Effects of the social environment on the survival and fungal resistance of ant brood

The phenotype of social animals can be influenced by genetic, maternal and environmental effects, which include social interactions during development. In social insects, the social environment and genetic origin of brood can each influence a whole suite of traits, from individual size to caste differentiation. Here, we investigate to which degree the social environment during development affects the survival and fungal resistance of ant brood of known maternal origin. We manipulated one component of the social environment, the worker/brood ratio, of brood originating from single queens of Formica selysi. We monitored the survival of brood and measured the head size and ability to resist the entomopathogenic fungus Beauveria bassiana of the resulting callow workers. The worker/brood ratio and origin of eggs affected the survival and maturation time of the brood and the size of the resulting callow workers. The survival of the callow workers varied greatly according to their origin, both in controls and when challenged with B. bassiana. However, there was no interaction between the fungal challenge and either the worker/brood ratio or origin of eggs, suggesting that these factors did not affect parasite resistance in the conditions tested. Overall, the social conditions during brood rearing and the origin of eggs had a strong impact on brood traits that are important for fitness. We detected a surprisingly large amount of variation among queens in the survival of their brood reared in standard queenless conditions, which calls for further studies on genetic, maternal and social effects influencing brood development in the social insects.

Mainmise sur l'état social : mobilisation patronale et caisse de compensation en Suisse (1908-1960)

Qui sait qu'en Suisse, les associations patronales mettent en oeuvre l'Etat social ? Qui sait que associations organisent la majorité des caisses de compensation, dont la fonction principale est de collecter les cotisations et de payer les rentes de l'Assurance-vieillesse et survivants ? Qui connaît ces caisses par lesquelles transitent les milliards de l'Etat social ? L'objectif de cette thèse consiste à comprendre les raisons qui ont poussé le patronat helvétique à mettre en oeuvre les politiques de protection sociale, dont il a pourtant toujours essayé de limiter le développement. Résoudre ce paradoxe implique de se pencher sur près d'un siècle d'histoire mêlée du patronat et des politiques sociales. Ce travail retrace, sur la base d'archives privées et publiques souvent inédites, les raisons qui ont poussé les patrons à créer les premières caisses de compensation dans l'entre-deux-guerres, puis à imposer cette forme d'organisation pour l'aide aux soldats mobilisés (autour de 1940) et l'Assurance- vieillesse et survivants (autour de 1948). Il étudie également comment les associations patronales sont parvenues à défendre leurs caisses jusqu'à aujourd'hui, contre ceux qui dénonçaient l'irrationalité de l'existence d'une centaine de caisses de compensation publiques et privées concurrentes pour mettre en oeuvre un seul système d'assurances sociales. Cette recherche amène deux grands résultats. D'une part, elle propose une histoire originale des politiques sociales en Suisse. Le prisme des caisses de compensation patronales contribue en effet à interroger notre compréhension de l'histoire des politiques de protection sociale, dans laquelle on sous-estime parfois l'importance des conflits pour fixer les frontières entre formes de protection publique et privée. D'autre part, ce travail présente une histoire inédite de l'action collective des patrons dans les régulations du travail au sens large. A travers les caisses de compensation, c'est en effet à réaliser une histoire de l'Union centrale des associations patronales suisses que je me suis aussi attelé. Faute de parvenir à empêcher tout développement des politiques sociales, les patrons ont fait en sorte d'acquérir sur ces politiques une forme de mainmise. Entre histoire des politiques sociales et histoire du patronat, ce travail tente d'expliquer comment les caisses de compensation y ont contribué. Who knows that, in Switzerland, employers' associations implement the best known policies constituting the welfare state? Who knows that the equalization funds, (Caisses de compensation / Ausgleichskassen), organized by employers' associations or by the Swiss Cantons, are responsible for pooling payroll deductions and for paying benefits of the Swiss public pay-as-you-go, old-age insurance and many other branches of the welfare policies? Who knows these caisses de compensation that channel the monies dedicated to the financing of the Welfare state ? The main objective of this research is to understand the reasons why Swiss employers do implement such welfare policies that they usually reject for political reasons. In order to solve this puzzle, this research investigates half of a century of the connected histories of welfare policies and employers' collective action. It also investigates, based on public and private archive records, how employers founded the first caisses in the Interwar period, and imposed them to organize the main developments of the Welfare state during the Second World War. The research also underlines how employers defended their caisses de compensation against those questioning the rationality of this fragmented system aiming to implement one single set of public welfare through one hundred competing private and public caisses de compensation. This research highlights two main results. On the one hand, it helps to improve our understanding of the history of the welfare policies in Switzerland. Underlining the role of the caisses de compensation helps to highlight the importance of the interplay of public and private actors regarding social polices. On the other hand, this research charts a pioneering history of Swiss' employers' collective action regarding labor issues. Because they could not prevent all public welfare policy, employers achieved a form of stranglehold (mainmise) on the welfare State. Halfway between social policy and employers' associations' history, this research try to reveal how their caisses de compensation helped them in this objective.

