Dietz, Rune; Rigét, Frank F; Sonne, Christian; Born, Erik W; Bechshøft, Thea; McKinney, Melissa A; Drimmie, Robert J; Muir, Derek C G; Letcher, Robert J
2013-09-01
Brominated flame retardants were determined in adipose tissues from 294 polar bears (Ursus maritimus) sampled in East Greenland in 23 of the 28years between 1983 and 2010. Significant linear increases were found for sum polybrominated diphenyl ether (ΣPBDE), BDE100, BDE153, and hexabromocyclododecane (HBCD). Average increases of 5.0% per year (range: 2.9-7.6%/year) were found for the subadult polar bears. BDE47 and BDE99 concentrations did not show a significant linear trend over time, but rather a significant non-linear trend peaking between 2000 and 2004. The average ΣPBDE concentrations increased 2.3 fold from 25.0ng/g lw (95% C.I.: 15.3-34.7ng/g lw) in 1983-1986 to 58.5ng/g lw (95% C.I.: 43.6-73.4ng/g lw) in 2006-2010. Similar but fewer statistically significant trends were found for adult females and adult males likely due to smaller sample size and years. Analyses of δ(15)N and δ(13)C stable isotopes in hair revealed no clear linear temporal trends in trophic level or carbon source, respectively, and non-linear trends differed among sex and age groups. These increasing concentrations of organobromine contaminants contribute to complex organohalogen mixture, already causing health effects to the East Greenland polar bears. Copyright © 2012 Elsevier Ltd. All rights reserved.
Ryberg, Karen R.; Vecchia, Aldo V.
2006-01-01
This report presents the results of a study conducted by the U.S. Geological Survey, in cooperation with the North Dakota State Water Commission, the Devils Lake Basin Joint Water Resource Board, and the Red River Joint Water Resource District, to analyze historical water-quality trends in three dissolved major ions, three nutrients, and one dissolved trace element for eight stations in the Devils Lake Basin in North Dakota and to develop an efficient sampling design to monitor the future trends. A multiple-regression model was used to detect and remove streamflow-related variability in constituent concentrations. To separate the natural variability in concentration as a result of variability in streamflow from the variability in concentration as a result of other factors, the base-10 logarithm of daily streamflow was divided into four components-a 5-year streamflow anomaly, an annual streamflow anomaly, a seasonal streamflow anomaly, and a daily streamflow anomaly. The constituent concentrations then were adjusted for streamflow-related variability by removing the 5-year, annual, seasonal, and daily variability. Constituents used for the water-quality trend analysis were evaluated for a step trend to examine the effect of Channel A on water quality in the basin and a linear trend to detect gradual changes with time from January 1980 through September 2003. The fitted upward linear trends for dissolved calcium concentrations during 1980-2003 for two stations were significant. The fitted step trends for dissolved sulfate concentrations for three stations were positive and similar in magnitude. Of the three upward trends, one was significant. The fitted step trends for dissolved chloride concentrations were positive but insignificant. The fitted linear trends for the upstream stations were small and insignificant, but three of the downward trends that occurred during 1980-2003 for the remaining stations were significant. The fitted upward linear trends for dissolved nitrite plus nitrate as nitrogen concentrations during 1987-2003 for two stations were significant. However, concentrations during recent years appear to be lower than those for the 1970s and early 1980s but higher than those for the late 1980s and early 1990s. The fitted downward linear trend for dissolved ammonia concentrations for one station was significant. The fitted linear trends for total phosphorus concentrations for two stations were significant. Upward trends for total phosphorus concentrations occurred from the late 1980s to 2003 for most stations, but a small and insignificant downward trend occurred for one station. Continued monitoring will be needed to determine if the recent trend toward higher dissolved nitrite plus nitrate as nitrogen and total phosphorus concentrations continues in the future. For continued monitoring of water-quality trends in the upper Devils Lake Basin, an efficient sampling design consists of five major-ion, nutrient, and trace-element samples per year at three existing stream stations and at three existing lake stations. This sampling design requires the collection of 15 stream samples and 15 lake samples per year rather than 16 stream samples and 20 lake samples per year as in the 1992-2003 program. Thus, the design would result in a program that is less costly and more efficient than the 1992-2003 program but that still would provide the data needed to monitor water-quality trends in the Devils Lake Basin.
Chen, Xiaoqiu; Tian, Youhua; Xu, Lin
2015-10-01
Using leaf unfolding and leaf coloration data of a widely distributed herbaceous species, Taraxacum mongolicum, we detected linear trend and temperature response of the growing season at 52 stations from 1990 to 2009. Across the research region, the mean growing season beginning date marginal significantly advanced at a rate of -2.1 days per decade, while the mean growing season end date was significantly delayed at a rate of 3.1 days per decade. The mean growing season length was significantly prolonged at a rate of 5.1 days per decade. Over the 52 stations, linear trends of the beginning date correlate negatively with linear trends of spring temperature, whereas linear trends of the end date and length correlate positively with linear trends of autumn temperature and annual mean temperature. Moreover, the growing season linear trends are also closely related to the growing season responses to temperature and geographic coordinates plus elevation. Regarding growing season responses to temperature, a 1 °C increase in regional mean spring temperature results in an advancement of 2.1 days in regional mean growing season beginning date, and a 1 °C increase in regional mean autumn temperature causes a delay of 2.3 days in regional mean growing season end date. A 1 °C increase in regional annual mean temperature induces an extension of 8.7 days in regional mean growing season length. Over the 52 stations, response of the beginning date to spring temperature depends mainly on local annual mean temperature and geographic coordinates plus elevation. Namely, a 1 °C increase in spring temperature induces a larger advancement of the beginning date at warmer locations with lower latitudes and further west longitudes than at colder locations with higher latitudes and further east longitudes, while a 1 °C increase in spring temperature causes a larger advancement of the beginning date at higher than at lower elevations.
NASA Astrophysics Data System (ADS)
Chen, Xiaoqiu; Tian, Youhua; Xu, Lin
2015-10-01
Using leaf unfolding and leaf coloration data of a widely distributed herbaceous species, Taraxacum mongolicum, we detected linear trend and temperature response of the growing season at 52 stations from 1990 to 2009. Across the research region, the mean growing season beginning date marginal significantly advanced at a rate of -2.1 days per decade, while the mean growing season end date was significantly delayed at a rate of 3.1 days per decade. The mean growing season length was significantly prolonged at a rate of 5.1 days per decade. Over the 52 stations, linear trends of the beginning date correlate negatively with linear trends of spring temperature, whereas linear trends of the end date and length correlate positively with linear trends of autumn temperature and annual mean temperature. Moreover, the growing season linear trends are also closely related to the growing season responses to temperature and geographic coordinates plus elevation. Regarding growing season responses to temperature, a 1 °C increase in regional mean spring temperature results in an advancement of 2.1 days in regional mean growing season beginning date, and a 1 °C increase in regional mean autumn temperature causes a delay of 2.3 days in regional mean growing season end date. A 1 °C increase in regional annual mean temperature induces an extension of 8.7 days in regional mean growing season length. Over the 52 stations, response of the beginning date to spring temperature depends mainly on local annual mean temperature and geographic coordinates plus elevation. Namely, a 1 °C increase in spring temperature induces a larger advancement of the beginning date at warmer locations with lower latitudes and further west longitudes than at colder locations with higher latitudes and further east longitudes, while a 1 °C increase in spring temperature causes a larger advancement of the beginning date at higher than at lower elevations.
Graber, C J; Hutchings, C; Dong, F; Lee, W; Chung, J K; Tran, T
2012-01-01
There is concern that widespread usage of ertapenem may promote cross-resistance to other carbapenems. To analyse the impact that adding ertapenem to our hospital formulary had on usage of other broad-spectrum agents and on susceptibilities of nosocomial Enterobacteriaceae and Pseudomonas isolates, we performed interrupted time-series analyses to determine the change in linear trend in antibiotic usage and change in mean proportion and linear trend of susceptibility pre- (March 2004-June 2005) and post- (July 2005-December 2008) ertapenem introduction. Usage of piperacillin-tazobactam (P=0·0013) and ampicillin-sulbactam (P=0·035) declined post-ertapenem introduction. For Enterobacteriaceae, the mean proportion susceptible to ciprofloxacin (P=0·016) and piperacillin-tazobactam (P=0·038) increased, while the linear trend in susceptibility significantly increased for cefepime (P=0·012) but declined for ceftriaxone (P=0·0032). For Pseudomonas, the mean proportion susceptible to cefepime (P=0·011) and piperacillin-tazobactam (P=0·028) increased, as did the linear trend in susceptibility to ciprofloxacin (P=0·028). Notably, no significant changes in carbapenem susceptibility were observed.
Medico-legal litigation in Obstetrics: a characterization analysis of a decade in Portugal.
Domingues, Ana Patrícia Rodrigues; Belo, Adriana; Moura, Paulo; Vieira, Duarte Nuno
2015-05-01
It was to analyse the most critical areas in Obstetrics and to suggest measures to reduce or avoid the situations most often involved in these disputes. Obstetrics cases submitted to the Medico-legal Council since the creation of the National Institute of Legal Medicine and Forensic Sciences in 2001 until 2011 were evaluated. A comprehensive characterization, determination of absolute/relative frequencies, hypothesis of a linear trend over the years and the association between each parameter was done. The analysis has shown no significantly linear trend. The most common reasons for disputes were perinatal asphyxia (50%), traumatic injuries of the newborn (24%), maternal sequelae (19%) and issues related to prenatal diagnosis and/or obstetric ultrasound (5.4%). Perinatal asphyxia showed no significantly linear trend (p=0.58) and was usually related to perinatal deaths or permanent neurologic sequelae in newborn children. Traumatic injuries of the newborn, mostly related to instrumented deliveries, shoulder dystocia or vaginal delivery in breech presentation, has shown a significantly increased linear trend (p<0.001), especially related to instrumented deliveries. The delay/absence of cesarean section was the clinical procedure questioned in a significantly higher number of cases of perinatal asphyxia (68.7%) and of traumatic lesions of the newborn due to instrumented deliveries (20.5%). It is important to improve and correct theoretical/practical daily clinical performance in these highlighted areas, in order to reduce or even avoid situations that could end up in medico-legal litigations.
Sichert-Hellert, W; Kersting, M; Manz, F
2001-04-01
Although fortified products have played an increasing role in food marketing since the 1980s in Germany, data as to the consumption of fortified food is sparse. To assess long-term data on changes in fortified food supply or consumption patterns, nutrient intake, and time trends in the DONALD Study (Dortmund Nutritional and Anthropometric Longitudinally Designed Study). Between 1985 and 2000 consumption of nutrient intake (total and from fortified foods) was evaluated and time trends in energy and nutrient intake were assessed on the basis of 3-day weighed dietary records (n = 4193) of 2-14 year-old males (n = 383) and females (n = 404) enrolled in the DONALD Study. Nutrient intake was expressed as percentage of the current German recommendations. Food products were defined as fortified if enriched with at least one of the following nutrients: Vitamin A or provitamin A carotenoids (summarised as Vitamin A), Vitamins E, B1, B2, B6, C, niacin, folate, calcium or iron. Nutrient supplements and medicine were excluded from this evaluation. Time trends were analysed using linear and non-linear regression models (PROC MIXED, SAS 6.12). In percent of German references [3], non-fortified food contributed to folate intake by 20-30%, to Vitamin E by about 40%, to Vitamin B1 by 50-65%, to Vitamin A, C, B2, calcium, iron by about 65-95%, and to Vitamin B6 and niacin intake by 100% and more. Fortified food alone provided no more than 5% of calcium intake, about 10-20% of iron, Vitamin A and folate intake, up to 40-50% of Vitamin C, B1, B2, E, niacin and up to 80% of Vitamin B6 intake. During the 15 year period of the DONALD Study with total food, we only found a significant linear time trend for Vitamin C, whereas significant non-linear time trends were found for calcium, Vitamin E, B1, B2, B6, niacin and folate. In the latter there was a uniform increase until 1994 and a decrease thereafter. For iron and Vitamin A no significant time trend could be identified. Only iron and Vitamin A intake from fortified food showed a significant linear time trend. All other nutrients studied here gave significant non-linear time trends. Nutrient intake with fortified food reached maximum values between 1994 and 1996 followed by a decrease thereafter. Signs of changing food consumption patterns were found, pointing to an almost uniform decrease of nutrient intake since 1994/96 in our population of German children and adolescents. This could be an alarming indicator of a slight but unpreferable tendency to eat energydense, nutrient-poor foods.
Trends in mouth cancer incidence in Mumbai, India (1995-2009): An age-period-cohort analysis.
Shridhar, Krithiga; Rajaraman, Preetha; Koyande, Shravani; Parikh, Purvish M; Chaturvedi, Pankaj; Dhillon, Preet K; Dikshit, Rajesh P
2016-06-01
Despite tobacco control and health promotion efforts, the incidence rates of mouth cancer are increasing across most regions in India. Analysing the influence of age, time period and birth cohort on these secular trends can point towards underlying factors and help identify high-risk populations for improved cancer control programmes. We evaluated secular changes in mouth cancer incidence among men and women aged 25-74 years in Mumbai between 1995 and 2009 by calculating age-specific and age-standardized incidence rates (ASR). We estimated the age-adjusted linear trend for annual percent change (EAPC) using the drift parameter, and conducted an age-period-cohort (APC) analysis to quantify recent time trends and to evaluate the significance of birth cohort and calendar period effects. Over the 15-year period, age-standardized incidence rates of mouth cancer in men in Mumbai increased by 2.7% annually (95% CI:1.9 to 3.4), p<0.0001) while rates among women decreased (EAPC=-0.01% (95% CI:-0.02 to -0.002), p=0.03). APC analysis revealed significant non-linear positive period and cohort effects in men, with higher effects among younger men (25-49 years). Non-significant increasing trends were observed in younger women (25-49 years). APC analyses from the Mumbai cancer registry indicate a significant linear increase of mouth cancer incidence from 1995 to 2009 in men, which was driven by younger men aged 25-49 years, and a non-significant upward trend in similarly aged younger women. Health promotion efforts should more effectively target younger cohorts. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.
Trends in bullying victimization by gender among U.S. high school students.
Pontes, Nancy M H; Ayres, Cynthia G; Lewandowski, Carla; Pontes, Manuel C F
2018-06-01
This research used four consecutive waves of data from the National Youth Risk Behavior Survey (YRBS) conducted by the Centers for Disease Control (CDC), to estimate linear time trends by gender in the prevalence of school and electronic bullying victimization among U.S. high school students (N = 61,042). Dependent variables were student self-reported school bullying victimization and electronic bullying victimization during the previous 12 months. Independent variables used to estimate multiple logistic regression models by gender were survey year, race/ethnicity, and grade level. Results showed the prevalence of school bullying increased significantly among females from 2009 (21.2%) to 2015 (24.8%), linear trend OR = 1.08 [1.04, 1.12]; and decreased significantly among males from 2009 (18.7%) to 2015 (15.8%), linear trend OR = 0.93 [0.89, 0.98]. Prevalence of electronic bullying was unchanged between 2011 to 2015 among both male and female students. Asian race, relative to White race, was associated with significantly lower rates of both school and electronic bullying victimization among females, but not males. The incidence of school and electronic bullying victimization was significantly lower among Black and Hispanic students, but not among multiple-race students, regardless of student gender. Healthy People 2020 set a goal to reduce school bullying victimization 10% by 2019. As of 2015, school bullying victimization decreased significantly among males (16% decrease); it significantly increased among females (17% increase). Future research should explore underlying factors related to these divergent trends, and develop effective strategies to reverse the alarming rise in female school bullying victimization. © 2018 Wiley Periodicals, Inc.
NASA Astrophysics Data System (ADS)
Wang, Cailin; Wu, Jidong; Wang, Xu; He, Xin; Li, Ning
2017-12-01
North China Plain has undergone severe warming trends since the 1950s, but whether this trend is the same during different growth phases for crops remains unknown. Thus, we analyzed the non-linear changes in the minimum temperature (T min ), mean temperature (T mean ) and maximum temperature (T max ) using the Ensemble Empirical Mode Decomposition method during each growth stage of summer maize based on daily temperature data from 1960 to 2014. Our results strongly suggest that the trends and fluctuations in temperature change are non-linear. These changes can be categorized into four types of trend change according to the combinations of decreasing and increasing trends, and 8 fluctuation modes dominated by the fluctuations of expansion and shrinkage. The amplitude of the fluctuation is primarily expansion in the sowing-jointing stage and shrinkage in the jointing-maturity stage. Moreover, the temperature changes are inconsistent within each growth stage and are not consistent with the overall warming trend observed over the last 55 years. A transition period occurred in both the 1980s and the 1990s for temperatures during the sowing-tasseling stage. Furthermore, the cooling trend of the T max was significant in the sowing-emergence stage, while this cooling trend was not obvious for both T mean and T min in the jointing-tasseling stage. These results showed that temperature change was significantly different in different stages of the maize growth season. The results can serve as a scientific basis for a better understanding of the actual changes in the regional surface air temperature and agronomic heat resources.
2013-01-01
Background A longitudinal repeated measures design over pregnancy and post-birth, with a control group would provide insight into the mechanical adaptations of the body under conditions of changing load during a common female human lifespan condition, while minimizing the influences of inter human differences. The objective was to investigate systematic changes in the range of motion for the pelvic and thoracic segments of the spine, the motion between these segments (thoracolumbar spine) and temporospatial characteristics of step width, stride length and velocity during walking as pregnancy progresses and post-birth. Methods Nine pregnant women were investigated when walking along a walkway at a self-selected velocity using an 8 camera motion analysis system on four occasions throughout pregnancy and once post birth. A control group of twelve non-pregnant nulliparous women were tested on three occasions over the same time period. The existence of linear trends for change was investigated. Results As pregnancy progresses there was a significant linear trend for increase in step width (p = 0.05) and a significant linear trend for decrease in stride length (p = 0.05). Concurrently there was a significant linear trend for decrease in the range of motion of the pelvic segment (p = 0.03) and thoracolumbar spine (p = 0.01) about a vertical axis (side to side rotation), and the pelvic segment (p = 0.04) range of motion around an anterio-posterior axis (side tilt). Post-birth, step width readapted whereas pelvic (p = 0.02) and thoracic (p < 0.001) segment flexion-extension range of motion decreased and increased respectively. The magnitude of all changes was greater than that accounted for with natural variability with re testing. Conclusions As pregnancy progressed and post-birth there were significant linear trends seen in biomechanical changes when walking at a self-determined natural speed that were greater than that accounted for by natural variability with repeated testing. Not all adaptations were resolved by eight weeks post birth. PMID:23514204
Space-time patterns of trends in stratospheric constituents derived from UARS measurements
NASA Astrophysics Data System (ADS)
Randel, William J.; Wu, Fei; Russell, James M.; Waters, Joe
1999-02-01
The spatial and temporal behavior of low-frequency changes (trends) in stratospheric constituents measured by instruments on the Upper Atmosphere Research Satellite (UARS) during 1991-98 is investigated. The data include CH4, H2O, HF, HCl, O3, and NO2 from the Halogen Occultation Experiment (HALOE), and O3, ClO, and HNO3 from the Microwave Limb Sounder (MLS). Time series of global anomalies are analyzed by linear regression and empirical orthogonal function analysis. Each of the constituents show significant linear trends over at least some region of the stratosphere, and the spatial patterns exhibit coupling between the different species. Several of the constituents (namely CH4, H2O, HF, HCl, O3, and NO2) exhibit a temporal change in trend rates, with strong changes prior to 1996 and weaker (or reversed) trends thereafter. Positive trends are observed in upper stratospheric ClO, with a percentage rate during 1993-97 consistent with stratospheric HCl increases and with tropospheric chlorine emission rates. Significant negative trends in ozone in the tropical middle stratosphere are found in both HALOE and MLS data during 1993-97, together with positive trends in the tropics near 25 km. These trends are very different from the decadal-scale ozone trends observed since 1979, and this demonstrates the variability of trends calculated over short time periods. Positive trends in NO2 are found in the tropical middle stratosphere, and spatial coincidence to the observed ozone decreases suggests the ozone is responding to the NO2 increase. Significant negative trends in HNO3 are found in the lower stratosphere of both hemispheres. These coupled signatures offer a fingerprint of chemical evolution in the stratosphere for the UARS time frame.
Structural and lithologic study of northern coast ranges and Sacramento Valley, California
NASA Technical Reports Server (NTRS)
Rich, E. I. (Principal Investigator)
1973-01-01
The author has identified the following significant results. The pattern of linear systems within the project area has been extended into the western foothill belt of the Sierra Nevada. The chief pattern of linear features in the western Sierran foothill belt trends about N. 10 - 15 deg W., but in the vicinity of the Feather River the trend of the features abruptly changes to about N. 50-60 deg W and appears to be contiguous across the Sacramento Valley with a similar system of linear features in the Coast Ranges. The linear features in the Modoc Plateau and Klamath Mt. areas appear unrelated to the systems detected in the Coast Ranges of Sierran foothill belt. Although the change in trend of the Sierran structural features has been previously suggested and the interrelationship of the Klamath Mt. region with the northern Sierra Nevadas has been postulated, the data obtained from the ERTS-1 imagery strengthens these notions and provides for the first time evidence of a direct connection of the structural trends within the alluviated part of the Sacramento Valley. In addition rocks of Pleistocene and Holocene age are offset by some of the linear features seen on ERTS-1 imagery and hence may record the latest episode of geologic deformation in north-central California.
Znachor, Petr; Nedoma, Jiří; Hejzlar, Josef; Seďa, Jaromír; Kopáček, Jiří; Boukal, David; Mrkvička, Tomáš
2018-05-15
Man-made reservoirs are common across the world and provide a wide range of ecological services. Environmental conditions in riverine reservoirs are affected by the changing climate, catchment-wide processes and manipulations with the water level, and water abstraction from the reservoir. Long-term trends of environmental conditions in reservoirs thus reflect a wider range of drivers in comparison to lakes, which makes the understanding of reservoir dynamics more challenging. We analysed a 32-year time series of 36 environmental variables characterising weather, land use in the catchment, reservoir hydrochemistry, hydrology and light availability in the small, canyon-shaped Římov Reservoir in the Czech Republic to detect underlying trends, trend reversals and regime shifts. To do so, we fitted linear and piecewise linear regression and a regime shift model to the time series of mean annual values of each variable and to principal components produced by Principal Component Analysis. Models were weighted and ranked using Akaike information criterion and the model selection approach. Most environmental variables exhibited temporal changes that included time-varying trends and trend reversals. For instance, dissolved organic carbon showed a linear increasing trend while nitrate concentration or conductivity exemplified trend reversal. All trend reversals and cessations of temporal trends in reservoir hydrochemistry (except total phosphorus concentrations) occurred in the late 1980s and during 1990s as a consequence of dramatic socioeconomic changes. After a series of heavy rains in the late 1990s, an administrative decision to increase the flood-retention volume of the reservoir resulted in a significant regime shift in reservoir hydraulic conditions in 1999. Our analyses also highlight the utility of the model selection framework, based on relatively simple extensions of linear regression, to describe temporal trends in reservoir characteristics. This approach can provide a solid basis for a better understanding of processes in freshwater reservoirs. Copyright © 2017 Elsevier B.V. All rights reserved.
Li, Jie; Li, Rui; You, Leiming; Xu, Anlong; Fu, Yonggui; Huang, Shengfeng
2015-01-01
Switching between different alternative polyadenylation (APA) sites plays an important role in the fine tuning of gene expression. New technologies for the execution of 3’-end enriched RNA-seq allow genome-wide detection of the genes that exhibit significant APA site switching between different samples. Here, we show that the independence test gives better results than the linear trend test in detecting APA site-switching events. Further examination suggests that the discrepancy between these two statistical methods arises from complex APA site-switching events that cannot be represented by a simple change of average 3’-UTR length. In theory, the linear trend test is only effective in detecting these simple changes. We classify the switching events into four switching patterns: two simple patterns (3’-UTR shortening and lengthening) and two complex patterns. By comparing the results of the two statistical methods, we show that complex patterns account for 1/4 of all observed switching events that happen between normal and cancerous human breast cell lines. Because simple and complex switching patterns may convey different biological meanings, they merit separate study. We therefore propose to combine both the independence test and the linear trend test in practice. First, the independence test should be used to detect APA site switching; second, the linear trend test should be invoked to identify simple switching events; and third, those complex switching events that pass independence testing but fail linear trend testing can be identified. PMID:25875641
Filippidis, Filippos T; Agaku, Israel T; Connolly, Gregory N; Vardavas, Constantine I
2014-04-01
This study assessed trends in age verification prior to cigarette sales to U.S. middle and high school students, and refusal to sell cigarettes to students aged <18 years during 2000-2009. Data were obtained from the 2000-2009 National Youth Tobacco Survey. Trends during 2000-2009 were assessed using binary logistic regression (p<0.05). The proportion of all students, who reported being asked to show proof of age prior to a cigarette purchase in the past 30 days did not change significantly between 2000 (46.9%) and 2009 (44.9%) (p=0.529 for linear trend). No significant trend in the proportion of students aged < 18 years who were refused a sale when attempting to buy cigarettes was observed between 2000 (39.8%) and 2009 (36.7%) (p=0.283 for linear trend). Refusal of a cigarette sale was significantly higher among under-aged boys compared to girls (adjusted odds ratio=1.48; 95% confidence interval: 1.28-1.70). About half of U.S. middle and high school students who reported making a cigarette purchase were not asked for proof of age, and about three of five under-aged buyers successfully made a cigarette purchase in 2009. Intensified implementation and enforcement of policies requiring age verification among youths is warranted to reduce access and use of tobacco products. Copyright © 2014 Elsevier Inc. All rights reserved.
Rice, Karen C.; Hirsch, Robert M.
2012-01-01
Long-term streamflow data within the Chesapeake Bay watershed and surrounding area were analyzed in an attempt to identify trends in streamflow. Data from 30 streamgages near and within the Chesapeake Bay watershed were selected from 1930 through 2010 for analysis. Streamflow data were converted to runoff and trend slopes in percent change per decade were calculated. Trend slopes for three runoff statistics (the 7-day minimum, the mean, and the 1-day maximum) were analyzed annually and seasonally. The slopes also were analyzed both spatially and temporally. The spatial results indicated that trend slopes in the northern half of the watershed were generally greater than those in the southern half. The temporal analysis was done by splitting the 80-year flow record into two subsets; records for 28 streamgages were analyzed for 1930 through 1969 and records for 30 streamgages were analyzed for 1970 through 2010. The mean of the data for all sites for each year were plotted so that the following datasets were analyzed: the 7-day minimum runoff for the north, the 7-day minimum runoff for the south, the mean runoff for the north, the mean runoff for the south, the 1-day maximum runoff for the north, and the 1-day maximum runoff for the south. Results indicated that the period 1930 through 1969 was statistically different from the period 1970 through 2010. For the 7-day minimum runoff and the mean runoff, the latter period had significantly higher streamflow than did the earlier period, although within those two periods no significant linear trends were identified. For the 1-day maximum runoff, no step trend or linear trend could be shown to be statistically significant for the north, although the south showed a mixture of an upward step trend accompanied by linear downtrends within the periods. In no case was a change identified that indicated an increasing rate of change over time, and no general pattern was identified of hydrologic conditions becoming "more extreme" over time.
NASA Astrophysics Data System (ADS)
Guo, Enliang; Zhang, Jiquan; Wang, Yongfang; Alu, Si; Wang, Rui; Li, Danjun; Ha, Si
2018-05-01
In the past two decades, the regional climate in China has undergone significant change, resulting in crop yield reduction and complete failure. The goal of this study is to detect the variation of temperature and precipitation for different growth periods of maize and assess their impact on phenology. The daily meteorological data in the Midwest of Jilin Province during 1960-2014 were used in the study. The ensemble empirical mode decomposition method was adopted to analyze the non-linear trend and fluctuation in temperature and precipitation, and the sensitivity of the length of the maize growth period to temperature and precipitation was analyzed by the wavelet cross-transformation method. The results show that the trends of temperature and precipitation change are non-linear for different growth periods of maize, and the average temperature in the sowing-jointing stage was different from that in the other growth stages, showing a slight decrease trend, while the variation amplitude of maximum temperature is smaller than that of the minimum temperature. This indicates that the temperature difference between day and night shows a gradually decreasing trend. Precipitation in the growth period also showed a decreasing non-linear trend, while the inter-annual variability with period of quasi-3-year and quasi-6-year dominated the variation of temperature and precipitation. The whole growth period was shortened by 10.7 days, and the sowing date was advanced by approximately 11 days. We also found that there was a significant resonance period among temperature, precipitation, and phenology. Overall, a negative correlation between phenology and temperature is evident, while a positive correlation with precipitation is exhibited. The results illustrate that the climate suitability for maize has reduced over the past decades.
Arai, Shizuha; Nakaya, Naoki; Kakizaki, Masako; Ohmori-Matsuda, Kaori; Shimazu, Taichi; Kuriyama, Shinichi; Fukao, Akira; Tsuji, Ichiro
2009-01-01
Objective To determine the associations between personality subscales and attendance at gastric cancer screenings in Japan. Methods A total of 21,911 residents in rural Japan who completed a short form of the Eysenck Personality Questionnaire-Revised (EPQ-R) and a questionnaire on various health habits including the number of gastric cancer screenings attended were included in the primary analysis. We defined gastric cancer screening compliance as attendance at gastric cancer screening every year for the previous 5 years; all other patterns of attendance were defined as non-compliance. We defined gastric cancer screening visiting as attendance at 1 or more screenings during the previous 5 years; lack of attendance was defined as non-visiting. We used logistic regression to estimate the odds ratios (ORs) of gastric cancer screening compliance and visiting according to 4 score levels that corresponded to the 4 EPQ-R subscales (extraversion, neuroticism, psychoticism, and lie). Result Extraversion had a significant linear, positive association with both compliance and visiting (trend, P < 0.001 for both). Neuroticism had a significant linear, inverse association with compliance (trend, P = 0.047), but not with visiting (trend, P = 0.21). Psychoticism had a significant linear, inverse association with both compliance and visiting (trend, P < 0.001 for both). Lie had no association with either compliance or visiting. Conclusion The personality traits of extraversion, neuroticism, and psychoticism were significantly associated with gastric cancer screening attendance. A better understanding of the association between personality and attendance could lead to the establishment of effective campaigns to motivate people to attend cancer screenings. PMID:19164872
NASA Astrophysics Data System (ADS)
Machiwal, Deepesh; Gupta, Ankit; Jha, Madan Kumar; Kamble, Trupti
2018-04-01
This study investigated trends in 35 years (1979-2013) temperature (maximum, Tmax and minimum, Tmin) and rainfall at annual and seasonal (pre-monsoon, monsoon, post-monsoon, and winter) scales for 31 grid points in a coastal arid region of India. Box-whisker plots of annual temperature and rainfall time series depict systematic spatial gradients. Trends were examined by applying eight tests, such as Kendall rank correlation (KRC), Spearman rank order correlation (SROC), Mann-Kendall (MK), four modified MK tests, and innovative trend analysis (ITA). Trend magnitudes were quantified by Sen's slope estimator, and a new method was adopted to assess the significance of linear trends in MK-test statistics. It was found that the significant serial correlation is prominent in the annual and post-monsoon Tmax and Tmin, and pre-monsoon Tmin. The KRC and MK tests yielded similar results in close resemblance with the SROC test. The performance of two modified MK tests considering variance-correction approaches was found superior to the KRC, MK, modified MK with pre-whitening, and ITA tests. The performance of original MK test is poor due to the presence of serial correlation, whereas the ITA method is over-sensitive in identifying trends. Significantly increasing trends are more prominent in Tmin than Tmax. Further, both the annual and monsoon rainfall time series have a significantly increasing trend of 9 mm year-1. The sequential significance of linear trend in MK test-statistics is very strong (R 2 ≥ 0.90) in the annual and pre-monsoon Tmin (90% grid points), and strong (R 2 ≥ 0.75) in monsoon Tmax (68% grid points), monsoon, post-monsoon, and winter Tmin (respectively 65, 55, and 48% grid points), as well as in the annual and monsoon rainfalls (respectively 68 and 61% grid points). Finally, this study recommends use of variance-corrected MK test for the precise identification of trends. It is emphasized that the rising Tmax may hamper crop growth due to enhanced metabolic-activities and shortened crop-duration. Likewise, increased Tmin may result in lesser crop and biomass yields owing to the increased respiration.
Bruyndonckx, Robin; Hens, Niel; Aerts, Marc; Goossens, Herman; Molenberghs, Geert; Coenen, Samuel
2014-07-01
To complement analyses of the linear trend and seasonal fluctuation of European outpatient antibiotic use expressed in defined daily doses (DDD) by analyses of data in packages, to assess the agreement between both measures and to study changes in the number of DDD per package over time. Data on outpatient antibiotic use, aggregated at the level of the active substance (WHO version 2011) were collected from 2000 to 2007 for 31 countries and expressed in DDD and packages per 1000 inhabitants per day (DID and PID, respectively). Data expressed in DID and PID were analysed separately using non-linear mixed models while the agreement between these measurements was analysed through a joint non-linear mixed model. The change in DDD per package over time was studied with a linear mixed model. Total outpatient antibiotic and penicillin use in Europe and their seasonal fluctuation significantly increased in DID, but not in PID. The use of combinations of penicillins significantly increased in DID and in PID. Broad-spectrum penicillin use did not increase significantly in DID and decreased significantly in PID. For all but one subgroup, country-specific deviations moved in the same direction whether measured in DID or PID. The correlations are not perfect. The DDD per package increased significantly over time for all but one subgroup. Outpatient antibiotic use in Europe shows contrasting trends, depending on whether DID or PID is used as the measure. The increase of the DDD per package corroborates the recommendation to adopt PID to monitor outpatient antibiotic use in Europe. © The Author 2014. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
NASA Technical Reports Server (NTRS)
Gryc, G. (Principal Investigator); Lathram, E. H.
1972-01-01
The authors have identified the following significant results. As a precursor to the ERTS-1 investigation, the spatial relationship of geostructures seen on Nimbus IDCS photographs to the distribution of mineralized areas in Alaska and western Canada was analyzed to determine the possible metallogenic significance of the geostructures. In Canada, mercury and porphyry molybdenum deposits are closely associated with strong northwest-trending fault systems; the development of mineralized regions seems related to major crustal zones or fractures trending southwestward across the Cordillera from the Precambrian shield. In Alaska, comparison of the northeast- and northwest-trending set of possible crustal structures shown on the Nimbus photo, with the distribution of known mineral deposits suggests a similar relationship. The mineralized region of massive sulfides in Prince William Sound and upper Copper River areas and of porphyry coppers in the Nabesna area forms a broad northeast-trending belt possibly related to the Minto Arch on the Shield. The belt of metalliferous deposits in the western Alaska Range follows a comparable northeast trend. Mercury deposits, suggested by many to be fault-controlled, together with most tin and tungsten deposits, occupy a northeast-trending belt between the Bristol Bay-Mackenzie Bay linear and extensions of a linear along the lower Yukon River. This belt intersects the northwest-trending Canadian belt of similar deposits in the Fairbanks area.
Wang, D Z; Wang, C; Shen, C F; Zhang, Y; Zhang, H; Song, G D; Xue, X D; Xu, Z L; Zhang, S; Jiang, G H
2017-05-10
We described the time trend of acute myocardial infarction (AMI) from 1999 to 2013 in Tianjin incidence rate with Cochran-Armitage trend (CAT) test and linear regression analysis, and the results were compared. Based on actual population, CAT test had much stronger statistical power than linear regression analysis for both overall incidence trend and age specific incidence trend (Cochran-Armitage trend P value
NASA Astrophysics Data System (ADS)
Baldysz, Zofia; Nykiel, Grzegorz; Figurski, Mariusz; Szafranek, Karolina; Kroszczynski, Krzysztof; Araszkiewicz, Andrzej
2015-04-01
In recent years, the GNSS system began to play an increasingly important role in the research related to the climate monitoring. Based on the GPS system, which has the longest operational capability in comparison with other systems, and a common computational strategy applied to all observations, long and homogeneous ZTD (Zenith Tropospheric Delay) time series were derived. This paper presents results of analysis of 16-year ZTD time series obtained from the EPN (EUREF Permanent Network) reprocessing performed by the Military University of Technology. To maintain the uniformity of data, analyzed period of time (1998-2013) is exactly the same for all stations - observations carried out before 1998 were removed from time series and observations processed using different strategy were recalculated according to the MUT LAC approach. For all 16-year time series (59 stations) Lomb-Scargle periodograms were created to obtain information about the oscillations in ZTD time series. Due to strong annual oscillations which disturb the character of oscillations with smaller amplitude and thus hinder their investigation, Lomb-Scargle periodograms for time series with the deleted annual oscillations were created in order to verify presence of semi-annual, ter-annual and quarto-annual oscillations. Linear trend and seasonal components were estimated using LSE (Least Square Estimation) and Mann-Kendall trend test were used to confirm the presence of linear trend designated by LSE method. In order to verify the effect of the length of time series on the estimated size of the linear trend, comparison between two different length of ZTD time series was performed. To carry out a comparative analysis, 30 stations which have been operating since 1996 were selected. For these stations two periods of time were analyzed: shortened 16-year (1998-2013) and full 18-year (1996-2013). For some stations an additional two years of observations have significant impact on changing the size of linear trend - only for 4 stations the size of linear trend was exactly the same for two periods of time. In one case, the nature of the trend has changed from negative (16-year time series) for positive (18-year time series). The average value of a linear trends for 16-year time series is 1,5 mm/decade, but their spatial distribution is not uniform. The average value of linear trends for all 18-year time series is 2,0 mm/decade, with better spatial distribution and smaller discrepancies.
Uncertainty in detecting trend: a new criterion and its applications to global SST
NASA Astrophysics Data System (ADS)
Lian, Tao
2017-10-01
In most parts of the global ocean, the magnitude of the long-term linear trend in sea surface temperature (SST) is much smaller than the amplitude of multi-scale internal variation. One can thus use a specific period in a much longer record to arbitrarily determine the sign of long-term trend, which is statistically significant, in regional SST. This could lead to a controversial conclusion on how global SST responded to the anthropogenic forcing in the recent history. In this study, the uncertainty in the linear trend due to multi-scale internal variation is theoretically investigated. It is found that the "estimated" trend will not change its sign only when its magnitude is greater than a theoretical threshold that scales the influence from the multi-scale internal variation. Otherwise, the sign of the "estimated" trend may depend on the period used. The new criterion is found to be superior over the existing methods when the de-trended time series is dominated by the oscillatory term. Applying this new criterion to a global SST reconstruction from 1881 to 2013 reveals that the influences from multi-scale internal variation on the sign of "estimated" linear trend cannot be excluded in most parts of the Pacific, the southern Indian Ocean and the northern Atlantic; therefore, the warming or/and cooling trends found in these regions cannot be interpreted as the consequences of anthropogenic forcing. It's also suggested that the recent hiatus can be explained by combined uncertainty from internal variations at the interannual and decadal time scales.
Uncertainty in Detecting Trend: A New Criterion and Its Applications to Global SST
NASA Astrophysics Data System (ADS)
Lian, Tao
2017-04-01
In most parts of the global ocean, the magnitude of the long-term linear trend in sea surface temperature (SST) is much smaller than the amplitude of multi-scale internal variation. One can thus use a specific period in a much longer record to arbitrarily determine the sign of long-term trend, which is statistically significant, in regional SST. This could lead to a controversial conclusion on how global SST responded to the anthropogenic forcing in the recent history. In this study, the uncertainty in the linear trend due to multi-scale internal variation is theoretically investigated. It is found that the "estimated" trend will not change its sign only when its magnitude is greater than a theoretical threshold that scales the influence from the multi-scale internal variation. Otherwise, the sign of the "estimated" trend may depend on the period used. The new criterion is found to be superior over the existing methods when the de-trended time series is dominated by the oscillatory term. Applying this new criterion to a global SST reconstruction from 1881 to 2013 reveals that the influences from multi-scale internal variation on the sign of "estimated" linear trend cannot be excluded in most parts of the Pacific, the southern Indian Ocean and the northern Atlantic; therefore, the warming or/and cooling trends found in these regions cannot be interpreted as the consequences of anthropogenic forcing. It's also suggested that the recent hiatus can be explained by combined uncertainty from internal variations at the interannual and decadal time scales.
Rusakaniko, S; Mbizvo, M T; Kasule, J; Gupta, V; Kinoti, S N; Mpanju-Shumbushu, W; Sebina-Zziwa, J; Mwateba, R; Padayachy, J
1997-01-01
Unwanted teenage pregnancy, sexually transmitted infections and the attendant morbidity and mortality necessitate the need for understanding factors influencing adolescent sexuality and the implementation of programmes designed to improve their knowledge, reproductive behaviour, sexual and reproductive health. To determine the impact of an intervention package on knowledge levels of various reproductive health issues through trend analysis. Randomized controlled trial of a health education intervention in schools stratified for representativeness. Rural and urban secondary schools in Zimbabwe. 1,689 students recruited from 11 secondary schools in Mashonaland Central. Knowledge level before and after intervention. The demographic characteristics of the pupils at baseline, five months and nine months were comparable between the two groups. There was an overall increase in knowledge on menstruation. Students from the intervention schools were more likely to have correct knowledge over time on aspects of reproductive biology. A significant linear trend (p = 0.017) was observed in the area of family planning and contraception. A linear decreasing trend (p = 0.001) was observed on pregnancy risk. Though not significantly linear, the general trend of knowledge levels in all the areas of reproductive health, pregnancy risk, STDs and HIV/AIDS showed an upward trend, from 20% to 96%. Worth noting was that in all the areas the intervention group had knowledge above that in the control group. The reproductive health education intervention had an impact on aspects of reproductive biology and contraception as measured by the increased scoring at follow up when comparing intervention and control schools. The overall findings point to the need for early school based reproductive health education programmes incooperating correct information on reproductive biology and the prevention of subsequent reproductive morbidity by imparting information on non-risk behaviour during the early developmental years.
Saccomandi, Paola; Varalda, Ambra; Gassino, Riccardo; Tosi, Daniele; Massaroni, Carlo; Caponero, Michele A; Pop, Raoul; Korganbayev, Sanzhar; Perrone, Guido; Diana, Michele; Vallan, Alberto; Costamagna, Guido; Marescaux, Jacques; Schena, Emiliano
2017-09-01
The response of a fiber optic sensor [linearly chirped fiber Bragg grating (LCFBG)] to a linear thermal gradient applied on its sensing length (i.e., 1.5 cm) has been investigated. After these bench tests, we assessed their feasibility for temperature monitoring during thermal tumor treatment. In particular, we performed experiments during ex vivo laser ablation (LA) in pig liver and in vivo thermal ablation in animal models (pigs). We investigated the following: (i) the relationship between the full width at half maximum of the LCFBG spectrum and the temperature difference among the extremities of the LCFBG and (ii) the relationship between the mean spectrum wavelength and the mean temperature acting on the LCFBG sensing area. These relationships showed a linear trend during both bench tests and LA in animal models. Thermal sensitivity was significant although different values were found with regards to bench tests and animal experiments. The linear trend and significant sensitivity allow hypothesizing a future use of this kind of sensor to monitor both temperature gradient and mean temperature within a tissue undergoing thermal treatment. (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).
The Uncertainty of Long-term Linear Trend in Global SST Due to Internal Variation
NASA Astrophysics Data System (ADS)
Lian, Tao
2016-04-01
In most parts of the global ocean, the magnitude of the long-term linear trend in sea surface temperature (SST) is much smaller than the amplitude of local multi-scale internal variation. One can thus use the record of a specified period to arbitrarily determine the value and the sign of the long-term linear trend in regional SST, and further leading to controversial conclusions on how global SST responds to global warming in the recent history. Analyzing the linear trend coefficient estimated by the ordinary least-square method indicates that the linear trend consists of two parts: One related to the long-term change, and the other related to the multi-scale internal variation. The sign of the long-term change can be correctly reproduced only when the magnitude of the linear trend coefficient is greater than a theoretical threshold which scales the influence from the multi-scale internal variation. Otherwise, the sign of the linear trend coefficient will depend on the phase of the internal variation, or in the other words, the period being used. An improved least-square method is then proposed to reduce the theoretical threshold. When apply the new method to a global SST reconstruction from 1881 to 2013, we find that in a large part of Pacific, the southern Indian Ocean and North Atlantic, the influence from the multi-scale internal variation on the sign of the linear trend coefficient can-not be excluded. Therefore, the resulting warming or/and cooling linear trends in these regions can-not be fully assigned to global warming.
Geomorphic domains and linear features on Landsat images, Circle Quadrangle, Alaska
Simpson, S.L.
1984-01-01
A remote sensing study using Landsat images was undertaken as part of the Alaska Mineral Resource Assessment Program (AMRAP). Geomorphic domains A and B, identified on enhanced Landsat images, divide Circle quadrangle south of Tintina fault zone into two regional areas having major differences in surface characteristics. Domain A is a roughly rectangular, northeast-trending area of relatively low relief and simple, widely spaced drainages, except where igneous rocks are exposed. In contrast, domain B, which bounds two sides of domain A, is more intricately dissected showing abrupt changes in slope and relatively high relief. The northwestern part of geomorphic domain A includes a previously mapped tectonostratigraphic terrane. The southeastern boundary of domain A occurs entirely within the adjoining tectonostratigraphic terrane. The sharp geomorphic contrast along the southeastern boundary of domain A and the existence of known faults along this boundary suggest that the southeastern part of domain A may be a subdivision of the adjoining terrane. Detailed field studies would be necessary to determine the characteristics of the subdivision. Domain B appears to be divisible into large areas of different geomorphic terrains by east-northeast-trending curvilinear lines drawn on Landsat images. Segments of two of these lines correlate with parts of boundaries of mapped tectonostratigraphic terranes. On Landsat images prominent north-trending lineaments together with the curvilinear lines form a large-scale regional pattern that is transected by mapped north-northeast-trending high-angle faults. The lineaments indicate possible lithlogic variations and/or structural boundaries. A statistical strike-frequency analysis of the linear features data for Circle quadrangle shows that northeast-trending linear features predominate throughout, and that most northwest-trending linear features are found south of Tintina fault zone. A major trend interval of N.64-72E. in the linear feature data, corresponds to the strike of foliations in metamorphic rocks and magnetic anomalies reflecting compositional variations suggesting that most linear features in the southern part of the quadrangle probably are related to lithologic variations brought about by folding and foliation of metamorphic rocks. A second important trend interval, N.14-35E., may be related to thrusting south of the Tintina fault zone, as high concentrations of linear features within this interval are found in areas of mapped thrusts. Low concentrations of linear features are found in areas of most igneous intrusives. High concentrations of linear features do not correspond to areas of mineralization in any consistent or significant way that would allow concentration patterns to be easily used as an aid in locating areas of mineralization. The results of this remote sensing study indicate that there are several possibly important areas where further detailed studies are warranted.
NASA Astrophysics Data System (ADS)
Unnikrishnan, Poornima; Jothiprakash, Vinayakam
2017-04-01
Precipitation is the major component in the hydrologic cycle. Awareness of not only the total amount of rainfall pertaining to a catchment, but also the pattern of its spatial and temporal distribution are equally important in the management of water resources systems in an efficient way. Trend is the long term direction of a time series; it determines the overall pattern of a time series. Singular Spectrum Analysis (SSA) is a time series analysis technique that decomposes the time series into small components (eigen triples). This property of the method of SSA has been utilized to extract the trend component of the rainfall time series. In order to derive trend from the rainfall time series, we need to select components corresponding to trend from the eigen triples. For this purpose, periodogram analysis of the eigen triples have been proposed to be coupled with SSA, in the present study. In the study, seasonal data of England and Wales Precipitation (EWP) for a time period of 1766-2013 have been analyzed and non linear trend have been derived out of the precipitation data. In order to compare the performance of SSA in deriving trend component, Mann Kendall (MK) test is also used to detect trends in EWP seasonal series and the results have been compared. The result showed that the MK test could detect the presence of positive or negative trend for a significance level, whereas the proposed methodology of SSA could extract the non-linear trend present in the rainfall series along with its shape. We will discuss further the comparison of both the methodologies along with the results in the presentation.
Ussery, Emily N; Carlson, Susan A; Whitfield, Geoffrey P; Watson, Kathleen B; Berrigan, David; Fulton, Janet E
2017-06-30
Physical activity confers considerable health benefits, but only half of U.S. adults report participating in levels of aerobic physical activity consistent with guidelines (1,2). Step It Up! The Surgeon General's Call to Action to Promote Walking and Walkable Communities identified walking as an important public health strategy to increase physical activity levels (3). A previous report showed that the self-reported prevalence of walking for transportation or leisure increased by 6 percentage points from 2005 to 2010 (4), but it is unknown whether this increase has been sustained. CDC analyzed National Health Interview Survey (NHIS) data from 2005 (26,551 respondents), 2010 (23,313), and 2015 (28,877) to evaluate trends in the age-adjusted prevalence of self-reported walking among adults aged ≥18 years. The prevalence of walking increased steadily among women, from 57.3% in 2005, to 62.5% in 2010, and to 65.1% in 2015 (significant linear trend). Among men, a significant linear increase in reported walking was observed, from 54.3% in 2005, to 61.8% in 2010, and to 62.8% in 2015, although the increase stalled between 2010 and 2015 (significant linear and quadratic trends). Community design policies and practices that encourage pedestrian activity and programs tailored to the needs of specific population subgroups remain important strategies for promoting walking (3).
The intra-day dynamics of affect, self-esteem, tiredness, and suicidality in Major Depression.
Crowe, Eimear; Daly, Michael; Delaney, Liam; Carroll, Susan; Malone, Kevin M
2018-02-21
Despite growing interest in the temporal dynamics of Major Depressive Disorder (MDD), we know little about the intra-day fluctuations of key symptom constructs. In a study of momentary experience, the Experience Sampling Method captured the within-day dynamics of negative affect, positive affect, self-esteem, passive suicidality, and tiredness across clinical MDD (N= 31) and healthy control groups (N= 33). Ten symptom measures were taken per day over 6 days (N= 2231 observations). Daily dynamics were modeled via intra-day time-trends, variability, and instability in symptoms. MDD participants showed significantly increased variability and instability in negative affect, positive affect, self-esteem, and suicidality. Significantly different time-trends were found in positive affect (increased diurnal variation and an inverted U-shaped pattern in MDD, compared to a positive linear trend in controls) and tiredness (decreased diurnal variation in MDD). In the MDD group only, passive suicidality displayed a negative linear trend and self-esteem displayed a quadratic inverted U trend. MDD and control participants thus showed distinct dynamic profiles in all symptoms measured. As well as the overall severity of symptoms, intra-day dynamics appear to define the experience of MDD symptoms. Copyright © 2018 Elsevier B.V. All rights reserved.
Career Preparedness and School Achievement of Portuguese Children: Longitudinal Trend Articulations
Oliveira, Íris M.; Taveira, Maria do Céu; Porfeli, Erik J.
2017-01-01
Social Cognitive Career Theory suggests that students' preparedness for the school-to-work transition is a developmental process. Middle school children explore various careers, obtain feedback about their academic progress, and develop career self-efficacy and outcome expectations. These processes advance provisional educational/occupational goals. The literature has suggested articulations between career and academic development and how both vary across demographic characteristics, but longitudinal studies linking these processes are scarce. This study tested articulations between career preparedness and academic achievement during middle school years and employed gender and geographical location as potential moderators affecting the linkage between career and school domains. Participants included 429 children (47.8% girls) from northern (69.5%) and central Portugal (30.5%) followed across four occasions of measurement (MageWave1 = 10.23, SD = 0.50). Data was collected with school records, the Multidimensional Scales of Perceived Self-Efficacy, Career Exploratory Outcome Expectations Scale, Childhood Career Exploration Inventory and Childhood Career Development Scale. Average and orthnormalized linear, quadratic and cubic trends were computed. Pearson correlation coefficients suggested positive and statistically significant associations between career exploratory outcome expectations and academic achievement average trends. Career planning and self-efficacy expectations were negatively associated with academic achievement quadratic trends. Multiple linear regression models suggested that career exploratory outcome expectations and career planning were respectively statistically significant predictors of the average and quadratic trends of academic achievement. Gender moderated the association between the career variables and academic achievement linear trends as well as the relation of career planning and self-efficacy with academic achievement cubic trends. Additionally, the geographical location moderated the association between the average trend of career exploratory outcome expectations and academic achievement as well as tended to moderate the relation between the career variables and academic achievement quadratic trends. Future research could seek to explore the role of context in shaping the trajectories and linkages between career and academic progress with a more representative sample of participants from a broader array of geographical locations. This study advances extant literature by affirming the longitudinal relationship between the school and work domains in youth, which might sustain practices aimed at fostering students' career preparedness and academic achievement. PMID:28484413
Twenty-year trends in cardiovascular risk factors in India and influence of educational status.
Gupta, Rajeev; Guptha, Soneil; Gupta, V P; Agrawal, Aachu; Gaur, Kiran; Deedwania, Prakash C
2012-12-01
Urban middle-socioeconomic status (SES) subjects have high burden of cardiovascular risk factors in low-income countries. To determine secular trends in risk factors among this population and to correlate risks with educational status we performed epidemiological studies in India. Five cross-sectional studies were performed in middle-SES urban locations in Jaipur, India from years 1992 to 2010. Cluster sampling was performed. Subjects (men, women) aged 20-59 years evaluated were 712 (459, 253) in 1992-94, 558 (286, 272) in 1999-2001, 374 (179, 195) in 2002-03, 887 (414, 473) in 2004-05, and 530 (324, 206) in 2009-10. Data were obtained by history, anthropometry, and fasting blood glucose and lipids estimation. Response rates varied from 55 to 75%. Mean values and risk factor prevalence were determined. Secular trends were identified using quadratic and log-linear regression and chi-squared for trend. Across the studies, there was high prevalence of overweight, hypertension, and lipid abnormalities. Age- and sex-adjusted trends showed significant increases in mean body mass index (BMI), fasting glucose, total cholesterol, high-density lipoprotein (HDL) cholesterol, and triglycerides (quadratic and log-linear regression, p < 0.001). Systolic blood pressure (BP) decreased while insignificant changes were observed for waist-hip ratio and low-density lipoprotein (LDL) cholesterol. Categorical trends showed increase in overweight and decrease in smoking (p < 0.05); insignificant changes were observed in truncal obesity, hypertension, hypercholesterolaemia, and diabetes. Adjustment for educational status attenuated linear trends in BMI and total and LDL cholesterol and accentuated trends in systolic BP, glucose, and HDL cholesterol. There was significant association of an increase in education with decline in smoking and an increase in overweight (two-line regression p < 0.05). In Indian urban middle-SES subjects there is high prevalence of cardiovascular risk factors. Over a 20-year period BMI and overweight increased, smoking and systolic BP decreased, and truncal obesity, hypercholesterolaemia, and diabetes remained stable. Increasing educational status attenuated trends for systolic BP, glucose and HDL cholesterol, and BMI.
Career Preparedness and School Achievement of Portuguese Children: Longitudinal Trend Articulations.
Oliveira, Íris M; Taveira, Maria do Céu; Porfeli, Erik J
2017-01-01
Social Cognitive Career Theory suggests that students' preparedness for the school-to-work transition is a developmental process. Middle school children explore various careers, obtain feedback about their academic progress, and develop career self-efficacy and outcome expectations. These processes advance provisional educational/occupational goals. The literature has suggested articulations between career and academic development and how both vary across demographic characteristics, but longitudinal studies linking these processes are scarce. This study tested articulations between career preparedness and academic achievement during middle school years and employed gender and geographical location as potential moderators affecting the linkage between career and school domains. Participants included 429 children (47.8% girls) from northern (69.5%) and central Portugal (30.5%) followed across four occasions of measurement ( M ageWave1 = 10.23, SD = 0.50). Data was collected with school records, the Multidimensional Scales of Perceived Self-Efficacy, Career Exploratory Outcome Expectations Scale, Childhood Career Exploration Inventory and Childhood Career Development Scale. Average and orthnormalized linear, quadratic and cubic trends were computed. Pearson correlation coefficients suggested positive and statistically significant associations between career exploratory outcome expectations and academic achievement average trends. Career planning and self-efficacy expectations were negatively associated with academic achievement quadratic trends. Multiple linear regression models suggested that career exploratory outcome expectations and career planning were respectively statistically significant predictors of the average and quadratic trends of academic achievement. Gender moderated the association between the career variables and academic achievement linear trends as well as the relation of career planning and self-efficacy with academic achievement cubic trends. Additionally, the geographical location moderated the association between the average trend of career exploratory outcome expectations and academic achievement as well as tended to moderate the relation between the career variables and academic achievement quadratic trends. Future research could seek to explore the role of context in shaping the trajectories and linkages between career and academic progress with a more representative sample of participants from a broader array of geographical locations. This study advances extant literature by affirming the longitudinal relationship between the school and work domains in youth, which might sustain practices aimed at fostering students' career preparedness and academic achievement.
The influence of ENSO, PDO and PNA on secular rainfall variations in Hawai`i
NASA Astrophysics Data System (ADS)
Frazier, Abby G.; Elison Timm, Oliver; Giambelluca, Thomas W.; Diaz, Henry F.
2017-11-01
Over the last century, significant declines in rainfall across the state of Hawai`i have been observed, and it is unknown whether these declines are due to natural variations in climate, or manifestations of human-induced climate change. Here, a statistical analysis of the observed rainfall variability was applied as first step towards better understanding causes for these long-term trends. Gridded seasonal rainfall from 1920 to 2012 is used to perform an empirical orthogonal function (EOF) analysis. The leading EOF components are correlated with three indices of natural climate variations (El Niño-Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO), and Pacific North American (PNA)), and multiple linear regression (MLR) is used to model the leading components with climate indices. PNA is the dominant mode of wet season (November-April) variability, while ENSO is most significant in the dry season (May-October). To assess whether there is an anthropogenic influence on rainfall, two methods are used: a linear trend term is included in the MLR, and pattern correlation coefficients (PCC) are calculated between recent rainfall trends and future changes in rainfall projected by downscaling methods. PCC results indicate that recent observed rainfall trends in the wet season are positively correlated with future expected changes in rainfall, while dry season PCC results do not show a clear pattern. The MLR results, however, show that the trend term adds significantly to model skill only in the dry season. Overall, MLR and PCC results give weak and inconclusive evidence for detection of anthropogenic signals in the observed rainfall trends.
[Visual field progression in glaucoma: cluster analysis].
Bresson-Dumont, H; Hatton, J; Foucher, J; Fonteneau, M
2012-11-01
Visual field progression analysis is one of the key points in glaucoma monitoring, but distinction between true progression and random fluctuation is sometimes difficult. There are several different algorithms but no real consensus for detecting visual field progression. The trend analysis of global indices (MD, sLV) may miss localized deficits or be affected by media opacities. Conversely, point-by-point analysis makes progression difficult to differentiate from physiological variability, particularly when the sensitivity of a point is already low. The goal of our study was to analyse visual field progression with the EyeSuite™ Octopus Perimetry Clusters algorithm in patients with no significant changes in global indices or worsening of the analysis of pointwise linear regression. We analyzed the visual fields of 162 eyes (100 patients - 58 women, 42 men, average age 66.8 ± 10.91) with ocular hypertension or glaucoma. For inclusion, at least six reliable visual fields per eye were required, and the trend analysis (EyeSuite™ Perimetry) of visual field global indices (MD and SLV), could show no significant progression. The analysis of changes in cluster mode was then performed. In a second step, eyes with statistically significant worsening of at least one of their clusters were analyzed point-by-point with the Octopus Field Analysis (OFA). Fifty four eyes (33.33%) had a significant worsening in some clusters, while their global indices remained stable over time. In this group of patients, more advanced glaucoma was present than in stable group (MD 6.41 dB vs. 2.87); 64.82% (35/54) of those eyes in which the clusters progressed, however, had no statistically significant change in the trend analysis by pointwise linear regression. Most software algorithms for analyzing visual field progression are essentially trend analyses of global indices, or point-by-point linear regression. This study shows the potential role of analysis by clusters trend. However, for best results, it is preferable to compare the analyses of several tests in combination with morphologic exam. Copyright © 2012 Elsevier Masson SAS. All rights reserved.
NASA Astrophysics Data System (ADS)
Jhajharia, Deepak; Yadav, Brijesh K.; Maske, Sunil; Chattopadhyay, Surajit; Kar, Anil K.
2012-01-01
Trends in rainfall, rainy days and 24 h maximum rainfall are investigated using the Mann-Kendall non-parametric test at twenty-four sites of subtropical Assam located in the northeastern region of India. The trends are statistically confirmed by both the parametric and non-parametric methods and the magnitudes of significant trends are obtained through the linear regression test. In Assam, the average monsoon rainfall (rainy days) during the monsoon months of June to September is about 1606 mm (70), which accounts for about 70% (64%) of the annual rainfall (rainy days). On monthly time scales, sixteen and seventeen sites (twenty-one sites each) witnessed decreasing trends in the total rainfall (rainy days), out of which one and three trends (seven trends each) were found to be statistically significant in June and July, respectively. On the other hand, seventeen sites witnessed increasing trends in rainfall in the month of September, but none were statistically significant. In December (February), eighteen (twenty-two) sites witnessed decreasing (increasing) trends in total rainfall, out of which five (three) trends were statistically significant. For the rainy days during the months of November to January, twenty-two or more sites witnessed decreasing trends in Assam, but for nine (November), twelve (January) and eighteen (December) sites, these trends were statistically significant. These observed changes in rainfall, although most time series are not convincing as they show predominantly no significance, along with the well-reported climatic warming in monsoon and post-monsoon seasons may have implications for human health and water resources management over bio-diversity rich Northeast India.
Ding, Ming; Bhupathiraju, Shilpa N; Satija, Ambika; van Dam, Rob M; Hu, Frank B
2013-01-01
Background Considerable controversy exists regarding the association between coffee consumption and cardiovascular disease (CVD) risk. A meta-analysis was performed to assess the dose-response relationship of long-term coffee consumption with CVD risk. Methods and Results Pubmed and EMBASE were searched for prospective cohort studies of the relationship between coffee consumption and CVD risk, which included coronary heart disease, stroke, heart failure, and CVD mortality. Thirty-six studies were included with 1,279,804 participants and 36,352 CVD cases. A non-linear relationship of coffee consumption with CVD risk was identified (P for heterogeneity = 0.09, P for trend < 0.001, P for non-linearity < 0.001). Compared with the lowest category of coffee consumption (median: 0 cups/d), the relative risk of CVD was 0.95 (95% CI, 0.87 to 1.03) for the highest (median: 5 cups/d) category, 0.85 (0.80 to 0.90) for the second highest (median: 3.5 cups/d), and 0.89 (0.84 to 0.94) for the third highest category (median: 1.5 cups/d). Looking at separate outcomes, coffee consumption was non-linearly associated with both CHD (P for heterogeneity = 0.001, P for trend < 0.001, P for non-linearity < 0.001) and stroke risks (P for heterogeneity = 0.07, P for trend < 0.001, P for non-linearity< 0.001) (P for trend differences > 0.05). Conclusions A non-linear association between coffee consumption with CVD risk was observed in this meta-analysis. Moderate coffee consumption was inversely significantly associated with CVD risk, with the lowest CVD risk at 3 to 5 cups/d, and heavy coffee consumption was not associated with elevated CVD risk. PMID:24201300
Latitudinal dependence of variations in stratospheric NO2 content
NASA Astrophysics Data System (ADS)
Gruzdev, A. N.
2008-06-01
Diurnal and annual variations in the NO2 total content (TC), the effect of its decrease owing to the products of the eruption of Mt. Pinatubo, its variations during an 11-year cycle of solar activity, and its linear trends are analyzed on the basis of data obtained from the ground-based spectrometric measurements of the NO2 TC in stratospheric vertical columns over the stations of the Network for the Detection of Atmospheric Composition Change. Latitudinal dependence of the indicated variations and trends is revealed. The annual estimates of the linear trends of the NO2 TC are found to be mostly positive for the middle and low latitudes of the Southern Hemisphere and negative for the middle and low latitudes of the Northern Hemisphere. The maximum values of the positive and negative trends amount to ˜10% per ten years. In the high and polar latitudes of both hemispheres, the annual trend estimates are statistically insignificant. Seasonal estimates of the trends may differ from their annual estimates. The trends and solar-activity effect in the NO2 TC, which were estimated by using the two-dimensional model SOCRATES, as well as the analytical estimates of a zonal mean trend of the NO2 TC, on the whole, significantly differ from the estimates obtained from the measurements.
Estimating linear temporal trends from aggregated environmental monitoring data
Erickson, Richard A.; Gray, Brian R.; Eager, Eric A.
2017-01-01
Trend estimates are often used as part of environmental monitoring programs. These trends inform managers (e.g., are desired species increasing or undesired species decreasing?). Data collected from environmental monitoring programs is often aggregated (i.e., averaged), which confounds sampling and process variation. State-space models allow sampling variation and process variations to be separated. We used simulated time-series to compare linear trend estimations from three state-space models, a simple linear regression model, and an auto-regressive model. We also compared the performance of these five models to estimate trends from a long term monitoring program. We specifically estimated trends for two species of fish and four species of aquatic vegetation from the Upper Mississippi River system. We found that the simple linear regression had the best performance of all the given models because it was best able to recover parameters and had consistent numerical convergence. Conversely, the simple linear regression did the worst job estimating populations in a given year. The state-space models did not estimate trends well, but estimated population sizes best when the models converged. We found that a simple linear regression performed better than more complex autoregression and state-space models when used to analyze aggregated environmental monitoring data.
NASA Astrophysics Data System (ADS)
Pandolfi, Marco; Alastuey, Andrés; Pérez, Noemi; Reche, Cristina; Castro, Iria; Shatalov, Victor; Querol, Xavier
2016-09-01
In this work for the first time data from two twin stations (Barcelona, urban background, and Montseny, regional background), located in the northeast (NE) of Spain, were used to study the trends of the concentrations of different chemical species in PM10 and PM2.5 along with the trends of the PM10 source contributions from the positive matrix factorization (PMF) model. Eleven years of chemical data (2004-2014) were used for this study. Trends of both species concentrations and source contributions were studied using the Mann-Kendall test for linear trends and a new approach based on multi-exponential fit of the data. Despite the fact that different PM fractions (PM2.5, PM10) showed linear decreasing trends at both stations, the contributions of specific sources of pollutants and of their chemical tracers showed exponential decreasing trends. The different types of trends observed reflected the different effectiveness and/or time of implementation of the measures taken to reduce the concentrations of atmospheric pollutants. Moreover, the trends of the contributions of specific sources such as those related with industrial activities and with primary energy consumption mirrored the effect of the financial crisis in Spain from 2008. The sources that showed statistically significant downward trends at both Barcelona (BCN) and Montseny (MSY) during 2004-2014 were secondary sulfate, secondary nitrate, and V-Ni-bearing source. The contributions from these sources decreased exponentially during the considered period, indicating that the observed reductions were not gradual and consistent over time. Conversely, the trends were less steep at the end of the period compared to the beginning, thus likely indicating the attainment of a lower limit. Moreover, statistically significant decreasing trends were observed for the contributions to PM from the industrial/traffic source at MSY (mixed metallurgy and road traffic) and from the industrial (metallurgy mainly) source at BCN. These sources were clearly linked with anthropogenic activities, and the observed decreasing trends confirmed the effectiveness of pollution control measures implemented at European or regional/local levels. Conversely, at regional level, the contributions from sources mostly linked with natural processes, such as aged marine and aged organics, did not show statistically significant trends. The trends observed for the PM10 source contributions reflected the trends observed for the chemical tracers of these pollutant sources well.
Thorisdottir, Ingibjorg E; Asgeirsdottir, Bryndis B; Sigurvinsdottir, Rannveig; Allegrante, John P; Sigfusdottir, Inga D
2017-10-01
Both research and popular media reports suggest that adolescent mental health has been deteriorating across societies with advanced economies. This study sought to describe the trends in self-reported symptoms of depressed mood and anxiety among Icelandic adolescents. Data for this study come from repeated, cross-sectional, population-based school surveys of 43 482 Icelandic adolescents in 9th and 10th grade, with six waves of pooled data from 2006 to 2016. We used analysis of variance, linear regression and binomial logistic regression to examine trends in symptom scores of anxiety and depressed mood over time. Gender differences in trends of high symptoms were also tested for interactions. Linear regression analysis showed a significant linear increase over the course of the study period in mean symptoms of anxiety and depressed mood for girls only; however, symptoms of anxiety among boys decreased. The proportion of adolescents reporting high depressive symptoms increased by 1.6% for boys and 6.8% for girls; the proportion of those reporting high anxiety symptoms increased by 1.3% for boys and 8.6% for girls. Over the study period, the odds for reporting high depressive symptoms and high anxiety symptoms were significantly higher for both genders. Girls were more likely to report high symptoms of anxiety and depressed mood than boys. Self-reported symptoms of anxiety and depressed mood have increased over time among Icelandic adolescents. Our findings suggest that future research needs to look beyond mean changes and examine the trends among those adolescents who report high symptoms of emotional distress. © The Author 2017. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.
Fracture trends identified by ERTS-1 imagery in Utah and Nevada
NASA Technical Reports Server (NTRS)
Jensen, M. L. (Principal Investigator); Erickson, M. P.; Smith, M. R.
1973-01-01
The author has identified the following significant results. In the Utah-Nevada area, linear structural trends recorded on ERTS-1 imagery conform in part to previously recognized structures. In addition, the ERTS-1 imagery reveals cryptic structures not previously identified and not readily apparent in other imagery. These structures are illustrated by prominent east-west trending structures which appear to be concentrated in pre-volcanic rocks. This suggests that the structures are older than many of those with other trends which are equally prominent in volcanic and non-volcanic terrain. Since the older east-west structures may have controlled early Tertiary emplacement of magma or the ascent of mineralizing fluids, their recognition is important in minerial exploration. Soil-gas sampling and analysis for mercury content is being continued over structures, and projected trends of buried structures which appear, from studies of ERTS-1 imagery, to be favorable to mineralization. Comparison of ERTS-1 and Skylab imagery indicated that ERTS-1 imagery records more previously unrecognized linear structures than the Skylab imagery. In differentiating and identifying different rock types, the Skylab imagery appears to be more effective.
NASA Astrophysics Data System (ADS)
Kürbis, K.; Mudelsee, M.; Tetzlaff, G.; Brázdil, R.
2009-09-01
For the analysis of trends in weather extremes, we introduce a diagnostic index variable, the exceedance product, which combines intensity and frequency of extremes. We separate trends in higher moments from trends in mean or standard deviation and use bootstrap resampling to evaluate statistical significances. The application of the concept of the exceedance product to daily meteorological time series from Potsdam (1893 to 2005) and Prague-Klementinum (1775 to 2004) reveals that extremely cold winters occurred only until the mid-20th century, whereas warm winters show upward trends. These changes were significant in higher moments of the temperature distribution. In contrast, trends in summer temperature extremes (e.g., the 2003 European heatwave) can be explained by linear changes in mean or standard deviation. While precipitation at Potsdam does not show pronounced trends, dew point does exhibit a change from maximum extremes during the 1960s to minimum extremes during the 1970s.
Haider, Batool A; Olofin, Ibironke; Wang, Molin; Spiegelman, Donna; Ezzati, Majid; Fawzi, Wafaie W
2013-06-21
To summarise evidence on the associations of maternal anaemia and prenatal iron use with maternal haematological and adverse pregnancy outcomes; and to evaluate potential exposure-response relations of dose of iron, duration of use, and haemoglobin concentration in prenatal period with pregnancy outcomes. Systematic review and meta-analysis Searches of PubMed and Embase for studies published up to May 2012 and references of review articles. Randomised trials of prenatal iron use and prospective cohort studies of prenatal anaemia; cross sectional and case-control studies were excluded. 48 randomised trials (17 793 women) and 44 cohort studies (1 851 682 women) were included. Iron use increased maternal mean haemoglobin concentration by 4.59 (95% confidence interval 3.72 to 5.46) g/L compared with controls and significantly reduced the risk of anaemia (relative risk 0.50, 0.42 to 0.59), iron deficiency (0.59, 0.46 to 0.79), iron deficiency anaemia (0.40, 0.26 to 0.60), and low birth weight (0.81, 0.71 to 0.93). The effect of iron on preterm birth was not significant (relative risk 0.84, 0.68 to 1.03). Analysis of cohort studies showed a significantly higher risk of low birth weight (adjusted odds ratio 1.29, 1.09 to 1.53) and preterm birth (1.21, 1.13 to 1.30) with anaemia in the first or second trimester. Exposure-response analysis indicated that for every 10 mg increase in iron dose/day, up to 66 mg/day, the relative risk of maternal anaemia was 0.88 (0.84 to 0.92) (P for linear trend<0.001). Birth weight increased by 15.1 (6.0 to 24.2) g (P for linear trend=0.005) and risk of low birth weight decreased by 3% (relative risk 0.97, 0.95 to 0.98) for every 10 mg increase in dose/day (P for linear trend<0.001). Duration of use was not significantly associated with the outcomes after adjustment for dose. Furthermore, for each 1 g/L increase in mean haemoglobin, birth weight increased by 14.0 (6.8 to 21.8) g (P for linear trend=0.002); however, mean haemoglobin was not associated with the risk of low birth weight and preterm birth. No evidence of a significant effect on duration of gestation, small for gestational age births, and birth length was noted. Daily prenatal use of iron substantially improved birth weight in a linear dose-response fashion, probably leading to a reduction in risk of low birth weight. An improvement in prenatal mean haemoglobin concentration linearly increased birth weight.
Phillips-Howard, Penelope A.; Odhiambo, Frank O.; Hamel, Mary; Ackers, Marta; van Eijk, Anne M.; Orimba, Vincent; Hoog, Anja van’t; Beynon, Caryl; Vulule, John; Bellis, Mark A.; Slutsker, Laurence; deCock, Kevin; Breiman, Robert; Laserson, Kayla F.
2012-01-01
Background Targeted global efforts to improve survival of young adults need information on mortality trends; contributions from health and demographic surveillance system (HDSS) are required. Methods and Findings This study aimed to explore changing trends in deaths among adolescents (15–19 years) and young adults (20–24 years), using census and verbal autopsy data in rural western Kenya using a HDSS. Mid-year population estimates were used to generate all-cause mortality rates per 100,000 population by age and gender, by communicable (CD) and non-communicable disease (NCD) causes. Linear trends from 2003 to 2009 were examined. In 2003, all-cause mortality rates of adolescents and young adults were 403 and 1,613 per 100,000 population, respectively, among females; and 217 and 716 per 100,000, respectively, among males. CD mortality rates among females and males 15–24 years were 500 and 191 per 100,000 (relative risk [RR] 2.6; 95% confidence intervals [CI] 1.7–4.0; p<0.001). NCD mortality rates in same aged females and males were similar (141 and 128 per 100,000, respectively; p = 0.76). By 2009, young adult female all-cause mortality rates fell 53% (χ2 for linear trend 30.4; p<0.001) and 61.5% among adolescent females (χ2 for linear trend 11.9; p<0.001). No significant CD mortality reductions occurred among males or for NCD mortality in either gender. By 2009, all-cause, CD, and NCD mortality rates were not significantly different between males and females, and among males, injuries equalled HIV as the top cause of death. Conclusions This study found significant reductions in adolescent and young adult female mortality rates, evidencing the effects of targeted public health programmes, however, all-cause and CD mortality rates among females remain alarmingly high. These data underscore the need to strengthen programmes and target strategies to reach both males and females, and to promote NCD as well as CD initiatives to reduce the mortality burden amongst both gender. PMID:23144796
Katzmarzyk, Peter T; Broyles, Stephanie T; Champagne, Catherine M; Chaput, Jean-Philippe; Fogelholm, Mikael; Hu, Gang; Kuriyan, Rebecca; Kurpad, Anura; Lambert, Estelle V; Maia, Jose; Matsudo, Victor; Olds, Timothy; Onywera, Vincent; Sarmiento, Olga L; Standage, Martyn; Tremblay, Mark S; Tudor-Locke, Catrine; Zhao, Pei
2016-11-30
The purpose of this study was to determine the association between regular (sugar containing) and diet (artificially sweetened) soft drink consumption and obesity in children from 12 countries ranging in levels of economic and human development. The sample included 6162 children aged 9-11 years. Information on soft drink consumption was obtained using a food frequency questionnaire. Percentage body fat (%BF) was estimated by bio-electrical impedance analysis, body mass index (BMI) z -scores were computed using World Health Organization reference data, and obesity was defined as a BMI > +2 standard deviations (SD). Multi-level models were used to investigate trends in BMI z -scores, %BF and obesity across categories of soft drink consumption. Age, sex, study site, parental education and physical activity were included as covariates. There was a significant linear trend in BMI z -scores across categories of consumption of regular soft drinks in boys ( p = 0.049), but not in girls; there were no significant trends in %BF or obesity observed in either boys or girls. There was no significant linear trend across categories of diet soft drink consumption in boys, but there was a graded, positive association in girls for BMI z -score ( p = 0.0002) and %BF ( p = 0.0001). Further research is required to explore these associations using longitudinal research designs.
Katzmarzyk, Peter T.; Broyles, Stephanie T.; Champagne, Catherine M.; Chaput, Jean-Philippe; Fogelholm, Mikael; Hu, Gang; Kuriyan, Rebecca; Kurpad, Anura; Lambert, Estelle V.; Maia, Jose; Matsudo, Victor; Olds, Timothy; Onywera, Vincent; Sarmiento, Olga L.; Standage, Martyn; Tremblay, Mark S.; Tudor-Locke, Catrine; Zhao, Pei
2016-01-01
The purpose of this study was to determine the association between regular (sugar containing) and diet (artificially sweetened) soft drink consumption and obesity in children from 12 countries ranging in levels of economic and human development. The sample included 6162 children aged 9–11 years. Information on soft drink consumption was obtained using a food frequency questionnaire. Percentage body fat (%BF) was estimated by bio-electrical impedance analysis, body mass index (BMI) z-scores were computed using World Health Organization reference data, and obesity was defined as a BMI > +2 standard deviations (SD). Multi-level models were used to investigate trends in BMI z-scores, %BF and obesity across categories of soft drink consumption. Age, sex, study site, parental education and physical activity were included as covariates. There was a significant linear trend in BMI z-scores across categories of consumption of regular soft drinks in boys (p = 0.049), but not in girls; there were no significant trends in %BF or obesity observed in either boys or girls. There was no significant linear trend across categories of diet soft drink consumption in boys, but there was a graded, positive association in girls for BMI z-score (p = 0.0002) and %BF (p = 0.0001). Further research is required to explore these associations using longitudinal research designs. PMID:27916866
Landsat analysis for uranium exploration in Northeast Turkey
Lee, Keenan
1983-01-01
No uranium deposits are known in the Trabzon, Turkey region, and consequently, exploration criteria have not been defined. Nonetheless, by analogy with uranium deposits studied elsewhere, exploration guides are suggested to include dense concentrations of linear features, lineaments -- especially with northwest trend, acidic plutonic rocks, and alteration indicated by limonite. A suite of digitally processed images of a single Landsat scene served as the image base for mapping 3,376 linear features. Analysis of the linear feature data yielded two statistically significant trends, which in turn defined two sets of strong lineaments. Color composite images were used to map acidic plutonic rocks and areas of surficial limonitic materials. The Landsat interpretation yielded a map of these exploration guides that may be used to evaluate relative uranium potential. One area in particular shows a high coincidence of favorable indicators.
Bell, C.F.; Belval, D.L.; Campbell, J.P.
1996-01-01
Water-quality samples were collected at the Fall Line of five tributaries to the Chesapeake Bay in Virginia during a 6- to 7-year period. The water-quality data were used to estimate loads of nutrients and suspended solids from these tributaries to the non-tidal part of Chesapeake Bay Basin and to identify trends in water quality. Knowledge of trends in water quality is required to assess the effectiveness of nutrient manage- ment strategies in the five basins. Multivariate log-linear regression and the seasonal Kendall test were used to estimate flow-adjusted trends in constituent concentration and load. Results of multivariate log-linear regression indicated a greater number of statistically significant trends than the seasonal Kendall test; how-ever, when both methods indicated a significant trend, both agreed on the direction of the trend. Interpre- tation of the trend estimates for this report was based on results of the parametric regression method. No significant trends in total nitrogen concentration were detected at the James River monitoring station from July 1988 through June 1995, though total Kjeldahl nitrogen concen- tration decreased slightly in base-flow samples. Total phosphorus concentration decreased about 29 percent at this station during the sampling period. Most of the decrease can be attributed to reductions in point-source phosphorus loads in 1988 and 1989, especially the phosphate detergent ban of 1988. No significant trends in total suspended solids were observed at the James River monitoring station, and no trends in runoff- derived constituents were interpreted for this river. Significant decreases were detected in concentrations of total nitrogen, total Kjeldahl nitrogen, dissolved nitrite-plus-nitrate nitrogen, and total suspended solids at the Rappahannock River monitoring station between July 1988 and June 1995. A similar downward trend in total phosphorus concentration was significant at the 90-percent confidence level, but not the 95-percent confidence level. These decreases can be attributed primarily to reductions in nonpoint nutrient and sediment loads, and may have been partially caused by implementation of best management practices on agricultural and silvicultural land. Flow-adjusted trends observed at the Appomattox, Pamunkey, and Mattaponi monitoring stations were more difficult to explain than those at the James and Rappahannock stations. Total Kjeldahl nitrogen and total phosphorus increased 16 and 23 percent, respectively, at the Appomattox River monitoring station from July 1989 through June 1995. Total phosphorus concentration increased about 46 percent at the Pamunkey River monitoring station between July 1989 and June 1995. At the Mattaponi River monitoring station, decreases in dissolved nitrite-plus-nitrate nitrogen were offset by increases in total Kjeldahl nitrogen, resulting in no net change in total nitrogen concentration from October 1989 through June 1995.
Barreira, Tiago V; Harrington, Deirdre M; Katzmarzyk, Peter T
2014-01-01
To determine whether relationships exist between accelerometer-measured moderate-to-vigorous physical activity (MVPA) and other cardiovascular (CV) health metrics in a large sample. Data from the 2003-2006 National Health and Nutrition Examination Survey (NHANES) collected from January 1, 2003, through December 31, 2006, were used. Overall, 3454 nonpregnant adults 20 years or older who fasted for 6 hours or longer, with valid accelerometer data and with CV health metrics, were included in the study. Blood pressure (BP), body mass index (BMI), smoking status, diet, fasting plasma glucose level, and total cholesterol level were defined as ideal, intermediate, and poor on the basis of American Heart Association criteria. Results were weighted to account for sampling design, oversampling, and nonresponse. Significant increasing linear trends in mean daily MVPA were observed across CV health levels for BMI, BP, and fasting plasma glucose (P<.001). Those with a poor BMI and BP had significantly lower mean daily MVPA than those with intermediate and ideal BMIs and BPs (all P<.001). In addition, individuals with an intermediate fasting plasma glucose level had significantly lower mean daily MVPA than individuals at the ideal levels (P<.001). No significant linear trends were observed for cholesterol, smoking, and diet. A significant linear trend was observed for mean daily MVPA and the overall number of other CV health metrics (P<.001). Objectively measured MVPA was related to other CV health metrics in this large sample. These results support the inclusion of physical activity in the overall definition of ideal CV health. Copyright © 2014 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.
Variations of global gravity waves derived from 14 years of SABER temperature observations
NASA Astrophysics Data System (ADS)
Liu, Xiao; Yue, Jia; Xu, Jiyao; Garcia, Rolando R.; Russell, James M.; Mlynczak, Martin; Wu, Dong L.; Nakamura, Takuji
2017-06-01
The global gravity wave (GW) potential energy (PE) per unit mass is derived from SABER (Sounding of the Atmosphere using Broadband Emission Radiometry) temperature profiles over the past 14 years (2002-2015). Since the SABER data cover longer than one solar cycle, multivariate linear regression is applied to calculate the trend (means linear trend from 2002 to 2015) of global GW PE and the responses of global GW PE to solar activity, to QBO (quasi-biennial oscillation) and to ENSO (El Niño-Southern Oscillation). We find a significant positive trend of GW PE at around 50°N during July from 2002 to 2015, in agreement with ground-based radar observations at a similar latitude but from 1990 to 2010. Both the monthly and the deseasonalized trends of GW PE are significant near 50°S. Specifically, the deseasonalized trend of GW PE has a positive peak of 12-15% per decade at 40°S-50°S and below 60 km, which suggests that eddy diffusion is increasing in some places. A significant positive trend of GW PE near 50°S could be due to the strengthening of the polar stratospheric jets, as documented from Modern Era Retrospective-analysis for Research and Applications wind data. The response of GW PE to solar activity is negative in the lower and middle latitudes. The response of GW PE to QBO (as indicated by 30 hPa zonal winds over the equator) is negative in the tropical upper stratosphere and extends to higher latitudes at higher altitudes. The response of GW PE to ENSO (as indicated by the Multivariate ENSO Index) is positive in the tropical upper stratosphere.
Meijerink, Frederika J; van Vuuren, C Leontine; Wijnhoven, Hanneke A H; van Eijsden, Manon
2016-04-01
To assess seven-year time trends in energy balance-related behaviours in 14-year-old adolescents living in an urban area and to examine the influence of educational level and ethnicity on these time trends. Second grade students (mean age 13·6 years) filled in questionnaires about the energy balance-related behaviours of breakfast consumption, fruit and vegetable consumption, physical activity and screen-time behaviour from school years 2006-2007 to 2012-2013. Energy balance-related behaviours were dichotomized and logistic regression analyses were used to examine time trends in healthy energy balance-related behaviours, including interaction terms for educational level and ethnicity. Secondary schools in Amsterdam, the Netherlands. Per school year, 2185-3331 children participated. The total sample included 19 244 students of Dutch, Surinamese, Turkish and Moroccan ethnic background. A significant linear increase was found for positive screen-time behaviour (<2 h/d; OR per year=1·04; 95 % CI 1·03, 1·06). For daily vegetable consumption a non-linear negative trend was observed (school year 2012-2013 v. 2006-2007: OR=0·90; 95 % CI 0·80, 1·00). Time trends in screen time were significantly different across educational levels (P-interaction=0·002) and ethnic backgrounds (P<0·001), as were time trends in daily fruit consumption (P=0·017 and P=0·018, respectively) and, for ethnicity, trends in daily vegetable consumption (P<0·001). The increase in positive screen-time behaviour is a positive finding. However, discouraging screen time and promoting other healthy behaviours, more specifically daily fruit and vegetable consumption, remain important particularly among adolescents enrolled in pre-vocational education and of non-Dutch ethnic background.
Recent Northern Hemisphere snow cover extent trends and implications for the snow-albedo feedback
NASA Astrophysics Data System (ADS)
Déry, Stephen J.; Brown, Ross D.
2007-11-01
Monotonic trend analysis of Northern Hemisphere snow cover extent (SCE) over the period 1972-2006 with the Mann-Kendall test reveals significant declines in SCE during spring over North America and Eurasia, with lesser declines during winter and some increases in fall SCE. The weekly mean trend attains -1.28, -0.78, and -0.48 × 106 km2 (35 years)-1 over the Northern Hemisphere, North America, and Eurasia, respectively. The standardized SCE time series vary and trend coherently over Eurasia and North America, with evidence of a poleward amplification of decreasing SCE trends during spring. Multiple linear regression analyses reveal a significant dependence of the retreat of the spring continental SCE on latitude and elevation. The poleward amplification is consistent with an enhanced snow-albedo feedback over northern latitudes that acts to reinforce an initial anomaly in the cryospheric system.
Trend in frequency of extreme precipitation events over Ontario from ensembles of multiple GCMs
NASA Astrophysics Data System (ADS)
Deng, Ziwang; Qiu, Xin; Liu, Jinliang; Madras, Neal; Wang, Xiaogang; Zhu, Huaiping
2016-05-01
As one of the most important extreme weather event types, extreme precipitation events have significant impacts on human and natural environment. This study assesses the projected long term trends in frequency of occurrence of extreme precipitation events represented by heavy precipitation days, very heavy precipitation days, very wet days and extreme wet days over Ontario, based on results of 21 CMIP3 GCM runs. To achieve this goal, first, all model data are linearly interpolated onto 682 grid points (0.45° × 0.45°) in Ontario; Next, biases in model daily precipitation amount are corrected with a local intensity scaling method to make the total wet days and total wet day precipitation from each of the GCMs are consistent with that from the climate forecast system reanalysis data, and then the four indices are estimated for each of the 21 GCM runs for 1968-2000, 2046-2065 and 2081-2100. After that, with the assumption that the rate parameter of the Poisson process for the occurrence of extreme precipitation events may vary with time as climate changes, the Poisson regression model which expresses the log rate as a linear function of time is used to detect the trend in frequency of extreme events in the GCMs simulations; Finally, the trends and their uncertainty are estimated. The result shows that in the twenty-first century annual heavy precipitation days, very heavy precipitation days and very wet days and extreme wet days are likely to significantly increase over major parts of Ontario and particularly heavy precipitation days, very wet days are very likely to significantly increase in some sub-regions in eastern Ontario. However, trends of seasonal indices are not significant.
Lu, Jun; Li, Li-Ming; He, Ping-Ping; Cao, Wei-Hua; Zhan, Si-Yan; Hu, Yong-Hua
2004-06-01
To introduce the application of mixed linear model in the analysis of secular trend of blood pressure under antihypertensive treatment. A community-based postmarketing surveillance of benazepril was conducted in 1831 essential hypertensive patients (age range from 35 to 88 years) in Shanghai. Data of blood pressure was analyzed every 3 months with mixed linear model to describe the secular trend of blood pressure and changes of age-specific and gender-specific. The changing trends of systolic blood pressure (SBP) and diastolic blood pressure (DBP) were found to fit the curvilinear models. A piecewise model was fit for pulse pressure (PP), i.e., curvilinear model in the first 9 months and linear model after 9 months of taking medication. Both blood pressure and its velocity gradually slowed down. There were significant variation for the curve parameters of intercept, slope, and acceleration. Blood pressure in patients with higher initial levels was persistently declining in the 3-year-treatment. However blood pressures of patients with relatively low initial levels remained low when dropped down to some degree. Elderly patients showed high SBP but low DBP, so as with higher PP. The velocity and sizes of blood pressure reductions increased with the initial level of blood pressure. Mixed linear model is flexible and robust when applied to the analysis of longitudinal data but with missing values and can also make the maximum use of available information.
NASA Astrophysics Data System (ADS)
Moore, P.; Williams, S. D. P.
2014-12-01
Terrestrial water storage (TWS) change for 2003-2011 is estimated over Africa from GRACE gravimetric data. The signatures from change in water of the major lakes are removed by utilizing kernel functions with lake heights recovered from retracked ENVISAT satellite altimetry. In addition, the contribution of gravimetric change due to soil moisture and biomass is removed from the total GRACE signal by utilizing the GLDAS land surface model. The residual TWS time series, namely groundwater and the surface waters in rivers, wetlands, and small lakes, are investigated for trends and the seasonal cycle using linear regression. Typically, such analyses assume that the data are temporally uncorrelated but this has been shown to lead to erroneous inferences in related studies concerning the linear rate and acceleration. In this study, we utilize autocorrelation and investigate the appropriate stochastic model. The results show the proper distribution of TWS change and identify the spatial distribution of significant rates and accelerations. The effect of surface water in the major lakes is shown to contribute significantly to the trend and seasonal variation in TWS in the lake basin. Lake Volta, a managed reservoir in Ghana, is seen to have a contribution to the linear trend that is a factor of three greater than that of Lake Victoria despite having a surface area one-eighth of that of Lake Victoria. Analysis also shows the confidence levels of the deterministic trend and acceleration identifying areas where the signatures are most likely due to a physical deterministic cause and not simply stochastic variations.
Trend analysis of the long-term Swiss ozone measurements
NASA Technical Reports Server (NTRS)
Staehelin, Johannes; Bader, Juerg; Gelpke, Verena
1994-01-01
Trend analyses, assuming a linear trend which started at 1970, were performed from total ozone measurements from Arosa (Switzerland, 1926-1991). Decreases in monthly mean values were statistically significant for October through April showing decreases of about 2.0-4 percent per decade. For the period 1947-91, total ozone trends were further investigated using a multiple regression model. Temperature of a mountain peak in Switzerland (Mt. Santis), the F10.7 solar flux series, the QBO series (quasi biennial oscillation), and the southern oscillation index (SOI) were included as explanatory variables. Trends in the monthly mean values were statistically significant for December through April. The same multiple regression model was applied to investigate the ozone trends at various altitudes using the ozone balloon soundings from Payerne (1967-1989) and the Umkehr measurements from Arosa (1947-1989). The results show four different vertical trend regimes: On a relative scale changes were largest in the troposphere (increase of about 10 percent per decade). On an absolute scale the largest trends were obtained in the lower stratosphere (decrease of approximately 6 per decade at an altitude of about 18 to 22 km). No significant trends were observed at approximately 30 km, whereas stratospheric ozone decreased in the upper stratosphere.
Szilcz, Máté; Mosquera, Paola A; Sebastián, Miguel San; Gustafsson, Per E
2018-02-01
The aim was to investigate the time trends in educational, occupational, and income-related inequalities in leisure time physical inactivity in 2006, 2010, and 2014 in northern Swedish women and men. This study was based on data obtained from the repeated cross-sectional Health on Equal Terms survey of 2006, 2010, and 2014. The analytical sample consisted of 20,667 (2006), 31,787 (2010), and 21,613 (2014) individuals, aged 16-84. Logistic regressions were used to model the probability of physical inactivity given a set of explanatory variables. Slope index of inequality (SII) and relative index of inequality (RII) were used as summary measures of the social gradient in physical inactivity. The linear trend in inequalities and difference between gender and years were estimated by interaction analyses. The year 2010 displayed the highest physical inactivity inequalities for all socioeconomic position indicators, but educational and occupational inequalities decreased in 2014. However, significant positive linear trends were found in absolute and relative income inequalities. Moreover, women had significantly higher RII of education in physical inactivity in 2014 and significantly higher SII and RII of income in physical inactivity in 2010, than did men in the same years. The recent reduction in educational and occupational inequalities following the high inequalities around the time of the great recession in 2010 suggests that the current policies might be fairly effective. However, to eventually alleviate inequities in physical inactivity, the focus of the researchers and policymakers should be directed toward the widening trends of income inequalities in physical inactivity.
