408 research outputs found

    Business experience and start-up size: buying more lottery tickets next time around?

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    This paper explores the determinants of start-up size by focusing on a cohort of 6247 businesses that started trading in 2004, using a unique dataset on customer records at Barclays Bank. Quantile regressions show that prior business experience is significantly related with start-up size, as are a number of other variables such as age, education and bank account activity. Quantile treatment effects (QTE) estimates show similar results, with the effect of business experience on (log) start-up size being roughly constant across the quantiles. Prior personal business experience leads to an increase in expected start-up size of about 50%. Instrumental variable QTE estimates are even higher, although there are concerns about the validity of the instrument

    Ultra-fast synthesis of Ti/Ru0.3Ti0.7O2 anodes with superior electrochemical properties using an ionic liquid and laser calcination

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    Here, we combine CO2 laser heating and an ionic liquid solvent (i.e., methylimidazolium hydrogensulfate HMIM+ HSO4–) as an innovative route to produce Ti/Ru0.3Ti0.7O2 anodes. For comparison purposes, the anodes were also prepared using conventional thermal treatment (in a furnace), and by the standard polymeric precursor method (also known as the Pechini method). For the laser heating, the anodes were heated at a power density of 0.4 W mm−2 up to 550 °C and kept at this temperature for 40 s, followed by instantaneous cooling. Using these conditions, the total time spent to produce an anode (considering cooling) is just 9.7 min. It represents a remarkable reduction in 446-fold and 359-fold when compared with the conventional heating for Pechini and IL methods, respectively. The laser-prepared anodes presented an increase of 63.4% and 53.8% in the voltammetric charge, while the charge transfer resistance decreases 9.6-fold and 17.3-fold using IL and Pechini methods, respectively, when compared with their correspondent furnace-made ones. Finally, superior electrocatalytic activity toward the removal of the model pollutant atrazine is observed for the laser-prepared anodes. The anode produced using laser and the IL method is the most efficient, removing 81% of atrazine in 60 min, and presents the highest kinetic rate (0.062 min−1) at the lowest energy consumption (0.179 kWh L–1). The excellent electrocatalytic response of the anodes innovatively synthesized in this study characterizes them as an encouraging advance in the search for efficient materials to be applied in the electrochemical oxidation of organic compoundsAquĂ­, combinamos el calentamiento por lĂĄser de CO 2 y un disolvente lĂ­quido iĂłnico (es decir, hidrogenosulfato de metilimidazolio HMIM + HSO 4 - ) como una ruta innovadora para producir ĂĄnodos de Ti / Ru 0,3 Ti 0,7 O 2 . Para fines de comparaciĂłn, los ĂĄnodos tambiĂ©n se prepararon utilizando un tratamiento tĂ©rmico convencional (en un horno) y por el mĂ©todo estĂĄndar de precursor polimĂ©rico (tambiĂ©n conocido como mĂ©todo Pechini). Para el calentamiento por lĂĄser, los ĂĄnodos se calentaron a una densidad de potencia de 0,4 W mm -2hasta 550 ° C y se mantiene a esta temperatura durante 40 s, seguido de enfriamiento instantĂĄneo. Usando estas condiciones, el tiempo total empleado para producir un ĂĄnodo (considerando el enfriamiento) es de solo 9,7 min. Representa una reducciĂłn notable de 446 veces y 359 veces en comparaciĂłn con el calentamiento convencional para los mĂ©todos Pechini e IL, respectivamente. Los ĂĄnodos preparados con lĂĄser presentaron un aumento de 63,4% y 53,8% en la carga voltamĂ©trica, mientras que la resistencia de transferencia de carga disminuye 9,6 veces y 17,3 veces usando los mĂ©todos IL y Pechini, respectivamente, en comparaciĂłn con sus correspondientes fabricados en horno. Finalmente, se observa una actividad electrocatalĂ­tica superior hacia la eliminaciĂłn del contaminante modelo atrazina para los ĂĄnodos preparados con lĂĄser. El ĂĄnodo producido mediante lĂĄser y el mĂ©todo IL es el mĂĄs eficiente, eliminando el 81% de la atrazina en 60 min.−1 ) con el menor consumo de energĂ­a (0,179 kWh L –1 ). La excelente respuesta electrocatalĂ­tica de los ĂĄnodos sintetizados de manera innovadora en este estudio los caracteriza como un avance alentador en la bĂșsqueda de materiales eficientes para ser aplicados en la oxidaciĂłn electroquĂ­mica de compuestos orgĂĄnicos

    Nuclear Factor (NF) ÎșB polymorphism is associated with heart function in patients with heart failure

