1,895 research outputs found
An Application of SVM to Lost Packets Reconstruction in Voice-Enabled Services
Voice over IP (VoIP) is becoming very popular due to the huge range of services that can be implemented by integrating different media (voice, audio, data, etc.). Besides, voice-enabled interfaces for those services are being very actively researched. Nevertheless the impoverishment of voice quality due to packet losses severely affects the speech recognizers supporting those interfaces ([8]). In this paper, we have compared the usual lost packets reconstruction method with an SVM-based one that outperforms previous results
Control químico de enfermedades en trigo.
Se estudió la factibilidad del empleo de productos químicos para prevenir enfermedades, su rentabilidad y su efecto en el aumento de la producción en trigo. Se emplearon 11 variedades de trigo, de distintos orígenes y susceptibles a diferentes enfermedades. Se efectuaron 6 aplicaciones con el fungicida dithane M-22 en dosis de 3 kg/ha. La aplicación del producto dithane M-22 redujo en alto grado la incidencia de enfermedades y por lo tanto incrementó significativamente el rendimiento, el peso hectolítrico y el peso de mil granos. Con todas las variedades tratadas se obtuvieron resultados muy superiores con relación a las no tratadas. Se puede deducir que la aplicación de dithane M-22 resulta económica y que es importante programar ensayos a nivel comercial y ensayar diferentes tipos de maquinaria para poder recomendar esta práctica a los agricultoresMaestría en CienciasMaestrí
Mitochondrial inhibitors activate influx of external Ca2+ in sea urchin sperm
AbstractSea urchin sperm have a single mitochondrion which, aside from its main ATP generating function, may regulate motility, intracellular Ca2+ concentration ([Ca2+]i) and possibly the acrosome reaction (AR). We have found that acute application of agents that inhibit mitochondrial function via differing mechanisms (CCCP, a proton gradient uncoupler, antimycin, a respiratory chain inhibitor, oligomycin, a mitochondrial ATPase inhibitor and CGP37157, a Na+/Ca2+ exchange inhibitor) increases [Ca2+]i with at least two differing profiles. These increases depend on the presence of extracellular Ca2+, which indicates they involve Ca2+ uptake and not only mitochondrial Ca2+ release. The plasma membrane permeation pathways activated by the mitochondrial inhibitors are permeable to Mn2+. Store-operated Ca2+ channel (SOC) blockers (Ni2+, SKF96365 and Gd2+) and internal-store ATPase inhibitors (thapsigargin and bisphenol) antagonize Ca2+ influx induced by the mitochondrial inhibitors. The results indicate that the functional status of the sea urchin sperm mitochondrion regulates Ca2+ entry through SOCs. As neither CCCP nor dicycloexyl carbodiimide (DCCD), another mitochondrial ATPase inhibitor, eliminate the oligomycin induced increase in [Ca2+]i, apparently oligomycin also has an extra mitochondrial target
Multiple classification of the force and acceleration signals extracted during multiple machine processes: part 1 intelligent classification from an anomaly perspective
This paper is the first in a two-part work, where the investigation into the characteristics of multiple machine processes is made in order to accurately control them via the frequently used machine centre platform. The two machining processes under investigation are grinding and hole making: for grinding anomalies, grinding burn and chatter and for hole making, drilling, increased tool wear and onset of drill tool malfunction, which is also significant to severe scoring and material dragging. Most researchers usually report on one machining process as opposed to multiple which is less consistent with automated flexible systems where more than one machining process must be catered for. For efficient monitoring of automated multiple manufacturing processes, any unwanted anomalies should be identified and dealt with in a prompt and seamless manner. This first part provides two experimental set-ups (same set-up with tool interchange) to obtain signal signatures for both grinding and drilling phenomena (using the same material). Here, an approach based on neural networks and CARTs is used to reliably detect anomalies for both processes using a single acquisition path, opening the door for control implementation
Activation of nucleus accumbens NMDA receptors differentially affects appetitive or aversive taste learning and memory
