Population genomics of eusocial insects: the costs of a vertebrate-like effective population size

The evolution of reproductive division of labour and social life in social insects has lead to the emergence of several life-history traits and adaptations typical of larger organisms: social insect colonies can reach masses of several kilograms, they start reproducing only when they are several years old, and can live for decades. These features and the monopolization of reproduction by only one or few individuals in a colony should affect molecular evolution by reducing the effective population size. We tested this prediction by analysing genome-wide patterns of coding sequence polymorphism and divergence in eusocial vs. noneusocial insects based on newly generated RNA-seq data. We report very low amounts of genetic polymorphism and an elevated ratio of nonsynonymous to synonymous changes - a marker of the effective population size - in four distinct species of eusocial insects, which were more similar to vertebrates than to solitary insects regarding molecular evolutionary processes. Moreover, the ratio of nonsynonymous to synonymous substitutions was positively correlated with the level of social complexity across ant species. These results are fully consistent with the hypothesis of a reduced effective population size and an increased genetic load in eusocial insects, indicating that the evolution of social life has important consequences at both the genomic and population levels.

Cefuroxime prophylaxis is effective in noninstrumented spine surgery : a double-blind, placebo-controlled study

Rapport de synthèse : Plusieurs investigateurs ont démontré que l'utilisation d'une antibiothérapie prophylactique lors d'interventions neurochirurgicales en terrain non infecté (chirurgie propre) réduisait le taux d'infection. Toutefois, ces taux d'infections sont très variables en fonction des types de chirurgie et de la durée des interventions. Les craniotomies, la mise en place ou le remplacement de shunt ventriculo-cardiaque, l'extirpation de méningiomes intracrâniens et les interventions d'une durée de plus de quatre heures sont grevées d'un taux d'infections post-opératoires plus élevé. Si une prophylaxie antibiotique est maintenant reconnue et utilisée dans ce type de chirurgie, il n'a jamais été démontré que cette pratique amène un bénéfice dans les cas de chirurgie pour hernie discale. Des études ont montré que de nombreux organismes potentiellement pathogènes pouvaient être collectés et cultivés à proximité voire dans le champ opératoire. Malgré ces observations, le taux d'infections post-opératoires reste peu important (entre 1-4% selon les centres). Il n'est actuellement pas possible de distinguer le rôle respectif d'une antibiothérapie prophylactique et des pratiques d'asepsie habituelles (y compris l'usage de solutions de rinçage antiseptiques) dans la faible incidence des infections post-opératoires en ce qui concerne la chirurgie des hernies discales. Lorsque des opérations de chirurgie dite «propre » sont grevées d'un taux de complications aussi bas, une prophylaxie antibiotique n'est généralement pas recommandée, en raison d'un rapport coût-bénéfice défavorable. Le but de cette étude est d'évaluer la nécessité d'une antibiothérapie prophylactique par une céphalosporine de seconde génération (cefuroxime 1,5 g intraveineuse) dans la prévention des infections post-opératoires au cours d'une chirurgie pour hernie discale. Il s'agit d'un essai clinique prospectif, contrôlé contre placebo en insu réciproque, à répartition aléatoire. L'étude a été conduite dans les services de neurochirurgie de l'Hôpital Universitaire de Genève et du Centre Hospitalier Universitaire Vaudois de Lausanne. L'ensemble des patients admis dans ces deux services pour une opération de hernie discale et ayant donné leur consentement ont été inclus dans l'étude qui s'est déroulé sur une période de 6 ans. Mille trois cent soixante-neuf patients opérés pour une hernie discale ont été inclus dans cet essai et 132 patients ont été exclus de l'analyse pour diverses raisons. Au total 1'237 patients ont été analysés, respectivement 613 et 624 patients dans le groupe cefuroxime et le groupe placebo. Les patients des deux groupes présentaient des caractéristiques identiques. Nous n'avons objectivé aucun effet secondaire indésirable attribuable à la cefuroxime ou au placebo. Huit (1.3%) patients du groupe cefuroxime et 18 patients (2.8%) du groupe placebo ont développé une infection du site opératoire (P=0.073). Neuf des patients infectés dans le groupe placebo présentaient une infection profonde du site opératoire (spondylodiscite, abcès épidural) et aucun dans le groupe cefuroxime (P<0.01). Tous les patients avec infection profonde du site opératoire ont été traités par antibiothérapie par voie intraveineuse pour au moins 4 semaines et il a été procédé à une reprise chirurgicale chez deux patients. Ces résultats montrent qu'il faut traiter 69 patients avec une antibiothérapie prophylactique de cefuroxime pour prévenir une infection du site opératoire. En conclusion, l'administration d'une dose de cefuroxime 1.5 g intraveineuse comme prophylaxie lors d'opération de hernie discale, permet de réduire significativement le risque d'infection profonde du site opératoire.

