Artificial induction of lactation in cattle Indução artificial de lactação em bovinos

Forty Holstein cows, with previous reproductive problems, empty, at second or more lactations, with an average milk production of 9,200 kg in the previous lactation and a dry period over than 50 days were distruibuted in two groups to evaluate two protocols of milking induction. It was given to group 1, on days one, eight and 21 recombinant bovine somatotropin-bSTr (500 mg); from day two to eight, estradiol cypionate (0.075 mg/kg BW) and medroxi progesterone acetate (0.25 mg/kg BW); from days nine to 15, estradiol cypionate (0.037 mg/kg BW); on day 19, prostaglandin F2&#945; (0.530 mg) and from days 19 to 21, isoflupredone acetate (0.05 mg/kg BW). Group two was given, on days one, eight and 21, bSTr (500 mg), from days 2 to 15, estradiol benzoate (0.071 mg/kg BW), from days two to eight, acetate of medroxi progesterone (0.25 mg/kg BW), day 19, prostaglandin F2&#945;(0.530 mg) and from days 19 to 21 isoflupredone acetate, (0.05 mg/kg BW). Teats and udders of all cows were massaged for five minutes from day 17 to 21. Milking were carried out from the 22nd day of induction. After beginning of lactation, both groups were given bsTr (500 mg) every 14 days. It was used a complete random design with 20 replicates per treatment and a split-plot scheme. Evaluation of the protocols was carried out by using analyses of variance using Fisher´s test at 5% and production of milking per day using regression analyses. Milking was successfully induced in 85% of the animals. Animals from group 2 showed production mean 21.9 ± 12.9 kg of milk/day which was higher than group 1 mean 18.9 ± 11.5 kg of milk/day. There was no difference for milk composition in either groups. Twenty-nine cows were inseminated and 41.1% became pregnant.<br>Quarenta vacas holandesas, com problemas reprodutivos prévios, vazias, de segunda ou mais lactações, com produção média de 9.200 kg na lactação anterior, e período seco superior a 50 dias foram distribuídas em dois grupos para avaliar dois protocolos de indução da lactação. O grupo 1 recebeu nos dias um, oito e 21 somatotropina bovina recombinante - bSTr (500 mg); nos dias dois a oito cipionato de estradiol (0,075 mg/kg PV) e acetato de medroxi progesterona (0,25 mg/kg PV), do dia nove ao 15 cipionato de estradiol (0,037 mg/kg PV); no dia 19 prostaglandina F2&#945; (0,530 mg) e dias 19 a 21 acetato de isoflupredona (0,05 mg/kg PV). O grupo 2 recebeu, nos dias um, oito e 21 bSTr (500 mg), nos dias dois a 15 benzoato de estradiol (0,071 mg/kg PV), do dia dois ao oito acetato de medroxi progesterona (0,25 mg/kg PV), no dia 19 prostaglandina F2&#945; (0,530 mg), e dias 19 a 21 acetato de isoflupredona (0,05 mg/kg PV). Todos os animais tiveram o úbere e tetos massageados do dia 17 a 21 por cinco minutos. As ordenhas foram realizadas a partir do 22º dia da indução. Após o início da lactação, os dois grupos receberam bSTr (500 mg) a cada 14 dias. Utilizou-se delineamento inteiramente ao acaso, com 20 repetições por tratamento e arranjo em parcelas subdivididas. A avaliação dos protocolos foi realizada por análise de variância utilizando-se o teste de Fisher a 5% e a produção por dia de lactação por análise de regressão. A lactação foi induzida com sucesso em 85% dos animais. Os animais do grupo 2 apresentaram média de produção de 21,9 ± 12,9 kg leite/dia sendo superior a média do grupo 1 de 18,9 ± 11,5 kg leite/dia. Não houve diferença quanto à composição do leite nos dois grupos. Vinte e nove vacas foram inseminadas, destas 41,1% ficaram gestantes

Self-assembled circuit patterns

Abstract. Self-assembly is a process in which basic units aggregate under attractive forces to form larger compound structures. Recent theoretical work has shown that pseudo-crystalline self-assembly can be algorithmic, in the sense that complex logic can be programmed into the growth process [26]. This theoretical work builds on the theory of twodimensional tilings [8], using rigid square tiles called Wang tiles [24] for the basic units of self-assembly, and leads to Turing-universal models such as the Tile Assembly Model [28]. Using the Tile Assembly Model, we show how algorithmic self-assembly can be exploited for fabrication tasks such as constructing the patterns that define certain digital circuits, including demultiplexers, RAM arrays, pseudowavelet transforms, and Hadamard transforms. Since DNA self-assembly appears to be promising for implementing the arbitrary Wang tiles [30, 13] needed for programming in the Tile Assembly Model, algorithmic self-assembly methods such as those presented in this paper may eventually become a viable method of arranging molecular electronic components [18], such as carbon nanotubes [10, 1], into molecular-scale circuits.