University of California, Irvine

About: University of California, Irvine is a education organization based out in Irvine, California, United States. It is known for research contribution in the topics: Population & Galaxy. The organization has 47031 authors who have published 113602 publications receiving 5521832 citations. The organization is also known as: UC Irvine & UCI.

Unexpectedly high concentrations of molecular chlorine in coastal air

Abstract: The fate of many atmospheric trace species, including pollutants such as nitrogen oxides and some volatile organic compounds, is controlled by oxidation reactions In the daytime troposphere, these reactions are dominated by photochemically produced OH radicals; at night and in polluted environments, NO3 radicals are an important oxidant1 Ozone can contribute to the oxidation of atmospheric species during both day and night1 In recent years, laboratory investigations2,3,4, modelling studies5,6,7, measured Cl deficits in marine aerosols8 and species-nonspecific observations9,10,11 of gaseous inorganic chlorine compounds other than HCl have suggested that reactive halogen species may contribute significantly to—or even locally dominate—the oxidative capacity of the lower marine troposphere Here we report night-time observations of molecular chlorine concentrations at a North American coastal site during onshore wind flow conditions that cannot be explained using known chlorine chemistry The measured Cl2 mixing ratios range from <10 to 150 parts per 1012 (ppt), exceeding those predicted5 for marine air by more than an order of magnitude Using the observed chlorine concentrations and a simple photochemical box model, we estimate that a hitherto unrecognized chlorine source must exist that produces up to 330 ppt Cl2 per day The model also indicates that early-morning photolysis of molecular chlorine can yield sufficiently high concentrations of chlorine atoms to render the oxidation of common gaseous compounds by this species 100 times faster than the analogous oxidation reactions involving the OH radical, thus emphasizing the locally significant effect of chlorine atoms on the concentrations and lifetimes of atmospheric trace species in both the remote marine boundary layer and coastal urban areas

Purchasing Power Parity in the Long Run

Abstract: This paper re-examines the evidence on Purchasing Power Parity (PPP) in the long run. Previous studies have generally been unable to reject the hypothesis that the real exchange rate follows a random walk. If true, this implies that PPP does not hold. In contrast, this paper casts serious doubt on this random walk hypothesis. The results follow from more powerful estimation techniques, applied in a multilateral framework. Deviations from PPP, while substantial in the short run, appear to take about three years to be reduced in half

Agreed definitions and a shared vision for new standards in stroke recovery research: The Stroke Recovery and Rehabilitation Roundtable taskforce:

Abstract: The first Stroke Recovery and Rehabilitation Roundtable established a game changing set of new standards for stroke recovery research. Common language and definitions were required to develop an agreed framework spanning the four working groups: translation of basic science, biomarkers of stroke recovery, measurement in clinical trials and intervention development and reporting. This paper outlines the working definitions established by our group and an agreed vision for accelerating progress in stroke recovery research.