bluuebunny/crossref_metadata_2025 huggingface dataset:
Outcome-based continuous quality improvement as a financial strategy for home health care agencies
Authors: Schlenker Robert E. , Shaughnessy Peter W. , Crisler Kathryn S.
Published: March 2007

Rapid growth in home health care has led to heightened attention by third-party payers and regulators. Increasingly home health agencies (HHAs) must demonstrate the value of their serv ices. A major concurrent trend within the industry and at the federal level is toward incorporat ing standardized outcome measures in the continuous quality improvement (CQI) programs in HHAs. We suggest that in addition to improving quality, outcome-based CQI can help a HHA demonstrate the value of its services, improve the cost-effectiveness of its care provision, and thereby strengthen its financial viability. Key words: continuous quality improvement, finan cial strategy, outcome measurement
Memory Management Issues in Sparse Multifrontal Methods On Multiprocessors
Authors: Amestoy Patrick R. , Duff lain S.
Published: March 2007

This article addresses the problems of memory man agement in a parallel sparse matrix factorization based on a multifrontal approach. We describe how we have adapted and modified the ideas of Duff and Reid used in a sequential symmetric multifrontal method to de sign an efficient memory management scheme for parallel sparse matrix factorization. With our solution, using the minimum size of the working area to run the multifrontal method on a multiprocessor, we can ex ploit only a part of the parallelism of the method. If we slightly increase the size of the working space, then most of the potential parallelism of the method can be exploited. We have designed a flexible memory man agement scheme which adapts well to a variation in the size of the working area and/or the number of pro cessors. General parallel applications can always be represented in terms of a computational graph, which is effectively the underlying structure of a parallel mul tifrontal method. Therefore, we believe that the tech niques presented here are useful when designing an efficient memory management scheme for a wider range of parallel applications.
Simulating Normal Rectangle Probabilities and Their Derivatives: Effects of Vectorization
Authors: Hajivassiliou Vassilis Argyrou
Published: March 2007

This paper studies the computationally difficult prob lem of evaluating the multiple integral representing the probability of a multivariate normal random vector, constrained to lie in a rectangular region. A leading case of such an integral is the negative orthant proba bility, implied by the multinomial probit model used in econometrics and biometrics. Classical parametric esti mation of this type of model requires repeated evalu ation of such probabilities and their derivatives, thus making such estimation computationally intractable. Monte Carlo simulators have been developed to ap proximate the orthant probability integral and its deriv atives that limit computation while possessing proper ties that facilitate their use in statistical inference. I dis cuss Gauss and Fortran implementations of 13 simulation algorithms and show that these differ greatly with respect to the degree of vectorization: in some cases vectorization achieves a speedup factor in excess of 10, while in others the gains are negligible. Judged in terms of simulation root-mean-squared-er ror for a given investment in computation time, I find that the importance sampling recursive triangulariza tion simulator GHK remains the best method for simu lating probabilities irrespective of vectorization; the crude Monte Carlo simulator CFS offers the greatest benefits from vectorization; and the Gibbs resampling algorithm GSS emerges as one of the preferred meth ods for simulating logarithmic derivatives, especially in the absence of vectorization.
Econometric Model Simulation On Parallel Computers
Authors: Gilli Manfred , Pauletto Giorgio
Published: March 2007

The solution of large and sparse models presents in many ways a suitable structure for implementation on parallel computers. However, efficient use of these computing devices requires that the code be specifi cally structured to exploit the particular type of parallel computer used. This article discusses the implementa tion of data parallel processing algorithms as well as performance results based on the solution of a macro- econometric model on a Connection Machine 2.
Interactive, Animated Visualization Environment for Three-Dimensional Fluid Flow
Authors: Lowther K. , Salem J.C. , Sethian J.A.
Published: March 2007

We describe an interactive, animated graphics environ ment that can be used to visualize the results of com putational fluid dynamics simulations. With this sys tem, the user can visualize flow past bodies or in chambers, using a variety of techniques borrowed from laboratory experiments, including dye injection, smoke visualization, and bubble wires. The environ ment provides the capability of three-dimensional rota tion of the flow under study, as well as placement of internal flow probes that can read location, velocity, and secondary quantities (such as vorticity and pres sure), which can be calculated from available data as the visualization unfolds. The system is implemented on a Connection Machine 2 attached to a framebuffer. As input, it accepts discretized data from a three- dimensional fluid flow calculation. Data should be provided on a three-dimensional grid at discrete time steps, and internal bodies and flow boundaries are de scribed using discrete panels. Input parameters are menu-driven, and images are updated at five frames per second. A prototype, second version of the system is implemented on a Connection Machine 5 using the Application Visualization System.
A Pvm Implementation of the Mchf Atomic Structure Package
Authors: Stathopoulos Andreas , Ynnerman Anders B. , Fischer Charlotte F.
Published: March 2007

The Multiconfiguration Hartree-Fock (MCHF) package is a suite of programs that provide the atomic data re quired by many science and engineering disciplines. Previous implementations of the MCHF on parallel computers provided means for meeting the ever- increasing computational demands posed by these calculations. However, the resulting codes had strict limitations on speed, problem size, and communication.

