Wheat bran reduces concentrations of digestible, metabolizable, and net energy in diets fed to pigs, but energy values in wheat bran determined by the difference procedure are not different from values estimated from a linear regression procedure

2016 ◽  
Vol 94 (7) ◽  
pp. 3012 ◽  
Author(s):  
N. W. Jaworski ◽  
D. W. Liu ◽  
D. F. Li ◽  
H. H. Stein
Keyword(s):  
Linear Regression ◽  
Wheat Bran ◽  
Net Energy ◽  
Regression Procedure ◽  
The Difference

scholarly journals Feasibility study of assessing the Preclinical Alzheimer Cognitive Composite (PACC) score via videoconferencing

2021 ◽  
Author(s):  
Giulia Seghezzo ◽  
Yvonne Van Hoecke ◽  
Laura James ◽  
Donna Davoren ◽  
Elizabeth Williamson ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Clinical Practice ◽  
Linear Regression ◽  
Multiple Linear Regression ◽  
Pearson Correlation ◽  
Cognitive Tests ◽  
Strong Positive Correlation ◽  
Pearson Correlation Coefficient ◽  
Face To Face ◽  
The Difference

Abstract Background The Preclinical Alzheimer Cognitive Composite (PACC) is a composite score which can detect the first signs of cognitive impairment, which can be of importance for research and clinical practice. It is designed to be administered in person; however, in-person assessments are costly, and are difficult during the current COVID-19 pandemic. Objective To assess the feasibility of performing the PACC assessment with videoconferencing, and to compare the validity of this remote PACC with the in-person PACC obtained previously. Methods Participants from the HEalth and Ageing Data IN the Game of football (HEADING) Study who had already undergone an in-person assessment were re-contacted and re-assessed remotely. The correlation between the two PACC scores was estimated. The difference between the two PACC scores was calculated and used in multiple linear regression to assess which variables were associated with a difference in PACC scores. Findings Of the 43 participants who were invited to this external study, 28 were re-assessed. The median duration in days between the in-person and the remote assessments was 236.5 days (7.9 months) (IQR 62.5). There was a strong positive correlation between the two assessments for the PACC score, with a Pearson correlation coefficient of 0·82 (95% CI 0·66, 0·98). The multiple linear regression found that the only predictor of the PACC difference was the time between assessments. Interpretation This study provides evidence on the feasibility of performing cognitive tests online, with the PACC tests being successfully administered through videoconferencing. This is relevant, especially during times when face-to-face assessments cannot be performed.

Statistical energy analysis as a tool for quantifying sound and vibration transmission paths

1994 ◽  
Vol 346 (1681) ◽  
pp. 449-464 ◽  
Keyword(s):  
Energy Flow ◽  
Complex Structure ◽  
Linear Equations ◽  
Least Square ◽  
Net Energy ◽  
Sea Temperature ◽  
Energy Flows ◽  
The Difference ◽  
Symmetry Relations ◽  
Loss Factors

When a complex structure is excited in several different ways by different sources, the sea energy balance equations result in a set of linear equations that can be used to calculate loss factors, coupling loss factors or net energy flows and incoming powers. If certain symmetry relations are used, and/or if some prior knowledge about the system is available, the set of linear equations is overdetermined and can be solved by a least square technique. A good indicator for the direction of the energy flow is the SEA temperature of the subsystems. Experiments and computer simulations performed on three plate arrangements gave in general good results when the coupling was weak and there were more than three modes in the frequency band of interest. Not so good results were obtained when a small energy flow has to be measured as the difference of large quantities.

scholarly journals Investigation of Predictability and Influence factors of the Achieved Lenticule Thickness in Small Incision Lenticule Extraction

2019 ◽  
Author(s):  
Fang Wu ◽  
Houfa Yin ◽  
Xinyi Chen ◽  
Yabo Yang
Keyword(s):  
Linear Regression ◽  
Linear Regression Analysis ◽  
Influence Factors ◽  
Small Incision Lenticule Extraction ◽  
Pupil Center ◽  
Small Incision ◽  
Significant Relationships ◽  
Ultrasound Pachymetry ◽  
Lenticule Extraction ◽  
The Difference

