Tear film surface quality with soft contact lenses using dynamic-area high-speed videokeratoscopy

Objectives. To evaluate the performance of the dynamic-area high-speed videokeratoscopy technique in the assessment of tear film surface quality with and without the presence of soft contact lenses on eye. Methods. Retrospective data from a tear film study using basic high-speed videokeratoscopy, captured at 25 frames per second, (Kopf et al., 2008, J Optom) were used. Eleven subjects had tear film analysis conducted in the morning, midday and evening on the first and seventh day of one week of no lens wear. Five of the eleven subjects then completed an extra week of hydrogel lens wear followed by a week of silicone hydrogel lens wear. Analysis was performed on a 6 second period of the inter-blink recording. The dynamic-area high-speed videokeratoscopy technique uses the maximum available area of Placido ring pattern reflected from the tear interface and eliminates regions of disturbance due to shadows from the eyelashes. A value of tear film surface quality was derived using image rocessing techniques, based on the quality of the reflected ring pattern orientation. Results. The group mean tear film surface quality and the standard deviations for each of the conditions (bare eye, hydrogel lens, and silicone hydrogel lens) showed a much lower coefficient of variation than previous methods (average reduction of about 92%). Bare eye measurements from the right and left eyes of eleven individuals showed high correlation values (Pearson’s correlation r = 0.73, p < 0.05). Repeated measures ANOVA across the 6 second period of measurement in the normal inter-blink period for the bare eye condition showed no statistically significant changes. However, across the 6 second inter-blink period with both contact lenses, statistically significant changes were observed (p < 0.001) for both types of contact lens material. Overall, wearing hydrogel and silicone hydrogel lenses caused the tear film surface quality to worsen compared with the bare eye condition (repeated measures ANOVA, p < 0.0001 for both hydrogel and silicone hydrogel). Conclusions. The results suggest that the dynamic-area method of high-speed videokeratoscopy was able to distinguish and quantify the subtle, but systematic worsening of tear film surface quality in the inter-blink interval in contact lens wear. It was also able to clearly show a difference between bare eye and contact lens wearing conditions.

The relationship between organizational and professional commitment in the case of project workers : implications for project management

The purpose of this article is to investigate the relationship between organizational and professional commitment of project workers. We first present (1) role-conflict theory and exchange theory to establish the multiple dimensions of commitment (affective, continuance, and normative) and (2) social identity theory to support our argument for different foci of commitment—organization and profession. Building on these theoretical lenses, we present the literature review that compares organizational and professional commitment of project workers with respect to the three dimensions of commitment. Adopting a positivist approach and a sample of 141 project workers, we use Pearson’s correlation to identify the relationship between affective organizational and affective professional, continuance organizational and continuance professional, and normative organizational and normative professional commitment. We report significant correlation between affective organizational commitment and affective professional commitment of project workers. The correlations between continuance organizational commitment and continuance professional commitment and normative organizational commitment and normative professional commitment are moderate. We then discuss the implications of these findings for the project management profession.

The relation between work motivation and project management success : an empirical investigation

The content and context of work significantly influences an employees’ satisfaction. While managers see work motivation as a tool to engage the employees so that they perform better, academicians value work motivation for its contribution to human behaviour. Though the relationship between employee motivation and project success has been extensively covered in the literature, more research focusing on the nature of job design on project success may have been wanting. We address this gap through this study. The present study contributes to the extant literature by suggesting an operational framework of work motivation for project—based organizations. We are also advancing the conceptual understanding of this variable by understanding how the different facets of work motivation have a differing impact of the various parameters of project performance. A survey instrument using standardized scales of work motivation and project success was used. 199 project workers from various industries completed the survey. We first ‘operationalized’ the definition of work motivation for the purpose of our study through a principal component analysis of work motivation items. We obtained a five factor structure that had items pertaining to employee development, work climate, goal clarity, and job security. We then performed a Pearson’s correlation analysis which revealed moderate to significant relationship between project outcomes ad work climate; project outcomes & employee development. In order to establish a causality between work motivation and project management success, we employed linear regression analysis. The results show that work climate is a significant predictor of client satisfaction, while it moderately influences the project quality. Further, bringing in objectivity to project work is important for a successful implementation.

