Substrate Temperature Constrains Recruitment and Trail Following Behavior in Ants

In many ant species, foragers use pheromones to communicate the location of resources to nestmates. Mass-recruiting species deposit long-lasting anonymous chemical trails, while group-recruiting species use temporary chemical trails. We studied how high temperature influenced the foraging behavior of a mass-recruiting species (Tapinoma nigerrimum) and a group-recruiting species (Aphaenogaster senilis) through pheromone decay. First, under controlled laboratory conditions, we examined the effect of temperature on the trail pheromone of both species. A substrate, simulating soil, marked with gaster extract was heated for 10 min. at 25°, 35°, 45°, or 55 °C and offered to workers in a choice test. Heating gaster extract reduced the trail following behavior of the mass-recruiters significantly more than that of the group-recruiters. Second, analyses of the chemicals present on the substrate indicated that most T. nigerrimum gaster secretions vanished at 25 °C, and only iridodials persisted up to 55 °C. By contrast, A. senilis secretions were less volatile and resisted better to elevated temperatures to some extent. However, at 55 °C, the only chemicals that persisted were nonadecene and nonadecane. Overall, our results suggest that the foraging behavior of the group-recruiting species A. senilis is less affected by pheromone evaporation than that of the mass-recruiting species T. nigerrimum. This group-recruiting species might, thus, be particularly adapted to environments with fluctuating temperatures. © 2012 Springer Science+Business Media, LLC.Peer Reviewe

Role of brain imaging in disorders of brain-gut interaction: a Rome Working Team Report.

Imaging of the living human brain is a powerful tool to probe the interactions between brain, gut and microbiome in health and in disorders of brain-gut interactions, in particular IBS. While altered signals from the viscera contribute to clinical symptoms, the brain integrates these interoceptive signals with emotional, cognitive and memory related inputs in a non-linear fashion to produce symptoms. Tremendous progress has occurred in the development of new imaging techniques that look at structural, functional and metabolic properties of brain regions and networks. Standardisation in image acquisition and advances in computational approaches has made it possible to study large data sets of imaging studies, identify network properties and integrate them with non-imaging data. These approaches are beginning to generate brain signatures in IBS that share some features with those obtained in other often overlapping chronic pain disorders such as urological pelvic pain syndromes and vulvodynia, suggesting shared mechanisms. Despite this progress, the identification of preclinical vulnerability factors and outcome predictors has been slow. To overcome current obstacles, the creation of consortia and the generation of standardised multisite repositories for brain imaging and metadata from multisite studies are required

Contribution à l'élaboration d'un formalisme gérant la pertinence pour les problèmes d'aide à la conception à base de contraintes

Les travaux présentés dans cette thèse portent sur l'aide à la conception et à la configuration. Une intégration de différents concepts existant dans les domaines de la programmation par contraintes a été réalisée. Cette intégration a pu être testée sur une implémentation basée sur des arbres syntaxiques représentant un CSP (problème de satisfaction de contraintes) modélisant un problème de conception ou configuration. La première partie de la thèse présente les domaines de la conception et de la configuration, et en fait ressortir les besoins pour l'aide à la décision : paramètres discrets et continus, organisation hiérarchique et éléments optionnels. Différentes approches à base de contraintes permettant de répondre à ces besoins sont ensuite détaillées. La seconde partie présente les RCSP (CSP gérant la pertinence), qui intègrent les différents mécanismes vus dans la première partie. Des préconisations de modélisation pour les problèmes de conception et de configuration sont établies. L'outil réalisé est ensuite présenté, dans un premier temps pour le traitement de problèmes CSP et dans un deuxième temps pour le traitement de RCSP

Contribution à l'élaboration d'un formalisme gérant la pertinence pour les problèmes d'aide à la conception à base de contraintes

Les travaux présentés dans cette thèse portent sur l'aide à la conception et à la configuration. Une intégration de différents concepts existant dans les domaines de la programmation par contraintes a été réalisée. Cette intégration a pu être testée sur une implémentation basée sur des arbres syntaxiques représentant un CSP (problème de satisfaction de contraintes) modélisant un problème de conception ou configuration. La première partie de la thèse présente les domaines de la conception et de la configuration, et en fait ressortir les besoins pour l'aide à la décision : paramètres discrets et continus, organisation hiérarchique et éléments optionnels. Différentes approches à base de contraintes permettant de répondre à ces besoins sont ensuite détaillées. La seconde partie présente les RCSP (CSP gérant la pertinence), qui intègrent les différents mécanismes vus dans la première partie. Des préconisations de modélisation pour les problèmes de conception et de configuration sont établies. L'outil réalisé est ensuite présenté, dans un premier temps pour le traitement de problèmes CSP et dans un deuxième temps pour le traitement de RCSP. ABSTRACT : The research work presented in this thesis deals with assistance to design and configuration tasks. An integration of different existing concepts of constraint programming has been achieved. This integration has been tested on an implementation based upon syntaxic trees. The syntaxic trees allow to express different kinds of CSP (Constraint Satisfaction Problem) which model design or configuration problems. The first part presents the fields of design and configuration, and aims at identifying the needs for decision aid: different kinds of parameters (discrete and continuous), hierarchical organisation and optionnal elements. Different constraint-based approaches which may fulfill any need are then detailed. The second part presents the RCSP (Relevancy CSP), which are an integration of different CSP from the literature seen in the first part. Some recommendations for modeling design or configuration problems are set up. The implementation is then presented, on the one hand for CSP processing and on the other hand for RCSP processing

Coping Skills Are Associated With Gastrointestinal Symptom Severity and Somatization in Patients With Irritable Bowel Syndrome

