bluuebunny/crossref_metadata_2025 huggingface dataset:
miRNAs in Cardiac Hypertrophy and Heart Failure
Authors: Wang Zhiguo
Published: November 2012

The aim of this chapter is to introduce the role of miRNAs in the pathological process of cardiac
hypertrophy/heart failure. Cardiovascular disease is among the main causes of morbidity and mortality in
developed countries. In response to stress, the adult heart undergoes remodelling process and hypertrophic growth
to adapt to altered workloads and to compensate for the impaired cardiac function. Pathological hypertrophy
results in loss of cardiac function and is the major predictor of heart failure and sudden death. Recent studies have
established the role of miRNAs in cardiac hypertrophy/heart failure as causal factors or important regulators.
miRNAs are aberrantly expressed in various animal models and in patients with heart failure. The miRNAs
involved in cardiac hypertrophy/heart failure can in general be divided into two categories: anti-hypertrophic and
pro-hypertrophic miRNAs. This chapter introduces the roles of miRNAs in experimental and clinical cardiac
hypertrophy/heart failure. Detailed description is given of the well-studied pro-hypertrophic miRNAs miR-195,
miR-208 and miR-23a, and anti-hypertrophic miRNAs miR-1, miR-133 and miR-9.
miRNAs in Cardiac Arrhythmogenesis
Authors: Wang Zhiguo
Published: November 2012

Cardiomyocytes are excitable cells that can generate and propagate excitations; excitability is a
fundamental characteristic of these cells, which is reflected by action potential, the changes of transmembrane
potential as a function of time, orchestrated by ion channels, transporters, and cellular proteins. The electrical
excitation evoked in muscles must be transformed into mechanical contraction through the so-called excitationcontraction
coupling mechanism, and the proper contraction of cardiac muscles then drives pumping of blood to
the body circulation. Arrhythmias are electrical disturbances that can result in irregular heart beating with
consequent insufficient pumping of blood. Arrhythmias are often lethal, constituting a major cause for cardiac
death, particularly sudden cardiac death, in myocardial infarction and heart failure. Recent studies have led to the
discovery of microRNAs (miRNAs) as a new player in the cardiac excitability by fine-tuning expression of ion
channels, transporters, and cellular proteins, which determines the arrhythmogenicity in many conditions. This
review article will give a comprehensive summary on the data available in the literature. The basics of cardiac
excitability are first introduced, followed by a brief introduction to the basics of miRNAs. Then, studies on
regulation of cardiac excitability by miRNAs are described and analyzed.
miRNAs in Vascular Angiogenesis
Authors: Wang Zhiguo
Published: November 2012

Several processes including endothelial angiogenesis, vascular neointimal lesion formation, vascular
inflammation process, lipoprotein metabolism, and hypertension are critically involved in antherogenesis or
atherosclerosis. This chapter aims to introduce the role of miRNAs in endothelial angiogenesis. Angiogenesis is
the growth of new blood vessels from pre-existing vessels. Functional endothelial cells are required for
angiogenesis, a process involving proliferation, migration, and maturation of endothelial cells. Several miRNAs
have been shown to critically regulate vascular angiogenesis and they can be classified into pro-angiogenic
miRNAs and anti-angiogenic miRNAs. Pro-angiogenic miRNAs indentified to date include miR-130a, miR-
17~92 cluster, miR-210, miR-378, miR-7f, miR-27b, and miR-126. The known anti-angiogenic miRNAs include
miR-320, miR-221 and miR-222. In addition, the miRNAs that are reportedly involved in tumor vascular biology
are also introduced in this chapter.
miRNA Interference Approaches for Cardiovascular Disease
Authors: Wang Zhiguo
Published: November 2012

miRNA interference (miRNAi) is a new concept that I proposed for the development of strategies and
technologies to manipulate the function, stability, biogenesis, or expression of miRNAs and as such it indirectly
interferes with expression of protein-coding mRNAs. This chapter aims to give an implicitly detailed introduction
to some of the miRNAi strategies and technologies developed so far. The fundamental mechanism of miRNA
regulation of gene expression is miRNA:mRNA interaction or binding. A key to interfere with miRNA actions is
to disrupt the miRNA:mRNA interaction. In order to achieve this aim, one can either manipulate miRNAs or
mRNAs to alter the miRNA:mRNA interaction. For miRNAs, one can either mimic miRNA actions to enhance
the miRNA:mRNA interaction or to inhibit miRNAs to break the miRNA:mRNA interaction. Both gain-offunction
and loss-of-function technologies are necessary tools for understanding miRNAs. The miRNAi
technologies have opened up new opportunities for creative and rational designs of a variety of combinations
integrating varying nucleotide fragments for various purposes and provided exquisite tools for functional analysis
related to identification and characterization of targets of miRNAs and their functions in gene controlling
program. In addition, the miRNAi technologies also offer the strategies and tools for designing new agents for
gene therapy of human disease.
δScuti, γ Doradus and related stars
Authors: Luis A. Balona
Published: November 2012

