Diss. (sammanfattning) Stockholm : Karolinska institutet, 2005. / Härtill 4 uppsatser.

Thesis (M.S.)--University of Michigan, 1994.

Thesis (M.S.)--University of Michigan, 1994.

Thesis (M.S.)--Brigham Young University. Dept. of Physiology and Developmental Biology, 2007. / Includes bibliographical references.

Voltage-gated Cav2.1 (P/Q-type) and Cav2.2 (N-type) channels are two closely related calcium channels that play indispensable roles in signal transduction pathways by regulating neurotransmitter release. Despite having highly conserved amino acid sequences, they are differentially modulated by calmodulin, which mediate two important feedback mechanisms known as Ca2+-dependent inactivation (CDI) and Ca2+-dependent facilitation (CDF). These dual regulatory mechanisms contribute to synaptic plasticity, but only CDI is observed in Cav2.2 channel, while both CDI and CDF are present in Cav2.1 channel. Previously, it was hypothesized that the lack of CDF in Cav2.2 channel is due to the pre-IQ-IQ domain of the channel’s lower binding affinity for calmodulin compared to that of Cav2.1 channel. Now that the EF-hand domain of calcium channels is identified as one of the two minimally required molecular determinants that are responsible for supporting CDF in Cav2.1 channel and preventing CDF in Cav2.2 channel, it was necessary to determine the role of EF-hand domain in calmodulin binding of Cav2.1 and Cav2.2 channels. Using pull-down binding assays, this study finds that the EF-hand domain enhances calmodulin binding to the proximal C-terminal domain of Cav2.2 channel, which suggests that the lack of CDF in Cav2.2 does not result from the channel’s weak interaction with CaM, but from the EF-pre-IQ-IQ domain of the channel’s inability to allow calmodulin from fully exerting its effects.

Neste trabalho investigamos pela primeira vez flutuações dependentes de spin em correntes eletrônicas polarizadas através de estruturas magnéticas. Nosso sistema físico consiste de uma heteroestrutura com tunelamento ressonante formada por um poço ou \"ponto\" quântico contendo Mn, confinado entre duas barreiras de potencial. Usamos um modelo semiclássico baseado em equações de taxa para calcular as ocupações dos estados ressonantes up e down. Estas equações são derivadas de uma equação mestra que descreve a probabilidade de ocupação dos estados de spin em um dado tempo. Funções correlação corrente-corrente são expressas em termos das funções correlação hop-hop (associadas à transições entre os níveis ressonantes up e down) e o shot noise dependente de spin é determinado em termos da matriz variância do sistema, também derivada da equação mestra. Quando consideramos um feixe polarizado e tempos distintos (&#964 &#8593 &#8595 &#8800 &#964 &#8595 &#8593), podemos obter ambas \"correlações positivas\" (&#8249 &#916 &#8593 &#916 &#8595 &#8250 &#8805 0) e/ou \"negativas\" (&#8249 &#916 &#8593 &#916 &#8595 &#8250 &#8804 0) no nosso modelo. A generalização e reinterpretação do modelo de ilhas nos possibilitou (i) investigar flutuações dependentes de spin em correntes polarizadas; (ii) observar aumento e atenuação do shot noise; (iii) verificar que processos de \"spin-flip\" com (&#964 &#8593 &#8595 &#8800 &#964 &#8595 &#8593) são relevantes na atenuação do shot noise e (iv) verificar que o ruído contém informações sobre o processo de \"spin-flip\" / In this work we investigate for the first time spin-dependent fluctuations in spin-polarized electronic currents through magnetic structures. Our physical model consists of a resonant-tunneling heterostructure formed by a Mn-based quantum well or \"point\", confined between a double-barrier potential. We used a semiclassical model based on rate equations to calculate the occupations of the spin-up and spindown resonant states. These equations are derived from a master equation describing the probability of occupation of the spin states at a given time. Current-current correlation functions are expressed in terms of hop-hop correlation functions (for hops between islands representing the up and down states) and the spin-dependent shoi noise is determined in terms of the variance matrix of the system; also derived from the master equation. When we consider a polarized beam and distinctive times (&#964 &#8593 &#8595 &#8800 &#964 &#8595 &#8593), we can obtain both \"positive correlations\" (&#8249 &#916 &#8593 &#916 &#8595 &#8250 &#8805 0) and \"negative correlations\" (&#8249 &#916 &#8593 &#916 &#8595 &#8250 &#8804 0) in our model. The generalization and reinterpretation of the island model allowed us (i) to investigate spin-dependent fluctuations in spinpolarized electronic currents; (ii) to observe enhancement and suppression of shot noise; (iii) to verify that spin-flip processes with (&#964 &#8593 &#8595 &#8800 &#964 &#8595 &#8593) are relevant to shotnoise suppression and (iv) to verify that noise contains information about spin-flip processes

