MACRO constraints on violation of Lorentz invariance

The energy spectrum of neutrino-induced upward-going muons in MACRO has been analysed in terms of relativity principles violating effects, keeping standard mass-induced atmospheric neutrino oscillations as the dominant source of $\nu_{\mu} \to \nu_{\tau}$ transitions. The data disfavor these exotic possibilities even at a sub-dominant level, and stringent 90% C.L. limits are placed on the Lorentz invariance violation parameter $|\Delta v| < 6 \times 10^{-24}$ at $\sin 2{\theta}_v$ = 0 and $|\Delta v| < 2.5 \div 5 \times 10^{-26}$ at $\sin 2{\theta}_v$ = $\pm$1. These limits can also be re-interpreted as upper bounds on the parameters describing violation of the Equivalence Principle.Comment: 3 pages, 2 figures. Presented at NOW 2006: Neutrino Oscillation Workshop, Conca Specchiulla, Otranto, Italy, Sep 2006. To be published in Nucl. Phys. B (Proc. Suppl.

Welfare assessment: correlations and integration between a Qualitative Behavioural Assessment and a clinical/health protocol applied in veal calves farms

This study is aimed at finding correlations and possible integration among Qualitative Behavioural Assessment (QBA) and a specific protocol of clinical/health evaluation. Both welfare assessment methods were based on direct animal observation and were applied in 24 Italian veal calves farms at 3 weeks (wks) of rearing. Principal component analysis (PCA) summarized 20 QBA descriptors on two main components (PC1 and PC2) with eigenvalues above 4 and explaining 29.6 and 20.3% of the variation respectively. PCA on residuals obtained after correcting for housing condition yielded highly similar results, indicating that the rearing environment of the calves was not an important determinant of the observer reliability of QBA. A relationship was found between QBA PC2 and the presence of signs of cross-sucking recorded during the clinical visit (presence PC2=1.11 vs. absence PC2=-1.55,

Posttransplant lymphoproliferative disorders in neuronal xenotransplanted macaques

Posttransplant lymphoproliferative disorders (PTLDs) are a heterogeneous group of lymphoid proliferations that occur in the setting of depressed T-cell function due to immunosuppressive therapy used following solid organ transplantation, hematopoietic stem cell transplantation, and also xenotransplantation. In the present study, 28 immunosuppressed parkinsonian Macaca fascicularis were intracerebrally injected with wild-type or CTLA4-Ig transgenic porcine xenografts to identify a suitable strategy to enable long-term cell survival, maturation, and differentiation. Nine of 28 (32%) immunosuppressed primates developed masses compatible with PTLD, located mainly in the gastrointestinal tract and/or nasal cavity. The masses were classified as monomorphic PTLD according to the World Health Organization classification. Immunohistochemistry and polymerase chain reaction (PCR) analyses revealed that the PTLDs were associated with macaca lymphocryptovirus as confirmed by double-labeling immunohistochemistry for CD20 and Epstein-Barr nuclear antigen 2 (EBNA-2), where the viral protein was located within the CD20+ neoplastic B cells. In sera from 3 distinct phases of the experimental life of the primates, testing by quantitative PCR revealed a progression of the viral load that paralleled the PTLD progression and no evidence of zoonotic transmission of porcine lymphotropic herpesvirus through xenoneuronal grafts. These data suggest that monitoring the variation of macaca lymphocryptovirus DNA in primates could be used as a possible early diagnostic tool for PTLD progression, allowing preemptive treatment such as immunosuppression therapy reduction

Preliminary Considerations from the 2nd Phase of Experiments at the SIET/SWAM Facility

Severe accident codes study the thermo-hydraulics of the suppression chamber with a limited numbers of nodes, generally solving mass and energy equations and assuming perfect mixing conditions. In a long station black out the effect of the sparger’s design might create local phenomena (e.g. stratification, hot-spots) which are hardly predicted by the current practices, resulting in mispredictions of the containment pressure evolution. In order to understand the effect of the sparger geometry, steam mass flux, water sub-cooling and air concentration the SWAM facility (Steam Water Air Mixing) at the SIET laboratory was employed performing around twenty different experiments, in conditions close to what is expected during the Fukushima Daiichi accident. The test facility (poll and pipes) is built with polycarbonate (transparent material) to ease the acquisition of the standard and high-speed cameras. Vertically distributed thermocouples and high-frequency pressure measurements are employed to obtain quantitative values for phenomena investigation and future CFD validations. It was shown that experiments with pure steam and relatively large diameter holes induce chugging that enhances mixing in the pool. Once chugging ceases, because of the reduced sub-cooling, a hot water layer is created in the upper part of the pool. The presence of air in the pipe induces large stratification from the condition of large subcooling because of the limited mixing introduced in the region below the pipe mouth

Search for Intermediate Mass Magnetic Monopoles and Nuclearites with the SLIM experiment

