Quality Variables (quality + variable)

Distribution by Scientific Domains

Kinds of Quality Variables

  • water quality variable


  • Selected Abstracts


    Effect of Hormone Replacement Therapy on Bone Quality in Early Postmenopausal Women

    JOURNAL OF BONE AND MINERAL RESEARCH, Issue 6 2003
    Ep Paschalis PhD
    Abstract HRT is an effective prophylaxis against postmenopausal bone loss. Infrared imaging of paired iliac crest biopsies obtained at baseline and after 2 years of HRT therapy demonstrate an effect on the mineral crystallinity and collagen cross-links that may affect bone quality. Several studies have demonstrated that hormonal replacement therapy (HRT) is an effective prophylaxis against postmenopausal bone loss, although the underlying mechanisms are still debated. Infrared spectroscopy has been used previously for analyzing bone mineral crystallinity and three-dimensional structures of collagen and other proteins. In the present study, the technique of Fourier transform infrared microscopic imaging (FTIRI) was used to investigate the effect of estrogen on bone quality (arbitrarily defined as mineral/matrix ratio, mineral crystallinity/maturity, and relative ratio of collagen cross-links [pyridinoline/deH-DHLNL]) at the ultrastructural level, in mineralized, thin tissue sections from double (before and after administration of HRT regimen; cyclic estrogen and progestogen [norethisterone acetate]) iliac crest biopsy specimens from 10 healthy, early postmenopausal women who were not on any medication with known influence on calcium metabolism. FTIRI allows the analysis of undemineralized thin tissue sections (each image analyzes a 400 × 400 ,m2 area with a spatial resolution of ,6.3 mm). For each bone quality variable considered, the after-treatment data exhibited an increase in the mean value, signifying definite changes in bone properties at the molecular level after HRT treatment. Furthermore, these findings are consistent with suppressed osteoclastic activity. [source]


    Nonparametric harmonic regression for estuarine water quality data

    ENVIRONMETRICS, Issue 6 2010
    Melanie A. Autin
    Abstract Periodicity is omnipresent in environmental time series data. For modeling estuarine water quality variables, harmonic regression analysis has long been the standard for dealing with periodicity. Generalized additive models (GAMs) allow more flexibility in the response function. They permit parametric, semiparametric, and nonparametric regression functions of the predictor variables. We compare harmonic regression, GAMs with cubic regression splines, and GAMs with cyclic regression splines in simulations and using water quality data collected from the National Estuarine Reasearch Reserve System (NERRS). While the classical harmonic regression model works well for clean, near-sinusoidal data, the GAMs are competitive and are very promising for more complex data. The generalized additive models are also more adaptive and require less-intervention. Copyright © 2009 John Wiley & Sons, Ltd. [source]


    A simulation tool for designing nutrient monitoring programmes for eutrophication assessments,

    ENVIRONMETRICS, Issue 1 2010
    Janet Heffernan
    Abstract This paper describes a simulation tool to aid the design of nutrient monitoring programmes in coastal waters. The tool is developed by using time series of water quality data from a Smart Buoy, an in situ monitoring device. The tool models the seasonality and temporal dependence in the data and then filters out these features to leave a white noise series. New data sets are then simulated by sampling from the white noise series and re-introducing the modelled seasonality and temporal dependence. Simulating many independent realisations allows us to study the performance of different monitoring designs and assessment methods. We illustrate the approach using total oxidised nitrogen (TOxN) and chlorophyll data from Liverpool Bay, U.K. We consider assessments of whether the underlying mean concentrations of these water quality variables are sufficiently low; i.e. below specified assessment concentrations. We show that for TOxN, even when mean concentrations are at background, daily data from a Smart Buoy or multi-annual sampling from a research vessel would be needed to obtain adequate power. Copyright © 2009 Crown Copyright [source]


