2,089 research outputs found

    Police and Older Persons: Criteria Developed to Assess Training Materials, Methods

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    This article as revised was published as Johnson, Knowlton W.; Beirnard, Charles A.; & Stiles, Stephen R. (1981). "Police and Older Persons: Criteria Developed to Assess Training Materials, Methods." Training Aids Digest 6(11), November 1981.In what ways do law enforcement personnel and agencies use knowledge about the elderly? This article presents the findings of a recent study conducted by the International Training Research and Evaluation Council on how law enforcement trainees make use of the knowledge they gained through training materials developed by the National Retired Teachers Association/American Association of Retired Persons.[Introduction] / Different Types of Knowledge Use / The Study / Knowledge Into Practice: Some Implication

    Mechanical Translation

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    Contains reports on three research projects.National Science Foundation (Grant G-24047

    Terrigenous Fe input and biogenic sedimentation in the glacial and interglacial equatorial Pacific Ocean

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    Many ocean regions important to the global carbon budget, including the equatorial Pacific Ocean, have low chlorophyll concentrations despite high levels of conventional nutrients. Iron may instead be the limiting nutrient, and elevated input of terrigenous Fe during windy glacial episodes has been hypothesized to stimulate oceanic productivity through time and thus regulate the oceanic and atmospheric CO2 balance. To test whether particulate Fe input is related to the accumulation of biogenic matter in one important low chlorophyll‐high nutrient area, that is, the equatorial Pacific Ocean, we present results from a suite of sediment cores that collectively record biogenic deposition through the last six glacial‐interglacial cycles (∼600,000 years). Our data set includes new chemical data on total Fe, terrigenous, and biogenic components in three cores as well as previously published mineralogic records of eolian input to the region. Chemical, spectral, and stratigraphic analysis indicates that (1) terrigenous input to the region shows no consistent pattern of either glacial or interglacial maxima, (2) the accumulation of particulate Fe is closely related to the accumulation of terrigenous matter (linear r2 = 0.81–0.98), (3) there are no coherent spectral relationships between Fe input and glacial periodicity (i.e., δ18O) in any of the orbital frequency bands, (4) the linear and cross‐spectral correlations between Fe or eolian input and CaCO3 concentration are most commonly the strongest observed relationships between Fe and any biogenic component, yet indicate a largely inverse pattern, with higher Fe being associated with low CaCO3, (5) there is no consistent linear r2 correlation or spectral coherence between the accumulation of Fe and that of CaCO3, Corg, or opal. Thus in total there is no relationship between terrigenous Fe input and sedimentary sequestering of carbon. Additionally, although we cannot specifically address the potential for changes in solubility of the terrigenous fraction that may be driven by a terrigenous compositional change, the Fe/Ti ratio (which monitors first‐order mineralogic changes) records only slight variations that also are linearly and spectrally unrelated to glacial periodicity, the bulk Fe flux, and the accumulation of any biogenic component. Finally, we find that the paleoceanographic flux of Fe is several order‐of‐magnitudes larger than modern observations of eolian Fe input, suggesting that the long‐term importance of Fe input by dust storms (which deliver Fe on the order of the sedimentary burial) may be underestimated. The removal of particulate terrigenous Fe from the recently discovered source within the Equatorial Undercurrent, however, remains unquantified and may also prove significant

    The Behavior of Granular Materials under Cyclic Shear

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    The design and development of a parallel plate shear cell for the study of large scale shear flows in granular materials is presented. The parallel plate geometry allows for shear studies without the effects of curvature found in the more common Couette experiments. A system of independently movable slats creates a well with side walls that deform in response to the motions of grains within the pack. This allows for true parallel plate shear with minimal interference from the containing geometry. The motions of the side walls also allow for a direct measurement of the velocity profile across the granular pack. Results are presented for applying this system to the study of transients in granular shear and for shear-induced crystallization. Initial shear profiles are found to vary from packing to packing, ranging from a linear profile across the entire system to an exponential decay with a width of approximately 6 bead diameters. As the system is sheared, the velocity profile becomes much sharper, resembling an exponential decay with a width of roughly 3 bead diameters. Further shearing produces velocity profiles which can no longer be fit to an exponential decay, but are better represented as a Gaussian decay or error function profile. Cyclic shear is found to produce large scale ordering of the granular pack, which has a profound impact on the shear profile. There exist periods of time in which there is slipping between layers as well as periods of time in which the layered particles lock together resulting in very little relative motion.Comment: 10 pages including 12 figure

    Decoding Developmental Differences and Individual Variability in Response Inhibition Through Predictive Analyses Across Individuals

