Conservatism implications of shock test tailoring for multiple design environments

A method for analyzing shock conservation in test specifications that have been tailored to qualify a structure for multiple design environments is discussed. Shock test conservation is qualified for shock response spectra, shock intensity spectra and ranked peak acceleration data in terms of an Index of Conservation (IOC) and an Overtest Factor (OTF). The multi-environment conservation analysis addresses the issue of both absolute and average conservation. The method is demonstrated in a case where four laboratory tests have been specified to qualify a component which must survive seven different field environments. Final judgment of the tailored test specification is shown to require an understanding of the predominant failure modes of the test item

A study of the elements copper through uranium in Sirius A: Contributions from STIS and ground-based spectra

We determine abundances or upper limits for all of the 55 stable elements from copper to uranium for the A1 Vm star Sirius. The purpose of the study is to assemble the most complete picture of elemental abundances with the hope of revealing the chemical history of the brightest star in the sky, apart from the Sun. We also explore the relationship of this hot metallic-line (Am) star to its cooler congeners, as well as the hotter, weakly- or non-magnetic mercury-manganese (HgMn) stars. Our primary observational material consists of {\em Hubble Space Telescope} ($HST$) spectra taken with the Space Telescope Imaging Spectrograph (STIS) in the ASTRAL project. We have also used archival material from the %\citep/{ayr10}. $COPERNICUS$ satellite, and from the $HST$ Goddard High-Resolution Spectrograph (GHRS), as well as ground-based spectra from Furenlid, Westin, Kurucz, Wahlgren, and their coworkers, ESO spectra from the UVESPOP project, and NARVAL spectra retrieved from PolarBase. Our analysis has been primarily by spectral synthesis, and in this work we have had the great advantage of extensive atomic data unavailable to earlier workers. We find most abundances as well as upper limits range from 10 to 100 times above solar values. We see no indication of the huge abundance excesses of 1000 or more that occur among many chemically peculiar (CP) stars of the upper main sequence. The picture of Sirius as a hot Am star is reinforced.Comment: With 6 Figures and 4 Tables; accepted for publication in Ap

Cryopreservation of Sperm of Spotted Seatrout (Cynoscion nebulosus)

Cryopreservation of fish sperm has applications in preserving genetic resources from stocks of endangered fishes, replenishing fisheries, reducing the number of males needed in hatchery situations, and allowing repeated spawning of specific males. As part of a larger study on artificial breeding of sciaenid fishes, we developed procedures for collection, handling, refrigerated storage, and cryopreservation of spotted seatrout sperm. Hanks\u27 balanced salt solution (HBSS) was used as an extender for collection and storage of sperm. Sperm motility in relation to graded concentrations of HBSS was used to determine the osmolality at which sperm were activated. Based on these findings, HBSS was prepared at 201 mOsm/kg as an extender for sperm storage. To determine if ions present in HBSS were involved in sperm activation, separate activating solutions were prepared by the addition of NaCl, CaCl2, KCl, Na2HPO4, or MgSO4 to aliquots of a stock glucose solution (185 mOsm/kg). The chemicals were added at the concentration of each found in 1-x HBSS. Only the glucose solution containing 8 g/l NaCl(424 mOsm/kg) produced activation of sperm. We also evaluated four chemicals as cyroprotectants: methanol, glycerol, dimethyl sulfoxide (DMSO), and n,n-dimethyl acetamide. Two freezing rates were evaluated by placing samples at either of two heights within a nitrogen vapor shipping dewar. The highest post-thaw motilities were in 10% DMSO with an average retention of 60% of initial motility at the lower position in the dewar, and 37% at the upper position. A third freezing rate was produced using a computer-controlled freezer programmed for a rate of -45ºC/min, yielding a retention of initial motility of 31%. Our freezing and transport of cryopreserved sperm in shipping dewars demonstrate the utility of this procedure for field applications

Cryopreservation of Sperm of Spotted Seatrout (Cynoscion nebulosus)

