bluuebunny/crossref_metadata_2025 huggingface dataset:
A Branch and Bound Algorithm for a Transportation Type Problem with Piecewise Linear Convex Objective Function
Authors: Seshan C. R. , Achary K. K.
Published: June 2007

A branch and bound type algorithm is presented in this paper to the problem of finding a transportation schedule which minimises the total transportation cost, where the transportation cost over each route is assumed to be a piecewice linear continuous convex function with increasing slopes. The algorithm is an extension of the work done by Balachandran and Perry, in which the transportation cost over each route is assumed to beapiecewise linear discontinuous function with decreasing slopes. A numerical example is solved illustrating the algorithm.
Topologische Matrizen in den Gleichungen diskreter, ebener, dehnsteifer Schwinger
Authors: Schade D.
Published: June 2007

Beim automatisierten Aufstellen von Schwingungsgleichungen in vier verschiedenen Einflußzahlen muß der topologische Zusammenhang des Netzes des Schwingers beschrieben werden. In die Gleichungen mit Krafteinflußzahlen (Weggrößenverfahren) und mit Dehnungseinflußzahlen gehen Knotenmatrizen ein. Die Verschiebungseinflußzahlen (Kraftgrößenverfahren) enthalten Baum‐ und Maschenmatrizen. Die Gleichungen mit Schnittkrafteinflußzahlen sind Summengleichungen und lassen sich nur im Sonderfall mit Baum‐ und Maschenmatrix deuten.
Indentation of an Elastic Half‐Space by a Concave Rigid Punch
Authors: Shibuya Toshikazu
Published: June 2007

In this paper, the author analyzes exactly the stress state of an elastic half‐space indented by an axisymmetric concave rigid punch when the indented load is small and the contact area is an annulus. Numerical examples are presented for parabolic and conical concave punches.
Swirling Flow in a Straight Circular Pipe
Authors: Singh M. P. , Sinha P. C. , Aggarwal M.
Published: June 2007

In this paper the laminar axisymmetric swirling flow of an incompressible viscous fluid from the entry to the fully developed downstream region in a straight circular pipe of uniform cross‐section has been studied. The swirl has been prescribed at the entry, along with the longitudinal flow. The development of the flow has been divided into three regions and the analysis is based on the method of matched asymptotic expansions.
Zur numerischen Behandlung grenzflächendynamischer Probleme mittels Projektions‐Iterationsverfahren
Authors: Wilke H.
Published: June 2007

Das Problem der Marangoni‐Instabilität führt auf eine nichtlineare Anfangs‐Randwertaufgabe. Ein Teilproblem für die Strömungsgeschwindigkeiten wird mit Hilfe eines Projektions‐Iterationsverfahrens numerisch gelöst. Ein Vergleich der benötigten Rechenzeiten zeigt gegenüber dem Differenzenverfahren ganz erstaunliche Vorteile der neuen numerischen Methode, so daß ihre Anwendung auf kompliziertere Probleme dieser Art sinnvoll erscheint.
Notwendige Optimalitätsbedingungen für Prozesse mit zeitvariablen Integralgleichungen in Banach‐Räumen
Authors: Schmidt W. H.
Published: June 2007

Mit Hilfe eines abstrakten Modells von L. Bittner werden für Prozesse, die in Banach‐Räumen durch Volterrasche oder Fredholmsche Integralgleichungen beschrieben werden, notwendige Optimalitätsbedingungen hergeleitet. Berücksichtigt wird eine Parameteroptimierung. Um Maximumprinzipien zu formulieren, nutzen wir die quellenmäßige Darstellung der Lösung einer Integralgleichung aus. Erörtert werden Existenz und Eigenschaften einer Resolvente für Integralgleichungen in Banach‐Räumen.
Schwingungen nichtmischbarer Flüssigkeiten im rotierenden Kreiszylinder
Authors: Bauer H. F.
Published: June 2007

Zur Auslegung eines Nutationsdämpfers für einen drallstabilisierten Satelliten muß das Verhalten eines Flüssigkeitssystems, bestehend aus zwei inkompressiblen, reibungsfreien und nichtmischbaren Flüssigkeiten in einem unendlich langen um seine Längsachse rotierenden Kreiszylinder untersucht werden. Dabei werden für den vollkommen gefüllten wie auch den teilweise gefüllten Behälter die natürlichen Frequenzen und die Flüssigkeitskräfte, Oberflächen‐ und Trennflächenauslenkung für Translations‐ und Rotationsanregung bestimmt.
MHD Flow in Finned Conducting Ducts
Authors: Ariel P. D. , Aggarwala B. D.
Published: June 2007

In the present paper investigation is made of magnetohydrodynamic flow of electrically conducting fluid through conducting rectangular ducts with internal fins from the walls which are perpendicular to the magnetic field. An analytical treatment is given to the solution which reduces to the solution of a Fredholm integral equation of second kind. Numerical results are provided for pressure drop parameter for varying fin‐length and Hartmann number and for different aspect ratios of the duct. It is found that the pressure drop parameter increases with an increase in either the fin‐length or the Hartmann number.
On Stokes Flow between Parallel Plates with Stationary Random Surface Roughness
Authors: Phan‐Thien N.
Published: June 2007

