965 research outputs found

    The heartbeat of the city

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    Human activity is organised around daily and weekly cycles, which should, in turn, dominate all types of social interactions, such as transactions, communications, gatherings and so on. Yet, despite their strategic importance for policing and security, cyclical weekly patterns in crime and road incidents have been unexplored at the city and neighbourhood level. Here we construct a novel method to capture the weekly trace, or "heartbeat" of events and use geotagged data capturing the time and location of more than 200,000 violent crimes and nearly one million crashes in Mexico City. On aggregate, our findings show that the heartbeats of crime and crashes follow a similar pattern. We observe valleys during the night and peaks in the evening, where the intensity during a peak is 7.5 times the intensity of valleys in terms of crime and 12.3 times in terms of road accidents. Although distinct types of events, crimes and crashes reach their respective intensity peak on Friday night and valley on Tuesday morning, the result of a hyper-synchronised society. Next, heartbeats are computed for city neighbourhood 'tiles', a division of space within the city based on the distance to Metro and other public transport stations. We find that heartbeats are spatially heterogeneous with some diffusion, so that nearby tiles have similar heartbeats. Tiles are then clustered based on the shape of their heartbeat, e.g., tiles within groups suffer peaks and valleys of crime or crashes at similar times during the week. The clusters found are similar to those based on economic activities. This enables us to anticipate temporal traces of crime and crashes based on local amenities

    The Effect of Soluble Uterine Factors on Porcine Embryo Development Within a Three-Dimensional Alginate Matrix System

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    Between day 10 and 12 of gestation in the pig, the embryo undergoes a dramatic morphological change, known as elongation. During elongation the embryo produces and secretes estrogen, which serves as a key signal for maternal recognition of pregnancy. The uterine environment prepares for embryo elongation and implantation by releasing nutrients, metabolites, and hormones in a time-dependent manner relative to paracrine signals from the conceptus (i.e., estrogen) and endocrine/paracrine signals within the endometrium (i.e., progesterone). Despite advances in identification of specific uterine factors present throughout pregnancy in the pig, little is known about the exact mechanisms by which porcine embryos elongate normally, or how this elongation is altered during embryonic loss. Previously, our laboratory has established an in vitro culture system using alginate hydrogels as a three-dimensional (3-D) matrix to support the development of pre-implantation porcine embryos in base serum media without the addition of hormones. The objective of the current study was to improve our 3-D system and determine if uterine flushes from day 9 or 10 of gestation were capable of supporting in vitro embryonic development of in vivo-developed day 9 porcine embryos using the 3- D alginate culture system. Embryos collected on day 9 of gestation were assigned to be cultured in pooled day 9 flushes, day 10 flushes, or base serum media for five days within 0.7% alginate gels. Our results demonstrate that uterine flushes from day 9 or 10 of gestation supported embryonic development in our 3-D hydrogel system, similar to that from embryos cultured in base serum media. These results illustrate that soluble factors present in uterine flushings at day 9 or 10 of gestation support in vitro embryonic development within our 3-D alginate culture system. Developing better scientific understanding of the factors that regulate embryo elongation and early embryonic mortality can be useful for developing strategies to improve sow productivity and increase the profitability of swine production

    A Common Software Configuration Management System for CERN SPS and LEP Accelerators and Technical Services

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    Software configuration management activities are crucial to assure the integrity of current operational and the quality of new software either being developed at CERN or outsourced. The functionality of the present management system became insufficient with large maintenance overheads. In order to improve our situation, a new software configuration management system has been set up. It is based on Razor, a commercial tool, which supports the management of file versions and operational software releases, along with integrated problem reporting capabilities. In addition to the basic tool functionality, automated procedures were custom made, for the installation and distribution of operational software. Policies were developed and applied over the software development life cycle to provide visibility and control. The system ensures that, at all times, the status and location of all deliverable versions are known, the state of shared objects is carefully controlled and unauthorised changes prevented. It provides a managed environment for software development, in various domains of the SPS and LEP CERN accelerators, and the technical services, automating code and lifecycle management. This paper outlines the reasons for selecting the chosen tool, the implementation of the system, the problems solved and the final goals achieved

    Assessment of Endocrine and Gonadal Condition of Male Largemouth Bass from Lake Mead, Nevada

