Modified Corneal Collagen Crosslinking (CXL) Reduces Corneal Edema and Diurnal Visual Fluctuations in Fuchs' Dystrophy

Purpose: Crosslinking of corneal collagen with riboflavin and ultraviolet-A irradiation (CXL) induces crosslinks within and between collagen fibers. CXL increases corneal biomechanical and biochemical stability and is currently used clinically to treat keratectasia. CXL also significantly reduces the stromal swelling capacity. We investigated whether a modified CXL treatment protocol would be beneficial in early Fuchs' dystrophy with various degrees of corneal edema and diurnal variations in visual acuity. Methods: CXL was performed as published previously with the following modification: in cases where the stroma was thicker than 450 µm after abrasion and 30 minutes of instillation of isoosmolar riboflavin solution, glycerol 70% solution was applied every 5 seconds for two minutes, and central corneal thickness (CCT) was measured using ultrasound pachymetry. Glycerol 70% solution was administered repeatedly until the target corneal thickness of 370-430 µm was reached. During irradiation, CCT was monitored by ultrasound pachymetry every five minutes and glycerol 70% solution was applied, if necessary. Results: Three eyes in two patients were treated using the modified CXL protocol. Representative case: a 50-year-old woman with Fuchs' dystrophy and a history of 3 years of diurnal visual fluctuations was referred to us in March 2008. Preoperative best spectacle-corrected visual acuity (BSCVA) was 20/50. We performed modified CXL in the left eye. At one month after CXL, Scheimpflug analysis of CCT showed a reduction of more than 100 µm, and the Corneal Thickness Spatial Profile (CTSP) and Percentage of Increase in Thickness (PIT) showed a regularization of the "flattening" typical for Fuchs' dystrophy. Accordingly, diurnal analysis of corneal thickness showed a distinct postoperative reduction in CCT at all time points measured. At one month after CXL, the patient reported a reduction of diurnal visual fluctuations and we measured an increase in BSCVA to 20/32. The patient showed stable topographical and visual acuity at the three months follow-up. Conclusions: We saw a distinct reduction in CCT, an improvement of the corneal thickness spatial profile (CTSP) and an increase in BSCVA at one month after treatment, which remained stable at the three months follow-up. Patients with early Fuchs' dystrophy and disturbing diurnal visual fluctuations represent a novel application for CXL. Although CXL may not prevent the outcome of the dystrophy, it may increase the patients' visual comfort until keratoplasty becomes necessary.

Selective attention to emotional stimuli: What IQ and Openness do, and emotional intelligence does not

We examined how general intelligence, personality, and emotional intelligence-measured as an ability using the MSCEIT-predicted performance on a selective-attention task requiring participants to ignore distracting emotion information. We used a visual prime in which participants saw a pair of faces depicting emotions; their task was to focus on one of the faces (the target) while ignoring the other (the distractor). Next, participants categorized a string of letters (word or nonword), which was either congruent to the target or the distractor. The speed of response to categorizing the string was recorded. Given the emotional nature of the stimuli and the emotional information processing involved in the task, we were surprised to see that none of the MSCEIT branches predicted performance. However, general intelligence and openness to experience reduced response time.

Low dispersing species : population genetic processes in space and time : the genus "Trochulus" (Gastropoda: Hygromiidae) as a case study

