Accuracy of subjective measurements made with or without previous scores: an important source of error in serial measurement of subjective states.

This book treats instrumentation used in meteorological surface systems, both on the synoptic scale and the mesoscale, and the instrumentation used in upper air soundings. The text includes material on first- and second-order differential equations as applied to instrument dynamic performance, and required solutions are developed. Sensor physics are emphasized in order to explain how sensors work and to explore the strengths and weaknesses of each design type. The book is organized according to sensor type and function (temperature, humidity, and wind sensors, for example), though several unifying themes are developed for each sensor. Functional diagrams are used to portray sensors as a set of logical functions, and static sensitivity is derived from a sensor's transfer equation, focusing attention on sensor physics and on ways in which particular designs might be improved. Sensor performance specifications are explored, helping to compare various instruments and to tell users what to expect as a reasonable level of performance. Finally, the text examines the critical area of environmental exposure of instruments. In a well-designed, properly installed, and well-maintained meteorological measurement system, exposure problems are usually the largest source of error, making this chapter one of the most useful sections of the book.

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Cholesterol in Serum and Lipoprotein Fractions

Clinical Chemistry ◽

10.1093/clinchem/2.3.145 ◽

1956 ◽

Vol 2 (3) ◽

pp. 145-159 ◽

Cited By ~ 187

Author(s):

Joseph T Anderson ◽

Ancel Keys

Keyword(s):

Human Serum ◽

Total Cholesterol ◽

Filter Paper ◽

Room Temperature ◽

Paper Electrophoresis ◽

Cholesterol Content ◽

Intraindividual Variability ◽

Detailed Data ◽

The Stability ◽

Source Of Error

Abstract 1. Methods are described for the separation, by paper electrophoresis and by cold ethanol, of α- and β-lipoproteins in 0.1 ml. of serum, with subsequent analysis of cholesterol in the separated portions. 2. It is shown that both methods of separation yield separated fractions containing substantially the same amounts of cholesterol. 3. Detailed data are given on the errors of measurement for total cholesterol and for cholesterol in the separated lipoprotein fractions. 4. Studies are reported on the stability of cholesterol in stored serum and on paper electrophoresis strips. It is shown that simple drying on filter paper causes no change in cholesterol content and yields a product that is stable for many weeks at ordinary room temperature. 5. The sources of variability in human serum cholesterol values are examined and it is shown that spontaneous intraindividual variability is a much greater source of error than the errors of measurement with these methods.

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Error estimation on extracorporeal trajectory determination from body scans

International Journal of Legal Medicine ◽

10.1007/s00414-021-02676-y ◽

2021 ◽

Author(s):

F. Riva ◽

U. Buck ◽

K. Buße ◽

R. Hermsen ◽

E. J. A. T. Mattijssen ◽

...

Keyword(s):

Computed Tomography ◽

Soft Tissue ◽

Supine Position ◽

Post Mortem ◽

Surface Scanning ◽

3D Data ◽

Gravitational Pull ◽

Scanned Images ◽

Source Of Error ◽

Trajectory Determination

AbstractThis study explores the magnitude of two sources of error that are introduced when extracorporeal bullet trajectories are based on post-mortem computed tomography (PMCT) and/or surface scanning of a body. The first source of error is caused by an altered gravitational pull on soft tissue, which is introduced when a body is scanned in another position than it had when hit. The second source of error is introduced when scanned images are translated into a virtual representation of the victim’s body. To study the combined magnitude of these errors, virtual shooting trajectories with known vertical angles through five “victims” (live test persons) were simulated. The positions of the simulated wounds on the bodies were marked, with the victims in upright positions. Next, the victims were scanned in supine position, using 3D surface scanning, similar to a body’s position when scanned during a PMCT. Seven experts, used to working with 3D data, were asked to determine the bullet trajectories based on the virtual representations of the bodies. The errors between the known and determined trajectories were analysed and discussed. The results of this study give a feel for the magnitude of the introduced errors and can be used to reconstruct actual shooting incidents using PMCT data.

