3,736 research outputs found

    Social media usage in academic research

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    Recently researchers have used “conversation prism” and “social media prisma”, to consolidate social medias with respect to their use. Although both identified 25 types, having average five examples each, they did not identify contribution of each type in academic research. Moreover some of mentioned social services had been suspended or changed. In this paper we attempt to access each social media mentioned in conversation prism in order to first, identify services that are operational to date, services which have suspended and those which have changed during course of time. Second, we compare number of publications associated with each social media, in order to identify which social media has contributed most to academic research. Third, we attempt to find correlation between number of publications and development tools provided by respective social applications. Fourth, social medias are ranked with respect to number of times other social medias share content with respective social application. It was found that out of 168 social applications, 10% changed their service objective while 13% were suspended. Among all social application, AMAZON had highest i.e. 147,000 number of citations on Google scholar whereas 90.7% of total citations were contributed by top 30 social medias. For developers, 22 out of top 30 social medias provided developer options in form of either application programming interface (API) or software development kits (SDK) and Facebook was found to be most cross referred social media based on content sharing. Finally conclusion and future work of study is presented

    Dilatonic interpolation between Reissner-Nordstrom and Bertotti-Robinson spacetimes with physical consequences

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    We give a general class of static, spherically symmetric, non-asymptotically flat and asymptotically non-(anti) de Sitter black hole solutions in Einstein-Maxwell-Dilaton (EMD) theory of gravity in 4-dimensions. In this general study we couple a magnetic Maxwell field with a general dilaton potential, while double Liouville-type potentials are coupled with the gravity. We show that the dilatonic parameters play the key role in switching between the Bertotti-Robinson and Reissner-Nordstr\"om spacetimes. We study the stability of such black holes under a linear radial perturbation, and in this sense we find exceptional cases that the EMD black holes are unstable. In continuation we give a detailed study of the spin-weighted harmonics in dilatonic Hawking radiation spectrum and compare our results with the previously known ones. Finally, we investigate the status of resulting naked singularities of our general solution when probed with quantum test particles.Comment: 27 pages, 4 figures, to appear in CQG

    Konstruksi Pustaka Genom Kakao (Theobroma Cacao L.) Untuk Sekuensing Genom Total Menggunakan Next Generation Sequencing HiSeq2000

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    Pemuliaan kakao secara konvensional memerlukan waktu panjang (10-15 tahun). Pemanfaatan marka DNA akan memperpendek siklus pemuliaan kakao. Tujuan penelitian ini adalah mengkonstruksi pustaka genom tiga genotipe kakao yang dapat digunakan untuk sekuensing genom total kakao menggunakan NGS HiSeq2000 dan mendapatkan data resekuen genom total tiga genotipe kakao. Bahan tanaman terdiri dari tiga klon unggul kakao (ICCR02, ICCR04, dan SUL02) diperoleh dari Balittri, Pakuwon. DNA genomik diisolasi dari daun muda sebagai bahan konstruksi pustaka genom total. Sekuensing pustaka dilakukan pada mesin HiSeq2000 mengikuti protokol dari Illumina. Pustaka genom yang telah berhasil dikonstruksi berukuran 300 pasang basa (bp) masing-masing dengan konsentrasi 14,70 ng/µL (ICCR02), 15,20 ng/µL (ICCR04), dan 12,90 ng/µL (SUL02). Ukuran dan konsentrasi pustaka genom yang dihasilkan sangat ideal untuk sekuensing menggunakan HiSeq2000. Sekuensing ketiga genom menghasilkan data sekuen 52,9 x 109 bp. Klaster DNA pustaka genom memiliki nilai Q scores>30 (75,0%) dengan tingkat kesalahan pembacaan basa rendah (1,47%). Nilai densitas klaster, persen klaster PF, intensitas basa, persen phasing, dan persen prephasing menunjukkan kualitas klaster pustaka genom ketiga genotipe kakao termasuk kategori pustaka ideal. Data sekuen yang dihasilkan juga sangat ideal untuk identifikasi marka SNP genom kakao. Koleksi marka SNP digunakan untuk identifikasi gen pengendali karakter penting kakao dan pemuliaan berbasis marka DNA untuk memperpendek siklus pemuliaan kakao. Genomic Library Construction Of Cocoa (Theobroma Cacao L.) For Whole Genome Sequensing Using A Next Generation Sequencer Hiseq2000Conventional cocoa breeding is slow and takes about 10-15 years to complete a breeding cycle. Applying genomic technology using DNA markers will significantly decrease cocoa breeding cycle. The objectives of this study were to construct cocoa whole genome genomic libraries to be used for resequencing the whole genome of cocoa and obtain whole genome resequence data of three cocoa genotypes. Three Indonesian cocoa genotypes (ICCR02, ICRR04, and SUL02) were used. DNA genomic was isolated from young leaf and used to construct genomic DNA libraries and generate DNA clusters. DNA clusters were sequenced using a HiSeq2000 platform. The whole genome libraries of the cocoa genotypes were successfully constructed. The library size was 300 bp with concentrations of 14.70 ng/µL (ICCR02), 15.20 ng/µL (ICCR04), and 12.90 ng/µL (SUL02), respectively. The genomic library size and concentrations are suitable for sequencing study using the NGS HiSeq2000. Total sequencing output obtained was 52.9 x 109 bp. The genomic library clusters resulted during the sequencing process demonstrated the Q scores > 30 of 75.0% with low error sequencing rate of 1.47%. Cluster densities, percentage of cluster PF, base intensity, and percentage of phasing and prephasing indicated the cluster quality of the genomic libraries is classified as an ideal one to be used for resequencing study using NGS HiSeq2000. The resequence data were ideal for SNP marker discovery. SNP markers are used to identify economically important genes of cocoa and marker-aided cocoa breeding to decrase the cocoa breeding cycle

