bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of recent circulation and thermal advection change in the northern Antarctic Peninsula
Authors: Marshall Gareth J. 
Published: October 2002

AbstractChanges in circulation at 500 and 850 hPa and horizontal thermal advection between these two levels are examined at Bellingshausen station in the northern Antarctic Peninsula between 1969 and 2000. A synthesis of radiosonde observations and reanalysis data is employed, the latter being ‘corrected’ to remove any bias and trend versus the observations. These data only reveal statistically significant increases in the annual zonal wind component; although the mean direction of the thermal advection is 339° there is no indication of increasing northerlies coincident with the remarkable regional surface warming. Seasonally, the zonal wind is most highly correlated with surface temperature in autumn and winter, the seasons showing the greatest temperature rise. This suggests that the increasing westerlies have played a role in the recent warming, and several authors have postulated that this results from a trend towards the positive phase of the Southern Hemisphere annular mode (SAM). However, a comparison between a regional zonal circulation index derived independently from observations and the reanalysis data used in past studies of the SAM indicates long‐term increases in the latter may be an artefact caused by errors in the early reanalysis data. While observations do indicate an increase in the zonal wind since the late 1970s, coincident with a decline in the strength of the semi‐annual oscillation, there is no clear evidence of circulation changes driving the long‐term Antarctic Peninsula surface warming. Copyright © 2002 Royal Meteorological Society.
Hypothalamic digoxin and hypomagnesemia in human pre‐eclampsic toxemia, cortical venous thrombosis, and postpartum psychosis
Authors: Kurup Ravi Kumar , Kurup Parameswara Achutha 
Published: October 2002

AbstractThe isoprenoid pathway produces three key metabolites—digoxin (membrane sodium‐potassium ATPase inhibitor and regulator of neurotransmitter transport), dolichol (regulates N‐glycosylation of proteins), and ubiquinone (free radical scavenger). The pathway was assessed in patients with pre‐eclampsic toxaemia, cortical venous thrombosis, and postpartum psychosis. It was also studied for comparison in patients with right hemispheric, left hemispheric, and bihemispheric dominance. The results of the study showed that the isoprenoid pathway was upregulated with increased digoxin synthesis in all the three groups of patients. There was also a reduction in red blood cell (RBC) membrane Na+–K+ ATPase activity and serum magnesium levels. There was an increase in serum tryptophan catabolites and reduction in tyrosine catabolites. The serum dolichol and glycoconjugate levels were increased and lysosomal stability reduced with increased plasma lysosomal enzymes in all the three groups. The serum ubiquinone levels were low, and RBC free radical parameters increased. The RBC membrane cholesterol: phospholipid ratio was increased, and glycoconjugate was reduced in the membrane of these patients. This pattern correlated with those in right hemispheric dominance. The isoprenoid pathway and hypothalamic digoxin may thus play a crucial role in the pathogenesis of CVT, PET, and postpartum psychosis. J. Trace Elem. Exp. Med. 15:171–190 2002. © 2002 Wiley‐Liss, Inc.
Milk selenium content is enhanced by modest selenium supplementation in extended lactation
Authors: Dylewski Maggie L. , Picciano Mary Frances 
Published: October 2002

AbstractSupplemental selenium (Se) as selenate, selenomethionine, or Se‐enriched yeast at 100–200 μg Se/day causes an increase or prevents a decline in human milk selenium content during the first 6 months of lactation. In this study, we evaluated the impact of supplemental Se as sodium selenate at 20 μg/day, an amount that closely approximates the quantity of selenium lost daily via milk secretion. Lactating women (n = 23) provided dietary data and milk and plasma samples at 3 and 6 months postpartum. At 3 months postpartum, all women received a daily vitamin/mineral supplement that furnished 20 μg of Se as sodium selenate for 3 months. Mean Se intake from self‐selected diets was 111 ± 40 μg/day and did not differ between 3 and 6 months. Selenium supplementation increased milk Se from 3 (295 ± 18 nmol/L; 23 ± 7 ng/mL) to 6 months (417 ± 39 nmol/L; 32 ± 14 ng/mL) postpartum (P ≤ 0.01) and corresponding infant Se intakes from 12 μg/day to 20 μg/day. Maternal plasma Se concentration was 1.46 ± 0.42 μmol/L (115 ± 33 ng/mL) at 3 months and 1.76 ± 0.20 μmol/L (155 ± 16 ng/mL) at 6 months postpartum, but this apparent difference was not significantly different. Maternal supplemental Se at 20 μg/day caused a 41% increase in human milk Se and a corresponding 67% increase in infant Se intake. Data show that supplemental Se at or near the quantity secreted daily is sufficient to prevent a decline in human milk Se with advancing lactation. J. Trace Elem. Exp. Med. 15:191–199, 2002. © 2002 Wiley‐Liss, Inc.
Hypothalamic digoxin and hypomagnesemia in relation to the pathogenesis of multiple sclerosis
Authors: Kurup Ravi Kumar , Kurup Parameswara Achutha 
Published: October 2002

