4,451 research outputs found

    Supplemental Nutrition Assistance Program Education Evaluation and Database System

    Get PDF
    Reporting requirements for capturing data on the delivery of Supplemental Nutrition Assistance Program Education (SNAP-Ed) have evolved. University of Minnesota (U of M) Extension developed the SNAP Education Evaluation and Database System (SEEDS) to capture unduplicated participant information for SNAP-Ed programming conducted by U of M Extension across the state of Minnesota. The data collected in SEEDS have utility related to both managing programs and measuring the success of programs at local, regional, and state levels. Extension professionals in other states may benefit from developing a similar centralized database for collecting SNAP-Ed data

    Determining the structure of Ru(0001) from low-energy electron diffraction of a single terrace

    Full text link
    While a perfect hcp (0001) surface has three-fold symmetry, the diffraction patterns commonly obtained are six-fold symmetric. This apparent change in symmetry occurs because on a stepped surface, the atomic layers on adjacent terraces are rotated by 180 degrees. Here we use a Low-Energy Electron Microscope to acquire the three-fold diffraction pattern from a single hcp Ru terrace and measure the intensity-vs-energy curves for several diffracted beams. By means of multiple scattering calculations fitted to the experimental data with a Pendry R-factor of 0.077, we find that the surface is contracted by 3.5(+-0.9) at 456 K.Comment: 10 pages, 4 figures. Corrected some typos, added more details. Accepted for publication in Surface Science (Letters

    Evolution of avalanche conducting states in electrorheological liquids

    Get PDF
    Charge transport in electrorheological fluids is studied experimentally under strongly nonequlibrium conditions. By injecting an electrical current into a suspension of conducting nanoparticles we are able to initiate a process of self-organization which leads, in certain cases, to formation of a stable pattern which consists of continuous conducting chains of particles. The evolution of the dissipative state in such system is a complex process. It starts as an avalanche process characterized by nucleation, growth, and thermal destruction of such dissipative elements as continuous conducting chains of particles as well as electroconvective vortices. A power-law distribution of avalanche sizes and durations, observed at this stage of the evolution, indicates that the system is in a self-organized critical state. A sharp transition into an avalanche-free state with a stable pattern of conducting chains is observed when the power dissipated in the fluid reaches its maximum. We propose a simple evolution model which obeys the maximum power condition and also shows a power-law distribution of the avalanche sizes.Comment: 15 pages, 6 figure

    How non-linear scaling relations unify dwarf and giant elliptical galaxies

    Full text link
    Dwarf elliptical galaxies are frequently excluded from bright galaxy samples because they do not follow the same linear relations in diagrams involving effective half light radii R_e or mean effective surface brightnesses _e. However, using two linear relations which unite dwarf and bright elliptical galaxies we explain how these lead to curved relations when one introduces either the half light radius or the associated surface brightness. In particular, the curved _e - R_e relation is derived here. This and other previously misunderstood curved relations, once heralded as evidence for a discontinuity between faint and bright elliptical galaxies at M_B ~ -18 mag, actually support the unification of such galaxies as a single population whose structure (i.e. stellar concentration) varies continuously with stellar luminosity and mass.Comment: 4 pages including 2 figures, to appear in "A Universe of dwarf galaxies", Conf. Proc. (Lyon, June 14-18, 2010

    A Dereplication and Bioguided Discovery Approach to Reveal New Compounds from a Marine-Derived Fungus Stilbella fimetaria

    Get PDF
    A marine-derived Stilbella fimetaria fungal strain was screened for new bioactive compounds based on two different approaches: (i) bio-guided approach using cytotoxicity and antimicrobial bioassays; and (ii) dereplication based approach using liquid chromatography with both diode array detection and high resolution mass spectrometry. This led to the discovery of several bioactive compound families with different biosynthetic origins, including pimarane-type diterpenoids and hybrid polyketide-non ribosomal peptide derived compounds. Prefractionation before bioassay screening proved to be a great aid in the dereplication process, since separate fractions displaying different bioactivities allowed a quick tentative identification of known antimicrobial compounds and of potential new analogues. A new pimarane-type diterpene, myrocin F, was discovered in trace amounts and displayed cytotoxicity towards various cancer cell lines. Further media optimization led to increased production followed by the purification and bioactivity screening of several new and known pimarane-type diterpenoids. A known broad-spectrum antifungal compound, ilicicolin H, was purified along with two new analogues, hydroxyl-ilicicolin H and ilicicolin I, and their antifungal activity was evaluated

    Blue space as caring space – water and the cultivation of care in social and environmental practice

    Get PDF
    This paper studies three sites or ‘landscapes of care’ in Leeds, Bristol and London where water and associated built and natural environments are used to co-construct and facilitate forms of social and environmental care. Our research narrates the ways in which blue spaces are cultivated for the production of particular forms of caring bodies and sensibilities. Interpreting care as both a doing (caring for) and emotion (caring about), we draw attention to the diverse practices and distributed nature of care in these environments. Our paper has three main insights. First, we draw attention to the role of water as both a material and site of care. Second, we identify a range of more-than-human benefits associated with blue spaces and how these emerge via collaborative, non-linear and reciprocal forms of care. Third, we argue that by understanding how care works in everyday social practice, new forms of ecological care and pro-environmental ways of living with the world can emerge

    Galaxy Harassment and the Evolution of Clusters of Galaxies

    Get PDF
    Disturbed spiral galaxies with high rates of star formation pervaded clusters of galaxies just a few billion years ago, but nearby clusters exclude spirals in favor of ellipticals. ``Galaxy harassment" (frequent high speed galaxy encounters) drives the morphological transformation of galaxies in clusters, provides fuel for quasars in subluminous hosts and leaves detectable debris arcs. Simulated images of harassed galaxies are strikingly similar to the distorted spirals in clusters at z0.4z \sim 0.4 observed by the Hubble Space Telescope.Comment: Submitted to Nature. Latex file, 7 pages, 10 photographs in gif and jpeg format included. 10 compressed postscript figures and text available using anonymous ftp from ftp://ftp-hpcc.astro.washington.edu/pub/hpcc/moore/ (mget *) Also available at http://www-hpcc.astro.washington.edu/papers

