bluuebunny/crossref_metadata_2025 huggingface dataset:
Markov Renewal Function and Markov Renewal‐Type Equations
Authors: Ziya Serhan
Published: January 2011

This article defines Markov‐renewal functions, introduces Markov renewal‐type equations, and gives a brief overview of the main results.
M
arkov Regenerative Processes
Authors: Serin Yasemin
Published: January 2011

Markov regenerative processes are continuous‐time stochastic processes with more general conditions of regeneration than regenerative processes. The limiting behavior of some queues with general distributions can be obtained using Markov regenerative argument. In this article, after some basic definitions, some results related to the transient and limiting properties of the Markov regenerative processes are given. Some results are demonstrated with examples.
Limit Theorems for Markov Renewal Processes
Authors: Ziya Serhan
Published: January 2011

This chapter defines Markov renewal type equations, introduces the key Markov renewal theorem, which is used in solving Markov renewal‐type equations in the limit, and demonstrates how the theorem can be used over an example.
Mathematical Programming Approaches to the Traveling Salesman Problem
Authors: Letchford Adam N. , Lodi Andrea
Published: January 2011

TheTraveling Salesman Problemor TSP is a fundamental and well‐known problem in combinatorial optimization. At present, the most successful algorithms for solving large‐scale instances of the TSP to proven (near‐)optimality are based on integer programming. This entry introduces the main theoretical and algorithmic tools involved. Topics covered include: formulations of the TSP, polyhedral theory, separation routines, and exact TSP algorithms.
MDPBasic Components
Authors: Patrick Jonathan
Published: January 2011

This article outlines the basic components of any Markov decision process (MDP) model. The purpose is to outline the process of turning a generic sequential decision problem into a mathematical model that can be used to find an optimal policy. The five components of any MDP model are presented as well as the definition of decision rules and policies that are the output of an MDP. The potential goals or objectives in an MDP are discussed but the details of determining the optimal set of decisions are developed in other articles. This article is essential for understanding the optimization tools outlined in the rest of the articles on MDP in the encyclopedia.
Direct Search Methods
Authors: Lewis Robert Michael , Torczon Virginia
Published: January 2011

Direct search methods are a class of optimization techniques that do not make explicit use of derivatives. Instead, they workdirectlywith values of the objective function to drive the search for an optimal value. Direct search methods were first formally proposed in the late 1950s and early 1960s and have remained popular with users due to their simplicity and their practical success on a wide range of problems. In recent years, direct search methods have received renewed interest due to new mathematical analysis, their suitability for parallel and distributed computing, and their utility in addressing optimization problems that involve complex computer simulations.
Heuristics and Their Use in Military Modeling
Authors: Hill Raymond R. , Pohl Edward A.
Published: January 2011

The military establishment uses many types of models during the planning and execution of military operations. Optimization models have always been an important class of models. However, as military systems, the scenarios in which those military systems are employed, and the impact of operations involving those military systems become more complex, classic optimization techniques based on mathematical programming can become impractical. Advances in computing capabilities have helped advance the use of heuristics to quickly find reasonable solutions to complex optimization problems. This article provides an overview of the more popular and powerful modern heuristics, most of which have analogies to natural systems. We also provide a representative survey of how these heuristics have been applied to specific classes of military optimization applications.
Model‐Based Forecasting
Authors: Radziukyniene Ingrida , Boyko Nikita , Pardalos Panos
Published: January 2011

This article provides an introduction to prediction techniques based on the presence of an underlying model. Autoregressive moving average, state switching, and Bayesian models as well as their combinations and generalizations are considered.
MonteCarlo Simulation for Quantitative Health Risk Analysis
Authors: Cullen Alison
Published: January 2011

Managing risky opportunities, scenarios, and decisions are the most interesting and challenging aspects of human life. But meaningful characterization of risks is elusive because it relies on information that is incomplete, imperfect, and/or variable across time, space, and populations. And, consequently, informed decision making may be compromised. Probabilistic tools such as Monte Carlo simulation have evolved by which uncertainty and variability are characterized and carried through a process of generating probabilistic estimates of risk. The goal of this article is to introduce basic tools and techniques, and some of the more common extensions practiced in the field.
Multiclass Queueing Network Models
Authors: Hasenbein John J.
Published: January 2011

This article introduces the modeling framework for open multiclass queueing network models. These models are more general than classical Jackson networks, allowing multiple customers types at each station, and more complex routing schemes. Scheduling policies, traffic equations, and the queueing network equations are discussed in detail.
Neuroeconomics Insights for Decision Analysis
Authors: Hytönen Kaisa , Sanfey Alan G.
Published: January 2011

Neuroeconomics is a developing field that utilizes methodologies from neuroscience, psychology and economics to study the brain networks that are activated during decision making. In this chapter, we outline the primary methods used by neuroeconomics and examine how this field can help build better models of decision‐making. First, we review research related to valuation processes and biases that occur in the brain, and discuss the properties of the human reward circuitry which reacts to both the anticipation and receipt of financial and hedonic rewards. Next, we discuss the balance between emotional and cognitive control areas in the brain, which have a central role in behavioral framing effects. We conclude with a discussion of how a better understanding of the brain processes can increase our knowledge of why decision‐making in the real world often strays quite far from the predictions made by standard utility maximization accounts.
The Operational Research Society
Authors: Sharp Graham
Published: January 2011