The relation between organizational and professional commitment in case of project workers : implications for the project management

The purpose of this paper is to investigate the relationship between organizational and professional commitment of project workers. We first present (i) role–conflict theory, and exchange theory to establish the multiple dimensions of commitment—affective, continuance, and normative; and (ii). social–identity theory to support our argument for different foci of commitment—organization and profession. Building on these theoretical lenses, we present the literature review that compares organizational and professional commitment of project workers with respect to the 3 dimensions of commitment. Adopting a positivist approach and a sample of 141 project workers, we use Pearson’s correlation to identify the relationship between affective organizational and affective professional, continuance organizational and continuance professional, and normative organizational and normative professional commitment. We report significant correlation between affective organizational commitment and affective professional commitment of project workers. The correlations between continuance organizational commitment, and continuance professional commitment; and normative organizational commitment, and normative professional commitment are moderate. We then discuss the implications of these findings for the project management profession.

Translation and psychometric properties of the Chinese version of the Leeds Attitudes to Concordance II scale

Background Concordance is characterised as a negotiation-like health communication approach based on an equal and collaborative partnership between patients and health professionals. The Leeds Attitudes to Concordance II (LATCon II) scale was developed to measure the attitudes towards concordance. The purpose of this study was to translate the LATCon II into Chinese and psychometrically test the Chinese version of LATCon II (C-LATCon II). Methods The study involved three phases: i) translation and cross-cultural adaptation; ii) pilot study, and; iii) a cross-sectional survey (n = 366). Systematic random sampling was used to recruit hypertensive patients from nine communities covering around 78,000 residents in China. Tests of psychometric properties included content validity, construct validity, criteria-related validity (correlation between the C-LATCon II and the Therapeutic Adherence Scale for Hypertensive Patients (TASHP)), internal reliability, and test-retest reliability (n = 30). Results The study found that the C-LATCon II had a satisfactory content validity (item-level Content Validity Index (CVI) = 0.83-1, scale-level CVI/universal agreement = 0.89, and scale-level CVI/averaging calculation = 0.98), construct validity (four components extracted explained 56.66% of the total variance), internal reliability (Cronbach’s alpha of overall scale and four components was 0.78 and 0.66-0.84, respectively), and test-retest reliability (Pearson’s correlation coefficient = 0.82, p < 0.001; interclass correlation coefficient = 0.82, p < 0.001; linear weighted kappa3 statistic for each item = 0.40-0.65, p < 0.05). Criteria-related validity showed a weak association (Pearson’s correlation coefficient = 0.11, p < 0.05) between patients’ attitudes towards concordance during health communication and their health behaviours for hypertension management. Conclusions The C-LATCon II is a validated and reliable instrument which can be used to evaluate the attitudes to concordance in Chinese populations. Four components (health professionals’ attitudes, partnership between two parties, therapeutic decision making, and patients’ involvement) describe the attitudes towards concordance during health communication.

Influence of land use changes in river basins on diversity and distribution of amphibians

