2,720 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
Cystic echinococcosis in humans and domestic animals in central Sudan:Epidemiology and molecular characterization studies
Cystic echinococcosis (CE) is a significant public health problem with high endemicity in east and central Africa including Sudan. Worldwide, pulmonary (pu) echinococcosis (EC) is the second to liver affection, where as in Sudan is vice versa. Ten genetic variants, or genotypes designated as (G1-G10), are distributed worldwide based on genetic diversity. (in Chapter7), we investigated molecular diversity of Echinococcus granulosus isolates collected from human clinical samples removed surgically from lung using mitochondrial gene nad1 in Sudan. It can be concluded that the pul echinococcosis in Sudan are caused by genotype 6 (G6) camel strain of E. granulosus. To improve management knowledge, attitudes and practices in human population has been conducted in quest, section III (Chapter 8). Since the level of knowledge has been found to be poor, hence is the need for the One Health approach to prevent EC. In Section IV, a cross sectional study was conducted among residents of Khartoum State in Central Sudan to determine the prevalence of CE (Chapter 9).The present investigations was conducted to improve the diagnostic potential including sequencing and phylogenetic analysis as well as LAMP and Realtime PCR .We gave an overview on the prevalent species or strains of Echinococcus granulosus in sub-Saharan Africa, treatment and preventive strategies.(Chapter 2).Part of our research was conducted in Tamboul, Central Sudan to determine the prevalence of CE genotypes and the result indicates that for the first time circulation of E. ortleppi, the cattle genotype (G5) in camel (Chapter 3) as well as G1 in Cattles (Chapter 6)
Detection of antibiotic-producing bacteria from soil samples in parts of Wudil local government area Kano State, Nigeria
The emergence of new diseases and multiple-antibiotic resistance pathogens that resist the action of clinically used antibiotics have increased the needs of discovering new antibiotics. However, soil served as the most important target for most researchers in their attempt of discovering new antibiotics that have pharmaceutical values. The aim of this study was to detect the antibiotic-producing bacteria from soil samples in parts of Wudil local government of Kano state using standard procedure. The color ranged from light brown to dark brown. The texture ranged from clay loam, clay and loam. Sample C was found to have the highest mean pH and electrical conductivity of 7.46 and 108.90Ī¼s/cm, respectively, while sample B had the least mean values of 6.95 and 73.53Ī¼s/cm, respectively. The highest mean bulk devsity and particle density was sample B with 1.60g/cm3 and 1.87g/cm3, respectively, while sample C had the least mean values of 1.48g/cm3 and 1.71g/cm3, respectively. Sample C was found to have the highest mean moisture content and porosity with 17.93% and 15.57%, respectively, while sample A had the least mean values with 10.61% and 10.74%, respectively. Four bacterial spp. were identified based on morphological description, gramās reaction and biochemical tests, and were identified as Bacillus spp., Micrococcus spp., Pseudosomonas spp. and Proteus spp. Sample C was found to have the highest mean total bacterial viable plate count of 19.9Ć105cfu/g, while sample B had the least mean value of 4.1Ć105cfu/g. Bacillus spp. was found to have the highest percentage occurrence with 21(47%), while Proteus spp. had the least value with 4(9%). E. coli had the highest and least susceptibility to metabolites produced by Bacillus spp. and Pseudosomonas spp. with inhibition zones of (17 and 0mm) respectively. While the control (Erythromycin 250mg/ml) produced the inhibition zones of (27 and 21mm) against E. coli and S. aureus respectively. It was concluded that soil samples in Lajawa, Kausani, Wudil Sabon gari and Wudil Tsohon gari of Wudil local government contained the bacteria with potentiality of producing antimicrobial substance and recommended the use of molecular techniques for further characterization
PP-172 Detection of the relation between the presence of Chlamydial antigen in the cervix of infertile women and the condition of their tubes
Field Evaluation Of Temephos And Agnique MMF Against Immature Stages Of Anopheles Arabiensis Patton (Diptera : Culicidae) The Vector Of Malaria In Khartoum, Sudan [RA644.M2 A286 2007 f rb].
Dua kajian lapangan telah dilakukan dalam kolam terstimulasi di Skim Pertanian Al-sielate Bahary, Khartoum, Sudan, selama 13 minggu (percubaan 1) dan 9 minggu (percubaan ke-2).
Two field experiments on mosquitoes were conducted in stimulated ponds at Al-sielate Agricultural Scheme of Bahary locality, Khartoum, Sudan, for a period 13 weeks (1st trial) and 9 weeks (2nd trial)
REVISITING SAUDI UNIVERSITY EFL LEARNERSā ENGAGEMENT TO TEACHERS WRITTEN CORRECTIVE FEEDBACK FROM A SOCIO-COGNITIVE PERSPECTIVE
The empirical studies addressing learnersā engagement to teachersā corrective feedback on their writing tasks in the Saudi EFL context as well as its impact on the studentsā improvement of writing skill are still a few.Ā Ā Therefore, the proposed research project aims to empirically address the Saudi EFL learnersā responses to teachersā written corrective feedback on their writing tasks. Addressing the EFL learnersā engagement in the teachersā written feedback is a key issue in improving learnersā writing skills. As a result, the proposed project attempts to measure Saudi learnersā engagement with their learnersā feedback from a multi-dimension perspective; learnersā uptake, affective engagement, cognitive engagement, and meta-cognitive engagement, and behavioral engagement. Investigating the learnersā responses to their teacherās feedback, the proposed project uses a socio-cognitive method that contributes to realizing the differences in EFL responses toward their teacherās corrective feedback. The proposed study relies on different sources of data that include studentsā writing assignments, semi-structured questionnaires. The sample of the study consists ofĀ 90 elementary level students belonging to the applied college at PSAU, 30 pre-intermediate students belonging to Business administration College, and 30 intermediate level students belonging to the college of humanities and sciences. The collected data reflect to what extent learners are engaged with the corrective feedback of their teachers, which can beĀ partly accounted for their ideas and experiences about the written corrective feedbackĀ and second language writing and the learning context in which the feedback was received and processed. The findings of the research projects proposes that the EFL instructors should have a deeper understanding of the studentsā cognitive and behavioral, engagement, feedback processing. This deeper understanding of studentsā responses to written correct feedback would largely contribute to improving learnersā writing skills
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