Formation of Liesegang patterns: Simulations using a kinetic Ising model

A kinetic Ising model description of Liesegang phenomena is studied using Monte Carlo simulations. The model takes into account thermal fluctuations, contains noise in the chemical reactions, and its control parameters are experimentally accessible. We find that noisy, irregular precipitation takes place in dimension d=2 while, depending on the values of the control parameters, either irregular patterns or precipitation bands satisfying the regular spacing law emerge in d=3.Comment: 7 pages, 8 ps figures, RevTe

Anaerobic fermentation of rice bran with rumen liquor for reducing their fiber components to use as chicken feed

Rice bran is a very cheap and abundant agricultural by-products in rice producing countries. Additionally, many developing countries used these by products as poultry feed. Rice bran (RB) contains high fiber and chicken is not capable to digest those fibrous feed effectively, resulting in low production performance. The main objectives of this study were to decrease fiber components of RB through fermentation by adding rumen liquor to increase their utilization efficacy in chicken. A single-step fermentation of RB was conducted for 12 h (n=6) under anaerobic conditions, maintaining proper temperature and ideal pH. Rice bran, buffer substances, and rumen liquor were mixed at the ratio of 1:2:3, respectively. The fresh and fermented rice brans were examined for the content of acid detergent fiber (ADF), crude fiber (CF), dry matter (DM), crude protein (CP), neutral detergent fiber (NDF) and acid detergent lignin (ADL). Other fiber components were determined by substracting the value of ADL from ADF (celluloses) and ADF from NDF (hemicelluloses), respectively. One-way analysis of variance was done to compare the mean nutrient components followed by Tukey’s multiple comparison tests at P<0.05. The pH of fermented brans were decreased with growing fermentation period but appropriate pH was maintained due to the developed protocol. After fermentation, the fiber components of RB were reduced significantly (P<0.05). However, CP component was not altered significantly after the fermentation of brans. The NDF, ADF, cellulose, hemicellulose contents were reduced by 16.2±0.52, 7.2±0.32, 20.0±0.38 and 23.6±0.54%, respectively compared to the fresh brans. As the fiber content reduced significantly after fermentation that clearly, increases the usability of brans as chicken feed

Das Dietary Cation-Anion Difference (DCAD)-Konzept bei der Milchkuh

Der Dietary Cation-Anion Difference (DCAD) -Wert gibt das Verhältnis zwischen Kationen und Anionen einer Ration wieder. Es wird als Milliäquivalenten (mEq) von (Na+ + K+)-(Cl- + S2-) pro Kilogram Trockensubstanz definiert (Block, 1984) und übt einen Effekt auf den Säure-Base-Haushalt aus. Das DCAD-Konzept ist auf der „Strong Ion Difference“ Theorie (Stewart, 1983) basiert. Der DCAD-Wert einer Ration gibt an, in welcher Richtung sich der Säure-Basen-Haushalt (SHB) verschiebt. Rationen mit einem Kationenüberschuss haben einen positiven DCAD-Wert und führen zu einer basischen Stoffwechsellage. Anionen haben eine ansäuernde Wirkung und führen bei Überschuss in der Ration zu einer metabolischen Azidose. Beide Stoffwechsellagen können in den meisten Fällen durch die Homöstase kompensiert werden

Phase separation of binary fluids with dynamic temperature

Phase separation of binary fluids quenched by contact with cold external walls is considered. Navier-Stokes, convection-diffusion, and energy equations are solved by lattice Boltzmann method coupled with finite-difference schemes. At high viscosity, different morphologies are observed by varying the thermal diffusivity. In the range of thermal diffusivities with domains growing parallel to the walls, temperature and phase separation fronts propagate towards the inner of the system with power-law behavior. At low viscosity hydrodynamics favors rounded shapes, and complex patterns with different lengthscales appear. Off-symmetrical systems behave similarly but with more ordered configurations.Comment: Accepted for publication in Phys. Rev. E, 11 figures, best quality figures available on reques

Description of Molecular Distortions: IV. Relationships Between the Distortion and the Hydrogen Bond Strength for Some Compounds Containing HSO4 Ions

Several methods are known for describing the distortions of tetrahedral molecules. In the present paper, some correlations between the hydrogen bond strength and the different measures for the distortions of HS04~ ions are evaluated. In terms of the distortion indices the rasults reflect similar trends to those calculated for phosphates1. It is found that weaker hydrogen bonding as accompanied by larger distortions of the HS04 tetrahedra

Effects of EDTA-Induced Hypocalcaemia and Stress on Plasma TNF-α, IL-1-ra, G-CSF, GM-CSF and S-100 in Dairy Cows

