93 research outputs found
Linear algebra and optimization based controller design for trajectory tracking of typical chemical process
This paper presents a new controller design to tracking trajectory of a typical chemical process. The plant model is represented by numerical methods and, from this approach, the control actions for an optimal operation of the system are obtained. Its main advantage is that the condition for the tracking error tends to zero and the calculation of control actions, are obtained solving a system of linear equations. The proofs of convergence to zero of the tracking error are presented. Simulation results show the good performance of the proposed control system.Fil: Serrano, Mario Emanuel. Universidad Nacional de San Juan. Facultad de Ingenieria. Instituto de Ingenieria Quimica; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Scaglia, Gustavo Juan Eduardo. Universidad Nacional de San Juan. Facultad de Ingenieria. Instituto de Ingenieria Quimica; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Aballay, P.. Universidad Nacional de San Juan. Facultad de Ingenieria. Instituto de Ingenieria Quimica; ArgentinaFil: Ortiz, O. A.. Universidad Nacional de San Juan. Facultad de Ingenieria. Instituto de Ingenieria Quimica; ArgentinaFil: Mut, Vicente Antonio. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico San Juan. Instituto de Automática; Argentin
A bright impulsive solar burst detected at 30 THz
Ground- and space-based observations of solar flares from radio wavelengths
to gamma-rays have produced considerable insights but raised several unsolved
controversies. The last unexplored wavelength frontier for solar flares is in
the range of submillimeter and infrared wavelengths. Here we report the
detection of an intense impulsive burst at 30 THz using a new imaging system.
The 30 THz emission exhibited remarkable time coincidence with peaks observed
at microwave, mm/submm, visible, EUV and hard X-ray wavelengths. The emission
location coincides with a very weak white-light feature, and is consistent with
heating below the temperature minimum in the atmosphere. However, there are
problems in attributing the heating to accelerated electrons. The peak 30 THz
flux is several times larger than the usual microwave peak near 9 GHz,
attributed to non-thermal electrons in the corona. The 30 THz emission could be
consistent with an optically thick spectrum increasing from low to high
frequencies. It might be part of the same spectral component found at sub-THz
frequencies whose nature remains mysterious. Further observations at these
wavelengths will provide a new window for flare studies.Comment: 9 pages, 11 figures, accepted by Astrophysical Journal, March 23,
201
A new method to estimate cloud cover fraction over El Leoncito Observatory from an all-sky imager designed for upper atmosphere studies
A method for determining cloud cover fraction over El Leoncito Observatory (31.8°S, 69.3°W) is presented. Data from an all-sky imaging system, designed to measure nightglow originating from the mesosphere and thermosphere, is used to determine the fraction of the sky covered by clouds. More than 9,000 hr of observations from May 2006 to December 2010 are used to show that El Leoncito is clear approximately 75-80% of the time. No significant seasonal variations are observed. The optical ground-based data are compared with data from the Moderate Resolution Imaging Spectro-radiometer (MODIS) instrument on board the TERRA and AQUA satellites.Fil: Martinis, C.. University Of Boston; Estados Unidos de AmĂ©rica;Fil: Wilson, J.. University of New Hampshire; Estados UnidosFil: Zablowski, P.. University Of Boston; Estados Unidos de AmĂ©rica;Fil: Baumgardner, J.. University Of Boston; Estados Unidos de AmĂ©rica;Fil: Aballay, Jose Luis. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - San Juan. Complejo AstronĂłmico "El Leoncito". Universidad Nacional de CĂłrdoba. Complejo AstronĂłmico "El Leoncito". Universidad Nacional de la Plata. Complejo AstronĂłmico "El Leoncito". Universidad Nacional de San Juan. Complejo AstronĂłmico "El Leoncito"; ArgentinaFil: Garcia, Beatriz Elena. Universidad Tecnologica Nacional; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Pque. Centenario. Instituto de TecnologĂa En DetecciĂłn y AstropartĂculas. Itedam - Subsede del Instituto de Tec. En DetecciĂłn y AstropartĂculas Mendoza | ComisiĂłn Nacional de EnergĂa AtĂłmica. Instituto de TecnologĂa En DetecciĂłn y AstropartĂculas. Itedam - Subsede del Instituto de Tec. En DetecciĂłn y AstropartĂculas Mendoza | Universidad Nacional de San Martin. Instituto de TecnologĂa En DetecciĂłn y AstropartĂculas. Itedam - Subsede del Instituto de Tec. En DetecciĂłn y AstropartĂculas Mendoza. ; Argentina; ArgentinaFil: Ristori, Pablo Roberto. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Unidad de InvestigaciĂłn y Desarrollo EstratĂ©gico para la Defensa. Ministerio de Defensa. Unidad de InvestigaciĂłn y Desarrollo EstratĂ©gico para la Defensa; ArgentinaFil: Otero, Lidia Ana. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Unidad de InvestigaciĂłn y Desarrollo EstratĂ©gico para la Defensa. Ministerio de Defensa. Unidad de InvestigaciĂłn y Desarrollo EstratĂ©gico para la Defensa; Argentin
