bluuebunny/crossref_metadata_2025 huggingface dataset:
Approaches to Regulating Interchange Fees in Payment Systems
Authors: Gans Joshua S , King Stephen P.
Published: November 2009

Significant attention worldwide has been paid to the regulation of credit card interchange fees. In part, this attention has followed concerns expressed about the level of these fees in Europe, the U.S. and Australia. The Reserve Bank of Australia recently conducted an extensive inquiry into the interchange fees associated with credit cards and has moved to regulate those fees. At the same time, research economists have considered determinants of the socially optimal interchange fee. In this paper, we use the Australian experience to highlight alternative methods of regulating interchange fees in payments systems. We use a simple model to derive a socially optimal interchange fee when merchants cannot freely set different prices for different payment instruments. We compare the socially optimal interchange fee from this model with those presented in the economics literature and show that most analyses capture a simple externality within the optimal fee. Credit card usage for a specific transaction is determined by the customer. But the customer does not bear the costs or receive the benefits that card usage imposes on the merchant. The optimal interchange fee internalises this externality. We then compare the theoretical optimal interchange fee with the approaches proposed in Australia, and show that the regulatory approach adopted by the Reserve Bank of Australia may be viewed as economically conservative in certain situations. Finally, we consider additional issues that will impinge on the regulation of interchange fees.
Incentive Regulation in Network Industries: Experience and Prospects in the U.S. Telecommunications, Electricity, and Natural Gas Industries
Authors: Hemphill Ross C. , Meitzen Mark E. , Schoech Philip E.
Published: November 2009

We trace the development of incentive regulation in the U.S. telecommunications, electricity, and natural gas industries. Telecom has moved much more in the direction of pure price cap regulation. Incentive regulation in electricity and gas has generally not strayed far from rate-ofreturn regulation. Reasons for these differences include differences in regulatory commitment, industry concentration, technological change and productivity growth, service quality concerns, and externalities. We conclude that electricity and gas can evolve to purer forms of price caps as they gain more experience with incentive regulation, and if the unique features of these industries are considered in plan design.
The Governance Structure of Ports
Authors: Brooks Mary R.
Published: November 2009

The recent worldwide trend towards devolution in the port industry has spawned considerable variety in the types of governance structures now in place around the world. This paper discusses the range of devolution alternatives adopted in the global ports sector, as identified by the World Bank and academic researchers. It then examines the Canadian model more closely as it attempts to follow a more novel path, that of the not-for-profit organization.
United States Demand for Internet Access
Authors: Savage Scott J. , Waldman Donald M.
Published: November 2009

This study uses survey data from 2003 to empirically assess United States residential demand for Internet access. Econometric results indicate that service reliability, speed, and the ability to share music and video files are highly valued Internet access attributes. The latter finding suggests commercial development of online file sharing services has potential to generate substantive network effects for access providers, hardware manufacturers, software and content providers. Legal and reimbursement issues need to be resolved between interested telecommunications parties and the entertainment industry to realize these gains in the future.
Congestion Charging: Challenges to Meet the UK Policy Objectives
Authors: Blythe Philip T.
Published: November 2009

This paper reviews and comment on the current issues of road-use charging in the UK from two perspectives, the technical and the political. The paper concludes that the lack of appropriate technology will not be the constraint in implementing road-use charging in the near future in the UK, and new technologies that are currently being researched should not be excluded as possible future solutions for charging. However the local authority schemes that are now up and running in London and Durham, the on-going National Trials in Leeds, the policy of introducing distancebased charging for Heavy Goods Vehicles and the Commission for Integrated Transports proposal to have distance-charging black-boxes in all UK registered vehicles suggests certain policy divergence which may be difficult to "sell" to the public.
Structural Separation to Create Competition? The Case of Freight Railways
Authors: Pittman Russell
Published: November 2009

The freight railways sector has three attributes that have proved problematic for recent experiments with vertical separation: a) a relatively high share of network costs in total delivered service costs, b) an apparent persistence of economies of scale at the "competitive" train operations level, and, perhaps most important, c) strong economies of vertical integration that are focused on the interface point of wheel and rail  that is, exactly where vertical separation takes place. The third factor in particular seems a clear illustration of the rationales discussed by Coase and Williamson for the broad vertical scope of a single firm and the disadvantages of relying on market transactions under certain conditions.
Assessing Australian Interchange Regulation: Comments on Chang, Evans and Garcia Swartz
Authors: Farrell Joseph
Published: November 2009

In this short comment, I provide my views on "The Effect of Regulatory Intervention in Two-Sided Markets: An Assessment of Interchange-Fee Capping in Australia" (published in this issue) that was presented at the Antitrust Activity in Card-Based Payment Systems: Causes and Consequences conference.
Telecommunications Policies: Measurement and Determinants
Authors: Gual Jordi , Trillas Francesc
Published: November 2009

