Decile Values Research Articles

Paradoxical association between lipid levels and incident atrial fibrillation according to statin usage

Abstract Background In epidemiology studies, a higher level of total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) is associated with a lower risk of atrial fibrillation (AF). Statin use might exert possible confounding effects in the paradoxical relationship; however, the inverse link between AF and cholesterol level that distinguishes statin users from non-users has not been evaluated. Objective We investigated the epidemiological relationships of TC–AF and LDL-C–AF in statin users and non-users, respectively. Methods From the Korean National Health Insurance Service database, we included 9,778,014 adults who underwent a health examination in 2009 and had no prior AF history. The levels of TC and LCL-C at the health exam were categorized in quartile (Q) and decile (D) values of the total study population. The study population was grouped into statin users and non-users, and TC–AF and LDL-C–AF relationships were evaluated. Results 867,336 (8.9%) were on statin use among the total population. Statin users showed higher TC level (208.4±55.6 vs. 194.1±39.5 mg/dL, p<0.001) and LDL-C level (123.0±102.2 vs. 121.3±226.3, p<0.001) compared to non-users. Inverse associations of TC–AF and LCL-C–AF were observed; higher levels of TC and LDL-C were associated with a lower risk of AF. The hazard ratios (HR) and 95% confidence intervals (CI) were 0.797 (0.786–0.809) for the highest quartile of TC (Q4, TC ≥218) and 0.832 (0.82–0.843) for the highest quartile of LDL-C (Q4, LDL-C ≥135) when adjusted by age, sex, lifestyle behaviors, comorbidities, and low-income status. Statin users exhibited higher AF incidence rate than non-statin users, but the association in statin users generally tracked that seen among non-statin users demonstrating similar HR in Q4 of TC [0.812 (0.790–0.835) for statin users and 0.812 (0.798–0.826) for non-statin users] and LDL-C [0.842 (0.819–0.865) for statin users and 0.849 (0.835–0.863) for non-statin users]. Conclusion The paradoxical relationship between lipid levels (TC and LDL-C) and incident AF remained consistent both in statin users and non-users. Further research is required to investigate an underlying mechanism for the cholesterol paradox of AF which still seems evident despite the pleiotropic effects of statin. Funding Acknowledgement Type of funding sources: None.

Wilderness areas in a changing landscape: changes in land use, land cover, and climate.

Wilderness areas are not immune to changes in land use, land cover, and/or climate. Future changes will intensify the balancing act of maintaining ecological conditions and untrammeled character within wilderness areas. We assessed the quantitative and spatial changes in land use, land cover, and climate predicted to occur in and around wilderness areas by (1) quantifying projected changes in land use and land cover around wilderness areas; (2) evaluating if public lands surrounding wilderness areas can buffer future land‐use change; (3) quantifying future climate conditions in and around wilderness areas; and (4) identifying wilderness areas expected to experience the most change in land use, land cover, and climate. We used projections of land use (four variables), land cover (five variables), and climate (nine variables) to assess changes for 707 wilderness areas in the contiguous United States by mid‐21st century under two scenarios (medium‐low and high). We ranked all wilderness areas relative to each other by summing and ranking decile values for each land use, land cover, and climate variable and calculating a multivariate metric of future change. All wilderness areas were projected to experience some level of change by mid‐century. The greatest land‐use changes were associated with increases in agriculture, clear cutting, and developed land, while the greatest land cover changes were observed for grassland, forest, and shrubland. In 51.6% and 73.8% of wilderness areas, core area of natural vegetation surrounding wilderness was projected to decrease for the medium‐low and high scenarios, respectfully. Presence of public land did not mitigate the influence of land‐use change around wilderness areas. Geographically, projected changes occurred throughout the contiguous U.S., with areas in the northeast and upper Midwest projected to have the greatest land‐use and climate change and the southwestern U.S. projected to undergo the greatest land cover and climate change. Our results provide insights into potential future threats to wilderness areas and the challenges associated with wilderness stewardship and climate adaptation. Despite the high degree of protection and remoteness of wilderness areas, effective management and preservation of these lands must consider future changes in land use, land cover, and climate.

Population normative data for three cognitive screening tools for older adults in sub-Saharan Africa.

