3,474 research outputs found
Efficient cloning system for construction of gene silencing vectors in Aspergillus niger
An approach based on Gateway recombination technology to efficiently construct silencing vectors was developed for use in the biotechnologically important fungus Aspergillus niger. The transcription activator of xylanolytic and cellulolytic genes XlnR of A. niger was chosen as target for gene silencing. Silencing was based on the expression vector pXLNRir that was constructed and used in co-transformation. From all the strains isolated (N = 77), nine showed poor xylan-degrading activities in two semi-quantitative plate assays testing different activities for xylan degradation. Upon induction on D-xylose, transcript levels of xlnR were decreased in the xlnR-silenced strains, compared to a wild-type background. Under these conditions, the transcript levels of xyrA and xynB (two genes regulated by XlnR) were also decreased for these xlnR-silenced strains. These results indicate that the newly developed system for rapid generation of silencing vectors is an effective tool for A. niger, and this can be used to generate strains with a tailored spectrum of enzyme activities or product formation by silencing specific genes encoding, e.g., regulators such as Xln
Suministro De La Demanda De EnergĂa En El Procesamiento De Carne De Pollo Con BiogĂĄs
The main use of electrical energy in the chicken meat processing unit is refrigeration. About 70% of the electricity is consumed in the compressors for the refrigeration system. Through this study, the energetic viability of using biogas from poultry litter in supplying the demand for the refrigeration process was found. The meat processing unit studied has the potential to process about a hundred and sixty thousand chickens a day. The potential biogas production from poultry litter is 60,754,298.91 m3.year-1. There will be a surplus of approximately 8,103 MWh per month of electric energy generated from biogas. An economic analysis was performed considering a planning horizon of 20 years and the discount rate of 12% per year. The economic analysis was performed considering scenario 1: sale of all electricity generated by the thermoelectric facility, and scenario 2: sale of the surplus electricity generated after complying with the demands of the refrigeration process and all other electrical energy and thermal energy use. Economic indicators obtained for scenarios 1 and 2 were favorable for the project implementation. Š 2016, Revista Ingenieria e Investigacion - Editorial Board. All Rights reserved.36111812
The VMC survey III : Mass-loss rates and luminosities of LMC AGB stars
Context. Asymptotic giant branch (AGB) stars are major contributors to both the chemical enrichment of the interstellar medium and the integrated light of galaxies. Despite its importance, the AGB is one of the least understood phases of stellar evolution. The main difficulties associated with detailed modelling of the AGB are related to the mass-loss process and the 3rd dredge-up efficiency Aims. We provide direct measures of mass-loss rates and luminosities for a complete sample of AGB stars in the Large Magellanic Cloud, disentangling the C- and O-rich stellar populations. Methods. Dust radiative transfer models are presented for all 374 AGB stars candidates in one of the fields observed by the new VISTA survey of the Magellanic Clouds (VMC). Mass-loss rates, luminosities and a classification of C-and O-rich stars are derived by fitting the models to the spectral energy distribution (SED) obtained by combining VMC data with existing optical, near-, and mid-infrared photometry. Results. The classification technique is reliable at a level of - at worst -75% and significantly better for the reddest dusty stars. We classified none of the stars with a relevant mass-loss rate as O-rich, and we can exclude the presence of more than one dusty O-rich star at a similar to 94% level. The bolometric luminosity function we obtained is fully consistent with most of the literature data on the LMC and with the prediction of theoretical models, with a peak of the C-star distribution at M-bol similar or equal to -4.8 mag and no stars brighter than the classical AGB tip, at M-bol = -7.1 mag. Conclusions. This exploratory study shows that our method provides reliable mass-loss rates, luminosities and chemical classifications for all AGB stars. These results offer already important constraints to AGB evolutionary models. Most of our conclusions, especially for the rarer dust-enshrouded extreme AGB stars, are however strongly limited by the relatively small area covered by our study. Forthcoming VMC observations will easily remove this limitation.Peer reviewe
Superdiffusive Conduction: AC Conductivity with Correlated Noise
We present evidence of the existence of a superdiffusive regime in systems
with correlated disorder for which localization is suppressed. An expression
for anomalous electrical conductivity at low frequencies is found by using a
generalized Langevin equation whose memory function accounts for the
interactions between the carriers. New mechanisms inducing a superdiffusive
conductivity are discussed and experimental possibilities for observing that
phenomenon in nanotubes and superlattices are presented.Comment: 7 pages, no figure
Nonintegrable Interaction of Ion-Acoustic and Electromagnetic Waves in a Plasma
In this paper we re-examine the one-dimensional interaction of
electromagnetic and ion acoustic waves in a plasma. Our model is similar to one
solved by Rao et al. (Phys. Fluids, vol. 26, 2488 (1983)) under a number of
analytical approximations. Here we perform a numerical investigation to examine
the stability of the model. We find that for slightly over dense plasmas, the
propagation of stable solitary modes can occur in an adiabatic regime where the
ion acoustic electric field potential is enslaved to the electromagnetic field
of a laser. But if the laser intensity or plasma density increases or the laser
frequency decreases, the adiabatic regime loses stability via a transition to
chaos. New asymptotic states are attained when the adiabatic regime no longer
exists. In these new states, the plasma becomes rarefied, and the laser field
tends to behave like a vacuum field.Comment: 19 pages, REVTeX, 6 ps figures, accepted for publication in Phys.
