One well known method for finding the intersection of two curves is based on Gröbner bases (see [10] or [2] for an explanation). When using this method the coefficients can grow very quickly impairing efficiency. Indeed, if the coefficients grow too large, the method will run out of memory. Kalorkoti [4] puts forth a new method that is designed to address this problem of coefficient growth. How...

This paper surveys recent research findings concerning th& size and importance of labor-supply changes resulting from U.S. income taxes and transfers. Our review of the literature of recent years leads us to conclude that the aggregate amount of work reduction that is attributable to taxes and transfers is relatively modest. Moreover, this reduction may be partly offset by the beneficial effect...

La didáctica de las ciencias es cada vez más activa, por lo que una metodología ampliamente utilizada el Aprendizaje Basado en Problemas (ABP). Este método implica la resolución un problema, se recoge informe denominado Informe problemas (IRP). Para los estudiantes esta tarea representa gran desafío, ya actuar y expresarse del modo harían expertos área. Es debido a dificultad hace imprescindibl...

RESUME : Le problème de tournées de véhicules avec gestion de stock (IRP) consiste à déterminer le circuit de distribution, d'un entrepôt central vers un ensemble de clients, qui optimise conjointement les coûts de transport et de stockage. Plusieurs travaux montrent l’intérêt de politiques comme le transbordement (transhipment) ou les tournées dynamiques sur les performances du système. Cepend...

Spatial interaction models are used to simulate interactions between a set of demands in a given area and a set of facilities, products or services that meet these demands. When coupled with some optimisation scheme, these models can be used to plan networks of outlets that provide maximum sales, profit or service results. Software developed by GMAP Ltd. combines a spatial interaction model wit...

A 10 centre calibration was performed after six years to determine the international sensitivity index (ISI) of rTF/95 relative to RBT/90, and to assess any international normalised ratio (INR) bias compared with the original multicentre calibration. After exclusion of one outlying centre, the follow up calibration gave a mean ISI for rTF/95 of 0.99, which although a small difference, is signif...

The Industrial Restructuring Project (IRP) was initiated at the beginning of 1996 as the KwaZulu-Natal Industrial Restructuring Project (KZN IRP). The project initially focused exclusively on KwaZuluNatal, but is now aimed at supporting industrial policy in South Africa at the national, provincial and local levels. It is facilitated by international experts and is based at the School of Develop...

ALL MAMMALIAN CELLS BENEFIT from a healthy dose of iron. In addition to its prominent role as the oxygen-carrying moiety in hemoglobin, iron is a cofactor for cytochromes and a variety of enzymes. During the past decade, a great deal has been learned about cellular iron transport and its regulation (1), but the understanding of iron balance within cells remains limited. Li et al. (Ref. 3; see p...

Binding of iron regulatory proteins (IRPs) to IREs located in proximity to the cap structure of ferritin H- and L-chain mRNAs blocks ferritin synthesis by preventing the recruitment of the small ribosomal subunit to the mRNA. We have devised a novel procedure to examine the assembly of translation initiation factors (eIFs) on regulated mRNAs. Unexpectedly, we find that the cap binding complex e...

Intracellular iron regulates gene expression by inhibiting the interaction of iron regulatory proteins (IRPs) with RNA motifs called iron-responsive elements (IREs). To assay this interaction in living cells we have developed two fluorescent IRE-based reporters that rapidly, reversibly, and specifically respond to changes in cellular iron status as well as signaling that modifies IRP activity. ...