623 research outputs found

    The pion-pion scattering amplitude

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    We obtain reliable ππ\pi\pi scattering amplitudes consistent with experimental data, both at low and high energies, and fulfilling appropriate analyticity properties. We do this by first fitting experimental low energy (s1/21.42GeVs^{1/2}\leq1.42 {\rm GeV}) phase shifts and inelasticities with expressions that incorporate analyticity and unitarity. In particular, for the S wave with isospin~0, we discuss in detail several sets of experimental data. This provides low energy partial wave amplitudes that summarize the known experimental information. Then, we impose Regge behaviour as follows from factorization and experimental data for the imaginary parts of the scattering amplitudes at higher energy, and check fulfillment of dispersion relations up to 0.925 GeV. This allows us to improve our fits. The ensuing ππ\pi\pi scattering amplitudes are then shown to verify dispersion relations up to 1.42 GeV, as well as stus - t - u crossing sum rules and other consistency conditions. The improved parametrizations therefore provide a reliable representation of pion-pion amplitudes with which one can test chiral perturbation theory calculations, pionium decays, or use as input for CP-violating KK decays. In this respect, we find [a0(0)a0(2)]2=(0.077±0.008)Mπ1[a_0^{(0)}-a_0^{(2)}]^2=(0.077\pm0.008) M^{-1}_\pi and δ0(0)(mK2)δ0(2)(mK2)=52.9±1.6o\delta_0^{(0)}(m^2_K)-\delta_0^{(2)}(m^2_K)=52.9\pm1.6^{\rm o}.Comment: Version to be published in Phys. Rev. D. Plain TeX file. (minor changes). 16 figures (some multiple

    The role of antibiotics in the treatment of chronic prostatitis: A consensus statement

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    Practical guidelines for the diagnosis and treatment of chronic prostatitis are presented. Chronic prostatitis is classified as chronic bacterial prostatitis (culture-positive) and chronic inflammatory prostatitis (culture-negative). If chronic bacterial prostatitis is suspected, based on relevant symptoms or recurrent UTIs, underlying urological conditions should be excluded by the following tests: rectal examination, midstream urine culture and residual urine. The diagnosis should be confirmed by the Meares and Stamey technique. Antibiotic therapy is recommended for acute exacerbations of chronic prostatitis, chronic bacterial prostatitis and chronic inflammatory prostatitis, if there is clinical, bacteriological or supporting immunological evidence of prostate infection. Unless a patient presents with fever, antibiotic treatment should not be initiated immediately except in cases of acute prostatitis or acute episodes in a patient with chronic bacterial prostatitis. The work-up, with the appropriate investigations should be done first, within a reasonable time period which, preferably, should not be longer than 1 week. During this period, nonspecific treatment, such as appropriate analgesia to relieve symptoms, should be given. The minimum duration of antibiotic treatment should be 2-4 weeks. If there is no improvement in symptoms, treatment should be stopped and reconsidered. However, if there is improvement, it should be continued for at least a further 2-4 weeks to achieve clinical cure and, hopefully, eradication of the causative pathogen. Antibiotic treatment should not be given for 6-8 weeks without an appraisal of its effectiveness. Currently used antibiotics are reviewed. Of these, the fluoroquinolones ofloxacin and ciprofloxacin are recommended because of their favourable antibacterial spectrum and pharmacokinetic profile. A number of clinical trials are recommended and a standard study design is proposed to help resolve some outstanding issues

    On the precision of chiral-dispersive calculations of ππ\pi\pi scattering

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    We calculate the combination 2a0(0)5a0(2)2a_0^{(0)}-5a_0^{(2)} (the Olsson sum rule) and the scattering lengths and effective ranges a1a_1, a2(I)a_2^{(I)} and b1b_1, b2(I)b_2^{(I)} dispersively (with the Froissart--Gribov representation) using, at low energy, the phase shifts for ππ\pi\pi scattering obtained by Colangelo, Gasser and Leutwyler (CGL) from the Roy equations and chiral perturbation theory, plus experiment and Regge behaviour at high energy, or directly, using the CGL parameters for aas and bbs. We find mismatch, both among the CGL phases themselves and with the results obtained from the pion form factor. This reaches the level of several (2 to 5) standard deviations, and is essentially independent of the details of the intermediate energy region (0.82E1.420.82\leq E\leq 1.42 GeV) and, in some cases, of the high energy behaviour assumed. We discuss possible reasons for this mismatch, in particular in connection with an alternate set of phase shifts.Comment: Version to appear in Phys. Rev. D. Graphs and sum rule added. Plain TeX fil

