2,313 research outputs found

    Preparation of Gold Nanoparticle–DNA Conjugates

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    This unit describes the preparation of conjugates between nanometer‐scale gold particles and synthetic oligonucleotides. Oligonucleotide‐functionalized gold nanoparticles are finding increased use in both the construction of complex, tailored nanostructures and the optimization of DNA sequence analysis. The protocols in this unit outline the synthesis, purification, and characterization of nanoparticle‐DNA conjugates for applications in nanotechnology and biotechnology. Separate procedures are presented for nanoparticles functionalized with just one or a few oligonucleotide strands and for nanoparticles functionalized with a dense layer of oligonucleotide strands. The different physical and chemical properties of these two types of conjugates are discussed, as are their stability and utility in different environments.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/143655/1/cpnc1202.pd

    Detection of horizontal transfer of individual genes by anomalous oligomer frequencies

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    Background Understanding the history of life requires that we understand the transfer of genetic material across phylogenetic boundaries. Detecting genes that were acquired by means other than vertical descent is a basic step in that process. Detection by discordant phylogenies is computationally expensive and not always definitive. Many have used easily computed compositional features as an alternative procedure. However, different compositional methods produce different predictions, and the effectiveness of any method is not well established. Results The ability of octamer frequency comparisons to detect genes artificially seeded in cyanobacterial genomes was markedly increased by using as a training set those genes that are highly conserved over all bacteria. Using a subset of octamer frequencies in such tests also increased effectiveness, but this depended on the specific target genome and the source of the contaminating genes. The presence of high frequency octamers and the GC content of the contaminating genes were important considerations. A method comprising best practices from these tests was devised, the Core Gene Similarity (CGS) method, and it performed better than simple octamer frequency analysis, codon bias, or GC contrasts in detecting seeded genes or naturally occurring transposons. From a comparison of predictions with phylogenetic trees, it appears that the effectiveness of the method is confined to horizontal transfer events that have occurred recently in evolutionary time. Conclusions The CGS method may be an improvement over existing surrogate methods to detect genes of foreign origin

    Self-Optimization of Internet Services with Dynamic Resource Provisioning

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    Self-optimization through dynamic resource provisioning is an appealing approach to tackle load variation in Internet services. It allows to assign or release resources to/from Internet services according to the varying load. However, dynamic resource provisioning raises several challenges among which: (i) How to plan a good capacity of an Internet service, i.e.~a necessary and sufficient amount of resource to handle the Internet service workload, (ii) How to manage both gradual load variation and load peaks in Internet services, (iii) How to prevent system oscillations in presence of potentially concurrent dynamic resource provisioning, and (iv) How to provide generic self-optimization that applies to different Internet services such as e-mail services, streaming servers or e-commerce web systems. This paper precisely answers these questions. It presents the design principles and implementation details of a self-optimization autonomic manager. It describes the results of an experimental evaluation of the self-optimization manager with a realistic e-commerce multi-tier web application running in a Linux cluster of computers. The experimental results show the usefulness of self-optimization in terms of end-user's perceived performance and system's operational costs, with a negligible overhead

    PENGAMATAN AKTIFITAS KASIR DALAM MELAKUKAN PELAYANAN DAN PENJUALAN PRODUK DI KENTUCKY FRIED CHICKEN CABANG MERDEKA BANDUNG

