34 resultados para Laboratory work


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This study, conducted with a representative sample of employed and unemployed adults living in Switzerland (N = 2002), focuses on work conditions (in terms of professional insecurity and job demands), career adaptability, and professional and general well-being. Analyses of covariance highlighted that both unemployed and employed participants with low job insecurity reported higher scores on career adaptability and several dimensions (notably on control) than employed participants with high job insecurity. Moreover, structural equation modeling for employed participants showed that, independent of work conditions, adaptability resources were positively associated both with general and professional well-being. As expected professional outcomes were strongly related to job strain and professional insecurity, emphasizing the central role of the work environment. Finally, career adaptability partially mediated the relationship between job strain and professional insecurity, and the outcome well-being.

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Water movement in unsaturated soils gives rise to measurable electrical potential differences that are related to the flow direction and volumetric fluxes, as well as to the soil properties themselves. Laboratory and field data suggest that these so-called streaming potentials may be several orders of magnitudes larger than theoretical predictions that only consider the influence of the relative permeability and electrical conductivity on the self potential (SP) data. Recent work has improved predictions somewhat by considering how the volumetric excess charge in the pore space scales with the inverse of water saturation. We present a new theoretical approach that uses the flux-averaged excess charge, not the volumetric excess charge, to predict streaming potentials. We present relationships for how this effective excess charge varies with water saturation for typical soil properties using either the water retention or the relative permeability function. We find large differences between soil types and the predictions based on the relative permeability function display the best agreement with field data. The new relationships better explain laboratory data than previous work and allow us to predict the recorded magnitudes of the streaming potentials following a rainfall event in sandy loam, whereas previous models predict values that are three orders of magnitude too small. We suggest that the strong signals in unsaturated media can be used to gain information about fluxes (including very small ones related to film flow), but also to constrain the relative permeability function, the water retention curve, and the relative electrical conductivity function.