Effective corporate governance : experimental evidence on international auditors'judgments and the contribution of financial accounting education

1 Summary This dissertation deals with two major aspects of corporate governance that grew in importance during the last years: the internal audit function and financial accounting education. In three essays, I contribute to research on these topics which are embedded in the broader corporate governance literature. The first two essays consist of experimental investigations of internal auditors' judgments. They deal with two research issues for which accounting research lacks evidence: The effectiveness of internal controls and the potentially conflicting role of the internal audit function between management and the audit committee. The findings of the first two essays contribute to the literature on internal auditors' judgment and the role of the internal audit function as a major cornerstone of corporate governance. The third essay theoretically examines a broader issue but also relates to the overall research question of this dissertation: What contributes to effective corporate governance? This last essay takes the perspective that the root for quality corporate governance is appropriate financial accounting education. r develop a public interest approach to accounting education that contributes to the literature on adequate accounting education with respect to corporate governance and accounting harmonization. The increasing importance of both the internal audit function and accounting education for corporate governance can be explained by the same recent fundamental changes that still affect accounting research and practice. First, the Sarbanes-Oxley Act of 2002 (SOX, 2002) and the 8th EU Directive (EU, 2006) have led to a bigger role for the internal audit function in corporate governance. Their implications regarding the implementation of audit committees and their oversight over internal controls are extensive. As a consequence, the internal audit function has become increasingly important for corporate governance and serves a new master (i.e. the audit committee) within the company in addition to management. Second, the SOX (2002) and the 8th EU Directive introduced additional internal control mechanisms that are expected to contribute to the reliability of financial information. As a consequence, the internal audit function is expected to contribute to a greater extent to the reliability of financial statements. Therefore, effective internal control mechanisms that strengthen objective judgments and independence become important. This is especially true when external- auditors rely on the work of internal auditors in the context of the International Standard on Auditing (ISA) 610 and the equivalent US Statement on Auditing Standards (SAS) 65 (see IFAC, 2009 and AICPA, 1990). Third, the harmonization of international reporting standards is increasingly promoted by means of a principles-based approach. It is the leading approach since a study of the SEC (2003) that was required by the SOX (2002) in section 108(d) was in favor of this approach. As a result, the Financial Accounting Standards Board (FASB) and the International Accounting Standards Board (IASB) commit themselves to the development of compatible accounting standards based on a principles-based approach. Moreover, since the Norwalk Agreement of 2002, the two standard setters have developed exposure drafts for a common conceptual framework that will be the basis for accounting harmonization. The new .framework will be in favor of fair value measurement and accounting for real-world economic phenomena. These changes in terms of standard setting lead to a trend towards more professional judgment in the accounting process. They affect internal and external auditors, accountants, and managers in general. As a consequence, a new competency set for preparers and users of financial statements is required. The basil for this new competency set is adequate accounting education (Schipper, 2003). These three issues which affect corporate governance are the initial point of this dissertation and constitute its motivation. Two broad questions motivated a scientific examination in three essays: 1) What are major aspects to be examined regarding the new role of the internal audit function? 2) How should major changes in standard setting affect financial accounting education? The first question became apparent due to two published literature reviews by Gramling et al. (2004) and Cohen, Krishnamoorthy & Wright (2004). These studies raise various questions for future research that are still relevant and which motivate the first two essays of my dissertation. In the first essay, I focus on the role of the internal audit function as one cornerstone of corporate governance and its potentially conflicting role of serving both management and the audit committee (IIA, 2003). In an experimental study, I provide evidence on the challenges for internal auditors in their role as servant for two masters -the audit committee and management -and how this influences internal auditors' judgment (Gramling et al. 2004; Cohen, Krishnamoorthy & Wright, 2004). I ask if there is an expectation gap between what internal auditors should provide for corporate governance in theory compared to what internal auditors are able to provide in practice. In particular, I focus on the effect of serving two masters on the internal auditor's independence. I argue that