Integrating detection probabilities in species distribution models of amphibians breeding in Mediterranean temporary ponds

Aim  The imperfect detection of species may lead to erroneous conclusions about species-environment relationships. Accuracy in species detection usually requires temporal replication at sampling sites, a time-consuming and costly monitoring scheme. Here, we applied a lower-cost alternative based on a double-sampling approach to incorporate the reliability of species detection into regression-based species distribution modelling.Location  Doñana National Park (south-western Spain).Methods  Using species-specific monthly detection probabilities, we estimated the detection reliability as the probability of having detected the species given the species-specific survey time. Such reliability estimates were used to account explicitly for data uncertainty by weighting each absence. We illustrated how this novel framework can be used to evaluate four competing hypotheses as to what constitutes primary environmental control of amphibian distribution: breeding habitat, aestivating habitat, spatial distribution of surrounding habitats and/or major ecosystems zonation. The study was conducted on six pond-breeding amphibian species during a 4-year period.Results  Non-detections should not be considered equivalent to real absences, as their reliability varied considerably. The occurrence of Hyla meridionalis and Triturus pygmaeus was related to a particular major ecosystem of the study area, where suitable habitat for these species seemed to be widely available. Characteristics of the breeding habitat (area and hydroperiod) were of high importance for the occurrence of Pelobates cultripes and Pleurodeles waltl. Terrestrial characteristics were the most important predictors of the occurrence of Discoglossus galganoi and Lissotriton boscai, along with spatial distribution of breeding habitats for the last species.Main conclusions  We did not find a single best supported hypothesis valid for all species, which stresses the importance of multiscale and multifactor approaches. More importantly, this study shows that estimating the reliability of non-detection records, an exercise that had been previously seen as a naïve goal in species distribution modelling, is feasible and could be promoted in future studies, at least in comparable systems.

The effects of physiologically plausible connectivity structure on local and global dynamics in large scale brain models.

Functionally relevant large scale brain dynamics operates within the framework imposed by anatomical connectivity and time delays due to finite transmission speeds. To gain insight on the reliability and comparability of large scale brain network simulations, we investigate the effects of variations in the anatomical connectivity. Two different sets of detailed global connectivity structures are explored, the first extracted from the CoCoMac database and rescaled to the spatial extent of the human brain, the second derived from white-matter tractography applied to diffusion spectrum imaging (DSI) for a human subject. We use the combination of graph theoretical measures of the connection matrices and numerical simulations to explicate the importance of both connectivity strength and delays in shaping dynamic behaviour. Our results demonstrate that the brain dynamics derived from the CoCoMac database are more complex and biologically more realistic than the one based on the DSI database. We propose that the reason for this difference is the absence of directed weights in the DSI connectivity matrix.

