6,252 research outputs found
Development of the L-1011 four-dimensional flight management system
The development of 4-D guidance and control algorithms for the L-1011 Flight Management System is described. Four-D Flight Management is a concept by which an aircraft's flight is optimized along the 3-D path within the constraints of today's ATC environment, while its arrival time is controlled to fit into the air traffic flow without incurring or causing delays. The methods developed herein were designed to be compatible with the time-based en route metering techniques that were recently developed by the Dallas/Fort Worth and Denver Air Route Traffic Control Centers. The ensuing development of the 4-D guidance algorithms, the necessary control laws and the operational procedures are discussed. Results of computer simulation evaluation of the guidance algorithms and control laws are presented, along with a description of the software development procedures utilized
Emergence of functional sensory subtypes as defined by transient receptor potential channel expression
The existence of heterogeneous populations of dorsal root ganglion (DRG) neurons conveying different somatosensory information is the basis for the perception of touch, temperature, and pain. A differential expression of transient receptor potential (TRP) cation channels contributes to this functional heterogeneity. However, little is known about the development of functionally diverse neuronal subpopulations. Here, we use calcium imaging of acutely dissociated mouse sensory neurons and quantitative reverse transcription PCR to show that TRP cation channels emerge in waves, with the diversification of functional groups starting at embryonic day 12.5 (E12.5) and extending well into the postnatal life. Functional responses of voltage-gated calcium channels were present in DRG neurons at E11.5 and reached adult levels by E14.5. Responses to capsaicin, menthol, and cinnamaldehyde were first seen at E12.5, E16.5, and postnatal day 0 (P0), when the mRNA for TRP cation channel, subfamily V, member 1 (TRPV1), TRP cation channel, subfamily M, member 8 (TRPM8), and TRP cation channel, subfamily A, member 1 (TRPA1), respectively, was first detected. Cold-sensitive neurons were present before the expression or functional responses of TRPM8 or TRPA1. Our data support a lineage relationship in which TRPM8- and TRPA1-expressing sensory neurons derive from the population of TRPV1-expressing neurons. The TRPA1 subpopulation of neurons emerges independently in two distinct classes of nociceptors: around birth in the peptidergic population and after P14 in the nonpeptidergic class. This indicates that neurons with similar receptive properties can be generated in different sublineages at different developmental stages. This study describes for the first time the emergence of functional subtypes of sensory neurons, providing new insight into the development of nociception and thermoreception
A Little Competition Never Hurt Anyone
Raise your hand if you\u27re taking this course because you want to become a nurse. Seventy hands shoot up. Seventy. This is only one Chem120 class. JJ Leary, my chemistry teacher, was merely trying to demonstrate how important the knowledge of basic chemistry concepts is in many common occupations. What Dr. Leary did not realize, however, is that he sparked a certain degree of fear and anger in those students aiming to get admitted into James Madison University\u27s nursing program. Immediately after the question was asked, eyes started darting around the room. You could feel other prospective nurses trying to discover your level of intelligence by the confidence, or lack thereof, plastered on your face. Yes, at eight in the morning on the second day of school, competitive sparks were already flying.
Rachael Leffler is currently a freshman here at JMU. She is a declared nursing major and hopes to get into the program fall semester of her junior year. She decided to write about the competitiveness of the nursing program because it applies to so many students here at James Madison. She also wants to show the school just how competitive occupational fields such as nursing can be
Curation and Reuse : An Experimental Study of Transverse Arrowheads of the Late Scandinavian Mesolithic
This article aims to examine whether it is possible to rework transversearrowheads while still hafted, in order to reuse them. Three series, eachcontaining three arrows, were shot into a target consisting of meat andbone. When possible, the arrowheads were retouched and fired again.The results of the experiments demonstrate that it is possible to reworktransverse arrowheads while they are hafted and that there may be strongstrategic and economic reasons to do so. A discussion of the results andcomparison with archaeological material follows the experiment, whichindicates that reworked arrowheads can be recognized in archaeologicalcontexts and that reworking changes arrowhead morphology. Thissuggests that formal typologies of lithic arrowheads that are based onmorpho-metric shape, and have been considered to reveal chronologicalor cultural affinities, may be flawed
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