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Physiological Reviews Apr 2000In vivo methods used to study human body composition continue to be developed, along with more advanced reference models that utilize the information obtained with these... (Review)
Review
In vivo methods used to study human body composition continue to be developed, along with more advanced reference models that utilize the information obtained with these technologies. Some methods are well established, with a strong physiological basis for their measurement, whereas others are much more indirect. This review has been structured from the methodological point of view to help the reader understand what can be examined with each technique. The associations between the various in vivo methods (densitometry, dilution, bioelectrical impedance and conductance, whole body counting, neutron activation, X-ray absorptiometry, computer tomography, and magnetic resonance imaging) and the five-level multicompartment model of body composition are described, along with the limitations and advantages of each method. This review also provides an overview of the present status of this field of research in human biology, including examples of reference body composition data for infants, children, adolescents, and adults.
Topics: Adolescent; Adult; Body Composition; Body Weights and Measures; Child; Humans; Infant; Models, Biological; Reference Values
PubMed: 10747204
DOI: 10.1152/physrev.2000.80.2.649 -
Journal of Human Lactation : Official... Feb 2017Breastfeeding provides beneficial health outcomes for infants and their mothers, and increasing its practice is a national priority in many countries. Despite increasing... (Review)
Review
BACKGROUND
Breastfeeding provides beneficial health outcomes for infants and their mothers, and increasing its practice is a national priority in many countries. Despite increasing support to exclusively breastfeed, the prevalence at 6 months remains low. Breastfeeding behavior is influenced by a myriad of determinants, including breastfeeding attitudes, knowledge, and social support. Effective measurement of these determinants is critical to provide optimal support for women throughout the breastfeeding period. However, there are a multitude of available instruments measuring these constructs, which makes identification of an appropriate instrument challenging. Research aim: Our aim was to identify and critically examine the existing instruments measuring breastfeeding attitudes, knowledge, and social support.
METHODS
A total of 16 instruments was identified. Each instrument's purpose, theoretical underpinnings, and validity were analyzed.
RESULTS
An overview, validation and adaptation for use in other settings was assessed for each instrument. Depth of reporting and validation testing differed greatly between instruments.
CONCLUSION
Content, construct, and predictive validity were present for most but not all scales. When selecting and adapting instruments, attention should be paid to domains within the scale, number of items, and adaptation.
Topics: Breast Feeding; Female; Health Knowledge, Attitudes, Practice; Humans; Infant; Infant, Newborn; Psychometrics; Reproducibility of Results; Social Support; Weights and Measures
PubMed: 28135474
DOI: 10.1177/0890334416677029 -
Journal of Healthcare Engineering 2014This paper investigates the measurement of fat-free mass (FFM) by bioimpedance using foot-to-foot impedancemeters (FFI) with plantar electrodes measuring the...
This paper investigates the measurement of fat-free mass (FFM) by bioimpedance using foot-to-foot impedancemeters (FFI) with plantar electrodes measuring the foot-to-foot resistance R34 and hand-to-foot medical impedancemeters. FFM measurements were compared with corresponding data using Dual X-ray absorptiometry (DXA). Equations giving FFM were established using linear multiple regression on DXA data in a first group of 170 subjects. For validation, these equations were used on a second group of 86 subjects, and FFM were compared with DXA data; no significant difference was observed. The same protocol was repeated, but using electrodes on the right hand and foot in standing position to measure the hand to-foot resistance R13. Mean differences with DXA were higher for R13 than for R34. Effect of electrode size and feet position on resistance was also investigated. R34 decreased when electrode area increased or if feet were moved forward. It decreased if feet were moved backward. A proper configuration of contact electrodes can improve measurement accuracy and reproducibility of FFI.
Topics: Adult; Aged; Body Composition; Body Water; Body Weights and Measures; Electric Impedance; Electrodes; Equipment Design; Female; Foot; Hand; Humans; Linear Models; Male; Middle Aged; Young Adult
PubMed: 24918180
DOI: 10.1260/2040-2295.5.2.123 -
PloS One 2022The outcomes anxiety and depression are measured frequently by healthcare providers to assess the impact of a disease, but with numerous instruments. PROMIS item banks...
INTRODUCTION
The outcomes anxiety and depression are measured frequently by healthcare providers to assess the impact of a disease, but with numerous instruments. PROMIS item banks provide an opportunity for standardized measurement. Cross-cultural validity of measures and the availability of reference values are prerequisites for standardized measurement.
METHODS
PROMIS Anxiety and Depression item banks were completed by 1002 representative Dutch persons. To evaluate cross-cultural validity, data from US participants in PROMIS wave 1 were used and differential item functioning (DIF) was investigated, using an iterative hybrid of logistic regression and item response theory. McFadden's pseudo R2-change of 2% was the critical threshold. The impact of any DIF on full item banks and short forms was investigated. To obtain Dutch reference values, T-scores for anxiety and depression were calculated for the complete Dutch sample, and age-group and gender subpopulations. Thresholds corresponding to normal limits, mild, moderate and severe symptoms were computed.
RESULTS
In both item banks, two items had DIF but with minimal impact on population level T-scores for full item banks and short forms. The Dutch general population had a T-score of 49.9 for anxiety and 49.6 for depression, similar to the T-scores of 50.0 of the US general population. T-scores for age-group and gender subpopulations were also similar to T-scores of the US general population. Thresholds for mild, moderate and severe anxiety and depression were set to 55, 60 and 70, identical to US thresholds.
