1,848 research outputs found

    Developing an Undergraduate Community Psychology Program in a Graduate Institution

    Get PDF
    This article provides an overview of the undergraduate degree program in community psychology at DePaul University. The recommendation of an undergraduate student ignited latent student and faculty interest. A program-bigger than a course but smaller than a major-was developed in 2005-2006 and was first offered in 2006-2007. Subsequently, this Community Concentration has been well received by students and has grown to an enrollment of about 20-25 students annually (Glantsman, McMahon, & Njoku, 2015). Graduates have gone onto positions in community and public agencies, graduate school in community psychology and related fields, and other relevant contexts. We highlight the three primary phases in the history of the Community Concentration: (1) building upon a receptive institutional context, (2) creating the program, and (3) developing learning opportunities. For each phase we identify focal elements important to its success. We consider their transferability to other educational settings that include both undergraduate and graduate community psychology educational opportunities. We note the accomplishments, challenges and strengths of the program. Finally, we offer this case study to encourage faculty in other educational institutions to develop more and better learning opportunities for undergraduate students in community psychology

    Developing an Undergraduate Community Psychology Program in a Graduate Institution

    Get PDF
    This article provides an overview of the undergraduate degree program in community psychology at DePaul University. The recommendation of an undergraduate student ignited latent student and faculty interest. A program-bigger than a course but smaller than a major-was developed in 2005-2006 and was first offered in 2006-2007. Subsequently, this Community Concentration has been well received by students and has grown to an enrollment of about 20-25 students annually (Glantsman, McMahon, & Njoku, 2015). Graduates have gone onto positions in community and public agencies, graduate school in community psychology and related fields, and other relevant contexts. We highlight the three primary phases in the history of the Community Concentration: (1) building upon a receptive institutional context, (2) creating the program, and (3) developing learning opportunities. For each phase we identify focal elements important to its success. We consider their transferability to other educational settings that include both undergraduate and graduate community psychology educational opportunities. We note the accomplishments, challenges and strengths of the program. Finally, we offer this case study to encourage faculty in other educational institutions to develop more and better learning opportunities for undergraduate students in community psychology

    A Search for High-Frequency Coronal Brightness Variations in the 21 August 2017 Total Solar Eclipse

    Get PDF
    We report on a search for short-period intensity variations in the green-line FeXIV 530.3 nm emission from the solar corona during the 21 August 2017 total eclipse viewed from Idaho in the United States. Our experiment was performed with a much more sensitive detection system, and with better spatial resolution, than on previous occasions (1999 and 2001 eclipses), allowing fine details of quiet coronal loops and an active-region loop system to be seen. A guided 200-mm-aperture Schmidt-Cassegrain telescope was used with a state-of-the-art CCD camera having 16-bit intensity discrimination and a field-of-view 0.43 degree x 0.43 degree that encompassed approximately one third of the visible corona. The camera pixel size was 1.55 arcseconds, while the seeing during the eclipse enabled features of approx. 2 arcseconds (1450 km on the Sun) to be resolved. A total of 429 images were recorded during a 122.9 second portion of the totality at a frame rate of 3.49 images per second. In the analysis, we searched particularly for short-period intensity oscillations and travelling waves, since theory predicts fast-mode magneto-hydrodynamic (MHD) waves with short periods may be important in quiet coronal and active-region heating. Allowing first for various instrumental and photometric effects, we used a wavelet technique to search for periodicities in some 404 000 pixels in the frequency range 0.5-1.6 Hz (periods: 2 second to 0.6 second). We also searched for travelling waves along some 65 coronal structures. However, we found no statistically significant evidence in either. This negative result considerably refines the limit that we obtained from our previous analyses, and it indicates that future searches for short-period coronal waves may be better directed towards Doppler shifts as well as intensity oscillations

    The requirement for external carbonic anhydrase in diatoms is influenced by the supply and demand for dissolved inorganic carbon

