bluuebunny/crossref_metadata_2025 huggingface dataset:
Consensus Building in AHP-Group Decision Making: A Bayesian Approach
Authors: Altuzarra Alfredo , Moreno-Jiménez José María , Salvador Manuel
Published: December 2010

This paper examines consensus building in AHP-group decision making from a Bayesian perspective. In accordance with the multicriteria procedural rationality paradigm, the methodology employed in this study permits the automatic identification, in a local context, of “agreement” and “disagreement” zones among the actors involved. This approach is based on the analysis of the pairwise comparison matrices provided by the actors themselves. In addition, the study integrates the attitudes of the actors implicated in the decision-making process and puts forward a number of semiautomatic initiatives for establishing consensus. This information is given to the actors as the first step in the negotiation processes. The knowledge obtained will be incorporated into the system via the learning process developed during the resolution of the problem. The proposed methodology, valid for the analysis of incomplete or imprecise pairwise comparison matrices, is illustrated by an example.
A Model of ICU Bumping
Authors: Dobson Gregory , Lee Hsiao-Hui , Pinker Edieal
Published: December 2010

Many intensive care units (ICUs) face overcrowding. One response to this overcrowding is to bump ICU patients to other departments of the hospital to make room for new patient arrivals. Such bumping clearly has the potential to reduce quality of care. In this paper we develop a stochastic model of a single ICU with patient bumping. The purpose of this model is to enable planners to predict performance, in terms of bumping, under differing arrival patterns and capacity. We develop a Markov chain model and a new aggregation-disaggregation algorithm for this problem that enables us to keep track of the time in system for each patient despite the high dimensionality of the problem. Our approach allows for more accurate modeling of the system than previous work that assumed an exponential distribution for length of stay (LOS). We also demonstrate the superior computational efficiency of our approach over the Gauss-Seidel iterative method for solving the Markov chain. Finally, we use the model to explore how different surgery schedules influence bumping rates.
TECHNICAL NOTE—Optimal Product Pricing and Component Production Quantities for an Assembly System Under Supply Uncertainty
Authors: Pan Wenting , So Kut C.
Published: December 2010

We consider an assemble-to-order system where one of the components faces uncertainty in the supply process in which the actual available quantity is equal to some random fraction of the production quantity. Demand is assumed to be price-dependent. We analyze how the supply uncertainty of one component affects the product pricing and production quantities of all the components under the assembly structure. We show that it is profitable for the firm to assemble the product only if the product price exceeds a certain threshold. This price threshold increases as the unit cost of each component or the degree of variability of the supply reliability distribution increases, but it is independent of the underlying demand function and demand distribution. Also, the optimal product price decreases as supply uncertainty decreases. We further show that under deterministic demand, the components can be managed independently such that the production quantity or unit cost of the component with supply uncertainty does not affect the optimal production quantity of the other components, as long as it is profitable to assemble the product. However, when demand is stochastic, the optimal production quantity of each component depends on the supply reliability distribution as well as the unit costs of the other components. For a fixed product price, the optimal production quantities of the components are smaller when the unit product price is low, and they are higher when the unit product price is high as compared to the case with no supply uncertainty.
Optimal Breast Biopsy Decision-Making Based on Mammographic Features and Demographic Factors
Authors: Chhatwal Jagpreet , Alagoz Oguzhan , Burnside Elizabeth S.
Published: December 2010

Breast cancer is the most common non-skin cancer affecting women in the United States, where every year more than 20 million mammograms are performed. Breast biopsy is commonly performed on the suspicious findings on mammograms to confirm the presence of cancer. Currently, 700,000 biopsies are performed annually in the U.S.; 55%–85% of these biopsies ultimately are found to be benign breast lesions, resulting in unnecessary treatments, patient anxiety, and expenditures. This paper addresses the decision problem faced by radiologists: When should a woman be sent for biopsy based on her mammographic features and demographic factors? This problem is formulated as a finite-horizon discrete-time Markov decision process. The optimal policy of our model shows that the decision to biopsy should take the age of patient into account; particularly, an older patient's risk threshold for biopsy should be higher than that of a younger patient. When applied to the clinical data, our model outperforms radiologists in the biopsy decision-making problem. This study also derives structural properties of the model, including sufficiency conditions that ensure the existence of a control-limit type policy and nondecreasing control-limits with age.
Attention to Attention
Authors: Ocasio William
Published: December 2010

Organizational theory and research has increased attention to the determinants and consequences of attention in organizations. Attention is not, however, a unitary concept but is used differently in various metatheories: the behavioral theory of the firm, managerial cognition, issue selling, attention-based view, and ecology. At the level of the brain, neuroscientists have identified three varieties of attention: selective attention, executive attention, and vigilance. Attention is shaped by both top-down (i.e., schema-driven) and bottom-up (i.e., stimulus-driven) processes. Inspired by neuroscience research, I classify and compare three varieties of attention studied in organization science: attentional perspective (top-down), attentional engagement (combining top-down and bottom-up executive attention and vigilance), and attentional selection (the outcome of attentional processes). Based on research findings, I develop five propositions on how the varieties of attention in organization provide a theoretical alternative to theories of structural determinism or strategic choice, with a particular focus on the role of attention in explaining organizational adaptation and change.
Parental Satisfaction with Children's Primary Dental Care in Valencia, Spain
Authors: Llena Carmen , Clemente Gonzalo , Forner Leopoldo
Published: December 2010

Aim

To evaluate parents’ satisfaction with the dental care that their children received in a primary dental care unit in Valencia, Spain.