This paper presents new data on telecommunications reform for a cross section of countries. We measure telecommunications reform along two dimensions: entry barriers and regulatory independence. This data set is combined with a comprehensive set of performance, institutional and political data to analyze the determinants of telecommunications policies. We find that entry barriers are positively associated with the degree to which countries have an interventionist legal tradition, but they are unrelated to the partisan ideology of reforming governments. We also find that countries with weak protection of investors' quasi-rents by other means, and countries with a larger incumbent, are more prone to create independent regulatory agencies, although the latter is a weaker result.
The Coordination Problem in a Structural Model of Peak-Period Congestion: An Experimental Study
Authors: Gabuthy Yannick , Neveu Matthieu , Denant-Boemont Laurent
Published: November 2009

The purpose of our paper is to generalize the model by Arnott et al. (1990a) to situations with a single origin and destination connected by two routes and to test the analytical results in an experiment with discrete time departure choices. The experimental evidence does not support the theoretical predictions: While the accumulated experience creates significant learning effects which imply a positive evolution of the empirical travel costs towards the equilibrium, the Nash hypothesis is still rejected and the commuting system shows substantial fluctuations until the end of the experiment.
Fulfilled-expectations Equilibria in Network Demand
Authors: Kate Adriaan Ten , Niels Gunnar
Published: November 2009

Static demand models for homogeneous network goods give rise to fulfilled-expectations equilibrium demand (FEED) curves, which, contrary to normal demand curves, may be upward sloping at certain intervals. We analyze some, as yet unexplored, properties of the FEED curves. We spell out the one-shot non-cooperative game, the Nash equilibria of which constitute the FEED curve. We show that, in a network environment, pricing below marginal cost may be required to reach critical mass, and competition could represent an obstacle to network development rather than being its driving force.
Multi-Hub Network Configurations - A Temporary or Permanent Outcome of Airline Consolidation?
Authors: Düdden Jan-Christoph
Published: November 2009

Ongoing consolidation in the European airline industry poses a threat to second-tier hub cities in terms of losing hub status and long haul routes. As airlines merged in the USA, it was often more efficient to close a duplicating hub and concentrate resources on the stronger one. This paper relies on a formal model to explore discrete scenarios for non-hub intercontinental connections. The results of the analysis show that a hub and spoke airline in a competitive environment can rationally preserve or initiate non-hub long haul routes, even going to the length of maintaining or building up an ancillary hub.
Payment Network Scale Economies, SEPA, and Cash Replacement
Authors: Bolt Wilko , Humphrey David
Published: November 2009

The goal of SEPA (Single Euro Payments Area) is to facilitate the emergence of a competitive, intra-European market by making cross-border payments as easy as domestic transactions. With cross-border inter-operability for electronic payments, card transactions will increasingly replace cash and checks for all types of payments. Using different methods, we estimate card and other payment network scale economies for Europe. These indicate substantial cost efficiency gains if processing is consolidated across borders rather than "piggy-backed" onto existing national operations. Cost reductions likely to induce greater replacement of small value cash transactions are also illustrated.
Recent Changes in the Spanish Rail Model: the Role of Competition
Authors: Campos Javier
Published: November 2009

After a brief historical overview of its main achievements, this paper examines some of the most relevant characteristics of the Spanish rail system and its performance in recent years. It particularly focuses on the new organizational model emerging from the 2003 Railroad Law which, after January 2005, introduced vertical separation and competition in the traditional monopolistic structure of this sector. Although it is early to fully evaluate the results of this change, some interesting lessons can be learnt for countries following the same model.
Charging for Scarce Rail Capacity in Britain: A Case Study
Authors: Johnson Daniel , Nash Chris
Published: November 2009

The aim of this paper is to examine the feasibility of identifying an appropriate rail scarcity charge which would make operators pay for their use of rail capacity in line with the opportunity cost of the use of these slots and to give some idea of the likely effects of such charges. The way in which we do this is to use a passenger demand forecasting model, PRAISE, to consider a situation on the East Coast Main Line which is characterized by scarce capacity and a degree of competition.
The Shellpot Bridge: A Public/Private Partnership That Worked
Authors: Resor Randolph R. , Blaze James R. , Campbell David W.
Published: November 2009

The Shellpot Bridge is a 536-foot swing bridge located on a rail freight bypass route around Wilmington, Delaware. When the bridge failed in 1994, Conrail, then the bridges owner, elected not to repair it due to declining freight volume. The State of Delaware reached agreement with the new rail owner, Norfolk Southern Corporation, to provide funds to repair the bridge, with the railroad to pay tolls to repay the states investment. Recent volumes of traffic over the bridge indicate that, if traffic continues at its current level, Delaware will realize an annual return of 9.75% on its investment.
The Interaction between Tolls and Capacity Investment in Serial and Parallel Transport Networks
Authors: Borger Bruno De , Dunkerley Fay , Proost Stef
Published: November 2009

The purpose of this paper is to compare price and capacity competition in simple serial and parallel transport networks, where individual links are operated by different authorities. We find more tax exporting in serial transport corridors than on parallel road networks. The inability to toll transit has quite dramatic negative welfare effects on parallel networks; in serial transport corridors, it may actually be undesirable to allow the tolling of transit at all. Finally, if the links are exclusively used by transit transport, toll and capacity decisions are independent in serial networks. When regions compete for transit in a parallel setting, higher regional capacity implies lower Nash equilibrium tolls.
Subadditivity Tests for Network Separation with an Application to U.S. Railroads
Authors: Ivaldi Marc , Mccullough Gerard
Published: November 2009

