bluuebunny/crossref_metadata_2025 huggingface dataset:
Contraception in women with medical problems
Authors: Dhanjal Mandish K
Published: January 2009

Women with medical disease have a higher incidence of maternal mortality compared with healthy women, with cardiac disease now being the most common cause of maternal death in the UK. A handful of medical conditions exist where pregnancy is not recommended due to mortality rates approaching 50%. It is imperative that such women have the most reliable methods of contraception available. Contraceptive agents may themselves affect medical disease, or may interact with medications used by such women. There may be a range of contraceptive agents suitable for each medical condition. The contraceptive selected should be tailored to suit the individual. The following points should be considered when deciding on the most appropriate contraceptive agent: efficacy, thrombotic risk (oestrogen containing contraceptives), arterial risks (oestrogen containing contraceptives), infective risk (e.g. insertion of intrauterine device [IUD]), vagal stimulation (e.g. insertion of IUD, ESSURE®), bleeding risks with patients on anticoagulants, interaction with concomitant drugs, effects of anaesthesia and ease of use. This review aims to cover the different contraceptive agents available and the best ones to use for certain medical illnesses.
Securities Analysts and Incumbent Response to Radical Technological Change: Evidence from Digital Photography and Internet Telephony
Authors: Benner Mary J.
Published: January 2009

A large body of research has explored the factors that impede established firms' responses to radical technological changes. While it is widely acknowledged that managers face pressures from financial markets to choose strategies that maximize shareholder value, little work in the technological change literature has considered the possible influences of public equity markets and the securities analysts who mediate them on incumbent firms challenged with technological change. In this paper, I begin to address the topic by empirically exploring how securities analysts react to the different strategies undertaken by incumbent firms faced with radical technological change. I study the question in two settings: the shift to digital technology in photography and the advent of Voice over Internet Protocol (VoIP) technology in wireline telecommunications. I find evidence that analysts are more attentive and positive toward incumbents' strategies that extend and preserve the existing technology than toward strategies that respond directly to the new technology. In these settings, analysts largely ignore incumbents' strategies that directly incorporate the new technology for several years following the discontinuity. This study provides insights into the nature and direction of analysts' reactions to firms' strategies in the context of technological change, and is a first step toward better understanding of the potential role of analysts' and financial markets in incumbent adaptation.
Disposition of MDMA and Metabolites in Human Sweat Following Controlled MDMA Administration
Authors: Barnes Allan J , De Martinis Bruno S , Gorelick David A , Goodwin Robert S , Kolbrich Erin A , Huestis Marilyn A
Published: January 2009

Background: Understanding the excretion of 3,4-methylenedioxymethamphetamine (MDMA) and metabolites in sweat is vital for interpretation of sweat tests in drug treatment, criminal justice, and workplace programs.

Methods: Placebo, low (1.0 mg/kg), and high (1.6 mg/kg) doses of oral MDMA were given double-blind in random order to healthy volunteers (n = 15) with histories of MDMA use. Participants resided on the closed clinical research unit for up to 7 days after each dose. Volunteers wore PharmChek® sweat patches (n = 640) before, during, and after controlled dosing. Patches were analyzed by solid phase extraction and GC-MS for MDMA, methylenedioxyamphetamine (MDA), 4-hydroxy-3-methoxyamphetamine (HMA), and 4-hydroxy-3-methoxymethamphetamine (HMMA). Limits of quantification (LOQ) were 2.5 ng/patch for MDMA and 5 ng/patch for HMA, HMMA, and MDA.

Results: MDMA was the primary analyte detected in 382 patches (59.7%), with concentrations up to 3007 ng/patch. MDA was detected in 188 patches (29.4%) at <172 ng/patch, whereas no HMMA or HMA was detected; 224 patches (35.0%) and 60 patches (9.4%) were positive for MDMA and MDA, respectively, at the 25-ng/patch threshold proposed by the Substance Abuse and Mental Health Services Administration.

Conclusions: Sweat testing was shown to be an effective and reliable method for monitoring MDMA use in this controlled MDMA administration study. However, variability in sweat excretion suggests that results should be interpreted qualitatively rather than quantitatively. These data provide a scientific database for interpretation of MDMA sweat test results.
A Review on Modeling and Simulation of Quenching
Authors: Şimşir Caner , Gür C. Hakan
Published: January 2009

Modeling and simulation of quenching are powerful tools in the design, optimization, and understanding of the quenching process since they provide quantitative results such as the evolution of microstructure and the internal stresses, which are practically impossible to acquire experimentally. The research on simulation of quenching and related phenomena originates from the early 70s and is still an active field owing to its industrial and scientific output. This paper aims to provide a comprehensive review of those studies and to present the state of the art with a discussion of limitations and drawbacks of contemporary models with an emphasis on the complementary steps that have to be taken in collaboration with the industry.
Global West, American Frontier
Authors: Wrobel David M.
Published: January 2009

