400 research outputs found

    A terminal assessment of stages theory : introducing a dynamic states approach to entrepreneurship

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    Stages of Growth models were the most frequent theoretical approach to understanding entrepreneurial business growth from 1962 to 2006; they built on the growth imperative and developmental models of that time. An analysis of the universe of such models (N=104) published in the management literature shows no consensus on basic constructs of the approach, nor is there any empirical confirmations of stages theory. However, by changing two propositions of the stages models, a new dynamic states approach is derived. The dynamic states approach has far greater explanatory power than its precursor, and is compatible with leading edge research in entrepreneurship

    Measurement of D*+/- meson production in jets from pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

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    This paper reports a measurement of D*+/- meson production in jets from proton-proton collisions at a center-of-mass energy of sqrt(s) = 7 TeV at the CERN Large Hadron Collider. The measurement is based on a data sample recorded with the ATLAS detector with an integrated luminosity of 0.30 pb^-1 for jets with transverse momentum between 25 and 70 GeV in the pseudorapidity range |eta| < 2.5. D*+/- mesons found in jets are fully reconstructed in the decay chain: D*+ -> D0pi+, D0 -> K-pi+, and its charge conjugate. The production rate is found to be N(D*+/-)/N(jet) = 0.025 +/- 0.001(stat.) +/- 0.004(syst.) for D*+/- mesons that carry a fraction z of the jet momentum in the range 0.3 < z < 1. Monte Carlo predictions fail to describe the data at small values of z, and this is most marked at low jet transverse momentum.Comment: 10 pages plus author list (22 pages total), 5 figures, 1 table, matches published version in Physical Review

    Search for supersymmetry in final states with jets, missing transverse momentum and one isolated lepton in sqrt{s} = 7 TeV pp collisions using 1 fb-1 of ATLAS data

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    We present an update of a search for supersymmetry in final states containing jets, missing transverse momentum, and one isolated electron or muon, using 1.04 fb^-1 of proton-proton collision data at sqrt{s} = 7 TeV recorded by the ATLAS experiment at the LHC in the first half of 2011. The analysis is carried out in four distinct signal regions with either three or four jets and variations on the (missing) transverse momentum cuts, resulting in optimized limits for various supersymmetry models. No excess above the standard model background expectation is observed. Limits are set on the visible cross-section of new physics within the kinematic requirements of the search. The results are interpreted as limits on the parameters of the minimal supergravity framework, limits on cross-sections of simplified models with specific squark and gluino decay modes, and limits on parameters of a model with bilinear R-parity violation.Comment: 18 pages plus author list (30 pages total), 9 figures, 4 tables, final version to appear in Physical Review

    Reducing heterotic M-theory to five dimensional supergravity on a manifold with boundary

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    This paper constructs the reduction of heterotic MM-theory in eleven dimensions to a supergravity model on a manifold with boundary in five dimensions using a Calabi-Yau three-fold. New results are presented for the boundary terms in the action and for the boundary conditions on the bulk fields. Some general features of dualisation on a manifold with boundary are used to explain the origin of some topological terms in the action. The effect of gaugino condensation on the fermion boundary conditions leads to a `twist' in the chirality of the gravitino which can provide an uplifting mechanism in the vacuum energy to cancel the cosmological constant after moduli stabilisation.Comment: 16 pages, RevTe

    Measurement of tau polarization in W->taunu decays with the ATLAS detector in pp collisions at sqrt(s) = 7 TeV

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    In this paper, a measurement of tau polarization in W->taunu decays is presented. It is measured from the energies of the decay products in hadronic tau decays with a single final state charged particle. The data, corresponding to an integrated luminosity of 24 pb^-1, were collected by the ATLAS experiment at the Large Hadron Collider in 2010. The measured value of the tau polarization is Ptau = -1.06 +/- 0.04 (stat) + 0.05 (syst) - 0.07 (syst), in agreement with the Standard Model prediction, and is consistent with a physically allowed 95% CL interval [-1,-0.91]. Measurements of tau polarization have not previously been made at hadron colliders.Comment: 10 pages plus author list (25 pages total), 4 figures, 4 tables, revised author list, matches published EPJC versio

