An Optimal Control Formulation for Inviscid Incompressible Ideal Fluid Flow

In this paper we consider the Hamiltonian formulation of the equations of incompressible ideal fluid flow from the point of view of optimal control theory. The equations are compared to the finite symmetric rigid body equations analyzed earlier by the authors. We discuss various aspects of the Hamiltonian structure of the Euler equations and show in particular that the optimal control approach leads to a standard formulation of the Euler equations -- the so-called impulse equations in their Lagrangian form. We discuss various other aspects of the Euler equations from a pedagogical point of view. We show that the Hamiltonian in the maximum principle is given by the pairing of the Eulerian impulse density with the velocity. We provide a comparative discussion of the flow equations in their Eulerian and Lagrangian form and describe how these forms occur naturally in the context of optimal control. We demonstrate that the extremal equations corresponding to the optimal control problem for the flow have a natural canonical symplectic structure.Comment: 6 pages, no figures. To appear in Proceedings of the 39th IEEEE Conference on Decision and Contro

Eimeria tenella protein trafficking: differential regulation of secretion versus surface tethering during the life cycle

Eimeria spp. are intracellular parasites that have a major impact on poultry. Effective live vaccines are available and the development of reverse genetic technologies has raised the prospect of using Eimeria spp. as recombinant vectors to express additional immunoprotective antigens. To study the ability of Eimeria to secrete foreign antigens or display them on the surface of the sporozoite, transiently transfected populations of E. tenella expressing the fluorescent protein mCherry, linked to endogenous signal peptide (SP) and glycophosphatidylinositol-anchor (GPI) sequences, were examined. The SP from microneme protein EtMIC2 (SP2) allowed efficient trafficking of mCherry to cytoplasmic vesicles and following the C-terminal addition of a GPI-anchor (from surface antigen EtSAG1) mCherry was expressed on the sporozoite surface. In stable transgenic populations, mCherry fused to SP2 was secreted into the sporocyst cavity of the oocysts and after excystation, secretion was detected in culture supernatants but not into the parasitophorous vacuole after invasion. When the GPI was incorporated, mCherry was observed on the sporozites surface and in the supernatant of invading sporozoites. The proven secretion and surface exposure of mCherry suggests that antigen fusions with SP2 and GPI of EtSAG1 may be promising candidates to examine induction of protective immunity against heterologous pathogens

Analysis of the Venoms of Four Subspecies of the Western Rattlesnake (Crotalus oreganus)

Recently, the benefits venom can have in the discovery and development of different medications to assist in treating a variety of diverse human diseases have been areas of research. In order to develop a better understanding of how to evaluate venoms for potential use as therapeutics, one needs to look at the fundamental composition of venom samples. This project aims at discovering and analyzing the basic components from the venom of four different subspecies of the Western Rattlesnake. Venom samples collected will be subjected to size exclusion chromatography to separate proteins of different sizes. After fractionation of venoms, the following assays are conducted on individual fractions to locate specific activities of enzymatic venom proteins: metalloproteinase activity, kallikrein-like and thrombin-like serine proteinase activities, phospholipase A2 activity, phosphodiesterase activity and L-amino acid oxidase activity. These tests will compare the basic biochemistry of the samples of venoms from the different subspecies to help expand knowledge on chemistry differences between closely related subspecies of rattlesnakes. Snakes use their venoms primarily to obtain food, and results will allow for further evaluation of how their differing venom compositions relate to specific aspects of their ecology, such as use of divergent habitats, potential risks of different predators, effects on various prey species utilized, as well as revealing those components that have remained static and are shared among all subspecies analyzed. Because envenomation symptoms will vary due to venom composition, these results will also help inform what medical sequelae should be expected from particular populations of rattlesnakes

