577 research outputs found

    Inelastic scattering in a monolayer graphene sheet; a weak-localization study

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    Charge carriers in a graphene sheet, a single layer of graphite, exhibit much distinctive characteristics to those in other two-dimensional electronic systems because of their chiral nature. In this report, we focus on the observation of weak localization in a graphene sheet exfoliated from a piece of natural graphite and nano-patterned into a Hall-bar geometry. Much stronger chiral-symmetry-breaking elastic intervalley scattering in our graphene sheet restores the conventional weak localization. The resulting carrier-density and temperature dependence of the phase coherence length reveal that the electron-electron interaction including a direct Coulomb interaction is the main inelastic scattering factor while electron-hole puddles enhance the inelastic scattering near the Dirac point.Comment: 12 pages, 3 figures, submitted to PR

    Pseudogap Behavior Revealed in Interlayer Tunneling in Overdoped Bi2_2Sr2_2CaCu2_2O8+x_{8+x}

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    We report heating-compensated interlayer tunneling spectroscopy (ITS) performed on stacks of overdoped Bi2_2Sr2_2CaCu2_2O8+x_{8+x} intrinsic junctions, where most of bias-induced heating in the ITS was eliminated. The onset temperature of the pseudogap (PG), revealed in the hump structure of the electronic excitation spectra, reached nearly room temperature for our overdoped intrinsic junctions, which represented the genuine PG onset. At a temperature below but close to TcT_c, both the superconducting coherence peak and the pseudogap hump coexisted, implying that the two gaps are of separate origins. The hump voltage increased below TcT_c, following the superconducting gap voltage, which led to a conclusion that the hump structure below TcT_c in our ITS arose from the combined contribution of the quasiparticle spectral weights of two different characters; one of the superconducting state and another of the PG state near the antinodal region.Comment: accepted in Phys. Rev.

    Coupling characteristics of surface modes in truncated two-dimensional photonic crystals

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    On 1 February, 1994 the Republic of Austria concluded the Accession Treaty and on 1 January, 1995 became a full member of the European Union. Membership obliged Austrians to ‘provide’ the Community with appropriate personnel to take up different posts in various EU authorities, as well as in the European Parliament. The most important issue was to alter particular statutory regulations and the Austrian Constitution to adjust to the new situation.The paper aims at presenting the Austrian solutions in this matter in the context of European Union law, with particular emphasis on regulations which are uncommon or specific to the Republic of Austria. The matter of interest is the constitutional practice of EU member states and the reader’s perspective is taken into account. The latter approach not only evaluates the Austrian solutions in the context of the electoral law to the European Parliament contained in the Election Code, but could also suggest some ideas in regard to prospective amendments. The authors would, in particular, like to pay attention to two issues: the lowering of the voting age, and the single constituency electoral system. The Austrian solutions might be valuable to refer to in the countries where a system of correspondence voting is just being introduced. These resolutions are particularly interesting taking into consideration prospective, possible amendments to the electoral laws of the EU member states.Republika Austrii, 1 lutego 1994 r. podpisała traktat akcesyjny i z dniem 1 stycznia 1995 r. stała się pełnoprawnym członkiem Unii Europejskiej. Członkostwo zobowiązało Austriaków do “dostarczenia” Wspólnocie odpowiednich osób do objęcia różnych stanowisk w różnych unijnych organach. Nie inaczej było także w przypadku Parlamentu Europejskiego. Ważnym aspektem stało się dostosowanie poszczególnych norm ustawowych i własnej konstytucji do nowych rozwiązań. Celem niniejszego opracowania jest właśnie przedstawianie austriackich rozwiązań w tym temacie na tle rozwiązań europejskich, ze szczególnym uwzględnieniem unormowań rzadko spotykanych lub wręcz odrębności sytemu Republiki Austrii. Rzecz wydaje się być interesująca zarówno z punktu widzenia praktyki ustrojowej państw członkowskich Unii Europejskiej, jak i z punktu widzenia czytelnika. To drugie podejście pozwoli na ocenę austriackich rozwiązań na tle niedawno wprowadzonej ordynacji wyborczej do PE zawartej w Kodeksie Wyborczym, ale również może podsunąć pewne pomysły, co do przyszłych nowelizacji. Autorzy zwrócili szczególną uwagę na dwa rozwiązania: obniżenie cenzusu wieku czynnego prawa wyborczego oraz jednookręgowy system wyborczy. Austriackie doświadczenia mogą być również pomocne państwom, które wprowadzają możliwość głosowania korespondencyjnego. Są to propozycje szczególnie interesujące z punktu widzenia przyszłych, możliwych nowelizacji systemów wyborczych państw członkowskich

    A DNA barcode library of the beetle reference collection (Insecta: Coleoptera) in the National Science Museum, Korea

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    AbstractColeoptera is a group of insects that are most diverse among insect resources. Although used as indicator species and applied in developing new drugs, it is difficult to identify them quickly. Since the development of a method using mitochondrial DNA information for identification, studies have been conducted in Korea to swiftly and accurately identify species. The National Science Museum of Korea (NSMK) has been collecting and morphologically identifying domestic reference insects since 2013, and building a database of DNA barcodes with digital images. The NSMK completed construction of a database of digital images and DNA barcodes of 60 beetle species in the Korean National Research Information System. A total of 179 specimens and 60 species were used for the analysis, and the averages of intraspecific and interspecific variations were 0.70±0.45% and 26.34±6.01%, respectively, with variation rates ranging from 0% to 1.45% and 9.83% to 56.23%, respectively

    Prevalence of human papillomavirus infection and genotype distribution among high-risk Korean women for prospecting the strategy of vaccine development

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    We investigated the prevalence of human papillomavirus (HPV) infection and the distribution of high-risk HPV genotypes among 2,308 high-risk Korean women to predict how much the current prophylactic HPV vaccines might affect the prevention of cervical cancer in Korea. HPV DNA was detected in 939 women (40.7%) but only one-third of women were positive for HPV-16 and/or HPV-18, the genotypes used for developing the HPV vaccines. Thus, the development of area-specific HPV vaccines based on dominant HPV genotypes in our country is needed for preventing HPV infection and the development of premalignant lesions in the cervix of Korean women

    Whole Genome Analysis of the Red-Crowned Crane Provides Insight into Avian Longevity

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    The red-crowned crane (Grus japonensis) is an endangered, large-bodied crane native to East Asia. It is a traditional symbol of longevity and its long lifespan has been confirmed both in captivity and in the wild. Lifespan in birds is known to be positively correlated with body size and negatively correlated with metabolic rate, though the genetic mechanisms for the red-crowned crane's long lifespan have not previously been investigated. Using whole genome sequencing and comparative evolutionary analyses against the grey-crowned crane and other avian genomes, including the long-lived common ostrich, we identified red-crowned crane candidate genes with known associations with longevity. Among these are positively selected genes in metabolism and immunity pathways (NDUFA5, NDUFA8, NUDT12, SOD3, CTH, RPA1, PHAX, HNMT, HS2ST1, PPCDC, PSTK CD8B, GP9, IL-9R, and PTPRC). Our analyses provide genetic evidence for low metabolic rate and longevity, accompanied by possible convergent adaptation signatures among distantly related large and long-lived birds. Finally, we identified low genetic diversity in the red-crowned crane, consistent with its listing as an endangered species, and this genome should provide a useful genetic resource for future conservation studies of this rare and iconic species
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