Integrating Data Collection Optimization into Pavement Management Systems

This paper describes a method for using location data to optimize the routing of pavement data collection vehicles. In much of the developed world, pavement testing is performed on a regular basis; the pavement testing data, in turn, serves as input to Pavement Management Systems. Currently, in the United States of America, state departments of transportation plan this data collection work by providing the list of roads that must be tested and then leave the routing of the vehicles to the equipment operators who typically execute the work in an ad hoc manner. This study presents the processes required to code the list of roads for testing, select appropriate hotels in the region of testing, and apply a Traveling Salesman Problem with Hotel Stops model to derive a route. Applying the processes to a case study shows significant cost savings associated with this method of roadway testing, as opposed to the current ad hoc methods

Hydrogen-Poor Disks in Compact X-Ray Binaries

We show that accretion disks in several compact X-ray binaries with hydrogen-depleted donors are likely subject to a thermal ionization instability, unless they are strongly irradiated. These disks are particularly interesting in that their MHD-turbulent properties in the neutral phase may be quite different from those of standard, hydrogen-rich disks.Comment: 10 pages, accepted for publication in ApJ

Effects of intradialytic aerobic exercise on hemodialysis patients: a systematic review and meta-analysis

© 2019, The Author(s). Objective: Intradialytic exercise (IDE) is not yet a routine practice for hemodialysis patients, the lack of guidelines supporting it being a major reason. This systematic review and meta-analysis of aerobic IDE interventions examined the efficacy of IDE regarding quality of life (QOL), serum phosphorus, dialysis efficiency, inflammatory status, vitamin D3, parathyroid hormone, intake of phosphate binders, mortality and hospitalization rate. Methods: Pubmed, Medline (Ovid), Embase (Ovid), Cochrane, and Cinahl (EBSCO) databases were searched to retrieve studies up to June 12, 2018. A manual reference search was also performed. Studies were included if they evaluated (a) aerobic IDE effect on at least one of our study parameters, (b) adult hemodialysis patients, (c) patients for \u3e 1 month. Results: Twenty-two studies were retrieved (706 participants), of which 12 were eligible for meta-analysis. Aerobic IDE had a significant positive effect on the QOL physical component score (QOL-PSC) and on mental component score (QOL-MCS) of SF36, but not on serum phosphorus or Kt/V. Conclusions: IDE incorporation into clinical practice has a significant positive effect on QOL-PSC and QOL-MCS. In the reviewed studies, IDE did not result in any health hazard in hemodialysis patients. Nevertheless, future research should assess the long-term effectiveness and safety of IDE. The limitations of this review include the lack of quality analysis of the studies, the limited number of studies that could be included in the meta-analysis, the diversity in the exercise intensity, duration and modality, and the limited data for several outcomes. Prospero registration ID: CRD42016052062

Unusual case of life threatening subcutaneous hemorrhage in a blunt trauma patient

AbstractIntroductionHemorrhage is the most common cause of shock in injured patients. Bleeding into the subcutaneous plane is underestimated cause of hypovolemic shock.Presentation of caseUnrestrained male driver involved in a rollover car crash. On examination, his pulse rate was 144bpm, blood pressure 80/30mmHg, and GCS was 7/15. His right pupil was dilated but reactive. Back examination revealed severe contusion with friction burns and lacerations. A Focused Assessment Sonography for Trauma (FAST) was performed. No free intraperitoneal fluid was detected. CT scan of the brain has shown right temporo-parietal subdural hematoma and extensive hematoma in the deep subcutaneous soft tissues of the back. Decompressive cranicotomy and evacuation of the subdural hematoma was performed. On the 4th postoperative day, three liters of dark brown altered blood was drained from the subcutaneous plane.DiscussionThe patient developed severe hypovolemic shock and our aim was to identify and control the source of bleeding during the resuscitation. The source of bleeding was not obvious. Severe shearing force in blunt trauma causes separation between the loose subcutaneous tissues and the underlying relatively immobile deep fascia. This is known as post-traumatic closed degloving injury. To our knowledge this is the first reported case in the English Literature with severe subcutaneous hemorrhage in blunt trauma patients without any previous medical disease.ConclusionBleeding into the subcutaneous plane in closed degloving injury can cause severe hypovolemic shock. It is important for the clinicians managing trauma patients to be aware this serious injury

