Search

We study the quark flavor violating Higgs boson decay h→bs+bs in the minimal supersymmetric standard model (MSSM). The decay is analyzed first in a model-independent approach and second in the minimal flavor violating (MFV) constrained MSSM. The experimental constraints from B-physics observables (BPO) and electroweak precision observables (EWPO) are also calculated and imposed on the parameter space. It is shown that, in some cases, the EWPO restrict the flavor violating parameter space more than the BPO. In the model-independent analysis, values of O(10-4) can be found for BR(h→bs+bs). In the MFV constrained MSSM (CMSSM), such results can only be obtained in very restricted parts of the parameter space. The results show that observation of the decay h→bs+bs in the MSSM at future e+e- colliders is not excluded., The work of S. H. and M. R. was partially supported by CICYT (Grant No. FPA 2013-40715-P). M. G., S. H., and M. R. were supported by the Spanish MICINN’s Consolider-Ingenio 2010 Programme under Grant No. MultiDark CSD2009-00064. M. E. G. acknowledges further support from the MICINN Projects No. FPA2011-23781 and No. FPA2014-53631-C2-2-P.

We study the quark flavor violating Higgs-boson decay $h \rightarrow \bar b s + b \bar s$ in the Minimal Supersymmetric Standard Model (MSSM). The decay is analyzed first in a model independent, and in a second step in the minimal flavor violationg (MFV) Constrained MSSM. The experimental constraints from $B$-Physics observables (BPO) and electroweak precision observables (EWPO) are also calculated and imposed on the parameter space. It is shown that in some cases the EWPO restrict the flavor violating parameter space stronger than the BPO. In the model independent analysis values of ${\cal O}(10^{-4})$ can be found for ${\rm BR}(h \rightarrow \bar b s + b \bar s)$. In the MFV CMSSM such results can only be obtained in very restricted parts of the parameter space. The results show that it is not excluded to observe the decay $h \rightarrow \bar b s + b \bar s$ in the MSSM at future $e^+e^-$ colliders., Comment: arXiv admin note: text overlap with arXiv:1501.02258; text overlap with arXiv:hep-ph/9909325 by other authors

Trabajo presentado a la 23rd International Conference on Supersymmetry and Unification of Fundamental Interactions, celebrada en Lake Tahoe, California (US) del 23 al 29 de agosto de 2015., We analyze the effects of (squark and slepton) flavor violation induced by RGE running from the GUT scale within the CMSSM. We show that these effects, in particular in the scalar quark sector, can induce corrections to electroweak precision observables that can set an upper limit on the scalar mass parameter m_0.

Impedance spectroscopy measurements were performed in high quality Vanadium dioxide (VO2) thin films. This technique allows us investigate the resistive and capacitive contribution to the dielectric response near the metal-insulator transition (MIT). A non ideal RC behavior was found in our films from room temperature up to 334 K. A decrease of the total capacitance was found in this region, possibly due to interface effects. Above the MIT, the system behaves like a metal as expected, and a modified equivalent circuit is necessary to describe the impedance data adequately. Around the MIT, an increase of the total capacitance is observed., Comment: 3 pages, 3 figures

Trabajo presentado en el XIV International Congress on Electron Microscopy Photomicrograph Exhibit, celebrado en Cancún (México), del 31 de agosto al 4 de septiembre de 1998, During the vegetative propagation of sugarcane by stem portions, two types of roots are produced. First the roots from the quiescent primordia of the radical band of the nodes, and later the roots of the buds. The life span of the first ones is limited, but the sprouting cane and therefore the development of the plant depends on them. The developing root constitutes a very good system to examine the role of the nucleus and its structural organization in plant cell development. The simple cellular architecture and the clearly definable cell lineages within the root, allow cells of the quiescent primordia to be followed and analyzed throughout all stages of their development. The development of the root primordia from the unsoaked quiescent state of the blastema up to the steady state of the proliferative meristem was analyzed in sugar-cane var. Cristaima, which was cultured on wet filter paper, in an incubator at 30 “C with a 80% humidity, in the dark. The activation of the meristematic population was estimated by the mitotic indexes recorded in squashed roots stained by the Feulgen reaction. The kinetics of the proliferation process was calculated by flow cytometry. For the ultrastructural analysis, the meristematic population was localized in semithin section of roots. During the induction of proliferation hnRNA transcription and RNA splicing activities were investigated by immunolabeling at both fluorescence and electron microscopy. A correlation has been established between nuclear organization and activity, and the signification of some structures typical of quiescent cells, like the nuclear fibrillar bundles, have also been established.