BACKGROUND & AIMS: Coping resources and processes are altered in patients with irritable bowel syndrome (IBS). We investigated the relationship between coping resources and gastrointestinal (GI) and extraintestinal symptom severity in patients with IBS and potential mediators of this relationship. METHODS: We performed a cross-sectional study of 216 patients with IBS attending a secondary/tertiary care specialized outpatient center in Sweden from 2003 through 2007. We collected data on coping resources, levels of anxiety (general and GI specific), depressive symptoms, levels of GI symptoms, and extraintestinal somatic symptoms (somatization) by administering validated self-report questionnaires. General Linear Models were used to assess associations and mediation. RESULTS: GI symptoms: low levels of physical coping resources (practice of activities that are beneficial for health; P = .0016), high levels of general anxiety symptoms (P = .033), and GI-specific anxiety symptoms (P < .0001), but not depressive symptoms (P = .89), were independently associated with GI symptom levels (R2 = 0.31). Anxiety and GI-specific anxiety partially mediated the effect of physical coping. Somatization: low levels of physical coping resources (P = .003), high levels of anxiety (P = .0147), depressive (P = .0005), and GI-specific anxiety symptoms (P = .06) were associated with somatization levels (R2 = 0.35). Levels of general and GI-specific anxiety and depressive symptoms partially mediated this physical coping effect. The effect of psychological coping resources (including optimism, social support, and accepting/expressing emotions) on somatization levels was not significant (P = .98), but was fully mediated by levels of anxiety and depressive symptoms, and partially by levels of GI-specific anxiety symptoms. CONCLUSIONS: In a cross-sectional study of patients with IBS in Sweden, we found associations of levels of coping resources with GI and extraintestinal symptom severity; these associations were mediated by levels of anxiety and depressive symptoms. Although confirmation in longitudinal studies is needed, this identifies coping as a potential psychological treatment target in IBS

Immune-active microenvironment in small cell carcinoma of the ovary, hypercalcemic type : rationale for immune checkpoint blockade

Small cell carcinoma of the ovary, hypercalcemic type (SCCOHT), is a highly aggressive monogenic cancer driven by SMARCA4 mutations. Here, we report responses to anti-PD1 immunotherapy in four patients and characterize the immune landscape of SCCOHT tumors using quantitative immunofluorescence and gene expression profiling. Unexpectedly for a low mutation burden cancer, the majority of the tumors (eight of 11 cases) demonstrated PD-L1 expression with strong associated T-cell infiltration (R2 = 0.60–0.95). PD-L1 expression was detected in both tumor and stromal cells, with macrophages being the most abundant PD-L1-positive cells in some tumors (three of 11 cases). Transcriptional profiling revealed increased expression of genes related to Th1 and cytotoxic cell function in PD-L1-high tumors, suggesting that PD-L1 acts as a pathway of adaptive immune resistance in SCCOHT. These findings suggest that although SCCOHT are low–mutational burden tumors, their immunogenic microenvironment resembles the landscape of tumors that respond well to treatment with PD-1/PD-L1 blockade

The three R’s of scientific integrity:Replicability, reproducibility, and robustness

It has been proposed that memory retrieval can destabilize consolidated memories, after which they need to be reconsolidated in order to be retained. The presentation of relevant information during memory reconsolidation could then result in the modification of a destabilized memory trace, by allowing the memory trace to be updated before being reconsolidated. In line with this idea, Schiller et al. (2010) have demonstrated that memory retrieval shortly before extinction training can prevent the later recovery of conditioned fear responding that is observed after regular extinction training. Those findings have been the subject of considerable controversy, due in part to theoretical reasons but also due to a number of failures to obtain similar results in conceptual replication attempts. Here, we report the results of a highly powered, direct, independent replication of the critical conditions of Schiller et al. (2010, Experiment 1). Due to misrepresentation of the exclusion criteria in the original Schiller et al. (2010) report, data collection was considerably delayed. When we eventually managed to attain our pre-registered sample size, we found that we could not observe any benefit of reactivation-extinction over regular extinction training in preventing recovery of conditioned fear. The results of the present study, along with the mixed findings in the literature and the misreporting in Schiller et al. (2010), give cause to question whether there is robust evidence that reactivation-extinction prevents the return of fear in humans.status: publishe

Protein markers for insulin-producing beta cells with higher glucose sensitivity

Background and Methodology: Pancreatic beta cells show intercellular differences in their metabolic glucose sensitivity and associated activation of insulin production. To identify protein markers for these variations in functional glucose sensitivity, rat beta cell subpopulations were flow-sorted for their level of glucose-induced NAD(P) H and their proteomes were quantified by label-free data independent alternate scanning LC-MS. Beta cell-selective proteins were also identified through comparison with rat brain and liver tissue and with purified islet alpha cells, after geometrical normalization using 6 stably expressed reference proteins. Principal Findings: All tissues combined, 943 proteins were reliably quantified. In beta cells, 93 out of 467 quantifiable proteins were uniquely detected in this cell type; several other proteins presented a high molar abundance in beta cells. The proteome of the beta cell subpopulation with high metabolic and biosynthetic responsiveness to 7.5 mM glucose was characterized by (i) an on average 50% higher expression of protein biosynthesis regulators such as 40S and 60S ribosomal constituents, NADPH-dependent protein folding factors and translation elongation factors; (ii) 50% higher levels of enzymes involved in glycolysis and in the cytosolic arm of the malate/aspartate-NADH-shuttle. No differences were noticed in mitochondrial enzymes of the Krebs cycle, beta-oxidation or respiratory chain. Conclusions: Quantification of subtle variations in the proteome using alternate scanning LC-MS shows that beta cell metabolic glucose responsiveness is mostly associated with higher levels of glycolytic but not of mitochondrial enzymes