Sight Distance Standards Based On Observational Data Risk Evaluation Of Passing

The paper presents an application of a reliability analysis for evaluating the risk associated with passing sight distance (PSD) standards in terms of the expected probability of noncompliance. Calculation of PSD is required to determine where drivers can safely execute passing maneuvers. Traditional PSD standards are based on deterministic, theoretical models, which are calibrated with conservative percentile values for uncertain design inputs to account for uncertainty. The PSD standards do not provide information about the risk of deviation from them. Reliability analysis is a technique that is based on limit state design and that accounts for the propagation of variability from input random parameters to the design outputs. A total of 1,098 passing maneuvers were observed on several two-lane highways in Spain; two data collection methodologies were used: external observations and an instrumented vehicle. The most significant factors affecting PSD were impeding-vehicle speed, passing-vehicle acceleration, and head-ways between impeding and passing vehicles. A uniform acceleration model described the passing-vehicle trajectory. The characterized input parameters and the passing model were used to perform a reliability analysis. The results showed the probability of noncompliance in different scenarios, defined as the proportion of cases in which the required PSD would exceed the available sight distance. American and Spanish PSD standards were evaluated. Geometric design standards presented a probability of noncompliance of about 0.15, whereas some marking standards had a probability of noncompliance exceeding 0.85. These standards may be associated with higher risk levels if they are followed by drivers. As well, PSD risk levels were not consistent for different design speeds, since they underestimated operating speed at some locationsThis paper was developed as a result of a mobility study at the University of British Columbia funded by the Erasmus Mundus Program of the European Commission under the Transatlantic Partnership for Excellence in Engineering project. The authors thank the Spanish Ministry of Economy and Competitiveness, which subsidized the research project, and the Spanish Directorate General of Traffic, Spanish Ministry of Public Works, Valencia Regional Department of Transport, and Valencia province road department for their collaboration during the field study.Llorca Garcia, C.; Moreno Chou, AT.; Sayed, T.; García García, A. (2014). Sight Distance Standards Based On Observational Data Risk Evaluation Of Passing. Transportation research record. 2404:18-26. doi:10.3141/2404-03S18262404Ismail, K., & Sayed, T. (2009). Risk-based framework for accommodating uncertainty in highway geometric design. Canadian Journal of Civil Engineering, 36(5), 743-753. doi:10.1139/l08-146Ismail, K., & Sayed, T. (2010). Risk-Based Highway Design. Transportation Research Record: Journal of the Transportation Research Board, 2195(1), 3-13. doi:10.3141/2195-01Richl, L., & Sayed, T. (2006). Evaluating the Safety Risk of Narrow Medians Using Reliability Analysis. Journal of Transportation Engineering, 132(5), 366-375. doi:10.1061/(asce)0733-947x(2006)132:5(366)Harwood, D. W., Gilmore, D. K., & Richard, K. R. (2010). Criteria for Passing Sight Distance for Roadway Design and Marking. Transportation Research Record: Journal of the Transportation Research Board, 2195(1), 36-46. doi:10.3141/2195-05Wang, Y., & Cartmell, M. P. (1998). New Model for Passing Sight Distance on Two-Lane Highways. Journal of Transportation Engineering, 124(6), 536-545. doi:10.1061/(asce)0733-947x(1998)124:6(536)Polus, A., Livneh, M., & Frischer, B. (2000). Evaluation of the Passing Process on Two-Lane Rural Highways. Transportation Research Record: Journal of the Transportation Research Board, 1701(1), 53-60. doi:10.3141/1701-07Llorca, C., & García, A. (2011). Evaluation of Passing Process on Two-Lane Rural Highways in Spain with New Methodology Based on Video Data. Transportation Research Record: Journal of the Transportation Research Board, 2262(1), 42-51. doi:10.3141/2262-05Carlson, P., Miles, J., & Johnson, P. (2006). Daytime High-Speed Passing Maneuvers Observed on Rural Two-Lane, Two-Way Highway: Findings and Implications. Transportation Research Record: Journal of the Transportation Research Board, 1961, 9-15. doi:10.3141/1961-02Llorca, C., Moreno, A. T., García, A., & Pérez-Zuriaga, A. M. (2013). Daytime and Nighttime Passing Maneuvers on a Two-Lane Rural Road in Spain. Transportation Research Record: Journal of the Transportation Research Board, 2358(1), 3-11. doi:10.3141/2358-01Easa, S. M. (1993). Reliability‐Based Design of Intergreen Interval at Traffic Signals. Journal of Transportation Engineering, 119(2), 255-271. doi:10.1061/(asce)0733-947x(1993)119:2(255)Selvanathan, E. A., & Selvanathan, S. (1994). The demand for transport and communication in the United Kingdom and Australia. Transportation Research Part B: Methodological, 28(1), 1-9. doi:10.1016/0191-2615(94)90027-2Easa, S. M. (2000). Reliability Approach to Intersection Sight Distance Design. Transportation Research Record: Journal of the Transportation Research Board, 1701(1), 42-52. doi:10.3141/1701-06Ibrahim, S. E.-B., & Sayed, T. (2011). Developing safety performance functions incorporating reliability-based risk measures. Accident Analysis & Prevention, 43(6), 2153-2159. doi:10.1016/j.aap.2011.06.006Khoury, J. E., & Hobeika, A. G. (2007). Assessing the Risk in the Design of Passing Sight Distances. Journal of Transportation Engineering, 133(6), 370-377. doi:10.1061/(asce)0733-947x(2007)133:6(370)Khoury, J. E., & Hobeika, A. G. (2012). Integrated Stochastic Approach for Risk and Service Estimation: Passing Sight Distance Application. Journal of Transportation Engineering, 138(5), 571-579. doi:10.1061/(asce)te.1943-5436.0000366Kim, S., & Choi, J. (2013). Effects of preceding geometric conditions on operating speed consistency of multilane highways. Canadian Journal of Civil Engineering, 40(6), 528-536. doi:10.1139/cjce-2012-005

