Causes of increasing aridification of the Mediterranean region in response to rising greenhouse gases

The hydrological cycle in the Mediterranean region, as well as its change over the coming decades, is investigated using the Interim European Centre for Medium-Range Weather Forecasts Re-Analysis (ERA-Interim) and phase 5 of the Coupled Model Intercomparison Project (CMIP5) historical simulations and projections of the coming decades. The Mediterranean land regions have positive precipitation minus evaporation, P-E, in winter and negative P-E in summer. According to ERA-Interim, positive P-E over land in winter is sustained by transient eddy moisture convergence and opposed by mean flow moisture divergence. Dry mean flow advection is important for opposing the transient eddy moisture flux convergence in the winter half year and the mass divergent mean flow is a prime cause of negative P-E in the summer half year. These features are well reproduced in the CMIP5 ensemble. The models predict reduced P-E over the Mediterranean region in the future year-round. For both land and sea, a common cause of drying is increased mean flow moisture divergence. Changes in transient eddy moisture fluxes largely act diffusively and cause drying over the sea and moistening over many land areas to the north in winter and drying over western land areas and moistening over the eastern sea in summer. Increased mean flow moisture divergence is caused by both the increase in atmospheric humidity in a region of mean flow divergence and strengthening of the mass divergence. Increased mass divergence is related to increased high pressure over the central Mediterranean in winter and over the Atlantic and northern Europe in summer, which favors subsidence and low-level divergence over the Mediterranean region

BACE1 activity impairs neuronal glucose oxidation:rescue by beta-hydroxybutyrate and lipoic acid

Glucose hypometabolism and impaired mitochondrial function in neurons have been suggested to play early and perhaps causative roles in Alzheimer's disease (AD) pathogenesis. Activity of the aspartic acid protease, beta-site amyloid precursor protein (APP) cleaving enzyme 1 (BACE1), responsible for beta amyloid peptide generation, has recently been demonstrated to modify glucose metabolism. We therefore examined, using a human neuroblastoma (SH-SY5Y) cell line, whether increased BACE1 activity is responsible for a reduction in cellular glucose metabolism. Overexpression of active BACE1, but not a protease-dead mutant BACE1, protein in SH-SY5Y cells reduced glucose oxidation and the basal oxygen consumption rate, which was associated with a compensatory increase in glycolysis. Increased BACE1 activity had no effect on the mitochondrial electron transfer process but was found to diminish substrate delivery to the mitochondria by inhibition of key mitochondrial decarboxylation reaction enzymes. This BACE1 activity-dependent deficit in glucose oxidation was alleviated by the presence of beta hydroxybutyrate or α-lipoic acid. Consequently our data indicate that raised cellular BACE1 activity drives reduced glucose oxidation in a human neuronal cell line through impairments in the activity of specific tricarboxylic acid cycle enzymes. Because this bioenergetic deficit is recoverable by neutraceutical compounds we suggest that such agents, perhaps in conjunction with BACE1 inhibitors, may be an effective therapeutic strategy in the early-stage management or treatment of AD

Dynamical and Thermodynamical Causes of Large-Scale Changes in the Hydrological Cycle over North America in Response to Global Warming

The mechanisms of model-projected atmospheric moisture budget change across North America are examined in simulations conducted with 22 models from phase 5 of the Coupled Model Intercomparison Project. Modern-day model budgets are validated against the European Centre for Medium-Range Weather Forecasts Interim Re-Analysis. In the winter half year transient eddies converge moisture across the continent while the mean flow wets the west from central California northward and dries the southwest. In the summer half year there is widespread mean flow moisture divergence across the west and convergence over the Great Plains that is offset by transient eddy divergence. In the winter half year the models project drying for the southwest and wetting to the north. Changes in the mean flow moisture convergence are largely responsible across the west but intensified transient eddy moisture convergence wets the northeast. In the summer half year widespread declines in precipitation minus evaporation (P-E) are supported by mean flow moisture divergence across the west and transient eddy divergence in the Great Plains. The changes in mean flow convergence are related to increases in specific humidity but also depend on changes in the mean flow including increased low-level divergence in the U.S. Southwest and a zonally varying wave that wets the North American west and east coasts in winter and dries the U.S. Southwest. Increased transient eddy fluxes occur even as low-level eddy activity weakens and arise from strengthened humidity gradients. A full explanation of North American hydroclimate changes will require ex- planation of mean and transient circulation changes and the coupling between the moisture and circulation fields

