981 research outputs found
Genes involved in carotene synthesis and mating in Blakeslea trispora
Mating of Blakeslea trispora and other molds of the order Mucorales requires the interaction of mycelia of opposite sex, (+) and (-), leading to the development of specialized structures and to an enhanced accumulation of beta-carotene. Industry obtains beta-carotene by co-cultivating appropriate strains of Blakeslea (mated cultures). Gene transcription in single and mated cultures was assayed by cDNA-AFLP, a technique to observe the differential expression of subsets of mRNA fragments. Overexpression in mated cultures is about ten times more frequent than underexpression. We obtained and sequenced fragments of 97 candidate genes that appeared to be overexpressed during mating and confirmed four of them by reverse transcription and real-time PCR. Comparisons with gene sequences from other organisms suggest functions in carotene biosynthesis (4 genes), energy metabolism (8), cell wall synthesis (1), transfer of acetyl groups (1), and regulatory processes (10). Sodium acetate inhibited sexual overexpression in about two-thirds of the candidate genes and acted as a signal with broad effects on the metabolism and the morphology of mated cultures. Our work offers new materials for the study of carotene biosynthesis and its regulation and for the improvement of carotene production with Mucorales
Topological challenges in multispectral image segmentation
Land cover classification from remote sensing multispectral images has been traditionallyconducted by using mainly spectral information associated with discrete spatial units (i.e. pixels).Geometric and topological characteristics of the spatial context close to every pixel have been either not fully treated or completely ignored.This article provides a review of the strategies used by a number of researchers in order to include spatial and topological properties in image segmentation.ÂÂÂIt is shown how most of researchers have proposed to perform -previous to classification- a grouping or segmentation of nearby pixels by modeling neighborhood relationships as 4-connected, 8-connected and (a, b) – connected graphs.In this object-oriented approach, however, topological concepts such as neighborhood, contiguity, connectivity and boundary suffer from ambiguity since image elements (pixels) are two-dimensional entities composing a spatially uniform grid cell (i.e. there are not uni-dimensional nor zero-dimensional elements to build boundaries). In order to solve such topological paradoxes, a few proposals have been proposed. This review discusses how the alternative of digital images representation based on Cartesian complexes suggested by Kovalevsky (2008) for image segmentation in computer vision, does not present topological flaws, typical of conventional solutions based on grid cells. However, such a proposal has not been yet applied to multispectral image segmentation in remote sensing. This review is part of the PhD in Engineering research conducted by the first author under guidance of the second one. This review concludes suggesting the need to research on the potential of using Cartesian complexes for multispectral image segmentation
Presynchronization of estrous cycles in dairy cows before ovsynch + CIDR and resynchronization of repeat estrus using the CIDR
Postpartum anestrus is one of the major limitations to achieving acceptable pregnancy rates. The Ovsynch protocol is an excellent tool to improve reproductive efficiency of dairy cows because it can induce estrous cycles in anestrous cows. In the first experiment, administering two PGF2 injections to lactating dairy cows 14 days apart with the second injection given 12 days before the Ovsynch protocol increased (P\u3c0.05) pregnancy rate by 10 percentage points in cycling and noncycling cows. Inserting a progesterone-releasing insert (CIDR) for 7 days during the Ovsynch protocol did not further increase pregnancy rates. In a second experiment, a resynchronization treatment consisting of a used CIDR inserted for 7 days from days 13 to 20 after insemination increased (P\u3c0.05) embryo survival from day 30 to 58 by 11 percentage points but failed to increase overall rate of return to estrus and conception rate at the second AI (first eligible estrus after first AI).; Dairy Day, 2001, Kansas State University, Manhattan, KS, 2001
Sistema de análisis de validez de las declaraciones (protocolo SVA) en un caso de abuso sexuales entre menores. Descripción de criterios y su aplicación
El SVA (Statement Validity Assessment) se aplica con frecuencia para la valoración de la credibilidad del testimonio en
menores vÃctimas de abusos sexuales. Constituye una herram
ienta validada en el ámbito de la psicologÃa forense, pero no está exenta
de subjetividad. El rigor metodológico en la aplicación del protocolo es imprescindible para que las conclusiones obtenidas t
engan
alguna validez en el procedimiento. En un caso de d
enuncia de abusos sexuales entre menores se aportó al procedimiento un informe
psicológico forense que analizaba la credibilidad del testimonio tras aplicar el protocolo SVA. Se discute la metodologÃa apl
icada y la
argumentación del informe, y, por tanto,
la validez de las conclusiones obtenidas en el informe pericial presentadoThe SVA (Statement Validity Assessment) is often applied to the assessment of the credibilit
y of testimony in child
victims of sexual abuse. It is a validated tool in the field of forensic psychology, but is somewhat subjective. The methodol
ogical
rigor in the application of the protocol is essential for the conclusions have any validity in the p
roceeding. In case of a complaint of
sexual abuse among children a forensic psychological report analyzing the credibility of the testimony after applying the SVA
protocol is presented to the court. It discusses the methodology and therefore the validity
of the conclusions of the expert report
submitted
Hydrogen sulfide pathway and skeletal muscle: an introductory review.
The presence of the H2 S pathway in skeletal muscle (SKM) has recently been established. SKM expresses the three constitutive H2 S-generating enzymes in animals and humans, and it actively produces H2 S. The main, recognized molecular targets of H2 S, that is, potassium channels and PDEs, have been evaluated in SKM physiology in order to hypothesize a role for H2 S signalling. SKM dysfunctions, including muscular dystrophy and malignant hyperthermia, have also been evaluated as conditions in which the H2 S and transsulfuration pathways have been suggested to be involved. The intrinsic complexity of the molecular mechanisms involved in excitation-contraction (E-C) coupling together with the scarcity of preclinical models of SKM-related disorders have hampered any advances in the knowledge of SKM function. Here, we have addressed the role of the H2 S pathway in E-C coupling and the relative importance of cystathionine β-synthase, cistathionine γ-lyase and 3-mercaptopyruvate sulfurtransferase in SKM diseases
Espondilolistesis traumática del axis asociada a fractura de odontoides: a propósito de un caso
Se presentan dos casos de espondilolistesis traumática del axis, tipo I de
Effendi, asociadas a fractura de odontoides. En ninguno de los casos fue necesario realizar
tratamiento quirúrgico, consiguiendo la consolidación de ambas fracturas mediante
inmovilización con halo-chaleco.Two new case s of traumatic spondylolisthesis of the axis, Effendi's type
I, associated to fracture of the odontoid process are reported. Surgical treatment wa s
not necessary in any of the cases. Repair of both fractures wa s adrieved by means of
inmovilization with halo-chest orthesis
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