Linear Regression Of Weight Research Articles

Linear Weighted Regression and Energy-Aware Greedy Scheduling for Heterogeneous Big Data

Data are presently being produced at an increased speed in different formats, which complicates the design, processing, and evaluation of the data. The MapReduce algorithm is a distributed file system that is used for big data parallel processing. Current implementations of MapReduce assist in data locality along with robustness. In this study, a linear weighted regression and energy-aware greedy scheduling (LWR-EGS) method were combined to handle big data. The LWR-EGS method initially selects tasks for an assignment and then selects the best available machine to identify an optimal solution. With this objective, first, the problem was modeled as an integer linear weighted regression program to choose tasks for the assignment. Then, the best available machines were selected to find the optimal solution. In this manner, the optimization of resources is said to have taken place. Then, an energy efficiency-aware greedy scheduling algorithm was presented to select a position for each task to minimize the total energy consumption of the MapReduce job for big data applications in heterogeneous environments without a significant performance loss. To evaluate the performance, the LWR-EGS method was compared with two related approaches via MapReduce. The experimental results showed that the LWR-EGS method effectively reduced the total energy consumption without producing large scheduling overheads. Moreover, the method also reduced the execution time when compared to state-of-the-art methods. The LWR-EGS method reduced the energy consumption, average processing time, and scheduling overhead by 16%, 20%, and 22%, respectively, compared to existing methods.

Playground equipment-related extremity fractures in children presenting to US emergency departments, 2006\u20132016

BackgroundDespite updated playground equipment and improved industry standards, playgrounds remain a common source of childhood injury. Fractures account for 35% of all playground injuries presenting to emergency departments (EDs). We aimed to examine the time trends and epidemiologic patterns of playground equipment-related extremity fractures in children in the United States.MethodsWe analyzed data from the National Electronic Injury Surveillance System. Children ≤14 years presenting to US emergency departments from 2006 to 2016 with playground equipment-related injuries were included. We used weighted complex survey analysis to describe the epidemiologic patterns and severity of playground equipment-related extremity fractures and Joinpoint linear weighted regression analysis to determine trends in extremity fractures.ResultsAn annual average of 72,889 children were treated in US EDs for playground equipment-related extremity fractures, yielding a national annual incidence rate of 119.2 per 100,000 children. Playground equipment-related extremity fractures accounted for 33.9% of ED presentations and 78.7% of hospitalizations for playground equipment-related injuries. Of patients with playground equipment-related extremity fractures, 11.2% had severe fractures requiring hospitalization. The annual rate of ED visits due to playground equipment-related extremity fractures remained stable (annual rate of change = 0.74, p = 0.14) from 2006 to 2016. Adjusted for age, injuries on monkey bars or climbing gyms were associated with significantly increased odds of extremity fractures in comparison to injuries from other playground equipment (adjusted odds ratio [aOR]: 2.0; 95% CI: 1.9–2.1). Overall, 49.8% of extremity fractures and 54.7% of severe extremity fractures (i.e. those requiring hospitalization) occurred on monkey bars or climbing gyms.ConclusionsDespite enhanced playground safety standards, national rates of playground equipment-related extremity fractures have remained stable in the US. Extremity fractures remain the most common type of playground injury presenting to EDs and most commonly occur on monkey bars and climbing gyms.

Secular trends in weight, stature, and body mass index in Nova Scotia, Canada.

The present study aims to investigate the secular trends of weight, stature, and BMI values in a Nova Scotian sample from 1946 to 1999, with particular focus on how these trends may relate to nutrition and the evolving obesity epidemic. Data were collected from investigative (autopsy) records of 1645 individuals (1287 males, 358 females) of European descent at the Nova Scotia Medical Examiner Service. Secular trends were evaluated by linear regression of weight, stature, and BMI with respect to the year of birth. Further analysis of this sample was based on five time periods (birth cohorts), in order to determine whether dramatic shifts in diet and nutrition affected weight, stature, and BMI. Overall, the results of this study demonstrate positive secular trends in weight, stature, and BMI from 1946 to 1999 in the Nova Scotian sample. Subsequent analysis among different time periods shows a secular increase in the weight of Nova Scotian males from 1946 to 1979, and a subsequent decrease in weight in after 1980. For Nova Scotian females, the results show a secular increase in weight from 1946 to 1989, and a subsequent decrease in weight after 1990. Such secular increases in weight coincide with the global nutrition transition, while recent decreasing median weight values may reflect economic growth and urbanization in Nova Scotia. Overall, the results of the present study indicate that temporal trends in nutrition may have contributed to positive secular changes in weight, stature, and BMI in Nova Scotia, Canada between 1946 and 1999.