Trends in asthma mortality in the 0- to 4-year and 5- to 34-year age groups in Brazil
Graudenz, Gustavo Silveira; Carneiro, Dominique Piacenti; Vieira, Rodolfo de Paula
2017-01-01
ABSTRACT Objective: To provide an update on trends in asthma mortality in Brazil for two age groups: 0-4 years and 5-34 years. Methods: Data on mortality from asthma, as defined in the International Classification of Diseases, were obtained for the 1980-2014 period from the Mortality Database maintained by the Information Technology Department of the Brazilian Unified Health Care System. To analyze time trends in standardized asthma mortality rates, we conducted an ecological time-series study, using regression models for the 0- to 4-year and 5- to 34-year age groups. Results: There was a linear trend toward a decrease in asthma mortality in both age groups, whereas there was a third-order polynomial fit in the general population. Conclusions: Although asthma mortality showed a consistent, linear decrease in individuals ≤ 34 years of age, the rate of decline was greater in the 0- to 4-year age group. The 5- to 34-year group also showed a linear decline in mortality, and the rate of that decline increased after the year 2004, when treatment with inhaled corticosteroids became more widely available. The linear decrease in asthma mortality found in both age groups contrasts with the nonlinear trend observed in the general population of Brazil. The introduction of inhaled corticosteroid use through public policies to control asthma coincided with a significant decrease in asthma mortality rates in both subsets of individuals over 5 years of age. The causes of this decline in asthma-related mortality in younger age groups continue to constitute a matter of debate. PMID:28380185
Epidemiology and Trends in Incidence of Kidney Cancer in Iran.
Mirzaei, Maryam; Pournamdar, Zahra; Salehiniya, Hamid
2015-01-01
Kidney cancer has shown an increasing trend in recent decades. This study aimed to determine change in the incidence rate between 2003 and 2009 in Iran. In this study, national cancer registry data were used. Crude incidence rates were calculated per 100,000 and age-standardized incidence rates (ASRs) were computed using the direct standardization method and the world standard population. Significant trend of incidence rates was examined by the Cochran-Armitage test for linear trend. A total of 6,944 cases of kidney cancer were reported. The incidence cases increased from 595 patients in 2003 to 1,387 patients in 2009. Sex ratio (male to female) was 1.67. ASR also increased from 1.18 in 2003 to 2.52 in 2009 per 100,000, but the increasing trend was not significant. A slow increasing trend of incidence rate was observed in the study population. This may be due to an increase of risk factors. It is suggested to perform a study on risk factors for the cancer.
Spector, Logan G; Davies, Stella M; Robison, Leslie L; Hilden, Joanne M; Roesler, Michelle; Ross, Julie A
2007-01-01
Leukemias with MLL gene rearrangements predominate in infants (<1 year of age), but not in older children, and may have a distinct etiology. High birth weight, higher birth order, and prior fetal loss have, with varying consistency, been associated with infant leukemia, but no studies have reported results with respect to MLL status. Here, we report for the first time such an analysis. During 1999 to 2003, mothers of 240 incident cases (113 MLL(+), 80 MLL(-), and 47 indeterminate) and 255 random digit dialed controls completed a telephone interview. Odds ratios and 95% confidence intervals for quartile of birth weight, birth order, gestational age, maternal age at delivery, prior fetal loss, pre-pregnancy body mass index, and weight gain during pregnancy were obtained using unconditional logistic regression; P for linear trend was obtained by modeling continuous variables. There was a borderline significant linear trend of increasing birth weight with MLL(+) (P = 0.06), but not MLL(-) (P = 0.93), infant leukemia. Increasing birth order showed a significant inverse linear trend, independent of birth weight, with MLL(+) (P = 0.01), but not MLL(-) (P = 0.18), infant leukemia. Other variables of interest were not notably associated with infant leukemia regardless of MLL status. This investigation further supports the contention that molecularly defined subtypes of infant leukemia have separate etiologies.
Effects of linear trends on estimation of noise in GNSS position time-series
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dmitrieva, K.; Segall, P.; Bradley, A. M.
A thorough understanding of time-dependent noise in Global Navigation Satellite System (GNSS) position time-series is necessary for computing uncertainties in any signals found in the data. However, estimation of time-correlated noise is a challenging task and is complicated by the difficulty in separating noise from signal, the features of greatest interest in the time-series. In this study, we investigate how linear trends affect the estimation of noise in daily GNSS position time-series. We use synthetic time-series to study the relationship between linear trends and estimates of time-correlated noise for the six most commonly cited noise models. We find that themore » effects of added linear trends, or conversely de-trending, vary depending on the noise model. The commonly adopted model of random walk (RW), flicker noise (FN) and white noise (WN) is the most severely affected by de-trending, with estimates of low-amplitude RW most severely biased. FN plus WN is least affected by adding or removing trends. Non-integer power-law noise estimates are also less affected by de-trending, but are very sensitive to the addition of trend when the spectral index is less than one. We derive an analytical relationship between linear trends and the estimated RW variance for the special case of pure RW noise. Finally, overall, we find that to ascertain the correct noise model for GNSS position time-series and to estimate the correct noise parameters, it is important to have independent constraints on the actual trends in the data.« less
Effects of linear trends on estimation of noise in GNSS position time-series
NASA Astrophysics Data System (ADS)
Dmitrieva, K.; Segall, P.; Bradley, A. M.
2017-01-01
A thorough understanding of time-dependent noise in Global Navigation Satellite System (GNSS) position time-series is necessary for computing uncertainties in any signals found in the data. However, estimation of time-correlated noise is a challenging task and is complicated by the difficulty in separating noise from signal, the features of greatest interest in the time-series. In this paper, we investigate how linear trends affect the estimation of noise in daily GNSS position time-series. We use synthetic time-series to study the relationship between linear trends and estimates of time-correlated noise for the six most commonly cited noise models. We find that the effects of added linear trends, or conversely de-trending, vary depending on the noise model. The commonly adopted model of random walk (RW), flicker noise (FN) and white noise (WN) is the most severely affected by de-trending, with estimates of low-amplitude RW most severely biased. FN plus WN is least affected by adding or removing trends. Non-integer power-law noise estimates are also less affected by de-trending, but are very sensitive to the addition of trend when the spectral index is less than one. We derive an analytical relationship between linear trends and the estimated RW variance for the special case of pure RW noise. Overall, we find that to ascertain the correct noise model for GNSS position time-series and to estimate the correct noise parameters, it is important to have independent constraints on the actual trends in the data.
Effects of linear trends on estimation of noise in GNSS position time-series
Dmitrieva, K.; Segall, P.; Bradley, A. M.
2016-10-20
A thorough understanding of time-dependent noise in Global Navigation Satellite System (GNSS) position time-series is necessary for computing uncertainties in any signals found in the data. However, estimation of time-correlated noise is a challenging task and is complicated by the difficulty in separating noise from signal, the features of greatest interest in the time-series. In this study, we investigate how linear trends affect the estimation of noise in daily GNSS position time-series. We use synthetic time-series to study the relationship between linear trends and estimates of time-correlated noise for the six most commonly cited noise models. We find that themore » effects of added linear trends, or conversely de-trending, vary depending on the noise model. The commonly adopted model of random walk (RW), flicker noise (FN) and white noise (WN) is the most severely affected by de-trending, with estimates of low-amplitude RW most severely biased. FN plus WN is least affected by adding or removing trends. Non-integer power-law noise estimates are also less affected by de-trending, but are very sensitive to the addition of trend when the spectral index is less than one. We derive an analytical relationship between linear trends and the estimated RW variance for the special case of pure RW noise. Finally, overall, we find that to ascertain the correct noise model for GNSS position time-series and to estimate the correct noise parameters, it is important to have independent constraints on the actual trends in the data.« less
Associations between dietary intake of choline and betaine and lung cancer risk.
Ying, Jun; Rahbar, Mohammad H; Hallman, D Michael; Hernandez, Ladia M; Spitz, Margret R; Forman, Michele R; Gorlova, Olga Y
2013-01-01
Evidence from human and animal research indicates that choline metabolic pathways may be activated during a variety of diseases, including cancer. We report results of a case-control study of 2821 lung cancer cases and 2923 controls that assessed associations of choline and betaine dietary intakes with lung cancer. Using multivariable logistic regression analyses, we report a significant association between higher betaine intake and lower lung cancer risk that varied by smoking status. Specifically, no significant association was observed between betaine intake and lung cancer among never-smokers. However, higher betaine intake was significantly associated with reduced lung cancer risk among smokers, and the protective effect was more evident among current than former smokers: for former and current smokers, the ORs (95% CI) of lung cancer for individuals with highest as compared to lowest quartiles of intake were 0.70(0.55-0.88) and 0.51(0.39-0.66) respectively. Significant linear trend of higher betaine intake and lower lung cancer risk was observed among both former (p(trend) = 0.002) and current (p(trend)<0.0001) smokers. A similar protective effect was also observed with choline intake both in overall analysis as well as among current smokers, with p-values for chi-square tests being 0.001 and 0.004 respectively, but the effect was less evident, as no linear trend was observed. Our results suggest that choline and betaine intake, especially higher betaine intake, may be protective against lung cancer through mitigating the adverse effect of smoking.
Health Disparities Grants Funded by National Institute on Aging: Trends Between 2000 and 2010
Kim, Giyeon; DeCoster, Jamie; Huang, Chao-Hui; Parmelee, Patricia
2012-01-01
Purpose of the Study: The present study examined the characteristics of health disparities grants funded by National Institute on Aging (NIA) from 2000 to 2010. Objectives were (a) to examine longitudinal trends in health disparities–related grants funded by NIA and (b) to identify moderators of these trends. Design and Methods: Our primary data source was the National Institutes of Health Research Portfolio Online Reporting Tools Expenditures and Results (RePORTER) system. The RePORTER data were merged with data from the Carnegie Classification of Institutions of Higher Education. General linear models were used to examine the longitudinal trends and how these trends were associated with type of grant and institutional characteristics. Results: NIA funded 825 grants on health disparities between 2000 and 2010, expending approximately 330 million dollars. There was an overall linear increase over time in both the total number of grants and amount of funding, with an outlying spike during 2009. These trends were significantly influenced by several moderators including funding mechanism and type of institution. Implications: The findings highlight NIA’s current efforts to fund health disparities grants to reduce disparities among older adults. Gerontology researchers may find this information very useful for their future grant submissions. PMID:22454392
Climate change and the detection of trends in annual runoff
McCabe, G.J.; Wolock, D.M.
1997-01-01
This study examines the statistical likelihood of detecting a trend in annual runoff given an assumed change in mean annual runoff, the underlying year-to-year variability in runoff, and serial correlation of annual runoff. Means, standard deviations, and lag-1 serial correlations of annual runoff were computed for 585 stream gages in the conterminous United States, and these statistics were used to compute the probability of detecting a prescribed trend in annual runoff. Assuming a linear 20% change in mean annual runoff over a 100 yr period and a significance level of 95%, the average probability of detecting a significant trend was 28% among the 585 stream gages. The largest probability of detecting a trend was in the northwestern U.S., the Great Lakes region, the northeastern U.S., the Appalachian Mountains, and parts of the northern Rocky Mountains. The smallest probability of trend detection was in the central and southwestern U.S., and in Florida. Low probabilities of trend detection were associated with low ratios of mean annual runoff to the standard deviation of annual runoff and with high lag-1 serial correlation in the data.
An operational definition of a statistically meaningful trend.
Bryhn, Andreas C; Dimberg, Peter H
2011-04-28
Linear trend analysis of time series is standard procedure in many scientific disciplines. If the number of data is large, a trend may be statistically significant even if data are scattered far from the trend line. This study introduces and tests a quality criterion for time trends referred to as statistical meaningfulness, which is a stricter quality criterion for trends than high statistical significance. The time series is divided into intervals and interval mean values are calculated. Thereafter, r(2) and p values are calculated from regressions concerning time and interval mean values. If r(2) ≥ 0.65 at p ≤ 0.05 in any of these regressions, then the trend is regarded as statistically meaningful. Out of ten investigated time series from different scientific disciplines, five displayed statistically meaningful trends. A Microsoft Excel application (add-in) was developed which can perform statistical meaningfulness tests and which may increase the operationality of the test. The presented method for distinguishing statistically meaningful trends should be reasonably uncomplicated for researchers with basic statistics skills and may thus be useful for determining which trends are worth analysing further, for instance with respect to causal factors. The method can also be used for determining which segments of a time trend may be particularly worthwhile to focus on.
Trends in hydrological extremes in the Senegal and the Niger Rivers
NASA Astrophysics Data System (ADS)
Wilcox, C.; Bodian, A.; Vischel, T.; Panthou, G.; Quantin, G.
2017-12-01
In recent years, West Africa has witnessed several floods of unprecedented magnitude. Although the evolution of hydrological extremes has been evaluated in the region to some extent, results lack regional coverage, significance levels, uncertainty estimations, model selection criteria, or a combination of the above. In this study, Generalized Extreme Value (GEV) distributions with and without various non-stationary temporal covariates are applied to annual maxima of daily discharge (AMAX) data sets in the Sudano-Guinean part of the Senegal River basin and in the Sahelian part of the Niger River basin. The data ranges from the 1950s to the 2010s. The two models of best fit most often selected (with an alpha=0.05 certainty level) were 1) a double-linear model for the central tendency parameter (μ) with stationary dispersion (σ) and 2) a double-linear model for both parameters. Change points are relatively consistent for the Senegal basin, with stations switching from a decreasing streamflow trend to an increasing streamflow trend in the early 1980s. In the Niger basin the trend in μ was generally positive with an increase in slope after the change point, but the change point location was less consistent. The study clearly demonstrates the significant trends in extreme discharge values in West Africa over the past six decades. Moreover, it proposes a clear methodology for comparing GEV models and selecting the best for use. The return levels generated from the chosen models can be applied to river basin management and hydraulic works sizing. The results provide a first evaluation of non-stationarity in extreme hydrological values in West Africa that is accompanied by significance levels, uncertainties, and non-stationary return level estimations .
Structural and lithologic study of northern California Coast Range and Sacramento Valley, California
NASA Technical Reports Server (NTRS)
Rich, E. I. (Principal Investigator); Steele, W. C.
1973-01-01
The author has identified the following significant results. Photgeologic examination of repetitive multispectral ERTS-1 imagery of Northern California has disclosed several systems of linear features which may be important for the interpretation of the structural history of California. They are separated from an orthogonal system of linears in the Klamath Mts. by a set of discontinuous southeast-trending linear features (the Mendocino system) which is traceable from the Pacific Coast, at Cape Mendocino, into the eastern foothills of the Sierra Nevada. Within the Sierra Nevada, the Mendocino system separates the north-trending Sierran system from a set of linears characteristic of the Modoc Plateau. With minor exception, little overlap exists among the systems which suggests a decipherable chronology and evolutionary history for the region. The San Andres system of linears appears to truncate or co-exist with most of the other systems in the northern Coast Ranges. The Mendocino system truncates the Klamath, Sierran, and Modoc systems. The Sierran system may represent fundamental and long-persisting pre-late Paleozoic zones of crustal weakness which have been reactivated from time to time. The Mendocino system was possibly developed in early Mesozoic and is important to the structural framework of Northern California.
Secular trends in salt and soy sauce intake among Chinese adults, 1997-2011.
Yu, Lianlong; Li, Suyun; Zhao, Jinshan; Zhang, Junli; Wang, Liansen; Wang, Kebo
2018-03-01
Salt and soy sauce are the main ways of sodium intake in Chinese dietary. In this study, we used the data of the China Health and Nutrition Surveys to describe the secular trends of salt and soy sauce intake among Chinese adults from 1997 to 2011. Trends were tested by multiple linear regression models. During the past 14 years, the consumption of sodium, salt and soy sauce intake values decreased significantly across the six study periods (p < .0001) among both men and women. Averaged salt values decreased by 4.9 g/d in men and 4.1 g/d in women. Mean soy sauce intake values decreased by 9.0 g/d among men and 7.3 g/d among women. Similar significant trends were observed in all age groups, activity levels and regions (p < .0001).
Statistical significance of seasonal warming/cooling trends
NASA Astrophysics Data System (ADS)
Ludescher, Josef; Bunde, Armin; Schellnhuber, Hans Joachim
2017-04-01
The question whether a seasonal climate trend (e.g., the increase of summer temperatures in Antarctica in the last decades) is of anthropogenic or natural origin is of great importance for mitigation and adaption measures alike. The conventional significance analysis assumes that (i) the seasonal climate trends can be quantified by linear regression, (ii) the different seasonal records can be treated as independent records, and (iii) the persistence in each of these seasonal records can be characterized by short-term memory described by an autoregressive process of first order. Here we show that assumption ii is not valid, due to strong intraannual correlations by which different seasons are correlated. We also show that, even in the absence of correlations, for Gaussian white noise, the conventional analysis leads to a strong overestimation of the significance of the seasonal trends, because multiple testing has not been taken into account. In addition, when the data exhibit long-term memory (which is the case in most climate records), assumption iii leads to a further overestimation of the trend significance. Combining Monte Carlo simulations with the Holm-Bonferroni method, we demonstrate how to obtain reliable estimates of the significance of the seasonal climate trends in long-term correlated records. For an illustration, we apply our method to representative temperature records from West Antarctica, which is one of the fastest-warming places on Earth and belongs to the crucial tipping elements in the Earth system.
Ikeda, Hiroki; Kubo, Tomohide; Sasaki, Takeshi; Liu, Xinxin; Matsuo, Tomoaki; So, Rina; Matsumoto, Shun; Yamauchi, Takashi; Takahashi, Masaya
2018-05-25
This study aimed to describe the sleep quantity, sleep quality, and daily rest periods (DRPs) of Japanese permanent daytime workers. Information about the usual DRP, sleep quantity, and sleep quality (Japanese version of the Pittsburgh Sleep Quality Index: PSQI-J) of 3,867 permanent daytime workers in Japan was gathered through an Internet-based survey. This information was analyzed and divided into the following eight DRP groups: <10, 10, 11, 12, 13, 14, 15, and ≥16 h. The sleep durations for workers in the <10, 10, 11, 12, 13, 14, 15, and ≥16 h DRP groups were found to be 5.3, 5.9, 6.1, 6.3, 6.5, 6.7, 6.7, and 6.9 h, respectively. The trend analysis revealed a significant linear trend as the shorter the DRP, the shorter was the sleep duration. The PSQI-J scores for the <10, 10, 11, 12, 13, 14, 15, and ≥16 h DRP groups were 7.1, 6.7, 6.7, 6.3, 6.0 (5.999), 5.6, 5.2, and 5.2, respectively. The trend analysis revealed a significant linear trend as the shorter the DRP, the lower was the sleep quality. This study described sleep quantity, sleep quality, and DRP in Japanese daytime workers. It was found that a shorter DRP was associated with poorer sleep quantity as well as quality.
Cohen, Ted; Jenkins, Helen E.; Lu, Chunling; McLaughlin, Megan; Floyd, Katherine; Zignol, Matteo
2015-01-01
SUMMARY Background Multidrug resistant tuberculosis (MDR-TB) poses serious challenges for tuberculosis control in many settings, but trends of MDR-TB have been difficult to measure. Methods We analyzed surveillance and population-representative survey data collected worldwide by the World Health Organization between 1993 and 2012. We examined setting-specific patterns associated with linear trends in the estimated per capita rate of MDR-TB among new notified TB cases to generate hypotheses about factors associated with trends in the transmission of highly drug resistant tuberculosis. Results 59 countries and 39 sub-national settings had at least three years of data, but less than 10% of the population in the WHO-designated 27-high MDR-TB burden settings were in areas with sufficient data to track trends. Among settings in which the majority of MDR-TB was autochthonous, we found 10 settings with statistically significant linear trends in per capita rates of MDR-TB among new notified TB cases. Five of these settings had declining trends (Estonia, Latvia, Macao, Hong Kong, and Portugal) ranging from decreases of 3-14% annually, while five had increasing trends (four individual oblasts of the Russian Federation and Botswana) ranging from 14-20% annually. In unadjusted analysis, better surveillance indicators and higher GDP per capita were associated with declining MDR-TB, while a higher existing absolute burden of MDR-TB was associated with an increasing trend. Conclusions Only a small fraction of countries in which the burden of MDR-TB is concentrated currently have sufficient surveillance data to estimate trends in drug-resistant TB. Where trend analysis was possible, smaller absolute burdens of MDR-TB and more robust surveillance systems were associated with declining per capita rates of MDR-TB among new notified cases. PMID:25458783
Hu, Yang; Chiu, Yu Han; Hauser, Russ; Chavarro, Jorge; Sun, Qi
2016-01-01
Pesticide residues in fruits and vegetables are among the primary sources of pesticide exposure through diet, but the lack of adequate measurements hinder the research on health effects of pesticide residues. Pesticide Residue Burden Score (PRBS) for estimating overall dietary pesticide intake, organochlorine pesticide score (OC-PRBS) and organophosphate pesticide score (OP-PRBS) for estimating organochlorine and organophosphate pesticides-specific intake, respectively, were derived using U.S. Department of Agriculture Pesticide Data Program data and National Health and Nutrition Examination Survey (NHANES) food frequency questionnaire data. We evaluated the performance of these scores by validating the scores against pesticide metabolites measured in urine or serum among 3,679 participants in NHANES using generalized linear regression. The PRBS was positively associated with a score summarizing the ranks of all pesticide metabolites in a linear fashion (p for linear trend <0.001). Furthermore, individuals in the top quintile of this score had urinary pesticide metabolite levels 13.0% (95% CI 8.3%-17.7%) higher than individuals in the lowest quintile. Similarly, we observed significant associations of the OC-PRBS and OP-PRBS with the levels of lipid-adjusted total serum organochlorine pesticides and urinary creatinine-adjusted organophosphate pesticides, respectively. The relative difference (RD) in average pesticide metabolite rank between extreme quintiles was 17.8% (95% CI: 11.1%-24.4%, p for trend <0.001) for the OP-PRBS, whereas the RD was marginally significant at 7.0% (95% CI: -0.5%-14.4%, p for trend 0.07) for the OC-PRBS. The PRBS and OP-PRBS had similar performance when they were derived from fruits and vegetables with high vs. low pesticide residues, respectively (p for trend <0.001 for all associations). The OP-PRBS was associated with all measured organophosphate pesticides, whereas the positive association between OC-PRBS and averaged measured organochlorine pesticide residue rank was primarily driven by hexachlorobenzene. OC-PRBS had better performance when derived from more contaminated fruits and vegetables (p for trend 0.07) than from less contaminated Fruits and vegetables (p for trend 0.63), although neither of the associations achieved statistical significance. The PRBS and the class-specific scores for two major types of pesticides were significantly associated with pesticide biomarkers. These scores can reasonably rank study participants by their pesticide residue exposures from fruits and vegetables in large-scale environmental epidemiological studies. PMID:27128714
Hu, Yang; Chiu, Yu-Han; Hauser, Russ; Chavarro, Jorge; Sun, Qi
2016-01-01
Pesticide residues in fruits and vegetables are among the primary sources of pesticide exposure through diet, but the lack of adequate measurements hinder the research on health effects of pesticide residues. Pesticide Residue Burden Score (PRBS) for estimating overall dietary pesticide intake, organochlorine pesticide score (OC-PRBS) and organophosphate pesticide score (OP-PRBS) for estimating organochlorine and organophosphate pesticides-specific intake, respectively, were derived using U.S. Department of Agriculture Pesticide Data Program data and National Health and Nutrition Examination Survey (NHANES) food frequency questionnaire data. We evaluated the performance of these scores by validating the scores against pesticide metabolites measured in urine or serum among 3,679 participants in NHANES using generalized linear regression. The PRBS was positively associated with a score summarizing the ranks of all pesticide metabolites in a linear fashion (p for linear trend <0.001). Furthermore, individuals in the top quintile of this score had urinary pesticide metabolite levels 13.0% (95% CI 8.3%-17.7%) higher than individuals in the lowest quintile. Similarly, we observed significant associations of the OC-PRBS and OP-PRBS with the levels of lipid-adjusted total serum organochlorine pesticides and urinary creatinine-adjusted organophosphate pesticides, respectively. The relative difference (RD) in average pesticide metabolite rank between extreme quintiles was 17.8% (95% CI: 11.1%-24.4%, p for trend <0.001) for the OP-PRBS, whereas the RD was marginally significant at 7.0% (95% CI: -0.5%-14.4%, p for trend 0.07) for the OC-PRBS. The PRBS and OP-PRBS had similar performance when they were derived from fruits and vegetables with high vs. low pesticide residues, respectively (p for trend <0.001 for all associations). The OP-PRBS was associated with all measured organophosphate pesticides, whereas the positive association between OC-PRBS and averaged measured organochlorine pesticide residue rank was primarily driven by hexachlorobenzene. OC-PRBS had better performance when derived from more contaminated fruits and vegetables (p for trend 0.07) than from less contaminated Fruits and vegetables (p for trend 0.63), although neither of the associations achieved statistical significance. The PRBS and the class-specific scores for two major types of pesticides were significantly associated with pesticide biomarkers. These scores can reasonably rank study participants by their pesticide residue exposures from fruits and vegetables in large-scale environmental epidemiological studies. Copyright © 2016 Elsevier Ltd. All rights reserved.
Influenza forecasting with Google Flu Trends.
Dugas, Andrea Freyer; Jalalpour, Mehdi; Gel, Yulia; Levin, Scott; Torcaso, Fred; Igusa, Takeru; Rothman, Richard E
2013-01-01
We developed a practical influenza forecast model based on real-time, geographically focused, and easy to access data, designed to provide individual medical centers with advanced warning of the expected number of influenza cases, thus allowing for sufficient time to implement interventions. Secondly, we evaluated the effects of incorporating a real-time influenza surveillance system, Google Flu Trends, and meteorological and temporal information on forecast accuracy. Forecast models designed to predict one week in advance were developed from weekly counts of confirmed influenza cases over seven seasons (2004-2011) divided into seven training and out-of-sample verification sets. Forecasting procedures using classical Box-Jenkins, generalized linear models (GLM), and generalized linear autoregressive moving average (GARMA) methods were employed to develop the final model and assess the relative contribution of external variables such as, Google Flu Trends, meteorological data, and temporal information. A GARMA(3,0) forecast model with Negative Binomial distribution integrating Google Flu Trends information provided the most accurate influenza case predictions. The model, on the average, predicts weekly influenza cases during 7 out-of-sample outbreaks within 7 cases for 83% of estimates. Google Flu Trend data was the only source of external information to provide statistically significant forecast improvements over the base model in four of the seven out-of-sample verification sets. Overall, the p-value of adding this external information to the model is 0.0005. The other exogenous variables did not yield a statistically significant improvement in any of the verification sets. Integer-valued autoregression of influenza cases provides a strong base forecast model, which is enhanced by the addition of Google Flu Trends confirming the predictive capabilities of search query based syndromic surveillance. This accessible and flexible forecast model can be used by individual medical centers to provide advanced warning of future influenza cases.
NASA Astrophysics Data System (ADS)
Pleijel, Håkan; Grundström, Maria; Karlsson, Gunilla Pihl; Karlsson, Per Erik; Chen, Deliang
2016-02-01
Annual anomalies in air pollutant concentrations, and deposition (bulk and throughfall) of sulphate, nitrate and ammonium, in the Gothenburg region, south-west Sweden, were correlated with optimized linear combinations of the yearly frequency of Lamb Weather Types (LWTs) to determine the extent to which the year-to-year variation in pollution exposure can be partly explained by weather related variability. Air concentrations of urban NO2, CO, PM10, as well as O3 at both an urban and a rural monitoring site, and the deposition of sulphate, nitrate and ammonium for the period 1997-2010 were included in the analysis. Linear detrending of the time series was performed to estimate trend-independent anomalies. These estimated anomalies were subtracted from observed annual values. Then the statistical significance of temporal trends with and without LWT adjustment was tested. For the pollutants studied, the annual anomaly was well correlated with the annual LWT combination (R2 in the range 0.52-0.90). Some negative (annual average [NO2], ammonia bulk deposition) or positive (average urban [O3]) temporal trends became statistically significant (p < 0.05) when the LWT adjustment was applied. In all the cases but one (NH4 throughfall, for which no temporal trend existed) the significance of temporal trends became stronger with LWT adjustment. For nitrate and ammonium, the LWT based adjustment explained a larger fraction of the inter-annual variation for bulk deposition than for throughfall. This is probably linked to the longer time scale of canopy related dry deposition processes influencing throughfall being explained to a lesser extent by LWTs than the meteorological factors controlling bulk deposition. The proposed novel methodology can be used by authorities responsible for air pollution management, and by researchers studying temporal trends in pollution, to evaluate e.g. the relative importance of changes in emissions and weather variability in annual air pollution exposure.
Trends in social security benefits for oral and oropharyngeal cancer from 2006 to 2013 in Brazil.
Bomfim, Rafael Aiello; Cascaes, Andreia Morales
2018-01-01
to analyze the trends in the concession of social security sick pay for oral and oropharyngeal cancer, from 2006 to 2013, in Brazil. time series study using data of workers insured by the Brazilian National Institute of Social Security (INSS); Prais-Winsten generalized linear regressions were used to calculate the annual percentage change (APC). social security benefits for oral and oropharyngeal cancer presented significant increase (APC=9.0%; 95%CI 1.4; 17.4); benefits for other parts of the mouth, nasopharynx, oropharynx, floor of mouth and palate have also shown significant increase; the areas of trade (5.5%) and manufacturing (5.2%) were the most prevalent activities; there was a high proportion of fields in blank in the information systems (average of 72.9%). trends in occupational benefits for oral and oropharyngeal cancer showed significant increase.
Extent of Atypical Hyperplasia Stratifies Breast Cancer Risk in Two Independent Cohorts of Women
Degnim, Amy C.; Dupont, William D.; Radisky, Derek C.; Vierkant, Robert A.; Frank, Ryan D.; Frost, Marlene H.; Winham, Stacey J.; Sanders, Melinda E.; Smith, Jeffrey R.; Page, David L.; Hoskin, Tanya L.; Vachon, Celine M.; Ghosh, Karthik; Hieken, Tina J.; Denison, Lori A.; Carter, Jodi M.; Hartmann, Lynn C.; Visscher, Daniel W.
2016-01-01
Background Women with atypical hyperplasia (AH) on breast biopsy have a substantially increased risk of breast cancer (BC). Here we report BC risk with AH extent and subtype in two separate cohorts. Methods All samples containing AH were included from two cohorts of benign breast disease, Mayo Clinic and Nashville. Histology review quantified the number of foci of atypical ductal hyperplasia (ADH) and atypical lobular hyperplasia (ALH). BC risk was stratified for number of AH foci within AH subtypes. Results The study included 708 Mayo and 466 Nashville AH subjects. In the Mayo Cohort, increasing foci of AH was associated with a significant increase in risk of BC, both for ADH (RR’s of 2.61, 5.21, and 6.36 for 1, 2, and 3+ foci, p=0.006 for linear trend) and for ALH (RR’s of 2.56, 3.50, and 6.79 for 1, 2, and 3+ foci, p=0.001 for linear trend). In the Nashville Cohort, RR’s of BC for ADH were 2.70, 5.17, and 15.06 for 1, 2, and 3+ foci respectively (p<0.001 for linear trend); for ALH, RR’s also increased but not significantly (2.61, 3.48, and 4.02, p=0.148). Combining both Mayo and Nashville samples, risk increased significantly for 1, 2, and 3+ foci: RR’s of 2.65, 5.19, and 8.94 for ADH (p<0.001), and 2.58, 3.49, and 4.97 for ALH (p=0.001). Conclusions In two independent cohort studies of benign breast disease, extent of atypia stratifies long-term breast cancer risk for ADH and ALH. PMID:27352219
Economic preferences and fast food consumption in US adults: Insights from behavioral economics.
Shuval, Kerem; Stoklosa, Michal; Pachucki, Mark C; Yaroch, Amy L; Drope, Jeffrey; Harding, Matthew
2016-12-01
To examine the relationship between economic time preferences and frequency of fast food and full-service restaurant consumption among U.S. adults. Participants included 5871U.S. adults who responded to a survey conducted in 2011 pertaining to the lifestyle behaviors of families and the social context of these behaviors. The primary independent variable was a measure of time preferences, an intertemporal choice assessing delay discounting. This was elicited via responses to preferences for an immediate dollar amount or a larger sum in 30 (30-day time horizon) or 60days (60-day time horizon). Outcomes were the frequency of fast food and full-service restaurant consumption. Ordered logistic regression was performed to examine the relationship between time preferences and food consumption while adjusting for covariates (e.g. socio-demographics). Multivariable analysis revealed that higher future time preferences were significantly related to less frequent fast food intake for both the 30- and 60-day time horizon variables (P for linear trend <0.05; both). Notably, participants with the highest future time preference were significantly less likely to consume fast food than those with very low future time preferences (30-day: OR=0.74, 95%CI: 0.62-0.89; and 60-day: OR=0.86, 95%CI: 0.74-1.00). In comparison, higher future time preferences were not significantly associated with full-service restaurant intake (30-day: p for linear trend=0.73; 60-day: p for linear trend=0.83). Higher future time preferences were related to a lower frequency of fast food consumption. Utilizing concepts from behavioral economics (e.g. pre-commitment contracts) to facilitate more healthful eating is warranted using experimental studies. Copyright © 2016 Elsevier Inc. All rights reserved.
Metabolites as novel biomarkers for childhood obesity-related traits in Mexican-American children.
Farook, V S; Reddivari, L; Chittoor, G; Puppala, S; Arya, R; Fowler, S P; Hunt, K J; Curran, J E; Comuzzie, A G; Lehman, D M; Jenkinson, C P; Lynch, J L; DeFronzo, R A; Blangero, J; Hale, D E; Duggirala, R; Vanamala, J
2015-08-01
Although newer approaches have identified several metabolites associated with obesity, there is paucity of such information in paediatric populations, especially among Mexican-Americans (MAs) who are at high risk of obesity. Therefore, we performed a global serum metabolite screening in MA children to identify biomarkers of childhood obesity. We selected 15 normal-weight, 13 overweight and 14 obese MA children (6-17 years) and performed global serum metabolite screening using ultra-performance liquid chromatography/quadruple orthogonal acceleration time of flight tandem micro mass spectrometer. Metabolite values were analysed to assess mean differences among groups using one-way analysis of variance, to test for linear trend across groups and to examine Pearson's correlations between them and seven cardiometabolic traits (CMTs): body mass index, waist circumference, systolic blood pressure, diastolic blood pressure, homeostasis model of assessment-insulin resistance, triglycerides and high-density lipoprotein cholesterol. We identified 14 metabolites exhibiting differences between groups as well as linear trend across groups with nominal statistical significance. After adjustment for multiple testing, mean differences and linear trends across groups remained significant (P < 5.9 × 10(-5) ) for L-thyronine, bradykinin and naringenin. Of the examined metabolite-CMT trait pairs, all metabolites except for 2-methylbutyroylcarnitine were nominally associated with two or more CMTs, some exhibiting significance even after accounting for multiple testing (P < 3.6 × 10(-3) ). To our knowledge, this study - albeit pilot in nature - is the first study to identify these metabolites as novel biomarkers of childhood obesity and its correlates. These findings signify the need for future systematic investigations of metabolic pathways underlying childhood obesity. © 2014 World Obesity.
Gender disparities in prosthodontics: authorship and leadership, 13 years of observation.
Kongkiatkamon, Suchada; Yuan, Judy Chia-Chun; Lee, Damian J; Knoernschild, Kent L; Campbell, Stephen D; Sukotjo, Cortino
2010-10-01
The purpose of this study was to examine gender disparities in prosthodontics by reviewing the trend of female authorship in prosthodontic journals and exploring the role of female leadership in prosthodontic organizations and Advanced Education in Prosthodontic (AEP) programs. Three journals representing the prosthodontic specialty were selected to analyze the percentage of female dentist first and last (senior) authors for the years 1995, 2000, 2005, and 2008. Article inclusion criteria were restricted to the first or last authors who held at least a DMD/DDS/BDS degree and were from U.S. institutions. Data on female leadership in prosthodontic organizations and advanced education programs were collected, and the trends were studied. Descriptive statistics were used to analyze the data. A linear regression analysis was performed to investigate the proportion of female authorship compared to male in the dental literature. A Fisher's Exact Test was performed to contrast differences of female first and last authorship in the selected journals between years 1995 and 2008. Overall, there was no statistically significant linear increase in the proportion of either first or last female authorship compared to male authorship over time. With respect to each journal, the linear regression analysis showed that the increase of first female authorship was statistically significant (p= 0.016) compared to male authorship only in the Journal of Prosthetic Dentistry. The percentage of female presidents of prosthodontic organizations has been very limited. A similar trend was also observed in AEP program director positions. Over the past 13 years, female dentists' participation in prosthodontics literature authorship has not increased significantly in the United States. Furthermore, female involvement in prosthodontics leadership has been limited over the past decades. © 2010 by The American College of Prosthodontists.
NASA Astrophysics Data System (ADS)
Patra, Anindita; Bhaskaran, Prasad K.; Jose, Felix
2018-06-01
A zonal dipole in the observed trends of wind speed and significant wave height over the Head Bay of Bengal region was recently reported in the literature attributed due to the variations in sea level pressure (SLP). The SLP in turn is governed by prevailing atmospheric conditions such as local temperature, humidity, rainfall, atmospheric pressure, wind field distribution, formation of tropical cyclones, etc. The present study attempts to investigate the inter-annual variability of atmospheric parameters and its role on the observed zonal dipole trend in sea level pressure, surface wind speed and significant wave height. It reports on the aspects related to linear trend as well as its spatial variability for several atmospheric parameters: air temperature, geopotential height, omega (vertical velocity), and zonal wind, over the head Bay of Bengal, by analyzing National Centers for Environmental Prediction (NCEP) Reanalysis 2 dataset covering a period of 38 years (1979-2016). Significant warming from sea level to 200 mb pressure level and thereafter cooling above has been noticed during all the seasons. Warming within the troposphere exhibits spatial difference between eastern and western side of the domain. This led to fall in lower tropospheric geopotential height and its east-west variability, exhibiting a zonal dipole pattern across the Head Bay. In the upper troposphere, uplift in geopotential height was found as a result of cooling in higher levels (10-100 mb). Variability in omega also substantiated the observed variations in geopotential height. The study also finds weakening in the upper level westerlies and easterlies. Interestingly, a linear trend in lower tropospheric u-wind component also reveals an east-west dipole pattern over the study region. Further, the study corroborates the reported dipole in trends of sea level pressure, wind speed and significant wave height by evaluating the influence of atmospheric variability on these parameters.
Worldwide Trends of Urinary Stone Disease Treatment Over the Last Two Decades: A Systematic Review.
Geraghty, Robert M; Jones, Patrick; Somani, Bhaskar K
2017-06-01
Numerous studies have reported on regional or national trends of stone disease treatment. However, no article has yet examined the global trends of intervention for stone disease. A systematic review of articles from 1996 to September 2016 for all English language articles reporting on trends of surgical treatment of stone disease was performed. Authors were contacted in the case of data not being clear. If the authors did not reply, data were estimated from graphs or tables. Results were analyzed using SPSS version 21, and trends were analyzed using linear regression. Our systematic review yielded 120 articles, of which 8 were included in the initial review. This reflected outcomes from six countries with available data: United Kingdom, United States, New Zealand, Australia, Canada, and Brazil. Overall ureteroscopy (URS) had a 251.8% increase in total number of treatments performed with the share of total treatments increasing by 17%. While the share of total treatments for percutaneous nephrolithotomy (PCNL) remained static, the share for extracorporeal shockwave lithotripsy and open surgery fell by 14.5% and 12%, respectively. There was significant linear regression between rising trends of total treatments year on year for URS (p < 0.001). In the last two decades, the share of total treatment for urolithiasis across the published literature has increased for URS, stable for PCNL, and decreased for lithotripsy and open surgery.
Analysis of photo linear elements, Laramie Mountains, Wyoming
NASA Technical Reports Server (NTRS)
Blackstone, D. L., Jr.
1973-01-01
The author has identified the following significant results. Photo linear features in the Precambrian rocks of the Laramie Mountains are delineated, and the azimuths plotted on rose diagrams. Three strike directions are dominant, two of which are in the northeast quadrant. Laramide folds in the Laramie basin to the west of the mountains appear to have the same trend, and apparently have been controlled by response of the basement along fractures such as have been measured from the imagery.
Demographic trends among older cannabis users in the United States, 2006–13
Han, Benjamin H.; Sherman, Scott; Mauro, Pia M.; Martins, Silvia S.; Rotenberg, James; Palamar, Joseph J.
2017-01-01
Background and Aims The ageing US population is providing an unprecedented population of older adults who use recreational drugs. We aimed to estimate the trends in the prevalence of past-year use of cannabis, describe the patterns and attitudes and determine correlates of cannabis use by adults age 50 years and older. Design Secondary analysis of the National Survey on Drug Use and Health survey from 2006 to 2013, a cross-sectional survey given to a nationally representative probability sample of populations living in US households. Setting USA. Participants A total of 47 140 survey respondents aged ≥ 50 years. Measures Estimates and trends of past-year use of cannabis. Findings The prevalence of past-year cannabis use among adults aged ≥ 50 increased significantly from 2006/07 to 2012/13, with a 57.8% relative increase for adults aged 50–64 (linear trend P < 0.001) and a 250% relative increase for those aged ≥ 65 (linear trend P = 0.002). When combining data from 2006 to 2013, 6.9% of older cannabis users met criteria for cannabis abuse or dependence, and the majority of the sample reported perceiving no risk or slight risk associated with monthly cannabis use (85.3%) or weekly use (79%). Past-year users were more likely to be younger, male, non-Hispanic, not have multiple chronic conditions and use tobacco, alcohol or other drugs compared with non-past-year cannabis users. Conclusions The prevalence of cannabis use has increased significantly in recent years among US adults aged ≥ 50 years. PMID:27767235
Albumin, bilirubin, uric acid and cancer risk: results from a prospective population-based study.
Kühn, Tilman; Sookthai, Disorn; Graf, Mirja E; Schübel, Ruth; Freisling, Heinz; Johnson, Theron; Katzke, Verena; Kaaks, Rudolf
2017-11-07
It has long been proposed that albumin, bilirubin and uric acid may inhibit cancer development due to their anti-oxidative properties. However, there is a lack of population-based studies on blood levels of these molecules and cancer risk. Associations between pre-diagnostic serum albumin, bilirubin and uric acid and the risks of common cancers as well as cancer death in the EPIC-Heidelberg cohort were evaluated by multivariable Cox regression analyses. A case-cohort sample including a random subcohort (n=2739) and all incident cases of breast (n=627), prostate (n=554), colorectal (n=256), and lung cancer (n=195) as well as cancer death (n=761) that occurred between baseline (1994-1998) and 2009 was used. Albumin levels were inversely associated with breast cancer risk (hazard ratio Quartile 4 vs Quartile 1 (95% CI): 0.71 (0.51, 0.99), P linear trend =0.004) and overall cancer mortality (HR Q4 vs Q1 (95% CI): 0.64 (0.48, 0.86), P linear trend <0.001) after multivariable adjustment. Uric acid levels were also inversely associated with breast cancer risk (HR Q4 vs Q1 (95% CI): 0.72 (0.53, 0.99), P linear trend =0.043) and cancer mortality (HR Q4 vs Q1 (95% CI): 0.75 (0.58, 0.98), P linear trend =0.09). There were no significant associations between albumin or uric acid and prostate, lung and colorectal cancer. Serum bilirubin was not associated with any cancer end point. The present findings indicate that higher levels of albumin and uric acid are related to lower risks of breast cancer and cancer mortality. Further studies are needed to assess whether the observed associations are causal.
Identifying trends in sediment discharge from alterations in upstream land use
Parker, R.S.; Osterkamp, W.R.
1995-01-01
Environmental monitoring is a primary reason for collecting sediment data. One emphasis of this monitoring is identification of trends in suspended sediment discharge. A stochastic equation was used to generate time series of annual suspended sediment discharges using statistics from gaging stations with drainage areas between 1606 and 1 805 230 km2. Annual sediment discharge was increased linearly to yield a given increase at the end of a fixed period and trend statistics were computed for each simulation series using Kendal's tau (at 0.05 significance level). A parameter was calculated from two factors that control trend detection time: (a) the magnitude of change in sediment discharge, and (b) the natural variability of sediment discharge. In this analysis the detection of a trend at most stations is well over 100 years for a 20% increase in sediment discharge. Further research is needed to assess the sensitivity of detecting trends at sediment stations.
Observed changes in relative humidity and dew point temperature in coastal regions of Iran
NASA Astrophysics Data System (ADS)
Hosseinzadeh Talaee, P.; Sabziparvar, A. A.; Tabari, Hossein
2012-12-01
The analysis of trends in hydroclimatic parameters and assessment of their statistical significance have recently received a great concern to clarify whether or not there is an obvious climate change. In the current study, parametric linear regression and nonparametric Mann-Kendall tests were applied for detecting annual and seasonal trends in the relative humidity (RH) and dew point temperature ( T dew) time series at ten coastal weather stations in Iran during 1966-2005. The serial structure of the data was considered, and the significant serial correlations were eliminated using the trend-free pre-whitening method. The results showed that annual RH increased by 1.03 and 0.28 %/decade at the northern and southern coastal regions of the country, respectively, while annual T dew increased by 0.29 and 0.15°C per decade at the northern and southern regions, respectively. The significant trends were frequent in the T dew series, but they were observed only at 2 out of the 50 RH series. The results showed that the difference between the results of the parametric and nonparametric tests was small, although the parametric test detected larger significant trends in the RH and T dew time series. Furthermore, the differences between the results of the trend tests were not related to the normality of the statistical distribution.
Rising air and stream-water temperatures in Chesapeake Bay region, USA
Rice, Karen C.; Jastram, John D.
2015-01-01
Monthly mean air temperature (AT) at 85 sites and instantaneous stream-water temperature (WT) at 129 sites for 1960–2010 are examined for the mid-Atlantic region, USA. Temperature anomalies for two periods, 1961–1985 and 1985–2010, relative to the climate normal period of 1971–2000, indicate that the latter period was statistically significantly warmer than the former for both mean AT and WT. Statistically significant temporal trends across the region of 0.023 °C per year for AT and 0.028 °C per year for WT are detected using simple linear regression. Sensitivity analyses show that the irregularly sampled WT data are appropriate for trend analyses, resulting in conservative estimates of trend magnitude. Relations between 190 landscape factors and significant trends in AT-WT relations are examined using principal components analysis. Measures of major dams and deciduous forest are correlated with WT increasing slower than AT, whereas agriculture in the absence of major dams is correlated with WT increasing faster than AT. Increasing WT trends are detected despite increasing trends in streamflow in the northern part of the study area. Continued warming of contributing streams to Chesapeake Bay likely will result in shifts in distributions of aquatic biota and contribute to worsened eutrophic conditions in the bay and its estuaries.
Buckley, Elaine Jayne; Markwell, Stephen; Farr, Debb; Sanfey, Hilary; Mellinger, John
2015-10-01
American Board of Surgery In-Service Training Examination (ABSITE) scores are used to assess individual progress and predict board pass rates. We reviewed strategies to enhance ABSITE performance and their impact within a surgery residency. Several interventions were introduced from 2010 to 2014. A retrospective review was undertaken evaluating these and correlating them to ABSITE performance. Analyses of variance and linear trends were performed for ABSITE, United States Medical Licensing Examination (USMLEs), mock oral, and mock ABSITE scores followed by post hoc analyses if significant. Results were correlated with core curricular changes. ABSITE mean percentile increased 34% in 4 years with significant performance improvement and increasing linear trends in postgraduate year (PGY)1 and PGY4 ABSITE scores. Mock ABSITE introduction correlated to significant improvement in ABSITE scores for PGY4 and PGY5. Mock oral introduction correlated with significant improvement in PGY1 and PGY3. Our study demonstrates an improvement in mean program ABSITE percentiles correlating with multiple interventions. Similar strategies may be useful for other programs. Copyright © 2015 Elsevier Inc. All rights reserved.
Simplified large African carnivore density estimators from track indices.
Winterbach, Christiaan W; Ferreira, Sam M; Funston, Paul J; Somers, Michael J
2016-01-01
The range, population size and trend of large carnivores are important parameters to assess their status globally and to plan conservation strategies. One can use linear models to assess population size and trends of large carnivores from track-based surveys on suitable substrates. The conventional approach of a linear model with intercept may not intercept at zero, but may fit the data better than linear model through the origin. We assess whether a linear regression through the origin is more appropriate than a linear regression with intercept to model large African carnivore densities and track indices. We did simple linear regression with intercept analysis and simple linear regression through the origin and used the confidence interval for ß in the linear model y = αx + ß, Standard Error of Estimate, Mean Squares Residual and Akaike Information Criteria to evaluate the models. The Lion on Clay and Low Density on Sand models with intercept were not significant ( P > 0.05). The other four models with intercept and the six models thorough origin were all significant ( P < 0.05). The models using linear regression with intercept all included zero in the confidence interval for ß and the null hypothesis that ß = 0 could not be rejected. All models showed that the linear model through the origin provided a better fit than the linear model with intercept, as indicated by the Standard Error of Estimate and Mean Square Residuals. Akaike Information Criteria showed that linear models through the origin were better and that none of the linear models with intercept had substantial support. Our results showed that linear regression through the origin is justified over the more typical linear regression with intercept for all models we tested. A general model can be used to estimate large carnivore densities from track densities across species and study areas. The formula observed track density = 3.26 × carnivore density can be used to estimate densities of large African carnivores using track counts on sandy substrates in areas where carnivore densities are 0.27 carnivores/100 km 2 or higher. To improve the current models, we need independent data to validate the models and data to test for non-linear relationship between track indices and true density at low densities.
Response to Comment on "Does the Earth Have an Adaptive Infrared Iris?"
NASA Technical Reports Server (NTRS)
Bell, Thomas L.; Chou, Ming-Dah; Lindzen, Richard S.; Hou, Arthur Y.
2001-01-01
In his comment on Lindzen et al., Harrison found that the amount of high-level clouds, A, and the sea-surface temperature beneath clouds, T, averaged over a large oceanic domain in the western Pacific have secular linear trends of opposite signs over a period of 20 months. He found that when the linear trends are subtracted from the data, the correlation between the residual A and T is much reduced. His estimates of the confidence levels for the correlation indicate, moreover, that this correlation is not statistically significant. The domain-averaged A and, to a lesser degree, T, have distinct intra-seasonal and seasonal variations. These variations are influenced by the large-scale wind and temperature distributions and by the seasonal variation of insolation. To separate the local effect from the effect of slowly changing large-scale conditions, rather than subtracting 20-month linear trends from the series, which has the potential to spuriously extrapolate intra-seasonal and seasonal variations to even longer time scales, we subtracted 30-day running means of A and T from each time series; in effect, the data were high-pass filtered. The number of points (days), N, is reduced by this process from the original value of 510 to 480.
Arginine intake is associated with oxidative stress in a general population.
Carvalho, Aline Martins de; Oliveira, Antonio Anax Falcão de; Loureiro, Ana Paula de Melo; Gattás, Gilka Jorge Figaro; Fisberg, Regina Mara; Marchioni, Dirce Maria
2017-01-01
The aim of this study was to assess the association between protein and arginine from meat intake and oxidative stress in a general population. Data came from the Health Survey for Sao Paulo (ISA-Capital), a cross-sectional population-based study in Brazil (N = 549 adults). Food intake was estimated by a 24-h dietary recall. Oxidative stress was estimated by malondialdehyde (MDA) concentration in plasma. Analyses were performed using general linear regression models adjusted for some genetic, lifestyle, and biochemical confounders. MDA levels were associated with meat intake (P for linear trend = 0.031), protein from meat (P for linear trend = 0.006), and arginine from meat (P for linear trend = 0.044) after adjustments for confounders: age, sex, body mass index, smoking, physical activity, intake of fruit and vegetables, energy and heterocyclic amines, C-reactive protein levels, and polymorphisms in GSTM1 (glutathione S-transferase Mu 1) and GSTT1 (glutathione S-transferase theta 1) genes. Results were not significant for total protein and protein from vegetable intake (P > 0.05). High protein and arginine from meat intake were associated with oxidative stress independently of genetic, lifestyle, and biochemical confounders in a population-based study. Our results suggested a novel link between high protein/arginine intake and oxidative stress, which is a major cause of age-related diseases. Copyright © 2016 Elsevier Inc. All rights reserved.
Techniques for analyses of trends in GRUAN data
NASA Astrophysics Data System (ADS)
Bodeker, G. E.; Kremser, S.
2015-04-01
The Global Climate Observing System (GCOS) Reference Upper Air Network (GRUAN) provides reference quality RS92 radiosonde measurements of temperature, pressure and humidity. A key attribute of reference quality measurements, and hence GRUAN data, is that each datum has a well characterized and traceable estimate of the measurement uncertainty. The long-term homogeneity of the measurement records, and their well characterized uncertainties, make these data suitable for reliably detecting changes in global and regional climate on decadal time scales. Considerable effort is invested in GRUAN operations to (i) describe and analyse all sources of measurement uncertainty to the extent possible, (ii) quantify and synthesize the contribution of each source of uncertainty to the total measurement uncertainty, and (iii) verify that the evaluated net uncertainty is within the required target uncertainty. However, if the climate science community is not sufficiently well informed on how to capitalize on this added value, the significant investment in estimating meaningful measurement uncertainties is largely wasted. This paper presents and discusses the techniques that will need to be employed to reliably quantify long-term trends in GRUAN data records. A pedagogical approach is taken whereby numerical recipes for key parts of the trend analysis process are explored. The paper discusses the construction of linear least squares regression models for trend analysis, boot-strapping approaches to determine uncertainties in trends, dealing with the combined effects of autocorrelation in the data and measurement uncertainties in calculating the uncertainty on trends, best practice for determining seasonality in trends, how to deal with co-linear basis functions, and interpreting derived trends. Synthetic data sets are used to demonstrate these concepts which are then applied to a first analysis of temperature trends in RS92 radiosonde upper air soundings at the GRUAN site at Lindenberg, Germany (52.21° N, 14.12° E).
Techniques for analyses of trends in GRUAN data
NASA Astrophysics Data System (ADS)
Bodeker, G. E.; Kremser, S.
2014-12-01
The Global Climate Observing System (GCOS) Reference Upper Air Network (GRUAN) provides reference quality RS92 radiosonde measurements of temperature, pressure and humidity. A key attribute of reference quality measurements, and hence GRUAN data, is that each datum has a well characterised and traceable estimate of the measurement uncertainty. The long-term homogeneity of the measurement records, and their well characterised uncertainties, make these data suitable for reliably detecting changes in global and regional climate on decadal time scales. Considerable effort is invested in GRUAN operations to (i) describe and analyse all sources of measurement uncertainty to the extent possible, (ii) quantify and synthesize the contribution of each source of uncertainty to the total measurement uncertainty, and (iii) verify that the evaluated net uncertainty is within the required target uncertainty. However, if the climate science community is not sufficiently well informed on how to capitalize on this added value, the significant investment in estimating meaningful measurement uncertainties is largely wasted. This paper presents and discusses the techniques that will need to be employed to reliably quantify long-term trends in GRUAN data records. A pedagogical approach is taken whereby numerical recipes for key parts of the trend analysis process are explored. The paper discusses the construction of linear least squares regression models for trend analysis, boot-strapping approaches to determine uncertainties in trends, dealing with the combined effects of autocorrelation in the data and measurement uncertainties in calculating the uncertainty on trends, best practice for determining seasonality in trends, how to deal with co-linear basis functions, and interpreting derived trends. Synthetic data sets are used to demonstrate these concepts which are then applied to a first analysis of temperature trends in RS92 radiosonde upper air soundings at the GRUAN site at Lindenberg, Germany (52.21° N, 14.12° E).
Salazar, Edwin; Buitrago, Carolina; Molina, Federico; Alzate, Catalina Arango
2015-05-01
Determine the trend in mortality from external causes in pregnant and postpartum women and its relationship to socioeconomic factors. Descriptive study, based on the official registries of deaths reported by the National Statistics Agency, 1998-2010. The trend was analyzed using Poisson regressions. Bivariate correlations and multiple linear regression models were constructed to explore the relationship between mortality and socioeconomic factors: human development index, Gini index, gross domestic product, unsatisfied basic needs, unemployment rate, poverty, extreme poverty, quality of life index, illiteracy rate, and percentage of affiliation to the Social Security System. A total of 2 223 female deaths from external causes were recorded, of which 1 429 occurred during pregnancy and 794 in the postpartum period. The gross mortality rate dropped from 30.7 per 100 000 live births plus fetal deaths in 1998 to 16.7 in 2010. A downward curve with no significant inflection points was shown in the risk of dying from this cause. The multiple linear regression model showed a correlation between mortality and extreme poverty and the illiteracy rate, suggesting that these indicators could explain 89.4% of the change in mortality from external causes in pregnant and postpartum women each year in Colombia. Mortality from external causes in pregnant and postpartum women showed a significant downward trend that may be explained by important socioeconomic changes in the country, including a decrease in extreme poverty and in the illiteracy rate.
Effects of urbanization on climate of İstanbul and Ankara
NASA Astrophysics Data System (ADS)
Karaca, Mehmet; Tayanç, Mete; Toros, Hüseyi˙n.
The purpose of this work is to study regional climate change and investigate the effects of urbanization on climates of two largest cities in Turkey: İstanbul and Ankara. Air temperature (mean, maximum and minimum) data of İstanbul and Ankara are analyzed to study regional climate change and to understand the possible effects of urbanization on the climate of these regions owing to industrialization and large flux of migration from rural parts of the country. For the trend analysis, linear regression and the sequential version of the Mann-Kendall test is used. A significant upward trend is found in the urban temperatures of southern İstanbul, which is the most highly populated and industrialized part of the city compared to its rural parts. Northern stations do not show any warming trend; instead, they have a cooling trend. Urbanization and industrialization in the southern part of İstanbul has a negative effect on regional cooling. In spite of Ankara's urban geometry and air pollution problem, the urban station in Ankara does not show any warming trend. A significant urban heat island intensity ( urban-rural) is not observed in Ankara.
Ross, Michael W; Risser, Jan; Peters, Ronald J; Johnson, Regina J
2006-01-01
There has been speculation that trends in syphilis have been fueled by crack cocaine use. This study examined the data on syphilis notifications and arrestee drug abuse monitoring (ADAM) to ascertain the relationships between syphilis and cocaine use trends in three racial/ethnic groups. Syphilis notifications and data from the ADAM project were compared in Houston/Harris County, Texas, from 1991-1998 using a linear regression equation. Data indicated significant relationships between the data for cocaine use and syphilis in African Americans but not Hispanics or non-Hispanic whites. For African Americans, 58% of the variance between cocaine use and syphilis was explained. When data limited to jail syphilis notifications and ADAM cocaine in African Americans were examined, the association was stronger for males than for females. For African Americans, cocaine (probably crack cocaine) use trends were significantly associated with syphilis trends in this population. These data suggest that control of crack cocaine may have an impact on syphilis rates and that there may be close relationships between some STDs and drug abuse.
Modeled and observed ozone sensitivity to mobile-source emissions in Mexico City
NASA Astrophysics Data System (ADS)
Zavala, M.; Lei, W.; Molina, M. J.; Molina, L. T.
2009-01-01
The emission characteristics of mobile sources in the Mexico City Metropolitan Area (MCMA) have changed significantly over the past few decades in response to emission control policies, advancements in vehicle technologies and improvements in fuel quality, among others. Along with these changes, concurrent non-linear changes in photochemical levels and criteria pollutants have been observed, providing a unique opportunity to understand the effects of perturbations of mobile emission levels on the photochemistry in the region using observational and modeling approaches. The observed historical trends of ozone (O3), carbon monoxide (CO) and nitrogen oxides (NOx) suggest that ozone production in the MCMA has changed from a low to a high VOC-sensitive regime over a period of 20 years. Comparison of the historical emission trends of CO, NOx and hydrocarbons derived from mobile-source emission studies in the MCMA from 1991 to 2006 with the trends of the concentrations of CO, NOx, and the CO/NOx ratio during peak traffic hours also indicates that fuel-based fleet average emission factors have significantly decreased for CO and VOCs during this period whereas NOx emission factors do not show any strong trend, effectively reducing the ambient VOC/NOx ratio. This study presents the results of model analyses on the sensitivity of the observed ozone levels to the estimated historical changes in its precursors. The model sensitivity analyses used a well-validated base case simulation of a high pollution episode in the MCMA with the mathematical Decoupled Direct Method (DDM) and the standard Brute Force Method (BFM) in the 3-D CAMx chemical transport model. The model reproduces adequately the observed historical trends and current photochemical levels. Comparison of the BFM and the DDM sensitivity techniques indicates that the model yields ozone values that increase linearly with NOx emission reductions and decrease linearly with VOC emission reductions only up to 30% from the base case. We further performed emissions perturbations from the gasoline fleet, diesel fleet, all mobile (gasoline plus diesel) and all emission sources (anthropogenic plus biogenic). The results suggest that although large ozone reductions obtained in the past were from changes in emissions from gasoline vehicles, currently significant benefits could be achieved with additional emission control policies directed to regulation of VOC emissions from diesel and area sources that are high emitters of alkenes, aromatics and aldehydes.
Modeled and observed ozone sensitivity to mobile-source emissions in Mexico City
NASA Astrophysics Data System (ADS)
Zavala, M.; Lei, W. F.; Molina, M. J.; Molina, L. T.
2008-08-01
The emission characteristics of mobile sources in the Mexico City Metropolitan Area (MCMA) have changed significantly over the past few decades in response to emission control policies, advancements in vehicle technologies and improvements in fuel quality, among others. Along with these changes, concurrent non-linear changes in photochemical levels and criteria pollutants have been observed, providing a unique opportunity to understand the effects of perturbations of mobile emission levels on the photochemistry in the region using observational and modeling approaches. The observed historical trends of ozone (O3), carbon monoxide (CO) and nitrogen oxides (NOx) suggest that ozone production in the MCMA has changed from a low to a high VOC-sensitive regime over a period of 20 years. Comparison of the historical emission trends of CO, NOx and hydrocarbons derived from mobile-source emission studies in the MCMA from 1991 to 2006 with the trends of the concentrations of CO, NOx, and the CO/NOx ratio during peak traffic hours also indicates that fuel-based fleet average emission factors have significantly decreased for CO and VOCs during this period whereas NOx emission factors do not show any strong trend, effectively reducing the ambient VOC/NOx ratio. This study presents the results of model analyses on the sensitivity of the observed ozone levels to the estimated historical changes in its precursors. The model sensitivity analyses used a well-validated base case simulation of a high pollution episode in the MCMA with the mathematical Decoupled Direct Method (DDM) and the standard Brute Force Method (BFM) in the 3-D CAMx chemical transport model. The model reproduces adequately the observed historical trends and current photochemical levels. Comparison of the BFM and the DDM sensitivity techniques indicates that the model yields ozone values that increase linearly with NOx emission reductions and decrease linearly with VOC emission reductions only up to 30% from the base case. We further performed emissions perturbations from the gasoline fleet, diesel fleet, all mobile (gasoline plus diesel) and all emission sources (anthropogenic plus biogenic). The results suggest that although large ozone reductions obtained in the past were from changes in emissions from gasoline vehicles, currently significant benefits could be achieved with additional emission control policies directed to regulation of VOC emissions from diesel and area sources that are high emitters of alkenes, aromatics and aldehydes.
Ko, Ki Dong; Cho, BeLong; Lee, Won Chul; Lee, Hae Won; Lee, Hyun Ki; Oh, Bum Jo
2015-03-01
This study aimed to examine the association of educational level with metabolic syndrome (MS) and its risk factors by gender in South Korea. A total of 6178 participants aged 20 years or older from The Fifth Korean National Health and Nutrition Examination Survey were included in this study. A generalized linear model and adjusted proportion were used to identify educational disparities in MS, its components, and its risk factors (smoking, high-risk alcohol consumption, obesity, and stress). In women, a clearly inverse association between education level and MS were observed with significant trend, and the decreasing trends of all risk factors across education quartiles were in line with the inverse association. However, the association between education level and MS was not observed with a significant trend among men. An opposite trend of risk factors across education levels was shown in men, with an increasing trend for obesity and decreasing trends for smoking and high-risk alcohol consumption. These findings demonstrate that obesity can explain gender differences in the association between education level and MS in South Korea. © 2013 APJPH.
Trends in risk factors for coronary heart disease in the Netherlands.
Koopman, C; Vaartjes, I; Blokstra, A; Verschuren, W M M; Visser, M; Deeg, D J H; Bots, M L; van Dis, I
2016-08-19
Favourable trends in risk factor levels in the general population may partly explain the decline in coronary heart disease (CHD) morbidity and mortality. Our aim was to present long-term national trends in established risk factors for CHD. Data were obtained from five data sources including several large scale population based surveys, cohort studies and general practitioner registers between 1988 and 2012. We applied linear regression models to age-standardized time trends to test for statistical significant trends. Analyses were stratified by sex and age (younger <65 and older ≥65 years adults). The results demonstrated favourable trends in smoking (except in older women) and physical activity (except in older men). Unfavourable trends were found for body mass index (BMI) and diabetes mellitus prevalence. Although systolic blood pressure (SBP) and total cholesterol trends were favourable for older persons, SBP and total cholesterol remained stable in younger persons. Four out of six risk factors for CHD showed a favourable or stable trend. The rise in diabetes mellitus and BMI is worrying with respect to CHD morbidity and mortality.
Comparison of climate related changes in two Arctic fjords, Hornsund and Porsanger
NASA Astrophysics Data System (ADS)
Aniskiewicz, Paulina; Stramska, Małgorzata
2017-04-01
In the Arctic zone the climate change is amplified in comparison to globally averaged trends, and the observed trends are variable spatially. Our research is focused on two Artic fjords: Porsanger and Horsund. Porsanger fjord is located in the coastal waters of the Barents Sea. Hornsund is one of fjords located in the western part of Svalbard archipelago. In this presentation we have used data provided by the Norwegian Meteorological Institute for three meteorological stations. Two of them are located in the Porsanger fjord (Lakselv - in the inner part, Honningsvåg - in the outer zone). The third station provides data from the Hornsund fjord. Using these data we have estimated the 33-year trends (1983-2015) of air temperature and relative humidity in each station using linear regression analysis (statistically significant at 95In the inner part of the Porsanger fjord (Lakselv) the multiyear trend of increasing annual mean air temperature has been estimated at 0.006°C per year. The monthly trends were statistically significant in May, September and November. The strongest seasonal warming has been observed in spring and autumn. The trends of increasing annual mean humidity was about 0.2In Hornsund the air temperature trend (0.2°C per year) is significantly larger than in Porsanger. The trends of air temperature were statistically significant for eight months (except March, April, June and July) and three seasons (besides spring). The trends of relative humidity were not statistically significant. Thanks to this research we can discuss how atmospheric conditions and climate related trends change in time and seasons of the year in two different Arctic regions. The project has been financed from the funds of the Leading National Research Centre (KNOW) received by the Centre for Polar Studies for the period 2014-2018. This work was also funded by the Norway Grants (NCBR contract No. 201985, project NORDFLUX). Partial support comes from the Institute of Oceanology (IO PAN).
Nistal-Nuño, Beatriz
2017-03-31
In Chile, a new law introduced in March 2012 lowered the blood alcohol concentration (BAC) limit for impaired drivers from 0.1% to 0.08% and the BAC limit for driving under the influence of alcohol from 0.05% to 0.03%, but its effectiveness remains uncertain. The goal of this investigation was to evaluate the effects of this enactment on road traffic injuries and fatalities in Chile. A retrospective cohort study. Data were analyzed using a descriptive and a Generalized Linear Models approach, type of Poisson regression, to analyze deaths and injuries in a series of additive Log-Linear Models accounting for the effects of law implementation, month influence, a linear time trend and population exposure. A review of national databases in Chile was conducted from 2003 to 2014 to evaluate the monthly rates of traffic fatalities and injuries associated to alcohol and in total. It was observed a decrease by 28.1 percent in the monthly rate of traffic fatalities related to alcohol as compared to before the law (P<0.001). Adding a linear time trend as a predictor, the decrease was by 20.9 percent (P<0.001).There was a reduction in the monthly rate of traffic injuries related to alcohol by 10.5 percent as compared to before the law (P<0.001). Adding a linear time trend as a predictor, the decrease was by 24.8 percent (P<0.001). Positive results followed from this new 'zero-tolerance' law implemented in 2012 in Chile. Chile experienced a significant reduction in alcohol-related traffic fatalities and injuries, being a successful public health intervention.
NASA Astrophysics Data System (ADS)
Farahani, Hassan H.; Ditmar, Pavel; Inácio, Pedro; Didova, Olga; Gunter, Brian; Klees, Roland; Guo, Xiang; Guo, Jing; Sun, Yu; Liu, Xianglin; Zhao, Qile; Riva, Riccardo
2017-01-01
We present a high resolution model of the linear trend in the Earth's mass variations based on DMT-2 (Delft Mass Transport model, release 2). DMT-2 was produced primarily from K-Band Ranging (KBR) data of the Gravity Recovery And Climate Experiment (GRACE). It comprises a time series of monthly solutions complete to spherical harmonic degree 120. A novel feature in its production was the accurate computation and incorporation of stochastic properties of coloured noise when processing KBR data. The unconstrained DMT-2 monthly solutions are used to estimate the linear trend together with a bias, as well as annual and semi-annual sinusoidal terms. The linear term is further processed with an anisotropic Wiener filter, which uses full noise and signal covariance matrices. Given the fact that noise in an unconstrained model of the trend is reduced substantially as compared to monthly solutions, the Wiener filter associated with the trend is much less aggressive compared to a Wiener filter applied to monthly solutions. Consequently, the trend estimate shows an enhanced spatial resolution. It allows signals in relatively small water bodies, such as Aral sea and Ladoga lake, to be detected. Over the ice sheets, it allows for a clear identification of signals associated with some outlet glaciers or their groups. We compare the obtained trend estimate with the ones from the CSR-RL05 model using (i) the same approach based on monthly noise covariance matrices and (ii) a commonly-used approach based on the DDK-filtered monthly solutions. We use satellite altimetry data as independent control data. The comparison demonstrates a high spatial resolution of the DMT-2 linear trend. We link this to the usage of high-accuracy monthly noise covariance matrices, which is due to an accurate computation and incorporation of coloured noise when processing KBR data. A preliminary comparison of the linear trend based on DMT-2 with that computed from GSFC_global_mascons_v01 reveals, among other, a high concentration of the signal along the coast for both models in areas like the ice sheets, Gulf of Alaska, and Iceland.
Taylor, Richard; Linhart, Christine; Hayes, Geoffrey; Homasi, Steven
2014-08-01
Infant mortality rates (IMR) and under-five mortality rates (U5MR) in Tuvalu (2010 population 11,149) for 1990-2011 were evaluated to determine best estimates of levels and trends. Estimates were graphed over time to identify trends/inconsistencies, and censored for reliability/plausibility. Where possible, 95% confidence intervals (CIs) and tests for linear trend were calculated. Ministry of Health (MoH) data indicates IMR and U5MR (per 1,000 live births) declined over 1990-2008: IMR 62 (95%CI 46-81) for 1991-93 (51 deaths) to 19 (95%CI 10-33) for 2006-08 (12 deaths); U5MR 67 (95%CI 50-87) for 1991-93 (55 deaths) to 19 (95%CI 10-33) for 2006-08 (12 deaths). The 2007 Demographic and Health Survey (DHS) suggests recent trends are increasing: IMR 24 for 1998-2002 to 31 (95%CI 20-42) for 2003-07; U5MR 29 for 1998-2002 to 36 (95%CI 30-43) for 2003-07 (deaths not provided). Tests for linear trend and 95%CIs indicate MoH declines are statistically significant, but recent increased estimates from DHS are not, and could be affected by recall bias. Small populations provide challenges in interpretation of IMR/U5MR trends. To ensure the correct interpretation of rates, CIs (95%) and tests for trend should be calculated. Tuvalu has experienced steady decline in IMR/U5MR over the past 20 years. © 2014 Public Health Association of Australia.
Bernstein, David N; Jain, Amit; Brodell, David; Li, Yue; Rubery, Paul T; Mesfin, Addisu
2016-12-01
To analyze overall trends of elective cervical spine surgery in the United States from 2003 to 2013 with the goal of determining whether the economic downturn had an impact. Codes from the International Classification of Diseases, Ninth Revision, Clinical Modification were used to identify elective cervical spine surgery procedures in the Nationwide Inpatient Sample from 2003 to 2013. National Health Expenditure, gross domestic product, and S&P 500 Index were used as measures of economic performance. The economic downturn was defined as 2008-2009. Confidence intervals were determined using subgroup analysis techniques. Linear regressions were completed to determine the association between surgery trends and economic conditions. From 2003 to 2013, posterior cervical fusions saw a 102.7% increase. During the same time frame, there was a 7.4% and 14.7% decrease in the number of anterior cervical diskectomy and fusions (ACDFs) and posterior decompressions, respectively. The trend of elective cervical spine surgeries per 100,000 persons in the U.S. population may have been affected by the economic downturn from 2008 to 2009 (-0.03% growth). The percentage of procedures paid for by private insurance decreased from 2003 to 2013 for all ACDFs, posterior cervical fusions, and posterior decompressions. The linear regression coefficients (β) and R 2 values between the number of surgeries and each of the macroeconomic factors analyzed were not statistically significant. The overall elective cervical spine surgery trend was not likely impacted by the economic downturn. Posterior cervical fusions grew significantly from 2003 to 2013, whereas ACDFs and posterior decompressions decreased. Copyright © 2016 Elsevier Inc. All rights reserved.
NASA Astrophysics Data System (ADS)
An, S.; Chen, X.
2015-12-01
Based on the MODIS MCD12Q2 remote sensing phenology product, we analyzed spatiotemporal variations of vegetation green-up, maturity, senescence and brown-off dates, and their relation to spatiotemporal patterns of air temperature and precipitation on the Qinghai-Tibet Plateau (QTP). From 2001 to 2012, phenological time series at about 11.7%~15.1% pixels indicate significant linear trends (P<0.1) with strong spatial consistency. Namely, pixels with significant phenological advancement and growing season lengthening are mainly distributed in the middle and eastern parts of the QTP, while pixels with significant phenological delay and growing season shortening are mainly distributed in the western and southern parts as well as the eastern edge of the QTP. Similar spatial patterns for positive and negative linear trends of the minimum and maximum EVI, and the time-integrated EVI during the growing season were detected in the above two regions, respectively. With regard to climatic factors, mean annual temperature shows an increased trend over the QTP except for the eastern edge, whereas annual precipitation displays an increased trend in the middle and eastern parts but a decreased trend in the western and southern parts as well as the eastern edge of the QTP. These findings suggest that phenological advancement, growing season lengthening, and vegetation activity enhancement in the middle and eastern parts might be attributed to coincident temperature and precipitation increase. By contrast, phenological delay, growing season shortening, and vegetation activity reduction in the western and southern parts as well as the eastern edge might be caused by opposite changes of temperature and precipitation, and strong evaporation induced water shortage. Furthermore, a partial correlation analysis indicates that green-up, maturity, and brown-off dates were influenced by preceding temperature and precipitation, while senescence date was affected by preceding precipitation.
Trends in abuse and misuse of prescription opioids among older adults.
West, Nancy A; Severtson, Stevan G; Green, Jody L; Dart, Richard C
2015-04-01
Dramatic increases in the prescriptive use of opioid analgesics during the past two decades have been paralleled by alarming increases in rates of the abuse and intentional misuse of these drugs. We examined recent trends in the abuse and misuse and associated fatal outcomes among older adults (60+ years) and compared these to trends among younger adults (20-59 years). Trend analysis using linear regression models was used to analyze 184,136 cases and 1149 deaths associated with abuse and misuse of the prescription opioids oxycodone, fentanyl, hydrocodone, morphine, oxymorphone, hydromorphone, methadone, buprenorphine, tramadol, and tapentadol that were reported to participating U.S. Poison Centers of the Researched Abuse, Diversion and Addiction-Related Surveillance (RADARS(®)) System between 2006-Q1 and 2013-Q4. Rates of abuse and misuse of prescription opioids were lower for older adults than for younger adults; however, mortality rates among the older ages followed an increasing linear trend (P < 0.0001) and surpassed rates for younger adults in 2012 and 2013. In contrast, mortality rates among younger adults rose and fell during the period, with recent rates trending downward (P = 0.0003 for quadratic trend). Sub-analysis revealed an increasing linear trend among older adults specifically for suicidal intent (P < 0.0001), whereas these rates increased and then decreased among younger adults (P < 0.0001 for quadratic trend). Recent linear increases in rates of death and use of prescription opioids with suicidal intent among older adults have important implications as the U.S. undergoes a rapid expansion of its elderly population. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
Non-linear patterns in age-related DNA methylation may reflect CD4+ T cell differentiation
Johnson, Nicholas D.; Wiener, Howard W.; Smith, Alicia K.; Nishitani, Shota; Absher, Devin M.; Arnett, Donna K.; Aslibekyan, Stella; Conneely, Karen N.
2017-01-01
ABSTRACT DNA methylation (DNAm) is an important epigenetic process involved in the regulation of gene expression. While many studies have identified thousands of loci associated with age, few have differentiated between linear and non-linear DNAm trends with age. Non-linear trends could indicate early- or late-life gene regulatory processes. Using data from the Illumina 450K array on 336 human peripheral blood samples, we identified 21 CpG sites that associated with age (P<1.03E-7) and exhibited changing rates of DNAm change with age (P<1.94E-6). For 2 of these CpG sites (cg07955995 and cg22285878), DNAm increased with age at an increasing rate, indicating that differential DNAm was greatest among elderly individuals. We observed significant replication for both CpG sites (P<5.0E-8) in a second set of peripheral blood samples. In 8 of 9 additional data sets comprising samples of monocytes, T cell subtypes, and brain tissue, we observed a pattern directionally consistent with DNAm increasing with age at an increasing rate, which was nominally significant in the 3 largest data sets (4.3E-15
Gender-Specific Trends in Educational Attainment and Self-Rated Health, 1972–2002
Hill, Terrence D.; Needham, Belinda L.
2006-01-01
Objectives. We tested whether self-rated health has improved over time (1972–2002) for women and men. We also considered the degree to which historical gains in educational attainment help to explain any observed trends. Methods. Using 21 years of repeated cross-sectional data from the General Social Survey, we estimated a series of ordered logistic regression models predicting self-rated health. Results. Our results show that women’s health status has steadily improved over the 30-year period under study, and these improvements are largely explained by gains in educational attainment. We also found that the health trend for men is nonlinear, suggesting significant fluctuations in health status over time. Conclusions. Based on the linear health status trend and strong mediation pattern for women, and the nonlinear health status trend for men, women have benefited more than men, in terms of self-rated health, from increased educational attainment. PMID:16735623
NASA Astrophysics Data System (ADS)
Banzhaf, S.; Schaap, M.; Kranenburg, R.; Manders, A. M. M.; Segers, A. J.; Visschedijk, A. H. J.; Denier van der Gon, H. A. C.; Kuenen, J. J. P.; van Meijgaard, E.; van Ulft, L. H.; Cofala, J.; Builtjes, P. J. H.
2014-07-01
In this study we present a dynamic model evaluation of the chemistry transport model LOTOS-EUROS to analyse the ability of the model to reproduce observed non-linear responses to emission changes and interannual variability of secondary inorganic aerosol (SIA) and its precursors over Europe from 1990 to 2009. The 20 year simulation was performed using a consistent set of meteorological data provided by the regional climate model RACMO2. Observations at European rural background sites have been used as reference for the model evaluation. To ensure the consistency of the used observational data stringent selection criteria were applied including a comprehensive visual screening to remove suspicious data from the analysis. The LOTOS-EUROS model was able to capture a large part of the day-to-day, seasonal and interannual variability of SIA and its precursors' concentrations. The dynamic evaluation has shown that the model is able to simulate the declining trends observed for all considered sulphur and nitrogen components following the implementation of emission abatement strategies for SIA precursors over Europe. Both, the observations and the model show the largest part of the decline in the 1990's while smaller concentration changes and an increasing number of non-significant trends are observed and modelled between 2000-2009. Furthermore, the results confirm former studies showing that the observed trends in sulphate and total nitrate concentrations from 1990 to 2009 are significantly lower than the trends in precursor emissions and precursor concentrations. The model captured these non-linear responses to the emission changes well. Using the LOTOS-EUROS source apportionment module trends in formation efficiency of SIA have been quantified for four European regions. The exercise has revealed a 20-50% more efficient sulphate formation in 2009 compared to 1990 and an up to 20% more efficient nitrate formation per unit nitrogen oxide emission, which added to the explanation of the non-linear responses. However, we have also identified some weaknesses to the model and the input data. LOTOS-EUROS underestimates the observed nitrogen dioxide concentrations throughout the whole time period, while it overestimates the observed nitrogen dioxide concentration trends. Moreover, model results suggest that the emission information of the early 1990's used in this study needs to be improved concerning magnitude and spatial distribution.
Trends in evaporation of a large subtropical lake
NASA Astrophysics Data System (ADS)
Hu, Cheng; Wang, Yongwei; Wang, Wei; Liu, Shoudong; Piao, Meihua; Xiao, Wei; Lee, Xuhui
2017-07-01
How rising temperature and changing solar radiation affect evaporation of natural water bodies remains poor understood. In this study, evaporation from Lake Taihu, a large (area 2400 km2) freshwater lake in the Yangtze River Delta, China, was simulated by the CLM4-LISSS offline lake model and estimated with pan evaporation data. Both methods were calibrated against lake evaporation measured directly with eddy covariance in 2012. Results show a significant increasing trend of annual lake evaporation from 1979 to 2013, at a rate of 29.6 mm decade-1 according to the lake model and 25.4 mm decade-1 according to the pan method. The mean annual evaporation during this period shows good agreement between these two methods (977 mm according to the model and 1007 mm according to the pan method). A stepwise linear regression reveals that downward shortwave radiation was the most significant contributor to the modeled evaporation trend, while air temperature was the most significant contributor to the pan evaporation trend. Wind speed had little impact on the modeled lake evaporation but had a negative contribution to the pan evaporation trend offsetting some of the temperature effect. Reference evaporation was not a good proxy for the lake evaporation because it was on average 20.6 % too high and its increasing trend was too large (56.5 mm decade-1).
Detection of carbon monoxide trends in the presence of interannual variability
NASA Astrophysics Data System (ADS)
Strode, Sarah A.; Pawson, Steven
2013-11-01
in fossil fuel emissions are a major driver of changes in atmospheric CO, but detection of trends in CO from anthropogenic sources is complicated by the presence of large interannual variability (IAV) in biomass burning. We use a multiyear model simulation of CO with year-specific biomass burning to predict the number of years needed to detect the impact of changes in Asian anthropogenic emissions on downwind regions. Our study includes two cases for changing anthropogenic emissions: a stepwise change of 15% and a linear trend of 3% yr-1. We first examine how well the model reproduces the observed IAV of CO over the North Pacific, since this variability impacts the time needed to detect significant anthropogenic trends. The modeled IAV over the North Pacific correlates well with that seen from the Measurements of Pollution in the Troposphere (MOPITT) instrument but underestimates the magnitude of the variability. The model predicts that a 3% yr-1 trend in Asian anthropogenic emissions would lead to a statistically significant trend in CO surface concentration in the western United States within 12 years, and accounting for Siberian boreal biomass-burning emissions greatly reduces the number of years needed for trend detection. Combining the modeled trend with the observed MOPITT variability at 500 hPa, we estimate that the 3% yr-1 trend could be detectable in satellite observations over Asia in approximately a decade. Our predicted timescales for trend detection highlight the importance of long-term measurements of CO from satellites.
Mineral exploration and fracture trends in Utah and Nevada, by ERTS-1 imagery
NASA Technical Reports Server (NTRS)
Jensen, M. L. (Principal Investigator); Smith, M. R.
1973-01-01
The author has identified the following significant results. Major structural trends have been compiled on five separate maps, at a scale of 1:1,000,000, of Utah and Nevada from ERTS-1 imagery. An arbitrary length of ten kilometers has been chosen as a minimum length of the trends. The selection is based upon: (1) obvious displacement of structures; (2) continuity or persistence of trends across structures; (3) line-up of outcrop patterns, drainage, erosional features or vegetation; and (4) near-linear trends. Several recognizable trend directions have noted, viz., N 10-15 deg W, N 35 deg W, N 80 deg W, N 30 deg E, and E-W. More than 1500 structural trends have been identified, some of which are mineralized and extend into pediment or shallow alluvial cover. Those fracture trends that exhibit mineralization in exposed bedrock will be assayed for mercury content with a soil-gas analyzer and similar collection will be done over alluvial posture blankets by the same technique with the hope of discovering blind mineralized zones that are not exposed on the surface.
Trends in mean and extreme temperatures over Ibadan, Southwest Nigeria
NASA Astrophysics Data System (ADS)
Abatan, Abayomi A.; Osayomi, Tolulope; Akande, Samuel O.; Abiodun, Babatunde J.; Gutowski, William J.
2018-02-01
In recent times, Ibadan has been experiencing an increase in mean temperature which appears to be linked to anthropogenic global warming. Previous studies have indicated that the warming may be accompanied by changes in extreme events. This study examined trends in mean and extreme temperatures over Ibadan during 1971-2012 at annual and seasonal scales using the high-resolution atmospheric reanalysis from European Centre for Medium-Range Weather Forecasts (ECMWF) twentieth-century dataset (ERA-20C) at 15 grid points. Magnitudes of linear trends in mean and extreme temperatures and their statistical significance were calculated using ordinary least squares and Mann-Kendall rank statistic tests. The results show that Ibadan has witnessed an increase in annual and seasonal mean minimum temperatures. The annual mean maximum temperature exhibited a non-significant decline in most parts of Ibadan. While trends in cold extremes at annual scale show warming, trends in coldest night show greater warming than in coldest day. At the seasonal scale, we found that Ibadan experienced a mix of positive and negative trends in absolute extreme temperature indices. However, cold extremes show the largest trend magnitudes, with trends in coldest night showing the greatest warming. The results compare well with those obtained from a limited number of stations. This study should inform decision-makers and urban planners about the ongoing warming in Ibadan.
Linear and nonlinear trending and prediction for AVHRR time series data
NASA Technical Reports Server (NTRS)
Smid, J.; Volf, P.; Slama, M.; Palus, M.
1995-01-01
The variability of AVHRR calibration coefficient in time was analyzed using algorithms of linear and non-linear time series analysis. Specifically we have used the spline trend modeling, autoregressive process analysis, incremental neural network learning algorithm and redundancy functional testing. The analysis performed on available AVHRR data sets revealed that (1) the calibration data have nonlinear dependencies, (2) the calibration data depend strongly on the target temperature, (3) both calibration coefficients and the temperature time series can be modeled, in the first approximation, as autonomous dynamical systems, (4) the high frequency residuals of the analyzed data sets can be best modeled as an autoregressive process of the 10th degree. We have dealt with a nonlinear identification problem and the problem of noise filtering (data smoothing). The system identification and filtering are significant problems for AVHRR data sets. The algorithms outlined in this study can be used for the future EOS missions. Prediction and smoothing algorithms for time series of calibration data provide a functional characterization of the data. Those algorithms can be particularly useful when calibration data are incomplete or sparse.
NASA Astrophysics Data System (ADS)
Baldysz, Zofia; Nykiel, Grzegorz; Araszkiewicz, Andrzej; Figurski, Mariusz; Szafranek, Karolina
2016-09-01
The main purpose of this research was to acquire information about consistency of ZTD (zenith total delay) linear trends and seasonal components between two consecutive GPS reprocessing campaigns. The analysis concerned two sets of the ZTD time series which were estimated during EUREF (Reference Frame Sub-Commission for Europe) EPN (Permanent Network) reprocessing campaigns according to 2008 and 2015 MUT AC (Military University of Technology Analysis Centre) scenarios. Firstly, Lomb-Scargle periodograms were generated for 57 EPN stations to obtain a characterisation of oscillations occurring in the ZTD time series. Then, the values of seasonal components and linear trends were estimated using the LSE (least squares estimation) approach. The Mann-Kendall trend test was also carried out to verify the presence of linear long-term ZTD changes. Finally, differences in seasonal signals and linear trends between these two data sets were investigated. All these analyses were conducted for the ZTD time series of two lengths: a shortened 16-year series and a full 18-year one. In the case of spectral analysis, amplitudes of the annual and semi-annual periods were almost exactly the same for both reprocessing campaigns. Exceptions were found for only a few stations and they did not exceed 1 mm. The estimated trends were also similar. However, for the reprocessing performed in 2008, the trends values were usually higher. In general, shortening of the analysed time period by 2 years resulted in a decrease of the linear trends values of about 0.07 mm yr-1. This was confirmed by analyses based on two data sets.
Trend analysis of long-term temperature time series in the Greater Toronto Area (GTA)
NASA Astrophysics Data System (ADS)
Mohsin, Tanzina; Gough, William A.
2010-08-01
As the majority of the world’s population is living in urban environments, there is growing interest in studying local urban climates. In this paper, for the first time, the long-term trends (31-162 years) of temperature change have been analyzed for the Greater Toronto Area (GTA). Annual and seasonal time series for a number of urban, suburban, and rural weather stations are considered. Non-parametric statistical techniques such as Mann-Kendall test and Theil-Sen slope estimation are used primarily for the assessing of the significance and detection of trends, and the sequential Mann test is used to detect any abrupt climate change. Statistically significant trends for annual mean and minimum temperatures are detected for almost all stations in the GTA. Winter is found to be the most coherent season contributing substantially to the increase in annual minimum temperature. The analyses of the abrupt changes in temperature suggest that the beginning of the increasing trend in Toronto started after the 1920s and then continued to increase to the 1960s. For all stations, there is a significant increase of annual and seasonal (particularly winter) temperatures after the 1980s. In terms of the linkage between urbanization and spatiotemporal thermal patterns, significant linear trends in annual mean and minimum temperature are detected for the period of 1878-1978 for the urban station, Toronto, while for the rural counterparts, the trends are not significant. Also, for all stations in the GTA that are situated in all directions except south of Toronto, substantial temperature change is detected for the periods of 1970-2000 and 1989-2000. It is concluded that the urbanization in the GTA has significantly contributed to the increase of the annual mean temperatures during the past three decades. In addition to urbanization, the influence of local climate, topography, and larger scale warming are incorporated in the analysis of the trends.
NASA Astrophysics Data System (ADS)
Shi, Chunhua; Huang, Ying; Guo, Dong; Zhou, Shunwu; Hu, Kaixi; Liu, Yu
2018-05-01
The South Asian High (SAH) has an important influence on atmospheric circulation and the Asian climate in summer. However, current comparative analyses of the SAH are mostly between reanalysis datasets and there is a lack of sounding data. We therefore compared the climatology, trends and abrupt changes in the SAH in the Japanese 55-year Reanalysis (JRA-55) dataset, the National Centers for Environmental Prediction Climate Forecast System Reanalysis (NCEP-CFSR) dataset, the European Center for Medium-Range Weather Forecasts Reanalysis Interim (ERA-interim) dataset and radiosonde data from China using linear analysis and a sliding t-test. The trends in geopotential height in the control area of the SAH were positive in the JRA-55, NCEP-CFSR and ERA-interim datasets, but negative in the radiosonde data in the time period 1979-2014. The negative trends for the SAH were significant at the 90% confidence level in the radiosonde data from May to September. The positive trends in the NCEP-CFSR dataset were significant at the 90% confidence level in May, July, August and September, but the positive trends in the JRA-55 and ERA-Interim were only significant at the 90% confidence level in September. The reasons for the differences in the trends of the SAH between the radiosonde data and the three reanalysis datasets in the time period 1979-2014 were updates to the sounding systems, changes in instrumentation and improvements in the radiation correction method for calculations around the year 2000. We therefore analyzed the trends in the two time periods of 1979-2000 and 2001-2014 separately. From 1979 to 2000, the negative SAH trends in the radiosonde data mainly agreed with the negative trends in the NCEP-CFSR dataset, but were in contrast with the positive trends in the JRA-55 and ERA-Interim datasets. In 2001-2014, however, the trends in the SAH were positive in all four datasets and most of the trends in the radiosonde and NCEP-CFSR datasets were significant. It is therefore better to use the NCEP-CFSR dataset than the JRA-55 and ERA-Interim datasets when discussing trends in the SAH.
Smith, Kylie J; McNaughton, Sarah A; Cleland, Verity J; Crawford, David; Ball, Kylie
2013-11-01
Breakfast skipping is a potentially modifiable behavior that has negative effects on health and is socioeconomically patterned. This study aimed to examine the intrapersonal (health, behavioral, and cognitive) and social factors associated with breakfast skipping. Nonpregnant women (n = 4123) aged 18-45 y from socioeconomically disadvantaged neighborhoods throughout Victoria, Australia, completed a postal questionnaire. Sociodemographic characteristics, diet, physical activity, sedentary behaviors, and cognitive and social factors were assessed by self-report. Breakfast skipping was defined in 2 ways: 1) "rarely/never" eating breakfast (n = 498) and 2) eating breakfast ≤2 d/wk (includes those who rarely/never ate breakfast; n = 865). Poisson regression was used to calculate prevalence ratios and linear trends, adjusting for covariates. The P values for linear trends are reported below. Compared with breakfast consumers, women who reported rarely/never eating breakfast tended to have poorer self-rated health (P-trend < 0.001), be current smokers (P-trend < 0.001), pay less attention to health (P-trend < 0.001), not prioritize their own healthy eating when busy looking after their family (P-trend < 0.001), have less nutrition knowledge (P-trend < 0.001), and a lower proportion were trying to control their weight (P-trend < 0.020). When breakfast skipping was defined as eating breakfast ≤2 d/wk, additional associations were found for having lower leisure-time physical activity (P-trend = 0.012) and less self-efficacy for eating a healthy diet (P-trend < 0.043). In conclusion, a range of intrapersonal and social factors were significantly associated with breakfast skipping among women living in socioeconomically disadvantaged areas. Acknowledging the cross-sectional design and need for causal confirmation, programs that aim to promote breakfast consumption in this population group should consider targeting family-related barriers to healthy eating and nutrition knowledge.
