Convection and dynamo action in B stars

Main-sequence massive stars possess convective cores that likely harbor strong dynamo action. To assess the role of core convection in building magnetic fields within these stars, we employ the 3-D anelastic spherical harmonic (ASH) code to model turbulent dynamics within a 10 solar mass main-sequence (MS) B-type star rotating at 4 times the solar rate. We find that strong (900 kG) magnetic fields arise within the turbulence of the core and penetrate into the stably stratified radiative zone. These fields exhibit complex, time-dependent behavior including reversals in magnetic polarity and shifts between which hemisphere dominates the total magnetic energy.Comment: 2 pages, 1 figure; IAU symposium 271, Astrophysical Dynamics: From Galaxies to Star

NEUROIMÁGENES EN ENFERMEDAD DE PARKINSON: ROL DE LA RESONANCIA MAGNÉTICA, EL SPECT Y EL PET

RESUMENLa enfermedad de Parkinson (EP) es un trastorno neurodegenerativo, caracterizado por la pérdida progresiva de neuronas monoaminérgicas, en especial dopaminérgicas. En las últimas décadas, se han desarrollado diversos biomarcadores para el estudio de los pacientes con EP. Un grupo de estos biomarcadores son las neuroimágenes, como la resonancia magnética cerebral y las imágenes moleculares, en particular, la tomografía por emisión de positrones (PET) y la tomografía por emisión de fotón único (SPECT). Estas técnicas, se han empleado en el diagnóstico temprano de la EP, así como para mejorar el diagnóstico diferencial entre EP y otros parkinsonismos y para monitorizar la progresión de la enfermedad. Con estos fines, se ha utilizado la capacidad de estas técnicas para evaluar la pérdida de la actividad dopaminérgica y de otras vías monoaminérgicas, al igual que la posibilidad de valorar la inflamación y el metabolismo a nivel cerebral. Recientemente, los nuevos criterios para el diagnóstico de la EP reconocen al PET y SPECT como herramientas valiosas en el diagnóstico de esta enfermedad. En este artículo, se analiza la utilidad actual de las técnicas de imagen en pacientes con EP y otros parkinsonismos y sus potenciales aplicaciones futuras.SUMMARYParkinson's disease (PD) is a neurodegenerative disorder characterized by a progressive loss of monoaminergic neurons, particularly dopaminergic cell groups. Biomarkers have been developed in the last decades for the study of PD patients. Neuroimages, including Magnetic Resonance Imaging (MRI), Positron Emission Tomography (PET) and Single Photon Emission Computed Tomography are part of these biomarkers evaluated in PD. These techniques had been used for the early diagnosis of PD, for the differential diagnosis between PD and other parkinsonisms and to monitor the progression of these disorders. The ability of these images to evaluate loss of monoaminergic activity and their capacity to estimate inflammatory and metabolic changes in the brain has been used. Recently the new criteria for diagnosis of PD have incorporated to PET and SPECT as useful tools in the diagnosis of this disorder. In this article, we review the utility of the neuroimages in patients with PD and some of their potential future applications

Dynamo Action in the Solar Convection Zone and Tachocline: Pumping and Organization of Toroidal Fields

We present the first results from three-dimensional spherical shell simulations of magnetic dynamo action realized by turbulent convection penetrating downward into a tachocline of rotational shear. This permits us to assess several dynamical elements believed to be crucial to the operation of the solar global dynamo, variously involving differential rotation resulting from convection, magnetic pumping, and amplification of fields by stretching within the tachocline. The simulations reveal that strong axisymmetric toroidal magnetic fields (about 3000 G in strength) are realized within the lower stable layer, unlike in the convection zone where fluctuating fields are predominant. The toroidal fields in the stable layer possess a striking persistent antisymmetric parity, with fields in the northern hemisphere largely of opposite polarity to those in the southern hemisphere. The associated mean poloidal magnetic fields there have a clear dipolar geometry, but we have not yet observed any distinctive reversals or latitudinal propagation. The presence of these deep magnetic fields appears to stabilize the sense of mean fields produced by vigorous dynamo action in the bulk of the convection zone.Comment: 4 pages, 3 color figures (compressed), in press at ApJ

Common variable immunodeficiency. Epidemiology and clinical manifestations in 69 patients.

