The stellar correlation function from SDSS - A statistical search for wide binary stars

We study the statistical properties of the wide binary population in the Galaxy field with projected separations larger than 200 AU by constructing the stellar angular two-point correlation function (2PCF) from a homogeneous sample of nearly 670'000 main sequence stars. The selected stars lie within a rectangular region around the Northern Galactic Pole and have apparent r-band magnitudes between 15 and 20.5 mag and spectral classes later than G5 (g-r > 0.5 mag). The data were taken from the Sixth Data Release of the Sloan Digital Sky Survey. We model the 2PCF by means of the Wasserman-Weinberg technique including several assumptions on the distribution of the binaries' orbital parameters, luminosity function, and density distribution in the Galaxy. In particular, we assume that the semi-major axis distribution is described by a single powerlaw. The free model parameters - the local wide binary number density and the power-law index of the semi-major axis distribution - are inferred simultaneously by least-square fitting. We find the separation distribution to follow Oepik's law up to the Galactic tidal limit, without any break and a local density of 5 wide binaries per 1'000 cubic parsec with both components having spectral type later than G5. This implies that about 10% of all stars in the solar neighbourhood are members of such a late-type wide binary system. With a relative statistical (2 sigma) error of about 10%, our findings are in general agreement with previous studies of wide binaries. The data suggest that about 800 very wide pairs with projected separations larger than 0.1 pc exist in our sample, whereas none are found beyond 0.8 pc.Comment: 18 pages, 14 figures, 7 tables; added reference for section

Wide Binary Stars in the Galactic Field - A Statistical Approach

This thesis focuses on the statistical properties of wide binary (WB) star systems in the Galactic field. For the present study we select a homogeneous sample covering about 675 square degrees in the direction of the NGP. It contains nearly 670,000 MS stars with apparent magnitudes between 15 and 20.5 mag and spectral classes later than G5. The data were taken from the SDSS. We construct the two-point correlation function (2PCF) for angular separations between 2 and 30 arcsecs. The resulting clustering signal is modeled by means of the Wasserman-Weinberg technique. We show that the distribution of semi-major axis is consistent with the canonical Oepik law and infer that about 10% of all stars in the solar neighbourhood belong to a WB system. To reduce the noise from optical pairs and to increase the sensitivity of the analysis at larger separations, we include distance information from photometric parallaxes. Introducing a novel weighting procedure based on the binding probability of a double star, we infer the distribution of colours and mass ratios, which were carefully corrected for observational selection effects. About 4,000 WBs were taken into account statistically, whose components have masses between 0.2 and 0.85 solar masses. We find that the WB colour distribution is in accord with the colour distribution of single field stars. However, pairs with a mass difference exceeding 0.5 solar masses seem to be systematically underrepresented as compared to a random pairing of field stars. Our results are broadly in agreement with prior studies but a direct comparison is difficult and often impossible. The novel procedure presented in this thesis can be regarded as complementary to common proper motion studies, and constitutes a viable approach to study the statistical properties of WBs in the Galactic field.Comment: 163 pages, PhD thesi

Interpretation of Precision Measurements in the Strongly Interacting Limit of the Standard Electroweak Model

Strong rescattering corrections to one-loop contributions to the parameters of the standard electroweak model are considered.Comment: 12 page

Short-Term Assessment of Retreating vs. Advancing Microtidal Beaches Based on the Backshore/Foreshore Length Ratio: Examples from the Basilicata Coasts (Southern Italy)

A straightforward conceptual method is proposed to quantitatively assess the seasonal-scale tendency of retreatment or advancement on microtidal beaches by using the backshore/foreshore length ratio. This method is based on measuring the cross-shore profile of a beach when it passes through the “transitional state” that separates the high-from the low-energy season, period during which the morphological characteristics of the beach tend to its equilibrium profile. In order to obtain real measurements of backshore (B) and foreshore (F), the definition of the limits bounding these two important components in subaerial beaches is reviewed and discussed. The approach based on the measurement of the B/F length ratio assumes that foreshore and backshore have equivalent lengths in beaches that approximate to their state of morphodynamic equilibrium (B/F ~ 1). A backshore length exceeding the foreshore length is indicative of a state of beach recession, with a B/F length ratio > 1. When the foreshore length is greater than the backshore length, the shoreline is advancing or, alternatively, it is developing in a state of morphological confinement, i.e. due to the presence of a sea cliff, with a B/F < 1. This practical method is then tested against 36 sand and gravel microtidal beach profiles measured along the coasts of Basilicata, in southern Italy. The various “beach states” are summarised into seven classes (I-VII), each identified from specific value intervals of the B/F length ratio

A facies-based depositional model for ancient and modern, tectonically-confined tidal straits

Modern and ancient tidal straits are the least well understood of all tide-dominated depositional systems. In order to provide an increased understanding of these systems, a facies-based depositional model is assessed by comparing multibeam surveys of three present-day tidally-dominated seaways with a number of superbly exposed Neogene-to-Quaternary strait-fill successions of Calabria (south Italy). The model points out the existence of four depositional zones, laterally-adjacent from the narrowest strait center to its terminations, distributed along symmetrical or asymmetrical seaways. These zones, whose signature is recorded in four facies associations in the Calabrian tidal straits, are: (i) the strait-center zone, associated to the tidal current maxima and where sediments are scarce or absent; (ii) the dune-bedded zone, where sediments form dune complexes due to tidal flow expansion; (iii) the strait-end zone, where currents decelerate accumulating thinly-bedded, fine-grained deposits; (iv) the strait-margin zone, where sediment massflows descend tectonically-active, steep margins towards the strait axis. In ancient, tectonically-confined, narrow seaways, these facies generate a distinctive deepening-upward vertical succession, where tidal currents are the dominant process in the sediment distribution

