1,656 research outputs found

    Vimentin downregulation is an inherent feature of murine erythropoiesis and occurs independently of lineage

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    In mammalian erythropoiesis, the mature cells of the primitive lineage remain nucleated while those of the definitive lineage are anuclear. One of the molecular and structural changes that precedes enucleation in cells of the definitive lineage is the cessation in the expression of the gene for the intermediate filament (IF) protein vimentin and the removal of all vimentin filaments from the cytoplasm. We show here that in immature primitive cells vimentin is synthesized and forms a cytoplasmic network of IFs. As differentiation proceeds in vivo, vimentin gene expression is downregulated in these cells; this is accompanied by the loss of vimentin filaments from the cytoplasm. This loss temporally coincides with the nucleus becoming freely mobile within the cytoplasm, suggesting that, while IF removal is not directly linked to the physical process of enucleation, it may be a prerequisite for the initiation of nuclear mobility in both lineages. These changes are also observed in early primitive cells cultured in vitro, suggesting that they constitute an intrinsic part of the murine erythroid differentiation program independent of lineage and hematopoietic microenvironment

    Racial Battle Fatigue and Graduate Student Roles: The Experiences of Black/African American, Biracial Black, and Multiracial Black Identified Students

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    Black students continue to endure racialized experiences in their pursuit of higher learning. Studentsā€™ educational experiences, especially at historically White institutions, are plagued by incidents of racial microaggressions and racial stress, which in turn result in studentsā€™ experiences of racial battle fatigue (RBF; e.g., Smith, Hung, & Franklin, 2011), which is the everyday psychophysiological effects associated with racial/ethnic minoritiesā€™ experiences as they fight racial microaggressions (e.g., Smith, Allen, & Danley, 2007). RBF has been linked to decreased academic performance and poor physical and mental health outcomes (e.g., Franklin-Jackson & Carter, 2007; Hotchkins, 2016; Smith et al., 2007) among Blacks, especially men (Smith et al., 2011). The aims of this dissertation were to use a quantitative descriptive, non-experimental design and collect data with Black graduate students (BGSs) in clinical and counseling programs to (a) identify their RBF experiences as students in class, advisees, and supervisees and (b) identify differences in RBF experiences across key demographic characteristics. Self-report data were collected via online survey from 69 gender diverse, clinical and counseling graduate students, enrolled at colleges and universities across the United States, and who self-identified as Black/African American, Biracial Black, or Multiracial Black. One-way, within-subjects analysis of variance results showed that (a) BGSsā€™ psychological, physiological, and behavioral stress responses in their role as students in class were most impacted by racial microaggressions as compared to their roles as advisees and supervisees and (b) BGSsā€™ overall RBF in their role as students in class was most impacted by racial microaggressions as compared to their roles as advisees and supervisees; and (c) experiences of RBF for BGSs in clinical and counseling training programs varied by key demographic variables and roles. Findings suggest that there is a relationship between racial microaggressions and stress responses for gender diverse, BGSs in clinical and counseling programs and that this relationship varies, in part, by BGSsā€™ roles as students in class, advisees, and supervisees. Results suggest that role/context matter in the experiences of RBF for BGSs in clinical and counseling programs. The RBF framework has some utility for this student population. Study implications and future research directions are discussed

    Exercise behaviour change in a young adult population: a qualitative and quantitative analysis