This article questions the common assumption that nineteenth-century audiences in America and around the world viewed the American western frontier as an exceptional place, like no other place on earth. Through examination of travel writings by Americans and Europeans who placed the West into a broader global context of developing regions and conquered colonies, we see that nineteenth-century audiences were commonly presented with a globally contextualized West. The article also seeks to broaden the emphasis in post-colonial scholarship on travel writers as agents of empire who commodified, exoticized, and objectified the colonized peoples and places they visited, by suggesting that travel writers were also often among the most virulent critics of empire and its consequences for the colonized.
Counter-Organizing the Sunbelt: Right-to-Work Campaigns and Anti-Union Conservatism, 1943–1958
Authors: Shermer Elizabeth Tandy
Published: January 2009

Right-to-work elections are one of the most understudied aspects in the formation of Sunbelt conservatism and the rise of the Right. After World War II, every Southwestern state put some kind of right-to-work referendum on the ballot. Support came from the most dynamic economic sectors whose anti-union activists stood in rebellion against the New Deal regulatory state. They promised prosperity based on laissez-faire growth to transform the region into a manufacturing power. Although not every proposition or bill passed, this ideological argument won over many voters, including members of the middle and working classes worried over labor's rapid growth and new-found power. The discourses in these early campaigns came to dominate national conversations about labor's power and legitimacy, suggesting that a pro-development anti-unionism was a pillar of western Sunbelt conservatism and the modern Right.
Fetoplacental growth and vascular development in overnourished adolescent sheep at day 50, 90 and 130 of gestation
Authors: Redmer Dale A , Luther Justin S , Milne John S , Aitken Raymond P , Johnson Mary Lynn , Borowicz Pawel P , Borowicz Magda A , Reynolds Lawrence P , Wallace Jacqueline M
Published: January 2009

To establish the basis for altered placental development and function previously observed at late gestation, fetoplacental growth and placental vascular development were measured at three stages of gestation in a nutritional paradigm of compromised pregnancy. Singleton pregnancies to a single sire were established and thereafter adolescent ewes were offered an optimal control (C) or a high (H) dietary intake. At day 50, the H group had elevated maternal insulin and amniotic glucose, whereas mass of the fetus and placenta were unaltered. At day 90, the H group exhibited elevated maternal insulin, IGF1 and glucose; fetal weight and glucose concentrations in H were increased relative to C, but placental weight was independent of nutrition. By day 130, total placentome weight in the H group was reduced by 46% and was associated with lower fetal glucose and a 20% reduction in fetal weight. As pregnancy progressed from day 50 to 130, the parameters of vascular development in the maternal and fetal components of the placenta increased. In the fetal cotyledon, high dietary intakes were associated with impaired vascular development at day 50 and an increase in capillary number at day 90. At day 130, all vascular indices were independent of nutrition. Thus, high dietary intakes to promote rapid maternal growth influence capillary development in the fetal portion of the placenta during early to mid-pregnancy and may underlie the subsequent reduction in placental mass and hence fetal nutrient supply observed during the final third of gestation.
Embryotoxicity of retene in cotreatment with 2-aminoanthracene, a cytochrome P4501A inhibitor, in rainbow trout (Oncorhynchus mykiss)
Authors: Scott Jason A. , Ross Meagan , Lemire Ben C. , Hodson Peter V.
Published: January 2009

Environmentally relevant mixtures of polycyclic aromatic hydrocarbons (PAHs; e.g., crude oils) are often rich in alkyl-PAHs, such as retene (7-isopropyl-1-methylphenanthrene), which produce dioxin-like toxicity in fish embryos. The mechanism of alkyl-PAH toxicity is not well understood but was previously thought to be mediated by cytochrome P4501A (CYP1A) enzymes. To understand the role of CYP1A in retene toxicity, we coexposed free-swimming rainbow trout (Oncorhynchus mykiss) embryos to 100 μg/L of retene and to a range of concentrations of 2-aminoanthracene (2AA; a known CYP1A inhibitor). Ethoxyresorufin-O-deethylase (EROD) assays of juvenile trout coexposed to 2AA and retene confirmed that 2AA inhibited CYP1A (median inhibitory concentration [IC50] for 2AA, 62 μg/L). In two independent trials, 2AA, both alone and in cotreatment with retene, produced a concentration-dependent increase in toxicity to embryonic trout. The toxicity resulting from 2AA alone is, to our knowledge, the first reported for embryonic stages of fish, with median lethal concentrations (LC50s) of 19 and 125 μg/L and overall sublethal median effective concentrations (EC50s) of 17 and 38 μg/L. Toxicity increased in embryos coexposed to retene and 2AA, resulting in LC50s of 14 and 17 μg/L of 2AA and overall EC50s of 7 and 3 μg/L of 2AA. The exposure-response curves for 2AA alone and for 2AA with retene were parallel, suggesting a common mode of action between the two treatment regimes and between retene and 2AA. Taken together with the juvenile EROD data, the toxicity of 2AA alone and in cotreatment with retene may be EROD (CYP1A) independent. The mixture toxicity was not consistent with previous coexposures to CYP1A inducers and inhibitors, suggesting that the current risk assessment model may not be a good predictor of PAH mixture toxicity.
Life and Work with Multiple Sclerosis (MS): The Role of Unseen Experiential Phenomena on Unreliable Bodies and Uncertain Lives
Authors: Vickers Margaret H.
Published: January 2009

