Magnetically Stabilized Nematic Order I: Three-Dimensional Bipartite Optical Lattices

We study magnetically stabilized nematic order for spin-one bosons in optical lattices. We show that the Zeeman field-driven quantum transitions between non-nematic Mott states and quantum spin nematic states in the weak hopping limit are in the universality class of the ferromagnetic XXZ (S=1/2) spin model. We further discuss these transitions as condensation of interacting magnons. The development of O(2) nematic order when external fields are applied corresponds to condensation of magnons, which breaks a U(1) symmetry. Microscopically, this results from a coherent superposition of two non-nematic states at each individual site. Nematic order and spin wave excitations around critical points are studied and critical behaviors are obtained in a dilute gas approximation. We also find that spin singlet states are unstable with respect to quadratic Zeeman effects and Ising nematic order appears in the presence of any finite quadratic Zeeman coupling. All discussions are carried out for states in three dimensional bipartite lattices.Comment: 16 pages, 3 figure

Gestión integral de aceite vegetal usado. Caso de estudio: ciudad de Villa Dolores, provincia de Córdoba (Argentina)

El presente trabajo de investigación está orientado al estudio de la actual gestión de los aceites vegetales usados en la ciudad de Villa Dolores, desde su generación hasta su actual disposición final. Se denomina aceite vegetal usado (AVU) al que se origine a partir de su utilización en las actividades de cocción o preparación mediante fritura total o parcial de alimentos. En una primera etapa se realizó un análisis teórico y de casos testigo a nivel Nacional. Posteriormente se prevé la realización de encuestas a emprendimientos gastronómicos del caso de estudio. El análisis e interrelación de estos datos, teóricos y de campo, permitirá comparar alternativas de gestión, minimizando los impactos ambientales negativos. Los datos recabados brindarán un marco teórico-práctico para proponer alternativas de gestión integral de residuos, permitiendo mejorar el desempeño ambiental. Se prevé la confección de una nueva herramienta de análisis y gestión para la toma de decisiones en relación a este tipo de residuo.Fil: Camperchioli, A. Universidad Nacional de Villa María. Instituto A. P. de Ciencias Básicas y Aplicadas; Argentina.Fil: Wiemer, A.P. Universidad Nacional de Villa María. Instituto A. P. de Ciencias Básicas y Aplicadas; Argentina.Fil: Mateos, L. Universidad Nacional de Villa María. Instituto A. P. de Ciencias Básicas y Aplicadas; Argentina.Ingeniería del Petróleo, Energía y Combustible

Simultaneous Dependence of the Earthquake-Size Distribution on Faulting Style and Depth

We analyze two high-quality Southern Californian earthquake catalogues, one with focal mechanisms, to statistically model and test for dependencies of the earthquake-size distribution, the b values, on both faulting style and depth. In our null hypothesis, b is assumed constant. We then develop and calibrate one model based only on faulting style, another based only on depth dependence and two models that assume a simultaneous dependence on both parameters. We develop a new maximum-likelihood estimator corrected for the degrees of freedom to assess models' performances. Our results show that all models significantly reject the null hypothesis. The best performing is the one that simultaneously takes account of depth and faulting style. Our results suggest that differential stress variations in the Earth's crust systematically influence b values and that this variability should be considered for contemporary seismic hazard studies

Fortification and health: challenges and opportunities.

Fortification is the process of adding nutrients or non-nutrient bioactive components to edible products (e.g., food, food constituents, or supplements). Fortification can be used to correct or prevent widespread nutrient intake shortfalls and associated deficiencies, to balance the total nutrient profile of a diet, to restore nutrients lost in processing, or to appeal to consumers looking to supplement their diet. Food fortification could be considered as a public health strategy to enhance nutrient intakes of a population. Over the past century, fortification has been effective at reducing the risk of nutrient deficiency diseases such as beriberi, goiter, pellagra, and rickets. However, the world today is very different from when fortification emerged in the 1920s. Although early fortification programs were designed to eliminate deficiency diseases, current fortification programs are based on low dietary intakes rather than a diagnosable condition. Moving forward, we must be diligent in our approach to achieving effective and responsible fortification practices and policies, including responsible marketing of fortified products. Fortification must be applied prudently, its effects monitored diligently, and the public informed effectively about its benefits through consumer education efforts. Clear lines of authority for establishing fortification guidelines should be developed and should take into account changing population demographics, changes in the food supply, and advances in technology. This article is a summary of a symposium presented at the ASN Scientific Sessions and Annual Meeting at Experimental Biology 2014 on current issues involving fortification focusing primarily on the United States and Canada and recommendations for the development of responsible fortification practices to ensure their safety and effectiveness

