123 research outputs found

    Ecological resilience at semi-arid and temperate boundaries of the Mediterranean-type Fynbos Biome, South Africa, during the Holocene

    Get PDF
    Mediterranean-type ecosystems are amongst the most vulnerable to global change. Threats from desertification are projected due to rapid expansion of adjacent semiarid systems. Changes in fire frequency and intensity can alter ecosystem composition and structure, and potentially facilitate transitions between alternative stable states. Given the outstanding biodiversity of the Mediterranean-type fynbos biome in the Greater Cape Floristic Region (GCFR) of South Africa, understanding of the longterm impacts of global change are particularly important. In this study, palaeoecological data are used to assess the effects of changes in climate, fire and land use on vegetation at the semi-arid and temperate margins of the fynbos biome. Previous palaeoecological studies have shown stable fynbos during the recent geologic past, which restricts interpretation of the long-term ecological processes that determine biome resilience. This study sourced sediment cores directly from presentday fynbos-succulent karoo (semi-arid) and fynbos-afrotemperate forest biome boundaries to emphasise ecological dynamics. Fossil pollen, spores and charcoal were extracted from radiocarbon dated sediment cores to provide proxies for vegetation, hydrology, large herbivore abundance and fire. Constrained hierarchical clustering (CONISS), optimal sequence splitting by least-squares, and Non-metric Multidimensional Scaling (NMDS) was applied to the fossil data to identify distinct assemblages in the record, and to further elucidate ecosystem trajectories through time. At the semi-arid boundary at Groenkloof (5,500 cal yrs BP - near present), decreased moisture and fire from 4,000-735 cal yrs BP allowed colonisation of fynbos by a possible 'no-analogue' community dominated by Asteraceae and Poaceae. From 735 cal yrs BP however, climatic amelioration allowed fynbos to re-establish. The system can therefore be viewed as resilient through a capacity for 'recovery' and persistence through turnover in internal composition of fynbos taxa. This sensitive response to climatic forcing reflects the dominant influence of physiological stress at the semiarid limits of Mediterranean-type ecosystems, as well as a Gleasonian type community composition with loose species associations. In contrast, ecosyste

    Prevalence of factors associated with edentulousness (no natural teeth) in adults with intellectual disabilities

    Get PDF
    Background: Poor oral health is largely preventable. Prevention includes toothbrushing and regular dental checks. Oral health has important consequences for general nutrition, chewing, communication, wider systemic disease, self‐confidence and participation in society. This study investigated the prevalence of edentulousness (no natural teeth) in adults with intellectual disabilities (IDs) compared with the general population and associated factors. Methods: An adult cohort with IDs residing in Greater Glasgow and Clyde, Scotland, underwent detailed health assessments between 2002 and 2004. Between 2004 and 2006, a subsample had an oral check. Data on edentulousness in the cohort were compared with adult participants from Greater Glasgow and Clyde in the 2008 Scottish Health Survey. Within the IDs cohort, binary logistic regression analyses investigated potential relationships between edentulousness and demographic and clinical factors. Results: Five hundred sixty adults with IDs were examined [53.2% (298) male, mean age = 46.3 years, range 18–81 years] and compared with 2547 general population: edentulousness was 9% vs. 1% aged 25–34 years; 22% vs. 2% aged 35–44 years; 39% vs. 7% aged 45–54 years; 41% vs. 18% aged 55–64 years; and 76% vs. 34% aged 65–74 years. In both groups, edentulousness increased with age. After stratification for age, rates of edentulousness were consistently higher in the ID cohort. Odds ratios within age strata were not homogenous (Mantel–Haenszel test, P < 0.0001). Edentulousness was more likely in those with more severe IDs (adjusted odds ratio (AOR) = 2.36; 95% confidence interval (CI) [1.23 to 4.51]); those taking antipsychotics (AOR = 2.09; 95% CI [1.25 to 3.51]) and those living in the most deprived neighbourhoods (AOR = 2.69; 95% CI [1.11 to 6.50]). There was insufficient evidence for associations with sex, type of accommodation/support, antiepileptics, problem behaviours or autism. Conclusions: Adults with IDs have a high prevalence of edentulousness and need supported daily oral care to reduce the need for extractions. Despite previous reports on poor oral care and the move towards person‐centred care, carers and care‐giving organisations need greater support to implement daily oral care. Prescribers need awareness of the potentially contributory role of antipsychotics, which may relate to xerostomia