    Get PDF
    Photosynthesis by marine diatoms contributes significantly to the global carbon cycle. Due to the low concentration of CO2 in seawater, many diatoms use extracellular carbonic anhydrase (eCA) to enhance the supply of CO2 to the cell surface. While much research has investigated how the requirement for eCA is influenced by changes in CO2 availability, little is known about how eCA contributes to CO2 supply following changes in the demand for carbon. We therefore examined how changes in photosynthetic rate influence the requirement for eCA in three centric diatoms. Modeling of cell surface carbonate chemistry indicated that diffusive CO2 supply to the cell surface was greatly reduced in large diatoms at higher photosynthetic rates. Laboratory experiments demonstrated a trend of an increasing requirement for eCA with increasing photosynthetic rate that was most pronounced in the larger species, supporting the findings of the cellular modeling. Microelectrode measurements of cell surface pH and O2 demonstrated that individual cells exhibited an increased contribution of eCA to photosynthesis at higher irradiances. Our data demonstrate that changes in carbon demand strongly influence the requirement for eCA in diatoms. Cell size and photosynthetic rate will therefore be key determinants of the mode of dissolved inorganic carbon uptake

    A general scaling relation for the critical current density in Nb3Sn

    Get PDF
    We review the scaling relations for the critical current density (Jc) in Nb3Sn wires and include recent findings on the variation of the upper critical field (Hc2) with temperature (T) and A15 composition. We highlight deficiencies in the Summers/Ekin relations, which are not able to account for the correct Jc(T) dependence. Available Jc(H) results indicate that the magnetic field dependence for all wires can be described with Kramer's flux shear model, if non-linearities in Kramer plots are attributed to A15 inhomogeneities. The strain (eps) dependence is introduced through a temperature and strain dependent Hc2*(T,eps) and Ginzburg- Landau parameter kappa1(T,eps) and a strain dependent critical temperature Tc(eps). This is more consistent than the usual Ekin unification, which uses two separate and different dependencies on Hc2*(T) and Hc2*(eps). Using a correct temperature dependence and accounting for the A15 inhomogeneities leads to a remarkable simple relation for Jc(H,T,eps). Finally, a new relation for s(eps) is proposed, based on the first, second and third strain invariants.Comment: Accepted Topical Review for Superconductor, Science and Technolog

    Disability, race/ethnicity and gender: themes of cultural oppression, acts of individual resistance

    Get PDF
    Abstract Community psychologists have called for research on human diversity and interactions between individuals and society with a focus on oppression. This study examines learning disabilities as they cooccur with other sociopolitical minority statuses. We examined dominant cultural narratives of and individual responses to learning disability, race/ethnicity and gender identified by low-income men and women of color with learning disabilities. Our qualitative analysis identified cultural narratives that suggest that: (1a) individuals with learning disabilities are perceived as having an illegitimate impairment and being of lower intellectual ability and unworthy; (1b) having an invisible disability facilitates passing as nondisabled, thereby lessening disability discrimination from within racial/ethnic groups; (1c) having a learning disability detracts from positive gender expectations and exacerbates negative ones; and (1d) gender and racial/ethnic narratives are relevant for individuals with learning disabilities. Our analysis also identified two overarching individual acts of resistance used to thwart internalization of oppressive cultural narratives: (2a) removing self from oppressive environments and (2b) reframing dominant cultural narratives (including discounting the validity of negative messages, using negative narratives for motivation, and engaging in positive self-talk). We discuss findings in relation to extant research and theory and consider implications for research, theory, and practice

