Heritage Language Learners and Spanish for Specific Purposes: Bridging the Gap through Community Service Learning

The growth in the number of Spanish heritage language learners in languages for specific purposes classes has been accompanied by an increase in the number and types of community service learning programs in which these students can participate to better prepare them for future employment opportunities. In spite of the increase in the number of Spanish heritage language learners in the languages for specific purposes classroom, few studies have looked at these students in this setting and even fewer have looked at the role that community service learning can play in developing these learners’ domain-specific abilities. Through an analysis of research in the areas of heritage language learners, Spanish for specific purposes, and community service learning, this article discusses strategies to effectively teach Spanish heritage language learners in language for specific purposes classes and to develop their language and cultural knowledge through community service learning. In addition, we address many of the challenges that arise when connecting Spanish heritage language learners with community partners as well as the obstacles to the integration of community service learning into the Spanish for specific purposes curriculum. The article concludes providing suggestions on how community service can be used to help Spanish heritage language learners not only see the benefits of language for specific purposes courses but also transfer their skills to other fields of study

Chandra X-ray spectroscopy of the focused wind in the Cygnus X-1 system III. Dipping in the low/hard state

We present an analysis of three Chandra High Energy Transmission Gratings observations of the black hole binary Cyg X-1/HDE 226868 at different orbital phases. The stellar wind that is powering the accretion in this system is characterized by temperature and density inhomogeneities including structures, or "clumps", of colder, more dense material embedded in the photoionized gas. As these clumps pass our line of sight, absorption dips appear in the light curve. We characterize the properties of the clumps through spectral changes during various dip stages. Comparing the silicon and sulfur absorption line regions (1.6-2.7 keV $\equiv$ 7.7-4.6 {\AA}) in four levels of varying column depth reveals the presence of lower ionization stages, i.e., colder or denser material, in the deeper dip phases. The Doppler velocities of the lines are roughly consistent within each observation, varying with the respective orbital phase. This is consistent with the picture of a structure that consists of differently ionized material, in which shells of material facing the black hole shield the inner and back shells from the ionizing radiation. The variation of the Doppler velocities compared to a toy model of the stellar wind, however, does not allow us to pin down an exact location of the clump region in the system. This result, as well as the asymmetric shape of the observed lines, point at a picture of a complex wind structure.Comment: 19 pages, 15 figures, accepted for publication in A&

Core excitations across the neutron shell gap in ²⁰⁷Tl

The single closed-neutron-shell, one proton-hole nucleus 207Tl was populated in deep-inelastic collisions of a 208Pb beam with a 208Pb target. The yrast and near-yrast level scheme has been established up to high excitation energy, comprising an octupol

Black Brane Viscosity and the Gregory-Laflamme Instability

We study long wavelength perturbations of neutral black p-branes in asymptotically flat space and show that, as anticipated in the blackfold approach, solutions of the relativistic hydrodynamic equations for an effective p+1-dimensional fluid yield solutions to the vacuum Einstein equations in a derivative expansion. Going beyond the perfect fluid approximation, we compute the effective shear and bulk viscosities of the black brane. The values we obtain saturate generic bounds. Sound waves in the effective fluid are unstable, and have been previously related to the Gregory-Laflamme instability of black p-branes. By including the damping effect of the viscosity in the unstable sound waves, we obtain a remarkably good and simple approximation to the dispersion relation of the Gregory-Laflamme modes, whose accuracy increases with the number of transverse dimensions. We propose an exact limiting form as the number of dimensions tends to infinity.Comment: 16 pages, 3 figures. v2: minor corrections and refs adde

Alternative methods of determining hamstrings-to-quadriceps ratios: A comprehensive review

The hamstrings-to-quadriceps muscle strength ratio calculated by peak torque has been used as an important tool to detect muscle imbalance, monitor knee joint stability, describe muscle strength properties and functionality, and for lower extremity injury prevention and rehabilitation. However, this ratio does not consider other neuromuscular variables that can also influence the antagonist to agonist muscle relationship, such as torque produced at multiple angles of range of motion, explosive strength, muscle size, muscle fatigue, or muscle activation. The aim of this study was to comprehensively review alternative methods of determining the hamstrings-to-quadriceps ratio. These include ratios calculated by angle-specific torque, rate of torque development, muscle size, fatigue index, and muscle activation (measured by electromyography). Collectively, the literature demonstrates that utilizing alternative methods of determining the hamstrings-to-quadriceps ratio can be functionally relevant for a better understanding of the neuromuscular mechanisms underpinning the interaction of strength between hamstrings and quadriceps. However, there is insufficient evidence to recommend any of the alternative methods as sensitive clinical tools for predicting injury risk and monitoring knee joint integrity. Future longitudinal studies, along with injury incidence, are needed to further investigate all alternative methods of determining the hamstrings-to-quadriceps ratio. These have potential to offer insight into how athletes and the general population should be trained for performance enhancement and injury reduction, and may be used along with traditional methods for a thorough assessment of an individual\u27s H:Q muscle balance