Geologic and mineral and water resources investigations in western Colorado using ERTS-1 data
NASA Technical Reports Server (NTRS)
Knepper, D. H. (Principal Investigator)
1974-01-01
The author has identified the following significant results. Most of the geologic information in ERTS-1 imagery can be extracted from bulk processed black and white transparencies by a skilled interpreter using standard photogeologic techniques. In central and western Colorado, the detectability of lithologic contacts on ERTS-1 imagery is closely related to the time of year the imagery was acquired. Geologic structures are the most readily extractable type of geologic information contained in ERTS images. Major tectonic features and associated minor structures can be rapidly mapped, allowing the geologic setting of a large region to be quickly accessed. Trends of geologic structures in younger sedimentary appear to strongly parallel linear trends in older metamorphic and igneous basement terrain. Linears and color anomalies mapped from ERTS imagery are closely related to loci of known mineralization in the Colorado mineral belt.
Goode, Daniel J.; Senior, Lisa A.; Subah, Ali; Jaber, Ayman
2013-01-01
Changes in groundwater levels and salinity in six groundwater basins in Jordan were characterized by using linear trends fit to well-monitoring data collected from 1960 to early 2011. On the basis of data for 117 wells, groundwater levels in the six basins were declining, on average about -1 meter per year (m/yr), in 2010. The highest average rate of decline, -1.9 m/yr, occurred in the Jordan Side Valleys basin, and on average no decline occurred in the Hammad basin. The highest rate of decline for an individual well was -9 m/yr. Aquifer saturated thickness, a measure of water storage, was forecast for year 2030 by using linear extrapolation of the groundwater-level trend in 2010. From 30 to 40 percent of the saturated thickness, on average, was forecast to be depleted by 2030. Five percent of the wells evaluated were forecast to have zero saturated thickness by 2030. Electrical conductivity was used as a surrogate for salinity (total dissolved solids). Salinity trends in groundwater were much more variable and less linear than groundwater-level trends. The long-term linear salinity trend at most of the 205 wells evaluated was not increasing, although salinity trends are increasing in some areas. The salinity in about 58 percent of the wells in the Amman-Zarqa basin was substantially increasing, and the salinity in Hammad basin showed a long-term increasing trend. Salinity increases were not always observed in areas with groundwater-level declines. The highest rates of salinity increase were observed in regional discharge areas near groundwater pumping centers.
Jean, Sonia; Hudson, Marie; Gamache, Philippe; Bessette, Louis; Fortin, Paul R; Boire, Gilles; Bernatsky, Sasha
2017-12-01
Health administrative data are a potentially efficient resource to conduct population-based research and surveillance, including trends in incidence and mortality over time. Our objective was to explore time trends in incidence and mortality for rheumatoid arthritis (RA), as well as estimating period prevalence. Our RA case definition was based on one or more hospitalizations with a RA diagnosis code, or three or more RA physician-billing codes, over 2 years, with at least one RA billing code by a rheumatologist, orthopedic surgeon, or internist. To identify incident cases, a "run-in" period of 5 years (1996-2000) was used to exclude prevalent cases. Crude age and sex-specific incidence rates were calculated (using data from 2001 to 2015), and sex-specific incidence rates were also standardized to the 2001 age structure of the Quebec population. We linked the RA cohort (both prevalent and incident patients) to the vital statistics registry, and standardized mortality rate ratios were generated. Negative binomial regression was used to test for linear change in standardized incidence rates and mortality ratios. The linear trends in standardized incidence rates did not show significant change over the study period. Mortality in RA was significantly higher than the general population and this remained true throughout the study period. Our prevalence estimate suggested 0.8% of the Quebec population may be affected by RA. RA incidence appeared relatively stable, and mortality was substantially higher in RA versus the general population and remained so over the study period. This suggests the need to optimize long-term RA outcomes.
Mwagomba, Beatrice; Zachariah, Rony; Massaquoi, Moses; Misindi, Dalitso; Manzi, Marcel; Mandere, Bester C; Bemelmans, Marielle; Philips, Mit; Kamoto, Kelita; Schouten, Eric J; Harries, Anthony D
2010-05-04
To report on the trend in all-cause mortality in a rural district of Malawi that has successfully scaled-up HIV/AIDS care including antiretroviral treatment (ART) to its population, through corroborative evidence from a) registered deaths at traditional authorities (TAs), b) coffin sales and c) church funerals. Retrospective study in 5 of 12 TAs (covering approximately 50% of the population) during the period 2000-2007. A total of 210 villages, 24 coffin workshops and 23 churches were included. There were a total of 18,473 registered deaths at TAs, 15781 coffins sold, and 2762 church funerals. Between 2000 and 2007, there was a highly significant linear downward trend in death rates, sale of coffins and church funerals (X(2) for linear trend: 338.4 P<0.0001, 989 P<0.0001 and 197, P<0.0001 respectively). Using data from TAs as the most reliable source of data on deaths, overall death rate reduction was 37% (95% CI:33-40) for the period. The mean annual incremental death rate reduction was 0.52/1000/year. Death rates decreased over time as the percentage of people living with HIV/AIDS enrolled into care and ART increased. Extrapolating these data to the entire district population, an estimated 10,156 (95% CI: 9786-10259) deaths would have been averted during the 8-year period. Registered deaths at traditional authorities, the sale of coffins and church funerals showed a significant downward trend over a 8-year period which we believe was associated with the scaling up HIV/AIDS care and ART.
Effect of Body Mass Index on Postoperative Transfusions and 24-Hour Chest-Tube Output
Nolan, Heather R.; Ramaiah, Chandrashekhar
2011-01-01
An increasing obese population in the United States focuses attention on the effect of obesity on surgical outcomes. Our objective was to see if obesity, determined by body mass index (BMI), contributed to bleeding in coronary artery bypass graft (CABG) surgery as measured by intraoperative and postoperative packed red blood cell transfusion frequency and amount and 24-hour chest-tube output. A retrospective chart review examined 150 subjects undergoing single-surgeon off-pump or on-pump CABG surgery between September 2006 and April 2009. BMI groups included normal-weight (BMI <25), overweight (BMI 25 to 29), and obese (BMI ≥30). Analyses used a chi-square test to determine variances in number of transfusions, and ANOVA for transfusion amount and 24-hour chest-tube amount. The percentage of subjects receiving intraoperative transfusions varied significantly by BMI group (p = 0.022). The percentage of subjects receiving transfusions in the 72-hour postoperative period showed a decreasing linear trend based on BMI group (p = 0.054). The percentage of subjects receiving transfusions in the combined intraoperative or 72-hour postoperative period showed a decreasing linear trend based on BMI group (p = 0.054). The transfusion amount during the 72-hour postoperative period varied significantly between BMI groups (p = 0.021), and the test for a linear decrease across groups was significant (p = 0.020). Twenty-four hour chest-tube output showed variation across all three BMI categories (p = 0.018) with chest-tube output decreasing with increasing obesity in a linear fashion (p = 0.006). Transfusion rate and amount indicate total blood loss is decreased in the obese, and chest-tube output findings give a direct measurable indicator of blood loss from the surgical site indicating increasing BMI is linearly correlated with decreasing postoperative bleeding. PMID:22654469
Initial Polarimetric Analysis of the Vestoid Asteroid Family
NASA Astrophysics Data System (ADS)
Maleszewski, C.; McMillan, R. S.; Smith, P.
2013-12-01
Observations of polarized light scattered off of asteroid regolith have been used to compare the major asteroid taxonomic types. Members within a taxonomic type tend to have similar polarimetric phase curves (linear polarization vs. phase angle). The polarization also exhibits a wavelength dependence. For the S-complex, the polarization decreases linearly with increasing wavelength. This is different from the C-complex, which has the opposite dependence of polarization on wavelength. The slope of wavelength dependence also changes with phase angle for both complexes; at higher phase angles, the wavelength dependence is steeper. One of the less analyzed taxonomic types with regards to polarization is the V-type. Focus has been placed on the largest member of the V-types: Vesta. However, the Vestoids, which are thought to be collisional remnants of Vesta, have not been analyzed. Due to Vesta's differentiation, the Vestoids as a whole should contain members with significant differences in composition. This in turn should mean significant variations in the polarization observed from these bodies. In order to confirm such differences, we have begun a polarimetric survey of Vestoids. Over thirty observations of six different Vestoids were obtained using the SPOL spectropolarimeter (http://james.as.arizona.edu/~psmith/SPOL/ ) and Steward Observatory telescopes. The wavelength dependence of linear polarization was plotted with respect to the observed phase angle. The linear polarization trends in each of the synthesized B, V, and R bandpasses do not fit a single curve, contrary to that displayed by ensembles of asteroids in other taxonomic complexes. This suggests that these particular targets have dissimilar albedos. This is consistent with the range of albedos measured for the Vestoids through thermal models. However, there is no discernable trend for individual Vestoids with regards to wavelength dependence. Unlike the S- and C-complexes, our data show examples in which the polarization both increases and decreases with wavelength. When our Vestoid data are combined, the wavelength dependence becomes more negative (i.e. polarization tends to decrease with wavelength) as phase angle increases. This is similar to the trend observed in the S-complex, but the opposite trend when compared to the C-complex. The wavelength dependence of Vestoids suggests that this dependence is not strongly affected by albedo. The Vestoids are significantly smaller in size than the asteroids for which other measurements of the wavelength dependence have been analyzed. Possible grain size effects could be a cause of the dissimilar wavelength dependence between the Vestoids and other taxonomic complexes. However, further investigation is needed to explore this possibility.
NASA Astrophysics Data System (ADS)
Kassa, Tsegaye; Tilahun, Samson; Damtie, Baylie
2017-09-01
This paper was aimed at investigating the solar variations of vTEC as a function of solar activity parameters, EUV and F10.7 radio flux. The daily values of ionospheric vertical Total Electron Content (vTEC) were observed using a dual frequency GPS receiver deployed at Bahir Dar (11.6°N and 37.36°E), Ethiopia. Measurements were taken during the period of 2010-2014 for successive five years and analysis was done on only quiet day observations. A quadratic fit was used as a model to describe the daily variation of vTEC in relation to solar parameters. Linear and non-linear coefficients of the vTEC variations were calculated in order to capture the trend of the variation. The variation of vTEC have showed good agreement with the trend of solar parameters in almost all of the days we consider during the period of our observations. We have explicitly observed days with insignificant TECU deviation (eg. modeling with respect to EUV, DOY = 49 in 2010 and modeling with respect to F10.7, DOY = 125 in 2012 and the like) and days with maximum deviation (about 50 TECU). A maximum deviation were observed, on average, during months of equinox whereas minimum during solstice months. This implies that there is a need to consider more parameters, including EUV and F10.7, that can affect the variation of vTEC during equinox seasons. Relatively, small deviations was observed in modeling vTEC as a function of EUV compared to that of the variation due to F10.7 cm flux. This may also tell us that EUV can be more suitable in modeling the solar variation of vTEC especially for longterm trends. Even though, the linear trend of solar variations of vTEC was frequently observed, significant saturation and amplification trends of the solar variations of vTEC were also observed to some extent across the months of the years we have analyzed. This mixed trend of the solar variation of vTEC implies the need for thorough investigation on the effect of solar parameters on TEC. However, based on long-term dataset, we came to conclude that the solar variations of vTEC is dominated by its linear pattern.
Yamani, Nikoo; Changiz, Tahereh; Feizi, Awat; Kamali, Farahnaz
2018-01-01
To assess the trend of changes in the evaluation scores of faculty members and discrepancy between administrators' and students' perspectives in a medical school from 2006 to 2015. This repeated cross-sectional study was conducted on the 10-year evaluation scores of all faculty members of a medical school (n=579) in an urban area of Iran. Data on evaluation scores given by students and administrators and the total of these scores were evaluated. Data were analyzed using descriptive and inferential statistics including linear mixed effect models for repeated measures via the SPSS software. There were statistically significant differences between the students' and administrators' perspectives over time ( p <0.001). The mean of the total evaluation scores also showed a statistically significant change over time ( p <0.001). Furthermore, the mean of changes over time in the total evaluation score between different departments was statistically significant ( p <0.001). The trend of changes in the student's evaluations was clear and positive, but the trend of administrators' evaluation was unclear. Since the evaluation of faculty members is affected by many other factors, there is a need for more future studies.
Statistical approach to the analysis of olive long-term pollen season trends in southern Spain.
García-Mozo, H; Yaezel, L; Oteros, J; Galán, C
2014-03-01
Analysis of long-term airborne pollen counts makes it possible not only to chart pollen-season trends but also to track changing patterns in flowering phenology. Changes in higher plant response over a long interval are considered among the most valuable bioindicators of climate change impact. Phenological-trend models can also provide information regarding crop production and pollen-allergen emission. The interest of this information makes essential the election of the statistical analysis for time series study. We analysed trends and variations in the olive flowering season over a 30-year period (1982-2011) in southern Europe (Córdoba, Spain), focussing on: annual Pollen Index (PI); Pollen Season Start (PSS), Peak Date (PD), Pollen Season End (PSE) and Pollen Season Duration (PSD). Apart from the traditional Linear Regression analysis, a Seasonal-Trend Decomposition procedure based on Loess (STL) and an ARIMA model were performed. Linear regression results indicated a trend toward delayed PSE and earlier PSS and PD, probably influenced by the rise in temperature. These changes are provoking longer flowering periods in the study area. The use of the STL technique provided a clearer picture of phenological behaviour. Data decomposition on pollination dynamics enabled the trend toward an alternate bearing cycle to be distinguished from the influence of other stochastic fluctuations. Results pointed to show a rising trend in pollen production. With a view toward forecasting future phenological trends, ARIMA models were constructed to predict PSD, PSS and PI until 2016. Projections displayed a better goodness of fit than those derived from linear regression. Findings suggest that olive reproductive cycle is changing considerably over the last 30years due to climate change. Further conclusions are that STL improves the effectiveness of traditional linear regression in trend analysis, and ARIMA models can provide reliable trend projections for future years taking into account the internal fluctuations in time series. Copyright © 2013 Elsevier B.V. All rights reserved.
Trend analysis of hydro-climatic variables in the north of Iran
NASA Astrophysics Data System (ADS)
Nikzad Tehrani, E.; Sahour, H.; Booij, M. J.
2018-04-01
Trend analysis of climate variables such as streamflow, precipitation, and temperature provides useful information for understanding the hydrological changes associated with climate change. In this study, a nonparametric Mann-Kendall test was employed to evaluate annual, seasonal, and monthly trends of precipitation and streamflow for the Neka basin in the north of Iran over a 44-year period (1972 to 2015). In addition, the Inverse Distance Weight (IDW) method was used for annual seasonal, monthly, and daily precipitation trends in order to investigate the spatial correlation between precipitation and streamflow trends in the study area. Results showed a downward trend in annual and winter precipitation (Z < -1.96) and an upward trend in annual maximum daily precipitation. Annual and monthly mean flows for most of the months in the Neka basin decreased by 14% significantly, but the annual maximum daily flow increased by 118%. Results for the trend analysis of streamflow and climatic variables showed that there are statistically significant relationships between precipitation and streamflow (p value < 0.05). Correlation coefficients for Kendall, Spearman's rank and linear regression are 0.43, 0.61, and 0.67, respectively. The spatial presentation of the detected precipitation and streamflow trends showed a downward trend for the mean annual precipitation observed in the upstream part of the study area which is consistent with the streamflow trend. Also, there is a good correlation between monthly and seasonal precipitation and streamflow for all sub-basins (Sefidchah, Gelvard, Abelu). In general, from a hydro-climatic point of view, the results showed that the study area is moving towards a situation with more severe drought events.
NASA Technical Reports Server (NTRS)
Merifield, P. M. (Principal Investigator)
1975-01-01
The author has identified the following significant results. Thin sections of rock exposed along the San Diego River linear were prepared and determined to be fault breccia. Single band and ratio images of the western Mojave Desert were prepared from the multispectral scanner digital tapes. Subtle differences in color of soil and rock are enhanced on the ratio images. Two north-northeast trending linears (Horsethief Canyon and Pine Valley Creek) and an east-west linear (Pine Creek) were concluded to have resulted from erosion along well-developed foliation in crystalline basement rocks.
Sisti, Julia S.; Hankinson, Susan E.; Caporaso, Neil E.; Gu, Fangyi; Tamimi, Rulla M.; Rosner, Bernard; Xu, Xia; Ziegler, Regina; Eliassen, A. Heather
2015-01-01
Background Prior studies have found weak inverse associations between breast cancer and caffeine and coffee intake, possibly mediated through their effects on sex hormones. Methods High-performance liquid chromatography/tandem mass spectrometry was used to quantify levels of 15 individual estrogens and estrogen metabolites (EM) among 587 premenopausal women in the Nurses’ Health Study II with mid-luteal phase urine samples and caffeine, coffee and/or tea intakes from self-reported food frequency questionnaires. Multivariate linear mixed models were used to estimate geometric means of individual EM, pathways and ratios by intake categories, and P-values for tests of linear trend. Results Compared to women in the lowest quartile of caffeine consumption, those in the top quartile had higher urinary concentrations of 16α-hydroxyestrone (28% difference; P-trend=0.01) and 16-epiestriol (13% difference; P-trend=0.04), and a decreased parent estrogens/2-, 4-, 16-pathway ratio (P-trend=0.03). Coffee intake was associated with higher 2-catechols, including 2-hydroxyestradiol (57% difference, ≥4 cups/day vs. ≤6 cups/week; P-trend=0.001) and 2-hydroxyestrone (52% difference; P-trend=0.001), and several ratio measures. Decaffeinated coffee was not associated with 2-pathway metabolism, but women in the highest (vs. lowest) category of intake (≥2 cups/day vs. ≤1–3 cups/month) had significantly lower levels of two 16-pathway metabolites, estriol (25% difference; P-trend=0.01) and 17-epiestriol (48% difference; Ptrend=0.0004). Tea intake was positively associated with 17-epiestriol (52% difference; Ptrend=0.01). Conclusion Caffeine and coffee intake were both associated with profiles of estrogen metabolism in premenopausal women. Impact Consumption of caffeine and coffee may alter patterns of premenopausal estrogen metabolism. PMID:26063478
Trends in asthma mortality in young people in southern Brazil.
Chatkin, J M; Barreto, S M; Fonseca, N A; Gutiérrez, C A; Sears, M R
1999-03-01
Mortality from asthma increased and is now declining in some countries, but little is known about these trends in South America. We aimed to assess trends in mortality from asthma in southern Brazil in children and young adults. Death certificates of 425 people in the state of Rio Grande do Sul aged between 5 and 39 years in whom asthma was reported to be the underlying cause of death during the period 1970 to 1992 were reviewed. Population data were available in 10-year age groups. Testing for trends in mortality rates was conducted using linear and log-linear regression procedures. Asthma mortality rates in the age groups 5 to 19 and 20 to 39 years ranged between 0.04 and 0.39/100,000 and 0.28 to 0.75/100,000, respectively, and were nonuniformly distributed over the study period. The mean annual increase in rate in 5- to 19-year olds was +0.01 (95% CI 0.003 to 0.016), an average annual percentage increase of +6.8% (95% CI 3% to 11%), with a total increase of 352% between 1970 and 1992. This increase was not due to a shift in labeling from bronchitis to asthma. In the 20 to 39-year age group, asthma and bronchitis mortality rates showed no trend to increase or decrease. Asthma mortality in southern Brazil is low, but rose significantly between 1970 and 1992 in the 5 to 19-year age group. This trend differs from that found in other states of Brazil and several other Latin American countries. Reasons for this difference remain unclear.
Cohen, Jérémie F; Korevaar, Daniël A; Wang, Junfeng; Leeflang, Mariska M; Bossuyt, Patrick M
2016-09-01
To evaluate changes over time in summary estimates from meta-analyses of diagnostic accuracy studies. We included 48 meta-analyses from 35 MEDLINE-indexed systematic reviews published between September 2011 and January 2012 (743 diagnostic accuracy studies; 344,015 participants). Within each meta-analysis, we ranked studies by publication date. We applied random-effects cumulative meta-analysis to follow how summary estimates of sensitivity and specificity evolved over time. Time trends were assessed by fitting a weighted linear regression model of the summary accuracy estimate against rank of publication. The median of the 48 slopes was -0.02 (-0.08 to 0.03) for sensitivity and -0.01 (-0.03 to 0.03) for specificity. Twelve of 96 (12.5%) time trends in sensitivity or specificity were statistically significant. We found a significant time trend in at least one accuracy measure for 11 of the 48 (23%) meta-analyses. Time trends in summary estimates are relatively frequent in meta-analyses of diagnostic accuracy studies. Results from early meta-analyses of diagnostic accuracy studies should be considered with caution. Copyright © 2016 Elsevier Inc. All rights reserved.
Yang, Jingzhen; Comstock, R Dawn; Yi, Honggang; Harvey, Hosea H; Xun, Pengcheng
2017-12-01
To examine the trends of new and recurrent sports-related concussions in high-school athletes before and after youth sports traumatic brain injury laws. We used an interrupted time-series design and analyzed the concussion data (2005-2016) from High School Reporting Injury Online. We examined the trends of new or recurrent concussion rates among US representative high-school athletes participating in 9 sports across prelaw, immediate-postlaw, and postlaw periods by using general linear models. We defined 1 athlete exposure as attending 1 competition or practice. We included a total of 8043 reported concussions (88.7% new, 11.3% recurrent). The average annual concussion rate was 39.8 per 100 000 athlete exposures. We observed significantly increased trends of reported new and recurrent concussions from the prelaw, through immediate-postlaw, into the postlaw period. However, the recurrent concussion rate showed a significant decline 2.6 years after the laws went into effect. Football exhibited different trends compared with other boys' sports and girls' sports. Observed trends of increased concussion rates are likely attributable to increased identification and reporting. Additional research is needed to evaluate intended long-term impact of traumatic brain injury laws.
NASA Technical Reports Server (NTRS)
Macdonald, H. C.; Grubbs, R. S.
1975-01-01
The most obvious landform features of geologic significance revealed on LANDSAT imagery are linear trends or lineaments. These trends were found to correspond, at least to a large degree, with unmapped faults or complex fracture zones. LANDSAT imagery analysis in northern Arkansas revealed a lineament complex which provides a remarkable correlation with landslide-prone areas along major highway routes. The weathering properties of various rock types, which are considered in designing stable cut slopes and drainage structures, appear to be adversely influenced by the location and trends of LANDSAT defined lineaments. Geologic interpretation of LANDSAT imagery, where applicable and utilized effectively, provides the highway engineer with a tool for predicting and evaluating landslide-prone areas.
Lamsal, Lok N.; Duncan, Bryan N.; Yoshida, Yasuko; ...
2015-06-01
Emissions of nitrogen oxides (NO x) and, subsequently, atmospheric levels of nitrogen dioxide (NO₂) have decreased over the U.S. due to a combination of environmental policies and technological change. Consequently, NO₂ levels have decreased by 30–40% in the last decade. We quantify NO₂ trends (2005–2013) over the U.S. using surface measurements from the U.S. Environmental Protection Agency (EPA) Air Quality System (AQS) and an improved tropospheric NO₂ vertical column density (VCD) data product from the Ozone Monitoring Instrument (OMI) on the Aura satellite.We demonstrate that the current OMI NO₂ algorithm is of sufficient maturity to allow a favorable correspondence ofmore » trends and variations in OMI and AQS data. Our trend model accounts for the non-linear dependence of NO₂ concentration on emissions associated with the seasonal variation of the chemical lifetime, including the change in the amplitude of the seasonal cycle associated with the significant change in NO x emissions that occurred over the last decade. The direct relationship between observations and emissions becomes more robust when one accounts for these non-linear dependencies. We improve the OMI NO₂ standard retrieval algorithm and, subsequently, the data product by using monthly vertical concentration profiles, a required algorithm input, from a high-resolution chemistry and transport model (CTM) simulation with varying emissions (2005-2013). The impact of neglecting the time-dependence of the profiles leads to errors in trend estimation, particularly in regions where emissions have changed substantially. For example, trends calculated from retrievals based on time-dependent profiles offer 18% more instances of significant trends and up to 15% larger total NO₂ reduction versus the results based on profiles for 2005. Using a CTM, we explore the theoretical relation of the trends estimated from NO₂ VCDs to those estimated from ground-level concentrations. The model-simulated trends in VCDs strongly correlate with those estimated from surface concentrations (r = 0.83, N = 355). We then explore the observed correspondence of trends estimated from OMI and AQS data. We find a significant, but slightly weaker, correspondence (i.e., r = 0.68, N = 208) than predicted by the model and discuss some of the important factors affecting the relationship, including known problems (e.g., NO z interferents) associated with the AQS data. This significant correspondence gives confidence in trend and surface concentration estimates from OMI VCDs for locations, such as the majority of the U.S. and globe, that are not covered by surface monitoring networks. Using our improved trend model and our enhanced OMI data product, we find that both OMI and AQS data show substantial downward trends from 2005 to 2013, with an average reduction of 38% for each over the U.S. The annual reduction rates inferred from OMI and AQS measurements are larger (–4.8 ± 1.9%/yr, –3.7 ± 1.5%/yr) from 2005 to 2008 than 2010 to 2013 (–1.2 ± 1.2%/yr, –2.1 ± 1.4%/yr). We quantify NO₂ trends for major U.S. cities and power plants; the latter suggest larger negative trend (–4.0 ± 1.5%/yr) between 2005 and 2008 and smaller or insignificant changes (–0.5 ± 1.2%/yr) during 2010-2013.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lamsal, Lok N.; Duncan, Bryan N.; Yoshida, Yasuko
Emissions of nitrogen oxides (NO x) and, subsequently, atmospheric levels of nitrogen dioxide (NO₂) have decreased over the U.S. due to a combination of environmental policies and technological change. Consequently, NO₂ levels have decreased by 30–40% in the last decade. We quantify NO₂ trends (2005–2013) over the U.S. using surface measurements from the U.S. Environmental Protection Agency (EPA) Air Quality System (AQS) and an improved tropospheric NO₂ vertical column density (VCD) data product from the Ozone Monitoring Instrument (OMI) on the Aura satellite.We demonstrate that the current OMI NO₂ algorithm is of sufficient maturity to allow a favorable correspondence ofmore » trends and variations in OMI and AQS data. Our trend model accounts for the non-linear dependence of NO₂ concentration on emissions associated with the seasonal variation of the chemical lifetime, including the change in the amplitude of the seasonal cycle associated with the significant change in NO x emissions that occurred over the last decade. The direct relationship between observations and emissions becomes more robust when one accounts for these non-linear dependencies. We improve the OMI NO₂ standard retrieval algorithm and, subsequently, the data product by using monthly vertical concentration profiles, a required algorithm input, from a high-resolution chemistry and transport model (CTM) simulation with varying emissions (2005-2013). The impact of neglecting the time-dependence of the profiles leads to errors in trend estimation, particularly in regions where emissions have changed substantially. For example, trends calculated from retrievals based on time-dependent profiles offer 18% more instances of significant trends and up to 15% larger total NO₂ reduction versus the results based on profiles for 2005. Using a CTM, we explore the theoretical relation of the trends estimated from NO₂ VCDs to those estimated from ground-level concentrations. The model-simulated trends in VCDs strongly correlate with those estimated from surface concentrations (r = 0.83, N = 355). We then explore the observed correspondence of trends estimated from OMI and AQS data. We find a significant, but slightly weaker, correspondence (i.e., r = 0.68, N = 208) than predicted by the model and discuss some of the important factors affecting the relationship, including known problems (e.g., NO z interferents) associated with the AQS data. This significant correspondence gives confidence in trend and surface concentration estimates from OMI VCDs for locations, such as the majority of the U.S. and globe, that are not covered by surface monitoring networks. Using our improved trend model and our enhanced OMI data product, we find that both OMI and AQS data show substantial downward trends from 2005 to 2013, with an average reduction of 38% for each over the U.S. The annual reduction rates inferred from OMI and AQS measurements are larger (–4.8 ± 1.9%/yr, –3.7 ± 1.5%/yr) from 2005 to 2008 than 2010 to 2013 (–1.2 ± 1.2%/yr, –2.1 ± 1.4%/yr). We quantify NO₂ trends for major U.S. cities and power plants; the latter suggest larger negative trend (–4.0 ± 1.5%/yr) between 2005 and 2008 and smaller or insignificant changes (–0.5 ± 1.2%/yr) during 2010-2013.« less
Caloric sweetener consumption and dyslipidemia among US adults.
Welsh, Jean A; Sharma, Andrea; Abramson, Jerome L; Vaccarino, Viola; Gillespie, Cathleen; Vos, Miriam B
2010-04-21
Dietary carbohydrates have been associated with dyslipidemia, a lipid profile known to increase cardiovascular disease risk. Added sugars (caloric sweeteners used as ingredients in processed or prepared foods) are an increasing and potentially modifiable component in the US diet. No known studies have examined the association between the consumption of added sugars and lipid measures. To assess the association between consumption of added sugars and blood lipid levels in US adults. Cross-sectional study among US adults (n = 6113) from the National Health and Nutrition Examination Survey (NHANES) 1999-2006. Respondents were grouped by intake of added sugars using limits specified in dietary recommendations (< 5% [reference group], 5%-<10%, 10%-<17.5%, 17.5%-<25%, and > or = 25% of total calories). Linear regression was used to estimate adjusted mean lipid levels. Logistic regression was used to determine adjusted odds ratios of dyslipidemia. Interactions between added sugars and sex were evaluated. Adjusted mean high-density lipoprotein cholesterol (HDL-C), geometric mean triglycerides, and mean low-density lipoprotein cholesterol (LDL-C) levels and adjusted odds ratios of dyslipidemia, including low HDL-C levels (< 40 mg/dL for men; < 50 mg/dL for women), high triglyceride levels (> or = 150 mg/dL), high LDL-C levels (> or = 130 mg/dL), or high ratio of triglycerides to HDL-C (> 3.8). Results were weighted to be representative of the US population. A mean of 15.8% of consumed calories was from added sugars. Among participants consuming less than 5%, 5% to less than 17.5%, 17.5% to less than 25%, and 25% or greater of total energy as added sugars, adjusted mean HDL-C levels were, respectively, 58.7, 57.5, 53.7, 51.0, and 47.7 mg/dL (P < .001 for linear trend), geometric mean triglyceride levels were 105, 102, 111, 113, and 114 mg/dL (P < .001 for linear trend), and LDL-C levels modified by sex were 116, 115, 118, 121, and 123 mg/dL among women (P = .047 for linear trend). There were no significant trends in LDL-C levels among men. Among higher consumers (> or = 10% added sugars) the odds of low HDL-C levels were 50% to more than 300% greater compared with the reference group (< 5% added sugars). In this study, there was a statistically significant correlation between dietary added sugars and blood lipid levels among US adults.
Regional trends for bud burst and flowering of woody plants in Norway as related to climate change
NASA Astrophysics Data System (ADS)
Nordli, Ø.; Wielgolaski, F. E.; Bakken, A. K.; Hjeltnes, S. H.; Måge, F.; Sivle, A.; Skre, O.
2008-09-01
Data series for bud burst, beginning of flowering and petal fall for 20 species of deciduous trees and conifers at four sites in different regions of southern Norway have been analysed and related to temperature series. On average, the spring phenophases occurred 7 days earlier during the period 1971-2005. The most significant linear trends were observed for the earliest phases. The trends in this period were compared with trends in other periods, the longest one starting in 1927. Those starting in cold decades and ending in 2005 were in most instances statistically significant, whereas hardly any significant trend appeared for series starting in warm decades. This fact showed that the results of trend studies are very sensitive to the choice of starting year. There were significant decadal variations in 40% of the series. The dates of occurrence of the phenophases, varying from the first days of May to the first days of June, correlated with seasonal temperature series, in most cases strongest to mean temperatures for the seasons March-May and April-May. The North Atlantic Oscillation Index (NAOI) for January and February appeared to have some predictive power for the date of occurrence of the recorded phases. The basis for this may be that the oscillations described by the index are of importance for the fulfilment of physiological chilling requirements needed to break bud dormancy. The same genotypes of the trees were grown in region West Norway and in Central Norwegian region; during the period 1965-2005 the trends towards earlier bud burst were more pronounced and steeper at the western site.
DOE Office of Scientific and Technical Information (OSTI.GOV)
de Foy, Benjamin; Lu, Zifeng; Streets, David G.
The Ozone Monitoring Instrument (OMI) has been estimating NO2 columns from space for over 10 years, and these have been used to estimate emissions and emission trends for point and area sources all over the world. In this study we evaluate the trends in NO2 columns over 54 cities in the USA and Canada to identify the long term trends due to air quality policies, the impact of the Great Recession, and the weekday-weekend effect. A multiple linear regression model is used to fit annual, seasonal and weekly factors for individual swath retrievals along with the impact of temperature, windmore » speed and pixel size. For most cities, the correlation coefficients of the model fit ranges from 0.47 to 0.76. There have been strong reductions in NO2 columns, with annual decreases of up to 7% per year in most cities. During the years of the Great Recession, NO2 columns were as much as 30% lower than they would have been had they followed the linear annual trend. The analysis yielded insights into the timing of the reductions, with some cities in the northwest and in the east experiencing reductions in 2008 already, and most areas back to where they would have been based on the uniform trend by 2011. The analysis also finds that reductions in columns during the weekend vary significantly from city to city, with a range in reductions of 10%-30% on Saturdays, and 20%-50% on Sundays.« less
Agaku, Israel T; King, Brian A; Dube, Shanta R
2014-01-01
Most tobacco use begins during youth. Thus, this study assessed the prevalence, trends, and correlates of pro-tobacco advertising among United States students in grades 6-12 during 2000-2012. Data from the 2000-2012 National Youth Tobacco Survey were analyzed to assess self-reported exposure to pro-tobacco advertisements through three media: over the Internet, in newspapers/magazines, and at retail stores. Trends during 2000-2012 were assessed in a binary logistic regression model (P<0.05). Among all middle and high school students, the overall prevalence of exposure to Internet pro-tobacco advertisements increased from 22.3% to 43.0% during 2000-2012 (P<0.001 for linear trend). During the same period, declines were observed in the overall prevalence of exposure to pro-tobacco advertisements in newspapers/magazines (65.0% to 36.9%) and at retail stores (87.8% to 76.2%) (P<0.001 for all linear trends). Exposure to pro-tobacco advertisements over the Internet increased significantly during 2000-2012 among United States middle and high school students, while a decline in exposure to advertisements in newspapers or magazines, and at retail stores occurred during the same period. However, over two-thirds of students still reported retail store exposure to pro-tobacco advertisements in 2012. Enhanced and sustained efforts would be beneficial to reduce even more exposure to all forms of pro-tobacco advertisements among youths. © 2013.
NASA Astrophysics Data System (ADS)
Perrone, Loredana; Mikhailov, Andrey; Cesaroni, Claudio; Alfonsi, Lucilla; Santis, Angelo De; Pezzopane, Michael; Scotto, Carlo
2017-09-01
A recently proposed self-consistent approach to the analysis of thermospheric and ionospheric long-term trends has been applied to Rome ionosonde summer noontime observations for the (1957-2015) period. This approach includes: (i) a method to extract ionospheric parameter long-term variations; (ii) a method to retrieve from observed foF1 neutral composition (O, O2, N2), exospheric temperature, Tex and the total solar EUV flux with λ < 1050 Å; and (iii) a combined analysis of the ionospheric and thermospheric parameter long-term variations using the theory of ionospheric F-layer formation. Atomic oxygen, [O] and [O]/[N2] ratio control foF1 and foF2 while neutral temperature, Tex controls hmF2 long-term variations. Noontime foF2 and foF1 long-term variations demonstrate a negative linear trend estimated over the (1962-2010) period which is mainly due to atomic oxygen decrease after ˜1990. A linear trend in (δhmF2)11y estimated over the (1962-2010) period is very small and insignificant reflecting the absence of any significant trend in neutral temperature. The retrieved neutral gas density, ρ atomic oxygen, [O] and exospheric temperature, Tex long-term variations are controlled by solar and geomagnetic activity, i.e. they have a natural origin. The residual trends estimated over the period of ˜5 solar cycles (1957-2015) are very small (<0.5% per decade) and statistically insignificant.
NASA Astrophysics Data System (ADS)
Hasan, Husna; Salleh, Nur Hanim Mohd
2015-10-01
Extreme temperature events affect many human and natural systems. Changes in extreme temperature events can be detected and monitored by developing the indices based on the extreme temperature data. As an effort to provide the understanding of these changes to the public, a study of extreme temperature indices is conducted at five meteorological stations in Peninsular Malaysia. In this study, changes in the means and extreme events of temperature are assessed and compared using the daily maximum and minimum temperature data for the period of 2004 to 2013. The absolute extreme temperature indices; TXx, TXn, TXn and TNn provided by Expert Team on Climate Change Detection and Indices (ETCCDI) are utilized and linear trends of each index are extracted using least square likelihood method. The results indicate that there exist significant decreasing trend in the TXx index for Kota Bharu station and increasing trend in TNn index for Chuping and Kota Kinabalu stations. The comparison between the trend in mean and extreme temperatures show the same significant tendency for Kota Bharu and Kuala Terengganu stations.
Trends in cooling degree-days for five locations in Croatia
NASA Astrophysics Data System (ADS)
Cvitan, L.
2010-09-01
The cooling degree-days (CDD) and number of cooling days (CD) over the period 1901-2008 are analyzed at five stations that represent different climatic regions in Croatia. The stations under consideration are: Osijek in the southern lowland of Pannonian Plain, Zagreb - Grič at the furthest south-eastern edge of the Julian Alps, Gospić in highland - hinterland of the Dinaric Alps, Crikvenica on the north-eastern Adriatic coast and Hvar on the mid - Adriatic island with the same name. Calculation of CDDs and counting of CDs are performed for the 18° C, 21° C and 23° C temperature thresholds that represent daily mean air temperature. Daily mean temperature (M) is calculated by using daily temperatures measured at 7 a.m. (t7), 2 p.m. (t14) and 9 p.m. (t21), in the following way: M=(t7+t14+2t21)/4. Linear trends over the period 1901-2008 are determined for each month as well as for the whole year (annual trend). Statistical significances of the trends are tested using the non-parametric Mann - Kendal test. For the months with the greatest potential cooling demands - June, July and August, the increasing trend is detected for almost all analyzed values at five locations. Namely, only for the August CD (threshold 18° C) for Hvar area and for the June and August CDDs (threshold 23° C) for Gospić area are detected slightly decreasing trends. Most slightly decreasing trends are discovered for September for both parameters at Osijek, Zagreb and Gospić area. Annual trends in both parameters for all locations are increasing, except the annual Gospić CDD (threshold 23° C) trend that is slightly decreasing. According to the Mann - Kendal test neither of the annual trends in CDD and CD for three temperature thresholds are statistically significant at 0.05 significance level in Gospić and Osijek. On the contrary, all of the mentioned annual trends are significant in Zagreb and Crikvenica, and almost all in Hvar (except trends in CD for the 21° C and 23° C thresholds). Months with the significant trends in most of analyzed values are: May and June in Osijek, May, June and July in Zagreb, June in Gospić, June, July and August in Crikvenica and July in Hvar.
NASA Astrophysics Data System (ADS)
Duke, G. I.; Carlson, R. W.
2009-12-01
The fates of subducted oceanic slabs at depth in the mantle are not well known, but linear trends of unusual magmatic products such as kimberlites and carbonatites might be used to track their past existence within the mantle. A N40°W linear trend of kimberlites and carbonatites, and rocks of kimberlitic affinity, from the Black Hills (WY-SD) to Alberta, was suggested to have been caused by upwelling mantle material focused directly above the western edge of the subducted Kula plate stalled in the transition zone, with a slab window or “tear” to the southwest (Duke, 2009). In contrast, a linear zone of similar magmas to the south (a southerly extension of this N40°W linear trend, from Kansas to Louisiana) has been proposed to represent a hot spot trace produced by a mantle plume (“Bermuda Hot Spot”). Ongoing studies of ages and geochemistry of alkalic rocks along the N40°W trend from Louisiana to Alberta provide increasing evidence for a slab-edge model as the cause of the linear trend of kimberlites and carbonatites in the mid-continent. In addition, seismic tomography indicates that the torn Farallon slab currently is stalled in the transition zone below the mid-continent, and an older slab is within the lower mantle farther to the east (Sigloch et al., 2008). These seismic data were interpreted as revealing the presence of the western edge of the Farallon plate trending roughly N40°W. The slab edge as projected to the surface is parallel to, but slightly west of, the trend of kimberlites and carbonatites at the mid-continent. Recently published ages show no clear age progression for the magmatism and thus do not support a hot-spot hypothesis for the linear trend. The isotopic compositions of the alkalic rocks show a genetic similarity among more recent magmas along the trend. There are at least four main pulses of magmatism along the trend at 110-85, 67-64, 55-52, and less than 50 Ma. Kimberlites and carbonatites in the northern section of the N40°W trend are the youngest of the northern group, with ages of ~48 to ≤ 46 Ma. The southern portion of the trend contains the oldest alkalic magmatism in Arkansas, Kansas, and Louisiana, with kimberlites in Kansas and carbonatites in Arkansas. The 67-64 Ma magmatic (or “reheating”) pulse was recorded along the entire trend from Louisiana to northern Montana. Multiple slabs and/or slab segmentation, and irregular convection may account for multiple magmatic pulses, although the 67-64 Ma magmatism across the entire continent is difficult to explain. Importantly, kimberlites and carbonatites represent the most recent, or part of the most recent, magmatism along the N40°W trend. This correlates with a change in proportion of source composition with time, as indicated by increasing positive epsilon Nd and Hf, lower 87Sr/86Sr, and higher 207Pb/204Pb, 206/204Pb, and 208Pb/204Pb. Thus, in each area where there exist precise age and isotopic data, magmatism began with a component that was dominantly lithospheric, followed by increasing proportions of asthenospheric component with time, culminating with kimberlitic or carbonatite magmatism.
Unmetabolized Folic Acid, Tetrahydrofolate, and Colorectal Adenoma Risk.
Rees, Judy R; Morris, Carolyn B; Peacock, Janet L; Ueland, Per M; Barry, Elizabeth L; McKeown-Eyssen, Gail E; Figueiredo, Jane C; Snover, Dale C; Baron, John A
2017-08-01
In a randomized trial of folic acid supplementation for the prevention of colorectal adenomas, we previously found indications of increased risk during later treatment and follow-up. This could have been due to the unmetabolized folic acid (UFA) or natural reduced and methylated folates (mF) to which it is metabolized. In post hoc analyses, we measured mF (the sum of 5-methyl-tetrahydrofolate and 4-alfa-hydroxy-5-methyl-THF) and UFA concentrations in the serum of 924 participants. Using binomial regression models with a log link, we assessed the associations between plasma mF or UFA and adenoma occurrence. We found no association between plasma mF or UFA and overall adenoma risk. However, during later follow-up, the prespecified, composite endpoint of high-risk findings (advanced or multiple adenomas) was positively associated with plasma mF ( P linear trend = 0.009), with a 58% increased risk for participants in the upper versus lowest quartile. An irregular association was seen with plasma UFA, with suggestions of an inverse trend ( P linear trend =0.049). A modest, significant inverse association was also seen between mF and risk of serrated lesions, with a 39% lower risk for upper versus lower quartile participants ( P linear trend = 0.03). In conclusion, during the later follow-up period in which folic acid supplementation was previously seen to increase the risk of advanced and multiple adenomas, higher serum mF was associated with a higher risk of multiple and/or advanced adenomas, but no clear indication that UFA played a direct role. There were indications that higher mF was associated with reduced risk of serrated polyps. Cancer Prev Res; 10(8); 451-8. ©2017 AACR . ©2017 American Association for Cancer Research.
The changes in the frequency of daily precipitation in Urmia Lake basin, Iran
NASA Astrophysics Data System (ADS)
Salehi Bavil, Sepideh; Zeinalzadeh, Kamran; Hessari, Behzad
2017-06-01
Urmia Lake, as one of the most valuable saline ecosystems in the world, has faced a sharp drop in the water level in recent years. The trend studies of climatic parameters can be effective in identifying the responsible factors and managing this crisis. This research investigated the frequency trend of daily precipitation in the ranges of less than 5 mm, 5-10 mm, 10-15 mm, 15-20 mm, and more than 20 mm in the Urmia Lake basin. The trend was assessed using Mann-Kendall, Spearman Rho and linear regression tests on 60 stations during a period of 30 years (1981 to 2011). The results showed that in all the three tests, the frequency of daily precipitation of less than 5 mm had a significant increase at 1% level. The 5-10 mm range displayed no significant trend, while the 10-15 mm range showed a significantly decreasing trend. The frequency in the 15-20 mm and above 20 mm ranges showed an insignificant falling trend. The analysis also indicated jumps in 1996 and 1999 (almost coinciding with the sharp drop in the lake's water level). In other words, the frequency trends of daily precipitation with small amounts (as a result, high evapotranspiration loss) were increasing and with large amounts were decreasing. This can be a contributor to reduced run-off and, hence, decreased water entering the lake. The results emphasize the need for changes in the management and consumption of water resources in the basin, in order to adapt to the climatic change.
How is the weather? Forecasting inpatient glycemic control
Saulnier, George E; Castro, Janna C; Cook, Curtiss B; Thompson, Bithika M
2017-01-01
Aim: Apply methods of damped trend analysis to forecast inpatient glycemic control. Method: Observed and calculated point-of-care blood glucose data trends were determined over 62 weeks. Mean absolute percent error was used to calculate differences between observed and forecasted values. Comparisons were drawn between model results and linear regression forecasting. Results: The forecasted mean glucose trends observed during the first 24 and 48 weeks of projections compared favorably to the results provided by linear regression forecasting. However, in some scenarios, the damped trend method changed inferences compared with linear regression. In all scenarios, mean absolute percent error values remained below the 10% accepted by demand industries. Conclusion: Results indicate that forecasting methods historically applied within demand industries can project future inpatient glycemic control. Additional study is needed to determine if forecasting is useful in the analyses of other glucometric parameters and, if so, how to apply the techniques to quality improvement. PMID:29134125
Short-term Aerosol Trends: Reality or Myth?
NASA Technical Reports Server (NTRS)
Leptoukh, Gregory; Zubko, Viktor
2009-01-01
The main questions addressed in this slide presentation involve short-term trends of MODIS aerosol optical thickness (AOT) over 6 years: (1) Why are the trends different in different regions? (2) How are these trends so high? (3) Why are they "coherent" in many areas? (4) Are these changes in aerosol concentrations real, i.e., are they monotonic changes in emissions? Several views of the Spatial Distribution of AOT from Terra are shown. In conclusion there are several trends: (1) There is a broad spatial inhomogenueity in AOT trends over 6 years of MODIS Terra and Aqua (2) Some of the areas demonstrate clear positive trends related to increase of emission (e.g., Eastern China) (3) Strong trends in some other areas are superficial and might be attributed, in part, to: (3a) Least squares linear trend sensitivity to outliers (need to use more robust linear fitting method) (3b) Spatial and temporal shifts or trends in meteorological conditions, especially in wind patterns responsible for aerosol transport (6) Aerosol trends should be studied together with changes in meteorology patterns as they might closely linked together
Gardiner, Roisin; Roshan, Davood; Brennan, Ann; Connolly, Denise; Murray, Susan; Reddan, Donal
2018-04-27
Anaemia among haemodialysis patients is treated with iron and erythropoietin-stimulating agents (ESAs). ESAs reduce requirements for blood transfusions but are also expensive and overzealous use may be associated with adverse outcomes. Recent international trends have been characterised by reduced ESA doses and a greater reliance on intravenous (IV) iron. We determined trends in prescribing patterns of ESAs and IV iron for the treatment of anaemia in two representative Irish dialysis centres and correlated with current guidelines and international trends. Patient data was accessed from the Kidney Disease Clinical Patient Management System (KDCPMS) for the period 2012 to 2014. We generated reports on ESA and iron doses, lab data (haemoglobin (Hb), transferrin saturation (TSAT) and ferritin) and patient population characteristics. We mapped the trends in ESA, iron dosing and lab parameters achieved. A linear mixed model determined the significance of these trends over time. ESA dosing became lower in the second, third and fourth quarters of 2014. Dosing of iron increased throughout but a large increase was seen in the third and fourth quarters of 2014. Ferritin levels decreased and TSAT and haemoglobin levels increased. Changes in iron dosing were significant with p value of < 0.05. Our findings are consistent with recent global trends toward increasing iron use. Such trends may have economic implications given the high cost of ESAs and the relative affordability of iron. In addition, the potential harm of excessive iron dosing may need to be considered.
Leung, Cindy W.; Leak, Tashara M.; Laraia, Barbara A.
2017-01-01
Introduction Whole-grain consumption reduces risk of chronic disease, yet adolescents consume suboptimal amounts. It is unclear whether trends in consumption of whole grains have been positive among adolescents, and research assessing disparities by socioeconomic status is limited. The objective of our study was to evaluate recent trends in whole-grain consumption by US adolescents. Methods We examined data on 3,265 adolescents aged 13 to18 years from the National Health and Nutrition Examination Survey (NHANES) 2005–2012. Intake of whole and refined grains was analyzed by using generalized linear models, and odds of no whole-grain intake were examined with logistic regression, adjusting for socioeconomic and demographic factors. We evaluated trends and examined heterogeneity of trends with respect to annual household income. Results Daily whole-grain consumption among adolescents increased overall by about a quarter-ounce–equivalent per day (oz-eq/d) (P trend <.001). We found a significant relationship between whole-grain intake and income. Daily whole grains (recommended as ≥3 oz-eq/d), increased (0.6 to 1.0 oz-eq/d) among high-income adolescents (P trend < .001) but remained at 0.5 oz-eq/d for low-income adolescents. The ratio of whole grains to total grains (recommended to be at least 50%) rose from 7.6% to 14.2% for high-income adolescents (P trend < .001), with no significant trend for the low-income group. Consumption of refined grains did not change. Odds of having no whole grains trended downward, but only for the high-income adolescents (P trend = .01). Conclusion These data show significant (albeit modest) trends toward increased intake of whole grains among high-income adolescents nationwide that are absent among low-income peers. Future interventions and policies should address barriers to whole-grain consumption among this vulnerable group. PMID:28682743
Tester, June M; Leung, Cindy W; Leak, Tashara M; Laraia, Barbara A
2017-07-06
Whole-grain consumption reduces risk of chronic disease, yet adolescents consume suboptimal amounts. It is unclear whether trends in consumption of whole grains have been positive among adolescents, and research assessing disparities by socioeconomic status is limited. The objective of our study was to evaluate recent trends in whole-grain consumption by US adolescents. We examined data on 3,265 adolescents aged 13 to18 years from the National Health and Nutrition Examination Survey (NHANES) 2005-2012. Intake of whole and refined grains was analyzed by using generalized linear models, and odds of no whole-grain intake were examined with logistic regression, adjusting for socioeconomic and demographic factors. We evaluated trends and examined heterogeneity of trends with respect to annual household income. Daily whole-grain consumption among adolescents increased overall by about a quarter-ounce-equivalent per day (oz-eq/d) (P trend <.001). We found a significant relationship between whole-grain intake and income. Daily whole grains (recommended as ≥3 oz-eq/d), increased (0.6 to 1.0 oz-eq/d) among high-income adolescents (P trend < .001) but remained at 0.5 oz-eq/d for low-income adolescents. The ratio of whole grains to total grains (recommended to be at least 50%) rose from 7.6% to 14.2% for high-income adolescents (P trend < .001), with no significant trend for the low-income group. Consumption of refined grains did not change. Odds of having no whole grains trended downward, but only for the high-income adolescents (P trend = .01). These data show significant (albeit modest) trends toward increased intake of whole grains among high-income adolescents nationwide that are absent among low-income peers. Future interventions and policies should address barriers to whole-grain consumption among this vulnerable group.
Karimi, Mehrdad; Kabir, Ali; Nejatifar, Masoumeh; Pazouki, Abdolreza
2018-03-01
The aim of this study is to investigate the pattern of changes in serum albumin level after mini-gastric bypass (MGB) and its association with gender, age, and body mass index (BMI) of the patients. This cohort study was conducted on 196 morbidly obese patients undergoing MGB followed for 1 year. The data on BMI, serum albumin level, demographic, anthropometric, biochemical variables and comorbidities were gathered before and after (3, 6, and 12 months) surgery. The trend of changes in BMI and serum albumin of the patients was investigated by repeated measures tests using general linear model (GLM) and generalized estimating equations (GEE) approaches. The mean age, baseline median BMI, and albumin of the patients were 41.34 ± 11.03 years, 44.54 kg/m 2 , and 4.00 g/dl, respectively. There was a chronologically significant trend of decline in BMI (P < 0.001). GEE demonstrated no chronologically significant trend in serum albumin (P = 0.278). The trend of changes in albumin was significantly associated only with age grouping and baseline serum albumin level (P = 0.017 and 0.001, respectively). This trend had fluctuations in patients older than 40 years with baseline serum albumin level of 3.50-3.90 g/dl. For patients with any age and baseline serum albumin level of 4.00-4.90 g/dl, this trend was stable in all periods of follow-up. MGB is an effective technique to lose weight. The trend of changes in serum albumin level was affected by its baseline levels and age.
Stratospheric Ozone Trends and Variability as Seen by SCIAMACHY from 2002 to 2012
NASA Technical Reports Server (NTRS)
Gebhardt, C.; Rozanov, A.; Hommel, R.; Weber, M.; Bovensmann, H.; Burrows, J. P.; Degenstein, D.; Froidevaux, L.; Thompson, A. M.
2014-01-01
Vertical profiles of the rate of linear change (trend) in the altitude range 15-50 km are determined from decadal O3 time series obtained from SCIAMACHY/ENVISAT measurements in limb-viewing geometry. The trends are calculated by using a multivariate linear regression. Seasonal variations, the quasi-biennial oscillation, signatures of the solar cycle and the El Nino-Southern Oscillation are accounted for in the regression. The time range of trend calculation is August 2002-April 2012. A focus for analysis are the zonal bands of 20 deg N - 20 deg S (tropics), 60 - 50 deg N, and 50 - 60 deg S (midlatitudes). In the tropics, positive trends of up to 5% per decade between 20 and 30 km and negative trends of up to 10% per decade between 30 and 38 km are identified. Positive O3 trends of around 5% per decade are found in the upper stratosphere in the tropics and at midlatitudes. Comparisons between SCIAMACHY and EOS MLS show reasonable agreement both in the tropics and at midlatitudes for most altitudes. In the tropics, measurements from OSIRIS/Odin and SHADOZ are also analysed. These yield rates of linear change of O3 similar to those from SCIAMACHY. However, the trends from SCIAMACHY near 34 km in the tropics are larger than MLS and OSIRIS by a factor of around two.
NASA Technical Reports Server (NTRS)
Entzian, G.; Grasnick, K. H.; Taubenheim, J.
1989-01-01
The long term trends (least square linear regression with time) of ozone content at seven European, seven North American, three Japanese and two tropical stations during 21 years (1964 to 1984) are analyzed. In all regions negative trends are observed during the 1970s, but are partly compensated by limited periods of positive trends during the late 1960s and late 1970s. Solely the North American ozone data show negative trends in all 10 year periods. When the long term ozone trends are evaluated for each month of the year separately, a seasonal variation is revealed, which in Europe and North America has largest negative trends in late winter and spring. While in Europe the negative trends in winter/spring are partly compensated by positive trends in summer, in North America the summer values reach only zero, retaining the significant negative trend in annual mean values. In contrast to the antarctic ozone hole, the spring reduction of ozone in Europe and in North America is associated with stratospheric temperatures increasing in the analyzed period and therefore is consistent with the major natural ozone production and loss processes.
NASA Astrophysics Data System (ADS)
Lan, X.; Tans, P. P.; Sweeney, C.; Andrews, A. E.; Dlugokencky, E. J.; Lang, P. M.; Crotwell, M.; Miller, B.; Kofler, J.; Newberger, T.; McKain, K.; Wolter, S.; Montzka, S. A.
2016-12-01
Recent studies on whether methane (CH4) emissions from oil and natural gas (ONG) operations in the U.S. have increased are still inconclusive. To provide observational evidence we carefully analyzed the in-situ CH4 measurements from the NOAA/ESRL Global Greenhouse Gas Reference Network (GGGRN) for the best estimates of CH4 trends for 2006-2016. Methane data from more than 20 surface and aircraft sites across the U.S. were included in this study. Variations of sampling frequencies in different seasons were taken into account for accurate trend detection. Correlations among measurements within short sampling intervals were also considered for uncertainty estimates. We found that most of our sites had similar CH4 trends of 6 ppb/yr, which was comparable with the recent global background CH4 trend. Substantially higher growth rates were found at the Southern Great Plain site in Oklahoma (SGP, downwind of the Eagle Ford, Barnett Shale and Woodford ONG fields) and the Dahlen sites in North Dakota (DND, downwind of the Bakken ONG field), which indicated influences from regional ONG activities. Ethane (C2H6) measurements from SGP (C2H6 measurements were not available from DND) and propane (C3H8) measurements from both SPG and DND exhibited significant increasing trends, while trends at other sites were either non-significant (trend < 2*S.D.) or only marginally significant. Linear correlations were well identified for surface C3H8 and CH4 enhancements at these two sites, relative to observations at higher altitudes. However, by applying the observed enhancement ratios of surface C3H8 /CH4 and the C3H8 trends (as indicator for ONG emissions) on CH4 trend estimates, we would infer much larger surface CH4 trends than what we actually observed at these two sites. This discrepancy suggests that using enhancement ratios of C3H8 /CH4 is not likely a reliable approach to compute CH4 emission trends.
On the Observed Changes in Upper Stratospheric and Mesospheric Temperatures from UARS HALOE
NASA Technical Reports Server (NTRS)
Remsberg, Ellis E.
2006-01-01
Temperature versus pressure or T(p) time series from the Halogen Occultation Experiment (HALOE) on the Upper Atmosphere Research Satellite (UARS) have been extended and re-analyzed for the period of 1991-2005 and for the upper stratosphere and mesosphere in 10-degree wide latitude zones from 60S to 60N. Even though sampling from a solar occultation experiment is somewhat limited, it is shown to be quite adequate for developing both the seasonal and longer-term variations in T(p). Multiple linear regression (MLR) techniques were used in the re-analyses for the seasonal and the significant interannual, solar cycle (SC-like or decadal-scale), and linear trend terms. A simple SC-like term of 11-yr period was fitted to the time series residuals after accounting for the seasonal and interannual terms. Highly significant SC-like responses were found for both the upper mesosphere and the upper stratosphere. The phases of these SC-like terms were checked for their continuity with latitude and pressure-altitude, and in almost all cases they are directly in-phase with that of standard proxies for the solar flux variations. The analyzed, max minus min, responses at low latitudes are of order 1 K, while at middle latitudes they are as large as 3 K in the upper mesosphere. Highly significant, linear cooling trends were found at middle latitudes of the middle to upper mesosphere (about -2 K/decade), at tropical latitudes of the middle mesosphere (about -1 K/decade), and at 2 hPa (or order -1 K/decade).
Evans-Lacko, Sara; Corker, Elizabeth; Williams, Paul; Henderson, Claire; Thornicroft, Graham
2014-07-01
Understanding trends and effective mechanisms that are likely to reduce public stigma and discrimination towards people with mental illness is important. We aimed to assess changes in public stigma in England after the introduction of the Time to Change anti-stigma campaign. We used data from the 2003 and 2007-13 national Attitudes to Mental Illness surveys to investigate 10-year trends in public attitudes across England before and during the Time to Change anti-stigma campaign. We present annual mean scores for attitude items related to prejudice and exclusion, and tolerance and support for community care. We also present an extrapolated linear trend line for the years 2009-13 and estimate population attitude scores without the campaign. We present unadjusted and adjusted linear regression models. In addition, we used multivariable linear regression models fitted to data aggregated by region to investigate whether a dose-effect response exists between campaign awareness and regional outcomes related to knowledge, attitudes, and intended behaviour. About 1700 respondents were surveyed each year. Significant increases in positive attitudes related to prejudice and exclusion occurred after the Time to Change campaign. In the multivariable analysis, we noted a significant increase in positive attitudes in relation to prejudice and exclusion after the launch of Time to Change (reverse-coded Z score 0·02, 95% CI 0·01 to 0·05; p=0·01), but not for tolerance and support for community care (Z score 0·01, -0·01 to 0·03; p=0·27). We also found evidence for a dose-effect relation between campaign awareness and regional improvement in knowledge (p=0·004) and attitudes (tolerance and support p<0·0001; prejudice and exclusion p=0·001), but not intended behaviour (p=0·20). The positive effects of Time to Change seem to be significant and moderate. Although attitudes are probably more at risk of deterioration during times of economic hardship, anti-stigma programmes might still play an active part in long-term reduction of stigma and discrimination, especially in relation to prejudice and exclusion of people with mental health problems. UK Department of Health, Comic Relief, Big Lottery. Copyright © 2014 Elsevier Ltd. All rights reserved.
NASA Technical Reports Server (NTRS)
Hoppin, R. A. (Principal Investigator)
1974-01-01
The author has identified the following significant results. Analysis of SL-3, S-190A, and S-190B color frames indicates two sets of linears obliquely cutting across the east-west trending Owl Creek-Bridger uplifts. A northwest set of faults and folds has been mapped previously but the imagery indicates some changes and addition of detail can be made. A less pronounced east-northeast set of linear alignments (drainage segments, lithologic contacts, possible faults) extends into the southeast part of the Big Horn Basin.
The linear trend of headache prevalence and some headache features in school children.
Ozge, Aynur; Buğdayci, Resul; Saşmaz, Tayyar; Kaleağasi, Hakan; Kurt, Oner; Karakelle, Ali; Siva, Aksel
2007-04-01
The objectives of this study were to determine the age and sex dependent linear trend of recurrent headache prevalence in schoolchildren in Mersin. A stratified sample composed of 5562 children; detailed characteristics were previously published. In this study the prevalence distribution of headache by age and sex showed a peak in the female population at the age of 11 (27.2%) with a plateau in the following years. The great stratified random sample results suggested that, in addition to socio-demographic features, detailed linear trend analysis showed headache features of children with headache have some specific characteristics dependent on age, gender and headache type. This study results can constitute a basis for the future epidemiological based studies.
Caroli, A; Frisoni, G B
2010-08-01
The aim of this study was to investigate the dynamics of four of the most validated biomarkers for Alzheimer's disease (AD), cerebro-spinal fluid (CSF) Abeta 1-42, tau, hippocampal volume, and FDG-PET, in patients at different stage of AD. Two hundred twenty-nine cognitively healthy subjects, 154 mild cognitive impairment (MCI) patients converted to AD, and 193 (95 early and 98 late) AD patients were selected from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database. For each biomarker, individual values were Z-transformed and plotted against ADAS-cog scores, and sigmoid and linear fits were compared. For most biomarkers the sigmoid model fitted data significantly better than the linear model. Abeta 1-42 time course followed a steep curve, stabilizing early in the disease course. CSF tau and hippocampal volume changed later showing similar monotonous trends, reflecting disease progression. Hippocampal loss trend was steeper and occurred earlier in time in APOE epsilon4 carriers than in non-carriers. FDG-PET started changing early in time and likely followed a linear decline. In conclusion, this study provides the first evidence in favor of the dynamic biomarker model which has recently been proposed. 2010 Elsevier Inc. All rights reserved.
Mercado, Carla I; Gregg, Edward; Gillespie, Cathleen; Loustalot, Fleetwood
2018-01-01
With a cholesterol-lowering focus for diabetic adults and in the age of polypharmacy, it is important to understand how lipid profile levels differ among those with and without diabetes. Investigate the means, differences, and trends in lipid profile measures [TC, total cholesterol; LDL-c, low-density lipoprotein; HDL-c, high-density lipoprotein; and TG, triglycerides] among US adults by diabetes status and cholesterol-lowering medication. Population number and proportion of adults aged ≥21 years with diabetes and taking cholesterol-lowering medication were estimated using data on 10,384 participants from NHANES 2003-2012. Age-standardized means, trends, and differences in lipid profile measures were estimated by diabetes status and cholesterol medication use. For trends and differences, linear regression analysis were used adjusted for age, gender, and race/ethnicity. Among diabetic adults, 52% were taking cholesterol-lowering medication compared to the 14% taking cholesterol-lowering medication without diabetes. Although diabetic adults had significantly lower TC and LDL-c levels than non-diabetic adults [% difference (95% confidence interval): TC = -5.2% (-6.8 --3.5), LDL-c = -8.0% (-10.4 --5.5)], the percent difference was greater among adults taking cholesterol medication [TC = -8.0% (-10.3 --5.7); LDL-c = -13.7% (-17.1 --10.2)] than adults not taking cholesterol medication [TC = -3.5% (-5.2 --1.6); LDL-c = -4.3% (-7.1 --1.5)] (interaction p-value: TC = <0.001; LDL-c = <0.001). From 2003-2012, mean TC and HDL-c significantly decreased among diabetic adults taking cholesterol medication [% difference per survey cycle (p-value for linear trend): TC = -2.3% (0.003) and HDL-c = -2.3% (0.033)]. Mean TC, HDL-c, and LDL-c levels did not significantly change from 2003 to 2012 in non-diabetic adults taking cholesterol medication or for adults not taking cholesterol medications. Diabetic adults were more likely to have lower lipid levels, except for triglyceride levels, than non-diabetic adults with profound differences when considering cholesterol medication use, possibly due to the positive effects from clinical diabetes management.
CHIPPING FRACTURE RESISTANCE OF DENTURE TOOTH MATERIALS
Quinn, G. D.; Giuseppetti, A. A.; Hoffman, K. H.
2014-01-01
Objective The applicability of the edge chipping method to denture tooth materials was assessed. These are softer materials than those usually tested by edge chipping. The edge chipping fracture resistances of polymethylmethacrylate (PMMA) based and two filled resin composite denture tooth materials were compared. Methods An edge chipping machine was used to chip rectangular blocks and flattened anterior denture teeth. Force versus edge distance data were collected over a broad range of forces and distances. Between 20 and 65 chips were made per condition depending upon the material, the scatter, and the indenter type. Different indenter types were used including Rockwell C, sharp conical 120°, Knoop, and Vickers. The edge toughness, Te, was evaluated for different indenter types. Results The edge chipping data collected on the blocks matched the data collected from flattened teeth. High scatter, particularly at large distances and loads, meant that many tests (up to 64) were necessary to compare the denture tooth materials and to ascertain the appropriate data trends. A linear force – distance trend analysis was adequate for comparing these materials. A power law trend might be more appropriate, but the large scatter obscured the definitive determination of the precise trend. Different indenters produce different linear trends, with the ranking of: sharp conical 120°, Rockwell C, and Knoop, from lowest to highest edge toughness. Vickers indenter data were extremely scattered and a sensible trend could not be obtained. Edge toughness was inversely correlated to hardness. Significance Edge chipping data collected either from simple laboratory scale test blocks or from actual denture teeth may be used to evaluate denture materials. The edge chipping method’s applicability has been extended to another class of restorative materials. PMID:24674342
Outcome Trends after US Military Concussive Traumatic Brain Injury.
Mac Donald, Christine L; Johnson, Ann M; Wierzechowski, Linda; Kassner, Elizabeth; Stewart, Theresa; Nelson, Elliot C; Werner, Nicole J; Adam, Octavian R; Rivet, Dennis J; Flaherty, Stephen F; Oh, John S; Zonies, David; Fang, Raymond; Brody, David L
2017-07-15
Care for US military personnel with combat-related concussive traumatic brain injury (TBI) has substantially changed in recent years, yet trends in clinical outcomes remain largely unknown. Our prospective longitudinal studies of US military personnel with concussive TBI from 2008-2013 at Landstuhl Regional Medical Center in Germany and twp sites in Afghanistan provided an opportunity to assess for changes in outcomes over time and analyze correlates of overall disability. We enrolled 321 active-duty US military personnel who sustained concussive TBI in theater and 254 military controls. We prospectively assessed clinical outcomes 6-12 months later in 199 with concussive TBI and 148 controls. Global disability, neurobehavioral impairment, depression severity, and post-traumatic stress disorder (PTSD) severity were worse in concussive TBI groups in comparison with controls in all cohorts. Global disability primarily reflected a combination of work-related and nonwork-related disability. There was a modest but statistically significant trend toward less PTSD in later cohorts. Specifically, there was a decrease of 5.9 points of 136 possible on the Clinician Administered PTSD Scale (-4.3%) per year (95% confidence interval, 2.8-9.0 points, p = 0.0037 linear regression, p = 0.03 including covariates in generalized linear model). No other significant trends in outcomes were found. Global disability was more common in those with TBI, those evacuated from theater, and those with more severe depression and PTSD. Disability was not significantly related to neuropsychological performance, age, education, self-reported sleep deprivation, injury mechanism, or date of enrollment. Thus, across multiple cohorts of US military personnel with combat-related concussion, 6-12 month outcomes have improved only modestly and are often poor. Future focus on early depression and PTSD after concussive TBI appears warranted. Adverse outcomes are incompletely explained, however, and additional studies with prospective collection of data on acute injury severity and polytrauma, as well as reduced attrition before follow-up will be required to fully address the root causes of persistent disability after wartime injury.
Chiang, Ho-Sheng; Huang, Ren-Yeong; Weng, Pei-Wei; Mau, Lian-Ping; Su, Chi-Chun; Tsai, Yi-Wen Cathy; Wu, Yu-Chiao; Chung, Chi-Hsiang; Shieh, Yi-Shing; Cheng, Wan-Chien
To identify 100 top-cited articles published in periodontal journals and analyse the research trends by using citation analysis. 100 top-cited articles published in periodontal journals were retrieved by searching the database of the ISI Web of Science and Journal Citation reports. For each article, the following principal bibliometric parameters: authorship, geographic and institute origin, manuscript type, study design, scope of study, and citation count of each time period were analysed from 1965 to 2015. The identified 100 top-cited articles were retrieved from five periodontal journals and citation counts were recorded between 262 and 1,693 times. For the institute of origin, the most productive institute, in terms of the number of 100 top-cited articles published, was the University of Gothenburg (Sweden) (n = 19), followed by the Forsyth Dental Center (USA) (n = 15). Most manuscripts were original research (n = 74), and the inflammatory periodontal disease (n = 59) was the most frequent topic studied. Interestingly, the trend of increase average citation reached significance for implantology (β = 26.75, P = 0.003) and systemic interactions (β = 29.83, P = 0.005), but not for inflammatory disease (β = -10.30, P = 0.248) and tissue regeneration (β = 9.04, P = 0.081). By using multivariable linear regression in a generalised linear model, suitable published journal (Journal of Clinical Periodontology), geographic regions (Europe), more intense international collaboration, adequate manuscript type (review article) and study design (systematic review) could be attributed to escalating average citation counts in implantology (all P < 0.05). However, for systemic interactions, only geographic region and study design were significantly associated with the increasing citation trend. These principal bibliometric characteristics revealed escalated trends in average citation count in implantology throughout time. Conflict-of-interest statement The authors have stated explicitly that there are no conflicts of interest in connection with this article. The study was self-funded by the authors and their institution.
Schulz, Marcus; Neumann, Daniel; Fleet, David M; Matthies, Michael
2013-12-01
During the last decades, marine pollution with anthropogenic litter has become a worldwide major environmental concern. Standardized monitoring of litter since 2001 on 78 beaches selected within the framework of the Convention for the Protection of the Marine Environment of the North-East Atlantic (OSPAR) has been used to identify temporal trends of marine litter. Based on statistical analyses of this dataset a two-part multi-criteria evaluation system for beach litter pollution of the North-East Atlantic and the North Sea is proposed. Canonical correlation analyses, linear regression analyses, and non-parametric analyses of variance were used to identify different temporal trends. A classification of beaches was derived from cluster analyses and served to define different states of beach quality according to abundances of 17 input variables. The evaluation system is easily applicable and relies on the above-mentioned classification and on significant temporal trends implied by significant rank correlations. Copyright © 2013 Elsevier Ltd. All rights reserved.
Bhushan, Abhinav; Leigh, J Paul
2011-01-01
Numbers and costs of occupational injuries and illnesses are significant in terms of morbidity and dollars, yet our understanding of time trends is minimal. We investigated trends and addressed some common hypotheses regarding causes of fluctuations. We pulled data on incidence rates (per 100 full-time employed workers) for injuries and illnesses from the U.S. Bureau of Labor Statistics and on costs and benefits from the National Academy of Social Insurance for 1973 through 2007. Rates reflected all injury and illness cases, lost work-time cases, and cases resulting in at least 31 days away from work. We adjusted dollar costs (premiums) and benefits for inflation and measured them per employed worker. We plotted data in time-trend charts and ran linear regressions. From 1973 to 1991, there was a weak to nonexistent downward trend for injury and illness rates, and rates were strongly and negatively correlated with the unemployment rate. From 1992 to 2007, there were strong, consistent downward trends, but no longer were there statistically significant correlations with unemployment. Significant predictors (and signs) of workers' compensation premiums for 1973-2007 included medical price inflation (positive), number of lost-time injuries (positive), the Dow Jones Industrial Average (negative), and inflation-adjusted interest rate on U.S. Treasury bonds (negative). Dollars of benefits were positively and significantly predicted by medical inflation and number of lost-time cases. For 1992-2007, the Dow Jones variable was the only robust predictor of premiums; the number of injuries was not a significant positive predictor. We had two major conclusions. First, the year 1992 marked a sharp contrast in trends and correlations between unemployment and incidence rates for occupational injuries and illnesses. Second, for the entire time period (1973-2007), insurance carriers' premiums were strongly associated with returns on investments.
Bhushan, Abhinav; Leigh, J. Paul
2011-01-01
Objective Numbers and costs of occupational injuries and illnesses are significant in terms of morbidity and dollars, yet our understanding of time trends is minimal. We investigated trends and addressed some common hypotheses regarding causes of fluctuations. Methods We pulled data on incidence rates (per 100 full-time employed workers) for injuries and illnesses from the U.S. Bureau of Labor Statistics and on costs and benefits from the National Academy of Social Insurance for 1973 through 2007. Rates reflected all injury and illness cases, lost work-time cases, and cases resulting in at least 31 days away from work. We adjusted dollar costs (premiums) and benefits for inflation and measured them per employed worker. We plotted data in time-trend charts and ran linear regressions. Results From 1973 to 1991, there was a weak to nonexistent downward trend for injury and illness rates, and rates were strongly and negatively correlated with the unemployment rate. From 1992 to 2007, there were strong, consistent downward trends, but no longer were there statistically significant correlations with unemployment. Significant predictors (and signs) of workers' compensation premiums for 1973–2007 included medical price inflation (positive), number of lost-time injuries (positive), the Dow Jones Industrial Average (negative), and inflation-adjusted interest rate on U.S. Treasury bonds (negative). Dollars of benefits were positively and significantly predicted by medical inflation and number of lost-time cases. For 1992–2007, the Dow Jones variable was the only robust predictor of premiums; the number of injuries was not a significant positive predictor. Conclusion We had two major conclusions. First, the year 1992 marked a sharp contrast in trends and correlations between unemployment and incidence rates for occupational injuries and illnesses. Second, for the entire time period (1973–2007), insurance carriers' premiums were strongly associated with returns on investments. PMID:21886322
NASA Astrophysics Data System (ADS)
Keeble, James; Brown, Hannah; Abraham, N. Luke; Harris, Neil R. P.; Pyle, John A.
2018-06-01
Total column ozone values from an ensemble of UM-UKCA model simulations are examined to investigate different definitions of progress on the road to ozone recovery. The impacts of modelled internal atmospheric variability are accounted for by applying a multiple linear regression model to modelled total column ozone values, and ozone trend analysis is performed on the resulting ozone residuals. Three definitions of recovery are investigated: (i) a slowed rate of decline and the date of minimum column ozone, (ii) the identification of significant positive trends and (iii) a return to historic values. A return to past thresholds is the last state to be achieved. Minimum column ozone values, averaged from 60° S to 60° N, occur between 1990 and 1995 for each ensemble member, driven in part by the solar minimum conditions during the 1990s. When natural cycles are accounted for, identification of the year of minimum ozone in the resulting ozone residuals is uncertain, with minimum values for each ensemble member occurring at different times between 1992 and 2000. As a result of this large variability, identification of the date of minimum ozone constitutes a poor measure of ozone recovery. Trends for the 2000-2017 period are positive at most latitudes and are statistically significant in the mid-latitudes in both hemispheres when natural cycles are accounted for. This significance results largely from the large sample size of the multi-member ensemble. Significant trends cannot be identified by 2017 at the highest latitudes, due to the large interannual variability in the data, nor in the tropics, due to the small trend magnitude, although it is projected that significant trends may be identified in these regions soon thereafter. While significant positive trends in total column ozone could be identified at all latitudes by ˜ 2030, column ozone values which are lower than the 1980 annual mean can occur in the mid-latitudes until ˜ 2050, and in the tropics and high latitudes deep into the second half of the 21st century.
Jia, Jin Tian; Fu, Zhi Yong; Chen, Hong Song; Wang, Ke Lin; Zhou, Wei Jun
2016-06-01
Based on three manually excavated trenches (projection length of 21 m, width of 1 m) along a typical Karst hillslope, the changing trends for soil-bedrock structure, average water content of soil profile and soil-bedrock interface water content along each individual trench were studied. The effect of irregular bedrock topography on soil moisture distribution was discussed. The results showed that the surface topography was inconsistent with the bedrock topography in the Karst hill-slopes. The bedrock topography was highly irregular with a maximum variation coefficient of 82%. The distribution pattern of soil profile of moisture was significantly affected by the underlying undulant bedrock. The soil water content was related to slope position when the fluctuation was gentle, and displayed a linear increase from upslope to downslope. When the bedrock fluctuation increased, the downslope linear increasing trend for soil water content became unapparent, and the spatial continuity of soil moisture was weakened. The soil moisture was converged in rock dents and cracks. The average water content of soil profile was significantly positively correlated with the soil-bedrock interface water content, while the latter responded more sensitively to the bedrock fluctuation.
ERTS-1 imagery of eastern Africa: A first look at the geological structure of selected areas
NASA Technical Reports Server (NTRS)
Mohr, P. A. (Principal Investigator)
1972-01-01
The author has identified the following significant results. Imagery of the African rift system resolves the major Cainozoic faults, zones of warping, and associated volcanism. It also clearly depicts the crystal grain of the Precambrian rocks where these are exposed. New structural features, or new properties of known features such as greater extent, continuity, and linearity are revealed by ERTS-1 imagery. This applies, for example, to the NE-SW fracture zones in Yemen, the Aswa mylonite zone at the northern end of the Western Rift, the Nandi fault of western Kenya, the linear faults of the Elgeyo escarpment in the Gregory Rift, and the hemibasins of warped Tertiary lavas on the Red Sea margin of Yemen, matching those of Ethiopian plateau-Afar margin. A tentative scheme is proposed, relating the effect on the pattern of Cainozoic faulting of the degree of obliquity to Precambrian structural trend. It is particularly noteworthy that, even where the Precambrian grain determines the rift faulting to be markedly oblique to the overall trend of the rift trough, for example, in central Lake Tanganyika, the width of the trough is not significantly increased. Some ground mapped lithological boundaries are obscure on ERTS-1 imagery.
Total ozone trends and variability during 1979-2012 from merged data sets of various satellites
NASA Astrophysics Data System (ADS)
Chehade, W.; Weber, M.; Burrows, J. P.
2014-07-01
The study presents a long-term statistical trend analysis of total ozone data sets obtained from various satellites. A multi-variate linear regression was applied to annual mean zonal mean data using various natural and anthropogenic explanatory variables that represent dynamical and chemical processes which modify global ozone distributions in a changing climate. The study investigated the magnitude and zonal distribution of the different atmospheric chemical and dynamical factors contributing to long-term total ozone changes. The regression model included the equivalent effective stratospheric chlorine (EESC), the 11-year solar cycle, the quasi-biennial oscillation (QBO), stratospheric aerosol loading describing the effects from major volcanic eruptions, the El Niño-Southern Oscillation (ENSO), the Arctic and Antarctic oscillation (AO/AAO), and accumulated eddy heat flux (EHF), the latter representing changes due to the Brewer-Dobson circulation. The total ozone column data set used here comprises the Solar Backscater Ultraviolet SBUV/SBUV-2 merged ozone data set (MOD) V8.6, the merged data set of the Solar Backscaterr Ultraviolet, the Total Ozone Mapping Spectrometer and the Ozone Monitoring Instrument SBUV/TOMS/OMI (1979-2012) MOD V8.0 and the merged data set of the Global Ozone Monitoring Experiment, the Scanning Imaging Absorption spectroMeter for Atmospheric ChartograpHY and the Global Ozone Monitoring Experiment 2 GOME/SCIAMACHY/GOME-2 (GSG) (1995-2012). The trend analysis was performed for twenty-six 5° wide latitude bands from 65° S to 65° N, and the analysis explained most of the ozone variability to within 70 to 90%. The results show that QBO dominates the ozone variability in the tropics (±7 DU) while at higher latitudes, the dynamical indices, AO/AAO and eddy heat flux, have substantial influence on total ozone variations by up to ±10 DU. The contribution from volcanic aerosols is only prominent during the major eruption periods (El Chichón and Mt. Pinatubo), and together with the ENSO signal, is more evident in the Northern Hemisphere. The signature of the solar cycle covers all latitudes and contributes about 10 DU from solar maximum to solar minimum. EESC is found to be a main contributor to the long-term ozone decline and the trend changes after the end of the 1990s. From the EESC fits, statistically significant upward trends after 1997 were found in the extratropics, which points at the slowing of ozone decline and the onset of ozone recovery. The EESC based trends are compared with the trends obtained from the statistical piecewise linear trend (PWLT) model (known as hockey stick) with a turnaround in 1997 to examine the differences between both approaches. In case of the SBUV merged V8.6 data the EESC and PWLT trends before and after 1997 are in good agreement (within 2 σ), however, the positive post-1997 linear trends from the PWLT regression are not significant within 2 σ. A sensitivity study is carried out by comparing the regression results, using SBUV/SBUV-2 MOD V8.6 merged time series (1979-2012) and a merged data set combining SBUV/SBUV-2 (1979-June 1995) and GOME/SCIAMACHY/GOME-2 ("GSG") WFDOAS (Weighting Function DOAS) (July 1995-2012) as well as SBUV/TOMS/OMI MOD V8.0 (1979-2012) in the regression analysis in order to investigate the uncertainty in the long-term trends due to different ozone data sets and data versions. Replacing the late SBUV/SBUV-2 merged data record with GSG data (unscaled and adjusted) leads to very similar results demonstrating the high consistency between satellite data sets. However, the comparison of the new SBUV/SBUV-2 MOD V8.6 with the MOD V8.0 and MOD8.6/GSG data showed somewhat smaller sensitivities with regard to several proxies as well as the linear EESC trends. On the other hand, the PWLT trends after 1997 show some differences, however, within the 2 σ error bars the PWLT trends agree with each other for all three data sets.
NASA Astrophysics Data System (ADS)
Bartiko, Daniel; Chaffe, Pedro; Bonumá, Nadia
2017-04-01
Floods may be strongly affected by climate, land-use, land-cover and water infrastructure changes. However, it is common to model this process as stationary. This approach has been questioned, especially when it involves estimate of the frequency and magnitude of extreme events for designing and maintaining hydraulic structures, as those responsible for flood control and dams safety. Brazil is the third largest producer of hydroelectricity in the world and many of the country's dams are located in the Southern Region. So, it seems appropriate to investigate the presence of non-stationarity in the affluence in these plants. In our study, we used historical flood data from the Brazilian National Grid Operator (ONS) to explore trends in annual maxima in river flow of the 38 main rivers flowing to Southern Brazilian reservoirs (records range from 43 to 84 years). In the analysis, we assumed a two-parameter log-normal distribution a linear regression model was applied in order to allow for the mean to vary with time. We computed recurrence reduction factors to characterize changes in the return period of an initially estimated 100 year-flood by a log-normal stationary model. To evaluate whether or not a particular site exhibits positive trend, we only considered data series with linear regression slope coefficients that exhibit significance levels (p<0,05). The significance level was calculated using the one-sided Student's test. The trend model residuals were analyzed using the Anderson-Darling normality test, the Durbin-Watson test for the independence and the Breusch-Pagan test for heteroscedasticity. Our results showed that 22 of the 38 data series analyzed have a significant positive trend. The trends were mainly in three large basins: Iguazu, Uruguay and Paranapanema, which suffered changes in land use and flow regularization in the last years. The calculated return period for the series that presented positive trend varied from 50 to 77 years for a 100 year-flood estimated by stationary model when considering a planning horizon equal to ten years. We conclude that attention should be given for future projects developed in this area, including the incorporation of non-stationarity analysis, search for answers to such changes and incorporation of new data to increase the reliability of the estimates.
Araz, Ozgur M; Bentley, Dan; Muelleman, Robert L
2014-09-01
Emergency department (ED) visits increase during the influenza seasons. It is essential to identify statistically significant correlates in order to develop an accurate forecasting model for ED visits. Forecasting influenza-like-illness (ILI)-related ED visits can significantly help in developing robust resource management strategies at the EDs. We first performed correlation analyses to understand temporal correlations between several predictors of ILI-related ED visits. We used the data available for Douglas County, the biggest county in Nebraska, for Omaha, the biggest city in the state, and for a major hospital in Omaha. The data set included total and positive influenza test results from the hospital (ie, Antigen rapid (Ag) and Respiratory Syncytial Virus Infection (RSV) tests); an Internet-based influenza surveillance system data, that is, Google Flu Trends, for both Nebraska and Omaha; total ED visits in Douglas County attributable to ILI; and ILI surveillance network data for Douglas County and Nebraska as the predictors and data for the hospital's ILI-related ED visits as the dependent variable. We used Seasonal Autoregressive Integrated Moving Average and Holt Winters methods with3 linear regression models to forecast ILI-related ED visits at the hospital and evaluated model performances by comparing the root means square errors (RMSEs). Because of strong positive correlations with ILI-related ED visits between 2008 and 2012, we validated the use of Google Flu Trends data as a predictor in an ED influenza surveillance tool. Of the 5 forecasting models we have tested, linear regression models performed significantly better when Google Flu Trends data were included as a predictor. Regression models including Google Flu Trends data as a predictor variable have lower RMSE, and the lowest is achieved when all other variables are also included in the model in our forecasting experiments for the first 5 weeks of 2013 (with RMSE = 57.61). Google Flu Trends data statistically improve the performance of predicting ILI-related ED visits in Douglas County, and this result can be generalized to other communities. Timely and accurate estimates of ED volume during the influenza season, as well as during pandemic outbreaks, can help hospitals plan their ED resources accordingly and lower their costs by optimizing supplies and staffing and can improve service quality by decreasing ED wait times and overcrowding. Copyright © 2014 Elsevier Inc. All rights reserved.
McIntire, Russell K; Macy, Jonathan T; Seo, Dong-Chul; Nelson, Ashlyn A; Kolbe, Lloyd J
2014-06-01
Young people in the United States are exposed to secondhand smoke (SHS) primarily in 2 settings: homes and cars. Recently, researchers reported that the prevalence of U.S students exposed to SHS in cars decreased from 2000 to 2009; however, comparisons of trends across school levels, gender, and racial/ethnic groups were not assessed. Moreover, no studies have examined trends of exposure to SHS in rooms. We used data from the 2000, 2002, 2004, 2006, and 2009 waves of the National Youth Tobacco Survey, a nationally representative cross-sectional survey of U.S. middle and high school students. For SHS in cars and rooms, we identified exposure trends among nonsmokers from 2000 to 2009 and compared trends across subpopulations with binary logistic regression. We identified significant downward linear trends in SHS in cars and rooms for nearly all measured subpopulations of nonsmoking students from 2000 to 2009. SHS exposure in cars and rooms declined at a significantly greater rate for males than for females. SHS exposure in cars declined at a significantly greater rate for non-Hispanic (NH) Blacks than for NH Whites. SHS exposure in rooms declined at a significantly greater rate for NH Whites than for Hispanics and Native Hawaiians/Pacific Islanders. Although prevalence of exposure to SHS in cars and rooms among nonsmoking U.S. middle and high school students has declined from 2000 to 2009, the rates of decline were not equal across genders and racial/ethnic groups. Identification of these differing rates of exposure can help the public health community advocate for interventions focused on reducing adolescent SHS exposure.
Christine, Paul J; Diez Roux, Ana V; Wing, Jeffrey J; Alazraqui, Marcio; Spinelli, Hugo
2015-04-01
We investigated temporal trends in BMI, and assessed hypothesized predictors of trends including socio-economic position (SEP) and province-level economic development, in Argentina. Using multivariable linear regression, we evaluated cross-sectional patterning and temporal trends in BMI and examined heterogeneity in these associations by SEP and province-level economic development with nationally representative samples from Argentina in 2005 and 2009. We calculated mean annual changes in BMI for men and women to assess secular trends. Women, but not men, exhibited a strong cross-sectional inverse association between SEP and BMI, with the lowest-SEP women having an average BMI 2.55 kg/m(2) greater than the highest-SEP women. Analysis of trends revealed a mean annual increase in BMI of 0.19 kg/m(2) and 0.15 kg/m(2) for women and men, respectively, with slightly greater increases occurring in provinces with greater economic growth. No significant heterogeneity in trends existed by individual SEP. BMI is increasing rapidly over time in Argentina irrespective of various sociodemographic characteristics. Higher BMI remains more common in women of lower SEP compared with those of higher SEP.
NASA Astrophysics Data System (ADS)
Yadav, Shweta; Tandon, Ankit; Attri, Arun K.
2014-12-01
The detection of nicotine, an organic tracer for Environmental Tobacco Smoke (ETS), in the collected PM10 samples from Delhi region's ambient environment, in a appropriately designed investigation was initiated over four years (2006-2009) to: (1) Comprehend seasonal and inter-annual variations in the nicotine present in PM10; (2) Extract regression based linear trend profile manifested by nicotine in PM10; (3) Determine the non-linear trend timeline from the nicotine data, and compare it with the obtained linear trend; (4) Suggest the possible use of the designed experiment and analysis to have a qualitative appraisal of Tobacco Smoking activity in the sampling region. The PM10 samples were collected in a monthly time-series sequence at a known receptor site. Quantitative estimates of nicotine (ng m-3) were made by using a Thermal Desorption Gas Chromatography Mass Spectrometry (TD-GC/MS). The annual average concentrations of nicotine (ng m-3) were 516 ± 302 (2008) > 494 ± 301 (2009) > 438 ± 250 (2007) > 325 ± 149 (2006). The estimated linear trend of 5.4 ng m-3 month-1 corresponded to 16.3% per annum increase in the PM10 associated nicotine. The industrial production of India's tobacco index normalized to Delhi region's consumption, pegged an increase at 10.5% per annum over this period.
Analysis of ERTS-1 linear features in New York State
NASA Technical Reports Server (NTRS)
Isachsen, Y. W. (Principal Investigator); Fakundiny, R. H.; Forster, S. W.
1974-01-01
The author has identified the following significant results. All ERTS-1 linears confirmed to date have topographic expression although they may appear as featureless tonal linears on the imagery. A bias is unavoidably introduced against any linears which may parallel raster lines, lithological trends, or the azimuth of solar illumination. Ground study of ERTS-1 topographic lineaments in the Adirondacks indicates: outcrops along linears are even more rare than expected, fault breccias are found along some NNE lineaments, chloritization and slickensiding without brecciation characterize one EW lineament whereas closely-spaced jointing plus a zone of plastic shear define another. Field work in the Catskills suggests that the prominent new NNE lineaments may be surface manifestations of normal faulting in the basement, and that it may become possible to map major joint sets over extensive plateau regions directly on the imagery. Fall and winter images each display some unique linears, and long linears on the fall image commonly appear as aligned segments on the winter scene. A computer-processed color composite image permitted the extraction or additional information on the shaded side of mountains.
NASA Astrophysics Data System (ADS)
Gruzdev, A. N.
2009-04-01
Data of spectrometric ground-based measurements of stratospheric column NO2 contents at stations within the Network for the Detection of Atmospheric Composition Change (NDACC) are analyzed for linear trends. The trend analysis takes into account the NO2 seasonal variation, effects of the 11-year solar and geomagnetic activity cycles, effects of the quasi-biennial oscillation and the El Nino - Southern Oscillation, and the effects of the El Chichon and Pinatubo eruptions. The latitudinal distributions of the annual and seasonal trends in NO2 have been obtained. The annual trends are mostly positive in the southern hemisphere middle and low latitudes and negative in the European sector of the northern hemisphere middle latitudes. In the high and polar latitudes of the two hemispheres, the annual estimates of trends are mostly statistically insignificant. However, a positive NO2 trend is observed at 78°S in the Antarctic, while positive and negative trends are observed in the northern hemisphere high latitudes. The maximum positive and negative trends are about 10% per decade by module. Seasonal estimates of the trends differ generally from the annual estimates. At stations of Zvenigorod, Jungfraujoch (northern hemisphere middle latitudes), Lauder, and Macquarie Island (southern hemisphere middle latitudes) the signs of the NO2 trends do not depend on season, although the trend values vary with season. At other stations, trend values, their statistical significance, and even their signs can vary with season. Nitrogen oxides affects the photochemical balance of stratospheric ozone directly and indirectly, influencing the effectiveness of ozone destruction in the chlorine cycle. The observed significant trends in stratospheric NO2 should result in noticeable perturbations of the rates of ozone destruction in the nitrogen cycle. The sensitivities of photochemical balance of stratospheric ozone to long-term changes in stratospheric NO2 and chlorine are estimated using a combination of analytical and one-dimensional photochemical models.
NASA Astrophysics Data System (ADS)
Ahmadalipour, A.; Rana, A.; Qin, Y.; Moradkhani, H.
2014-12-01
Trends and changes in future climatic parameters, such as, precipitation and temperature have been a central part of climate change studies. In the present work, we have analyzed the seasonal and yearly trends and uncertainties of prediction in all the 10 sub-basins of Columbia River Basin (CRB) for future time period of 2010-2099. The work is carried out using 2 different sets of statistically downscaled Global Climate Model (GCMs) projection datasets i.e. Bias correction and statistical downscaling (BCSD) generated at Portland State University and The Multivariate Adaptive Constructed Analogs (MACA) generated at University of Idaho. The analysis is done for with 10 GCM downscaled products each from CMIP5 daily dataset totaling to 40 different downscaled products for robust analysis. Summer, winter and yearly trend analysis is performed for all the 10 sub-basins using linear regression (significance tested by student t test) and Mann Kendall test (0.05 percent significance level), for precipitation (P), temperature maximum (Tmax) and temperature minimum (Tmin). Thereafter, all the parameters are modelled for uncertainty, across all models, in all the 10 sub-basins and across the CRB for future scenario periods. Results have indicated in varied degree of trends for all the sub-basins, mostly pointing towards a significant increase in all three climatic parameters, for all the seasons and yearly considerations. Uncertainty analysis have reveled very high change in all the parameters across models and sub-basins under consideration. Basin wide uncertainty analysis is performed to corroborate results from smaller, sub-basin scale. Similar trends and uncertainties are reported on the larger scale as well. Interestingly, both trends and uncertainties are higher during winter period than during summer, contributing to large part of the yearly change.
