Findings from family and twin studies support a genetic contribution to the development of sexual orientation in men. However, previous studies have yielded conflicting evidence for linkage to ...chromosome Xq28.
We conducted a genome-wide linkage scan on 409 independent pairs of homosexual brothers (908 analyzed individuals in 384 families), by far the largest study of its kind to date.
We identified two regions of linkage: the pericentromeric region on chromosome 8 (maximum two-point LOD = 4.08, maximum multipoint LOD = 2.59), which overlaps with the second strongest region from a previous separate linkage scan of 155 brother pairs; and Xq28 (maximum two-point LOD = 2.99, maximum multipoint LOD = 2.76), which was also implicated in prior research.
Results, especially in the context of past studies, support the existence of genes on pericentromeric chromosome 8 and chromosome Xq28 influencing development of male sexual orientation.
Analysis methods are developed that fully determine a switched-capacitor (SC) dc-dc converter's steady-state performance through evaluation of its output impedance. This analysis method has been ...verified through simulation and experimentation. The simple formulation developed permits optimization of the capacitor sizes to meet a constraint such as a total capacitance or total energy storage limit, and also permits optimization of the switch sizes subject to constraints on total switch conductances or total switch volt-ampere (V-A) products. These optimizations then permit comparison among several switched-capacitor topologies, and comparisons of SC converters with conventional magnetic-based dc-dc converter circuits, in the context of various application settings. Significantly, the performance (based on conduction loss) of a ladder-type converter is found to be superior to that of a conventional magnetic-based converter for medium to high conversion ratios.
We present the discovery of PS18kh, a tidal disruption event discovered at the center of SDSS J075654.53+341543.6 (d 322 Mpc) by the Pan-STARRS Survey for Transients. Our data set includes ...pre-discovery survey data from Pan-STARRS, the All-sky Automated Survey for Supernovae, and the Asteroid Terrestrial-impact Last Alert System as well as high-cadence, multiwavelength follow-up data from ground-based telescopes and Swift, spanning from 56 days before peak light until 75 days after. The optical/UV emission from PS18kh is well-fit as a blackbody with temperatures ranging from T 12,000 K to T 25,000 K and it peaked at a luminosity of L 8.8 × 1043 erg s−1. PS18kh radiated E = (3.45 0.22) × 1050 erg over the period of observation, with (1.42 0.20) × 1050 erg being released during the rise to peak. Spectra of PS18kh show a changing, boxy/double-peaked H emission feature, which becomes more prominent over time. We use models of non-axisymmetric accretion disks to describe the profile of the H line and its evolution. We find that at early times the high accretion rate leads the disk to emit a wind which modifies the shape of the line profile and makes it bell-shaped. At late times, the wind becomes optically thin, allowing the non-axisymmetric perturbations to show up in the line profile. The line-emitting portion of the disk extends from rin ∼ 60rg to an outer radius of rout ∼ 1400rg and the perturbations can be represented either as an eccentricity in the outer rings of the disk or as a spiral arm in the inner disk.
Abstract
We present a family of self-consistent axisymmetric rotating globular cluster models which are fitted to spectroscopic data for NGC 362, NGC 1851, NGC 2808, NGC 4372, NGC 5927 and NGC 6752 ...to provide constraints on their physical and kinematic properties, including their rotation signals. They are constructed by flattening Modified Plummer profiles, which have the same asymptotic behaviour as classical Plummer models, but can provide better fits to young clusters due to a slower turnover in the density profile. The models are in dynamical equilibrium as they depend solely on the action variables. We employ a fully Bayesian scheme to investigate the uncertainty in our model parameters (including mass-to-light ratios and inclination angles) and evaluate the Bayesian evidence ratio for rotating to non-rotating models. We find convincing levels of rotation only in NGC 2808. In the other clusters, there is just a hint of rotation (in particular, NGC 4372 and NGC 5927), as the data quality does not allow us to draw strong conclusions. Where rotation is present, we find that it is confined to the central regions, within radii of R ≤ 2r
h
. As part of this work, we have developed a novel q-Gaussian basis expansion of the line-of-sight velocity distributions, from which general models can be constructed via interpolation on the basis coefficients.
A method for estimating the phase current unbalance in a multiphase buck converter is presented. The method uses the information contained in the voltage drop at the input capacitor's effective ...series resistance (ESR) to estimate the average current in each phase. Although the absolute estimation of the currents depends on the value of the ESR and is therefore not absolutely accurate, the relative estimates of the currents with respect to one other are shown to be very accurate. The method can be implemented with a low-rate down-sampling A/D converter and is not computationally intensive. Experimental results are presented, showing good agreement between the estimates and the measured values.
