69 research outputs found

    Linked region detection using high-density SNP genotype data via the minimum recombinant model of pedigree haplotype inference

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    <p>Abstract</p> <p>Background</p> <p>With the rapid development of high-throughput genotyping technologies, efficient methods for identifying linked regions using high-density SNP genotype data have become more and more important. Recently, a deterministic method that works very well on SNP genotyping data has been developed (Lin et al. Bioinformatics 2008, 24(1): 86–93). However, that program can only work on a limited number of family structures. In particular, the results (if any) will be poor when the genotype data for the whole chromosome of one of the parents in a nuclear family is missing.</p> <p>Results</p> <p>We have developed a software package (LIden) for identifying linked regions using high-density SNP genotype data. We focus on handling the case where the genotype data for the whole chromosome of one of the parents in a nuclear family is missing. We use the minimum recombinant model for haplotype inference in pedigrees. Several local optimization algorithms are used to infer the haplotype of each individual and determine the linked regions based on the inferred haplotype data. We have developed a more flexible method to combine nuclear families to further refine (reduce the length of) the linked regions.</p> <p>Conclusion</p> <p>Our new package (LIden) is efficient software for linked region detection using high-density SNP genotype data. LIden can handle some important cases where the existing programs do not work well. In particular, the new package can handle many cases where the genotype data of one of the two parents is missing for the entire chromosome. The running time of the program is <it>O</it>(<it>mn</it>), where <it>m </it>is the number of members in the family and <it>n </it>is the number of SNP sites in the chromosome. LIden is specifically suitable for handling big sized families. This research also demonstrates another practical use of the minimum recombinant model for haplotype inference in pedigrees.</p> <p>The software package can be downloaded at <url>http://www.cs.cityu.edu.hk/~lwang/software/Link</url>.</p

    Exploiting wireless received signal strength indicators to detect evil-twin attacks in smart homes

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    Evil-twin is becoming a common attack in Smart Home environments where an attacker can set up a fake AP to compromise the security of the connected devices. To identify the fake APs, The current approaches of detecting Evil-twin attacks all rely on information such as SSIDs, the MAC address of the genuine AP or network traffic patterns. However, such information can be faked by the attacker, often leading to low detection rates and weak protection. This paper presents a novel evil-twin attack detection method based on the received signal strength indicator (RSSI). Our key insight is that the location of the genuine AP rarely moves in a home environment and as a result the RSSI of the genuine AP is relatively stable. Our approach considers the RSSI as a fingerprint of APs and uses the fingerprint of the genuine AP to identify fake ones. We provide two schemes to detect a fake AP in two different scenarios where the genuine AP can be located at either a single or multiple locations in the property, by exploiting the multipath effect of the WIFI signal. As a departure from prior work, our approach does not rely on any professional measurement devices. Experimental results show that our approach can successfully detect 90% of the fake APs, at the cost of an one-off, modest connection delay

    Maize microrna166 inactivation confers plant development and abiotic stress resistance

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    MicroRNAs are important regulators in plant developmental processes and stress responses. In this study, we generated a series of maize STTM166 transgenic plants. Knock-down of miR166 resulted in various morphological changes, including rolled leaves, enhanced abiotic stress resistance, inferior yield-related traits, vascular pattern and epidermis structures, tassel architecture, as well as abscisic acid (ABA) level elevation and indole acetic acid (IAA) level reduction in maize. To profile miR166 regulated genes, we performed RNA-seq and qRT-PCR analysis. A total of 178 differentially expressed genes (DEGs) were identified, including 118 up-regulated and 60 down-regulated genes. These DEGs were strongly enriched in cell and intercellular components, cell membrane system components, oxidoreductase activity, single organism metabolic process, carbohydrate metabolic process, and oxidation reduction process. These results indicated that miR166 plays important roles in auxin and ABA interaction in monocots, yet the specific mechanism may differ from dicots. The enhanced abiotic stress resistance is partly caused via rolling leaves, high ABA content, modulated vascular structure, and the potential changes of cell membrane structure. The inferior yield-related traits and late flowering are partly controlled by the decreased IAA content, the interplay of miR166 with other miRNAs and AGOs. Taken together, the present study uncovered novel functions of miR166 in maize, and provide insights on applying short tandem target mimics (STTM) technology in plant breeding

    DRET:a system for detecting evil-twin attacks in smart homes

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    Evil-twin is one of most commonly attacks in the WIFI environments, with which an attacker can steal sensitive information by cloning a fake AP in Smart Homes. The current approaches of detecting Evil-twin AP uses some identities/fingerprints of legitimated APs to identify rouge APs. Prior work in the area uses information like SSIDs, MAC addresses, and network traffics to detect bogus APs. However, such information can be easily intimated by the attacker, leading to low detection rates. This paper introduces a novel Evil-Twin AP detection method based on received signal strength indicator (RSSI). Our approach exploits the fact that the AP location is relatively stable in Smart Homes, which is to great extent to meet the requirement of the detection factor not easy to imitate as previous refer. We employ two detection strategies: a single position detection and a multi-positioned detection methods. Our approach exploits the multipath effect of WIFI signals to translate the problem of attack detection into AP positioning detection. Compared to classical detection methods, our approach can perform detection without relying on professional devices. Experimental results show that the single position detection approach achieves 20 seconds’ reduction of delay time with an accuracy of 98%, whereas the multi-positioned detection approach achieves 90% correct

    Research on Mine Safety Monitoring System Based on WSN

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    AbstractIn this paper our experiences using a wireless sensor network to monitor the coal mines are described. The multi-sensor in one node can capture a variety of environmental data, including the vibration of the mine, the mine temperature, humidity and gas concentration, and environmental parameters control operation of the fan. Network consists of many wireless sensor nodes. Mine safety monitoring program has been developed to save the received data from sink nodes and show it on real time and analyze all kinds of information for decision function

