The P-T-t architecture of a Gondwanan suture: REE, U-Pb and Ti-in-zircon thermometric constraints from the Palghat Cauvery shear system, South India

Understanding the relationship between accessory mineral growth and the evolution of silicate mineral assemblages along the entirety of a P-T-t path is a critical step in developing models for evolving tectonic systems. Here we combine U–Pb age data (for zircon and monazite), rare earth element (REE) data and compositionally specific phase diagrams (P-T pseudosections) for the rocks of the Palghat Cauvery shear system (PCSS), Southern Indian order to constrain the periodicity of heating/cooling and burial/exhumation events during the Ediacaran/Cambrian amalgamation of Gondwana. HREE data from zircon are consistent with zircon grow that 672–724 °C during the breakdown of garnet in the kyanite stability field at 535.0 ± 4.9 Ma. This represents a cooling that punctuates the P-T-t path. Subsequent monazite growth and symplectite formation occurred at 920 °C and 7.5 kbar, 10 Ma after zircon growth which reflects a period of reheating and decompression related to delamination and the collapse of the East African orogen. The REE chemistry of the monazite is consistent with the system having undergone partial melting prior to monazite growth, thereby altering the bulk rock chemistry. The periodicity of the heating and cooling cycles (10 Ma) from this study is consistent with recently proposed tectonic switching models for the formation of granulite metamorphism in accretionary/collisional tectonic settings. The elevated heat flows required to generate the UHT metamorphism are achievable in the proposed back-arc setting for the PCSS during Gondwana amalgamation.Chris Clark, Alan S. Collins, M. Santosh, Richard Taylor and Benjamin P. Wad

Two-Photon Fluorescence Spectroscopy and Imaging of 4-Dimethylaminonaphthalimide Peptide and Protein Conjugates

We report detailed photophysical studies on the two-photon fluorescence processes of the solvatochromic fluorophore 4-DMN as a conjugate of the calmodulin (CaM) and the associated CaM-binding peptide M13. Strong two-photon fluorescence enhancement has been observed which is associated with calcium binding. It is found that the two-photon absorption cross-section is strongly dependent on the local environment surrounding the 4-DMN fluorophore in the CaM conjugates, providing sensitivity between sites of fluorophore attachment. Utilizing time-resolved measurements, the emission dynamics of 4-DMN under various environmental (solvent) conditions are analyzed. In addition, anisotropy measurements reveal that the 4-DMN–S38C–CaM system has restricted rotation in the calcium-bound calmodulin. To establish the utility for cellular imaging, two-photon fluorescence microscopy studies were also carried out with the 4-DMN-modified M13 peptide in cells. Together, these studies provide strong evidence that 4-DMN is a useful probe in two-photon imaging, with advantageous properties for cellular experiments.German Science Foundation (SO 1100/1-1

Requirement for PCNA in DNA Mismatch Repair at a Step Preceding DNA Resynthesis

Abstractid system was used to screen yeast and human expression libraries for proteins that interact with mismatch repair proteins. PCNA was recovered from both libraries and shown in the case of yeast to interact with both MLH1 and MSH2. A yeast strain containing a mutation in the PCNA gene had a strongly elevated mutation rate in a dinucleotide repeat, and the rate was not further elevated in a strain also containing a mutation in MLH1. Mismatch repair activity was examined in human cell extracts using an assay that does not require DNA repair synthesis. Activity was inhibited by p21 WAF1 or a p21 peptide, both of which bind to PCNA, and activity was restored to inhibited reactions by addition of PCNA. The data suggest a PCNA requirement in mismatch repair at a step preceding DNA resynthesis. The ability of PCNA to bind to MLH1 and MSH2 may reflect linkage between mismatch repair and replication and may be relevant to the roles of mismatch repair proteins in other DNA transactions

