1,385 research outputs found

    Information Technology Adoption in Agricultural Operations: A Progression Path

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    Agricultural operations are not taking advantage of the Information Technology (IT) tools that exist today. As the agricultural industry continues to evolve, IT utilization is critical to the continued competitiveness/survival of individual operations. A progression path for IT adoption is defined that takes into account IT tools utilized along with impacts to operational processes. This path can be used as a tool to ease farmers into the IT world without introducing excessive change all at once. Application of this path in Extension educational programs could increase IT adoption and retention in agricultural operations

    Space Software Defined Radio Characterization to Enable Reuse

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    NASA's Space Communication and Navigation Testbed is beginning operations on the International Space Station this year. The objective is to promote new software defined radio technologies and associated software application reuse, enabled by this first flight of NASA's Space Telecommunications Radio System architecture standard. The Space Station payload has three software defined radios onboard that allow for a wide variety of communications applications; however, each radio was only launched with one waveform application. By design the testbed allows new waveform applications to be uploaded and tested by experimenters in and outside of NASA. During the system integration phase of the testbed special waveform test modes and stand-alone test waveforms were used to characterize the SDR platforms for the future experiments. Characterization of the Testbed's JPL SDR using test waveforms and specialized ground test modes is discussed in this paper. One of the test waveforms, a record and playback application, can be utilized in a variety of ways, including new satellite on-orbit checkout as well as independent on-board testbed experiments

    U. S. labor supply and demand in the long run

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    In this paper we model U.S. labor supply and demand in considerable detail in order to capture the enormous heterogeneity of the labor force and its evolution over the next 25 years. We represent labor supplies for a large number of demographic groups as responses to prices of leisure and consumption goods and services. The price of leisure is an after-tax wage rate, while the final prices of goods and services reflect the supply prices of the industries that produce them. By including demographic characteristics among the determinants of household preferences, we incorporate the expected demographic transition into our long-run projections of the U.S. labor market.Labor supply ; Labor market

    No Hubble Bubble in the Local Universe

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    Zehavi et al. (1998) have suggested that the Hubble flow within 70/h Mpc may be accelerated by the existence of a void centered on the Local Group. Its underdensity would be ~20 %, which would result in a local Hubble distortion of about 6.5 %. We have combined the peculiar velocity data of two samples of clusters of galaxies, SCI and SCII, to investigate the amplitude of Hubble distortions to 200/h Mpc. Our results are not supportive of that conclusion. The amplitude of a possible distortion in the Hubble flow within 70/h Mpc in the SCI+SCII merged data is 0.010\pm0.022. The largest, and still quite marginal, geocentric deviation from smooth Hubble flow consistent with that data set is a shell with (Delta H)/H =0.027\pm0.023, centered at hd = 101 Mpc and extending over some 30/h Mpc. Our results are thus consistent with a Hubble flow that, on distances in excess of about 50/h Mpc, is remarkably smooth.Comment: 11 pages, 1 tables, 1 figure; uses AAS LaTex; to appear in ApJ Nov 9

    The Wyoming Survey for H-alpha. I. Initial Results at z ~ 0.16 and 0.24

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    The Wyoming Survey for H-alpha, or WySH, is a large-area, ground-based, narrowband imaging survey for H-alpha-emitting galaxies over the latter half of the age of the Universe. The survey spans several square degrees in a set of fields of low Galactic cirrus emission. The observing program focuses on multiple dz~0.02 epochs from z~0.16 to z~0.81 down to a uniform (continuum+line) luminosity at each epoch of ~10^33 W uncorrected for extinction (3sigma for a 3" diameter aperture). First results are presented here for 98+208 galaxies observed over approximately 2 square degrees at redshifts z~0.16 and 0.24, including preliminary luminosity functions at these two epochs. These data clearly show an evolution with lookback time in the volume-averaged cosmic star formation rate. Integrals of Schechter fits to the extinction-corrected H-alpha luminosity functions indicate star formation rates per co-moving volume of 0.009 and 0.014 h_70 M_sun/yr/Mpc^3 at z~0.16 and 0.24, respectively. The formal uncertainties in the Schechter fits, based on this initial subset of the survey, correspond to uncertainties in the cosmic star formation rate density at the >~40% level; the tentative uncertainty due to cosmic variance is 25%, estimated from separately carrying out the analysis on data from the first two fields with substantial datasets.Comment: To appear in the Astronomical Journa

    Associations between area socioeconomic status, individual mental health, physical activity, diet and change in cardiometabolic risk amongst a cohort of Australian adults: A longitudinal path analysis

