Addition theorems for spin spherical harmonics. I Preliminaries

We develop a systematic approach to deriving addition theorems for, and some other bilocal sums of, spin spherical harmonics. In this first part we establish some necessary technical results. We discuss the factorization of orbital and spin degrees of freedom in certain products of Clebsch-Gordan coefficients, and obtain general explicit results for the matrix elements in configuration space of tensor products of arbitrary rank of the position and angular-momentum operators. These results are the basis of the addition theorems for spin spherical harmonics obtained in part II

Opiniones, prácticas, barreras y predisposición al cambio, a la hora de dar consejo para dejar de fumar

ObjetivoConocer las opiniones, las prácticas actuales, las barreras percibidas y la predisposición al cambio con respecto al consejo para dejar de fumar (CF) ofertado a los pacientes por los diferentes profesionales sanitarios (PS) de atención primaria.DiseñoEstudio descriptivo, transversal.EmplazamientoCentros de salud del Área Sanitaria 9, de Madrid.ParticipantesParticiparon 480 PS, entre médicos de familia, pediatras, residentes de medicina familiar y comunitaria, y enfermería.MedicionesMediante cuestionario autocumplimentado y anónimo se recogen variables sociodemográficas, sobre actitudes, creencias y utilización de estrategias en CF y sobre barreras percibidas para darlo, así como la predisposición al cambio.ResultadosContestó al cuestionario el 75,2% (el 94,2, 61,1, 51,6 y 88% de los médicos, enfermeros, pediatras y residentes, respectivamente). El 72% pregunta de manera habitual, con un incremento hasta el 92,4% en las enfermedades relacionadas con el tabaquismo, sin diferencias respecto al sexo, el PS, el hábito tabáquico y la formación previa. El 85,8% ofrece realizar un seguimiento y el 63,5% proporciona consejos escritos. El 75% de los no fumadores se considera modelo social, frente al 40% de los fumadores. Las principales barreras son la falta de tiempo y la baja motivación en los pacientes. El 93,5% cree que es necesaria una formación específica para proporcionar CF.ConclusionesSe pregunta y se ofrece CF, independientemente del hábito tabáquico del PS. A pesar de las barreras, hay una adecuada utilización de las estrategias para proporcionar CF. Hay buena predisposición al cambio para optimizar el CF.ObjectiveTo get to know the opinions, current practices, perceived barriers and stage of change in respect to the smoking cessation advice (SCA) offered to patients by the different health professionals (HP) from primary care.DesignDescriptive cross-sectional study.LocationÁrea Sanitaria 9’s Health Centers, inMadrid, Spain.Participants480 HPs, including primary care doctors, pediatricians, primary care residents, and nursery staff.MeasurementsUsing a self-filled and anonymous questionnaire, we will gather sociodemographic variables and from the HP’s office, regarding the attitudes towards tobacco, efficiency beliefs and use of strategies in the advice, and the perceived barriers to give it, as well as the state of change.Results75.2% of the HPs filled the questionnaire (94.2%, 61.1%, 51.6%, and 88% by doctors, nurses, pediatricians, and residents respectively). 72% ask regularly, this rate increasing to 92.4% over tobacco-related diseases. No differences were made between sexes, professional types, tobacco habits, or previous attendance to courses. 85.8% offers tracing and 63.5% give written advices. Nearly 75% of non-smokers are considered social role models, that against only 40% of smokers. The main barriers found were lack of time and low motivation from the patients. 93.5% consider an specific education necessary to give efficient SCA.ConclusionsInquiries are made and SCA is given, independently of the smoking habits of the SCA. Likewise, there is a good state of change by the HPs to optimize the treatment of tobacco dependency

Debate sobre la Ley Federal del Trabajo

Se recuerda con preocupación la forma como la política laboral instrumentada en el sexenio de Carlos Salinas impuso "soluciones" a cada uno de los conflictos obrero patronales, soluciones adoptadas al margen y por sobre la normatividad laboral de esos días. Se abre boca a la discusión sin pensar que los avances tengan alguna significación, ya que muy pronto se llegó a ciertas conclusiones colectivas, de definición y proposición de temáticas tales como la libertad sindical, las condiciones de trabajo y la efectividad de las nuevas normas. Estas propuestas y reflexiones hechas en un contexto en el que la productividad en el trabajo y la capacitación para su realización, son preocupaciones de los trabajadores y sus sindicatos, en que la búsqueda de una salida a la crisis económica que padecemos puede ser encontrada sin mayores sacrificios que los que ya padece la clase trabajadora y en función a un interés nacional y popular

