99 research outputs found

    A broadband noise prediction scheme for low-noise centrifugal blowers

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    In this paper we outline a semi-empirical procedure for predicting the broadband sound power spectrum radiated by any member of a family of geometrically similar, centrifugal blowers. The prediction scheme is based on the use of a normalized sound power spectrum that is obtained by measuring the sound power radiated by one member of the blower family. In the present instance, a low noise blower design has been identified by conducting a large scale parametric study of blower noise as a function of geometrical design parameters and operating point; the resulting optimum design served to define the geometrical parameters of the blower family considered here. The prediction procedure allows calculation of either 1/3-octave band spectral levels or overall A-weighted levels. In addition it is possible to calculate noise surfaces, i.e., plots of A-weighted sound power level versus design parameters and operating condition; in this way it is easy to identify optimally quiet blower designs that satisfy specified pumping requirements. It has been found, for example, that large diameter impellers of relatively small width operating at low speeds tend to result in the lowest noise level at a given pumping requirement

    Experimental design of a low noise centrifugal fan

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    The effect of various design parameters on broadband noise generation by centrifugal fans has been studied. The parameters varied included: blade type, radial and axial inlet clearance, scroll development angle, scroll development length and cutoff clearance. Scaling laws for pressure, flow and noise were applied to allow the A-weighted sound power levels of different fans to be compared at the same operating points. That approach has allowed an optimum low noise fan design to be identified. To extend the usefulness of that design, a semi-empirical procedure for predicting the broadband sound power spectrum of any member of a family of geometrically similar centrifugal fans has also been developed. The prediction procedure allows the calculation of 1/3-octave band sound power levels based on a measurement of the sound power radiated by a single member of the fan family. By the use of the prediction procedure, it is straightforward to identify optimally quiet fans that satisfy a range of pumping requirements

    Language specific preferences in anaphor resolution: Exposure or gricean maxims?

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    International audienceIn this paper we will present evidence for language specific preferences in anaphor resolution from two series of experiments in English, German, and French. For within sentence anaphor resolution with "before" subclauses, we will show that English and German follow the generally assumed preference for the first mentioned NP or subject of the sentence, whereas French shows a clear preference for the object of the matrix clause. We will argue that our data can most easily be explained by a usage-based account, linking comprehension preferences to production preferences

    Sexual Dimorphism of Staminate- and Pistillate-Phase Flowers of Saponaria officinalis (Bouncing Bet) Affects Pollinator Behavior and Seed Set

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    The sequential separation of male and female function in flowers of dichogamous species allows for the evolution of differing morphologies that maximize fitness through seed siring and seed set. We examined staminate- and pistillate-phase flowers of protandrous Saponaria officinalis for dimorphism in floral traits and their effects on pollinator attraction and seed set. Pistillate-phase flowers have larger petals, greater mass, and are pinker in color, but due to a shape change, pistillate-phase flowers have smaller corolla diameters than staminate-phase flowers. There was no difference in nectar volume or sugar content one day after anthesis, and minimal evidence for UV nectar guide patterns in staminate- and pistillate-phase flowers. When presented with choice arrays, pollinators discriminated against pistillate-phase flowers based on their pink color. Finally, in an experimental garden, in 2012 there was a negative correlation between seed set of an open-pollinated, emasculated flower and pinkness (as measured by reflectance spectrometry) of a pistillate-phase flower on the same plant in plots covered with shade cloth. In 2013, clones of genotypes chosen from the 2012 plants that produced pinker flowers had lower seed set than those from genotypes with paler flowers. Lower seed set of pink genotypes was found in open-pollinated and hand-pollinated flowers, indicating the lower seed set might be due to other differences between pink and pale genotypes in addition to pollinator discrimination against pink flowers. In conclusion, staminate- and pistillate-phase flowers of S. officinalis are dimorphic in shape and color. Pollinators discriminate among flowers based on these differences, and individuals whose pistillate-phase flowers are most different in color from their staminate-phase flowers make fewer seeds. We suggest morphological studies of the two sex phases in dichogamous, hermaphroditic species can contribute to understanding the evolution of sexual dimorphism in plants without the confounding effects of genetic differences between separate male and female individuals

    Myofiber integrity depends on desmin network targeting to Z-disks and costameres via distinct plectin isoforms

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    Dysfunction of plectin, a 500-kD cytolinker protein, leads to skin blistering and muscular dystrophy. Using conditional gene targeting in mice, we show that plectin deficiency results in progressive degenerative alterations in striated muscle, including aggregation and partial loss of intermediate filament (IF) networks, detachment of the contractile apparatus from the sarcolemma, profound changes in myofiber costameric cytoarchitecture, and decreased mitochondrial number and function. Analysis of newly generated plectin isoform–specific knockout mouse models revealed that IF aggregates accumulate in distinct cytoplasmic compartments, depending on which isoform is missing. Our data show that two major plectin isoforms expressed in muscle, plectin 1d and 1f, integrate fibers by specifically targeting and linking desmin IFs to Z-disks and costameres, whereas plectin 1b establishes a linkage to mitochondria. Furthermore, disruption of Z-disk and costamere linkages leads to the pathological condition of epidermolysis bullosa with muscular dystrophy. Our findings establish plectin as the major organizer of desmin IFs in myofibers and provide new insights into plectin- and desmin-related muscular dystrophies

    GraphMineSuite: Enabling High-Performance and Programmable Graph Mining Algorithms with Set Algebra