Prognostic value of serial blood S100B determinations in stage IIB-III melanoma patients: a corollary study to EORTC trial 18952.

S100B is a prognostic factor for melanoma as elevated levels correlate with disease progression and poor outcome. We determined its prognostic value based on updated information using serial determinations in stage IIb/III melanoma patients. 211 Patients who participated in the EORTC 18952 trial, evaluating efficacy of adjuvant intermediate doses of interferon α2b (IFN) versus observation, entered a corollary study. Over a period of 36 months, 918 serum samples were collected. The Cox time-dependent model was used to assess prognostic value of the latest (most recent) S100B determination. At first measurement, 178 patients had S100B values <0.2 μg/l and 33 ≥ 0.2 μg/l. Within the first group, 61 patients had, later on, an increased value of S100B (≥ 0.2 μg/l). An initial increased value of S100B, or during follow-up, was associated with worse distant metastasis-free survival (DMFS); hazard ratio (HR) of S100B ≥ 0.2 versus S100B < 0.2 was 5.57 (95% confidence interval (CI) 3.81-8.16), P < 0.0001, after adjustment for stage, number of lymph nodes and sex. In stage IIb patients, the HR adjusted for sex was 2.14 (95% CI 0.71, 6.42), whereas in stage III, the HR adjusted for stage, number of lymph nodes and sex was 6.76 (95% CI 4.50-10.16). Similar results were observed regarding overall survival (OS). Serial determination of S100B in stage IIb-III melanoma is a strong independent prognostic marker, even stronger compared to stage and number of positive lymph nodes. The prognostic impact of S100B ≥ 0.2 μg/l is more pronounced in stage III disease compared with stage IIb.

General practitioners can evaluate the material, social and health dimensions of patient social status

OBJECTIVE: To identify which physician and patient characteristics are associated with physicians' estimation of their patient social status.DESIGN: Cross-sectional ulticentric survey. SETTING: Fourty-seven primary care private offices in Western Switzerland. PARTICIPANTS: Random sample of 2030 patients ≥ 16, who encountered a general practitioner (GP) between September 2010 and February 2011. MAIN MEASURES: PRIMARY OUTCOME: patient social status perceived by GPs, using the MacArthur Scale of Subjective Social Status, ranging from the bottom (0) to the top (10) of the social scale.Secondary outcome: Difference between GP's evaluation and patient's own evaluation of their social status. Potential patient correlates: material and social deprivation using the DiPCare-Q, health status using the EQ-5D, sources of income, and level of education. GP characteristics: opinion regarding patients' deprivation and its influence on health and care. RESULTS: To evaluate patient social status, GPs considered the material, social, and health aspects of deprivation, along with education level, and amount and type of income. GPs declaring a frequent reflexive consideration of their own prejudice towards deprived patients, gave a higher estimation of patients' social status (+1.0, p = 0.002). Choosing a less costly treatment for deprived patients was associated with a lower estimation (-0.7, p = 0.002). GP's evaluation of patient social status was 0.5 point higher than the patient's own estimate (p<0.0001). CONCLUSIONS: GPs can perceive the various dimensions of patient social status, although heterogeneously, according partly to their own characteristics. Compared to patients' own evaluation, GPs overestimate patient social status.