NASA Astrophysics Data System (ADS)
Clem, Kyle R.; Renwick, James A.; McGregor, James
2017-07-01
During 1979-2014, eastern tropical Pacific sea surface temperatures significantly cooled, which has generally been attributed to the transition of the Pacific Decadal Oscillation to its negative phase after 1999. We find the eastern tropical Pacific cooling to be associated with: (1) an intensified Walker Circulation during austral summer (December-February, DJF) and autumn (March-May, MAM); (2) a weakened South Pacific Hadley cell and subtropical jet during MAM; and (3) a strengthening of the circumpolar westerlies between 50 and 60°S during DJF and MAM. Observed cooling in the eastern tropical Pacific is linearly congruent with 60-80 % of the observed Southern Hemisphere positive zonal-mean zonal wind trend between 50 and 60°S during DJF ( 35 % of the interannual variability), and around half of the observed positive zonal-mean zonal wind trend during MAM ( 15 % of the interannual variability). Although previous studies have linked the strengthened DJF and MAM circumpolar westerlies to stratospheric ozone depletion and increasing greenhouse gases, we note that the continuation of the positive SAM trends into the twenty-first century is partially associated with eastern tropical Pacific cooling, especially during MAM when zonal wind anomalies associated with eastern tropical Pacific cooling project strongly onto the observed trends. Outside of DJF and MAM, eastern tropical Pacific cooling is associated with opposing zonal wind anomalies over the Pacific and Indian sectors, which we infer is the reason for the absence of significant positive SAM trends outside of DJF and MAM despite significant eastern tropical Pacific cooling seen during all seasons.
Gender Trends in Radiology Authorship: A 35-Year Analysis.
Piper, Crystal L; Scheel, John R; Lee, Christoph I; Forman, Howard P
2016-01-01
The purpose of this study was to describe trends over time in female authorship in the radiology literature and to investigate the tendency of female first authors to publish with female senior authors. Data on the gender of academic physician authors based in the United States for all major articles published in three general radiology journals--Radiology, AJR, and Academic Radiology--were collected and analyzed for the years 1978, 1988, 1998, 2008, and 2013. Multivariate logistic regression was used to identify significant trends over time, and a chi-square test of independence was performed to determine significant relations between the genders of first and senior authors. The gender of 4182 of 4217 (99.17%) authors with MD degrees was determined. The proportion of original research articles published by women as first authors increased from 8.33% in 1978 to 32.35% in 2013 (p < 0.001). The proportion of original research articles with women as senior authors increased from 6.75% in 1978 to 21.90% in 2013 (p < 0.001). Female first and senior authorship increased significantly over time (first author, p < 0.001; senior author, p < 0.001). There was a statistically significant relation between the genders of first and senior authors of original research articles and guest editorials (p < 0.001). Over 35 years, there was a statistically significant upward linear trend of female physician participation in authorship of academic radiology literature. Female first authors were more likely to publish with female senior authors.
Sleep Tendency and Ability to Sustain Wakefulness
2000-03-01
Pratica di Mare, 00040 Pomezia (Roma) Italy 2 Dipartimento di Psicologia - Universitd di Roma "La Sapienza" Via del policlinico 155 00161 Roma Italy...and the score was taken as ANOVA showed a significant effect for Test latency to the first epoch of any stage of sleep. If (Fl, 7 =31.02; p=.001), with...linear trend during Test x Condition x Session (F3,2 1ə) interaction the night only for MSLT (FI, 7 = 23.83; p=.00 2, was not significant. In the table
NASA Astrophysics Data System (ADS)
Pournasiri Poshtiri, M.; Pal, I.
2015-12-01
Climate non-stationarity affects regional hydrological extremes. This research looks into historic patterns of streamflow drought indicators and their evolution for major watershed regions in the conterminous U.S. (CONUS). The results indicate general linear and non-linear drying trends, particularly in the last four decades, as opposed to wetting trends reported in previous studies. Regional differences in the trends are notable, and echo the local climatic changes documented in the recent National Climate Assessment (NCA). A reversal of linear trends is seen for some northern regions after 1980s. Patterns in return periods and corresponding return values of the indicators are also examined, which suggests changing risk conditions that are important for water-resources decision-making. Persistent or flash drought conditions in a river can lead to chronic or short-term water scarcity—a main driver of societal and cross-boundary conflicts. Thus, this research identifies "hotspot" locations where suitable adaptive management measures are most needed.
Wagner, Tyler; Irwin, Brian J.; James R. Bence,; Daniel B. Hayes,
2016-01-01
Monitoring to detect temporal trends in biological and habitat indices is a critical component of fisheries management. Thus, it is important that management objectives are linked to monitoring objectives. This linkage requires a definition of what constitutes a management-relevant “temporal trend.” It is also important to develop expectations for the amount of time required to detect a trend (i.e., statistical power) and for choosing an appropriate statistical model for analysis. We provide an overview of temporal trends commonly encountered in fisheries management, review published studies that evaluated statistical power of long-term trend detection, and illustrate dynamic linear models in a Bayesian context, as an additional analytical approach focused on shorter term change. We show that monitoring programs generally have low statistical power for detecting linear temporal trends and argue that often management should be focused on different definitions of trends, some of which can be better addressed by alternative analytical approaches.
Harsha, Asheesh K; Schmitt, J Eric; Stavropoulos, S William
2014-01-01
To analyze Internet search data to characterize the temporal and geographic interest of Internet users in the United States in varicose vein treatment. From January 1, 2004, to September 1, 2012, the Google Trends tool was used to analyze query data for "varicose vein treatment" to identify individuals seeking treatment information for varicose veins. The term "varicose vein treatment" returned a search volume index (SVI), representing the search frequency relative to the total search volume during a specific time interval and region. Linear regression analysis and Kruskal-Wallis one-way analysis of variance were employed to characterize search results. Search traffic for varicose vein treatment increased by 520% over the 104-month study period. There was an annual mean increase of 28% (range, -18%-100%; standard deviation [SD], 35%), with a statistically significant linear increase in average yearly SVI over time (R(2) = 0.94, P < .0001). All years showed positive growth in mean SVI except for 2008 (18% decrease). There were statistically significant differences in SVI by month (Kruskal-Wallis, P < .0001) with significantly higher mean SVI compared with other months in May (190% increase; range, 26%-670%; SD, 15%) and June (209% increase; range, 35%-700%; SD, 20%). The southern United States showed significantly higher search traffic than all other regions (Tukey-Kramer, P < .00001). There have been significant increases in Internet search traffic related to varicose vein treatment in the past 8 years. Reflected in this trend is an annual peak in search traffic in the late spring months with an overall geographic bias toward southern states. Rigorous analysis of Internet search queries for medical procedures may prove useful to guide the efficient use of limited resources and marketing dollars. © 2013 The Society of Interventional Radiology Published by SIR All rights reserved.
Trends in MD/PhD Graduates Entering Psychiatry: Assessing the Physician-Scientist Pipeline.
Arbuckle, Melissa R; Luo, Sean X; Pincus, Harold Alan; Gordon, Joshua A; Chung, Joyce Y; Chavez, Mark; Oquendo, Maria A
2018-06-01
The goal of this study was to identify trends in MD/PhD graduates entering psychiatry, to compare these trends with other specialties, and to review strategies for enhancing the physician-scientist pipeline. Data on 226,588 medical students graduating from Liaison Committee on Medical Education accredited programs between 1999 and 2012 (6626 MD/PhDs) were used to evaluate the number, percentage, and proportion of MD/PhDs entering psychiatry in comparison with other specialties (neurology, neurosurgery, internal medicine, family medicine, and radiation oncology). Linear regression and multiple linear regression determined whether these values increased over time and varied by sex. Over 14 years, an average of 18 MD/PhDs (range 13-29) enrolled in psychiatry each year. The number of MD/PhDs going into psychiatry significantly increased, although these gains were modest (less than one additional MD/PhD per year). The proportion of students entering psychiatry who were MD/PhDs varied between 2.9 and 5.9 per 100 residents, with no significant change over time. There was also no change in the percentage of MD/PhDs entering psychiatry from among all MD/PhD graduates. The rate of increase in the number of MD/PhDs going into psychiatry did not differ significantly from other specialties except for family medicine, which is decreasing. The rate of MD/PhDs going into psychiatry was higher for women, suggesting closure of the sex gap in 17 years. Despite the increase in the number of MD/PhDs entering psychiatry, these numbers remain low. Expanding the cohort of physician-scientists dedicated to translational research in psychiatry will require a multipronged approach.
Ding, Ming; Satija, Ambika; Bhupathiraju, Shilpa N; Hu, Yang; Sun, Qi; Han, Jiali; Lopez-Garcia, Esther; Willett, Walter; van Dam, Rob M.; Hu, Frank B.
2015-01-01
Background The association between consumption of caffeinated and decaffeinated coffee and risk of mortality remains inconclusive. Methods and Results We examined the associations of consumption of total, caffeinated, and decaffeinated coffee with risk of subsequent total and cause-specific mortality among 74,890 women in the Nurses’ Health Study (NHS), 93,054 women in the NHS 2, and 40,557 men in the Health Professionals Follow-up Study. Coffee consumption was assessed at baseline using a semi-quantitative food frequency questionnaire. During 4,690,072 person-years of follow-up, 19,524 women and 12,432 men died. Consumption of total, caffeinated, and decaffeinated coffee were non-linearly associated with mortality. Compared to non-drinkers, coffee consumption one to five cups/d was associated with lower risk of mortality, while coffee consumption more than five cups/d was not associated with risk of mortality. However, when restricting to never smokers, compared to non-drinkers, the HRs of mortality were 0.94 (0.89 to 0.99) for ≤ 1 cup/d, 0.92 (0.87 to 0.97) for 1.1-3 cups/d, 0.85 (0.79 to 0.92) for 3.1-5 cups/d, and 0.88 (0.78 to 0.99) for > 5 cups/d (p for non-linearity = 0.32; p for trend < 0.001). Significant inverse associations were observed for caffeinated (p for trend < 0.001) and decaffeinated coffee (p for trend = 0.022). Significant inverse associations were observed between coffee consumption and deaths due to cardiovascular disease, neurological diseases, and suicide. No significant association between coffee consumption and total cancer mortality was found. Conclusions Higher consumption of total coffee, caffeinated coffee, and decaffeinated coffee was associated with lower risk of total mortality. PMID:26572796
Trend of annual temperature and frequency of extreme events in the MATOPIBA region of Brazil
NASA Astrophysics Data System (ADS)
Salvador, Mozar de A.; de Brito, J. I. B.
2017-06-01
During the 1980s, a new agricultural frontier arouse in Brazil, which occupied part of the states of Maranhão, Tocantins, Piauí, and Bahia. Currently, this new frontier is known as the MATOPIBA region. The region went through intense transformations in its social and environmental characteristics, with the emergence of extensive areas of intensive agriculture and large herds. The purpose of this research was to study the climatic variabilities of temperature in the MATOPIBA region through extreme climate indexes of ClimAp tool. Data from 11 weather stations were analyzed for yearly air temperature (maximum and minimum) in the period of 1970 to 2012. To verify the trend in the series, we used methods of linear regression analysis and Kendall-tau test. The annual analysis of maximum and minimum temperatures and of the temperature extremes indexes showed a strong positive trend in practically every series (with p value less than 0.05). These results indicated that the region went through to a significant heating process in the last 3 decades. The indices of extreme also showed a significant positive trend in most of the analyzed stations, indicating a higher frequency of warm days during the year.
NASA Technical Reports Server (NTRS)
Cook, Benjamin I.; Pau, Stephanie
2013-01-01
Pasture ecosystems may be particularly vulnerable to land degradation due to the high risk of human disturbance (e.g., overgrazing, burning, etc.), especially when compared with natural ecosystems (non-pasture, non-cultivated) where direct human impacts are minimal. Using maximum annual leaf area index (LAImax) as a proxy for standing biomass and peak annual aboveground productivity, we analyze greening and browning trends in pasture areas from 1982-2008. Inter-annual variability in pasture productivity is strongly controlled by precipitation (positive correlation) and, to a lesser extent, temperature (negative correlation). Linear temporal trends are significant in 23% of pasture cells, with the vast majority of these areas showing positive LAImax trends. Spatially extensive productivity declines are only found in a few regions, most notably central Asia, southwest North America, and southeast Australia. Statistically removing the influence of precipitation reduces LAImax trends by only 13%, suggesting that precipitation trends are only a minor contributor to long-term greening and browning of pasture lands. No significant global relationship was found between LAImax and pasture intensity, although the magnitude of trends did vary between cells classified as natural versus pasture. In the tropics and Southern Hemisphere, the median rate of greening in pasture cells is significantly higher than for cells dominated by natural vegetation. In the Northern Hemisphere extra-tropics, conversely, greening of natural areas is 2-4 times the magnitude of greening in pasture areas. This analysis presents one of the first global assessments of greening and browning trends in global pasture lands, including a comparison with vegetation trends in regions dominated by natural ecosystems. Our results suggest that degradation of pasture lands is not a globally widespread phenomenon and, consistent with much of the terrestrial biosphere, there have been widespread increases in pasture productivity over the last 30 years.
NASA Technical Reports Server (NTRS)
Weber, Mark; Coldewey-Egbers, Melanie; Fioletov, Vitali E.; Frith, Stacey M.; Wild, Jeannette D.; Burrows, John P.; Loyola, Diego
2018-01-01
We report on updated trends using different merged datasets from satellite and ground-based observations for the period from 1979 to 2016. Trends were determined by applying a multiple linear regression (MLR) to annual mean zonal mean data. Merged datasets used here include NASA MOD v8.6 and National Oceanic and Atmospheric Administration (NOAA) merge v8.6, both based on data from the series of Solar Backscatter UltraViolet (SBUV) and SBUV-2 satellite instruments (1978–present) as well as the Global Ozone Monitoring Experiment (GOME)-type Total Ozone (GTO) and GOME-SCIAMACHY-GOME-2 (GSG) merged datasets (1995-present), mainly comprising satellite data from GOME, the Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY), and GOME-2A. The fifth dataset consists of the monthly mean zonal mean data from ground-based measurements collected at World Ozone and UV Data Center (WOUDC). The addition of four more years of data since the last World Meteorological Organization (WMO) ozone assessment (2013-2016) shows that for most datasets and regions the trends since the stratospheric halogen reached its maximum (approximately 1996 globally and approximately 2000 in polar regions) are mostly not significantly different from zero. However, for some latitudes, in particular the Southern Hemisphere extratropics and Northern Hemisphere subtropics, several datasets show small positive trends of slightly below +1 percent decade(exp. -1) that are barely statistically significant at the 2 Sigma uncertainty level. In the tropics, only two datasets show significant trends of +0.5 to +0.8 percent(exp.-1), while the others show near-zero trends. Positive trends since 2000 have been observed over Antarctica in September, but near-zero trends are found in October as well as in March over the Arctic. Uncertainties due to possible drifts between the datasets, from the merging procedure used to combine satellite datasets and related to the low sampling of ground-based data, are not accounted for in the trend analysis. Consequently, the retrieved trends can be only considered to be at the brink of becoming significant, but there are indications that we are about to emerge into the expected recovery phase. However, the recent trends are still considerably masked by the observed large year-to-year dynamical variability in total ozone.
NASA Astrophysics Data System (ADS)
Weber, Mark; Coldewey-Egbers, Melanie; Fioletov, Vitali E.; Frith, Stacey M.; Wild, Jeannette D.; Burrows, John P.; Long, Craig S.; Loyola, Diego
2018-02-01
We report on updated trends using different merged datasets from satellite and ground-based observations for the period from 1979 to 2016. Trends were determined by applying a multiple linear regression (MLR) to annual mean zonal mean data. Merged datasets used here include NASA MOD v8.6 and National Oceanic and Atmospheric Administration (NOAA) merge v8.6, both based on data from the series of Solar Backscatter UltraViolet (SBUV) and SBUV-2 satellite instruments (1978-present) as well as the Global Ozone Monitoring Experiment (GOME)-type Total Ozone (GTO) and GOME-SCIAMACHY-GOME-2 (GSG) merged datasets (1995-present), mainly comprising satellite data from GOME, the Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY), and GOME-2A. The fifth dataset consists of the monthly mean zonal mean data from ground-based measurements collected at World Ozone and UV Data Center (WOUDC). The addition of four more years of data since the last World Meteorological Organization (WMO) ozone assessment (2013-2016) shows that for most datasets and regions the trends since the stratospheric halogen reached its maximum (˜ 1996 globally and ˜ 2000 in polar regions) are mostly not significantly different from zero. However, for some latitudes, in particular the Southern Hemisphere extratropics and Northern Hemisphere subtropics, several datasets show small positive trends of slightly below +1 % decade-1 that are barely statistically significant at the 2σ uncertainty level. In the tropics, only two datasets show significant trends of +0.5 to +0.8 % decade-1, while the others show near-zero trends. Positive trends since 2000 have been observed over Antarctica in September, but near-zero trends are found in October as well as in March over the Arctic. Uncertainties due to possible drifts between the datasets, from the merging procedure used to combine satellite datasets and related to the low sampling of ground-based data, are not accounted for in the trend analysis. Consequently, the retrieved trends can be only considered to be at the brink of becoming significant, but there are indications that we are about to emerge into the expected recovery phase. However, the recent trends are still considerably masked by the observed large year-to-year dynamical variability in total ozone.
Long-term decrease in phosphate concentrations in the surface layer of the southern Japan Sea
NASA Astrophysics Data System (ADS)
Kodama, Taketoshi; Igeta, Yosuke; Kuga, Mizuki; Abe, Shoko
2016-10-01
To identify possible causes for the long-term trends in nutrient concentrations in the southern Japan Sea (JS), we studied nutrient concentrations that were obtained by the Japan Meteorological Agency. Our evaluation shows that phosphate concentrations declined in the surface layers in summer (0-20 and 21-50 m depth) and winter (0-20, 21-50, and 51-100 m depth) over the last 40 years, while no significant linear trend was observed for nitrate concentrations. The declining trend in the phosphate concentration was quantified as 1.8-3.3 nM yr-1. The increase in atmospheric nutrient deposition to the JS could not explain the decline in phosphate concentration. In addition, the mixed-layer depth during winter did not demonstrate any significant trend, and an increase in phosphate concentrations was not observed in any layers; therefore, the decrease in nutrient supply from deep JS water was not considered a major possible cause for the decline in the phosphate concentration. In contrast, the phosphate concentration in the surface of the southern JS during winter showed a significant positive correlation with the concentration in the 21-50 m depth layer of the saline East China Sea (ECS) water in the preceding summer, and the surface water of the southern JS was almost entirely replaced by water originating from the ECS during May-October. Therefore, it is concluded that the declining trend in the phosphate concentrations in the southern JS is caused by horizontal advection of ECS water.
NASA Astrophysics Data System (ADS)
Cui, Lifang; Wang, Lunche; Lai, Zhongping; Tian, Qing; Liu, Wen; Li, Jun
2017-11-01
The variation characteristics of air temperature and precipitation in the Yangtze River Basin (YRB), China during 1960-2015 were analysed using a linear regression (LR) analysis, a Mann-Kendall (MK) test with Sen's slope estimator and Sen's innovative trend analysis (ITA). The results showed that the annual maximum, minimum and mean temperature significantly increased at the rate of 0.15°C/10yr, 0.23°C/10yr and 0.19°C/10yr, respectively, over the whole study area during 1960-2015. The warming magnitudes for the above variables during 1980-2015 were much higher than those during 1960-2015:0.38°C/10yr, 0.35°C/10yr and 0.36°C/10yr, respectively. The seasonal maximum, minimum and mean temperature significantly increased in the spring, autumn and winter seasons during 1960-2015. Although the summer temperatures also increased at some extent, only the minimum temperature showed a significant increasing trend. Meanwhile, the highest rate of increase of seasonal mean temperature occurred in winter (0.24°C/10yr) during 1960-2015 and spring (0.50°C/10yr) during 1980-2015, which indicated that the significant warming trend for the whole YRB could be attributed to the remarkable temperature increases in winter and spring months. However, both the annual and seasonal warming magnitudes showed large regional differences, and a higher warming rate was detected in the eastern YRB and the western source region of the Yangtze River on the Qinghai-Tibetan Plateau (QTP). Additionally, annual precipitation increased by approximately 12.02 mm/10yr during 1960-2015 but decreased at the rate of 19.63 mm/10yr during 1980-2015. There were decreasing trends for precipitation in all four seasons since 1980 in the YRB, and a significant increasing trend was only detected in summer since 1960 (12.37 mm/10yr). Overall, a warming-wetting trend was detected in the south-eastern and north-western YRB, while there was a warming-drying trend in middle regions.
Albuminuria and masked uncontrolled hypertension in chronic kidney disease.
Agarwal, Rajiv
2017-12-01
Masked uncontrolled hypertension (MUCH) is associated with greater target organ damage such as left ventricular hypertrophy, increased arterial stiffness and albuminuria. Whether MUCH independently associates with greater cardiovascular end-organ damage or kidney damage is unclear. The objective of this study was to assess the strength of the relationship of MUCH (awake ambulatory blood pressure ≥135/85 mmHg and clinic blood pressure <140/90 mmHg) with target organ damage. In a cross-sectional study at a veterans' administration medical center, clinically normotensive veterans without chronic kidney disease (CKD) (n = 29) and 287 patients with CKD and controlled hypertension (CH, n = 193), MUCH (n = 67) and uncontrolled hypertension (UCH, n = 27) had evaluation of target organ damage. Target organ damage was measured by echocardiography [left ventricular mass index (LVMI)], arterial ultrasonography [aortic pulse wave velocity (PWV)] and 24-h urine collection [albuminuria (urine albumin to creatinine ratio)] in all participants. Compared to that of controls, LVMI was higher by 21.8 g/m2 (CI, 4.0-39.7 g/m2) in CH, 27.9 (CI, 8-47.8) in MUCH and 39.5 (CI, 15.7-63.2) in UCH (P < 0.01 for group differences, P < 0.01 for linear trend). Although differences persisted after adjustment for age, sex and race, they lost significance after adjustments for cardiovascular risk factors and their treatment. Compared to that of controls, PWV was different among CH, MUCH and UCH (P = 0.04 for group differences, P = 0.02 for linear trend). However, differences lost significance after adjustments for age, sex and race. Compared to that of controls, log2 UACR was higher by 2.40 mg/mg (CI, 1.28-3.52) in CH, 4.94 (CI, 3.70-6.18) in MUCH and 6.01 (CI, 4.49-7.53) in UCH (P < 0.0001 for group difference, P < 0.0001 for linear trend). Differences persisted after adjustment for age, sex and race, cardiovascular risk factors and their treatment and cardiovascular disease (P < 0.0001 for group difference, P < 0.0001 for linear trend). MUCH is more strongly related to albuminuria compared with cardiovascular damage as assessed by left ventricular mass and PWV. A graded and an independent relationship of blood pressure classification status with albuminuria is consistent with the hypothesis that renal mechanisms may be more important than cardiovascular disease in mediating the pathogenesis of MUCH. Published by Oxford University Press on behalf of ERA-EDTA 2016. This work is written by a US Government employee and is in the public domain in the US.
Sharma, Munesh K; Singh, Tarundeep; Pandey, Avdesh K; Kankaria, Ankita
2015-01-01
Cancer has become an epidemic disease. Nearly ten million new cancer cases are diagnosed annually in the world and out of these about half are from the developing world. To appropriately plan for treatment, management and prevention of the disease, it becomes necessary to study the trends about morbidity caused by cancers. Data for patients diagnosed with any form of gastrointestinal (GI) cancers was extracted from records maintained in the outpatient department registers of the Oncology Department of Government Medical College and Hospital in Chandigarh from 1999 to 2012. Trends were analysed for different categories of GI cancers for the period of 12 years. In present study GI cancers accounted for 23 % of all registered cases (n-9603) of carcinomas. Males predominated for all GI cancers except in the gall bladder. Gastrointestinal cancers as a proportion of total cancers increased from 21% in 1999 to 25.9% in 2012 with a significant increasing trend in our series (χ2 for linear trend=9.36, p<0.003). Cancers of the tonsil, oral cavity and pharynx taken together showed an increasing trend over the years (χ2 for trend=55.2, p<0.001) whereas cancers of the lower GI (χ2=19.6, p<0.0001) and gall bladder (χ2=19.5, p<0.0001) showed a declining trend in our series. GI cancers form a significant proportion of all cancers reporting to our data. In depth studies to ascertain the reasons for the changing trends are required to design intervention programs. Further information is necessary from cancer registries and from the hospital records of oncology departments.
NASA Technical Reports Server (NTRS)
Remsberg, E. E.
2008-01-01
Results are presented on responses in 14-yr time series of stratospheric ozone and temperature from the Halogen Occultation Experiment (HALOE) of the Upper Atmosphere Research Satellite (UARS) to a solar cycle (SC-like) variation. The ozone time series are for ten, 20-degree wide, latitude bins from 45S to 45N and for thirteen "half-Umkehr" layers of about 2.5 km thickness and extending from 63 hPa to 0.7 hPa. The temperature time series analyses were restricted to pressure levels in the range of 2 hPa to 0.7 hPa. Multiple linear regression (MLR) techniques were applied to each of the 130 time series of zonally-averaged, sunrise plus sunset ozone points over that latitude/pressure domain. A simple, 11-yr periodic term and a linear trend term were added to the final MLR models after their seasonal and interannual terms had been determined. Where the amplitudes of the 11-yr terms were significant, they were in-phase with those of the more standard proxies for the solar uv-flux. The max minus min response for ozone is of order 2 to 3% from about 2 to 5 hPa and for the latitudes of 45S to 45N. There is also a significant max minus min response of order 1 K for temperature between 15S and 15N and from 2 to 0.7 hPa. The associated linear trends for ozone are near zero in the upper stratosphere. Negative ozone trends of 4 to 6%/decade were found at 10 to 20 hPa across the low to middle latitudes of both hemispheres. It is concluded that the analyzed responses from the HALOE data are of good quality and can be used to evaluate the responses of climate/chemistry models to a solar cycle forcing.
Statistical power for detecting trends with applications to seabird monitoring
Hatch, Shyla A.
2003-01-01
Power analysis is helpful in defining goals for ecological monitoring and evaluating the performance of ongoing efforts. I examined detection standards proposed for population monitoring of seabirds using two programs (MONITOR and TRENDS) specially designed for power analysis of trend data. Neither program models within- and among-years components of variance explicitly and independently, thus an error term that incorporates both components is an essential input. Residual variation in seabird counts consisted of day-to-day variation within years and unexplained variation among years in approximately equal parts. The appropriate measure of error for power analysis is the standard error of estimation (S.E.est) from a regression of annual means against year. Replicate counts within years are helpful in minimizing S.E.est but should not be treated as independent samples for estimating power to detect trends. Other issues include a choice of assumptions about variance structure and selection of an exponential or linear model of population change. Seabird count data are characterized by strong correlations between S.D. and mean, thus a constant CV model is appropriate for power calculations. Time series were fit about equally well with exponential or linear models, but log transformation ensures equal variances over time, a basic assumption of regression analysis. Using sample data from seabird monitoring in Alaska, I computed the number of years required (with annual censusing) to detect trends of -1.4% per year (50% decline in 50 years) and -2.7% per year (50% decline in 25 years). At ??=0.05 and a desired power of 0.9, estimated study intervals ranged from 11 to 69 years depending on species, trend, software, and study design. Power to detect a negative trend of 6.7% per year (50% decline in 10 years) is suggested as an alternative standard for seabird monitoring that achieves a reasonable match between statistical and biological significance.
NASA Astrophysics Data System (ADS)
Kryanev, A. V.; Ivanov, V. V.; Romanova, A. O.; Sevastyanov, L. A.; Udumyan, D. K.
2018-03-01
This paper considers the problem of separating the trend and the chaotic component of chaotic time series in the absence of information on the characteristics of the chaotic component. Such a problem arises in nuclear physics, biomedicine, and many other applied fields. The scheme has two stages. At the first stage, smoothing linear splines with different values of smoothing parameter are used to separate the "trend component." At the second stage, the method of least squares is used to find the unknown variance σ2 of the noise component.
Spacecraft-borne long life cryogenic refrigeration: Status and trends
NASA Technical Reports Server (NTRS)
Johnson, A. L.
1983-01-01
The status of cryogenic refrigerator development intended for, or possibly applicable to, long life spacecraft-borne application is reviewed. Based on these efforts, the general development trends are identified. Using currently projected technology needs, the various trends are compared and evaluated. The linear drive, non-contacting bearing Stirling cycle refrigerator concept appears to be the best current approach that will meet the technology projection requirements for spacecraft-borne cryogenic refrigerators. However, a multiply redundant set of lightweight, moderate life, moderate reliability Stirling cycle cryogenic refrigerators using high-speed linear drive and sliding contact bearings may possibly suffice.
Can change in high-density lipoprotein cholesterol levels reduce cardiovascular risk?
Dean, Bonnie B; Borenstein, Jeff E; Henning, James M; Knight, Kevin; Merz, C Noel Bairey
2004-06-01
The cardiovascular risk reduction observed in many trials of lipid-lowering agents is greater than expected on the basis of observed low-density lipoprotein cholesterol (LDL-C) level reductions. Our objective was to explore the degree to which high-density lipoprotein cholesterol (HDL-C) level changes explain cardiovascular risk reduction. A systematic review identified trials of lipid-lowering agents reporting changes in HDL-C and LDL-C levels and the incidence of coronary heart disease (CHD). The observed relative risk reduction (RRR) in CHD morbidity and mortality rates was calculated. The expected RRR, given the treatment effect on total cholesterol level, was calculated for each trial with logistic regression coefficients from observational studies. The difference between observed and expected RRR was plotted against the change in HDL-C level, and a least-squares regression line was calculated. Fifty-one trials were identified. Nineteen statin trials addressed the association of HDL-C with CHD. Limited numbers of trials of other therapies precluded additional analyses. Among statin trials, therapy reduced total cholesterol levels as much as 32% and LDL-C levels as much as 45%. HDL-C level increases were <10%. Treatment effect on HDL-C levels was not a significant linear predictor of the difference in observed and expected CHD mortality rates, although we observed a trend in this direction (P =.08). Similarly, HDL-C effect was not a significant linear predictor of the difference between observed and expected RRRs for CHD morbidity (P =.20). Although a linear trend toward greater risk reduction was observed with greater effects on HDL-C, differences were not statistically significant. The narrow range of HDL-C level increases in the statin trials likely reduced our ability to detect a beneficial HDL-C effect, if present.
A Monte Carlo Uncertainty Analysis of Ozone Trend Predictions in a Two Dimensional Model. Revision
NASA Technical Reports Server (NTRS)
Considine, D. B.; Stolarski, R. S.; Hollandsworth, S. M.; Jackman, C. H.; Fleming, E. L.
1998-01-01
We use Monte Carlo analysis to estimate the uncertainty in predictions of total O3 trends between 1979 and 1995 made by the Goddard Space Flight Center (GSFC) two-dimensional (2D) model of stratospheric photochemistry and dynamics. The uncertainty is caused by gas-phase chemical reaction rates, photolysis coefficients, and heterogeneous reaction parameters which are model inputs. The uncertainty represents a lower bound to the total model uncertainty assuming the input parameter uncertainties are characterized correctly. Each of the Monte Carlo runs was initialized in 1970 and integrated for 26 model years through the end of 1995. This was repeated 419 times using input parameter sets generated by Latin Hypercube Sampling. The standard deviation (a) of the Monte Carlo ensemble of total 03 trend predictions is used to quantify the model uncertainty. The 34% difference between the model trend in globally and annually averaged total O3 using nominal inputs and atmospheric trends calculated from Nimbus 7 and Meteor 3 total ozone mapping spectrometer (TOMS) version 7 data is less than the 46% calculated 1 (sigma), model uncertainty, so there is no significant difference between the modeled and observed trends. In the northern hemisphere midlatitude spring the modeled and observed total 03 trends differ by more than 1(sigma) but less than 2(sigma), which we refer to as marginal significance. We perform a multiple linear regression analysis of the runs which suggests that only a few of the model reactions contribute significantly to the variance in the model predictions. The lack of significance in these comparisons suggests that they are of questionable use as guides for continuing model development. Large model/measurement differences which are many multiples of the input parameter uncertainty are seen in the meridional gradients of the trend and the peak-to-peak variations in the trends over an annual cycle. These discrepancies unambiguously indicate model formulation problems and provide a measure of model performance which can be used in attempts to improve such models.
Time-varying trends of global vegetation activity
NASA Astrophysics Data System (ADS)
Pan, N.; Feng, X.; Fu, B.
2016-12-01
Vegetation plays an important role in regulating the energy change, water cycle and biochemical cycle in terrestrial ecosystems. Monitoring the dynamics of vegetation activity and understanding their driving factors have been an important issue in global change research. Normalized Difference Vegetation Index (NDVI), an indicator of vegetation activity, has been widely used in investigating vegetation changes at regional and global scales. Most studies utilized linear regression or piecewise linear regression approaches to obtain an averaged changing rate over a certain time span, with an implicit assumption that the trend didn't change over time during that period. However, no evidence shows that this assumption is right for the non-linear and non-stationary NDVI time series. In this study, we adopted the multidimensional ensemble empirical mode decomposition (MEEMD) method to extract the time-varying trends of NDVI from original signals without any a priori assumption of their functional form. Our results show that vegetation trends are spatially and temporally non-uniform during 1982-2013. Most vegetated area exhibited greening trends in the 1980s. Nevertheless, the area with greening trends decreased over time since the early 1990s, and the greening trends have stalled or even reversed in many places. Regions with browning trends were mainly located in southern low latitudes in the 1980s, whose area decreased before the middle 1990s and then increased at an accelerated rate. The greening-to-browning reversals were widespread across all continents except Oceania (43% of the vegetated areas), most of which happened after the middle 1990s. In contrast, the browning-to-greening reversals occurred in smaller area and earlier time. The area with monotonic greening and browning trends accounted for 33% and 5% of the vegetated area, respectively. By performing partial correlation analyses between NDVI and climatic elements (temperature, precipitation and cloud cover) and analyzing the MEEMD-extracted trends of these climatic elements, we discussed possible driving factors of the time-varying trends of NDVI in several specific regions where trend reversals occurred.
Hu, Yin; Niu, Yong; Wang, Dandan; Wang, Ying; Holden, Brien A; He, Mingguang
2015-01-22
Structural changes of retinal vasculature, such as altered retinal vascular calibers, are considered as early signs of systemic vascular damage. We examined the associations of 5-year mean level, longitudinal trend, and fluctuation in fasting plasma glucose (FPG) with retinal vascular caliber in people without established diabetes. A prospective study was conducted in a cohort of Chinese people age ≥40 years in Guangzhou, southern China. The FPG was measured at baseline in 2008 and annually until 2012. In 2012, retinal vascular caliber was assessed using standard fundus photographs and validated software. A total of 3645 baseline nondiabetic participants with baseline and follow-up data on FPG for 3 or more visits was included for statistical analysis. The associations of retinal vascular caliber with 5-year mean FPG level, longitudinal FPG trend (slope of linear regression-FPG), and fluctuation (standard deviation and root mean square error of FPG) were analyzed using multivariable linear regression analyses. Multivariate regression models adjusted for baseline FPG and other potential confounders showed that a 10% annual increase in FPG was associated independently with a 2.65-μm narrowing in retinal arterioles (P = 0.008) and a 3.47-μm widening in venules (P = 0. 0.004). Associations with mean FPG level and fluctuation were not statistically significant. Annual rising trend in FPG, but not its mean level or fluctuation, is associated with altered retinal vasculature in nondiabetic people. Copyright 2015 The Association for Research in Vision and Ophthalmology, Inc.
Yoga as an adjunctive treatment for posttraumatic stress disorder: a randomized controlled trial.
van der Kolk, Bessel A; Stone, Laura; West, Jennifer; Rhodes, Alison; Emerson, David; Suvak, Michael; Spinazzola, Joseph
2014-06-01
More than a third of the approximately 10 million women with histories of interpersonal violence in the United States develop posttraumatic stress disorder (PTSD). Currently available treatments for this population have a high rate of incomplete response, in part because problems in affect and impulse regulation are major obstacles to resolving PTSD. This study explored the efficacy of yoga to increase affect tolerance and to decrease PTSD symptomatology. Sixty-four women with chronic, treatment-resistant PTSD were randomly assigned to either trauma-informed yoga or supportive women's health education, each as a weekly 1-hour class for 10 weeks. Assessments were conducted at pretreatment, midtreatment, and posttreatment and included measures of DSM-IV PTSD, affect regulation, and depression. The study ran from 2008 through 2011. The primary outcome measure was the Clinician-Administered PTSD Scale (CAPS). At the end of the study, 16 of 31 participants (52%) in the yoga group no longer met criteria for PTSD compared to 6 of 29 (21%) in the control group (n = 60, χ²₁ = 6.17, P = .013). Both groups exhibited significant decreases on the CAPS, with the decrease falling in the large effect size range for the yoga group (d = 1.07) and the medium to large effect size decrease for the control group (d = 0.66). Both the yoga (b = -9.21, t = -2.34, P = .02, d = -0.37) and control (b = -22.12, t = -3.39, P = .001, d = -0.54) groups exhibited significant decreases from pretreatment to the midtreatment assessment. However, a significant group × quadratic trend interaction (d = -0.34) showed that the pattern of change in Davidson Trauma Scale significantly differed across groups. The yoga group exhibited a significant medium effect size linear (d = -0.52) trend. In contrast, the control group exhibited only a significant medium effect size quadratic trend (d = 0.46) but did not exhibit a significant linear trend (d = -0.29). Thus, both groups exhibited significant decreases in PTSD symptoms during the first half of treatment, but these improvements were maintained in the yoga group, while the control group relapsed after its initial improvement. Yoga significantly reduced PTSD symptomatology, with effect sizes comparable to well-researched psychotherapeutic and psychopharmacologic approaches. Yoga may improve the functioning of traumatized individuals by helping them to tolerate physical and sensory experiences associated with fear and helplessness and to increase emotional awareness and affect tolerance. ClinicalTrials.gov identifier: NCT00839813. © Copyright 2014 Physicians Postgraduate Press, Inc.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Iranpanah, A.
1989-03-01
Lineaments on a series of edge-enhanced images (TM data) from a region around the Caspian Sea form a geomorphically significant linear trend along the major Caucasus-Kopeh Dagh fault line. This fault represents the line of collision between the Cimmerian continents and the Turan plate on the south and north, respectively. The lineament zone manifests a ramp structure that forms a relatively narrow topographic high in the Caspian Sea. Paleogeographic studies of the Caspian Sea suggest that the basin is part of the eastern Paratethys, which began to develop in the early Paleogene during the Alpine-Himalayan uplift. On the basis ofmore » the lineaments and associated geomorphic features, the Caspian Sea can be divided into southern, central, and the northern Caspian subbasins. The Caucasus-Kopeh Dagh fault line trends N80/degrees/W and separates the southern Caspian from the central subbasin, approximately along 40/degrees/N latitude. The boundary between the central and the northern subbasins is also a linear topographic high which trends N70/degrees/E and lies approximately at 44/degrees/N latitude. The southern and central subbasins have subequal areal extension covering 35.64% and the 36.63% of the whole sea, whereas the northern subbasin occupies only 27.73% of the basin.« less
Non-detection of HC11N towards TMC-1: constraining the chemistry of large carbon-chain molecules
NASA Astrophysics Data System (ADS)
Loomis, Ryan A.; Shingledecker, Christopher N.; Langston, Glen; McGuire, Brett A.; Dollhopf, Niklaus M.; Burkhardt, Andrew M.; Corby, Joanna; Booth, Shawn T.; Carroll, P. Brandon; Turner, Barry; Remijan, Anthony J.
2016-12-01
Bell et al. reported the first detection of the cyanopolyyne HC11N towards the cold dark cloud TMC-1; no subsequent detections have been reported towards any source. Additional observations of cyanopolyynes and other carbon-chain molecules towards TMC-1 have shown a log-linear trend between molecule size and column density, and in an effort to further explore the underlying chemical processes driving this trend, we have analysed Green Bank Telescope observations of HC9N and HC11N towards TMC-1. Although we find an HC9N column density consistent with previous values, HC11N is not detected and we derive an upper limit column density significantly below that reported in Bell et al. Using a state-of-the-art chemical model, we have investigated possible explanations of non-linearity in the column density trend. Despite updating the chemical model to better account for ion-dipole interactions, we are not able to explain the non-detection of HC11N, and we interpret this as evidence of previously unknown carbon-chain chemistry. We propose that cyclization reactions may be responsible for the depleted HC11N abundance, and that products of these cyclization reactions should be investigated as candidate interstellar molecules.
Santos, Taciana Mirella Batista Dos; Cardoso, Mirian Domingos; Pitangui, Ana Carolina Rodarti; Santos, Yasmim Gabriella Cardoso; Paiva, Saul Martins; Melo, João Paulo Ramos; Silva, Lygia Maria Pereira
2016-12-01
The scope of this study was to analyze the trend of completeness of the data on violence perpetrated against adolescents registered in the State of Pernambuco between 2009 and 2012. This involved a cross-sectional survey of 5,259 adolescents, who were the victims of violence reported in SINAN-VIVA of the Pernambuco State Health Department. Simple linear regression was used to investigate the trend of completeness of the variables. The percentages of completeness were considered to be dependent variables (Y) and the number of years as independent variables (X). The results show a significant increase of 204% in the number of notifications. However, of the 34 variables analyzed, 27 (79.4%) showed a stationary trend, 6 (17.6%) a downward trend, and only one variable (2.9%) an upward trend. Completeness was considered 'Very Poor' for the variables: Education (47.3%), Full Address (21.3%), Occurrence Time (38%) and Use of Alcohol by the Attacker (47%). Therefore, despite the large increase in the number of notifications, data quality continued to be compromised, hampering a more realistic analysis of this group.
Bariatric surgery trends: an 18-year report from the International Bariatric Surgery Registry.
Samuel, Isaac; Mason, Edward E; Renquist, Kathleen E; Huang, Yu-Hui; Zimmerman, M Bridget; Jamal, Mohammad
2006-11-01
The epidemic of morbid obesity has increased bariatric procedures performed. Trend analyses provide important information that may impact individual practices. Patient data from 137 surgeons were examined from 1987 to 2004 (41,860 patients) using Cochran-Armitage Trend test and Generalized Linear Model. Over an 18-year period, surgeon preference for combined restrictive-malabsorptive procedures increased from 33% to 94%, while simple gastric restriction decreased correspondingly (P < .0001). Surgeons per worksite doubled and cases per surgeon increased 71%. Laparoscopic procedures increased to 24%. The percentage of males, mean operative age, and initial body mass index (BMI) increased significantly (P < .0001). Postoperative hospital stay decreased from 5.0 to 3.9 days (P < .0001). The most common procedure in 2004 was Roux-en-Y gastric bypass (RYGB) (59%). Bariatric surgery patients are now older and heavier, length of stay is shorter, and the laparoscopic approach is more frequent. From 1987 to 2004, the general trend shows a clear preference for combined restrictive-malabsorptive operations.
Rising Intragenerational Occupational Mobility in the United States, 1969 to 2011
Jarvis, Benjamin F.; Song, Xi
2017-01-01
Despite the theoretical importance of intragenerational mobility and its connection to intergenerational mobility, no study since the 1970s has documented trends in intragenerational occupational mobility. The present article fills this intellectual gap by presenting evidence of an increasing trend in intragenerational mobility in the United States from 1969 to 2011. We decompose the trend using a nested occupational classification scheme that distinguishes between disaggregated micro-classes and progressively more aggregated meso-classes, macro-classes, and manual and nonmanual sectors. Log-linear analysis reveals that mobility increased across the occupational structure at nearly all levels of aggregation, especially after the early 1990s. Controlling for structural changes in occupational distributions modifies, but does not substantially alter, these findings. Trends are qualitatively similar for men and women. We connect increasing mobility to other macro-economic trends dating back to the 1970s, including changing labor force composition, technologies, employment relations, and industrial structures. We reassert the sociological significance of intragenerational mobility and discuss how increasing variability in occupational transitions within careers may counteract or mask trends in intergenerational mobility, across occupations and across more broadly construed social classes. PMID:28966346
Trends in mortality and biological stress in a medieval polish urban population.
Betsinger, Tracy K; DeWitte, Sharon
2017-12-01
Urbanization in pre-modern populations may have had a variety of consequences related to population crowding. However, research on the effects of urbanization have provided inconsistent results regarding the biological impact of this transition on human populations. The purpose of this study is to test the hypothesis that urbanization caused an increase in overall biological stress in a medieval (10th-13th centuries AD) Polish population. A human skeletal sample (n=164) was examined for the presence of porotic hyperostosis, cribra orbitalia, linear enamel hypoplasia, periosteal reaction, and specific infectious diseases. Prevalence rates were compared among three temporal samples: initial urbanization, early urbanization, and later urbanization. Results indicate no significant trends for any of the pathological conditions. Cox proportional hazards analyses, however, revealed a significant increase in the risk of death over time, which supports the hypothesis. These results reflect the necessity of using multiple analyses to address bioarchaeological questions. The lack of significant results from skeletal indicators may be due to an earlier urbanization trend in the population. This study illustrates that the association of urbanization with elevated biological stress is complicated and dependent on various factors, including culture and time period. Copyright © 2017 Elsevier Inc. All rights reserved.
Using Generalized Additive Models to Analyze Single-Case Designs
ERIC Educational Resources Information Center
Shadish, William; Sullivan, Kristynn
2013-01-01
Many analyses for single-case designs (SCDs)--including nearly all the effect size indicators-- currently assume no trend in the data. Regression and multilevel models allow for trend, but usually test only linear trend and have no principled way of knowing if higher order trends should be represented in the model. This paper shows how Generalized…
Trends in surface ozone over Europe, 1978-1990
NASA Technical Reports Server (NTRS)
Low, Pak Sum; Kelly, P. Michael; Davies, Trevor D.
1994-01-01
It has been suggested that surface ozone concentrations in rural areas of Europe have been increasing at a rate of 1 to 3 percent per year over the past two to three decades, presumably due to human influences (Feister and Warmbt, 1987; Bojkov, 1988; Penkett, 1989). Recently, we have analyzed surface ozone data from 20 European stations of differing character (remote, rural, suburban and urban) for a common period of 1978-1988 (Low et al., 1992). It was found that there were pronounced annual and seasonal variations in the linear trends in different areas, and there was no dominant region-wide trend. In spring and, most notably, summer, stations on the maritime fringe of the network generally exhibited negative trends whilst those located further into the continental interior exhibited positive trends. In winter, most of the stations in the network exhibited positive trends. Relatively few of these trends were statistically significant. This paper updates our earlier analysis by extending the data sets of the network up to the year 1990. The spatial variations in surface ozone trends over the extended period 1978-1990 are examined and discussed in comparison to the 1978-1988 patterns. The update confirms the overall conclusions of the earlier analysis, specifically that caution should be exercised in interpreting the results of trend analyses based on station data representative of a limited period of time and/or geographical area.
Sea level anomaly on the Patagonian continental shelf: Trends, annual patterns and geostrophic flows
Saraceno, M.; Piola, A. R.; Strub, P. T.
2016-01-01
Abstract We study the annual patterns and linear trend of satellite sea level anomaly (SLA) over the southwest South Atlantic continental shelf (SWACS) between 54ºS and 36ºS. Results show that south of 42°S the thermal steric effect explains nearly 100% of the annual amplitude of the SLA, while north of 42°S it explains less than 60%. This difference is due to the halosteric contribution. The annual wind variability plays a minor role over the whole continental shelf. The temporal linear trend in SLA ranges between 1 and 5 mm/yr (95% confidence level). The largest linear trends are found north of 39°S, at 42°S and at 50°S. We propose that in the northern region the large positive linear trends are associated with local changes in the density field caused by advective effects in response to a southward displacement of the South Atlantic High. The causes of the relative large SLA trends in two southern coastal regions are discussed as a function meridional wind stress and river discharge. Finally, we combined the annual cycle of SLA with the mean dynamic topography to estimate the absolute geostrophic velocities. This approach provides the first comprehensive description of the seasonal component of SWACS circulation based on satellite observations. The general circulation of the SWACS is northeastward with stronger/weaker geostrophic currents in austral summer/winter. At all latitudes, geostrophic velocities are larger (up to 20 cm/s) close to the shelf‐break and decrease toward the coast. This spatio‐temporal pattern is more intense north of 45°S. PMID:27840784
Search for Trends and Periodicities in Inter-hemispheric Sea Surface Temperature Difference
NASA Astrophysics Data System (ADS)
Rajesh, R.; Tiwari, R. K.
2018-02-01
Understanding the role of coupled solar and internal ocean dynamics on hemispheric climate variability is critical to climate modelling. We have analysed here 165 year long annual northern hemispheric (NH) and southern hemispheric (SH) sea surface temperature (SST) data employing spectral and statistical techniques to identify the imprints of solar and ocean-atmospheric processes, if any. We reconstructed the eigen modes of NH-SST and SH-SST to reveal non-linear oscillations superimposed on the monotonic trend. Our analysis reveals that the first eigen mode of NH-SST and SH-SST representing long-term trend of SST variability accounts for 15-23% variance. Interestingly, these components are matching with first eigen mode (99% variance) of the total solar irradiance (TSI) suggesting possible impact of solar activity on long-term SST variation. Furthermore, spectral analysis of SSA reconstructed signal revealed statistically significant periodicities of 63 ± 5, 22 ± 2, 10 ± 1, 7.6, 6.3, 5.2, 4.7, and 4.2 years in both NH-SST and SH-SST data. The major harmonics centred at 63 ± 5, 22 ± 2, and 10 ± 1 years are similar to solar periodicities and hence may represent solar forcing, while the components peaking at around 7.6, 6.3, 5.2, 4.7, and 4.2 years apparently falls in the frequency bands of El-Nino-Southern Oscillations linked to the oceanic internal processes. Our analyses also suggest evidence for the amplitude modulation of 9-11 and 21-22 year solar cycles, respectively, by 104 and 163 years in northern and southern hemispheric SST data. The absence of the above periodic oscillations in CO2 fails to suggest its role on observed inter-hemispheric SST difference. The cross-plot analysis also revealed strong influence of solar activity on linear trend of NH- and SH-SST in addition to small contribution from CO2. Our study concludes that (1) the long-term trends in northern and southern hemispheric SST variability show considerable synchronicity with cyclic warming and cooling phases and (2) the difference in cyclic forcing and non-linear modulations stemming from solar variability as a possible source of hemispheric SST differences.
Arctic Sea Ice Variability and Trends, 1979-2006
NASA Technical Reports Server (NTRS)
Parkinson, Claire L.; Cavalieri, Donald J.
2008-01-01
Analysis of Arctic sea ice extents derived from satellite passive-microwave data for the 28 years, 1979-2006 yields an overall negative trend of -45,100 +/- 4,600 km2/yr (-3.7 +/- 0.4%/decade) in the yearly averages, with negative ice-extent trends also occurring for each of the four seasons and each of the 12 months. For the yearly averages the largest decreases occur in the Kara and Barents Seas and the Arctic Ocean, with linear least squares slopes of -10,600 +/- 2,800 km2/yr (-7.4 +/- 2.0%/decade) and -10,100 +/- 2,200 km2/yr (-1.5 +/- 0.3%/decade), respectively, followed by Baffin Bay/Labrador Sea, with a slope of -8,000 +/- 2,000 km2/yr) -9.0 +/- 2.3%/decade), the Greenland Sea, with a slope of -7,000 +/- 1,400 km2/yr (-9.3 +/- 1.9%/decade), and Hudson Bay, with a slope of -4,500 +/- 900 km2/yr (-5.3 +/- 1.1%/decade). These are all statistically significant decreases at a 99% confidence level. The Seas of Okhotsk and Japan also have a statistically significant ice decrease, although at a 95% confidence level, and the three remaining regions, the Bering Sea, Canadian Archipelago, and Gulf of St. Lawrence, have negative slopes that are not statistically significant. The 28-year trends in ice areas for the Northern Hemisphere total are also statistically significant and negative in each season, each month, and for the yearly averages.
Martian lineaments from Mariner 6 and 7 photographs
NASA Technical Reports Server (NTRS)
Schultz, P. H.; Ingerson, F. E.
1973-01-01
Mariner 6 and 7 photographs were used to investigate the nature and importance of linear surface trends on Mars. Cross correlations of frequency-azimuth distributions of linear trends from different Mariner frames indicate that lineations not recognized as topographic features have a component of pseudoforms, probably introduced during digital reconstruction of the pictures. Similar statistical tests may aid in the analysis of surface trends from future satellites and space probes. The most reliable data were separated into photometrically defined provinces. Meridiani Sinus and Margaritifer Sinus display five major trends in common, which are interpreted as extensions of crustal weaknesses related to the enormous equatorial canyon revealed in Mariner 6 and 9 pictures. Alignments of crater wall segments generally match these trends and suggest structural control of crater plan. Crater chains, however, do not match these trends and are interpreted as secondary impacts. Rose diagrams of lineations in Deucalionis Regio exhibit much more complexity and are believed to reflect a better preserved or more complex geologic history.
Methane as a Diagnostic Tracer of Changes in the Brewer-Dobson Circulation of the Stratosphere
NASA Technical Reports Server (NTRS)
Remsberg, E. E.
2015-01-01
This study makes use of time series of methane (CH4/ data from the Halogen Occultation Experiment (HALOE) to detect whether there were any statistically significant changes of the Brewer-Dobson circulation (BDC) within the stratosphere during 1992-2005. The HALOE CH4 profiles are in terms of mixing ratio versus pressure altitude and are binned into latitude zones within the Southern Hemisphere and the Northern Hemisphere. Their separate time series are then analyzed using multiple linear regression (MLR) techniques. The CH4 trend terms for the Northern Hemisphere are significant and positive at 10 N from 50 to 7 hPa and larger than the tropospheric CH4 trends of about 3%decade(exp -1) from 20 to 7 hPa. At 60 N the trends are clearly negative from 20 to 7 hPa. Their combined trends indicate an acceleration of the BDC in the middle stratosphere of the Northern Hemisphere during those years, most likely due to changes from the effects of wave activity. No similar significant BDC acceleration is found for the Southern Hemisphere. Trends from HALOE H2O are analyzed for consistency. Their mutual trends with CH4 are anti-correlated qualitatively in the middle and upper stratosphere, where CH4 is chemically oxidized to H2O. Conversely, their mutual trends in the lower stratosphere are dominated by their trends upon entry to the tropical stratosphere. Time series residuals for CH4 in the lower mesosphere also exhibit structures that are anti-correlated in some instances with those of the tracer-like species HCl. Their occasional aperiodic structures indicate the effects of transport following episodic, wintertime wave activity. It is concluded that observed multi-year, zonally averaged distributions of CH4 can be used to diagnose major instances of wave-induced transport in the middle atmosphere and to detect changes in the stratospheric BDC.
Hazzard, Vivienne M; Hahn, Samantha L; Sonneville, Kendrin R
2017-08-01
To examine prevalence of weight misperception (incongruence between one's perceived weight status and one's actual weight status) and disordered weight control behaviors (DWCBs; unhealthy behaviors aiming to control or modify weight), associations between weight misperception and DWCBs, and temporal trends in prevalence and associations among adolescents with overweight and obesity from 1999 to 2013. Self-reported data from eight biennial cycles (1999-2013) of the cross-sectional national Youth Risk Behavior Survey were used in analyses restricted to respondents with overweight/obesity. Data on weight status perception, use of fasting, purging, and diet pills to control weight, sex, race/ethnicity, and grade in school were used in multivariate logistic regression models. Among U.S. high school students with overweight and obesity, no linear temporal trends were detected for prevalence of weight misperception, fasting, or purging between 1999 and 2013, while a significant linear decrease was observed for prevalence of diet pill use between 1999 and 2013 (b=-0.81, p<0.01). Using data pooled across 1999-2013, weight misperception predicted lower use of all DWCBs examined in this study among females and lower use of fasting to control weight among males. No significant changes over time in associations of weight misperception with fasting or purging were observed, though the association between weight misperception and diet pill use weakened somewhat across 1999-2013. In the context of increasing prevalence of overweight and obesity, weight misperception appears to be a robust protective factor for DWCBs. Copyright © 2017. Published by Elsevier Ltd.
Mesospheric temperature trends derived from standard phase-height measurements
NASA Astrophysics Data System (ADS)
Peters, Dieter H. W.; Entzian, Günter; Keckhut, Philippe
2017-10-01
New homogeneous time series of daily standard phase-height (SPH) and daily plasma scale-height (PSH) have been derived from a 50-year long-radio-wave measurement of the broadcasting station Allouis (France, 162 kHz). The signal was received at Kühlungsborn (54°N, 12°E, Mecklenburg, Germany) and the present series is a third release. The daily time series of SPH shows in its spectrum dominant modes which are typical for the solar cycle (SC), for El Niño-Southern Oscillation (ENSO) and for quasi-biannual oscillation (QBO), indicating solar and lower atmospheric influences. Surprisingly, the time series of daily PSH shows a band of dominant cycles larger than 16 years. In order to exclude the influence of the winter anomaly in the determination of column-integrated mesospheric temperature trends the phase-height-temperature procedure is confined to summer months. The derived thickness temperature of the mesosphere decreased statistically significant over the period 1959-2008 after pre-whitening with summer mean of solar sun spot numbers. The trend value is in the order of about -1.05 K/decade if the stratopause trend is excluded. The linear regression is more pronounced, -1.35 K/decade for the period of 1963-1985 (2 SCs), but weaker, -0.51 K/decade during 1986-2008 (last 2 SCs). The linear regression is in very good agreement with a mean column-integrated mesospheric trend derived from OHP-Lidar temperatures on a monthly mean basis for the last two SCs. This clearly shows that the thickness temperature of the mesosphere derived from phase-height measurement is a useful proxy for the long-term summer temperature change in the mesosphere from 1959 until 2008.
New Trends in Educational Lighting Systems.
ERIC Educational Resources Information Center
Murphy, Peter
2001-01-01
Explores technological trends for improving campus lighting, including the use of direct-indirect suspended fluorescent lighting, suspended linear lighting, high-efficiency optical systems, and occupancy and daylight sensors. (GR)
NASA Astrophysics Data System (ADS)
Banzhaf, S.; Schaap, M.; Kranenburg, R.; Manders, A. M. M.; Segers, A. J.; Visschedijk, A. J. H.; Denier van der Gon, H. A. C.; Kuenen, J. J. P.; van Meijgaard, E.; van Ulft, L. H.; Cofala, J.; Builtjes, P. J. H.
2015-04-01
In this study we present a dynamic model evaluation of chemistry transport model LOTOS-EUROS (LOng Term Ozone Simulation - EURopean Operational Smog) to analyse the ability of the model to reproduce observed non-linear responses to emission changes and interannual variability of secondary inorganic aerosol (SIA) and its precursors over Europe from 1990 to 2009. The 20 year simulation was performed using a consistent set of meteorological data provided by RACMO2 (Regional Atmospheric Climate MOdel). Observations at European rural background sites have been used as a reference for the model evaluation. To ensure the consistency of the used observational data, stringent selection criteria were applied, including a comprehensive visual screening to remove suspicious data from the analysis. The LOTOS-EUROS model was able to capture a large part of the seasonal and interannual variability of SIA and its precursors' concentrations. The dynamic evaluation has shown that the model is able to simulate the declining trends observed for all considered sulfur and nitrogen components following the implementation of emission abatement strategies for SIA precursors over Europe. Both the observations and the model show the largest part of the decline in the 1990s, while smaller concentration changes and an increasing number of non-significant trends are observed and modelled between 2000 and 2009. Furthermore, the results confirm former studies showing that the observed trends in sulfate and total nitrate concentrations from 1990 to 2009 are lower than the trends in precursor emissions and precursor concentrations. The model captured well these non-linear responses to the emission changes. Using the LOTOS-EUROS source apportionment module, trends in the formation efficiency of SIA have been quantified for four European regions. The exercise has revealed a 20-50% more efficient sulfate formation in 2009 compared to 1990 and an up to 20% more efficient nitrate formation per unit nitrogen oxide emission, which added to the explanation of the non-linear responses. However, we have also identified some weaknesses in the model and the input data. LOTOS-EUROS underestimates the observed nitrogen dioxide concentrations throughout the whole time period, while it overestimates the observed nitrogen dioxide concentration trends. Moreover, model results suggest that the emission information of the early 1990s used in this study needs to be improved concerning magnitude and spatial distribution.
Detection of temperature trends within the course of the year using "shifting subseasons"
NASA Astrophysics Data System (ADS)
Cahynova, Monika; Pokorna, Lucie
2015-04-01
Recent global warming has not been ubiquitous - there are seasons, regions, and time periods with clearly discernible zero or downward air temperature trends. Regions that are not warming or are even cooling - also known as "warming holes" - have been previously detected mainly in autumn in the second half of the 20th century in large parts of North America as well as in Central and Eastern Europe. Daily maximum and minimum temperature (TX and TN, respectively) and daily temperature range (DTR) at 136 stations in Europe during the period 1961-2000 are employed to precisely locate the seasonal and subseasonal trends within the course of the year. Linear trends are calculated for moving "subseasons" of differing lengths (10, 20, 30, 60, and 90 days), each shifted by one day. Cluster analysis of the annual course of "shifting trends" reveals relatively well-defined regions with similar trend behavior. Over most of Europe, the observed warming is greatest in winter, and the highest trend magnitudes are reached by TN in Eastern Europe. Two regions stand out: in Iceland and the Eastern Mediterranean, the trends during the year are weak, positive in summer and mostly negative in winter, reaching statistical significance at only few stations. Significant autumn cooling centered on mid-November was found in Eastern and Southeastern Europe for both TX and TN; in many other regions trends are close to zero in the same period. Other clearly non-warming (or even cooling) periods occur in Western and Central Europe in February, April, and late June. Trends of DTR are largely inconclusive and no general picture can be drawn. Our results suggest that using different time scales, apart from the conventional three-month seasons or common months, is highly desirable for a proper location of trends within the course of the year.
Aerosol optical depth trend over the Middle East
NASA Astrophysics Data System (ADS)
Klingmueller, Klaus; Pozzer, Andrea; Metzger, Swen; Abdelkader, Mohamed; Stenchikov, Georgiy; Lelieveld, Jos
2016-04-01
We use the combined Dark Target/Deep Blue aerosol optical depth (AOD) satellite product of the Moderate-resolution Imaging Spectroradiometer (MODIS) collection 6 to study trends over the Middle East between 2000 and 2015. Our analysis corroborates a previously identified positive AOD trend over large parts of the Middle East during the period 2001 to 2012. By relating the annual AOD to precipitation, soil moisture and surface wind, being the main factors controlling the dust cycle, we identify regions where these attributes are significantly correlated to the AOD over Saudi Arabia, Iraq and Iran. The Fertile Crescent turns out to be of prime importance for the AOD trend over these countries. Using multiple linear regression we show that AOD trend and interannual variability can be attributed to the above mentioned dust cycle parameters, confirming that the AOD increase is predominantly driven by dust. In particular, the positive AOD trend relates to a negative soil moisture trend. This suggests that increasing temperature and decreasing relative humidity in the last decade have promoted soil drying, leading to increased dust emissions and AOD; consequently an AOD increase is expected due to climate change. Based on simulations using the ECHAM/MESSy atmospheric chemistry-climate model (EMAC), we interpret the correlations identified in the observational data in terms of causal relationships.
Diatom diversity in chronically versus episodically acidified adirondack streams
Passy, S.I.; Ciugulea, I.; Lawrence, G.B.
2006-01-01
The relationship between algal species richness and diversity, and pH is controversial. Furthermore, it is still unknown how episodic stream acidification following atmospheric deposition affects species richness and diversity. Here we analyzed water chemistry and diatom epiphyton dynamics and showed their contrasting behavior in chronically vs. episodically acidic streams in the Adirondack region. Species richness and diversity were significantly higher in the chronically acidic brown water stream, where organic acidity was significantly higher and the ratio of inorganic to organic monomeric aluminum significantly lower. Conversely, in the episodically acidic clear water stream, the inorganic acidity and pH were significantly higher and the diatom communities were very species-poor. This suggests that episodic acidification in the Adirondacks may be more stressful for stream biota than chronic acidity. Strong negative linear relationships between species diversity, Eunotia exigua, and dissolved organic carbon against pH were revealed after the influence of non-linear temporal trends was partialled out using a novel way of temporal modeling. ?? 2006 WILEY-VCH Verlag GmbH & Co. KGaA.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bartolac, S; Letourneau, D; University of Toronto, Toronto, Ontario
Purpose: Application of process control theory in quality assurance programs promises to allow earlier identification of problems and potentially better quality in delivery than traditional paradigms based primarily on tolerances and action levels. The purpose of this project was to characterize underlying seasonal variations in linear accelerator output that can be used to improve performance or trigger preemptive maintenance. Methods: Review of runtime plots of daily (6 MV) output data acquired using in house ion chamber based devices over three years and for fifteen linear accelerators of varying make and model were evaluated. Shifts in output due to known interventionsmore » with the machines were subtracted from the data to model an uncorrected scenario for each linear accelerator. Observable linear trends were also removed from the data prior to evaluation of periodic variations. Results: Runtime plots of output revealed sinusoidal, seasonal variations that were consistent across all units, irrespective of manufacturer, model or age of machine. The average amplitude of the variation was on the order of 1%. Peak and minimum variations were found to correspond to early April and September, respectively. Approximately 48% of output adjustments made over the period examined were potentially avoidable if baseline levels had corresponded to the mean output, rather than to points near a peak or valley. Linear trends were observed for three of the fifteen units, with annual increases in output ranging from 2–3%. Conclusion: Characterization of cyclical seasonal trends allows for better separation of potentially innate accelerator behaviour from other behaviours (e.g. linear trends) that may be better described as true out of control states (i.e. non-stochastic deviations from otherwise expected behavior) and could indicate service requirements. Results also pointed to an optimal setpoint for accelerators such that output of machines is maintained within set tolerances and interventions are required less frequently.« less
NASA Technical Reports Server (NTRS)
Blackstone, D. L., Jr.
1972-01-01
The author has identified the following significant results. Structurally linear elements in the vicinity of the Rock Springs Uplift, Sweetwater County, Wyoming are reported for the first time. One element trends N 40 deg W near Farson, Wyoming and the other N 65 deg E from Rock Springs. These elements confirm the block-like or mosaic pattern of major structural elements in Wyoming.
Negative psychological aspects and survival in lung cancer patients.
Nakaya, Naoki; Saito-Nakaya, Kumi; Akechi, Tatsuo; Kuriyama, Shinichi; Inagaki, Masatoshi; Kikuchi, Nobutaka; Nagai, Kanji; Tsugane, Shoichiro; Nishiwaki, Yutaka; Tsuji, Ichiro; Uchitomi, Yosuke
2008-05-01
We conducted a prospective cohort study in Japan to investigate associations between negative psychological aspects and cancer survival. Between July 1999 and July 2004, a total of 1178 lung cancer patients were enrolled. The questionnaire asked about socioeconomic variables, smoking status, clinical symptoms, and psychological aspects after diagnosis. Negative psychological aspects were assessed for the subscales of helplessness/hopelessness and depression. Clinical stage, performance status (PS), and histologic type were obtained from medical charts. The subjects were followed up until December 2004, and 686 had died. A Cox regression model was used to estimate the hazards ratio (HR) of all-cause mortality. After adjustment for socioeconomic variables and smoking status in addition to sex, age, and histologic type, both helplessness/hopelessness and depression subscales showed significant linear positive associations with the risk of mortality (p for trend<0.001 for both). However, after adjustment for clinical state variables in addition to sex, age, and histologic type, these significant linear positive associations were no longer observed (p for trend=0.41 and 0.26, respectively). Our data supported the hypothesis that the association between helplessness/hopelessness and depression and the risk of mortality among lung cancer patients was largely confounded by clinical state variables including clinical stage, PS, and clinical symptoms. (c) 2007 John Wiley & Sons, Ltd.
Gender trends in dental leadership and academics: a twenty-two-year observation.
Yuan, Judy Chia-Chun; Lee, Damian J; Kongkiatkamon, Suchada; Ross, Sasha; Prasad, Soni; Koerber, Anne; Sukotjo, Cortino
2010-04-01
The purpose of this study was to examine gender disparities in dental leadership and academics in the United States. Nine journals that represent the dental specialties and high published impact factors were selected to analyze the percentage of female dentists' first and senior authorship for the years 1986, 1990, 1995, 2000, 2005, and 2008. Data on appointment status and female deanship were collected from the American Dental Association (ADA) survey, and the trends were studied. The proportion of female presidents in ADA-recognized specialty organizations was also calculated. Overall, the increase in first female authorship was not statistically significant, but the increase of last female authorship was statistically significant in a linear trend over the years. The percentage of tenured female faculty members and female deans in U.S. dental schools increased by factors of 1.7 and 9, respectively, during the study period. However, female involvement in professional organizations was limited. Findings from this study indicate that female participation in authorship and leadership has increased over time. Nevertheless, females are still a minority in dental academics and leadership.
Ghani, Khurshid R; Sammon, Jesse D; Karakiewicz, Pierre I; Sun, Maxine; Bhojani, Naeem; Sukumar, Shyam; Peabody, James O; Menon, Mani; Trinh, Quoc-Dien
2013-07-01
To determine trends in demographics and treatment for inpatient upper urinary tract calculi in the USA using a population-based cohort. All patients with a primary or secondary diagnosis of kidney or ureteric calculus between 1999 and 2009 in the US Nationwide Inpatient Sample were extracted and weighted. Temporal trend analyses were used to determine trends in gender, race and age presentation, as well as utilization rates of interventions. Temporal trends were quantified using the estimated annual percent change (EAPC) using least squares linear regression analysis. Overall, 2 109 455 patients were hospitalized with upper urinary tract calculi over the 11-year period. The majority of admissions were for ureteric calculi (63.4%). Admissions for renal calculus increased by 12.1% during the study period (EAPC + 0.92%, P = 0.039, 95% CI: 0.17-1.66), whilst discharges for ureteric calculus remained stable. A significant increase (25.4%) in hospitalizations for women was found (EAPC + 2.21%, P < 0.001, 95% CI: 1.40-3.03); by 2006, more women than men were admitted to hospital (95 953 vs. 94 556, respectively). There were significant increases in hospitalization for black, Hispanic and older patients. Significant changes in the use of all studied interventions were found except for ureteroscopy, extracorporeal shockwave lithotripsy and nephrectomy. In this nationally representative sample of inpatient discharges, significant increases were found in admissions for renal compared with ureteric calculi, and for black, Hispanic and older patients. With regard to surgical intervention, the largest increase was found in the use of procedures for kidney calculi. Women now comprise the majority in the inpatient management of stone disease. © 2013 BJU International.
Trends in thermal discomfort indices over western coastal cities of India
NASA Astrophysics Data System (ADS)
Desai, Manasi S.; Dhorde, Amit G.
2018-02-01
The present research aimed at analyzing temporal trends in thermal discomfort indices for a period of 46 years from 1969 to 2014 over western coastal region of India for seven urban centers during the months of pre-monsoon and monsoon seasons. Direct thermal discomfort indices employed for this purpose were thermo-hygrometric index (THI) and heat index (HI). Statistical techniques applied for obtaining temporal trends were linear regression model and Mann-Kendall (MK) rank test. Statistical significance of the obtained trends was evaluated at 95% confidence level. Sequential MK (SQ-MK) test was used for change point detection. To investigate actual incidences of thermal discomfort, daily index values were averaged for standard meteorological weeks (SMWs) over the study period and decadal percentage of thermal discomfort during SMWs was estimated. Trend analysis of selected meteorological parameters such as dry bulb temperature (DBT), wet bulb temperature (WBT), relative humidity (RH), and wind speed (WS) were investigated, which might be responsible for variation in thermal discomfort over the period. The results obtained depicted significant increase in thermal discomfort over the cities located on the southern part of west coast, while significant increase was observed during monsoon season months compared to pre-monsoon season. Decadal variation in percentage of SMWs falling in various discomfort categories was studied. At majority of the stations, moderate and high-risk SMWs have increased over the last two decades. The results of change point detection for THI and HI denoted significant increase at most of the stations after 1990s. The study validates increase in thermal discomfort vulnerability, particularly at thriving urban centers of western coastal region of India.
Racial and Ethnic Trends in Sudden Unexpected Infant Deaths: United States, 1995-2013.
Parks, Sharyn E; Erck Lambert, Alexa B; Shapiro-Mendoza, Carrie K
2017-06-01
Immediately after the 1994 Back-to-Sleep campaign, sudden unexpected infant death (SUID) rates decreased dramatically, but they have remained relatively stable (93.4 per 100 000 live births) since 2000. In this study, we examined trends in SUID rates and disparities by race/ethnicity since the Back-to-Sleep campaign. We used 1995-2013 US period-linked birth-infant death data to evaluate SUID rates per 100 000 live births by non-Hispanic white (NHW), non-Hispanic black (NHB), Hispanic, American Indian/Alaska Native, and Asian/Pacific Islander racial/ethnic groupings. To examine racial/ethnic disparities, we calculated rate ratios with NHWs as the referent group. Unadjusted linear regression was used to evaluate trends ( P < .05) in rates and rate ratios. The distribution and rates of SUID by demographic and birth characteristics were compared for 1995-1997 and 2011-2013, and χ 2 tests were used to evaluate significance. From 1995 to 2013, SUID rates were consistently highest for American Indian/Alaska Natives, followed by NHBs. The rate for NHBs decreased significantly, whereas the rate for NHWs also declined, but not significantly. As a result, the disparity between NHWs and NHBs narrowed slightly. The SUID rates for Hispanics and Asian/Pacific Islanders were lower than the rates for NHWs and showed a significant decrease, resulting in an increase in their advantage over NHWs. Each racial/ethnic group showed a unique trend in SUID rates since the Back-to-Sleep campaign. When implementing risk-reduction strategies, it is important to consider these trends in targeting populations for prevention and developing culturally appropriate approaches for racial/ethnic communities. Copyright © 2017 by the American Academy of Pediatrics.
Racial and Ethnic Trends in Sudden Unexpected Infant Deaths: United States, 1995–2013
Parks, Sharyn E.; Erck Lambert, Alexa B.; Shapiro-Mendoza, Carrie K.
2017-01-01
BACKGROUND AND OBJECTIVES Immediately after the 1994 Back-to-Sleep campaign, sudden unexpected infant death (SUID) rates decreased dramatically, but they have remained relatively stable (93.4 per 100 000 live births) since 2000. In this study, we examined trends in SUID rates and disparities by race/ethnicity since the Back-to-Sleep campaign. METHODS We used 1995–2013 US period-linked birth-infant death data to evaluate SUID rates per 100 000 live births by non-Hispanic white (NHW), non-Hispanic black (NHB), Hispanic, American Indian/Alaska Native, and Asian/Pacific Islander racial/ethnic groupings. To examine racial/ethnic disparities, we calculated rate ratios with NHWs as the referent group. Unadjusted linear regression was used to evaluate trends (P < .05) in rates and rate ratios. The distribution and rates of SUID by demographic and birth characteristics were compared for 1995–1997 and 2011–2013, and χ2 tests were used to evaluate significance. RESULTS From 1995 to 2013, SUID rates were consistently highest for American Indian/Alaska Natives, followed by NHBs. The rate for NHBs decreased significantly, whereas the rate for NHWs also declined, but not significantly. As a result, the disparity between NHWs and NHBs narrowed slightly. The SUID rates for Hispanics and Asian/Pacific Islanders were lower than the rates for NHWs and showed a significant decrease, resulting in an increase in their advantage over NHWs. CONCLUSIONS Each racial/ethnic group showed a unique trend in SUID rates since the Back-to-Sleep campaign. When implementing risk-reduction strategies, it is important to consider these trends in targeting populations for prevention and developing culturally appropriate approaches for racial/ethnic communities. PMID:28562272
Further study on the solar activity variation of daytime NmF2
NASA Astrophysics Data System (ADS)
Chen, Yiding; Liu, Libo
2010-12-01
The ionosonde observations in the East Asia-Australia sector are collected to further investigate the solar activity variation of daytime (0800 ˜ 1600 LT) NmF2. The linear increase rate of NmF2 with F10.7 at lower solar activity levels is remarkably dependent on latitude, season, and local time. The rate is largest in equinoxes (with an equinoctial asymmetry) and higher in the morning (afternoon) in local winter (summer) at geomagnetic midlatitudes; particularly, the maximum rates in local winter are obviously larger than those in local summer at northern midlatitudes. In the equatorial ionization anomaly (EIA) crest regions, the rates in equinoxes and December (June) solstice are remarkably higher than those in June (December) solstice at the northern (southern) EIA crest, and the rate grows from the morning sector to the afternoon sector. The variation trend of NmF2 with F10.7 also shows latitudinal, seasonal, and local time dependences. The saturation effect dominates in all seasons in the EIA regions; at midlatitudes, NmF2 nearly increases linearly with F10.7 in local winter so that a linear fit is a good approximation for NmF2 modeling, while the saturation effect still dominates in other seasons. The saturation effect is more significant in the afternoon, and the strongest saturation effect appears at the EIA crest latitudes in equinox afternoon. Discussions indicate that the variations of neutral atmosphere and hmF2 are responsible for the seasonal and local time dependences of the linear increase rate of NmF2 with F10.7 at midlatitudes, and the seasonal variation of neutral atmosphere is the primary reason for the seasonal dependence of the variation trend of NmF2 with F10.7, while dynamics processes are the more important factors controlling the linear increase rate and the variation trend of NmF2 with F10.7 at low latitudes. Furthermore, dynamics processes are important for the saturation effect, and the fountain effect is related to the strongest saturation effect appearing at the EIA crests.
NASA Astrophysics Data System (ADS)
Gado, Tamer A.; Nguyen, Van-Thanh-Van
2016-04-01
This paper, the second of a two-part paper, investigates the nonstationary behaviour of flood peaks in Quebec (Canada) by analyzing the annual maximum flow series (AMS) available for the common 1966-2001 period from a network of 32 watersheds. Temporal trends in the mean of flood peaks were examined by the nonparametric Mann-Kendall test. The significance of the detected trends over the whole province is also assessed by a bootstrap test that preserves the cross-correlation structure of the network. Furthermore, The LM-NS method (introduced in the first part) is used to parametrically model the AMS, investigating its applicability to real data, to account for temporal trends in the moments of the time series. In this study two probability distributions (GEV & Gumbel) were selected to model four different types of time-varying moments of the historical time series considered, comprising eight competing models. The selected models are: two stationary models (GEV0 & Gumbel0), two nonstationary models in the mean as a linear function of time (GEV1 & Gumbel1), two nonstationary models in the mean as a parabolic function of time (GEV2 & Gumbel2), and two nonstationary models in the mean and the log standard deviation as linear functions of time (GEV11 & Gumbel11). The eight models were applied to flood data available for each watershed and their performance was compared to identify the best model for each location. The comparative methodology involves two phases: (1) a descriptive ability based on likelihood-based optimality criteria such as the Bayesian Information Criterion (BIC) and the deviance statistic; and (2) a predictive ability based on the residual bootstrap. According to the Mann-Kendall test and the LM-NS method, a quarter of the analyzed stations show significant trends in the AMS. All of the significant trends are negative, indicating decreasing flood magnitudes in Quebec. It was found that the LM-NS method could provide accurate flood estimates in the context of nonstationarity. The results have indicated the importance of taking into consideration the nonstationary behaviour of the flood series in order to improve the quality of flood estimation. The results also provided a general impression on the possible impacts of climate change on flood estimation in the Quebec province.
Miller, Todd; Mull, Stephanie; Aragon, Alan Albert; Krieger, James; Schoenfeld, Brad Jon
2018-01-01
The purpose of this study was to determine the effects of resistance training only (RT; n = 10), dietary intervention only (DIET; n = 10), resistance training plus diet (RT+DIET; n = 10), and control (CON; n = 10) on body composition and resting metabolic rate (RMR) in a cohort of 40 premenopausal female volunteers. Subjects in DIET and RT+DIET were provided with daily macronutrient and calorie goals based on DXA and RMR tests, with protein maintained at 3.1 g/kg/day. Subjects in the RT and RT+DIET groups performed a supervised progressive RT program consisting of exercises for all the major muscle groups of the body. Results showed a significant month-by-group interaction for change in fat mass with no significant linear trend for control. The three treatment groups all showed significant linear decreases in fat mass, but the slope of the decrease became progressively steeper from the RT, to DIET, to RT+DIET. A significant linear increase for lean mass was seen for resistance training only. There was a nonsignificant increase in RMR in all groups from Month 0 to Month 4 but no significant month by group interaction. In conclusion, significant reductions in fat mass were achieved by all experimental groups, but results were maximized by RT+DIET. Only the RT group showed significant increases in lean mass.
Using satellite measurements of N2O to remove dynamical variability from HCl measurements
NASA Astrophysics Data System (ADS)
Stolarski, Richard S.; Douglass, Anne R.; Strahan, Susan E.
2018-04-01
Column HCl measurements show deviations from the expected slow decline following the regulation of chlorine-containing compounds by the Montreal Protocol. We use the simultaneous measurements of N2O and HCl by the Microwave Limb Sounder (MLS) instrument on the Aura satellite to examine this problem. We find that the use of N2O measurements at a specific altitude to represent the impact of dynamical variability on HCl results in a derived linear trend in HCl that is negative (ranging from -2.5 to 5.3 % decade-1) at all altitudes between 68 and 10 hPa. These trends are at or near 2σ statistical significance at all pressure levels between 68 and 10 hPa. This shows that analysis of simultaneous measurements of several constituents is a useful approach to identify small trends from data records that are strongly influenced by dynamical interannual variability.
Centola, G M; Blanchard, A; Demick, J; Li, S; Eisenberg, M L
2016-03-01
Controversy exists regarding stability of semen quality over time with papers reporting decrease, increase or stable parameters in heterogeneous populations. The current study examined semen parameters of young adult men from 2003 to 2013 at an urban U.S. sperm bank. Semen parameters were analyzed before and after cryopreservation for a total of 9425 specimens from 489 individuals. Demographic information was obtained from a social and medical history questionnaire. Following 2-3 days abstinence, the specimens were collected at the laboratory and assessed by uniform technicians and techniques. The data were analyzed using generalized linear regression after adjustment for age, days of abstinence, for repeated samples, as well as by the Cochran-Armitage trend test. The within variability was accounted for by the repeated measures model. All p values were two-sided with p < 0.05 considered significant. There was a significant decline in sperm concentration (-3.55, 95% CI -4.87, -2.23; p < 0.001), total motility (-1.23, 95% CI -1.65, -0.82; p < 0.001), total count (-10.75, 95% CI -15.95, -5.54; p < 0.001) and total motile count (-9.43, 95% CI -13.14, -5.73; p < 0.001). There was no significant change in semen volume (0.03, 95% CI -0.02, 0.09; p = 0.2). The post-thaw total motility significantly (-2.30, 95% CI -2.72, -1.87; p < 0.001) decreased with time. Importantly, demographic and lifestyle factors were stable or improved over the study period. There was a decline in age (p(trend) = 0.003) and alcohol use (p(trend) = 0.005) and an increase in college GPA (Grade Point Average) (p(trend) = 0.02). BMI (p(trend) = 0.73), educational attainment (p(trend) = 0.2), race/ethnicity (p(trend) = 0.53), and lifestyle habits (weekly exercise, p(trend) = 0.21; smoking, p(trend) = 0.99; marital status, p(trend) = 0.85) remained constant. Uniform technicians and techniques over the study period make measurement bias unlikely. This report demonstrates a decline in semen quality among young adult men in the Boston area who were attending or completed a college education during the past 10 years, and requires further study. © 2016 American Society of Andrology and European Academy of Andrology.
Bellinger, Adam S.; Elliott, Sean P.; Yang, Liu; Wei, John T.; Saigal, Christopher S.; Smith, Alexandria; Wilt, Timothy J.; Strope, Seth A.
2012-01-01
Introduction Benign prostatic hyperplasia (BPH) creates significant expenses for the Medicare program. We sought to determine trends in expenditures for BPH evaluative testing after urologist consultation, and place these trends in the context of overall Medicare expenditures. Methods Using a 5% national sample of Medicare beneficiaries from 2000 to 2007, we developed a cohort of men with claims for new visits to urologists for diagnoses consistent with symptomatic BPH (n=40,253). We assessed trends in initial expenditures (within 12 months of diagnosis; inflation and geography adjusted) by categories of evaluative tests derived from the 2003 AUA Guideline on the Management of BPH. Using governmental reports on Medicare expenditures, trends in BPH expenditures were compared to overall and imaging-specific Medicare expenditures. Comparisons were assessed by Z-tests and regression analysis for linear trends as appropriate. Results Between 2000 and 2007 inflation adjusted total Medicare expenditure per patient for the initial evaluation of BPH patients seen by urologists increased from $255.44 to $343.98 (p<0.0001). Increases in BPH related imaging (55%), were significantly less than increases in overall Medicare expenditures on imaging (104%; p<0.001). The 35% increase in per patient expenditures for BPH was significantly lower than the increase in overall Medicare expenditure per enrollee (45%; p=0.0.0015). Conclusion From 2000 to 2007, inflation adjusted expenditures on BPH related evaluations increased. This growth was slower than overall growth in Medicare expenditures, and increases in imaging expenditures related to BPH were restrained compared to the Medicare program as a whole. PMID:22425128
Detecting trends in raptor counts: power and type I error rates of various statistical tests
Hatfield, J.S.; Gould, W.R.; Hoover, B.A.; Fuller, M.R.; Lindquist, E.L.
1996-01-01
We conducted simulations that estimated power and type I error rates of statistical tests for detecting trends in raptor population count data collected from a single monitoring site. Results of the simulations were used to help analyze count data of bald eagles (Haliaeetus leucocephalus) from 7 national forests in Michigan, Minnesota, and Wisconsin during 1980-1989. Seven statistical tests were evaluated, including simple linear regression on the log scale and linear regression with a permutation test. Using 1,000 replications each, we simulated n = 10 and n = 50 years of count data and trends ranging from -5 to 5% change/year. We evaluated the tests at 3 critical levels (alpha = 0.01, 0.05, and 0.10) for both upper- and lower-tailed tests. Exponential count data were simulated by adding sampling error with a coefficient of variation of 40% from either a log-normal or autocorrelated log-normal distribution. Not surprisingly, tests performed with 50 years of data were much more powerful than tests with 10 years of data. Positive autocorrelation inflated alpha-levels upward from their nominal levels, making the tests less conservative and more likely to reject the null hypothesis of no trend. Of the tests studied, Cox and Stuart's test and Pollard's test clearly had lower power than the others. Surprisingly, the linear regression t-test, Collins' linear regression permutation test, and the nonparametric Lehmann's and Mann's tests all had similar power in our simulations. Analyses of the count data suggested that bald eagles had increasing trends on at least 2 of the 7 national forests during 1980-1989.
Epidemiology of imported malaria among children and young adults in Barcelona (1990-2008)
2011-01-01
Background Increasing international travel and migration is producing changes in trends in infectious diseases, especially in children from many European cities. The objective of this study was to describe the epidemiology and determine the trends of imported malaria in patients under 20 years old in the city of Barcelona, Spain, during an 18-year period. Methods The study included malaria cases that were laboratory confirmed and reported to the malaria register at the Public Health Agency of Barcelona from 1990 to 2008, residing in Barcelona and less than 20 years old. Patients were classified as natives (born in Spain) or immigrants. Differences in the distribution of demographic, clinical characteristics, and incidence per 100,000 person-year evolution were analysed. Natives and immigrants were compared by logistic regression by calculating the odds ratio (OR) with a 95% confidence interval (CI) and Chi-square for a linear trend (p < 0.05). Results Of the total 174 cases, 143 (82.1%) were immigrants, 100 (57.5%) were female, 121 (69.5%) Plasmodium falciparum, and 108 (62.1%) were visiting friends and relatives (VFR) as the reason for travel. Among the immigrants, 99 (67.8%) were from Equatorial Guinea. Immigrant cases more frequently travelled to Africa than natives (p = 0.02). The factors associated with imported malaria among immigrant residents was travelling for VFR (OR: 6.2 CI 1.9-20.2) and age 15-19 (OR: 3.7 CI 1-13.3). The incidence increased from 1990 to 1999 (p < 0.001) and decreased from 2000 to 2008 (p = 0.01), although the global linear trend was not statistically significant (p = 0.41). The fatality rate was 0.5%. Conclusions The majority of cases of malaria in population less than 20 years in Barcelona were immigrants, travelling to Africa for VFR and Plasmodium falciparum was most frequently detected. The trend analysis of the entire study period did not show a statistically significant decline. It is recommended to be aware of malaria, especially among children of immigrants who travel to their parent's home country for VFR. Better access to pre travel advice should be provided. PMID:22118531
Epidemiology of imported malaria among children and young adults in Barcelona (1990-2008).
Garcia-Villarrubia, Mireia; Millet, Juan-Pablo; de Olalla, Patricia Garcia; Gascón, Joaquim; Fumadó, Victoria; i Prat, Jordi Gómez; Treviño, Begoña; Pinazo, María-Jesús; Cabezos, Juan; Muñoz, José; Zarzuela, Francesc; Caylà, Joan A
2011-11-25
Increasing international travel and migration is producing changes in trends in infectious diseases, especially in children from many European cities. The objective of this study was to describe the epidemiology and determine the trends of imported malaria in patients under 20 years old in the city of Barcelona, Spain, during an 18-year period. The study included malaria cases that were laboratory confirmed and reported to the malaria register at the Public Health Agency of Barcelona from 1990 to 2008, residing in Barcelona and less than 20 years old. Patients were classified as natives (born in Spain) or immigrants. Differences in the distribution of demographic, clinical characteristics, and incidence per 100,000 person-year evolution were analysed. Natives and immigrants were compared by logistic regression by calculating the odds ratio (OR) with a 95% confidence interval (CI) and Chi-square for a linear trend (p<0.05). Of the total 174 cases, 143 (82.1%) were immigrants, 100 (57.5%) were female, 121 (69.5%) Plasmodium falciparum, and 108 (62.1%) were visiting friends and relatives (VFR) as the reason for travel. Among the immigrants, 99 (67.8%) were from Equatorial Guinea. Immigrant cases more frequently travelled to Africa than natives (p=0.02). The factors associated with imported malaria among immigrant residents was travelling for VFR (OR: 6.2 CI 1.9-20.2) and age 15-19 (OR: 3.7 CI 1-13.3). The incidence increased from 1990 to 1999 (p<0.001) and decreased from 2000 to 2008 (p=0.01), although the global linear trend was not statistically significant (p=0.41). The fatality rate was 0.5%. The majority of cases of malaria in population less than 20 years in Barcelona were immigrants, travelling to Africa for VFR and Plasmodium falciparum was most frequently detected. The trend analysis of the entire study period did not show a statistically significant decline. It is recommended to be aware of malaria, especially among children of immigrants who travel to their parent's home country for VFR. Better access to pre travel advice should be provided.
Reconstruction of March-June precipitation from tree rings in central Liaoning, China
NASA Astrophysics Data System (ADS)
Wang, Yanchao; Liu, Yu
2017-11-01
A dendrochronological profile was generated from Chinese pines ( Pinus tabulaeformis Carr.) in the Qianshan Mountains in northeastern China. Based on correlation analyses, the pattern of precipitation from March to June ( P 36 ) was reconstructed using a simple linear model, which explained 42.7% of the total variance in observed precipitation from 1951 to 2012. The reconstructed P 36 series revealed a consistently increasing trend in precipitation during the twentieth century in the Qianshan Mountains. The reconstructed data showed trends that were similar to those in the variation in trends for March-June precipitation observed at the Shenyang station, the reconstructed January-May precipitation trends in Shenyang City, and the reconstructed average June-September relative humidity for Yiwulü Mountain. The reconstructed data also showed good agreement with the droughts reported in historical documents and recorded by meteorological stations in Liaoning. Spatial correlation analyses show that the reconstructed data reflect the variability in precipitation that occurs over much of northeastern China. In addition, our reconstruction showed a significant periodicity. The significant correlations between the reconstructed P 36 and the El Niño-Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO) and sunspot numbers indicate that precipitation variability in the Qianshan Mountain region is probably driven by extensive atmosphere-sea interactions and solar activities.
Huang, Wan-Yu; Hsin, I-Lun; Chen, Dar-Ren; Chang, Chia-Chu; Kor, Chew-Teng; Chen, Ting-Yu; Wu, Hung-Ming
2017-01-01
Hot flashes have been postulated to be linked to systemic inflammation. This study aimed to investigate the relationship between hot flashes, pro-inflammatory factors, and leukocytes in healthy, non-obese postmenopausal women. In this cross-sectional study, a total of 202 women aged 45-60 years were stratified into one of four groups according to their hot-flash status: never experienced hot flashes (Group N), mild hot flashes (Group m), moderate hot flashes (Group M), and severe hot flashes (Group S). Variables measured in this study included clinical parameters, hot flash experience, leukocytes, and fasting plasma levels of nine circulating cytokines/chemokines measured by using multiplex assays. Multiple linear regression analysis was used to evaluate the associations of hot flashes with these pro-inflammatory factors. The study was performed in a hospital medical center. The mean values of leukocyte number were not different between these four groups. The hot flash status had a positive tendency toward increased levels of circulating IL-6 (P-trend = 0.049), IL-8 (P-trend < 0.001), TNF-α (P-trend = 0.008), and MIP1β (P-trend = 0.04). Multivariate linear regression analysis revealed that hot-flash severity was significantly associated with IL-8 (P-trend < 0.001) and TNFα (P-trend = 0.007) among these nine cytokines/chemokines after adjustment for age, menopausal duration, BMI and FSH. Multivariate analysis further revealed that severe hot flashes were strongly associated with a higher IL-8 (% difference, 37.19%; 95% confidence interval, 14.98,63.69; P < 0.001) and TNFα (51.27%; 6.64,114.57; P < 0.05). The present study provides evidence that hot flashes are associated with circulating IL-8 and TNF-α in healthy postmenopausal women. It suggests that hot flashes might be related to low-grade systemic inflammation.
