Showing papers by "University of Newcastle published in 2001"

A geochemical classification for granitic rocks

Abstract: This geochemical classification of granitic rocks is based upon three INTRODUCTION variables. These are FeO/(FeO + MgO) = Fe-number [or Although granitoids are the most abundant rock types FeO/(FeO + MgO) = Fe∗], the modified alkali–lime index in the continental crust, no single classification scheme (MALI) (Na2O + K2O – CaO) and the aluminum saturation has achieved widespread use. Part of the problem in index (ASI) [Al/(Ca – 1·67P + Na + K)]. The Fe-number granite classification is that the same mineral assemblage, (or Fe∗) distinguishes ferroan granitoids, which manifest strong iron quartz and feldspars with a variety of ferromagnesian enrichment, from magnesian granitoids, which do not. The ferroan minerals, can be achieved by a number of processes. and magnesian granitoids can further be classified into alkalic, Granitoids can form from differentiation of any hyalkali–calcic, calc-alkalic, and calcic on the basis of the MALI persthene-normative melt and from partial melting of and subdivided on the basis of the ASI into peraluminous, metamany rock types. Furthermore, granitic melts may be luminous or peralkaline. Because alkalic rocks are not likely to be derived solely from crustal components, may form from peraluminous and calcic and calc-alkalic rocks are not likely to be evolved mantle-derived melts, or may be a mixture peralkaline, this classification leads to 16 possible groups of granitic of crustal and mantle-derived melts. Because of this rocks. In this classification most Cordilleran granitoids are magnesian complexity, petrologists have relied upon geochemical and calc-alkalic or calcic; both metaluminous and peraluminous classifications to distinguish between various types of types are present. A-type granitoids are ferroan alkali–calcic, although granitoids. Approximately 20 different schemes have evolved over the past 30 years [see Barbarin (1990, 1999) some are ferroan alkalic. Most are metaluminous although some are for a summary thereof]. Most of these schemes are either peraluminous. Caledonian post-orogenic granites are predominantly genetic or tectonic in nature. This paper is an attempt magnesian alkali–calcic. Those with <70 wt % SiO2 are domto present a non-genetic, non-tectonic geochemical clasinantly metaluminous, whereas more silica-rich varieties are comsification scheme that incorporates the best qualities of monly peraluminous. Peraluminous leucogranites may be either the previous schemes, and to explain the petrologic magnesian or ferroan and have a MALI that ranges from calcic to processes that makes this scheme work. alkalic.

Design and use of questionnaires: a review of best practice applicable to surveys of health service staff and patients

Abstract: Questionnaires are often used to collect primaryquantitative data from patients and healthcareprofessionals. The aim is to gather valid, reliable,unbiased and discriminatory data from a represen-tative sample of respondents. However, theinformation yielded is subject to error and biasfrom a range of sources. Close attention to issuesof questionnaire design and survey administrationcan reduce these errors.

On the scattering problem for the camassa-Holm equation

Abstract: The Camassa–Holm equation has a number of constants of motion arising as eigenvalues of an associated spectral problem. We give a description of the spectral picture and discuss the scattering problem.

The inverse cascade and nonlinear alpha-effect in simulations of isotropic helical hydromagnetic turbulence

Abstract: A numerical model of isotropic homogeneous turbulence with helical forcing is investigated. The resulting flow, which is essentially the prototype of the α2 dynamo of mean field dynamo theory, produces strong dynamo action with an additional large-scale field on the scale of the box (at wavenumber k = 1; forcing is at k = 5). This large-scale field is nearly force free and exceeds the equipartition value. As the magnetic Reynolds number Rm increases, the saturation field strength and the growth rate of the dynamo increase. However, the time it takes to build up the large-scale field from equipartition to its final superequipartition value increases with magnetic Reynolds number. The large-scale field generation can be identified as being due to nonlocal interactions originating from the forcing scale, which is characteristic of the α-effect. Both α and turbulent magnetic diffusivity ηt are determined simultaneously using numerical experiments where the mean field is modified artificially. Both quantities are quenched in an Rm-dependent fashion. The evolution of the energy of the mean field matches that predicted by an α2 dynamo model with similar α and ηt quenchings. For this model an analytic solution is given that matches the results of the simulations. The simulations are numerically robust in that the shape of the spectrum at large scales is unchanged when changing the resolution from 303 to 1203 mesh points, or when increasing the magnetic Prandtl number (viscosity/magnetic diffusivity) from 1 to 100. Increasing the forcing wavenumber to 30 (i.e., increasing the scale separation) makes the inverse cascade effect more pronounced, although it remains otherwise qualitatively unchanged.