Intermittency in Branching Processes

We study the intermittency properties of two branching processes, one with a uniform and another with a singular splitting kernel. The asymptotic intermittency indices, as well as the leading corrections to the asymptotic linear regime are explicitly computed in an analytic framework. Both models are found to possess a monofractal spectrum with $\varphi_{q}=q-1$. Relations with previous results are discussed.Comment: 20 pages, UCLA93/TEP/2

B --> pi and B --> K transitions in partially quenched chiral perturbation theory

We study the properties of the B-->pi and B-->K transition form factors in partially quenched QCD by using the approach of partially quenched chiral perturbation theory combined with the static heavy quark limit. We show that the form factors change almost linearly when varying the value of the sea quark mass, whereas the dependence on the valence quark mass contains both the standard and chirally divergent (quenched) logarithms. A simple strategy for the chiral extrapolations in the lattice studies with Nsea=2 is suggested. It consists of the linear extrapolations from the realistically accessible quark masses, first in the sea and then in the valence quark mass. From the present approach, we estimate the uncertainty induced by such extrapolations to be within 5%.Comment: Published versio

Dependence of ∣Vub/Vcb∣|V_{ub}/V_{cb}| on Fermi momentum pFp_{_F} in ACCMM model

The Gaussian width of Fermi momentum, $p_{_F}$, is the most important parameter of the ACCMM model, and its value is essential in the determination of $|V_{ub}/V_{cb}|$ because the experimental analysis is allowed only at the end-point region of inclusive semileptonic $B$-decay spectrum. We extract the value of $|V_{ub}/V_{cb}|$ as a function of $p_{_F}$. We also calculate the parameter $p_{_F}$ in the relativistic quark model using the variational method, and obtain $p_{_F} = 0.54$ GeV which is much larger than the commonly used value, $\sim 0.3$ GeV, in experimental analyses. When we use $p_{_F} = 0.5$ GeV instead of 0.3 GeV, the value of $|V_{ub}/V_{cb}|$ from ACCMM model is increased by a factor 1.81, and can give a good agreement with Isgur {\it et al.} model.Comment: 1. Section 2 has been revised by considering the fact that in the real experimental situation the only measured quantity is the number of events in the high $E_l$ region compared to the total semi- leptonic event number. 2. The article by C. Greub and D. Wyler (Phys. Lett. B295 (1992) 293) has been included in references, which reports a similar conclusion for the value of $p_{_F}$ ($p_{_F}$=566 MeV), even though they used the different approach. 3. This article will be published in Z. Phys. C (1995

Wheezing in infants: frequency, clinical characteristics and treatment

OBJECTIVE: To estimate the frequency and describe the clinical characteristics and respective treatments of previous history of wheezing. METHODS: Infants aged 6-23 months with upper respiratory tract complaints and reporting previous wheezing were followed-up retrospectively. Data were registered on a validated standardized form. RESULTS: Out of 451 infants, 164 (36.4%; 95%CI: 31.9-41.0) had a report of prior history of wheezing, 148 (32.8%; 95%CI: 28.5-37.4) during the first year of life. The mean age at the first episode of wheezing was 5.3±3.9 months. Among those who had had their first episode before 12 months of age, 38.5% reported 3 to 6 episodes and 14.2% > 6 episodes. Mean age at first episode was lower for those with > 3 episodes in comparison with those with seis episódios. A média da idade no primeiro episódio foi menor para os que apresentaram > três episódios em comparação aos que apresentaram até dois episódios (3,2±2,7 versus 5,7±2,5 meses, p < 0,001). CONCLUSÃO: Um terço dos lactentes apresentou chiado no primeiro ano de vida. Quanto mais cedo ocorre o primeiro episódio, mais frequente é a recorrência do chiado.Fundação de Amparo à Pesquisa do Estado da Bahia (FAPESB)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade Federal da Bahia Faculdade de Medicina da Bahia Programa de Pós-Graduação em Ciências da SaúdeUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de PediatriaUniversidade de São Paulo Faculdade de Saúde Pública Departamento de EpidemiologiaEscola Bahiana de Medicina e Saúde PúblicaUFBAUFBA Faculdade de Medicina da Bahia Departamento de Anatomia Patológica e Medicina LegalUFBA Faculdade de Medicina da Bahia Departamento de PediatriaUNIFESP, EPM, Depto. de PediatriaSciEL