The design and performance of a real-time self excited vocoder

This paper is concerned with a generic class of predictive speech coders that includes the newly proposed Self Excited Vocoder (SEV) and the well known Code-Excited Linear Predictive Coder (CELPC). All members of this class form an excitation sequence for a linear predictive model filter using the same general model for the excitation signal. The general excitation model is based on a block coding technique where each sequence is drawn from an ensemble of sequences. This paper reports on two developments related to this general model. The first development is a new type of excitation ensemble that can in general be populated by many different types of sequences. The second development is a means of populating this new type of ensemble based on a vector quantizer design procedure using a new distortion measure

Studies of low oxidation state main group complexes: Their syntheses and reactivities

The work presented in this thesis describes the synthesis, structure and reactivities of a range of low oxidation state main group metal complexes. The work upon this subject is divided into six chapters. Chapter 1 provides a general introduction to the group 13 elements, low oxidation state group 13 chemistry and group 13 diyls. This chapter also describes the synthesis, theoretical treatments and reactivities of N-heterocyclic carbenes and their main group 13, 14 and 15 analogues, with a focus on the group 13 N-heterocyclic carbene analogues. Chapter 2 describes an investigation into the formation of transition metal complexes of an anionic gallium(I) N-heterocyclic carbene analogue, K(tmeda) Ga{ N(Ar)C(H) 2} , Ar = 2,6- diisopropylphenyl. These studies highlighted three different mechanistic pathways by which complexes could be isolated. Initially, substitution of a carbonyl ligand by the gallium carbene analogue in transition metal half sandwich carbonyl complexes was investigated. This yielded, for example, the first structurally authenticated Ga-V bond in K(tmeda) CpV(CO)3 Ga{ N(Ar)C(H) 2} , Cp = cyclopentadienyl. Secondly, the direct donation of the gallium carbene analogues lone pair of electrons towards a manganese dialkyl fragment gave the complex K(tmeda) Mn{CH(SiMe3)2}2 Ga{ N(Ar)C(H) 2} . Finally, the salt metathesis reactions of the gallium carbene analogue with a series of Lewis base stabilised transition metal di-halides were explored. Results include, a series of complexes taking the structural form M(tmeda) Ga{ N(Ar)C(H) 2} 2 , M = Mn, Fe, Co, Ni, Zn and the first structurally authenticated Ga-Cu bond in Cu(dppe) Ga{N(Ar)C(H)}2 , dppe = Bis(diphenylphosphino)ethane-P,P Chapter 3 details a study into the reactions of a gallium(III) heterocycle, l2Ga{ N(Ar)C(H) 2'} , by the group 2 metals calcium or magnesium. A series of gallium-group 2 metal bonded complexes have been isolated including, for example the first structurally authenticated group 13-group 2 bond in the complex Ca{Ga (N(Ar)C(H))2 }2(THF)4 . Furthermore, a subsequent investigation into the reactivity of an anionic gallium(I) N-heterocyclic carbene analogue, K(tmeda) Ga{ N(Ar)C(H) 2} , towards N-heterocyclic carbenes and imidazolium cations gave, in one case, the novel group 13 hydride complex HGa{ N(Ar)C(H) 2}(IMes) , IMes = l,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene. Chapter 4 describes the reactions of a paramagnetic gallium(II) dimeric complex, {(Bul- DAB )GaI}2 , with the alkali metal pnictides, ME(SiMe3)2 (M = Li or Na E = N, P or As). These reactions have led to a series of paramagnetic gallium(III)-pnictide complexes, (Bul- DAB)Ga{E(SiMe3)2}I (E = N, P, As) and (Bul-DAB)Ga{E(SiMe3)2}2 (E = P, As). The complex (Bul-DAB)Ga{As(SiMe3)2}I possesses the shortest Ga-As single bond yet recorded. Chapter 5 details an investigation into the reactivity of a amidinato germanium chloride complex, (Cl)Ge{N(Ar)C(But)N(Ar)} . This complex has been shown to participate in a range of different reactions. These are, salt metathesis giving, for example, the complex {(CO)2Fe(n5- Cp)}Ge{N(Ar)C(Bul)N(Ar)} and donation of a lone pair of electrons giving {(CO)5W}(Cl)Ge{N(Ar)C(But)N(Ar)} . Furthermore, an investigation into the synthesis of a range of amidinato bismuth complexes by salt metathesis is described. The first structurally characterised amidinato bismuth complexes, for example (u2-Br)Bi(Br) {(2,6- 'Pr2C6H3)N}2C(H) (THF) 2 , have been isolated and subsequent reductions have been attempted in some cases. Finally, chapter 6 describes some aspects of group 13 hydride chemistry and details the attempted syntheses of group 13 metal(II)-metal(II) bonded species. Complexes, for example QuinAl(H)2 tempo , Quin = l-azabicyclo 2.2.2 octane, tempo = 2,2,6,6-Tetramethyl-l- piperidinyloxy were isolated from reactions of a radical abstraction agent with Lewis base adducts of group 13 trihydrides

