58 research outputs found

    Internally folded expanded metal electrode for battery construction

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    A battery system is disclosed which includes folded grids of expanded metal inserted through non-conductive substrates and pasted with electrochemically active materials. In the most preferred embodiment, a frame is provided with a plastic insert, and slots are provided in the latter to receive the expanded metal grid. After suitable coinage of the grid and insertion through the plastic film, the grid is sealed and pasted on opposite sides with positive and negative active material. A battery is assembled using one or a plurality of the resulting electrode elements, with separators, to produce a high-power, lead-acid battery. The folded grid provides many of the design benefits of standard bipolar construction

    Politics, sharing and emotion in microblogs

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    Abstract—In political contexts, it is known that people act as “motivated reasoners”, i.e., information is evaluated first for emotional affect, and this emotional reaction influences later deliberative reasoning steps. As social media becomes a more and more prevalent way of receiving political information, it becomes important to understand more completely the interaction between information, emotion, social community, and informationsharing behavior. In this paper, we describe a high-precision classifier for politically-oriented tweets, and an accurate classifier of a Twitter user’s political affiliation. Coupled with existing sentiment-analysis tools for microblogs, these methods enable us to systematically study the interaction of emotion and sharing in a large corpus of politically-oriented microblog messages, collected from just before the 2012 US presidential election. In particular, we seek to understand how information sharing is influenced by the political affiliation of the sender and receiver of a message, and the sentiment associated with the message

    Washington CCD Photometry of the Globular Cluster System of the Giant Elliptical Galaxy M60 in Virgo

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    We present a photometric study of the globular clusters in the giant elliptical galaxy M60 in the Virgo cluster, based on deep, relatively wide field Washington CT_1 CCD images. The color-magnitude diagram reveals a significant population of globular clusters in M60, and a large number of young luminous clusters in NGC 4647, a small companion spiral galaxy north-west of M60. The color distribution of the globular clusters in M60 is clearly bimodal, with a blue peak at (C-T_1)=1.37, and a red peak at (C-T_1)=1.87. We derive two new transformation relations between the (C-T_1)_0 color and [Fe/H] using the data for the globular clusters in our Galaxy and M49. Using these relations we derive the metallicity distribution of the globular clusters in M60, which is also bimodal: a dominant metal-poor component with center at [Fe/H]=-1.2, and a weaker metal-rich component with center at [Fe/H]=-0.2. The radial number density profile of the globular clusters is more extended than that of the stellar halo, and the radial number density profile of the blue globular clusters is more extended than that of the red globular clusters. The number density maps of the globular clusters show that the spatial distribution of the blue globular clusters is roughly circular, while that of the red globular cluster is elongated similarly to that of the stellar halo. We estimate the total number of the globular clusters in M60 to be 3600+/-500$,and the specific frequency to be S_N=3.8+/-0.4. The mean color of the bright blue globular clusters gets redder as they get brighter in both the inner and outer region of M60. This blue tilt is seen also in the outer region of M49, the brightest Virgo galaxy. Implications of these results are discussed.Comment: 32 pages, 22 figues, Accepted by Ap

    A Quantitative Link Between Globular Clusters and the Stellar Halos in Elliptical Galaxies

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    This paper explores the quantitative connection between globular clusters and the diffuse stellar population of the galaxies they are associated with. Both NGC 1399 and NGC 4486 (M87) are well suited for this kind of analysis due to their large globular cluster populations. The main assumption of our Monte Carlo based models is that each globular cluster is formed along with a given diffuse stellar mass that shares the same spatial distribution, chemical composition and age. The main globular clusters subpopulations, that determine the observed bimodal colour distribution, are decomposed avoiding a priori parametric (e.g. Gaussian) fits and using a new colour (C-T1)-metallicity relation. The eventual detectability of a blue tilt in the colour magnitude diagrams of the blue globulars subpopulation is also addressed. A successful link between globular clusters and the stellar galaxy halo is established by assuming that the number of globular clusters per associated diffuse stellar mass t is a function of total abundance [Z/H] and behaves as t=gamma*exp(delta[Z/H]) (i.e. increases when abundance decreases).Comment: 19 pages, 24 figures and 4 tables. Accepted for publication in MNRA

