916 resultados para Method development and research


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The present publication is the final outcome of the "Syndrome Pre-SynthesisProject" (SPSP), a preparatory project initiated in 2001 to pave the way for the NCCR North-South. The SPSP applied a transdisciplinary approach to identify research partnerships for development in 8 regions of the world. The primary aim of the present publication is to present an initial synthesis of core problems in each region, of the status and focus of related research, and of corresponding new research needs. Based on the results of this participatory process, the NCCR North-South programme has followed up on the outcomes of the regional syntheses by identifying future research aims along the general lines determined in the workshops.

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Current therapies to treat inflammatory bowel diseases have limited efficacy, significant side effects, and often wane over time. Little is known about the cellular and molecular mechanisms operative in the process of mucosal healing from colitis. To study such events, we developed a new model of reversible colitis in which adoptive transfer of CD4(+)CD45RB(hi) T cells into Helicobacter typhlonius-colonized lymphopenic mice resulted in a rapid onset of colonic inflammation that was reversible through depletion of colitogenic T cells. Remission was associated with an improved clinical and histopathological score, reduced immune cell infiltration to the intestinal mucosa, altered intestinal gene expression profiles, regeneration of the colonic mucus layer, and the restoration of epithelial barrier integrity. Notably, colitogenic T cells were not only critical for induction of colitis but also for maintenance of disease. Depletion of colitogenic T cells resulted in a rapid drop in tumor necrosis factor α (TNFα) levels associated with reduced infiltration of inflammatory immune cells to sites of inflammation. Although neutralization of TNFα prevented the onset of colitis, anti-TNFα treatment of mice with established disease failed to resolve colonic inflammation. Collectively, this new model of reversible colitis provides an important research tool to study the dynamics of mucosal healing in chronic intestinal remitting-relapsing disorders.Mucosal Immunology advance online publication 16 September 2015; doi:10.1038/mi.2015.93.

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Volunteers are still the most important resource for amateur football clubs. However, stable voluntary engagement can no longer be granted. This difficulty is confirmed by existing research across various European countries. From a club management point of view, a detailed understanding of how to attract volunteers and retain them is becoming a high priority. The purpose of this study is (1) to analyse the influence of individual characteristics and corresponding organisational conditions on volunteering and (2) to examine the decision-making processes in relation to implement effective strategies for recruiting volunteers. To answer these questions, the current state of research is summarised and then a multi-level-framework is developed which is based on the structural-individualistic social theory. The individual and context factors for volunteering are estimated in different multi-level models based on a sample of n=1,434 sport club members from 36 sport clubs in Switzerland. Results indicate that volunteering is not just an outcome of individual characteristics such as lower workloads, higher income, children belonging to the sport club, longer club membership, or a strong commitment to the club. It is also influenced by club-specific structural conditions. Concerning decision-making processes an in-depth analysis of recruitment practices for volunteers was conducted in selected clubs (case study design). based on the garbage can model. The results show that systematically designed decision-making processes with a clear regulation of responsibilities seem to solve personnel problems more purposefully and more quickly. Based on the findings some recommendations for volunteer management in football clubs are worked out.

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Tracing the history of individual cells during embryonic morphogenesis in a structure as complex as the cardiovascular system is one of the major challenges of developmental biology. It involves determining the relationships between the various lineages of cells forming an organ at different stages, describing the topological rearrangements tissues undergo during morphogenesis, and characterizing the interactions between cells in different structures. However, despite the great expectations raised in the field of regenerative medicine, only limited progress has been made in using regenerative therapy to repair the cardiovascular system. Recent research has highlighted the role of the epicardium during cardiac regeneration, but it is still unclear whether it is important for molecular signaling or acts as a source of progenitor cells during this process. Consequently, increasing knowledge about the origin, diversification and potential of epicardial cells during development and homeostasis and under pathological conditions is of fundamental importance both for basic research and for the development of effective cellular therapies. The aims of this article were to provide a general overview of the classical techniques used for tracing cell lineages, including their potential and limitations, and to describe novel techniques for studying the origin and differentiation of the epicardium and its role in cardiac regeneration.

