Modes de variabilité temporelle des débits moyens annuels et leurs liens avec les indices climatiques au québec (canada)

La variabilité interannuelle des débits moyens annuels (1970-1995) de 70 stations hydrologiques réparties dans les trois grands bassins versants du Québec a été étudiée au moyen d’une analyse en composantes principales et d’un lissage par une moyenne mobile simple. Cinq modes de variabilité ont été ainsi identifiés selon la succession des phases de baisse et de hausse des débits. Les trois premiers modes caractérisent les rivières du bassin du fleuve Saint-Laurent. Le premier mode, qui regroupe le plus grand nombre de stations situées sur les deux rives du fleuve, montre une période de baisse des débits (avant 1980), suivie d’une longue phase de hausse modérée des débits. Ce mode est positivement corrélé à l’oscillation australe. Le second mode, qui regroupe les rivières situées au nord de la rive sud du Saint-Laurent, est caractérisé par des débits qui diminuent entre 1975 et 1985, puis augmentent. Il n’est corrélé à aucun indice climatique. Les stations qui forment le troisième mode sont principalement localisées en rive nord. Ce mode est caractérisé par deux phases de hausse séparées par une phase de baisse des débits. Certaines stations de ce mode sont corrélées aux oscillations arctique, australe et nord atlantique. Les deux derniers modes caractérisent les rivières situées au nord du 55e parallèle, dans les bassins de la Baie d’Ungava et de la Baie d’Hudson. Ces modes montrent une phase de diminution continue depuis la seconde période des années 1970 ou une phase de diminution précédée d’une longue phase normale des débits. Ils sont négativement corrélés à l’oscillation arctique et nord atlantique. Il se dégage de cette étude que la variabilité interannuelle des débits n’est pas synchrone à l’intérieur du bassin du fleuve Saint-Laurent.The temporal variability of the annual average discharges (1970-1995) of 70 hydrological stations distributed among Québec three main watersheds was studied by principal component analysis and smoothing by a simple moving average. Five temporal variability modes were thus identified according to the succession of decreasing and increasing discharge phases. The first three modes characterize rivers of the St. Lawrence watershed. The first mode, which includes the greatest number of stations located on both shores of the river, shows a period of decreasing discharges (before 1980), followed by a long phase of moderately increasing discharges. This mode is positively correlated with the Southern Oscillation. The second mode, which includes rivers located in the northern part of the south shore of the St. Lawrence, is characterized by discharges decreasing between 1975 and 1985 and then increasing. It is not correlated with any climate index. The stations forming the third mode are mainly located on the north shore. This mode is characterized by two increasing phases separated by a decreasing discharge phase. Some stations of this mode are correlated with the Arctic, Southern and North Atlantic Oscillations. The last two modes characterize rivers located north of the 55th parallel, in the Ungava Bay and Hudson Bay watersheds. These modes show a continuously decreasing phase since the second period of the 1970s or a decreasing phase preceded by a long normal discharge phase. They are negatively correlated with the Arctic and North Atlantic Oscillations. This study shows that the interannual discharge variability is not synchronous within the St. Lawrence River watershed

Développement d’une nouvelle méthode de régionalisation basée sur le concept de « régime des débits naturels » : la méthode éco-géographique

