Improved Decoding of Staircase Codes: The Soft-aided Bit-marking (SABM) Algorithm

Staircase codes (SCCs) are typically decoded using iterative bounded-distance decoding (BDD) and hard decisions. In this paper, a novel decoding algorithm is proposed, which partially uses soft information from the channel. The proposed algorithm is based on marking certain number of highly reliable and highly unreliable bits. These marked bits are used to improve the miscorrection-detection capability of the SCC decoder and the error-correcting capability of BDD. For SCCs with $2$-error-correcting Bose-Chaudhuri-Hocquenghem component codes, our algorithm improves upon standard SCC decoding by up to $0.30$~dB at a bit-error rate (BER) of $10^{-7}$. The proposed algorithm is shown to achieve almost half of the gain achievable by an idealized decoder with this structure. A complexity analysis based on the number of additional calls to the component BDD decoder shows that the relative complexity increase is only around $4\%$ at a BER of $10^{-4}$. This additional complexity is shown to decrease as the channel quality improves. Our algorithm is also extended (with minor modifications) to product codes. The simulation results show that in this case, the algorithm offers gains of up to $0.44$~dB at a BER of $10^{-8}$.Comment: 10 pages, 12 figure

No-compressing of quantum phase information

We raise a general question of quantum information theory whether the quantum phase information can be compressed and retrieved. A general qubit contains both amplitude and phase information, while an equatorial qubit contains only a phase information. We study whether it is possible to compress the phase information of n equatorial qubits into m general qubits with m being less than n, and still those information can be retrieved perfectly. We prove that this process is not allowed by quantum mechanics.Comment: 4 pages, 1 figur

Co-delivery of polymeric metformin and cisplatin by self-assembled core-membrane nanoparticles to treat non-small cell lung cancer

Clinically, combined therapy of cisplatin (CDDP) and metformin is an effective treatment for non-small cell lung cancer (NSCLC). The success is attributed to synergistic effects between the two drugs. Therefore, we hypothesize that co-encapsulation of CDDP and metformin will avoid the prominent toxicity of CDDP while maintaining the synergy between the regimens. CDDP was first conjugated to polyglutamic acid (PGA) to form anionic PGA-CDDP which was electrostatically complexed with the cationic polymeric metformin (polymet). The nano-sized complex was then stabilized with cationic liposomes composed of DOTAP (2, 3-Dioleoyloxy-propyl)-trimethylammonium/Cholesterol/DSPE-PEG-anisamide aminoethyl. Both in vitro and in vivo experiments confirmed the synergy between polymet and CDDP. CDDP delivered with nanoparticles (NPs) exhibited significantly increased tumor accumulation over free CDDP and suppressed tumor growth through apoptosis in NSCLC H460 tumor-bearing mice without nephrotoxicity. The synergistic effect of polymet alongside CDDP demonstrates that polymet-CDDP NPs can activate the AMP-activated protein kinase α (AMPKα) pathway and inhibit mammalian target rapamycin (mTOR) activity to enhance growth suppression. In all, this platform is the first to successfully co-load polymet, a polymeric metformin, and CDDP into the same nanoparticle for successful treatment of NSCLC

The effects of Tbx15 and Pax1 on facial and other physical morphology in mice

DNA variants in or close to the human TBX15 and PAX1 genes have been repeatedly associated with facial morphology in independent genome‐wide association studies, while their functional roles in determining facial morphology remain to be understood. We generated Tbx15 knockout (Tbx15 (−/−)) and Pax1 knockout (Pax1 (−/−)) mice by applying the one‐step CRISPR/Cas9 method. A total of 75 adult mice were used for subsequent phenotype analysis, including 38 Tbx15 mice (10 homozygous Tbx15 (−/−), 18 heterozygous Tbx15 (+/−), 10 wild‐type Tbx15 (+/+) WT littermates) and 37 Pax1 mice (12 homozygous Pax1 (−/−), 15 heterozygous Pax1 (+/−), 10 Pax1 (+/+) WT littermates). Facial and other physical morphological phenotypes were obtained from three‐dimensional (3D) images acquired with the HandySCAN BLACK scanner. Compared to WT littermates, the Tbx15 (−/−) mutant mice had significantly shorter faces (p = 1.08E‐8, R(2) = 0.61) and their ears were in a significantly lower position (p = 3.54E‐8, R(2) = 0.62) manifesting a “droopy ear” characteristic. Besides these face alternations, Tbx15 (−/−) mutant mice displayed significantly lower weight as well as shorter body and limb length. Pax1 (−/−) mutant mice showed significantly longer noses (p = 1.14E‐5, R(2) = 0.46) relative to WT littermates, but otherwise displayed less obvious morphological alterations than Tbx15 (−/−) mutant mice did. We provide the first direct functional evidence that two well‐known and replicated human face genes, Tbx15 and Pax1, impact facial and other body morphology in mice. The general agreement between our findings in knock‐out mice with those from previous GWASs suggests that the functional evidence we established here in mice may also be relevant in humans

