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Methodology Article: Can Ruminal Reducing Power Assessed in Batch Cultures be Comparable to in Vivo Measurements?  [PDF]
Christine Julien, Jean-Philippe Marden, Annabelle Troegeler-Meynadier, Corine Bayourthe
Journal of Analytical Sciences, Methods and Instrumentation (JASMI) , 2014, DOI: 10.4236/jasmi.2014.43011

In ruminant field of digestive research, the appeal to methods of less invasive studies and reproducing the in vivo conditions is essential. The objective of the present study was to determine whether the conditions created with the proposed in vitro batch culture was an accurate reproduction of the physico-chemical and fermentative ruminal conditions observed in vivo. Two experiments were conducted to compare ruminal reducing power measured in vitro, i.e. in batch cultures or, in vivo i.e. in live animals: dairy cows at maintenance (Experiment 1) and lactating dairy cows (Experiment 2). In Experiment 1, at the beginning of incubation period, in vitro redox potential (Eh), pH and Clark’s exponent (rH) values were significantly higher than in vivo (+42 mV, +0.25 and +1.9, respectively) whereas volatile fatty acids (VFA)

In vitro rumen feed degradability assessed with DaisyII and batch culture: effect of sample size  [cached]
Mirko Cattani,Franco Tagliapietra,Lucia Bailoni,Stefano Schiavon
Italian Journal of Animal Science , 2010, DOI: 10.4081/ijas.2009.s3.169
Abstract: In vitro degradability with DaisyII (D) equipment is commonly performed with 0.5g of feed sample into each filter bag. Literature reported that a reduction of the ratio of sample size to bag surface could facilitate the release of soluble or fine particulate. A reduction of sample size to 0.25 g could improve the correlation between the measurements provided by D and the conventional batch culture (BC). This hypothesis was screened by analysing the results of 2 trials. In trial 1, 7 feeds were incubated for 48h with rumen fluid (3 runs x 4 replications) both with D (0.5g/bag) and BC; the regressions between the mean values provided for the various feeds in each run by the 2 methods either for NDF (NDFd) and in vitro true DM (IVTDMD) degradability, had R2 of 0.75 and 0.92 and RSD of 10.9 and 4.8%, respectively. In trial 2, 4 feeds were incubated (2 runs x 8 replications) with D (0.25 g/bag) and BC; the corresponding regressions for NDFd and IVTDMD showed R2 of 0.94 and 0.98 and RSD of 3.0 and 1.3%, respectively. A sample size of 0.25 g improved the precision of the measurements obtained with D.
Digestibility and ruminal digestion kinetics of corn silage
Di Marco, O.N.;Aello, M.S.;Arias, S.;
Arquivo Brasileiro de Medicina Veterinária e Zootecnia , 2005, DOI: 10.1590/S0102-09352005000200014
Abstract: the in situ dry matter (dm) disappearance of corn silages in two maturity stages (milk grain and half milk line) of known in vivo and in vitro digestibility was determined, with the main purpose of comparing digestibility values with the ruminal disappearance at 24 and 48h of incubation. a secondary goal was the description of their ruminal digestion kinetics, from which the effective degradability was calculated at an assumed passage rate of 4%/h. data of in vivo, in vitro and in situ degradability at 24 and 48-h were analyzed with a linear model that included as fixed effects the maturity and the methodology of evaluation, and the kinetic data were described by the exponential model of mcdonald. there was a significant effect (p<0.05) of methodology in the estimation of digestibility, but not of maturity or interaction maturity × methodology. the in vivo digestibility (52.9%) was not different from the 24-h in situ degradability (55.6%) with numerical values in the range of the effective degradability. the in vitro digestibility (61.6%) was not different from the 48-h in situ degradability (61.9%), being both estimates higher than the in vivo digestibility. the 24-h in situ degradability was a closer estimator of the in vivo digestibility and the 48-h in situ degradability and the in vitro digestibility overestimated the in vivo parameter by 15-20%.
Right $P$-comparable semigroups  [PDF]
Nazer. H. Halimi
Mathematics , 2009,
Abstract: In this paper we introduce the notion of right waist and right comparizer ideals for semigroups. In particular, we study the ideal theory of semigroups containing right waists and right comparizer ideals. We also study those properties of right cones that can be carried over to right $P$-comparable semigroups. We give sufficient and necessary conditions on the set of nilpotent elements of a semigroup to be an ideal. We provide several equivalent characterizations for a right ideal being a right waist. In one of our main result we show that in a right $P_1$-comparable semigroup with left cancellation law, a prime segment $P_2\subset P_1$ is Archimedean, simple or exceptional, extending a similar result of right cones to $P$-comparable semigroups.
Comparable pairs in families of sets  [PDF]
Noga Alon,Shagnik Das,Roman Glebov,Benny Sudakov
Mathematics , 2014,
Abstract: Given a family $\mathcal{F}$ of subsets of $[n]$, we say two sets $A, B \in \mathcal{F}$ are comparable if $A \subset B$ or $B \subset A$. Sperner's celebrated theorem gives the size of the largest family without any comparable pairs. This result was later generalised by Kleitman, who gave the minimum number of comparable pairs appearing in families of a given size. In this paper we study a complementary problem posed by Erd\H{o}s and Daykin and Frankl in the early '80s. They asked for the maximum number of comparable pairs that can appear in a family of $m$ subsets of $[n]$, a quantity we denote by $c(n,m)$. We first resolve an old conjecture of Alon and Frankl, showing that $c(n,m) = o(m^2)$ when $m = n^{\omega(1)} 2^{n/2}$. We also obtain more accurate bounds for $c(n,m)$ for sparse and dense families, characterise the extremal constructions for certain values of $m$, and sharpen some other known results.
