Rare top decay t→cγt \rightarrow c \gamma with flavor changing neutral scalar interactions in two Higgs doublet model

Models beyond the Standard Model with extra scalars have been highly motivated by the recent discovery of a Higgs boson. The Two Higgs Doublet Model Type III considers the most general case for the scalar potential, allowing mixing between neutral CP-even and CP-odd scalar fields. This work presents the results of the study on the $t\rightarrow c\gamma$ decay at one loop level if neutral flavor changing is generated by top-charm-Higgs coupling given by the Yukawa matrix. For instance, a value for the branching ratio $Br(t\rightarrow c\gamma)\sim 10^{-6}$ for $\tan\beta=2.5$ and general neutral Higgs mixing parameters, $1.16\leq\alpha_1\leq1.5$, $-0.48\leq\alpha_2\leq-0.1$. The number of events for the $t\rightarrow c \gamma$ decay with an integrated luminosity of 300 $fb^{-1}$ is estimated as $10\lesssim N_{Eff}\lesssim 100$ for the parameters of the model constrained by experimental data.Comment: 12 pages, 12 figure

On the Radio Polarization Signature of Efficient and Inefficient Particle Acceleration in Supernova Remnant SN 1006

We present a radio polarization study of SN 1006, based on combined VLA and ATCA observations at 20 cm that resulted in sensitive images with an angular resolution of 10 arcsec. The fractional polarization in the two bright radio and X-ray lobes of the SNR is measured to be 0.17, while in the southeastern sector, where the radio and non-thermal X-ray emission are much weaker, the polarization fraction reaches a value of 0.6 +- 0.2, close to the theoretical limit of 0.7. We interpret this result as evidence of a disordered, turbulent magnetic field in the lobes, where particle acceleration is believed to be efficient, and a highly ordered field in the southeast, where the acceleration efficiency has been shown to be very low. Utilizing the frequency coverage of our observations, an average rotation measure of ~12 rad/m2 is determined from the combined data set, which is then used to obtain the intrinsic direction of the magnetic field vectors. While the orientation of magnetic field vectors across the SNR shell appear radial, a large fraction of the magnetic vectors lie parallel to the Galactic Plane. Along the highly polarized southeastern rim, the field is aligned tangent to the shock, and therefore also nearly parallel to the Galactic Plane. These results strongly suggest that the ambient field surrounding SN 1006 is aligned with this direction (i.e., from northeast to southwest) and that the bright lobes are due to a polar cap geometry. Our study establishes that the most efficient particle acceleration and generation of magnetic turbulence in SN 1006 is attained for shocks in which the magnetic field direction and shock normal are quasi-parallel, while inefficient acceleration and little to no generation of magnetic turbulence obtains for the quasi-perpendicular case.Comment: Accepted for publication in Astronomical Journa

Studies on the sulfonylurea herbicide resistance mechanism in Rotala indica Koehne var. uliginosa Koehne

筑波大学University of Tsukuba博士（農学）Doctor of Philosophy in Agricultural Science2001【要旨】thesi

A New Bispectral Test for Nonlinear Serial Dependence

Bispectrum, nonlinearity, time series analysis

Exploratory Study on Selected Philippine Agricultural Commodity Import Statistics vis-Ã -vis Export Statistics of the Exporting Countries

Using the import data compiled by the Philippines and comparing these with data as reported by the exporting countries, this study aims to determine the disparity of the statistics from the two sources on the quantity and value of selected agricultural commodities for the years 2000 to 2005. The products covered by this study consist of wholly or semi-milled rice, maize (corn), live poultry, domestic fowls, ducks, geese, frozen meat of bovine animals, apples, oranges, onions and shallots, and garlic. The differences in statistics on the bilateral transactions─in terms of FOB values, quantities, and derived unit prices─are examined by using percentage differences, the implicit minimal measurement error (IMME), and the Wilcoxon Matched-Pair Signed-Ranks (Wilcoxon-MPSR) test. Results show that considerable discrepancies between import and export statistics do exist. The discrepancy may reflect both legitimate conceptual differences between Philippine imports and exports statistics of the exporting countries, as well as errors in reporting. The discrepancy is further substantiated by the results of the Wilcoxon-MPSR test, which show that these differences are significant.