ABSTRACTIn sub-Saharan Africa (SSA),cognitive screening is complicated by both cultural and educational factors, and the existing normative values may not be applicable. The Identification of Dementia in Elderly Africans (IDEA) cognitive screen is a low-literacy measure with good diagnostic accuracy for dementia.Objective: The aim of this study is to report normative values for IDEA and other simple measures [i.e., categorical verbal fluency, the Consortium to Establish a Registry for Alzheimer’s Disease (CERAD) 10-word list] in representative community-dwelling older adults in SSA.Methods: Individuals aged ≥60 years resident in 12 representative villages in Kilimanjaro, Tanzania and individuals aged ≥65 years resident within three communities in Akinyele Local Government Area, Oyo State, Nigeria underwent cognitive screening. The normative data were generated by the categories of age, sex, and education.Results: A total of 3,011 people in Tanzania (i.e., 57.3% females and 26.4% uneducated) and 1,117 in Nigeria (i.e., 60.3% females and 64.5% uneducated) were screened. Individuals with higher age, lower education, and female gender obtained lower scores. The 50th decile values for IDEA were 13 (60–64 years) vs. 8/9 (above 85 years), 10–11 uneducated vs. 13 primary educated, and 11/12 in females vs. 13 in males. The normative values for 10-word list delayed recall and categorical verbal fluency varied with education [i.e., delayed recall mean 2.8 [standard deviation (SD) 1.7] uneducated vs. 4.2 (SD 1.2) secondary educated; verbal fluency mean 9.2 (SD 4.8) uneducated vs. 12.2 (SD 4.3) secondary educated], substantially lower than published high-income country values.Conclusions: The cut-off values for commonly used cognitive screening items should be adjusted to suit local normative values, particularly where there are lower levels of education.

Incident Co-Morbidities in Patients with Atrial Fibrillation Initially with a CHA2DS2-VASc Score of 0 (Males) or 1 (Females): Implications for Reassessment of Stroke Risk in Initially 'Low-Risk' Patients.

Oral anticoagulants (OACs) are not recommended for 'low-risk' patients with atrial fibrillation (AF). We investigated the incidences of new risk factors developing, and the temporal trends in the CHA2DS2-VASc score in initially 'low-risk' AF patients. Second, we propose a reasonable timing interval at which stroke risk should be reassessed for such AF patients. We studied 14,606 AF patients who did not receive anti-platelet agents or OACs with a baseline CHA2DS2-VASc score of 0 (males) or 1 (females). The CHA2DS2-VASc scores of patients were followed up and updated until the occurrence of ischaemic stroke or mortality or 31 December 2011. The associations between the prescription of warfarin and risk of adverse events once patients' scores changed were analysed. Decile values of durations to incident co-morbidities and from the acquirement of new co-morbidities to ischaemic stroke were studied. During a mean follow-up of 4 years, 7,079 (48.5%) patients acquired at least one new stroke risk factor component(s) with annual risks of 6.35% for hypertension, 3.68% for age ≥ 65 years, 2.77% for heart failure, 1.99% for diabetes mellitus and 0.33% for vascular diseases. The incidence for CHA2DS2-VASc score increments was 12.1%/year. Initiation of warfarin was associated with a lower risk of adverse events (adjusted hazard ratio, 0.530; 95% confidence interval, 0.371-0.755). Among 6,188 patients who acquired new risk factors, 80% would acquire these co-morbidities after 4.2 months of AF diagnosis. The duration from the acquirement of incident co-morbidities to the occurrence of ischaemic stroke was longer than 4.4 months for 90% of the patients. The CHA2DS2-VASc score increases in approximately 12% of initially 'low-risk' AF patients each year, and the initiation of warfarin once the score changed was associated with a better prognosis. Three to four months may be a reasonable timing interval at which stroke risk should be reassessed so that OACs could be prescribed in a timely manner for stroke prevention.

MUF variability in the Arctic region: A statistical comparison with the ITU‐R variability factors

AbstractThe maximum usable frequency (MUF(3000)F2) decile factors obtained from observations at five stations located in the Arctic region: Resolute (74.75°N, 265.10°E), Dikson (73.50°N, 80.40°E), Norilsk (69.40°N, 88.10°E), Loparskaya (68.00°N, 33.00°E), and Sodankyla (67.40°N, 26.60°E) have been compared with the International Telecommunication Union (ITU‐R) estimates over three solar cycles (1961–2013). The summer MUF(3000)F2 variability has been found to lie in the range of ±0.2, whereas limits for equinox and winter seasons are ±0.3 and ±0.5, respectively. This observation seems to directly translate into high differences between the measurement‐derived and ITU‐R decile values in winter and the smaller values for summer. These results illustrate that the high latitude ionosphere, and thus the MUF, is highly variable in winter, followed by the equinox, and experiences a low variability in summer.

