First principles LDA+U and GGA+U study of cerium oxides: Dependence on the effective U-parameter

The electronic structure and properties of cerium oxides (CeO2 and Ce2O3) have been studied in the framework of the LDA+U and GGA(PW91)+U implementations of density functional theory. The dependence of selected observables of these materials on the effective U parameter has been investigated in detail. The examined properties include lattice constants, bulk moduli, density of states, and formation energies of CeO2 and Ce2O3. For CeO2, the LDA+U results are in better agreement with experiment than the GGA+U results whereas for the computationally more demanding Ce2O3 both approaches give comparable accuracy. Furthermore, as expected, Ce2O3 is much more sensitive to the choice of the U value. Generally, the PW91 functional provides an optimal agreement with experiment at lower U energies than LDA does. In order to achieve a balanced description of both kinds of materials, and also of nonstoichiometric CeO2¿x phases, an appropriate choice of U is suggested for LDA+U and GGA+U schemes. Nevertheless, an optimum value appears to be property dependent, especially for Ce2O3. Optimum U values are found to be, in general, larger than values determined previously in a self-consistent way.

The economic burden of alcohol dependence in europe.

AIMS: To determine the economic burden pertaining to alcohol dependence in Europe. METHODS: Database searching was combined with grey literature searching to identify costs and resource use in Europe relating to alcohol dependence as defined by the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) or the World Health Organisation's International Classification of Diseases (ICD-10). Searches combined MeSH headings for both economic terms and terms pertaining to alcohol dependence. Relevant outcomes included direct healthcare costs and indirect societal costs. Main resource use outcomes included hospitalization and drug costs. RESULTS: Compared with the number of studies of the burden of alcohol use disorders in general, relatively few focussed specifically on alcohol dependence. Twenty-two studies of variable quality were eligible for inclusion. The direct costs of alcohol dependence in Europe were substantial, the treatment costs for a single alcohol-dependent patient lying within the range euro1591-euro7702 per hospitalization and the annual total direct costs accounting for 0.04-0.31% of an individual country's gross domestic product (GDP). These costs were driven primarily by hospitalization; in contrast, the annual drug costs for alcohol dependence were low. The indirect costs were more substantial than the direct costs, accounting for up to 0.64% of GDP per country annually. Alcohol dependence may be more costly in terms of health costs per patient than alcohol abuse. CONCLUSIONS: This review confirms that alcohol dependence represents a significant burden for European healthcare systems and society. Difficulties in comparing across cost-of-illness studies in this disease area, however, prevent specific estimation of the economic burden.

Serial brain (18)FDG-PET in anti-AMPA receptor limbic encephalitis.

Immunotherapy-responsive autoimmune CNS syndromes linked to antibodies targeting surface neuronal antigens lack reliable biomarkers of disease activity. We report serial cerebral (18)FDG PET studies in a woman with AMPA receptor (AMPA-R) autoimmune limbic encephalitis. During her follow-up, despite an aggressive immunotherapy, she displayed a persistent, predominantly left hippocampal FDG hypermetabolism, in the absence of CNS inflammatory signs. Brain metabolism abnormalities regressed after increasing antiepileptic treatment, correlating with a moderate clinical improvement. Brain (18)F-FDG PET could thus represent a useful complementary tool to orient the clinical follow-up.

Coûts humains de la dépendance au tabac [Human costs of tobacco dependence]

Human costs are an indicator of the value attributed to human burden related to diseases. The present paper summarizes a Swiss study. led by economists and physicians, which estimate the monetary value attributed by the general population regarding the consequences on quality of life of smoking related diseases. Such economic study may contribute to better understand smokers' concerns and beliefs and to improve effective strategies for smoking cessation in primary care.

Heterogeneity and event dependence in the analysis of sickness absence

Sickness absence (SA) is an important social, economic and public health issue. Identifying and understanding the determinants, whether biological, regulatory or, health services-related, of variability in SA duration is essential for better management of SA. The conditional frailty model (CFM) is useful when repeated SA events occur within the same individual, as it allows simultaneous analysis of event dependence and heterogeneity due to unknown, unmeasured, or unmeasurable factors. However, its use may encounter computational limitations when applied to very large data sets, as may frequently occur in the analysis of SA duration. To overcome the computational issue, we propose a Poisson-based conditional frailty model (CFPM) for repeated SA events that accounts for both event dependence and heterogeneity. To demonstrate the usefulness of the model proposed in the SA duration context, we used data from all non-work-related SA episodes that occurred in Catalonia (Spain) in 2007, initiated by either a diagnosis of neoplasm or mental and behavioral disorders. As expected, the CFPM results were very similar to those of the CFM for both diagnosis groups. The CPU time for the CFPM was substantially shorter than the CFM. The CFPM is an suitable alternative to the CFM in survival analysis with recurrent events,especially with large databases.