Formed as The OR Club in 1947, The Operational Research Society (The OR Society) was the world's first professional body to cater to the OR profession. The OR Society continues to be an innovator and leader by offering members a range of publications and journals as well as a comprehensive training programme, special interest groups and regional societies. The Society organises the largest national OR conference outside the US in addition to a YoungOR conference for people with up to ten years experience in OR.
Operations Research Applications in Truckload Freight Transportation Networks
Authors: Gifford Ted L.
Published: January 2011

This article describes a set of decision support systems based on operations research (OR) methodologies that arise in the planning, management, and operations of a large truckload transportation company. These tools support policy development activities and business processes that range across the time horizon from longer term planning cycles to real‐time driver dispatching and load management decisions. This discussion will highlight problems and solution models that appear to be either unique to truckload freight transportation or of particular interest in this area.
Operations Research Society of
C
hina*Part of the historical review of ORSC is from an article by Xiang‐Sun Zhang and Kan Cheng, “China: Ancient Country Makes OR History,” OR/MS Today, October 1998.
Authors: Yuan Ya‐Xiang , Zhang Xiang‐Sun , Liu Degang
Published: January 2011

This article gives a glimpse of OR in China, from the early years of OR in the ancient country upto the latest achievement in research and applications in various OR fields. Today an important discipline, OR education, research, and applications are developed fast since the founding of ORSC. The Chinese OR community is becoming ever more active in terms of teaching, academic research, industrial projects, and international exchanges. OR/MS‐related applications in decision support are becoming increasingly visible in China.

Instead of a comprehensive description, we aim to provide a portrait of OR history in China and the current OR Society of China: an active, growing, open, and collaborative community in the IFORS family.
Optimal Replacement and Inspection Policies
Authors: Kallen Maarten‐Jan
Published: January 2011

This article covers the selection of policies for the timing of inspections or replacements, which are optimal according to some predefined criterion. The primary application of such policies is in problems of maintenance optimization. The article provides an overview of some typical model assumptions and cost‐based criteria for policy evaluation. One such assumption is that repairs are equivalent to replacements in that they bring an item back to an as‐good‐as‐new condition. The mathematics of the inspection and replacement policies are therefore based on the results of renewal theory. Two common maintenance policies, namely age‐based and condition‐based replacements, are discussed in greater detail. Special attention is given to how the model parameters, which include the costs of inspections and preventive or corrective repairs, determine the optimal inspection or replacement interval.
Optimal Risk Mitigation and Risk‐Taking
Authors: Chapman Chris , Harwood Ian
Published: January 2011

Optimal risk mitigation and risk‐taking requires optimal framing and working assumptions using an overall optimality concept. Working assumptions should be specific to the context addressed, but framing assumptions and basic tools should be common for all application areas. The role of all three should be keeping any formal analysis as simple as possible, but introducing complexity which pays whenever it pays. This article uses case study examples to illustrate key issues.
Psychology of Risk Perception
Authors: Kortenkamp Katherine V. , Moore Colleen F.
Published: January 2011

Risk perceptions refer to subjective judgments of risk and are often found to deviate from numerical risk estimates. Although the probability and severity of risks do influence risk perceptions, risk perceptions are also influenced by many psychological factors. According to the psychometric model of risk, risk perceptions are characterized by two main dimensions: the degree to which a risk is dreaded and unknown. Dread risks are uncontrollable, catastrophic, involuntary, inequitable, fatal, new, global, and not easily reduced. Unknown risks are not understood by science, unobservable, new, and delayed in their effects. The psychometric model provides a framework for thinking about individual differences in risk perceptions, such as differences by gender, race, and level of expertise. Differences in risk perception can also be influenced by the degree to which people trust various sources of risk information, including the government, industry, and scientists. Finally, factors like uncertainty, fairness of risk distribution in society, and emotional reactions to risks also contribute to risk perceptions. Many of the psychological factors that influence risk perceptions cannot be easily quantified in numerical risk assessments; therefore, risk perceptions can be regarded as providing information that supplements numerical risk assessments in policy decisions.
R&DRisk Management
Authors: Felli James C. , Andersen John S.
Published: January 2011

Risk is a major concern in functional R&D organizations, and can arise from any number of sources from simple misunderstandings to natural disasters. Yet despite its importance and prevalence, risk is typically loosely described and poorly characterized. What exactly do we mean by the word “risk”? What distinguishes big risks from small ones? In this work, we discuss the notion and the depiction of risk from the perspective of an R&D organization. We first focus on the two fundamental determinants of risk: uncertainty and unwantedness. We provide a means for decomposing risk into context‐relevant categories to improve understanding and communication among R&D stakeholders. We then offer a graphical approach to visualize project risk over time before closing with a general discussion of portfolio level risk.
Revenue Management in the Travel Industry
Authors: Lieberman Warren
Published: January 2011

During the past half‐century, and especially during the past 30 years, the science of price optimization has advanced considerably. Beginning with the airlines, expanding to other segments of the travel industry and then beyond, many firms that invested in improving their pricing capabilities have reaped extraordinarily large rewards. This article provides a historical overview of why and how this transformation occurred within the travel industry.

