Modeling resting-state functional networks when the cortex falls asleep: local and global changes.

The transition from wakefulness to sleep represents the most conspicuous change in behavior and the level of consciousness occurring in the healthy brain. It is accompanied by similarly conspicuous changes in neural dynamics, traditionally exemplified by the change from "desynchronized" electroencephalogram activity in wake to globally synchronized slow wave activity of early sleep. However, unit and local field recordings indicate that the transition is more gradual than it might appear: On one hand, local slow waves already appear during wake; on the other hand, slow sleep waves are only rarely global. Studies with functional magnetic resonance imaging also reveal changes in resting-state functional connectivity (FC) between wake and slow wave sleep. However, it remains unclear how resting-state networks may change during this transition period. Here, we employ large-scale modeling of the human cortico-cortical anatomical connectivity to evaluate changes in resting-state FC when the model "falls asleep" due to the progressive decrease in arousal-promoting neuromodulation. When cholinergic neuromodulation is parametrically decreased, local slow waves appear, while the overall organization of resting-state networks does not change. Furthermore, we show that these local slow waves are structured macroscopically in networks that resemble the resting-state networks. In contrast, when the neuromodulator decrease further to very low levels, slow waves become global and resting-state networks merge into a single undifferentiated, broadly synchronized network.

Adolescent's suicide attempts: populations at risk, vulnerability, and substance use.

Adolescence corresponds to a transition period that requires adaptation and change capacities and skills. Most young people succeed with this challenge, whereas a minority fail. In order to identify with the teenage culture, become autonomous, and differentiate from their parents, some adolescents choose to use drugs, beginning with the use of cigarettes, alcohol, cannabis, followed by other illicit drugs such as opiates and stimulants. A high proportion of these adolescents attempt suicide, which is the primary cause of death during adolescence in many European countries. Who are the "vulnerable" adolescents? What are the mechanisms that can explain the varieties of drug-use initiation or suicide attempts? Can "protective factors" be identified? What kind of strategies might be developed at a social and political level in order to prevent or to minimize drug abuse and suicide attempts, among other harmful behaviors? These issues will be discussed on the basis of the recent literature and in the light of a recent study carried out in the French-speaking part of Switzerland on large cohorts of adolescent drug users. Unresolved critical issues are noted and future needed research is suggested.

Permanent stallion contact hastens onset of mares' cyclicity after winter anoestrus

The species Equus caballus is characterized as a seasonal polyoestrous herd mammal, providing continuous interactions between stallions and mares in feral herds throughout the year. Under domesticated conditions mares and stallions are stabled and kept separated mostly due to hygienic and safety concerns. Managing mares through the spring transitional phase until they show fertile cycles represents a high multifactorial challenge for horse breeders and veterinarians. The goal of this study was to examine the influence of a permanent stallion contact on the onset of cyclicity in anoestrous mares in the transition period.

3D seismic facies characterization and geological patterns recognition (Australian North West Shelf)