In this paper, a Parallel Virtual Machine (PVM) imple mentation of the MCHF is considered on a cluster of high-end workstations. Some of the limitations are overcome through the high utilization of resources (in cluding CPU, prime memory, and disk space). The de velopment of efficient routines for global operations and of a user-friendly interface exploits the special characteristics of PVM programming. Moreover, a re structuring of the methods provides new codes that do not bear the above limitations and that exhibit signifi cantly better speedups. Besides the algorithmic im provements, this paper presents a flexible code that can be used equally well on workstations and on the IBM SP2 multiprocessor to solve problems of one or der of magnitude larger than any previous attempts, and thus facilitates new research in various scientific fields.
Performance Modeling of Interactive, Immersive Virtual Environments for Finite Element Simulations
Authors: Taylor Valerie E. , Huang Milana , Canfield Thomas , Stevens Rick , Reed Daniel , Lamm Stephen
Published: March 2007

Interactive, immersive virtual environments allow ob servers to move freely about computer-generated three- dimensional objects to explore new environments. The effectiveness of these environments is dependent on the graphics used to model reality and the end-to-end lag time (i.e., the delay between a user's action and the display of the result of that action). In this paper, the authors focus on the latter issue, which has been found to be equally important as frame rate for interactive displays. In particu lar, the authors analyze the components of lag time result ing from executing a finite element simulation on a multi processor system located in Argonne, Illinois, connected via ATM to the interactive visualization display located in San Diego, California. The primary application involves the analysis of an automotive disk brake system that was demonstrated at the Supercomputing '95 conference as part of the Information Wide Area Year (I-WAY) project, which entailed the interconnection of various supercom puting centers via a high-bandwidth, limited-access ATM network. The results of this study indicate that the major components of the end-to-end lag are simulation, synchro nization, and rendering times; the use of the ATM network resulted in the network time constituting only a small fraction of the end-to-end lag time.
Early Experiences With Distributed Supercomputing On I-Way: First Principles Materials Science and Parallel Acoustic Wave Propagation
Authors: Geist George A. , Kohl James A. , Nicholson Donald M. C. , Papadopoulos Philip M. , Semeraro Bart D. , Shelton William A. , Stocks G. Malcolm , Yang Wang
Published: March 2007

The authors present experiences relating to two simula tions running on a dedicated network of supercomputers that are connected and scheduled with I-WAY. Each code uses PVM (parallel virtual machine) as the message- passing layer so that the heterogeneity of the computers becomes transparent. These computationally intensive codes require hundreds to thousands of processors to achieve acceptable performance. The I-WAY testbed pro vides access to the needed resources by allowing a re searcher to use a virtual I-WAY machine (VIM), which is a collection of supercomputing, visualization, and network resources from around the country. The authors slightly modified the PVM to operate within the I-WAY scheduling and authentication mechanisms and present the user with a familiar interface to run existing programs on this new testbed. New challenges are presented when attempting to write efficient codes for geographically distributed com puters. The applications presented here were successfully ported to the current I-WAY environment.
NAMD: a Parallel, Object-Oriented Molecular Dynamics Program
Authors: Nelson Mark T. , Humphrey William , Gursoy Attila , Dalke Andrew , Kalé Laxmikant V. , Skeel Robert D. , Schulten Klaus
Published: March 2007

NAMD is a molecular dynamics program designed for high performance simulations of large biomolecular systems on parallel computers. An object-oriented design imple mented using C++ facilitates the incorporation of new algorithms into the program. NAMD uses spatial decom position coupled with a multithreaded, message-driven design, which is shown to scale efficiently to multiple processors. Also, NAMD incorporates the distributed par allel multipole tree algorithm for full electrostatic force evaluation in O( N) time. NAMD can be connected via a communication system to a molecular graphics program in order to provide an interactive modeling tool for viewing and modifying a running simulation. The application of NAMD to a protein-water system of 32,867 atoms illus trates the performance of NAMD.
Loop Splitting for High Performance Computers
Authors: Ilin Andrew , Scott L. Ridgway
Published: March 2007

This paper discusses program transformations and algorithm modifications that reduce execution time of iterative methods for solv ing partial differential equations on high performance computers. Tech niques typically associated with par allel computers turn out to be essen tial to obtain optimal performance on current superscalar uniprocessors.
Parallel Implementation of the Yau and Lu Method for Eigenvalue Computation
Authors: Tisseur Françoise
Published: March 2007

In this paper, parallel extensions of a complete symmetric eigensolver, proposed by Yau and Lu in 1993, are pre sented. First, an overview of this invariant subspace decomposition method for dense symmetric matrices is given, followed by numerical results. Then, works are exposed in progress on distributed-memory implementa tion. The algorithm's heavy reliance on matrix-matrix mul tiplication, coupled with Fast Fourier Transform (FFT), should yield a highly parallelizable algorithm. Finally, performance results for the dominant computation kernel on the Intel Paragon are presented.
Solving Irregular Sparse Linear Systems On a Multicomputer Using the Cgnr Method
Authors: Manneback Pierre
Published: March 2007