RÉSUMÉ Une espèce est rarement composée d'une population unique. Parce que les individus ont des capacités de dispersion limitées et que les paysages sont des mosaïques d'habitats, la plupart des espèces sont plutôt composées de sous-populations connectées par la migration. Cette variation spatiale influence directement la distribution de la variabilité génétique dans et entre les populations. Durant ce travail, nous avons abordé certains des processus populationnels qui ont joué un rôle supposé dans l'apparition de nouvelles espèces au sein du genre Trochulus. Plus précisément, nous avons tenté d'évaluer les impacts respectifs de l'isolement passé (facteurs historiques) et présent (facteurs locaux). Nous avons d'abord pu montrer que les faibles capacités de dispersion des escargots terrestres ont directement influencé leur histoire évolutive à toutes les échelles spatiales et temporelles. En réduisant l'effet homogénéisant de la migration, une faible dispersion maintient dans les populations les traces génétiques d'évènements passés. A l'échelle de la distribution globale de Trochulus villosus, ces traces ont permis de reconstruire une histoire faite d'isolements et d'expansions de populations. En combinant des données génétiques avec une modélisation de la niche climatique passée, il a été possible de proposer un scénario significativement meilleur que toutes les hypothèses alternatives que nous avons testées. A l'échelle locale par contre, l'héritage historique est difficile à distinguer de la dynamique actuelle. Ce fut le cas des lignées mitochondriales du complexe sericeus-hispidus : les deux principales lignées étaient phylogénétiquement éloignées, avaient eu des démographies passées différentes et corrélaient avec des différences morphologiques. D'un autre côté, le flux de gène nucléaire était fort, contredisant l'idée de deux espèces cryptiques isolées reproductivement. Pour pouvoir conclure à la présence ou non de deux espèces, il nous a manqué des informations locales sur la dynamique des populations et les conditions écologiques que l'on trouve dans la région d'étude. Enfin, nous avons pu souligner que la connectivité entre populations d'escargots est soumise à la qualité des habitats et à leur organisation spatiale. Les escargots sont dépendants d'un habitat et s'y adaptent, comme l'indiquent la présence de «poils » uniquement sur la coquille d'espèces vivant dans des habitats humides ou la corrélation entre morphologie et habitat au sein du complexe sericeus-hispidus. Logiquement donc, les escargots migrent préférentiellement au travers d'habitats favorables comme l'a montré la réduction de flux de gènes au travers des prairies chez T. villosus (une espèce forestière). De ces données, nous pouvons supposer que les populations d'escargots en particulier, et des espèces à faible dispersion en général, ont de fortes chances d'être affectées par les changements climatiques, avec de probables implications pour leurs histoires évolutives. SUMMARY : Species rarely consists in a single population. Because individuals have limited dispersal abilities, because landscapes are habitat patchworks, most species are made of several subpopulations connected by migration. This spatial variation has consequences on the distribution of genetic diversity within and between populations, creating a structure among the populations. During the present work, we investigated some of the population processes assumed to have played an important role on the speciation within the genus Trochulus. More specifically, we questioned the respective impacts of past (historical factors) or present (local factors) population isolations. We first could show that the poor dispersal abilities of land snails have had profound impacts on their evolutionary histories at all spatial and temporal scales. Low dispersal maintains a strong signature of past events in the populations by minimising the homogenising effects of geneflow. At the scale of Trochulus villosus global distribution, they allowed to retrieve the detailed history of this species population isolations and expansions. Combining a large genetic dataset with paleo-climatic niche modelling ended up with a historical scenario significantly better than all traditional alternatives we tested. At local scale on the contrary, past events become difficult to tease apart from ongoing processes. This was the case for the divergent mitochondria) lineages within the sericeus-hispidus complex: the two principal lineages appeared to be phylogenetically distant, to have experienced different demographic histories and to correlate with morphological differences. On the other hand, nuclear (present day) geneflow was high, contradicting the idea of two reproductively isolated cryptic species. Information on the local population dynamics and environmental conditions are lacking to be able to decide whether past isolation has indeed resulted here in new species. Finally, we emphasised the importance of the habitat types present in a landscape as well as their spatial organisation for the population connectivity of land snails. These species are tightly dependent on a habitat and adapt to it as shown by thé occurrence of hair-like structures only in species living in humid environments or by the correlation between shell morphology and habitat in the sericeus-hispidus complex. As a result, land snails preferentially migrate through favourable habitats: Trochulus villosus, a forest species, had its geneflow significantly reduced across meadows. From these data, we can hypothesise that the populations of land snails in particular and of low dispersing species in general are likely to be strongly affected by the ongoing climate changes, with potential major consequences on their evolutionary histories.

