scholarly journals Allowing a Possible Margin of Error When Assessing Student Skills in Spinous Process Location

2011 ◽  
Vol 25 (2) ◽  
pp. 182-185 ◽  
Author(s):  
John Hart ◽  
Cheneir Neely

Introduction: Spinal palpation is subject to inconsistency between examiners. When testing students on the location of vertebral spinous processes, faculty examiners may wish to allow for a margin of error that is observed between experienced practitioners. This study attempts to determine such a margin of error for selected vertebral levels that could be allowed in testing situations at Sherman Chiropractic College. This could serve as a model for other chiropractic colleges in determining their margins of error. Methods: Two faculty clinicians palpated spinous processes at four different vertebral levels (C2, T3, T9, and L2) on 18 student volunteers. Differences for each vertebral level, along with one, two, and three standard deviations, were calculated. Results: Average differences between examiners increased caudally, as follows: C2, 4.23 ± 3.77 mm; T3, 13.41 ± 10.53 mm; T9, 18.17 ± 17.62 mm; L2, 18.70 ± 16.58 mm. Discussion: In this study, faculty examiners exhibited variation in their locations of spinous processes for these vertebrae. These variations could be allowed when assessing student skills in locating these spinous processes at this chiropractic college. Conclusion: In this study, differences between examiners plus or minus one standard deviation ranged from 4.23 ± 3.77 mm for C2 to 18.70 ± 16.58 mm for L2. The concept of margin of error should be considered by faculty examiners when assessing the skill of students in locating the spinous process of various vertebral levels.

Author(s):  
Ariel Medina ◽  
Maruti R. Gudavalli ◽  
P. K. Raju ◽  
Gregory D. Cramer

The objective of this research project was to develop an ultrasonic based testing system and evaluate its application on human volunteers to locate and assess the distance between adjacent lumbar vertebrae. Tests were performed on ten volunteers aged between 19 and 29 years old during two sessions. The participants were asked to lie face down on a table with lower back section uncovered while the tests were executed. A computer controlled ultrasonic system was designed for this application. A single element 3.5 MHz immersion transducer held by a customized assembly was used to propagate and receive the ultrasonic signals. The transducer was moved along the assembly to fully scan at least two contiguous spinous processes. A Lab view based program was designed to generate a two-dimensional image (B-scan) that display the shape and position of the bone tips as well as the distance between them. The standard deviation obtained from the measurements of the distance between the tips of the spinous processes of human subjects, in a given session ranged from 0.1–0.48mm. The difference between two sessions had a mean of 0.85–0.95 mm and a standard deviation of 0.87–1.03mm with reliability coefficients greater than 0.95. The study demonstrated the viability of utilizing ultrasound to precisely measure the distance between spinous processes of adjacent lumbar vertebrae.


2020 ◽  
Vol 38 (3) ◽  
Author(s):  
Ainhoa Fernández-Pérez ◽  
María de las Nieves López-García ◽  
José Pedro Ramos Requena

In this paper we present a non-conventional statistical arbitrage technique based in varying the number of standard deviations used to carry the trading strategy. We will show how values of 1 and 1,2 in the standard deviation provide better results that the classic strategy of Gatev et al (2006). An empirical application is performance using data of the FST100 index during the period 2010 to June 2019.


2020 ◽  
Vol 11 (1) ◽  
pp. 301
Author(s):  
Sławomir Paśko ◽  
Wojciech Glinkowski

Scoliosis is a three-dimensional trunk and spinal deformity. Patient evaluation is essential for the decision-making process and determines the selection of specific and adequate treatment. The diagnosis requires a radiological evaluation that exposes patients to radiation. This exposure reaches hazardous levels when numerous, repetitive radiographic studies are required for diagnostics, monitoring, and treatment. Technological improvements in radiographic devices have significantly reduced radiation exposure, but the risk for patients remains. Optical three-dimensional surface topography (3D ST) measurement systems that use surface topography (ST) to screen, diagnose, and monitor scoliosis are safer alternatives to radiography. The study aimed to show that the combination of plain X-ray and 3D ST scans allows for an approximate presentation of the vertebral column spinous processes line in space to determine the shape of the spine’s deformity in scoliosis patients. Twelve patients diagnosed with scoliosis, aged 13.1 ± 4.5 years (range: 9 to 20 years) (mean: Cobb angle 17.8°, SD: ±9.5°) were enrolled in the study. Patients were diagnosed using full-spine X-ray and whole torso 3D ST. The novel three-dimensional assessment of the spinous process lines by merging 3D ST and X-ray data in patients with scoliosis was implemented. The method’s expected uncertainty is less than 5 mm, which is better than the norm for a standard measurement tool. The presented accuracy level is considered adequate; the proposed solution is accurate enough to monitor the changes in the shape of scoliosis’s spinous processes line. The proposed method allows for a relatively precise calculation of the spinous process lines based on a three-dimensional point cloud obtained with a four-directional, three-dimensional structured light diagnostic system and a single X-ray image. The method may help reduce patients’ total radiation exposure and avoid one X-ray in the sagittal projection if biplanar radiograms are required for reconstructing the three-dimensional line of the spinous processes line.