We describe a pair of empirical tests that can be used to evaluate the technological feasibility of separating a vertically integrated network monopoly into a common infrastructure component and competing operating components. We implement the tests with a Generalized McFadden cost function that is globally concave in input prices and permits the assignment of zero output values without losing its flexibility properties. The tests shed light on the respective roles of regulation and competition policy. We illustrate them with an analysis of U.S. freight railroads for the period 1978-2001 and find both vertical and horizontal economies of scope.
Access Pricing, Bypass and Universal Service in Post
Authors: Armstrong Mark
Published: November 2009

A postal regulator typically faces two issues which make the design of efficient access pricing especially difficult and which complicate the process of liberalizing the industry. First, universal service obligations, together with the presence of fixed costs, require retail prices to depart from the underlying marginal costs of the incumbent provider. Second, competing firms may be able to bypass the incumbent's delivery network. Within a simple and stylized framework, this note analyzes how access charges should best be set in the light of these twin constraints.
Worksharing: A Calibrated Model
Authors: De Villemeur Etienne Billette , Cremer Helmuth , Boldron Francois , Roy Bernard
Published: November 2009

This paper studies the price structure in a postal sector with a monopolistic operator when customers can engage in worksharing. It presents simulation results obtained from an empirical model that is calibrated on data from the French postal sector. The optimal worksharing discount is significantly larger than the avoided costs. Consequently, the appropriate pricing structure differs markedly from the often recommended ECPR policy.
Delivery Offices Cost Frontier: A Robust Non Parametric Approach with Exogenous Variables
Authors: Cazals Catherine , Dudley Paul , Florens Jean-Pierre , Patel Shital , Rodriguez Frank
Published: November 2009

This paper deals with an analysis of the efficiency of delivery post offices from an estimated cost frontier. Our focus is to apply a robust non parametric approach for the cost frontier estimation, called the order-m frontier, based on the concept of "expected minimum cost" and to extend it to take into account some environmental variables. We illustrate our approach using a cross-section data set on delivery offices.
Reforming Telecom Regulation: An Essay Review of Nuechterlein and Weiser's Digital Crossroads
Authors: Schwartz Marius
Published: November 2009

The U.S. telecom industry has long been evolving from regulated monopoly to competition in various services such as telephony and video. This trend is accelerating with the spread of digital transmission and the Internet. Digital Crossroads provides a timely and sweeping treatment of the entire industry, focusing on the interaction between regulatory policy and competition  lessons from the past, and the challenges ahead. This essay review synthesizes and extends the book's contributions around two central policy prescriptions: adopt a high intervention threshold before mandating "nondiscriminatory" access to perceived bottleneck facilities, and eliminate a host of outdated and arbitrary regulatory distinctions.
Editors' Foreword
Authors: Weisman Dennis L. , Tardiff Timothy J.
Published: November 2009

This special issue of the Review of Network Economics is dedicated to celebrating the achievements of Professor Alfred Kahn in commemoration of his 90th; birthday. The articles in this special issue examine a range of topics in the economics of regulation, antitrust and public policy, as applied to the telecommunications, electric power, railroad and airline industries. And in the spirit of the man himself, these articles are motivated by real-world problems, "rigorous" and yet accessible to policymakers and practitioners alike.
Incentive Regulation and Its Application to Electricity Networks
Authors: Joskow Paul L.
Published: November 2009

This paper examines developments since the publication of The Economics of Regulation in the theory of incentive regulation and its application to the regulation of unbundled electricity transmission and distribution networks. Conceptual mechanism design issues that arise when regulators are imperfectly informed and there is asymmetric information about costs, managerial effort, and quality of service are discussed. The design and application of price cap mechanisms and related quality of service incentives in the UK are explained. The limited literature that measures the effects of incentive regulation applied to electricity networks is reviewed.
Exporting Deregulation - Alfred Kahn and the Celtic Tiger
Authors: Barrett Sean D.
Published: November 2009

Airline deregulation in Ireland arose from a parliamentary revolt in 1984 against legislation to imprison and fine those selling airline tickets below government approved fares. The revolt was heavily influenced by US airline deregulation in 1978 and the writings of Alfred Kahn. The results were spectacular. Dublin-London, deregulated in 1986, became the busiest international route in Europe. The 2.2m passengers on the Irish national airline before deregulation in 1986 increased to 72m passengers on four Irish airlines in 2008. Ryanair redefined the European aviation. The success of airline deregulation had a major influence on Irish economic policy.
Introduction to a Special Issue on Network Neutrality
Authors: Schwartz Marius , Weiser Philip J.
Published: November 2009

"Network neutrality" encompasses a wide-ranging debate over what limits, if any, should be placed on network providers in pricing or managing Internet traffic. The articles in this volume tackle various aspects of this debate: Have other transportation networks been truly "neutral"? Should broadband providers be allowed to charge content providers for connecting with end users? How much price discrimination is appropriate and is it confined to network operators? How large are the potential costs of constraining traffic management practices? What are the tradeoffs from mandated loop unbundling to deter discrimination and what market power threshold justifies interventions?
A Sensible Next Step on Network Neutrality: The Market Power Question
Authors: Speta James B.
Published: November 2009

