bluuebunny/crossref_metadata_2025 huggingface dataset:
A complete constructive algorithm for the general mixed linear programming problem
Authors: Graves Glenn W.
Published: May 2007

An algorithm that seems to have several advantages for application to the general mixed linear programming problem is described. Although it does not make any non‐degeneracy assumption or stipulate conditions for consistency of constraints or finiteness of extrenal value, it has the following distinct advantages: (1) it does away with all augmentation for any reason, in particular “artificial variables” for “initial feasible solutions” and the doubling of rows and columns for equations and variables of arbitrary sign; (2) it does not resort to any perturbation technique or arbitrary cycling of “basis” to cope with the “degeneracy problem,” but instead shows how to capitalize on it by concentrating on a greatly restricted subset of rows and columns; (3) it isolates and identifies inconsistent constraints in a simple, natural way; and (4) it features a small segregated inverse of a “basic kernel,” opening the way to easy generation of elements techniques with large sparse systems.
Utility functions of money for clear games
Authors: Peleg Bezalel
Published: May 2007

In this paper we discuss the question of clearness of K‐games for catalogues as defined by Jentzsch in Ref. [4]. It is proved that when the coalition K has at least two members, a necessary and sufficient condition that all money games played by K will be clear is that the utility functions for money of the players of K are linear in money. In the proof we assume that the utility functions are concave.
Finding the inverse and connections of a type of large sparse matrix
Authors: Hershkowitz Martin , Noble Stedman B.
Published: May 2007

Much interest is being shown in methods for determining structure of matrices in order to simplify computation. This paper takes a slightly different approach, giving an algorithm that determines the structure of a matrix while inverting it. The algorithm applies to matrices with dominant diagonal or similar matrices that can be inverted using the C. Neumann series. This series is decomposed into terms which are products of connected coefficients: the procedure lends itself to an efficient method of truncation that obtains an approximation to the inverse matrix. While this algorithm might not be efficient for some matrices, it is quite efficient for the 430‐order Minkowski‐Leontief matrix upon which it was tested. Furthermore, the computation enumerates the connections in the matrix; hence the model can be “tested” by comparing the connections of the model with those known to exist in the underlying phenomena.
The minimal cost flow problem with convex costs
Authors: Menon V. V.
Published: May 2007

A new characterization of the solution to the transshipment problem where the cost of transporting along each route is a convex function of the amount shipped, is presented. The method of proof, that of using network theoretic methods, is elementary. Notion of duality, or the Kuhn‐Tucker theorem, are not used, and a “Primal” algorithm to solve the problem is outlined.
A conservation law for a wide class of queueing disciplines
Authors: Kleinrock Leonard
Published: May 2007

A large class of queueing disciplines is defined for Poisson arrival statistics. For this class, a Conservation Law is proven which constrains the allowed variation in the average waiting times. Specifically, defining ρp as the product of the average arrival rate and the average service time for customers from the pth priority group (where the priority system is any queue discipline included in the defined class) and Wp as their average waiting time (in queue), the Conservation Law states that Σ ρp Wp is invariant over the set of queue disciplines in the class.
Characteristic functions of stochastic integrals and reliability theory
Authors: Antelman Gordon , Savage I. Richard
Published: May 2007

This paper concerns reliability theoretic problems involving systems of n components subject to stochastic hazard rates with independent increments. General methods are given for finding the probabilities of service at specified times and the joint characteristic function of the system failure time and the component hazard rates at the time of failure. These methods involve evaluation of integrals of the formmagnified imagewhere u′ is an n‐component row vector, W(t) is an n by n matrix, and X(t) is an n‐component stochastic process with independent increments and X(0) = 0. Some illustrative applications to one component systems and multicomponents systems in series and in parallel are presented.
The distribution of the time‐duration of stochastic duels
Authors: Ancker C. J. , Gafarian A. V.
Published: May 2007

The Theory of Stochastic Duels is extended by considering the distribution of time‐to‐completion of the fundamental duel. The model has fixed kill probabilities and either random or fixed time between rounds fired. Time‐limitation is included. Special cases and examples are worked out. Clearly, the time‐duration of combat has both tactical and logistic implications for the decision‐maker.
Queues with batch poisson arrivals and hyper‐exponential service
Authors: Cupta S. K. , Goyal J. K.
Published: May 2007

We consider in this paper the queueing system in which the input is in batches of variable numbers following a Poisson distribution; queue discipline is “first come first served,” it being assumed that the batches are preordered for service purposes; and service time distribution is hyperexponential with n branches. The Laplace transform of the system size distribution is determined by applying the method of generating functions, devised by Bailey [1] . Some of the known results are derived as particular cases.
Time‐cost tradeoffs in uncertain empirical research projects
Authors: Scherer F. M.
Published: May 2007

This paper explores the relationship between research project cost and expected time to completion under various scheduling strategies; it assumes that many potential technical approaches to the research problem can be identified; and that each approach has a low but finite subjective probability of success. It is shown that under a variety of assumptions, expected time to project completion can be reduced, but that as a result expected project cost rises at an increasing rate. Some cases in which this convex time‐cost tradeoff relationship might not hold generally are identified. When the time‐cost tradeoff function is convex, the desirability of concurrent as opposed to series scheduling of approaches depends crucially upon the depth of the stream of benefits expected to be realized upon successful project completion. The deeper the benefit stream is, the more desirable concurrent scheduling is.
Toward a multi‐stage information conversion model of the research and development process
Authors: Brandenburg Richard G. , Stedry Andrew C.
Published: May 2007