Ecosystem carbon 7 dioxide fluxes after disturbance in forests of North America

Disturbances are important for renewal of North American forests. Here we summarize more than 180 site years of eddy covariance measurements of carbon dioxide flux made at forest chronosequences in North America. The disturbances included stand-replacing fire (Alaska, Arizona, Manitoba, and Saskatchewan) and harvest (British Columbia, Florida, New Brunswick, Oregon, Quebec, Saskatchewan, and Wisconsin) events, insect infestations (gypsy moth, forest tent caterpillar, and mountain pine beetle), Hurricane Wilma, and silvicultural thinning (Arizona, California, and New Brunswick). Net ecosystem production (NEP) showed a carbon loss from all ecosystems following a stand-replacing disturbance, becoming a carbon sink by 20 years for all ecosystems and by 10 years for most. Maximum carbon losses following disturbance (g C m−2y−1) ranged from 1270 in Florida to 200 in boreal ecosystems. Similarly, for forests less than 100 years old, maximum uptake (g C m−2y−1) was 1180 in Florida mangroves and 210 in boreal ecosystems. More temperate forests had intermediate fluxes. Boreal ecosystems were relatively time invariant after 20 years, whereas western ecosystems tended to increase in carbon gain over time. This was driven mostly by gross photosynthetic production (GPP) because total ecosystem respiration (ER) and heterotrophic respiration were relatively invariant with age. GPP/ER was as low as 0.2 immediately following stand-replacing disturbance reaching a constant value of 1.2 after 20 years. NEP following insect defoliations and silvicultural thinning showed lesser changes than stand-replacing events, with decreases in the year of disturbance followed by rapid recovery. NEP decreased in a mangrove ecosystem following Hurricane Wilma because of a decrease in GPP and an increase in ER

Mechanical properties of magnetostrictive iron-gallium alloys

Single crystal specimens of Fe-17 at. % Ga were tested in tension at room temperature. Specimens with a tensile axis orientation of [110] displayed slip lines on the specimen faces corresponding to slip on the {110}with a critical resolved shear stress of 220 MPa. Yielding began at 0.3% elongation and 450 MPa. An ultimate tensile strength of 580 MPa was observed with no fracture occurring through 1.6% elongation. The Young s modulus was 160 GPa in the loading direction with a Poisson s ratio of -0.37 on the (100) major face. A specimen with a tensile axis orientation of [100] showed slip lines corresponding to slip on the {211}with critical resolved shear stress of 240 MPa. Discontinuous yielding began at 0.8% elongation, which was thought to result from twinning, kink band formation, or stress-induced transformation. The Young\u27s modulus was 65 GPa in the loading direction with a Poisson s ratio of 0.45 on the (001) major face. A maximum tensile strength of 515 MPa was observed with fracture occurring after 2% elongation. A sizeable elastic anisotropy of 19.9 was identified for Fe-27.2 at. % Ga accompanied by a Poisson\u27s ratio of -0.75 to produce a large in-plane auxetic behavior

Liver ‘organ on a chip’

© 2017 The liver plays critical roles in both homeostasis and pathology. It is the major site of drug metabolism in the body and, as such, a common target for drug-induced toxicity and is susceptible to a wide range of diseases. In contrast to other solid organs, the liver possesses the unique ability to regenerate. The physiological importance and plasticity of this organ make it a crucial system of study to better understand human physiology, disease, and response to exogenous compounds. These aspects have impelled many to develop liver tissue systems for study in isolation outside the body. Herein, we discuss these biologically engineered organoids and microphysiological systems. Keywords: Microphysiologic systems; Organoids; 3D culture systemsNational Institutes of Health (U.S.) (Grant UH3TR000496)National Institutes of Health (U.S.) (Grant UH3TR000503

Outcomes of specialist discharge coordination and intermediate care schemes for patients who are homeless: analysis protocol for a population-based historical cohort

