Design and Performance of Lift-Offset Rotorcraft for Short-Haul Missions

The design and performance of compound helicopters utilizing lift-offset rotors are examined, in the context of short-haul, medium-size civil and military missions. The analysis tools used are the comprehensive analysis CAMRAD II and the sizing code NDARC. Following correlation of the comprehensive analysis with existing lift-offset aircraft flight test data, the rotor performance model for the sizing code was developed, and an initial estimate was made of the rotor size and key hover and cruise flight conditions. The rotor planform and twist were optimized for those conditions, and the sizing code rotor performance model updated. Two models for estimating the blade and hub weight of lift-offset rotors are discussed. The civil and military missions are described, along with the aircraft design assumptions. The aircraft are sized for 30 passengers or 6600 lb payload, with a range of 300 nm. Civil and military aircraft designs are described for each of the rotor weight models. Disk loading and blade loading were varied to optimize the designs, based on gross weight and fuel burn. The influence of technology is shown, in terms of rotor hub drag and rotor weight

Food Intake of the Largemouth Bass

During 18 months of electrofishing a sample of 991 adult largemouth bass (Micropterus salmoides) was taken from Crab Orchard Lake. The stomach contents were removed in the field with a gastroscope. Gizzard shad (Dorosoma cepedianum) constituted the principal forage fish. Approximately 50% of the bass collected had empty stomachs. As the size of bass increased, the food intake as a percent of body weight decreased. Ninety percent of the bass stomachs contained one food item. When more than one food item was found, they were usually in the same stage of digestion. It is suggested that the high percent of empty stomachs was related to hunting success, or that the onset of the feeding stimulus in association with rate of digestion might result in a periodicity of feeding that involves a high percent of empty stomachs. A higher relative intake of food by small bass was postulated to be a result of the bass\u27s typically consuming only one fish. Inasmuch as the forage fish were relatively uniform in size, one fish constituted a large meal for a small bass but not for a large bass

Impact of Using Drones in Emergency Medicine: What Does the Future Hold?

The use of unmanned aerial vehicles or drones has expanded in the last decade, as their technology has become more sophisticated, and costs have decreased. They are now used routinely in farming, environmental surveillance, public safety, commercial product delivery, recreation, and other applications. Health-related applications are only recently becoming more widely explored and accepted. The use of drone technology in emergency medicine is especially promising given the need for a rapid response to enhance patient outcomes. The purpose of this paper is to describe some of the main current and expanding applications of drone technology in emergency medicine and to describe challenges and future opportunities. Current applications being studied include delivery of defibrillators in response to out-of-hospital cardiac arrest, blood and blood products in response to trauma, and rescue medications. Drones are also being studied and actively used in emergency response to search and rescue operations as well as disaster and mass casualty events. Current challenges to expanding their use in emergency medicine and emergency medical system (EMS) include regulation, safety, flying conditions, concerns about privacy, consent, and confidentiality, and details surrounding the development, operation, and maintenance of a medical drone network. Future research is needed to better understand end user perceptions and acceptance. Continued technical advances are needed to increase payload capacities, increase flying distances, and integrate drone networks into existing 9-1-1 and EMS systems. Drones are a promising technology for improving patient survival, outcomes, and quality of life, particularly for those in areas that are remote or that lack funds or infrastructure. Their cost savings compared with ground transportation alone, speed, and convenience make them particularly applicable in the field of emergency medicine. Research to date suggests that use of drones in emergency medicine is feasible, will be accepted by the public, is cost-effective, and has broad application

Virtual Histology of Transgenic Mouse Embryos for High-Throughput Phenotyping

A bold new effort to disrupt every gene in the mouse genome necessitates systematic, interdisciplinary approaches to analyzing patterning defects in the mouse embryo. We present a novel, rapid, and inexpensive method for obtaining high-resolution virtual histology for phenotypic assessment of mouse embryos. Using osmium tetroxide to differentially stain tissues followed by volumetric X-ray computed tomography to image whole embryos, isometric resolutions of 27 μm or 8 μm were achieved with scan times of 2 h or 12 h, respectively, using mid-gestation E9.5–E12.5 embryos. The datasets generated by this method are immediately amenable to state-of-the-art computational methods of organ patterning analysis. This technique to assess embryo anatomy represents a significant improvement in resolution, time, and expense for the quantitative, three-dimensional analysis of developmental patterning defects attributed to genetically engineered mutations and chemically induced embryotoxicity

Murine cytomegalovirus protein pM79 is a key regulator for viral late transcription

Herpesvirus genes are temporally expressed during permissive infections, but how their expression is regulated at late times is poorly understood. Previous studies indicate that the human cytomegalovirus (CMV) gene, UL79, is required for late gene expression. However, the mechanism remains to be fully elucidated, and UL79 homologues in other CMVs have not been studied. Here, we characterized the role of the conserved murine CMV (MCMV) gene M79. We showed that M79 encoded a protein (pM79) which was expressed with early-late kinetics and localized to nuclear viral replication compartments. M79 transcription was significantly decreased in the absence of viral DNA synthesis but markedly stimulated by pM79. To investigate its role, we created the recombinant virus SMin79, in which pM79 expression was disrupted. While marker-rescued virus grew efficiently in fibroblasts, SMin79 failed to produce infectious progeny but was rescued by pM79 expression in trans. During SMin79 infection, representative viral immediate-early and early gene products as well as viral DNA accumulated sufficiently. Formation of viral replication compartments also appeared normal. Pulsed-field gel electrophoresis analysis indicated that the overall structure of replicating viral DNA was indistinguishable between wild-type and SMin79 infection. Viral tiled array and quantitative PCR analysis revealed that many late transcripts sensitive to a viral DNA synthesis inhibitor (phosphonoacetic acid) were markedly reduced by pM79 mutation. This study indicates that cytomegaloviruses use a conserved mechanism to promote transcription at late stages of infection and that pM79 is a critical regulator for at least a subset of viral DNA synthesis-dependent transcripts

Full-Shell X-Ray Optics Development at NASA Marshall Space Flight Center

NASAs Marshall Space Flight Center (MSFC) maintains an active research program toward the development of high-resolution, lightweight, grazing-incidence x-ray optics to serve the needs of future x-ray astronomy missions such as Lynx. MSFC development efforts include both direct fabrication (diamond turning and deterministic computer-controlled polishing) of mirror shells and replication of mirror shells (from figured, polished mandrels). Both techniques produce full-circumference monolithic (primary + secondary) shells that share the advantages of inherent stability, ease of assembly, and low production cost. However, to achieve high-angular resolution, MSFC is exploring significant technology advances needed to control sources of figure error including fabrication- and coating-induced stresses and mounting-induced distortions