1,618 research outputs found

    Understanding Informed Design through Trade-Off Decisions With an Empirically-Based Protocol for Students and Design Educators

    Get PDF
    Trade-off decisions, which necessitate striking a balance between two or more desirable but competing features, are a crucial part of design practice. However, they are known to be difficult for student designers to make. While designers, educators, and researchers have numerous methods to assess the quality of design artifacts, these methods are not necessarily easy to use, nor do they indicate design competency. Moreover, they are not grounded in a definition of engineering design. The objectives of this study were twofold. First, we developed a protocol to depict design artifact quality through the lens of design trade-off decisions. We aimed to produce a protocol that:(1) encompasses multiple complementary and competing dimensions, (2) can be applied consistently and systematically, and (3) indicates design competency. We conceptualized a quantitative representation of the degree to which a design artifact addresses human, technical, and economic requirements called the Trade-off Value Protocol. Second, we tested the Trade-off Value Protocol by applying it to 398 middle school students’ design artifacts of energy-efficient homes. We used an etic approach of thematic analysis to identify the patterns of variation therein. We found five distinct patterns of variation in the set of student design artifacts, which suggested certain trends in the way that students address design dimensions and demonstrate varying levels of design competency. The Trade-off Value Protocol isolates an important feature of design competency with which beginning designers often struggle and could be a tool for educators to help students become more informed designers

    What Does it Mean to Design? A Qualitative Investigation of Design Professionals' Experiences

    Full text link
    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95041/1/j.2168-9830.2012.tb00048.x.pd

    Guest Editorial Special Issue on Using Enquiry-and-Design-Based Learning to Spur Epistemological and Identity Development of Engineering Students

    Get PDF
    This Special Issue of the IEEE Transactions on Education focuses on using enquiry-based design projects to spur engineering students’ development, so as to increase understanding and application of the relevant theories, foster higher rates of student development and achieve this in healthy and productive ways

    Predicting sexual problems in women: The relevance of sexual excitation and sexual inhibition

    Get PDF
    This is the post-print version of the article. The official published version can be obtained from the link below.Data from a non-clinical sample of 540 heterosexual women were used to examine the relationships between scores on the Sexual Excitation/Sexual Inhibition Inventory for Women (SESII-W) and ratings of current sexual problems, lifetime arousal difficulty, lifetime orgasm difficulty, and lifetime problems with low sexual interest. Multiple regression analyses also included several demographic/background variables as predictors: age, full-time employment, completed college, children in household, married, health ratings, importance of sex, and whether the woman was in a sexual relationship. The strongest statistical predictors of both current and lifetime sexual problems were the SESII-W inhibition factors Arousal Contingency and Concerns about Sexual Function. Demographic factors did not feature largely in any of the models predicting sexual problems even when statistically significant relationships were found. If future research supports the predictive utility of the SESII-W in identifying women who are more likely to experience sexual difficulties, these scales may be used as prognostic factors in treatment studies.This study was funded, in part, by a grant from the Lilly Centre for Women's Health

    The Spectrally Resolved Lyman-alpha Emission of Three Lyman-alpha Selected Field Galaxies at z~2.4 from the HETDEX Pilot Survey

    Full text link
    We present new results on the spectrally resolved Lyman-alpha (LyA) emission of three LyA emitting field galaxies at z~2.4 with high LyA equivalent width (>100 Angstroms) and LyA luminosity (~10^43 erg/s). At 120 km/s (FWHM) spectral resolution, the prominent double-peaked LyA profile straddles the systemic velocity, where the velocity zero-point is determined from spectroscopy of the galaxies' rest-frame optical nebular emission lines. The average velocity offset from systemic of the stronger redshifted emission component for our sample is 176 km/s while the average total separation between the redshifted and main blueshifted emission components is 380 km/s. These measurements are a factor of ~2 smaller than for UV continuum-selected galaxies that show LyA in emission with lower LyA equivalent width. We compare our LyA spectra to the predicted line profiles of a spherical "expanding shell" LyA radiative transfer grid that models large-scale galaxy outflows. Specifically blueward of the systemic velocity where two galaxies show a weak, highly blueshifted (by ~1000 km/s) tertiary emission peak, the model line profiles are a relatively poor representation of the observed spectra. Since the neutral gas column density has a dominant influence over the shape of the LyA line profile, we caution against equating the observed LyA velocity offset with a physical outflow velocity, especially at lower spectral resolution where the unresolved LyA velocity offset is a convoluted function of several degenerate parameters. Referring to rest-frame ultraviolet and optical Hubble Space Telescope imaging, we find that galaxy-galaxy interactions may play an important role in inducing a starburst that results in copious LyA emission, as well as perturbing the gas distribution and velocity field which have strong influence over the LyA emission line profile.Comment: 20 pages, 8 figures, 3 tables; Accepted for publication in The Astrophysical Journal; Updated v2 fixes incorrectly processed LaTeX symbol

    Starting the conversation: land issues and critical conservation studies in post-colonial Africa

    Get PDF
    This thematic issue brings together the scholarly fields of critical conservation studies and African land issues, a relationship largely unexplored to date. The alienation of land for conservation purposes, introduced to Africa under colonial rule and still taking place today, has fundamental impacts on the politics of land and land use, and is contested in contemporary nation-states - including those that are attempting to implement land restitution and reform. The contributors explore these issues in a range of African contexts. Three key themes are identified: the problematic constructions of ‘community’ by outside agencies; spatial exclusion and the silencing of local voices; and the neoliberalisation of conservation spaces. In contributing to new perspectives on these themes, this thematic issue shows how discourses and practices of conservation, increasingly shaped by neoliberalism, currently impact on land ownership, access and use. It further highlights some important historical continuities. These trends can be observed in transfrontier conservation areas, on state-owned land used for conservation and ‘green’ initiatives, but also on private land where conservation is increasingly turned to commercial purposes.International Bibliography of Social Science