Network of Earthquakes and Recurrences Therein

We quantify the correlation between earthquakes and use the same to distinguish between relevant causally connected earthquakes. Our correlation metric is a variation on the one introduced by Baiesi and Paczuski (2004). A network of earthquakes is constructed, which is time ordered and with links between the more correlated ones. Data pertaining to the California region has been used in the study. Recurrences to earthquakes are identified employing correlation thresholds to demarcate the most meaningful ones in each cluster. The distribution of recurrence lengths and recurrence times are analyzed subsequently to extract information about the complex dynamics. We find that the unimodal feature of recurrence lengths helps to associate typical rupture lengths with different magnitude earthquakes. The out-degree of the network shows a hub structure rooted on the large magnitude earthquakes. In-degree distribution is seen to be dependent on the density of events in the neighborhood. Power laws are also obtained with recurrence time distribution agreeing with the Omori law.Comment: 17 pages, 5 figure

Anatomía vegetativa e histoquímica en Cynanchum bonariense (Apocynaceae)

Fil: Bravi, V. S. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Cátedra de Morfología Vegetal; Argentina.Fil: Cosa, M. T. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Cátedra de Morfología Vegetal; Argentina.Fil: Pacciaroni, A. del V. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Multidisciplinario de Biología Vegetal; Argentina.Fil: Pacciaroni, A. del V. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas; Argentina.Fil: Wiemer, A. P. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Cátedra de Morfología Vegetal; Argentina.Cynanchum bonariense (Decne.) T. Mey es una enredaderanativa que habita en los bordes de caminos, sobre arbustos, árboles bajos y está ampliamente distribuida en la zona centro y norte de Argentina. Presenta abundante látex de color blanco.El objetivo del presente trabajo fue realizarun análisis anatómico comparativo de los órganos vegetativos con especial atención en los laticíferos.Fil: Bravi, V. S. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Cátedra de Morfología Vegetal; Argentina.Fil: Cosa, M. T. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Cátedra de Morfología Vegetal; Argentina.Fil: Pacciaroni, A. del V. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Multidisciplinario de Biología Vegetal; Argentina.Fil: Pacciaroni, A. del V. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas; Argentina.Fil: Wiemer, A. P. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Cátedra de Morfología Vegetal; Argentina.Ciencias de las Plantas, Botánic

The formation of vault-tubes: a dynamic interaction between vaults and vault PARP

Vaults are barrel-shaped cytoplasmic ribonucleoprotein particles that are composed of a major vault protein (MVP), two minor vault proteins [telomerase-associated protein 1 (TEP1), vault poly(ADP-ribose) polymerase (VPARP)] and small untranslated RNA molecules. Not all expressed TEP1 and VPARP in cells is bound to vaults. TEP1 is known to associate with the telomerase complex, whereas VPARP is also present in the nuclear matrix and in cytoplasmic clusters (VPARP-rods). We examined the subcellular localization and the dynamics of the vault complex in a non-small cell lung cancer cell line expressing MVP tagged with green fluorescent protein. Using quantitative fluorescence recovery after photobleaching (FRAP) it was shown that vaults move temperature independently by diffusion. However, incubation at room temperature (21 degrees C) resulted in the formation of distinct tube-like structures in the cytoplasm. Raising the temperature could reverse this process. When the vault-tubes were formed, there were fewer or no VPARP-rods present in the cytoplasm, suggesting an incorporation of the VPARP into the vault-tubes. MVP molecules have to interact with each other via their coiled-coil domain in order to form vault-tubes. Furthermore, the stability of microtubules influenced the efficiency of vault-tube formation at 21 degrees C. The dynamics and structure of the tubes were examined using confocal microscopy. Our data indicate a direct and dynamic relationship between vaults and VPARP, providing further clues to unravel the function of vaults

Expression in hematological malignancies of a glucocorticoid receptor splice variant that augments glucocorticoid receptor-mediated effects in transfected cells

Glucocorticoids play an important role in the treatment of a number of hematological malignancies, such as multiple myeloma. The effects of glucocorticoids are mediated through the glucocorticoid receptor alpha, the abundance of which can be modulated by alternative splicing of the glucocorticoid receptor mRNA. Two splice variants of the glucocorticoid receptor mRNA have been described: glucocorticoid receptor beta, which reportedly has a dominant negative effect on the actions of the glucocorticoid receptor alpha, and glucocorticoid receptor P, of which the effects are unknown. In this study, we have investigated the expression levels of these two splice variants at the mRNA level in multiple myeloma cells and in a number of other hematological tumors. Although the glucocorticoid receptor beta mRNA was, if at all, expressed at very low levels, considerable amounts (up to 50% of the total glucocorticoid receptor mRNA) glucocorticoid receptor P mRNA was present in most hematological malignancies. In transient transfection studies in several cell types and in multiple myeloma cell lines, the glucocorticoid receptor P increased the activity of the glucocorticoid receptor alpha. These results suggest that the relative levels of the glucocorticoid receptor alpha and the glucocorticoid receptor P may play a role in the occurrence of glucocorticoid resistance in tumor cells during the treatment of hematological malignancies with glucocorticoids