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This Letter reports on a search for nu(mu) --> nu(e) transitions by the MINOS experiment based on a 3.14x10(20) protons-on-target exposure in the Fermilab NuMI beam. We observe 35 events in the Far Detector with a background of 27+/-5(stat)+/-2(syst) events predicted by the measurements in the Near Detector. If interpreted in terms of nu(mu) --> nu(e) oscillations, this 1.5sigma excess of events is consistent with sin2(2theta(13)) comparable to the CHOOZ limit when |Delta m2|=2.43x10(-3) eV2 and sin2(2theta(23))=1.0 are assumed.
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We report the first detailed comparisons of the rates and spectra of neutral-current neutrino interactions at two widely separated locations. A depletion in the rate at the far site would indicate mixing between nu(mu) and a sterile particle. No anomalous depletion in the reconstructed energy spectrum is observed. Assuming oscillations occur at a single mass-squared splitting, a fit to the neutral- and charged-current energy spectra limits the fraction of nu(mu) oscillating to a sterile neutrino to be below 0.68 at 90% confidence level. A less stringent limit due to a possible contribution to the measured neutral-current event rate at the far site from nu(e) appearance at the current experimental limit is also presented.
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A search for a sidereal modulation in the MINOS near detector neutrino data was performed. If present, this signature could be a consequence of Lorentz and CPT violation as predicted by the effective field theory called the standard-model extension. No evidence for a sidereal signal in the data set was found, implying that there is no significant change in neutrino propagation that depends on the direction of the neutrino beam in a sun-centered inertial frame. Upper limits on the magnitudes of the Lorentz and CPT violating terms in the standard-model extension lie between 10(-4) and 10(-2) of the maximum expected, assuming a suppression of these signatures by a factor of 10(-17).
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This Letter reports new results from the MINOS experiment based on a two-year exposure to muon neutrinos from the Fermilab NuMI beam. Our data are consistent with quantum-mechanical oscillations of neutrino flavor with mass splitting |Deltam2| = (2.43+/-0.13) x 10(-3) eV2 (68% C.L.) and mixing angle sin2(2theta) > 0.90 (90% C.L.). Our data disfavor two alternative explanations for the disappearance of neutrinos in flight: namely, neutrino decays into lighter particles and quantum decoherence of neutrinos, at the 3.7 and 5.7 standard-deviation levels, respectively.
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We present a new measurement of the difference between the nucleon strange and antistrange quark distributions from dimuon events recorded by the NuTeV experiment at Fermilab. This analysis is the first to use a complete next to leading order QCD description of charm production from neutrino scattering. Dimuon events in neutrino deep inelastic scattering allow direct and independent study of the strange and antistrange content of the nucleon. We find a positive strange asymmetry with a significance of 1.6sigma. We also report a new measurement of the charm mass.
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This Letter reports results from the MINOS experiment based on its initial exposure to neutrinos from the Fermilab NuMI beam. The rates and energy spectra of charged current nu(mu) interactions are compared in two detectors located along the beam axis at distances of 1 and 735 km. With 1.27 x 10(20) 120 GeV protons incident on the NuMI target, 215 events with energies below 30 GeV are observed at the Far Detector, compared to an expectation of 336+/-14 events. The data are consistent with nu(mu) disappearance via oscillations with |Delta(m)2/32|=2.74 +0.44/-0.26 x10(-3)eV(2) and sin(2)(2theta(23))>0.87 (68% C.L.).
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Limits on nu(mu)-->nu(e) and nu(mu)-->nu(e) oscillations are extracted using the NuTeV detector with sign-selected nu(mu) and nu(mu) beams. In nu(mu) mode, for the case of sin(2)2alpha = 1, Delta(m)(2)>2.6 eV(2) is excluded, and for Delta(m)(2)>>1000 eV(2), sin(2)2alpha>1.1 x 10(-3). The NuTeV data exclude the high Delta(m)(2) end of nu(mu)-->nu(e) oscillation parameters favored by the LSND experiment without the need to assume that the oscillation parameters for nu and nu are the same. We present the most stringent experimental limits for nu(mu)(nu(mu))-->nu(e)(nu(e)) oscillations in the large Delta(m)(2) region.
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The NuTeV Collaboration has extracted the electroweak parameter sin(2)theta(W) from the measurement of the ratios of neutral current to charged current nu and (-)nu cross sections. Our value, sin(2)theta((on-shell))(W) = 0.2277 +/- 0.0013(stat) +/- 0.0009(syst), is 3 standard deviations above the standard model prediction. We also present a model independent analysis of the same data in terms of neutral-current quark couplings.
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We report on the extraction of R = sigma(L)/sigma(T) from CCFR nu(mu)-Fe and nu(mu)-Fe differential cross sections. The CCFR differential cross sections do not show the deviations from the QCD expectations that are seen in the CDHSW data at very low and very high x. R as measured in nu(mu) scattering is in agreement with R as measured in muon and electron scattering. All data on R for Q(2)>1 GeV(2) are in agreement with a NNLO QCD calculation which uses NNLO parton distribution functions and includes target mass effects. We report on the first measurements of R in the low x and Q(2)<1 GeV(2) region (where an anomalous large rise in R for nuclear targets has been observed by the HERMES Collaboration).
