bluuebunny/crossref_metadata_2025 huggingface dataset:
Measuring and evaluating efficiency and effectiveness using goal programming and data envelopment analysis in a fuzzy environment
Authors: Nimish Sheth , Triantis Konstantinos
Published: November 2006

Generally, in most situations optimal achievement of multiple goals is rarely possible for crisp mathematical programming techniques. In such cases, a compromise achievement of goals that leads to a satisfying solution rather than an optimal solution bears more relevance. The present research introduces a Fuzzy Goal Data Envelopment Analysis (Fuzzy GoDEA) framework to measure and evaluate the goals of efficiency and effectiveness in a fuzzy environment. Fuzzy GoDEA accommodates crisp input and output data but allows imprecise specification of the aspiration levels for the efficiency and effectiveness goals. A membership function is defined for each fuzzy constraint associated with the efficiency and effectiveness goals and represents the degree of achievement of that constraint. Further, the Fuzzy GoDEA framework is extended into several variations that (i) allow the assignment of relative importance to the goals of efficiency and effectiveness and (ii) model scenarios where one of the goals of efficiency and effectiveness is crisp and the other fuzzy. The Fuzzy GoDEA framework is implemented for a newspaper preprint insertion process (NPIP). .
Optimal taxation policy maximum-entropy approach
Authors: Jana P. , Mazumder S.K. , Das N.C.
Published: November 2006

The object of this paper is firstly to present entropic measure of income inequality and secondly to develop maximum entropy approaches for the optimal reduction of income inequality through taxation. .
A time-predefined approach to course timetabling
Authors: Burke Edmund , Bykov Yuri , Newall James , Petrovic Sanja
Published: November 2006

A common weakness of local search metaheuristics, such as Simulated Annealing, in solving combinatorial optimization problems, is the necessity of setting a certain number of parameters. This tends to generate a significant increase in the total amount of time required to solve the problem and often requires a high level of experience from the user. This paper is motivated by the goal of overcoming this drawback by employing "parameter-free" techniques in the context of automatically solving course timetabling problems. We employ local search techniques with "straightforward" parameters, i.e. ones that an inexperienced user can easily understand. In particular, we present an extended variant of the "Great Deluge" algorithm, which requires only two parameters (which can be interpreted as search time and an estimation of the required level of solution quality). These parameters affect the performance of the algorithm so that a longer search provides a better result - as long as we can intelligently stop the approach from converging too early. Hence, a user can choose a balance between processing time and the quality of the solution. The proposed method has been tested on a range of university course timetabling problems and the results were evaluated within an International Timetabling Competition. The effectiveness of the proposed technique has been confirmed by a high level of quality of results. These results represented the third overall average rating among 21 participants and the best solutions on 8 of the 23 test problems. .
On some aspects of the matrix data perturbation in linear program
Authors: Kon-Popovska Margita
Published: November 2006

Linear program under changes in the system matrix coefficients has proved to be more complex than changes of the coefficients in objective functions and right hand sides. The most of the previous studies deals with problems where only one coefficient, a row (column), or few rows (columns) are linear functions of a parameter. This work considers a more general case, where all the coefficients are polynomial (in the particular case linear) functions of the parameter tT??R. For such problems, assuming that some non-singularity conditions hold and an optimal base matrix is known for some particular value t of the parameter, corresponding explicit optimal basic solution in the neighborhood of t is determined by solving an augmented LP problem with real system matrix coefficients. Parametric LP can be utilized for example to model the production problem where, technology, resources, costs and similar categories vary with time. .
Neuro-fuzzy modeling in bankruptcy prediction
Authors: Vlachos D. , Tolias Y.A.
Published: November 2006

For the past 30 years the problem of bankruptcy prediction had been thoroughly studied. From the paper of Altman in 1968 to the recent papers in the '90s, the progress of prediction accuracy was not satisfactory. This paper investigates an alternative modeling of the system (firm), combining neural networks and fuzzy controllers, i.e. using neuro-fuzzy models. Classical modeling is based on mathematical models that describe the behavior of the firm under consideration. The main idea of fuzzy control, on the other hand, is to build a model of a human control expert who is capable of controlling the process without thinking in a mathematical model. This control expert specifies his control action in the form of linguistic rules. These control rules are translated into the framework of fuzzy set theory providing a calculus, which can stimulate the behavior of the control expert and enhance its performance. The accuracy of the model is studied using datasets from previous research papers.
Convergence of estimated optimal inventory levels in models with probabilistic demands
Authors: Bouza Carlos
Published: November 2006

The behavior of estimations of the optimal inventory level is analyzed. Two models are studied. The demands follow unknown probability distribution function. The included density functions are estimated and a plug-in rule is suggested for computing estimates of the optimal levels. Two search algorithms are proposed and compared using Monte Carlo experiments. .
An alternative approach for choice models in transportation: Use of possibility theory for comparison of utilities
Authors: Dell’orco Mauro , Kikuchi Shinya
Published: November 2006

