Internal quality of commercial eggs stored under conditions that simulate storage from laying to consumption

This study evaluated the effects on the internal quality of eggs of various storage environments through which eggs may pass between being laid and being consumed. Commercial eggs (N = 648) from Dekalb White hens were used. Treatments consisted of T1: 28 days at 4 °C; T2: 28 days at 20 °C; T3: 7 days at room temperature (27 °C ± 2 °C) (humidity 55%) and 21 days at 4 °C; T4: 7 days at room temperature and 21 days at 20 °C; T5: 14 days at room temperature and 14 days at 4 °C; T6: 14 days at room temperature and 14 days at 20 °C; T7: 21 days at room temperature and 7 days at 4 °C; T8: 21 days at room temperature and 7 days at 20 °C; and T9: 28 days at room temperature. The characteristics that were evaluated consisted of Haugh unit (HU), yolk index (YI), colour (L*, a* and b*), albumen pH, yolk pH and lipid oxidation. Eggs stored 28 days were darker (L*), and had greater yolk pH and lipid oxidation than fresh eggs. Eggs stored under T1 and T3 conditions had greater HU and YI than eggs stored in the other environments. The albumin pH of eggs stored at room temperature (T9) was highest of the treatments. Yellowness was increased in eggs stored under T4, T6, T8, and T9 conditions. Eggs should be stored under refrigeration as this promotes maintenance of internal quality and mitigates negative effects of previous storage conditions

Solubilidade de calcários em extratores químicos

The solubility of four limestones (sedimentar and methamorfic) separated in four granulometric fractions were studied using two chemical extractants (solutions of hydrochloric and acetic acids), under different conditions, with the objective of evaluating the efficiency of these materials by means of that criterion. The results, compared with others obtained by incubation with soils, showed that the chemical extractants can not be used to evaluate the agricultural limestones because there was no correlation between solubility, expressed in terms of equivalent of CaCO3, and the efficiency showed in the soil incubation study.A solubilidade de quatro calcários agrícolas, dois sedimentares e dois metamórficos, divididos em quatro frações granulométricas, foi estudada em dois extratores químicos (soluções de ácido clorídrico e de ácido acético), em variadas condições, com o objetivo de avaliar a eficiência desses materiais através desse critério. Os resultados obtidos, comparados com os ensaios de incubação com solos, mostraram que para a pretendida avaliação, os extratores não se prestam para avaliar os calcários agrícolas, visto que não há correlação entre a solubilidade, expressa em equivalente de CaCO3, e a eficiência mostrada nos ensaios de incubação com solos

Reatividade de calcários agrícolas e a relação entre os teores de cálcio e magnésio

A reatividade da fração retida entre as peneiras nºs 50-60 (ABNT) de quatro calcários, com teores relativos de óxidos de cálcio decrescentes e de óxidos de magnésio crescentes, foi avaliada incubando-os , durante 100 dias, com três solos diferentes. O delineamento foi o de blocos casualizados com 6 tratamentos e 4 repetições. A avaliação, feita através das variações periódicas do pH e dos teores de alumínio, cálcio e magnésio trocáveis, mostrou que a relação entre os teores de cálcio e magnésio nos calcários não influi na sua reatividade, tanto quanto à correção da acidez dos solos como ao fornecimento de cálcio e de magnésio.The reactivity of four limestones with increasing CaO and decreasing MgO contents was evaluated by incubating the limestones with three different soils. The results showed that the reactivity of the limestones in neutralizing soil acidity was not influenced by its carbonate forms, that is, calcium or magnesium

Avaliação da qualidade de calcários agrícolas através do PRNT

Agricultural limestones of various PRNT (Relative Power of Total Neutralization) values, calculated considering the relative efficiency of their granulometric fractions, were used in a comparative study. A number of 22 limestone samples were collected ; 12 from different mills from the municipalities of Rio Claro, Piracicaba and Tietê and 10 selected to obtain a desired range of granulometric and chemical composition in the lot. The results indicate that PRNT formulas currently used in Brazil may be underestimating limestone efficiency. The proposed new formula can be taken as a more reliable index for agricultural purposes.Foram comparados os valores do PRNT de calcários agrícolas, empregando fórmulas que se baseiam em diferentes valores de eficiência relativa das frações granulométricas que compõem esses materiais. Foram utilizadas 22 amostras de calcários, sendo 12 de Rio Claro, Piracicaba e Tietê, Estado de São Paulo e as demais especialmente escolhidas visando variação nas composições granulométrica e química. Os resultados sugerem que as fórmulas de PRNT que têm sido utilizadas no Brasil , devem estar substimando a eficiência desses produtos , além de carecerem de um respaldo experimental mais convincente. A nova fórmula proposta pode ser mais confiável, apesar de estar também sujeita a várias críticas