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    Response inhibition is thought to improve throughout childhood and into adulthood. Despite the relationship between age and the ability to stop ongoing behavior, questions remain regarding whether these age-related changes reflect improvements in response inhibition or in other factors that contribute to response performance variability. Functional neuroimaging data shows age-related changes in neural activity during response inhibition. While traditional methods of exploring neuroimaging data are limited to determining correlational relationships, newer methods can determine predictability and can begin to answer these questions. Therefore, the goal of the current study was to determine which aspects of neural function predict individual differences in age, inhibitory function, response speed, and response time variability. We administered a stop-signal task requiring rapid inhibition of ongoing motor responses to healthy participants aged 9–30. We conducted a standard analysis using GLM and a predictive analysis using high-dimensional regression methods. During successful response inhibition we found regions typically involved in motor control, such as the ACC and striatum, that were correlated with either age, response inhibition (as indexed by stop-signal reaction time; SSRT), response speed, or response time variability. However, when examining which variables neural data could predict, we found that age and SSRT, but not speed or variability of response execution, were predicted by neural activity during successful response inhibition. This predictive relationship provides novel evidence that developmental differences and individual differences in response inhibition are related specifically to inhibitory processes. More generally, this study demonstrates a new approach to identifying the neurocognitive bases of individual differences

    Decoding Continuous Variables from Neuroimaging Data: Basic and Clinical Applications

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    The application of statistical machine learning techniques to neuroimaging data has allowed researchers to decode the cognitive and disease states of participants. The majority of studies using these techniques have focused on pattern classification to decode the type of object a participant is viewing, the type of cognitive task a participant is completing, or the disease state of a participant's brain. However, an emerging body of literature is extending these classification studies to the decoding of values of continuous variables (such as age, cognitive characteristics, or neuropsychological state) using high-dimensional regression methods. This review details the methods used in such analyses and describes recent results. We provide specific examples of studies which have used this approach to answer novel questions about age and cognitive and disease states. We conclude that while there is still much to learn about these methods, they provide useful information about the relationship between neural activity and age, cognitive state, and disease state, which could not have been obtained using traditional univariate analytical methods

    Postglacial expansion of the arctic keystone copepod calanus glacialis

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    Calanus glacialis, a major contributor to zooplankton biomass in the Arctic shelf seas, is a key link between primary production and higher trophic levels that may be sensitive to climate warming. The aim of this study was to explore genetic variation in contemporary populations of this species to infer possible changes during the Quaternary period, and to assess its population structure in both space and time. Calanus glacialis was sampled in the fjords of Spitsbergen (Hornsund and Kongsfjorden) in 2003, 2004, 2006, 2009 and 2012. The sequence of a mitochondrial marker, belonging to the ND5 gene, selected for the study was 1249 base pairs long and distinguished 75 unique haplotypes among 140 individuals that formed three main clades. There was no detectable pattern in the distribution of haplotypes by geographic distance or over time. Interestingly, a Bayesian skyline plot suggested that a 1000-fold increase in population size occurred approximately 10,000 years before present, suggesting a species expansion after the Last Glacial Maximum.GAME from the National Science Centre, the Polish Ministry of Science and Higher Education Iuventus Plus [IP2014 050573]; FCT-PT [CCMAR/Multi/04326/2013]; [2011/03/B/NZ8/02876

    Radiotherapy in the treatment of gastrointestinal stromal tumor

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    Gastrointestinal stromal tumors (GISTs) are uncommon mesenchymal tumors of the gastrointestinal tract. Up to one-third of GISTs are malignant with a high rate of metastasis. Surgical resection is the mainstay of care for patients with resectable disease. Imatinib mesylate, a selective tyrosine kinase inhibitor, is the current standard of care for GISTs that cannot be completely resected or in cases of metastatic GIST. Although often overlooked, radiation therapy is a viable option for select patients with GIST. We report the case of a patient with unresectable GIST who was treated with local radiotherapy and achieved long-term response. We also present a review of the literature regarding the use of radiotherapy in the treatment of GIST. GIST has been shown to be a radiosensitive tumor. Radiotherapy can offer long-term local control and should be considered in the adjuvant or palliative setting. The role of radiotherapy delivered concurrently with imatinib in the treatment of GIST may warrant further investigation

    Frontal and Parietal Contributions to Probabilistic Association Learning

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    Neuroimaging studies have shown both dorsolateral prefrontal (DLPFC) and inferior parietal cortex (iPARC) activation during probabilistic association learning. Whether these cortical brain regions are necessary for probabilistic association learning is presently unknown. Participants' ability to acquire probabilistic associations was assessed during disruptive 1 Hz repetitive transcranial magnetic stimulation (rTMS) of the left DLPFC, left iPARC, and sham using a crossover single-blind design. On subsequent sessions, performance improved relative to baseline except during DLPFC rTMS that disrupted the early acquisition beneficial effect of prior exposure. A second experiment examining rTMS effects on task-naive participants showed that neither DLPFC rTMS nor sham influenced naive acquisition of probabilistic associations. A third experiment examining consecutive administration of the probabilistic association learning test revealed early trial interference from previous exposure to different probability schedules. These experiments, showing disrupted acquisition of probabilistic associations by rTMS only during subsequent sessions with an intervening night's sleep, suggest that the DLPFC may facilitate early access to learned strategies or prior task-related memories via consolidation. Although neuroimaging studies implicate DLPFC and iPARC in probabilistic association learning, the present findings suggest that early acquisition of the probabilistic cue-outcome associations in task-naive participants is not dependent on either region
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