| 1. |
- Ranjbar, M., et al.
(författare)
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CoFeB-Based Spin Hall Nano-Oscillators
- 2014
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Ingår i: IEEE Magnetics Letters. - 1949-307X .- 1949-3088. ; 5, s. 3000504-
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Tidskriftsartikel (refereegranskat)abstract
- We demonstrate magnetization auto-oscillations driven by pure spin currents in spin Hall nano-oscillators based on CoFeB/Pt bilayers. Despite the very low anisotropic magnetoresistance of CoFeB, a substantial microwave signal power can be detected, even at room temperature, indicating that a sizable spin wave amplitude is generated. Spin torque ferromagnetic resonance measurements reveal that the generated auto-oscillation frequency lies below the ferromagnetic resonance frequency of CoFeB and is therefore well described by a self-localized spin wave bullet mode.
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| 2. |
- Schrey, A W, et al.
(författare)
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Broad-scale latitudinal patterns of genetic diversity among native European and introduced house sparrow (Passer domesticus) populations.
- 2011
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Ingår i: Molecular Ecology. - 0962-1083. ; 20, s. 1133-1143
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Tidskriftsartikel (refereegranskat)abstract
- Introduced species offer unique opportunities to study evolution in new environments, and some provide opportunities for understanding the mechanisms underlying macroecological patterns. We sought to determine how introduction history impacted genetic diversity and differentiation of the house sparrow (Passer domesticus), one of the most broadly distributed bird species. We screened eight microsatellite loci in 316 individuals from 16 locations in the native and introduced ranges. Significant population structure occurred between native than introduced house sparrows. Introduced house sparrows were distinguished into one North American group and a highly differentiated Kenyan group. Genetic differentiation estimates identified a high magnitude of differentiation between Kenya and all other populations, but demonstrated that European and North American samples were differentiated too. Our results support previous claims that introduced North American populations likely had few source populations, and indicate house sparrows established populations after introduction. Genetic diversity also differed among native, introduced North American, and Kenyan populations with Kenyan birds being least diverse. In some cases, house sparrow populations appeared to maintain or recover genetic diversity relatively rapidly after range expansion (<50 years; Mexico and Panama), but in others (Kenya) the effect of introduction persisted over the same period. In both native and introduced populations, genetic diversity exhibited large-scale geographic patterns, increasing towards the equator. Such patterns of genetic diversity are concordant with two previously described models of genetic diversity, the latitudinal model and the species diversity model.
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| 3. |
- El Serafi, Ibrahim Taher, et al.
(författare)
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Effect of interleukin-6 and insulin resistance on early virological response of Egyptian chronic hepatitis C patients to combined pegylated interferon plus ribavirin therapy
- 2013
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Ingår i: Egyptian Liver Journal. - Heidelberg, Germany : Wolters Kluwer. - 2090-6218. ; 3:2, s. 21-27
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Tidskriftsartikel (refereegranskat)abstract
- Background and aim: Response to hepatitis C virus (HCV)-specific therapy is variable but might be influenced by host factors. We studied whether interleukin-6 (IL-6) level, IL-6–174G>C gene polymorphism, and insulin resistance affect the response to antiviral treatment in HCV-infected patients.Patients and methods: Fifty-five chronic hepatitis C patients and 13 healthy individuals as controls were included in this study. Liver function tests, HCV RNA titer, ultrasonography, and histopathological examination of liver tissues were performed for all patients. Pretreatment plasma IL-6 levels and homeostasis model assessment-insulin resistance were estimated. The IL-6–174G>C polymorphism was detected by the PCR/RFLP method. After 12 weeks of combined pegylated interferon-α and ribavirin therapy, patients were classified into responders or nonresponders according to whether they achieved an early virological response.Results: The responders had significantly high IL-6 levels (P=0.01), low mean stage of fibrosis (P=0.03), and low viral load (P=0.04) compared with nonresponders. Although not significant, patients with the IL-6–174 CC genotype reported a higher response rate (81%) compared with those with the CG genotype (50%) and GG genotype (62%). IL-6 level at a cutoff point of 2.15 pg/ml had 81.1% sensitivity and 72.7% specificity and showed significant relation with early virological response (P=0.04).Conclusion: Estimation of basal IL-6 level could be used as a predictor of response to pegylated interferon-α and ribavirin therapy in CHC patients.
