84 research outputs found
Light and Submerged Macrophyte Communities in Chesapeake Bay: A Scientific Summary
The initial focus of submerged aquatic vegetation (SAV) research in the U.S. Environmental Protection Agency (EPA), Chesapeake Bay Program (CBP) was evaluation of the structural and functional ecology of these communities. In the upper Bay, Myriophyllum spicatum and Potamogeton perfoliatus are the dominant species; the dominant species in the lower Bay are Zostera marina and Ruppia maritima. Studies centered on various aspects of productivity (both primary and secondary), trophic structure, and resource utilization by both ecologically and economically important species. Much of the initial research was descriptively oriented because of a general lack of information on Chesapeake Bay submerged plant communities. These investigations created the data base necessary for the development of ecologically realistic simulation models of the ecosystem. Following these initial studies, the research programs in both Maryland and Virginia evolved toward more· detailed analyses of specific factors ~hat potentially limit or control plant growth and productivity. Previous results indicated certain environmental parameters and biological processes that possibly limited and controlled SAV distribution and abundance. Specifically, these included light, nutrients, herbicides and fouling (epibiotic growth). Laboratory and field studies were devoted in the later phases of the CBP-SAV program toward investigating these interactions. This work is among the first studies in North America to investigate light quality as a major environmental factor affecting the survival of sea grasses.https://scholarworks.wm.edu/vimsbooks/1098/thumbnail.jp
The Functional ecology of submerged aquatic vegetation in the lower Chesapeake Bay
The research program, The Functional Ecology of Submerged Aquatic Vegetation in the Lower Chesapeake Bay (EPA/CBP Grant No. R805974), is an integrative effort composed of seven principal investigators. The research team has worked since July 1978 at one study site, the Vaucluse Shores area, to develop and institute a coherent research program on SAV ecological relationships.
The principal studies have focused on plant productivity, metabolism and nutrient cycling, the role of resident consumers in SAV community dynamics, the role of migratory species and efforts to develop a realistic, ecosystem simulation model of SAV communities.
The preliminary results of the first years study in these research areas are contained in the following report. Many interpretations remain preliminary at this time. We welcome comments and criticisms and in particular ideas concerning data interpretation.
Questions concerning specific aspects of the various sections should be addressed to the following:
1. Productivity, Metabolism and Nutrient Cycling; R. L. Wetzel
2. Resident Consumers; R. J. Orth
3. Migratory Consumers; J. V. Merriner
4. Ecosystem Modelling; R. L. Wetze
Growth or decline in the Church of England during the decade of Evangelism: did the Churchmanship of the Bishop matter?
The Decade of Evangelism occupied the attention of the Church of England throughout the 1990s. The present study employs the statistics routinely published by the Church of England in order to assess two matters: the extent to which these statistics suggest that the 43 individual dioceses finished the decade in a stronger or weaker position than they had entered it and the extent to which, according to these statistics, the performance of dioceses led by bishops shaped in the Evangelical tradition differed from the performance of dioceses led by bishops shaped in the Catholic tradition. The data demonstrated that the majority of dioceses were performing less effectively at the end of the decade than at the beginning, in terms of a range of membership statistics, and that the rate of decline varied considerably from one diocese to another. The only exception to the trend was provided by the diocese of London, which experienced some growth. The data also demonstrated that little depended on the churchmanship of the diocesan bishop in shaping diocesan outcomes on the performance indicators employed in the study
Discussing atypical sexual harassment as a controversial issue in bystander programmes: One UK campus study
This research emanates from an anti-sexual violence bystander programme delivered at an English university. Fifteen students were identified through purposive and convenience sampling to take part in focus groups. Discussions emerged regarding atypical sexual harassment. There is a gap in the literature exploring sexual harassment outside of the male perpetrator and female victim narrative which this paper contributes to. This paper considers four conversational themes: ‘unwanted touching: women to men’, ‘sexual banter: women to men’, ‘sexual stereotypes: women and men’, and ‘developing stronger ethical subjectivity’. This paper recognises most sexual harassment occurs from men to women, and acknowledges criticism of focussing otherwise when resources are limited, noting this risks obscuring the enduring power differentials between the sexes. It contends that exploring a controversial issue, such as male experience of sexual harassment, might help bystander programmes by developing ethical subjectivity in undergraduate students. Exploring sexual behaviour as a spectrum may lead to counter hegemonic discourses to emerge