The problems of Stokes flow of an incompressible Newtonian fluid between corrugated plates are considered. The corrugations are of small amplitude ϵ and are represented by stationary random functions. An exact solution (up to O(ϵ2)) is developed leading to an expression for the pressure drop enhancement as a function of the statistics of the corrugations. Simplifications of this expression in the case of sinuisoidal and slowly‐varying corrugations are discussed.
Precise Analysis of Elastic‐Plastic Deformation of Thin‐Walled Cylindrical Shell with Clamped Ends under Internal Pressure
Authors: Ohashi Y. , Okouchi T.
Published: June 2007

Elastic‐plastic deformation of a thin‐walled cylindrical shell with clamped ends under internal pressure is analyzed using Hencky's theory together with Mises' yield criterion.
Profit Optimization in A Two‐Unit Maintained Standby Redundant System
Authors: Kumar A. , Lal R.
Published: June 2007

The paper deals with a 2‐unit cold standby redundant system with exponential failure‐time and general repair‐time distributions. Profit equations for the system have been developed under the most generalized cost structure in which the earning rate of the system in a state depends upon three parameters–‐present state, future state of visit and time at which the earning rate is measured. Laplace transforms of the profit that the system will earn in a given time when the discounting rate is exponential, are obtained. Limiting behaviour of the profit has also been discussed. Further, profit has been suggested as the measure of system's effectiveness. When different alternatives are available to a decision maker in each state to operate the system, an optimization problem to determine an optimal operating policy for the system which maximizes long term profit has been formulated. Howard's policy iteration method is used to develop an algorithm to determine an optimal policy for the system.
Über eine Kombinationsresonanz im Dreikörperproblem
Authors: Mettler E.
Published: June 2007

Die vorliegende Arbeit befaßt sich mit der engen Verwandtschaft zwischen gewissen Teilen der Himmelsmechanik und der Schwingungslehre. Sie zeigt, daß die seit fast zwei Jahrhunderten bekannten säkularen Störungen im planetaren Dreikörperproblem eine Kombinationsresonanz mit Differenzfrequenz im Sinne der modernen Schwingungslehre darstellen.
Ein Variationskonzept zur Reduktion statischer Stabilitätsprobleme
Authors: Ruge P.
Published: June 2007

Im Rahmen der Näherungsberechnung von statischen Stabilitätslasten λ Für kontinuierliche Systeme wird gezeigt, wie die Ordnung der finiten Übersetzung Ax = λBx reduziert werden kann. Die Methode beruht auf der Einführung von Versatzmomenten infolge der Spannungen im Grundzustand als unabhängiger Zustandsgröße neben der Durchsenkung. Dieses Variationskonzept erlaubt eine exakte statische Kondensation durch Elimination der Weggrößenparameter.
Application of Invariant Variational Principles to the Optimal Design of a Column
Authors: Komkov V.
Published: June 2007

Using Noether's technique we derive some invariants associated with the problems of optimization of design. While specifically a beam design problem is discussed here, the technique can be generalized in an obvious manner to thin plate, or shell problems. The specific problem discussed in this paper concerns the optimization of a column. Some invariants derived here as examples of the technique can be used to point out the basic difficulties discovered by much harder arguments in many recent papers. In particular, our method points out the existence of singularities which are associated with an optimal column design even in the absence of multiple eigenvalues in the Euler's eigenvalue problem, which corresponds to the buckling phenomenon.
On the Fibre Pull‐out Problem
Authors: Phan‐Thien N. , Goh C. J.
Published: June 2007

In this paper, the force required to pull out a long, slender fibre embedded in a semi‐infinite elastic matrix by a distance W is derived. Assuming that the fibre is slender and that there is no slip at the fibre‐matrix interface, it is shown that the nature of the inclusion depends on the parameter \documentclass{article}\pagestyle{empty}\begin{document}$ \frac{{E^* }}{E}\left({\frac{R}{l}} \right)^2 \,\ln \,\left({\frac{{2l}}{R}} \right) $\end{document}, where E, E* are the Young's moduli of the matrix and the fibre respectively. R is a typical radius of the fibre and l its length. When this parameter is large, the fibre is effectively rigid and the load transfer occurs over the entire length of the fibre. If this parameter is very much less than unity, then the inclusion is elastic in nature and the load transfer occurs in a finite neighbourhood of the embedded end of the fibre which is near the free surface of the semi‐infinite matrix.
An Average Theory for the Dynamic Behavior of a Laminated Elastic‐Viscoplastic Work‐Hardening Medium
Authors: Aboudi J. , Benveniste Y.
Published: June 2007

An average theory which models the dynamic behavior of a bilaminated medium under specific types of loading, made of elastic viscoplastic work‐hardening materials is developed. Each constituent is represented by a unified theory of elastoviscoplasticity including work‐hardening, which requires neither a yield criterion nor loading or unloading conditions. The resulting effective theory appears in the form of a system of nonlinear differential equations for the avergage stresses, displacement and plastic work. The theory is applied to construct the effective stress‐strain curves of the laminated medium in which the transition from the elastic to the plastic domain can be determined. The theory is also applied to obtain the dynamic response of a laminated slab subjected to velocity or stress input.
Schätzung von Diskretisierungsfehlern bei der Lösung von Gleichungen in Banach‐Räumen
Authors: Lippold G.
Published: June 2007

In einer früheren Arbeit wurde eine Begründung der Schätzung von Diskretisierungsfehlern auf der Basis des Defektes in genaueren Gleichungen entwickelt, die sich ausschließlich am Stabilitätsbegriff für diskrete Abbildungsfolgen orientiert. Dieser Zugang wird hier so erweitert, daß er Aussagen zur Konsistenzordnung gestattet, die sonst über asymptotische Entwicklungen hergeleitet werden. Am Beispiel von Zweipunkt‐Randwertaufgaben für Systeme gewöhnlicher Differentialgleichungen wird die Tragfähigkeit der Ergebnisse demonstriert.
Optimalitätsbedingungen für Prozesse in Evolutionsgleichungen 1. Ordnung
Authors: Kampowsky W.
Published: June 2007