Dietary Exposure and Risk Assessment of Mycotoxins in Thyme and Thyme-Based Products Marketed in Lebanon

This study aimed at evaluating the incidence of aflatoxin B1 (AFB1) and ochratoxin A (OTA) in thyme and thyme-based products, related dietary exposure, and cancer risk for regular and high consumption. A total of 160 samples were collected, and 32 composite samples were analyzed. AFB1 and OTA were respectively found in 84% (27/32) and 38% (12/32) of the samples. AFB1 exceeded the limits in 41% (13/32) and 25% (8/32) of the samples according to the Lebanese and European standards, respectively. OTA was unacceptable in only 6% (2/32) and 3% (1/32) of the samples according to the Lebanese and European standards, respectively. AFB1 and OTA daily exposure was shown to be 4.270 and 1.345 ng/kg bw/day, respectively. AFB1 was shown to be associated with 0.41 and 0.35 additional cancer cases per 100,000 persons per year for regular consumption, respectively; while for high consumption, an increase of 0.911 and 0.639 cancer cases per 100,000 person per year was noted, respectively. The margin of exposure (MOE) for OTA was >10,000 for the non-neoplastic effect and >200 for the neoplastic effect, representing no toxicological concerns for consumers

Stability and Evolution of Supernova Fallback Disks

We show that thin accretion disks made of Carbon or Oxygen are subject to the same thermal ionization instability as Hydrogen and Helium disks. We argue that the instability applies to disks of any metal content. The relevance of the instability to supernova fallback disks probably means that their power-law evolution breaks down when they first become neutral. We construct simple analytical models for the viscous evolution of fallback disks to show that it is possible for these disks to become neutral when they are still young (ages of a few 10^3 to 10^4 years), compact in size (a few 10^9 cm to 10^11 cm) and generally accreting at sub-Eddington rates (Mdot ~ a few 10^14 - 10^18 g/s). Based on recent results on the nature of viscosity in the disks of close binaries, we argue that this time may also correspond to the end of the disk activity period. Indeed, in the absence of a significant source of viscosity in the neutral phase, the entire disk will likely turn to dust and become passive. We discuss various applications of the evolutionary model, including anomalous X-ray pulsars and young radio pulsars. Our analysis indicates that metal-rich fallback disks around newly-born neutron stars and black holes become neutral generally inside the tidal truncation radius (Roche limit) for planets, at \~10^11 cm. Consequently, the efficiency of the planetary formation process in this context will mostly depend on the ability of the resulting disk of rocks to spread via collisions beyond the Roche limit. It appears easier for the merger product of a doubly degenerate binary, whether it is a massive white dwarf or a neutron star, to harbor planets because it can spread beyond the Roche limit before becoming neutral.[Abridged]Comment: 34 pages, 2 figures, accepted for publication in Ap

Fibrin regulates neutrophil migration in response to interleukin 8, leukotriene B4, tumor necrosis factor, and formyl-methionyl-leucyl-phenylalanine

We have examined the capacity of four different chemoattractants/cytokines to promote directed migration of polymorphonuclear leukocytes (PMN) through three-dimensional gels composed of extracellular matrix proteins. About 20% of PMN migrated through fibrin gels and plasma clots in response to a gradient of interleukin 8 (IL-8) or leukotriene B4 (LTB4). In contrast, < 0.3% of PMN migrated through fibrin gels in response to a gradient of tumor necrosis factor alpha (TNF) or formyl-methionyl-leucyl-phenylalanine (FMLP). All four chemoattractants stimulated PMN to migrate through gels composed of collagen IV or of basement membrane proteins (Matrigel), or through filters to which fibronectin or fibrinogen had been adsorbed. PMN stimulated with TNF or FMLP adhered and formed zones of close apposition to fibrin, as measured by the exclusion of a 10-kD rhodamine-polyethylene glycol probe from the contact zones between PMN and the underlying fibrin gel. By this measure, IL-8- or LTB4-treated PMN adhered loosely to fibrin, since 10 kD rhodamine-polyethylene glycol permeated into the contact zones between these cells and the underlying fibrin gel. PMN stimulated with FMLP and IL-8, or FMLP and LTB4, exhibited very little migration through fibrin gels, and three times as many of these cells excluded 10 kD rhodamine-polyethylene glycol from their zones of contact with fibrin as PMN stimulated with IL-8 or LTB4 alone. These results show that PMN chemotaxis is regulated by both the nature of the chemoattractant and the composition of the extracellular matrix; they suggest that certain combinations of chemoattractants and matrix proteins may limit leukocyte movements and promote their localization in specific tissues in vivo