The efficient solution of irregular sparse linear systems on a distributed-memory parallel computer is still a major challenge. Direct methods are concerned with unbalanced load processing or data distribution and difficulties pertain ing to reusing efficient sequential codes. Iterative methods of the Krylov family are well suited for parallel computing but can provide disappointing convergence for general sparse problems. Therefore, finding efficient parallel preconditioners is often required to obtain acceptable convergence rates. In this paper, we explore the use of a preconditioned conjugate gradient algorithm for the paral lel solution of irregular sparse nonsymmetric systems. A first step is the choice of a high-quality algorithm for matrix partitioning. For this purpose, we have selected the Metis package, developed by Karypis and Kumar of the Univer sity of Minnesota. A second step is the choice of the preconditioner. We have selected the Block-Jacobi preconditioner for its inherent parallelism and the local dense computation it generates. The iterative method itself is the standard conjugate gradient on the normal equations (known as CGNR). Experimental results are reported involving problems from the Harwell-Boeing col lection executed on the Intel Paragon, using the Aztec- distributed iterative library of the Sandia Laboratories.
Cumulvs: Providing Fault Toler. Ance, Visualization, and Steer Ing of Parallel Applications
Authors: Geist G.A. , Kohl James Arthur , Papadopoulos Philip M.
Published: March 2007

The use of visualization and computational steering can often assist scientists in analyzing large-scale scientific applications. Fault tolerance to failures is of great impor tance when running on a distributed system. However, the details of implementing these features are complex and tedious, leaving many scientists with inadequate develop ment tools. CUMULVS is a library that enables program mers to easily incorporate interactive visualization and computational steering into existing parallel programs. Built on the PVM virtual machine framework, CUMULVS is portable and interoperable with all the computer archi tectures that PVM works with—a growing list that now stands at about 60 architectures. The CUMULVS library is divided into two pieces: one for the application program and one for the possibly commercial, visualization, and steering front end. Together, these two libraries encom pass all the connection and data protocols needed to dynamically attach multiple, independent viewer front ends to a running parallel application. Viewer programs can also steer one or more user-defined parameters to "close the loop" for computational experiments and analy ses. CUMULVS allows the programmer to specify user- directed checkpoints for saving an important program state in case of failures and also provides a mechanism to migrate tasks across heterogeneous machine architec tures to achieve improved performance. Details of the CUMULVS design goals and compromises as well as future directions are given.
From a Direct Solver To a Parallel Iterative Solver in 3-d fOrming Simulation
Authors: Coupez Thierry , Marie Stéphane
Published: March 2007

The industrial simulation code FORGE3, devoted to three- dimensional forming applications, has been equipped with a robust iterative solver. Using an implicit approach, this code carries out the large deformations of viscoplastic incompressible materials with unilateral contact condi tions. It is based on a mixed-velocity/pressure finite ele ment method using tetrahedral unstructured meshes. Central to the Newton iterations dealing with the non linearities, a conjugate residual method with a diagonal or block diagonal preconditioning has been implemented. The convergence rate of the iterative solver is given. The advantage and performance of this iterative method are compared to the direct solution. The complete parallel version of the code is performed by using a single-program multiple-data programming model. The scalability of the parallel iterative solver is shown on real complex applica tions. Several results of parallel computing are given for both a cluster of workstations and for an IBM SP2 up to 34 processors.
I/O in Parallel Applications: the Weakest Link
Authors: Thakur Rajeev , Lusk Ewing , Gropp William
Published: March 2007

Parallel computers are increasingly being used to run large-scale applications that also have huge input/output (I/O) requirements. However, many applications obtain poor I/O performance on modem parallel machines. This two-part special issue of the Intemational Journal of High Performance Computing Applications contains papers that describe the I/O requirements and the techniques used to perform I/O in real parallel applications. The authors first explain how the I/O application program inter face (API) plays a critical role in enabling such applications to achieve high I/O performance. They describe how the commonly used UNIX I/O interface is inappropriate for parallel I/O and how an explicitly parallel API with support for collective I/O can help the underlying I/O hardware and software perform I/O efficiently. They then describe MPI- IO, a recently defined, standard, portable API specifically designed for high performance parallel I/O. They conclude with an overview of the papers in Part 1 and Part 2 of this special issue.
A Mysterious Journey
Authors: Greaves Chris
Published: March 2007

The title of this column indicates a means of getting in touch with ideas and people which other media cannot reach! A wide freedom of expression — both in content and in form — is offered to contributors. Please send your contributions to: MIKE PEDLER, Department of Management Studies, Sheffield City Polytechnic, Dyson House, Sheffield 1. Tel: 0742 738621.
4. Middle East
Authors: Minde K.
Published: March 2007

S. SKEA, J. G. DRAGUNS, and L. PHILLIPS compared psychopathological symptoms presented by Israeli children of Polish, German, Iraqi, and Yeminite extraction. They found significant differences between the groups studied in their sphere of symptoms according to national background.
8. North America
Authors: Jilek W.J.
Published: March 2007