The Relationship among Dental Status, Nutrient Intake, and Nutritional Status in Older People:

Abstract: Dental health status may influence nutrition. The objective of this part of the National Diet and Nutrition Survey was to assess if there is a relationship between dental status in people 65 years and older and intake of certain nutrients and any link between dental status and blood-derived values of key nutrients. Random national samples of independently living subjects and those living in institutions had dental examinations, interviews, four-day food diaries, and blood and urine analyzed. In the sample living independently, intakes of most nutrients were lower in edentate than dentate subjects. Intake of non-starch polysaccharides, protein, calcium, non-heme iron, niacin, and vitamin C was significantly lower in edentate subjects. People with 21 or more teeth consumed more of most nutrients, particularly of non-starch polysaccharide. This relationship in intake was not apparent in the hematological analysis. Plasma ascorbate and plasma retinol were the only analytes significantly associated with dental status.

The intensification of rapid reactions in multiphase systems using slug flow in capillaries

Abstract: A multiphase microreactor based upon the use of slug flow through a narrow channel has been developed. The internal circulation, which is stimulated within the slugs by their passage along the channel, is responsible for a large enhancement in the interfacial mass transfer and the reaction rate. Mass transfer performance data has been obtained for a glass chip-based reactor in a 380 µm wide channel by monitoring the extraction of acetic acid from kerosene slugs as they moved along the reactor channel. Finally, the data was compared with that provided from other inter-phase contacting techniques.

Identification and isolation of human prostate epithelial stem cells based on α2β1-integrin expression

Abstract: A major impediment to our understanding of the biology of stem cells is the inability to distinguish them from their differentiating progeny. We made use of the known association of stem cells with basement membranes to isolate prostate epithelial stem cells. We show that, in vivo, putative stem cells express higher levels of the α2-integrin subunit than other cells within the basal layer. Approximately 1% of basal cells examined by confocal microscopy were integrin ‘bright’, and these cells can be selected directly from the tissue on the basis of rapid adhesion to type I collagen. This selected population has a basal phenotype, as determined by expression of CK5 and CK14 and lack of expression of the differentiation-specific markers prostate specific antigen (PSA) and prostatic acid phosphatase (PAP), and has a fourfold greater ability to form colonies in vitro than the total basal population. These putative stem cells are distinguished from other basal cells by their ability to generate prostate-like glands in vivo with morphologic and immuno-histochemical evidence of prostate-specific differentiation. These properties are consistent with a stem cell origin. Furthermore, the presence of surface integrins on prostate stem cells suggests that these cells share common pathways with stem cells in other tissues.

Refined explicit integration of elastoplastic models with automatic error control

Abstract: Effective explicit algorithms for integrating complex elastoplastic constitutive models, such as those belonging to the Cam clay family, are described. These automatically divide the applied strain increment into subincrements using an estimate of the local error and attempt to control the global integration error in the stresses. For a given scheme, the number of substeps used is a function of the error tolerance specified, the magnitude of the imposed strain increment, and the non‐linearity of the constitutive relations. The algorithms build on the work of Sloan in 1987 but include a number of important enhancements. The steps required to implement the integration schemes are described in detail and results are presented for a rigid footing resting on a layer of Tresca, Mohr‐Coulomb, modified Cam clay and generalised Cam clay soil. Explicit methods with automatic substepping and error control are shown to be reliable and efficient for these models. Moreover, for a given load path, they are able to control the global integration error in the stresses to lie near a specified tolerance. The methods described can be used for exceedingly complex constitutive laws, including those with a non‐linear elastic response inside the yield surface. This is because most of the code required to program them is independent of the precise form of the stress‐strain relations. In contrast, most of the implicit methods, such as the backward Euler return scheme, are difficult to implement for all but the simplest soil models.

