563 research outputs found

    Weinberg like sum rules revisited

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    The generalized Weinberg sum rules containing the difference of isovector vector and axial-vector spectral functions saturated by both finite and infinite number of narrow resonances are considered. We summarize the status of these sum rules and analyze their overall agreement with phenomenological Lagrangians, low-energy relations, parity doubling, hadron string models, and experimental data.Comment: 31 pages, noticed misprints are corrected, references are added, and other minor corrections are mad

    Mapping Patent Classifications: Portfolio and Statistical Analysis, and the Comparison of Strengths and Weaknesses

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    The Cooperative Patent Classifications (CPC) jointly developed by the European and US Patent Offices provide a new basis for mapping and portfolio analysis. This update provides an occasion for rethinking the parameter choices. The new maps are significantly different from previous ones, although this may not always be obvious on visual inspection. Since these maps are statistical constructs based on index terms, their quality--as different from utility--can only be controlled discursively. We provide nested maps online and a routine for portfolio overlays and further statistical analysis. We add a new tool for "difference maps" which is illustrated by comparing the portfolios of patents granted to Novartis and MSD in 2016.Comment: Scientometrics 112(3) (2017) 1573-1591; http://link.springer.com/article/10.1007/s11192-017-2449-

    Relics as probes of galaxy cluster mergers

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    Galaxy clusters grow by mergers with other clusters and galaxy groups. These mergers create shocks within the intracluster medium (ICM). It is proposed that within the shocks particles can be accelerated to extreme energies. In the presence of a magnetic field these particles should then form large regions emitting synchrotron radiation, creating so-called radio relics. An example of a cluster with relics is CIZA J2242.8+5301. Here we present hydrodynamical simulations of idealized binary cluster collisions with the aim of constraining the merger scenario for this cluster. We conclude that by using the location, size and width of double radio relics we can set constraints on the mass ratios, impact parameters, timescales, and viewing geometries of binary cluster merger events.Comment: Accepted for publication in special issue of Journal of Astrophysics and Astronomy: conference proceedings of "Diffuse Relativistic Plasmas" conference, Bangalore, 1-4 March 2011, 4 pages, 2 figure

    Myelofibrosis: molecular and cell biological aspects

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    A subset of myeloproliferative disorders (MPN) and myelodyplastic syndromes (MDS) evolves to fibrosis of the bone marrow associated with haematopoietic insufficiency. We have been interested in chemokines involved in fibrogenesis within the bone marrow. Besides TGFβ we could identify a number of additional mediators including osteoprotegerin and bone morphogenic proteins. In MPN JAK2 or MPL mutation are not linked to the propensity for bone marrow fibrosis. The hypothesis that an increased intramedullary decay of megakaryocytes undergoing appotosis takes place within the marrow, thus liberating fibrogenic cytokines, could not be confirmed. On the contrary, megakaryocytes in primary fibrosis revealed low expression of proapoptotic genes such as BNIP3. Interestingly, BNIP 3 expression was down regulated in megakaryocytic cell lines kept in hypoxic conditions. Furthermore, expression arrays revealed hypoxia inducible genes to be up-regulated in primary myelofibrosis. Fibrotic MPN are characterized by aberrant proplatelet formation which represent cytoplasmic pseudopodia and normally extend into the sinus. In fibrotic MPN orientation of proplatelet growth appears to be disturbed, which could lead to an aberrant deposition of platelets in the marrow with consecutive liberation of fibrogenic cytokines

    Industry in Motion: Using Smart Phones to Explore the Spatial Network of the Garment Industry in New York City

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    Industrial agglomerations have long been thought to offer economic and social benefits to firms and people that are only captured by location within their specified geographies. Using the case study of New York City’s garment industry along with data acquired from cell phones and social media, this study set out to understand the discrete activities underpinning the economic dynamics of an industrial agglomeration. Over a two week period, data was collected by employing the geo-locative capabilities of Foursquare, a social media application, to record every movement of fashion workers employed at fashion design firms located both inside and outside the geographical boundaries of New York City’s Garment District. This unique method of studying worker activity exposed the day-to-day dynamics of an industrial district with a precision thus far undocumented in literature. Our work suggests that having access to the cluster provides almost the same agglomeration economies as residing within its borders.Rockefeller Foundatio

    Co-occurrence of diabetes and hopelessness predicts adverse prognosis following percutaneous coronary intervention