Die Arbeit beschäftigt sich mit Problemen optimaler Steuerung, die durch nichtlineare Evolutionsgleichungen 1. Ordnung mit Anfangs‐ oder speziellen Randbedingungen beschrieben werden. Mit Hilfe eines abstrakten Modells von L. Bittner werden notwendige Optimalitätsbedingungen hergeleitet, die in einem Spezialfall auch hinreichend sind.
On the Theory of Diffusion Processes in Viscoelastic Media
Authors: Gröger K. , Hünlich R.
Published: June 2007

The paper deals with initial value problems describing diffusion processes in viscoelastic media. By means of the theory of maximal monotone operators in Hilbert spaces it is shown that these problems are uniquely solvable. Moreover, the convergence of an approximation method is proved.
Coulomb Friction in Two‐Dimensional Rigid Body Systems
Authors: Lötstedt P.
Published: June 2007

Die Lösungen des Coulombschen Reibungsproblems für starre Körper in zwei Dimensionen werden analysiert. Das bestimmende System von gewöhnlichen Differentialgleichungen und Ungleichungen wird aufgestellt. Beispiele werden vorgelegt, die einige ungewünschte Eigenschaften dieses speziellen Reibungsgesetzes nachweisen. Hinreichende Bedingungen für Existenz und Eindeutigkeit werden mit Hilfe der Theorie der linearen Komplementarität hergeleitet.
Nicht‐lineare Schwingungen mit fast‐periodischer Parametererregung
Authors: Weidenhammer F.
Published: June 2007

Bekanntlich kann auch bei fast‐periodischer Parametererregung die Ruhelage für gewisse Frequenzen instabil werden. Die ersatzweise eintretenden nicht‐linearen Schwingungen werden näherungsweise für einige dieser Frequenzen berechnet.
On the Torsion of Elastic Cylindrical Bars
Authors: Bassali W. A. , Obaid S. A.
Published: June 2007

Certain trigonometric formulae and combinatorial identities are used to derive exact and closed expressions for the stress functions, torsional rigidities and peripheral shearing stresses of certain isotropic cylinders under torsion. The cross sections are bounded by the closed curves \documentclass{article}\pagestyle{empty}\begin{document}$ r = a\left| {\sin \frac{\theta }{n}} \right|^n \left({ - \pi < \theta \mathbin{\lower.3ex\hbox{$\buildrel<\over {\smash{\scriptstyle=}\vphantom{_x}}$}} \pi } \right) $\end{document} where n is a positive integer (n > 1). Complex variable methods are applied to obtain the complex torsion functions, torsional rigidities and shearing stresses when the sections are bounded by the contours \documentclass{article}\pagestyle{empty}\begin{document}$ r = a\cos ^n \frac{\theta }{n}\left({ - \frac{{n\pi }}{2} < \theta \mathbin{\lower.3ex\hbox{$\buildrel<\over {\smash{\scriptstyle=}\vphantom{_x}}$}} \frac{{n\pi }}{2}} \right) $\end{document}, where n is a positive number (0 < n ≦ 2). Numerical results are presented in the form of tables and graphs illustrating the variation of torsional rigidities and the distribution of tangential shearing stresses along the edges of the cross sections. The cardioid and lemniscate of Bernoulli are included as special cases.
Putative spermine synthases from Thalassiosira pseudonana and Arabidopsis thaliana synthesize thermospermine rather than spermine
Authors: Knott Jürgen M. , Römer Piero , Sumper Manfred
Published: June 2007

Polyamines are involved in many fundamental cellular processes. Common polyamines are putrescine, spermidine and spermine. Spermine is synthesized by transfer of an aminopropyl residue derived from decarboxylated S‐adenosylmethionine to spermidine. Thermospermine is an isomer of spermine and assumed to be synthesized by an analogous mechanism. However, none of the recently described spermine synthases was investigated for their possible activity as thermospermine synthases. In this work, putative spermine synthases from the diatom Thalassiosira pseudonana and from Arabidopsis thaliana could be identified as thermospermine synthases. These findings may explain the previous result that two putative spermine synthase genes in Arabidopsis produce completely different phenotypes in knock‐out experiments. Likely, part of putative spermine synthases identifiable by sequence comparisons represents in fact thermospermine synthases.
Re-envisioning the structure of last glacial vegetation in New Zealand using beetle fossils
Authors: Burge Philip I. , Shulmeister James
Published: June 2007

A series of 18 fossil beetle assemblages are used to reconstruct the paleoenvironment of the northwest West Coast, New Zealand, over the period of the last interstadial–stadial transition (ca. 37,000–21,300 cal yr BP). The samples were recovered from an in-filled hollow within a dune field ca. 9 km south west of Westport (41°47′S, 171°30′E). This fossil beetle reconstruction is compared to an existing palynological reconstruction from the same site. The beetle assemblages indicate an environment of marshy shrubland interspersed with closed canopy coastal vegetation prior to glacial onset, and a mosaic of closed canopy patches and open tussock grassland during full glacial conditions. These interpretations, contrast with the palynologically based interpretation which indicates subalpine shrubland prior to glacial onset and widespread grassland with little woody vegetation during the period of maximum glacial cooling. This study is consistent with other non-pollen studies in New Zealand and indicates that the palynological interpretation of the paleoenvironment of the Westport region downplays the importance of closed canopy vegetation in the area during the transition from interstadial to full glacial (stadial) conditions. It challenges the interpretation of open vegetation at low elevations during glacial periods from pollen studies.
Radiological anatomy of the anterior ethmoidal artery for functional endoscopic sinus surgery
Authors: McDonald S E , Robinson P J , Nunez D A
Published: June 2007

Aim:

This study investigated the extent to which the anterior ethmoidal artery and anterior ethmoidal foramen could be reliably identified on routine coronal sinus computed tomography scans. Where they could be identified, the relationship of these structures with the vertical height of the skull base, and their distance from an anterior landmark, were measured.

