Matrix inequalities involving the Khatri-Rao product

summary:We extend three inequalities involving the Hadamard product in three ways. First, the results are extended to any partitioned blocks Hermitian matrices. Second, the Hadamard product is replaced by the Khatri-Rao product. Third, the necessary and sufficient conditions under which equalities occur are presented. Thereby, we generalize two inequalities involving the Khatri–Rao product

Towards Autonomy: Cost-effective Scheduling for Long-range Autonomous Valet Parking (LAVP)

Continuous and effective developments in Autonomous Vehicles (AVs) are happening on daily basis. Industries nowadays, are interested in introducing less costly and highly controllable AVs to public. Current so-called AVP solutions are still limited to a very short range (e.g., even only work at the entrance of car parks). This paper proposes a parking scheduling scheme for long-range AVP (LAVP) case, by considering mobility of Autonomous Vehicles (AVs), fuel consumption and journey time. In LAVP, Car Parks (CPs) are used to accommodate increasing numbers of AVs, and placed outside city center, in order to avoid traffic congestions and ensure road safety in public places. Furthermore, with positioning of reference points to guide user-centric long-term driving and drop-off/pick-up passengers, simulation results under the Helsinki city scenario shows the benefits of LAVP. The advantage of LAVP system is also reflected through both analysis and simulation

Amniotic fluid-derived mesenchymal stem cells as a novel therapeutic approach in the treatment of fulminant hepatic failure in rats

As a potential alternative treatment for terminal liver diseases, amniotic fluid derived mesenchymal stem cells (AFMSCs) have many advantages over other stem cells: avoiding much ethical controversy and decrease in both quantity and differentiation potential with age. However, the therapeutic role of AFMSC for fulminant hepatic failure (FHF) has not yet been clearly elucidated. Therefore, we investigated the reparation effects of transplanted AFMSCs in rats with FHF. AFMSCs were transplanted into injured liver via the portal vein in the rat FHF model. Therapeutic effect was evaluated after cell transfusion by histologic pathology, hepatic enzyme levels and animal survival. Cryostat sections were prepared and directly assessed for green fluorescent protein (GFP) expression and localization, and in vivo differentiation of AFMSC was confirmed by double-immunostaining analyses. Our results show that AFMSCs prevented liver failure and reduced mortality in rats with FHF. These animals also exhibited improved liver function and animals survival after injection with AFMSCs using GFP, we demonstrated that the engrafted cells and their progeny incorporated into injured livers and produced albumin. We found that AFMSCs transplantation modestly promoted the repair of FHF in rats. AFMSCs implanted in the injured liver may be a novel therapeutic approach in the treatment of FHF.Key words: Amniotic fluid-derived mesenchymal stem cells, fulminant hepatic failure, cell transplantation, treatment, hepatogenic differentiation

Spawning rings of exceptional points out of Dirac cones

The Dirac cone underlies many unique electronic properties of graphene and topological insulators, and its band structure--two conical bands touching at a single point--has also been realized for photons in waveguide arrays, atoms in optical lattices, and through accidental degeneracy. Deformations of the Dirac cone often reveal intriguing properties; an example is the quantum Hall effect, where a constant magnetic field breaks the Dirac cone into isolated Landau levels. A seemingly unrelated phenomenon is the exceptional point, also known as the parity-time symmetry breaking point, where two resonances coincide in both their positions and widths. Exceptional points lead to counter-intuitive phenomena such as loss-induced transparency, unidirectional transmission or reflection, and lasers with reversed pump dependence or single-mode operation. These two fields of research are in fact connected: here we discover the ability of a Dirac cone to evolve into a ring of exceptional points, which we call an "exceptional ring." We experimentally demonstrate this concept in a photonic crystal slab. Angle-resolved reflection measurements of the photonic crystal slab reveal that the peaks of reflectivity follow the conical band structure of a Dirac cone from accidental degeneracy, whereas the complex eigenvalues of the system are deformed into a two-dimensional flat band enclosed by an exceptional ring. This deformation arises from the dissimilar radiation rates of dipole and quadrupole resonances, which play a role analogous to the loss and gain in parity-time symmetric systems. Our results indicate that the radiation that exists in any open system can fundamentally alter its physical properties in ways previously expected only in the presence of material loss and gain