Methods

A cross-sectional study was designed. Parents were given a self-administered questionnaire with questions on accessibility, information received from the dentist and hygienist, staff interest in their child, dentist's and hygienist's apparent professional competence, handling of the child's behaviour, cleanliness of the office (surgery), overall parent satisfaction, parent's and child's age, and parental educational level. The chi-square test was used to assess overall parental satisfaction and the other study variables. For the multivariant study, CHAID (CHi-square Automatic Interaction Detection) analysis was used.

Results

Out of a possible 400 respondents, 389 completed the questionnaire, of whom 384 completed it in full. The variables significantly associated with overall parental satisfaction were waiting time before the consultation, cleanliness of the surgery, the manner in which appointments were made, staff attitude with regard to helping, listening and understanding, the dentist's and hygienist's professionalism, handling of the child's behaviour, and information given by the dentist and hygienist. In logistic regression, the aspects that significantly explained parental satisfaction were the professionals’ apparent competence, the information given by the dentist, staff interest in their child, and the handling of the child's behaviour.

Conclusion

The parents who took part in this study were satisfied with the care that their children received, mainly with aspects related to professional competence and information provided.
Factors that Dentists use to Decide Whether or Not to Render a Patient Edentulous
Authors: Pearce Mark , Gedling Catherine , Whittle Gary , Robinson Janet , Whitehead Hilary
Published: December 2010

Aims

To investigate the factors that dentists use to decide whether or not to make a patient edentulous.

Method

A previous qualitative investigation identified factors that dentists would consider when making a patient edentulous. Using this information, a questionnaire was created and sent to all dentists practising in East Lancashire, asking them whether these factors would make them more or less likely to extract all remaining teeth for a patient.

Results

123 usable questionnaires were returned from 187 dentists, a response rate of 67%. Dentists felt that clinical factors such as poor periodontal health and active decay were more likely to make them extract all remaining teeth. They were also concerned about retention and were keen to retain strategic teeth. Apart from their acknowledgment of the need to comply with the patient's wish to keep his or her teeth, the dentists had a neutral opinion of other factors such as poor health or their personal attitude to treatment. On average, respondents were rendering just over three patients per year edentulous.

Conclusion

In this group of dentists, the key clinical factors that were considered when they decided whether or not to render a patient edentulous were periodontal disease, caries, and the attitude of the patient to tooth loss. Relatively few patients were rendered edentulous each year and if this pattern is common elsewhere in the United Kingdom, it may lead to a lack of skills within the dental workforce in managing patients’ transition from dentate to edentulous.
Autism Spectrum Disorders: Clinical Aspects
Authors: Ivo Paclt  , Anna Strunecka
Published: December 2010

Autism spectrum disorders (ASD) are a group of related neurodevelopmental disorders, which includes autism (autistic disorder), Asperger syndrome, Rett syndrome, pervasive developmental disorder-not-otherwise specified (PDD-NOS), and childhood disintegrative disorder (CDD). This chapter provides the review of recent knowledge about clinical symptoms and criteria for diagnosis of heterogeneous symptoms of ASD. An alarming increase in the prevalence of ASD is of great concern to practicing pediatricians and psychiatrists. Some people attribute the increases over time in the frequency of ASD to factors such as new administrative classifications, changing diagnostic criteria, and heightened awareness. It is evident, that no single factor or a simple explanation can account for the increase. ASD are highly genetic and multifactorial, with many risk factors acting together. There is no therapy of the core symptoms of ASD at present. Several studies suggest that 50-75% of children with ASD are using complementary alternative medicine. Families and clinicians need access to theoretical and clinical evidence to assist them in the choice of therapies.
The Cerebellum in Autism Spectrum Disorders
Authors: Russell L. Blaylock
Published: December 2010

The cerebellum is the most commonly affected part of the brain in autistic spectrum disorders (ASDs). The histopathological changes strongly indicate selected damage to particular cell groups and lobules of the cerebellum rather than diffuse injury. A number of studies have shown injury and abnormal development of the vermis of the cerebellum, with a predominance of neuronal loss among Purkinje cells and granule cells. In addition, one see abnormal pathway development indicating intrauterine damage or damage occurring during the early postnatal period. Several studies have shown abnormalities of glutamate receptors (GluRs) of various kinds, including metabotropic GluRs (mGluRs). In this chapter, I review the histopathologic findings within the ASD cerebellum and demonstrate evidence for immunoexcitotoxicity affecting cerebellar neurodevelopment as well as evidence for early neurodegeneration. Newer studies have shown that the cerebellum may have significant cognitive and higher cortical functions, either by way of its connections to prefrontal-limbic areas or more indirect pathways.
Dysregulation of Glutamatergic Neurotransmission in Autism Spectrum Disorders
Authors: Anna Strunecka
Published: December 2010

