Prediction of Human Segment Inertias during Pregnancy

1996 ◽  
Vol 12 (1) ◽  
pp. 15-30 ◽  
Author(s):  
Robert K. Jensen ◽  
Tina Treitz ◽  
Sylvie Doucet
Keyword(s):  
Longitudinal Study ◽  
Repeated Measures ◽  
Center Of Mass ◽  
Predictor Variables ◽  
Radius Of Gyration ◽  
Regression Equations ◽  
Lower Trunk ◽  
The Third ◽  
Cylinder Model ◽  
Linear Regressions

The purpose of this study was to develop prediction equations to estimate mass, radius to the center of mass (CM), and principal moments of the segments during pregnancy. Nonlinear regression equations were determined for the lower trunk, upper trunk, and thigh. The third sampling month of a longitudinal study was used (Sample 1,n= 15). The nonlinear regressions were then used to predict segment inertias above and below the third sampling month (Sample 2, the remaining 74 measurements). For the remaining segments, body mass and segment lengths were used as predictor variables for mass, radius to CM, and radius of gyration about the centroidal axes. The remaining seven segments did not change substantially during pregnancy, and the means of the repeated measures were used for the simple linear regressions. Eighteen of the 28 regressions and all of the CM regressions were significant. With pregnant subjects it is recommended that these regressions be used if application of the elliptical cylinder model is not possible.

scholarly journals Prosody Growth and Reading Comprehension: A Longitudinal Study from 2nd Through the End of 3er Grade // Evolução da prosódia e compreensão da leitura: Um estudo longitudinal do 2º ano ao final do 3º ano de escolaridade

2014 ◽  
Vol 20 (1) ◽  
pp. 5-23 ◽  
Author(s):  
João Lopes ◽  
Maria Madalena Silva ◽  
Louise Spear-Swerling ◽  
Jamie Zibulski
Keyword(s):  
Reading Comprehension ◽  
Longitudinal Study ◽  
Repeated Measures ◽  
Partial Correlation ◽  
Unique Contribution ◽  
Partial Correlation Analysis ◽  
Time Points ◽  
The Third ◽  
Multilevel Growth Model ◽  
Linear Regressions

Prosody is an important but not fully understood component of reading. In this longitudinal study with a sample of 98 Portuguese elementary school children, a multilevel growth model with four repeated measures over time showed steady progress in participants’ reading prosody from the middle of 2nd to the end of 3rd grade. However, children’s growth in this area varied across time points. Results also showed that individual differences in prosody’s scores at baseline affect the performance of most but not of all students. Simple linear regressions showed that the prosody dimension “phrasing/expression” significantly predicted reading comprehension at all time points. Partial correlation analysis showed that when reading rate was accounted for, the unique contribution of prosody to reading comprehension was marginal, except at the third measurement.

Prediction of Infant Segment Inertias

1997 ◽  
Vol 13 (3) ◽  
pp. 287-299 ◽  
Author(s):  
Robert K. Jensen ◽  
Tina Treitz ◽  
Han Sun
Keyword(s):  
Linear Regression ◽  
Nonlinear Regression ◽  
Cross Validation ◽  
Regression Equations ◽  
Cross Sectional ◽  
Moments Of Inertia ◽  
Lower Trunk ◽  
Principal Moments Of Inertia ◽  
The Cross ◽  
Linear Regressions

The purpose of the study was to use the elliptical cylinder model adapted for infants (Sun & Jensen, 1994) with a cross-sectional sample to select appropriate multiple linear regression equations for predicting masses and nonlinear regression equations for predicting principal moments of inertia (Yeadon & Morlock, 1989). The linear and nonlinear predictions were evaluated with an independent cross-validation sample of infants and a sample where inertias ranged below and above the cross-sectional sample. The cross-validation for masses was compared to a cross-validation of four linear regressions for masses developed by Schneider and Zernicke (1992). It is recommended that the linear regression equations developed in this study be used to predict infant segment masses. It is also recommended that the nonlinear regression equations developed in this study be used to predict the principal moments of inertia of all infant segments, other than head Ix and lower trunk Ix and Iy.

