8,024 research outputs found
Form Factors for Exclusive Semileptonic --Decays
We developed the new parton model approach for exclusive semileptonic decays
of -meson to by extending the inclusive parton model, and by
combining with the results of the HQET, motivated by Drell-Yan process. Without
the nearest pole dominance ans\"atze, we {\bf derived} the dependences of
hadronic form factors on . We also calculated numerically the slope of the
Isgur-Wise function, which is consistent with the experimental results.Comment: 20 pages, RevTex, 2 ps figure files(uuencoded in seperate file
The balance-of-payments and employment-creation effects of import substitution in Kenya: an input-output approach
This paper attempts to empirically estimate the quantitative effects on domestic employment and foreign exchange saving when there is a substitution of final goods imports for domestically produced final deliveries. The framework employed for the numerical computations is based on an input-output approach. The main source of the data is the recently published Kenya Input-Output Tables for the year 1967.
The impacts of import substitution as well as import substitution possibilities for a particular sector of the Kenyan economy are estimated on the basis of the existing input-output coefficients and the average import proportions of the base year. Since for some industries the effects on induced imports would seriously be affected by domestic capacity constraints, the upper and lower limits for the effects of import substitution are additionally computed for each sector considered as a possible candidate for import substitution. The numerical results specific for each sector of origin are given in details in Section 4 of this paper
La crisis financiera global y el ejercicio del poder económico Lecciones de la experiencia de Corea del Sur
El presente artículo examina, desde una perspectiva histórica reciente, los papeles cambiantes del Estado para gobernar y regular la economía de mercado de Corea del Sur. Al observar el alcance y la naturaleza del estatismo durante los primeros periodos de la industrialización, el análisis trata las causas y consecuencias de la crisis económica actual, para luego explorar las amplias inferencias socioeconómicas del ejercicio del poder económico relativas a la reforma junto con otros prospectos de la economía, con un enfoque en los retos del futuro que enfrenta el gobierno coreano en la nueva economía global
Observation of First-Order Metal-Insulator Transition without Structural Phase Transition in VO_2
An abrupt first-order metal-insulator transition (MIT) without structural
phase transition is first observed by current-voltage measurements and
micro-Raman scattering experiments, when a DC electric field is applied to a
Mott insulator VO_2 based two-terminal device. An abrupt current jump is
measured at a critical electric field. The Raman-shift frequency and the
bandwidth of the most predominant Raman-active A_g mode, excited by the
electric field, do not change through the abrupt MIT, while, they, excited by
temperature, pronouncedly soften and damp (structural MIT), respectively. This
structural MIT is found to occur secondarily.Comment: 4 pages, 4 figure
The O(N) Nonlinear Sigma Model in the Functional Schr\"{o}dinger Picture
We present a functional Schr\"{o}dinger picture formalism of the
(1+1)-dimensional nonlinear sigma model. The energy density has been
calculated to two-loop order using the wave functional of a gaussian form, and
from which the nonperturbative mass gap of the boson fields has been obtained.
