Work Motivation and Awards Received, and Pupils' Academic Performance in Elementary Schools in the Division of Northern Samar

The article's abstract is no available

Evidence of a massive planet candidate orbiting the young active K5V star BD+20 1790

Original article can be found at: http://www.aanda.org/ Copyright The European Southern Observatory (ESO). DOI: 10.1051/0004-6361/200811000Context. BD+20 1790 is a young active, metal-rich, late-type K5Ve star. We have undertaken a study of stellar activity and kinematics for this star over the past few years. Previous results show a high level of stellar activity, with the presence of prominence-like structures, spots on the surface, and strong flare events, despite the moderate rotational velocity of the star. In addition, radial velocity variations with a semi-amplitude of up to 1 km s-1 were detected. Aims. We investigate the nature of these radial velocity variations, in order to determine whether they are due to stellar activity or the reflex motion of the star induced by a companion. Methods. We have analysed high-resolution echelle spectra by measuring stellar activity indicators and computing radial velocity (RV) and bisector velocity spans. Two-band photometry was also obtained to produce the light curve and determine the photometric period. Results. Based upon the analysis of the bisector velocity span, as well as spectroscopic indices of chromospheric indicators, Ca ii H & K, Hα, and taking the photometric analysis into account, we report that the best explanation for the RV variation is the presence of a substellar companion. The Keplerian fit of the RV data yields a solution for a close-in massive planet with an orbital period of 7.78 days. The presence of the close-in massive planet could also be an interpretation for the high level of stellar activity detected. Since the RV data are not part of a planet search programme, we can consider our results as a serendipitous evidence of a planetary companion. To date, this is the youngest main sequence star for which a planetary candidate has been reported.Peer reviewe

Localization and characterization of phenamil-sensitive Na\u3csup\u3e+\u3c/sup\u3e influx in isolated rainbow trout gill epithelial cells

Percoll density-gradient separation, combined with peanut lectin agglutinin (PNA) binding and magnetic bead separation, was used to separate dispersed fish gill cells into sub-populations. Functional characterization of each of the sub-populations was performed to determine which displayed acid-activated phenamil- and bafilomycin-sensitive Na+ uptake. Analysis of the mechanism(s) of 22Na+ influx was performed in control and acid-activated (addition of 10 mmoll-1 proprionic acid) cells using a variety of Na+ transport inhibitors (ouabain, phenamil, HOE-694 and bumetanide) and a V-type ATPase inhibitor (bafilomycin). We found that cells migrating to a 1.03-1.05 g ml-1 Percoll interface [pavement cells (PVCs)] possessed the lowest rates of Na+ uptake and that influx was unchanged during either bafilomycin (10 nmoll-1) treatment or internal acidification with addition of proprionic acid (10 mmoll-1). Mitochondria-rich (MR) cells that migrated to the 1.05-1.09 g ml-1 interface of the Percoll gradient demonstrated acidification-activated bafilomycin and phenamil-sensitive Na+ influx. Further separation of the MR fraction into PNA+ and PNA- fractions using magnetic separation demonstrated that only the PNA- cells (α-MR cells) demonstrated phenamiland bafilomycin-sensitive acid-activated 22Na+ uptake. We confirm the coupling of a V-type H+-ATPase with phenamil-sensitive Na+ uptake activity and conclude that high-density α-MR cells function in branchial Na+ uptake in freshwater fish

Seawater acclimation causes independent alterations in Na \u3csup\u3e+\u3c/sup\u3e/TK\u3csup\u3e+\u3c/sup\u3e- And H\u3csup\u3e+\u3c/sup\u3e-ATPase activity in isolated mitochondria-rich cell subtypes of the rainbow trout gill