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Abstract (English)General backgroundMultisensory stimuli are easier to recognize, can improve learning and a processed faster compared to unisensory ones. As such, the ability an organism has to extract and synthesize relevant sensory inputs across multiple sensory modalities shapes his perception of and interaction with the environment. A major question in the scientific field is how the brain extracts and fuses relevant information to create a unified perceptual representation (but also how it segregates unrelated information). This fusion between the senses has been termed "multisensory integration", a notion that derives from seminal animal single-cell studies performed in the superior colliculus, a subcortical structure shown to create a multisensory output differing from the sum of its unisensory inputs. At the cortical level, integration of multisensory information is traditionally deferred to higher classical associative cortical regions within the frontal, temporal and parietal lobes, after extensive processing within the sensory-specific and segregated pathways. However, many anatomical, electrophysiological and neuroimaging findings now speak for multisensory convergence and interactions as a distributed process beginning much earlier than previously appreciated and within the initial stages of sensory processing.The work presented in this thesis is aimed at studying the neural basis and mechanisms of how the human brain combines sensory information between the senses of hearing and touch. Early latency non-linear auditory-somatosensory neural response interactions have been repeatedly observed in humans and non-human primates. Whether these early, low-level interactions are directly influencing behavioral outcomes remains an open question as they have been observed under diverse experimental circumstances such as anesthesia, passive stimulation, as well as speeded reaction time tasks. Under laboratory settings, it has been demonstrated that simple reaction times to auditory-somatosensory stimuli are facilitated over their unisensory counterparts both when delivered to the same spatial location or not, suggesting that audi- tory-somatosensory integration must occur in cerebral regions with large-scale spatial representations. However experiments that required the spatial processing of the stimuli have observed effects limited to spatially aligned conditions or varying depending on which body part was stimulated. Whether those divergences stem from task requirements and/or the need for spatial processing has not been firmly established.Hypotheses and experimental resultsIn a first study, we hypothesized that auditory-somatosensory early non-linear multisensory neural response interactions are relevant to behavior. Performing a median split according to reaction time of a subset of behavioral and electroencephalographic data, we found that the earliest non-linear multisensory interactions measured within the EEG signal (i.e. between 40-83ms post-stimulus onset) were specific to fast reaction times indicating a direct correlation of early neural response interactions and behavior.In a second study, we hypothesized that the relevance of spatial information for task performance has an impact on behavioral measures of auditory-somatosensory integration. Across two psychophysical experiments we show that facilitated detection occurs even when attending to spatial information, with no modulation according to spatial alignment of the stimuli. On the other hand, discrimination performance with probes, quantified using sensitivity (d'), is impaired following multisensory trials in general and significantly more so following misaligned multisensory trials.In a third study, we hypothesized that behavioral improvements might vary depending which body part is stimulated. Preliminary results suggest a possible dissociation between behavioral improvements andERPs. RTs to multisensory stimuli were modulated by space only in the case when somatosensory stimuli were delivered to the neck whereas multisensory ERPs were modulated by spatial alignment for both types of somatosensory stimuli.ConclusionThis thesis provides insight into the functional role played by early, low-level multisensory interac-tions. Combining psychophysics and electrical neuroimaging techniques we demonstrate the behavioral re-levance of early and low-level interactions in the normal human system. Moreover, we show that these early interactions are hermetic to top-down influences on spatial processing suggesting their occurrence within cerebral regions having access to large-scale spatial representations. We finally highlight specific interactions between auditory space and somatosensory stimulation on different body parts. Gaining an in-depth understanding of how multisensory integration normally operates is of central importance as it will ultimately permit us to consider how the impaired brain could benefit from rehabilitation with multisensory stimula-Abstract (French)Background théoriqueDes stimuli multisensoriels sont plus faciles à reconnaître, peuvent améliorer l'apprentissage et sont traités plus rapidement comparé à des stimuli unisensoriels. Ainsi, la capacité qu'un organisme possède à extraire et à synthétiser avec ses différentes modalités sensorielles des inputs sensoriels pertinents, façonne sa perception et son interaction avec l'environnement. Une question majeure dans le domaine scientifique est comment le cerveau parvient à extraire et à fusionner des stimuli pour créer une représentation percep- tuelle cohérente (mais aussi comment il isole les stimuli sans rapport). Cette fusion entre les sens est appelée "intégration multisensorielle", une notion qui provient de travaux effectués dans le colliculus supérieur chez l'animal, une structure sous-corticale possédant des neurones produisant une sortie multisensorielle différant de la somme des entrées unisensorielles. Traditionnellement, l'intégration d'informations multisen- sorielles au niveau cortical est considérée comme se produisant tardivement dans les aires associatives supérieures dans les lobes frontaux, temporaux et pariétaux, suite à un traitement extensif au sein de régions unisensorielles primaires. Cependant, plusieurs découvertes anatomiques, électrophysiologiques et de neuroimageries remettent en question ce postulat, suggérant l'existence d'une convergence et d'interactions multisensorielles précoces.Les travaux présentés dans cette thèse sont destinés à mieux comprendre les bases neuronales et les mécanismes impliqués dans la combinaison d'informations sensorielles entre les sens de l'audition et du toucher chez l'homme. Des interactions neuronales non-linéaires précoces audio-somatosensorielles ont été observées à maintes reprises chez l'homme et le singe dans des circonstances aussi variées que sous anes- thésie, avec stimulation passive, et lors de tâches nécessitant un comportement (une détection simple de stimuli, par exemple). Ainsi, le rôle fonctionnel joué par ces interactions à une étape du traitement de l'information si précoce demeure une question ouverte. Il a également été démontré que les temps de réaction en réponse à des stimuli audio-somatosensoriels sont facilités par rapport à leurs homologues unisensoriels indépendamment de leur position spatiale. Ce résultat suggère que l'intégration audio- somatosensorielle se produit dans des régions cérébrales possédant des représentations spatiales à large échelle. Cependant, des expériences qui ont exigé un traitement spatial des stimuli ont produits des effets limités à des conditions où les stimuli multisensoriels étaient, alignés dans l'espace ou encore comme pouvant varier selon la partie de corps stimulée. Il n'a pas été établi à ce jour si ces divergences pourraient être dues aux contraintes liées à la tâche et/ou à la nécessité d'un traitement de l'information spatiale.Hypothèse et résultats expérimentauxDans une première étude, nous avons émis l'hypothèse que les interactions audio- somatosensorielles précoces sont pertinentes pour le comportement. En effectuant un partage des temps de réaction par rapport à la médiane d'un sous-ensemble de données comportementales et électroencépha- lographiques, nous avons constaté que les interactions multisensorielles qui se produisent à des latences précoces (entre 40-83ms) sont spécifique aux temps de réaction rapides indiquant une corrélation directe entre ces interactions neuronales précoces et le comportement.Dans une deuxième étude, nous avons émis l'hypothèse que si l'information spatiale devient perti-nente pour la tâche, elle pourrait exercer une influence sur des mesures comportementales de l'intégration audio-somatosensorielles. Dans deux expériences psychophysiques, nous montrons que même si les participants prêtent attention à l'information spatiale, une facilitation de la détection se produit et ce toujours indépendamment de la configuration spatiale des stimuli. Cependant, la performance de discrimination, quantifiée à l'aide d'un index de sensibilité (d') est altérée suite aux essais multisensoriels en général et de manière plus significative pour les essais multisensoriels non-alignés dans l'espace.Dans une troisième étude, nous avons émis l'hypothèse que des améliorations comportementales pourraient différer selon la partie du corps qui est stimulée (la main vs. la nuque). Des résultats préliminaires suggèrent une dissociation possible entre une facilitation comportementale et les potentiels évoqués. Les temps de réactions étaient influencés par la configuration spatiale uniquement dans le cas ou les stimuli somatosensoriels étaient sur la nuque alors que les potentiels évoqués étaient modulés par l'alignement spatial pour les deux types de stimuli somatosensorielles.ConclusionCette thèse apporte des éléments nouveaux concernant le rôle fonctionnel joué par les interactions multisensorielles précoces de bas niveau. En combinant la psychophysique et la neuroimagerie électrique, nous démontrons la pertinence comportementale des ces interactions dans le système humain normal. Par ailleurs, nous montrons que ces interactions précoces sont hermétiques aux influences dites «top-down» sur le traitement spatial suggérant leur occurrence dans des régions cérébrales ayant accès à des représentations spatiales de grande échelle. Nous soulignons enfin des interactions spécifiques entre l'espace auditif et la stimulation somatosensorielle sur différentes parties du corps. Approfondir la connaissance concernant les bases neuronales et les mécanismes impliqués dans l'intégration multisensorielle dans le système normale est d'une importance centrale car elle permettra d'examiner et de mieux comprendre comment le cerveau déficient pourrait bénéficier d'une réhabilitation avec la stimulation multisensorielle.

