Fundamental parameters of Cepheids. V. Additional photometry and radial velocity for southern Cepheids

I present photometric and radial velocity data for Galactic Cepheids, most of them being in the southern hemisphere. There are 1250 Geneva 7-color photometric measurements for 62 Cepheids, the average uncertainty per measurement is better than 0.01 mag. A total of 832 velocity measurements have been obtained with the CORAVEL radial velocity spectrograph for 46 Cepheids. The average accuracy of the radial velocity data is 0.38 km/s. There are 33 stars with both photometry and radial velocity data. I discuss the possible binarity or period change that these new data reveal. I also present reddenings for all Cepheids with photometry. The data are available electronically.Comment: To appear in ApJS. Data available electronically at ftp://cfa-ftp.harvard.edu/pub/dbersier

Aceite de linaza: Caracterización y estudio de su degradación oxidativa

This paper proposes to characterize and monitor the degradation of linseed oil under two oxidation conditions using some traditional oxidative and quality parameters. The experimental section of this study was divided into 2 stages. In the first one, three commercial linseed oil samples (OL1, OL2, and OL3) were characterized according to oxidative stability (90 °C) and fatty acid composition. In the second stage, the OL1 sample, selected due to its availability, was subjected to the following oxidation procedures: storage at room temperature conditions with exposure to light and air (temperature ranging from 7 to 35 °C) for 140 days and accelerated oxidation at 100 °C for 7h. Samples were collected at different time intervals and analyzed for oxidative stability (90 °C), peroxide value, and acid value. The results showed that all the samples presented a similar fatty acid profile and that the OL3 sample showed a higher induction period (p < 0.05). Regarding the oxidative degradation, the induction period of the OL1 sample reduced from 9.7 to 5.7 and 9.7 to 6.3 during 140 days of storage under room temperature and 7 h of accelerated oxidation, respectively. The end of induction period of the OL1 sample is expected to occur within 229 days according to an exponential mathematical model fitted to the induction period values at different temperatures. In addition, the OL1 sample met the limits proposed by Codex and Brazilian regulations for peroxide and acid values during the oxidation time intervals.Este trabajo propone caracterizar y monitorear la degradación del aceite de linaza en dos condiciones de oxidación utilizando algunos parámetros oxidativos y de calidad tradicionales. La sección experimental de este estudio se dividió en 2 etapas. En la primera, se caracterizaron tres muestras comerciales de aceite de linaza (OL1, OL2 y OL3) a través de la estabilidad oxidativa (90 °C) y la composición de ácidos grasos. En la segunda etapa, la muestra OL1 se seleccionó por su disponibilidad y se sometió a los siguientes procedimientos de oxidación: almacenamiento en condiciones ambientales con exposición a la luz y al aire (temperatura que varía de 7 a 35 °C) durante 140 días y oxidación acelerada a 100 °C durante 7 h. Las muestras se recogieron a diferentes intervalos de tiempo y se analizaron mediante estabilidad oxidativa (90 °C), índice de peróxido e índice de acidez. Los resultados mostraron que todas las muestras presentaron un perfil de ácidos grasos similar y también que la muestra OL3 mostró un período de inducción más alto (

Understanding the Effects of Training on Underwater Undulatory Swimming Performance and Kinematics

In swimming, the underwater phase after the start and turn comprises gliding and dolphin kicking, with the latter also known as underwater undulatory swimming (UUS). Swimming performance is highly dependent on the underwater phase; therefore, understanding the training effects in UUS and underwater gliding can be critical for swimmers and coaches. Further, the development of technique in young swimmers can lead to exponential benefits in an athlete’s career. This study aimed to evaluate the effects of a training protocol on UUS and underwater gliding performance and kinematics in young swimmers. Seventeen age group swimmers (boys = 10, girls = 7) performed maximal UUS and underwater gliding efforts before and after a seven-week training protocol. Time to reach 10 m; intra-cyclic mean, peak, and minimum velocities; and gliding performance improved significantly after the training protocol. The UUS performance improvement was mostly produced by an improvement of the upbeat execution, together with a likely reduction of swimmers’ hydrodynamic drag. Despite the changes in UUS and gliding, performance was also likely influenced by growth. The findings from this study highlight kinematic variables that can be used to understand and quantify changes in UUS and gliding performance

Chemical Characterization of Major and Minor Compounds of Nut Oils: Almond, Hazelnut, and Pecan Nut

The aim of this work was to characterize the major and minor compounds of laboratory-extracted and commercial oils from sweet almond, hazelnut, and pecan nut. Oils from sweet almond, hazelnut, and pecan nut were obtained by means of an expeller system, while the corresponding commercial oils were provided from Vital Âtman (BR). The contents of triacylglycerols, fatty acids, aliphatic and terpenic alcohols, desmethyl-, methyl-, and dimethylsterols, squalene, and tocopherols were determined. Oleic, palmitic, and linoleic acids were the main fatty acids. Desmethylsterols were the principal minor compounds with β-sitosterol being the most abundant component. Low amounts of aliphatic and terpenic alcohols were also found. The major tocopherol in hazelnut and sweet almond oils was α-tocopherol, whereas γ-tocopherol prevailed in pecan nut oil. Principal component analysis made it possible for us to differentiate among samples, as well as to distinguish between commercial and laboratory-extracted oils. Heatmap highlighted the main variables featuring each sample. Globally, these results have brought a new approach on nut oil characterization

