35 research outputs found

    Immunosenescence in wild animals:Meta-analysis and outlook

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    Immunosenescence, the decline in immune defense with age, is an important mortality source in elderly humans but little is known of immunosenescence in wild animals. We systematically reviewed and meta-analysed evidence for age-related changes in immunity in captive and free-living populations of wild species (321 effect sizes in 62 studies across 44 species of mammals, birds and reptiles). As in humans, senescence was more evident in adaptive (acquired) than innate immune functions. Declines were evident for cell function (antibody response), the relative abundance of naive immune cells and an in vivo measure of overall immune responsiveness (local response to phytohaemagglutinin injection). Inflammatory markers increased with age, similar to chronic inflammation associated with human immunosenescence. Comparisons across taxa and captive vs free-living animals were difficult due to lack of overlap in parameters and species measured. Most studies are cross-sectional, which yields biased estimates of age-effects when immune function co-varies with survival. We therefore suggest longitudinal sampling approaches, and highlight techniques from human cohort studies that can be incorporated into ecological research. We also identify avenues to address predictions from evolutionary theory and the contribution of immunosenescence to age-related increases in disease susceptibility and mortality

    Digital technology and governance in transition: The case of the British Library

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    Comment on the organizational consequences of the new information and communications technologies (ICTs) is pervaded by a powerful imagery of disaggregation and a tendency for ?virtual? forms of production to be seen as synonymous with the ?end? of bureaucracy. This paper questions the underlying assumptions of the ?virtual organization?, highlighting the historically enduring, diversified character of the bureaucratic form. The paper then presents case study findings on the web-based access to information resources now being provided by the British Library (BL). The case study evidence produces two main findings. First, radically decentralised virtual forms of service delivery are heavily dependent on new forms of capacity-building and information aggregation. Second, digital technology is embedded in an inherently contested and contradictory context of institutional change. Current developments in the management and control of digital rights are consistent with the commodification of the public sphere. However, the evidence also suggests that scholarly access to information resources is being significantly influenced by the ?information society? objectives of the BL and other institutional players within the network of UK research libraries

    Amyloid and tau pathology associations with personality traits, neuropsychiatric symptoms, and cognitive lifestyle in the preclinical phases of sporadic and autosomal dominant Alzheimer’s disease

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    Background Major prevention trials for Alzheimer’s disease (AD) are now focusing on multidomain lifestyle interventions. However, the exact combination of behavioral factors related to AD pathology remains unclear. In 2 cohorts of cognitively unimpaired individuals at risk of AD, we examined which combinations of personality traits, neuropsychiatric symptoms, and cognitive lifestyle (years of education or lifetime cognitive activity) related to the pathological hallmarks of AD, amyloid-β, and tau deposits. Methods A total of 115 older adults with a parental or multiple-sibling family history of sporadic AD (PREVENT-AD [PRe-symptomatic EValuation of Experimental or Novel Treatments for AD] cohort) underwent amyloid and tau positron emission tomography and answered several questionnaires related to behavioral attributes. Separately, we studied 117 mutation carriers from the DIAN (Dominant Inherited Alzheimer Network) study group cohort with amyloid positron emission tomography and behavioral data. Using partial least squares analysis, we identified latent variables relating amyloid or tau pathology with combinations of personality traits, neuropsychiatric symptoms, and cognitive lifestyle. Results In PREVENT-AD, lower neuroticism, neuropsychiatric burden, and higher education were associated with less amyloid deposition (p = .014). Lower neuroticism and neuropsychiatric features, along with higher measures of openness and extraversion, were related to less tau deposition (p = .006). In DIAN, lower neuropsychiatric burden and higher education were also associated with less amyloid (p = .005). The combination of these factors accounted for up to 14% of AD pathology. Conclusions In the preclinical phase of both sporadic and autosomal dominant AD, multiple behavioral features were associated with AD pathology. These results may suggest potential pathways by which multidomain interventions might help delay AD onset or progression

    The Cholecystectomy As A Day Case (CAAD) Score: A Validated Score of Preoperative Predictors of Successful Day-Case Cholecystectomy Using the CholeS Data Set

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    Background Day-case surgery is associated with significant patient and cost benefits. However, only 43% of cholecystectomy patients are discharged home the same day. One hypothesis is day-case cholecystectomy rates, defined as patients discharged the same day as their operation, may be improved by better assessment of patients using standard preoperative variables. Methods Data were extracted from a prospectively collected data set of cholecystectomy patients from 166 UK and Irish hospitals (CholeS). Cholecystectomies performed as elective procedures were divided into main (75%) and validation (25%) data sets. Preoperative predictors were identified, and a risk score of failed day case was devised using multivariate logistic regression. Receiver operating curve analysis was used to validate the score in the validation data set. Results Of the 7426 elective cholecystectomies performed, 49% of these were discharged home the same day. Same-day discharge following cholecystectomy was less likely with older patients (OR 0.18, 95% CI 0.15–0.23), higher ASA scores (OR 0.19, 95% CI 0.15–0.23), complicated cholelithiasis (OR 0.38, 95% CI 0.31 to 0.48), male gender (OR 0.66, 95% CI 0.58–0.74), previous acute gallstone-related admissions (OR 0.54, 95% CI 0.48–0.60) and preoperative endoscopic intervention (OR 0.40, 95% CI 0.34–0.47). The CAAD score was developed using these variables. When applied to the validation subgroup, a CAAD score of ≤5 was associated with 80.8% successful day-case cholecystectomy compared with 19.2% associated with a CAAD score >5 (p < 0.001). Conclusions The CAAD score which utilises data readily available from clinic letters and electronic sources can predict same-day discharges following cholecystectomy