Application of sequential trend analysis for discharge characterisation of Vipava karstic springs, Slovenia

The discharge of Vipava springs and precipitation data of their recharge area have been statistically analyzed and presented in this paper to provide some additional insight into the hydrological regime of the aquifer. Monotone and sequential trends have been evaluated and interpreted based on a 45-year data measurement period between 1960 and 2004. The springs have a typical karstic regime with short-term periods of high discharge and long-term periods of mean and low discharge values. The ratio of low, mean and high discharges is about 1:10:100. The majority of the springs’ groundwater comes from precipitation in the recharge area. Supplementation of two different statistical analyses for sequential trend detection was applied to annual decile discharge values (1960–2004) due to the subjectivity of results interpretation. The first method involved the use of rescaled adjusted partial sums (RAPS) and the second non-parametric sequential Mann-Kendall trend detection. The purpose of the investigation was to determine if and to what extent the length and trend line direction of sub-periods differ between different annual decile values of Vipava springs and to what extent decile values are related to annual precipitation. Sequential trend analysis confirmed similarity in hydrological conditions between some neighbouring discharge decile values but not in others. This analysis also showed that the length of sub-periods and their linear trend direction differed with respect to low, mean and high annual decile discharge values.

Analysis of weekly rainfall of different period during rainy season over Safdarjung airport of Delhi for 20th century – A study on trend, decile and decadal analysis

The analysis of weekly rainfall and of different period during rainy season of Safdarjang airport using techniques like trend and decile have been attempted. Decadal analysis is also attempted to see any changes during the entire period. Rainy season is defined as rainfall received from week no. 23rd to 38th. Weekly rainfall data for period 1901 to 2000 is utilized for this location. As week is a shorter period to analyze rainfall for the season groups of different periods consisting of 4 weeks such as 1-4 as ‘A’, 5-8 as ‘B’ and so on up to ‘D’ is formed. For study of progressive season combination of groups such as ‘A+B’, A+B+C and ‘A+B+C+D’ are also subjected to analysis as done for weekly as well for group.
 The average weekly rainfall distribution indicates very high positive value of coefficient of correlation (0.94) significant at 1% level. The coefficient variation (C.V.) of weekly average rainfall shows consistency from decade 5th to 8th and 10th. Profile of average C.V. of weekly rainfall for 100 years shows consistency from week 4 to 11. Week no. 8 shows peak of rainfall. Overall decile analysis of weekly rainfall shows increasing tendency from week no. 1 to 8 for all deciles and then decreasing tendency from week no. 9 on words for all decile values. Trend analysis of group ‘C’ shows significant positive tendency with correlation as +0.20 significant at 5% level. However trend analysis of deciles of all groups shows very high C.C. around +0.95 at 1% level. Trend analysis of combination of groups shows positive trend for A+B+C and for A+B+C+D with a C.C. of 0.25 and 0.20 at 5% level. Trend of deciles for these groups also shows very high C.C. values around +0.95 at 1% level. Average, excess and deficient rainfall seen at Safdarjung airport is 5th, 7th and 4th decile with values as 594, 708 and 472 mm respectively. Analysis of two halves of century, viz., 1901-50 and 1951-2000 shows no significant trend.

Relationships between particle‐size distribution and organic carbon in French arable topsoils

AbstractA database including results from 102 000 soil analyses was built for arable topsoil in France. We show a strong effect of soil particle‐size distribution on present organic carbon (OC) stocks in these soils. By using the upper decile values by textural classes as a proxy of the maximal carbon storage potential, we show that it might be more efficient to encourage practices favouring carbon accumulation in soils already having high OC stocks than to try to increase OC stocks in soils where present stocks are low.

On the global behaviour of the day-to-day MUF variation

Using data from more than a hundred ionospheric stations spread worldwide, day-to-day variations with location and time of the conventional maximum usable frequency (MUF) decile values are investigated. New bounds of day-to-day MUF variability are calculated and compared with reference figures currently used by radio users. An hourly-daily validation process shows a clear improvement of spatial bias and model accuracy. A significant dependence on longitude is revealed that might be introduced into future specifications.