Research and development activities in a business firm or government laboratory are portrayed as a multi‐stage information generation and conversion process. A “basic research” phase generates opportunities, in the form of findings in a set of scientific disciplines, which are available for subsequent exploitation. It is assumed that increments to information in a subject area are stochastic, proportional to the amount of knowledge which already exists in the area, and have values which are randomly distributed. An “exploratory development” phase is viewed as a process of selecting a subset of alternative research opportunities, improving each opportunity in the direction of its applications, estimating the value of the improved opportunity and using these estimates to choose the exploratory development results to be implemented in engineering development. The “engineering development” phase makes the value of exploratory results realizable without changing value or risk. Engineering development costs are assumed to increase as value increases. If exploratory development is not successful, additional costs in engineering development must be incurred to bring the design up to a minimum desirable level. The model is intended as a step toward formulating and analyzing problems in management planning and control of the several interrelated stages of the research and development process.
Minimizing reductions in readiness caused by time‐phased decreases in aircraft overhaul and repair activities
Authors: Bracken Jerome , Simmons Kendall W.
Published: May 2007

The Navy is often required to conduct personnel planning studies, A recent study on the assessment of effects of personnel reductions at the various aircraft Overhaul and Repair Activities (O & Rs) of the Bureau of Naval Weapons was carried out by one of the writers of the present paper. The methodology was systematic but relied on informal, judgmental decision procedures rather than on formal models incorporating optimization. Later study of the problem resulted in the approach described herein.

The paper addresses this question: How can a personnel reduction in the Navy's aircraft O & Rs be distributed among activities with minimum reduction in readiness? A two‐stage procedure involving linear programming models is developed. Solutions involve either extensions of aircraft overhaul cycles or a combination of such extensions with reductions in aircraft inventories.
Use of dimensionless ratios to determine minimum‐cost inventory quantities
Authors: Herron David P.
Published: May 2007

The iteration usually necessary for simultaneous determination of minimum‐cost order quantity and reorder point in (Q, r) inventory systems may be eliminated by a graphical technique employing dimensionless ratios. This technique is illustrated for three different types of stock‐out penalty.
Use of completely reduced matrices in solving transportation problems with fixed charges
Authors: Dwyer Paul S.
Published: May 2007

This paper shows how completely reduced matrices can be used in obtaining exact or approximate solutions to transportation problems with fixed charges. It does not treat methods for obtaining reduced matrices, which are available elsewhere, but it does discuss the problem of obtaining a completely reduced matrix, and then a general parametric solution to the primal problem, from any particular solution. Methods for obtaining particular solutions with determinacies of maximum order (solutions for the constant fixed charges problem) are then presented. The paper terminates with a discussion of methods which are useful in obtaining approximations to solutions of fixed charges problems with charges not constant.
Optimal policy for a dynamic multi‐echelon inventory model
Authors: Bessler Stuart A. , Veinott Arthur F.
Published: May 2007

A general multiperiod multi‐echelon supply system consisting of n facilities each stocking a single product is studied. At the beginning of a period each facility may order stock from an exogenous source with no delivery lag and proportional ordering costs. During the period the (random) demands at the facilities are satisfied according to a given supply policy that determines to what extent stock may be redistributed from facilities with excess stock to those experiencing shortages. There are storage, shortage, and transportation costs. An ordering policy that minimizes expected costs is sought. If the initial stock is sufficiently small and certain other conditions are fulfilled, it is optimal to order up to a certain base stock level at each facility.

The special supply policy in which each facility except facility 1 passes its shortages on to a given lower numbered facility called its direct supplier is examined in some detail. Bounds on the base stock levels are obtained. It is also shown that if the demand distribution at facility j is stochastically smaller (“spread” less) than that at another facility k having the same direct supplier and if certain other conditions are fulfilled, then the optimal base stock level (“virtual” stock out probability) at j is less than (greater than) or equal to that at facility k.
An attack‐defense game with matrix strategies
Authors: Cohen N. D.
Published: May 2007

This paper presents the results and the method of analysis for an attack‐defense game involving allocation of resources. Each player is assumed to have several different types of resources to be divided in optimal fashion among a fixed set of targets. The payoff function of the game is convex.