AbstractThis study assessed the isoprenoid pathway‐related biochemical cascade in multiple sclerosis, and in this work we discuss the pivotal role of hypothalamic digoxin and membrane sodium‐potassium ATPase inhibition in the pathogenesis of multiple sclerosis. Our results showed that there was an elevation in plasma HMG CoA reductase activity, serum digoxin, and dolichol levels and a reduction in red blood cell (RBC) membrane sodium potassium ATPase activity, serum ubiquinone, and magnesium levels. Serum tryptophan, serotonin, strychnine, nicotine, and quinolinic acid were elevated whereas tyrosine, dopamine, morphine, and noradrenaline were decreased. The total serum glycosaminoglycans, hyaluronic acid, heparin, and heparan sulphate were elevated and levels of chondroitin sulphates and dermatan sulphate were reduced in multiple sclerosis. The serum glycolipids as well as the hexose, fucose, and sialic acid carbohydrate residues of serum glycoproteins were elevated. The activity of glycosaminoglycan degrading enzymes was elevated. The activity of glycohydrolases—beta galactosidase and beta fucosidase—were increased and beta glucosidase reduced in the serum. The RBC membrane glycosaminoglycan, the hexose and fucose carbohydrate residues of glycoproteins, and the cholesterol:phospholipid ratio of the RBC membrane were decreased in multiple sclerosis. Membrane Na+‐K+ ATPase inhibition‐related increased intracellular calcium can produce immune activation via the calcineurin signal transduction system in T cells. Digoxin‐induced altered glycoconjugate metabolism can change the structural integrity of myelin as well as result in immune dysregulation caused by defective presentation of myelin glycoprotein antigens to CD8 cells. Digoxin‐induced defective membrane formation of oligodendrocyte membrane can inhibit remyelination. Digoxin‐related mitochondrial dysfunction can contribute to free radical generation, microglial activation, and oligodendrocyte apoptosis that are important in demyelination. J. Trace Elem. Exp. Med. 15:211–220, 2002. © 2002 Wiley‐Liss, Inc.
Effects of marathon running on the trace minerals chromium, cobalt, nickel, and molybdenum
Authors: Berger Christian E. , Kröner Andreas , Kluger Rainer , Baron Ramon , Steffan Ilse , Engel Alfred 
Published: October 2002

AbstractThere is considerable debate on the effects of endurance stress on concentrations of trace minerals and as to whether athletes, who restrict calories to maintain low body weights, could comprise their trace mineral levels. In a prospective study, the effect of running a marathon course on whole blood levels of chromium, cobalt, nickel, and molybdenum was evaluated. Blood samples of 13 test runners (2 females, 11 males) were obtained twice before, immediately after, and 1 week after running a marathon. The analyses of the concentrations in whole blood were performed using graphite tube atom absorption spectrometry (GFAAS). The chromium level of the samples ranged between 1.3 ng/g and 19.3 ng/g. Mean chromium concentrations were elevated before and immediately after the marathon (4.3–7.4 ng/g) and decreased to an average of 2.7 ng/g after the marathon course. The difference between chromium concentrations obtained immediately after and 1 week after the marathon course was significant. Levels of chromium exhibited a high variability; however, the percentage of concentrations below the detection limit was 0%. Similarly, owing to different individual response to strenuous exercise, concentrations of nickel, molybdenum, and cobalt were highly variable, exceeding normal limits by 47.3%, 25.1%, and 4.6%, respectively. Mean concentrations of nickel, cobalt, and molybdenum ranged from 4.3–22.7 ng/g (Ni), 0.16–2.2 ng/g (Co), and 0.2–0.7 ng/g (Mo); the difference was not significant at any time. The current study was able to show that running a marathon course does not lead to significant changes in the whole blood levels of cobalt, nickel and molybdenum. Chromium levels, however, were significantly decreased immediately after the marathon course, a finding that corresponds well with previous observations of increased mobilization of chromium from body stores and subsequently elevated serum levels. J. Trace Elem. Exp. Med. 15:201–209, 2002. © 2002 Wiley‐Liss, Inc.
Assessing academic department efficiency at a public university
Authors: Moreno Abel A. , Tadepalli Raghu 
Published: October 2002