Role of the inflammasome in murine experimental models of arthritis

Summary : The purpose of this study was to investigate the role of the inflammasome in human and experimental murine models (such as ΑΙΑ and K/BxN) of rheumatoid arthritis (RA)RA, affecting 1% of the population is the most frequent inflammatory disease characterized by synovial hyperplasia and cartilage and bone erosion, leading to joint destruction. In general, women are 3 times more affected by RA suggesting a role of estrogen in this disease. The inflammasome is a multiproteic complex triggering the activation of caspase-1 leading to the activation of IL-1 β, an important pro-inflammatory cytokine implicated in arthritis. The inflammasome has been implicated in several inflammatory diseases and particularly in gout. To highlight a possible role of the inflammasome in murine arthritis, we obtained ASC, caspase-1 and NALP3 +/+ and -/- littermate mice to perform ΑΙΑ and K/BxN arthritis. NALP3 -/- and caspase-1 -/- mice were as arthritic as wild type littermate mice in both ΑΙΑ and K/BxN models implicating that the NALP3 inflammasome is not involved in experimental arthritis. By contrast, ΑΙΑ severity was significantly diminished in ASC- deficient male and female mice, and in the K/BxN model, in ASC-deficient female mice. These results were supported by histological scoring and acute phase protein serum amyloid A (SAA) levels that were equivalent between NALP+/+ and NALP3-/- mice and diminished in ASC -/- mice. In ΑΙΑ and K/BxN murine experimental models, we observed a sexdependent phenotype. We studied the role of estradiol in both the ALA and the K/BxN models. Castrated female or male ASC -/- mice that received estradiol had a decreased arthritis severity. This implies a protective role of estrogen in the absence of ASC. In the ΑΙΑ model, proliferation assay were performed using splenocytes from mBSA- immunized ASC +/+ and -/- mice. The mBSA-induced proliferation was significantly lower in ASC-/- splenocytes. Moreover the CD3-specific proliferation of purified splenic Τ cells was significantly lower in ASC-/- cells. Finally, Τ cells from ASC-/- mice produced significantly decreased levels of IFN-gamma associated with increased levels of IL-10. These results imply a possible role of ASC in the TCR-signaling pathway and Τ cell cytokine production. In parallel the expression of the different inflammasome components were analyzed in biopsies from rheumatoid arthritis (RA) and osteoarthritis (OA) patiens. The expression of the 14 different NALPs, their effector protein ASC, and caspase-1 and -5 was readily measurable by RT-PCR in a similar proportion in RA and OA synovial samples, with the exception of NALP-5 and NALP-13, which weren't found in samples from either disease. The corresponding NALP1, -3, -12 and ASC proteins were expressed at similar levels in both OA and RA biopsies, as determined by immunohistochemistry and Western-blot analysis. By contrast, caspase-1 levels were significantly enhanced in RA synovial tissues compared to those from OA patients. NALP-1, -2, -3, -10, -12 and -14, as well as ASC, caspase-1, and -5 were detected in RNA from unstimulated and stimulated RA synoviocytes. In FLS, only ASC and caspase-1 were expressed at the protein level. NALP1, 3 and 12 were not detected. However, upon stimulation, no secreted IL-Ιβ was detectable in either RA or in OA synoviocytes culture medium. Résumé : Le but de ce projet était d'étudier le rôle de l'inflammasome dans des modèles expérimentaux d'arthrite tels que les modèles ΑΙΑ et K/BxN ainsi que dans la polyarthrite humaine (RA). La polyarthrite est une maladie inflammatoire très fréquente avec 1 % de la population affectée et touche 3 fois plus les femmes que les hommes, suggérant un rôle des hormones sexuelles dans cette pathologie. L'inflammasome est un complexe multiprotéique qui permet l'activation de la caspase-1, une cystéine protéase qui va ensuite cliver et activer rinterleukine-ΐβ (IL-Ιβ). L'inflammasome a été impliqué ces dernières années dans de nombreuses maladies inflammatoires notamment dans la goutte. Pour mettre en évidence un éventuel rôle de l'inflammasome dans l'arthrite expérimentale nous avons obtenu des souris déficientes pour certains des composants de l'inflammasome tels que ASC, NALP3 et caspase-1. Les souris NALP3 déficientes et caspase-1 déficientes sont aussi arthritiques que les souris wild type correspondantes que ce soit dans le modèle ΑΙΑ ou K/BxN. Par contre les souris mâles et femelles ASC-déficientes sont moins arthritiques que les souris +/+ correspondantes dans le modèle ΑΙΑ. Dans le modèle KRN, le même phénotype (diminution de la sévérité de l'arthrite) est observé uniquement chez les femelles ASC-/- Ce phénotype est corrélé avec l'histologie ainsi qu'avec le dosage du serum amyloid A (SAA) qui reflète l'inflammation systémique et qui est diminué chez les souris ASC-déficientes. Nous avons ensuite étudié le rôle de Γ estradiol (une des formes active des estrogènes) dans les modèles K/BxN et ΑΙΑ. Les souris castrées maies ou femelles déficientes pour ASC ayant reçu de l'estradiol ont une arthrite moins sévère ce qui implique que les estradiol ont un effet protecteur en l'absence de ASC. Dans le modèle ΑΙΑ, nous nous sommes aussi intéressés à la réponse immune. Des tests de prolifération ont été effectués sur des splénocytes en présence de mBSA (qui est l'antigène utilisé dans le modèle ΑΙΑ). Les splénocytes ASC -/- ont une proliferation qui est diminuée en présence de l'antigène. De plus la proliferation de cellules Τ spléniques purifiées en présence d'anti-CD3 est diminuée chez les cellules Τ ASC-/-. Ces résultats nous indiquent une éventuelle implication de ASC dans la signalisation par le récépteur des cellules T. En parallèle l'expression des différents composants de l'inflammasome a été analysée dans des biopsies de patients atteints de polyarthrite rhumatoide (RA) et d'arthrose (OA). L'expression des 14 différents NALPs, de l'adaptateur ASC, ainsi que des caspase-1 et -5 était similaires dans les échantillons RA et OA, à l'exception de NALP5 et 13 qui n'étaient pas détéctables. L'expression protéique de NALP1, 3, 12 et ASC effectuée par Western blot et immunohistochimie était similaire dans les biopsies RA et OA. Par contre la quantité de la caspase-1 mesurée par ELISA était augmentée de façon significative dans les extraits protéiques de biopsies RA. NALP-1, -2. -3, -10, -12, and -14 ainsi que ASC, caspase-1 et -5 étaient exprimés de façon similaire par les synoviocytes RA non stimulés et stimulés. Dans les synoviocytes seuls ASC et caspase-1 étaient détéctable au niveau protéique. NALP-1, -3 et -12 n'était pas détéctables. Cependant après stimulation il n'y avait d'IL-Ιβ sécrété que ce soit dans les surnageants de cultures de synoviocytes RA ou OA.

Towards a resolution of conflicting models of illusory contour processing in humans.

