scholarly journals An expert advantage in detecting unfamiliar visual signals in noise

2020 ◽  
Vol 117 (41) ◽  
pp. 25935-25941
Author(s):  
Zahra Hussain
Keyword(s):  
Response Bias ◽  
External Noise ◽  
Visual Signals ◽  
Control Groups ◽  
Perceptual Skills ◽  
Visual Tasks ◽  
The Difference ◽  
Band Limited ◽  
Clinically Significant ◽  
Contrast Thresholds

Diagnostic radiologists are experts in discriminating and classifying medical images for clinically significant anomalies. Does their perceptual expertise confer an advantage in unfamiliar visual tasks? Here, this issue was investigated by comparing the performance of 10 radiologists and 2 groups of novices on the ability to detect novel visual signals: band-limited textures in noise. Observers performed a yes/no detection task in which texture spatial frequency and external noise levels were varied. The task was performed on two consecutive days. Contrast thresholds and response bias were measured. Contrast thresholds of radiologists were superior to the control groups in all stimulus conditions on both days. Performance improved by an equivalent amount for all groups across days. Response bias differed consistently across stimulus conditions and days but not across groups. The difference in thresholds between the radiologists and control groups suggests that experience in diagnostic medical imaging produces perceptual skills that that transfer beyond the trained domain.

Relationship between total plasma homocysteine and the risk of aneurysms – a meta-analysis

VASA ◽  
2020 ◽  
pp. 1-6
Author(s):  
Hanji Zhang ◽  
Dexin Yin ◽  
Yue Zhao ◽  
Yezhou Li ◽  
Dejiang Yao ◽  
...  
Keyword(s):  
Large Scale ◽  
Meta Analysis ◽  
Single Species ◽  
Total Plasma ◽  
Control Groups ◽  
Randomized Controlled ◽  
Randomized Controlled Studies ◽  
The Difference ◽  
The Relationship ◽  
Healthy Participants

Summary: Our meta-analysis focused on the relationship between homocysteine (Hcy) level and the incidence of aneurysms and looked at the relationship between smoking, hypertension and aneurysms. A systematic literature search of Pubmed, Web of Science, and Embase databases (up to March 31, 2020) resulted in the identification of 19 studies, including 2,629 aneurysm patients and 6,497 healthy participants. Combined analysis of the included studies showed that number of smoking, hypertension and hyperhomocysteinemia (HHcy) in aneurysm patients was higher than that in the control groups, and the total plasma Hcy level in aneurysm patients was also higher. These findings suggest that smoking, hypertension and HHcy may be risk factors for the development and progression of aneurysms. Although the heterogeneity of meta-analysis was significant, it was found that the heterogeneity might come from the difference between race and disease species through subgroup analysis. Large-scale randomized controlled studies of single species and single disease species are needed in the future to supplement the accuracy of the results.

scholarly journals The bowel and beyond: extracolonic findings from CT colonography

2021 ◽  
Author(s):  
Gerard Lambe ◽  
Peter Hughes ◽  
Louise Rice ◽  
Caoimhe McDonnell ◽  
Mark Murphy ◽  
...  
Keyword(s):  
Ct Colonography ◽  
Surgical Intervention ◽  
Potential Significance ◽  
Age And Gender ◽  
Abdominal Aortic ◽  
Life Threatening ◽  
Extracolonic Findings ◽  
The Difference ◽  
Clinically Significant ◽  
And Gender

AbstractCT colonography has emerged as the investigation of choice for suspected colorectal cancer in patients when a colonoscopy in incomplete, is deemed high risk or is declined because of patient preference. Unlike a traditional colonoscopy, it frequently reveals extracolonic as well as colonic findings. Our study aimed to determine the prevalence, characteristics and potential significance of extracolonic findings on CT colonography within our own institution. A retrospective review was performed of 502 patients who underwent CT colonography in our institution between January 1, 2010 and January 4, 2015. Of 502 patients, 60.63% had at least one extracolonic finding. This was close to other similar-sized studies (Kumar et al. Radiology 236(2):519–526, 2005). However, our rate of E4 findings was significantly higher than that reported in larger studies at 5.3%(Pooler et al. AJR 206:313–318, 2016). The difference may be explained by our combination of symptomatic/screening patients or by the age and gender distribution of our population. Our study lends support to the hypothesis that CT colonography may be particularly useful in identifying clinically significant extracolonic findings in symptomatic patients. CT colonography may allow early identification of extracolonic malignancies and life-threatening conditions such as an abdominal aortic aneurysm at a preclinical stage when they are amenable to medical or surgical intervention. However, extracolonic findings may also result in unnecessary investigations for subsequently benign findings.

