Development, validation, and application of School Audit Tool (SAT): An effective instrument for assessing traffic safety and operation around schools

There is a need for a reliable school audit tool with well-defined scales to convert qualitative evaluation of existing school sites into a quantitative assessment in order to help public agencies to improve schools' safety and efficiency. In this study, a new, simple, and versatile School Audit Tool (SAT) was developed and tested. SAT was formed using a 30-item checklist categorized into four domains: school site assessment, road network assessment, parking/loading assessment, and active transport assessment. The tool was applied on a sample of 22 schools. Then, categorical and item-by-item Intraclass Correlation Coefficients (ICC) were calculated to validate the tool. The results showed acceptable overall test-retest (ICC = 0.919) and inter-rater reliability (ICC = 0.843) across all items and domains. SAT's adaptable framework to assess and compare the safety and efficiency of schools is reliable, easy-to-use, and comprehensive. The tool is also effective in ranking schools and identifying items that may require upgrades or modifications. - 2019 by the authors.Acknowledgments: The publication of this article was funded by the Qatar National Library.Scopu

SYNTHESIS AND X-RAY CRYSTALLOGRAPHY OF 2,4,6-TRIMETHYL-1,4-DIHYDRO-PYRIDINE-3,5-DICARBOXYLIC ACID DIETHYL ESTER

The biologically active 2,4,6-trimethyl-1,4-dihydro-pyridine-3,5-dicarboxylic acid diethyl ester has been prepared and characterized by X-ray crystallography. The 1,4-dihydro-pyridine ring is in a flattened boat form, with atoms C3, and N1 being the bow and stern of the boat. Atoms C3 and N1 being 0.1346(12)A and 0.0970(12)A above the mean plane of the 1,4-dihydro-pyridine ring. One of the ethyl ester groups were found to be disordered in two positions at occupancies of 0.517 (19) and 0.483 (19) respectively. There are four molecules of 2,4,6-trimethyl-1,4-dihydro-pyridine-3,5-dicarboxylic acid diethyl ester, in the unit cell. Inter­molecular N—H···O hydrogen bonding inter­actions were observed in the crystal lattice which connected the molecules into chain running along b-axis

Real-time ultrasound elastography: Does it improve B-mode ultrasound characterization of solid breast lesions?

AbstractIntroductionElastography is a non-invasive medical imaging technique that detects tumors based on their stiffness (elasticity). Strain images display the relative stiffness of lesions compared with the stiffness of surrounding tissue as cancerous tumors tend to be many times stiffer than the normal tissue, which “gives” under compression. An image in which different degrees of stiffness show as different shades of light and dark is called an elastogram.PurposeTo prospectively evaluate the sensitivity and specificity of the real-time sonoelastography as compared with B-mode US for distinguishing between benign and malignant solid breast masses. The density of the glandular breast tissue was taken in consideration in addition to the Breast Imaging Reporting and Data System (BI-RADS) categories of the lesions, with biopsy results as the reference standard.MethodsA total of 216 candidate solid lesions (123 benign and 93 malignant) in 188 patients were examined with 2-dimensional ultrasonography, elastosonography and mammography (for 147 patients). The lesions were classified according to the density of the glandular breast tissue into low density group (D1) and a high density group (D2) and were categorized with the BIRADS score. Elastographic images were assigned an elasticity score of 1 to 5 (1–3, benign; 4 and 5, malignant) according to the Multi-Center Team of Study and the strain ratios of the lesions were measured. Concordance between the imaging findings and histopathologic results was documented. Statistical analysis was performed and sensitivity, specificity and positive and negative predictive values for both elastography and conventional sonography were calculated.ResultsElastography showed less sensitivity but higher specificity than conventional sonography in the differentiation of benign from malignant solid lesions: B-mode sonography had sensitivity of 85.1%, specificity of 93.9%, a positive predictive value of 92.5% and a negative predictive value of 87.8%, compared with the sensitivity of 80.1%, specificity of 97.1%, a positive predictive value of 96.8% and a negative predictive value of 82.1% for elastography. Elastography was superior to B-mode US in diagnosing solid lesions in the low density group (D1) (96.6% vs. 92.4% specificity) and less in the dense glandular tissue (97.8% vs. 95.9% specificity).ConclusionsReal-time sonoelastography is an useful technique for the characterization of benign and malignant solid lesions as it increases the diagnostic specificity comparable to B-mode ultrasound, particularly in both ACR 1 and 2, thus reducing the false-positive rate

A Strategy for Emergency Vehicle Preemption and Route Selection

Emergency vehicle preemption (EVP) aims to give right of way to emergency vehicles (EV) heading toward the incident location through a network of signalized intersections by creating a green wave en-route. The design goals of EVP systems are two folds: first, to avoid any hindrance to the passage of EV along the road and at the intersections and second, to reduce the negative impact of preemption on general traffic. The negative impact of EVP on normal traffic can be minimized by selecting appropriate preemption strategy. The EVP schemes proposed earlier aim to minimize the travel time of the EV with no or little consideration to the negative impact of EVP on the normal traffic. In this study, a joint strategy for optimal path selection and EV preemption is developed. The proposed scheme selects the optimal path for the EV before it departs from its origin and then activates the preemption on each intersection en-route at the right time to clear the intersection before the EV reaches. The proposed EVP scheme also aims to minimize the impact of EVP over normal traffic at both stages (i.e., path selection phase and preemption phase). A major advantage of the proposed method is that once the optimal path is selected, the emergency information can be disseminated to other vehicles using vehicle-to-vehicle and vehicle-to-infrastructure communication in the EV path to clear the entire route or the approaching lane. The strategy was tested using a microscopic simulation environment for a real traffic network. The findings indicated a major reduction in the travel time of the EV while minimizing the impact of preemption on the normal traffic. The proposed strategy and evaluation procedure can be helpful for corresponding agencies and practitioners to assess the impact of implementing preemption on existing or proposed arterials. - 2019, The Author(s).Open access funding provided by the Qatar National Library.Scopu

14-Bromo-12-chloro-2,16-dioxapentacyclohenicosa-3(8),10,12,14-tetraene-7,20-dione

In the title compound, C19H16BrClO4, both the fused xanthene rings and one of the cyclohexane rings adopt envelope conformations, while the other cyclohexane ring is in a chair conformation. In the crystal, molecules are linked by C-H...O hydrogen bonds, forming infinite chains running along [10-1] incorporating R22(16) ring motifs. In addition, C-H...[pi] interactions and weak [pi]-[pi] stacking interactions [centroid-centroid distance = 3.768 (3) Å] help to consolidate the packing

2,2′-[(E,E)-cis-(Cyclo­hexane-1,4-di­yl)bis­(nitrilo­methanylyl­idene)]diphenol

In the title compound, C20H22N2O2, the asymmetric unit contains two independent half-mol­ecules, which are both completed by crystallographic inversion symmetry. The cyclo­hexane rings of both mol­ecules adopt chair conformations; the N atoms are in equatorial orientations in one mol­ecule and in axial orientations in the other. Both mol­ecules feature two intra­molecular O—H⋯N hydrogen bonds, which generate S(6) rings