independence is hardly achievable if the internal audit function serves two masters with conflicting priorities. The second essay provides evidence on the effectiveness of accountability as an internal control mechanism. In general, internal control mechanisms based on accountability were enforced by the SOX (2002) and the 8th EU Directive. Subsequently, many companies introduced sub-certification processes that should contribute to an objective judgment process. Thus, these mechanisms are important to strengthen the reliability of financial statements. Based on a need for evidence on the effectiveness of internal control mechanisms (Brennan & Solomon, 2008; Gramling et al. 2004; Cohen, Krishnamoorthy & Wright, 2004; Solomon & Trotman, 2003), I designed an experiment to examine the joint effect of accountability and obedience pressure in an internal audit setting. I argue that obedience pressure potentially can lead to a negative influence on accountants' objectivity (e.g. DeZoort & Lord, 1997) whereas accountability can mitigate this negative effect. My second main research question - How should major changes in standard setting affect financial accounting education? - is investigated in the third essay. It is motivated by the observation during my PhD that many conferences deal with the topic of accounting education but very little is published about what needs to be done. Moreover, the Endings in the first two essays of this thesis and their literature review suggest that financial accounting education can contribute significantly to quality corporate governance as argued elsewhere (Schipper, 2003; Boyce, 2004; Ghoshal, 2005). In the third essay of this thesis, I therefore focus on approaches to financial accounting education that account for the changes in standard setting and also contribute to corporate governance and accounting harmonization. I argue that the competency set that is required in practice changes due to major changes in standard setting. As the major contribution of the third article, I develop a public interest approach for financial accounting education. The major findings of this dissertation can be summarized as follows. The first essay provides evidence to an important research question raised by Gramling et al. (2004, p. 240): "If the audit committee and management have different visions for the corporate governance role of the IAF, which vision will dominate?" According to the results of the first essay, internal auditors do follow the priorities of either management or the audit committee based on the guidance provided by the Chief Audit executive. The study's results question whether the independence of the internal audit function is actually achievable. My findings contribute to research on internal auditors' judgment and the internal audit function's independence in the broader frame of corporate governance. The results are also important for practice because independence is a major justification for a positive contribution of the internal audit function to corporate governance. The major findings of the second essay indicate that the duty to sign work results - a means of holding people accountable -mitigates the negative effect of obedience pressure on reliability. Hence, I found evidence that control .mechanisms relying on certifications may enhance the reliability of financial information. These findings contribute to the literature on the effectiveness of internal control mechanisms. They are also important in the light of sub-certification processes that resulted from the Sarbanes-Oxley Act and the 8th EU Directive. The third essay contributes to the literature by developing a measurement framework that accounts for the consequences of major trends in standard setting. Moreovér, it shows how these trends affect the required .competency set of people dealing with accounting issues. Based on this work, my main contribution is the development of a public interest approach for the design of adequate financial accounting curricula. 2 Serving two masters: Experimental evidence on the independence of internal auditors Abstract Twenty nine internal auditors participated in a study that examines the independence of internal auditors in their potentially competing roles of serving two masters: the audit committee and management. Our main hypothesis suggests that internal auditors' independence is not achievable in an institutional setting in which internal auditors are accountable to two different parties with potentially differing priorities. We test our hypothesis in an experiment in which the treatment consisted of two different instructions of the Chief audit executive; one stressing the priority of management (cost reduction) and one stressing the priority of the audit committee (effectiveness). Internal auditors had to evaluate internal controls and their inherent costs of different processes which varied in their degree of task complexity. Our main results indicate that internal auditors' evaluation of the processes is significantly different when task complexity is high. Our findings suggest that internal auditors do follow the priorities of either management or the audit committee depending on the instructions of a superior internal auditor. The study's results question whether the independence of the internal audit function is actually achievable. With our findings, we contribute to research on internal auditors' judgment and the internal audit function's independence in the frame of corporate governance.

