773 research outputs found

    Physics Beyond the Standard Model: Focusing on the Muon Anomaly

    Full text link
    We present a model based on the implication of an exceptional E_{6}-GUT symmetry for the anomalous magnetic moment of the muon. We follow a particular chain of breakings with Higgses in the 78 and 351 representations. We analyse the radiative correction contributions to the muon mass and the effects of the breaking of the so-called Weinberg symmetry. We also estimate the range of values of the parameters of our model.Comment: 14 RevTeX pages, 5 figure

    A possible origin of superconducting currents in cosmic strings

    Get PDF
    The scattering and capture of right-handed neutrinos by an Abelian cosmic string in the SO(10) grand unification model are considered. The scattering cross-section of neutrinos per unit length due to the interaction with the gauge and Higgs fields of the string is much larger in its scaling regime than in the friction one because of the larger infrared cutoff of the former.The probability of capture in a zero mode of the string accompanied by the emission of a gauge or Higgs boson shows a resonant peak for neutrino momentum of the order of its mass. Considering the decrease of number of strings per unit comoving volume in the scaling epoch the cosmological consequences of the superconducting strings formed in this regime will be much smaller than those which could be produced already in the friction one.Comment: 14 pages Latex, 4 figues/ep

    Hand disinfection in a neonatal intensive care unit: continuous electronic monitoring over a one-year period

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Good hand hygiene compliance is essential to prevent nosocomial infections in healthcare settings. Direct observation of hand hygiene compliance is the gold standard but is time consuming. An electronic dispenser with built-in wireless recording equipment allows continuous monitoring of its usage. The purpose of this study was to monitor the use of alcohol-based hand rub dispensers with a built-in electronic counter in a neonatal intensive care unit (NICU) setting and to determine compliance with hand hygiene protocols by direct observation.</p> <p>Methods</p> <p>A one-year observational study was conducted at a 27 bed level III NICU at a university hospital. All healthcare workers employed at the NICU participated in the study. The use of bedside dispensers was continuously monitored and compliance with hand hygiene was determined by random direct observations.</p> <p>Results</p> <p>A total of 258,436 hand disinfection events were recorded; i.e. a median (interquartile range) of 697 (559–840) per day. The median (interquartile range) number of hand disinfection events performed per healthcare worker during the day, evening, and night shifts was 13.5 (10.8 - 16.7), 19.8 (16.3 - 24.1), and 16.6 (14.2 - 19.3), respectively. In 65.8% of the 1,168 observations of patient contacts requiring hand hygiene, healthcare workers fully complied with the protocol.</p> <p>Conclusions</p> <p>We conclude that the electronic devices provide useful information on frequency, time, and location of its use, and also reveal trends in hand disinfection events over time. Direct observations offer essential data on compliance with the hand hygiene protocol. In future research, data generated by the electronic devices can be supplementary used to evaluate the effectiveness of hand hygiene promotion campaigns.</p

    Suzaku X-Ray Imaging and Spectroscopy of Cassiopeia A

    Full text link
    Suzaku X-ray observations of a young supernova remnant, Cassiopeia A, were carried out. K-shell transition lines from highly ionized ions of various elements were detected, including Chromium (Cr-Kalpha at 5.61 keV). The X-ray continuum spectra were modeled in the 3.4--40 keV band, summed over the entire remnant, and were fitted with a simplest combination of the thermal bremsstrahlung and the non-thermal cut-off power-law models. The spectral fits with this assumption indicate that the continuum emission is likely to be dominated by the non-thermal emission with a cut-off energy at > 1 keV. The thermal-to-nonthermal fraction of the continuum flux in the 4-10 keV band is best estimated as ~0.1. Non-thermal-dominated continuum images in the 4--14 keV band were made. The peak of the non-thermal X-rays appears at the western part. The peak position of the TeV gamma-rays measured with HEGRA and MAGIC is also shifted at the western part with the 1-sigma confidence. Since the location of the X-ray continuum emission was known to be presumably identified with the reverse shock region, the possible keV-TeV correlations give a hint that the accelerated multi-TeV hadrons in Cassiopeia A are dominated by heavy elements in the reverse shock region.Comment: Publ. Astron. Soc. Japan 61, pp.1217-1228 (2009

