1,205 research outputs found
A Bayesian study of quark models in view of recent astrophysical constraints
In this work, we perform a comparative analysis between the density-dependent
quark model and the vector MIT bag model using Bayesian analysis. We impose
four recent observational astrophysical constraints on both models to determine
their model-dependent parameters in an optimized manner. The restrictions are
aimed at producing stars with maximum masses M and a
mass-radii diagram compatible with the observed pulsars: PSR J0740+6620, PSR
J0952-0607, PSR J0030+0451 and the compact object XMMU J173203.3-344518. With
this analysis, the parameter dependence of the nuclear equation of state (EoS)
of both models is restricted
Highly water soluble room temperature superionic liquids of APIs
Fundacao para a Ciencia e a Tecnologia through project (PEst-C/LA0006/2013). The authors also thank Prof. Madalena Dionisio and Dr Natalia Correia for their support with the DSC analyses.Herein a straightforward approach for the enhancement of the water solubility of common antibiotic and NSAID active pharmaceutical ingredients (APIs) is presented. The APIs are converted into ionic liquids (API-ILs) and molten salts by combination with the organic superbases TMG, DBU and DBN. The prepared superionic liquids were characterized by 1H and 13C NMR as well as FTIR spectroscopy and elemental analysis. Most products are amorphous non-polymorphic room temperature ionic liquids with very high solubility in water, which may enhance the bioavailability of the API-ILs in comparison with the parent drugs.authorsversionpublishe
Quantum Configuration and Phase Spaces: Finsler and Hamilton Geometries
In this paper, we review two approaches that can describe, in a geometrical
way, the kinematics of particles that are affected by Planck-scale departures,
named Finsler and Hamilton geometries. By relying on maps that connect the
spaces of velocities and momenta, we discuss the properties of configuration
and phase spaces induced by these two distinct geometries. In particular, we
exemplify this approach by considering the so-called -de Sitter-inspired
modified dispersion relation as a laboratory for this study. We finalize with
some points that we consider as positive and negative ones of each approach for
the description of quantum configuration and phases spaces.Comment: 22 pages. Matches published version. Invited contribution for
Physics. Special Issue "New Advances in Quantum Geometry
Search for microwave emission from ultrahigh energy cosmic rays
We present a search for microwave emission from air showers induced by
ultrahigh energy cosmic rays with the microwave detection of air showers
experiment. No events were found, ruling out a wide range of power flux and
coherence of the putative emission, including those suggested by recent
laboratory measurements.Comment: 5 pages, 3 figure
Benefits in cardiac function by CD38 suppression: Improvement in NAD+ levels, exercise capacity, heart rate variability and protection against catecholamine-induced ventricular arrhythmias
CD38 enzymatic activity regulates NAD+ and cADPR levels in mammalian tissues, and therefore has a prominent role in cellular metabolism and calcium homeostasis. Consequently, it is reasonable to hypothesize about its involvement in cardiovascular physiology as well as in heart related pathological conditions. Aim: To investigate the role of CD38 in cardiovascular performance, and its involvement in cardiac electrophysiology and calcium-handling. Methods and results: When submitted to a treadmill exhaustion test, a way of evaluating cardiovascular performance, adult male CD38KO mice showed better exercise capacity. This benefit was also obtained in genetically modified mice with catalytically inactive (CI) CD38 and in WT mice treated with antibody 68 (Ab68) which blocks CD38 activity. Hearts from these 3 groups (CD38KO, CD38CI and Ab68) showed increased NAD+ levels. When CD38KO mice were treated with FK866 which inhibits NAD+ biosynthesis, exercise capacity as well as NAD+ in heart tissue decreased to WT levels. Electrocardiograms of conscious unrestrained CD38KO and CD38CI mice showed lower basal heart rates and higher heart rate variability than WT mice. Although inactivation of CD38 in mice resulted in increased SERCA2a expression in the heart, the frequency of spontaneous calcium release from the sarcoplasmic reticulum under stressful conditions (high extracellular calcium concentration) was lower in CD38KO ventricular myocytes. When mice were challenged with