Huang, Wan-Yu; Hsin, I-Lun; Chen, Dar-Ren; Chang, Chia-Chu; Kor, Chew-Teng; Chen, Ting-Yu
2017-01-01
Introduction Hot flashes have been postulated to be linked to systemic inflammation. This study aimed to investigate the relationship between hot flashes, pro-inflammatory factors, and leukocytes in healthy, non-obese postmenopausal women. Participants and design In this cross-sectional study, a total of 202 women aged 45–60 years were stratified into one of four groups according to their hot-flash status: never experienced hot flashes (Group N), mild hot flashes (Group m), moderate hot flashes (Group M), and severe hot flashes (Group S). Variables measured in this study included clinical parameters, hot flash experience, leukocytes, and fasting plasma levels of nine circulating cytokines/chemokines measured by using multiplex assays. Multiple linear regression analysis was used to evaluate the associations of hot flashes with these pro-inflammatory factors. Settings The study was performed in a hospital medical center. Results The mean values of leukocyte number were not different between these four groups. The hot flash status had a positive tendency toward increased levels of circulating IL-6 (P-trend = 0.049), IL-8 (P-trend < 0.001), TNF-α (P-trend = 0.008), and MIP1β (P-trend = 0.04). Multivariate linear regression analysis revealed that hot-flash severity was significantly associated with IL-8 (P-trend < 0.001) and TNFα (P-trend = 0.007) among these nine cytokines/chemokines after adjustment for age, menopausal duration, BMI and FSH. Multivariate analysis further revealed that severe hot flashes were strongly associated with a higher IL-8 (% difference, 37.19%; 95% confidence interval, 14.98,63.69; P < 0.001) and TNFα (51.27%; 6.64,114.57; P < 0.05). Conclusion The present study provides evidence that hot flashes are associated with circulating IL-8 and TNF-α in healthy postmenopausal women. It suggests that hot flashes might be related to low-grade systemic inflammation. PMID:28846735
Sekula, L K; Lucke, J F; Heist, E K; Czambel, R K; Rubin, R T
1997-03-24
We previously reported a trend toward a higher mean nocturnal serum melatonin (MEL) concentration, based on 30-min blood sampling over 24 h, in 23 female definite endogenous depressive compared to 23 matched normal female control subjects, and no significant difference in 15 male depressives compared to their controls (Rubin et al., 1992). In both groups of patients vs. their controls, there also were trends toward an earlier MEL rise time, by about 30 min, and a later MEL peak time, by about 90 min. Because the offset of MEL secretion was not estimated in that study, the total duration of MEL secretion could not be determined. To further delineate the nocturnal MEL secretion curve, we modeled the MEL data by a linear-Beta model, a four-parameter adaptation of the Beta function. One parameter accounted-for baseline (diurnal) MEL concentration, two accounted for the shapes of the ascending and descending phases of the nocturnal secretion curve, and the fourth accounted for the area under the curve. The model permitted estimation of the start, peak, and end times of nocturnal MEL secretion. There again was a trend toward a higher mean nocturnal MEL concentration in the female depressives compared to their matched controls. There were no significant patient-control differences in secretion onset or peak times in either the women or the men except for nocturnal MEL offset time: the female patients had a trend toward a later offset time, by about 40 min, than their controls; this difference was not present in the men. With women and men analyzed together, the difference in nocturnal MEL offset time between patients and controls just reached significance (P < 0.05). The linear-Beta model appears to satisfactorily fit the MEL data and provides estimators of the onset, peak, and offset times of the activation phase of MEL secretion. This model may be applicable to more severely skewed 24-h hormone secretion curves, such as ACTH and cortisol.
Interannual, solar cycle, and trend terms in middle atmospheric temperature time series from HALOE
NASA Astrophysics Data System (ADS)
Remsberg, E. E.; Deaver, L. E.
2005-03-01
Temperature versus pressure or T(p) time series from the Halogen Occultation Experiment (HALOE) have been generated and analyzed for the period of 1991-2004 and for the mesosphere and upper stratosphere for latitude zones from 40N to 40S. Multiple linear regression (MLR) techniques were used for the analysis of the seasonal and the significant interannual and solar cycle (or decadal-scale) terms. An 11-yr solar cycle (SC) term of amplitude 0.5 to 1.7 K was found for the middle to upper mesosphere; its phase was determined by a Fourier fit to the de-seasonalized residual. This SC term is largest and has a lag of several years for northern hemisphere middle latitudes of the middle mesosphere, perhaps due to the interfering effects of wintertime wave dissipation. The SC response from the MLR models is weaker but essentially in-phase at low latitudes and in the southern hemisphere. An in-phase SC response term is also significant near the tropical stratopause with an amplitude of about 0.4 to 0.6 K, which is somewhat less than predicted from models. Both sub-biennial (688-dy) and QBO (800-dy) terms are resolved for the mid to upper stratosphere along with a decadal-scale term that is presumed to have a 13.5-yr period due to their predicted modulation. This decadal-scale term is out-of-phase with the SC during 1991-2004. However, the true nature and source of this term is still uncertain, especially at 5 hPa. Significant linear cooling trends ranging from -0.3 K to -1.1 K per decade were found in the tropical upper stratosphere and subtropical mesosphere. Trends have not emerged so far for the tropical mesosphere, so it is concluded that the cooling rates that have been resolved for the subtropics are likely upper limits. As HALOE-like measurements continue and their time series lengthen, it is anticipated that better accuracy can be achieved for these interannual, SC, and trend terms.
Liu, Jason J; Crous-Bou, Marta; Giovannucci, Edward; De Vivo, Immaculata
2016-01-01
Background: Coffee is an important source of antioxidants, and consumption of this beverage is associated with many health conditions and a lower mortality risk. However, no study, to our knowledge, has examined whether varying coffee or caffeine consumption levels are associated with telomere length, a biomarker of aging whose shortening can be accelerated by oxidative stress. Objective: We performed a large comprehensive study on how coffee consumption is associated with telomere length. Methods: We used data from the Nurses’ Health Study (NHS), a prospective cohort study of female nurses that began in 1976. We examined the cross-sectional association between coffee consumption and telomere length in 4780 women from the NHS. Coffee consumption information was obtained from validated food-frequency questionnaires, and relative telomere length was measured in peripheral blood leukocytes by the quantitative real-time polymerase chain reaction. Unconditional logistic regression was used to obtain ORs when the telomere length outcome was dichotomized at the median. Linear regression was used for tests of trend with coffee consumption and telomere length as continuous variables. Results: Higher total coffee consumption was significantly associated with longer telomeres after potential confounding adjustment. Compared with non-coffee drinkers, multivariable ORs for those drinking 2 to <3 and ≥3 cups of coffee/d were, respectively, 1.29 (95% CI: 0.99, 1.68) and 1.36 (95% CI: 1.04, 1.78) (P-trend = 0.02). We found a significant linear association between caffeine consumption from all dietary sources and telomere length (P-trend = 0.02) after adjusting for potential confounders, but not after additionally adjusting for total coffee consumption (P-trend = 0.37). Conclusions: We found that higher coffee consumption is associated with longer telomeres among female nurses. Future studies are needed to better understand the influence of coffee consumption on telomeres, which may uncover new knowledge of how coffee consumption affects health and longevity. PMID:27281805
Spatial and temporal variation in the association between temperature and salmonellosis in NZ.
Lal, Aparna; Hales, Simon; Kirk, Martyn; Baker, Michael G; French, Nigel P
2016-04-01
Modelling the relationship between weather, climate and infectious diseases can help identify high-risk periods and provide understanding of the determinants of longer-term trends. We provide a detailed examination of the non-linear and delayed association between temperature and salmonellosis in three New Zealand cities (Auckland, Wellington and Christchurch). Salmonella notifications were geocoded to the city of residence for the reported case. City-specific associations between weekly maximum temperature and the onset date for reported salmonella infections (1997-2007) were modelled using non-linear distributed lag models, while controlling for season and long-term trends. Relatively high temperatures were positively associated with infection risk in Auckland (n=3,073) and Christchurch (n=880), although the former showed evidence of a more immediate relationship with exposure to high temperatures. There was no significant association between temperature and salmonellosis risk in Wellington. Projected increases in temperature with climate change may have localised health impacts, suggesting that preventative measures will need to be region-specific. This evidence contributes to the increasing concern over the public health impacts of climate change. © 2015 Public Health Association of Australia.
Determination of minimum suction level necessary for field dental units.
Charlton, David G
2010-04-01
A significant problem with most field dental units is that their suction is too weak to effectively remove debris from the mouth. The purpose of this study was to determine the minimum clinically acceptable suction level for routine dentistry. A vacuum pump was connected to a high-volume dental evacuation line in a simulated clinical setting and different suction airflow rates were evaluated by nine evaluator dentists for their capability to effectively remove amalgam debris and water. Airflow levels were rated as "clinically acceptable" or "clinically unacceptable" by each evaluator. Data were analyzed using a chi2 test for trend. Analysis indicated a significant linear trend between airflow and ratings (p < 0.0001). The first airflow level considered by all evaluators as producing clinically acceptable suction was 4.5 standard cubic feet per minute (0.127 standard cubic meters per minute). This value should be the minimum level required for all military field dental units.
NASA Astrophysics Data System (ADS)
Jeyakumar, S.
2016-06-01
The dependence of the turnover frequency on the linear size is presented for a sample of Giga-hertz Peaked Spectrum and Compact Steep Spectrum radio sources derived from complete samples. The dependence of the luminosity of the emission at the peak frequency with the linear size and the peak frequency is also presented for the galaxies in the sample. The luminosity of the smaller sources evolve strongly with the linear size. Optical depth effects have been included to the 3D model for the radio source of Kaiser to study the spectral turnover. Using this model, the observed trend can be explained by synchrotron self-absorption. The observed trend in the peak-frequency-linear-size plane is not affected by the luminosity evolution of the sources.
Armstrong, A; Powell, C; Powell, R; Hallam, N; Taylor, J; Bird, J; Sarran, C; Oliver, D
2014-03-01
The last 20 years has seen a marked improvement in skin cancer awareness campaigns. We sought to establish whether this has affected the presenting Breslow thickness of malignant melanoma in the South West. This is a retrospective study looking at the first presentation of melanomas from 2003 to 2011. Data was accessed using the local online melanoma database. A total of 2001 new melanomas presented from 2003 to 2012 (Male:Female = 1:1.062). The average yearly number of melanomas was 200.1 (range = 138-312). The mean age was 62.5 years (range 12-99). Data was analysed using a Chi² test. For 0-1 mm melanomas, there is a significant difference in the observed versus expected values over the 10 years (p = 0.0018). There is an increasing proportion of 0-1 mm (thin) melanomas presenting year on year, with a positive linear trend. This is very statistically significant (p < 0.0001). The 1-2 mm melanomas are decreasing in proportion with a negative linear trend (p = 0.0013). The 2-4 mm are also decreasing in proportion (p = 0.0253). There is no significant change in the thick >4 mm melanomas (p = 0.1456). The proportion of thin 0-1 mm melanomas presenting in South West England has significantly increased from 2003 to 2012. There is no significant change in the thick >4 mm melanomas. This may be a result of increased public awareness due to effective public health campaigns which has significant prognostic and financial implications. Copyright © 2013 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.
Seasonality of climate change and oscillations in the Northeast Asia and Northwest Pacific
NASA Astrophysics Data System (ADS)
Ponomarev, V.; Salomatin, A.; Kaplunenko, D.; Krokhin, V.
2003-04-01
The main goals of this study are to estimate and compare the seasonality of centennial/semi-centennial climatic tendencies and dominated oscillations in surface air temperature and precipitation over continental and marginal areas of the Northeast Asia, as well as in the Northwest Pacific SST. We use monthly mean data for the 20th century from the NOAA Global History Climatic Network, JMA data base and WMU/COADS World Atlas of Surface Marine Data. Details of climate change/oscillations associated with cooling or warming in different areas and periods of a year are revealed. Wavelet analyses and two methods of the linear trend estimation are applied. First one is least-squares (LS) method with Fisher’s test for statistical significance level. Second one is nonparametric robust (NR) method, based on Theil's rank regression and Kendall's test for statistical significance level. The NR method should be applied to time series with abnormal distribution function typical for precipitation time series. Application of the NR method result in increase the statistical significance of both positive and negative linear trends in all cases of abnormal distribution with negative/positive skewness and low/high kurtosis. Using this method, we have determined spatial patterns of statistically significant climatic trends in surface air temperature, precipitation in the Northeast Asia, and in the Northwest Pacific SST. The most substantial centennial warming in the vast continental area of the mid-latitude band is found mainly for December March. The semi-centennial/ centennial cooling occurs in South Siberia and the subarctic mid-continental area in June September. Opposite tendencies were also revealed in precipitation and SST. Positive semi-centennial tendency in the SST in the second half of the 20th century predominates in the Kuroshio region and in the northwestern area of the subarctic gyre in winter. Negative tendency in the SST dominates in the southwestern subarctic gyre and the offshore area of the subtropic gyre in summer. Comparison of air temperature, precipitation, SST trends and oscillations in different seasons over land marginal and continental areas, as well as in the subarctic and subtropic zones indicates general features of the Northeast Asian Monsoon change/oscillation in 20th century and its second half. Similar features of seasonality in centennial, semi-centennial trends and dominated oscillations are manifested. Climate change and oscillation in the Northwest Pacific marginal seas revealed for the 20th century are explained.
Seasonality of climate change and oscillations in the Northeast Asia and Northwest Pacific
NASA Astrophysics Data System (ADS)
Ponomarev, V.; Salomatin, A.; Kaplunenko, D.; Krokhin, V.
2003-04-01
The main goals of this study are to estimate and compare the centennial/semi-centennial climatic tendencies and oscillations in surface air temperature and precipitation over continental and marginal areas of the Northeast Asian, as well as in the Northwest Pacific SST for all months of a year. We use monthly mean data for the 20th century from the NOAA Global History Climatic Network, JMA data base and WMU/COADS World Atlas of Surface Marine Data. Details of climate change/oscillations associated with cooling or warming in different areas and periods of a year are revealed. Wavelet analyses and two methods of the linear trend estimation are applied. First one is least-squares (LS) method with Fisher’s test for statistical significance level. Second one is nonparametric robust (NR) method, based on Theil's rank regression and Kendall's test for statistical significance level. The NR method should be applied to time series with abnormal distribution function typical for precipitation time series. Application of the NR method result in increase the statistical significance of both positive and negative linear trends in all cases of abnormal distribution with negative/positive skewness and low/high kurtosis. Using this method, we have determined spatial patterns of statistically significant climatic trends in surface air temperature, precipitation in the Northeast Asia, and in the Northwest Pacific SST. The most substantial centennial warming in the vast continental area of the mid-latitude band is found mainly for December March. The semi-centennial/ centennial cooling occurs in South Siberia and the subarctic mid-continental area in June September. Opposite tendencies were also revealed in precipitation and SST. Positive semi-centennial tendency in the SST in the second half of the 20th century predominates in the Kuroshio region and in the northwestern area of the subarctic gyre in winter. Negative tendency in the SST dominates in the southwestern subarctic gyre and the offshore area of the subtropic gyre in summer. Comparison of air temperature, precipitation, SST trends and oscillations in different seasons over land marginal and continental areas, as well as in the subarctic and subtropic zones indicates general features of the Northeast Asian Monsoon change/oscillation in 20th century and its second half. Similar features of seasonality in centennial, semi-centennial trends and dominated oscillations are manifested. Climate change and oscillation in the Northwest Pacific marginal seas revealed for the 20th century are explained.
NASA Astrophysics Data System (ADS)
Zerefos, Christos; Kapsomenakis, John; Eleftheratos, Kostas; Tourpali, Kleareti; Petropavlovskikh, Irina; Hubert, Daan; Godin-Beekmann, Sophie; Steinbrecht, Wolfgang; Frith, Stacey; Sofieva, Viktoria; Hassler, Birgit
2018-05-01
This paper is focusing on the representativeness of single lidar stations for zonally averaged ozone profile variations over the middle and upper stratosphere. From the lower to the upper stratosphere, ozone profiles from single or grouped lidar stations correlate well with zonal means calculated from the Solar Backscatter Ultraviolet Radiometer (SBUV) satellite overpasses. The best representativeness with significant correlation coefficients is found within ±15° of latitude circles north or south of any lidar station. This paper also includes a multivariate linear regression (MLR) analysis on the relative importance of proxy time series for explaining variations in the vertical ozone profiles. Studied proxies represent variability due to influences outside of the earth system (solar cycle) and within the earth system, i.e. dynamic processes (the Quasi Biennial Oscillation, QBO; the Arctic Oscillation, AO; the Antarctic Oscillation, AAO; the El Niño Southern Oscillation, ENSO), those due to volcanic aerosol (aerosol optical depth, AOD), tropopause height changes (including global warming) and those influences due to anthropogenic contributions to atmospheric chemistry (equivalent effective stratospheric chlorine, EESC). Ozone trends are estimated, with and without removal of proxies, from the total available 1980 to 2015 SBUV record. Except for the chemistry related proxy (EESC) and its orthogonal function, the removal of the other proxies does not alter the significance of the estimated long-term trends. At heights above 15 hPa an inflection point
between 1997 and 1999 marks the end of significant negative ozone trends, followed by a recent period between 1998 and 2015 with positive ozone trends. At heights between 15 and 40 hPa the pre-1998 negative ozone trends tend to become less significant as we move towards 2015, below which the lower stratosphere ozone decline continues in agreement with findings of recent literature.
Extreme Precipitation in Poland in the Years 1951-2010
NASA Astrophysics Data System (ADS)
Malinowska, Miroslawa
2017-12-01
The characteristics of extreme precipitation, including the dominant trends, were analysed for eight stations located in different parts of Poland for the period 1951-2010. Five indices enabling the assessment of the intensity and frequency of both extremely dry and wet conditions were applied. The indices included the number of days with precipitation ≥10mm·d-1 (R10), maximum number of consecutive dry days (CDD), maximum 5-day precipitation total (R5d), simple daily intensity index (SDII), and the fraction of annual total precipitation due to events exceeding the 95th percentile calculated for the period 1961-1990. Annual trends were calculated using standard linear regression method, while the fit of the model was assessed with the F-test at the 95% confidence level. The analysed changes in extreme precipitation showed mixed patterns. A significant positive trend in the number of days with precipitation ≥10mm·d-1 (R10) was observed in central Poland, while a significant negative one, in south-eastern Poland. Based on the analysis of maximum 5-day precipitation totals (R5d), statistically significant positive trends in north-western, western and eastern parts of the country were detected, while the negative trends were found in the central and northeastern parts. Daily precipitation, expressed as single daily intensity index (SDII), increased over time in northern and central Poland. In southern Poland, the variation of SDII index showed non-significant negative tendencies. Finally, the fraction of annual total precipitation due to the events exceeding the 1961-1990 95th percentile increased at one station only, namely, in Warsaw. The indicator which refers to dry conditions, i.e. maximum number of consecutive dry days (CDD) displayed negative trends throughout the surveyed area, with the exception of Szczecin that is a representative of north-western Poland.
Robitaille, Annie; Garcia, Linda; McIntosh, Cameron
2015-09-01
The current study examines the longitudinal relationship between dementia-related challenging behaviors (e.g., vocal disruption, physical aggression, repetitive behaviors, and restlessness) and cognitive functioning in the long-term care (LTC) context. A multivariate latent growth curve model within the structural equation modeling (SEM) framework was applied to data collected from 16,804 older adults upon admission to LTC and every 3 months for a period of 2.5 years. Increases in challenging behaviors were characterized by a significant positive linear and negative quadratic trend (i.e., a subtle leveling off at later assessment times), whereas increases in cognitive impairment were characterized by a positive linear trend. On average, individuals who were more cognitively impaired upon entry into LTC and who exhibited a steeper increase in cognitive impairment also exhibited more challenging behaviors at entry into LTC and a steeper increase in challenging behaviors, respectively. At the within-person level, individuals demonstrating an increase in cognitive impairment at a specific occasion were also more likely to demonstrate an increase in challenging behaviors at that same occasion; however, the magnitude of these effects was very small, suggesting limited practical implications. This study provides novel empirical evidence about the coevolution of cognitive impairment and challenging behaviors, going beyond prior research that has been either cross-sectional in nature, examined longitudinal change in only 1 variable, or simply looked at linear trends without attempting to explore the possibility of nonlinear change. Most importantly, this longitudinal examination of persons with dementia living in LTC has implications for how challenging behaviors can be better managed and for how new strategies can be implemented to prevent challenging behaviors. (c) 2015 APA, all rights reserved).
NASA Astrophysics Data System (ADS)
Rodil, I. F.; Lastra, M.
2004-09-01
Ten sandy beaches along the north coast of Spain were studied during September 1999 to analyse the number of species, abundance and biomass of macroinfauna along a gradient of intermediate beach types and exposure range. Faunal samples were collected with metallic cylinders (25 cm diameter, 15 cm depth) at 10 equally spaced shore levels along six replicated transects separated randomly and extending from above the drift line to the low tide swash zone. Exposure rate, Dean's parameter ( Ω), beach state index (BSI) and relative tidal range (RTR) were estimated at each beach. Length and width of the beach, intertidal slope, sorting and median grain size and also swash amplitude and wave characteristics were measured. The number of species was between 10 and 29. Macrofaunal abundances ranged between 4962 and 71,228 ind. linear m -1 and between 31 and 329 ind. m -2, while biomass (ash free dry weight) ranged between 0.027 and 0.278 g m -2 and between 3 and 61 g linear m -1. The results show some significant trends: the number of species is the biotic variable most affected by physical and morphodynamic factors, increasing linearly with relative tidal range and decreasing with increasing average grain size. The same trend was observed from exposed to very exposed beaches and the biomass decreased exponentially with increasing average grain size. These trends agree with previous studies in different coasts in the world where coarse sands limit the benthic macrofauna. The morphodynamic parameters as Dean's parameter or Beach State Index did not show a predictive value. The results suggest that different characteristics of benthic macrofauna communities in intermediate beaches can be affected in different ways by the physical processes involved in beach morphodynamics.
Temporal variability and coloured noise of SLR translations with respect to the ITRF2014 origin
NASA Astrophysics Data System (ADS)
Riddell, Anna; King, Matt; Watson, Christopher; Rietbroek, Roelof; Sun, Yu; Riva, Riccardo
2017-04-01
Inferring large-scale environmental change, such as of sea-level change, glacial isostatic adjustment or ice sheet volume change (i.e. from altimetry), requires a geodetic reference frame stable to 0.1 mm/yr. Since 1988, each iterative improvement in the precision of the International Terrestrial Reference Frame (ITRF) has enabled significant advancement of scientific and technical research in the Earth sciences. We demonstrate the occurrence of coloured noise in the translation components between the SLR network and the long-term ITRF2014 origin from 1993.0 to 2015.0 with power law spectral indices close to -1, where white-noise-only linear trend uncertainties are underestimated by a factor of five in contrast to power-law linear trend uncertainties. The observed geocentre motion is expected to be influenced by the SLR observing network, known as the "network effect". Temporal translations in the SLR network may not necessarily average out over long time periods and therefore have the potential to shift the computed reference frame origin from the true long term centre of mass. Comparison with geophysical loading models demonstrates that the variability cannot be fully accounted for by surface mass transport such as changes in atmospheric, hydrologic or glacial loading. Our results demonstrate that the proportion of variance explained by geophysical surface loading is less than 50% in each translational component. Evidence of temporal variability in both the SLR amplitude and trend of the annual signal suggest that a different coloured noise model be considered in place of, or as an extension of, the traditional linear and white-noise-only model to represent the long-term average centre of mass.
Jacobsen, B K; Oda, K; Knutsen, S F; Fraser, G E
2009-01-01
Background Little is known about the relationship between age at menarche and total mortality and mortality from ischaemic heart disease and stroke. Methods A cohort study of 19 462 Californian Seventh-Day Adventist women followed-up from 1976 to 1988. A total of 3313 deaths occurred during follow-up, of which 809 were due to ischaemic heart disease and 378 due to stroke. Results An early menarche was associated with increased total mortality (P-value for linear trend <0.001), ischaemic heart disease (P-value for linear trend = 0.01) and stroke (P-value for linear trend = 0.02) mortality. There were, however, also some indications of an increased ischaemic heart disease mortality in women aged 16–18 at menarche (5% of the women). When assessed as a linear relationship, a 1-year delay in menarche was associated with 4.5% (95% CI 2.3–6.7) lower total mortality. The association was stronger for ischaemic heart disease [6.0% (95% CI 1.2–10.6)] and stroke [8.6% (95% CI 1.6–15.1)] mortality. Conclusions The results suggest that there is a linear, inverse relationship between age at menarche and total mortality as well as with ischaemic heart disease and stroke mortality. PMID:19188208
Jacobsen, B K; Oda, K; Knutsen, S F; Fraser, G E
2009-02-01
Little is known about the relationship between age at menarche and total mortality and mortality from ischaemic heart disease and stroke. A cohort study of 19 462 Californian Seventh-Day Adventist women followed-up from 1976 to 1988. A total of 3313 deaths occurred during follow-up, of which 809 were due to ischaemic heart disease and 378 due to stroke. An early menarche was associated with increased total mortality (P-value for linear trend <0.001), ischaemic heart disease (P-value for linear trend = 0.01) and stroke (P-value for linear trend = 0.02) mortality. There were, however, also some indications of an increased ischaemic heart disease mortality in women aged 16-18 at menarche (5% of the women). When assessed as a linear relationship, a 1-year delay in menarche was associated with 4.5% (95% CI 2.3-6.7) lower total mortality. The association was stronger for ischaemic heart disease [6.0% (95% CI 1.2-10.6)] and stroke [8.6% (95% CI 1.6-15.1)] mortality. The results suggest that there is a linear, inverse relationship between age at menarche and total mortality as well as with ischaemic heart disease and stroke mortality.
Trends in high-risk sexual behaviors among general population groups in China: a systematic review.
Cai, Rui; Richardus, Jan Hendrik; Looman, Caspar W N; de Vlas, Sake J
2013-01-01
The objective of this review was to investigate whether Chinese population groups that do not belong to classical high risk groups show an increasing trend of engaging in high-risk sexual behaviors. We systematically searched the English and Chinese literature on sexual risk behaviors published between January 1980 and March 2012 in PubMed and the China National Knowledge Infrastructure (CNKI). We included observational studies that focused on population groups other than commercial sex workers (CSWs) and their clients, and men who have sex with men (MSM) and quantitatively reported one of the following indicators of recent high-risk sexual behavior: premarital sex, commercial sex, multiple sex partners, condom use or sexually transmitted infections (STIs). We used generalized linear mixed model to examine the time trend in engaging in high-risk sexual behaviors. We included 174 observational studies involving 932,931 participants: 55 studies reported on floating populations, 73 on college students and 46 on other groups (i.e. out-of-school youth, rural residents, and subjects from gynecological or obstetric clinics and premarital check-up centers). From the generalized linear mixed model, no significant trends in engaging in high-risk sexual behaviors were identified in the three population groups. Sexual risk behaviors among certain general population groups have not increased substantially. These groups are therefore unlikely to incite a STI/HIV epidemic among the general Chinese population. Because the studied population groups are not necessarily representative of the general population, the outcomes found may not reflect those of the general population.
Functional Multi-Locus QTL Mapping of Temporal Trends in Scots Pine Wood Traits
Li, Zitong; Hallingbäck, Henrik R.; Abrahamsson, Sara; Fries, Anders; Gull, Bengt Andersson; Sillanpää, Mikko J.; García-Gil, M. Rosario
2014-01-01
Quantitative trait loci (QTL) mapping of wood properties in conifer species has focused on single time point measurements or on trait means based on heterogeneous wood samples (e.g., increment cores), thus ignoring systematic within-tree trends. In this study, functional QTL mapping was performed for a set of important wood properties in increment cores from a 17-yr-old Scots pine (Pinus sylvestris L.) full-sib family with the aim of detecting wood trait QTL for general intercepts (means) and for linear slopes by increasing cambial age. Two multi-locus functional QTL analysis approaches were proposed and their performances were compared on trait datasets comprising 2 to 9 time points, 91 to 455 individual tree measurements and genotype datasets of amplified length polymorphisms (AFLP), and single nucleotide polymorphism (SNP) markers. The first method was a multilevel LASSO analysis whereby trend parameter estimation and QTL mapping were conducted consecutively; the second method was our Bayesian linear mixed model whereby trends and underlying genetic effects were estimated simultaneously. We also compared several different hypothesis testing methods under either the LASSO or the Bayesian framework to perform QTL inference. In total, five and four significant QTL were observed for the intercepts and slopes, respectively, across wood traits such as earlywood percentage, wood density, radial fiberwidth, and spiral grain angle. Four of these QTL were represented by candidate gene SNPs, thus providing promising targets for future research in QTL mapping and molecular function. Bayesian and LASSO methods both detected similar sets of QTL given datasets that comprised large numbers of individuals. PMID:25305041
Functional multi-locus QTL mapping of temporal trends in Scots pine wood traits.
Li, Zitong; Hallingbäck, Henrik R; Abrahamsson, Sara; Fries, Anders; Gull, Bengt Andersson; Sillanpää, Mikko J; García-Gil, M Rosario
2014-10-09
Quantitative trait loci (QTL) mapping of wood properties in conifer species has focused on single time point measurements or on trait means based on heterogeneous wood samples (e.g., increment cores), thus ignoring systematic within-tree trends. In this study, functional QTL mapping was performed for a set of important wood properties in increment cores from a 17-yr-old Scots pine (Pinus sylvestris L.) full-sib family with the aim of detecting wood trait QTL for general intercepts (means) and for linear slopes by increasing cambial age. Two multi-locus functional QTL analysis approaches were proposed and their performances were compared on trait datasets comprising 2 to 9 time points, 91 to 455 individual tree measurements and genotype datasets of amplified length polymorphisms (AFLP), and single nucleotide polymorphism (SNP) markers. The first method was a multilevel LASSO analysis whereby trend parameter estimation and QTL mapping were conducted consecutively; the second method was our Bayesian linear mixed model whereby trends and underlying genetic effects were estimated simultaneously. We also compared several different hypothesis testing methods under either the LASSO or the Bayesian framework to perform QTL inference. In total, five and four significant QTL were observed for the intercepts and slopes, respectively, across wood traits such as earlywood percentage, wood density, radial fiberwidth, and spiral grain angle. Four of these QTL were represented by candidate gene SNPs, thus providing promising targets for future research in QTL mapping and molecular function. Bayesian and LASSO methods both detected similar sets of QTL given datasets that comprised large numbers of individuals. Copyright © 2014 Li et al.
Trends in High-Risk Sexual Behaviors among General Population Groups in China: A Systematic Review
Cai, Rui; Richardus, Jan Hendrik; Looman, Caspar W. N.; de Vlas, Sake J.
2013-01-01
Background The objective of this review was to investigate whether Chinese population groups that do not belong to classical high risk groups show an increasing trend of engaging in high-risk sexual behaviors. Methods We systematically searched the English and Chinese literature on sexual risk behaviors published between January 1980 and March 2012 in PubMed and the China National Knowledge Infrastructure (CNKI). We included observational studies that focused on population groups other than commercial sex workers (CSWs) and their clients, and men who have sex with men (MSM) and quantitatively reported one of the following indicators of recent high-risk sexual behavior: premarital sex, commercial sex, multiple sex partners, condom use or sexually transmitted infections (STIs). We used generalized linear mixed model to examine the time trend in engaging in high-risk sexual behaviors. Results We included 174 observational studies involving 932,931 participants: 55 studies reported on floating populations, 73 on college students and 46 on other groups (i.e. out-of-school youth, rural residents, and subjects from gynecological or obstetric clinics and premarital check-up centers). From the generalized linear mixed model, no significant trends in engaging in high-risk sexual behaviors were identified in the three population groups. Discussion Sexual risk behaviors among certain general population groups have not increased substantially. These groups are therefore unlikely to incite a STI/HIV epidemic among the general Chinese population. Because the studied population groups are not necessarily representative of the general population, the outcomes found may not reflect those of the general population. PMID:24236121
Reconciling differences in stratospheric ozone composites
NASA Astrophysics Data System (ADS)
Ball, William T.; Alsing, Justin; Mortlock, Daniel J.; Rozanov, Eugene V.; Tummon, Fiona; Haigh, Joanna D.
2017-10-01
Observations of stratospheric ozone from multiple instruments now span three decades; combining these into composite datasets allows long-term ozone trends to be estimated. Recently, several ozone composites have been published, but trends disagree by latitude and altitude, even between composites built upon the same instrument data. We confirm that the main causes of differences in decadal trend estimates lie in (i) steps in the composite time series when the instrument source data changes and (ii) artificial sub-decadal trends in the underlying instrument data. These artefacts introduce features that can alias with regressors in multiple linear regression (MLR) analysis; both can lead to inaccurate trend estimates. Here, we aim to remove these artefacts using Bayesian methods to infer the underlying ozone time series from a set of composites by building a joint-likelihood function using a Gaussian-mixture density to model outliers introduced by data artefacts, together with a data-driven prior on ozone variability that incorporates knowledge of problems during instrument operation. We apply this Bayesian self-calibration approach to stratospheric ozone in 10° bands from 60° S to 60° N and from 46 to 1 hPa (˜ 21-48 km) for 1985-2012. There are two main outcomes: (i) we independently identify and confirm many of the data problems previously identified, but which remain unaccounted for in existing composites; (ii) we construct an ozone composite, with uncertainties, that is free from most of these problems - we call this the BAyeSian Integrated and Consolidated (BASIC) composite. To analyse the new BASIC composite, we use dynamical linear modelling (DLM), which provides a more robust estimate of long-term changes through Bayesian inference than MLR. BASIC and DLM, together, provide a step forward in improving estimates of decadal trends. Our results indicate a significant recovery of ozone since 1998 in the upper stratosphere, of both northern and southern midlatitudes, in all four composites analysed, and particularly in the BASIC composite. The BASIC results also show no hemispheric difference in the recovery at midlatitudes, in contrast to an apparent feature that is present, but not consistent, in the four composites. Our overall conclusion is that it is possible to effectively combine different ozone composites and account for artefacts and drifts, and that this leads to a clear and significant result that upper stratospheric ozone levels have increased since 1998, following an earlier decline.
Gu, Xiao-Jun; Emerson, David R
2014-06-01
Understanding the thermal behavior of a rarefied gas remains a fundamental problem. In the present study, we investigate the predictive capabilities of the regularized 13 and 26 moment equations. In this paper, we consider low-speed problems with small gradients, and to simplify the analysis, a linearized set of moment equations is derived to explore a classic temperature problem. Analytical solutions obtained for the linearized 26 moment equations are compared with available kinetic models and can reliably capture all qualitative trends for the temperature-jump coefficient and the associated temperature defect in the thermal Knudsen layer. In contrast, the linearized 13 moment equations lack the necessary physics to capture these effects and consistently underpredict kinetic theory. The deviation from kinetic theory for the 13 moment equations increases significantly for specular reflection of gas molecules, whereas the 26 moment equations compare well with results from kinetic theory. To improve engineering analyses, expressions for the effective thermal conductivity and Prandtl number in the Knudsen layer are derived with the linearized 26 moment equations.
Quantification of toy sword kinematics with male pediatric volunteers.
Beeman, Stephanie M; Rowson, Steven; Duma, Stefan M
2014-01-01
While extensive research in toy safety has been performed, data is unavailable with regard to the kinematics of toy swords. To improve upon design criteria, knowledge of a childs physical capacity is essential. The purpose of this study was to quantify the linear and angular velocities generated by children swinging toy swords. A total of 36 male subjects, ages 4-14 years old, each participated in one trial. Subjects were instructed to swing a toy sword as fast and hard as possible for ~10 seconds. A Vicon motion analysis system was used to capture subject and sword kinematics. Peak linear and angular sword velocities were calculated. A strong correlation was identified between age and velocity. The 8-14 year old males were not significantly different. The 4 year old males generated significantly lower velocities than the 8-14 year old males. The 6 year old males produced significantly lower velocities than the 10- 14 year old males. It was concluded that age had a significant effect on the linear and angular velocities generated by children. The trends observed within this study likely result from typical pediatric and adolescent development. By accounting for the physical capabilities of a specific population, toys can be designed with decreased inherent risks of injury.
NDVI-Based analysis on the influence of human activities on vegetation variation on Hainan Island
NASA Astrophysics Data System (ADS)
Luo, Hongxia; Dai, Shengpei; Xie, Zhenghui; Fang, Jihua
2018-02-01
Using the Moderate Resolution Imaging Spectroradiometer-normalized difference vegetation index (NDVI) dataset, we analyzed the predicted NDVI values variation and the influence of human activities on vegetation on Hainan Island during 2001-2015. We investigated the roles of human activities in vegetation variation, particularly from 2002 when implemented the Grain-for-Greenprogram on Hainan Island. The trend analysis, linear regression model and residual analysis were used to analyze the data. The results of the study showed that (1) The predicted vegetation on Hainan Island showed an general upward trend with a linear growth rate of 0.0025/10y (p<0.05) over the past 15 years. The areas where vegetation increasedaccounted for 52.28%, while the areas where vegetation decreased accounted for 47.72%. (2) The residual NDVI values across the region significantly increased, with a growth rate of 0.023/10y.The vegetation increased across 35.95% of Hainan Island, while it decreased in 20.2% of the area as a result of human activities. (3) In general, human activities had played a positive role in the vegetation increase on Hainan Island, and the residual NDVI trend of this region showed positive outcomes for vegetation variation after implementing ecological engineering projects. However, it indicated a growing risk of vegetation degradation in the coastal region of Hainan Island as a result of rapid urbanization, land reclamation.
Matsuba, Ikuro; Saito, Kazumi; Takai, Masahiko; Hirao, Koichi; Sone, Hirohito
2012-09-01
To investigate the relationship between fasting insulin levels and metabolic risk factors (MRFs) in type 2 diabetic patients at the first clinic/hospital visit in Japan over the years 2000 to 2009. In total, 4,798 drug-naive Japanese patients with type 2 diabetes were registered on their first clinic/hospital visits. Conventional clinical factors and fasting insulin levels were observed at baseline within the Japan Diabetes Clinical Data Management (JDDM) study between consecutive 2-year groups. Multiple linear regression analysis was performed using a model in which the dependent variable was fasting insulin values using various clinical explanatory variables. Fasting insulin levels were found to be decreasing from 2000 to 2009. Multiple linear regression analysis with the fasting insulin levels as the dependent variable showed that waist circumference (WC), BMI, mean blood pressure, triglycerides, and HDL cholesterol were significant, with WC and BMI as the main factors. ANCOVA after adjustment for age and fasting plasma glucose clearly shows the decreasing trend in fasting insulin levels and the increasing trend in BMI. During the 10-year observation period, the decreasing trend in fasting insulin was related to the slight increase in WC/BMI in type 2 diabetes. Low pancreatic β-cell reserve on top of a lifestyle background might be dependent on an increase in MRFs.
Matsuba, Ikuro; Saito, Kazumi; Takai, Masahiko; Hirao, Koichi; Sone, Hirohito
2012-01-01
OBJECTIVE To investigate the relationship between fasting insulin levels and metabolic risk factors (MRFs) in type 2 diabetic patients at the first clinic/hospital visit in Japan over the years 2000 to 2009. RESEARCH DESIGN AND METHODS In total, 4,798 drug-naive Japanese patients with type 2 diabetes were registered on their first clinic/hospital visits. Conventional clinical factors and fasting insulin levels were observed at baseline within the Japan Diabetes Clinical Data Management (JDDM) study between consecutive 2-year groups. Multiple linear regression analysis was performed using a model in which the dependent variable was fasting insulin values using various clinical explanatory variables. RESULTS Fasting insulin levels were found to be decreasing from 2000 to 2009. Multiple linear regression analysis with the fasting insulin levels as the dependent variable showed that waist circumference (WC), BMI, mean blood pressure, triglycerides, and HDL cholesterol were significant, with WC and BMI as the main factors. ANCOVA after adjustment for age and fasting plasma glucose clearly shows the decreasing trend in fasting insulin levels and the increasing trend in BMI. CONCLUSIONS During the 10-year observation period, the decreasing trend in fasting insulin was related to the slight increase in WC/BMI in type 2 diabetes. Low pancreatic β-cell reserve on top of a lifestyle background might be dependent on an increase in MRFs. PMID:22665215
Associations between Dietary Intake of Choline and Betaine and Lung Cancer Risk
Ying, Jun; Rahbar, Mohammad H.; Hallman, D. Michael; Hernandez, Ladia M.; Spitz, Margret R.; Forman, Michele R.; Gorlova, Olga Y.
2013-01-01
Evidence from human and animal research indicates that choline metabolic pathways may be activated during a variety of diseases, including cancer. We report results of a case-control study of 2821 lung cancer cases and 2923 controls that assessed associations of choline and betaine dietary intakes with lung cancer. Using multivariable logistic regression analyses, we report a significant association between higher betaine intake and lower lung cancer risk that varied by smoking status. Specifically, no significant association was observed between betaine intake and lung cancer among never-smokers. However, higher betaine intake was significantly associated with reduced lung cancer risk among smokers, and the protective effect was more evident among current than former smokers: for former and current smokers, the ORs (95% CI) of lung cancer for individuals with highest as compared to lowest quartiles of intake were 0.70(0.55–0.88) and 0.51(0.39–0.66) respectively. Significant linear trend of higher betaine intake and lower lung cancer risk was observed among both former (ptrend = 0.002) and current (ptrend<0.0001) smokers. A similar protective effect was also observed with choline intake both in overall analysis as well as among current smokers, with p-values for chi-square tests being 0.001 and 0.004 respectively, but the effect was less evident, as no linear trend was observed. Our results suggest that choline and betaine intake, especially higher betaine intake, may be protective against lung cancer through mitigating the adverse effect of smoking. PMID:23383301
Simulation of Rainfall Variability Over West Africa
NASA Astrophysics Data System (ADS)
Bader, J.; Latif, M.
The impact of sea surface temperature (SST) and vegetation on precipitation over West Africa is investigated with the atmospheric general circulation model ECHAM4.x/T42. Ensemble experiments -driven with observed SST- show that At- lantic SST has a significant influence on JJA precipitation over West Africa. Four- teen experiments were performed in which the climatological SST was enhanced or decreased by one Kelvin in certain ocean areas. Changing SST in the eastern tropi- cal Atlantic only caused significant changes along the Guinea Coast, with a positive SSTA increasing rainfall and a negative reducing it. The response was nearly linear. Changing SST in other ocean areas caused significant changes over West Africa, es- pecially in the Sahel area. The response is found to be non linear, with only negative SSTA leading to significant reduction in Sahel rainfall. Also, the impact of the SSTAs from the different ocean regions was not additive with respect to the rainfall. Four simulations with a coupled model (the simple dynamic vegetation model (SVege) and the ECHAM4-AGCM were coupled) were also performed, driven with observed SST from 1945 to 1998. The standard ECHAM-AGCM -forced by the same observed SST- was able to reproduce the drying trend from the fifties to the mid-eighties in the Sahel, but failed to mirror the magnitude of the rainfall anomalies. The coupled model was not only able to reproduce this drying trend, but was also able to better reproduce the amplitudes of the rainfall anomalies. The dynamic vegetation acted like an amplifier, increasing the SST induced rainfall anomalies.
NASA Astrophysics Data System (ADS)
Tamminen, J.; Sofieva, V.; Kyrölä, E.; Laine, M.; Degenstein, D. A.; Bourassa, A. E.; Roth, C.; Zawada, D.; Weber, M.; Rozanov, A.; Rahpoe, N.; Stiller, G. P.; Laeng, A.; von Clarmann, T.; Walker, K. A.; Sheese, P.; Hubert, D.; Van Roozendael, M.; Zehner, C.; Damadeo, R. P.; Zawodny, J. M.; Kramarova, N. A.; Bhartia, P. K.
2017-12-01
We present a merged dataset of ozone profiles from several satellite instruments: SAGE II on ERBS, GOMOS, SCIAMACHY and MIPAS on Envisat, OSIRIS on Odin, ACE-FTS on SCISAT, and OMPS on Suomi-NPP. The merged dataset is created in the framework of European Space Agency Climate Change Initiative (Ozone_cci) with the aim of analyzing stratospheric ozone trends. For the merged dataset, we used the latest versions of the original ozone datasets. The datasets from the individual instruments have been extensively validated and inter-compared; only those datasets, which are in good agreement and do not exhibit significant drifts with respect to collocated ground-based observations and with respect to each other, are used for merging. The long-term SAGE-CCI-OMPS dataset is created by computation and merging of deseasonalized anomalies from individual instruments. The merged SAGE-CCI-OMPS dataset consists of deseasonalized anomalies of ozone in 10° latitude bands from 90°S to 90°N and from 10 to 50 km in steps of 1 km covering the period from October 1984 to July 2016. This newly created dataset is used for evaluating ozone trends in the stratosphere through multiple linear regression. Negative ozone trends in the upper stratosphere are observed before 1997 and positive trends are found after 1997. The upper stratospheric trends are statistically significant at mid-latitudes in the upper stratosphere and indicate ozone recovery, as expected from the decrease of stratospheric halogens that started in the middle of the 1990s.
Temporal trends in self harm and aggression on a paediatric mental health ward.
Berntsen, Ellen; Starling, Jean; Durheim, Earle; Hainsworth, Cassandra; de Kloet, Liselotte; Chapman, Lucy; Hancock, Karen
2011-02-01
The aim of this paper is to describe trends in aggression and self harm on a mental health inpatient unit for children and adolescents between January 2006 and August 2009. Various ward interventions and the ward milieu were evaluated as possible explanatory factors for trends. This was a retrospective study whereby incidents of aggression, self harm and seclusion were obtained from a computerized Incident Information Management System (IIMS) database. Trends in incidents were analysed using linear regression analyses. Over a 44-month period, 292 incidents of aggression and 139 incidents of self harm were reported. The use of seclusion and the number of aggressive incidents both significantly decreased over time. Trends suggested a positive relationship between the introduction of restraint training, changes in leadership and full staff complement, and a reduction in aggression and seclusion. Although the findings are limited by their retrospective nature and reliance on formal records, this study suggests that different factors can contribute to decrease the incidence of adverse events on a psychiatric ward. Future prospective research is needed to assess the effectiveness of different interventions in both the prevention and management of self harm, aggression and seclusion in child and adolescent inpatient units.
Lin, Chienhung; Chao, Hailun
2012-09-25
The Taiwan government adopted National Health Insurance (NHI) in 1995, providing universal health care to all citizens. It was financed by mandatory premium contributions made by employers, employees, and the government. Since then, the government has faced increasing challenges to control NHI expenditures. The aim of this study was to determine trends in the provision of dental services in Taiwan after the implementation of global budgeting in 1998 and to identify areas of possible concern. This longitudinal before/after study was based on data from the National Health Insurance Research Database from 1996 to 2001. These data were subjected to logistic regression analysis. Linear regression analysis was used to examine changes in delivery of specific services after global budgeting implementation. Utilization of hospital and clinic services was compared. Reimbursement for dental services increased significantly while the number of visits per patient remained steady in both hospitals and clinics. In hospitals, visits for root canal procedures, ionomer restoration, tooth extraction and tooth scaling increased significantly. In dental clinics, visits for amalgam restoration decreased significantly while those for ionomer restoration, tooth extraction, and tooth scaling increased significantly. After the adoption of global budgeting, expenditures for dental services increased dramatically while the number of visits per patient did not, indicating a possible shift in patients to hospital facilities that received additional National Health Insurance funding. The identified trends indicate increased utilization of dental services and uneven distribution of care and dentists. These trends may be compromising the quality of dental care delivered in Taiwan.
Speaks, Crystal; McGlynn, Katherine A; Cook, Michael B
2012-10-01
The current working model of type II testicular germ cell tumor (TGCT) pathogenesis states that carcinoma in situ arises during embryogenesis, is a necessary precursor, and always progresses to cancer. An implicit condition of this model is that only in utero exposures affect the development of TGCT in later life. In an age-period-cohort analysis, this working model contends an absence of calendar period deviations. We tested this contention using data from the SEER registries of the United States. We assessed age-period-cohort models of TGCTs, seminomas, and nonseminomas for the period 1973-2008. Analyses were restricted to whites diagnosed at ages 15-74 years. We tested whether calendar period deviations were significant in TGCT incidence trends adjusted for age deviations and cohort effects. This analysis included 32,250 TGCTs (18,475 seminomas and 13,775 nonseminomas). Seminoma incidence trends have increased with an average annual percentage change in log-linear rates (net drift) of 1.25 %, relative to just 0.14 % for nonseminoma. In more recent time periods, TGCT incidence trends have plateaued and then undergone a slight decrease. Calendar period deviations were highly statistically significant in models of TGCT (p = 1.24(-9)) and seminoma (p = 3.99(-14)), after adjustment for age deviations and cohort effects; results for nonseminoma (p = 0.02) indicated that the effects of calendar period were much more muted. Calendar period deviations play a significant role in incidence trends of TGCT, which indicates that postnatal exposures are etiologically relevant.
Secular trends in storm-level geomagnetic activity
Love, J.J.
2011-01-01
Analysis is made of K-index data from groups of ground-based geomagnetic observatories in Germany, Britain, and Australia, 1868.0-2009.0, solar cycles 11-23. Methods include nonparametric measures of trends and statistical significance used by the hydrological and climatological research communities. Among the three observatory groups, German K data systematically record the highest disturbance levels, followed by the British and, then, the Australian data. Signals consistently seen in K data from all three observatory groups can be reasonably interpreted as physically meaninginful: (1) geomagnetic activity has generally increased over the past 141 years. However, the detailed secular evolution of geomagnetic activity is not well characterized by either a linear trend nor, even, a monotonic trend. Therefore, simple, phenomenological extrapolations of past trends in solar and geomagnetic activity levels are unlikely to be useful for making quantitative predictions of future trends lasting longer than a solar cycle or so. (2) The well-known tendency for magnetic storms to occur during the declining phase of a sunspot-solar cycles is clearly seen for cycles 14-23; it is not, however, clearly seen for cycles 11-13. Therefore, in addition to an increase in geomagnetic activity, the nature of solar-terrestrial interaction has also apparently changed over the past 141 years. ?? Author(s) 2011.
Global long-term ozone trends derived from different observed and modelled data sets
NASA Astrophysics Data System (ADS)
Coldewey-Egbers, M.; Loyola, D.; Zimmer, W.; van Roozendael, M.; Lerot, C.; Dameris, M.; Garny, H.; Braesicke, P.; Koukouli, M.; Balis, D.
2012-04-01
The long-term behaviour of stratospheric ozone amounts during the past three decades is investigated on a global scale using different observed and modelled data sets. Three European satellite sensors GOME/ERS-2, SCIAMACHY/ENVISAT, and GOME-2/METOP are combined and a merged global monthly mean total ozone product has been prepared using an inter-satellite calibration approach. The data set covers the 16-years period from June 1995 to June 2011 and it exhibits an excellent long-term stability, which is required for such trend studies. A multiple linear least-squares regression algorithm using different explanatory variables is applied to the time series and statistically significant positive trends are detected in the northern mid latitudes and subtropics. Global trends are also estimated using a second satellite-based Merged Ozone Data set (MOD) provided by NASA. For few selected geographical regions ozone trends are additionally calculated using well-maintained measurements of individual Dobson/Brewer ground-based instruments. A reasonable agreement in the spatial patterns of the trends is found amongst the European satellite, the NASA satellite, and the ground-based observations. Furthermore, two long-term simulations obtained with the Chemistry-Climate Models E39C-A provided by German Aerospace Center and UMUKCA-UCAM provided by University of Cambridge are analysed.
Evidence for slowdown in stratospheric ozone loss: First stage of ozone recovery
NASA Technical Reports Server (NTRS)
Newchurch, M. J.; Yang, Eun-Su; Cunnold, D. M.; Reinsel, C.; Zawodny, J. M.; Russell, James M., III
2003-01-01
Global ozone trends derived from the Stratospheric Aerosol and Gas Experiment I and II (SAGE I/II) combined with the more recent Halogen Occultation Experiment (HALOE) observations provide evidence of a slowdown in stratospheric ozone losses since 1997. This evidence is quantified by the cumulative sum of residual differences from the predicted linear trend. The cumulative residuals indicate that the rate of ozone loss at 35- 45 km altitudes globally has diminished. These changes in loss rates are consistent with the slowdown of total stratospheric chlorine increases characterized by HALOE HCI measurements. These changes in the ozone loss rates in the upper stratosphere are significant and constitute the first stage of a recovery of the ozone layer.
[Variation trends of the vegetations in distribution region of Amur tiger based on MODIS NDVI].
Wang, Hua-Ru; Wang, Tian-Ming; Ge, Han-Ping
2012-10-01
By using the averaged 250 m MODIS NDVI data in growth seasons of 2000-2010 and the approach of ordinary linear regression, this paper analyzed the variation trends of the vegetations in the distribution region of Amur tiger (Panthera tigris altaica), the Far East region of Russia and the eastern part of Northeast China, as well as the relationships between these variation trends and the anthropogenic activities. In 2000 - 2010, the areas with significantly decreased NDVI were sparsely distributed and accounted for 9.6% of the total, while the areas with significantly increased NDVI were mainly concentrated in the central part of northern Russia Far East Region and only accounted for 0.5% of the total. The percentage of the areas with significantly decreased NDVI in the distribution region of Amur tiger was slightly higher than that in the whole study region. The areas with significantly decreased NDVI were mainly distributed in the places of low elevation, gentle slope, and close to roads/railroads. The number of the pixels with significantly decreased NDVI increased with the increase of the nearest distance to residential locations first, and then decreased gradually. The significant decrease of the NDVI was closely related to the anthropogenic activities, and thus, to adopt effective measures to reduce human disturbances could control the vegetation degradation, and further, provide sustainable basis for the protection of Amur tiger and the conservation of the biodiversity in the studied region.
Fifteen-year trends in the prevalence of barriers to healthy eating in a high-income country.
de Mestral, Carlos; Khalatbari-Soltani, Saman; Stringhini, Silvia; Marques-Vidal, Pedro
2017-03-01
Background: Despite increasing levels of education and income in the Swiss population over time and greater food diversity due to globalization, adherence to dietary guidelines has remained persistently low. This may be because of barriers to healthy eating hampering adherence, but whether these barriers have evolved in prevalence over time has never been assessed, to our knowledge. Objective: We assessed 15-y trends in the prevalence of self-reported barriers to healthy eating in Switzerland overall and according to sex, age, education, and income. Design: We used data from 4 national Swiss Health Surveys conducted between 1997 and 2012 (52,238 participants aged ≥18 y, 55% women), applying multivariable-adjusted logistic regression models to assess trends in prevalence of 6 barriers to healthy eating (taste, price, daily habits, time, lack of willpower, and limited options). Results: The prevalence of 3 barriers exhibited an increasing trend until 2007, followed by a decrease in 2012 (from 44% in 1997 to 50% in 2007 and then to 44% in 2012 for taste, from 40% to 52% and then to 39% for price, and from 29% to 34% and then to 32% for time; quadratic P -trend < 0.0001). Limited options decreased slightly until 2007 (35-33%) and then sharply by 2012 (18%) (linear P -trend < 0.0001). Daily habits remained relatively stable across time from 42% in 1997 to 38% in 2012 (linear P -trend < 0.0001). Conversely, lack of willpower decreased steadily over time from 26% in 1997 to 21% in 2012 (linear P -trend < 0.0001). Trends were similar for all barriers irrespective of sex, age, education, and income. Conclusion: Between 1997 and 2012, barriers to healthy eating remained highly prevalent (≥20%) in the Swiss population and evolved similarly irrespective of age, sex, education, and income. © 2017 American Society for Nutrition.
Is there a signal of sea-level rise in Chesapeake Bay salinity?
NASA Astrophysics Data System (ADS)
Hilton, T. W.; Najjar, R. G.; Zhong, L.; Li, M.
2008-09-01
We evaluate the hypothesis that sea-level rise over the second half of the 20th century has led to detectable increases in Chesapeake Bay salinity. We exploit a simple, statistical model that predicts monthly mean salinity as a function of Susquehanna River flow in 23 segments of the main stem Chesapeake Bay. The residual (observed minus modeled) salinity exhibits statistically significant linear (p < 0.05) trends between 1949 and 2006 in 13 of the 23 segments of the bay. The salinity change estimated from the trend line over this period varies from -2.0 to 2.2, with 10 of the 13 cells showing positive changes. The mean and median salinity changes over all 23 cells are 0.47 and 0.72; over the 13 cells with significant trends they are 0.71 and 1.1. We ran a hydrodynamic model of the bay under present-day and reduced sea level conditions and found a bay-average salinity increase of about 0.5, which supports the hypothesis that the salinity residual trends have a significant component due to sea-level rise. Uncertainties remain, however, due to the spatial and temporal extent of historical salinity data and the infilling of the bay due to sedimentation. The salinity residuals also exhibit interannual variability, with peaks occurring at intervals of roughly 7 to 9 years, which are partially explained by Atlantic Shelf salinity, Potomac River flow and the meridional component of wind stress.
Trends in Daily Cannabis Use Among Cigarette Smokers: United States, 2002-2014.
Goodwin, Renee D; Pacek, Lauren R; Copeland, Jan; Moeller, Scott J; Dierker, Lisa; Weinberger, Andrea; Gbedemah, Misato; Zvolensky, Michael J; Wall, Melanie M; Hasin, Deborah S
2018-01-01
To estimate changes in the prevalence of daily cannabis use among current, former, and never cigarette smokers from 2002 to 2014 in the United States. The National Survey on Drug Use and Health is a nationally representative cross-sectional study conducted annually among persons aged 12 years and older in the United States. Daily cannabis use occurs nearly exclusively among nondaily and daily cigarette smokers compared with former and never smokers (8.03%, 9.01%, 2.79%, 1.05%, respectively). Daily cannabis use increased over the past decade among both nondaily (8.03% [2014] vs 2.85% [2002]; linear trend P < .001) and daily smokers (9.01% [2014]; 4.92% [2002]; linear trend P < .001). Daily cannabis use increased most rapidly among former cigarette smokers (2.79% [2014] vs 0.98% [2002]; linear trend P < .001). Daily cannabis use occurs predominantly among cigarette smokers in the United States. Daily cannabis use increased among current, former, and never smokers over the past decade, with particularly rapid increases among youth and female cigarette smokers. Future research is needed to monitor the observed increase in daily cannabis use, especially among youths and adults who smoke cigarettes.
Fink, Ericka L.; Prince, David K.; Kaltman, Jonathan R.; Atkins, Dianne L.; Austin, Michael; Warden, Craig; Hutchison, Jamie; Daya, Mohamud; Goldberg, Scott; Herren, Heather; Tijssen, Janice A.; Christenson, James; Vaillancourt, Christian; Miller, Ronna; Schmicker, Robert H.; Callaway, Clifton W.
2016-01-01
Aim Outcomes for pediatric out-of-hospital cardiac arrest (OHCA) are poor. Our objective was to determine temporal trends in incidence and mortality for pediatric OHCA. Methods Adjusted incidence and hospital mortality rates of pediatric non-traumatic OHCA patients from 2007-2012 were analyzed using the 9 region Resuscitation Outcomes Consortium - Epidemiological Registry (ROC-Epistry) database. Children were divided into 4 age groups: perinatal (< 3 days), infants (3 days - 1 year), children (1 - 11 years), and adolescents (12 - 19 years). ROC regions were analyzed post-hoc. Results We studied 1,738 children with OHCA. The age- and sex-adjusted incidence rate of OHCA was 8.3 per 100,000 person-years (75.3 for infants vs. 3.7 for children and 6.3 for adolescents, per 100,000 person-years, p<0.001). Incidence rates differed by year (p<0.001) without overall linear trend. Annual survival rates ranged from 6.7-10.2%. Survival was highest in the perinatal (25%) and adolescent (17.3%) groups. Stratified by age group, survival rates over time were unchanged (all p>0.05) but there was a non-significant linear trend (1.3% increase) in infants. In the multivariable logistic regression analysis, infants, unwitnessed event, initial rhythm of asystole, and region were associated with worse survival, all p<0.001. Survival by region ranged from 2.6-14.7%. Regions with the highest survival had more cases of EMS-witnessed OHCA, bystander CPR, and increased EMS-defibrillation (all p<0.05). Conclusions Overall incidence and survival of children with OHCA in ROC regions did not significantly change over a recent 5 year period. Regional variation represents an opportunity for further study to improve outcomes. PMID:27565862
Zhao, Juanjuan; Chen, Shengbin; Jiang, Bo; Ren, Yin; Wang, Hua; Vause, Jonathan; Yu, Haidong
2013-01-01
Irrespective of which side is taken in the densification-sprawl debate, insights into the relationship between urban green space coverage and urbanization have been recognized as essential for guiding sustainable urban development. However, knowledge of the relationships between socio-economic variables of urbanization and long-term green space change is still limited. In this paper, using simple regression, hierarchical partitioning and multi-regression, the temporal trend in green space coverage and its relationship with urbanization were investigated using data from 286 cities between 1989 and 2009, covering all provinces in mainland China with the exception of Tibet. We found that: [1] average green space coverage of cities investigated increased steadily from 17.0% in 1989 to 37.3% in 2009; [2] cities with higher recent green space coverage also had relatively higher green space coverage historically; [3] cities in the same region exhibited similar long-term trends in green space coverage; [4] eight of the nine variables characterizing urbanization showed a significant positive linear relationship with green space coverage, with 'per capita GDP' having the highest independent contribution (24.2%); [5] among the climatic and geographic factors investigated, only mean elevation showed a significant effect; and [6] using the seven largest contributing individual factors, a linear model to predict variance in green space coverage was constructed. Here, we demonstrated that green space coverage in built-up areas tended to reflect the effects of urbanization rather than those of climatic or geographic factors. Quantification of the urbanization effects and the characteristics of green space development in China may provide a valuable reference for research into the processes of urban sprawl and its relationship with green space change. Copyright © 2012 Elsevier B.V. All rights reserved.
Establishing Normative Reference Values for Standing Broad Jump Among Hungarian Youth.
Saint-Maurice, Pedro F; Laurson, Kelly R; Kaj, Mónika; Csányi, Tamás
2015-06-26
The purpose of this study was to examine age and sex trends in anaerobic power assessed by a standing broad jump and to determine norm-referenced values for youth in Hungary. A sample of 2,427 Hungarian youth (1,360 boys and 1,067 girls) completed the standing broad jump twice, and the highest distance score was recorded. Quantile regression was used to fit standing broad jump trends across linear and quadratic functions of age. Statistical significance was determined with bootstrap confidence intervals and the Wald test with p < .05. Age-by-sex specific centiles were generated and the 50th percentile was used to describe the overall patterns. Standing broad jump scores increased steadily in boys from age 11 through 18 years with a discrete plateau at the end of adolescence. Girls' standing broad jump scores of those who performed above the median increased with age and plateaued later in the adolescence. Both linear and quadratic age terms were statistically significant predictors of standing broad jump trends across age (p < .05), but the relations varied depending on the percentile. The 50th percentile values resulted in 147.0 cm, 162.0 cm, 175.0 cm, 186.0 cm, 195.0 cm, 202.0 cm, 207.0 cm, and 210.0 cm for boys aged 11 to 18 years old, respectively, and 140.0 cm, 143.9 cm, 147.3 cm, 150.0 cm, 152.1 cm, 153.7 cm, 154.6 cm, and 155.0 cm for girls aged 11 to 18 years old, respectively. This study provides normative reference charts that take into account age and sex differences in standing broad jump performance. The proposed reference values can be used to interpret standing broad jump scores in Hungarian youth.
Djalalinia, Shirin; Qorbani, Mostafa; Heshmat, Ramin; Motlagh, Mohammad Esmaeil; Ardalan, Gelayol; Bazyar, Nima; Taheri, Majzoubeh; Asayesh, Hamid; Kelishadi, Roya
2015-10-01
Noncommunicable diseases (NCDs) and their risk factors are major health threats especially for developing countries. The aim of this study was to assess the association between breast feeding (BF) and birth weight (BW) with anthropometric measures and blood pressure (BP) in a nationally-representative sample of Iranian children and adolescents. In this national survey, 14,880 children and adolescents, aged 6-18 years, were selected using a multistage, cluster sampling method from rural and urban areas of 30 provinces of Iran. BF duration and BW were assessed by validated questionnaires completed by parents. The study participants were 13,486 students (participation rate of 90.6%). They consisted of 49.24% girls, 75.6% urban residents, with a mean age of 12.5 years (95% confidence interval: 12.3-12.6). The family history of obesity had a significant association with BW (p < 0.001). A substantial association was found between BF duration and the order of children in the family, both in boys (p < 0.001) and girls (p < 0.001). The mean values for height, weight, body mass index, as well as waist, wrist, and hip circumferences were higher in those with higher BW categories (p for trend < 0.001). As BW increased, there was a linear decrease in underweight (p for trend < 0.001) and a linear increase in the prevalence of generalized obesity (p for trend < 0.001) was documented. BW was associated with a higher prevalence in general obesity and a lower prevalence of being underweight. Duration of BF had no significant association with anthropometric measures and BP. Future longitudinal studies are necessary to determine the clinical implications of these findings. Copyright © 2015. Published by Elsevier B.V.
NASA Astrophysics Data System (ADS)
Sanchez-Lorenzo, Arturo; Mateos, David; Wild, Martin; Calbó, Josep; Antón, Manuel; Enriquez-Alonso, Aaron; Sanchez-Romero, Alex
2014-05-01
There is a growing interest in the study of decadal variations in surface solar radiation, although the analyses of long-term time series in some areas with major gaps in observations, such as in Spain, are still pending. In the first part of this work, a previously published surface solar radiation dataset in Spain is described (for more details, see Sanchez-Lorenzo et al., 2013) based on the longest series with ground-based records of global and diffuse solar radiation, most of them starting in the early 1980s and ending in 2012. Particular emphasis is placed upon the homogenization of this dataset in order to ensure the reliability of the trends. The linear trend in the mean annual series of global solar radiation shows a significant increase since 1981 of 4.0 Wm-2 (or 2.4 %) per decade. These results are in line with the increase of global solar radiation (i.e. brightening period) reported at many worldwide observation sites (Wild, 2009). In addition, the annual mean diffuse solar radiation series shows a significant decrease during the last three decades, but it is disturbed by strong increases in 1983 and 1991-1992, which might reflect the effects of the El Chichón and Pinatubo volcanic eruptions as a result of enhanced scattering of the aerosols emitted during these large volcanic eruptions. As clouds and aerosols are the main sources of uncertainty in the determination of the energy balance of the Earth, there is a growing interest in the evaluation of their radiative effects and their impact on the decadal variability of the surface solar radiation. Hence, in the second part of this work, the changes of the combined radiative effects of clouds and aerosols in Spain since the 1980s are investigated (for more details, see Mateos et al., 2013). In particular, the global solar radiation data above mentioned and radiative transfer simulations fed with reanalysis data of ozone, water vapour and surface albedo, are used to evaluate the cloud and aerosol radiative effect (CARE) during the 1985-2010 period. The results show a significant decrease of CARE over Spain. Overall, the linear trend of the mean annual CARE series over Spain is 3.1 Wm-2 (or 5%) per decade, in line with those trends obtained for global solar radiation during the same period. Moreover, the radiative effects of water vapour and ozone have no significant trends during the study period. In conclusion, our study in Spain supports the hypothesis usually considered to explain the widespread surface solar radiation trends by changes in aerosols and clouds (Wild, 2009). Other atmospheric variables, such as ozone column or atmospheric water vapour play a minor, almost negligible, role on these trends. References: Mateos, D., Antón, M.,Sanchez-Lorenzo, A., Calbó, J., and Wild, M. (2013): Long-term changes in the radiative effects of aerosols and clouds in a mid-latitude region (1985-2010), Global and Planetary Change, 111, 288-295. Sanchez-Lorenzo, A., Calbó, J., and Wild, M. (2013): Global and diffuse solar radiation in Spain: building a homogeneous dataset and assessing their trends, Global and Planetary Change, 100, 343- 352. Wild, M. (2009): Global dimming and brightening: a review, Journal of Geophysical Research 114, D00D16.http://dx.doi.org/10.1029/2008JD011470.
Wet-bulb, dew point, and air temperature trends in Spain
NASA Astrophysics Data System (ADS)
Moratiel, R.; Soriano, B.; Centeno, A.; Spano, D.; Snyder, R. L.
2017-10-01
This study analyses trends of mean ( T m), maximum ( T x), minimum ( T n), dew point ( T d), and wet-bulb temperatures ( T w) on an annual, seasonal, and monthly time scale over Spain during the period 1981-2010. The main purpose was to determine how temperature and humidity changes are impacting on T w, which is probably a better measure of climate change than temperature alone. In this study, 43 weather stations were used to detect data trends using the nonparametric Mann-Kendall test and the Sen method to estimate the slope of trends. Significant linear trends observed for T m, T x, and T n versus year were 56, 58, and 47 % of the weather stations, respectively, with temperature ranges between 0.2 and 0.4 °C per decade. The months with bigger trends were April, May, June, and July with the highest trend for T x. The spatial behaviour of T d and T w was variable, with various locations showing trends from -0.6 to +0.3 °C per decade for T d and from -0.4 to +0.5 °C per decade for T w. Both T d and T w showed negative trends for July, August, September, November, and December. Comparing the trends versus time of each variable versus each of the other variables exhibited poor relationships, which means you cannot predict the trend of one variable from the trend of another variable. The trend of T x was not related to the trend of T n. The trends of T x, T m, and T n versus time were unrelated to the trends versus time of either T d or T w. The trend of T w showed a high coefficient of determination with the trend of T d with an annual value of R 2 = 0.86. Therefore, the T w trend is more related to changes in humidity than temperature.
Brener, Nancy D.; McManus, Tim; Wechsler, Howell; Kann, Laura
2015-01-01
BACKGROUND Professional development (PD) and collaboration help ensure the quality of school health education. The purpose of this study was to examine trends in the percentage of lead health education teachers (LHETs) receiving PD on health topics and collaborating with other school staff on health education activities. METHODS This study analyzed representative data from 41 states participating in School Health Profiles surveys between 2000 and 2010. Logistic regression examined linear trends in the percentage of LHETs who received PD on 12 topics and who collaborated on health education activities. RESULTS Significant increases in the percentage of LHETs receiving PD on nutrition and physical activity and significant decreases in the percentage of LHETs receiving PD on alcohol- and other drug-use prevention and human immunodeficiency virus prevention were seen. Significant increases in the percentage of LHETs who collaborated with physical education staff and nutrition services staff were seen in 29 and 39 states, respectively. CONCLUSIONS Although 10-year increases in PD and collaboration in the areas of nutrition and physical activity are encouraging, PD and collaboration in other topic areas still need improvement. These results will help states target more resources toward PD and collaboration in areas where they have been decreasing. PMID:24020688
NASA Astrophysics Data System (ADS)
Visser, H.; Molenaar, J.
1995-05-01
The detection of trends in climatological data has become central to the discussion on climate change due to the enhanced greenhouse effect. To prove detection, a method is needed (i) to make inferences on significant rises or declines in trends, (ii) to take into account natural variability in climate series, and (iii) to compare output from GCMs with the trends in observed climate data. To meet these requirements, flexible mathematical tools are needed. A structural time series model is proposed with which a stochastic trend, a deterministic trend, and regression coefficients can be estimated simultaneously. The stochastic trend component is described using the class of ARIMA models. The regression component is assumed to be linear. However, the regression coefficients corresponding with the explanatory variables may be time dependent to validate this assumption. The mathematical technique used to estimate this trend-regression model is the Kaiman filter. The main features of the filter are discussed.Examples of trend estimation are given using annual mean temperatures at a single station in the Netherlands (1706-1990) and annual mean temperatures at Northern Hemisphere land stations (1851-1990). The inclusion of explanatory variables is shown by regressing the latter temperature series on four variables: Southern Oscillation index (SOI), volcanic dust index (VDI), sunspot numbers (SSN), and a simulated temperature signal, induced by increasing greenhouse gases (GHG). In all analyses, the influence of SSN on global temperatures is found to be negligible. The correlations between temperatures and SOI and VDI appear to be negative. For SOI, this correlation is significant, but for VDI it is not, probably because of a lack of volcanic eruptions during the sample period. The relation between temperatures and GHG is positive, which is in agreement with the hypothesis of a warming climate because of increasing levels of greenhouse gases. The prediction performance of the model is rather poor, and possible explanations are discussed.
Detection time for global and regional sea level trends and accelerations
NASA Astrophysics Data System (ADS)
Jordà, G.
2014-10-01
Many studies analyze trends on sea level data with the underlying purpose of finding indications of a long-term change that could be interpreted as the signature of anthropogenic climate change. The identification of a long-term trend is a signal-to-noise problem where the natural variability (the "noise") can mask the long-term trend (the "signal"). The signal-to-noise ratio depends on the magnitude of the long-term trend, on the magnitude of the natural variability, and on the length of the record, as the climate noise is larger when averaged over short time scales and becomes smaller over longer averaging periods. In this paper, we evaluate the time required to detect centennial sea level linear trends and accelerations at global and regional scales. Using model results and tide gauge observations, we find that the averaged detection time for a centennial linear trend is 87.9, 76.0, 59.3, 40.3, and 25.2 years for trends of 0.5, 1.0, 2.0, 5.0, and 10.0 mm/yr, respectively. However, in regions with large decadal variations like the Gulf Stream or the Circumpolar current, these values can increase up to a 50%. The spatial pattern of the detection time for sea level accelerations is almost identical. The main difference is that the length of the records has to be about 40-60 years longer to detect an acceleration than to detect a linear trend leading to an equivalent change after 100 years. Finally, we have used a new sea level reconstruction, which provides a more accurate representation of interannual variability for the last century in order to estimate the detection time for global mean sea level trends and accelerations. Our results suggest that the signature of natural variability in a 30 year global mean sea level record would be less than 1 mm/yr. Therefore, at least 2.2 mm/yr of the recent sea level trend estimated by altimetry cannot be attributed to natural multidecadal variability. This article was corrected on 19 NOV 2014. See the end of the full text for details.
Pan, Stephen W; Chong, Hiu Ha; Kao, Hui-Chuan
2017-11-27
Indigenous communities in Taiwan shoulder a disproportionate burden of unintentional injury fatalities. We compare unintentional injury mortality rate trends among Taiwan's indigenous communities and the general population from 2002 to 2013, and evaluate potential impact of a community-based injury prevention programme on indigenous unintentional injury death rates. Standardised and crude unintentional injury mortality rates were obtained from Taiwan government reports. Segmented linear regression was used to estimate and compare unintentional injury mortality rate trends before and after the intervention. Between 2002 and 2013, unintentional injury mortality rates among Taiwan's indigenous population significantly declined by about 4.5 deaths per 100 000 each year (p<0.0001). During that time, the unintentional injury mortality rate ratio between indigenous Taiwanese and the general population significantly decreased by approximately 1% each successive year (p=0.02). However, we were unable to detect evidence that the 'Healthy and Safe Tribe' programme was associated with a statistically significant decrease in the unintentional injury mortality rate trend among indigenous persons (p=0.81). Taiwanese indigenous communities remain at significantly higher risk of unintentional injury death, though the gap may be slowly narrowing. We found no evidence that the 'Healthy and Safe Tribe' indigenous injury-prevention programme significantly contributed to the nationwide decline in unintentional injury mortality among indigenous Taiwanese communities from 2009 to 2013. Future interventions to address the disproportionate burden of unintentional injury fatalities among indigenous Taiwanese should consider interventions with wider coverage of the indigenous population, and complementing grass roots led community-based interventions with structural policy interventions as well. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
NASA Astrophysics Data System (ADS)
Irie, H.; Muto, T.; Itahashi, S.; Kurokawa, J. I.
2015-12-01
The Ozone Monitoring Instrument (OMI) aboard the Aura satellite recorded the 10-year (2005-2014) of tropospheric nitrogen dioxide (NO2) vertical column density (VCD) data. The data set taken over East Asia was analyzed to estimate linear trends on national and grid bases for two periods of 2005-2011 and 2011-2014. The most striking features are leveling-off or decreasing trends seen in NO2 VCDs over China for 2011-2014 after continuous increases for 2005-2011. In particular, a significant reduction by ~14% occurred from 2013 through 2014, attaining to the level of 2009. The grid-basis trend analysis implies that the turnaround seen in the trends occurred on a province or larger spatial scale and was likely due mainly to the technical improvement such as the widespread use of de-NOx units. Another prominent features are seen in Japan, where NO2 VCDs decreased at a rate of ~4% per year from 2005 to 2011. The rate was almost unchanged between the two periods 2005-2011 and 2011-2014, while the significant power substitution of thermal power generation for the nuclear power generation took place in Japan after 2011, when a massive earthquake occurred off the Pacific coast of northern Japan. This reflects a less contribution of NOx emissions from the power plant sector than that from the transport sector in the Pacific Belt Zone lying over metropolitan areas.
Trends in US movie tobacco portrayal since 1950: a historical analysis.
Jamieson, Patrick E; Romer, Dan
2010-06-01
Portrayal of tobacco use in films has been causally linked to youth smoking initiation. However, findings regarding trends in portrayal in US films since 1950 are inconsistent, potentially due to differences in sampling densities, intercoder reliabilities and time periods covered. The present study was designed to overcome these inconsistencies with a common sampling frame and methodology. A half sample of the 30 top-grossing US films per year from 1950 to 2006 (N=855) was coded in 5-min segments for total tobacco-related content and main character tobacco use. Film tobacco trends were identified using linear regression and compared to national per capita cigarette consumption and historically significant tobacco control events. Tobacco content declined considerably since 1950. Total tobacco-related content peaked around 1961, while the decline in portrayal of main character use was already underway in 1950. Cigarette consumption peaked around 1966 with a trend that closely paralleled total tobacco content and that coincided with major tobacco control events. This study, which had high reliability, dense sampling and covered a long time period, indicates that tobacco content has declined in top-ranked US movies since 1950 with a trend in total tobacco content that closely paralleled the drop in per capita cigarette consumption and the increase in significant tobacco control efforts. Despite the inability to draw causal conclusions, tobacco portrayal in films may serve as barometer of societal support for the habit and thus efforts should continue to limit exposure to such content.
Have Tropical Cyclones Been Feeding More Extreme Rainfall?
NASA Technical Reports Server (NTRS)
Lau, K.-M.; Zhou, Y. P.; Wu, H.-T.
2008-01-01
We have conducted a study of the relationship between tropical cyclone (TC) and extreme rain events using GPCP and TRMM rainfall data, and storm track data for July through November (JASON) in the North Atlantic (NAT) and the western North Pacific (WNP). Extreme rain events are defined in terms of percentile rainrate, and TC-rain by rainfall associated with a named TC. Results show that climatologically, 8% of rain events and 17% of the total rain amount in NAT are accounted by TCs, compared to 9% of rain events and 21% of rain amount in WNP. The fractional contribution of accumulated TC-rain to total rain, Omega, increases nearly linearly as a function of rainrate. Extending the analyses using GPCP pentad data for 1979-2005, and for the post-SSM/I period (1988-2005), we find that while there is no significant trend in the total JASON rainfall over NAT or WNP, there is a positive significant trend in heavy rain over both basins for the 1979-2005 period, but not for the post-SSM/I period. Trend analyses of Omega for both periods indicate that TCs have been feeding increasingly more to rainfall extremes in NAT, where the expansion of the warm pool area can explain slight more than 50% of the change in observed trend in total TC rainfall. In WNP, trend signals for Omega are mixed, and the long-term relationship between TC rain and warm pool areas are strongly influenced by interannual and interdecadal variability.
Gerke, Alicia K; Tang, Fan; Cavanaugh, Joseph E; Doerschug, Kevin C; Polgreen, Philip M
2015-11-18
Extracorporeal membrane oxygenation (ECMO) has been increasingly studied as a life support modality, but it is unclear if its use has changed over time. Recent publication shows no significant trend in use of ECMO over time; however, this report does not include more recent data. We performed trend analysis to determine if and when the use of ECMO changed in the past decade. We identified hospitalizations (2000-2011) in the Nationwide Inpatient Sample during which ECMO was recorded. We used a segmented linear regression model to determine trend and to identify a temporal change point when rate of ECMO use increased. ECMO use gradually grew until 2007, at which time there was a dramatic increase in the rate (p = 0.0003). There was no difference in mortality after 2007 (p = 0.3374), but there was longer length of stay (p = 0.0001) and smaller percentage of women (p = 0.005). There has been a marked increase in ECMO use since 2007. As ECMO use becomes more common, further study regarding indications, cost-effectiveness, and outcomes is warranted to guide optimal use.
NASA Astrophysics Data System (ADS)
Li, Zhen; Pan, Jinghu
2018-03-01
Net primary productivity (NPP) is recognized as an important index of ecosystem conditions and a key variable of the terrestrial carbon cycle. It also represents the comprehensive effects of climate change and anthropogenic activity on terrestrial vegetation. In this study, the temporal-spatial pattern of NPP for the period 2001-2012 was analyzed using a remote sensing-based carbon model (i.e., the Carnegie-Ames-Stanford Approach, CASA) in addition to other methods, such as linear trend analysis, standard deviation, and the Hurst index. Temporally, NPP showed a significant increasing trend for the arid region of Northwest China (ARNC), with an annual increase of 2.327 g C. Maximum and minimum productivity values appeared in July and December, respectively. Spatially, the NPP was relatively stable in the temperate and warm-temperate desert regions of Northwest China, while temporally, it showed an increasing trend. However, some attention should be given to the northwestern warm-temperate desert region, where there is severe continuous degradation and only a slight improvement trend.
Onozuka, Daisuke; Hagihara, Akihito
2015-07-01
Although the impact of extreme heat and cold on mortality has been documented in recent years, few studies have investigated whether variation in susceptibility to extreme temperatures has changed in Japan. We used data on daily total mortality and mean temperatures in Fukuoka, Japan, for 1973-2012. We used time-series analysis to assess the effects of extreme hot and low temperatures on all-cause mortality, stratified by decade, gender, and age, adjusting for time trends. We used a multivariate meta-analysis with a distributed lag non-linear model to estimate pooled non-linear lag-response relationships associated with extreme temperatures on mortality. The relative risk of mortality increased during heat extremes in all decades, with a declining trend over time. The mortality risk was higher during cold extremes for the entire study period, with a dispersed pattern across decades. Meta-analysis showed that both heat and cold extremes increased the risk of mortality. Cold effects were delayed and lasted for several days, whereas heat effects appeared quickly and did not last long. Our study provides quantitative evidence that extreme heat and low temperatures were significantly and non-linearly associated with the increased risk of mortality with substantial variation. Our results suggest that timely preventative measures are important for extreme high temperatures, whereas several days' protection should be provided for extreme low temperatures. Copyright © 2015 Elsevier Inc. All rights reserved.
Trends in asthma mortality in the 0- to 4-year and 5- to 34-year age groups in Brazil.
Graudenz, Gustavo Silveira; Carneiro, Dominique Piacenti; Vieira, Rodolfo de Paula
2017-01-01
To provide an update on trends in asthma mortality in Brazil for two age groups: 0-4 years and 5-34 years. Data on mortality from asthma, as defined in the International Classification of Diseases, were obtained for the 1980-2014 period from the Mortality Database maintained by the Information Technology Department of the Brazilian Unified Health Care System. To analyze time trends in standardized asthma mortality rates, we conducted an ecological time-series study, using regression models for the 0- to 4-year and 5- to 34-year age groups. There was a linear trend toward a decrease in asthma mortality in both age groups, whereas there was a third-order polynomial fit in the general population. Although asthma mortality showed a consistent, linear decrease in individuals ≤ 34 years of age, the rate of decline was greater in the 0- to 4-year age group. The 5- to 34-year group also showed a linear decline in mortality, and the rate of that decline increased after the year 2004, when treatment with inhaled corticosteroids became more widely available. The linear decrease in asthma mortality found in both age groups contrasts with the nonlinear trend observed in the general population of Brazil. The introduction of inhaled corticosteroid use through public policies to control asthma coincided with a significant decrease in asthma mortality rates in both subsets of individuals over 5 years of age. The causes of this decline in asthma-related mortality in younger age groups continue to constitute a matter of debate. Apresentar uma atualização das tendências da mortalidade da asma no Brasil em duas faixas etárias: 0-4 anos e 5-34 anos. Dados relativos ao período de 1980 a 2014 referentes à mortalidade da asma, conforme se definiu na Classificação Internacional de Doenças, foram extraídos Sistema de Informação sobre Mortalidade do Departamento de Tecnologia da Informação do Sistema Único de Saúde. Para analisar as tendências temporais das taxas padronizadas de mortalidade da asma, realizou-se um estudo ecológico de séries temporais com modelos de regressão para as faixas etárias de 0 a 4 anos e 5 a 34 anos. Houve uma tendência linear de redução da mortalidade da asma em ambas as faixas etárias e uma tendência polinomial de terceira ordem na população geral. Embora a mortalidade da asma tenha apresentado redução linear consistente em indivíduos com idade ≤ 34 anos, a taxa de declínio foi maior na faixa etária de 0 a 4 anos. A faixa etária de 5 a 34 anos também apresentou redução linear da mortalidade, e essa redução tornou-se mais pronunciada após o ano de 2004, quando o tratamento com corticosteroides inalatórios tornou-se mais amplamente disponível. A redução linear da mortalidade da asma em ambas as faixas etárias contrasta com a tendência não linear observada na população geral do Brasil. A introdução do uso de corticosteroides inalatórios por meio de políticas públicas de controle da asma coincidiu com uma diminuição significativa das taxas de mortalidade da asma em ambos os subgrupos de indivíduos com mais de 5 anos de idade. As causas dessa redução da mortalidade da asma em faixas etárias mais jovens ainda são objeto de debate.
Consumption of added sugars is decreasing in the United States.
Welsh, Jean A; Sharma, Andrea J; Grellinger, Lisa; Vos, Miriam B
2011-09-01
The consumption of added sugars (caloric sweeteners) has been linked to obesity, diabetes, and heart disease. Little is known about recent consumption trends in the United States or how intakes compare with current guidelines. We examined trends in intakes of added sugars in the United States over the past decade. A cross-sectional study of US residents ≥2 y of age (n = 42,316) was conducted by using dietary data from NHANES 1999-2008 (five 2-y cycles) and data for added-sugar contents from the MyPyramid Equivalents Database. Mean intakes of added sugars (grams and percentage of total energy intake) were weighted to obtain national estimates over time across age, sex, and race-ethnic groups. Linear trends were tested by using Wald's F tests. Between 1999-2000 and 2007-2008, the absolute intake of added sugars decreased from a mean (95% CI) of 100.1 g/d (92.8, 107.3 g/d) to 76.7 g/d (71.6, 81.9 g/d); two-thirds of this decrease, from 37.4 g/d (32.6, 42.1 g/d) to 22.8 g/d (18.4, 27.3 g/d), resulted from decreased soda consumption (P-linear trend <0.001 for both). Energy drinks were the only source of added sugars to increase over the study period (P-linear trend = 0.003), although the peak consumption reached only 0.15 g/d (0.08, 0.22 g/d). The percentage of total energy from added sugars also decreased from 18.1% (16.9%, 19.3%) to 14.6% (13.7%, 15.5%) (P-linear trend <0.001). Although the consumption of added sugars in the United States decreased between 1999-2000 and 2007-2008, primarily because of a reduction in soda consumption, mean intakes continue to exceed recommended limits.
Consumption of added sugars is decreasing in the United States1234
Sharma, Andrea J; Grellinger, Lisa; Vos, Miriam B
2011-01-01
Background: The consumption of added sugars (caloric sweeteners) has been linked to obesity, diabetes, and heart disease. Little is known about recent consumption trends in the United States or how intakes compare with current guidelines. Objective: We examined trends in intakes of added sugars in the United States over the past decade. Design: A cross-sectional study of US residents ≥2 y of age (n = 42,316) was conducted by using dietary data from NHANES 1999–2008 (five 2-y cycles) and data for added-sugar contents from the MyPyramid Equivalents Database. Mean intakes of added sugars (grams and percentage of total energy intake) were weighted to obtain national estimates over time across age, sex, and race-ethnic groups. Linear trends were tested by using Wald's F tests. Results: Between 1999–2000 and 2007–2008, the absolute intake of added sugars decreased from a mean (95% CI) of 100.1 g/d (92.8, 107.3 g/d) to 76.7 g/d (71.6, 81.9 g/d); two-thirds of this decrease, from 37.4 g/d (32.6, 42.1 g/d) to 22.8 g/d (18.4, 27.3 g/d), resulted from decreased soda consumption (P-linear trend <0.001 for both). Energy drinks were the only source of added sugars to increase over the study period (P-linear trend = 0.003), although the peak consumption reached only 0.15 g/d (0.08, 0.22 g/d). The percentage of total energy from added sugars also decreased from 18.1% (16.9%, 19.3%) to 14.6% (13.7%, 15.5%) (P-linear trend <0.001). Conclusion: Although the consumption of added sugars in the United States decreased between 1999–2000 and 2007–2008, primarily because of a reduction in soda consumption, mean intakes continue to exceed recommended limits. PMID:21753067
Interannual variability in stratiform cloudiness and sea surface temperature
NASA Technical Reports Server (NTRS)
Norris, Joel R.; Leovy, Conway B.
1994-01-01
Marine stratiform cloudiness (MSC)(stratus, stratocumulus, and fog) is widespread over subtropical oceans west of the continents and over midlatitude oceans during summer, the season when MSC has maximum influence on surface downward radiation and is most influenced by boundary-layer processes. Long-term datasets of cloudiness and sea surface teperature (SST) from surface observations from 1952 to 1981 are used to examine interannual variations in MSC and SST. Linear correlations of anomalies in seasonal MSC amount with seasonal SST anomalies are negative and significant in midlatitude and eastern subtropical oceans, especially during summer. Significant negative correlations between SST and nimbostratus and nonprecipitating midlevel cloudiness are also observed at midlatitudes during summer, suggesting that summer storm tracks shift from year to year following year-to-year meridional shifts in the SST gradient. Over the 30-yr period, there are significant upward trends in MSC amount over the northern midlatitude oceans and a significant downward trend off the coast of California. The highest correlations and trends occur where gradients in MSC and SST are strongest. During summer, correlations between SST and MSC anomalies peak at zero lag in midlatitudes where warm advection prevails, but SST lags MSC in subtropical regions where cold advection predominates. This difference is attributed to a tendency for anomalies in latent heat flux to compensate anomalies in surface downward radiation in warm advection regions but not in cold advection regions.
Burr, David B.; Liu, Ziyue; Allen, Matthew R.
2014-01-01
Bisphosphonates (BPs) have been shown to significantly reduce bone toughness in vertebrae within one year when given at clinical doses to dogs. Although BPs also reduce toughness in cortical bone when given at high doses, their effect on cortical bone material properties when given at clinical doses is less clear. In part, this may be due to the use of small sample sizes that were powered to demonstrate differences in bone mineral density rather than bone’s material properties. Our lab has conducted several studies in which dogs were treated with alendronate at a clinically relevant dose. The goal of this study was to examine these published and unpublished data collectively to determine whether there is a significant time-dependent effect of alendronate on toughness of cortical bone. This analysis seemed particularly relevant given the recent occurrence of atypical femoral fractures in humans. Differences in the toughness of ribs taken from dogs derived from five separate experiments were measured. The dogs were orally administered saline (CON, 1 ml/kg/day) or alendronate (ALN) at a clinical dose (0.2 mg/kg/day). Treatment duration ranged from 3 months to 3 years. Groups were compared using ANOVA, and time trends analyzed with linear regression analysis. Linear regressions of the percent difference in toughness between CON and ALN at each time point revealed a significant reduction in toughness with longer exposure to ALN. The downward trend was primarily driven by a downward trend in post-yield toughness, whereas toughness in the pre-yield region was not changed relative to CON. These data suggest that a longer duration of treatment with clinical doses of ALN results in deterioration of cortical bone toughness in a time-dependent manner. As the duration of treatment is lengthened, the cortical bone exhibits increasingly brittle behavior. This may be important in assessing the role that long-term BP treatments play in the risk of atypical fractures of femoral cortical bone in humans. PMID:25445446
Camp, Richard J.; Pratt, Thane K.; Gorresen, P. Marcos; Woodworth, Bethany L.; Jeffrey, John J.
2014-01-01
Freed and Cann (2013) criticized our use of linear models to assess trends in the status of Hawaiian forest birds through time (Camp et al. 2009a, 2009b, 2010) by questioning our sampling scheme, whether we met model assumptions, and whether we ignored short-term changes in the population time series. In the present paper, we address these concerns and reiterate that our results do not support the position of Freed and Cann (2013) that the forest birds in the Hakalau Forest National Wildlife Refuge (NWR) are declining, or that the federally listed endangered birds are showing signs of imminent collapse. On the contrary, our data indicate that the 21-year long-term trends for native birds in Hakalau Forest NWR are stable to increasing, especially in areas that have received active management.
Zeng, Lixi; Lam, James C W; Wang, Yawei; Jiang, Guibin; Lam, Paul K S
2015-10-06
Temporal trends of short- (SCCPs) and medium-chain chlorinated paraffins (MCCPs) were examined in blubber samples of 50 finless porpoises (Neophocaena phocaenoides) and 25 Indo-Pacific humpback dolphins (Sousa chinensis) collected from the South China Sea between 2004 and 2014. Elevated levels of SCCPs and MCCPs were detected in all blubber samples of both cetacean species. Concentrations of SCCPs ranged from 280 to 3900 ng·g(-1) dry weight (dw) in porpoises and from 430 to 9100 ng·g(-1) dw in dolphins, while concentrations of MCCPs ranged from 320 to 8600 ng·g(-1) dw in porpoises and from 530 to 23 000 ng·g(-1) dw in dolphins. Significantly higher concentrations were present in dolphins than porpoises due to their exposure levels in their living habitats. Strongly linear correlations existed between SCCPs and MCCPs, but there were no significant concentration differences between the genders of the two cetacean species in the same sampling year. Significantly temporal increasing trends of ∑SCCPs and ∑MCCPs have been observed in both porpoise and dolphin samples over the past decade, which reflect the influence of histories of production and usage on the bioaccumulation of CPs in marine mammals in China. An apparent temporal shift trend from SCCPs to MCCPs was also observed in CP accumulation profiles. Complex environmental fractionation from localized sources in the study region via atmospheric transport, oceanic/offshore water transport, and trophic transfer have resulted in different CP accumulation levels and homologue patterns in the two cetacean species. This is the first report of systematic temporal trends of SCCPs and MCCPs in marine mammals.
