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Papers by LAURA HERNANDEZ
Journal of The Science of Food and Agriculture, 2005
Resistant starches were prepared from mango starch by extrusion. An experimental design with inde... more Resistant starches were prepared from mango starch by extrusion. An experimental design with independent variables temperature, screw speed and moisture content produced 20 samples that were studied to determine the effect of these variables on resistant starch (RS) content, water absorption index (WAI) and water solubility index (WSI). RS content was affected by moisture content and temperature. Screw speed and temperature also influenced RS content, the highest level (97 g kg−1) being obtained at low screw speed and high temperature, this pattern can be associated with a longer residence time, which gives rise to more opportunity for amylose chain association. The regression model fitted to the RS experimental results showed a good correlation coefficient (0.80). When moisture content and temperature decreased, WAI increased (105–142 g kg−1), but low WAI values (70–77 g kg−1) were obtained at moisture contents between 200 and 300 g kg−1 and high temperatures (140–150 °C). When moisture content and temperature increased, WSI increased (222–332 g kg−1), but at high temperature value (120 °C) assayed and the lowest moisture content (150 g kg−1), WSI also increased. In the range of moisture contents tested and at low temperatures, only partial gelatinisation occurred and low solubility was obtained. Copyright © 2005 Society of Chemical Industry
Journal of Agricultural and Food Chemistry, 1999
Two varieties of banana green fruit growing in Guerrero, Mexico, were used for starch isolation. ... more Two varieties of banana green fruit growing in Guerrero, Mexico, were used for starch isolation. Chemical analysis and physicochemical and functional properties were studied in these starches. The "macho" variety presented higher starch yield than "criollo". In general, chemical compositions in both starches were similar, except in ash content, where the "criollo" variety showed a lower value than "macho". The results of freeze-thaw stability suggested that banana starches cannot be used in frozen products. Both starches presented similar water retention capacity values that increased when temperature increased. Solubility profiles showed that at low temperature "criollo" had lower solubility than "macho", but at higher temperature an inverse behavior was evident; also the solubility increased when temperature increased. Behavior similar to that for solubility was obtained in the swelling test. The banana starch studies indicate the "macho" and "criollo" varieties have different starch structures as evidenced by viscosity.
Applied Soil Ecology, 2008
Biomarker Behaviour Earthworm a b s t r a c t
Developmental Biology, 2005
Specification of both neural crest cells and Rohon-Beard (RB) sensory neurons involves a complex ... more Specification of both neural crest cells and Rohon-Beard (RB) sensory neurons involves a complex series of interactions between the neural and non-neural ectoderm. The molecular mechanisms directing this process are not well understood. The zebrafish narrowminded (nrd) mutation is unique, since it is one of two mutations in which defects are observed in both cell populations: it leads to a complete absence of RB neurons and a reduction in neural crest cells and their derivatives. Here, we show that nrd is a mutation in prdm1, a SET/zincfinger domain transcription factor. A Morpholino-mediated depletion of prdm1 phenocopies the nrd mutation, and conversely overexpression of prdm1 mRNA rescues the nrd RB sensory neuron and neural crest phenotype. prdm1 is expressed at the border of the neural plate within the domain where neural crest cells and RB sensory neurons form. Analysis of prdm1 function by overexpression indicates that prdm1 functions to promote the cell fate specification of both neural crest cells and RB sensory neurons, most likely as a downstream effector of the BMP signaling pathway. D
Developmental Biology, 2004
B1-type SOXs (SOXs 1, 2, and 3) are the most evolutionarily conserved subgroup of the SOX transcr... more B1-type SOXs (SOXs 1, 2, and 3) are the most evolutionarily conserved subgroup of the SOX transcription factor family. To study their maternal functions, we used the affinity-purified antibody antiSOX3c, which inhibits the binding of Xenopus SOX3 to target DNA sequences [Development. 