High-Throughput Isolation and Mapping of C. elegans Mutants Susceptible to Pathogen Infection
We present a novel strategy that uses high-throughput methods of isolating and mapping C. elegans mutants susceptible to pathogen infection. We show that C. elegans mutants that exhibit an enhanced pathogen accumulation (epa) phenotype can be rapidly identified and isolated using a sorting system that allows automation of the analysis, sorting, and dispensing of C. elegans by measuring fluorescent bacteria inside the animals. Furthermore, we validate the use of Amplifluor® as a new single nucleotide polymorphism (SNP) mapping technique in C. elegans. We show that a set of 9 SNPs allows the linkage of C. elegans mutants to a 5–8 megabase sub-chromosomal region
Nucleolar Proteins Suppress Caenorhabditis elegans Innate Immunity by Inhibiting p53/CEP-1
The tumor suppressor p53 has been implicated in multiple functions that play key roles in health and disease, including ribosome biogenesis, control of aging, and cell cycle regulation. A genetic screen for negative regulators of innate immunity in Caenorhabditis elegans led to the identification of a mutation in NOL-6, a nucleolar RNA-associated protein (NRAP), which is involved in ribosome biogenesis and conserved across eukaryotic organisms. Mutation or silencing of NOL-6 and other nucleolar proteins results in an enhanced resistance to bacterial infections. A full-genome microarray analysis on animals with altered immune function due to mutation in nol-6 shows increased transcriptional levels of genes regulated by a p53 homologue, CEP-1. Further studies indicate that the activation of innate immunity by inhibition of nucleolar proteins requires p53/CEP-1 and its transcriptional target SYM-1. Since nucleoli and p53/CEP-1 are conserved, our results reveal an ancient immune mechanism by which the nucleolus may regulate immune responses against bacterial pathogens
A Role for the RNA Chaperone Hfq in Controlling Adherent-Invasive Escherichia coli Colonization and Virulence
Adherent-invasive Escherichia coli (AIEC) has been linked with the onset and perpetuation of inflammatory bowel diseases. The AIEC strain LF82 was originally isolated from an ileal biopsy from a patient with Crohn's disease. The pathogenesis of LF82 results from its abnormal adherence to and subsequent invasion of the intestinal epithelium coupled with its ability to survive phagocytosis by macrophages once it has crossed the intestinal barrier. To gain further insight into AIEC pathogenesis we employed the nematode Caenorhabditis elegans as an in vivo infection model. We demonstrate that AIEC strain LF82 forms a persistent infection in C. elegans, thereby reducing the host lifespan significantly. This host killing phenotype was associated with massive bacterial colonization of the nematode intestine and damage to the intestinal epithelial surface. C. elegans killing was independent of known LF82 virulence determinants but was abolished by deletion of the LF82 hfq gene, which encodes an RNA chaperone involved in mediating posttranscriptional gene regulation by small non-coding RNAs. This finding reveals that important aspects of LF82 pathogenesis are controlled at the posttranscriptional level by riboregulation. The role of Hfq in LF82 virulence was independent of its function in regulating RpoS and RpoE activity. Further, LF82Δhfq mutants were non-motile, impaired in cell invasion and highly sensitive to various chemical stress conditions, reinforcing the multifaceted function of Hfq in mediating bacterial adaptation. This study highlights the usefulness of simple non-mammalian infection systems for the identification and analysis of bacterial virulence factors
Nutritional profile and obesity: results from a random‑sample population‑based study in Córdoba, Argentina
Introduction Obesity is a chronic, heterogeneous, multifactorial disease, which has sharply increased in prevalence in both developed and developing countries. This study aimed to estimate the prevalence of obesity and to identify socio-demographic risk factors associated with it, with special emphasis on diet. Methods Nutritional status, demographic characteristics, lifestyle habits, and food consumption patterns derived from a Food Frequency Questionnaire were investigated. Exhaustive exploratory analyses were performed in order to describe dietary patterns, and logistic regression models were used for odds ratio estimation.
