459 research outputs found

    Opening Up the Conversation: An Exploratory Study of Science Bloggers

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    Over the past decade, science blogs have experienced tremendous growth and changes in organization, becoming an important part of what researchers have called the "evolving science media ecosystem." This thesis explores the practices and perceptions of science bloggers through 20 in-depth interviews and through a review of the blogs themselves. The research suggests areas where this medium is having a unique impact on how science communication occurs. The interview results revealed that science bloggers are motivated mainly by enjoyment, have a wide variety of routines and reporting/writing processes, strive to incorporate a personal touch, and are very engaged with readers and fellow writers through social media. This research found that science blogs have important roles in complementing other forms of science communication, opening aspects of science to wider view, promoting conversations about science through blog comments and social media, and exploiting digital tools to enhance communication

    Snapchat 'selfies': The case of disappearing data

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    Little has been written about the impact of ephemeral messaging technologies such as Snapchat, Wickr and iDelete on learner identities. The authors explore how disappearing social media may enable young people to take up a range of discourses and demonstrate discursive agency in ways that support social mobility through shifting relationships with their peers. Much of this unfolds through the transmission of digital images that promote social flexibility. The visibility, of seeing and being seen, demonstrates a Foucauldian 'gaze' where power plays out through the capacity to be visible and recognisable to others and specific practices (e.g. selfies) become normalised. Social media technologies furnish emergent spaces for underlife activity that foster this gaze. Taking up the Foucault's concept of subjectivities as discursively constituted identity categories, the authors explore the relationship between disappearing media and youth identities

    Role of rain as perception aid in assessing wind speeds and associated personal risks

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    Extreme event perception drives personal risks and, consequently, dictates household decision-making before, during, and after extreme events. Given this, increasing the extreme event perception accuracy of the public is important to improving decision-making in extreme event scenarios; however, limited research has been done on this subject. Results of a laboratory experiment, in which 76 human participants were exposed to hurricane-strength weather conditions, and asked to estimate their intensities and associated personal risks, is presented in this article. Participants were exposed to a range of identical wind speeds (20, 40, 60 mph) with (8 in/hr) and without rain. They then provided estimates of the perceived wind and rain (when present) speeds, and associated personal risks on a nominal scale of 0 to 10. Improvements in the accuracy of wind-speed perception at higher speeds were observed when rain was present in the wind field (41.5 and 69.1 mph) than when it was not (45.2 and 75.8 mph) for 40 and 60 mph wind speed exposures respectively. In contrast, risk perceptions were similar for both rain and non-rain conditions. This is particularly interesting because participants failed to estimate rain intensities (both horizontal and wind-driven rain) by a significant margin. We discuss the possible implications of rain as a perception aid to wind and the viability of using perception aids to better convey extreme weather risks. The article is concluded with revisiting discussions about the implications of past hurricane experience on wind intensity perception, personal risk assessment, and future directions in extreme weather risk perception research

    Response of Breeding Birds in the Great Plains to Low Density Urban Sprawl

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    Low-density development consumes large tracts of the rural landscape surrounding Great Plains cities. Our objective was to determine how low-density sprawl influences the presence of birds. We used logistic regression models developed for two eastern Great Plains study areas for 1966-1990 to determine the probability of occurrence of bird species on the same areas in 1902. The two areas experienced different levels of low-density urban sprawl from 1902-1990. Birds associated with forests and forest edge are expected to decrease in both areas. Some of these are species of high concern. Dickcissel, a grassland bird, is expected to increase in the area of low sprawl, whereas several bird species associated with intense development, such as the house sparrow, are expected to increase in the area with a greater level of urban sprawl. We conclude that changes in land use and human activity associated with urbanization are influencing plains bird communities

    HIghMass - High HI Mass, HI-Rich Galaxies at z∼0z\sim0: Combined HI and H2_2 Observations

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    We present resolved HI and CO observations of three galaxies from the HIghMass sample, a sample of HI-massive (MHI>1010M⊙M_{HI} > 10^{10} M_\odot), gas-rich (MHIM_{HI} in top 5%5\% for their M∗M_*) galaxies identified in the ALFALFA survey. Despite their high gas fractions, these are not low surface brightness galaxies, and have typical specific star formation rates (SFR/M∗/M_*) for their stellar masses. The three galaxies have normal star formation rates for their HI masses, but unusually short star formation efficiency scale lengths, indicating that the star formation bottleneck in these galaxies is in the conversion of HI to H2_2, not in converting H2_2 to stars. In addition, their dark matter spin parameters (λ\lambda) are above average, but not exceptionally high, suggesting that their star formation has been suppressed over cosmic time but are now becoming active, in agreement with prior Hα\alpha observations.Comment: 20 pages, 13 figure