A comprehensive model of factors associated with subjective perceptions of living well with dementia: findings from the IDEAL study

Background: The concept of ‘living well’ is increasingly used to indicate that it is, or should be, possible for a person living with dementia to experience a subjective sense of ‘comfort, function and contentment with life.’ We used a theoretically-derived conceptual framework to investigate capability to ‘live well’ with dementia through identifying the relative contribution of domains associated with the subjective experience of living well. Methods: We analysed data from 1550 community-dwelling individuals with mild to moderate dementia participating in the baseline wave of the Improving the experience of Dementia and Enhancing Active Life (IDEAL) cohort study. Subjective perceptions of ability to live well were obtained by generating a living well latent factor from responses on the Quality of Life in Alzheimer’s disease (QoL-AD), Satisfaction with Life and WHO-5 Well-being scales. Multivariate modelling and structural equation modelling was used to investigate variables potentially associated with living well. Variables were grouped into five domains, latent variables were constructed representing Social Location, Capitals, Assets and Resources, Psychological Characteristics and Psychological Health, Physical Fitness and Health, and Managing Everyday Life with Dementia, and associations with living well were examined. All models were adjusted for age, sex and dementia sub-type. Results: Considering the domains singly, the Psychological Characteristics and Psychological Health domain was most strongly associated with living well (3.56; 95% CI: 2.25, 4.88), followed by Physical Fitness and Physical Health (1.10, 95% CI: -2.26, 4.47). Effect sizes were smaller for Capitals, Assets and Resources (0.53; 95% CI: -0.66, 1.73), Managing Everyday Life with Dementia (0.34; 95% CI: 0.20, 0.87), and Social Location (-0.12; 95% CI: -5.72, 5.47). Following adjustment for the Psychological Characteristics and Psychological Health domain, other domains did not show independent associations with living well. Conclusions: Psychological resources are central to subjective perceptions of living well and offer important targets for immediate intervention. Availability of social and environmental resources, and physical fitness, underpin these positive psychological states, and also offer potential targets for interventions and initiatives aimed at improving the experience of living with dementia

A comprehensive model of factors associated with subjective perceptions of living well with dementia: findings from the IDEAL study

Background: The concept of ‘living well’ is increasingly used to indicate that it is, or should be, possible for a person living with dementia to experience a subjective sense of ‘comfort, function and contentment with life.’ We used a theoretically-derived conceptual framework to investigate capability to ‘live well’ with dementia through identifying the relative contribution of domains associated with the subjective experience of living well. Methods: We analysed data from 1550 community-dwelling individuals with mild to moderate dementia participating in the baseline wave of the Improving the experience of Dementia and Enhancing Active Life (IDEAL) cohort study. Subjective perceptions of ability to live well were obtained by generating a living well latent factor from responses on the Quality of Life in Alzheimer’s disease (QoL-AD), Satisfaction with Life and WHO-5 Well-being scales. Multivariate modelling and structural equation modelling was used to investigate variables potentially associated with living well. Variables were grouped into five domains, latent variables were constructed representing Social Location, Capitals, Assets and Resources, Psychological Characteristics and Psychological Health, Physical Fitness and Health, and Managing Everyday Life with Dementia, and associations with living well were examined. All models were adjusted for age, sex and dementia sub-type. Results: Considering the domains singly, the Psychological Characteristics and Psychological Health domain was most strongly associated with living well (3.56; 95% CI: 2.25, 4.88), followed by Physical Fitness and Physical Health (1.10, 95% CI: -2.26, 4.47). Effect sizes were smaller for Capitals, Assets and Resources (0.53; 95% CI: -0.66, 1.73), Managing Everyday Life with Dementia (0.34; 95% CI: 0.20, 0.87), and Social Location (-0.12; 95% CI: -5.72, 5.47). Following adjustment for the Psychological Characteristics and Psychological Health domain, other domains did not show independent associations with living well. Conclusions: Psychological resources are central to subjective perceptions of living well and offer important targets for immediate intervention. Availability of social and environmental resources, and physical fitness, underpin these positive psychological states, and also offer potential targets for interventions and initiatives aimed at improving the experience of living with dementia