    To respond or not to respond - a personal perspective of intestinal tolerance

    Get PDF
    For many years, the intestine was one of the poor relations of the immunology world, being a realm inhabited mostly by specialists and those interested in unusual phenomena. However, this has changed dramatically in recent years with the realization of how important the microbiota is in shaping immune function throughout the body, and almost every major immunology institution now includes the intestine as an area of interest. One of the most important aspects of the intestinal immune system is how it discriminates carefully between harmless and harmful antigens, in particular, its ability to generate active tolerance to materials such as commensal bacteria and food proteins. This phenomenon has been recognized for more than 100 years, and it is essential for preventing inflammatory disease in the intestine, but its basis remains enigmatic. Here, I discuss the progress that has been made in understanding oral tolerance during my 40 years in the field and highlight the topics that will be the focus of future research

    Mechanisms of T cell organotropism

    Get PDF
    F.M.M.-B. is supported by the British Heart Foundation, the Medical Research Council of the UK and the Gates Foundation

    Atypical Antipsychotics and Other Therapeutic Options for Treatment of Resistant Major Depressive Disorder

    No full text
    Antidepressant therapies, such as selective serotonin reuptake inhibitors (SSRIs), are current first-line treatments for Major Depressive Disorder. However, over 50% of treated patients show an inadequate response to initial antidepressant therapy. If the therapeutic outcomes from two antidepressant therapies are suboptimal, potentially resulting in Treatment Resistant Depression, subsequent strategies include switching to another antidepressant or augmenting treatment by combining with other agents. When combined with SSRIs, atypical antipsychotics have supplementary action on dopaminergic and noradrenergic systems. Studies on combined treatment with atypical antipsychotics have shown significantly increased remission rates, shortened response times, and favorable side effects. Augmentation of antidepressants with atypical antipsychotics is now an acceptable treatment strategy which leads to increased remission rates and better outcomes for patients

    Atypical Antipsychotics and Other Therapeutic Options for Treatment of Resistant Major Depressive Disorder

    No full text
    Antidepressant therapies, such as selective serotonin reuptake inhibitors (SSRIs), are current first-line treatments for Major Depressive Disorder. However, over 50% of treated patients show an inadequate response to initial antidepressant therapy. If the therapeutic outcomes from two antidepressant therapies are suboptimal, potentially resulting in Treatment Resistant Depression, subsequent strategies include switching to another antidepressant or augmenting treatment by combining with other agents. When combined with SSRIs, atypical antipsychotics have supplementary action on dopaminergic and noradrenergic systems. Studies on combined treatment with atypical antipsychotics have shown significantly increased remission rates, shortened response times, and favorable side effects. Augmentation of antidepressants with atypical antipsychotics is now an acceptable treatment strategy which leads to increased remission rates and better outcomes for patients

    Why strategic organisational learning and why now?

    No full text
    Special Issue Introductio

    Spectral ripple discrimination in children with auditory processing disorder

    No full text
    Objective: The purpose of this study was to examine developmental trends in spectral ripple discrimination (SRD) and to compare the performance of typically developing children to children with auditory processing disorder (APD). Study design: Cross-sectional study. Study sample: Fifteen children with APD, as well as 17 typically developing children and 14 adults reporting no listening or academic difficulties participated. Results: Typically developing children showed poor SRD thresholds compared to adults, indicating prolonged maturation of spectral shape recognition. Both typically developing children and APD children showed a maturational trend in SRD, but a General Linear Model fit to their thresholds showed that children with APD displayed SRD thresholds that were significantly poorer than those of typically developing children when controlling for age. This suggests that in APD children, SRD maturation lags behind typically developing children. Conclusion: Poor spectral ripple discrimination may explain some of the listening difficulties experienced by children with APD
    • 

    corecore