Biodegradation of oil in uplifted basins prevented by deep-burial sterilization

Abstract: Biodegradation of crude oil by bacterial activity--which has occurred in the majority of the Earth's oil reserves--is known to reduce greatly the quality of petroleum in reservoirs. For economically successful prospecting for oil, it is therefore important to understand the processes and conditions in geological formations that lead to oil biodegradation. Although recent studies speculate that bacterial activity can potentially occur up to temperatures as high as 150 degrees C (refs 3, 4), it is generally accepted that effective petroleum biodegradation over geological timescales generally occurs in reservoirs with temperatures below 80 degrees C (ref. 2). This appears, however, to be at odds with the observation that non-degraded oils can still be found in reservoirs below this temperature. Here we compile data regarding the extent of oil biodegradation in several oil reservoirs, and find that the extensive occurrence of non-biodegraded oil in shallow, cool basins is restricted to those that have been uplifted from deeper, hotter regions of the Earth. We suggest that these petroleum reservoirs were sterilized by heating to a temperature around 80-90 degrees C during deep burial, inactivating hydrocarbon-degrading organisms that occur in the deep biosphere. Even when such reservoirs are subsequently uplifted to much cooler regions and filled with oil, degradation does not occur, implying that the sterilized sediments are not recolonized by hydrocarbon-degrading bacteria.

Scent-marking by male mammals: Cheat-proof signals to competitors and mates

Abstract: Summary Scent-marking is a ubiquitous form of olfactory signaling in male mammals and both territorial males in resource-defense mating systems and dominant males in dominance mating systems scent-mark. A large body of evidence suggests a link between scent-marking by male mammals and intrasexual competition. Resource holders appear to mark to help establish and maintain their status. They may do this because scent marks allow potential opponents to assess the status or RHP of the signaler. Nonresource holding competitors benefit because they can adjust the level of escalation in relation to potential costs and benefits and avoid risky contests. Resource holders benefit through reduced costs because many nonresource holders withdraw to avoid escalated contests. Three basic mechanisms allow receivers to make decisions after detecting scent marks. Receivers may (1) detect intrinsic properties of scent marks (e.g., concentrations of androgen-dependent volatiles), (2) remember past contests and the odor of each individual involved and associate these with the odor of scent marks, and (3) remember the smell of marks recently encountered and match this smell with potential opponents that they meet subsequently. It is now known that all of these mechanisms are used, sometimes within one species (e.g., mice) and we argue that the mechanisms are used conditionally, depending on information available and potential costs and benefits to receivers. Game theoretical analysis has recently shown how territorial intruders may switch from using intrinsic properties of marks to scent-matching when making decision about whether to remain in a territory. Scent-marking may be a uniquely cheat-proof signal of status because males must be able to defend their territory or dominance status over the time taken to mark it. A pattern of marks is thus a signal of status that has been tested in intrasexual competition. It also seems likely that marks are intrinsically costly both in energetic terms and by increasing predation risk. Mice can detect whether urine is from a parasitized or nonparasitized individual and these odors could potentially signal immunocompetence if mediated by variation at the MHC region of the genome. This remains to be tested. It is known that mice can detect relatedness via urine volatiles mediated by the MHC and it has been predicted that males should modify their competitive behavior in the light of this information. Again this remains to be tested. Information about disease status and genetic relatedness does not explain why males maintain patterns of scent marks. Most, perhaps all, territories are scent-marked. This may be because most intruders are of lower RHP than resource holders and these males should usually withdraw after assessing the resource holder by its scent marks. The costs of defending a territory may thus be substantially reduced. The obligate link between scent-marking and territoriality suggests that resource-defense polygyny in mammals may not be economically viable without this reduction in the costs of area defense. A little information is available to show that females use information from patterns of scent marks and a great deal of information shows that they use intrinsic information. It is not known whether males signal to females to enable mate choice or if females eavesdrop on signals sent between male competitors. Most known responses are to male urine by female rodents. For example, females show physiological (priming) responses to male odors (e.g., advancing and synchronizing estrus, inducing abortion). Other research has identified factors responsible for female mate preferences in choice tests. For example, the dominance status of the signaling male is a predictor of female interest and such studies have identified androgen-dependent volatiles responsible for the response. More recently, females have been shown to use odor mediated by the MHC locus to choose mates in relation to their genetic relatedness and to use odor to distinguish healthy and diseased mates. Most of these studies have been on mice and most use male urine, but the effect of patterns of urine scent marks has not been investigated. The only studies that explicitly use scent marks are those showing that females match the odor of potential mates with marks previously found in the environment to select mates. Future research should aim to clarify how information about the quality of potential mates is transmitted and how females trade-off such information against genetic relatedness.

