santiago torres - Profile on Academia.edu (original) (raw)

Papers by santiago torres

Acta Oceanográfica, 2021

Estas observaciones destacan el uso potencial de estos vertebrados marinos homotermos, como eco-i... more Estas observaciones destacan el uso potencial de estos vertebrados marinos homotermos, como eco-indicadores de productividad primaria. Varias especies de mamíferos y aves marinas, incluyendo especies amenazadas, fueron registradas en zonas de alimentación fuera de los límites de la Reserva Marina de Galápagos (RMG), lo que implica el riesgo de pesca incidental debido a palangres, trasmallos y otros impactos antropogénicos en esas zonas desprotegidas.

Avances en Ciencias e Ingeniería, 2011

This paper presents the preliminary results of an undergoing study about the implementation of RF... more This paper presents the preliminary results of an undergoing study about the implementation of RFID technology in the shoe industry in Ecuador. As a starting point, descriptions about the benefits and limitation of RFID and the logistics scenario in Ecuador are provided. Then, the implications of adopting RFID along the entire shoe supply chain are discussed, including two governmental control agencies. Finally, some additional considerations such as implementation challenges and financial implications are discussed.

Comunicación, Lenguaje y Educación, 1991

Los sistemas paraverbales o que acompañan al habla son necesarios a todo hablante «normal». Algun... more Los sistemas paraverbales o que acompañan al habla son necesarios a todo hablante «normal». Algunos pueblos, como los latinos (frente a los anglosajones, por ejemplo), hacemos uso generoso y eficiente de ellos. Un trabajo sistemático con ellos ha permitido poner en marcha un método eficaz para la educación del lenguaje oral en niños sordos. En este artículo se expone en detalle el sistema, sus implicaciones y eficacia y los pasos a dar para su aplicación. 30 segundos me son suficientes para que un sordo profundo comprenda para qué sirve la PC. Pero no me bastan 30 minutos para hacérsela comprender a un oyente.

Number Counts of White Dwarfs: The Impact of GAIA

Astrophysics and Space Science Library

Enrique Garcia-Berro1, Santiago Torres1,2, Francesca Figueras 2,3, Jordi Isern2,4 1 Dep artament ... more Enrique Garcia-Berro1, Santiago Torres1,2, Francesca Figueras 2,3, Jordi Isern2,4 1 Dep artament de Física Apl icada, Universitat d Politècnica de Catalunya, Escola Politécnica Po Superior de Castelldefe ls Av. del Canal Olímpic s/n, 08860, Castelldef els, Spain f 2 Institut I d'Estudis ...

Generation of emotional-based causal inferences in students with high and low reading levels | La generación de inferencias causales de naturaleza emocional en sujetos con alto y bajo nivel lector

ABSTRACT Se analizan las habilidades lectoras de estudiantes de Educación Secundaria Obligatoria ... more ABSTRACT Se analizan las habilidades lectoras de estudiantes de Educación Secundaria Obligatoria (ESO) para realizar inferencias causales de contenido emocional en la lectura de los textos narrativos. Se intenta evidenciar si la activación de los estados emocionales de los protagonistas de un texto narrativo se halla mediada por el nivel lector de los sujetos. 45 sujetos de edades comprendidas entre los 12 y los 16 años fueron clasificados en tres niveles en función de su habilidad lectora. Posteriormente los sujetos tuvieron que leer una serie de narraciones cortas mediante una técnica de lectura autoadministrada. Los resultados confirmaron la hipótesis de que la activación de los estados emocionales de los protagonistas de las historias se hallaba mediada por el nivel lector de los sujetos.

The white dwarf cooling age of NGC 6791

... Torres∗,†, Pablo Lorén–Aguilar∗,†, Isabel Renedo∗,†, Alejandro H. Córsico∗∗, Jordi Isern‡,†,M... more ... Torres∗,†, Pablo Lorén–Aguilar∗,†, Isabel Renedo∗,†, Alejandro H. Córsico∗∗, Jordi Isern‡,†,Maurizio Salaris§ and ... y Geofísicas, Universidad Nacional de La Plata-IALP(CONICET), Paseodel Bosque s ... Ciències de l'Espai, CSIC, Campus UAB, Facultat de Ciències, Torre C-5 ...

Archives of Toxicology, 2001

The aim of this study was to evaluate the acute hepatic effects exerted by the steroid hormone pr... more The aim of this study was to evaluate the acute hepatic effects exerted by the steroid hormone progesterone (PR) in the rat. Although the liver is not a target tissue for this hormone, a number of hepatic actions of PR have been described, and, furthermore, a specific binding site for PR (PBS) exists in rat liver microsomes. Immature male rats were treated intraperitoneally with 60 mg/kg PR per day for 1, 5 or 10 days, and different parameters were evaluated in order to detect possible alterations in liver cells. Morphological study of the livers did not present images of cytotoxicity in any group of animals. The presence of a clear hyperplasia of smooth endoplasmic reticulum (SER) was noteworthy, mainly seen in perilobular hepatocytes. Despite this SER increase, the levels of cytochrome P450 (Cyt P450) significantly decreased after 10 days of PR administration. Similarly, the concentration of PBS was significantly decreased after 10 days of treatment with PR. On the other hand, these studies revealed a clear increase of mitotic activity and Ki-67 labelling index in the livers of animals treated with PR; furthermore, livers of PRtreated animals showed an increased percentage of binucleate hepatocytes. Flow cytometry analysis showed that although ploidy status of liver cells was not modified in any case the percentage of diploid nuclei in Sphase decreased during treatment with PR. The most relevant finding was the presence of abnormal mitosis and c-mitosis in livers from animals from all PR-treated groups. This study demonstrates that PR (a) does not induce cytotoxicity although it can induce cell proliferation and spindle disturbances in liver cells, (b) may also modulate the drug-metabolizing liver enzyme function, and (c) downregulates the expression of its own microsomal specific binding site.