Despite the great number of observations being made concerning cellular and molecular dysfunctions associated with autism spectrum disorders (ASD), an integrative and unifying mechanism to explain the heterogeneous symptoms and etiology of ASD has not been proposed in the major scientific literature. We offer the explanation of potential etiology of ASD as dysregulation of glutamatergic neurotransmission with underlying interactions between chronic microglial activation and the excitotoxic cascade playing the central role. This chapter summarizes current knowledge of the structural and functional diversity of glutamate receptors (GluRs) and excitatory amino acid transporters. Recent research of the autism genome also supports the view that abnormalities in genes connected with glutamate neurotransmission and disturbed regulation of glutamate pathways may be directly involved in ASD. We further suggest that the increasing prevalence of ASD during the last decades might reflect the synergistic action of an increased burden of new excitotoxic factors. In this chapter we discuss the effects of dietary excitatory amino acids, mainly glutamate and aspartate, which could exacerbate the pathological and clinical symptoms of ASD. The mechanism of excitotoxicity is the topic of the next chapter.
Immune Dysfunction in Autism Spectrum Disorders
Authors: Russell L. Blaylock
Published: December 2010

A great number of studies have been done examining immune function in children with autism spectrum disorders (ASD). Most of these studies have demonstrated immune dysfunction, especially involving cellular immunity. Important to the immunoexcitotoxicity hypothesis is the finding that macrophages and lymphocytes from ASD children have been shown to demonstrate an amplified release of pro-inflammatory cytokines with stimulation, especially in those having gastrointestinal (GI) symptoms. Because of the intimate connection between the gut and brain, hyperimmune responses from the gut, vial vagal afferents, can rapidly activate brain microglia, leading to an exaggerated innate immune response within the brain. It has also been shown that ASD children often react to food peptides, such as gliadin, gluten and casein as well as a number of bacterial and fungal antigens, all of which can exaggerate immunoexcitotoxicity. The finding of cross-reacting food antigen with brain components also indicates the presence of bystander damage and would trigger immunoexcitotoxicity as well.
Biochemical Changes in ASD
Authors: Anna Strunecka
Published: December 2010

Metabolic dysfunctions have not been extensively studied in ASD despite the fact that chronic biochemical imbalance is often a primary factor in the development of several neurological diseases. Substantial percentages of autistic patients display peripheral markers of mitochondrial energy metabolism dysfunction, such as elevated lactate and alanine levels in blood and serum carnitine deficiency. We assess the reported biochemical changes in the blood and evidence based on the exploration of brain imaging studies. Even though alterations in mitochondrial and cellular energy metabolism are not specific for ASD, they indicate the potential ethiopathological events. Evidence from several laboratories similarly indicates that biomarkers of oxidative stress may be increased in some autistic children. One of the best documented biochemical changes in ASD is a decrease in cellular glutathione (GSH) levels, a major intracellular antioxidant, and an increase in oxidized glutathione (GSSG). Alterations in methionine -homocysteine cycle have been studied in details in ASD. Significant changes in transmethylation and transsulfuration metabolites in plasma from autistic children were reported. The new finding indicates a significant decrease in methylation capacity and redox potential. Metabolic and mitochondrial defects may have toxic effects on brain cells, causing neuronal loss and altered modulation of neurotransmission systems. The observations of biochemical changes thus further support that the antioxidant therapy and supplementation with some vitamins could prevent and restore the energy metabolism of individuals with ASD. This chapter brings evidence of the impact of observed biochemical changes in ASD for potential amelioration of ASD symptoms and for evidence-based therapy.
Addendum. Autism: Is It All in the Head?
Authors: Mark A. Hyman
Published: December 2010

Mark A. Hyman, MD, is Chairman of the Institute for Functional Medicine. Anna Strunecka asked him to provide his Editorial [1] as an addendum of this eBook. Autism is described as a hologram for chronic disease; an extreme manifestation of disruptions in normal biology that exist in varying degrees in most chronic illness. Autism is a complex, multi-system disorder rooted in a series of toxic, infectious, and allergic insults. Through the story of one boy, the author looked carefully at the few biological systems manifesting as the clinical features of autism: gut and immune dysfunction, nutritional deficiencies, toxicity and impaired detoxification, mitochondrial dysfunction and oxidative stress, and genetic polymorphisms that set the stage for biochemical train wrecks. In autistic children, the results of testing often reveal results that show deviations orders of magnitude higher than in other chronic illness, but nonetheless, the same patterns exist. The lessons learned from the dissection of the functional causes and mechanisms of autism can illuminate the path for whole system medicine and clinical research and the potential for it to address the global crisis of chronic disease.
CIM-EARTH: Framework and Case Study
Authors: Elliott Joshua , Foster Ian , Judd Kenneth , Moyer Elisabeth , Munson Todd
Published: December 2010

