scholarly journals A Comparison of Particulate Matter Exposures Between a Student’s Private Vehicle and Public Bus Transit Commutes

2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Tirth M Patel
Keyword(s):  
Air Pollution ◽  
Public Transportation ◽  
Statistical Significance ◽  
Ultrafine Particle ◽  
P Value ◽  
Air Exchange Rate ◽  
Private Vehicle ◽  
Box Plots ◽  
Wide Range ◽  
Significance Levels

Daily commuters of public transportation and private vehicles are exposed to a wide range of traffic-related air pollution (TRAP). However, evidence of differences between commuting method has been building. In this study, the personal ultrafine particle (UFP) and black carbon (BC) air pollution exposures of a high school student were measured during their daily commute. In total, 39 commutes made between the student’s home and school were measured. These commutes were either by bus or private vehicle. Data was analysed using box plots and T-tests of statistical significance. Levels of BC were not significantly higher on buses (mean(SD) = 849(645) ng/m3) than cars (650(689) ng/m3) (p-value = 0.199). For UFP, levels were significantly higher for bus commutes (9393(6923) pts/cm3) than those of private vehicle (4234(6446) pts/cm3) (p-value = 0.045). Our findings suggest that bus commuters may experience higher exposure to UFP relative to private vehicle commuters. The higher UFP exposure may be accounted by the fact that city buses can have a higher air exchange rate due to the constant opening of doors.  As well, buses are mainly diesel vehicles, which are a strong source of UFP.  

scholarly journals Visualization Strategies for Regression Estimates with Randomization Inference

2019 ◽  
Author(s):  
Marshall A. Taylor
Keyword(s):  
Confidence Interval ◽  
Confidence Intervals ◽  
Regression Models ◽  
Statistical Significance ◽  
Permutation Tests ◽  
P Value ◽  
P Values ◽  
Alpha Level ◽  
Significance Levels ◽  
Nonprobability Sample

Coefficient plots are a popular tool for visualizing regression estimates. The appeal of these plots is that they visualize confidence intervals around the estimates and generally center the plot around zero, meaning that any estimate that crosses zero is statistically non-significant at at least the alpha-level around which the confidence intervals are constructed. For models with statistical significance levels determined via randomization models of inference and for which there is no standard error or confidence intervals for the estimate itself, these plots appear less useful. In this paper, I illustrate a variant of the coefficient plot for regression models with p-values constructed using permutation tests. These visualizations plot each estimate's p-value and its associated confidence interval in relation to a specified alpha-level. These plots can help the analyst interpret and report both the statistical and substantive significance of their models. Illustrations are provided using a nonprobability sample of activists and participants at a 1962 anti-Communism school.

scholarly journals Visualization strategies for regression estimates with randomization inference

2020 ◽  
Vol 20 (2) ◽  
pp. 309-335
Author(s):  
Marshall A. Taylor
Keyword(s):  
Confidence Interval ◽  
Confidence Intervals ◽  
Regression Models ◽  
Statistical Significance ◽  
Permutation Tests ◽  
P Value ◽  
P Values ◽  
Alpha Level ◽  
Significance Levels ◽  
Nonprobability Sample

Coefficient plots are a popular tool for visualizing regression estimates. The appeal of these plots is that they visualize confidence intervals around the estimates and generally center the plot around zero, meaning that any estimate that crosses zero is statistically nonsignificant at least at the alpha level around which the confidence intervals are constructed. For models with statistical significance levels determined via randomization models of inference and for which there is no standard error or confidence intervals for the estimate itself, these plots appear less useful. In this article, I illustrate a variant of the coefficient plot for regression models with p-values constructed using permutation tests. These visualizations plot each estimate’s p-value and its associated confidence interval in relation to a specified alpha level. These plots can help the analyst interpret and report the statistical and substantive significances of their models. I illustrate using a nonprobability sample of activists and participants at a 1962 anticommunism school.

scholarly journals 249. A metabolomic study of patients with A. baumannii bacteremia