This article extends my earlier Heideggerian phenomenological work (Vickers, 2001) which explored the life and work of people with unseen chronic illness. Here I report findings of another phenomenological study where I interviewed people with Multiple Sclerosis (MS) about their life and work. For around 70% of people with MS, the disease is characterized by seemingly random cycles of exacerbations (relapses) and remissions. Often, their disease is unseen by others. Even those that have visible disabilities are highly likely to have many unseen symptoms. Fatigue, diminished strength and stamina, bowel or bladder dysfunction, visual impairment, depression, anxiety, pain, cognitive difficulties, and sexual dysfunction may all prove challenging for people with MS during their life and work. In addition to unseen symptoms are other unseen personal phenomena impinging on these people's lives that are not understood by others, such as thoughts and emotions. Twenty-one interviews were conducted resulting in over 43 hours of interview data from 35 tapes, and 335,258 words and 1,222 pages of verbatim transcribed data. What is presented here is the role of the various unseen personal phenomena in the 2 emergent phenomenological themes: unreliable bodies and uncertain lives.
Stressful Situations the First Six Months after a Stroke
Authors: Brunborg Birgit
Published: January 2009

The main purpose of this study is to categorize and analyze the most stressful situations perceived by stroke patients during a period of 6 months after experiencing a stroke. The events that have an impact on the subjective well-being and the intensity of the stress are also investigated. A clinic-based sample of 82 hospitalized stroke patients were studied 4 times after the stroke incident. They were asked to describe and appraise the most stressful event or situation that had affected them during the last 3 days. The data analysis was conducted according to phenomenological and hermeneutical methods. The study was approved by the Regional Committee for Ethics in Medical Research. The reported difficulties after a stroke have been separated into 5 categories: 1) impairments and disabilities in bodily functions; 2) communication and memory problems; 3) negative thoughts, depression and loneliness; 4) anxiety, fear, and worries; and 5) anger. Stressful situations in the first category were the most frequently reported, while those in the fourth category increased during the first 2 weeks after discharge, but decreased again within 3 months after the stroke. Encounters in the second category were less reported over time while those in the third category tended to become a more stable emotional state. Some interviewees expressed anger (category five). Few described relief or no difficulties at all. In total, the intensity of the stressful events decreased strongly. The increased occurrence of anxiety, fear, and worries during the first weeks after discharge from hospital gives rise to concern. These strains coincide with the withdrawal of health services.
Reciprocity in Crisis Situations
Authors: Thompson Sue
Published: January 2009

Crises, by their very nature, are characterized by a feeling of being over-whelmed, as we are faced with situations that call for responses above and beyond those which we normally have to face and for which we have developed the coping skills and strategies we need to deal with them. In times of crisis we are taken outside of the “comfort zone” of our experience and competence, and so there is the potential for the sense of self-esteem which comes from that competence to be compromised if we are left floundering and unsure of ourselves. In this article I explore how reciprocity—being able to give back as well as to receive—can contribute to the rebuilding of our self-esteem, but I also suggest that its potential for empowerment is often overlooked or undervalued when there is a high level of pressure to deal with situations quickly. Those of us who work in the “helping professions” derive some of our own self-esteem from being able to competently remove people from danger or despair. If, however, in responding to our own desires to be useful and valued, we create or reinforce dependency in others by denying them an opportunity to feel valued and useful too, we run the risk of reinforcing the feelings of helplessness and powerlessness that crises can so readily engender. This article therefore argues the case for developing a fuller and clearer understanding of reciprocity and the dangers of it being neglected in the heat of the crisis moment or in the aftermath.
Incentive Schemes in Peer-to-Peer Networks
Authors: Loginova Oksana , Lu Haibin , Wang X. Henry
Published: January 2009

In this paper we study the optimal file-sharing mechanism in a peer-to-peer network with a mechanism design perspective. This mechanism improves upon existing incentive schemes. In particular, we show that peer-approved scheme is never optimal and service-quality scheme is optimal only under certain circumstances. Moreover, we find that the optimal mechanism can be implemented by a mixture of peer-approved and service-quality schemes.
No Small Thing: School District Central Office Bureaucracies and the Implementation of New Small Autonomous Schools Initiatives
Authors: Honig Meredith I.
Published: January 2009

New small autonomous schools initiatives are relatively recent educational change strategies that in some urban districts aim to remake how district central offices function as institutions. In this article, the author draws on theories of organizational innovation and learning to reveal how central office administrators participate in these change processes, what outcomes are associated with their efforts, and the conditions that help or hinder their work. The data came from a 3-year qualitative investigation of these dynamics in two districts. The results show that particular bridging and buffering activities by certain central office administrators were consistent with policy goals and linked to increasing district supports for implementation. Particular dimensions of the institutional environments of central offices shaped central office administrators’ choices and actions.
Piecewise Optimum Delay Estimation for Improved Signal Control
Authors: Yi Ping , Shao Chun , Wang Yinhai
Published: January 2009

