Rotation mentale et différences sexuelles: influence des axes directionnels extraits de l'environnement

Les tâches nécessitant des manipulations et des transformations de figures géométriques et de formes, comme les tâches de rotation mentale, donnent lieu à des différences de performance entre hommes et femmes qui restent intrigantes. Plusieurs hypothèses ont été proposées pour expliquer ces différences. La plus récurrente porte sur les différences de stratégie globale vs locale utilisées pour traiter l'information. Bien que cette conjecture soit intéressante, elle reste difficile à opérationnaliser car elle englobe tous les mécanismes cognitifs (acquisition, conservation et récupération de l'information). Ce travail prend la forme d'un retour aux sources dans la mesure où il se base sur des recherches anciennes qui ont montré que les hommes perçoivent significativement mieux que les femmes la verticale et l'horizontale. Il teste l'hypothèse selon laquelle les hommes, comparativement aux femmes, présentent une plus forte indépendance au champ perceptif visuel et sont donc plus susceptibles d'utiliser la verticalité et l'horizontalité pour résoudre une tâche de rotation mentale. Une première série d'expériences s'est penchée sur la perception spatiale pour évaluer son impact sur la résolution d'une tâche impliquant la rotation mentale. Les résultats ont montré que seuls les hommes se référaient à la verticalité et à l'horizontalité pour résoudre la tâche. Une seconde série d'expériences ont investigué l'effet de la présence, ou absence, d'axes directionnels directement liés à une tâche de rotation mentale. Elles ont été menées également en environnement réel afin d'évaluer comment le déplacement actif ou passif, correspondant à un changement de perspective en lieu et place d'une rotation mentale, module la performance des hommes et des femmes. Les résultats n'ont pas mis en évidence de différence sexuelle. Notre hypothèse est vérifiée puisque c'est uniquement lorsque la tâche ne présente pas d'axes orthogonaux évidents mais implicites que seuls les hommes, plus indépendants au champ perceptif visuel que les femmes, utilisent la perception de la verticalité et de l'horizontalité pour améliorer leur compétence en rotation mentale. -- Tasks that require manipulation and transformation of geometric shapes and forms, like tasks of mental rotation and give rise to differences in performance between men and women, remain intriguing. Several hypotheses have been proposed to explain these differences. The most recurring hypothesis addresses differences in global versus local strategies for processing information. While this conjecture is interesting, it remains difficult to study because it encompasses all the cognitive mechanisms (acquisition, retention and output). This work returns to the sources, which are based on earlier research that shows that men are significantly better than women at perceiving verticality and horizontality. It tests the hypothesis according to which men, as compared to women, exhibit a greater independence on the perceptive visual field, and therefore are more susceptible to utilizing the verticality and the horizontality to solve a mental rotation task. A first set of experiments examined spatial perception in order to assess its impact on the resolution of a task involving mental rotation. The results showed that only men referred to the verticality and the horizontality to solve the task. A second series of experiments investigated the effect of a presence, or absence of directional axes directed tied to the task of mental rotation. They were also conducted in a real world environment to evaluate how the active or passive displacement, corresponding to a change in perspective instead of a mental rotation, modulates the performance of men and women. The results did not show sex differences. Our hypothesis is verified: it is only when the task presents no obvious, but implicit orthogonal axes that men, who exhibit a greater independence on the perceptive visual field than women, use the perception of verticality and horizontality to improve their competence in mental rotation.

Maintenance and development of supplier relationships in an environment of irregular demand

The main target of the study was to find ideas for maintenance and development of supplier relations in irregular business environment. The other aim was to find out the suppliers’ opinions concerning the case company and the relationship between the companies. The study was conducted by using both qualitative and quantitative research methods. A mail survey was used to find out supplier opinions and an interview to find out suppliers’ ideas for relationship maintenance and development. It was found out that the use of relational elements is essential in the relationship maintenance in an irregular environment. In development of supplier relations the company should make better use of its suppliers’ potential, assure better flow of information and utilize the possibilities of Supplier Relationship Management.

