scholarly journals Accurate predictions of postmortem interval using linear regression analyses of gene meter expression data

2017 ◽  
Vol 275 ◽  
pp. 90-101 ◽  
Author(s):  
M. Colby Hunter ◽  
Alex E. Pozhitkov ◽  
Peter A. Noble
Keyword(s):  
Linear Regression ◽  
Postmortem Interval ◽  
Expression Data ◽  
Regression Analyses

scholarly journals Accurate Predictions of Postmortem Interval Using Linear Regression Analyses of Gene Meter Expression Data

2016 ◽  
Author(s):  
Colby M. Hunter ◽  
Alex E. Pozhitkov ◽  
Peter A. Noble
Keyword(s):  
Experimental Design ◽  
Linear Regression ◽  
Postmortem Interval ◽  
Model Organisms ◽  
Regression Analyses ◽  
Individual Gene ◽  
Group Of Seven ◽  
Transcription Profiles ◽  
Gene Transcripts ◽  
Upregulated Genes

AbstractIn criminal and civil investigations, postmortem interval is used as evidence to help sort out circumstances at the time of human death. Many biological, chemical, and physical indicators can be used to determine the postmortem interval, but most are not accurate. Here, we sought to validate an experimental design to accurately predict the time of death by analyzing the expression of hundreds of upregulated genes in two model organisms, the zebrafish and mouse. In a previous study, the death of healthy adults was conducted under strictly controlled conditions to minimize the effects of confounding factors such as lifestyle and temperature. A total of 74,179 microarray probes were calibrated using the Gene Meter approach and the transcriptional profiles of 1,063 significantly upregulated genes were assembled into a time series spanning from life to 48 or 96 h postmortem. In this study, the experimental design involved splitting the gene profiles into training and testing datasets, randomly selecting groups of profiles, determining the modeling parameters of the genes to postmortem time using over- and/or perfectly- defined linear regression analyses, and calculating the fit (R2) and slope of predicted versus actual postmortem times. This design was repeated several thousand to million times to find the top predictive groups of gene transcription profiles. A group of eleven zebrafish genes yielded R2 of 1 and a slope of 0.99, while a group of seven mouse liver genes yielded a R2 of 0.98 and a slope of 0.97, and seven mouse brain genes yielded a R2 of 0.93 and a slope of 0.85. In all cases, groups of gene transcripts yielded better postmortem time predictions than individual gene transcripts. The significance of this study is two-fold: selected groups of upregulated genes provide accurate prediction of postmortem time, and the successfully validated experimental design can now be used to accurately predict postmortem time in cadavers.

scholarly journals Regression analyses of questionnaires in bedside teaching

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Wolf Ramackers ◽  
Julia Victoria Stupak ◽  
Indra Louisa Marcheel ◽  
Annette Tuffs ◽  
Harald Schrem ◽  
...  
Keyword(s):  
Logistic Regression ◽  
Linear Regression ◽  
Survey Data ◽  
Organizational Structures ◽  
Bedside Teaching ◽  
Regression Analyses ◽  
Negative Perception ◽  
Data Analyses ◽  
Main Target ◽  
Relevant Factors

Abstract Background Students’ ratings of bedside teaching courses are difficult to evaluate and to comprehend. Validated systematic analyses of influences on students’ perception and valuation of bedside teaching can serve as the basis for targeted improvements. Methods Six hundred seventy-two observations were conducted in different surgical departments. Survey items covered the categories teacher’s performance, student’s self-perception and organizational structures. Relevant factors for the student overall rating were identified by multivariable linear regression after exclusion of variable correlations > 0.500. The main target for intervention was identified by the 15% worst overall ratings via multivariable logistic regression. Results According to the students the success of bedside teaching depended on their active participation and the teacher’s explanations of pathophysiology. Further items are both relevant to the overall rating and a possible negative perception of the session. In comparison, negative perception of courses (worst 15%) is influenced by fewer variables than overall rating. Variables that appear in both calculations show slight differences in their weighing for their respective endpoints. Conclusion Relevant factors for overall rating and negative perception in bedside teaching can be identified by regression analyses of survey data. Analyses provide the basis for targeted improvement.