Abstract Background To evaluate the differences between the predicted and achieved lenticule thickness (ΔLT) after small incision lenticule extraction (SMILE) surgery and investigate relationships between ΔLT and refractive errors or lenticule depth in SMILE. Methods A total of 184 eyes from 184 consecutive patients who underwent SMILE were included in this prospective study. One eye for each patient was randomly selected and included for statistical analysis. An ultrasound pachymetry measurement and Scheimpflug camera corneal topography were obtained before and at 3 months after SMILE. The achieved lenticule thickness was calculated by comparing the preoperative examinations with postoperative examinations using ultrasound pachymetry and Pentacam software measurements. The pupil center and corneal vertex were selected as the 2 locations for measurement calculation on Pentacam. Analysis of variance (ANOVA) was performed to compare mean pachymetry values using different instruments. An independent t test was performed to evaluate the difference in ΔLT between different cap thicknesses. Linear regression analyses were performed between the VisuMax readout lenticule thicknesses and the measured maximum corneal change, the preoperative spherical equivalent (SE) and each ΔLT. Results On average, the achieved lenticule thickness measured with ultrasound pachymetry was 13.02 ± 8.87 μm thinner than the VisuMax readout lenticule thickness. Linear regression analysis showed significant relationships between the predicted and each achieved lenticule thickness. The preoperative SE was significantly related to each ΔLT (ultrasound: R2 =0.279; at corneal vertex: R2 =0.252; at pupil center R2 =0.246). The ΔLT measured by ultrasound pachymetry was significantly smaller in the thick cap group (cap thickness above 120 μm) than in the thin cap group (P < 0.01). Conclusions An overestimation of achieved lenticule thickness was found in this study. The ΔLT was related to the preoperative SE correction. Furthermore a lager ΔLT was found under a thin cap.

RELEASE OF NON-EXCHANGEABLE SOIL POTASSIUM BY RESIN-EQUILIBRATION AND ITS SIGNIFICANCE FOR CROP GROWTH

1962 ◽  
Vol 42 (2) ◽  
pp. 266-272 ◽  
Author(s):  
T. E. Barber ◽  
B. C. Matthews
Keyword(s):  
Linear Regression ◽  
Ammonium Acetate ◽  
Cation Exchange Resin ◽  
Yield Response ◽  
Exchangeable Potassium ◽  
Quadratic Regression ◽  
Potassium Fertilizer ◽  
Crop Response ◽  
Soil Potassium ◽  
The Difference

The non-exchangeable potassium released by soil after equilibration with cation-exchange resin was determined by extraction of the mixture with neutral ammonium acetate at room temperature and compared with a similar extraction in the absence of resin. The difference obtained following a 2-day equilibration period was called moderately-available potassium.Simple linear regression of yield on exchangeable potassium or exchangeable plus moderately-available potassium accounted for only 16 and 27 per cent respectively of the variability in yield response of corn, wheat, oats and potatoes to potassium fertilizer in the field. Multiple linear regression of yield on exchangeable and moderately-available potassium accounted for an average of 37 per cent of the variation in crop response; but a multiple quadratic regression of Log (100-per cent yield) on exchangeable and moderately-available potassium accounted for an average of 56 per cent of the variability in Log (100-per cent yield). Multiple quadratic regression of absolute yield or per cent yield on exchangeable and moderately-available potassium accounted for 46 and 50 per cent, respectively, of the variability in crop response to potassium fertilizer.

scholarly journals PM2.5 Concentration Estimation Based on Image Processing Schemes and Simple Linear Regression

