bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of Quality of Life Following Placement of Self-Expanding Plastic Stents as a Bridge to Surgery in Patients Receiving Neoadjuvant Therapy for Esophageal Cancer
Authors: Martin Robert C.G. , Cannon Robert M. , Brown Russell E. , Ellis Susan F. , Williams Sharon , Scoggins C.R. , Abbas Abbas E.
Published: February 2014

Learning Objectives

Describe the quality of life changes that can occur during neoadjuvant therapy for esophageal cancer. Explain the use of esophageal stenting during neoadjuvant therapy for esophageal cancer.

Purpose.

To determine whether self-expanding plastic stent (SEPS) placement significantly improves quality of life and maintains optimal nutrition while allowing full-dose neoadjuvant therapy (NAT) in patients with esophageal cancer.

Patients and Methods.

A prospective, dual-institution, single-arm, phase II (http://ClinicalTrials.gov: 00727376) evaluation of esophageal cancer patients undergoing NAT prior to resection. All patients had a self-expanding polymer stent placed prior to NAT. The European Organisation for Research and Treatment of Cancer QLQ-C30 and QLQ-OG25, Functional Assessment of Cancer Therapy–Anorexia, and Functional Assessment of Cancer Therapy–General surveys were administered prior to stenting, within 1 week post-stent placement, and at the completion of neoadjuvant therapy.

Results.

Fifty-two patients were enrolled; 3 (5.8%) had stent migrations requiring replacement. There were no instances of esophageal erosion or perforation. All patients received some form of neoadjuvant therapy. Thirty-six (69%) received chemoradiation; 34 (93%) of these patients received the planned dose of chemotherapy, and 27 (75%) received the full planned dose of radiotherapy. There were 16 (31%) patients receiving chemotherapy alone; 12 (74%) of patients in the chemotherapy-alone group completed the planned dose of therapy.

Conclusion.

Placement of SEPS appears to provide significant improvement in quality of life related to dysphagia and eating restriction in patients with esophageal cancer undergoing neoadjuvant therapy. Consideration of SEPS instead of percutaneous feeding tube should be initiated as a first line in dysphagia palliation and NAT nutritional support.
Capillary absorption of concrete after mechanical loading
Authors: Wang Licheng , Li Shuhong
Published: February 2014

Microcracks, which are always present in concrete, play a critical role in the durability of concrete because they provide additional pathways for aggressive agents such as chlorides to penetrate into the material. A thorough understanding of the transport properties of cracked/damaged concrete is thus essential for predicting its long-term durability. In addition, for concrete in an unsaturated state, water acts as the main medium for the ingress of chloride ions into concrete. This paper presents an experimental investigation into the capillary absorption of concrete after being subjected to compressive or tensile loading. Sorptivity is chosen as a parameter to describe the rate of water penetrating into concrete since it can characterise the tendency of cementitious materials to absorb and transmit water by the capillary mechanism. A series of water absorption experiments were conducted on concrete samples after being subjected to uniaxial compressive or tensile loading. Three load levels were considered – 70%, 80% and 90% of the corresponding compression and tension loading capacity. An improved gravimetrical test device was used to measure the cumulative water absorbed by concrete at the given time of exposure. The results show that mechanical loading, compression or tension, has an important influence on the water absorption of concrete. The rate of capillary absorption of load-damaged concrete can be up to double that of sound concrete samples for the ranges of load level studied.
What is a Principal's Quality Mark? Issues and Challenges in Leadership Progression among Primary Teachers in Jamaica
Authors: Miller Paul
Published: February 2014

Perceptions about teacher progression among Jamaica's primary school teachers should force society to stop and ask itself several questions. Are these perceptions accurate? If not, how did these perceptions emerge and what can national leaders and those in positions of authority do to ‘manage’ if not resolve these perceptions? If there is any truth to them, a different set of questions needs to be asked. How did things come to be like this? How can the perception of corruption and mistrust be minimised? What will be done differently going forward? Either way, there is a more fundamental question: Do the current perceptions among teachers mirror perceptions in other areas of the public service? The answers to these questions are not easy. The findings being reported in this article form part of a small-scale qualitative exploratory study aimed at identifying and understanding the perceptions of primary school teachers in Jamaica as regards progression to the rank of principal. The findings point to a number of perceived barriers including religious affiliation, political affiliation, interference, and social connections. This article proposes that promotion on any basis other than merit is problematic and does not promote trust, openness and transparency; nor does it build confidence in those who are part of the system, but themselves do not have such connections and/or affiliations.
Teach Me to Write; but Respec’ Meh Right: A Critical Exploration of Vernacular Accommodation in Tertiary Education for all in Trinidad and Tobago
Authors: Figuera Renée , Ferreira Leiba-Ann
Published: February 2014