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ABSTRACT: Apprenticeship is a period of increased risk of developing work-related respiratory allergic diseases. There is a need for documents to provide appropriate professional advice to young adults aiming to reduce unsuitable job choices and prevent impairment from their careers. The present document is the result of a consensus reached by a panel of experts from European and non-European countries addressed to allergologists, pneumologists, occupational physicians, primary care physicians, and other specialists interested in this field, which aims to reduce work-related respiratory allergies (rhinoconjunctivitis and asthma) among allergic or nonallergic apprentices and other young adults entering the workforce. The main objective of the document is to issue consensus suggestions for good clinical practice based on existing scientific evidence and the expertise of a panel of physicians.

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Career adapt-ability has recently gained momentum as a psychosocial construct that not only has much to offer the field of career development, but also contributes to positive coping, adjustment and self-regulation through the four dimensions of concern, control, curiosity and confidence. The positive psychology movement, with concepts such as the orientations to happiness, explores the factors that contribute to human flourishing and optimum functioning. This research has two main contributions; 1) to validate a German version of the Career Adapt-Abilities Scale (CAAS), and 2) to extend the contribution of adapt-abilities to the field of work stress and explore its mediating capacity in the relation between orientations to happiness and work stress. We used a representative sample of the German-speaking Swiss working population including 1204 participants (49.8% women), aged between 26 and 56 (Mage = 42.04). Results indicated that the German version of the CAAS is valid, with overall high levels of model fit suggesting that the conceptual structure of career adapt-ability replicates well in this cultural context. Adapt-abilities showed a negative relationship to work stress, and a positive one with orientations to happiness. The engagement and pleasure scales of orientations to happiness also correlated negatively with work stress. Moreover, career adapt-ability mediates the relationship between orientations to happiness and work stress. In depth analysis of the mediating effect revealed that control is the only significant mediator. Thus control may be acting as a mechanism through which individuals attain their desired life at work subsequently contributing to reduced stress levels.