RECHERCHE TRANSLATIONNELLE EN NEUROSCIENCES PSYCHIATRIQUES: DE L'ANIMAL MODELE DE SCHIZOPHRENIE A LA DETECTION D'UNE DESORIENTATION SPATIALE, PRATIQUE OU SYMBOLIQUE CHEZ DES PATIENTS

La modélisation, chez l'animal, de maladies psychiatriques telles que la schizophrénie repose sur différentes démarches visant à induire des perturbations cérébrales similaires à celles observées dans la maladie. Nous avons cherché à étudier chez le rat les effets d'une diminution (50%) transitoire en glutathion (GSH) durant le développement (PND 5 à PND 16) à partir de l'implication, chez des adultes, des conséquences de cette perturbation dans des mécanismes fondamentaux de traitement de l'information sensorielle. Cette thèse évalue et documente les déficits de compétences de navigation spatiale dans ce modèle. Nous avons mis en évidence des effets comportementaux à partir de l'identification de différences particulières dans des tâches d'orientation: des difficultés, chez les rats ayant subi un déficit en GSH, à élaborer une représentation globale de l'environnement dans lequel ils se déplacent, difficultés compensées par une attention particulière aux détails visuels le composant. Cette stratégie réactive compensatoire est efficace lorsque les conditions permettent un ajustement continu aux repères visuels environnementaux. Elle ne permet cependant pas des prédictions et des attentes sur ce qui devrait être rencontré et perçu dans une certaine direction, dès qu'une partie des informations visuelles familières disparaît. Il faudrait pour cela une capacité fondée sur une représentation abstraite, à distance des modalités sensorielles qui en ont permis son élaboration. Notre thèse soutient que les déficits, supposés participer à l'émergence de certains symptômes de la maladie, auraient également des conséquences sur l'élaboration de la représentation spatiale nécessaire à des capacités d'orientation effectives et symboliques. - The study of a psychiatric disease such as schizophrenia in an animal model relies on different approaches attempting to replicate brain perturbations similar to those observed in the illness. In the present work, behavioural consequences of a functional deficit in brain connectivity and coordination were assessed in rats with a transitory glutathione (GSH) deficit induced during the postnatal development (PND 5-PND 16) with daily injections of BSO (1- buthionine-(S,R)- sulfoximine). We searched for a theoretical syndrome associating ecologically relevant behavioural adaptive deficits and resulting from the weakening of sensory integration processes. Our results revealed significant and specific deficit of BSO treated rats in spatial orientation tasks designed to test for cognitive mapping abilities. Treated rats behaved as if impaired in the proactive strategies supported by an abstract representation such as a cognitive map. In contrast their performances were preserved whenever the environmental conditions allowed for adaptative reactive strategies, an equivalent of the visual affordances described by Gibson (1958). This supports our thesis that BSO treated rats expressed difficulties in elaborating a global representation of the environment. This deficit was completely - or - partially compensated by the development of an increased attention to the environment's visual details. This compensatory reactive strategy requires a rich environment allowing for continuous adjustment to visual cues. However, such adjustment doesn't allow to predictions and expectancies about what should be met and perceived in a certain direction, when familiar visual spatial cues are missing. Such competencies require orientation based on the use of an abstract spatial representation, independent from the specific sensory modalities that have participated to its elaboration. The impairment of BSO rats such spatial representation could result from a deficit in the integration and organization of perceptual information. Our model leads to the hypothesis that these fundamental deficits might account for certain symptoms of schizophrenia. They would also interfere with in the capacity to elaborate spatial representation necessary for optimal orientation in natural, artificial or symbolic environment.

Auditory-visual multisensory interactions in humans: timing, topography, directionality, and sources.

