Detection Prospects for Majorana Fermion WIMPless Dark Matter

We consider both velocity-dependent and velocity-independent contributions to spin-dependent (SD) and spin-independent (SI) nuclear scattering (including one-loop corrections) of WIMPless dark matter, in the case where the dark matter candidate is a Majorana fermion. We find that spin-independent scattering arises only from the mixing of exotic squarks, or from velocity-dependent terms. Nevertheless (and contrary to the case of MSSM neutralino WIMPs), we find a class of models which cannot be detected through SI scattering, but can be detected at IceCube/DeepCore through SD scattering. We study the detection prospects for both SI and SD detection strategies for a large range of Majorana fermion WIMPless model parameters.Comment: 14 pages, 3 figures. v2: updated to match published versio

A geostatistical approach to multisensor rain field reconstruction and downscaling

International audienceA rain field reconstruction and downscaling methodology is presented, which allows suitable integration of large scale rainfall information and rain-gauge measurements at the ground. The former data set is assumed to provide probabilistic indicators that are used to infer the parameters of the probability density function of the stochastic rain process at each pixel site. Rain-gauge measurements are assumed as the ground truth and used to constrain the reconstructed rain field to the associated point values. Downscaling is performed by assuming the a posteriori estimates of the rain figures at each grid cell as the a priori large-scale conditioning values for reconstruction of the rain field at finer scale. The case study of an intense rain event recently observed in northern Italy is presented and results are discussed with reference to the modelling capabilities of the proposed methodology. Keywords: Reconstruction, downscaling, remote sensing, geostatistics, Meteosa

Natural risk assessment and decision planning for disaster mitigation

International audienceIn this paper, decisional models are introduced aiming at defining a general framework for natural disaster mitigation. More specifically, an integrated approach based on system modelling and optimal resource assignment is presented in order to support the decision makers in pre-operational and real-time management of forest fire emergencies. Some strategies for pre-operative and real time risk management will be described and formalized as optimal resource assignment problems. To this end, some models capable to describe the resources dynamics will be introduced, both in pre-operative phase and in real-time phase

Inhibition of acetylpolyamine and spermine oxidases by the polyamine analogue chlorhexidine

""Acetylpolyamine and spermine oxidases are involved in the catabolism of polyamines. The discovery of selective. inhibitors of these enzymes represents an important tool for the development of novel anti-neoplastic drugs. Here, a. comparative study on acetylpolyamine and spermine oxidases inhibition by the polyamine analogue chlorhexidine. is reported. Chlorhexidine is an antiseptic diamide, commonly used as a bactericidal and bacteriostatic agent.. Docking simulations indicate that chlorhexidine binding to these enzymes is compatible with the stereochemical. properties of both acetylpolyamine oxidase and spermine oxidase active sites. In fact, chlorhexidine is predicted. to establish several polar and hydrophobic interactions with the active site residues of both enzymes, with binding. energy values ranging from −7.6 to −10.6 kcal\\\/mol. In agreement with this hypothesis, inhibition studies indicate that. chlorhexidine behaves as a strong competitive inhibitor of both enzymes, values of Ki being 0.10 μM and 0.55 μM for. acetylpolyamine oxidase and spermine oxidase, respectively."

The distance to the Pleiades from orbital solution of the double-lined eclipsing binary HD 23642

Combining precise B,V photoelectric photometry and radial velocities, we have been able to derive a firm orbital solution and accurate physical parameters for the newly discovered eclipsing binary HD 23642 in the Pleiades open cluster. The resulting distance to the binary, and therefore to the cluster, is 132 +/- 2 pc. This closely confirms the distance modulus obtained by classical main sequence fitting methods (m-M = 5.60 or 132 pc), moving cluster techniques and the astrometric orbit of Atlas. This is the first time the distance to a member of the Pleiades is derived by orbital solution of a double-lined eclipsing binary, and it is intended to contribute to the ongoing discussion about the discordant Hipparcos distance to the cluster.Comment: accepted in press in A&A as Letter to the Edito

The 40s Omega-loop plays a critical role in the stability and the alkaline conformational transition of cytochrome c

The structural and redox properties of a non-covalent complex reconstituted upon mixing two non-contiguous fragments of horse cytochrome c, the residues 1 - 38 heme-containing N-fragment with the residues 57 - 104 C-fragment, have been investigated. With respect to native cyt c, the complex lacks a segment of 18 residues, corresponding, in the native protein, to an omega ( W)loop region. The fragment complex shows compact structure, native-like alpha-helix content but a less rigid atomic packing and reduced stability with respect to the native protein. Structural heterogeneity is observed at pH 7.0, involving formation of an axially misligated low-spin species and consequent partial displacement of Met80 from the sixth coordination position of the heme-iron. Spectroscopic data suggest that a lysine ( located in the Met80-containing loop, namely Lys72, Lys73, or Lys79) replaces the methionine residue. The residues 1 - 38/57 - 104 fragment complex shows an unusual biphasic alkaline titration characterized by a low (pK(a1)= 6.72) and a high pK(a)-associated state transition (pK(a2)= 8.56); this behavior differs from that of native cyt c, which shows a monophasic alkaline transition ( pK(a)= 8.9). The data indicate that the 40s Omega-loop plays an important role in the stability of cyt c and in ensuring a correct alkaline conformational transition of the protein

