Timing of closure of the Mesozoic-Tethys Ocean: Constraints from remnants of a 141-135 ocean island within the Bangong-Nujiang suture zone, Tibetan Plateau

Knowledge of the timing of the closure of the Meso-Tethys Ocean as represented by the Bangong–Nujiang Suture Zone, i.e., the timing of the Lhasa-Qiangtang collision, is critical for understanding the Mesozoic tectonics of the Tibetan Plateau. But this timing is hotly debated; existing suggestions vary from the Middle Jurassic (ca. 166 Ma) to Late Cretaceous (ca. 100 Ma). In this study, we describe the petrology of the Zhonggang igneous–sedimentary rocks in the middle segment of the Bangong–Nujiang Suture Zone and present results of zircon U–Pb geochronology, whole-rock geochemistry, and Sr–Nd isotope analysis of the Zhonggang igneous rocks. The Zhonggang igneous–sedimentary rocks have a thick basaltic basement (>2 km thick) covered by limestone with interbedded basalt and tuff, trachyandesite, chert, and poorly sorted conglomerate comprising limestone and basalt debris. There is an absence of terrigenous detritus (e.g., quartz) within the sedimentary and pyroclastic rocks. These observations, together with the typical exotic blocks-in-matrix structure between the Zhonggang igneous–sedimentary rocks and the surrounding flysch deposits, lead to the conclusion that the Zhonggang igneous–sedimentary rocks are remnants of an ocean island within the Meso-Tethys Ocean. This conclusion is consistent with the ocean island basalt-type geochemistry of the Zhonggang basalts and trachyandesites, which are enriched in light rare earth elements (LaN/YbN = 4.72–18.1 and 5.61–13.7, respectively) and have positive Nb–Ta anomalies (NbPM/ThPM > 1, TaPM/UPM > 1), low initial 87Sr/86Sr ratios (0.703992–0.705428), and positive mantle εNd(t) values (3.88–5.99). Zircon U–Pb dates indicate that the Zhonggang ocean island formed at 141–135 Ma; therefore, closure of the Meso-Tethys Ocean and collision of the Lhasa and Qiangtang terranes must have happened after ca. 135 Ma

Effect of DDGS manure on soil and plant: preliminary results of the greenhouse study

Non-Peer ReviewedThe use of dried distillers’ grains with solubles (DDGS) in feedlot cattle diets is increasing as the bio-ethanol industry expands. Manure derived from dried distiller’s grain with solubles (DDGS) fed cattle seem to have higher amounts of N and P than manure from regular grain fed cattle. This study investigates how DDGS manure affects soil fertility and nutrient uptake by barley grown in a controlled greenhouse environment. Both DDGS and regular manure were applied at 30, 60, 120 and 180 Mg ha-1 yr-1 to a sand soil. The results of the first 3 harvest cycles indicate that both types of manure resulted in similar increase in plant total P content. However, soil TP and available P concentrations in DDGS manure treatments were higher. Soil available in DDGS treatments was twice as much of that in regular manure. Increase in soil TN and available N contents was similar with both types of manure. Plant TN content did not seem to be influenced by manure application. This study indicates that the main concern with the use of DDGS manure is its high P solubility. However, no significant increase in soil available P was observed at a manure rate of 30 Mg ha-1 yr-1

Visualization experiments of a solid cylinder suspended by laminar flow

Acknowledgments The financial supports from the Fundamental Research Funds for the Central Universities (XK1802-1) is gratefully acknowledged.Peer reviewedPostprin

The 20-22 January 2007 Snow Events over Canada: Microphysical Properties

One of the grand challenges of the Global Precipitation Measurement (GPM) mission is to improve precipitation measurements in mid- and high-latitudes during cold seasons through the use of high-frequency passive microwave radiometry. Toward this end, the Weather Research and Forecasting (WRF) model with the Goddard microphysics scheme is coupled with a Satellite Data Simulation Unit (WRF-SDSU) that has been developed to facilitate over-land snowfall retrieval algorithms by providing a virtual cloud library and microwave brightness temperature (Tb) measurements consistent with the GPM Microwave Imager (GMI). This study tested the Goddard cloud microphysics scheme in WRF for snowstorm events (January 20-22, 2007) that took place over the Canadian CloudSAT/CALIPSO Validation Project (C3VP) ground site (Centre for Atmospheric Research Experiments - CARE) in Ontario, Canada. In this paper, the performance of the Goddard cloud microphysics scheme both with 2ice (ice and snow) and 3ice (ice, snow and graupel) as well as other WRF microphysics schemes will be presented. The results are compared with data from the Environment Canada (EC) King Radar, an operational C-band radar located near the CARE site. In addition, the WRF model output is used to drive the Goddard SDSU to calculate radiances and backscattering signals consistent with direct satellite observations for evaluating the model results

