87 research outputs found

    Electronic structure and correlations of vitamin B12 studied within the Haldane-Anderson impurity model

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    We study the electronic structure and correlations of vitamin B12 (cyanocobalamine) by using the framework of the multi-orbital single-impurity Haldane-Anderson model of a transition-metal impurity in a semiconductor host. The parameters of the effective Haldane-Anderson model are obtained within the Hartree-Fock (HF) approximation. The quantum Monte Carlo (QMC) technique is then used to calculate the one-electron and magnetic correlation functions of this effective model. We observe that new states form inside the semiconductor gap found by HF due to the intra-orbital Coulomb interaction at the impurity 3d orbitals. In particular, the lowest unoccupied states correspond to an impurity bound state, which consists of states from mainly the CN axial ligand and the corring ring as well as the Co e_g-like orbitals. We also observe that the Co(3d) orbitals can develop antiferromagnetic correlations with the surrounding atoms depending on the filling of the impurity bound states. In addition, we make comparisons of the HF+QMC data with the density functional theory calculations. We also discuss the photoabsorption spectrum of cyanocobalamine.Comment: 20 pages, 14 figure

    Relationships Between Global Literacy, Global Citizenship and Social Studies

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    Global changes were accompanied with fundamental requirement for radical transformations in several areas. Individuals, in this era called globalization, are in need qualifications and equipment to enable active participation in this process. This case, parallel with the definition of active citizenship or global citizenship, implies responsibility of the individual not only for the individual but also towards the world as well (Christine, Keulemans, Gent & Spitz, 2012, p.21). Global literacy could be defined as having global knowledge, global awareness and the ability to grasp global events. It can also be described as the knowledge, access to and comprehension of current political, social and economic issues to enable the individuals to fulfill their roles as an active and global citizen. In short, it is the knowledge, recognition and comprehension of the world by the individual. Global literacy traits would result in a successful human profile who is capable to contribute to own and universal cultural environment.In the present study, the concepts of global literacy and global citizenship that are rising as trends and requirements, were scrutinized with document review technique, a qualitative research method, and the reflection of these concepts on the social studies curriculum was investigated. Keywords: Social Studies, Literacy, Global Literacy, Global Citizenship

    Genetic Diversity of Eight Domestic Goat Populations Raised in Turkey

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    The objective of this study was to determine the intra- and intergenetic diversities of eight different goat populations in Turkey including Hair, Angora, Kilis, Yayladag, Shami, Honamli, Saanen, and Alpine. A total of 244 DNA samples were genotyped using 11 microsatellites loci. The genetic differentiation between breeds was considerable as a result of the statistically significant (P0.05). Heterozygosity values ranged between 0.62 and 0.73. According to the structure and assignment test, Angora and Yayladag goats were assigned to the breed they belong to, while other breeds were assigned to two or more different groups. Because this study for the first time presented genetic data on the Yayladag goat, results of structure analysis and assigned test suggest that further analyses are needed using additional and different molecular markers

    Selection signatures in goats reveal copy number variants underlying breed-defining coat color phenotypes

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    Domestication and human selection have formed diverse goat breeds with characteristic phenotypes. This process correlated with the fixation of causative genetic variants controlling breed-specific traits within regions of reduced genetic diversity, so called selection signatures or selective sweeps. Using whole genome sequencing of DNA pools (pool-seq) from 20 genetically diverse modern goat breeds and bezoars, we identified 2,239 putative selection signatures. In two Pakistani goat breeds, Pak Angora and Barbari, we found selection signatures in a region harboring KIT, a gene involved in melanoblast development, migration, and survival. The search for candidate causative variants responsible for these selective sweeps revealed two different copy number variants (CNVs) downstream of KIT that were exclusively present in white Pak Angora and white-spotted Barbari goats. Several Swiss goat breeds selected for specific coat colors showed selection signatures at the ASIP locus encoding the agouti signaling protein. Analysis of these selective sweeps revealed four different CNVs associated with the white or tan (AWt), Swiss markings (Asm), badgerface (Ab), and the newly proposed peacock (Apc) allele. RNA-seq analyses on skin samples from goats with the different CNV alleles suggest that the identified structural variants lead to an altered expression of ASIP between eumelanistic and pheomelanistic body areas. Our study yields novel insights into the genetic control of pigmentation by identifying six functionally relevant CNVs. It illustrates how structural changes of the genome have contributed to phenotypic evolution in domestic goats

    Veteriner Biyokimya

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    Veteriner Biyokimya

    No full text
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