EXECUTIVE SUMMARY This PhD research, funded by the Swiss Sciences Foundation, is principally devoted to enhance the recognition, the visualisation and the characterization of geobodies through innovative 3D seismic approaches. A series of case studies from the Australian North West Shelf ensures the development of reproducible integrated 3D workflows and gives new insight into local and regional stratigraphic as well as structural issues. This project was initiated in year 2000 at the Geology and Palaeontology Institute of the University of Lausanne (Switzerland). Several collaborations ensured the improvement of technical approaches as well as the assessment of geological models. - Investigations into the Timor Sea structural style were carried out at the Tectonics Special Research Centre of the University of Western Australia and in collaboration with Woodside Energy in Perth. - Seismic analysis and attributes classification approach were initiated with Schlumberger Oilfield Australia in Perth; assessments and enhancements of the integrated seismic approaches benefited from collaborations with scientists from Schlumberger Stavanger Research (Norway). Adapting and refining from "linear" exploration techniques, a conceptual "helical" 3D seismic approach has been developed. In order to investigate specific geological issues this approach, integrating seismic attributes and visualisation tools, has been refined and adjusted leading to the development of two specific workflows: - A stratigraphic workflow focused on the recognition of geobodies and the characterization of depositional systems. Additionally, it can support the modelling of the subsidence and incidentally the constraint of the hydrocarbon maturity of a given area. - A structural workflow used to quickly and accurately define major and secondary fault systems. The integration of the 3D structural interpretation results ensures the analysis of the fault networks kinematics which can affect hydrocarbon trapping mechanisms. The application of these integrated workflows brings new insight into two complex settings on the Australian North West Shelf and ensures the definition of astonishing stratigraphic and structural outcomes. The stratigraphic workflow ensures the 3D characterization of the Late Palaeozoic glacial depositional system on the Mermaid Nose (Dampier Subbasin, Northern Carnarvon Basin) that presents similarities with the glacial facies along the Neotethys margin up to Oman (chapter 3.1). A subsidence model reveals the Phanerozoic geodynamic evolution of this area (chapter 3.2) and emphasizes two distinct mode of regional extension for the Palaeozoic (Neotethys opening) and Mesozoic (abyssal plains opening). The structural workflow is used for the definition of the structural evolution of the Laminaria High area (Bonaparte Basin). Following a regional structural characterization of the Timor Sea (chapter 4.1), a thorough analysis of the Mesozoic fault architecture reveals a local rotation of the stress field and the development of reverse structures (flower structures) in extensional setting, that form potential hydrocarbon traps (chapter 4.2). The definition of the complex Neogene structural architecture associated with the fault kinematic analysis and a plate flexure model (chapter 4.3) suggest that the Miocene to Pleistocene reactivation phases recorded at the Laminaria High most probably result from the oblique normal reactivation of the underlying Mesozoic fault planes. This episode is associated with the deformation of the subducting Australian plate. Based on these results three papers were published in international journals and two additional publications will be submitted. Additionally this research led to several communications in international conferences. Although the different workflows presented in this research have been primarily developed and used for the analysis of specific stratigraphic and structural geobodies on the Australian North West Shelf, similar integrated 3D seismic approaches will have applications to hydrocarbon exploration and production phases; for instance increasing the recognition of potential source rocks, secondary migration pathways, additional traps or reservoir breaching mechanisms. The new elements brought by this research further highlight that 3D seismic data contains a tremendous amount of hidden geological information waiting to be revealed and that will undoubtedly bring new insight into depositional systems, structural evolution and geohistory of the areas reputed being explored and constrained and other yet to be constrained. The further development of 3D texture attributes highlighting specific features of the seismic signal, the integration of quantitative analysis for stratigraphic and structural processes, the automation of the interpretation workflow as well as the formal definition of "seismo-morphologic" characteristics of a wide range of geobodies from various environments would represent challenging examples of continuation of this present research. The 21st century will most probably represent a transition period between fossil and other alternative energies. The next generation of seismic interpreters prospecting for hydrocarbon will undoubtedly face new challenges mostly due to the shortage of obvious and easy targets. They will probably have to keep on integrating techniques and geological processes in order to further capitalise the seismic data for new potentials definition. Imagination and creativity will most certainly be among the most important quality required from such geoscientists.

A multi-temporal approach to model endangered species distribution in Europe: the case of the Eurasian otter in Italy

We analysed the relationship between changes in land cover patterns and the Eurasian otter occurrence over the course of about 20 years (1985-2006) using multi-temporal Species Distribution Models (SDMs). The study area includes five river catchments covering most of the otter's Italian range. Land cover and topographic data were used as proxies of the ecological requirements of the otter within a 300-m buffer around river courses. We used species presence, pseudo-absence data, and environmental predictors to build past (1985) and current (2006) SDMs by applying an ensemble procedure through the BIOMOD modelling package. The performance of each model was evaluated by measuring the area under the curve (AUC) of the receiver-operating characteristic (ROC). Multi-temporal analyses of species distribution and land cover maps were performed by comparing the maps produced for 1985 and 2006. The ensemble procedure provided a good overall modelling accuracy, revealing that elevation and slope affected the otter's distribution in the past; in contrast, land cover predictors, such as cultivations and forests, were more important in the present period. During the transition period, 20.5% of the area became suitable, with 76% of the new otter presence data being located in these newly available areas. The multi-temporal analysis suggested that the quality of otter habitat improved in the last 20 years owing to the expansion of forests and to the reduction of cultivated fields in riparian belts. The evidence presented here stresses the great potential of riverine habitat restoration and environmental management for the future expansion of the otter in Italy

Spatial predictions of land-use transitions and associated threats to biodiversity: the case of forest regrowth in mountain grasslands