Since the introduction of the Education for All policy of the Government Assistance for Tuition Expenses (GATE) in Trinidad and Tobago, more tertiary level classrooms have been furnished with mixed linguistic and academic abilities and have accommodated more non-traditional tertiary-level entrants into the educational system. The expansion of the tertiary sector has also fostered lower minimum requirements for candidates entering tertiary institutions of learning (TILs), which differ from higher institutions of learning (HILs). More inclusive strategies in English composition courses are therefore needed to manage the reality of mixed abilities and greater non-standard language use among some of these learners, as part of the educational process. Therefore, the author proposes limited vernacular accommodation as a response to sectoral diversity and as a viable strategy for more inclusive education that would match the learner characteristics and the socio-educational contexts of TILs. In support of this recommendation, evidence-based findings from a case study among 39 students at a large private university exemplify the outcomes of vernacular accommodation in relation to student performance, linguistic identity and learner confidence. These outcomes further the cause of vernacular integration policies in education towards ensuring that true inclusion is upheld in the educational process. Moreover, the participatory power balance between students and teachers in this context will provide students with greater confidence and success in the short- and long-term, and will provide teachers with the critical awareness for transacting more equitable appraisals and for resisting hegemonic teaching and learning practices. In this way, true inclusion will extend beyond the mere financial ease of the GATE funding which is now available to all eligible students by consolidating the voice of marginalised learners in a conservative tertiary education system.
Codification of the Economic Substance Doctrine and the Gregory Case
Authors: Flesher Tonya K. , Quinn Tina Steward
Published: February 2014

Gregory v. Helvering is a landmark case in the area of corporate reorganizations. The concepts that evolved from Gregory include the business purpose test, continuity of business, the taxpayer's right to minimize tax liability, step transaction doctrine, and the economic substance doctrine. The Treasury Department sought a codification of the economic substance doctrine as a necessary weapon to curb the growth of corporate tax shelters. While the doctrine had been part of the fabric of our tax system since Gregory, it had been eroded by some confusing and conflicting case law. In 2010 (the 75th anniversary of Gregory), Congress codified the economic substance rules. In order to understand this new legislation it is necessary to explore the long and grand history of the Gregory case as a backdrop for consideration of the merits and demerits of the codification of the economic substance doctrine.
Spontaneous regression of lumbar Hansen type 1 disk extrusion detected with magnetic resonance imaging in a dog
Authors: Steffen Frank , Kircher Patrick R. , Dennler Matthias
Published: February 2014

Case Description—A 3-year-old French Bulldog was evaluated because of acute signs of back pain and spastic paraparesis.

Clinical Findings—Neuroanatomic localization indicated a lesion in the T3-L3 spinal cord segment. Magnetic resonance imaging revealed extradural spinal cord compression at the ventral right aspect of the intervertebral disk space L3–4. On the basis of these findings, a diagnosis of sequestrated Hansen type 1 disk extrusion without extradural hemorrhage was made.

Treatment and Outcome—The dog was treated conservatively with cage rest, restricted exercise on a leash, and NSAIDs. Results of follow-up examination 5 weeks later indicated complete resolution of clinical signs, and results of repeated MRI indicated a 69% reduction in the volume of the herniated disk material.

Clinical Relevance—Findings for the dog of this report indicated spinal cord compression attributable to extruded intervertebral disk material resolved. Functional improvements in dogs with such problems may be partly attributable to spontaneous regression of intervertebral disk extrusions.
Spectrin and phospholipids — the current picture of their fascinating interplay
Authors: Bogusławska Dżamila , Machnicka Beata , Hryniewicz-Jankowska Anita , Czogalla Aleksander
Published: February 2014

The spectrin-based membrane skeleton is crucial for the mechanical stability and resilience of erythrocytes. It mainly contributes to membrane integrity, protein organization and trafficking. Two transmembrane protein macro-complexes that are linked together by spectrin tetramers play a crucial role in attaching the membrane skeleton to the cell membrane, but they are not exclusive. Considerable experimental data have shown that direct interactions between spectrin and membrane lipids are important for cell membrane cohesion. Spectrin is a multidomain, multifunctional protein with several distinctive structural regions, including lipid-binding sites within CH tandem domains, a PH domain, and triple helical segments, which are excellent examples of ligand specificity hidden in a regular repetitive structure, as recently shown for the ankyrin-sensitive lipid-binding domain of beta spectrin. In this review, we summarize the state of knowledge about interactions between spectrin and membrane lipids.
Parasites of the head of Scomber colias (Osteichthyes: Scombridae) from the western Mediterranean Sea
Authors: Mele Salvatore , Pennino Maria , Piras Maria , Bellido José , Garippa Giovanni , Merella Paolo
Published: February 2014

The metazoan parasite assemblage of the head of 30 specimens of the Atlantic chub mackerel (Scomber colias) from the western Mediterranean Sea was analysed. Eight species of parasites were found, four mazocraeid monogeneans: Grubea cochlear (prevalence = 10%), Kuhnia scombercolias (59%), K. scombri (52%), Pseudokuhnia minor (86%); three didymozoid trematodes: Nematobothrium cf. faciale (21%), N. filiforme (41%), N. scombri (7%); and one laerneopodid copepod: Clavelissa scombri (7%). Results were compared with previously published data from 14 localities of the eastern Mediterranean Sea and the Atlantic Ocean, using non-parametric univariate and multivariate analyses, and the whole parasite fauna of S. colias was compared with that of the congeners (S. australasicus, S. japonicus and S. scombrus). Parasites showed to reflect the biogeographical and phylogenetic history of host. From a methodological point of view, the use of both non-parametric univariate and multivariate techniques proved to be effective tools to detect dissimilarities between parasite assemblages.
Larval trematodes infecting the South-American intertidal mud snail Heleobia australis (Rissooidea: Cochliopidae)
Authors: Alda Pilar , Martorelli Sergio
Published: February 2014

