ABSTRACT
HD 165052 is a short-period massive eccentric binary system that undergoes apsidal motion. As the rate of apsidal motion is directly related to the internal structure constants of the binary ...components, its study allows getting insight into the internal structure of the stars. We use medium- and high-resolution spectroscopic observations of HD 165052 to provide constraints on the fundamental properties of the binary system and the evolutionary state of its components. We apply a spectral disentangling code to reconstruct artefact-free spectra of the individual stars and derive the radial velocities (RVs) at the times of the observations. We perform the first analysis of the disentangled spectra with the non-local thermodynamic equilibrium model atmosphere code CMFGEN to determine the stellar properties. We derive the first self-consistent orbital solution of all existing RV data, including those reported in the literature, accounting for apsidal motion. We build, for the very first time, dedicated stellar evolution tracks with the Clés code requesting the theoretical effective temperatures and luminosities to match those obtained from our spectroscopic analysis. The binary system HD 165052, consisting of an O6.5 V((f)) primary ($T_\text{eff,P}=37\, 500 \pm 1000$ K) and an O7 V((f)) secondary ($T_\text{eff,S}=36\, 000 \pm 1000$ K), displays apsidal motion at a rate of $(11.30^{+0.64}_{-0.49})^\circ$ yr−1. Evolutionary masses are compared to minimum dynamical masses to constrain the orbital inclination. Evolutionary masses $M_\text{ev,P}=24.8\pm 1.0\, \mathrm{M}_\odot$ and $M_\text{ev,S}=20.9\pm 1.0\, \mathrm{M}_\odot$ and radii $R_\text{ev,P}=7.0^{+0.5}_{-0.4}\, \mathrm{R}_\odot$ and $R_\text{ev,S}=6.2^{+0.4}_{-0.3}\, \mathrm{R}_\odot$ are derived, and the inclination is constrained to 22.1° ≤ i ≤ 23.3°. Theoretical apsidal motion rates, derived assuming an age of 2.0 ± 0.5 Myr for the binary, are in agreement with the observational determination. The agreement with theoretical apsidal motion rates enforces the inferred values of the evolutionary stellar masses and radii.
AgBiS2 is a promising and environmentally friendly absorber material for use in hybrid solar cells (HSC). Here, we report a study on the evolution of interfacial phenomena observed during deposition ...of AgBiS2 onto mesoporous TiO2 by the two-stage successive ionic layer adsorption-reaction method. With this approach, inorganic-organic HSC were assembled using Co2+ doped P3HT as hole transport layer. Surface photovoltage spectroscopy and contact potential difference measurements corroborated a low density of trap states in the ternary chalcogenide and lack of majority carrier barriers, compared to the binary absorbers used as reference. The best HSC exhibits a power conversion efficiency of 2.87% under irradiation of 100 mW cm−2, which is attractive for an easily scalable, no capping, no passivating synthesis of AgBiS2.
Patients with type 2 diabetes mellitus (T2DM) are characterized by chronic hyperglycemia as a consequence of decreased insulin sensitivity, which contributes to bone demineralization and could also ...be related to changes in serum levels of osteocalcin and insulin, particularly when coupled with a deficiency in the daily consumption of vitamins D3 and K2. The objective of this study was to evaluate the effect of vitamin D3 and vitamin K2 supplements alone or in combination on osteocalcin levels and metabolic parameters in patients with T2DM.
A double-blind, randomized clinical trial was carried out in 40 patients aged between 30 and 70 years old for 3 months. Clinical and laboratory assessment was carried out at the beginning and at the end of the treatment. The patients were divided into three groups: (a) 1000 IU vitamin D3 + a calcinated magnesium placebo (n = 16), (b) 100 µg of Vitamin K2 + a calcinated magnesium placebo (n = 12), and (c) 1000 IU vitamin D3 + 100 µg vitamin K2 (n = 12).
After treatment in the total studied population, a significant decrease in glycemia (p = 0.001), HOMA-IR (Homeostatic model assessment-insulin resistance) (p = 0.040), percentage of pancreatic beta cells (p < 0.001), uOC/cOC index and diastolic blood pressure (p = 0.030) were observed; in vitamin D3 group, differences in serum undercarboxylated osteocalcin (p = 0.026), undercarboxylated to carboxylated osteocalcin index (uOC/cOC) (p = 0.039) glucose (p < 0.001) and % of functional pancreatic beta cells (p < 0.001) were demonstrated. In vitamin K2 group a significant decrease in glycemia (p = 0.002), HOMA-IR (p = 0.041), percentage of pancreatic beta cells (p = 0.002), and in cOC (p = 0.041) were observed, conversely cOC concentration was found high. Finally, in the vitamins D3 + K2 a significant decrease in glycemia (p = 0.002), percentage of pancreatic beta cells (p = 0.004), and in the uOC/cOC index (p = 0.023) were observed.
