BRST Formulation of 4-Monopoles

A supersymmetric gauge invariant action is constructed over any 4-dimensional Riemannian manifold describing Witten's theory of 4-monopoles. The topological supersymmetric algebra closes off-shell. The multiplets include the auxiliary fields and the Wess-Zumino fields in an unusual way, arising naturally from BRST gauge fixing. A new canonical approach over Riemann manifolds is followed, using a Morse function as an euclidean time and taking into account the BRST boundary conditions that come from the BFV formulation. This allows a construction of the effective action starting from gauge principles.Comment: 18 pages, Amste

Evidence of fruit syndromes in the recently diverged wild tomato clade opens new possibilities for the study of fleshy fruit evolution

Societal Impact Statement Fleshy fruits provide humans with many flavorful and nutritious crops. Understanding the diversity of these plants is fundamental to managing agriculture and food security in a changing world. This study surveyed fruit trait variation across species of tomato wild relatives and explored associations among color, size, shape, sugars, and acids. These wild tomato species native to South America can be interbred with the economically important cultivated tomato. Beyond its application to tomatoes, deepening our knowledge of how fruit traits evolve together is valuable to crop improvement efforts aimed at breeding more nutritious and appealing varieties of fruits. Summary Fleshy fruits display a striking diversity of traits, many of which are important for agriculture. The evolutionary drivers of this variation are not well understood, and most studies have relied on variation found in the wild. Few studies have explored this question on a fine-grained scale with a group of recently diverged species while controlling for environmental effects. We developed the tomato clade as a novel system for fruit trait evolution research by presenting the first common garden-based systematic survey of variation and phylogenetic signal in color, nutrition, and morphology traits across all 13 species of tomato wild relatives (Solanum sect. Lycopersicon). We laid the groundwork for further testing of potential evolutionary drivers by assessing patterns of clustering and correlation among disperser-relevant fruit traits as well as historical climate variables. We found evidence of two distinct clusters of associated fruit traits defined by color, sugar type, and malic acid concentration. We also observed correlations between a fruit\u27s external appearance and internal nutrient content that could function as honest signals to dispersers. Analyses of historical climate and soil variables revealed an association between red/orange/yellow fruits and high annual average temperature. Our results establish the tomato clade as a promising system for testing hypotheses on the drivers of divergence behind early-stage fleshy fruit evolution, particularly selective pressure from frugivores

Estudio de propiedades estructurales de películas delgadas de cds depositadas por sublimación en espacio semicerrado

En este trabajo se estudia el efecto de las temperaturas del sustrato y de evaporación, de la distancia entre el evaporador y el sustrato sobre la fase y la orientación cristalográfica de películas delgadas de CdS, preparadas por el método de sublimación en espacio semicerrado (C.S.S.) usando la técnica de difracción de rayos-x.In this work we study the effect of substrate and evaporation temperatures and substrate-evaporator distance on the phase and crystallographic orientation of CdS thin films prepared by the C.S.S. method using the x-ray diffraction technique

Diagnostic tool for radical improvement in business processes

The present work presents a diagnostic tool applicable in any business sector; it works as a support to managers for decision-making towards the need for a radical improvement of processes. A literary review was conducted to collect case studies in order to identify the problems it addresses and the impacts generated by the process of reengineering application in organizations. Through conceptual modeling and synthesization, some diagnostic questions were formulated related to the problems that reengineering has addressed in the literature, and an evaluation model was built that allows organizations to identify what type of problem the organization has, its processes or departments, which should be approached from a radical improvement approach. Finally a diagnostic tool with an evaluation method was formulated, to recommend initiate process improvement either organization, departments o process, formulated fully integrable with PDCA cycle and evaluation or monitoring phases for systems like business activity monitoring based on IT systems, relevant in today's contexts when most of the nowadays organization are technology-based, and progressive improvements do not become a pragmatic and agile alternative in the business context

Non Abelian BF theories with sources and 2-D gravity

We study the interaction of non-Abelian topological $BF$ theories defined on two dimensional manifolds with point sources carrying non-Abelian charges. We identify the most general solution for the field equations on simply and multiply connected two-manifolds. Taking the particular choice of the so-called extended Poincar\'e group as the gauge group we discuss how recent discussions of two dimensional gravity models do fit in this formalism.Comment: 20 pages, Latex, To appear in Phys Rev D5

Determinación de anomalías cromosómicas y secuencias de ADN amplificadas en cáncer de mama