AbstractThe assessment of public universities has gained importance because of the demands from such state government bodies as the executive and the legislature. Public universities are increasingly being asked to account for how efficiently they have used diminishing state financial resources. Administrators thus have the responsibility of ensuring that the university's financial, human, and physical resources are allocated to academic departments in a manner that enhances the institution's efficiency. In this paper, data envelopment analysis (DEA) is proposed for evaluating the efficiency of academic departments at a public university. DEA provides a single measure of efficiency for each academic unit. It also identifies the causes behind the inefficiencies exhibited by poor performing units, as well as the changes that these units need to make in order to improve their efficiencies. Its usefulness as a planning tool is also discussed. Copyright © 2002 John Wiley & Sons, Ltd.
Beyond profitability: effects of acquisitions on technical efficiency in the Italian pasta industry
Authors: Benfratello Luigi 
Published: October 2002

AbstractUnlike traditional studies on the impact of ownership changes—which use either profitability measures or stock prices—this paper investigates the impact of acquisitions on acquired firms' technical efficiency. Using a panel of Italian firms in the pasta industry for the 1981–1997 period, I estimate a stochastic production frontier with exogenous factors affecting efficiency in a translog specification with non‐neutral technical progress. The main result is that acquired firms experience, within the 6 years period following the acquisition, an increase in technical efficiency of the order of 10%. This result is statistically significant and proves to be robust with respect to the inclusion of size and calendar year effects as explanatory variables of firms' inefficiency. These findings contribute to the debate on the welfare gains of ownership changes by providing evidence that mergers and acquisitions lead to cost savings, due to the reduction of acquired firms' X‐inefficiency. Copyright © 2002 John Wiley & Sons, Ltd.
Tax‐loss carryforward and futures hedging
Authors: Lien Donald , Metz Michael 
Published: October 2002

AbstractOur research is motivated by the Corn Products vs Arkansas Best Supreme court decisions that brought on the controversy of the tax treatment of gains and losses from futures hedging. The usefulness of a futures contract as risk management tool depends on the tax code. In this paper we address implications of capital treatment of futures positions (disallowing offset for tax purposes) when tax‐loss carryover is allowed. Our analysis utilizes a two‐period model to capture the inter‐temporal effects. We investigate the optimal hedge ratios under these scenarios analytically where possible, and numerically where necessary. Copyright © 2002 John Wiley & Sons, Ltd.
Equity and arbitration in major league baseball
Authors: Fizel John , Krautmann Anthony C. , Hadley Lawrence 
Published: October 2002

AbstractEquity theory argues that workers examine their job performance and salaries relative to workers in comparable situations. If compensation is inequitable, workers may adjust their behavior. We test the hypothesis that an arbitration‐eligible player in Major League Baseball is more likely to file for arbitration and/or proceed to an arbitration hearing if he feels he is underpaid relative to his comparison other. Bivariate probit is used to increase efficiency and correct for the sample bias in estimating decision models within the two‐step arbitration process. The results indicate that equity is a significant predictor of a player's unilateral decision to file but is an insignificant determinant of going to a hearing because of offsetting responses to equity by player and owner. Copyright © 2002 John Wiley & Sons, Ltd.
Design of fault‐tolerant networks for satellites (TWTA redundancy)
Authors: Bermond Jean‐Claude , Darrot Eric , Delmas Olivier 
Published: October 2002