Question Can we predict where forest regrowth caused by abandonment of agricultural activities is likely to occur? Can we assess how it may conflict with grassland diversity hotspots? Location Western Swiss Alps (4003210m a.s.l.). Methods We used statistical models to predict the location of land abandonment by farmers that is followed by forest regrowth in semi-natural grasslands of the Western Swiss Alps. Six modelling methods (GAM, GBM, GLM, RF, MDA, MARS) allowing binomial distribution were tested on two successive transitions occurring between three time periods. Models were calibrated using data on land-use change occurring between 1979 and 1992 as response, and environmental, accessibility and socio-economic variables as predictors, and these were validated for their capacity to predict the changes observed from 1992 to 2004. Projected probabilities of land-use change from an ensemble forecast of the six models were combined with a model of plant species richness based on a field inventory, allowing identification of critical grassland areas for the preservation of biodiversity. Results Models calibrated over the first land-use transition period predicted the second transition with reasonable accuracy. Forest regrowth occurs where cultivation costs are high and yield potential is low, i.e. on steeper slopes and at higher elevations. Overlaying species richness with land-use change predictions, we identified priority areas for the management and conservation of biodiversity at intermediate elevations. Conclusions Combining land-use change and biodiversity projections, we propose applied management measures for targeted/identified locations to limit the loss of biodiversity that could otherwise occur through loss of open habitats. The same approach could be applied to other types of land-use changes occurring in other ecosystems.

The social transition of risk factors for cardiovascular disease in the African region: evidence from three cross-sectional surveys in the Seychelles.

OBJECTIVES: To examine the association between socioeconomic status (SES) and several cardiovascular disease risk factors (CVRFs) and to assess whether this association has changed over a 15-year observation period. METHODS: Three independent population-based surveys of CVRFs were conducted in representative samples of all adults aged 25-64 years in the Seychelles, a small island state located east to Kenya, in 1989 (N=1081), 1994 (N=1067) and 2004 (N=1255). RESULTS: Among men, current smoking and heavy drinking were more prevalent in the low versus the high SES group, and obesity was less prevalent. The socioeconomic gradient in diabetes reversed over the study period from lower prevalence in the low versus the high SES group to higher prevalence in the low SES group. Hypercholesterolemia was less prevalent in the low versus the high SES group in 1989 but the prevalence was similar in the two groups in 2004. Hypertension showed no consistent socioeconomic pattern. Among women, the SES gradient in smoking tended to reverse over time from lower prevalence in the low SES group to lower prevalence in the high SES group. Obesity and diabetes were more common in the low versus the high SES group over the study period. Heavy drinking, hypertension and hypercholesterolemia were not socially patterned among women. CONCLUSION: The prevalence of several CVRFs was higher in low versus high SES groups in a rapidly developing country in the African region, and an increase of the burden of these CVRFs in the most disadvantaged groups of the population was observed over the 15 years study period.

Transition to parenthood: The role of social interaction and endogenous networks

Empirical studies indicate that the transition to parenthood is influenced by an individual's peer group. To study the mechanisms creating interdepen- dencies across individuals' transition to parenthood and its timing we apply an agent-based simulation model. We build a one-sex model and provide agents with three different characteristics regarding age, intended education and parity. Agents endogenously form their network based on social closeness. Network members then may influence the agents' transition to higher parity levels. Our numerical simulations indicate that accounting for social inter- actions can explain the shift of first-birth probabilities in Austria over the period 1984 to 2004. Moreover, we apply our model to forecast age-specific fertility rates up to 2016.

Family interactions in IVF families: change over the transition to parenthood

Objective: This article presents a study of the change over time in the family interactions of couples who conceived through in-vitro fertilisation (IVF). Background: Observational methods are rarely used to study family interactions in families who used assisted reproductive techniques, but these methods are crucial for taking account of the communication that occurs in interactions with infants. Methods: Thirty-one couples expecting their first child were seen during the fifth month of pregnancy and when the child was nine months old. Family interactions were recorded in pre- and postnatal versions of the Lausanne Trilogue Play situation. Measures of marital satisfaction and parent-to-foetus/baby attachment or 'bonding' were also used to assess family relational dynamics. Results: Results showed that family alliance, marital satisfaction and parental attachment scores in the IVF sample were all similar to or higher than those in the reference sample during pregnancy. However, at nine months postnatally, the family alliance scores were lower. While marital satisfaction decreased over the period and parent-baby attachment increased, the family alliance scores were unstable, as no association was observed between the pre- and postnatal scores. In addition, neither prenatal marital satisfaction nor parent-foetus attachment predicted the postnatal family alliance. Conclusion: The change in the family alliance over the transition to parenthood appears to be specific to our IVF sample. Given that postnatal family functioning could not be predicted by prenatal family functioning, our observational data underline the importance of offering postnatal support to these families.