    A chromospheric resonance cavity in a sunspot mapped with seismology

    Get PDF
    This is the author accepted manuscript. The final version is available from Nature Research via the DOI in this recordData availability: The data used in this paper are from the observing campaign entitled ‘The Influence of Magnetism on Solar and Stellar Atmospheric Dynamics’ (NSO-SP proposal T1081; principal investigator: D.B.J.), which employed the ground-based Dunn Solar Telescope, USA, during July 2016. Additional supporting observations were obtained from the publicly available NASA’s Solar Dynamics Observatory (https://sdo.gsfc.nasa.gov) data archive, which can be accessed via http://jsoc.stanford.edu/ajax/lookdata.html. The data that support the plots within this paper and other findings of this study are available from the corresponding author upon reasonable request.Code availability: The numerical code (Lare2D) used in the work can be downloaded from: https://warwick.ac.uk/fac/sci/physics/research/cfsa/people/tda/larexd/Sunspots are intense collections of magnetic fields that pierce through the Sun’s photosphere, with their signatures extending upwards into the outermost extremities of the solar corona1. Cutting-edge observations and simulations are providing insights into the underlying wave generation2, configuration3,4 and damping5 mechanisms found in sunspot atmospheres. However, the in situ amplification of magnetohydrodynamic waves6, rising from a few hundreds of metres per second in the photosphere to several kilometres per second in the chromosphere7, has, until now, proved difficult to explain. Theory predicts that the enhanced umbral wave power found at chromospheric heights may come from the existence of an acoustic resonator8–10, which is created due to the substantial temperature gradients experienced at photospheric and transition region heights11. Here, we provide strong observational evidence of a resonance cavity existing above a highly magnetic sunspot. Through a combination of spectropolarimetric inversions and comparisons with high-resolution numerical simulations, we provide a new seismological approach to mapping the geometry of the inherent temperature stratifications across the diameter of the underlying sunspot, with the upper boundaries of the chromosphere ranging between 1,300 ± 200 km and 2,300 ± 250 km. Our findings will allow the three-dimensional structure of solar active regions to be conclusively determined from relatively commonplace two-dimensional Fourier power spectra. The techniques presented are also readily suitable for investigating temperature-dependent resonance effects in other areas of astrophysics, including the examination of Earth–ionosphere wave cavities12.Science and Technology Facilities Council (STFC)Invest NI and Randox Laboratories LtdSpanish Ministry of Economy and CompetitivenessEuropean Union Horizon 2020Research Council of NorwayINAF Istituto Nazionale di AstrofisicaCalifornia State University Northridg

    DKIST unveils the serpentine topology of quiet Sun magnetism in the photosphere

    Full text link
    We present the first quiet Sun spectropolarimetric observations obtained with the Visible SpectroPolarimeter (ViSP) at the 4−4-m Daniel K. Inouye Solar Telescope (DKIST). We recorded observations in a wavelength range that includes the magnetically sensitive Fe I 6301.5/6302.56301.5/6302.5 A˚\AA doublet. With an estimated spatial resolution of 0.08'', this represents the highest spatial resolution full-vector spectropolarimetric observations ever obtained of the quiet Sun. We identified 5353 small-scale magnetic elements, including 4747 magnetic loops and 44 unipolar magnetic patches, with linear and circular polarisation detected in all of them. Of particular interest is a magnetic element in which the polarity of the magnetic vector appears to change three times in only 400400 km and which has linear polarisation signals throughout. We find complex Stokes VV profiles at the polarity inversion lines of magnetic loops and discover degenerate solutions, as we are unable to conclusively determine whether these arise due to gradients in the atmospheric parameters or smearing of opposite polarity signals. We analyse a granule which notably has linear and circular polarisation signals throughout, providing an opportunity to explore its magnetic properties. On this small scale we see the magnetic field strength range from 2525 G at the granular boundary to 22 kG in the intergranular lane (IGL), and sanity check the values with the weak and strong field approximations. A value of 22 kG in the IGL is among the highest measurements ever recorded for the internetwork.Comment: Accepted for publication in ApJ

    Cube law, condition factor and weight-length relationships: history, meta-analysis and recommendations

    Get PDF
    This study presents a historical review, a meta-analysis, and recommendations for users about weight–length relationships, condition factors and relative weight equations. The historical review traces the developments of the respective concepts. The meta-analysis explores 3929 weight–length relationships of the type W = aLb for 1773 species of fishes. It shows that 82% of the variance in a plot of log a over b can be explained by allometric versus isometric growth patterns and by different body shapes of the respective species. Across species median b = 3.03 is significantly larger than 3.0, thus indicating a tendency towards slightly positive-allometric growth (increase in relative body thickness or plumpness) in most fishes. The expected range of 2.5 < b < 3.5 is confirmed. Mean estimates of b outside this range are often based on only one or two weight–length relationships per species. However, true cases of strong allometric growth do exist and three examples are given. Within species, a plot of log a vs b can be used to detect outliers in weight–length relationships. An equation to calculate mean condition factors from weight–length relationships is given as Kmean = 100aLb−3. Relative weight Wrm = 100W/(amLbm) can be used for comparing the condition of individuals across populations, where am is the geometric mean of a and bm is the mean of b across all available weight–length relationships for a given species. Twelve recommendations for proper use and presentation of weight–length relationships, condition factors and relative weight are given
    • …
    corecore