429 research outputs found

    Nucleosome rotational setting is associated with transcriptional regulation in promoters of tissue-specific human genes

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    Human genes contain a 10 bp repeat of RR dinucleotides focused around the first nucleosome position suggesting a role in transcriptional control

    Do Telecommunications and Air/Sea Transport Problems Limit Madagascar's Exports?

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    This study had its origins in the notion that Madagascar's ability to expand and diversity its exports was significantly hampered by three conditions: *high sea freight rates as a result of oligopolistic practices by a shipping conference; *Air Madagascar's monopoly on air traffic rights; and *an obsolete and often non-functional national telecommunications system. To what extent is the perception correct? For two weeks we asked this question in interviews of manufacturers, shipping agents, airline executives, ship operators, port authorities and government officials. Two weeks are clearly insufficient for a detailed study of both the transportation sector and the telecommunications system. The period may be adequate, however, for the purpose of determining the basic validity of the perceptions which prompted this study. The following, somewhat general statements reflect our conclusions. The rest of the report provides supporting detail.Center for Research on Economic Development, University of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/100993/1/ECON434.pd

    Identification of Birds through DNA Barcodes

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    Short DNA sequences from a standardized region of the genome provide a DNA barcode for identifying species. Compiling a public library of DNA barcodes linked to named specimens could provide a new master key for identifying species, one whose power will rise with increased taxon coverage and with faster, cheaper sequencing. Recent work suggests that sequence diversity in a 648-bp region of the mitochondrial gene, cytochrome c oxidase I (COI), might serve as a DNA barcode for the identification of animal species. This study tested the effectiveness of a COI barcode in discriminating bird species, one of the largest and best-studied vertebrate groups. We determined COI barcodes for 260 species of North American birds and found that distinguishing species was generally straightforward. All species had a different COI barcode(s), and the differences between closely related species were, on average, 18 times higher than the differences within species. Our results identified four probable new species of North American birds, suggesting that a global survey will lead to the recognition of many additional bird species. The finding of large COI sequence differences between, as compared to small differences within, species confirms the effectiveness of COI barcodes for the identification of bird species. This result plus those from other groups of animals imply that a standard screening threshold of sequence difference (10× average intraspecific difference) could speed the discovery of new animal species. The growing evidence for the effectiveness of DNA barcodes as a basis for species identification supports an international exercise that has recently begun to assemble a comprehensive library of COI sequences linked to named specimens

    Human Interaction: A key to managing disruptive behavior in dementia.

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    The results are part of a larger multi-center, mixed-methods study investigating the effect of environmental design in managing disruptive behavior in dementia. The presentation focuses on data from fifteen (15) discussion groups conducted with families (N = 45) and staff (N= 59) from eight (8) dementia units. Participants were asked to identify the primary obstacles and facilitators for managing behaviors in long-term care facilities. Results stress the importance of human interaction and institutional flexibility. These will be discussed in the context of communication environments and supported by observational data obtained in five (5) of the units

    Surrogate: A Body-Dexterous Mobile Manipulation Robot with a Tracked Base

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    Robotics platforms in accordance with various embodiments of the invention can be utilized to implement highly dexterous robots capable of whole body motion. Robotics platforms in accordance with one embodiment of the invention include: a memory containing a whole body motion application; a spine, where the spine has seven degrees of freedom and comprises a spine actuator and three spine elbow joints that each include two spine joint actuators; at least one limb, where the at least one limb comprises a limb actuator and three limb elbow joints that each include two limb joint actuators; a tracked base; a connecting structure that connects the at least one limb to the spine; a second connecting structure that connects the spine to the tracked base; wherein the processor is configured by the whole body motion application to move the at least one limb and the spine to perform whole body motion

    Early Components of the Complement Classical Activation Pathway in Human Systemic Autoimmune Diseases

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    The complement system consists of effector proteins, regulators, and receptors that participate in host defense against pathogens. Activation of the complement system, via the classical pathway (CP), has long been recognized in immune complex-mediated tissue injury, most notably systemic lupus erythematosus (SLE). Paradoxically, a complete deficiency of an early component of the CP, as evidenced by homozygous genetic deficiencies reported in human, are strongly associated with the risk of developing SLE or a lupus-like disease. Similarly, isotype deficiency attributable to a gene copy number variation, and/or the presence of autoantibodies directed against a CP component or a regulatory protein that result in an acquired deficiency are relatively common in SLE patients. Applying accurate assay methodologies with rigorous data validations, low gene copy numbers of total C4, heterozygous and homozygous deficiencies of C4A have been shown as medium to large effect size risk factors, while high copy numbers of total C4 or C4A as prevalent protective factors, of European and East-Asian SLE. Here, we summarize the current knowledge related to genetic deficiency and insufficiency, and acquired protein alterations for C1q, C1r, C1s, C4A/C4B, and C2 in disease pathogenesis and prognosis of SLE, and, briefly, for other systemic autoimmune diseases. As the complement system is increasingly found to be associated with autoimmune diseases, it has become an attractive therapeutic target. We highlight the recent developments and offer a balanced perspective concerning future investigations and therapeutic applications with a focus on early components of the CP in human systemic autoimmune diseases

    Mechanism of imidazolium ionic liquids toxicity in Saccharomyces cerevisiae and rational engineering of a tolerant, xylose-fermenting strain

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    Additional file 3. Fermentation profiles of Y133 and Y133-IIL in the presence of 1 % [BMIM]Cl at pH 6.5 and pH 5.0, and either aerobic or anaerobic conditions (n = 3, Mean ± S.E, except n = 2 for Y133 pH 6.5 anaerobic 72 h)

    The SXS Collaboration catalog of binary black hole simulations

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    Accurate models of gravitational waves from merging black holes are necessary for detectors to observe as many events as possible while extracting the maximum science. Near the time of merger, the gravitational waves from merging black holes can be computed only using numerical relativity. In this paper, we present a major update of the Simulating eXtreme Spacetimes (SXS) Collaboration catalog of numerical simulations for merging black holes. The catalog contains 2018 distinct configurations (a factor of 11 increase compared to the 2013 SXS catalog), including 1426 spin-precessing configurations, with mass ratios between 1 and 10, and spin magnitudes up to 0.998. The median length of a waveform in the catalog is 39 cycles of the dominant =m=2\ell=m=2 gravitational-wave mode, with the shortest waveform containing 7.0 cycles and the longest 351.3 cycles. We discuss improvements such as correcting for moving centers of mass and extended coverage of the parameter space. We also present a thorough analysis of numerical errors, finding typical truncation errors corresponding to a waveform mismatch of 104\sim 10^{-4}. The simulations provide remnant masses and spins with uncertainties of 0.03% and 0.1% (90th90^{\text{th}} percentile), about an order of magnitude better than analytical models for remnant properties. The full catalog is publicly available at https://www.black-holes.org/waveforms .Comment: 33+18 pages, 13 figures, 4 tables, 2,018 binaries. Catalog metadata in ancillary JSON file. v2: Matches version accepted by CQG. Catalog available at https://www.black-holes.org/waveform
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