AbstractThis article deals with the design of networks to be placed on satellites. These networks should connect inputs (corresponding to signals arriving at the satellite) to outputs (corresponding to amplifiers, also called Traveling Wave Tube Amplifiers (TWTA)), even in case of failures of amplifiers. The networks are made of links and expensive switches; hence, we want to minimize the number of switches subject to the following conditions: Each input and each output is connected to exactly one switch; each switch is adjacent to exactly four links; there are n inputs and n + k outputs; among the n + k outputs, k can fail permanently; and, finally, all the input signals should be sent to valid amplifiers, that is, outputs, via disjoint paths. So, the aim is to design networks having as few switches as possible and satisfying the following property: There exist n edge‐disjoint paths from the n inputs to any set of n outputs chosen from the n + k total number of outputs. We call such networks valid k‐fault tolerant networks. Let 𝒩(n, k) denote the minimum number of switches of a valid network with n inputs, n + k outputs, and k output failures. In this article, we give some details on the problem and some preliminary results such as the fact that 𝒩(n, k) ≥ n. We also propose a general construction which yields (under some conditions) 𝒩(n + n′, k) ≤ 𝒩(n, k) + 𝒩(n′, k). © 2002 Wiley Periodicals, Inc.
On the online shortest path problem with limited arc cost dependencies
Authors: Waller S. Travis , Ziliaskopoulos Athanasios K. 
Published: October 2002

AbstractThis paper is concerned with the stochastic shortest path problem with recourse when limited forms of spatial and temporal arc cost dependencies are accounted for. Recourse is defined as the opportunity for a decision maker to reevaluate his or her remaining path when en‐route information is available. Formulations with recourse typically provide opportunities for corrective actions when information becomes available; information here is modeled as arc cost dependencies, defined as spatial and temporal. System properties are stated and proved and solution algorithms are developed for limited cases of spatial and temporal arc cost dependencies. The numerical results verify some of the theoretical insights and demonstrate the applicability of the introduced algorithms. © 2002 Wiley Periodicals, Inc.
Multistars and directed flow formulations
Authors: Gouveia Luis , Hall Leslie 
Published: October 2002

AbstractThe Capacitated Minimum Spanning Tree Problem seeks a least‐cost spanning tree subject to a bound imposed on the number of nodes in each subtree pending from a given root node. Araque et al. (Technical Report SOR‐90‐12, Princeton University, 1990) introduced several classes of facet‐defining inequalities for the undirected version of the problem, most of which have straightforward analogs to the directed version and are also facet‐defining in that case (see Zhang, Master's thesis, 1993). The multistar constraints are one such class. Gouveia [Telecommun Syst 1 (1993), 51–56] showed that a directed flow formulation gives a polynomial representation of the class of directed multistar constraints. This equivalence shows how to obtain a polynomial‐time separation algorithm for this class of inequalities. In this paper, we show that the previous equivalence result implies that we can also separate in polynomial time the exponential‐sized class of undirected multistar constraints. We also show that “using a directed model” plays a key role in obtaining a polynomial‐time separation algorithm for this class of inequalities, that is, using a directed flow model seems to be crucial for obtaining a polynomial‐time separation algorithm for the class of undirected multistar constraints. © 2002 Wiley Periodicals, Inc.
Efficient algorithms for finding the (k, l)‐core of tree networks
Authors: Becker Ronald I. , Lari Isabella , Storchi Giovanni , Scozzari Andrea 
Published: October 2002

AbstractGiven a tree T = (V, E), with |V| = n, we consider the problem of selecting a subtree with at most k leaves and with a diameter of at most l which minimizes the sum of the distances of the vertices from the selected subtree. We call such a subtree the (k, l)‐core of T. We provide two algorithms; the first one for unweighted trees has time complexity of O(n2), whereas the second one for weighted trees has time complexity of O(n2log n). The idea for both the algorithms is that, by starting from the tree T, we construct new rooted trees where the maximum length of a path is at most l. Then, for each new tree, we can apply a greedy‐type procedure to find a subtree containing the root with at most k leaves and which minimizes the sum of the distances. © 2002 Wiley Periodicals, Inc.
The maximum principle violations of the mixed‐hybrid finite‐element method applied to diffusion equations
Authors: Hoteit H. , Mosé R. , Philippe B. , Ackerer Ph. , Erhel J. 
Published: October 2002