Nous proposons une nouvelle méthode de régionalisation des débits fondée sur le concept de « régime des débits naturels » introduit en écologie aquatique : l’approche éco-géographique. Elle se distingue de deux approches de régionalisation existantes (approches hydrologique et écologique) sur les trois points suivants : le choix des variables hydrologiques, l’échelle d’analyse et la finalité de la régionalisation. En ce qui concerne le choix des variables hydrologiques, la nouvelle méthode est fondée sur le choix des caractéristiques des débits et non sur les variables hydrologiques. Ces caractéristiques des débits sont définies au moyen de l’analyse en composantes principales appliquée sur les variables hydrologiques. Contrairement aux autres approches, l’approche éco-géographique tient compte de toutes les caractéristiques des débits dans la régionalisation conformément au concept de « régime des débits naturels ». Quant à l’échelle d’analyse, à l’instar de l’approche écologique, la nouvelle méthode s’applique aussi à toutes les échelles d’analyse (annuelle, mensuelle et journalière) mais en les considérant séparément afin de tenir compte de toutes les caractéristiques de débits dans la régionalisation. Enfin, la finalité de la nouvelle méthode est de pouvoir déterminer les facteurs de variabilité spatiale des caractéristiques de débits (et non des variables hydrologiques) au moyen de l’analyse canonique des corrélations, notamment afin d’assurer une gestion durable des ressources hydriques dans un contexte de changement de l’environnement. Nous avons appliqué cette nouvelle méthode aux débits moyens annuels au Québec.Flow regionalization has been the subject of numerous hydrologic studies. However, despite the development of regionalization methods, there are still differences in the approaches used amongst hydrologists on the one hand, and between hydrologists and experts in other fields (aquatic ecology and physical geography) on the other hand. Those differences relate to five aspects of the regionalization process: the choice of hydrologic variables, station grouping methods to produce homogeneous hydrologic regions, the choice of appropriate statistical laws to estimate quantiles for non-gauged or partially-gauged sites, the scale of flow analysis, and the ultimate purpose of the regionalization exercise. Depending on the choice of hydrologic variables, the scale of analysis and their ultimate purpose, regionalization studies may thus be divided according to two distinct approaches: the hydrologic approach and the ecologic approach.The ultimate purpose of the hydrologic approach is to estimate flows at non-gauged or partially-gauged sites. For this reason, it has been primarily concerned with methods that allow the grouping of stations into homogeneous hydrologic regions and with the choice of statistical laws to estimate quantiles for non-gauged or partially-gauged sites. However, despite its undeniable interest from a practical point of view, this approach does not address the concerns of ecologists and geographers for three reasons: 1) the choice of hydrologic variables used for regionalization is not based on a scientific concept (this choice is arbitrary, and the variables selected do not constrain all the flow characteristics); 2) the ultimate purpose of the regionalization exercise is limited to estimating flows and is of limited interest to geographers and ecologists; 3) regionalization is performed at a daily scale, without taking into account other scales.To make up for these limitations, ecologists have recently proposed regionalization based on the “natural flow regime” concept (the ecologic approach), which allows all fundamental flow characteristics (magnitude, frequency, duration, timing of occurrence and variability) to be taken into account. The rationale for considering all flow characteristics is that each characteristic has an effect on the behaviour of river ecosystems. Hence, regionalization based on the ecologic approach relies on a large number of hydrologic variables that define the fundamental flow characteristics. Rather than being arbitrary, the choice of variable is based on this new paradigm. Regionalization using the ecologic approach considers all time scales, and its ultimate purpose is to account for differences in the structure and biological composition of aquatic ecosystems.However, one of the limitations of studies based on this approach is that, no matter how numerous they are, the variables used for regionalization do not constrain all flow characteristics, as required by the natural flow regime concept, so that application of this concept is incomplete. In addition, simultaneous analysis of all time scales does not allow consideration of all flow characteristics. To overcome these limitations, we propose a new regionalization approach based on the natural flow regime concept, an “ecogeographic” approach that differs from the ecologic approach in three ways. First, the proposed method is based on the use of flow characteristics rather than hydrologic variables. The reason for this is that there are an infinite number of hydrologic variables to define the five fundamental characteristics, making it impossible to account for all of them in the regionalization process. In contrast, since the number of fundamental flow characteristics is limited, they can all be taken into account, consistent with the “natural flow regime” requirements. Second, the ultimate purpose of the proposed regionalization method is to identify the physiographic and climatic factors that explain the spatial variability of these fundamental characteristics. To achieve this goal, it is necessary to analyze the different time scales (daily, monthly, annual) separately given the fact that it is impossible to constrain the effect of these various physiographic and climatic factors at all time scales. Indeed, some factors may show an effect at some time scales and not at others. This ultimate purpose addresses the concerns of geographers interested in explaining the spatial variability of such phenomena, among other things. Finally, separate analysis of the various time scales makes it possible to define all flow characteristics linked to a given time scale. As such, application of the “natural flow regime” concept to regionalization is complete.Application of the ecogeographical method involves four separate steps: 1) the definition of the flow characteristics for the hydrologic series of interest; 2) the determination of minor and major characteristics using principal component analysis, where a “major” flow characteristic is defined as one which meets the following criterion: TVE ≥ (100% / N), where N is the total number of characteristics that define the analyzed hydrologic series and TVE is the total variance explained; 3) the grouping of stations in homogeneous hydrologic regions based on factorial scores. Homogeneous hydrologic regions are divided in two types based on the presence or absence of stations: effective homogeneous regions contain stations whereas fictive homogenous regions do not; 4) the determination of the factors that affect the spatial variability of flow characteristics. This is achieved using canonical correlation analysis, an approach that we have applied to average annual flows in Quebec watersheds