Biomolecules ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 912
Author(s):  
Saadullah Khattak ◽  
Mohd Ahmar Rauf ◽  
Qamar Zaman ◽  
Yasir Ali ◽  
Shabeen Fatima ◽  
...  

The ongoing outbreak of coronavirus disease COVID-19 is significantly implicated by global heterogeneity in the genome organization of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The causative agents of global heterogeneity in the whole genome of SARS-CoV-2 are not well characterized due to the lack of comparative study of a large enough sample size from around the globe to reduce the standard deviation to the acceptable margin of error. To better understand the SARS-CoV-2 genome architecture, we have performed a comprehensive analysis of codon usage bias of sixty (60) strains to get a snapshot of its global heterogeneity. Our study shows a relatively low codon usage bias in the SARS-CoV-2 viral genome globally, with nearly all the over-preferred codons’ A.U. ended. We concluded that the SARS-CoV-2 genome is primarily shaped by mutation pressure; however, marginal selection pressure cannot be overlooked. Within the A/U rich virus genomes of SARS-CoV-2, the standard deviation in G.C. (42.91% ± 5.84%) and the GC3 value (30.14% ± 6.93%) points towards global heterogeneity of the virus. Several SARS-CoV-2 viral strains were originated from different viral lineages at the exact geographic location also supports this fact. Taking all together, these findings suggest that the general root ancestry of the global genomes are different with different genome’s level adaptation to host. This research may provide new insights into the codon patterns, host adaptation, and global heterogeneity of SARS-CoV-2.


1974 ◽  
Vol 18 (2) ◽  
pp. 116-116
Author(s):  
Helmut T. Zwahlen

Twelve subjects (20–37 years old) were tested in the laboratory and eleven out of these were also tested in a car in the field, first under a no alcohol condition and then under an alcohol condition (approximately 0.10% BAC). In the laboratory the subjects simple and choice reaction times for two uncertainty modes were measured and their information processing rates (3 bits unsertainty) were determined. In the field the subjects driving skill for driving through a gap with 20 inches total clearance at 20 MPH was measured, as well as their static visual perceptual capabilities and risk acceptance decisions for a 46 feet viewing distance using psychophysical experimental methods. Based upon the driving skill measure (standard deviation of centerline deviations in the gap), the mean of the psychometric visual gap perception function and the mean of the psychometric gap risk acceptance function, the “Safety Distance” and the “Driver Safety Index” (DSI) were obtained. Based upon a statistical analysis of the data we may conclude first that the effects of alcohol (approximately 0.10% BAC) vary widely from one subject to another (slighthly improved performance to highly impaired performance) and that the changes in the group averages of the means and standard deviations of the psychometric visual perception and risk acceptance functions, the driving skill distributions, the “Safety Distances” and the DSI's for the subjects (although all changes in the group averages are in the expected direction) are statistically not significant (α = .05). Second, the group average of the means of the choice reaction times for the subjects increased by 5% under the alcohol condition (statistically significant, α = .05), but more important the group average of the standard deviations of the choice reaction times for the subjects increased by 23% (statistically significant, α = .05). The group average of the information processing rates for the subjects decreased by 3% (statistically not significant, α = .05) under the alcohol condition. A system model in which the system demands on the driver are represented in terms of choice reaction times is used to demonstrate that the increase in performance variability (expressed by the standard deviation of choice reaction times) under the influence of alcohol provides a much better explanation for the higher accident involvement than the historically most frequently used rather small increase in average performance (expressed by the mean of choice reaction times).