Bond strength tests of dental adhesive systems and their correlation with clinical results : a meta-analysis

OBJECTIVE: To evaluate the variability of bond strength test results of adhesive systems (AS) and to correlate the results with clinical parameters of clinical studies investigating cervical restorations. MATERIALS AND METHODS: Regarding the clinical studies, the internal database which had previously been used for a meta-analysis on cervical restorations was updated with clinical studies published between 2008 and 2012 by searching the PubMed and SCOPUS databases. PubMed and the International Association for Dental Research abstracts online were searched for laboratory studies on microtensile, macrotensile and macroshear bond strength tests. The inclusion criteria were (1) dentin, (2) testing of at least four adhesive systems, (3) same diameter of composite and (4) 24h of water storage prior to testing. The clinical outcome variables were retention loss, marginal discoloration, detectable margins, and a clinical index comprising the three parameters by weighing them. Linear mixed models which included a random study effect were calculated for both, the laboratory and the clinical studies. The variability was assessed by calculating a ratio of variances, dividing the variance among the estimated bonding effects obtained in the linear mixed models by the sum of all variance components estimated in these models. RESULTS: Thirty-two laboratory studies fulfilled the inclusion criteria comprising 183 experiments. Of those, 86 used the microtensile test evaluating 22 adhesive systems (AS). Twenty-seven used the macrotensile test with 17 AS, and 70 used the macroshear test with 24 AS. For 28 AS the results from clinical studies were available. Microtensile and macrotensile (Spearman rho=0.66, p=0.007) were moderately correlated and also microtensile and macroshear (Spearman rho=0.51, p=0.03) but not macroshear and macrotensile (Spearman rho=0.34, p=0.22). The effect of the adhesive system was significant for microtensile and macroshear (p<0.001) but not for macrotensile. The effect of the adhesive system could explain 36% of the variability of the microtensile test, 27% of the macrotensile and 33% of the macroshear test. For the clinical trials, about 49% of the variability of retained restorations could be explained by the adhesive system. With respect to the correlation between bond strength tests and clinical parameters, only a moderate correlation between micro- and macrotensile test results and marginal discoloration was demonstrated. However, no correlation between these tests and a retention loss or marginal integrity was shown. The correlation improved when more studies were included compared to assessing only one study. SIGNIFICANCE: The high variability of bond strength test results highlights the need to establish individual acceptance levels for a given test institute. The weak correlation of bond-strength test results with clinical parameters leads to the conclusion that one should not rely solely on bond strength tests to predict the clinical performance of an adhesive system but one should conduct other laboratory tests like tests on the marginal adaptation of fillings in extracted teeth and the retention loss of restorations in non-retentive cavities after artificial aging.

Is high dose rate brachytherapy reliable and effective treatment for prostate cancer patients? A review of the literature.

The intrinsic physical and radiobiological characteristics of High Dose Rate Brachytherapy (HDR-BT) are well suited to the treatment of prostate cancer. HDR-BT was initially used as a boost to external beam brachytherapy, but has subsequently been employed as the sole treatment, which is termed HDR monotherapy. This review summarizes the clinical outcomes and toxicity results of the principal studies and discusses the radiobiological basis supporting its use.

Stratégies de communication au service de la formation: quelques outils pratiques [Effective communication strategies to frame the trainer-trainee dialogue in the clinical setting].

Communication between trainer and trainee plays a central role in teaching and learning in the clinical environment. There are various strategies to frame the dialogue between trainee and trainer. These strategies allow trainers to be more effective in their supervision, which is important in our busy clinical environment. Communication strategies are well adapted to both in- and out-patient settings, to both under- and postgraduate contexts. This article presents three strategies that we think are particularly useful. They are meant to give feedback, to ask questions and to present a case.

E-cigarette use in young Swiss men : is vaping an effective way of reducing or quitting smoking ?