The learners\u27 perspective on internal medicine ward rounds: a cross-sectional study

Background: Ward rounds form an integral part of Internal Medicine teaching. This study aimed to determine the trainees\u27 opinions regarding various aspects of their ward rounds, including how well they cover their learning needs, how they would like the rounds to be conducted, and differences of opinion between medical students and postgraduates. Methods: A cross-sectional study was conducted on a total of 134 trainees in Internal Medicine, comprising medical students, interns, residents and fellows, who were asked to fill in a structured, self-designed questionnaire. Most of the responses required a rating on a scale of 1-5 (1 being highly unsatisfactory and 5 being highly satisfactory). Results: Teaching of clinical skills and bedside teaching received the lowest overall mean score (Mean +/- SD 2.48 +/- 1.02 and 2.49 +/- 1.12 respectively). They were rated much lower by postgraduates as compared to students (p \u3c 0.001). All respondents felt that management of Patients was the aspect best covered by the current ward rounds (Mean +/- SD 3.71 +/- 0.72). For their desired ward rounds, management of Patients received the highest score (Mean +/- SD 4.64 +/- 0.55), followed by bedside examinations (Mean +/- SD 4.60 +/- 0.61) and clinical skills teaching (Mean +/- SD 4.50 +/- 0.68). The postgraduates desired a lot more focus on communication skills, counselling and medical ethics as compared to students, whose primary focus was teaching of bedside examination and management. A majority of the respondents (87%) preferred bedside rounds over conference room rounds. Even though the duration of rounds was found to be adequate, a majority of the trainees (68%) felt there was a lack of individual attention during ward rounds. Conclusions: This study highlights important areas where ward rounds need improvement in order to maximize their benefit to the learners. There is a need to modify the current state of ward rounds in order to address the needs and expectations of trainees

Six-Minute Walk Test Performance in Healthy Adult Pakistani Volunteers

Objective: To determine the six-minute walking distance (6MWD) for healthy Pakistanis, identify factors affecting 6MWD, compare published equations with the local data and derive an equation. Study Design: Cross-sectional study. Place and Duration of Study: Two medical institutes of Karachi, from January to May 2011. Methodology: Subjects between 15 and 65 years were prospectively enrolled after screening. A standardized 6MWT was administered. SpO2, HR, BP and dyspnoea scores were determined pre- and post-test. Results: Two hundred and eleven (71%) men and 85 (29%) women participated. Mean 6MWD was 469.88 ± 101.24 m: men walked 502.35 ± 92.21 m and women walked 389.28 ± 74.29 m. On univariate analysis, gender, height, weight and age showed a significant relationship with the 6MWD. Gender and age were identified as independent factors in multiple regression analysis, and together explained 33% of the variance. The gender-specific prediction equations were: 6MWD (m) for men = 164.08 + (78.06*1) - (1.90*age in years) + (1.95*height in cms) 6MWD (m) for women = 164.08 - (1.90*age in years) + (1.95*height in cms). Conclusion: 6MWDs among the volunteer subjects were shorter than predicted by reference equations in literature. Height, gender and weight combined explained 33% of the variance. The moderate over-estimation of the 6MWD in Pakistani subject. The proposed equation gives predicted (mean) 6MWDs for adult Pakistani naïve to the test when employing standardized protocol

