5,647 research outputs found
A short survey of the environment at the dumping site for Santa Cruz Harbor dredging and A study of seaward dipping internal structures in marine ripple marks at Whaler's Cove, California. Annual report, Part 4, August 1972
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An Imagination Effect in Learning From Scientific Text
Asking students to imagine the spatial arrangement of the elements in a scientific text constitutes a learning strategy intended to foster deep processing of the instructional material. Two experiments investigated the effects of mental imagery prompts on learning from scientific text. Students read a computer-based text on the human respiratory system (control group), read while being asked to form an image corresponding to each of 9 paragraphs (imagery group), or read while being asked to form an image and with seeing an onscreen drawing before each paragraph (picture- before-imagery group) or after each paragraph (picture-after-imagery group). Imagery prompts facilitated transfer and retention performance compared to a control group on an immediate test (Experiment 1: d = 1.30 on transfer, d = 0.74 on retention) and on a delayed test (Experiment 2: d = 0.86 on transfer, d = 0.98 on retention), but the added drawings had no additional effect. The findings support the imagination principle, which states that people learn more deeply when prompted to form images depicting the spatial arrangement of what they are reading
Enhanced Electrochemistry of Nanoparticle-Embedded Polyelectrolyte Films: Interfacial Electronic Coupling and Distance Dependence
Factors affecting the electronic communication believed to be responsible for the enhanced solution electrochemistry observed at electrodes modified with hybrid polyelectrolyte–nanoparticle (PE–NP) film assemblies were systematically investigated. Specifically, the faradaic current and voltammetric peak splitting recorded for cyclic voltammetry of ferricyanide redox species (Fe(CN)63−/4−) at films constructed with various architectures of citrate-stabilized gold NPs embedded in polyelectrolyte films composed of poly-l-lysine and poly-S-styrene were used to establish the relative importance of both distance and electronic coupling. Layer-by-layer construction of PE–NP films allowed for the position and density of NPs to be varied within the film to assess electronic coupling between particles (interparticle coupling) as well as at the electrode–film interface. The cumulative results observed at these films suggest that, while distance dependence prevails in nearly every case and interparticle coupling can contribute to facilitating the Fe(CN)63−/4− electrochemistry, interfacial electronic coupling of the PE–NP films is of critical importance and decoupling is easily achieved by disengaging NP–electrode interactions
The Power of Imagination and Perspective in Learning From Science Text
In 2 experiments, college students read a 4-paragraph text on how the human circulatory system works and were instructed to form a mental image of the events described in each paragraph from the perspective of their own body (first-person perspective group) or from the perspective of a fictitious person facing them (third-person perspective group), or were given no imagination instructions (control group). Students who imagined from a first-person perspective outperformed the control group on solving transfer problems, retaining important material, and not retaining unimportant material in Experiments 1 and 2, confirming the benefits of combining imagination and perspective into a powerful learning strategy. Students who imagined from a first-person perspective outperformed students who imagined from a third-person perspective on solving transfer problems in Experiments 1 and 2, indicating the value of adding first-person perspective to imagination for fostering deeper understanding. Students who imagined from a third-person perspective outperformed the control group on solving transfer problems and on not retaining unimportant material in Experiment 1 (which included specific prompts for which items to include in one's images), whereas they did not perform significantly better than the control group on any measures in Experiment 2 (which did not include specific prompts). This finding suggests that imagination without first-person perspective can be ineffective when there is not support for imagining during learning. These findings have theoretical implications for the role of embodiment in generative learning theory, and practical implications for modifying the imagination principle to recommend imagining from a first-person perspective
Combining degradations: The effect of background noise on intelligibility of disordered speech
The effect of background noise on intelligibility of disordered speech was assessed. Speech-shaped noise was mixed with neurologically healthy (control) and disordered (dysarthric) speech at a series of signal-to-noise ratios. In addition, bandpass filtered control and dysarthric speech conditions were assessed to determine the effect of noise on both naturally and artificially degraded speech. While significant effects of both the amount of noise and the type of speech were revealed, no interaction between the two factors was observed, in either the broadband or filtered testing conditions. Thus, it appears that there is no multiplicative effect of the presence of background noise on intelligibility of disordered speech relative to control speech. That is, the decrease in intelligibility due to increasing levels of noise is similar for both types of speech, and both types of testing conditions, and the function for dysarthric speech is simply shifted downward due to the inherent source degradations of the speech itself. Last, large-scale online crowdsourcing via Amazon Mechanical Turk was utilized to collect data for the current study. Findings and implications for this data and data collection approach are discussed