Often misunderstood, this science known initially as yield management and then as revenue management has transformed the ways in which products are sold as well as how prices are set. Focusing initially on how many products to sell, given a set of prices that could be offered, the discipline now also includes finding the profit‐maximizing price levels.

From a relatively obscure business practice 50 years ago, yield (or revenue) management has emerged as one of the most significant technologies to transform the profitability of travel companies. And had it not been for dramatic changes in the way airlines competed for business, it might never have happened. Here is that story.
Tour Scheduling and Rostering
Authors: Robbins Tom
Published: January 2011

In this article, we examine the problem of scheduling a service operation; that is, defining the set of shifts for workers that best meets the demand profile, and of assigning individual workers to those shifts. Tour scheduling identifies the number of agents assigned to specific start and end times over the course of the planning period. Rostering is the process of assigning individual agents to specific shift schedules. In this article, we develop a basic example based on a call center application. We discuss how the problem can be formulated and solved as an integer program. We then discuss how the problem can grow unwieldy as staffing flexibility increases and discuss approaches for dealing with that problem. Finally, we identify issues that arise in other, noncall center applications.
S
lovenian Society Informatika (
SSI
)–Section for Operations Research (
SOR
)
Authors: Stirn Lidija Zadnik
Published: January 2011

The article presents general information on the Slovenian Society INFORMATIKA (SSI)—Section for Operations Research (SOR). Some facts about the constitution of SOR in 1992 are explained and the leading persons of the SOR Constitution Committee are introduced. The mission of SOR, the number of members, and the structure of SOR are presented. The main activities of SOR, especially those at international level, are described. Further, the most important and internationally recognized publications of SOR are listed, among all proceedings and monographs. In continuation, SSI, under whose umbrella SOR is taking an active role, is portrayed. The activities of SSI as well as its publications are explained.
Stochastic Modeling and Optimization in Baseball
Authors: Null Brad
Published: January 2011

This article reviews operations research techniques that can be and are used to address common decision making problems in baseball, focusing on those geared toward improving a team's probability of winning games and championships. We organize these problems into three groups: (i) on‐field decisions–determining what a batter, pitcher, runner, or fielder will do at any point in the game; (ii) player usage decisions–determining which players to use at which points in the game; and (iii) personnel decisions–determining who should be on the team and how much they are worth. We also outline several stochastic modeling approaches to assess the underlying elements of uncertainty with respect to these problems.
The Graph Model For Conflict Resolution
Authors: Hipel Keith W. , Kilgour D. Marc , Fang Liping
Published: January 2011

The Graph Model for Conflict Resolution is a flexible methodology for realistically and conveniently studying actual social disputes. An international controversy over the sharing of water in the Aral Sea Basin of Central Asia is employed to illustrate how a conflict can be formally modeled and analyzed using a decision support system that implements the Graph Model methodology as a flexible computerized system in order to obtain strategic insights for enhancing the decision making process. Recent developments that are described for expanding the Graph Model methodology include techniques for handling uncertain preferences and psychological factors such as attitudes, emotions, and misunderstandings.
Value Functions Incorporating Disappointment and Regret
Authors: Moretti Laura , Cristofori Irene , Sirigu Angela
Published: January 2011

How humans make decisions is attracting more and more interest of neuroscientists. The understanding of neural mechanisms underlying the way people choose, attach value to things, set preferences, enjoy reward, or fear punishement is now possible using an array of methods. Game theory, a highly influential view in economics, can predict choices made in various situations involving strategic thinking or competitive interactions among individuals. Its assumption is that under most circumstances people will act as rational decision makers. Recent neuroscientific findings, however, have shown that emotions such as regret, interact with utility‐maximization in ways that challenge the theory. Interestingly, the intensity of regret has been found to be a better predictor of subsequent choices than expected utility alone. Specific brain regions such as the orbitofrontal cortex and the amygdala seem crucial for experiencing the complex emotion of regret.
Robustness Analysis
Authors: Rosenhead Jonathan
Published: January 2011

Robustness Analysis is a method for evaluating initial decision commitments under conditions of uncertainty, where subsequent decisions will be implemented over time. The robustness of an initial decision is an operational measure of the flexibility which that commitment will leave for useful future decision choice.
Resource Modeling Association
Authors: McKelvey Steven
Published: January 2011

The Resource Modeling Association (RMA) is an international, interdisciplinary scholarly organization dedicated to the design, promulgation, and use of mathematical models for the study and management of natural resources. Founded in the early 1980s, the association's aims are supported by the quarterly publication of a peer‐reviewed academic journal, Natural Resources Modeling, and the sponsorship of an annual scholarly meeting, the World Conference on Natural Resource Modeling, held at locations throughout the world.
The Nascent Industry of Electric Vehicles
Authors: Klabjan Diego , Sweda Timothy
Published: January 2011