Rev.
Consumer Behavior Analysis and Social Marketing: The Case of Environmental Conservation
Consumer behavior analysis represents one development within the behavior-analytic tradition of interpreting complex behavior, in which a specific conceptual framework has been proposed (i.e., the Behavioral Perspective Model). According to this model, consumer behavior occurs at the intersection of a consumer-behavior setting and an individualââŹâ˘s learning history of consumption and is a function of utilitarian (mediated by the product) and informational (mediated by other persons) consequences. The model has been useful in analyses of consumersââŹâ˘ brand choice and reactions to different settings. In the present paper, the model was applied to the interpretation of environmental deleterious behaviors (use of private transportation, consumption of domestic energy, waste disposal, and domestic consumption of water). This application pointed to specific marketing strategies that should be adopted to modify each of these operant classes
Chemical and Sensorial Characterization of Tropical Syrah Wines Produced at Different Altitudes in Northeast of Brazil
Over the years, viticulture has expanded to new regions outside the temperate zones, such as Northeast Brazil, India, Thailand, Myanmar, Vietnam, Bangladesh and Venezuela, characterized by the production of tropical wines. It is important for the productive sector to comprehend the effects of grapevine interaction with the characteristics of each new region on wines composition. In this study, the composition of wines of Syrah from two regions with different altitudes in Northeast Brazil were analyzed by different methodologies to characterize chemical compounds as sugar, acids, minerals, phenolics (anthocyanins, flavonols, stilbenes and condensed tannins) and the sensory profile. The wines of the Bahia region (1100 m of altitude) obtained high concentrations for chemical parameters related to color, monomeric anthocyanins, stilbenes and monomeric and oligomeric tannins. Wines of the low altitude region, Pernambuco (350 m of altitude) were characterized by higher concentrations of flavonols (kaempferol, isorhamnetin, quercetin and rutin) and polymerized tannins. The chemical composition of wines from the two studied regions was influenced by altitude. A trend towards higher concentrations in most for phenolic compounds analyzed was observed in wines from the higher altitude region during the two years of study. Regarding the sensory profile, fruity, floral, herbaceous and empyreumatic attributes aromatic obtained highest scores in wines of the 350 m altitude region, the other attributes were dependent on the year of harvest
Interrelationships between Circular Economy and Industry 4.0: A Research Agenda for Sustainable Supply Chains
The purpose of this article is to propose a novel classification of the interrelationships between I4.0 technologies and CE principles that highlights the most conclusive findings and extant gaps in the relevant research. A Systematic Literature Review has been developed to locate, select and evaluate relevant contributions made to CE interrelationships with I4.0 technologies. Studies have
been analysed and classified according to the specific I4.0 technology and CE principle addressed (10Rs). The articles have been clustered into three main groups: (i) useful application of materials; (ii) extending the lifespan of products and their parts, and (iii) smarter product use and
manufacture. A mind map of the investigated articles has been used to establish the interrelationships between individual technologies and each CE principle at the supply chain level. Based on this classification, a focus group interview (FGI) was held with experts to dig deeper into the interrelationships between I4.0 technologies and CE principles. The FGI results have identified how each as yet unexplored I4.0 technology could be linked to each CE principle. A Fuzzy Delphi (FD) study was also applied to identify the most relevant I4.0 technologies for improving CE principles and closing gaps in the literature regarding the 10R CE principles. In addition, guidelines have been established to assist with practical applications and generate a research agenda on the interrelationships between I4.0 technologies and CE principles at the supply chain level. Implications for theory include the extension of view from the research gaps between I4.0 technologies and the 10Rs identified in the literature; also, an FGI and FD were
performed based on the detected research gaps to identify future lines of research for academics and offer useful guidance to directors and managers on I4.0 technology interrelationships for improving at least one of the 10R CE principles. The contribution to practice aims to enable managers to easily identify which technology from the I4.0 domain should be used to advance any given CE principle. Lastly, we provide useful guidance on the application of as yet-unused technologies to improve CE principles
Avaliação quĂmica e nutricional do queijo mozzarella e iogurte de leite de bĂşfala
The chemical and nutritional compositions of cheese and yogurt made from buffalo and cow milk were compared. The following conclusions were obtained: mozzarella type cheese and yogurt made from buffalo milk exhibited higher content of protein, fat, minerals, calcium and phosphorus when compared to those made from cow milk; in vitro digestibility tests of mozzarella type cheese and yogurt made from buffalo milk were similar to those of cow milk, indicantig suitable digestibility levels for human consumption.O presente trabalho teve por objetivo verificar a composição quĂmica e nutricional do queijo e iogurte elaborados com leite de bĂşfala e comparados com aqueles elaborados com leite de vaca. Dos resultados obtidos foram obtidas as seguintes conclusĂľes: o queijo tipo mozzarella e o iogurte elaborado com leite de bĂşfala apresentaram nĂveis superiores em proteĂna, gordura, cinzas, cĂĄlcio e fĂłsforo, estando relacionados com a composição quĂmica inicial do leite. Os nĂveis de digestibilidade in vitro dos queijos tipo mozzarella e iogurte de leite de bĂşfala apresentaram resultados semelhantes aos elaborados com leite de vaca, indicando nĂveis adequados de digestibilidade para consumo humano
- âŚ