Resistance to extreme strategies, rather than prosocial preferences, can explain human cooperation in public goods games.

The results of numerous economic games suggest that humans behave more cooperatively than would be expected if they were maximizing selfish interests. It has been argued that this is because individuals gain satisfaction from the success of others, and that such prosocial preferences require a novel evolutionary explanation. However, in previous games, imperfect behavior would automatically lead to an increase in cooperation, making it impossible to decouple any form of mistake or error from prosocial cooperative decisions. Here we empirically test between these alternatives by decoupling imperfect behavior from prosocial preferences in modified versions of the public goods game, in which individuals would maximize their selfish gain by completely (100%) cooperating. We found that, although this led to higher levels of cooperation, it did not lead to full cooperation, and individuals still perceived their group mates as competitors. This is inconsistent with either selfish or prosocial preferences, suggesting that the most parsimonious explanation is imperfect behavior triggered by psychological drives that can prevent both complete defection and complete cooperation. More generally, our results illustrate the caution that must be exercised when interpreting the evolutionary implications of economic experiments, especially the absolute level of cooperation in a particular treatment.

Metabolic predictors of obesity. Contribution of resting energy expenditure, thermic effect of food, and fuel utilization to four-year weight gain of post-obese and never-obese women.

This prospective study was designed to identify abnormalities of energy expenditure and fuel utilization which distinguish post-obese women from never-obese controls. 24 moderately obese, postmenopausal, nondiabetic women with a familial predisposition to obesity underwent assessments of body composition, fasting and postprandial energy expenditure, and fuel utilization in the obese state and after weight loss (mean 12.9 kg) to a post-obese, normal-weight state. The post-obese women were compared with 24 never-obese women of comparable age and body composition. Four years later, without intervention, body weight was reassessed in both groups. Results indicated that all parameters measured in the post-obese women were similar to the never-obese controls: mean resting energy expenditure, thermic effect of food, and fasting and postprandial substrate oxidation and insulin-glucose patterns. Four years later, post-obese women regained a mean of 10.9 kg while control subjects remained lean (mean gain 1.7 kg) (P < 0.001 between groups). Neither energy expenditure nor fuel oxidation correlated with 4-yr weight changes, whereas self-reported physical inactivity was associated with greater weight regain. The data suggest that weight gain in obesity-prone women may be due to maladaptive responses to the environment, such as physical inactivity or excess energy intake, rather than to reduced energy requirements.

Femmes et tabagisme: spécificités épidémiologiques et cliniques [Women and tobacco: epidemiological and clinical specificities]

Cigarette smoking amongst women is a major issue in daily clinical practice and in public health. Tobacco is the cause of gender specific diseases. From a psychosocial point of view, female smokers tend to be emotionally vulnerable and relationship sensitive. The risk of weight gain and depression must be anticipated and assessed throughout the smoking cessation process. Professionals involved in smoking cessation must be aware of these somatic and psychosocial specificities in order to be able to offer efficient smoking cessation treatments. Public health strategies must also be developed worldwide to control the expected dramatic impact of the female tobacco epidemic.

Expected impact of applying new 2013 AHA/ACC cholesterol guidelines criteria on the recommended lipid target achievement after acute coronary syndromes.

BACKGROUND: 2013 AHA/ACC guidelines on the treatment of cholesterol advised to tailor high-intensity statin after ACS, while previous ATP-III recommended titration of statin to reach low-density lipoprotein cholesterol (LDL-C) targets. We simulated the impact of this change of paradigm on the achievement of recommended targets. METHODS: Among a prospective cohort study of consecutive patients hospitalized for ACS from 2009 to 2012 at four Swiss university hospitals, we analyzed 1602 patients who survived one year after recruitment. Targets based on the previous guidelines approach was defined as (1) achievement of LDL-C target < 1.8 mmol/l, (2) reduction of LDL-C ≥ 50% or (3) intensification of statin in patients who did not reach LDL-C targets. Targets based on the 2013 AHA/ACC guidelines approach was defined as the maximization of statin therapy at high-intensity in patients aged ≤75 years and moderate- or high-intensity statin in patients >75 years. RESULTS: 1578 (99%) patients were prescribed statin at discharge, with 1120 (70%) at high-intensity. 1507 patients (94%) reported taking statin at one year, with 909 (57%) at high-intensity. Among 482 patients discharged with sub-maximal statin, intensification of statin was only observed in 109 patients (23%). 773 (47%) patients reached the previous LDL-C targets, while 1014 (63%) reached the 2013 AHA/ACC guidelines targetsone year after ACS (p value < 0.001). CONCLUSION: The application of the new 2013 AHA/ACC guidelines criteria would substantially increase the proportion of patients achieving recommended lipid targets one year after ACS. Clinical trial number, NCT01075868.