QUESTION UNDER STUDY: To test longitudinally differences in conventional cigarette use (cigarettes smoked, cessation, quit attempts) between vapers and nonvapers. METHODS: Fifteen months follow-up of a sample of 5 128 20-year-old Swiss men. The onset of conventional cigarette (CC) use among nonsmokers, and smoking cessation, quit attempts, changes in the number of CCs smoked among smokers at baseline were compared between vapers and nonvapers at follow-up, adjusted for nicotine dependence. RESULTS: Among baseline nonsmokers, vapers were more likely to start smoking at follow-up than nonvapers (odds ratio [OR] 6.02, 95% confidence interval [CI] 2.81, 12.88 for becoming occasional smokers, and OR = 12.69, 95% CI 4.00, 40.28 for becoming daily smokers). Vapers reported lower smoking cessation rates among occasional smokers at baseline (OR = 0.43 (0.19, 0.96); daily smokers: OR = 0.42 [0.15, 1.18]). Vapers compared with nonvapers were heavier CC users (62.53 vs 18.10 cigarettes per week, p <0.001) and had higher nicotine dependence levels (2.16 vs 0.75, p <0.001) at baseline. The number of CCs smoked increased between baseline and follow-up among occasional smokers (b = 6.06, 95% CI 4.44, 7.68) and decreased among daily smokers (b = -5.03, 95% CI -8.69, -1.38), but there were no differential changes between vapers and nonvapers. Vapers showed more quit attempts at follow-up compared with nonvapers for baseline occasional smokers (incidence rate ratio [IRR] 1.81, 95% CI 1.24, 2.64; daily smokers IRR 1.28, 95% CI 0.95, 1.73). CONCLUSIONS: We found no beneficial effects of vaping at follow-up for either smoking cessation or smoking reduction.

Is Transnational Private Regulation Potentially an Effective Means of Promoting Collective Industrial Relations?

This paper asks whether collective industrial relations can be promoted by means other than seeking change in public policy. Recent research points to the increasing significance of transnational private regulation (TPR) in developing economies. There is an emerging consensus that market incentives to improve wages and conditions of work can have a modest positive effect on measurable outcomes like hours of work, and health and safety. However, it appears that TPR has little impact on the capacity of workers to pursue such improvements for themselves via collective action. The paper takes a closer look at the potential of TPR to enhance worker voice and participation. It argues that this potential cannot be properly evaluated without understanding how local actors mobilise the social and political resources that TPR provides. The case studies presented show how different TPR schemes have been used by unions in Africa as a means to pursue the interests of members. The authors found that the scale of the impact of TPR in all of the contexts studied depended almost entirely on the existing capacities and resources of the unions involved. TPR led to the creation of collective industrial relations processes, or helped unions to ensure that certain enterprises participated in existing industrial relations processes, but did virtually nothing to enhance the political and organisational capacity of the unions to influence the outcomes of those processes in terms of wages and conditions of employment. The paper concludes that the potential of TPR to promote the emergence of collective industrial relations systems is very low.

L'échographie dans le dépistage du cancer du sein: un outil efficace dans un dépistage personnalisé [Ultrasound for Breast Cancer Screening: an Effective Tool in a Personalized Screening].

Screening mammography is the only imaging modality with proved decrease in breast cancer mortality. Ultrasound has been proposed as additional tool for screening. Controversies remain about the real value of sonography in this setting. In Caucasian women with dense breast, sonography improves significantly breast cancer detection, but also increases the false positive cases, biopsies and costs. A careful selection of women who may benefit from additional screening with sonography is mandatory.

CHARACTERISING THE EOS SLOT-SCANNING SYSTEM WITH THE EFFECTIVE DETECTIVE QUANTUM EFFICIENCY.

NlmCategory="UNASSIGNED">As opposed to the standard detective quantum efficiency (DQE), effective DQE (eDQE) is a figure of merit that allows comparing the performances of imaging systems in the presence of scatter rejection devices. The geometry of the EOS™ slot-scanning system is such that the detector is self-collimated and rejects scattered radiation. In this study, the EOS system was characterised using the eDQE in imaging conditions similar to those used in clinical practice: with phantoms of different widths placed in the X-ray beam, for various incident air kerma and tube voltages corresponding to the phantom thickness. Scatter fractions in EOS images were extremely low, around 2 % for all configurations. Maximum eDQE values spanned 9-14.8 % for a large range of air kerma at the detector plane from 0.01 to 1.34 µGy. These figures were obtained with non-optimised EOS setting but still over-performed most of the maximum eDQEs recently assessed for various computed radiology and digital radiology systems with antiscatter grids.