4,345 research outputs found

    Oil and the Eastern Front: US Foreign and Military Policy in Iran, 1941-1945

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    Naomi R. Rosenblatt, College \u2709, History Oil and the Eastern Front: US Foreign and Military Policy in Iran, 1941-1945 During World War II, the United States established a military presence in Iran that marked a dramatic change in U.S. involvement in the Middle East. Unlike earlier centuries when Americans traveled to the Middle East primarily as missionaries, merchants, and pilgrims, during WWII, the U.S. government began to establish deep political and economic ties to the region. How did U.S. foreign policy towards Iran develop within the context of a global war? What sort of tensions developed between the State Department\u27s long-term diplomatic goals and the War Department\u27s urgent short-term military aims? Through my research, I hope to illuminate how the United States balanced its own competing interests in Iran: that of ensuring a speedy victory at minimal human and financial cost, while all the while keeping in mind that its military efforts could very well disrupt its long-term diplomatic interests

    Slow Isotope Turnover Rates and Low Discrimination Values in the American Alligator: Implications for Interpretation of Ectotherm Stable Isotope Data

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    Stable isotope analysis has become a standard ecological tool for elucidating feeding relationships of organisms and determining food web structure and connectivity. There remain important questions concerning rates at which stable isotope values are incorporated into tissues (turnover rates) and the change in isotope value between a tissue and a food source (discrimination values). These gaps in our understanding necessitate experimental studies to adequately interpret field data. Tissue turnover rates and discrimination values vary among species and have been investigated in a broad array of taxa. However, little attention has been paid to ectothermic top predators in this regard. We quantified the turnover rates and discrimination values for three tissues (scutes, red blood cells, and plasma) in American alligators (Alligator mississippiensis). Plasma turned over faster than scutes or red blood cells, but turnover rates of all three tissues were very slow in comparison to those in endothermic species. Alligator δ15N discrimination values were surprisingly low in comparison to those of other top predators and varied between experimental and control alligators. The variability of δ15N discrimination values highlights the difficulties in using δ15N to assign absolute and possibly even relative trophic levels in field studies. Our results suggest that interpreting stable isotope data based on parameter estimates from other species can be problematic and that large ectothermic tetrapod tissues may be characterized by unique stable isotope dynamics relative to species occupying lower trophic levels and endothermic tetrapods

    What do alligators eat on golf courses?

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    Urbanization is an ever-increasing threat to wildlife and their natural habitats, yet research has been limited to a small number of taxa and very few large predator species. The American alligator (Alligator mississippiensis) is an apex predator across the southeast U.S. and has surprisingly received minimal attention within urban areas. To investigate the potential effects of land development on alligator trophic ecology, we performed gut content analysis on golf course alligators found on Jekyll Island, Georgia. We then made comparisons with alligators found in more natural areas on Sapelo Island, Georgia. In total, we collected stomach content samples from 25 alligators on Jekyll Island golf courses, of which only one had an empty stomach. Data provided from Sapelo Island consisted of 93 alligators within our alligator size range, of which only one had an empty stomach. While analysis of similarity, non-metric multidimensional scaling, and simplified Morisita index analyses show no significant difference in diets between the two areas (possibly because of a low sample size from Jekyll Island), %IRI values for prey items reveal that there may be functional differences in prey choice or availability. Further land development and increasing human activity may therefore shift diets toward reliance on prey items usually of lesser importance. These trophic effects could possibly lead to local population declines, if paired with habitat degradation or other stressors

    Gene identification for the cblD defect of vitamin B12 metabolism

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    Background Vitamin B12 (cobalamin) is an essential cofactor in several metabolic pathways. Intracellular conversion of cobalamin to its two coenzymes, adenosylcobalamin in mitochondria and methylcobalamin in the cytoplasm, is necessary for the homeostasis of methylmalonic acid and homocysteine. Nine defects of intracellular cobalamin metabolism have been defined by means of somatic complementation analysis. One of these defects, the cblD defect, can cause isolated methylmalonic aciduria, isolated homocystinuria, or both. Affected persons present with multisystem clinical abnormalities, including developmental, hematologic, neurologic, and metabolic findings. The gene responsible for the cblD defect has not been identified. Methods We studied seven patients with the cblD defect, and skin fibroblasts from each were investigated in cell culture. Microcell-mediated chromosome transfer and refined genetic mapping were used to localize the responsible gene. This gene was transfected into cblD fibroblasts to test for the rescue of adenosylcobalamin and methylcobalamin synthesis. Results The cblD gene was localized to human chromosome 2q23.2, and a candidate gene, designated MMADHC (methylmalonic aciduria, cblD type, and homocystinuria), was identified in this region. Transfection of wild-type MMADHC rescued the cellular phenotype, and the functional importance of mutant alleles was shown by means of transfection with mutant constructs. The predicted MMADHC protein has sequence homology with a bacterial ATP-binding cassette transporter and contains a putative cobalamin binding motif and a putative mitochondrial targeting sequence. Conclusions Mutations in a gene we designated MMADHC are responsible for the cblD defect in vitamin B12 metabolism. Various mutations are associated with each of the three biochemical phenotypes of the disorder