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Seventeen polymorphic microsatellite markers were isolated and characterized in Arion vulgaris/lusitanicus, which belongs to the worst European slug pests with serious economic and ecological impact. These markers were tested on 23 individuals collected in a population in Switzerland. Numbers of alleles ranged from 2 to 14 per locus, observed and expected heterozygosities ranged from 0.174 to 0.87, and from 0.162 to 0.903, respectively. These loci were also successfully amplified and were polymorphic in the closely related species A. rufus and A. ater. These loci represent the first highly polymorphic nuclear markers described for A. vulgaris and pave the way for population genetics and molecular ecology research of the important Arion pest slugs.

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The need for wildlife health surveillance has become increasingly recognized. However, comprehensive programs which cover a wide spectrum of species, pathogens and geographic areas are still lacking in most European countries and practical examples of systems in place remain scarce. This article provides an overview of the organization of wildlife health surveillance in Switzerland, with a focus on the development, current strategies and the activities of the national program carried out by the Centre for Fish and Wildlife Health (FIWI), University of Bern. This documentation may stimulate on-going discussions on the design and development of national wildlife health surveillance programs in other countries. Investigations into wildlife health in Switzerland date back to the 1950s. The FIWI acts as a national competence center for wildlife diseases on mandate of the Swiss federal authorities. The mandate includes four main activities: disease diagnostics, research, consulting and teaching. In line with this, the FIWI has made continuous efforts to strengthen a national network of field partners and implemented strategies to facilitate long-term and metastudies.

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Australia is unique as a populated continent in that canine rabies is exotic, with only one likely incursion in 1867. This is despite the presence of a widespread free-ranging dog population, which includes the naturalized dingo, feral domestic dogs and dingo-dog cross-breeds. To Australia's immediate north, rabies has recently spread within the Indonesian archipelago, with outbreaks occurring in historically free islands to the east including Bali, Flores, Ambon and the Tanimbar Islands. Australia depends on strict quarantine protocols to prevent importation of a rabid animal, but the risk of illegal animal movements by fishing and recreational vessels circumventing quarantine remains. Predicting where rabies will enter Australia is important, but understanding dog population dynamics and interactions, including contact rates in and around human populations, is essential for rabies preparedness. The interactions among and between Australia's large populations of wild, free-roaming and restrained domestic dogs require quantification for rabies incursions to be detected and controlled. The imminent risk of rabies breaching Australian borders makes the development of disease spread models that will assist in the deployment of cost-effective surveillance, improve preventive strategies and guide disease management protocols vitally important. Here, we critically review Australia's preparedness for rabies, discuss prevailing assumptions and models, identify knowledge deficits in free-roaming dog ecology relating to rabies maintenance and speculate on the likely consequences of endemic rabies for Australia.

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Neospora caninum is considered one of the main causes of abortion in cattle, yet recent studies have also emphasised its relevance as an abortifacient in small ruminants. In order to gain deeper insight into the pathogenesis of ovine neosporosis, pregnant ewes were intravenously inoculated with 10(6) tachyzoites of the Nc-Spain7 isolate at days 40, 90 or 120 of gestation. Infection during the first term resulted in the death of all foetuses between days 19 and 21 post-infection, showing mainly necrotic lesions in foetal liver and the highest parasite DNA detection and burden in both placenta and foetal viscera. After infection at day 90, foetal death was also detected in all ewes, although later (34-48 days post-infection). In this group, lesions were mainly inflammatory. Foetal livers showed the lowest frequency of lesions, as well as the lowest parasite detection and burden. All ewes infected at day 120 delivered viable lambs, although 3 out of 9 showed weakness and recumbency. Neospora DNA was detected in all lambs but one, and parasite burden was similar to that observed in day 90 group. Lesions in this group showed more conspicuous infiltration of inflammatory cells and higher frequency in foetal brain and muscle when compared to both previous groups. These results highlight the crucial role that the stage of gestation plays on the course of ovine neosporosis, similar to that reported in bovine neosporosis, and open the doors to consider sheep as a valid model for exogenous transplacental transmission for ruminant neosporosis.