Cognitive behavioural therapy for weight gain associated with antipsychotic drugs

BACKGROUND: Overweight and obesity are common concerns in individuals with severe mental disorders. In particular, antipsychotic drugs (AP) frequently induce weight gain. This phenomenon lacks current management and no previous controlled studies seem to use cognitive therapy to modify eating and weight-related cognitions. Moreover, none of these studies considered binge eating or eating and weight-related cognitions as possible outcomes. AIM: The main aim of this study is to assess the effectivity of cognitive and behavioural treatment (CBT) on eating and weight-related cognitions, binge eating symptomatology and weight loss in patients who reported weight gain during AP treatment. METHOD: A randomized controlled study (12-week CBT vs. Brief Nutritional Education) was carried out on 61 patients treated with an antipsychotic drug who reported weight gain following treatment. Binge eating symptomatology, eating and weight-related cognitions, as well as weight and body mass index were assessed before treatment, at 12 weeks and at 24 weeks. RESULTS: The CBT group showed some improvement with respect to binge eating symptomatology and weight-related cognitions, whereas the control group did not. Weight loss occurred more progressively and was greater in the CBT group at 24 weeks. CONCLUSION: The proposed CBT treatment is particularly interesting for patients suffering from weight gain associated with antipsychotic treatment

Molecular Analysis of the PTEN Gene in a Choroidal Schwannoma in the Context of a Hamartomatous Syndrome

Purpose: To investigate the molecular involvement of PTEN, a tumor suppressor gene, in a case of cellular pigmented choroidal Schwannoma in a patient with hamartomatous syndrome due to heterozygous PTEN germline mutation. Methods: Histopathological, immunohistochemical, and electron microscopy analyses were performed by standard procedures. Paraffin-embedded samples of normal and tumor eye tissues were collected and DNA was extracted. A 145 bp region flanking the heterozygous c.406T>C mutation in exon 5 of PTEN was amplified by PCR and sequenced. To evaluate the allelic status of PTEN in the tumor sample, we cloned different PCR products in E. coli using a TA cloning procedure. Results: Histopathology demonstrated a posterior choroidal mass measuring 1.3 x 1.6 x 1.4 cm. The tumor was composed by fascicles of spindle cells with wavy cytoplasm. No Verrocay bodies could be identified. Scattered histiocytes with clear cytoplasm were present. By immunohistochemistry, the cells were expressing S100 and focally Melan A proteins. Pericellular type IV collagen could be demonstrated. Interlacing cytoplasmic processes covered by thick basement membrane could be found by electron microscopy as well as few premelanosomes. Moderate PTEN expression by immunohistochemistry was identified in some cells. As expected, the germline mutation could be detected by DNA sequencing in both the paraffin-embedded normal and tumor eye tissues. Analysis of 33 E. coli colonies bearing clones from the tumor eye tissue DNA surprisingly revealed that most of them contained the PTEN wild-type allele (29 vs. 4, Fisher's test p-value = 0.002). Conclusions: This is the first reported case of choroidal cellular Schwannoma arising in the context of a PTEN hamartomatous syndrome. Allelic analysis of PTEN in the tumor suggests a statistically-significant partial loss of heterozygozity in favor of the wild-type allele. Our findings are in clear contrast with what is usually observed in cancer tissues, for which mutated alleles of tumor suppressor genes are usually brought to homozygosity. Similar results were previously reported in human non-Hodgkin's lymphomas, displaying an overexpression of the wild-type form of the tumor suppressor gene p53. We are in the process of investigating additional DNA derived from other fresh and paraffin-embedded tissues from the patient, in order to gain insights on the molecular bases of PTEN involvement in this rare choroidal Schwannoma.

Increased fat oxidation in prepubertal obese children: a metabolic defense against further weight gain?