Magnetic measurements were performed on Ferromagnetic/Antiferromagnetic (F/AF) Ca-doped manganite bilayers in order to elucidate the interface contribution to the total magnetic moment. A 10-nm-thick La2/3Ca1/3MnO3 (F) film was used as a ferromagnetic layer and a 60-nm-thick La1/3Ca2/3MnO3 (AF) film as an Antiferromagnetic. The low thickness ratio (1/6) allowed us to enhance the magnetic moment effects due to the AF layer. The temperature dependence of the saturation magnetic moment (MS) was studied. MS was extracted from isothermal magnetic hysteresis loops from room temperature down to 10 K. By using the Heisenberg model frame for the saturation magnetization change, a τ5/2 term was found to better describe the experimental data, meaning long-wavelength spin waves dominate the temperature behaviour. By applying a field cooling field (FC), a significant exchange bias field (Hex) was found (around 20 Oe at 10 K). The Hex temperature dependence follows an exponential decay similar to that observed in the F/AF superlattice case.

The pattern of nucleolar silver staining was determined in the interphase and mitosis of plant cells using two cytological techniques, the selectivity of which was tested densitometrically. For complete accuracy, silver grains were removed and the sections were then observed under uranyl and lead staining. During interphase, the highest density of silver grains occurred in the portions of the dense fibrillar component nearest to the fibrillar centres; the latter were also stained except for the condensed chromatin inclusions typical of the heterogeneous type. During mitosis, not only the nucleolar organiser region (NOR) was stained, but also the prenucleolar material in anaphase and telophase. Two different proteins or sets of proteins are suggested to be responsible for this staining pattern; one of them is associated with NOR chromatin (which is not contained in the mitotic prenucleolar material) and the other with early ribosomal precursors (which have never been found in fibrillar centres). From these two proteins, the “Ag-NOR” reveals either transcriptionally active or potentially active chromatin, characterized by an uncoiled, extended structure, regardless of the state of transcription. This is the structural feature detected by Ag-NOR staining., This work was supported by CSIC Grant No. 41024-10.

The action of 5-Fluorodeoxyuridine (FUdR)used as an inhibitor of RNA synthesis on the nucleolar evolution during mitosis, has been studied in meristematic cells. Under FUdR treatment the nucleolar dispersion appears as a continuous process, but generally it is not completed and nucleolar remnants remain throughout the whole mitosis. The nucleolar material which was dispersed is transported by the mitotic chromosomes, and in telophase contributed to the formation of the new nucleolus. The non-dispersed part persisted in the cytoplasm during telophase, coexisting with both the prenucleolar bodies and the new nucleolus which was being formed. Our results suggest the necessity of some kind of RNA synthesis, preferentially blocked by FUdR, for nucleolar dispersion to take place. © 1978.

In the present work titanium dioxide (TiO2) thin films were grown by d.c. reactive magnetron sputtering process, systematically varying the Ar/O2 ratio in the gas mixture, in order to study the influence of the oxygen partial pressure on the crystallographic structure and photocatalytic activity of the TiO2 thin films. After the sputtering process the TiO2 coatings were nitrided in a microwave (f= 2.45 GHz) Electron Cyclotron Resonance (ECR) plasma discharge in pure nitrogen, to compare the photocatalytic activity of undoped and nitrogen-doped TiO2 thin films. The crystal structure of the TiO2 grown samples was studied by x-ray diffraction (XRD) and the presence of the anatase phase in these films were corroborated by Raman spectroscopy. On the other hand, X-ray photoelectron spectroscopy (XPS) measurements carried out in the nitrogen-doped TiO2 samples, showed that the nitrogen was incorporated to the films with an average concentration of 18 at% of N. The UV-Vis optical spectroscopy allowed calculating the band gap. A narrowing of the optical band gap from 3.2 eV for the undoped films to 2.5 eV for the N-doped films was observed. Photocatalytic activity tests were done using a methylene blue (MB) dye solution. The irradiation of the films in the MB dye solution was carried out with an emission lamp in the UV and in the visible range for undoped and N-doped TiO2 films, respectively. The results showed that the N-doped TiO2 films had a higher photocalytic activity in the visible range, reaching a greater MB degradation in comparison with undoped samples, which were subjected to a higher energy radiation. Fil: Franco Arias, Lina Maria. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad del Valle; Colombia Fil: Zambrano, G.. Universidad del Valle; Colombia Fil: Gómez, M. E.. Universidad del Valle; Colombia Fil: Camps, E.. Instituto Nacional de Investigaciones Nucleares; México Fil: Escobar Alarcón, L.. Instituto Nacional de Investigaciones Nucleares; México