The “No Soft‐Spot” principle of M. Dresher, and the concept of the generalized inverse of a matrix are used to determine optimal strategies for each player and the value of the game.
Alliance games of n‐persons
Authors: Eisenman Richard L.
Published: May 2007

A generalization of n‐person games, called “Alliance Games.” is defined. The relations with von Neumann and Morgenstern's games and with Thrall's games in partition function form are shown. The conceptual value of alliance games is discussed, and the mathematical value is illustrated by answering questions which Thrall raised concerning points between partitions.
On queueing systems with variable service capacities
Authors: Yadin M. , Naor P.
Published: May 2007

In some queueing systems the total service capacity utilized at any given time is a variable under the control of a decision maker. Management doctrines are examined which prescribe the actual service capacity as a function of the queue length and the recent history of the system. Steady state probabilities, expected queue lengths and frequencies of change in capacity are evaluated for a wide class of possible control schemes. Optimization procedures are outlined.
Inventory control of a multiproduct system with a limited production resource
Authors: Evans Richard V.
Published: May 2007

Optimal control of the production of several products subject to restricted production resources is considered. Linear production, holding and penalty costs are assumed although this is crucial only for production costs. Excess demand results in lost sales. A single point plays an important role in the definition of the optimal policy.
Programming the procurement of airlift and sealift forces: A linear programming model for analysis of the least‐cost mix of strategic deployment systems
Authors: Fitzpatrick George R. , Bracken Jerome , O'brien Mary J. , Wentling Lee G. , Whiton Justin C.
Published: May 2007

A linear programming model for analyzing the strategic deployment mix of airlift and sealift forces and prepositioning to accomplish the composite requirements of a set of possible contingencies is described in this paper. It solves for the least‐cost mix of deployment means capable of meeting any one of a spectrum of contingencies, or meeting simultaneous contingencies. The model was developed by RAC as part of the U.S. Army's study program and has been used in analyses of deployment systems conducted in support of the U.S. Army, the Joint Chiefs of Staff and the Office of the Secretary of Defense. Results of analyses have influenced the preparation of long‐range plans as well as the formulation of the FY67 Department of Defense budget. The paper gives the background and assumptions of the model, describes the model by means of a simple hypothetical example followed by a selected subset of a complete version, and discusses how the model is used.
On some stocxastic tactical antisubmarine games
Authors: Charnes A. , Schroeder R. G.
Published: May 2007

Mathematical models of tactical problems in Hntisubmarine Warfare (ASW) are developed. Specifically, a game of pursuit between a hunter‐killer force. player 1, and a possible submarine, player 2 is considered. The game consists of a sequence of moves and terminates when player 2 is tcaught or evades player 1. When the players move they observe the actual tactical configuration of the forces (state) and each player choosa‐s a tactical plan from a finite collection. This joint choice of tactical plans determines an immediate payoff and a transition probability distribution over the states. Hence an expected payoff function is defined, Formally this game is a Terminating Stochastic Game (TSG). Shapley demonstrated the existence of a value and optimal strategies (solution), An iterative technique to approximate the solution to within desired accuracy is proposed. Each iteration of the technique is obtained by solving a set of linear programs. To introduce more realism into the game several variations of the TSG are also considered. One variation is a finite TSG and linear programming techniques are employed to find the solution.
Linear programming and the reliability of multicomponent systems
Authors: Kolesar Peter J.
Published: May 2007

Several problems in the assignment of parallel redundant components to systems composed of elements subject to failure are considered. In each case the problem is to make an assignment which maximizes the system reliability subject to system constraints. Three distinct problems; are treated. The first is the classical problem of maximizing system reliability under total cost or weight constraints when components are subject to a single type of failure. The second problem deals with components which are subject to two types of failure and minimizes the probability of one mode of system failure subject to a constraint on the probability of the other mode of system failure. The third problem deals with components which may either fail to operate or may operate prematurely. System reliability is maximized subject to a constraint ori system safety.

In each case the problem is formulated as an integer linear program. This has an advantage over alternative dynamic programming formulations in that standard algorithms may be employed to obtain numerical results.
Bayes sequential strategies for crossing a field containing absorption points
Authors: Zacks S.
Published: May 2007

A sequential decision problem is considered in which N particles have to cross a given field. Two alternative crossing paths are available. An unknown number of absorption points J1 and J2 are planted at each of the crossing paths. The bivariate prior distribution of (J1,J2) is given. If a particle passes close to an absorption point it may survive with probability s, 0 < s < 1. If a particle is absorbed, both the particle and the absorption point are ruined. There is no replacement of ruined absorption points. All absorption points act independently. The particles crciss the field in a consecutive order, and a crossing path can be chosen for each particle. The objective is to maximize the expected number of survivors. The Bayes sequential procedure is characterized. The csmditions under which the Bayes strategy is determined by the maximal posterior survival probabilities are specified.
A deterministic inventory model for reparable items
Authors: Schrady David A.
Published: May 2007

A reparable inventory system has two distinct inventories within it—the inventory of items ready‐for‐issue and the inventory of carcasses available for repair. A reparable item is usually rebuilt upon failure, but the scrap rate in the repair process is generally positive. Consequently, new items must be procured from time to time to replace those item: which were scrapped. The ready‐for‐issue inventory has two input sources—procurement and repair, This paper develops a deterministic inbentory model for the reparable inventory system, and determines the optimal procurement and repair quantities.
A comparison of usage data among types of aircraft
Authors: Haber Sheldon E.
Published: May 2007