Two years ago, disagreement on network neutrality stalled momentum to reform the aging Communications Act. Significantly, both sides of the debate have become hardened, in part because of differing views on the market power of Internet access providers and their ability to foreclose competition. However, neither the FCC nor other government authorities have taken a position on the matter, even in the FCCs recent network neutrality adjudication. This essay proposes a way forward, by immediately adopting "truth-in-advertising" and "no-blocking" rules and by beginning a comprehensive, rigorous inquiry into the state of the broadband market  starting with the market power question.
Is Protecting Sunk Investments by Consumers a Key Rationale for Natural Monopoly Regulation?
Authors: Biggar Darryl
Published: November 2009

Why regulate natural monopolies? Conventional economic theory points to the price-marginal cost margin and the ensuing deadweight loss. But this hypothesis does a poor job of explaining the way that regulators behave in practice. This paper proposes an alternative hypothesis: that natural monopoly regulation exists to protect the sunk investments made by consumers of the regulated firm. This hypothesis explains many of the practices of regulators which make little or no sense under conventional economic theory, such as the desire to pursue stable prices, the aversion to Ramsey pricing, and the role of incremental cost as a pricing floor.
Time Consistency in Regulatory Price Setting: An Australian Case Study
Authors: Ergas Henry
Published: November 2009

Time consistency refers to situations where a policy that is optimal ex ante proves not to be optimal ex post, creating the risk of opportunistic policy reversals. While the threat of such reversals has received widespread attention in the theoretical literature, testing whether policy is indeed time consistent is challenging. This paper implements such a test by comparing the depreciation profile established by the Australian telecommunications regulator at the outset of a regulatory period with the actual path of allowed recovery, and finds that the regulator acted in a time-inconsistent manner.
The Elasticity Pricing Rule for Two-sided Markets: A Note
Authors: Krueger Malte
Published: November 2009

Rochet and Tirole have derived an elasticity rule for relative prices in two-sided markets. This rule is seen as counterintuitive because it seems to imply that the "more elastic side of the market" is charged more. In this note it is argued that this interpretation is based on the assumption that elasticity of demand can be treated as a parameter. If elasticity is treated as function of price, the Rochet-Tirole rule is perfectly in line with economic intuition.
How Little We Know
Authors: Roberts Russell
Published: November 2009

If only preventing financial crashes were as straightforward as preventing airline crashes. Russell Roberts explains the implications for future financial reform.
Rapid Detection Techniques for Biological and Chemical Contamination in Food: A Review
Authors: Tang Yali , Lu Lixin , Zhao Wei , Wang Jun
Published: November 2009

The contamination problem in food safety is still a major concern not only for developing countries but also for the industrialized world. To guarantee the food safety, the advanced examination technique is needed urgently. However, the traditional methods have some typical drawbacks which include: high costs of implementation, long time of analysis and low samples throughput, and the need for high qualified manpower. The availability of fast, reliable and simple to use detecting tools for food products is therefore a target both for the safeguard of customer's health and production improvement. This article overviews the progress of the rapid detection methods for biological and chemical contamination in food.
Examination of the Professional Self-Esteem of Teacher Candidates Studying at a Faculty of Education
Authors: Aral Neriman , Gürsoy Figen , Ceylan Remziye , Biçakçi Müdriye Yildiz
Published: November 2009

This study aims to determine the professional self-esteem levels of teacher candidates studying at the Faculty of Education, Ahi Evran University, Kırşehir, Turkey, to examine whether certain variables create any differences in their professional self-esteem levels and to propose suggestions in accordance with the results. The study was conducted among first- and fourth-year students. Data about the participants was collected through the use of a general information form, and their self-esteem levels were evaluated through the Scale for Professional Self-Esteem developed by Arıcak. The results reveal that gender, grade level, credit given to the importance of teaching as a profession, the ranking of choosing teaching as a profession at university and participating in professional activities in teaching do not cause any differences in teacher candidates' self-esteem levels, yet the activities of lecturers with regard to the reputation of teaching cause differences in their self-esteem levels.
Quantity and Quality of Sleep and Incidence of Type 2 Diabetes
Authors: Cappuccio Francesco P. , D'Elia Lanfranco , Strazzullo Pasquale , Miller Michelle A.
Published: November 2009

OBJECTIVE

To assess the relationship between habitual sleep disturbances and the incidence of type 2 diabetes and to obtain an estimate of the risk.

RESEARCH DESIGN AND METHODS

We conducted a systematic search of publications using MEDLINE (1955–April 2009), EMBASE, and the Cochrane Library and manual searches without language restrictions. We included studies if they were prospective with follow-up >3 years and had an assessment of sleep disturbances at baseline and incidence of type 2 diabetes. We recorded several characteristics for each study. We extracted quantity and quality of sleep, how they were assessed, and incident cases defined with different validated methods. We extracted relative risks (RRs) and 95% CI and pooled them using random-effects models. We performed sensitivity analysis and assessed heterogeneity and publication bias.

