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New Twist (new + twist)
Selected AbstractsACCUMULATING POSTZYGOTIC ISOLATION GENES IN PARAPATRY: A NEW TWIST ON CHROMOSOMAL SPECIATIONEVOLUTION, Issue 3 2003Arcadi Navarro Abstract Chromosomal rearrangements can promote reproductive isolation by reducing recombination along a large section of the genome. We model the effects of the genetic barrier to gene flow caused by a chromosomal rearrangement on the rate of accumulation of postzygotic isolation genes in parapatry. We find that, if reproductive isolation is produced by the accumulation in parapatry of sets of alleles compatible within but incompatible across species, chromosomal rearrangements are far more likely to favor it than classical genetic barriers without chromosomal changes. New evidence of the role of chromosomal rearrangements in parapatric speciation suggests that postzygotic isolation is often due to the accumulation of such incompatibilities. The model makes testable qualitative predictions about the genetic signature of speciation. [source] ChemInform Abstract: Synthesis of Enantiomerically Pure Ethylenediamines from Chiral Sulfinimines: A New Twist to the Strecker Reaction.CHEMINFORM, Issue 8 2002Stephane Mabic Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Subsidized Island Biogeography Hypothesis: another new twist on an old theoryECOLOGY LETTERS, Issue 4 2001W.B. Anderson We present a new hypothesis for predicting and describing patterns of species diversity on small islands and habitat fragments. We have modified the traditional island biogeography equilibrium theory to incorporate the influence of spatial subsidies from the surrounding matrix, which vary among islands and habitat fragments, on species diversities. The modification indicates three possible directions for the effects of spatial subsidies on diversity, which depend on where the focal community falls on the hypothesized unimodal curve of the productivity,diversity relationship. The idea is novel because no recent syntheses of productivity,diversity,area relationships examine the role of allochthonous resources on recipient communities' diversity patterns. [source] High mobility group box-1 recognition: The beginning of a RAGEless era?EMBO MOLECULAR MEDICINE, Issue 6 2010Filipe Branco-Madeira Abstract High mobility group box 1 (HMGB1) is a molecular alarm signal that triggers an immune response when released. It was assumed that the receptor for advanced glycation end-products (RAGE) would mediate the signal to the immune system. Recently pattern recognition receptors that are triggered by molecules of bacterial origin (the Toll-like receptor (TLR) family) were shown to also respond to HMGB1. Now two papers establish the TLR4,HMGB1 axis as proinflammatory, eventually leading to disparate conditions like seizures or skin cancer. These reports add a new twist to our understanding of the mode of action of the alarm signal HMGB1. [source] FREE CASH FLOW AND PUBLIC GOVERNANCE: THE CASE OF ALASKAJOURNAL OF APPLIED CORPORATE FINANCE, Issue 3 2000Dwight R. Lee In a widely cited 1986 article in the American Economic Review, Michael Jensen gave the concept of free cash flow (FCF) a new twist by redefining it as cash flow in excess of that required to fund all projects with positive net present values. Put another way, FCF represents funds available in the firm that managers may choose to hold as idle cash, return to shareholders, or invest in projects with returns below the firm's cost of capital. In redefining FCF in this way, Jensen converted FCF from a measure of economic income and value into a measure of corporate assets available for discretionary, and potentially value-destroying, use by firm managers. And, as he argued in his important article, managers in mature businesses with substantial free cash flow have a tendency to destroy value by plowing too much capital back into those businesses or, often worse, making ill-advised acquisitions in unrelated businesses. Several methods have been developed in financial markets and internal corporate governance systems to discourage managers from wasting FCF. Better monitoring by boards of directors, large ownership blocks, and properly aligned management compensation contracts are all parts of the solution. And the extraordinary increase in stock repurchases in recent years, invariably applauded by investors, is another illustration of the market's success in encouraging companies to address their free cash flow problems. But if the "FCF problem" of the private sector has attracted