The symbiotic binary system RX Puppis: a possible recurrent nova with a Mira companion

We present an analysis of photometric and spectroscopic observations of the symbiotic binary system RX Pup with the aims of developing a reliable binary for the system and identifying mechanisms responsible for its spectacular activity. The binary is composed of a long-perod Mira variable surrounded by a thick dust shell and a hot white dwarf companion. The hot component produces practically all activity observed in the UV, optical and radio range, while variable obscuration of the Mira by circumstellar dust is responsible for long-term changes in the near-IR magnitudes. The observations show RX Pup underwent a nova-like eruption during the last three decades. The hot component contracted in radius at roughly constant luminosity from 1975 to 1986, and was the source of a strong stellar wind which prevented it from accreting material lost in the Mira wind. Around 1988/9 the hot component turned over in the HR diagram and by 1991 its luminosity had faded by a factor of about 30 with respect to the maximum plateau value and the hot wind had practically ceased. By 1995 the nova remnant started to accrete material from the Mira wind, as indicated by a general increase in intensity of the optical continuum and HI emission. The quiescent spectrum resembles the quiescent spectra of symbiotic recurrent novae, and its intensity indicates the hot component must accrete as much as about 1 per cent of the Mira wind, which is more or less the amount predicted by Bondi-Hoyle theory. The earliest observational records from the 1890s suggest that another nova-like eruption of RX Pup occurred around 1894.Comment: 23 pages, 12 figues, MNRAS - accepte

Learner Uptake of Teacher Electronic Feedback in ESL Composition

The research on electronic feedback in second language writing is scarce, despite the increasingly frequent use of computers in ESL writing classrooms. The current study's purpose is to determine (1) what types of electronic written feedback ESL learners receive on writing that has been submitted and returned electronically, and (2) the relationship between teacher feedback and uptake. Twelve ESL students and three teachers participated in this longitudinal study. Multiple drafts of two essays from two semesters of college-level first-year composition were analyzed. The findings show that most of the teachers' electronic feedback consisted of marginal comments that were, for the most part, directive, explicit, principled, systematic, and needs-based – much like handwritten feedback. Importantly, electronic feedback was successful at eliciting appropriate revisions of grammatical structures or surface-level features, but also content and organization. This suggests that electronic feedback can be effective and therefore should not be avoided

Representación cartográfica mediante técnicas de SIG de formas del relieve y procesos geomorfológicos activos en el sector de Veguellina de Órbigo (León, noroeste de España)

En el presente trabajo se ha realizado un estudio de las formas del relieve y de procesos geomorfológicos activos en las proximidades de Veguellina de Órbigo (provincia de León). El objetivo es la caracterización detallada del medio físico de la zona de estudio como base para estudios de susceptibilidad de riesgos geológicos y su representación en un mapa geomorfológico y de procesos activos a escala 1:25000. El procedimiento metodológico ha consistido en una primera fase de estudio bibliográfico sobre trabajos previos en la zona. En una segunda fase se ha abordado el análisis geomorfológico del territorio, que se ha realizado combinando técnicas de fotointerpretación estereoscópica, trabajos de campo y con la ayuda de la cartografía base (curvas de nivel, ortofotos y MDT del Instituto Geográfico Nacional), identificando los relieves y los procesos de toda la zona, con su validación sobre el terreno en 28 puntos de observación. En la tercera fase se ha creado una base de datos en ArcGis tanto espacial como de atributos, que ha supuesto la digitalización de las distintas unidades cartográficas diferenciadas en la fase anterior, siguiendo durante el proceso de edición del mapa el método propuesto por el Instituto Geológico y Minero de España (IGME). Como resultados, se han determinado tres grandes unidades geomorfológicas en las que se dan procesos geomorfológicos específicos que se han Mapa Geomorfológico y de Procesos Activos final. Este mapa permite identificar los distintos procesos superficiales que han dado y dan lugar al relieve actual, reconocer las interacciones entre ellos y establecer la evolución del relieve a lo largo del tiempo, sirviendo como base del conocimiento del medio físico para su uso en distintos aspectos relacionados con el Medio Ambiente, como son la planificación territorial y el análisis de riesgos geológicos.Trabajo financiado por la Junta de Castilla y León, proyecto LE311A12-