Land-use changes influence local biodiversity directly, and also cumulatively, contribute to regional and global changes in natural systems and quality of life. Consequent to these, direct impacts on the natural resources that support the health and integrity of living beings are evident in recent times. The Western Ghats being one of the global biodiversity hotspots, is reeling under a tremendous pressure from human induced changes in terms of developmental projects like hydel or thermal power plants, big dams, mining activities, unplanned agricultural practices,monoculture plantations, illegal timber logging, etc. This has led to the once contiguous forest habitats to be fragmented in patches, which in turn has led to the shrinkage of original habitat for the wildlife, change in the hydrological regime of the catchment, decreased inflow in streams,human-animal conflicts, etc. Under such circumstances, a proper management practice is called for requiring suitable biological indicators to show the impact of these changes, set priority regions and in developing models for conservation planning. Amphibians are regarded as one of the best biological indicators due to their sensitivity to even the slightest changes in the environment and hence they could be used as surrogates in conservation and management practices. They are the predominating vertebrates with a high degree of endemism (78%) in Western Ghats. The present study is an attempt to bring in the impacts of various land-uses on anuran distribution in three river basins. Sampling was carried out for amphibians during all seasons of 2003-2006 in basins of Sharavathi, Aghanashini and Bedthi. There are as many as 46 species in the region, one of which is new to science and nearly 59% of them are endemic to the Western Ghats. They belong to nine families, Dicroglossidae being represented by 14 species,followed by Rhacophoridae (9 species) and Ranidae (5 species). Species richness is high in Sharavathi river basin, with 36 species, followed by Bedthi 33 and Aghanashini 27. The impact of land-use changes, was investigated in the upper catchment of Sharavathi river basin. Species diversity indices, relative abundance values, percentage endemics gave clear indication of differences in each sub-catchment. Karl Pearson’s correlation coefficient (r) was calculated between species richness, endemics, environmental descriptors, land-use classes and fragmentation metrics. Principal component analysis was performed to depict the influence of these variables. Results show that sub-catchments with lesser percentage of forest, low canopy cover, higher amount of agricultural area, low rainfall have low species richness, less endemic species and abundant non-endemic species, whereas endemism, species richness and abundance of endemic species are more in the sub-catchments with high tree density, endemic trees, canopy cover, rainfall and lower amount of agriculture fields. This analysis aided in prioritising regions in the Sharavathi river basin for further conservation measures.

Spatial and seasonal relationships between Pacific harbor seals (Phoca vitulina richardii) and their prey, at multiple scales

Knowing where pinnipeds forage is vital to managing and protecting their populations, and for assessing potential interactions with fisheries. We assessed the spatial relationship between the seasonal distribution of Pacific harbor seals (Phoca vitulina richardii) outfitted with satellite transmitters and the seasonal distributions of potential harbor seal prey species in San Francisco Bay, California. Pearson’s correlation coefficients were calculated between the number of harbor seal locations in an area of the San Francisco Bay and the abundance of specific prey species in the same area. The influence of scale on the analyses was assessed by varying the scale of analysis from 1 to 10 km. There was consistency in the prey species targeted by harbor seals year-round, although there were seasonal differences between the most important prey species. The highest correlations between harbor seals and their prey were found for seasonally abundant benthic species, located within about 10 km of the primary haul-out site. Probable foraging habitat for harbor seals was identified, based on areas with high abundances of prey species that were strongly correlated with harbor seal distribution. With comparable local data inputs, this approach has potential application to pinniped management in other areas, and to decisions about the location of marine reserves designed to protect these species.

