Spectroscopic studies of acid-resistant residues of carbonaceous chondrites

Mass and IR spectra have been obtained of the acid-resistant residues resulting from HCl and HF treatments of ALH-77307 (C3). ^C NMR spectra of the residues obtained by partial mineral dissolution with acid treatments of Yamato-791717 (C3) and Allende (C3) have been recorded under CP-MAS conditions. These spectral data were compatible with the polycyclic aromatic structure proposed for the major carbonaceous matter in carbonaceous chondrites by the authors

Optical Properties of Chiral Three-Dimensional Photonic Crystals made from Semiconductors

We perform a theoretical and numerical study of the optical properties of both direct and inverse three-dimensional (3D) chiral woodpile structures, and a corresponding chiral Bragg stack. We compute transmission spectra in the helical direction for finite crystals, and photonic band structures, where we ensure the effective index of all structures to be the same. We find that both 3D structures show dual-band circular dichroism, where light with a particular circular polarization state - either left- or right-handed - reveals a broad stop band with major attenuation, whereas the other polarization state is transmitted nearly unimpeded. We observe such gaps in different frequency ranges, with alternating handedness. The appearance of the circular-polarized gaps is successfully interpreted with a physical model wherein the circular polarization either co-rotates or counter-rotates with the chiral structure, thereby effectively leading to a spatially-dependent or a constant refractive index, and thus to the presence or absence of a gap. We find that the presence or absence of circularly polarized gaps is tuned by the transverse periods perpendicular to the chiral axis in both the 3D direct and inverse chiral woodpile crystal structures. The tunability of circular dichroism may find applications as on-chip sensors for circularly polarized light and in the on-chip detection of chiral molecules.Comment: 10 pages, 9 figure

Soluble LR11/SorLA represses thermogenesis in adipose tissue and correlates with BMI in humans.

Thermogenesis in brown adipose tissue (BAT) is an important component of energy expenditure in mammals. Recent studies have confirmed its presence and metabolic role in humans. Defining the physiological regulation of BAT is therefore of great importance for developing strategies to treat metabolic diseases. Here we show that the soluble form of the low-density lipoprotein receptor relative, LR11/SorLA (sLR11), suppresses thermogenesis in adipose tissue in a cell-autonomous manner. Mice lacking LR11 are protected from diet-induced obesity associated with an increased browning of white adipose tissue and hypermetabolism. Treatment of adipocytes with sLR11 inhibits thermogenesis via the bone morphogenetic protein/TGFβ signalling pathway and reduces Smad phosphorylation. In addition, sLR11 levels in humans are shown to positively correlate with body mass index and adiposity. Given the need for tight regulation of a tissue with a high capacity for energy wastage, we propose that LR11 plays an energy conserving role that is exaggerated in states of obesity.AW and AVP were supported by FP7 – BetaBAT, BBSRC (BB/J009865/1), the British Heart Foundation (PG/12/53/29714) and MDU MRC. MJ and HB were supported by Japan Health and Labour Sciences Research grant (H22-rinkensui-ippan-001) and Grants-in–aid for Scientific Research from Japanese Ministry of Education, Culture, Sports, Science and Technology (24390231 and 24790907). VP was supported by Wellcome Trust and the Cambridge Overseas Trust. JR was supported by Ministerio de Educación, through “Programa Nacional de Movilidad de Recursos Humanos del Plan Nacional de I-D+i 2008-2011 (Subprograma de Estancias de Movilidad en el Extranjero “José Castillejo” para jóvenes Doctores, ref: JC2011-0248). SV was supported by MRC. WJS was supported by the Austrian Science Fund (FWF P-20218 and P-20455). Animal work was performed at the MDU DMC Core facilities.This is the final version of the article. It first appeared from NPG via http://dx.doi.org/10.1038/ncomms995

Soluble LR11/SorLA represses thermogenesis in adipose tissue and correlates with BMI in humans

Thermogenesis in brown adipose tissue (BAT) is an important component of energy expenditure in mammals. Recent studies have confirmed its presence and metabolic role in humans. Defining the physiological regulation of BAT is therefore of great importance for developing strategies to treat metabolic diseases. Here we show that the soluble form of the low-density lipoprotein receptor relative, LR11/SorLA (sLR11), suppresses thermogenesis in adipose tissue in a cell-autonomous manner. Mice lacking LR11 are protected from diet-induced obesity associated with an increased browning of white adipose tissue and hypermetabolism. Treatment of adipocytes with sLR11 inhibits thermogenesis via the bone morphogenetic protein/TGFb signalling pathway and reduces Smad phosphorylation. In addition, sLR11 levels in humans are shown to positively correlate with body mass index and adiposity. Given the need for tight regulation of a tissue with a high capacity for energy wastage, we propose that LR11 plays an energy conserving role that is exaggerated in states of obesity

Missing western half of the Pacific Plate: Geochemical nature of the Izanagi-Pacific Ridge interaction with a stationary boundary between the Indian and Pacific mantles

The source mantle of the basaltic ocean crust on the western half of the Pacific Plate was examined using Pb–Nd–Hf isotopes. The results showed that the subducted Izanagi–Pacific Ridge (IPR) formed from both Pacific (180–∼80 Ma) and Indian (∼80–70 Ma) mantles. The western Pacific Plate becomes younger westward and is thought to have formed from the IPR. The ridge was subducted along the Kurile–Japan–Nankai–Ryukyu (KJNR) Trench at 60–55 Ma and leading edge of the Pacific Plate is currently stagnated in the mantle transition zone. Conversely, the entire eastern half of the Pacific Plate, formed from isotopically distinct Pacific mantle along the East Pacific Rise and the Juan de Fuca Ridge, largely remains on the seafloor. The subducted IPR is inaccessible; therefore, questions regarding which mantle might be responsible for the formation of the western half of the Pacific Plate remain controversial. Knowing the source of the IPR basalts provides insight into the Indian–Pacific mantle boundary before the Cenozoic. Isotopic compositions of the basalts from borehole cores (165–130 Ma) in the western Pacific show that the surface oceanic crust is of Pacific mantle origin. However, the accreted ocean floor basalts (∼80–70 Ma) in the accretionary prism along the KJNR Trench have Indian mantle signatures. This indicates the younger western Pacific Plate of IPR origin formed partly from Indian mantle and that the Indian–Pacific mantle boundary has been stationary in the western Pacific at least since the Cretaceous

Pyrolytic studies of carbonaceous matter in Antarctic carbonaceous chondrites

Pyrolysis products of the major carbonaceous matter in six Antarctic carbonaceous chondrites, Y-74662 (C2), Y-791198 (C2), Y-793321 (C2), B-7904 (C2), Y-791717 (C3), and ALH-77307 (C3), have been examined by GC-FID and GC-MS. There is apparently a similarity in the structure of all samples. Many sulfur-containing compounds have been detected as major products in pyrolysis of the residues which were obtained by partial mineral dissolution of Y-791717 and ALH-77307 with concentrated hydrochloric acid

Pyrolytic studies of organic components in Antarctic carbonaceous chondrites Y-74662 and ALH-77307

The organic components of two Antarctic carbonaceous chondrites, Y-74662 (C2) and ALH-77307 (C3), have been investigated by pyrolysis using a Curie point pyrolyzer equipped with GC or GC-MS. Although a number of aromatic compounds have been detected as the pyrolysis products of Y-74662 along with a small amount of n-alkanes, only a few aromatic compounds in small quantities and no n-alkane have been detected in the components produced on the pyrolysis of ALH-77307