Relationship between the peroxidation of leukocytes index ratio and the improvement of postprandial metabolic stress by a functional food

For the first time, we investigated the relationship between postprandial dysmetabolism and the Peroxidation of Leukocytes Index Ratio (PLIR), a test that measures the resistance of leukocytes to exogenous oxidative stress and their functional capacity of oxidative burst upon activation. Following a blind, placebo controlled, randomized, crossover design, ten healthy subjects ingested, in two different occasions, a high fat and high carbohydrates meal with Snello cookie (HFHCM-S) or with control cookies (HFHCM-C). Snello cookie, a functional food covered by dark chocolate and containing glucomannan, inulin, fructooligosaccharides, and Bacillus coagulans strain GanedenBC30, significantly improved postprandial metabolic stress (insulin, glucose, and triglycerides) and reduced the postprandial increase of uric acid. HFHCM-S improved PLIR of lymphocytes, but not of monocytes and granulocytes. Both meals increased granulocytes' count and reduced the lipoperoxidation induced by both exogenous free radicals and reactive oxygen species (ROS) produced by oxidative burst. Our results suggest that the healthy status of the subjects could be a limitation of this pilot study for PLIR evaluation on cells that produce ROS by oxidative burst. In conclusion, the relationship between PLIR and postprandial dysmetabolism requires further investigation

Genetic hearing loss: a study of 228 Brazilian patients

We studied 228 patients, with suspected or confirmed genetic hearing loss, in order to determine the clinical and genetic diagnoses and etiology of each case. Deafness with no associated abnormalities was found in 146 patients (64%) belonging to 112 families. Syndromic deafness was diagnosed in 82 patients (36%) belonging to 76 families. The genetic etiology was as follows: autosomal recessive inheritance in 40.8% of syndromics and non-syndromics, autosomal dominant inheritance in 13.2% and X-linked recessive in 1.3%. In 44.7% of the cases, the etiology of the hearing loss could not be determined. Monogenic causes are the most possible etiology in the latter cases. Parental consanguinity was found in 22.4% of the cases, and deafness was bilateral, profound and neurosensorial in 47.4% of the patients. An early onset of hearing loss (< 2 years of age) occurred in 46.5% of the cases. These results are similar to previous literature reports.Estudamos 228 pacientes, pertencentes a 188 famílias, com deficiência auditiva genética, suspeita ou confirmada, já excluídas causas ambientais, no sentido de determinar o diagnóstico clínico e genético e a etiologia em cada caso, já que estudos deste tipo são escassos em pacientes brasileiros. A surdez sem anomalias associadas compreendeu 146 pacientes (64%) pertencentes a 112 famílias. Deficiência auditiva sindrômica foi diagnosticada em 82 pacientes (36%) pertencentes a 76 famílias. Em 44,7% deles, não foi possível determinar a etiologia da deficiência auditiva e a origem monogênica foi suposta baseada em dados de freqüência. Com relação ao padrão de herança, 40,8%, entre sindrômicos e não-sindrômicos, foram recessivos, 13,2% foram dominantes e 1,3%, ligados ao X. Algumas variáveis foram analisadas: consangüinidade parental foi encontrada em 22,4% dos casos, surdez neurosensorial profunda bilateral em 47,4%, e o início precoce da perda auditiva (até 2 anos) em 46,5%. O estudo clínico e a história familiar revelaram-se como os principais métodos para a definição diagnóstica. As causas genéticas de surdez em pacientes brasileiros são similares aos estudos referidos na literatura.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Universidade Federal de São Paulo (UNIFESP) Departamento de Morfologia Disciplina de GenéticaUNIFESP, Depto. de Morfologia Disciplina de GenéticaSciEL

The peroxidation of leukocytes index ratio reveals the prooxidant effect of green tea extract

Despite tea increased plasma nonenzymatic antioxidant capacity, the European Food Safety Administration (EFSA) denied claims related to tea and its protection from oxidative damage. Furthermore, the Supplement Information Expert Committee (DSI EC) expressed some doubts on the safety of green tea extract (GTE). We performed a pilot study in order to evaluate the effect of a single dose of two capsules of a GTE supplement (200mg x 2) on the peroxidation of leukocytes index ratio (PLIR) in relation to uric acid (UA) and ferric reducing antioxidant potential (FRAP), as well as the sample size to reach statistical significance. GTE induced a prooxidant effect on leukocytes, whereas FRAP did not change, in agreement with the EFSA and the DSI EC conclusions. Besides, our results confirm the primary role of UA in the antioxidant defences. The ratio based calculation of the PLIR reduced the sample size to reach statistical significance, compared to the resistance to an exogenous oxidative stress and to the functional capacity of oxidative burst. Therefore, PLIR could be a sensitive marker of redox status

A Global Fit to Extended Oblique Parameters

The STU formalism of Peskin and Takeuchi is an elegant method for encoding the measurable effects of new physics which couples to light fermions dominantly through its effects on electroweak boson propagation. However, this formalism cannot handle the case where the scale of new physics is not much larger than the weak scale. In this case three new parameters (V, W and X) are required. We perform a global fit to precision electroweak data for these six parameters. Our results differ from what is found for just STU. In particular we find that the preference for S < 0 is not maintained.Comment: Plain TeX, 11 pages, one figure (ps file enclosed), (replaced version corrects minor TeX problem, text unchanged) UdeM-LPN-TH-93-166, McGill-93/24, OCIP/C-93-

Constraints on Fermion Magnetic and Electric Moments from LEP-I

The effective Lagrangian approach allows us to constrain fermion magnetic and electric moments using LEP-I data. We improve some of the previous limits on these moments.Comment: LaTex, 15 pages, 12 figures (not included), UAB-FT-31