153 research outputs found

    Integrated Intermodal Network Design with Nonlinear Inter-Hub Movement Costs

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    In this research, transportation mode and load route selection problems are integrated with the hub location problem in a single mathematical formulation to find the optimal design of intermodal transportation networks. Economies of scale are modeled utilizing a stepwise function that relates the per container transportation cost to the amount of flow between two nodes. A heuristic method combining a genetic algorithm and the shortest path algorithm was developed to solve this integrated planning problem. Computational experiments were completed to evaluate the performance of the proposed heuristic for different problem instances. At the end, conclusions are presented and future research directions are discussed

    Joint perception: gaze and social context

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    We found that the way people looked at images was influenced by their belief that others were looking too. If participants believed that an unseen other person was also looking at what they could see, it shifted the balance of their gaze between negative and positive images. The direction of this shift depended upon whether participants thought that later they would be compared against the other person or would be collaborating with them. Changes in the social context influenced both gaze and memory processes, and were not due just to participants' belief that they are looking at the same images, but also to the belief that they are doing the same task. We believe that the phenomenon of joint perception reveals the pervasive and subtle effect of social context upon cognitive and perceptual processes

    Psychotropic Agents Poisoning: Analysis of Cases Reported to Shahid Beheshti Drug and Poison Information Center

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    Background: Antidepressants, antipsychotics and benzodiazepines overdose events are the most reported poisoning each year from Shahid Beheshti Drug and Poison Information Center (DPIC) (a branch of Iran Drug and Poison Information Center in Tehran), which clearly shows the necessity of providing prevention program and instruction plan in taking psychotropic agents.Methods: This survey was a descriptive retrospective study by reviewing 390 reported phone calls from Shahid Beheshti Drug and Poison Information Center (DPIC), in Tehran, through 2010 to 2012.Results: 390 reported cases of psychotropic agents including overdoses, medical errors such as extra dose, accidental exposure of medications, especially in children, cases of suicide, and intentional use (were) recorded. The main causes of poisoning calls to the DPIC, were included intentional and suicidal actions (40%), accidental events (27%), drug abuse (26%) and, medical errors (7%), respectively. Up to 50% of calls were about benzodiazepines (BZD) poisoning and the most adverse effects were Central Nervous System (CNS) effects followed by gastrointestinal side effects.Conclusion: According to the results, in order to achieve the proper effect of psychotropic agents and preventing related poisoning, providing pharmaceutical services and awareness of patients are necessary. It should be about the therapeutic effects and side effects of their medications by pharmacists and poison centers and limiting the accessibility of patients to large amounts of these medications by regulatory organizations

    Accuracy of rapid ultrasound in shock (RUSH) exam for diagnosis of shock in critically Ill patients

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    Background: Rapid ultrasound in shock (RUSH) is the most recent emergency ultrasound protocol, designed to help clinicians better recognize distinctive shock etiologies in a shorter time frame. Objectives: In this study, we evaluated the accuracy of the RUSH protocol, performed by an emergency physician or radiologist, in predicting the type of shock in critical patients. Patients and Methods: An emergency physician or radiologist performed the RUSH protocol for all patients with shock status at the emergency department. All patients were closely followed to determine their final clinical diagnosis. The agreement between the initial impression provided by RUSH and the final diagnosis was investigated by calculating the Kappa index. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of RUSH for diagnosis of each case. Results: We performed RUSH on 77 patients. Kappa index was 0.71 (P Value = 0.000), reflecting acceptable general agreement between initial impression and final diagnosis. For hypovolemic, cardiogenic and obstructive shock, the protocol had an NPV above 97 yet it had a lower PPV. For shock with distributive or mixed etiology, RUSH showed a PPV of 100 but it had low sensitivity. Subgroup analysis showed a similar Kappa index for the emergency physician and radiologist (0.70 and 0.73, respectively) in performing rush. Conclusions: This study highlights the role of the RUSH exam performed by an emergency physician, to make a rapid and reliable diagnosis of shock etiology, especially in order to rule out obstructive, cardiogenic and hypovolemic shock types in initial exam of shock patients. Copyright © 2015, Trauma Monthly

    Exploring Mechanisms of Hydration and Carbonation of MgO and Mg(OH)2 in Reactive Magnesium Oxide-based Cements

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    Reactive magnesium oxide (MgO)-based cement (RMC) can play a key role in carbon capture processes. However, knowledge on the driving forces that control the degree of carbonation and hydration and rate of reactions in this system remains limited. In this work, density functional theory-based simulations are used to investigate the physical nature of the reactions taking place during the fabrication of RMCs under ambient conditions. Parametric indicators such as adsorption energies, charge transfer, electron localization function, adsorption/dissociation energy barriers and the mechanisms of interaction of H2O and CO2 molecules with MgO and brucite (Mg(OH)2) clusters are considered. The following hydration and carbonation interactions relevant to RMCs are evaluated i) carbonation of MgO, ii) hydration of MgO, carbonation of hydrated MgO, iii) carbonation of Mg(OH)2, iv) hydration of Mg(OH)2 and v) hydration of carbonated Mg(OH)2. A comparison of the energy barriers and reaction pathways of these mechanisms shows that the carbonation of MgO is hindered by presence of H2O molecules, while the carbonation of Mg(OH)2 is hindered by the formation of initial carbonate and hydrate layers as well as presence of excessed H2O molecules. To compare these finding to bulk mineral surfaces, the interactions of the CO2 and H2O molecules with the MgO(001) and Mg(OH)2 (001) surfaces are studied. Therefore, this work presents deep insights into the physical nature of the reactions and the mechanisms involved in hydrated magnesium carbonates production that can be beneficial for its development

    Lacrimal gland adenoma in a sheep

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    The lacrimal gland is a diamond-shaped, tubuloalveolar gland that secretes the serous component of tears. A four-year-old female crossbreed sheep suffering from left eye protrusion was referred to a Veterinary Hospital. Ophthalmic examination revealed epiphora, superficial ulcerative keratitis, cor-neal edema and neovascularisation. Moreover, ultrasound examination showed a large heterogeneous mass with variable reflectivity in the intraconal and extraconal spaces. Grossly, a 2.5×1.5×0.5 cm oval firm grayish mass was observed. Histopathologically, the mass was composed mainly by tubules with two cell types including cuboidal luminal epithelial cells and peripheral myoepithelial cells. The tubular structures were separated by proliferating myoepithelial cells. Mitotic figures, cellular pleomorphism and atypia were not seen. Immunohistochemically, most of the luminal epithelial cells showed an immunopositive reaction with a cytokeratin (AE1/AE3) marker. On the basis of these findings, the mass was diagnosed as a lacrimal gland adenoma
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