1,255 research outputs found
Opportunistic Spectrum Sharing using Dumb Basis Patterns: The Line-of-Sight Interference Scenario
We investigate a spectrum-sharing system with non-severely faded mutual
interference links, where both the secondary-to-primary and
primary-to-secondary channels have a Line-of-Sight (LoS) component. Based on a
Rician model for the LoS channels, we show, analytically and numerically, that
LoS interference hinders the achievable secondary user capacity. This is caused
by the poor dynamic range of the interference channels fluctuations when a
dominant LoS component exists. In order to improve the capacity of such system,
we propose the usage of an Electronically Steerable Parasitic Array Radiator
(ESPAR) antenna at the secondary terminals. An ESPAR antenna requires a single
RF chain and has a reconfigurable radiation pattern that is controlled by
assigning arbitrary weights to M orthonormal basis radiation patterns. By
viewing these orthonormal patterns as multiple virtual dumb antennas, we
randomly vary their weights over time creating artificial channel fluctuations
that can perfectly eliminate the undesired impact of LoS interference. Because
the proposed scheme uses a single RF chain, it is well suited for compact and
low cost mobile terminals
Association Mapping of QTLs for Fusarium Head Blight Tolerance in a Structured Barley Population
Fusarium head blight (FHB) disease is one of the most challenging crop diseases; it reduces kernel weight, cause significant yield losses and quality reductions that may occur if fungal mycotoxins, especially deoxynivalenol (DON) are produced in infected seed. DON contamination has raised serious food safety concerns. Furthermore, straw of barley or wheat may be consumed by livestock could contain significant amounts of DON in chaff. Association mapping of a trait is to identify chromosomal regions that contain genes affecting the trait. The discovery of dense polymorphic markers covering the entire genome provides us an opportunity to localize these regions by trying to find the markers closest to the genes of interest. Association mapping was conducted in a structured barley population consists of (103 accessions of wild barley (H. vulgare ssp. spontaneum) core collection and 21 spring barley cultivars (H. vulgare ssp. vulgare)) in this study for identification of promising tolerance QTLs in barley against FHB. These experiments were carried out in the green-house during years 2009, 2010 and 2011 and under field-potted conditions in 2011, arranged in a completely randomized design with five replications, by using two different ways of scoring for disease infection leaves disease scoring (LDS) and spikes disease scoring (SDS) and two different fungus isolates. Heading date (HD) also had been recorded as a related trait for FHB in 2011. The accessions were genotyped by using 895 Diversity Arrays Technology (DArT) markers. Structure analysis was carried out for the all accessions using principal component analysis (PCA) the accessions were divided into 3 clusters and the relative kinship coefficients (K matrix) among all pairs of accessions were calculated by “SPAGeDi-1.3d” Software. The association analysis was performed in mixed linear model (MLM) including PCA values and K matrix. All studied traits LDS, SDS and HD were exhibited highly significantly differences in three years. Results from combined means in two years and two isolates showed that; 18 accessions had lower than 20 infection percentage for LDS and 48 accessions had lower than 20 infection percentage, 9 accessions from this group were lower than 10 infection percentage for SDS. Positive and significant phenotypic correlation has been recorded between LDS and SDS and negative correlation also have been recorded between SDS and HD in 2011. Seventy three markers were correlated significantly with all studied traits and covered the whole genome of the studied population. Different QTLs have been identified for LDS, leaves