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Selected AbstractsAgeing, oxidative stress, and mitochondrial uncouplingACTA PHYSIOLOGICA, Issue 4 2004M.-E. Harper Abstract Mitochondria are a cell's single greatest source of reactive oxygen species. Reactive oxygen species are important for many life sustaining processes of cells and tissues, but they can also induce cell damage and death. If their production and levels within cells is not effectively controlled, then the detrimental effects of oxidative stress can accumulate. Oxidative stress is widely thought to underpin many ageing processes, and the oxidative stress theory of ageing is one of the most widely acknowledged theories of ageing. As well as being the major source of reactive oxygen species, mitochondria are also a major site of oxidative damage. The purpose of this review is a concise and current review of the effects of oxidative stress and ageing on mitochondrial function. Emphasis is placed upon the roles of mitochondrial proton leak, the uncoupling proteins, and the anti-ageing effects of caloric restriction. [source] Patterns of bacterial diversity across a range of Antarctic terrestrial habitatsENVIRONMENTAL MICROBIOLOGY, Issue 11 2007Etienne Yergeau Summary Although soil-borne bacteria represent the world's greatest source of biological diversity, it is not well understood whether extreme environmental conditions, such as those found in Antarctic habitats, result in reduced soil-borne microbial diversity. To address this issue, patterns of bacterial diversity were studied in soils sampled along a > 3200 km southern polar transect spanning a gradient of increased climate severity over 27° of latitude. Vegetated and fell-field plots were sampled at the Falkland (51°S), South Georgia (54°S), Signy (60°S) and Anchorage Islands (67°S), while bare frost-sorted soil polygons were examined at Fossil Bluff (71°S), Mars Oasis (72°S), Coal Nunatak (72°S) and the Ellsworth Mountains (78°S). Bacterial 16S rRNA gene sequences were recovered subsequent to direct DNA extraction from soil, polymerase chain reaction amplification and cloning. Although bacterial diversity was observed to decline with increased latitude, habitat-specific patterns appeared to also be important. Namely, a negative relationship was found between bacterial diversity and latitude for fell-field soils, but no such pattern was observed for vegetated sites. The Mars Oasis site, previously identified as a biodiversity hotspot within this region, proved exceptional within the study transect, with unusually high bacterial diversity. In independent analyses, geographical distance and vegetation cover were found to significantly influence bacterial community composition. These results provide insight into the factors shaping the composition of bacterial communities in Antarctic terrestrial habitats and support the notion that bacterial diversity declines with increased climatic severity. [source] Healthcare Proxies of Nursing Home Residents with Advanced Dementia: Decisions They Confront and Their Satisfaction with Decision-MakingJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 7 2009Jane L. Givens MD OBJECTIVES: To describe the medical decisions confronting healthcare proxies (HCPs) of nursing home (NH) residents with advanced dementia and to identify factors associated with greater decision-making satisfaction. DESIGN: Prospective cohort study. SETTING: Twenty-two Boston-area NHs. PARTICIPANTS: Three hundred twenty-three NH residents with advanced dementia and their HCPs. MEASUREMENTS: Decisions made by HCPs over 18 months were ascertained quarterly. After making a decision, HCPs completed the Decision Satisfaction Inventory (DSI) (range 0,100). Independent variables included HCP and resident sociodemographic characteristics, health status, and advance care planning. Multivariable linear regression identified factors associated with higher DSI scores (greater satisfaction). RESULTS: Of 323 HCPs, 123 (38.1%) recalled making at least one medical decision; 232 decisions were made, concerning feeding problems (27.2%), infections (20.7%), pain (12.9%), dyspnea (8.2%), behavior problems (6.9%), hospitalizations (3.9%), cancer (3.0%), and other complications (17.2%). Mean DSI scoreħstandard deviation was 78.4ħ19.5, indicating high overall satisfaction. NH provider involvement in shared decision-making was the area of least satisfaction. In adjusted analysis, greater decision-making satisfaction was associated with the resident living on a special care dementia unit (P=.002), greater resident comfort (P=.004), and the HCP not being the resident's child (P=.02). CONCLUSION: HCPs of NH patients with advanced dementia can most commonly expect to encounter medical decisions relating to feeding problems, infections, and pain. Inadequate support from NH providers is the greatest source of HCP dissatisfaction with decision-making. Greater resident comfort and care in a special care dementia unit are potentially modifiable factors associated with greater decision-making satisfaction. [source] Electron microscopic detection of statherin in secretory granules of human major salivary glandsJOURNAL OF ANATOMY, Issue 5 2008M. Isola Abstract In order to increase current knowledge regarding statherin secretion into the oral cavity, ultrastructural localization of this peptide was investigated in human salivary glands by using a post-embedding immunogold staining technique. Statherin reactivity was found inside the granules of serous cells of parotid and submandibular glands. In parotid granules immunostaining was preferentially present in the less electron-dense region, whereas in submandibular serous granules the reactivity was uniform and the dense core always stained. By contrast, none or weak reactivity was observed in serous cells of major sublingual glands. These findings reveal for the first time the subcellular localization of statherin by electron transmission