It has long been an accepted proposition that base level usage df technical repair items for aircraft is related to program elements. The program element most often cited in this connection is flying hours. Evidence of this relationship on a line item basis, however, has been sparse. This study suggests that although the supposed relation is intuitively plausible, for most line items it cannot be effectively utilized in projecting base level requirements. The basis of this conclusion is an analysis of demand characteristics for technical repair items for a variety of naval aircraft.
The probability of survival of a subterranean target under mtensive attack
Authors: Harris Bernard , Karreman Herman F. , Rosser J. Barkley
Published: May 2007

This paper deals with the analysis of a model for studying the probability of survival of a subterranean target under an intensive attack. Most of the analysis is based on the assumption that the explosions are circularly distributed about the target and that the number of explosions is known. In the last two sections it is shown what effect a relaxation of these assumptions has on the probability of survival of the target.
Minimax surveillance schedules for replaceable units
Authors: Roeloffs Robert
Published: May 2007

An analysis is made of the problem of finding optimal schedules for checking an operating unit subject to random failure detectable only by inspection of the unit. It is assumed that only partial information, in the form of .a single percentile of the otherwise unknown life distribution of the unit, is available. In a previous paper [5] some results were given for the case with a finite time horizon. Tn this work it is assumed that tne unit is replaceable at will with a new, statistically identical unit, and the horizon is infinite.
Allocation of resources to randomly occurring opportunities
Authors: Donis John N. , Pollock Stedhen M.
Published: May 2007

An allocation problem is considered in lvhich different kinds of resources must be allocated to various activities, within a given time period. The opportunities for allo'cation appear randomly during this period. Certain assumptions about the values of possible allocations and the distribution of occurrences of opportunities lead to a dynamic programming formulation of the problem. This leads to a system of ordinary differential equations which are (in theory) solvable recursively, and can be solved numerically to any desired degree of precision.

An example is given for the allocation of aircraft‐carried weapons to targets of opportunity.
Pursuit around a hole
Authors: Isbell J. R.
Published: May 2007

The solution of isaacs1 problem of optimal pursuit in a plane with a circular disk removed, given constant speeds, zero turning radius, and perfect visibility for both players is presented herein. The hole has three effects: the trivial effect that shortest paths are not straight, the trapping effect to turn the evader from running into the hole, and the screening effect causing an evader retreating behind the hole not to retreat across a line through its center.
The fixed charge problem
Authors: Steinberg David I.
Published: May 2007

The fixed charge problem is a nonlinear programming problem of practical interest in business and industry. Yet, until now no computationally feasible exact method of solution for large problems had been developed.

In this paper an exact algorithm is presented which is computationally feasible for large problems. The algorithm is based upon a branch and bound approach, with the additional feature that the amount of computer storage required remains constant throughout (for a problem of any given size).

Also presented are three suboptimal heuristic algorithms which are of interest because, although they do not guarantee that the true optimal solution will be found, they usually yield very good solutions and are extremely rapid techniques.

Computational results are described for several of the heuristic methods and for the branch and bound algorithm.
On computing the expected discounted return in a markov chain
Authors: Hitchcock David F. , Macqueen James B.
Published: May 2007

The discounted return associated with a finite state Markov chain X1, X2… is given by g(X1)+ αg(X2) + α2g(X3) + …, where g(x) represents the immediate return from state x. Knowing the transition matrix of the chain, it is desired to compute the expected discounted return (present worth) given the initial state. This type of problem arises in inventory theory, dynamic programming, and elsewhere.

Usually the solution is approximated by solving the system of linear equations characterizing the expected return. These equations can be solved by a variety of well‐known methods. This paper describes yet another method, which is a slight modification of the classical iterative scheme. The method gives sequences of upper and lower bounds which converge mono‐tonely to the solution. Hence, the method is relatively free of error control problems.

Computational experiments were conducted which suggest that for problems with a large number of states, the method is quite efficient. The amount of computation required to obtain the solution increases much slower with an increase in the number of states, N, than with the conventional methods. In fact, computational time is more nearly proportional to N2, than to N3.
Businessmen in politics
Authors: Reid Thomas R.
Published: May 2007

Corporations are advised to be active in their own interest and to promote better government.
Rural fears allayed
Authors: Hein Clarence J.
Published: May 2007

Department of Agriculture economist sees no diminishing of attention to non‐urban services.
Breaking traffic jam
Authors: Stouffer Lloyd
Published: May 2007

Television, radar, electronic computers and psychology loosen grip of highway congestion.
A note on constraint preconditioners for nonsymmetric saddle point problems
Authors: Lin Yiqin , Wei Yimin
Published: May 2007

A class of constraint preconditioners for solving two‐by‐two block linear equations with the (1,2)‐block being the transpose of the (2,1)‐block and the (2,2)‐block being zero was investigated in a recent paper of Cao (Numer. Math. 2006; 103:47–61). In this short note, we extend his idea by allowing the (1,2)‐block to be not equal to the transpose of the (2,1)‐block. Results concerning the spectrum, the form of the eigenvectors and the convergence behaviour of a Krylov subspace method, such as GMRES are presented. Copyright © 2007 John Wiley & Sons, Ltd.
Preparation and application of polystyrene‐grafted ZnO nanoparticles
Authors: Hong R. Y. , Chen L. L. , Li J. H. , Li H. Z. , Zheng Y. , Ding J.
Published: May 2007