同源四倍体水稻雌配子体发育特性及变异胚囊研究

通过秋水仙素诱导获得同源四倍体水稻10个株系，包括6个恢复系、3个保持系和1个不育系，这些株系具有加倍的染色体组。田间观察表明10个株系具有特殊的农艺性状：茎杆变粗壮、植株颜色加深、叶片变厚、叶宽适度增加、分蘖数减少、有效分蘖的比率下降等。根尖有丝分裂鉴定表明，同源四倍体水稻10个株系具有正常的有丝分裂，观察细胞的染色体数目皆为2n=48。花粉母细胞减数分裂鉴定表明10个株系具有比较理想的减数分裂行为，后期I染色体滞后、末期I微核生成和末期II异常小孢子比率较低，能较好的完成减数分裂过程，其中后期I染色体滞后比率约为10%-20%，末期I微核生成比率约为1%-6%，末期II异常小孢子比率约为1%-8%。这提示，染色体联合和分离不规则导致三价体、单价体 和落后染色体等产生，并进一步导致在后期和末期不均横分离产生异常小孢子，这可能是同源四倍体株系结实率不高的原因之一。 同源四倍体水稻正常胚囊为蓼型，变异胚囊具有多种类型，其比率显著高于二倍体对照，变化范围为39.62%－69.85%。按变异胚囊的结构特点和形成方式，分为四种类型：退化型，结构变异型，无融合生殖型和反足细胞增殖型。退化型胚囊的平均比率为29.17%，包括小胚囊（15.04%）和完全退化胚囊（14.13%），前者仍有较小胚囊腔而后者胚囊腔缺失。结构变异胚囊包括结构缺失、结构重复和位置异常，反映了蓼型胚囊八核七细胞结构的变异，其在各株系的平均比率为18.96%。无融合生殖胚囊发生比率极低，平均比率为1.77%，类型包括反足胚和卵细胞胚。反足细胞增殖胚囊是反足细胞团频繁增殖形成，伴随上述三种变异发生使异常胚囊的多样性进一步增加，其在各株系的平均比率为10.62%。相关分析表明，同源四倍体水稻结实可能主要来自三部分：正常胚囊、正常型小胚囊和反足细胞增殖型胚囊。这三种胚囊具有相对完整的蓼型结构，可能具有较好的育性，其对结实率的贡献程度估计值分别为72.44%、15.12%、12.44%。此外，完全退化型胚囊和位置异常型胚囊对结实率分别表现出显著（-0.66）和极显著（-0.92）的负相关，这表明二者可能是结实性的抑制因素。 Ten autotetraploid strains, which include six restoring lines, three maintaining lines and a sterile line, are derived from artificial induction by colchicine treatments. Variations of agronomical traits are observed which include large organs, sturdy plants, long panicle length and deep leaf color and so on. It has been confirmed that autotetraploid strains exhibit normal chromosome behaviors in mitosis and the chromosome numbers are all 48. Moreover, abnormal chromosome behaviors are investigated in meiosis including univalent, trivalent, quatrivalent, chromosome lagging and microkernel and so on. It evaluates that the percentage of chromosome lagging in anaphase I is about 10%-20%, the percentage of microkernel in telophase I is about 1%-6% and the percentage of abnormal microspore in telophase II is about 1%-8%. In all, abnormal behaviors of chromosomes could induce univalent, trivalent and et al. and subsequently induce infertile microspore. That may be one of the causes of low seed sets in autotetraploid strains. Embryo sacs of autotetraploid strains are formed according to the Polygonum type. However, these strains exhibit variations of abnormal embryo sacs at high frequencies (39.62% - 69.85%). The variations are frequently involved in the spikelets of the main panicles and the first tillers, leading to obvious decreases of the percentages of normal embryo sacs among the strains. Four types of abnormal embryo sacs are classified basing on their different structures and origins: degenerated embryo sac (DES), structure variation (SV), apomixis (Apo) and antipodal cell proliferation (ACP). Embryo sacs of DES (29.17%) exhibit small embryo sacs (15.04%) or no embryo sac (14.13%), the former showing embryo sacs with decreased size and the latter showing no sac. Embryo sacs of AS (18.96%) include three subtypes: structure deletion, structure duplication and location variation, which suggests abnormalities of the eight nuclei, seven celled pattern of the Polygonum type. Embryo sacs of Apo (only 1.77%) include two origins of apomictic embryos: antipodal embryo and egg embryo. Embryo sacs of ACP are observed frequently (10.62%) in autotetraploid strains which subsequently increase the variations of abnormal embryo sacs. It evaluates by the Pearson’s correlation analysis that seed set is probably contributed by three origins of embryo sacs: normal embryo sacs, small embryo sacs (normal pattern) and embryo sacs of ACP. These three origins exhibit comparatively good structure of the Polygonum type and could account for seed set at a percentage of 72.44%, 15.12%, 12.44%, respectively. Moreover, the subtype of no embryo sac (NES) negatively related to seed set at the P>0.01 level (-0.92) and the subtype of location variation (LV) negatively related to seed set at the P>0.05 level (-0.66). Which suggest the two subtypes may have strong stress on seed set.

PET-CT as a predictor of outcome in resectable colorectal liver metastases

Introduction
PET-computed tomography (PET-CT) is a useful staging imaging modality in colorectal liver metastases (CRLM). This study aimed to determine whether PET-CT parameters, standardized uptake value (SUV) and reconstructed tumour volume (RTV), are predictors of prognosis and survival.