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    Presumed pathways from environments to cardiometabolic risk largely implicate health behaviour although mental health may play a role. Few studies assess relationships between these factors. This study estimated associations between area socioeconomic status (SES), mental health, diet, physical activity, and 10-year change in glycosylated haemoglobin (HbA1c), comparing two proposed path structures: 1) mental health and behaviour functioning as parallel mediators between area SES and HbA1c; and 2) a sequential structure where mental health influences behaviour and consequently HbA1c. Three waves (10 years) of population-based biomedical cohort data were spatially linked to census data based on participant residential address. Area SES was expressed at baseline using an established index (SEIFA-IEO). Individual behavioural and mental health information (Wave 2) included diet (fruit and vegetable servings per day), physical activity (meets/does not meet recommendations), and the mental health component score of the 36-item Short Form Health Survey. HbA1c was measured at each wave. Latent variable growth models with a structural equation modelling approach estimated associations within both parallel and sequential path structures. Models were adjusted for age, sex, employment status, marital status, education, and smoking. The sequential path model best fit the data. HbA1c worsened over time. Greater area SES was statistically significantly associated with greater fruit intake, meeting physical activity recommendations, and had a protective effect against increasing HbA1c directly and indirectly through physical activity behaviour. Positive mental health was statistically significantly associated with greater fruit and vegetable intakes and was indirectly protective against increasing HbA1c through physical activity. Greater SES was protective against increasing HbA1c. This relationship was partially mediated by physical activity but not diet. A protective effect of mental health was exerted through physical activity. Public health interventions should ensure individuals residing in low SES areas, and those with poorer mental health are supported in meeting physical activity recommendations

    Spitzer 70~Ī¼\mum Emission as a SFR Indicator for Sub--Galactic Regions

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    We use Spitzer 24 Ī¼\mum, 70 Ī¼\mum and ground based HĪ±\alpha data for a sample of 40 SINGS galaxies to establish a star formation rate (SFR) indicator using 70 Ī¼\mum emission for sub--galactic (āˆ¼0.05āˆ’2Ā kpc\sim0.05-2\ \rm{kpc}) line-emitting regions and to investigate limits in application. A linear correlation between 70 Ī¼\mum and SFR is found and a star formation indicator SFR(70) is proposed for line-emitting sub-galactic regions as $\rm \Sigma(SFR)\ ({M_{\odot}\cdot yr^{-1}\cdot kpc^{-2}})=9.4\times10^{-44}\ \Sigma(70)\ \rm{(ergs\cdot s^{-1}\cdot kpc^{-2})},forregionswith, for regions with 12+\rm{log(O/H)}\gtrsim8.4and and \rm \Sigma(SFR)\gtrsim10^{-3}\ (M_{\odot}\cdot yr^{-1}\cdot kpc^{-2}),witha1āˆ’, with a 1-\sigmadispersionaroundthecalibrationof dispersion around the calibration of \sim0.16dex.Wealsodiscusstheinfluenceofmetallicityonthescatterofthedata.ComparingwiththeSFRindicatorat70 dex. We also discuss the influence of metallicity on the scatter of the data. Comparing with the SFR indicator at 70 \mumforintegratedlightfromgalaxies,wefindthatthereism for integrated light from galaxies, we find that there is \sim40%excess70 excess 70 \mu$m emission in galaxies, which can be attributed to stellar populations not involved in the current star formation activity.Comment: 36 pages, 1 table, 18 figures, accepted by Ap

    Empirical ugri-UBVRc Transformations for Galaxies

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    We present empirical color transformations between Sloan Digital Sky Survey ugri and Johnson-Cousins UBVRc photometry for nearby galaxies (D < 11 Mpc). We use the Local Volume Legacy (LVL) galaxy sample where there are 90 galaxies with overlapping observational coverage for these two filter sets. The LVL galaxy sample consists of normal, non-starbursting galaxies. We also examine how well the LVL galaxy colors are described by previous transformations derived from standard calibration stars and model-based galaxy templates. We find significant galaxy color scatter around most of the previous transformation relationships. In addition, the previous transformations show systematic offsets between transformed and observed galaxy colors which are visible in observed color-color trends. The LVL-based galaxygalaxy transformations show no systematic color offsets and reproduce the observed color-color galaxy trends.Comment: Accepted for publication in MNRAS (9 pages, 6 figures, 4 tables

    Spitzer Local Volume Legacy (LVL) SEDs and Physical Properties

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    We present the panchromatic spectral energy distributions (SEDs) of the Local Volume Legacy (LVL) survey which consists of 258 nearby galaxies (D<D<11 Mpc). The wavelength coverage spans the ultraviolet to the infrared (1500 AĖš\textrm{\AA} to 24 Ī¼\mum) which is utilized to derive global physical properties (i.e., star formation rate, stellar mass, internal extinction due to dust.). With these data, we find color-color relationships and correlated trends between observed and physical properties (i.e., optical magnitudes and dust properties, optical color and specific star formation rate, and ultraviolet-infrared color and metallicity). The SEDs are binned by different galaxy properties to reveal how each property affects the observed shape of these SEDs. In addition, due to the volume-limited nature of LVL, we utilize the dwarf-dominated galaxy sample to test star formation relationships established with higher-mass galaxy samples. We find good agreement with the star-forming "main-sequence" relationship, but find a systematic deviation in the infrared "main-sequence" at low luminosities. This deviation is attributed to suppressed polycyclic aromatic hydrocarbon (PAH) formation in low metallicity environments and/or the destruction of PAHs in more intense radiation fields occurring near a suggested threshold in sSFR at a value of log(sSFRsSFR) āˆ¼\sim āˆ’-10.2.Comment: Accepted for publication in MNRAS (15 pages, 14 figures, 1 table
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