A Longitudinal Analysis of Information Literacy Instruction in Canadian Academic Libraries

2013 ◽  
Author(s):  
Heidi Julien
Keyword(s):  
Longitudinal Study ◽  
Information Literacy ◽  
National Survey ◽  
Longitudinal Analysis ◽  
Academic Libraries ◽  
Literacy Instruction ◽  
The Third ◽  
Information Literacy Instruction ◽  
Étude Longitudinale ◽  
Etude Longitudinale

This paper reports a longitudinal study of information literacy instruction (ILI) in Canadian academic libraries, focusing on how instruction is organized, delivered, and evaluated. Results of the third national survey (1995, 2000, and 2005) of ILI are detailed. This research is intended to increase understanding of and to improve ILI.Cet article présente une étude longitudinale sur la formation en recherche d’information (FRI) dans les bibliothèques universitaires canadiennes et est axé sur la manière dont la formation est organisée, offerte et évaluée. Les résultats du troisième sondage national (1995, 2000, 2005) de la FRI sont présentés en détail. Cette recherche est destinée à améliorer la compréhension de la FRI dans le but de son amélioration. 

scholarly journals Myopia control effect of defocus incorporated multiple segments (DIMS) spectacle lens in Chinese children: results of a 3-year follow-up study

2021 ◽  
pp. bjophthalmol-2020-317664
Author(s):  
Carly SY Lam ◽  
Wing Chun Tang ◽  
Paul H Lee ◽  
Han Yu Zhang ◽  
Hua Qi ◽  
...  
Keyword(s):  
Repeated Measures ◽  
Mean Difference ◽  
Historical Control ◽  
Control Group ◽  
Control Effect ◽  
Myopia Progression ◽  
The Third ◽  
Spherical Equivalent Refraction ◽  
Mean Differences ◽  
Myopia Control

AimsTo determine myopia progression in children who continued to wear the defocus incorporated multiple segments (DIMS) lenses or switched from single vision (SV) to DIMS lenses for a 1-year period following a 2-year myopia control trial.Methods128 children participated in this study. The children who had worn DIMS lenses continued to wear DIMS lenses (DIMS group), and children who had worn SV lenses switched to wear DIMS lenses (Control-to-DIMS group). Cycloplegic spherical equivalent refraction (SER) and axial length (AL) were measured at 6-month interval. Historical controls were age matched to the DIMS group at 24 months and used for comparing the third-year changes.ResultsOver 3 years, SER and AL changes in the DIMS group (n=65) were −0.52±0.69D and 0.31±0.26 mm; these changes were not statistically significant over time (repeated measures analysis of variance, p>0.05).SER (−0.04±0. 38D) and AL (0.08±0.12 mm) changes in the Control-to-DIMS group (n=55) in the third year were less compared with the first (mean difference=0.45 ± 0.30D, 0.21±0.11 mm, p<0.001) and second (0.34±0.30D, 0.12±0.10 mm, p<0.001) years.Changes in SER and AL in both groups over that period were significantly less than in the historical control group (DIMS vs historical control: mean difference=−0.18±0.42D, p=0.012; 0.08±0.15 mm, p=0.001; Control-to-DIMS versus historical control: adjusted mean differences=−0.30±0.42D, p<0.001; 0.12±0.16 mm, p<0.001).ConclusionsMyopia control effect was sustained in the third year in children who had used the DIMS spectacles in the previous 2 years and was also shown in the children switching from SV to DIMS lenses.

scholarly journals Trimester effects of source-specific PM10 on birth weight outcomes in the Avon Longitudinal Study of Parents and Children (ALSPAC)

