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Biomedical subjects

M W Haas

Publications and source records attributed to M W Haas.

3 recordsLinked to original sources

Virtually-augmented interfaces for tactical aircraft.

The term Fusion Interface is defined as a class of interface which integrally incorporates both virtual and non-virtual concepts and devices across the visual, auditory and haptic sensory modalities. A fusion interface is a multi-sensory virtually-augmented synthetic environment. A new facility has been developed within the Human Engineering Division of the Armstrong Laboratory dedicated to exploratory development of fusion-interface concepts. One of the virtual concepts to be investigated in the Fusion Interfaces for Tactical Environments facility (FITE) is the application of EEG and other physiological measures for virtual control of functions within the flight environment. FITE is a specialized flight simulator which allows efficient concept development through the use of rapid prototyping followed by direct experience of new fusion concepts. The FITE facility also supports evaluation of fusion concepts by operational fighter pilots in a high fidelity simulated air combat environment. The facility was utilized by a multi-disciplinary team composed of operational pilots, human-factors engineers, electronics engineers, computer scientists, and experimental psychologists to prototype and evaluate the first multi-sensory, virtually-augmented cockpit. The cockpit employed LCD-based head-down displays, a helmet-mounted display, three-dimensionally localized audio displays, and a haptic display. This paper will endeavor to describe the FITE facility architecture, some of the characteristics of the FITE virtual display and control devices, and the potential application of EEG and other physiological measures within the FITE facility.

Aerospace Medicine

Sequence requirements for activation of replication by the SV40 transcriptional promoter or enhancer elements.

Previous studies have demonstrated that the 21- or the 72-bp repeat transcriptional control elements enhance the efficiency of SV40 DNA replication in vivo, provided either of these repeats is located near the end of the core replication origin containing the 17-bp A + T-containing sequence. Using two sets of point mutants we have investigated the contributions of the various sequence motifs present in the 21- or the 72-bp repeats toward activation of replication. Regarding the contribution of the six GC motif components of the 21-bp repeats, we find that GC motif I, located closest to the core origin, is dispensable for activation of replication. A mutation in GC-I in fact causes an increase in replication efficiency. We also find that GC motifs I and II present in the nontandem copy of the 21-bp repeats are not sufficient to activate replication. Our present study indicates that a combination of three GC motifs such as II, III, and IV (including one of the two perfect, tandem copies of the 21-bp repeats) is important for activation of replication. Regarding the 72-bp repeat transcriptional enhancer region, we find mutations in a number of its individual motifs to have a negative consequence on replication, with mutations in the GT-I*/TC-II and Sph-II/octamer motifs exhibiting the most negative effects. Overall, we find that the replication activation effects of the 21- and the 72-bp repeats require the participation of multiple motifs present in them. Cellular factors binding to these motifs are expected to mediate their replication activation effects. For the most part, the motifs required for activation of replication are the same as those reported in earlier studies to be important for efficient early and late viral mRNA transcription.

Base Sequence

Peptidase activity in the inner membrane of Pseudomonas aeruginosa.

The location of peptidase activity within the cell envelope structure of Pseudomonas aeruginosa has been studied. Inner and outer membrane fractions were separated on the basis of buoyant density using two consecutive sucrose steps gradients and identified on the basis of known components. The inner membrane was shown to contain peptidase activity while the outer membrane contained none. These data support the hypothesis that P. aeruginosa transports intact peptides.

Cell Membrane