Iron and Nickel Line Diagnostics for the Galactic Center Diffuse Emission

We have observed the diffuse X-ray emission from the Galactic center (GC) using the X-ray Imaging Spectrometer (XIS) on Suzaku. The high-energy resolution and the low-background orbit provide excellent spectra of the GC diffuse X-rays (GCDX). The XIS found many emission lines in the GCDX near the energy of K-shell transitions of iron and nickel. The most pronounced features are FeI K alpha at 6.4 keV and K-shell absorption edge at 7.1 keV, which are from neutral and/or low ionization states of iron, and the K-shell lines at 6.7 keV and 6.9 keV from He-like (FeXXV K alpha) and hydrogenic (FeXXVI Ly alpha) ions of iron. In addition, K alpha lines from neutral or low ionization nickel (NiI K alpha) and He-like nickel (NiXXVII K alpha), and FeI K beta, FeXXV K beta, FeXXVI Ly beta, FeXXV K gamma and FeXXVI Ly gamma are detected for the first time. The line center energies and widths of FeXXV K alpha and FeXXVI Ly alpha favor a collisional excitation (CE) plasma for the origin of the GCDX. The electron temperature determined from the line flux ratio of FeXXV K alpha / FeXXV K beta is similar to the ionization temperature determined from that of FeXXV K alpha /FeXXVI Ly alpha. Thus it would appear that the GCDX plasma is close to ionization equilibrium. The 6.7 keV flux and temperature distribution to the galactic longitude is smooth and monotonic,in contrast to the integrated point source flux distribution. These facts support the hypothesis that the GCDX is truly diffuse emission rather than the integration of the outputs of a large number of unresolved point sources. In addition, our results demonstrate that the chemical composition of Fe in the interstellar gas near the GC is constrained to be about 3.5 times solar.Comment: 11 pages, 19 figures. Accepted for publication in PASJ Suzaku Special Issue (vol. 59 sp. 1

Seminal plasma and prostaglandin E2 up-regulate fibroblast growth factor 2 expression in endometrial adenocarcinoma cells via E-series prostanoid-2 receptor-mediated transactivation of the epidermal growth factor receptor and extracellular signal-regulated kinase pathway

We report a multiwavelength (X-ray, ultraviolet/optical/infrared, radio) analysis of the relativistic tidal disruption event candidate Sw J2058+05 from 3 months to 3 yr post-discovery in order to study its properties and compare its behavior with that of Sw J1644+57. Our main results are as follows. (1) The long-term X-ray light curve of Sw J2058+05 shows a remarkably similar trend to that of Sw J1644+57. After a prolonged power-law decay, the X-ray flux drops off rapidly by a factor of $\gtrsim 160$ within a span of $\Delta$$t$/$t$ $\le$ 0.95. Associating this sudden decline with the transition from super-Eddington to sub-Eddington accretion, we estimate the black hole mass to be in the range of $10^{4-6}$ M$_{\odot}$. (2) We detect rapid ($\lesssim 500$ s) X-ray variability before the dropoff, suggesting that, even at late times, the X-rays originate from close to the black hole (ruling out a forward-shock origin). (3) We confirm using HST and VLBA astrometry that the location of the source coincides with the galaxy's center to within $\lesssim 400$ pc (in projection). (4) We modeled Sw J2058+05's ultraviolet/optical/infrared spectral energy distribution with a single-temperature blackbody and find that while the radius remains more or less constant at a value of $63.4 \pm 4.5$ AU ($\sim 10^{15}$ cm) at all times during the outburst, the blackbody temperature drops significantly from $\sim$ 30,000 K at early times to a value of $\sim$ 15,000 K at late times (before the X-ray dropoff). Our results strengthen Sw J2058+05's interpretation as a tidal disruption event similar to Sw J1644+57.Comment: Replaced with the published version of the manuscrip