Analysis of navigation performance for the Earth Observing System (EOS) using the TDRSS Onboard Navigation System (TONS)

Use of the Tracking and Data Relay Satellite System (TDRSS) Onboard Navigation System (TONS) was proposed as an alternative to the Global Positioning System (GPS) for supporting the Earth Observing System (EOS) mission. The results are presented of EOS navigation performance evaluation with respect to TONS based orbit, time, and frequency determination (OD/TD/FD). Two TONS modes are considered: one uses scheduled TDRSS forward link service to derive one way Doppler tracking data for OD/FD support (TONS-I); the other uses an unscheduled navigation beacon service (proposed for Advanced TDRSS) to obtain pseudorange and Doppler data for OD/TD/FD support (TONS-II). Key objectives of the analysis were to evaluate nominal performance and potential sensitivities, such as suboptimal tracking geometry, tracking contact scheduling, and modeling parameter selection. OD/TD/FD performance predictions are presented based on covariance and simulation analyses. EOS navigation scenarios and the contributions of principal error sources impacting performance are also described. The results indicate that a TONS mode can be configured to meet current and proposed EOS position accuracy requirements of 100 and 50 m, respectively

Synthesis of Substituted Dimethylformamidyl Te(IV) & Se(IV) Chlorides

52-5

Reactions of Pyruvonitrile with Nb(V) & Ta(V) Alkoxides

406-40

On the Nature of Triphenylselenonium Chloride

123-12

Preparation & Characterization of Dimethylformamidyl Substituted Titanium( IV) Compounds

456-45

Stability of Coalescence Hidden variable Fractal Interpolation Surfaces

In the present paper, the stability of Coalescence Hidden variable Fractal Interpolation Surfaces(CHFIS) is established. The estimates on error in approximation of the data generating function by CHFIS are found when there is a perturbation in independent, dependent and hidden variables. It is proved that any small perturbation in any of the variables of generalized interpolation data results in only small perturbation of CHFIS. Our results are likely to be useful in investigations of texture of surfaces arising from the simulation of surfaces of rocks, sea surfaces, clouds and similar natural objects wherein the generating function depends on more than one variable

Ensemble-based docking: From hit discovery to metabolism and toxicity predictions

This paper describes and illustrates the use of ensemble-based docking, i.e., using a collection of protein structures in docking calculations for hit discovery, the exploration of biochemical pathways and toxicity prediction of drug candidates. We describe the computational engineering work necessary to enable large ensemble docking campaigns on supercomputers. We show examples where ensemble-based docking has significantly increased the number and the diversity of validated drug candidates. Finally, we illustrate how ensemble-based docking can be extended beyond hit discovery and toward providing a structural basis for the prediction of metabolism and off-target binding relevant to pre-clinical and clinical trials

A MULTIPURPOSE AND NOVEL CARRIER FOR DRUG DELIVERY AND TARGETING - VIROSOMES

There is presently passionate investigation bustle aimed at the improvement of new delivery systems for vaccines. The aspiration is to identify best possible methods for presenting target antigens to the immune system in a manner that will elicit immune responses appropriate for protection against, or treatment of, a specific disease. Virosomes are biocompatible, biodegradable, nontoxic, and non-autoimmunogenic, attempts have been made to use them as vaccines or adjuvant as well as delivery systems for drugs, nucleic acids, or genes for therapeutic purposes. Influenza virus is the most common virus of choice. There are at present numerous factors that are creating pressure to develop delivery systems for vaccines. First, in the existing regulatory milieu, there is a budding prerequisite to build up vaccines that are very well defined in molecular requisites. Unambiguous targeting and liberation as well as the display of antigens on the surface of Professional antigen-presenting cells (APCs) are key issues in the blueprint and improvement of new-generation vaccines intended at the initiation of both humoral and cell mediated immunity. Prophylactic vaccination in opposition to infectious diseases in general aims at the generation of humoral immune responses to prevent infection. However, mmunization with live vaccines bears the peril of causing ailment. For that reason, unconventional vaccine delivery systems are must to produce better immune response. Virosomal technology presents a fresh urbane delivery system to congregate these challenges. On the whole, virosomes guard pharmaceutically active substances from proteolytic dilapidation and low pH within endosomes, allowing their contents to linger intact when they get in touch with the cytoplasm. This is a foremost benefit of virosomal transporter systems over other drug-delivery vehicles, including liposomal and proteoliposomal carrier systems.Â