Operating Efficiently Post-Bilski by Ordering Patent Doctrine Decision-Making

Now that the Supreme Court has decided Bilski v. Kappos, there is an enormous amount of speculation about the case’s impact on patent applicants, litigants, and other participants in the patent system. Most of the commentary is concerned with the holding in Bilski, how this holding will be applied by courts and the Patent Office, and ultimately, the effect of the holding on inventors, and those who hold and seek patents

Dynamic Shear Modulus and Damping Ratio Predicted by a Unified 3-D Critical State Bounding Surface Plasticity Model

A unified 3-d critical state bounding surface plasticity model (gUTS) has been developed which is able to provide realistic simulations of the behavior of clays, silts and sands both in drained and undrained conditions over a wide range of monotonic and complex cyclic paths. A strong feature of this model is its ability to treat loose and dense states of the same material with a single set of material constants. The link between the two states is made by introducing an apparent normal consolidation line for sands and adopting a volumetric plastic strain hardening/softening model (similar to the critical state models for clays). This and other features enable the model to degenerate to simpler forms including the classic modified Cam-Clay formulation. To date, simulations have concentrated on the medium to high strain range (10-3 to 10-1). To address a wider strain range, this paper reports on a new series of simulations for sand in the range 10-6 to 10-

On the geometry of Riemannian cubic polynomials

AbstractWe continue the work of Crouch and Silva Leite on the geometry of cubic polynomials on Riemannian manifolds. In particular, we generalize the theory of Jacobi fields and conjugate points and present necessary and sufficient optimality condition

Viral proteins expressed in the protozoan parasite Eimeria tenella are detected by the chicken immune system

BACKGROUND: Eimeria species are parasitic protozoa that cause coccidiosis, an intestinal disease commonly characterised by malabsorption, diarrhoea and haemorrhage that is particularly important in chickens. Vaccination against chicken coccidiosis is effective using wild-type or attenuated live parasite lines. The development of protocols to express foreign proteins in Eimeria species has opened up the possibility of using Eimeria live vaccines to deliver heterologous antigens and function as multivalent vaccine vectors that could protect chickens against a range of pathogens. RESULTS: In this study, genetic complementation was used to express immunoprotective virus antigens in Eimeria tenella. Infectious bursal disease virus (IBDV) causes Gumboro, an immunosuppressive disease that affects productivity and can interfere with the efficacy of poultry vaccination programmes. Infectious laryngotracheitis virus (ILTV) causes a highly transmissible respiratory disease for which strong cellular immunity and antibody responses are required for effective vaccination. Genes encoding the VP2 protein from a very virulent strain of IBDV (vvVP2) and glycoprotein I from ILTV (gI) were cloned downstream of 5’Et-Actin or 5’Et-TIF promoter regions in plasmids that also contained a mCitrine fluorescent reporter cassette under control of the 5’Et-MIC1 promoter. The plasmids were introduced by nucleofection into E. tenella sporozoites, which were then used to infect chickens. Progeny oocysts were sorted by FACS and passaged several times in vivo until the proportion of fluorescent parasites in each transgenic population reached ~20 % and the number of transgene copies per parasite genome decreased to < 10. All populations were found to transcribe and express the transgene and induced the generation of low titre, transgene-specific antibodies when used to immunise chickens. CONCLUSIONS: E. tenella can express antigens of other poultry pathogens that are successfully recognised by the chicken immune system. Nonetheless, further work has to be done in order to improve the levels of expression for its future use as a multivalent vaccine vector. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13071-016-1756-2) contains supplementary material, which is available to authorized users

Classroom Demonstrations: Learning Tools Or Entertainment?

We compared student learning from different modes of presenting classroom demonstrations to determine how much students learn from traditionally presented demonstrations, and whether learning can be enhanced by simply changing the mode of presentation to increase student engagement. We find that students who passively observe demonstrations understand the underlying concepts no better than students who do not see the demonstration at all, in agreement with previous studies. Learning is enhanced, however, by increasing student engagement; students who predict the demonstration outcome before seeing it, however, display significantly greater understanding