328 research outputs found

    Increased expression of gamma-aminobutyric acid transporter-1 in the forebrain of infant rats with corticotropin-releasing hormone-induced seizures but not in those with hyperthermia-induced seizures.

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    High affinity, gamma-aminobutyric acid (GABA) plasma membrane transporters (GATs) influence the availability of GABA, the main inhibitory neurotransmitter in the brain. Recent studies suggest a crucial role for GATs in maintaining levels of synaptic GABA in normal as well as abnormal (i.e., epileptic) adult brain. However, the role of GATs during development and specifically changes in their expression in response to developmental seizures are unknown. The present study examined GAT-1-immunolabeling in infant rats with two types of developmental seizures, one induced by corticotropin-releasing hormone (CRH) lasting about 2 h and the other by hyperthermia (a model of febrile seizures) lasting only 20 min. The number of GAT-1-immunoreactive (ir) neurons was increased in several forebrain regions 24 h after induction of seizures by CRH as compared to the control group. Increased numbers of detectable GAT-1-ir cell bodies were found in the hippocampal formation including the dentate gyrus and CA1, and in the neocortex, piriform cortex and amygdala. In contrast, hyperthermia-induced seizures did not cause significant changes in the number of detectable GAT-1-ir somata. The increase in GAT-1-ir somata in the CRH model and not in the hyperthermia model may reflect the difference in the duration of seizures. The brain regions where this increase occurs correlate with the occurrence of argyrophyllic neurons in the CRH model

    Resilience and well-being among children of migrant parents in South-East Asia

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    There has been little systematic empirical research on the well-being of children in transnational households in South-East Asia—a major sending region for contract migrants. This study uses survey data collected in 2008 from children aged 9, 10 and 11 and their caregivers in Indonesia, the Philippines, and Vietnam (N=1,498). Results indicate that while children of migrant parents, especially migrant mothers, are less likely to be happy compared to children in non-migrant households, greater resilience in child well-being is associated with longer durations of maternal absence. There is no evidence for a direct parental migration effect on school enjoyment and performance. The analyses highlight the sensitivity of results to the dimension of child well-being measured and who makes the assessment.Publisher PDFPeer reviewe

    Strategy for the inversion of Hinode spectropolarimetric measurements in the quiet Sun

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    In this paper we propose an inversion strategy for the analysis of spectropolarimetric measurements taken by {\em Hinode} in the quiet Sun. The spectropolarimeter of the Solar Optical Telescope aboard {\em Hinode} records the Stokes spectra of the \ion{Fe}{i} line pair at 630.2 nm with unprecendented angular resolution, high spectral resolution, and high sensitivity. We discuss the need to consider a {\em local} stray-light contamination to account for the effects of telescope diffraction. The strategy is applied to observations of a wide quiet Sun area at disk center. Using these data we examine the influence of noise and initial guess models in the inversion results. Our analysis yields the distributions of magnetic field strengths and stray-light factors. They show that quiet Sun internetwork regions consist mainly of hG fields with stray-light contaminations of about 0.8.Comment: To appear in Publications of the Astronomical Society of Japan, 8 pages, 10 figure

    Kinematics of Magnetic Bright Features in the Solar Photosphere

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    Convective flows are known as the prime means of transporting magnetic fields on the solar surface. Thus, small magnetic structures are good tracers of the turbulent flows. We study the migration and dispersal of magnetic bright features (MBFs) in intergranular areas observed at high spatial resolution with Sunrise/IMaX. We describe the flux dispersal of individual MBFs as a diffusion process whose parameters are computed for various areas in the quiet Sun and the vicinity of active regions from seeing-free data. We find that magnetic concentrations are best described as random walkers close to network areas (diffusion index, gamma=1.0), travelers with constant speeds over a supergranule (gamma=1.9-2.0), and decelerating movers in the vicinity of flux emergence and/or within active regions (gamma=1.4-1.5). The three types of regions host MBFs with mean diffusion coefficients of 130 km^2/s, 80-90 km^2/s, and 25-70 km^2/s, respectively. The MBFs in these three types of regions are found to display a distinct kinematic behavior at a confidence level in excess of 95%.Comment: 8 pages, 4 figure

    Solar Coronal Loops Associated with Small-scale Mixed Polarity Surface Magnetic Fields

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    How and where are coronal loops rooted in the solar lower atmosphere? The details of the magnetic environment and its evolution at the footpoints of coronal loops are crucial to understanding the processes of mass and energy supply to the solar corona. To address the above question, we use high-resolution line-of-sight magnetic field data from the Imaging Magnetograph eXperiment instrument on the SUNRISE balloon-borne observatory and coronal observations from the Atmospheric Imaging Assembly onboard the Solar Dynamics Observatory of an emerging active region. We find that the coronal loops are often rooted at the locations with minor small-scale but persistent opposite-polarity magnetic elements very close to the larger dominant polarity. These opposite-polarity small-scale elements continually interact with the dominant polarity underlying the coronal loop through flux cancellation. At these locations we detect small inverse Y-shaped jets in chromospheric Ca II H images obtained from the SUNRISE Filter Imager during the flux cancellation. Our results indicate that magnetic flux cancellation and reconnection at the base of coronal loops due to mixed polarity fields might be a crucial feature for the supply of mass and energy into the corona.Comment: Published in the Astrophysical Journal Supplement Serie