Current models of brain organization include multisensory interactions at early processing stages and within low-level, including primary, cortices. Embracing this model with regard to auditory-visual (AV) interactions in humans remains problematic. Controversy surrounds the application of an additive model to the analysis of event-related potentials (ERPs), and conventional ERP analysis methods have yielded discordant latencies of effects and permitted limited neurophysiologic interpretability. While hemodynamic imaging and transcranial magnetic stimulation studies provide general support for the above model, the precise timing, superadditive/subadditive directionality, topographic stability, and sources remain unresolved. We recorded ERPs in humans to attended, but task-irrelevant stimuli that did not require an overt motor response, thereby circumventing paradigmatic caveats. We applied novel ERP signal analysis methods to provide details concerning the likely bases of AV interactions. First, nonlinear interactions occur at 60-95 ms after stimulus and are the consequence of topographic, rather than pure strength, modulations in the ERP. AV stimuli engage distinct configurations of intracranial generators, rather than simply modulating the amplitude of unisensory responses. Second, source estimations (and statistical analyses thereof) identified primary visual, primary auditory, and posterior superior temporal regions as mediating these effects. Finally, scalar values of current densities in all of these regions exhibited functionally coupled, subadditive nonlinear effects, a pattern increasingly consistent with the mounting evidence in nonhuman primates. In these ways, we demonstrate how neurophysiologic bases of multisensory interactions can be noninvasively identified in humans, allowing for a synthesis across imaging methods on the one hand and species on the other.

Quantitative distribution of parvalbumin, calretinin, and calbindin D-28k immunoreactive neurons in the visual cortex of normal and Alzheimer cases.

The distribution of parvalbumin (PV), calretinin (CR), and calbindin (CB) immunoreactive neurons was studied with the help of an image analysis system (Vidas/Zeiss) in the primary visual area 17 and associative area 18 (Brodmann) of Alzheimer and control brains. In neither of these areas was there a significant difference between Alzheimer and control groups in the mean number of PV, CR, or CB immunoreactive neuronal profiles, counted in a cortical column going from pia to white matter. Significant differences in the mean densities (numbers per square millimeter of cortex) of PV, CR, and CB immunoreactive neuronal profiles were not observed either between groups or areas, but only between superficial, middle, and deep layers within areas 17 and 18. The optical density of the immunoreactive neuropil was also similar in Alzheimer and controls, correlating with the numerical density of immunoreactive profiles in superficial, middle, and deep layers. The frequency distribution of neuronal areas indicated significant differences between PV, CR, and CB immunoreactive neuronal profiles in both areas 17 and 18, with more large PV than CR and CB positive profiles. There were also significantly more small and less large PV and CR immunoreactive neuronal profiles in Alzheimer than in controls. Our data show that, although the brain pathology is moderate to severe, there is no prominent decrease of PV, CR and CB positive neurons in the visual cortex of Alzheimer brains, but only selective changes in neuronal perikarya.

Visual functions in the healthy and schizophrenic brain : from stimulus control to illusory perceptions using electrical neuroimaging