RESULTS

We included 10 studies (13 independent cohort samples; 107,756 male and female participants, follow-up range 4.2–32 years, and 3,586 incident cases of type 2 diabetes). In pooled analyses, quantity and quality of sleep predicted the risk of development of type 2 diabetes. For short duration of sleep (≤5–6 h/night), the RR was 1.28 (95% CI 1.03–1.60, P = 0.024, heterogeneity P = 0.015); for long duration of sleep (>8–9 h/night), the RR was 1.48 (1.13–1.96, P = 0.005); for difficulty in initiating sleep, the RR was 1.57 (1.25–1.97, P < 0.0001); and for difficulty in maintaining sleep, the RR was 1.84 (1.39–2.43, P < 0.0001).

CONCLUSIONS

Quantity and quality of sleep consistently and significantly predict the risk of the development of type 2 diabetes. The mechanisms underlying this relation may differ between short and long sleepers.
Association of Lower Plasma Fetuin-A Levels With Peripheral Arterial Disease in Type 2 Diabetes
Authors: Eraso Luis H. , Ginwala Naeema , Qasim Atif N. , Mehta Nehal N. , Dlugash Rachel , Kapoor Shiv , Schwartz Stanley , Schutta Mark , Iqbal Nayyar , Mohler Emile R. , Reilly Muredach P.
Published: November 2009

OBJECTIVE

Fetuin-A is an inhibitor of vascular calcification and a mediator of insulin resistance. This study evaluated the association of plasma fetuin-A and peripheral arterial disease (PAD).

RESEARCH DESIGN AND METHODS

A total of 738 individuals with type 2 diabetes (mean age 58.7 years, 37.1% female) without known cardiovascular or kidney disease were included in this cross-sectional analysis.

RESULTS

Subjects with PAD had a significantly lower fetuin-A (264.3 vs. 293.4 ng/dl, P < 0.001). In multivariable analysis, a 1-SD decrease in fetuin-A increased the odds of PAD (odds ratio 1.6, P = 0.02). Subgroup analysis revealed an increased odds even in subjects with glomerular filtration rate >80 (odds ratio 1.9, P = 0.05) or high-sensitivity C-reactive protein <3 mg/dl (odds ratio 2.7, P = 0.002).

CONCLUSIONS

Lower circulating fetuin-A is associated with PAD in type 2 diabetes beyond traditional and novel cardiovascular risk factors. Our findings suggest a potentially unique role for fetuin-A deficiency as a biomarker of PAD in patients with type 2 diabetes.
Effectiveness of an epidural blood patch for patients with intracranial hypotension syndrome and persistent spinal epidural fluid collection after treatment
Authors: Horikoshi Toru , Watanabe Arata , Uchida Mikito , Kinouchi Hiroyuki
Published: November 2009

Object

Magnetic resonance imaging may show a fluid collection in the spinal epidural space of patients with spontaneous intracranial hypotension syndrome (SIHS), but the chronological changes remain unclear.

Methods

Brain and spine MR imaging findings were analyzed in 16 patients (9 women and 7 men, mean age 48.6 years) with SIHS before and after treatment.

Results

Diffuse dural enhancement was seen in 15 patients, and the epidural fluid collection in the spinal canal was clear in 15 and equivocal in 1. Symptoms disappeared after bed rest in 1 patient, and an epidural blood patch was performed in 15 patients, resulting in complete resolution of symptoms in 13. After the follow-up period (range 1–20 months, mean 5.0 months), 1 patient had persistent mild headache that gradually worsened in the afternoon, and another patient complained of heaviness of the eyes. Follow-up MR imaging demonstrated disappearance of the dural enhancement in all patients, but a fluid collection in the spinal canal remained in 4. Two of the 4 patients had persistent symptoms, but the other patients exhibited complete resolution of the symptoms.

Conclusions

An epidural blood patch is effective for sealing of CSF leaks, but the resolution of SIHS-related symptoms does not always imply complete eradication of the leakage.
Intracellular free magnesium of brain and cerebral phosphorus-containing metabolites after subarachnoid hemorrhage and hypermagnesemic treatment: a 31P–magnetic resonance spectroscopy study
Authors: Wong George K. C. , Yeung David K. W. , Ahuja Anil T. , King Ann D. , Lam Christopher W. K. , Chan Matthew T. V. , Gin Tony , Poon Wai S.
Published: November 2009

Object

Disturbance of cerebral phosphorus-containing metabolites occurs in many disease entities and has not been widely studied in patients with subarachnoid hemorrhage (SAH). Pilot studies have indicated that hypermagnesemic treatment may improve outcome in patients with aneurysmal SAH, but the precise mechanism is not known. The authors hypothesized that, by raising intracellular brain free magnesium in aneurysmal SAH, hypermagnesemic treatment would alter the cerebral energy status.

Methods

The authors designed the current study to use 31P-MR spectroscopy (MRS) to investigate intracellular brain free magnesium and cerebral phosphorus-containing metabolites in patients with good-grade aneurysmal SAH, both those receiving and not receiving hypermagnesemic therapy. A total of 37 eligible patients and 23 healthy volunteers were recruited. A total of 81 MRS studies were performed.