An adaptive control strategy called Piecewise Optimum Delay Estimation (PODE) was developed and tested. This paper reviews the advantages of the existing adaptive control strategies over the actuated control scheme and uses their limitations as the basis for improvement. By using real-time traffic as input, PODE dynamically searches movement combinations for phasing and timing decisions that minimize piecewise system delay. Preliminary results show that PODE can considerably and consistently reduce delay more than actuated control can. Supported by a self-adjusting procedure, PODE control logic has demonstrated its competitive strength among other adaptive control strategies, especially under congested and oversaturated conditions.
Evaluation of Variable Maximum Green Time to Improve Rural Traffic Signal Operations
Authors: Click Steven M. , Rajagopalan Aswini
Published: January 2009

Rural agencies frequently struggle to provide reasonable traffic signal operations because they lack the financial resources and traffic expertise common to larger cities. More advanced traffic signal controllers have many features that might help. One such feature is variable maximum green time (VMGT), also called the dynamic maximum, which allows the controller to continually adjust the maximum green in response to changes in traffic demand. Rural traffic signal operations are compared, given optimized timing with rural traffic signal control operations using a generic set of VMGT parameters. The research method included the use of software-in-the-loop simulation with VISSIM as the traffic simulation model and Econolite ASC/3 traffic controller software. Results from one high-volume and one low-volume site indicate that compared with optimized timings, a generic set of VMGT parameters can provide equivalent throughput, nearly equivalent average intersection delays, reasonable cycle lengths, and a more equal distribution of delay among approaches and movements.
Reduced Overestimation in Forecasting Telecommuting as a Travel Demand Management Policy
Authors: Tal Gil
Published: January 2009

Overestimated forecasts of the impacts of new policies, that is, over-prediction of the successes of the policies, are a well-known problem. Study of the effects of forecasting methods on potential bias may help modelers, planners, and policy makers better use forecasting tools. This paper addresses the overestimation of the success of telecommuting as a travel demand management policy. The research hypothesis underlying this study posits that overestimates of performance are virtually inevitable when the effects of new policies that aim to change travel behavior are forecast but that these biases eventually decline over time. The sources of overestimated forecasts are the prediction tools used and the ways in which modelers use these tools. The sources of the reduction in overestimation are the changes made to these tools and the knowledge and the data gained over time.
Joint Model of Choice of Residential Neighborhood and Bicycle Ownership
Authors: Pinjari Abdul Rawoof , Eluru Naveen , Bhat Chandra R. , Pendyala Ram M. , Spissu Erika
Published: January 2009

This paper presents a joint model of residential neighborhood type choice and bicycle ownership. The objective is to isolate the true causal effects of neighborhood attributes on household bicycle ownership from a spurious association because of residential self-selection effects. The joint model accounts for residential self-selection because of both observed sociodemographic characteristics and unobserved preferences. In addition, the model allows differential residential self-selection effects across different sociodemographic segments. The model was estimated by using a sample of more than 5,000 households from the San Francisco, California, Bay Area. Furthermore, a policy simulation analysis was carried out to estimate the impacts of neighborhood characteristics and sociodemographics on bicycle ownership. The model results show a substantial presence of residential self-selection effects because of observed sociodemographics, such as the number of children, dwelling type, and house ownership. It is shown for the first time in the self-selection literature that ignoring such observed self-selection effects may not always lead to overestimation of the impact of neighborhood attributes on travel-related choices, such as bicycle ownership. In the current context, ignoring self-selection because of sociodemographic attributes resulted in an underestimation of the impact of neighborhood attributes on bicycle ownership. In the context of unobserved factors, no significant self-selection effects were found. However, it is recommended that such effects as well as the heterogeneity in such effects be tested for before it is concluded that there are no unobserved factors contributing to residential self-selection.
Exploring the Influence of Urban Form on Work Travel Behavior with Agent-Based Modeling
Authors: Lu Yandan , Kawamura Kazuya , Zellner Moira L.
Published: January 2009

This paper examines the effect of land use regulations on travel behavior by using agent-based modeling. A simulation model for a hypothetical urban area loosely based on the Chicago, Illinois, metropolitan area was used to study the impact of six land use regulation scenarios on transit use and urban form. The key features and techniques of the model development and the scenarios tested are described. The results from the simulations showed that although the land use regulations that were designed to increase the density near the transit station or in and near the urban core were able to achieve the intended land use patterns, they did not increase the transit mode share for the region in a significant manner. More detailed examination of the output revealed that as long as the rules for mode choice, the distribution of employment, and the transit network remained unchanged, land use regulations that affect residential locations produced limited effects on transit use.
Identification of Parameters for a Prospect Theory Model for Travel Choice Analysis
Authors: Avineri Erel , Bovy Piet H. L.
Published: January 2009

Travelers’ responses to the risk and the uncertainty involved in their travel choices have been argued to be a research area that can be better addressed by use of a descriptive approach rather than a normative one. Prospect theory, a descriptive model of decision making under conditions of risk and uncertainty, has recently been incorporated into travel behavior modeling. This paper describes some of the major challenges that modelers face when they apply prospect theory to risky travel behavior contexts. In particular, the options available for determination of the values of crucial parameters for prospect theory travel choice models, such as the reference point and the loss aversion factor, are discussed. Prospect theory has originally been proposed to capture the observed choices between alternatives framed as lotteries and gambles and has fruitfully been applied to some settings in economics. However, because of some of the unique characteristics of travel journeys and the environment of decision making, the application of prospect theory to a travel choice context is not trivial. Modeling challenges because of a lack of consensus reference point values and other difficulties in setting values for other parameters are described, and several methodological approaches that can be used to set the values of parameters for prospect theory are suggested and illustrated.
Two Cities, Two Realities?
Authors: Roorda Matthew J. , Morency Catherine , Woo Karen
Published: January 2009

