Domestication of different varieties in the cheese-making fungus Geotrichum candidum

Domestication is an excellent model for studying adaptation processes, involving recent adaptation and diversification, convergence following adaptation to similar conditions, as well as degeneration of unused functions. Geotrichum candidum is a fungus used for cheese making and is also found in other environments such as soil and plants. By analyzing whole-genome data from 98 strains, we found that all strains isolated from cheese formed a monophyletic clade. Within the cheese clade, we identified three genetically differentiated populations and we detected footprints of recombination and admixture. The genetic diversity in the cheese clade was similar as that in the wild clade, suggesting the lack of strong bottlenecks. Commercial starter strains were scattered across the cheese clade, thus not constituting a single clonal lineage. The cheese populations were phenotypically differentiated from other populations, with a slower growth on all media, even cheese, a prominent production of typical cheese volatiles and a lower proteolytic activity. One of the cheese clusters encompassed all soft goat cheese strains, suggesting an effect of cheese-making practices on differentiation. Another of the cheese populations seemed to represent a more advanced stage of domestication, with stronger phenotypic differentiation from the wild clade, harboring much lower genetic diversity, and phenotypes more typical of cheese fungi, with denser and fluffier colonies and a greater ability of excluding cheese spoiler fungi. Cheese populations lacked two beta lactamase-like genes present in the wild clade, involved in xenobiotic clearance, and displayed higher contents of transposable elements, likely due to relaxed selection. Our findings suggest the existence of genuine domestication in G. candidum, which led to diversification into different varieties with contrasted phenotypes. Some of the traits acquired by cheese strains indicate convergence with other, distantly related fungi used for cheese maturation

Subthalamic nucleus stimulation affects limbic and associative circuits: a PET study

Purpose Although high-frequency deep brain stimulation of the subthalamic nucleus (STN DBS) improves motor symptoms in advanced Parkinson's disease (PD), clinical studies have reported cognitive, motivational and emotional changes. These results suggest that the STN forms part of a broadly distributed neural network encompassing the associative and limbic circuits. We sought to pinpoint the cortical and subcortical brain areas modulated by STN DBS, in order to assess the STN's functional role and explain neuropsychological modifications following STN DBS in PD. Methods We studied resting state glucose metabolism in 20 PD patients before and after STN DBS and 13 age-matched healthy controls using 18F-FDG PET. We used statistical analysis (SPM2) first to compare pre-stimulation metabolism in PD patients with metabolism in healthy controls, then to study metabolic modifications in PD patients following STN DBS. Results The first analysis revealed no pre-stimulation metabolic abnormalities in associative or limbic circuitry. After STN DBS, metabolic modifications were found in several regions known for their involvement in the limbic and associative circuits. Conclusion These metabolic results confirm the STN's central role in associative and limbic basal ganglia circuits. They will provide information for working hypotheses for future studies investigating neuropsychological changes and metabolic modifications related to STN DBS, with a view to improving our knowledge of this structure's functional role

Le travail à temps partiel durant les études chez les élèves du secondaire : Impacts sur leur adaptation scolaire et psychosociale