The use of time-dependent convection has partially resolved the problem of the red edge of the δ Scuti instability strip. Both the κ mechanism and convective blocking are active driving agents in these stars. Recent space observations have destroyed the separation between δ Sct and γ Dor stars in the HR diagram. It seems that a cool δ Sct star is distinguished from a γ Dor star only in the relative amplitudes of the low and high frequencies and that hybrid behaviour is normal in most of these stars. In some δ Sct stars there are a large number of observed frequencies and in a few of these stars the spherical harmonic degree of many of these modes known. In spite of this, asteroseismology of these stars has not been successful. High-amplitude δ Sct stars offer interesting viewof the transition between δ Sct and Cepheid pulsations and provide valuable insights on the mode selection mechanism. The nature of the pulsations in peculiar stars such as λ Boo, Am and Ap stars still need to be understood. Recent models of Am stars taking disusion into account have led to a better understanding of the location of these stars in the HR diagram. However the detection of several pulsating Ap stars from recent space observations may pose a challenge. The number of pulsating pre-main sequence stars has increased greatly in recent years, but modelling of these stars has been slow. Attempts to detect predicted pulsation in brown dwarfs are also discussed.
Cepheids and RR Lyrae stars
Authors: Luis A. Balona
Published: November 2012

Nonlinear Cepheid models have recently allowed stellar parameters to be estimated from the shape of the light curve. Double-mode Cepheids o er even more constraints, allowing the metallicity to be derived as well. They have been used as metallicity probes in various stellar systems. The problem of what sustains doublemode pulsation appears to be controversial and is still unresolved. In the LMC there are more double-mode Cepheids pulsating in the rst and second overtone than in the fundamental and rst overtone. Another puzzle concerns the rate of period change in triple-mode Cepheids. Ultra low-amplitude Cepheids seem to follow a di erent period - luminosity (PL) law from classical Cepheids and present an interesting challenge, as does the discovery of nonradial pulsations in a few LMC Cepheids. The projection factor to be used in a Baade-Wesselink analysis is discussed. There is a small dependence of the Cepheid PL relation on metallicity and it is probably slightly nonlinear. The di erences in the PL relations between classical Cepheids, the anomalous Cepheids and between the BL Her, W Vir and RV Tau stars that comprise the Population II Cepheids are discussed. Recent studies indicate that anomalous Cepheids may have very low metal abundances. Nonlinear modelling of BL Her stars has been quite successful in explaining the shapes of the light curves. A recent modelling survey of RR Lyrae stars has greatly improved our understanding of the Oosterho groups. The physical parameters of RR Lyrae stars can be determined by comparing the shape of the light curve with model calculations. The origin of the Blazhko e ect still remains one of the greatest unsolved puzzles.
The Effects of Spatial Diversity on the Synchronization of MIMO-OFDM Systems
Authors: Zhou Yi , Wu Yik-Chung , Serpedin Erchin , Qaraqe Kalid
Published: November 2012

This chapter studies the influence of spatial diversity on the synchronization of MIMO-OFDM systems. Upon revising the main features of OFDM and diversity techniques, this chapter focuses on the following topics. First, the sensitivity of the MIMO-OFDM receivers to the residual synchronization errors is examined. Then the effects of spatial diversity on symbol timing and carrier frequency synchronization are investigated. Computer simulation results show that by exploiting the spatial diversity in MIMO-OFDM systems, the synchronization performance can be significantly improved.
Multiuser Diversity Gain in Orthogonal Frequency Division Multiplexing under Limited Channel Information Feedback
Authors: Seokhyun Yoon
Published: November 2012

Dynamic resource allocation and throughput behaviour of multiuser OFDM will be considered with three limited CSI feedback schemes, namely sub-channelized OFDM, 1-bit/sub-carrier and selective feedback. It should be noted, however, that our aim is not to compare them in strict sense, i.e. comparison of throughput for a fixed amount of feedback. In fact, these limited feedback schemes are not technically conflicting, but can be used simultaneously for further reduction in feedback overhead, and our objective is to provide insight into the system behaviour under the limited feedback schemes by exploring the relationship between the throughput and the respective design parameters.
Host-pathogen Communication
Authors: P Sircili Marcelo , G Moreira Cristiano , Sperandio Vanessa
Published: November 2012

