1,204 research outputs found

    Murder at Harvard Mobile

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    The MURDER AT HARVARD MOBILE project (wt) will re-version a well-known N.E.H.-funded historical documentary about a notorious 1849 Boston murder into the basis of a 40-minute audio/video walking tour that will be accessed through a hand-held device similar to the iPhone. By using the compelling story of a famous crime as its narrative spine, this project will provide student groups and cultural tourists with a layered look at the social and cultural history of some of Boston's most significant downtown areas while it provides a road map for use of open source Mobile Narrative Software. The project will start in September, 2008 and end in February, 2009

    Algebraic invariants, mutation, and commensurability of link complements

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    We construct a family of hyperbolic link complements by gluing tangles along totally geodesic four-punctured spheres, then investigate the commensurability relation among its members. Those with different volume are incommensurable, distinguished by their scissors congruence classes. Mutation produces arbitrarily large finite subfamilies of nonisometric manifolds with the same volume and scissors congruence class. Depending on the choice of mutation, these manifolds may be commensurable or incommensurable, distinguished in the latter case by cusp parameters. All have trace field Q(i,\sqrt{2}), but some have integral traces while others do not.Comment: Minor changes following referee's suggestion

    First Records for \u3ci\u3eAeshna Sitchensis\u3c/i\u3e (Odonata: Aeshnidae) and \u3ci\u3eEnallagma Clausum\u3c/i\u3e (Odonata: Coenagrionidae), and a Northwestern Record for the State-Endangered \u3ci\u3eSomatochlora Incurvata\u3c/i\u3e (Odonata: Corduliidae) in Wisconsin

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    While surveying for Odonata in coastal peatlands and associated shoreline areas adjacent to Lake Superior in Wisconsin, we documented populations of two new state record species, the zig-zag darner (Aeshna sitchensis Hagen) and the alkali bluet (Enallagma clausum Morse). We also located a robust population of the state-endangered incurvate emerald (Somatochlora incurvata Walker) at the northwestern edge of the known range of this species. Adults and exuviae of A. sitchensis and S. incurvata were found at an insular fen on Stockton Island, Ashland County, within the Apostle Islands National Lakeshore (AINL). Breeding of both species had occurred in areas of the fen where small pools had dried by summer. Additionally, a single adult male A. sitchensis was collected in the City of Superior in Douglas County. Adult E. clausum were found at two sites: on the Lake Superior beach near the mouth of the Sand River within the AINL in Bayfield County, and along the northeast shore of Allouez Bay in the City of Superior in Douglas County

    Strategy & Force Planning: The Case of the Persian Gulf

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    Truth and Belief: Case Studies in Conceptual Engineering

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    Although the concepts of truth and belief are fundamental in philosophy, in recent years they have come under attack from various quarters. I argue that philosophers have been too quick to find these concepts problematic and in need of being replaced. For example, the Liar Paradox is sometimes taken to show that the concept of truth is inconsistent, and thus unsuitable for rigorous inquiry. But I develop a solution that gives a consistent account of this concept, allowing us to retain it in spite of the paradox. I argue that when the word ‘true’ occurs in such a sentence, it undergoes a one-off aberration in its reference, failing to refer to truth. Thus, Liar sentences and their kin fail to say what they pre-theoretically appear to say. However, there is no need to conclude that these sentences are meaningless; rather, I illustrate how these sentences come very close to saying what they appear to say, in spite of the aberrations they witness. As with the concept of truth, intentional concepts like those of belief, meaning, and reference have been subject to skepticism and attempts at excision. I show that the content of the claim that the use of intentional concepts can be eliminated from scientific explanations depends on broader issues about how one conceives of explanations. Then I argue that intentional concepts, in particular the concept of belief, play an ineliminable role in the explanation of behavior: when we learn what someone believes, we get some information about how she would react to a variety of possible scenarios. This information that is useful in everyday life, and would be important in a science whose aim was to improve on our folk-psychological explanations. But so far, explanations that avoid talk of beliefs have failed to replicate this distinctive kind of informativeness. Thus, we have reason to think that belief-attributions are indispensable when it comes to explaining people’s behaviors, and so we have reason to retain the notion of belief