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Yingxin Chen ◽  
Susan Hodgson ◽  
John Gulliver ◽  
Raquel Granell ◽  
A. John Henderson ◽  
...  
Keyword(s):  
Longitudinal Study ◽  
Birth Weight ◽  
Regression Models ◽  
Linear Regression Models ◽  
Exposure Misclassification ◽  
Third Trimester ◽  
Residential History ◽  
The Third ◽  
Parents And Children ◽  
Avon Longitudinal Study

Abstract Background Evidence suggests that exposure to particulate matter with aerodynamic diameter less than 10 μm (PM10) is associated with reduced birth weight, but information is limited on the sources of PM10 and exposure misclassification from assigning exposures to place of residence at birth. Methods Trimester and source-specific PM10 exposures (PM10 from road source, local non-road source, and total source) in pregnancy were estimated using dispersion models and a full maternal residential history for 12,020 births from the Avon longitudinal study of parents and children (ALSPAC) cohort in 1990–1992 in the Bristol area. Information on birth outcomes were obtained from birth records. Maternal sociodemographic and lifestyle factors were obtained from questionnaires. We used linear regression models for continuous outcomes (birth weight, head circumference (HC), and birth length (BL) and logistic regression models for binary outcomes (preterm birth (PTB), term low birth weight (TLBW) and small for gestational age (SGA)). Sensitivity analysis was performed using multiple imputation for missing covariate data. Results After adjustment, interquartile range increases in source specific PM10 from traffic were associated with 17 to 18% increased odds of TLBW in all pregnancy periods. We also found odds of TLBW increased by 40% (OR: 1.40, 95%CI: 1.12, 1.75) and odds of SGA increased by 18% (OR: 1.18, 95%CI: 1.05, 1.32) per IQR (6.54 μg/m3) increase of total PM10 exposure in the third trimester. Conclusion This study adds to evidence that maternal PM10 exposures affect birth weight, with particular concern in relation to exposures to PM10 from road transport sources; results for total PM10 suggest greatest effect in the third trimester. Effect size estimates relate to exposures in the 1990s and are higher than those for recent studies – this may relate to reduced exposure misclassification through use of full residential history information, changes in air pollution toxicity over time and/or residual confounding.

scholarly journals Viability of gait speed test in hospitalized elderly patients

2016 ◽  
Vol 42 (3) ◽  
pp. 196-202 ◽  
Author(s):  
Bruno Prata Martinez ◽  
Anne Karine Menezes Santos Batista ◽  
Isis Resende Ramos ◽  
Júlio Cesar Dantas ◽  
Isabela Barboza Gomes ◽  
...  
Keyword(s):  
Elderly Patients ◽  
Gait Speed ◽  
Repeated Measures ◽  
Maximum Speed ◽  
Actual Performance ◽  
Physical Test ◽  
Speed Test ◽  
The Third ◽  
Hospitalized Elderly ◽  
Hospitalized Elderly Patients

ABSTRACT Objective: The gait speed test (GST) is a physical test that can predict falls and aid in the diagnosis of sarcopenia in the elderly. However, to our knowledge, there have been no studies evaluating its reproducibility in hospitalized elderly patients. The objective of this study was to evaluate the safety and reproducibility of the six-meter GST (6GST) in hospitalized elderly patients. Methods: This repeated measures study involved hospitalized elderly patients (≥ 60 years of age) who underwent the 6GST by the fifth day of hospitalization, were able to walk without assistance, and presented no signs of dyspnea or pain that would prevent them from performing the test. The 6GST was performed three times in sequence, with a rest period between each test, in a level corridor. Gait speed was measured in meters/second. Reproducibility was assessed by comparing the means, intraclass correlation coefficients (ICCs) and Bland-Altman plots. Results: We evaluated 110 elderly patients in a total of 330 tests. All participants completed all of the tests. The comparisons between the speeds obtained during the three tests showed high ICCs and a low mean bias (Bland-Altman plots). The correlation and accuracy were greatest when the mean maximum speed was compared with that obtained in the third test (1.26 ± 0.44 m/s vs. 1.22 ± 0.44 m/s; ICC = 0.99; p = 0.001; mean bias = 0.04; and limits of agreement = −0.27 to 0.15). Conclusions: The 6GST was proven to be safe and to have good reproducibility in this sample of hospitalized elderly patients. The third measurement seems to correspond to the maximum speed, since the first two measurements underestimated the actual performance.