Cytometry, 2001

Background: In this paper, we used a small crustacean as a model to develop a method for quantify... more Background: In this paper, we used a small crustacean as a model to develop a method for quantifying growth rates through the measurement of a cell proliferation marker. This was done in order to study the feasibility of this assay for estimating zooplankton production in the ocean. Flow cytometry immunodetection of bromodeoxyuridine (BrdU) was performed to detect and quantify the cycling nuclei of Daphnia magna. Methods: A combination of mechanical dissociation and cell enucleation procedures proved to be the most convenient method for preparing nuclear suspensions from whole organisms. Up to three populations of nuclei with different ploidy were observed. The relative abundance of these nuclear populations changed with the size of the flea. Results: The staining technique has been optimized. The time and concentration for the maximum detection of BrdU-labeled nuclei were 3 h at 300 M BrdU. Whole organisms can be frozen (-20°C) after incubation with no changes in the final results. The method was used in different physiological conditions under controlled food and temperature in order to test the inverse relationship between physiological rates and size of organisms at several developmental stages. The quantification of BrdUlabeled nuclei in 1-6 day-old larvae showed the highest labeling index, with a mean of 95 Ϯ 1% (n ϭ 22). In contrast, young animals (0.8-1.2 mm) had 25 Ϯ 4% (n ϭ16, P Ͻ 0.001) and adults (Ͼ1.4mm) had 14 Ϯ 3% (n ϭ 4, P Ͻ 0.001). The results obtained show an expected tendency, suggesting that a direct relationship exists between the labeling index and the instantaneous growth rate. Conclusions: Certain features of our method, such as the short times required for labeling and the possibility of preserving the samples during field experiments and under different conditions (including natural concentrations and types of food), are advantageous to the study of processes governing energy fluxes in pelagic ecosystems. Cytometry 44:264-271, 2001.

Astronomy & Astrophysics, 2014

Context. Detached white dwarf + main sequence (WD+MS) systems represent the simplest population o... more Context. Detached white dwarf + main sequence (WD+MS) systems represent the simplest population of post-common envelope binaries (PCEBs). Since the ensemble properties of this population carries important information about the characteristics of the common-envelope (CE) phase, it deserves close scrutiny. However, most population synthesis studies do not fully consider the effects of the observational selection biases of the samples used to compare with the theoretical simulations. Aims. Here we present the results of a set of detailed Monte Carlo simulations of the population of WD+MS binaries in the Sloan Digital Sky Survey (SDSS) Data Release 7. Methods. We used up-to-date stellar evolutionary models, a complete treatment of the Roche lobe overflow episode, and a full implementation of the orbital evolution of the binary systems. Moreover, in our treatment we took the selection criteria and all the known observational biases into account. Results. Our population synthesis study allowed us to make a meaningful comparison with the available observational data. In particular, we examined the CE efficiency, the possible contribution of internal energy, and the initial mass ratio distribution (IMRD) of the binary systems. We find that our simulations correctly reproduce the properties of the observed distribution of WD+MS PCEBs. In particular, we find that once the observational biases are carefully considered, the distribution of orbital periods and of masses of the WD and MS stars can be correctly reproduced for several choices of the free parameters and different IMRDs, although models in which a moderate fraction (≤10%) of the internal energy is used to eject the CE and in which a low value of CE efficiency is used (≤0.3) seem to fit the observational data better. We also find that systems with He-core WDs are over-represented in the observed sample, because of selection effects. Conclusions. Although our study represents an important step forward in modeling the population of WD+MS PCEBs, the still scarce observational data preclude deriving a precise value of the several free parameters used to compute the CE phase without ambiguity or ascertaining which the correct IMRD might be.

