State of the art survey of technologies applicable to NASA's aeronautics, avionics and controls program

The state of the art survey (SOAS) covers six technology areas including flightpath management, aircraft control system, crew station technology, interface & integration technology, military technology, and fundamental technology. The SOAS included contributions from over 70 individuals in industry, government, and the universities

Autonomous wheelchair with a smart driving mode and a Wi-Fi positioning system

Wheelchairs are an important aid that enhances the mobility of people with several types of disabilities. Therefore, there has been considerable research and development on wheelchairs to meet the needs of the disabled. Since the early manual wheelchairs to their more recent electric powered counterparts, advancements have focused on improving autonomy in mobility. Other developments, such as Internet advancements, have developed the concept of the Internet of Things (IoT). This is a promising area that has been studied to enhance the independent operation of the electrical wheelchairs by enabling autonomous navigation and obstacle avoidance. This dissertation describes shortly the design of an autonomous wheelchair of the IPL/IT (Instituto Politécnico de Leiria/Instituto de Telecomunicações) with smart driving features for persons with visual impairments. The objective is to improve the prototype of an intelligent wheelchair. The first prototype of the wheelchair was built to control it by voice, ocular movements, and GPS (Global Positioning System). Furthermore, the IPL/IT wheelchair acquired a remote control feature which could prove useful for persons with low levels of visual impairment. This tele-assistance mode will be helpful to the family of the wheelchair user or, simply, to a health care assistant. Indoor and outdoor positioning systems, with printed directional Wi-Fi antennas, have been deployed to enable a precise location of our wheelchair. The underlying framework for the wheelchair system is the IPL/IT low cost autonomous wheelchair prototype that is based on IoT technology for improved affordability

Advances in Time-Domain Electromagnetic Simulation Capabilities Through the Use of Overset Grids and Massively Parallel Computing

A new methodology is presented for conducting numerical simulations of electromagnetic scattering and wave propagation phenomena. Technologies from several scientific disciplines, including computational fluid dynamics, computational electromagnetics, and parallel computing, are uniquely combined to form a simulation capability that is both versatile and practical. In the process of creating this capability, work is accomplished to conduct the first study designed to quantify the effects of domain decomposition on the performance of a class of explicit hyperbolic partial differential equations solvers; to develop a new method of partitioning computational domains comprised of overset grids; and to provide the first detailed assessment of the applicability of overset grids to the field of computational electromagnetics. Furthermore, the first Finite Volume Time Domain (FVTD) algorithm capable of utilizing overset grids on massively parallel computing platforms is developed and implemented. Results are presented for a number of scattering and wave propagation simulations conducted using this algorithm, including two spheres in close proximity and a finned missile

NASA Tech Briefs, September 1990

Topics covered include: New Product Ideas; NASA TU Services; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences

Characterization of a novel cell wall binding domain of the fratricin CbpD from Streptococcus dysgalactiae

