190 research outputs found

    Recent cropping frequency, expansion, and abandonment in Mato Grosso, Brazil had selective land characteristics

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    This letter uses satellite remote sensing to examine patterns of cropland expansion, cropland abandonment, and changing cropping frequency in Mato Grosso, Brazil from 2001 to 2011. During this period, Mato Grosso emerged as a globally important center of agricultural production. In 2001, 3.3 million hectares of mechanized agriculture were cultivated in Mato Grosso, of which 500 000 hectares had two commercial crops per growing season (double cropping). By 2011, Mato Grosso had 5.8 million hectares of mechanized agriculture, of which 2.9 million hectares were double cropped. We found these agricultural changes to be selective with respect to land attributes —significant differences (p \u3c 0.001) existed between the land attributes of agriculture versus nonagriculture, single cropping versus double cropping, and expansion versus abandonment. Many of the land attributes (elevation, slope, maximum temperature, minimum temperature, initial soy transport costs, and soil) that were associated with an increased likelihood of expansion were associated with a decreased likelihood of abandonment (p \u3c 0.001). While land similar to agriculture and double cropping in 2001 was much more likely to be developed for agriculture than all other land, new cropland shifted to hotter, drier, lower locations that were more isolated from agricultural infrastructure (p \u3c 0.001). The scarcity of high quality remaining agricultural land available for agricultural expansion in Mato Grosso could be contributing to the slowdown in agricultural expansion observed there over 2006 to 2011. Land use policy analyses should control for land scarcity constraints on agricultural expansion

    Location Preferences of Family Firms: Strategic Decision Making or “Home Sweet Home”?

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    Selecting a business location is among the most important strategic decisions for family firms. Yet the separate demands of the family and the business often prove difficult to balance. A comparison of location preferences in family and nonfamily firms provides insight into the family influence on strategic decision making.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67069/2/10_1111_j_1741-6248_1992_00271_x.pd

    Massively distributed authorship of academic papers

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    Wiki-like or crowdsourcing models of collaboration can provide a number of benefits to academic work. These techniques may engage expertise from different disciplines, and potentially increase productivity. This paper presents a model of massively distributed collaborative authorship of academic papers. This model, developed by a collective of thirty authors, identifies key tools and techniques that would be necessary or useful to the writing process. The process of collaboratively writing this paper was used to discover, negotiate, and document issues in massively authored scholarship. Our work provides the first extensive discussion of the experiential aspects of large-scale collaborative research.Peer ReviewedPostprint (author's final draft

    Identification of Candidate Genes for Dyslexia Susceptibility on Chromosome 18

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    Background: Six independent studies have identified linkage to chromosome 18 for developmental dyslexia or general reading ability. Until now, no candidate genes have been identified to explain this linkage. Here, we set out to identify the gene(s) conferring susceptibility by a two stage strategy of linkage and association analysis. Methodology/Principal Findings: Linkage analysis: 264 UK families and 155 US families each containing at least one child diagnosed with dyslexia were genotyped with a dense set of microsatellite markers on chromosome 18. Association analysis: Using a discovery sample of 187 UK families, nearly 3000 SNPs were genotyped across the chromosome 18 dyslexia susceptibility candidate region. Following association analysis, the top ranking SNPs were then genotyped in the remaining samples. The linkage analysis revealed a broad signal that spans approximately 40 Mb from 18p11.2 to 18q12.2. Following the association analysis and subsequent replication attempts, we observed consistent association with the same SNPs in three genes; melanocortin 5 receptor (MC5R), dymeclin (DYM) and neural precursor cell expressed, developmentally down-regulated 4-like (NEDD4L). Conclusions: Along with already published biological evidence, MC5R, DYM and NEDD4L make attractive candidates for dyslexia susceptibility genes. However, further replication and functional studies are still required.Publisher PDFPeer reviewe

    Inflation and Dark Energy from spectroscopy at z > 2

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    Production of Single W Bosons at LEP

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    We report on the observation of single W boson production in a data sample collected by the L3 detector at LEP2. The signal consists of large missing energy final states with a single energetic lepton or two hadronic jets. The cross-section is measured to be 0.610.33+0.43±0.05  pb0.61^{+0.43}_{-0.33} \pm 0.05 \; \rm{pb} at the centre of mass energy \sqrt{s}=172 \GeV{}, consistent with the Standard Model expectation. From this measurement the following limits on the anomalous γ\gammaWW gauge couplings are derived at 95\% CL: 3.6Δκγ1.5\rm -3.6 \Delta \kappa_\gamma 1.5 and 3.6λγ3.6\rm -3.6 \lambda_\gamma 3.6

    Measurement of the Average Lifetime of b-Hadrons in Z Decays

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    We present a measurement of the average b-hadron lifetime τb{\rm \tau_b} at the e+e\mathrm{e^+e^-} \, collider LEP. Using hadronic Z decays collected in the period from 1991 to 1994, two independent analyses have been performed. In the first one, the b-decay position is reconstructed as a secondary vertex of hadronic b-decay particles. The second analysis is an updated measurement of τb{\rm \tau_b} using the impact parameter of leptons with high momentum and high transverse momentum. The combined result is \begin{center} τb=[1549±9(stat)±15(syst)]  fs{\rm \tau_b= [ 1549 \pm 9 \, (stat) \, \pm 15 \, (syst) ] \; fs \,} . \end{center} In addition, we measure the average charged b-decay multiplicity nb{\rm \langle n_{\rm b}} \rangle and the normalized average b-energy xEb{\rm \langle x_E \rangle_{\rm b}} at LEP to be \begin{center} nb=4.90±0.04 (stat)±0.11(syst){\rm \langle n_{\rm b} \rangle = 4.90 \pm 0.04 \ (stat) \pm 0.11 \, (syst)} , \end{center} \begin{center} xEb=0.709±0.004(stat+syst).{\rm \langle x_E \rangle_{\rm b} = 0.709 \pm 0.004 \, (stat + syst).} \end{center
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