Individual or combined supplementation with vitamins D3 and K2 significantly decreases the glucose levels and % of functional pancreatic beta cells, while D3 and D3 + K2 treatments also induced a reduction in the uOC/cOC index. Only in the group with vitamin D3 supplementation, it was observed a reduction in undercarboxylated osteocalcin while vitamin K2 increased the carboxylated osteocalcin levels.
NCT04041492.
We develop a formalism which provides a new view for the transformation of spherically symmetric metrics, regarding cosmological and Kruskal type metrics. Our analysis begins with some general ...relevant dynamical metrics in cosmology, and prove that they all can be transformed to a unique static form. We extend the formalism to obtain generalized Kruskal type coordinates in cosmology and black hole theory. This extended formalism provides a novel mechanism to obtain suitable coordinate charts associated with spherically symmetric metrics. In particular, we obtain explicitly new Kruskal type coordinates for extremal Reissner-Nordström and Schwarzschild-de-Sitter metrics, as well for an extension of the de-Sitter metric.
Glutamate dysfunction has been implicated in a number of substance of abuse studies, including cocaine and methamphetamine. Moreover, in attention-deficit/hyperactivity disorder (ADHD), it has been ...discovered that when the initiation of stimulant treatment occurs during adolescence, there is an increased risk of developing a substance use disorder later in life. The spontaneously hypertensive rat (SHR) serves as a phenotype for ADHD and studies have found increased cocaine self-administration in adult SHRs when treated with the stimulant methylphenidate (MPH) during adolescence. For this reason, we wanted to examine glutamate signaling in the pre-limbic frontal cortex, a region implicated in ADHD and drug addiction, in the SHR and its progenitor control strain, the Wistar Kyoto (WKY). We chronically implanted glutamate-selective microelectrode arrays (MEAs) into 8-week-old animals and treated with MPH (2 mg/kg, s.c.) for 11 days while measuring tonic and phasic extracellular glutamate concentrations. We observed that intermediate treatment with a clinically relevant dose of MPH increased tonic glutamate levels in the SHR but not the WKY compared to vehicle controls. After chronic treatment, both the SHR and WKY exhibited increased tonic glutamate levels; however, only the SHR was found to have decreased amplitudes of phasic glutamate signaling following chronic MPH administration. The findings from this study suggest that the MPH effects on extracellular glutamate levels in the SHR may potentiate the response for drug abuse later in life. Additionally, these data illuminate a pathway for investigating novel therapies for the treatment of ADHD and suggest that possibly targeting the group II metabotropic glutamate receptors may be a useful therapeutic avenue for adolescents diagnosed with ADHD.
Primates are declining worldwide and rapid infrastructure expansion, particularly roads, threatens their habitat. New roads fragment habitats allowing anthropogenic activities to occur in once ...pristine ecosystems; this is particularly impactful in tropical areas with high endemic biodiversity, as is occurring with primates in Colombia. However, temporal assessments of how roads impact local biodiversity are rare. We conducted a comprehensive assessment of the exposure of Colombian primates to roads from 1970 to 2015. Using a spatially explicit and species‐specific approach, we estimated the critical road density and the critical patch size primate species can withstand before going locally extinct. Then, overlapping 15 primate species (~40% of the primate species present in Colombia) ranges with Colombia's road networks over time, we determined the road expansion scope within each habitat and consequent fragmentation. Comparing the species critical road density and patch size, we determined the degree of road exposure of each species over time and its vulnerability to local extinction. Our results show that between 1970 and 2015, there were nearly 40 000 km2 where at least one species was at risk of local extinction, due to road expansion, principally in the Andean and Caribbean regions. Primates in these regions faced the greatest exposure to road impacts, with an average 16% increase in the amount of affected habitat during this period. Species in most need of conservation based on road exposure rankings are: Cebus versicolor, Aotus griseimembra, Ateles hybridus, Saguinus leucopus and Saguinus oedipus. Our study contributes to understanding road impacts on local biodiversity in one of the biodiversity hotspots across the tropics and highlights the need of infrastructure accounting for the necessary mitigation and conservation actions.
