LM rendezvous procedures - F mission, AS-505/CSM-106/LM-4 Final report

Rendezvous procedures for LM-4 and CSM for use in crew training and flight plannin

Productivity in American Whaling: The New Bedford Fleet in the Nineteenth Century

From the end of the War of 1812 until the Civil War the New Bedford whaling fleet grew spectacularly; thereafter it declined, equally spectacularly. By the end of the century New Bedford's day was over. During the 88 years of this period, the technical configuration of the fleet, the hunting grounds visited, and the types of whales pursued all changed dramatically, and more than once. The literature on whaling suggests that the collapse of the industry was due, in part, to declining productivity, occasioned by the disappearance of the whales (because of over-hunting) and the deterioration of the quality of labor. The shifts in the composition of the fleet are viewed, chiefly, as the result of efforts by whalemen to overcome their problems. In this paper, productivity data (superlative indexes), by voyage, are employed in multiple regression analysis to trace the relationships between the changes in the composition of the fleet and productivity. The propositions that declining labor quality and whale stocks had important consequences for productivity are subjected to test, while the impacts of technical changes on productivity are measured.

Risk Sharing, Crew Quality, Labor Shares and Wages in the Nineteenth Century American Whaling Industry

This paper examines 36.640 labor contracts signed between whalemen and the agents who organized 1,258 whaling voyages that departed from New Bedford, Massachusetts between January I. 1840 and December 31, 1858 and between January I and December 31, 1866. The contracts contain information on the whaleman's station (occupation) and on his lay (the fraction of output of the voyage that he was entitled to receive upon completion). The paper investigates the benefits associated with this unique contract. examines the occupational and spatial distribution of lays. and compares wages in whaling with those available in the merchant marine and those earned in shore based pursuits. It also attempts to assess the efficiency of this early labor market and to explore the relationship between the labor contract, crew quality. technical change. and productivity.

Fish culture in British East Africa

Volume: I

The Effects of Seasonality and Land Use on Microbe Populations in Three Ecological Areas

The Huron River watershed is comprised of three primary land uses: agricultural, natural, and urban. Land usage affects the biological and chemical conditions within the watershed, therefore affecting water quality. Recent studies have provided evidence that water quality can be assessed by examining the composition of the microbial communities found in biofilms. In this study we analyzed and compared samples collected from a natural site and urban site over the course of three seasons; fall (August), winter (December), and spring (April). Microbial diversity was determined by isolating, amplifying, and genotyping the 16S rRNA gene. The results show that microbial community structure varies with seasons, material composition, and site location

Draxin acts as a molecular rheostat of canonical Wnt signaling to control cranial neural crest EMT

Neural crest cells undergo a spatiotemporally regulated epithelial-to-mesenchymal transition (EMT) that proceeds head to tailward to exit from the neural tube. In this study, we show that the secreted molecule Draxin is expressed in a transient rostrocaudal wave that mirrors this emigration pattern, initiating after neural crest specification and being down-regulated just before delamination. Functional experiments reveal that Draxin regulates the timing of cranial neural crest EMT by transiently inhibiting canonical Wnt signaling. Ectopic maintenance of Draxin in the cranial neural tube blocks full EMT; while cells delaminate, they fail to become mesenchymal and migratory. Loss of Draxin results in premature delamination but also in failure to mesenchymalize. These results suggest that a pulse of intermediate Wnt signaling triggers EMT and is necessary for its completion. Taken together, these data show that transient secreted Draxin mediates proper levels of canonical Wnt signaling required to regulate the precise timing of initiation and completion of cranial neural crest EMT

Draxin alters laminin organization during basement membrane remodeling to control cranial neural crest EMT

Premigratory neural crest cells arise within the dorsal neural tube and subsequently undergo an epithelial-to-mesenchymal transition (EMT) to leave the neuroepithelium and initiate migration. Draxin is a Wnt modulator that has been shown to control the timing of cranial neural crest EMT. Here we show that this process is accompanied by three stages of remodeling of the basement membrane protein laminin, from regression to expansion and channel formation. Loss of Draxin results in blocking laminin remodeling at the regression stage, whereas ectopic maintenance of Draxin blocks remodeling at the expansion stage. The latter effect is rescued by addition of Snail2, previously shown to be downstream of Draxin. Our results demonstrate an essential function for the Wnt modulator Draxin in regulating basement membrane remodeling during cranial neural crest EMT

Did you Pack your Keys? Smart Objects And Forgetfulness

Engineering and Physical Sciences Research Council (EPSRC) as part of the Centre for Doctoral Training in Media and Arts Technology at Queen Mary University of London