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    We examined the impact of co-occurring diabetes and hopelessness on 3-year prognosis in percutaneous coronary intervention patients. Consecutive patients (n = 534) treated with the paclitaxel-eluting stent completed a set of questionnaires at baseline and were followed up for 3-year adverse clinical events. The incidence of 3-year death/non-fatal myocardial infarction was 3.5% in patients with no risk factors (neither hopelessness nor diabetes), 8.2% in patients with diabetes, 11.2% in patients with high hopelessness, and 15.9% in patients with both factors (p = 0.001). Patients with hopelessness (HR: 3.28; 95% CI: 1.49-7.23) and co-occurring diabetes and hopelessness (HR: 4.89; 95% CI: 1.86-12.85) were at increased risk of 3-year adverse clinical events compared to patients with no risk factors, whereas patients with diabetes were at a clinically relevant but not statistically significant risk (HR: 2.40; 95% CI: 0.82-7.01). These results remained, adjusting for baseline characteristics an

    Clusters of galaxies : observational properties of the diffuse radio emission

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    Clusters of galaxies, as the largest virialized systems in the Universe, are ideal laboratories to study the formation and evolution of cosmic structures...(abridged)... Most of the detailed knowledge of galaxy clusters has been obtained in recent years from the study of ICM through X-ray Astronomy. At the same time, radio observations have proved that the ICM is mixed with non-thermal components, i.e. highly relativistic particles and large-scale magnetic fields, detected through their synchrotron emission. The knowledge of the properties of these non-thermal ICM components has increased significantly, owing to sensitive radio images and to the development of theoretical models. Diffuse synchrotron radio emission in the central and peripheral cluster regions has been found in many clusters. Moreover large-scale magnetic fields appear to be present in all galaxy clusters, as derived from Rotation Measure (RM) studies. Non-thermal components are linked to the cluster X-ray properties, and to the cluster evolutionary stage, and are crucial for a comprehensive physical description of the intracluster medium. They play an important role in the cluster formation and evolution. We review here the observational properties of diffuse non-thermal sources detected in galaxy clusters: halos, relics and mini-halos. We discuss their classification and properties. We report published results up to date and obtain and discuss statistical properties. We present the properties of large-scale magnetic fields in clusters and in even larger structures: filaments connecting galaxy clusters. We summarize the current models of the origin of these cluster components, and outline the improvements that are expected in this area from future developments thanks to the new generation of radio telescopes.Comment: Accepted for the publication in The Astronomy and Astrophysics Review. 58 pages, 26 figure

    A Microscope Automated Fluidic System to Study Bacterial Processes in Real Time

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    Most time lapse microscopy experiments studying bacterial processes ie growth, progression through the cell cycle and motility have been performed on thin nutrient agar pads. An important limitation of this approach is that dynamic perturbations of the experimental conditions cannot be easily performed. In eukaryotic cell biology, fluidic approaches have been largely used to study the impact of rapid environmental perturbations on live cells and in real time. However, all these approaches are not easily applicable to bacterial cells because the substrata are in all cases specific and also because microfluidics nanotechnology requires a complex lithography for the study of micrometer sized bacterial cells. In fact, in many cases agar is the experimental solid substratum on which bacteria can move or even grow. For these reasons, we designed a novel hybrid micro fluidic device that combines a thin agar pad and a custom flow chamber. By studying several examples, we show that this system allows real time analysis of a broad array of biological processes such as growth, development and motility. Thus, the flow chamber system will be an essential tool to study any process that take place on an agar surface at the single cell level

    RNAi-mediated COPS3 gene silencing inhibits metastasis of osteogenic sarcoma cells

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    Metastatic disease is the primary cause of mortality among patients with osteogenic sarcoma (OGS). In this study, we aimed to identify the relationship of COPS3 gene expression to metastasis. Immunohistochemical staining for COPS3 was performed on 65 OGS samples (37 without and 28 with metastatic disease); 18.9% (7/37) of specimens from patients with no metastasis and 57.1% (16/28) of specimens from patients with metastasis showed intense staining of COPS3. Comparison of COPS3 expression between a poorly metastatic osteosarcoma cell line (SAOS-2) and highly metastatic osteosarcoma cell line (HOS) showed stronger expression of COPS3 in HOS cells. Inhibiting COPS3 function by siRNA resulted in reduced proliferation and migration of HOS cells. Inhibition of COPS3 gene downregulated expression of the MAPK signaling pathway, which has an important role in metastasis of OGS. Our results suggested that overexpression of the COPS3 gene might have important roles in metastasis of osteosarcoma cells
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