Synthesis and characterisation of some novel low-coordinate phosphorus compounds containing bulky electron-withdrawing substituents

The synthesis of several new phosphorus derivatives including new monophosphanes of the type RPX(_2) (X = F, CI and H), containing either the Fluoromes [2,4,6-(CF(_3))(_3)C(_6)H(_2)] or Fluoroxyl [2,6-(CF(_3))(_2)C(_6)H(_3)] group has been carried out successfully. The synthesis of a number of Cis-Platin analogous has been facilitated by the reaction of these new monophosphanes with a platinum dimer [(PCl(_2)(Pet(_3))(_2)](_2). These compounds are of the type PtCl(_2)(Pet(_3))RPX(_2) (X = CI, H and F, R = 2,6- bis(trifluoromethyl)phenyl). These compounds have shown an interesting correlation between bond length and (^1)J(_p-pt) NMR coupling. Disubstituted phosphanes (RPX(_2), X = CI, H) have also been synthesised and subsequent reaction has facilitated the formation, characterisation and structure solution of a new phosphorus (I) species (RP(_2)(^(-)))(Ph(_3)PCH(_3))(^1) (R - Fluoromes).Attempts have been made to synthesise the first phosphaalkyne containing a bulky electron withdrawing ligand. This involved the reaction of RP=CCl(_2) (R = 2,6- bis(trifluoromethyl)phenyl) with a number of Pt(0) and Pd(0) species. (^31)P NMR studies have been used extensively throughout the project to help characterise and identify the products. The single crystal, solid state structures of many of the new species were elucidated by X-ray diffraction using a Siemens Smart CCD

Studies in Chiltern field systems

H.L.Gray, writing in 1915, stressed the fact that the Chiltern Hills lay in a transition area between Midland England, with its more regular open field arrangements, and the Southeast, with less regular systems. Basing his conclusions largely on sixteenth and early seventeenth century surveys, he showed that field systems within the Hills were different and distinctive from those on either side. The present study is the first comprehensive account of these distinctive systems. The medieval field arrangements of four parishes are examined in detail, and evidence for the whole region before 1850 is summarised. The most important features of the Chiltern field systems were: (1) the high proportion of enclosed arable land, particularly in the southwest; and (2) the existence of numerous, relatively small, common fields within the individual township. A three-course rotation had appeared as early as the twelfth century, and was later widely followed; but this does not imply the presence of a simple two- or three-field system. Farm holdings were concentrated in one part of a township, while the individual common arable holding was distributed irregularly between only a few of the many common fads. There was little meadow or grassland pasture, apart from that in parks, but woods and wastes were important elements, except in the northeast. The settlement pattern combined elements of both nucleation and dispersal. These features had appeared in the area by the mid-thirteenth century, when large-scale assarting was coming to an end. Their origins were, as Gray suggested, probably connected with the slow and piecemeal nature of colonisation in this hilly and heavily wooded region, and they survived largely unchanged until the mid-sixteenth century. After c.1550 the common field system began to disintegrate, with widespread piecemeal enclosure from the common arable, and almost all traces of the old arrangements bad disappeared by 1850

Estimates of cetacean abundance in the northern Gulf of Mexico from vessel surveys

The Southeast Fisheries Science Center (SEFSC) initiated annual, vessel-based visual sampling surveys of northern Gulf of Mexico marine mammals in 1990. The primary goal of these surveys was to meet Marine Mammal Protection Act requirements for estimating abundance and monitoring trends of marine mammal stocks in United States waters. The surveys were designed to collect: 1) marine mammal sighting data to estimate abundance and to determine distribution and diversity; and 2) environmental data to evaluate factors which may affect the distribution, abundance and diversity of marine mammals. The analyses for abundance estimation from the 1991-1994 surveys are presented in this report

MultiShape: A Spectral Element Method, with Applications to Dynamic Density Functional Theory and PDE-Constrained Optimization