Factors of Dementia Caregiver Burden Differentially Contribute to Desire to Institutionalize

2021 ◽  
pp. 089198872110361
Author(s):  
John T. Martin ◽  
Kimberly R. Chapman ◽  
Christopher Was ◽  
Mary Beth Spitznagel
Keyword(s):  
Factor Analysis ◽  
Linear Regression ◽  
Factor Structure ◽  
Caregiver Burden ◽  
Living Arrangements ◽  
Regression Analyses ◽  
Loved One ◽  
Dementia Caregiver ◽  
Future Work ◽  
Made In

The experience of dementia caregiver burden is multidimensional. Little is known about how different aspects of burden contribute to the consideration of moving a loved one to a structured living facility. In the present study, caregiver burden (Zarit Burden Interview; ZBI) and consideration of structured living arrangements (Desire to Institutionalize Scale; DIS) were self-reported by 339 caregivers. Exploratory factor analysis was used to determine the ZBI factor structure; these factors were then examined via hierarchical linear regression for prediction of DIS. Factor analysis indicated a 4-factor ZBI solution: Impact on Life, Guilt, Embarrassment/Frustration, and Escape/Uncertainty. Regression analyses indicated that only Escape/Uncertainty ( p < .001) was associated with DIS. Of the 4 identified factors of caregiver burden, desire to escape the caregiving role was most related to consideration of structured living arrangements. Future work should explore longitudinal contribution of this factor to determine its role in actual changes made in living arrangements.

scholarly journals Correlates of the discrepancy between objective and subjective cognitive functioning in non-demented patients with Parkinson’s disease

2021 ◽  
Author(s):  
Mattia Siciliano ◽  
Lugi Trojano ◽  
Rosa De Micco ◽  
Valeria Sant’Elia ◽  
Alfonso Giordano ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Linear Regression ◽  
Cognitive Functioning ◽  
Rating Scale ◽  
Regression Analyses ◽  
Chi Square ◽  
Cognitive Measure ◽  
Objective Evidence ◽  
Cognitive Discrepancy

Abstract Background Subjective complaints of cognitive deficits are not necessarily consistent with objective evidence of cognitive impairment in Parkinson’s disease (PD). Here we examined the factors associated with the objective-subjective cognitive discrepancy. Methods We consecutively enrolled 90 non-demented patients with PD who completed the Parkinson’s Disease Cognitive Functional Rating Scale (subjective cognitive measure) and the Montreal Cognitive Assessment (MoCA; objective cognitive measure). The patients were classified as “Overestimators”, “Accurate estimators”, and “Underestimators” on the basis of the discrepancy between the objective vs. subjective cognitive measures. To identify the factors distinguishing these groups from each other, we used chi-square tests or one-way analyses of variance, completed by logistic and linear regression analyses. Results Forty-nine patients (54.45%) were classified as “Accurate estimators”, 29 (32.22%) as “Underestimators”, and 12 (13.33%) as “Overestimators”. Relative to the other groups, the “Underestimators” scored higher on the Fatigue Severity Scale (FSS), Beck Depression Inventory (BDI), and Parkinson Anxiety Scale (p < 0.01). Logistic regression confirmed that FSS and BDI scores distinguished the “Underestimators” group from the others (p < 0.05). Linear regression analyses also indicated that FSS and BDI scores positively related to objective-subjective cognitive discrepancy (p < 0.01). “Overestimators” scored lower than other groups on the MoCA’s total score and attention and working memory subscores (p < 0.01). Conclusion In more than 45% of consecutive non-demented patients with PD, we found a ‘mismatch’ between objective and subjective measures of cognitive functioning. Such discrepancy, which was related to the presence of fatigue and depressive symptoms and frontal executive impairments, should be carefully evaluated in clinical setting.

scholarly journals Emotion Processing for Arousal and Neutral Content in Alzheimer's Disease

2009 ◽  
Vol 2009 ◽  
pp. 1-6 ◽  
Author(s):  
Corina Satler ◽  
Carlos Uribe ◽  
Carlos Conde ◽  
Sergio Leme Da-Silva ◽  
Carlos Tomaz
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Linear Regression ◽  
Neuropsychological Tests ◽  
Emotional Processing ◽  
Declarative Memory ◽  
Regression Analyses ◽  
Emotional Information ◽  
Educational Levels ◽  
Emotional Rating

Objective. To assess the ability of Alzheimer's disease (AD) patients to perceive emotional information and to assign subjective emotional rating scores to audiovisual presentations.Materials and Methods. 24 subjects (14 with AD, matched to controls for age and educational levels) were studied. After neuropsychological assessment, they watched a Neutral story and then a story with Emotional content.Results. Recall scores for both stories were significantly lower in AD (Neutral and Emotional:P=.001). CG assigned different emotional scores for each version of the test,P=.001, while ratings of AD did not differ,P=.32. Linear regression analyses determined the best predictors of emotional rating and recognition memory for each group among neuropsychological tests battery.Conclusions. AD patients show changes in emotional processing on declarative memory and a preserved ability to express emotions in face of arousal content. The present findings suggest that these impairments are due to general cognitive decline.