El cáncer de mama en Colombia, es la tercera causa de muerte en la población en general y la segunda en mujeres. En el año 2002 el 40.5% de los casos se presentaron en mujeres menores de 50 años (Pardo, et al. 2003). El cáncer de mama resulta de múltiples factores, entre los que se incluyen cambios sucesivos en el genoma de células epiteliales originalmente normales, que pueden conducir a la activación de oncogenes, inactivación de genes supresores de tumor y pérdida de función de genes reparadores de daños al ADN. Estas alteraciones pueden también ser producto de anomalías cromosómicas tales como monosomías, trisomías, translocaciones, inversiones, pérdida de material genético y amplificaciones que también afectan la expresión de genes (1) (2) (3) (4). Sin embargo, el orden de aparición de los diferentes eventos no está completamente dilucidado. En este estudio se determinaron las anomalías cromosómicas y secuencias de ADN amplificadas en pacientes con cáncer de mama, tanto en muestras de sangre periférica como de tumor de mama de 30 pacientes. En las dos líneas celulares analizadas se observó una alta frecuencia de monosomías principalmente de los cromosomas X, 6, 7, 9, 17, 19 y 22. Hay una asociación entre las monosomías de los cromosomas 17 y 22 con el estado negativo para los receptores de estrógenos y progestágenos (p=0.027, p=0.050). También se encontró asociación entre la monosomía del cromosoma 19 con edad avanzada (p=0.034), observándose formas más agresivas de la enfermedad cuando ésta estuvo presente. Las monosomías fueron características de carcinomas ductales infiltrantes de todos los grados. En los demás tipos de carcinoma su frecuencia fue más baja. En el presente estudio se encontró una asociación significativa entre algunas anomalías cromosómicas y la enfermedad, no reportadas anteriormente, como fueron algunas monosomías, fragilidades y roturas cromosómicas y cromatídicas. La alta frecuencia de fragilidades encontradas tanto en sangre periférica (fra 9q12 p=0.001 y fra 3p14 p= 0.38) como de fragilidades expresadas espontáneamente (no inducidas por el uso de reactivos específicos) en muestras de tumor de mama (fra 1p11 p= 0.001, fra 2q11 p= 0.002), pueden ser el reflejo de una alta inestabilidad cromosómica en el genoma de estos pacientes, mostrando lautilidad de los estudios de fragilidad en la determinación de individuos en alto riesgo de desarrollar cáncer de mama. En ensayos de FISH no se observaron amplificaciones de los genes ERBb2 y c-myc en los pacientes analizados. Esto concuerda con lo encontrado en la literatura en donde se ha reportado, para este tipo de tumores, una sobre expresión de la proteína sin amplificación del gen, explicada por desregulación de la expresión del gen, a su vez posiblemente debida a mutaciones en la región promotora o a alteraciones, que conducen a un aumento de la tasa de transcripción (5) (6) (7). Los resultados obtenidos, aunque preliminares, aportan nuevos marcadores cromosómicos que pueden orientar el diagnóstico, pronóstico y tratamiento de esta patología.Breast cancer is the third cause of death in the general population and the second one in Colombian women. In 2002, 40.5% of the cases were of women younger than 50. Breast cancer originates as a result of multiple and consecutive changes in the genome of normal epithelial cells, such as mutations, oncogene activation, inactivation of tumor suppression genes and of DNA damage repairing genes. The latter, can have its origin in chromosomal abnormalities such as monosomies, trisomies, translocations, inversions, loss of genetic material and amplifications, which may lead to over-expression of oncoproteins related with a greater risk of tumor progression (1) (2) (3) (4). However, very little is known about the sequence in which the different types of alterations of the genome appear. n the present study, the chromosomal abnormalities,and amplified DNA sequences were established in breast cancer patients in both samples of peripheral blood and of tissue from the breast tumor of 30 patients. A high frequency of monosomies, specially those of the chromosomes X, 6, 7, 9, 17, 19 and 22 were observed, with statistically meaningful differences between the monosomies of the chromosomes 17 and 22 and the negative STATE for the estrogen and progesterone receptors (p=0.027, p=0.050) and between the monosomy of the chromosome 19 with an advanced age (p=0.034), indicating more aggressive forms of the disease. The monosomies were characteristic of ductal infiltrating carcinomas of any stage and they were observed in a low frequency in other types of carcinomas. Although relationship between the monosomies, fragilities and BREAKINGS of the chromosome 9 with breast cancer has not been reported by previous studies, these chromosomal abnormalities were found in our study in a representative manner and this finding could constitute a new risk marker in this type of cancer. The high frequency and significance of the fragilities found in peripheral blood and (fra 9q12 p=0.001 y fra 3p14 p= 0.38) those of fragilities spontaneously expressed (not induced by the use of specific REACTIVOS) in breast tumor samples (fra 1p11 p= 0.001, fra 2q11 p= 0.002) may somehow confirm the high chromosomal instability in the genome of these patients, probably allowing these fragility tests to be useful in the early determination of the individuals with a high risk of developing breast cancer. Amplification of the ERBb2 and c-myc genes was not observed in FISH assays in any of the analyzed patients; this agrees with related research, in which an over-expression of the protein without an adequate amplification of the gene has been found in this type of tumors, probably due to mutations in the promoter region and an increase in the transcription rate without there being an amplification of the gene (5) (6) (7). The obtained results, although preliminary, are important due to the fact that they contribute to the search of new chromosomal markers and are also important to the orientation of the diagnosis, prognosis and treatment of this disease