Bellinger, Adam S; Elliott, Sean P; Yang, Liu; Wei, John T; Saigal, Christopher S; Smith, Alexandria; Wilt, Timothy J; Strope, Seth A
2012-05-01
Benign prostatic hyperplasia creates significant expenses for the Medicare program. We determined expenditure trends for benign prostatic hyperplasia evaluative testing after urologist consultation and placed these trends in the context of overall Medicare expenditures. Using a 5% national sample of Medicare beneficiaries from 2000 to 2007 we developed a cohort of 40,253 with claims for new visits to urologists for diagnoses consistent with symptomatic benign prostatic hyperplasia. We assessed trends in initial inflation and geography adjusted expenditures within 12 months of diagnosis by evaluative test categories derived from the 2003 American Urological Association guideline on the management of benign prostatic hyperplasia. Using governmental reports on Medicare expenditure trends for benign prostatic hyperplasia we compared expenditures to overall and imaging specific Medicare expenditures. Comparisons were assessed by the Z-test and regression analysis for linear trends, as appropriate. Between 2000 and 2007 inflation adjusted total Medicare expenditures per patient for the initial evaluation of patients with benign prostatic hyperplasia seen by urologists increased from $255.44 to $343.98 (p <0.0001). Benign prostatic hyperplasia related imaging increases were significantly less than overall Medicare imaging expenditure increases (55% vs 104%, p <0.001). The increase in per patient expenditures for benign prostatic hyperplasia was significantly lower than the increase in overall Medicare expenditures per enrollee (35% vs 45%, p = 0.0015). From 2000 to 2007 inflation adjusted expenditures increased for benign prostatic hyperplasia related evaluations. This growth was slower than the overall growth in Medicare expenditures. The increase in BPH related imaging expenditures was restrained compared to that of the Medicare program as a whole. Copyright © 2012 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.
Knapik, Joseph J; T Jean, Rosenie; Austin, Krista G; Steelman, Ryan A; Gannon, Julia; Farina, Emily K; Lieberman, Harris R
2016-10-01
Dietary supplements (DSs) can be obtained over-the-counter but can also be prescribed by health-care providers for therapeutic reasons. Few studies have documented this later source despite the fact that 79% of physicians and 82% of nurses have recommended DSs to patients. This investigation assessed prevalence and temporal trends in oral DS prescriptions filled by all United States service members (SMs) from 2005 to 2013 (n = 1 427 080 ± 22 139, mean ± standard deviation (SD)/y). We hypothesize that there would be temporal variations in specific types of DSs. Data obtained from Department of Defense Pharmacy Data Transaction System were grouped by American Hospital Formulary System pharmacologic-therapeutic classifications and prevalence examined over time. About 11% of SMs filled one or more DS prescriptions of 235 180 ± 4926 (mean ± SD) prescriptions/y over the 9-year period. Curve-fitting techniques indicated significant linear declines over time for multivitamins (P = .004), iron preparations (P < .001), antacids (P < .001), and vitamin B and B complex vitamins (P < .001). There were significant quadratic trends indicating a rise in early years followed by a leveling off in later years for replacement preparations (P < .001) and vitamin C (P < .001). There were significant quadratic trends (P < .001) for vitamin E indicating a decline in early years and leveling off in later years, and vitamin D indicating little change in early years followed by a large rise subsequently (P < .001). This study identified temporal trends in specific DS categories that may be associated with changing perceptions of prescribers and/or patients of the appropriate roles of DSs in medicine and public health. Published by Elsevier Inc.
Hysterectomy trends in Australia, 2000-2001 to 2013-2014: joinpoint regression analysis.
Wilson, Louise F; Pandeya, Nirmala; Mishra, Gita D
2017-10-01
Hysterectomy is a common gynecological procedure, particularly in middle and high income countries. The aim of this paper was to describe and examine hysterectomy trends in Australia from 2000-2001 to 2013-2014. For women aged 25 years and over, data on the number of hysterectomies performed in Australia annually were sourced from the National Hospital and Morbidity Database. Age-specific and age-standardized hysterectomy rates per 10 000 women were estimated with adjustment for hysterectomy prevalence in the population. Using joinpoint regression analysis, we estimated the average annual percentage change over the whole study period (2000-2014) and the annual percentage change for each identified trend line segment. A total of 431 162 hysterectomy procedures were performed between 2000-2001 and 2013-2014; an annual average of 30 797 procedures (for women aged 25+ years). The age-standardized hysterectomy rate, adjusted for underlying hysterectomy prevalence, decreased significantly over the whole study period [average annual percentage change -2.8%; 95% confidence interval (CI) -3.5%, -2.2%]. The trend was not linear with one joinpoint detected in 2008-2009. Between 2000-2001 and 2008-2009 there was a significant decrease in incidence (annual percentage change -4.4%; 95% CI -5.2%, -3.7%); from 2008-2009 to 2013-2014 the decrease was minimal and not significantly different from zero (annual percentage change -0.1%; 95% CI -1.7%, 1.5%). A similar change in trend was seen in all age groups. Hysterectomy rates in Australian women aged 25 years and over have declined in the first decade of the 21st century. However, in the last 5 years, rates appear to have stabilized. © 2017 Nordic Federation of Societies of Obstetrics and Gynecology.
NASA Astrophysics Data System (ADS)
Gao, Tao; Xie, Lian
2016-12-01
Precipitation extremes are the dominated causes for the formation of severe flood disasters at regional and local scales under the background of global climate change. In the present study, five annual extreme precipitation events, including 1, 7 and 30 day annual maximum rainfall and 95th and 97.5th percentile threshold levels, are analyzed relating to the reference period 1960-2011 from 140 meteorological stations over Yangtze River basin (YRB). A generalized extreme value (GEV) distribution is applied to fit annual and percentile extreme precipitation events at each station with return periods up to 200 years. The entire time period is divided into preclimatic (preceding climatic) period 1960-1980 and aftclimatic (after climatic) period 1981-2011 by considering distinctly abrupt shift of precipitation regime in the late 1970s across YRB. And the Mann-Kendall trend test is adopted to conduct trend analysis during pre- and aftclimatic periods, respectively, for the purpose of exploring possible increasing/decreasing patterns in precipitation extremes. The results indicate that the increasing trends for return values during aftclimatic period change significantly in time and space in terms of different magnitudes of extreme precipitation, while the stations with significantly positive trends are mainly distributed in the vicinity of the mainstream and major tributaries as well as large lakes, this would result in more tremendous flood disasters in the mid-lower reaches of YRB, especially in southeast coastal regions. The increasing/decreasing linear trends based on annual maximum precipitation are also investigated in pre- and aftclimatic periods, respectively, whereas those changes are not significantly similar to the variations of return values during both subperiods. Moreover, spatiotemporal patterns of precipitation extremes become more uneven and unstable in the second half period over YRB.
Dietary arginine and linear growth: the Copenhagen School Child Intervention Study.
van Vught, Anneke J A H; Dagnelie, Pieter C; Arts, Ilja C W; Froberg, Karsten; Andersen, Lars B; El-Naaman, Bianca; Bugge, Anna; Nielsen, Birgit M; Heitman, Berit L
2013-03-28
The amino acid arginine is a well-known growth hormone (GH) stimulator and GH is an important modulator of linear growth. The aim of the present study was to investigate the effect of dietary arginine on growth velocity in children between 7 and 13 years of age. Data from the Copenhagen School Child Intervention Study during 2001-2 (baseline), and at 3-year and 7-year follow-up, were used. Arginine intake was estimated via a 7 d precoded food diary at baseline and 3-year follow-up. Data were analysed in a multilevel structure in which children were embedded within schools. Random intercept and slopes were defined to estimate the association between arginine intake and growth velocity, including the following covariates: sex; age; baseline height; energy intake; puberty stage at 7-year follow-up and intervention/control group. The association between arginine intake and growth velocity was significant for the third and fourth quintile of arginine intake (2.5-2.8 and 2.8-3.2 g/d, respectively) compared with the first quintile ( < 2.2 g/d) (P for trend = 0.04). Protein intake (excluding arginine) was significantly associated with growth velocity; however, the association was weaker than the association between arginine intake and growth velocity (P for trend = 0.14). The results of the present study suggest a dose-dependent physiological role of habitual protein intake, and specifically arginine intake, on linear growth in normally growing children. However, since the study was designed in healthy children, we cannot firmly conclude whether arginine supplementation represents a relevant clinical strategy. Further research is needed to investigate whether dietary arginine may represent a nutritional strategy potentially advantageous for the prevention and treatment of short stature.
Association of Internet search trends with suicide death in Taipei City, Taiwan, 2004-2009.
Yang, Albert C; Tsai, Shi-Jen; Huang, Norden E; Peng, Chung-Kang
2011-07-01
Although Internet has become an important source for affected people seeking suicide information, the connection between Internet searches for suicide information and suicidal death remains largely unknown. This study aims to evaluate the association between suicide and Internet searches trends for 37 suicide-related terms representing major known risks of suicide. This study analyzes suicide death data in Taipei City, Taiwan and corresponding local Internet search trend data provided by Google Insights for Search during the period from January 2004 to December 2009. The investigation uses cross correlation analysis to estimate the temporal relationship between suicide and Internet search trends and multiple linear regression analysis to identify significant factors associated with suicide from a pool of search trend data that either coincides or precedes the suicide death. Results show that a set of suicide-related search terms, the trends of which either temporally coincided or preceded trends of suicide data, were associated with suicide death. These search factors varied among different suicide samples. Searches for "major depression" and "divorce" accounted for, at most, 30.2% of the variance in suicide data. When considering only leading suicide trends, searches for "divorce" and the pro-suicide term "complete guide of suicide," accounted for 22.7% of variance in suicide data. Appropriate filtering and detection of potentially harmful source in keyword-driven search results by search engine providers may be a reasonable strategy to reduce suicide deaths. Copyright © 2011 Elsevier B.V. All rights reserved.
Comparison of Recent Modeled and Observed Trends in Total Column Ozone
NASA Technical Reports Server (NTRS)
Andersen, S. B.; Weatherhead, E. C.; Stevermer, A.; Austin, J.; Bruehl, C.; Fleming, E. L.; deGrandpre, J.; Grewe, V.; Isaksen, I.; Pitari, G.;
2006-01-01
We present a comparison of trends in total column ozone from 10 two-dimensional and 4 three-dimensional models and solar backscatter ultraviolet-2 (SBUV/2) satellite observations from the period 1979-2003. Trends for the past (1979-2000), the recent 7 years (1996-2003), and the future (2000-2050) are compared. We have analyzed the data using both simple linear trends and linear trends derived with a hockey stick method including a turnaround point in 1996. If the last 7 years, 1996-2003, are analyzed in isolation, the SBUV/2 observations show no increase in ozone, and most of the models predict continued depletion, although at a lesser rate. In sharp contrast to this, the recent data show positive trends for the Northern and the Southern Hemispheres if the hockey stick method with a turnaround point in 1996 is employed for the models and observations. The analysis shows that the observed positive trends in both hemispheres in the recent 7-year period are much larger than what is predicted by the models. The trends derived with the hockey stick method are very dependent on the values just before the turnaround point. The analysis of the recent data therefore depends greatly on these years being representative of the overall trend. Most models underestimate the past trends at middle and high latitudes. This is particularly pronounced in the Northern Hemisphere. Quantitatively, there is much disagreement among the models concerning future trends. However, the models agree that future trends are expected to be positive and less than half the magnitude of the past downward trends. Examination of the model projections shows that there is virtually no correlation between the past and future trends from the individual models.
Comparison of recent modeled and observed trends in total column ozone
NASA Astrophysics Data System (ADS)
Andersen, S. B.; Weatherhead, E. C.; Stevermer, A.; Austin, J.; Brühl, C.; Fleming, E. L.; de Grandpré, J.; Grewe, V.; Isaksen, I.; Pitari, G.; Portmann, R. W.; Rognerud, B.; Rosenfield, J. E.; Smyshlyaev, S.; Nagashima, T.; Velders, G. J. M.; Weisenstein, D. K.; Xia, J.
2006-01-01
We present a comparison of trends in total column ozone from 10 two-dimensional and 4 three-dimensional models and solar backscatter ultraviolet-2 (SBUV/2) satellite observations from the period 1979-2003. Trends for the past (1979-2000), the recent 7 years (1996-2003), and the future (2000-2050) are compared. We have analyzed the data using both simple linear trends and linear trends derived with a hockey stick method including a turnaround point in 1996. If the last 7 years, 1996-2003, are analyzed in isolation, the SBUV/2 observations show no increase in ozone, and most of the models predict continued depletion, although at a lesser rate. In sharp contrast to this, the recent data show positive trends for the Northern and the Southern Hemispheres if the hockey stick method with a turnaround point in 1996 is employed for the models and observations. The analysis shows that the observed positive trends in both hemispheres in the recent 7-year period are much larger than what is predicted by the models. The trends derived with the hockey stick method are very dependent on the values just before the turnaround point. The analysis of the recent data therefore depends greatly on these years being representative of the overall trend. Most models underestimate the past trends at middle and high latitudes. This is particularly pronounced in the Northern Hemisphere. Quantitatively, there is much disagreement among the models concerning future trends. However, the models agree that future trends are expected to be positive and less than half the magnitude of the past downward trends. Examination of the model projections shows that there is virtually no correlation between the past and future trends from the individual models.
Thyroid hormones and coronary artery calcification in euthyroid men and women.
Zhang, Yiyi; Kim, Bo-Kyoung; Chang, Yoosoo; Ryu, Seungho; Cho, Juhee; Lee, Won-Young; Rhee, Eun-Jung; Kwon, Min-Jung; Rampal, Sanjay; Zhao, Di; Pastor-Barriuso, Roberto; Lima, Joao A; Shin, Hocheol; Guallar, Eliseo
2014-09-01
Overt and subclinical hypothyroidism are risk factors for atherosclerosis. It is unclear whether thyroid hormone levels within the normal range are also associated with atherosclerosis measured by coronary artery calcium (CAC). We conducted a cross-sectional study of 41 403 apparently healthy young and middle-aged men and women with normal thyroid hormone levels. Free thyroxin, free triiodothyronine, and thyroid-stimulating hormone levels were measured by electrochemiluminescent immunoassay. CAC score was measured by multidetector computed tomography. The multivariable adjusted CAC ratios comparing the highest versus the lowest quartile of thyroid hormones were 0.74 (95% confidence interval, 0.60-0.91; P for trend <0.001) for free thyroxin, 0.81 (0.66-1.00; P for trend=0.05) for free triiodothyronine, and 0.78 (0.64-0.95; P for trend=0.01) for thyroid-stimulating hormone. Similarly, the odds ratios for detectable CAC (CAC >0) comparing the highest versus the lowest quartiles of thyroid hormones were 0.87 (0.79-0.96; P for linear trend <0.001) for free thyroxin, 0.90 (0.82-0.99; P for linear trend=0.02) for free triiodothyronine, and 0.91 (0.83-1.00; P for linear trend=0.03) for thyroid-stimulating hormone. In a large cohort of apparently healthy young and middle-aged euthyroid men and women, low-normal free thyroxin and thyroid-stimulating hormone were associated with a higher prevalence of subclinical coronary artery disease and with a greater degree of coronary calcification. © 2014 American Heart Association, Inc.
NASA Technical Reports Server (NTRS)
Lee, K. (Principal Investigator); Sawatzky, D. L.
1974-01-01
The author has identified the following significant results. Shadow enhancement of topographic linears in photographic or scanner images is a valuable tool for interpretation of geologic structures. Whether linears will be enhanced or subdued depends on sun angle and azimuth. The relationship of the sun's attitude to topographic slopes determines which trends are available for interpretation in existing imagery, and it can be used to select the time of day, surface properties, and film and filter characteristics in planning aircraft flights or satellite orbital passes. The technique of selective shadow enhancement can be applied to all photographic or imaging experiments, but its best for snow-covered scenes, side-looking radar images, and painted relief models.
Riparian Bird Population Monitoring in Utah, 1992-2001
Russell E. Norvell; Frank P. Howe; Jimmie R. Parrish
2005-01-01
We report statewide linear and non-linear trends in density from 1992 to 2001 for six common bird species in the riparian areas of Utah. The six species examined here represent over 24 percent of all observations in the period. Four of the six species showed linear declines (Black-headed Grosbeak [Pheucticus melanocephalus], American Goldfinch [
NASA Astrophysics Data System (ADS)
Dufour, G.; Eremenko, M.; Lachâtre, M.; Hauglustaine, D.; Fortems-Cheiney, A.; Cuesta, J.; Zhang, Y.; Cai, Z.; Liu, Y.; Xu, X.; Lin, W.; Cooper, O. R.
2017-12-01
China, and especially the North China Plain (NCP), is a highly polluted region. Emission reductions have been applied since about 10 years, starting with SO2 emissions in 2006 and with NOx emissions in 2010. Recent satellite observations series show a decrease of NO2 tropospheric columns since 2013 and attributed to the NOx emissions reduction. The question of the impact of such reduction on ozone is then arising. In this study, we use the capabilities of the IASI satellite instrument to retrieve 2 semi-independent columns of ozone in the lower (surface-6km asl) and the upper (6-12km) troposphere - the lower tropospheric (LT) column having a sensitivity maximum at 3-4 km - and we evaluate the variability and trend of LT ozone over the NCP for 2008-2016. Deseasonalized monthly timeseries show two distinct periods: a first period (2008-2012) with no significant trend (slope of the linear fit < -0.1 %/yr) and a second period (2013-2016) with a highly significant negative trend of -1.2 %/yr, leading to an overall trend of -0.77 %/yr for 2008-2016. A first temptation is to attribute this decrease to the NOx emissions changes. However, negative trends have not been reported from background surface measurements in this Chinese region. Furthermore recent work made within the framework of the TOAR initiative reveals discrepancies in the sign of the trends of tropospheric column ozone derived from infrared and ultraviolet satellite instruments. As yet there is no conclusive explanation for the discrepancy. We then investigate the IASI retrieval stability and robustness in terms of vertical sensitivity, interferences with large aerosol loading, and comparing with surface and ozonesonde measurements and the IASI instrument aboard the Metop-B satellite. One issue arises concerning the temporal sampling of IASI that may induce significant change in the trend derived from surface stations. We also explore the possible variables, other than emissions, which could explain the observed negative trends using both a statistical regression model and simulations from global and regional chemistry transport models.
Sea-Level Trend Uncertainty With Pacific Climatic Variability and Temporally-Correlated Noise
NASA Astrophysics Data System (ADS)
Royston, Sam; Watson, Christopher S.; Legrésy, Benoît; King, Matt A.; Church, John A.; Bos, Machiel S.
2018-03-01
Recent studies have identified climatic drivers of the east-west see-saw of Pacific Ocean satellite altimetry era sea level trends and a number of sea-level trend and acceleration assessments attempt to account for this. We investigate the effect of Pacific climate variability, together with temporally-correlated noise, on linear trend error estimates and determine new time-of-emergence (ToE) estimates across the Indian and Pacific Oceans. Sea-level trend studies often advocate the use of auto-regressive (AR) noise models to adequately assess formal uncertainties, yet sea level often exhibits colored but non-AR(1) noise. Standard error estimates are over- or under-estimated by an AR(1) model for much of the Indo-Pacific sea level. Allowing for PDO and ENSO variability in the trend estimate only reduces standard errors across the tropics and we find noise characteristics are largely unaffected. Of importance for trend and acceleration detection studies, formal error estimates remain on average up to 1.6 times those from an AR(1) model for long-duration tide gauge data. There is an even chance that the observed trend from the satellite altimetry era exceeds the noise in patches of the tropical Pacific and Indian Oceans and the south-west and north-east Pacific gyres. By including climate indices in the trend analysis, the time it takes for the observed linear sea-level trend to emerge from the noise reduces by up to 2 decades.
Shindul-Rothschild, Judith; Gregas, Matt
2013-01-01
The Affordable Care Act is modeled after Massachusetts insurance reforms enacted in 2006. A linear mixed effect model examined trends in patient turnover and nurse employment in Massachusetts, New York, and California nonfederal hospitals from 2000 to 2011. The linear mixed effect analysis found that the rate of increase in hospital admissions was significantly higher in Massachusetts hospitals (p<.001) than that in California and New York (p=.007). The rate of change in registered nurses full-time equivalent hours per patient day was significantly less (p=.02) in Massachusetts than that in California and was not different from zero. The rate of change in admissions to registered nurses full-time equivalent hours per patient day was significantly greater in Massachusetts than California (p=.001) and New York (p<.01). Nurse staffing remained flat in Massachusetts, despite a significant increase in hospital admissions. The implications of the findings for nurse employment and hospital utilization following the implementation of national health insurance reform are discussed.
Trend and recovery of the total ozone column in South America and Antarctica
NASA Astrophysics Data System (ADS)
Toro A., Richard; Araya, Consuelo; Labra O., Felipe; Morales, Luis; Morales, Raúl G. E.; Leiva G., Manuel A.
2017-12-01
South America is one of the most vulnerable areas to stratospheric ozone depletion; consequently, an increased amount of UV radiation reaches the Earth's surface in this region. In this study, we analyzed the long-term trend in the total ozone column (TOC) over the southern part of the South American continent from 1980 to 2009. The database used was obtained by combining several satellite measurements of the TOC on a 1° (latitude) × 1.25° (longitude) grid. Analysis of the long-term trend was performed by applying the Theil-Sen estimator and the Mann-Kendall significance test to the deseasonalized time series. The long-term trend was also analyzed over several highly populated urban zones in the study area. Finally, multiple linear regression (MLR) modeling was used to identify and quantify the drivers of interannual variability in the TOC over the study area with a pixel-by-pixel approach. The results showed a decrease in the TOC ranging from -0.3 to -4% dec-1 from 1980 to 2009. On a decadal timescale, there is significant variability in this trend, and a decrease of more than -10% dec-1 was found at high latitudes (1980-1989). However, the trends obtained over much of the study area were not statistically significant. Considering the period from 1980 to 1995, we found a decrease in the TOC of -2.0 ± 0.6% dec-1 at latitudes below 40° S and -6.9 ± 2.0% dec-1 at latitudes above 40° S, for a 99.9% confidence level over most of the study area. Analysis of the period from 1996 to 2009 showed a statistically significant increase of 2.3 ± 0.1% dec-1 at high latitudes (> 60° S), confirming the initial TOC recovery in the Antarctic. Despite evidence for initial recovery of the TOC in some parts of the study area between 1996 and 2009, the long-term increase from September to November is not yet statistically significant. In addition, large parts of the study area and most of the urban areas continue to show a decreasing trend in the TOC. The MLR results show that at high latitudes, the main driver of interannual variability in the TOC is the total effective amount of halogens, followed by the eddy heat flux.
Schut, Antonius G T; Ivits, Eva; Conijn, Jacob G; Ten Brink, Ben; Fensholt, Rasmus
2015-01-01
Detailed understanding of a possible decoupling between climatic drivers of plant productivity and the response of ecosystems vegetation is required. We compared trends in six NDVI metrics (1982-2010) derived from the GIMMS3g dataset with modelled biomass productivity and assessed uncertainty in trend estimates. Annual total biomass weight (TBW) was calculated with the LINPAC model. Trends were determined using a simple linear regression, a Thiel-Sen medium slope and a piecewise regression (PWR) with two segments. Values of NDVI metrics were related to Net Primary Production (MODIS-NPP) and TBW per biome and land-use type. The simple linear and Thiel-Sen trends did not differ much whereas PWR increased the fraction of explained variation, depending on the NDVI metric considered. A positive trend in TBW indicating more favorable climatic conditions was found for 24% of pixels on land, and for 5% a negative trend. A decoupled trend, indicating positive TBW trends and monotonic negative or segmented and negative NDVI trends, was observed for 17-36% of all productive areas depending on the NDVI metric used. For only 1-2% of all pixels in productive areas, a diverging and greening trend was found despite a strong negative trend in TBW. The choice of NDVI metric used strongly affected outcomes on regional scales and differences in the fraction of explained variation in MODIS-NPP between biomes were large, and a combination of NDVI metrics is recommended for global studies. We have found an increasing difference between trends in climatic drivers and observed NDVI for large parts of the globe. Our findings suggest that future scenarios must consider impacts of constraints on plant growth such as extremes in weather and nutrient availability to predict changes in NPP and CO2 sequestration capacity.
Gardiner, Stuart K; Demirel, Shaban; De Moraes, Carlos Gustavo; Liebmann, Jeffrey M; Cioffi, George A; Ritch, Robert; Gordon, Mae O; Kass, Michael A
2013-02-15
Trend analysis techniques to detect glaucomatous progression typically assume a constant rate of change. This study uses data from the Ocular Hypertension Treatment Study to assess whether this assumption decreases sensitivity to changes in progression rate, by including earlier periods of stability. Series of visual fields (mean 24 per eye) completed at 6-month intervals from participants randomized initially to observation were split into subseries before and after the initiation of treatment (the "split-point"). The mean deviation rate of change (MDR) was derived using these entire subseries, and using only the window length (W) tests nearest the split-point, for different window lengths of W tests. A generalized estimating equation model was used to detect changes in MDR occurring at the split-point. Using shortened subseries with W = 7 tests, the MDR slowed by 0.142 dB/y upon initiation of treatment (P < 0.001), and the proportion of eyes showing "rapid deterioration" (MDR <-0.5 dB/y with P < 5%) decreased from 11.8% to 6.5% (P < 0.001). Using the entire sequence, no significant change in MDR was detected (P = 0.796), and there was no change in the proportion of eyes progressing (P = 0.084). Window lengths 6 ≤ W ≤ 9 produced similar benefits. Event analysis revealed a beneficial treatment effect in this dataset. This effect was not detected by linear trend analysis applied to entire series, but was detected when using shorter subseries of length between six and nine fields. Using linear trend analysis on the entire field sequence may not be optimal for detecting and monitoring progression. Nonlinear analyses may be needed for long series of fields. (ClinicalTrials.gov number, NCT00000125.).
NASA Astrophysics Data System (ADS)
Cook, Kerry H.; Vizy, Edward K.; Sun, Xiaoming
2018-03-01
Distributions of ocean mixed layer temperature trends and trends in the net heat flux from the atmosphere differ, indicating the important role of the transport of heat within the ocean for determining temperature trends. Annual-mean, linear trends in the components of the tropical ocean mixed layer heat budget for 1980-2015 are diagnosed in 4 ocean reanalyses to improve our physical understanding of multidecadal-scale SST trends. The well-known temperature trend in the tropical Pacific, with cooling in the east and warming in the west, is reproduced in each reanalysis with high statistical significance. Cooling in the east is associated with negative trends in the net heat flux from the atmosphere and enhanced equatorial upwelling related to a strengthening of the subtropical cells. Negative trends in the net heat flux also occur in the western tropical Pacific, but advective warming associated with a strengthening and shoaling of the equatorial undercurrent overwhelms these negative trends. The strengthening of the equatorial undercurrent is consistent with enhanced easterly wind stress, which is applied to the ocean reanalyses, and differential sea level trends that enhance the negative zonal height gradient across the Pacific. The Pacific North Equatorial countercurrent is also strengthening in all 4 reanalyses in association with a strengthening of the sea level trough at 10°N in the central and eastern Pacific. All 4 ocean reanalyses produce warming of 0.1-0.3 K/decade in the North Atlantic with statistical significance levels ranging from below 90-99%. The Atlantic is similar to the Pacific in having the equatorial undercurrent strengthening, but indications of shoaling are less consistent in the reanalyses and the North Equatorial Countercurrent in the Atlantic is not strengthening. Large-scale ocean mixed layer warming trends in the Indian Ocean in the reanalyses are interrupted by some regional cooling close to the equator. Net surface heat flux trends are mostly negative, indicating increasing heat fluxes from the ocean to the atmosphere. Wind stress trends applied to the ocean reanalyses are weak, but trends in the Indian Ocean equatorial undercurrent are strong. Since the Indian monsoon climate introduces strong seasonality, the annual analysis may not be adequate for studying physical processes in this ocean basin.
Methodological uncertainties in multi-regression analyses of middle-atmospheric data series.
Kerzenmacher, Tobias E; Keckhut, Philippe; Hauchecorne, Alain; Chanin, Marie-Lise
2006-07-01
Multi-regression analyses have often been used recently to detect trends, in particular in ozone or temperature data sets in the stratosphere. The confidence in detecting trends depends on a number of factors which generate uncertainties. Part of these uncertainties comes from the random variability and these are what is usually considered. They can be statistically estimated from residual deviations between the data and the fitting model. However, interferences between different sources of variability affecting the data set, such as the Quasi-Biennal Oscillation (QBO), volcanic aerosols, solar flux variability and the trend can also be a critical source of errors. This type of error has hitherto not been well quantified. In this work an artificial data series has been generated to carry out such estimates. The sources of errors considered here are: the length of the data series, the dependence on the choice of parameters used in the fitting model and the time evolution of the trend in the data series. Curves provided here, will permit future studies to test the magnitude of the methodological bias expected for a given case, as shown in several real examples. It is found that, if the data series is shorter than a decade, the uncertainties are very large, whatever factors are chosen to identify the source of the variability. However the errors can be limited when dealing with natural variability, if a sufficient number of periods (for periodic forcings) are covered by the analysed dataset. However when analysing the trend, the response to volcanic eruption induces a bias, whatever the length of the data series. The signal to noise ratio is a key factor: doubling the noise increases the period for which data is required in order to obtain an error smaller than 10%, from 1 to 3-4 decades. Moreover, if non-linear trends are superimposed on the data, and if the length of the series is longer than five years, a non-linear function has to be used to estimate trends. When applied to real data series, and when a breakpoint in the series occurs, the study reveals that data extending over 5 years are needed to detect a significant change in the slope of the ozone trends at mid-latitudes.
Attribution of trends in global vegetation greenness from 1982 to 2011
NASA Astrophysics Data System (ADS)
Zhu, Z.; Xu, L.; Bi, J.; Myneni, R.; Knyazikhin, Y.
2012-12-01
Time series of remotely sensed vegetation indices data provide evidence of changes in terrestrial vegetation activity over the past decades in the world. However, it is difficult to attribute cause-and-effect to vegetation trends because variations in vegetation productivity are driven by various factors. This study investigated changes in global vegetation productivity first, and then attributed the global natural vegetation with greening trend. Growing season integrated normalized difference vegetation index (GSI NDVI) derived from the new GIMMS NDVI3g dataset (1982-2011was analyzed. A combined time series analysis model, which was developed from simper linear trend model (SLT), autoregressive integrated moving average model (ARIMA) and Vogelsang's t-PST model shows that productivity of all vegetation types except deciduous broadleaf forest predominantly showed increasing trends through the 30-year period. The evolution of changes in productivity in the last decade was also investigated. Area of greening vegetation monotonically increased through the last decade, and both the browning and no change area monotonically decreased. To attribute the predominant increase trend of productivity of global natural vegetation, trends of eight climate time series datasets (three temperature, three precipitation and two radiation datasets) were analyzed. The attribution of trends in global vegetation greenness was summarized as relaxation of climatic constraints, fertilization and other unknown reasons. Result shows that nearly all the productivity increase of global natural vegetation was driven by relaxation of climatic constraints and fertilization, which play equally important role in driving global vegetation greenness.; Area fraction and productivity change fraction of IGBP vegetation land cover classes showing statistically significant (10% level) trend in GSI NDVIt;
Moshtaghian, H; Louie, J C Y; Charlton, K E; Probst, Y C; Gopinath, B; Mitchell, P; Flood, V M
2017-06-01
The trend of added sugar (AS) intake has not been investigated in the Australian population, including in older adults. The present study aimed to assess trends and food sources of AS intake among a cohort of older Australians during 15 years of follow-up. Dietary data from participants of the Blue Mountains Eye Study (1264 men and 1614 women), aged ≥49 years at baseline, were collected. Dietary intakes were assessed at 5-yearly intervals (1992-94 to 2007-09) using a 145-item food frequency questionnaire (FFQ). AS content of FFQ food items was estimated using a stepwise systematic method. Trends for AS intake between baseline and the three follow-up periods were assessed using linear mixed modelling. In men, the mean (SEM) percentage of energy provided by AS intake (EAS%) declined from 10.4% (0.1%) at baseline to 9.4% (0.2%) at 15-year follow-up (P trend = 0.028). Women's mean (SEM) EAS% intake at baseline and 15-year follow-up was 9.2% (0.1%) and 8.8% (0.2%), respectively (P trend = 0.550). EAS% intake of men was significantly higher than that of women for 10 years (P < 0.05). Sugar products (table sugar, syrup, jam and honey) were the major sources of AS at all-time points and contributed to more than 40% and 35% of AS intake in men and women, respectively. Intake of sugar products decreased in men during follow-up (P trend < 0.001). An overall downward trend was observed in AS intake in both genders, however, was only significant for men during 15 years of follow-up. Table sugar and sugar-containing spreads represent the major source of AS in this cohort of older Australians. © 2016 The British Dietetic Association Ltd.
Decrease in tropospheric O3 levels in the Northern Hemisphere observed by IASI
NASA Astrophysics Data System (ADS)
Wespes, Catherine; Hurtmans, Daniel; Clerbaux, Cathy; Boynard, Anne; Coheur, Pierre-François
2018-05-01
In this study, we describe the recent changes in the tropospheric ozone (O3) columns measured by the Infrared Atmospheric Sounding Interferometer (IASI), onboard the Metop satellite, during the first 9 years of operation (January 2008 to May 2017). Using appropriate multivariate regression methods, we differentiate significant linear trends from other sources of O3 variations captured by IASI. The geographical patterns of the adjusted O3 trends are provided and discussed on the global scale. Given the large contribution of the natural variability in comparison with that of the trend (25-85 % vs. 15-50 %, respectively) to the total O3 variations, we estimate that additional years of IASI measurements are generally required to detect the estimated O3 trends with high precision. Globally, additional 6 months to 6 years of measurements, depending on the regions and the seasons, are needed to detect a trend of |5| DU decade-1. An exception is interestingly found during summer at mid- and high latitudes of the Northern Hemisphere (NH; ˜ 40 to ˜ 75° N), where the large absolute fitted trend values (˜ |0.5| DU yr-1 on average) combined with the small model residuals (˜ 10 %) allow for detection of a band-like pattern of significant negative trends. Despite no consensus in terms of tropospheric O3 trends having been reached from the available independent datasets (UV or IR satellites, O3 sondes, aircrafts, ground-based measurements, etc.) for the reasons that are discussed in the text, this finding is consistent with the reported decrease in O3 precursor emissions in recent years, especially in Europe and USA. The influence of continental pollution on that latitudinal band is further investigated and supported by the analysis of the O3-CO relationship (in terms of correlation coefficient, regression slope and covariance) that we found to be the strongest at northern midlatitudes in summer.
Trends in popularity of some morphological traits of purebred dogs in Australia.
Teng, Kendy T; McGreevy, Paul D; Toribio, Jenny-Ann L M L; Dhand, Navneet K
2016-01-01
The morphology of dogs can provide information about their predisposition to some disorders. For example, larger breeds are predisposed to hip dysplasia and many neoplastic diseases. Therefore, longitudinal trends in popularity of dog morphology can reveal potential disease pervasiveness in the future. There have been reports on the popularity of particular breeds and behavioural traits but trends in the morphological traits of preferred breeds have not been studied. This study investigated trends in the height, dog size and head shape (cephalic index) of Australian purebred dogs. One hundred eighty-one breeds derived from Australian National Kennel Council (ANKC) registration statistics from 1986 to 2013 were analysed. Weighted regression analyses were conducted to examine trends in the traits by using them as outcome variables, with year as the explanatory variable and numbers of registered dogs as weights. Linear regression investigated dog height and cephalic index (skull width/skull length), and multinomial logistic regression studied dog size. The total number of ANKC registration had decreased gradually from 95,792 in 1986 to 66,902 in 2013. Both weighted minimal height (p = 0.014) and weighted maximal height (p < 0.001) decreased significantly over time, and the weighted cephalic index increased significantly (p < 0.001). The odds of registration of medium and small breeds increased by 5.3 % and 4.2 %, respectively, relative to large breeds (p < 0.001) and by 12.1 % and 11.0 %, respectively, relative to giant breeds (p < 0.001) for each 5-year block of time. Compared to taller and larger breeds, shorter and smaller breeds have become relatively popular over time. Mean cephalic index has increased, which indicates that Australians have gradually favoured breeds with shorter and wider heads (brachycephalic). These significant trends indicate that the dog morphological traits reported here may potentially influence how people select companion dogs in Australia and provide valuable predictive information on the pervasiveness of diseases in dogs.
Growth patterns and cerebro-placental hemodynamics in fetuses with congenital heart disease.
Mebius, M J; Clur, S A B; Vink, A S; Pajkrt, E; Kalteren, W S; Kooi, E M W; Bos, A F; du Marchie Sarvaas, G J; Bilardo, C M
2018-05-28
Congenital heart disease (CHD) has been associated with a reduced fetal head circumference (HC). The underlying pathophysiological background remains undetermined. We aimed to define trends in fetal growth and cerebro-placental Doppler flow, and to investigate the association between head growth and cerebro-placental flow in fetuses with CHD. Fetuses with CHD and serial measurements of HC, abdominal circumference (AC), middle cerebral artery pulsatility index (MCA-PI), umbilical artery pulsatility index (UA-PI), and cerebro-placental ratio (CPR) were included. CHD was categorized into 3 groups based on expected cerebral arterial oxygen saturation: normal, mild to moderately reduced, and severely reduced. Trends over time in Z-scores were analyzed using a linear mixed-effects model. 181 fetuses fulfilled the inclusion criteria. Expected cerebral arterial oxygen saturation in CHD was classified as normal in 44, mild to moderately reduced in 84 and severely reduced in 53 cases. HC z-scores showed a tendency to decrease until 23 weeks, then to increase until 33 weeks, followed by a decrease again in the late third trimester. AC increased progressively with advancing gestation. MCA-PI and UA-PI showed significant trends throughout pregnancy, but CPR did not. There were no associations between expected cerebral arterial oxygen saturation and fetal growth. Average trends in MCA-PI were significantly different in the three subgroups (P=0.010), whereas average trends in UA-PI and CPR were similar (P=0.530 and P=0.285). Furthermore, there was no significant association between MCA-PI and HC (P=0.284). Fetal biometry and Doppler flow patterns are within normal ranges in fetuses with CHD, but show trends over time. Fetal head growth is not associated with the cerebral blood flow pattern or placental function and HC is not influenced by the cerebral arterial oxygen saturation. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
NASA Astrophysics Data System (ADS)
Bayer Altın, Türkan; Barak, Belma
2017-11-01
In this study, the long-term variability and trends of the annual and seasonal numbers of summer and tropical days of the Adana Sub-region were investigated using nonlinear and linear trend detection tests for the period 1960-2014 at 14 meteorological stations. The results suggest that the annual number of summer and tropical days was generally below the long-term average through to the end of the 1980s. In particular, positive anomaly values could be observed at all stations between the years 1993-2014. With respect to the Kruskal-Wallis homogeneity test, the significant breaking date was 1993. The rapid rise of the annual number of summer (tropical) days after this year led to the inversion of the negative trends observed from 1987 to 1992 into positive ones. The increasing trend is statistically significance at 0.01 level in Yumurtalık, Mersin and Antakya for the annual number of summer and tropical days. Dörtyol, İskenderun and Elbistan were significance at 0.01 level for tropical days. The largest positive anomalies of the summer of 2010 are observed in coastal vicinity (Mersin, Yumurtalık and İskenderun). This indicates that these settlements underwent a long-term warm period and thermal conditions due to increasing temperatures in the spring and summer months. The same conditions are found in high inner areas (Göksun and Elbistan) for tropical days. It is noticed that a tendency for greater warming occurred at stations located above 1000 m in the sub-region. The average number of warm days will increase 2-days per 100-years in southern part of the sub-region. The increasing trend in summer temperatures can be considered a potential risk, notably for human health and for economic and crop losses in the Adana Sub-region, including Çukurova, one of the most important agriculture areas of Turkey.
Burnett, Aaron; Kurtz, Andrew C; Brabander, Daniel; Shailer, Mark
2007-01-01
Laser-ablation inductively coupled-plasma mass-spectrometry analysis of red oak (Quercus rubra) from a well documented heavy metal contaminated United States Environmental Protection Agency superfund site in Woburn, Massachusetts reveals decade-long trends in Pb contaminant sources. Lead isotope ratios (207Pb/206Pb and 208Pb/206Pb) in tree rings plot along a linear trend bracketed by several local and regional contamination sources. Statistically significant interannual variations in 207Pb/206Pb suggest that atmospheric Pb is rapidly incorporated into wood, with minimal mobility subsequent to deposition in annual growth rings. We interpret the decadal trends in our record as a changing mixture of local pollution sources and gasoline-derived Pb. Between 1940 and 1970, Pb was predominantly derived from remobilization of local industrial Pb sources. An abrupt shift in 207Pb/206Pb may indicate that local Pb sources were overwhelmed by gasoline-derived Pb during the peak of leaded gasoline emissions in the late 1960s and early 1970s.
Per capita alcohol consumption in Australia: will the real trend please step forward?
Chikritzhs, Tanya N; Allsop, Steve J; Moodie, A Rob; Hall, Wayne D
2010-11-15
To estimate the national trend in per capita consumption (PCC) of alcohol for Australians aged 15 years and older for the financial years 1990-91 to 2008-09. With the use of data obtained from Australian Bureau of Statistics' catalogues and World Advertising Research Centre reports, three alternative series of annual totals of PCC of alcohol for the past 20 years (1990-91 to 2008-09) were estimated based on different assumptions about the alcohol content of wine. For the "old" series, the alcohol content of wine was assumed to have been stable over time. For the "new" series, the alcohol content of wine was assumed to have increased once in 2004-05 and then to have remained stable to 2008-09. For the "adjusted" series, the alcohol content of wine was assumed to have gradually increased over time, beginning in 1998-99. Linear trend analysis was applied to identify significant trends. National trend in annual PCC of alcohol 1990-91 to 2008-09. The new and adjusted series of annual totals of PCC of alcohol showed increasing trends; the old series was stable. Until recently, official national annual totals of PCC of alcohol were underestimated and led to the mistaken impression that levels of alcohol consumption had been stable since the early 1990s. In fact, Australia's total PCC has been increasing significantly over time because of a gradual increase in the alcohol content and market share of wine and is now at one of its highest points since 1991-92. This new information is consistent with evidence of increasing alcohol-related harm and highlights the need for timely and accurate data on alcohol sales and harms across Australia.
2010-01-01
Background Giving the rising trend in childhood obesity in many countries including Switzerland, strategies to increase physical activity such as promoting active school travel are important. Yet, little is known about time trends of active commuting in Swiss schoolchildren and factors associated with changes in walking and biking to school. Methods Between 1994 and 2005, information about mobility behaviour of children aged 6-14 years was collected within three Swiss population based national travel behaviour surveys. Mode of transport to school was reported for 4244 children. Weighted multivariate logistic regression analyses were used to assess active school travel time trends and their influencing factors. Results More than 70% of Swiss children walked or biked to school. Nevertheless, the proportion of children biking to school decreased (p = 0.05, linear trend), predominately in urban areas, and motorized transportation increased since 1994 (p = 0.02). Distance to school did not change significantly over time but availability of bikes decreased (p < 0.001) and number of cars per household increased (p < 0.001). The association between survey year and bike use was significantly modified by living in an urban area (OR (95%CI): 1.0, 0.63 (0.44-0.90), 0.71 (0.49-1.03), respectively for 1994, 2000 and 2005) and by distance to school (OR (95%CI): 1.0, 0.65 (0.40-1.05), 0.50 (0.23-0.79) for the same years and for children who lived more than a mile away from school). Conclusions Programs to encourage safe biking and to limit car use as mode of transport to school are warranted to stop this trend. PMID:20398320
Beulens, J W J; Algra, A; Soedamah-Muthu, S S; Visseren, F L J; Grobbee, D E; van der Graaf, Y
2010-09-01
This study investigated the relation between alcohol consumption and specific vascular events and mortality in a high risk population of patients with clinical manifestations of vascular disease and diabetes. Patients with clinically manifest vascular disease or diabetes (n=5447) from the SMART study were followed for cardiovascular events and mortality. Alcohol consumption was assessed with a baseline questionnaire and analysed in relation with coronary heart disease (CHD), amputations, stroke, and all-cause and vascular death. After a follow up of 4.7 years, we documented 363 cases of CHD, 187 cases of stroke, 79 amputations and 641 cases of all-cause death, of which 382 were vascular. In multivariate-adjusted models, alcohol consumption was inversely associated with CHD (p(linear trend)=0.007) and stroke (p(linear trend)=0.051) with respective hazard ratios of 0.39 (95%CI: 0.20-0.76) and 0.67 (0.31-1.46) for consuming 10-20 drinks/week compared with abstainers. We observed significant U-shaped associations between alcohol consumption and amputations (p(quadratic trend)=0.001), all-cause death (p(quadratic trend)=0.001) and vascular death (p(quadratic trend)=0.013). Hazard ratios for consuming 10-20 drinks/week were 0.29 (0.07-1.30) for amputations, 0.40 (0.24-0.69) for all-cause death and 0.34 (0.16-0.71) for vascular death compared with abstainers. Similar associations were observed for red wine consumption only. Moderate alcohol consumption (1-2 drinks/day) is not only associated with a reduced risk of vascular and all-cause death in a high risk patients with clinical manifestations of vascular disease, but also with reduced risks of non-fatal events like CHD, stroke and possibly amputations. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Eshleman, K. N.
2011-12-01
Water quality monitoring data from streams and rivers provide the "gold standard" by which progress toward achieving real reductions in nutrient loadings to Chesapeake Bay must ultimately be assessed. The most recent trend results posted at the Chesapeake Bay Program (CBP) website reveal that a substantial percentage of tributaries are now showing long-term declines in flow-adjusted concentrations of nutrients and sediments: 22 sites showed statistically significant (p < 0.05) downward trends (1985-2010) in flow-adjusted concentrations, two sites showed upward trends, and eight sites showed no trend. Based on the data, the CBP has drawn the following conclusion: "At many monitored locations, long-term trends indicate that management actions, such as pollution controls for improved wastewater treatment plants and practices to reduce nutrients on farms and suburban lands, have reduced concentrations of nitrogen." But could this conclusion be pre-mature? I recently undertook a comparable analysis of long-term nitrate-N trends for a different group of watersheds (all located in the Chesapeake Bay watershed with long data records); this group includes nine watersheds that are predominantly (i.e., >75%) forested, plus five other Potomac River subwatersheds added for comparison. Based on comparable data and analytical methods to those used by CBP partners and USGS, 13 of the 14 sites-including both Potomac River stations (Chain Bridge at Washington DC and Hancock, Maryland)-showed statistically significant decreasing linear trends in annual flow-weighted nitrate-N concentration. Only one station-the heavily agricultural Upper Monocacy River-did not show a statistically significant (p < 0.05) trend. Five of the predominantly-forested watersheds also showed statistically significant decreasing trends in annual nitrate-N loads, and none of the stations showed a trend in annual runoff presumably due to high inter-annual hydroclimatological variability. While the largest absolute changes in nitrate-N concentration corresponded to the least forested watersheds, the largest percentage changes in nitrate-N concentration were actually observed for those watersheds with the greatest percentages of forestland. This result suggests that the natural dynamics of forests may be playing a very important (and under-appreciated) role in improving water quality throughout the Bay watershed. A second interesting finding was that the statistically significant reductions in annual nitrate-N concentration at the Potomac River RIM station could be entirely explained by commensurate improvements at the upstream (Hancock) station; in fact, no trend in nitrate-N concentration associated with the eastern portion of the basin was found (after subtracting out the influence of the upstream portion). Additional research is needed to understand why nitrogen retention by forested lands may be increasing and thus helping restore water quality throughout the Chesapeake Bay watershed. The results also have obvious implications for meeting local water quality goals as well as the basin-wide goal of the Chesapeake Bay TMDL for nitrogen.
NASA Astrophysics Data System (ADS)
Cook, K. H.; Vizy, E. K.; Sun, X.
2016-12-01
Multiple atmospheric and ocean reanalyses are analyzed for 1980-2015 to understand annual-mean adjustments of the surface heat balance over the tropical oceans as the climate warms. Linear trends are examined, with statistical significance evaluated. While surface heat budgets and sea surface temperatures are mutually adjusted fields, insights into the physical processes of this adjustment and the implications for temperature trends can be identified. Two second-generation reanalyses, ERA-Interim and JRA-55, agree well on the distributions and magnitudes of trends in the net heat flux from the atmosphere to the ocean. Trends in the net longwave and sensible heat fluxes are generally small, and trends in solar radiation absorbed are only influential regionally and vary among the reanalyses. The largest contribution is from latent heat flux trends. Contributions to these trends associated with surface temperature (thermal-driving), 10-m wind (dynamical-driving) and specific humidity (hydrological-driving) trends are estimated. The dynamically-driven latent heat flux dominates and explains much of the regionality of the multi-decadal heat flux trends. However, trends in the net surface heat flux alone do not match the observed SSTs trends well, indicating that the redistribution of heat within the ocean mixed layer is also important. Ocean mixed layer heat budgets in various ocean reanalyses are examined to understand this redistribution, and we again identify a crucial role for changes in the surface wind. Acceleration of the tropical easterlies is associated with strengthening of the equatorial undercurrents in both the tropical Pacific and Atlantic. In the Pacific, where the EUC is also shoaling, the result is enhanced warm-water advection into the central Pacific. This advective warming is superimposed on cooling due to enhanced evaporation and equatorial upwelling, which are also associated with wind trends, to determine the observed pattern of SST trends.
2012-01-01
Background The Taiwan government adopted National Health Insurance (NHI) in 1995, providing universal health care to all citizens. It was financed by mandatory premium contributions made by employers, employees, and the government. Since then, the government has faced increasing challenges to control NHI expenditures. The aim of this study was to determine trends in the provision of dental services in Taiwan after the implementation of global budgeting in 1998 and to identify areas of possible concern. Methods This longitudinal before/after study was based on data from the National Health Insurance Research Database from 1996 to 2001. These data were subjected to logistic regression analysis. Linear regression analysis was used to examine changes in delivery of specific services after global budgeting implementation. Utilization of hospital and clinic services was compared. Results Reimbursement for dental services increased significantly while the number of visits per patient remained steady in both hospitals and clinics. In hospitals, visits for root canal procedures, ionomer restoration, tooth extraction and tooth scaling increased significantly. In dental clinics, visits for amalgam restoration decreased significantly while those for ionomer restoration, tooth extraction, and tooth scaling increased significantly. After the adoption of global budgeting, expenditures for dental services increased dramatically while the number of visits per patient did not, indicating a possible shift in patients to hospital facilities that received additional National Health Insurance funding. Conclusions The identified trends indicate increased utilization of dental services and uneven distribution of care and dentists. These trends may be compromising the quality of dental care delivered in Taiwan. PMID:23009095
Dhillon, P K; Yeole, B B; Dikshit, R; Kurkure, A P; Bray, F
2011-01-01
Background: Demographic, socioeconomic and cultural changes in India have increased longevity, delayed childbearing, decreased parity and resulted in a more westernised lifestyle, contributing to the increasing burden of cancer, especially among women. Methods: We evaluated secular changes in the incidence of breast, cervical and ovarian cancer in Mumbai women aged 30–64 between 1976 and 2005. Age-standardised incidence rates were calculated and presented by site and calendar period. An age–period–cohort (APC) analysis quantified recent time trends and the significance of birth cohort and calendar period effects. The estimated annual percent change (EAPC) was obtained from the drift parameter, expressing the linear time trend common to both calendar period and birth cohort. Results: Over the 30-year study period, the age-standardised rates significantly increased for breast cancer (EAPC: 1.1% (95% confidence interval (CI): 1.0, 1.3)), significantly decreased for cervical cancer (EAPC: −1.8% (95% CI: −2.0, −1.6)) and there was no statistically significant change for ovarian cancer (EAPC: 0.3% (95% CI: −0.1, 0.6)). For breast and cervical cancer, the best-fitting model was the APC model. Conclusions: The rates of breast, cervical and ovarian cancer remain low in comparison with western countries, and the divergent trends of breast (increasing) and cervical cancer (decreasing) in Mumbai were similar to those observed in several other Asian countries. The changing risk profile in successive generations – improved education, higher socioeconomic status, later age at marriage and at first child, and lower parity – may in combination partially explain the diverging generational changes in breast and cervical cancer in Mumbai in the last decades. PMID:21829198
NASA Astrophysics Data System (ADS)
Liu, Yi; Sheng, Zhuping
2011-11-01
SummaryAtmospheric water, surface water, and groundwater interact very actively through hydrologic processes such as precipitation, infiltration, seepage, irrigation, drainage, evaporation, and evapotranspiration in the Upper Rio Grande Basin. A trend-outflow method has been developed in this paper to gain a better understanding of the interactions based on cumulated inflow and outflow data for any river reaches of interest. A general trend-outflow equation was derived by associating the net interaction of surface water with atmospheric water as a polynomial of inflow and the net interaction of surface water with groundwater as a constant based on surface water budget. Linear and quadratic relations are probably two common trend-outflow types in the real world. It was found that trend-outflows of the Upper Rio Grande reaches, Española, Albuquerque, Socorro-Engle, Palomas, and Rincon are linear with inflow, while those of reaches, Belen, Mesilla and Hueco are quadratic. Reaches Belen, Mesilla and Hueco are found as water deficit reaches mainly for irrigated agriculture in extreme drought years.
NASA Astrophysics Data System (ADS)
Jaggi, Chandra K.; Khanna, Aditi; Verma, Priyanka
2011-07-01
In today's business transactions, there are various reasons, namely, bulk purchase discounts, re-ordering costs, seasonality of products, inflation induced demand, etc., which force the buyer to order more than the warehouse capacity. Such situations call for additional storage space to store the excess units purchased. This additional storage space is typically a rented warehouse. Inflation plays a very interesting and significant role here: It increases the cost of goods. To safeguard from the rising prices, during the inflation regime, the organisation prefers to keep a higher inventory, thereby increasing the aggregate demand. This additional inventory needs additional storage space, which is facilitated by a rented warehouse. Ignoring the effects of the time value of money and inflation might yield misleading results. In this study, a two-warehouse inventory model with linear trend in demand under inflationary conditions having different rates of deterioration has been developed. Shortages at the owned warehouse are also allowed subject to partial backlogging. The solution methodology provided in the model helps to decide on the feasibility of renting a warehouse. Finally, findings have been illustrated with the help of numerical examples. Comprehensive sensitivity analysis has also been provided.
Structural and lithologic study of Northern Coast Range and Sacramento Valley, California
NASA Technical Reports Server (NTRS)
Rich, E. I. (Principal Investigator)
1973-01-01
The author has identified the following significant results. Preliminary analysis of the data received has disclosed two potentially important northwest-trending systems of linear features within the Northern California Coast Ranges. A third system, which trends northeast, can be traced with great uncertainty across the alluviated part of the Sacramento Valley and into the foothills of the Sierra Nevada. These linear features may represent fault systems or zones of shearing. Of interest, although not yet verified, is the observation that some of the mercury concentrations and some of the geothermally active areas of California may be located at the intersection of the Central and the Valley Systems. One, perhaps two, stratigraphic unconformities within the Late Mesozoic sedimentary rocks were detected during preliminary examination of the imagery; however, more analysis is necessary in order to verify this preliminary interpretation. A heretofore unrecognized, large circular depression, about 15 km in diameter, was detected within the alluviated part of the Sacramento Valley. The depression is adjacent to a large laccolithic intrusion and may be geologically related to it. Changes in the photogeologic characteristics of this feature will continue to be monitored.
Lundström, Sebastian; Reichenberg, Abraham; Anckarsäter, Henrik; Lichtenstein, Paul; Gillberg, Christopher
2015-04-28
To compare the annual prevalence of the autism symptom phenotype and of registered diagnoses for autism spectrum disorder during a 10 year period in children. Population based study. Child and Adolescent Twin Study and national patient register, Sweden. 19, 993 twins (190 with autism spectrum disorder) and all children (n=1,078,975; 4620 with autism spectrum disorder) born in Sweden over a 10 year period from 1993 to 2002. Annual prevalence of the autism symptom phenotype (that is, symptoms on which the diagnostic criteria are based) assessed by a validated parental telephone interview (the Autism-Tics, ADHD and other Comorbidities inventory), and annual prevalence of reported diagnoses of autism spectrum disorder in the national patient register. The annual prevalence of the autism symptom phenotype was stable during the 10 year period (P=0.87 for linear time trend). In contrast, there was a monotonic significant increase in prevalence of registered diagnoses of autism spectrum disorder in the national patient register (P<0.001 for linear trend). The prevalence of the autism symptom phenotype has remained stable in children in Sweden while the official prevalence for registered, clinically diagnosed, autism spectrum disorder has increased substantially. This suggests that administrative changes, affecting the registered prevalence, rather than secular factors affecting the pathogenesis, are important for the increase in reported prevalence of autism spectrum disorder. © Lundström et al 2015.
Williams, Marshall L.; MacCoy, Dorene E.; Maret, Terry R.
2015-07-17
Coupled with the dynamic put-and-take fishery, the outcomes reflect the system complexities among reservoirs despite their fairly close proximity to one another. The influence of these other factors is evident when the analysis of atmospheric Hg deposition at Mercury Deposition Network site NV02 in northern Nevada showed no significant linear trend in wet Hg deposition rates for 2003–2013 (average 3.02 micrograms per square meter).
Baldwin, Carol M; Figueredo, Aurelio J; Wright, Lynda S; Wong, Simon S; Witten, Mark L
2007-07-01
Four groups of Fischer Brown Norway hybrid rats were exposed for 5, 10, 15, or 20 d to aerosolized-vapor jet propulsion fuel 8 (JP-8) compared to freely moving (5 and 10-d exposures) or sham-confined controls (15 and 20-d exposures). Behavioral testing utilized the U.S. Environmental Protection Agency Functional Observational Battery. Exploratory ethological factor analysis identified three salient factors (central nervous system [CNS] excitability, autonomic 1, and autonomic 2) for use in profiling JP-8 exposure in future studies. The factors were used as dependent variables in general linear modeling. Exposed animals were found to engage in more rearing and hyperaroused behavior compared to controls, replicating prior JP-8 exposure findings. Exposed animals also showed increasing but rapidly decelerating stool output (autonomic 1), and a significant increasing linear trend for urine output (autonomic 2). No significant trends were noted for either of the control groups for the autonomic factors. Rats from each of the groups for each of the time frames were randomly selected for tissue assay from seven brain regions for neurotransmitter levels. Hippocampal DOPAC was significantly elevated after 4-wk JP-8 exposure compared to both control groups, suggesting increased dopamine release and metabolism. Findings indicate that behavioral changes do not appear to manifest until wk 3 and 4 of exposure, suggesting the need for longitudinal studies to determine if these behaviors occur due to cumulative exposure, or due to behavioral sensitization related to repeated exposure to aerosolized-vapor JP-8.
Radiofrequency electromagnetic fields; male infertility and sex ratio of offspring.
Baste, Valborg; Riise, Trond; Moen, Bente E
2008-01-01
Concern is growing about exposure to electromagnetic fields and male reproductive health. The authors performed a cross-sectional study among military men employed in the Royal Norwegian Navy, including information about work close to equipment emitting radiofrequency electromagnetic fields, one-year infertility, children and sex of the offspring. Among 10,497 respondents, 22% had worked close to high-frequency aerials to a "high" or "very high" degree. Infertility increased significantly along with increasing self-reported exposure to radiofrequency electromagnetic fields. In a logistic regression, odds ratio (OR) for infertility among those who had worked closer than 10 m from high-frequency aerials to a "very high" degree relative to those who reported no work near high-frequency aerials was 1.86 (95% confidence interval (CI): 1.46-2.37), adjusted for age, smoking habits, alcohol consumption and exposure to organic solvents, welding and lead. Similar adjusted OR for those exposed to a "high", "some" and "low" degree were 1.93 (95% CI: 1.55-2.40), 1.52 (95% CI: 1.25-1.84), and 1.39 (95% CI: 1.15-1.68), respectively. In all age groups there were significant linear trends with higher prevalence of involuntary childlessness with higher self-reported exposure to radiofrequency fields. However, the degree of exposure to radiofrequency radiation and the number of children were not associated. For self-reported exposure both to high-frequency aerials and communication equipment there were significant linear trends with lower ratio of boys to girls at birth when the father reported a higher degree of radiofrequency electromagnetic exposure.
NASA Astrophysics Data System (ADS)
Monroe, Roberta Lynn
The intrinsic fundamental frequency effect among vowels is a vocalic phenomenon of adult speech in which high vowels have higher fundamental frequencies in relation to low vowels. Acoustic investigations of children's speech have shown that variability of the speech signal decreases as children's ages increase. Fundamental frequency measures have been suggested as an indirect metric for the development of laryngeal stability and coordination. Studies of the intrinsic fundamental frequency effect have been conducted among 8- and 9-year old children and in infants. The present study investigated this effect among 2- and 4-year old children. Eight 2-year old and eight 4-year old children produced four vowels, /ae/, /i/, /u/, and /a/, in CVC syllables. Three measures of fundamental frequency were taken. These were mean fundamental frequency, the intra-utterance standard deviation of the fundamental frequency, and the extent to which the cycle-to-cycle pattern of the fundamental frequency was predicted by a linear trend. An analysis of variance was performed to compare the two age groups, the four vowels, and the earlier and later repetitions of the CVC syllables. A significant difference between the two age groups was detected using the intra-utterance standard deviation of the fundamental frequency. Mean fundamental frequencies and linear trend analysis showed that voicing of the preceding consonant determined the statistical significance of the age-group comparisons. Statistically significant differences among the fundamental frequencies of the four vowels were not detected for either age group.
Exploring spatial patterns and drivers of forest fires in Portugal (1980-2014).
Nunes, A N; Lourenço, L; Meira, A C Castro
2016-12-15
Information on the spatial incidence of fire ignition density and burnt area, trends and drivers of wildfires is vitally important in providing support for environmental and civil protection policies, designing appropriate prevention measures and allocating firefighting resources. The key objectives of this study were to analyse the geographical incidence and temporal trends for wildfires, as well as the main drivers of fire ignition and burnt area in Portugal on a municipal level. The results show that fires are not distributed uniformly throughout Portuguese territory, both in terms of ignition density and burnt area. One spot in the north-western area is well defined, covering 10% of the municipalities where more than one third of the total fire ignitions are concentrated. In >80% of Portuguese municipalities, ignition density has registered a positive trend since the 1980s. With regard to burnt area, 60% of the municipalities had a nil annual trend, 35% showed a positive trend and 5%, located mainly in the central region, revealed negative trends. Geographically weighted regression proved more efficient in identifying the most relevant physical and anthropogenic drivers of municipal wildfires in comparison with simple linear regression models. Topography, density of population, land cover and livestock were found to be significant in both ignition density and burnt area, although considerable variations were observed in municipal explanatory power. Copyright © 2016 Elsevier B.V. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Burgess, Caitlin; Skalski, John R.
2001-05-01
Effects of oceanographic conditions, as well as effects of release-timing and release-size, on first ocean-year survival of subyearling fall chinook salmon were investigated by analyzing CWT release and recovery data from Oregon and Washington coastal hatcheries. Age-class strength was estimated using a multinomial probability likelihood which estimated first-year survival as a proportional hazards regression against ocean and release covariates. Weight-at-release and release-month were found to significantly effect first year survival (p < 0.05) and ocean effects were therefore estimated after adjusting for weight-at-release. Negative survival trend was modeled for sea surface temperature (SST) during 11 months of the year overmore » the study period (1970-1992). Statistically significant negative survival trends (p < 0.05) were found for SST during April, June, November and December. Strong pairwise correlations (r > 0.6) between SST in April/June, April/November and April/December suggest the significant relationships were due to one underlying process. At higher latitudes (45{sup o} and 48{sup o}N), summer upwelling (June-August) showed positive survival trend with survival and fall (September-November) downwelling showed positive trend with survival, indicating early fall transition improved survival. At 45{sup o} and 48{sup o}, during spring, alternating survival trends with upwelling were observed between March and May, with negative trend occurring in March and May, and positive trend with survival occurring in April. In January, two distinct scenarios of improved survival were linked to upwelling conditions, indicated by (1) a significant linear model effect (p < 0.05) showing improved survival with increasing upwelling, and (2) significant bowl-shaped curvature (p < 0.05) of survival with upwelling. The interpretation of the effects is that there was (1) significantly improved survival when downwelling conditions shifted to upwelling conditions in January (i.e., early spring transition occurred, p < 0.05), (2) improved survival during strong downwelling conditions (Bakun units < -250). Survival decreased during weak downwelling conditions (Bakun units between -180 and -100). Strong to moderately strong correlations between January upwelling and April SST (r = 0.5), June SST (r = 0.6), and the North Pacific Index (NPI) of Aleutian Low strength (r > 0.7) suggest January is a period when important effects originate and play out over ensuing months. Significant inverse trend with survival (p < 0.05) was found for Bakun indices in December, indicating strong downwelling improved survival. Higher-than-average adult return rates were observed for cohorts from brood-years 1982-1983, strong El Nino years. Individual hatcheries were found to have unique age-class strength and age-at-return characteristics.« less
Effect of Drug Sample Removal on Prescribing in a Family Practice Clinic
Hartung, Daniel M.; Evans, David; Haxby, Dean G.; Kraemer, Dale F.; Andeen, Gabriel; Fagnan, Lyle J.
2010-01-01
PURPOSE Little is known about the impact of recent restrictions on pharmaceutical industry detailing and sampling on prescribing behavior, particularly within smaller, independent practices. The objective of this study was to evaluate the effect of a policy prohibiting prescription drug samples and pharmaceutical industry interaction on prescribing patterns in a rural family practice clinic in central Oregon. METHODS Segmented linear regression models were used to evaluate trends in prescribing using locally obtained pharmacy claims. Oregon Medicaid pharmacy claims were used to control for secular prescribing changes. Total and class-specific monthly trends in branded, promoted, and average prescription drug costs were analyzed 18 months before and after policy implementation. RESULTS Aggregate trends of brand name drug use did not change significantly after policy implementation. In aggregate, use of promoted agents decreased by 1.43% while nonpromoted branded agents increased by 3.04%. Branded drugs prescribed for respiratory disease declined significantly by 11.34% compared with a control group of prescribers. Relative to the control group, prescriptions of promoted cholesterol-lowering drugs and antidepressants were reduced by approximately 9.98% and 11.34%, respectively. The trend in average cost per prescription for lipid-lowering drugs was significantly reduced by $0.70 per prescription per month. Overall, average prescription drug costs increased by $5.18 immediately after policy implementation. CONCLUSIONS Restriction of pharmaceutical industry representatives and samples from a rural family practice clinic produced modest reductions in branded drug use that varied by class. Although aggregate average costs increased, prescriptions for branded and promoted lipid-lowering agents and antidepressants were reduced. PMID:20843881
Effect of drug sample removal on prescribing in a family practice clinic.
Hartung, Daniel M; Evans, David; Haxby, Dean G; Kraemer, Dale F; Andeen, Gabriel; Fagnan, Lyle J
2010-01-01
Little is known about the impact of recent restrictions on pharmaceutical industry detailing and sampling on prescribing behavior, particularly within smaller, independent practices. The objective of this study was to evaluate the effect of a policy prohibiting prescription drug samples and pharmaceutical industry interaction on prescribing patterns in a rural family practice clinic in central Oregon. Segmented linear regression models were used to evaluate trends in prescribing using locally obtained pharmacy claims. Oregon Medicaid pharmacy claims were used to control for secular prescribing changes. Total and class-specific monthly trends in branded, promoted, and average prescription drug costs were analyzed 18 months before and after policy implementation. Aggregate trends of brand name drug use did not change significantly after policy implementation. In aggregate, use of promoted agents decreased by 1.43% while nonpromoted branded agents increased by 3.04%. Branded drugs prescribed for respiratory disease declined significantly by 11.34% compared with a control group of prescribers. Relative to the control group, prescriptions of promoted cholesterol-lowering drugs and antidepressants were reduced by approximately 9.98% and 11.34%, respectively. The trend in average cost per prescription for lipid-lowering drugs was significantly reduced by $0.70 per prescription per month. Overall, average prescription drug costs increased by $5.18 immediately after policy implementation. Restriction of pharmaceutical industry representatives and samples from a rural family practice clinic produced modest reductions in branded drug use that varied by class. Although aggregate average costs increased, prescriptions for branded and promoted lipid-lowering agents and antidepressants were reduced.
Trends in diabetes-related visits to US EDs from 1997 to 2007.
Menchine, Michael D; Wiechmann, Warren; Peters, Anne L; Arora, Sanjay
2012-06-01
The aims of the study were to describe temporal trends in the number, proportion, and per capita use of diabetes-related emergency department (ED) visits and to examine any racial/ethnic disparity in ED use for diabetes-related reasons. We analyzed the ED portion of the National Hospital Ambulatory Medical Care Survey from 1997 through 2007. Diabetes-related ED visits were identified by International Classification of Diseases, Ninth Revision codes. Descriptive statistics were developed. Weighted linear and logistic regression models were used to determine significance of temporal trends, and multivariate logistic regression was used to examine racial/ethnic disparities. A total of 20.2 million (1.69%; 95% confidence interval [CI], 1.59%-1.78%) ED visits were diabetes-related during the study period. We observed significant increases in the number and proportion of diabetes-related ED visits. Overall, there was a 5.6% relative annual increase in the proportion of ED visits that were diabetes-related during the study period. However, the per capita ED use among the population with diabetes did not change over time (P>.05 for trend). On multivariate analysis, black race (odds ratio, 1.8; 95% CI, 1.7-2.0), Hispanic ethnicity (odds ratio, 1.6; 95% CI, 1.4-1.8), and advancing age were associated with significantly higher odds of having a diabetes-related visit. Despite a marked increase in number and proportion of diabetes-related ED visits during the study period, the per capita use of ED services for diabetes-related visits among the diabetic population remained stable. Copyright © 2012 Elsevier Inc. All rights reserved.
Recent trends in the frequency and duration of global floods
NASA Astrophysics Data System (ADS)
Najibi, Nasser; Devineni, Naresh
2018-06-01
Frequency and duration of floods are analyzed using the global flood database of the Dartmouth Flood Observatory (DFO) to explore evidence of trends during 1985-2015 at global and latitudinal scales. Three classes of flood duration (i.e., short: 1-7, moderate: 8-20, and long: 21 days and above) are also considered for this analysis. The nonparametric Mann-Kendall trend analysis is used to evaluate three hypotheses addressing potential monotonic trends in the frequency of flood, moments of duration, and frequency of specific flood duration types. We also evaluated if trends could be related to large-scale atmospheric teleconnections using a generalized linear model framework. Results show that flood frequency and the tails of the flood duration (long duration) have increased at both the global and the latitudinal scales. In the tropics, floods have increased 4-fold since the 2000s. This increase is 2.5-fold in the north midlatitudes. However, much of the trend in frequency and duration of the floods can be placed within the long-term climate variability context since the Atlantic Multidecadal Oscillation, North Atlantic Oscillation, and Pacific Decadal Oscillation were the main atmospheric teleconnections explaining this trend. There is no monotonic trend in the frequency of short-duration floods across all the global and latitudinal scales. There is a significant increasing trend in the annual median of flood durations globally and each latitudinal belt, and this trend is not related to these teleconnections. While the DFO data come with a certain level of epistemic uncertainty due to imprecision in the estimation of floods, overall, the analysis provides insights for understanding the frequency and persistence in hydrologic extremes and how they relate to changes in the climate, organization of global and local dynamical systems, and country-scale socioeconomic factors.
Li, Yi; Yao, Ning; Chau, Henry Wai
2017-08-15
Reference crop evapotranspiration (ET o ) is a key parameter in field irrigation scheduling, drought assessment and climate change research. ET o uses key prescribed (or fixed or reference) land surface parameters for crops. The linear and nonlinear trends in different climatic variables (CVs) affect ET o change. This research aims to reveal how ET o responds after the related CVs were linearly and nonlinearly detrended over 1961-2013 in Xinjiang, China. The ET o -related CVs included minimum (T min ), average (T ave ), and maximum air temperatures (T max ), wind speed at 2m (U 2 ), relative humidity (RH) and sunshine hour (n). ET o was calculated using the Penman-Monteith equation. A total of 29 ET o scenarios, including the original scenario, 14 scenarios in Group I (ET o was recalculated after removing linear trends from single or more CVs) and 14 scenarios in Group II (ET o was recalculated after removing nonlinear trends from the CVs), were generated. The influence of U 2 was stronger than influences of the other CVs on ET o for both Groups I and II either in northern, southern or the entirety of Xinjiang. The weak influences of increased T min , T ave and T max on increasing ET o were masked by the strong effects of decreased U 2 &n and increased RH on decreasing ET o . The effects of the trends in CVs, especially U 2 , on changing ET o were clearly shown. Without the general decreases of U 2 , ET o would have increased in the past 53years. Due to the non-monotone variations of the CVs and ET o , the results of nonlinearly detrending CVs on changing ET o in Group II should be more plausible than the results of linearly detrending CVs in Group I. The decreasing ET o led to a general relief in drought, which was indicated by the recalculated aridity index. Therefore, there would be a slightly lower risk of water utilization in Xinjiang, China. Copyright © 2017 Elsevier B.V. All rights reserved.
Angus, Colin; Holmes, John; Maheswaran, Ravi; Green, Mark A; Meier, Petra; Brennan, Alan
2017-04-12
Much literature examines the relationship between the spatial availability of alcohol and alcohol-related harm. This study aims to address an important gap in this evidence by using detailed outlet data to examine recent temporal trends in the sociodemographic distribution of spatial availability for different types of alcohol outlet in England. Descriptive analysis of measures of alcohol outlet density and proximity using extremely high resolution market research data stratified by outlet type and quintiles of area-level deprivation from 2003, 2007, 2010 and 2013 was undertaken and hierarchical linear growth models fitted to explore the significance of socioeconomic differences. We find that overall availability of alcohol changed very little from 2003 to 2013 (density +1.6%), but this conceals conflicting trends by outlet type and area-level deprivation. Mean on-trade density has decreased substantially (-2.2 outlets within 1 km (Inter-Quartile Range (IQR) -3-0), although access to restaurants has increased (+1.0 outlets (IQR 0-1)), while off-trade access has risen substantially (+2.4 outlets (IQR 0-3)). Availability is highest in the most deprived areas ( p < 0.0001) although these areas have also seen the greatest falls in on-trade outlet availability ( p < 0.0001). This study underlines the importance of using detailed, low-level geographic data to understand patterns and trends in the spatial availability of alcohol. There are significant variations in these trends by outlet type and deprivation level which may have important implications for health inequalities and public health policy.
Angus, Colin; Holmes, John; Maheswaran, Ravi; Green, Mark A.; Meier, Petra; Brennan, Alan
2017-01-01
Much literature examines the relationship between the spatial availability of alcohol and alcohol-related harm. This study aims to address an important gap in this evidence by using detailed outlet data to examine recent temporal trends in the sociodemographic distribution of spatial availability for different types of alcohol outlet in England. Descriptive analysis of measures of alcohol outlet density and proximity using extremely high resolution market research data stratified by outlet type and quintiles of area-level deprivation from 2003, 2007, 2010 and 2013 was undertaken and hierarchical linear growth models fitted to explore the significance of socioeconomic differences. We find that overall availability of alcohol changed very little from 2003 to 2013 (density +1.6%), but this conceals conflicting trends by outlet type and area-level deprivation. Mean on-trade density has decreased substantially (−2.2 outlets within 1 km (Inter-Quartile Range (IQR) −3–0), although access to restaurants has increased (+1.0 outlets (IQR 0–1)), while off-trade access has risen substantially (+2.4 outlets (IQR 0–3)). Availability is highest in the most deprived areas (p < 0.0001) although these areas have also seen the greatest falls in on-trade outlet availability (p < 0.0001). This study underlines the importance of using detailed, low-level geographic data to understand patterns and trends in the spatial availability of alcohol. There are significant variations in these trends by outlet type and deprivation level which may have important implications for health inequalities and public health policy. PMID:28417941
Dollars for lives: the effect of highway capital investments on traffic fatalities.
Nguyen-Hoang, Phuong; Yeung, Ryan
2014-12-01
This study examines the effect of highway capital investments on highway fatalities. We used state-level data from the 48 contiguous states in the United States from 1968 through 2010 to estimate the effects on highway fatalities of capital expenditures and highway capital stock. We estimated these effects by controlling for a set of control variables together with state and year dummy variables and state-specific linear time trends. We found that capital expenditures and capital stock had significant and negative effects on highway fatalities. States faced with declines in gas tax revenues have already cut back drastically on spending on roads including on maintenance and capital outlay. If this trend continues, it may undermine traffic safety. While states and local governments are currently fiscally strained, it is important for them to continue investments in roadways to enhance traffic safety and, more significantly, to save lives. Copyright © 2014 National Safety Council and Elsevier Ltd. All rights reserved.
Trend analysis of the wave storminess: the wave direction
NASA Astrophysics Data System (ADS)
Casas Prat, M.; Sierra, J. P.; Mösso, C.; Sánchez-Arcilla, A.
2009-09-01
Climate change has an important role in the current scientific research because of its possible future negative consequences. Concerning the climate change in the coastal engineering field, the apparent sea level rise is one of the key parameters as well as the wave height and the wave direction temporal variations. According to the IPCC (2007), during the last century the sea level has been increasing with a mean rate of 1.7 ± 0.5 mm/yr. However, at local/regional scale the tendency significantly differs from the global trend since the local pressure and wind field variations become more relevant. This appears to be particularly significant in semi-enclosed areas in the Mediterranean Sea (Cushman-Roisin et al., 2001). Even though the existing unsolved questions related to the sea level rise, the uncertainty concerning the wave height is even larger, in which stormy conditions are especially important because they are closely related to processes such as coastal erosion, flooding, etc. Therefore, it is necessary to identify possible existing tendencies of storm related parameters. In many studies, only the maximum wave height and storm duration are analysed, remaining the wave direction in a second term. Note that a possible rotation of the mean wave direction may involve severe consequences since most beach and harbour defence structures have been designed assuming a constant predominant wave incidence. Liste et al. (2004) illustrated this fact with an example in which a rotation of only 2 degrees of the mean energy flux vector could produce a beach retreat of 20 m. Another possible consequence would be a decrease of the harbour operability: increased frequency of storms in the same direction as the harbour entrance orientation would influence the navigability. The present study, which focuses in the Catalan coast (NW Mediterranean Sea), aims to improve the present knowledge of the wave storminess variations at regional scale, specially focusing on the wave directionality. It is based on 44 year hindcast model data (1958-2001) of the HIPOCAS project, enabling to work with a longer time series compared to the existing measured ones. 41 nodes of this database are used, containing 3 hourly simulated data of significant wave height and wave direction, among other parameters. For storm definition, the Peak Over Threshold (POT) method is used with some additional duration requirements in order to analyse statistically independent events (Mendoza & Jiménez, 2006). Including both wave height and storm duration, the wave storminess is characterised by the energy content (Mendoza & Jiménez, 2004), being in turn log-transformed because of its positive scale. Separately, the wave directionality itself is analysed in terms of different sectors and approaching their probability of occurrence by counting events and using Bayesian inference (Agresti, 2002). Therefore, the original data is transformed into compositional data and, before performing the trend analysis, the isometric logratio (ilr) transformation (Egozcue et al., 2003) is done. In general, the trend analysis methodology consists in two steps: 1) trend detection and 2) trend quantification. For 1) the Mann Kendall test is used in order to identify the nodes with significant trend. For these selected nodes, the trend quantification is done, comparing two methods: 1) a simple linear regression analysis complemented with the bootstrap technique and 2) a Bayesian analysis, assuming normally distributed data with linearly increasing mean. Preliminary results show no significant trend for both annual mean and maximum energy content except for some nodes located to the Northern Catalan coast. Regarding the wave direction (but not only considering stormy conditions) there is a tendency of North direction to decrease whereas South and Southeast direction seems to increase.
Long-term exposure to crystalline silica and risk of heart disease mortality.
Liu, Yuewei; Rong, Yi; Steenland, Kyle; Christiani, David C; Huang, Xiji; Wu, Tangchun; Chen, Weihong
2014-09-01
The association between crystalline silica exposure and risk of heart disease mortality remains less clear. We investigated a cohort of 42,572 Chinese workers who were potentially exposed to crystalline silica and followed from 1960 to 2003. Cumulative silica exposure was estimated by linking a job-exposure matrix to each person's work history. Low-level silica exposure was defined as never having held a job with an exposure higher than 0.1 mg/m. We estimated hazard ratios (HRs) in exposure-response analyses using Cox proportional hazards model. We identified 2846 deaths from heart disease during an average of 35 years follow-up. Positive exposure-response trends were observed for cumulative silica exposure associated with mortality from total heart disease (HRs for increasing quartiles of cumulative silica exposure compared with the unexposed group = 0.89, 1.09, 1.32, 2.10; P for linear trend < 0.001) and pulmonary heart disease (0.92, 1.39, 2.47, 5.46; P for linear trend < 0.001). These positive trends remained among workers with both high- and low-level silica exposure. There was also a positive trend for ischemic heart disease among workers with low-level exposure, with quartile HRs of 1.04, 1.13, 1.52, and 1.60 (P for linear trend < 0.001). Low-level crystalline silica exposure was associated with increased mortality from heart disease, including pulmonary heart disease and ischemic heart disease, whereas high-level exposure mainly increased mortality from pulmonary heart disease. Current permissible exposure limits for crystalline silica in many countries may be insufficient to protect people from deaths due to heart disease.
Cross-conditional entropy and coherence analysis of pharmaco-EEG changes induced by alprazolam.
Alonso, J F; Mañanas, M A; Romero, S; Rojas-Martínez, M; Riba, J
2012-06-01
Quantitative analysis of electroencephalographic signals (EEG) and their interpretation constitute a helpful tool in the assessment of the bioavailability of psychoactive drugs in the brain. Furthermore, psychotropic drug groups have typical signatures which relate biochemical mechanisms with specific EEG changes. To analyze the pharmacological effect of a dose of alprazolam on the connectivity of the brain during wakefulness by means of linear and nonlinear approaches. EEG signals were recorded after alprazolam administration in a placebo-controlled crossover clinical trial. Nonlinear couplings assessed by means of corrected cross-conditional entropy were compared to linear couplings measured with the classical magnitude squared coherence. Linear variables evidenced a statistically significant drug-induced decrease, whereas nonlinear variables showed significant increases. All changes were highly correlated to drug plasma concentrations. The spatial distribution of the observed connectivity changes clearly differed from a previous study: changes before and after the maximum drug effect were mainly observed over the anterior half of the scalp. Additionally, a new variable with very low computational cost was defined to evaluate nonlinear coupling. This is particularly interesting when all pairs of EEG channels are assessed as in this study. Results showed that alprazolam induced changes in terms of uncoupling between regions of the scalp, with opposite trends depending on the variables: decrease in linear ones and increase in nonlinear features. Maps provided consistent information about the way brain changed in terms of connectivity being definitely necessary to evaluate separately linear and nonlinear interactions.
von Ruesten, Anne; Steffen, Annika; Floegel, Anna; van der A, Daphne L.; Masala, Giovanna; Tjønneland, Anne; Halkjaer, Jytte; Palli, Domenico; Wareham, Nicholas J.; Loos, Ruth J. F.; Sørensen, Thorkild I. A.; Boeing, Heiner
2011-01-01
Objective To investigate trends in obesity prevalence in recent years and to predict the obesity prevalence in 2015 in European populations. Methods Data of 97 942 participants from seven cohorts involved in the European Prospective Investigation into Cancer and Nutrition (EPIC) study participating in the Diogenes project (named as “Diogenes cohort” in the following) with weight measurements at baseline and follow-up were used to predict future obesity prevalence with logistic linear and non-linear (leveling off) regression models. In addition, linear and leveling off models were fitted to the EPIC-Potsdam dataset with five weight measures during the observation period to find out which of these two models might provide the more realistic prediction. Results During a mean follow-up period of 6 years, the obesity prevalence in the Diogenes cohort increased from 13% to 17%. The linear prediction model predicted an overall obesity prevalence of about 30% in 2015, whereas the leveling off model predicted a prevalence of about 20%. In the EPIC-Potsdam cohort, the shape of obesity trend favors a leveling off model among men (R2 = 0.98), and a linear model among women (R2 = 0.99). Conclusion Our data show an increase in obesity prevalence since the 1990ies, and predictions by 2015 suggests a sizeable further increase in European populations. However, the estimates from the leveling off model were considerably lower. PMID:22102897
Park, Kyong; Son, Jakyung; Jang, Jiyoung; Kang, Ryungwoo; Chung, Hye-Kyung; Lee, Kyong Won; Lee, Seung-Min; Lim, Hyunjung; Shin, Min-Jeong
2017-01-01
Meat consumption has been shown to be associated with cardiovascular disease (CVD) risk in Western societies; however, epidemiological data are limited on the Korean population. Therefore, we examined the associations between unprocessed meat consumption and CVD incidence in Korea. Data were derived from the Ansung-Ansan cohort (2001–2012), including 9370 adults (40–69 years) without CVD or cancer at baseline. Total unprocessed meat consumption was estimated as the sum of unprocessed red meat (beef, pork, and organ meat) and poultry consumption. In the fully adjusted Cox regression model, the relative risks of CVD across increasing quintiles of total unprocessed meat intake were 1.0 (reference), 0.72 (95% confidence interval (CI): 0.55, 0.95), 0.57 (95% CI: 0.42, 0.78), 0.69 (95% CI: 0.51, 0.95), and 0.69 (95% CI: 0.48, 0.97), but no significant linear trend was detected (p for trend = 0.14). Frequent poultry consumption was significantly associated with a decreased CVD risk; this association showed a dose-response relationship (p for trend = 0.04). This study showed that a moderate intake of total unprocessed meat was inversely associated with CVD risk. A significant inverse association between poultry consumption and incident CVD was observed in Korean adults, requiring further confirmation in other populations. PMID:28505126
Observed increase in extreme daily rainfall in the French Mediterranean
NASA Astrophysics Data System (ADS)
Ribes, Aurélien; Thao, Soulivanh; Vautard, Robert; Dubuisson, Brigitte; Somot, Samuel; Colin, Jeanne; Planton, Serge; Soubeyroux, Jean-Michel
2018-04-01
We examine long-term trends in the historical record of extreme precipitation events occurring over the French Mediterranean area. Extreme events are considered in terms of their intensity, frequency, extent and precipitated volume. Changes in intensity are analysed via an original statistical approach where the annual maximum rainfall amounts observed at each measurement station are aggregated into a univariate time-series according to their dependence. The mean intensity increase is significant and estimated at + 22% (+ 7 to + 39% at the 90% confidence level) over the 1961-2015 period. Given the observed warming over the considered area, this increase is consistent with a rate of about one to three times that implied by the Clausius-Clapeyron relationship. Changes in frequency and other spatial features are investigated through a Generalised Linear Model. Changes in frequency for events exceeding high thresholds (about 200 mm in 1 day) are found to be significant, typically near a doubling of the frequency, but with large uncertainties in this change ratio. The area affected by severe events and the water volume precipitated during those events also exhibit significant trends, with an increase by a factor of about 4 for a 200 mm threshold, again with large uncertainties. All diagnoses consistently point toward an intensification of the most extreme events over the last decades. We argue that it is difficult to explain the diagnosed trends without invoking the human influence on climate.
Moltchanova, E; Eriksson, J G
2015-08-01
Changes in anthropometrics often reflect changes in living conditions, and one's characteristics at birth may be associated with future health. The aim of this study was to investigate the secular trends in maternal and neonatal anthropometrics in the Helsinki Birth Cohort Study. The study participants, thus, comprised all 13,345 live births recorded in Helsinki, Finland, between 1934 and 1944. Adult characteristics of the clinical subsample comprised of 2003 individuals, alive during 2003, were also analyzed. Linear Regression analysis with seasonal terms was applied to see whether clinically and statistically significant trends can be found in maternal age, height and body mass index (BMI) at pregnancy; gestational age, birth weight, ponderal index and sex ratio; and adult height, BMI and fat percentage. Statistically significant trends were found in maternal age and maternal BMI with abrupt changes between 1941 and 1944. Gestational age increased by an average of 0.11% per year (P<0.0001), and the proportion of premature births dropped from 7.9% in 1934 to 4.5% in 1944 (P<0.0001). In the clinical sample, a statistically significant, although small, average annual increase of 0.1% in adult heights was detected (P=0.0012 for men and P=0.0035 for women). In conclusion, although no significant changes were found in either neonatal or adult anthropometrics of babies born in Helsinki between 1934 and 1944, there were abrupt changes in the characteristics of their mothers.
Ahmed, Awad A; Hwang, Wei-Ting; Thomas, Charles R; Deville, Curtiland
2018-04-01
Data show that international medical graduates (IMGs), both US and foreign born, are more likely to enter primary care specialties and practice in underserved areas. Comprehensive assessments of representation trends for IMGs in the US physician workforce are limited. We reported current and historical representation trends for IMGs in the graduate medical education (GME) training pool and US practicing physician workforce. We compared representation for the total GME and active practicing physician pools with the 20 largest residency specialties. A 2-sided test was used for comparison, with P < .001 considered significant. To assess significant increases in IMG GME trainee representation for the total pool and each of the specialties from 1990-2015, the slope was estimated using simple linear regression. IMGs showed significantly greater representation among active practicing physicians in 4 specialties: internal medicine (39%), neurology (31%), psychiatry (30%), and pediatrics (25%). IMGs in GME showed significantly greater representation in 5 specialties: pathology (39%), internal medicine (39%), neurology (36%), family medicine (32%), and psychiatry (31%; all P < .001). Over the past quarter century, IMG representation in GME has increased by 0.2% per year in the total GME pool, and 1.1% per year for family medicine, 0.5% for obstetrics and gynecology and general surgery, and 0.3% for internal medicine. IMGs make up nearly a quarter of the total GME pool and practicing physician workforce, with a disproportionate share, and larger increases over our study period in certain specialties.
Trend Analysis Using Microcomputers.
ERIC Educational Resources Information Center
Berger, Carl F.
A trend analysis statistical package and additional programs for the Apple microcomputer are presented. They illustrate strategies of data analysis suitable to the graphics and processing capabilities of the microcomputer. The programs analyze data sets using examples of: (1) analysis of variance with multiple linear regression; (2) exponential…
Moxnes, John F; de Blasio, Birgitte Freiesleben; Leegaard, Truls Michael; Moen, Aina E Fossum
2013-01-01
Accurate estimates of the incidence and prevalence of methicillin-resistant Staphylococcus aureus (MRSA) infections are needed to inform public health policies. In Norway, where both MRSA infection and carriage are notifiable conditions, the reported incidence of MRSA is slowly increasing. However, the proportion of MRSA in relation to all S. aureus isolates is unknown, making it difficult to determine if the rising incidence is real or an artifact of an increasing number of tests performed. To characterize recent trends in MRSA infections and obtain a more complete understanding of the MRSA level in Norway. All reported cases of MRSA and methicillin-sensitive S. aureus (MSSA) from Oslo County (1997-2010) and Health Region East (2008-2008), representing approximately 11% and 36% of the Norwegian population, respectively, were analyzed using a stochastic time series analysis to characterize trends. In Oslo County, the proportion of methicillin-resistant cases increased from 0.73% to 3.78% during the study period and was well modeled by an exponential growth with a doubling constant of 5.7 years (95% CI 4.5-7.4 years). In Health Region East, the proportion of MRSA cases increased from 0.4% to 2.1% from 2002 to 2008, with a best-fitting linear increase of 0.26% (95% CI 0.21-0.30%) per year. In both cases, the choice of a linear or exponential model for the time trend produced only marginally different model fits. We found no significant changes due to revised national MRSA guidelines published in June 2009. Significant variations in the increasing time trend were observed in the five hospitals within the region. The yearly reported incidence of MSSA was relatively stable in both study areas although we found seasonal patterns with peaks in August. The level of MRSA is increasing in Norway, and the proportion of methicillin resistance in all S. aureus isolates are higher than the reported proportion of MRSA in invasive infections.
Moxnes, John F.; de Blasio, Birgitte Freiesleben; Leegaard, Truls Michael; Moen, Aina E. Fossum
2013-01-01
Background Accurate estimates of the incidence and prevalence of methicillin-resistant Staphylococcus aureus (MRSA) infections are needed to inform public health policies. In Norway, where both MRSA infection and carriage are notifiable conditions, the reported incidence of MRSA is slowly increasing. However, the proportion of MRSA in relation to all S. aureus isolates is unknown, making it difficult to determine if the rising incidence is real or an artifact of an increasing number of tests performed. Aim To characterize recent trends in MRSA infections and obtain a more complete understanding of the MRSA level in Norway. Methods All reported cases of MRSA and methicillin-sensitive S. aureus (MSSA) from Oslo County (1997–2010) and Health Region East (2008–2008), representing approximately 11% and 36% of the Norwegian population, respectively, were analyzed using a stochastic time series analysis to characterize trends. Results In Oslo County, the proportion of methicillin-resistant cases increased from 0.73% to 3.78% during the study period and was well modeled by an exponential growth with a doubling constant of 5.7 years (95% CI 4.5–7.4 years). In Health Region East, the proportion of MRSA cases increased from 0.4% to 2.1% from 2002 to 2008, with a best-fitting linear increase of 0.26% (95% CI 0.21–0.30%) per year. In both cases, the choice of a linear or exponential model for the time trend produced only marginally different model fits. We found no significant changes due to revised national MRSA guidelines published in June 2009. Significant variations in the increasing time trend were observed in the five hospitals within the region. The yearly reported incidence of MSSA was relatively stable in both study areas although we found seasonal patterns with peaks in August. Conclusion The level of MRSA is increasing in Norway, and the proportion of methicillin resistance in all S. aureus isolates are higher than the reported proportion of MRSA in invasive infections. PMID:23936442
Investigation of the 16-year and 18-year ZTD Time Series Derived from GPS Data Processing
NASA Astrophysics Data System (ADS)
Bałdysz, Zofia; Nykiel, Grzegorz; Figurski, Mariusz; Szafranek, Karolina; KroszczyńSki, Krzysztof
2015-08-01
The GPS system can play an important role in activities related to the monitoring of climate. Long time series, coherent strategy, and very high quality of tropospheric parameter Zenith Tropospheric Delay (ZTD) estimated on the basis of GPS data analysis allows to investigate its usefulness for climate research as a direct GPS product. This paper presents results of analysis of 16-year time series derived from EUREF Permanent Network (EPN) reprocessing performed by the Military University of Technology. For 58 stations Lomb-Scargle periodograms were performed in order to obtain information about the oscillations in ZTD time series. Seasonal components and linear trend were estimated using Least Square Estimation (LSE) and Mann—Kendall trend test was used to confirm the presence of a linear trend designated by LSE method. In order to verify the impact of the length of time series on trend value, comparison between 16 and 18 years were performed.
