995 research outputs found

    Mackey functions, induction from restriction functors and coinduction from transfer functors

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    Cataloged from PDF version of article.Boltje's plus constructions extend two well-known constructions on Mackey functors, the fixed-point functor and the fixed-quotient functor. In this paper, we show that the plus constructions are induction and coinduction functors of general module theory. As an application, we construct simple Mackey functors from simple restriction functors and simple transfer functors. We also give new proofs for the classification theorem for simple Mackey functors and semisimplicity theorem of Mackey functors. © 2007 Elsevier Inc. All rights reserved

    A Tate cohomology sequence for generalized Burnside rings

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    Cataloged from PDF version of article.We generalize the fundamental theorem for Burnside rings to the mark morphism of plus constructions defined by Boltje. The main observation is the following: If D is a restriction functor for a finite group G, then the mark morphism φ : D+ → D+ is the same as the norm map of the Tate cohomology sequence (over conjugation algebra for G) after composing with a suitable isomorphism of D+. As a consequence, we obtain an exact sequence of Mackey functors 0 → over(Ext, ̂)γ- 1 (ρ, D) → D+ over({long rightwards arrow}, φ) D+ → over(Ext, ̂)γ0 (ρ, D) → 0 where ρ denotes the restriction algebra and γ denotes the conjugation algebra for G. Then, we show how one can calculate these Tate groups explicitly using group cohomology and give some applications to integrality conditions. © 2008 Elsevier B.V. All rights reserved

    Synthesis of Graphene on Gold

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    Here we report chemical vapor deposition of graphene on gold surface at ambient pressure. We studied effects of the growth temperature, pressure and cooling process on the grown graphene layers. The Raman spectroscopy of the samples reveals the essential properties of the graphene grown on gold surface. In order to characterize the electrical properties of the grown graphene layers, we have transferred them on insulating substrates and fabricated field effect transistors. Owing to distinctive properties of gold, the ability to grow graphene layers on gold surface could open new applications of graphene in electrochemistry and spectroscopy.Comment: 8 pages, 4 figure

    Fundamental structure of Fresnel diffraction: natural sampling grid and the fractional Fourier transform

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    Cataloged from PDF version of article.Fresnel integrals corresponding to different distances can be interpreted as scaled fractional Fourier transformations observed on spherical reference surfaces. We show that by judiciously choosing sample points on these curved reference surfaces, it is possible to represent the diffracted signals in a nonredundant manner. The change in sample spacing with distance reflects the structure of Fresnel diffraction. This sampling grid also provides a simple and robust basis for accurate and efficient computation, which naturally handles the challenges of sampling chirplike kernels. © 2011 Optical Society of America

    BIOLOGY OF SILKWORM (BOMBYX MORI) IN TURKEY

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    According to oldest records the first time silkworm was cultivated and silk was obtained from cocoonat China. Silkworm eggs and mulberry seeds was brought to Istanbul illegally the year 552 at age of Byzantine Empire although China kept it as a secret. It started to spread Marmara regione specially Bursa and It’s neighbourhood. Then it was spreaded to allover the world. Sericulture have been economical, cultural and traditional cultivating sector at Turkey for 1500 years. Silkworm is cultivated at about 30 countries that include Turkey. Silk fiber is superior to other fibers in terms of stability, flexibility and brightness. Amount of need is approximately twice the amount of cultivating. In whole world Turkish silk fiber quality is at second rank after japanese silk. Silkworm is a general term that includes a range from worm to the butterfly. Silkworm is a kind of night butterflies. Butterflies are light cream colour have chubby bodies and have soft feathers. Wingspan is about 4-5 cm. Butterfly have lost flying ability because of domestication also have 2 or 3 days life and at that period doesn’t feed and doesn’t fly. Silkworm is fed with mulberry leaves. One cocoon is made from a single silk fiber it’s lenght is 800 meters. Real silkworm named “Bombyx Mori L” is bred at mulberry tree which is cultivated at China is white breed. Bombyx Mori L silkworm producesbest silk fiber amoung other genus and it is most special genus cultivated

    Parasitic Appendicitis From Past to Present in Turkey

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    Background: Understanding the etiology of appendicitis is important for developing effective treatments the rela­tionship between parasitic appendicitis and various socio-cultural factors were examined, particu­larly with respect to the incidence of literacy. The aim of the article was to research the relations between para­sitic appendicitis and literacy ratio in population.Methods: Cases of parasitic appendicitis resulting in surgery performed at Buca Seyfi Demirsoy Large State Hospital Surgery Clinic between 2002 and 2009 were retrospectively reviewed and classified accord­ing to age, sex, type of parasite, morbidity, and mortality. Studies conducted in different regions of Turkey as well as in other countries were reviewed to determine if there was a relationship between para­sitic appendicitis and literacy. Results: Of the 1,969 appendectomy cases reviewed, nine were classified as parasitic appendicitis (0.45%). Enterobius vermicularis was observed in seven cases and Taenia spp. in two. The average age was 26.4 yr. No morbidity or mortality was found.Conclusion: The data were compared with a retrospective review of studies conducted in the same regions and a decrease in the rate of parasitic appendicitis was observed during the period between the two re­views. It was determined that a low literacy rate was associated with an increase in the incidence of para­sitic appendicitis. Observations made between different countries also produced similar results. In coun­tries where the incidence of parasitic appendiciticis was greater than 1.5%, the literacy rate was less than 88%. To avoid appendectomy resulting from parasites, it is important to increase education and literacy. In some areas, individuals with appendicitis undergo surgery due to a lack of education or poor literacy

    Distribution of mast cells in lung tissues of rats exposed to biomass smoke

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    This study was designed to evaluate the distribution of mast cells in the lung tissues of rats exposed to biomass  smoke. Fifty six female Wistar albino adult rats were used. They were divided into two experimental groups  (control and biomass smoke-treated), each containing 28 animals. Control rats were not exposed to the  biomass smoke at any time during the experiment. Rats in the treatment group were exposed daily (one hour)  to biomass smoke for 3, 6 or 9 months. Lung tissues samples were obtained under deep anesthesia from the  randomly selected 7 animals in both groups. Lung tissues were fixed in Mota’s fixative (BLA) for 24 h and  embedded in paraffin. Sections of 6 μm thickness were cut and stained with 0.5% toluidine blue in 0.5 N  hydrochloric acid at pH 0.5 for 30 min. The numbers of mast cell in lung tissues of the animals exposed to  the biomass for 6 or 9 months were significantly (P<0.05) higher than controls. This study showed that long  term exposure to biomass smoke was associated with the increased number of mast cells in the lung.
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