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This study adapted the current model of science undergraduate research experiences (URE's) and applied this novel modification to include community college students. Numerous researchers have examined the efficacy of URE's in improving undergraduate retention and graduation rates, as well as matriculation rates for graduate programs. However, none have detailed the experience for community college students, and few have employed qualitative methodologies to gather relevant descriptive data from URE participants. This study included perspectives elicited from both non-traditional student participants and the established laboratory community. The purpose of this study was to determine the effectiveness of the traditional model for a non-traditional student population. The research effort described here utilized a qualitative design and an explanatory case study methodology. Six non-traditional students from the Maine Community College System participated in this study. Student participants were placed in six academic research laboratories located throughout the state. Student participants were interviewed three times during their ten-week internship and asked to record their personal reflections in electronic format. Participants from the established research community were also interviewed. These included both faculty mentors and other student laboratory personnel. Ongoing comparative analysis of the textual data revealed that laboratory organizational structure and social climate significantly influence acculturation outcomes for non-traditional URE participants. Student participants experienced a range of acculturation outcomes from full integration to marginalization. URE acculturation outcomes influenced development of non-traditional students? professional and academic self-concepts. Positive changes in students? self-concepts resulted in greater commitment to individual professional goals and academic aspirations. The findings from this study suggest that traditional science URE models can be successfully adapted to meet the unique needs of a non-traditional student population – community college students. These interpretations may encourage post-secondary educators, administrators, and policy makers to consider expanded access and support for non-traditional students seeking science URE opportunities.

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Metasequoia glyptostroboides is a useful nearest living relative (NLR) of the Eocene fossil Metasequoia. Research on modern Metasequoia might give us some clues about its fossil counterpart. During this study the leaf anatomy of Metasequoia, Glyptostrobus, Sequoia and Taxodium was investigated with light microscopy and transmission electron microscopy. Metasequoia exhibits several characteristics of typical sciaphilic plants, such as slightly arched outer cell walls in the adaxial epidermal cells, strongly arched outer cell walls in the abaxial epidermal cells, mesophyll composed of spongy cells, chloroplasts with well-developed grana not only in mesophyll cells but in both the adaxial and abaxial epidermis. Based on comparison of leaf morphology and anatomy, we conclude that Metasequoia is best adapted to low light intensities, Sequoia and Taxodium are intermediate, and Glyptostrobus is adapted to higher light intensities. The effects of light intensity on mesophyll plastids of Metasequoia leaves were studied with trees grown under different light intensities. Metasequoia had the ability to synthesize chlorophyll under complete darkness and was stressed under high light. These characteristics would provide adaptive advantages for Metasequoia to adapt to low intensity, low angle, polar light at their Eocene high latitude paleoenvironments, particularly during the polar spring when light levels are exceedingly low. It provides evidence to explain why Metasequoia was the dominant tree species in Eocene high latitudes. The thesis is written as an article to be submitted to the American Journal of Botany.

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Symptoms has been shown to predict quality of life, treatment course and survival in solid tumor patients. Currently, no instrument exists that measures both cancer-related symptoms and the neurologic symptoms that are unique to persons with primary brain tumors (PBT). The aim of this study was to develop and validate an instrument to measure symptoms in patients who have PBT. A conceptual analysis of symptoms and symptom theories led to defining the symptoms experience as the perception of the frequency, intensity, distress, and meaning that occurs as symptoms are produced, perceived, and expressed. The M.D. Anderson Symptom Inventory (MDASI) measures both symptoms and how they interfere with daily functioning in patients with cancer, which is similar to the situational meaning defined in the analysis. A list of symptoms pertinent to the PBT population was added to the core MDASI and reviewed by a group of experts for validity. As a result, 18 items were added to the core MDASI (the MDASI-BT) for the next phase of instrument development, establishing validity and reliability through a descriptive, cross-sectional approach with PBT patients. Data were collected with a patient completed demographic data sheet, an investigator completed clinician checklist, and the MDASI-BT. Analysis evaluated the reliability and validity of the MDASI-BT in PBT patients. Data were obtained from 201 patients. The number of items was reduced to 22 by evaluation of symptom severity as well as cluster analysis. Regression analysis showed more than half (56%) of the variability in symptom severity was explained by the brain tumor module items. Factor analysis confirmed that the 22 item MDASI-BT measured six underlying constructs: (a) affective; (b) cognitive; (c) focal neurologic deficits; (d) constitutional symptoms; (e) treatment-related symptoms; and (f) gastrointestinal symptoms. The MDASI-BT was sensitive to disease severity and if the patient was hospitalized. The MDASI-BT is the first instrument to measure symptoms in PBT patients that has demonstrated reliability and validity. It is the first step in a program of research to evaluate the occurrence of symptoms and plan and evaluate interventions for PBT patients. ^