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S123-S124
Author(s):  
Hsin-Yun Sun ◽  
Aristine Cheng ◽  
Yu-Chung Chuang ◽  
San-Yuan Wang ◽  
Ching-Hua Kuo ◽  
...  
Keyword(s):  
Logistic Regression ◽  
Patient Survival ◽  
Statistical Significance ◽  
Sebacic Acid ◽  
Partial Least Square ◽  
Least Square ◽  
P Value ◽  
Healthcare Associated Infection ◽  
Box Plots ◽  
Blood Specimens

Abstract Background A. baumannii has become an emerging pathogen of healthcare-associated infection with significant mortality. The present study aimed to identify specific biomarkers to predict patient survival of A. baumannii bacteremia by metabolomics. Methods From July 2011 to November 2014, a total of 60 patients with A. baumannii bacteremia and available blood samples within 4 days of the onset (Day 0) of bacteremia were included for analysis. They were categorized into two groups depending on their survival at Day 14. Metabolomic profiles of the blood specimens collected at Day 0–4 of survival and death groups were compared to identify specific biomarkers to predict patient survival at Day 14. The patients were divided in the training (n=40) and validation (n=20) sets, and the logistic regression-based receiver-operation characteristic (ROC) was used to find the potential markers. Results The Day 14 mortality of the included patients was 20.0% (12/60). The partial least square-discriminate analysis (PLS-DA) scores plot separated the survival and death groups (Figure 1). Thirteen metabolites, L-Isoleucine, Ofloxacin, P-Hydroxybenzaldehyde, Hippurate, Indolelactic acid, Kynurenate, N-Acetyl-L-alanine, Sebacic acid, N-Acetylaspartylglutamic acid, Hematoporphyrin IX, and Urocanic acid reached the statistical significance (p < 0.05) and the accuracies of training and validation sets were greater than 0.8 and 0.6, respectively (Figure 2 and Table 1). Moreover, the Wilcoxon rank sum test results of those metabolites reached the statistical significance (Table 1). Future 1: (A) PLS-DA scores plot for death and survival groups. (B) The loading plot of PLS-DA and the distribution of the thirty important metabolites with VIP values of >1.5. Figure 2. Box plots showing significant changes of the 13 potential markers in the level of metabolites among the death and survival groups. Table 2: Identified metabolites, p value, VIP, and the result of logistic regression. Conclusion Metabolomics had the potential to identify metabolites to predict survival in patients with A. baumannii bacteremia. Disclosures All Authors: No reported disclosures

scholarly journals Identification of best indicators of peptide-spectrum match using a permutation resampling approach

2014 ◽  
Vol 12 (05) ◽  
pp. 1440001 ◽  
Author(s):  
Malik N. Akhtar ◽  
Bruce R. Southey ◽  
Per E. Andrén ◽  
Jonathan V. Sweedler ◽  
Sandra L. Rodriguez-Zas
Keyword(s):  
Mass Spectra ◽  
Statistical Significance ◽  
Permutation Tests ◽  
Database Search ◽  
Theoretical Spectrum ◽  
P Values ◽  
Tandem Mass Spectra ◽  
Wide Range ◽  
Significance Levels ◽  
Peptide Match

Various indicators of observed-theoretical spectrum matches were compared and the resulting statistical significance was characterized using permutation resampling. Novel decoy databases built by resampling the terminal positions of peptide sequences were evaluated to identify the conditions for accurate computation of peptide match significance levels. The methodology was tested on real and manually curated tandem mass spectra from peptides across a wide range of sizes. Spectra match indicators from complementary database search programs were profiled and optimal indicators were identified. The combination of the optimal indicator and permuted decoy databases improved the calculation of the peptide match significance compared to the approaches currently implemented in the database search programs that rely on distributional assumptions. Permutation tests using p-values obtained from software-dependent matching scores and E-values outperformed permutation tests using all other indicators. The higher overlap in matches between the database search programs when using end permutation compared to existing approaches confirmed the superiority of the end permutation method to identify peptides. The combination of effective match indicators and the end permutation method is recommended for accurate detection of peptides.