Larval trematodes infecting the snail Heleobia australis (Cochliopidae) from the Bahía Blanca estuary, Argentina were surveyed for two years. A total of 7,504 snail specimens was dissected and the larval stages of 15 different trematodes were recovered and examined morphologically. These larvae included four species that had previously been reported from H. australis in Brazil, Uruguay, and Argentina: the heterophyid Ascocotyle (Phagicola) longa and the microphallids, Maritrema bonaerense, Maritrema orensense, and Microphallus simillimus. Three other species, the echinostomatid Stephanoprora uruguayensis, the microphallid Levinseniella cruzi, and the psilostomid Psilochasmus oxyurus are reported here for the first time as parasites of H. australis. Eight other trematodes found in H. australis are described and placed in the appropriate superfamilies, families or genera (Cryptogonimidae, Apocreadiidae, Aporocotylidae, Notocotylidae, Haploporidae, Renicolidae, Himasthla, and Renicola). The prevalence of the trematode taxa infecting H. australis in the Bahía Blanca estuary was low (<3%) with a single exception (M. simillimus; >20%). Microphallidae were the richest and the most prevalent family, probably because of the high abundance of crabs — the second-intermediate hosts of certain microphallid species — and the considerable diversity of gulls. Here we compare the parasite assemblage found in the H. australis from Bahía Blanca estuary with other parasite assemblages infecting Heleobia spp. and other rissooids from the rest of the world.
Infections with cardiopulmonary and intestinal helminths and sarcoptic mange in red foxes from two different localities in Denmark
Authors: Al-Sabi Mohammad , Halasa Tariq , Kapel Christian
Published: February 2014

Monitoring parasitic infections in the red fox is essential for obtaining baseline knowledge on the spread of diseases of veterinary and medical importance. In this study, screening for cardiopulmonary and intestinal helminths and sarcoptic mange (Sarcoptes scabiei) was done on 118 foxes originating from two distinct localities in Denmark, (Copenhagen) greater area and southern Jutland. Fifteen parasite species were recorded in 116 foxes (98.3%), nine parasitic species are of zoonotic potential. Parasite diversity was greater in foxes of Copenhagen in terms of overall parasite species richness and species richness of all helminth groups individually: trematodes; cestodes; and nematodes. Six parasite species were recovered from foxes of Copenhagen, but not from foxes of Southern Jutland: Echinochasmus perfoliatus; Echinostoma sp.; Pseudamphistomum truncatum; Dipylidium caninum; Angiostrongylus vasorum; and Sarcoptes scabiei, but Toxascaris leonina was only recorded in foxes of southern Jutland. A high prevalence and abundance of A. vasorum in foxes of Copenhagen was observed. The prevalence of four nematode species; Eucoleus (Capillaria) aerophilus, Uncinaria stenocephala, Toxocara canis, and Crenosoma vulpis, in foxes of both localities were comparable and ranging from 22.9% to 89%. The prevalence of Mesocestoides sp. was significantly higher in foxes of Copenhagen. Taenia spp. were detected using morphological and molecular analysis, which revealed the dominance of T. polyacantha in foxes of both localities. Infections with sarcoptic mange were evident only among foxes of Copenhagen (44.9%), which significantly affected the average weight of the infected animals. Further remarks on the zoonotic and veterinary implications of the parasites recovered are given.
Parasites communities in the clingfish Gobiesox marmoratus from central Chile
Authors: Muñoz Gabriela
Published: February 2014

This study investigated the factors (i.e., season, locality, sampling year, total length and maturity stage of the hosts) that might influence the structure of parasite populations and communities in the clingfish Gobiesox marmoratus. The parasite community was described and analyzed using numerical descriptors, such as prevalence, intensity and species richness, between factors previously mentioned. A total of 260 clingfish were collected from 2 localities of central Chile, four seasons and during 3 year cycles (from July 2006 to July 2009). In the whole clingfish sample, 668 parasites were found, which belonged to 14 parasite taxa; 9 of them were new records in G. marmoratus. Parasite infracommunity richness ranged 0–3 species, although 1 trematode species, Helicometrina nimia, represented 80% of all parasites collected and was the most abundant and prevalent parasite species. The average of parasite abundance and intensity (± SD) was 2.5 ± 8.2 and 7.5 ± 12.7, respectively. Generalized linear model showed that parasite communities were influenced by season, locality, sampling year, and maturity stage when considering the abundance and intensity of parasites. For the parasite richness, only the locality and maturity of fish was determinant for explaining the differences. The populations and communities of the parasite variations were variable due to differences in fish body length because prevalence, abundance and intensity of parasites significantly correlated with the fish body length. Concordantly, maturity fish were longer than immature fish. Thus, clingfish from El Tabo were longest and mature, which harbored higher parasite richness than those fish from Las Cruces.
Oral inoculation of live or dead third-stage larvae of Anisakis simplex in rats suggests that only live larvae induce production of antibody specific to A. simplex
Authors: Abe Niichiro , Teramoto Isao
Published: February 2014