The functional Schr\"{o}dinger picture approach combined with the variational
technique is shownto describe the characteristics of the ground state of the
nonlinear sigma model in a transparent way.Comment: 13 pages, no figures, Latex fil
Action of Retinoids on Embryonic and Early Postnatal Testis Development
The current study investigates the hypothesis that retinoids have a role in embryonic testis development. The action of retinoids on testis development and the expression of retinoic acid receptors (RARα, RARβ, RARγ) were examined. In embryonic day 13 (E13; plug date 5 E0) testis organ cultures an RAR-selective agonist and alltrans retinoic acid completely inhibited seminiferous cord formation. In contrast, an RARα-selective antagonist had no effect. RT-PCR demonstrated that RARα messenger RNA (mRNA) was expressed at all developmental time points evaluated, which included embryonic day 14 (E14) through postnatal day 30 (P30). Expression of RARβ mRNA was present at E15 through P2, whereas RARγ mRNA was expressed at E18 through P2. Cellular localization of receptors by immunohistochemistry indicated that RARα was localized to the interstitium at E18 and to the seminiferous cords by P0. RARβ and RARγ were detected in both interstitium and cords at E16 and by E18 were mainly expressed in the cords. At P0 RARβ and RARγ were localized to the germ cell populations. To examine retinoid actions, the growth of P0 testis cultures were investigated. Interestingly, retinol and retinoic acid did not inhibit growth of P0 testis cultures but did inhibit the action of growth stimulators. Retinoic acid inhibited FSH, EGF, and 10% calf serum stimulated growth in P0 testis cultures. The hypothesis tested was that the inhibitory effects of retinoids on P0 testis growth may be mediated through the growth inhibitor, transforming growth factor-b (TGFβ). The action of retinoids on TGFβ mRNA expression was examined in P0 testis cultures. Retinoic acid stimulated TGFβ3 mRNA expression within 24 h and increased expression of TGFβ1 and TGFβ2 after 72 h. Retinol increased expression of TGFβ1 and TGFβ2 but not TGFβ3 after 72 h of treatment. These observations indicate that retinoic acid can influence seminiferous cord formation and testis growth. The inhibitory actions of retinoids may in part be mediated through increased expression of TGFβ isoforms
Estrategias de desarrollo para el futuro de México
El ajuste estructural en las economías en proceso de desarrollo ha sido bastante estudiado. El reclamo de los países pobres por un Nuevo Orden Económico Internacional se convirtió en una necesidad —estricta condicionalidad impuesta por los países acreedores en relación directa con la crisis de la deuda externa de llevar a cabo reformas internas de carácter estructural. El término no tiene una definición estricta. Mejorar las cuentas fiscales, abrir la economía al exterior y estimular las exportaciones, reducir subsidios, alentar al sector privado y a la inversión extranjera, adelgazar el tamaño del gobierno, privatizar, son ahora recetas de aplicación general y sin consideración clara con el estado del paciente.ITESO, A.C
Heisenberg-picture approach to the exact quantum motion of a time-dependent forced harmonic oscillator
In the Heisenberg picture, the generalized invariant and exact quantum
motions are found for a time-dependent forced harmonic oscillator. We find the
eigenstate and the coherent state of the invariant and show that the
dispersions of these quantum states do not depend on the external force. Our
formalism is applied to several interesting cases.Comment: 15 pages, two eps files, to appear in Phys. Rev. A 53 (6) (1996
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Analysis of Platforms and Functions of Mobile-Based Personal Health Record Systems
ObjectivesLittle is known about the platforms and functionalities of mobile-based personal health record (PHR) applications. The objective of this study was to investigate these two features of PHR systems.MethodsThe unit of analysis was general hospitals with more than 100 beds. This study was based on a PHR survey conducted from May 1 to June 30, 2020 and the National Health Insurance administrative data as of March 31, 2020. The study considered the platform, Android and iPhone operation system (iOS), and types of functionalities of PHR systems. Among the 316 target hospitals, 103 hospitals had adopted PHR systems. A logistic regression analysis was used.ResultsThis study found that 103 hospitals had adopted mobile-based PHR systems for their patients. Sixty-four hospitals (62.1%) were adopting both Android and iOS, but 36 (35.0%) and 3 (2.9%) hospitals were adopting Android only or iOS only, respectively. The PHR systems of hospitals adopting both platforms were more likely to have functions for viewing prescriptions, clinical diagnostic test results, and upcoming appointment status compared to those adopting a single platform (p \u3c 0.001). The number of beds (odds ratio [OR] = 1.004; confidence interval [CI], 1.001–1.007; p = 0.0029) and the number of computed tomography systems (CTs) per 100 beds (OR = 6.350; CI, 1.006–40.084; p = 0.0493) were significantly associated with the adoption of both platforms.ConclusionsMore than 60% of hospitals had adopted both Android and iOS platforms for their patients in Korea. Hospitals adopting both platforms had additional functionalities and significant association with the number of beds and CTs
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