A Transfer of Training Study of Control Loader Dynamics

The control inceptor used in a simulated vehicle is an important part in maintaining the fidelity of a simulation. The force feedback provided by the control inceptor gives the operator important cues to maintain adequate performance. The dynamics of a control inceptor are typically based on a second order spring mass damper system with damping, force gradient, breakout force, and natural frequency parameters. Changing these parameters can have a great effect on pilot or driver control of the vehicle. The neuromuscular system has a very important role in manipulating the control inceptor within a vehicle. Many studies by McRuer, Aponso, and Hess have dealt with modeling the neuromuscular system and quantifying the effects of a high fidelity control loader as compared to a low fidelity control loader. Humans are adaptive in nature and their control behavior changes based on different control loader dynamics. Humans will change their control behavior to maintain tracking bandwidth and minimize tracking error. This paper reports on a quasi-transfer of training experiment which was performed at the NASA Langley Research Center. The quasi transfer of training study used a high fidelity control loader and a low fidelity control loader. Subjects trained in both simulations and then were transferred to the high fidelity control loader simulation. The parameters for the high fidelity control loader were determined from the literature. The low fidelity control loader parameters were found through testing of a simple computer joystick. A disturbance compensatory task is employed. The compensatory task involves implementing a simple horizon out the window display. A disturbance consisting of a sum of sines is used. The task consists of the subject compensating for the disturbance on the roll angle of the aircraft. The vehicle dynamics are represented as 1/s and 1/s2. The subject will try to maintain level flight throughout the experiment. The subjects consist of non-pilots to remove any effects of pilot experience. First, this paper discusses the implementation of the disturbance compensation task. Second, the high and low fidelity parameters used within the experiment are presented. Finally, an explanation of results from the experiments is presented

FRAP, FLIM, and FRET: Detection and analysis of cellular dynamics on a molecular scale using fluorescence microscopy

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/112297/1/mrd22501.pd

Investigation of Control Inceptor Dynamics and Effect on Human Subject Performance

The control inceptor used in a vehicle simulation is an important part of adequately representing the dynamics of the vehicle. The inceptor characteristics are typically based on a second order spring mass damper system with damping, force gradient, breakout force, and natural frequency parameters. Changing these parameters can have a great effect on pilot control of the vehicle. A quasi transfer of training experiment was performed employing a high fidelity and a low fidelity control inceptor. A disturbance compensatory task was employed which involved a simple horizon line disturbed in roll by a sum of sinusoids presented in an out-the-window display. Vehicle dynamics were modeled as 1/s and 1/s2. The task was to maintain level flight. Twenty subjects were divided between the high and the low fidelity training groups. Each group was trained to a performance asymptote, and then transferred to the high fidelity simulation. RMS tracking error, a PSD analysis, and a workload analysis were performed to quantify the transfer of training effect. Quantitative results of the experiments show that there is no significant difference between the high and low fidelity training groups for 1/s plant dynamics. For 1/s2 plant dynamics there is a greater difference in tracking performance and PSD; and the subjects are less correlated with the input disturbance functio

UC must take lead in curricula reform, teacher training

California, once reputed to have the best public education system in the nation, finds itself ranked at or near the bottom at the end of the 20th century. Traditionally, the University of California has not been deeply involved in K-12 education, but the social and economic cost of an undereducated work-force in a global economy makes it imperative that all segments of California's system of higher education — including UC — get involved. The University can directly improve our public schools through outreach programs. At the same time, UC needs to improve its own curriculum, particularly in science and mathematics, and especially for prospective teachers. To prepare graduates for an increasingly technological world, curricula must be more interdisciplinary and inquiry-based, for science and for nonscience majors alike By breaking down traditional barriers that have prevented UC faculty from participating in curriculum reform efforts, UC can play a leadership role in providing Californians the skills and knowledge necessary to succeed in the next century

UC must take lead in curricula reform, teacher training

California, once reputed to have the best public education system in the nation, finds itself ranked at or near the bottom at the end of the 20th century. Traditionally, the University of California has not been deeply involved in K-12 education, but the social and economic cost of an undereducated work-force in a global economy makes it imperative that all segments of California's system of higher education — including UC — get involved. The University can directly improve our public schools through outreach programs. At the same time, UC needs to improve its own curriculum, particularly in science and mathematics, and especially for prospective teachers. To prepare graduates for an increasingly technological world, curricula must be more interdisciplinary and inquiry-based, for science and for nonscience majors alike By breaking down traditional barriers that have prevented UC faculty from participating in curriculum reform efforts, UC can play a leadership role in providing Californians the skills and knowledge necessary to succeed in the next century

Polarized Light Microscopy, Variability in Spider Silk Diameters, and the Mechanical Characterization of Spider Silk

Spider silks possess a remarkable combination of high tensile strength and extensibility that makes them among the toughest materials known. Despite the potential exploitation of these properties in biotechnology, very few silks have ever been characterized mechanically. This is due in part to the difficulty of measuring the thin diameters of silk fibers. The largest silk fibers are only 5–10 μm in diameter and some can be as fine as 50 nm in diameter. Such narrow diameters, coupled with the refraction of light due to the anisotropic nature of crystalline regions within silk fibers, make it difficult to determine the size of silk fibers. Here, we report upon a technique that uses polarized light microscopy (PLM) to accurately and precisely characterize the diameters of spider silk fibers. We found that polarized light microscopy is as precise as scanning electron microscopy (SEM) across repeated measurements of individual samples of silk and resulted in mean diameters that were ∼0.10 μm larger than those from SEM. Furthermore, we demonstrate that thread diameters within webs of individual spiders can vary by as much as 600%. Therefore, the ability of PLM to non-invasively characterize the diameters of each individual silk fiber used in mechanical tests can provide a crucial control for natural variation in silk diameters, both within webs and among spiders

Data from: How fish eggs are preadapted for the evolution of matrotrophy

Teleost fishes evolved livebearing via egg retention 14 times. Matrotrophy has evolved within 12 of those lineages. By contrast, squamate reptiles evolved livebearing over 115 times, but only two to four of those lineages are known to have evolved matrotrophy. Is the discrepancy between these organisms in the probability of this transition caused by differences in their eggs? We show that the eggs of oviparous species in the superorder Atherinomorpha can acquire small organic molecules from their surrounding environment against a concentration gradient via mechanisms of active transport. Uptake rates were inhibited by competing radiolabelled amino acids against unlabelled versions of themselves. Transport was non-specific as uptake rates were similar for l-leucine and its biologically uncommon enantiomer d-leucine. Eggs are also capable of transporting larger microspheres across the membrane, but transport is inhibited at temperatures below 4°C, suggesting active transport occurs via pinocytosis. Conflict theory predicts that the ability of the egg to acquire maternal resources will facilitate the embryo–parent arms race that leads to the evolution of matrotrophy following the transition to livebearing. The shelled eggs of amniotes lack such access to maternal resources when retained in the evolution of viviparity

Using the Culex pipiens sperm proteome to identify elements essential for mosquito reproduction.

Mature sperm from Culex pipiens were isolated and analyzed by mass spectrometry to generate a mature sperm proteome dataset. In this study, we highlight subsets of proteins related to flagellar structure and sperm motility and compare the identified protein components to previous studies examining essential functions of sperm. The proteome includes 1700 unique protein IDs, including a number of uncharacterized proteins. Here we discuss those proteins that may contribute to the unusual structure of the Culex sperm flagellum, as well as potential regulators of calcium mobilization and phosphorylation pathways that regulate motility. This database will prove useful for understanding the mechanisms that activate and maintain sperm motility as well as identify potential molecular targets for mosquito population control