BF models, Duality and Bosonization on higher genus surfaces

The generating functional of two dimensional $BF$ field theories coupled to fermionic fields and conserved currents is computed in the general case when the base manifold is a genus g compact Riemann surface. The lagrangian density $L=dB{\wedge}A$ is written in terms of a globally defined 1-form $A$ and a multi-valued scalar field $B$. Consistency conditions on the periods of $dB$ have to be imposed. It is shown that there exist a non-trivial dependence of the generating functional on the topological restrictions imposed to $B$. In particular if the periods of the $B$ field are constrained to take values $4\pi n$, with $n$ any integer, then the partition function is independent of the chosen spin structure and may be written as a sum over all the spin structures associated to the fermions even when one started with a fixed spin structure. These results are then applied to the functional bosonization of fermionic fields on higher genus surfaces. A bosonized form of the partition function which takes care of the chosen spin structure is obtainedComment: 17 page

Evaluación del efecto tóxico de los extractos vegetales acuosos Barbasco (Phyllantus sp.) Neem (Azadirachta indica) y Marigol (Tagetes patula) sobre los microorganismos Trichoderma sp. y Metarhizium sp.

El experimento se llevó a cabo en el Laboratorio de Fitopatología del Centro de Investigación Natfaima de Corpoica, localizado en el municiplo de El Espinal, departamento del Tolima, entre los meses de marzo y agosto de 2003, Para la piueba se utilizaron extractos vegetales acuosos de Neem (Azadirachía indican), Marigol (Tagetes patula)] y Barbasco [Phylanthus ichihyomelhlus) y los microorganismos biocontroladores Irichoderma sp y Metarhizium so. Bajo condiciones de laboratorio se evaluaron cinco concentraciones (0%. 5%, 10%, 15% y 20%) de cada uno de los tres extractos Gicuosos, frente al crecimiento de los dos microorganismos biocontroladores. Se evaluaron las variables tasa de crecimiento (Crecimiento radial de los hongos biocontraladores) y el valor de la concentración mínima de inhibición. Se ulilizó un diseño completamente al azar y las observaciones se analizaron mediante pruebas de regresión y correlación. En conclusión se puede afirmar que ninguno de los tres extractos en las concentraciones evaluadas, afectan severamente a los hongos Metarhizium so. y Trichoderma sal y que tanto el Neern como el Margo! en concentaciones superiores al 20% puede lener un efecto funguiciaa contra el hongo Trchoaerma so. Igualmente con respecto a Marigel, es posible que en concentraciones más altas, tenga efectos tóxicos sobre el Metarhizlumn sp

A Note on Classical Solution of Chaplygin-gas as D-brane

The classical solution of bosonic d-brane in (d+1,1) space-time is studied. We work with light-cone gauge and reduce the problem into Chaplygin gas problem. The static equation is equivalent to vanishing of extrinsic mean curvature, which is similar to Einstein equation in vacuum. We show that the d-brane problem in this gauge is closely related to Plateau problem, and we give some non-trivial solutions from minimal surfaces. The solutions of d-1,d,d+1 spatial dimensions are obtained from d-dimensional minimal surfaces as solutions of Plateau problem. In addition we discuss on the relation to Hamiltonian-BRST formalism for d-branes.Comment: 20 pages,No figures, Latex, Address change