An inlet analysis for the NASA hypersonic research engine aerothermodynamic integration model

A theoretical analysis for the inlet of the NASA Hypersonic Research Engine (HRE) Aerothermodynamic Integration Model (AIM) has been undertaken by use of a method-of-characteristics computer program. The purpose of the analysis was to obtain pretest information on the full-scale HRE inlet in support of the experimental AIM program (completed May 1974). Mass-flow-ratio and additive-drag-coefficient schedules were obtained that well defined the range effected in the AIM tests. Mass-weighted average inlet total-pressure recovery, kinetic energy efficiency, and throat Mach numbers were obtained

HCV IRES manipulates the ribosome to promote the switch from translation initiation to elongation.

The internal ribosome entry site (IRES) of the hepatitis C virus (HCV) drives noncanonical initiation of protein synthesis necessary for viral replication. Functional studies of the HCV IRES have focused on 80S ribosome formation but have not explored its role after the 80S ribosome is poised at the start codon. Here, we report that mutations of an IRES domain that docks in the 40S subunit's decoding groove cause only a local perturbation in IRES structure and result in conformational changes in the IRES-rabbit 40S subunit complex. Functionally, the mutations decrease IRES activity by inhibiting the first ribosomal translocation event, and modeling results suggest that this effect occurs through an interaction with a single ribosomal protein. The ability of the HCV IRES to manipulate the ribosome provides insight into how the ribosome's structure and function can be altered by bound RNAs, including those derived from cellular invaders

DEPREDATION OF CATFISH BY DOUBLE-CRESTED CORMORANTS AT AQUACULTURE FACILITIES IN OKLAHOMA

Oklahoma has about 324 ha of surface water in catfish (Ictalurus spp.) production. The state also supports a large number of migrating and wintering piscivorous birds, particularly double-crested cormorants (Phalacrocorax auritus). To address concerns of aquaculture facility operators regarding loss of fish to cormorants, we asked 11 operators to conduct regular counts of piscivorous birds at each facility. These data were used to determine factors affecting cormorant density at facilities and to estimate amount of catfish lost to cormorant depredation. Cormorant density (birds/ha/day) was positively correlated with surface area of water in production at facilities \u3c10 ha (r = 0.621, P = 0.004) and negatively correlated with percentage of forested shoreline at each facility (r = -0.518, P = 0.016). Distance to nearest major reservoir or river was not significantly correlated with cormorant densities. To estimate depredation, we assumed a daily intake of 0.4 kg of fish per cormorant and used the average number of birds counted at participating facilities. Cormorants consumed an estimated 7,196 + 8,729 kg ( x + SE) of catfish, valued at $13,672-$36,195 (depending on size offish consumed), or about 3-7% of Oklahoma catfish sales in 1993

DEPREDATION OF CATFISH BY DOUBLE-CRESTED CORMORANTS AT AQUACULTURE FACILITIES IN OKLAHOMA

Oklahoma has about 324 ha of surface water in catfish (Ictalurus spp.) production. The state also supports a large number of migrating and wintering piscivorous birds, particularly double-crested cormorants (Phalacrocorax auritus). To address concerns of aquaculture facility operators regarding loss of fish to cormorants, we asked 11 operators to conduct regular counts of piscivorous birds at each facility. These data were used to determine factors affecting cormorant density at facilities and to estimate amount of catfish lost to cormorant depredation. Cormorant density (birds/ha/day) was positively correlated with surface area of water in production at facilities \u3c10 ha (r = 0.621, P = 0.004) and negatively correlated with percentage of forested shoreline at each facility (r = -0.518, P = 0.016). Distance to nearest major reservoir or river was not significantly correlated with cormorant densities. To estimate depredation, we assumed a daily intake of 0.4 kg of fish per cormorant and used the average number of birds counted at participating facilities. Cormorants consumed an estimated 7,196 + 8,729 kg ( x + SE) of catfish, valued at $13,672-$36,195 (depending on size offish consumed), or about 3-7% of Oklahoma catfish sales in 1993