disease scoring isolates in 2011 (LDSI), SDS, spikes disease scoring isolates in 2011 (SDSI), visual leaves disease scoring (VS), HD, marker isolate interaction within leaves disease scoring (MILDS) and marker isolate interaction within spikes disease scoring (MISDS). Some of these QTLs were identified in two traits; marker bPb-0522 detected to SDSI and MISDS and also marker bPb-6466 detected to LDS and MILDS. Few of this QTLs were identified for two traits in the same/nearly position on the chromosome; in the position 122.08 cM on chromosome 6H two markers (bPb-4379 and bPb-3375) were identified to be associated with SDS and HD. Also in chromosome 2H on 70.8 cM two markers detected to LDS and SDS. In the study a mixed model was tested for the epistatic interaction between all DArT markers and studied traits. Interactions were detected between 11 pairs of QTLs for FHB resistance/tolerance and one interaction for heading date, which involved 24 QTLs on 6 chromosomes. The results indicated that barley FHB resistance/tolerance is a complicated trait and may be controlled by a complicated gene network.Ährenfusariosen (FHB) verursachen eine der am schwierigsten zu bekämpfenden Pflanzenkrankheiten. Es reduziert das Korngewicht, führt zu erheblich Ertragsausfällen und Qualitätseinbußen die auftreten, wenn Mykotoxine und insbesondere Deoxynivalenol (DON) im infizierten Samen produziert werden. DON Kontaminationen geben auch in der Lebensmittelsicherheit Anlass zur Besorgnis. Darüber hinaus könnte Gersten- oder Weizenstroh, das als Viehfutter dient signifikante Mengen von DON im Spreu enthalten. Association mapping eines Merkmals dient zur Identifizierung einer chromosomalen Region, deren Gene die untersuchte Information enthalten. Die Entdeckung von immer mehr polymorphen Markern über das gesamte Genom gibt uns die Möglichkeit mit deren Hilfe Regionen zu lokalisieren, die nah an den interessanten Genen liegen. Ein association mapping in Gerste wurde zur Identifizierung von vielversprechenden Toleranz QTLs gegen FHB durchgeführt. Dazu diente eine Gerstenpopulation bestehend aus 103 Wild forms (H. vulgare ssp. spontaneum) als "Core Collection" und 21 Sommergerstensorten (H. vulgare ssp. vulgare). Die Experimente wurden in den Jahren 2009, 2010 und 2011 im Gewächshaus und unter Feldbedingungen im Jahr 2011durchgeführt. In fünf Wiederholungen wurden die Experimente in einem vollständig zufälligen Design angeordnet und anschließend mit zwei verschiedenen Pilz-Isolaten infiziert. Die Auswertung der Infektionsstärke wurde mit leaves disease scoring (LDS) und spikes disease scoring (SDS) durchgeführt. Im Jahr 2011 wurde auch der Tag des Ährenschiebens (HD) als verwandtes Merkmal für FHB Infektion mit in die Untersuchungen aufgenommen. Die Erfassung der genetischen Informationen wurden mit 895 Diversity Array Technology (DArT) Markern vorgenommen. Eine Strukturanalyse wurde für alle Genotypen mittels Hauptkomponentenanalyse (PCA) durchgeführt und konnte diese in 3 Cluster aufteilen. Der relative Verwandtschaftskoeffizient (K-Matrix) unter allen Genotypen wurde mit der "SPAGeDi-1.3d" Software berechnet. Die Assoziationsstudie wurde in einem mixed linear model (MLM) unter Berücksichtignug der PCA-Werte und der K-Matrix durchgeführt. Alle untersuchten Merkmale LDS, SDS und HD zeigten hochsignifikant Unterschiede in den drei Jahren. Wenn man die Mittelwerte aus zwei Jahren und zwei Isolaten kombiniert kann gezeigt werden, dass 18 Genotypen einen Befall von weniger als 20% für LDS aufwiesen. Nach der Datenerfassung mit dem SDS konnten 48 Genotypen mit einen Befall von weniger als 20% und 9 mit einem Befall von weniger als 10% bewertet werden. Positive und signifikante phänotypische Korrelationen konnten zwischen LDS und SDS berechnet werden. Eine negative Korrelationen zeigte sich zwischen SDS und HD im Jahr 2011. Dreiundsiebzig Marker korrelierten signifikant mit allen untersuchten Merkmalen und waren über das gesamte Genom der untersuchten Population verteilt. Verschiedene