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‘I went back to being myself’ : acceptability of a culturally adapted task-shifted cognitive-behavioural therapy (CBT) treatment for depression (Ziphamandla) for South African HIV care settings
CITATION: Everitt-Penhale, B. et al. 2019. ‘I went back to being myself’: acceptability of a culturally adapted task-shifted cognitive-behavioural therapy (CBT) treatment for depression (Ziphamandla) for South African HIV care settings. Psychology, Health & Medicine, 24(6):680-690. doi:10.1080/13548506.2019.1566624The original publication is available at https://www.tandfonline.com/toc/cphm20/currentENGLISH ABSTRACT: There is a need for a culturally adapted, evidence-based, psychotherapy treatment that is effective, acceptable, and feasible for integration into primary care in South Africa. This qualitative study used exit interviews to examine participants’ experiences of an adapted cognitive-behavioural therapy treatment for adherence and depression, task-shifted and delivered by nurses in two peri-urban HIV clinics near Cape Town. Nine semi-structured exit interviews were conducted with isiXhosa-speaking females and analysed using thematic analysis. Overall, participants responded positively to the treatment, viewing it as acceptable and beneficial and as a catalyst to returning to normalcy. Results indicated that participants viewed the treatment as being effective in ameliorating their depressive symptoms and improving their adherence to ART . Additional benefits described included improvements in subjective wellbeing and social and occupational functioning. Several began or resumed employment, an important behavioural indicator of the treatment’s capacity to facilitate positive change and cost saving. Recommendations to improve the treatment included using video material and educating others about depression. These findings have positive implications regarding the acceptability and cultural applicability of the treatment for use in South Africa.https://www.tandfonline.com/doi/full/10.1080/13548506.2019.1566624Publisher’s versio
Low oxygen affects photophysiology and the level of expression of two-carbon metabolism genes in the seagrass <i>Zostera muelleri</i>
© 2017, Springer Science+Business Media B.V. Seagrasses are a diverse group of angiosperms that evolved to live in shallow coastal waters, an environment regularly subjected to changes in oxygen, carbon dioxide and irradiance. Zostera muelleri is the dominant species in south-eastern Australia, and is critical for healthy coastal ecosystems. Despite its ecological importance, little is known about the pathways of carbon fixation in Z. muelleri and their regulation in response to environmental changes. In this study, the response of Z. muelleri exposed to control and very low oxygen conditions was investigated by using (i) oxygen microsensors combined with a custom-made flow chamber to measure changes in photosynthesis and respiration, and (ii) reverse transcription quantitative real-time PCR to measure changes in expression levels of key genes involved in C4 metabolism. We found that very low levels of oxygen (i) altered the photophysiology of Z. muelleri, a characteristic of C3 mechanism of carbon assimilation, and (ii) decreased the expression levels of phosphoenolpyruvate carboxylase and carbonic anhydrase. These molecular-physiological results suggest that regulation of the photophysiology of Z. muelleri might involve a close integration between the C3 and C4, or other CO2 concentrating mechanisms metabolic pathways. Overall, this study highlights that the photophysiological response of Z. muelleri to changing oxygen in water is capable of rapid acclimation and the dynamic modulation of pathways should be considered when assessing seagrass primary production
Impact of the TCR Signal on Regulatory T Cell Homeostasis, Function, and Trafficking
Signaling through the T cell antigen receptor (TCR) is important for the homeostasis of naïve and memory CD4+ T cells. The significance of TCR signaling in regulatory T (Treg) cells has not been systematically addressed. Using an Ox40-cre allele that is prominently expressed in Treg cells, and a conditional null allele of the gene encoding p56Lck, we have examined the importance of TCR signaling in Treg cells. Inactivation of p56Lck resulted in abnormal Treg homeostasis characterized by impaired turnover, preferential redistribution to the lymph nodes, loss of suppressive function, and striking changes in gene expression. Abnormal Treg cell homeostasis and function did not reflect the involvement of p56Lck in CD4 function because these effects were not observed when CD4 expression was inactivated by Ox40-cre.The results make clear multiple aspects of Treg cell homeostasis and phenotype that are dependent on a sustained capacity to signal through the TCR
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