AbstractThe abundant literature of finite‐element methods applied to linear parabolic problems, generally, produces numerical procedures with satisfactory properties. However, some initial–boundary value problems may cause large gradients at some points and consequently jumps in the solution that usually needs a certain period of time to become more and more smooth. This intuitive fact of the diffusion process necessitates, when applying numerical methods, varying the mesh size (in time and space) according to the smoothness of the solution. In this work, the numerical behaviour of the time‐dependent solutions for such problems during small time duration obtained by using a non‐conforming mixed‐hybrid finite‐element method (MHFEM) is investigated. Numerical comparisons with the standard Galerkin finite element (FE) as well as the finite‐difference (FD) methods are checked. Owing to the fact that the mixed methods violate the discrete maximum principle, some numerical experiments showed that the MHFEM leads sometimes to non‐physical peaks in the solution. A diffusivity criterion relating the mesh steps for an artificial initial–boundary value problem will be presented. One of the propositions given to avoid any non‐physical oscillations is to use the mass‐lumping techniques. Copyright © 2002 John Wiley & Sons, Ltd.
A continuum sensitivity method for finite thermo‐inelastic deformations with applications to the design of hot forming processes
Authors: Ganapathysubramanian Shankar , Zabaras Nicholas 
Published: October 2002

AbstractA computational framework is presented to evaluate the shape as well as non‐shape (parameter) sensitivity of finite thermo‐inelastic deformations using the continuum sensitivity method (CSM). Weak sensitivity equations are developed for the large thermo‐mechanical deformation of hyperelastic thermo‐viscoplastic materials that are consistent with the kinematic, constitutive, contact and thermal analyses used in the solution of the direct deformation problem. The sensitivities are defined in a rigorous sense and the sensitivity analysis is performed in an infinite‐dimensional continuum framework. The effects of perturbation in the preform, die surface, or other process parameters are carefully considered in the CSM development for the computation of the die temperature sensitivity fields. The direct deformation and sensitivity deformation problems are solved using the finite element method. The results of the continuum sensitivity analysis are validated extensively by a comparison with those obtained by finite difference approximations (i.e. using the solution of a deformation problem with perturbed design variables). The effectiveness of the method is demonstrated with a number of applications in the design optimization of metal forming processes. Copyright © 2002 John Wiley & Sons, Ltd.
All‐hexahedral element meshing: automatic elimination of self‐intersecting dual lines
Authors: Calvo Nestor A. , Idelsohn Sergio R. 
Published: October 2002

AbstractThere has been some degree of success in all‐hexahedral meshing. Standard methods start with the object geometry defined by means of an all‐quadrilateral mesh, followed by the use of the combinatorial dual to the mesh in order to define the internal connectivities among elements. For all of the known methods using the dual concept, it is necessary to first prevent or eliminate self‐intersecting (SI) dual lines of the given quadrilateral mesh. The relevant features of SI lines are studied, giving a method to remove them, which avoids deforming the original geometry. Some examples of resulting meshes are shown where the current meshing method has been successfully applied. Copyright © 2002 John Wiley & Sons, Ltd.
Life‐cycle cost optimization of steel structures
Authors: Sarma Kamal C. , Adeli Hojjat 
Published: October 2002

AbstractThis article addresses the life‐cycle cost optimization of steel structures. The main factors influencing the life‐cycle cost of a structure are delineated and their effects on various cost functions are discussed. A four‐criteria optimization model is presented for the life‐cycle cost optimization of steel structures. These criteria are (i) select discrete commercially available sections with the lowest cost, (ii) select commercially available sections with the lightest weight, (iii) select the minimum number of different types of commercially available sections, and (iv) select commercially available sections with the minimum total perimeter length. The last criterion models a representative type of cost incurred over the life of the structure, that is, preventative maintenance in the form of periodic painting of an exposed steel structure to avoid corrosion. The life‐cycle cost optimization model is based on fuzzy logic with the goal of formalizing the life‐cycle design process but with some input from the design engineer through introduction of weighting coefficients reflecting the relative importance of various criteria. The model is applied to a large steel structure with over 3300 members. Copyright © 2002 John Wiley & Sons, Ltd.