SUMMARY. The aim of the present study was to determine in adolescents the relationship between insulin levels and body mass index (BMI), body fat distribution, diet, life style and lipid profile. We studied 167 adolescents (68 boys and 99 girls) whose ages ranged from 14 to 17 years. A detailed medical (including pubertal stage) and nutritional record was obtained from each subject. Biochemical measurements included fasting serum insulin, glucose, total cholesterol (TC), triglycerides (Tg), HDL-C, LDL-C and VLDL-C. HOMA insulin resistance (IR) and HOMA beta -cell function (beta -cell) were calculated. Insulin levels were over 84 pmol/L (cut off normal value in our lab) in 56% of the boys and 43% of the girls. Thirty-seven percent of lean adolescents whose BMI was 21.5 ± 1.9 kg/m² presented higher fasting insulin levels, HOMA IR, Tg, systolic (SBP) and diastolic blood pressure (DBP) values when compared to a lean normoinsulinemic group. Insulin levels were correlated (p< 0.01) with body mass index. Both boys and girls in the highest BMI quartile (BMI > 24 kg/m²) had significantly higher serum insulin, HOMA beta -cell, and Tg levels, and the lowest HDL-C levels. A high-energy intake rich in saturated fat and low physical activity were found in this lean but metabolically altered adolescents. We conclude that even with a BMI as low as 21 kg/m² an inappropriate diet and low physical activity might be responsible for the high insulin levels and dislipidemias in adolescents. RESUMEN. El objetivo del presente estudio fue determinar la relación entre los niveles de insulina y el Indice de Masa Corporal (IMC), distribución de grasa corporal, dieta, estilo de vida y perfil lipídico en adolescentes. A cada adolescente se la realizó una historia clínica detallada (incluyendo estadío puberal), además de una encuesta nutricional. Dentro de los parámetros bioquímicos se determinaron en suero los niveles de glicemia e insulina basal, colesterol total (CT), triglicéridos (TG), HDL-C, LDL-C, y VLDL-C. Se calcularon el HOMA-IR, y el HOMA-ß-cell. Se encontró que el 56% de los varones y el 43% de las hembras tenía valores de insulina > 84pmol/L (valor de referencia para nuestro laboratorio). Un 37% de los adolescentes delgados, con un IMC promedio de 21,5 ± 1,9 kg/m², presentó niveles elevados de insulina, HOMA-IR, TG, presión arterial sistólica y diastólica comparados con el grupo de adolescentes delgados normoinsulinémicos. Se encontró una correlación positiva y significativa (p< 0,01) entre los niveles de insulina y el IMC. Tanto los varones como las hembras ubicados en los cuartiles más altos de IMC (IMC>24 kg/m² ), tenian niveles significativamente más altos de insulina, HOMA- ßcell y TG, acompañados de niveles más bajos de HDL-C. Una alta ingesta de energía rica en grasa saturadas y una baja actividad física, se encontraron en estos adolescentes delgados pero metabólicamente alterados. En conclusión, niveles tan bajos de IMC como 21 kg/m², una dieta inapropiada y una baja actividad física pueden ser responsables de los altos niveles de insulina y dislipidemias en los adolescentes.