The purpose of this study was to measure postabsorptive fat oxidation at rest and to assess the association between fat mass and fat oxidation rate in prepubertal children, who were assigned to two groups: 35 obese children (weight, 44.5 +/- 9.7 kg; fat mass; 31.7 +/- 5.4%) and 37 nonobese children (weight, 30.8 +/- 6.8 kg; fat mass, 17.5 +/- 6.7%). Postabsorptive fat oxidation expressed in absolute value was significantly higher in obese than in nonobese children (31.4 +/- 9.7 mg/min vs 21.9 +/- 10.2 mg/min; p < 0.001) but not when adjusted for fat-free mass by analysis of covariance with fat-free mass as the covariate (28.2 +/- 10.6 mg/min vs 24.9 +/- 10.5 mg/min). In obese children and in the total group, fat mass and fat oxidation were significantly correlated (r = 0.65; p < 0.001). The slope of the relationship indicated that for each 10 kg additional fat mass, resting fat oxidation increased by 18 gm/day. We conclude that obese prepubertal children have a higher postabsorptive rate of fat oxidation than nonobese children. This metabolic process may favor the achievement of a new equilibrium in fat balance, opposing further adipose tissue gain.

Robust parametric indirect estimates of the expected cost of a hospital stay with covariates and censored data.

We consider the problem of estimating the mean hospital cost of stays of a class of patients (e.g., a diagnosis-related group) as a function of patient characteristics. The statistical analysis is complicated by the asymmetry of the cost distribution, the possibility of censoring on the cost variable, and the occurrence of outliers. These problems have often been treated separately in the literature, and a method offering a joint solution to all of them is still missing. Indirect procedures have been proposed, combining an estimate of the duration distribution with an estimate of the conditional cost for a given duration. We propose a parametric version of this approach, allowing for asymmetry and censoring in the cost distribution and providing a mean cost estimator that is robust in the presence of extreme values. In addition, the new method takes covariate information into account.

Industrial nanoparticle application : representative survey among Swiss companies shows low usage and basic protection means

Manufactured nanoparticles are introduced into industrial processes, but they are suspected to cause similar negative health effects as ambient particles. The poor knowledge about the scale of this introduction did not allow global risk analysis so far. In 2006 a targeted telephone survey among Swiss companies (1) showed the usage of nanoparticles in a few selected companies but did not provide data to extrapolate on the totality of the Swiss workforce. To gain this kind of information a layered representative questionnaire survey among 1'626 Swiss companies was conducted in 2007. Data was collected about the number of potentially exposed persons in the companies and their protection strategy. The response rate was 58.3%. An expected number of 586 companies (95%−confidence interval 145 to 1'027) was shown by this study to use nanoparticles in Switzerland. Estimated 1'309 (1'073 to 1'545) workers do their job in the same room as a nanoparticle application. Personal protection was shown to be the predominant type of protection means. Companies starting productions with nanomaterials need to consider incorporating protection measures into the plans. This will not only benefit the workers' health, but will also likely increase the competitiveness of the companies. Technical and organisational protection means are not only more cost−effective on the long term, but are also easier to control. Guidelines may have to be designed specifically for different industrial applications, including fields outside nanotechnology, and adapted to all sizes of companies.

Energy gap in the aetiology of body weight gain and obesity: a challenging concept with a complex evaluation and pitfalls.

The concept of energy gap(s) is useful for understanding the consequence of a small daily, weekly, or monthly positive energy balance and the inconspicuous shift in weight gain ultimately leading to overweight and obesity. Energy gap is a dynamic concept: an initial positive energy gap incurred via an increase in energy intake (or a decrease in physical activity) is not constant, may fade out with time if the initial conditions are maintained, and depends on the 'efficiency' with which the readjustment of the energy imbalance gap occurs with time. The metabolic response to an energy imbalance gap and the magnitude of the energy gap(s) can be estimated by at least two methods, i.e. i) assessment by longitudinal overfeeding studies, imposing (by design) an initial positive energy imbalance gap; ii) retrospective assessment based on epidemiological surveys, whereby the accumulated endogenous energy storage per unit of time is calculated from the change in body weight and body composition. In order to illustrate the difficulty of accurately assessing an energy gap we have used, as an illustrative example, a recent epidemiological study which tracked changes in total energy intake (estimated by gross food availability) and body weight over 3 decades in the US, combined with total energy expenditure prediction from body weight using doubly labelled water data. At the population level, the study attempted to assess the cause of the energy gap purported to be entirely due to increased food intake. Based on an estimate of change in energy intake judged to be more reliable (i.e. in the same study population) and together with calculations of simple energetic indices, our analysis suggests that conclusions about the fundamental causes of obesity development in a population (excess intake vs. low physical activity or both) is clouded by a high level of uncertainty.