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The NuTeV experiment at Fermilab has used a sign-selected neutrino beam to perform a search for the lepton number violating process nu(mu)e(-)-->mu(-)nu(e), and to measure the cross section of the standard model inverse muon decay process nu(mu)e(-)-->mu(-)nu(e). NuTeV measures the inverse muon decay asymptotic cross-section slope sigma/E to be (13.8 +/- 1.2 +/- 1.4) x 10(-42) cm(2)/GeV. The experiment also observes no evidence for lepton number violation and places one of the most restrictive limits on the cross-section ratio sigma(nu(mu)e(-)-->mu(-)nu(e))/sigma(nu(mu)e(-)-->mu(-)nu(e)) < or = 1.7% at 90% C.L. for V-A couplings and < or = 0.6% for scalar couplings.
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A search for long-lived neutral particles ( N0's) with masses above 2.2 GeV/c(2) that decay into at least one muon has been performed using an instrumented decay channel at the NuTeV experiment at Fermilab. Data were examined for particles decaying into the final states mumu, mu(e), and mu(pi). Three mumu events were observed over an expected standard model background of 0.069+/-0.010 events; no events were observed in the other modes.
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A new structure function analysis of CCFR deep inelastic nu-N and nu-N scattering data is presented for previously unexplored kinematic regions down to Bjorken x = 0.0045 and Q(2) = 0.3 GeV(2). Comparisons to charged lepton scattering data from NMC and E665 experiments are made and the behavior of the structure function F(2)(nu)2 is studied in the limit Q(2)-->0.
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We report on the extraction of the structure functions F2 and DeltaxF(3) = xF(nu)(3)-xF(nu;)(3) from CCFR nu(mu)-Fe and nu;(mu)-Fe differential cross sections. The extraction is performed in a physics model-independent (PMI) way. This first measurement of DeltaxF(3), which is useful in testing models of heavy charm production, is higher than current theoretical predictions. The ratio of the F2 (PMI) values measured in nu(mu) and mu scattering is in agreement (within 5%) with the predictions of next-to-leading-order parton distribution functions using massive charm production schemes, thus resolving the long-standing discrepancy between the two sets of data.
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Atención a la Salud/normas , Calidad de la Atención de Salud , Comercio , Participación de la Comunidad , Control de Costos , Seguro de Costos Compartidos , Atención a la Salud/organización & administración , Costos de los Medicamentos , Industria Farmacéutica/economía , Humanos , Voluntad en Vida , Investigación , Estados UnidosRESUMEN
This paper reports the development of social work role and functions in a primary medical group practice which was established to replace the general medical clinics of a large urban voluntary teaching hospital in an academic medical center. It traces the shaping and implementation of a role which is functionally integral to the care, teaching and research goals of the practice; is operationalized into its service delivery system; and utilizes a full range of sophisticated social work skills. Along with physicians and nurse practitioners, the social worker is a principal provider of patient care, as well as physician educator and organizational consultant who contributes to coordinated, comprehensive and resource conservative care. Implications for other settings are noted.
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Consultores , Práctica de Grupo/organización & administración , Medicina Interna , Atención Primaria de Salud/organización & administración , Servicio Social/organización & administración , Centros Médicos Académicos , Adulto , Anciano , Anciano de 80 o más Años , Análisis Costo-Beneficio , Educación Médica , Femenino , Hospitales con más de 500 Camas , Humanos , Entrevista Psicológica , Persona de Mediana Edad , Ciudad de Nueva York , Innovación Organizacional , Grupo de Atención al Paciente , Psicoterapia , EnseñanzaRESUMEN
This article outlines inventory purchasing measures and provides examples of two cost centers in which these controls have been implemented at Saint Anthony Medical Center. It concentrates on specific aspects of inventory purchasing from product standardization to requisition and ordering.
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Inventarios de Hospitales/economía , Administración de Materiales de Hospital/economía , Departamento de Compras en Hospital/métodos , Hospitales con 300 a 499 Camas , OhioRESUMEN
We evaluated the treatment of asymptomatic patients with untreated syphilis of more than one year's duration (asymptomatic late syphilis) using a decision-analysis model. Two strategies were compared: treatment with 7.2 million units of penicillin G benzathine, or performing a lumbar puncture to test for asymptomatic neurosyphilis followed by penicillin and management based on cerebrospinal fluid analysis. Estimates of probabilities of disease prevalence, test sensitivity, and cure and complication rates were derived from published studies. Both strategies resulted in a cure rate of at least 99.7% using the best estimates. Although the strategy using lumbar puncture results in a 0.2% higher cure rate, its rate of complications (0.3%) exceeds its marginal benefit. We conclude that a lumbar puncture offers little additional benefit and may increase morbidity in patients with asymptomatic late syphilis.
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Neurosífilis/líquido cefalorraquídeo , Punción Espinal , Sífilis Latente/líquido cefalorraquídeo , Cefalea/etiología , Humanos , Modelos Biológicos , Neurosífilis/tratamiento farmacológico , Penicilina G Benzatina/uso terapéutico , Penicilina G Procaína/uso terapéutico , Penicilinas/uso terapéutico , Riesgo , Punción Espinal/efectos adversos , Sífilis Latente/tratamiento farmacológico , Factores de TiempoRESUMEN
Recent changes in the medical marketplace have led to increased competition among health care delivery organizations. Despite this, the academic medical center (AMC) and the health maintenance organization (HMO), even with apparently divergent goals, can interact so that both parties benefit. By developing a risk-sharing prospective reimbursement contract, the HMO can better predict tertiary care expenses. Concomitantly, the AMC can broaden its market and increase its access to patients requiring its technologically sophisticated services. This article presents a mechanism for creating a prospective reimbursement contract with mutually beneficial incentives. Implications of the methodology are also discussed.