Results The study included 4328 subjects, over 18 years old and resident in Cordoba city. The prevalence of overweight and obesity was 34 and 17 %, respectively, with 60 % in men and 45 % in women of BMI ≥ 25. Obesity risk factors were high intake of sodium, refined grains, starchy vegetables, and snacks. A lower risk of overweight and obesity was associated with an adequate, moderate intake of meats, eggs, alcoholic beverages, sugar and sweets, milk, yogurt, and pulses. Conclusions A high intake of snacks, refined grains, starchy vegetables and sodium and low intake of yogurt, milk, pulses, and whole grains seem to be associated with the emergence and high prevalence of obesity in Cordoba, Argentina.publishedVersionFil: Aballay, Laura Rosana. Universidad Nacional de CĂłrdoba. Facultad de Ciencias MĂ©dicas. Escuela de NutriciĂłn. EstadĂstica y BioestadĂstica; ArgentinaFil: Aballay, Laura Rosana. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Investigaciones en Ciencias de la Salud; Argentina.Fil: De la Quintana, Ana Gabriela. Universidad Nacional de CĂłrdoba. Facultad de Ciencias MĂ©dicas. Escuela de NutriciĂłn; Argentina.Fil: DĂaz, MarĂa del Pilar. Universidad Nacional de CĂłrdoba. Facultad de Ciencias MĂ©dicas. Escuela de NutriciĂłn. EstadĂstica y BioestadĂstica; Argentina.Fil: DĂaz, MarĂa del Pilar. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Instituto de Investigaciones en Ciencias de la Salud; Argentina.Fil: Osella, Alberto R. Hospital Saverio de Bellis. Laboratorio de Epidemiologia y BioestadĂstica; Italia
LEM-3 – A LEM Domain Containing Nuclease Involved in the DNA Damage Response in C. elegans
The small nematode Caenorhabditis elegans displays a spectrum of DNA damage responses similar to humans. In order to identify new DNA damage response genes, we isolated in a forward genetic screen 14 new mutations conferring hypersensitivity to ionizing radiation. We present here our characterization of lem-3, one of the genes identified in this screen. LEM-3 contains a LEM domain and a GIY nuclease domain. We confirm that LEM-3 has DNase activity in vitro. lem-3(lf) mutants are hypersensitive to various types of DNA damage, including ionizing radiation, UV-C light and crosslinking agents. Embryos from irradiated lem-3 hermaphrodites displayed severe defects during cell division, including chromosome mis-segregation and anaphase bridges. The mitotic defects observed in irradiated lem-3 mutant embryos are similar to those found in baf-1 (barrier-to-autointegration factor) mutants. The baf-1 gene codes for an essential and highly conserved protein known to interact with the other two C. elegans LEM domain proteins, LEM-2 and EMR-1. We show that baf-1, lem-2, and emr-1 mutants are also hypersensitive to DNA damage and that loss of lem-3 sensitizes baf-1 mutants even in the absence of DNA damage. Our data suggest that BAF-1, together with the LEM domain proteins, plays an important role following DNA damage – possibly by promoting the reorganization of damaged chromatin
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