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Linear Trend (linear + trend)
Kinds of Linear Trend Selected AbstractsPower of Tests for Unit Roots in the Presence of a Linear Trend,OXFORD BULLETIN OF ECONOMICS & STATISTICS, Issue 5 2008Bent Nielsen Abstract Dickey and Fuller [Econometrica (1981) Vol. 49, pp. 1057,1072] suggested unit-root tests for an autoregressive model with a linear trend conditional on an initial observation. TPower of tests for unit roots in the presence of a linear trendightly different model with a random initial value in which nuisance parameters can easily be eliminated by an invariant reduction of the model. We show that invariance arguments can also be used when comparing power within a conditional model. In the context of the conditional model, the Dickey,Fuller test is shown to be more stringent than a number of unit-root tests motivated by models with random initial value. The power of the Dickey,Fuller test can be improved by making assumptions to the initial value. The practitioner therefore has to trade-off robustness and power, as assumptions about initial values are hard to test, but can give more power. [source] Intercomparison of global cloud cover fields over oceans from the VOS observations and NCEP/NCAR reanalysisINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 13 2007Ernst Bedacht Abstract The paper inter-compares the total cloud cover over the World Ocean from marine visual observations assimilated in the International Comprehensive Ocean-Atmosphere Data Set (ICOADS) and National Centers of Environmental Prediction/National Center of Atmospheric Research (NCEP-NCAR) reanalysis. The Intercomparison covers the period from 1948 to 2002. NCEP-NCAR reanalysis shows about 10% of fractional cloud cover smaller than the visual observations do. The largest differences are observed in the mid and sub-polar latitudes. In the tropics, NCEP-NCAR data show slightly higher cloud cover then ICOADS. These systematic differences are quite persistent through the year with somewhat stronger differences in summer. Comparison of the characteristics of inter-annual variability shows little consistency between visually observed total cloud cover and total cloudiness diagnosed by the reanalysis. Linear trends are primarily positive in the ICOADS cloud data, while in the NCEP-NCAR reanalysis they show downward trends in the tropics and upward tendencies in the mid and high latitudes. Analysis of the effect of sampling in ICOADS shows that sampling inhomogeneity cannot fully explain the disagreements observed. At the same time, the major climate variability patterns such as North Atlantic Oscillation (NAO) and El-Nino,Southern Oscillation (ENSO) are well captured in both ICOADS and NCEP-NCAR cloud cover data sets. Copyright © 2007 Royal Meteorological Society [source] Changes in spring weather conditions and atmospheric circulation in Estonia (1955,95)INTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 3 2003Sirje Keevallik Abstract An analysis has been undertaken at Tiirikoja Meteorological Station to investigate changes in the main weather elements in late winter and spring during the period 1955,95. The relationship between these changes and the trends in the atmospheric circulation above Estonia have also been analysed. The latter was estimated from wind speed and direction data recorded at Tallinn Aerological Station at two isobaric levels (500 and 850 hPa). These data permitted the analysts to calculate zonal and meridional components of wind velocity at both levels. Linear trends were fitted to time series of monthly averages of all parameters under consideration. The results indicate that significant changes in meteorological parameters took place in March. These changes are statistically related to the changes in the average airflow in the free atmosphere above Estonia. In March the wind speed at the 500 and 850 hPa isobaric levels increased and the average airflow turned from WNW or NW to SW or WSW. Such changes in the atmospheric circulation can only partly be attributed to the intensification of the North Atlantic oscillation. Copyright © 2003 Royal Meteorological Society [source] Body mass index and risk of stroke among Chinese men and womenANNALS OF NEUROLOGY, Issue 1 2010Lydia A. Bazzano MD Objective The relationship between body mass index (BMI) and stroke incidence and mortality remains controversial, particularly in Asian populations. Methods We conducted a prospective cohort study in a nationally representative sample of 169,871 Chinese men and women age 40 years or older. Data on body weight was obtained at baseline examination in 1991 using a standard protocol. Follow-up evaluation was conducted in 1999 to 2000, with a response rate of 93.4%. Results After excluding those participants with missing body weight or height values, 154,736 adults were included in the analysis. During a mean follow-up of 8.3 years, 7,489 strokes occurred (3,924 fatal). After adjustment for age, gender, physical inactivity, urbanization, geographic variation, cigarette smoking, diabetes, and education, compared with participants of normal weight (BMI 18.5,24.9), relative hazard (95% confidence interval) of incident stroke was 0.86 (0.80,0.93) for participants who were underweight (BMI < 18.5), 1.43 (1.36,1.52) for those who were overweight (BMI 25,29.9), and 1.72 (1.55,1.91) for those who were obese (BMI , 30). The corresponding relative hazards were 0.76 (0.66,0.86), 1.60 (1.48,1.72), and 1.89 (1.66,2.16) for ischemic stroke and 1.00 (0.89,1.13), 1.18 (1.06,1.31), and 1.54 (1.27,1.87) for hemorrhagic stroke. For stroke mortality, the corresponding relative hazards were 0.94 (0.86,1.03), 1.15 (1.05,1.25), and 1.47 (1.26,1.72). Linear trends were significant for all outcomes (p < 0.0001). Interpretation These results suggest that elevated BMI increases the risk of both ischemic and hemorrhagic stroke incidence, and stroke mortality in Chinese adults. ANN NEUROL 2010;67:11,20 [source] Timing of first alcohol use and alcohol dependence: evidence of common genetic influencesADDICTION, Issue 9 2009Carolyn E. Sartor ABSTRACT Aims To estimate the magnitude of genetic and environmental influences on timing of first alcohol use and alcohol dependence (AD) and to quantify the overlap in these influences across the two alcohol-related outcomes. Participants The sample consisted of 5382 twins (2691 complete pairs), aged 24,36 years, from the Australian Twin Registry. Measurements History of