103 research outputs found

    Effect of Various Levels of Forage and Form of Diet on Rumen Development and Growth in Calves

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    The effect of form of starter grain (coarse versus ground) and inclusion of various levels of hay on rumen development was evaluated. Two experiments were conducted to determine the effect of form of diet and forage inclusion on intake, growth, feed efficiency and weaning age in dairy calves. Diets consisted of commercial coarse starter (C), ground starter (G), coarse starter with 7.5% bromegrass hay of consistent particle size (8 - 19 mm) (H1), and coarse starter with 15% hay (H2). In experiment 1, intake was held constant across treatments until weaning, when feed was offered ad libitum. Calves receiving H1 and H2 were heavier, had greater body weight gain and greater feed efficiency than calves receiving C. There were no differences in intake. Total volatile fatty acid (VFA) concentrations were higher and the proportion of acetate was lower for calves fed G versus C. In experiment 2, calves (n = 56) were offered diets on an ad libitum basis and weaned according to intake. There were no differences in body weight gain, average daily gain, feed efficiency and age at weaning with respect to treatment. Starter and total dry matter intake tended to be greater in calves fed H1 and H2 versus C. Addition of controlled particle size hay to diets of young calves appears to favorably alter rumen environment resulting in increased intake and improved feed efficiency. Forage of a consistent particle size can be successfully utilized in starter rations of young calves

    Investigating the Minimal Counterintuitiveness Effect

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    Scholars believe that minimally counterintuitive concepts are more memorable than intuitive ones (Barrett, 2008; Upal 2011). If an item has an unusual or counterintuitive property, such as a ball that rises rather than falls when dropped, the unusual property makes the item more memorable. However, experiments investigating this effect tend to have experimental confounds that make interpretation difficult. Our experiment aimed to solve these problems by using counterbalanced lists of nonwords, using the nonwords to control for prior associations and experiences. Participants viewed a series of nonwords along with a noun-adjective pair (e.g. Frav – a roaring tiger) and were told that each nonword represented a name. Some nonwords were the names of an intuitive item (e.g. a roaring tiger) whereas others were counterintuitive (e.g. a writing tiger). Participants rated the likelihood that the described nonword was from Earth or from a parallel universe where things were different. Everyone was told to remember the nonwords and noun-adjective pairs for a later test. To improve overall recall, each item was presented and rated twice. After a distractor, participants were asked to recall as many of the nonwords as possible. The results revealed that counterintuitive items were not better-recalled than intuitive items. In fact, in most tests, intuitive items were recalled significantly more often than intuitive items. Our results do not support the Minimal Counterintuitiveness Effect and suggest that when to-be-remembered words and their accompanying nouns are matched across conditions (counterintuitive and intuitive), that intuitive information is more memorable than counterintuitive information

    A metalloproteomic analysis of interactions between plasma proteins and zinc: elevated fatty acid levels affect zinc distribution

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    Serum albumin is a highly abundant plasma protein associated with the transport of metal ions, pharmaceuticals, fatty acids and a variety of small molecules in the blood. Once thought of as a molecular ‘sponge’, mounting evidence suggests that the albumin-facilitated transport of chemically diverse entities is not independent. One such example is the transport of Zn2+ ions and non-esterified ‘free’ fatty acids (FFAs) by albumin, both of which bind at high affinity sites located in close proximity. Our previous research suggests that their transport in blood plasma is linked via an allosteric mechanism on serum albumin. In direct competition, albumin-bound FFAs significantly decrease the binding capacity of albumin for Zn2+, with one of the predicted consequences being a change in plasma/serum zinc speciation. Using liquid chromatography (LC), ICP-MS and fluorescence assays, our work provides a quantitative assessment of this phenomenon, and finds that in the presence of high FFA concentrations encountered in various physiological conditions, a significant proportion of albumin-bound Zn2+ is re-distributed amongst plasma/serum proteins. Using peptide mass fingerprinting and immunodetection, we identify candidate acceptor proteins for Zn2+ liberated from albumin. These include histidine-rich glycoprotein (HRG), a multifunctional protein associated with the regulation of blood coagulation, and members of the complement system involved in the innate immune response. Our findings highlight how FFA-mediated changes in extracellular metal speciation might contribute to the progression of certain pathological conditions

    Easy to synthesize, robust organo-osmium asymmetric transfer hydrogenation catalysts

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    Asymmetric transfer hydrogenation (ATH) is an important process in organic synthesis for which the Noyori-type RuII catalysts [(arene)Ru(Tsdiamine)] are now well established and widely used. We now demonstrate for the first time the catalytic activity of the osmium analogues. X-ray crystal structures of the 16-electron OsII catalysts are almost identical to those of RuII. Intriguingly the precursor complex was isolated as a dichlorido complex with a monodentate amine ligand. The OsII catalysts are readily synthesised (within 1 h) and exhibit excellent enantioselectivity in ATH reactions of ketones

    Asymmetric transfer hydrogenation by synthetic catalysts in cancer cells

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    Catalytic anticancer metallodrugs active at low doses could minimise side-effects, introduce novel mechanisms of action which combat resistance, and widen the spectrum of anticancer drug activity. We have used new highly-stable chiral half-sandwich organometallic Os(II) arene sulfonyl diamine complexes, [Os(arene)(TsDPEN)] to achieve highly enantioselective reduction of pyruvate, a key intermediate in metabolic pathways, both in aqueous model systems and in human cancer cells, using non-toxic concentrations of sodium formate as a hydride source. Importantly the catalytic mechanism generates selectivity towards ovarian cancer cells versus non-cancerous fibroblasts (both ovarian and lung), which are commonly used as models of healthy proliferating cells. The formate precursor N-formylmethionine was explored as an alternative to formate in PC3 prostate cancer cells, which are known to over-express a deformylase enzyme. Transfer hydrogenation catalysts generating reductive stress in cancer cells offer a ground-breaking new approach to cancer therapy
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