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Search Results: 1 - 10 of 53250 matches for " David Hayward "
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The Construction and Realisation of Geographic Brand Rent in New Zealand Wine
David Hayward,Nicolas Lewis
Urbani Izziv , 2012,
Abstract: This paper examines the concept of geographic brand rent in production and marketing of New Zealand wine. It is argued that the region of origin for fine wine is not only a recognised feature of its value but that this may be conceived as a form of brand rent and furthermore that it is measurable. The analysis uses both cross-sectional and longitudinal approaches to consider grape and vineyard land prices, as well as interviews with industry informants to explore wine company strategies. Explicit use is made of the value-added chain in order to identify and situate the construction of rents and the positionality of industry actors in respect to these. The analysis highlights the quest to control different forms of brand rent that have led the restructuring of the wine industry. It also exposes countervailing pressures towards economic resilience and market vulnerability facing the fine wine industry.
Competing risk and heterogeneity of treatment effect in clinical trials
David M Kent, Alawi Alsheikh-Ali, Rodney A Hayward
Trials , 2008, DOI: 10.1186/1745-6215-9-30
Abstract: Recent commentaries have highlighted several fundamental limitations of clinical trials in providing an evidence-base for medical practice. It has been pointed out that many patients seen in routine clinical practice, particularly older and complex patients with multiple comorbid conditions, are excluded from clinical trials [1,2]. To address this, there has been a call for pragmatic comparative effectiveness trials with broader inclusion criteria, with the goal of enrolling a diverse patient population more representative of patients seen in routine clinical practice [3]. However, other commentaries have highlighted another limitation in clinical trials: substantial treatment-effect heterogeneity within trials often makes the overall summary result difficult to interpret and apply [4-7]. Enrolling a greater diversity of patients will increase this within trial heterogeneity. Thus, while some argue for broader inclusion criteria to make results more "generalizable", increasing patient heterogeneity yields overall results that are more likely to be uninformative or even misleading.While a consensus has yet to fully emerge on how best to deal with treatment-effect heterogeneity, the limitations of conventional subgroup analyses are well-appreciated. Since patients have multiple attributes that might affect the risks and benefits of an intervention – they are male or female, young or old, with or without diabetes, have a high or low blood pressure, blood count, cholesterol, urinary protein excretion, ejection fraction, etc. – it is statistically impractical to consider each potentially important attribute in a one at a time manner [6,7]. It has therefore been suggested that patient characteristic be combined by risk models that describe fundamental dimensions of risk likely to underpin treatment-effect heterogeneity [6,9-11].Prior work has demonstrated that variation in outcome-risk (i.e. a patient's baseline risk of having the outcome of interest) is a fundamental det
Room for improvement in diabetes care among First Nations in northern Quebec (Eeyou Istchee): reasonable management of glucose but poor management of complications
Mariam Naqshbandi Hayward,Elena Kuzmina,David Dannenbaum,Jill Torrie
International Journal of Circumpolar Health , 2012, DOI: 10.3402/ijch.v71i0.18418
Abstract: Objectives. To evaluate the clinical management of type 2 diabetes in the Eeyou Istchee communities of northern Quebec. Study design. Retrospective quality assurance audit. Methods. Patients with diabetes were identified using the Cree Diabetes Information System. Charts of eligible patients were audited for healthcare visits, glycemic control, blood pressure, lipid profile, pharmacological treatment and complications for the 2006 calendar year. Analyses were performed to assess the association of disease duration, age, target glycemic and blood pressure control with diabetes complications. Results. Half of the patients (49.7%) achieved target HbA1c, 53.6% had a blood pressure of ≤130/80 and 58.7% had an LDL of ≤2.5 mmol/L. The proportion of patients meeting all 3 targets was low at 17.1%. The mean number of diabetes-related clinic visits was high, with an average of 3.9 visits to a physician and an average of 8.7 visits to a registered nurse. Of patients with a documented diabetic complication, 39.4% of patients were not being managed with an ACE/ARB and 48.2% of patients were not prescribed a statin. Conclusions. These findings suggest a possible treatment gap for risk factors and complications management. To circumvent further increases in diabetes-related complications, emphasis should be placed on improved healthcare worker training, greater use of clinical management and patient education tools and improved communication during the diabetes-related clinical visits. Development of a culturally appropriate multidisciplinary approach towards improved understanding of diabetes and multifactorial risk management for diabetic patients is essential for the prevention of diabetic complications.