What can crop stable isotopes ever do for us? An experimental perspective on using crop carbon stable isotope values for reconstructing water availability in semi-arid and arid environments

This study re-assesses and refines the use of crop carbon stable isotopes (Δ13C) to reconstruct past water availability. Durum wheat, six-row barley, and sorghum were experimentally grown at three crop growing stations in Jordan for up to three years under five different irrigation regimes: 0% (rainfall only), 40%, 80%, 100%, and 120% of the crops’ optimum water requirements. Results show large variation in carbon stable isotopes for crops that received similar amounts of water, either as absolute water input or as percentage of crop requirements. We conclude that C3 crop carbon stable isotope composition can therefore be best interpreted in terms of extremely high values showing an abundance of water versus low values indicating water-stress. Values in between these extremes are problematic and best interpreted in conjunction with other proxies. C4 crop isotopes were not found to be useful for the reconstruction of water availability

The impact of dementia, age and sex on category fluency: Greater deficits in women with Alzheimer's disease

Original article can be found at: http://www.sciencedirect.com/science/journal/00109452 Copyright Elsevier Masson DOI: 10.1016/j.cortex.2007.11.008A category specific effect in naming tasks has been reported in patients with Alzheimer's dementia. Nonetheless, naming tasks are frequently affected by methodological problems, e.g., ceiling effects for controls and “nuisance variables” that may confound results. Semantic fluency tasks could help to address some of these methodological difficulties, because they are not prone to producing ceiling effects and are less influenced by nuisance variables. One hundred and thirty-three participants (61 patients with probable AD; and 72 controls: 36 young and 36 elderly) were evaluated with semantic fluency tasks in 14 semantic categories. Category fluency was affected both by dementia and by age: while in nonliving-thing categories there were differences among the three groups, in living thing categories larger lexical categories produced bigger differences among groups. Sex differences in fluency emerged, but these were moderated both by age and by pathology. In particular, fluency was smaller in female than male Alzheimer patients for almost every subcategory.Peer reviewe

Positive experiences in dementia care-giving: findings from the IDEAL programme

There is a growing evidence base that identifying positive experiences in providing care can have a beneficial influence on carer wellbeing. However, there is a need to better understand what carers identify as the positive aspects of care-giving. The aim of this study is to explore the satisfying aspects of providing care to people with dementia. This study utilised Time 1 data from 1,277 carers of people in the mild-to-moderate stages of dementia taking part in the IDEAL (Improving the experience of Dementia and Enhancing Active Life) cohort study. Responses from 900 carers who answered the open-ended question ‘What is your greatest satisfaction in caring for your relative/friend?’ were analysed using thematic analysis. From the responses, 839 carers detailed satisfactions. Eight themes were identified, pertaining to three groups of beneficiaries: carers, people with dementia and the dyad. Perceived benefits for carers included identifying aspects of personal growth, seeing glimpses of the person, feeling they were making a difference and doing their duty. For the person with dementia, these included retaining independence, receiving good quality care and being happy. Dyadic benefits concerned the continuation of the relationship between carer and person with dementia. The findings highlight the need to take a dyadic approach when conceptualising positive experiences in providing care. Further research is needed to understand the role these positive experiences play and to develop interventions. Professionals working with carers should identify and validate these experiences