ABSTRACT (FRENCH)Ce travail de thèse basé sur le système visuel chez les sujets sains et chez les patients schizophrènes, s'articule autour de trois articles scientifiques publiés ou en cours de publication. Ces articles traitent des sujets suivants : le premier article présente une nouvelle méthode de traitement des composantes physiques des stimuli (luminance et fréquence spatiale). Le second article montre, à l'aide d'analyses de données EEG, un déficit de la voie magnocellulaire dans le traitement visuel des illusions chez les patients schizophrènes. Ceci est démontré par l'absence de modulation de la composante PI chez les patients schizophrènes contrairement aux sujets sains. Cette absence est induite par des stimuli de type illusion Kanizsa de différentes excentricités. Finalement, le troisième article, également à l'aide de méthodes de neuroimagerie électrique (EEG), montre que le traitement des contours illusoires se trouve dans le complexe latéro-occipital (LOC), à l'aide d'illusion « misaligned gratings ». De plus il révèle que les activités démontrées précédemment dans les aires visuelles primaires sont dues à des inférences « top- down ».Afin de permettre la compréhension de ces trois articles, l'introduction de ce manuscrit présente les concepts essentiels. De plus des méthodes d'analyses de temps-fréquence sont présentées. L'introduction est divisée en quatre parties : la première présente le système visuel depuis les cellules retino-corticales aux deux voix du traitement de l'information en passant par les régions composant le système visuel. La deuxième partie présente la schizophrénie par son diagnostic, ces déficits de bas niveau de traitement des stimuli visuel et ces déficits cognitifs. La troisième partie présente le traitement des contours illusoires et les trois modèles utilisés dans le dernier article. Finalement, les méthodes de traitement des données EEG seront explicitées, y compris les méthodes de temps-fréquences.Les résultats des trois articles sont présentés dans le chapitre éponyme (du même nom). De plus ce chapitre comprendra les résultats obtenus à l'aide des méthodes de temps-fréquenceFinalement, la discussion sera orientée selon trois axes : les méthodes de temps-fréquence ainsi qu'une proposition de traitement de ces données par une méthode statistique indépendante de la référence. La discussion du premier article en montrera la qualité du traitement de ces stimuli. La discussion des deux articles neurophysiologiques, proposera de nouvelles d'expériences afin d'affiner les résultats actuels sur les déficits des schizophrènes. Ceci pourrait permettre d'établir un marqueur biologique fiable de la schizophrénie.ABSTRACT (ENGLISH)This thesis focuses on the visual system in healthy subjects and schizophrenic patients. To address this research, advanced methods of analysis of electroencephalographic (EEG) data were used and developed. This manuscript is comprised of three scientific articles. The first article showed a novel method to control the physical features of visual stimuli (luminance and spatial frequencies). The second article showed, using electrical neuroimaging of EEG, a deficit in spatial processing associated with the dorsal pathway in chronic schizophrenic patients. This deficit was elicited by an absent modulation of the PI component in terms of response strength and topography as well as source estimations. This deficit was orthogonal to the preserved ability to process Kanizsa-type illusory contours. Finally, the third article resolved ongoing debates concerning the neural mechanism mediating illusory contour sensitivity by using electrical neuroimaging to show that the first differentiation of illusory contour presence vs. absence is localized within the lateral occipital complex. This effect was subsequent to modulations due to the orientation of misaligned grating stimuli. Collectively, these results support a model where effects in V1/V2 are mediated by "top-down" modulation from the LOC.To understand these three articles, the Introduction of this thesis presents the major concepts used in these articles. Additionally, a section is devoted to time-frequency analysis methods not presented in the articles themselves. The introduction is divided in four parts. The first part presents three aspects of the visual system: cellular, regional, and its functional interactions. The second part presents an overview of schizophrenia and its sensoiy-cognitive deficits. The third part presents an overview of illusory contour processing and the three models examined in the third article. Finally, advanced analysis methods for EEG are presented, including time- frequency methodology.The Introduction is followed by a synopsis of the main results in the articles as well as those obtained from the time-frequency analyses.Finally, the Discussion chapter is divided along three axes. The first axis discusses the time frequency analysis and proposes a novel statistical approach that is independent of the reference. The second axis contextualizes the first article and discusses the quality of the stimulus control and direction for further improvements. Finally, both neurophysiologic articles are contextualized by proposing future experiments and hypotheses that may serve to improve our understanding of schizophrenia on the one hand and visual functions more generally.

Multisensory facilitation of behavior in monkeys: effects of stimulus intensity.