    Comparing the cumulative pain patients experience waiting for knee arthroplasty to their postoperative pain

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    Introduction: Reduction of pain is a major goal of anesthesiologists treating patients undergoing knee arthroplasty. This has been achieved traditionally through the use of regional analgesia. Although these techniques decrease postoperative pain, they inherently do not affect the longstanding pain patients experience as they wait for surgery. Our objectives were to quantify: 1) the decrease in pain achieved by surgical joint replacement; and 2) the decrease in postoperative pain achievable through femoral nerve blocks versus opioids. From a systems-based perspective, we wanted to determine how much reduction in waiting time before surgery would be necessary to achieve an equal cumulative pain decrease (i.e, pain x duration of pain) as that afforded by regional techniques in the immediate postoperative period. Materials and methods: A systematic review using PubMed was performed to obtain: 1) articles reporting preoperative pain scores for patients awaiting joint arthroplasty; 2) articles with knee arthroplasty patients who received femoral nerve blocks; and 3) articles providing duration on joint arthroplasty waiting lists. Cumulative pain was assessed by the area under the response curve of pain scores vs. time, a methodology that is simple and valid. This was calculated by multiplying mean pain scores by the duration of pain. Results: The decrease in knee pain subsequent to arthroplasty (6.4/10 vs. 2.9/10) is similar to the decrease in pain afforded by femoral nerve blocks for knee arthroplasty (4.7/10 vs. 2.0/10). Waiting times in many countries exceed 3 months. A decrease in waiting time by about 2 days results in a decrease in the area under the curve of Conclusion: Reducing waiting time for knee arthroplasty decreases total pain experienced by patients and is one systems-based approach that anesthesiologists could take to relieve pain. Further studies are needed to evaluate how best to accomplish this goal

    The outlier paradox: The role of iterative ensemble coding in discounting outliers

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    Ensemble perception—the encoding of objects by their group properties—is known to be resistant to outlier noise. However, this resistance is somewhat paradoxical: how can the visual system determine which stimuli are outliers without already having derived statistical properties of the ensemble? A simple solution would be that ensemble perception is not a simple, one-step process; instead, outliers are detected through iterative computations that identify items with high deviance from the mean and reduce their weight in the representation over time. Here we tested this hypothesis. In Experiment 1, we found evidence that outliers are discounted from mean orientation judgments, extending previous results from ensemble face perception. In Experiment 2, we tested the timing of outlier rejection by having participants perform speeded judgments of sets with or without outliers. We observed significant increases in reaction time (RT) when outliers were present, but a decrease compared to no-outlier sets of matched range suggesting that range alone did not drive RTs. In Experiment 3 we tested the timing by which outlier noise reduces over time. We presented sets for variable exposure durations and found that noise decreases linearly over time. Altogether these results suggest that ensemble representations are optimized through iterative computations aimed at reducing noise. The finding that ensemble perception is an iterative process provides a useful framework for understanding contextual effects on ensemble perception

    Climate change and extreme weather events - Implications for food production, plant diseases, and pests

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    Current and future energy use from burning of fossil fuels and clearing of forests for cultivation can have profound effects on the global environment, agriculture, and the availability of low-cost, high-quality food for humans. Individual farmers and consumers are expected to be affected by changes in global and regional climate. The agricultural sector in both developing and developed areas needs to understand what is at stake and to prepare for the potential for change wisely. Despite tremendous improvements in technology and crop yield potential, food production remains highly dependent on climate, because solar radiation, temperature, and precipitation are the main drivers of crop growth. Plant diseases and pest infestations, as well as the supply of and demand for irrigation water are influenced by climate. For example, in recent decades, the persistent drought in the Sahelian region of Africa has caused continuing deterioration of food production; the 1988 Midwest drought led to a 30% reduction in U.S. corn production and cost taxpayers $3 billion in direct relief payments to farmers and, weather anomalies associated with the 1997-98 El Niño affected agriculture adversely in Nordeste, Brazil and Indonesia. Earlier in the century, the 1930s U.S. Southern Great Plains drought caused some 200,000 farm bankruptcies in the Dust Bowl; yields of wheat and corn were reduced by as much as 50%
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