24 research outputs found
An Investigation of the Performance of Urban Rail Transit Systems on the Corridor Level: A Comparative Analysis in the American West
Since the 1980s, significant investments have been made in urban rail transit across the United States, particularly using light rail technology. Most of these light rail systems have been built in Sunbelt cities which no longer had legacy rail systems. As a result, they were constructed using a building blocks approach, being funded corridor by corridor. Most research, however, on urban rail performance has taken place at the system-wide level, leaving a significant gap at the level of the transit corridor. This research examined nineteen urban rail corridors in Denver, Salt Lake City, and Portland. A performance score was constructed for each corridor based upon ridership per mile, ridership growth, capital costs, and the cost of ongoing operations. These scores were then compared with a constructed profile of each corridor studied, which included aspects including but not limited to population and job density, median income, park and ride spaces, bus connections available, walkability, and headways between trains. Corridors in each city ranked high and low, with no city emerging as a clear frontrunner. Headways, population density, and percentage renter occupied housing units were found to have a statistically significant relationship with high corridor performance, largely in line with previous studies. Qualitative data gathered from this research suggest that partnerships with municipalities, communities, and businesses also played a crucial role in the development of successful urban rail corridors
Исследование процесса изомеризации подсолнечного масла
В статті представлені результати дослідження процесу ізомеризації соняшникової олії. Матеріали на основі ізомеризованих олій можуть бути використані для отримання покриттів з високими фізико-механічними та захисними властивостями.In article were presented results of the study process isomerization sunflower butter. The material got on base isomerization sunflower butter, can be used for reception covering with high physico-mechanical and protective properties
Introducing a pole concept for nodule growth in the thyroid gland: taller-than-wide shape, frequency, location and risk of malignancy of thyroid nodules in an area with iodine deficiency
Purpose : (i) To examine the criterion taller-than-wide (TTW) for the sonographic assessment of thyroid nodules in areas of iodine deficiency in terms of frequency, anatomical distribution within the thyroid gland and risk of malignancy. (ii) To develop a model for nodule growth in the thyroid gland. Methods: German multicenter study consisting of two parts. In the prospective part, thyroid nodules were sonographically measured in all three dimensions, location within the thyroid gland and contact to a protrusion-like formation (horn) in the dorsal position of thyroid gland was noted. In addition, further sonographic features such as the composition, echogenity, margins and calcifications were investigated. All nodules from the prospective part were assessed for malignancy as part of clinical routine at the decision of the treating physician adhering to institutionally based algorithms. In the retrospective part, only nodules with fine needle aspiration and/or histology were included. The risk of malignancy in TTW nodules was determined by correlating them with cyotological and histological results. Results: Prospective part: out of 441 consecutively evaluated thyroid nodules, 6 were found to be malignant (1.4%, 95% CI 0.6–2.7%). Among the 74 TTW nodules (17%), 1 was malignant (1%, 95% CI 0–4%). TTW nodules were more often located in the dorsal half of the thyroid than non-TTW nodules (factor 2.3, p = 0.01, 95% CI 2.1–2.5) and more often located in close proximity to a horn than non-TTW nodules (factor 3.0, p = 0.01, 95% CI 2.4–3.8). Retrospective part: out of 1315 histologically and/or cytologically confirmed thyroid nodules, 163 TTW nodules were retrieved and retrospectively analyzed. A TTW nodule was 1.7 times more often benign when it was dorsal (95% CI 1.1–2.5) and 2.5 times more often benign when it was associated with a horn (95% CI 1.2–5.3). The overall probability of malignancy for TTW nodules was 38% (95% CI 30–46%) in this highly preselected patient group. Conclusion: TTW nodules are common in iodine deficient areas. They are often located in the dorsal half of the thyroid gland and are frequently associated with a dorsal protrusion-like formation (horn) of the thyroid. Obviously, the shape of benign nodules follows distinct anatomical preconditions within the thyroid gland. The frequency of TTW nodules and their predominant benignity can be explained by a pole concept of goiter growth. The difference between the low malignancy risk of TTW nodules found on a prospective basis and the high risk found retrospectively may be the result of a positive preselection in the latter
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Inward and Outward FDI Country Profiles, Second Edition
This second edition contains a series of 77 standardized country profiles dealing with the inward and outward foreign direct investment (FDI) performance of 40 economies. The profiles have been peer-reviewed by a global network of experts. The publication is intended to contribute to the analysis of trends in foreign direct investment and policy issues related to them. More specifically, the individual profiles discuss FDI trends and developments (country-level developments, the corporate players); effects of the recent global crises; and the policy scene. Each profile contains a standard set of tables, including on FDI stocks and flows, sectoral and geographical FDI distributions, the largest M&As and greenfield investments, the principal foreign affiliates (for inward FDI), and the principal multinational enterprises (for outward FDI). The standardized template used to produce the profiles allows cross-country comparisons. The volume is meant to be a reference tool for anyone interested in foreign direct investment
Effect of surgical experience and spine subspecialty on the reliability of the {AO} Spine Upper Cervical Injury Classification System
OBJECTIVE
The objective of this paper was to determine the interobserver reliability and intraobserver reproducibility of the AO Spine Upper Cervical Injury Classification System based on surgeon experience (< 5 years, 5–10 years, 10–20 years, and > 20 years) and surgical subspecialty (orthopedic spine surgery, neurosurgery, and "other" surgery).