SERUM PROLACTINE LEVEL IN PATIENTS OF PSORIASIS VULGARIS AND ITS CORRELATION WITH DISEASE SEVERITY: A CASE-CONTROL STUDY

2019 ◽  
Vol 3 (6) ◽  
Author(s):  
Pawan Kumar Saini ◽  
Devendra Yadav ◽  
Rozy Badyal ◽  
Suresh Jain ◽  
Arti Singh ◽  
...  
Keyword(s):  
Disease Severity ◽  
Prolactin Level ◽  
Case Control Study ◽  
Statistical Significance ◽  
Case Control ◽  
Serum Prolactin ◽  
P Value ◽  
Serum Prolactin Level ◽  
R Value ◽  
Control Study

Background: Psoriasis is an autoimmune chronic inflammatory disorder affecting the skin mediated by T-lymphocytes resulting in production of cytokines which cause hyperproliferation of keratinocytes.  Several factors and hormones like Prolactin have an action similar to these cytokines in promoting the multiplication of keratinocytes and other cells like lymphocytes and epithelial cells may have a role on the etiopathogenesis of psoriasis. Aim:-The aim of study is to compare the serum Prolactin levels in patients of psoriasis with a control group. Setting and study design: This is a case-control study conducted in the department of Dermatology, Venereology and Leprosy GMC, Kota over a period of 1year from July 2017 to June 2018 Material and method: The study included 100 cases of psoriasis (60 males and 40 females) and 100 controls similar for age and sex. Serum Prolactin levels were measured by ECLIA and results were obtained. Statistical analysis: Mean and standard deviation were calculated for each variable. Statistical significance of the results was analyzed using correlation analysis (Pearson correlation coefficient) and independent samples t-test. Statistical significance was assumed at p value<0.05. Result: Serum Prolactin level was significantly higher in cases of psoriasis compared to controls (p-value <0.001). PASI score and serum Prolactin levels were found to have a positive correlation (r value = 0.337; p-value: 0.001). No significant  correlation was found between serum levels of Prolactin and duration of disease r value= -0.034, P value =0.733). Serum Prolactin level was higher in male patients compared to females patients. Conclusion:- High serum Prolactin may be a biological marker of disease severity in psoriasis and may have a role in the pathogenesis of psoriasis. Further studies with large sample size are required to confirm this hypothesis.

The Analysis Of Service Quality Using Importance Performance Analysis For Mrt Jakarta

2020 ◽  
Vol 18 (3) ◽  
pp. 85
Author(s):  
Rina Nur Chasanah ◽  
Andreas Wijaya
Keyword(s):  
Air Pollution ◽  
Performance Analysis ◽  
Service Quality ◽  
Public Transportation ◽  
Traffic Congestion ◽  
Fossil Fuels ◽  
Service Level ◽  
Public Infrastructure ◽  
Five Dimension ◽  
Quality Theory

Public infrastructure and congestion issues become salient problems in Indonesia. According to INRIX Global Traffic Scoreboard (2018): Jakarta was ranked as twelfth worst in the world. Air quality also becoming another issues that derived from traffic congestion causing air pollution. To mitigate this issue, government has been established MRT Jakarta in 2019. This study aims to evaluate and improving service level of Moda Raya Terpadu (MRT) in order to encourage more people using public transportation, moreover altering people using public transportation would reduce the amount of fossil fuels and reducing bad air pollution for a better climate. Methodolgy of the research using service quality theory with five dimension from Parasuraman et. al, and extended in Importance Performance Analysis (IPA) method. Therefore, data was distributed using questionnaire with 18 item measurement and 102 respondents was collected. As a result, tangibility, reliability, and responsiveness dimension had been classified in quadrant one, followed assurance dimension in quadrant two, however empathy dimension had been measured in quadrant four and indicates to be improved.

Awareness of radiation doses and risks among radiology residents, fellows, specialists, consultants and technologists in Jeddah, Saudi Arabia: Cross-Sectional Study. (Preprint)

2019 ◽  
Author(s):  
Bashayer Hassan Shuaib ◽  
Rahaf Hisham Niazi ◽  
Ahmed Haitham Abduljabbar ◽  
Mohammed Abdulraheem Wazzan
Keyword(s):  
Interventional Radiology ◽  
Ionizing Radiation ◽  
Statistical Significance ◽  
Knowledge Score ◽  
P Value ◽  
Radiation Doses ◽  
Cross Sectional ◽  
The Right ◽  
Interventional Radiology Procedures ◽  
Radiology Staff