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    Participation in regular physical activity among young adults (16-24 years) is suboptimal. Research has attempted to understand what determines exercise behaviour and how interventions can assist individuals in adopting and adhering to exercise. This thesis consists of a literature review, and three separate studies. In the literature review, inactivity is defined, and the current physical activity patterns of industrialised society are discussed. Models of behaviour change that enhance our understanding of the adoption and adherence process in physical activity are examined. In particular, the transtheoretical model of behaviour change [TTM] has been selected for further study. This model is unique to the study of exercise behaviour because it provides researchers with an opportunity to identify and work with an inactive population, and permits the tailoring of physical activity interventions to make them more suitable for sedentary individuals. Initially, the TTM and its core constructs are explained, followed by a critique of the model. A review of empirical research in physical activity that has been based on the TTM is included. Over fifty key studies were identified; the limitations and strengths of these studies are explored. Finally, the discussions will summarise what has been learned to date about the application of the TTM to the understanding of behaviour modification in physical activity. In study one, constructs from the transtheoretical model of behaviour change were chosen to help understand the process of exercise behaviour change of a student population. A total of 2943 respondents completed a baseline questionnaire and 1058 completed a follow-up 7 months later. A 5-item stage of change and a 40-item process of change questionnaire was used. There were significant differences in physical activity patterns from baseline to follow-up. There were also significant differences in process use across the stages. The process data was factor analysed to refine it further. A three-factor model revealed different motivational clusters underlying actual stage of behaviour change. Recommendations for intervention design suggest that adopting a positive behaviour should be treated differently to ceasing a negative behaviour. In study two, a pre-post randomised control design was used to investigate the effectiveness of a self-instructional intervention for helping a sedentary undergraduate population to become more active. The intervention was based on the transtheoretical model of behaviour change. Significantly more of the experimental group in comparison to the control group improved their stage of change from baseline. Self-efficacy and not decisional balance was found to be useful predictor of stage improvement. Discriminant analyses revealed that discrimination between stage improvement versus non-improvement was possible using the processes of change data. For stage improvers, the processes self-reevaluation and self-liberation were most frequently used, while social liberation was used significantly more by the experimental than the control group

    Control of erythroid differentiation: asynchronous expression of the anion transporter and the peripheral components of the membrane skeleton in AEV- and S13-transformed cells

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    Chicken erythroblasts transformed with avian erythroblastosis virus or S13 virus provide suitable model systems with which to analyze the maturation of immature erythroblasts into erythrocytes. The transformed cells are blocked in differentiation at around the colony-forming unit- erythroid stage of development but can be induced to differentiate in vitro. Analysis of the expression and assembly of components of the membrane skeleton indicates that these cells simultaneously synthesize alpha-spectrin, beta-spectrin, ankyrin, and protein 4.1 at levels that are comparable to those of mature erythroblasts. However, they do not express any detectable amounts of anion transporter. The peripheral membrane skeleton components assemble transiently and are subsequently rapidly catabolized, resulting in 20-40-fold lower steady-state levels than are found in maturing erythrocytes. Upon spontaneous or chemically induced terminal differentiation of these cells expression of the anion transporter is initiated with a concommitant increase in the steady- state levels of the peripheral membrane-skeletal components. These results suggest that during erythropoiesis, expression of the peripheral components of the membrane skeleton is initiated earlier than that of the anion transporter. Furthermore, they point a key role for the anion transporter in conferring long-term stability to the assembled erythroid membrane skeleton during terminal differentiation

    The transgressive that: making the world uncanny.

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    In this article, we examine how the demonstrative that may be used to notice an event in the world in such a way as to suggest it has highly unusual or transgressive properties and in so doing invite others to align with that implicit claim. Drawing on Freud's notion of the uncanny, we examine instances of the transgressive that in circumstances in which participants at least entertain the possibility that they are experiencing anomalous or paranormal objects and entities. The analysis outlines the basic features of the transgressive that and examines how it may be the vehicle for a range of delicate interpersonal activities. Throughout the article, we try to show the broader relevance of the analytic argument by reference to data from more mundane interactional settings and to other forms of discourse, including fiction, commentary and interview narrative

    Resources for Workplace Diversity: An Annotated Practitioner Guide to Information

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    [Excerpt] We are pleased to offer this updated edition of Resources for Workplace Diversity: An Annotated Practitioner Guide to Information, a unique offering of The Workplace Diversity Network. Our goal is to assemble a selected, annotated list of compelling and useful resources available to help diversity practitioners create organizations that are diverse and productive. As a working group, we agreed that useful resources would include newly published books as well as historic, seminal works that provide insight and illumination irrelevant of their age. In the updated edition, weā€™ve expanded existing sections, added new ones and referenced online access where possible. Designed with practitioner needs in mind, Resources for Workplace Diversity is meant to be an evolving document, one that will grow according to the needs and recommendations of its users. To capture the advantage of networking, we invite you to suggest additional resources that you have found to be valuable

    Health Care Professionalsā€™ Knowledge and Practice of Physical Activity Promotion for Cancer Survivors in Ireland