Modeling of human choice mechanism has been a topic of intense discussion in the transportation community for many years. The framework of modeling has been rooted in probability theory in which the analyst?s uncertainty about the integrity of the model is expressed in probability. In most choice situations, the decision-maker (traveler) also experiences uncertainty because of the lack of complete information on the choices. In the traditional modeling framework, the uncertainty of the analyst and that of the decision-maker are both embedded in the same random term and not clearly separated. While the analyst's uncertainty may be represented by probability due to the statistical nature of events, that of the decision maker, however, is not always subjected to randomness; rather, it is the perceptive uncertainty. This paper proposes a modeling framework that attempts to account for the decision maker?s uncertainty by possibility theory and then the analyst's uncertainty by probability theory. The possibility to probability transformation is performed using the principle of uncertainty invariance. The proposed approach accounts for the quality of information on the changes in choice probability. The paper discusses the thought process, mathematics of possibility theory and probability transformation, and examples.
Three dimensional fixed charge bi-criterion indefinite quadratic transportation problem
Authors: Arora S.R. , Khurana Archana
Published: November 2006

The three-dimensional fixed charge transportation problem is an extension of the classical three-dimensional transportation problem in which a fixed cost is incurred for every origin. In the present paper three-dimensional fixed charge bi-criterion indefinite quadratic transportation problem, giving the same priority to cost as well as time, is studied. An algorithm to find the efficient cost-time trade off pairs in a three dimensional fixed charge bi-criterion indefinite quadratic transportation problem is developed. The algorithm is illustrated with the help of a numerical example.
Retailer’s replenishment policies under conditions of permissible delay in payments
Authors: Huang Yung-Fu
Published: November 2006

Goyal (1985) is frequently cited when the inventory systems under conditions of permissible delay in payments are discussed. Goyal implicitly assumed that: 1. The unit selling price and the unit purchasing price are equal; 2. At the end of the credit period, the account is settled. The retailer starts paying for higher interest charges on the items in stock and returns money of the remaining balance immediately when the items are sold. But these assumptions are debatable in real-life situations. The main purpose of this paper is to modify Goyal?s model to allow the unit selling price and the unit purchasing price not necessarily be equal to reflect the real-life situations. Furthermore, this paper will adopt different payment rule. We assume that the retailer uses sales revenue during the permissible credit period to make payment to the supplier at the end of the credit period. If it is not enough to pay off the purchasing cost of all items, the retailer will pay off the remaining balance by taking loan from the bank. So, the retailer starts paying for the interest charges on the amount of loan from the bank after the account is settled. Then the retailer will return money to the bank at the end of the inventory cycle. Under these conditions, we model the retailer?s inventory system as a cost minimization problem to determine the retailer?s optimal cycle time and optimal order quantity. Four cases are developed to efficiently determine the optimal cycle time and the optimal order quantity. Numerical examples are given to illustrate these cases. Comparing with Goyal?s model, we also find that the optimal cycle times in this paper are not longer than those of Goyal?s model.
Impact of defective items on (Q, r, L) inventory model involving controllable setup cost
Authors: Chuang Bor-Ren , Ouyang Liang-Yuh , Lin Yu-Jen
Published: November 2006

In a recent paper, Ouyang et al. [10] proposed a (Q, r, L) inventory model with defective items in an arrival lot. The purpose of this study is to generalize Ouyang et al.?s [10] model by allowing setup cost (A) as a decision variable in conjunction with order quantity (Q), reorder point (r) and lead time (L). In this study, we first assume that the lead time demand follows a normal distribution, and then relax this assumption by only assuming that the first two moments of the lead time demand are given. For each case, an algorithm procedure of finding the optimal solution is developed.
Realization of the chess mate solver application
Authors: Vuckovic Vladan
Published: November 2006

This paper presents details of the chess mate solver application, which is a part of the author?s Geniss general chess application. The problem chess is an important domain connected with solving of the chess problems. The Geniss Mate Solver (G.M.S.) application solves Mate-in-N-move problems. Main techniques used for the implementation of the application are full-width searching with Alpha-Beta pruning technique and zero evaluation function. The application is written in Delphi for Windows programming environment and the searching engine is completely coded in assembly language (about 10000 lines). This hybrid software structure enables efficient program development by using high-level programming environment and the realization of a very fast searching engine at the same time. The machine code is manually coded and could achieve above 7 million generated positions per second on the 1Ghz Celeron PC.
The operational flight and multi-crew scheduling problem
Authors: Stojkovic Mirela , Soumis François
Published: November 2006

This paper introduces a new kind of operational multi-crew scheduling problem which consists in simultaneously modifying, as necessary, the existing flight departure times and planned individual work days (duties) for the set of crew members, while respecting predefined aircraft itineraries. The splitting of a planned crew is allowed during a day of operations, where it is more important to cover a flight than to keep planned crew members together. The objective is to cover a maximum number of flights from a day of operations while minimizing changes in both the flight schedule and the next-day planned duties for the considered crew members. A new type of the same flight departure time constraints is introduced. They ensure that a flight which belongs to several personalized duties, where the number of duties is equal to the number of crew members assigned to the flight, will have the same departure time in each of these duties. Two variants of the problem are considered. The first variant allows covering of flights by less than the planned number of crew members, while the second one requires covering of flights by a complete crew. The problem is mathematically formulated as an integer nonlinear multi-commodity network flow model with time windows and supplementary constraints. The optimal solution approach is based on Dantzig-Wolfe decomposition/column generation embedded into a branch-and-bound scheme. The resulting computational times on commercial-size problems are very good. Our new simultaneous approach produces solutions whose quality is far better than that of the traditional sequential approach where the flight schedule has been changed first and then input as a fixed data to the crew scheduling problem.
Power unit-cargo space link in transport
Authors: Radmilovic Zoran , Dragovic Branislav , Maras Vladislav
Published: November 2006