The precursor of ZnO was prepared by precipitation and ZnO nanoparticles were obtained by calcination afterwards. Poly(styrene) (PSt) was grafted onto the ZnO nanoparticles in a non‐aqueous suspension to reduce the aggregation among nanoparticles and to improve the compatibility between nanoparticles and the organic matter. The obtained samples were characterized by X‐ray powder diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT‐IR), zeta potential measurement, lipophilic degree (LD) test, photocatalytic experiments, sedimentation test, and contact angle measurement. The LD of composite particles after a high‐temperature treatment was stable. The photoluminescence of PSt‐grafted ZnO nanoparticles was observed by naked eyes and was recorded using a digital camera. The ZnO nanoparticles were used to reinforce poly(vinylidene fluoride) (PVDF) films and the mechanical and electric properties of the films were also measured. Copyright © 2007 John Wiley & Sons, Ltd.
Preparation, characterization and performances of biodegradable thermoplastic starch
Authors: Wang Hong‐Yuan , Huang Ming‐Fu
Published: May 2007

A biodegradable thermoplastic starch (TPS) was successfully prepared from plasticizer ethanolamine and native cornstarch. The hydrogen bonding interaction between starch and ethanolamine was investigated using Fourier transform infrared (FT‐IR). When the ethanolamine mass content was 30%, after the ethanolamine‐plasticized thermoplastic starch (ETPS) was stored at RH 50% for 14 days, the mechanical testing showed that the maximum tensile stress of the ETPS reached 5.98 MPa, the tensile strain reached 106.52%, Young's modulus increased from 38.14 MPa of glycerol‐plasticized thermoplastic starch (GTPS) to 75.32 MPa of ETPS, and the breaking energy increased from 1.921 N·m to 2.305 N·m, which indicated that the mechanical properties of ETPS evidently excelled those of the GTPS. The effects of water contents on the mechanical properties of ETPS and GTPS were studied. A differential scanning calorimetry (DSC) analysis revealed that the low‐temperature transition and the glass transition temperature (Tg) of the ETPS were −58 and 22°C respectively, which were lower than that of the GTPS. The ETPS effectively restrained the re‐crystallization of traditional GTPS, which was proved by the X‐ray diffraction (XRD). The scanning electron microscopy (SEM) images presented that ethanolamine made starch uniform. Copyright © 2007 John Wiley & Sons, Ltd.
Parabolas of medication use and discontinuation after myocardial infarction—are we closing the treatment gap?
Authors: Hudson Marie , Richard Hugues , Pilote Louise
Published: May 2007

Purpose

Little is known on the use of evidence‐based medications in patients with acute myocardial infarction (AMI) across all ages. We undertook this study to describe the patterns of prescription and discontinuation of anti‐platelet agents, beta‐blockers, angiotensin converting enzyme (ACE) inhibitors and/or angiotensin receptor blockers (ARBs) and statins in all patients post‐AMI.

Methods

Using population‐based administrative databases, patients with an AMI between 1999 and 2004 (21 494 men and 13 241 women) were identified. Rates of prescriptions after discharge and time to discontinuation of the study drugs were computed for various age groups.

Results

The proportion of patients prescribed a study drug increased throughout the study period. In 2003–2004, 90% of patients were prescribed an anti‐platelet agent, 77% a beta‐blocker, 72% a statin and 70% an ACE inhibitor and/or an ARB within 30 days of discharge from their AMI. However, the rates of discontinuation increased significantly during follow‐up and, in men, reached 27% by 2 years and 42% by 5 years for beta‐blockers. The rates of discontinuation of all four study drugs had a parabolic shape with the youngest and oldest patients having the highest rates.

Conclusions

The use of evidence‐based drugs for patients after AMI is increasing. However, efforts aimed at closing the treatment gap may be mitigated by high rates of discontinuation, especially in patients at the extremes of the age spectrum. Copyright © 2007 John Wiley & Sons, Ltd.
Laser isolation of shunted regions in industrial solar cells
Authors: Abbott M. D. , Trupke T. , Hartmann H. P. , Gupta R. , Breitenstein O.
Published: May 2007

This paper provides proof of concept for a technique that uses laser‐ablated grooves to locally isolate shunted regions in industrial silicon solar cells. The shunted regions are located using photoluminescence imaging and then isolated from the active cell area with a Nd:YAG laser. By applying this shunt isolation technique, we demonstrate that a strongly shunted 9·6% efficient industrial screen‐printed solar cell could be recovered to 13·3%. With further development this technique could be applied in an industrial environment to mitigate yield losses and improve average cell efficiencies. Copyright © 2007 John Wiley & Sons, Ltd.
Epoxies toughened with triblock copolymers
Authors: Hydro Ryan M. , Pearson Raymond A.
Published: May 2007

