As is well known, the positron was discovered in August 1932 by Carl Anderson while studying cloud chamber tracks left by cosmic rays. Far less known is the fact that a few months before Anderson's discovery, in April 1932, Fr茅d茅ric Joliot and Ir猫ne Curie had missed an opportunity to discover the positron during a nuclear physics experiment. One year later, in April 1933, the French researchers eventually succeeded in discovering the mechanism of positron鈥揺lectron pair production. The complex relationship between Anderson's discovery of the positron, Joliot and Curie's missed discovery, and their following work on the pair production is discussed here in detail.

In this paper we estimate the causal impacts of disability onset on labour market outcomes up to four years after onset using longitudinal data from the Household Income and Labour Dynamics Australia (HILDA) survey and difference-in-difference propensity score matching techniques. We find lasting negative impacts on full-time employment, which is linked more to people foregoing opportunities to move to full-time work rather than downshifting from full-time to part-time work. Impacts are greater for those without post-school qualifications because they face poor prospects once dislocated from work. These results point to the importance of prevention and vocational rehabilitation programs that are targeted at low- skilled workers.

Three new highly oxygenated chromene derivatives, oxirapentyns B-D (1-3) and one known oxirapentyn A (4) were isolated from the lipophilic extract of the marine-derived fungus Isaria felina KMM 4639. The structures of compounds 1-3 were determined based on spectroscopic methods. The absolute configuration of oxirapentyn B (1) as 2R, 4S, 5S, 6S, 7R, 8S, 9S was established by a combination of modified Mosher's method, X-ray analysis, and NOESY data. Oxirapentyn A (4) showed weak cytotoxicity against SK-Mel-5, SK-Mel-28 human malignant melanoma, and T-47D human breast cancer cell lines. (C) 2012 Phytochemical Society of Europe. Published by Elsevier B.V. All rights reserved.

The Board of Governors of the Federal Reserve System, under delegated authority from the Office of Management and Budget (OMB), proposes to extend for three years, with revision, the following voluntary Payments Systems Surveys (OMB No. 7100-0332): ? the Ad Hoc Payments Systems Survey (FR 3054a) ? the Currency Functionality and Perception Survey (FR 3054d) This family of reports also contains the following surveys, which the Federal Reserve proposes to extend without revision: ? the Currency Quality Sampling Survey (FR 3054b) ? the Currency Quality Survey (FR 3054c) The FR 3054a is an event-driven survey used to obtain information specifically tailored to the Federal Reserve's operational and fiscal agency responsibilities. The FR 3054a may be conducted independently by the Federal Reserve Board or jointly with another government agency, a Federal Reserve Bank, or a private firm. The FR 3054b is an annual survey used to assess the quality of currency in circulation and may be conducted by the Federal Reserve Board, jointly with the Federal Reserve Bank of San Francisco's Cash Product Office (CPO), the Federal Reserve Bank of Richmond's Currency Technology Office (CTO), and each Federal Reserve Bank's cash department. The FR 3054c is a semi-annual survey used to determine depository institutions' and Banknote Equipment Manufacturers' (BEMs) opinions of currency quality and may be conducted jointly with the CPO and CTO. The FR 3054d is an annual survey used to assess the functionality of Federal Reserve notes in banknote handling equipment. The data collected from the FR 3054d are used as inputs for future designs of Federal Reserve notes. The FR 3054d may be conducted jointly with the U. S. Treasury's Bureau of Engraving and Printing (BEP) and the CTO. The FR 3054a, FR 3054b, FR 3054c, and FR 3054d are sent to financial and nonfinancial businesses. The Federal Reserve uses data collected from these surveys to determine (1) demand for currency and coin, (2) market preferences regarding currency quality, (3) quality of currency in circulation, (4) features used by the public and bank note authentication equipment to denominate and authenticate bank notes, and (5) whether changes to Federal Reserve Bank sorting algorithms are necessary to ensure that currency in circulation remains fit for commerce. The Federal Reserve proposes to revise the FR 3054a by (1) adding individuals and law enforcement agencies to its respondent panel, (2) reducing the annual frequency from 10 times to 1 time per year, (3) reducing the estimated time to complete a survey from 15 hours to 0.75 hours, and (4) increasing the number of respondents from 100 to 12,000. The Federal Reserve proposes to revise the FR 3054d by (1) renaming the survey as Currency Functionality and Perception Survey, (2) adding individuals to its respondent panel, (3) increasing the frequency of the survey from one time per year to four times per year, (4) reducing the estimated time to complete the survey from 48 hours to 2.5 hours, and (5) increasing the number of respondents from 20 to 250. The total current annual burden for the Payment Systems Surveys is 17,550 hours and would decrease by 4,460 hours for a proposed annual burden of 13,090 hours.

Few documented work were devoted to the study blood groups in Guinea. The objective of this study was to determine the phenotypical and genic frequencies of antigens of ABO and rhesus D systems in the guinean population.