38,028 research outputs found

    Embryos as Patients? Medical Provider Duties in the Age of CRISPR/Cas9

    Get PDF
    The CRISPR/Cas9 genome engineering platform is the first method of gene editing that could potentially be used to treat genetic disorders in human embryos. No past therapies, genetic or otherwise, have been intended or used to treat disorders in existent embryos. Past procedures performed on embryos have exclusively involved creation and implantation (e.g., in-vitro fertilization) or screening and selection of already-healthy embryos (e.g., preimplantation genetic diagnosis). A CRISPR/Cas9 treatment would evade medical malpractice law due to the early stage of the intervention and the fact that it is not a treatment for the mother. In most jurisdictions, medical professionals owe no duty to pre-viable fetuses or embryos as such, but will be held liable for negligent treatment of the mother if the treatment causes injury to a born-alive child. This issue brief discusses the science of CRISPR/Cas9, the background legal status of human embryos, and the case for considering genetically engineered embryos as patients for purposes of medical malpractice law

    The right wing of the LEFT airplane

    Get PDF
    The NASA Leading-Edge Flight Test (LEFT) program addressed the environmental issues which were potential problems in the application of Laminar Flow Control (LFC) to transport aircraft. These included contamination of the LFC surface due to dirt, rain, insect remains, snow, and ice, in the critical leading-edge region. Douglas Aircraft Company designed and built a test article which was mounted on the right wing of the C-140 JetStar aircraft. The test article featured a retractable leading-edge high-lift shield for contamination protection and suction through perforations on the upper surface for LFC. Following a period of developmental flight testing, the aircraft entered simulated airline service, which included exposure to airborne insects, heavy rain, snow, and icing conditions both in the air and on the ground. During the roughly 3 years of flight testing, the test article has consistently demonstrated laminar flow in cruising flight. The experience with the LEFT experiment was summarized with emphasis on significant test findings. The following items were discussed: test article design and features; suction distribution; instrumentation and transition point reckoning; problems and fixes; system performance and maintenance requirements

    Derivation of near-optimal pump schedules for water distribution by simulated annealing

    Get PDF
    The scheduling of pumps for clean water distribution is a partially discrete non-linear problem with many variables. The scheduling method described in this paper typically produces costs within 1% of a linear program-based solution, and can incorporate realistic non-linear costs that may be hard to incorporate in linear programming formulations. These costs include pump switching and maximum demand charges. A simplified model is derived from a standard hydraulic simulator. An initial schedule is produced by a descent method. Two-stage simulated annealing then produces solutions in a few minutes. Iterative recalibration ensures that the solution agrees closely with the results from a full hydraulic simulation

    Commodity Supply and Extraterritorial Patent Infringement in Life Technologies V. Promega

    Get PDF
    American patent law grants inventors the exclusive right, within U.S. territory, to make, sell, use, and import their patented inventions. In response to attempts to circumvent the right by making the components of an invention within the U.S. and exporting them for assembly abroad, Congress passed 35 U.S.C. § 271(f), prohibiting “suppl[ying] . . . from the United States all or a substantial portion of the components of a patented invention . . . to actively induce the combination of such components outside of the United States . . . .” Petitioner Life Technologies supplied one commodity component of a patented five-component genetic testing kit from the U.S. The Federal Circuit held them liable under § 271(f), upholding a jury verdict and allowing that one component could be a “substantial portion of the components.” The Supreme Court reversed, reading § 271(f) not to reach the supply of a single component. This ruling will help to preserve suppliers’ confidence in their freedom to ship commodities overseas without being liable for infringement

    Incorporation of cytochrome oxidase into cardiolipin bilayers and induction of nonlamellar phases.

    Get PDF
    Cytochrome oxidase from beef heart has been lipid-substituted with beef heart cardiolipin. The lipid phase behavior and protein aggregation state of the reconstituted complexes have been studied with 31P NMR, freeze-fracture electron microscopy, and saturation-transfer ESR of the spin-labeled protein. In the absence of salt, the lipid has a lamellar arrangement, and the protein is integrated and uniformly distributed in the membrane vesicles and undergoes rapid rotational diffusion. The presence of the protein stabilizes the cardiolipin lamellar phase against salt-induced transitions to the inverted hexagonal phase. The threshold salt concentration becomes higher and the extent of conversion becomes lower with decreasing lipid:protein ratio. In high salt, lamellar-phase lipid with integrated protein coexists with hexagonal-phase lipid free of protein, and the rotational diffusion of the protein is drastically reduced as a result of the high packing density

    Tone-burst technique measures high-intensity sound absorption

    Get PDF
    Tone-burst technique, in which narrow-bandwidth, short-duration sonic pulse is propagated down a standing-wave tube, measures sound absorbing capacity of materials used in jet engine noise abatement. Technique eliminates effects of tube losses and yields normal-incidence absorption coefficient of specimen

    Phase field theory of interfaces and crystal nucleation in a eutectic system of fcc structure: I. Transitions in the one-phase liquid region

    Get PDF
    The published version of this Article can be accessed from the link below - Copyright @ 2007 American Institute of PhysicsThe phase field theory (PFT) has been applied to predict equilibrium interfacial properties and nucleation barrier in the binary eutectic system Ag-Cu using double well and interpolation functions deduced from a Ginzburg-Landau expansion that considers fcc (face centered cubic) crystal symmetries. The temperature and composition dependent free energies of the liquid and solid phases are taken from CALculation of PHAse Diagrams-type calculations. The model parameters of PFT are fixed so as to recover an interface thickness of approximately 1 nm from molecular dynamics simulations and the interfacial free energies from the experimental dihedral angles available for the pure components. A nontrivial temperature and composition dependence for the equilibrium interfacial free energy is observed. Mapping the possible nucleation pathways, we find that the Ag and Cu rich critical fluctuations compete against each other in the neighborhood of the eutectic composition. The Tolman length is positive and shows a maximum as a function of undercooling. The PFT predictions for the critical undercooling are found to be consistent with experimental results. These results support the view that heterogeneous nucleation took place in the undercooling experiments available at present. We also present calculations using the classical droplet model classical nucleation theory (CNT) and a phenomenological diffuse interface theory (DIT). While the predictions of the CNT with a purely entropic interfacial free energy underestimate the critical undercooling, the DIT results appear to be in a reasonable agreement with the PFT predictions.This work has been supported by the Hungarian Academy of Sciences under Contract No. OTKA-K-62588 and by the ESA PECS Contract Nos. 98005, 98021, and 98043

    Ethics – research, engineering, design… they’re all the same aren’t they?

    Get PDF
    This paper considers how and to what extent product design ethics is understood by professionals in design practice and undergraduate students of product and engineering design and how, if at all, design ethics differ from engineering and/or research ethics. This paper reports on a study carried out at Bournemouth University with undergraduate students of Engineering Design and Product Design and with design professionals via the Institution of Engineering Designers. As part of their final year project work all undergraduate students at Bournemouth University are required to comply with the Bournemouth University Research Ethics Code of Practice [9] which means that students are aware of ethical principles in general and the study explored the extent to which students understand them in relation to design. The study also used the ‘LinkedIn’ discussion forum to get the perspective of design practitioners. The paper concludes that designers do seem to share a broadly common understanding of design ethics and that the main difference with design ethics is in the scope, complexity and the human interface. A definition of product design ethics is presented and the essence of a Statement of Principles for product design ethics proposed
    corecore