Regression Lines Using Multiple Measurements from Multiple Patients

1987 ◽  
Vol 66 (4) ◽  
pp. 368
Author(s):  
Steven J. Barker ◽  
Kevin K. Tremper
Keyword(s):  
Multiple Measurements ◽  
Multiple Patients

scholarly journals Pooled testing with replication as a mass testing strategy for the COVID-19 pandemics

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Julius Žilinskas ◽  
Algirdas Lančinskas ◽  
Mario R. Guarracino
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Group Testing ◽  
Testing Strategy ◽  
Testing Technique ◽  
Testing Procedures ◽  
Pooled Testing ◽  
Replication Scheme ◽  
Speed Up ◽  
Multiple Patients

AbstractDuring the COVID-19 pandemic it is essential to test as many people as possible, in order to detect early outbreaks of the infection. Present testing solutions are based on the extraction of RNA from patients using oropharyngeal and nasopharyngeal swabs, and then testing with real-time PCR for the presence of specific RNA filaments identifying the virus. This approach is limited by the availability of reactants, trained technicians and laboratories. One of the ways to speed up the testing procedures is a group testing, where the swabs of multiple patients are grouped together and tested. In this paper we propose to use the group testing technique in conjunction with an advanced replication scheme in which each patient is allocated in two or more groups to reduce the total numbers of tests and to allow testing of even larger numbers of people. Under mild assumptions, a 13 ×  average reduction of tests can be achieved compared to individual testing without delay in time.

scholarly journals Is Micro X-ray Computer Tomography a Suitable Non-Destructive Method for the Characterisation of Dental Materials?

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1271
Author(s):  
Andreas Koenig ◽  
Leonie Schmohl ◽  
Johannes Scheffler ◽  
Florian Fuchs ◽  
Michaela Schulz-Siegmund ◽  
...  
Keyword(s):  
Flexural Strength ◽  
Computer Tomography ◽  
Mechanical Performance ◽  
Dental Materials ◽  
Three Dimensional ◽  
X Rays ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Multiple Measurements ◽  
High Doses

The aim of the study was to investigate the effect of X-rays used in micro X-ray computer tomography (µXCT) on the mechanical performance and microstructure of a variety of dental materials. Standardised bending beams (2 × 2 × 25 mm3) were forwarded to irradiation with an industrial tomograph. Using three-dimensional datasets, the porosity of the materials was quantified and flexural strength was investigated prior to and after irradiation. The thermal properties of irradiated and unirradiated materials were analysed and compared by means of differential scanning calorimetry (DSC). Single µXCT measurements led to a significant decrease in flexural strength of polycarbonate with acrylnitril-butadien-styrol (PC-ABS). No significant influence in flexural strength was identified for resin-based composites (RBCs), poly(methyl methacrylate) (PMMA), and zinc phosphate cement (HAR) after a single irradiation by measurement. However, DSC results suggest that changes in the microstructure of PMMA are possible with increasing radiation doses (multiple measurements, longer measurements, higher output power from the X-ray tube). In summary, it must be assumed that X-ray radiation during µXCT measurement at high doses can lead to changes in the structure and properties of certain polymers.

866 A Lateral Approach Is More Likely to Be Successful Than A Posterior Approach for An Injection to Reach the Subacromial Space

2021 ◽  
Vol 108 (Supplement_2) ◽  
Author(s):  
N Cheyne ◽  
A Jeelani ◽  
M Zeiton ◽  
C Tablot ◽  
E Holt ◽  
...  
Keyword(s):  
Injection Site ◽  
Posterior Approach ◽  
Lateral Approach ◽  
Subacromial Space ◽  
Mean Values ◽  
Shoulder Impingement ◽  
Diagnosis And Therapy ◽  
Subacromial Injection ◽  
Mri Scans ◽  
Multiple Measurements

Abstract Background Subacromial injections are common for diagnosis and therapy of shoulder impingement secondary to subacromial bursitis. We evaluated the likelihood of a successful subacromial injection from both the posterior and lateral injection sites. Method We reviewed 100 MRI scans of the shoulder and recorded measurements in both the sagittal (representative of posterior injection) and coronal (representative of lateral injection) orientations. We compared these to the lengths of standard needles. Multiple measurements were taken: Results Measuring along the angle of the acromion demonstrated shorter mean distances from the lateral injection site. The distance from skin to mid-point of the acromion) provided mean values of 51.4mm for posterior and 40.1mm for lateral. A standard 40mm (green) needle would reach the midpoint of the acromion in 58% of lateral measurements and 23% from posterior. Conclusions Injections are more likely to enter the subacromial space from a lateral rather than a posterior entry point.

Repeatability enhancing method for one-shot LIBS analysis via spectral intensity correction based on probability distribution

2021 ◽  
Author(s):  
Fu Chang ◽  
Jianhong Yang ◽  
Huili Lu ◽  
Haixia Li
Keyword(s):  
Quantitative Analysis ◽  
Probability Distribution ◽  
Spectral Intensity ◽  
Laser Induced Breakdown Spectroscopy ◽  
Breakdown Spectroscopy ◽  
Laser Induced Breakdown ◽  
Multiple Measurements

It is significant to improve the repeatability of quantitative analysis of laser-induced breakdown spectroscopy (LIBS) in one-shot measurement where the skill of averaging is not valid because multiple measurements are...

