110 research outputs found
De l'inefficacité du réseau social : des liens sociaux non mobilisés chez les patients atteints de cancer
International audienceDe nombreuses Ă©tudes sur les rĂ©seaux sociaux portent sur la question des ressources auxquelles un individu peut avoir accĂšs Ă travers ses relations sociales. En s'intĂ©ressant aux rĂ©seaux qui ont « fonctionnĂ© », elles tentent alors de spĂ©cifier les facteurs ayant permis l'accĂšs aux ressources. Mais peu de travaux se sont penchĂ©s sur les rĂ©seaux ayant Ă©chouĂ© Ă fournir Ă l'individu le bien ou le service qu'il recherchait. Cet article se propose de discuter de ces rĂ©seaux « inefficaces » Ă travers le cas de patients atteints de cancer recherchant des informations relatives Ă leur pathologie. Les rĂ©sultats indiquent que les causes de l'inefficacitĂ© du rĂ©seau sont Ă rechercher dans la non mobilisation des liens de la part des malades rencontrĂ©s. Un certain nombre de contraintes pĂšsent sur ces liens empĂȘchant ainsi leur mobilisation
Dual-wavelength laser source for onboard atom interferometry
We present a compact and stable dual-wavelength laser source for onboard atom
interferometry with two different atomic species. It is based on
frequency-doubled telecom lasers locked on a femtosecond optical frequency
comb. We take advantage of the maturity of fiber telecom technology to reduce
the number of free-space optical components which are intrinsically less
stable, and to make the setup immune to vibrations and thermal fluctuations.
The source provides the frequency agility and phase stability required for atom
interferometry and can easily be adapted to other cold atom experiments. We
have shown its robustness by achieving the first dual-species K-Rb magneto
optical trap in microgravity during parabolic flights
Anti-proliferative effect of Rosmarinus officinalis L. extract on human melanoma A375 cells
Rosemary (Rosmarinus officinalis L.) has been used since ancient times in traditional medicine, while nowadays various rosemary formulations are increasingly exploited by alternative medicine to cure or prevent a wide range of health disorders. Rosemary's bioproperties have prompted scientific investigation, which allowed us to ascertain antioxidant, anti-inflammatory, cytostatic, and cytotoxic activities of crude extracts or of pure components. Although there is a growing body of experimental work, information about rosemary's anticancer properties, such as chemoprotective or anti-proliferative effects on cancer cells, is very poor, especially concerning the mechanism of action. Melanoma is a skin tumor whose diffusion is rapidly increasing in the world and whose malignancy is reinforced by its high resistance to cytotoxic agents; hence the availability of new cytotoxic drugs would be very helpful to improve melanoma prognosis. Here we report on the effect of a rosemary hydroalcoholic extract on the viability of the human melanoma A375 cell line. Main components of rosemary extract were identified by liquid chromatography coupled to tandem mass spectrometry (LC/ESI-MS/MS) and the effect of the crude extract or of pure components on the proliferation of cancer cells was tested by MTT and Trypan blue assays. The effect on cell cycle was investigated by using flow cytometry, and the alteration of the cellular redox state was evaluated by intracellular ROS levels and protein carbonylation analysis. Furthermore, in order to get information about the molecular mechanisms of cytotoxicity, a comparative proteomic investigation was performed
Grasp It Loudly! Supporting Actions with Semantically Congruent Spoken Action Words
Evidence for cross-talk between motor and language brain structures has accumulated over the past several years. However, while a significant amount of research has focused on the interaction between language perception and action, little attention has been paid to the potential impact of language production on overt motor behaviour
Natural autoantibodies against heat-shock proteins hsp70 and gp96: implications for immunotherapy using heat-shock proteins
Immunization of mice with cognate cancer-derived heat-shock protein (hsp) preparations leads to protection from cancer growth. As hsp used for vaccination or therapy are derived from autologous cancers, questions of pathological autoimmunity are of immense significance for the ongoing translation of this approach to therapy of human cancer. Employing the sera of normal adult mice as the first antibody, highly sensitive immunoblotting revealed the presence of anti-hsp natural autoantibodies in healthy animals. Natural autoantibodies of the immunoglobulin D (IgD) isotype bind to gp96, whereas hsp70 was recognized by IgD and IgM autoantibodies. Neither hsp was recognized by the IgA, IgE or IgG immunoglobulins contained in the serum. The antigenâantibody recognition was titratable and dependent on the integrity of the IgD molecule. Sera from only a subset of the animals tested were found to be positive for autoantibodies against gp96 and hsp70, and individual and strain-specific variations were detected. Injection of gp96 into healthy mice did not show sustained or consistent anti-gp96 IgD antibody response, class switching, toxicity or pathological autoimmunity. IgD autoantibodies against gp96 and hsp70 were also not detected in the autoimmune lpr mice. These observations show the existence of a measured and tightly regulated natural immune response to hsp
Matter-wave inertial sensing in microgravity : towards a test of the Universality on Free-fall
International audienc
Simultaneous action execution and observation optimise grasping actions.
International audienceAction observation and execution share overlapping neural resonating mechanisms. In the present study, we sought to examine the effect of the activation of this system during concurrent movement observation and execution in a prehension task, when no a priori information about the requirements of grasping action was available. Although it is known that simultaneous activation by observation and execution influences motor performance, the importance of the delays of these two events and the specific effect of movement observation itself (and not the prediction of the to-be-observed movement) on action performance are poorly known. Fine-grained kinematic analysis of both the transport and grasp components of the movement should provide knowledge about the influence of movement observation on the precision and the performance of the executed movement. The experiment involved two real participants who were asked to grasp a different side of a single object that was composed of a large and a small part. In the first experiment, we measured how the transport component and the grasp component were affected by movement observation. We tested whether this influence was greater if the observed movement occurred just before the onset of movement (200Â ms) or well before the onset of movement (1Â s). In a second experiment, to reproduce the previous experiment and to verify the specificity of the grasping movements, we also included a condition consisting of pointing towards the object. Both experiments showed two main results. A general facilitation of the transport component was found when observing a simultaneous action, independent of its congruency. Moreover, a specific facilitation of the grasp component was present during the observation of a congruent action when movement execution and observation were nearly synchronised. While the general facilitation may arise from a competition between the two participants as they reached for the object, the specific facilitation of the grasp component seems to be directly related to mirror neuron system activity induced by action observation itself. Moreover, the time course of the events appears to be an essential factor for this modulation, implying the transitory activation of the mirror neuron system
- âŠ