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Introduction: Low back pain is a common disorder touching up to 80% of the population, with redundancies of up to 70%. A small proportion would go on to develop chronic low back pain (LBP) with reduced work capacity and they would count for the majority of the costs. Up to day, a multi-disciplinary treatment program is one of the best approaches. In the program one of the mile-stones is restoration of function. The aim of this study was to follow patients, according to the endurance change after the program and its influence on workability during one year after inclusion in a such program. Method: Patients were following a multidisciplinary treatment for 3 weeks including physiotherapy, occupation measures combined with an educational program with behavioural and psychological interventions on an outpatient program. We studied the endurance with the help of the Bruce test, accomplished at the beginning and at the end of the program. On the other hand the patients filled out pain questionnaires and PACT score according their own impression on workability. Results: There were a clear relation between the increase in the cardiovascular endurance and the increased workability. Almost every patient presented an increase in the VO2 max, even though the workability did not follow. This increase were associated with a decrease in pain apprehension. Conclusion: A multidisciplinary treatment program, teaching the patients how to care with their pain and to accept it even if it persist is successful in lowering the global pain. If the program allows the patients to strengthen the endurance, the workability will increase in parallel. In this way the patients were able to reduce the consummation of medicaments and to increase the work capacity.

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OBJECTIVE: Ability to work and live independently is of particular concern for patients with Parkinson's disease (PD). We studied a series of PD patients able to work or live independently at baseline, and evaluated potential risk factors for two separate outcomes: loss of ability to work and loss of ability to live independently. METHODS: The series comprised 495 PD patients followed prospectively. Ability to work and ability to live independently were based on clinical interview and examination. Cox regression models adjusted for age and disease duration were used to evaluate associations of baseline characteristics with loss of ability to work and loss of ability to live independently. RESULTS: Higher UPDRS dyskinesia score, UPDRS instability score, UPDRS total score, Hoehn and Yahr stage, and presence of intellectual impairment at baseline were all associated with increased risk of future loss of ability to work and loss of ability to live independently (P ≤ 0.0033). Five years after initial visit, for patients ≤70 years of age with a disease duration ≤4 years at initial visit, 88% were still able to work and 90% to live independently. These estimates worsened as age and disease duration at initial visit increased; for patients >70 years of age with a disease duration >4 years, estimates at 5 years were 43% able to work and 57% able to live independently. CONCLUSIONS: The information provided in this study can offer useful information for PD patients in preparing for future ability to perform activities of daily living.

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PURPOSE: To highlight meningoencephalitis as a transient ischaemic attack (TIA) mimic and suggest clinical clues for differential diagnosis. METHODS: This was an observational study of consecutively admitted patients over a 9.75-year period presenting as TIAs at a stroke unit. RESULTS: A total of 790 patients with TIAs and seven with TIA-like symptoms but a final diagnosis of viral meningoencephalitis were recognised. The most frequent presentations of meningoencephalitis patients were acute sensory hemisyndrome (6) and cognitive deficits (5). Signs of meningeal irritation were minor or absent on presentation. Predominantly lymphocytic pleocytosis, hyperproteinorachia and a normal cerebrospinal fluid (CSF)/serum glucose index (in 5 out of 6 documented patients) were present. Meningeal thickening on a brain magnetic resonance imaging (MRI) scan was the only abnormal imaging finding. Six patients received initial vascular treatment; one thrombolysed. Finally, six patients were treated with antivirals and/or antibiotics. Although neither bacterial nor viral agents were identified on extensive testing, viral meningoencephalitis was the best explanation for all clinical and laboratory findings. CONCLUSIONS: Aseptic meningoencephalitis should be part of the differential diagnosis in patients presenting as TIA. The threshold for a lumbar puncture in such patients should be set individually and take into account the presence of mild meningeal symptoms, age and other risk factors for vascular disease, the results of brain imaging and the basic diagnostic work-up for a stroke source.