Multisensory stimuli can improve performance, facilitating RTs on sensorimotor tasks. This benefit is referred to as the redundant signals effect (RSE) and can exceed predictions on the basis of probability summation, indicative of integrative processes. Although an RSE exceeding probability summation has been repeatedly observed in humans and nonprimate animals, there are scant and inconsistent data from nonhuman primates performing similar protocols. Rather, existing paradigms have instead focused on saccadic eye movements. Moreover, the extant results in monkeys leave unresolved how stimulus synchronicity and intensity impact performance. Two trained monkeys performed a simple detection task involving arm movements to auditory, visual, or synchronous auditory-visual multisensory pairs. RSEs in excess of predictions on the basis of probability summation were observed and thus forcibly follow from neural response interactions. Parametric variation of auditory stimulus intensity revealed that in both animals, RT facilitation was limited to situations where the auditory stimulus intensity was below or up to 20 dB above perceptual threshold, despite the visual stimulus always being suprathreshold. No RT facilitation or even behavioral costs were obtained with auditory intensities 30-40 dB above threshold. The present study demonstrates the feasibility and the suitability of behaving monkeys for investigating links between psychophysical and neurophysiologic instantiations of multisensory interactions.

Auditory motion affects visual biological motion processing.

The processing of biological motion is a critical, everyday task performed with remarkable efficiency by human sensory systems. Interest in this ability has focused to a large extent on biological motion processing in the visual modality (see, for example, Cutting, J. E., Moore, C., & Morrison, R. (1988). Masking the motions of human gait. Perception and Psychophysics, 44(4), 339-347). In naturalistic settings, however, it is often the case that biological motion is defined by input to more than one sensory modality. For this reason, here in a series of experiments we investigate behavioural correlates of multisensory, in particular audiovisual, integration in the processing of biological motion cues. More specifically, using a new psychophysical paradigm we investigate the effect of suprathreshold auditory motion on perceptions of visually defined biological motion. Unlike data from previous studies investigating audiovisual integration in linear motion processing [Meyer, G. F. & Wuerger, S. M. (2001). Cross-modal integration of auditory and visual motion signals. Neuroreport, 12(11), 2557-2560; Wuerger, S. M., Hofbauer, M., & Meyer, G. F. (2003). The integration of auditory and motion signals at threshold. Perception and Psychophysics, 65(8), 1188-1196; Alais, D. & Burr, D. (2004). No direction-specific bimodal facilitation for audiovisual motion detection. Cognitive Brain Research, 19, 185-194], we report the existence of direction-selective effects: relative to control (stationary) auditory conditions, auditory motion in the same direction as the visually defined biological motion target increased its detectability, whereas auditory motion in the opposite direction had the inverse effect. Our data suggest these effects do not arise through general shifts in visuo-spatial attention, but instead are a consequence of motion-sensitive, direction-tuned integration mechanisms that are, if not unique to biological visual motion, at least not common to all types of visual motion. Based on these data and evidence from neurophysiological and neuroimaging studies we discuss the neural mechanisms likely to underlie this effect.