scholarly journals Does physiological distribution of blood parameters in children depend on socioeconomic status? Results of a German cross-sectional study

BMJ Open ◽  
2018 ◽  
Vol 8 (3) ◽  
pp. e019143 ◽  
Author(s):  
Kristin Rieger ◽  
Mandy Vogel ◽  
Christoph Engel ◽  
Uta Ceglarek ◽  
Kristian Harms ◽  
...  
Keyword(s):  
Physical Activity ◽  
Socioeconomic Status ◽  
Linear Regression ◽  
Family Income ◽  
Blood Parameters ◽  
Research Centre ◽  
Regression Analyses ◽  
Pubertal Stage ◽  
Cross Sectional ◽  
Z Scores

ObjectivesIn the present study, we examined the relation between socioeconomic status (SES) and the physiological distribution of iron-related blood parameters.DesignThis is a cross-sectional analysis of longitudinal population-based cohort study.SettingBased on a sample of healthy participants from a German research centre, various blood parameters and values of clinical examinations and questionnaires were collected.ParticipantsA total of 1206 healthy volunteers aged 2.5 to 19 years, one child per family randomly selected, were included.Primary and secondary outcome measuresAssociations between the SES of children by Winkler-Stolzenberg Index (WSI) and its dimensions (income, education, occupation) and iron-related blood parameters (haemoglobin, ferritin and transferrin) were analysed by linear regression analyses. Gender and pubertal stage were included as covariables. Additionally, associations between SES of children by WSI and physical activity (side-to-side jumps, push-ups) as well as body mass index (BMI) were analysed by linear regression analyses.ResultsChildren with high WSI or family income showed significantly increased z-scores for haemoglobin (P=0.046; P<0.001). Children with increased WSI or family income showed significantly lower z-scores for transferrin (P<0.001). There was a significant correlation between haemoglobin and gender (P<0.001) and between transferrin and pubertal stage (P=0.024). Furthermore, physical activity was positively correlated and BMI was negatively correlated with WSI (P<0.001).DiscussionOur data show an association between SES and the distribution of iron-dependent parameters. Lower SES is correlated with lower values for haemoglobin and higher values for transferrin. Furthermore, we demonstrate that physical activity and BMI are associated with SES. Whereas higher SES is correlated with higher values for physical activity and lower BMI. Our parameters are standardised as z-scores with the advantages that the results are comparable across different age groups and present physiological courses.Trial registration numberNCT02550236; Results.

scholarly journals THE ANALYSIS OF OIL CONTENT IN SEDIMENT AND COMMUNITY STRUCTURE OF MACROZOOBENTHOS IN BELAWAN WATERS OF MEDAN CITY, NORTH SUMATERA PROVINCE

2020 ◽  
Vol 3 (2) ◽  
pp. 167-178
Author(s):  
Doli Juna Setia Tanjung ◽  
Bintal Amin ◽  
Syafruddin Nasution
Keyword(s):  
Community Structure ◽  
Linear Regression ◽  
Oil Content ◽  
Diversity Index ◽  
The Other ◽  
Regression Analyses ◽  
Simple Linear Regression ◽  
Dominance Index ◽  
Ocypode Quadrata ◽  
Evenness Index

This research was conducted in March 2019 to determine the oil content in sediment, it’s community structure of macrozoobenthos and it’s a relationship in Belawan Waters of Medan City, North Sumatera. Four sampling stations with five replications in each station were surveyed. The results showed that the average oil content in sediments exceeded the threshold had set by the National Academy of Science. Macrozoobenthos found consists of Ocypode quadrata, Scyla serrate, Rotun dicauda, Penaeus sp, Murex tribulus, and Nassarius olivaccus. The highest abundance was in Station 3 and the lowest was in Station 2. The diversity index in each station was generally very low. Dominance Index in Station 4 was medium, whilst the other stations were high. Evenness index showed in Station 3 and 4 were in high population, Station 1 was in medium population and Station 2 was in low population. Simple linear regression analyses between oil content in sediment with community structure of macrozoobenthos indicated negative correlation ( Y = 10,5-0,0001x , R2 = 0,0004 and r = 0,02 ) which indicated that the higher the oil content, the lower the macrozoobenthos abundance in sediment.

scholarly journals Validation of Velocity Measuring Devices in Velocity Based Strength Training