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    Las Vegas Bay (LVB) of Lake Mead receives combined flows of tertiary treated wastewater effluent, urban runoff, and groundwater from the Las Vegas metropolitan area. This study examined the potential for endocrine disrupting effects of these anthropogenic inputs on male largemouth bass (Micropterus salmoides). Adult male bass were collected at two sites within Lake Mead: Overton Arm (OA, reference site), and Las Vegas Bay (LVB). Post-spawn fish were collected in July 2007 (n = 6-10 per site) and pre-spawn fish in March 2008 (n = 13 per site). Post-spawn fish were characterized by regressed testes whereas pre-spawn bass had full-grown gonads. Mean fish lengths and weights did not vary between sites or sampling times. Pre-spawn LVB males had lower plasma 11-ketotestosterone (KT), higher estradiol-17β (E2), higher E2/KT ratio, higher hepatosomatic index (ratio of liver to body weight), higher hematocrit values, and higher condition factor compared to OA males. However, no significant differences were evident in the gonadosomatic index (ratio of testes to body weight) of either pre-or post-spawn males from the two sites. In post-spawn males, no significant site-associated differences were detected for any of the parameters measured. Overall, these results suggest the existence of site-specific environmental influences on several indices of endocrine condition and health of pre-spawn male largemouth bass in Lake Mead, and are generally consistent with outcomes from previous studies that suggested the occurrence of altered endocrine and reproductive condition in male common carp from LVB

    Spectral optical monitoring of the double peaked emission line AGN Arp 102B: II. Variability of the broad line properties

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    We investigate a long-term (26 years, from 1987 to 2013) variability in the broad spectral line properties of the radio galaxy Arp 102B, an active galaxy with broad double-peaked emission lines. We use observations presented in Paper I (Shapovalova et al. 2013) in the period from 1987 to 2011, and a new set of observations performed in 2012--2013. To explore the BLR geometry, and clarify some contradictions about the nature of the BLR in Arp 102B we explore variations in the Hα\alpha and Hβ\beta line parameters during the monitored period. We fit the broad lines with three broad Gaussian functions finding the positions and intensities of the blue and red peaks in Hα\alpha and Hβ\beta. Additionally we fit averaged line profiles with the disc model. We find that the broad line profiles are double-peaked and have not been changed significantly in shapes, beside an additional small peak that, from time to time can be seen in the blue part of the Hα\alpha line. The positions of the blue and red peaks { have not changed significantly during the monitored period. The Hβ\beta line is broader than Hα\alpha line in the monitored period. The disc model is able to reproduce the Hβ\beta and Hα\alpha broad line profiles, however, observed variability in the line parameters are not in a good agreement with the emission disc hypothesis. It seems that the BLR of Arp 102B has a disc-like geometry, but the role of an outflow can also play an important role in observed variation of the broad line properties.Comment: 17 pages, Accepted for publication in A&

    Origin of Silicic Volcanic Rocks in Central Costa Rica: A Study of a Chemically Variable Ash-Flow Sheet in the TiribĂ­ Tuff

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    Chemical heterogeneities of pumice clasts in an ash-flow sheet can be used to determine processes that occur in the magma chamber because they represent samples of magma that were erupted at the same time. The dominant ash-flow sheet in the Tiribí Tuff contains pumice clasts that range in composition from 55.1 to 69.2 wt% SiO2. It covers about 820 km2 and has a volume of about 25 km3 dense-rock equivalent (DRE). Based on pumice clast compositions, the sheet can be divided into three distinct chemical groupings: a low-silica group (55.1–65.6 wt% SiO2), a silicic group (66.2–69.2 wt% SiO2), and a mingled group (58.6–67.7 wt% SiO2; all compositions calculated 100% anhydrous). Major and trace element modeling indicates that the low-silica magma represents a mantle melt that has undergone fractional crystallization, creating a continuous range of silica content from 55.1–65.6 wt% SiO2. Eu/Eu*, MREE, and HREE differences between the two groups are not consistent with crystal fractionation of the low-silica magma to produce the silicic magma. The low-silica group and the silicic group represent two distinct magmas, which did not evolve in the same magma chamber. We suggest that the silicic melts resulted from partial melting of relatively hot, evolved calc-alkaline rocks that were previously emplaced and ponded at the base of an over-thickened basaltic crust. The mingled group represents mingling of the two magmas shortly before eruption. Electronic supplementary material to this paper can be obtained by using the Springer LINK server located at http://dx.doi.org/10.1007/s00445-001-0188-8