Historically, variable and transient sources have both surprised astronomers and provided new views of the heavens. Here we report the discovery of an optical transient in the outskirts of the ...lenticular galaxy Messier 85 in the Virgo cluster. With a peak absolute R magnitude of -12, this event is distinctly brighter than novae, but fainter than type Ia supernovae (which are expected in a population of old stars in lenticular galaxies). Archival images of the field do not show a luminous star at that position with an upper limit in the g filter of about -4.1 mag, so it is unlikely to be a giant eruption from a luminous blue variable star. Over a two-month period, the transient source emitted radiation energy of almost 1047 erg and subsequently faded in the optical sky. It is similar to, but six times more luminous at peak than, an enigmatic transient in the galaxy M31 (ref. 1). A possible origin of M85 OT2006-1 is a stellar merger. If so, searches for similar events in nearby galaxies will not only allow study of the physics of hyper-Eddington sources, but also probe an important phase in the evolution of stellar binary systems.
Erosion analysis is crucial for the design, operation, and economic assessment of slurry pipelines. Since field-scale pipe tests are difficult to control, lab-scale experiments are frequently ...employed. However, these techniques produce hydrodynamic conditions dissimilar to pipe flow. The Toroid Wear Tester (TWT) is a lab-scale tester with several promising attributes, including hydrodynamics more similar to pipe flow than other wear testers. However, no detailed studies on TWT performance and hydrodynamics have been performed. This work evaluates the repeatability and parametric wear trends of a TWT, as well as the major differences between TWT and pipe-flow hydrodynamics. Different particle sizes (0.1–2 mm) were tested at varying speeds (1–3 m/s) and solids concentrations (5–30% by volume). Visualization experiments showed that only larger particle sizes or lower TWT speeds are suitable for generating sliding-bed-dominated erosion comparable to pipe flow. Visualizations are also used to obtain correction factors for the TWT data, showing that visualization is a critical component of TWT testing. In addition to previously observed particle–coupon contact time and particle degradation effects, normal load and coupon edge effects are identified as important. Despite these limitations, the TWT is a promising apparatus for ranking material wear resistance and, with careful interpretation, for making pipeline erosion predictions.
•A Toroid Wear Tester (TWT) is examined for use in slurry pipeline wear tests.•The TWT flow is similar to pipeline flow within certain ranges of operating conditions.•Correction factors are necessary to account for differences between the TWT and pipe flow.•With careful interpretation, TWT data show promise for use in pipeline erosion predictions.
The aims of this study were to 1) compare active drag (Da) calculation between a single land-based measurement of frontal surface area (FSA) and in-water FSA measures obtained at key events of the ...arm pull (1, right upper-limb catch; 2, right upper-limb insweep; 3, right upper-limb exit and left upper-limb catch; 4, left upper-limb insweep; and 5, left upper-limb exit and right upper-limb catch) at front crawl swimming, and 2) compare mechanical power variables computed based on these two approaches.
Seventeen swimmers (11, male; 6, female; 16.15 ± 0.94 yr old) were recruited. The FSA was measured based on two approaches: (i) nonvariation, that is, assuming a constant value, and (ii) variation, that is, calculated in each key event of the front crawl swim. Active drag based on a nonvariation of the FSA was measured using the Velocity Perturbation method. Active drag based on a variation approach was measured in each key event of the front crawl according to the law of linear motion. Paired t-test (P ≤ 0.05), simple linear regression models, and Bland-Altman plots between assessment methods (variation vs nonvariation) were computed.
The FSA (variation) was higher than when assuming a nonvariation (0.1110 ± 0.010 vs 0.0968 ± 0.010 m, Δ = 15.69%, t = 4.40, P < 0.001, d = 0.95). Active drag (variation) was also significantly higher than when assuming a nonvariation (88.44 ± 25.92 vs 75.41 ± 15.11 N, Δ = 16.09%, t = 3.66, P = 0.002, d = 0.61).
Besides the FSA, swim velocity also changes during the front crawl arm pull. The variation of both variables had a significant effect on the active drag measurement and consequently on mechanical power and total power input variables.
We prospectively tested the quantitative myasthenia gravis score (QMG) for responsiveness and longitudinal construct validity in 53 patients with myasthenia gravis. Index of responsiveness was high. ...Longitudinal construct validity was confirmed by the correlation between changes in QMG and manual muscle testing and by a difference in QMG changes across patients that were clinically unchanged, improved, or worse between two visits. Our results support QMG use for assessing clinical change in trials.
A consistent framework for load-line regulation design is presented, applicable to microprocessor voltage regulators (VRs) using either electrolytic or ceramic output capacitors. With conventional ...feedback control, the loop bandwidth is limited by stability constraints linked to the switching frequency. The output capacitor has to be chosen sufficiently large to meet the stability requirement. Load-current feedforward can extend the useful bandwidth beyond that imposed by feedback stability constraints. With load-current feedforward, the size of the output capacitor can be reduced, since it is determined solely by large-signal and switching-ripple considerations which are shown to be less constraining than the feedback stability requirement. This work points to the feasibility of microprocessor VR implementations using only a small number of ceramic output capacitors, while running at sub-megahertz switching frequencies
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