Geologic and mineral and water resources investigations in western Colorado using ERTS-1 data
NASA Technical Reports Server (NTRS)
Knepper, D. H., Jr. (Principal Investigator); Hutchinson, R. M.; Sawatzky, D. L.; Trexler, D. W.; Bruns, D. L.; Nicolais, S. M.
1973-01-01
The author has identified the following significant results. Topography was found to be the most important factor defining folds on ERTS-1 imagery of northwestern Colorado; tonal variations caused by rock reflectance and vegetation type and density are the next most important factors. Photo-linears mapped on ERTS-1 imagery of central Colorado correlate well with ground-measured joint and fracture trends. In addition, photo-linears have been successfully used to determine the location and distribution of metallic mineral deposits in the Colorado Mineral Belt. True color composites are best for general geologic analysis and false color composites prepared with positive/negative masks are useful for enhancing local geologic phenomena. During geologic analysis of any given area, ERTS-1 imagery from several different dates should be studied.
Spatial and temporal variation of rainfall trends of Sri Lanka
NASA Astrophysics Data System (ADS)
Wickramagamage, P.
2016-08-01
This study was based on daily rainfall data of 48 stations distributed over the entire island covering a 30-year period from 1981 to 2010. Data analysis was done to identify the spatial pattern of rainfall trends. The methods employed in data analysis are linear regression and interpolation by Universal Kriging and Radial Basis function. The slope of linear regression curves of 48 stations was used in interpolation. The regression coefficients show spatially and seasonally variable positive and negative trends of annual and seasonal rainfall. About half of the mean annual pentad series show negative trends, while the rest shows positive trends. By contrast, the rainfall trends of the Southwest Monsoon (SWM) season are predominantly negative throughout the country. The first phase of the Northeast Monsoon (NEM1) displays downward trends everywhere, with the exception of the Southeastern coastal area. The strongest negative trends were found in the Northeast and in the Central Highlands. The second phase (NEM2) is mostly positive, except in the Northeast. The Inter-Monsoon (IM) periods have predominantly upward trends almost everywhere, but still the trends in some parts of the Highlands and Northeast are negative. The long-term data at Watawala Nuwara Eliya and Sandringham show a consistent decline in the rainfall over the last 100 years, particularly during the SWM. There seems to be a faster decline in the rainfall in the last 3 decades. These trends are consistent with the observations in India. It is generally accepted that there has been changes in the circulation pattern. Weakening of the SWM circulation parameters caused by global warming appears to be the main causes of recent changes. Effect of the Asian Brown Cloud may also play a role in these changes.
Macroeconomic effects on mortality revealed by panel analysis with nonlinear trends.
Ionides, Edward L; Wang, Zhen; Tapia Granados, José A
2013-10-03
Many investigations have used panel methods to study the relationships between fluctuations in economic activity and mortality. A broad consensus has emerged on the overall procyclical nature of mortality: perhaps counter-intuitively, mortality typically rises above its trend during expansions. This consensus has been tarnished by inconsistent reports on the specific age groups and mortality causes involved. We show that these inconsistencies result, in part, from the trend specifications used in previous panel models. Standard econometric panel analysis involves fitting regression models using ordinary least squares, employing standard errors which are robust to temporal autocorrelation. The model specifications include a fixed effect, and possibly a linear trend, for each time series in the panel. We propose alternative methodology based on nonlinear detrending. Applying our methodology on data for the 50 US states from 1980 to 2006, we obtain more precise and consistent results than previous studies. We find procyclical mortality in all age groups. We find clear procyclical mortality due to respiratory disease and traffic injuries. Predominantly procyclical cardiovascular disease mortality and countercyclical suicide are subject to substantial state-to-state variation. Neither cancer nor homicide have significant macroeconomic association.
Macroeconomic effects on mortality revealed by panel analysis with nonlinear trends
Ionides, Edward L.; Wang, Zhen; Tapia Granados, José A.
2013-01-01
Many investigations have used panel methods to study the relationships between fluctuations in economic activity and mortality. A broad consensus has emerged on the overall procyclical nature of mortality: perhaps counter-intuitively, mortality typically rises above its trend during expansions. This consensus has been tarnished by inconsistent reports on the specific age groups and mortality causes involved. We show that these inconsistencies result, in part, from the trend specifications used in previous panel models. Standard econometric panel analysis involves fitting regression models using ordinary least squares, employing standard errors which are robust to temporal autocorrelation. The model specifications include a fixed effect, and possibly a linear trend, for each time series in the panel. We propose alternative methodology based on nonlinear detrending. Applying our methodology on data for the 50 US states from 1980 to 2006, we obtain more precise and consistent results than previous studies. We find procyclical mortality in all age groups. We find clear procyclical mortality due to respiratory disease and traffic injuries. Predominantly procyclical cardiovascular disease mortality and countercyclical suicide are subject to substantial state-to-state variation. Neither cancer nor homicide have significant macroeconomic association. PMID:24587843
Soil pH determines fungal diversity along an elevation gradient in Southwestern China.
Liu, Dan; Liu, Guohua; Chen, Li; Wang, Juntao; Zhang, Limei
2018-01-03
Fungi play important roles in ecosystem processes, and the elevational pattern of fungal diversity is still unclear. Here, we examined the diversity of fungi along a 1,000 m elevation gradient on Mount Nadu, Southwestern China. We used MiSeq sequencing to obtain fungal sequences that were clustered into operational taxonomic units (OTUs) and to measure the fungal composition and diversity. Though the species richness and phylogenetic diversity of the fungal community did not exhibit significant trends with increasing altitude, they were significantly lower at mid-altitudinal sites than at the base. The Bray-Curtis distance clustering also showed that the fungal communities varied significantly with altitude. A distance-based linear model multivariate analysis (DistLM) identified that soil pH dominated the explanatory power of the species richness (23.72%), phylogenetic diversity (24.25%) and beta diversity (28.10%) of the fungal community. Moreover, the species richness and phylogenetic diversity of the fungal community increased linearly with increasing soil pH (P<0.05). Our study provides evidence that pH is an important predictor of soil fungal diversity along elevation gradients in Southwestern China.
Nkoke, Clovis; Balti, Eric; Menanga, Alain; Dzudie, Anastase; Lekoubou, Alain; Kingue, Samuel; Kengne, Andre Pascal
2017-01-01
Congenital heart disease (CHD) is a common condition in children in Sub-Saharan Africa (SSA), where it is associated with poor outcomes. Diagnosis of CHD in SSA depends essentially on echocardiography, which is available only in few urban referral centers. Our aim was to assess time changes in the pattern of referral for pediatric echocardiography and the subsequent diagnosis of structural CHD in a major SSA city. All pediatric echocardiography performed between 2004 and 2013 at the echocardiography laboratory of the Yaounde General Hospital were reviewed. The primary indication of the study and the presence of structural CHD were recorded. Between 2004 and 2013, 9,390 echocardiograms were performed and 834 (8.9%) children aged 1 day to 15 years underwent echocardiography at the center, and 227 (27.2%) cases of definite structural CHD were diagnosed, with 123 (54.2%) in boys. The most frequent indications for echocardiography were heart murmurs (40%) and the suspicion of CHD (37.4%). The commonest CHD was ventricular septal defect (VSD) (30%) with tetralogy of Fallot being the most frequent cyanotic heart lesion (5.3%). The proportion of pediatric echocardiography decreased from 13.3% in 2004-2005 to 6.1% in 2012-2013 (P=0.001) but not in a linear fashion (P=0.072 for linear trend).The diagnosis of structural CHD increased from 25.1% in 2004-2005 to 27.1% in 2012-2013. This increase however was non-significant (P=0.523) and did not follow a linear trend (P=0.230). The pattern of referral for pediatric echocardiography at this center has changed over time, but diagnosis of structural CHD has remained the same. Improving access to this diagnostic procedure and subsequent treatment of diagnosed CHD will help improving the outcome of the disease in this setting.
Crewe, Tara L; Taylor, Philip D; Lepage, Denis
2015-01-01
The use of counts of unmarked migrating animals to monitor long term population trends assumes independence of daily counts and a constant rate of detection. However, migratory stopovers often last days or weeks, violating the assumption of count independence. Further, a systematic change in stopover duration will result in a change in the probability of detecting individuals once, but also in the probability of detecting individuals on more than one sampling occasion. We tested how variation in stopover duration influenced accuracy and precision of population trends by simulating migration count data with known constant rate of population change and by allowing daily probability of survival (an index of stopover duration) to remain constant, or to vary randomly, cyclically, or increase linearly over time by various levels. Using simulated datasets with a systematic increase in stopover duration, we also tested whether any resulting bias in population trend could be reduced by modeling the underlying source of variation in detection, or by subsampling data to every three or five days to reduce the incidence of recounting. Mean bias in population trend did not differ significantly from zero when stopover duration remained constant or varied randomly over time, but bias and the detection of false trends increased significantly with a systematic increase in stopover duration. Importantly, an increase in stopover duration over time resulted in a compounding effect on counts due to the increased probability of detection and of recounting on subsequent sampling occasions. Under this scenario, bias in population trend could not be modeled using a covariate for stopover duration alone. Rather, to improve inference drawn about long term population change using counts of unmarked migrants, analyses must include a covariate for stopover duration, as well as incorporate sampling modifications (e.g., subsampling) to reduce the probability that individuals will be detected on more than one occasion.
Trends in extreme daily temperatures and humidex index in the United Arab Emirates over 1948-2014.
NASA Astrophysics Data System (ADS)
Yang, H. W.; Ouarda, T.
2015-12-01
This study deals with the analysis of the characteristics of extreme temperature events in the Middle East, using NCEP reanalysis gridded data, for the summer (May-October) and winter (November-April) seasons. Trends in the occurrences of three types of heat spells during 1948-2014 are studied by both Linear Regression (LR) and Mann-Kendall (MK) test. Changes in the diurnal temperature range (DTR) are also investigated. To better understand the effects of heat spells on public health, the Humidex, a combination index of ambient temperature and relative humidity, is also used. Using percentile threshold, temperature (Humidex) Type-A and Type-B heat spells are defined respectively by daily maximum and minimum temperature (Humidex). Type-C heat spells are defined as the joint occurrence of Type-A and Type-B heat spells at the same time. In the Middle East, it is found that no coherent trend in temperature Type-A heat spells is observed. However, the occurrences of temperature Type-B and C heat spells have consistently increased since 1948. For Humidex heat spells, coherently increased activities of all three types of heat spells are observed in the area. During the summer, the magnitude of the positive trends in Humidex heat spells are generally stronger than temperature heat spells. More than half of the locations in the area show significantly negative DTR trends in the summer, but the trends vary according to the region in the winter. Annual mean temperature has increased an average by 0.5°C, but it is mainly associated with the daily minimum temperature which has warmed up by 0.84°C.Daily maximum temperature showed no significant trends. The warming is hence stronger in minimum temperatures than in maximum temperatures resulting in a decrease in DTR by 0.16 °C per decade. This study indicates hence that the UAE has not become hotter, but it has become less cold during 1948 to 2014.
Chang, Man-Huei; Moonesinghe, Ramal; Athar, Heba M; Truman, Benedict I
2016-01-01
Temporal trends in disparities in the leading causes of death within and between US demographic subgroups indicate the need for and success of interventions to prevent premature death in vulnerable populations. Studies that report recent trends are limited and outdated. To describe temporal trends in disparities in death rates by sex and race/ethnicity for the 10 leading causes of death in the United States during 1999-2010. We used underlying cause of death data and population estimates from the National Vital Statistics System to calculate age-adjusted death rates for the 10 leading causes of death during 1999-2010. We measured absolute and relative disparities by sex and race/ethnicity for each cause and year of death; we used weighted linear regression to test for significance of trends over time. Of the 10 leading causes of death, age-adjusted death rates by sex and race/ethnicity declined during 1999-2010 for 6 causes and increased for 4 causes. But sex and racial/ethnic disparities between groups persisted for each year and cause of death. In the US population, the decreasing trend during 1999-2010 was greatest for cerebrovascular disease (-36.5%) and the increasing trend was greatest for Alzheimer disease (52.4%). For each sex and year, the disparity in death rates between Asian/Pacific Islanders (API) and other groups varied significantly by cause of death. In 2010, the API-non-Hispanic black disparity was largest for heart disease, malignant neoplasms, cerebrovascular diseases, and nephritis; the API-American Indian/Alaska Native disparity was largest for unintentional injury, diabetes mellitus, influenza and pneumonia, and suicide; and the API-non-Hispanic white disparity was largest for chronic lower respiratory diseases and Alzheimer disease. Public health practitioners can use these findings to improve policies and practices and to evaluate progress in eliminating disparities and their social determinants in vulnerable populations.
Within crown variation in the relationship between foliage biomass and sapwood area in jack pine.
Schneider, Robert; Berninger, Frank; Ung, Chhun-Huor; Mäkelä, Annikki; Swift, D Edwin; Zhang, S Y
2011-01-01
The relationship between sapwood area and foliage biomass is the basis for a lot of research on eco-phyisology. In this paper, foliage biomass change between two consecutive whorls is studied, using different variations in the pipe model theory. Linear and non-linear mixed-effect models relating foliage differences to sapwood area increments were tested to take into account whorl location, with the best fit statistics supporting the non-linear formulation. The estimated value of the exponent is 0.5130, which is significantly different from 1, the expected value given by the pipe model theory. When applied to crown stem sapwood taper, the model indicates that foliage biomass distribution influences the foliage biomass to sapwood area at crown base ratio. This result is interpreted as being the consequence of differences in the turnover rates of sapwood and foliage. More importantly, the model explains previously reported trends in jack pine sapwood area at crown base to tree foliage biomass ratio.
Stratospheric ozone profile and total ozone trends derived from the SAGE I and SAGE II data
NASA Technical Reports Server (NTRS)
Mccormick, M. P.; Veiga, Robert E.; Chu, William P.
1992-01-01
Global trends in both stratospheric column ozone and as a function of altitude are derived on the basis of SAGE I/II ozone data from the period 1979-1991. A statistical model containing quasi-biennial, seasonal, and semiannual oscillations, a linear component, and a first-order autoregressive noise process was fit to the time series of SAGE I/II monthly zonal mean data. The linear trend in column ozone above 17-km altitude, averaged between 65 deg S and 65 deg N, is -0.30 +/-0.19 percent/yr, or -3.6 percent over the time period February 1979 through April 1991. The data show that the column trend above 17 km is nearly zero in the tropics and increases towards the high latitudes with values of -0.6 percent/yr at 60 deg S and -0.35 percent/yr at 60 deg N. Both these results are in agreement with the recent TOMS results. The profile trend analyses show that the column ozone losses are occurring below 25 km, with most of the loss coming from the region between 17 and 20 km. Negative trend values on the order of -2 percent/yr are found at 17 km in midlatitudes.
Detecting trends in academic research from a citation network using network representation learning
Mori, Junichiro; Ochi, Masanao; Sakata, Ichiro
2018-01-01
Several network features and information retrieval methods have been proposed to elucidate the structure of citation networks and to detect important nodes. However, it is difficult to retrieve information related to trends in an academic field and to detect cutting-edge areas from the citation network. In this paper, we propose a novel framework that detects the trend as the growth direction of a citation network using network representation learning(NRL). We presume that the linear growth of citation network in latent space obtained by NRL is the result of the iterative edge additional process of a citation network. On APS datasets and papers of some domains of the Web of Science, we confirm the existence of trends by observing that an academic field grows in a specific direction linearly in latent space. Next, we calculate each node’s degree of trend-following as an indicator called the intrinsic publication year (IPY). As a result, there is a correlation between the indicator and the number of future citations. Furthermore, a word frequently used in the abstracts of cutting-edge papers (high-IPY paper) is likely to be used often in future publications. These results confirm the validity of the detected trend for predicting citation network growth. PMID:29782521
The Trend Odds Model for Ordinal Data‡
Capuano, Ana W.; Dawson, Jeffrey D.
2013-01-01
Ordinal data appear in a wide variety of scientific fields. These data are often analyzed using ordinal logistic regression models that assume proportional odds. When this assumption is not met, it may be possible to capture the lack of proportionality using a constrained structural relationship between the odds and the cut-points of the ordinal values (Peterson and Harrell, 1990). We consider a trend odds version of this constrained model, where the odds parameter increases or decreases in a monotonic manner across the cut-points. We demonstrate algebraically and graphically how this model is related to latent logistic, normal, and exponential distributions. In particular, we find that scale changes in these potential latent distributions are consistent with the trend odds assumption, with the logistic and exponential distributions having odds that increase in a linear or nearly linear fashion. We show how to fit this model using SAS Proc Nlmixed, and perform simulations under proportional odds and trend odds processes. We find that the added complexity of the trend odds model gives improved power over the proportional odds model when there are moderate to severe departures from proportionality. A hypothetical dataset is used to illustrate the interpretation of the trend odds model, and we apply this model to a Swine Influenza example where the proportional odds assumption appears to be violated. PMID:23225520
The trend odds model for ordinal data.
Capuano, Ana W; Dawson, Jeffrey D
2013-06-15
Ordinal data appear in a wide variety of scientific fields. These data are often analyzed using ordinal logistic regression models that assume proportional odds. When this assumption is not met, it may be possible to capture the lack of proportionality using a constrained structural relationship between the odds and the cut-points of the ordinal values. We consider a trend odds version of this constrained model, wherein the odds parameter increases or decreases in a monotonic manner across the cut-points. We demonstrate algebraically and graphically how this model is related to latent logistic, normal, and exponential distributions. In particular, we find that scale changes in these potential latent distributions are consistent with the trend odds assumption, with the logistic and exponential distributions having odds that increase in a linear or nearly linear fashion. We show how to fit this model using SAS Proc NLMIXED and perform simulations under proportional odds and trend odds processes. We find that the added complexity of the trend odds model gives improved power over the proportional odds model when there are moderate to severe departures from proportionality. A hypothetical data set is used to illustrate the interpretation of the trend odds model, and we apply this model to a swine influenza example wherein the proportional odds assumption appears to be violated. Copyright © 2012 John Wiley & Sons, Ltd.
NASA Astrophysics Data System (ADS)
Xu, Yu; Xu, Youpeng; Wang, Yuefeng; Wu, Lei; Li, Guang; Song, Song
2017-11-01
Reference crop evapotranspiration (ETo) is one of the most important links in hydrologic circulation and greatly affects regional agricultural production and water resource management. Its variation has drawn more and more attention in the context of global warming. We used the Penman-Monteith method of the Food and Agriculture Organization, based on meteorological factors such as air temperature, sunshine duration, wind speed, and relative humidity to calculate the ETo over 46 meteorological stations located in the Yangtze River Delta, eastern China, from 1957 to 2014. The spatial distributions and temporal trends in ETo were analyzed based on the modified Mann-Kendall trend test and linear regression method, while ArcGIS software was employed to produce the distribution maps. The multiple stepwise regression method was applied in the analysis of the meteorological variable time series to identify the causes of any observed trends in ETo. The results indicated that annual ETo showed an obvious spatial pattern of higher values in the north than in the south. Annual increasing trends were found at 34 meteorological stations (73.91 % of the total), which were mainly located in the southeast. Among them, 12 (26.09 % of the total) stations showed significant trends. We saw a dominance of increasing trends in the monthly ETo except for January, February, and August. The high value zone of monthly ETo appeared in the northwest from February to June, mid-south area from July to August, and southeast coastal area from September to January. The research period was divided into two stages—stage I (1957-1989) and stage II (1990-2014)—to investigate the long-term temporal ETo variation. In stage I, almost 85 % of the total stations experienced decreasing trends, while more than half of the meteorological stations showed significant increasing trends in annual ETo during stage II except in February and September. Relative humidity, wind speed, and sunshine duration were identified as the most dominant meteorological variables influencing annual ETo changes. The results are expected to assist water resource managers and policy makers in making better planning decisions in the research region.
Linear extension rates of massive corals from the Dry Tortugas National Park (DRTO), Florida
Muslic, Adis; Flannery, Jennifer A.; Reich, Christopher D.; Umberger, Daniel K.; Smoak, Joseph M.; Poore, Richard Z.
2013-01-01
Colonies of three coral species, Montastraea faveolata, Diploria strigosa, and Siderastrea siderea, located in the Dry Tortugas National Park (DRTO), Florida, were sampled and analyzed to evaluate annual linear extension rates. Montastraea faveolata had the highest average linear extension and variability in (DRTO: C2 = 0.67 centimeters/year (cm yr-1) ± 0.04, B3 = 0.85 cm yr-1 ± 0.07), followed by D. strigosa (DRTO: C1 = 0.73 cm yr-1 ± 0.04; MK = 0.59 cm yr-1 ± 0.06) and S. siderea (DRTO: A1 = 0.41 cm yr-1 ± 0.03). Intercolony comparison of M. faveolata from DRTO yielded a significant correlation (r = 0.34, df = 67, P = 0.005) and similar long-term patterns. DRTO S. siderea core A1 showed an overall increasing trend (r = 0.61, df = 119, P < 0.0001) in extension rates that correlated significantly with International Comprehensive Ocean/Atmosphere Data Set annual sea-surface temperature (r = 0.42, df = 115, P < 0.0001) and an air temperature record from Key West (r = 0.37, df = 111, P < 0.0001). In conclusion, annual linear extension rates are species specific and potentially influence by long-term variability in sea-surface temperature.
Lifestyle and Depression among Hong Kong Nurses.
Cheung, Teris; Yip, Paul S F
2016-01-16
Recent longitudinal data suggest a close association between depression and lifestyle. Little work to date has estimated the prevalence of depression in the nursing workforce in China, nor considered what lifestyle factors might be correlated with it-a gap filled by the present study. The study's web-based cross-sectional survey solicited data from qualified nurses aged between 21 and 65 registered with the Hong Kong Nursing Council. The Depression, Anxiety and Stress Scale 21 was used to measure 850 nurses for depression, anxiety and symptoms of stress; a generalized linear regression model examined associations between lifestyle factors and depression. Mean depression symptom scores show a downward linear trend for male and female participants. Gender and age, however, did not emerge as significant predictors of depression. Three lifestyles factors (sleep, entertainment and hobbies) showed a significant association with depression. Nurses should make therapeutic lifestyle changes to improve their work-life balance and safeguard their functioning at work and personal well-being.
Lifestyle and Depression among Hong Kong Nurses
Cheung, Teris; Yip, Paul S.F.
2016-01-01
Recent longitudinal data suggest a close association between depression and lifestyle. Little work to date has estimated the prevalence of depression in the nursing workforce in China, nor considered what lifestyle factors might be correlated with it—a gap filled by the present study. The study’s web-based cross-sectional survey solicited data from qualified nurses aged between 21 and 65 registered with the Hong Kong Nursing Council. The Depression, Anxiety and Stress Scale 21 was used to measure 850 nurses for depression, anxiety and symptoms of stress; a generalized linear regression model examined associations between lifestyle factors and depression. Mean depression symptom scores show a downward linear trend for male and female participants. Gender and age, however, did not emerge as significant predictors of depression. Three lifestyles factors (sleep, entertainment and hobbies) showed a significant association with depression. Nurses should make therapeutic lifestyle changes to improve their work-life balance and safeguard their functioning at work and personal well-being. PMID:26784216
A phenomenological biological dose model for proton therapy based on linear energy transfer spectra.
Rørvik, Eivind; Thörnqvist, Sara; Stokkevåg, Camilla H; Dahle, Tordis J; Fjaera, Lars Fredrik; Ytre-Hauge, Kristian S
2017-06-01
The relative biological effectiveness (RBE) of protons varies with the radiation quality, quantified by the linear energy transfer (LET). Most phenomenological models employ a linear dependency of the dose-averaged LET (LET d ) to calculate the biological dose. However, several experiments have indicated a possible non-linear trend. Our aim was to investigate if biological dose models including non-linear LET dependencies should be considered, by introducing a LET spectrum based dose model. The RBE-LET relationship was investigated by fitting of polynomials from 1st to 5th degree to a database of 85 data points from aerobic in vitro experiments. We included both unweighted and weighted regression, the latter taking into account experimental uncertainties. Statistical testing was performed to decide whether higher degree polynomials provided better fits to the data as compared to lower degrees. The newly developed models were compared to three published LET d based models for a simulated spread out Bragg peak (SOBP) scenario. The statistical analysis of the weighted regression analysis favored a non-linear RBE-LET relationship, with the quartic polynomial found to best represent the experimental data (P = 0.010). The results of the unweighted regression analysis were on the borderline of statistical significance for non-linear functions (P = 0.053), and with the current database a linear dependency could not be rejected. For the SOBP scenario, the weighted non-linear model estimated a similar mean RBE value (1.14) compared to the three established models (1.13-1.17). The unweighted model calculated a considerably higher RBE value (1.22). The analysis indicated that non-linear models could give a better representation of the RBE-LET relationship. However, this is not decisive, as inclusion of the experimental uncertainties in the regression analysis had a significant impact on the determination and ranking of the models. As differences between the models were observed for the SOBP scenario, both non-linear LET spectrum- and linear LET d based models should be further evaluated in clinically realistic scenarios. © 2017 American Association of Physicists in Medicine.
NASA Astrophysics Data System (ADS)
Sridhar, M.; Ramesh Babu, V.; Markandeyulu, A.; Raju, B. V. S. N.; Chaturvedi, A. K.; Roy, M. K.
2017-08-01
We constrained the geological framework over polydeformed Paleoproterozoic Sonakhan Greenstone Belt and addressed the tectonic evolution of Singhora basin in the fringes of Bastar Craton, central India by utilizing aeromagnetic data interpretation, 2.5D forward modelling and 3D magnetic susceptibility inversions. The Sonakhan Greenstone Belt exposes volcano-sedimentary sequences of the Sonakhan Group within NNW-SSE to NW-SE trending linear belts surrounded by granite gneisses, which are unconformably overlain by sedimentary rocks of Chhattisgarh Basin. The orientations of aeromagnetic anomalies are coincident with geological trends and appear to correlate with lithology and geologic structure. Regional magnetic anomalies and lineaments reveal both NNW-SSE and NE-SW trends. Prominent E-W trending linear, high amplitude magnetic anomalies are interpreted as the Trans-Chhattisgarh Aeromagnetic Lineament (TCAL). NW-SE trending aeromagnetic signatures related to Sonakhan Greenstone Belt extends below the Singhora sedimentary rocks and forms the basement in the west. The analysis suggests that TCAL is a block fault with northern block down-thrown and affected the basement rocks comprising the Sonakhan Greenstone Belt and Samblapur Granitoids. The episode of faulting represented by the TCAL is pre-Singhora sedimentation and played a vital role in basin evolution. The basement configuration image generated by estimates of depth to magnetic basement suggests a complex pattern of NNE-SSW to NE-SW trending depressions separated by a linear N-S trending basement ridge. It is inferred from the 3D magnetic susceptibility inversion that the thickness of sediments is more towards the eastern basin margin and the N-S ridge is a manifestation of post sedimentary faulting. Results of 2.5D modelling of a WNW-ESE profile across the Singhora Basin combined with results from 3D inversion suggest suggests the basin subsidence was controlled by NE-SW trending regional faults in an active system. The basin geometry evolved by E-W block faulting overprinted by NE-SW trending pre- to syn-depositional normal faults generating NE-SW depression, which are affected by N-S trend post-sedimentary faulting. Though the present work relates the basin evolution with the initiation of rift basin, it warrants further work to establish the deformation within the basin pertaining to the proximal thrust and uplift along the craton fringe.
Wise, Daniel R.; Rinella, Frank A.; Rinella, Joseph F.; Fuhrer, Greg J.; Embrey, Sandra S.; Clark, Gregory M.; Schwarz, Gregory E.; Sobieszczyk, Steven
2007-01-01
This study focused on three areas that might be of interest to water-quality managers in the Pacific Northwest: (1) annual loads of total nitrogen (TN), total phosphorus (TP) and suspended sediment (SS) transported through the Columbia River and Puget Sound Basins, (2) annual yields of TN, TP, and SS relative to differences in landscape and climatic conditions between subbasin catchments (drainage basins), and (3) trends in TN, TP, and SS concentrations and loads in comparison to changes in landscape and climatic conditions in the catchments. During water year 2000, an average streamflow year in the Pacific Northwest, the Columbia River discharged about 570,000 pounds per day of TN, about 55,000 pounds per day of TP, and about 14,000 tons per day of SS to the Pacific Ocean. The Snake, Yakima, Deschutes, and Willamette Rivers contributed most of the load discharged to the Columbia River. Point-source nutrient loads to the catchments (almost exclusively from municipal wastewater treatment plants) generally were a small percentage of the total in-stream nutrient loads; however, in some reaches of the Spokane, Boise, Walla Walla, and Willamette River Basins, point sources were responsible for much of the annual in-stream nutrient load. Point-source nutrient loads generally were a small percentage of the total catchment nutrient loads compared to nonpoint sources, except for a few catchments where point-source loads comprised as much as 30 percent of the TN load and as much as 80 percent of the TP load. The annual TN and TP loads from point sources discharging directly to the Puget Sound were about equal to the annual loads from eight major tributaries. Yields of TN, TP, and SS generally were greater in catchments west of the Cascade Range. A multiple linear regression analysis showed that TN yields were significantly (p < 0.05) and positively related to precipitation, atmospheric nitrogen load, fertilizer and manure load, and point-source load, and were negatively related to average slope. TP yields were significantly related positively to precipitation, and point-source load and SS yields were significantly related positively to precipitation. Forty-eight percent of the available monitoring sites for TN had significant trends in concentration (2 increasing, 19 decreasing), 32 percent of the available sites for TP had significant trends in concentration (7 increasing, 9 decreasing), and 40 percent of the available sites for SS had significant trends in concentration (4 increasing, 15 decreasing). The trends in load followed a similar pattern, but with fewer sites showing significant trends. The results from this study indicate that inputs from nonpoint sources of nutrients probably have decreased over time in many of the catchments. Despite the generally small contribution of point-source nutrient loads, they still may have been partially responsible for the significant decreasing trends for nutrients at sites where the total point-source nutrient loads to the catchments equaled a substantial proportion of the in-stream load.
Positive impact of the participation in the ENCHANTED trial in reducing Door-to-Needle Time.
Yang, Jie; Wang, Xia; Yu, Jian Ping; Hang, Jing; Lavados, Pablo; Robinson, Thompson; Arima, Hisatomi; Lindley, Richard I; Anderson, Craig S; Chalmers, John
2017-10-26
Door-to-needle time (DNT) is a key performance indicator for efficient use of intravenous thrombolysis in acute ischemic stroke (AIS). We aimed to determine whether DNT improved over time in the Enhanced Control of Hypertension and Acute Stroke Study (ENCHANTED) and the clinical predictors of DNT. Temporal trends in DNT were assessed across fourths of time since activation of study centers using generalized linear model. Predictors of long DNT (>60 min) were determined in logistic regression models. Overall mean DNT (min) was 71.8 (95% confidence interval [CI] 70.4-73.2), but decreased significantly over time (fourths): 77.9 (74.9-80.9), 69.3 (66.7-72.0), 69.1 (66.5-71.8) and 71.4 (68.7-74.2) (P for trend, 0.003). The reduction in DNT was particularly marked in China (P for trend, 0.001), but was not significant across the other participating countries (P for trend, 0.065). Independent predictors of long DNT were recruitment from China, short onset-to-door time, lower numbers of patients treated per center, higher diastolic blood pressure, off-hour admission, and absence of proximal clot occlusion. DNT in ENCHANTED declined progressively during the trial, especially in China. However, DNT in China is still longer than the key performance parameter of ≤60 minutes recommended in guidelines. Effective national programs are needed to improve DNT in China.
Modified visual field trend analysis.
De Moraes, Carlos Gustavo V; Ritch, Robert; Tello, Celso; Liebmann, Jeffrey M
2011-01-01
Visual field trend analysis can be influenced by outlying values that may disproportionately affect estimation of the rate of change. We tested a modified approach to visual field trend analysis to minimize this problem. Automated pointwise linear regression (PLR) was used in glaucoma patients with ≥13 SITA-Standard 24-2 VF tests in either eye. In the control group (Group A), conventional PLR using the entire set of VF tests was carried out. In the other 3 groups (study groups), a truncated analysis was done using only the first and last 3 (Group B), first and last 4 (Group C), or first and last 5 (Group D) VF tests. We compared the global slopes (dB/y), number of eyes experiencing significant progression, and significant improvement between groups. Ninety eyes of 90 patients were evaluated. The mean number±SD of VF tests was 15.7±2.6, spanning 7.8±1.7 years. The study groups showed similar global rates of VF change as the control group (Group A=-0.48±0.5, Group B=-0.48±0.6, Group C=-0.48±0.6, Group D=-0.48±0.5 dB/y, P>0.05), and a similar number of eyes reaching a progression endpoint (Group A=53, Group B=52, Group C=49, Group D=53, P>0.05). However, Group B showed fewer eyes presenting VF improvement (false-positives). The modified VF trend-analysis showed greater specificity than conventional PLR in a population with glaucoma.
NASA Astrophysics Data System (ADS)
Bai, Kaixu; Chang, Ni-Bin; Shi, Runhe; Yu, Huijia; Gao, Wei
2017-07-01
A four-step adaptive ozone trend estimation scheme is proposed by integrating multivariate linear regression (MLR) and ensemble empirical mode decomposition (EEMD) to analyze the long-term variability of total column ozone from a set of four observational and reanalysis total ozone data sets, including the rarely explored ERA-Interim total ozone reanalysis, from 1979 to 2009. Consistency among the four data sets was first assessed, indicating a mean relative difference of 1% and root-mean-square error around 2% on average, with respect to collocated ground-based total ozone observations. Nevertheless, large drifts with significant spatiotemporal inhomogeneity were diagnosed in ERA-Interim after 1995. To emphasize long-term trends, natural ozone variations associated with the solar cycle, quasi-biennial oscillation, volcanic aerosols, and El Niño-Southern Oscillation were modeled with MLR and then removed from each total ozone record, respectively, before performing EEMD analyses. The resulting rates of change estimated from the proposed scheme captured the long-term ozone variability well, with an inflection time of 2000 clearly detected. The positive rates of change after 2000 suggest that the ozone layer seems to be on a healing path, but the results are still inadequate to conclude an actual recovery of the ozone layer, and more observational evidence is needed. Further investigations suggest that biases embedded in total ozone records may significantly impact ozone trend estimations by resulting in large uncertainty or even negative rates of change after 2000.
NASA Astrophysics Data System (ADS)
Yu, Shuang; Xia, Jiangjiang; Yan, Zhongwei; Yang, Kun
2018-01-01
The variation of the vegetation growing season in the Three-Rivers Headwater Region of the Tibetan Plateau has recently become a controversial topic. One issue is that the estimated local trend in the start of the vegetation growing season (SOS) based on remote sensing data is easily affected by outliers because this data series is short. In this study, we determine that the spring minimum temperature is the most influential factor for SOS. The significant negative linear relationship between the two variables in the region is evaluated using Moderate Resolution Imaging Spectroradiometer-Normalized Difference Vegetation Index data for 2000-13. We then reconstruct the SOS time series based on the temperature data for 1960-2013. The regional mean SOS shows an advancing trend of 1.42 d (10 yr)-1 during 1960-2013, with the SOS occurring on the 160th and 151st days in 1960 and 2013, respectively. The advancing trend enhances to 6.04 d (10 yr)-1 during the past 14 years. The spatiotemporal variations of the reconstructed SOS data are similar to those deduced from remote sensing data during the past 14 years. The latter exhibit an even larger regional mean trend of SOS [7.98 d (10 yr-1)] during 2000-13. The Arctic Oscillation is found to have significantly influenced the changing SOS, especially for the eastern part of the region, during 2000-13.
NASA Astrophysics Data System (ADS)
Liu, S.; Tian, H.; Wang, X.; Li, H.; He, Y.
2018-04-01
Vegetation plays a leading role in ecosystems. Plant communities are the main components of ecosystems. Green plants in ecosystems are the primary producers, and they provide the living organic matter for the survival of other organisms. The dynamics of most landscapes are driven by both natural processes and human activities. In this study, the growing season GIMMS NDVI3g and climatic data were used to analyse the vegetation trends and drivers in Beijing-Tianjin-Hebei region from 1982 to 2013. Result shows that, the vegetation in Beijing-Tianjin-Hebei region shows overall restoration and partial degradation trend. The significant restoration region accounts for 61.5 % of Beijing-Tianjin-Hebei region, while the significant degradation region accounts for 2.1 %. The dominant climatic factor for time series NDVI were analyzed using the multi-linear regression model. Vegetation growth in 17.9 % of Beijing-Tianjin-Hebei region is dominated by temperature, 35.5 % is dominated by precipitation, and 11.68 % is dominated by solar radiance. Human activities play important role for vegetation restoration in Beijing-Tianjin-Hebei Region, where the large scale forest restoration programs are the main human activities, such as the three-north shelterbelt construction project, Beijing-Tianjin-Hebei sandstorm source control project and grain for green projects.
Pacing patterns in competitive rowing adopted in different race categories.
Muehlbauer, Thomas; Melges, Thomas
2011-05-01
Data from 7 World Rowing Championships between 2001 and 2009 were analyzed to determine the time distribution during 2,000-m heavyweight races (from 500-m quarter times) and to assess whether pacing patterns differ between boat classes (single vs. team boats) and qualifying rounds (heats vs. finals). Analyses of variance with repeated measures on quarter times revealed that pacing patterns in heat races were better described (i.e., higher amount of variance explained) by a linear trend line with a positive slope (women: η² = 0.76, men: η² = 0.68) but followed a quadratic trend line (parabolic-shaped pattern) during finals (women: η² = 0.81, men: η² = 0.60). Not using a spurt at the end of the heat races may indicate an attempt to conserve energy for subsequent rounds or reflect reduced effort made by losing crews or both aspects. In single boats, the pacing pattern was better represented by a linear trend line with a positive slope (women: η² = 0.76, men: η² = 0.68), but the amount of variance explained was virtually the same for both the linear and the quadratic trend component in team boats. The absence of a final spurt in single boat races suggests that the physiological status of the athlete plays an important role to control the timing and rate of decline in rowing speed.
Recurrent jellyfish blooms are a consequence of global oscillations.
Condon, Robert H; Duarte, Carlos M; Pitt, Kylie A; Robinson, Kelly L; Lucas, Cathy H; Sutherland, Kelly R; Mianzan, Hermes W; Bogeberg, Molly; Purcell, Jennifer E; Decker, Mary Beth; Uye, Shin-ichi; Madin, Laurence P; Brodeur, Richard D; Haddock, Steven H D; Malej, Alenka; Parry, Gregory D; Eriksen, Elena; Quiñones, Javier; Acha, Marcelo; Harvey, Michel; Arthur, James M; Graham, William M
2013-01-15
A perceived recent increase in global jellyfish abundance has been portrayed as a symptom of degraded oceans. This perception is based primarily on a few case studies and anecdotal evidence, but a formal analysis of global temporal trends in jellyfish populations has been missing. Here, we analyze all available long-term datasets on changes in jellyfish abundance across multiple coastal stations, using linear and logistic mixed models and effect-size analysis to show that there is no robust evidence for a global increase in jellyfish. Although there has been a small linear increase in jellyfish since the 1970s, this trend was unsubstantiated by effect-size analysis that showed no difference in the proportion of increasing vs. decreasing jellyfish populations over all time periods examined. Rather, the strongest nonrandom trend indicated jellyfish populations undergo larger, worldwide oscillations with an approximate 20-y periodicity, including a rising phase during the 1990s that contributed to the perception of a global increase in jellyfish abundance. Sustained monitoring is required over the next decade to elucidate with statistical confidence whether the weak increasing linear trend in jellyfish after 1970 is an actual shift in the baseline or part of an oscillation. Irrespective of the nature of increase, given the potential damage posed by jellyfish blooms to fisheries, tourism, and other human industries, our findings foretell recurrent phases of rise and fall in jellyfish populations that society should be prepared to face.
Night-time lights: A global, long term look at links to socio-economic trends
Zavala-Araiza, Daniel; Wagner, Gernot
2017-01-01
We use a parallelized spatial analytics platform to process the twenty-one year totality of the longest-running time series of night-time lights data—the Defense Meteorological Satellite Program (DMSP) dataset—surpassing the narrower scope of prior studies to assess changes in area lit of countries globally. Doing so allows a retrospective look at the global, long-term relationships between night-time lights and a series of socio-economic indicators. We find the strongest correlations with electricity consumption, CO2 emissions, and GDP, followed by population, CH4 emissions, N2O emissions, poverty (inverse) and F-gas emissions. Relating area lit to electricity consumption shows that while a basic linear model provides a good statistical fit, regional and temporal trends are found to have a significant impact. PMID:28346500
NASA Technical Reports Server (NTRS)
Philipson, W. R. (Principal Investigator); Liang, T.; Philpot, W. D.
1983-01-01
Field spectroradiometric and airborne multispectral scanner data were related to vineyard yield and other agronomic variables in an attempt to determine the optimum wavelengths for yield prediction modeling. Reflections between vine canopy reflectance and several management practices were also considered. Spectral analysis of test vines found that, although some correlations with vine yield were significant, they were inadequate for producing a yield prediction model. The findings also indicate that the vines examined through the field spectroradiometers were not truly representative. Geologic linears identified from aerial photographys, LANDSAT images, and maps were compared to gas well locations in three New York' counties. Correlations were found between the dominant trends in regional liners and gas field boundaries and trends. Other projects being conducted under the grant include determining vegetable acreage in mucklands, site selection for windmills, spectral effects of sulfur dioxide, and screening tomato seedlings for salt tolerance.
NASA Astrophysics Data System (ADS)
Lopez, B.; Baran, N.; Bourgine, B.; Ratheau, D.
2009-04-01
The European Union (EU) has adopted directives requiring that Member States take measures to reach a "good" chemical status of water resources by the year 2015 (Water Framework Directive: WFD). Alongside, the Nitrates Directives (91/676/EEC) aims at controlling nitrogen pollution and requires Member States to identify groundwaters that contain more than 50 mg NO3 L-1 or could exceed this limit if preventive measures are not taken. In order to achieve these environmental objectives in the Loire-Brittany river basin, or to justify the non achievement of these objectives, a large dataset of nitrate concentrations (117.056 raw data distributed on 7.341 time-series) and water table level time-series (1.371.655 data distributed on 511 piezometers) is analysed from 1945 to 2007. The 156.700 sq km Loire-Brittany river basin shows various hydrogeological contexts, ranging from sedimentary aquifers to basement ones, with a few volcanic-rock aquifers. The knowledge of the evolution of agricultural practices is important in such a study and, even if this information is not locally available, agricultural practices have globally changed since the 1991 Nitrates Directives. The detailed dataset available for the Loire-Brittany basin aquifers is used to evaluate tools and to propose efficient methodologies for identifying and quantifying past and current trends in nitrate concentrations. Therefore, the challenge of this study is to propose a global and integrated approach which allows nitrate trend identifications for the whole Loire-Brittany river basin. The temporal piezometric behaviour of each aquifer is defined using geostatistical analyse of water table level time-series. This method requires the calculation of an experimental temporal variogram that can be fitted with a theoretical model valid for a large time range. Identification of contrasted behaviours (short term, annual or pluriannual water table fluctuations) allows a systematic classification of the Loire-Brittany superficial aquifers. The nitrate dataset shows too many irregularities to employ traditional time-series approaches such as linear regression trend tests. The non-parametric Mann-Kendall (MK) test is a robust statistical trend detection test that does not require verification of the normality of the dataset (Aguilar et al, 2007). Moreover, this test seems appropriate since it is less sensitive to missing or outlier data than a simple linear regression test. As the MK test can only detect monotonic trends, and as already done by Stuart et al., (2007) and Broers and Van der Grift (2004), the trend analyses are decennially partitioned in order to identify possible trend reversals for the studied period for each observation point. The trend identification is then spatialized by the use of the Kendall Regional (KR) test on homogenous zones characterized by their geology, their agricultural practices and their piezometric behaviour. The KR test, previously used by Frans and Helsel (2005) in the Columbia Basin Ground Water context, is quite similar to the MK test and consists of the creation of virtual regional boreholes using networks of boreholes located in the homogenous zones. This test allows the identification of regional monotonic trends, even in the zones where nitrate time-series are too small to detect significant trend per observation point. The MK test results show significant upward trends in nitrate concentrations in the Loire-Brittany superficial aquifers when the test is computed on the 1945-2007 period. However, the decennial MK test shows different behaviours at smaller time scale. Some zones are characterized by a constant and significant increase in nitrate concentrations since 1945 (North-East of Brittany, North of Beauce) whereas others show a trend reversal (South of Brittany, Callovo-Oxfordian marls between Le Mans and Alençon, under covered Jurassic limestone around Poitiers). Furthermore, some rare zones show an increase in nitrate concentrations that follow a significant downward trend period (Orléans). In the nineties, a transition period may have occurred with a higher proportion of upward than downward trends (82 % against 7 % respectively) for the 1980-1990 period and a lower proportion of upward than downward trends for the 2000-2007 period (37 % against 51 % respectively). Combined with the analyse of the current groundwater nitrate concentrations, the KR test reveals zones where trends in nitrate concentrations have been significantly raising with high nitrate current mean values (> 50 mg NO3 L-1). On the other hand, some zones show a significant regional downward trend since 1995 and low current nitrate concentrations (< 20 mg NO3 L-1). Causes of trend reversals cannot be determined by the MK and KR statistical trend analyses, but the cross analyse of nitrate and water table level time-series gives a hint of a positive correlation between these two variables. Evolution of nitrate concentrations in superficial aquifers may thus depend on a combined effect of changes in both agricultural practices and evolution of water table levels linked with climatic context. References Aguilar J.B., Orban P., Dassargues A., Brouyère S., (2007) - Identification of groundwater quality trends in a chalk aquifer threatened by intensive agriculture in Belgium. Hydrogeology journal 15: 1615-1627. Broers H.P., van der Grift B., (2004) - Regional monitoring of temporal changes in groundwater quality. Journal of hydrology 296: 192-220. Frans L.M., Helsel D.R. (2005) - Evaluating regional trends in ground water nitrate concentrations of the Columbia Basin Ground Water management Area, Washington. U.S. Geological Survey Scientific Investigations Report 2005-5078, 7p. Stuart M.E., Chilton P.J., Kiniiburgh D.G., Cooper D.M., (2007) - Screening for long-term trends in groundwater nitrate monitoring data. Quaterly Journal of Engineering Geology and Hydrogeology, 40: 361-376. Funding The study was funded by the Loire-Brittany River Basin Agency and from proper BRGM funds.
NASA Technical Reports Server (NTRS)
Remsberg, Ellis E.
2009-01-01
Fourteen-year time series of mesospheric and upper stratospheric temperatures from the Halogen Occultation Experiment (HALOE) are analyzed and reported. The data have been binned according to ten-degree wide latitude zones from 40S to 40N and at 10 altitudes from 43 to 80 km-a total of 90 separate time series. Multiple linear regression (MLR) analysis techniques have been applied to those time series. This study focuses on resolving their 11-yr solar cycle (or SC-like) responses and their linear trend terms. Findings for T(z) from HALOE are compared directly with published results from ground-based Rayleigh lidar and rocketsonde measurements. SC-like responses from HALOE compare well with those from lidar station data at low latitudes. The cooling trends from HALOE also agree reasonably well with those from the lidar data for the concurrent decade. Cooling trends of the lower mesosphere from HALOE are not as large as those from rocketsondes and from lidar station time series of the previous two decades, presumably because the changes in the upper stratospheric ozone were near zero during the HALOE time period and did not affect those trends.
Schut, Antonius G. T.; Ivits, Eva; Conijn, Jacob G.; ten Brink, Ben; Fensholt, Rasmus
2015-01-01
Detailed understanding of a possible decoupling between climatic drivers of plant productivity and the response of ecosystems vegetation is required. We compared trends in six NDVI metrics (1982–2010) derived from the GIMMS3g dataset with modelled biomass productivity and assessed uncertainty in trend estimates. Annual total biomass weight (TBW) was calculated with the LINPAC model. Trends were determined using a simple linear regression, a Thiel-Sen medium slope and a piecewise regression (PWR) with two segments. Values of NDVI metrics were related to Net Primary Production (MODIS-NPP) and TBW per biome and land-use type. The simple linear and Thiel-Sen trends did not differ much whereas PWR increased the fraction of explained variation, depending on the NDVI metric considered. A positive trend in TBW indicating more favorable climatic conditions was found for 24% of pixels on land, and for 5% a negative trend. A decoupled trend, indicating positive TBW trends and monotonic negative or segmented and negative NDVI trends, was observed for 17–36% of all productive areas depending on the NDVI metric used. For only 1–2% of all pixels in productive areas, a diverging and greening trend was found despite a strong negative trend in TBW. The choice of NDVI metric used strongly affected outcomes on regional scales and differences in the fraction of explained variation in MODIS-NPP between biomes were large, and a combination of NDVI metrics is recommended for global studies. We have found an increasing difference between trends in climatic drivers and observed NDVI for large parts of the globe. Our findings suggest that future scenarios must consider impacts of constraints on plant growth such as extremes in weather and nutrient availability to predict changes in NPP and CO2 sequestration capacity. PMID:26466347
Sivasubramaniam, Vinothan; Patel, Hitesh C; Ozdemir, Baris A; Papadopoulos, Marios C
2015-12-15
Low back pain (LBP), from degenerative lumbar spine disease, represents a significant burden on healthcare resources. Studies worldwide report trends attributable to their country's specific demographics and healthcare system. Considering England's specific medico-socioeconomic conditions, we investigate recent trends in hospital admissions and procedures for LBP, and discuss the implications for the allocation of healthcare resources. Retrospective cohort study using Hospital Episode Statistics data relating to degenerative lumbar spine disease in England, between 1999 and 2013. Regression models were used to analyse trends. Trends in the number of admissions and procedures for LBP, mean patient age, gender and length of stay. Hospital admissions and procedures have increased significantly over the study period, from 127.09 to 216.16 and from 24.5 to 48.83 per 100,000, respectively, (p<0.001). The increase was most marked in the oldest age groups with a 1.9 and 2.33-fold increase in admissions for patients aged 60-74 and ≥ 75 years, respectively, and a 2.8-fold increase in procedures for those aged ≥ 60 years. Trends in hospital admissions were characterised by a widening gender gap, increasing mean patient age, and decreasing mean hospital stay (p<0.001). Trends in procedures were characterised by a narrowing gender gap, increasing mean patient age (p=0.014) and decreasing mean hospital stay (p<0.001). Linear regression models estimate that each hospital admission translates to 0.27 procedures, per 100,000 (95% CI 0.25 to 0.30, r 0.99, p<0.001; r, Pearson's correlation coefficient). Hospital admissions are increasing at 3.5 times the rate of surgical procedures (regression gradient 7.63 vs 2.18 per 100,000/year). LBP represents a significant and increasing workload for hospitals in England. These trends demonstrate an increasing demand for specialists involved in the surgical and non-surgical management of this disease, and highlight the need for services capable of dealing with the increased comorbidity burden associated with an ageing patient group. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
Niemuth, Neal D.; Fleming, Kathleen K.; Reynolds, Ronald E.
2014-01-01
The Prairie Pothole Region (PPR) is the most important waterfowl production area in North America. However, waterfowl populations there are predicted to decline because of climate-related drying of wetlands. Consequently, changes in the geographic focus of PPR waterfowl conservation have been recommended, which could have long-lasting and costly impacts. We used a 40-year dataset of pond counts collected in the PPR to test hypotheses about climate-related drying. We assessed May (1974–2013) and July (1974–2003) pond numbers in 20 waterfowl survey strata to determine if trends in pond numbers were consistent with predictions of drying. We also assessed trends in precipitation and temperature for the 20 strata and developed models describing May pond numbers from 1974 through 2010 as a function of precipitation, temperature, the previous year’s pond numbers, and location. None of the 20 strata showed significant declines in May pond numbers, although seven strata showed increases over time. July pond numbers declined significantly in one stratum, and increased in seven strata. An index to hydroperiod showed significant increasing trends in three strata, and no strata had decreasing trends. Precipitation increased significantly in two strata and decreased in two from 1974 to 2010; no strata showed significant changes in temperature. The best linear model described pond numbers within all strata as a function of precipitation, temperature, the previous year’s pond numbers, and the latitude and longitude of the stratum, and explained 62% of annual variation in pond numbers. We hypothesize that direct effects of climate change on prairie pothole wetlands and waterfowl may be overshadowed by indirect effects such as intensified land use and increased pressure to drain wetlands. We recommend that an adaptive, data-driven approach be used to resolve uncertainties regarding direct and indirect effects of climate change on prairie wetlands and waterfowl, and guide future conservation efforts. PMID:24937641
Niemuth, Neal D; Fleming, Kathleen K; Reynolds, Ronald E
2014-01-01
The Prairie Pothole Region (PPR) is the most important waterfowl production area in North America. However, waterfowl populations there are predicted to decline because of climate-related drying of wetlands. Consequently, changes in the geographic focus of PPR waterfowl conservation have been recommended, which could have long-lasting and costly impacts. We used a 40-year dataset of pond counts collected in the PPR to test hypotheses about climate-related drying. We assessed May (1974-2013) and July (1974-2003) pond numbers in 20 waterfowl survey strata to determine if trends in pond numbers were consistent with predictions of drying. We also assessed trends in precipitation and temperature for the 20 strata and developed models describing May pond numbers from 1974 through 2010 as a function of precipitation, temperature, the previous year's pond numbers, and location. None of the 20 strata showed significant declines in May pond numbers, although seven strata showed increases over time. July pond numbers declined significantly in one stratum, and increased in seven strata. An index to hydroperiod showed significant increasing trends in three strata, and no strata had decreasing trends. Precipitation increased significantly in two strata and decreased in two from 1974 to 2010; no strata showed significant changes in temperature. The best linear model described pond numbers within all strata as a function of precipitation, temperature, the previous year's pond numbers, and the latitude and longitude of the stratum, and explained 62% of annual variation in pond numbers. We hypothesize that direct effects of climate change on prairie pothole wetlands and waterfowl may be overshadowed by indirect effects such as intensified land use and increased pressure to drain wetlands. We recommend that an adaptive, data-driven approach be used to resolve uncertainties regarding direct and indirect effects of climate change on prairie wetlands and waterfowl, and guide future conservation efforts.
Heydari, Gholamreza; Ebn Ahmady, Arezoo; Lando, Harry A; Chamyani, Fahimeh; Masjedi, Mohammad Reza; Shadmehr, Mohammad B; Fadaizadeh, Lida; Chaibakhsh, Samira
2016-09-01
Evidence from the USA and elsewhere has linked smoking depictions in movies with youth smoking initiation. Prior research has not focused on depictions in films produced in the Middle East, however. We reviewed the 10 most commercially successful Iranian films released each year over three decades (1982-2011) to determine trends in depictions of tobacco use over time. Each movie was reviewed in its entirety, and depictions of smoking were recorded and classified as direct (characters holding or using tobacco products) and indirect (tobacco products appearing in the frame, but not being used). Time trends in average duration of direct, indirect and total smoking depictions were analysed using linear regression and Cohen's κ coefficient. The mean duration of tobacco depictions in the most commercially successful Iranian films fluctuated yearly over the 3 decades, but with an overall significant upward trend (p<0.005). The proportion of movies depicting tobacco consumption during the three decades was 36% (1982-1991), 60% (1992-2001) and 74% (2002-2011), respectively. The average proportion of total movie time for these depictions (0.75%, 1.41%, 2.08%) increased significantly (p<0.005) over the 3 decades as did the average duration of smoking depictions,(39.1, 67 and 99.3 s, respectively, p<0.005). The significant increase in the proportion of movies depicting tobacco consumption and in the duration of smoking depictions over the past 30 years underscores the need for increased regulation of the Iranian film industry to minimise this important source of influence on tobacco initiation in young people. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
Inpatient imaging utilization: trends of the past decade.
Shinagare, Atul B; Ip, Ivan K; Abbett, Sarah K; Hanson, Richard; Seltzer, Steven E; Khorasani, Ramin
2014-03-01
We have previously reported inpatient imaging utilization trends at our institution from fiscal year (FY) 1984 through FY 2002. In this study, we assessed the trends in imaging utilization for inpatients from FY 2003 through FY 2012. In this institutional review board-approved retrospective study performed at a 793-bed tertiary care academic institution, we reviewed imaging utilization in adult inpatients from October 1, 2002, through September 30, 2012 (FY 2003 through FY 2012), and recorded the gross number of imaging studies coded by modality (conventional [radiography and fluoroscopy], ultrasound, nuclear medicine, CT, and MRI) and associated relative value units (RVUs). We used linear regression to assess trends in number of imaging studies and RVUs per case-mix-adjusted admission (CMAA). The total number of imaging studies, as well as the number of CT, nuclear medicine, and conventional studies adjusted for case mix, decreased (p=0.02, p=0.0006, p=0.0008, and p=0.001, respectively); CT per CMAA increased until FY 2009 and then decreased through FY 2012. Utilization of ultrasound and MRI did not change significantly (p=0.15 and p=0.22, respectively). Unadjusted global RVUs increased until FY 2009 and then showed a slight decrease through FY 2012 (p=0.04), whereas RVUs per CMAA did not change significantly (p=0.18). After decades of continued rise, imaging utilization for inpatients significantly decreased by most measures between FY 2009 and FY 2012. Future studies to evaluate the contribution of various factors to this decline, including efforts to reduce inappropriate use of imaging and concerns about potential harms of radiation exposure, may be helpful in optimizing imaging utilization and resource planning.
NASA Astrophysics Data System (ADS)
Yoon, J.; von Hoyningen-Huene, W.; Kokhanovsky, A. A.; Vountas, M.; Burrows, J. P.
2011-08-01
Regular aerosol observations based on well-calibrated instruments have led to a better understanding of the aerosol radiative budget on Earth. In recent years, these instruments have played an important role in the determination of the increase of anthropogenic aerosols by means of long-term studies. Only few investigations regarding long-term trends of aerosol optical characteristics (e.g. Aerosol Optical Thickness (AOT) and Ångström Exponent (ÅE)) have been derived from ground-based observations. This paper aims to derive and discuss linear trends of AOT (440, 675, 870, and 1020 nm) and ÅE (440-870 nm) using AErosol RObotic NETwork (AERONET) spectral observations. Additionally, temporal trends of Coarse- and Fine-mode dominant AOTs (CAOT and FAOT) have been estimated by applying an aerosol classification based on accurate ÅE and Ångström Exponent Difference (ÅED). In order to take into account the fact that cloud disturbance is having a significant influence on the trend analysis of aerosols, we introduce a weighted least squares regression depending on two weights: (1) monthly standard deviation and (2) Number of Observations (NO) per month. Temporal increase of FAOTs prevails over regions dominated by emerging economy or slash-burn agriculture in East Asia and South Africa. On the other hand, insignificant or negative trends for FAOTs are detected over Western Europe and North America. Over desert regions, both increase and decrease of CAOTs are observed depending on meteorological conditions.
Analysis of childhood leukemia mortality trends in Brazil, from 1980 to 2010.
Silva, Franciane F; Zandonade, Eliana; Zouain-Figueiredo, Glaucia P
2014-01-01
Leukemias comprise the most common group of cancers in children and adolescents. Studies conducted in other countries and Brazil have observed a decrease in their mortality.This study aimed to evaluate the trend of mortality from leukemia in children under 19 years of age in Brazil, from 1980 to 2010. This was an ecological study, using retrospective time series data from the Mortality Information System, from 1980 to 2010. Calculations of mortality rates were performed, including gross, gender-specific, and age-based. For trend analysis, linear and semi-log regression models were used. The significance level was 5%. Mortality rates for lymphoid and myeloid leukemias presented a growth trend, with the exception of lymphoid leukemia among children under 4 years of age (percentage decrease: 1.21% annually), while in the sub-group "Other types of leukemia", a downward trend was observed. Overall, mortality from leukemia tended to increase for boys and girls, especially in the age groups 10-14 years (annual percentage increase of 1.23% for males and 1.28% for females) and 15-19 years (annual percentage increase of 1.40% for males and 1.62% for females). The results for leukemia generally corroborate the results of other similar studies. A detailed analysis by subgroup of leukemia, age, and gender revealed no trends shown in other studies, thus indicating special requirements for each variable in the analysis. Copyright © 2014 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.
Mohsena, Masuda; Goto, Rie; Mascie-Taylor, C G Nicholas
2017-03-01
The nutritional status of under-five-year-old children is a sensitive indicator of a country's health status as well as economic condition. The objectives of this study were to analyse trends in the nutritional status in Bangladeshi children over the period 1996-2007 and to examine the associations between nutritional and socioeconomic status variables. Bangladesh Demographic Health Surveys (BDHS) were the source of data, and a total of 16,278 children were examined. The Z-scores of the children were analysed as continuous as well as categorical variables (stunted, underweight and wasted). The socioeconomic status variables used were region, urban-rural residence, education and occupation of the parents, house type and household possession score. A series of General Linear Model and Sequential Linear and Binary Logistic Regression analyses were done to assess the relationship between demographic and socioeconomic variables and nutritional status. The trends of Z-scores were analysed by survey, as well as by child birth cohort. Region, house type, educational level of parents and household possession score showed significant associations with all three Z-scores of children after removing the effects of age, period of DHS and other explanatory variables in the model. No significant sex difference was observed between any of the Z-scores. There were improvements in mean WAZ and HAZ between 1996 and 2007 but deterioration in mean WHZ over this period. The obesity rate was below 2% in 2007, although the absolute numbers of obese children had nearly doubled in this 12-year period. Children from poorer households showed greater improvement than their better-off counterparts. The study reveals that over the years there has been substantial improvement in nutritional status of under-five children in Bangladesh and the main gains have been amongst the lower socioeconomic groups; it is also evident that malnutrition in Bangladesh is a multidimensional problem, like poverty itself, and warrants a proper policy mix and programme intervention.
Jarvis, Martin J; Feyerabend, Colin
2015-09-01
To examine changes in children's exposure to second-hand tobacco smoke in England since 1998. Repeated cross-sectional surveys of the general population in England. The Health Survey for England. A total of 37 038 children participating in surveys from 1998 to 2012, 13 327 of whom were aged 4-15 years, had available cotinine and were confirmed non-smokers. The proportion of children with smoking parents; the proportion of children living in homes reported to be smoke-free; the proportion of children with undetectable concentrations of cotinine; linear and quadratic trend estimates of geometric mean cotinine across years. By 2012, 87.3% of children lived in a home that was smoke-free {97.2% [95% confidence interval (CI) = 95.9-98.1] when parents were non-smokers, 61.3% (95% CI = 55.5-66.8) when one or both parents smoked}. A total of 68.6% (95% CI = 64.3-72.6%) of children had undetectable cotinine in 2012, up from 14.3% (95% CI = 12.7-16.0%) in 1998. There was a highly significant linear trend across years (with a small but significant quadratic term) to declining geometric mean cotinine in all children from 0.52 ng/ml (95% CI = 0.48-0.57) in 1998 to 0.11 ng/ml (95% CI = 0.10-0.12) in 2012. Children from routine/manual backgrounds were more exposed, but experienced similar gains across years to those from non-manual backgrounds. In England, children's exposure to second-hand smoke has declined by 79% since 1998, with continuing progress since smoke-free legislation in 2007. An emerging social norm in England has led to the adoption of smoke-free homes not only when parents are non-smokers, but also when they smoke. © 2015 Society for the Study of Addiction.
Stochastic approaches for time series forecasting of boron: a case study of Western Turkey.
Durdu, Omer Faruk
2010-10-01
In the present study, a seasonal and non-seasonal prediction of boron concentrations time series data for the period of 1996-2004 from Büyük Menderes river in western Turkey are addressed by means of linear stochastic models. The methodology presented here is to develop adequate linear stochastic models known as autoregressive integrated moving average (ARIMA) and multiplicative seasonal autoregressive integrated moving average (SARIMA) to predict boron content in the Büyük Menderes catchment. Initially, the Box-Whisker plots and Kendall's tau test are used to identify the trends during the study period. The measurements locations do not show significant overall trend in boron concentrations, though marginal increasing and decreasing trends are observed for certain periods at some locations. ARIMA modeling approach involves the following three steps: model identification, parameter estimation, and diagnostic checking. In the model identification step, considering the autocorrelation function (ACF) and partial autocorrelation function (PACF) results of boron data series, different ARIMA models are identified. The model gives the minimum Akaike information criterion (AIC) is selected as the best-fit model. The parameter estimation step indicates that the estimated model parameters are significantly different from zero. The diagnostic check step is applied to the residuals of the selected ARIMA models and the results indicate that the residuals are independent, normally distributed, and homoscadastic. For the model validation purposes, the predicted results using the best ARIMA models are compared to the observed data. The predicted data show reasonably good agreement with the actual data. The comparison of the mean and variance of 3-year (2002-2004) observed data vs predicted data from the selected best models show that the boron model from ARIMA modeling approaches could be used in a safe manner since the predicted values from these models preserve the basic statistics of observed data in terms of mean. The ARIMA modeling approach is recommended for predicting boron concentration series of a river.
López-Campos, Jose L; Ruiz-Ramos, Miguel; Fernandez, Esteve; Soriano, Joan B
2018-07-01
The impact of smoke-free legislation within European Union (EU) countries on lung cancer mortality has not been evaluated to date. We aimed to determine lung cancer mortality trends in the EU-27 by sex, age, and calendar year for the period of 1994 and 2012, and relate them with changes in tobacco legislation at the national level. Deaths by Eurostat in each European country were analyzed, focusing on ICD-10 codes C33 and C34 from the years 1994 to 2012. Age-standardized mortality rates (ASR) were estimated separately for women and men in the EU-27 total and within country for each one of the years studied, and the significance of changing trends was estimated by joinpoint regression analysis, exploring lag times after initiation of smoke-free legislation in every country, if any. From 1994 to 2012, there were 4 681 877 deaths from lung cancer in Europe (3 491 607 in men and 1 190 180 in women) and a nearly linear decrease in mortality rates because of lung cancer in men from was observed1994 to 2012, mirrored in women by an upward trend, narrowing the sex gap during the study period from 5.1 in 1994 to 2.8 in 2012. Joinpoint regression analysis identified a number of trend changes over time, but it appears that they were unrelated to the implementation of smoke-free legislations. A few years after the introduction of smoke-free legislations across Europe, trends of lung cancer mortality trends have not changed.
NASA Astrophysics Data System (ADS)
Nigam, S.; Thomas, N. P.
2017-12-01
Twentieth-century trends in seasonal temperature and precipitation over the African continent are analyzed from observational data sets and historical climate simulations. Given the agricultural economy of the continent, a seasonal perspective is adopted as it is more pertinent than an annual-average one which can mask off-setting but agriculturally-sensitive seasonal hydroclimate variations. Examination of linear trends in seasonal surface air temperature (SAT) shows that heat stress has increased in several regions, including Sudan and Northern Africa where largest SAT trends occur in the warm season. Broadly speaking, the northern continent has warmed more than the southern one in all seasons. Precipitation trends are varied but notable declining trends are found in the countries along the Gulf of Guinea, especially in the source region of Niger river in West Africa, and in the Congo river basin. Rainfall over the African Great Lakes - one of the largest freshwater repositories - has however increased. We show that the Sahara Desert has expanded significantly over the 20th century - by 12-20% depending on the season. The desert expanded southward in summer, reflecting retreat of the northern edge of the Sahel rainfall belt; and to the north in winter, indicating potential impact of the widening of the Tropics. Specific mechanisms driving the expansion in each season are investigated. Finally, this observational analysis is used to evaluate the state-of-the-art climate models from a comparison of the 20th-century hydroclimate trends with those manifest in historical climate simulations. The evaluation shows that modeling regional hydroclimate change over the Africa continent remains challenging.
E, Sheng Zhe; Yang, Zhi Qi; Zeng, Xi Bai; Wang, Ya Nan; Luo, Zhao Xia; Yuan, Jin Hua; Che, Zong Xian
2017-11-01
The changing trend of soil available phosphorus (Olsen-P) content in soil and its relationship with soil phosphorus surplus and crop yield are fundamental when making appropriate phosphate fertilizer recommendations. In this paper, the influences of long-term fertilization on crops phosphorus uptake, soil phosphorus surplus, changing trend of soil available phosphorus content and relationships of soil available phosphorus content with soil phosphorus surplus and crop yield were investigated through 34 years (1981-2015) long-term trial in loessial soil region on the Loess Plateau. The experiment had a completely-randomized-block split-plot design in triplicate. Two main-plot treatments were no farmyard manure and farmyard manure (M), and four subplot treatments were CK (no fertilizer), N (application of chemical fertilizer N), NP (application of chemical fertilizer NP) and NPK (balanced application of chemical fertilizer NPK), respectively. The results showed that fertilization treatments and crop types significantly influenced uptake amount of phosphorus and soil phosphorus surplus. Averaged over time from 1981 to 2015, wheat mean phosphorus uptake amounts of CK, N, NP, NPK, M, MN, MNP and MNPK were 8.63, 10.64, 16.22, 16.21, 16.25, 17.83, 20.39 and 20.27 kg·hm -2 , while rape phosphorus uptakeamounts of eight treatments were 4.40, 8.38, 15.08, 15.71, 10.52, 11.23, 17.96 and 17.66 kg·hm -2 , respectively. The surplus amount of soil phosphorus significantly correlated with the amount of phosphorus applied to soil. When soil phosphorus surplus amount equal zero, wheat and rape phosphorus input amounts were 10.47 kg·hm -2 and 6.97 kg·hm -2 , respectively. Soil phosphorus surplus amount significantly influenced the changing trend of available phosphorus content in soil. CK and N treatments had no phosphorus input, and soil available phosphorus content exhibited a declining trend, annually decreased by 0.16 mg·kg -1 and 0.15 mg·kg -1 , respectively. In contrast, NP, NPK, M, MN, MNP and MNPK six treatments were applied with phosphate fertilizer every years, and available phosphorus content gradually increased along with the duration of trial, with annual increase by 0.02-0.33 mg·kg -1 . Soil available phosphorus content significantly correlated with phosphorus accumulative surplus amount, and the linear models were y=0.012x+9.33 and y=0.009x+11.72 in manure and no manure treatments, respectively. In no manure treatments, wheat yields significantly positively correlated with soil available phosphorus content, however, in manure treatments, their relationships did not reach a significant level. The relationship of wheat grain yield with available phosphorus content could be significantly fitted by piecewise linear model, and available phosphorus agronomy threshold of wheat was 14.99 mg·kg -1 . Rape grain yield also increased with increasing soil available phosphorus content, but the relationship was not significant. This indicated when soil available P content is higher than 14.99 mg·kg -1 , application of phosphate fertili-zer should be reduced or even avoided for planting wheat in loessial soil region on the Loess Plateau.
Ryvolova, Marketa; Smerkova, Kristyna; Chomoucka, Jana; Hubalek, Jaromir; Adam, Vojtech; Kizek, Rene
2013-03-01
Cisplatin, carboplatin, and oxaliplatin represent three generations of platinum based drugs applied successfully for cancer treatment. As a consequence of the employment of platinum based cytostatics in the cancer treatment, it became necessary to study the mechanism of their action. Current accepted opinion is the formation of Pt-DNA adducts, but the mechanism of their formation is still unclear. Nanomaterials, as a progressively developing branch, can offer a tool for studying the interactions of these drugs with DNA. In this study, fluorescent CdTe quantum dots (QDs, λem = 525 nm) were employed to investigate the interactions of platinum cytostatics (cisplatin, carboplatin, and oxaliplatin) with DNA fragment (500 bp, c = 25 μg/mL). Primarily, the fluorescent behavior of QDs in the presence of platinum cytostatics was monitored and major differences in the interaction of QDs with tested drugs were observed. It was found that the presence of carboplatin (c = 0.25 mg/mL) had no significant influence on QDs fluorescence; however cisplatin and oxaliplatin quenched the fluorescence significantly (average decrease of 20%) at the same concentration. Subsequently, the amount of platinum incorporated in DNA was determined by QDs fluorescence quenching. Best results were reached using oxaliplatin (9.4% quenching). Linear trend (R(2) = 0.9811) was observed for DNA platinated by three different concentrations of oxaliplatin (0.250, 0.125, and 0.063 mg/mL). Correlation with differential pulse voltammetric measurements provided linear trend (R(2) = 0.9511). As a conclusion, especially in the case of oxaliplatin-DNA adducts, the quenching was the most significant compared to cisplatin and nonquenching carboplatin. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Sperm quality variables as indicators of bull fertility may be breed dependent.
Morrell, Jane M; Nongbua, Thanapol; Valeanu, Sabina; Lima Verde, Isabel; Lundstedt-Enkel, Katrin; Edman, Anders; Johannisson, Anders
2017-10-01
A means of discriminating among bulls of high fertility based on sperm quality is needed by breeding centers. The objective of the study was to examine parameters of sperm quality in bulls of known fertility to identify useful indicators of fertility. Frozen semen was available from bulls of known fertility (Viking Genetics, Skara, Sweden): Swedish Red (n=31), Holstein (n=25) and Others (one each of Charolais, Limousin, Blonde, SKB). After thawing, the sperm samples were analyzed for motility (computer assisted sperm analysis), plasma membrane integrity, chromatin integrity, acrosome status, mitochondrial activity and reactive oxygen species. A fertility index score based on the adjusted 56-day non-return rate for >1000 inseminations was available for each bull. Multivariate data analysis (Partial Least Squares Regression and Orthogonal Partial Least Squares Regression) was performed to identify variables related to fertility; Pearson univariate correlations were made on the parameters of interest. Breed of bull affected the relationship of sperm quality variables and fertility index score, as follows: Swedish Red: %DNA Fragmentation Index, r=-0.56, P<0.01; intact plasma membrane, r=0.40, P<0.05; membrane damaged, not acrosome reacted, r=-0.6, P<0.01; Linearity, r=0.37, P<0.05; there was a trend towards significance for Wobble, r=0.34, P=0.08. Holstein: Linearity was significant r=0.46, P<0.05; there was a trend towards significance for Wobble, r=0.45, P=0.08. In conclusion, breed has a greater effect on sperm quality than previously realized; different parameters of sperm quality are needed to indicate potential fertility in different breeds. Copyright © 2017 Elsevier B.V. All rights reserved.
NASA Astrophysics Data System (ADS)
Avecilla, Fernando; Panebianco, Juan E.; Mendez, Mariano J.; Buschiazzo, Daniel E.
2018-06-01
The PM10 emission efficiency of soils has been determined through different methods. Although these methods imply important physical differences, their outputs have never been compared. In the present study the PM10 emission efficiency was determined for soils through a wide range of textures, using three typical methodologies: a rotary-chamber dust generator (EDG), a laboratory wind tunnel on a prepared soil bed, and field measurements on an experimental plot. Statistically significant linear correlation was found (p < 0.05) between the PM10 emission efficiency obtained from the EDG and wind tunnel experiments. A significant linear correlation (p < 0.05) was also found between the PM10 emission efficiency determined both with the wind tunnel and the EDG, and a soil texture index (%sand + %silt)/(%clay + %organic matter) that reflects the effect of texture on the cohesion of the aggregates. Soils with higher sand content showed proportionally less emission efficiency than fine-textured, aggregated soils. This indicated that both methodologies were able to detect similar trends regarding the correlation between the soil texture and the PM10 emission. The trends attributed to soil texture were also verified for two contrasting soils under field conditions. However, differing conditions during the laboratory-scale and the field-scale experiments produced significant differences in the magnitude of the emission efficiency values. The causes of these differences are discussed within the paper. Despite these differences, the results suggest that standardized laboratory and wind tunnel procedures are promissory methods, which could be calibrated in the future to obtain results comparable to field values, essentially through adjusting the simulation time. However, more studies are needed to extrapolate correctly these values to field-scale conditions.
Parikh, Samip; Guo, De-huang; Pollock, Norman K.; Petty, Karen; Bhagatwala, Jigar; Gutin, Bernard; Houk, Chris; Zhu, Haidong; Dong, Yanbin
2012-01-01
OBJECTIVE Low vitamin D status is common among healthy black and white adolescents residing at southern U.S. latitudes with a year-round sunny climate. Thus we aimed to study the relationships between circulating 25-hydroxyvitamin D [25(OH)D] and cardiometabolic risk factors in this population. RESEARCH DESIGN AND METHODS 25(OH)D concentrations were measured with liquid chromatography tandem mass spectroscopy in 701 girls and boys (14–18 years old, 54% blacks, 49% females). Cardiometabolic risk was indexed by adipokines, inflammatory markers, fasting glucose, homeostatic model assessment-insulin resistance (HOMA-IR), lipid profile, and blood pressure (BP). RESULTS Controlling for age, sex, race, sexual maturation, season, physical activity, and percent body fat, 25(OH)D concentrations were significantly correlated with adiponectin (r = 0.06, P = 0.05), leptin (r = −0.32, P < 0.01), fibrinogen (r = −0.05, P = 0.03), glucose (r = −0.16, P = 0.02), HOMA-IR (r = −0.17, P < 0.01), HDL cholesterol (r = 0.14, P = 0.02), systolic BP (r = −0.10, P = 0.02), and diastolic BP (r = −0.21, P < 0.01). When 25(OH)D concentrations were stratified into increasing tertiles, there were significant linear upward trends for adiponectin (P = 0.01) and HDL cholesterol (P = 0.04), but significant linear down trends for glucose (P < 0.01), HOMA-IR (P < 0.01), and systolic BP (P < 0.01), after adjusting for the above covariates. CONCLUSIONS Circulating 25(OH)D concentrations are associated with various adverse cardiometabolic risk factors, independent of adiposity. Clinical trials addressing the effects of vitamin D supplementation on cardiometabolic risk are warranted in adolescents irrespective of their geographical regions. PMID:22410810
Choi, Yoon-Hyeong; Kim, Jin Hee; Hong, Yun-Chul
2015-01-01
Background The prevalence of metabolic diseases rises rapidly with an ageing population. Recent studies suggest the potential involvement of environmental chemicals in insulin resistance (IR) that plays a core role in the development of metabolic diseases. Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous components of outdoor and indoor air pollution. The influence of PAHs on IR may differ depending on sex and weight. Objectives We examined the association between exposure to environmental PAHs and IR in Korean urban elderly adults controlling for major risk factors that contribute to an increase in IR. Methods Between 2008 and 2010, PAH metabolite levels (urinary 1-hydroxypyrene (1-OHP)) and the homoeostatic model assessment index (HOMA-IR) were repeatedly measured in 502 adults aged ≥60 years. Linear mixed effect models were fit to evaluate the associations of 1-OHP concentration with HOMA-IR. Subgroups were modelled by sex and weight. Results After adjusting for sociodemographics, air pollution and metabolic disease status, the highest (vs lowest) quartile of 1-OHP was associated with an 0.57 (95% CI 0.10 to 1.04) increase in the HOMA-IR score (p trend=0.037). When stratified by sex, women presented a significantly dose-dependent trend of 1-OHP with HOMA-IR (p trend=0.013), whereas no association was observed in men (p trend=0.904). When further stratified by weight (body mass index ≥25 vs <25 kg/m2), a significant association was found only in overweight women (p trend=0.023). Conclusions Our results suggest that environmental exposure to PAHs is associated with increased IR in elderly adults and that the association may be limited to overweight women. PMID:25669219
Dikshit, Rajesh P; Yeole, B B; Nagrani, Rajini; Dhillon, P; Badwe, R; Bray, Freddie
2012-08-01
Increasing trends in the incidence of breast cancer have been observed in India, including Mumbai. These have likely stemmed from an increasing adoption of lifestyle factors more akin to those commonly observed in westernized countries. Analyses of breast cancer trends and corresponding estimation of the future burden are necessary to better plan rationale cancer control programmes within the country. We used data from the population-based Mumbai Cancer Registry to study time trends in breast cancer incidence rates 1976-2005 and stratified them according to younger (25-49) and older age group (50-74). Age-period-cohort models were fitted and the net drift used as a measure of the estimated annual percentage change (EAPC). Age-period-cohort models and population projections were used to predict the age-adjusted rates and number of breast cancer cases circa 2025. Breast cancer incidence increased significantly among older women over three decades (EAPC = 1.6%; 95% CI 1.1-2.0), while lesser but significant 1% increase in incidence among younger women was observed (EAPC = 1.0; 95% CI 0.2-1.8). Non-linear period and cohort effects were observed; a trends-based model predicted a close-to-doubling of incident cases by 2025 from 1300 mean cases per annum in 2001-2005 to over 2500 cases in 2021-2025. The incidence of breast cancer has increased in Mumbai during last two to three decades, with increases greater among older women. The number of breast cancer cases is predicted to double to over 2500 cases, the vast majority affecting older women. Copyright © 2012 Elsevier Ltd. All rights reserved.
Variability of temperature properties over Kenya based on observed and reanalyzed datasets
NASA Astrophysics Data System (ADS)
Ongoma, Victor; Chen, Haishan; Gao, Chujie; Sagero, Phillip Obaigwa
2017-08-01
Updated information on trends of climate extremes is central in the assessment of climate change impacts. This work examines the trends in mean, diurnal temperature range (DTR), maximum and minimum temperatures, 1951-2012 and the recent (1981-2010) extreme temperature events over Kenya. The study utilized daily observed and reanalyzed monthly mean, minimum, and maximum temperature datasets. The analysis was carried out based on a set of nine indices recommended by the Expert Team on Climate Change Detection and Indices (ETCCDI). The trend of the mean and the extreme temperature was determined using Mann-Kendall rank test, linear regression analysis, and Sen's slope estimator. December-February (DJF) season records high temperature while June-August (JJA) experiences the least temperature. The observed rate of warming is + 0.15 °C/decade. However, DTR does not show notable annual trend. Both seasons show an overall warming trend since the early 1970s with abrupt and significant changes happening around the early 1990s. The warming is more significant in the highland regions as compared to their lowland counterparts. There is increase variance in temperature. The percentage of warm days and warm nights is observed to increase, a further affirmation of warming. This work is a synoptic scale study that exemplifies how seasonal and decadal analyses, together with the annual assessments, are important in the understanding of the temperature variability which is vital in vulnerability and adaptation studies at a local/regional scale. However, following the quality of observed data used herein, there remains need for further studies on the subject using longer and more data to avoid generalizations made in this study.
Kovalska, M P; Bürki, E; Schoetzau, A; Orguel, S F; Orguel, S; Grieshaber, M C
2011-04-01
The distinction of real progression from test variability in visual field (VF) series may be based on clinical judgment, on trend analysis based on follow-up of test parameters over time, or on identification of a significant change related to the mean of baseline exams (event analysis). The aim of this study was to compare a new population-based method (Octopus field analysis, OFA) with classic regression analyses and clinical judgment for detecting glaucomatous VF changes. 240 VF series of 240 patients with at least 9 consecutive examinations available were included into this study. They were independently classified by two experienced investigators. The results of such a classification served as a reference for comparison for the following statistical tests: (a) t-test global, (b) r-test global, (c) regression analysis of 10 VF clusters and (d) point-wise linear regression analysis. 32.5 % of the VF series were classified as progressive by the investigators. The sensitivity and specificity were 89.7 % and 92.0 % for r-test, and 73.1 % and 93.8 % for the t-test, respectively. In the point-wise linear regression analysis, the specificity was comparable (89.5 % versus 92 %), but the sensitivity was clearly lower than in the r-test (22.4 % versus 89.7 %) at a significance level of p = 0.01. A regression analysis for the 10 VF clusters showed a markedly higher sensitivity for the r-test (37.7 %) than the t-test (14.1 %) at a similar specificity (88.3 % versus 93.8 %) for a significant trend (p = 0.005). In regard to the cluster distribution, the paracentral clusters and the superior nasal hemifield progressed most frequently. The population-based regression analysis seems to be superior to the trend analysis in detecting VF progression in glaucoma, and may eliminate the drawbacks of the event analysis. Further, it may assist the clinician in the evaluation of VF series and may allow better visualization of the correlation between function and structure owing to VF clusters. © Georg Thieme Verlag KG Stuttgart · New York.
Trend time-series modeling and forecasting with neural networks.
Qi, Min; Zhang, G Peter
2008-05-01
Despite its great importance, there has been no general consensus on how to model the trends in time-series data. Compared to traditional approaches, neural networks (NNs) have shown some promise in time-series forecasting. This paper investigates how to best model trend time series using NNs. Four different strategies (raw data, raw data with time index, detrending, and differencing) are used to model various trend patterns (linear, nonlinear, deterministic, stochastic, and breaking trend). We find that with NNs differencing often gives meritorious results regardless of the underlying data generating processes (DGPs). This finding is also confirmed by the real gross national product (GNP) series.
Cancer Mortality Among Men in Central Serbia: 1985-2006 Survey Study
Marković-Denić, Ljiljana; Vlajinac, Hristina; Živković, Snežana; Miljuš, Dragan
2008-01-01
Aim To analyze cancer mortality trends in men in Central Serbia during 1985-2006 period. Methods Mortality rates and trends for the most frequent cancers in men (lung, stomach, colorectal, pancreatic, and prostate cancer) were calculated. Mortality rates for all cancers were adjusted by direct standardization. Percentage changes of the rates were calculated as the percentage difference between the rates of two successive years and then as a mean of these changes for the entire observed period. Trend lines were estimated using linear regression. Results Total cancer mortality in men increased, with mean percentage of annual changes being 1.53% (95% confidence interval [CI], -0.09-3.16). Lung, stomach, colorectal, pancreatic, and prostate cancers represented 58.1% and 61.6% of total cancer deaths in 1985 and 2006, respectively. Increasing trends were observed for all investigated cancers: mean annual percentage change for lung cancer was 2.31%(95% CI, 1.03-3.59), for colorectal cancer 2.23% (95% CI, -0.18-4.65), for prostate cancer 3.06% (95% CI, -2.07-8.18), and for pancreatic cancer 1.58% (95% CI, -2.17-5.32). Stomach cancer mortality significantly decreased in age groups 40-49 and 50-59 years. Conclusion The most frequent cancers in men in Central Serbia, ie, lung, colorectal, prostate, and pancreatic cancer, showed an increasing trend. Only stomach cancer mortality decreased over time. PMID:19090604
Trends in spawning populations of Pacific anadromous salmonids
Konkel, G.W.; McIntyre, J.D.
1987-01-01
Annual escapement records for 1968-1984 for five species of Pacific salmon-chinook (Oncorhynchus tshawytscha), coho (O. kisutch), sockeye (O. nerka), pink (O. gorbuscha), and chum (O. keta)—and steelhead (Salmo gairdneri) were obtained from published and unpublished sources and organized in a computer database. More than 25,500 escapement records were obtained for more than 1,100 locations throughout Alaska, Washington, Idaho, Oregon, and California. Escapement trends for naturally reproducing populations for which data were available for at least 7 years from 1968 to 1984 and at least 4 years from 1975 to 1984 were analyzed by linear regression. Significant trends were observed in about 30% of the 886 populations examined. Trends were summarized by species for three geographic regions in Alaska and four in the Pacific Northwest (including California). For chinook, sockeye, and pink salmon, trends were predominantly increasing in the Alaska regions and either lacking or predominantly decreasing in most of the Pacific Northwest regions; for coho and chum salmon, trends were predominantly decreasing in one or more Alaska regions as well as in most of the Pacific Northwest regions. For steelhead, too few populations were examined to enable us to characterize trends throughout their range. Among the 657 salmonid populations excluded from the trend analysis because the data sets were incomplete, 13 (of which 2 were in Alaska) declined to zero during the period of analysis. For coho, sockeye, pink, and chum salmon and steelhead, major data gaps were revealed by a comparison of the geographic distribution of escapement records with the spawning distribution of the species. For chinook salmon, escapement records were more geographically representative of the spawning distribution.
Algorithmic Trading with Developmental and Linear Genetic Programming
NASA Astrophysics Data System (ADS)
Wilson, Garnett; Banzhaf, Wolfgang
A developmental co-evolutionary genetic programming approach (PAM DGP) and a standard linear genetic programming (LGP) stock trading systemare applied to a number of stocks across market sectors. Both GP techniques were found to be robust to market fluctuations and reactive to opportunities associated with stock price rise and fall, with PAMDGP generating notably greater profit in some stock trend scenarios. Both algorithms were very accurate at buying to achieve profit and selling to protect assets, while exhibiting bothmoderate trading activity and the ability to maximize or minimize investment as appropriate. The content of the trading rules produced by both algorithms are also examined in relation to stock price trend scenarios.
NASA Astrophysics Data System (ADS)
Wayan Mangku, I.
2017-10-01
In this paper we survey some results on estimation of the intensity function of a cyclic Poisson process in the presence of additive and multiplicative linear trend. We do not assume any parametric form for the cyclic component of the intensity function, except that it is periodic. Moreover, we consider the case when there is only a single realization of the Poisson process is observed in a bounded interval. The considered estimators are weakly and strongly consistent when the size of the observation interval indefinitely expands. Asymptotic approximations to the bias and variance of those estimators are presented.
Weidemann, Gabrielle; Tangen, Jason M; Lovibond, Peter F; Mitchell, Christopher J
2009-04-01
P. Perruchet (1985b) showed a double dissociation of conditioned responses (CRs) and expectancy for an airpuff unconditioned stimulus (US) in a 50% partial reinforcement schedule in human eyeblink conditioning. In the Perruchet effect, participants show an increase in CRs and a concurrent decrease in expectancy for the airpuff across runs of reinforced trials; conversely, participants show a decrease in CRs and a concurrent increase in expectancy for the airpuff across runs of nonreinforced trials. Three eyeblink conditioning experiments investigated whether the linear trend in eyeblink CRs in the Perruchet effect is a result of changes in associative strength of the conditioned stimulus (CS), US sensitization, or learning the precise timing of the US. Experiments 1 and 2 demonstrated that the linear trend in eyeblink CRs is not the result of US sensitization. Experiment 3 showed that the linear trend in eyeblink CRs is present with both a fixed and a variable CS-US interval and so is not the result of learning the precise timing of the US. The results are difficult to reconcile with a single learning process model of associative learning in which expectancy mediates CRs. Copyright (c) 2009 APA, all rights reserved.
Terracciano, Antonio; McCrae, Robert R.; Brant, Larry J.; Costa, Paul T.
2009-01-01
We examined age trends in the five factors and 30 facets assessed by the Revised NEO Personality Inventory in Baltimore Longitudinal Study of Aging data (N = 1,944; 5,027 assessments) collected between 1989 and 2004. Consistent with cross-sectional results, Hierarchical Linear Modeling analyses showed gradual personality changes in adulthood: a decline up to age 80 in Neuroticism, stability and then decline in Extraversion, decline in Openness, increase in Agreeableness, and increase up to age 70 in Conscientiousness. Some facets showed different curves from the factor they define. Birth cohort effects were modest, and there were no consistent Gender × Age interactions. Significant non-normative changes were found for all five factors; they were not explained by attrition but might be due to genetic factors, disease, or life experience. PMID:16248708
Skillful prediction of hot temperature extremes over the source region of ancient Silk Road.
Zhang, Jingyong; Yang, Zhanmei; Wu, Lingyun
2018-04-27
The source region of ancient Silk Road (SRASR) in China, a region of around 150 million people, faces a rapidly increased risk of extreme heat in summer. In this study, we develop statistical models to predict summer hot temperature extremes over the SRASR based on a timescale decomposition approach. Results show that after removing the linear trends, the inter-annual components of summer hot days and heatwaves over the SRASR are significantly related with those of spring soil temperature over Central Asia and sea surface temperature over Northwest Atlantic while their inter-decadal components are closely linked to those of spring East Pacific/North Pacific pattern and Atlantic Multidecadal Oscillation for 1979-2016. The physical processes involved are also discussed. Leave-one-out cross-validation for detrended 1979-2016 time series indicates that the statistical models based on identified spring predictors can predict 47% and 57% of the total variances of summer hot days and heatwaves averaged over the SRASR, respectively. When the linear trends are put back, the prediction skills increase substantially to 64% and 70%. Hindcast experiments for 2012-2016 show high skills in predicting spatial patterns of hot temperature extremes over the SRASR. The statistical models proposed herein can be easily applied to operational seasonal forecasting.
Brock, John C.; Krabill, William; Sallenger, Asbury H.
2004-01-01
In order to reap the potential of airborne lidar surveys to provide geological information useful in understanding coastal sedimentary processes acting on various time scales, a new set of analysis methods are needed. This paper presents a multi-temporal lidar analysis of north Assateague Island, Maryland, and demonstrates the calculation of lidar metrics that condense barrier island morphology and morphological change into attributed linear features that may be used to analyze trends in coastal evolution. The new methods proposed in this paper are also of significant practical value, because lidar metric analysis reduces large volumes of point elevations into linear features attributed with essential morphological variables that are ideally suited for inclusion in Geographic Information Systems. A morphodynamic classification of north Assategue Island for a recent 10 month time period that is based on the recognition of simple patterns described by lidar change metrics is presented. Such morphodynamic classification reveals the relative magnitude and the fine scale alongshore variation in the importance of coastal changes over the study area during a defined time period. More generally, through the presentation of this morphodynamic classification of north Assateague Island, the value of lidar metrics in both examining large lidar data sets for coherent trends and in building hypotheses regarding processes driving barrier evolution is demonstrated
Prediction of Cancer Incidence and Mortality in Korea, 2018.
Jung, Kyu-Won; Won, Young-Joo; Kong, Hyun-Joo; Lee, Eun Sook
2018-04-01
This study aimed to report on cancer incidence and mortality for the year 2018 to estimate Korea's current cancer burden. Cancer incidence data from 1999 to 2015 were obtained from the Korea National Cancer Incidence Database, and cancer mortality data from 1993 to 2016 were acquired from Statistics Korea. Cancer incidence and mortality were projected by fitting a linear regression model to observed age-specific cancer rates against observed years, then multiplying the projected age-specific rates by the age-specific population. The Joinpoint regression model was used to determine at which year the linear trend changed significantly, we only used the data of the latest trend. A total of 204,909 new cancer cases and 82,155 cancer deaths are expected to occur in Korea in 2018. The most common cancer sites were lung, followed by stomach, colorectal, breast and liver. These five cancers represent half of the overall burden of cancer in Korea. For mortality, the most common sites were lung cancer, followed by liver, colorectal, stomach and pancreas. The incidence rate of all cancer in Korea are estimated to decrease gradually, mainly due to decrease of thyroid cancer. These up-to-date estimates of the cancer burden in Korea could be an important resource for planning and evaluation of cancer-control programs.