Results

Hypermagnesemic treatment after aneurysmal SAH produced a small (mean difference 0.018 ± 0.007 mM [+ 13.0%]) but significant elevation of intracellular free magnesium during the 1st week. Aneurysmal SAH produced a depressed membrane metabolism with lower phosphodiester/total phosphate.

Conclusions

The MRS finding of elevated brain free intracellular magnesium after intravenous magnesium sulfate infusion is novel, and the changes in membrane metabolism provide insight into the metabolic effects of aneurysmal SAH and future pathophysiological studies.
Cerebrospinal fluid shunt insertion: techniques of peritoneal catheter placement separate from abdominal fascial and peritoneal incisions
Authors: Elashaal Abdurrahim A. , Corrin Michael , Cusimano Michael D.
Published: November 2009

Good abdominal wall closure is one of the basic surgical skills and is a common feature of almost all modernday CSF shunt operations. The fact that some patients require multiple abdominal operations highlights the need for a simple and effective technique for peritoneal catheter insertion through the abdominal wall and abdominal wall closure. Although technically simple, abdominal wall closure becomes more complex when combined with the requirement to maintain CSF shunt function in cases in which the shunt catheter passes through the abdominal wall into the peritoneal cavity. In this report, the authors describe a simple technique for passing the peritoneal catheter of a ventriculoperitoneal shunt through the abdominal wall on a pathway separate from the fascial opening. This technique minimizes the risk of abdominal wall–related complications and is especially important in high-risk patients such as those with obesity and/or diabetes and in children.
Islamic Resistance in Palestine: Hamas, the Gaza War and the Future of Political Islam
Authors: Seif Da'na
Published: November 2009

The significant events stirring the Middle East can hardly be comprehended without recognising and conceptualising the considerable cultural transformations in the region. Hamas' electoral victory in January 2006 in Palestine, Hizbullah's political and military victory in Lebanon in the July war of the same year, and the instantaneous initiation of Iraqi resistance in April 2003 following the American invasion are neither isolated nor random events but events that require explanation. This paper examines the ‘New Islamic Phenomenon’, the latest reinvention of Islam and the corresponding new trend in political Islam, focusing primarily on the rise of Hamas, in order to explain the region's cultural transformations and consider the future trajectory of political Islam following Israel's war on Gaza. This article sharply distinguishes the new Islamic movements, politically and theologically, from other fundamentalist orientations and agues that the new trend in Islam represents both the new Arab nationalism and a major endeavour in Islamic intellectual and theological renewalism.
The Swedish Canard – not only Smoke, but also Fire: Letter from Zurich
Authors: Elam Shraga
Published: November 2009

On 17 August 2009 the Swedish tabloid Aftonbladet published an article by Swedish journalist and photographer Donald Boström, entitled: ‘Våra söner plundras på sina organ’ (‘Our sons are plundered of their organs’),1 claiming to expose a human organ trafficking ring involving soldiers in the Israeli army abducting Palestinians to harvest their organs. Boström linked this alleged ring to charges against Levy Izhak Rosenbaum of Brooklyn, arrested for conspiring to arrange the sale of an Israeli citizen's kidney. The article prompted outrage in both Sweden and Israel, with accusations of anti-Semitism and blood libel against Jews levelled against Boström and Aftonbladet.
First Report of Colletotrichum acutatum on Mangifera indica in Sri Lanka
Authors: Jayasinghe CK , Fernando THPS
Published: November 2009

Colletotrichum acutatum is known to have a wide host range and has become an increasingly important pathogen on many economic crops worldwide. This is the first report of Colletotrichum acutatum on mango in Sri Lanka. Colletotrichum gloeosporiodes together with C. acutatum are considered as causal agents of this disease. Colletotrichum acutatum was characterized by fusiform conidia and white to orange colonies with slight shades of light mouse grey aerial mycelia. Colletotrichum gloeosporioides produced grey colonies with a dark mouse grey centre and conidia were cylindrical. The other differences between the mango isolate of C. acutatum and C. gloeosporioides were the slower growth rate and extremely high tolerance of C. acutatum to the fungicide carbendazim. Key words: Colletotrichum gloeosporioides, Hevea brasiliensis, carbendazim DOI: 10.4038/cjsbs.v38i1.1326 Cey. J. Sci. (Bio. Sci.) 38 (1): 31-34, 2009
Recruitment of Sprouty1 to Immune Synapse Regulates T Cell Receptor Signaling
Authors: Lee Jun Sung , Lee Ji Eun , Oh Yu Mi , Park Jong Bae , Choi Heonsik , Choi Chung Yeon , Kim In-Hoo , Lee Seung Hoon , Choi Kyungho
Published: November 2009