Mitochondria-rich cells (MR cells) of the gills of rainbow trout undergo changes in relative distribution and biochemical function during acclimation to partial-strength (10‰) and full-strength (30‰) seawater. In isolated total gill cells, Na+/K+-ATPase activity increased fivefold and H+-ATPase activity decreased fourfold when trout were acclimated to either 10‰ or 30‰ seawater. When total MR gill cells were separated based on differential binding to peanut lectin agglutinin (PNA), the PNA subtypes underwent a change in relative distribution in seawater-acclimated fish. In freshwater, the ratio of PNA-: PNA+ was 65:35 while in seawater the distribution changed to 20:80 PNA-:PNA+. Additionally, differential changes in Na +/K+-ATPase and H+-ATPase activity in each of the independent cell types occurred during seawater acclimation; Na +/K+-ATPase activity in the PNA- cells increased by 197% while in PNA+ cells Na+TK +-ATPase decreased by 57%. However, H+-ATPase activity was decreased in both PNA- (84%) and PNA+ (72%) subtypes during acclimation to seawater

THE GENOTYPE-ENVIRONMENT INTERACTION IN EXPERI- MENTS OF SUGARCANE VARIETY TRIALS (SACCHARUM SPP.): COMPARISON OF THREE STABILITY METHODS *

ABSTRACT The genotype-environment interaction (g x e) for yield and brix' in eight sugarcane variety trials with 20 genotypes was calculated. The trials were carried out in two localities during three harvest periods. A statistically significant interaction, g x e, in both localities was observed. All data were analyzed by 3 methods in order to determine stability and/or adaptability. The methods were: linear regression, ecovalence method and the coefficient of determination. All the methods used verified in itis' own way the discrimination of genotypes by their stability in relation to environment changes. Finally, the Kendall Coefficient of Correlation was calculated among all stability parameters used verifying positive and significant I correlation between ecovalence and linearity deviation, ecovalence and coefficient of determination, and coefficient of determination and linearity deviation

Intracellular pH regulation in isolated trout gill mitochondrion-rich (MR) cell subtypes: Evidence for Na\u3csup\u3e+\u3c/sup\u3e/H\u3csup\u3e+\u3c/sup\u3e activity

We have studied intracellular pH (pHi) recovery in isolated trout gill mitochondrion-rich (MR) cells following acidification by the NH4Cl pre-pulse technique. Within a mixed MR cell population, one cell type displayed Na+-independent pHi recovery while the other cell type lacked a Na+-independent pHi recovery. Cells displaying Na+ independent recovery exhibited a significantly higher buffering capacity compared to cells lacking Na+-independent pHi recovery. Cells displaying Na+ independent recovery were identified as PNA+ (peanut lectin agluttinin binding) MR cells while those unable to recover were identified as PNA- (non-peanut lectin agluttinin binding) MR cells. Therefore, recovery from acidification in the absence of Na+ provides a direct functional marker for PNA+ and PNA- MR cells. Re-addition of Na+ to acidified cells resulted in a transient pHi recovery in both cell types. This event was abolished by amiloride (500 μM) but it was insensitive to phenamil (50 μM). The phorbol ester PMA (1 μM) potentiated the Na+ induced pHi recovery suggesting that activation by PKC is required for continuous Na+/H+ exchanger activity in trout gill MR cells. This study is the first functional description of pHi recovery in lectin-identified trout gill MR cells and provides insight into a putative cellular signaling mechanism that may control pHi regulation in the gill epithelium. © 2009 Elsevier Inc. All rights reserved

Drivers of predator killing by rural residents and recommendations for fostering coexistence in agricultural landscapes