Model-based controller for anesthesia automation

2009 IEEE International Conference on Automation Science and Engineering, 2009

This paper presents an approach to anesthesia control using a model-based controller. General ane... more This paper presents an approach to anesthesia control using a model-based controller. General anesthesia with propofol is considered. The proposal tries to take advantage of the benefits of model-based controllers to improve the performance of control in anesthesia. The controller proposed is based on the application of two control actions. First, a nominal term is applied obtained from the inverse

BabelWin: An environment for learning and monitoring reading and writing skills

Computers and Education in the 21st Century

First record of Brown Noddy Anous stolidus for the South American Pacific coast

Toxicology, 2002

Nonylphenol (NP) and 4-Octylphenol (4OP) have shown estrogenic properties both in vivo and in vit... more Nonylphenol (NP) and 4-Octylphenol (4OP) have shown estrogenic properties both in vivo and in vitro. Researchers have known for years that estrogens induce a wide number of hepatotoxic actions in rodents. In order to study the acute hepatic effects exerted by NP and 4OP on rat liver the following endpoints were evaluated: relative liver weight (RLW), morphology, cell cycle and ploidy status, monooxygenase enzymes content and levels of both, cytosolic estrogen receptor (cER) and microsomal binding sites for estrogens (mEBS). Immature male Sprague-Dawley rats were injected intraperitoneally (i.p.) with 60 mg/kg of NP or 4OP for 1, 5 or 10 days. Despite the fact that RLW of the animals was not modified but any treatment, the histopathological study revealed the presence of an increase in the percentage of both, mitotic activity and Ki-67-labeling index (LI) in the livers from animals treated with alkylphenols in absence of any degenerative lesion. Furthermore, all the livers from alkylphenols-treated groups showed the presence of abnormal mitosis and c-mitosis. Although the levels of both, cER and cytochrome P450 (Cyt. P450) were not affected by any treatment, concentration of the mEBS was decreased after 10 days of treatment with alkylphenols. These findings taken together suggest that the exposition to alkylphenols induce cell proliferation and

Loss and Retention of RNA Interference in Fungi and Parasites

PLoS Pathogens, 2013

An Application of a Neural Self-Tuning Controller to an Overhead Crane

Neural Computing & Applications, 1999

... Overhead Crane JA Méndez, L. Acosta, L. Moreno, S. Torres and GN Marichal ... The plant is an... more ... Overhead Crane JA Méndez, L. Acosta, L. Moreno, S. Torres and GN Marichal ... The plant is anoverhead crane which involves an interesting control problem related to the oscillations of the load mass. The method pro-posed is tested by simulation in different conditions. ...

Monthly Notices of the Royal Astronomical Society, 2006

The white dwarf luminosity function is an important tool for the study of the solar neighbourhood... more The white dwarf luminosity function is an important tool for the study of the solar neighbourhood, since it allows the determination of the age of the Galactic disc. Over the years, several methods have been proposed to compute galaxy luminosity functions, from the most simple ones-counting sample objects inside a given volume-to very sophisticated oneslike the C − method, the STY method or the Choloniewski method, among others. However, only the 1/V max method is usually employed in computing the white dwarf luminosity function and other methods have not been applied so far to the observational sample of spectroscopically identified white dwarfs-in sharp contrast with the situation when galaxy luminosity functions are derived from a large variety of samples. Moreover, the statistical significance of the white dwarf luminosity function has also received little attention and a thorough study still remains to be done. In this paper, we study, using a controlled synthetic sample of white dwarfs generated using a Monte Carlo simulator, which is the statistical significance of the white dwarf luminosity function and which are the expected biases. We also present a comparison between different estimators for computing the white dwarf luminosity function. We find that for sample sizes large enough the 1/V max method provides a reliable characterization of the white dwarf luminosity function, provided that the input sample is selected carefully. Particularly, the 1/V max method recovers well the position of the cutoff of the white dwarf luminosity function. However, this method turns out to be less robust than the Choloniewski method when the possible incompletenesses of the sample are taken into account. We also find that the Choloniewski method performs better than the 1/V max method in estimating the overall density of white dwarfs, but misses the exact location of the cutoff of the white dwarf luminosity function.

Molecular Genetics and Genomics, 2001

Mucor circinelloides responds to blue light by activating carotene biosynthesis. Wild-type strain... more Mucor circinelloides responds to blue light by activating carotene biosynthesis. Wild-type strains grown in darkness contain minimal amounts of b-carotene because of the low levels of transcription of the structural genes for carotenogenesis. When exposed to a light pulse, the level of transcription of these genes increases strongly, leading to the formation of high concentrations of b-carotene. The crgA gene is involved in the regulation of light-induced carotenoid biosynthesis. This gene, originally identi®ed as a 3¢-truncated ORF which causes carotene over-accumulation in the dark, encodes a protein with a cysteine-rich, zinc-binding, RING-®nger motif, as found in diverse groups of regulatory proteins. The expression of the crgA gene is activated by a light pulse, with a time course similar to that of the structural genes for carotenogenesis. To understand the regulatory role of the crgA gene in carotenogenesis, we have used a genetic approach based on the construction of crgA null mutants by gene replacement. Lack of the crgA function provokes the overaccumulation of carotenoids both in the dark and the light. Introduction of the wild-type crgA allele into these mutants restores the wild-type phenotype for carotenogenesis. The high levels of carotenoid accumulation shown by the null crgA mutants are correlated with an increase in the expression of carotenogenic structural genes. These results strongly indicate that crgA acts as a negative regulator of light-inducible carotenogenesis in M. circinelloides.

The relationship between ammonia excretion and GDH activity in marine zooplankton

Journal of Plankton Research, 1997

Linking Genome Annotation Projects with Genetic Disorders using Ontologies

Journal of Medical Systems, 2012