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    <p>Abstract</p> <p>Background</p> <p>Cardiac remodeling is generally an adverse sign and is associated with heart failure (HF) progression. NFkB, an important transcription factor involved in many cell survival pathways, has been implicated in the remodeling process, but its role in the heart is still controversial. Recently, a promoter polymorphism associated with a lesser activation of the <it>NFKB1 </it>gene was also associated with Dilated Cardiomyopathy. The purpose of this study was to evaluate the association of this polymorphism with clinical and functional characteristics of heart failure patients of different etiologies.</p> <p>Methods</p> <p>A total of 493 patients with HF and 916 individuals from a cohort of individuals from the general population were investigated. The <it>NFKB1 </it>-94 insertion/deletion ATTG polymorphism was genotyped by High Resolution Melt discrimination. Allele and genotype frequencies were compared between groups. In addition, frequencies or mean values of different phenotypes associated with cardiovascular disease were compared between genotype groups. Finally, patients were prospectively followed-up for death incidence and genotypes for the polymorphism were compared regarding disease onset and mortality incidence in HF patients.</p> <p>Results</p> <p>We did not find differences in genotype and allelic frequencies between cases and controls. Interestingly, we found an association between the ATTG<sub>1</sub>/ATTG<sub>1 </sub>genotype with right ventricle diameter (<it>P </it>= 0.001), left ventricle diastolic diameter (P = 0.04), and ejection fraction (EF) (P = 0.016), being the genotype ATTG<sub>1</sub>/ATTG<sub>1 </sub>more frequent in patients with EF lower than 50% (<it>P </it>= 0.01). Finally, we observed a significantly earlier disease onset in ATTG1/ATTG<sub>1 </sub>carriers.</p> <p>Conclusion</p> <p>There is no genotype or allelic association between the studied polymorphism and the occurrence of HF in the tested population. However, our data suggest that a diminished activation of <it>NFKB1</it>, previously associated with the ATTG<sub>1</sub>/ATTG<sub>1 </sub>genotype, may act modulating on the onset of disease and, once the individual has HF, the genotype may modulate disease severity by increasing cardiac remodeling and function deterioration.</p

    Jet energy measurement with the ATLAS detector in proton-proton collisions at root s=7 TeV

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    The jet energy scale and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of √s = 7TeV corresponding to an integrated luminosity of 38 pb-1. Jets are reconstructed with the anti-kt algorithm with distance parameters R=0. 4 or R=0. 6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta pT≄20 GeV and pseudorapidities {pipe}η{pipe}<4. 5. The jet energy systematic uncertainty is estimated using the single isolated hadron response measured in situ and in test-beams, exploiting the transverse momentum balance between central and forward jets in events with dijet topologies and studying systematic variations in Monte Carlo simulations. The jet energy uncertainty is less than 2. 5 % in the central calorimeter region ({pipe}η{pipe}<0. 8) for jets with 60≀pT<800 GeV, and is maximally 14 % for pT<30 GeV in the most forward region 3. 2≀{pipe}η{pipe}<4. 5. The jet energy is validated for jet transverse momenta up to 1 TeV to the level of a few percent using several in situ techniques by comparing a well-known reference such as the recoiling photon pT, the sum of the transverse momenta of tracks associated to the jet, or a system of low-pT jets recoiling against a high-pT jet. More sophisticated jet calibration schemes are presented based on calorimeter cell energy density weighting or hadronic properties of jets, aiming for an improved jet energy resolution and a reduced flavour dependence of the jet response. The systematic uncertainty of the jet energy determined from a combination of in situ techniques is consistent with the one derived from single hadron response measurements over a wide kinematic range. The nominal corrections and uncertainties are derived for isolated jets in an inclusive sample of high-pT jets. Special cases such as event topologies with close-by jets, or selections of samples with an enhanced content of jets originating from light quarks, heavy quarks or gluons are also discussed and the corresponding uncertainties are determined. © 2013 CERN for the benefit of the ATLAS collaboration

    Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

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    The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb^-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final version published in European Physical Journal

    Observation of associated near-side and away-side long-range correlations in √sNN=5.02  TeV proton-lead collisions with the ATLAS detector

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    Two-particle correlations in relative azimuthal angle (Δϕ) and pseudorapidity (Δη) are measured in √sNN=5.02  TeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1  Όb-1 of data as a function of transverse momentum (pT) and the transverse energy (ÎŁETPb) summed over 3.1<η<4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2<|Δη|<5) “near-side” (Δϕ∌0) correlation that grows rapidly with increasing ÎŁETPb. A long-range “away-side” (Δϕ∌π) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ÎŁETPb, is found to match the near-side correlation in magnitude, shape (in Δη and Δϕ) and ÎŁETPb dependence. The resultant Δϕ correlation is approximately symmetric about π/2, and is consistent with a dominant cos⁥2Δϕ modulation for all ÎŁETPb ranges and particle pT
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