Capitalizing on large-scale origin-destination travel surveys conducted in two large Canadian urban centers, Montreal and Toronto, this paper presents a comparative analysis of the travel behavior trends in relation to variables such as demography, car accessibility, home location, and employment status. With trip rate as the dependent variable, three disaggregate multivariate regression models were estimated to observe how behaviors have evolved over time and how individual features affect the way in which people travel. These multivariate models allow the observation of the similarities and differences between explanatory factors between regions and over time. Although both cities are facing similar trends, such as the aging of the population, increasing rates of motorization, declining household sizes, and urban sprawl, they are also the sites of different trends with respect to average trip rates, differences between genders, and the impacts of car access. The geographic and cultural differences found between the populations of Toronto and Montreal include a smaller gender impact on trip generation in Montreal and a smaller age impact in Toronto. The study identified changes in the magnitude of the influence of explanatory variables on trip generation over time, including the declining importance of age and gender. The most promising policy actions that could be taken to decrease trip rates would be those that affect a decrease in household automobile ownership, as determined on the basis of the analysis in this paper.
Review of Louisiana's Pavement Management System
Authors: Khattak Mohammad Jamal , Baladi Gilbert Y. , Zhang Zhongjie , Ismail Said
Published: January 2009

“Louisiana–Vision 2020” serves as a benchmark for improving highway pavements over a 20-year period. Cost-effective pavement preservation is emphasized in current Louisiana state law and federal law. The Louisiana Department of Transportation and Development (LADOTD) and the FHWA strategic plans also emphasize cost-effective pavement preservation. In an effort to improve the pavement management system (PMS), the Louisiana Transportation Research Center initiated a two-phase research study to evaluate the overall performance and effectiveness of the system. This paper focuses on the Phase I study and addresses the state-of-the-art practice of LADOTD's PMS and the results of a departmental survey to assess the needs of the various districts. The use of various location reference systems by different units in the department makes linking to different database sets difficult. Although many of the districts’ engineers have no concerns about all the referencing systems, most would prefer to have a unified reference location system. All the districts have access to the PMS data and most of them use it; however, the degree of use varies from one district to another. This paper also discusses the types of PMS output and reports, the degree to which the outputs are analyzed, the accuracy of the information currently available, and the degree to which the current PMS data track and differentiate between different preservation actions.
Rehabilitation Design of Jointed Plain Concrete Pavement
Authors: Titus-Glover Leslie , Stanley Mark
Published: January 2009

Unbonded jointed plain concrete (JPC) overlay is a viable rehabilitation technique for distressed jointed plain concrete pavement (JPCP). The design of unbonded JPC overlays requires performing minimal repairs to the existing JPCP, placement of an asphalt separator layer between the existing portland cement concrete (PCC) layer and the overlay design (determination of overlay PCC thickness), and placement of the overlay. Concrete overlay thickness typically is determined with mechanistic-based design procedures that require a knowledge of existing pavement layer types, thicknesses, and moduli. The existing PCC thickness and elastic modulus can be determined easily through coring and laboratory testing or nondestructive testing by using the falling weight deflectometer. However, establishing an appropriate PCC elastic modulus value that represents the existing damaged pavement is more challenging because coring and deflection testing typically are done on intact (uncracked or deteriorated) PCC material obtained from the sections of the existing JPCP that is in relatively good condition. Therefore, PCC elastic moduli estimated from these sources are not representative of the entire JPCP condition. Various empirical rigid pavement design procedures have been developed for adjusting intact PCC elastic modulus values into a more appropriate damaged PCC elastic modulus for JPCP overlay design. Analysis done to characterize the elastic modulus of damaged, cracked, or shattered PCC slabs based on backcalculated PCC elastic modulus and existing JPCP condition is described.
Robust Pricing of Transportation Networks under Uncertain Demand
Authors: Gardner Lauren M. , Unnikrishnan Avinash , Waller S. Travis
Published: January 2009

Traditionally, tolls on transportation networks are determined on the basis of a single value of travel demand, deterministic elastic demand relationships, or informal scenario analysis. However, since the demand on the network cannot be forecast perfectly, pricing may prove to be suboptimal when the realized value of demand deviates significantly from the planned value. Therefore, there is a need for a robust pricing scheme that accounts for demand uncertainty. Optimal pricing is examined through marginal costs in which origin-destination travel demand is a random variable to understand better the direct impact and sensitivity of the uncertainty. Three methods are evaluated for determining robust prices: inflation or deflation of the planning demand, averaging tolls from various planning demands, and genetic algorithms. The performance of these three methods is evaluated by analyzing user equilibrium for various future travel demand scenarios. From the results of the analysis, a more robust pricing scheme that accounts for variations in demand is developed.
Measurement of Uncertainty Costs with Dynamic Traffic Simulations
Authors: Marchal Fabrice , de Palma André
Published: January 2009