La inmunodeficiencia común variable (IDCV) se caracteriza por una alteración en la producción de anticuerpos y una mayor susceptibilidad a infecciones por bacterias extracelulares capsuladas, principalmente del tracto respiratorio. Analizamos las características clínicas de 69 pacientes, evaluados en un período de 10 años en tres centros de la ciudad de Buenos Aires. Al inicio del estudio se encontraban en seguimiento 14 pacientes y al finalizar 60; la mayoría fueron derivados por infecciones o hipogammaglobulinemia, y casi la mitad con diagnóstico establecido de inmunodeficiencia. Sesenta y cinco (94.2%) pacientes presentaron infecciones por gérmenes capsulados, cuatro (6.1%) sepsis y dos tuberculosis. La edad promedio de comienzo de los síntomas infecciosos fue de 18.1 años, la edad promedio al momento del diagnóstico fue de 29.6 años y el retraso diagnóstico de 11.9 años. En 41 (59.4%) pacientes se registró el antecedente de diarreas recurrentes o crónicas. En 22 (31.9%) se diagnosticaron 13 enfermedades autoinmunes, siendo las más frecuentes las hematológicas y el hipotiroidismo. Ocho pacientes tuvieron linfoproliferación policlonal histológica, cuatro (5.8%) como enfermedad granulomatosa de hígado, laringe y piel, y cuatro como neumonía intersticial linfoidea (NIL). Diecinueve (27.5%) pacientes presentaron esplenomegalia y 23/57 (40.3%) imágenes sugestivas de procesos granulomatosos o linfocíticos en la TAC de tórax (incluidos los 4 con NIL). Tres (4.3%) pacientes desarrollaron linfoma B, cuatro (5.8%) adenocarcinoma de estómago y uno cáncer de mama. El estudio tuvo una mediana de seguimiento de 54 meses, rango 1-353 y durante el período del mismo murieron cuatro pacientes (5.8%).Common variable immunodeficiency (CVID) is characterized by an impaired antibody production and an increased susceptibility to recurrent infections of the respiratory tract, mainly by extracellular encapsulated bacteria. We analyzed the clinical characteristics of 69 patients evaluated over a period of 10 years at three centers in the city of Buenos Aires. At the onset of the study 14 patients were on follow up, and at its end the number of patients reached to 60. Most of them consulted for infection or hypogammaglobulinemia and nearly half had an established diagnosis of immunodeficiency. Sixty-five (94.2%) patients had infections by encapsulated bacteria, four (6.1%) sepsis and two tuberculosis. The average age of onset of infectious symptoms was 18.1 years; the average age at diagnosis was 29.6 years and the delay to diagnosis 11.9 years. Forty one (59.4%) patients reported a history of recurrent or chronic diarrhea. In 22 (31.9%) 13 autoimmune diseases were diagnosed, being the most frequent the hematological disorders and hypothyroidism. Eight patients had histological polyclonal lymphoproliferation, four (5.8%) with granulomatous disease affecting the liver, the larynx and/or the skin; and four as lymphoid interstitial pneumonitis (LIP). Nineteen (27.5%) patients had splenomegaly and 23/57 (40.3%) images suggestive of lymphocytic or granulomatous processes (including the 4 with LIP) in the chest CT. Three (4.3%) patients developed B cell lymphoma, four (5.8%) stomach adenocarcinoma and one breast cancer. The study had a median follow-up of 54 months, range 1-353 and four patients (5.8%) died during the follow up.Fil: Fernández Romero, Diego S.. Hospital Britanico. Serv. de Alergia E Inmunologia Clinica; ArgentinaFil: Juri, María C.. Hospital Britanico. Serv. de Alergia E Inmunologia Clinica; ArgentinaFil: Paolini, María V.. Hospital Durand; ArgentinaFil: Malbran, Alejandro. Hospital Britanico. Serv. de Alergia E Inmunologia Clinica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

ON THE GEOMETRY OF THE X-RAY EMITTING REGION IN SEYFERT GALAXIES

For the first time, detailed radiative transfer calculations of Comptonized X-ray and gamma-ray radiation in a hot pair plasma above a cold accretion disk are performed using two independent codes and methods. The simulations include both energy and pair balance as well as reprocessing of the X- and gamma-rays by the cold disk. We study both plane-parallel coronae as well as active dissipation regions having shapes of hemispheres and pill boxes located on the disk surface. It is shown, contrary to earlier claims, that plane-parallel coronae in pair balance have difficulties in selfconsistently reproducing the ranges of 2-20 keV spectral slopes, high energy cutoffs, and compactnesses inferred from observations of type 1 Seyfert galaxies. Instead, the observations are consistent with the X-rays coming from a number of individual active regions located on the surface of the disk. A number of effects such as anisotropic Compton scattering, the reflection hump, feedback to the soft photon source by reprocessing, and an active region in pair equilibrium all conspire to produce the observed ranges of X-ray slopes, high energy cutoffs, and compactnesses. The spread in spectral X-ray slopes can be due to a spread in the properties of the active regions such as their compactnesses and their elevations above the disk surface. Simplified models invoking isotropic Comptonization in spherical clouds are no longer sufficient when interpreting the data.Comment: 9 pages, 3 postscript figures, figures can be obtained from the authors via e-mail: [email protected]