Methods
A study of all resectable CRLM patients in the regional HPB unit from 2007–2009 was performed. Preoperative PET-CT scans were retrospectively reviewed; SUV, diameter and RTV for each lesion was recorded. Correlation analysis was performed with other pathological and biochemical parameters, by Pearson’s correlation analysis. Survival analysis was performed using Cox regression hazard model. A P value of less than 0.05 was considered statistically significant.

Results
A total of 79 patients were included. SUV moderately correlated with tumour diameter, both PET-CT (r=0.4927; P<0.0001) and histology (r=0.4513; P=0.0003); RTV (r=0.4489; P<0.001), preoperative carcinoembryonic antigen (CEA) (r=0.4977; P=0.0001), and postoperative CEA (r=0.3727; P=0.004). Multivariate analysis found that an independent predictor of SUVmax was preoperative CEA (P=0.03). RTV strongly correlated with preoperative CEA (r=0.9389; P<0.0001). SUV and RTV had a negative effect on survival.

Conclusion
PET-CT, in the setting of CRLM, may have a prognostic role in assessing survival. Although no definite conclusions can be drawn regarding the prognostic role of SUV and RTV, it acts to reinforce the need for further prospective studies to validate these findings.

O grau de investimento definido por um indicador económico e financeiro

No contexto econômico competitivo e globalizado no qual as corporações estão inseridas, emerge a necessidade de evolução constante para acompanhar as mudanças que o ambiente lhes impõe, visando a sustentabilidade e a perpetuidade. A evolução econômica e financeira das corporações pode promover o desenvolvimento de uma nação, mesmo que o aumento da concorrência no mercado obrigue-as a investirem em novas relações com o seu universo, buscando melhorar os seus níveis de desempenho mensurados por meio de novos instrumentos economicos e financeiros. Desta forma, o grau de investimento corporativo passa a ser relevante, pois pode gerar confiança em novos investimentos, sendo visto como sinônimo de economia forte. No concernente ao objetivo, esta tese teve como escopo o desenvolvimento de um indicador econômico e financeiro visando balizar o grau de credibilidade rating que as corporações apresentam em sua estrutura corporativa, por meio de um conjunto de índices econômicos e financeiros ligados à liquidez, à lucratividade, ao endividamento e à rentabilidade, provindos das demonstrações econômicas e financeiras das corporações estudadas. Este estudo caracteriza-se no contexto da tipologia aplicada, de objetivo descritivo com delineamento bibliográfico, na amplitude da problemática, caracteriza-se como quantitativo, compreendendo a população de 70 corporações brasileiras reconhecidas pelas certificadoras internacionais, Standard & Poor's, Moody's e Fitch Ratings, as quais detinham o grau de investimento corporativo no ano de 2008. Quanto aos métodos e procedimentos estatísticos, primeiramente utilizou-se a análise descritiva com vistas ao resumo dos dados, posteriormente foi feita a análise de correlação por meio do Coeficiente de Correlação Linear de Pearson, aplicando-se em seguida a análise de regressão. Em seguida para a confecção do modelo utilizou-se a análise fatorial e para testificar sua confiabilidade o Alfa de Cronbach, utilizou-se também a análise discriminante, para classificação dos quartis. As conclusões do estudo baseiamse nos resultados apresentados pela evolução do tratamento estatístico, que inicialmente apresentam uma correlação predominantemente fraca, no entanto isto não invalida a correlação de Pearson, pois todos os coeficientes apresentaram uma significância de (p<0,05). Na aplicação da análise de regressão, todos os modelos apresentaram resultados satisfatórios sendo perceptível a existência de uma forte correlação. A confiabilidade do modelo de grau de investimento corporativo provindo da análise fatorial foi testificada pelo coeficiente do Alpha de Cronbach, que apresentou valor de 0,768, o que indica consistência interna satisfatória ao estudo. O grau de investimento na base longitudinal de 2008 a 2010 apresenta variabilidade de 95,72% a 98,33% de acertividade. Portanto, conclui-se que o indicador criado por este estudo, possui condições de ser utilizado como base de definição do grau de investimento de corporações empresariais.

