7,318 research outputs found
Chinas International Financing Strategies
In order to finance rapid economic growth in the 1990ās, Chinese companies tried different strategies for raising capital in international capital markets.Ā Ā The strategies ranged from the use of depository receipts to listings on major stock exchanges.Ā Ā The lessons learned from the experiences of the Chinese companies could be valuable for managers from many other countries seeking to raise capital in international capital markets and to investors seeking some foreign investments for their portfolios.Ā Ā In addition, there are many implications for researchers in international business and economics fields, such as: regulatory policies regarding overseas listings (registration procedures, foreign exchange control), initial public offering (IPO) processes for foreign companies, investment returns with and without international financing, efforts to narrow the differences between accounting standards, international investment banking and accounting services, and World Trade Organization (WTO) changes.Ā Ā While Chinese companies have been active in many capital markets, the focus of this study is upon the activities of Chinese companies in American capital markets
Cosmological Constraints from Galaxy Clustering and the Mass-to-Number Ratio of Galaxy Clusters
We place constraints on the average density (Omega_m) and clustering
amplitude (sigma_8) of matter using a combination of two measurements from the
Sloan Digital Sky Survey: the galaxy two-point correlation function, w_p, and
the mass-to-galaxy-number ratio within galaxy clusters, M/N, analogous to
cluster M/L ratios. Our w_p measurements are obtained from DR7 while the sample
of clusters is the maxBCG sample, with cluster masses derived from weak
gravitational lensing. We construct non-linear galaxy bias models using the
Halo Occupation Distribution (HOD) to fit both w_p and M/N for different
cosmological parameters. HOD models that match the same two-point clustering
predict different numbers of galaxies in massive halos when Omega_m or sigma_8
is varied, thereby breaking the degeneracy between cosmology and bias. We
demonstrate that this technique yields constraints that are consistent and
competitive with current results from cluster abundance studies, even though
this technique does not use abundance information. Using w_p and M/N alone, we
find Omega_m^0.5*sigma_8=0.465+/-0.026, with individual constraints of
Omega_m=0.29+/-0.03 and sigma_8=0.85+/-0.06. Combined with current CMB data,
these constraints are Omega_m=0.290+/-0.016 and sigma_8=0.826+/-0.020. All
errors are 1-sigma. The systematic uncertainties that the M/N technique are
most sensitive to are the amplitude of the bias function of dark matter halos
and the possibility of redshift evolution between the SDSS Main sample and the
maxBCG sample. Our derived constraints are insensitive to the current level of
uncertainties in the halo mass function and in the mass-richness relation of
clusters and its scatter, making the M/N technique complementary to cluster
abundances as a method for constraining cosmology with future galaxy surveys.Comment: 23 pages, submitted to Ap
Realizing the Nishimori transition across the error threshold for constant-depth quantum circuits
Preparing quantum states across many qubits is necessary to unlock the full
potential of quantum computers. However, a key challenge is to realize
efficient preparation protocols which are stable to noise and gate
imperfections. Here, using a measurement-based protocol on a 127
superconducting qubit device, we study the generation of the simplest
long-range order -- Ising order, familiar from Greenberger-Horne-Zeilinger
(GHZ) states and the repetition code -- on 54 system qubits. Our efficient
implementation of the constant-depth protocol and classical decoder shows
higher fidelities for GHZ states compared to size-dependent, unitary protocols.
By experimentally tuning coherent and incoherent error rates, we demonstrate
stability of this decoded long-range order in two spatial dimensions, up to a
critical point which corresponds to a transition belonging to the unusual
Nishimori universality class. Although in classical systems Nishimori physics
requires fine-tuning multiple parameters, here it arises as a direct result of
the Born rule for measurement probabilities -- locking the effective
temperature and disorder driving this transition. Our study exemplifies how
measurement-based state preparation can be meaningfully explored on quantum
processors beyond a hundred qubits.Comment: 16 pages, 18 figure
Wholeācell biocatalysis platform for gramāscale oxidative dearomatization of phenols
Technologies enabling new enzyme discovery and efficient protein engineering have spurred intense interest in the development of biocatalytic reactions. In recent years, wholeācell biocatalysis has received attention as a simple, efficient, and scalable biocatalytic reaction platform. Inspired by these developments, we have established a wholeācell protocol for oxidative dearomatization of phenols using the flavinādependent monooxygenase, TropB. This approach provides a scalable biocatalytic platform for accessing gramāscale quantities of chiral synthetic building blocks.The development of scalable and economical biocatalytic reaction platforms is critical for the application of biocatalysis in synthetic chemistry. Therefore, we have established a wholeācell method for the oxidative dearomatization of phenols using the flavinādependent monooxygenase, TropB. In comparison with reactions using isolated enzyme, our wholeācell method allowed us to perform tenfold more reactions per liter of cell culture, without loss of siteā or stereoselectivity.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/150545/1/cbdd13443.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/150545/2/cbdd13443_am.pd
Recommendations on Collecting and Storing Samples for Genetic Studies in Hearing and Tinnitus Research.