    Magnetic Landscape of Sun's Polar Region

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    We present the magnetic landscape of the polar region of the Sun that is unprecedented in terms of high spatial resolution, large field of view, and polarimetric precision. These observations were carried out with the Solar Optical Telescope aboard \emph{Hinode}. Using a Milne-Eddington inversion, we found many vertically-oriented magnetic flux tubes with field strength as strong as 1 kG that are scattered in latitude between 70-90 degree. They all have the same polarity, consistent with the global polarity of the polar region. The field vectors were observed to diverge from the center of the flux elements, consistent with a view of magnetic fields that expand and fan out with height. The polar region is also covered with ubiquitous horizontal fields. The polar regions are the source of the fast solar wind channelled along unipolar coronal magnetic fields whose photospheric source is evidently rooted in the strong field, vertical patches of flux. We conjecture that vertical flux tubes with large expansion around the photosphere-corona boundary serve as efficient chimneys for Alfven waves that accelerate the solar wind.Comment: Astrophysical Journal in press V1 and V2 are the sam

    High-resolution spectro-polarimetry of a flaring sunspot penumbra

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    We present simultaneous photospheric and chromospheric observations of the trailing sunspot in NOAA 10904 during a weak flare eruption (GOES magnitude B7.8), obtained with the Swedish Solar Telescope (SST) in La Palma, Canary Islands. High-resolution \ion{Ca}{ii} HH images show a typical two-ribbon structure that has been hitherto only known for larger flares, and the flare appears in a confined region that is discernible by a bright border. The underlying photosphere shows a disturbed penumbral structure with intersecting branches of penumbral filaments. High-resolution Doppler- and vector-magnetograms exhibit oppositely directed Evershed flows and magnetic field vectors in the individual penumbral branches, resulting in several regions of magnetic azimuth discontinuity and several islands where the vertical magnetic field is reversed. The discontinuity regions are co-spatial with the locations of the onset of the flare ribbons. From the results, we conclude that the confined flare region is detached from the global magnetic field structure by a separatrix marked by the bright border visible in \ion{Ca}{ii} HH. We further conclude that the islands of reversed vertical field appear because of flux emergence and that the strong magnetic shear appearing in the regions of magnetic azimuth discontinuity triggers the flare.Comment: 20 pages + 1 online Figure for A&

    Genetic Modification Approaches for Parasporins Bacillus thuringiensis Proteins with Anticancer Activity

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    Bacillus thuringiensis (Bt) is a bacterium capable of producing Cry toxins, which are recognized for their bio-controlling actions against insects. However, a few Bt strains encode proteins lacking insecticidal activity but showing cytotoxic activity against different cancer cell lines and low or no cytotoxicity toward normal human cells. A subset of Cry anticancer proteins, termed parasporins (PSs), has recently arisen as a potential alternative for cancer treatment. However, the molecular receptors that allow the binding of PSs to cells and their cytotoxic mechanisms of action have not been well established. Nonetheless, their selective cytotoxic activity against different types of cancer cell lines places PSs as a promising alternative treatment modality. In this review, we provide an overview of the classification, structures, mechanisms of action, and insights obtained from genetic modification approaches for PS proteins

    Relaciones entre el recuento de células somáticas, test de mastitis California, conductividad eléctrica y el diagnóstico de mastitis subclínicas en cabras lecheras