An electric vehicle (EV) is a vehicle that operates solely using electricity and can plug into the power grid to recharge. This connectivity with the grid poses a unique set of challenges, as the new EV charging infrastructure must be compatible with the existing power infrastructure and the grid must be able to support the growing fleet of EVs. Of particular interest to operations researchers are an assortment of pricing and planning problems, many of which are still ill‐defined due to the youth of today's EV industry and the uncertainties that accompany it. In this article, the needs of the growing EV industry are addressed, and some of the key issues that will be faced over the next several years are identified.
Operations Research Approaches to Asset Management in Freight Rail
Authors: Gorman Michael F. , Harrod Steven
Published: January 2011

This article describes operations research methodologies as they apply to asset management in freight rail. We describe state‐of‐the‐art methods for locomotive, crew, railcar, line and yard planning and management. We conclude with emerging areas of research in rail.
Operations Research for Freight Train Routing and Scheduling
Authors: Harrod Steven , Gorman Michael F.
Published: January 2011

This article describes the service design activities that plan and implement the rail freight operating plan. Elements of strategic service design include the setting of train frequency, the routing of cars among trains, and the consolidation of cars, called
blocking
. At the operational level, trains are dispatched either according to train paths configured in advance, called
timetables
, or according to priority rules. We describe the North American and European practice along with selected modeling and problem solving methodologies appropriate for each of the operating conditions described.
Rule Developing Experimentation in Consumer‐Driven Package Design
Authors: Gofman Alex
Published: January 2011

The article describes an approach to consumer‐driven optimization of package design, particularly based on conjoint analysis. It allows for dynamic creation and testing of a large number of conceptual design prototypes with consumers and finding optimal solutions on an aggregated, segmented (pattern‐based latent mind‐set segmentation), and individual basis. The approach extends the consumer insights‐driven process, Rule Developing Experimentation (RDE), developed under the guidance of the Wharton School of Business (University of Pennsylvania), to graphical concepts.

The empirical study findings suggests that marketers should be more specific with the fat content shown on the package. The yogurt package message with numerical value of the fat content (“50% less fat”) consistently is more efficient in driving purchase intent than its verbal equivalent (“half the fat”) or a more abstract “light with less fat” across all the subgroups.

The approach could help marketers efficiently create better packages that consumers like, and facilitate differentiation of their products from the competition. The article demonstrates that consumer research could and should be a central part not only at the final stages of the package design but at the initial stage as well. The steps of fitting the research into the package design process that include consumers in the early stages of package design are shown.
Decision Analysis and Counterterrorism
Authors: Lloyd Jamie D. , Merrick Jason R. W.
Published: January 2011

Significant research has been performed on counterterrorism decisions in recent years. As with all applications involving significant potential risks and large investments, the efficacy of decision analysis has been tested and new ways of performing analyses found. In this article, we discuss several important studies and the approaches researchers have used to prescribe appropriate alternatives for counterterrorism.
Public Health, Emergency Response, and Medical PreparednessII: Medical Countermeasures Dispensing and Large‐Scale Disaster Relief Efforts
Authors: Lee Eva K. , Pietz Ferdinand , Benecke Bernard
Published: January 2011

A catastrophic health event, such as a terrorist attack with a biological agent, a naturally occurring pandemic, or a calamitous meteorological or geological event, could cause tens or hundreds of thousands of casualties, weaken the economy, damage public morale and confidence, create panic and civil unrest, and threaten national security. It is therefore critical to establish a strategic vision that will enable a level of public health and medical preparedness sufficient to address a range of possible disasters. Planning for a catastrophe involving a disease outbreak or mass casualties is an ongoing challenge for first responders and emergency managers. They must make critical decisions on treatment distribution points, staffing levels, impacted populations, and potential impact in a compressed window of time when seconds could mean life or death. Some of the key areas of public health and medical preparedness include medical surge, population protection, communication infrastructure, and emergency evacuation. This article highlights our own experience on projects with the Centers for Disease Control and Prevention and various public health jurisdictions in emergency response and medical preparedness for mass dispensing for disease prevention and treatment, and large‐scale disaster relief efforts.
Public Health, Emergency Response, and Medical PreparednessIV: Emergency Evacuation
Authors: Lee Eva K. , Yang Anna Yang , Pietz Ferdinand , Benecke Bernard
Published: January 2011

In the aftermath of the September 11 terrorist attacks and the dissemination of anthrax in 2001, the ability of the US health‐care system to provide an effective and coordinated response and evacuation capability to mitigate mass casualty or complex incidents came under intense scrutiny. More recently, the devastation caused by Hurricane Katrina and the mass disruption of public health and medical services along the Gulf Coast spotlighted the need for cohesive strategies that focus on mounting effective evacuation and response for catastrophic events. Determining the most effective evacuation plan for a large public facility requires in‐depth analysis of multiple interdependent and competing factors. Determining the best routes, foreseeing potential problems, addressing the chaos/panic factor, and orchestrating the evacuation are all critical aspects that should be evaluated in a well‐developed disaster management plan. The success of the evacuation of 80,000 in the stadium Santiago Bernabeu in Madrid, Spain within 7 min sheds some light on the potential to save many lives through careful planning and proper evacuation responses. Emergency responders and coordinators must be equipped with such knowledge so as to protect the regional population during critical incidents. In this article, we seek to understand the elements that influence evacuation planning, issues faced by decision makers, as well as methodologies from the field of operations research that are leading to more effective planning and execution.
5‐Carboxymethyl‐2‐(4‐methylthiophenyl)‐1,3,2‐dioxaborolan‐4‐one: synthesis, characterization and application in enantioselective reduction of ketones
Authors: Górska Agnieszka , Hajmowicz Halina , Kliś Tomasz , Serwatowski Janusz , Synoradzki Ludwik
Published: January 2011