Standardisation of elemental analytical techniques applied to provenance studies of archaeological ceramics: an inter laboratory calibration study

Chemical analysis is a well-established procedure for the provenancing of archaeological ceramics. Various analytical techniques are routinely used and large amounts of data have been accumulated so far in data banks. However, in order to exchange results obtained by different laboratories, the respective analytical procedures need to be tested in terms of their inter-comparability. In this study, the schemes of analysis used in four laboratories that are involved in archaeological pottery studies on a routine basis were compared. The techniques investigated were neutron activation analysis (NAA), X-ray fluorescence analysis (XRF), inductively coupled plasma optical emission spectrometry (ICP-OES) and inductively coupled plasma mass spectrometry (ICP-MS). For this comparison series of measurements on different geological standard reference materials (SRM) were carried out and the results were statistically evaluated. An attempt was also made towards the establishment of calibration factors between pairs of analytical setups in order to smooth the systematic differences among the results.

Täysmoduuli- ja semimoduulihyttien vertailu laivassa NB 1361

Tämän insinöörityön tavoitteena oli vertailla täysja semimoduulihyttien tarkoituksenmukaista käyttöä laivassa NB 1361. Moduulihyttejä on käytetty Helsingin telakalla jo pitkään, mutta enenevässä määrin halutaan siirtyä täysmoduulihyttien käyttöön. Nykyään kokoonpanotelakan on kehityttävä lisääntyvässä määrin siihen suuntaan, että telakalla asennetaan valmiit materiaalit, komponentit ja esivalmisteet. Laiva NB 1361:ssä telakan omilla hyttialueilla ei tarvitse käyttää semimoduulihyttejä asennusajan ja kustannusten säästämiseksi verrattuna täysmoduulihytteihin. Aker Yards Cabins saavuttaa omilla hyttialueillaan hyötyä käyttämällä semimoduulihyttejä oikeissa paikoissa verrattuna täysmoduulihytteihin. Vertailu osoittaa, että semimoduulihytti säästää aikaa ja kustannuksia, kun sitä käytetään oikeassa paikassa oikeaan aikaan. Täysmoduulihytti on sisustussuunnittelun ja tuotannonohjauksen lähtökohta laivan suunnittelun aloituksesta lähtien, mutta semimoduulihytin käyttöä tulee miettiä, kun muut työt kuin hyttiasennukset pitkittävät hyttialueiden valmistumista.

Virtausjakauman kokeellinen määritys levylämmönsiirtimissä

Diplomityön tavoitteena oli kokeellisen tutkimuksen keinoin selvittää juotettujen levylämmönsiirtimien levypakkarakenteessa virtausten käyttäytyminen ja jakautuminen sekä löytää ideoita ja kehitysehdotuksia levylämmönsiirtimen levypakan ja levyprofiilin kehittämiseksi. Kokeellinen tutkimus suoritettiin Oy Danfoss Ab LPM:n levylämmönsiirtimien tutkimuslaboratoriossa. Virtausjakauman tutkimusta varten suunniteltiin ja valittiin tutkimuslaitteisto, joka koostui termoelementtiantureista, tiedonkeruulaitteistosta sekä ohjelmistosta. Lämmönsiirtimistä mitattiin ensiö- ja toisiopuolen tilavuusvirrat ja painehäviöt sekä lämpötilat ennen ja jälkeen lämmönsiirtimen. Tutkimuslaitteiston avulla mitattiin lämpötiloja lämmönsiirtimen sisältä levyväleistä. Mittaukset suoritettiin neljällä levypakkarakenteella useilla massavirran arvoilla. Mittaustuloksista määritettiin levylämmönsiirtimien lämpö- ja virtaustekniset ominaisuudet nesteen Reynoldsin luvun funktiona sekä selvitettiin nesteen virtausjakaumat. Mittaustuloksien perusteella laskettuja virtausjakauman arvoja verrattiin teorian mukaan laskettuihin jakaumiin. Mitatuista siirtimistä lasketut massavirrat viittaavat siihen, että suurin osa nesteestä virtaa siirtimien keskeltä tai lähempää loppupäätä kuin alkupäästä. Teorian mukaan suurin nestemäärä virtaisi siirtimen alkupäästä vähentyen tasaisesti kohti levypakan loppupäätä. Teorian mukaiselle virtausjakaumalle ja lasketuille jakaumille ei löydetty yhteyttä. Tutkimuksessa havaittiin suuria, jopa yli 20 asteen, lämpötilaeroja levyväleistä ulostulevissa virtauksissa. Levyvälien virtauksen käyttäytymisen ja jakautumisen tutkiminen nähdäänkin levypakan pitkittäistä kehittämistä suurempana mielenkiinnon ja kehittämisen kohteena.