    Constrained multivariate trend analysis applied to water quality variables

    ENVIRONMETRICS, Issue 1 2002
    D. M. Cooper
    Abstract Constrained multivariate regression analysis is used to model trends and seasonal effects in time series measurements of water quality variables. The constraint used ensures that when identifying trends the scientifically important charge balance of model-fitted concentrations is maintained, while accounting for between variable dependencies. The analysis is a special case of linear reduction of dimensionality which preserves the integrity of a subset of the original variables, while allowing the remainder to be identified as linear combinations of this subset. The technique is applied to water quality measurements made at the outflow from Loch Grannoch, an acid-sensitive loch in Scotland. A reduction in marine ion concentrations is observed in water samples collected four times a year over the period 1988,2000. This is identified with long term variability in the marine component in rainfall. Separation of the non-marine component of the solute load shows a reduction in non-marine sulphate and calcium concentrations, and an increase in the non-marine sodium concentration. There is no significant change in either alkalinity or acid neutralizing capacity over the period. The reduction in non-marine sulphate is consistent with reductions in atmospheric inputs of sulphate. However, the reduction in sulphate has not been accompanied by a reduction in the acidity of water samples from Loch Grannoch, but with a reduction in calcium concentration and an apparent increase in organic acids, as evidenced by increased dissolved organic carbon concentrations, with possible increases in nitrate and non-marine sodium concentrations. Copyright © 2002 John Wiley & Sons, Ltd. [source]


    Metamorphosis offsets the link between larval stress, adult asymmetry and individual quality

    FUNCTIONAL ECOLOGY, Issue 2 2008
    M. Campero
    Summary 1It is poorly understood which traits translate larval stressors into adult fitness in animals where larval and adult stages are separated by metamorphosis. Although fluctuating asymmetry (FA) is often assumed to do so, especially in insects the relationship between larval stress, adult FA and individual quality is often absent. One suggested hypothesis for this is the higher mortality of low quality (hence more asymmetric) animals during metamorphosis (i.e. developmental selection hypothesis). 2Here we test this hypothesis and also propose and test an alternative hypothesis where metamorphosis is stressful but not lethal and increases FA of all animals up to a certain level (i.e. stressful metamorphosis hypothesis). 3We manipulated larval stress (food stress and pesticide stress) and measured FA before and after metamorphosis in the damselfly Coenagrion puella. Additionally, we assessed the relationship between FA and individual quality variables measured at metamorphosis (age, mass and two immune variables: phenoloxidase (PO) and haemocyte number). 4Before metamorphosis, FA reflected the combination of food and pesticide stress and was negatively related with mass and both immune variables after metamorphosis. These patterns were, however, offset after metamorphosis. Low mortality, not linked to FA during metamorphosis, indicates that developmental selection cannot explain this. Instead, the strong increase in FA up to equal levels across treatments during metamorphosis supports the stressful metamorphosis hypothesis. 5Taken together, the developmental stage in which FA is measured may critically determine the reliability of FA as an indicator of stress and of individual quality in insects. [source]


    Do elevated atmospheric CO2 and O3 affect food quality and performance of folivorous insects on silver birch?

    GLOBAL CHANGE BIOLOGY, Issue 3 2010
    PETRI A. PELTONEN
    Abstract The individual and combined effects of elevated CO2 and O3 on the foliar chemistry of silver birch (Betula pendula Roth) and on the performance of five potential birch-defoliating insect herbivore species (two geometrid moths, one lymantrid moth and two weevils) were examined. Elevated CO2 decreased the water concentration in both short- and long-shoot leaves, but the effect of CO2 on the concentration of nitrogen and individual phenolic compounds was mediated by O3 treatment, tree genotype and leaf type. Elevated O3 increased the total carbon concentration only in short-shoot leaves. Bioassays showed that elevated CO2 increased the food consumption rate of juvenile Epirrita autumnata and Rheumaptera hastata larvae fed with short- and long-shoot leaves in spring and mid-summer, respectively, but had no effect on the growth of larvae. The contribution of leaf quality variables to the observed CO2 effects indicate that insect compensatory consumption may be related to leaf age. Elevated CO2 increased the food preference of only two tested species: Phyllobius argentatus (CO2 alone) and R. hastata (CO2 combined with O3). The observed stimulus was dependent on tree genotype and the measured leaf quality variables explained only a portion of the stimulus. Elevated O3 decreased the growth of flush-feeding young E. autumnata larvae, irrespective of CO2 concentration, apparently via reductions in general food quality. Therefore, the increasing tropospheric O3 concentration could pose a health risk for juvenile early-season birch folivores in future. In conclusion, the effects of elevated O3 were found to be detrimental to the performance of early-season insect herbivores in birch whereas elevated CO2 had only minor effects on insect performance despite changes in food quality related foliar chemistry. [source]


    Does Prospective Payment Really Contain Nursing Home Costs?

