A co-operative parallel heuristic for integer linear programming: Combining simulated annealing with branch & bound

This paper considers the exact approach of branch and bound (B&B) and the metaheuristic known as simulated annealing (SA) for processing integer programs (IP). We extend an existing SA implementation (GPSIMAN) for pure zero–one integer programs (PZIP) to process a wider class of IP models, namely mixed zero–one integer programs (MZIP). The extensions are based on depth-first B&B searches at different points within the SA framework. We refer to the resultant SA implementation as MIPSA. Furthermore, we have exploited the use of parallel computers by designing a co-operative parallel heuristic whereby concurrent executions of B&B and MIPSA, linked through a parallel computer, exchange information in order to influence their searches. Results reported for a wide range of models taken from a library of MIP benchmarks demonstrate the effectiveness of using a parallel computing approach which combines B&B with SA

FISCAL CONSOLIDATION AND DECENTRALISATION: A TALE OF TWO TIERS

This paper contributes to the established literature on fiscal consolidations (e.g. Alesina and Perotti, 1995, 1997, Alesina et al, 1998) by investigating the distinct behaviour of central and sub-central tiers of government during general government consolidation attempts. In the light of different degrees of decentralisation across OECD countries, and the different responsibilities devolved to sub-central tiers, we believe that this approach offers an illuminating insight into the analysis of fiscal consolidations and their success. We show that the involvement of the sub-central tiers of government is crucial to achieving cuts in expenditure, particularly in relation to the overall size of the government wage bill. In addition, central governments appear to exert a strong influence on the expenditure of subcentral tiers through their grant allocations, and control of these allocations appears to have a considerable impact upon the overall success of consolidation attempts. Finally we demonstrate that there is a skewness in cuts towards sub-central capital expenditure both when central governments cut grant allocations and when sub-central governments engage in lone consolidation attempts.

Fiscal Federalism and Fiscal Consolidation: Evidence from an Event Study

Fiscal consolidations, episodes where governments make large discretionary improvements in their fiscal positions, have received considerable attention, especially in EMU. The existing literature demonstrates that the composition of consolidations is a crucial determinant of their success. We show that sub-central governments also play a key role in consolidations through sustained cuts in expenditures, as their intergovernmental grants are cut. In contrast to existing studies we find that cuts in capital spending at sub-central levels are a feature of successful consolidations. We also show that the government type and the nature of fiscal arrangements in a country impact on these results.

A Two Stage Parallel Branch and Bound Algorithm for Mixed Integer programs

Mixed integer programming (MIP) models are extensively used to aid strategic and tactical decision making in many business sectors. Solving MIP models is a computationally intensive process and there is a need to develop solution approaches that enable larger models to be solved within acceptable timeframes. In this paper, we describe the implementation of a two-stage parallel branch and bound (PB & B) algorithm for MIP. In stage 1 of the algorithm, a multiple heuristic search is implemented in which a number of alternative search trees are investigated using a forest search in the hope of finding a good solution quickly. In stage 2, the search is reorganized so that the branches of a chosen tree are investigated in parallel. A new heuristic is introduced, based on a best projection criterion, which evaluates alternative B & B trees in order to choose one for investigation in stage 2 of the algorithm. The heuristic also serves as a way of implementing a quality load balancing scheme for stage 2 of the algorithm. The results of experimental investigations are reported for a range of models taken from the MIPLIB library of benchmark problems

Paraplegia and squamous cell carcinoma of the bladder in young women: findings from a case-control study.

A death certificate-based case-control study was conducted on 207 women aged 25-44 who died of bladder cancer in England and Wales in the period 1971-89 and 411 controls matched on sex, year of death and age at death. An odds ratio of 12.0 (95% CI 1.5-99.7) was found for women with a history of paraplegia. Four of the six paraplegic women were reported to have had squamous cell carcinoma of the bladder compared with only 19 of the 201 non-paraplegic women. These findings suggest that squamous cell carcinomas of the bladder, especially in paraplegics, may be the result of chronic urinary tract infection

Shear strengthening of continuous reinforced concrete T-beams using deep embedment technique