scholarly journals DESENHO DA GRAVIDEZ E SENSIBILIDADE SONORA: CONTRIBUTOS PARA O ESTUDO DA PSICOLOGIA DA GRAVIDEZ

2016 ◽  
Vol 1 (1) ◽  
pp. 25
Author(s):  
Mª Eduarda Salgado Carvalho ◽  
Joao Manuel Rosado de Miranda Justo
Keyword(s):  
Longitudinal Study ◽  
Graphical Representation ◽  
Third Trimester ◽  
Psychological Study ◽  
Portuguese Version ◽  
The Third ◽  
Projective Measures ◽  
Music Representations ◽  
Maternal Orientation ◽  
In Pregnancy

Resumo.Introdução: Esta comunicação pretende descrever um estudo longitudinal acerca da aplicação da Escala do Desenho da Gravidez e da Escala da Sensibilidade Sonora-Musical na Gravidez, ambas construídas e validadas para este estudo, numa amostra de 211 mulheres grávidas aguardando a realização das ecografias do II e do III trimestres de gestação. Objectivos: 1) avaliar a evolução das variáveis do desenho da gravidez e das variáveis sonoro-musicais na passagem do II para o III trimestre e 2) analisar a contribuição de cada uma de estas variáveis para o estudo da psicologia da gravidez. Método: 1) estudo longitudinal comparando as variáveis do desenho da gravidez e a sensibilidade sonoro-musical observadas nos dois momentos de avaliação; 2) estudo correlacional entre cada uma destas variáveis e as variáveis de vinculação materna pré-natal e de orientação materna pré-natal. Instrumentos: Escala do Desenho da Gravidez (Carvalho, 2011), Escala da Sensibilidade Sonora-Musical na Gravidez (Carvalho & Justo, 2013), Escala de Vinculação Materna Pré-natal (versão Portuguesa, Camarneiro & Justo, 2010) e Questionário do Paradigma Placentário (versão portuguesa, Carvalho, 2011). Resultados: Os resultados revelam a existência de diferenças significativas, entre o II e o III trimestres nas variáveis estudadas, apontando para: a) um aumento da sensibilidade sonoro-musical no terceiro trimestre, b) uma evolução da auto-representação da imagem materna no terceiro trimestre e c) um aumento da frequência de representação gráfica da posição de apresentação fetal cefálica da imagem do bebé na passagem para o terceiro trimestre. Observaram-se correlações significativas entre, por um lado, as variáveis da sensibilidade sonoro-musical e as variáveis do desenho da gravidez e, por outro lado, as variáveis de orientação materna pré-natal. Registaram-se correlações significativas entre sensibilidade sonoro-musical, por um lado, e vinculação materna pré-natal e a orientação maternal pré-natal, por outro. Conclusão: Será importante investigar a dialética entre a representação do bebé imaginado através de medidas projectivas maternas e a percepção do comportamento fetal recorrendo à observação ecográfica e a medidas biofísicas e hemodinâmicas.Palavras chave: Gravidez, Escala do Desenho da Gravidez, Escala das Representações Sonoro-Musicais na Gravidez, Escala de Vinculação Materna Pré-Natal, Questionário do Paradigma Placentário.Abstract.Background: This paper aims to describe a longitudinal study about the use of the Drawing Pregnancy Scale and of the Sound-Music Representations in Pregnancy Scale, both of it created and validated in a sample of 211 pregnant women while waiting for sonograms of the II and III trimesters of pregnancy. Aims: 1) to assess, the evolution of variables in drawings of pregnancy and also of sound-music variables, by the transition of the II to the III trimester of gestation and 2) to analyze the contribution of each one of these variables for the psychological study of pregnancy. Method: 1) longitudinal study comparing variables in drawings of pregnancy and sound-music variables at the two moments of assessment; 2) correlational study between each one of these variables and variables of maternal pre-natal attachment and also of maternal pre-natal orientation. Instruments: Drawing Pregnancy Scale (Carvalho, 2011), Sound-Music Representations in Pregnancy Scale (Carvalho & Justo, 2013), Maternal Pre-natal Attachment Scale (Portuguese version, Camarneiro & Justo, 2010) and Placental Paradigm Questionnaire (Portuguese version, Carvalho, 2011). Results: Results show the existence of significant diferences between the II and the III trimestres in some of the variables under analysis, suggesting: a) a increase of the sound-music sensibility by the third trimester, b) an evolution of the maternal image at the third trimester and c) an increase of the frequency of the graphical representation of the cephalic fetal presentation of the baby’s image at the third trimester. Significant correlations were observed between, on one side, the variables of soundmusic sensibility and the variables of the pregnancy drawings and, on another side, variables of prenatal maternal orientation. Significant correlations between sound-music sensibility, on one side, and prenatal maternal attachment and prenatal maternal orientation, on the other side, were found. Conclusion: It will be important to investigate about the representation of the imagined baby through maternal projective measures and the perception of fetal behaviour using sonograms as well as biophysical and hemodynamic measures.Keywords: Pregnancy, Drawing Pregnancy Scale, Sound-Music Representations in Pregnancy Scale, Maternal Pre-natal Attachment Scale, Placental Paradigm Questionnaire.