    Risk factors for lateral meniscus posterior root tears in the anterior cruciate ligament injured knee: an epidemiological analysis of 3956 patients from the SANTI database

    Get PDF
    Background: Lateral meniscal posterior root tears (LMPRT) result in loss of hoop forces and significant increases in tibiofemoral contact pressures. Pre-operative imaging lacks reliability and therefore holding an appropriate index of suspicion, based on the epidemiology and risk factors for LMPRT, may reduce the rate of missed diagnoses. Hypothesis/Purpose: The primary objectives of this study were to evaluate the incidence and risk factors for lateral meniscus root lesions in a large series of patients undergoing anterior cruciate ligament (ACL) reconstruction. Study Design: Case series. Methods: All patients who underwent primary or revision ACL reconstruction, between January 2011 to April 2018 were considered for study eligibility. From this overall population, all patients who underwent repair of a lateral meniscus posterior root tear (LMPRT) were identified. The epidemiology of LMPRT was defined by the incidence within the study population, stratified by key demographic parameters. Potentially important risk factors for the presence of LMPRT were evaluated in multivariate logistic regression analysis. Results: 3956 patients undergoing ACL reconstruction were included in the study. A LMPRT was identified and repaired in 262 patients (6.6%). Multivariate analyses demonstrated that significant risk factors for LMPRT included a contact sports injury mechanism (7.8% incidence with contact sports mechanism vs 4.5% with non-contact mechanism 4.5%; OR = 1.69, IC95% 1.266 - 2.285; P <.001) and the presence of a medial meniscal tear (7.9% incidence with medial meniscal tear vs 5.8% in those without; OR = 1.532, IC95% 1.185 - 1.979; P <.001). Although the incidence of LMPRT in male patients (7.3%) was higher than females (4.8%) this was not significant in multivariate analysis (P = 0.270). Patient age, revision ACL reconstruction and a pre-operative side to side laxity difference of ≥ 6mm were not found to be significant risk factors for LMPRT. Conclusion: The incidence of LMPRT was 6.6% in a large series of patients undergoing ACL reconstruction. Participation in contact sports and the presence of a concomitant medial meniscal tear were demonstrated to be important independent risk factors. Their presence should raise the index of suspicion of this injury pattern

    Insignificant impact of prescribed fire on surface soil in a Pinus pinaster plantation, northern Portugal

    Get PDF
    Following a prescribed fire in a Pinus pinaster forest site located in the north-west Portugal, monitoring of any changes in selected soil characteristics and soil hydrology was undertaken to assess the effects of burning on the following: pH, electrical conductivity, water content, organic carbon and porosity. Thirty plots were established on a regular grid. At each sample plot before and after the fire, samples were collected (disturbed samples from depths of 0-1cm and 1-5cm; undisturbed core samples from 0-5cm). The results indicate that there was no measurable impact on the properties of the soil following this carefully conducted prescribed fire. The fire only affected the litter layer, as intended. Confirmation of this minimal impact on the soil was provided by regrowth of grasses and herbs already occurring two months after the fire. The implication is, therefore, that provided this wildfire-risk reduction strategy is carried out under existing strict guidelines, any impact on soil quality will be minimal

