Climate, biodiversity, land use changes and zoonotic infectious diseases in Southeast Asia : O15

Numerous parasitic and infectious diseases are emerging, re-emerging or causing recurrent outbreaks in Southeast-Asia, a hot spot of both infectious disease emergence and biodiversity at threat. Here, we present ongoing results of the BiodivHealtSEA project on the potential effects of global changes (climate, biodiversity and land use) on the epidemiology and diversity of infectious diseases, focusing on zoonotic diseases (and specifically rodent-borne diseases), from regional to local scales. At regional level, we show, among countries, that the overall richness of infectious diseases is positively correlated with the level of biodiversity (i.e. richness of birds and mammals). However, the number of zoonotic disease outbreaks is positively correlated with the number of threatened mammal and bird species and the number of vector-borne disease outbreaks is negatively correlated with forest cover. These results suggest that, among countries, biodiversity is a source of pathogens, but also that the loss of biodiversity or its regulation, as measured by forest cover or threatened species, seems to be associated with an increase in zoonotic and vector-borne disease outbreaks. A national level of Thailand, we show how the climate variability (ENSO), which explains the total amount of rainfalls, contributes globally to the leptospirosis incidence and scrub typhus during the last 10 years in Thailand. The ongoing climate change that seems to affect climate variability (monsoon intensity) will affect consequently the epidiological dynamics of these diseases. A local scale, using an extensive data on rodents and their parasites/pathogens in 7 localities of Southeast Asia, for which land cover changes have been developed, we show that fast growing habitat fragmentation may affect parasite/pathogen species richness and particularly the diversity of rodent-borne pathogens. Moreover, using network analysis we show important effect of the habitat fragmentation on the network architecture with network becomes less connected and more modular. These effects suggest that parasites transmission between host species may become more difficult with the increase of habitat disturbance. In conclusion the results presented here suggest that loss of biodiversity and land use changes affect negatively the diversity of pathogens, but may increase the risks of the remaining ones (through increase of outbreaks, or prevalence in the reservoirs). (Texte intégral

Time course of evoked-potential changes in different forms of anomia in aphasia

No abstract available

Attractor non-equilibrium stationary states in perturbed long-range interacting systems

Isolated long-range interacting particle systems appear generically to relax to non-equilibrium states ("quasi-stationary states" or QSS) which are stationary in the thermodynamic limit. A fundamental open question concerns the "robustness" of these states when the system is not isolated. In this paper we explore, using both analytical and numerical approaches to a paradigmatic one dimensional model, the effect of a simple class of perturbations. We call them "internal local perturbations" in that the particle energies are perturbed at collisions in a way which depends only on the local properties. Our central finding is that the effect of the perturbations is to drive all the very different QSS we consider towards a unique QSS. The latter is thus independent of the initial conditions of the system, but determined instead by both the long-range forces and the details of the perturbations applied. Thus in the presence of such a perturbation the long-range system evolves to a unique non-equilibrium stationary state, completely different to its state in absence of the perturbation, and it remains in this state when the perturbation is removed. We argue that this result may be generic for long-range interacting systems subject to perturbations which are dependent on the local properties (e.g. spatial density or velocity distribution) of the system itself.Comment: 16 pages, 12 figure

Looking away from faces: influence of high-level visual processes on saccade programming

Human faces capture attention more than other visual stimuli. Here we investigated whether such face-specific biases rely on automatic (involuntary) or voluntary orienting responses. To this end, we used an anti-saccade paradigm, which requires the ability to inhibit a reflexive automatic response and to generate a voluntary saccade in the opposite direction of the stimulus. To control for potential low-level confounds in the eye-movement data, we manipulated the high-level visual properties of the stimuli while normalizing their global low-level visual properties. Eye movements were recorded in 21 participants who performed either pro- or anti-saccades to a face, car, or noise pattern, randomly presented to the left or right of a fixation point. For each trial, a symbolic cue instructed the observer to generate either a pro-saccade or an anti-saccade. We report a significant increase in anti-saccade error rates for faces compared to cars and noise patterns, as well as faster pro-saccades to faces and cars in comparison to noise patterns. These results indicate that human faces induce stronger involuntary orienting responses than other visual objects, i.e., responses that are beyond the control of the observer. Importantly, this involuntary processing cannot be accounted for by global low-level visual factors

Embedding nonrelativistic physics inside a gravitational wave

Gravitational waves with parallel rays are known to have remarkable properties: Their orbit space of null rays possesses the structure of a non-relativistic spacetime of codimension-one. Their geodesics are in one-to-one correspondence with dynamical trajectories of a non-relativistic system. Similarly, the null dimensional reduction of Klein-Gordon's equation on this class of gravitational waves leads to a Schroedinger equation on curved space. These properties are generalized to the class of gravitational waves with a null Killing vector field, of which we propose a new geometric definition, as conformally equivalent to the previous class and such that the Killing vector field is preserved. This definition is instrumental for performing this generalization, as well as various applications. In particular, results on geodesic completeness are extended in a similar way. Moreover, the classification of the subclass with constant scalar invariants is investigated.Comment: 56 pages, 9 figures, v3:Minor correction