SLIM is a large area experiment (440 m2) installed at the Chacaltaya cosmic ray laboratory since 2001, and about 100 m2 at Koksil, Himalaya, since 2003. It is devoted to the search for intermediate mass magnetic monopoles (107-1013 GeV/c2) and nuclearites in the cosmic radiation using stacks of CR39 and Makrofol nuclear track detectors. In four years of operation it will reach a sensitivity to a flux of about 10-15 cm-2 s-1 sr-1. We present the results of the calibration of CR39 and Makrofol and the analysis of a first sample of the exposed detector.Comment: Presented at the 22nd ICNTS, Barcelona 200

Experimental Observation of Non-Ideal Nozzle Flow of Siloxane Vapor MDM

The first experimental results from the Test-Rig for Organic Vapors (TROVA) at Politecnico di Milano are reported. The facility implements an Organic Rankine Cycle (ORC) where the expansion process takes place within a straight axis convergent-divergent nozzle, which is the simplest geometry representative of an ORC turbine blade passage. In order to reduce the required input thermal power, a batch operating mode was selected for the plant. Experimental runs with air allowed to verify the throttling valve operation and the measurement techniques, which include total pressure and temperature measurements in the settling chamber, static pressure measurements along the nozzle axis. A double-passage Schlieren technique is used to visualize the flow field in the nozzle throat and divergent section and to determine the position of shock waves within the flow field. The first experimental observation of non-ideal nozzle flows are presented for the expansion of siloxane fluid MDM (C8H24O2Si3, octamethyltrisiloxane) for vapor expansion in the close proximity of the liquid-vapor saturation curve, at relatively low pressure of operation. A supersonic flow is attained within the divergent section of the nozzle, as demonstrated by the observation of an oblique shock wave at the throat section, where a 0.1 mm recessed step is located. Schlieren visualizations are limited by the occurrence of condensation along the mirror side of the nozzle. Pressure measurements are compatible with the observed flow field

Search for strange quark matter and Q-balls with the SLIM experiment

We report on the search for Strange Quark Matter (SQM) and charged Q-balls with the SLIM experiment at the Chacaltaya High Altitude Laboratory (5230 m a.s.l.) from 2001 to 2005. The SLIM experiment was a 427 m$^{2}$ array of Nuclear Track Detectors (NTDs) arranged in modules of $24 \times 24$ cm$^{2}$ area. SLIM NTDs were exposed to the cosmic radiation for 4.22 years after which they were brought back to the Bologna Laboratory where they were etched and analyzed. We estimate the properties and energy losses in matter of nuclearites (large SQM nuggets), strangelets (small charged SQM nuggets) and Q-balls; and discuss their detection with the SLIM experiment. The flux upper limits in the CR of such downgoing particles are at the level of $1.3 10^{-15}$/cm$^{2}$/s/sr (90% CL).Comment: 4 pages, 7 eps figures. Talk given at the 24th International Conference on Nuclear Tracks in Solids, Bologna, Italy, 1-5 September 200

Time variations in the deep underground muon flux measured by MACRO

More than 30 million of high-energy muons collected with the MACRO detector at the underground Gran Sasso Laboratory have been used to search for flux variations of different natures. Two kinds of studies were carried out: search for periodic variations and for the occurrence of clusters of events. Different analysis methods, including Lomb-Scargle spectral analysis and Scan Test statistics have been applied to the data.Comment: 6 pages, 4 EPS figures. Talk given at the 29th ICRC, Pune, India, 3-10 August 200

Electron/pion separation with an Emulsion Cloud Chamber by using a Neural Network

We have studied the performance of a new algorithm for electron/pion separation in an Emulsion Cloud Chamber (ECC) made of lead and nuclear emulsion films. The software for separation consists of two parts: a shower reconstruction algorithm and a Neural Network that assigns to each reconstructed shower the probability to be an electron or a pion. The performance has been studied for the ECC of the OPERA experiment [1]. The $e/\pi$ separation algorithm has been optimized by using a detailed Monte Carlo simulation of the ECC and tested on real data taken at CERN (pion beams) and at DESY (electron beams). The algorithm allows to achieve a 90% electron identification efficiency with a pion misidentification smaller than 1% for energies higher than 2 GeV

Nuclear Track Detectors for Environmental Studies and Radiation Monitoring

Several improvements were made for Nuclear Track Detectors (NTDs) used for environmental studies and for particle searches. A new method was used to determine the bulk etch rate of CR39 and Makrofol NTDs. It is based on the simultaneous measurement of the diameter and of the height of etch-pit cones caused by relativistic heavy ions (158 A GeV Pb(82+) and In(49+) ions) and their fragments. The use of alcohol in the etching solution improves the surface quality of NTDs and it raises their thresholds. The detectors were used for the determination of nuclear fragmentation cross sections of Iron and Silicon ions of 1.0 and 0.41 GeV/nucleon. These measurements are important for the determination of doses in hadron therapy and for doses received by astronauts. The detectors were also used in the search of massive particles in the cosmic radiation, for the determination of the mass spectrum of cosmic rays and for the evaluation of Po(210) alpha decay and of natural radon concentrations.Comment: 7 pages, 5 EPS figures. Presented at the 10th Topical Seminar on Innovative Particle and Radiation Detectors, 1-5 October 2006, Siena, Ital