    Additive manufacture of 3D auxetic structures by laser powder bed fusion — design influence on manufacturing accuracy and mechanical properties

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    The mechanical response of steel auxetic structures manufactured using laser-powder bed fusion was explored. The level of control exerted by the key design parameters of vertical strut length (H), re-entrant strut length (L), strut thickness (t) and re-entrant angle (ϴ) on the mechanical response was examined through a design of experiment approach with ANOVA statistical analysis methods applied. The elastic modulus in directions normal to (Ex) and parallel to (Ey) the vertical strut was found to be primarily dependent upon t and L, respectively, whereas yield strength in both test directions (σx and σy) was strongly dependent on t and L. A large variation in modulus was found between the two test directions (Ex / Ey – 1.02 ± 0.07 GPa/ 4.4 ± 0.1 GPa), whereas, yield strength showed little anisotropy (σx / σy–45 ± 6 MPa/ 45 ± 9 MPa). Poisson’s ratio parallel to the vertical strut varied considerably with geometry but not in a direction normal to the vertical strut. Deformation mechanisms were found to be different of compression in the x and y directions, being a combination of stretching of the vertical strut; compression, bending and hinging of the re-entrant strut (x); and vertical strut compression and re-entrant strut stretching and bending (y)

    Avian response to landscape change in fragmented southern Great Plains grasslands

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    We examined the dynamics of avian communities associated with fragmented grasslands in Oklahoma, USA, using long-term (1965-1995) raw (stop-level) data from the Breeding Bird Survey (BBS). Aerial photography was used to document changes in land cover type and landscape pattern as affected by woody plant (mostly Juniperus virginiana L.) encroachment and concurrent cropland conversions to agricultural grassland under the Conservation Reserve Program (CRP). Rank trend analysis identified species with significant population trends, and canonical correspondence analysis (CCA) was used to identify important environmental gradients from a group of descriptive habitat variables that included land cover type composition and indices of vegetation cover, landscape pattern, and grassland patch structure.Avian community structure shifted along gradients of increasing woody plant cover and indicators of continuing landscape fragmentation. Open-habitat generalists, woodland, and successional scrub species generally increased, whereas many grassland species decreased. In some instances, neotropical migrants responded positively to increasing woody vegetation. Some grassland birds also showed a positive response to increases in agricultural grassland, but only in areas of severe juniper encroachment. Most grassland species exhibited consistent declines related to the influx of woody vegetation and associated landscape changes.Woody plant encroachment into southern Great Plains grasslands already fragmented by agricultural activity represents a conservation management dilemma. Although woody vegetation in remnant native prairies may provide habitat for some declining neotropical migrants that require shrubby areas, grassland structure and suitability is compromised for many declining grassland-endemic birds. Cropland conversion to agricultural grassland does appear to provide suitable habitat for some grassland species. However, this benefit appears to be limited to areas where woody plant invasion into grasslands is relatively advanced, and may have only a temporary effect, as most CRP areas are likely to return to agricultural production in the near future. Changes are needed in grassland management practices to restrict woody plant encroachment and fragmentation; otherwise, continued declines in grassland bird populations can be expected.Peer reviewedRangeland Ecology and ManagementPlant and Soil SciencesForestr

    Galaxy Zoo: morphological classification of galaxy images from the Illustris simulation

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    Modern large-scale cosmological simulations model the universe with increasing sophistication and at higher spatial and temporal resolutions. These ongoing enhancements permit increasingly detailed comparisons between the simulation outputs and real observational data. Recent projects such as Illustris are capable of producing simulated images that are designed to be comparable to those obtained from local surveys. This paper tests the degree to which Illustris achieves this goal across a diverse population of galaxies using visual morphologies derived from Galaxy Zoo citizen scientists. Morphological classifications provided by these volunteers for simulated galaxies are compared with similar data for a compatible sample of images drawn from the Sloan Digital Sky Survey (SDSS) Legacy Survey. This paper investigates how simple morphological characterization by human volunteers asked to distinguish smooth from featured systems differs between simulated and real galaxy images. Significant differences are identified, which are most likely due to the limited resolution of the simulation, but which could be revealing real differences in the dynamical evolution of populations of galaxies in the real and model universes. Specifically, for stellar masses, a substantially larger proportion of Illustris galaxies that exhibit disk-like morphology or visible substructure, relative to their SDSS counterparts. Toward higher masses, the visual morphologies for simulated and observed galaxies converge and exhibit similar distributions. The stellar mass threshold indicated by this divergent behavior confirms recent works using parametric measures of morphology from Illustris simulated images. When , the Illustris data set contains substantially fewer galaxies that classifiers regard as unambiguously featured. In combination, these results suggest that comparison between the detailed properties of observed and simulated galaxies, even when limited to reasonably massive systems, may be misleading
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