General equilibrium models have been used for decades to obtain insights into the economic implications of policies and decisions. Despite successes, however, these economic models have substantive limitations. Many of these limitations are due to computational and methodological constraints that can be overcome by leveraging recent advances in computer architecture, numerical methods, and economics research. Motivated by these considerations, we are developing a new modeling framework: the Community Integrated Model of Economic and Resource Trajectories for Humankind (CIM-EARTH). In this paper, we describe the key features of the CIM-EARTH framework and initial implementation, detail the model instance we use for studying the impacts of a carbon tax on international trade and the sensitivity of these impacts to assumptions on the rate of change in energy efficiency and labor productivity, and present results on the extent to which carbon leakage limits global reductions in emissions for some policy scenarios.
The European Company (SE): Practical Failure or Model for Other Supranational Company Types?
Authors: Schmidt Jessica
Published: December 2010

Since 2004, European undertakings have had the possibility to opt for a supranational type of company: The European Company or Societas Europaea (SE). A considerable  though overall not huge  number of enterprises have already availed themselves of this new opportunity, including, inter alia, famous names like the German industry giants Allianz SE, BASF SE, and Porsche Automobil Holding SE or the French reinsurer SCOR SE. The paper will first provide an overview of the salient features of this new supranational European type of company. The primary focus will be on the most important advantages (e.g., cross-border transfer of seat and restructuring, flexibility with respect to internal structure, European corporate identity) and disadvantages (e.g., rather complex legal framework, no special tax provisions) of using this supranational corporate vehicle, both from a legal and an economic point of view and illustrating the respective aspects by way of examples from the practical experience gained with the SE so far. Based on this, the paper will then examine whether the SE has really turned out to be the practical failure that many predicted or whether it could actually serve as a model for other supranational company types ? not only on the European level, but also on a wider international or even global level, especially for Asian countries as well.
Law and Availability of Credit: Evidence from India
Authors: Rathinam Francis Xavier , Raja Angara Viswasundara
Published: December 2010

Law and Finance literature shows that effective creditor and investor protection leads to vibrant financial markets. This paper hypothesizes that supporting laws that lead to swift enforcement and reduce the cost of availing legal services would help implement the law effectively. The causal relationship between the procedural law and credit in India is explored using both macro and micro econometric techniques. Using a newly constructed time series index of procedural law innovations in India, this paper tries to identify the direction of causality and also explore the possible channels of impact in the Indian context. The results suggest that there is a long run causal relationship between law and finance, and the channel of impact is debt accumulation rather than total factor productivity. At a micro-level, using the staggered introduction of the Debt Recovery Tribunals (DRTs), a fast track court for financial disputes involving banks, we show that the procedural law innovation in India has resulted in higher disbursal of loans to the private sector by the banks.
Comparison of Near-Patient Capillary Glucose Measurement and a Risk Assessment Questionnaire in Screening for Type 2 Diabetes in a High-Risk Population in Rural India
Authors: Ritchie Georgia E. , Kengne Andre Pascal , Joshi Rohina , Chow Clara , Neal Bruce , Patel Anushka , Zoungas Sophia
Published: December 2010

OBJECTIVE

To assess the utility of a point-of-care (POC) capillary blood glucose measurement as compared with routine clinical parameters in predicting undiagnosed diabetes in a low-resource rural India setting.

RESEARCH DESIGN AND METHODS

Nine hundred and ninety-four participants aged >30 years and stratified by age and sex were randomly selected from 20 villages in India. A clinical questionnaire, sampling for laboratory venous fasting plasma glucose (FPG), and POC capillary blood glucose assay were performed simultaneously. Diabetes diagnosis was based on the World Health Organization (WHO) definition using FPG. The capacity of the POC glucose to predict the presence of diabetes was assessed and compared with the questionnaire using area under the receiver operating characteristic curves (AUCs).

RESULTS

The AUC for POC glucose alone in predicting diabetes was 0.869 (95% CI 0.810–0.929). This was significantly better (P < 0.001 for AUC comparison) than the models based upon clinical variables alone (AUC for the best clinical model including age, BMI, hypertension, waist circumference: 0.694 [95% CI 0.621–0.766]). POC glucose appropriately reclassified the risk of up to one-third of participants ranked according to the clinical models. Adding the clinical variables to the POC glucose assay did not significantly improve the discriminatory capability beyond that achieved with the POC glucose measurement alone (all P > 0.37).