    Genomic Variation of Five Indonesian Cacao (Theobroma Cacao L.) Varieties Based on Analysis Using Next Generation Sequencing

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    Indonesian cacao productivity is still low mainly due to the lack availability of superior cacao planting materials. A new breeding method is necessary to expedite cacao yield improvement programs. To date, no study has yet been done to characterize Indonesian cacao varieties at the whole genome level. The objective of this study was to characterize genomic variation of five superior Indonesian cacao varieties using next-generation sequencing. Genetic materials used were five Indonesian cacao varieties, i.e. ICCRI2, ICCRI3, ICCRI4, SUL2 and ICS13. Genome sequences were mapped to the cacao reference genome sequence of Criollo variety. Sequence alignment and genomic variation discovery were done using Bowtie2 and mpileup software of Samtools, respectively. A total of 2,326,088 single nucleotide polymorphisms (SNPs) and 362,081 insertions and deletions (Indels) were obtained from this study. In average, a DNA variant was identified in every 121 nucleotides of the genome sequence. Most of the DNA variants were located outside the genes. Only 347,907 SNPs and Indels (13.18%) were located within protein coding region (exon). Among the DNA variations within exon, 188,949 SNPs caused missense mutation and 1,535 SNPs induced nonsense mutation. Unique gene-based SNPs were also discovered from this study that can be used as fingerprints for the particular cacao variety. The DNA variants obtained were excellent DNA marker resources to support cacao breeding programs. The SNPs discovered are useful as materials for genome-wide SNP chip development to be used for gene and QTL tagging of important traits for expediting national cacao breeding program

    Spin Orientation of Holes in Quantum Wells

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    This paper reviews the spin orientation of spin-3/2 holes in quantum wells. We discuss the Zeeman and Rashba spin splitting in hole systems that are qualitatively different from their counterparts in electron systems. We show how a systematic understanding of the unusual spin-dependent phenomena in hole systems can be gained using a multipole expansion of the spin density matrix. As an example we discuss spin precession in hole systems that can give rise to an alternating spin polarization. Finally, we discuss the qualitatively different regimes of hole spin polarization decay in clean and dirty samples.Comment: 14 pages, 8 figure

    Condensates beyond mean field theory: quantum backreaction as decoherence

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    We propose an experiment to measure the slow log(N) convergence to mean-field theory (MFT) around a dynamical instability. Using a density matrix formalism, we derive equations of motion which go beyond MFT and provide accurate predictions for the quantum break-time. The leading quantum corrections appear as decoherence of the reduced single-particle quantum state.Comment: 4 pages, 4 figures, submitted to Phys. Rev. Let

    Observation of Individual Josephson Vortices in YBCO Bicrystal Grain-boundary Junctions

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    The response of YBCO bicrystal grain-boundary junctions to small dc magnetic fields (0 - 10 Oe) has been probed with a low-power microwave (rf) signal of 4.4 GHz in a microwave-resonator setup. Peaks in the microwave loss at certain dc magnetic fields are observed that result from individual Josephson vortices penetrating into the grain-boundary junctions under study. The system is modeled as a long Josephson junction described by the sine-Gordon equation with the appropriate boundary conditions. Excellent quantitative agreement between the experimental data and the model has been obtained. Hysteresis effect of dc magnetic field is also studied and the results of measurement and calculation are compared.Comment: 11 pages, 4 figure

    Statistical Mechanics of Kinks in (1+1)-Dimensions

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    We investigate the thermal equilibrium properties of kinks in a classical Ď•4\phi^4 field theory in 1+11+1 dimensions. The distribution function, kink density, and correlation function are determined from large scale simulations. A dilute gas description of kinks is shown to be valid below a characteristic temperature. A double Gaussian approximation to evaluate the eigenvalues of the transfer operator enables us to extend the theoretical analysis to higher temperatures where the dilute gas approximation fails. This approach accurately predicts the temperature at which the kink description breaks down.Comment: 8 pages, Latex (4 figures available on request), LA-UR-92-399
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