Three different commercial triblock copolymers from Arkema were evaluated as potential toughening agents for two different lightly crosslinked epoxies. It was found that the plane strain fracture toughness, KIC, was on the order of 3.0 MPa√m for 10 parts per hundred resin (phr) of NanoStrength™ E20 resin (a styrene–butadiene–methylacrylate, SBM, type triblock copolymer) in epoxies cured with either aminoethylpiperazine or piperidine. In contrast, 10 phr NanoStrength E40 resin (also an SBM type triblock copolymer) was ineffective in toughening such epoxies. The difference in toughening effectiveness was attributed to the smaller amount of polybutadiene present in the E40 resin. The third toughening agent from Arkema was NanoStrength M22 resin, which is a symmetric triblock copolymer consisting of side blocks of PMMA surrounding a center block of poly(butyl acrylate) and is designated as MAM. At 10 phr MAM both lightly crosslinked epoxies exhibited improvements in toughness. Morphologies were characterized using TEM and toughening mechanisms revealed using SEM and TOM. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 1470–1481, 2007
Pseudomonas‐induced defence molecules in rice plants against leaffolder (Cnaphalocrocis medinalis) pest
Authors: Saravanakumar Duraisamy , Muthumeena Kannappan , Lavanya Nallathambi , Suresh Seetharaman , Rajendran Lingan , Raguchander Thiruvengadam , Samiyappan Ramasamy
Published: May 2007

Fluorescent pseudomonad strains Pf1, TDK1 and PY15 individually and in combination were evaluated against leaffolder, Cnaphalocrocis medinalis Guen., in rice under in vitro, glasshouse and field conditions. Among the various treatments used, a combination of Pf1, TDK1 and PY15 strains effectively reduced the incidence of leaffolder pest in rice plants to an extent comparable with chlorpyrifos‐methyl. In addition, morphogenesis of the insect pest in all stages, larval, pupal and adult, was greatly affected by a combination of Pseudomonas Pf1, TDK1 and PY15 strains. Further, the induction of defence‐related molecules was demonstrated. An increased accumulation of defence molecules such as chitinase and proteinase inhibitors was observed with a combined Pf1, TDK1 and PY15 treatment compared with all other treatments. Western blot analysis of chitinase revealed the extra induction of 18, 28 and 35 kDa isoforms in rice plants treated with a mixture of Pf1, TDK1 and PY15 strains against leaffolder pest. The study revealed that a combination of fluorescent pseudomonad strains affects the development of leaffolder pest by inducing defence molecules in rice plants which in turn enhance resistance to leaffolder attack. Copyright © 2007 Society of Chemical Industry
Inhibition of pheromone response inSesamia nonagrioidesby the pheromone of the sympatric corn borer,Ostrinia nubilalis
Authors: Eizaguirre Matilde , Albajes Ramon , López Carmen , Sans Albert , Gemeno César
Published: May 2007

Sesamia nonagrioidesLef. andOstrinia nubilalis(Hübn.) are two corn borers present in the Mediterranean area that share a similar feeding habitat. The female sex pheromones of the two species consist of (Z)‐11‐hexadecenyl acetate, (Z)‐11‐hexadecen‐1‐ol, (Z)‐11‐hexadecenal and dodecyl acetate (77:8:10:5 w/w) and (Z)‐11‐tetradecenyl acetate and (E)‐11‐tetradecenyl acetate (97:3 w/w) respectively. Although the pheromones share no common components, previous work had shown the inhibition of the response byO. nubilalismales to their own pheromone owing to the presence ofS. nonagrioidespheromone. In this study, the pheromone ofO. nubilalisand its two components separately were shown to inhibit the attraction ofS. nonagrioidesmales to the synthetic female pheromone in both laboratory wind‐tunnel bioassay and field trapping studies. In the wind tunnel, the number of contacts ofS. nonagrioidesmales with the source were significantly (P< 0.05) reduced by the single pheromone components ofO. nubilalis. In the field, the addition of 1% ofO. nubilalispheromone significantly (P< 0.05) reduced the catches ofS. nonagrioidesmales. The components of both pheromones also elicited electroantennographic responses from antennae of maleS. nonagrioidesmoths. The ecological consequences and the possibilities of applying this cross‐inhibition for mating disruption techniques are discussed. Copyright © 2007 Society of Chemical Industry
Resistance to spinosad in the western flower thrips, Frankliniella occidentalis (Pergande), in greenhouses of south‐eastern Spain
Authors: Bielza Pablo , Quinto Vicente , Contreras Josefina , Torné María , Martín Alberto , Espinosa Pedro J
Published: May 2007

Susceptibility to spinosad of western flower thrips (WFT), Frankliniella occidentalis (Pergande), from south‐eastern Spain was determined. LC50 values of the field populations without previous exposure to spinosad collected in Murcia in 2001 and 2002 ranged from 0.005 to 0.077 mg L−1. The populations collected in Almeria in 2003 in greenhouses were resistant to spinosad (LC50 > 54 mg L−1) compared with the authors' highly susceptible laboratory strain. The highly sensitive laboratory strain leads to very high resistance ratios for the field populations (>13 500), but these ratios do not necessarily mean resistance problems and control failures (spinosad field rate 90–120 mg L−1). The populations collected in Murcia from some greenhouses in 2004 were also resistant to spinosad (RF > 3682). Spinosad overuse, with more than ten applications per crop, produced these resistant populations in some greenhouses. Spinosad showed no cross‐resistance to acrinathrin, formetanate or methiocarb in laboratory strains selected for resistance towards each insecticide. Correlation analysis indicated no cross‐resistance among spinosad and the other three insecticides in 13 field populations and in nine laboratory strains. The synergists piperonyl butoxide (PBO), S,S,S‐tributyl phosphorotrithioate (DEF) and diethyl maleate (DEM) did not enhance the toxicity of spinosad to the resistant strains, indicating that metabolic‐mediated detoxification was not responsible for the spinosad resistance. These findings suggest that rotation with spinosad may be an effective resistance management strategy. Copyright © 2007 Society of Chemical Industry
Comparison of the subchronic antidiabetic effects of DPP IV–resistant GIP and GLP‐1 analogues in obese diabetic (ob/ob) mice
Authors: Irwin Nigel , McClean Paula L. , Flatt Peter R.
Published: May 2007