Aortic biological valve prosthesis in patients younger than 65 years of age: transition to a flexible age limit?

OBJECTIVES Guidelines proposed bioprosthesis implantation for aortic valve disease if the patients were at least 65 years old at the time of surgery, with a trend towards even younger patients in recent years. Considering the adverse effects of lifetime anticoagulation, new biological valves (less prone to degeneration) and new technologies may lead patients and surgeons to different choices. Therefore, it is interesting to analyse the results of aortic bioprosthetic valve replacement in patients aged <65 years at the time of surgery. METHODS From January 2000 to December 2010, 84 patients aged <65 years at the time of surgery had undergone an aortic bio-prosthetic valve replacement. A mid-term follow-up [(FU) mean FU time: 54.4 ± 39.2 months] was done in August 2011 in all patients (FU completeness: 100%). Results were compared with patients who had a mechanical prosthetic aortic valve replacement during the same period. RESULTS The reoperation rate for structural valve degeneration (SVD) of bioprostheses was 6% and occurred exclusively among patients <56 years. Contraindications for anticoagulation determined the choice of a bioprosthesis among 83% of these patients. The personal preference to avoid anticoagulation was the leading cause in 68% of the older patients (56-65 years). Neurological complications occurred more frequently in the mechanical control group. CONCLUSIONS Reoperations for SVD after bioprosthesis implantation occurred exclusively among younger patients (<56 years), not suitable for systemic anticoagulation. Previous studies, together with our experience, are in favour of an age limit between 56 and 60 years, taking into consideration alternative transcatheter approaches to SVD treatment.

Late careers and the transition to retirement in Switzerland

A substantial body of life-course research has considered occupational trajectories in Switzerland focusing either on early or middle adulthood careers. However, the issue of the last working period and the retirement transition is receiving increasing attention for several reasons: the permanence of low birth rates associated with an ageing population, a high proportion of active old workers, continuous changes in the timing of retirements, and active ageing policies aiming at keeping people working after the state pension age. Moving forward on this topic, the present doctoral thesis aimed to offer new insights on the dynamics of the final career phase and the transition to retirement in Switzerland through a life-course approach. Concerning the main results, this thesis provides consistent evidences on the great influence of longterm familial and employment trajectories as well as individual positional factors on (i) the vulnerability during the last working period, (ii) the timing of retirement, (iii) the voluntariness of late retirement, and (iv) the financial well-being of retirees. In this way, this thesis offers significant contributions to the life-course, gender, and social policy research focused on ageing processes. -- Un ensemble considérable de recherches sur les parcours de vie a examiné les trajectoires professionnelles en Suisse, en mettant l'accent sur la carrière professionnelle des jeunes et, plus tard, à l'âge adulte. Toutefois, l'étude de la fin de la carrière professionnelle (c'est-à-dire de 50 ans jusqu'à la retraite) reçoit une attention croissante pour plusieurs raisons: la persistance du faible taux de natalité associé à une population vieillissante, la forte proportion de travailleurs âgés actifs, des évolutions continues dans le moment du départ à la retraite, et des politiques visant à maintenir les personnes âgées au travail après l'âge légal de la retraite. Pour aller de l'avant sur ce sujet, la présente thèse de doctorat vise à offrir de nouvelles perspectives sur la fin de carrière et la transition à la retraite en Suisse, en mobilisant les outils de la sociologie des parcours de vie. En ce qui concerne les principaux résultats, cette thèse fournit des preuves cohérentes sur la grande influence des trajectoires professionnelles et familiales ainsi que des facteurs positionnels sur (i) la vulnérabilité au cours de la période de travail avant la retraite, (ii) le moment de départ à la retraite, (iii) le caractère volontaire de la retraite tardive, et (iv) le bien-être financier des retraités. Ainsi, cette thèse fournit d'importantes contributions à la recherche sur les parcours de vie, sur les étu es genre, et sur les politiques sociales, focalisées sur le processus de vieillissement.

The health of adolescents around a world in transition.