METHODS
A total of 11,601 assessments of upper cervical spine injuries were evaluated based on the AO Spine Upper Cervical Injury Classification System. Reliability and reproducibility scores were obtained twice, with a 3-week time interval. Descriptive statistics were utilized to examine the percentage of accurately classified injuries, and Pearson’s chi-square or Fisher’s exact test was used to screen for potentially relevant differences between study participants. Kappa coefficients (κ) determined the interobserver reliability and intraobserver reproducibility.
RESULTS
The intraobserver reproducibility was substantial for surgeon experience level (< 5 years: 0.74 vs 5–10 years: 0.69 vs 10–20 years: 0.69 vs > 20 years: 0.70) and surgical subspecialty (orthopedic spine: 0.71 vs neurosurgery: 0.69 vs other: 0.68). Furthermore, the interobserver reliability was substantial for all surgical experience groups on assessment 1 (< 5 years: 0.67 vs 5–10 years: 0.62 vs 10–20 years: 0.61 vs > 20 years: 0.62), and only surgeons with > 20 years of experience did not have substantial reliability on assessment 2 (< 5 years: 0.62 vs 5–10 years: 0.61 vs 10–20 years: 0.61 vs > 20 years: 0.59). Orthopedic spine surgeons and neurosurgeons had substantial intraobserver reproducibility on both assessment 1 (0.64 vs 0.63) and assessment 2 (0.62 vs 0.63), while other surgeons had moderate reliability on assessment 1 (0.43) and fair reliability on assessment 2 (0.36).
CONCLUSIONS
The international reliability and reproducibility scores for the AO Spine Upper Cervical Injury Classification System demonstrated substantial intraobserver reproducibility and interobserver reliability regardless of surgical experience and spine subspecialty. These results support the global application of this classification system
Copper, nickel, lead and zinc in the zones affected by exploitation of copper deposits in the Lower Silesia
Base metals (Cu, Zn and Pb) as the main resources of the Lower Silesian copper deposits have significantly been influenced by different enviromentalfactors. In this paper, changes in metal concentrations on the surface in relation to deeper layers of the sediments were examined. The concentration ofmetals in the whole sediment, and in selected grain fractions was studied. The contents of these metals in the soils of areas adjacent to the deposit are diverse and are in the range of: 3.0-1082.9 mg/kg Cu; 3.5-106.1 mg/kg Pb; 27.6-49.3 mg/kg Zn, and 1.33-23.0 mg/kg Ni in the old deposit district and Cu 0.91-1655.0 mg/kg Pb; 10.0-1792.0 mg/kg Zn; 3.38-1129.0 and 0.47-32.7 mg/kg Ni in the new deposit district. The increase of metal concentration in the finefractions has been observed. Moreover, the decrease in the metal content with depth was observed in all investigated profiles
An investigation of the performance of urban rail transit systems on the corridor level: A comparative analysis in the American west
Since the 1980s, significant investments have been made in urban rail transit across the United States, particularly using light rail technology. Most of these light rail systems have been built in Sunbelt cities which no longer had legacy rail systems. As a result, they were constructed using a building blocks approach, being funded corridor by corridor. Most research, however, on urban rail performance has taken place at the system-wide level, leaving a significant gap at the level of the transit corridor. This research examined nineteen urban rail corridors in Denver, Salt Lake City, and Portland. A performance score was constructed for each corridor based upon ridership per mile, ridership growth, capital costs, and the cost of ongoing operations. These scores were then compared with the geographic profile of each corridor studied. Corridors in each city ranked high and low, with no city emerging as a clear frontrunner. More centrally-located corridors in each city registered the highest performance scores, while longer corridors in more peripheral locations had lower performance scores. Headways, population density, job density, walkability, and percentage renter occupied housing units were found to have a statistically significant relationship with high corridor performance, largely in line with previous studies, though median income, bus connections, and park and ride spaces were not found to increase performance in this study
Comparative analysis of coaxial magnetocumulative generators
This paper presents the results of a computer simulation of coaxial magnetocumulative current generators (MCGs). The simulation tests were carried out for different values of the internal diameter, length and speed of the deformation of the MGP element
Comparative analysis of coaxial magnetocumulative generators
This paper presents the results of a computer simulation of coaxial magnetocumulative current generators (MCGs). The simulation tests were carried out for different values of the internal diameter, length and speed of the deformation of the MGP element