alcohol use and DSM-IV alcohol dependence were assessed by structured telephone interview. Findings In both sexes, the relationship between age at first alcohol use and risk for AD followed a linear trend, such that the highest rates of AD were observed in individuals who began drinking at an earlier than average age (14 years or younger). Heritability estimates for timing of first alcohol use and AD were 36% and 53%, respectively. Shared environmental factors accounted for 15% of variance in initiation. There was no evidence of shared environmental influences on AD. The genetic correlation between timing of first alcohol use and AD was 0.59. Conclusions Findings highlight the substantial role of genetics in the development of AD and the early manifestation of that genetic risk in the timing of alcohol use initiation which, unlike AD, is also influenced to a modest degree by shared environmental factors. The considerable overlap in heritable influences,and the virtual absence of overlap in individual-specific environmental influences,on initiation of alcohol use and AD indicates that the association between age at first drink and AD is attributable in large part to common genetic sources of variance. [source] Prevalence of alcohol use disorders and associated factors: a population-based study using AUDIT in southern BrazilADDICTION, Issue 6 2003Raúl A. Mendoza-Sassi ABSTRACT Aims To assess the prevalence of potential alcohol use disorders and associated factors using the Alcohol Use Disorders Identification Test (AUDIT). Design Cross-sectional study. Setting A town in southern Brazil. Participants A representative sample of 1260 people aged 15 and over. Measurements Demographic, socioeconomic, smoking habit and mental health data were collected. Logistic regression was used in the multivariate analysis, and odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. Findings Overall prevalence of alcohol use disorder was 7.9%, with 14.5% prevalence among men and 2.4% among women. The risk of alcohol misuse increased across social class (P linear trend = 0.03) and compared with the highest classes (A and B), groups C through E had ORs of 1.48, 1.51 and 2.36, respectively. Males had an OR of 6.89 (CI 3.61,13.16) compared with women. A linear trend was found (P = 0.001) between smoking categories, and smokers (OR 3.27; CI 1.91,5.58) and ex-smokers (OR 1.30; CI 0.56,2.98) were at higher risk than non-smokers. Those with minor psychiatric disorders had a 2.48 OR (CI 1.35,4.56) of presenting a positive test. Conclusions The AUDIT detected a high prevalence of potential alcohol use disorders in the population sampled. Those identified are potential targets for preventive measures implemented through health policies. [source] EFFECTS OF TEMPERATURE ON CERTAIN POPULATION PARAMETERS OF LIRIOMYZA SATIVAE BLAN-CHARD (DIPTERA: AGROMYZIDAE)INSECT SCIENCE, Issue 2 2000ZHANG Run-jie Abstract, Effects of temperature on population parameters and the intrinsic rate of natural increase of the leafminer, Liriomyza sativae Blanchard, were studied at constant temperatures, 15, 20, 25, 30 and 3593 80% RH and a photoperiod of 12:12 (L:D) in the laboratory with Phaseolus vulgaris as the host plant. Developmental time of the immature stage decreased from 38 d at 15C to lld at 3593 Regression equations relating temperature (t) to development rates (y) for egg, larval and pupal stages, were y = 1.7862t - 13.841, y = 1.162t - 4.946 and y= 0.634t - 5.146, respectively. Longevity of female adult decreased from 20 d at 15°C to 9 d with temperature up to 35C The most favorable temperature range for reproduction was 20°C - 30oC in which the fecundity ranged from 158 to 282 eggs per female. The lowest total mortality was 9% at 25oC and the highest was 49% at 35 93 High intrinsic rate of natural increase (rm) was 0.27 and high net reproductive rate (R0) was 116.8 at temperature range between 25 t and 30 t indicating that this range was optimal for population growth and that population density might increase 117 times per generation under this temperature condition. Mean generation time (T) and time for population to double (t) decreased as temperature increased, showing a negative linear trend with temperature. The relationship between finite rate of increase (A) and temperature, however, was a positive linear regression. [source] Carotenoids/vitamin C and smoking-related bladder cancerINTERNATIONAL JOURNAL OF CANCER, Issue 3 2004J. Esteban Castelao Abstract Previous epidemiological studies of fruit and vegetable intake and bladder cancer risk have yielded inconsistent results, especially with respect to the role of cigarette smoking as a possible modifier of the diet-bladder cancer association. A population-based case-control study was conducted in nonAsians of Los Angeles, California, which included 1,592 bladder cancer patients and an equal number of neighborhood controls matched to the index cases by sex, date of birth (within 5 years) and race between January 1, 1987 and April 30, 1996. Information on smoking, medical and medication history, and intake frequencies of food groups rich in preformed nitrosamines, vitamins A and C and various carotenoids, were collected through in-person, structured interviews. Beginning in January 1992, all case patients and their matched control subjects were asked for a blood sample donation at the end of the in-person interviews for measurements of 3- and 4-aminobiphenyl (ABP) hemoglobin adducts, and glutathione S -transferases M1/T1/P1 (GSTM1/T1/P1) and N -acetyltransferase-1 (NAT1) genotypes. Seven hundred seventy-one (74%) case patients and 775 (79%) control subjects consented to the blood donation requests. In addition, all case patients and matched control subjects were asked to donate an overnight urine specimen following caffeine consumption for measurements of cytochrome P4501A2 (CYP1A2) and N -acetyltransferase-2 (NAT2) phenotypes. Urine specimens were collected from 724 (69%) case patients and 689 (70%) control subjects. After adjustment for nondietary risk factors including cigarette smoking, there were strong inverse associations between bladder cancer risk and intake of dark-green vegetables [p value for linear trend (p) = 0.01], yellow-orange vegetables (p = 0.01), citrus fruits/juices (p = 0.002) and tomato products (p = 0.03). In terms of nutrients, bladder cancer risk was inversely associated with intake of both total carotenoids (p = 0.004) and vitamin C (p = 0.02). There was a close correlation (r = 0.58, p = 0.0001) between intakes of total carotenoids and vitamin C in study subjects. When both nutrients were included in a multivariate logistic regression model, only total carotenoids exhibited a residual effect that was of borderline statistical significance (p = 0.07 and p = 0.40 for total carotenoids and vitamin C, respectively). Cigarette smoking was a strong modifier of the observed dietary effects; these protective effects were confined largely to ever smokers and were stronger in current than ex-smokers. Smokers showed a statistically significant or borderline statistically significant decrease in 3- and 4-aminobiphenyl (ABP)-hemoglobin adduct level with increasing intake of carotenoids (p = 0.04 and 0.05, respectively). The protective effect of carotenoids on bladder cancer seemed to be influenced by NAT1 genotype, NAT2 phenotype and CYP1A2 phenotype; the association was mainly confined to subjects possessing the putative NAT1 -rapid, NAT2-rapid and CYP1A2-rapid genotype/phenotype. The carotenoid-bladder cancer association was not affected by the GSTM1, GSTT1 and GSTP1 genotypes. © 2004 Wiley-Liss, Inc. [source] Smoking May Impair the Bone Protective Effects of Nutritional Calcium: A Population-Based Approach,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 6 2003Joonas Sirola PhD Abstract Postmenopausal women were randomly selected to investigate the effects of smoking on prevention of bone loss with nutritional calcium. DXA was performed twice, and smoking and calcium intake habits were inquired through the mail in 954 women. Smoking dampened the bone protective effects of nutritional calcium. This may reflect the pathophysiology underlying smoking-induced bone loss postmenopause. This study evaluated the effect of smoking on the bone protective properties of nutritional calcium. Of the random sample of 954 peri- and postmenopausal women selected from the Osteoporosis Risk Factor and Prevention (OSTPRE) study cohort (n = 13,100) in Kuopio, Finland, 182 had smoked at some time (ever smokers) and 772 had never smoked. Women were divided in tertiles according to self-reported dairy nutritional calcium intake (mg/day): <648 (1st), 648-927 (2nd), >927 (3rd). Bone mineral density at lumbar spine (LS) and femoral neck (FN) was measured with DXA at baseline in 1989-1991 and at the 5-year follow-up in 1994-1997. In a linear regression model, nutritional calcium intake did not predict annual bone loss in smokers. These results were similar in the subanalysis on 71 current smokers (at both baseline and 5-year measurements) and on 85 past smokers. In never smokers, a statistically significant linear trend was observed between calcium intake and annual bone loss at LS, but at FN only after adjustment for age, weight, hormone replacement therapy (HRT), and other covariates. In analysis of covariance (ANCOVA), no differences in bone loss rate were observed between calcium intake tertiles among smokers. In nonsmokers, the annual bone loss rate was lower in the second (,0.41%) and the third (,0.35%) tertile compared with the first tertile (,0.61%) at LS (p < 0.05) and lower in the third tertile (,0.55%) than in first tertile (,0.72%) at FN after adjustment for age, weight, HRT, and other covariates (p < 0.05). When smokers were added to the nonsmoker group, the differences in bone loss rate between calcium intake tertiles disappeared. In addition, in ANCOVA, the term of interaction between smoking and calcium intake was statistically significant at LS only. In conclusion, smoking seems to impair the bone protective effects of nutritional calcium in postmenopausal women, more clearly in LS than FN. [source] Health interventions and satisfaction with services: a comparative study of urinary incontinence sufferers living in two health authorities in EnglandJOURNAL OF CLINICAL NURSING, Issue 5 2000Brenda Roe PhD, FRSH ,,This comparative study found that significantly more people with severe incontinence had contacted a health professional than had those with slight to moderate incontinence (P=0.00008). There was a significant linear trend towards people with severe incontinence seeing a health professional (P=0.00007). ,,The majority of people who were incontinent had not been asked to complete a bladder chart, which is an essential requirement for assessment and diagnosis of the type of incontinence and the subsequent health interventions that are offered. ,,Significantly more people in the health authority with an established continence advisory service had completed a bladder chart, had received physiotherapy and currently undertook pelvic floor muscle exercises than did those in the health authority without a continence service. ,,The majority of sufferers did not use any aids or appliances. Of those who did use incontinence aids, a majority bought their own. There was a significant linear trend for increased pad usage with increasing severity of incontinence (P=0.0003). ,,Significantly more people in the health authority with the continence service were satisfied with their healthcare and services, while more of those in the health authority without a service were unsatisfied (P=0.005). Significantly more people in the health authority without a service felt that healthcare and services could be improved (P=0.00001). ,,Significantly more people with severe incontinence were dissatisfied with services than were those with slight to moderate incontinence (P=0.01). [source] Serum concentrations of vitamin D and parathyroid hormone and prevalent metabolic syndrome among adults in the United StatesJOURNAL OF DIABETES, Issue 4 2009Earl S. FORD Abstract Background:, Some reports suggest that concentrations of vitamin D are inversely, whereas concentrations of parathyroid hormone (PTH) are directly, associated with prevalent metabolic syndrome. Because of lingering uncertainty about these associations, we examined the cross-sectional associations between serum concentrations of 25-hydroxyvitamin D3 and PTH with metabolic syndrome in a representative sample of adults in the US. Methods:, We used data from 1705 participants in the 2005,2006 National Health and Nutrition Examination Survey. Vitamin D was measured by radioimmunoassay, whereas PTH was measured using an electrochemiluminescent process. Results:, The mean concentration of vitamin D for participants with and without metabolic syndrome was 20.3 and 22.9 ng/mL, respectively (P = 0.001). The mean concentration of PTH for participants with and