Observing Supermassive Black Holes across cosmic time: from phenomenology to physics

In the last decade, a combination of high sensitivity, high spatial resolution observations and of coordinated multi-wavelength surveys has revolutionized our view of extra-galactic black hole (BH) astrophysics. We now know that supermassive black holes reside in the nuclei of almost every galaxy, grow over cosmological times by accreting matter, interact and merge with each other, and in the process liberate enormous amounts of energy that influence dramatically the evolution of the surrounding gas and stars, providing a powerful self-regulatory mechanism for galaxy formation. The different energetic phenomena associated to growing black holes and Active Galactic Nuclei (AGN), their cosmological evolution and the observational techniques used to unveil them, are the subject of this chapter. In particular, I will focus my attention on the connection between the theory of high-energy astrophysical processes giving rise to the observed emission in AGN, the observable imprints they leave at different wavelengths, and the methods used to uncover them in a statistically robust way. I will show how such a combined effort of theorists and observers have led us to unveil most of the SMBH growth over a large fraction of the age of the Universe, but that nagging uncertainties remain, preventing us from fully understating the exact role of black holes in the complex process of galaxy and large-scale structure formation, assembly and evolution.Comment: 46 pages, 21 figures. This review article appears as a chapter in the book: "Astrophysical Black Holes", Haardt, F., Gorini, V., Moschella, U and Treves A. (Eds), 2015, Springer International Publishing AG, Cha

Evolution of regulatory signatures in primate cortical neurons at cell-type resolution

The human cerebral cortex contains many cell types that likely underwent independent functional changes during evolution. However, cell-type-specific regulatory landscapes in the cortex remain largely unexplored. Here we report epigenomic and transcriptomic analyses of the two main cortical neuronal subtypes, glutamatergic projection neurons and GABAergic interneurons, in human, chimpanzee, and rhesus macaque. Using genome-wide profiling of the H3K27ac histone modification, we identify neuron-subtype-specific regulatory elements that previously went undetected in bulk brain tissue samples. Human-specific regulatory changes are uncovered in multiple genes, including those associated with language, autism spectrum disorder, and drug addiction. We observe preferential evolutionary divergence in neuron subtype-specific regulatory elements and show that a substantial fraction of pan-neuronal regulatory elements undergoes subtype-specific evolutionary changes. This study sheds light on the interplay between regulatory evolution and cell-type-dependent gene-expression programs, and provides a resource for further exploration of human brain evolution and function

First-order formalism for dark energy and dust

This work deals with first-order formalism for dark energy and dust in standard cosmology, for models described by real scalar field in the presence of dust in spatially flat space. The field dynamics may be standard or tachyonic, and we show how the equations of motion can be solved by first-order differential equations. We investigate a model to illustrate how the dustlike matter may affect the cosmic evolution using this framework.Comment: 5 pages, 1 figure; title changed, new author included, discussions extended, references added, version to appear in EPJ

Limits on the production of scalar leptoquarks from Z (0) decays at LEP

A search has been made for pairs and for single production of scalar leptoquarks of the first and second generations using a data sample of 392000 Z0 decays from the DELPHI detector at LEP 1. No signal was found and limits on the leptoquark mass, production cross section and branching ratio were set. A mass limit at 95% confidence level of 45.5 GeV/c2 was obtained for leptoquark pair production. The search for the production of a single leptoquark probed the mass region above this limit and its results exclude first and second generation leptoquarks D0 with masses below 65 GeV/c2 and 73 GeV/c2 respectively, at 95% confidence level, assuming that the D0lq Yukawa coupling alpha(lambda) is equal to the electromagnetic one. An upper limit is also given on the coupling alpha(lambda) as a function of the leptoquark mass m(D0)