Collusion through Joint R&D: An Empirical Assessment

This paper tests whether upstream R&D cooperation leads to downstream collusion. We consider an oligopolistic setting where firms enter in research joint ventures (RJVs) to lower production costs or coordinate on collusion in the product market. We show that a sufficient condition for identifying collusive behavior is a decline in the market share of RJV-participating firms, which is also necessary and sufficient for a decrease in consumer welfare. Using information from the US National Cooperation Research Act, we estimate a market share equation correcting for the endogeneity of RJV participation and R&D expenditures. We find robust evidence that large networks between direct competitors – created through firms being members in several RJVs at the same time – are conducive to collusive outcomes in the product market which reduce consumer welfare. By contrast, RJVs among non-competitors are efficiency enhancing

Levels of copper, zinc, manganese and iron in two fish species from salt marshes of Cadiz Bay (southwest Iberian Peninsula)

The authors analysed copper, iron, manganese and zinc concentrations in liver, gills and muscle in two species of fish from salt marshes on Cadiz Bay: the sole Solea senegalensis (Kaup, 1858) and the killifish Fundulus heteroclitus (Linnaeus, 1758). The highest concentrations of copper and iron, in both species, were found in the liver. The mean values reported were: 977.71 ± 42.92 and 354.42 ± 22.80 μg g⁻¹ for iron and 124.16 ± 15.97 and 60.17 ± 1.95 μg g⁻¹ dry weight for Cu in S. senegalensis and F. heteroclitus, respectively. The distribution pattern of zinc in organs was different in both fish, so S. senegalensis showed the highest values in liver and F. heteroclitus in gills. The results of the present study enabled us to determine the background concentrations of these metals in both species and their distribution in the different organs. These data will constitute a reference for future studies on the evolution of contamination in this area.Se han analizado las concentraciones de los metales cobre, hierro, manganeso y zinc en branquias, músculos e hígado en ejemplares de dos especies de peces: Solea senegalensis (Kaup, 1858) y Fundulus heteroclitus (Linnaeus, 1758) recolectados en las marismas de la bahía de Cádiz (suroeste de la península Ibérica). Las concentraciones más elevadas para hierro y cobre, en ambas especies, se encontraron en el hígado. Los valores medios registrados fueron: 977,71 ± 42,92 y 354,42 ± 22,80 μg g⁻¹ en el caso del Fe, y 124,16 ± 15,97 y 60,17 ± 1,95 μg g⁻¹ peso seco para el Cu en S. senegalensis y F. heteroclitus, respectivamente. El comportamiento del zinc fue diferente en ambas especies, ya que mientras en S. senegalensis el hígado registró los valores más elevados, en F. heteroclitus éstos se hallaron en branquias. Los resultados obtenidos permiten determinar la concentración basal de estos metales en estas especies y su distribución en los órganos analizados, y constituyen una referencia en estudios posteriores de la evolución de la contaminación en esta zona.Instituto Español de Oceanografí

\pi\pi, K\pi and \pi N potential scattering and a prediction of a narrow \sigma meson resonance

Low energy scattering and bound state properties of the \pi N, \pi\pi and K\pi systems are studied as coupled channel problems using inversion potentials of phase shift data. In a first step we apply the potential model to explain recent measurements of pionic hydrogen shift and width. Secondly, predictions of the model for pionium lifetime and shift confirm a well known and widely used effective range expression. Thirdly, as extension of this confirmation, we predict an unexpected medium effect of the pionium lifetime which shortens by several orders of magnitude. The \sigma meson shows a narrow resonance structure as a function of the medium modified mass with the implication of being essentially energy independent. Similarly, we see this medium resonance effect realized for the K\pi system. To support our findings we present also results for the \rho meson and the \Delta(1232) resonance.Comment: 42 pages, 17 PS figures, REFTeX, epsfig.sty needed, submitted to Phys. Re

Nonlinear electrodynamics and CMB polarization

Recently WMAP and BOOMERanG experiments have set stringent constraints on the polarization angle of photons propagating in an expanding universe: $\Delta \alpha = (-2.4 \pm 1.9)^\circ$. The polarization of the Cosmic Microwave Background radiation (CMB) is reviewed in the context of nonlinear electrodynamics (NLED). We compute the polarization angle of photons propagating in a cosmological background with planar symmetry. For this purpose, we use the Pagels-Tomboulis (PT) Lagrangian density describing NLED, which has the form $L\sim (X/\Lambda^4)^{\delta - 1}\; X$, where $X=1/4 F_{\alpha\beta} F^{\alpha \beta}$, and $\delta$ the parameter featuring the non-Maxwellian character of the PT nonlinear description of the electromagnetic interaction. After looking at the polarization components in the plane orthogonal to the ($x$)-direction of propagation of the CMB photons, the polarization angle is defined in terms of the eccentricity of the universe, a geometrical property whose evolution on cosmic time (from the last scattering surface to the present) is constrained by the strength of magnetic fields over extragalactic distances.Comment: 17 pages, 2 figures, minor changes, references adde