Live Anisakis simplex third-stage larvae (L3) penetrate gastrointestinal mucosa after they are ingested in raw or undercooked seafood, thereafter causing gastrointestinal manifestations and allergic manifestations such as urticaria and anaphylaxis. These allergic reactions are mediated by specific IgE to L3 allergens, especially excretory-secretory (ES) allergens. Recent evidences suggest that only live larvae can cause allergic reactions, although cases attributable to ingestion of cooked, frozen seafood have been reported. Therefore the risk of Anisakis-associated hypersensitivity by ingestion of properly cooked and frozen fish remains controversial. No prior report describes the kinetics of antibody production in experimental animals after oral inoculation with dead L3. This study used ELISA to assess antibody production in rats inoculated orally with dead L3. Positive absorbance value in IgG, IgM, and IgE specific to ES antigen from L3 were found in rats inoculated with live L3 but not with dead L3 (frozen, heated, cut, or homogenized). At one week post re-inoculation with live or frozen L3 to the initially sensitized rats, the absorbance value of the specific IgM and IgE to ES antigen elevated quickly and highly in rats that had been re-inoculated with live L3, but they decreased slightly or did not change in rats inoculated with frozen L3. These results suggest that only ingestion of live L3 can produce the specific antibody and induce initial and secondary sensitizations to L3.
New species of Orientatractis (Nematoda: Atractidae), new species of Rondonia (Nematoda: Atractidae) and other helminths in Austrochaperina basipalmata (Anura: Microhylidae) from Papua New Guinea
Authors: Bursey Charles , Goldberg Stephen , Kraus Fred
Published: February 2014

Two new nematode species, Orientatractis hamabatrachos sp. nov. and Rondonia batrachogena sp. nov. (Nematoda: Atractidae), from the gastrointestinal tract of Austrochaperina basipalmata (Anura: Microhylidae) collected in Papua New Guinea are described. Orientatractis hamabatrachos sp. nov. is characterized by the presence of the cephalic end armed with 4 wellsclerotized structures, consisting of 2 “horns” extending outward and downward and immediately below a single well-sclerotized spine. It differs from 5 congeners in spicule lengths and caudal papillae arrangements. Rondonia batrachogena sp. nov. is characterized by the presence of a female cloaca. It differs from 2 congeners primarily in body size. Orientatractis hamabatrachos sp. nov. and Rondonia batrachogena sp. nov. represent the first species assigned to either genus found to infect anurans or to occur in the Australo-Papuan region.
Adaptation and immunogenicity of Cryptosporidium parvum to immunocompetent mice
Authors: Matsuo Tomohide , Tsuge Yasuko , Umemiya-Shirafuji Rika , Fujino Takashi , Matsui Toshihiro
Published: February 2014

The adaptation and immunogenisity of Cryptosporidium parvum isolated from Siberian chipmunks (SC1 strain) in immunocompetent (ICR) mice were examined. The oocysts were received to the severe combined immunodeficiency (SCID) mice by repeated passage. The oocysts collected from the 18th SCID mice were inoculated to 5 ICR mice. The mice began to shed oocysts from 6 days after inoculation, the patency was 5 days, and the maximum oocysts per gram of feces (OPG) value was 104. The maximum of OPG value was gradually increased by successive passage, and finally that in the 22nd mice reached 106 (patency: 11 days). It is considered that these results indicate completion of their adaptation to ICR mice. To examine the immunogenicity of C. parvum to ICR mice, 8 groups of 5 mice each were inoculated with 1.3 × 106 oocysts of SC1 strain, which were collected after adaptation to SCID mice. All groups shed oocysts from 6th day, and their patency was from 8 to 12 days. On the 21st day after the primary infection, these mice were challenged with 1.3 × 106 oocysts. No oocysts shed from any groups, although 2 control groups shed oocysts from the 6th day, and their OPG values were more than 106. These results suggest that this strain has strong immunogenicity against ICR mice. Therefore, the immunological healthy mice were considered a useful experimental model to investigate immunological and drug treatments in the strain of C. parvum.
Molecular analysis of lungworms from European bison (Bison bonasus) on the basis of small subunit ribosomal RNA gene (SSU)
Authors: Pyziel Anna
Published: February 2014