This paper deals with transportation technology regarding links between power unit and cargo space. These links can be divided into two groups: rigid and flexible. Rigid link, established between power unit and cargo space, is dominant in maritime and road transport (sea ships and trucks), and occasionally in transport on inland waterways (self- propelled barges). Flexible link is used in the railroad transport (systems with trailers and semi trailers), and in inland waterway transport (push - towing and pulling systems, and combinations of the systems). The main goal of this research is determination of possible link types and organization of the means of transportation.
Large neighborhood local search for the p-median problem
Authors: Kochetov Yuri , Levanova Tatyana , Alekseeva Ekaterina , Loresh Maxim
Published: November 2006

In this paper we consider the well known p-median problem. We introduce a new large neighborhood based on ideas of S.Lin and B.W. Kernighan for the graph partition problem. We study the behavior of the local improvement and Ant Colony algorithms with new neighborhood. Computational experiments show that the local improvement algorithm with the neighborhood is fast and finds feasible solutions with small relative error. The Ant Colony algorithm with new neighborhood as a rule finds an optimal solution for computationally difficult test instances.
Scatter search based met heuristic for robust optimization of the deploying of "DWDM" technology on optical networks with survivability
Authors: Moreno-Pérez José , Melián-Batista Belén , Laguna Manuel
Published: November 2006

In this paper we discuss the application of a met heuristic approach based on the Scatter Search to deal with robust optimization of the planning problem in the deploying of the Dense Wavelength Division Multiplexing (DWDM) technology on an existing optical fiber network taking into account, in addition to the forecasted demands, the uncertainty in the survivability requirements.
Data warehousing and data mining: A case study
Authors: Suknovic Milija , Cupic Milutin , Martic Milan , Krulj Darko
Published: November 2006

This paper shows design and implementation of data warehouse as well as the use of data mining algorithms for the purpose of knowledge discovery as the basic resource of adequate business decision making process. The project is realized for the needs of Student's Service Department of the Faculty of Organizational Sciences (FOS), University of Belgrade, Serbia and Montenegro. This system represents a good base for analysis and predictions in the following time period for the purpose of quality business decision-making by top management. Thus, the first part of the paper shows the steps in designing and development of data warehouse of the mentioned business system. The second part of the paper shows the implementation of data mining algorithms for the purpose of deducting rules, patterns and knowledge as a resource for support in the process of decision making.
Interpolative relations and interpolative preference structures
Authors: Radojevic Dragan
Published: November 2006

Relations are very important mathematical objects in different fields of theory and applications. In many real applications, for which gradation of relations is immanent, the classical relations are not adequate. Interpolative relations (I-relations) (as fuzzy relations) are the generalization of classical relations so that the value (intensity) of a relation is an element from a real interval [0, 1] and not only from {0, 1} as in the classical case. The theory of I-relations is crucially different from the theory of fuzzy relations. I-relations are consistent generalizations of classical relations and, contrary to fuzzy relations, all laws of classical relations (set-theoretical laws) are preserved in general case. In this paper, the main characteristics of I-relations are illustrated on the interpolative preference structures (I-preference structures) as consistent generalization of classical preference structures.
Application of empirical Bayesian estimation to the optimal decision of a server-dependent queuing system
Authors: Lin Pei-Chun
Published: November 2006

This paper presents a decision model that uses empirical Bayesian estimation to construct a server-dependent M/M/2/L queuing system. A Markovian queue with a number of servers depending upon queue length with finite capacity is discussed. This study uses the number of customers for initiating and turning off the second server as decision variables to formulate the expected cost minimization model. In order to conform to the reality, we first collect data of interarrival time and service time by observing a queuing system, then apply the empirical Bayesian method to estimate its traffic intensity. In this research, traffic intensity is used to represent the demand for service facilities. The system initiates another server whenever the number of customers in the system reaches a certain length N and removes the second server as soon as the number of customers in system reduces to Q. Associating the costs with the opening of the second server and the waiting cost of customers, a relationship is developed to obtain the optimal value of N and Q to minimize cost. The mean number of customers in the system and the queue length of customers are derived as the characteristic values of the system. Model development and the implications of the data are discussed in detail.
Application of Electre III and DEA methods in the BPR of a bank branch network
Authors: Damaskos Xenofon , Kalfakakou Glykeria
Published: November 2006