Methods:

Fifty consecutive coronal sinus computed tomography scans were viewed independently by two observers. Scans were reviewed when the observers' opinions differed.

Results:

Inter-observer concordance was high. The anterior ethmoidal foramen was visualised in 95 per cent of cases bilaterally and in the remaining 5 per cent unilaterally. The anterior ethmoidal artery was visualised in 33 per cent of scans. The anterior ethmoidal foramen was at skull base level in 72 per cent of sides studied, and below it in the remainder. The distance from the lacrimal crest to the anterior ethmoidal foramen was 22.4 mm (mean; standard deviation 3.7).

Conclusion:

The anterior ethmoidal foramen is a reliable landmark on coronal computed tomography scans of the paranasal sinuses. From this, the position of the anterior ethmoidal artery can be inferred.
Cervical extraskeletal Ewing's sarcoma: case report demonstrating radiological features and management
Authors: Ali S , MacKenzie K , Reid R , O'Neill G , Ganly I
Published: June 2007

Background:

Extraskeletal Ewing's sarcoma is a rare tumour of mesenchymal origin, which is histologically similar to primary osseous Ewing's sarcoma. The majority of cases have been reported in the lower limb and paravertebral region, with a few cases reported in the neck.

Methods:

We report a patient with extraskeletal Ewing's sarcoma presenting with a right-sided neck mass, vocal fold palsy and T1 nerve root involvement. The detection of characteristic features on computed tomography and magnetic resonance imaging scans, in conjunction with histological analysis, was required to make the diagnosis.

Results:

Radiological imaging demonstrated that the tumour was infiltrating through the neural exit foramina of the lower cervical nerve roots, with encasement of the vertebral artery. The patient was managed with combination chemotherapy for systemic control and irradiation for local control.

Conclusion:

Extraskeletal Ewing's sarcoma has a propensity to occur in a paravertebral location, being found rarely in the cervical region, and has a predilection to infiltrate through neural exit formina. Computed tomography and magnetic resonance imaging are helpful in the diagnosis of this rare tumour.
The Antarctic Committee for Environmental Protection: past, present, and future
Authors: Sánchez Rodolfo Andrés , McIvor Ewan
Published: June 2007

The Committee for Environmental Protection (CEP) was established under the Protocol on Environmental Protection to the Antarctic Treaty to advise the Antarctic Treaty Consultative Meeting (ATCM) on matters relating to protection of the Antarctic environment. After almost a decade of work, the committee has consolidated itself as a highly relevant and important component of the Antarctic Treaty system. Through a detailed analysis of meeting reports, as well as first-hand information and experience, this study describes the activities of the CEP during its first nine years of operation, provides likely explanations for some trends observed and proposes future scenarios by highlighting major challenges and opportunities. In particular, the instigation of strategic planning shows potential for launching a new era of CEP activities focused on the environmental issues requiring the greatest attention. This overview will assist readers to understand the role of the CEP as the main environmental advisor to the ATCM, and the reasons for the Antarctic Treaty parties to support the Committee's work to foster a spirit of cooperation as a prerequisite for continuing protection of the Antarctic environment.
Lönnberg House, Bird Island, South Georgia, 1963–2005
Authors: Tickell W.L.N.
Published: June 2007

This note describes the history of Lönnberg House, for 42 years an important building on Bird Island, South Georgia.
Health and Quality of Life Among Older People in Rural England: Exploring the Impact and Efficacy of Policy
Authors: MILNE ALISOUN , HATZIDIMITRIADOU ELENI , WISEMAN JANET
Published: June 2007

There is increasing evidence that characteristics of place influence health and that the dimensions of rurality interlock with the process of ageing to produce a number of distinctive patterns. For the rising number of older people living in rural England, it is clear that, overall, the countryside promotes the health and wellbeing of the newly retired, fitter cohort who have access to financial and community resources. However, it carries a number of risks for elders who are frail, deprived or isolated; inequalities combine to undermine health and deepen exclusion. The efficacy of policy in taking account of the needs of rural elders is uneven. Analysis of the three most pivotal policy arenas – rurality, ageing and health, and community development – suggests that while some initiatives do promote quality of life, significant limitations remain. Further, the overarching policy response is incoherent and fragmented. Key deficits relate to resource allocation, limited recognition of rural disadvantage, and minimal incorporation of the perspectives of rural elders. That the majority of policy is rurally blind is a fundamental challenge; for rural elders to benefit from policy investment, a systemic shift is required in the mechanisms that steer its development, funding and implementation.
Islamic terms in contemporary English
Authors: Bin Mohamed Ali Haja Mohideen
Published: June 2007