130(2003)5609]. The antibody also cross-reacts with zebrafish embryos. When injected into fertilized Xenopus or zebrafish eggs, antiSOX3c caused a profound gastrulation defect; this defect could be rescued by the injection of RNA encoding SOX3DC-EnR, a SOX3-engrailed repression domain chimera. In antiSOX3c-injected Xenopus embryos, normal animal -vegetal patterning of mesodermal and endodermal markers was disrupted, expression domains were shifted toward the animal pole, and the levels of the endodermal markers SOX17 and endodermin increased. In Xenopus, SOX3 acts as a negative regulator of Xnr5, which encodes a nodal-related TGFh-family protein. Two nodal-related proteins are expressed in the early zebrafish embryo, squint and cyclops; antiSOX3c-injection leads to an increase in the level of cyclops expression. In both Xenopus and zebrafish, the antiSOX3c phenotype was rescued by the injection of RNA encoding the nodal inhibitor Cerberus-short (CerS). In Xenopus, antiSOX3c's effects on endodermin expression were suppressed by injection of RNA encoding a dominant negative version of Mixer or a morpholino against SOX17a2, both of which act downstream of nodal signaling in the endoderm specification pathway. Based on these data, it appears that maternal B1-type SOX functions together with the VegT/h-catenin system to regulate nodal expression and to establish the normal pattern of germ layer formation in Xenopus. A mechanistically conserved system appears to act in a similar manner in the zebrafish. D
Biochimica Et Biophysica Acta-biomembranes, 1998
There are several physiological and pharmacological evidences indicating that opening of voltage ... more There are several physiological and pharmacological evidences indicating that opening of voltage dependent calcium channels play a crucial role in the induction of the acrosome reaction in mammalian sperm. In mature sperm, physiological inductors of the acrosome reaction such as ZP3, a zona pellucida protein, and the steroid hormone progesterone, induce depolarization and calcium influx, which are required for the acrosome reaction. In this paper, we describe a voltage-dependent calcium influx present in human sperm. We report an experimental procedure that allows measurement of intracellular Ž . calcium and membrane potential simultaneously using the fluorescent dyes DiSC 5 and Fura-2. We found that in human 3 uncapacitated sperm, depolarization induces a nifedipine-insensitive calcium influx that, in most cases, was transient.
Espero que te gusten estas reflexiones Mudarse no es solo cambiar el lugar donde vivir ni se redu... more Espero que te gusten estas reflexiones Mudarse no es solo cambiar el lugar donde vivir ni se reduce a llamar a una empresa, para trasladar los muebles. Es abandonar el terreno conocido para embarcarse en los desconocido es cerrar una puerta, una etapa. Pero también es abrirse a otras posibilidades Es un nuevo comienzo dentro dela vida que continua. Porque la vida es cambio, transformación, mudanza ¡Haz tomado la decisión te acompañaremos en la hazaña!.
Journal of The Science of Food and Agriculture, 2005
Resistant starches were prepared from mango starch by extrusion. An experimental design with inde... more Resistant starches were prepared from mango starch by extrusion. An experimental design with independent variables temperature, screw speed and moisture content produced 20 samples that were studied to determine the effect of these variables on resistant starch (RS) content, water absorption index (WAI) and water solubility index (WSI). RS content was affected by moisture content and temperature. Screw speed and temperature also influenced RS content, the highest level (97 g kg−1) being obtained at low screw speed and high temperature, this pattern can be associated with a longer residence time, which gives rise to more opportunity for amylose chain association. The regression model fitted to the RS experimental results showed a good correlation coefficient (0.80). When moisture content and temperature decreased, WAI increased (105–142 g kg−1), but low WAI values (70–77 g kg−1) were obtained at moisture contents between 200 and 300 g kg−1 and high temperatures (140–150 °C). When moisture content and temperature increased, WSI increased (222–332 g kg−1), but at high temperature value (120 °C) assayed and the lowest moisture content (150 g kg−1), WSI also increased. In the range of moisture contents tested and at low temperatures, only partial gelatinisation occurred and low solubility was obtained. Copyright © 2005 Society of Chemical Industry
Journal of Agricultural and Food Chemistry, 1999
Two varieties of banana green fruit growing in Guerrero, Mexico, were used for starch isolation. ... more Two varieties of banana green fruit growing in Guerrero, Mexico, were used for starch isolation. Chemical analysis and physicochemical and functional properties were studied in these starches. The "macho" variety presented higher starch yield than "criollo". In general, chemical compositions in both starches were similar, except in ash content, where the "criollo" variety showed a lower value than "macho". The results of freeze-thaw stability suggested that banana starches cannot be used in frozen products. Both starches presented similar water retention capacity values that increased when temperature increased. Solubility profiles showed that at low temperature "criollo" had lower solubility than "macho", but at higher temperature an inverse behavior was evident; also the solubility increased when temperature increased. Behavior similar to that for solubility was obtained in the swelling test. The banana starch studies indicate the "macho" and "criollo" varieties have different starch structures as evidenced by viscosity.