    HEALTH SERVICES RESEARCH, Issue 2 2002
    Li-Wu Chen
    Objective. To examine whether nursing homes would behave more efficiently, without compromising their quality of care, under prospective payment. Data Sources. Four data sets for 1994: the Skilled Nursing Facility Minimum Data Set, the Online Survey Certification and Reporting System file, the Area Resource File, and the Hospital Wage Indices File. A national sample of 4,635 nursing homes is included in the analysis. Study Design. Using a modified hybrid functional form to estimate nursing home costs, we distinguish our study from previous research by controlling for quality differences (related to both care and life) and addressing the issues of output and quality endogeneity, as well as using more recent national data. Factor analysis was used to operationalize quality variables. To address the endogeneity problems, instrumental measures were created for nursing home output and quality variables. Principal Findings. Nursing homes in states using prospective payment systems do not have lower costs than their counterpart facilities under retrospective cost-based payment systems, after quality differences among facilities are controlled for and the endogeneity problem of quality variables is addressed. Conclusions. The effects of prospective payment on nursing home cost reduction may be through quality cuts, rather than cost efficiency. If nursing home payments under prospective payment systems are not adjusted for quality, nursing homes may respond by cutting their quality levels, rather than controlling costs. Future outcomes research may provide useful insights into the adjustment of quality in the design of prospective payment for nursing home care. [source]


    Assessing the effects of hydromorphological degradation on macroinvertebrate indicators in rivers: examples, constraints, and outlook

    INTEGRATED ENVIRONMENTAL ASSESSMENT AND MANAGEMENT, Issue 1 2009
    Nikolai Friberg
    Abstract An extensive amount of literature on linkages between the in-stream physical environment and river benthic macroinvertebrates reports a number of relationships across multiple spatial scales. We analyzed data on different spatial scales to elucidate the linkages between different measurements of hydromorphological degradation and commonly used macroinvertebrate indices. A regression analysis of 1049 sites from 3 countries revealed that the strongest relationship between a biotic metric,average score per taxon,and physiochemical variables (R2 = 0.61) was obtained with a multiple regression model that included concentration of total phosphorus and percent arable land in the catchment, as well as hydromorphological quality variables. Analyses of 3 data sets from streams primarily affected by hydromorphological degradation showed an overall weak relationship (max R2 = 0.25) with the River Habitat Survey data of 28 Swedish streams, whereas moderate (R2 , 0.43) relationships with more detailed measurements of morphology were found in 2 Danish studies (39 and 6 streams, respectively). Although evidence exists in the literature on the importance of physical features for in-stream biota in general and macroinvertebrates specifically, we found only relatively weak relationships between various measures of hydromorphological stress and commonly used macroinvertebrate assessment tools. We attribute this to a combination of factors, including 1) the mixed nature of pressures acting on the majority of river reaches, 2) scaling issues (spatial and temporal) when relating habitat surveys to macroinvertebrate assessments, and 3) the scope of commonly used macroinvertebrate assessment systems (mainly focusing on water chemistry perturbation, such as eutrophication and acidification). The need is urgent to develop refined and updated biological assessment systems targeting hydromorphological stress for the use of the European Water Framework Directive (WFD) and national water-related policies. [source]


    Audit Quality, Corporate Governance, and Earnings Management: A Meta-Analysis

    INTERNATIONAL JOURNAL OF AUDITING, Issue 1 2010
    Jerry W. Lin
    Earnings management is of great concern to corporate stakeholders. While numerous studies have investigated the effects of various corporate governance and audit quality variables on earnings management, empirical evidence is rather inconsistent. This meta-analysis identifies 12 significant relationships by integrating results from 48 prior studies. For corporate governance, the independence of the board of directors and its expertise have a negative relationship with earnings management. Similar negative relationships exist between earnings management and the audit committee's independence, its size, expertise, and the number of meetings. The audit committee's share ownership has a positive effect on earnings management. For audit quality, auditor tenure, auditor size, and specialization have a negative relationship with earnings management. Auditor independence, as measured by fee ratio and total fee, is also a deterrent to earnings management. [source]


    Do radiologists agree on the quality of computed tomography enterography?