CONCLUSIONS

POC glucose testing appears to be a simple and reliable tool for identifying undiagnosed diabetes in a high-risk, resource-poor rural population. However, studies evaluating the cost effectiveness of introducing POC glucose testing are needed prior to widespread implementation.
Peripheral myelin protein-22 is expressed in CNS myelin
Authors: Gasperi Rita , Sosa Miguel , Naumowicz Zuzanna , Hof Patrick , Notterpek Lucia , Davis Kenneth , Buxbaum Joseph , Elder Gregory
Published: December 2010

Myelin abnormalities exist in schizophrenia leading to the hypothesis that oligodendrocyte dysfunction plays a role in the pathophysiology of the disease. The expression of the mRNA for the peripheral myelin protein-22 (PMP-22) is decreased in schizophrenia and recent genetic evidence suggests a link between PMP-22 and schizophrenia. While PMP-22 mRNA is found in both rodent and human brain it has been generally thought that no protein expression occurs. Here we show that PMP-22 protein is present in myelin isolated from adult mouse and human brain. These results suggest that PMP-22 protein likely plays a role in the maintenance and function of central nervous system (CNS) myelin and provide an explanation for why altered PMP-22 expression may be pathophysiologically relevant in a CNS disorder such as schizophrenia.
Sensory-memory-based change detection in face stimuli
Authors: Susac Ana , Ilmoniemi Risto , Supek Selma
Published: December 2010

Detection of a change in face is a socially important skill. Both event-related potential (ERP) and magnetoencephalographic (MEG) measurements were conducted using face stimuli presented in an oddball paradigm to investigate detection of a change in face identity and facial expression. In condition 1, a nontarget deviant neutral face was presented among standard happy faces. In condition 2, the same deviant neutral face was presented with a standard neutral face of another person. The task in both conditions was silent counting of a second deviant (face with glasses). Non-target deviants elicited more negative ERP and corresponding MEG responses than standards in both conditions. This negativity was strongest at lateral posterior channels around 280 ms. Responses to the same deviant neutral face differed in two conditions. Deviance-related negativity resembled auditory mismatch negativity (MMN). Different responses to the same deviant in the two conditions suggest the existence of a sensory-memory trace for the standard to which the deviant was compared.
Acute adaptive responses of central sensorimotor neurons after spinal cord injury
Authors: Thompson Kevin , DiBona Victoria , Dubey Aditi , Crockett David , Rasin Mladen-Roko
Published: December 2010

Spinal cord injury (SCI) can be a lifelong, devastating condition for both the patient and the caregiver, with a daunting incidence rate. Still, there are only limited available therapies and the effectiveness of precise regeneration within the central nervous system is minimal throughout postnatal life. Recently, improved regeneration after SCI was seen by manipulating a pathway in sensorimotor neocortices that is involved in phosphorylation of an RNA binding protein (RBP) required for mRNA translation, the Eukaryotic translation initiation factor 4E (eIF4E). Our data identifies rapid molecular alterations of eIF4E in the sensorimotor neocortices 1 and 3 days after a lateral hemisection SCI, used as a model for Brown-Séquard syndrome. The function of an RBP depends on both its distribution sites within the cell and its phosphorylation states. Indeed, we found both to be affected after SCI. There was a distinct subcellular redistribution of eIF4E and phosphorylated-eIF4E was reduced, indicating that the eIF4E’s translation was disrupted. Upon identification and analysis of the mRNA cargo of eIF4E in uninjured sensorimotor neocortices, we found that eIF4E binds both Importin-13 (Ipo13) and Parvalbumin (Pv) mRNAs, indicating a role in their translation. Remarkably, eIF4E’s interaction with both Ipo13 and Pv mRNAs was disrupted 1 and 3 days after SCI, despite preservation of total Ipo13 and Pv mRNA levels. Finally, we detected a selective loss of expression of both IPO13 and PV proteins in projection neurons of sensorimotor neocortices, as well as their disrupted dendritic polarity. Since IPO13 is predominantly expressed in neocortical projection neurons and PV in a subset of neocortical interneurons, these data suggest a strong acute effect of SCI on neocortical microcircuitry. Taken together, these data indicate that neocortical eIF4E and a subset of mRNAs may be rapidly recruited to translational machinery after SCI to promote adaptive regeneration response of sensorimotor neurons.
Treatment strategies for spinal muscular atrophy
Authors: Fuller Heidi , Barišić Marija , Šešo-Šimić Đurđica , Špeljko Tea , Morris Glenn , Šimić Goran
Published: December 2010

Progress in understanding the genetic basis and pathophysiology of spinal muscular atrophy (SMA), along with continuous efforts in finding a way to increase survival motor neuron (SMN) protein levels have resulted in several strategies that have been proposed as potential directions for efficient drug development. Here we provide an overview on the current status of the following approaches: 1) activation of SMN2 gene and increasing full length SMN2 transcript level, 2) modulating SMN2 splicing, 3) stabilizing SMN mRNA and SMN protein, 4) development of neurotrophic, neuroprotective and anabolic compounds and 5) stem cell and gene therapy. The new preclinical advances warrant a cautious optimism for emergence of an effective treatment in the very near future.
Modeling the Spatial Impacts of Public Transport on Traffic Congestion Relief in Melbourne, Australia
Authors: Aftabuzzaman Md , Currie Graham , Sarvi Majid
Published: December 2010

