705 research outputs found

    Breit Hamiltonian and QED Effects for Spinless Particles

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    We describe a simplified derivation for the relativistic corrections of order α4\alpha^4 for a bound system consisting of two spinless particles. We devote special attention to pionium, the bound system of two oppositely charged pions. The leading quantum electrodynamic (QED) correction to the energy levels is of the order of α3\alpha^3 and due to electronic vacuum polarization. We analyze further corrections due to the self-energy of the pions, and due to recoil effects, and we give a complete result for the scalar-QED leading logarithmic corrections which are due to virtual loops involving only the scalar constituent particles (the pions); these corrections are of order α5lnα\alpha^5 \ln \alpha for S states.Comment: 12 pages, LaTeX; references added (J. Phys. B, in press

    Lying Behavior, Family Functioning and Adjustment in Early Adolescence

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    Item does not contain fulltextCommunication between children and parents has been the subject of several studies, examining the effects of, for example, disclosure and secrecy on adolescents' social relationships and adjustment. Less attention has paid to adolescent deception. We developed and tested a new instrument on lying behavior in a sample of 671 parent-adolescent couples. Analyses on the psychometric properties showed that this instrument had one principal component, and high internal consistency, item-total correlations and inter-item correlations. Lying was moderately associated with other indicators of parent-child communication, the quality of the parent-child relationship, and with parenting practices. In addition, frequent lying was moderately related to behavioral problems and emotional problems.10 p

    The state of the Martian climate

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    60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes

    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

    Human Illness from Avian Influenza H7N3, British Columbia

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    Avian influenza that infects poultry in close proximity to humans is a concern because of its pandemic potential. In 2004, an outbreak of highly pathogenic avian influenza H7N3 occurred in poultry in British Columbia, Canada. Surveillance identified two persons with confirmed avian influenza infection. Symptoms included conjunctivitis and mild influenzalike illness

    The pathogenic role of circulating Hashimoto's Thyroiditis-derived TPO-positive IgG on fetal loss in naïve mice

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    Problem: Antibody-mediated autoimmune diseases, such as autoimmune thyroid diseases (ATD), systemic lupus erythematosus (SLE), and antiphospholipid syndrome (APS), often are associated with recurrent fetal loss. One of the ATD is Hashimoto's thyroiditis which recently showed association with complications of pregnancy with increased levels of circulating autoantibodies reactive with epitopes on thyroid tissue such as thyroid peroxidase (anti-TPO). In retrospective study of sera analyses in patients with Hashimoto's thyroiditis, all patients had mainly elevated circulating anti-TPO autoantibodies. Aim: We assessed the potential of human anti-TPO highly positive IgG, derived from patients with Hashimoto's thyroiditis sera associated with complications of pregnancy, to cause directly complications of pregnancy in murine model. Method of study: Naïve ICR female mice, infused intravenously with 100 μg of anti-TPO-positive IgG, showed increased fetal loss and embryo small for date (P <.001) in comparison with mice passively transferred with commercial IgG or PBS. Moreover, we observed embryos small for date in the mice passively transferred with anti-TPO-positive IgG, exemplified by reduced weight of embryos and placentae (P =.001). Histopathological examination revealed delay in fetal development in 50% cases of anti-TPO-positive IgG-treated mice. Importantly, pathological changes in the transition zone, state of glycogen cells, and significant structural changes in the labyrinth part of placenta were observed in all anti-TPO-positive IgG samples. Conclusion: The current study shows in the first time, a direct proof of concept, on the association of human TPO-positive IgG from Hashimoto's thyroiditis patients on fetal loss induction in murine model
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