    JOURNAL OF MEDICAL IMAGING AND RADIATION ONCOLOGY, Issue 4 2009
    Kari Ersland
    Summary This study aimed to assess variation between radiologists evaluating the quality of multi-detector computed tomography enterography. For 40 consecutive examinations, three experienced radiologists independently rated the following quality variables: % length of adequately filled bowel, bowel lumen diameters, bowel wall delineation, superior mesenteric vein, and bowel wall enhancement, artefacts, and total quality. We calculated the mean difference between observers with standard deviation (SD) for continuous variables and % total agreement, exact Fleiss kappa, and P -values (McNemar's test) for categorical variables. Depending on bowel segment (duodenum distal to bulb, jejunum, ileum, terminal ileum), mean difference between observers ranged from two to 33 (SD from 11 to 32) for % length of adequately filled bowel judged subjectively, 0,2 (SD 0,3) mm for smallest bowel lumen diameter and 0,4 (SD 3,7) mm for largest bowel lumen diameter. Agreement on bowel wall delineation was 80%/kappa 0.50 in duodenum, 90%/kappa 0.57 in jejunum, 75%/kappa 0.14 in ileum and 88%/kappa 0.17 in terminal ileum, where ratings differed between observers (P < 0.04). Agreement was 65%/kappa 0.18 for bowel wall enhancement judged subjectively. For contrast enhancement measured in Hounsfield Units, mean difference between observers ranged from two to 11 (SD 12,15) in normal jejunum wall and zero to one (SD 4,5) in the superior mesenteric vein depending on observer pair. Agreement was 78%/kappa 0.12 for image artefacts. Rating of total examination quality (good/optimal versus poor/very poor) differed between observers (P < 0.01); agreement was 60%/kappa 0.41. Many subjective evaluations varied between observers. We believe that measurements of bowel lumen diameters and contrast enhancement may be preferable. [source]


    Monitoring of batch processes through state-space models

    AICHE JOURNAL, Issue 6 2004
    Jay H. Lee
    Abstract The development of a state-space framework for monitoring batch processes that can complement the existing multivariate monitoring methods is presented. A subspace identification method will be used to extract the dynamic and batch-to-batch trends of the process and quality variables from historical operation data in the form of a "lifted" state-space stochastic model. A simple monitoring procedure can be formed around the state and residuals of the model using appropriate scalar statistical metrics. The proposed state-space monitoring framework complements the existing multivariate methods like the multi-way PCA method, in that it allows us to build a more complete statistical representation of batch operations and use it with incoming measurements for early detection of not only large, abrupt changes but also subtle changes. In particular, it is shown to be effective for detecting changes in the batch-to-batch correlation structure, slow drifts, and mean shifts. Such information can be useful in adapting the prediction model for batch-to-batch control. The framework allows for the use of on-line process measurements and/or off-line quality measurements. When both types of measurements are used in model building, one can also use the model to predict the quality variables based on incoming on-line measurements and quality measurements of previous batches. © 2004 American Institute of Chemical Engineers AIChE J, 50: 1198,1210, 2004 [source]


    Stream Condition in Piedmont Streams with Restored Riparian Buffers in the Chesapeake Bay Watershed,

    JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 3 2010
    Leslie L. Orzetti
    Orzetti, Leslie L., R. Christian Jones, and Robert F. Murphy, 2010. Stream Condition in Piedmont Streams with Restored Riparian Buffers in the Chesapeake Bay Watershed. Journal of the American Water Resources Association (JAWRA) 46(3):473-485. DOI: 10.1111/j.1752-1688.2009.00414.x Abstract:, This study tested the efficacy of restored forest riparian buffers along streams in the Chesapeake Bay watershed by examining habitat, selected water quality variables, and benthic macroinvertebrate community metrics in 30 streams with buffers ranging from zero to greater than 50 years of age. To assess water quality we measured in situ parameters (temperature, dissolved oxygen, and conductivity) and laboratory-analyzed grab samples (soluble reactive phosphorus, total phosphorus, nitrate, ammonium, and total suspended solids). Habitat conditions were scored using the Environmental Protection Agency Rapid Bioassessment Protocols for high gradient streams. Benthic macroinvertebrates were quantified using pooled riffle/run kick samples. Results showed that habitat, water quality, and benthic macroinvertebrate metrics generally improved with age of restored buffer. Habitat scores appeared to stabilize between 10 and 15 years of age and were driven mostly by epifaunal substrate availability, sinuosity, embeddedness, and velocity depth regime. Benthic invertebrate taxa richness, percent Ephemeroptera, Plecoptera, Trichoptera minus hydropsychids (%EPT minus H), % Ephemeroptera, and the Family Biotic Index were among the metrics which improved with age of buffer zone. Results are consistent with the hypothesis that forest riparian buffers enhance instream habitat, water quality, and resulting benthic macroinvertebrate communities with noticeable improvements occurring within 5-10 years postrestoration, leading to conditions approaching those of long established buffers within 10-15 years of restoration. [source]