This paper presents experimental modeling that explores the congestion relief effect of transit in Melbourne, Australia. The method adopts a four-step model and assumptions on transit user diversion to auto travel when all or part of the transit system is removed in the a.m. peak. When all transit is removed, diversion to autos causes more than 1,000 additional road links to become congested and increases congestion by 30%. More than 1.3 million additional auto vehicle kilometers of travel occurred and some 97,000 vehicle hours were added under this assumption. Congestion delay increased by more than 150%. Analysis of the separate contributions of transit trips to the central business district (CBD) and greater-CBD areas shows that they contribute to about 40% and 53% of congestion relief in total. When individual transit modes are separately removed, heavy rail use manifests the greatest effects on congestion relief across all suburbs (inner, middle, and outer). Bus effects are second in middle and outer Melbourne, with similar effects to rail use in outer Melbourne. Tram use shows little effect in outer suburbs, but it is significant in inner areas. The greatest percentage change in congestion measures (vehicle hours/delay vehicle hours) is observed in inner Melbourne. However, absolute changes in measures are substantially higher in middle and outer Melbourne, as a result of the bigger spatial scale of these areas. Overall findings increase the understanding of how transit acts to make cities perform more efficiently. An important outcome is the wider non-CBD-based effects on congestion relief, challenging the traditional view that transit and its effect on congestion is an issue only for central cities.
Is Light Rail More Attractive to users than bus Transit?: Arguments Based on Cognition and Rational Choice
Authors: Scherer Milena
Published: December 2010

Decision making for a new light rail system is based on a demand forecast and the additional benefits expected to come along with rail transit. Recent light rail implementations have shown that the demand forecast was often inaccurate. The supposition is that the attraction of light rail, compared with bus systems, has been misjudged. This paper presents arguments on this bias based on a literature review of cognitive approaches and rational choices, with a focus on Europe and North America. The higher attraction of light rail for users is most likely because of four impact groups. The first of these is the attention-capturing factors, such as new and modern vehicles, special design, visibility of route (e.g., tracks, bus lanes), and media presence during the evaluation and construction process; these factors contribute to the memory representation and perception of transit systems. The second is the perceived attributes of transit systems, especially qualitative factors of reliability and ride comfort, which are highly associated with light rail systems. The third, neighborhood characteristics of areas served with a specific transit mode, were found to contribute to the perception and valuation of this transit mode. And last, following the theory of induced demand, the higher capacity provided by light rail vehicles compared with buses can affect ridership. It was found that cognitive approaches contributed to the explanation of the potential preference for light rail. These approaches help to clarify why demand is expected to differ, especially in situations in which light rail and buses provide similar service characteristics in regard to availability.
Regional and Modal Variability in Effects of Gasoline Prices on U.S. Transit Ridership
Authors: Haire Ashley R. , Machemehl Randy B.
Published: December 2010

Previous research has shown a relationship between gasoline price and public transportation use. Although the magnitude, direction, and volatility of this relationship vary by mode, location, and system size, there can be no doubt that recent fuel price growth and fluctuation have affected most U.S. transit systems. The research presented here explores the relationship between transit ridership and fuel price, among other operational and external factors. This investigation found that after seasonal effects were removed from the ridership data series for 254 transit systems, the effect of gasoline price on bus patronage varies regionally, with the North Central and Midwest sections of the nation displaying trends that oppose conventional wisdom and differ from the rest of the country. Plausible reasons underlying these trends, including the regional effect of alternative fuels such as E85, are hypothesized and elaborated on by using federal data on ethanol availability and consumption.
Monocentric City with Discrete Transit Stations
Authors: Kilani Moez , Leurent Fabien , de Palma André
Published: December 2010

The monocentric model is extended by considering a discrete number of accessible mass transit stations. Households combine two modes for their daily home-to-work trip: a first mode for terminal access to stations and a second (long-haul) mode that consists of radial mass transit axes. The urban equilibrium, that is, city size and household distribution, is derived as a function of the mass transit network and the distribution of land housing capacity. At the urban equilibrium, the land rent peaks at transit stations and decreases with the travel cost from the city center, rather than with the distance to it. Accordingly, the housing lot size increases with the travel cost from the city center. These features distinguish this framework from previous monocentric models. The analysis is based on the assumptions that land owners are absent and the city is open (households’ level of utility is given and the population size is endogenous). For numerical illustration, the model is calibrated to a selected rail network in the Paris area. A sensitivity analysis of the urban structure and land use equilibrium is conducted, with key model parameters.
Estimating Transit Accessibility with an Alternative Method: Evidence from Broward County, Florida
Authors: Alam Bhuiyan Monwar , Thompson Gregory L. , Brown Jeffrey R.
Published: December 2010