    The Spiderweb galaxy: a forming massive cluster galaxy at z~2

    Get PDF
    We present a deep image of the radio galaxy MRC 1138-262 taken with the Hubble Space Telescope (HST) at a redshift of z = 2.2. The galaxy is known to have properties of a cD galaxy progenitor and be surrounded by a 3 Mpc-sized structure, identified with a protocluster. The morphology shown on the new deep HST/ACS image is reminiscent of a spider's web. More than 10 individual clumpy features are observed, apparently star-forming satellite galaxies in the process of merging with the progenitor of a dominant cluster galaxy 11 Gyr ago. There is an extended emission component, implying that star formation was occurring over a 50 times 40 kpc region at a rate of more than 100 M_sun/yr. A striking feature of the newly named ``Spiderweb galaxy'' is the presence of several faint linear galaxies within the merging structure. The dense environments and fast galaxy motions at the centres of protoclusters may stimulate the formation of these structures, which dominate the faint resolved galaxy populations in the Hubble Ultra Deep Field. The new image provides a unique testbed for simulations of forming dominant cluster galaxies.Comment: 5 pages, 2 figures (reduced to grayscale); ApJ Letter

    Different susceptibility of osteosarcoma cell lines and primary cells to treatment with oncolytic adenovirus and doxorubicin or cisplatin

    Get PDF
    Despite improvements in treatment regimens for osteosarcoma (OS) patients, survival rate has not increased over the last two decades. New treatment modalities are therefore warranted. Preclinical results with conditionally replicative adenoviruses (CRAds) to treat OS are promising. One type of CRAd that was effective against OS cells is Ad5-Δ24RGD. In other types of cancer, CRAds have been shown to interact synergistically with chemotherapeutic agents. Chemotherapy for OS often includes doxorubicin and cisplatin. Therefore, we explored combination treatment of OS cell lines and primary OS cell cultures with Ad5-Δ24RGD and doxorubicin or cisplatin. On OS cell lines, combination treatment was additive to synergistic. Surprisingly, however, on seven of eight primary OS samples no such combination effects were observed. In contrast, in many cases chemotherapy even inhibited CRAd-mediated cell killing. The inhibitory effect of doxorubicin on Ad5-Δ24RGD in primary OS cells appeared to correlate with slow cell growth rate; reduced viral replication and absence of chemotherapy-induced G2 cell cycle arrest. Our results point to the possibility that, at least for OS, virotherapy and chemotherapy should best not be performed simultaneously. In general, our work underscores the importance of testing new genetic anticancer agents and treatment regimens on primary cancer specimens

    Architectural model for interoperability between healthcare service providers in Colombia

    Get PDF
    En la actualidad Gobiernos, IPS y desarrolladores de software enfrentan la necesidad de mejorar la eficiencia de los sistemas de información en salud mediante una adecuada gestión de la información y la implementación de TICS. Una de las áreas de interés, es el desarrollo de perfiles de interoperabilidad que permita intercambiar información y mejorar la colaboración entre los diferentes actores del sistema de salud. El objetivo del presente artículo es definir y validar un modelo arquitectónico de interoperabilidad entre sistemas de información de IPS en Colombia. El modelo, sustentando en normatividad Colombiana, sugiere el uso de SOA como referencia para definir la arquitectura software y el estándar HL7 para el intercambio de mensajes y documentos clínicos. Posteriormente se evalúa el modelo mediante un grupo de profesionales con experiencia en desarrollo de sistemas de información y una prueba piloto basada en dos escenarios de interoperabilidad en tres IPS de Popayán. El modelo busca aportar una metodología de modelamiento y desarrollo de software en IPS y empresas desarrolladoras, mejorando así el nivel de entendimiento y control sobre las transacciones de información presentes en la prestación de servicios.Nowadays governments, health services organizations and software developers face the need to improve the efficiency of information systems in health through information management and ICT implementation. One of the areas of interest is the development of interoperability profiles that allow exchange information and improve collaboration between different actors in the health system. The aim of this paper is to define and validate an architectural model of interoperability between information systems on IPS in Colombia. The model, grounded in Colombian legislation, suggests the use of SOA as a reference to define the software architecture and HL7 standard for the exchange of messages and clinical documents. Subsequently the model is evaluated by a group of professionals with experience in information systems development and piloted based on two interoperability scenarios in three IPS of Popayán. The model aims to provide a methodology for software modeling and development among health services organizations, improving the level of understanding and control over information transactions present in the delivery of services
    • …
    corecore