4971Blood viscosity and its relevance to the diagnosis and management of pulmonary hypertension: a new elephant in the cathlab

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
A Kempny ◽  
K Dimopoulos ◽  
A E Fraisse ◽  
G P Diller ◽  
L C Price ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Cardiac Catheterization ◽  
Clinical Decision Making ◽  
Clinical Decision ◽  
Pulmonary Vasculature ◽  
Pulmonary Vascular Disease ◽  
Significant Difference ◽  
The Difference ◽  
Clinically Significant ◽  
The Relationship

Abstract Background Pulmonary vascular resistance (PVR) is an essential parameter assessed during cardiac catheterization. It is used to confirm pulmonary vascular disease, to assess response to targeted pulmonary hypertension (PH) therapy and to determine the possibility of surgery, such as closure of intra-cardiac shunt or transplantation. While PVR is believed to mainly reflect the properties of the pulmonary vasculature, it is also related to blood viscosity (BV). Objectives We aimed to assess the relationship between measured (mPVR) and viscosity-corrected PVR (cPVR) and its impact on clinical decision-making. Methods We assessed consecutive PH patients undergoing cardiac catheterization. BV was assessed using the Hutton method. Results We included 465 patients (56.6% female, median age 63y). The difference between mPVR and cPVR was highest in patients with abnormal Hb levels (anemic patients: 5.6 [3.4–8.0] vs 7.8Wood Units (WU) [5.1–11.9], P<0.001; patients with raised Hb: 10.8 [6.9–15.4] vs. 7.6WU [4.6–10.8], P<0.001, respectively). Overall, 33.3% patients had a clinically significant (>2.0WU) difference between mPVR and cPVR, and this was more pronounced in those with anemia (52.9%) or raised Hb (77.6%). In patients in the upper quartile for this difference, mPVR and cPVR differed by 4.0WU [3.4–5.2]. Adjustment of PVR required Conclusions We report, herewith, a clinically significant difference between mPVR and cPVR in a third of contemporary patients assessed for PH. This difference is most pronounced in patients with anemia, in whom mPVR significantly underestimates PVR, whereas in most patients with raised Hb, mPVR overestimates it. Our data suggest that routine adjustment for BV is necessary.

Attention Deficit Hyperactivity Disorder, Creativity, and the Effects of Methylphenidate

PEDIATRICS ◽  
1993 ◽  
Vol 91 (4) ◽  
pp. 816-819
Author(s):  
Jeanne B. Funk ◽  
John B. Chessare ◽  
Michael T. Weaver ◽  
Anita R. Exley
Keyword(s):  
Attention Deficit Hyperactivity Disorder ◽  
Attention Deficit ◽  
Repeated Measures ◽  
Creative Thinking ◽  
Adhd Group ◽  
Hyperactivity Disorder ◽  
Significant Difference ◽  
Quasi Experimental ◽  
The Difference ◽  
Clinically Significant

Given that children with attention deficit hyperactivity disorder (ADHD) are more impulsive than peers, this study explored whether they are correspondingly more creative, and whether creativity declines when impulsivity is decreased through methylphenidate (Ritalin) therapy. A repeated-measures quasi-experimental design was used to compare the performance of 19 boys with previously diagnosed ADHD and 21 comparison boys aged 8 through 11 on two administrations of alternate forms of the Torrance Tests of Creative Thinking-Figural (nonverbal). Boys with ADHD received prescribed methylphenidate only for the first session. Overall, mean Torrance summary scores for comparison boys (mean = 115.1, SD = 16.1) were higher than for boys with ADHD (mean = 107.6, SD = 12.7). However, the difference between means was small (7%) and did not meet the 25% criterion for a clinically significant difference. No changes in performance over time (comparison group) or medication state (ADHD group) were observed. These data suggest that, when measured nonverbally, the creative thinking performance of boys with ADHD is not superior to that of peers who do not have ADHD. Regarding the effects of methylphenidate, prescribed therapy did not influence performance on this measure of creative thinking.

scholarly journals The effect of diminazene aceturate on cholinesterase activity in dogs with canine babesiosis

1997 ◽  
Vol 68 (4) ◽  
Author(s):  
R.J. Milner ◽  
F. Reyers ◽  
J.H. Taylor ◽  
J.S. Van den Berg
Keyword(s):  
Treatment Group ◽  
Underlying Mechanism ◽  
Time Interval ◽  
Control Groups ◽  
Canine Babesiosis ◽  
Diminazene Aceturate ◽  
Time Intervals ◽  
Significant Depression ◽  
The Difference ◽  
And Control