Nonrecurrent congestion in transportation networks occurs as a consequence of stochastic factors affecting demand and supply. Intelligent transportation systems such as advanced traveler information systems and advanced traffic management systems are designed to reduce the impacts of nonrecurrent congestion by providing information to a fraction of users or by controlling the variability of traffic flows. For these reasons, the design of these systems requires a reliable forecast of nonrecurrent congestion. A new method is proposed to measure the impacts of nonrecurrent congestion on travel costs by taking risk aversion into account. The traffic model is based on the dynamic traffic simulation model METROPOLIS. Incidents are generated randomly by reducing the capacity of the network. Users can instantaneously adapt to the unexpected travel conditions or can also change their behavior through a day-to-day adjustment process. Comparisons with incident-free simulations provide a benchmark for potential travel time savings that can be brought about by a state-of-the-art information system. The impact of variable travel conditions is measured by describing the willingness to pay to avoid risky or unreliable journeys. Indeed, for risk-averse drivers, any uncertainty corresponds to a utility loss. This utility loss is computed for several levels of network disruption. The main result of the study is that the utility loss due to uncertainty is of the same order of magnitude as the total travel costs.
Local Calibration of Mechanistic-Empirical Pavement Design Guide for Flexible Pavement Design
Authors: Muthadi Naresh R. , Kim Y. Richard
Published: January 2009

This paper presents the calibration of the Mechanistic-Empirical Pavement Design Guide (MEPDG) for flexible pavements located in North Carolina. Two distress models, permanent deformation and bottom-up fatigue cracking, were used for this effort. A total of 53 pavement sections were selected from the Long-Term Pavement Performance (LTPP) program and the North Carolina Department of Transportation databases for the calibration and validation process. The verification runs for the LTPP sections performed with the parameters developed during the national calibration effort under NCHRP Project 1-37A showed promising results. The Microsoft Excel Solver program was used to fit the predicted rut depth values to the measured values by changing the coefficients in the permanent deformation models for hot-mix asphalt (HMA) and unbound materials. In this process, the sum of the squared errors was minimized for each of the permanent deformation models separately. For the alligator cracking model, the only possibility of reducing the standard error and bias was through the transfer function. Again, the Microsoft Excel Solver program was used to minimize the sum of the squared errors of the measured and the predicted cracking by varying the C1 and C2 parameters of the transfer function. The standard error for the HMA permanent deformation model, as well as that for the alligator cracking model, was found to be significantly less than the global standard error after the calibration. It was decided that both models would be kept for a more robust calibration in the future that would increase the number of sections and include more detailed inputs (mostly Level 1 inputs).
History and Scope of Veterinary Medicine
Authors: Samad MA , Ahmed MU
Published: January 2009

The history of earliest recognition, decline and renaissance of Veterinary Medicine in the world with the brief history of Veterinary Medicine in Indian sub-continent including Bangladesh have been described. It appears from the different reports that with the recommendation of the Joint Indo-American and Pak-American teams on agricultural research and education recommended to establish Agricultural Universities in India and Pakistan where veterinary and agriculture education brought under one umbrella with bifurcation of the complete degree, B.Sc. (Vet. Sci. & AH) into two, DVM (Doctor of Veterinary Medicine) and B.Sc. (AH) as an American education pattern of Land Grant colleges. Out of 22 Veterinary colleges of India, only three Agricultural Universities ( Pantnagar, Haryana and Punjab ) and two in Pakistan (EPAU and WPAU) were implemented the American recommendations. The Indian National Commission on Agriculture has recognized these two separate degrees offered in a profession as detrimental towards livestock development and the Review Committee on Agricultural Universities who recommended an integration of the two degrees to avoid duplication. Accordingly, these two degrees in all the three Indian universities have been combined as BVSc & AH in 1982, and as DVM in 2002 in Pakistan, whereas the Veterinary education has made more complex in Bangladesh through establishment of four Government Veterinary Colleges where offering five years DVM degree including one year internship with combined curricula on animal health and production against four years separate two degrees offering from BAU without internship. Veterinary education should include animal health, animal production and animal product technology for effective teaching, research and extension programme and accordingly, the curricula and syllabi of all the Veterinary degrees offering all over the world have been adjusted except BAU which is urgently required to adjust and reformulate the uniform curricula and syllabi in all the degree offering educational institutes in Bangladesh. Moreover, the history of modern veterinary education in India showed great achievement through establishment of Veterinary University, âTamil Nadu Veterinary and Animal Sciences University' on September 1989. Therefore, there is a strong urge to establish Veterinary University in Bangladesh following the pattern of India. DOI:10.3329/bjvm.v1i1.1909 Bangl. J. Vet. Med. (2008). 1(1): 01-08Â
Clinicopathological Changes of Experimentally Induced Fowl Cholera in Jinding Ducks
Authors: Islam MA , Samad MA , Rahman MB , Kabir SML
Published: January 2009

