357 research outputs found
Urban Welfare-to-Work Transitions in the 1990s: Patterns in Six Urban Areas
This report focuses on patterns of welfare use and employment for welfare leavers for central counties in each of six metropolitan areas
Asymmetric labor force participation decisions over the business cycle: evidence from U.S. microdata
The purpose of this paper is to explore the microfoundations of the observed asymmetric movement in aggregate unemployment rates. Using U.S. data, we find that individual labor force participation responds asymmetrically to changes in local labor market conditions, consistent with the pattern of movements in the aggregate unemployment rate. Differences in the asymmetry and sensitivity of labor force participation decisions are found across gender, age, and education groups, and these differences are used to anticipate changes in the aggregate movements as population characteristics change over time.
Separation and radiochemical study of molybdic and tungstic oxides
In the work presented here, tungsten and molybdenum are precipitated and chemically separated as much as is possible. The products are collected and irradiated with thermal neutrons and the concentration of tungsten determined. In this way only that tungsten forming a complex or dissolving into the molybdenum crystal will be measured
PhD
dissertationEarlier studies have demonstrated the peroxidase oxidation of the delta8-ergolines agroclavine and elymoclavine to their respective 10-hydroxy-delta9, and other derivatives. It was suggested that peroxidase may be involved in the biosynthesis of some of the ergot alkaloids. The important biosynthetic intermediate chanoclavine-I is a tricyclic analog of agroclavine and elymoclavine and might be expected to undergo similar peroxidase-catalyzed oxidations but the expected products have not observed in nature. However, the biosynthesis of the recently isolated rugulovasines could conceivably involve at some stage 10-hydrosylation such as occurs in the peroxidase oxidation of agroclavine and elymoclavine. The main objective of this investigation was to study the effect of peroxidase on chanoclavine derivatives in an attemp to clarify the possible role of this enzyme in the biosynthesis of the ergot alkaloids. The study later led in some unanticipated directions which resulted in the development of a new synthesis of lysergic acid derivatives and the isolation and synthesis of a new secoergoline alkaloid. Chanoclavine-I (and isochanoclavine-I) was found to be readily oxidized by horseradish peroxidase. However, in contrast to agroclavine and elymoclavine, this reaction provided a complex mixture of products which consisted largely of non-ergolines and only small amounts of unstable ergolines which could not be isolated and characterized. Several observations suggested that oxidation was occurring primarily at C-10 as in the tetracyclic alkaloids and that an unstable 10-hydroxy derivative was formed. The ease of decomposition of this key intermediate in ergoline biosynthesis suggested, however, that peroxidase may be more important in the biological degradation and lack of accumulation of ergolines than in their biosynthesis. Chanoclavine-I-aldehyde was rather unexpectedly found to be resistant to the action of peroxidase. For this reason, attempts were made to synthesize and determine the effects of the enzyme on its tetracyclic analog, delta-8-lysergaldehyde. All efforts to prepare this compound from elymoclavine resulted in failure as they had earlier for other investigators. However, these studies did result in the development of a three step synthesis of lysergic acid methyl ester from elymoclavine in an overall yield of approximately 30%. This is the first successful attempt to convert an ergot clavinet to a lysergic acid derivative in reasonable yield and the results indicate that the method can be used to synthesize a variety of other lysergic acid derivatives. An unidentified "ergoline acid" had been previously reported as the major alkaloid in the seeds of Ipomoea violacea var. "Pearly Gates." Several suggested that this may be a chanoclavine acid derivative. The alkaloid was isolated from the seeds of this plant in about 0.01% yield and was characterized as chanoclavine-I-acid. The compound was also synthesized from chanoclavine-I-acid. The compound was also synthesized from chanoclavine-I using a modification of the procedure used for the synthesis of lysergic acid methyl ester. Chanoclavine-I-acid was also detected in the seed of I. violacea varieties "Heavenly Blue" and "Flying Saucers" but no in those of Argyreia nervosa which suggests that it may be of value in the chemotaxonomy of the convolvulaceae family. The alkaloid was also found in small amounts of a strain of Penicillium islandicum along with chanoclavine-I and the previously reported rugulova sines. Interestingly, chanoclavine-I-aldehyde was also detected in cultures of this proposed intermediate in ergoline biosynthesis has been detected in nature
It's who you are and what you do: explaining the IT industry wage premium
The information technology (IT) boom dramatically boosted the rapid growth of the U.S. economy during the 1990s, contributing 1.4 percentage points of the 4.6 percent national average real gross domestic product growth from 1996 to 2000. As the IT boom went bust in 2001, however, the IT sector’s influence on the economy dwindled. ; But a lingering effect of the IT boom may still be apparent in the wages of IT workers. This article explores the extent to which variations in wages between IT-producing and non-IT industries can be accounted for by differences in wages paid to IT-related occupations. ; Using data for 1996 to 2002 from the Current Population Survey’s Earner Study, the authors study a sample of more than 845,000 U.S. workers aged eighteen to sixty-four. The sample is categorized according to individuals’ primary job and is divided into nine industry groups—three IT-related and six non-IT-related. ; The analysis shows that the average wage of IT occupations is greater than for non-IT occupations irrespective of industry. Individual worker characteristics such as years of education may account for some of this wage differential. But even after such characteristics and occupational differences are controlled for, workers in IT-producing industries still enjoy a wage premium over workers in other sectors.
Earnings on the information technology roller coaster: insight from matched employer-employee data
This paper uses matched employer-employee data for the state of Georgia to examine workers’ earnings experience through the information technology (IT) sector’s employment boom of the mid-1990s and its bust in the early 2000s. The results show that even after controlling for individual characteristics before the sector’s boom, transitioning out of the IT sector to a non-IT industry generally resulted in a large wage penalty. However, IT service workers who transitioned to a non-IT industry still fared better than those who took a non-IT employment path. For IT manufacturing workers, there is no benefit to having worked in tech, likely because of the nontransferability of manufacturing experience to other industries.
The ups and downs of jobs in Georgia: what can we learn about employment dynamics from state administrative data?
This paper demonstrates how state administrative data (from Georgia) can be used to decompose net employment growth in order to track establishment births, deaths, contractions, and expansions over time. Even though net employment growth can look quite similar across industries, the composition of that employment change can look quite different. The panel nature of the data allow the authors to see that overall lack of expansion and continued contraction among large establishments were the driving forces behind the weak employment growth immediately following the 2001 recession.
The push-pull effects of the information technology boom and bust: insight from matched employer-employee data
This paper examines the inflow and outflow of workers to different industries in Georgia during the information technology (IT) boom of the 1990s and the subsequent bust. Workers in the software and computer services industry were much more likely to have been absent from the Georgia workforce prior to the boom but were no more likely than workers from other industries to have exited the workforce during the bust. Consequently, the Georgia workforce likely experienced a net gain in worker human capital as a result of being an area of concentration of IT-producing activity during the IT boom.
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