TCR stimulation not only initiates positive signals for T cell activation, but also induces negative signals that down-regulate T cells. We previously reported that Sprouty1, a negative regulator of Ras-MAPK pathway of receptor tyrosine kinases, was induced by TCR signal and inhibited TCR signaling in CD4+ T cell clones. In this study, we addressed the mechanism underlying Sprouty1 inhibition of T cells. When overexpressed in Jurkat T cells, Sprouty1 inhibited TCR signal-induced IL-2 transcription, and also AP-1, NFAT, and NF-κB activation, which suggests that Sprouty1 acts at proximal TCR signalosome. Accordingly, we found that Sprouty1 translocated to immune synapse upon TCR engagement in both Jurkat cells and activated primary T cells and interacted with various signaling molecules in the TCR signalosome, such as linker for activation of T cells (LAT), phospholipase C-γ1 (PLC-γ1), c-Cbl/Cbl-b, and HPK1. Sprouty1 inhibited LAT phosphorylation, leading to decreased MAPK activation and IL-2 production. Deletion of C-terminal 54 amino acids in Sprouty1 abolished its inhibitory effect and this deletion mutant was unable to translocate to immune synapse and interact with LAT. Overall, our data suggest that Sprouty1 induced by TCR signal negatively regulates further TCR signaling by interacting with proximal signaling molecules in immune synapse, providing a novel regulatory mechanism of T cells.
Autophagic Compartments Gain Access to the MHC Class II Compartments in Thymic Epithelium
Authors: Kasai Michiyuki , Tanida Isei , Ueno Takashi , Kominami Eiki , Seki Sachiko , Ikeda Tohru , Mizuochi Toshiaki
Published: November 2009

The presentation of self-peptides in the context of MHC molecules by thymic epithelial cells (TECs) is essential for T cell repertoire selection in the thymus. However, the underlying mechanisms of this process have not been fully elucidated. To address whether autophagy, a catabolic process involving the degradation of a cell’s components through the lysosomal machinery, intersects the MHC class II-restricted Ag presentation pathway in TECs, we investigated the colocalization of LC3, a peculiar autophagy marker molecule, with MHC class II compartments in in vitro-established TEC lines by immunofluorescence microscopy and Western blotting analyses. We found that in both cortical and medullary TEC lines, LC3 was colocalized with the H2-DM-positive lysosomal compartments, in which MHC class II plus class II-associated invariant chain peptides complexes are formed. Furthermore, our analysis of thymic cryosections from 1-day-old mice revealed that LC3 colocalizes with the H2-DM-positive compartments in TECs. These results strongly suggest that the cytoplasmic self-Ags gain access to the H2-DM-positive compartments via the autophagic process in the thymus.
Mast Cell Differentiation and Activation Is Closely Linked to Expression of Genes Coding for the Serglycin Proteoglycan Core Protein and a Distinct Set of Chondroitin Sulfate and Heparin Sulfotransferases
Authors: Duelli Annette , Rönnberg Elin , Waern Ida , Ringvall Maria , Kolset Svein O. , Pejler Gunnar
Published: November 2009

Serglycin (SG) proteoglycan consists of a small core protein to which glycosaminoglycans of chondroitin sulfate or heparin type are attached. SG is crucial for maintaining mast cell (MC) granule homeostasis through promoting the storage of various basic granule constituents, where the degree of chondroitin sulfate/heparin sulfation is essential for optimal SG functionality. However, the regulation of the SG core protein expression and of the various chondroitin sulfate/heparin sulfotransferases during MC differentiation and activation are poorly understood. Here we addressed these issues and show that expression of the SG core protein, chondroitin 4-sulfotransferase (C4ST)-1, and GalNAc(4S)-6-O-sulfotransferase (GalNAc4S6ST) are closely linked to MC maturation. In contrast, the expression of chondroitin 6-sulfotransferase correlated negatively with MC maturation. The expression of N-deacetylase/N-sulfotransferase (NDST)-2, a key enzyme in heparin synthesis, also correlated strongly with MC maturation, whereas the expression of the NDST-1 isoform was approximately equal at all stages of maturation. MC activation by either calcium ionophore or IgE ligation caused an up-regulated expression of the SG core protein, C4ST-1, and GalNAc4S6ST, accompanied by increased secretion of chondroitin sulfate as shown by biosynthetic labeling experiments. In contrast, NDST-2 was down-regulated after MC activation, suggesting that MC activation modulates the nature of the glycosaminoglycan chains attached to the SG core protein. Taken together, these data show that MC maturation is associated with the expression of a distinct signature of genes involved in SG proteoglycan synthesis, and that MC activation modulates their expression.
Interplay between Chromatin Remodeling and Epigenetic Changes during Lineage-Specific Commitment to Granzyme B Expression
Authors: Juelich Torsten , Sutcliffe Elissa , Denton Alice , He Yiqing , Doherty Peter C. , Parish Christopher , Turner Steven J. , Tremethick David , Rao Sudha
Published: November 2009

The role of chromatin remodeling and histone posttranslational modifications and how they are integrated to control gene expression during the acquisition of cell-specific functions is poorly understood. We show here that following in vitro activation of CD4+ and CD8+ T lymphocytes, both cell types show rapid histone H3 loss at the granzyme B (gzmB) proximal promoter region. However, despite the gzmB proximal promoter being remodeled in both T cell subsets, only CD8+ T cells express high levels of gzmB and display a distinct pattern of key epigenetic marks, notably differential H3 acetylation and methylation. These data suggest that for high levels of transcription to occur a distinct set of histone modifications needs to be established in addition to histone loss at the proximal promoter of gzmB.
Absence of the Transcriptional Repressor Blimp-1 in Hematopoietic Lineages Reveals Its Role in Dendritic Cell Homeostatic Development and Function
Authors: Chan Yueh-Hsuan , Chiang Ming-Feng , Tsai Yueh-Chiao , Su Shin-Tang , Chen Ming-Hsu , Hou Mau-Sheng , Lin Kuo-I
Published: November 2009