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As the obesity epidemic continues to increase, the pediatric primary care office setting remains a relatively unexplored arena to offer obesity prevention interventions for children. The increased risk for adult obesity among 10 to 14 year-old children who are overweight, suggests obesity prevention programs should be introduced just before this age or early in this age period. Research is also accumulating on the importance of targeting parents along with children, since parents are in charge of the home environment for children. Therefore, the aim of this project was to develop an obesity prevention program called Helping HAND (Healthy Activity and Nutrition Directions) based on Social Cognitive Theory and authoritative parenting techniques for the pediatric primary care setting and conduct one-on-one interviews with parents as the initial formative evaluation of the intervention material for the obesity prevention intervention. A secondary aim of the project was to determine the feasibility of identifying appropriate subjects for the intervention, and conducting qualitative evaluations of the materials through recruitment through pediatric primary care settings. ^

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Cancer antigen 125 (CA125) is a tumor antigen that is routinely used to monitor the disease progress and the outcome of treatment in ovarian cancer patients. Elevated serum levels of CA125 are detected in over 80% of epithelial ovarian cancer patients. CA125 is a high molecular weight (>1M Dalton) mucin-type glycoprotein encoded by the MUC16 gene on human chromosome 19. Although MUC16 has served as the best serum marker for monitoring growth of ovarian cancer, roles for MUC16 in normal physiology and ovarian cancer are largely unknown. To understand the biological functions of MUC16, I characterized a mouse Muc16 homolog on chromosome 9 by means of expression pattern profiling, phenotype analysis of Muc16 knockout mice, and in vitro and in vivo studies of Muc16 null transformed ovarian surface epithelial (OSE) cells. ^ The mouse Muc16 homolog shares a conserved genomic structure with human MUC16. In addition to being expressed in mouse ovarian cancer, mouse Muc16 mRNA and protein were expressed in the mesothelia covering the heart, lung, ovary, oviduct, spleen, testis, and uterus. The conserved genomic structure and expression pattern of mouse Muc16 to human MUC16 suggests that mouse Muc16 is the ortholog of human MUC16. To understand the biological functions of Muc16, I generated Muc16 knockout mice. Muc16 knockout mice were viable, fertile and normal by one year of age. However, between 18 and 24 months of age, Muc16 knockout mice developed various tissue abnormalities such as ovarian cysts and tumors of the liver and other peritoneal organs. To determine the role of MUC16 in ovarian cancer progression, I established Muc16 null transformed ovarian surface epithelial (OSE) cell lines, following the same method to develop mouse model of epithelial ovarian cancer (Orsulic et al., 2002). Loss of Muc16 did not affect cell morphology, cell proliferation rate, or tumorigenic potential. However, Muc16-null OSE cells showed decreased attachment to extracellular matrix proteins as well as to primary mouse peritoneal mesothelial cells. Peritoneal mesothelia are the most frequent implantation sites of ovarian cancer. Furthermore, a pilot transplantation assay suggests that Muc16 null transformed OSE cells formed less disseminated tumors in the peritoneal cavity compared to wild-type OSE cells. ^ In conclusion, these results demonstrate that MUC16 is not required for normal mouse development or reproduction, but plays important roles in tissue homeostasis, ovarian cancer cell adhesion and dissemination. This study provides the first in vivo evidence of the roles of MUC16 in development, as well as ovarian cancer progression and dissemination. These studies offer valuable insights into possible mechanisms of ovarian cancer development and potential molecular targets for ovarian cancer treatment. ^

