160 research outputs found
Analysis of the Equilibrium and Kinetics of the Ankyrin Repeat Protein Myotrophin
We apply the Wako-Saito-Munoz-Eaton model to the study of Myotrophin, a small
ankyrin repeat protein, whose folding equilibrium and kinetics have been
recently characterized experimentally. The model, which is a native-centric
with binary variables, provides a finer microscopic detail than the Ising
model, that has been recently applied to some different repeat proteins, while
being still amenable for an exact solution. In partial agreement with the
experiments, our results reveal a weakly three-state equilibrium and a
two-state-like kinetics of the wild type protein despite the presence of a
non-trivial free-energy profile. These features appear to be related to a
careful "design" of the free-energy landscape, so that mutations can alter this
picture, stabilizing some intermediates and changing the position of the
rate-limiting step. Also the experimental findings of two alternative pathways,
an N-terminal and a C-terminal one, are qualitatively confirmed, even if the
variations in the rates upon the experimental mutations cannot be
quantitatively reproduced. Interestingly, folding and unfolding pathway appear
to be different, even if closely related: a property that is not generally
considered in the phenomenological interpretation of the experimental data.Comment: 27 pages, 7 figure
Sistema orçamentário para um varejo de perecíveis
Independentemente do setor em que as empresas atuem, todos estão sujeitos a crises econômicas, desacelerações do crescimento e problemas decorrentes da instabilidade econômica, obrigando as empresas a estarem preparadas para os desafios do cotidiano. Diante dessa realidade foi realizado um estudo na empresa Fruteira Japonesa, na cidade de Palmeira das Missões, com o objetivo de desenvolver um sistema orçamentário, incluindo um plano estratégico, planejamento de compras, vendas, caixa, demonstração do resultado do exercício e balanço patrimonial projetado. O estudo teve características de pesquisa aplicada, descritiva, documental, qualitativa e observação participativa. A aplicabilidade do sistema orçamentário realizado na empresa teve relevante importância para seu planejamento e desenvolvimento, tendo êxito em seus objetivos e projetando uma situação financeira futura. AbstractIndependently of the sector in which company operates, all are subject to economic crisis, growth slowdowns and problems arising from economic instability, forcing companies to be prepared for the challenges of everyday. Against this reality a research was realized at Fruteira Japonesa, at the city of Palmeira das Missões, that aims the development of a budget system, including a strategic plan, planning of purchases, sales, cash, statement of income and balance sheet designed. This paper had characteristics of applied research, descriptive, documental, qualitative and participatory observation. The applicability of the budget system held in the company had considerable importance for planning and development, succeeding in their goals and projecting a future financial situation
Effects of different diet alternatives to replace the use of pharmacological levels of zinc on growth performance and fecal dry matter of weanling pigs
A total of 300 weanling pigs (Line 400 × 200, DNA, Columbus, NE, initially 4.83 kg) were used in a 46-d trial to evaluate the effects of different nutritional strategies to replace pharmacological levels of Zn, provided by zinc oxide (ZnO), in nursery diets on growth performance and fecal dry matter (DM). Six treatments with 10 replicate pens per treatment and 5 pigs per pen were used. Diets consisted of: (1) positive control (ZnO providing 3,000 mg/kg added Zn from d 0 to 7 and 2,000 mg/kg added Zn from d 8 to 25 and 21% crude protein, CP); (2) negative control (NC; no added ZnO); (3) NC plus 1.2% Na diformate; (4) NC with 4% coarse ground wheat bran; (5) NC but formulated to 18% CP; and (6) the combination of NC with 18% CP, 1.2% Na diformate, and 4% coarse ground wheat bran. The diets formulated to 18% CP contained 1.2% standardized ileal digestible (SID) Lys from d 0 to 25, whereas the 21% CP diets contained 1.4% SID Lys from d 0 to 7 and 1.35% SID Lys from d 7 to 25. From d 25 to 46, all pigs were fed a common diet. From d 0 to 7, no differences in any variables were observed between treatments. From d 7 to 25, pigs fed the diet with added ZnO had greater (P < 0.01) average daily gain (ADG) and average daily feed intake (ADFI) than all other treatments. Pigs fed the diet formulated to 18% CP had decreased (P < 0.01) ADG when compared with pigs fed the other diets. From d 25 to 46, no previous treatment effects on ADG or gain to feed ratio (G:F) were observed. Overall (d 0 to 46), pigs fed the diet with added ZnO from d 0 to 25 had greater (P < 0.01) ADG, ADFI, and final body weight than pigs fed added Na Diformate, or 4% coarse ground wheat bran, or with the 18% CP diet, or with pigs fed the combination of the additives intermediate. There was no evidence for differences in overall G:F. Pigs fed the NC diet had the lowest fecal DM and highest fecal scores (P < 0.05), indicating the greatest incidence of loose stools. Pigs fed added ZnO had greater fecal DM than pigs fed the NC, 4% added wheat bran, or 18% CP diets, or with pigs fed the combination of additives intermediate (P < 0.01). These results suggest that adding pharmacological levels of Zn from ZnO improves nursery pig performance and increases DM content of feces when compared with pigs fed diets with either Na diformate, 4% course wheat bran, or 18% CP alone. However, a combination of all three alternatives appeared to be additive and partially restored growth performance similar to adding pharmacological levels of Zn
Effects of Weaning Age and Antibiotic Use on Pig Performance in a Commercial System