Cucumber seedling dependence on cotyledonary leaves for early growth

The objective of this work was to evaluate the dependence of cucumber (Cucumis sativus L.) seedlings on cotyledonary leaves for early growth and establishment. Sets of two uniform emerging seedlings were used to quantify the initial growth and dry matter accumulation, as well as the intensity and stage of cotyledon damage in seedling establishment and to determine cotyledon protein, amino acid and carbohydrate contributions to the growing seedling. Cucumber seedling establishment was found to be highly dependent on cotyledonary leaves. Root system establishment was highly dependent on the health of the aerial part. One cotyledon was enough to maintain aerial growth of seedlings after unfolding the first true leaf. Cucumber seedlings depended on both cotyledons to keep root system growth at least until leaf area was equivalent to cotyledon area. Covering one or both cotyledons of seedlings with one unfolded leaf increased carbohydrate content of uncovered cotyledon and leaves compared with control seedlings. Cucumber seedlings are highly dependent on cotyledonary leaves and aerial parts are less dependent than root system. Cotyledon damage at early stages of plant establishment would adversely impact crop yield by reducing plant density, an important yield component, or slowing down seedling growth and establishment.

Gender and socioeconomic disparities in BMI trajectories in the Seychelles using birth cohorts generated from serial population-based surveys.

ABSTRACT: BACKGROUND: The relationship between body mass index (BMI) and socioeconomic status (SES) tends to change over time and across populations. In this study, we examined, separately in men and women, whether the association between BMI and SES changed over successive birth cohorts in the Seychelles (Indian Ocean, African region). METHODS: We used data from all participants in three surveys conducted in 1989, 1994 and 2004 in independent random samples of the population aged 25-64 years in the Seychelles (N= 3'403). We used linear regression to model mean BMI according to age, cohort, SES and smoking status, allowing for a quadratic term for age to account for a curvilinear relation between BMI and age and interactions between SES and age and between SES and cohorts to test whether the relation between SES and BMI changed across subsequent cohorts. All analyses were performed separately in men and women. RESULTS: BMI increased with age in all birth cohorts. BMI was lower in men of low SES than high SES but was higher in women of low SES than high SES. In all SES categories, BMI increased over successive cohorts (1.24 kg/m2 in men and 1.51 kg/m2 for a 10-year increase in birth cohorts, p <0.001). The difference in BMI between men or women of high vs. low SES did not change significantly across successive cohorts (the interaction between SES and year of birth of cohort was statistically not significant). Smoking was associated with lower BMI in men and women (respectively -1.55 kg/m2 and 2.46 kg/m2, p <0.001). CONCLUSIONS: Although large differences exist between men and women, social patterning of BMI did not change significantly over successive cohorts in this population of a middle-income country in the African region.

Effects of trimethyltin (TMT) on glial and neuronal cells in aggregate cultures: dependence on the developmental stage.

Long-term effects of trimethyltin (TMT) applied at concentrations below the cytotoxic level were examined in three-dimensional cell cultures of fetal rat telencephalon using biochemical, immunochemical and morphological criteria. It was found that in immature cultures low concentrations of TMT (10(-8) M) specifically induced a gliotic response in astrocytes, with increased immunoreactivity for glial fibrillary acidic protein, and a greater number of astrocytic processes. Significant changes in oligodendrocytic and neuronal parameters were found only at 10(-6) M of TMT. In differentiated cultures, distinct changes in cell type-specific parameters occurred at 10(-6) M of TMT (the lowest effective concentration). In addition, different patterns of responses were found for astrocytes and oligodendrocytes, as compared to immature cultures. These results suggest that among neural cells, astroblasts are most sensitive to TMT, and that the glial responses to this neurotoxicant are development-dependent.

Treating tobacco use and dependence in clinical practice.

Physicians are in a unique position to advise smokers to quit by the ability to integrate the various aspects of nicotine dependence. This review provides an overview of the intervention strategies for smokers presented in a primary care setting. The strategies that are used for smoking cessation counselling differ according to the patient's readiness to quit. For smokers who do not intend to give up smoking, physicians should inform about tobacco use and the benefits of cessation. For smokers who are dissonant, physicians should use motivational strategies, such as discussing the barriers to successful cessation and their solutions. For smokers who are ready to quit, the physician should show strong support, help set a date to quit, prescribe pharmaceutical therapies for nicotine dependence, such as nicotine replacement therapy (i.e., gum, transdermal patch, nasal spray, mouth inhaler, lozenges, and micro and sublingual tablets) and/or bupropion (an atypical antidepressant thought to work by blocking the neural re-uptake of dopamine and/or noradrenaline), with instructions for use, and suggest behavioural strategies to prevent relapse. The efficacy of all of these pharmacotherapies is comparable, roughly doubling the cessation rates over control conditions.