Some observations on what words associated with Islam are in, and what might yet go into, current ELT dictionaries. Muslims constitute a vast number of speakers of English as a Second Language (ESL) and a Foreign Language (EFL). As a consequence, many expressions associated with Islam have been introduced into contemporary English and its dictionaries – both general and ESL/EFL. The present paper focuses on three particular works: the Longman Dictionary of Contemporary English (LDOCE, 2003), the Macmillan English Dictionary (MED, 2002) and The New Oxford Dictionary of English (NODE, 1998), in order to discuss how Islamic terms are being used. It was found that few phrases or sentences are provided to illustrate such terms – even those in common use among English-speaking Muslims. The present paper therefore (1) suggests sample sentences for these terms, so that users of such dictionaries can set them in context, and (2) offers a list of common Islamic words for possible inclusion in future editions.
I'm the illest fucka
Authors: Shinhee Lee Jamie
Published: June 2007

An analysis of African American English in South Korean hip hop. English is rarely used in face-to-face terms in South Korea, but the use of English in commerce and entertainment is not such a rarity. The presence of English expressions in advertising and pop lyrics is no longer considered extraordinary. Lee (2006) reports that 83.75% of 720 South Korean TV commercials use some type of English, and only 16.25% of advertisements rely exclusively on Korean. Pop music is another discourse space in which English is fairly frequently used, occurring in more than 50% of pop song titles. A detailed analysis of the frequency of English in South Korean pop music (SK-pop) is reproduced.
Activation, Retirement Planning and Restraining the ‘Third Age’
Authors: Mann Kirk
Published: June 2007

This paper considers activation policies in relation to older workers in a number of OECD countries. It explores four interpretations of ‘activation’ in respect of pension planning and retirement policies. However, activation policies need to be carefully evaluated. Labour market demands and a political language that stresses the ‘pension crisis’ and the ‘dependency ratio’ have to be considered in relation to established rights. Thus whilst governments may seek to promote a model of welfare based on the ‘consumer citizen’, in which retirement choices are made by reflexive individuals, the constraints on choice need to be highlighted. These constraints are likely to be unevenly distributed with some social groups experiencing longer working lives, less choice, with more compulsion and with conditions attached to any pension rights they may claim.
‘Work First’ and Immigrants in Toronto
Authors: Mitchell Andrew , Lightman Ernie , Herd Dean
Published: June 2007

This paper examines the experiences of immigrants in Toronto as they pass through, and leave, Ontario Works (OW), a ‘Work First’ approach to social assistance that prioritizes rapid labour force attachment. We examine the Ontario Works activities of immigrants, compared to native born Canadians, and their respective post-OW job characteristics. We find that immigrants experience a significant relative wage disadvantage after participation, and substantially less wage growth when moving to the second post-welfare job. We conclude that Ontario Works, like most ‘work first’ employment programs, is ill-suited to addressing earnings disadvantage among immigrants. We suggest that programs ‘beyond work first’, though not targeted specifically towards immigrants, might nevertheless offer more assistance. The recurring wage disadvantage, however, would remain unaddressed and might require more direct intervention.
How Age and Disability Affect Long-Term Care Expenditures in the United States
Authors: Stearns Sally C. , Norton Edward C. , Yang Zhou
Published: June 2007

The ageing of the population and increasing longevity result in predictions of sizeable increases in long-term care expenditures. Other analyses have shown significant decreases in disability prevalence among older people in the US. This study provides an empirical quantification of the net result of these two forces (increased expenditures due to ageing versus potential expenditure reductions due to reduced disability) using the Medicare Current Beneficiary Survey. The analyses show that the implications of ageing and increasing longevity for long-term care expenditures are modest relative to the effects of future increases or decreases in functional abilities of older people.
The Costs of What? Measuring Services and Quality of Care
Authors: Netten Ann , Forder Julien
Published: June 2007

If we are to be able to reflect the cost implications of changes in the nature, quality and productivity of long-term care interventions in future projections, we need an approach to measurement that reflects the value and quality of care. This paper describes a theoretically based but pragmatic approach to identifying the welfare gain from government expenditure on social care and illustrates an application in projecting the costs of long-term care used in the Wanless review of future needs of social care for older people in England.
Rationale, Design and Sustainability of Long-Term Care Insurance in Japan – In Retrospect
Authors: Ikegami Naoki
Published: June 2007

When Japan introduced a new public long-term care insurance in 2000, the eligibility criteria and benefits were designed so that those who had been receiving services would be able to continue to do so. Five years later, benefits were reduced by a partial levying of hotel costs in institutional care, and restricting the provision of instrumental activities of daily living support services in community care for those requiring only light care. Whether these revisions are effective in containing costs and whether a decision should be made to cover all ages and all disabilities are the issues for the future.
Electrostatic wave generation and transverse ion acceleration by Alfvénic wave components of broadband extremely low frequency turbulence
Authors: Singh Nagendra , Khazanov George , Mukhter Ali
Published: June 2007