    Behavioral assay procedures for transfer of learned behavior by brain extracts.

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    Analysis of Models for Decentralized and Collaborative AI on Blockchain

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    Machine learning has recently enabled large advances in artificial intelligence, but these results can be highly centralized. The large datasets required are generally proprietary; predictions are often sold on a per-query basis; and published models can quickly become out of date without effort to acquire more data and maintain them. Published proposals to provide models and data for free for certain tasks include Microsoft Research's Decentralized and Collaborative AI on Blockchain. The framework allows participants to collaboratively build a dataset and use smart contracts to share a continuously updated model on a public blockchain. The initial proposal gave an overview of the framework omitting many details of the models used and the incentive mechanisms in real world scenarios. In this work, we evaluate the use of several models and configurations in order to propose best practices when using the Self-Assessment incentive mechanism so that models can remain accurate and well-intended participants that submit correct data have the chance to profit. We have analyzed simulations for each of three models: Perceptron, Na\"ive Bayes, and a Nearest Centroid Classifier, with three different datasets: predicting a sport with user activity from Endomondo, sentiment analysis on movie reviews from IMDB, and determining if a news article is fake. We compare several factors for each dataset when models are hosted in smart contracts on a public blockchain: their accuracy over time, balances of a good and bad user, and transaction costs (or gas) for deploying, updating, collecting refunds, and collecting rewards. A free and open source implementation for the Ethereum blockchain and simulations written in Python is provided at https://github.com/microsoft/0xDeCA10B. This version has updated gas costs using newer optimizations written after the original publication.Comment: Accepted to ICBC 202

    Online learning via dynamic reranking for Computer Assisted Translation

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    New techniques for online adaptation in computer assisted translation are explored and compared to previously existing approaches. Under the online adaptation paradigm, the translation system needs to adapt itself to real-world changing scenarios, where training and tuning may only take place once, when the system is set-up for the first time. For this purpose, post-edit information, as described by a given quality measure, is used as valuable feedback within a dynamic reranking algorithm. Two possible approaches are presented and evaluated. The first one relies on the well-known perceptron algorithm, whereas the second one is a novel approach using the Ridge regression in order to compute the optimum scaling factors within a state-of-the-art SMT system. Experimental results show that such algorithms are able to improve translation quality by learning from the errors produced by the system on a sentence-by-sentence basis.This paper is based upon work supported by the EC (FEDER/FSE) and the Spanish MICINN under projects MIPRCV “Consolider Ingenio 2010” (CSD2007-00018) and iTrans2 (TIN2009-14511). Also supported by the Spanish MITyC under the erudito.com (TSI-020110-2009-439) project, by the Generalitat Valenciana under grant Prometeo/2009/014 and scholarship GV/2010/067 and by the UPV under grant 20091027Martínez Gómez, P.; Sanchis Trilles, G.; Casacuberta Nolla, F. (2011). Online learning via dynamic reranking for Computer Assisted Translation. En Computational Linguistics and Intelligent Text Processing. Springer Verlag (Germany). 6609:93-105. https://doi.org/10.1007/978-3-642-19437-5_8S931056609Brown, P., Pietra, S.D., Pietra, V.D., Mercer, R.: The mathematics of machine translation. 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In: Proc. of EACL 2003, pp. 387–393 (2003)Sanchis-Trilles, G., Casacuberta, F.: Log-linear weight optimisation via bayesian adaptation in statistical machine translation. In: Proceedings of COLING 2010, Beijing, China (2010)Callison-Burch, C., Bannard, C., Schroeder, J.: Improving statistical translation through editing. In: Proc. of 9th EAMT Workshop Broadening Horizons of Machine Translation and its Applications, Malta (2004)Barrachina, S., et al.: Statistical approaches to computer-assisted translation. Computational Linguistics 35, 3–28 (2009)Casacuberta, F., et al.: Human interaction for high quality machine translation. Communications of the ACM 52, 135–138 (2009)Ortiz-Martínez, D., García-Varea, I., Casacuberta, F.: Online learning for interactive statistical machine translation. In: Proceedings of NAACL HLT, Los Angeles (2010)España-Bonet, C., Màrquez, L.: Robust estimation of feature weights in statistical machine translation. 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    P619Role of Toll-like receptor 5 in the development of post-myocardial infarction inflammation