Operational research methodologies are a powerful tool assisting managers in their effort to critically review business data and decide on future business actions. This paper presents the application of Electre multi-criteria methodology and Data Envelopment Analysis, as a part of a small commercial bank's ongoing effort to reengineer its branch network. We focus on two particular problems: first, categorization of the branches so as to apply adequate equivalent organizational schemas and second the assessment of relative efficiency of human resources.
An inventory model for deteriorating items with exponential declining demand and partial backlogging
Authors: Ouyang Liang-Yuh , Wu Kun-Shan , Cheng Mei-Chuan
Published: November 2006

This study proposes an EOQ inventory mathematical model for deteriorating items with exponentially decreasing demand. In the model, the shortages are allowed and partially backordered. The backlogging rate is variable and dependent on the waiting time for the next replenishment. Further, we show that the minimized objective cost function is jointly convex and derive the optimal solution. A numerical example is presented to illustrate the model and the sensitivity analysis is also studied.
Transport modeling: An artificial immune system approach
Authors: Teodorovic Dusan , Popovic Jovan , Lucic Panta
Published: November 2006

This paper describes an artificial immune system approach (AIS) to modeling time-dependent (dynamic, real time) transportation phenomenon characterized by uncertainty. The basic idea behind this research is to develop the Artificial Immune System, which generates a set of antibodies (decisions, control actions) that altogether can successfully cover a wide range of potential situations. The proposed artificial immune system develops antibodies (the best control strategies) for different antigens (different traffic "scenarios"). This task is performed using some of the optimization or heuristics techniques. Then a set of antibodies is combined to create Artificial Immune System. The developed Artificial Immune transportation systems are able to generalize, adapt, and learn based on new knowledge and new information. Applications of the systems are considered for airline yield management, the stochastic vehicle routing, and real-time traffic control at the isolated intersection. The preliminary research results are very promising.
On a volume flexible production policy in a family production context
Authors: Sana Sankar , Chaudhuri Kripasindhu
Published: November 2006

A mathematical model for a volume flexible manufacturing system is developed in a family production context, assuming that there exists a dedicated production facility as well as a separate management unit for each of the items. The possibility of machine breakdowns resulting in idle times of the respective management units is taken into account. The production rates are treated as decision variables. It is also assumed that there is a limitation on the capital available for total production. An optimal production policy is derived with maximization of profit as the criterion of optimality. The results are illustrated with a numerical example. Sensitivity of the optimal solution to changes in the values of some key parameters is also studied.
Concept of expert system for modal split in transportation planning
Authors: Popovic Maja , Jovic Jadranka
Published: November 2006

The objective of this paper is to develop a concept of expert system based on the survey of experts' opinions and their experience concerning relations in modal split, on the basis of parameters of transport system demand and transport supply, defined through PT travel time and city size, i.e. mean trip length. This expert system could be of use both to experts and less experienced planners who could apply the knowledge contained in this expert system for further improvement, on operational as well as on strategic level.
An implementation of ray tracing algorithm for the multiprocessor machines
Authors: Samardzic Aleksandar , Starcevic Dusan , Tuba Milan
Published: November 2006

Ray Tracing is an algorithm for generating photo-realistic pictures of the 3D scenes, given scene description, lighting condition and viewing parameters as inputs. The algorithm is inherently convenient for parallelization and the simplest parallelization scheme is for the shared-memory parallel machines (multiprocessors). This paper presents two implementations of the algorithm developed by the authors for alike machines, one using the POSIX threads API and another one using the OpenMP API. The paper also presents results of rendering some test scenes using these implementations and discusses our parallel algorithm version efficiency.
Placebo response in binge eating disorder
Authors: Jacobs‐Pilipski M. Joy , Wilfley Denise E. , Crow Scott J. , Walsh B. Timothy , Lilenfeld Lisa R.R. , West Delia Smith , Berkowitz Robert I. , Hudson James I. , Fairburn Christopher G.
Published: November 2006

Objective:

Placebo response in studies of binge eating disorder (BED) has raised concern about its diagnostic stability. The aims of this study were (1) to compare placebo responders (PRs) with nonresponders (NRs); (2) to investigate the course of BED following placebo response; and (3) to examine attributions regarding placebo response.

Method:

The baseline placebo run‐in phase (BL) was part of a RCT investigating sibutramine hydrochloride for BED; it included 451 participants, ages 19–63, diagnosed with BED. Follow‐up (FU) included 33 PRs.

Results:

In this study, 32.6% of participants responded to placebo (PRs = 147; NRs = 304). PRs exhibited significantly less symptom severity. At FU (n = 33), many PRs reported continued symptoms.

Conclusion:

PRs exhibited significantly less severe pathology than NRs. Placebo response in BED may transitory or incomplete. The results of this study suggest variable stability in the BED diagnosis. © 2006 by Wiley Periodicals, Inc. Int J Eat Disord 2007
What's driving the binge in binge eating disorder?: A prospective examination of precursors and consequences
Authors: Stein Richard I. , Kenardy Justin , Wiseman Claire V. , Dounchis Jennifer Zoler , Arnow Bruce A. , Wilfley Denise E.
Published: November 2006

Objective:

Previous research, mostly using retrospective reports, indicated a relation of negative affect and dietary restraint with the occurrence of binge episodes in binge eating disorder (BED). We employed Ecological Momentary Assessment (EMA) to better understand precursors and consequences of binge eating.