    IMPACT ASSESSMENT MODEL FOR CLEAR WATER FISHES EXPOSED TO EXCESSIVELY CLOUDY WATER,

    JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 3 2003
    Charles P. Newcombe
    ABSTRACT: A new type of empirical model described here enables real time assessment of impacts caused by excessive water cloudiness as a function of (a) reduced visual clarity (excessive cloudiness) and (b) duration of exposure to cloudy conditions, in fisheries or fish life stages adapted to life in clear water ecosystems. This model takes the familiar form used in earlier suspended sediment dose effect models where z is severity of ill effect (SEV), x is duration of exposure (h), y is black disk sighting range (y BD, m),a measure of water clarity, a is the intercept, and b and c are slope coefficients. As calibrated in this study the model is Severity of ill effect is ranked on a 15-step scale that ranges from 0 to 14, where zero represents nil effect and 14 represents 100 percent mortality. This model, based on peer consultation and limited meta analysis of peer reviewed reports, accomplishes the following: (a) identifies the threshold of the onset of ill effects among clear water fishes; (b) postulates the rate at which serious ill effects are likely to escalate as a function of reduced visual clarity and persistence; (c) provides a context (the "visual clarity" matrix, with its cell coordinates) to share and compare information about impacts as a function of visual clarity "climate" (d) demonstrates changes in predator prey interactions at exposures greater than and less than the threshold of direct ill effects; (e) calibrates trout reactive distance (cm) as function of water clarity in the form where y represents reactive distance (cm) and x represents visual clarity (black disk sighting range, cm), and where a and b are intercept and slope respectively, such that (f) identifies black disk sighting range, in meters, and its reciprocal, beam attenuation, as preferred monitoring variables; and (g) provides two additional optical quality variables (Secchi disk extinction distance and turbidity) which, suitably calibrated as they have been in this study, expand the range of monitoring options in situations in which the preferred technology,beam attenuation equipment or black disk sighting equipment,is unavailable or impractical to use. This new model demonstrates the efficacy of peer collaboration and defines new research horizons for its refinement. [source]


    Seasonal patterns of sucrose concentration in relation to other quality parameters of sugar beet (Beta vulgaris L.)

    JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 1 2006
    Christine Kenter
    Abstract The chemical composition of sugar beet is the most important parameter affecting its processing. Sugar factories require beet with high concentrations of sucrose and low concentrations of melassigenic substances to maximise the amount of extractable sugar. In order to plan the processing campaign, forecasts of root and sugar yield by prediction models are possible but there are no means to predict the technical quality of the beet. In the present study, the seasonal development and physiological relationships of different parameters of sugar beet quality were analysed. In order to estimate possibilities for quality forecasts, the concentrations of beet quality variables in October were correlated with corresponding quality measurements in late summer and to weather variables during the growing season by linear regressions. In 2000 and 2001, 27 field trials were conducted on commercial farm fields in all sugar beet growing areas in Germany. From June to October, sequential samples were taken every 4 weeks and the concentrations of sucrose, potassium, sodium, total soluble nitrogen, ,-amino nitrogen, nitrate, betaine, reducing sugars and marc in the beet were determined. The sucrose concentration increased progressively until the final harvest date in autumn, whereas the concentrations of the melassigenic substances decreased markedly until late summer and remained fairly constant as the season progressed. Marc concentration was the most stable of the parameters analysed. The sucrose concentration was positively correlated with the concentrations of dry matter, betaine and marc, but negatively with nitrate concentration and leaf yield throughout the season. The correlation between the concentrations of sucrose and nitrogenous compounds measured in summer and their final concentrations in autumn was rather weak. However, it was close for potassium, sodium and marc and a satisfactory prediction of their final concentrations was possible by the end of August. Based on weather data, beet quality was not predictable. Therefore, it seems to be difficult to integrate beet quality parameters into prediction models. Copyright © 2005 Society of Chemical Industry [source]


    Effect of Multiple-batch Channel Catfish, Ictalurus punctatus, Stocking Density and Feeding Rate on Water Quality, Production Characteristics, and Costs

    JOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 4 2006
    Brent E. Southworth
    To quantitatively define relationships among stocking densities, feeding rates, water quality, and production costs for channel catfish, Ictalurus punctatus, grown in multiple-batch systems, twelve 0.1-ha earthen ponds were stocked at 8,600, 17,300, 26,000, or 34,600 fingerlings/ha along with 2,268 kg/ha of carryover fish. Fish in all ponds were fed daily to apparent satiation using 32% protein floating feed. Temperature and dissolved oxygen in each pond were monitored twice daily; pH weekly; nitrite-N, total ammonia nitrogen, and Secchi disk visibility every 2 wk; nitrate-N, chlorophyll a, total nitrogen, total phosphorus, and chemical oxygen demand monthly; and chloride every other month. The costs of producing channel catfish at different stocking densities were estimated. There were no significant differences (P > 0.05) as a result of stocking density among treatment means of (1) gross or net yields, (2) mean weights at harvest, and (3) growth or survival of fingerlings (24,36%) and carryover fish (77,94%). Mean and maximum daily feeding rates ranged from 40 to 53 kg/ha/d and 123 to 188 kg/ha/d, respectively, and feed conversion ratios averaged 1.75. There were no differences in any feed-related parameter as a result of density. Water quality variables showed few differences among densities at samplings and no differences when averaged across the production season. Yield of fingerlings increased as stocking density increased with significant differences between the two highest and the two lowest stocking densities. Breakeven prices were lower at the higher stocking densities as a result of the higher yield of understocked fish and similar mean individual fish weights produced at these higher stocking densities. Overall, varying stocking densities of fingerlings in multiple-batch systems had little effect on production efficiency and water quality. Additional research on managing the population structure of carryover fish in commercial catfish ponds may be warranted. [source]


    Initial influence of fertilizer nitrogen types on water quality

    AQUACULTURE RESEARCH, Issue 7 2010
    Charles C Mischke
    Abstract Using different sources of nitrogen as fertilizers in nursery ponds may affect water quality and plankton responses. We evaluated water quality variables and plankton population responses when using different nitrogen sources for catfish nursery pond fertilization. We compared calcium nitrate (12% N), sodium nitrite (20% N), ammonium chloride (26% N), ammonium nitrate (34% N) and urea (45% N) in 190-L microcosms at equimolar nitrogen application rates. Sodium nitrite-fertilized microcosms had higher nitrite and nitrate levels during the first week; no other differences in the water quality were detected among fertilizer types (P>0.05). No differences in green algae, diatoms or cyanobacteria were detected among treatments; desirable zooplankton for catfish culture was increased in urea-fertilized microcosms. Based on these results, any form of nitrogen used for pond fertilization should perform similarly without causing substantial water quality deterioration. Ammonium nitrate and urea contain a higher percentage of nitrogen, requiring less volume to achieve dosing levels. If both urea and ammonium nitrate are available, we recommend using the one with the least cost per unit of nitrogen. If both types of fertilizer have an equal cost per unit of nitrogen, we recommend using urea because of the potential advantage of increasing desirable zooplankton concentrations. [source]


    Perceived criticism, marital interaction and relapse in unipolar depression,findings from a Korean sample

    CLINICAL PSYCHOLOGY AND PSYCHOTHERAPY (AN INTERNATIONAL JOURNAL OF THEORY & PRACTICE), Issue 5 2006
    Jung-Hye Kwon
    Perceived criticism by partner (PC) has been demonstrated to be a powerful predictor of depressive relapse. The purpose of this prospective 11-month study was to replicate this finding in an outpatient series of married women in Korea, but also to further explore the nature of PC in terms of qualities of the marital relationship and dysfunctional attitudes. The subjects consisted of 27 married female outpatients who had all been treated for major depression, but were in recovery at time of first contact or shortly after. All were interviewed at time 1 and then again after 11 months at time 2 to ascertain major depressive episode using the Korean version of SADS as well as completing the BDI. At first contact, questionnaire and interview assessments were used for marital quality and dysfunctional attitudes denoting dependency. There was a significant relationship between the single-item PC and depressive relapse at follow-up as predicted. This relationship was not enhanced by using the expanded item scale. PC and/or PC-E were significantly correlated with marital quality variables, specifically lack of emotional support from partner, negative interaction and dependence on partner. The study shows that perceived criticism by spouse is a predictor of depressive relapse in Korean outpatients and that this appears to reflect actual negative characteristics of the marital relationship as well as the depressed person's high dependence on the relationship. These results support the importance of improving marital interactions in preventing relapse in depression.,Copyright © 2006 John Wiley & Sons, Ltd. [source]