Glucagon‐like peptide‐1 (GLP‐1) and glucose‐dependent insulinotropic polypeptide (GIP) are the two key incretin hormones released from the gastrointestinal tract that regulate blood glucose homeostasis through potent insulin secretion. The rapid degradation of GIP and GLP‐1 by the ubiquitous enzyme dipeptidyl peptidase IV (DPP IV) renders both peptides noninsulinotropic. However, DPP IV stable agonists, such as N‐AcGIP and (Val8)GLP‐1, have now been developed. The present study has examined and compared the metabolic effects of subchronic administration of daily i.p. injections of N‐AcGIP, (Val8) GLP‐1 and a combination of both peptides (all at 25 nmol/kg bw) in obese diabetic (ob/ob) mice. Initial in vitro experiments confirmed the potent insulinotropic properties of N‐AcGIP and (Val8)GLP‐1 in the clonal pancreatic BRIN BD11 cell line. Subchronic administration of N‐AcGIP, (Val8)GLP‐1 or combined peptide administration had no significant effects on the body weight, food intake and plasma insulin concentrations. However, all treatment groups had significantly (p < 0.05) decreased plasma glucose levels and improved glucose tolerance by day 14. The effectiveness of the peptide groups was similar, and glucose concentrations were substantially reduced following injection of insulin to assess insulin sensitivity compared to control. These results provide evidence for an improvement of glucose homeostasis following treatment with enzyme‐resistant GIP and GLP‐1 analogues. Copyright © 2007 European Peptide Society and John Wiley & Sons, Ltd.
Establishment and clinical application of enzyme immunoassays for determination of luteinizing hormone releasing hormone and metastin
Authors: Katagiri Fumihiko , Tomita Kenji , Oishi Shinya , Takeyama Masaharu , Fujii Nobutaka
Published: May 2007

Metastin, a 54‐residue peptide, was identified as the cognate ligand of human G‐protein‐coupled receptor GPR54. Since metastin is a gene product of the human metastasis suppressor gene ‘KiSS‐1’, early studies on metastin were focused on its activity as a tumor metastasis suppressor. Recently, there have been some reports that metastin is found in human plasma and is particularly abundant in the plasma of pregnant women. Dysfunction of the GPR54 receptor causes diseases that are characterized by an insufficient release of gonadotropin and lack or delay of pubertal maturation. This information strongly suggests that metastin is involved in the regulation of reproductive endocrine functions. In order to determine the plasma levels of metastin and luteinizing hormone releasing hormone (LHRH) in an isolated hypogonadotropic hypogonadism (IHH) patient, who received intermittent administrations of LHRH, we tried to establish a sensitive and specific enzyme immunoassay. The plasma LHRH levels of the patient were very high, while plasma metastin levels were at almost the same levels as circadian rhythms of healthy male humans. In the central nervous system, metastin stimulates the neuroendocrine reproductive axis. However, the effects of peripheral metastin are not known. Our result suggested that peripheral metastin had a genesis and activity different from central metastin. Copyright © 2007 European Peptide Society and John Wiley & Sons, Ltd.
Effects of dietary red clover on blood factors and cardiovascular fatty streak formation in hypercholesterolemic rabbits
Authors: Asgary S. , Moshtaghian J. , Naderi G. , Fatahi Z. , Hosseini M. , Dashti G. , Adibi S.
Published: May 2007

Phytoestrogens with a biological activity like estradiol are naturally found in many plants. This study was designed to investigate the effect of red clover, a phytoestrogen‐rich member of the legume family (Trifolium pratense) on the development of atherosclerosis in male hyperlipidemic rabbits. Twenty rabbits were semi‐randomly distributed into four groups of five each. Two groups received either normal diet or normal diet supplemented with red clover. Two other groups received similar diets to both of which 1% cholesterol was added. Dietary use of red clover (RC) in hyperlipidemic rabbits significantly decreased C‐reactive protein (CRP), triglyceride (TG), total cholesterol and LDL‐cholesterol (LDL‐C) whereas, HDL‐cholesterol (HDL‐C) was significantly increased in those animals (p < 0.05). Fatty streak formation was also significantly lower in aorta and left and right coronary arteries in the same animals due to use of dietary RC supplementation. These findings suggest that dietary RC may reduce cardiovascular risk factors. Copyright © 2007 John Wiley & Sons, Ltd.
Treating primary infertility due to pituitary atrophy with Chinese herbs: a case report
Authors: Zhou Jue , Qu Fan
Published: May 2007