The reaction of arylboronic acids with L‐O‐benzoyl‐tartaric acid and D,L‐malic acid has been studied. The obtained (acyloxy)boranes are moderately stable in solution and decompose to give boroxines. 5‐Carboxymethyl‐2‐(4‐methylthiophenyl)‐1,3,2‐dioxaborolan‐4‐one was obtained in the reaction of 4‐methylthiophenylboronic acid with D,L‐malic acid and characterized by X‐ray structural analysis. The use of L‐(−)‐malic acid afforded the optically pure product which can be used as the powerful chiral reagent in the enantioselective reduction of ketones. Copyright © 2011 John Wiley & Sons, Ltd.
Testing a depth‐based Habitat Classification System against reef fish assemblage patterns in a subtropical marine park
Authors: Malcolm Hamish A. , Jordan Alan , Smith Stephen D. A.
Published: January 2011

The Solitary Islands Marine Park (SIMP) in New South Wales (NSW), Australia, has strong cross‐shelf patterns of reef fish assemblages on shallow reefs (<25 m). While the SIMP also contains reef at depths of up to 75 m, marine communities below 25 m are poorly described. The Habitat Classification System (HCS) used for planning the arrangement of zones in this marine park included three depth categories for reef: shallow (<25 m); intermediate (25–60 m); and deep (>60 m). However, these had not been tested to determine if they adequately reflect biotic patterns.

Using baited remote underwater video (BRUV), fish assemblages were surveyed at 56 sites spread across shallow, intermediate, and deep reefs within the SIMP to examine spatial variation between depth categories. Relationships between assemblage patterns, depth, and four additional factors considered likely to affect assemblage patterns (distance from shore, reef type, dominant benthos, and latitude), were subsequently explored using multivariate statistical methods.

Reef fish assemblages differed significantly among the depth categories. Assemblage patterns for fish were strongly correlated with depth and moderately correlated with the dominant benthic assemblage. Correlations with the other factors were generally weak. Three distinct assemblages occurred on reefs <25 m, 25–50 m and >50 m. Shallow (<25 m) reefs also displayed strong cross‐shelf patterns, supporting the results from other studies. Weaker cross‐shelf patterns were evident at intermediate depths (25–50 m).

Depth‐based and cross‐shelf categories are clearly fundamental components for a HCS that will adequately represent reef fish assemblages for conservation planning in the SIMP. Further refining the depth criteria for the intermediate/deep boundary (to 50 m) improves this representation. Further research is required to determine the wider application of the refined HCS to other marine parks in NSW and to determine how well it represents other components of biodiversity. Copyright © 2011 John Wiley & Sons, Ltd.
1α,25‐Dihydroxyvitamin D3 on intestinal transporter function: studies with the rat everted intestinal sac
Authors: Maeng Han‐Joo , Durk Matthew R. , Chow Edwin C. Y. , Ghoneim Ragia , Pang K. Sandy
Published: January 2011

Previous studies have shown that 1α,25‐dihydroxyvitamin D3 (1,25(OH)2D3) treatment (2.56 nmol/kg i.p. daily×4) increased PepT1, Mrp2, Mrp4, Asbt, but not Mdr1/P‐gp in the rat small intestine. In this study, the intestinal everted sac technique, together with various select probes: mannitol (paracellular transport), glycylsarcosine (PepT1), 5(and 6)‐carboxy‐2′,7′‐dichlorofluorescein (CDF) diacetate (precursor of CDF for Mrp2), adefovir dipivoxil (precursor of adefovir for Mrp4) and digoxin (P‐gp) was used to examine the functional changes of these transporters. After establishing identical permeabilities (Papp) of mannitol for the apical‐to‐basolateral (A‐to‐B) and basolateral‐to‐apical (B‐to‐A) directions at 20 min in 1,25(OH)2D3‐treated vs. vehicle‐treated duodenal, jejunal and ileal everted sacs, a significant enhancement of net A‐to‐B transport of glycylsarcosine in the duodenum, increased B‐to‐A transport of CDF and A‐to‐B and B‐to‐A transport of adefovir in the jejunum were observed with 1,25(OH)2D3 treatment. However, the A‐to‐B and B‐to‐A transport of digoxin in the ileum was unchanged. These changes in transporter function in the rat intestinal everted sac corresponded well to changes in proteins that were observed previously. This study confirms that the rat intestinal PepT1, Mrp2 and Mrp4, but not P‐gp are functionally induced by 1,25(OH)2D3 treatment via the vitamin D receptor (VDR). Copyright © 2011 John Wiley & Sons, Ltd.
Cleavage of Functionalized DNA Containing 5‐Modified Pyrimidines by Type II Restriction Endonucleases
Authors: Macíčková‐Cahová Hana , Pohl Radek , Hocek Michal
Published: January 2011