Children in the welfare state. A social investment approach

Children occupy centre-stage in any new welfare equilibrium. Failure to support families may produce either of two undesirable scenarios. We shall see a society without children if motherhood remains incompatible with work. A new family policy needs to recognize that children are a collective asset and that the cost of having children is rising. The double challenge is to eliminate the constraints on having children in the first place, and to ensure that the children we have are ensured optimal opportunities. The simple reason why a new social contract is called for is that fertility and child quality combine both private utility and societal gains. And like no other epoch in the past, the societal gains are mounting all-the-while that families’ ability to produce these social gains is weakening.In the following 1 analyze the twin challenges of fertility and child development. I then examine which kind of policy mix will ensure both the socially desired level of fertility and investment in our children? The task is to identify a Paretian optimum that will maximize efficiency gains and social equity simultaneously.

Social Security in Theory and Practice (II): Efficiency Theories, Narrative Theories, and Implications for Reform

166 countries have some kind of public old age pension. What economic forces create and sustain old age Social Security as a public program? Mulligan and Sala-i-Martin (1999b) document several of the internationally and historically common features of social security programs, and explore "political" theories of Social Security. This paper discusses the "efficiency theories", which view creation of the SS program as a full of partial solution to some market failure. Efficiency explanations of social security include the "SS as welfare for the elderly" the "retirement increases productivity to optimally manage human capital externalities", "optimal retirement insurance", the "prodigal father problem", the "misguided Keynesian", the "optimal longevity insurance", the "government economizing transaction costs", and the "return on human capital investment". We also analyze four "narrative" theories of social security: the "chain letter theory", the "lump of labor theory", the "monopoly capitalism theory", and the "Sub-but-Nearly-Optimal policy response to private pensions theory". The political and efficiency explanations are compared with the international and historical facts and used to derive implications for replacing the typical pay-as-you-go system with a forced savings plan. Most of the explanations suggest that forced savings does not increase welfare, and may decrease it.

Optimal Contracts, Adverse Selection, and Social Preferences: An Experiment

It has long been standard in agency theory to search for incentive-compatible mechanisms on the assumption that people care only about their own material wealth. However, this assumption is clearly refuted by numerous experiments, and we feel that it may be useful to consider nonpecuniary utility in mechanism design and contract theory. Accordingly, we devise an experiment to explore optimal contracts in an adverse-selection context. A principal proposes one of three contract menus, each of which offers a choice of two incentive-compatible contracts, to two agents whose types are unknown to the principal. The agents know the set of possible menus, and choose to either accept one of the two contracts offered in the proposed menu or to reject the menu altogether; a rejection by either agent leads to lower (and equal) reservation payoffs for all parties. While all three possible menus favor the principal, they do so to varying degrees. We observe numerous rejections of the more lopsided menus, and approach an equilibrium where one of the more equitable contract menus (which one depends on the reservation payoffs) is proposed and agents accept a contract, selecting actions according to their types. Behavior is largely consistent with all recent models of social preferences, strongly suggesting there is value in considering nonpecuniary utility in agency theory.

Adaptation and the genetics of social behaviour.

