31,434 research outputs found

    Bombs Away: the First Mission on a Coastal Command Liberator

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    The U.S. Science and Technology Workforce

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    [Excerpt] In the 21st century, global competition and rapid advances in science and technology will challenge the scientific and technical proficiency of the U.S. workforce. Policymakers often discuss policy actions that could enhance the nation’s science and technology (S&T) workforce— deemed by some as essential to both meet U.S. workforce demands as well as to generate the new ideas that lead to improved and new industries that create jobs. The America COMPETES Act (P.L. 110-69) addresses concerns regarding the S&T workforce and STEM education, and the 111th Congress is debating funding for the programs authorized within it. Policymaker discussions tend to focus on three issues: demographic trends and the future S&T talent pool, the current S&T workforce and changing workforce needs, and the influence of foreign S&T students and workers on the U.S. S&T workforce. Many perspectives exist, however, on the supply and demand of scientists and engineers. Some question the fundamental premise that any action is necessary at all regarding U.S. competitiveness. They question whether or not the S&T workforce and STEM education are problems at all. The first issue of demographic trends and the future S&T talent pool revolves around whether the quality of science, technology, engineering and mathematics (STEM) education received by all Americans at the pre-college level is of sufficient quality that workers are available to satisfy current and future workforce needs. In response, some policymakers propose taking actions to increase the number of Americans interested in the S&T workforce. These policies are motivated by demographic trends that indicate the pool of future workers will be far more diverse than the current STEM workforce. Proposed policies would take actions to enhance the quality of STEM education these Americans receive so they are able to consider S&T careers, and to recruit them into the S&T workforce. The second issue regarding the current S&T workforce and changing workforce needs tend to focus on whether or not the number of Americans pursuing post-secondary STEM degrees is sufficient to meet future workforce needs compared to students in countries considered to be U.S. competitors. The goal of proposed policies responding to this concern to reinvigorate and retrain Americans currently trained in science and engineering who voluntarily or involuntarily are no longer part of the current STEM workforce. The third issue focuses on whether or not the presence of foreign S&T students and workers is necessary to meet the nation’s workforce needs and attract the best and brightest to bring their ideas to the United States, or if the presence of such individuals adversely affects the U.S. S&T students and workers. Policy discussions focus on immigration policy, primarily increasing the ability of foreign STEM students currently in U.S. universities to more easily obtain permanent admission, and increasing the number of temporary worker visas available so more talent from abroad can be recruited to the United States. The challenge facing policymakers when making decisions regarding the S&T workforce is that science, engineering, and economic conditions are constantly changing, both in terms of workforce needs as well as the skills the STEM workforce needs to be marketable relative to demand

    Female Fighting and Host Competition Among Four Sympatric Species of \u3ci\u3eMelittobia\u3c/i\u3e (Hymenoptera: Eulophidae)

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    Melittobia is a genus of parasitic wasps well known for high levels of inbreeding and violent male combat. Casual observations of groups of sisters of M. femorata placed with hosts revealed a surprising incidence of body mutilations (broken or missing tarsi, antennae, and wings). Replicated conspecific groups of 1, 2, or 3 females of M. femorata, M. digitata, and M. australica and interspecific groups of M. femorata and M. australica (2:1) were observed over their first 10 days in newly established cultures, and the incidence of mutilation was recorded. In some groups females were dye-fed, allowing us to subsequently chart their individual activity patterns on or near the host based on patterns of their colored fecal droppings. For M. australica and M. digitata, no conspecific females in any group size ever showed mutilation. However, in M. femorata nearly 3/4ths of the females in conspecific groups of two or three acquired body damage beginning about the time of first oviposition on the host. In 4 of 5 replicates of the interspecific groups, M. femorata females killed the female of M. australica. Patterns of dyed fecal droppings that developed over several days showed that individual females in groups of both M. femorata and M. australica increasingly restricted their activities to a small portion of the host. These “micro” territories were non-overlapping and appeared to be actively defended. In contrast, M. digitata females in groups never displayed obvious territoriality or interference. Possible reasons for these differences in female behavior are discussed

    The Star Formation Histories and Efficiencies of Two Giant HII Regions in M33

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    UBVUBV photometry is used to re-identify the OB associations which power the two most luminous HII regions in M33, NGC 604 and NGC 595. There is a significant difference (2-3 Myr) in the ages of the most recent star formation episode in these two regions, while NGC 595 also has undergone a prior episode of star formation (10-15 Myr ago). These data, combined with the presence of molecular clouds in the heart of NGC 604, suggest that molecular clouds may survive at least one intense episode of massive star formation. The star formation efficiencies (mass of stars per mass of gas) of these two HII regions are up to a factor of 3 larger than the average efficiency in the inner disk of M33 or in Galactic molecular clouds, but are still only 2-5\%.Comment: 26 pages including 2 figures, uuencoded compressed postscript file (Figure 1 not available electronically). Accepted to Ap
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