Mapping the invisible chromatin transactions of prophase chromosome remodeling

We have used a combination of chemical genetics, chromatin proteomics, and imaging to map the earliest chromatin transactions during vertebrate cell entry into mitosis. Chicken DT40 CDK1(as) cells undergo synchronous mitotic entry within 15 min following release from a 1NM-PP1-induced arrest in late G(2). In addition to changes in chromatin association with nuclear pores and the nuclear envelope, earliest prophase is dominated by changes in the association of ribonucleoproteins with chromatin, particularly in the nucleolus, where pre-rRNA processing factors leave chromatin significantly before RNA polymerase I. Nuclear envelope barrier function is lost early in prophase, and cytoplasmic proteins begin to accumulate on the chromatin. As a result, outer kinetochore assembly appears complete by nuclear envelope breakdown (NEBD). Most interphase chromatin proteins remain associated with chromatin until NEBD, after which their levels drop sharply. An interactive proteomic map of chromatin transactions during mitotic entry is available as a resource at https://mitoChEP.bio.ed.ac.uk

Evaluation of Taro (Colocasia esculenta L.) Cultivars for Growth, Yield and Quality Attributes

A study on varietal evaluation in taro for growth, yield and quality attributes was carried out in a replicated experiment and morphological and chemical analysis was done. Significant differences were recorded for all the characteristics studied. 'Panchmukhi' recorded highest plant height (179.33cm), petiole length (153.11cm), petiole breadth (13.87mm) and leaf size (3095.67cm2), LAI (1.14), corm length (152.41mm) and breadth (107.77mm), average corm weight (1500.00g) and corm yield (20.00t/ha). 'C-3' recorded maximum (15.00) petiole number and cormel length (85.93mm). Cormel yield (15.29t/ha), total yield (25.92t/ha) and number of cormels per plant (30.33) was found to be maximum in cv. White Gouriya. 'ML-2' recorded maximum (7.33) number of side shoots. Highest average cormel weight (72.85g) was maximum in cv. Arcol-7, and 'Arcol-5' recorded maximum (67.43mm) cormel breadth; the least blight incidence percentage (8.00) was recorded in 'Nayabungalow'. As for biochemical constituents, 'Nainital' recorded the highest (5.85%) total sugars, 'Kandha-5' exhibited the highest (34.67%) starch content and 'Nadia Local' with showed highest levels of oxalic acid (1.05mg/100g). Highest dry matter content (27.50%) was recorded in cvs. KCA-1 and Panchmukhi, while the highest moisture percentage (82.83) was recorded in 'IG Coll-5'

The Effect of Amnion-derived Cellular Cytokine Solution on the Epithelialization of Partial-thickness Donor Site Wounds in Normal and Streptozotocin-induced Diabetic Swine

Objective: The purpose of this study was to determine whether amnion-derived cellular cytokine solution (ACCS) could improve the quality of epithelialization and accelerate closure of dermatome-created partial-thickness wounds in normal and streptozotocin-induced diabetic pigs. Methods: Dermatome-created partial-thickness wounds were sealed with wound chambers in healthy and diabetic pigs and were injected with ACCS. Wound fluid was exchanged daily for total protein concentration, and biopsies were taken on days 6, 8, 10, and 12. Epithelialization, thickness of epidermis, number of epidermal cell layers, and rete ridges were evaluated. Results: The macroscopic appearance of the wounds and speed of healing was similar in all groups at each time point. All wounds were healed by day 6. The epidermis was thicker in the ACCS-treated diabetic wounds than in the controls (140.6 μm vs 82.7 μm on day 12 in diabetic pigs). There were more cell layers (13 vs 7.7) in ACCS-treated diabetic pigs on day 12. The number of rete ridges per 2.5 mm was greater on day 12 in the ACCS-treated diabetic wounds (13 vs 8). There was also a significant increase in the number of rete ridges in ACCS-treated nondiabetic pigs but no difference in epidermal thickness or number of cell layers. Conclusion: In diabetic pigs, we found a significantly thicker epidermis and more cell layers and rete ridges in the ACCS-treated wounds. Healthy pigs showed more rete ridges but no difference in thickness of epidermis or number of cell layers on day 12