Reducing the risk of abandonment of assistive technologies for people with autism

This paper reports on an investigation that found that conventional techniques for including users in technology design are likely to fail if the user has autism. The heterogeneity of autistic symptomatology across cognitive, social, behavioural and communication domains suggests a 'single user' environment, while rendering typical design interaction techniques meaningless, making the need for assistive technologies great, and the risk of abandonment high. This complex problem of urgency and constraint was addressed through a Delphi study with a panel of psychologists critiquing design activities for people with autism. The major finding is that while each of the activities may work if modified, all require that the designer is well acquainted with autism in general and has a close working relationship based on trust with the individual user. If these requirements are met, there is no reason that the abandonment rate cannot be reduced.

Active-site properties of Phrixotrix railroad worm green and red bioluminescence-eliciting luciferases

The luciferases of the railroad worm Phrixotrix (Coleoptera: Phengodidae) are the only beetle luciferases that naturally produce true red bioluminescence. Previously, we cloned the green- (PxGR) and red-emitting (PxRE) luciferases of railroad worms Phrixotrix viviani and P. hirtus[OLE1]. These luciferases were expressed and purified, and their active-site properties were determined. The red-emitting PxRE luciferase displays flash-like kinetics, whereas PxGR luciferase displays slow-type kinetics. The substrate affinities and catalytic efficiency of PxRE luciferase are also higher than those of PxGR luciferase. Fluorescence studies with 8-anilino-1-naphthalene sulfonic acid and 6-p-toluidino-2-naphthalene sulfonic acid showed that the PxRE luciferase luciferin-binding site is more polar than that of PxGR luciferase, and it is sensitive to guanidine. Alutagenesis and modelling studies suggest that several invariant residues in the putative luciferin-binding site of PxRE luciferase cannot interact with excited oxyluciferin. These results suggest that one portion of the luciferin-binding site of the red-emitting luciferase is tighter than that of PxGR luciferase, whereas the other portion could be more open and polar.

Molecular insights on the evolution of the lateral and head lantern luciferases and bioluminescence colors in Mastinocerini railroad-worms (Coleoptera: Phengodidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The influence of the region between residues 220 and 344 and beyond in Phrixotrix railroad worm luciferases green and red bioluminescence

To find the regions having a major influence on the bioluminescence spectra of railroad worm luciferases, we constructed new chimeric luciferases switching the fragments from residues 1-219 and from 220-545 between Phrixotrix viviani (PxvGR; λmax = 548 nm) green light-emitting luciferase and Phrixothrix hirtus (PxhRE; λmax = 623 nm) red light-emitting luciferases. The emission spectrum (λmax = 571 nm) and KM for luciferin in the chimera PxRE220GR (1-219, PxhRE; 220-545, PxvGR) suggested that the region above residue 220 of PxvGR had a major effect on the active site. However, switching the sequence between the residues 226-344 from PxvGR luciferase into PxhRE (PxREGRRE) luciferase resulted in red light emission (λmax = 603 nm), indicating that the region 220-344 by itself does not determine the emission spectrum. Furthermore, the sequence before residue 220 of the green-emitting luciferase is incompatible for light emission with the sequence above residue 220 of PxhRE. These results suggest that the fragments before and after residue 220, which correspond to distinct subdomains, may fold differently in the green- and red-emitting luciferases, affecting the active site conformation.

Method for estimating railroad track settlements due to dynamic traffic loads

This paper is the result of real-scale physical modeling study designed to simulate the load-deformation characteristics of railroad foundation systems that include the railroad ties, the ballast, and the sub-base layers of a railroad embankment. The study presents comparisons of the application of dynamic loads of 100kN on the rails, and the resulting deformations during a 500,000 cycle testing period for three rail support systems; wood, concrete and steel. The results show that the deformation curve has an exponential shape, with the larger portion of the deformation occurring during the first 50,000 load cycles followed by a tendency to stabilize between 100,000 to 500,000 cycles. These results indicate that the critical phase of deformations of a new railroad is within the first 50,000 cycles of loading, and after that, it slowly attenuates as it approaches a stable value. The paper also presents empirically derived formulations for the estimation of the deformations of the rail supports as a result of rail traffic.

Geotechnical and structural behavior of the railroad track in large-scale apparatus

This paper analyses the static and dynamic behavior of the railroad track model in laboratory. Measurements of stresses and strains on a large-scale railroad track apparatus were studied. The model includes: compacted soil, representing the final layers of platform, ballast layer, and ties (steel, wooden, and pre-stressed concrete). The soil and soil ballast interface were instrumented with pneumatic stress gauge. Settlement measurement device were positioned at the same levels as the load cells. Loads were applied by hydraulic actuators, statically and dynamically. After the prescribed number of load cycles, in pre-determined intervals, stresses and strains were measured. Observations indicate that stress and strain distributions, transmitted by wooden or steel ties, behave similarly. A more favorable behavior was observed with pre-stressed concrete mono block ties. Non-linear response was observed after a threshold numbers of cycles were surpassed, showing that the strain modulus increases with the numbers of cycles. © 2009 IOS Press.