Method:

Thirty‐three females with BED carried a handheld computer for 7 days, and were periodically prompted to indicate their current emotions, hunger, and binge status.

Results:

Negative mood and hunger were significantly higher at prebinge than at nonbinge times, but negative mood was even higher at postbinge. Participants attributed binge episodes to mood more frequently than to hunger or abstinence violation.

Conclusion:

The finding that negative mood is actually heightened subsequent to a binge suggests the need to further investigate what is reinforcing about a binge, including possible escape from self‐awareness. Strengths of EMA technology are discussed, as well as its broad utility in BED assessment and treatment. © 2006 by Wiley Periodicals, Inc. Int J Eat Disord 2006
Spontaneous cervical lymphocele
Authors: Hekiert Adrianna , Newman Jason , Sargent Rachel , Weinstein Gregory
Published: November 2006

Background.

Primary (spontaneous) cervical lymphoceles in adults are extremely rare. More frequently occurring acquired cervical lymphoceles have been described in the setting of a neck trauma or after a neck dissection. We report a case of a spontaneous left cervical lymphocele in a previously asymptomatic female.

Methods and Results.

A 44‐year‐old woman presented with a 2‐month history of a left neck mass initially noted by her physician during a routine physical examination. She denied prior head and neck surgery or neck trauma. CT scan of the neck revealed a left cystic mass. Fine‐needle aspiration of the cyst yielded chylous material and lymphocytes. The surgical specimen grossly and microscopically was consistent with a lymphocele. The diagnosis was confirmed using D2‐40 antibody targeting lymphatic endothelial cells lining the cyst.

Conclusion.

Primary cervical lymphocele should be included in the differential diagnosis of a solitary neck mass in an adult. © 2006 Wiley Periodicals, Inc. Head Neck 2007
Exposure risk assessment and evaluation of the best management practice for controlling pesticide runoff from paddy fields. Part 1: Paddy watershed monitoring
Authors: Vu Son Hong , Ishihara Satoru , Watanabe Hirozumi
Published: November 2006

Rice pesticide concentrations in surface water along with hydrological balance and water management conditions were investigated in a paddy watershed of about 100 ha at the Sakura river basin in Tsukuba, Japan, for 3 years from April 2002. Monitoring on different hydrological scales ranging from a paddy plot up to a watershed determined the importance of water management associated with rainfall events and the cyclic irrigation for reducing pesticide discharge into aquatic environments. Surface drainage significantly increased as a response to rainfall events greater than about 1.5 cm day−1. A total of 16 herbicides were detected in the stream water and their peak concentrations mostly occurred from early to mid‐May following the pesticide application period. Two water management factors influencing the pesticide runoff from paddy fields were defined: excess water storage capacity (EWSC) and water holding period (WHP). Uncertainty analyses of pesticide discharge from a paddy plot for dymron (daimuron) and imazosulfuron (IMS) were performed using Monte Carlo simulation (MCS) with prescribed probability of rainfall and water management practice from observations over a period of 3 years. Application of an intermittent irrigation scheme with shallow water depth practice and high drainage gate to maintain the EWSC > 2 cm and increasing WHP from the current Japanese Agricultural Chemicals Regulation law of 3–4 days to at least 10 days were recommended for reducing the pesticide runoff from paddy fields in a monsoon region such as in Japan. The combination of good water management in field plots and small‐scale water cycling is the best management practice for controlling pesticide discharge from paddy watersheds. Copyright © 2006 Society of Chemical Industry
Improvement of cotton cloth soil removal by inclusion of alkaline cellulase from Bacillus sp. KSM‐635 in detergents
Authors: Hoshino Eiichi , Chiwaki Masahito , Suzuki Akira , Murata Moriyasu
Published: November 2006

Alkaline cellulase from Bacillus sp. KSM‐635 (EC 3.2.1.4) had reproducible detergent effects on cotton cloth that was artificially or naturally soiled with oily and/or particulate matter, under European washing conditions. The detergent effects of the cellulase, in combination with surfactants, apparently were the result of enzymatic action on amorphous regions of cotton fibers in which soil was trapped. The contribution of cellulase to soil removal increased as (i) the amount of soil in the amorphous regions of fibers in test fabrics was increased and (ii) the inhibition, by soil that adhered to the fibers' surfaces, of the action of the cellulase on fibers was reduced. Alkaline cellulase had the potential to replace, in part, both surfactants and zeolite in detergents, and it reduced washing time and allowed washing at lower temperatures under European washing conditions. The marked detergent effect of cellulase on naturally soiled cotton fabric was visually apparent, and it inhibited the accumulation of ash, calcium, and other inorganic components on cotton fibers during wash‐and‐wear cycles. These contributions of cellulase to the cleanliness of cotton fabrics were clearly increased by repeated wash‐and‐wear cycles. Cotton fabrics were not degraded by washing with the cellulase because effective hydrolysis by the cellulase occurred only in the amorphous regions of cotton fibers.
Self‐assembly of compounds based on a glycerin skeleton as a C‐3 building block. Part I
Authors: Urata Kouichi , Takaishi Naotake
Published: November 2006