Chemical communication between pathogens and host mucosal cells corresponds to a dynamic array of
molecular interactions. The signature molecules unique to microbial pathogens allow the mammalian immune
system to recognize them as a foreign element. This recognition is usually mediated by receptor proteins, which
can be classified as toll-like receptors, and recently described as nod-like receptors. These interactions result in
innate immune responses targeted against the invading organism. Pathogens also elaborate a variety of proteins
that actively engage host signaling pathways and subvert them to facilitate their growth and dispersal. The host
function alterations are mediated by microbial pathogens including inflammatory responses, secretory responses,
alteration of host cytoskeleton, disruption of epithelial tight junctions and apoptosis. Important interactions
between pathogens and host cell involves chemical signaling, that depends on cell density and signaling
molecules identified as autoinducers that function as hormone-like molecules in a phenomenon also known as
quorum sensing. Pathogens can use these systems to colonize and cause disease in the host, and we will further
discuss these mechanisms in this chapter. Chemical signaling involved in these interactions are potential targets
for therapeutic strategies against infectious microbes.
Fungal Enzymes: Present Scenario and Future Perspectives
Authors: Uma Maheswar Rao J.L. , Boorgula G.D.Y. , Lúcia Leitão Ana
Published: November 2012

As a conservative estimate, some 120,000 species of fungi have been isolated. Many of these have
been screened for their ability to produce industrially sound products. Fungi have been important in both ancient
and modern biotechnological processes. They are of excellent value in nutrition, processes and products that
utilize fungi include production of sugars, antibiotics, enzymes, organic acids, baking, brewing, alcohols, and
numerous pharmaceuticals. α-Amylases and glucoamylases are used in the conversion of starch into different
sugar syrups. Industrial applications generally require amylases with a very specific hydrolysis profile. The
commercially used fungal amylases have certain limitations such as moderate thermostability, acidic pH
requirement, and slow catalytic activity that increase the process cost. The importance of retrogradation of starch
fraction in bread staling has been emphasized. A loss of more than US$1 billion is incurred in USA alone every
year due to the staling of bread in winters. There is a need for good additives and enzymes for preventing staling
and to improve the texture and shelf life of baked products. Pectinases are one of the upcoming enzymes of fruit
and textile industries. These enzymes are required for the break down of complex polysaccharides of plant tissues
into simpler molecules like galacturonic acids. The role of acidic pectinases in bringing down the cloudiness and
bitterness of fruit juices is well established. The production of pectinolytic enzymes has been widely explored in
filamentous fungi. However, there are a very few reports on the production of pectinases by thermophilic moulds
for food applications. About two thirds of the phosphorus in plant ingredients for pigs and poultry is in the form
of salts of phytic acid (myoinositol hexakisphosphates, phytates), which are not very soluble and of very limited
digestibility. This area of research has advanced to the extent that enzymes are commonly required in poultry
diets to enhance the nutritive value of cereals. This review focuses attention on the present status of knowledge on
the production, characterization, and potential applications of fungal biocatalysts (alpha amylases, glucoamylases,
pectinases and phytases) in food industry.
Dental Infections and Cardiovascular Disease - The Early Findings
Authors: Mattila Kimmo
Published: November 2012

The clinical entity “coronary heart disease (CHD)” comprises two major
components – atherosclerosis (AS) of the coronary arteries and acute thrombosis that
occasionally occurs superimposed on an atherosclerotic artery wall, causing various types of
acute coronary syndromes (ACS) like acute myocardial infarction (AMI). As CHD is a major
cause of mortality and morbidity in the Western societies, massive research efforts have been
invested in it. It has become clear e.g. that the triggering factors for acute manifestations of
CHD are not identical to the slow-acting, classic risk factors for coronary AS. The large
impact of hypercholesterolemia, hypertension and smoking on the development of CHD has
been established already some decades ago. Yet they do no explain all clinical and
epidemiological features of CHD. These major CVD risk factors have dominated the research
filed, and it has not always been easy for other potential risk factors to receive attention and
research funding.
Linking the Evidence of Oral Infections as a Causal Factor for Cardiovascular Diseases
Authors: Haheim Lise  L.
Published: November 2012

Normal oral bacteria have an important function in the mouth in being a barrier
towards unwanted microbes, they exhibit immunological properties, and saliva has a
buffering capacity against their acid production in caries activity. Repressed normal flora
causes overgrowth of pathogens. Unless adequately controlled an overload of bacteria will
arise with the result of infections. Oral bacteria and their infection products produce a
reaction by the immune system in the defense of potential harm from infections. It is apparent
that many factors are involved as oral bacteria and their bacterial products have no function
in the circulatory system. Chronic periodontitis and dental infections are to a great extent
lifestyle diseases and as such are preventable in most instances. Coronary heart disease is
also considered to be greatly influenced by lifestyle factors and is also acknowledged to be a
disease of inflammation and oxidation. The possible outcomes of cardiovascular disease
considered are atherosclerosis, thrombosis, myocardial infarction, stroke, aneurysm of the
aorta, and heart valve disease. This review examines the relations between the two diseases
whether these are strong enough to establish oral infections as an independent risk factor for
CVD. Bridging the knowledge gap between these disease entities is important and this
research needs to be further developed.
Subject Index
Authors: Haheim Lise  L.
Published: November 2012

Full text available
Government Policies to Support Biofuel Production: Why and to What Effect?
Authors: K. Klein Kurt , G. Le Roy Danny
Published: November 2012