A clinical trial was designed to evaluate the effects of diminazene aceturate and its stabiliser antipyrine on serum pseudocholinesterase (PChE) and red blood cell acetylcholinesterase (RBC AChE) in dogs with babesiosis. The trial was conducted on naturally occurring, uncomplicated cases of babesiosis (n = 20) that were randomly allocated to groups receiving a standard therapeutic dose of diminazene aceturate with antipyrine stabiliser (n = 10) or antipyrine alone (n = 10). Blood was drawn immediately before and every 15 minutes for 1 hour after treatment. Plasma PChE showed a 4 % decrease between 0 and 60 min within the treatment group (p < 0.05). No statistically significant differences were found between the treatment and control groups at any of the time intervals for PChE. There was an increase in RBC AChE activity at 15 min in the treatment group (p < 0.05). No significant differences were found between the treatment and control groups at any time interval for RBC AChE. In view of the difference in PChE, samples from additional, new cases (n = 10) of canine babesiosis were collected to identify the affect of the drug over 12 hours. No significant depression was identified over this time interval. The results suggests that the underlying mechanism in producing side-effects, when they do occur, is unlikely to be through cholinesterase depression.

scholarly journals Effects of two different deep digital flexor tenotomy techniques on distal articular angles of equine cadaver forelimbs

2012 ◽  
Vol 42 (11) ◽  
pp. 2005-2010
Author(s):  
Antonio Cezar de Oliveira Dearo ◽  
Vitor Bruno Bianconi Rosa ◽  
Peter Reichmann ◽  
Milton Luis Ribeiro de Oliveira
Keyword(s):  
Quantitative Data ◽  
Statistical Significance ◽  
Surgical Approaches ◽  
Control Groups ◽  
Before And After ◽  
Distal Interphalangeal ◽  
The Difference ◽  
And Control ◽  
Flexor Tenotomy

Deep digital flexor (DDF) tenotomy is a technique employed for years to treat selected disorders of the musculoskeletal system in horses. Although two different surgical approaches (i.e. mid-metacarpal and pastern) have been described for performing the procedure, in vitro quantitative data regarding the modifications induced by either technique on the distal articular angles is lacking. Therefore, the purpose of the study reported here was to investigate the viability of a proposed biomechanical system of induced-traction used to compare the two DDF tenotomy techniques by measuring the distal articular angles of equine cadaver forelimbs. Ten pairs of forelimbs were collected and mounted to a biomechanical system developed to apply traction at the toe level. Dorsal articular angles of the metacarpophalangeal (MP), proximal interphalangeal (PIP) and distal interphalangeal (DIP) joints were determined by geometric lines on radiographs taken before and after performing each technique. Comparisons between each tenotomy group and its own control, for each joint, and between the two tenotomy groups using as variable the difference between the tenotomy and control groups were tested. Despite the lack of statistical significance, the DDF tenotomy technique at the pastern level produced extension, to a lesser and greater extent, of the PIP and DIP joints, respectively when compared to the mid-metacarpal level. No remarkable differences could be observed for the MP joint. The developed traction-induced biomechanical construct seemed to be effective in producing valuable quantitative estimations of the distal articular angles of equine cadaver forelimbs subjected to different DDF tenotomy techniques.

Response Latency with Constant and Variable Interval Schedules

1965 ◽  
Vol 20 (3) ◽  
pp. 969-972 ◽  
Author(s):  
William Bevan ◽  
Donald L. Hardesty ◽  
Lloyd L. Avant
Keyword(s):  
Response Latency ◽  
Average Duration ◽  
Variable Interval ◽  
Visual Signals ◽  
Interval Duration ◽  
Response Latencies ◽  
Interval Group ◽  
The Difference ◽  
The Relationship ◽  
Constant Interval

12 independent groups were used to examine the relationship between response latency and regularity of signal occurrence. In each of 6 groups 20 simple visual signals were presented sequentially at one of 6 constant intervals. Interval durations were 10, 20, 40, 80, 160, or 320 sec. For each constant-interval group tested, there was also a variable-interval group with intervals of the same average duration. For all intervals except one (40 sec.), the variable-interval groups had longer response latencies than the constant-interval groups, the difference in response latency between the constant- and variable-interval groups increasing as a function of the duration of the interval, up to intervals of 160 sec. For both constant- and variable-interval groups, response latency varied directly with interval duration.

scholarly journals Discrete sampling theorem to Shannon’s sampling theorem using the hyperreal numbers R

2021 ◽  
Vol 28 (2) ◽  
pp. 163-182
Author(s):  
José L. Simancas-García ◽  
Kemel George-González
Keyword(s):  
Computational Cost ◽  
Number System ◽  
Sampling Theorem ◽  
Discrete Sampling ◽  
Sampled Signal ◽  
Speed Up ◽  
Shannon’S Sampling Theorem ◽  
The Difference ◽  
Band Limited ◽  
Hyperreal Numbers