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    Purpose: With advancements in cancer screening and treatment, cancer mortality rates continue to decline for most major cancer types globally. This translates into a growing cohort of cancer survivors worldwide, estimated to be over 30 million surviving at least five years post diagnosis. However, this success has also brought to the recognition that cancer survivors have significantly elevated risk of premature death and serious morbidity due to cancer recurrence, secondary cancers, and chronic health conditions such as cardiovascular disease and obesity. Cancer survivors also experience fatigue, depression, and pain, resulting in reduced quality of life. Rationale: Nutrition and physical activity are one of the cornerstones for cancer prevention and control, and are among the few modifiable behaviours for preventing chronic health conditions and improving quality of life. Poor nutritional intake and sedentary behaviour can exacerbate morbidities in cancer survivors, while healthy dietary patterns and being physically active can serve a protective function. Health care professionals play critical roles in reinforcing the importance of healthy lifestyles for long-term health. It is imperative to assess health care professionalsā€™ knowledge and practice of providing lifestyle support to cancer survivors. Research is also needed to understand the targeted nutritional needs in cancer survivors and the mediators of lifestyle interventions to develop personalised lifestyle prescription for the growing population of cancer survivors. Objectives: We aim to discuss the targeted nutritional needs in cancer survivors, the effect and underlying mechanisms of clinical- and community-based lifestyle interventions on survivorsā€™ physical and psychosocial functioning and quality of life, and cost-effective strategies to integrate personalized lifestyle prescription into cancer care or community settings. Summary: Four short papers will be presented on diet quality and nutritional intake in cancer survivors, the effect and underlying mechanisms of lifestyle interventions on survivorsā€™ physical and psychosocial functioning and quality of life, and health care professionalsā€™ knowledge and practice of physical activity promotion for cancer survivors. This will be followed by facilitated discussions on how to address specific nutrition and physical activity needs in cancer survivors through cost-effective interventions

    Recognition of DNA Termini by the C-Terminal Region of the Ku80 and the DNA-Dependent Protein Kinase Catalytic Subunit

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    DNA double strand breaks (DSBs) can be generated by endogenous cellular processes or exogenous agents in mammalian cells. These breaks are highly variable with respect to DNA sequence and structure and all are recognized in some context by the DNA-dependent protein kinase (DNA-PK). DNA-PK is a critical component necessary for the recognition and repair of DSBs via non-homologous end joining (NHEJ). Previously studies have shown that DNA-PK responds differentially to variations in DSB structure, but how DNA-PK senses differences in DNA substrate sequence and structure is unknown. Here we explore the enzymatic mechanisms by which DNA-PK is activated by various DNA substrates and provide evidence that the DNA-PK is differentially activated by DNA structural variations as a function of the C-terminal region of Ku80. Discrimination based on terminal DNA sequence variations, on the other hand, is independent of the Ku80 C-terminal interactions and likely results exclusively from DNA-dependent protein kinase catalytic subunit interactions with the DNA. We also show that sequence differences in DNA termini can drastically influence DNA repair through altered DNA-PK activation. These results indicate that even subtle differences in DNA substrates influence DNA-PK activation and ultimately the efficiency of DSB repair

    Identifying High and Low Walkable Neighbourhoods Using Multi-disciplinary Walkability Criteria

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    Neighbourhood features contributing to the walkability (pedestrian friendliness) of a neighbourhood are diverse and depend on both its physical and social attributes. Earlier work in the Cleaner, Greener, Leaner (CGL) Study identified differences in opinion between professional stakeholder groups (planners, designers, engineers, public representatives, and public health and advocacy professionals) on what constitutes a walkable environment [1]. This diversity has implications for neighbourhood design and planning policy. The findings of a multi-disciplinary focus group study were used to generate a list of walkability criteria to select areas for a population study. In this study twenty areas were shortlisted and grouped under four categories: high walkable deprived, high walkable not deprived, low walkable deprived and low walkable not deprived. This paper presents the process undertaken to identify the study sites. International walkability research has favoured macro-scale objective geographic information systems (GIS) information to identify study areas [2]. While these macro scale attributes are important for walkability, alone they were considered insufficient for site selection by the CGL team as street characteristics were not considered and the attributes had a bias towards transportation walking. Also, indications from the focus group participants were that walkability is perceptual and therefore some resulting criteria were subjective, for example ā€˜a pleasant atmosphere contextual to area characteristicsā€™ and therefore difficult to measure objectively. The CGL site selection process presented a number of challenges including limitations with available GIS information, unrepresentative neighbourhood boundaries on GIS datasets, and only one deprived neighbourhood identified as high walkable by the focus group participants. An investigation of the role of high and low walkable environments on residentā€™s behaviours and health can be used to inform future planning, transport, public health and neighbourhood design policies
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