Predator avoidance of noxious prey, aposematism and defensive mimicry are normally associated with bright, contrasting patterns colours. However, prey may be unable to evolve conspicuous coloration because other selective constraints, such as the need inconspicuous their own or specialist predators. Many venomous snakes, particularly most vipers, display that apparently cryptic, but nevertheless highly characteristic, appear mimicked by other, non-venomous snakes. predator viper has never...

The chemical bonding and electronic properties of ${\mathrm{Pd}}_{2}$Si have been investigated by measuring ultraviolet photoemission spectroscopy Auger electron transitions involving both core valence electrons for Pd, Si, ${\mathrm{Pd}}_{2}$Si. spectra interpreted based on partial state densities calculated Pd-Si compounds. In the silicide, $d$ states Pd interact strongly with $p$ Si. resulting $p\ensuremath{-}d$ hybrid complex is composed lying almost entirely below ${E}_{F}$ central peak...

The decomposition of oxide films 50 to 500 Å on Si(100) during ultrahigh vacuum anneal has been studied in a scanning Auger microscope. the occurs locally, that voids form and grow laterally with time temperature, leaving areas between unperturbed. Void growth kinetics data are derived from situ absorbed current secondary electron imaging anneal. void diameter is found be linear an activation energy 2.0±0.25 eV. This implies rates after nucleation phase dominated by chemical reactions and/or...

An experimental investigation of the boundary layer separation associated with a compression corner was conducted in GALCIT Mach 6 wind tunnel, and supplementary study performed JPL supersonic tunnel. Special emphasis placed on development tunnel model which approximated true two-dimensional flow, could be run either highly cooled or an adiabatic configuration. The basic measurements consist surface pressure temperature, Pitot surveys layer. distributions for wall configurations are compared...

The electronic structure of the clean Pd/Si(111) and Pd/Si(100) interfaces has been investigated using angle-integrated angle-resolved ultraviolet photoemission (UPS) Auger electron spectroscopies (AES), in conjunction with transmission microscopy (TEM), work-function, low-energy diffraction measurements. Since interface is highly reactive, studies were made by processing reaction two ways: (i) sequential annealing steps thick metal overlayers, (ii) deposition very thin considerably less...

SUMMARY Brown ghost knifefish, Apteronotus leptorhynchus, are a species of weakly electric fish that produce continuous organ discharge (EOD)that is used in navigation, prey capture and communication. Stereotyped modulations EOD frequency amplitude common social situations thought to serve as communication signals. Of these modulations, the most commonly studied chirp. This study presents quantitative analysis chirp production pairs free-swimming, physically interacting male female A....

Adult zebrafish exhibit hyperventilatory responses to absolute environmental CO 2 levels as low 0.13% ( mmHg), more than an order of magnitude lower the typical arterial (∼40 mmHg) monitored by mammalian carotid body. The sensory basis underlying ability fish detect and respond ambient is not clear. Here, we show that neuroepithelial cells (NECs) gill, known sense O levels, also . An electrophysiological characterization this response using both current voltage clamp protocols revealed for...

The decomposition of ${\mathrm{SiO}}_{2}$ films on Si(100) during ultrahigh-vacuum anneal is studied in a scanning Auger microscope. Decomposition found to be strongly enhanced by monolayer amounts impurities deposited the surface. s- and p-band elements initiate via formation volatile suboxides surface reaction. In contrast, most transition metals decompose oxide laterally inhomogeneous growth voids oxide, suggesting that they need diffuse ${\mathrm{SiO}}_{2}$/Si interface there enhance...

It is well-known that weakly electric fish can exhibit extreme temporal acuity at the behavioral level, discriminating time intervals in submicrosecond range. However, relatively little known about spatial of electrosense. Here we use a recently developed model field generated by Apteronotus leptorhynchus to study and small signal extraction. We show quality sensory information available on lateral body surface highest for objects close fish's midbody, suggesting should be this location....

Short-term synaptic plasticity (STP) can significantly alter the amplitudes of responses in ways that depend on presynaptic history. Thus, it is widely assumed STP acts as a filter for specific patterns inputs, and result play key roles neuronal information processing. To evaluate this assumption directly quantify effects transmission, we consider population independent inputs to model neuron. We show using standard theoretic approaches changes response amplitude resulting from interact with...

Views Icon Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Twitter Facebook Reddit LinkedIn Tools Reprints and Permissions Cite Search Site Citation P. S. Ho, J. E. Lewis, K. Howard; Auger study of preferred sputtering on Ag–Au alloy surfaces. Vac. Sci. Technol. 1 January 1977; 14 (1): 322–325. https://doi.org/10.1116/1.569199 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search...

The perturbation of pre-existing surface gravity waves caused by the presence an internal wave was studied both experimentally and analytically. An extensive series experiments performed, quantitative results were obtained for one-dimensional monochromatic interaction waves. Internal wave-induced slope, amplitude wavenumber modulations measured a wide range conditions. A complementary theoretical analysis, based on conservation approach Whitham (1962) Longuet-Higgins & Stewart...

Abstract The reflectance spectra of bulk samples the germanium telluride (GeTe) system have been measured in wavelength range 13 to 0.2 μm. principal optical constants obtained by inverting using Kramers‐Kronig technique. Two distinct types behavior were encountered depending on whether or not a sample exhibited free carrier absorption peak. Samples rich lacked such peak and had properties very similar amorphous GeTe films. Tellurium always showed large from analysis their Constants...

Interactions among animals can result in complex sensory signals containing a variety of socially relevant information, including the number, identity, and relative motion conspecifics. How spatiotemporal properties such evolving naturalistic are encoded is key question neuroscience. Here, we present results from experiments modeling that address this issue context electric sense, which combines spatial aspects vision touch, with temporal audition. Wave-type fish, as brown ghost knifefish,...

Abstract The measured transport properties of non‐stoichiometric GeTe have been satisfactorily analysed on the basis a two‐carrier model and various band parameters evaluated. In particular variation carrier density system with composition has obtained then compared to total number excess atoms in lattice. It is found that defects occurring due these are complex nature, except for compositions close stoichiometry where singly ionized vacancies dominant defect.

SUMMARY Weakly electric fish characterize the environment in which they live by sensing distortions their self-generated field. These result images forming across skin. In order to better understand field generation and image formation one particular species of fish, Apteronotus leptorhynchus, we have developed three different numerical models a two-dimensional cross-section fish's body its surroundings. One these mimics real contour fish; two other geometrically simple allow for an...

Weakly electric fish can enhance the detection and localization of important signals such as those prey in part by cancellation redundant spatially diffuse due to, e.g., their tail bending. The mechanism is based on descending input, conveyed parallel fibers emanating from cerebellar granule cells, that produces a negative image global low-frequency pyramidal cells within first-order electrosensory region, lateral line lobe (ELL). Here we demonstrate fiber synaptic input to ELL cell...