A series of six pyrimidine‐modified dNTPs—5‐ethynyl‐, 5‐phenyl‐, and 5‐(3‐nitrophenyl)deoxycitidine and ‐deoxyuridine triphosphates—were prepared and incorporated by primer extension with Vent (exo‐)polymerase to specific DNA sequences within or next to the recognition sequences of selected restriction endonucleases. The cleavage of these pyrimidine‐modified DNA sequences by 13 restriction enzymes was then studied. Whereas the presence of any modified C within the target sequence completely prevented any restriction cleavage, most enzymes tolerated the presence of 5‐ethynylU and two of them even the presence of 5‐phenyl‐ and 5‐(3‐nitrophenyl)U. Modifications outside the recognition sequence were tolerated except in the case of phenyl derivatives with the PvuII enzyme. 5‐EthynylC was used for protection of the recognition sequence from cleavage in the presence of the second unmodified copy of the same sequence that was cleaved.
An In Situ Dealloying and Oxidation Route to Co3O4 Nanosheets and their Ambient‐Temperature CO Oxidation Activity
Authors: Xu Caixia , Liu Yunqing , Zhou Ce , Wang Lin , Geng Haoran , Ding Yi
Published: January 2011

Co3O4 nanosheets are straightforwardly fabricated through an in situ dealloying and oxidation process of etching CoAl alloy in alkaline solutions. X‐ray diffraction and electron spectroscopy characterizations demonstrate the formation of a Co3O4 nanostructure with an intricate hierarchical nanosheet morphology comprising interconnected nanoslices with the diameter as small as 6 nm. Upon calcination in O2 atmosphere, these novel Co3O4 nanosheets exhibit excellent catalytic activity toward CO oxidation in normal feed gas at ambient temperature. Catalytic tests reveal the strong influence of calcination temperature on the resultant catalytic activities, whereby 300 °C is found to be preferable possibly due to an optimum balance between the surface area and the amount of active species as compared with 200 and 450 °C. Moreover, Co3O4 nanosheets showed good time‐on‐stream catalytic stability; CO conversion at T50 (the temperature for 50 % CO conversion) reduced to 37 % after 20 h, and at T100 (the temperature for full CO conversion) the conversion only decreased to about 90 % after 15 h.
Chiral Metal‐Organic Frameworks and Their Application in Asymmetric Catalysis and Stereoselective Separation
Authors: Nickerl Georg , Henschel Antje , Grünker Ronny , Gedrich Kristina , Kaskel Stefan
Published: January 2011

The targeted synthesis of a desired stereomer plays a key role in life sciences, especially in the production of drugs. Up to date, this area is dominated by homogeneous chiral catalysts. Metal‐Organic Frameworks (MOFs), a new class of porous materials, consisting of metal‐oxo‐clusters and multifunctional ligands could offer a platform for chiral heterogeneous catalysts combining the efficiency and in particular selectivity observed for homogeneous asymmetric catalysts with the advantages of heterogeneous catalysis. This review summarizes strategies to obtain chiral Metal‐Organic Frameworks and gives an overview about reactions that have been successfully conducted using chiral MOFs as asymmetric catalysts. In addition, some examples highlighting the stereoselective adsorption properties of chiral Metal‐Organic Frameworks are given.
The Impact of Mesopores on Mass Transfer in Nanoporous Materials: Evidence of Diffusion Measurement by NMR
Authors: Valiullin Rustem , Kärger Jörg
Published: January 2011

The purposeful incorporation of mesopores has become an important issue of the synthesis and post‐synthesis modification of nanoporous solids for generating transport‐optimized materials. The potentials of the pulsed field gradient (PFG) technique of NMR for assessing the transport properties of such materials are discusses and first case studies demonstrating the spectrum of information provided by the application of this technique to diffusion studies in hierarchical porous materials and the still existing limitations are presented.
Constructing u‐City of Seoul by future foresight analysis
Authors: Woo Jung‐Hun , Kim HyungSeok , Lim Sang Boem , Kim Jae‐Jin , Lee Jonghyun , Ryoo Rina , Kim Hansoo , Minh Le Dinh
Published: January 2011

AirScope is a micro‐scale modeling system as well as a micro‐scale air quality monitoring system, which comprises as a micro‐scale air quality management system. Importance of micro‐scale air monitoring is rising due to the concern about environment near residential places. Traditional monitoring methods are providing overall air quality indexes. However, these methods have limited functionalities to provide air quality of near my house or where I am now. In this paper, we are trying to overcome the limitation of traditional methods by using ubiquitous sensor network (USN). AirScope consists of computational fluid dynamics based air quality modeling, USN‐based sensor monitoring, and multi‐modal interaction platform. We present a brief overview of AirScope and several aspects of constructed initial indoor test environment with a few validity tests. The proposed system will be extended to an outdoor real‐world testbed with most of modern urban elements. Copyright © 2011 John Wiley & Sons, Ltd.
A distributed evolutionary approach for multisite mapping on grids
Authors: De Falco I. , Scafuri U. , Tarantino E.
Published: January 2011