Prise de poids et contraceptifs à progestatifs seuls: plus d'inquiétude que de preuves scientifiques. [Weight gain and progestin-only contraceptives: more concern than evidence].

Weight gain is a side effect often associated with progestin-only contraceptives. A recently published Cochrane review focuses on this issue that has been addressed in only few studies of good quality. Here we discuss the results of this review in the context of three clinical cases. With progestin-only contraceptives the weight gain is less than often thought, especially after six or twelve months of treatment. Some results are rather reassuring, especially those in obese women and during the post-partum period. This should help improve the compliance of women who fear gaining weight with this type of hormonal contraception.

A gain-of-function allele of TPC1 activates oxylipin biogenesis after leaf wounding in Arabidopsis.

Jasmonates, potent lipid mediators of defense gene expression in plants, are rapidly synthesized in response to wounding. These lipid mediators also stimulate their own production via a positive feedback circuit, which depends on both JA synthesis and JA signaling. To date, molecular components regulating the activation of jasmonate biogenesis and its feedback loop have been poorly characterized. We employed a genetic screen capable of detecting the misregulated activity of 13-lipoxygenase, which operates at the entry point of the jasmonate biosynthesis pathway. Leaf extracts from the Arabidopsis fou2 (fatty acid oxygenation upregulated 2) mutant displayed an increased capacity to catalyze the synthesis of lipoxygenase (LOX) metabolites. Quantitative oxylipin analysis identified less than twofold increased jasmonate levels in healthy fou2 leaves compared to wild-type; however, wounded fou2 leaves strongly increased jasmonate biogenesis compared to wounded wild-type. Furthermore, the plants displayed enhanced resistance to the fungus Botrytis cinerea. Higher than wild-type LOX activity and enhanced resistance in the fou2 mutant depend fully on a functional jasmonate response pathway. The fou2 mutant carries a missense mutation in the putative voltage sensor of the Two Pore Channel 1 gene (TPC1), which encodes a Ca(2+)-permeant non-selective cation channel. Patch-clamp analysis of fou2 vacuolar membranes showed faster time-dependent conductivity and activation of the mutated channel at lower membrane potentials than wild-type. The results indicate that cation fluxes exert strong control over the positive feedback loop whereby JA stimulates its own synthesis.

Impact of engineered nanomaterials on health : considerations for benefit-risk assessment

Nanotechnology encompasses the design, characterisation, production and application of materials and systems by controlling shape and size at the nanoscale (nanometres). Nanomaterials may differ from other materials because of their relatively large specific surface area, such that surface properties become particularly important. There has been rapid growth in investment in nanotechnology by both the public and private sectors worldwide. In the EU, nanotechnology is expected to become an important strategic contributor to achieving economic gain and societal and individual benefits. At the same time there is continuing scientific uncertainty and controversy about the safety of nanomaterials. It is important to ensure that timely policy development takes this into consideration. Uncertainty about safety may lead to polarised public debate and to business unwillingness to invest further. A clear regulatory framework to address potential health and environmental impacts, within the wider context of evaluating and communicating the benefit-risk balance, must be a core part of Europe's integrated efforts for nanotechnology innovation. While a number of studies have been carried out on the effect of environmental nanoparticles, e.g. from combustion processes, on human health, there is yet no generally acceptable paradigm for safety assessment of nanomaterials in consumer and other products. Therefore, a working group was established to consider issues for the possible impact of nanomaterials on human health focussing specifically on engineered nanomaterials. This represents the first joint initiative between EASAC and the Joint Research Centre of the European Commission. The working group was given the remit to describe the state of the art of benefits and potential risks, current methods for safety assessment, and to evaluate their relevance, identify knowledge gaps in studying the safety of current nanomaterials, and recommend on priorities for nanomaterial research and the regulatory framework. This report focuses on key principles and issues, cross-referencing other sources for detailed information, rather than attempting a comprehensive account of the science. The focus is on human health although environmental effects are also discussed when directly relevant to health