Cryopreservation of fish sperm has applications in preserving genetic resources from stocks of endangered fishes, replenishing fisheries, reducing the number of males needed in hatchery situations, and allowing repeated spawning of specific males. As part of a larger study on artificial breeding of sciaenid fishes, we developed procedures for collection, handling, refrigerated storage, and cryopreservation of spotted seatrout sperm. Hanks\u27 balanced salt solution (HBSS) was used as an extender for collection and storage of sperm. Sperm motility in relation to graded concentrations of HBSS was used to determine the osmolality at which sperm were activated. Based on these findings, HBSS was prepared at 201 mOsm/kg as an extender for sperm storage. To determine if ions present in HBSS were involved in sperm activation, separate activating solutions were prepared by the addition of NaCl, CaCl2, KCl, Na2HPO4, or MgSO4 to aliquots of a stock glucose solution (185 mOsm/kg). The chemicals were added at the concentration of each found in 1-x HBSS. Only the glucose solution containing 8 g/l NaCl(424 mOsm/kg) produced activation of sperm. We also evaluated four chemicals as cyroprotectants: methanol, glycerol, dimethyl sulfoxide (DMSO), and n,n-dimethyl acetamide. Two freezing rates were evaluated by placing samples at either of two heights within a nitrogen vapor shipping dewar. The highest post-thaw motilities were in 10% DMSO with an average retention of 60% of initial motility at the lower position in the dewar, and 37% at the upper position. A third freezing rate was produced using a computer-controlled freezer programmed for a rate of -45ºC/min, yielding a retention of initial motility of 31%. Our freezing and transport of cryopreserved sperm in shipping dewars demonstrate the utility of this procedure for field applications

Natural History in Iowa: The Early Phases

Natural history in Iowa prior to the 20th Century can be conveniently arranged into 4 phases: Native American, before the Louisiana Purchase, between the Louisiana Purchase and about 1850, and after 1850. Native American natural history was extensive and had a distinctly spiritual character. Natural history was a component of European exploration up to the time of the Louisiana Purchase, but was not treated as a separate endeavor; the evidence from this period comes from the journals and diaries of early exploreres, fur traders and the like. Between the Louisiana Purchase and about 1850, natural history changed from its status as an adjunct to geographic exploration, for instance government sponsored expeditions along the rivers and Army excursions into the interior, to systematic research with natural history as the primary goal. During this period, descriptions of natural history moved from being parts of exploration narratives to reports on natural history itself. After 1850, natural history in Iowa encompassed organized, systematic efforts to record the geology, environment and biota of the state

Telomere formation on macronuclear chromosomes of Oxytricha trifallax and O. fallax: alternatively processed regions have multiple telomere addition sites

BACKGROUND: Ciliates employ massive chromatid breakage and de novo telomere formation during generation of the somatic macronucleus. Positions flanking the 81-MAC locus are reproducibly cut. But those flanking the Common Region are proposed to often escape cutting, generating three nested macronuclear chromosomes, two retaining "arms" still appended to the Common Region. Arm-distal positions must differ (in cis) from the Common Region flanks. RESULTS: The Common-Region-flanking positions also differ from the arm-distal positions in that they are "multi-TAS" regions: anchored PCR shows heterogeneous patterns of telomere addition sites, but arm-distal sites do not. The multi-TAS patterns are reproducible, but are sensitive to the sequence of the allele being processed. Thus, random degradation following chromatid cutting does not create this heterogeneity; these telomere addition sites also must be dictated by cis-acting sequences. CONCLUSIONS: Most ciliates show such micro-heterogeneity in the precise positions of telomere addition sites. Telomerase is believed to be tightly associated with, and act in concert with, the chromatid-cutting nuclease: heterogeneity must be the result of intervening erosion activity. Our "weak-sites" hypothesis explains the correlation between alternative chromatid cutting at the Common Region boundaries and their multi-TAS character: when the chromatid-breakage machine encounters either a weak binding site or a weak cut site at these regions, then telomerase dissociates prematurely, leaving the new end subject to erosion by an exonuclease, which pauses at cis-acting sequences; telomerase eventually heals these resected termini. Finally, we observe TAS positioning influenced by trans-allelic interactions, reminiscent of transvection

THE NEW FEDERALISM: HOW WOULD IT AFFECT MINNESOTA?

Community/Rural/Urban Development, Political Economy,

THE NEW FEDERALISM: WHAT IT MEANS FOR MINNESOTANS

Public Economics,

The Fish Fauna of Lake Maurepas, an Oligohaline Part of the Lake Pontchartrain Estuary

Lake Maurepas is a slightly saline body of water located at the upper end of the Lake Pontchartrain estuary. Of 67 fish species collected during 1983-84, 33 species (49%) are primarily freshwater, 6 (9%) are primarily marine, and 28 (42%) are estuarine or diadromous, commonly occurring in both freshwater and marine habitats. Major freshwater species (e.g. lctalurus furcatus, I. punctatus, and Aplodinotus grunniens) were present throughout the year, whereas most marine and estuarine species were seasonally present (e.g. Anchoa mitchilli, Brevoortia patronus, and Micropogonias undulatus), or were present during periods of higher (up to 2.5 o/oo) salinity (e.g. Cynoscion arenarius, Leiostomus xanthurus, and Pogonias cromis). Literature records indicate that larger percentages of marine species are present during years when salinities are higher (up to 8 o/oo)