"The aim of this study is to identify the influence of the ligand aminoacidato on the antiproliferative activity against humantumor cell lines HeLa, HCT-15 and SKL-U through the analysis of a set of Cu(II) coordination compounds with general formula [Cu(4,7- dimethyl-1,10-phenanthroline)(N-O)]NO3where N-O represents severalessential aminoacids. Results show that the hydrophobicity of the amino acid ligands increases the cellular uptake of copper (II) in HeLa tumor cell line, however, the increase of copper concentration inside the cell is not enough to produce significant changes in antiproliferative activity in this tumor cell line. Thus, the substituents on diimine ligand apparently play the stronger role to control the activity of these complexes. Also molecular structures of compounds 2 (Cas IIala) and 4 (Cas IInva) are presented."

We studied growth mechanisms in semiconducting Ga1 - xIn xAs ySb1 - y films grown by liquid phase epitaxy on (100) GaSb:Te (10(17) cm- 3) substrates at 600 ºC solution-substrate temperature. Atomic Force Microscopy (AFM) images of these films show step-like corrugations, undulations, grooves, and terraces. The terraces are a few nm in height and hundreds of nanometers in length. Epitaxial Ga1 - xIn xAs ySb1 - y films grow lattice-matched to the (100) GaSb substrates. These narrow-gap quaternary Ga1 - xIn xAs ySb1 - y compounds are suitable materials for heterostructure devices operating in the infrared wavelength range. The estimated x and y values are in the GaSb-rich zone. The step-like corrugations (bunching steps) are formed by different mechanisms, such as pinning effect probably due to impurities on the substrate surface.

Memoria de Tesis Doctoral realizada por Muhammad Rehman y presentada en el Instituto de Física de Cantabria., [ES]: La tesis investiga efectos de mezcla del sabor en modelos Supersimétricos a electro-débil medidos con gran precisión, correcciones a la masa del bosón de Higgs, detalles en el cómputo de la física relacionada con el quark b, desintegraciones del bosón de Higgs con violación de sabor de quark y finalmente, desintegraciones del bosón de Higgs con violación de sabor leptónico. Se han estudiado los efectos de la mezcla de sabor de los s-quarks y s-leptones de una manera independiente del modelo (MI) y tambian se estudiaron los efectos de la mezcla de squarks en el CMSSM y de sleptones en la extensión de éste con un mecanismo “see-saw” de tipo I. En ambos casos se utilizó la hipótesis de violación de sabor mínima (MFV). En el estudio de manera independiente de modelo, el efecto de mezcla de sabor de los s-quarks dentro de los intervalos permitidos experimentalmente implica contribuciones para electro-débil medidos con gran precisión que pueden exceder el margen de error con el que están medidos. En el sector de los bosones de Higgs, la introducción de violación de sabor de los s-leptones implica contribuciones no triviales a las masas del bosón de Higgs. En nuestro estudio de MFV hemos utilizado dos modelos con gran unificación “realistas” en los que la violación de sabor es introducida al tener en cuenta la presencia de las matrices CKM y PMNS en las RGE’s. Se encontró que el desestimar los efectos de violación de sabor es adecuado para los “B-Physics observables” y las masas de los bosons de Higgs. Sin embargo, para los electro-débil medidos con gran precisión se encontraron efectos grandes. Por tanto, los efectos de violación de sabor, objeto de nuestro estudio imponen un nuevo límite a parámetros en CMSSM., [EN]: This dissertation investigates the flavor mixing effects in Supersymmetric models on electroweak precision observables, Higgs boson mass predictions, B-physics observables, quark flavor violating Higgs decays and lepton flavor violating charged lepton decays and lepton flavor violating Higgs decays. We have studied the flavor mixing effects in model independent way. We also studied effects of flavor mixing of squarks in CMSSM and of sleptons in CMSSM with seesaw extension. For the model independent study, we were able to put new constraints on the flavor violating deltas from electroweak precision observables in the case of squarks whereas no new constraints could be set for the case of slepton deltas. In our analysis of minimal flavor violating CMSSM, we found that flavor mixing can have large impact to electroweak precision observables, enabling us to put new constraints on parameter space in CMSSM. However flavor mixing effects to Higgs boson masses and B-Physics observables were found to be negligible., I would like to acknowledge Spanish Government for providing me financial support through the Spanish MICINN’s Consolider-Ingenio 2010 Programme under grant MultiDark CSD2009-00064.