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    Background: Inflammatory processes play a key role in the pathophysiology of myocardial infarction (MI). Genetic deletion of toll-like recpetors (TLRs), especially TLR2 and TLR4 have shown protective role in murine models of MI. The role of other TLRs remains unknown. We have previously shown that cardiomyocytes express TLR5 and that the ligand of TLR5, flagellin, activates the NF-kappaB and MAPK pathways in cardiomyocytes. We also have shown that injection of flagellin induces acute systolic dysfunction in vivo in mice. Aim: Determine the role of TLR5 in the development of post-MI inflammation. Methods: A murine model of myocardial infarction was done by a 30 minutes ligation of the left anterior descending coronary artery followed by 2 hours of reperfusion. Infarct size was measured by standard Evans blue/TTC staining. Plasma creatine kinase (CK) was quantified as a read out of myocardial necrosis. Tissue and plasma cytokines (MIP-2, MCP-1, IL-6) were quantified by ELISA. To determine the extent of tissue lipid peroxidation we used malondialdehyde and 4-hydroxynonenal-HIS adduct assays. Tissue protein oxidation was tested by protein carbonyl ELISA kit. Phosphorylation of MAPK was analyzed by western blot. Results: Genetic suppression of TLR5 induced a significant increase of myocardial infarct size and plasma CK, of biochemical markers of myocardial oxidative stress, and cytokine levels in the heart and the plasma after MI. These effects were associated with a marked enhancement of p38 phosphorylation in the heart from TLR5 KO mice. Conclusion: TLR5 protects from acute myocardial injury and reduces local and systemic inflammation during myocardial infarction. The mechanisms may involve reduced p38 signaling, decreased oxidative stress and attenuated cytokine expression. Research supported by the Swiss National Science Foundation, Grant n° 310030_135394/

    P90Necrotic cardiomyocytes release soluble pro-inflammatory molecule(s) inducing il1r/myd88-dependent inflammatory responses in cardiac fibroblasts

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    Background: Inflammation comes out to be a critical biological process in the pathophysiology of myocardial infarction (MI). We hypothesize that this inflammation is triggered by necrotic cardiomyocytes (Cmc) that release a set of endogenous molecules (DAMPs: danger-associated molecular patterns) activating inflammatory responses in cardiac fibroblasts. Aim: Analyze in vitro the immune activation of cardiac fibroblasts exposed to necrotic Cmc conditioned media. Methods: Primary neonatal murine cardiac fibroblasts and Cmc were obtained by digestion of neonatal hearts and differential plating technique allowing a selection for cardiomyocytes and cardiac fibroblasts. Cmc were killed by necrotic stimuli including oxidants (hydrogen peroxide) and mechanic stresses (freeze-thaw). Necrosis was assessed using Hoechst/PI stainings. Fibroblasts were exposed to necrotic Cmc conditioned media and mRNA expression of inflammatory genes was measured by real-time PCR and ELISA. Activation of signaling pathways was analyzed by western blot. We used cardiac cells from Myd88-/-, Trif-/- and Nlrp3-/- animals to evaluate the contribution of TLRs/IL1-R and NLRP3 inflammasome in the sensing of necrotic DAMPs. Results: mRNA expression of chemokines such as MCP-1, MIP-2 and IP-10 were induced in fibroblasts exposed to necrotic Cmc conditioned media. Alternatively, fibroblasts exposed to necrotic fibroblasts conditioned media showed a lower increase in mRNA expression of these chemokines. In addition, in fibroblasts from Myd88-/- mice, response to Cmc conditioned media was fully abrogated whereas no difference was observed in Trif-/- and Nlrp3-/- fibroblasts. Conclusion: Cardiac fibroblasts are able to produce a rapid and specific inflammatory response to necrotic Cmc conditioned media involving the expression of neutrophil and monocyte chemoattractants. The dependence on MyD88 adaptor protein strongly suggests that this response relies on TLR/IL-1R signaling. These results engage cardiac fibroblasts as key players in post-MI inflammatory responses as they are able to sense DAMPs from necrotic Cmc and possibly recruit inflammatory cells. Research supported by the Swiss National Science Foundation, Grant n° 310030_135394/
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