The principal reasons for using public policies to stimulate the production of ethanol in North America are
to lower greenhouse gas emissions, increase farm income through the introduction of a new market for farm
commodities, promote rural development and diversification, and reduce consumer reliance on imported fossil fuels.
All these policy objectives are satisfied to some extent by biofuel production and consumption in North America.
However, the degree to which they are fulfilled is modest at best, and there are important negative consequences.
Food Before Fuel: Issues and Price Effect
Authors: Zhang Zibin , Wetzstein Michael
Published: November 2012

Fuel-ethanol expansion contributed to the recent volatility in agricultural commodity prices, causing a
price bubble. Results indicate decentralized competitive markets will mitigate any persistent price volatility.
Policies should then be directed toward preventing the occurrence of price bubbles and, if they do occur,
diminishing their magnitude.
Impact of Voluntary Carbon and Bioenergy Markets on Non-Industrial Private Forest Landowners' Profitability
Authors: Dwivedi Puneet , Alavalapati Janaki , Carter Douglas , Larkin Sherry
Published: November 2012

This chapter adopts a case study approach to study the impact of voluntary carbon and bioenergy
markets on the profitability of non-industrial private forest landowners. How an acre of intensely managed slash
pine (Pinus elliottii) impacts on the optimal rotation age of a plantation is also assessed. A carbon plantation in
the southern United States is selected as a representative case. The payment guidelines from the Chicago Climate
Exchange were followed. A life-cycle analysis was conducted to ascertain the emissions from various
silvicultural activities. It was assumed that only logging residues available from forestland will be utilized for
bioenergy production. It was found that land expectation values increased by about 49 percent (with thinning) and
50 percent (without thinning) by including payments for net carbon sequestered in the live biomass and logging
residues, but the optimal rotation age of 22 years did not change.
Consumer Geographic Segmentation and Valuing Attributes of Wine in Supermarket: An Hedonic Approach
Authors: Carlos Ortuzar Juan , Alfranca Oscar
Published: November 2012

The main objective of this study is to determine the relevance of the main attributes for wine, in some
geographic areas in supermarket of Santiago, Chile. The study allows us to estimate how different the value of
wine characteristics could be depending on different geographical areas. The information used is a panel database
for stores. Information from wine guides is also to be considered. These wine guides relate ranking positions with
quality attributes. An hedonic model will be estimated. Hedonic models have been widely applied to determine
the main characteristics of wine. In general, hedonic studies have focused on wine color or price level
segmentation, but these have not been associated with different geographic areas associated with different
socioeconomic levels. In this paper, brands and ranking appear to be relevant characteristics for wine value in all
segments, mainly because consumers have been exposed to marketing activities, and can detect quality
differences between wine brands. The size of bottle is very relevant.
Littoral Man and Waterside Woman: The Crucial Role of Marine and Lacustrine Foods and Environmental Resources in the Origin, Migration and Dominance of Homo sapiens
Authors: C. Leigh Broadhurst  , Michael Crawford  , Stephen Munro
Published: November 2012

The ability to exploit and thrive on a wide variety of foodstuffs from diverse environments is a hallmark of Homo sapiens. Humans are particularly well adapted to exploit waterside environments, where they can forage in areas offering protection from both terrestrial and aquatic predators. Humans are able to walk, run, climb, wade, swim and dive, and our research indicates that the most parsimonious explanation for this combination of locomotor traits, and for Man's current anatomy, physiology, nutritional requirements and unique intellect is evolution in a littoral environment. This model is consistent with the location and presumed palaeoecologies of all early Homo fossils and artifacts, and could help explain the rapid dispersal of Homo in the early Pleistocene (2.56-0.78 million years ago (Ma)), the colonization of Australia and Indonesia in the middle Pleistocene (0.78-0.13 Ma), and the rapid dispersal of Homo sapiens in the late Pleistocene (0.13-0.012 Ma). Reliance on the aquatic food chain is also a facile method for providing consistently abundant brain-specific nutrition for all members of a group or society, thus facilitating the development of the technology and culture that is uniquely human.
Langdon's Critique of the Aquatic Ape Hypothesis: It's Final Refutation, or Just Another Misunderstanding?
Authors: Algis V. Kuliukas
Published: November 2012

Thus far, there has been no challenge to Langdon's 1997 critique [1]of the aquatic ape hypothesis (AAH), despite its having a number of weaknesses. The paper lacks scholarliness as it does not draw upon the one published scientific investigation into the plausibility of the AAH in the literature, i.e., that byRoede et al. [2]. Langdon's summary of “anatomical evidence for the AAH” seems to have been directed against an exaggerated interpretation of Alister Hardy's hypothesis that humans were “more aquatic in the past” [3]. Most of the critique was based on cursory and superficial comparisons with fully aquatic mammals, such as cetaceans, rather than considering whether human ancestors could have been more aquatic than those of apes. Even on this basis, Langdon considered eleven out of twenty-six traits to be “possible aquatic adaptations” or “consistent with the AAH”.

