24 research outputs found

    Analysis for genotyping Duffy blood group in inhabitants of Sudan, the Fourth Cataract of the Nile

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    <p>Abstract</p> <p>Background</p> <p>Genetic polymophisms of the Duffy antigen receptor for the chemokines (DARC) gene successfully protected against blood stage infection by <it>Plasmodium vivax </it>infection. The Fy (a-, b-) phenotype is predominant among African populations, particularly those originating from West Africa, and it is rare among non-African populations. The aim of this study was to analyse the frequency of four Duffy blood groups based on SNPs (T-33C, G125A, G298A and C5411T) in two local tribes of Sudanese Arabs, the <it>Shagia </it>and <it>Manasir</it>, which are both from the region of the Fourth Nile cataract in Sudan.</p> <p>Methods</p> <p>An analysis of polymorphisms was performed on 217 individuals (126 representatives of the <it>Shagia </it>tribe and 91 of the <it>Manasir)</it>. Real-time PCR and TaqMan Genotyping Assays were used to study the prevalence of alleles and genotypes.</p> <p>Results</p> <p>The analysis of allelic and genotype frequency in the T-33C polymorphisms demonstrated a significant dominance of the <it>C </it>allele and <it>CC </it>genotype (OR = 0.53 [0.32-0.88]; p = 0.02) in both tribes. The G125A polymorphism is associated with phenotype Fy(a-, b-) and was identified in 83% of <it>Shagia </it>and 77% of <it>Manasir</it>. With regard to G298A polymorphisms, the genotype frequencies were different between the tribes (p = 0,002) and no single <it>AA </it>homozygote was found. Based on four SNPs examined, 20 combinations of genotypes for the <it>Shagia </it>and <it>Manasir </it>tribes were determined. The genotype <it>CC/AA/GG/CT </it>occurred most often in <it>Shagia </it>tribe (45.9%) but was rare in the <it>Manasir </it>tribe (6.6%) (p < 0.001 <it>Shagia </it>versus <it>Manasir</it>). The <it>FY*A<sup>ES </sup></it>allele was identified in both analysed tribes. The presence of individuals with the <it>FY*A/FY*A </it>genotype was demonstrated only in the <it>Shagia </it>tribe.</p> <p>Conclusion</p> <p>This is probably the first report showing genotypically Duffy-negative people who carry both <it>FY*B<sup>ES </sup></it>and <it>FY*A<sup>ES</sup></it>. The identification of the <it>FY*A<sup>ES </sup></it>allele in both tribes may be due to admixture of the non-African genetic background. Taken as a whole, allele and genotype frequencies between the <it>Shagia </it>and the <it>Manasir </it>were statistically different. However, the presence of individuals with the <it>FY*A/FY*A </it>genotype was demonstrated only in the <it>Shagia </it>tribe.</p

    Spin-Dependent Transient Effects in Electron Transport in the Quantum Dot System

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    We study the effects of the Coulomb interaction U between the electrons of opposite spins localized in the quantum dot on the time-dependent electron transport through the quantum dot coupled with two non-magnetic leads. We calculate the transient spin-dependent current generated by a pulsed bias voltage applied across the quantum dot system via the equation of motion method for appropriate correlation functions. The influence of the Coulomb interaction on the quantum coherent oscillations and beats of the current, spin current and current polarization ratio is studied. Our results indicate that the coherent beats in both the total and spin currents observed in the case of vanishing Coulomb interaction are strongly suppressed by non-zero Coulomb interaction. We also show that in the case of the pulsed bias almost fully polarized current occurs in some time windows for non-vanishing Coulomb interaction contrary to almost pure charge or spin current at vanishing U

    Effect of sample width and shape of particles on uniaxial compression of bedding of granular material

