2,639 research outputs found
Air-cushion lift pad
Mathematical model is formulated for an air pad which is capable of lifting a structure to a height of 0.125 inch. Design is superior to conventional air cushion devices because it eliminates flutter, vibration, heaving, and pitching
Advanced action manipulator system (ADAMS)
Manipulator offers improved performance over other models in its category. It features larger force and reach capabilities and is readily convertible for underwater use. Unique kinematic arrangement provides extremely large working envelope. System has six degrees of motion: azimuth joint, shoulder joint, upper arm rotating joint, elbow joint, wrist pitch, and wrist twist
The change of electric field and of some other insulating properties during isochronal annealing in thermally poled Ge-doped silica films
Plasmodium vivax-like genome sequences shed new insights into Plasmodium vivax biology and evolution
Although Plasmodium vivax is responsible for the majority of malaria infections outside Africa, little is known about its evolution and pathway to humans. Its closest genetic relative, P. vivax-like, was discovered in African great apes and is hypothesized to have given rise to P. vivax in humans. To unravel the evolutionary history and adaptation of P. vivax to different host environments, we generated using long- and short-read sequence technologies 2 new P. vivax-like reference genomes and 9 additional P. vivax-like genotypes. Analyses show that the genomes of P. vivax and P. vivax-like are highly similar and colinear within the core regions. Phylogenetic analyses clearly show that P. vivax-like parasites form a genetically distinct clade from P. vivax. Concerning the relative divergence dating, we show that the evolution of P. vivax in humans did not occur at the same time as the other agents of human malaria, thus suggesting that the transfer of Plasmodium parasites to humans happened several times independently over the history of the Homo genus. We further identify several key genes that exhibit signatures of positive selection exclusively in the human P. vivax parasites. Two of these genes have been identified to also be under positive selection in the other main human malaria agent, P. falciparum, thus suggesting their key role in the evolution of the ability of these parasites to infect humans or their anthropophilic vectors. Finally, we demonstrate that some gene families important for red blood cell (RBC) invasion (a key step of the life cycle of these parasites) have undergone lineage-specific evolution in the human parasite (e.g., reticulocyte-binding proteins [RBPs])
Second-Hand Stress: Neurobiological Evidence for a Human Alarm Pheromone
Alarm pheromones are airborne chemical signals, released by an individual into the environment, which transmit warning of danger to conspecifics via olfaction. Using fMRI, we provide the first neurobiological evidence for a human alarm pheromone. Individuals showed activation of the amygdala in response to sweat produced by others during emotional stress, with exercise sweat as a control; behavioral data suggest facilitated evaluation of ambiguous threat
Optical investigation of thermoelectric topological crystalline insulator PbSnSe
PbSnSe is a novel alloy of two promising thermoelectric
materials PbSe and SnSe that exhibits a temperature dependent band inversion
below 300 K. Recent work has shown that this band inversion also coincides with
a trivial to nontrivial topological phase transition. To understand how the
properties critical to thermoelectric efficiency are affected by the band
inversion, we measured the broadband optical response of
PbSnSe as a function of temperature. We find clear optical
evidence of the band inversion at K, and use the extended Drude
model to accurately determine a dependence of the bulk carrier
lifetime, associated with electron-acoustic phonon scattering. Due to the high
bulk carrier doping level, no discriminating signatures of the topological
surface states are found, although their presence cannot be excluded from our
data.Comment: 11 pages, 6 figure
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