Lipid production in batch and fed-batch cultures of Rhodosporidium toruloides from 5 and 6 carbon carbohydrates
Marilyn G Wiebe, Kari Koivuranta, Merja Penttil?, Laura Ruohonen
BMC Biotechnology , 2012, DOI: 10.1186/1472-6750-12-26
Abstract: R. toruloides was grown in batch and fed-batch cultures in 0.5 L bioreactors at pH 4 in chemically defined, nitrogen restricted (C/N 40 to 100) media containing glucose, xylose, arabinose, or all three carbohydrates as carbon source. Lipid was extracted from the biomass using chloroform-methanol, measured gravimetrically and analysed by GC.Lipid production was most efficient with glucose (up to 25 g lipid L?1, 48 to 75% lipid in the biomass, at up to 0.21 g lipid L?1 h?1) as the sole carbon source, but high lipid concentrations were also produced from xylose (36 to 45% lipid in biomass). Lipid production was low (15–19% lipid in biomass) with arabinose as sole carbon source and was lower than expected (30% lipid in biomass) when glucose, xylose and arabinose were provided simultaneously. The presence of arabinose and/or xylose in the medium increased the proportion of palmitic and linoleic acid and reduced the proportion of oleic acid in the fatty acids, compared to glucose-grown cells.High cell densities were obtained in both batch (37 g?L?1, with 49% lipid in the biomass) and fed-batch (35 to 47 g?L?1, with 50 to 75% lipid in the biomass) cultures. The highest proportion of lipid in the biomass was observed in cultures given nitrogen during the batch phase but none with the feed. However, carbohydrate consumption was incomplete when the feed did not contain nitrogen and the highest total lipid and best substrate consumption were observed in cultures which received a constant low nitrogen supply.Lipid production in R. toruloides was lower from arabinose and mixed carbohydrates than from glucose or xylose. Although high biomass and lipid production were achieved in both batch and fed-batch cultures with glucose as carbon source, for lipid production from mixtures of carbohydrates fed-batch cultivation was preferable. Constant feeding was better than intermittent feeding. The feeding strategy did not affect the relative proportion of different fatty acids in the lipi
A Case for the Use of Herbal Extracts in Oral Hygiene: The Efficacy of Psidium guajava-Based Mouthwash Formulations
Charles O. Esimone,Chukwuemeka S. Nworu,Ubong S. Ekong,Ifeanyichukwu R. Iroha,Chidimma S. Okolin
Research Journal of Applied Sciences , 2012,
Abstract: Aqueous leaf extract of a tropical variety of Psidium guajava L. (Myrtaceae) was used to formulate five batches of herbal mouthwash. The antimicrobial potentials of these herbal mouthwash formulations in oral hygiene were assessed in vitro using a modification of the conventional methods for evaluating oral antiseptics. Formulations containing only Psidium guajava leaf extract and a standard mouthwash (Minty Brett) served as controls. The mouthwash formulations were screened for antimicrobial activities against cultures of Staphylococcus aureus, Escherichia coli and Candida albican. The extinction time of each formulation batch was determined against each test organism. The five batches containing Psidium guajava aqueous extract showed a high level of activity against the test organisms-E. coli and S. aureus comparable to the activity shown by the standard mouthwash, Minty Brett . The batch containing only aqueous extract of Psidium guajava had the least extinction time of 15 and 20 min against E. coli and S. aureus, respectively. The study encourages further stability and In vivo assessment to develop P. guajava leaf extract as an ingredient of commercial mouthwashes.
Regenerated extracellular NH4+ affects the motile chemosensory responses of batch-cultured Oxyrrhis marina
Martel, Claire M.;
Brazilian Journal of Microbiology , 2010, DOI: 10.1590/S1517-83822010000200010
Abstract: regenerated extracellular nh4+in laboratory batch-cultures of the heterotrophic marine microzooplankter oxyrrhis marina affects the strength and consistency of chemotaxes elicited by synthetic and biogenic chemoattractants. the ecological relevance of experiments with batch-cultured o. marina and limitations of the microcapillary assay for the study of chemosensory behaviours are discussed.
Comparisons between continuous and batch processing to produce clavulanic acid by Streptomyces clavuligerus
Baptista-Neto, álvaro;Teodoro, Juliana Concei??o;Cassiano Filho, Luiz Claudio Macedo;Badino, Alberto Colli;Hokka, Carlos Osamu;
Brazilian Archives of Biology and Technology , 2005, DOI: 10.1590/S1516-89132005000400012
Abstract: the aim of the present work was to compare ca production in continuous culture with and without cell recycling and in batch process by streptomyces clavuligerus. continuous cultivations with high cell concentration using cell recycling were performed utilizing a hollow fiber ultrafiltration module to separate cells from the filtrate broth. the continuous cultures without cell recycling and the batch cultivations were performed conventionally. the highest productivity was attained in the continuous cultivation with cell recycling (22.2 mg.l-1.h-1). the highest ca concentration was obtained in the batch process (470 mg.l-1.h-1).
Studies on Growth of Marine Microalgae in Batch Cultures: III. Nannochloropsis oculata (Eustigmatophyta)  [PDF]
B. Sen,M.A.T. Kocer,M.T. Alp,H. Erbas
Asian Journal of Plant Sciences , 2005,
Abstract: In this study, growth of Nannochloropsis oculata in batch culture was investigated in relation to some physical and chemical factors. For this purpose, batch culture of N. oculata was prepared in sea water and the cultures were kept under four combinations of light regime and carbondioxide supply. Three salinity levels, 25, 30 and 35%o S were employed. Growth of the alga in culture varied with respect to number of individuals and size of maxima under different culture conditions. N. oculata showed better growth in batch culture that was kept under 24 h illumination and 24 h of carbondioxide supply.
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