2021 ◽  
Vol 14 (2) ◽  
pp. 63
Author(s):  
Nuttakan Pakprod ◽  
Kanokrat Jirasatjanukul ◽  
Damrong Tumthong ◽  
Prapa Amklad ◽  
Wipa Lekchom

The objective of this research is to study the results of activities to increase the scores of Ordinary National Education Test. Cluster; teachers of Phetchaburi Rajabhat University comparing the results of Ordinary National Education Test in 2017-2018 and studying the satisfaction of the activities. The target group is 49 schools in Phetchaburi and Prachuap Khiri Khan Provinces, data were analyzed using mean and standard deviation. The study found that the difference of the scores of the Ordinary National Education Test was higher in 32 schools and there is a difference in scores of Ordinary National Education Test tests lower by 2 schools, representing 94.12, with the satisfaction of the participation in the activity of increasing the basic educational testing at the basic level is at a high level with an average of 4.22, standard deviations 0.73, which the participants are satisfied with the process. The process of organizing activities was at the highest with an average of 4.28, standard deviations 0.76 and continues organizing activities to increase the scores of Ordinary National Education Test.


2020 ◽  
pp. 393-421
Author(s):  
Sandra Halperin ◽  
Oliver Heath

This chapter deals with quantitative analysis, and especially description and inference. It introduces the reader to the principles of quantitative research and offers a step-by-step guide on how to use and interpret a range of commonly used techniques. The first part of the chapter considers the building blocks of quantitative analysis, with particular emphasis on different ways of summarizing data, both graphically and with tables, and ways of describing the distribution of one variable using univariate statistics. Two important measures are discussed: the mean and the standard deviation. After elaborating on descriptive statistics, the chapter explores inferential statistics and explains how to make generalizations. It also presents the concept of confidence intervals, more commonly known as the margin of error, and measures of central tendency.


2005 ◽  
Vol 88 (5) ◽  
pp. 1503-1510 ◽  
Author(s):  
Foster D McClure ◽  
Jung K Lee

Abstract Sample size formulas are developed to estimate the repeatability and reproducibility standard deviations (sr and sR) such that the actual error in (sr and sR) relative to their respective true values, σr and σR, are at predefined levels. The statistical consequences associated with AOAC INTERNATIONAL required sample size to validate an analytical method are discussed. In addition, formulas to estimate the uncertainties of (sr and sR) were derived and are provided as supporting documentation.Formula for the Number of Replicates Required for a Specified Margin of Relative Error in the Estimate of the Repeatability Standard Deviation


1998 ◽  
Vol 21 (3) ◽  
pp. 338-339
Author(s):  
Douglas Wahlsten ◽  
Katherine M. Bishop

Sex dimorphism occurs when group means differ by four or more standard deviations. However, the average size of the corpus callosum is greater in males by about one standard deviation in rats, 0.2 standard deviation in humans, and virtually zero in mice. Furthermore, variations in corpus callosum size are related to brain size and are not sex specific.


Radiocarbon ◽  
1964 ◽  
Vol 6 ◽  
pp. 1-24 ◽  
Author(s):  
H. R. Crane ◽  
James B. Griffin

The following is a list of dates obtained since the time of the compilation of List VIII in December 1962. The method is essentially the same as that used for the work described in the previous list. Two CO2-CS2 Geiger counter systems are used. The equipment and counting techniques have been described elsewhere (Crane, 1961a, 1961b). The dates and the estimates of error in this list follow the practice recommended by the International Radiocarbon Dating Conference of 1962, in that (a) dates are computed on the basis of the Libby half life, 5570 years, (b) a.d. 1950 is used as the zero of the age scale and (c) the errors quoted are the standard deviations obtained from the numbers of counts only. In previous Michigan date lists up to and including VII we have quoted errors at least twice as great as the statistical errors of counting, in order to take account of other errors in the over-all process. If the reader wishes to obtain a standard deviation figure which will allow ample room for the many other sources of error in the dating process, we suggest he double the figures that are given in this list. Where there is no comment, it is because the submitter of the sample had none to make.We wish to acknowledge the help of Patricia Dahlstrom in preparing chemical samples and Roscoe Wilmeth in preparing the descriptions. The descriptions and comments are essentially those of persons submitting the samples.


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