Clinicopathological changes of duck cholera were studied in 16-week-old 10 susceptible ( PHA titreâ¤8.00 ) Jinding breed ducks during the period from October 2002 to March 2003. Each of the experimental duck was inoculated with a virulent chicken isolate of Pasteurella multocida @ 5.4 x 106 CFU / ml per bird intramuscularly. The incubation period varied from 12 to 48 hours with 100% mortality rate between 24 to 72 hours of infection. These affected ducks showed clinical signs of fever, anorexia, dullness, depression, ruffled feathers, severe weakness, drowsiness, whitish diarrhoea with mucus, exudation from eyes, lameness and unable to hold the head with beak touching the ground before death. Necropsy examination of the dead ducks showed septicaemic conditions, blood vascular congestion, haemorrhagic enteritis, increased amount of pericardial and peritoneal fluids, swollen and sometimes congested liver with multiple necrotic foci on the parietal surface, enlarged and edematous heart with echymotic haemorrhages. Trachea and lungs were severely congested and haemorrhagic and serofibrinous exudates were seen in the lung, liver and heart. The P. multocida organism was reisolated from the swabs of liver and heart of all the dead ducks by standard bacteriological techniques. This study was confirmed the virulence and pathogenicity of chicken isolate of P. multocida in ducks.Key words: Experimental infection; Duck cholera; pathogenicity; clinicopathological changes DOI = 10.3329/bjvm.v1i1.1910 Bangl. J. Vet. Med. (2008). 1(1): 09-13
Pattern of Occurrence of Single and Concurrent Diseases Associated with Mortality in Commercial Chickens in Bangladesh
Authors: Rahman MA , Samad MA
Published: January 2009

The high mortality rate of commercial poultry has been encountered as a major problem which discourage farmers and entrepreneurs in this industry in Bangladesh. This study was carried out to determine the role of single and concurrent infections associated with mortality in 1751 commercial chickens during one year period from January to December 2002. Diagnosis of diseases was made on the basis of history, necropsy findings, isolation and identification of causative bacteria and other laboratory tests. The etiological investigations of 1751 dead chickens showed that about 39.81% bacterial, 22.73% viral, 13.65% mycoplasmal, 1.54% fungal, 10.11% parasitic, 31.64% systemic, 3.43% nutritional deficiency and 1.77% other diseases were associated with these mortality. Salmonellosis (21.99%), Colibacillosis (8.40%), Fowl cholera (6.52%), Avian mycoplasmosis (13.65%), Infectious bursal disease (11.20%), Newcastle disease (10.34%) and coccidiosis (6.23%) were recognized as major diseases associated with mortality in commercial chickens in Bangladesh. About 32 diseases were recorded, of which both single (76.30%) and mixed infections as two (21.53%), three (1.83%) and four (0.34%) types were associated with mortality of chickens. Significantly (p < 0.01) highest proportionate mortality rate was recorded in > 20 weeks old adult layer (45.52%) in comparison to > 2 to 8 weeks old grower (24.04%), > 8 to 20 weeks old pullet (18.16%) and up to 2 weeks old brooding (12.28%) chickens. Seasonal influence showed highest mortality rate during Summer (43.06%) in comparison to Rainy (27.81%) and Winter (29.13%) seasons. It may be concluded from this study that both the single and concurrent infections are associated with high mortality rate in commercial chickens in Bangladesh. Therefore, the interactions of different pathogens in naturally occurring diseases should be considered during diagnosis and evaluation of vaccination.Â Â Key words: Occurrence; concurrent; mortality; diseases; chickens DOI = 10.3329/bjvm.v1i1.1911 Bangl. J. Vet. Med. (2003). 1 (1) : Â 15 - 20
A Retrospective Analysis of Chicken Diseases Diagnosed at The BRAC Poultry Disease Diagnostic Centre of Gazipur
Authors: Saleque MA , Rahman MH , Hossain MI
Published: January 2009

The pattern of occurrence of poultry diseases in commercial poultry farms was studied on post-mortem and other laboratory examinations of 3057 cases either dead or live chickens submitted for diagnosis of diseases at the BRAC Poultry Disease Diagnostic Centre, Gazipur during the two years period from January 2000 to December 2001. Of the 3057 birds obtained, of which diagnosis was confirmed in 79.9% cases and 20.1% remain undiagnosed due to lack of facilities. Highest case of diseases was recorded in breeder (37.2%) followed by broiler (34.9%), and lowest in layer (27.9%) birds. The diagnosed diseases of layers included colibacillosis (7.4%), salmonellosis (25.3%), fowl cholera (7.0%), mycoplasmosis (17.7%), Newcastle disease (8.8%), Gumboro disease (12.4%), coccidiosis (7.2%), GI nematodes (4.6%), GI cestodes (0.6%), egg peritonitis (3.4%), gangrenous dermatitis (0.8%), ascites (0.7%), aspergillosis (2.6%) and omphalitis (1.5%). The broilers (34.9%) and breeders (37.2%) were more or less equally susceptible to various diseases with exception of reproductive diseases. It may be concluded from this study that all age groups and types of chickens are susceptible to various diseases but laying period is most vulnerable, and most mortality of chickens are caused by salmonellosis, colibacillosis, fowl cholera, Gumboro disease, Newcastle disease and mycoplasmosis which demand immediate attention for prevention and control in commercial poultry farms. Key words: Retrospective analysis; diseases; layers; broilers; breeders DOI = 10.3329/bjvm.v1i1.1914 Bangl. J. Vet. Med. ( 2003 ). 1 ( 1 ) : 29 - 31
Diseases Associated with Mortality and Pathological Changes in Cockerel Birds
Authors: Shil GC , Ehsan MA , Rahman MS , Anower AKMM , Islam MR
Published: January 2009