    Beyond the curriculum: what role do non-curricular activities play in student engagement?;

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    peer reviewedINTRODUCTION. This article analyses the role that non-curricular activities play in the school engagement of young people with different socio-demographic profiles, taking into account the role of schools. METHOD. A hierarchical linear analysis model has been used to measure the differences between schools, controlling the individual characteristics of the students from the data of a survey carried out among 2.056 students who were in their 10th year of schooling in 27 schools based in Barcelona. Four models are examined in the analysis: firstly, sociodemographic variables are introduced, then non-curricular activities carried out by young people both within and outside the high school, and finally centre variables. RESULTS. The results show that noncurricular activities act as mediators of the family educational level in explaining emotional and cognitive engagement —not behavioural engagement—, and sex and origin remain influential. Finally, the level of participation within centers appears to be significant only for behavioral engagement, mediating the effect of the complexity and comprehensiveness of the center. DISCUSSION. Based on the results obtained, it is possible to deepen the debate on the importance of non-curricular activities for the school engagement of young people, as well as the role that schools have in promoting the school involvement of their students. © 2020, Sociedad Espanola de Pedagogia. All rights reserved

    Ansiedad competitiva y clima motivacional en jóvenes futbolistas de competición, en relación con las habilidades y el rendimiento percibido por sus entrenadores

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    En este estudio se analizan las relaciones existentes entre la ansiedad competitiva (en sus facetas cognitiva y somática) y el clima motivacional percibido (de ego y de maestría) en una población de 54 jóvenes futbolistas decompetición de edad media de 9,45 años, respecto de la percepción de sus habilidades y rendimiento deportivos por parte de sus 4 entrenadores, que también participaron en el estudio. Para ello se les administró las versiones españolas del SAS-2 (Sport Anxiety Scale-2, Smith, Smoll, Cumming y Grossbard, 2006) y el MCSYS (Motivational Climate Scale for Youth Sports,Smith, Cumming y Smoll, 2008), así como dos escalas ad hoc para evaluar la percepción de su habilidad y rendimiento. Los resultados muestran, por una parte, que los jóvenes futbolistas perciben y discriminan claramente los climas motivacionales, que se distribuyen casi al 50% entre ego y maestría; por otra, que aparece ansiedad competitiva, aunque más cognitiva que somática, y que no existe relación significativa con las percepciones de habilidad y rendimiento por parte de los entrenadores. Finalmente, estos resultados se discuten y se comparan con otros similares en poblaciones preadolescentesThis study analysed the relationships between competitive anxiety (both cognitive and somatic) and perceived motivational climate (ego and mastery) in 54 young competitive soccer players (mean age: 9.45 years), related to their four coaches' perceptions of the soccer players' skills and performance. We administered the Spanish versions of the SAS-2 (Sport Anxiety Scale-2, Smith, Smoll, Cumming and Grossbard, 2006) and the MCSYS (Motivational Climate Scale for Youth Sports, Smith, Cumming and Smoll, 2008), along with two ad hoc scales to evaluate perceived skills and performance.The results show that 1) young players perceived and discriminated clearly between motivational climates (which were more or less equally distributed between ego and mastery orientations), 2) some performance-related anxiety (mostly cognitive rather than somatic) appeared and 3) no significant relationships were found between their coaches' perceptions of their skills and their performance. Lastly, the results are discussed and compared with similar results from preadolescent player

    Genetics: Is LADA just late onset type 1 diabetes?

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    Background: There is a controversy regarding Latent Autoimmune Diabetes in Adults (LADA) classification and whether it should be considered a slowly progressing form of type 1 (T1) diabetes (DM) or a distinct type of DM altogether. Methods: This cross-sectional study assessed major genes associated with T1DM (class II Results: A total of 578 participants were included: 248 with T1DM (70 diagnosed after the age of 30), 256 with T2DM and 74 with LADA. High risk HLA alleles were significantly more frequent in LADA than in T2DM, whereas the opposite was true for protective alleles. We found a lower frequency of the high-risk DRB1*04-DQB1*03:02-DQA1*03:01 haplotype in LADA (21.1%) than in the overall T1DM (34.7%) (p\u3c0.05), whereas no differences were found between these groups for DRB1*03-DQB1*02:01-DQA1*05:01 or for protective alleles. Only 12% the overall T1DM group had no risk alleles vs 30% of LADA (p\u3c0.0005). However, HLA allele distribution was similar in LADA and T1DM diagnosed after the age of 30. A total of 506 individuals (195 with T1DM [21 diagnosed after age 30] 253 with T2DM and 58 with LADA) were genotyped for the Conclusion: In this relatively small cross-sectional study, the genetic profile of subjects with LADA showed a similar T1DM-related risk allele distribution as in participants with T1DM diagnosed after the age of 30, but fewer risk alleles than those diagnosed before 30. Differences were present for HLA, as well a

