On arithmetic detection of grey pulses with application to Hawking radiation

Micron-sized black holes do not necessarily have a constant horizon temperature distribution. The black hole remote-sensing problem means to find out the `surface' temperature distribution of a small black hole from the spectral measurement of its (Hawking) grey pulse. This problem has been previously considered by Rosu, who used Chen's modified Moebius inverse transform. Here, we hint on a Ramanujan generalization of Chen's modified Moebius inverse transform that may be considered as a special wavelet processing of the remote-sensed grey signal coming from a black hole or any other distant grey sourceComment: 5 pages, published versio

The European Solar Radiation Atlas: a valuable digital tool

International audienceThe new CD-ROM based European Solar Radiation Atlas (ESRA) is now available. It is published by Les Presses de l'Ecole des Mines de Paris on behalf of the European Commission. This atlas, in 2 volumes, is an instrument dedicated to providing knowledge and aiding exploitation of the solar resources across a wide sweep of Europe, from the Urals to the Azores and from Northern Africa to Polar Circle. It is a powerful tool for architects, engineers, meteorologists, agronomists, local authorities, and tourism professionals, as well as for researchers and students. The input data are based on the period 1981-1990

Symbolic Reachability Analysis of Genetic Regulatory Networks using Qualitative Abstractions

The switch-like character of gene regulation has motivated the use of hybrid, discrete-continuous models of genetic regulatory networks. While powerful techniques for the analysis, verification, and control of hybrid systems have been developed, the specificities of the biological application domain pose a number of challenges, notably the absence of quantitative information on parameter values and the size and complexity of networks of biological interest. We introduce a method for the analysis of reachability properties of genetic regulatory networks that is based on a class of discontinuous piecewise-affine (PA) differential equations well-adapted to the above constraints. More specifically, we introduce a hyperrectangular partition of the state space that forms the basis for a discrete abstraction preserving the sign of the derivatives of the state variables. The resulting discrete transition system provides a conservative approximation of the qualitative dynamics of the network and can be efficiently computed in a symbolic manner from inequality constraints on the parameters. The method has been implemented in the computer tool Genetic Network Analyzer (GNA), which has been applied to the analysis of a regulatory system whose functioning is not well-understood by biologists, the nutritional stress response in the bacterium Escherichia coli

Pulse Rate Analysis in Case of Central Sleep Apnea: A New Algorithm for Cardiac Rate Estimation

Annual International Conference of the IEEEInternational audienceThis paper first describes the AM-FM demodulation of an arterial pressure signal. Although it is known to be efficient on signals modulated by breathing, we demonstrate that in case of lack of respiratory modulation (central sleep apnea), the AM-FM algorithm doesn't perform well in heart rate extraction. We introduce then a new algorithm based on Singular Spectrum Analysis eigen values which performs better cardiac frequency estimation in this context. The error for cardiac frequency estimation is around 0.2 BPM (Beats Per Minute) versus 5.5 BPM for the AM-FM demodulation. Further experimentations will be performed (with this time both cardiac and respiratory assessments) and will deal with real sleep apnea cases

Investigation of T cell-mediated immune surveillance against tumor-specific antigens in genetically engineered mouse models of cancer

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Biology, 2011.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from student-submitted PDF version of thesis. Vita.Includes bibliographical references.The association of tumor cells and lymphocytes has led to the hypothesis that our immune system actively inhibits the formation and progression of cancer, a phenomenon called tumor immune surveillance. T cells specific to mutant proteins have been identified in cancer patients and the recent success of cancer immunotherapies provides evidence that the immune system can fight this disease. Yet the frequent occurrence of malignant disease despite T cell recognition presents a significant medical problem. Only after we determine how tumors bypass the immune system can immunotherapeutic approaches be improved. To understand how tumors subvert immune responses, tumor transplantation or transgenic mice expressing tumor-associated antigens have been used to model cancer. To assess the role of anti-tumor T cells in models that more accurately reflect the human disease, I developed new systems to introduce exogenous antigens, to mimic neoantigens, into genetically engineered mouse models of lung cancer and sarcomas. Utilizing the mouse model of lung cancer, I show that endogenous T cells respond to and infiltrate lung tumors, delaying malignant progression. Despite continued antigen expression, T cell infiltration does not persist and tumors ultimately escape immune attack. Transplantation of cell lines derived from lung tumors that express these antigens or prophylactic vaccination against autochthonous tumors, however, results in rapid tumor eradication or selection of tumors that lose antigen expression. These results support clinical data that suggest a role for the immune system in cancer suppression rather than prevention. Tumor immune surveillance and immunoediting have largely been defined using carcinogen-driven models of sarcomagenesis. Using a genetically engineered model of sarcomagenesis, I show that immunoediting requires potent T cell antigens and that lymphocytes drive the evolution of less immunogenic tumors by selecting for antigen loss. Finally, immunotherapies have historically been ineffective in treating cancer patients. I show that vaccination against specific antigens expressed in mouse lung cancers leads to sustained anti-tumor T cell responses that eradicate recently initiated tumors. Vaccination also stimulates anti-tumor T cell responses in an antigen-independent fashion by enhancing the expansion and activity of T cells that recognize antigens only expressed in tumors.by Michel Justin Porter Du Page.Ph.D