2,914 research outputs found
Estimación de la demanda de viajes al lugar de estudio aplicando un modelo logit mixto de preferencias reveladas y declaradas
Este estudio presenta estimaciones de modelos de elección discreta basados en una muestra de estudiantes a partir de una prueba piloto. Se presentan los resultados correspondientes a los viajes al lugar de estudio por parte de estudiantes universitarios, algunos de los cuales además de estudiar, trabajan. Se ha estimado un modelo logit multinomial de elección de modo de transporte para viajar al lugar de estudio, en el que se han combinado datos de preferencias reveladas y declaradas. El estudio presenta, además, pronósticos de la cuota de mercado del uso de los diferentes modos de transporte, la valoración subjetiva de los ahorros de tiempo de viaje, tiempo de espera y cuadras caminadas en origen y destino al utilizar autobús, como así también las elasticidades de demanda de la elección de modo de transporte y los cambios en el excedente del consumidor ante la aplicación de políticas asociadas a cambios en algunas variables de nivel de servicio de los diferentes modos de transporte.The study presents discrete choice models estimated with a simple ofstudents from a pilot survey. It presents estimation results derived fromstudy journeys of university students, some of which are also workers. It has been estimated a multinomial logit model for the decisión of making trips to study places, combining revealed and stated preference data. The paper presents market share forecasts for transport modes considered, the subjective valuation of travel time savings, waiting time savings and savings of walked blocks in origin and destination using bus services. Also, it has been estimated the elasticities of demand from the mode choice model and consumer surplus changes derived from the application of policies associated to changes in level of service variables
transport services.http://www.aaep.org.ar/anales/works/works2016/sartori.pdfFil: Sartori, Juan José Pompilio. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas. Departamento de Economía y Finanzas e Instituto de Estadística y Demografía; Argentina.Fil: Sartori, Juan José Pompilio. Universidad Blas Pascal; Argentina.Fil: Oviedo, Jorge Mauricio. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas. Instituto y Departamento de Economía y Finanzas; Argentina.Fil: Oviedo, Jorge Mauricio. Universidad Blas Pascal; Argentina.Fil: Müller, Eric Roger. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas. Departamento de Economía y Finanzas; Argentina.Economía, Econometrí
Pancreatic stone protein as a novel marker for neonatal sepsis
Purpose: Early-onset sepsis (EOS) is one of the main causes for the admission of newborns to the neonatal intensive care unit. However, traditional infection markers are poor diagnostic markers of EOS. Pancreatic stone protein (PSP) is a promising sepsis marker in adults. The aim of this study was to investigate whether determining PSP improves the diagnosis of EOS in comparison with other infection markers. Methods: This was a prospective multicentre study involving 137 infants with a gestational age of >34weeks who were admitted with suspected EOS. PSP, procalcitonin (PCT), soluble human triggering receptor expressed on myeloid cells-1 (sTREM-1), macrophage migration inhibitory factor (MIF) and C-reactive protein (CRP) were measured at admission. Receiver-operating characteristic (ROC) curve analysis was performed. Results: The level of PSP in infected infants was significantly higher than that in uninfected ones (median 11.3 vs. 7.5ng/ml, respectively; p=0.001). The ROC area under the curve was 0.69 [95% confidence interval (CI) 0.59-0.80; p9ng/ml) and PCT (>2ng/ml) was the best predictor of EOS (0.83; 95% CI 0.74-0.93; p<0.001) and resulted in a negative predictive value of 100% and a positive predictive value of 71%. Conclusions: In this prospective study, the diagnostic performance of PSP and PCT was superior to that of traditional markers and a combination bioscore improved the diagnosis of sepsis. Our findings suggest that PSP is a valuable biomarker in combination with PCT in EO
The behaviour of political parties and MPs in the parliaments of the Weimar Republic
Copyright @ 2012 The Authors. This is the author's accepted manuscript. The final published article is available from the link below.Analysing the roll-call votes of the MPs of the Weimar Republic we find: (1) that party competition in the Weimar parliaments can be structured along two dimensions: an economic left–right and a pro-/anti-democratic. Remarkably, this is stable throughout the entire lifespan of the Republic and not just in the later years and despite the varying content of votes across the lifespan of the Republic, and (2) that nearly all parties were troubled by intra-party divisions, though, in particular, the national socialists and communists became homogeneous in the final years of the Republic.Zukunftskolleg, University of Konstan
Measurement of the cosmic ray spectrum above eV using inclined events detected with the Pierre Auger Observatory
A measurement of the cosmic-ray spectrum for energies exceeding
eV is presented, which is based on the analysis of showers
with zenith angles greater than detected with the Pierre Auger
Observatory between 1 January 2004 and 31 December 2013. The measured spectrum
confirms a flux suppression at the highest energies. Above
eV, the "ankle", the flux can be described by a power law with
index followed by
a smooth suppression region. For the energy () at which the
spectral flux has fallen to one-half of its extrapolated value in the absence
of suppression, we find
eV.Comment: Replaced with published version. Added journal reference and DO
Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory
The Auger Engineering Radio Array (AERA) is part of the Pierre Auger
Observatory and is used to detect the radio emission of cosmic-ray air showers.