Organizing principles across the senses

ABSTRACT This thesis is composed of two main parts. The first addressed the question of whether the auditory and somatosensory systems, like their visual counterpart, comprise parallel functional pathways for processing identity and spatial attributes (so-called `what' and `where' pathways, respectively). The second part examined the independence of control processes mediating task switching across 'what' and `where' pathways in the auditory and visual modalities. Concerning the first part, electrical neuroimaging of event-related potentials identified the spatio-temporal mechanisms subserving auditory (see Appendix, Study n°1) and vibrotactile (see Appendix, Study n°2) processing during two types of blocks of trials. `What' blocks varied stimuli in their frequency independently of their location.. `Where' blocks varied the same stimuli in their location independently of their frequency. Concerning the second part (see Appendix, Study n°3), a psychophysical task-switching paradigm was used to investigate the hypothesis that the efficacy of control processes depends on the extent of overlap between the neural circuitry mediating the different tasks at hand, such that more effective task preparation (and by extension smaller switch costs) is achieved when the anatomical/functional overlap of this circuitry is small. Performance costs associated with switching tasks and/or switching sensory modalities were measured. Tasks required the analysis of either the identity or spatial location of environmental objects (`what' and `where' tasks, respectively) that were presented either visually or acoustically on any given trial. Pretrial cues informed participants of the upcoming task, but not of the sensory modality. - In the audio-visual domain, the results showed that switch costs between tasks were significantly smaller when the sensory modality of the task switched versus when it repeated. In addition, switch costs between the senses were correlated only when the sensory modality of the task repeated across trials and not when it switched. The collective evidence not only supports the independence of control processes mediating task switching and modality switching, but also the hypothesis that switch costs reflect competitive interterence between neural circuits that in turn can be diminished when these neural circuits are distinct. - In the auditory and somatosensory domains, the findings show that a segregation of location vs. recognition information is observed across sensory systems and that these happen around 100ms for both sensory modalities. - Also, our results show that functionally specialized pathways for audition and somatosensation involve largely overlapping brain regions, i.e. posterior superior and middle temporal cortices and inferior parietal areas. Both these properties (synchrony of differential processing and overlapping brain regions) probably optimize the relationships across sensory modalities. - Therefore, these results may be indicative of a computationally advantageous organization for processing spatial anal identity information.

Combining molecular evolution and environmental genomics to unravel adaptive processes of MHC class IIB diversity in European minnows (Phoxinus phoxinus)

Host-pathogen interactions are a major evolutionary force promoting local adaptation. Genes of the major histocompatibility complex (MHC) represent unique candidates to investigate evolutionary processes driving local adaptation to parasite communities. The present study aimed at identifying the relative roles of neutral and adaptive processes driving the evolution of MHC class IIB (MHCIIB) genes in natural populations of European minnows (Phoxinus phoxinus). To this end, we isolated and genotyped exon 2 of two MHCIIB gene duplicates (DAB1 and DAB3) and 1665 amplified fragment length polymorphism (AFLP) markers in nine populations, and characterized local bacterial communities by 16S rDNA barcoding using 454 amplicon sequencing. Both MHCIIB loci exhibited signs of historical balancing selection. Whereas genetic differentiation exceeded that of neutral markers at both loci, the populations' genetic diversities were positively correlated with local pathogen diversities only at DAB3. Overall, our results suggest pathogen-mediated local adaptation in European minnows at both MHCIIB loci. While at DAB1 selection appears to favor different alleles among populations, this is only partially the case in DAB3, which appears to be locally adapted to pathogen communities in terms of genetic diversity. These results provide new insights into the importance of host-pathogen interactions in driving local adaptation in the European minnow, and highlight that the importance of adaptive processes driving MHCIIB gene evolution may differ among duplicates within species, presumably as a consequence of alternative selective regimes or different genomic context.

Testing new identity models and processes in French-speaking adolescents and emerging adults students

Developing a sense of identity is a crucial psychosocial task for young people. The purpose of this study was to evaluate identity development in French-speaking adolescents and emerging adults (in France and Switzerland) using a process-oriented model of identity formation including five dimensions (i.e., exploration in breadth, commitment making, exploration in depth, identification with commitment, and ruminative exploration). The study included participants from three different samples (total N = 2239, 66.7% women): two samples of emerging adult student and one sample of adolescents. Results confirmed the hypothesized five-factor dimensional model of identity in our three samples and provided evidence for convergent validity of the model. The results also indicated that exploration in depth might be subdivided in two aspects: a first form of exploration in depth leading to a better understanding and to an increase of the strength of current commitments and a second form of exploration in depth leading to a re-evaluation and a reconsideration of current commitments. Further, the identity status cluster solution that emerged is globally in line with previous literature (i.e., achievement, foreclosure, moratorium, carefree diffusion, diffused diffusion, undifferentiated). However, despite a structural similarity, we found variations in identity profiles because identity development is shaped by cultural context. These specific variations are discussed in light of social, educational and economic differences between France and the French-speaking part of Switzerland. Implications and suggestions for future research are offered.