Reconstruction of nuclear transfer embryos in goats and cattle [electronic resource]

The low survival rates of nuclear transfer fetuses and neonates in goats and cattle have been linked to placental abnormalities. A series of studies was designed to investigate the possibility of supplementing nuclear transfer embryos with electrofused embryos to generate placental tissue in goats and cattle. The initial study was designed to determine if the breeding season of goats could be extended with hCG treatment. Progesterone concentrations in treated does increased but pregnancy rates were unaffected. In the second study, goat embryos were electrofused and combined with nuclear transfer embryos at the 8-cell stage to produce the first offspring as a result of electrofused embryo complementation in goats. The remainder of the studies focused on electrofused embryos in cattle. The method of electrofusion was studied and it was determined that fusion efficiency and developmental rates after two fusogenic pulses were not different from fusion efficiency and developmental rates after a single pulse. The latter study also showed that the time of cleavage following in vitro fertilization affected the cleavage and blastocyst rates of embryos after electrofusion. In the next study, electrofused embryos were aggregated with nuclear transfer embryos at the 8-cell stage. Aggregate embryos developed to the blastocyst stage at the same rate as electrofused and nuclear transfer control embryos. The final study was a series of experiments conducted to characterize the nuclear status of electrofused embryos. In the first and second experiments of the series, embryos were stained following electrofusion and it was found that more embryos were tetraploid and fewer were binucleate when embryos were electrofused later after cleavage. The third and fourth experiments in this series examined the stage of the cell cycle prior to electrofusion. These experiments indicated that the embryos electrofused at 30 hours post-insemination were in the G2 phase of the cell cycle. It was concluded that the stage of the cell cycle would be an important factor in the production of tetraploid embryos via electrofusion and this should be the basis of future research in this area

Transversus abdominis is part of a global not local muscle synergy during arm movement

The trunk muscle transversus abdominis (TrA) is thought to be controlled independently of the global trunk muscles. Methodological issues in the 1990s research such as unilateral electromyography and a limited range of arm movements justify a re-examination of this theory. The hypothesis tested is that TrA bilateral co-contraction is a typical muscle synergy during arm movement. The activity of 6 pairs of trunk and lower limb muscles was recorded using bilateral electromyography during anticipatory postural adjustments (APAs) associated with the arm movements. The integrated APA electromyographical signals were analyzed for muscle synergy using Principle Component Analysis. TrA does not typically bilaterally co-contract during arm movements (1 out of 6 participants did). APA muscle activity of all muscles during asymmetrical arm movements typically reflected a direction specific diagonal pattern incorporating a twisting motion to transfer energy from the ground up. This finding is not consistent with the hypothesis that TrA plays a unique role providing bilateral, feedforward, multidirectional stiffening of the spine. This has significant implications to the theories underlying the role of TrA in back pain and in the training of isolated bilateral co-contraction of TrA in the prophylaxis of back pain

The Strong Symmetric Genus Spectrum of Abelian Groups

The strong symmetric genus of a group G is the minimum genus of any compact surface on which G acts faithfully while preserving orientation. We investigate the set of positive integers which occur as the strong symmetric genus of a finite abelian group. This is called the strong symmetric genus spectrum. We prove that there are an infinite number of gaps in the strong symmetric genus spectrum of finite abelian groups. We also determine an upper bound for the size of a finite abelian group that can act faithfully on a surface of a particular genus and then find the genus of abelian groups in particular families. These formulas produce a lower bound for the density of the strong symmetric genus spectrum

Polyphenolic Phenomena: Transgenic Analysis of Some of the Factors that Regulate the Cell-Specific Accumulation of Condensed Tannins (Proanthocyanidins) in Forage Crops

Condensed tannins biosynthesised within crops are a well-established mechanism for protecting plant protein in the rumen of grazing livestock. Protein protection mediated by these polymeric flavonoid molecules has been characterised in Lotus spp. and offers an interesting contrast to the polyphenol oxidase (PPO) system that confers protein protection in red clover

Plato on Well-Being

Plato's dialogues use several terms for the concept of well-being, which concept plays a central ethical role as the ultimate goal for action and a central political role as the proper aim for states. But the dialogues also reveal sharp debate about what human well-being is. I argue that they endorse a Socratic conception of well-being as virtuous activity, by considering and rejecting several alternatives, including an ordinary conception that lists a variety of goods, a Protagorean conception that identifies one's well-being with what appears one to be one's well-being, and hedonistic conceptions