5,109 research outputs found

    Video distribution system cost model

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    A cost model that can be used to systematically identify the costs of procuring and operating satellite linked communications systems is described. The user defines a network configuration by specifying the location of each participating site, the interconnection requirements, and the transmission paths available for the uplink (studio to satellite), downlink (satellite to audience), and voice talkback (between audience and studio) segments of the network. The model uses this information to calculate the least expensive signal distribution path for each participating site. Cost estimates are broken downy by capital, installation, lease, operations and maintenance. The design of the model permits flexibility in specifying network and cost structure

    Prognosis after intracerebral hemorrhage is uncertain, so why not do everything?

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151871/1/ana25555.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151871/2/ana25555_am.pd

    Preferential antiferromagnetic coupling of vacancies in graphene on SiO_2: Electron spin resonance and scanning tunneling spectroscopy

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    Monolayer graphene grown by chemical vapor deposition and transferred to SiO_2 is used to introduce vacancies by Ar^+ ion bombardment at a kinetic energy of 50 eV. The density of defects visible in scanning tunneling microscopy (STM) is considerably lower than the ion fluence implying that most of the defects are single vacancies. The vacancies are characterized by scanning tunneling spectroscopy (STS) on graphene and HOPG exhibiting a peak close to the Fermi level. The peak persists after air exposure up to 180 min, albeit getting broader. After air exposure for less than 60 min, electron spin resonance (ESR) at 9.6 GHz is performed. For an ion flux of 10/nm^2, we find a signal corresponding to a g-factor of 2.001-2.003 and a spin density of 1-2 spins/nm^2. The ESR signal consists of a mixture of a Gaussian and a Lorentzian of equal weight exhibiting a width down to 0.17 mT, which, however, depends on details of the sample preparation. The g-factor anisotropy is about 0.02%. Temperature dependent measurements reveal antiferromagnetic correlations with a Curie-Weiss temperature of -10 K. Albeit the electrical conductivity of graphene is significantly reduced by ion bombardment, the spin resonance induced change in conductivity is below 10^{-5}.Comment: 10 pages, 5 figures, discussion on STM images in the literature of defects in graphene adde

    Multiple sequence alignment based on set covers

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    We introduce a new heuristic for the multiple alignment of a set of sequences. The heuristic is based on a set cover of the residue alphabet of the sequences, and also on the determination of a significant set of blocks comprising subsequences of the sequences to be aligned. These blocks are obtained with the aid of a new data structure, called a suffix-set tree, which is constructed from the input sequences with the guidance of the residue-alphabet set cover and generalizes the well-known suffix tree of the sequence set. We provide performance results on selected BAliBASE amino-acid sequences and compare them with those yielded by some prominent approaches

    Setting priorities for stroke care and research

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/99062/1/ijs12153.pd

    Apparent rippling with honeycomb symmetry and tunable periodicity observed by scanning tunneling microscopy on suspended graphene

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    Suspended graphene is difficult to image by scanning probe microscopy due to the inherent van-der-Waals and dielectric forces exerted by the tip which are not counteracted by a substrate. Here, we report scanning tunneling microscopy data of suspended monolayer graphene in constant-current mode revealing a surprising honeycomb structure with amplitude of 50−-200 pm and lattice constant of 10-40 nm. The apparent lattice constant is reduced by increasing the tunneling current II, but does not depend systematically on tunneling voltage VV or scan speed vscanv_{\rm scan}. The honeycomb lattice of the rippling is aligned with the atomic structure observed on supported areas, while no atomic corrugation is found on suspended areas down to the resolution of about 3−43-4 pm. We rule out that the honeycomb structure is induced by the feedback loop using a changing vscanv_{\rm scan}, that it is a simple enlargement effect of the atomic resolution as well as models predicting frozen phonons or standing phonon waves induced by the tunneling current. Albeit we currently do not have a convincing explanation for the observed effect, we expect that our intriguing results will inspire further research related to suspended graphene.Comment: 10 pages, 7 figures, modified, more detailed discussion on errors in vdW parameter

    Qualität des Weidefutters in der ökologischen Milchviehhaltung

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    Grazing of dairy cows is mandatory in organic farming. However, as in conventional farming there is a tendency to increase milk yield per cows by employing other feeding strategies than grazing. On-farm research was initiated on organic dairy farms in Lower Saxony to investigate the current practice of grassland utilization and dairy husbandry and to explore the potential of grazing for milk production. The results show that with an increased focus on grazing of dairy cows there is considerable room for more milk being produced from grazed grass. An in-depth analysis of the spatio-temporal pattern of the quality of the herbage on offer revealed steadily high net energy and protein concentrations almost irrespective of the sward botanical composition and the season of sampling. Research is needed to improve grazing management strategies in organic farming to make better use of the high potential of grazed grasslands and thereby increase the sustainability of milk production

    TICO: a tool for postprocessing the predictions of prokaryotic translation initiation sites

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    Exact localization of the translation initiation sites (TIS) in prokaryotic genomes is difficult to achieve using conventional gene finders. We recently introduced the program TICO for postprocessing TIS predictions based on a completely unsupervised learning algorithm. The program can be utilized through our web interface at and it is also freely available as a commandline version for Linux and Windows. The latest version of our program provides a tool for visualization of the resulting TIS model. Although the underlying method is not based on any specific assumptions about characteristic sequence features of prokaryotic TIS the prediction rates of our tool are competitive on experimentally verified test data
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