Dynamic analysis of earthquake phenomena by means of pseudo phase plane

This paper analyses earthquake data in the perspective of dynamical systems and its Pseudo Phase Plane representation. The seismic data is collected from the Bulletin of the International Seismological Centre. The geological events are characterised by their magnitude and geographical location and described by means of time series of sequences of Dirac impulses. Fifty groups of data series are considered, according to the Flinn-Engdahl seismic regions of Earth. For each region, Pearson’s correlation coefficient is used to find the optimal time delay for reconstructing the Pseudo Phase Plane. The Pseudo Phase Plane plots are then analysed and characterised.

Influência dos métodos de correção de atenuação na quantificação da função renal relativa em cintigrafia renal com 99mTc-DMSA

Introdução – A estimativa da função renal relativa (FRR) através de cintigrafia renal (CR) com ácido dimercaptossuccínico marcado com tecnécio-99 metaestável (99mTc-DMSA) pode ser influenciada pela profundidade renal (PR), atendendo ao efeito de atenuação por parte dos tecidos moles que envolvem os rins. Dado que raramente é conhecida esta mesma PR, diferentes métodos de correção de atenuação (CA) foram desenvolvidos, nomeadamente os que utilizam fórmulas empíricas, como os de Raynaud, de Taylor ou de Tonnesen, ou recorrendo à aplicação direta da média geométrica (MG). Objetivos – Identificar a influência dos diferentes métodos de CA na quantificação da função renal relativa através da CR com 99mTc-DMSA e avaliar a respetiva variabilidade dos resultados de PR. Metodologia – Trinta e um pacientes com indicação para realização de CR com 99mTc-DMSA foram submetidos ao mesmo protocolo de aquisição. O processamento foi efetuado por dois operadores independentes, três vezes por exame, variando para o mesmo processamento o método de determinação da FRR: Raynaud, Taylor, Tonnesen, MG ou sem correção de atenuação (SCA). Aplicou-se o teste de Friedman para o estudo da influência dos diferentes métodos de CA e a correlação de Pearson para a associação e significância dos valores de PR com as variáveis idade, peso e altura. Resultados – Da aplicação do teste de Friedman verificaram-se diferenças estatisticamente significativas entre os vários métodos (p=0,000), excetuando as comparações SCA/Raynaud, Tonnesen/MG e Taylor/MG (p=1,000) para ambos os rins. A correlação de Pearson demonstra que a variável peso apresenta uma correlação forte positiva com todos os métodos de cálculo da PR. Conclusões – O método de Taylor, entre os três métodos de cálculo de PR, é o que apresenta valores de FRR mais próximos da MG. A escolha do método de CA influencia significativamente os parâmetros quantitativos de FRR.

Relação entre despesas em saúde e a saúde das populações : análise da base de dados da OCDE 2012

RESUMO - Introdução: A despesa em saúde aumentou consideravelmente nas últimas décadas na maioria dos países industrializados. Por outro lado, os indicadores de saúde melhoraram. A evidência empírica sobre a relação entre as despesas em saúde e a saúde das populações tem sido inconclusiva. Este estudo aborda a relação entre as despesas em saúde e a saúde das populações através de dados agregados para 34 países para o período 1980-2010. Metodologia: Utilizou-se o coeficiente de correlação de Pearson para avaliar a correlação entre as variáveis explicativas e os indicadores de saúde. Procedeuse ainda à realização de uma regressão multivariada com dados em painel para cada indicador de saúde utilizado como variável dependente: esperança de vida à nascença e aos 65 anos para mulheres e homens, anos de vida potencialmente perdidos para mulheres e homens e mortalidade infantil. A principal variável explicativa utilizada foi a despesa em saúde, mas consideraram-se também vários fatores de confundimento, nomeadamente a riqueza, fatores estilo de vida, e oferta de cuidados. Resultados: A despesa per capita tem impacto nos indicadores de saúde mas ao adicionarmos a variável PIB per capita deixa de ser estatisticamente significativa. Outros fatores têm um impacto significativo para quase todos os indicadores de saúde utilizados: consumo de álcool e tabaco, gordura, o número de médicos e a imunização, confirmando vários resultados da literatura. Conclusão: Os resultados vão ao encontro de alguns estudos que afirmam o impacto marginal das despesas em saúde e do progresso da medicina nos resultados em saúde desde os anos 80 nos países industrializados.