without metabolic syndrome was 44.5 and 41.0 pg/mL, respectively (P = 0.002). The age-adjusted mean concentrations of vitamin D (P for linear trend <0.001) decreased linearly, whereas PTH (P for linear trend = 0.002) increased linearly, as the number of components of metabolic syndrome increased. After adjusting for age, gender, physical activity, urinary albumin creatinine ratio, and concentrations of C-reactive protein and calcium, concentrations in the highest quintile of vitamin D [prevalence ratio (PR) = 0.59; 95% confidence interval (CI) 0.44,0.79], but not PTH (PR = 1.18; 95% CI 0.97,1.43), was significantly associated with prevalent metabolic syndrome. Conclusion:, Concentrations of vitamin D, but not PTH, were significantly associated with prevalent metabolic syndrome among US adults. [source] Mortality forecasting using neural networks and an application to cause-specific data for insurance purposesJOURNAL OF FORECASTING, Issue 6 2009Paras Shah Abstract Mortality forecasting is important for life insurance policies, as well as in other areas. Current techniques for forecasting mortality in the USA involve the use of the Lee,Carter model, which is primarily used without regard to cause. A method for forecasting morality is proposed which involves the use of neural networks. A comparative analysis is done between the Lee,Carter model, linear trend and the proposed method. The results confirm that the use of neural networks performs better than the Lee,Carter and linear trend model within 5% error. Furthermore, mortality rates and life expectancy were formulated for individuals with a specific cause based on prevalence data. The rates are broken down further into respective stages (cancer) based on the individual's diagnosis. Therefore, this approach allows life expectancy to be calculated based on an individual's state of health. Copyright © 2008 John Wiley & Sons, Ltd. [source] Metabolic syndrome, its preeminent clusters, incident coronary heart disease and all-cause mortality , results of prospective analysis for the Atherosclerosis Risk in Communities studyJOURNAL OF INTERNAL MEDICINE, Issue 1 2007Y. Hong Abstract. Objective., To investigate the prospective association between Metabolic Syndrome (MetS) and coronary heart disease (CHD) and all-cause mortality. Subjects and Design., A bi-racial cohort of 14 699 middle-aged Americans from the Atherosclerosis Risk in Communities study were followed for the development of new CHD and death over a period of 9 years. MetS, using the original ATP-III criteria, was defined as having at least three of the following components: elevated blood pressure (BP), elevated plasma glucose, elevated blood triglyceride (TG), increased waist circumference, and low HDL cholesterol (HDL-c). Incident CHD cases included hospitalized myocardial infarction (MI), fatal CHD, revascularization procedures, and silent MI as detected by EKG. Results., The prevalence of the MetS at baseline was 29%, 30%, 40% and 26% among CHD-free white women, white men, black women, and black men, respectively. There were 1018 incident CHD cases and 1039 deaths. The relative risk (RR) and 95% confidence interval (CI) of incident CHD associated with MetS was 2.46 (1.99, 3.03) for women and 1.86 (1.59, 2.18) for men. Clear dose,response relationship between the number of MetS components and incidence of CHD was found (P for linear trend <0.001). The following three clusters of MetS components posed the highest risk for CHD: (i) the elevated BP and glucose and low HDL-c group [RR = 5.68 (3.44, 9.37)]; (ii) the elevated BP and glucose and TG group [RR = 5.08 (2.96, 8.70)]; and (iii) the elevated BP and TG and low HDL-c group [RR = 3.98 (2.75, 5.77)]. When all five components co-existed, the risk was the highest [RR = 6.24 (4.65, 8.36)]. Similar results with attenuated RR were found for all-cause mortality. Conclusions., Individuals, especially women, with the MetS have significantly higher risk of developing CHD. The riskiest combination is high-BP and glucose clustered with low HDL-c or high TG. These data highlight the importance of targeting MetS in the prevention of CHD and premature death. [source] The association of psychosocial factors and smoking with periodontal health in a community populationJOURNAL OF PERIODONTAL RESEARCH, Issue 1 2010L.-J. Chiou Chiou L-J, Yang Y-H, Hung H-C, Tsai C-C, Shieh T-Y, Wu Y-M, Wang W-C, Hsu T-C. The association of psychosocial factors and smoking with periodontal health in a community population. J Periodont Res 2009; doi: 10.1111/j.1600-0765.2008.01194.x. © 2009 John Wiley & Sons A/S Background and Objective:, The association between psychosocial factors and periodontal disease has been widely reported and might be modified by smoking status. This study investigated the association of periodontal status with psychosocial factors and smoking in a community population. Material and Methods:, A structured questionnaire was administered to a total of 1764 civilian noninstitutional (general population excluding from nursing homes, sanitariums and hospitals) Taiwanese individuals to assess the presence and severity of psychosocial factors [using the 12-item Chinese health questionnaire (CHQ-12)], smoking habits and other related factors. Periodontal status was established using the community periodontal index and by measuring clinical loss of attachment. Results:, Psychological factors and smoking were significantly associated with loss of attachment (odds ratio = 1.69, 95% confidence interval = 1.01,2.77, comparing the CHQ-12 score of , 6 with the CHQ-12 score of 0,2 and p = 0.032 for linear trend; odds ratio = 2.21, 95% confidence interval = 1.45,3.37, comparing smokers with nonsmokers) but not with community periodontal index. The association was found to be stronger among smokers than among nonsmokers. Smokers with a CHQ-12 score of , 6 had a higher odds ratio of loss of attachment (odds ratio = 2.49, 95% confidence interval = 0.91,6.49) than nonsmokers (odds ratio = 1.43, 95% confidence interval = 0.76,2.58). For periodontal health measured using the community periodontal index, married and divorced/widowed subjects tended to have poorer periodontal health (odds ratio = 3.38, 95% confidence interval = 1.26,10.81 and odds ratio = 3.83, 95% confidence interval = 1.21,13.83, respectively) than single subjects among nonsmokers but not among smokers. Conclusion:, Poor mental health had a stronger association with periodontal disease among smokers than among