The diseases associated with mortality and pathologic changes were studied in three different cockerel farms in the rural area of Trishal upazilla in Mymensingh district from day-old chicks up to 60 days of marketing during the period from 5th August to 3rd October 2000. Diagnosis of diseases was based on clinical history, characteristic pathological changes and occasionally isolation of the causative agents. The infectious bursal disease (IBD), yolk sac infection, vitamin E deficiency, coccidiosis and others were diagnosed. The mortality rate in cockerels caused by IBD, yolk sac infection, vitamin E deficiency, coccidiosis and others were recorded as 7.29%, 0.62%, 0.72%, 0.21% and 0.10% respectively. The characteristic lesions of IBD were hemorrhage in thigh and pectoral muscles grossly and microscopically the bursa showed dead and pyknotic nuclei of lymphocytes. The typical lesions of yolk sac were thickened with unabsorbed yolk in all chicks grossly and microscopically thickened yolk sac due to fibroblastic proliferation and mononuclear infiltration in association with normal fat cells. The vitamin E deficiency was diagnosed grossly by softened, swollen and focal hemorrhage on the cerebellum and microscopically by proliferation of huge number of glial cells. Grossly coccidiosis was characterized by swollen, thickened, firmer and hemorrhagic caeca and microscopically by hyperplastic, tall columnar epithelial cells contained large number of schizonts and merozoites in the affected crypts and villi. The findings indicate that IBD is the major disease problem in cockerel farming in Mymensingh. Key words: Mortality; diseases; pathological changes; cockerels DOI = 10.3329/bjvm.v1i1.1915 Bangl. J. Vet. Med. (2003). 1 (1) : 33 - 38
Seasonal Influence on The Occurrence of Haemonchus contortus Infection in Slaughtered Black Bengal Goats in Bangladesh
Authors: Shahiduzzaman M , Alim MA , Rahman M , Mondal MMH
Published: January 2009

Seasonal influence on the occurrence of Haemonchus contortus parasite was studied on 672 slaughtered Black Bengal goats during one year period from July 2002 to June 2003. An overall 65.63% goats had H. contortus infection and significantly (p < 0.01) higher infection rate was recorded in female (70.43%) than male (58.61%) goats. A positive correlation between the occurrence of H. contortus infection and climatic factors was recorded. Significantly (p < 0.01) highest infection rate of H. contortus was recorded during rainy (72.57 %) season in comparison to summer (66.46%) and winter (51.54%) seasons. The infection was recorded at the peak in July (84.42%) and lowest in January (46.15%). The load of H. contortus per abomasum varied significantly (p < 0.05) in different months of the year and an average maximum number of parasites per abomasum was recorded in July (41.25) and the minimum in March (5.52). In case of sex ratio of the parasites always the female (60.73%) were found to be dominated over the males (39.27%) parasites.Â  Â Â  Key words: Seasonal influence; Haemonchus contortus; Black Bengal goat; Bangladesh DOI = 10.3329/bjvm.v1i1.1917 Bangl. J. Vet. Med. (2003). 1(1) : 45 - 48
Antibiotic Combined Hyperimmune Serum Therapy for Peste des Petits Ruminants Infected Goats
Authors: Islam MR , Giasuddin M , Rahman MM , Kafi MA
Published: January 2009

The peste des petits ruminants (PPR) has now been recognized as endemic viral disease associated with high morbidity and mortality rates in goats of Bangladesh. As there is no known effective drug against viral diseases, an attempt was made to evaluate the efficacy of antibiotic combined hyperimmune serum therapy (ACHST) against the deadly viral disease, PPR in goats. Naturally PPR infected 128 goats were randomly selected and used for this trial experiment in six different goat farms during the period from March 2001 to July 2003. The distribution of animals were 38 at the BLRI Goat Isolation Shed, Savar, 31 at Military Goat Farm, Savar, 14 at Bangladesh Missionary Farm, Sripur, 11 at the Olympia Goat Farm, Savar, 23 at the Globe Goat Farm, Kaliakoir and 11 at the Islam Nagar Goat Farm, Savar, and each of the selected goat was injected with specific hyperimmune serum @ 10 ml / goat IV daily for 3 days and oxytetracycline @ 1 ml / 10 kg body weight IM twice at 48 hours intervals, which resulted 78.94%, 70.97%, 57.14%, 63.64%, 60.87%, 63.64% and 68.75% recovery rates respectively with an average of 68.75%. The comparative evaluation of ACHST at different stages of naturally PPR infected goats showed highest recovery rate in incubation period (90.63%), followed by prodromal (78.13%), pneumonic (73.33%) and lowest in diarrhoeal (46.93%) phases. It may be concluded from these results that ACHST could be used as therapeutic measures for PPR infected goats. Key words: Goat; PPR; antibiotic; hyperimmune serum; therapy DOI = 10.3329/bjvm.v1i1.1918 Bangl. J. Vet. Med. (2003). 1(1) : 49 - 51