Dictyocaulosis (Nematoda: Trichostrongyloidea) is a widespread parasitosis of the European bison (Bison bonasus) inhabiting Bialowieza Primeval Forest. Bearing in mind the current coexistence of bison with wild cervids, and with domestic ruminants in the 19th and 20th century, the need arose for molecular identification of lungworm species. Molecular analysis was done on adult lungworms that were obtained from the respiratory track of four free-roaming bison euthanized as a part of the population health control program. As the result of the study four identical small subunit-ribosomal RNA gene sequences from the lungworms were obtained and deposited in GenBank as sequence, 1708 bp long (GenBank KC771250). Comparative analysis of the SSU rRNA sequences revealed the European bison to be a host for the bovine lungworm Dictyocaulus viviparus.
Anisakids of seals found on the southern coast of Baltic Sea
Authors: Skrzypczak Michał , Rokicki Jerzy , Pawliczka Iwona , Najda Katarzyna , Dzido Joanna
Published: February 2014

In the present study 5 grey seals (Halichoerus grypus), 3 common seals (Phoca vitulina) and 1 ringed seal (Pusa hispida) bycaught or stranded on the Polish Baltic Sea coast in years 2000-2006 were investigated for the infestation of parasitic anisakid nematodes. 749 of anisakids were found. The most common were: Contracaecum osculatum (59.3%) and Pseudoterranova decipiens (31.0%). There were also small numbers of Anisakis simplex (0.8%). After performing RFLP three sibling species were found. C. osculatum was identified as C. osculatum C, P decipiens was identified as P. decipiens sensu stricto and A. simplex — A. simplex sensu stricto. Nematodes found in seals were mostly in L4 and adult life stage — both of them were equal with some minor variations among the specimens. Sex ratio was also equal, but there was slight excess of males in some cases. There was a minority of L3 larvae belonging to A. simplex species (0.8%).
Adult-Acquired Flatfoot Deformity and Age-Related Differences in Foot and Ankle Kinematics During the Single-Limb Heel-Rise Test
Authors: Chimenti Ruth L. , Tome Joshua , Hillin Cody D. , Flemister Adolph S. , Houck Jeff
Published: February 2014

Study Design

Cross-sectional laboratory study.

Objective

To compare single-limb heel-rise performance and foot-ankle kinematics between persons with stage 2 adult-acquired flat foot deformity (AAFD) and healthy controls.

Background

The inability to perform a single-limb heel rise is considered a positive functional diagnostic test for AAFD. However, which foot motions contribute to poor performance of this task are not known.

Methods

Fifty individuals participated in this study, 20 with stage 2 AAFD (mean ± SD age, 57.6 ± 11.3 years), and 15 older participants (age, 56.8 ± 5.3 years) and 15 younger participants (age, 22.2 ± 2.4 years) without AAFD as control groups. Forefoot (sagittal plane) and rear foot (sagittal and frontal planes) kinematics were collected using a 3-D motion analysis system. Heel-rise performance (heel height) and kinematics (joint angles, excursions) were evaluated. One-way and 2-way analyses of variance were used to examine differences in heel-rise performance and kinematics between groups.

Results

Individuals with AAFD and older controls demonstrated lower heel-rise height than those in the younger control group (P<.001). Persons with AAFD demonstrated higher degrees of first metatarsal dorsiflexion (P<.001), lower ankle plantar flexion (P<.001), and higher subtalar eversion (P = .027) than those in the older control group. Persons with AAFD demonstrated lower ankle excursion (P<.001) and first metatarsal excursion (P<.001) than those in the older control group, but no difference in subtalar excursion (P = .771).

Conclusion

Persons with stage 2 AAFD did not achieve sufficient heel height during a single-leg heel rise. Both forefoot and rear foot kinematics in the sagittal plane, as opposed to the frontal plane, contributed to the lower heel height in participants with stage 2 AAFD. Older controls demonstrated lower heel-rise height than younger controls, indicating that clinical expectations of heel-rise performance may need to be adjusted for age. J Orthop Sports Phys Ther 2014;44(4):283–290. Epub 25 February 2014. doi:10.2519/jospt.2014.4939
Multiobjective Optimization Model for Transit Fleet Resource Allocation
Authors: Mishra Sabyasachee , Sharma Sushant , Mathew Tom V. , Khasnabis Snehamay
Published: February 2014

State and local transit agencies require government support to preserve their aging transit fleets. With the passage of time, transit fleets get older and require maintenance costs to keep them operational. To provide services at a desired level, transit agencies must maintain a minimum fleet size. Two imperative considerations from the transit planning viewpoint are (a) the remaining life of the total fleet and (b) the cost required to maintain the fleet size. While the former is a quality measure indicating the health of the fleet, the latter is an economic measure requiring minimum expenditure levels. Ideally, agencies would like to maximize the total remaining life of the fleet and minimize the total cost required to maintain the fleet size. In this paper, a multiobjective optimization (MO) model is proposed to incorporate simultaneously the two objectives when subjected to budget and various operational constraints. The MO problem is solved with a classical weight sum approach by using the branch and bound algorithm, which has proved to be better than other solution methodologies. The MO results in Pareto-optimal solutions with possible trade-offs between the two objectives. The model is applied to a large-scale transit fleet system in the state of Michigan. The case study results demonstrate that the proposed model is compact, efficient, robust, and suitable for long-range planning with multiple solutions to choose from a Pareto-optimal frontier. The correlation between decision variables and objective functions has been investigated in-depth, providing important insights. The proposed model can act as a tool for resource allocation for state and local agency transit fleets.
How Close is Close Enough?
Authors: Cummins Ben , Spitz Greg , O'Malley Tara P. , Campbell Margaret
Published: February 2014

Stagnant budgets and growing rates of Internet access have increased the appeal of replacing traditional survey methods with electronic ones. Online surveys are particularly appealing in the public transit industry because of the expense and logistical difficulty of surveying customers onboard buses and trains. It is therefore critical to understand, quantify, and test the differences between onboard versus online transit survey data. Traditional hypothesis tests are designed to show that two sample statistics most likely come from different populations. However, failing to find a difference cannot be interpreted as evidence that there is no difference. Furthermore, a difference may be statistically significant but so small as to provide no practical insight (which often happens when working with large sample sizes). Statistical equivalence testing provides an analytical framework with which to evaluate whether two data sets are similar enough to be interchangeable (i.e., statistically equivalent). The paper describes statistical equivalence tests conducted on customer satisfaction data collected onboard transit systems and data collected electronically with e-mail lists from users of the same systems. Researchers compared proportions of satisfied customers across various economic and travel behavior characteristics between these data sets. Within the chosen threshold of .05 (statistics within 5 percentage points of one another), one of the two data sets evaluated shows strong evidence of equivalence between onboard and online survey methods, while the other data set shows strong evidence of nonequivalence. Findings support the idea that, at least in some cases, online surveys can substitute for onboard ones.
Perspectives of the Operational Performance of Public Transportation Agencies with Data Envelopment Analysis Technique
Authors: Arman Mohammad , Labi Samuel , Sinha Kumares C.
Published: February 2014

This paper presents a framework for comparative assessment of the operational productivity and efficiency of transit agencies. Inputs from selected public transit agencies in Indiana, including annual operating expenses, number of employees, and total fuel consumption, and outputs, including the total ridership and total vehicle miles traveled during an 8-year period (2002–2009), were used to construct relative efficiency scores through data envelopment analysis. In addition, the changes in productivity during the analysis period were quantified by using the Malmquist productivity index. The Malmquist indexes were decomposed into two components, namely, the frontier shift effect and the catch-up effect, to account for industrywide productivity changes and individual agency-level changes, respectively. The methodology is expected to help transit managers not only to assess the performance of their transit systems compared with peer systems but also to identify potential areas for improvement. The approach can also be useful to state transportation agencies in their transit subsidy allocations.
Intraurban Rail Access
Authors: Zuniga Kelly D. , Bunker Jonathan M. , Bevrani Kaveh
Published: February 2014

This project advances the current understanding of intraurban rail passengers and their travel experiences to help rail industry leaders tailor policy approaches to fit specific, relevant segments of their target population. Using a Q-sorting technique and cluster analysis, preliminary research identified five perspectives occurring in a small sample of rail passengers who varied in their frequency and location of rail travel as well as certain sociodemographic characteristics. Revealed perspectives (named to capture the gist of their content) included “Rail travel is about the destination, not the journey”; “Despite challenges, public transport is still the best option”; “Rail travel is fine”; “Rail travel? So far, so good”; and “Bad taste for rail travel.” This paper discusses each of the perspectives in detail and considers them in relation to tailored policy implications. An overarching finding from this study is that improving railway travel access requires attention to physical, psychological, financial, and social facets of accessibility. For example, designing waiting areas to be more socially functional and comfortable has the potential to increase ridership by addressing social forms of access, decreasing perceived wait times, and making time at the station feel like time well spent. Even at this preliminary stage, the Q-sorting technique promises to provide a valuable, holistic, albeit fine-grained, analysis of passenger attitudes and experiences that will assist industry efforts in increasing ridership.
Passenger -Focused Management Approach to Measurement of Train Delay Impacts
Authors: Barron Alexander , Melo Patricia C. , Cohen Judith M. , Anderson Richard J.
Published: February 2014

Train delay incidents have major effects on transit service reliability and on customer satisfaction. Operators have long focused efforts on preventing such incidents. While this action is important, the fact that all transit operations inevitably face some degree of delay and disruption from incidents means that operators must also dedicate attention to reducing the duration of incidents and the time to restore normal operations after incidents occur. To be able to do this, it is necessary to measure the total impact of incidents on train service and customers. This research uses data from the CoMET and Nova metro benchmarking groups to investigate the ways in which transit operators can better measure the full effects of incidents on train service and customers. The key benefit of such a passenger-focused approach is that it enables transit managers to direct resources for incident response and recovery better, as well as support the case for strategic investments. This research has shown that most operators measure and report only the frequency of incidents. Of the 22 metros interviewed, only two were able to provide detailed data to estimate the number of passengers affected by incidents. It is no coincidence that the only two metros able to provide detailed data are in fact two of the most reliable in the group.
Pedestrian Route Choice of Vertical Facilities in Subway Stations
Authors: Srikukenthiran Siva , Fisher Daniel , Shalaby Amer , King David
Published: February 2014

Transit infrastructure is under pressure. As the trends toward greater urbanization and more sustainable mobility continue, that pressure is likely to increase. Finding ways to accommodate passengers more effi-ciently in existing transit facilities will become of ever greater importance, as will the tools and techniques to assess pedestrian movement. The suite of pedestrian analysis tools is reliant on first principles knowledge and research, where gaps exist. This paper describes research that has been completed to fill one such gap, namely rider choice at vertical circulation. First, field research was conducted on the Toronto Transit Commission subway system in Canada. Key explanatory variables were then tested for significance, including total height, density of flow, rate of opposing flow, and mobility of the individuals. On the basis of this analysis, a series of aggregate logistic regression models is proposed to explain pedestrian choice at colocated elements of vertical transport, specifically, stair-versus-escalator choice. Validation data indicate that the model generates values that provide a good fit with observed data.
Effects of Fare Payment Types and Crowding on Dwell Time
Authors: Fletcher Grant , El-Geneidy Ahmed
Published: February 2014

Dwell time, the time a transit vehicle spends stopped to serve passengers, contributes to the total reliability of transit service. Dwell time is affected by factors such as passenger activity, bus crowding, fare collection method, driver experience, and time of day. The types of effects crowding can have on dwell time are debatable because of its interaction with passenger activity and inaccuracies in its calculation. Different payment methods also have an effect on dwell time. This debate can be linked to the absence of appropriate data that can actually capture the real effects of these variables. This research attempts to determine the influence of crowding and fare payment on dwell time through manual data collection. The study was conducted along three heavily used bus routes in the Trans-Link system in Vancouver, British Columbia, Canada. Multiple regression dwell time models are performed by using a traditional model and a new expanded model with the additional details that manually collected data provide. The traditional model overestimated dwell times because of a lack of detail in fare payment and crowding, while the expanded model showed that crowding significantly increased dwell time after approximately 60% of bus capacity was surpassed. Fare payment methods had various positive effects on dwell time, with different magnitudes. This research can help public transit planners and operators develop better guidelines for fare payment methods as well as policies associated with crowding.
Unbanked Transit Riders and Open Payment Fare Collection
Authors: Brakewood Candace , Kocur George
Published: February 2014

Several transit agencies are considering accepting contactless credit and debit cards directly at turnstiles and bus fare boxes. By using the expertise and scale economies of the payments industry, agencies may reduce fare collection costs and improve regional interoperability and ease of use. One issue with bankcard-based fare collection systems is how to serve transit riders who do not have or do not want to use contactless bank-cards. In this paper, based on Chicago, Illinois, data, discrete choice models of the likelihood of transit users to have credit and debit cards or to use alternative financial services such as currency exchanges are estimated. A significant fraction of transit riders in Chicago do not have credit or debit cards; these riders come from groups with lower incomes, lower levels of education, and minority ethnicities. To meet the needs of this unbanked group of transit users, agencies may accept cash fares, agency-issued cards, or payment industry–issued prepaid cards that can be loaded with cash at retail locations or in rail stations. These options serve unbanked users to varying degrees and with different costs to the agency.
Modeling Water Vapor Diffusion in Pavement and Its Influence on Fatigue Crack Growth of Fine Aggregate Mixture
Authors: Tong Yunwei , Luo Rong , Lytton Robert L.
Published: February 2014

This paper describes two key objectives. The first objective is to develop a method of predicting and quantifying the amount of water that can enter into a pavement system by vapor transport. The second objective is to identify the extent to which fatigue crack growth in pavement would result from such moisture accumulation. To fulfill these two objectives, a diffusion model was first established to illustrate the wetting process of the surface asphalt layer caused by the vapor migration from subgrade soil into the upper layer. Second, to quantify the degree of moisture damage induced by water vapor diffusion, fine aggregate mixture specimens were fabricated and conditioned at different levels of relative humidity (RH) in closed vacuum desiccators that allow little temperature fluctuation. Moreover, the moisture-conditioned specimens were tested with a newly developed repeated direct tension (RDT) test method to evaluate the fatigue crack growth. The RDT test greatly reduced the stress state complexity within the specimens by evenly distributing stress over the cross-sectional area of the cylindrical specimen. Compared with the previous torsional test, the newly proposed test protocol was more efficient in characterizing the moisture susceptibility of the asphalt mixture. A major finding of this study is that higher RH levels in an asphalt surface layer will induce significantly higher crack growth rates.
Local Practice of Assessing Dynamic Modulus Properties for Washington State Mixtures
Authors: Shen Shihui , Yu Huanan , Willoughby Kim A. , DeVol Joseph R. , Uhlmeyer Jeffrey S.
Published: February 2014

The dynamic modulus (|E*|) is one of the key elements of a mechanistic–empirical–based flexible pavement design procedure. The dynamic modulus is used to characterize the material properties of asphalt mixtures and to determine the stress–strain responses of a pavement at different loading conditions. The dynamic modulus is also a direct input parameter in several pavement performance models to estimate field fatigue cracking and rutting performance. To provide a better understanding of the local materials, this study aimed to test the typical asphalt mixtures used by the Washington State Department of Transportation and to establish a material catalog for dynamic modulus. In this study, seven plant-produced mixtures from five regions of Washington State were sampled and tested. These mixtures represented the typical asphalt binder, gradation, and mix designs of the state. One warm-mix asphalt project was also included in the analysis. On the basis of the experimental results, it was found that mix properties including air voids and binder properties had an important impact on the dynamic modulus. Because of the limited aggregate gradations, the effect of aggregate gradation on the dynamic modulus was inconclusive. The measured dynamic modulus data were compared with the prediction results by using the traditional Witczak E* model, the new Witczak E* model, and the Hirsch model. The Hirsch model was found to be the most promising and was modified further by including mastic property into the model. The modified Hirsch model greatly improved prediction quality and can be used as both a design tool and a screening tool to estimate the dynamic modulus of a mixture at early stages of the mix design process.
Mechanistic-Based Approach to Evaluate Rutting Susceptibility of Hot-Mix Asphalt Mixtures by Use of Dynamic Triaxial Testing
Authors: Ulloa Alvaro , Hajj Elie Y. , Sebaaly Peter E.
Published: February 2014

Designing appropriate asphalt mixture type and properties is an important task that pavement engineers perform routinely. For many years, this key decision has been made by relying on empirical procedures that might not be representative of the specific project condition. Therefore, there is a need to develop an advanced yet simplified approach to assessing, on the basis of closely simulated field conditions, the rutting susceptibility of hot-mix asphalt (HMA) mixtures under a given set of traffic loads and environmental conditions. This paper presents a new mechanistic-based approach that evaluates asphalt mixtures by using the repeated load triaxial (RLT) test at field-representative testing conditions to determine the critical temperature of the HMA. An HMA mixture was considered appropriate for a specific project location when the determined critical temperature was greater than the effective asphalt pavement temperature for rutting determined by using the Mechanistic–Empirical Pavement Design Guide software. Predictive equations that accounted for the actual project characteristics, such as climate conditions, material characteristics, operational speed, and traffic loading, were developed to estimate the effective asphalt pavement temperature. Nine HMA mixtures were characterized and analyzed for rutting behavior. The critical temperature for each HMA mixture was obtained with RLT results and actual field performance. Flow number criteria as a function of traffic level were also developed. The proposed approach was validated by using three additional mixtures from Nevada and two mixtures from the WesTrack accelerated test facility. Good agreement between laboratory results and field performance was achieved and supports the appropriateness of the proposed approach.
Permanent Deformation Characterization of Asphalt Mixtures by Using Incremental Repeated Load Testing
Authors: Azari Haleh , Mohseni Alaeddin
Published: February 2014

Currently, flow number (FN) is being used for measuring the permanent deformation resistance of asphalt mixtures. The provisional AASHTO TP 79 test method specifies the requirements of the FN test; however, there are undefined levels of test variables, such as temperature, axial stress, and confinement. Agreeable FN criteria that can reliably discriminate between various mixtures have not been established. As the asphalt industry continues to develop more sophisticated mixtures (warm mix, reclaimed asphalt pavement, and reclaimed asphalt shingles), the FN value has failed to capture the true complexity of the asphalt mixtures. These shortcomings and the unpredictable testing time of the FN test have affected its usefulness for evaluating high-temperature performance of asphalt mixtures. A new test procedure for evaluation of the rutting susceptibility of asphalt mixtures is being proposed. The new procedure is conducted at one temperature and three stresses on the same replicate in three increments of 500 cycles and takes only 25 min to complete. The property of the test is the permanent strain attributable to the last cycle of each test increment (minimum strain rate, MSR). A master curve is developed by plotting the MSR values versus parameter TP, which is a product of temperature and pressure. The MSR master curve represents the unit rutting damage (rut per axle) of asphalt mixtures at any stress and temperature and can be used in the laboratory for material characterization, mix design verification, mixture ranking, or pavement design applications to predict rut depth for project climate and design traffic.
Prediction of Capacity for Roundabouts Based on Percentages of Trucks in Entry and Circulating Flows
Authors: Lee Chris , Khan Moayed Naeem
Published: February 2014

The objective of this study was to estimate capacity at roundabouts by developing a method to adjust gap acceptance parameters for trucks. Because drivers' gap acceptance behavior is affected not only by trucks in the entry flow but also by trucks in the circulating flow, critical headways were separately estimated for various combinations of vehicle types in the circulating flow at 11 roundabouts in Ontario, Canada; Vermont; and Wisconsin. Because the percentage of trucks was different for different entry legs, the critical headways and follow-up times were estimated at each leg separately. Variations in gap acceptance behavior were also observed at one of the 11 roundabouts for 13 consecutive days to evaluate the statistical significance of differences in behavior between two entry legs. The results showed that a new adjusted critical headway improved the accuracy of capacity estimation and that the critical headways were significantly different between the two legs with different percentages of trucks in the entry flow. The study provided insight into how to capture the effect of trucks on roundabout capacity.