CONCLUSIONS
The limited number of items with DIF and its minimal impact, enables the use of standard (US) item parameters and comparisons of scores between Dutch and US populations. The Dutch reference values provide an important tool for healthcare professionals and researchers to evaluate and interpret symptoms of anxiety and depression, stimulating the uptake of PROMIS measures, and contributing to standardized outcome measurement.
Topics: Anxiety; Depression; Humans; Language; Psychometrics; Quality of Life; Reference Standards; Reference Values; Reproducibility of Results; Surveys and Questionnaires
PubMed: 35998333
DOI: 10.1371/journal.pone.0273287 -
Acta Ophthalmologica Scandinavica Aug 2006
Topics: Data Interpretation, Statistical; Humans; Weights and Measures
PubMed: 16879563
DOI: 10.1111/j.1600-0420.2006.00725.x -
Parkinsonism & Related Disorders Jan 2012In Parkinson's disease (PD), rating scales are used to assess the degree of disease-related disability and to titrate long-term treatment to each phase of the disease.... (Comparative Study)
Comparative Study Review
In Parkinson's disease (PD), rating scales are used to assess the degree of disease-related disability and to titrate long-term treatment to each phase of the disease. Recognition of non-motor symptoms required modification of existing widely used scales to integrate non-motor elements. In addition, new scales have been developed for the assessment of non-motor symptoms. In this article, assessment of PD patients will be discussed, particularly for non-motor symptoms such as pain and fatigue.
Topics: Disability Evaluation; Humans; Parkinson Disease; Severity of Illness Index; Surveys and Questionnaires; Weights and Measures
PubMed: 22166443
DOI: 10.1016/S1353-8020(11)70070-0 -
The AAPS Journal Sep 2006Protein-based pharmaceuticals exhibit a wide range of aggregation phenomena, making it virtually impossible to find any one analytical method that works well in all... (Review)
Review
Protein-based pharmaceuticals exhibit a wide range of aggregation phenomena, making it virtually impossible to find any one analytical method that works well in all cases. Aggregate sizes cover a range from small oligomers to visible "snow" and precipitates, and generally only the smaller species are reversible. It is less widely recognized that aggregates also exhibit a broad spectrum of lifetimes, and the lifetime has important consequences for detection methods. The fact that the measurement itself may destroy or create aggregates poses a major analytical challenge and is a key determinant for method selection. Several examples of some interesting aggregation phenomena and the analytical approaches we have used are presented. In one case, an "aggregate" seen by SEC in stressed samples was shown to actually be a partially denatured monomer using both size-exclusion chromatography with online multiangle laser light scattering (SEC-MALLS) and sedimentation velocity. In a second case, freeze/thaw stress generates transient, metastable oligomers that are extremely sticky and difficult to measure by SEC. By using sedimentation velocity as the "gold standard" a much improved SEC method was developed and used to investigate the temperature-dependent dissociation of these oligomers. For problems with visible particulates, dynamic light scattering has been effective, in our hands, at detecting the precursors to the large, visible particles and tracking the source of stress or damage to particular manufacturing steps.
Topics: Dimerization; Macromolecular Substances; Particle Size; Proteins; Time Factors; Ultracentrifugation; Weights and Measures
PubMed: 17025274
DOI: 10.1208/aapsj080365 -
IEEE Computer Graphics and Applications 2008The Birkhoff aesthetic measure of an object is the ratio between order and complexity. Informational aesthetics describes the interpretation of this measure from an...
The Birkhoff aesthetic measure of an object is the ratio between order and complexity. Informational aesthetics describes the interpretation of this measure from an information-theoretic perspective. From these ideas, the authors define a set of ratios based on information theory and Kolmogorov complexity that can help to quantify the aesthetic experience.
Topics: Art; Cluster Analysis; Comprehension; Creativity; Entropy; Esthetics; Humans; Information Theory; Stochastic Processes; Symbolism; Visual Perception; Weights and Measures
PubMed: 18350930
DOI: 10.1109/mcg.2008.34 -
Anesthesiology Jan 2008
Topics: Deception; Humans; Patient Selection; Randomized Controlled Trials as Topic; Weights and Measures
PubMed: 18156873
DOI: 10.1097/01.anes.0000296718.35703.20 -
Hippocampus Nov 2010Many recent studies have investigated how the structures of the medial temporal lobe (MTL) support recollection and familiarity, which are two processes widely thought... (Review)
Review
Many recent studies have investigated how the structures of the medial temporal lobe (MTL) support recollection and familiarity, which are two processes widely thought to support recognition memory. The behavioral methods that are used to isolate recollection and familiarity in neuroimaging and lesion studies typically assume that recollection is a categorical process and not a continuous process. A categorical process is one that either occurs or does not occur for a particular test item (yielding high confidence and high accuracy when it does occur), whereas a continuous process is one that comes in degrees (yielding varying degrees of confidence and accuracy). Studies suggesting that the hippocampus selectively supports the recollection process (such as those that use the Remember/Know procedure or rely on Receiver Operating Characteristic analysis) generally depend on the categorical view of recollection, but much recent evidence suggests that recollection is a continuous process. If recollection is a continuous process (i.e., if recollection comes in degrees), then evidence that has been taken to mean that the hippocampus selectively supports recollection is also compatible with the idea that the hippocampus supports both recollection and familiarity. We suggest that an alternative method can be used to effectively investigate recollection and familiarity in the MTL, one that is valid whether recollection is a categorical or a continuous process.
Topics: Animals; Confidence Intervals; Humans; Judgment; Memory Disorders; Mental Recall; ROC Curve; Recognition, Psychology; Temporal Lobe; Weights and Measures
PubMed: 20848603
DOI: 10.1002/hipo.20854