Applied Soil Ecology, 2008
Biomarker Behaviour Earthworm a b s t r a c t
Developmental Biology, 2005
Specification of both neural crest cells and Rohon-Beard (RB) sensory neurons involves a complex ... more Specification of both neural crest cells and Rohon-Beard (RB) sensory neurons involves a complex series of interactions between the neural and non-neural ectoderm. The molecular mechanisms directing this process are not well understood. The zebrafish narrowminded (nrd) mutation is unique, since it is one of two mutations in which defects are observed in both cell populations: it leads to a complete absence of RB neurons and a reduction in neural crest cells and their derivatives. Here, we show that nrd is a mutation in prdm1, a SET/zincfinger domain transcription factor. A Morpholino-mediated depletion of prdm1 phenocopies the nrd mutation, and conversely overexpression of prdm1 mRNA rescues the nrd RB sensory neuron and neural crest phenotype. prdm1 is expressed at the border of the neural plate within the domain where neural crest cells and RB sensory neurons form. Analysis of prdm1 function by overexpression indicates that prdm1 functions to promote the cell fate specification of both neural crest cells and RB sensory neurons, most likely as a downstream effector of the BMP signaling pathway. D
Developmental Biology, 2004
B1-type SOXs (SOXs 1, 2, and 3) are the most evolutionarily conserved subgroup of the SOX transcr... more B1-type SOXs (SOXs 1, 2, and 3) are the most evolutionarily conserved subgroup of the SOX transcription factor family. To study their maternal functions, we used the affinity-purified antibody antiSOX3c, which inhibits the binding of Xenopus SOX3 to target DNA sequences [Development. 130(2003)5609]. The antibody also cross-reacts with zebrafish embryos. When injected into fertilized Xenopus or zebrafish eggs, antiSOX3c caused a profound gastrulation defect; this defect could be rescued by the injection of RNA encoding SOX3DC-EnR, a SOX3-engrailed repression domain chimera. In antiSOX3c-injected Xenopus embryos, normal animal -vegetal patterning of mesodermal and endodermal markers was disrupted, expression domains were shifted toward the animal pole, and the levels of the endodermal markers SOX17 and endodermin increased. In Xenopus, SOX3 acts as a negative regulator of Xnr5, which encodes a nodal-related TGFh-family protein. Two nodal-related proteins are expressed in the early zebrafish embryo, squint and cyclops; antiSOX3c-injection leads to an increase in the level of cyclops expression. In both Xenopus and zebrafish, the antiSOX3c phenotype was rescued by the injection of RNA encoding the nodal inhibitor Cerberus-short (CerS). In Xenopus, antiSOX3c's effects on endodermin expression were suppressed by injection of RNA encoding a dominant negative version of Mixer or a morpholino against SOX17a2, both of which act downstream of nodal signaling in the endoderm specification pathway. Based on these data, it appears that maternal B1-type SOX functions together with the VegT/h-catenin system to regulate nodal expression and to establish the normal pattern of germ layer formation in Xenopus. A mechanistically conserved system appears to act in a similar manner in the zebrafish. D
Biochimica Et Biophysica Acta-biomembranes, 1998
There are several physiological and pharmacological evidences indicating that opening of voltage ... more There are several physiological and pharmacological evidences indicating that opening of voltage dependent calcium channels play a crucial role in the induction of the acrosome reaction in mammalian sperm. In mature sperm, physiological inductors of the acrosome reaction such as ZP3, a zona pellucida protein, and the steroid hormone progesterone, induce depolarization and calcium influx, which are required for the acrosome reaction. In this paper, we describe a voltage-dependent calcium influx present in human sperm. We report an experimental procedure that allows measurement of intracellular Ž . calcium and membrane potential simultaneously using the fluorescent dyes DiSC 5 and Fura-2. We found that in human 3 uncapacitated sperm, depolarization induces a nifedipine-insensitive calcium influx that, in most cases, was transient.
Espero que te gusten estas reflexiones Mudarse no es solo cambiar el lugar donde vivir ni se redu... more Espero que te gusten estas reflexiones Mudarse no es solo cambiar el lugar donde vivir ni se reduce a llamar a una empresa, para trasladar los muebles. Es abandonar el terreno conocido para embarcarse en los desconocido es cerrar una puerta, una etapa. Pero también es abrirse a otras posibilidades Es un nuevo comienzo dentro dela vida que continua. Porque la vida es cambio, transformación, mudanza ¡Haz tomado la decisión te acompañaremos en la hazaña!.