    The influence of antidiabetic medications on the development and progression of prostate cancer

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    AbstractBackgroundThe development of prostate tumors has been linked to co-morbid diabetes mellitus (DM) in several studies, potentially through the stimulation of insulin-like growth factor receptor (IGFR). This study evaluates the effect of anti-diabetic medication use on the development of high grade tumors and time to tumor progression compared to non-diabetics.MethodsThis retrospective, nested case control study identified patients with prostate cancer (PCa) from the Kentucky Medicaid Database. Cases were diagnosed with PCa and DM and using at least one of the following antidiabetic medications; sulfonylureas, insulin, metformin or TZDs. Cases were further stratified on their insulin exposure resulting from therapy. Controls were those with PCa without DM or any anti-diabetic medications.ResultsThe use of metformin or TZDs trended toward decreased odds of high-grade tumors and decreased risk of progression, while sulfonylureas and high-dose insulin tended toward an increased odds of high-grade tumors and increase the risk of progression compared to non-diabetics.ConclusionsFuture studies should be conducted to further evaluate the effects of anti-diabetic medications on tumor grade and time to prostate cancer progression

    A global phylogeny of butterflies reveals their evolutionary history, ancestral hosts and biogeographic origins

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    Butterflies are a diverse and charismatic insect group that are thought to have evolved with plants and dispersed throughout the world in response to key geological events. However, these hypotheses have not been extensively tested because a comprehensive phylogenetic framework and datasets for butterfly larval hosts and global distributions are lacking. We sequenced 391 genes from nearly 2,300 butterfly species, sampled from 90 countries and 28 specimen collections, to reconstruct a new phylogenomic tree of butterflies representing 92% of all genera. Our phylogeny has strong support for nearly all nodes and demonstrates that at least 36 butterfly tribes require reclassification. Divergence time analyses imply an origin similar to 100 million years ago for butterflies and indicate that all but one family were present before the K/Pg extinction event. We aggregated larval host datasets and global distribution records and found that butterflies are likely to have first fed on Fabaceae and originated in what is now the Americas. Soon after the Cretaceous Thermal Maximum, butterflies crossed Beringia and diversified in the Palaeotropics. Our results also reveal that most butterfly species are specialists that feed on only one larval host plant family. However, generalist butterflies that consume two or more plant families usually feed on closely related plants

    Exploring South Africa's southern frontier : a 20-year vision for polar research through the South African National Antarctic Programme

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    Antarctica, the sub-Antarctic islands and surrounding Southern Ocean are regarded as one of the planet’s last remaining wildernesses, ‘insulated from threat by [their] remoteness and protection under the Antarctic Treaty System’. Antarctica encompasses some of the coldest, windiest and driest habitats on earth. Within the Southern Ocean, sub-Antarctic islands are found between the Sub-Antarctic Front to the north and the Polar Front to the south. Lying in a transition zone between warmer subtropical and cooler Antarctic waters, these islands are important sentinels from which to study climate change. A growing body of evidence now suggests that climatically driven changes in the latitudinal boundaries of these two fronts define the islands’ short- and long-term atmospheric and oceanic circulation patterns. Consequently, sub-Antarctic islands and their associated terrestrial and marine ecosystems offer ideal natural laboratories for studying ecosystem response to change. For example, a recent study indicates that the shift in the geographical position of the oceanic fronts has disrupted inshore marine ecosystems, with a possible impact on top predators. Importantly, biotic responses are variable as indicated by different population trends of these top predators. When studied collectively, these variations in species’ demographic patterns point to complex spatial and temporal changes within the broader sub-Antarctic ecosystem, and invite further examination of the interplay between extrinsic and intrinsic drivers.http://www.sajs.co.zaam2017GeneticsMammal Research InstituteZoology and Entomolog

    American Gut: an Open Platform for Citizen Science Microbiome Research

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    McDonald D, Hyde E, Debelius JW, et al. American Gut: an Open Platform for Citizen Science Microbiome Research. mSystems. 2018;3(3):e00031-18

    Craking the New GRE 2012 : Proven Techniques for a higher Score

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