    Nature vs. nurture in the low-density environment: structure and evolution of early-type dwarf galaxies in poor groups

    Get PDF
    We present the stellar population properties of 13 dwarf galaxies residing in poor groups (low-density environment, LDE) observed with VIMOS@VLT. Ages, metallicities, and [alpha/Fe] ratios were derived from the Lick indices Hbeta, Mgb, Fe5270 and Fe5335 through comparison with our simple stellar population (SSP) models accounting for variable [alpha/Fe] ratios. For a fiducial subsample of 10 early-type dwarfs we derive median values and scatters around the medians of 5.7 \pm 4.4 Gyr, -0.26 \pm 0.28, and -0.04 \pm 0.33 for age, log Z/Zsun, and [alpha/Fe], respectively. For a selection of bright early-type galaxies (ETGs) from the Annibali et al.2007 sample residing in comparable environment we derive median values of 9.8 \pm 4.1 Gyr, 0.06 \pm 0.16, and 0.18 \pm 0.13 for the same stellar population parameters. It follows that dwarfs are on average younger, less metal rich, and less enhanced in the alpha-elements than giants, in agreement with the extrapolation to the low mass regime of the scaling relations derived for giant ETGs. From the total (dwarf + giant) sample we derive that age \propto sigma^{0.39 \pm 0.22}, Z \propto sigma^{0.80 \pm 0.16}, and alpha/Fe \propto sigma^{0.42 \pm 0.22}. We also find correlations with morphology, in the sense that the metallicity and the [alpha/Fe] ratio increase with the Sersic index n or with the bulge-to-total light fraction B/T. The presence of a strong morphology-[alpha/Fe] relation appears to be in contradiction to the possible evolution along the Hubble sequence from low B/T (low n) to high B/T (high n) galaxies. We also investigate the role played by environment comparing the properties of our LDE dwarfs with those of Coma red passive dwarfs from the literature. We find possible evidence that LDE dwarfs experienced more prolonged star formations than Coma dwarfs, however larger data samples are needed to draw more firm conclusions.Comment: Accepted for publication on A&

    Do cancer cells undergo phenotypic switching? The case for imperfect cancer stem cell markers

    Get PDF
    The identification of cancer stem cells in vivo and in vitro relies on specific surface markers that should allow to sort cancer cells in phenotypically distinct subpopulations. Experiments report that sorted cancer cell populations after some time tend to express again all the original markers, leading to the hypothesis of phenotypic switching, according to which cancer cells can transform stochastically into cancer stem cells. Here we explore an alternative explanation based on the hypothesis that markers are not perfect and are thus unable to identify all cancer stem cells. Our analysis is based on a mathematical model for cancer cell proliferation that takes into account phenotypic switching, imperfect markers and error in the sorting process. Our conclusion is that the observation of reversible expression of surface markers after sorting does not provide sufficient evidence in support of phenotypic switching

    A Novel Model of Mixed Vascular Dementia Incorporating Hypertension in a Rat Model of Alzheimer's Disease.

    Get PDF
    Alzheimer's disease (AD) and mixed dementia (MxD) comprise the majority of dementia cases in the growing global aging population. MxD describes the coexistence of AD pathology with vascular pathology, including cerebral small vessel disease (SVD). Cardiovascular disease increases risk for AD and MxD, but mechanistic synergisms between the coexisting pathologies affecting dementia risk, progression and the ultimate clinical manifestations remain elusive. To explore the additive or synergistic interactions between AD and chronic hypertension, we developed a rat model of MxD, produced by breeding APPswe/PS1ΔE9 transgenes into the stroke-prone spontaneously hypertensive rat (SHRSP) background, resulting in the SHRSP/FAD model and three control groups (FAD, SHRSP and non-hypertensive WKY rats, n = 8-11, both sexes, 16-18 months of age). After behavioral testing, rats were euthanized, and tissue assessed for vascular, neuroinflammatory and AD pathology. Hypertension was preserved in the SHRSP/FAD cross. Results showed that SHRSP increased FAD-dependent neuroinflammation (microglia and astrocytes) and tau pathology, but plaque pathology changes were subtle, including fewer plaques with compact cores and slightly reduced plaque burden. Evidence for vascular pathology included a change in the distribution of astrocytic end-foot protein aquaporin-4, normally distributed in microvessels, but in SHRSP/FAD rats largely dissociated from vessels, appearing disorganized or redistributed into neuropil. Other evidence of SVD-like pathology included increased collagen IV staining in cerebral vessels and PECAM1 levels. We identified a plasma biomarker in SHRSP/FAD rats that was the only group to show increased Aqp-4 in plasma exosomes. Evidence of neuron damage in SHRSP/FAD rats included increased caspase-cleaved actin, loss of myelin and reduced calbindin staining in neurons. Further, there were mitochondrial deficits specific to SHRSP/FAD, notably the loss of complex II, accompanying FAD-dependent loss of mitochondrial complex I. Cognitive deficits exhibited by FAD rats were not exacerbated by the introduction of the SHRSP phenotype, nor was the hyperactivity phenotype associated with SHRSP altered by the FAD transgene. This novel rat model of MxD, encompassing an amyloidogenic transgene with a hypertensive phenotype, exhibits several features associated with human vascular or "mixed" dementia and may be a useful tool in delineating the pathophysiology of MxD and development of therapeutics
    corecore