BACKGROUND Radiology now plays a major role to diagnose, monitoring, and management of several diseases; numerous diagnostic and interventional radiology procedures involve exposure to ionizing radiation. Radiology now plays a major role to diagnose, monitoring, and management of several diseases; numerous diagnostic and interventional radiology procedures involve exposure to ionizing radiation. OBJECTIVE This study aimed to discover and compare the awareness level of radiation doses, protection issues, and risks among radiology staff in Jeddah hospitals. METHODS A cross-sectional survey containing 25 questions on personal information and various aspects of radiation exposure doses and risks was designed using an online survey tool and the link was emailed to all radiology staff in eight tertiary hospitals in Jeddah. The authors were excluded from the study. A P-value of < .05 was used to identify statistical significance. All analyses were performed using SPSS, version 21. RESULTS Out of 156 participants the majority 151 (96.8%) had poor knowledge score, where the mean scores were 2.4±1.3 for doses knowledge, 2.1±1.1for cancer risks knowledge, 2.3±0.6 for general information, and 6.7±1.9 for the total score. Only 34.6% of the participants were aware of the dosage of a single-view chest x-ray, and 9.0% chose the right answer for the approximate effective dose received by a patient in a two-view. 42.9% were able to know the correct dose of CT abdomen single phase. There is a significant underestimation of cancer risk of CT studies especially for CT abdomen where only 23.7% knew the right risk. A p-value of <0.05 was used to identify statistical significance. No significant difference of knowledge score was detected regarding gender (P =.2) or work position (P=.66). CONCLUSIONS Our survey results show considerable inadequate knowledge in all groups without exception. We recommended a conscientious effort to deliver more solid education and obtain more knowledge in these matters and providing periodic training courses to teach how to minimize the dose of radiation and to avoid risk related. CLINICALTRIAL not applicable

scholarly journals Can diffusion and T2 star-weighted magnetic resonance imaging aid in the diagnosis of ectopic endometrium?

2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Mariam Raafat ◽  
Soha H. Talaat ◽  
Salma M. Abdelghaffar ◽  
Engy A. Ali
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Statistical Significance ◽  
P Value ◽  
Large Sample Size ◽  
Resonance Imaging ◽  
Conventional Mri ◽  
Patient Will ◽  
Magnetic Resonance Imaging Mri ◽  
Ectopic Endometrium

Abstract Background Endometriosis is a common gynecologic disorder characterized by the implantation of the endometrial tissue ectopically outside the endometrial cavity. It affects about 10% of females at the childbearing period and is estimated to be present up to 20–50% in women complaining of infertility. While laparoscopy is considered the mainstay for diagnosis, magnetic resonance imaging (MRI) is recognized as a useful tool for definitive diagnosis, pre-surgical planning, and determining whether the patient will require multi-specialty involvement. The aim of this study is to evaluate the performance of MRI with the addition of diffusion-weighted imaging (DWI) and T2 star (T2*) to conventional MRI, for the accurate assessment of ectopic endometrium. Results Endometriotic lesions that showed diffusion restriction on DWI were 80.7%, and 96.1% of the endometriotic lesions had signal voids on the T2*W sequence, whereas only 65.4% of the lesions had typical signal intensities on T1WI and T2WI. Diagnostic performance of the MRI examination was improved by the use of the diffusion sequence and better improved by the T2* sequence, compared to the conventional MR protocol sensitivity (SE) = 96.12% and specificity (SP) = 85.7% in T2*-weighted images, SE = 80.7% and SP = 71.4% in DWI, and SE = 65.4% and SP = 71.4% in conventional MRI. P value for conventional MRI was 0.1, which is of no statistical significance (p < 0.05). P value for DWI was 0.016, which is statistically significant (p < 0.05). P value for T2*WI was 0.001, which is more statistically significant (p < 0.05) and could be adequately correlated with laparoscopy. Conclusion DWI and T2* significantly increase MRI diagnostic accuracy by allowing the detection of the hemorrhagic character of the endometriotic lesions. Studies with a large sample size are needed to confirm that they can replace invasive laparoscopy for the diagnosis of endometriosis.

scholarly journals Effect of COVID-19-related lockdown on ophthalmic practice in Italy: A report from 39 institutional centers