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DEVELOPMENT AND IMPLEMENTATION OF A DYNAMIC HETEROGENEOUS PROTON EQUIVALENT ANTHROPOMORPHIC THORAX PHANTOM FOR THE ASSESSMENT OF SCANNED PROTON BEAM THERAPY by James Leroy Neihart, B.S. APPROVED: ______________________________David Followill, Ph.D. ______________________________Peter Balter, Ph.D. ______________________________Narayan Sahoo, Ph.D. ______________________________Kenneth Hess, Ph.D. ______________________________Paige Summers, M.S. APPROVED: ____________________________ Dean, The University of Texas Graduate School of Biomedical Sciences at Houston DEVELOPMENT AND IMPLEMENTATION OF A DYNAMIC HETEROGENEOUS PROTON EQUIVALENT ANTHROPOMORPHIC THORAX PHANTOM FOR THE ASSESSMENT OF SCANNED PROTON BEAM THERAPY A THESIS Presented to the Faculty of The University of Texas Health Science Center at Houston andThe University of TexasMD Anderson Cancer CenterGraduate School of Biomedical Sciences in Partial Fulfillment of the Requirements for the Degree of MASTER OF SCIENCE by James Leroy Neihart, B.S. Houston, Texas Date of Graduation August, 2013 Acknowledgments I would like to acknowledge my advisory committee members, chair David Followill, Ph.D., Peter Balter, Ph.D, Narayan Sahoo, Ph.D., Kenneth Hess, Ph.D., Paige Summers M.S. and, for their time and effort contributed to this project. I would additionally like to thank the faculty and staff at the PTC-H and the RPC who assisted in many aspects of this project. Falk Pӧnisch, Ph.D. for his breath hold proton therapy treatment expertise, Matt Palmer and Jaques Bluett for proton dosimetry assistance, Matt Kerr for verification plan assistance, Carrie Amador, Nadia Hernandez, Trang Nguyen, Andrea Molineu, Lynda McDonald for TLD and film dosimetry assistance. Finally, I would like to thank my wife and family for their support and encouragement during my research and studies. Development and implementation of a dynamic heterogeneous proton equivalent anthropomorphic thorax phantom for the assessment of scanned proton beam therapy By: James Leroy Neihart, B.S. Chair of Advisory Committee: David Followill, Ph.D Proton therapy has been gaining ground recently in radiation oncology. To date, the most successful utilization of proton therapy is in head and neck cases as well as prostate cases. These tumor locations do not suffer from the resulting difficulties of treatment delivery as a result of respiratory motion. Lung tumors require either breath hold or motion tracking, neither of which have been assessed with an end-to-end phantom for proton treatments. Currently, the RPC does not have a dynamic thoracic phantom for proton therapy procedure assessment. Additionally, such a phantom could be an excellent means of assessing quality assurance of the procedures of proton therapy centers wishing to participate in clinical trials. An eventual goal of this phantom is to have a means of evaluating and auditing institutions for the ability to start clinical trials utilizing proton therapy procedures for lung cancers. Therefore, the hypothesis of this study is that a dynamic anthropomorphic thoracic phantom can be created to evaluate end-to-end proton therapy treatment procedures for lung cancer to assure agreement between the measured and calculated dose within 5% / 5 mm with a reproducibility of 2%. Multiple materials were assessed for thoracic heterogeneity equivalency. The phantom was designed from the materials found to be in greatest agreement. The phantom was treated in an end-to-end treatment four times, which included simulation, treatment planning and treatment delivery. Each treatment plan was delivered three times to assess reproducibility. The dose measured within the phantom was compared to that of the treatment plan. The hypothesis was fully supported for three of the treatment plans, but failed the reproducibility requirement for the most aggressive treatment plan.