In recent years much progress has been made towards understanding the selective forces involved in the evolution of social behaviour including conflicts over reproduction among group members. Here, I argue that an important additional step necessary for advancing our understanding of the resolution of potential conflicts within insect societies is to consider the genetics of the behaviours involved. First, I discuss how epigenetic modifications of behaviour may affect conflict resolution within groups. Second, I review known natural polymorphisms of social organization to demonstrate that a lack of consideration of the genetic mechanisms involved may lead to erroneous explanations of the adaptive significance of behaviour. Third, I suggest that, on the basis of recent genetic studies of sexual conflict in Drosophila, it is necessary to reconsider the possibility of within-group manipulation by means of chemical substances (i.e. pheromones). Fourth, I address the issue of direct versus indirect genetic effects, which is of particular importance for the study of behaviour in social groups. Fifth, I discuss the issue of how a genetic influence on dominance hierarchies and reproductive division of labour can have secondary effects, for example in the evolution of promiscuity. Finally, because the same sets of genes (e.g. those implicated in chemical signalling and the responses that are triggered) may be used even in species as divergent as ants, cooperative breeding birds and primates, an integration of genetic mechanisms into the field of social evolution may also provide unifying ideas.

Laboratory-based versus non-laboratory-based CVD risk analysis.

Commentaire de: Gaziano TA, Young CR, Fitzmaurice G, Atwood S, Gaziano JM. Laboratory-based versus non-laboratory-based method for assessment of cardiovascular disease risk: the NHANES I Follow-up Study cohort. Lancet. 2008;371(9616):923-31. PMID: 18342687

Acute complications of Crohn's disease: Entero-MDCT versus entero-MRI [B-598]

Purpose: To compare entero-MDCT with entero-MRI performed for suspicion of acute exacerbation of known Crohn's disease. Methods and Materials: Fifty-seven patients (mean age 33.5) with histologically proven Crohn's disease were prospectively included. They presented with clinical symptoms suggesting acute exacerbation to the emergency department. After oral administration of 1-2 l of 5% methylcellulosis (+syrup), entero-MDCT and entero- MRI were performed on each patient (mean delay 1 day). Three experienced radiologists blindly and independently evaluated each examination for technical quality, eight pathological CT features (bowel wall thickening, pathological wall enhancement, stenosis, lymphadenopathy, mesenteric haziness, intraperitoneal fluid, abscess, fistula) and final main diagnosis. Interobserver agreement kappa was calculated. Sensitivity and specificity resulted from comparison with the reference standard, consisting of operation (n= 30) and long-time follow-up in case of conservative treatment (n=27). Results: Entero-MDCT demonstrated considerably less artefacts than entero-MRI (p 0.0001). In 9 entero-MDCT/-MRI, no activity of Crohn's disease was seen, whereas in 48 entero-MDCT/-MRI active disease could be demonstrated, such as intraperitoneal abscesses (n=11), fistulas (n=13), stenoses (n=23), acute (n=15) or chronic (n=23) inflammation. Interobserver agreement of the three readers was not significantly different between entero-MDCT and -MRI, neither was sensitivity (range 60-89%) and specificity (range 75-100%) for each of the eight pathological features or for the main diagnosis. Conclusion: Entero-MRI is statistically of similar diagnostic value as entero-MDCT for acute complications of Crohn's disease. Therefore, entero-IRM, devoid of harmful irradiation, should become the preferred imaging modality, since we deal with young patients, very likely exposed to frequent imaging controls in the future.

The decision of an obese woman to have bariatric surgery: the social phenomenology

Objective To understand the process by which an obese woman decides to have bariatric surgery. Method A qualitative survey with a social phenomenology approach, carried out in 2012, with 12 women, using the phenomenological interview. Results A woman bases the decision to have the surgery on: the inappropriateness of her eating habits; a physical appearance that is incompatible with an appearance that is standardized by society; the social prejudice that she has to live with; the limitations imposed by obesity; and her lack of success with previous attempts to lose weight. Outcomes that she hopes for from the decision to have the surgery include: restoring her health; achieving social inclusion; and entering the labor market. Conclusion This study allows one to reflect that prescriptive actions do not give a satisfactory response to a complexity of the subjective questions involved in the decision to have surgery for obesity. For this, what is called for is a program of work based on an interdisciplinary approach, and training that gives value to the bio-psycho-social aspects involved in a decision in favor of surgical treatment.