Biological structures from proteins through viruses to cellular organelles with dimensions of 1 to 100 nm require molecular self‐assembly and self‐organization to form nanostructures. In contrast to covalent bonding, noncovalent interactions such as hydrogen bonding and hydrophobic association involve lower bond energies (2–20 kcal/mol) to attain the mobility and fluidity properties of biological structures. Noncovalent interactions are also well‐known with amphiphilic molecules bearing both hydrophilic head groups and hydrophobic groups and are responsible for the formation of several types of self‐assemblies such as micelles, liquid crystals, and lipid bilayers. As typical amphiphiles with a glycerin skeleton as a C‐3 building block, alkyl glyceryl ethers and their derivatives have been of interest since they show unique self‐assembly structures such as liquid crystals with hitherto unknown character.
Effect of hydrophobe structure on performance of alcohol ethoxylates
Authors: Genova Calogero , Schoenkaes Udo , Smith Dewey , Stolz Martin
Published: November 2006

Alcohol ethoxylates are versatile surfactants because both the hydrophobic and the hydrophilic moieties can be varied readily to change performance. Many studies have focused on the effect of changes in the average length of the hydrophobe and the nature of the hydrophile. Less frequently studied, however, has been the effect on performance of hydrophobe structure, yet this can be varied easily by changing the alcohol feedstock used to make the alcohol ethoxylate. This study compares the performance of alcohol ethoxylates derived from oleochemical alcohol and oxo‐alcohols derived from kerosene, butylene, or coal by the Fischer‐Tropsch process. Two aspects of hydrophobe structure were found to be important for performance of alcohol ethoxylates: the overall linearity of the parent alcohol and the degree of substitution at the C2 carbon. As the linearity of the parent alcohol increases, the critical micelle concentration (CMC) decreases and the surface tension at the CMC increases. Increasing substitution at the C2 carbon increases the amount of unethoxylated alcohol in the ethoxylate but decreases the inverse cloud point temperature, wetting time, and foam stability in the absence of soil.
Effects of a nonionic surfactant on the behavior of Bacillus amyloliquefaciens α‐amylase in the hydrolysis of malto‐oligosaccharide
Authors: Hoshino Eiichi , Tanaka Atsushi , Kanda Takahisa
Published: November 2006

The effects of a nonionic surfactant, polyoxyethylene mono‐N‐dodecyl‐ether (Brij 35; number of units of ethylene oxide moieties, 23), on the behavior of Bacillus amyloliquefaciens α‐amylase in the hydrolysis of maltoheptaose were studied at 25°C and pH 7.0. The addition of the surfactant to the enzyme‐substrate system increased the amount of reducing sugars during the hydrolysis. A high‐performance liquid chromatography technique was used for the determination of the hydrolysis products. During the hydrolysis, the concentration of maltose was increased by the addition of the surfactant, whereas the concentrations of other products were unchanged. Therefore, the increase in the amount of reducing sugars was thought to be due to the increase of the maltose fragment. Because the transglycosylation of hydrolyzed maltose takes place during the hydrolysis, the suppression of transglycosylation accelerates the production of total reducing sugars. The interaction between the maltose fragment and micelle surface might induce the release of this fragment from the enzyme active site and then suppress the transglycosylation. The bindings of the enzyme, the substrate, and/or the products to the micelle surface may affect the hydrolytic behavior including both the hydrolysis and transglycosylation catalytic conversions.
Models and methods for studying behavior in polyunsaturated fatty acid research
Authors: Mostofsky David I.
Published: November 2006

This report examines a range of models and procedures applicable to polyunsaturated fatty acid (PUFA) research and considers their relative merits. Considerations pertaining to cost, efficiency, and scientific rigor are of particular interest. parallel activities in other areas of behavioral neuroscience, such as behavioral pharmacology and toxicology, that have profitably exploited various behavior designs for the study of human and animal cognition are noted. Special attention is given to the utility of operant conditioning models and schedules of reinforcement, which are currently underrepresented in PUFA research. Investigations of analogs of complex human behavior as well as implications for generalizing laboratory results to clinical phenomena are addressed.
Stereochemistry of the hydroperoxides formed during autoxidation of CLA methyl ester in the presence of α‐tocopherol
Authors: Hämäläinen Taina I. , Sundberg Susanna , Hase Tapio , Hopia Anu
Published: November 2006