scholarly journals Analysis of Platform Leveling Systems for Tracked Feller-Buncher Machines

Inventions ◽  
2021 ◽  
Vol 6 (4) ◽  
pp. 96
Author(s):  
Andronov Alexandr ◽  
Bacherikov Ivan ◽  
Zverev Igor
Keyword(s):  
Mathematical Model ◽  
Center Of Mass ◽  
Slope Angle ◽  
Hydraulic Cylinder ◽  
Second Stage ◽  
Modeling Methods ◽  
The Third ◽  
Support Reaction ◽  
Third Stage ◽  
The Stability

The study was devoted to the analysis of feller buncher platform leveling systems. The widespread use of these systems in the design of modern feller-buncher machines makes the study relevant to assess operational efficiency. The analysis was conducted in five stages using analytical and stochastic mathematical modeling methods. In the first stage, the existing layouts of alignment systems were analyzed from the position of force on the hydraulic cylinder rods of the platform tilt drive. The three-cylinder layout scheme, where the force on the hydraulic cylinder rod was 50…60% less than that on the two-cylinder layout, appeared to be the most expedient. In the second stage, a mathematical model for determining changes in the position of the center of mass of the feller-buncher depending on the inclination angle of the platform was derived. In the third stage, a mathematical model was derived for determining the limiting angle of slope of the terrain when the feller buncher moved up the slope. For this purpose, two calculation schemes were considered when the machine moved up the slope without and with a tilted platform. Zero support reaction on the front roller was taken as the stability criterion. In the fourth stage, a mathematical model for determining the limiting angle of slope of the terrain during the roll of the feller-buncher machine was obtained. In the fifth stage, the efficiency of the application of leveling systems was evaluated. A graph of the dependence of changes in the terrain slope angle on the platform slope angle was plotted, and a regression dependence for an approximate estimate was obtained. A regression analysis was also carried out, and dependencies were obtained to determine the weight of a feller-buncher with a leveling system and the added pressure on the ground caused by the increase in the weight of the base machine. The analysis of platform leveling systems showed the effectiveness of their application in the designs of feller-buncher machines, as it allows the machines to work on slopes with an inclination of 50…60% more than without them.