Much interest has been shown of late in the psychiatric problems of members of American subcultures. The materials to be presented in this section are concerned with American Indians, Mexican-Americans, Japanese-Americans, and Chinese-Americans. J. H. SHORE et al. conducted a psychiatric epidemi ological study in a small Indian fishing village in the State of Washington. They conclude that poverty and cultural change combine to produce the increased psychiatric morbidity in this village. A parallel study carried out by this group led to the establishment of a community mental health consul tation program in the same village. P. E. TERMANSEN, a psychiatrist, and J. RYAN, an anthropologist, conducted a mental and physical health survey of British Columbia Indians and non-Indian controls. Their study was three- pronged : it included a survey of general practitioners, a study of hospital admissions (charts and interviews), and a community survey of an urban Salish Indian reserve. R. JESSOR and his multidisciplinary team, composed of two psychologists, an anthropologist, and a sociologist, attempted to establish a theory of deviant behavior through a sociopsychological methodology applied to expressions of alcohol abuse in three U.S. cultures (Anglo-American, Spanish-American, and American Indian). D. H. STOKER et al. compared Anglo-American and Mexican-American female patients undergoing psycho therapy and describes differences noted between the two groups. R. B. EDGERTON et al. explored the relative importance of folk psychotherapy— curanderismo—among Mexican-Americans in East Los Angeles. They found that curanderismo in East Los Angeles has lost its traditional, dramatic, cere monial quality and that nowadays few Mexican-Americans turn to curanderos for help. The next paper of this section deals with Japanese-Americans. G. M. MATSUMOTO et al. compared the magnitude of ethnic identification among three generations of Japanese-Americans in Honolulu, Hawaii, with a previous similar study carried out in Seattle, Washington. Their tool of in vestigation was the Ethnic Identity Questionnaire. Finally P. G. BOURNE, as part of a broader psychiatric study of the Chinese in San Francisco, reports on suicide among them.
6. South America and the Caribbean
Authors: Negrete J.
Published: March 2007

T. A. DE FUNDIA, J. G. DRAGUNS, and L. PHILLIPS compare American and Argentine inpatients of mental hospitals regarding coping styles. They find that a passive style of coping is resorted to by Argentines, whereas aggressive symptoms characterize Americans. Some methodological biases and short comings of their research are noted by the reviewer. The features of cannabis as a culture complex in India seem, according to V. RUBIN, to have diffused in Jamaica during the nineteenth century. On the basis of an intensive study of thirty users of cannabis in Jamaica, the author finds striking differences with regards to attitudes towards and use of cannabis between the lower and the middle classes.
Review : Clinical competency: the right assessment tools?
Authors: Buckingham Sylvia
Published: March 2007

Effective assessment of competency of student nurses in clinical practice is vital

Use of simulation rather than real life settings can be used to assess competency

Development of information technology and its use in teaching clinical skills offers opportunities for assessment

Clinical governance increases the need to scrutinise the assessment of practice

Ongoing assessment of clinical competency for qualified nurses is also important.
Review : A tripartite approach to assessing practice
Authors: Long Tony , Asbury Jill
Published: March 2007

■ Assessment of clinical practice is at least as important as assessment of theory.

■ To date the assessment of clinical competence at differing levels has been neglected.

■ When assessing clinical practice it is vital to utilise multiple sources of evidence.

■ A tripartite relationship of practitioner or student, supervising practitioner, and lecturer is a versatile arrangement for evaluating evidence of achievement.
Great expectations? Parental participation in care
Authors: Blower Kirsty , Morgan Elizabeth
Published: March 2007

■ A structured questionnaire was used to compare the views of 80 parents and nurses examining expectations of parental participation in care.

■ Nurses and parents shared many expectations. However, there were instances when parents expected a different and sometimes greater level of participation.

■ A lack of negotiation between parents and nurses with regard to expected roles resulted in parents often feeling unable to express their desired level of participation.

■ Both parties indicated that if parents received greater guidance and support, it would be possible for their expectations to be met more adequately.
Review : Higher Education: making an informed choice
Authors: Bramwell Rosalind Susan , Dixon Annie Mary
Published: March 2007

■ Potential students need to make informed choices when undertaking further study.

■ Potential students should access different sorts of information regarding the institution of their choice.

■ Potential students need to be aware of how service needs influence the choices available.

■ Potential students should have a clear idea of what they are aiming for.

■ Potential students should be aware of the differences between similar courses.
Review : Simple febrile convulsions: evidence for best practice
Authors: Hawksworth Dawn L
Published: March 2007

■ Febrile convulsions are common in early childhood and may be the first sign of an illness.

■ Witnessing the convulsion and experiencing the subsequent admission is extremely stressful for parents.

■ Children's nurses need to identify the evidence for best practice in the management of febrile convulsions.

■ Parent education is an essential component of the management of care.
Review : Head louse infection: a health promotion activity
Authors: Maynard Elisabeth
Published: March 2007

■ Head lice are the most common human ectoparasite

■ Although an infectious disease, louse infection rarely cause physical problems other than an itchy scalp

■ Social stigma surrounding infection induces feelings of shame, anger and embarrassment for families

■ Preventative health education and promotion via screening can effectively reduce the incidences of lice infection

■ The Mosaic Model of Treatment is recommended as the most up-to-date treatment regime, suitable for use on all children
Agricultural Growth and Welfare: A Study on Indian States
Authors: Sengupta Atanu , Bhattacharya Jadab chandra , Chattopadhyay Manabendu
Published: March 2007