Eficiência relativa de diferentes frações granulometricas de calcários na neutralização da acidez dos solos, avaliada em laboratório

Two sedimentar and two metamorphic limestone, separated in the sieves n°s (ABNT) 5-10, 10-30, 30-50, and 50-60 were incubated with three types of soils. The neutralizing efficiency was evaluated by pH variation. The results showed that their efficiency is independent of the geological nature of limestone but is dependent of soil type. The following efficiency value is suggested for each size fraction: larges than size 10 is 0%, size 10-30 is 35%, sizes 30-50 is 75% and smaller than size 50 is 100%.As frações granulométricas retidas nas peneiras n°s (ABNT) 5-10, 10-30, 30-50, e 50-60 de quatro calcários, sendo dois sedimentares e dois metamórficos, foram incubadas durante 160 dias com três tipos de solos, em condições de laboratório. A eficiência das frações na neutralização da acidez dos solos foi avaliada pela variação do pH. Os resultados permitiram concluir que a referida eficiência independe da natureza geológica do calcário mas depende do tipo de solo, sendo decrescente na seguinte ordem: LVd, LEd e LEm. Apesar da legislação atual normatizar as características físicas dos calcários, bem como os seus graus de eficiência, a presente pesquisa sugere novos valores para a eficiência relativa das diferentes frações granulometricas de calcários: fração maior do que 10:0%, de 30:35%; de 30-50:75% e menor que 50:100%

Importância da reatividade do calcário sobre a produção e algumas característica da cultura da soja

This experiment was conducted on a dark-red latosol, medium textured, Jaboticabal-SP, Brazil. The main objective was to study the effect of two liming materials (dolomitic and calcined-dolimitic), with four grades of particle size (F1 = >; 2mm; F2 = 2-0,84 mm; F3 = 0,84-0,30mm and F4 = ; 0.05). Only the contents of Mg in the leaves and grains differed among treatments.O experimento foi conduzido num latossolo vermelho escuro, textura média, localizado em Jaboticabal-SP, para se estudar o efeito de dois calcários (dolomítico e dolomítico calcinado), com quatro graus de finuras (F1 = >; 2mm; F2 = 2-0,84 mm; F3 = 0,84-0,30mm e F4 = < 0,30mm), sobre propriedades químicas desse solo durante dois anos agrícolas (1988/89 e 89/90) e em características agronômicas da soja cv. IAC-8. Concluiu-se que: no 1&deg; ano agrícola (88/89) o calcário calcinado foi mais reativo, bem como as granulometrias mais finas, sendo que a produção de grãos aumentou em 14%; no 2&deg; ano (89/90), os calcários e as finuras tenderam a igualar seus efeitos e a produção de grãos não foi alterada; para as análises foliares e de grãos, somente houve efeito para o Mg

Susceptibilidade antimicrobiana de cepas de estafilococcos coagulase-negativa isolados de ovinos de corte com mastite

Avaliou-se a sensibilidade antimicrobiana in vitro de 121 cepas de estafilococos coagulase-negativa isolada de leite de ovelhas Santa Inês, aos fármacos: penicilina, amoxicilina, ampicilina, estreptomicina, oxaciclina, neomicina, cefalotina, gentamicina e sulfonamida. A resistência à sulfonamida foi a mais frequente (27,3%), seguida pela estreptomicina (14,0%) e pela oxaciclina (14,0%), enquanto da gentamicina (1,6%) foi a menos frequente. Todas as cepas foram sensíveis a pelo menos um antimicrobiano, e 20,3% das cepas apresentaram resistência múltipla. Os resultados mostram a importância de Staphylococci coagulase-negativas como agentes causadores de mastite em ovinos, e o perfil de resistência múltipla indica a importância da determinação da resistência à oxaciclina como indicador da presença de ilhas de patogenicidade que contêm fatores de virulência e resistência a outros antimicrobianos que contribuem para a sobrevivência da bactéria ao tratamento.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Semen collection using electroejaculation and sperm parameters in pacas (Cuniculus paca, Linnaeus, 1766)