The initial steps in the autoxidation of CLA methyl ester are poorly understood. The aim of this study was to determine the stereochemistry of the hydroperoxides formed during autoxidation of CLA methyl ester in the presence of a good hydrogen atom donor. For this purpose, 9‐cis, 11‐trans CLA methyl ester was autoxidized in the presence of α‐tocopherol under atmospheric oxygen at 40°C in the dark. The CLA methyl ester hydroperoxides were isolated, reduced to the corresponding hydroxy derivatives, and separated by HPLC. The stereochemistry of seven hydroxy‐CLA methyl esters was investigated. The position of the hydroxy group was determined by GC‐MS. The geometry as well as the position of the double bonds in the alkyl chain was determined by NMR. In addition, the 13C NMR spectra of six hydroxy‐CLA methyl esters were assigned using COSY, gradient heteronuclear multiple bond correlation, gradient heteronuclear single quantum correlation, and total correlation spectroscopy experiments. The autoxidation of 9‐cis, 11‐trans CLA methyl ester in the presence of a good hydrogen atom donor is stereoselective in favor of one geometric isomer, namely the 13‐(R,S)‐hydroperoxy‐9‐cis, 11‐trans‐octadecadienoic acid methyl ester. Three types of conjugated diene hydroperoxides are formed as primary hydroperoxides: trans,trans hydroperoxides (12‐OOH‐8t,10t and 9‐OOH‐10t,12t), a cis,trans hydroperoxide with the trans double bond adjacent to the hydroperoxide‐bearing carbon atom (13‐OOH‐9c,11t), and a new type of cis,trans lipid hydroperoxide with the cis double bond adjacent to the hydroperoxide‐bearing carbon atom (8‐OOH‐9c,11t). In addition, three nonkinetic hydroperoxides (13‐OOH‐9t,11t, 8‐OOH‐9t,11t, and 9‐OOH‐10t,12c) are formed. This study supports the theory that CLA methyl ester autoxidizes at least partly through an autocatalytic free radical reaction. The complexity of the hydroperoxide mixture is due to formation of two different pentadienyl radicals. Moreover, the stereoslectivity in favor of one geometric isomer can be explained by the selectivity of the two previous steps: the preferential formation of a W‐conformer of the pentadienyl radical over the Z‐conformer, and regioselectivity of the oxygen addition to the pentadienyl radical.
Antihypertensive effects of a dietary unsaturated FA mixture in spontaneously hypertensive rats
Authors: Bellenger‐Germain S. , Poisson J. ‐P. , Narce M.
Published: November 2006

The aim of the present study was to investigate whether a mixture of dietary n−6 and n−3 PUFA could lower blood pressure in spontaneously hypertensive rats (SHR) of different ages. In addition, we studied how such a treatment could normalize the FA composition of plasma TAG and cholesterol esters (CE), and of red blood cell (RBC) total lipids. SHR (ages 4, 19, and 50 wk) were fed a normal diet (control groups) or a semisynthetic diet containing a mixture of γ‐linolenic acid (GLA), EPA, and DHA (experimental groups). Systolic blood pressure was measured at regular intervals. After 11 wk of consuming this diet, plasma TAG and CE were separated by TLC and analyzed for their FA composition. Total FA composition of RBC was also determined. The degree to which blood pressure was elevated was reduced in SHR after 11 wk of diet. The largest decrease was obtained with the oldest animals. In RBC, EPA and DHA contents increased. In plasma TAG and CE, EPA, DHA, and GLA increased whereas arachidonic acid decreased. The n−6 and n−3 unsaturated FA mix slowed the development of hypertension in young SHR and decreased blood pressure in adult and aged SHR. In addition, the present treatment altered the n−3 and n−6 PUFA content of SHR lipids to that seen in normotensive rats.
LDL binding to lipid emulsion particles: Effects of incubation duration, temperature, and addition of plasma subfractions
Authors: Chanson Nathalie F. , Lontie Jean‐Francois , Gulik Annette , Férézou Jacqueline , Carpentier Yvon A.
Published: November 2006

Lipid emulsions used in parenteral nutrition interact with lipoproteins leading to exchanges of lipids and acquisition of several apolipoproteins (apo). It has been previously observed that, during in vitro incubation of emulsions with purified LDL, a variable fraction of LDL binds to TG‐rich emulsion particles. The purpose of this study was to better characterize such an interaction. Two emulsions containing 20% soybean oil (Endolipid®, B. Braun AG, Melsungen, Germany) or fish oil were incubated with LDL, either alone or in the presence of various plasma subfractions, for different durations and at different temperatures. The fraction named M‐LE (containing TG‐rich particles modified after incubation) was separated by ultracentrifugation or gel filtration chromatography, and the apoB content was measured as an index of LDL binding to TG‐rich emulsion particles. The formation of such complexes was visualized by freeze‐fracture electron microscopy. LDL binding was not influenced by the method used for M‐LE isolation. Binding occurred quickly, did not increase with prolonged incubation, was inversely related to increasing incubation or ultracentrifugation temperature, and withstood 40 h of ultracentrifugation at 163,000×g. The presence of glycerol or excess phospholipids in the emulsion did not markedly affect the formation of the complexes. In contrast, adding very small amounts of lipoprotein‐poor plasma (d>1.210 g/mL) or HDL markedly reduced the process, and albumin had no effect. The TG composition of the emulsion influenced the binding of LDL to TG‐rich particles, since more apoB was found in M‐LE from fish oil than from soybean oil emulsion.
Effects of intermittent cycle exercise on intramyocellular lipid use and recovery
Authors: White Lesley J. , Robergs Robert A. , Sibbitt Wilmer L. , Ferguson Michael A. , McCoy Sean , Brooks William M.
Published: November 2006