QTLs konnten für LDS, leaves disease scoring isolates in 2011 (LDSI), SDS, spikes disease scoring isolates in 2011 (SDSI), visual leaves disease scoring (VS), HD, marker isolate interaction within leaves disease scoring (MILDS) und marker isolate interaction within spikes disease scoring (MISDS) identifiziert werden. Einige QTLs wurden in zwei Merkmalen identifiziert. Marker bpb-0522 wurde mit SDSI und MISDS und der Marker bPb-6466 durch LDS und MILDS nachgewiesen. Einige dieser QTLs wurden für zwei Merkmale auf der selben, beziehungsweise nahezu der gleichen Position auf dem Chromosom identifiziert. Auf der Position 122,08cM auf Chromosom 6H wurden zwei Marker (bPb-4379 und bPb-3375) die mit SDS und HD assoziieren entdeckt. Auch im Chromosom 2H auf 70,8 cM wurden zwei Marker für LDS und SDS erkannt. In der Studie wurde ein mixed model für die epistatische Interaktion zwischen allen DArT Markern und den untersuchten Merkmalen getestet. Wechselwirkungen zwischen 11 Paaren von QTLs für FHB Resistenz, beziehungsweise Toleranz und eine Interaktion zu dem Beginn des Ährenschiebens, an dem 24 QTLs auf sechs Chromosomen beteiligt sind wurden erkannt. Die Ergebnisse zeigten, dass Gerste FHB Resistenz und Toleranz eint kompliziertes Merkmal ist und durch eine kompliziertes Gen Netzwerk gesteuert wird
Synthesis of novel pyrimidine and fused pyrimidine derivatives
4-Amino-2-(benzylthio)-6-(4-methoxyphenyl)pyrimidine-5-carbonitrile (1) was prepared by treatment of s-benzylthiuronium chloride with 2-(4-methoxybenzylidene)malononitrile in ethanolic sodium hydroxide with hydrazine hydrate to afford the hydrazino derivative 2, which was allowed to react with different electrophilic reagents to give the pyrimidine derivatives 3-12. The proclivity of (E)-2-cyano-3-(4-nitrophenyl)acrylamide (13) towards carbon and nitrogen nucleophiles was also investigated. IR, 1H NMR and mass spectra for all the synthesized compounds were discussed. All derived compounds were investigated for anti avian influenza (H5N1) virus activity and compared with zanamivir as control drug. All the synthesized compounds didn’t possess any antiviral activity
Stratigraphic Correlation of Devonian Sequences of Northwestern Darling Basin, New South Wales, Australia
The study is focused on the Northwestern part of theDarling Basin, and deals with a Stratigraphic correlation. Thisstudy involves correlation of the regional stratigraphy in theDarling Basin of western New South Wales that results fromdeformation of the Devonian sequences. The interpretation basedon well logs and lihological data. Integrating well and lithologicaldata to correlate the sequence stratigraphic units, using sequencestratigraphy approach are the main goals of this study. Analysesof lithostratigraphic units from well-logs and lithology data wereused to develop a stratigraphic correlation of the northwestDarling Basin. The stratigraphic boundaries of the intervals weredefined at marked changes in well-log characteristics andlithology information. Correlation of three wells in thenorthwestern part of Darling Basin allowed correlation andchronostratigraphic subdivision of Devonian sediments. Thelithofacies of three wells Bancannia North-1, Bancanna South-1and Jupiter-1 have been identified from northwest to southeast.The lithofacies dominated by sandstone and shale sedimentsmostly in Lower to Middle Devonian age, red sandstone, poroussandstone and shale lithofacies (red beds) of Middle to UpperDevonian sediments. Three stratigraphic units were identifiedbased on well logs characteristics and lithofacies namely A, B andC
Interaction diagram for RC column strengthened by steel angles and strips
