Explicit and Implicit Processes in Human Aversive Conditioning

The ability to adapt to a changing environment is central to an organism’s success. The process of associating two stimuli (as in associative conditioning) requires very little in the way of neural machinery. In fact, organisms with only a few hundred neurons show conditioning that is specific to an associated cue. This type of learning is commonly referred to as implicit learning. The learning can be performed in the absence of the subject’s ability to describe it. One example of learning that is thought to be implicit is delay conditioning. Delay conditioning consists of a single cue (a tone, for example) that starts before, and then overlaps with, an outcome (like a pain stimulus). In addition to associating sensory cues, humans routinely link abstract concepts with an outcome. This more complex learning is often described as explicit since subjects are able to describe the link between the stimulus and outcome. An example of conditioning that requires this type of knowledge is trace conditioning. Trace conditioning includes a separation of a few seconds between the cue and outcome. Explicit learning is often proposed to involve a separate system, but the degree of separation between implicit associations and explicit learning is still debated. We describe aversive conditioning experiments in human subjects used to study the degree of interaction that takes place between explicit and implicit systems. We do this in three ways. First, if a higher order task (in this case a working memory task) is performed during conditioning, it reduces not only explicit learning but also implicit learning. Second, we describe the area of the brain involved in explicit learning during conditioning and confirm that it is active during both trace and delay conditioning. Third, using functional magnetic resonance imaging (fMRI), we describe hemodynamic activity changes in perceptual areas of the brain that occur during delay conditioning and persist after the learned association has faded. From these studies, we conclude that there is a strong interaction between explicit and implicit learning systems, with one often directly changing the function of the other.</p

Forum: Literature and Language Awareness: Using Literature to Achieve CEFR Outcomes

This article sets out to explore why literature (used in this article to mean poetry, plays, short stories or novels) is often a marginalised resource in EFL classrooms, even though the Common European Framework of References for Languages (CEFR) suggests it should have a role in the classroom. It first reports on the results of a questionnaire investigating English teachers’ attitudes towards using literature in the classroom. After a discussion of these results, it explores some ways in which the use of literature can be linked to CEFR outcomes in a practical teaching framework which teachers can apply to literature they choose to teach

A laboratory study of the transmission of signals through solid material with possible application to seismic communication

The problem of transmitting acoustic signals through solid material channels is investigated using piezoelectric transducers for generation and detection of the signals. Laboratory experiments are performed in which a solid material channel is modeled by a block of Berea sandstone. The magnitude of the frequency response for the sandstone and transducer combination is obtained over the frequency range of approximately 0 Hz to 500 kHz. Various electrical waveforms are utilized as driving sources for the transmitting transducer. It is found that the best received waveform is obtained when a gated sinewave whose frequency is approximately equal to the resonant frequency of the transducer is used as the driving source. Based on the experimental results obtained, a communication system is proposed in which seismic noise is assumed to be negligible in the frequency range of interest --Abstract, page ii

Passive wireless antenna sensor for strain, temperature, crack and fatigue measurement

An apparatus and method is provided for monitoring a condition of a structure using a passive wireless antenna sensor having a known resonant frequency when mounted on the structure. A series of radio frequency signals are transmitted with sweeping frequencies around the known resonant frequency to the passive wireless antenna sensor. The passive wireless antenna sensor includes a dielectric substrate disposed between an antenna pattern and a ground plane such that a change in the condition of the structure will cause a change in one or more characteristics of the passive wireless sensor. A signal is received from the passive wireless antenna sensor and a resonant frequency of the passive wireless antenna sensor is determined based on the received signal. The determined resonant frequency is then compared to the known resonant frequency, whereby a change in the resonant frequency indicates a change in the condition of the structure.Board of Regents, University of Texas Syste

Discourse of 'transformational leadership' in infection control

The article explores the impact of the 'transformational leadership' style in the role of modern matron with regards to infection control practices. Policy and guidance on the modern matron role suggest that it is distinctive in its combination of management and clinical components, and in its reliance on transformational leadership. Senior nurses are therefore expected to motivate staff by creating high expectations, modelling appropriate behaviour, and providing personal attention to followers by giving respect and responsibility. In this article, we draw on policy documents and interview data to explore the potential impact of this new management style on infection control practices. Combining the techniques of discourse analysis and corpus linguistics, we identify examples where matrons appear to disassociate themselves from the role of `an empowered manager' who has control over human and financial resources to resolve problems in infection control efficiently