The triiodothyronine uptake test: an assessment of methods.

1981 ◽  
Vol 27 (7) ◽  
pp. 1272-1276 ◽  
Author(s):  
L R Witherspoon ◽  
S E Shuler ◽  
M M Garcia
Keyword(s):  
Functional Status ◽  
Coefficient Of Variation ◽  
Temperature Effects ◽  
Thyroxine Binding Globulin ◽  
Wide Range ◽  
Free Thyroxine Index ◽  
Total Thyroxine ◽  
Multiple Measurements ◽  
Uptake Test ◽  
Commercial Kits

Abstract How well the free thyroxine index reflects thyroid functional status depends on the degree to which the triiodothyronine uptake test normalizes the effects of thyroxine binding protein concentrations on the total thyroxine concentration. We examined eight triiodothyronine uptake tests in which were used different secondary binders representative of those available in commercial kits. The relation between triiodothyronine uptake and thyroxine-binding globulin concentrations was established by use of sera from euthyroid individuals. We examined the effects of both high (greater than 20 mg/L) and low (less than 10 mg/L) thyroxine-binding globulin concentrations on triiodothyronine uptake. The precision of each assay, expressed as within- and between-run coefficient of variation, was calculated from multiple measurements on high, low, and midrange triiodothyronine uptake serum pools. The effects of variation in temperature and in exposure times were examined. The clinical most useful assays exhibited the ability to reflect a wide range of thyroxine-binding globulin concentrations and demonstrated little or no time or temperature effects.

scholarly journals Assessment of Cracking Widths in a Concrete Wall Based on TIR Radiances of Cracking

Sensors ◽  
2020 ◽  
Vol 20 (17) ◽  
pp. 4980
Author(s):  
Tung-Ching Su
Keyword(s):  
Crack Detection ◽  
Thermal Infrared ◽  
Subtropical Climate ◽  
Architectural Style ◽  
Concrete Wall ◽  
Concrete Crack ◽  
Operation Procedure ◽  
Historic House ◽  
Multiple Measurements ◽  
Infrared Cameras

The techniques of concrete crack detection, as well as assessments based on thermography coupled with ultrasound, have been presented in many works; however, they have generally needed an additional source of thermal infrared (TIR) radiance and have only been applied in laboratories. Considering the accessibility of thermal infrared cameras, a TIR camera (NEC F30W) was employed to detect cracking in the concrete wall of an historic house with a western architectural style in Kinmen, Taiwan, based on the TIR radiances of cracking. An operation procedure involving a series of image processing and statistical analysis processes was designed to evaluate the performance of the TIR camera in the assessment of the cracking width. This procedure using multiple measurements was implemented from March to August 2019, and the t-tests indicated that the temperature differences between the inside and outline of the concrete cracks remained insignificant as the temperature or relative humidity (RH) in the subtropical climate rose. The experimental results of the operation procedure indicated that the maximum focusing range, which is related to the size of the sensor array, and the minimum detectable crack width of a TIR camera should be 1.0 m and 6.0 mm, respectively, in order to derive a linear regression model with a determination coefficient R2 of 0.733 to estimate the cracking widths, based on the temperature gradients. The validation results showed that there was an approximate R2 value of 0.8 and a total root mean square error of ±2.5 mm between the cracking width estimations and the observations.

Least‐squares inversion of in‐situ sonic Q measurements: Stability and resolution

Geophysics ◽  
2004 ◽  
Vol 69 (2) ◽  
pp. 378-385 ◽  
Author(s):  
Aristotelis Dasios ◽  
Clive McCann ◽  
Timothy Astin
Keyword(s):  
High Resolution ◽  
Least Squares ◽  
Instantaneous Frequency ◽  
Spectral Ratio ◽  
Full Waveform ◽  
Multiple Measurements ◽  
Sandstone Reservoir ◽  
Gas Bearing

We minimize the effect of noise and increase both the reliability and the resolution of attenuation estimates obtained from multireceiver full‐waveform sonics. Multiple measurements of effective attenuation were generated from full‐waveform sonic data recorded by an eight‐receiver sonic tool in a gas‐bearing sandstone reservoir using two independent techniques: the logarithmic spectral ratio (LSR) and the instantaneous frequency (IF) method. After rejecting unstable estimates [receiver separation <2 ft (0.61 m)], least‐squares inversion was used to combine the multiple estimates into high‐resolution attenuation logs. The procedure was applied to raw attenuation data obtained with both the LSR and IF methods, and the resulting logs showed that the attenuation estimates obtained for the maximum receiver separation of 3.5 ft (1.07 m) provide a smoothed approximation of the high‐resolution measurements. The approximation is better for the IF method, with the normalized crosscorrelation factor between the low‐ and high‐resolution logs being 0.90 for the IF method and 0.88 for the LSR method.

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