251 research outputs found

    Protein palmitoylation plays an important role in Trichomonas vaginalis adherence

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    The flagellated protozoan parasite Trichomonas vaginalis is the etiologic agent of trichomoniasis, the most common non-viral sexually transmitted infection worldwide. As an obligate extracellular pathogen, adherence to epithelial cells is critical for parasite survival within the human host and a better understanding of this process is a prerequisite for the development of therapies to combat infection. In this sense, recent work has shown S-acylation as a key modification that regulates pathogenesis in different protozoan parasites. However, there are no reports indicating whether this post-translational modification is a mechanism operating in T. vaginalis. In order to study the extent and function of S-acylation in T. vaginalis biology, we undertook a proteomic study to profile the full scope of S-acylated proteins in this parasite and reported the identification of 363 proteins involved in a variety of biological processes such as protein transport, pathogenesis related and signaling, among others. Importantly, treatment of parasites with the palmitoylation inhibitor 2-bromopalmitate causes a significant decrease in parasite: Parasite aggregation as well as adherence to host cells suggesting that palmitoylation could be modifying proteins that are key regulators of Trichomonas vaginalis pathogenesis.Fil: Nievas, Yésica Romina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); ArgentinaFil: Vashisht, Ajay A.. University of California; Estados UnidosFil: Corvi, Maria Martha. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); ArgentinaFil: Metz, Sebastián Darío. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); ArgentinaFil: Johnson, Patricia J. University of California; Estados UnidosFil: Wohlschlegel, James A.. University of California; Estados UnidosFil: de Miguel, Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); Argentin

    Text pre-processing tool to increase the exactness of experimental results in summarization solutions

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    For years, and nowadays even more because of the ease of access to information, countless scientific documents that cover all branches of human knowledge are generated. These documents, consisting mostly of text, are stored in digital libraries that are increasingly consenting access and manipulation. This has allowed these repositories of documents to be used for research work of great interest, particularly those related to evaluation of automatic summaries through experimentation. In this area of computer science, the experimental results of many of the published works are obtained using document collections, some known and others not so much, but without specifying all the special considerations to achieve said results. This produces an unfair competition in the realization of experiments when comparing results and does not allow to be objective in the obtained conclusions. This paper presents a text document manipulation tool to increase the exactness of results when obtaining, evaluating and comparing automatic summaries from different corpora. This work has been motivated by the need to have a tool that allows to process documents, split their content properly and make sure that each text snippet does not lose its contextual information. Applying the model proposed to a set of free-access scientific papers has been successful.XV Workshop Bases de Datos y Minería de Datos (WBDDM)Red de Universidades con Carreras en Informática (RedUNCI

    Text pre-processing tool to increase the exactness of experimental results in summarization solutions

    Get PDF
    For years, and nowadays even more because of the ease of access to information, countless scientific documents that cover all branches of human knowledge are generated. These documents, consisting mostly of text, are stored in digital libraries that are increasingly consenting access and manipulation. This has allowed these repositories of documents to be used for research work of great interest, particularly those related to evaluation of automatic summaries through experimentation. In this area of computer science, the experimental results of many of the published works are obtained using document collections, some known and others not so much, but without specifying all the special considerations to achieve said results. This produces an unfair competition in the realization of experiments when comparing results and does not allow to be objective in the obtained conclusions. This paper presents a text document manipulation tool to increase the exactness of results when obtaining, evaluating and comparing automatic summaries from different corpora. This work has been motivated by the need to have a tool that allows to process documents, split their content properly and make sure that each text snippet does not lose its contextual information. Applying the model proposed to a set of free-access scientific papers has been successful.XV Workshop Bases de Datos y Minería de Datos (WBDDM)Red de Universidades con Carreras en Informática (RedUNCI

    Parity Violation in Neutron Resonances in 107,109Ag

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    Parity nonconservation (PNC) was studied in p-wave resonances in Ag by measuring the helicity dependence of the neutron total cross section. Transmission measurements on natural Ag were performed in the energy range 32 to 422 eV with the time-of-flight method at the Manuel Lujan Neutron Scattering Center at Los Alamos National Laboratory. A total of 15 p-wave neutron resonances were studied in 107Ag and ninep-wave resonances in 109Ag. Statistically significant asymmetries were observed for eight resonances in 107Ag and for four resonances in109Ag. An analysis treating the PNC matrix elements as random variables yields a weak spreading width of Γw=(2.67-1.21+2.65)×10-7 eV for107Ag and Γw=(1.30-0.74+2.49)×10-7 eV for 109Ag

    Spin measurements for 147Sm+n resonances: Further evidence for non-statistical effects

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    We have determined the spins J of resonances in the 147Sm(n,gamma) reaction by measuring multiplicities of gamma-ray cascades following neutron capture. Using this technique, we were able to determine J values for all but 14 of the 140 known resonances below En = 1 keV, including 41 firm J assignments for resonances whose spins previously were either unknown or tentative. These new spin assignments, together with previously determined resonance parameters, allowed us to extract separate level spacings and neutron strength functions for J = 3 and 4 resonances. Furthermore, several statistical test of the data indicate that very few resonances of either spin have been missed below En = 700eV. Because a non-statistical effect recently was reported near En = 350 eV from an analysis of 147Sm(n,alpha) data, we divided the data into two regions; 0 < En < 350 eV and 350 < En < 700 eV. Using neutron widths from a previous measurement and published techniques for correcting for missed resonances and for testing whether data are consistent with a Porter-Thomas distribution, we found that the reduced-neutron-width distribution for resonances below 350 eV is consistent with the expected Porter-Thomas distribution. On the other hand, we found that reduced-neutron-width data in the 350 < En < 700 eV region are inconsistent with a Porter-Thomas distribution, but in good agreement with a chi-squared distribution having two or more degrees of freedom. We discuss possible explanations for these observed non-statistical effects and their possible relation to similar effects previously observed in other nuclides.Comment: 40 pages, 13 figures, accepted by Phys. Rev.
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