Longitudinal Relationships of Religion with Posttreatment Depression Severity in Older Psychiatric Patients: Evidence of Direct and Indirect Effects
R. David Hayward,Amy D. Owen,Harold G. Koenig,David C. Steffens,Martha E. Payne
Depression Research and Treatment , 2012, DOI: 10.1155/2012/745970
Abstract: Psychiatric patients (age 59+) were assessed before study treatment for major depressive disorder, and again after 3 months. Measures taken before study treatment included facets of religiousness (subjective religiosity, private prayer, worship attendance, and religious media use), social support, and perceived stress. Clinician-rated depression severity was assessed both before and after treatment using the Montgomery-?sberg Depression Rating Scale (MADRS). Structural equation modeling was used to test a path model of direct and indirect effects of religious factors via psychosocial pathways. Subjective religiousness was directly related to worse initial MADRS, but indirectly related to better posttreatment MADRS via the pathway of more private prayer. Worship attendance was directly related to better initial MADRS, and indirectly related to better post-treatment MADRS via pathways of lower stress, more social support, and more private prayer. Private prayer was directly related to better post-treatment MADRS. Religious media use was related to more private prayer, but had no direct relationship with MADRS. 1. Introduction A substantial body of research has linked religiousness with better mental health [1–3], particularly in older adulthood [4–6]. More intensely religious individuals have been found to be at lower risk for depression [7, 8] and, for those who do become depressed, to experience less severe symptoms [9–11] and faster remission [12, 13]. However, the nature of this relationship is complicated by a growing body of contrary findings that religion may be related to worse outcomes in some groups [8, 14], or that in some circumstances there may be a curvilinear relationship, with moderate levels of religiousness conferring the most benefits [9, 15]. Some of these discrepancies may be explained by the complexity of the construct of religion, which entails multiple aspects of belief and behavior such as participation in public worship services, engagement in private prayer, and perceiving order and meaning in one’s life. While these phenomena may be highly correlated, they may also have distinct and even contrasting psychological implications. For example, one recent study of lifetime risk of major depression found that while more frequent attendance at religious services appeared to be a protective factor, reporting a strong relationship with God was associated with more risk of depression [16]. Another study similarly found service attendance linked with lower risk of depression, but stronger self-rated religiousness associated with greater
Religious Factors and Hippocampal Atrophy in Late Life
Amy D. Owen,R. David Hayward,Harold G. Koenig,David C. Steffens,Martha E. Payne
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0017006
Abstract: Despite a growing interest in the ways spiritual beliefs and practices are reflected in brain activity, there have been relatively few studies using neuroimaging data to assess potential relationships between religious factors and structural neuroanatomy. This study examined prospective relationships between religious factors and hippocampal volume change using high-resolution MRI data of a sample of 268 older adults. Religious factors assessed included life-changing religious experiences, spiritual practices, and religious group membership. Hippocampal volumes were analyzed using the GRID program, which is based on a manual point-counting method and allows for semi-automated determination of region of interest volumes. Significantly greater hippocampal atrophy was observed for participants reporting a life-changing religious experience. Significantly greater hippocampal atrophy was also observed from baseline to final assessment among born-again Protestants, Catholics, and those with no religious affiliation, compared with Protestants not identifying as born-again. These associations were not explained by psychosocial or demographic factors, or baseline cerebral volume. Hippocampal volume has been linked to clinical outcomes, such as depression, dementia, and Alzheimer's Disease. The findings of this study indicate that hippocampal atrophy in late life may be uniquely influenced by certain types of religious factors.
