Human frataxin: iron and ferrochelatase binding surface

The coordinated iron structure and ferrochelatase binding surface of human frataxin have been characterized to provide insight into the protein's ability to serve as the iron chaperone during heme biosynthesis.     

Mechanism of glutaredoxin-ISU [2Fe-2S] cluster exchange

Exchange of [2Fe-2S] centers between Grx2 and the cluster scaffold protein ISU, and characterization of two mutually exclusive Grx2 binding sites on ISU by isothermal titration calorimetry supports a direct link for Grx and glutathione involvement in ISU promoted Fe-S cluster biosynthesis.     

Dynamics of photogenerated holes in nanocrystalline α-Fe2O3 electrodes for water oxidation probed by transient absorption spectroscopy

Transient absorption spectroscopy on the μs-s time scale is used to monitor the yield and decay dynamics of photogenerated holes in nanocrystalline hematite photoanodes. In the absence of a positive applied bias, these holes are observed to undergo rapid electron-hole recombination. The application of a positive bias results in the generation of long-lived (3 ± 1 s lifetime) photoholes.     

(TMTSF)2(2,5-Tcnqbr2): Structure and Physical Properties

The 2:1 charge-transfer salt (TMTSF)₂(2,5-TCNQBr2) has been prepared and its physical properties investigated. Its crystal structure consists of segregated stacks of TMTSF donors (ring-over-bond overlap pattern; mean interplanar spacing of 3.6A) and chains of edge-on and disordered 2,5-TCNQBr2 acceptors. Infrared data are suggestive of unit charge on the 2,5-TCNQBr2 molecule and, therefore, half charge on the TMTSF donor. Resistivity data are successfully interpreted on the basis of a percolation construction. Magnetic data are also presented.     

Recurrence Relationships for the Mean Number of Faces and Vertices for Random Convex Hulls

This paper studies the convex hull of n random points in R^d\mathsf{R}^{d} . A recently proved topological identity of the author is used in combination with identities of Efron and Buchta to find the expected number of vertices of the convex hull—yielding a new recurrence formula for all dimensions d. A recurrence for the expected number of facets and (d−2)-faces is also found, this analysis building on a technique of Rényi and Sulanke. Other relationships for the expected count of i-faces (1≤i<d) are found when d≤5, by applying the Dehn–Sommerville identities. A general recurrence identity (see (3) below) for this expected count is conjectured.     

Measurement of day and night neutrino energy spectra at SNO and constraints on neutrino mixing parameters

The Sudbury Neutrino Observatory (SNO) has measured day and night solar neutrino energy spectra and rates. For charged current events, assuming an undistorted 8B spectrum, the night minus day rate is 14.0%+/-6.3%(+1.5%)(-1.4%) of the average rate. If the total flux of active neutrinos is additionally constrained to have no asymmetry, the nu(e) asymmetry is found to be 7.0%+/-4.9%(+1.3%)(-1.2%). A global solar neutrino analysis in terms of matter-enhanced oscillations of two active flavors strongly favors the large mixing angle solution.