Оцінка якості розв'язку обернених задач геофізики на основі застосування статистичного критерію хі-квадрат

Повышение эффективности поисково-разведочных работ на нефть и газ возможно на пути развития интерпретационных систем, основанных на решении обратных задач геофизики. Наличие случайных погрешностей в измеряемых геофизических полях, а также существенная некорректность решения обратных задач геофизики делают актуальной проблему независимой оценки качества решения получаемого в результате реализации итерационного подбора. Предложено контролировать качество решения обратной задачи на основе использования критерия хи-квадрат оценки гипотезы о нормальности закона распределения остаточной невязки между наблюденным и рассчитанным геофизическими полями. Эффективность использования статистического критерия хи-квадрат для оценки качества решения обратной задачи гравиметрии проиллюстрирована практическим примеромEnhancement of the efficiency of oil and gas exploration work is possible while heading toward the development of interpretation systems, which are based on the geophysical inverse problems solutions. Presence of the random uncertainties in measured geophysical fields, as well as considerable ill-posed of the solutions of inverse problems of geophysical data make it an actual problem of independent estimation of the quality of the solution which is obtained as an outcome of realization of the iterative process. It is proposed to control the quality of the solution of the inverse problem on basis of the XI-square criterion use for assessment of the hypothesis of normalcy of distribution law of the residual discrepancy between observed and calculated geophysical fields. In the practical view the efficiency of the use of statistical estimation of the quality of the solution of the inverse problem of gravimetry was shown

Clinical characteristics and predictors of positive stool culture in adult patients with acute gastroenteritis

OBJECTIVE: To identify the presenting features and spectrum of pathogens in adult patients with acute diarrhoea and to determine the predictors of stool culture positivity. METHODS: A descriptive study was conducted in a tertiary care hospital from April 1, 2005 to March 31, 2006. Medical records of all consecutive adult patients with history of acute diarrhoea were reviewed between June 2006 to December 2006 for clinical characteristics and laboratory investigations. RESULTS: A total of 454 patients were admitted from April 1, 2005 to March 31, 2006. Stool cultures were performed in 233 (50%) patients, 96 (42%) had positive results. Patients with positive stool culture compared to a negative Culture were found to have a younger mean age (43 vs. 53), greater number of unformed stools (16 vs. 11) and low serum bicarbonate level (16 vs. 20). Vibrio cholerae (86%) was found to be the most prevalent organism followed by Salmonella spp (6%), Campylobacter spp (5.2%), Shigella spp (2%). Ciprofloxacin was given to 97% patients along with fluid administration, and 78% were found to be resistant to quinolones. Most patients recovered before the finalized stool culture results. CONCLUSION: Careful selection of the patients based on their clinical presentation and initial laboratory work up can help to decide ordering of stool culture in adults with diarrhoea. Fluid resuscitation remains the main stay of treatment

Ethical leadership and firms’ sustainability: mediating role of corporate social responsibility in Pakistan’s banking sector

The sustainability of businesses has emerged as a pressing concern in the competitive landscape. To tackle this issue, the present study aims to explore the role of ethical leadership in determining the sustainability of private banking institutions in Pakistan, with corporate social responsibility (CSR) serving as the mediator. The research utilized data from 232 middle and upper-level private bank employees in Pakistan. The statistical tools SPSS and SmartPLS were employed for data analysis, and a structural equation model was used to test the study hypotheses. The findings indicate a positive and significant impact of ethical leadership on firms\u27 sustainability. Furthermore, CSR significantly and positively mediates the relationship between ethical leadership and firms\u27 sustainability. This study provides valuable insights into the fields of organizational behavior, leadership, and sustainable business practices. The results shed light on the mechanisms through which ethical leadership influences CSR practices and the sustainability of private banking institutions in Pakistan. The study has implications for policymakers, practitioners, and academic researchers to promote sustainable and socially responsible business practices in the private banking sector of Pakistan

