192 research outputs found

    Localized knowledge spillovers and patent citations: A distance-based approach

    Get PDF
    We develop a new approach to localized knowledge spillovers by incorporating the concept of control patents (Jaffe, Trajtenberg and Henderson 1993) into the distance-based test of localization (Duranton and Overman, 2005). Using microgeographic data, we identify localization distance while allowing for cross-boundary spillovers, unlike the existing literature where the extent of localized knowledge spillovers is detected at the state or metropolitan statistical area level. We revisit the recent debate by Thompson and Fox-Kean (2005) and Henderson, Jaffe and Trajtenberg (2005) on the existence of localized knowledge spillovers, and find solid evidence supporting localization, even when finer controls are used.

    Cloud optical thickness and effective particle radius derived from transmitted solar radiation measurements : Comparison with cloud radar observations

    Get PDF
    A method is presented for determining the optical thickness and effective particle radius of stratiform clouds containing liquid water drops in the absence of drizzle from transmitted solar radiation measurements. The procedure compares measurements of the cloud transmittance from the ground at water-absorbing and nonabsorbing wavelengths with lookup tables of the transmittance precomputed for plane-parallel, vertically homogeneous clouds. The optical thickness derived from the cloud transmittance may be used to retrieve vertical profiles of cloud microphysics in combination with the radar reflectivity factor. To do this, we also present an algorithm for solving the radar equation with a constraint of the optical thickness at the visible wavelength. Observations of clouds were made in August and September 2003 at Koganei, Tokyo, Japan, using a PREDE i-skyradiometer and a 95-GHz cloud radar Super Polarimetric Ice Crystal Detection and Explication Radar (SPIDER). The optical thickness and effective radius of water clouds were derived from the i-skyradiometer. Then, the vertical profile of the effective radius was retrieved from SPIDER, using the optical thickness determined from the i-skyradiometer. We found that the effective radii derived by using these two instruments were in good agreement

    Electron acceleration with improved Stochastic Differential Equation method: cutoff shape of electron distribution in test-particle limit

    Full text link
    We develop a method of stochastic differential equation to simulate electron acceleration at astrophysical shocks. Our method is based on It\^{o}'s stochastic differential equations coupled with a particle splitting, employing a skew Brownian motion where an asymmetric shock crossing probability is considered. Using this code, we perform simulations of electron acceleration at stationary plane parallel shock with various parameter sets, and studied how the cutoff shape, which is characterized by cutoff shape parameter aa, changes with the momentum dependence of the diffusion coefficient β\beta. In the age-limited cases, we reproduce previous results of other authors, a2βa\approx2\beta. In the cooling-limited cases, the analytical expectation aβ+1a\approx\beta+1 is roughly reproduced although we recognize deviations to some extent. In the case of escape-limited acceleration, numerical result fits analytical stationary solution well, but deviates from the previous asymptotic analytical formula aβa\approx\beta.Comment: corrected typos, 10 pages, 4 figures, 2 tables, JHEAp in pres

    Effective and Steady Differentiation of a Clonal Derivative of P19CL6 Embryonal Carcinoma Cell Line into Beating Cardiomyocytes

    Get PDF
    The P19CL6 cell line is a useful model to study cardiac differentiation in vitro. However, large variations were noticed in the differentiation rates among previous reports as well as our individual experiments. To overcome the unstable differentiation, we established P19CL6-A1, a new clonal derivative of P19CL6 that could differentiate into cardiomyocytes more efficiently and stably than the parent using the double stimulation with 5-Aza and DMSO based on the previous report. We also introduced a new software, Visorhythm, that can analyze the temporal variations in the beating rhythms and can chart correlograms displaying the oscillated rhythms. Using P19CL6-A1-derived cardiomyocytes and the software, we demonstrated that the correlograms could clearly display the enhancement of beating rates by cardiotonic reagents. These indicate that a combination of P19CL6-A1 and Visorhythm is a useful tool that can provide invaluable assistance in inotropic drug discovery, drug screening, and toxicity testing

    The Stellar Mass, Star Formation Rate and Dark Matter Halo Properties of LAEs at z2z\sim2