microscopy and confirm that of the three major types of salivary glands, the parotid and submandibular glands are the greatest source of salivary statherin. Moreover, they suggest that more than one packaging mechanism may be involved in the storage of statherin within serous granules of salivary glands. [source] Voluntary turnover among nurses working in Kuwaiti hospitalsJOURNAL OF NURSING MANAGEMENT, Issue 3 2008MUHAMMAD ALOTAIBI BSN Background, Voluntary turnover rates are high among staff nurses working in Kuwaiti hospitals. It is a major problem, costly and it is presumed to impact on the quality of nursing care delivered. Aims, The two aims of this study were to (1) find out if nurses' resignations in Kuwaiti hospitals could be ascribed to failure in the recruitment process and (2) examine the feelings of nurses who resigned. Methods, Two sets of exit interviews with 60 nurses who had resigned were conducted. Results, No evidence emerged that any false information or misleading information was provided except for the salary adjustments. The real insight lay in what might not have been said in the recruitment interviews. While feelings of discontent emerged in the interviews relating to the loss of income, the greatest source of complaint related to the failure of managers to solve the evident problems. Conclusions, High rates of voluntary turnover require more attention from administrators and policy makers because of its potential consequences in terms of the quality of nursing care delivered. Implications for nursing management, This paper identifies many causes of nurses' voluntary turnover. It also shows the need for nursing managers to explore these causes and suggests successful strategies for recruitment and retention practices and policies. [source] EFFECTS OF WATERCRAFT NOISE ON THE ACOUSTIC BEHAVIOR OF BOTTLENOSE DOLPHINS, TURSIOPS TRUNCATUS, IN SARASOTA BAY, FLORIDAMARINE MAMMAL SCIENCE, Issue 4 2004Kara C. Buckstaff Abstract Watercraft may provide the greatest source of anthropogenic noise for bottlenose dolphins living in coastal waters. A resident community of about 140 individuals near Sarasota, Florida, are exposed to a vessel passing within 100 m approximately every six minutes during daylight hours. I investigated the circumstances under which watercraft traffic may impact the acoustic behavior of this community, specifically looking for short-term changes in whistle frequency range, duration, and rate of production. To analyze whistles and received watercraft noise levels, acoustic recordings were made using two hydrophones towed from an observation vessel during focal animal follows of 14 individual dolphins. The duration and frequency range of signature whistles did not change significantly relative to vessel approaches. However, dolphins whistled significantly more often at the onset of approaches compared to during and after vessel approaches. Whistle rate was also significantly greater at the onset of a vessel approach than when no vessels were present. Increased whistle repetition as watercraft approach may simply reflect heightened arousal, an increased motivation for animals to come closer together, with whistles functioning to promote reunions. It may also be an effective way to compensate for signal masking, maintaining communication in a noisy environment. [source] Recent veterinary graduates over the last five decades: recollections and perceptionsAUSTRALIAN VETERINARY JOURNAL, Issue 11 2005TJ HEATH Objective To describe the attitudes of veterinary graduates over the last 50 years to their experiences as recent graduates Design A questionnaire, sent by mail. Procedure A questionnaire seeking information on experiences as a recent graduate was sent to about 100 veterinarians who graduated in or about 1950, 1960, 1970, 1980, 1990 and 2000, and 68% responded. Data were entered onto an Excel spreadsheet, and analysed with the SAS System 8 for Windows. Results Most veterinarians who graduated in 1970 and earlier were generally satisfied with their conditions, even though these were often taxing. In the 1970s the cattle industry faltered and rural practice suffered a downturn. Veterinary positions became scarce, and there were few opportunities for graduates to move on from an unsatisfactory workplace - as many were at that time. By 1980 many recent graduates were questioning their decision to study veterinary science. Many of them, working long hours under often stressful conditions, felt that that they were not receiving adequate help or support - or remuneration - from their employers, or respect from their clients. This also afflicted many who graduated in 1990, but by 2000 graduates were reporting an improvement. Their hours of work and the expectations placed on them were more manageable, and the level of help and support, and remuneration, were more acceptable. As a result they found their first year much more enjoyable than had those who had graduated since about 1970. Many of the factors contributing to this improvement resulted from changes in society generally. Specifically, both graduates and employers have become more conscious of what might reasonably be expected, an Award specified minimum levels, the AVA started accrediting New Graduate Friendly Practices, publishing a most informative New Graduate Guide, and helping in other ways. Remuneration, especially when compared with comparable professions, continues to be a source of discontent. Furthermore, despite improved conditions on average, many graduates still suffer under substandard conditions, and these can have an adverse effect on their health and their attitude to their career in veterinary science. Conclusions Average conditions of employment of recent veterinary graduates have improved somewhat after a nadir in the 1970s and 1980s, but they are still substandard for some. Remuneration remains the greatest source of dissatisfaction for recent graduates. [source] | |||||||||||||