In the report a patient who suffered from secondary amenorrhea for 6 years and primary infertility for 2 years due to pituitary atrophy was successfully cured with Chinese herbs. After orally administered Chinese herbs for 1 month, the patient menstruated once and became pregnant later. Copyright © 2007 John Wiley & Sons, Ltd.
Effects of propolis extract on sensitivity to chemotherapeutic agents in HeLa and resistant sublines
Authors: Takara Kohji , Fujita Megumi , Matsubara Mika , Minegaki Tetsuya , Kitada Noriaki , Ohnishi Noriaki , Yokoyama Teruyoshi
Published: May 2007

The effects of a propolis extract obtained by supercritical fluid extraction on sensitivity to chemotherapeutic agents were examined in HeLa cells and resistant sublines thereof. In addition, the actions of propolis and caffeic acid phenethyl ester (CAPE), a constituent of propolis, on the multidrug efflux transporter P‐glycoprotein/MDR1, were evaluated in paclitaxel‐resistant HeLa/TXL cells (MDR1‐overexpressing cells). In HeLa cells, the sensitivity to paclitaxel and doxorubicin, substrates of MDR1, was unchanged in the presence of propolis. In HeLa/TXL cells, propolis increased sensitivity to these MDR1 substrates. The accumulation of Rhodamine123, also a substrate for MDR1, by HeLa/TXL cells increased in the presence of 50 µg/mL, but not 10 µg/mL, of the extract. However, the growth inhibition of HeLa/TXL cells by paclitaxel was not changed by CAPE, although the accumulation of Rhodamine123 increased significantly in the presence of 100 µm, but not 1 nM or 1 µm, CAPE. Collectively, the extract was suggested to inhibit the function of MDR1 and to increase the sensitivity to MDR1 substrates in HeLa/TXL cells, effects likely to be caused by constituents other than CAPE. Copyright © 2007 John Wiley & Sons, Ltd.
Effect of acute administration of hydroalcohol extract of Ilex paraguariensis St Hilaire (Aquifoliaceae) in animal models of Parkinson's disease
Authors: Milioli E. M. , Cologni P. , Santos C. C. , Marcos T. D. , Yunes V. M. , Fernandes M. S. , Schoenfelder T. , Costa‐Campos L.
Published: May 2007

Ilex paraguariensis St Hilaire (Aquifoliaceae) is a plant widely cultivated in South America and with various reputed medicinal properties that can be attributed to phenolic constituents of the leaves: caffeine, theophylline and theobromine, besides the flavonoids, quercetin and rutin. This study examined the antiparkinsonian activity of the hydroalcohol extract of Ilex paraguariensis in models of protection against cerebral injury induced by MPTP and reversal of the catatonia induced by reserpine in mice. The hydroalcohol extract prevented MPTP‐induced hypolocomotion at doses of 250 and 500 mg/kg at the all time points observed and also prevented the reserpine‐induced catalepsy at the same doses. The extract potentiated the effect of apomorphine in preventing catatonia, suggesting a non‐dopaminergic activity, probably through antagonism of adenosine. In biochemical studies the hydroalcohol extract caused a significant decrease in the NO levels, exhibited a DPPH‐scavenging ability and was effective in preventing the oxidation of deoxyribose. The results obtained suggest that the hydroalcohol extract of Ilex paraguariensis may have an antiparkinsonian profile in animal models, probably through its antioxidant activity and antagonist action on adenosine A2A receptors. Copyright © 2007 John Wiley & Sons, Ltd.
A randomized, double blind, placebo‐controlled, prospective clinical study to demonstrate clinical efficacy of a fixed valerian hops extract combination (Ze 91019) in patients suffering from non‐organic sleep disorder
Authors: Koetter U. , Schrader E. , Käufeler R. , Brattström A.
Published: May 2007

Valerian and hops are traditionally used as sleep aids. Since the fixed extract combination (Ze 91019) as a whole is considered the active compound, the clinical efficacy must be demonstrated for this extract combination. The present clinical study aimed to demonstrate superiority of the fixed extract combination in comparison with placebo in patients suffering from non‐organic insomnia (ICD 10, F 51.0–51.2). Objective sleep parameters were registered by means of a transportable home recorder system (QUISI). The primary outcome was the reduction in sleep latency (SL2) which had to be prolonged at baseline (≥30 min) as an inclusion criteria. The treatment period lasted for 4 weeks with either placebo, single valerian extract (Ze 911) or the fixed valerian hops extract combination (Ze 91019). The amount of the single valerian extract was identical to that amount contained in the fixed extract combination, i.e. 500 mg valerian extract siccum. In the extract combination 120 mg hops extract siccum was added. Both the extracts were prepared with 45% methanol m/m with a drug–extract ratio of 5.3:1 (valerian) and 6.6:1 (hops), respectively. The fixed extract combination was significantly superior to the placebo in reducing the sleep latency whilst the single valerian extract failed to be superior to the placebo. The result underlined the plausibility for adding hops extract to the valerian extract. Copyright © 2007 John Wiley & Sons, Ltd.