Poboljšanje tehnoloških svojstava i terapeutskog potencijala kus-kusa dodatkom tradicijskog preparata Issoufera: tradicionalna biljna medicina

Enrichment of food is a strategy to reduce the incidence of deficiencies in micronutrients in a population. Couscous is widely consumed in Algeria, thus the objective of this study was to obtain an enriched couscous with enhanced therapeutic potencies and with good physicochemical, technological, and microbiological characteristics. Three mass ratios of the traditional preparation Issoufer (10, 20, and 30 %) were added to wheat couscous, and then compared with a control couscous made 100 % of semolina. A significant (p < 0.05) increase was noticed in the ash, proteins, lipids, carbohydrates, phenolic compounds, flavonoids, and anti-radical activity values, for all the mass ratios of Issoufer powder. In contrast, the moisture and pH-value revealed a significant (p < 0.05) decrease in Issoufer powder. The acute toxicity study revealed no lethal effects and behavioural signs of toxicity at the tested doses (100, 250, 500, and 750 mg kg–1) of the extract of Issoufer during the 5 days of observation. The results of antibacterial activity showed diameters of inhibition zones had achieved 29.90±0.60 mm. Based on obtained results, Issoufer powder can be considered a good ingredient to develop functional couscous naturally enriched of secondary metabolites, and can be used in the prevention of several diseases, as well as used in the food industry.Obogaćivanje hrane je način da se smanji učestalost nedostataka mikronutrijenata u populaciji. Kus-kus je namirnica koja se u Alžiru konzumira u velikoj mjeri. Stoga je cilj ovog istraživanja bio dobiti obogaćeni kus-kus s poboljšanim terapeutskim potencijalom i dobrim fizikalno-kemijskim, tehnološkim i mikrobiološkim karakteristikama. Pšeničnom kus-kusu dodan je tradicionalni pripravak Issoufer (10, 20 i 30 %), te je smjesa uspoređena s kontrolnom čistom kus-kus krupicom. Znatno povećanje (p < 0,05) pepela, proteina, lipida, ugljikohidrata, fenolnih spojeva, flavonoida i anti-radikalne aktivnosti, zabilježeno je kod svih smjesa s dodanim Issoufer pripravkom. S druge strane, znatno (p < 0,05) su se smanjili udio vlage te pH-vrijednost. Studija akutne toksičnosti nije pokazala smrtonosne učinke i znakove toksičnosti pri ispitanim dozama ekstrakta Issoufera (100, 250, 500 i 750 mg kg–1) tijekom pet dana promatranja. Rezultati antibakterijske aktivnosti pokazali su da su promjeri zona inhibicije dosegli vrijednost od 29,90 ± 0,60 mm. Na temelju dobivenih rezultata, Issoufer prah može se smatrati dobrim sastojkom za razvoj funkcionalnog kus-kusa prirodno obogaćenog sekundarnim metabolitima te se može upotrebljavati za prevenciju više bolesti, ali i u prehrambenoj industriji

The use of folic acid in dengue: Has it any value?

Folic acid is used in dengue patients. Our study aims to compare the duration of recovery of thrombocytopenia in patients with dengue infection who received folic acid and those who did not. We retrospectively reviewed the medical records of adult patients admitted over six years with a diagnosis of dengue. Of 2216 patients, 1464 fulfilled the inclusion criteria. Group A were those patients who received folic acid and group B were those who did not. A total of 1322 (90.3%) patients received folic acid. The mean time period required for platelets to double the nadir was 1.7 (±2.2) days in both groups A and B ( P = 0.89). In conclusion, there is no significant difference in the recovery of thrombocytopenia in patients with dengue fever who received folic and those who did not receive folic acid