Background. Type 2 diabetes is the fifth-leading cause of death in Latinos in the United States. Diabetes is a commonly occurring health condition in older adults, leading to complications that can severely impact quality of life and hasten death. The burden of diabetes is considerable in the older adult population; almost four-fifths of adults with diabetes are older than 59 years. Diabetes mortality can be reduced or delayed with effective management of the illness. Older minority adults are more likely to have higher rates of adult-onset diabetes than non-Hispanic Whites, yet few studies have examined the diabetes self-management practices of this group. These issues are particularly important to investigate in older Dominican adults in Washington Heights/Inwood, New York City, because this group has unique cultural beliefs and practices, is rapidly increasing in population, and has a variety of unmet health-related needs. This study explored specific barriers encountered (cultural and structural) and the extent to which external factors are associated with self-management practices among older Dominican community residents living in mainland US with type 2 diabetes. After 20 years of health disparities research and intervention older adults continue to have problems accessing health care due to structural and socio-cultural barriers. Methods. This investigation utilized qualitative in-depth interviews to examine the cultural and structural barriers to health care and self-management practices existing in this group. Results. Thirty Dominicans 55 years and older were recruited through a community-based senior resource center from the mainland US. Self-management practices for type 2 diabetes vary and are represented by commonly known factors, including: 1) diet modifications; 2) glucose monitoring; 3) medication adherence; 4) exercise, and 5) diabetes classes. Findings from this study illustrate that male and female participants have mixed self-management practices that assist them in managing their diabetes. In addition, participants are interested in “learning” how to manage their diabetes through their participation in classes and diabetes-related workshops. Home remedies (remedies caseros) for type 2 diabetes were identified in this study. Conclusions. Programs and services that promote healthy self-management practices of older Latino adults need to include a focus on the unique cultural beliefs and behaviors of the individual as well as the broader situational context that impacts their diabetes self-management. Such information is invaluable for researchers and health practitioners interested in diabetes self-management practices of older minority adults.

No description available.

Diss. (sammanfattning) Linköping : Univ. / Härtill 6 uppsatser.

Background. With increasing personal affluence and changes in lifestyle, there is rising prevalence of type 2 diabetes mellitus in Hong Kong. Approximately 60% of diabetic subjects in Hong Kong are asymptomatic and previously undiagnosed. Since diabetes carries significant mortality and morbidity risk, it is important to diagnose these subjects early for intervention. There are many known factors associated with development of type 2 diabetes. Some are remediable such as obesity, dyslipidaemia, hypertension, while some are non-remediable such as age and past history of gestational diabetes. Identifying high-risk subjects will increase the yield and cost-effectiveness of screening program for diabetes and related risk factors and provide useful epidemiological information on the natural history of these diseases. / Methods. I used data from several cross-sectional and prospective studies of which I was the principal investigator or one of the co-investigators to test these hypotheses. The studies include mainly the following: (1) A public utility company workforce survey on cardiovascular risk factors in 1990 (n=1513). (2) Chinese subjects with risk factors for diabetes who underwent 75 gram oral glucose tolerance test (OGTT) screening at the Prince of Wales Hospital (PWH) between 1988 and 1995 (n=3718). (3) The 'United Christian Nethersole Community Health Service' (UCNCHS) primary health screening program database in 1997 (n=17764). / Objectives & hypothesis. I aimed to study the various factors associated with the development of type 2 diabetes in Hong Kong Chinese. With this information, I can design a screening method to early identify those subjects who are at high-risk for diabetes. I hypothesize the following: (1) Many risk factors for diabetes in Caucasians are also applicable to Hong Kong Chinese. (2) The presence of multiple factors increases the risk of diabetes in a linear fashion. (3) Chinese subjects are at risk of developing diabetes at a lower threshold of obesity, which is one of the most important risk factors for type 2 diabetes. / Results. Based on a cohort of 1513 asymptomatic subjects from a workforce survey, those in the top quartile of body mass index (BMI), as compared to those in the lowest quartile, had a 4 to 10-fold increased risk of diabetes and a 2.5 to 5-fold increased risk of impaired glucose tolerance (IGT) for men and women. (Abstract shortened by UMI.) / Ko Tin Choi. / "May 2005." / Source: Dissertation Abstracts International, Volume: 67-01, Section: B, page: 0173. / Thesis (M.D.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (p. 264-283). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / School code: 1307.