2021 ◽  
pp. 112067212110024
Author(s):  
Roberto dell’Omo ◽  
Mariaelena Filippelli ◽  
Gianni Virgili ◽  
Francesco Bandello ◽  
Giuseppe Querques ◽  
...  
Keyword(s):  
Quantitative Analysis ◽  
Retinal Detachment ◽  
Retrospective Analysis ◽  
Surgical Procedures ◽  
Public Transportation ◽  
Rhegmatogenous Retinal Detachment ◽  
Intravitreal Injections ◽  
P Value ◽  
Academic Hospitals ◽  
Rate Ratios

Background/objectives: To compare the number of eye surgical procedures performed in Italy in the 2 months following the beginning of lockdown (study period) because of COVID-19 epidemic with those performed in the two earlier months of the same year (intra-year control) and in the period of 2019 corresponding to the lockdown (inter-year control). Methods: Retrospective analysis of surgical procedures carried out at 39 Academic hospitals. A distinction was made between elective and urgent procedures. Intravitreal injections were also considered. Percentages for all surgical procedures and incidence rate ratios (IRR) for rhegmatogenous retinal detachment (RRD) events were calculated. A p value <0.05 was considered significant. Results: A total of 20,886 versus 55,259 and 56,640 patients underwent surgery during the lockdown versus intra-and inter-year control periods, respectively. During the lockdown, only 70% of patients for whom an operation/intravitreal injection was recommended, finally underwent surgery; the remaining patients did not attend because afraid of getting infected at the hospital (23%), taking public transportation (6.5%), or unavailable swabs (0.5%). Elective surgeries were reduced by 96.2% and 96.4%, urgent surgeries by 49.7% and 50.2%, and intravitreal injections by 48.5% and 48.6% in the lockdown period in comparison to intra-year and inter-year control periods, respectively. IRRs for RRDs during lockdown dropped significantly in comparison with intra- and inter-year control periods (CI: 0.65–0.80 and 0.61–0.75, respectively, p < 0.001 for both). Conclusion: This study provides a quantitative analysis of the reduction of eye surgical procedures performed in Italy because of the COVID-19 epidemic.

scholarly journals COVID-19 and Its Symptoms’ Panoply: A Case-Control Study of 919 Suspected Cases in Locked-Down Ovar, Portugal

2021 ◽  
pp. 1-8
Author(s):  
Regina Sá ◽  
Tiago Pinho-Bandeira ◽  
Guilherme Queiroz ◽  
Joana Matos ◽  
João Duarte Ferreira ◽  
...  
Keyword(s):  
Large Scale ◽  
Case Control Study ◽  
Statistical Significance ◽  
Case Control ◽  
Case Definition ◽  
Suspected Case ◽  
Risk Characteristics ◽  
Increased Risk ◽  
Wide Range ◽  
Control Study

<b><i>Background:</i></b> Ovar was the first Portuguese municipality to declare active community transmission of SARS-CoV-2, with total lockdown decreed on March 17, 2020. This context provided conditions for a large-scale testing strategy, allowing a referral system considering other symptoms besides the ones that were part of the case definition (fever, cough, and dyspnea). This study aims to identify other symptoms associated with COVID-19 since it may clarify the pre-test probability of the occurrence of the disease. <b><i>Methods:</i></b> This case-control study uses primary care registers between March 29 and May 10, 2020 in Ovar municipality. Pre-test clinical and exposure-risk characteristics, reported by physicians, were collected through a form, and linked with their laboratory result. <b><i>Results:</i></b> The study population included a total of 919 patients, of whom 226 (24.6%) were COVID-19 cases and 693 were negative for SARS-CoV-2. Only 27.1% of the patients reporting contact with a confirmed or suspected case tested positive. In the multivariate analysis, statistical significance was obtained for headaches (OR 0.558), odynophagia (OR 0.273), anosmia (OR 2.360), and other symptoms (OR 2.157). The interaction of anosmia and odynophagia appeared as possibly relevant with a borderline statistically significant OR of 3.375. <b><i>Conclusion:</i></b> COVID-19 has a wide range of symptoms. Of the myriad described, the present study highlights anosmia itself and calls for additional studies on the interaction between anosmia and odynophagia. Headaches and odynophagia by themselves are not associated with an increased risk for the disease. These findings may help clinicians in deciding when to test, especially when other diseases with similar symptoms are more prevalent, namely in winter.

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