It is argued here that none of the specific hypotheses of the AAH have yet been refuted. Instead, what appears to have happened, is that individuals have been left to interpret certain ambiguities in arguments put forward by proponents of the hypothesis in their own way and then reject, or accept it on that basis. More than a decade later, significant new evidence has emerged, and other AAH-based models have been published, which demand serious reconsideration.
Black Body Approach: Parametric Version
Authors: V. Arabadzhi Vladimir
Published: November 2012

In this chapter, we use simple models for acoustical waves (Section 3.1) [59], [61], [63], [64], [59], for
water surface waves (Section 3.2) [62], [59], [61], [50], and for electromagnetic waves (Section 3.3) [65]. On the
basis of these models, we consider the new concept of parametric "black body" with conceptual possibility of
designing an active absorbing (nonreflecting) coatings in the form of a thin layer with small-scale stratification
and fast temporal modulation of parameters. Algorithms for spatial-temporal modulation of the controlled-layer
structure are studied in detail for a one-dimensional boundary-value problem. These algorithms do not require
wave-field measurements, which eliminate self-excitation problem, that is the characteristic of traditional active
systems. The majority of the considered algorithms of parametric control transforms the low-frequency incident
wave to high-frequency waves of the technological band for which the waveguiding medium inside the layer is
assumed to be opaque (absorbing). The efficient conditions of use are found for all the algorithms. It is shown
that the absorbing layer can be as thin as desired with respect to the minimum spatial scale of the incident wave
ensuring efficient absorption in a wide frequency interval (starting from zero frequency) that is bounded from
above only by a finite space-time resolution of the parameter-control operations. The structure of a threedimensional
parametric "black" coating, whose efficiency is independent of the angle of incidence of an incoming
wave is developed on the basis of the studied one-dimensional problems. The general solutions of the problem of
diffraction of incident waves from such coatings are obtained. These solutions are analyzed in detail for the case
of a disk-shaped element.
Can Research Design Explain Variation in Head Start Research Results? A Meta-Analysis of Cognitive and Achievement Outcomes
Authors: Shager Hilary M. , Schindler Holly S. , Magnuson Katherine A. , Duncan Greg J. , Yoshikawa Hirokazu , Hart Cassandra M. D.
Published: November 2012

This study explores the extent to which differences in research design explain variation in Head Start program impacts. We employ meta-analytic techniques to predict effect sizes for cognitive and achievement outcomes as a function of the type and rigor of research design, quality and type of outcome measure, activity level of control group, and attrition. Across program evaluations, the average program-level effect size was 0.27 standard deviations. About 41% of the variation in estimates across evaluations can be explained by research design features, including the extent to which the control group experienced other forms of early care or education, and 11% of the variation within programs can be explained by the quality and type of the outcome measures.
Exploring Older Adults' Patterns and Perceptions of Exercise after Hip Fracture
Authors: Gorman Erin , Chudyk Anna M. , Hoppmann Christiane A. , Hanson Heather M. , Guy Pierre , Sims-Gould Joanie , Ashe Maureen C.
Published: November 2012

Purpose: To identify exercise patterns and perceived barriers, enablers, and motivators to engaging in exercise for older adults following hip fracture. Method: Telephone interviews were conducted with older adults (aged 62–97 y) within 1 year after hip fracture. Participants were asked about basic demographic information; level of mobility before hip fracture; current level of mobility; and barriers, enablers, and motivators to participating in exercise. Results: A total of 32 older adults successfully recovering after hip fracture completed the telephone interviews. Participants reported few problems with their mobility, and all were engaging in exercise. There were few reported barriers to exercise; the most common were health-related concerns (pain, fatigue, illness, or injury). The most frequently reported enablers were intrinsic factors (determination, seeing improvements, and making exercise part of their daily routine); in particular, the most common motivator to exercise was recovery of function to improve mobility and complete daily and leisure activities. Conclusions: This study highlights the responses of a group of older adults recovering well after hip fracture. Older adults engage in exercise despite the potential limitations associated with a hip fracture. Participants' responses underscore the importance of intrinsic factors and suggest avenues for future investigation.
Hydrothermal synthesis of nano nickel phosphides and investigation of their thermal stability
Authors: Wang Bo , Huang Xiang , Zhu Zhibin , Huang He , Dai Jinhui
Published: November 2012

Nanometer scale nickel phosphide particles (Ni2P and Ni12P5) were synthesized via a mild hydrothermal method with red phosphor and nickel chloride as raw materials. X-ray diffraction, energy dispersive spectrometry, transmission electron microscopy, scanning electron microscopy and differential thermal analysis–thermogravimetric analysis were employed to characterize the resulting products. The results showed that the as-prepared products were well crystallized and particle sizes ranged from 10 to 40 nm. Investigation of raw material ratios and initial pH of the reaction system showed increasing P/Ni ratio did benefit the formation of Ni2P but went against obtaining Ni12P5 and nano-particles were obtained only in an alkaline environment. Subsequent differential thermal analysis–thermogravimetric analysis indicated that Ni2P remained as the major phase till 500 °C in an air atmosphere.
Magnetic properties of Nd-Fe-Co-Al rapid solidification alloys
Authors: Dan Nguyen Huy , Hung Luu Tien
Published: November 2012