Identifying Pertinent Variables for Nonresponse Follow-Up Surveys : Lessons Learned from 4 Cases in Switzerland

All social surveys suffer from different types of errors, of which one of the most studied is non-response bias. Non-response bias is a systematic error that occurs because individuals differ in their accessibility and propensity to participate in a survey according to their own characteristics as well as those from the survey itself. The extent of the problem heavily depends on the correlation between response mechanisms and key survey variables. However, non-response bias is difficult to measure or to correct for due to the lack of relevant data about the whole target population or sample. In this paper, non-response follow-up surveys are considered as a possible source of information about non-respondents. Non-response follow-ups, however, suffer from two methodological issues: they themselves operate through a response mechanism that can cause potential non-response bias, and they pose a problem of comparability of measure, mostly because the survey design differs between main survey and non-response follow-up. In order to detect possible bias, the survey variables included in non-response surveys have to be related to the mechanism of participation, but not be sensitive to measurement effects due to the different designs. Based on accumulated experience of four similar non-response follow-ups, we studied the survey variables that fulfill these conditions. We differentiated socio-demographic variables that are measurement-invariant but have a lower correlation with non-response and variables that measure attitudes, such as trust, social participation, or integration in the public sphere, which are more sensitive to measurement effects but potentially more appropriate to account for the non-response mechanism. Our results show that education level, work status, and living alone, as well as political interest, satisfaction with democracy, and trust in institutions are pertinent variables to include in non-response follow-ups of general social surveys. - See more at: https://ojs.ub.uni-konstanz.de/srm/article/view/6138#sthash.u87EeaNG.dpuf

Les étudiant(e)s en médecine mènent une recherche dans La communauté [Male/female medical students conduct research in the community].

Pendant quatre semaines, les étudiant(e)s en médecine de 3e année de l'Université de Lausanne mènent une enquête dans la communauté sur le sujet de leur choix. L'objectif de ce module est de faire découvrir aux futurs médecins les déterminants non biomédicaux de la santé, de la maladie et de l'exercice de la médecine : les styles de vie, les facteurs psychosociaux et culturels, l'environnement, les décisions politiques, les contraintes économiques, les questions éthiques, etc. Par groupes de cinq, les étudiant(e)s commencent par définir une question de recherche originale et en explorent la littérature scientifique. Leur travail de recherche les amène à entrer en contact avec le réseau d'acteurs de la communauté concernés, professionnels ou associations de patients dont ils analysent les rôles et influences respectives. Chaque groupe est accompagné par un(e) tuteur(trice), enseignant(e) de la Faculté de biologie et de médecine de l'Université de Lausanne. Les étudiant(e)s présentent la synthèse de leurs travaux pendant un congrès de deux jours à la fin du module. Quatre travaux parmi les plus remarquables ont été choisis pour être publiés dans la Revue Médicale Suisse et Primary Care.

Redox Signaling by the RNA Polymerase III TFIIB-Related Factor Brf2.