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    We propose GraphMineSuite (GMS): the first benchmarking suite for graph mining that facilitates evaluating and constructing high-performance graph mining algorithms. First, GMS comes with a benchmark specification based on extensive literature review, prescribing representative problems, algorithms, and datasets. Second, GMS offers a carefully designed software platform for seamless testing of different fine-grained elements of graph mining algorithms, such as graph representations or algorithm subroutines. The platform includes parallel implementations of more than 40 considered baselines, and it facilitates developing complex and fast mining algorithms. High modularity is possible by harnessing set algebra operations such as set intersection and difference, which enables breaking complex graph mining algorithms into simple building blocks that can be separately experimented with. GMS is supported with a broad concurrency analysis for portability in performance insights, and a novel performance metric to assess the throughput of graph mining algorithms, enabling more insightful evaluation. As use cases, we harness GMS to rapidly redesign and accelerate state-of-the-art baselines of core graph mining problems: degeneracy reordering (by up to >2x), maximal clique listing (by up to >9x), k-clique listing (by 1.1x), and subgraph isomorphism (by up to 2.5x), also obtaining better theoretical performance bounds

    Endogenous IL-1 receptor antagonist restricts healthy and malignant myeloproliferation.

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    Here we explored the role of interleukin-1β (IL-1β) repressor cytokine, IL-1 receptor antagonist (IL-1rn), in both healthy and abnormal hematopoiesis. Low IL-1RN is frequent in acute myeloid leukemia (AML) patients and represents a prognostic marker of reduced survival. Treatments with IL-1RN and the IL-1β monoclonal antibody canakinumab reduce the expansion of leukemic cells, including CD34+ progenitors, in AML xenografts. In vivo deletion of IL-1rn induces hematopoietic stem cell (HSC) differentiation into the myeloid lineage and hampers B cell development via transcriptional activation of myeloid differentiation pathways dependent on NFκB. Low IL-1rn is present in an experimental model of pre-leukemic myelopoiesis, and IL-1rn deletion promotes myeloproliferation, which relies on the bone marrow hematopoietic and stromal compartments. Conversely, IL-1rn protects against pre-leukemic myelopoiesis. Our data reveal that HSC differentiation is controlled by balanced IL-1β/IL-1rn levels under steady-state, and that loss of repression of IL-1β signaling may underlie pre-leukemic lesion and AML progression.We thank K. Tasken, J. Saarela and the NCMM at the University of Oslo (UiO), S. Kanse (UiO) and B. Smedsrød (UiT), for access to facilities. We acknowledge Center for Medical Genetics and Molecular Medicine, Haukeland University Hospital (Bergen, Norway) and R. Hovland for karyotyping, FISH, translocation and DNA analyses of AML and MDS patients included in this study, and Department of Pathology, Oslo University Hospital (Oslo, Norway) and S. Spetalen for deep sequencing. L.M. Gonzalez, L.T. Eliassen, X. Zhang, M. Ristic and other members of L. Arranz group, O.P. Rekvig, R. Doohan, L.D. Håland, M.I. Olsen, A. Urbanucci, J. Landskron, K.B. Larsen, R.A. Lyså and UiT Advanced Microscopy Core Facility, UiO and UiT Comparative Medicine Units, for assistance. P. Garcia and S. Mendez-Ferrer for providing NRASG12D and Nes-gfp mice, respectively. P. Garcia and L. Kurian for careful reading of the manuscript. E. Tenstad (Science Shaped) for artwork in schematics. We would also like to thank the AML and MDS patients, and healthy volunteers, who donated biological samples. Our work is supported by a joint meeting grant of the Northern Norway Regional Health Authority, the University Hospital of Northern Norway (UNN) and UiT (Strategisk-HN06-14), Young Research Talent grants from the Research Council of Norway, (Stem Cell Program, 247596; FRIPRO Program, 250901), and grants from the Norwegian Cancer Society (6765150), the Northern Norway Regional Health Authority (HNF1338-17), and the Aakre-Stiftelsen Foundation (2016/9050) to L.A. Vav-Cre NRASG12D experiments were supported by NIH grant R01CA152108 to J.Z.S

    Endogenous IL-1 receptor antagonist restricts healthy and malignant myeloproliferation

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    Here we explored the role of interleukin-1β (IL-1β) repressor cytokine, IL-1 receptor antagonist (IL-1rn), in both healthy and abnormal hematopoiesis. Low IL-1RN is frequent in acute myeloid leukemia (AML) patients and represents a prognostic marker of reduced survival. Treatments with IL-1RN and the IL-1β monoclonal antibody canakinumab reduce the expansion of leukemic cells, including CD34+ progenitors, in AML xenografts. In vivo deletion of IL-1rn induces hematopoietic stem cell (HSC) differentiation into the myeloid lineage and hampers B cell development via transcriptional activation of myeloid differentiation pathways dependent on NFκB. Low IL-1rn is present in an experimental model of pre-leukemic myelopoiesis, and IL-1rn deletion promotes myeloproliferation, which relies on the bone marrow hematopoietic and stromal compartments. Conversely, IL-1rn protects against pre-leukemic myelopoiesis. Our data reveal that HSC differentiation is controlled by balanced IL-1β/IL-1rn levels under steady-state, and that loss of repression of IL-1β signaling may underlie pre-leukemic lesion and AML progression

    Histology and symplasmic tracer distribution during development of barley androgenic embryos

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    The present study concerns three aspects of barley androgenesis: (1) the morphology and histology of the embryos during their development, (2) the time course of fluorescent symplasmic tracers’ distribution, and (3) the correlation between symplasmic communication and cell differentiation. The results indicate that barley embryos, which are developing via an androgenic pathway, resemble their zygotic counterparts with respect to their developmental stages, morphology and histology. Analysis of the distribution of the symplasmic tracers, HPTS, and uncaged fluorescein indicates the symplasmic isolation of (1) the protodermis from the underlying cells of the late globular stage onwards, and (2) the embryonic organs at the mature stage of development
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