Sensors ◽  
2020 ◽  
Vol 20 (8) ◽  
pp. 2423 ◽  
Author(s):  
Jiun-Jian Liaw ◽  
Yung-Fa Huang ◽  
Cheng-Hsiung Hsieh ◽  
Dung-Ching Lin ◽  
Chin-Hsiang Luo
Keyword(s):  
Image Processing ◽  
Linear Regression ◽  
Regression Model ◽  
Linear Regression Model ◽  
Simple Linear Regression ◽  
Simple Linear Regression Model ◽  
Concentration Estimation ◽  
Single Feature ◽  
The Difference ◽  
Pm2.5 Concentration

Fine aerosols with a diameter of less than 2.5 microns (PM2.5) have a significant negative impact on human health. However, their measurement devices or instruments are usually expensive and complicated operations are required, so a simple and effective way for measuring the PM2.5 concentration is needed. To relieve this problem, this paper attempts to provide an easy alternative approach to PM2.5 concentration estimation. The proposed approach is based on image processing schemes and a simple linear regression model. It uses images with a high and low PM2.5 concentration to obtain the difference between these images. The difference is applied to find the region with the greatest impact. The approach is described in two stages. First, a series of image processing schemes are employed to automatically select the region of interest (RoI) for PM2.5 concentration estimation. Through the selected RoI, a single feature is obtained. Second, by employing the single feature, a simple linear regression model is used and applied to PM2.5 concentration estimation. The proposed approach is verified by the real-world open data released by Taiwan’s government. The proposed scheme is not expected to replace component analysis using physical or chemical techniques. We have tried to provide a cheaper and easier way to conduct PM2.5 estimation with an acceptable performance more efficiently. To achieve this, further work will be conducted and is summarized at the end of this paper.

Estimating Linear Trends: Simple Linear Regression versus Epoch Differences

2015 ◽  
Vol 28 (24) ◽  
pp. 9969-9976 ◽  
Author(s):  
Elizabeth A. Barnes ◽  
Randal J. Barnes
Keyword(s):  
Time Series ◽  
Linear Regression ◽  
Linear Trend ◽  
Simple Linear Regression ◽  
Difference Estimator ◽  
First Order ◽  
Epoch Length ◽  
Average Value ◽  
The Difference ◽  
Linear Regression Estimator

Abstract Two common approaches for estimating a linear trend are 1) simple linear regression and 2) the epoch difference with possibly unequal epoch lengths. The epoch difference estimator for epochs of length M is defined as the difference between the average value over the last M time steps and the average value over the first M time steps divided by N − M, where N is the length of the time series. Both simple linear regression and the epoch difference are unbiased estimators for the trend; however, it is demonstrated that the variance of the linear regression estimator is always smaller than the variance of the epoch difference estimator for first-order autoregressive [AR(1)] time series with lag-1 autocorrelations less than about 0.85. It is further shown that under most circumstances if the epoch difference estimator is applied, the optimal epoch lengths are equal and approximately one-third the length of the time series. Additional results are given for the optimal epoch length at one end when the epoch length at the other end is constrained.

Anthropometric and other factors affecting respiratory responses to carbon dioxide in New Guineans

1974 ◽  
Vol 268 (893) ◽  
pp. 363-373 ◽  
Keyword(s):  
Linear Regression ◽  
Tidal Volume ◽  
Vital Capacity ◽  
Breathing Pattern ◽  
Respiratory Control ◽  
Control Mechanisms ◽  
Men And Women ◽  
Factors Affecting ◽  
Residual Difference ◽  
The Difference

A CO 2 rebreathing test was used to determine the breathing pattern and the ventilatory response to CO 2 in 15 Caucasians and 140 New Guineans (coastal and highland men and women, and male highlanders on the coast). The breathing pattern was analysed in terms of the slope and intercept ( M and K ) of the linear regression of ventilation on tidal volume: V e = M ( V t — K ), and of the interpolated tidal volume at a ventilation of 30 1 min-1 (V t,30 ). Each of these parameters bears a common relation to vital capacity throughout the groups studied. The CO 2 response was analysed in terms of the slope and intercept ( S and B ) of the linear regression of ventilation on P CO 2 : V e = S ( P CO 2 — B ). B is lower in women than in men. S is a function of vital capacity, and this relation accounts for the difference in CO 2 sensitivity between men and women, and for part of the difference between the resident highland and coastal groups; part is attributable to altitude-adaptation and disappears on migration. In all these respects, New Guineans resemble Caucasians, and the results demonstrate the importance of the size of the vital capacity in influencing the setting of the respiratory control mechanisms. In addition, there is a residual difference between the ethnic groups, with the New Guineans having the lower CO 2 sensitivities and thus a greater tolerance of CO 2 loads.