The purpose of this investigation was to compare intramyocellular lipid (IMCL) changes in skeletal muscle in nine moderately trained subjects after 45 min of interval cycling and through 1 h of recovery. The exercise session was continous with alternating cycling intensity achieving 50 (3 min) and 110% (2 min) of ventilatory threshold. Spectra from the vastus lateralis were acquired before, immediately after, and 60 min following exercise using a 1.5 T Signa whole‐body magnet (point‐resolved spectroscopy sequence, echo time 60 ms, transverse relaxation time 2000 ms, 128 acquisitions, and 20 mm3 voxel). Immediately following exercise, IMCI concentration decreased 38% compared to pre‐exercise levels (P<0.05). Fitness level and baseline IMCL were not correlated with changes in IMCL following exercise (P>0.05). In the 60‐min recovery, IMCL was reduced 30% compared to baseline (P<0.05) and did not recover. In contrast, a nonexercising control group showed no change in IMCL. Our results suggest that IMCL decreased significantly following 45 min of interval cycling, with little recovery in the hour following.
Protective action on human LDL against oxidation and glycation by four organosulfur compounds derived from garlic
Authors: Ou Chu‐chyn , Tsao Shyh‐ming , Lin Ming‐cheng , Yin Mei‐chin
Published: November 2006

Human LDL were used to study the protective action of four organosulfur compounds (diallyl sulfide, DAS; diallyl disulfide, DADS; S‐ethylcysteine, SEC; N‐acetylcysteine, NAC) derived from garlic against oxidation and glycation. The four organosulfur compounds significantly inhibited superoxide production by xanthine‐xanthine oxidase (P<0.05) and showed marked copper‐chelating capability. DAS and DADS exhibited greater antioxidant activities against copper‐ and amphotericin B‐induced LDL oxidation (P<0.05) than SEC and NAC. However, SEC and NAC were more effective in sparing LDL α‐tocopherol (P<0.05). When oxidation was minimized, SEC was the most powerful agent against LDL glycation (P<0.05); however, DADS was superior to other agents in suppressing both oxidation and glycation when LDL oxidation occurred simultaneously with glycation. These results suggest that the four organosulfur compounds derived from garlic are potent agents for protecting LDL against oxidation and glycation, and that they may benefit patients with diabetes mellitus or cardiovascular diseases by preventing complications.
Effect of temperature and addition of α‐tocopherol on the oxidation of trilinolein model systems
Authors: Márquez‐Ruiz Gloria , Martín‐Polvillo Manuel , Dobarganes Carmen
Published: November 2006

The effects of temperature and addition of α‐tocopherol were evaluated in trilinolein model systems through quantification of oxidized TAG monomers, dimers, and polymers following oxidation at different temperatures. Samples of trilinolein without and with 250 and 500 mg/kg α‐tocopherol added were stored at 25, 60, and 100°C. Quantification of oxidized monomers, dimers, and polymers by a combination of adsorption and exclusion chromatography provided a useful measurement for studying the evolution of oxidation. Results showed that the amounts of primary oxidation compounds (trilinolein oxidized monomers) that accumulated during the induction period decreased as the temperature increased, indicating that the slope of the initial linear stage of oxidation depended on temperature. The end of the induction period was marked by a sharp increase in the levels of total oxidation compounds, the initiation of polymerization, and the loss of α‐tocopherol. Addition of α‐tocopherol did not prevent, but rather delayed, formation of trilinolein oxidized monomers and the initiation of polymerization.
Antagonism of croton oil inflammation by topical emu oil in CD‐1 mice
Authors: Yoganathan Subbiah , Nicolosi Robert , Wilson Thomas , Handelman Garry , Scollin Patrick , Tao Richard , Binford Paul , Orthoefer Frank
Published: November 2006

Emu oil is derived from the emu (Dromaius novaehollandiae), which originated in Australia, and has been reported to have anti‐inflammatory properties. Inflammation was induced in anesthetized CD‐1 mice by applying 50 μL of 2% croton oil to the inner surface of the left ear. After 2 h, the area was treated with 5μL of emu, fish, flaxseed, olive, or liquified chicken fat, or left untreated. Animals were euthanized at 6 h postapplication of different oils, and earplugs (FP) and plasma samples were collected. Inflammation was evaluated by change in earlobe thickness, increase in weight of EP tissue (compared to the untreated ear), and induction in cytokines interleukin (IL)‐1α and tumor necrosis factor‐α (TNF‐α) in EP homogenates. Al‐though reductions relative to control (croton oil) were noted for all treatments, auricular thickness and EP weights were, significantly reduced (−72 and −71%, respectively) only in the emu oil‐treated group. IL‐1α levels in homogenates of auricular tissue were significantly reduced in the fish oil (−57%) and emu oil (−70%) groups relative to the control group. The cytokine TNF‐α from auricular homogenates was significantly reduced in the olive oil (−52%) and emu oil (−60%) treatment groups relative to the control group. Plasma cytokine levels were not changed by croton oil treatment. Although auricular thickness and weight were significantly correlated with each other (r=0.750,P<0.003), auricular thickness but not weight was significantly correlated with cytokine IL‐1α (r=0.750,P<0.006) and TNF‐α (r=0.690,P<0.02). These studies indicate that topical emu oil has anti‐inflammatory properties in the CD‐1 mouse that are associated with decreased auricular thickness and weight, and with the cytokines IL‐1α and TNF‐α.