nonsmokers, especially in accumulative attachment loss. Our findings suggest that mental health and smoking might have a synergistic effect on the risk of developing periodontal disease. [source] The effect of Emdogain® on the growth and differentiation of rat bone marrow cellsJOURNAL OF PERIODONTAL RESEARCH, Issue 5 2006J. Van Den Dolder Background and Objective:, The major extracellular matrix (ECM) proteins in developing enamel can induce and maintain the formation and mineralization of other skeletal hard tissue, such as bone. Therefore, dental matrix proteins are ideal therapeutic agents when direct formation of functional bone is required for a successful clinical outcome. Emdogain® (EMD) consists of enamel matrix proteins which are known to stimulate bone formation. However, only a few studies in the literature have reported the effect of EMD on osteoblast-like cells in vitro. Material and Methods:, In this study, rat bone marrow cells, obtained from the femora of Wistar rats, were precultured for 7 d in osteogenic medium. Then, the cells were harvested and seeded in 24-well plates at a concentration of 20,000 cells/well. The wells were either precoated with 100 µg/ml EMD, or left uncoated. The seeded cells were cultured in osteogenic medium for 32 d and analysed for cell attachment (by using the Live and Dead assay), cell growth (by determining DNA content) and cell differentiation (by measuring alkaline phosphatase activity and calcium content, and by using scanning electron microscopy and the reverse transcription,polymerase chain reaction). Results:, The results showed that at the 4-h time point of the experiment, more cells were attached to EMD-negative wells, but this effect was no longer apparent at 24 h. DNA analysis revealed that both groups showed a similar linear trend of cell growth. No differences in alkaline phosphatase activity or calcium content were observed, and no differences in gene expression (osteocalcin, alkaline phosphatase and collagen type I) were found between the groups. Conclusion:, Based on our results, we conclude that EMD had no significant effect on the cell growth and differentiation of rat bone marrow cells. [source] Alcohol Availability and Intimate Partner Violence Among US CouplesALCOHOLISM, Issue 1 2009Christy M. McKinney Objectives:, We examined the relation between alcohol outlet density (the number of alcohol outlets per capita by zip code) and male-to-female partner violence (MFPV) or female-to-male partner violence (FMPV). We also investigated whether binge drinking or the presence of alcohol-related problems altered the relationship between alcohol outlet density and MFPV or FMPV. Methods:, We linked individual and couple sociodemographic and behavioral data from a 1995 national population-based sample of 1,597 couples to alcohol outlet data and 1990 US Census sociodemographic information. We used logistic regression for survey data to estimate unadjusted and adjusted odds ratios between alcohol outlet density and MFPV or FMPV along with 95% confidence intervals (CIs) and p -values. We used a design-based Wald test to derive a p -value for multiplicative interaction to assess the role of binge drinking and alcohol-related problems. Results:, In adjusted analysis, an increase of one alcohol outlet per 10,000 persons was associated with a 1.03-fold increased risk of MFPV (p -value for linear trend = 0.01) and a 1.011-fold increased risk of FMPV (p -value for linear trend = 0.48). An increase of 10 alcohol outlets per 10,000 persons was associated with 34% and 12% increased risk of MFPV and FMPV respectively, though the CI for the association with FMPV was compatible with no increased risk. The relationship between alcohol outlet density and MFPV was stronger among couples reporting alcohol-related problems than those reporting no problems (p -value for multiplicative interaction = 0.01). Conclusions:, We found that as alcohol outlet density increases so does the risk of MFPV and that this relationship may differ for couples who do and do not report alcohol-related problems. Given that MFPV accounts for the majority of injuries related to intimate partner violence, policy makers may wish to carefully consider the potential benefit of limiting alcohol outlet density to reduce MFPV and its adverse consequences. [source] Prospective Study of Alcohol Consumption in the United States: Quantity, Frequency, and Cause-Specific MortalityALCOHOLISM, Issue 3 2008Rosalind A. Breslow Background:, Alcohol average volume (quantity multiplied by frequency) has been associated with mortality in drinkers. However, average volume may mask associations due to quantity or frequency alone. Methods:, We prospectively assessed relationships between alcohol quantity and frequency, and mortality from all-causes, cardiovascular disease, cancer, and other-causes in a cohort created by linking the 1988 National Health Interview Survey (response rate 87%) to the National Death Index through 2002. Participants were 20,765 current drinkers age , 18 years. At 14-year follow-up 2,547 had died. Results:, For quantity, among men who consumed ,5 drinks (compared to 1 drink) on drinking days, adjusted relative risks (RR) of mortality were: for cardiovascular disease, 1.30 [95% confidence interval (CI) 0.96,1.75; p for linear trend (p -trend) = 0.0295], for cancer, 1.53 (95% CI 1.11,2.09; p -trend = 0.0026), and for other-causes, 1.42 (95% CI 1.08,1.87; p -trend = 0.0029); among women for other-causes, 2.88 (95% CI 1.61,5.12; p -trend = 0.0010). For frequency, among men in the highest frequency quartile (compared to the lowest), RR were: for cardiovascular disease, 0.79 (95% CI 0.63,0.99; p -trend = 0.0330), for cancer, 1.23 (95% CI 0.95,1.59; p -trend = 0.0461), and for other-causes, 1.30 (95% CI 1.01,1.67; p -trend = 0.0070); among women, for cancer, 1.65 (95% CI 1.12,2.45, p -trend = 0.0031). Average volume obscured effects of quantity alone and frequency alone, particularly for cardiovascular disease in men where quantity and frequency trended in opposite directions. Conclusions:, Alcohol quantity and frequency were independently associated with cause-specific mortality. Accumulating evidence of their differential effects may, in the future, be useful for clinical and public health recommendations. [source] Usual sleep duration and cognitive function in older adults in SpainJOURNAL OF SLEEP RESEARCH, Issue 4 2009RAQUEL FAUBEL Summary The few studies that have examined the association between usual sleep