Nd-Fe–Al–Co alloys with thickness of 0.05–4 mm were prepared by means of rapid solidification methods, suction-casting and melt-spinning, and investigated using X-ray diffraction, electron microscopy and magnetization measurements. With appropriate composition and quenching rate, the alloys behave as single-phase hard magnetic materials. Coercivity of the alloys can reach 7.6 kOe at room temperature and exceed 30 kOe at 100 K. When the thickness of the alloys is increased, multi-magnetic phase behavior is clearly performed and Nd2Fe15Al, NdAl2, Nd3Al and Nd phases are further crystallized. The optimal hard magnetic properties of the alloys closely related to a microstructure which consists of nanocrystallites with size of 10–30 nm dispersed in an amorphous matrix. The hard magnetic phase in the alloys belongs to the amorphous phase. The nanocrystallites, whose total volume fraction is very small in comparison with that of the amorphous phase, probably act as pinning centers, resulting in high coercivity behavior of the alloys.
Select Bus Service on M15 in New York City
Authors: Beaton Eric B. , Barr Joseph E. , Chiarmonte Joseph V. , Orosz Theodore V. , Paukowits Dominique , Sugiura Aaron
Published: November 2012

Constrained and congested streets hinder accelerated transit service and the provision of protected space for cycling. Although bus rapid transit has proved effective at improving transit service in cities, the addition of a physical priority for transit must be balanced against competing needs for traffic flow and parking, particularly in areas with high levels of activity. On October 10, 2010, the New York City Transit Authority of the Metropolitan Transportation Authority—now known as MTA New York City Transit—and the New York City Department of Transportation implemented the M15 select bus service on First and Second Avenues. This bus rapid transit service generated a significant improvement to transit service in a constrained corridor and created space for safe bicycling facilities and pedestrian safety improvements, and all general traffic flow along the corridor was maintained. The M15 select bus service improved bus speed and reliability with proof-of-payment fare collection, new bus lanes, and improved bus lane treatments, including offset bus lanes (next to the parking lane). Passenger comfort and reliability were also enhanced through route simplification, improved scheduling, enhanced stations, and better customer information. The results have been noteworthy, with a 15% to 18% improvement in travel time and a 10% increase in corridor ridership. Cycling has also increased substantially along the corridor, on which new parking-protected bike lanes were installed as part of the project. These gains were achieved through close coordination with all corridor stakeholders, careful use of priority treatments on parts of the corridor, and the close working partnership between the New York City Department of Transportation and MTA New York City Transit.
Comparative Study of Emissions from Bus Rapid Transit and Conventional Bus Systems
Authors: Chen Xumei , Yu Lei , Song Guohua , Xian Chenyang
Published: November 2012

Bus rapid transit (BRT) systems play an increasingly important role in urban transit systems throughout the world because they provide fast and reliable public transportation. BRT systems are designed to reduce harmful emissions, which are usually significant for diesel engines in conventional bus transit systems. However, a quantitative comparison of emissions is needed to verify whether reductions have been achieved. This paper compares the characteristics of the emissions of diesel transit vehicles from BRT and a conventional bus system to provide support for policy decisions on public transit management in Beijing. A vehicle-specific power-based emissions estimation approach was implemented with a heavy-duty transit vehicle that ran on diesel fuel to analyze the characteristics of the emissions of a BRT diesel vehicle and a conventional diesel bus on the Fifth Ring Road of Beijing. The emissions characteristics were compared from a spatial perspective (i.e., scenarios involving non–bus lanes, bus lanes, and an area near a stop or a station). The BRT system was shown to play a significant role in reducing emissions, compared with those from a conventional diesel bus, with 25.62% to 27.37% reductions in emissions mass per kilometer of oxides of nitrogen, hydrocarbons, carbon monoxide, and particulate matter under the non–bus lane scenario, 12.76% to 14.01% reductions under the bus lane scenario, and 22.94% to 37.25% reductions under the scenario near a stop or station. These results have important policy implications for development of strategies for public transit systems in Beijing.
Optimization of Spacing of Transit Stops on a Realistic Street Network
Authors: Mekuria Maaza C. , Furth Peter G. , Melachrinoudis Emanuel
Published: November 2012