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| 4. |
- El Tahir, Bashir Awad, et al.
(författare)
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Nutrient Balances as Indicators of Sustainability in acacia senegal Land use Systems in the Semi-arid Zone of North Kordofan, Sudan
- 2013
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Ingår i: Standard Scientific Research and Essays. - 2310-7502. ; 1:5, s. 93-112
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Tidskriftsartikel (refereegranskat)abstract
- The objectives of this study were: (1) to assess nutrient flows and balances at land management systems and cropping seasons levels, and (2) to determine rate of nutrient depletion. The study was conducted in dry lands of Northern Kordofan, Sudan, at El Demokeya Forest Reserve (lat.13° 16′ ′′ ′N; long. 30° 29′ ′′ ′E, and alt. 560 m), over three cropping seasons (2002, 2003 and 2004). Flows and balances of organic carbon (OC), nitrogen (N), phosphorous (P) and potassium (K) in pure and intercropped sorghum, roselle and grasses with Acacia senegal at low- and high-tree density (LD 266 and HD 433 trees ha -1 , respectively) were investigated. Sources of nutrient inflows were organic matter (OM) from trees, gum Arabic, crop roots, atmospheric deposition, and N2fixation. Outflows were harvested products, crop residues, leaching, gaseous losses and wind erosion. Nutrient balances were positive in grass systems, but negative in pure sorghum and roselle. Large variations exist between inter cropped sorghum and roselle systems. Nutrient balances were positive during the poor cropping season (2002), while negative during the good season (2003). Nutrient depletion was severe for all studied nutrients in pure sorghum and roselle, but P depletion was remarkably more severe in roselle systems. For all systems, P availability is the major determinant of sustainability. The study demonstrated that OM was essential for positive nutrient balances. Hence, intercropping is considered as an appropriate option to enhance soil fertility. Ways for adjusting the negative balancesin the context of sustainability were suggested.
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| 5. |
- Kovacs, Gabor G., et al.
(författare)
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An antibody with high reactivity for disease-associated α-synuclein reveals extensive brain pathology
- 2012
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Ingår i: Acta Neuropathologica. - : Springer Science and Business Media LLC. - 0001-6322 .- 1432-0533. ; 124:1, s. 37-50
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Tidskriftsartikel (refereegranskat)abstract
- α-Synuclein is the major protein associated with Lewy body dementia, Parkinson's disease and multiple system atrophy. Since α-synuclein is present in the brain in physiological conditions as a presynaptic protein, it is crucial to characterize disease-associated modifications to develop an in vivo biomarker. With the aim to develop antibodies showing high specificity and sensitivity for disease-associated α-synuclein, synthetic peptides containing different amino acid sequences were used for immunization of mice. After generation of α-synuclein aggregates, ELISA and immunoblotting were used to test the specificity of antibodies. Tissue microarray sections originating from different human α-synucleinopathies were used to compare immunostaining with other, commercially available antibodies. Immunization of mice with the peptide TKEGVVHGVATVAE (amino acid 44-57 of α-synuclein) resulted in the generation of a monoclonal antibody (5G4), which was able to bind aggregated α-synuclein preparation in sandwich ELISA or coated on magnetic beads. 5G4 proved to be superior to other antibodies in comparative immunohistochemical studies by revealing more widespread and distinct α-synuclein pathology. Immunoblotting of human brain tissue revealed an additional band seen in dementia with Lewy bodies, whereas the band representing monomeric α-synuclein was very weak or lacking. In summary, the 5G4 antibody is most promising for re-evaluation of archival material and may offer new perspective for the development of in vivo diagnostic assays for detecting disease-associated α-synuclein in body fluids.
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| 6. |
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