In this paper attention is concentrated on the mapping of computationally intensive multi‐task applications onto shared computational grids. This problem, already known to be as NP‐complete in parallel systems, becomes even more arduous in such environments. To find a near‐optimal mapping solution a parallel version of a Differential Evolution algorithm is presented and evaluated on different applications and operating conditions of the grid nodes. The purpose is to select for a given application the mapping solutions that minimize the greatest among the time intervals which each node dedicates to the execution of the tasks assigned to it. The experiments, effected with applications represented as task interaction graphs, demonstrate the ability of the evolutionary tool to perform multisite grid mapping, and show that the parallel approach is more effective than the sequential version both in enhancing the quality of the solution and in the time needed to get it. Copyright © 2011 John Wiley & Sons, Ltd.
Rotationally Resolved Electronic Spectroscopy of 1,4‐Benzodioxan: The Anomeric Effect in the Ground and Electronically Excited State
Authors: Chau Vu Thi Bao , Brand Christian , Meerts W. Leo , Schmitt Michael
Published: January 2011

We measured the rotationally resolved electronic spectra of the origin and of three vibronic bands of 1,4‐benzodioxan. From comparison to various ab‐initio‐calculated structures of 1,4‐benzodioxan, the twisted C2 symmetric 1,4‐benzodioxan was shown to be responsible for all the observed spectral features. We analyzed the inertial defects in both electronic states as sensitive indicators of the non‐planarity of the system. The molecule was found to be more planar in the electronic ground state than in the electronically excited singlet state. This effect can be traced back to an increased puckering of the dioxan ring, which also comprises the oxygen atoms, in the excited state. This observation is discussed in terms of natural bond orbitals.
Right Ventricle in Pulmonary Hypertension
Authors: Voelkel Norbert F. , Natarajan Ramesh , Drake Jennifer I. , Bogaard Herman J.
Published: January 2011

During heart development chamber specification is controlled and directed by a number of genes and a fetal heart gene expression pattern is revisited during heart failure

. In the setting of chronic pulmonary hypertension the right ventricle undergoes hypertrophy, which is likely initially adaptive, but often followed by decompensation, dilatation and failure. Here we discuss differences between the right ventricle and the left ventricle of the heart and begin to describe the cellular and molecular changes which characterize right heart failure. A prevention and treatment of right ventricle failure becomes a treatment goal for patients with severe pulmonary hypertension it follows that we need to understand the pathobiology of right heart hypertrophy and the transition to right heart failure. © 2011 American Physiological Society.
Compr Physiol
1:525‐540, 2011.
Hibernation and Gas Exchange
Authors: Milsom William K. , Jackson Donald C.
Published: January 2011

Hibernation in endotherms and ectotherms is characterized by an energy‐conserving metabolic depression due to low body temperatures and poorly understood temperature‐independent mechanisms. Rates of gas exchange are correspondly reduced. In hibernating mammals, ventilation falls even more than metabolic rate leading to a relative respiratory acidosis that may contribute to metabolic depression. Breathing in some mammals becomes episodic and in some small mammals significant apneic gas exchange may occur by passive diffusion via airways or skin. In ectothermic vertebrates, extrapulmonary gas exchange predominates and in reptiles and amphibians hibernating underwater accounts for all gas exchange. In aerated water diffusive exchange permits amphibians and many species of turtles to remain fully aerobic, but hypoxic conditions can challenge many of these animals. Oxygen uptake into blood in both endotherms and ectotherms is enhanced by increased affinity of hemoglobin for O2at low temperature. Regulation of gas exchange in hibernating mammals is predominately linked to CO2/pH, and in episodic breathers, control is principally directed at the duration of the apneic period. Control in submerged hibernating ectotherms is poorly understood, although skin‐diffusing capacity may increase under hypoxic conditions. In aerated water blood pH of frogs and turtles either adheres to alphastat regulation (pH ∼8.0) or may even exhibit respiratory alkalosis. Arousal in hibernating mammals leads to restoration of euthermic temperature, metabolic rate, and gas exchange and occurs periodically even as ambient temperatures remain low, whereas body temperature, metabolic rate, and gas exchange of hibernating ectotherms are tightly linked to ambient temperature. © 2011 American Physiological Society.Compr Physiol1:397‐420, 2011.
A sliding window‐based false‐negative approach for ubiquitous data stream analysis
Authors: Kim Younghee , Park Doo‐soon , Kim Heewan , Kim Ungmo
Published: January 2011