Sox genes in the coral Acropora millepora: divergent expression patterns reflect differences in developmental mechanisms within the Anthozoa
Chuya Shinzato, Akira Iguchi, David C Hayward, Ulrich Technau, Eldon E Ball, David J Miller
BMC Evolutionary Biology , 2008, DOI: 10.1186/1471-2148-8-311
Abstract: Based on overall domain structures and HMG box sequences, the Acropora Sox genes considered here clearly fall into four of the five major Sox classes. AmSoxC is expressed in the ectoderm during development, in cells whose morphology is consistent with their assignment as sensory neurons. The expression pattern of the Nematostella ortholog of this gene is broadly similar to that of AmSoxC, but there are subtle differences – for example, expression begins significantly earlier in Acropora than in Nematostella. During gastrulation, AmSoxBb and AmSoxB1 transcripts are detected only in the presumptive ectoderm while AmSoxE1 transcription is restricted to the presumptive endoderm, suggesting that these Sox genes might play roles in germ layer specification. A third type B Sox gene, AmSoxBa, and a Sox F gene AmSoxF also have complex and specific expression patterns during early development. Each of these genes has a clear Nematostella ortholog, but in several cases the expression pattern observed in Acropora differs significantly from that reported in Nematostella.These differences in expression patterns between Acropora and Nematostella largely reflect fundamental differences in developmental processes, underscoring the diversity of mechanisms within the anthozoan Sub-Class Hexacorallia (Zoantharia).Sox genes encode a family of transcription factors that are defined by the presence of an HMG box resembling that of the human testis determinant, SRY. Sox transcription factors are restricted to the animal kingdom, but are highly diversified and widely distributed within it. Mouse and man have 20 Sox genes [1] whereas the model invertebrates Caenorhabditis and Drosophila have much less extensive Sox repertoires (5 and 8 genes respectively; [2-4]). Despite the diversity and heterogeneity of Sox genes, there are some cases of apparent orthology between Drosophila and mammals. For example, the similarity in HMG box sequences of group B1 Sox genes between Drosophila and vertebrat
Unexpected diversity of cnidarian integrins: expression during coral gastrulation
Brent A Knack, Akira Iguchi, Chuya Shinzato, David C Hayward, Eldon E Ball, David J Miller
BMC Evolutionary Biology , 2008, DOI: 10.1186/1471-2148-8-136
Abstract: Two novel integrins were identified in Acropora. AmItgα1 shows features characteristic of α integrins lacking an I-domain, but phylogenetic analysis gives no clear indication of its likely binding specificity. AmItgβ2 lacks consensus cysteine residues at positions 8 and 9, but is otherwise a typical β integrin. In situ hybridization revealed that AmItgα1, AmItgβ1, and AmItgβ2 are expressed in the presumptive endoderm during gastrulation. A second anthozoan, the sea anemone Nematostella vectensis, has at least four β integrins, two resembling AmItgβ1 and two like AmItgβ2, and at least three α integrins, based on its genomic sequence.In two respects, the cnidarian data do not fit expectations. First, the cnidarian integrin repertoire is more complex than predicted: at least two βs in Acropora, and at least three αs and four βs in Nematostella. Second, whereas the bilaterian αs resolve into well-supported groups corresponding to those specific for RGD-containing or laminin-type ligands, the known cnidarian αs are distinct from these. During early development in Acropora, the expression patterns of the three known integrins parallel those of amphibian and echinoderm integrins.Integrins are a large family of cell surface transmembrane receptors known only from metazoans, which function in intracellular signalling as well as cell-cell and cell-extracellular matrix (ECM) adhesion [1]. As the main mediators of cell-ECM interactions they are key players in early development [2] functioning in gastrulation by rapid modulation of their own adhesion between low and high affinity states and by modulating the activities of adhesion molecules (e.g. cadherins) in cell layers undergoing convergence and extension [3].Integrins function as αβ heterodimers with several subunits of each type being present in most animals. Analyses of the whole genome sequence of Caenorhabditis elegans [4,5] indicate that it has a single β subunit of the β1 type that is capable of associating with two α
Differential expression of three galaxin-related genes during settlement and metamorphosis in the scleractinian coral Acropora millepora
Alejandro Reyes-Bermudez, Zhiyi Lin, David C Hayward, David J Miller, Eldon E Ball
BMC Evolutionary Biology , 2009, DOI: 10.1186/1471-2148-9-178
