15 research outputs found

    Changes to the Fossil Record of Insects through Fifteen Years of Discovery

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    The first and last occurrences of hexapod families in the fossil record are compiled from publications up to end-2009. The major features of these data are compared with those of previous datasets (1993 and 1994). About a third of families (>400) are new to the fossil record since 1994, over half of the earlier, existing families have experienced changes in their known stratigraphic range and only about ten percent have unchanged ranges. Despite these significant additions to knowledge, the broad pattern of described richness through time remains similar, with described richness increasing steadily through geological history and a shift in dominant taxa, from Palaeoptera and Polyneoptera to Paraneoptera and Holometabola, after the Palaeozoic. However, after detrending, described richness is not well correlated with the earlier datasets, indicating significant changes in shorter-term patterns. There is reduced Palaeozoic richness, peaking at a different time, and a less pronounced Permian decline. A pronounced Triassic peak and decline is shown, and the plateau from the mid Early Cretaceous to the end of the period remains, albeit at substantially higher richness compared to earlier datasets. Origination and extinction rates are broadly similar to before, with a broad decline in both through time but episodic peaks, including end-Permian turnover. Origination more consistently exceeds extinction compared to previous datasets and exceptions are mainly in the Palaeozoic. These changes suggest that some inferences about causal mechanisms in insect macroevolution are likely to differ as well

    A note on arbitrage in term structure

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    Arbitrage, Term structure, Large financial markets, Kakutani theorem, Gaussian random variables, 91B28, 60G42, G10, G12,

    Cyclodextrin complexation improves aqueous solubility of the antiepileptic drug, rufinamide: solution and solid state characterization of compound-cyclodextrin binary systems

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    Rufinamide (RUF) was characterized in terms of cyclodextrin (CD) complexation in order to improve its aqueous solubility. Binary systems of RUF with three CDs—β-cyclodextrin (β-CD), randomly methylated-β-cyclodextrin (RAMEB) and sulfobutylether-β-cyclodextrin (SBE-β-CD)—were characterized with a wide variety of analytical techniques. Liquid state characterization was carried out by complementary techniques such as nuclear magnetic resonance spectroscopy (NMR), capillary electrophoresis (CE), mass spectrometry (MS) and phase solubility studies. The latter revealed that the stability of the complexes decreased in the order of RAMEB > β-CD > SBE-β-CD. AL-type diagrams were obtained in all cases, characteristic of 1:1 stoichiometry, with a maximum of over 15-fold increase in RUF solubility, when complexed with RAMEB. NMR Job plot and MS studies confirmed phase solubility results, regarding the binding stoichiometry. 1H NMR and 2D ROESY investigations revealed the inclusion of the triazole moiety of RUF, confirmed by molecular modeling. Solid state complexation in 1:1 molar ratio was carried out by kneading method and investigated by differential scanning calorimetry (DSC) and infrared spectroscopy (IR). Comparative dissolution studies indicated an over two-fold improvement in dissolution efficacy of the kneaded products, when compared to the pure drug. Results of the present study might pave the way for a drug formulation with improved bioavailability

    Forecasting Hungarian mortality rates using the Lee-Carter method

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    A modified version of the popular Lee-Carter method (Lee-Carter 1992) is applied to forecast mortality rates in Hungary for the period 2004-2040 on the basis of mortality data between 1949 and 2003 both for men and women. Another case is also considered based on a restricted data set corresponding to the period 1989-2003. The model fitted to the data of the period 1949-2003 forecasts increasing mortality rates for men between ages 45 and 55, pointing out that the Lee-Carter method is hardly applicable for countries where mortality rates exhibit trends as peculiar as in Hungary. However, models fitted to the data for the last 15 years both for men and women forecast decreasing trends similarly to the case of countries where the method was successfully applied. Hence one gets a better fit in this way, however, further concerns suggest that the Lee-Carter model, which is celebrated and widely used in actuarial practice, does not necessarily give sufficiently good prediction

    Economy and Ethnicity in Transylvania

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    This chapter discusses the most important social domain that is not organized along ethnic lines in Transylvania, namely the economy. The chapter aims to answer two general questions: First, to what extent is Romania’s democracy and economic institutional system able to capitalize on the potential assets stemming from ethnic diversity? Second, what kind of cultural, structural, and network resources do Transylvanian Hungarians possess, to what extent and how do they succeed in utilizing them in the economy? The main conclusion of the chapter is that the economic sector is not perceived as being ethnically divided in Transylvania; there are, however, a number of initiatives that may point toward an ethnically coordinated economic sector
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