duration and cognitive function have shown conflicting results. This cross-sectional study examined the association between sleep duration and cognitive function among 3212 people, representative of the non-institutionalized population aged 60 years and over in Spain. Sleep duration was self-reported, and cognitive function was measured with the Mini-Examen Cognoscitivo (MEC), a version of the Mini-Mental State Examination that has been validated in Spain. Linear regression, with adjustment for the main confounders, was used to obtain mean differences in the MEC between the categories of sleep duration (,5, 6, 7, 8, 9, 10, ,11 h day,1). The MEC score decreased progressively (became worse) across sleep categories from 7 to ,11 h (P for linear trend <0.001). People who slept for ,11 h had a significantly lower MEC score than those who slept for 7 h (mean difference ,1.48; 95% confidence interval ,2.12 to ,0.85). This difference in the MEC was similar to that observed for a 10-year increase in age. The results did not vary significantly by sex (P for interaction >0.05). No association was observed between short sleep duration (<7 h) and cognitive function. We conclude that long sleep duration is associated with poorer cognitive function in older adults from the general population. [source] The relative kinetics of clotting and lysis provide a biochemical rationale for the correlation between elevated fibrinogen and cardiovascular diseaseJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 6 2007P. Y. KIM Summary.,Background:,Elevated plasma fibrinogen is a well known risk factor for cardiovascular disease. The mechanistic rationale for this is not known.Objectives:,These studies were carried out to determine the fibrinogen concentration dependencies of clotting and lysis times and thereby determine whether these times rationalize the correlation between an increased risk of cardiovascular disease and elevated plasma fibrinogen.Methods:,The time courses of clot formation and lysis were measured by turbidity in systems comprising a) fibrinogen, thrombin and plasmin, or b) fibrinogen, thrombin, plasminogen and t-PA, or c) plasma, thrombin and t-PA. From the lysis times, kcat and Km values for plasmin action on fibrin were determined.Results:,The time to clot increased linearly from 2.9 to 5.6 minutes as the fibrinogen concentration increased from 1 to 9 ,M and did not increase further as the fibrinogen concentration was raised to 20 ,M. In contrast, the clot lysis time increased linearly over the input fibrinogen concentration range of 2 to 20 ,M. A similar linear trend was found in the two systems with t-PA and plasminogen. Apparent Km and kcat values for plasmin were 1.1 ± 0.6 ,M and 28 ± 2 min,1, respectively. Km values for plasmin in experiments initiated with t-PA and plasminogen were 1.6 ± 0.2 ,M in the purified system and 2.1 ± 0.9 ,M in plasma.Conclusion:,As the concentration of fibrinogen increases, especially above physiologic level, the balance between fibrinolysis and clotting shifts toward the latter, providing a rationale for the increased risk of cardiovascular disease associated with elevated fibrinogen. [source] Spurious Regression Under Broken-Trend StationarityJOURNAL OF TIME SERIES ANALYSIS, Issue 5 2006Antonio E. Noriega C22 Abstract., We study the phenomenon of spurious regression between two random variables, when the generating mechanism of individual series is assumed to follow a stationary process around a trend with (possibly) multiple breaks in the level and slope of trend. We develop the relevant asymptotic theory and show that the phenomenon of spurious regression occurs independent of the structure assumed for the errors. In contrast to previous findings, the presence of a spurious relationship will be less severe when breaks are present in the generating mechanism of individual series. This is true whether the regression model includes a linear trend or not. Simulations confirm our asymptotic results, and reveal that in finite samples, the phenomenon of spurious regression is sensitive to the presence of a linear trend in the regression model and to the relative location of breaks within the sample. [source] Nitrites in induced sputum as a simple and cheap non-invasive marker of airway inflammation for asthmatic schoolchildrenPEDIATRIC ALLERGY AND IMMUNOLOGY, Issue 5 2008Arturo Recabarren To determine if there are differences in the nitric oxide metabolites (nitrites) in sputum of patients with persistent asthma and healthy schoolchildren, we performed a case-control study in a tertiary care hospital in Arequipa, Perú. Nitrites in induced sputum samples were measured using the Griess assay in 30 persistent asthmatics (mean age of 10.1 yr) and 30 controls (mean age of 11.9 yr). The mean ± s.d. of nitrites among asthmatics was significantly higher than the controls (16.30 ± 8.6 vs. 10.25 ± 4.68 nmol/ml, respectively, p = 0.001). Moreover, the nitrite level in the sputum in children with severe persistent asthma was higher than in the level found in the moderate and mild asthmatics (32.83 ± 9.48 vs. 18.10 ± 1.96 vs. 11.84 ± 4.73 nmol/ml, respectively, p < 0.01 for linear trend). This study showed for the first time in children that asthmatics have significantly higher levels of nitrites in induced sputum than healthy controls and that the level of nitrite correlates with the severity of the asthma. Nitrite levels in sputum, a simple and cheap, non-invasive method, may be a good alternative to measure the severity of inflammation in asthmatic children. [source] Trends in genetic variance components during 30 years of hybrid maize breeding at the University of HohenheimPLANT BREEDING, Issue 5 2008S. Fischer Abstract The ratio of variance due to specific vs. general combining ability (GCA) (,2SCA:,2GCA) is of central importance for predicting hybrid performance from GCA effects. The objectives of our study were to (1) analyse the changes in estimates of ,2GCA, ,2SCA and their ratio during 30 years of hybrid maize breeding and (2) compare the observed trends in genetic variances with those expected under a simple genetic model. We analysed multilocation yield trials based on the North Carolina Design II conducted in the maize breeding programme of the University of Hohenheim from 1975 to 2004 for grain yield (GY) and dry matter content (DMC). GY showed a significant (P < 0.05) annual increase of 0.17 Mg/ha, but no linear trend was found for DMC. Since the beginning of hybrid breeding at the