Predators inhabiting human-dominated landscapes are vulnerable to various anthropogenic actions, including people killing them. We assess potential drivers of predator killing in an agricultural landscape in southern Chile, and discuss the implications for policies and interventions to promote coexistence. We evaluate five different types of motivation: (i) sociodemographics and household economy; (ii) livestock loss; (iii) predator encounter rates; (iv) knowledge of legal protection (all native predators are currently protected); and, (v) tolerance to livestock predation. As the killing of native predators is illegal, the prevalence of this behaviour by rural residents was estimated using a symmetrical forced-response randomised response technique (RRT), a method designed to ask sensitive questions. A total of 233 rural residents from randomly assigned sample units (4 km2) across the study region completed our questionnaire. More conspicuous species, such as hawks (Falconiformes sp), foxes (Lycalopex sp) and free-roaming domestic dogs (Canis lupus familiaris), were killed by a higher proportion of farmers than more cryptic species, like the felid güiña (Leopardus guigna), skunk (Conepatus chinga) and pumas (Puma concolor). The proportion of respondents admitting to killing predators was highest for hawks (mean= 0.46, SE= 0.08), foxes (mean= 0.29, SE= 0.08) and dogs (mean= 0.30, SE= 0.08) and lowest for güiña (mean= 0.10, SE = 0.09), which is the only species of conservation concern we examine (considered Vulnerable on the IUCN Red List). From our five motivation categories, past killing of predators was associated with higher reported predator encounter rates (guina, hawks), lower tolerance to livestock predation (hawks, dogs), higher reported livestock loss (dogs) and sociodemographics and household economy (foxes). Our results demonstrate that a one-size-fits-all approach to predator persecution is unlikely to reduce or eliminate illegal killings for the suite of species we examined. We identify and describe two main types of intervention that could foster coexistence, improvement of livestock management and domestic dog management in rural areas, as well as discussing the potential for social marketing

Dynamical Localization: Hydrogen Atoms in Magnetic and Microwave fields

We show that dynamical localization for excited hydrogen atoms in magnetic and microwave fields takes place at quite low microwave frequency much lower than the Kepler frequency. The estimates of localization length are given for different parameter regimes, showing that the quantum delocalization border drops significantly as compared to the case of zero magnetic field. This opens up broad possibilities for laboratory investigations.Comment: revtex, 11 pages, 3 figures, to appear in Phys. Rev. A, Feb (1997

Modelo analítico para sistema de descarga de calor en techos

En el presente trabajo, se propone un modelo analítico que describe el comportamiento térmico de un sistema de descarga de calor en techo. Para validarlo, se empleó un prototipo experimental al cual se le realizó una prueba con exposición al sol y se comparó los resultados medidos con los calculados por un modelo analítico propuesto por lo autores. Se encontró variaciones de error entre los datos tomados en la prueba experimental y en el modelo analítico de 6.5 ºC como máximo para la placa de aluminio (o almacenadora de calor) y de 4.6 ºC como máximo para la temperatura en la superficie del vidrio. Se considera que el modelo analítico propuesto puede ser empleado para conocer el comportamiento de un sistema de descarga de calor en techos definiendo las dimensiones del sistema para las condiciones ambientales del lugar donde se va a utilizar.Fil: Hernández G., Víctor. Universidad Nacional Autónoma de México; MéxicoFil: Fernández Z., José. Universidad Nacional Autónoma de México; MéxicoFil: Morillón Galvez, David. Universidad Nacional Autónoma de México; MéxicoFil: Mesa, Nestor Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Ciencias Humanas, Sociales y Ambientales; Argentin

Stable Mode Sorting by Two-Dimensional Parity of Photonic Transverse Spatial States

We describe a mode sorter for two-dimensional parity of transverse spatial states of light based on an out-of-plane Sagnac interferometer. Both Hermite-Gauss (HG) and Laguerre-Gauss (LG) modes can be guided into one of two output ports according to the two-dimensional parity of the mode in question. Our interferometer sorts HG_nm input modes depending upon whether they have even or odd order n+m; it equivalently sorts LG modes depending upon whether they have an even or odd value of their orbital angular momentum. It functions efficiently at the single-photon level, and therefore can be used to sort single-photon states. Due to the inherent phase stability of this type of interferometer as compared to those of the Mach-Zehnder type, it provides a promising tool for the manipulation and filtering of higher order transverse spatial modes for the purposes of quantum information processing. For example, several similar Sagnacs cascaded together may allow, for the first time, a stable measurement of the orbital angular momentum of a true single-photon state. Furthermore, as an alternative to well-known holographic techniques, one can use the Sagnac in conjunction with a multi-mode fiber as a spatial mode filter, which can be used to produce spatial-mode entangled Bell states and heralded single photons in arbitrary first-order (n+m=1) spatial states, covering the entire Poincare sphere of first-order transverse modes.Comment: 11 pages, 12 figures, 2 appendice