The pathophysiology of postparturient paresis is still not completely understood. Knowledge recently acquired in immunology, endocrinology and cell physiology has still to be integrated in order to elucidate the aetiopathogenesis of the disease. For that purpose, the effect of the EDTA infusion model on the plasma concentrations of selected cytokines and growth factors, and of a calcium binding protein was examined in dairy cows. Six 6- to 11-year-old Brown Swiss cows in mid lactation were infused with a 5% solution of Na2EDTA in one jugular vein over a period of 5 h. Blood samples were collected from the contralateral side daily two days before, and then hourly for five hours during the infusion, hourly for five hours after the end of the infusion, and once daily for 10 days thereafter. The plasma concentrations of cortisol, tumour necrosis factor-α, interleukin-1 receptor antagonist, granulocyte colony-stimulating factor, granulocyte and macrophage colony-stimulating factor, and the calcium binding protein S-100 were determined. Before the EDTA infusion, during the infusion and for two days thereafter, the mean plasma concentrations of cortisol were significantly higher than those from days 4 to 10 after the infusion. The plasma concentrations of tumour necrosis factor-α and interleukin-1 receptor antagonist followed a similar profile. At the end of EDTA infusion, low concentrations of granulocyte colony-stimulating factor were detected in one cow only. On days 3 and 4, the mean plasma concentrations of granulocyte colony-stimulating factor were significantly higher than the pre-infusion values, but this was followed by a significant decrease on post-infusion day 5. From day 4 to 7, the plasma concentrations of S-100 were significantly lower than the pre-infusion values. The importance of these findings in the pathophysiology of postparturient paresis remains to be establishe

Vitamin D receptor distribution in intestines of domesticated sheep Ovis ammon f. aries

The biologically active form of vitamin D, i.e., 1,25-dihydroxycholecalciferol or calcitriol, plays an important role in bone metabolism and calcium homeostasis, which is often disturbed at the onset of lactation in high milk-yielding domestic ruminants. Gene transcription is modulated via vitamin D receptors, but nongenomic effects of vitamin D via membrane receptors have also been described. In the intestines, vitamin D promotes calcium absorption via vitamin D receptors. Vitamin D receptors are of clinical relevance, but have not been systematically assessed within all segments of the intestine in any species. Thus, we present for the first time an immunohistochemical study of the distribution patterns of the vitamin D receptor protein in sheep, which may be the basis for present and future investigations on mineral homeostasis in domestic ruminants. Tissue probes of the intestines were collected from five lambs and five nonlactating and nonpregnant dams, fixed in formalin, embedded in paraffin, and used for the assessment of vitamin D receptor protein. Nuclear vitamin D receptor immunoreaction was scored semiquantitatively and exhibited a segment-specific distribution pattern. Goblet cells always were devoid of any vitamin D receptor immunoreaction. Surface epithelial cells and enterocytes of the crypt openings generally demonstrated only a weak immunoreaction. Basally and/or intermediately located crypt epithelial cells exhibited stronger immunoreactions in duodenum, jejunum, and colon descendens. This basal/intermediate to superficial gradient was most pronounced in the duodenum and less evident in jejunum and colon descendens and not observed in ileum and cecum. There were no age-dependent variations in vitamin D receptor protein expression. Results demonstrate that intestinal vitamin D receptor distribution patterns are segment-specific and strongest immunoreactions correlate with highest intestinal calcium absorptive activities, as reported in literature. Strong expression of vitamin D receptors within the lower half of crypts also suggests a role for calcitriol in epithelial differentiation and cellular homeostasis

Method development to reduce the fiber content of wheat bran and rice bran through anaerobic fermentation with rumen liquor for use in poultry feed

Objective Wheat bran (WB) and rice bran (RB) are the agricultural by-products used as poultry feed in many developing countries. However, their use for poultry feed is limited due to high fiber and the presence of anti-nutritional substances (e.g. β-glucans). The objective of this study was to develop a method to improve the quality of those brans by reducing the fiber content. Methods A two-step fermentation method was developed where the second fermentation of first fermented dry bran was carried out. Fermentation was performed at a controlled environment for 3 h and 6 h (n = 6). The composition of brans, buffer solution and rumen liquor was maintained in a ratio of 1:2:3, respectively. Brans were analyzed for dry matter, crude fiber (CF), acid detergent fiber (ADF), neutral detergent fiber (NDF), and acid detergent lignin (ADL) content. Celluloses and hemicelluloses were calculated from the difference of ADF-ADL and NDF-ADF, respectively. Samples were compared by two-factor analysis of variance followed by Tukey’s multiple comparison tests (p<0.05). Results CF %, ADF % and cellulose tended to decrease and NDF % and hemicellulose content was reduced significantly (p<0.05). After the 1st fermentation step, NDF decreased 10.7%± 0.55% after 3 h vs 17.0%±0.78% after 6 h in case of WB. Whereas, these values were 2.3%± 0.30% (3 h) and 7.5%±0.69% (6 h) in case of RB. However, after the 2nd fermentation step, the decrease in the NDF content amounted to 9.1%±0.72% (3 h), 17.4%±1.13% (6 h) and 9.3%±0.46% (3 h), 10.0%±0.68% (6 h) in WB and RB, respectively. Cellulose and hemicellulose content was reduced up to 15.6%±0.85% (WB), 15.8%±2.20% (RB) and 36.6%±2.42% (WB), 15.9%±3.53% (RB), respectively after 2nd fermentation of 6 h. Conclusion Two-step fermentation process improved the quality of the brans for their use in poultry feed

Liesegang patterns: Effect of dissociation of the invading electrolyte

The effect of dissociation of the invading electrolyte on the formation of Liesegang bands is investigated. We find, using organic compounds with known dissociation constants, that the spacing coefficient, 1+p, that characterizes the position of the n-th band as x_n ~ (1+p)^n, decreases with increasing dissociation constant, K_d. Theoretical arguments are developed to explain these experimental findings and to calculate explicitly the K_d dependence of 1+p.Comment: RevTex, 8 pages, 3 eps figure