The Streptococcus genus contains a large variety of species across seven subgroups. The lesser-known Streptococcus dysgalactiae of the pyogenic group is both a human and an animal pathogen and is subsequently divided into two subspecies: S. dysgalactiae subsp. equisimilis (SDSE) and S. dysgalactiae subsp. dysgalactiae (SDSD), respectively. The SDSD has been the main focus of the present work, where it has great significance in causing bovine mastitis in cows and septic arthritis in lambs. This has caused various problems in the dairy industry and livestock production, where antibiotics for treatment are necessary. The relatively recent observation of zoonotic diseases in humans, and reports of penicillin-resistant SDSE isolates, have made it a vital pathogen to focus our studies on. In addition, considering S. dysgalactiae has a complete set of competence genes and a fratricin for competence-induced cell lysis, natural competence for genetic transformation might be an important horizontal gene transfer mechanism to acquire genes for adaptability and evolution. The following work has therefore been an in-depth investigation of the S. dysgalactiae fratricin protein and specifically on its lesser characterized conserved domain. It has previously been shown by fluorescence microscopy that the protein binds to the septal region (the division zone) of targeted cells. Here, it was seen that by fusing a superfolder green fluorescent protein onto the conserved domain, it still retained its septal binding abilities, demonstrating that this domain is responsible for directing the fratricin to septum. A conserved leucine-alanine-glycine-glycine motif and conserved amino acids glutamine and tryptophan were identified by a multiple sequence alignment, individually point-mutated by overlap-extension polymerase chain reaction and visualized by a fluorescence microscope to determine if the septal binding patterns changed. Unevenly binding across the entire target cells was observed, indicating that these highly conserved amino acids are important for the conserved domain’s ability for septal recognition. Several protocols for removal of teichoic acids on isolated S. dysgalactiae sacculi were also performed, where using trichloroacetic acid for two weeks on the sacculi was ultimately chosen. Sacculi deficient in teichoic acids showed no septal recognition by the fratricin, revealing that specific molecular moieties on these polymers are necessary to guide the protein towards the division zone. Competent-induced and non-induced S. dysgalactiae cells were also exposed to the fratricin in a lytic assay, revealing that the induced cells had acquired immunity.Slekten Streptococcus inneholder et stort utvalg av arter spredt over syv undergrupper. Den mindre kjente Streptococcus dysgalactiae fra pyogenic-gruppen er både et menneske- og et dyrepatogen, og er dermed delt inn i to underarter: S. dysgalactiae subsp. equisimilis (SDSE) og S. dysgalactiae subsp. dysgalactiae (SDSD), hhv. SDSD har vært i hovedfokus i denne oppgaven, hvor den har stor betydning i å forårsake bovin mastitt i kyr og septisk artritt hos lam. Dette har skapt en rekke problemer i meieriindustrien og husdyrproduksjonen, hvor antibiotika må brukes for behandling. Det har også nylig blitt observert zoonotisk sykdom i mennesker, og rapporteringer om penicillinresistente SDSE-isolater, noe som gjør S. dysgalactiae et viktig patogen å studere. I tillegg, ettersom arten har et komplett sett med kompetansegener og et fratrisin for kompetanseindusert celle lysis, kan naturlig kompetanse for genetisk transformasjon være en viktig horisontal genoverføringsmekanisme for å tilegne seg gener for tilpasning og evolusjon. Følgende arbeid har derfor vært en grundig undersøkelse av fratrisin-proteinet og dets knapt karakteriserte konserverte domene. Det har tidligere blitt vist ved fluorescensmikroskop at proteinet binder til den septale regionen av målrettet celler. I denne oppgaven ble det sett, ved fusjonering av et superfoldende grønt fluorescerende protein på det konserverte domenet, at det likevel beholdt proteinets septale bindingsevne. Dette demonstrerer at domenet er ansvarlig for å dirigere proteinet til septum. Det konserverte leucin-alanin-glysin-glysin motivet og aminosyrene glutamin og tryptofan ble også identifisert ved multippelsekvensanalyse, individuelt punktmutert ved overlapp-polymerase kjedereaksjon og visualisert under fluorescensmikroskopet for å se om septalbindingsmønsteret endret seg. Ujevn binding over hele målcellen ble observert, noe som indikerer at disse høyt konserverte aminosyrene er viktig for det konserverte domenets evne til septal gjenkjennelse. Det ble også utført flere ulike protokoller for å fjerne tekoinsyrene på isolert S. dysgalactiae sacculi, hvor bruk av trikloreddiksyre i to uker på sacculi ble valgt til slutt. Sacculi uten tekoinsyrer viste ingen septal gjenkjennelse av fratrisinet, og det ble konkludert at disse polymerne er nødvendig for å lede proteinet mot delingssonen. Kompetent-induserte og ikke-induserte S. dysgalactiae celler ble også eksponert for fratrisinet i en lytisk analyse, som avslørte at de induserte cellene hadde oppnådd immunitet.M-BIOTE