    Study on Matching Constant Speed Propeller for Piston Engine on MALE UAV

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    The medium altitude long endurance (MALE) UAV has many advantages, which can be used to carry out a variety of military and civil missions, and has become the research and development hotspot of various countries. In order to make the MALE UAV have good dynamic and economic performance in all flight stages, a method of matching constant speed propeller for piston engine is proposed. According to the speed and fuel consumption characteristic curve of piston engine, the economic working points of the engine are selected and then efficiencies of each propeller on the economic working points above are compared and analyzed. Wind tunnel tests of full scale engine and propeller are conducted. Results show that the proposed method could be used to select optimal constant propeller for preliminarily selected piston engine

    Theoretical Investigation on the Hydrogen Evolution, Oxygen Evolution, and Oxygen Reduction Reactions Performances of Two-Dimensional Metal-Organic Frameworks Fe3(C2X)12 (X = NH, O, S)

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    Two-dimensional metal-organic frameworks (2D MOFs) inherently consisting of metal entities and ligands are promising single-atom catalysts (SACs) for electrocatalytic chemical reactions. Three 2D Fe-MOFs with NH, O, and S ligands were designed using density functional theory calculations, and their feasibility as SACs for hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and oxygen reduction reaction (ORR) was investigated. The NH, O, and S ligands can be used to control electronic structures and catalysis performance in 2D Fe-MOF monolayers by tuning charge redistribution. The results confirm the Sabatier principle, which states that an ideal catalyst should provide reasonable adsorption energies for all reaction species. The 2D Fe-MOF nanomaterials may render highly-efficient HER, OER, and ORR by tuning the ligands. Therefore, we believe that this study will serve as a guide for developing of 2D MOF-based SACs for water splitting, fuel cells, and metal-air batteries

    Crustal structure along the Zhenkang–Luxi deep seismic sounding profile in Yunnan derived from receiver functions

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    The crustal thicknesses and the Poisson's ratios under the seismic stations can be calculated by receiver function method with H-ҡ stacking effectively. But the stacking results are affected to some extent by the average crustal P-wave velocity. To eliminate this effect and get more accurate crustal structure along the Zhenkang–Luxi deep seismic sounding profile which lies in Yunnan Province, we calculate the receiver functions from the teleseismic events recorded by 11 temporary stations as well as 5 permanent ones along the profile and carry out the stacking with Vp obtained from the profile in this study. Our study shows that the crustal thicknesses along the Zhenkang–Luxi profile range from 34.8 km to 41.8 km with an average of 39 km. The crust is thicker in the middle part of the profile and thinner in both sides in general. Dramatic changes of crustal thickness about 3 km are detected across both the Lancangjiang fault and the Xiaojiang fault, which implies that these faults cut through the Moho. The lowest Poisson's ratio under the stations is 0.22 and the highest is 0.27 with the mean of 0.25, which is lower than the global average value 0.27 in the continental crust. It suggests that most of the crust along the profile lacks mafic component, but contains more felsic substance. The low Poisson's ratio also indicates that there is no satisfying condition for partial melting. We deduce that the material flow in the middle-lower crust in the southeastern margin of the Tibetan plateau may occur only in the north region of 24°N. Keywords: Receiver function, Crustal structure, Lancangjiang fault, Xiaojiang fault, Mid-lower crust flo

    The moisture absorption and retention abilities of quaternized carboxymethyl chitosan

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    Different types of quaternized carboxymethyl chitosans (QCMCs) were prepared in this study. The moisture absorption abilities of each QCMCs were measured at 81% and 43% relative humidity (RH), and the moisture retention abilities were done at 81% RH, at 43% RH and in silica gel. Hyaluronic acid (HA) was used as control in each condition. Results showed that, both at 81% and 43% RH, each QCMCs had better properties both in moisture absorption and retention than HA. And in silica gel, the moisture retention ability of each QCMCs was better than or close to that of HA. Therefore, it is hopeful that certain of the QCMCs would replace HA as the moisture absorption and retention ingredient in cosmetics in the future. &copy;2009 IEEE

    Can Preoperative Intravenous Corticosteroids Administration Reduce Postoperative Pain Scores Following Spinal Fusion?: A Meta-Analysis

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    Objective: This meta-analysis aimed to assess whether preoperative intravenous corticosteroids reduced postoperative pain in patients undergoing spinal fusion surgery. Methods: We systematically searched PubMed, Embase, the Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science and Google databases, from inception to March 29, 2018. Randomized controlled trials (RCTs) that compared preoperative intravenous glucocorticoids against a control treatment for the effect on pain following spinal fusion surgery were included. A meta-analysis was performed to generate a pooled risk ratio (RR) and weighted mean difference (WMD) with corresponding 95% confidence interval (CI) for discontinuous outcomes (the occurrence of postoperative nausea and vomiting [PONV] as well as surgical-site infections) and continuous outcomes (visual analog scale [VAS] scores at 12 h, 24 h, 48 h, and 72 h; total morphine consumption and the length of hospital stay), respectively. Results: Ten RCTs that compared intravenous corticosteroids versus placebo were included in our final meta-analysis. Compared with controls, intravenous corticosteroids were associated with a statistically significant reduction in pain VAS scores at 12 h, 24 h, 48 h, and 72 h. Additionally, intravenous corticosteroids decreased total morphine consumption, PONV, and the length of hospital stay. There was no significant difference between intravenous corticosteroids and controls, regarding the occurrence of infection (p > 0.05). Conclusions: In summary, our results indicated that intravenous corticosteroids not only reduce pain but also have anti-emetic effects. More studies should focus on the adverse effects of administering intravenous corticosteroids
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