Physiology and pathophysiology of poly(ADP-ribosyl)ation.

Abstract: One of the immediate eukaryotic cellular responses to DNA breakage is the covalent post-translational modification of nuclear proteins with poly(ADP-ribose) from NAD+ as precursor, mostly catalysed by poly(ADP-ribose) polymerase-1 (PARP-1). Recently several other polypeptides have been shown to catalyse poly(ADP-ribose) formation. Poly(ADP-ribosyl)ation is involved in a variety of physiological and pathophysiological phenomena. Physiological functions include its participation in DNA-base excision repair, DNA-damage signalling, regulation of genomic stability, and regulation of transcription and proteasomal function, supporting the previously observed correlation of cellular poly(ADP-ribosyl)ation capacity with mammalian life. The pathophysiology effects are mediated through PARP-1 overactivity, which can cause cell suicide by NAD+ depletion. It is apparent that the latter effect underlies the pathogenesis of a wide range of disease states including type-1 diabetes, ischaemic infarcts in various organs, and septic or haemorrhagic shock. Therefore pharmacological modulation of poly(ADP-ribosyl)ation may prove to be an exciting option for various highly prevalent, disabling and even lethal diseases.

A New Global Mode of Earth Deformation: Seasonal Cycle Detected

Abstract: We have detected a global mode of Earth deformation that is predicted by theory. Precise positioning of Global Positioning System sites distributed worldwide reveals that during February to March, the Northern Hemisphere compresses (and the Southern Hemisphere expands), such that sites near the North Pole move downward by 3.0 millimeters, and sites near the equator are pulled northward by 1.5 millimeters. The opposite pattern of deformation occurs during August to September. We identify this pattern as the degree-one spherical harmonic response of an elastic Earth to increased winter loading of soil moisture, snow cover, and atmosphere. Data inversion shows the load moment's trajectory as a great circle traversing the continents, peaking at 6.9 x 10(22) kilogram meters near the North Pole in winter, indicating interhemispheric mass exchange of 1.0 x 10(16) +/- 0.2 x 10(16) kilograms.

A Genomewide Scan for Loci Predisposing to Type 2 Diabetes in a U.K. Population (The Diabetes UK Warren 2 Repository): Analysis of 573 Pedigrees Provides Independent Replication of a Susceptibility Locus on Chromosome 1q

Abstract: Improved molecular understanding of the pathogenesis of type 2 diabetes is essential if current therapeutic and preventative options are to be extended. To identify diabetes-susceptibility genes, we have completed a primary (418-marker, 9-cM) autosomal-genome scan of 743 sib pairs (573 pedigrees) with type 2 diabetes who are from the Diabetes UK Warren 2 repository. Nonparametric linkage analysis of the entire data set identified seven regions showing evidence for linkage, with allele-sharing LOD scores ⩾1.18 ( P ≤.01). The strongest evidence was seen on chromosomes 8p21-22 (near D8S258 [LOD score 2.55]) and 10q23.3 (near D10S1765 [LOD score 1.99]), both coinciding with regions identified in previous scans in European subjects. This was also true of two lesser regions identified, on chromosomes 5q13 (D5S647 [LOD score 1.22] and 5q32 (D5S436 [LOD score 1.22]). Loci on 7p15.3 (LOD score 1.31) and 8q24.2 (LOD score 1.41) are novel. The final region showing evidence for linkage, on chromosome 1q24-25 (near D1S218 [LOD score 1.50]), colocalizes with evidence for linkage to diabetes found in Utah, French, and Pima families and in the GK rat. After dense-map genotyping (mean marker spacing 4.4 cM), evidence for linkage to this region increased to a LOD score of 1.98. Conditional analyses revealed nominally significant interactions between this locus and the regions on chromosomes 10q23.3 ( P =.01) and 5q32 ( P =.02). These data, derived from one of the largest genome scans undertaken in this condition, confirm that individual susceptibility-gene effects for type 2 diabetes are likely to be modest in size. Taken with genome scans in other populations, they provide both replication of previous evidence indicating the presence of a diabetes-susceptibility locus on chromosome 1q24-25 and support for the existence of additional loci on chromosomes 5, 8, and 10. These data should accelerate positional cloning efforts in these regions of interest.