An underdeveloped country like India is marked by the presence of a considerable degree of unevenness in the pattern of growth among various regions. However, till now, most of the studies failed to consider the welfare implications of such a differential growth pattern. This article attempts to analyze such welfare aspects of growth by using Kakwani's (1997) growth parameters. Based on the aggregated state-level data on area, production and yield on some major crops (viz., rice, wheat and foodgrains) in India, the study reveals considerable variations in state- wise growth rates. It is observed that there is a diminishing returns to scale in operation which slows down the growth rate of the leading states. However, the less-developed states have not been able to catch up adequately over time. The result is also supported by the periodization analysis as suggested by Kakwani (1997). The study concludes that the growth of agriculture over the last 50 years after Indian Independence has been highly unequal. The new policy changes have failed to bring about a shift in this pattern so as to enhance the economic well-being of the people.
Farmer's Behaviour in Rice Irrigation in Monsoon Asia: Facts and Fallacies
Authors: Perera Jayantha
Published: March 2007

Large-scale gravity-fed irrigation projects in Monsoon Asia have been for some years described in irrigation literature as 'anarchy-ridden', which threatens the sustainability of irrigation investment and lowers farmers' incomes. The literature attributed anarchy in the systems to farmers' opportunistic behaviour and corrup tion and inefficiency among irrigation officials. One major strategy suggested in irrigation literature to address this twin problem is to establish farmer organizations, which would mobilize farmers to participate collectively in irrigation management and also to check irrigation agency irregularities. This article examines the veracity of this model in a comparative context, by looking at five major irrigation systems in Thailand, Myanmar, Vietnam and Sri Lanka. Although the study found some evidence to support this model, it however overwhelmingly shows that irrigation agencies have often to deal more with inappropriate technology and faulty con structions, water scarcity and poor water distribution planning, than with farmers' opportunistic behaviour. In fact, farmers have developed their own methods of mitigating adverse impacts of shortages and poor deliveries of water, which could hardly be labelled as 'anarchic'.
Cold Crack - Low Temperature Flexibility
Authors: Polfus W.F.
Published: March 2007

A discussion of the factors which affect cold crack and low temperature flexibility - This article is concerned mainly with canvas products as defined by CPAI and will include coated fabrics used for tarpaulins but may, in some cases, overlap into other coated fabric areas. There will be discussion on testing methods for cold crack and index of stiffness as determined by means of a cantilever beam. The effect on cold crack by the major thermoplastics, plasticizer content, fillers, pigments, and processing will be discussed. All these factors have a bearing on cold crack and flex ibility at low temperatures.
When Everyone's Vulnerable
Authors: Howley Aimee
Published: March 2007

This case explores the volatile circumstances that arise when a novice leader confronts possible litigation resulting from the poor judgment of an insecure teacher and the instigation of an unwise coach. It also examines the way educators’ perceptions of different studentsespecially students of color and students from unconventional backgrounds influence their behavior toward those students. In addition, the case provides opportunities to consider the role that values and beliefs play in shaping apparently insignificant but nevertheless influential educational decisions. This case can be used in classes that consider personnel management, instructional leadership, and diversity issues.
Enhanced Enzymatic Reaction of Tyrosinase-immobilized Polyacrylamide–(γ-Cyclodextrin) Membrane Coated on a Platinum Disk Electrode in Acetonitrile
Authors: Nakamura Toshio , Ji Xueping , Endo Kazuyoshi , Takano Daisuke
Published: March 2007

A functionalized stable film, polyacrylamide–(γ-cyclodextrin) (PAA–γ-CD), synthesized from polyacrylamide (PAA) and γ-cyclodextrin (γ-CD), was used to immobilize enzyme. The membrane containing γ-CD provided an excellent environment for enzymatic kinetics between tyrosinase in the membrane and the substrates in acetonitrile.
SSPMO: A Scatter Tabu Search Procedure for Non-Linear Multiobjective Optimization
Authors: Molina Julian , Laguna Manuel , Martí Rafael , Caballero Rafael
Published: March 2007

We describe the development and testing of a metaheuristic procedure, based on the scatter-search methodology, for the problem of approximating the efficient frontier of nonlinear multiobjective optimization problems with continuous variables. Recent applications of scatter search have shown its merit as a global optimization technique for single-objective problems. However, the application of scatter search to multiobjective optimization problems has not been fully explored in the literature. We test the proposed procedure on a suite of problems that have been used extensively in multiobjective optimization. Additional tests are performed on instances that are an extension of those considered classic. The tests indicate that our adaptation of scatter search is a viable alternative for multiobjective optimization.
Algorithmic Analysis of the Maximum Queue Length in a Busy Period for the M/M/c Retrial Queue
Authors: Artalejo Jesus R. , Economou Antonis , Lopez-Herrero M. J.
Published: March 2007

This paper deals with the maximum number of customers in orbit (and in the system) during a busy period for the M/M/c retrial queue. Determining the distribution for the maximum number of customers in orbit is reduced to computation of certain absorption probabilities. By reducing to the single-server case we arrive at a closed analytic formula. For the multi-server case we develop an efficient algorithmic procedure for computation of this distribution by exploiting the special block-tridiagonal structure of the system. Numerical results illustrate the efficiency of the method and reveal interesting facts concerning the behavior of the M/M/c retrial queue.
Using Decomposition Techniques and Constraint Programming for Solving the Two-Dimensional Bin-Packing Problem
Authors: Pisinger David , Sigurd Mikkel
Published: March 2007