TFIIB-related factor 2 (Brf2) is a member of the family of TFIIB-like core transcription factors. Brf2 recruits RNA polymerase (Pol) III to type III gene-external promoters, including the U6 spliceosomal RNA and selenocysteine tRNA genes. Found only in vertebrates, Brf2 has been linked to tumorigenesis but the underlying mechanisms remain elusive. We have solved crystal structures of a human Brf2-TBP complex bound to natural promoters, obtaining a detailed view of the molecular interactions occurring at Brf2-dependent Pol III promoters and highlighting the general structural and functional conservation of human Pol II and Pol III pre-initiation complexes. Surprisingly, our structural and functional studies unravel a Brf2 redox-sensing module capable of specifically regulating Pol III transcriptional output in living cells. Furthermore, we establish Brf2 as a central redox-sensing transcription factor involved in the oxidative stress pathway and provide a mechanistic model for Brf2 genetic activation in lung and breast cancer.

Evaluation of steroidomics by liquid chromatography hyphenated to mass spectrometry as a powerful analytical strategy for measuring human steroid perturbations.

This review presents the evolution of steroid analytical techniques, including gas chromatography coupled to mass spectrometry (GC-MS), immunoassay (IA) and targeted liquid chromatography coupled to mass spectrometry (LC-MS), and it evaluates the potential of extended steroid profiles by a metabolomics-based approach, namely steroidomics. Steroids regulate essential biological functions including growth and reproduction, and perturbations of the steroid homeostasis can generate serious physiological issues; therefore, specific and sensitive methods have been developed to measure steroid concentrations. GC-MS measuring several steroids simultaneously was considered the first historical standard method for analysis. Steroids were then quantified by immunoassay, allowing a higher throughput; however, major drawbacks included the measurement of a single compound instead of a panel and cross-reactivity reactions. Targeted LC-MS methods with selected reaction monitoring (SRM) were then introduced for quantifying a small steroid subset without the problems of cross-reactivity. The next step was the integration of metabolomic approaches in the context of steroid analyses. As metabolomics tends to identify and quantify all the metabolites (i.e., the metabolome) in a specific system, appropriate strategies were proposed for discovering new biomarkers. Steroidomics, defined as the untargeted analysis of the steroid content in a sample, was implemented in several fields, including doping analysis, clinical studies, in vivo or in vitro toxicology assays, and more. This review discusses the current analytical methods for assessing steroid changes and compares them to steroidomics. Steroids, their pathways, their implications in diseases and the biological matrices in which they are analysed will first be described. Then, the different analytical strategies will be presented with a focus on their ability to obtain relevant information on the steroid pattern. The future technical requirements for improving steroid analysis will also be presented.

Longitudinal monitoring of endogenous steroids in human serum by UHPLC-MS/MS as a tool to detect testosterone abuse in sports.

The detection of testosterone abuse in sports is routinely achieved through the 'steroidal module' of the Athlete Biological Passport by GC-MS(/MS) quantification of selected endogenous anabolic androgenic steroids (EAAS) from athletes' urines. To overcome some limitations of the "urinary steroid profile" such as the presence of confounding factors (ethnicity, enzyme polymorphism, bacterial contamination, and ethanol), ultrahigh performance liquid chromatography (UHPLC) measurements of blood concentrations of testosterone, its major metabolites, and precursors could represent an interesting and complementary strategy. In this work, two UHPLC-MS/MS methods were developed for the quantification of testosterone and related compounds in human serum, including major progestogens, corticoids, and estrogens. The validated methods were then used for the analyses of serum samples collected from 19 healthy male volunteers after oral and transdermal testosterone administration. Results from unsupervised multiway analysis allowed variations of target analytes to be assessed simultaneously over a 96-h time period. Except for alteration of concentration values due to the circadian rhythm, which concerns mainly corticosteroids, DHEA, and progesterone, significant variations linked to the oral and transdermal testosterone administration were observed for testosterone, DHT, and androstenedione. As a second step of analysis, the longitudinal monitoring of these biomarkers using intra-individual thresholds showed, in comparison to urine, significant improvements in the detection of testosterone administration, especially for volunteers with del/del genotype for phase II UGT2B17 enzyme, not sensitive to the main urinary marker, T/E ratio. A substantial extension of the detection window after transdermal testosterone administration was also observed in serum matrix. The longitudinal follow-up proposed in this study represents a first example of 'blood steroid profile' in doping control analysis, which can be proposed in the future as a complement to the 'urinary module' for improving steroid abuse detection capabilities.