Le travail à temps partiel (TTP) des adolescentes et adolescents durant les études est un phénomène social de plus en plus répandu en Amérique du Nord. Pourtant, que savons-nous de ses impacts, à court et à moyen termes, sur l’adaptation scolaire et psychosociale des élèves entre le milieu et la fin du secondaire? Dans le cadre d’une étude québécoise, des questionnaires standardisés ont été remplis par des élèves en troisième, quatrième et cinquième secondaire : tracas quotidiens (Plancherel et al., 1997), stratégies adaptatives (Frydenberg et al., 1993), problèmes psychopathologiques (Achenbach, 1991), estime de soi (Rosenberg, 1965), optimisme (Scheier et al., 1985), autonomie (Greenberger et al., 1974) et travail à temps partiel (adaptation du MÉQ, 1994). Les relevés de notes des élèves en mathématiques, en français ainsi que le relevé général furent également recueillis. Globalement, les résultats révèlent que le TTP durant les études s’avère un facteur de risque pour l’adaptation scolaire des élèves en troisième et en quatrième secondaire travaillant plus de onze heures par semaine, ce qui n’est pas le cas de ceux appartenant à la même catégorie en cinquième secondaire. Par contre, aucun coût réel associé au TTP durant les études n’a été observé sur l’adaptation psychosociale des adolescentes et adolescents et cela, aux trois cycles scolaires. D’autres analyses indiquent qu’un TTP effectué en troisième secondaire ne permet pas de prédire la sévérité des tracas quotidiens, les ressources personnelles, les résultats scolaires et les comportements intériorisés et extériorisés mesurés en quatrième secondaire, exception faite des stratégies adaptatives productives et sociales évaluées en cinquième secondaire. La conclusion porte sur l’importance de renforcer les facteurs de protection de chaque élève afin de mieux faire face au tandem travail-études.Part-time employment (PTE) among adolescents during their studies is an increasingly common social phenomenon in North America. However, how much do we know about its short and long term impacts on students’ scholastic and psychosocial adjustment between the middle and end of their secondary school studies? In the framework of a Québec study, standardized questionnaires were completed by students in the third, fourth and fifth years of secondary school in terms of daily problems, (Plancherel et al., 1997), adaptive strategies (Frydenberg et al., 1993), psychopathological problems (Achenbach, 1991), self esteem (Rosenberg, 1965), optimism (Scheier et al., 1985), autonomy (Greenberger et al., 1974) and part-time work (The Québec ministry of education’s adaptation (MÉQ), 1994). The students’ math and French marks, as well as their overall results were also collected. Globally, the results reveal that PTE while attending school is a risk factor for school adjustment for students in secondary three and four working more than eleven hours per week, but not for those in the same category in secondary 5. However, no real costs associated to PTE were observed on the psychosocial adjustment of adolescents in any of the three school cycles. Other analyses indicate that having a part time job in secondary three does not allow a prediction to be made about the severity of daily problems, personal resources, marks, and interiorized and exteriorized behaviours measured in secondary four, with the exception of adaptive productive and social strategies evaluated in secondary five. The conclusion emphasizes the importance of strengthening each student’s protection factors so they can to deal more effectively with the work-study combination.El trabajo a tiempo parcial (TTP) de los adolescentes durante los estudios es un fenómeno social cada vez más común en América del Norte. ¿Sin embargo, qué sabemos de sus impactos, a corto y mediano plazo, sobre la adaptación escolar y psicosocial de los alumnos a la mitad o al final de la secundaria? En el marco de un estudio quebequence, se aplicaron cuestionarios estandardizados entre los alumnos de tercero, cuarto y quinto de secundaria : preocupaciones cotidianas (Plancherel et al, 1997), estrategias de adaptación (Frydenberg et al., 1993), problemas psicopatológicos (Achenbach, 1991), auto-estima (Rosenberg, 1965), optimismo (Scheier et al., 1985), autonomía (Greenberger et al., 1974) y trabajo a tiempo parcial (adaptación del MEQ, 1994). Las calificaciones en matemáticas, en francés y en las otras materias fueron asimismo recopiladas. Globalmente, los resultados muestran que el TTP durante los estudios se presenta como un factor de riesgo para la adaptación escolar de los alumnos de tercero y cuarto de secundaria que trabajan más de once horas por semana, pero no para los alumnos de quinto de secundaria. En cambio, ningún costo real asociado al TTP durante los estudios ha sido observado sobre la adaptación psicosocial de los adolescentes y esto, para los tres ciclos escolares. Otros análisis indican que un TTP durante el tercero de secundaria no permite predecir la severidad de las preocupaciones cotidianas, los recursos personales, los resultados escolares y los comportamientos interiores y exteriores medidos en cuarto de secundaria, excepción hecha de las estrategias de adaptación productivas y sociales evaluadas en quinto de secundaria. Las conclusiones subrayan la importancia de reforzar los factores de protección de cada alumno para bien confrontar el tándem trabajo-estudios

Subthalamic Nucleus Stimulation Affects Fear and Sadness Recognition in Parkinson's Disease

Bilateral subthalamic nucleus (STN) deep brain stimulation (DBS) in Parkinson's disease (PD) can produce emotional disorders that have been linked to disturbance of the STN's limbic territory. The aim of this study was to confirm the impairment of the recognition of facial emotions (RFE) induced by STN DBS, not only ruling out the effect of the disease's natural progression in relation to the effect of DBS, but also assessing the influence of modifications in dopamine replacement therapy (DRT) following STN DBS. RFE was investigated in 24 PD patients who underwent STN DBS and 20 PD patients treated with apomorphine. They were assessed 3 months before and after treatment. The 2 patient groups were compared with a group of 30 healthy matched controls. The results showed that RFE for negative emotions (fear and sadness) was impaired in only the STN DBS group in the posttreatment condition and was unrelated to DRT. Results confirm the selective reduction of RFE induced by STN DBS, due neither to the disease's natural progression nor to modifications in DRT

Transport properties of iodide in a sandy aquifer: Hydrogeological modelling and field tracer tests