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    Celem prezentowanego projektu było badanie związku przebiegu testu jednoosiowego ściskania złoża materiału sypkiego z kształtem cząstek i szerokością prostopadłościennej komory pomiarowej. Komora miała wysokość i głębokość 0,12 m oraz szerokość (drugi wymiar poziomy) nastawny w zakresie 0 do 0,12 m. Wykonano pomiary laboratoryjne jednoosiowego ściskania na złożach bliskich kształtu sferycznego nasion grochu oraz wyraźnie niesferycznych nasion fasoli. Otrzymano wartości ilorazu naporu dla nasion fasoli w przybliżeniu 0,5, zaś dla grochu niższe, w przybliżeniu równe 0,4. Podobne tendencje były obserwowane wcześniej w badaniach nasion rzepaku i pszenicy. Wykonano symulacje numeryczne eksperymentów laboratoryjnych w złożu kul oraz zlepków trzech kul modelujących cząstki wydłużone. Analizowano przebiegi charakterystyk ilorazu naporu k od naporu pionowego. Testy numeryczne potwierdziły tendencje obserwowane w eksperymentach. Iloraz naporu w przypadku cząstek kulistych szybko rósł ze wzrostem szerokości próbki do około 2 wymiarów cząstki, po przekroczeniu tego wymiaru zmiany były niewielkie. W złożach cząstek niekulistych iloraz naporu był wyższy już w wąskich próbkach przy czym iloraz naporu rósł ze wzrostem współczynnika wydłużenia. Tak w pomiarach laboratoryjnych, jak i w symulacjach obserwowano silne fluktuacje obciążenia pionowego związane ze zmianami sieci kontaktów.Uniaxial compression characteristics of granular material were examined as influenced by the shape of particles and the width of cuboidal chamber of the apparatus. The chamber was 0.12 m high and wide, while its width was adjustable in a range from 0 to 0.12 m. Testing was performed on nearly spherical pea seeds and on clearly oblong bean seeds. Numerical simulations of laboratory tests were conducted using the discrete element method (DEM) on assemblies of spheri-cal particles of aspect ratio λ = 1.0 or on assemblies of elongated particles in the form of clusters of three coaxial spheres having aspect ratios λ = 1.3 or λ = 1.6. Asymptotic values of k in laboratory testing were found approximately 0.4 for pea seeds and approximately 0.5 for bean seeds. Similar tendencies were observed earlier in testing of wheat and rapeseeds. The results of numerical simulations were found to be in qualitative agreement with the results of laboratory testing performed. Values of pressure ratio k increased sharply with an increase in sample width up to approximately two particle diameters, and changed only slightly after surpassing this value. In assemblies of elongated particles k stabilised in narrower samples, and pressure ratio increased with an increase in λ . In laboratory testing as well as in numerical simulations strong fluctuations of values of normal load were observed, probably due to rearrangements of contact network

    Geomicrobiology of Acid Mine Drainage in the weathering zone of pyrite-bearing schists in the Rudawy Janowickie Mountains (Poland)

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    This paper presents the geomicrobiological analysis of acid water reservoirs and Acid Mine Drainage (AMD) developed in the weathering zone of pyrite-bearing schists near the closed-down pyrite mine in Wieściszowice (south-western Poland). The analysis was focused on two reservoirs characterized by different physical and chemical properties (pH, redox potential, content of sulphates and heavy metals). The study is the first thorough report on the geomicrobiological relationships taking place in the AMD setting in Wieściszowice and enables a description of the microbiological processes that significantly influence biogeochemical cycles of sulfur and iron in the analyzed water reservoirs. The reservoir water also harbors numerous big, organized microbial structures in the form of streamers. Samples of these structures were studied in detail using optical and electron microscopy, as well as microbiological cultivation and molecular methods. According to the obtained results, the slime streamers from the Wieściszowice mine are characterized by the co-occurrence of typical chemolithoautotrophic microorganisms oxidizing sulphur and iron together with sulphate reducing bacteria. The presence of these structures probably depends on the occurrence of iron (II) in the surrounding environment

    Quantum wire as a charge-qubit detector

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    Hyaluronic Acid and Radiofrequency in Patients with Urogenital Atrophy and Vaginal Laxity

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    Vaginal laxity (VL) and genitourinary syndrome of menopause (GSM), as well as aesthetic changes in the vulvar skin, often occur together and cause physical, psychological, and functional problems for women and their partners. The current study evaluated the efficacy of a nonsurgical radiofrequency device (RF) procedure combined with hyaluronic acid (HA) injection into the skin of the labia majora on clinical, histological, and aesthetic levels. Twenty women with GSM and VL, aged between 36 and 72 (mean age 53.4), were treated with bipolar RF SECTUM, vaginal and vulvar application, as well as with a hyaluronic acid (HA) injection into the skin of the labia majora. The Vaginal Laxity Questionnaire (VLQ), Vaginal Health Index (VHI), and Female Sexual Function Index (FSFI) were used to examine the clinical effects of the operations. The Global Aesthetic Improvement Scale was utilized to measure patient satisfaction. On a histochemical level, the concentrations of elastin and collagen in the vaginal wall and vulvar skin were examined. Results: There was significantly higher patient satisfaction and a considerable clinical improvement across all areas of analysis. On the histochemical level, elastin and collagen fiber concentration increased after the treatment protocol both in the vulvar skin and in the vaginal wall: elastin in the vaginal wall, 11.4%, and in the vulvar skin, 61%; collagen in the vaginal wall, 26%, and in the vulvar skin, 27%. The current study demonstrated the efficacy and safety of this nonsurgical RF procedure combined with a hyaluronic acid (HA) injection into the skin of the labia majora on clinical, histochemical, and aesthetic levels
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