We present results here from 2.5‐dimensional particle‐in‐cell simulations showing that the electrostatic (ES) components of broadband extremely low frequency (BBELF) waves could possibly be generated by cross‐field plasma instabilities driven by the relative drifts between the heavy and light ion species in the electromagnetic (EM) Alfvénic component of the BBELF waves in a multi‐ion plasma. The ES components consist of ion cyclotron as well as lower hybrid modes. We also demonstrate that the ES wave generation is directly involved in the transverse acceleration of ions as commonly measured with the BBELF wave events. The heating is affected by ion cyclotron resonance in the cyclotron modes and Landau resonance in the lower hybrid waves. In the simulation, we drive the plasma by the transverse electric field, Ey, of the EM waves; the frequency of Ey, ωd, is varied from a frequency below the heavy ion cyclotron frequency, Ωh, to below the light ion cyclotron frequency, Ωi. We have also performed simulations for Ey having a continuous spectrum given by a power law, namely, ∣Ey∣ ∼ ωd−α, where the exponent α = , 1, and 2 in three different simulations. The driving electric field generates polarization and E × B drifts of the ions and electrons. When the interspecies relative drifts are sufficiently large, they drive electrostatic waves, which cause perpendicular heating of both light and heavy ions. The transverse ion heating found here is discussed in relation to observations from Cluster, Fast Auroral Snapshot, and Freja.
Dynamics of Strombolian ash plumes from thermal video: Motion, morphology, and air entrainment
Authors: Patrick Matthew R.
Published: June 2007

Imaging volcanic plumes is essential to provide an observational basis for understanding and modeling plume dynamics. During June–July 2004, ∼150 Strombolian ash plumes were imaged at Stromboli volcano, Italy, with a forward looking infrared radiometer (FLIR) thermal video camera (30 Hz). Of these, 25–80 plumes were suited for different levels of quantitative analyses. In this study some simple analyses are applied to constrain basic parameters for the dynamics of Strombolian plumes during their initial ascent (∼130 m). Plume rise rates covered both gas thrust (>15 m s−1) and buoyant regimes (<15 m s−1), which in turn controlled lateral spreading rates and air entrainment rates. The half angle of lateral spreading of the plume front averaged 7.3(±1.6)° for gas thrust regimes and 13.5(±1.6)° for buoyant regimes, equating to mean air entrainment coefficients of 0.06–0.12 for gas thrust regimes and 0.22(±0.03) for buoyant regimes. These factors were also linked to plume morphologies, which included jets, starting plumes and thermals. A “rooted thermal” form was observed and presumed as an intermediary between starting plumes and discrete thermals. Plume rise could be approximated by a power law dependence with time. Rooted thermals spread and entrained air at rates approaching those of a discrete thermal but rose at a rate similar to that of a starting plume. Phenomena including helical motion and sedimentation were visible in the FLIR imagery. These results demonstrate that emergent plume behavior is progressive and highly transient. Furthermore, this study offers empirical reinforcement that entrainment dynamics are intrinsically different in (1) gas thrust versus buoyantly driven regimes and (2) plume fronts versus steady plumes.
A sensitivity study of the coupled simulation of the Northeast Brazil rainfall variability
Authors: Misra Vasubandhu
Published: June 2007

Two long‐term coupled ocean‐land‐atmosphere simulations with slightly different parameterization of the diagnostic shallow inversion clouds in the atmospheric general circulation model (AGCM) of the Center for Ocean‐Land‐Atmosphere Studies (COLA) coupled climate model are compared for their annual cycle and interannual variability of the northeast Brazil (NEB) rainfall variability. It is seen that the solar insolation affected by the changes to the shallow inversion clouds results in large scale changes to the gradients of the SST and the surface pressure. The latter in turn modulates the surface convergence and the associated Atlantic ITCZ precipitation and the NEB annual rainfall variability. In contrast, the differences in the NEB interannual rainfall variability between the two coupled simulations is attributed to their different remote ENSO forcing.
Evolution of entanglement after a local quench
Authors: Eisler Viktor , Peschel Ingo
Published: June 2007

We study free electrons on an infinite half-filled chain, starting in the ground
state with a bond defect. We find a logarithmic increase of the entanglement
entropy after the defect is removed, followed by a slow relaxation towards the value
of the homogeneous chain. The coefficients depend continuously on the defect
strength.
Multiple Receptor Interactions Trigger Release of Membrane and Intracellular Calcium Stores Critical for Herpes Simplex Virus Entry
Authors: Cheshenko Natalia , Liu Wen , Satlin Lisa M. , Herold Betsy C.
Published: June 2007

Herpes simplex viruses (HSV) harness cellular calcium signaling pathways to facilitate viral entry. Confocal microscopy and small interfering RNA (siRNA) were used to identify the source of the calcium and to dissect the requisite viral–cell interactions. Binding of HSV to human epithelial cells induced no calcium response, but shifting the cells to temperatures permissive for penetration triggered increases in plasma membrane calcium followed by a global release of intracellular calcium. Transfection with siRNA targeting the proteoglycan syndecan-2 blocked viral binding and abrogated any calcium response. Transfection with siRNA targeting nectin-1, a glycoprotein D receptor, also prevented both membrane and intracellular calcium responses. In contrast, the membrane response was preserved after transfection with siRNA targeting integrinαv, a novel glycoprotein H receptor. The membrane response, however, was not sufficient for viral entry, which required interactions with integrinαv and release of inositol-triphosphate receptor-dependent intracellular calcium stores. Thus, calcium plays a critical, complex role in HSV entry.
Predicting survival from microarray data—a comparative study
Authors: Bøvelstad H.M. , Nygård S. , Størvold H.L. , Aldrin M. , Borgan Ø. , Frigessi A. , Lingjærde O.C.
Published: June 2007

Motivation: Survival prediction from gene expression data and other high-dimensional genomic data has been subject to much research during the last years. These kinds of data are associated with the methodological problem of having many more gene expression values than individuals. In addition, the responses are censored survival times. Most of the proposed methods handle this by using Cox's proportional hazards model and obtain parameter estimates by some dimension reduction or parameter shrinkage estimation technique. Using three well-known microarray gene expression data sets, we compare the prediction performance of seven such methods: univariate selection, forward stepwise selection, principal components regression (PCR), supervised principal components regression, partial least squares regression (PLS), ridge regression and the lasso.