A discrete model of bus stop location in which candidate stops are either selected or not has several practical advantages over classical continuum models. An evaluation method for stop sets that uses parcels as units of demand and the street network to model walking paths between transit stops and parcels has been proved effective and realistic. In this framework, the on–off counts at existing stops are used to allocate demand to the parcels in each stop's service area in proportion to the stops' trip-generating ability. The result is a demand distribution that matches existing counts and reflects variations in land use. However, with demand modeled on the street network, the placement of service boundaries midway between neighboring stops becomes invalid because of irregularities in the network of access streets and curves in the transit route. The dependence of a stop on more than its immediate neighbors for determination of its service area complicates the process of optimization of stop locations by use of dynamic programming. The proposed solution expands the state space so that a stop's service area is dependent on the two prior and the two succeeding stops. The resulting dynamic programming model was tested on two bus routes and found solutions that were better than the existing stop set and the stop sets proposed by consultants by use of simple yet state-of-the-art models. This paper describes a method for optimization of stop locations on an existing route that includes realistic and localized estimates of its impacts on walking and riding times and operating cost.
Grouping of Bus Stops for Aggregation of Route-Level Passenger Origin–Destination Flow Matrices
Authors: McCord Mark R. , Mishalani Rabi G. , Hu Xudong
Published: November 2012

Route-level, bus passenger origin–destination (O-D) matrices summarize useful information on travel patterns for use in route planning, design, and operations. However, the size of stop-to-stop O-D matrices makes it difficult to synthesize important flow patterns and to estimate stop-to-stop O-D passenger flows accurately. To reduce the size of the O-D matrix for improved estimation, analysis, and communication, stops can be grouped so that passenger flows between far fewer stop group pairs can be estimated and represented. The problem of grouping of bus stops for aggregation of passenger O-D flows is presented with the explicit objective of reducing the passenger O-D flow matrix while capturing important O-D flow characteristics. Two computationally efficient heuristic algorithms for solution of this problem are proposed. A set of empirical studies—conducted with automatic passenger counter data collected on major bus routes operated by the Ohio State University's Campus Area Bus System, the Central Ohio Transit Authority, and the Los Angeles County, California, Metropolitan Transit Authority—shows that the stop group configurations identified with the proposed heuristic algorithms are close to optimal and capture pertinent flow patterns and dominant clusters of stops much better than stop group configurations produced from land use characteristics. The heuristic algorithms can identify solutions for all possible numbers of stops with a reasonable computational time, whereas optimal configurations can be found for only a few groups on long routes.
Competition from the Curb
Authors: Schwieterman Joseph , Fischer Lauren Ames
Published: November 2012

To foster a greater understanding of the composition and preferences of travelers served by discount curbside bus operators, this study summarizes the results of a survey of such passengers. The study compares the characteristics of passengers using the two largest operators, Bolt-Bus and Megabus, with those using conventional bus lines such as Greyhound. Surveys were administered in the three most heavily served curbside bus markets in the East and Midwest of the United States—six cities in total—and the result was a cumulative sample of 1,025 responses. Curbside bus service was shown to have generated much new travel, with newly generated trips accounting for 22.0% of all passengers. In the East, however, curbside bus service is taking many travelers from passenger trains. More than a third of those surveyed (34.0%) report that they would have ridden trains had curbside buses not been available. In all markets surveyed, ridership heavily comprised passengers in the group 18 to 25 years of age and was overwhelmingly made up of passengers traveling for pleasure or personal matters rather than for business. When the findings are interpreted broadly, they support the notion that the curbside bus phenomenon is not primarily the result of a shift in market share from conventional bus lines. The evidence instead suggests that curbside bus service should be regarded as a new mode that attracts most of its passengers from commercial flights, trains, and private automobiles and that it has grown dramatically, despite the relative lack of business travelers.
Sharing the Costs of Human Services Transportation
Authors: Burkhardt Jon E. , Garrity Richard
Published: November 2012

With rising fuel prices and limited budgets, transportation providers are more frequently being asked to work cooperatively with other agencies to ensure the most cost-effective service delivery. This situation is particularly true for transportation for human services needs: public transportation providers and human services agencies are being asked to coordinate their efforts to ensure maximum productivity at minimum cost. Over the years, one commonly reported hindrance to coordination efforts is the lack of a common, systematic approach to documentation of transportation services and their costs. Many studies found that agencies that provide transportation services need better cost and service accounting to support coordination efforts. This paper results from work conducted for TCRP that described how costs should be allocated and shared among all stakeholders. The results of this project include a common framework for recording and reporting of transportation costs and services, whether they are provided by transit agencies or human services transportation providers and whether the transportation providers are large or small operations. Other products of the TCRP project include a transportation services cost-sharing model (developed in Excel format) and instructions on how to apply that model to community transportation services.
Taxicabs as Public Transportation in Boston, Massachusetts
Authors: Austin Drew , Zegras P. Christopher
Published: November 2012

