Single production of leptoquarks at the Fermilab Tevatron

We study single production of first generation leptoquarks in association with e± at the Fermilab Tevatron. We focus our attention on final states exhibiting an e+e- pair and jets, and perform a detailed analysis of the signal and background. The single leptoquark production cross section depends on the leptoquark Yukawa coupling to lepton-quark pairs and we show that the study of this mode can extend considerably the leptoquark search for a large range of these couplings. In fact, for Yukawa couplings of electromagnetic strength, the combined results of the Tevatron experiments can exclude the existence of leptoquarks with masses up to 260-285 (370-425) GeV at the run I (run II), depending on their type. ©2000 The American Physical Society.

TL, EPR and optical absorption studies on natural alexandrite compared to natural chrysoberyl

The TL, optical absorption (OA) and EPR properties of natural Brazilian alexandrite and chrysoberyl have been investigated. The TL measurements for natural alexandrite show five peaks between 100 and 450°C, with their emission spectrum having 370 and/or 570 nm components. The intensity of the 320°C TL peak was found to be enhanced with pre-annealing treatment, more prominently above 600°C. The OA and EPR measurements showed that this kind of heat treatment induces the Fe2→ Fe3+ conversion in the natural sample. Chrysoberyl samples exhibited the TL peaks at the same temperatures as alexandrite samples, but the glow curves were more than 200 times less intense than alexandrite ones.

Performance of 19-year-old provenances of Liquidambar styraciflua in Paraguaçu Paulista, São Paulo

The genetic variation in the growth of seven 19-year-old Liquidambar styraciflua provenances was studied in Paraguaçu Paulista, São Paulo State, Brazil. The trial was established in a complete randomized block design with seven provenances, four replications and twelve-tree square plots. Significant differences among provenances were detected for diameter at breast height, height and volume, indicating the possibility of increasing timber yield through selection of the most productive provenances. Genetic correlations between growth traits were high and statistically significant. The provenance from Finca las Victorias, Guatemala had the best and the provenance from Franklin, Virginia, United States the poorest performance for all traits. A growth comparison of Pinus caribaea var. bahamensis with the best provenance at the same site indicated that the potential of L. styraciflua for silviculture in the region of Paraguaçu Paulista is high.

Dielectric tunability in (1-x)[Pb(Mg 1/3Nb 2/3)O 3]-xPbTiO 3 ceramics for tunable devices application

The dielectric properties of the 0.65[Pb(Mg 1/3Nb 2/3)O 3]-0.35PbTiO 3 ferroelectric ceramic composition were investigated viewing the capability to be used for tunable microwave applications. The dielectric response has been studied for three selected temperatures (300 K, 370 K and 400 K), below the paraelectric- ferroelectric phase transition temperature, as a function of the applied 'bias' electric field. The obtained dielectric tunability was found to be around 60 %, under an electric field of 19 kV/cm, which makes the studied ceramic composition an excellent candidate for application in the electro-electronic industry, as tunable devices. © 2010 IEEE.

Locus no cromossomo 19 influencia positivamente o número de oócitos recuperados em ciclos estimulados

Objective: To evaluate if identified loci associated with normal age of menopause variation and early menopause can account for the poor response to controlled ovarian stimulation. Methods: A total of 71 patients, with age ≤ 35 years old, undergoing intracytoplasmic sperm injection were tested for three of the four newly identified genetic variants associated with normal variation in menopausal age and early menopause. Patients were divided into two groups: poor responder group (PR group, n=21) and normoresponder group (NR group, n=50). The influence of risk allele frequency on the response to controlled ovarian stimulation (COS) was evaluated. Logistic regression models were used. Results: There was no significant difference in the incidence of the genetic variants between NR and PR group. The risk allele for chromosome 19 variant (rs4806660) demonstrated a protective effect. The presence of a risk allele, either in homozygosis or in heterozygosis, was associated with an increased response to COS, resulting in an elevated number of follicles (Coef: 2.54, P= 0.041) and retrieved oocytes (Coef: 1.41, P= 0.041). Conclusions: Genetic variants rs244715, rs9379896 and rs4806660 are not risk factors for poor ovarian response. Instead, rs4806660 is associated with higher number of follicles and retrieved oocytes. It could be hypothesized that rs4806660 is associated with an increased response to gonadotrophin stimulus. © Todos os direitos reservados a SBRA - Sociedade Brasileira de Reprodução Assistida.

Perfilhamento do trigo em função da aplicação de regulador vegetal

Tillers survival and yield potential are genetically determined and strongly influenced by environmental conditions during the emission and establishment stage. This experiment was carried in order to study effects of application of growth regulator (Ax+GA+CK) on tiller survival and yield potential of wheat. The experiment was carried out from March to July 2010. A 2 × 2 factorial randomized block design with five replications was used. Two wheat cultivars (IAC 370 and IAC 375) and application or not of Ax+GA+CK at the beginning of tillering stage were evaluated. Tiller emission were evaluated at five ages (19, 26, 33, 40 e 47 days after emergence) and yield components were determined by each individual structure evaluation, comparing to the main stem. Growth regulator application improved the tiller survival when emitted in the first week after application. Tiller yield potential decreased in late emission periods of tillers in both cultivars tested, influenced by different traits of each cultivar. IAC 370 showed higher tiller emission, however, the number of viable tillers were higher for the IAC 375.

Adsorção do corante reativo azul 19 em solução aquosa por lama vermelha tratada quimicamente com peró:xido de hidrogênio

Adsorption of Reactive Blue 19 dye onto activated red mud was investigated. Red mud was treated with hydrogen peroxide (LVQ) and heated at both 400 °C (LVQ400) and 500 °C (LVQ500). These samples were characterized by pH, specific surface area, point of zero charge and mineralogical composition. Adsorption was found to be significantly dependent on solution pH, with acidic conditions proving to be the most favorable. The adsorption followed pseudo-second-order kinetics. The Langmuir isotherm was the most appropriate to describe the phenomenon of dye removal using LVQ, LVQ400 and LVQ500, with maximum adsorption capacity of 384.62, 357.14 and 454.54 mg g-1, respectively.