Novel liquid chromatography method based on linear weighted regression for the fast determination of isoprostane isomers in plasma samples using sensitive tandem mass spectrometry detection.

A simple, fast, sensitive and accurate methodology based on a LLE followed by liquid chromatography-tandem mass spectrometry for simultaneous determination of four regioisomers (8-iso prostaglandin F2α, 8-iso-15(R)-prostaglandin F2α, 11β-prostaglandin F2α, 15(R)-prostaglandin F2α) in routine analysis of human plasma samples was developed. Isoprostanes are stable products of arachidonic acid peroxidation and are regarded as the most reliable markers of oxidative stress in vivo. Validation of method was performed by evaluation of the key analytical parameters such as: matrix effect, analytical curve, trueness, precision, limits of detection and limits of quantification. As a homoscedasticity was not met for analytical data, weighted linear regression was applied in order to improve the accuracy at the lower end points of calibration curve. The detection limits (LODs) ranged from 1.0 to 2.1pg/mL. For plasma samples spiked with the isoprostanes at the level of 50pg/mL, intra-and interday repeatability ranged from 2.1 to 3.5% and 0.1 to 5.1%, respectively. The applicability of the proposed approach has been verified by monitoring of isoprostane isomers level in plasma samples collected from young patients (n=8) subjected to hyperbaric hyperoxia (100% oxygen at 280kPa(a) for 30min) in a multiplace hyperbaric chamber.

Abstract 115: Improving Door-to-Needle Times in Acute Ischemic Stroke: Interim Findings From Target: Stroke Phase II

Background: The benefits of intravenous tPA in acute ischemic stroke are time-dependent with guidelines recommending a door-to-needle (DTN) time of ≤60 minutes. The implementation of Target: Stroke Phase I in 2010 was associated with an increase in the proportion of patients with DTN times ≤60 minutes in the US from 28.9% in 2009 to 51.0% in 2013. This study aims to assess whether these improvements in DTN times could be maintained or further improved since the launch of Target: Stroke Phase II in Q2 2014. Methods: Target: Stroke Phase II identified and disseminated additional best practice strategies, provided updated clinical decision support tools, and set new hospital recognition goals. Rates of DTN times ≤60 minutes were compared during final 4 quarters of Phase I (Q4 2012-Q3 2013) vs. Phase II (Q2 2014-Q1 2015) and overall by linear weighted regression. Results: There were 99,176 intravenous tPA treated patients from 1228 GWTG-Stroke hospitals. Patient characteristics were similar during Phase I and II. Median DTN time significantly declined from the last 4 quarters of Phase I to the first 4 quarters of Phase II: 61 minutes (IQR 47-81) to 57 minutes (IQR 43-74) (P<0.0001). The % of patients with DTN times ≤60 minutes increased from last 4 quarters of Phase I to Phase II: 49.7% to 58.5%, absolute difference +8.8%, (P<0.0001). The % of patients with DTN times ≤45 minutes also increased from Phase I to Phase II: 22.0% to 29.2%, absolute difference +7.2%, (P<0.0001). The estimated annual rate of increase in patients with DTN times ≤60 minutes was 0.6% per year pre-Target Stroke, 5.6% per year during Phase I, and 8.6% in the first year of Phase II (P<0.0001) (Figure). Conclusions: The timeliness of tPA administration is continuing to improve in GWTG-Stroke hospitals participating in Target: Stroke Phase II. Nevertheless, ongoing quality improvement efforts will be required to meet the goals of ≥75% of patients with DTN times ≤60 minutes and ≥50% of patients with DTN times ≤ 45 minutes.