Dendritic cells (DCs) are important for the initiation and regulation of immune responses. In this study, we demonstrate that DC homeostatic development in peripheral lymphoid organs is negatively regulated by the transcriptional repressor, Blimp-1, which is critical for regulation of plasma cell differentiation and T cell homeostasis and function. Deletion of Prdm1, the gene encoding Blimp-1, in mouse hematopoietic lineages resulted in an increase in the steady-state number of conventional DCs (cDCs). Specifically, Prdm1 deletion increased immediate CD8− cDC precursors in peripheral lymphoid organs, causing selective expansion of the CD8− cDC population. Upon stimulus-induced maturation, Blimp-1 was up-regulated in bone marrow-derived DCs via the p38 MAPK and NF-κB pathways. Notably, Blimp-1-deficient DCs matured poorly upon stimulation in vitro and in vivo. Blimp-1 binds to the proinflammatory cytokine/chemokine genes, Il-6 and Ccl2, and negatively regulates their expression. Collectively, our findings reveal two new roles for Blimp-1: negative regulation of a select subset of cDCs during homeostatic development, and enhancement of DC maturation.
A Nonadjuvanted Polypeptide Nanoparticle Vaccine Confers Long-Lasting Protection against Rodent Malaria
Authors: Kaba Stephen A. , Brando Clara , Guo Qin , Mittelholzer Christian , Raman Senthilkumar , Tropel David , Aebi Ueli , Burkhard Peter , Lanar David E.
Published: November 2009

We have designed and produced a prototypic malaria vaccine based on a highly versatile self-assembling polypeptide nanoparticle (SAPN) platform that can repetitively display antigenic epitopes. We used this platform to display a tandem repeat of the B cell immunodominant repeat epitope (DPPPPNPN)2D of the malaria parasite Plasmodium berghei circumsporozoite protein. Administered in saline, without the need for a heterologous adjuvant, the SAPN construct P4c-Mal conferred a long-lived, protective immune response to mice with a broad range of genetically distinct immune backgrounds including the H-2b, H-2d, and H-2k alleles. Immunized mice produced a CD4+ T cell-dependent, high-titer, long-lasting, high-avidity Ab response against the B cell epitope. Mice were protected against an initial challenge of parasites up to 6 mo after the last immunization or for up to 15 mo against a second challenge after an initial challenge of parasites had successfully been cleared. Furthermore, we demonstrate that the SAPN platform not only functions to deliver an ordered repetitive array of B cell peptide epitopes but operates as a classical immunological carrier to provide cognate help to the P4c-Mal-specific B cells.
T Cell Intrinsic Heterodimeric Complexes between HVEM and BTLA Determine Receptivity to the Surrounding Microenvironment
Authors: Cheung Timothy C. , Oborne Lisa M. , Steinberg Marcos W. , Macauley Matthew G. , Fukuyama Satoshi , Sanjo Hideki , D'Souza Claire , Norris Paula S. , Pfeffer Klaus , Murphy Kenneth M. , Kronenberg Mitchell , Spear Patricia G. , Ware Carl F.
Published: November 2009

The inhibitory cosignaling pathway formed between the TNF receptor herpesvirus entry mediator (HVEM, TNFRSF14) and the Ig superfamily members, B and T lymphocyte attenuator (BTLA) and CD160, limits the activation of T cells. However, BTLA and CD160 can also serve as activating ligands for HVEM when presented in trans by adjacent cells, thus forming a bidirectional signaling pathway. BTLA and CD160 can directly activate the HVEM-dependent NF-κB RelA transcriptional complex raising the question of how NF-κB activation is repressed in naive T cells. In this study, we show BTLA interacts with HVEM in cis, forming a heterodimeric complex in naive T cells that inhibits HVEM-dependent NF-κB activation. The cis-interaction between HVEM and BTLA is the predominant form expressed on the surface of naive human and mouse T cells. The BTLA ectodomain acts as a competitive inhibitor blocking BTLA and CD160 from binding in trans to HVEM and initiating NF-κB activation. The TNF-related ligand, LIGHT (homologous to lymphotoxins, exhibits inducible expression, and competes with HSV glycoprotein D for HVEM, a receptor expressed by T lymphocytes, or TNFSF14) binds HVEM in the cis-complex, but NF-κB activation was attenuated, suggesting BTLA prevents oligomerization of HVEM in the cis-complex. Genetic deletion of BTLA or pharmacologic disruption of the HVEM-BTLA cis-complex in T cells promoted HVEM activation in trans. Interestingly, herpes simplex virus envelope glycoprotein D formed a cis-complex with HVEM, yet surprisingly, promoted the activation NF-κB RelA. We suggest that the HVEM-BTLA cis-complex competitively inhibits HVEM activation by ligands expressed in the surrounding microenvironment, thus helping maintain T cells in the naive state.