We conducted a comprehensive assessment of the exposure of Colombian primates to roads from 1970 to 2015. Using a spatially explicit and species‐specific approach, we estimated the critical road density and the critical patch size primate species can withstand before going locally extinct. Our results show that between 1970 and 2015, there were nearly 40 000 km2 where at least one species was at risk of local extinction, due to road expansion, principally in the Andean and Caribbean regions. Primates in these regions faced the greatest exposure to road impacts, with an average 16% increase in the amount of affected habitat during this period.
Superconducting coplanar-waveguide resonators that can operate in strong magnetic fields are important tools for a variety of high-frequency superconducting devices. Magnetic fields degrade resonator ...performance by creating Abrikosov vortices that cause resistive losses and frequency fluctuations or suppress the superconductivity entirely. To mitigate these effects, we investigate lithographically defined artificial defects in resonators fabricated from Nb-TiN superconducting films. We show that by controlling the vor-tex dynamics, the quality factor of resonators in perpendicular magnetic fields can be greatly enhanced. Coupled with the restriction of the device geometry to enhance the superconductors critical field, we demonstrate stable resonances that retain quality factors 10 5 at the single-photon power level in perpendicular magnetic fields up to B ⊥ 20 mT and parallel magnetic fields up to B 6 T. We demonstrate the effectiveness of this technique for hybrid systems by integrating an In-Sb nanowire into a field-resilient superconducting resonator and use it to perform fast charge readout of a gate-defined double quantum dot at B = 1 T.
Growth performance of hatchery-reared Spotted Rose Snapper Lutjanus guttatus reared at two culture systems were studied, discussed and compared. We stocked 150 juveniles (mean, 124 g) into each of ...three floating cages and three onshore tanks (3 m ³) supplied with seawater of similar temperature (range 23–29°C). Fish were fed twice daily with an extruded diet containing 50% crude protein and 12% crude lipid. The survival rate was above 90%. After 120 d, the mean weight at harvest was 30% greater among fish reared in cages (337 g) versus tanks (255 g). The final feed conversion (1.44 for cages and 1.48 for tanks) differed between the culture systems. Growth in weight was described by the following exponential equations: W = 132.23 e ⁰.⁰⁰⁷⁹ᵗ, R ² = 0.98 for cages and W = 129.50 e ⁰.⁰⁰⁵⁸ᵗ, R ² = 0.99 for tanks. The residual sum of squares analysis indicated that these curves were different. The exponents (b) of the length–weight relationship calculated for cages (3.03) versus tanks (3.00) demonstrated that cultured Spotted Rose Snapper have a higher condition factor than do their wild counterparts, and those raised in cages show better growth than do those raised in tanks.
•We developed ceramic-based, dual-sided biomorphic 8-site biosensors.•Dual-sided design may help optimize spatial detection of neurotransmitters.•In vitro calibrations show glutamate responses only ...on glutamate-sensitive sites.•Simultaneous glutamate detection from four cortical locations in freely moving rats.
The aberrant regulation of glutamate has been implicated in numerous psychiatric disorders including drug addiction and attention-deficit/hyperactivity disorder. To understand glutamate signaling and its role in facilitating disease, tools to directly measure glutamate in a complex, neural network are needed.
The development of a ceramic-based, dual-sided, biomorphic microelectrode array with four recording sites on each side to facilitate a more detailed measurement of glutamate in awake, behaving rodents.
In vitro calibrations of these biosensors showed selective and specific responses to glutamate. In awake rats, these biomorphic electrode arrays enabled the concurrent evaluation of glutamate in a network, the frontal cortex: including the cingulate, prelimbic, infralimbic and dorsal peduncle regions. Regions within the frontal cortex exhibited varying phasic glutamate patterns in awake animals.Comparison with existing method: Existing methodologies to measure glutamate neurotransmission employ single-sided biosensors or biosensors capable of measuring neurochemicals at only one location in space.
Multi-site, biomorphic neurochemical biosensors provide a method for simultaneously measuring glutamate in multiple areas of a neural network in the brain.
Fetoscopic repair of spina bifida: safer and better? Pedreira, D. A. L.; Reece, E. A.; Chmait, R. H. ...
Ultrasound in obstetrics & gynecology,
August 2016, 2016-Aug, 2016-08-00, 20160801, Letnik:
48, Številka:
2
Journal Article
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