Microsatellites for the marsh fritillary butterfly: de novo transcriptome sequencing, and a comparison with amplified fragment length polymorphism (AFLP) markers.

Journal ArticleResearch Support, Non-U.S. Gov'tBACKGROUND: Until recently the isolation of microsatellite markers from Lepidoptera has proved troublesome, expensive and time-consuming. Following on from a previous study of Edith's checkerspot butterfly, Euphydryas editha, we developed novel microsatellite markers for the vulnerable marsh fritillary butterfly, E. aurinia. Our goal was to optimize the process in order to reduce both time and cost relative to prevailing techniques. This was accomplished by using a combination of previously developed techniques: in silico mining of a de novo assembled transcriptome sequence, and genotyping the microsatellites found there using an economic method of fluorescently labelling primers. PRINCIPAL FINDINGS: In total, we screened nine polymorphic microsatellite markers, two of which were previously published, and seven that were isolated de novo. These markers were able to amplify across geographically isolated populations throughout Continental Europe and the UK. Significant deviations from Hardy-Weinberg equilibrium were evident in some populations, most likely due to the presence of null alleles. However, we used an F(st) outlier approach to show that these markers are likely selectively neutral. Furthermore, using a set of 128 individuals from 11 populations, we demonstrate consistency in population differentiation estimates with previously developed amplified fragment length polymorphism (AFLP) markers (r = 0.68, p<0.001). SIGNIFICANCE: Rapid development of microsatellite markers for difficult taxa such as Lepidoptera, and concordant results with other putatively neutral molecular markers, demonstrate the potential of de novo transcriptional sequencing for future studies of population structure and gene flow that are desperately needed for declining species across fragmented landscapes.BBSRCOkinawa Institute for Science and Technology (OIST

Redshifts and Velocity Dispersions of Galaxy Clusters in the Horologium-Reticulum Supercluster

We present 118 new optical redshifts for galaxies in 12 clusters in the Horologium-Reticulum supercluster (HRS) of galaxies. For 76 galaxies, the data were obtained with the Dual Beam Spectrograph on the 2.3m telescope of the Australian National University at Siding Spring Observatory. After combining 42 previously unpublished redshifts with our new sample, we determine mean redshifts and velocity dispersions for 13 clusters, in which previous observational data were sparse. In six of the 13 clusters, the newly determined mean redshifts differ by more than 750 km/s from the published values. In the case of three clusters, A3047, A3109, and A3120, the redshift data indicate the presence of multiple components along the line of sight. The new cluster redshifts, when combined with other reliable mean redshifts for clusters in the HRS, are found to be distinctly bi-modal. Furthermore, the two redshift components are consistent with the bi-modal redshift distribution found for the inter-cluster galaxies in the HRS by Fleenor et al. (2005).Comment: 13 pages, 3 figures, Accepted to A

Thinking like a man? The cultures of science

Culture includes science and science includes culture, but conflicts between the two traditions persist, often seen as clashes between interpretation and knowledge. One way of highlighting this false polarity has been to explore the gendered symbolism of science. Feminism has contributed to science studies and the critical interrogation of knowledge, aware that practical knowledge and scientific understanding have never been synonymous. Persisting notions of an underlying unity to scientific endeavour have often impeded rather than fostered the useful application of knowledge. This has been particularly evident in the recent rise of molecular biology, with its delusory dream of the total conquest of disease. It is equally prominent in evolutionary psychology, with its renewed attempts to depict the fundamental basis of sex differences. Wars over science have continued to intensify over the last decade, even as our knowledge of the political, economic and ideological significance of science funding and research has become ever more apparent