Taste memory depends on motivational and post-ingestional consequences; thus, it can be aversive (e.g., conditioned taste aversion, CTA) if a novel, palatable taste is paired with visceral malaise, or it can be appetitive if no intoxication appears after novel taste consumption, and a taste preference is developed.The nucleus accumbens (NAc) plays a role in hedonic reactivity to taste stimuli, and recent findings suggest that reward and aversion are differentially encoded by the activity of NAc neurons. The present study examined whether the requirement for N-methyl-D-aspartate (NMDA) receptors in the NAc core during rewarding appetitive taste learning differs from that during aversive taste conditioning, as well as during retrieval of appetitive vs. aversive taste memory, using the taste preference or CTA model, respectively. Bilateral infusions of NMDA (1 μg/μl, 0.5 μl) into the NAc core were performed before acquisition or before retrieval of taste preference or CTA. Activation of NMDA receptors before taste preference training or CTA acquisition did not alter memory formation. Furthermore, NMDA injections before aversive taste retrieval had no effect on taste memory; however, 24 h later, CTA extinction was significantly delayed. Also, NMDA injections, made before familiar appetitive memory retrieval, interrupted the development of taste preference and produced a preference delay 24 h later. These results suggest that memory formation for a novel taste produces neurochemical changes in the NAc core that have differential requirements for NMDA receptors during retrieval of appetitive or aversive memory
Synthesis and Effect of CaTiO3 formation in CaO·Al2O3 by Solid-State Reaction from CaCO3· Al2O3 and Ti
CaO⋅Al2O3/CaTiO3 material was synthesized by a solid-state reaction. The effects of CaTiO3 formed into the CaO⋅Al2O3 during the synthesized process on the microstructure and mechanical properties were studied. CaCO3 was obtained from snail shells, Al2O3, and Ti powders were employed as a raw material. A chemical system with a 1:1 M ratio between CaCO3 and Al2O3 was formed, with an addition of 10 wt% Ti metallic particles. The microstructural analysis through optical microscopy, scanning electron microscopy, and X-ray diffraction was realized. The apparent density was determined by the Archimedes method, and the mechanical behavior (hardness, fracture
toughness, and transversal elastic modulus) were also determined. XRD analysis revealed the formation of calcium aluminate phases such as CaAl2O4, CaAl4O7, and CaAl12O19; in addition, the CaTiO3 phase was also identified. The in-situ formation of CaTiO3 in the ceramic material, improves the mechanical properties such as the transversal elastic modulus and fracture toughness (48 GPa and 1.32 MPa m1/2, respectively) in comparison to the reference material (55 GPa and 0.43 MPa m1/2, respectively). Changes in the microstructural morphology, bulk density, and hardness values were also observed with a positive effect in the compound material
Alkaline pretreatment of Mexican pine residues for bioethanol production
The locally sourced residue samples of Pinus arizonica, Pinus cooperi, and Pinus durangensis from the state of Durango in Mexico were analyzed for optimal yield of ethanol production. The samples were mixed at an equal proportion using a particle size of 0.59 mm. Each individual mixture was pretreated with either NaOH or Ca (OH)2 (at 0.5, 1.0 and 1.5% w/v) for periods of 30, 60, and 90 min at 60, 90, and 120°C. The pretreated blending was subjected to enzymatic hydrolysis for 130 h at 80 rpm and 50°C with an enzymatic load of 25 filter paper units (FPU) and 50 IU β-glucosidase per gramme of cellulose to obtain a maximum yield of reducing sugars (RS) with NaOH subject at 120°C for 90 min. The results show that the hydrolysis yield depends on temperature and alkali concentration particularly (NaOH), which increased from 2.0 to 3.5% w/v. The best yield of glucose (41.33% w/w) was obtained using a pretreatment of 2.5% NaOH for 90 min, 120°C, and a hydrolysis residence time of 130 h. The removal of lignin and hemicellulose acetylation was observed to have influence on the enzymatic digestibility of cellulose. This process could theoretically produce a maximum yield of 90.19% of ethanol / substrate (glucose) and about 80 L of bioethanol per dry ton of woody biomass from pine residues.Keywords: Lignocellulosic biomass, alkaline pretreatment, enzymatic hydrolysis, fermentable sugars, fermentationAfrican Journal of Biotechnology Vol. 12(31), pp. 4956-496
Resistance and inactivation kinetics of bacterial strains isolated from the Non-chlorinated and chlorinated effluents of a WWTP
