The Spectrum of Volterra-type integration operators on generalized Fock spaces

We describe the spectrum of certain integration operators acting on general- ized Fock spaces

Chemical vapor deposition of iron, iron carbides, and iron nitride films from amidinate precursors

Iron bis(N,N-diisopropylacetamidinate) [Fe2(µ-iPr-MeAMD)2(2-iPr-MeAMD)2] and iron bis(N,N-di-tert-butylacetamidinate) [Fe(tBu-MeAMD)2] were used as precursors for the metallorganic chemical vapor deposition (MOCVD) of iron-containing compounds including pure iron, iron carbides, Fe3C and Fe4C, and iron nitrides Fe4C. Their decomposition mechanism involves hydrogen migration followed by dissociation of the Fe–N bond and the release of free hydrogenated ligand (HL) and radicals. Surface intermediates are either released or decomposed on the surface providing Fe–N or Fe–C bonds. MOCVD experiments were run at 10 Torr, in the temperature ranges of 350–450°C with Fe2(µ−iPr-MeAMD)2(2-iPr-MeAMD)2 and 280–350°C with Fe(tBu-MeAMD)2. Films prepared from Fe2(µ−iPr-MeAMD)2(2-iPr-MeAMD)2 contain Fe, Fe3C, and Fe4C. Those prepared from Fe(tBu-MeAMD)2 contain Fe, Fe3C, and also Fe4C or Fe4N, depending on the temperature and hydrogen to precursor ratio (H/P) in the input gas. The room-temperature coercive field of films processed from Fe(tBu-MeAMD)2 is 3 times higher than that of the high temperature processed Fe4N films

Characterization of laser-driven single and double electron bunches with a permanent magnet quadrupole triplet and pepper-pot mask

Electron beams from laser-plasma wakefield accelerators have low transverse emittance, comparable to those from conventional radio frequency accelerators, which highlights their potential for applications, many of which will require the use of quadrupole magnets for optimal electron beam transport. We report on characterizing electron bunches where double bunches are observed under certain conditions. In particular, we present pepper-pot measurements of the transverse emittance of 120-200 MeV laser wakefield electron bunches after propagation through a triplet of permanent quadrupole magnets. It is shown that the normalized emittance at source can be as low as 1 π mm mrad (resolution limited), growing by about five times after propagation through the quadrupoles due to beam energy spread. The inherent energy-dependence of the magnets also enables detection of double electron bunches that could otherwise remain unresolved, providing insight into the self-injection of multiple bunches. The combination of quadrupoles and pepper-pot, in addition, acts as a diagnostic for the alignment of the magnetic triplet

Parent-of-origin-specific allelic associations among 106 genomic loci for age at menarche.

Age at menarche is a marker of timing of puberty in females. It varies widely between individuals, is a heritable trait and is associated with risks for obesity, type 2 diabetes, cardiovascular disease, breast cancer and all-cause mortality. Studies of rare human disorders of puberty and animal models point to a complex hypothalamic-pituitary-hormonal regulation, but the mechanisms that determine pubertal timing and underlie its links to disease risk remain unclear. Here, using genome-wide and custom-genotyping arrays in up to 182,416 women of European descent from 57 studies, we found robust evidence (P < 5 × 10(-8)) for 123 signals at 106 genomic loci associated with age at menarche. Many loci were associated with other pubertal traits in both sexes, and there was substantial overlap with genes implicated in body mass index and various diseases, including rare disorders of puberty. Menarche signals were enriched in imprinted regions, with three loci (DLK1-WDR25, MKRN3-MAGEL2 and KCNK9) demonstrating parent-of-origin-specific associations concordant with known parental expression patterns. Pathway analyses implicated nuclear hormone receptors, particularly retinoic acid and γ-aminobutyric acid-B2 receptor signalling, among novel mechanisms that regulate pubertal timing in humans. Our findings suggest a genetic architecture involving at least hundreds of common variants in the coordinated timing of the pubertal transition