University of Hohenheim, the sum of estimates of ,2GCA of the flint and dent heterotic groups were higher than the estimates of their ,2SCA. This predominance did not change with ongoing inter-population improvement. Consequently, superior hybrids can be identified and selected mainly based on their prediction from GCA effects. [source] Occupational risk factors for non-Hodgkin's lymphoma: A population-based case,control study in Northern GermanyAMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 4 2008David B. Richardson Abstract Objectives To identify occupational factors associated with non-Hodgkin's lymphoma (NHL). Methods A population-based case,control study was conducted in which incident cases of high-malignancy NHL (NHLhigh), low-malignancy NHL (NHLlow), and chronic lymphocytic leukemia (CLL) were ascertained during the period 1986,1998 among men and women aged 15,75 years residing in six German counties; controls were drawn from population registries. Occupational histories were collected and agent-specific exposures were estimated via a job-exposure-matrix. Odds ratios were estimated by conditional logistic regression. Results A total of 858 cases were included in these analyses. Agricultural workers [odds ratio (OR),=,2.67, 95% confidence interval (CI): 0.99, 7.21) and farmers (OR,=,1.98, 95% CI: 0.98, 3.98] had elevated risk of NHLhigh. Risk of NHLlow was elevated among agricultural workers (OR,=,2.46, 95% CI: 1.17, 5.16), and among blacksmiths, toolmakers, and machine tool operators (OR,=,3.12, 95% CI: 1.31, 7.47). Workers in sales and construction had elevated risks of NHLhigh and NHLlow. Exposure to arsenic compounds, chlorophenols, diesel fuel, herbicides, nitrites/nitrates/nitrosamines, and organic dusts were associated with NHLhigh and NHLlow, while exhibiting little association with CLL. A positive monotonic trend in NHLlow risk across tertiles of cumulative diesel fuel exposure was observed [P -value for test of linear trend (P),=,0.03]. Conclusions These findings provide insights into several potential occupational risk factors for NHL and suggest some specific occupational agents for further investigation. Am. J. Ind. Med. 51:258,268, 2008. © 2008 Wiley-Liss, Inc. [source] Fiber orientation control of short-fiber reinforced thermoplastics by ram extrusionPOLYMER COMPOSITES, Issue 5 2003Yukio Sanomura In this study we examine the fiber orientation distribution, fiber length and Young's modulus of extruded short-fiber reinforced thermoplastics such as polypropylene. Axial orientation distributions are presented to illustrate the influence of extrusion ratio on the orientation state of the fibrous phase. Fibers are markedly aligned parallel to the extrusion direction with increasing extrusion ratio. The orientation state of extruded fiber-reinforced thermoplastics (FRTP) is almost uniform throughout the section. The control of fiber orientation can be easily achieved by means of ram extrusion. Experimental results are also presented for Young's modulus of extruded FRTP in the extrusion direction. Young's modulus follows a linear trend with increasing extrusion ratio because the degree of the molecular orientation and the fiber orientation increases. The model proposed by Cox, and Fukuda and Kawada describes the effect of fiber length and orientation on Young's modulus. The value of the orientation coefficient is calculated by assuming a rectangular orientation distribution and calculating the fiber distribution limit angle given by orientation parameters. By comparing the predicted Young's modulus with experimental results, the validity of the model is elucidated. The mean fiber length linearly decreases with increasing extrusion ratio because of fiber breakage due to plastic deformation. There is a small effect on Young's modulus due to fiber breakage by ram extrusion. [source] Semantic transparency and masked morphological priming: An ERP investigationPSYCHOPHYSIOLOGY, Issue 4 2007Joanna Morris Abstract The role of semantics in the segmentation of morphologically complex words was examined using event-related potentials (ERPs) recorded to target words primed by semantically transparent (hunter,hunt,) opaque (corner,corn), and orthographically related (scandal,scan) masked primes. Behavioral data showed that only transparent items gave rise to priming. The ERP data showed both N250 and the N400 effects with transparent items generating greater priming than orthographic or opaque. Furthermore, priming effects across conditions revealed the existence of a significant linear trend, with transparent items showing the greatest effects and orthographic items the smallest, suggesting that these priming effects vary as a function of morphological structure and semantic transparency. The results are discussed in terms of a model of morphological processing. [source] The Covariance Structure of Italian Male WagesTHE MANCHESTER SCHOOL, Issue 6 2000Lorenzo Cappellari Using an unbalanced panel of Italian male wages covering the 1974,88 interval, in this study we estimate the parameters of the wage covariance structure by minimum distance. Estimated variance components models allow for a linear trend in permanent wages, so that wage profile convergence can be assessed by considering the covariance between intercepts and slopes of such individual trends. Evidence of permanent wage convergence is found in the overall wage distribution, but not within white collar workers data; this contrasts with human capital interpretations of wage dynamics and suggests that other factors, such as the egalitarian wage-setting framework fully effective until the mid-1980s, could have played a major role in shaping the wage distribution. [source] Comparison of ACINUS, caspase-3, and TUNEL as apoptotic markers in determination of tumor growth rates of clinically localized prostate cancer using image analysisTHE PROSTATE, Issue 15 2009Swaroop S. Singh Abstract BACKGROUND The balance between apoptotic and proliferative processes determines the enlargement of a tumor. Accurate measurement of apoptotic and proliferative rates from diagnostic prostate biopsies would allow calculation of tumor growth rates in a population-based prostate cancer (CaP) study. Automated image analysis may be used if proliferation and apoptotic biomarkers provide clearly resolved immunostained images. METHODS Clinical CaP aggressiveness was assigned as low, intermediate or high using clinical criteria for 46 research subjects with newly diagnosed