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PURPOSE: The aim of this study was to compare the mechanical external work (per kg) and pendular energy transduction at preferred walking speed (PWS) in obese versus normal body mass subjects to investigate whether obese adults adopt energy conserving gait mechanics. METHODS: The mechanical external work (Wext) and the fraction of mechanical energy recovered by the pendular mechanism (Rstep) were computed using kinematic data acquired by an optoelectronic system and were compared in 30 obese (OG; body mass index [BMI] = 39.6 +/- 0.6 kg m(-2); 29.5 +/- 1.3 yr) and 19 normal body mass adults (NG; BMI = 21.4 +/- 0.5 kg m(-2); 31.2 +/- 1.2 yr) walking at PWS. RESULTS: PWS was significantly lower in OG (1.18 +/- 0.02 m s(-1)) than in NG (1.33 +/- 0.02 m s(-1); P <or= 0.001). There was no significant difference in Wext per unit mass between groups (OG: 0.36 +/- 0.03 J kg(-1) m(-1); NG: 0.31 +/- 0.02 J kg(-1) m(-1); P = 0.12). Rstep was significantly lower in OG (68.4% +/- 2.0%) compared with NG (74.4% +/- 1.0%; P = 0.01). In OG only, Wext per unit mass was positively correlated with PWS (r = 0.57; P < 0.001). CONCLUSION: Obese adults do not appear to alter their gait to improve pendular energy transduction and may select slower PWS to reduce mechanical and metabolic work.

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ABSTRACT: BACKGROUND: Cardiovascular magnetic resonance (CMR) has favorable characteristics for diagnostic evaluation and risk stratification of patients with known or suspected CAD. CMR utilization in CAD detection is growing fast. However, data on its cost-effectiveness are scarce. The goal of this study is to compare the costs of two strategies for detection of significant coronary artery stenoses in patients with suspected coronary artery disease (CAD): 1) Performing CMR first to assess myocardial ischemia and/or infarct scar before referring positive patients (defined as presence of ischemia and/or infarct scar to coronary angiography (CXA) versus 2) a hypothetical CXA performed in all patients as a single test to detect CAD. METHODS: A subgroup of the European CMR pilot registry was used including 2,717 consecutive patients who underwent stress-CMR. From these patients, 21% were positive for CAD (ischemia and/or infarct scar), 73% negative, and 6% uncertain and underwent additional testing. The diagnostic costs were evaluated using invoicing costs of each test performed. Costs analysis was performed from a health care payer perspective in German, United Kingdom, Swiss, and United States health care settings. RESULTS: In the public sectors of the German, United Kingdom, and Swiss health care systems, cost savings from the CMR-driven strategy were 50%, 25% and 23%, respectively, versus outpatient CXA. If CXA was carried out as an inpatient procedure, cost savings were 46%, 50% and 48%, respectively. In the United States context, cost savings were 51% when compared with inpatient CXA, but higher for CMR by 8% versus outpatient CXA. CONCLUSION: This analysis suggests that from an economic perspective, the use of CMR should be encouraged as a management option for patients with suspected CAD.

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This book explores the perceptions of academic staff and representatives of institutional leadership about the changes in academic careers and academic work experienced in recent years. It emphasizes standardization and differentiation of academic career paths, impact of new forms of quality management on academic work, changes in recruitment, employment and working conditions, and academics' perceptions of their professional contexts. The book demonstrates a growing diversity within the academic profession and new professional roles inhabiting a space which is neither located in the core business of teaching and research nor at the top level management and leadership. The new higher education professionals tend to be important change agents within the higher education institutions not only fulfilling service and bridging functions but also streamlining academic work to make a contribution to the reputation and competitiveness of the institutions as a whole. Based on interviews with academic staff, this book explores the situation in eight European countries: Austria, Croatia, Finland, Germany, Ireland, Romania, and Switzerland.

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To determine the diagnostic accuracy of physicians' prior probability estimates of serious infection in critically ill neonates and children, we conducted a prospective cohort study in 2 intensive care units. Using available clinical, laboratory, and radiographic information, 27 physicians provided 2567 probability estimates for 347 patients (follow-up rate, 92%). The median probability estimate of infection increased from 0% (i.e., no antibiotic treatment or diagnostic work-up for sepsis), to 2% on the day preceding initiation of antibiotic therapy, to 20% at initiation of antibiotic treatment (P&lt;.001). At initiation of treatment, predictions discriminated well between episodes subsequently classified as proven infection and episodes ultimately judged unlikely to be infection (area under the curve, 0.88). Physicians also showed a good ability to predict blood culture-positive sepsis (area under the curve, 0.77). Treatment and testing thresholds were derived from the provided predictions and treatment rates. Physicians' prognoses regarding the presence of serious infection were remarkably precise. Studies investigating the value of new tests for diagnosis of sepsis should establish that they add incremental value to physicians' judgment.