This paper presents an analytical model to construct the interaction diagrams (normal force and moment) for the RC column strengthened using the steel jacket technique. The proposed model is defined using the strain distribution block by determining the location of the neutral axis in the concrete section. The proposed analytical formulation is verified by experimental results performed by previous researches and numerical models using the nonlinear program ANSYS. The factors affecting the capacity of the strengthened column are taken into consideration, such as the amount of loads resisted by the steel cage, steel strips spacing, and the effect of concrete confinement. The results of the proposed model are in good agreement with the results from the experimental and numerical work used in verification. A practical design formula has been presented for strengthened columns
Usporedba antibakterijskoga učinka probiotičkog jogurta i žvakaće gume koja sadržava ksilitol kod gerijatrijskih pacijenata: randomizirano kontrolirano kliničko istraživanje
Objectives: To evaluate the effect of probiotic bacteria in yogurt on Streptococcus mutans (MS) count, plaque adherence and salivary pH compared to xylitol-containing chewing gum in geriatric patients. Material and methods: Total number of 96 high caries risk geriatric patients were randomized into two equal groups (n=48). Group 1 (intervention group) received probiotic yogurt (Activia, Danone) once per day, and group 2 (control group) received xylitol chewing gum (Trident original) three times per day. The primary outcome was salivary Streptococcus mutans count and secondary outcomes were interdental plaque Streptococcus mutans count, salivary pH and bacterial adherence. Results: For Streptococcus mutans count in saliva and plaque, a statistically significant reduction in the level of MS over all the examined follow up periods of the study in probiotic yogurt group as well as xylitol gum group was found. An intergroup comparison for salivary MS count showed statistically significant difference between the two materials in a two week and a three month period of time and there was no statistically significant difference between both materials at one month time period. Salivary pH results showed statistically significant increase in pH in both groups along the follow-up periods. Bacterial adherence results showed statistically significant reduction in both groups. Conclusions: Probiotic yogurt is an effective antibacterial agent against salivary and plaque bacteria in geriatric patients.Svrha istraživanja: Procijeniti kod gerijatrijskih pacijenata učinak probiotičkih bakterija u jogurtu prema broju bakterija Streptococcus mutans (SM), adherenciji plaka i pH sline u usporedbi sa žvakaćom gumom koja sadržava ksilitol. Materijali i metode: Ukupan broj od 96 gerijatrijskih pacijenata s visokim rizikom od pojave karijesa randomiziran je u dvije jednake skupine (n = 48). Skupina 1 (interventna skupina) konzumirala je probiotički jogurt (Activia, Danone) jedanput na dan, a skupina 2 (kontrolna skupina) dobivala je žvakaću gumu sa ksilitolom (Trident original) tri puta na dan. Primarni ishod bio je broj bakterija Streptococcus mutans u slini, a sekundarno se želio doznati broj tih bakterija u interdentalnom plaku, pH sline i adherencija SM-a. Rezultati: Za broj bakterija Streptococcus mutans u slini i plaku postignuto je statistički značajno smanjenje njihove razine tijekom svih razdoblja praćenja u skupini s probiotičkim jogurtom te u skupini sa žvakaćom gumom koja sadržava ksilitol. Međugrupna usporedba za broj SM-a u slini pokazala je statistički značajnu razliku između dvaju materijala u razmaku od dva tjedna i tri mjeseca, a nije bilo statistički značajne razlike između obaju materijala u razdoblju od jednog mjeseca. Rezultati pH sline pokazali su statistički značajno povećanje vrijednosti u objema skupinama tijekom razdoblja praćenja. Rezultati bakterijske adherencije pokazali su statistički značajno smanjenje u objema skupinama. Zaključak: Probiotički jogurt učinkovito je antibakterijsko sredstvo protiv bakterija u slini i plaku kod gerijatrijskih pacijenata
Population Dynamics of Phytophthora infestans in Egypt Reveals Clonal Dominance of 23_A1 and Displacement of 13_A2 Clonal Lineage
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