Low-Noise Amplification of a Continuous Variable Quantum State

We present an experimental realization of a low-noise, phase-insensitive optical amplifier using a four-wave mixing interaction in hot Rb vapor. Performance near the quantum limit for a range of amplifier gains, including near unity, can be achieved. Such low-noise amplifiers are essential for so-called quantum cloning machines and are useful in quantum information protocols. We demonstrate that amplification and ``cloning'' of one half of a two-mode squeezed state is possible while preserving entanglement.Comment: To appear in Physical Review Letters July 3rd. 4 pages, 4 figure

Metagenomic analysis reveals significant changes of microbial compositions and protective functions during drinking water treatment.

published_or_final_versio

Kinase inhibit region of SOCS3 attenuates IL6-induced proliferation and astrocytic differentiation of neural stem cells via cross talk between signaling pathways

Aims: Efficiency of neural stem cells (NSCs) therapy for brain injury is restricted by astrogliosis around the damaged region, in which JAK2/STAT3 signaling plays a key role. The SOCS3 that can directly inhibit JAK/STAT3 pathway. Here, we investigated the effects of a fusion peptide that combined kinase inhibitory region (KIR) of SOCS3 and virus trans-activator of transcription (TAT) on biological behavior of cultured NSCs under inflammatory conditions. Methods: NSCs were isolated from embryonic brain of SD rats, TAT-KIR was synthesized, and penetration rate was evaluated by flow cytometry (FACS). CCK8, immunostaining, and FACS were used to detected of TAT-KIR on the proliferation of NSCs. The expressions of GFAP and β tubulin III positive cells induced by IL6 with/without TAT-KIR were examined by immunostaining and Western blotting to observe the NSCs differentiation, and the effect of TAT-KIR on signaling cross talk was observed by Western blotting. Results: Penetration rate of TAT-KIR into primary cultured NSCs was up to 94%. TAT-KIR did not affect the growth and viability of NSCs. It significantly reduced the NSCs proliferation that enhanced by IL-6 stimulation via blocking the cell cycle progression from the G0/G1 to S phase. In addition, TAT-KIR attenuated astrocytic differentiation and kept high level of neuronal differentiation derived from IL-6-induced NSCs. The fate of NSCs differentiation under inflammatory conditions was affected by TAT-KIR, which was associated with synchronous inhibition of STAT3 and AKT, while promoting JNK expression. Conclusion: TAT-KIR mimetic of SOCS3 could be a promising approach for brain repair via regulating the biological behaviors of exogenous NSCs

Mesozoic subducted slabs under Siberia

Recent results from seismic tomography demonstrate that subducted oceanic lithosphere can be observed globally as slabs of relatively high seismic velocity in the upper as well as lower mantle(1,2). The Asian mantle is no exception, with high-velocity slabs being observed downwards from the west Pacific subduction zones under the Kurile Islands, Japan and farther south(3-5), as well as under Asia's ancient Tethyan margin. Here we present evidence for the presence of slab remnants of Jurassic age that were subducted when the Mongol-Okhotsk and Kular-Nera oceans closed between Siberia, the combined Mongolia-North China blocks and the Omolon block(6-8). We identify these proposed slab remnants in the lower mantle west of Lake Baikal down to depths of at least 2,500 km, where they join what has been interpreted as a 'graveyard'(9) of subducted lithosphere at the bottom of the mantle. Our interpretation implies that slab remnants in the mantle can still be recognized some 150 million years or more after they have been subducted and that such structures may be useful in associating geodynamic to surface-tectonic processes.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62524/1/397246a0.pd

An Unexpected Location of the Arginine Catabolic Mobile Element (ACME) in a USA300-Related MRSA Strain