scholarly journals A longitudinal study of perceived stress and cortisol responses in an undergraduate student population from India

2019 ◽  
Author(s):  
Anuradha Batabyal ◽  
Anindita Bhattacharya ◽  
Maria Thaker ◽  
Shomen Mukherjee
Keyword(s):  
Longitudinal Study ◽  
Perceived Stress ◽  
Salivary Cortisol ◽  
Undergraduate Student ◽  
Repeated Measures ◽  
Stressful Events ◽  
Continuous Assessment ◽  
One Year ◽  
Distress Scale ◽  
Psychological Parameters

AbstractYoung adults entering into college experience immense shifts in both personal and professional environments and this may result in some of them experiencing a lot of stress and difficulty in coping with their new surroundings. Such potentially stressful events may trigger multiple psychological as well as physiological effects. The current study investigated multiple psychological parameters such as PSS14 (Perceived Stress Scale), K10 (distress scale) and positive mood measures, along with salivary cortisol levels, in a repeated measures longitudinal study of first year students (~ 19 years of age) enrolled at a residential college in India. Six salivary cortisol samples were collected over a one-year period from 20 students. On each sampling day, a questionnaire designed to evaluate (K10, PSS14 and Mood) psychological parameters was also administered.Overall, men showed a significantly lower level of salivary cortisol compared to women. Men also showed a decrease in perceived stress (PSS14) and distress (K10) with time. However, women reported similar perceived stress and distress levels all year round. Academic stress was reported by the students to be the most important stressor, whereas financial stress was reported the least number of times by all participants. Our results suggest that men seem to have a better capability to adjust to the new environment of a residential program with time. In contrast, women show an elevation in salivary cortisol at the end of the semester (the final assessment stage) in spite of a continuous assessment curricular design. This study not only provides an important glimpse into the sex differences in stress response in the first one year of joining an undergraduate program, but it also provides a valuable longitudinal dataset from the Indian undergraduate student cohort which is lacking in literature.

Achieving the Split Position in a Saut de Chat Leap

2020 ◽  
Vol 35 (2) ◽  
pp. 68-72
Author(s):  
Danielle N Jarvis ◽  
Kornelia Kulig
Keyword(s):  
Repeated Measures ◽  
Center Of Mass ◽  
Peak Height ◽  
Knee Joints ◽  
Similar Time ◽  
Dance Training ◽  
Main Effect ◽  
Hip Flexion ◽  
Post Hoc ◽  
Coordination Patterns

OBJECTIVES: Dancers frequently perform complex jumping skills that involve achieving specific body positions while in the air. An examination of how skilled dancers achieve these aesthetic demands can provide information useful for dance training. The purpose of this study was to examine the temporal coordination of the hip and knee joints during the flight phase of a saut de chat leap, where dancers aim to achieve a split position in the air when the center of mass (COM) reaches peak height. METHODS: Thirty healthy, experienced dancers with 22.5±4.5 years of dance training performed 5 saut de chat leaps. The timing of peak hip and knee joint angles and velocities for the takeoff and leading legs were extracted and compared to the time when COM reached peak height in the leap using a repeated measures ANOVA, with post-hoc comparisons made using paired t-tests. RESULTS: Dancers demonstrated significant differences in timing associated with achieving the split position (main effect p<0.001), with only peak leading leg hip flexion occurring at a similar time to the COM reaching peak height (paired t-test p=0.074). CONCLUSIONS: The results of this study provide insight into coordination patterns used by trained dancers. Trained dancers demonstrate patterns in timing that may be important for successful performance. The hip and knee coordination patterns during flight demonstrate how dancers work to achieve the desired aesthetics of a saut de chat leap. However, it appears that dancers do not reach the full split position at the height of the leap, as would be aesthetically desirable.

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