The microbiological quality of water from a wastewater treatment plant that uses sodium hypochlorite as a disinfectant was assessed. Mesophilic aerobic bacteria were not removed efficiently. This fact allowed for the isolation of several bacterial strains from the effluents. Molecular identification indicated that the strains were related to Aeromonas hydrophila, Escherichia coli (three strains), Enterobacter cloacae, Kluyvera cryocrescens (three strains), Kluyvera intermedia, Citrobacter freundii (two strains), Bacillus sp. and Enterobacter sp. The first five strains, which were isolated from the non-chlorinated effluent, were used to test resistance to chlorine disinfection using three sets of variables: disinfectant concentration (8, 20 and 30 mg·L−1), contact time (0, 15 and 30 min) and water temperature (20, 25 and 30 °C). The results demonstrated that the strains have independent responses to experimental conditions and that the most efficient treatment was an 8 mg·L−1 dose of disinfectant at a temperature of 20 °C for 30 min. The other eight strains, which were isolated from the chlorinated effluent, were used to analyze inactivation kinetics using the disinfectant at a dose of 15 mg·L−1 with various retention times (0, 10, 20, 30, 60 and 90 min). The results indicated that during the inactivation process, there was no relationship between removal percentage and retention time and that the strains have no common response to the treatmentsThe work of SM-H was supported by a graduate scholarship (number 217745) that was kindly provided by CONACyT, Mexico. Some chemical reagents were generously provided by the Administration of the B.A. in Biology at UAEH, Mexico. We thank the Instituto Tecnológico de Estudios Superiores de Monterrey, Hidalgo campus, for allowing us to sample from its WWTP. The authors recognize Jose A. Rodriguez-Ávila for his comments on the procedure for analyzing inactivation kineticsS
Effect of 8-Week Consumption of a Dietary Pattern Based on Fruit, Avocado, Whole Grains, and Trout on Postprandial Inflammatory and Oxidative Stress Gene Expression in Obese People
Overweight and obesity constitute a major global public health problem. Healthy dietary patterns induce changes at the molecular level. Currently, there are no studies evaluating the effect of a diet based on fruit, avocado, whole grains, and trout (FAWGT diet) on the expression of obesity-related genes. This randomized controlled crossover study included 44 obese Colombians with BMI ≥30 kg/m2 who followed either a FAWGT diet or a usual diet (UD) characterized by a high intake of saturated fat and foods rich in processed carbohydrates. After 8 weeks of intervention, a postprandial expression study of inflammation and oxidative stress-related genes was carried out with a real-time PCR. The intervention with a FAWGT diet decreased the expression of inflammatory (NFKB1, IL6, IL1β) and oxidative stress (NFE2L2) genes compared with the intake of the UD. Finally, the postprandial expression of NFkB1 was positively correlated with triglyceride levels after a dietary intervention with the FAWGT diet and the IL1β gene, and likewise with insulin levels after following the usual diet. The consumption of the FAWGT diet for 8 weeks reduced the inflammatory status; thus, it can be considered a valid alternative to other healthy diets, since it induces beneficial changes on the genes involved in inflammation and oxidative stress in obese people
Growth Kinetics for the Selection of Yeast Strains for Fermented Beverages
Criteria to select autochthonous yeast strains for their use in fermented beverages include their ability to dominate the media and to enhance desired sensorial characteristics and their inability to produce undesired compounds such as biogenic amines or off-odors. One of the key features in yeast selection is its Implantation, surpassing different stresses, and its fermentation performance, which requires setting up the process and monitoring it, involving important amount of resources. Methods to evaluate the tolerance of yeast strains are usually based in the qualitative measure of the growth of the microorganism in a medium containing the limiting compound after a specific time of incubation. However, studying strain growth through optical density measurements permits to estimate quantitative and comparable parameters providing an insight into the fitness of the cell to certain environment, lag phase duration, growth rate, and maximum population, among others. In the last decades, culture-independent methods have been used to evaluate the dynamic of microbial populations during fermentative process. In this chapter, a review of recent advances in the selection of fermentative yeasts as well as the utilization of kinetic evaluation and molecular strategies in conditions associated with fermented beverage for selecting yeast strains is presented
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