258 research outputs found

    Workshops without Walls: Broadening Access to Science around the World

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    The National Aeronautics and Space Administration (NASA) Astrobiology Institute (NAI) conducted two “Workshops Without Walls” during 2010 that enabled global scientific exchange—with no travel required. The second of these was on the topic “Molecular Paleontology and Resurrection: Rewinding the Tape of Life.” Scientists from diverse disciplines and locations around the world were joined through an integrated suite of collaborative technologies to exchange information on the latest developments in this area of origin of life research. Through social media outlets and popular science blogs, participation in the workshop was broadened to include educators, science writers, and members of the general public. In total, over 560 people from 31 US states and 30 other nations were registered. Among the scientific disciplines represented were geochemistry, biochemistry, molecular biology and evolution, and microbial ecology. We present this workshop as a case study in how interdisciplinary collaborative research may be fostered, with substantial public engagement, without sustaining the deleterious environmental and economic impacts of travel

    Fgf15 Neurons of the Dorsomedial Hypothalamus Control Glucagon Secretion and Hepatic Gluconeogenesis.

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    The counterregulatory response to hypoglycemia is an essential survival function. It is controlled by an integrated network of glucose-responsive neurons, which trigger endogenous glucose production to restore normoglycemia. The complexity of this glucoregulatory network is, however, only partly characterized. In a genetic screen of a panel of recombinant inbred mice we previously identified Fgf15, expressed in neurons of the dorsomedial hypothalamus (DMH), as a negative regulator of glucagon secretion. Here, we report on the generation of Fgf15 <sup>CretdTomato</sup> mice and their use to further characterize these neurons. We show that they were glutamatergic and comprised glucose-inhibited and glucose-excited neurons. When activated by chemogenetics, Fgf15 neurons prevented the increase in vagal nerve firing and the secretion of glucagon normally triggered by insulin-induced hypoglycemia. On the other hand, they increased the activity of the sympathetic nerve in the basal state and prevented its silencing by glucose overload. Higher sympathetic tone increased hepatic Creb1 phosphorylation, Pck1 mRNA expression, and hepatic glucose production leading to glucose intolerance. Thus, Fgf15 neurons of the DMH participate in the counterregulatory response to hypoglycemia by a direct adrenergic stimulation of hepatic glucose production while suppressing vagally induced glucagon secretion. This study provides new insights into the complex neuronal network that prevents the development of hypoglycemia

    Wikiplantbase #Toscana, breaking the dormancy of floristic data

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    The online platform "Wikiplantbase #Toscana" provides a framework where the full set of georeferenced floristic records of Tuscany (central Italy) can be entered, stored, updated and freely accessed through the Internet. As of 5 January 2015, the database stores 67,360 floristic records, referable to 3578 accepted specific and subspecific taxa. Most records are based on published data (80.6% of the total), then by published herbarium specimens (15.1%) and on unpublished field data (3.8%); unpublished herbarium records account only for 0.5% of the stored data. At present, the most represented species is the fern Pteridium aquilinum (L.) Kuhn subsp. aquilinum (Dennstaedtiaceae) with 234 records for 219 localities, but 625 species are still represented only by one record for a single locality. Data acquisition is far from complete, but in slightly more than one year a massive amount of data was accumulated, and can be maintained up-to-date with relatively little effort. This could power several researches such as, for example, (1) taxonomic researches especially on species and genera in Tuscany and Italy; (2) studies on the distribution of diversity across administrative or ecological boundaries; (3) evaluation of conservation status of endangered taxa; and (4) static and dynamic range modelling and evolution niche studies

    Very large scale high performance computing and instrument management for high availability systems through the use of virtualization at the Square Kilometre Array (SKA) telescope

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    The Square Kilometer Array (SKA) Telescope, is an ongoing project set to start its building phase in 2018 and be ready for first light in 2020. The first part of the project, the SKA1 will be comprised of 130.000 low frequency antennas (50 MHz to 350 MHz) and 200 mid frequency antennas (350 MHz to 15.5 GHz). The SKA1 will produce a raw data rate of ~10 Tb/s, require a computing power of 100 Pflop/s and an archiving capacity of hundreds of PB/year. The next phase of the project, the SKA2, is going to increase the number of both low and mid antennas by a factor of 10 and increase the computing requirements accordingly. The key requirements for the project are a very demanding availability of 99.9%, computing scalability and result reproducibility. We propose an approach to enforce these requirements - with an optimal use of resources - by using highly distributed computing and virtualization technologies.publishe

    Is risk of central nervous system (CNS) relapse related to adjuvant taxane treatment in node-positive breast cancer? Results of the CNS substudy in the intergroup phase III BIG 02-98 trial

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    Background: Breast cancer central nervous system (CNS) metastases are an increasingly important problem because of high CNS relapse rates in patients treated with trastuzumab and/or taxanes. Patients and methods: We evaluated data from 2887 node-positive breast cancer patients randomised in the BIG 02-98 trial comparing anthracycline-based adjuvant chemotherapy (control arms) to anthracycline-docetaxel-based sequential or concurrent chemotherapy (experimental arms). After a median follow-up of 5 years, 403 patients had died and detailed information on CNS relapse was collected for these patients. Results: CNS relapse occurred in 4.0% of control patients and 3.7% of docetaxel-treated patients. CNS relapse occurred in 27% of deceased patients in both treatment groups. CNS relapse was usually accompanied by neurologic symptoms (90%), and 25% of patients with CNS relapse died without evidence of extra-CNS relapse. Only 20% of patients survived 1 year from the diagnosis of CNS relapse. Prognosis of CNS relapse was worse for patients with meningeal carcinomatosis when compared with brain metastases. Unexpected findings included a higher rate of positive cerebrospinal fluid cytology (8% versus 3%) and more frequent use of magnetic resonance imaging for diagnosis (47% versus 30%) in the docetaxel-treated patients. Conclusion: There is no evidence that adjuvant docetaxel treatment is associated with an increased frequency of CNS relaps