Magnetic coupling of a rotating black hole with its surrounding accretion disk

Effects of magnetic coupling (MC) of a rotating black hole (BH) with its surrounding accretion disk are discussed in detail in the following aspects: (i) The mapping relation between the angular coordinate on the BH horizon and the radial coordinate on the disk is modified based on a more reasonable configuration of magnetic field, and a condition for coexistence of the Blandford-Znajek (BZ) and the MC process is derived. (ii) The transfer direction of energy and angular momentum in MC process is described equivalently by the co-rotation radius and by the flow of electromagnetic angular momentum and redshifted energy, where the latter is based on an assumption that the theory of BH magnetosphere is applicable to both the BZ and MC processes. (iii) The profile of the current on the BH horizon and that of the current density flowing from the magnetosphere onto the horizon are given in terms of the angular coordinate of the horizon. It is shown that the current on the BH horizon varies with the latitude of the horizon and is not continuous at the angular boundary between the open and closed magnetic field lines. (iv) The MC effects on disk radiation are discussed, and a very steep emissivity is produced by MC process, which is consistent with the recent XMM-Newton observation of the nearby bright Seyfert 1 galaxy MCG-6-30-15 by a variety of parameters of the BH-disk system.Comment: 24 pages, 19 figures. Accepted by Ap

Screw instability of the magnetic field connecting a rotating black hole with its surrounding disk

Screw instability of the magnetic field connecting a rotating black hole (BH) with its surrounding disk is discussed based on the model of the coexistence of the Blandford-Znajek (BZ) process and the magnetic coupling (MC) process (CEBZMC). A criterion for the screw instability with the state of CEBZMC is derived based on the calculations of the poloidal and toroidal components of the magnetic field on the disk. It is shown by the criterion that the screw instability will occur, if the BH spin and the power-law index for the variation of the magnetic field on the disk are greater than some critical values. It turns out that the instability occurs outside some critical radii on the disk. It is argued that the state of CEBZMC always accompanies the screw instability. In addtition, we show that the screw instability contributes only a small fraction of magnetic extraction of energy from a rotating BH.Comment: 18 pages, 13 figures; Accepted by Ap

PolyMetformin combines carrier and anticancer activities for in vivo siRNA delivery

Metformin, a widely implemented anti-diabetic drug, exhibits potent anticancer efficacies. Herein a polymeric construction of Metformin, PolyMetformin (PolyMet) is successfully synthesized through conjugation of linear polyethylenimine (PEI) with dicyandiamide. The delocalization of cationic charges in the biguanide groups of PolyMet reduces the toxicity of PEI both in vitro and in vivo. Furthermore, the polycationic properties of PolyMet permits capture of siRNA into a core-membrane structured lipid-polycation-hyaluronic acid (LPH) nanoparticle for systemic gene delivery. Advances herein permit LPH-PolyMet nanoparticles to facilitate VEGF siRNA delivery for VEGF knockdown in a human lung cancer xenograft, leading to enhanced tumour suppressive efficacy. Even in the absence of RNAi, LPH-PolyMet nanoparticles act similarly to Metformin and induce antitumour efficacy through activation of the AMPK and inhibition of the mTOR. In essence, PolyMet successfully combines the intrinsic anticancer efficacy of Metformin with the capacity to carry siRNA to enhance the therapeutic activity of an anticancer gene therapy

General Quantum Key Distribution in Higher Dimension

We study a general quantum key distribution protocol in higher dimension. In this protocol, quantum states in arbitrary $g+1$ ($1\le g\le d$) out of all $d+1$ mutually unbiased bases in a d-dimensional system can be used for the key encoding. This provides a natural generalization of the quantum key distribution in higher dimension and recovers the previously known results for $g=1$ and $d$. In our investigation, we study Eve's attack by two slightly different approaches. One is considering the optimal cloner for Eve, and the other, defined as the optimal attack, is maximizing Eve's information. We derive results for both approaches and show the deviation of the optimal cloner from the optimal attack. With our systematic investigation of the quantum key distribution protocols in higher dimension, one may balance the security gain and the implementation cost by changing the number of bases in the key encoding. As a side product, we also prove the equivalency between the optimal phase covariant quantum cloning machine and the optimal cloner for the $g=d-1$ quantum key distribution

Photosynthesis-independent production of reactive oxygen species in the rice bundle sheath during high light is mediated by NADPH oxidase.

When exposed to high light, plants produce reactive oxygen species (ROS). In Arabidopsis thaliana, local stress such as excess heat or light initiates a systemic ROS wave in phloem and xylem cells dependent on NADPH oxidase/respiratory burst oxidase homolog (RBOH) proteins. In the case of excess light, although the initial local accumulation of ROS preferentially takes place in bundle-sheath strands, little is known about how this response takes place. Using rice and the ROS probes diaminobenzidine and 2',7'-dichlorodihydrofluorescein diacetate, we found that, after exposure to high light, ROS were produced more rapidly in bundle-sheath strands than mesophyll cells. This response was not affected either by CO2 supply or photorespiration. Consistent with these findings, deep sequencing of messenger RNA (mRNA) isolated from mesophyll or bundle-sheath strands indicated balanced accumulation of transcripts encoding all major components of the photosynthetic apparatus. However, transcripts encoding several isoforms of the superoxide/H2O2-producing enzyme NADPH oxidase were more abundant in bundle-sheath strands than mesophyll cells. ROS production in bundle-sheath strands was decreased in mutant alleles of the bundle-sheath strand preferential isoform of OsRBOHA and increased when it was overexpressed. Despite the plethora of pathways able to generate ROS in response to excess light, NADPH oxidase-mediated accumulation of ROS in the rice bundle-sheath strand was detected in etiolated leaves lacking chlorophyll. We conclude that photosynthesis is not necessary for the local ROS response to high light but is in part mediated by NADPH oxidase activity