Linearization of the MS response function: case study for metformin assay in plasma samples for bioequivalence purposes

Calibration data of LC-MS/MS rarely fit the pure least square regression model, especially for large concentration intervals. The response function of the MS instrument is corrected by weighted regression models or logarithms. The choice of a response linearization method is based on results produced through back-interpolation of experimental data and/or evaluation of correlation coefficients. Two bioequivalence studies carried out for pharmaceutical formulations containing metformin gave us the opportunity to appreciate the impact of the MS response linearization method (logarithm and 1/x weighted linear regression) on method quality characteristics. The sample preparation was based on protein precipitation with acetonitrile. Chromatographic separation was achieved on a Zorbax CN column (mobile phase acetonitrile and aqueous 10 m m ammonium acetate solution, pH 3.5). Tandem MS detection was performed on a triple quadrupole spectrometer equipped with an electrospray source, operated under positive-ion mode. The method was validated and used for evaluation of the bioequivalence of formulations containing 500 and 1000 mg metformin. The 500 mg metformin study used logarithms for linearization of the detector response, while the 1000 mg metformin study was based on 1/x linear weighted regression. Data resulting from validations and studies completion were compared with evaluate the impact of the response linearization on the method quality characteristics.

Weight variability, weight change and the incidence of hip fracture: a prospective study of 39,000 middle-aged Norwegians.

There is an increased risk of hip fracture and low bone mass in thin individuals. An association between weight loss and hip fracture has also been reported. In addition, it has been suggested that weight cycling might lead to bone loss. We studied weight variability and change in 19,938 women and 19,151 men who all attended three consecutive health examinations during an average period of 12 years, and assessed the effect of these on the incidence of hip fracture during a subsequent follow-up. Mean age at start of follow-up was 48.6 years in women and 48.5 years in men. For each subject weight variability and linear trend in weight change between the three examinations were assessed by linear regression of weight versus time. The cohort was followed on average 11.6 years from the third examination with respect to hip fracture. During follow-up, 148 hip fractures were identified in women and 59 in men. In both sexes, those with most weight variability had increased risk of fracture (relative risk (RR) = 2.07, 95% confidence interval (CI) 1.24-3.46 in women, and RR = 2.70, 95% CI 1.25-5.86 in men, high vs low quarter of weight variability). Overall, the effect of weight variability was not affected by adjustment for body mass index and linear trend in weight change. In men, there was also an association between weight loss and hip fracture. In summary, high weight variability defined a group with increased risk of hip fracture in this middle-aged cohort. The effect was independent of body mass index and linear trend in weight change. Whether weight variability leads to increased risk of fracture per se or whether it defines a group with otherwise increased risk of fracture is not known, and needs further investigation.

Simple Regression Procedure for Power Function

A direct identification technique based on linear weighted regression analysis is presented to estimate the power function parameters. The computations required are simple, and a hand-held calculator might be sufficient. Parameters of the power function are obtained when the function is fit to published infiltration and soil moisture–pressure head data by: (1) The standard log-linear technique; (2) the proposed linear weighted regression; and (3) a nonlinear least-squares procedure. The described method was found to be superior to the log-linear technique. Athough the linear weighted least-squares method does not fit the experimental data as well as the nonlinear regression, the simplicity and rapidity of the described method compared to a nonlinear procedure makes it an attractice alternative for estimating the power function parameters.

Ratio of actual to predicted weight as an alternative to a power-type weight-height index (Benn index)

In 1971 Benn described a form of relative weight that can be calculated as the ratio of actual to predicted weight from the linear regression of weight on height in a population. He also showed how to compute the exponent for a power-type weight-height index that would be approximately equivalent to this relative weight. Benn did not, however, recommended that this "Benn index" be used instead of relative weight. The properties of these two weight-height functions were investigated in data on 10,606 white men and women aged 18-74 y examined in the 1976-1980 Second National Health and Nutrition Examination Survey (NHANES II). Compared with the power-type index, relative weight was preferable in that it was easier to compute with current software packages, was invariant at standard weight-for-height, and offered more flexibility. The limitations shared by both functions are discussed. Neither function should be used uncritically.

Herd effects on the growth of beef bulls from different sources tested together under grazing conditions

Abstract Data from eight central beef bull performance tests, including a total of 288 bulls, were analysed. Three models were used to analyse sources of variation in start weight and final weight (at approximately 8 and 18 months). All models accounted for the effects of test–year and the linear regression of weight on age, along with effects for herds, sires within herds, and bulls within sires (the error term). Models 1 and 2 accounted for herd in terms of the test bulls' herds of origin, and Model 3 accounted for it in terms of sires' herds of origin. Models 1 and 2 differed in that herd effects were classified across test–years in Model 1 and within test–years in Model 2. Overall linear regressions of age were significant for start weight but not final weight. Correlations between the two weights were high in spite of 270 kg gain being achieved on test. The regression of final weight on start weight was 0.79 kg.kg1. The sizes of overall and residual regressions were...