    Readiness of the ATLAS liquid argon calorimeter for LHC collisions

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    The ATLAS liquid argon calorimeter has been operating continuously since August 2006. At this time, only part of the calorimeter was readout, but since the beginning of 2008, all calorimeter cells have been connected to the ATLAS readout system in preparation for LHC collisions. This paper gives an overview of the liquid argon calorimeter performance measured in situ with random triggers, calibration data, cosmic muons, and LHC beam splash events. Results on the detector operation, timing performance, electronics noise, and gain stability are presented. High energy deposits from radiative cosmic muons and beam splash events allow to check the intrinsic constant term of the energy resolution. The uniformity of the electromagnetic barrel calorimeter response along eta (averaged over phi) is measured at the percent level using minimum ionizing cosmic muons. Finally, studies of electromagnetic showers from radiative muons have been used to cross-check the Monte Carlo simulation. The performance results obtained using the ATLAS readout, data acquisition, and reconstruction software indicate that the liquid argon calorimeter is well-prepared for collisions at the dawn of the LHC era.ATLAS Collaboration, for complete list of authors see http://dx.doi.org/10.1140/epjc/s10052-010-1354-y</p

    New computer technology: special issue «Cloud technologies in education»

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    The materials of the special issue are devoted to the use of cloud technologies in open education, the formation and development of a cloud-oriented learning environment, the use of cloud-based learning support systems, cloud technologies for learning mathematics, physics and informatics. For scientists, employees of educational management bodies, teachers and students of higher educational institutions and colleges, teachers and graduate students, for all those who are interested in history, modern approaches to research and trends in the development of cloud technologies in education.Материалы спецвыпуска посвящены вопросам использования облачных технологий в открытом образовании, формирования и развития облачно ориентированной учебной среды, использованию облачно ориентированных систем поддержки обучения, средствам облачных технологий обучения математике, физике и информатике. Для научных работников, работников органов управления образованием, преподавателей и студентов высших учебных заведений и колледжей, учителей и аспирантов, для всех тех, кого интересуют история, современные подходы к исследованию и тенденции развития облачных технологий в образовании.Матеріали спецвипуску присвячені питанням використання хмарних технологій у відкритій освіті, формування та розвитку хмаро орієнтованого навчального середовища, використанню хмаро орієнтованих систем підтримки навчання, засобам хмарних технологій навчання математики, фізик та інформатики. Для науковців, працівників органів управління освітою, викладачів та студентів вищих навчальних закладів та коледжів, вчителів та аспірантів, для всіх тих, кого цікавлять історія, сучасні підходи до дослідження та тенденції розвитку хмарних технологій в освіті

    Clinical-Community Collaboration: A Strategy to Improve Retention and Outcomes in Low-Income Minority Youth in Family-Based Obesity Treatment

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    Background: Clinical-community collaboration is a promising strategy for pediatric obesity treatment, but current research is limited. This study examined the effect of a family-based treatment program embedded in a primary care clinic on retention and changes in child weight status at 1 year. Methods: Children (2-16 years, BMI ≥85th percentile, 87.0% Hispanic) and their parents were recruited from a single pediatric clinic for Healthy Hawks Primary Plus (HHP+). Children were referred by physicians and enrolled by a bilingual clinic-based recruitment coordinator. Participants received 12 weekly 2-hour sessions focused on lifestyle modification and health behavior change and then received bimonthly follow-up visits with their clinic-based physician through 1-year follow-up. Child body mass index (BMI) percentage of the 95th percentile (%BMIp95) was measured as the primary outcome at baseline, postintervention, and 1-year follow-up. Random effect multilevel models assessed changes in child weight status over time accounting for clustering by family. To further evaluate the impact, HHP+ retention and changes in child weight status were compared to a standard 12-week treatment program only. Results: HHP+ participants had significantly better retention at 1 year (73.9%, p ≤ 0.001) compared to the standard treatment program (38.3%). In HHP+, physician visit attendance was significantly correlated with retention at 1 year (r = 0.69, p ≤ 0.001), and HHP+ completers had significant reductions in %BMIp95 between baseline and 1-year follow-up (p = 0.03). Conclusion: Clinical-community partnerships might be a promising strategy to improve retention and reduce child weight status in populations currently underrepresented in obesity treatment