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    En el tambo caprino, las mastitis son un problema sanitario mayor que afecta tanto la productividad como la inocuidad y calidad de los productos. Debido a que el diagnóstico de las mastitis subclínicas plantea problemas para su correcto monitoreo, el objetivo planteado fue analizar las relaciones entre el estado infeccioso de las mamas, los diferentes métodos de diagnóstico como el conteo de células somáticas (CCS), test de mastitis California (CMT) y la conductividad eléctrica (CE) y sus relaciones y posibilidades de aplicación en las condiciones de los tambos caprinos del país. A partir de cabras, mayormente Saanen (71,9%) en ordeño en los períodos sept/2010-mar/2011 y jun/2011-dic/2011, se tomaron mensualmente muestras de leche individuales (n=846) de cada medio mamario. El estado infeccioso de cada muestra se determinó por cultivos bacterioló- gicos dividiéndolo en medios mamarios no infectados (NI), infectados con patógenos menores y patógenos mayores. El CCS se realizó por Fossomatic, y a modo de control por microscopía directa mediante técnicas de Breed clásica y método de Verde metil Y pironina (VMYP). La pruebas de conductividad eléctrica (CE) se realizaron por dispositivo manual y el CMT fue el clásico. Además, con sólo 30 muestras se evaluó un test comercial “PortaSCC goat” para leche caprina. Las relaciones entre variables fueron analizadas por correlación lineal y regresión simple y sus diferencias por Chi cuadrado o análisis de varianza. Se calculó la sensibilidad (S) y la especificidad (E) y los valores predictivos (VP) de las pruebas. Como patógenos menores se aislaron Staphylococcus sp. coagulasa negativo, SCN (n=37) y como patógenos mayores sólo Staphylococcus aureus (n=13). La presencia de patógenos elevó los CCS (P<0001) y los CMT (P<0,0001), pero no la CE (0,09). Las medias de los CCS para NI, SCN y S. aureus fueron respectivamente de 789427±1139886, 1891432±1521385 y 5296615±3806640. La correlación hallada entre el CCS y de la CE con el estado sanitario de los medios mamarios fue respectivamente de r=0,41 (P<0.0001) y de r=0,12 (P<0,03). El CCS tuvo una correlación de r=0,86 (p<0,0001) con el VMYP, de r=0,64 (p<0,0001) con el CMT, de r=0,24 (p<0,0001) con la CE y de 0,47 (p<0,009) con el PortaSCC. El VMYP dio un conteo celular de un 20,8% inferior al Breed. Los CMT 0, T, 1, 2, y 3 se correspondieron a CCS medios respectivos de 326823, 494294, 741670, 1680557 y 3842440. La S y E respectivamente fueron de 70% y 79% para CCS, del 68% y 80% para el CMT y de solo 58% y 60% para la CE. El estudio muestra que tanto el CCS (línea de corte <1000000) como el CMT (0, T, 1) pueden ser usados para monitorear la presencia de mastitis subclínicas, teniendo en cuenta que presentan una E buena y alto VP negativo (98%) para el diagnóstico de ubres sanas y una S aceptable para detectar infecciones (especialmente patógenos mayores), siempre que se tengan en cuenta el diagnóstico bacteriológico, la recurrencia de los diagnósticos y otros factores no infecciosos ligados al aumento del CCS en las cabras.Mastitis in udders is a major health problem, affecting productivity, safety and product quality in the dairy goat. Because the diagnosis of subclinical mastitis is problematic for accurate monitoring, the objective of this study is to evaluate the relationships among the infectious status of half udder and different diagnosis methods: somatic cell count (SCC), California mastitis test (CMT) and electric conductivity (CE) and its diagnostic possibilities in the real dairy goat systems. From milked goats (Saanen, 76%) during Sept/2010-March/2011 and June/2011-Dec/2011 periods, monthly samples (n=846) of milk were taken from each half udder. Udder halves infectious status was assessed by bacteriological cultures and classified in three groups: negative culture (NI), and intrammary infections by minor pathogens and by major pathogens. Chi square, analysis of variance and correlation and regression analysis were carried out to analyse interrelations between variables. Sensitivity (S), specificity (SP) and predictive values (VP) were calculated. Coagulase-negative Staphylococcus sp SCN (n=37), were the minor pathogen and Staphylococcus aureus (n=13), was the only major pathogen isolated. Pathogen increase CCS (P<0001) and CMT (P<0.0001) but not CE (0.09). The average values for CCS of NI, SCN y S. aureus were respectively 789427±1139886, 1891432±1521385 y 5296615±3806640. The correlation obtained between CCS and CE was respectively r=0.41 (P<0.0001) and r=0.12 (P<0,03). The CCS had significative (p<0.0001) correlations of r=0.86 with VMYP, r=0.64 with CMT, r=0.24 with CE and 0.47 with PortaSCC. The VMYP cell counts was 20.8% lesser than Breed counts. CCS averages were for the CMT scores of 326823 (0), 494294 (traces), 741670 (1), 1680557 (2) and 3842440 (3) cells/ml. S and SP were of 70% and 79% for CCS, 68% and 80% for CMT and 58% y 60% for CE respectively. The study shows that both the CCS (cut line <1000000) and CMT (0, T, 1) can be used to monitor the presence of subclinical mastitis, considering that exhibit good high negative VP (98% ) and good SP for the diagnosis of healthy udders and acceptable S for infections (specially major pathogens), provided that the bacteriological diagnosis, recurrence of diagnosis and other no infectious factors associated to elevated CCS are taken into account.EEA SaltaFil: Suarez, Victor Humberto. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Salta; ArgentinaFil: Martinez, Gabriela Marcela. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Salta; ArgentinaFil: Gianre, Vilma Rita. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Calvinho, Luis Fernando. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Rachoski, A. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Salta; ArgentinaFil: Chávez, M. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Salta; ArgentinaFil: Salatin, Antonio Omar. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Salta; ArgentinaFil: Orozco, S. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Salta; ArgentinaFil: Sánchez, V. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Salta; ArgentinaFil: Bertoni, Emiliano Agustí­n. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Salta; Argentin
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