    Sempervirine inhibits RNA polymerase I transcription independently from p53 in tumor cells

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    In the search of small molecules that can target MDM2/p53 pathway in testicular germ cell tumors (TGCTs), we identified sempervirine (2,3,4,13-tetrahydro-1H-benz[g]indolo[2,3-a]quinolizin-6-ium), an alkaloid of Gelsemium sempervirens, that has been previously proposed as an inhibitor of MDM2 that targets p53-wildtype (wt) tumor cells. We found that sempervirine not only affects cell growth of p53-wt cancer cells, but it is also active in p53-mutated and p53-null cells by triggering p53-dependent and independent pathways without affecting non-transformed cells. To understand which mechanism/s could be activated both in p53-wt and -null cells, we found that sempervirine induced nucleolar remodeling and nucleolar stress by reducing protein stability of RPA194, the catalytic subunit of RNA polymerase I, that led to rRNA synthesis inhibition and to MDM2 block. As shown for other cancer cell models, MDM2 inhibition by nucleolar stress downregulated E2F1 protein levels both in p53-wt and p53-null TGCT cells with the concomitant upregulation of unphosphorylated pRb. Finally, we show that sempervirine is able to enter the nucleus and accumulates within the nucleolus where it binds rRNA without causing DNA damage. Our results identify semperivirine as a novel rRNA synthesis inhibitor and indicate this drug as a non-genotoxic anticancer small molecule

    TM Services: an architecture for monitoring and controlling the Square Kilometre Array (SKA) Telescope Manager (TM)

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    The SKA project is an international effort (10 member and 10 associated countries with the involvement of 100 companies and research institutions) to build the world's largest radio telescope. The SKA Telescope Manager (TM) is the core package of the SKA Telescope aimed at scheduling observations, controlling their execution, monitoring the telescope and so on. To do that, TM directly interfaces with the Local Monitoring and Control systems (LMCs) of the other SKA Elements (for example, Dishes, Correlator and so on), exchanging commands and data with them by using the TANGO controls framework (see [1]). TM in turn needs to be monitored and controlled, in order its continuous and proper operation is ensured and this higher responsibility has been assigned to the TM SER package

    SN 2002cv: A Heavily Obscured Type Ia Supernova

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    We present VRIJHK photometry, and optical and near-infrared spectroscopy, of the heavily extinguished Type Ia supernova (SN) 2002cv, located in NGC 3190, which is also the parent galaxy of the Type Ia SN 2002bo. SN 2002cv, not visible in the blue, has a total visual extinction of 8.74 +- 0.21 mag. In spite of this we were able to obtain the light curves between -10 and +207 days from the maximum in the I band, and also to follow the spectral evolution, deriving its key parameters. We found the peak I-band brightness to be Imax = 16.57 +- 0.10 mag, the maximum absolute I magnitude to be MmaxI = -18.79 +- 0.20, and the parameter dm15(B) specifying the width of the B-band light curve to be 1.46 +- 0.17 mag. The latter was derived using the relations between this parameter and dm40(I) and the time interval dtmax(I) between the two maxima in the I-band light curve. As has been found for previously observed, highly extinguished SNe Ia, a small value of 1.59 +- 0.07 was obtained here for the ratio Rv of the total-to-selective extinction ratio for SN 2002cv, which implies a small mean size for the grains along the line of sight toward us. Since it was found for SN 2002bo a canonical value of 3.1, here we present a clear evidence of different dust properties inside NGC 3190.Comment: 18 pages, 18 figures. Accepted for publication in MNRAS. Added co-author

    Another look at the BL Lacertae flux and spectral variability

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    The GLAST-AGILE Support Program (GASP) of the Whole Earth Blazar Telescope (WEBT) monitored BL Lacertae in 2008-2009 at radio, near-IR, and optical frequencies. During this period, high-energy observations were performed by XMM-Newton, Swift, and Fermi. We analyse these data with particular attention to the calibration of Swift UV data, and apply a helical jet model to interpret the source broad-band variability. The GASP-WEBT observations show an optical flare in 2008 February-March, and oscillations of several tenths of mag on a few-day time scale afterwards. The radio flux is only mildly variable. The UV data from both XMM-Newton and Swift seem to confirm a UV excess that is likely caused by thermal emission from the accretion disc. The X-ray data from XMM-Newton indicate a strongly concave spectrum, as well as moderate flux variability on an hour time scale. The Swift X-ray data reveal fast (interday) flux changes, not correlated with those observed at lower energies. We compare the spectral energy distribution (SED) corresponding to the 2008 low-brightness state, which was characterised by a synchrotron dominance, to the 1997 outburst state, where the inverse-Compton emission was prevailing. A fit with an inhomogeneous helical jet model suggests that two synchrotron components are at work with their self inverse-Compton emission. Most likely, they represent the radiation from two distinct emitting regions in the jet. We show that the difference between the source SEDs in 2008 and 1997 can be explained in terms of pure geometrical variations. The outburst state occurred when the jet-emitting regions were better aligned with the line of sight, producing an increase of the Doppler beaming factor. Our analysis demonstrates that the jet geometry can play an extremely important role in the BL Lacertae flux and spectral variability.Comment: 12 pages, 10 figures, accepted for publication in A&
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