The cell cycle–apoptosis connection revisited in the adult brain

Adult neurogenesis is studied in vivo using thymidine analogues such as bromodeoxyuridine (BrdU) to label DNA synthesis during the S phase of the cell cycle. However, BrdU may also label DNA synthesis events not directly related to cell proliferation, such as DNA repair and/or abortive reentry into the cell cycle, which can occur as part of an apoptotic process in postmitotic neurons. In this study, we used three well-characterized models of injury-induced neuronal apoptosis and the combined visualization of cell birth (BrdU labeling) and death (Tdt-mediated dUTP-biotin nick end labeling) to investigate the specificity of BrdU incorporation in the adult mouse brain in vivo. We present evidence that BrdU is not significantly incorporated during DNA repair and that labeling is not detected in vulnerable or dying postmitotic neurons, even when a high dose of BrdU is directly infused into the brain. These findings have important implications for a controversy surrounding adult neurogenesis: the connection between cell cycle reactivation and apoptosis of terminally differentiated neurons

The Orientation of Unsymmetrical Molecules at Interfaces

A function giving the distribution of the angles of orientation of the molecular axes from the normal to the interface can be obtained if one makes use of a number of special assumptions regarding the forces of orientation. This is compared with the distribution calculated on assuming an extreme form of Langmuir's principle of independent surface action. The importance of having such a function is pointed out

On the role of ground state correlations in hypernuclear non-mesonic weak decay

The contribution of ground state correlations (GSC) to the non--mesonic weak decay of $^{12}_\Lambda$C and other medium to heavy hypernuclei is studied within a nuclear matter formalism implemented in a local density approximation. We adopt a weak transition potential including the exchange of the complete octets of pseudoscalar and vector mesons as well as a residual strong interaction modeled on the Bonn potential. Leading GSC contributions, at first order in the residual strong interaction, are introduced on the same footing for all isospin channels of one-- and two--nucleon induced decays. Together with fermion antisymmetrization, GSC turn out to be important for an accurate determination of the decay widths. Besides opening the two--nucleon stimulated decay channels, for $^{12}_\Lambda$C GSC are responsible for 14% of the rate $\Gamma_1$ while increasing the $\Gamma_{n}/\Gamma_{p}$ ratio by 4%. Our final results for $^{12}_\Lambda$C are: $\Gamma_{\rm NM}=0.98$, $\Gamma_{n}/\Gamma_{p}=0.34$ and $\Gamma_2/\Gamma_{\rm NM}=0.26$. The saturation property of $\Gamma_{\rm NM}$ with increasing hypernuclear mass number is clearly observed. The agreement with data of our predictions for $\Gamma_{\rm NM}$, $\Gamma_n/\Gamma_p$ and $\Gamma_2$ is rather good.Comment: 32 pages, 9 figure

Value Based Benchmarking and Market Partitioning

The paper offers an analytical approach for an integrated treatment of market partitioning and benchmarking within a Data Envelopment Analysis (DEA) framework. Based on an empirical example from the automotive industry we measure product effciency from the customer’s perspective. This is interpreted as customer value, i. e., as a ratio of outputs that customers obtain from a product (e. g., resale value, reliability) and inputs that customers have to invest (e. g., price, running costs). Products offering a maximum customer value relative to all other alternatives represent effcient peers, which constitute benchmarks for different sub-markets. All products benchmarked via the same effcient peer(s) constitute a sub-market including the benchmarks.Data Envelopment Analysis (DEA), Market Partitioning, Benchmarking, Product-Market Structuring, Customer Value

A Summary of the Bank of Canada Conference on Fixed-Income Markets, 3-4 May 2006

The Bank of Canada's interest in fixed-income markets spans several of its functional areas of responsibility, including monetary policy, funds management, and financial system stability and efficiency. For that reason, the 2006 conference brought together top academics and central bankers from around the world to discuss leading-edge work in the field of fixed-income research. The papers and discussions cover such topics as the efficiency of fixed-income markets, price formation, the determinants of the yield curve, and volatility modelling. This article provides a short summary of each conference paper and the ensuing discussion.