The Terroir of Winter Hardiness: Investigation of Winter Hardiness, Water Metrics, and Yield of Riesling and Cabernet Franc in the Niagara Region Using Geomatic Technologies

Grapevine winter hardiness is a key factor in vineyard success in many cool climate wine regions. Winter hardiness may be governed by a myriad of factors in addition to extreme weather conditions – e.g. soil factors (texture, chemical composition, moisture, drainage), vine water status, and yield– that are unique to each site. It was hypothesized that winter hardiness would be influenced by certain terroir factors , specifically that vines with low water status [more negative leaf water potential (leaf ψ)] would be more winter hardy than vines with high water status (more positive leaf ψ). Twelve different vineyard blocks (six each of Riesling and Cabernet franc) throughout the Niagara Region in Ontario, Canada were chosen. Data were collected during the growing season (soil moisture, leaf ψ), at harvest (yield components, berry composition), and during the winter (bud LT50, bud survival). Interpolation and mapping of the variables was completed using ArcGIS 10.1 (ESRI, Redlands, CA) and statistical analyses (Pearson’s correlation, principal component analysis, multilinear regression) were performed using XLSTAT. Clear spatial trends were observed in each vineyard for soil moisture, leaf ψ, yield components, berry composition, and LT50. Both leaf ψ and berry weight could predict the LT50 value, with strong positive correlations being observed between LT50 and leaf ψ values in eight of the 12 vineyard blocks. In addition, vineyards in different appellations showed many similarities (Niagara Lakeshore, Lincoln Lakeshore, Four Mile Creek, Beamsville Bench). These results suggest that there is a spatial component to winter injury, as with other aspects of terroir, in the Niagara region.

Étude pharmacogénomique sur l’utilisation de la warfarine en pratique clinique réelle

Contexte: Bien que plusieurs algorithmes pharmacogénétiques de prédiction de doses de warfarine aient été publiés, peu d’études ont comparé la validité de ces algorithmes en pratique clinique réelle. Objectif: Évaluer trois algorithmes pharmacogénomiques dans une population de patients qui initient un traitement à la warfarine et qui souffrent de fibrillation auriculaire ou de problèmes de valves cardiaques. Analyser la performance des algorithmes de Gage et al., de Michaud et al. ainsi que de l’IWPC quant à la prédiction de la dose de warfarine permettant d’atteindre l’INR thérapeutique. Méthodes: Un devis de cohorte rétrospectif fut utilisé afin d’évaluer la validité des algorithmes chez 605 patients ayant débuté une thérapie de warfarine à l’Institut de Cardiologie de Montréal. Le coefficient de corrélation de Pearson ainsi que l’erreur absolue moyenne ont été utilisés pour évaluer la précision des algorithmes. L’exactitude clinique des prédictions de doses fut évaluée en calculant le nombre de patients pour qui la dose prédite était sous-estimée, idéalement estimée ou surestimée. Enfin, la régression linéaire multiple a été utilisée pour évaluer la validité d’un modèle de prédiction de doses de warfarine obtenu en ajoutant de nouvelles covariables. Résultats : L’algorithme de Gage a obtenu la proportion de variation expliquée la plus élevée (R2 ajusté = 44 %) ainsi que la plus faible erreur absolue moyenne (MAE = 1.41 ± 0.06). De plus, la comparaison des proportions de patients ayant une dose prédite à moins de 20 % de la dose observée a confirmé que l’algorithme de Gage était également le plus performant. Conclusion : Le modèle publié par Gage en 2008 est l’algorithme pharmacogénétique le plus exact dans notre population pour prédire des doses thérapeutiques de warfarine.