Individualized Frequency Importance Functions for Listeners with Sensorineural Hearing Loss
The Speech Intelligibility Index includes a series of frequency importance functions for calculating the estimated intelligibility of speech under various conditions. Until recently, techniques to derive frequency importance required averaging data over a group of listeners, thus hindering the ability to observe individual differences due to factors such as hearing loss. In the current study, the “random combination strategy” [Bosen and Chatterjee (2016). J. Acoust. Soc. Am. 140, 3718–3727] was used to derive frequency importance functions for individual hearing-impaired listeners, and normal-hearing participants for comparison. Functions were measured by filtering sentences to contain only random subsets of frequency bands on each trial, and regressing speech recognition against the presence or absence of bands across trials. Results show that the contribution of each band to speech recognition was inversely proportional to audiometric threshold in that frequency region, likely due to reduced audibility, even though stimuli were shaped to compensate for each individual\u27s hearing loss. The results presented in this paper demonstrate that this method is sensitive to factors that alter the shape of frequency importance functions within individuals with hearing loss, which could be used to characterize the impact of audibility or other factors related to suprathreshold deficits or hearing aid processing strategies
Neurons in the primate medial basal forebrain signal combined information about reward uncertainty, value, and punishment anticipation
It has been suggested that the basal forebrain (BF) exerts strong influences on the formation of memory and behavior. However, what information is used for the memory-behavior formation is unclear. We found that a population of neurons in the medial BF (medial septum and diagonal band of Broca) of macaque monkeys encodes a unique combination of information: reward uncertainty, expected reward value, anticipation of punishment, and unexpected reward and punishment. The results were obtained while the monkeys were expecting (often with uncertainty) a rewarding or punishing outcome during a Pavlovian procedure, or unexpectedly received an outcome outside the procedure. In vivo anterograde tracing using manganese-enhanced MRI suggested that the major recipient of these signals is the intermediate hippocampal formation. Based on these findings, we hypothesize that the medial BF identifies various contexts and outcomes that are critical for memory processing in the hippocampal formation
Observation of the diocotron instability in a diode with split cathode
Diocotron instability has been observed in the pure electron plasma formed in
a split cathode coaxial diode. This plasma consists of electrons, trapped in
the longitudinal potential well between the two parts of the cathode. The
mathematical model of the electron squeezed state, which allows calculation of
the equilibrium plasma density, is presented. The model is applied in a
comprehensive analysis of experimental data and the presence of the diocotron
instability is unambiguously confirmed.Comment: Accepted for publication in Physics of Plasma
A spatio-temporal life cycle assessment framework for building renovation scenarios at the urban scale
Reducing the energy consumption of buildings is a priority for carbon emissions mitigation in urban areas. Building stock energy models have been developed to support decisions of public authorities in renovation strategies. However, the burdens of renovation interventions and their temporal distribution are mostly overlooked, leading to potential overestimation of environmental benefits. Life Cycle Assessment (LCA) provides a holistic estimation of environmental impacts, but further developments are needed to correctly consider spatio-temporal aspects.
We propose a spatio-temporal LCA framework to assess renovation scenarios of urban housing stocks, integrating: 1) a geospatial building-by-building stock model, 2) energy demand modelling, 3) product-based LCA, and 4) a scenario generator. Temporal aspects are considered both in the lifecycle inventory and the lifecycle impact assessment phases, by accounting for the evolution of the existing housing stock and applying time-adjusted carbon footprint calculation.
We apply the framework for the carbon footprint assessment of housing renovation in Esch-sur-Alzette (Luxembourg). Results show that the renovation stage represents 4%–16% of the carbon footprint in the residual service life of existing buildings, respectively after conventional or advanced renovations. Under current renovation rates, the carbon footprint reduction would be limited to 3–4% by 2030. Pushing renovation rates to 3%, enables carbon reductions up to 28% by 2030 when combined with advanced renovations. Carbon reductions in the operational stage of buildings are offset by 8–9% due to the impacts of renovation. Using time-adjusted emissions results in higher weight for the renovation stage and slightly lower benefits for renovation
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