Robotic Manufacturing of 18-ft (5.5m) Diameter Cryogenic Fuel Tank Dome Assemblies for the NASA Ares I Rocket

The Ares I rocket was the first launch vehicle scheduled for manufacture under the National Aeronautic and Space Administration's Constellation program. A series of full-scale Ares I development articles were constructed on the Robotic Weld Tool at the NASA George C. Marshall Space Flight Center in Huntsville, Alabama. The Robotic Weld Tool is a 100 ton, 7- axis, robotic manufacturing system capable of machining and friction stir welding large-scale space hardware. This paper will focus on the friction stir welding of 18-ft (5.5m) diameter cryogenic fuel tank components; specifically, the liquid hydrogen forward dome and two common bulkhead manufacturing development articles

Preliminary Studies Demonstrating Acetoclastic Methanogenesis in a Rat Colonic Ring Model

Washed rat colonic rings were incubated in closed flasks under N2 at physiologic pH and temperature levels. In the absence of an exogenous substrate, negligible H2 but some CH4 concentrations were detected in vitro after one hour of incubation, but high concentrations (H2 > 100 ppm, CH4 > 10 ppm) of both gases were found after 24 hours of culture. Production of H2 and CH4 by the washed colonic rings was stimulated by lactose addition. Maximum H2 production occurred at about pH 7.0, while maximum CH4 production occurred between pH 4.0 and 6.0. The increased production of both gases at 24 hours was associated with dramatic increases (104-fold) in anaerobic bacteria colony counts on the colonic rings and in the incubation media, as well as dramatic increases (100-fold) in acetate concentrations in the media, while lactate concentrations first rose and then fell significantly. These results suggest that gas production in colonic ring preparations is subject to quantitative changes in microbiota, pH, and metabolite formation analogous to in vivo conditions. In addition, microbiota firmly attached to colonic tissue appears to utilize colonic tissue to support its growth in the absence of an exogenous substrate

Manufacturing of 5.5 Meter Diameter Cryogenic Fuel Tank Domes for the NASA Ares I Rocket

The Ares I rocket is the first launch vehicle scheduled for manufacture under the National Aeronautic and Space Administration s (NASA s) Constellation program. A series of full-scale Ares I development articles have been constructed on the Robotic Weld Tool at the NASA George C. Marshall Space Flight Center in Huntsville, Alabama. The Robotic Weld Tool is a 100 ton, 7-axis, robotic manufacturing system capable of machining and friction stir welding large-scale space hardware. This presentation will focus on the friction stir welding of 5.5m diameter cryogenic fuel tank components; specifically, the liquid hydrogen forward dome (LH2 MDA) and the common bulkhead manufacturing development articles (CBMDA). The LH2 MDA was the first full-scale, flight-like Ares I hardware produced under the Constellation Program. It is a 5.5m diameter elliptical dome assembly consisting of eight gore panels, a y-ring stiffener and a manhole fitting. All components are made from aluminum-lithium alloy 2195. Conventional and self-reacting friction stir welding was used on this article. Manufacturing solutions will be discussed including the implementation of photogrammetry, an advanced metrology technique, as well as fixtureless welding. The LH2 MDA is the first known fully friction stir welded dome ever produced. The completion of four Common Bulkhead Manufacturing Development Articles (CBMDA) will also be highlighted. Each CBMDA consists of a 5.5m diameter spun-formed dome friction stir welded to a y-ring stiffener. The domes and y-rings are made of aluminum 2014 and 2219 respectively. An overview of CBMDA manufacturing processes and the effect of tooling on weld defect formation will be discussed

YIG Oscillators: Is a Planar Geometry Better?

Two yttrium-iron-garnet (YIG) oscillator technologies are comparerk the more mature YIG sphere oscillator technology which is based on the uniform (resonant) precession of the electron spins in a smafl sphere of YIG, and the new planar YIG technology which utilizes the propagation of magnetostatic waves in an epitaxiaf film of YIG. The YIG sphere technology has been used for microwave oscillators for more than 25 years, but has two significant areas of difficulty in applications the alignment of the YIG sphere in the magnetic bias field coupfbrg cavity requires great precision and the gain element requires a negative resistance element to sustain oscillation. The MSW technology is much newer and less well understood, but the resonator elements are fabricated using a 50- pm line width planar technology making it assappealhg candidate. Both technologies are reviewed herein with regard to resonant element theory, temperature, and noise characteristics. New data and theory are presented on MSW resonator optimization