CaP. Diagnostic biopsy sections from the research subjects were dual-labeled for proliferation biomarker, Ki-67 and apoptotic biomarker, apoptotic chromatin condensation inducer in the nucleus (ACINUS). Apoptotic biomarkers, caspase-3 and terminal deoxyribonucleotidyltransferase mediated dUTP-biotin nick end labeling (TUNEL) were labeled separately. Images from immunostained sections were analyzed using automated image analysis and tumor growth rates computed. Association between clinical CaP aggressiveness and tumor growth rates was explored. RESULTS Sixteen subjects had high, 17 had intermediate, and 13 had low clinical CaP aggressiveness. Positive immunostaining was localized to the nucleus for Ki-67, ACINUS, and TUNEL. A statistically significant linear trend across clinical CaP aggressiveness categories was found when tumor growth rates were calculated using ACINUS (P,=,0.046). Logistic regression and ROC plots generated showed ACINUS (AUC,=,0.677, P,=,0.048) and caspase-3 (AUC,=,0.694, P,=,0.038) to be better predictors than TUNEL (AUC,=,0.669, P,=,0.110). CONCLUSIONS ACINUS met the criteria for automated image analysis and for calculation of apoptotic rate. Tumor growth rates determined using automated image analysis should be evaluated for clinical prediction of CaP aggressiveness, treatment response, recurrence, and mortality. Prostate 69: 1603,1610, 2009. © 2009 Wiley-Liss, Inc. [source] Incidence Rate and Outcome of Gram-Negative Bloodstream Infection in Solid Organ Transplant RecipientsAMERICAN JOURNAL OF TRANSPLANTATION, Issue 4 2009M. N. Al-Hasan Bacterial infections are common complications of solid organ transplantation (SOT). In this study, we defined the incidence, mortality and in vitro antimicrobial resistance rates of Gram-negative bloodstream infection (BSI) in SOT recipients. We identified 223 patients who developed Gram-negative BSI among a cohort of 3367 SOT recipients who were prospectively followed at the Mayo Clinic (Rochester, MN) from January 1, 1996 to December 31, 2007. The highest incidence rate (IR) of Gram-negative BSI was observed within the first month following SOT (210.3/1000 person-years [95% confidence interval (CI): 159.3,268.3]), with a sharp decline to 25.7 (95% CI: 20.1,32.1) and 8.2 (95% CI: 6.7,10.0) per 1000 person-years between 2 and 12 months and more than 12 months following SOT, respectively. Kidney recipients were more likely to develop Gram-negative BSI after 12 months following transplantation than were liver recipients (10.3 [95% CI: 7.9,13.1] vs. 5.2 [95% CI: 3.1,7.8] per 1000 person-years). The overall unadjusted 28-day all-cause mortality of Gram-negative BSI was 4.9% and was lower in kidney than in liver recipients (1.6% vs. 13.2%, p < 0.001). We observed a linear trend of increasing resistance among Escherichia coli isolates to fluoroquinolone antibiotics from 0% to 44% (p = 0.002) throughout the study period. This increase in antimicrobial resistance may influence the choice of empiric therapy. [source] Telomere length predicts poststroke mortality, dementia, and cognitive declineANNALS OF NEUROLOGY, Issue 2 2006Carmen Martin-Ruiz PhD Objective Long-term cognitive development is variable among stroke survivors, with a high proportion developing dementia. Early identification of those at risk is highly desirable to target interventions for secondary prevention. Telomere length in peripheral blood mononuclear cells was tested as prognostic risk marker. Methods A cohort of 195 nondemented stroke survivors was followed prospectively from 3 months after stroke for 2 years for cognitive assessment and diagnosis of dementia and for 5 years for survival. Telomere lengths in peripheral blood mononuclear cells were measured at 3 months after stroke by in-gel hybridization. Hazard ratios for survival in relation to telomere length and odds ratios for dementia were estimated using multivariate techniques, and changes in Mini-Mental State Examination scores between baseline and 2 years were related to telomere length using multivariate linear regression. Results Longer telomeres at baseline were associated with reduced risk for death (hazard ratio for linear trend per 1,000bp = 0.52; 95% confidence interval, 0.28,0.98; p = 0.04, adjusted for age) and dementia (odds ratio for linear trend per 1,000bp = 0.19; 95% confidence interval, 0.07,0.54; p = 0.002) and less reduction in Mini-Mental State Examination score (p = 0.04, adjusted for baseline score). Interpretation Telomere length is a prognostic marker for poststroke cognitive decline, dementia, and death. Ann Neurol 2006 [source] Early mobilization after total knee replacement reduces the incidence of deep venous thrombosisANZ JOURNAL OF SURGERY, Issue 7-8 2009Sivashankar Chandrasekaran Abstract Both chemical and mechanical methods of prophylaxis have reduced the incidence of thromboembolic complications following total knee replacement (TKR). Only a few studies have shown that mobilization on the first post-operative day further reduces the incidence of thromboembolic phenomena. We conducted a prospective study to verify not only if early mobilization but also whether the distance mobilized on the first post-operative day after TKR reduced the incidence of thromboembolic complications. The incidence of deep venous thrombosis and pulmonary embolism were compared in 50 consecutive patients who underwent TKR from July 2006 following a change in the mobilization protocol with 50 consecutive patients who underwent TKR before the protocol was instigated. The mobilization protocol changed from strict bed rest the first post-operative day to mobilization on the first post-operative day. Mobilization was defined as sitting out of bed or walking for at least 15,30 min twice a day. The distance mobilized was accurately recorded by the physiotherapists. All patients underwent duplex scans of both lower limbs on the fourth post-operative day. There was a significant reduction in the incidence of thromboembolic complications in the mobilization group (seven in total) compared with the control group (16 in total) (P= 0.03). Furthermore, in the mobilization group the odds of developing a thromboemobloic complication was significantly reduced the greater the distance the patient mobilized (Chi-squared linear trend = 8.009, P= 0.0047). Early mobilization in the first 24 h after TKR is a cheap and effective way to reduce the incidence of post-operative deep venous thrombosis. [source] | |||||||||||||||||||||||||||||||||||||