A combined analysis technique for the search for fast magnetic monopoles with the MACRO detector

We describe a search method for fast moving ($\beta > 5 \times 10^{-3}$) magnetic monopoles using simultaneously the scintillator, streamer tube and track-etch subdetectors of the MACRO apparatus. The first two subdetectors are used primarily for the identification of candidates while the track-etch one is used as the final tool for their rejection or confirmation. Using this technique, a first sample of more than two years of data has been analyzed without any evidence of a magnetic monopole. We set a 90% CL upper limit to the local monopole flux of $1.5 \times 10^{-15} cm^{-2} s^{-1} sr^{-1}$ in the velocity range $5 \times 10^{-3} \le \beta \le 0.99$ and for nucleon decay catalysis cross section smaller than $\sim 1 mb$.Comment: 29 pages (12 figures). Accepted by Astroparticle Physic

Final results of magnetic monopole searches with the MACRO experiment

We present the final results obtained by the MACRO experiment in the search for GUT magnetic monopoles in the penetrating cosmic radiation, for the range $4\times 10^{-5}< \beta < 1$. Several searches with all the MACRO sub-detectors (i.e. scintillation counters, limited streamer tubes and nuclear track detectors) were performed, both in stand alone and combined ways. No candidates were detected and a 90% Confidence Level (C.L.) upper limit to the local magnetic monopole flux was set at the level of $1.4\times 10^{-16}$ cm$^{-2}$ s$^{-1}$ sr$^{-1}$. This result is the first experimental limit obtained in direct searches which is well below the Parker bound in the whole $\beta$ range in which GUT magnetic monopoles are expected.Comment: 12 pages, Latex, 9 figures and 2 Table

The Observation of Up-going Charged Particles Produced by High Energy Muons in Underground Detectors

An experimental study of the production of up-going charged particles in inelastic interactions of down-going underground muons is reported, using data obtained from the MACRO detector at the Gran Sasso Laboratory. In a sample of 12.2 10^6 single muons, corresponding to a detector livetime of 1.55 y, 243 events are observed having an up-going particle associated with a down-going muon. These events are analysed to determine the range and emission angle distributions of the up-going particle, corrected for detection and reconstruction efficiency. Measurements of the muon neutrino flux by underground detectors are often based on the observation of through-going and stopping muons produced in $\nu_\mu$ interactions in the rock below the detector. Up-going particles produced by an undetected down-going muon are a potential background source in these measurements. The implications of this background for neutrino studies using MACRO are discussed.Comment: 18 pages, 9 figures. Accepted by Astrop. Physic

Nuclearite search with the MACRO detector at Gran Sasso

In this paper we present the results of a search for nuclearites in the penetrating cosmic radiation using the scintillator and track-etch subdetectors of the MACRO apparatus. The analyses cover the beta =v/c range at the detector depth (3700 hg/cm^2) 10^-5 < beta < 1; for beta = 2 x 10^-3 the flux limit is 2.7 x 10^-16 cm^-2 s^-1 sr^-1 for an isotropic flux of nuclearites, and twice this value for a flux of downgoing nuclearites.Comment: 16 pages, 4 Encapsulated Postscript figures, uses article.sty. Submitted to The European Physical Journal

Atmospheric neutrino induced muons in the MACRO detector

A measurement of the flux of neutrino-induced muons using the MACRO detector is presented. Different event topologies, corresponding to different neutrino parent energies can be detected. The upward throughgoing muon sample is the larger event sample. The observed upward-throughgoing muons are 26% fewer than expected and the zenith angle distribution does not fit with the expected one. Assuming neutrino oscillations, both measurements suggest maximum mixing and Dm2 of a few times 10-3 eV2. The other samples are due to the internally produced events and to upward-going stopping muons. These data show a regular deficit of observed events in each angular bin, as expected assuming neutrino oscillations with maximum mixing, in agreement with the analysis of the upward-throughgoing muon sample.Comment: 7 pages 6 figures to appear in the proceedings of XVIII International Conference on Neutrino Physics and Astrophysics (Neutrino'98), Takayama, Japan 4-9 June, 199

New MACRO results on atmospheric neutrino oscillations

The final results of the MACRO experiment on atmospheric neutrino oscillations are presented and discussed. The data concern different event topologies with average neutrino energies of ~3 and ~50 GeV. Multiple Coulomb Scattering of the high energy muons in absorbers was used to estimate the neutrino energy of each event. The angular distributions, the L/E_nu distribution, the particle ratios and the absolute fluxes all favour nu_mu --> nu_tau oscillations with maximal mixing and Delta m^2 =0.0023 eV^2. A discussion is made on the Monte Carlos used for the atmospheric neutrino flux. Some results on neutrino astrophysics are also briefly discussed.Comment: Invited Paper at the NANP03 Int. Conf., Dubna, 200

Evolutionary Epidemiology of Drug-Resistance in Space

The spread of drug-resistant parasites erodes the efficacy of therapeutic treatments against many infectious diseases and is a major threat of the 21st century. The evolution of drug-resistance depends, among other things, on how the treatments are administered at the population level. “Resistance management” consists of finding optimal treatment strategies that both reduce the consequence of an infection at the individual host level, and limit the spread of drug-resistance in the pathogen population. Several studies have focused on the effect of mixing different treatments, or of alternating them in time. Here, we analyze another strategy, where the use of the drug varies spatially: there are places where no one receives any treatment. We find that such a spatial heterogeneity can totally prevent the rise of drug-resistance, provided that the size of treated patches is below a critical threshold. The range of parasite dispersal, the relative costs and benefits of being drug-resistant compared to being drug-sensitive, and the duration of an infection with drug-resistant parasites are the main factors determining the value of this threshold. Our analysis thus provides some general guidance regarding the optimal spatial use of drugs to prevent or limit the evolution of drug-resistance

Development and preliminary validation of a Greek-language outpatient satisfaction questionnaire with principal components and multi-trait analyses

BACKGROUND: In the recent years there is a growing interest in Greece concerning the measurement of the satisfaction of patients who are visiting the outpatient clinics of National Health System (NHS) general acute hospitals. The aim of this study is therefore to develop a patient satisfaction questionnaire and provide its preliminary validation. METHODS: A questionnaire in Greek has been developed by literature review, researchers' on the spot observation and interviews. Pretesting has been followed by telephone surveys in two short-term general NHS hospitals in Macedonia, Greece. A proportional stratified random sample of 285 subjects and a second random sample of 100 outpatients, drawn on March 2004, have been employed for the analysis. These have resulted in scale creation via Principal Components Analysis and psychometric testing for internal consistency, test-retest and interrater reliability as well as construct validity. RESULTS: Four summated scales have emerged regarding the pure outpatient component of the patients' visits, namely medical examination, hospital environment, comfort and appointment time. Cronbach's alpha coefficients and Pearson, Spearman and intraclass correlations indicate a high degree of scale reliability and validity. Two other scales -lab appointment time and lab experience- capture the apparently distinct yet complementary visitor experience related to the radiographic and laboratory tests. Psychometric tests are equally promising, however, some discriminant validity differences lack statistical significance. CONCLUSION: The instrument appears to be reliable and valid regarding the pure outpatient experience, whereas more research employing larger samples is required in order to establish the apparent psychometric properties of the complementary radiographic and laboratory-testing process, which is only relevant to about 25% of the subjects analysed here

Adult Consequences of Late Adolescent Alcohol Consumption: A Systematic Review of Cohort Studies

In a systematic review of cohort studies of adolescent drinking and later outcomes, Jim McCambridge and colleagues show that although studies suggest links to worse adult physical and mental health and social consequences, existing evidence is of poor quality