Abstract: One of the Acropora genes (Amgalaxin) encodes a clear galaxin ortholog, while the others (Amgalaxin-like 1 and Amgalaxin-like 2) encode larger and more divergent proteins. All three proteins are predicted to be extracellular and share common structural features, most notably the presence of repetitive motifs containing dicysteine residues. In situ hybridization reveals distinct, but partially overlapping, spatial expression of the genes in patterns consistent with distinct roles in calcification. Both of the Amgalaxin-like genes are expressed exclusively in the early stages of calcification, while Amgalaxin continues to be expressed in the adult, consistent with the situation in the coral Galaxea.Comparisons with molluscs suggest functional convergence in the two groups; lustrin A/pearlin proteins may be the mollusc counterparts of galaxin, whereas the galaxin-like proteins combine characteristics of two distinct proteins involved in mollusc calcification. Database searches indicate that, although sequences with high similarity to the galaxins are restricted to the Scleractinia, more divergent members of this protein family are present in other cnidarians and some other metazoans. We suggest that ancestral galaxins may have been secondarily recruited to roles in calcification in the Triassic, when the Scleractinia first appeared. Understanding the evolution of the broader galaxin family will require wider sampling and expression analysis in a range of cnidarians and other animals.Although calcification – the deposition of calcium salts, usually to provide a form of skeletal support – is a widespread trait among animals, scleractinian corals are distinguished by the scale on which they carry out this process. In contrast to the internal skeletons of tetrapods and bony fish, which are based on calcium phosphate in the form of hydroxyapatite, many invertebrate skeletons are composed of CaCO3. This may take the form of either calcite or aragonite, which have distinct st
SiDCoN: A Tool to Aid Scoring of DNA Copy Number Changes in SNP Chip Data
Derek J. Nancarrow, Herlina Y. Handoko, Mitchell S. Stark, David C. Whiteman, Nicholas K. Hayward
PLOS ONE , 2007, DOI: 10.1371/journal.pone.0001093
Abstract: The recent application of genome-wide, single nucleotide polymorphism (SNP) microarrays to investigate DNA copy number aberrations in cancer has provided unparalleled sensitivity for identifying genomic changes. In some instances the complexity of these changes makes them difficult to interpret, particularly when tumour samples are contaminated with normal (stromal) tissue. Current automated scoring algorithms require considerable manual data checking and correction, especially when assessing uncultured tumour specimens. To address these limitations we have developed a visual tool to aid in the analysis of DNA copy number data. Simulated DNA Copy Number (SiDCoN) is a spreadsheet-based application designed to simulate the appearance of B-allele and logR plots for all known types of tumour DNA copy number changes, in the presence or absence of stromal contamination. The system allows the user to determine the level of stromal contamination, as well as specify up to 3 different DNA copy number aberrations for up to 5000 data points (representing individual SNPs). This allows users great flexibility to assess simple or complex DNA copy number combinations. We demonstrate how this utility can be used to estimate the level of stromal contamination within tumour samples and its application in deciphering the complex heterogeneous copy number changes we have observed in a series of tumours. We believe this tool will prove useful to others working in the area, both as a training tool, and to aid in the interpretation of complex copy number changes.
Multivariable risk prediction can greatly enhance the statistical power of clinical trial subgroup analysis
Rodney A Hayward, David M Kent, Sandeep Vijan, Timothy P Hofer
BMC Medical Research Methodology , 2006, DOI: 10.1186/1471-2288-6-18
Abstract: Using simulated clinical trials in which the probability of outcomes in individual patients was stochastically determined by the presence of risk factors and the effects of treatment, we examined the relative merits of a conventional vs. a "risk-stratified" subgroup analysis under a variety of circumstances in which there is a small amount of uniformly distributed treatment-related harm. The statistical power to detect treatment-effect heterogeneity was calculated for risk-stratified and conventional subgroup analysis while varying: 1) the number, prevalence and odds ratios of individual risk factors for risk in the absence of treatment, 2) the predictiveness of the multivariable risk model (including the accuracy of its weights), 3) the degree of treatment-related harm, and 5) the average untreated risk of the study population.Conventional subgroup analysis (in which single patient attributes are evaluated "one-at-a-time") had at best moderate statistical power (30% to 45%) to detect variation in a treatment's net relative risk reduction resulting from treatment-related harm, even under optimal circumstances (overall statistical power of the study was good and treatment-effect heterogeneity was evaluated across a major risk factor [OR = 3]). In some instances a multi-variable risk-stratified approach also had low to moderate statistical power (especially when the multivariable risk prediction tool had low discrimination). However, a multivariable risk-stratified approach can have excellent statistical power to detect heterogeneity in net treatment benefit under a wide variety of circumstances, instances under which conventional subgroup analysis has poor statistical power.These results suggest that under many likely scenarios, a multivariable risk-stratified approach will have substantially greater statistical power than conventional subgroup analysis for detecting heterogeneity in treatment benefits and safety related to previously unidentified treatment-related h
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