A Changing Demographic Regime and Evolving Polycentric Urban Regions: Consequences for the Size, Composition and Distribution of City Populations

Abstract: The demographic regime in western Europe and many other countries of the developed world is now very different from that of 30-40 years ago and is continuing to evolve. At the same time, settlement systems have been altering significantly in spatial structure, notably in terms of the emergence of polycentric urban configurations. This paper examines the nature of these two sets of changes and searches for linkages between them. First, it outlines the main features of the changing demographic regime. Secondly, it attempts to identify what constitutes 'polycentric urban regions' as opposed to traditional monocentric structures. Thirdly, it assesses how recent demographic developments relate to traditional urban structures and discusses whether they are more conformable with polycentric urban forms.

Implementing product line variabilities

Abstract: Software product lines have numerous members. Thus, a product line infrastructure must cover various systems. This is the significant difference to usual software systems and the reason for additional requirements on the various assets present during software product line engineering. It is imperative that they support the description of the product line as a whole, as well as its instantiation for the derivation of individual products.Literature has already addressed how to create and instantiate generic product line assets, such as domain models and architectures to generate instance specific ones [1, 2, 3], yet little attention has been given on how to actually deal with this genericity at the code level.This paper addresses the issue of handling product line variability at the code level. To this end various implementation approaches are examined with respect to their use in a product line context.

Compartmentation of transport and transfer events in developing seeds

Abstract: Developing seeds are net importers of organic and inorganic nutrients. Nutrients enter seeds through the maternal vascular system at relatively high concentrations in the phloem. They exit importing sieve elements via interconnecting plasmodesmata and, during subsequent symplasmic passage, are sequestered into labile storage pools (vacuoles; starch). Transporters function to retrieve nutrients leaked to the seed apoplasm during symplasmic passage. Maternal cells responsible for nutrient release to the seed apoplasm are characteristically located at the maternal/filial interface. Their plasma membranes are enriched in transport proteins and, in some species, these cells are modified to a transfer cell morphology. Apoplasmic volumes of seeds are relatively small, but contain high concentrations of sugars, potassium and a range of amino acids. Sucrose and amino acids are taken up from the seed apoplasm by one to two cell layers of filial tissues that juxtapose the maternal tissues. The plasma membranes of the uptake cells are enriched in sucrose and amino acid/H(+) transporters which co-localize with H(+)-ATPASES: In some species, these cells are modified to a transfer cell morphology. High densities of plasmodesmata support symplasmic delivery of accumulated nutrients to underlying storage cells where polymer formation (starch, protein) takes place. Hexoses, resulting from sucrose hydrolysis and leakage to the seed apoplasm, are retrieved by hexose/H(+) symporters.