In methicillin resistant Staphylococcus aureus (MRSA), the arginine catabolic mobile element (ACME) was initially described in USA300 (t008-ST8) where it is located downstream of the staphylococcal cassette chromosome mec (SCCmec). A common health-care associated MRSA in Copenhagen, Denmark (t024-ST8) is clonally related to USA300 and is frequently PCR positive for the ACME specific arcA-gene. This study is the first to describe an ACME element upstream of the SCCmec in MRSA. By traditional SCCmec typing schemes, the SCCmec of t024-ST8 strain M1 carries SCCmec IVa, but full sequencing of the cassette revealed that the entire J3 region had no homology to published SCCmec IVa. Within the J3 region of M1 was a 1705 bp sequence only similar to a sequence in S. haemolyticus strain JCSC1435 and 2941 bps with no homology found in GenBank. In addition to the usual direct repeats (DR) at each extremity of SCCmec, M1 had two new DR between the orfX gene and the J3 region of the SCCmec. The region between the orfX DR (DR1) and DR2 contained the ccrAB4 genes. An ACME II-like element was located between DR2 and DR3. The entire 26,468 bp sequence between DR1 and DR3 was highly similar to parts of the ACME composite island of S. epidermidis strain ATCC12228. Sequencing of an ACME negative t024-ST8 strain (M299) showed that DR1 and the sequence between DR1 and DR3 was missing. The finding of a mobile ACME II-like element inserted downstream of orfX and upstream of SCCmec indicates a novel recombination between staphylococcal species

Cyanobacterial bloom mitigation using proteins with high isoelectric point and chitosan-modified soil

A new environmental friendly method was developed for cyanobacterial blooms mitigation using local lake shore soil modified by protein with high isoelectric point (pI) and chitosan jointly. Results suggested that 5 mg/L lysozyme (pI ≈ 11) and 100 mg/L bromelain (pI ≈ 9.5) modified 10 mg/L soil can both reduce the surface charge of microcystis aeruginosa, the dominant species forming cyanobacterial blooms, from -26 mv to -10 mv and remove 73% and 60% of algal cells in 30 min, respectively. The limited improvement of removal efficiency was due to the small flocs (< 60 μm) formed by charge neutralization, which need more than 90 min to settle in static condition. However, when the small flocs were linked and bridged by the other modifier, chitosan with long polymer chain, large flocs of about 800 μm and 300 μm were fomed and more than 80% of algal cells were removed in 5 min and 30 min by lysozyme-chitosan modified soil and bromelain-chitosan modified soil, respectively. The lower removal ability of bromelain-modified soil was due to the lower charge density leading to less powerful in destabilization of algal cells. Depending on the bi-component modification mechanism including charge neutralization of proteins with high pI and netting and bridging function of chitosan with long polymer chain, it is possible to flocculate cyanobacterial blooms in natural waters effectively using locally available materials

Controllable Synthesis of Magnesium Oxysulfate Nanowires with Different Morphologies

One-dimensional magnesium oxysulfate 5Mg(OH)2 · MgSO4 · 3H2O (abbreviated as 513MOS) with high aspect ratio has attracted much attention because of its distinctive properties from those of the conventional bulk materials. 513MOS nanowires with different morphologies were formed by varying the mixing ways of MgSO4 · 7H2O and NH4OH solutions at room temperature followed by hydrothermal treatment of the slurries at 150 °C for 12 h with or without EDTA. 513MOS nanowires with a length of 20–60 μm and a diameter of 60–300 nm were prepared in the case of double injection (adding MgSO4 · 7H2O and NH4OH solutions simultaneously into water), compared with the 513MOS with a length of 20–30 μm and a diameter of 0.3–1.7 μm in the case of the single injection (adding MgSO4 · 7H2O solution into NH4OH solution). The presence of minor amount of EDTA in the single injection method led to the formation of 513MOS nanowires with a length of 100–200 μm, a diameter of 80–200 nm, and an aspect ratio of up to 1000. The analysis of the experimental results indicated that the hydrothermal solutions with a lower supersaturation were favorable for the preferential growth of 513MOS nanowires along b axis

Observation of a ppb mass threshoud enhancement in \psi^\prime\to\pi^+\pi^-J/\psi(J/\psi\to\gamma p\bar{p}) decay

The decay channel $\psi^\prime\to\pi^+\pi^-J/\psi(J/\psi\to\gamma p\bar{p})$ is studied using a sample of $1.06\times 10^8$ $\psi^\prime$ events collected by the BESIII experiment at BEPCII. A strong enhancement at threshold is observed in the $p\bar{p}$ invariant mass spectrum. The enhancement can be fit with an $S$-wave Breit-Wigner resonance function with a resulting peak mass of $M=1861^{+6}_{-13} {\rm (stat)}^{+7}_{-26} {\rm (syst)} {\rm MeV/}c^2$ and a narrow width that is $\Gamma<38 {\rm MeV/}c^2$ at the 90% confidence level. These results are consistent with published BESII results. These mass and width values do not match with those of any known meson resonance.Comment: 5 pages, 3 figures, submitted to Chinese Physics