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    ABSTRAK Taton Henrikus Pasaribu, 009600051, “Pengamatan Aktifitas Kasir Dalam Melakukan Pelayanan Dan Penjualan Produk Di Kentucky Fried Chicken Cabang Merdeka Bandung”. Laporan tugas Akhir. Institut Manajemen Telkom, Sekolah Administrasi Bisnis dan Keuangan, Program Diploma III, Program Studi DIII Manajemen Pemasaran, 2012, di bawah bimbingan Bapak Drs. Dadang Iskandar, MM. Laporan tugas akhir ini bertujuan: 1. Untuk mengetahui prosedur yang dilakukan oleh kasir saat berhadapan dengan konsumen. 2. Untuk mengetahui bagaimana selling skill kasir dalam melakukan jobdesc-nya sebagai kasir pada saat melakukan penjualan produk-produk KFC. 3. Untuk mengetahui apakah menurut mistery shopper petugas kasir di KFC Merdeka – Bandung telah mengikuti prosedur pelayanan dengan baik atau belum. 4. Untuk mengetahui hambatan-hambatan petugas kasir dalam melakukan penjualan produk di KFC Merdeka-Bandung Metode pengumpulan data adalah metode survey yaitu dengan cara wawancara, observasi lapangan, dan observasi kepustakaan. Berdasarkan hasil observasi,diperoleh kesimpulan: 1. Prosedur yang dilakukan oleh kasir saat berhadapan dengan konsumen adalah metode 7 pelayanan. 2. Selling skill kasir dalam melakukan jobdesc-nya sebagai kasir saat melakukan penjualan produk-produk KFC berjalan dengan baik sesaui jobdesc-yang telah ditetapkan, dan seluruh kasir KFC Merdeka memiliki selling skill yang terbilang baik. 3. menurut Mistery Shopper petugas kasir di KFC Merdeka Bandung telah mengikuti prosedur pelayanan cdengan baik walaupun beberapa kali melewatkan poin – poin tertentu. 4. Hambatan- hambatan petugas kasir dalam melakukan penjualan produk d KFC merdeka Bandung secara umum dipengaruhi oleh masalah pribadi dan kurangnya konsumen yang datang di bulan-bulan tertentu

    Phosphines, carbÚnes N-hétérocycliques (NHCs) et nouveaux précurseurs de NHCs pour la catalyse organique de réactions (macro)moléculaires

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    Dans ce travail de thĂšse, plusieurs approches ont Ă©tĂ© dĂ©veloppĂ©es pour permettre une utilisation plus variĂ©e des carbĂšnes N-hĂ©tĂ©rocycliques (NHCs) et des phosphines en tant que catalyseurs/activateurs organiques.Les prĂ©curseurs de NHCs Ă©tudiĂ©s dans un premier temps, c'est-Ă -dire les hydrogĂ©nocarbonates d azolium, peuvent ĂȘtre synthĂ©tisĂ©s en une seule Ă©tape, Ă  l inverse des NHCs dont la synthĂšse et l isolation sont souvent compliquĂ©es. Nous avons dĂ©montrĂ© que ces espĂšces sont stables Ă  l air et sont Ă  l Ă©quilibre en solution avec leurs homologues carboxylates d azolium (adduits NHC-CO2). Leur utilisation permet donc de faciliter la manipulation des NHCs tout en conservant une activitĂ© catalytique satisfaisante tant en synthĂšse molĂ©culaire qu en chimie des polymĂšres.Des paires de Lewis silane ou borane/NHC ont ensuite Ă©tĂ© employĂ©es afin d augmenter le potentiel des NHCs pour des rĂ©actions modĂšles de chimie (macro)molĂ©culaire par un effet de double assistance (acide/base de Lewis).Enfin, une phosphine commerciale a Ă©tĂ© utilisĂ©e pour catalyser la polymĂ©risation par transfert de groupe des (mĂ©th)acrylates d alkyle de façon vivante/contrĂŽlĂ©e .In this thesis work, some points are adressed in order to broaden the scope of the application of N-heterocyclic carbenes (NHCs) as organic catalysts/activators.The novel NHC precursors studied first, i.e. azolium hydrogen carbonates, are synthesized in a one-step undemanding process, in contrast to NHCs whose synthesis and isolation is often a tedious procedure. We then showed that these species are air-stable and are at the equilibrium, in solution, with their azolium-2-carboxylates homologues (NHC-CO2 adducts). The use of such precatalysts thus allows facilitating the manipulation of NHCs, while maintaining an efficient catalytic activity in molecular chemistry as well as in polymer synthesis.We then proposed to use NHCs in conjunction with organic Lewis acids (silanes or boranes) as a possible means to induce a cooperative dual activation mechanism (Lewis acid/base) in order to increase the potential of NHCs for model (macro)molecular reactions.Finally, a commercial phosphine was used to trigger the group transfer polymerization of alkyl (meth)acrylates in a controlled/living fashion.BORDEAUX1-Bib.electronique (335229901) / SudocSudocFranceF
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