Partitioning of reproduction in mother-daughter versus sibling associations : a test of optimal skew theory

A critical feature of cooperative animal societies is the reproductive skew, a shorthand term for the degree to which a dominant individual monopolizes overall reproduction in the group. Our theoretical analysis of the evolutionarily stable skew in matrifilial (i.e., mother-daughter) societies, in which relatednesses to offspring are asymmetrical, predicts that reproductive skews in such societies should tend to be greater than those of semisocial societies (i.e., societies composed of individuals of the same generation, such as siblings), in which relatednesses to offspring are symmetrical. Quantitative data on reproductive skews in semisocial and matrifilial associations within the same species for 17 eusocial Hymenoptera support this prediction. Likewise, a survey of reproductive partitioning within 20 vertebrate societies demonstrates that complete reproductive monopoly is more likely to occur in matrifilial than in semisocial societies, also as predicted by the optimal skew model.

The genetical theory of social behaviour.

We survey the population genetic basis of social evolution, using a logically consistent set of arguments to cover a wide range of biological scenarios. We start by reconsidering Hamilton's (Hamilton 1964 J. Theoret. Biol. 7, 1-16 (doi:10.1016/0022-5193(64)90038-4)) results for selection on a social trait under the assumptions of additive gene action, weak selection and constant environment and demography. This yields a prediction for the direction of allele frequency change in terms of phenotypic costs and benefits and genealogical concepts of relatedness, which holds for any frequency of the trait in the population, and provides the foundation for further developments and extensions. We then allow for any type of gene interaction within and between individuals, strong selection and fluctuating environments and demography, which may depend on the evolving trait itself. We reach three conclusions pertaining to selection on social behaviours under broad conditions. (i) Selection can be understood by focusing on a one-generation change in mean allele frequency, a computation which underpins the utility of reproductive value weights; (ii) in large populations under the assumptions of additive gene action and weak selection, this change is of constant sign for any allele frequency and is predicted by a phenotypic selection gradient; (iii) under the assumptions of trait substitution sequences, such phenotypic selection gradients suffice to characterize long-term multi-dimensional stochastic evolution, with almost no knowledge about the genetic details underlying the coevolving traits. Having such simple results about the effect of selection regardless of population structure and type of social interactions can help to delineate the common features of distinct biological processes. Finally, we clarify some persistent divergences within social evolution theory, with respect to exactness, synergies, maximization, dynamic sufficiency and the role of genetic arguments.

Two-sided learning in New Keynesian models: Dynamics, (lack of) convergence and the value of information

This paper investigates the role of learning by private agents and the central bank(two-sided learning) in a New Keynesian framework in which both sides of the economyhave asymmetric and imperfect knowledge about the true data generating process. Weassume that all agents employ the data that they observe (which may be distinct fordifferent sets of agents) to form beliefs about unknown aspects of the true model ofthe economy, use their beliefs to decide on actions, and revise these beliefs througha statistical learning algorithm as new information becomes available. We study theshort-run dynamics of our model and derive its policy recommendations, particularlywith respect to central bank communications. We demonstrate that two-sided learningcan generate substantial increases in volatility and persistence, and alter the behaviorof the variables in the model in a significant way. Our simulations do not convergeto a symmetric rational expectations equilibrium and we highlight one source thatinvalidates the convergence results of Marcet and Sargent (1989). Finally, we identifya novel aspect of central bank communication in models of learning: communicationcan be harmful if the central bank's model is substantially mis-specified.

Market versus limit orders in an imperfectly competitive security

This paper analyzes the choice between limit and market orders in animperfectly competitive noisy rational expectations economy. There is a uniqueinsider, who takes into account the effect their trading has on prices. If theinsider behaves as a price taker, she will choose market orders if her privateinformation is very precise and she will choose limit orders otherwise. On thecontrary, if the insider recognizes and exploits her ability to affect themarket price, her optimal choice is to place limit orders whatever the precisionof her private information.