scholarly journals Internal Astigmatism and Its Role in the Growth of Axial Length in School-Age Children

2018 ◽  
Vol 2018 ◽  
pp. 1-5 ◽  
Author(s):  
Liangcheng Wu ◽  
Chenghai Weng ◽  
Fei Xia ◽  
Xiaoying Wang ◽  
Xingtao Zhou
Keyword(s):  
Risk Factor ◽  
Linear Regression ◽  
Primary School ◽  
Axial Length ◽  
Regression Line ◽  
School Age Children ◽  
School Age ◽  
Paired Samples ◽  
The Difference

Objectives. To explore the role of internal astigmatism (IA) in the growth of axial length (AL) in school-age children. Methods. Total astigmatism (TA), corneal astigmatism (CA), and AL of all children in Jing’an District 2nd Centre Primary School in Shanghai were measured. In IA, the difference between TA and CA was also calculated using vector analysis. The association of axial length with IA, genders, and age was analyzed using linear regression. The difference of IA between both eyes was also calculated. The AL between both eyes was compared using paired samples t-test when DIA = 0 D, <0.5 D, and ≥0.5 D. Results. Six hundred and twelve cases (98.23%) in 623 children aged 7–12 yrs older entered into the study. Genders, age, and IA all affected AL. This could be represented by a linear regression line in the form AL = 21.46 − 0.43∗gender + 0.22∗age + 0.46∗IA (male = 1, female = 2; t=7.01, P<0.01 for sex; t=11.6, P<0.01 for age; and t=6.6, P<0.01 for IA; R2=0.16). The AL in the eye with larger IA was also longer when DIA was larger than 0.5 D (t=2.65, P<0.01). Conclusions. IA was observed to be associated with AL and might be a risk factor of the onset and progress of myopia in school-age children.

Effect of age on energy storage during prehibernation swarming in little brown bats (Myotis lucifugus)

2009 ◽  
Vol 87 (6) ◽  
pp. 515-519 ◽  
Author(s):  
L. P. McGuire ◽  
M. B. Fenton ◽  
C. G. Guglielmo
Keyword(s):  
Nutrient Intake ◽  
Age Groups ◽  
Myotis Lucifugus ◽  
Net Energy ◽  
Energy Expenditures ◽  
Fat Stores ◽  
The Difference ◽  
Plasma Metabolite ◽  
Net Energy Gain ◽  
Little Brown Bats

At temperate latitudes insectivorous bats face substantial nutritional demands prior to hibernation. As temperature decreases and availability of insect prey declines, bats must deposit nutrient stores for hibernation. The use of torpor allows bats to limit energy expenditures resulting in a net energy gain despite decreased energy intake. However, subadult bats have lower initial fat stores than adults and may have greater difficulty depositing sufficient nutrient stores to survive the winter. We used plasma metabolite analysis to determine the fueling performance of little brown bats ( Myotis lucifugus (LeConte, 1831)) during swarming to see if subadults compensated for the increased challenges by increased feeding throughout the swarming period. During the period of our study (August and September), adult bats gained mass, while subadults lost mass. There was, however, no difference in nutrient intake of the age groups as indicated by plasma metabolite concentrations. The number of bats using torpor while roosting in the hibernaculum by day increased exponentially coincident with the onset of mating and a decrease in nutrient intake. The results are consistent with wild bats using torpor to minimize energy expenditure and compensate for lower nutrient intake. The difference in mass change for adults and subadults despite the same nutrient intake indicates that subadults incur greater energetic costs.

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