Since several years, the health of adolescents is on the agenda of ministers, decision makers and health professionals. Around the world, while there has been a steady decrease of the death rates among young children, this is not the case for young people. This is mainly linked with the fact that mortality and morbidity during this period of life is largely linked with non communicable diseases and conditions, including deaths from injuries, suicide, homicides and drug abuse. Unplanned pregnancies, illegal abortions, newly acquired HIV infections are also situations that have short and long term consequences. This paper reviews the epidemiological data pertaining to adolescent health and disease. It proposes evidence-informed avenues as how to address these issues in the field of health care (e.g. adolescent friendly services) and of prevention and health promotion. It also stresses the importance of creating safe environments for the development and well-being of young people and thus, of an interdisciplinary and inter sectorial approach to their complex health problems and challenges.

Challenge of transition in the socio-professional insertion of youngsters with neurodisabilities

Patients with neurodisabilities require early management, continuing into adulthood. Thus, transition services were implemented in hospitals. To have a better support when they enter into adult life, it is useful to know the problems that they could face. The aim of this study is to evaluate their activities and to assess their insertion problems in the professional world. It is based on medical records of patients, aged 16 to 25 years, followed in the transition clinic of young adults in the Neurorehabilitation services of a tertiary centre. From 387 patients of the paediatric consultation, there are 267 patients (69%), included 224 with neurodevelopmental diseases and 43 with neuromuscular diseases. Nearly half of them (46.8%) were in a protected environment, 37.08% studied and 3.4% worked. Paradoxically, only 29.2% reported work problems. These results highlight the need to increase the integration of young adults with neuromotor disorders in the labor market.

Evolution of insulin sensitivity and its variability in out-of-hospital cardiac arrest (OHCA) patients treated with hypothermia.

INTRODUCTION: Therapeutic hypothermia (TH) is often used to treat out-of-hospital cardiac arrest (OHCA) patients who also often simultaneously receive insulin for stress-induced hyperglycaemia. However, the impact of TH on systemic metabolism and insulin resistance in critical illness is unknown. This study analyses the impact of TH on metabolism, including the evolution of insulin sensitivity (SI) and its variability, in patients with coma after OHCA. METHODS: This study uses a clinically validated, model-based measure of SI. Insulin sensitivity was identified hourly using retrospective data from 200 post-cardiac arrest patients (8,522 hours) treated with TH, shortly after admission to the intensive care unit (ICU). Blood glucose and body temperature readings were taken every one to two hours. Data were divided into three periods: 1) cool (T <35°C); 2) an idle period of two hours as normothermia was re-established; and 3) warm (T >37°C). A maximum of 24 hours each for the cool and warm periods was considered. The impact of each condition on SI is analysed per cohort and per patient for both level and hour-to-hour variability, between periods and in six-hour blocks. RESULTS: Cohort and per-patient median SI levels increase consistently by 35% to 70% and 26% to 59% (P <0.001) respectively from cool to warm. Conversely, cohort and per-patient SI variability decreased by 11.1% to 33.6% (P <0.001) for the first 12 hours of treatment. However, SI variability increases between the 18th and 30th hours over the cool to warm transition, before continuing to decrease afterward. CONCLUSIONS: OCHA patients treated with TH have significantly lower and more variable SI during the cool period, compared to the later warm period. As treatment continues, SI level rises, and variability decreases consistently except for a large, significant increase during the cool to warm transition. These results demonstrate increased resistance to insulin during mild induced hypothermia. Our study might have important implications for glycaemic control during targeted temperature management.

On the transition of genetic differentiation from isolation to panmixia: What we can learn from GST and D.

Population genetic differentiation characterizes the repartition of alleles among populations. It is commonly thought that genetic differentiation measures, such as GST and D, should be near zero when allele frequencies are close to their expected value in panmictic populations, and close to one when they are close to their expected value in isolated populations. To analyse those properties, we first derive analytically a reference function f of known parameters that describes how important features of genetic differentiation (e.g. gene diversity, proportion of private alleles, frequency of the most common allele) are close to their expected panmictic and isolation value. We find that the behaviour of function f differs according to three distinct mutation regimes defined by the scaled mutation rate and the number of populations. Then, we compare GST and D to f, and demonstrate that their signal of differentiation strongly depends on the mutation regime. In particular, we show that D captures well the variations of genetic diversity when mutation is weak, otherwise it overestimates it when panmixia is not met. GST detects population differentiation when mutation is intermediate but has a low sensitivity to the variations of genetic diversity when mutation is weak. When mutation is strong the domain of sensitivity of both measures are altered. Finally, we also point out the importance of the number of populations on genetic differentiation measures, and provide recommendations for the use of GST and D.