    Technology Components as Adjuncts to Family-Based Pediatric Obesity Treatment in Low-Income Minority Youth

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    Background: Strategies to treat pediatric obesity are needed, especially among high-need populations. Technology is an innovative approach; however, data on technology as adjuncts to in-person treatment programs are limited. Methods: A total of 64 children [body mass index (BMI) ≥85th percentile, mean age = 9.6 ± 3.1 years, 32.8% female, 84.4% Hispanic] were recruited to participate in one of three cohorts of a family-based behavioral group (FBBG) treatment program: FBBG only, TECH1, and TECH2. Rolling, nonrandomized recruitment was used to enroll participants into three cohorts from May 2014 to February 2015. FBBG began in May 2014 and received the standard, in-person 12-week treatment only (n = 21); TECH1 began in September 2014 and received FBBG plus a digital tablet equipped with a fitness app (FITNET) (n = 20); TECH2 began in February 2015 and received FBBG and FITNET, plus five individually tailored TeleMed health-coaching sessions delivered via Skype (n = 23). Child BMI z-score (BMI-z) was assessed at baseline and postintervention. Secondary aims examined weekly FBBG attendance, feasibility/acceptability of FITNET and Skype, and the effect of technology engagement on BMI-z. Results: FBBG and TECH1 participants did not show significant reductions in BMI-z postintervention [FBBG: β = -0.05(0.04), p = 0.25; TECH1: β = -0.006(0.06), p = 0.92], but TECH2 participants did [β = -0.09(0.02), p < 0.001] and TeleMed session participation was significantly associated with BMI-z reduction [β = -0.04(0.01), p = 0.01]. FITNET use and FBBG attendance were not associated with BMI-z in any cohort. Overall, participants rated the technology as highly acceptable. Conclusions: Technology adjuncts are feasible, used by hard-to-reach participants, and show promise for improving child weight status in obesity treatment programs

    Response of a Lake Michigan coastal lake to anthropogenic catchment disturbance

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    A paleolimnological investigation of post-European sediments in a Lake Michigan coastal lake was used to examine the response of Lower Herring Lake to anthropogenic impacts and its role as a processor of watershed inputs. We also compare the timing of this response with that of Lake Michigan to examine the role of marginal lakes as ‘early warning’ indicators of potential changes in the larger connected system and their role in buffering Lake Michigan against anthropogenic changes through biotic interactions and material trapping. Sediment geochemistry, siliceous microfossils and nutrient-related morphological changes in diatoms, identified three major trophic periods in the recent history of the lake. During deforestation and early settlement (pre-1845–1920), lake response to catchment disturbances results in localized increases in diatom abundances with minor changes in existing communities. In this early phase of disturbance, Lower Herring Lake acts as a sediment sink and a biological processor of nutrient inputs. During low-lake levels of the 1930s, the lake goes through a transitional period characterized by increased primary productivity and a major shift in diatom communities. Post-World War II (late 1940s–1989) anthropogenic disturbances push Lower Herring Lake to a new state and a permanent change in diatom community structure dominated by Cyclotella comensis . The dominance of planktonic summer diatom species associated with the deep chlorophyll maximum (DCM) is attributed to epilimnetic nutrient depletion. Declining Si:P ratios are inferred from increased sediment storage of biogenic silica and morphological changes in the silica content of Aulacoseira ambigua and Stephanodiscus niagarae . Beginning in the late 1940s, Lower Herring Lake functions as a biogeochemical processor of catchment inputs and a carbon, nutrient and silica sink. Microfossil response to increased nutrients and increased storage of biogenic silica in Lower Herring Lake and other regional embayments occur approximately 20–25 years earlier than in a nearby Lake Michigan site. Results from this study provide evidence for the role of marginal lakes and bays as nutrient buffering systems, delaying the impact of anthropogenic activities on the larger Lake Michigan system.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43091/1/10933_2004_Article_1688.pd
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