21 research outputs found
The artesian water of the Ruskin area of Hillsborough County, Florida: interim report
The purpose of the investigation is to make a detailed study of the
geology and ground water in the Ruskin area, especially as related to the
problem of salt-water encroachment. The major objectives of the program
includes:
(1) An inventory of wells to determine their number and distribution,
their depths and diameters, and other pertinent information.
(2) A study of artesian pressures.
(3) Analyses of water from selected wells to determine the location
and extent of any areas in which the artesian water is salty.
(4) A study of the surface and subsurface geology as related to the
occurrence and movement of ground water.
(5) An estimate of the quantity of ground water withdrawn.
(PDF contains 24 pages.
Interim report on the ground-water resources of Manatee County, Florida
A large part of western Manatee County is devoted to the growing of
winter vegetables and citrus fruits. As in most of peninsular Florida,
rainfall in the county during the growing season is not sufficient for crop
production and large quantites of artesian water are used for irrigation.
The large withdrawals of artesian water for irrigation result in a considerable
decline of the artesian head in the western part of the county. This seasonal
decline of the artesian head has become larger as the withdrawal of artesian
water has increased. The lowering of the fresh-water head in some coastal areas in the State
has resulted in an infiltration of sea water into the water-bearing formations.
The presence of salty water in the artesian aquifer in parts of the coastal area
of Manatee County indicates that sea water may also have entered the waterbearing
formations in this area as a result of the decline of artesian pressure
during the growing season. The purpose of the investigation is to make a detailed study of the geology
and ground-water resources of the county, primarily to determine whether
salt-water encroachment has occurred or is likely to occur in the coastal area. (PDF contains 38 pages.
Record of wells in the Ruskin area of Hillsborough County, FLorida
A detailed study of the geology and ground-water
resources of the Ruskin area (fig. 1) was made during the
period from 1950 to 1955, by the U. S. Geological Survey in
cooperation with the Florida Geological Survey and the Board
of County Commissioners of Hillsborough County. The
results of this study are given in a report by Harry M. Peek
entitled "The artesian water of the Ruskin area of Hillsborough
County, Florida" and published by the Florida Geological
Survey as Report of Investigations No. 21.
This report contains tables of well records that were
compiled from data collected during that investigation. The
well-numbering system used in the tables is based on latitude
and longitude. (PDF contains 88 pages.
Record of wells in Manatee County, Florida
A detailed study of the geology and ground-water
resources of Manatee County (fig. 1) was made during the
period from 1950 to 1955. This report contains a table of well records that was
compiled from data collected during that investigation. The
well-numbering system used in the table is based on latitude
and longitude. (PDF contains 204 pages.
The structure of the bacterial oxidoreductase enzyme DsbA in complex with a peptide reveals a basis for substrate specificity in the catalytic cycle of DsbA enzymes
Oxidative protein folding in Gram-negative bacteria results in the formation of disulfide bonds between pairs of cysteine residues. This is a multistep process in which the dithiol-disulfide oxidoreductase enzyme, DsbA, plays a central role. The structure of DsbA comprises an all helical domain of unknown function and a thioredoxin domain, where active site cysteines shuttle between an oxidized, substrate-bound, reduced form and a DsbB-bound form, where DsbB is a membrane protein that reoxidizes DsbA. Most DsbA enzymes interact with a wide variety of reduced substrates and show little specificity. However, a number of DsbA enzymes have now been identified that have narrow substrate repertoires and appear to interact specifically with a smaller number of substrates. The transient nature of the DsbA-substrate complex has hampered our understanding of the factors that govern the interaction of DsbA enzymes with their substrates. Here we report the crystal structure of a complex between Escherichia coli DsbA and a peptide with a sequence derived from a substrate. The binding site identified in the DsbA-peptide complex was distinct from that observed for DsbB in the DsbA-DsbB complex. The structure revealed details of the DsbA-peptide interaction and suggested a mechanism by which DsbA can simultaneously show broad specificity for substrates yet exhibit specificity for DsbB. This mode of binding was supported by solution nuclear magnetic resonance data as well as functional data, which demonstrated that the substrate specificity of DsbA could be modified via changes at the binding interface identified in the structure of the comple
The James Webb Space Telescope Mission
Twenty-six years ago a small committee report, building on earlier studies,
expounded a compelling and poetic vision for the future of astronomy, calling
for an infrared-optimized space telescope with an aperture of at least .
With the support of their governments in the US, Europe, and Canada, 20,000
people realized that vision as the James Webb Space Telescope. A
generation of astronomers will celebrate their accomplishments for the life of
the mission, potentially as long as 20 years, and beyond. This report and the
scientific discoveries that follow are extended thank-you notes to the 20,000
team members. The telescope is working perfectly, with much better image
quality than expected. In this and accompanying papers, we give a brief
history, describe the observatory, outline its objectives and current observing
program, and discuss the inventions and people who made it possible. We cite
detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space
Telescope Overview, 29 pages, 4 figure
The Science Performance of JWST as Characterized in Commissioning
This paper characterizes the actual science performance of the James Webb
Space Telescope (JWST), as determined from the six month commissioning period.
We summarize the performance of the spacecraft, telescope, science instruments,
and ground system, with an emphasis on differences from pre-launch
expectations. Commissioning has made clear that JWST is fully capable of
achieving the discoveries for which it was built. Moreover, almost across the
board, the science performance of JWST is better than expected; in most cases,
JWST will go deeper faster than expected. The telescope and instrument suite
have demonstrated the sensitivity, stability, image quality, and spectral range
that are necessary to transform our understanding of the cosmos through
observations spanning from near-earth asteroids to the most distant galaxies.Comment: 5th version as accepted to PASP; 31 pages, 18 figures;
https://iopscience.iop.org/article/10.1088/1538-3873/acb29