A total of 2,184 barrows and gilts (DNA 600 × PIC L42) were used in a study from weaning to market to evaluate the effect of increasing weaning age and antibiotic use on pig performance in a commercial production system. A 3 × 2 factorial arrangement was used. The treatments included weaning age (18.5, 21.5, or 24.5 days of age) and the use of antibiotic (AB) or antibiotic free (ABF). There were 14 replicate pens per treatment and 26 pigs per pen (13 barrows and 13 gilts). Pigs were weaned from a 4,000-sow farm and placed in pens by weaning age with pens randomly assigned to AB or ABF. Pigs assigned to AB had access to a diet containing 400 ppm of chlortetracycline (CTC) from d 8 to 21 post-weaning, and after a porcine respiratory and reproductive syndrome (PRRS) outbreak at week 7 post-weaning, they were medicated via drinking water for five consecutive days with CTC (10 mg/lb of body weight (BW) per day). For the first 42 days post-weaning, increasing weaning age reduced the number of pigs treated with injectable antibiotic (quadratic, P = 0.004), but AB use did not influence this variable (P = 0.626). Each additional day of weaning age resulted in greater BW at weaning and at 197 days of age with slopes of 0.484 lb and 1.485 lb, respectively (linear, P \u3c 0.001). From weaning to 197 days of age, increasing weaning age increased average daily gain (0.02 lb/day of weaning age; linear, P \u3c 0.001) and the same effect was found for AB (0.03 lb/d; P = 0.009). Weaning age and AB also affected average daily feed intake (0.03 lb/day of increase in weaning age; linear, P \u3c 0.001 and 0.08 lb/d; P = 0.031, respectively). An interaction (linear, P = 0.005) was found for feed efficiency. When AB were fed, pigs weaned at 21.5 and 24.5 d were less efficient. However, AB improved feed efficiency of pigs weaned at 18.5 d. Pigs with access to AB in feed and water had lower total losses (2.7% less mortality + removal; P \u3c 0.001). Increasing weaning age also marginally decreased total losses (-0.21% per day increase in weaning age; linear, P = 0.097). The weight sold (at 197 d of age) per pig weaned was increased by increasing weaning age (an additional 1.55 lb for each day increase in weaning age; linear, P = 0.050) and by using AB in feed and water (an addition of 10.1 lb/pig; P = 0.019). In summary, increasing weaning age linearly improved pig performance and relatively short-term use of antibiotics reduced mortality and removals. In addition, both factors contributed to maximizing the weight sold per pig weaned
West Nile virus transmission. results from the integrated surveillance system in Italy, 2008 to 2015
IIn Italy a national Plan for the surveillance of imported and autochthonous human vector-borne diseases (chikungunya, dengue, Zika virus disease and West Nile virus (WNV) disease) that integrates human and veterinary (animals and vectors) surveillance, is issued and revised annually according with the observed epidemiological changes. Here we describe results of the WNV integrated veterinary and human surveillance systems in Italy from 2008 to 2015. A real time data exchange protocol is in place between the surveillance systems to rapidly identify occurrence of human and animal cases and to define and update the map of affected areas i.e. provinces during the vector activity period from June to October. WNV continues to cause severe illnesses in Italy during every transmission season, albeit cases are sporadic and the epidemiology varies by virus lineage and geographic area. The integration of surveillance activities and a multidisciplinary approach made it possible and have been fundamental in supporting implementation of and/or strengthening preventive measures aimed at reducing the risk of transmission of WNV trough blood, tissues and organ donation and to implementing further measures for vector control
Isotopic exchange processes in cold plasmas of H2/D2 mixtures
12 páginas, 3 tablas, 10 figuras.-Isotope exchange in low pressure cold plasmas of H2/D2 mixtures has been investigated by means of mass spectrometric measurements of neutrals and ions, and kinetic model calculations.
The measurements, which include also electron temperatures and densities, were performed in a stainless steel hollow cathode reactor for three discharge pressures: 1, 2 and 8 Pa, and for mixture
compositions ranging from 100% H2 to 100% D2. The data are analyzed in the light of the model calculations, which are in good global agreement with the experiments. Isotope selective effects are found both in the surface recombination and in the gas-phase ionic chemistry.
The dissociation of the fuel gas molecules is followed by wall recycling, which regenerates H2 and D2 and produces HD. Atomic recombination at the wall is found to proceed through an Eley–Rideal mechanism, with a preference for reaction of the adsorbed atoms with gas phase D atoms. The best fit probabilities for Eley–Rideal abstraction with H and D are:gER H = 1.5 x 10-3, gER D = 2.0 x 10-3. Concerning ions, at 1 Pa the diatomic species H2+,D2+ and HD+, formed directly by electron impact, prevail in the distributions, and at 8 Pa, the triatomic ions H3+, H2D+, HD2+ and D3+, produced primarily in reactions of diatomic ions with molecules, dominate the plasma composition. In this higher pressure regime, the formation of the mixed ions H2D+ and HD2
+ is favoured in comparison with that of H3
+ and D3+, as expected on statistical grounds. The model results predict a very small preference, undetectable within the precision of the measurements, for the generation of triatomic ions with a higher degree of deuteration, which is probably a residual influence at room temperature of the marked zero point energy effects (ZPE), relevant for deuterium fractionation in interstellar space. In contrast,ZPE effects are found to be decisive for the observed distribution of monoatomic ions H+ and D+,
even at room temperature. The final H+/D+ ratio is determined to a great extent by proton (and deuteron) exchange, which favours the enhancement of H+ and the concomitant decrease of D+.This work has been funded by the MICINN of Spain under projects FIS 2007-61686, FIS2010-16455 and CSD2009-00038.
EC acknowledges also funding from the JdC program of the MICINN.Peer reviewe
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