Despite numerous studies, shear behaviour before or after strengthening is still not fully understood, particularly in continuous concrete structures which are the norm. Upgrading shear resistance is altogether more difficult since Externally Bonded Reinforcement (EBR) or Near Surface Mounted (NSM) techniques do not allow the FRP material to be anchored into the compression zone of the T-beams and they cannot be used in cases where the sides of the beams are inaccessible. An innovative retrofit technique, named Deep Embedment (DE) or Embedded Through Section (ETS) technique involves the insertion of FRP/steel bars upwards into vertical or inclined holes which have been drilled from the soffit of concrete beams. In this way, the tension and compression chords of the beams are directly connected while the bars are bonded to the concrete core through adhesives. With this technique strengthening can be done in cases where the webs are inaccessible. Thus the main focus of this study is to significantly contribute to the current knowledge on the behaviour of Reinforced Concrete continuous T-beamsstrengthened in shear using the DE technique where large shear forces are combined with large negative bending moments. An experimental program consisting of ten two-span continuous T-beams designed to fail in shear wascarried out in order to significantly contribute to the current knowledge on the behaviour of RC continuous Tbeams strengthened in shear using this technique. Therefore, this paper reports on the test results and on their significance in being able to apply this technique on concrete structures by validating them through adequate analytical models

Selective Regulation of Aromatase Expression for Drug Discovery

Aromatase is a particularly attractive drug target in the treatment of hormone-responsive breast cancer, and aromatase activity in breast cancer patients is greater in or near the tumor tissue compared with the normal breast tissue. Complex regulation of aromatase expression in human tissues involves alternative promoter sites that provide tissue-specific control. Previous studies in our laboratories suggested a strong association between aromatase (CYP19) gene expression and the expression of cyclooxygenase (COX) genes. Additionally, COX selective inhibitors can suppress CYP19 gene expression and decrease aromatase activity. Our current hypothesis is that pharmacological regulation of aromatase can act locally to decrease the biosynthesis of estrogen and may provide additional therapy options for patients with hormone-dependent breast cancer. Two pharmacological approaches are being developed, one approach utilizing small molecule drug design and the second approach involving mRNA silencing technology. The small molecule drug design approach focuses on the synthesis and biological evaluation of a novel series of sulfonanilide analogs derived from COX-2 selective inhibitors. Combinatorial chemistry approaches were used to generate diversely substituted novel sulfonanilides. The compounds suppress aromatase enzyme activity in SK-BR-3 breast cancer cells in a dose and time dependent manner, and structure activity analysis does not find a correlation between aromatase suppression and COX inhibition. Real-time PCR analysis demonstrates that the sulfonanilide analogs decrease aromatase gene transcription in breast cells. Furthermore, the sulfonanilide compounds selectively decrease aromatase gene expression in several breast cancer cells, without exhibiting cytotoxic or apoptotic effects at low micromole concentrations. A ligand-based pharmacophore model for selective aromatase modulation (SAM) by the novel sulfonanilides identified an aromatic ring, two hydrogen bond acceptors, and a hydrophobic function as four key chemical features. In the second approach, short interfering RNAs (siRNA) were designed targeting human aromatase mRNA. Treatment of breast cancer cells with siRNAs targeting aromatase (siAROMs) completely masked the aromatase enzyme activity and resulted in suppression of CYP19 mRNA. Thus, these results suggest that the novel sulfonanilides and the siRNAs targeting aromatase expression may be valuable tools for selective regulation of aromatase in breast cancer

Tests of amounts and times of application of nitrogen and of sequential sprays of aphicide and fungicides on winter wheat, following either beans or wheat, and the effects of take-all (Gaeumannomyces graminis var. tritici ), on two varieties at Saxmundham, Suffolk 1980-3

RESP-9258 and RESP-924

Which yeast species shall I choose? Saccharomyces cerevisiae versus Pichia pastoris (review)

Having decided on yeast as a production host, the choice of species is often the first question any researcher new to the field will ask. With over 500 known species of yeast to date, this could pose a significant challenge. However, in reality, only very few species of yeast have been employed as host organisms for the production of recombinant proteins. The two most widely used, Saccharomyces cerevisiae and Pichia pastoris, are compared and contrasted here