    Get PDF
    We present average stellar population properties and dark matter halo masses of z2z \sim 2 \lya emitters (LAEs) from SED fitting and clustering analysis, respectively, using \simeq 12501250 objects (NB38725.5NB387\le25.5) in four separate fields of 1\simeq 1 deg2^2 in total. With an average stellar mass of 10.2±1.8×108 M10.2\, \pm\, 1.8\times 10^8\ {\mathrm M_\odot} and star formation rate of 3.4±0.4 M yr13.4\, \pm\, 0.4\ {\mathrm M_\odot}\ {\rm yr^{-1}}, the LAEs lie on an extrapolation of the star-formation main sequence (MS) to low stellar mass. Their effective dark matter halo mass is estimated to be $4.0_{-2.9}^{+5.1} \times 10^{10}\ {\mathrm M_\odot}withaneffectivebiasof with an effective bias of 1.22^{+0.16}_{-0.18}whichislowerthanthatof which is lower than that of z \sim 2LAEs( LAEs (1.8\, \pm\, 0.3),obtainedbyapreviousstudybasedonathreetimessmallersurveyarea,withaprobabilityof), obtained by a previous study based on a three times smaller survey area, with a probability of 96\%. However, the difference in the bias values can be explained if cosmic variance is taken into account. If such a low halo mass implies a low HI gas mass, this result appears to be consistent with the observations of a high \lya escape fraction. With the low halo masses and ongoing star formation, our LAEs have a relatively high stellar-to-halo mass ratio (SHMR) and a high efficiency of converting baryons into stars. The extended Press-Schechter formalism predicts that at z=0ourLAEsaretypicallyembeddedinhaloswithmassessimilartothatoftheLargeMagellanicCloud(LMC);theywillalsohavesimilarSHMRstotheLMC,iftheirSFRsarelargelysuppressedafter our LAEs are typically embedded in halos with masses similar to that of the Large Magellanic Cloud (LMC); they will also have similar SHMRs to the LMC, if their SFRs are largely suppressed after z \sim 2$ as some previous studies have reported for the LMC itself.Comment: 34 pages, 15 figures, 6 tables. Accepted for publication in PAS

    The Development of Oral Functions in Children: A Clinical Study of Stomatognathic Dysfunction

    Get PDF
    In most countries that have reached an aging society, the feeding function among the elderly population has declined and become a serious problem. Therefore, understanding the development of human oral function is required to address this problem. However, only a few research studies have reported oral motor functions and dysfunctions in children. Our chapter describes the relationship between oral motor functions (chewing, swallowing, and breathing) and maxillofacial morphology in children. In addition, case studies on children with cerebral palsy and sleep aspiration disorders will also be introduced. This study would also like to clarify the significance of human oral function development from infancy in pediatric dentistry

    Effect of Fe3+ on Phase Relations in the Lower Mantle : Implications for Redox Melting in Stagnant Slabs

    Get PDF
    Recent studies have revealed that Earth's deep mantle may have a wider range of oxygen fugacities than previously thought. Such a large heterogeneity might be caused by material subducted into the deep mantle. However, high-pressure phase relations are poorly known in systems including Fe3+ at the top of the lower mantle, where the subducted slab may be stagnant. We therefore conducted high-pressure and high-temperature experiments using a multi-anvil apparatus to study the phase relations in a Fe3+-bearing system at 26 GPa and 1573–2073 K, at conditions prevailing at the top of the lower mantle. At temperatures below 1923 K, MgSiO3-rich bridgmanite, an Fe3+-rich oxide phase, and SiO2 coexist in the recovered sample. Quenched partial melt was observed above 1973 K, which is significantly lower than the solidus temperature of an equivalent Fe3+-free bulk composition. The partial melt obtained from the Fe3+-rich bulk composition has a higher iron content than coexisting bridgmanite, similar to the Fe2+-dominant system. The results suggest that strong mantle oxygen fugacity anomalies might alter the subsolidus and melting phase relations under lower mantle conditions. We conclude that (1) a small amount of melt may be generated from an Al-depleted region of a stagnant slab, such as subducted former banded-iron-formation, and (2) Fe3+ is not transported into the deep part of the lower mantle because of its incompatibility during melting

    Glutamatergic neurometabolite levels in the caudate are associated with the ability of rhythm production

    Get PDF
    IntroductionGlutamatergic neurometabolites play important roles in the basal ganglia, a hub of the brain networks involved in musical rhythm processing. We aimed to investigate the relationship between rhythm processing abilities and glutamatergic neurometabolites in the caudate.MethodsWe aquired Glutamatergic function in healthy individuals employing proton magnetic resonance spectroscopy. We targeted the right caudate and the dorsal anterior cingulate cortex (dACC) as a control region. Rhythm processing ability was assessed by the Harvard Beat Assessment Test (H-BAT).ResultsWe found negative correlations between the production part of the Beat Saliency Test in the H-BAT and glutamate and glutamine levels in the caudate (r = −0.693, p = 0.002) whereas there was no such association in the dACC.ConclusionThese results suggest that higher glutamatergic neurometabolite levels in the caudate may contribute to rhythm processing, especially the ability to produce meter in music precisely
    corecore