Scientists have attempted to measure accessibility in several ways—the gravity-based measure being the most widely used. A typical gravity-based model estimates accessibility on a zonal basis as being a function of the sum of total opportunities weighted by the distance, time, and cost needed to travel from the origin zone to those dispersed opportunities. The model includes a parameter that represents the distance–decay relationship and takes an exponential form. Unfortunately, most scientists have arbitrarily chosen the value of the distance–decay parameter instead of estimating it from field survey data. Also, a typical model does not have any parameter attached to the socioeconomic variables. This study uses distance–decay parameters estimated with the use of survey data in Sacramento County, California, to estimate transit accessibility to jobs in Broward County, Florida. Assuming that transferability of distance–decay parameters is possible from one geographic area to another, it then explores such transferability of parameters from Sacramento County to Broward County by analyzing the spatial distribution of transit accessibility and compares the effectiveness of estimated transit accessibility with the traditional transit accessibility measure—proportion of a geographic unit covered by 1/4-mi buffer from a transit route. Results indicate that accessibility indices estimated by using the method presented in this paper reflect what one would expect in reality—much better than what a simple 1/4-mi transit buffer would produce. The paper explores the fact that the distance–decay parameters estimated in one geographic unit are transferable to another. It advances knowledge of the accessibility measuring method that would help solve long-standing debate on what parameters to use for distance–decay and socioeconomic variables going into the accessibility model. Future research needs to focus on validating such transferability of distance–decay parameters from one study area to another.
Impacts of Bus Rapid Transit Stations on Surrounding Single-Family Home Values: Study of East Busway in Pittsburgh, Pennsylvania
Authors: Perk Victoria , Mugharbel Melissa , Catalá Martin
Published: December 2010

The development of bus rapid transit (BRT) systems is relatively recent in the United States; however, several systems are operating and many more are being planned. More comprehensive understanding is needed of the relationship between land use and BRT, particularly in comparison with other fixed-guideway modes. This paper describes an effort to quantify the impacts of BRT stations on the values of surrounding single-family homes. The hypothesis is that BRT stations have an impact on property value that is commensurate with rail transit projects, considering the level and permanence of services and facilities. To test that hypothesis, a hedonic regression model was used to estimate the impact of distance to a BRT station on the fair market value of single-family homes. Because many BRT systems operating in the United States may be too new to find evidence of capitalization into property values, data from East Busway, in Pittsburgh, Pennsylvania, one of the oldest operating BRT systems in the country, was used. Decreasing marginal effects were found: moving from 101 to 100 ft from a station increases property value approximately $18.90; moving from 1,001 to 1,000 ft increases property value by approximately $2.71. The results shown in this paper are valid only for the data used in Pittsburgh's case. As more BRT systems continue to operate in the United States, this method should be applied to other cities and other types of properties to gain a better understanding of the general impacts of proximity to BRT.
Using Quantitative Methods in Equity and Demographic Analysis to Inform Transit Fare Restructuring Decisions
Authors: Hickey Robert L. , Lu Alex , Reddy Alla
Published: December 2010

New York City Transit (NYCT) and the Metropolitan Transportation Authority have integrated race and income equity considerations into their extensive public outreach processes for fare changes. Responding to FTA civil rights, Title VI, and environmental justice requirements, NYCT developed two quantitative and analytical approaches for forecasting equity impacts of fare restructuring decisions, in place of more traditional origin–destination surveys. The first approach uses standard aggregate fare elasticity models to estimate diversions between different fare classes and ridership losses resulting from fare adjustments. Average farechanges by fare media type are disaggregated with historical farecard usage patterns (consumption data) by subway station and bus route and translated into demographic variables (minority or non-minority and at, below, or above poverty) on the basis of census data. Overall average fare changes are used to analyze equity impacts. A second, more experimental approach identifies user demographics by daily first swipe locations and estimates daily average fares as actually experienced by each passenger by using sequential transactions on discrete farecards. To meet ongoing requirements, methods were developed to analyze impacts separately for peak and off-peak time periods and to demonstrate equity by using statistical tests. Impact analyses results and historical ridership, revenue, and market share data collected by the MetroCard automated fare collection system all inform fare structure design processes, with particular attention devoted to distributing fare increase burdens equitably.
Optimization Methodology of Project Construction Scheduling for Intermodal Terminal Planning Problems
Authors: Wang Zhenbao , Chen Yanyan , Wang Haizhong , Kang Hao , Yu Yue
Published: December 2010