    Coffee Production: An Analysis of Opportunities for Competitiveness

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    This study involved rural properties of the Brazilian Cerrado, which are necessarily consistent with the requirements of good agricultural practices for quality, innovation, and technology in the production and management of properties. Based on the knowledge and information as value-added production factors, we sought to highlight the opportunities for improving competitiveness, and thus a review of the literature on competitiveness, knowledge, and information as a differential factor for production with added value, innovation, and territorial technology as well as entrepreneurship. With the data from the field study, the objective was to show how knowledge and information, applied in production and social capital, can leverage competitiveness. The analyzes carried out using AHP indicate that some initiatives already aid in the promotion of innovation and technology applied to production, making it necessary, however, to encourage knowledge and information among producers and other stakeholders collectively, for the best costs and results. They also point to the low concern of producers with training and other productivity improvement techniques, such as selective harvesting. Authenticated that the producers opt for the sale of their production via commodity, aiming to profit quickly. Reasons for this are, in the non-perception of value added (sales in commodity); in the absence of rural structure for the processing and harvesting of the coffee required for special sale; in the precariousness of collective export agents (cooperatives are dependent on traders) and deficiencies in management for positioning in the properties (most work in scale)

    OPTICAL SPECTROSCOPIC OBSERVATIONS OF GAMMA-RAY BLAZAR CANDIDATES. VI. FURTHER OBSERVATIONS FROM TNG, WHT, OAN, SOAR, AND MAGELLAN TELESCOPES

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    IndexaciĂłn: Web of ScienceBlazars, one of the most extreme classes of active galaxies, constitute so far the largest known population of.-ray sources, and their number is continuously growing in the Fermi catalogs. However, in the latest release of the Fermi catalog there is still a large fraction of sources that are classified as blazar candidates of uncertain type (BCUs) for which optical spectroscopic observations are necessary to confirm their nature and their associations. In addition, about one-third of the gamma-ray point sources listed in the Third Fermi-LAT Source Catalog (3FGL) are still unassociated and lacking an assigned lower-energy counterpart. Since 2012 we have been carrying out an optical spectroscopic campaign to observe blazar candidates to confirm their nature. In this paper, the sixth of the series, we present optical spectroscopic observations for 30 gamma-ray blazar candidates from different observing programs we carried out with the Telescopio Nazionale Galileo, William Herschel Telescope, Observatorio Astronomico Nacional, Southern Astrophysical Research Telescope, and Magellan. Telescopes. We found that 21 out of 30 sources investigated are BL Lac objects, while the remaining targets are classified as flat-spectrum radio quasars showing the typical broad emission lines of normal quasi-stellar objects. We conclude that our selection of gamma-ray blazar. candidates based on their multifrequency properties continues to be a successful way to discover potential low-energy counterparts of the Fermi. unidentified gamma-ray sources and to confirm the nature of BCUs.http://iopscience.iop.org/article/10.3847/0004-6256/151/4/95/met

    Smallholder Dairy Farmers in the Peruvian Andes Fulfilling the Role of Extension Agents

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    Dairy farming in the Peruvian Andes is mostly undertaken by smallholder farmers (4-6 cows/family) and of relatively recent development. In fact, over the last 2 decades dairy farming at high altitudes (3,500‒4200 masl) has grown rapidly, replacing the camelids and sheep farming that once predominated. Dairying growth has been catalysed by subsides from state and private organizations. It promotes high input systems based on feedlot technology. Compared to sheep and camelids farming, dairying at the Andes does not have yet an inherent local/indigenous knowledge associated to it. High altitude Andean ecosystems pose many constraints for dairy farming (hypoxia and high UV radiation, high variation between day and night temperatures, short rainy season, and hence shortage of feed and water; and not less importantly, accelerated climate change (CC)). Under these conditions, not only are productivity and profitability low, but there are high negative environmental impacts and poor animal welfare. In Peru, institutionalised research and extension (R&E) services are precarious. Research tackling current issues of high-altitude livestock farming is almost inexistent, whereas extension in support of farmers is dispersed, poorly funded, of short duration (a few months), focused on transfer of technology suitable to intensive farming systems, and has a high turnover of staff. A systems approach to address the complexity of Andean livestock farming development is lacking. The initiatives from the institutions promoting farming are directed to remediate recurrent problems (e.g., cold stress) or prioritise high cost, low impact activities (e.g., genetic improvement). Here, we present the successful experience of the New Zealand Peru Dairy Support Project (NZPDSP) to promote the adoption of improved low input pastoral dairying husbandry principles, where trained smallholder farmers play a key role as agents of change
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