Collapse models with non-white noises II: particle-density coupled noises

We continue the analysis of models of spontaneous wave function collapse with stochastic dynamics driven by non-white Gaussian noise. We specialize to a model in which a classical "noise" field, with specified autocorrelator, is coupled to a local nonrelativistic particle density. We derive general results in this model for the rates of density matrix diagonalization and of state vector reduction, and show that (in the absence of decoherence) both processes are governed by essentially the same rate parameters. As an alternative route to our reduction results, we also derive the Fokker-Planck equations that correspond to the initial stochastic Schr\"odinger equation. For specific models of the noise autocorrelator, including ones motivated by the structure of thermal Green's functions, we discuss the qualitative and qantitative dependence on model parameters, with particular emphasis on possible cosmological sources of the noise field.Comment: Latex, 43 pages; versions 2&3 have minor editorial revision

Advanced e-Infrastructures for civil protection applications : the CYCLOPS project

During the full cycle of the emergency management, Civil Protection operative procedures involve many actors belonging to several institutions (civil protection agencies, public administrations, research centers, etc.) playing different roles (decision-makers, data and service providers, emergency squads, etc.). In this context the sharing of information is a vital requirement to make correct and effective decisions. Therefore a European-wide technologi- cal infrastructure providing a distributed and coordinated access to different kinds of resources (data, information, services, expertise, etc.) could enhance existing Civil Protection applications and even enable new ones. Such European Civil Protection e-Infrastructure should be designed taking into account the specific requirements of Civil Protection applications and the state-of-the-art in the scientific and technological disciplines which could make the emergency management more effective. In the recent years Grid technologies have reached a mature state providing a platform for secure and coordinated resource sharing between the participants collected in the so-called Virtual Organizations. Moreover the Earth and Space Sciences Informatics provide the conceptual tools for modeling the geospatial information shared in Civil Protection applications during its entire lifecycle. Therefore a European Civil Protection e-infrastructure might be based on a Grid platform enhanced with Earth Sciences services. In the context of the 6th Framework Programme the EU co-funded Project CYCLOPS (CYber-infrastructure for CiviL protection Operative ProcedureS), ended in December 2008, has addressed the problem of defining the re- quirements and identifying the research strategies and innovation guidelines towards an advanced e-Infrastructure for Civil Protection. Starting from the requirement analysis CYCLOPS has proposed an architectural framework for a European Civil Protection e-Infrastructure. This architectural framework has been evaluated through the development of prototypes of two operative applications used by the Italian Civil Protection for Wild Fires Risk Assessment (RISICO) and by the French Civil Protection for Flash Flood Risk Management (SPC-GD). The results of these studies and proof-of-concepts have been used as the basis for the definition of research and innovation strategies aiming to the detailed design and implementation of the infrastructure. In particular the main research themes and topics to be addressed have been identified and detailed. Finally the obstacles to the innovation required for the adoption of this infrastructure and possible strategies to overcome them have been discussed

The key role played by charge in the interaction of cytochrome c with cardiolipin

Cytochrome c undergoes structural variations upon binding of cardiolipin, one of the phospholipids constituting the mitochondrial membrane. Although several mechanisms governing cytochrome c/cardiolipin (cyt c/CL) recognition have been proposed, the interpretation of the process remains, at least in part, unknown. To better define the steps characterizing the cyt c-CL interaction, the role of Lys72 and Lys73, two residues thought to be important in the protein/lipid binding interaction, were recently investigated by mutagenesis. The substitution of the two (positively charged) Lys residues with Asn revealed that such mutations cancel the CL-dependent peroxidase activity of cyt c; furthermore, CL does not interact with the Lys72Asn mutant. In the present paper, we extend our study to the Lys → Arg mutants to investigate the influence exerted by the charge possessed by the residues located at positions 72 and 73 on the cyt c/CL interaction. On the basis of the present work a number of overall conclusions can be drawn: (i) position 72 must be occupied by a positively charged residue to assure cyt c/CL recognition; (ii) the Arg residues located at positions 72 and 73 permit cyt c to react with CL; (iii) the replacement of Lys72 with Arg weakens the second (low-affinity) binding transition; (iv) the Lys73Arg mutation strongly increases the peroxidase activity of the CL-bound protein