    The new nebula in LDN 1415 - A cry from the cradle of a low-luminosity source

    Get PDF
    A survey for candidate Herbig-Haro objects was performed to search for evidence of star formation in Galactic dark clouds. For this aim true colour images were created from blue, red, and infrared DSS2 plates and inspected. Follow-up I-band, Halpha, and [SII] CCD imaging and long-slit spectroscopy using the Tautenburg 2-m telescope was carried out to verify candidate objects. In the case of LDN 1415, the presence of a Herbig-Haro flow could be revealed which is henceforth named HH 892. In addition, an arcuate nebula was found which is barely seen on the DSS2 infrared plate (epoch 1996) and not detected in archival Kiso Schmidt data (epoch 2001). Thus, this nebula must have brightened by about 3.8mag in recent years.The nebula is associated with IRAS 04376+5413. The 2MASS images show a red counterpart of the IRAS source, designated as L1415-IRS. Its morphology resembles that of a bipolar young object. The luminosity of this source integrated from 0.9micron to 60micron in the low state amounts to 0.13L_sun for an assumed distance of 170pc. Thus it seems to be a young very-low mass star or it might even be of substellar mass. The current brightness increase of the nebula is caused by a FUor- or EXor-like outburst as indicated by the presence of a P Cygni profile of the Halpha line. L1415-IRS is by far the least luminous member of the sparse sample of FUor and EXor objects.Comment: 6 pages, 6 figures, accepted by A&

    A multi-wavelength census of stellar contents in the young cluster NGC 1624

    Get PDF
    We present a comprehensive multi-wavelength analysis of the young cluster NGC 1624 associated with the H II region Sh2-212 using optical UBVRI photometry, optical spectroscopy and GMRT radio continuum mapping along with the near-infrared (NIR) JHK archival data. Reddening E(B-V) and distance to the cluster are estimated to be 0.76 - 1.00 mag and 6.0 +/- 0.8 kpc, respectively. Present analysis yields a spectral class of O6.5V for the main ionizing source of the region. The distribution of YSOs in (J-H)/ (H-K) NIR colour-colour diagram shows that a majority of them have A_V ≤\le 4 mag. Based on the NIR excess characteristics, we identified 120 probable candidate YSOs in this region which yield a disk frequency of ~ 20%. These YSOs are found to have an age spread of ~ 5 Myr with a median age of ~ 2-3 Myr and a mass range of ~ 0.1 - 3.0 M⊙M_\odot. A significant number of YSOs are located close to the cluster centre and we detect an enhanced density of reddened YSOs located/projected close to the molecular clumps at the periphery of NGC 1624. This indicates that the YSOs located within the cluster core are relatively older in comparison to those located/projected near the clumps. From the radio continuum flux, spectral class of the ionizing source of the ultra-compact H II region at the periphery of Sh2-212 is estimated to be ~ B0.5V. From optical data, slope of the mass function (MF) Γ\Gamma, in the mass range 1.2≤M/M⊙<271.2 \le M/M_{\odot}<27 can be represented by a single power law with a slope -1.18 +/- 0.10, whereas the NIR data in the mass range 0.65≤M/M⊙<270.65 \le M/M_{\odot}<27 yields Γ\Gamma = -1.31 +/- 0.15. The slope of the K-band luminosity function (KLF) for the cluster is found to be 0.30 +/- 0.06 which is in agreement with the values obtained for other young clusters.Comment: Accepted for publication in MNRA

    Can nature deliver on the sustainable development goals?

    Get PDF
    The increasing availability of data and improved analytical techniques now enable better understanding of where environmental conditions and human health are tightly linked, and where investing in nature can deliver net benefits for people—especially with respect to the most vulnerable populations in developing countries. These advances bring more opportunities for interventions that can advance multiple SDGs at once. We have harmonised a suite of global datasets to explore the essential nexus of forests, poverty, and human health, an overlap of SDG numbers 1, 2, 3, 6, and 15. Our study combined demographic and health surveys for 297 112 children in 35 developing countries with data describing the local environmental conditions for each child (appendix).4 This allowed us to estimate the effect forests might have in supporting human health, while controlling for the influence of important socio-economic differences.4 We extended this work to look at how forests affect three childhood health concerns of global significance for the world's poorest people: stunting, anaemia, and diarrhoeal disease

    Genome-wide association study identifies a variant in HDAC9 associated with large vessel ischemic stroke

    Get PDF
    Genetic factors have been implicated in stroke risk but few replicated associations have been reported. We conducted a genome-wide association study (GWAS) in ischemic stroke and its subtypes in 3,548 cases and 5,972 controls, all of European ancestry. Replication of potential signals was performed in 5,859 cases and 6,281 controls. We replicated reported associations between variants close to PITX2 and ZFHX3 with cardioembolic stroke, and a 9p21 locus with large vessel stroke. We identified a novel association for a SNP within the histone deacetylase 9(HDAC9) gene on chromosome 7p21.1 which was associated with large vessel stroke including additional replication in a further 735 cases and 28583 controls (rs11984041, combined P = 1.87×10−11, OR=1.42 (95% CI) 1.28-1.57). All four loci exhibit evidence for heterogeneity of effect across the stroke subtypes, with some, and possibly all, affecting risk for only one subtype. This suggests differing genetic architectures for different stroke subtypes
    • …
    corecore