    Opinión de los estudiantes de farmacia sobre la calidad de las prácticas en el ámbito de la tecnología farmacéutica.

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    Se presentan aquí los avances de una investigación, todavía en curso, que recoge las aportaciones de los primeros graduados sobre las competencias alcanzadas,así como la relación entre la consecución de dichas competencias y los procesos de evaluación y metodológicos seguidos. Las competencias son referentes básicos de los grados, y la mirada del graduado es especialmente interesante porque complementa la del docente, al tiempo que aporta relevantes aspectos para la mejora de la docencia

    Most worrysome weeds in Spain

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    Se presentan los resultados de una encuesta realizada durante el periodo de junio a octubre de 2014, y en la que participaron 315 técnicos de campo de toda España. Los datos están disponibles en Internet y su análisis permite concluir que a) las malas hierbas preocupan tanto como las plagas y enfermedades; b) respecto a los métodos de control, el control químico con herbicidas es el más usado y el considerado más eficaz; se han detectado las malas hierbas más preocupantes en una serie de cultivos, incluyendo el motivo de la preocupación. En cultivos leñosos, destaca “Conyza” por su dificultad de control, en arroz destacan “Echinochloa” y “Cyperus”; en algodón y maíz preocupan “Abutilon”, “Chenopodium”, “Cyperus”, Echinochloa y Sorghum; en cultivos extensivos de secano, la preocupación no está tan concentrada en pocas especies, destacando malas hierbas gramíneas en trigo y cebada junto con Centaurea, que es considerada preocupante adicionalmente en el cultivo del girasol. Finalmente, se seleccionan arvenses de preocupación creciente, entre las que destacan “Abutilon”, “Centaurea”, “Chenopodium” y “Sorghum”.Since June to October 2014, 315 Spanish field advisors participated in a survey. Data is available on internet and results show that a) weeds are as worrying as other pests and diseases; b) chemical control is the most used weed control method and is considered to be the most efficient one; c) knowledge transfer in weed management is largely dependant on herbicide industry; d) most worrying weeds have been identified for several crops, as well as the reasons why they are considered worrysome. In permanent crops, “Conyza” is refered to be by far the worst weed, mainly because it is difficult to control; in rice, the worst weeds are “Echinochloa” and “Cyperus”; in corn and cotton “Abutilon”, “Chenopodium”, “Cyperus”, “Echinochloa” and “Sorghum”; in annual dryland crops weed problems are less focused, being the most worrying weeds annual grasses in wheat and barley, besides “Centaurea”, which is also considered to be a problem in sunflower. Finally, there are weeds of increasing threat like “Abutilon”, “Centaurea”, “Chenopodium” and “Sorghum”

    Transcriptome analysis in blood cells from children reveals potential early biomarkers of metabolic alterations

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    OBJECTIVES: The development of effective strategies to prevent childhood obesity and its comorbidities requires new, reliable early biomarkers. Here, we aimed to identify in peripheral blood cells potential transcript-based biomarkers of unhealthy metabolic profile associated to overweight/obesity in children. METHODS: We performed a whole-genome microarray analysis in blood cells to identify genes differentially expressed between overweight and normal weight children to obtain novel transcript-based biomarkers predictive of metabolic complications. RESULTS: The most significant enriched pathway of differentially expressed genes was related to oxidative phosphorylation, for which most of genes were downregulated in overweight versus normal weight children. Other genes were involved in carbohydrate metabolism/glucose homoeostasis or in lipid metabolism (for example, TCF7L2, ADRB3, LIPE, GIPR), revealing plausible mechanisms according to existing biological knowledge. A set of differentially expressed genes was identified to discriminate in overweight children those with high or low triglyceride levels. CONCLUSIONS: Functional microarray analysis has revealed a set of potential blood-cell transcript-based biomarkers that may be a useful approach for early identification of children with higher predisposition to obesity-related metabolic alterations
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