Influence of leaf trichome type, and density on the host plant selection by the greenhouse whitefly, Trialeurodes vaporariorum (Hemiptera: Aleyrodidae)

Host selection by adult greenhouse whitefly Trialeurodes vaporariorum (Westwood) was assessed on two pelargonium plant cultivars, Pelargonium x domesticum (regal) and P. x hortorum (zonal) using Petri dish bioassay chambers in choice and no-choice tests. Plant characteristics which could influence the oviposition preference of the whitely i.e., type and density of trichomes on the abaxial leaf surface was determined. A strong host preference was observed for the regal compared to the zonal pelargonium by the adult whiteflies. In no-choice tests, adults laid a significantly higher number of eggs on regal than on zonal leaves both at 24 and 48 hours post-exposure, respectively. After exposure to the adult whitefly, the number of 42 eggs in choice tests were similar between cultivars at 24 hours, but were higher for regal at 48 and 72 hours. The total number of trichomes (sng: straight non-glandular + sg: straight glandular) per 0.50 cm2 44 was significantly less on regal (Mean ± SE sng + sg; 43.1 ± 1.5) than on zonal leaves (60.5 ± 1.2); however, the sng trichomes were significantly higher on the zonal (49.4 ± 0.96) than the regal leaves (28.6 ± 1.00). Also, the number of sg trichomes was slightly higher for the regal cultivar leaves compared to the zonal, being 14.4 ± 1.2 and 11.2 ± 0.5, respectively. Results suggest that the trichome density, type and the ability to express glandular exudates can affect adult whitefly Pelargonium cultivar preference and plays an important role in their host plant selection for oviposition

Note and Comment

The Law School--President Angell on Larger Preliminary Requirements--Faculty Changes--Enrollment; A Misleading Opinion as to the Defense of Non-Delivery of a Negotiable Instrument in an Action by a Holder in Due Course; Qualifications of Aliens for Naturalization; Fright Without Physical Impact but Resulting in Physical Injury; Noncompliance with Statutory Requirements as a Defense to Suits Brought by Foreign Corporations Where the Irregularity Has Been Cured Subsequently to the Institution of the Suit; In Absence of Proof What is the Presumption as to the Law of a Country not of Common Law Origi

Laser writing of coherent colour centres in diamond

Optically active point defects in crystals have gained widespread attention as photonic systems that can find use in quantum information technologies [1,2]. However challenges remain in the placing of individual defects at desired locations, an essential element of device fabrication. Here we report the controlled generation of single nitrogen-vacancy (NV) centres in diamond using laser writing [3]. The use of aberration correction in the writing optics allows precise positioning of vacancies within the diamond crystal, and subsequent annealing produces single NV centres with up to 45% success probability, within about 200 nm of the desired position. Selected NV centres fabricated by this method display stable, coherent optical transitions at cryogenic temperatures, a pre-requisite for the creation of distributed quantum networks of solid-state qubits. The results illustrate the potential of laser writing as a new tool for defect engineering in quantum technologies

Antarctic last interglacial isotope peak in response to sea ice retreat not ice-sheet collapse

Several studies have suggested that sea-level rise during the last interglacial implies retreat of the West Antarctic Ice Sheet (WAIS). The prevalent hypothesis is that the retreat coincided with the peak Antarctic temperature and stable water isotope values from 128,000 years ago (128 ka); very early in the last interglacial. Here, by analysing climate model simulations of last interglacial WAIS loss featuring water isotopes, we show instead that the isotopic response to WAIS loss is in opposition to the isotopic evidence at 128 ka. Instead, a reduction in winter sea ice area of 65±7% fully explains the 128 ka ice core evidence. Our finding of a marked retreat of the sea ice at 128 ka demonstrates the sensitivity of Antarctic sea ice extent to climate warming