considerable attention from finance scholars, the problem is even more acute in the public sector, where FCF can be thought of as tax revenue in excess of what is required to finance well-defined and generally accepted levels of public services. Unlike the private sector, in the public sector there are neither measures nor mechanisms by which to monitor and constrain wasteful spending by elected officials. In this article, the authors attempt to measure the costs to taxpayers of government FCF using the case of Alaska, which since 1969 has received a huge windfall of tax revenue from North Slope oil leases. After examining the state's public finances from 1968 through 1993, the authors offer $25 billion as a conservative estimate of the social losses from Alaska's waste of free cash flow during that 25-year period. [source] Attacking Poverty and the ,post-Washington consensus'JOURNAL OF INTERNATIONAL DEVELOPMENT, Issue 3 2001Paul Mosley Has the increasingly pro-poor stance of the World Bank, as manifested in particular in its most recent World Development Report (WDR), caused it to abandon its traditionally free-market attitudes ? The answer is ,yes and no'. The pursuit of ,security' espoused by the WDR has forced the Bank to acknowledge widespread market failure in the provision of security, both social and financial; and this has caused the Bank to espouse some measures very inconsistent with the Washington consensus, such as international capital controls. On the other hand, the old agenda of rolling back the frontiers of the state remains, and is given a new twist in WDR 2000 by the revelation that the ,voices of the poor' are arrayed against bureaucratic abuses. Debate within the Bank has become much more open and transparent, and this has exposed long-persisting internal differences about what markets still need to be liberalized in what environments. Copyright © 2001 John Wiley & Sons, Ltd. [source] Topoisomerases of kinetoplastid parasites: why so fascinating?MOLECULAR MICROBIOLOGY, Issue 4 2006Benu Brata Das Summary DNA topoisomerases are the key enzymes involved in carrying out high precision DNA transactions inside the cells. However, they are detrimental to the cell when a wide variety of topoisomerase-targeted drugs generate cytotoxic lesions by trapping the enzymes in covalent complexes on the DNA. The discovery of unusual heterodimeric topoisomerase I in kinetoplastid family added a new twist in topoisomerase research related to evolution, functional conservation and their preferential sensitivity to Camptothecin. On the other hand, structural and mechanistic studies on kinetoplastid topoisomerase II delineate some distinguishing features that differentiate the parasitic enzyme from its prokaryotic and eukaryotic counterparts. This review summarizes the recent advances in research in kinetoplastid topoisomerases, their evolutionary significance and the death of the unicellular parasite Leishmania donovani induced by topoisomerase I inhibitor camptothecin. [source] Senescence and serration: a new twist to an old taleTHE JOURNAL OF PATHOLOGY, Issue 2 2006P Minoo Abstract Interest in the role of oncogene-induced senescence in tumorigenesis is mounting. Raf-associated senescence in cutaneous nevi has been advanced as an example of this process occurring in the context of a human tumour. In this model, conversion from a senescent nevus to a malignant melanoma is accompanied by loss of expression of p16. Serrated polyps of the colorectum may provide a further example of oncogene-induced senescence. BRAF and KRAS mutation may initiate different pathways of senescence-associated serrated neoplasia in the colorectum, the former linked to CpG island methylator phenotype (CIMP)-high (CIMP1) and microsatellite instability (MSI)-high status and the latter with CIMP-low (CIMP2) and MSI-low status. The role of methylation in both Raf- and Ras-associated pathways is to drive tumorigenesis by silencing pro-apoptotic and cell cycle inhibitory genes. Both pathways are associated with mutation of Ras-induced senescence 1 (RIS1), but the biological role of RIS1 requires further elucidation. Copyright © 2006 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. [source] Integrin structure: new twists and turns in dynamic cell adhesionIMMUNOLOGICAL REVIEWS, Issue Erratum 2002Article first published online: 15 DEC 200 First page of article [source] Oral mucosal dendritic cells and periodontitis: many sides of the same coin with new twistsPERIODONTOLOGY 2000, Issue 1 2007Christopher W. Cutler First page of article [source] | |||||||||||||