Statistical addition method for external noise sources affecting HF‐MF‐LF systems

The current statistical method for the addition of external component noise sources in the LF, MF, and lower HF band (100 kHz to 3 MHz) produces total median noise levels that may be less than the largest‐component median in some cases. Several case studies illustrate this anomaly. Methods used to sum the components rely on their power (decibels) distributions being represented as normal by the statistical parameters. The atmospheric noise component is not correctly represented by its decile values when it is assumed to have a normal distribution, causing anomalies in the noise summation when components are similar in magnitude. A revised component summation method is proposed, and the way it provides a more physically realistic total noise median for LF, MF, and lower HF frequencies is illustrated.

Risk of fatal stroke according to blood pressure level: an 18-year follow-up of the Oslo Study

To determine how blood pressure level predicts the incidence of fatal stroke. The Oslo Study is a prospective cohort study of preventive and epidemiological aspects of cardiovascular disorders in middle-aged men. Of 25,915 men invited, 16,209 aged 40-49 years attended the screening. A 7% random sample of men aged 20-39 years were also invited to attend. The screening started in May 1972 and the analysis presented is an 18-year follow-up for fatal strokes. Men with a history of stroke were excluded from the analyses. Of 16,173 men with no history of stroke 85 died from stroke. Results from Cox proportional hazards regression analysis confirm diastolic (DBP) and systolic blood pressure (SBP) as strong independent risk factors of fatal stroke, with DBP being the stronger predictor. Analyses of risk of fatal stroke by quintile values show SBP to give significantly increased risk from the third quintile (136 mmHg), and DBP from the fifth quintile (95 mmHg) relative to the first quintile. No levelling off at highest levels can be seen when analysing decile values. No J-shape of the curve was evident. Men on drug treatment for hypertension with no stroke history (n = 440) had 4.7-fold (crude) and 2.8-fold (adjusted for age and DBP) the rate of stroke mortality of men not on drug treatment for hypertension. DBP was a stronger predictor than SBP, with increasing risk from the fifth quintile of DBP and the third quintile of SBP. Men on drug treatment for hypertension at screening were at increased risk during the follow-up period, indicating that their treatment did not sufficiently reduce their risk of stroke.

Atherogenic markers in the offspring vis-à-vis family history of coronary heart disease

The object of the study was to determine if atherogenic markers in the offspring reflected family history of coronary heart disease (CHD). Two hundred and four male subjects aged 9–18 years, mean age 13.3 ± 1.7 (S.D.) years, and apparently healthy and normolipidemic, were selected for the study. Information on their family history of fatal or non-fatal heart attack or stroke was obtained on a questionnaire, and a scoring system was devised to grade the positivity of family history. The boys having the highest decile values of triglyceride, ratios of LDL/HDL-cholesterol, total/HDL-cholesterol and apolipoprotien B/A-I, and cumulative skin-fold thickness, a marker of obesity, had higher family history scores and increased occurrence of myocardial infarction in their families than the boys with the lowest decile values of these variables. The reverse was true with variables such as HDL-cholesterol and apolipoprotein A-I, high levels of which are known to be cardioprotective by virtue of controlling reverse cholesterol transport. The mean values of triglyceride and total/HDL-cholesterol ratio were significantly elevated in the boys with positive parental history of CHD as compared with those with negative parental history. Thus, although the boys were normolipidemic, their lipoprotein markers and an obesity marker exhibited a variation which in turn reflected family history of CHD.

Some distinct effects of tropical monsoon clouds as derived from atmospherics

The electrical effects due to monsoon clouds in conjunction with the VLF atmospherics data have been extensively analyzed. The cloud distribution and rainfall pattern during the SW monsoon period are examined. The diurnal curves of rainfall show that the maximum rain generally occurs in the afternoon hours between 13 to 18 IST. The coefficient of variation (CV) of monsoon rainfall plotted against rainfall amount reveals that CV decreases with increasing rainfall amounts upto about 40 inches. The differences in the mean dry bulb temperature as well as mean relative humidity values at the standard levels between strong and weak monsoon are studied. The monthly median of the hourly average together with the respective upper and lower decile values of atmospherics have been considered. Also, the frequency dependence of afternoon maximum (or late afternoon minimum) to morning minimum in the sferics level is taken into account to determine the seasonal variation. During monsoon months the sferics level with higher cloud amount (⩾4 okta) increases considerably but the width of the sferics is reduced. The results are interpreted by considering the activity of the sources involved at such times.