International audienceThe release of radioactive iodine into geological media from nuclear waste disposal is an issue that has tobe considered since iodine is a biophilic element. 129I is, with 99Tc, one of the two long-lived radionuclidesthat have the highest mobility in radioactive waste disposal. Within this context, iodide retardation is stilla matter of debate. A low value of the retardation factor is generally accepted in soils without organicmatter, but the possibility for sorption cannot be completely ruled out. Since isotopic exchange with naturallyoccurring iodine is one of the main potential sorption mechanisms, site-specific retention parametersare needed. In the present paper, we study iodide transport in a sandy aquifer. A hydrogeologicalmodel was built to fit deuterium, bromide and iodide breakthrough data from in situ tracer test experiments.Within the precision range of the fitting, iodide is excluded from 2.5% of the effective porosity byanionic exclusion and presents a field retention factor (Kd) lower than 0.025 L/kg

Subthalamic nucleus local field potentials recordings reveal subtle effects of promised reward during conflict resolution in Parkinson's disease

Cognitive action control depends on cortical-subcortical circuits, involving notably the subthalamic nucleus (STN), as evidenced by local field potentials recordings (LFPs) studies. The STN consistently shows an increase in theta oscillations power during conflict resolution. Some studies have shown that cognitive action control in Parkinson's disease (PD) could be influenced by the occurrence of monetary reward. In this study, we investigated whether incentive motivation could modulate STN activity, and notably STN theta activity, during response conflict resolution. To achieve this objective, we recorded STN LFPs during a motivated Simon task in PD patients who had undergone deep brain stimulation surgery. Behavioral results revealed that promised rewards increased the difficulty in resolving conflict situations, thus replicating previous findings. Signal analyses locked on the imperative stimulus onset revealed the typical pattern of increased theta power in a conflict situation. However, this conflict-related modulation of theta power was not influenced by the size of the reward cued. We nonetheless identified a significant effect of the reward size on local functional organization (indexed by inter-trial phase clustering) of theta oscillations, with higher organization associated with high rewards while resolving conflict. When focusing on the period following the onset of the reward cue, we unveiled a stronger beta power decrease in higher reward conditions. However, these LFPs results were not correlated to behavioral results. Our study suggests that the STN is involved in how reward information can influence computations during conflict reso- lution. However, considering recent studies as well as the present results, we suspect that these effects are subtle

Subthalamic nucleus oscillations during vocal emotion processing are dependent of the motor asymmetry of Parkinson's disease

International audienceThe subthalamic nucleus (STN) is involved in different aspects of emotional processes and more specifically in emotional prosody recognition. Recent studies on the behavioral effects of deep brain stimulation (DBS) in patients with Parkinson's disease (PD) have uncovered an asymmetry in vocal emotion decoding in PD, with left-onset PD patients showing deficits for the processing of happy voices. Whether and how PD asymmetry affects STN electrophysiological responses to emotional prosody, however, remains unknown. In the current study, local field potential activity was recorded from eight left- and six right-lateralized motor-onset PD patients (LOPD/ROPD) undergoing DBS electrodes implantation, while they listened to angry, happy and neutral voices. Time-frequency decomposition revealed that theta (2-6 Hz), alpha (6-12 Hz) and gamma (60-150 Hz) band responses to emotion were mostly bilateral with a differential pattern of response according to patient's sides-of onset. Conversely, beta-band (12-20 Hz and 20-30 Hz) emotional responses were mostly lateralized in the left STN for both patient groups. Furthermore, STN theta, alpha and gamma band responses to happiness were either absent (theta band) or reduced (alpha and gamma band) in the most affected STN hemisphere (contralateral to the side-of onset), while a late low-beta band left STN happiness-specific response was present in ROPD patients and did not occur in LOPD patients. Altogether, in this study, we demonstrate a complex pattern of oscillatory activity in the human STN in response to emotional voices and reveal a crucial influence of disease laterality on STN low-frequency oscillatory activity

Vocal emotion decoding in the subthalamic nucleus: An intracranial ERP study in Parkinson's disease

Using intracranial local field potential (LFP) recordings in patients with Parkinson's disease (PD) undergoing deep brain stimulation (DBS), we explored the electrophysiological activity of the subthalamic nucleus (STN) in response to emotional stimuli in the auditory modality. Previous studies focused on the influence of visual stimuli. To this end, we recorded LFPs within the STN in response to angry, happy, and neutral prosodies in 13 patients with PD who had just undergone implantation of DBS electrodes. We observed specific modulation of the right STN in response to anger and happiness, as opposed to neutral prosody, occurring at around 200–300 ms post-onset, and later at around 850–950 ms post-onset for anger and at around 3250–3350 ms post-onset for happiness. Taken together with previous reports of modulated STN activity in response to emotional visual stimuli, the present results appear to confirm that the STN is involved in emotion processing irrespective of stimulus valence and sensory modality