10% smaller at 32 wk). Importantly, there was increased insulin sensitivity in LPD offspring (47% increase in males and 38% increase in females); pancreatic insulin content was normal. Body composition, O2 consumption, respiratory exchange ratio (RER), and locomotor activity were not different to controls. These findings suggest that in the absence of “catch-up” growth IUGR programs for improved insulin sensitivity.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

 This qualitative study explored adult men's experiences of father absence. Interviews with 21 men between the ages of 24 and 70 explored narratives of father absence and how the men perceived this influenced their life trajectory. Thematic analysis revealed that these men experienced a range of difficulties and challenges, including episodes of sadness and depression associated with loss and grief for the paternal relationship, self-esteem issues, feelings of anger and rejection, and difficulty forming trusting relationships particularly with other men. This study contributes to understanding mental health issues that can be associated with paternal absence for men.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Rabbits form a signifi cant component of the diet of the Wedge-tailed Eagle Aquila audax, particularly in temperate mainland Australia. The breeding-season diet of this eagle species was studied on Kangaroo Island, South Australia - a large island lacking rabbits. Wedge-tailed Eagles at three nest sites consumed mostly mammals (67% of prey individuals; 95% biomass; fi ve species), but also birds (33% of prey individuals; 5% biomass; fi ve species). Although roadkill is abundant on Kangaroo Island, further study is required to determine its relative infl uence in the diet of Wedge-tailed Eagles in this region.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Although many schools and educational systems, from elementary to tertiary level, state that they endorse anti-homophobic policies, pedagogies and programs, there appears to be an absence of education about, and affirmation of, bisexuality and minimal specific attention paid to bi-phobia. Bisexuality appears to be falling into the gap between the binary of heterosexuality and homosexuality that informs anti-homophobic policies, programs, and practices in schools initiatives such as health education, sexuality education, and student welfare. These erasures and exclusions leave bisexual students, family members and educators feeling silenced and invisibilized within school communities. Also absent is attention to intersectionality, or how indigeneity, gender, class, ethnicity, rurality and age interweave with bisexuality. Indeed, as much research has shown, erasure, exclusion, and the absence of intersectionality have been considered major factors in bisexual young people, family members and educators in school communities experiencing worse mental, emotional, sexual and social health than their homosexual or heterosexual counterparts.This book is the first of its kind, providing an international collection of empirical research, theory and critical analysis of existing educational resources relating to bisexuality in education. Each chapter addresses three significant issues in relation to bisexuality and schooling: erasure, exclusion, and the absence of intersectionality. From indigenous to rural schools, from tertiary campuses to elementary schools, from films to picture books as curriculum resources, from educational theory to the health and wellbeing of bisexual students, this book's contributors share their experiences, expertise and ongoing questions.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Social inclusion in Australian higher education was high on the agenda of the recent Rudd/Gillard Australian Government. This paper offers an assessment of that agenda, particularly the extent to which it worked in favour of under-represented groups. It argues that the Government’s widening and expansion policies and its equity and aspiration strategies lacked sociological imagination, projecting deficits onto individuals who refused to be taken in by its ambitions for higher education participation. The paper concludes that in the absence of a sociological imagination in government policy, the freedoms of disadvantaged groups continued to be curtailed: not just to choose futures in keeping with their goals but also the freedom to formulate choices.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Prolonged stress is known to impair reproduction. It has been proposed that reproduction will also be impaired when a severe acute stress occurs during a period of elevated plasma concentrations of oestradiol, such as during the follicular phase of the oestrous cycle. In this experiment, we hypothesised that repeated acute and sustained elevation of cortisol would suppress the secretion of LH in ovariectomised pigs and that these effects would be enhanced in the presence of oestradiol negative feedback. Cortisol (or vehicle) was administered 12 hourly to ovariectomised pigs (n=6/treatment) for 8 days in the absence of oestradiol treatment and for a further 8 days during treatment with oestradiol. Vehicle was administered to 'control' pigs, 10 or 20 mg cortisol was administered i.v. to pigs to produce 'repeated acute' elevation of cortisol and 250 mg cortisol was administered i.m. to pigs to give a 'sustained' elevation of cortisol. Both before and during treatment with oestradiol, plasma concentrations of LH were monitored on the day before treatment, on the 4th and 8th days of treatment and following an i.v. injection of GnRH at the end of the 8th day of treatment. The repeated acute elevation of cortisol did not impair any parameters of LH secretion (i.e. mean plasma concentrations of LH, pulse amplitude or frequency, pre-LH pulse nadir or the LH response to GnRH) in the absence or in the presence of oestradiol. In contrast, when the elevation of cortisol was sustained, the mean plasma concentrations of LH and the pre-LH pulse nadir were significantly (P<0.05) lower on the 8th day of treatment than on the day before treatment and on the 4th day of treatment. Nevertheless, no other parameters of LH secretion were affected and these effects only occurred in the absence (not in the presence) of oestradiol. In conclusion, cortisol needed to be elevated for more than 4 days to impair the secretion of LH, and oestradiol did not enhance the impact of cortisol on LH secretion in ovariectomised pigs.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Background
Rice is the primary source of food for billions of people in developing countries, yet the commonly consumed polished grain contains insufficient levels of the key micronutrients iron (Fe), zinc (Zn) and Vitamin A to meet daily dietary requirements. Experts estimate that a rice-based diet should contain 14.5 µg g−1 Fe in endosperm, the main constituent of polished grain, but breeding programs have failed to achieve even half of that value. Transgenic efforts to increase the Fe concentration of rice endosperm include expression of ferritin genes, nicotianamine synthase genes (NAS) or ferritin in conjunction with NAS genes, with results ranging from two-fold increases via single-gene approaches to six-fold increases via multi-gene approaches, yet no approach has reported 14.5 µg g−1 Fe in endosperm.

Methodology/Principal Findings
Three populations of rice were generated to constitutively overexpress OsNAS1, OsNAS2 or OsNAS3, respectively. Nicotianamine, Fe and Zn concentrations were significantly increased in unpolished grain of all three of the overexpression populations, relative to controls, with the highest concentrations in the OsNAS2 and OsNAS3 overexpression populations. Selected lines from each population had at least 10 µg g−1 Fe in polished grain and two OsNAS2 overexpression lines had 14 and 19 µg g−1 Fe in polished grain, representing up to four-fold increases in Fe concentration. Two-fold increases of Zn concentration were also observed in the OsNAS2 population. Synchrotron X-ray fluorescence spectroscopy demonstrated that OsNAS2 overexpression leads to significant enrichment of Fe and Zn in phosphorus-free regions of rice endosperm.

Conclusions
The OsNAS genes, particularly OsNAS2, show enormous potential for Fe and Zn biofortification of rice endosperm. The results demonstrate that rice cultivars overexpressing single rice OsNAS genes could provide a sustainable and genetically simple solution to Fe and Zn deficiency disorders affecting billions of people throughout the world.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This chapter introduces and problematizes the three impediments to sexual diversity and bisexuality in education, namely, erasure, exclusion by inclusion into gay and lesbian categories, and the absence of intersectionality (wherein other facets of identity and experience that interweave with sexuality are not taken into account, such as class, gender, Indigeneity/Aboriginality, ethnicity, geographical location, and religion). It introduces each chapter as well as reflecting on where further research is needed.