These observations are compared to the data of the surface detector stations of
the Observatory, which provide well-calibrated information on the cosmic-ray
energies and arrival directions. The response of the radio stations in the 30
to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of
the incoming electric field. For the latter, the energy deposit per area is
determined from the radio pulses at each observer position and is interpolated
using a two-dimensional function that takes into account signal asymmetries due
to interference between the geomagnetic and charge-excess emission components.
The spatial integral over the signal distribution gives a direct measurement of
the energy transferred from the primary cosmic ray into radio emission in the
AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air
shower arriving perpendicularly to the geomagnetic field. This radiation energy
-- corrected for geometrical effects -- is used as a cosmic-ray energy
estimator. Performing an absolute energy calibration against the
surface-detector information, we observe that this radio-energy estimator
scales quadratically with the cosmic-ray energy as expected for coherent
emission. We find an energy resolution of the radio reconstruction of 22% for
the data set and 17% for a high-quality subset containing only events with at
least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO
Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy
We measure the energy emitted by extensive air showers in the form of radio
emission in the frequency range from 30 to 80 MHz. Exploiting the accurate
energy scale of the Pierre Auger Observatory, we obtain a radiation energy of
15.8 \pm 0.7 (stat) \pm 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV
arriving perpendicularly to a geomagnetic field of 0.24 G, scaling
quadratically with the cosmic-ray energy. A comparison with predictions from
state-of-the-art first-principle calculations shows agreement with our
measurement. The radiation energy provides direct access to the calorimetric
energy in the electromagnetic cascade of extensive air showers. Comparison with
our result thus allows the direct calibration of any cosmic-ray radio detector
against the well-established energy scale of the Pierre Auger Observatory.Comment: Replaced with published version. Added journal reference and DOI.
Supplemental material in the ancillary file
A review of nitrogen isotopic alteration in marine sediments
Key Points: Use of sedimentary nitrogen isotopes is examined; On average, sediment 15N/14N increases approx. 2 per mil during early burial; Isotopic alteration scales with water depth
Abstract:
Nitrogen isotopes are an important tool for evaluating past biogeochemical cycling from the paleoceanographic record. However, bulk sedimentary nitrogen isotope ratios, which can be determined routinely and at minimal cost, may be altered during burial and early sedimentary diagenesis, particularly outside of continental margin settings. The causes and detailed mechanisms of isotopic alteration are still under investigation. Case studies of the Mediterranean and South China Seas underscore the complexities of investigating isotopic alteration. In an effort to evaluate the evidence for alteration of the sedimentary N isotopic signal and try to quantify the net effect, we have compiled and compared data demonstrating alteration from the published literature. A >100 point comparison of sediment trap and surface sedimentary nitrogen isotope values demonstrates that, at sites located off of the continental margins, an increase in sediment 15N/14N occurs during early burial, likely at the seafloor. The extent of isotopic alteration appears to be a function of water depth. Depth-related differences in oxygen exposure time at the seafloor are likely the dominant control on the extent of N isotopic alteration. Moreover, the compiled data suggest that the degree of alteration is likely to be uniform through time at most sites so that bulk sedimentary isotope records likely provide a good means for evaluating relative changes in the global N cycle
Reception Test of Petals for the End Cap TEC+ of the CMS Silicon Strip Tracker
The silicon strip tracker of the CMS experiment has been completed and was inserted into the CMS detector in late 2007. The largest sub system of the tracker are its end caps, comprising two large end caps (TEC) each containing 3200 silicon strip modules. To ease construction, the end caps feature a modular design: groups of about 20 silicon modules are placed on sub-assemblies called petals and these self-contained elements are then mounted onto the TEC support structures. Each end cap consists of 144 such petals, which were built and fully qualified by several institutes across Europe. Fro
Integration of the End Cap TEC+ of the CMS Silicon Strip Tracker
The silicon strip tracker of the CMS experiment has been completed and inserted into the CMS detector in late 2007. The largest sub-system of the tracker is its end cap system, comprising two large end caps (TEC) each containing 3200 silicon strip modules. To ease construction, the end caps feature a modular design: groups of about 20 silicon modules are placed on sub-assemblies called petals and these self-contained elements are then mounted into the TEC support structures. Each end cap consists of 144 petals, and the insertion of these petals into the end cap structure is referred to as TEC integration. The two end caps were integrated independently in Aachen (TEC+) and at CERN (TEC--). This note deals with the integration of TEC+, describing procedures for end cap integration and for quality control during testing of integrated sections of the end cap and presenting results from the testing
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