The goal of this paper is to present a methodology to optimize project construction scheduling for intermodal terminal planning problems. To accomplish that goal, an algorithm is developed to optimize dynamically the prioritization for all planned intermodal terminals. Optimized project construction scheduling can mitigate traffic congestion and decrease the total travel time. In addition, it is important to make full use of the intermodal terminals to achieve the maximum benefit with a limited financing plan. Essentially, project construction scheduling for intermodal terminals is intended to determine the optimal sequence of intermodal terminal project construction. This paper presents four concepts: location indicator, volume indicator, node indicator, and general indicator. The general indicator is equal to the weighted sum of the location indicator, volume indicator, and node indicator, and it is the key factor in optimizing project construction scheduling. A case study in Beijing is provided to demonstrate the practicability and feasibility of the proposed method.
Ein Sonderwaldreservat für das Auerhuhn – das Beispiel Amden (Kanton St. Gallen) | A special forest reserve for the capercaillie – the model of Amden (Canton St Gallen)
Authors: Ehrbar Rolf , Bollmann Kurt , Mollet Pierre
Published: December 2010

Due to a national species action plan, in Switzerland the capercaillie (Tetrao urogallus) stands in the center of the forestry measures taken to promote the preservation of biodiversity in mountain forests. Special forest reserves are suitable instruments for the conservation of capercaillie because the consecutive reduction of standing stock is the most important measure to improve the species' habitat quality in Swiss forests. In this article, we describe the ecological conditions, fundamentals and the instruments used to delineate the special forest reserve of Amden (Canton St Gallen, Swiss Pre-Alps) in 2006. Further, we report the planning of the measures and the first experiences with the actions done. The special forest reserve encompasses a national priority area for capercaillie conservation and has a surface of 1772 ha. Forest, particularly high-montane fir-beech forest and high-montane fir-spruce forest, interspersed with many mires and fens, covers 55 percent. For the planning we used an area-wide map of forest stands and one showing habitat suitability. We derived the measures that have to be taken in the near future by comparing the actual and the target state of the forest stands on eleven habitat reference areas. The range of the measures includes thinning for regeneration, the creation of flight and escape aisles, the partial clearing of the proximity of roosting trees, the regulation of young growth in favour of conifers, the planting of silver firs, forest edge improvements, increasing the number of lying logs and pulling down trunks. Until the end of 2009 52 harvests had been done with a volume of 14000 m3, 8 ha of young growth were tended and 3700 young silver firs planted. The procedure has worked well during the first four project years. But only success control regarding the development of habitat quality and the species' population response will show how effective the management concept was. The newly developed principle of habitat reference areas that has been applied for the first time will provide valuable support for such a task ten years after the first measures have been taken.
Membrane Drug Transporters and Chemoresistance in Human Pancreatic Carcinoma
Authors: Hagmann Wolfgang , Faissner Ralf , Schnölzer Martina , Löhr Matthias , Jesnowski Ralf
Published: December 2010

Pancreatic cancer ranks among the tumors most resistant to chemotherapy. Such chemoresistance of tumors can be mediated by various cellular mechanisms including dysregulated apoptosis or ineffective drug concentration at the intracellular target sites. In this review, we highlight recent advances in experimental chemotherapy underlining the role of cellular transporters in drug resistance. Such contribution to the chemoresistant phenotype of tumor cells or tissues can be conferred both by uptake and export transporters, as demonstrated by in vivo and in vitro data. Our studies used human pancreatic carcinoma cells, cells stably transfected with human transporter cDNAs, or cells in which a specific transporter was knocked down by RNA interference. We have previously shown that 5-fluorouracil treatment affects the expression profile of relevant cellular transporters including multidrug resistance proteins (MRPs), and that MRP5 (ABCC5) influences chemoresistance of these tumor cells. Similarly, cell treatment with the nucleoside drug gemcitabine or a combination of chemotherapeutic drugs can variably influence the expression pattern and relative amount of uptake and export transporters in pancreatic carcinoma cells or select for pre-existing subpopulations. In addition, cytotoxicity studies with MRP5-overexpressing or MRP5-silenced cells demonstrate a contribution of MRP5 also to gemcitabine resistance. These data may lead to improved strategies of future chemotherapy regimens using gemcitabine and/or 5-fluorouracil.
Decoding Melanoma Metastasis
Authors: Damsky William E. , Rosenbaum Lara E. , Bosenberg Marcus
Published: December 2010

Metastasis accounts for the vast majority of morbidity and mortality associated with melanoma. Evidence suggests melanoma has a predilection for metastasis to particular organs. Experimental analyses have begun to shed light on the mechanisms regulating melanoma metastasis and organ specificity, but these analyses are complicated by observations of metastatic dormancy and dissemination of melanocytes that are not yet fully malignant. Additionally, tumor extrinsic factors in the microenvironment, both at the site of the primary tumor and the site of metastasis, play important roles in mediating the metastatic process. As metastasis research moves forward, paradigms explaining melanoma metastasis as a step-wise process must also reflect the temporal complexity and heterogeneity in progression of this disease. Genetic drivers of melanoma as well as extrinsic regulators of disease spread, particularly those that mediate metastasis to specific organs, must also be incorporated into newer models of melanoma metastasis.