Research priorities in land use and land-cover change for the Earth system and integrated assessment modelling

Copyright © 2010 Royal Meteorological Society and Crown Copyright.This special issue has highlighted recent and innovative methods and results that integrate observations and modelling analyses of regional to global aspect of biophysical and biogeochemical interactions of land-cover change with the climate system. Both the Earth System and the Integrated Assessment modeling communities recognize the importance of an accurate representation of land use and land-cover change to understand and quantify the interactions and feedbacks with the climate and socio-economic systems, respectively. To date, cooperation between these communities has been limited. Based on common interests, this work discusses research priorities in representing land use and land-cover change for improved collaboration across modelling, observing and measurement communities. Major research topics in land use and land-cover change are those that help us better understand (1) the interaction of land use and land cover with the climate system (e.g. carbon cycle feedbacks), (2) the provision of goods and ecosystem services by terrestrial (natural and anthropogenic) land-cover types (e.g. food production), (3) land use and management decisions and (4) opportunities and limitations for managing climate change (for both mitigation and adaptation strategies)

Investigation into the role of the germline epigenome in the transmission of glucocorticoid-programmed effects across generations.

BACKGROUND: Early life exposure to adverse environments affects cardiovascular and metabolic systems in the offspring. These programmed effects are transmissible to a second generation through both male and female lines, suggesting germline transmission. We have previously shown that prenatal overexposure to the synthetic glucocorticoid dexamethasone (Dex) in rats reduces birth weight in the first generation (F1), a phenotype which is transmitted to a second generation (F2), particularly through the male line. We hypothesize that Dex exposure affects developing germ cells, resulting in transmissible alterations in DNA methylation, histone marks and/or small RNA in the male germline. RESULTS: We profile epigenetic marks in sperm from F1 Sprague Dawley rats expressing a germ cell-specific GFP transgene following Dex or vehicle treatment of the mothers, using methylated DNA immunoprecipitation sequencing, small RNA sequencing and chromatin immunoprecipitation sequencing for H3K4me3, H3K4me1, H3K27me3 and H3K9me3. Although effects on birth weight are transmitted to the F2 generation through the male line, no differences in DNA methylation, histone modifications or small RNA were detected between germ cells and sperm from Dex-exposed animals and controls. CONCLUSIONS: Although the phenotype is transmitted to a second generation, we are unable to detect specific changes in DNA methylation, common histone modifications or small RNA profiles in sperm. Dex exposure is associated with more variable 5mC levels, particularly at non-promoter loci. Although this could be one mechanism contributing to the observed phenotype, other germline epigenetic modifications or non-epigenetic mechanisms may be responsible for the transmission of programmed effects across generations in this model

Natural Resistance-Associated Macrophage Protein Is a Cellular Receptor for Sindbis Virus in Both Insect and Mammalian Hosts

SummaryAlphaviruses, including several emerging human pathogens, are a large family of mosquito-borne viruses with Sindbis virus being a prototypical member of the genus. The host factor requirements and receptors for entry of this class of viruses remain obscure. Using a Drosophila system, we identified the divalent metal ion transporter natural resistance-associated macrophage protein (NRAMP) as a host cell surface molecule required for Sindbis virus binding and entry into Drosophila cells. Consequently, flies mutant for dNRAMP were protected from virus infection. NRAMP2, the ubiquitously expressed vertebrate homolog, mediated binding and infection of Sindbis virus into mammalian cells, and murine cells deficient for NRAMP2 were nonpermissive to infection. Alphavirus glycoprotein chimeras demonstrated that the requirement for NRAMP2 is at the level of Sindbis virus entry. Given the conserved structure of alphavirus glycoproteins, and the widespread use of transporters for viral entry, other alphaviruses may use conserved multipass membrane proteins for infection