The two-dimensional bin-packing problem is the problem of orthogonally packing a given set of rectangles into a minimum number of two-dimensional rectangular bins. The problem is 𝒩𝒫-hard and very difficult to solve in practice as no good mixed integer programming (MIP) formulation has been found for the packing problem. We propose an algorithm based on the well-known Dantzig-Wolfe decomposition where the master problem deals with the production constraints on the rectangles while the subproblem deals with the packing of rectangles into a single bin. The latter problem is solved as a constraint-satisfaction problem (CSP), which makes it possible to formulate a number of additional constraints that may be difficult to formulate as MIP models. This includes guillotine-cutting requirements, relative positions, fixed positions and irregular bins. The CSP approach uses forward propagation to prune inferior arrangements of rectangles. Unsuccessful attempts to pack rectangles into a bin are brought back to the master model as valid inequalities. Hence, CSP is used not only to solve the pricing problem but also to generate valid inequalities in a branch-and-cut system. Using delayed column-generation, we obtain lower bounds of very good quality in reasonable time. In all instances considered, we obtain similar or better bounds than previously published. Several instances with up to n = 100 rectangles are solved to optimality through the developed branch-and-price-and-cut algorithm.
Multiple actions of the chemokine stromal cell-derived factor-1α on neuronal activity
Authors: Guyon Alice , Nahon Jean-Louis
Published: March 2007

The chemokine SDF-1α and its cognate receptor CXCR4 are expressed in several neuronal populations. This review focuses on our current knowledge about the actions of this chemokine on neuronal excitability, through CXCR4 or other yet unknown pathways. In various neuronal populations (CA1 neurons of the hippocampus, granular and Purkinje cells of the cerebellum, melanin-concentrating hormone neurons of the lateral hypothalamus, vasopressinergic neurons of the supraoptic and the paraventricular nucleus of the hypothalamus, and dopaminergic neurons of the substantia nigra), SDF-1α can modulate the activity of neurons by multiple regulatory pathways including and often combining: (i) modulation of voltage-dependent channels (sodium, potassium, and calcium), (ii) activation of the G-protein-activated inward rectifier potassium current, and (iii) increase in neurotransmitter release (gamma-amino butyric acid (GABA), glutamate, and dopamine), often through Ca-dependent mechanisms. The possible mechanisms underlying these effects and their consequences in terms of modulation of neuroendocrine systems and physiopathology are discussed.
CXC chemokine receptor 4 regulates neuronal migration and axonal pathfinding in the developing nervous system: implications for neuronal regeneration in the adult brain
Authors: Stumm Ralf , Höllt Volker
Published: March 2007

Chemotactic cytokines (chemokines) are small secreted proteins that control leukocyte trafficking in immune organs. Chemokines which are induced in the brain during conditions of inflammation play a role in the local immune response. Recently, it has been established in the rodent brain that distinct chemokines and chemokine receptors are constitutively expressed by neurons and that these chemokines modulate neuronal functions. The CXC motif chemokine stromal cell-derived factor-1 (SDF-1), CXCL12 together with its cognate receptor CXCR4 represents the best-characterized neuronal chemokine system. Transwell migration assays with neuronal precursors, pharmacological manipulation of CXCR4 signaling in embryonic brain explants, and histochemical studies of SDF-1- or CXCR4-deficient mouse embryos provide proof that SDF-1 directs neuronal migration and axonal pathfinding in the developing nervous system. In the adult brain, SDF-1 is thought to influence neurogenesis as well as recruitment of brain resident and non-resident circulating cells toward sites of lesion. The present review summarizes patterns and functions of the SDF-1/CXCR4 system in the rodent brain with a focus on the developing and adult cerebral cortex.
Long-term Effects of Pancreatic Transplant Function in Patients with Advanced Juvenile-onset Diabetes
Authors: Gliedman Marvin L , Tellis Vivian A , Soberman Robert , Rifkin Harold , Veith Frank J
Published: March 2007

Present methods of management of juvenile-onset diabetes mellitus do not prevent serious and debilitating complications affecting multiple organ systems. In an effort to reverse advanced forms of these complications, segmental transplantation of the pancreas has been performed on 10 patients, seven of whom simultaneously or subsequently received renal transplants. Long periods of normoglycemia (two to four and one-half years) were achieved in two patients who also maintained transplant kidney function. The course of these two patients is described to illustrate the possible value and limitations of the procedure. These patients had normal blood glucose levels, exhibited repeated normal intravenous glucose tolerance curves, and had repeated normal endogenous insulin levels. Their courses were characterized by (1) absence of problems related to pancreatic exocrine secretions into the bladder; (2) stable eye changes despite some episodes of hemorrhage from preëxisting retinopathy; (3) vascular complications, including stroke and gangrene of extremities necessitating amputation despite successful femoropopliteal bypass grafting; (4) peripheral neuropathy; and (5) repeated infections. Both patients succumbed to vascular complications.