Despite myriad studies, neurophysiologic mechanisms mediating illusory contour (IC) sensitivity remain controversial. Among the competing models one favors feed-forward effects within lower-tier cortices (V1/V2). Another situates IC sensitivity first within higher-tier cortices, principally lateral-occipital cortices (LOC), with later feedback effects in V1/V2. Still others postulate that LOC are sensitive to salient regions demarcated by the inducing stimuli, whereas V1/V2 effects specifically support IC sensitivity. We resolved these discordances by using misaligned line gratings, oriented either horizontally or vertically, to induce ICs. Line orientation provides an established assay of V1/V2 modulations independently of IC presence, and gratings lack salient regions. Electrical neuroimaging analyses of visual evoked potentials (VEPs) disambiguated the relative timing and localization of IC sensitivity with respect to that for grating orientation. Millisecond-by-millisecond analyses of VEPs and distributed source estimations revealed a main effect of grating orientation beginning at 65 ms post-stimulus onset within the calcarine sulcus that was followed by a main effect of IC presence beginning at 85 ms post-stimulus onset within the LOC. There was no evidence for differential processing of ICs as a function of the orientation of the grating. These results support models wherein IC sensitivity occurs first within the LOC.

MORM--a Petri net based model for assessing OH&S risks in industrial processes: modeling qualitative aspects.

Because of the increase in workplace automation and the diversification of industrial processes, workplaces have become more and more complex. The classical approaches used to address workplace hazard concerns, such as checklists or sequence models, are, therefore, of limited use in such complex systems. Moreover, because of the multifaceted nature of workplaces, the use of single-oriented methods, such as AEA (man oriented), FMEA (system oriented), or HAZOP (process oriented), is not satisfactory. The use of a dynamic modeling approach in order to allow multiple-oriented analyses may constitute an alternative to overcome this limitation. The qualitative modeling aspects of the MORM (man-machine occupational risk modeling) model are discussed in this article. The model, realized on an object-oriented Petri net tool (CO-OPN), has been developed to simulate and analyze industrial processes in an OH&S perspective. The industrial process is modeled as a set of interconnected subnets (state spaces), which describe its constitutive machines. Process-related factors are introduced, in an explicit way, through machine interconnections and flow properties. While man-machine interactions are modeled as triggering events for the state spaces of the machines, the CREAM cognitive behavior model is used in order to establish the relevant triggering events. In the CO-OPN formalism, the model is expressed as a set of interconnected CO-OPN objects defined over data types expressing the measure attached to the flow of entities transiting through the machines. Constraints on the measures assigned to these entities are used to determine the state changes in each machine. Interconnecting machines implies the composition of such flow and consequently the interconnection of the measure constraints. This is reflected by the construction of constraint enrichment hierarchies, which can be used for simulation and analysis optimization in a clear mathematical framework. The use of Petri nets to perform multiple-oriented analysis opens perspectives in the field of industrial risk management. It may significantly reduce the duration of the assessment process. But, most of all, it opens perspectives in the field of risk comparisons and integrated risk management. Moreover, because of the generic nature of the model and tool used, the same concepts and patterns may be used to model a wide range of systems and application fields.

Alkylpurine-DNA-N-glycosylase confers resistance to temozolomide in xenograft models of glioblastoma multiforme and is associated with poor survival in patients.

Glioblastoma multiforme (GBM) is the most common and lethal of all gliomas. The current standard of care includes surgery followed by concomitant radiation and chemotherapy with the DNA alkylating agent temozolomide (TMZ). O⁶-methylguanine-DNA methyltransferase (MGMT) repairs the most cytotoxic of lesions generated by TMZ, O⁶-methylguanine. Methylation of the MGMT promoter in GBM correlates with increased therapeutic sensitivity to alkylating agent therapy. However, several aspects of TMZ sensitivity are not explained by MGMT promoter methylation. Here, we investigated our hypothesis that the base excision repair enzyme alkylpurine-DNA-N-glycosylase (APNG), which repairs the cytotoxic lesions N³-methyladenine and N⁷-methylguanine, may contribute to TMZ resistance. Silencing of APNG in established and primary TMZ-resistant GBM cell lines endogenously expressing MGMT and APNG attenuated repair of TMZ-induced DNA damage and enhanced apoptosis. Reintroducing expression of APNG in TMZ-sensitive GBM lines conferred resistance to TMZ in vitro and in orthotopic xenograft mouse models. In addition, resistance was enhanced with coexpression of MGMT. Evaluation of APNG protein levels in several clinical datasets demonstrated that in patients, high nuclear APNG expression correlated with poorer overall survival compared with patients lacking APNG expression. Loss of APNG expression in a subset of patients was also associated with increased APNG promoter methylation. Collectively, our data demonstrate that APNG contributes to TMZ resistance in GBM and may be useful in the diagnosis and treatment of the disease.

A two-level analysis of the determinants of direct democratic choices in European, immigration and foreign policy in Switzerland

This article employs a unique data set - covering 25 popular votes on foreign, European and immigration/asylum policy held between 1992 and 2006 in Switzerland - in order to examine the conditional impact of context upon utilitarian, cultural, political and cognitive determinants of individual attitudes toward international openness. Our results reveal clear patterns of cross-level interactions between individual determinants and the project-related context of the vote. Thus, although party cues and political competence have a strong impact on individuals' support for international openness, this impact is substantially mediated by the type of coalition that is operating within the party elite. Similarly, subjective utilitarian and cultural considerations influence the voters' decision in interaction with the content of the proposal submitted to the voters as well as with the framing of the voting campaign.