Introduction People who are homeless often experience poor hospital discharge arrangements, reflecting ongoing care and housing needs. Specialist integrated homeless health and care provision (SIHHC) schemes have been developed and implemented to facilitate the safe and timely discharge of homeless patients from hospital. Our study aims to investigate the health outcomes of patients who were homeless and seen by a selection of SIHHC services. Methods and analysis Our study will employ a historical population-based cohort in England. We will examine health outcomes among three groups of adults: (1) homeless patients seen by specialist discharge schemes during their hospital admission; (2) homeless patients not seen by a specialist scheme and (3)admitted patients who live in deprived neighbourhoods and were not recorded as being homeless. Primary outcomes will be: time from discharge to next hospital inpatient admission; time from discharge to next accident and emergency attendance and 28-day emergency readmission. Outcome data will be generated through linkage to hospital admissions data (Hospital Episode Statistics) and mortality data for November 2013 to November 2016. Multivariable regression will be used to model the relationship between the study comparison groups and each of the outcomes. Ethics and dissemination Approval has been obtained from the National Health Service (NHS) Confidentiality Advisory Group (reference 16/CAG/0021) to undertake this work using unconsented identifiable data. Health Research Authority Research Ethics approval (REC 16/EE/0018) has been obtained in addition to local research and development approvals for data collection at NHS sites. We will feedback the results of our study to our advisory group of people who have lived experience of homelessness and seek their suggestions on ways to improve or take this work further for their benefit. We will disseminate our findings to SIHHC schemes through a series of regional workshops

Beta-delayed-neutron studies of 135,136^{135,136}Sb and 140^{140}I performed with trapped ions

Beta-delayed-neutron ($\beta$n) spectroscopy was performed using the Beta-decay Paul Trap and an array of radiation detectors. The $\beta$n branching ratios and energy spectra for $^{135,136}$Sb and $^{140}$I were obtained by measuring the time of flight of recoil ions emerging from the trapped ion cloud. These nuclei are located at the edge of an isotopic region identified as having $\beta$n branching ratios that impact the r-process abundance pattern around the A~130 peak. For $^{135,136}$Sb and $^{140}$I, $\beta$n branching ratios of 14.6(11)%, 17.6(28)%, and 7.6(28)% were determined, respectively. The $\beta$n energy spectra obtained for $^{135}$Sb and $^{140}$I are compared with results from direct neutron measurements, and the $\beta$n energy spectrum for $^{136}$Sb has been measured for the first time

Quasi-Periodic Occultation by a Precessing Accretion Disk and Other Variabilities of SMC X-1

We have investigated the variability of the binary X-ray pulsar, SMC X-1, in data from several X-ray observatories. We confirm the ~60-day cyclic variation of the X-ray flux in the long-term monitoring data from the RXTE and CGRO observatories. X-ray light curves and spectra from the ROSAT, Ginga, and ASCA observatories show that the uneclipsed flux varies by as much as a factor of twenty between a high-flux state when 0.71 second pulses are present and a low-flux state when pulses are absent. In contrast, during eclipses when the X-rays consist of radiation scattered from circumsource matter, the fluxes and spectra in the high and low states are approximately the same. These observations prove that the low state of SMC X-1 is not caused by a reduction in the intrinsic luminosity of the source, or a spectral redistribution thereof, but rather by a quasi-periodic blockage of the line of sight, most likely by a precessing tilted accretion disk. In each of two observations in the midst of low states a brief increase in the X-ray flux and reappearance of 0.71 second pulses occurred near orbital phase 0.2. These brief increases result from an opening of the line of sight to the pulsar that may be caused by wobble in the precessing accretion disk. The records of spin up of the neutron star and decay of the binary orbit are extended during 1991-1996 by pulse-timing analysis of ROSAT, ASCA, and RXTE PCA data. The pulse profiles in various energy ranges from 0.1 to >21 keV are well represented as a combination of a pencil beam and a fan beam. Finally, there is a marked difference between the power spectra of random fluctuations in the high-state data from the RXTE PCA below and above 3.4 keV. Deviation from the fitted power law around 0.06 Hz may be QPO.Comment: Accepted to ApJ. 33 pages including 11 figure