21 research outputs found

    State of the climate in 2013

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    In 2013, the vast majority of the monitored climate variables reported here maintained trends established in recent decades. ENSO was in a neutral state during the entire year, remaining mostly on the cool side of neutral with modest impacts on regional weather patterns around the world. This follows several years dominated by the effects of either La Niña or El Niño events. According to several independent analyses, 2013 was again among the 10 warmest years on record at the global scale, both at the Earths surface and through the troposphere. Some regions in the Southern Hemisphere had record or near-record high temperatures for the year. Australia observed its hottest year on record, while Argentina and New Zealand reported their second and third hottest years, respectively. In Antarctica, Amundsen-Scott South Pole Station reported its highest annual temperature since records began in 1957. At the opposite pole, the Arctic observed its seventh warmest year since records began in the early 20th century. At 20-m depth, record high temperatures were measured at some permafrost stations on the North Slope of Alaska and in the Brooks Range. In the Northern Hemisphere extratropics, anomalous meridional atmospheric circulation occurred throughout much of the year, leading to marked regional extremes of both temperature and precipitation. Cold temperature anomalies during winter across Eurasia were followed by warm spring temperature anomalies, which were linked to a new record low Eurasian snow cover extent in May. Minimum sea ice extent in the Arctic was the sixth lowest since satellite observations began in 1979. Including 2013, all seven lowest extents on record have occurred in the past seven years. Antarctica, on the other hand, had above-average sea ice extent throughout 2013, with 116 days of new daily high extent records, including a new daily maximum sea ice area of 19.57 million km2 reached on 1 October. ENSO-neutral conditions in the eastern central Pacific Ocean and a negative Pacific decadal oscillation pattern in the North Pacific had the largest impacts on the global sea surface temperature in 2013. The North Pacific reached a historic high temperature in 2013 and on balance the globally-averaged sea surface temperature was among the 10 highest on record. Overall, the salt content in nearsurface ocean waters increased while in intermediate waters it decreased. Global mean sea level continued to rise during 2013, on pace with a trend of 3.2 mm yr-1 over the past two decades. A portion of this trend (0.5 mm yr-1) has been attributed to natural variability associated with the Pacific decadal oscillation as well as to ongoing contributions from the melting of glaciers and ice sheets and ocean warming. Global tropical cyclone frequency during 2013 was slightly above average with a total of 94 storms, although the North Atlantic Basin had its quietest hurricane season since 1994. In the Western North Pacific Basin, Super Typhoon Haiyan, the deadliest tropical cyclone of 2013, had 1-minute sustained winds estimated to be 170 kt (87.5 m s-1) on 7 November, the highest wind speed ever assigned to a tropical cyclone. High storm surge was also associated with Haiyan as it made landfall over the central Philippines, an area where sea level is currently at historic highs, increasing by 200 mm since 1970. In the atmosphere, carbon dioxide, methane, and nitrous oxide all continued to increase in 2013. As in previous years, each of these major greenhouse gases once again reached historic high concentrations. In the Arctic, carbon dioxide and methane increased at the same rate as the global increase. These increases are likely due to export from lower latitudes rather than a consequence of increases in Arctic sources, such as thawing permafrost. At Mauna Loa, Hawaii, for the first time since measurements began in 1958, the daily average mixing ratio of carbon dioxide exceeded 400 ppm on 9 May. The state of these variables, along with dozens of others, and the 2013 climate conditions of regions around the world are discussed in further detail in this 24th edition of the State of the Climate series. © 2014, American Meteorological Society. All rights reserved

    Ca2+-dependent metarhodopsin inactivation mediated by calmodulin and NINAC myosin III

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    SummaryPhototransduction in flies is the fastest known G protein-coupled signaling cascade, but how this performance is achieved remains unclear. Here, we investigate the mechanism and role of rhodopsin inactivation. We determined the lifetime of activated rhodopsin (metarhodopsin = M∗) in whole-cell recordings from Drosophila photoreceptors by measuring the time window within which inactivating M∗ by photoreisomerization to rhodopsin could suppress responses to prior illumination. M∗ was inactivated rapidly (τ ∼20 ms) under control conditions, but ∼10-fold more slowly in Ca2+-free solutions. This pronounced Ca2+ dependence of M∗ inactivation was unaffected by mutations affecting phosphorylation of rhodopsin or arrestin but was abolished in mutants of calmodulin (CaM) or the CaM-binding myosin III, NINAC. This suggests a mechanism whereby Ca2+ influx acting via CaM and NINAC accelerates the binding of arrestin to M∗. Our results indicate that this strategy promotes quantum efficiency, temporal resolution, and fidelity of visual signaling

    Ambivalent statements in contingent valuation studies: inclusive response formats and giving respondents time to think

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    A recent concern in the valuation literature is the uncertainty respondents feel when posed with willingness-to-pay questions for environmental amenities in hypothetical market scenarios. Using a multiple-bounded discrete-choice format, the results indicate that respondents become less ambivalent when allowed considerable time to think about the valuation task before a response is elicited. In particular they tend to reduce the reported willingness to pay associated with low certainty of paying, hence resulting in more conservative welfare estimates. Implications for the application of environmental valuation techniques are discussed. Copyright 2007 The Author 2007 Australian Agricultural and Resource Economics Society Inc. and Blackwell Publishing Ltd .

    Problem-oriented policing in public housing: The Jersey City evaluation

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    This paper examines the impact of a problem-oriented policing project on serious crime problems in six public housing sites in Jersey City, New Jersey. Representatives from the police department and the local housing authority, social service providers, and public housing tenants formed six problem-solving teams. Using systematic documentation of the teams' activities and calls for police service, we examine changes in serious crime both across and within the six sites over a 2 1/2-year period. We find that problem-oriented policing, as compared with traditional policing strategies used before the problem-oriented policing project, led to fewer serious crime calls for service over time and that two public housing sites in particular succeeded in reducing violent, property, and vehicle-related crimes
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