ERIC Educational Resources Information Center
Mandys, Frantisek; Dolan, Conor V.; Molenaar, Peter C. M.
1994-01-01
Studied the conditions under which the quasi-Markov simplex model fits a linear growth curve covariance structure and determined when the model is rejected. Presents a quasi-Markov simplex model with structured means and gives an example. (SLD)
Evaluating abundance and trends in a Hawaiian avian community using state-space analysis
Camp, Richard J.; Brinck, Kevin W.; Gorresen, P.M.; Paxton, Eben H.
2016-01-01
Estimating population abundances and patterns of change over time are important in both ecology and conservation. Trend assessment typically entails fitting a regression to a time series of abundances to estimate population trajectory. However, changes in abundance estimates from year-to-year across time are due to both true variation in population size (process variation) and variation due to imperfect sampling and model fit. State-space models are a relatively new method that can be used to partition the error components and quantify trends based only on process variation. We compare a state-space modelling approach with a more traditional linear regression approach to assess trends in uncorrected raw counts and detection-corrected abundance estimates of forest birds at Hakalau Forest National Wildlife Refuge, Hawai‘i. Most species demonstrated similar trends using either method. In general, evidence for trends using state-space models was less strong than for linear regression, as measured by estimates of precision. However, while the state-space models may sacrifice precision, the expectation is that these estimates provide a better representation of the real world biological processes of interest because they are partitioning process variation (environmental and demographic variation) and observation variation (sampling and model variation). The state-space approach also provides annual estimates of abundance which can be used by managers to set conservation strategies, and can be linked to factors that vary by year, such as climate, to better understand processes that drive population trends.
Recent trends in rainfall and temperature over North West India during 1871-2016
NASA Astrophysics Data System (ADS)
Saxena, Rani; Mathur, Prasoon
2018-03-01
Rainfall and temperature are the most important environmental factors influencing crop growth, development, and yield. The northwestern (NW) part of India is one of the main regions of food grain production of the country. It comprises of six meteorological subdivisions (Haryana, Punjab, West Rajasthan, East Rajasthan, Gujarat and Saurashtra, Kutch and Diu). In this study, attempts were made to study variability and trends in rainfall and temperature during 30-year climate normal periods (CN) and 10-year decadal excess or deficit rainfall frequency during the historical period from 1871 to 2016. The Mann-Kendall and Spearman's rank correlation (Spearman's rho) tests were used to determine significance of trends. Least square linear fitting method was adopted to find out the slopes of the trend lines. The long-term mean annual rainfall over North West India is 587.7 mm (standard deviation of 153.0 mm and coefficient of variation 26.0). There was increasing trend in minimum and maximum temperatures during post monsoon season in entire study period and current climate normal period (1991-2016) due to which the sowing of rabi season crops may be delayed and there may be germination problem too. There was a non-significant decreasing trend in rainfall during monsoon season and an increasing trend in rainfall during post monsoon over North West India during entire study period. During current CN5 (1991-2016), all the subdivision (except the Saurashtra region) showed a decreasing trend in rainfall during monsoon season which is a matter of concern for kharif crops and those rabi crops which are grown as rainfed on conserved soil moisture. The decadal annual and seasonal frequencies of excess and deficit years results revealed that the annual total deficit rainfall years (24) exceeded total excess rainfall years (22) in North West India during the entire study period. While during the current decadal period (2011 to 2016), single year was the excess year and 2 years were deficit rainfall years in all subdivisions (except East Rajasthan) on annual basis.
Bayesian spatiotemporal crash frequency models with mixture components for space-time interactions.
Cheng, Wen; Gill, Gurdiljot Singh; Zhang, Yongping; Cao, Zhong
2018-03-01
The traffic safety research has developed spatiotemporal models to explore the variations in the spatial pattern of crash risk over time. Many studies observed notable benefits associated with the inclusion of spatial and temporal correlation and their interactions. However, the safety literature lacks sufficient research for the comparison of different temporal treatments and their interaction with spatial component. This study developed four spatiotemporal models with varying complexity due to the different temporal treatments such as (I) linear time trend; (II) quadratic time trend; (III) Autoregressive-1 (AR-1); and (IV) time adjacency. Moreover, the study introduced a flexible two-component mixture for the space-time interaction which allows greater flexibility compared to the traditional linear space-time interaction. The mixture component allows the accommodation of global space-time interaction as well as the departures from the overall spatial and temporal risk patterns. This study performed a comprehensive assessment of mixture models based on the diverse criteria pertaining to goodness-of-fit, cross-validation and evaluation based on in-sample data for predictive accuracy of crash estimates. The assessment of model performance in terms of goodness-of-fit clearly established the superiority of the time-adjacency specification which was evidently more complex due to the addition of information borrowed from neighboring years, but this addition of parameters allowed significant advantage at posterior deviance which subsequently benefited overall fit to crash data. The Base models were also developed to study the comparison between the proposed mixture and traditional space-time components for each temporal model. The mixture models consistently outperformed the corresponding Base models due to the advantages of much lower deviance. For cross-validation comparison of predictive accuracy, linear time trend model was adjudged the best as it recorded the highest value of log pseudo marginal likelihood (LPML). Four other evaluation criteria were considered for typical validation using the same data for model development. Under each criterion, observed crash counts were compared with three types of data containing Bayesian estimated, normal predicted, and model replicated ones. The linear model again performed the best in most scenarios except one case of using model replicated data and two cases involving prediction without including random effects. These phenomena indicated the mediocre performance of linear trend when random effects were excluded for evaluation. This might be due to the flexible mixture space-time interaction which can efficiently absorb the residual variability escaping from the predictable part of the model. The comparison of Base and mixture models in terms of prediction accuracy further bolstered the superiority of the mixture models as the mixture ones generated more precise estimated crash counts across all four models, suggesting that the advantages associated with mixture component at model fit were transferable to prediction accuracy. Finally, the residual analysis demonstrated the consistently superior performance of random effect models which validates the importance of incorporating the correlation structures to account for unobserved heterogeneity. Copyright © 2017 Elsevier Ltd. All rights reserved.
Rodriguez, Brian D.; Sampson, Jay A.; Williams, Jackie M.
2007-01-01
The Great Basin physiographic province covers a large part of the western United States and contains one of the world's leading gold-producing areas, the Carlin Trend. In the Great Basin, many sedimentary-rock-hosted disseminated gold deposits occur along such linear mineral-occurrence trends. The distribution and genesis of these deposits is not fully understood, but most models indicate that regional tectonic structures play an important role in their spatial distribution. Over 100 magnetotelluric (MT) soundings were acquired between 1994 and 2001 by the U.S. Geological Survey to investigate crustal structures that may underlie the linear trends in north-central Nevada. MT sounding data were used to map changes in electrical resistivity as a function of depth that are related to subsurface lithologic and structural variations. Two-dimensional (2-D) resistivity modeling of the MT data reveals primarily northerly and northeasterly trending narrow 2-D conductors (1 to 30 ohm-m) extending to mid-crustal depths (5-20 km) that are interpreted to be major crustal fault zones. There are also a few westerly and northwesterly trending 2-D conductors. However, the great majority of the inferred crustal fault zones mapped using MT are perpendicular or oblique to the generally accepted trends. The correlation of strike of three crustal fault zones with the strike of the Carlin and Getchell trends and the Alligator Ridge district suggests they may have been the root fluid flow pathways that fed faults and fracture networks at shallower levels where gold precipitated in favorable host rocks. The abundant northeasterly crustal structures that do not correlate with the major trends may be structures that are open to fluid flow at the present time.
NASA Astrophysics Data System (ADS)
Rose, Sean D.; Roth, Jacob; Zimmerman, Cole; Reiser, Ingrid; Sidky, Emil Y.; Pan, Xiaochuan
2018-03-01
In this work we investigate an efficient implementation of a region-of-interest (ROI) based Hotelling observer (HO) in the context of parameter optimization for detection of a rod signal at two orientations in linear iterative image reconstruction for DBT. Our preliminary results suggest that ROI-HO performance trends may be efficiently estimated by modeling only the 2D plane perpendicular to the detector and containing the X-ray source trajectory. In addition, the ROI-HO is seen to exhibit orientation dependent trends in detectability as a function of the regularization strength employed in reconstruction. To further investigate the ROI-HO performance in larger 3D system models, we present and validate an iterative methodology for calculating the ROI-HO. Lastly, we present a real data study investigating the correspondence between ROI-HO performance trends and signal conspicuity. Conspicuity of signals in real data reconstructions is seen to track well with trends in ROI-HO detectability. In particular, we observe orientation dependent conspicuity matching the orientation dependent detectability of the ROI-HO.
Soldin, O.P.; Tractenberg, R.E.; Hollowell, J.G.; Jonklaas, J.; Janicic, N.; Soldin, S.J.
2013-01-01
Objectives To describe the interrelationships of thyroid functions based on trimester-specific concentrations in healthy, iodine-sufficient pregnant women across trimesters, and postpartum. Methods Circulating total 3,5,3′-triidothyronine (T3) and thyroxine (T4) concentrations were determined simultaneously using liquid chromatography tandem mass-spectrometry (LC/MS/MS). Free thyroxine (FT4), thyroid-stimulating hormone (TSH), and thyroglobulin (Tg) were measured using immunoassay techniques. Linear mixed effects models and correlations were calculated to determine trends and associations, respectively, in concentrations. Results and conclusions Trimester-specific T3, FT4, TSH, and Tg concentrations were significantly different between the first and third trimesters (all p < 0.05); second and third trimester values were not significantly different for FT4, TSH, and Tg (all p > 0.25) although T3 was significantly higher in the third, relative to the second trimester. T4 was not significantly different at any trimester (all p > 0.80). With two exceptions, analyte concentrations tended not to be correlated at each trimester and at 1-year postpartum. One exception was that T3 and T4 tended to be associated (all p < 0.05) at all time points except the third trimester (ρ = 0.239, p > 0.05). T4 and FT4 concentrations tended to correlate positively during pregnancy (ρ 0.361–0.382, all p < 0.05) but not postpartum (ρ = 0.179, p > 0.05). Trends suggest that trimester-specific measurements of T3, FT4, Tg, and possibly TSH are warranted. PMID:15650363
Faults on Skylab imagery of the Salton Trough area, Southern California
NASA Technical Reports Server (NTRS)
Merifield, P. M.; Lamar, D. L. (Principal Investigator)
1975-01-01
The author has identified the following significant results. Large segments of the major high angle faults in the Salton Trough area are readily identifiable in Skylab images. Along active faults, distinctive topographic features such as scarps and offset drainage, and vegetation differences due to ground water blockage in alluvium are visible. Other fault-controlled features along inactive as well as active faults visible in Skylab photography include straight mountain fronts, linear valleys, and lithologic differences producing contrasting tone, color or texture. A northwestern extension of a fault in the San Andreas set, is postulated by the regional alignment of possible fault-controlled features. The suspected fault is covered by Holocene deposits, principally windblown sand. A northwest trending tonal change in cultivated fields across Mexicali Valley is visible on Skylab photos. Surface evidence for faulting was not observed; however, the linear may be caused by differences in soil conditions along an extension of a segment of the San Jacinto fault zone. No evidence of faulting could be found along linears which appear as possible extensions of the Substation and Victory Pass faults, demonstrating that the interpretation of linears as faults in small scale photography must be corroborated by field investigations.
NASA Astrophysics Data System (ADS)
Akintunde, Olusoga M.; Knapp, Camelia C.; Knapp, James H.
2014-09-01
A simple, new porosity/permeability-depth profile was developed from available laboratory measurements on Triassic sedimentary red beds (sandstone) from parts of the South Georgia Rift (SGR) basin in order to investigate the feasibility for long-term CO2 storage. The study locations were: Sumter, Berkeley, Dunbarton, Clubhouse Crossroad-3 (CC-3) and Norris Lightsey wells. As expected, both porosity and permeability show changes with depth at the regional scale that was much greater than at local scale. The significant changes in porosity and permeability with depth suggest a highly compacted, deformed basin, and potentially, a history of uplift and erosion. The permeability is generally low both at shallow (less than 1826 ft/556.56 m) and deeper depths (greater than 1826 ft/556.56 m). Both porosity and permeability follow the normal trend, decreasing linearly with depth for most parts of the study locations with the exception of the Norris Lightsey well. A petrophysical study on a suite of well logs penetrating the Norris Lightsey red beds at depths sampled by the core-derived laboratory measurements shows an abnormal shift (by 50%) in the acoustic travel time and/or in the sonic-derived P-wave velocity that indicates possible faulting or fracturing at depth. The departure of the Norris Lightsey's porosities and permeabilities from the normal compaction trend may be a consequence of the existence of a fault/fracture controlled abnormal pressure condition at depth. The linear and non-linear behaviors of the porosity/permeability distribution throughout the basin imply the composition of the SGR red beds, and by extension analog/similar Triassic-Jurassic formations within the Eastern North American Margin have been altered by compaction, uplift, erosion and possible faulting that have shaped the evolution of these Triassic formations following the major phase of rifting.
Trends in Physical Medicine and Rehabilitation Publications Over the Past 16 Years.
Mimouni, Michael; Cismariu-Potash, Keren; Ratmansky, Motti; Shaklai, Sharon; Amir, Hagay; Mimouni-Bloch, Aviva
2016-06-01
To test the hypothesis that the number of publications in the field of physical medicine and rehabilitation (PMR) has increased over the last 16 years in a linear fashion, and to compare the trends in publication between the pediatric and adult literature. We evaluated all MEDLINE articles from January 1, 1998, to December 31, 2013, using Medical Subject Headings categories of rehabilitation. An age filter separated adult and pediatric articles. We divided articles into those with a low level of scientific evidence such as letters and editorials, and those with a high level of evidence such as controlled trials and meta-analyses. We used regression analysis to evaluate the effect of the year of publication on the number of publications of each type. Not applicable. Not applicable. Not applicable. Not applicable. MEDLINE reported a total of 98,501 adult publications and 30,895 pediatric publications during the evaluated period. There was a significant linear increase in the total number of publications in adult and pediatric rehabilitation publications with multiplication factors of 3.3 and 2.9, respectively. Importantly, publications with a high level of evidence showed larger multiplication factors compared with those with a low level of evidence (5.5 and 5.1 vs 2.1 and 2.0) for the adult and pediatric literature. The number of publications in the PMR field, especially those with a high level of scientific evidence, has increased linearly over the years, reflecting the rapid evolution of both adult and pediatric PMR. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.
The Evolution of Dental Journals from 2003 to 2012: A Bibliometric Analysis
Jayaratne, Yasas Shri Nalaka; Zwahlen, Roger Arthur
2015-01-01
Bibliometrics are a set of methods, which can be used to analyze academic literature quantitatively and its changes over time. The objectives of this study were 1) to evaluate trends related to academic performance of dental journals from 2003 to 2012 using bibliometric indices, and 2) monitor the changes of the five dental journals with the highest and lowest impact factor (IF) published in 2003. Data for the subject category "Dentistry, Oral Surgery & Medicine" was retrieved from the Journal Citation Reports (JCR) published from 2003 to 2012. Linear regressions analysis was used to determine statistical trends over the years with each bibliometric indicator as the dependent variable and the JCR year as the predictor variable. Statistically significant rise in the total number of dental journals, the number of all articles with the steepest rise observed for research articles, the number of citations and the aggregate IF was observed from 2003 to 2012. The analysis of the five top and five bottom-tire dental journals revealed a rise in IF however, with a wide variation in relation to the magnitude of this rise. Although the IF of the top five journals remained relatively constant, the percentile ranks of the four lowest ranking journals in 2003 increased significantly with the sharpest rise being noted for the British Journal of Oral & Maxillofacial Surgery. This study revealed significant growth of dental literature in absolute terms, as well as upward trends for most of the citation-based bibliometric indices from 2003 to 2012. PMID:25781486
Gonadal status and physical performance in older men.
Maggio, Marcello; Ceda, Gian Paolo; Lauretani, Fulvio; Bandinelli, Stefania; Metter, Earl Jeffrey; Guralnik, Jack M; Basaria, Shehzad; Cattabiani, Chiara; Luci, Michele; Dall'Aglio, Elisabetta; Vignali, Alessandro; Volpi, Riccardo; Valenti, Giorgio; Ferrucci, Luigi
2011-03-01
To test the relationship between gonadal status and objective measures and determinants of physical performance in older men and their determinants. The study included 455 ≥ 65 year older men of InCHIANTI study, Italy, with complete data on testosterone levels, hand grip strength, cross-sectional muscle area (CSMA), short physical performance battery (SPPB). Linear models were used to test the relationship between gonadal status and determinants of physical performance. Three different groups of older men were created: (1) severely hypogonadal (N=23), total testosterone levels ≤ 230 ng /dl; (2) moderately hypogonadal (N=88), total testosterone >230 and < 350 ng/dl) and (3) eugonadal (N=344), testosterone levels ≥ 350 ng/dl. With increased severity of hypogonadal status, participants were significantly older while their BMI was substantially similar. In the age and BMI adjusted analysis, there was a significant difference in haemoglobin levels, hand grip strength and SPPB score (p for trend < 0.001) among three groups, with severely hypogonadal men having lower values of haemoglobin, muscle strength and physical performance. We found no association between testosterone group assignment and calf muscle mass and 4 m walking speed. In the multivariate analysis grip strength (p for trend = 0.004) and haemoglobin (p for trend < 0.0001) but not SPPB and other determinants of physical performance were significantly different between the three groups. In older men, gonadal status is independently associated with some determinants (haemoglobin and muscle strength) of physical performance.
The evolution of dental journals from 2003 to 2012: a bibliometric analysis.
Jayaratne, Yasas Shri Nalaka; Zwahlen, Roger Arthur
2015-01-01
Bibliometrics are a set of methods, which can be used to analyze academic literature quantitatively and its changes over time. The objectives of this study were 1) to evaluate trends related to academic performance of dental journals from 2003 to 2012 using bibliometric indices, and 2) monitor the changes of the five dental journals with the highest and lowest impact factor (IF) published in 2003. Data for the subject category "Dentistry, Oral Surgery & Medicine" was retrieved from the Journal Citation Reports (JCR) published from 2003 to 2012. Linear regressions analysis was used to determine statistical trends over the years with each bibliometric indicator as the dependent variable and the JCR year as the predictor variable. Statistically significant rise in the total number of dental journals, the number of all articles with the steepest rise observed for research articles, the number of citations and the aggregate IF was observed from 2003 to 2012. The analysis of the five top and five bottom-tire dental journals revealed a rise in IF however, with a wide variation in relation to the magnitude of this rise. Although the IF of the top five journals remained relatively constant, the percentile ranks of the four lowest ranking journals in 2003 increased significantly with the sharpest rise being noted for the British Journal of Oral & Maxillofacial Surgery. This study revealed significant growth of dental literature in absolute terms, as well as upward trends for most of the citation-based bibliometric indices from 2003 to 2012.
Firearm and nonfirearm homicide in 5 South African cities: a retrospective population-based study.
Matzopoulos, Richard G; Thompson, Mary Lou; Myers, Jonathan E
2014-03-01
We assessed the effectiveness of South Africa's Firearm Control Act (FCA), passed in 2000, on firearm homicide rates compared with rates of nonfirearm homicide across 5 South African cities from 2001 to 2005. We conducted a retrospective population-based study of 37 067 firearm and nonfirearm homicide cases. Generalized linear models helped estimate and compare time trends of firearm and nonfirearm homicides, adjusting for age, sex, race, day of week, city, year of death, and population size. There was a statistically significant decreasing trend regarding firearm homicides from 2001, with an adjusted year-on-year homicide rate ratio of 0.864 (95% confidence interval [CI] = 0.848, 0.880), representing a decrease of 13.6% per annum. The year-on-year decrease in nonfirearm homicide rates was also significant, but considerably lower at 0.976 (95% CI = 0.954, 0.997). Results suggest that 4585 (95% CI = 4427, 4723) lives were saved across 5 cities from 2001 to 2005 because of the FCA. Strength, timing and consistent decline suggest stricter gun control mediated by the FCA accounted for a significant decrease in homicide overall, and firearm homicide in particular, during the study period.
Striking Seasonality in the Secular Warming of the Northern Continents: Structure and Mechanisms
NASA Astrophysics Data System (ADS)
Nigam, S.; Thomas, N. P.
2017-12-01
The linear trend in twentieth-century surface air temperature (SAT)—a key secular warming signal— exhibits striking seasonal variations over Northern Hemisphere continents; SAT trends are pronounced in winter and spring but notably weaker in summer and fall. The SAT trends in historical twentieth-century climate simulations informing the Intergovernmental Panel for Climate Change's Fifth Assessment show varied (and often unrealistic) strength and structure, and markedly weaker seasonal variation. The large intra-ensemble spread of winter SAT trends in some historical simulations was surprising, especially in the context of century-long linear trends, with implications for the detection of the secular warming signal. The striking seasonality of observed secular warming over northern continents warrants an explanation and the representation of related processes in climate models. Here, the seasonality of SAT trends over North America is shown to result from land surface-hydroclimate interactions and, to an extent, also from the secular change in low-level atmospheric circulation and related thermal advection. It is argued that the winter dormancy and summer vigor of the hydrologic cycle over middle- to high-latitude continents permit different responses to the additional incident radiative energy from increasing greenhouse gas concentrations. The seasonal cycle of climate, despite its monotony, provides an expanded phase space for the exposition of the dynamical and thermodynamical processes generating secular warming, and an exceptional cost-effective opportunity for benchmarking climate projection models.
Climate change at upper treeline: How do trees on the edge react to increasing temperatures?
NASA Astrophysics Data System (ADS)
Jochner, Matthias; Bugmann, Harald; Nötzli, Magdalena; Bigler, Christof
2017-04-01
Treeline ecotones are thought to be particularly sensitive to climate warming, and an alteration of their growth conditions may have important implications for the ecosystem services they supply in mountain regions. We use a novel approach to quantify effects of a changing climate on tree growth, using case studies in the European Alps. We compiled tree-ring data from almost 600 trees of four species at treeline in three climate regions of Switzerland. Temperature loggers installed along transects provided data for a precise interpolation of temperatures experienced by the sampled trees. To assess the influence of temperature on annual growth, we used linear mixed-effects models, allowing us to quantify effect sizes and to account for between-tree growth variability. After removing biological growth trends, we isolated temporal trends of ring-width indices. Furthermore, we fitted non-linear regression models to radial growth rates of individual years with temperature and tree age as predicting covariates for a fine-scale investigation of the temperature dependency of tree growth. For all species, climate-growth linear mixed-effects models indicated strong positive responses of ring-width indices to temperature in early summer and previous year's autumn, featuring considerable between-tree variability. All species showed positive ring-width index trends at treeline but different interactions with elevation: Larix decidua exhibited a declining ring-width index trend with decreasing elevation, whereas Picea abies, Pinus cembra and Pinus mugo showed increasing and/or stable trends. Not only reflected our findings the effects of ameliorated growth conditions, they might have also revealed suspected negative and positive feedbacks of climate change on growth, and increased the knowledge about the functional form and parameterization of the temperature dependency of tree growth.
A decreasing trend in fall-related hip fracture incidence in Victoria, Australia.
Cassell, E; Clapperton, A
2013-01-01
In Victoria, Australia, the age-standardised incidence of fall-related hip fracture hospitalisations decreased significantly by 25% over the period 1998/1999-2008/2009. Significant decreases in fall-related hip fractures were observed in males and females, across all 5-year age groups, in Australian-born and overseas-born Victorians, in all socio-economic quintiles and in community-dwelling older people. The study aim was to investigate trends in the incidence of fall-related and hip fracture hospitalisations among Victorians aged 65 years and older overall and by age, gender, country of birth, socio-economic status (SES) and location of the event (home, residential care institution, etc.) over the 11-year period 1998/1999 to 2008/2009. Annual counts and age-standardised rates for fall-related hospitalisations among people aged 65 years and older were estimated using Victorian hospital admissions data. The statistical significance of changes in trends over time were analysed using a log-linear regression model of the rate data assuming a Poisson distribution of cases. Although the age-standardised incidence of fall-related hospitalisations increased significantly by 13% (95% confidence interval [CI], 9% to 18%) in Victoria, the age-standardised incidence of fall-related hip fracture hospitalisations decreased from 600/100,000 in 1998/1999 to 467/100,000 in 2008/2009 - an estimated overall reduction of 25% (95% CI, -29% to -22%). By contrast, the age-standardised incidence of fall-related hospitalisations for fractures at other body sites either increased significantly or showed no significant change. Significant decreases in fall-related hip fractures were observed in both males and females, across all 5-year age groups, in both Australian-born and overseas-born Victorians, in all socio-economic quintiles and in community-dwelling older people but not in people living in residential care facilities. Despite the downward trend in the age-standardised incidence of fall-related hip fractures in Victoria, the burden of fall-related and hip fracture hospitalisations on health care systems and the community is set to escalate due to the ageing of the Victorian population.
Pal, Rahul; Yang, Jinping; Ortiz, Daniel; Qiu, Suimin; Resto, Vicente; McCammon, Susan; Vargas, Gracie
2015-01-01
The epithelial-connective tissue interface (ECTI) plays an integral role in epithelial neoplasia, including oral squamous cell carcinoma (OSCC). This interface undergoes significant alterations due to hyperproliferating epithelium that supports the transformation of normal epithelium to precancers and cancer. We present a method based on nonlinear optical microscopy to directly assess the ECTI and quantify dysplastic alterations using a hamster model for oral carcinogenesis. Neoplastic and non-neoplastic normal mucosa were imaged in-vivo by both multiphoton autofluorescence microscopy (MPAM) and second harmonic generation microscopy (SHGM) to obtain cross-sectional reconstructions of the oral epithelium and lamina propria. Imaged sites were biopsied and processed for histopathological grading and measurement of ECTI parameters. An ECTI shape parameter was calculated based on deviation from the linear geometry (ΔLinearity) seen in normal mucosa was measured using MPAM-SHGM and histology. The ECTI was readily visible in MPAM-SHGM and quantitative shape analysis showed ECTI deformation in dysplasia but not in normal mucosa. ΔLinearity was significantly (p < 0.01) higher in dysplasia (0.41±0.24) than normal (0.11±0.04) as measured in MPAM-SHGM and results were confirmed in histology which showed similar trends in ΔLinearity. Increase in ΔLinearity was also statistically significant for different grades of dysplasia. In-vivo ΔLinearity measurement alone from microscopy discriminated dysplasia from normal tissue with 87.9% sensitivity and 97.6% specificity, while calculations from histology provided 96.4% sensitivity and 85.7% specificity. Among other quantifiable architectural changes, a progressive statistically significant increase in epithelial thickness was seen with increasing grade of dysplasia. MPAM-SHGM provides new noninvasive ways for direct characterization of ECTI which may be used in preclinical studies to investigate the role of this interface in early transformation. Further development of the method may also lead to new diagnostic approaches to differentiate non-neoplastic tissue from precancers and neoplasia, possibly with other cellular and layer based indicators of abnormality.
Noise Reduction of Ocean-Bottom Pressure Data Toward Real-Time Tsunami Forecasting
NASA Astrophysics Data System (ADS)
Tsushima, H.; Hino, R.
2008-12-01
We discuss a method of noise reduction of ocean-bottom pressure data to be fed into the near-field tsunami forecasting scheme proposed by Tsushima et al. [2008a]. In their scheme, the pressure data is processed in real time as follows: (1) removing ocean tide components by subtracting the sea-level variation computed from a theoretical tide model, (2) applying low-pass digital filter to remove high-frequency fluctuation due to seismic waves, and (3) removing DC-offset and linear-trend component to determine a baseline of relative sea level. However, it turns out this simple method is not always successful in extracting tsunami waveforms from the data, when the observed amplitude is ~1cm. For disaster mitigation, accurate forecasting of small tsunamis is important as well as large tsunamis. Since small tsunami events occur frequently, successful tsunami forecasting of those events are critical to obtain public reliance upon tsunami warnings. As a test case, we applied the data-processing described above to the bottom pressure records containing tsunami with amplitude less than 1 cm which was generated by the 2003 Off-Fukushima earthquake occurring in the Japan Trench subduction zone. The observed pressure variation due to the ocean tide is well explained by the calculated tide signals from NAO99Jb model [Matsumoto et al., 2000]. However, the tide components estimated by BAYTAP-G [Tamura et al., 1991] from the pressure data is more appropriate for predicting and removing the ocean tide signals. In the pressure data after removing the tide variations, there remain pressure fluctuations with frequencies ranging from about 0.1 to 1 mHz and with amplitudes around ~10 cm. These fluctuations distort the estimation of zero-level and linear trend to define relative sea-level variation, which is treated as tsunami waveform in the subsequent analysis. Since the linear trend is estimated from the data prior to the origin time of the earthquake, an artificial linear trend is produced in the processed waveform. This artificial linear trend degrades the accuracy of the tsunami forecasting, although the forecasting result is expected to be robust against the existence of short-period noise [Tsushima et al., 2008a]. Since the bottom pressure show gradual increase (or decrease) in the tsunami source region [Tsushima et al., 2008b], it is important to remove the linear trend not related to the tsunami generation from the data before fed into the analysis. Therefore, the reduction of the noise in sub-mHz band is critical for the forecasting small tsunamis. Applying a kind of frequency filters to eliminate this noise cannot be a solution for this problem because actual tsunami signals may also contain components of this frequency band. We investigate whether any statistical modelings of the noise are effective for reducing the sub-mHz noise.
Cronobiologic analysis of abortions in two related populations of teenager girls during two decades.
Mikulechý, M; Soltés, L; Valachová, A
1994-06-01
To identify and compare the time dynamics of artificial abortions in two (Czech and Slovak) ethnically, historically and socially closely related populations. Data have been taken separately for 12-15 and 16-18 year age girls from official exhaustive statistical sources and processed by advanced procedures of time series analysis. Czech and Slovak Republics. All girls of the given age. Legislative liberalization of abortions 1987. Estimated starting values of relative numbers of abortions by 1971, increasing linear trends, period lengths of fluctuation, coefficients of determination and those of cross-correlation. Level of significance alpha = 0.05. The Czech figures are significantly higher than the Slovak. Thus, estimated abortion percentage (from pregnancies) for 1971 was for younger Czech girls 53%, and for those from Slovakia 29%. All estimated trends were increasing significantly in all cases for the Czech population (by 1.5% per year in the younger group) and in one case for Slovakia. The estimated period lengths were usually 10-12 years. Czech and Slovak data display significant positive mutual cross-correlation, the delay being 1-3 years in Slovak girls. Surprisingly, all data significantly cross-correlate with the geomagnetic index value Ap, acting as lead-lag, with 3-6-year delay for abortions. Despite living in the same federal state--the former Czechoslovak Republic, both Czech and Slovak populations do differ in starting values and general trends of abortions in teenagers. This can be due to historical, racial and religious peculiarities as well as a more advanced process of industrialization in the western part--the Czech Republic. The latter hypothesis is corroborated by strong dynamism of changes and by the time delay in Slovakia. The periodicity exhibits a frequency resembling that known for solar motion round barycenter of solar system, for sunspots and geomagnetism.
Surface Ozone Variability and Trends over the South African Highveld from 1990 to 2007
NASA Technical Reports Server (NTRS)
Balashov, Nikolay V.; Thompson, Anne M.; Piketh, Stuart J.; Langerman, Kristy E.
2014-01-01
Surface ozone is a secondary air pollutant formed from reactions between nitrogen oxides (NOx = NO + NO2) and volatile organic compounds in the presence of sunlight. In this work we examine effects of the climate pattern known as the El Niño-Southern Oscillation (ENSO) and NOx variability on surface ozone from 1990 to 2007 over the South African Highveld, a heavily populated region in South Africa with numerous industrial facilities. Over summer and autumn (December-May) on the Highveld, El Niño, as signified by positive sea surface temperature (SST) anomalies over the central Pacific Ocean, is typically associated with drier and warmer than normal conditions favoring ozone formation. Conversely, La Niña, or negative SST anomalies over the central Pacific Ocean, is typically associated with cloudier and above normal rainfall conditions, hindering ozone production. We use a generalized regression model to identify any linear dependence that the Highveld ozone, measured at five air quality monitoring stations, may have on ENSO and NOx. Our results indicate that four out of the five stations exhibit a statistically significant sensitivity to ENSO at some point over the December-May period where El Niño amplifies ozone formation and La Niña reduces ozone formation. Three out of the five stations reveal statistically significant sensitivity to NOx variability, primarily in winter and spring. Accounting for ENSO and NOx effects throughout the study period of 18 years, two stations exhibit statistically significant negative ozone trends in spring, one station displays a statistically significant positive trend in August, and two stations show no statistically significant change in surface ozone.
Recurrent jellyfish blooms are a consequence of global oscillations
Condon, Robert H.; Duarte, Carlos M.; Pitt, Kylie A.; Robinson, Kelly L.; Lucas, Cathy H.; Sutherland, Kelly R.; Mianzan, Hermes W.; Bogeberg, Molly; Purcell, Jennifer E.; Decker, Mary Beth; Uye, Shin-ichi; Madin, Laurence P.; Brodeur, Richard D.; Haddock, Steven H. D.; Malej, Alenka; Parry, Gregory D.; Eriksen, Elena; Quiñones, Javier; Acha, Marcelo; Harvey, Michel; Arthur, James M.; Graham, William M.
2013-01-01
A perceived recent increase in global jellyfish abundance has been portrayed as a symptom of degraded oceans. This perception is based primarily on a few case studies and anecdotal evidence, but a formal analysis of global temporal trends in jellyfish populations has been missing. Here, we analyze all available long-term datasets on changes in jellyfish abundance across multiple coastal stations, using linear and logistic mixed models and effect-size analysis to show that there is no robust evidence for a global increase in jellyfish. Although there has been a small linear increase in jellyfish since the 1970s, this trend was unsubstantiated by effect-size analysis that showed no difference in the proportion of increasing vs. decreasing jellyfish populations over all time periods examined. Rather, the strongest nonrandom trend indicated jellyfish populations undergo larger, worldwide oscillations with an approximate 20-y periodicity, including a rising phase during the 1990s that contributed to the perception of a global increase in jellyfish abundance. Sustained monitoring is required over the next decade to elucidate with statistical confidence whether the weak increasing linear trend in jellyfish after 1970 is an actual shift in the baseline or part of an oscillation. Irrespective of the nature of increase, given the potential damage posed by jellyfish blooms to fisheries, tourism, and other human industries, our findings foretell recurrent phases of rise and fall in jellyfish populations that society should be prepared to face. PMID:23277544
Zheutlin, Alexander R; Adar, Sara D; Park, Sung Kyun
2014-12-01
Recent studies suggest that increasing levels of the greenhouse gas, carbon dioxide (CO2), may influence weight gain and thus may play a role in rising trends in obesity and diabetes. We conducted an ecological study to examine the associations between CO2 emissions from fossil fuel combustion and changes in the prevalence of obesity and diabetes in the United States. County-level data on CO2 emissions, prevalence of obesity and diagnosed diabetes, other sociodemographic factors and neighborhood characteristics related to urbanicity, and fine particles (PM2.5) between 2004 and 2008 were obtained from the Vulcan Project, Centers for Disease Control and Prevention, and American Community Survey. Linear mixed effect modeling of 3019 counties for the associations between average CO2 emissions and changes in diabetes and obesity prevalence between 2004 and 2008 was performed. The average obesity and diabetes prevalence increased between 2004 and 2008 by 3.65% (SD: 1.88%) and 1.65% (SD: 1.70%), respectively. A marginally significant positive association between CO2 emission and changes in obesity prevalence was found with adjustment for sociodemographic factors, indicators of urbanicity and spatial autocorrelation (p-trend=0.06). The association became weaker and nonsignificant with further adjustment for PM2.5 (p-trend=0.17). There was a significant positive association between CO2 emission and changes in diabetes prevalence before controlling for PM2.5 (p-trend=0.05) but the association became null after controlling for PM2.5 (p-trend=0.49), suggesting that PM2.5 is a critical confounder in the association between CO2 emission and changes in diabetes prevalence. This study does not support the hypothesis that CO2 emissions, a leading driver of climate change, may be linked to increasing trends in obesity and diabetes, though there was an indication of possible link between CO2 and obesity. Copyright © 2014 Elsevier Ltd. All rights reserved.
Sakai, Rie; Wang, Wei; Yamaguchi, Norihiro; Tamura, Hiroshi; Goto, Rei; Kawachi, Ichiro
2013-01-01
Inequity in physician distribution poses a challenge to many health systems. In Japan, a new postgraduate training program for all new medical graduates was introduced in 2004, and researchers have argued that this program has increased inequalities in physician distribution. We examined the trends in the geographic distribution of pediatricians as well as all physicians from 1996 to 2010 to identify the impact of the launch of the new training program. The Gini coefficient was calculated using municipalities as the study unit within each prefecture to assess whether there were significant changes in the intra-prefectural distribution of all physicians and pediatricians before and after the launch of the new training program. The effect of the new program was quantified by estimating the difference in the slope in the time trend of the Gini coefficients before and after 2004 using a linear change-point regression design. We categorized 47 prefectures in Japan into two groups: 1) predominantly urban and 2) others by the definition from OECD to conduct stratified analyses by urban-rural status. The trends in physician distribution worsened after 2004 for all physicians (p value<.0001) and pediatricians (p value = 0.0057). For all physicians, the trends worsened after 2004 both in predominantly urban prefectures (p value = 0.0012) and others (p value<0.0001), whereas, for pediatricians, the distribution worsened in others (p value = 0.0343), but not in predominantly urban prefectures (p value =0.0584). The intra-prefectural distribution of physicians worsened after the launch of the new training program, which may reflect the impact of the new postgraduate program. In pediatrics, changes in the Gini trend differed significantly before and after the launch of the new training program in others, but not in predominantly urban prefectures. Further observation is needed to explore how this difference in trends affects the health status of the child population.
Sakai, Rie; Wang, Wei; Yamaguchi, Norihiro; Tamura, Hiroshi; Goto, Rei; Kawachi, Ichiro
2013-01-01
Objective Inequity in physician distribution poses a challenge to many health systems. In Japan, a new postgraduate training program for all new medical graduates was introduced in 2004, and researchers have argued that this program has increased inequalities in physician distribution. We examined the trends in the geographic distribution of pediatricians as well as all physicians from 1996 to 2010 to identify the impact of the launch of the new training program. Methods The Gini coefficient was calculated using municipalities as the study unit within each prefecture to assess whether there were significant changes in the intra-prefectural distribution of all physicians and pediatricians before and after the launch of the new training program. The effect of the new program was quantified by estimating the difference in the slope in the time trend of the Gini coefficients before and after 2004 using a linear change-point regression design. We categorized 47 prefectures in Japan into two groups: 1) predominantly urban and 2) others by the definition from OECD to conduct stratified analyses by urban-rural status. Results The trends in physician distribution worsened after 2004 for all physicians (p value<.0001) and pediatricians (p value = 0.0057). For all physicians, the trends worsened after 2004 both in predominantly urban prefectures (p value = 0.0012) and others (p value<0.0001), whereas, for pediatricians, the distribution worsened in others (p value = 0.0343), but not in predominantly urban prefectures (p value = 0.0584). Conclusion The intra-prefectural distribution of physicians worsened after the launch of the new training program, which may reflect the impact of the new postgraduate program. In pediatrics, changes in the Gini trend differed significantly before and after the launch of the new training program in others, but not in predominantly urban prefectures. Further observation is needed to explore how this difference in trends affects the health status of the child population. PMID:24204731
Dry spell trend analysis in Kenya and the Murray Darling Basin using daily rainfall
NASA Astrophysics Data System (ADS)
Muita, R. R.; van Ogtrop, F. F.; Vervoort, R. W.
2012-04-01
Important agricultural areas in Kenya and the Murray Darling Basin (MDB) in Australia are largely semi-arid to arid. Persistent dry periods and timing of dry spells directly impact the availability of soil moisture and hence crop production in these regions. Most studies focus on the analysis of dry spell lengths at an annual scale. However, timing and length of dry spells at finer temporal scales is more beneficial for cropping when considering a trade-off between the time scale and the ability to analyse dry spell length. The aim of this study was to analyse the interannual and intra annual variations in dry spell lengths in the regions to inform crop management. This study analysed monthly dry spells based on daily rainfall for 1961-2010 on a limited dataset of 13 locations in Kenya and 17 locations in the MDB. This dataset was the most consistent across both regions and future analysis will incorporate more stations and longer time periods where available. Dry spell lengths were analysed by month and year and trends in monthly and annual dry spell lengths were analysed using Generalised Linear Models (GLM) and the Mann Kendall test (MK). Overall, monthly dryspell lengths are right skewed with higher frequency of shorter dryspells (3-25 days). In Kenya, significant increases in mean dry spell lengths (p≤0.02) are observed in inland arid-to semi humid locations but this temporal trend appears to decrease in highland and the coastal regions. Analysis of the MDB stations suggests changes in seasonality. For example, spatial trends suggest a North-South increase in dry spell length in summer (December - February), but a shortening after February. Generally, the GLM and MK results are similar in the two regions but the MK test tends to give higher values of positive slope coefficients and lower values for negative coefficients compared to GLM. This may limit the ability of finding the best estimates for model coefficients. Previous studies in Australia and Kenya have relied on continuous climatic indices based on global climate models and stochastic processes resulting in limited and mixed results. For agronomical purposes, our results show that direct assessment of dry spells lengths from daily rainfall also indicates changes in dry spells trends in Kenya and the MDB and that such an analysis is easy to use and requires limited assumptions. This initial analysis identifies significant increasing trends in the dry spell lengths in some areas and periods in Kenya and the MDB. This has major implications for crop production in these regions and it is recommended that this information be incorporated in the regions' management decisions. KEY WORDS: monthly dry spell length; Generalized Linear Models; Mann -Kendall test; month; Kenya, Murray Darling Basin (MDB).
Ontogenetic patterns in the dreams of women across the lifespan.
Dale, Allyson; Lortie-Lussier, Monique; De Koninck, Joseph
2015-12-01
The present study supports and extends previous research on the developmental differences in women's dreams across the lifespan. The participants included 75 Canadian women in each of 5 age groups from adolescence to old age including 12-17, 18-24, 25-39, 40-64, and 65-85, totaling 375 women. One dream per participant was scored by two independent judges using the method of content analysis. Trend analysis was used to determine the ontogenetic pattern of the dream content categories. Results demonstrated significant ontogenetic decreases (linear trends) for female and familiar characters, activities, aggression, and friendliness. These patterns of dream imagery reflect the waking developmental patterns as proposed by social theories and recognized features of aging as postulated by the continuity hypothesis. Limitations and suggestions for future research including the examining of developmental patterns in the dreams of males are discussed. Copyright © 2015 Elsevier Inc. All rights reserved.
Free-piston Stirling engine/linear alternator 1000-hour endurance test
NASA Technical Reports Server (NTRS)
Rauch, J.; Dochat, G.
1985-01-01
The Free Piston Stirling Engine (FPSE) has the potential to be a long lived, highly reliable, power conversion device attractive for many product applications such as space, residential or remote site power. The purpose of endurance testing the FPSE was to demonstrate its potential for long life. The endurance program was directed at obtaining 1000 operational hours under various test conditions: low power, full stroke, duty cycle and stop/start. Critical performance parameters were measured to note any change and/or trend. Inspections were conducted to measure and compare critical seal/bearing clearances. The engine performed well throughout the program, completing more than 1100 hours. Hardware inspection, including the critical clearances, showed no significant change in hardware or clearance dimensions. The performance parameters did not exhibit any increasing or decreasing trends. The test program confirms the potential for long life FPSE applications.
Recent Enrollment Trends in American Soil Science Programs
NASA Astrophysics Data System (ADS)
Brevik, Eric C.; Abit, Sergio; Brown, David; Dolliver, Holly; Hopkins, David; Lindbo, David; Manu, Andrew; Mbila, Monday; Parikh, Sanjai J.; Schulze, Darrell; Shaw, Joey; Weil, Ray; Weindorf, David
2015-04-01
Soil science student enrollment was on the decline in the United States from the early 1990s through the early 2000s. Overall undergraduate student enrollment in American colleges and universities rose by about 11% over the same time period. This fact created considerable consternation among the American soil science community. As we head into the International Year of Soil, it seemed to be a good time to revisit this issue and examine current enrollment trends. Fourteen universities that offer undergraduate and/or graduate programs in soil science were surveyed for their enrollments over the time period 2007-2014 (the last seven academic years). The 14 schools represent about 20% of the institutions that offer soil science degrees/programs in the United States. Thirteen institutions submitted undergraduate data and 10 submitted graduate data, which was analyzed by individual institution and in aggregate. Simple linear regression was used to find the slope of best-fit trend lines. For individual institutions, a slope of ≥ 0.5 (on average, the school gained 0.5 students per year or more) was considered to be growing enrollment, ≤ -0.5 was considered shrinking enrollment, and between -0.5 and 0.5 was considered to be stable enrollment. For aggregated data, the 0.5 slope standard was multiplied by the number of schools in the aggregated survey to determine whether enrollment was growing, shrinking, or stable. Over the period of the study, six of the 13 schools reporting undergraduate data showed enrollment gains, five of the 13 showed stable enrollments, one of the 13 showed declining enrollments, and one of the 13 discontinued their undergraduate degree program. The linear regression trend line for the undergraduate schools' composite data had a slope of 55.0 students/year (R2 = 0.96), indicating a strong overall trend of undergraduate enrollment growth at these schools. However, the largest school had also seen large growth in enrollment. To ensure that this one institution was not masking an overall declining enrollment trend, the regression was also run with that institution removed. This gave a linear trend line with a slope of 6.6 students/year (R2 = 0.90), indicating more moderate growth but still a trend towards growth in undergraduate enrollment. Four of the 10 graduate programs showed enrollment gains, five of the 10 showed stable enrollments, and one of the 10 showed declining enrollments. The linear regression trend line for the composite graduate school data had a slope of 12.0 students/year (R2 = 0.97), indicating an overall trend of enrollment growth at these schools. As a whole, both the undergraduate and graduate programs investigated showed moderate growth trends, which represent a reversal of enrollment trends reported at the beginning of the 21st Century. Challenges in obtaining the data used for this study included 1) differences in data collection and archiving by institutions and 2) only some schools still offer a soil science degree; many schools offer another degree (e.g., agricultural studies, agronomy, environmental resource science, environmental science, plant and soil science, etc.) with a soils option or emphasis. In the second case it was necessary to identify which students in these other degree programs pursued the soil science option or emphasis.
Changes in the timing of snowmelt and streamflow in Colorado: A response to recent warming
Clow, David W.
2010-01-01
Trends in the timing of snowmelt and associated runoff in Colorado were evaluated for the 1978-2007 water years using the regional Kendall test (RKT) on daily snow-water equivalent (SWE) data from snowpack telemetry (SNOTEL) sites and daily streamflow data from headwater streams. The RKT is a robust, nonparametric test that provides an increased power of trend detection by grouping data from multiple sites within a given geographic region. The RKT analyses indicated strong, pervasive trends in snowmelt and streamflow timing, which have shifted toward earlier in the year by a median of 2-3 weeks over the 29-yr study period. In contrast, relatively few statistically significant trends were detected using simple linear regression. RKT analyses also indicated that November-May air temperatures increased by a median of 0.9 degrees C decade-1, while 1 April SWE and maximum SWE declined by a median of 4.1 and 3.6 cm decade-1, respectively. Multiple linear regression models were created, using monthly air temperatures, snowfall, latitude, and elevation as explanatory variables to identify major controlling factors on snowmelt timing. The models accounted for 45% of the variance in snowmelt onset, and 78% of the variance in the snowmelt center of mass (when half the snowpack had melted). Variations in springtime air temperature and SWE explained most of the interannual variability in snowmelt timing. Regression coefficients for air temperature were negative, indicating that warm temperatures promote early melt. Regression coefficients for SWE, latitude, and elevation were positive, indicating that abundant snowfall tends to delay snowmelt, and snowmelt tends to occur later at northern latitudes and high elevations. Results from this study indicate that even the mountains of Colorado, with their high elevations and cold snowpacks, are experiencing substantial shifts in the timing of snowmelt and snowmelt runoff toward earlier in the year.
Feng, Chao-Hui; Drummond, Liana; Zhang, Zhi-Hang; Sun, Da-Wen
2013-10-01
The effects of agitation (1002 rpm), different pressure reduction rates (60 and 100 mbar/min), as well as employing cold water with different initial temperatures (IWT: 7 and 20°C) on immersion vacuum cooling (IVC) of cooked pork hams were experimentally investigated. Final pork ham core temperature, cooling time, cooling loss, texture properties, colour and chemical composition were evaluated. The application for the first time of agitation during IVC substantially reduced the cooling time (47.39%) to 4.6°C, compared to IVC without agitation. For the different pressure drop rates, there was a trend that shorter IVC cooling times were achieved with lower cooling rate, although results were not statistically significant (P>0.05). For both IWTs tested, the same trend was observed: shorter cooling time and lower cooling loss were obtained under lower linear pressure drop rate of 60 mbar/min (not statistically significant, P>0.05). Compared to the reference cooling method (air blast cooling), IVC achieved higher cooling rates and better meat quality. Copyright © 2013 Elsevier Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Boers, Reinout; Brandsma, Theo; Pier Siebesma, A.
2017-07-01
A 50-year hourly data set of global shortwave radiation, cloudiness and visibility over the Netherlands was used to quantify the contribution of aerosols and clouds to the trend in yearly-averaged all-sky radiation (1.81 ± 1.07 W m-2 decade-1). Yearly-averaged clear-sky and cloud-base radiation data show large year-to-year fluctuations caused by yearly changes in the occurrence of clear and cloudy periods and cannot be used for trend analysis. Therefore, proxy clear-sky and cloud-base radiations were computed. In a proxy analysis hourly radiation data falling within a fractional cloudiness value are fitted by monotonic increasing functions of solar zenith angle and summed over all zenith angles occurring in a single year to produce an average. Stable trends can then be computed from the proxy radiation data. A functional expression is derived whereby the trend in proxy all-sky radiation is a linear combination of trends in fractional cloudiness, proxy clear-sky radiation and proxy cloud-base radiation. Trends (per decade) in fractional cloudiness, proxy clear-sky and proxy cloud-base radiation were, respectively, 0.0097 ± 0.0062, 2.78 ± 0.50 and 3.43 ± 1.17 W m-2. To add up to the all-sky radiation the three trends have weight factors, namely the difference between the mean cloud-base and clear-sky radiation, the clear-sky fraction and the fractional cloudiness, respectively. Our analysis clearly demonstrates that all three components contribute significantly to the observed trend in all-sky radiation. Radiative transfer calculations using the aerosol optical thickness derived from visibility observations indicate that aerosol-radiation interaction (ARI) is a strong candidate to explain the upward trend in the clear-sky radiation. Aerosol-cloud interaction (ACI) may have some impact on cloud-base radiation, but it is suggested that decadal changes in cloud thickness and synoptic-scale changes in cloud amount also play an important role.
Increasing trend in the average temperature in Finland, 1847-2012
NASA Astrophysics Data System (ADS)
Mikkonen, Santtu; Laine, Marko; Mäkelä, Hanna M.; Gregow, Hilppa; Tuomenvirta, Heikki; Lahtinen, Matti; Laaksonen, Ari
2014-05-01
The global average temperature has increased by about 0.8 ° C since the mid-19th century. It has been shown that this increase is statistically significant and that it can, for the most part, be attributed to human-induced climate change (IPCC 2007). A temperature increase is obvious also in regional and local temperatures in many parts of the world. However, compared with the global average temperature, the regional and local temperatures exhibit higher levels of noise, which has largely been removed from the global temperature due to the higher level of averaging. Because Finland is located in northern latitudes, it is subject to the polar amplification of climate change-induced warming, which is due to the enhanced melting of snow and ice and other feedback mechanisms. Therefore, warming in Finland is expected to be approximately 50% higher than the global average. Conversely, the location of Finland between the Atlantic Ocean and continental Eurasia causes the weather to be very variable, and thus the temperature signal is rather noisy. The change in mean temperature in Finland was investigated with Dynamic Linear Models (DLM) in order to define the sign and the magnitude of the trend in the temperature time series within the last 165 years. The data consisted of gridded monthly mean temperatures. The grid has a 10 km spatial resolution, and it was created by interpolating a homogenized temperature series measured at Finnish weather stations. Seasonal variation in temperature and the autocorrelation structure of the time series were taken account in the DLM models. We found that the Finnish temperature time series exhibits a statistically significant increasing trend, which is consistent with human-induced global warming. The mean temperature has risen clearly over 2° C in the years 1847-2012, which amounts to 0.16 ° C/decade. The warming rate before 1940's was close to the linear trend for the whole period, whereas the temperature change in the mid-20th century was negligible. However, the warming after the late 1960s has been remarkably fast. The model indicates that within the last 40 years the rate of change has been as high as 0.30 ° C/decade. The increase in temperature has been highest in spring and in late autumn but the change in summer months has not been so evident. The observed warming is somewhat higher than the global trend, which confirms the assumption that warming is stronger in higher latitudes.
NASA Astrophysics Data System (ADS)
Thompson, D. M.; Evans, M. N.; Cole, J. E.; Ault, T. R.; Emile-Geay, J.
2011-12-01
The response of the tropical Pacific Ocean to anthropogenic climate change remains highly uncertain, in part because of the disagreement among 20th-century trends derived from observations and coupled general circulation models (CGCMs). We use a model of reef coral oxygen isotopic composition (δ18O) to compare the observational coral network with synthetic corals ('pseudocorals') modeled from CGCM sea-surface temperature (SST) and sea-surface salinity (SSS). When driven with historical data, we found that a linear temperature and salinity driven model for δ18Ocoral was able to capture the spatial and temporal pattern of ENSO and the linear trend observed in 23 Indo-Pacific coral records between 1958 and 1990. However, we found that none of the pseudocoral networks obtained from a subset of 20th-century AR4 CGCM runs reproduced the magnitude of the secular trend, the change in mean state, or the change in ENSO-related variance observed in the coral network from 1890 to 1990 (Thompson et al., 2011). We believe differences between corals and AR4 CGCM simulated pseudocorals arose from uncertainties in the observed coral network or linear bivariate coral model, undersensitivity of AR4 CGCMs to radiative forcing during the 20th century, and/or biases in the simulated AR4 CGCM SSS fields. Here we apply the same approach to an extended temperature and salinity reanalysis product (SODA v2.2.4, 1871-2008) and CMIP 5 historical simulations to further address 20th-century tropical climate trends and assess remaining uncertainties in both the proxies and models. We explore whether model improvements in the tropical Pacific have led to a stronger agreement between simulated and observed tropical climate trends. [Thompson, D. M., T. R. Ault, M. N. Evans, J. E. Cole, and J. Emile-Geay (2011), Comparison of observed and simulated tropical climate trends using a forward model of coral δ18O, Geophys. Res. Lett., 38, L14706, doi:10.1029/2011GL048224.
Recovery Trends in Marine Mammal Populations
Magera, Anna M.; Mills Flemming, Joanna E.; Kaschner, Kristin; Christensen, Line B.; Lotze, Heike K.
2013-01-01
Marine mammals have greatly benefitted from a shift from resource exploitation towards conservation. Often lauded as symbols of conservation success, some marine mammal populations have shown remarkable recoveries after severe depletions. Others have remained at low abundance levels, continued to decline, or become extinct or extirpated. Here we provide a quantitative assessment of (1) publicly available population-level abundance data for marine mammals worldwide, (2) abundance trends and recovery status, and (3) historic population decline and recent recovery. We compiled 182 population abundance time series for 47 species and identified major data gaps. In order to compare across the largest possible set of time series with varying data quality, quantity and frequency, we considered an increase in population abundance as evidence of recovery. Using robust log-linear regression over three generations, we were able to classify abundance trends for 92 spatially non-overlapping populations as Significantly Increasing (42%), Significantly Decreasing (10%), Non-Significant Change (28%) and Unknown (20%). Our results were comparable to IUCN classifications for equivalent species. Among different groupings, pinnipeds and other marine mammals (sirenians, polar bears and otters) showed the highest proportion of recovering populations, likely benefiting from relatively fast life histories and nearshore habitats that provided visibility and protective management measures. Recovery was less frequent among cetaceans, but more common in coastal than offshore populations. For marine mammals with available historical abundance estimates (n = 47), larger historical population declines were associated with low or variable recent recoveries so far. Overall, our results show that many formerly depleted marine mammal populations are recovering. However, data-deficient populations and those with decreasing and non-significant trends require attention. In particular, increased study of populations with major data gaps, including offshore small cetaceans, cryptic species, and marine mammals in low latitudes and developing nations, is needed to better understand the status of marine mammal populations worldwide. PMID:24205025
Cho, Yeoungjee; Büchel, Janine; Steppan, Sonja; Passlick-Deetjen, Jutta; Hawley, Carmel M.; Dimeski, Goce; Clarke, Margaret; Johnson, David W.
2016-01-01
♦ Background: The longitudinal trends of lipid parameters and the impact of biocompatible peritoneal dialysis (PD) solutions on these levels remain to be fully defined. The present study aimed to a) evaluate the influence of neutral pH, low glucose degradation product (GDP) PD solutions on serum lipid parameters, and b) explore the capacity of lipid parameters (total cholesterol [TC], triglyceride [TG], high density lipoprotein [HDL], TC/HDL, low density lipoprotein [LDL], very low density lipoprotein [VLDL]) to predict cardiovascular events (CVE) and mortality in PD patients. ♦ Methods: The study included 175 incident participants from the balANZ trial with at least 1 stored serum sample. A composite CVE score was used as a primary clinical outcome measure. Multilevel linear regression and Poisson regression models were fitted to describe the trend of lipid parameters over time and its ability to predict composite CVE, respectively. ♦ Results: Small but statistically significant increases in serum TG (coefficient 0.006, p < 0.001), TC/HDL (coefficient 0.004, p = 0.001), and VLDL cholesterol (coefficient 0.005, p = 0.001) levels and a decrease in the serum HDL cholesterol levels (coefficient −0.004, p = 0.009) were observed with longer time on PD, whilst the type of PD solution (biocompatible vs standard) received had no significant effect on these levels. Peritoneal dialysis glucose exposure was significantly associated with trends in TG, TC/HDL, HDL and VLDL levels. Baseline lipid parameter levels were not predictive of composite CVEs or all-cause mortality. ♦ Conclusion: Serum TG, TC/HDL, and VLDL levels increased and the serum HDL levels decreased with increasing PD duration. None of the lipid parameters were significantly modified by biocompatible PD solution use over the time period studied or predictive of composite CVE or mortality. PMID:26429421
Ein-Mor, Eliana; Ergaz-Shaltiel, Zivanit; Berman, Tamar; Göen, Thomas; Natsheh, Juma; Ben-Chetrit, Avraham; Haimov-Kochman, Ronit; Calderon-Margalit, Ronit
2018-06-01
Maternal urinary levels of dialkyl phosphate (DAP) metabolites of organophosphate pesticides (OP) during pregnancy are associated with adverse outcomes in the offspring. Between 2012 and 2014, eighteen active OP ingredients were restricted or banned in Israel for agricultural use. We aimed to study trends of urinary DAP metabolites among pregnant women and their offspring in the era of the new regulations. Pregnant women were recruited at 11-18 weeks of gestation and provided spot urine samples (n = 273). Soon after birth, neonatal urine samples were collected (n = 107). All urine specimens analyzed for DAP metabolites. Trends in DAP metabolites were tested using Mann-Kendall trend statistic (M-K S) and linear regression models were constructed to estimate the association between calendar period and DAP levels between September 2012 and March 2016. Over the study period, median maternal ∑DAP levels decreased from 248 nmol/L to 148 nmol/L. Time of recruitment was associated with a statistically significant decrease in DAP metabolites, which remained significant after multivariate adjustment. Overall, the results for the analysis of before and after June 2014 showed a significant decrease in ∑DAP of -0.198 log10 nmol/L (95%CI: -0.311,-0.084) which corresponds with a decrease of 36.6% in ∑DAP. A similar trend was found for DAP metabolites in neonatal urine. Compared to other studies, pregnant women in Jerusalem had higher ∑DAP levels, even at the end of the study period. We observed significant reductions in maternal and neonatal DAP urinary levels during the period of 2012-2016. Regulations restricting agricultural use of OP seem to be effective in reducing population exposure to OP, in an era when residential use of OP is banned. Copyright © 2018 Elsevier GmbH. All rights reserved.
NASA Astrophysics Data System (ADS)
Serventi, Giovanna; Carli, Cristian; Sgavetti, Maria
2015-07-01
Among the techniques to detect planet's mineralogical composition remote sensing, visible and near-infrared (VNIR) reflectance spectroscopy is a powerful tool, because crystal field absorption bands are related to particular transitional metals in well-defined crystal structures, e.g., Fe2+ in M1 and M2 sites of olivine (OL) or pyroxene (PX). Although OL, PX and their mixtures have been widely studied, plagioclase (PL), considered a spectroscopically transparent mineral, has been poorly analyzed. In this work we quantitatively investigate the influence of plagioclase absorption band on the absorption bands of Fe, Mg minerals using the Modified Gaussian Model - MGM (Sunshine, J.M. et al. [1990]. J. Geophys. Res. 95, 6955-6966). We consider three plagioclase compositions of varying FeO wt.% contents and five mafic end-members (1) 56% orthopyroxene and 44% clinopyroxene, (2) 28% olivine and 72% orthopyroxene, (3) 30% orthopyroxene and 70% olivine, (4) 100% olivine and (5) 100% orthopyroxene, at two different particle sizes. The spectral parameters considered here are: band depth, band center, band width, c0 (the continuum intercept) and c1 (the continuum offset). In particular, we show the variation of the plagioclase and composite (plagioclase-olivine) band spectral parameters versus the volumetric iron content related to the plagioclase abundance in mixtures. Generally, increasing the vol. FeO% due to the PL: (1) 1250 nm band deepens with linear trend in mixtures with pyroxenes, while it decreases in mixtures with olivine, with trend shifting from parabolic to linear increasing the olivine content in end-member; (2) 1250 nm band center moves towards longer wavelengths with linear trend in pyroxene-rich mixtures and parabolic trend in olivine-rich mixtures; and (3) 1250 nm band clearly widens with linear trend in olivine-free mixtures, while the widening is only slight in olivine-rich mixtures. We also outline how spectral parameters can be ambiguous leading to an incorrect mineralogical interpretation. Furthermore, we show the presence of an asymmetry of the plagioclase band towards the IR region, resolvable adding a Gaussian in the 1600-1800 nm spectral region.
Assessment of SAGE Version 6.1 Ozone Data Quality
NASA Technical Reports Server (NTRS)
Wang, Hsiang J.; Cunnold, Derek M.; Thomason, Larry W.; Zawodny, Joseph M.; Bodeker, Greg E.
2002-01-01
The SAGE-II V6.1 ozone retrievals are shown to be of better precision at all levels and to be much more accurate than previous retrievals in the lower stratosphere below 20 km altitude. A filtering procedure for removing anomalous ozone profiles associated with volcanic aerosol/cloud effects and other identified artifacts in V6.1 ozone is described. The agreement between SAGE and ozonesondes in the mean is shown to be approximately 10% down to the tropopause. Relative to the sondes SAGE tends to slightly overestimate ozone (less than 5%) between 15 and 20 km altitude, and systematically underestimates ozone in the troposphere by approximately 30% in the regions between 8 km altitude and 2 km below the tropopause. The precisions (random errors) of SAGE ozone retrievals above 25 km altitude are estimated to be 4% or better; they are a factor of ten worse below 16 km altitude. Linear trends in the differences between coincident SAGE and ozonesondes measurement are generally less than 0.3 %/year and not significantly different from zero in 95% confidence intervals. Compared to V5.96 retrievals, ozone trend differences between 20 and 50 km altitude are approximately 0. 1 %/year, below 20 km altitude the SAGE II trends are more positive by approximately 0.2 %/year. For the 1984-1999 period the SAGE-II shows a localized ozone loss of -0.4(+/- 0.25) %/year (2gigma) in the tropics at 20 km altitude. In the lower stratosphere between 16 and 22 km altitudes, the SAGE shows significant ozone losses in the mid-latitudes in both Hemispheres during the 1979-1999 periods. The ozone trends range from -0.24(+/- 0.18) to -0.77(+/- 0.46) (2sigma)%/year. However in the 1984-1999 period, the downward trends are smaller (-0.07 to - 0.25 %/year) in this altitude range, and the trends in the integrated column from 12 to 17 km altitude in mid-latitudes (35 deg - 60 deg) are not significantly different from zero (0.1 +?- 0.6 (2sigma)%/year). Averaged over the tropics (20 deg S to 20 deg N) the ozone column above 15 km altitude exhibit a trend of -0.12 +/- 0.08 (2sigma)%/year.
OMI air-quality monitoring over the Middle East
NASA Astrophysics Data System (ADS)
Barkley, Michael P.; González Abad, Gonzalo; Kurosu, Thomas P.; Spurr, Robert; Torbatian, Sara; Lerot, Christophe
2017-04-01
Using Ozone Monitoring Instrument (OMI) trace gas vertical column observations of nitrogen dioxide (NO2), formaldehyde (HCHO), sulfur dioxide (SO2), and glyoxal (CHOCHO), we have conducted a robust and detailed time series analysis to assess changes in local air quality for over 1000 locations (focussing on urban, oil refinery, oil port, and power plant targets) over the Middle East for 2005-2014. Apart from NO2, which is highest over urban locations, average tropospheric column levels of these trace gases are highest over oil ports and refineries. The highest average pollution levels over urban settlements are typically in Bahrain, Kuwait, Qatar, and the United Arab Emirates. We detect 278 statistically significant and real linear NO2 trends in total. Over urban areas NO2 increased by up to 12 % yr-1, with only two locations showing a decreasing trend. Over oil refineries, oil ports, and power plants, NO2 increased by about 2-9 % yr-1. For HCHO, 70 significant and real trends were detected, with HCHO increasing by 2-7 % yr-1 over urban settlements and power plants and by about 2-4 % yr-1 over refineries and oil ports. Very few SO2 trends were detected, which varied in direction and magnitude (23 increasing and 9 decreasing). Apart from two locations where CHOCHO is decreasing, we find that glyoxal tropospheric column levels are not changing over the Middle East. Hence, for many locations in the Middle East, OMI observes a degradation in air quality over 2005-2014. This study therefore demonstrates the capability of OMI to generate long-term air-quality monitoring at local scales over this region.
Sugiyama, Shinichi; Okuda, Masayuki; Sasaki, Satoshi; Kunitsugu, Ichiro; Hobara, Tatsuya
2012-09-01
To investigate breakfast eating habits on daily energy and fish, vegetable, and fruit intake in Japanese adolescents. This study was completed as part of the Shunan Child Health Cohort Study. Two types of questionnaires, one on lifestyle habits and the other a brief-type, self-administered questionnaire on diet history, were administered to second-year junior high school students (1,876 boys and 1,759 girls) in Shunan City, Yamaguchi, Japan. The different breakfast habits were compared using the general linear model and the estimated means and P value for trend were calculated, with energy-adjusted food intake as the dependent variable and body mass index, gender, age, residential areas, and living status as covariates. In both males and females, the proportion of those who ate breakfast irregularly was about 10%. The daily intake of fish, vegetables, and fruit was significantly higher in those who ate breakfast with their guardians than in those who ate breakfast alone (P for trend <0.01). The daily intake of fish, seafood, and vegetables was significantly higher in those who less frequently ate cooked foods for breakfast (P for trend <0.01). Those who ate rice more frequently than bread at breakfast had a higher daily intake of fish, seafood, and vegetables (P for trend <0.01). Eating breakfast with the family, reducing the intake of cooked foods at breakfast, and eating breakfast with rice as a main staple food are suggested to contribute to an improved quality of diet in adolescents.
Scherb, Hagen; Voigt, Kristina
2011-06-01
Ever since the discovery of the mutagenic properties of ionizing radiation, the possibility of birth sex odds shifts in exposed human populations was considered in the scientific community. Positive evidence, however weak, was obtained after the atomic bombing of Japan. We previously investigated trends in the sex odds before and after the Chernobyl Nuclear Power Plant accident. In a pilot study, combined data from the Czech Republic, Denmark, Finland, Germany, Hungary, Norway, Poland, and Sweden between 1982 and 1992 showed a downward trend in the sex odds and a significant jump in 1987, the year immediately after Chernobyl. Moreover, a significant positive association of the sex odds between 1986 and 1991 with Chernobyl fallout at the district level in Germany was observed. Both of these findings, temporality (effect after exposure) and dose response association, yield evidence of causality. The primary aim of this study was to investigate longer time periods (1950-2007) in all of Europe and in the USA with emphasis on the global atmospheric atomic bomb test fallout and on the Chernobyl accident. To obtain further evidence, we also analyze sex odds data near nuclear facilities in Germany and Switzerland. DATA AND STATISTICAL METHODS: National gender-specific annual live births data for 39 European countries from 1975 to 2007 were compiled using the pertinent internet data bases provided by the World Health Organization, United Nations, Council of Europe, and EUROSTAT. For a synoptic re-analysis of the period 1950 to 1990, published data from the USA and from a predominantly western and less Chernobyl-exposed part of Europe were studied additionally. To assess spatial, temporal, as well as spatial-temporal trends in the sex odds and to investigate possible changes in those trends after the atomic bomb tests, after Chernobyl, and in the vicinity of nuclear facilities, we applied ordinary linear logistic regression. Region-specific and eventually changing spatial-temporal trends were analyzed using dummy variables coding for continents, countries, districts, municipalities, time periods, and appropriate spatial-temporal interactions. The predominantly western European sex odds trend together with the US sex odds trend (1950-1990 each) show a similar behavior. Both trends are consistent with a uniform reduction from 1950 to 1964, an increase from 1964 to 1975 that may be associated with delayed global atomic bomb test fallout released prior to the Partial Test Ban Treaty in 1963 and again a more or less constant decrease from 1975 to 1990. In practically all of Europe, including eastern European countries, from 1975 to 1986, and in the USA from 1975 to 2002, there were highly significant uniform downward trends in the sex odds with a reduction of 0.22% to 0.25% per 10 years. In contrast to the USA, in Europe there was a highly significant jump of the sex odds of 0.20% in the year 1987 following Chernobyl. From 1987 to 2000, the European sex odds trend reversed its sign and went upward, highly significantly so, with 0.42% per 10 years relative to the downward trend before Chernobyl. The global secular trend analyses are corroborated by the analysis of spatial-temporal sex odds trends near nuclear facilities (NF) in Germany and Switzerland. Within 35 km distance from those NF, the sex odds increase significantly in the range of 0.30% to 0.40% during NF operating time. The atmospheric atomic bomb test fallout affected the human sex odds at birth overall, and the Chernobyl fallout had a similar impact in Europe and parts of Asia. The birth sex odds near nuclear facilities are also distorted. The persistently disturbed secular human sex odds trends allow the estimation of the global deficit of births in the range of several millions.
Trends in Firearm Suicide among Older American Males: 1979-1988.
ERIC Educational Resources Information Center
Kaplan, Mark S.; And Others
1994-01-01
Used National Center for Health Statistics Compressed Mortality data to perform age-specific analysis of linear trends in suicide. Found males aged 65+ years were most likely to use firearms. In 1988, nearly 80% of suicides by older males were committed with firearms. Firearm-related suicide rates were much lower for blacks than whites 65 and…
Air Pollution and urban climatology at Norfolk, Virginia
W. Maurice Pritchard; Kuldip P. Chopra
1977-01-01
The atmosphere at Norfolk is usually stable, with no strongly prevailing wind direction. Linear regression analyses of visibility data indicate a generally decreasing visibility trend between 1960 and 1972, with a possible trend reversal in later years. A 44 percent increase in the annual frequency of 0-4-mile visibility occurred in 1960-72. Similar analyses of...
Obesity, High-Calorie Food Intake, and Academic Achievement Trends among U.S. School Children
ERIC Educational Resources Information Center
Li, Jian; O'Connell, Ann A.
2012-01-01
The authors investigated children's self-reported high-calorie food intake in Grade 5 and its relationship to trends in obesity status and academic achievement over the first 6 years of school. They used 3-level hierarchical linear models in the large-scale database (the Early Childhood Longitudinal Study--Kindergarten Cohort). Findings indicated…
21st Century Trends in the Potential for Ozone Depletion
NASA Astrophysics Data System (ADS)
Hurwitz, M. M.; Newman, P. A.
2009-05-01
We find robust trends in the area where Antarctic stratospheric temperatures are below the threshold for polar stratospheric cloud (PSC) formation in Goddard Earth Observing System (GEOS) chemistry-climate model (CCM) simulations of the 21st century. In late winter (September-October-November), cold area trends are consistent with the respective trends in equivalent effective stratospheric chlorine (EESC), i.e. negative cold area trends in 'realistic future' simulations where EESC decreases and the ozone layer recovers. In the early winter (April through June), regardless of EESC scenario, we find an increasing cold area trend in all simulations; multiple linear regression analysis shows that this early winter cooling trend is associated with the predicted increase in greenhouse gas concentrations in the future. We compare the seasonality of the potential for Antarctic ozone depletion in two versions of the GEOS CCM and assess the impact of the above-mentioned cold area trends on polar stratospheric chemistry.
Language and hope in schizophrenia-spectrum disorders.
Bonfils, Kelsey A; Luther, Lauren; Firmin, Ruth L; Lysaker, Paul H; Minor, Kyle S; Salyers, Michelle P
2016-11-30
Hope is integral to recovery for those with schizophrenia. Considering recent advancements in the examination of clients' lexical qualities, we were interested in how clients' words reflect hope. Using computerized lexical analysis, we examined social, emotion, and future words' relations to hope and its pathways and agency components. Forty-five clients provided detailed narratives about their life and mental illness. Transcripts were analyzed using the Linguistic Inquiry and Word Count program (LIWC), which assigns words to categories (e.g., "anxiety") based on a pre-existing dictionary. Correlations and linear multiple regression were used to examine relationships between lexical qualities and hope. Hope and its subcomponents had significant or trending bivariate correlations in expected directions with several emotion-related word categories (anger and sadness) but were not associated with expected categories such as social words, positive emotions, optimism, achievement, and future words. In linear multiple regressions, no LIWC variable significantly predicted hope agency, but anger words significantly predicted both total hope and hope pathways. Our findings indicate lexical analysis tools can be used to investigate recovery-oriented concepts such as hope, and results may inform clinical practice. Future research should aim to replicate our findings in larger samples. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
Long-Term Vegetation Trends Detected In Northern Canada Using Landsat Image Stacks
NASA Astrophysics Data System (ADS)
Fraser, R.; Olthof, I.; Carrière, M.; Deschamps, A.; Pouliot, D.
2011-12-01
Evidence of recent productivity increases in arctic vegetation comes from a variety of sources. At local scales, long-term plot measurements in North America are beginning to record increases in vascular plant cover and biomass. At landscape scales, expansion and densification of shrubs has been observed using repeat oblique photographs. Finally, continental-scale increases in vegetation "greenness" have been documented based on analysis of coarse resolution (≥ 1 km) NOAA-AVHRR satellite imagery. In this study we investigated intermediate, regional-level changes occurring in tundra vegetation since 1984 using the Landsat TM and ETM+ satellite image archive. Four study areas averaging 13,619 km2 were located over widely distributed national parks in northern Canada (Ivvavik, Sirmilik, Torngat Mountains, and Wapusk). Time-series image stacks of 16-41 growing-season Landsat scenes from overlapping WRS-2 frames were acquired spanning periods of 17-25 years. Each pixel's unique temporal database of clear-sky values was then analyzed for trends in four indices (NDVI, Tasseled Cap Brightness, Greenness and Wetness) using robust linear regression. The trends were further related to changes in the fractional cover of functional vegetation types using regression tree models trained with plot data and high resolution (≤ 10 m) satellite imagery. We found all four study areas to have a larger proportion of significant (p<0.05) positive greenness trends (range 6.1-25.5%) by comparison to negative trends (range 0.3-4.1%). For the three study areas where regression tree models could be derived, consistent trends of increasing shrub or vascular fractional cover and decreasing bare cover were predicted. The Landsat-based observations were associated with warming trends in each park over the analysis periods. Many of the major changes observed could be corroborated using published studies or field observations.
Status of the interior population of least tern
Kirsch, E.M.; Sidle, John G.
1999-01-01
Because the interior population of least tem (Sterna antillarum) was listed as endangered in 1985, information on population status, trends, and productivity is needed to guide management of this population. We compared recent estimates (1986-95) of tern numbers to objectives identified in the Recovery Plan, used linear regression to estimate trends for local areas (e.g., river segment, reservoir), anti route regression to estimate trends for larger segments of the breeding range. We also compared observed estimates of fledging success to the minimum valve (0.51 fledglings/pair) thought necessary for population maintenance to determine whether observed productivity could support recent population trends. Although the interior population exceeded the recovery goal of 7,000 birds in 1995, this was due to large increases in tern numbers along a 901-km stretch of the Lower Mississippi River, and numbers for most breeding areas have not reached recovery levels. Trend (lambda) was significant for 7 (5 positive, 2 negative) of 31 local areas for which trend could be calculated. At larger scales, lambda was not discernibly different from 1 for the Platte and Missouri river drainages, but lambda was >1 for the Lower Mississippi River drainage. Overall trend for the interior population was 1.090 (95% CI = 1.056-1.111), and 1.024 (95% CI = 0.998-1.045) when data from the Lower Mississippi River were excluded. Fledging; success ranged from 0.00 to 2.33 fledglings/pair, and was <0.51 in 9 areas. Based on available fledging success estimates, there is no evidence that productivity within the interior range caused recent increases in tern numbers. Improved rangewide monitoring of numbers and productivity, and information on movements and postfledging survival, are needed to assess recovery criteria and management options for this population of least terns.
Non-Linear Concentration-Response Relationships between Ambient Ozone and Daily Mortality.
Bae, Sanghyuk; Lim, Youn-Hee; Kashima, Saori; Yorifuji, Takashi; Honda, Yasushi; Kim, Ho; Hong, Yun-Chul
2015-01-01
Ambient ozone (O3) concentration has been reported to be significantly associated with mortality. However, linearity of the relationships and the presence of a threshold has been controversial. The aim of the present study was to examine the concentration-response relationship and threshold of the association between ambient O3 concentration and non-accidental mortality in 13 Japanese and Korean cities from 2000 to 2009. We selected Japanese and Korean cities which have population of over 1 million. We constructed Poisson regression models adjusting daily mean temperature, daily mean PM10, humidity, time trend, season, year, day of the week, holidays and yearly population. The association between O3 concentration and mortality was examined using linear, spline and linear-threshold models. The thresholds were estimated for each city, by constructing linear-threshold models. We also examined the city-combined association using a generalized additive mixed model. The mean O3 concentration did not differ greatly between Korea and Japan, which were 26.2 ppb and 24.2 ppb, respectively. Seven out of 13 cities showed better fits for the spline model compared with the linear model, supporting a non-linear relationships between O3 concentration and mortality. All of the 7 cities showed J or U shaped associations suggesting the existence of thresholds. The range of city-specific thresholds was from 11 to 34 ppb. The city-combined analysis also showed a non-linear association with a threshold around 30-40 ppb. We have observed non-linear concentration-response relationship with thresholds between daily mean ambient O3 concentration and daily number of non-accidental death in Japanese and Korean cities.
Moyer, Douglas; Hirsch, Robert M.; Hyer, Kenneth
2012-01-01
Nutrient and sediment fluxes and changes in fluxes over time are key indicators that water resource managers can use to assess the progress being made in improving the structure and function of the Chesapeake Bay ecosystem. The U.S. Geological Survey collects annual nutrient (nitrogen and phosphorus) and sediment flux data and computes trends that describe the extent to which water-quality conditions are changing within the major Chesapeake Bay tributaries. Two regression-based approaches were compared for estimating annual nutrient and sediment fluxes and for characterizing how these annual fluxes are changing over time. The two regression models compared are the traditionally used ESTIMATOR and the newly developed Weighted Regression on Time, Discharge, and Season (WRTDS). The model comparison focused on answering three questions: (1) What are the differences between the functional form and construction of each model? (2) Which model produces estimates of flux with the greatest accuracy and least amount of bias? (3) How different would the historical estimates of annual flux be if WRTDS had been used instead of ESTIMATOR? One additional point of comparison between the two models is how each model determines trends in annual flux once the year-to-year variations in discharge have been determined. All comparisons were made using total nitrogen, nitrate, total phosphorus, orthophosphorus, and suspended-sediment concentration data collected at the nine U.S. Geological Survey River Input Monitoring stations located on the Susquehanna, Potomac, James, Rappahannock, Appomattox, Pamunkey, Mattaponi, Patuxent, and Choptank Rivers in the Chesapeake Bay watershed. Two model characteristics that uniquely distinguish ESTIMATOR and WRTDS are the fundamental model form and the determination of model coefficients. ESTIMATOR and WRTDS both predict water-quality constituent concentration by developing a linear relation between the natural logarithm of observed constituent concentration and three explanatory variables—the natural log of discharge, time, and season. ESTIMATOR uses two additional explanatory variables—the square of the log of discharge and time-squared. Both models determine coefficients for variables for a series of estimation windows. ESTIMATOR establishes variable coefficients for a series of 9-year moving windows; all observed constituent concentration data within the 9-year window are used to establish each coefficient. Conversely, WRTDS establishes variable coefficients for each combination of discharge and time using only observed concentration data that are similar in time, season, and discharge to the day being estimated. As a result of these distinguishing characteristics, ESTIMATOR reproduces concentration-discharge relations that are closely approximated by a quadratic or linear function with respect to both the log of discharge and time. Conversely, the linear model form of WRTDS coupled with extensive model windowing for each combination of discharge and time allows WRTDS to reproduce observed concentration-discharge relations that are more sinuous in form. Another distinction between ESTIMATOR and WRTDS is the reporting of uncertainty associated with the model estimates of flux and trend. ESTIMATOR quantifies the standard error of prediction associated with the determination of flux and trends. The standard error of prediction enables the determination of the 95-percent confidence intervals for flux and trend as well as the ability to test whether the reported trend is significantly different from zero (where zero equals no trend). Conversely, WRTDS is unable to propagate error through the many (over 5,000) models for unique combinations of flow and time to determine a total standard error. As a result, WRTDS flux estimates are not reported with confidence intervals and a level of significance is not determined for flow-normalized fluxes. The differences between ESTIMATOR and WRTDS, with regard to model form and determination of model coefficients, have an influence on the determination of nutrient and sediment fluxes and associated changes in flux over time as a result of management activities. The comparison between the model estimates of flux and trend was made for combinations of five water-quality constituents at nine River Input Monitoring stations. The major findings with regard to nutrient and sediment fluxes are as follows: (1)WRTDS produced estimates of flux for all combinations that were more accurate, based on reduction in root mean squared error, than flux estimates from ESTIMATOR; (2) for 67 percent of the combinations, WRTDS and ESTIMATOR both produced estimates of flux that were minimally biased compared to observed fluxes(flux bias = tendency to over or underpredict flux observations); however, for 33 percent of the combinations, WRTDS produced estimates of flux that were considerably less biased (by at least 10 percent) than flux estimates from ESTIMATOR; (3) the average percent difference in annual fluxes generated by ESTIMATOR and WRTDS was less than 10 percent at 80 percent of the combinations; and (4) the greatest differences related to flux bias and annual fluxes all occurred for combinations where the pattern in observed concentration-discharge relation was sinuous (two points of inflection) rather than linear or quadratic (zero or one point of inflection). The major findings with regard to trends are as follows: (1) both models produce water-quality trends that have factored in the year-to-year variations in flow; (2) trends in water-quality condition are represented by ESTIMATOR as a trend in flow-adjusted concentration and by WRTDS as a flow normalized flux; (3) for 67 percent of the combinations with trend estimates, the WRTDS trends in flow-normalized flux are in the same direction and magnitude to the ESTIMATOR trends in flow-adjusted concentration, and at the remaining 33 percent the differences in trend magnitude and direction are related to fundamental differences between concentration and flux; and (4) the majority (85 percent) of the total nitrogen, nitrate, and orthophosphorus combinations exhibited long-term (1985 to 2010) trends in WRTDS flow-normalized flux that indicate improvement or reduction in associated flux and the majority (83 percent) of the total phosphorus (from 1985 to 2010) and suspended sediment (from 2001 to 2010) combinations exhibited trends in WRTDS flow-normalized flux that indicate degradation or increases in the flux delivered.
Ushida, Keisuke; McGrath, Colman P; Lo, Edward C M; Zwahlen, Roger A
2015-07-24
Even though oral cavity cancer (OCC; ICD 10 codes C01, C02, C03, C04, C05, and C06) ranks eleventh among the world's most common cancers, accounting for approximately 2 % of all cancers, a trend analysis of OCC in Hong Kong is lacking. Hong Kong has experienced rapid economic growth with socio-cultural and environmental change after the Second World War. This together with the collected data in the cancer registry provides interesting ground for an epidemiological study on the influence of socio-cultural and environmental factors on OCC etiology. A multidirectional statistical analysis of the OCC trends over the past 25 years was performed using the databases of the Hong Kong Cancer Registry. The age, period, and cohort (APC) modeling was applied to determine age, period, and cohort effects on OCC development. Joinpoint regression analysis was used to find secular trend changes of both age-standardized and age-specific incidence rates. The APC model detected that OCC development in men was mainly dominated by the age effect, whereas in women an increasing linear period effect together with an age effect became evident. The joinpoint regression analysis showed a general downward trend of age-standardized incidence rates of OCC for men during the entire investigated period, whereas women demonstrated a significant upward trend from 2001 onwards. The results suggest that OCC incidence in Hong Kong appears to be associated with cumulative risk behaviors of the population, despite considerable socio-cultural and environmental changes after the Second World War.
NASA Astrophysics Data System (ADS)
Oruganti, Pradeep Sharma; Krak, Michael D.; Singh, Rajendra
2018-01-01
Recently Krak and Singh (2017) proposed a scientific experiment that examined vibro-impacts in a torsional system under a step down excitation and provided preliminary measurements and limited non-linear model studies. A major goal of this article is to extend the prior work with a focus on the examination of vibro-impact phenomena observed under step responses in a torsional system with one, two or three controlled clearances. First, new measurements are made at several locations with a higher sampling frequency. Measured angular accelerations are examined in both time and time-frequency domains. Minimal order non-linear models of the experiment are successfully constructed, using piecewise linear stiffness and Coulomb friction elements; eight cases of the generic system are examined though only three are experimentally studied. Measured and predicted responses for single and dual clearance configurations exhibit double sided impacts and time varying periods suggest softening trends under the step down torque. Non-linear models are experimentally validated by comparing results with new measurements and with those previously reported. Several metrics are utilized to quantify and compare the measured and predicted responses (including peak to peak accelerations). Eigensolutions and step responses of the corresponding linearized models are utilized to better understand the nature of the non-linear dynamic system. Finally, the effect of step amplitude on the non-linear responses is examined for several configurations, and hardening trends are observed in the torsional system with three clearances.
The utility of gravity and water-level monitoring at alluvial aquifer wells in southern Arizona
Pool, D.R.
2008-01-01
Coincident monitoring of gravity and water levels at 39 wells in southern Arizona indicate that water-level change might not be a reliable indicator of aquifer-storage change for alluvial aquifer systems. One reason is that water levels in wells that are screened across single or multiple aquifers might not represent the hydraulic head and storage change in a local unconfined aquifer. Gravity estimates of aquifer-storage change can be approximated as a one-dimensional feature except near some withdrawal wells and recharge sources. The aquifer storage coefficient is estimated by the linear regression slope of storage change (estimated using gravity methods) and water-level change. Nonaquifer storage change that does not percolate to the aquifer can be significant, greater than 3 ??Gal, when water is held in the root zone during brief periods following extreme rates of precipitation. Monitor-ing of storage change using gravity methods at wells also can improve understanding of local hydrogeologic conditions. In the study area, confined aquifer conditions are likely at three wells where large water-level variations were accompanied by little gravity change. Unconfined conditions were indicated at 15 wells where significant water-level and gravity change were positively linearly correlated. Good positive linear correlations resulted in extremely large specific-yield values, greater than 0.35, at seven wells where it is likely that significant ephemeral streamflow infiltration resulted in unsaturated storage change. Poor or negative linear correlations indicate the occurrence of confined, multiple, or perched aquifers. Monitoring of a multiple compressible aquifer system at one well resulted in negative correlation of rising water levels and subsidence-corrected gravity change, which suggests that water-level trends at the well are not a good indicatior of overall storage change. ?? 2008 Society of Exploration Geophysicists. All rights reserved.
Ambient temperature and FIT performance in the Emilia-Romagna colorectal cancer screening programme.
De Girolamo, Gianfranco; Goldoni, Carlo A; Corradini, Rossella; Giuliani, Orietta; Falcini, Fabio; Sassoli De'Bianchi, Priscilla; Naldoni, Carlo; Zauli Sajani, Stefano
2016-12-01
To assess the impact of ambient temperature on faecal immunochemical test (FIT) performance in the colorectal cancer screening programme of Emilia-Romagna (Italy). A population-based retrospective cohort study on data from 2005 to 2011. Positive rate, detection rate, and positive predictive value rate for cancers and adenomas, and incidence rate of interval cancers after negative tests were analysed using Poisson regression models. In addition to ambient temperature, gender, age, screening history, and Local Health Unit were also considered. In 1,521,819 tests analysed, the probability of a positive result decreased linearly with increasing temperature. Point estimates and 95% Confidence Intervals were estimated for six temperature classes (<5, 5 |-10, 10 |-15, 15 |-20, 20|-25 and ≥25℃), and referred to the 5|-10℃ class. The positive rate ratio was significantly related to temperature increase: 0.99 (0.97-1.02), 1, 0.98 (0.96-1.00), 0.96 (0.94-0.99), 0.93 (0.91-0.96), 0.92 (0.89-0.95). A linear trend was also evident for advanced adenoma detection rate ratio: 1.00 (0.96-1.04), 1, 0.98 (0.93-1.02), 0.96 (0.92-1.00), 0.92 (0.88-0.96), 0.94 (0.88-1.01). The effect was less linear, but still important, for cancer detection rates: 0.95 (0.85-1.06), 1, 1.00 (0.90-1.10), 0.94 (0.85-1.05), 0.81 (0.72-0.92), 0.93 (0.80-1.09). No association or linear trend was found for positive predictive values or risk of interval cancer, despite an excess of +16% in the highest temperature class for interval cancer. Ambient temperatures can affect screening performance. Continued monitoring is needed to verify the effect of introducing FIT tubes with a new buffer, which should guarantee a higher stability of haemoglobin. © The Author(s) 2016.
Complex messages regarding a thin ideal appearing in teenage girls' magazines from 1956 to 2005.
Luff, Gina M; Gray, James J
2009-03-01
Seventeen and YM were assessed from 1956 through 2005 (n=312) to examine changes in the messages about thinness sent to teenage women. Trends were analyzed through an investigation of written, internal content focused on dieting, exercise, or both, while cover models were examined to explore fluctuations in body size. Pearson's Product correlations and weighted-least squares linear regression models were used to demonstrate changes over time. The frequency of written content related to exercise and combined plans increased in Seventeen, while a curvilinear relationship between time and content relating to dieting appeared. YM showed a linear increase in content related to dieting, exercise, and combined plans. Average cover model body size increased over time in YM while demonstrating no significant changes in Seventeen. Overall, more written messages about dieting and exercise appeared in teen's magazines in 2005 than before while the average cover model body size increased.
Fluorescence-based monitoring of tracer and substrate distribution in an UASB reactor.
Lou, S J; Tartakovsky, B; Zeng, Y; Wu, P; Guiot, S R
2006-11-01
In this work, rhodamine-related fluorescence was measured on-line at four reactor heights in order to study hydrodynamics within an upflow anaerobic sludge bed reactor. A linear dependence of the dispersion coefficient (D) on the upflow velocity was observed, while the influence of the organic loading rate (OLR) was insignificant. Furthermore, the Bodenstein number of the reactor loaded with granulated sludge was found to be position-dependent with the largest values measured at the bottom of the sludge bed. This trend was not observed in the reactor without sludge. Chemical oxygen demand (COD) and volatile fatty acid (VFA) concentrations were measured at the same reactor heights as in rhodamine tests using conventional off-line analytical methods and on-line multiwavelength fluorometry. Significant spatial COD and VFA gradients were observed at organic loading rates above 6g COD l(R)(-1)d(-1) and linear upflow velocities below 0.8m h(-1).
NASA Technical Reports Server (NTRS)
Guillemot, J. (Principal Investigator)
1974-01-01
The author has identified the following significant results. ERTS-1 images obviously show up some large linear features trending N 80 E or N 30 E common to both Alps and Pyrenees. One of them, the Ligurian Fault, had been previously forecast by Laubscher in an interpretation of the Alps by the plate tectonic theory, but it extends westward farthest from the Alps, cutting the Pyrenees axis. These lineaments have been interpreted as reflections of deep seated wrench faults in the surficial part of the sedimentary series. A large set of such lineaments is perceptible in western Europe, such as the Guadalquivir Fault in southern Spain, Ligurian Fault, Insubrian Fault, Northern-Jura Fault, Metz Fault. Perhaps these may be interpreted as transform faults of the mid-Atlantic ridge or of a paleo-rift seated in the Rhine-Rhone graben.
Kashdan, Todd B; Roberts, John E; Carlos, Erica L
2006-04-01
The present study examined trajectories of change in the frequency of overgeneral autobiographical memory (OGM) over the course of repeated trials, and tested whether particular dimensions of depressive symptomatology (somatic and cognitive-affective distress), self-esteem, and neuroticism account for individual differences in these trajectories. Given that depression is associated with impairments in effortful processing, we predicted that over repeated trials depression would be associated with increasingly OGM. Generalised Linear Mixed Models with Penalised Quasi-Likelihood demonstrated significant linear and quadratic trends in OGM over repeated trials, and somatic distress and self-esteem moderated these slopes. The form of these interactions suggested that somatic distress and low self-esteem primarily contribute to OGM during the second half of the trial sequence. The present findings demonstrate the value of a novel analytical approach to OGM that estimates individual trajectories of change over repeated trials.