Objectives: Research on the genetic basis of tinnitus is still in its first steps. A group of scientists dedicated to tinnitus genetics within European Tinnitus Network (TINNET) network recognize that further progress requires multicenter collaborative efforts for defining contributing genes. The purpose of the present work is to provide instructions regarding collection, processing, storage, and shipment of samples intended for genetic studies in auditory research. Design: One part of the recommendations has a general character; another part is of particular importance for auditory healthcare practitioners such as otolaryngology physicians, audiologists, and general practitioners. Results: We provide a set of instructions and various options for obtaining samples. We give advice regarding sample processing, storage, and shipment and define the minimal and essential clinical information that should accompany the samples collected for genetic processing. Conclusions: These recommendations offer a basis to standardize and optimize collaborations between geneticists and healthcare practitioners specialized in tinnitus and hearing disorders.info:eu-repo/semantics/publishedVersio
Dying neurons in thalamus of asphyxiated term newborns and rats are autophagic.
OBJECTIVE: Neonatal hypoxic-ischemic encephalopathy (HIE) still carries a high burden by its mortality and long-term neurological morbidity in survivors. Apart from hypothermia, there is no acknowledged therapy for HIE, reflecting the lack of mechanistic understanding of its pathophysiology. (Macro)autophagy, a physiological intracellular process of lysosomal degradation, has been proposed to be excessively activated in excitotoxic conditions such as HIE. The present study examines whether neuronal autophagy in the thalamus of asphyxiated human newborns or P7 rats is enhanced and related to neuronal death processes.
METHODS: Neuronal autophagy and cell death were evaluated in the thalamus (frequently injured in severe HIE) of both human newborns who died after severe HIE (nā=ā5) and P7 hypoxic-ischemic rats (Rice-Vannuci model). Autophagic (LC3, p62), lysosomal (LAMP1, cathepsins), and cell death (TUNEL, caspase-3) markers were studied by immunohistochemistry in human and rat brain sections, and by additional methods in rats (immunoblotting, histochemistry, and electron microscopy).
RESULTS: Following severe perinatal asphyxia in both humans and rats, thalamic neurons displayed up to 10-fold (pā<ā0.001) higher numbers of autophagosomes and lysosomes, implying an enhanced autophagic flux. The highly autophagic neurons presented strong features of apoptosis. These findings were confirmed and elucidated in more detail in rats.
INTERPRETATION: These results show for the first time that autophagy is enhanced in severe HIE in dying thalamic neurons of human newborns, as in rats. Experimental neuroprotective strategies targeting autophagy could thus be a promising lead to follow for the development of future therapeutic approaches. Ann Neurol 2014;76:695-711
Scope and Mechanistic Study of the Coupling Reaction of Ī±,Ī²-Unsaturated Carbonyl Compounds with Alkenes: Uncovering Electronic Effects on Alkene Insertion vs Oxidative Coupling Pathways
The cationic ruthenium-hydride complex [(C6H6)(PCy3)(CO)RuH]+BF4ā (1) was found to be a highly effective catalyst for the intermolecular conjugate addition of simple alkenes to Ī±,Ī²-unsaturated carbonyl compounds to give (Z)-selective tetrasubstituted olefin products. The analogous coupling reaction of cinnamides with electron-deficient olefins led to the oxidative coupling of two olefinic CāH bonds in forming (E)-selective diene products. The intramolecular version of the coupling reaction efficiently produced indene and bicyclic fulvene derivatives. The empirical rate law for the coupling reaction of ethyl cinnamate with propene was determined as follows: rate = k[1]1[propene]0[cinnamate]ā1. A negligible deuterium kinetic isotope effect (kH/kD = 1.1 Ā± 0.1) was measured from both (E)-C6H5CHāC(CH3)CONHCH3 and (E)-C6H5CDāC(CH3)CONHCH3 with styrene. In contrast, a significant normal isotope effect (kH/kD = 1.7 Ā± 0.1) was observed from the reaction of (E)-C6H5CHāC(CH3)CONHCH3 with styrene and styrene-d8. A pronounced carbon isotope effect was measured from the coupling reaction of (E)-C6H5CHāCHCO2Et with propene (13C(recovered)/13C(virgin) at CĪ² = 1.019(6)), while a negligible carbon isotope effect (13C(recovered)/13C(virgin) at CĪ² = 0.999(4)) was obtained from the reaction of (E)-C6H5CHāC(CH3)CONHCH3 with styrene. Hammett plots from the correlation of para-substituted p-X-C6H4CHāCHCO2Et (X = OCH3, CH3, H, F, Cl, CO2Me, CF3) with propene and from the treatment of (E)-C6H5CHāCHCO2Et with a series of para-substituted styrenes p-Y-C6H4CHāCH2 (Y = OCH3, CH3, H, F, Cl, CF3) gave the positive slopes for both cases (Ļ = +1.1 Ā± 0.1 and +1.5 Ā± 0.1, respectively). Eyring analysis of the coupling reaction led to the thermodynamic parameters, ĪHā§§ = 20 Ā± 2 kcal molā1 and ĪSā§§ = ā42 Ā± 5 eu. Two separate mechanistic pathways for the coupling reaction have been proposed on the basis of these kinetic and spectroscopic studies
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