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Accuracy of a Model-Free Algorithm for Temporal InSAR Tropospheric Correction

Remote Sensing ◽

10.3390/rs13030409 ◽

2021 ◽

Vol 13 (3) ◽

pp. 409

Author(s):

Howard Zebker

Keyword(s):

Time Series ◽

Signal To Noise Ratio ◽

Artifact Reduction ◽

Interferometric Synthetic Aperture Radar ◽

Spatial Properties ◽

Model Free ◽

Weather Model ◽

Phase Variations ◽

Source Of Error ◽

Signal Correlation

Atmospheric propagational phase variations are the dominant source of error for InSAR (interferometric synthetic aperture radar) time series analysis, generally exceeding uncertainties from poor signal to noise ratio or signal correlation. The spatial properties of these errors have been well studied, but, to date, their temporal dependence and correction have received much less attention. Here, we present an evaluation of the magnitude of tropospheric artifacts in derived time series after compensation using an algorithm that requires only the InSAR data. The level of artifact reduction equals or exceeds that from many weather model-based methods, while avoiding the need to globally access fine-scale atmosphere parameters at all times. Our method consists of identifying all points in an InSAR stack with consistently high correlation and computing, and then removing, a fit of the phase at each of these points with respect to elevation. A comparison with GPS truth yields a reduction of three, from a rms misfit of 5–6 to ~2 cm over time. This algorithm can be readily incorporated into InSAR processing flows without the need for outside information.

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Back-Support Exoskeleton Control Strategy for Pulling Activities: Design and Preliminary Evaluation

Designs ◽

10.3390/designs5030039 ◽

2021 ◽

Vol 5 (3) ◽

pp. 39

Author(s):

Maria Lazzaroni ◽

Tommaso Poliero ◽

Matteo Sposito ◽

Stefano Toxiri ◽

Darwin G. Caldwell ◽

...

Keyword(s):

Control Strategy ◽

Muscle Activity ◽

Material Handling ◽

Ease Of Use ◽

Biomechanical Analysis ◽

Perceived Support ◽

Preliminary Evaluation ◽

Subjective Measurements ◽

Spinal Muscles ◽

Forearm Muscle

The execution of manual material handling activities in the workplace exposes workers to large lumbar loads that increase the risk of musculoskeletal disorders and low back pain. In particular, the redesign of the workplace is making the execution of pulling activities more common, as an alternative to lifting and carrying tasks. The biomechanical analysis of the task revealed a substantial activation of the spinal muscles. This suggests that the user may benefit from the assistance of a back-support exoskeleton that reduces the spinal muscle activity and their contribution to lumbar compression. This work addresses this challenge by exploiting the versatility of an active back-support exoskeleton. A control strategy was specifically designed for assisting pulling that modulates the assistive torques using the forearm muscle activity. These torques are expected to adapt to the user’s assistance needs and the pulled object mass, as forearm muscle activity is considered an indicator of grip strength. We devised laboratory experiments to assess the feasibility and effectiveness of the proposed strategy. We found that, for the majority of the subjects, back muscle activity reductions were associated with the exoskeleton use. Furthermore, subjective measurements reveal advantages in terms of perceived support, comfort, ease of use, and intuitiveness.

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Hyaluronic Acid Fillers for Midface Augmentation: A Systematic Review

Facial Plastic Surgery ◽

10.1055/s-0041-1724122 ◽

2021 ◽

Author(s):

Lily N. Trinh ◽

Amar Gupta

Keyword(s):

Systematic Review ◽

Hyaluronic Acid ◽

Subcutaneous Tissue ◽

Age Groups ◽

Medical Subject Headings ◽

Mesh Terms ◽

Full Text Review ◽

Filler Injections ◽

Subjective Measurements ◽

Meta Analyses

AbstractInjectable fillers represent one of the most requested minimally invasive treatments to rejuvenate the aging face, and its popularity is steadily rising. A vast majority of filler treatments are with hyaluronic acid (HA). The aim of this systematic review is to evaluate patient outcomes, safety profile, and administration techniques of various HA fillers for malar augmentation. A systematic review of the published literature was conducted in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines and included PubMed, Embase, and Science Direct databases. Medical Subject Headings (MeSH) terms used were “cheek” OR “midface” OR “malar” and “filler” OR “hyaluronic acid” OR “Juvederm” OR “Restylane” OR “Perlane” OR “Belotero.” The initial search identified 699 articles; 256 duplicates were removed. Additional 12 studies were identified from reference lists. A total of 455 were screened by title and abstract and 387 studies were eliminated based on criteria. Also, 68 articles underwent full-text review, and 18 articles were included in the final review and involved seven different HA formulations. Men and women from many age groups were highly satisfied with their results following HA treatment for midface augmentation up to 24 months. The most common adverse events included bruising, swelling, and tenderness, and typically lasted no more than 2 weeks. Upper cheek filler injections near the zygoma should be placed in the submuscular plane while lower cheek injections should be placed in the subcutaneous tissue. HA is an attractive choice for midface augmentation due to its high patient satisfaction, long-lasting effects, and low side-effect profile. Due to the variability in technique, level of expertise, and subjective measurements across studies, one optimal regimen could not be concluded. However, midface augmentation treatment should be personalized to each patient. Additional clinical trials are required to more conclusively determine the most appropriate approach for this procedure.

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