28,423 research outputs found
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.
Wake in faint television meteors
The two component dustball model was used in numerical lag computation. Detached grain lag is typically less than 2 km, with expected wakes of a few hundred meters. True wake in television meteors is masked by apparent wake due to the combined effects of image persistence and blooming. To partially circumvent this problem, we modified a dual MCP intensified CID video system by addition of a rotating shutter to reduce the effective exposure time to about 2.0 ms. Preliminary observations showed that only 2 of 27 analyzed meteors displayed statistically significant wake
Ebolavirus is evolving but not changing: No evidence for functional change in EBOV from 1976 to the 2014 outbreak
The 2014 epidemic of Ebola virus disease (EVD) has had a devastating impact in West Africa. Sequencing of ebolavirus (EBOV) from infected individuals has revealed extensive genetic variation, leading to speculation that the virus may be adapting to humans, accounting for the scale of the 2014 outbreak. We computationally analyze the variation associated with all EVD outbreaks, and find none of the amino acid replacements lead to identifiable functional changes. These changes have minimal effect on protein structure, being neither stabilizing nor destabilizing, are not found in regions of the proteins associated with known functions and tend to cluster in poorly constrained regions of proteins, specifically intrinsically disordered regions. We find no evidence that the difference between the current and previous outbreaks is due to evolutionary changes associated with transmission to humans. Instead, epidemiological factors are likely to be responsible for the unprecedented spread of EVD
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.
Arkansas Cotton Variety Test 2016
The primary goal of the Arkansas Cotton Variety Test is to provide unbiased data regarding the agronomic performance of cotton varieties and advanced breeding lines in the major cotton-growing areas of Arkansas
Arkansas Cotton Variety Test 2015
The primary goal of the Arkansas Cotton Variety Test is to provide unbiased data regarding the agronomic performance of cotton varieties and advanced breeding lines in the major cotton-growing areas of Arkansas. This information helps seed companies establish marketing strategies and assists producers in choosing varieties to plant. These annual evaluations will then facilitate the inclusion of new, improved genetic material in Arkansas cotton production
Adaptive HIV-1 evolutionary trajectories are constrained by protein stability
Despite the use of combination antiretroviral drugs for the treatment of HIV-1 infection, the emergence of drug resistance remains a problem. Resistance may be conferred either by a single mutation or a concerted set of mutations. The involvement of multiple mutations can arise due to interactions between sites in the amino acid sequence as a consequence of the need to maintain protein structure. To better understand the nature of such epistatic interactions, we reconstructed the ancestral sequences of HIV-1's Pol protein, and traced the evolutionary trajectories leading to mutations associated with drug resistance. Using contemporary and ancestral sequences we modelled the effects of mutations (i.e. amino acid replacements) on protein structure to understand the functional effects of residue changes. Although the majority of resistance-associated sequences tend to destabilise the protein structure, we find there is a general tendency for protein stability to decrease across HIV-1's evolutionary history. That a similar pattern is observed in the non-drug resistance lineages indicates that non-resistant mutations, for example, associated with escape from the immune response, also impacts on protein stability. Maintenance of optimal protein structure therefore represents a major constraining factor to the evolution of HIV-1
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