2021 ◽  
Vol 20 (1) ◽  
pp. 106-118
Author(s):  
Thorben Menrad ◽  
Jürgen Edelmann-Nusser
Keyword(s):  
Linear Regression ◽  
Strength Training ◽  
Mean Value ◽  
Coefficient Of Determination ◽  
Regression Analyses ◽  
Measuring Devices ◽  
Strength Exercises ◽  
Measurement Units ◽  
Velocity Measuring

Abstract To control and monitor strength training with a barbell various systems are on the consumer market. They provide the user with information regarding velocity, acceleration and trajectory of the barbell. Some systems additionally calculate the 1-repetition-maximum (1RM) of exercises and use it to suggest individual intensities for future training. Three systems were tested: GymAware, PUSH Band 2.0 and Vmaxpro. The GymAware system bases on linear position transducers, PUSH Band 2.0 and Vmaxpro base on inertial measurement units. The aim of this paper was to determine the accuracy of the three systems with regard to the determination of the average velocity of each repetition of three barbell strength exercises (squat, barbell rowing, deadlift). The velocity data of the three systems were compared to a Vicon system using linear regression analyses and Bland-Altman-diagrams. In the linear regression analyses the smallest coefficient of determination (R2.) in each exercise can be observed for PUSH Band 2.0. In the Bland-Altman diagrams the mean value of the differences in the average velocities is near zero for all systems and all exercises. PUSH Band 2.0 has the largest differences between the Limits of Agreement. For GymAware and Vmaxpro these differences are comparable.

scholarly journals Thyroid Function Changes and Pubertal Progress in Females: A Longitudinal Study in Iodine-Sufficient Areas of East China

2021 ◽  
Vol 12 ◽  
Author(s):  
Yingying Wang ◽  
Dandan He ◽  
Chaowei Fu ◽  
Xiaolian Dong ◽  
Feng Jiang ◽  
...  
Keyword(s):  
Linear Regression ◽  
Multiple Linear Regression ◽  
Thyroid Function ◽  
Pubertal Development ◽  
Thyroid Stimulating Hormone ◽  
East China ◽  
Regression Analyses ◽  
Free Triiodothyronine ◽  
Serum Tsh

BackgroundThe onset of puberty is influenced by thyroid function, and thyroid hormones (THs) fluctuate substantially during the period of pubertal development. However, it needs to be further clarified how THs change at specific puberty stages and how it influences pubertal development in girls. So far, longitudinal data from China are scarce.MethodsA cohort study was conducted among girls during puberty in iodine-sufficient regions of East China between 2017 to 2019. Serum thyroid stimulating hormone (TSH), free triiodothyronine (FT3), and free thyroxine (FT4) were determined for each participant. Thyroid homeostasis structure parameters (THSPs), including the ratio of FT4 to FT3 (FT4/FT3), Jostel’s TSH index (TSHI), and thyroid feedback quantile-based index (TFQI), were calculated. Puberty category scores (PCS), calculated based on the Puberty Development Scale (PDS), was used to assess the stage of puberty. Girls were grouped into three categories according to PCS changes (△PCS) and six categories according puberty stage (BPFP: pre-pubertal at both baseline and follow-up; BPFL: pre-pubertal at baseline and late-pubertal at follow-up, respectively; BPFT: pre-pubertal at baseline and post-pubertal at follow-up, respectively; BLFL: late-pubertal at both baseline and follow-up; BLFT: late-pubertal at baseline and post-pubertal at follow-up, respectively; BTFT: post-pubertal at both baseline and follow-up). Multiple linear regression analyses were used to evaluate the associations of THs changes with pubertal progress.ResultsThe levels of serum TSH and FT3 decreased while serum FT4 increased during the study period (P&lt;0.001). In multiple linear regression analyses, after adjustment for covariables, FT3 decreased by an additional 0.24 pmol/L (95% CI: -0.47 to -0.01) in the higher △PCS group than the lower △PCS group. Compared with the BLFL group, the BPFT group showed an additional decline in FT3 (β= -0.39 pmol/L, 95%CI: -0.73 to -0.04), the BTFT group showed a lower decline in TSH (β=0.50 mU/L, 95% CI: 0.21 to 0.80) and a lower decline in TSHI (β=0.24, 95%CI: 0.06 to 0.41), respectively. There was no association of △FT4 or △TFQI with △PCS or the puberty pattern.ConclusionsSerum TSH and FT3 decreased while serum FT4 increased among girls during puberty. Both the initial stage and the velocity of pubertal development were related to thyroid hormone fluctuations.

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