Going through the labyrinth: the political economy of Argentina’s abandonment of the gold standard (1929-1933)

This article is the short but crucial history of four years of transition in a monetary and exchange-rate regime that culminated in 1933 with the final abandonment of the gold standard in Argentina. That process involved decisions made at critical junctures at which the government authorities had little time to deliberate and against which they had no analytical arsenal, no technical certainties and few political convictions. The objective of this study is to analyse those “decisions” at seven milestone moments, from the external shock of 1929 to the submission to Congress of a bill for the creation of the central bank and a currency control regime characterized by multiple exchange rates. The new regime that this reordering of the Argentine economy implied would remain in place, in one form or another, for at least a quarter of a century.

Measurement, Simulation, and Analysis of the Mechanical Response of Railroad Track

Increased railroad traffic volumes, speeds, and axle loads have created a need to better measure track quality. Previous research has indicated that the vertical track deflection provides a meaningful indicator of track integrity. The measured deflection can be related to the bending stresses in the rail as well as characterize the mechanical response of the track. This investigation summarizes the simulation, analysis and development of a measurement system at the University of Nebraska (UNL) to measure vertical track deflection in real-time from a car moving at revenue speeds. The UNL system operates continuously over long distances and in revenue service. Using a camera and two line lasers, the system establishes three points of the rail shape beneath the loaded wheels and over a distance of 10 ft. The resulting rail shape can then be related to the actual bending stress in the rail and estimate the track support through beam theory. Finite element simulations are used to characterize the track response as related to the UNL measurement system. The results of field tests using bondable resistance strain gages illustrate the system’s capability of approximating the actual rail bending stresses under load.

Fostering Children and Adolescents in Situations of Abandonment, Violence and Separation

Childhood protection is undergoing several changes. Our study aimed to outline the complex network of meanings which includes adoption as well as institutional and family foster care, by combining theory, research and practice. We investigated various contexts and protagonists: judicial system, foster institutions, birth parents, foster and adoptive parents, and families and their children. Diverse data collection procedures were used: socio-demographic investigations, case-studies, follow-ups, interviews, analysis of foster institutions and legal court documents. Results pointed to "invisibility" of birth family, frequent child (re)abuse, failures in the network of protection, meanings of "healthy family" and role of attachment concepts. Implications for social policies and social practices are discussed.

Emergency response to railroad accidents involving hazardous materials

The chemical industry has to face safety problems linked to the hazards of chemicals and the risks posed by the plants where they are handled. However, their transport may cause significant risk values too: it’s not totally possible to avoid the occurrence of accidents. This work is focused on the emergency response to railway accidents involving hazardous materials, that is what has to be done once they happen to limit their consequences. A first effort has been devoted to understand the role given to this theme within legislations: it has been found out that often it’s not even taken into account. Exceptionally a few countries adopt guidelines suggesting how to plan the response, who is appointed to intervene and which actions should be taken first. An investigation has been made to define the tools available for the responders, with attention on the availability of chemical-specific safety distances. It has emerged that the ERG book adopted by some American countries has suggestions and the Belgian legislation too establishes criteria to evaluate these distances. An analysis has been conducted then on the most recent accidents occurred worldwide, to understand how the response was performed and which safety distances were adopted. These values were compared with the numbers reported by the ERG book and the results of two devoted software tools for consequence analysis of accidental spills scenarios. This comparison has shown that there are differences between them and that a more standardized approach is necessary. This is why further developments of the topic should focus on promoting uniform procedures for emergency response planning and on a worldwide adoption of a guidebook with suggestions about actions to reduce consequences and about safety distances, determined following finer researches. For this aim, the development of a detailed database of hazardous materials transportation accidents could be useful.

Capacity optimization of a prestressed concrete railroad tie

Today the use of concrete ties is on the rise in North America as they become an economically competitive alternative to the historical industry standard wood ties, while providing performance which exceeds its competition in terms of durability and capacity. Similarly, in response to rising energy costs, there is increased demand for efficient and sustainable transportation of people and goods. One source of such transportation is the railroad. To accommodate the increased demand, railroads are constructing new track and upgrading existing track. This update to the track system will increase its capacity while making it a more reliable means of transportation compared to other alternatives. In addition to increasing the track system capacity, railroads are considering an increase in the size of the typical freight rail car to allow larger tonnage. An increase in rail car loads will in turn affect the performance requirements of the track. Due to the increased loads heavy haul railroads are considering applying to their tracks, current designs of prestressed concrete railroad ties for heavy haul applications may be undersized. In an effort to maximize tie capacity while maintaining tie geometry, fastening systems and installation equipment, a parametric study to optimize the existing designs was completed. The optimization focused on maximizing the capacity of an existing tie design through an investigation of prestressing quantity, configuration, stress levels and other material properties. The results of the parametric optimization indicate that the capacity of an existing tie can be increased most efficiently by increasing the diameter of the prestressing and concrete strength. However, researchers also found that current design specifications and procedures do not include consideration of tie behavior beyond the current tie capacity limit of cracking to the first layer of prestressing. In addition to limiting analysis to the cracking limit, failure mechanisms such as shear in deep beams at the rail seat or pullout failure of the prestressing due to lack of development length were absent from specified design procedures, but discussed in this project.