A numerical framework is developed to solve various types of PDEs on complicated domains, including steady and time-dependent, non-linear and non-local PDEs, with different boundary conditions that can also include non-linear and non-local terms. This numerical framework, called MultiShape, is a class in Matlab, and the software is open source. We demonstrate that MultiShape is compatible with other numerical methods, such as differential--algebraic equation solvers and optimization algorithms. The numerical implementation is designed to be user-friendly, with most of the set-up and computations done automatically by MultiShape and with intuitive operator definition, notation, and user-interface. Validation tests are presented, before we introduce three examples motivated by applications in Dynamic Density Functional Theory and PDE-constrained optimization, illustrating the versatility of the method

Suppression of quantum oscillations and the dependence on site energies in electronic excitation transfer in the Fenna-Matthews-Olson trimer

Energy transfer in the photosynthetic complex of the Green Sulfur Bacteria known as the Fenna-Matthews-Olson (FMO) complex is studied theoretically taking all three subunits (monomers) of the FMO trimer and the recently found eighth bacteriochlorophyll (BChl) molecule into account. We find that in all considered cases there is very little transfer between the monomers. Since it is believed that the eighth BChl is located near the main light harvesting antenna we look at the differences in transfer between the situation when BChl 8 is initially excited and the usually considered case when BChl 1 or 6 is initially excited. We find strong differences in the transfer dynamics, both qualitatively and quantitatively. When the excited state dynamics is initialized at site eight of the FMO complex, we see a slow exponential-like decay of the excitation. This is in contrast to the oscillations and a relatively fast transfer that occurs when only seven sites or initialization at sites 1 and 6 is considered. Additionally we show that differences in the values of the electronic transition energies found in the literature lead to a large difference in the transfer dynamics

ELF5 isoform expression is tissue-specific and significantly altered in cancer.

BACKGROUND: E74-like factor 5 (ELF5) is an epithelial-specific member of the E26 transforming sequence (ETS) transcription factor family and a critical regulator of cell fate in the placenta, pulmonary bronchi, and milk-producing alveoli of the mammary gland. ELF5 also plays key roles in malignancy, particularly in basal-like and endocrine-resistant forms of breast cancer. Almost all genes undergo alternative transcription or splicing, which increases the diversity of protein structure and function. Although ELF5 has multiple isoforms, this has not been considered in previous studies of ELF5 function. METHODS: RNA-sequencing data for 6757 samples from The Cancer Genome Atlas were analyzed to characterize ELF5 isoform expression in multiple normal tissues and cancers. Extensive in vitro analysis of ELF5 isoforms, including a 116-gene quantitative polymerase chain reaction panel, was performed in breast cancer cell lines. RESULTS: ELF5 isoform expression was found to be tissue-specific due to alternative promoter use but altered in multiple cancer types. The normal breast expressed one main isoform, while in breast cancer there were subtype-specific alterations in expression. Expression of other ETS factors was also significantly altered in breast cancer, with the basal-like subtype demonstrating a distinct ETS expression profile. In vitro inducible expression of the full-length isoforms 1 and 2, as well as isoform 3 (lacking the Pointed domain) had similar phenotypic and transcriptional effects. CONCLUSIONS: Alternative promoter use, conferring differential regulatory responses, is the main mechanism governing ELF5 action rather than differential transcriptional activity of the isoforms. This understanding of expression and function at the isoform level is a vital first step in realizing the potential of transcription factors such as ELF5 as prognostic markers or therapeutic targets in cancer

Abundance of Bottlenose Dolphins, Tursiops truncatus, in the Coastal Gulf of Mexico

The abundance of bottlenose dolphins (Tursiops truncatus) for many coastal areas of the United States Gulf of Mexico is poorly known. During spring and fall 1987, we used aircraft and strip transects to estimate bottlenose dolphin abundance within 37 km of the U.S. Gulf shore. Greatest estimated dolphin densities were in the north-central Gulf (spring), northern Florida (fall) and Louisiana study areas (fall) (about 0.30 dolphins / km2). We estimated the coastal U.S. Gulf population of bottlenose dolphins to be 16,892 ± 3,628 (95% Cl) and 16,089 ± 3,338 in spring and fall, respectively. Bottlenose dolphins were found throughout the U.S. Gulf waters searched, but herds offshore of Texas were concentrated near passes and Louisiana herds were more common in and near eastern bays. Our estimates are one of the first assessments of the abundance and density of bottlenose dolphins throughout the coastal U.S. Gulf and may provide useful baseline estimates