In many American cities, the taxicab is an important but frequently overlooked public transportation mode and represents a significant opportunity to provide mobility in many places where conventional mass transit cannot do so cost-effectively. This paper investigates the taxicab and its role as a form of public transportation and uses the taxicab system in Boston, Massachusetts, to study the mode's function in the city as well as its relationship to other forms of transportation. The central inquiry of this paper is when and where the taxicab operates as a complement or a substitute to Boston's mass transit system and which factors appear to affect its fulfillment of each role. Taxicab activity in Boston is analyzed with trip-level data recorded for Boston taxicabs during the past 2 years, mapping of taxicab activity, and specification of regression models that illuminate significant relationships between the taxicab, transit access, and other characteristics of the urban environment. Evidence suggests that the taxicab acts as both a mass transit substitute and complement in Boston and that this tendency varies by transit line and time of day. These models are also used to infer the existence of unmet demand for taxicab service.
Evaluation of Zoning Design with Transfers for Paratransit Services
Authors: Shen Chung-Wei , Quadrifoglio Luca
Published: November 2012

This paper evaluates the effects of including transfers between service zones on overall service performance in a paratransit system. Transfers were included to improve the operational efficiency of a system when maintenance of a desirable zoning structure was obligatory. This proposed innovative service design was compared with more traditional cases of no transfer zoning and no zoning. A set of instances was generated from demand data obtained from the Metropolitan Transit Authority of Harris County, Texas, and evaluated through simulation analyses. The results demonstrated that under a zoning structure, this transfer design (in comparison with a nontransfer design) provided noticeable improvements in efficiency measures and better passenger trips per vehicle revenue hour while maintaining a minimum customer service standard; however, the overall performance of the no-zoning strategy used by the Houston, Texas, Metropolitan Transit Authority of Harris County performed the best, on average.
Role of Public Transportation as Job Access Mode
Authors: Lubin Andrea , Deka Devajyoti
Published: November 2012

Transportation barriers are often the reason for the discrepancy in the employment rate between people with disabilities and others, yet little information about the transportation barriers and the needs of people with disabilities who are searching for employment is available. The primary objective of this paper is to share valuable information from a unique survey of people with disabilities who were actively searching for employment in New Jersey. The paper examines the role of public transportation in providing job access to people with disabilities and provides information and insights on the availability, use, needs, barriers, and perceptions of the survey respondents about different public transit modes. The paper also discusses the implications for agencies that provide transportation for people with human services needs. Research shows that despite the frequent use of public transportation by job-seeking people with disabilities, many of them are dissatisfied with public transportation. Although satisfaction with vehicle equipment compliant with the Americans with Disabilities Act seems high, many individuals are dissatisfied with the level of transit service and environmental barriers between homes and transit stations and stops. It can be inferred from the results that a multitude of strategies will be needed to address the travel needs and barriers of job-seeking people with disabilities in the state. In addition to providing assistance with transportation for people with human services needs and providing insights to vocational rehabilitation counselors, the study will serve as a means for laying the framework for more rigorous research on the transportation needs and barriers of people with disabilities.
Rule-Based Forecasting of Traffic Flow for Large-Scale Road Networks
Authors: Zhang Li-Ye , Peng Zhong-Ren , Sun Daniel (Jian) , Liu Xiaofeng
Published: November 2012

As traffic data collection becomes less costly and more commonplace, large-scale traffic flow forecasting is increasingly needed. This paper proposes a rule-based approach for forecasting traffic flow based on the K nearest neighbor (KNN) nonparametric regression model, the rule-based KNN (RKNN) model. Rules were extracted from the historical data through the use of rough set theory, which found the nearest neighbors. Traffic impact factors, such as weather and time of day, were incorporated into the rules. Every historical record was labeled with a rule. With current data on traffic flow states and traffic flow impact, the nearest neighbors could be found quickly from the historical data records covered by the corresponding rule. An additional methodology was proposed to keep the historical data and the rules up to date. A case study on an Interstate freeway in Virginia, I-395, was conducted to evaluate the performance of the RKNN approach. The results showed that the proposed approach could decrease the mean absolute percentage error by 26.86%. Moreover, the proposed algorithm reduced calculation time by 65.69%, compared with the traditional KNN algorithms. This difference indicates the effectiveness of the proposed algorithm for use with large urban road networks.
Household Automobile and Motorcycle Ownership Analyzed with Random Parameters Bivariate Ordered Probit Model
Authors: Anastasopoulos Panagiotis C. , Karlaftis Matthew G. , Haddock John E. , Mannering Fred L.
Published: November 2012

This paper investigates the factors that affect household automobile and motorcycle ownership in large metropolitan areas. Extensive geocoded trip data from Athens, Greece, were modeled with the random parameters bivariate ordered probit model. This model accounts for unobserved heterogeneity in the data population and commonly shared characteristics with automobile and motorcycle ownership. The random parameters bivariate probit model provided a statistically superior fit compared with its fixed parameters counterpart. The study's results indicate that vehicle (automobile and motorcycle) ownership is determined by a number of factors, such as traveler characteristics, the population density at the origin and destination, the distance and time to the destination for several trip purposes, and access to public transit.