Temperature Dependence of Photoelectrical Properties of Single Selenium Nanowires

Influence of temperature on photoconductivity of single Se nanowires has been studied. Time response of photocurrent at both room temperature and low temperature suggests that the trap states play an important role in the photoelectrical process. Further investigations about light intensity dependence on photocurrent at different temperatures reveal that the trap states significantly affect the carrier generation and recombination. This work may be valuable for improving the device optoelectronic performances by understanding the photoelectrical properties

Preventive Effect of Crocin on Osteoporosis in an Ovariectomized Rat Model

The purpose of this study was to investigate the therapeutic effects of crocin on ovariectomy-induced osteoporosis in rats. Female Sprague-Dawley rats were randomly assigned to a sham-operated group (sham) and five ovariectomy (OVX) subgroups, that is, OVX with vehicle (OVX), OVX with 17β-estradiol (E2, 25 μg/kg/day), and OVX with graded crocin doses (5, 10, or 20 mg/kg/day). Daily oral administration of E2 or crocin started 4 weeks after OVX and lasted for 16 weeks. Our results showed that crocin dose-dependently inhibited the BMD reduction of L4 vertebrae and femurs caused by OVX and prevented the deterioration of trabecular microarchitecture, which were accompanied by a significant decrease in skeletal remodeling as evidenced by the lower levels of bone turnover markers. Furthermore, crocin reversed the oxidative stress status in both serum and bone tissue. The present study indicates that the administration of crocin at higher doses over a 16-week period can prevent OVX-induced osteoporosis in rats without hyperplastic effects on the uterus, which may, at least partially, be attributed to crocin’s antioxidative property. In brief, crocin is a natural alternative for postmenopausal osteoporosis treatment in elderly women

Phase Coupling of a Circadian Neuropeptide With Rest/Activity Rhythms Detected Using a Membrane-Tethered Spider Toxin

Drosophila clock neurons are self-sustaining cellular oscillators that rely on negative transcriptional feedback to keep circadian time. Proper regulation of organismal rhythms of physiology and behavior requires coordination of the oscillations of individual clock neurons within the circadian control network. Over the last decade, it has become clear that a key mechanism for intercellular communication in the circadian network is signaling between a subset of clock neurons that secrete the neuropeptide pigment dispersing factor (PDF) and clock neurons that possess its G protein-coupled receptor (PDFR). Furthermore, the specific hypothesis has been proposed that PDF-secreting clock neurons entrain the phase of organismal rhythms, and the cellular oscillations of other clock neurons, via the temporal patterning of secreted PDF signals. In order to test this hypothesis, we have devised a novel technique for altering the phase relationship between circadian transcriptional feedback oscillation and PDF secretion by using an ion channel–directed spider toxin to modify voltage-gated Na+ channel inactivation in vivo. This technique relies on the previously reported “tethered-toxin” technology for cell-autonomous modulation of ionic conductances via heterologous expression of subtype-specific peptide ion channel toxins as chimeric fusion proteins tethered to the plasma membrane with a glycosylphosphatidylinositol (GPI) anchor. We demonstrate for the first time, to our knowledge, the utility of the tethered-toxin technology in a transgenic animal, validating four different tethered spider toxin ion channel modifiers for use in Drosophila. Focusing on one of these toxins, we show that GPI-tethered Australian funnel-web spider toxin δ-ACTX-Hv1a inhibits Drosophila para voltage-gated Na+ channel inactivation when coexpressed in Xenopus oocytes. Transgenic expression of membrane-tethered δ-ACTX-Hv1a in vivo in the PDF-secreting subset of clock neurons induces rhythmic action potential bursts and depolarized plateau potentials. These in vitro and in vivo electrophysiological effects of membrane-tethered δ-ACTX-Hv1a are consistent with the effects of soluble δ-ACTX-Hv1a purified from venom on Na+ channel physiological and biophysical properties in cockroach neurons. Membrane-tethered δ-ACTX-Hv1a expression in the PDF-secreting subset of clock neurons induces an approximately 4-h phase advance of the rhythm of PDF accumulation in their terminals relative to both the phase of the day:night cycle and the phase of the circadian transcriptional feedback loops. As a consequence, the morning anticipatory peak of locomotor activity preceding dawn, which has been shown to be driven by the clocks of the PDF-secreting subset of clock neurons, phase advances coordinately with the phase of the PDF rhythm of the PDF-secreting clock neurons, rather than maintaining its phase relationship with the day:night cycle and circadian transcriptional feedback loops. These results (1) validate the tethered-toxin technology for cell-autonomous modulation of ion channel biophysical properties in vivo in transgenic Drosophila, (2) demonstrate that the kinetics of para Na+ channel inactivation is a key parameter for determining the phase relationship between circadian transcriptional feedback oscillation and PDF secretion, and (3) provide experimental support for the hypothesis that PDF-secreting clock neurons entrain the phase of organismal rhythms via the temporal patterning of secreted PDF signals