AN ASSESSMENT OF BALLAST SOURCE'S QUALITY AND LOCATIONS WITH RESPECT TO MDOT'S UPGRADE OF THE WOLVERINE RAILROAD LINE FOR HIGH SPEED RAIL USEAGE

The Michigan Department of Transportation is evaluating upgrading their portion of the Wolverine Line between Chicago and Detroit to accommodate high speed rail. This will entail upgrading the track to allow trains to run at speeds in excess of 110 miles per hour (mph). An important component of this upgrade will be to assess the requirement for ballast material for high speed rail. In the event that the existing ballast materials do not meet specifications for higher speed train, additional ballast will be required. The purpose of this study, therefore, is to investigate the current MDOT railroad ballast quality specifications and compare them to both the national and international specifications for use on high speed rail lines. The study found that while MDOT has quality specifications for railroad ballast it does not have any for high speed rail. In addition, the American Railway Engineering and Maintenance-of-Way Association (AREMA), while also having specifications for railroad ballast, does not have specific specifications for high speed rail lines. The AREMA aggregate specifications for ballast include the following tests: (1) LA Abrasion, (2) Percent Moisture Absorption, (3) Flat and Elongated Particles, (4) Sulfate Soundness test. Internationally, some countries do require a highly standard for high speed rail such as the Los Angeles (LA) Abrasion test, which is uses a higher standard performance and the Micro Duval test, which is used to determine the maximum speed that a high speed can operate at. Since there are no existing MDOT ballast specification for high speed rail, it is assumed that aggregate ballast specifications for the Wolverine Line will use the higher international specifications. The Wolverine line, however, is located in southern Michigan is a region of sedimentary rocks which generally do not meet the existing MDOT ballast specifications. The investigation found that there were only 12 quarries in the Michigan that meet the MDOT specification. Of these 12 quarries, six were igneous or metamorphic rock quarries, while six were carbonate quarries. Of the six carbonate quarries four were locate in the Lower Peninsula and two in the Upper Peninsula. Two of the carbonate quarries were located in near proximity to the Wolverine Line, while the remaining quarries were at a significant haulage distance. In either case, the cost of haulage becomes an important consideration. In this regard, four of the quarries were located with lake terminals allowing water transportation to down state ports. The Upper Peninsula also has a significant amount of metal based mining in both igneous and metamorphic rock that generate significant amount of waste rock that could be used as a ballast material. The main drawback, however, is the distance to the Wolverine rail line. One potential source is the Cliffs Natural Resources that operates two large surface mines in the Marquette area with rail and water transportation to both Lake Superior and Lake Michigan. Both mines mine rock with a very high compressive strength far in excess of most ballast materials used in the United States and would make an excellent ballast materials. Discussions with Cliffs, however, indicated that due to environmental concerns that they would most likely not be interested in producing a ballast material. In the United States carbonate aggregates, while used for ballast, many times don't meet the ballast specifications in addition to the problem of particle degradation that can lead to fouling and cementation issues. Thus, many carbonate aggregate quarries in close proximity to railroads are not used. Since Michigan has a significant amount of carbonate quarries, the research also investigated using the dynamic properties of aggregate as a possible additional test for aggregate ballast quality. The dynamic strength of a material can be assessed using a split Hopkinson Pressure Bar (SHPB). The SHPB has been traditionally used to assess the dynamic properties of metal but over the past 20 years it is now being used to assess the dynamic properties of brittle materials such as ceramics and rock. In addition, the wear properties of metals have been related to their dynamic properties. Wear or breakdown of railroad ballast materials is one of the main problems with ballast material due to the dynamic loading generated by trains and which will be significantly higher for high speed rails. Previous research has indicated that the Port Inland quarry along Lake Michigan in the Southern Upper Peninsula has significant dynamic properties that might make it potentially useable as an aggregate for high speed rail. The dynamic strength testing conducted in this research indicate that the Port Inland limestone in fact has a dynamic strength close to igneous rocks and much higher than other carbonate rocks in the Great Lakes region. It is recommended that further research be conducted to investigate the Port Inland limestone as a high speed ballast material.

Copper Range Railroad General Freight Department Rules and Regulations

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