Results: Statistical learning from subsets should be repeated several times in order to get a fair comparison between methods. Methods using coefficient shrinkage or linear combinations of the gene expression values have much better performance than the simple variable selection methods. For our data sets, ridge regression has the overall best performance.

Availability: Matlab and R code for the prediction methods are available at http://www.med.uio.no/imb/stat/bmms/software/microsurv/.

Contact:  hegembo@math.uio.no
Significance analysis of groups of genes in expression profiling studies
Authors: Chen James J. , Lee Taewon , Delongchamp Robert R. , Chen Tao , Tsai Chen-An
Published: June 2007

Motivation: Gene class testing (GCT) is a statistical approach to determine whether some functionally predefined classes of genes express differently under two experimental conditions. GCT computes the P-value of each gene class based on the null distribution and the gene classes are ranked for importance in accordance with their P-values. Currently, two null hypotheses have been considered: the Q1 hypothesis tests the relative strength of association with the phenotypes among the gene classes, and the Q2 hypothesis assesses the statistical significance. These two hypotheses are related but not equivalent.

Method: We investigate three one-sided and two two-sided test statistics under Q1 and Q2. The null distributions of gene classes under Q1 are generated by permuting gene labels and the null distributions under Q2 are generated by permuting samples.

Results: We applied the five statistics to a diabetes dataset with 143 gene classes and to a breast cancer dataset with 508 GO (Gene Ontology) terms. In each statistic, the null distributions of the gene classes under Q1 are different from those under Q2 in both datasets, and their rankings can be different too. We clarify the one-sided and two-sided hypotheses, and discuss some issues regarding the Q1 and Q2 hypotheses for gene class ranking in the GCT. Because Q1 does not deal with correlations among genes, we prefer test based on Q2.

Contact:  jchen@nctr.fda.gov

Supplementary information: Supplementary data are available at Bioinformatics online.
Cerebral asymmetries in sleep-dependent processes of memory consolidation
Authors: Peigneux Philippe , Schmitz Remy , Willems Sylvie
Published: June 2007

Preference for previously seen, unfamiliar objects reflects a memory bias on affective judgment, known as the “mere exposure effect” (MEE). Here, we investigated the effect of time, post-exposure sleep, and the brain hemisphere solicited on preference generalization toward objects viewed in different perspectives. When presented in the right visual field (RVF), which promotes preferential processing in the left hemisphere, same and mirrored exemplars were preferred immediately after exposure. MEE generalized to much dissimilar views after three nights of sleep. Conversely, object presentation in the left visual field (LVF), promoting right hemisphere processing, elicited a MEE for same views immediately after exposure, then for mirror views after sleep. Most importantly, sleep deprivation during the first post-exposure night, although followed by two recovery nights, extinguished MEE for all views in the LVF but not in the RVF. Besides demonstrating that post-exposure time and sleep facilitate the generalization process by which we integrate various representations of an object, our results suggest that mostly in the right hemisphere, sleep may be mandatory to consolidate the memory bias underlying affective preference. These interhemispheric differences tentatively call for a reappraisal of the role of cerebral asymmetries in wake- and sleep-dependent processes of memory consolidation.
GAP-43 gene expression regulates information storage
Authors: Holahan Matthew R. , Honegger Kyle S. , Tabatadze Nino , Routtenberg Aryeh
Published: June 2007

Previous reports have shown that overexpression of the growth- and plasticity-associated protein GAP-43 improves memory. However, the relation between the levels of this protein to memory enhancement remains unknown. Here, we studied this issue in transgenic mice (G-Phos) overexpressing native, chick GAP-43. These G-Phos mice could be divided at the behavioral level into “spatial bright” and “spatial dull” groups based on their performance on two hidden platform water maze tasks. G-Phos dull mice showed both acquisition and retention deficits on the fixed hidden platform task, but were able to learn a visible platform task. G-Phos bright mice showed memory enhancement relative to wild type on the more difficult movable hidden platform spatial memory task. In the hippocampus, the G-Phos dull group showed a 50% greater transgenic GAP-43 protein level and a twofold elevated transgenic GAP-43 mRNA level than that measured in the G-Phos bright group. Unexpectedly, the dull group also showed an 80% reduction in hippocampal Tau1 staining. The high levels of GAP-43 seen here leading to memory impairment find its histochemical and behavioral parallel in the observation of Rekart et al. (Neuroscience126: 579–584) who described elevated levels of GAP-43 protein in the hippocampus of Alzheimer’s patients. The present data suggest that moderate overexpression of a phosphorylatable plasticity-related protein can enhance memory, while excessive overexpression may produce a “neuroplasticity burden” leading to degenerative and hypertrophic events culminating in memory dysfunction.
Aberrant nuclear p53 protein expression detected by immunohistochemistry is associated with hemizygous P53 deletion and poor survival for multiple myeloma
Authors: Chang Hong , Yeung Joanna , Qi Connie , Xu Wei
Published: June 2007