Thus, pancreatic transplantation can maintain blood glucose and insulin at normal levels for extended periods of time. However, it does not reverse such complications as advanced retinopathy or atherosclerosis. Since the procedure may have value in preventing progression of these complications, it should be evaluated in patients with less advanced complications of diabetes.
Effect of Added Fiber on the Glucose and Metabolic Response to a Mixed Meal in Normal and Diabetic Subjects
Authors: Goulder T J , Alberti K G M M , Jenkins D A
Published: March 2007

10 g of guar was added to a test meal given to 11 subjects, six of whom had insulin-dependent diabetes, after an overnight fast. The addition of guar to the meal produced an overall decrease in the blood glucose concentrations after the meal in both normal and diabetic subjects. The insulin secretory response in the normal subjects was less when guar was included in the meal than when it was not. In normal subjects, but not in diabetic subjects, the addition of guar also resulted in a diminished response of lactate, pyruvate, and alanine to the test meal and a blunting of the fall in serum ketones. This is likely related to the fact that the same dose of insulin was given in the diabetic subjects with both test meals. Thus, in the normal circumstances, the diminished glycemic response to the guar-containing meal resulted in diminished insulin secretion, which was not the case with the diabetic subjects.
Prednisone Treatment in Newly Diagnosed Type I Diabetic Children: 1-Yr Follow-Up
Authors: Mistura Laila , Beccaria Luciano , Meschi Franco , D'arcais, Alberto Flores , Pellini Cristina , Puzzovio Maria , Chiumello Giuseppe
Published: March 2007

Thirty-one children suffering from type I diabetes mellitus were arranged at onset of the disease in two different groups. Group 1 was treated with oral prednisone (60 mg · m−2 · day−1 for 14 days, 30 and 15 mg · m−2 · day−1 for 7 days). Group 2 matched the control group. All patients were treated with continuous subcutaneous insulin infusion for the first 15 days of treatment, and then with two daily injections of a mixture of intermediate- and fast-acting insulin. All subjects were followed for 1 yr. Group 1 required more insulin than group 2 after 30 days (1.5 ± 0.3 vs. 0.6 + 0.2 U · kg−1 · day−1, P < .001) and after 60 days (0.8 ± 0.1 vs. 0.5 ± 0.06 U · kg−1 · day−1, P < .001). After 3 mo, both groups reached the lowest mean stable HbA1 level (8.4 ± 0.4 and 8.3 ± 0.4% group 1 and 2 respectively). Between the 2nd and 9th mo of follow-up, mean postbreakfast C-peptide concentration increased in both groups. The highest levels of fasting C-peptide were reached by group 1 after 90 days (0.77 ± 0.32 nM) and group 2 after 60 days (0.34 ± 0.09 nM). The largest partial remission (C-peptide 0.3 nM, insulin requirement <0.5 U · kg−1 · day−1 and no glycosuria) was observed in group 1 after 180 days (5 of 16 patients) and in group 2 after 60 days (5 of 15 patients). We found no significant difference between the two groups in fasting and postbreakfast C-peptide levels, stable HbA1, and remission during 1-yr follow-up. Short-term prednisone therapy in newly diagnosed type I diabetic children does not considerably modify the natural history of the disease during the 1st yr.
Comparison of Efficacy of Human and Porcine Insulin in Treatment of Diabetic Ketoacidosis
Authors: Storms Fred E M G , Lutterman Jos A , Laar Albert van't
Published: March 2007

The efficacy of semisynthetic human insulin (HI) and monocomponent porcine insulin (PI) in treatment of diabetic ketoacidosis (DKA) was compared in 10 (PI) and 11 (HI) patients in a double-blind randomized study. Insulin (8 U/h i.v.), fluid replacement (0.65% NaCl and 5% glucose), and KCl supplements were administered according to a fixed protocol. Glucose, potassium, sodium, creatinine, calcium, phosphate, and free-insulin concentrations were never significantly different during the study. At the start, mean ± SD of pH was 7.10 ± 0.14 in the HI group and 7.10 ± 0.12 in the PI group. The time to reach arbitrary values for pH, bicarbonate, base excess, and β-hydroxybutyrate was shorter during HI treatment, but the differences were not statistically significant. During HI treatment, the arbitrary value of 1.0 mM of acetoacetate was reached faster than during PI treatment (5.2 ± 2.6 and 8.4 ± 0.9 h, respectively; P < .05). The concentration of acetoacetate was significantly different between the two groups after 6 and 7 h of insulin treatment (6 h: HI 0.82 ± 0.50 mM and PI 2.19 ± 1.65 mM, P < .05; 7 h: HI 0.51 ± 0.40 mM and PI 1.74 ± 1.54 mM, P = .05). We conclude that recovery from DKA during treatment with HI might be slightly faster than during treatment with PI. If this difference is real, it does not seem clinically important.
Prolonged Fasting Hypoglycemia Due to Insulin Antibodies in Patient With Non-Insulin-Dependent Diabetes Mellitus: Effect of Insulin Withdrawal on Insulin-Antibody—Binding Kinetics
Authors: Van Haeften Timon W , Krom Bethany A , Gerich John E
Published: March 2007