CNGA3 Mutations in Hereditary Cone Photoreceptor Disorders

Abstract: We recently showed that mutations in the CNGA3 gene encoding the α-subunit of the cone photoreceptor cGMP-gated channel cause autosomal recessive complete achromatopsia linked to chromosome 2q11. We now report the results of a first comprehensive screening for CNGA3 mutations in a cohort of 258 additional independent families with hereditary cone photoreceptor disorders. CNGA3 mutations were detected not only in patients with the complete form of achromatopsia but also in incomplete achromats with residual cone photoreceptor function and (rarely) in patients with evidence for severe progressive cone dystrophy. In total, mutations were identified in 53 independent families comprising 38 new CNGA3 mutations, in addition to the 8 mutations reported elsewhere. Apparently, both mutant alleles were identified in 47 families, including 16 families with presumed homozygous mutations and 31 families with two heterozygous mutations. Single heterozygous mutations were identified in six additional families. The majority of all known CNGA3 mutations (39/46) are amino acid substitutions compared with only four stop-codon mutations, two 1-bp insertions and one 3-bp in-frame deletion. The missense mutations mostly affect amino acids conserved among the members of the cyclic nucleotide gated (CNG) channel family and cluster at the cytoplasmic face of transmembrane domains (TM) S1 and S2, in TM S4, and in the cGMP-binding domain. Several mutations were identified recurrently (e.g., R277C, R283W, R436W, and F547L). These four mutations account for 41.8% of all detected mutant CNGA3 alleles. Haplotype analysis suggests that the R436W and F547L mutant alleles have multiple origins, whereas we found evidence that the R283W alleles, which are particularly frequent among patients from Scandinavia and northern Italy, have a common origin.

Mapping the biomass of Bornean tropical rain forest from remotely sensed data

Abstract: The biomass and biomass dynamics of forests are major uncertainties in our understanding of tropical environments. Remote sensing is often the only practical means of acquiring information on forest biomass but has not always been used successfully. Here the conventional approaches to the estimation of forest biomass from remotely sensed data were evaluated relative to techniques based on the application of artificial neural networks. Together these approaches were used to estimate and map the biomass of tropical forests in north-eastern Borneo from Landsat TM data. The neural networks were found to be particularly suited to the application. A basic multi-layer perceptron network, for example, provided estimates of biomass that were strongly correlated with those measured in the field (r = 0.80). Moreover, these estimates were more strongly correlated with biomass than those derived from 230 conventional vegetation indices, including the widely used normalized difference vegetation index (NDVI).

Prevalence of impacts of dental and oral disorders and their effects on eating among older people; a national survey in Great Britain

Abstract: –Objective: The objective was to assess the prevalence, in a British population aged 65 years and older, of oral health related impacts and the effects they had on the quality of daily life and in particular on eating. Methods: 753 free living and 202 institutionalised subjects aged 65 years and over, participating in the oral health survey of the British National Diet and Nutrition Survey (NDNS), had a dental examination and interview. Data on the impact of dental and oral disorders on the activities of daily living based upon the modified Oral Impacts on Daily Performance (OIDP) indicator were collected. Results: 17% of the free living edentate participants reported that their mouth affected their pattern of daily living on a regular basis. Oral impacts levels were lowest in dentate subjects with the greatest number of teeth. For the dentate, the most common oral impacts were on eating and speaking. Impacts relating to emotional stability, sleeping, relaxing, carrying out physical activity and social contact were very infrequent, but were severe when they did occur. Among those with an impact on eating, 25% said it was severe and 42% had the impact nearly every day or in a spell of 3 or more months. Oral impacts were more prevalent among the institution sample, particularly the dentate. The impacts were associated with the inability or difficulty to eat a range of 16 common foods. Conclusion: This survey has shown that the oral status of older people fairly frequently affects the quality of life of older people, and in particular, the ability to eat several common types of foods.

Rivastigmine in the treatment of parkinsonian psychosis and cognitive impairment: preliminary findings from an open trial.

Abstract: This open study assessed the ability of rivastigmine to treat the neuropsychiatric complications of advanced Parkinson's disease. In a group of 12 patients, hallucinations, sleep disturbance, and carer distress were all improved and cognitive performance significantly enhanced by the drug.

Linking sponsorship and cause related marketing

Abstract: Sponsorship activities have become a mainstream component of the marketing mix. As such, there are attempts to make these activities more effective by leveraging them using advertising, sales promotions, or in an increasing number of cases, through cause related marketing (CRM). This paper explores the relationship between sponsorship and CRM and identifies the potential opportunities that arise from leveraging sponsorships using CRM. The paper also examines the limitations of CRM as a leveraging strategy, puts forward a typology for categorising CRM and identifies some future research issues related to CRM‐leveraging of sponsorship.