Population Redistribution among Multiple Electronic States of Molecular Nitrogen Ions in Strong Laser Fields

We carry out a combined theoretical and experimental investigation on the population distributions in the ground and excited states of tunnel ionized N2 molecules at various driver wavelengths in the near- and mid-infrared range. Our results reveal that efficient couplings (i.e., population exchanges) between the ground state and the excited states occur in strong laser fields. The couplings result in the population inversion between the ground and the excited states at the wavelengths near 800 nm, which is verified by our experiment by observing the amplification of a seed at ~391 nm. The result provides insight into the mechanism of free-space nitrogen ion lasers generated in remote air with strong femtosecond laser pulses.Comment: 18 pages, 4 figure

A Survey on Botnet Attacks

Devices connected to the Internet are the target of numerous attacks to steal or exploit their resources. As these attacks become widespread (and sophisticated), the first step in protecting your organization is knowing exactly what you are facing. We currently have botnets that are the main source of network attacks such as spam, denial of service (DDoS), click fraud, data theft, Pass the Hash, and RDC attack. With the evolution of technology, we have several solutions to protect against attacks that undermine businesses, governments, individuals, but security attack methods are increasing daily. This study seeks further investigate botnet attacks and also provide a comparison of these attacks, lastly, the survey will create awareness for forthcoming botnet research endeavors

A general QoS aware flow-balancing and resource management scheme in distributed software-defined networks

Due to the limited service capabilities of centralized controllers, it is difficult to process high volume of flows within reasonable time. This particularly degrades the strict quality of service (QoS) requirements of interactive media applications, which is non-negligible factor. To alleviate this concern, distributed deployments of software-defined network (SDN) controllers are inevitable and have gained a predominant position. However, to maintain application specific QoS requirements, the number of resources used in network directly impacts the capital and operational expenditure. Hence, in distributed SDN architectures, issues such as flow arrival rate, resources required and operational cost have significant mutual dependencies on each other. Therefore, it is essential to research feasible methods to maintain QoS and minimize resources provisioning cost. Motivated from this, we propose a solution in a distributed SDN architectures that provides flow-balancing (with guaranteed QoS) in pro-active operations of SDN controllers, and attempts to optimize the use of instance resources provisioning costs. We validate our solution using the tools of queuing theory. Our studies indicate that with our solution, a network with minimum resources and affordable cost with guaranteed application QoS can be set-up

Privacy-Aware Fuzzy Range Query Processing Over Distributed Edge Devices

Range query processing is a common edge computing and service in the Internet of Things, which can extract user-interest information from distributed edge devices. How to design lightweight privacy-preserving range query processing methods remains a challenging task. Existing secure range query approaches suffer from both high communication cost and long response time, which makes them unsuitable for edge computing over resource-constrained edge devices. In this paper, we propose two privacy-aware fuzzy query processing schemes based on fuzzy theory. Linguistic range variables, fuzzy overlap information and its recovery mechanism are introduced respectively. In addition, two distributed privacy-aware fuzzy range query processing algorithms are devised. Our approaches not only serve for privacy protection, but also aim to provide other optimal performances in terms of reliability, energy efficiency, and real-time response. Theoretical analysis and experimental evaluations based on real-world data sets validated our motivation

GWAS Identifies Novel Susceptibility Loci on 6p21.32 and 21q21.3 for Hepatocellular Carcinoma in Chronic Hepatitis B Virus Carriers

Genome-wide association studies (GWAS) have recently identified KIF1B as susceptibility locus for hepatitis B virus (HBV)–related hepatocellular carcinoma (HCC). To further identify novel susceptibility loci associated with HBV–related HCC and replicate the previously reported association, we performed a large three-stage GWAS in the Han Chinese population. 523,663 autosomal SNPs in 1,538 HBV–positive HCC patients and 1,465 chronic HBV carriers were genotyped for the discovery stage. Top candidate SNPs were genotyped in the initial validation samples of 2,112 HBV–positive HCC cases and 2,208 HBV carriers and then in the second validation samples of 1,021 cases and 1,491 HBV carriers. We discovered two novel associations at rs9272105 (HLA-DQA1/DRB1) on 6p21.32 (OR = 1.30, P = 1.13×$10^{−19}$) and rs455804 (GRIK1) on 21q21.3 (OR = 0.84, P = 1.86×$10^{−8}$), which were further replicated in the fourth independent sample of 1,298 cases and 1,026 controls (rs9272105: OR = 1.25, P = 1.71×$10^{−4}$; rs455804: OR = 0.84, P = 6.92×$10^{−3}$). We also revealed the associations of HLA-DRB1*0405 and 0901*0602, which could partially account for the association at rs9272105. The association at rs455804 implicates GRIK1 as a novel susceptibility gene for HBV–related HCC, suggesting the involvement of glutamate signaling in the development of HBV–related HCC

Smoking and Genetic Risk Variation Across Populations of E uropean, A sian, and A frican A merican Ancestry—A Meta‐Analysis of Chromosome 15q25

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/91126/1/gepi21627.pd

Evolution of the spinach sex-linked region within a rarely recombining pericentro-meric region

Sex chromosomes have evolved independently in many different plant lineages. Here, we describe reference genomes for spinach (Spinacia oleracea) X and Y haplotypes by sequencing homozygous XX females and YY males. The long arm of 185-Mb chromosome 4 carries a 13-Mb X-linked region (XLR) and 24.1-Mb Y-linked region (YLR), of which 10 Mb is Y specific. We describe evidence that this reflects insertions of autosomal sequences creating a “Y duplication region” or “YDR” whose presence probably directly reduces genetic recombination in the immediately flanking regions, although both the X and Y sex-linked regions are within a large pericentromeric region of chromosome 4 that recombines rarely in meiosis of both sexes. Sequence divergence estimates using synonymous sites indicate that YDR genes started diverging from their likely autosomal progenitors about 3 MYA, around the time when the flanking YLR stopped recombining with the XLR. These flanking regions have a higher density of repetitive sequences in the YY than the XX assembly and include slightly more pseudogenes compared with the XLR, and the YLR has lost about 11% of the ancestral genes, suggesting some degeneration. Insertion of a male-determining factor would have caused Y linkage across the entire pericentromeric region, creating physically small, highly recombining, terminal pseudoautosomal regions. These findings provide a broader understanding of the origin of sex chromosomes in spinach