Shannon’s sampling theorem is one of the most important results of modern signal theory. It describes the reconstruction of any band-limited signal from a finite number of its samples. On the other hand, although less well known, there is the discrete sampling theorem, proved by Cooley while he was working on the development of an algorithm to speed up the calculations of the discrete Fourier transform. Cooley showed that a sampled signal can be resampled by selecting a smaller number of samples, which reduces computational cost. Then it is possible to reconstruct the original sampled signal using a reverse process. In principle, the two theorems are not related. However, in this paper we will show that in the context of Non Standard Mathematical Analysis (NSA) and Hyperreal Numerical System R, the two theorems are equivalent. The difference between them becomes a matter of scale. With the scale changes that the hyperreal number system allows, the discrete variables and functions become continuous, and Shannon’s sampling theorem emerges from the discrete sampling theorem.

scholarly journals A study on association of polymorphisms in calpain10 and TCF7l2 genes with type 2 diabetes mellitus

Genetika ◽  
2015 ◽  
Vol 47 (1) ◽  
pp. 161-170 ◽  
Author(s):  
Maryam Rezazadeh ◽  
Nasim Sohrabifar ◽  
Hossein Jafari ◽  
Ardabili Mohaddes ◽  
Jalal Gharesouran
Keyword(s):  
Type 2 Diabetes ◽  
Allelic Association ◽  
Diabetic Patients ◽  
Control Groups ◽  
Type2 Diabetes ◽  
North Of Iran ◽  
Calpain 10 ◽  
The Difference ◽  
And Control

Polymorphisms of the Calpain10 and TCF7L2 genes were identified as possible type 2 diabetes susceptibility genetic markers. We conducted a case-control study to evaluate the relation between SNP43 of calpain-10 and rs12255372 and rs7903146 in the TCF7L2 with type2 diabetes in western-north of Iran. The role of these variants in Iranian population was less clear. A total of 202 patients and healthy controls were enrolled to analysis the frequency distribution of Calpain10 and TCF7L2 polymorphisms (SNP43, rs12255372 and rs7903146) using polymerase chain reaction-restriction fragment length polymorphism (PCR - RFLP) method. The frequency of allele A in controls was significantly greater than that of diabetic patients (P=0.031), whereas the difference between distribution of SNP43 genotypes (A/A, A/G, G/G) were non- significant in case and control groups. Non significant association was also observed between G/G, A/G or A/A genotypes and type 2 Diabetes. The frequency of the ?T? allele of rs12255372 (G/T) was significantly associated with type 2 diabetes (OR= 0.55, 95% confidence interval [CI], 1.11-1.51; P<0.001). No allelic association was found for rs7903146(C/T) polymorphism. The distribution of alleles in case and control groups are significantly different indicating the G allele is associated with type 2 diabetes. The rs12255372 (G/T) may be associated with type 2 diabetes.

scholarly journals A Comparison Between Two Types of Radiographic Film for Accuracy of Measurements of Approximal Osseous Defects

2006 ◽  
Vol 7 (3) ◽  
pp. 22-29
Author(s):  
Farah Masood ◽  
Christos Angelopoulos ◽  
Alan Glaros
Keyword(s):  
Bone Loss ◽  
Ground Truth ◽  
Radiographic Film ◽  
Radiographic Images ◽  
Accuracy Of Measurements ◽  
Significant Difference ◽  
Molar Teeth ◽  
The Difference ◽  
Clinically Significant ◽  
Osseous Defects

Abstract Aim The purpose of this study was to compare two types of conventional radiographic film: Ekta-speed plus and Insight (Eastman Kodak Co, Rochester NY, USA) for accuracy of measurements of approximal bone loss. Methods and Materials Four dried human mandibles with complete dentition were selected. Radiographic images were made with a standardized technique. Mesial and distal bone levels on the mandibular premolar and molar teeth were measured on the two types of radiographs (Ekta-speed plus and Insight) by nine observers. The data obtained by the observers were compared with the primary investigators’ corresponding measurements, which served as “the ground truth” for this study. Results The results of the analysis of variance (ANOVA) demonstrated a significant difference for the Ektaspeed plus film (p = .001), but the difference was not clinically significant. The level of intra-rater reliability was high for the observers (0.969 to 0.990). Conclusion Performance of Ekta-speed plus and Insight films was found to be similar. Citation Masood F, Angelopoulos C, Glaros A. A Comparison Between Two Types of Radiographic Film for Accuracy of Measurements of Approximal Osseous Defects. J Contemp Dent Pract 2006 July;(7)3:022-029.

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