caffeine-epinephrine, CD38KO mice had a lower incidence of bidirectional ventricular tachycardia when compared to WT ones. Conclusion: CD38 inhibition improves exercise performance by regulating NAD+ homeostasis. CD38 is involved in cardiovascular function since its genetic ablation decreases basal heart rate, increases heart rate variability and alters calcium handling in a way that protects mice from developing catecholamine induced ventricular arrhythmias.Fil: Agorrody, Guillermo. Universidad de la Republica. Facultad de Medicina; UruguayFil: Peclat, Thais R.. Mayo Clinic College Of Medicine; Estados UnidosFil: Peluso, Gonzalo. Universidad de la Republica. Facultad de Medicina; UruguayFil: Gonano, Luis Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani". Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Investigaciones Cardiovasculares "Dr. Horacio Eugenio Cingolani"; ArgentinaFil: Santos, Leonardo. Instituto Pasteur de Montevideo; UruguayFil: van Schooten, Wim. Teneobio; Estados UnidosFil: Chini, Claudia C. S.. Mayo Clinic College Of Medicine; Estados UnidosFil: Escande, Carlos. Instituto Pasteur de Montevideo; UruguayFil: Chini, Eduardo N.. Mayo Clinic College Of Medicine; Estados UnidosFil: Contreras, Paola. Universidad de la Republica. Facultad de Medicina; Urugua
Rolling resistance contribution to a road pavement life cycle carbon footprint analysis
Purpose
Although the impact of road pavement surface condition on rolling resistance has been included in the life cycle assessment (LCA) framework of several studies in the last years, there is still a high level of uncertainty concerning the methodological assumptions and the parameters that can affect the results. In order to adopt pavement carbon footprint/LCA as a decision-making tool, it is necessary to explore the impact of the chosen methods and assumptions on the LCA results.
Methods
This paper provides a review of the main models describing the impact of the pavement surface properties on vehicle fuel consumption and analyses the influence of the methodological assumptions related to the rolling resistance on the LCA results. It compares the CO2 emissions, calculated with two different rolling resistance models existing in literature, and performs a sensitivity test on some specific input variables (pavement deterioration rate, traffic growth, and emission factors/fuel efficiency improvement).
Results and discussion
The model used to calculate the impact of the pavement surface condition on fuel consumption significantly affects the LCA results. The pavement deterioration rate influences the calculation in both models, while traffic growth and fuel efficiency improvement have a limited impact on the vehicle CO2 emissions resulting from the pavement condition contribution to rolling resistance.
Conclusions and recommendations
Existing models linking pavement condition to rolling resistance and hence vehicle emissions are not broadly applicable to the use phase of road pavement LCA and further research is necessary before a widely-used methodology can be defined. The methods of modelling and the methodological assumptions need to be transparent in the analysis of the impact of the pavement surface condition on fuel consumption, in order to be interpreted by decision makers and implemented in an LCA framework. This will be necessary before product category rules (PCR) for pavement LCA can be extended to include the use phase
The MIDAS telescope for microwave detection of ultra-high energy cosmic rays
We present the design, implementation and data taking performance of the
MIcrowave Detection of Air Showers (MIDAS) experiment, a large field of view
imaging telescope designed to detect microwave radiation from extensive air
showers induced by ultra-high energy cosmic rays. This novel technique may
bring a tenfold increase in detector duty cycle when compared to the standard
fluorescence technique based on detection of ultraviolet photons. The MIDAS
telescope consists of a 4.5 m diameter dish with a 53-pixel receiver camera,
instrumented with feed horns operating in the commercial extended C-Band (3.4
-- 4.2 GHz). A self-trigger capability is implemented in the digital
electronics. The main objectives of this first prototype of the MIDAS telescope
- to validate the telescope design, and to demonstrate a large detector duty
cycle - were successfully accomplished in a dedicated data taking run at the
University of Chicago campus prior to installation at the Pierre Auger
Observatory.Comment: 13 pages, 18 figure
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