ABSTRACT Pacas (Cuniculus paca) are highly hunted animals because of the flavor of their meat, and commercial breeding is recommended. However, this species has a relatively low reproductive rate. This study aimed to collect semen from pacas through electroejaculation and obtain the sperm parameters of this species for the first time. Seven male pacas were used, submitted to an anesthetic protocol before stimulation by an electroejaculator appropriate for the species. The stimulus protocol was performed in three series: series I, 10 stimuli with 1 and 2 V; series II, 10 stimuli with 3 and 4 V; and series III, 10 stimuli with 5 V and interval between series of 2 s. The collected material was evaluated for color, volume, motility, vigor, and concentration. The sperm parameters collected showed a mean volume of 0.43±0.33 mL, concentration of 45.5±42.44×106 sperm/mL, motility of 33.33±32.14%, and mean vigor of 2.6±1.15. In this study, the anesthetic protocol did not seem to favor semen collection by electroejaculation in the pacas. The electrical stimulation protocol was able to stimulate all animals in the study; however, there were few samples with sperm cells and a low rate of motility and vigor in most ejaculates

Theory of Disordered Itinerant Ferromagnets I: Metallic Phase

A comprehensive theory for electronic transport in itinerant ferromagnets is developed. We first show that the Q-field theory used previously to describe a disordered Fermi liquid also has a saddle-point solution that describes a ferromagnet in a disordered Stoner approximation. We calculate transport coefficients and thermodynamic susceptibilities by expanding about the saddle point to Gaussian order. At this level, the theory generalizes previous RPA-type theories by including quenched disorder. We then study soft-mode effects in the ferromagnetic state in a one-loop approximation. In three-dimensions, we find that the spin waves induce a square-root frequency dependence of the conductivity, but not of the density of states, that is qualitatively the same as the usual weak-localization effect induced by the diffusive soft modes. In contrast to the weak-localization anomaly, this effect persists also at nonzero temperatures. In two-dimensions, however, the spin waves do not lead to a logarithmic frequency dependence. This explains experimental observations in thin ferromagnetic films, and it provides a basis for the construction of a simple effective field theory for the transition from a ferromagnetic metal to a ferromagnetic insulator.Comment: 15pp., REVTeX, 2 eps figs, final version as publishe

Constitutive expression of the α10 nicotinic acetylcholine receptor subunit fails to maintain cholinergic responses in inner hair cells after the onset of hearing

Efferent inhibition of cochlear hair cells is mediated by α9α10 nicotinic cholinergic receptors (nAChRs) functionally coupled to calcium-activated, small conductance (SK2) potassium channels. Before the onset of hearing, efferent fibers transiently make functional cholinergic synapses with inner hair cells (IHCs). The retraction of these fibers after the onset of hearing correlates with the cessation of transcription of the Chrna10 (but not the Chrna9) gene in IHCs. To further analyze this developmental change, we generated a transgenic mice whose IHCs constitutively express α10 into adulthood by expressing the α10 cDNA under the control of the Pou4f3 gene promoter. In situ hybridization showed that the α10 mRNA is expressed in IHCs of 8-week-old transgenic mice, but not in wild-type mice. Moreover, this mRNA is translated into a functional protein, since IHCs from P8-P10 α10 transgenic mice backcrossed to a Chrna10 -/- background (whose IHCs have no cholinergic function) displayed normal synaptic and acetylcholine (ACh)-evoked currents in patch-clamp recordings. Thus, the α10 transgene restored nAChR function. However, in the α10 transgenic mice, no synaptic or ACh-evoked currents were observed in P16-18 IHCs, indicating developmental down-regulation of functional nAChRs after the onset of hearing, as normally observed in wild-type mice. The lack of functional ACh currents correlated with the lack of SK2 currents. These results indicate that multiple features of the efferent postsynaptic complex to IHCs, in addition to the nAChR subunits, are down-regulated in synchrony after the onset of hearing, leading to lack of responses to ACh. © 2009 Association for Research in Otolaryngology.Fil:Taranda, J. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Ballestero, J.A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Wedemeyer, C. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Gómez-Casati, M.E. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Lipovsek, M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Katz, E. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina