bluuebunny/crossref_metadata_2025 huggingface dataset:
Hungarian consensus guideline for the diagnosis and treatment of B, C, and D viral hepatitis
Authors: Makara Mihály , Horváth Gábor , Gervain Judit , Pár Alajos , Szalay Ferenc , Telegdy László , Tornai István , Újhelyi Eszter , Hunyady Béla
Published: February 2012

More than 1% of the Hungarian population is infected with hepatitis B, C, or D viruses. Since 2006 the diagnostics and therapy of these infections are carried out in treatment centers according to national guidelines – since 2010 according to financial protocols. The consensus-based guidelines for 2012 are published in this paper. The guidelines stress the importance of quick and detailed virologic evaluations, the applicability of transient elastography as an acceptable alternative of liver biopsy in this regard, as well as the relevance of appropriate consistent follow up schedule for viral response during therapy. The first choice of therapy in chronic hepatitis B infection is pegylated interferon for 48 weeks or continuous entecavir therapy. The later must be continued for at least 6 months after hepatitis B surface antigen (HBsAg) seroconversion. Tenofovir disoproxil fumarat is not yet reimbursed by the National Health Insurance Fund. Adefovir dipivoxil is recommended mainly in combination therapy. Lamivudine is no longer a first choice; patients currently taking lamivudine must switch if response is inadequate. Appropriate treatment of patients taking immunosuppressive medications is highly recommended. Pegylated interferon based therapy is recommended for the treatment of concomitant hepatitis D infection. Treatment naive chronic hepatitis C patients should initially receive pegylated interferon and ribavirin dual combination therapy. In genotype 1 infection if response is insufficient at 4 or 12 weeks one of the two new direct acting antivirals (boceprevir or telaprevir) should be added. The length of treatment is usually 48 weeks; in cases of extended early viral response shorter courses are recommended. Previous treatment failure patients with genotype 1 infection should receive a protease inhibitor backed triple combination therapy, mostly for 48 weeks. However, relapsers without cirrhosis and with extended rapid viral response, shorter telaprevir based combination therapy is sufficient. Drug-drug interactions as well as emergence of viral resistance are of particular importance. For genotype 2 or 3 HCV infections 24 weeks, for genotype 4 infections 24, 48 or 72 weeks of pegylated interferon plus ribavirin therapy is recommended in general. The guidelines published here become protocols when published as official publications of the Hungarian Health Authority. Orv. Hetil., 2012, 153, 375–394.
Avaliação da influência da quantidade de exposição gengival na estética do sorriso
Authors: Suzuki Larissa , Machado André Wilson , Bittencourt Marcos Alan Vieira
Published: February 2012

OBJETIVO: o objetivo desse trabalho foi avaliar a influência da quantidade de exposição gengival na estética do sorriso. MÉTODOS: foram utilizadas duas fotografias do sorriso (uma facial e outra aproximada) e uma intrabucal frontal de quatro indivíduos (um homem e uma mulher negros, e um homem e uma mulher brancos). As fotografias foram manipuladas no computador e cinco imagens foram criadas para cada fotografia original, com diferentes graus de exposição gengival: 0mm, 1mm, 3mm, 5mm e 7mm. Em seguida, as imagens foram submetidas à avaliação de 60 indivíduos que atribuíram, em uma escala visual analógica, uma nota de zero a dez para cada imagem. RESULTADOS E CONCLUSÕES: a análise estatística e os resultados encontrados demonstraram que os níveis de exposição gengival de 0mm e 1mm apresentaram as maiores notas médias, com valores de 6,6 e 6,2, respectivamente, e não apresentaram diferenças estatísticas entre si (p>0,05). As exposições gengivais de 3mm, 5mm e 7mm receberam notas menores e decrescentes de 5,0; 3,5 e 2,9, respectivamente, sem diferença estatística entre os níveis de 5mm e 7mm (p>0,05). Além disso, o uso de fotos do sorriso aproximado ou da face frontal sorrindo não demonstrou qualquer diferença estatística (p>0,05).
Alterações dentoesqueléticas decorrentes do tratamento com aparelho ortopédico funcional Twin Block em pacientes portadores de má oclusão de Classe II esquelética
Authors: Brunharo Ione Helena Vieira Portella , Quintão Cátia Abdo , Almeida Marco Antonio de Oliveira , Motta Alexandre , Barreto Sunny Yamaguche Nogueira
Published: February 2012

OBJETIVO: este estudo clínico prospectivo avaliou as alterações dentoesqueléticas em pacientes portadores de más oclusões de Classe II esquelética e dentária, tratados com o aparelho ortopédico funcional Twin Block (TB). MÉTODOS: a amostra foi dividida em dois grupos de 19 indivíduos cada: o grupo TB, com idade média de 9 anos e 6 meses (d.p. = 10 meses); e o grupo controle, com idade média de 9 anos e 9 meses (d.p. = 13 meses), ambos situados na fase de pré-surto de crescimento puberal. O teste t de Student não paramétrico mostrou que a amostra era homogênea para os valores cefalométricos ao início do estudo. Radiografias cefalométricas ao início do estudo (T1) e ao final dos 12 meses (T2) foram obtidas de todos os pacientes. Os testes de Wilcoxon e Mann-Whitney foram utilizados para avaliar as mudanças intragrupos e intergrupos em T1 e T2. RESULTADOS: a relação molar de Classe I foi obtida em 15 indivíduos do grupo tratado, enquanto nenhuma modificação ocorreu no grupo controle. Não foram observadas alterações na maxila e no padrão vertical de crescimento facial. Um aumento significativo do comprimento total mandibular e um deslocamento anterior da mandíbula ocorreram no grupo tratado (p<0,05), assim como a redução do overjet, influenciado pela significativa retroinclinação do incisivo superior e vestibularização do incisivo inferior (p<0,05). CONCLUSÕES: o tratamento da Classe II em pacientes brasileiros apresentou efeitos esqueléticos e dentários, incluindo aumento do comprimento mandibular e compensação dos incisivos, respectivamente.
Phylogenetic diversity–area curves
Authors: Helmus Matthew R. , Ives Anthony R.
Published: February 2012

Phylogenetic diversity–area curves are analogous to species–area curves and quantify the relationship between the phylogenetic diversity of species assemblages and the area over which assemblages are sampled. Here, we developed theoretical expectations of these curves under different ecological and macroevolutionary processes. We first used simulations to generate curves expected under three ecological community assembly processes: species sorting, where species have distinct environmental preferences; random placement, where species have no environmental preference but vary in their prevalence across communities; and limited dispersal, where species have no environmental preference but vary in their ability to disperse. Second, we simulated curves expected across regions (e.g., across oceanic islands) that are derived from colonization among regions, within‐region speciation, and extinction. We also computed curves for two data sets, one on forest plots along an elevation gradient and the other on Caribbean islandAnolislizards. Of the three ecological processes, only species sorting produced strong relationships between phylogenetic diversity and area. The forest plot curves matched the species‐sorting expectation, but only when phylogenetic repulsion (that caused closely related species to be found in similar habitats but not in the same plots) was also included in the simulation. Strong relationships between regional phylogenetic diversity and area were simulated if species were derived only from within‐region speciation; colonizations among regions obscured the pattern. Similarly, larger Caribbean islands had more within‐island speciation and contained moreAnolisphylogenetic diversity than smaller islands, but colonizations among islands obscured this relationship. This work furthers our understanding of the processes that govern the phylogenetic diversity of ecological communities and biogeographic regions.
Floral diversity and community structure in Pedicularis (Orobanchaceae)
Authors: Eaton Deren A. R. , Fenster Charles B. , Hereford Joe , Huang Shuang-Quan , Ree Richard H.
Published: February 2012

A pervasive hypothesis at the interface of ecology and evolution is that biotic interactions contribute to regional biodiversity by accelerating adaptation and speciation. We investigated this question in the context of closely related, bumble bee‐pollinated plants (Pedicularis spp.) in the Hengduan Mountains of south‐central China, where they exhibit spectacular levels of richness, endemism, and floral diversity. Because these species co‐occur frequently, flower synchronously, and share pollinators during the brief reproductive season, we predict that pollinator‐mediated interactions may influence their community assembly and evolutionary diversification. If disparity in floral traits reduces competitive interactions between species, as would happen if floral isolation mitigates reproductive interference caused by heterospecific pollen flow, then species with dissimilar flowers should co‐occur more often, yielding greater floral diversity at local scales than expected by chance. Moreover, if such interactions have repeatedly driven character displacement, then floral traits should exhibit homoplasy, the phylogenetic signature of labile evolution. We present evidence supporting these predictions, and find that local species richness is best explained by a model including both floral diversity and phylogenetic distance. Our results suggest that a dynamic mosaic of pollinator‐mediated interactions among Pedicularis in the Hengduan region promotes ecological sorting through recurrent selection against reproductive interference, causing rapid species turnover at local scales, and accelerating the rate of floral divergence among species. Together these processes may have contributed to the remarkable accumulation of florally diverse species of Pedicularis endemic to the Hengduan Mountains biodiversity hotspot.
Are Psychiatric Diagnoses an Obstacle for Research and Practice? Reliability, Validity and the Problem of Psychiatric Diagnoses. The Case of GAD
Authors: Faravelli Carlo , Castellini Giovanni , Landi Monica , Brugnera Andrea
Published: February 2012

The present article focused on the problem of validity, reliability and specificity of psychiatric diagnoses.

The authors moved by the concept of syndrome, defined by Sydenham in the 18th century as a constellation of several interrelated symptoms, showing a stable, characteristic structure and a peculiar prognosis, in order to analyse the peculiarity of the current psychiatric nosology. In our opinion, the current nosographic system based on DSM-IV criteria, prevents psychiatry from benefiting of the significant technological progress that has led the rest of medical sciences to important clinical achievements in the last 20 years. The case of Generalized Anxiety Disorder was taken as an example of a disease characterized by unstable diagnostic criteria, high rate of comorbidity and uncertain boundaries. An analysis of the data from the Sesto Fiorentino study was performed to investigate the presence of common mood and anxiety symptoms across the most represented DSM IV diagnoses, in order to evaluate the specificity of these symptoms.

The results supported the hypothesis of a low specificity of these symptoms, suggesting the need for psychiatry to find new and more specific markers and instruments.
The Epidemiology, Genetics and Future Management of Syndactyly
Authors: Jordan D , Hindocha S , Dhital M , Saleh M , Khan W
Published: February 2012

Syndactyly is a condition well documented in current literature due to it being the most common congenital hand defect, with a large aesthetic and functional significance.

There are currently nine types of phenotypically diverse non-syndromic syndactyly, an increase since the original classification by Temtamy and McKusick(1978). Non-syndromic syndactyly is inherited as an autosomal dominant trait, although the more severe presenting types and sub types appear to have autosomal recessive and in some cases X-linked hereditary.

Gene research has found that these phenotypes appear to not only be one gene specific, although having individual localised loci, but dependant on a wide range of genes and subsequent signalling pathways involved in limb formation. The principal genes so far defined to be involved in congenital syndactyly concern mainly the Zone of Polarizing Activity and Shh pathway.

Research into the individual phenotypes appears to complicate classification as new genes are found both linked, and not linked, to each malformation. Consequently anatomical, phenotypical and genotypical classifications can be used, but are variable in significance, depending on the audience.

Currently, management is surgical, with a technique unchanged for several decades, although future development will hopefully bring alternatives in both earlier diagnosis and gene manipulation for therapy.
Management of Extensor Tendon Injuries
Authors: Griffin M , Hindocha S , Jordan D , Saleh M , Khan W
Published: February 2012

Extensor tendon injuries are very common injuries, which inappropriately treated can cause severe lasting impairment for the patient. Assessment and management of flexor tendon injuries has been widely reviewed, unlike extensor injuries. It is clear from the literature that extensor tendon repair should be undertaken immediately but the exact approach depends on the extensor zone. Zone I injuries otherwise known as mallet injuries are often closed and treated with immobilisaton and conservative management where possible. Zone II injuries are again conservatively managed with splinting. Closed Zone III or ‘boutonniere’ injuries are managed conservatively unless there is evidence of displaced avulsion fractures at the base of the middle phalanx, axial and lateral instability of the PIPJ associated with loss of active or passive extension of the joint or failed non-operative treatment. Open zone III injuries are often treated surgically unless splinting enable the tendons to come together. Zone V injuries, are human bites until proven otherwise requires primary tendon repair after irrigation. Zone VI injuries are close to the thin paratendon and thin subcutaneous tissue which strong core type sutures and then splinting should be placed in extension for 4-6 weeks. Complete lacerations to zone IV and VII involve surgical primary repair followed by 6 weeks of splinting in extension. Zone VIII require multiple figure of eight sutures to repair the muscle bellies and static immobilisation of the wrist in 45 degrees of extension. To date there is little literature documenting the quality of repairing extensor tendon injuries however loss of flexion due to extensor tendon shortening, loss of flexion and extension resulting from adhesions and weakened grip can occur after surgery. This review aims to provide a systematic examination method for assessing extensor injuries, presentation and management of all type of extensor tendon injuries as well as guidance on mobilisation pre and post surgery.
Advances of Peripheral Nerve Repair Techniques to Improve Hand Function: A Systematic Review of Literature
Authors: P Mafi , S Hindocha , M Dhital , M Saleh
Published: February 2012

Concepts of neuronal damage and repair date back to ancient times. The research in this topic has been growing ever since and numerous nerve repair techniques have evolved throughout the years. Due to our greater understanding of nerve injuries and repair we now distinguish between central and peripheral nervous system. In this review, we have chosen to concentrate on peripheral nerve injuries and in particular those involving the hand. There are no reviews bringing together and summarizing the latest research evidence concerning the most up-to-date techniques used to improve hand function. Therefore, by identifying and evaluating all the published literature in this field, we have summarized all the available information about the advances in peripheral nerve techniques used to improve hand function. The most important ones are the use of resorbable poly[(R)-3-hydroxybutyrate] (PHB), epineural end-to-end suturing, graft repair, nerve transfer, side to side neurorrhaphy and end to side neurorrhaphy between median, radial and ulnar nerves, nerve transplant, nerve repair, external neurolysis and epineural sutures, adjacent neurotization without nerve suturing, Agee endoscopic operation, tourniquet induced anesthesia, toe transfer and meticulous intrinsic repair, free auto nerve grafting, use of distal based neurocutaneous flaps and tubulization. At the same time we found that the patient’s age, tension of repair, time of repair, level of injury and scar formation following surgery affect the prognosis. Despite the thorough findings of this systematic review we suggest that further research in this field is needed.
Carpal Tunnel Syndrome: A Review of the Recent Literature
Authors: Ibrahim I , Khan W.S , Goddard N , Smitham P
Published: February 2012

Carpal Tunnel Syndrome (CTS) remains a puzzling and disabling condition present in 3.8% of the general population. CTS is the most well-known and frequent form of median nerve entrapment, and accounts for 90% of all entrapment neuropathies. This review aims to provide an overview of this common condition, with an emphasis on the pathophysiology involved in CTS. The clinical presentation and risk factors associated with CTS are discussed in this paper. Also, the various methods of diagnosis are explored; including nerve conduction studies, ultrasound, and magnetic resonance imaging.
A Systematic Review of Dynamometry and its Role in Hand Trauma Assessment
Authors: P Mafi , R Mafi , S Hindocha , M Griffin , W Khan
Published: February 2012

The dynamometer was developed by American neurologists and came into general use in the late 19th century. It is still used in various ways as a diagnostic and prognostic tool in clinical settings. In this systematic review we assessed in detail the different uses of dynamometry, its reliability, different dynamometers used and the influence of rater experience by bringing together and evaluating all published literature in this field. It was found that dynamometry is applied in a wide range of medical conditions. Furthermore, the great majority of studies reported acceptable to high reliability of dynamometry. Jamar mechanical dynamometer was used most often in the studies reviewed. There were mixed results concerning the effect of rater experience. The factors influencing the results of dynamometry were identified as age, gender, body weight, grip strength, BMI, non/dominant hand, assessing upper/lower limbs, rater and patient’s strength and the distance from the joint where the dynamometer is placed. This review provides an understanding of the relevance and significance of dynamometry which should serve as a starting point to guide its use in hand trauma assessment. On the basis of our findings, we suggest that hand dynamometry has a great potential, and could be used more often in clinical practice.
A Baselining of Alternative Fuel Usage
Authors: Fuller Jack , Bessette Robert
Published: February 2012

Alternative fuel usage is becoming a more and more prevalent topic of discussion and important research area for
those who work in the energy field and perform research on energy topics. This interest is due to the dwindling supply and
increasing cost of more traditional energy supplies, as well as environmental considerations. Bio-fuels have now become an
important research area as they have the potential to be able to replace some portion of the current United States dependence on
traditional energy sources.

This research project performed a baselining effort on as large a sample of solid fuel boilers (utilizing the United States
Environmental Protection Agency's (EPA) data) as was possible given the time and resource constraints of the project. This
baselining effort in particular focused on alternative fuel usage commonly used in facilities surveyed across the United States.

It is felt that the baselining report generated as a result of this effort will provide valuable assistance to researchers as they
continue to analyze the impact of alternative fuel usage (particularly the use of bio-fuels). This is a relatively new research field
that will impact much of the focus on energy generation and fuel supplies for many years to come.
CTNNB1 Genotyping and APC Screening in Pediatric Desmoid Tumors: A Proposed Algorithm
Authors: Wang Wei-Lien , Nero Christopher , Pappo Alberto , Lev Dina , Lazar Alexander J. , López-Terrada Dolores
Published: February 2012

Desmoid fibromatosis is a rare, locally aggressive fibroblastic/myofibroblastic tumor that occasionally involves children. We examined a series of pediatric desmoids for CTNNB1 mutations, seen in sporadic tumors, and APC germline mutations, associated with familial adenomatous polyposis (FAP). Forty-four desmoids in pediatric patients were identified in the pathology files of 2 large referral centers (1995–2009). Clinical charts were reviewed for history of FAP. Germline APC gene mutations were determined on blood samples from patients presenting with FAP. Immunohistochemistry for beta-catenin was performed. CTNNB1 genotyping was done by Sanger sequencing on formalin-fixed paraffin-embedded tissue. CTNNB1 mutations were observed in 29 of 44 (66%) desmoids, with 3 mutations identified: T41A (64%), S45F (29%), and S45P (7%). Germline APC mutations were present in 7 (16%) desmoid patients. Eight (18%) patients had desmoids that were wild type for CTNNB1 and had no known clinical signs or family history suspicious for FAP at the time of testing or with extended follow up ( n = 6). Beta-catenin nuclear labeling was observed in 38 of 41 (92%) tested cases, 34 (89%) of which showed mutations in either CTNNB1 ( n = 29) or APC ( n = 5). Nuclear localization of beta-catenin was seen in the majority of pediatric desmoids and was most often associated with somatic mutations in CTNNB1. However, a significant proportion of pediatric patients harbored germline mutations in APC. Given the implications, genetic counseling is recommended for children diagnosed with desmoid tumors lacking CTNNB1 mutations because this population is enriched for FAP patients.
Myxoinflammatory Fibroblastic Sarcoma: Report of a Case and Review of the Literature
Authors: Alaggio Rita , Coffin Cheryl M. , Dall'Igna Patrizia , Bisogno Gianni , Olivotto Andrea , Di Venosa Benedetta , Fassina Ambrogio
Published: February 2012

Myxoinflammatory fibroblastic sarcoma (MIFS) is a low-grade sarcoma generally arising in adults. We present a case of MIFS in a 5-year-old boy with a palpable nodule in the subcutaneous tissue of the scalp. We carried out a literature review to evaluate the diagnostic patterns based on histologic and cytologic features and possible pitfalls and misdiagnoses. A systematic search for articles of interest published between 1995 and 2011 was performed in MEDLINE and PubMed using the words “myxoinflammatory fibroblastic sarcoma,” “myxohyaline tumor,” and “inflammatory myxoid tumor.” Histology and cytology have a pivotal role in the differential diagnosis between MIFS and other potential soft-tissue mimics, such as nodular and proliferative fasciitis and inflammatory myofibroblastic tumor. Fine-needle aspiration cytology is a safe and useful tool for the diagnosis of pediatric patients with MIFS and is important for an accurate and precise preoperative workup to optimize subsequent management and treatment.
Computerised static posturography in neurology
Authors: Vališ Martin , Dršata Jakub , Kalfeřt David , Semerák Pavel , Kremláček Jan
Published: February 2012

Posturography is a general term for techniques used to measure postural stability on static or dynamic measuring platforms. The principle of static computerised posturography (SCPG) is the detection of the centre of foot pressure (CFP) in upright stance on a posturography platform. Our communication deals with the importance of SCPG in differential topodiagnosis of vestibular syndromes in neurology. The set of examinations and evaluations carried out was divided among a control group of healthy subjects (77), a group of subjects with peripheral vestibular disorder (159), and a group of subjects with a non-peripheral balance disorder (82). Results obtained through the measurements were evaluated using descriptive statistics procedures and basic numerical and graphic statistical characteristics of the given groups. Our observations demonstrate that posturography is a valuable auxiliary test for balance disorders, especially given the lack of more suitable tests. According to our results, SCPG can be used for a rough differential topodiagnosis of balance disorders in neurology.
B-cell activating factor (BAFF) — a new factor linking immunity to diet?
Authors: Bienertova-Vasku Julie , Bienert Petr , Zlamal Filip , Tomandl Josef , Forejt Martin , Tomandlova Marie , Vavrina Martin , Kudelková Jana , Splichal Zbynek , Vasku Anna
Published: February 2012

B cell activation factor (BAFF) is a recently discovered member of the TNF ligand superfamily secreted by adipocytes, previously linked to autoimmune and lymphoproliferative disease. The aim of this study was to investigate the relationship between BAFF plasma levels and the non-modified, usual dietary composition as well as obesity-related anthropometric parameters in a cohort of 58 obese and non-obese Central-European Caucasian individuals. We found that BAFF had an independent predictive role for percentage of body fat; moreover, BAFF levels were correlated with waist and hip circumference. BAFF plasma levels were also significantly correlated with investigated dietary composition based on the 7-day food records, as the BAFF levels correlated with the percentage of energy derived from the carbohydrates and with energy derived from the dietary fat. Our results suggest that BAFF may play a role in linking the immune status and metabolic response to diet.
Some properties of retract lattices of monounary algebras
Authors: Jakubíková-Studenovská Danica , Pócs Jozef
Published: February 2012

Necessary and sufficient conditions for a connected monounary algebra (A, f), under which the lattice R
∅(A, f) of all retracts of (A, f) (together with ∅) is algebraic, are proved. Simultaneously, all connected monounary algebras in which each retract is a union of completely join-irreducible elements of R
∅(A, f) are characterized. Further, there are described all connected monounary algebras (A, f) such that the lattice R
∅(A, f) is complemented. In this case R
∅(A, f) forms a boolean lattice.
Statistical order convergence in Riesz spaces
Authors: Şençi̇men Celaleddi̇n , Pehli̇van Serpi̇l
Published: February 2012

In this paper, we introduce the concepts of statistical monotone convergence and statistical order convergence in a Riesz space, and establish some basic facts. We show that the statistical order convergence and the statistical convergence in norm need not be equivalent in a normed Riesz space. Finally, we introduce the statistical order boundedness of a sequence in a Riesz space.
Computational Efficiency of Alternative Algorithms for Arterial Offset Optimization
Authors: Day Christopher M. , Bullock Darcy M.
Published: February 2012

This paper compares the performance of several algorithms for offset optimization. A case study of a five-intersection arterial is presented. Cyclic probability distributions of vehicle arrivals and the probability of green are used to characterize traffic conditions under alternative offsets. Five algorithms for offset optimization were selected for comparison: quasi-exhaustive search, Monte Carlo selection, genetic algorithms, hill climbing, and the combination method. Each algorithm was evaluated with two alternative objectives: minimize delay and maximize vehicle arrivals on green. The relative performances of the algorithms were characterized by the optimality of the solution that they returned, the number of computations needed to execute the algorithm, and the marginal cost of adding an additional intersection to the system. All five algorithms effectively identified optimal or near-optimal offsets within the solution space. Hill climbing was more efficient than genetic algorithms, but the optimality of the solutions from both types was similar. The combination method found the most optimal offsets, with efficiency similar to that of hill climbing. The combination method is recommended for arterial offset optimization because of its deterministic computational performance for identifying optimized offset timing plans.
Turn Pocket Blockage and Spillback Models
Authors: Reynolds William L. , Rouphail Nagui M. , Zhou Xuesong
Published: February 2012

The development of a macroscopic simulation tool is presented and tested to quantify the effects of short turn pockets on the sustainable service rate of a signalized intersection. Unlike the theoretical signal capacity, the sustainable service rate includes queue interaction effects and is thus influenced by blockage and spillback at the entrance to a short turn pocket. Previous research on the topic has focused either on the probability of spillback from a short turn pocket or the operation of a system with a single approach lane. No macroscopic model currently available has the ability to analyze throughput reductions due to the effects of short turn pockets on a multilane approach. The model described here uses a series of flow and density restrictions on cells of varying sizes on the approach to the intersection. Results, which indicate sensitivity of the model to turn pocket spillback, blockage, saturation flow rate, pocket length, lane utilization, cycle length, phase sequence, phase overlap, permitted phasing, and time-dependent demand, compare favorably with microsimulation. A phase optimization procedure is described to help efficiently allocate green time for a given set of turn pocket lengths and turn movement percentages. Implications of using the model for signal timing applications are discussed, and recommendations are made on additional model enhancements and testing needs.
Improving Safety and Mobility at High-Speed Intersections with Innovations in Sensor Technology
Authors: Sharma Anuj , Bullock Darcy M. , Velipasalar Senem , Casares Mauricio , Schmitz Jacob , Burnett Nathaniel
Published: February 2012

A series of innovations has been made in the vehicle sensors field. Technologies such as IntelliDrive and radar-based smart sensors make it possible to track each vehicle in proximity to an intersection. However, current technologies have limitations, such as lack of robustness, accuracy, or level of penetration. This paper assumes an accurate wide-area detector (WAD), which might be soon available, and highlights the potential benefits that might be derived in safety and efficiency of operations at high-speed intersections from the deployment of the WAD. Two critical areas in which wide-area detection can lead to significant improvements are discussed: (a) location of crash risk on onset of yellow and (b) location of vehicles on onset of yellow. A case study was conducted at an instrumented intersection in Noblesville, Indiana, to estimate potential improvement from the use of an ideally operating WAD and green extension logic for signal control. Findings revealed that the replacement of the single loop detector sensor with a WAD sensor would lead to an additional 1.4 vehicles being served per lane on the cross street per unit vehicle provided with dilemma zone protection on the highspeed approach. Results also showed that speed traps should be used only after accounting for the trade-off between safety and efficiency and the traffic control logic. When speed traps were designed with generic dilemma zone boundaries at the Noblesville site, the dilemma zone protection was provided only 57% of the time because vehicles accelerated or decelerated after passing the speed trap.
Distribution and Assignment of Compulsory and Discretionary Traffic
Authors: Chu You-Lian
Published: February 2012

This paper presents the development of a combined equilibrium model for the simultaneous prediction of the destination and route choices that face suburban or rural automobile travelers. Destination choice is given by a dogit model to take into account the travel behavior of compulsory (work) and discretionary (nonwork) trips. A logit-based route-choice model was employed, with a stochastic user equilibrium principle, to develop route flows between each origin–destination pair. The natural logarithm of the denominator of the logit route-choice model (i.e., log-sum) was computed and fed back into the destination-choice step. Under this iterative process, the destination choice for discretionary trips responded to changing travel-cost conditions, whereas the destination choice for compulsory trips remained fixed in the study time period. The proposed combined destination- and route-choice (CDR) model can itself be reformulated as an equivalent convex programming problem with linear constraints, a great advantage from a computational perspective. The CDR model was applied empirically to a county-level network in New Jersey. The results encourage further applications of the CDR model to large-scale networks.
Comparison of Multiobjective Evolutionary Algorithms for Optimization of Externalities by Using Dynamic Traffic Management Measures
Authors: Wismans Luc J. J. , Van Berkum Eric. C. , Bliemer Michiel C. J.
Published: February 2012

The externalities of traffic are increasingly important for policy decisions related to design of a road network. Optimization of externalities with dynamic traffic management measures influencing the supply of infrastructure is a multiobjective network design problem, which in turn is a bi-level optimization problem. The presence of conflicting objectives makes the solution to the optimization problem a challenge. Evolutionary multiobjective algorithms have proved successful in solving such problems. However, like all optimization methods, these are subject to the no-free-lunch theorem. Therefore, this paper compares the nondominated sorting genetic algorithm II (NSGA-II), the strength Pareto evolutionary algorithm 2 (SPEA2), and the strength Pareto evolutionary algorithm 2+ (SPEA2+) to find a Pareto optimal solution set for this problem. Because incorporation of traffic dynamics is important, the lower level should be solved through a dynamic traffic assignment model, which increases needed CPU time. Therefore, algorithm performance is compared within a certain budget. The approaches are compared in a numerical experiment through different metrics. The externalities optimized are noise, climate, and congestion. The results show that climate and congestion are aligned and that both are opposed to noise in the case study. On average, SPEA2+ outperforms SPEA2 in this problem on all used measures. Results of NSGA-II and SPEA2+ are inconclusive. A larger population results on average in a larger space coverage, while a smaller population results in higher performance on spacing and diversity. Most performance measures are relatively insensitive for the mutation rate.
Field Evaluation of Automatic Pedestrian Detectors in Cold Temperatures
Authors: Montufar Jeannette , Foord Jonathan
Published: February 2012

The equitable accommodation of pedestrians is critical in transportation engineering and planning. Major concerns over the use of push buttons to activate pedestrian signals have been raised in many jurisdictions because elderly pedestrians and certain physically impaired pedestrians experience difficulty using push buttons, even when the push button is placed in a convenient and standard location. This paper presents the results of an analysis of the performance of three commercially available curbside automatic pedestrian detectors (APD)—a passive infrared and stereovision curbside detector, a passive infrared curbside detector, and a microwave detector—in the field as a function of weather, temperature, and temporal variations at signalized intersections during the winter months at temperatures ranging from −34°C (−29°F) to 0°C (32°F). The results were classified according to detector sensitivity, which referred to the percentage of pedestrian crossings detected successfully, and detector selectivity, which referred to the percentage of activations triggered by actual pedestrians, instead of false activations from vehicle movement, trees in the wind, or other causes. From a sample of 8,225 detections at two sites, the results revealed that the three APDs were generally sensitive at sending valid pedestrian calls, but selectivity rates remained less than 50%. Under all conditions and of all APDs analyzed, the infrared detector consistently had the highest sensitivity and lowest selectivity; the infrared–video detector had the second-highest sensitivity and the highest selectivity; and the microwave detector had the lowest sensitivity and the second-highest selectivity.
Sign Visibility for Pedestrians Assessed with Agent-Based Simulation
Authors: Nassar Khaled
Published: February 2012

As cities and urban centers become bigger and as building spaces become larger, the need for correctly designed and located signage becomes paramount. The geometry of these urban or architectural spaces is becoming more complex because of traffic flow in multiple directions, several obstructions, and nonconvex spaces. The complex architecture makes the determination of the optimal locations for the placement of signs in these spaces more difficult. This paper provides a framework for the rational location of signs in public spaces to increase their detectability through the consideration of the geometric configuration of the space, the occupant or pedestrian travel flow patterns, the locations of obstructions, the legibility distance, and the sign design. The framework used an agent-based simulation model, in which occupants or pedestrians were modeled as intelligent agents that moved in the space according to predefined traffic patterns. The social force model was used to simulate the microscopic movement behavior of the agents in the space. In addition, the perceptual attention of the pedestrians was modeled by consideration of the field of view of the agents as well as sign location and design. A computer simulation model was developed and tested in a real-life case study to demonstrate the applicability of the model. The research presented here should be of interest to practicing architects and engineers as well as researchers.
Effectiveness of Signal-Based Countermeasures for Pedestrian Safety: Findings from Pilot Study
Authors: Vasudevan Vinod , Pulugurtha Srinivas S. , Nambisan Shashi S. , Dangeti Mukund R.
Published: February 2012

This paper summarizes findings from a pilot study to evaluate the effectiveness of signal-based countermeasures that may reduce conflicts and crashes and thereby enhance pedestrian safety. The countermeasures are pedestrian and driver oriented and consist of pedestrian-activated call buttons that light up to confirm activation, pedestrian countdown signals with animated eyes, and pedestrian-activated flashing yellow signals. The evaluations are based on field observations of pedestrian and driver behaviors before and after installation of the countermeasures at three sites (two intersections and one midblock location) in the Las Vegas, Nevada, metropolitan area. The countermeasures were evaluated with the following measures of effectiveness: pedestrians trapped in the roadway, signal cycles in which the call button was pushed, frequency of signal violation, pedestrians looking for vehicles before beginning to cross, pedestrians beginning their crossings during the “Walk” phase, pedestrians in the crosswalk at the end of the flashing “Don't Walk” phase, pedestrians who look for vehicles before crossing the second half of the street, captured pedestrians, diverted pedestrians (those who had to go out of their way to use the crosswalk or changed their course of action), drivers yielding to pedestrians, driver yielding or stopping distance before the crosswalk, drivers blocking the crosswalk, and drivers who come to a complete stop before making a right turn on red. The results showed improvements in pedestrians’ observational behavior for pedestrian-oriented countermeasures. Driver-oriented signal deployment improved the yielding behaviors of both drivers and pedestrians. These findings could be used to enhance pedestrian safety on arterial roads in other cities with similar demographic characteristics and traffic conditions.
Use of Genetic Algorithm for Phase Optimization at Intersections with Minimization of Vehicle and Pedestrian Delays
Authors: Yang Zengyi , Benekohal Rahim F.
Published: February 2012

The two objectives of this research were to develop a methodology to optimize signal timing at intersections by minimization of delay for both vehicles and pedestrians and to establish guidance for the selection of the pedestrian crossing phase (two-way or scramble) and the length of the “Walk” phase when the scramble crossing pattern was used. An optimization procedure for signal plans was developed for an isolated intersection. The procedure can provide up to four vehicular phases with either the two-way or scramble pedestrian crossing phase. Genetic algorithms were used to find suitable signal plans because of the existence of a large solution set. Furthermore, the proposed genetic algorithm procedure can generate contour diagrams as selection guides to determine appropriate pedestrian crossing phases at an intersection with different combinations of vehicle volumes and pedestrian volumes. The impacts of relative time values, initial vehicle queues, and geometric designs on the pedestrian phase selection were also determined. According to the contour diagrams, to determine appropriate pedestrian crossing phases, not only do pedestrian volumes and right-turning vehicle volumes need to be taken into account but also through (and left-turning) vehicle volumes should be considered. The scramble crossing reduced delay when the conflicting pedestrian and right-turning vehicle volumes in approaches were high and the through (and left-turning) vehicle volumes in the same approaches were relatively lower. Otherwise, the scramble phase increased delay.
Exploring Your Own Backyard: Measurement of Greenway Use in Cary, North Carolina
Authors: Bush Robert
Published: February 2012

Many cities in the United States are providing opportunities for non-motorized travel by constructing greenways. Little substantial information exists, however, about their use. This paper presents a methodology and the results of an ongoing program to count greenway users within Cary, North Carolina. The intent is to provide a methodological approach that can be reproduced by other jurisdictions that wish to determine their use throughout the year and to add to the body of data on potential usage levels. A walking-count methodology was used: counters walked the length of a designated segment, counted users as they went, and recorded the travel mode and demographic information. This methodology provided a more complete picture of use along the entire length of the segment than a stationary count could provide. During the program's 3 years of existence, 947 checks were made on randomly selected weekends. Because volunteer labor was used, no weekday counts were available. The median number of users per daylight hour was 11.76. Statistically significant differences existed between the median use on segments classified as metro segments, which served the entire community, with 46.42 users per hour, and neighborhood segments, which served the immediate vicinity, with 8.40 users per hour. For the entire system, the plurality of users was walkers (38%), followed by bicyclists (25%), runners (16%), and dog walkers (15%). Metro segments showed greater use by bicyclists and runners, and neighborhood segments showed greater use by walkers with or without a pet. Temperature was found to have a significant effect on use, whereas the time period did not.
Inconsistencies of Ordered and Unordered Probability Models for Pedestrian Injury Severity
Authors: Kwigizile Valerian , Sando Thobias , Chimba Deo
Published: February 2012

Data on crashes between a single vehicle and a pedestrian recorded in Florida from 2004 to 2008 were used to identify the factors affecting the level of pedestrian injury severity, given that an accident had occurred and to assess the consistency of the ordered (ordered probit) and the unordered (multinomial logit) models. Both models were applied to the same data set. For the impact of individual variables on the levels of pedestrian injury severity to be discerned for the ordered probit and the multinomial logit models, the marginal effects were calculated. The results of a comparison of the two models indicated that the two models were consistent when they suggested the impact of individual factors on the lowest and the highest levels of injury severity (no injury or a possible injury and fatal injury, respectively) but suggested opposing impacts for some factors on intermediate levels of injury severity (nonincapacitating and incapacitating injuries). Such an inconsistency has implications for pedestrian safety measures and policies that are based on the models. Therefore, cautious selection of ordered and unordered probability models should be exercised with the use of a trade-off between recognition of the ordered pedestrian injury outcomes and loss of the flexibility in specification offered by unordered probability models. However, because the models are consistent for determination of the impact of variables on the lowest and the highest outcomes, pedestrian safety measures and policies should be derived on the basis of these outcomes.
Logistic Regression Model of Risk of Fatality in Vehicle–Pedestrian Crashes on National Highways in Bangladesh
Authors: Sarkar Sudipta , Tay Richard , Hunt John Douglas
Published: February 2012

Pedestrian fatalities on national highways in Bangladesh account for about 47% of all pedestrian fatalities; therefore, it is important to identify the risk factors involved. Binary logistic models were calibrated with crash data from 1998 to 2006 maintained by the Accident Research Institute of Bangladesh to identify the factors associated with the probability of a fatal outcome. The results showed that the involvement of elderly pedestrians (individuals older than 55 years of age) and young pedestrians (individuals younger than 15 years of age) increased the likelihood of a fatality. A higher risk of fatality was also seen for pedestrians who crossed the road than for those who walked along the edges of the road. Pedestrian collisions with trucks, buses, baby taxis or tempos (auto rickshaws), and tractors had a higher risk of a fatality than collisions with cars. Crashes occurring at locations with no traffic control, stop control, and pedestrian crossings had a higher risk of a fatality than those occurring at locations with traffic signals or police control. Finally, collisions during the rainy season had a higher probability of a fatality. In addition, the influences of implicit attributes on the trend for the risk of a pedestrian injury, temporal confounding, and interaction effects were considered and were incorporated progressively into the model. A trend toward a slight increase in the risk of a pedestrian fatality was found when the model controlled for the influences of demographic factors, the road environment, and other risk factors. The identification of these risk factors for pedestrians provides valuable inputs that will assist with the development of a comprehensive pedestrian safety action plan.