The Sihailongwan Maar Lake, northeastern China as a candidate Global Boundary Stratotype Section and Point for the Anthropocene Series

Sihailongwan Maar Lake, located in Northeast China, is a candidate Global boundary Stratotype Section and Point (GSSP) for demarcation of the Anthropocene. The lake’s varved sediments are formed by alternating allogenic atmospheric inputs and authigenic lake processes and store a record of environmental and human impacts at a continental-global scale. Varve counting and radiometric dating provided a precise annual-resolution sediment chronology for the site. Time series records of radioactive (239,240Pu, 129I and soot 14C), chemical (spheroidal carbonaceous particles, polycyclic aromatic hydrocarbons, soot, heavy metals, δ13C, etc), physical (magnetic susceptibility and grayscale) and biological (environmental DNA) indicators all show rapid changes in the mid-20th century, coincident with clear lithological changes of the sediments. Statistical analyses of these proxies show a tipping point in 1954 CE. 239,240Pu activities follow a typical unimodal globally-distributed profile, and are proposed as the primary marker for the Anthropocene. A rapid increase in 239,240Pu activities at 88 mm depth in core SHLW21-Fr-13 (1953 CE) is synchronous with rapid changes of other anthropogenic proxies and the Great Acceleration, marking the onset of the Anthropocene. The results indicate that Sihailongwan Maar Lake is an ideal site for the Anthropocene GSSP

Cellular Mechanism Underlying Hydrogen Sulfide Mediated Epithelial K+ Secretion in Rat Epididymis

As a novel gasotransmitter, hydrogen sulfide (H2S) elicits various physiological actions including smooth muscle relaxation and promotion of transepithelial ion transport. However, the pro-secretory function of H2S in the male reproductive system remains largely unclear. The aim of this study is to elucidate the possible roles of H2S in modulating rat epididymal intraluminal ionic microenvironment essential for sperm storage. The results revealed that endogenous H2S-generating enzymes cystathionine β-synthetase (CBS) and cystathionine γ-lyase (CSE) were both expressed in rat epididymis. CBS located predominantly in epithelial cells whilst CSE expressed primarily in smooth muscle cells. The relative expression level of CBS and CSE escalated from caput to cauda regions of epididymis, which was paralleled to the progressively increasing production of endogenous H2S. The effect of H2S on epididymal epithelial ion transportation was investigated using short-circuit current (ISC), measurement of intracellular ion concentration and in vivo rat epididymal microperfusion. Our data showed that H2S induced transepithelial K+ secretion via adenosine triphosphate-sensitive K+ (KATP) channel and large conductance Ca2+-activated K+ (BKCa) channel. Transient receptor potential vanilloid 4 (TRPV4) channel-mediated Ca2+ influx was implicated in the activation of BKCa channel. In vivo studies further demonstrated that H2S promoted K+ secretion in rat epididymal epithelium. Inhibition of endogenous H2S synthesis caused a significant decrease in K+ concentration of cauda epididymal intraluminal fluid. Moreover, our data demonstrated that high extracellular K+ concentration actively depressed the motility of cauda epididymal sperm in a pH-independent manner. Collectively, the present study demonstrated that H2S was vital to the formation of high K+ concentration in epididymal intraluminal fluid by promoting the transepithelial K+ secretion, which might contribute to the maintenance of the cauda epididymal sperm in quiescent dormant state before ejaculation