On the quasi‐periodic nature of magnetopause flux transfer events

The recurrence rate of flux transfer events (FTEs) observed near the dayside magnetopause is discussed. A survey of magnetopause observations by the ISEE satellites shows that the distribution of the intervals between FTE signatures has a mode value of 3 min, but is highly skewed, having upper and lower decile values of 1.5 min and 18.5 min, respectively. The mean value is found to be 8 min, consistent with previous surveys of magnetopause data. The recurrence of quasi‐periodic events in the dayside auroral ionosphere is frequently used as evidence for an association with magnetopause FTEs, and the distribution of their repetition intervals should be matched to that presented here if such an association is to be confirmed. A survey of 1 year's 15‐s data on the interplanetary magnetic field (IMF) suggests that the derived distribution could arise from fluctuations in the IMF Bz component, rather than from a natural oscillation frequency of the magnetosphere‐ionosphere system.

Agricultural water balance of Yunnan Province, PR China: agroclimatic zoning with a Geographical Information System

Yunnan Province is located in the extreme southwest of the PR China, bordering Vietnam and Burma. Mostly mountainous in character it features a subtropical monsoon climate and moderate temperatures due to average elevations of 1000–3000 m. To help identify the potential for rainfed crop production the agricultural water balance for rice and maize was evaluated with the help of a Geographical Information System. Input values consisted of precipitation, temperature and evapotranspiration fields extrapolated from 42 meterological stations, soil data and phenological data. Instead of arithmetic means, eighth decile values were used for the climatological data to account for the interannual variation. Using the concept of cumulative water balance the model predicts that with the exception of a few hot-dry valleys the southwestern part of the province qualifies as fully suitable with a seasonal water supply of 80–100% while East Yunnan generally shows less favorable conditions with 50–80% of the seasonal water supply. The dividing line between these regions corresponds to a well-known climatic boundary between monsoon regimes. The water balance is only moderately correlated to altitude. Variation in water storage capacity of the soil is predicted to be secondary in importance to the effectiveness of rainfall. Rice in general is expected to show a better result than maize. Most of these differences can be explained by the assumed higher effectiveness of rainfall on terraced rice fields as compared to the cultivation of maize on unterraced slopes.

Normal values for range of shoulder abduction in men and women aged over 65 years.

The range of movement of the shoulder in abduction at 45 degrees of flexion was objectively measured using a standard technique in a demographically representative survey of 1000 men and women living in their own homes. Sampling was stratified to obtain approximately equal numbers of those aged 65-74 years and those aged 75 and over. The response rate was 80%. Normal values for shoulder abduction grouped by age and sex are presented as frequency distributions, means and deciles. Information about health problems was also recorded in the survey; the prevalences of these problems and their associations with shoulder abduction have been investigated. Women had significantly lower values for shoulder abduction than men. For both sexes values were on average about 30 degrees lower than those found in younger adults, and about half of the elderly group had values below 120 degrees. The prevalence of specified health problems was high with only 3% of the older group and 6% of the younger group being free from all the specified health problems. There was a significant independent negative association between shoulder abduction and both age and reported health. The associations were more marked in women than in men. This was so for both a cumulated 14-item health index and selected individual health items which included arthritis, lack of mobility and incontinence. The decile values for shoulder abduction for women without these health problems are presented. This provides more appropriate normal data for them; it is more normally distributed and reduces the percentage with a shoulder abduction less than 120 degrees to 30%.(ABSTRACT TRUNCATED AT 250 WORDS)

Individual Sky Wave Mode Loss Statistics Measured on a North–South Path

The HF propagation loss behavior, in general, and the observed losses over the north‐south path reported here, in particular, can be explained in terms of a deterministic and a random component. Thus, the results are presented as the cumulative distributions of loss by frequencies and by modes in terms of their median and decile values. The most significant aspect of these data and the accompanying statistics is that the propagation losses were observed and analyzed strictly on the individual mode basis. Among these propagation modes are included 2‐hop E, 1‐hop F2, 2‐hop F2, 2‐hop E8, and N. From the medians and the deciles of the loss distributions of these various modes, it is quite apparent that propagation losses are mode dependent, day and night dependent, and sometimes high‐ and low‐ray dependent. The E‐mode losses also appear to be dependent on the ratio of the operating frequency and the maximum observed frequency of the path.

Note on New Numerical Maps of ƒ0E8 for Solar Cycle Minimum and Maximum

Limitations of numerical maps of lower decile, median, and upper decile values of ƒ0E8 derived for each month of both a solar cycle minimum and a solar cycle maximum year, and some applications to propagation problems are discussed briefly. The numerical map coefficients and contour charts for representative months and hours of the day in 1954 and 1958 are published.