An analysis of decoupling procedures in generating thermal Green's functions of O([lambda]â ´) by the Zubarev equation of motion method

The Zubarev equation of motion method has been applied to an anharmonic crystal of O( ,,4). All possible decoupling schemes have been interpreted in order to determine finite temperature expressions for the one phonon Green's function (and self energy) to 0()\4) for a crystal in which every atom is on a site of inversion symmetry. In order to provide a check of these results, the Helmholtz free energy expressions derived from the self energy expressions, have been shown to agree in the high temperature limit with the results obtained from the diagrammatic method. Expressions for the correlation functions that are related to the mean square displacement have been derived to 0(1\4) in the high temperature limit.

Assessment of chromatin activity in mouse and human tissues

Pancreatic deoxyribonuclease preferentially digests active genes during all phases of the cell cycle including mitosis. Recently, a DNAse I-directed in ~ nick translation technique has been used to demonstrate differences in the DNAse I sensitivity of euchromatic and heterochromatic regions of mitotic chromosomes. This ill ~ technique has been used in this study to ask whether facultative heterochromatin of the inactive X chromosome can be distinguished from the active X chromosome in mouse and human tissues. In addition to this, in ~ nick translation has been used to distinguish constitutive heterochromatin in mouse and human mitotic chromosomes. Based on relative levels of DNAse I sensitivity, the inactive X chromosome could not be distinguished from the active X chromosome in either mouse or human tissues but regions of constitutive heterochromatin could be distinguished by their relative DNAse I insensitivity. The use of !D situ nick translation was also applied to tissue sections of 7.5 day mouse embryos to ask whether differing levels of DNAse I sensitivity could be detected between different tissue types. Differences in DNAse I sensitivities were detected in three tissues examined; embryonic ectoderm, an embryo-derived tissue, and two extraembryonic tissues, extraembryonic ectoderm and ectoplacental cone. Embryonic ectoderm and extraembryonic ectoderm nuclei possessed comparable levels of DNAse I sensitivity while ectoplacental cone was significantly less DNAse I sensitive. This suggests that tissue-specific mechanisms such as chromatin structure may be involved in the regulation of gene activity in certain tissue types. This may also shed some light on possible tissue specific mechanisms regulating X chromosome activity in the developing mouse embryo.

Admiralty Commissioner's Orders, October 13, 1812.

Sir John Thomas Duckworth (1747-1817) served as Governor and Commander-in-Chief of Newfoundland when the United States declared war against Great Britain in 1812. He effectively prepared for the war by reviving and expanding the militia forces, establishing a signal station to warn of the approach of enemy ships, and strengthening the seaward forces. He resigned the post in December 1812 in order to take a parliamentary seat for New Romney, on the Kent coast. Sir William Domett (1752-1828) and Sir Joseph Sydney (1768-1831) were both naval officers and members of the Board of Admiralty when the United States declared war on Great Britain in 1812. Sir George Warrender, 4th Baronet (1782-1849), served as Lord of the Admiralty from 1812-1822, and as a Member of Parliament for various constituencies in Great Britain from 1807-1832. Sir John Barrow (1764-1848) was secretary of the Admiralty from 1804-1845, with the exception of the period from Feb. 1806-April 1807. He is best known for his support and encouragement of British exploration, especially in West Africa and the Arctic.