Ubiquitous data stream mining (UDSM) is the process of performing data analysis on mobile, embedded and ubiquitous devices. In many cases, a large volume of data can be mined for interesting and relevant information in a wide variety of applications. Data stream mining requires computationally intensive mining techniques to be applied in mobile environments constrained by analysis of a real‐time single pass with limited computational resources. Therefore, we have to ensure that the result is within the error tolerance range. In this paper, we suggest a method for a false‐negative approach based on the Chernoff bound for efficient analysis of the data stream. Hence, we consider the problem of approximating frequency counts for space‐efficient computation over data stream sliding windows. We show that a false‐negative approach allowing a controlled number of frequent itemsets to be missing from the output is a more promising solution for mining frequent itemsets from a ubiquitous data stream. These are simple to implement, and have provable quality, space, and time guarantees. The experimental results have shown that the proposed algorithms achieve a high accuracy of at least 99% and require a small execution time. Copyright © 2011 John Wiley & Sons, Ltd.
IL‐9 is a Th17‐derived cytokine that limits pathogenic activity in organ‐specific autoimmune disease
Authors: Stephens Geoffrey L. , Swerdlow Bonnie , Benjamin Ebony , Coyle Anthony J. , Humbles Alison , Kolbeck Roland , Fung Michael
Published: January 2011

IL‐9 is a pleiotropic cytokine with key functions in tolerance and inflammation, and its expression is considered a hallmark of Th2‐lineage cells. Here, we report that human and mouse Th17 cells are a significant source of IL‐9. The expression of IL‐9 by Th17 cells was strictly dependent on the presence of TGF‐β and IL‐1β, and inhibited by IL‐4. IL‐9‐deficient Th17 cells induced more severe autoimmune gastritis following transfer to nu/nu recipient mice. Th17 cells did not appear to be the target of IL‐9 bioactivity as Th17 expansion and differentiation was comparable using IL‐9‐deficient CD4+ cells or when IL‐9 was neutralized with antibodies in vitro. However, reduced mast cell activity was associated with the increased pathogenicity of IL‐9‐deficient Th17 cells. Together, these results demonstrate a previously unappreciated role for IL‐9 in dampening the pathogenic activities of Th17 cells.
Functional type 1 regulatory T cells develop regardless of FOXP3 mutations in patients with IPEX syndrome
Authors: Passerini Laura , Di Nunzio Sara , Gregori Silvia , Gambineri Eleonora , Cecconi Massimiliano , Seidel Markus G. , Cazzola Giantonio , Perroni Lucia , Tommasini Alberto , Vignola Silvia , Guidi Luisa , Roncarolo Maria G. , Bacchetta Rosa
Published: January 2011

Mutations of forkhead box p3 (FOXP3), the master gene for naturally occurring regulatory T cells (nTregs), are responsible for the impaired function of nTregs, resulting in an autoimmune disease known as the immune dysregulation, polyendocrinopathy, enteropathy, X‐linked (IPEX) syndrome. The relevance of other peripheral tolerance mechanisms, such as the presence and function of type 1 regulatory T (Tr1) cells, the major adaptive IL‐10‐producing Treg subset, in patients with IPEX syndrome remains to be clarified. FOXP3mutated Tr1‐polarized cells, differentiated in vitro from CD4+ T cells of four IPEX patients, were enriched in IL‐10+IL‐4−IFN‐γ+ T cells, a cytokine production profile specific for Tr1 cells, and expressed low levels of FOXP3 and high levels of Granzyme‐B. IPEX Tr1 cells were hypoproliferative and suppressive, thus indicating that FOXP3 mutations did not impair their function. Furthermore, we isolated Tr1 cell clones from the peripheral blood of one FOXP3null patient, demonstrating that Tr1 cells are present in vivo and they can be expanded in vitro in the absence of WT FOXP3. Overall, our results (i) show that functional Tr1 cells differentiate independently of FOXP3, (ii) confirm that human Tr1 and nTregs are distinct T‐cell lineages, and (iii) suggest that under favorable conditions Tr1 cells could exert regulatory functions in IPEX patients.
PA28 and the proteasome immunosubunits play a central and independent role in the production of MHC class I‐binding peptides in vivo
Authors: de Graaf Natascha , van Helden Mary J. G. , Textoris‐Taube Kathrin , Chiba Tomoki , Topham David J. , Kloetzel Peter‐Michael , Zaiss Dietmar M. W. , Sijts Alice J. A. M.
Published: January 2011

Proteasomes play a fundamental role in the processing of intracellular antigens into peptides that bind to MHC class I molecules for the presentation of CD8+ T cells. Three IFN‐γ‐inducible catalytic proteasome (immuno)subunits as well as the IFN‐γ‐inducible proteasome activator PA28 dramatically accelerate the generation of a subset of MHC class I‐presented antigenic peptides. To determine whether these IFN‐γ‐inducible proteasome components play a compounded role in antigen processing, we generated mice lacking both PA28 and immunosubunits β5i/LMP7 and β2i/MECL‐1. Analyses of MHC class I cell‐surface levels ex vivo demonstrated that PA28 deficiency reduced the production of MHC class I‐binding peptides both in cells with and without immunosubunits, in the latter cells further decreasing an already diminished production of MHC ligands in the absence of immunoproteasomes. In contrast, the immunosubunits but not PA28 appeared to be of critical importance for the induction of CD8+ T‐cell responses to multiple dominant Influenza and Listeria‐derived epitopes. Taken together, our data demonstrate that PA28 and the proteasome immunosubunits use fundamentally different mechanisms to enhance the supply of MHC class I‐binding peptides; however, only the immunosubunit‐imposed effects on proteolytic epitope processing appear to have substantial influence on the specificity of pathogen‐specific CD8+ T‐cell responses.