NAVAL ENIGMA: SEAHORSE AND OTHER KRIEGSMARINE CIPHER BLUNDERS

Describes major weaknesses in a naval Enigma cipher codenamed Seahorse, and how it and similar naval Enigma ciphers were solved by US Navy codebreakers during WWII.     

Posttraining shifts in the overshadowing stimulus–unconditioned stimulus interval alleviates the overshadowing deficit.

Two conditioned lick suppression experiments explored the effects on overshadowing of a posttraining change in the temporal relationship between the overshadowing conditioned stimulus (CS) and the unconditioned stimulus (US). Rats received either trace (Experiment 1) or delay (Experiment 2) overshadowing training. Then pairings of the overshadowing CS and US were given with either a trace or delay temporal relationship. Overshadowing was alleviated by shifting the overshadowing CS–US temporal relationship so that it no longer matched the overshadowed CS–US temporal relationship. These outcomes are explicable in terms of an integration of the comparator hypothesis, which states that cue competition effects (e.g., overshadowing) will be maximal when the information potentially conveyed by competing CSs is equivalent, and the temporal coding hypothesis, which states that CS–US intervals are part of the information encoded during conditioning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Thermal diffusivity study of aged Li-ion batteries using flash method

Advanced Li-ion batteries with high energy and power density are fast approaching compatibility with automotive demands. While the mechanism of operation of these batteries is well understood, the aging mechanisms are still under investigation. Investigation of aging mechanisms in Li-ion batteries becomes very challenging, as aging does not occur due to a single process, but because of multiple physical processes occurring at the same time in a cascading manner. As the current characterization techniques such as Raman spectroscopy, X-ray diffraction, and atomic force microscopy are used independent of each other they do not provide a comprehensive understanding of material degradation at different length (nm² to m²) scales. Thus to relate the damage mechanisms of the cathode at mm length scale to micro/nanoscale, data at an intermediate length scale is needed. As such, we demonstrate here the use of thermal diffusivity analysis by flash method to bridge the gap between different length scales. In this paper we present the thermal diffusivity analysis of an unaged and aged cell. Thermal diffusivity analysis maps the damage to the cathode samples at millimeter scale lengths. Based on these maps we also propose a mechanism leading to the increase of the thermal diffusivity as the cells are aged.     

The amygdala's role in long-term declarative memory for gist and detail.

In humans, the emotional nature of stimuli appears to have a complex influence on long-term declarative memory for those stimuli: Whereas emotion enhances memory for gist, it may suppress memory for detail. On the basis of prior studies, the authors hypothesized that the amygdala helps mediate the above 2 effects. Long-term memory for gist and for visual detail of aversive and neutral scenes was assessed in 20 subjects with unilateral amygdala damage and 1 rare subject with bilateral amygdala damage. Comparisons with 2 control groups (15 brain-damaged and 47 healthy) provided evidence that bilateral, but not unilateral, damage to the amygdala results in poorer memory for gist but superior memory for visual details. The pattern of findings provides preliminary support for the idea that the amygdala may help filter the encoding of relevant information from stimuli that signal threat or danger. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Factors Influencing the Adhesion of Microorganisms to Surfaces

Starvation, growth phase, and carbon source influenced bacterial cell surface hydrophobicity. Both the number and kind of microorganisms that colonized metal surfaces depended on the type of metal and the presence of an imposed electrical potential. No significant differences in attachment and growth of a pure culture were observed when metal surfaces were dipped in an exogenous energy source. The chemical composition of naturally occurring adsorbed organic films on metal surfaces was shown to be independent of surface composition and polarization.     

Assignment of features in impedance spectra of the cement-paste/steel system

This paper presents a systematic study of the features seen in typical Nyquist plots (-imaginary vs. real impedance) for cement-paste/steel systems and discusses the assignment of each feature to its appropriate origin, e.g., bulk, contact, interface, product layer, etc. Assignments are made based upon as many considerations as possible—dc measurements, sample geometry, capacitance, local chemical modifications, alternative electroding schemes, etc. In addition to three distinct arcs from lowest (mHz) frequency to highest (MHz) frequency (due to product layer, interfacial reaction, and bulk, respectively), a fourth arc is sometimes observed between the bulk and interface arcs. When this occurs in paste-only systems, this arc is attributable to imperfect electrodes due to drying/shrinkage. In composite systems, e.g., cement with conductive chopped fibers added, this arc is clearly a “bulk” feature and an important indicator of microstructural inhomogeniety.     

Color variability of wine in a glass and general comments on contrast effects

When red wines are tilted in a glass wine sampler and observed in strong light against a neutral background, the thinner parts appear a shorter wavelength red than the thicker ones. It is discussed whether these hue‐shifts, associated with thickness changes, are attributable to simultaneous contrast effects (Bezold–Brucke and Abney effects) or can be detected by conventional instrumental color measurement by spectroradiometer or spectrophotometer (assuming Bouguer's law). The reported hue‐shifts at different thicknesses appear to be attributable to both physical‐chemical changes and contrast effects. This discussion is in three parts: (1) Color variability of wine in a glass and general comments on contrast effects by Ralph W. Pridmore, (2) Color coordinates of wine samples with different thicknesses by Rafael Huertas, Manuel Melgosa, and Angel I. Negueruela, and (3) Final Comment by Ralph W. Pridmore. © 2005 Wiley Periodicals, Inc. Col Res Appl, 30, 146–152, 2005     

Association Among Parental Substance Use Disorder, P300 Amplitude, and Neurobehavioral Disinhibition in Preteen Boys at High Risk for Substance Use Disorder.

The P300 amplitude of the event-related potential as a mediator of the association between parental substance use disorder (SUD) and child's neurobehavioral disinhibition was assessed. The P300 amplitude was recorded using an oddball task in sons of fathers having either lifetime SUD (n = 105) or no psychiatric disorder (n = 160). Neurobehavioral disinhibition was assessed using measures of affect regulation, behavior control, and executive cognitive function. Parental SUD and child's P300 amplitude accounted for, respectively, 16.6% and 16.8% of neurobehavioral disinhibition variance. Controlling for parental and child psychopathology, an association between parental SUD and child's P300 amplitude was not observed. It was concluded that the P300 amplitude does not mediate the association between parental SUD and child's neurobehavioral disinhibition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)