    Poor oral health as a chronic, potentially modifiable dementia risk factor: Review of the literature topical collection on dementia

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    Poor oral health, including caries, tooth loss, and periodontitis, is ubiquitous worldwide, and is potentially treatable and preventable. Like adverse oral health conditions, Alzheimer disease and related disorders are also very common among aging populations. Established risk factors for Alzheimer disease include cerebrovascular disease and its vascular risk factors, many of which share associations with evidence of systemic inflammation also identified in periodontitis and other poor oral health states. In this review, we present epidemiologic evidence of links between poor oral health and both prevalent and incident cognitive impairment, and review plausible mechanisms linking these conditions, including evidence from compelling animal models. Considering that a large etiologic fraction of dementia remains unexplained, these studies argue for further multidisciplinary research between oral health conditions, including translational, epidemiologic, and possibly clinical treatment studies. © 2013 Springer Science+Business Media New York

    Risk mapping of soil acidification under Stylosanthes in northern Australian rangelands

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    The inclusion of Stylosanthes into pastures and cropping systems has proved to be a low cost method of improving product quality in Asia, Africa, South America, and northern Australia. However, there is recent evidence that accelerated soil acidification has occurred under these production systems, questioning their long-term sustainability. In an effort to assist producers and extension officers in identifying soils that are predisposed to accelerated acidification, an acidity risk map of the Dalrymple Shire in Queensland, Australia, was developed using information from a recently completed land resource survey. Validation of a previously derived pedotransfer function that predicts pH buffering capacity was undertaken using an independent set of soil samples collected from the Shire. Excellent agreement between measured and predicted pH buffering capacity was obtained. The pedotransfer function was used to estimate the pH buffering capacity of 44 soil associations in the Shire. These values were used to predict the number of years that it would take for soils to acidify from their current pH to 5.0 assuming a constant net acid addition rate of 2.1 kmol H+/ha.year. Approximately 62% of the total area of the Shire is predisposed to accelerated acidification and would take between 10–20 years to acidify to pH 5.0. In contrast, a relatively minor proportion of the total area of the Shire (17%) had significant internal buffering capacity. However, the degree of uncertainty associated with these estimations on certain soil associations may be too high to be of relevance. In order to overcome this limitation a field test designed to assess the risk of accelerated acidification on a paddock basis is proposed and outlined in the paper

    Production of `green' concrete using red gypsum and waste

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    The main cost incurred in the production of concrete paving blocks is the cost of the cement-based binders. In addition, there is the environmental cost of quarrying and processing of these primary materials. Gypsum-based industrial by-products have been identified as alternative sources of cement. These materials have little or no production cost and their reuse negates the need for disposal, offering a more sustainable material for the production of paving blocks. Laboratory trials have investigated the properties of red gypsum, derived as a coproduct associated with titanium dioxide manufacture, mixed with pulverised-fuel ash, ground granulated blastfurnace slag, lime and basic steel slag. An assessment of samples was made using unconfined compressive strength after 28 days curing. It was found that a red gypsum ground granulated blastfurnace slag mix achieved the highest unconfined compressive strength (up to 39 MPa) and was selected for further investigation. Two binders, composed primarily of red gypsum and ground granulated blastfurnace slag, were mixed with sand and pea gravel to make 100 mm concrete cubes and compared with Portland cement for uniaxial compressive strength, stiffness and workability. The red gypsum-based binder compared favourably with Portland cement, indicating that there is potential to integrate red gypsum into concrete block mixes. </jats:p

    Serum IgG antibody levels to periodontal microbiota are associated with incident alzheimer disease

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    Background: Periodontitis and Alzheimer disease (AD) are associated with systemic inflammation. This research studied serum IgG to periodontal microbiota as possible predictors of incident AD. Methods: Using a case-cohort study design, 219 subjects (110 incident AD cases and 109 controls without incident cognitive impairment at last follow-up), matched on race-ethnicity, were drawn from the Washington Heights-Inwood Columbia Aging Project (WHICAP), a cohort of longitudinally followed northern Manhattan residents aged &gt;65 years. Mean follow-up was five years (SD 2.6). In baseline sera, serum IgG levels were determined for bacteria known to be positively or negatively associated with periodontitis (Porphyromonas gingivalis, Tannerella forsythia, Actinobacillus actinomycetemcomitans Y4, Treponema denticola, Campylobacter rectus, Eubacterium nodatum, and Actinomyces naeslundii genospecies-2). In all analyses, we used antibody threshold levels shown to correlate with presence of moderate-severe periodontitis. Results: Mean age was 72 years (SD 6.9) for controls, and 79 years (SD 4.6) for cases (p&lt;0.001). Non-Hispanic Whites comprised 26%, non-Hispanic Blacks 27%, and Hispanics 48% of the sample. In a model adjusting for baseline age, sex, education, diabetes mellitus, hypertension, smoking, prior history of stroke, and apolipoprotein E genotype, high anti-A. naeslundii titer (&gt;640 ng/ml, present in 10% of subjects) was associated with increased risk of AD (HR=2.0, 95%CI: 1.1-3.8). This association was stronger after adjusting for other significant titers (HR=3.1, 95%CI: 1.5-6.4). In this model, high anti-E. nodatum IgG (&gt;1755 ng/ml; 19% of subjects) was associated with lower risk of AD (HR=0.5, 95%CI: 0.2-0.9). Conclusions: Serum IgG levels to common periodontal microbiota are associated with risk for developing incident AD. © 2014 Noble et al
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