Fasting hypoglycemia, which persisted for 3 days after insulin treatment was stopped,occurred in a patient with non-insulin-dependent diabetes mellitus who had inappropriate plasma free-insulin levels (18–25 μU/ml) and extremely high antibody-bound insulin (>20,000 μU/ml) but normal counterregulatory hormone secretion and plasma C-peptide levels. The amount of antibody-bound insulin decreased in a biphasic pattern over13 mo of observation with an initial half-life of 35 days and a more gradual decrease with a half-life of 160 days. The number of high-affinity antibody binding sites was virtually identical to the amount of antibody-bound insulin in the patient's plasma. We conclude that the patient's fasting hyperinsulinemia and hypoglycemia were due to release of antibody-bound insulin.
Diabetologists' Judgments of Diabetic Control: Reliability and Mathematical Simulation
Authors: Spevack Marika , Johnson Suzanne Bennett , Harkavy Jill M , Silverstein Janet , Shuster Jon , Rosenbloom Arlan , Malone John
Published: March 2007

In study 1, laboratory and supervised blood or urine test data from actual cases were used to develop patient profiles. Seven diabetologists from the same institution rated the diabetic control of 125 profiles on a four-point scale (1 = poor, 2 = fair, 3 = good, 4 = excellent). Six of the 7 diabetologists demonstrated adequate intra- and interrater reliability. Study 2 assessed the reliability of judgments of diabetic control made by diabetologists working in two different settings. There were 9 raters from institution 1 and8 from institution 2. The impact of the amount and type of information on judgment reliability was evaluated by developing two types of profiles. The test form contained only laboratory and supervised blood or urine test data similar to that utilized in study 1. The history form contained this information as well as other descriptive data typically available to diabetologists. The 17 diabetologists rated 125 anonymous profiles on each of twoseparate occasions ∼ 1 wk apart. On one occasion they rated profiles presented on the test form. On the other occasion they rated profiles presented on the history form. As in study 1, the diabetologist raters demonstrated adequate intra- and interrater reliability. Intrarater reliability was somewhat better when rating test form profiles compared with history form profiles. Reliability was not higher within than between institutions. Ananalysis of the relative contribution of different diabetes control indices to the diabetologists' judgments indicated that HbA1 influenced raters' judgmentsat both institutions more than any other single variable. However, raters utilized other information as well, particularly the urine test and fasting blood glucose results. Use of a cholesterol measure by institution 2 raters, but not by institution 1 raters, was theonly clearly discrepant use of test form data by the diabetologists working in two different settings. A mathematical prediction equation was developed that accurately simulated the diabetologists' judgments. The robustness of this equation was tested and demonstrated on a cross-validation sample of the cases utilized in study 1.
Effects of Continuous Subcutaneous Insulin Infusion Versus Multiple Injections on Insulin Receptors in Insulin-Dependent Diabetics
Authors: Lecavalier L , Havrankova J , Hamet P , Chiasson J -L
Published: March 2007

We compared continuous subcutaneous insulin infusion (CSII) versus multiple injections (MI) in the treatment of insulin-dependent diabetes mellitus (IDDM) to assess the effect of glucose control on monocyte insulin receptors. Each IDDM patient (n = 8) was treated for 2 mo by MI (HS Ultralente and AC boluses of regular insulin) and for 2 mo by CSII in a randomized fashion. Prestudy preprandial/ postprandial blood glucose levels were 199 ± 33/261 ± 28 mg/dl and improved to 124 ± 12/156 ± 13 mg/dl during MI and to 115 ± 11/151 ± 11 mg/dl during CSII. Glycosylated hemoglobin before the study was 10.1 ± 0 . 5% and decreased to 8.8 ± 0.4 and 8.3 ± 0.3% during MI and CSII, respectively. The specific 125I-labeled insulin binding to circulating monocytes in a group of nonobese controls (n = 17) was 4.6 ± 0.2%. In our poorly controlled diabetics during conventional therapy, the 125Iinsulin binding was decreased to 3.7 ± 0.3 (P < .025). This was not significantly affected by MI despite good glucose control (4–0 ± 0.3%). With CSII, however, good glucose control was associated with normalization of 125I-insulin binding to monocytes (4.7 ± 0.27%). The affinity of the insulin receptors was normal before the study and was not affected by either MI or CSII. In conclusion, these observations demonstrate that in IDDM, intensive therapy by MI and CSII resulted in similar good glucose control, but only CSII resulted in normalization of insulin receptors on circulating monocytes.
Stable Insulin for Implantable Delivery Systems: In Vitro Studies With Different Containers and Solvents
Authors: Selam Jean-Louis , Zirinis Phedon , Mellet Marc , Mirouze Jacques
Published: March 2007

The stability of a new insulin formulation (lyophilized U100 insulin, Organon) was investigated in vitro in conditions reproducing those of in vivo implanted devices, i.e., constant horizontal agitation at 37°C for 4 wk in various containers and 8 wk in different solvents. Physical stability was assessed by ultraviolet absorption, chemical stability by HPLC, and biological stability by hypoglycemia tests in mice. Insulin precipitated in glass vials but remained clear and active in polyethylene reservoirs and after passage through catheter and pumps in motion, although only 83–90% of insulin was delivered chemically intact. In acidic solvent, insulin showed a major gradual transformation into deamidized derivatives (up to 78% after 8 wk), although still fully active and clear, as expected from previously published excellent in vivo results with acidic insulins. Heparin addition to neutral insulin solution (500 IU/ml) did not alter the properties of the two compounds and might thus be tried to prevent in vivo catheter obstruction due to fibrin deposition.