Hemizygous TP53 deletion is an adverse risk factor in multiple myeloma (MM) but its relationship with p53 protein expression is unclear. We investigated 105 newly diagnosed myeloma patients and correlated nuclear p53 protein immunoreactivity with TP53 deletion status, myeloma‐associated genetic risk factors and survival. Fluorescence in situ hybridisation (FISH) detected hemizygous TP53 deletions in 13 (12%) patients while immunohistochemistry detected nuclear p53 protein expression in 12 (11%). Ten (77%) of the 13 del(TP53) cases expressed nuclear p53 protein while 10 (83%) of the 12 nuclear p53 immunoreactive cases had hemizygous TP53 deletions. Hemizygous TP53 deletion and p53 protein expression were strongly correlated (P < 0·001). The overall survival of patients with p53 protein expression was significantly shorter than that of patients without p53 expression (P < 0·001). A multivariate analysis including other myeloma‐associated genetic risk factors confirmed p53 expression as an independent risk factor for survival. Our data indicate that nuclear p53 protein expression, detected by a widely available immunohistochemical method, is strongly associated with TP53 deletion and an adverse clinical outcome for MM.
Relationship between cortisol and physical performance in older persons
Authors: Peeters G. M. E. E. , Van Schoor N. M. , Visser M. , Knol D. L. , Eekhoff E. M. W. , De Ronde W. , Lips P.
Published: June 2007

Objective Hypercortisolism is associated with muscle weakness. This study examines the relationship between cortisol and physical performance in older persons.

Design/patients The study was conducted within the Longitudinal Aging Study Amsterdam (LASA), an ongoing cohort study in a population‐based sample of healthy older persons in the Netherlands. Data from the second (1995/1996) and fourth (2001/2002) cycle were used pertaining to 1172 (65–88 years) and 884 (65–94 years) men and women, respectively.

Measurements Physical performance was measured by adding up scores on the chair stands, tandem stand and walk test (range 0–12). In the second cycle serum total and calculated free cortisol were assessed; in the fourth cycle evening salivary cortisol was assessed. Regression analysis (stratified for sex, adjusted for age, body mass index, alcohol use, physical activity and region) was performed to examine the cross‐sectional relationship between cortisol and physical performance.

Results Women with higher calculated free cortisol scored less well on physical performance (b = –0·28 per SD higher cortisol,P = 0·016), which was mainly explained by poorer performance on the tandem stand (OR = 1·32 for a lower score per SD higher cortisol,P = 0·003). Men with higher salivary cortisol scored less well on physical performance (b = –0·90 in the highestvs.the lowest quartile,P = 0·008), which was mainly explained by poorer performance on the chair stands and walk test (OR = 1·88,P = 0·020 and OR = 1·81,P = 0·027, respectively, in the highestvs.the lowest quartile).

Conclusion Physical performance is negatively associated with high cortisol levels in older persons.
Efficacy of a slow‐release formulation of lanreotide (Autogel® 120 mg) in patients with acromegaly previously treated with octreotide long acting release (LAR): an open, multicentre longitudinal study
Authors: Ronchi C. L. , Boschetti M. , Uberti E. C. Degli , Mariotti S. , Grottoli S. , Loli P. , Lombardi G. , Tamburrano G. , Arvigo M. , Angeletti G. , Boscani P. F. , Beck‐Peccoz P. , Arosio M. ,   for the Italian Multicenter Autogel Study Group in Acromegaly
Published: June 2007

Objective   Lanreotide Autogel® 120 mg (ATG120; Ipsen S.p.A, Milan, Italy) is a high‐dose, sustained‐release aqueous gel formulation, supplied in a prefilled syringe and given by deep subcutaneous injection. The aim of this study was to compare efficacy and tolerability of ATG120 given every 4–8 weeks with those of octreotide LAR (o‐LAR) given every 4 weeks.

Design patients and intervention   A phase III multicentre Italian open clinical study of 23 acromegalic patients (15 female, 8 male). All patients had received o‐LAR for 6–18 months and, after 3 months wash out, ATG120 was given every 6 weeks for a total of four injections (Period 1). Then the interval between ATG120 injections was adjusted according to three different schemes: every 4, 6 or 8 weeks depending on GH levels (GH > 2·5 µg/l; 1 < GH ≤ 2·5 µg/l; GH ≤ 1 µg/l, respectively). ATG120 was given for a further two to three doses, with a final assessment (Period 2) at Week 34, 36 or 42.

Measurements   Hormonal (GH and IGF‐I) and clinical efficacy and tolerability.

Results   ATG120 induced a significant GH decrease from 9·9 ± 11·3 at baseline (Visit 1) to 3·5 ± 5·7 at the end of Period 1 (P < 0·01) and to 3·8 ± 5·7 µg/l at the final visit (P < 0·01). IGF‐I also decreased from 544 ± 312 at baseline (Visit 1) to 318 ± 181 at Period 1 and to 356 ± 187 µg/l at the final visit (both P < 0·05 vs. baseline). The frequency of ATG120 administrations was adjusted to every 4 weeks in 12 patients, every 6 weeks in 4 patients and every 8 weeks in 6 patients; 1 patient withdrew before the dose adjustment. Serum GH and IGF‐I achieved at the end of Period 1 and Period 2 were similar to those reached with o‐LAR. The number of patients who achieved GH < 2·5 µg/l was comparable between o‐LAR (43%) and ATG120 at Period 1 (48%) and at Period 2 (62%). Normal IGF‐I levels were recorded in 8 patients during o‐LAR (35%), 11 during ATG Period 1 (48%) and 10 at the final visit (43%). Last, 4 patients showed a better response to ATG120 and 2 to o‐LAR.

Conclusions   Lanreotide Autogel 120 mg is an effective and well‐tolerated therapy for acromegaly. In approximately half of patients ATG120 may be administered every 6–8 weeks, instead of every 4 weeks, without lost of efficacy.