L'informatique: un outil remarquable pour l'enseignement de la médecine interne générale [The informatics: a remarkable tool for teaching general internal medicine].

INTERMED training implies a three week course, integrated in the "primary care module" for medical students in the first master year at the school of medicine in Lausanne. INTERMED uses an innovative teaching method based on repetitive sequences of e-learning-based individual learning followed by collaborative learning activities in teams, named Team-based learning (TBL). The e-learning takes place in a web-based virtual learning environment using a series of interactive multimedia virtual patients. By using INTERMED students go through a complete medical encounter applying clinical reasoning and choosing the diagnostic and therapeutic approach. INTERMED offers an authentic experience in an engaging and safe environment where errors are allowed and without consequences.

Rapid analysis of multiclass antibiotic residues and some of their metabolites in hospital, urban wastewater and river water by ultra-highperformance liquid chromatography coupled to quadrupole-linear ion trap tandem mass spectrometry

The present work describes the development of a fast and robust analytical method for the determination of 53 antibiotic residues, covering various chemical groups and some of their metabolites, in environmental matrices that are considered important sources of antibiotic pollution, namely hospital and urban wastewaters, as well as in river waters. The method is based on automated off-line solid phase extraction (SPE) followed by ultra-high-performance liquid chromatography coupled to quadrupole linear ion trap tandem mass spectrometry (UHPLC–QqLIT). For unequivocal identification and confirmation, and in order to fulfill EU guidelines, two selected reaction monitoring (SRM) transitions per compound are monitored (the most intense one is used for quantification and the second one for confirmation). Quantification of target antibiotics is performed by the internal standard approach, using one isotopically labeled compound for each chemical group, in order to correct matrix effects. The main advantages of the method are automation and speed-up of sample preparation, by the reduction of extraction volumes for all matrices, the fast separation of a wide spectrum of antibiotics by using ultra-high-performance liquid chromatography, its sensitivity (limits of detection in the low ng/L range) and selectivity (due to the use of tandem mass spectrometry) The inclusion of β-lactam antibiotics (penicillins and cephalosporins), which are compounds difficult to analyze in multi-residue methods due to their instability in water matrices, and some antibiotics metabolites are other important benefits of the method developed. As part of the validation procedure, the method developed was applied to the analysis of antibiotics residues in hospital, urban influent and effluent wastewaters as well as in river water samples

Prospective motion correction with FID-triggered image navigators

In this work, we propose a method for prospective motion correction in MRI using a novel image navigator module, which is triggered by a free induction decay (FID) navigator. Only when motion occurs, the image navigator is run and new positional information is obtained through image registration. The image navigator was specifically designed to match the impact on the magnetization and the acoustic noise of the host sequence. This detection-correction scheme was implemented for an MP-RAGE sequence and 5 healthy volunteers were scanned at 3T while performing various head movements. The correction performance was demonstrated through automated brain segmentation and an image quality index whose results are sensitive to motion artifacts.

The role of renal biopsy in small renal masses.

Renal biopsy is being increasingly proposed as a diagnostic tool to characterize small renal masses (SRM). Indeed, the wide adoption of imaging in the diagnostic workup of many diseases had led to a substantial increased incidence of SRM (diameter ≤4 cm). While modern ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI) techniques have high sensitivity for detecting SRM, none is able to accurately and reliably characterize them in terms of histological features. This is currently of key importance in guiding clinical decision-making in some situations, and in these cases renal biopsy should be considered. In this review, we aim to summarize the technique, diagnostic performance, and predicting factors of nondiagnostic biopsy, as well as the future perspectives.