1,522 research outputs found

    Synchronous gastric and duodenal metastases from head and neck squamous cell carcinoma: a unique presentation of upper gastrointestinal bleeding.

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    Metastatic disease to the stomach or duodenum is an infrequent diagnosis, and head and neck squamous cell carcinoma (HNSCC) is one of the least common primary malignancies that lead to gastric or duodenal metastases. We report the case of a 65-year-old man with human immunodeficiency virus infection and previously diagnosed HNSCC who presented with melena. The patient had a percutaneous endoscopic gastrostomy tube placed 3 months prior to his presentation. Laboratory testing was significant for normocytic anemia and a digital rectal examination was positive for melena. Esophagogastroduodenoscopy revealed numerous cratered nodules with contact bleeding in the stomach as well as the duodenum that appeared malignant. Biopsies of the gastric and duodenal nodules were positive for p40 and CK 5/6, consistent with metastatic squamous cell carcinoma

    Planning and control in the 19th century ice trade

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    This paper describes selected accounting records of the Tudor Ice Company which were devised to manage and control the far-flung business activities of Frederic Tudor, a 19th century entrepreneur who has been called America\u27s first monopolist. Tudor\u27s business genius lay in developing methods of harvesting, transporting, storing, and marketing commercial quantities of ice taken from New England ponds and shipped to tropical ports around the world. Frederic Tudor employed relatively sophisticated accounting techniques to analyze and control transportation costs and the costs of product shrinkage. He also routinely analyzed and translated foreign currency transactions for his geographically dispersed operations and evaluated the impact of competition on his operations

    Common Causes and The Direction of Causation

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    Is the common cause principle merely one of a set of useful heuristics for discovering causal relations, or is it rather a piece of heavy duty metaphysics, capable of grounding the direction of causation itself? Since the principle was introduced in Reichenbach’s groundbreaking work The Direction of Time (1956), there have been a series of attempts to pursue the latter program—to take the probabilistic relationships constitutive of the principle of the common cause and use them to ground the direction of causation. These attempts have not all explicitly appealed to the principle as originally formulated; it has also appeared in the guise of independence conditions, counterfactual overdetermination, and, in the causal modelling literature, as the causal markov condition. In this paper, I identify a set of difficulties for grounding the asymmetry of causation on the principle and its descendents. The first difficulty, concerning what I call the vertical placement of causation, consists of a tension between considerations that drive towards the macroscopic scale, and considerations that drive towards the microscopic scale—the worry is that these considerations cannot both be comfortably accommodated. The second difficulty consists of a novel potential counterexample to the principle based on the familiar Einstein Podolsky Rosen (EPR) cases in quantum mechanics

    Spiking Neurons Learning Phase Delays

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    Time differences between the two ears are an important cue for animals to azimuthally locate a sound source. The first binaural brainstem nucleus, in mammals the medial superior olive, is generally believed to perform the necessary computations. Its cells are sensitive to variations of interaural time differences of about 10 Îźs. The classical explanation of such a neuronal time-difference tuning is based on the physical concept of delay lines. Recent data, however, are inconsistent with a temporal delay and rather favor a phase delay. By means of a biophysical model we show how spike-timing-dependent synaptic learning explains precise interplay of excitation and inhibition and, hence, accounts for a physical realization of a phase delay

    Exaptation traits for megafaunal Mutualisms as a factor in plant domestication

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    Megafaunal extinctions are recurring events that cause evolutionary ripples, as cascades of secondary extinctions and shifting selective pressures reshape ecosystems. Megafaunal browsers and grazers are major ecosystem engineers, they: keep woody vegetation suppressed; are nitrogen cyclers; and serve as seed dispersers. Most angiosperms possess sets of physiological traits that allow for the fixation of mutualisms with megafauna; some of these traits appear to serve as exaptation (preadaptation) features for farming. As an easily recognized example, fleshy fruits are, an exaptation to agriculture, as they evolved to recruit a non-human disperser. We hypothesize that the traits of rapid annual growth, self-compatibility, heavy investment in reproduction, high plasticity (wide reaction norms), and rapid evolvability were part of an adaptive syndrome for megafaunal seed dispersal. We review the evolutionary importance that megafauna had for crop and weed progenitors and discuss possible ramifications of their extinction on: (1) seed dispersal; (2) population dynamics; and (3) habitat loss. Humans replaced some of the ecological services that had been lost as a result of late Quaternary extinctions and drove rapid evolutionary change resulting in domestication.Introduction Lost Seed-Dispersal Services - Small-Seeded Grains and Legumes - Large Fleshy Fruiting Plants Loss of Herbivory and Disturbance Regimes Plant Domestication - Exaptation Traits Supporting Domestication Anthropogenic Ecosystem Service

    The BBaRTS Healthy Teeth Behaviour Change Programme for preventing dental caries in primary school children: study protocol for a cluster randomised controlled trial

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    Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were madeThis trial is supported by an unrestricted grant from GlaxoSmithKlin
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