436 research outputs found

    Comparative studies of the Pschorr reaction in the pyrazole series. Access to the new dibenzo(e,g)pyrazolo(1,5-a)(1,3)diazocine system of pharmaceutical interest

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    The diazonium tetrafluoroborate 11 obtained from 2-amino-N-methyl-N-(1-phenyl-3-methylpyrazol-5-yl)benzamide was transformed in dry acetonitrile via an ionic or radical pathway. Diferences were observed with respect to ionic or radical transformations in aqueous media of the analogous diazonium hydrogen sulfate 1 derived from the same amine. In acetonitrile solution, the ionic pathway was characterized by an increased yield of 1,4-dimethyl-3-phenyl-pyrazolo[3,4-c]isoquinolin-5-one 4 and by the formation of its isomer, the new derivative 7,9-dimethyldibenzo[e,g]pyrazolo[1,5-a][1,3]diazocin-10(9H)-one 12. When the reaction folowed a radical pathway, the pyrazolo[3,4-c]isoquinoline derivative 4 and N-methyl-2-(1-phenyl-3-methylpyrazol-5-yl)benzamide 17, the later due to a 1,4-pyrazolyl transfer proces, were isolated in low yields. Decomposition of the solid diazonium tetrafluoroborate at its melting point gave compounds 4, 12 and the N-(1-phenyl-3-methylpyrazol-5-yl)-2-fluorobenzamide 17. The crystal structure of compound 12 was also determined

    Developing a Cross-Generational Life-Transforming Worship Service: an Approach to Involving and Empowering Youth and Young Adults at the San Diego Filipino-American Seventh-day Adventist Church

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    The Problem. The worship services at San Diego Fil-Am were traditionally led by the older generations where most of the time the younger generations felt neglected to and left out in the planning and from experiencing a life-transforming worship. For some time, the younger generations sought opportunities to be involved in worship but the traditional practice of worship did not favor it. Advocates for children and young people in the congregation urge separate worship services for the youth and young adults but this is strongly opposed by the majority of leaders and senior members, many of whom hold leadership positions on the Church Board. This situation has affected the interest, the attendance, and the participation of the youth and young adults in worship. The Method. This project dissertation presents a survey of biblical foundation for a corporate cross-generational life transforming worship as well as guidelines and suggestions for developing a cross-generational, intergenerational, or multi-generational (CIM) model of worship with intentional involvement, training and equipping of the younger generations. It integrates methods and principles from current literature on CIM worship relevant to planning, implementing, and evaluating a CIM life-transforming worship at the San Diego Fil-Am SDA Church. Results. There were six people from younger generations trained and equipped as worship leaders. The involvement of the younger generations in planning and leading worship greatly contributed to a higher percentage of the younger members leading, noticeably the young adults, in worship. The worship attendance among the younger generations has increased. The more inspiring result of this process was manifested in the church members’ becoming more prayerful, more engaged in the ministry, more caring and loving to one another, more focused and alive in worship, and in serving others. The CGLTW was considered a process, a life-transforming experience, not only for the older and younger worship leaders, but for all generations in the congregation. Conclusions. The priority of this project is to develop younger generations in worship leadership, equipping them to assist or lead in improving worship services by designing, implementing, and evaluating life-transforming worship services that involves all the generations (all age groups) in the congregation. By giving the younger generations the opportunities to be involved they truly felt that they belong, their relationship to the church community was strengthened and their worship experience became life-transforming

    The AEgIS experiment at CERN: Measuring antihydrogen free-fall in earth's gravitational field to test WEP with antimatter

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    The AEgIS (Antimatter Experiment: Gravity, Interferometry, Spectroscopy) experiment is designed with the objective to test the weak equivalence principle with antimatter by studying the free fall of antihydrogen in the Earth's gravitational field. A pulsed cold beam of antihydrogen will be produced by charge exchange between cold Ps excited in Rydberg state and cold antiprotons. Finally the free fall will be measured by a classical moir\ue9 deflectometer. The apparatus being assembled at the Antiproton Decelerator at CERN will be described, then the advancements of the experiment will be reported: positrons and antiprotons trapping measurements, Ps two-step excitation and a test-measurement of antiprotons deflection with a small scale moir\ue9 deflectometer

    A Method to Improve the Flood Maps Forecasted by On-Line Use of 1D Model

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    Forecasting floods in urban areas during a heavy rainfall is the aim of every early warning system. 2D-models produce the most accurate flood maps, but they are practically useless as quasi real-time tools, because their run times are comparable to times of propagation of floods. Run times of 1D-model are of tens of seconds, but their predictions lack accuracy and many useful indicators of flood severity. Our aim is the identification of the 2D-model map that is more similar to the actual map, chosen among those simulated off-line. To this aim, we produce a rough flood map of the occurring event, through a quasi real-time simulation of the rainfall-runoff using a 1D-model. Then we apply an original method, named "ranking approach", to perform the best matching. This method is applied to the Corace torrent (Calabria, Southern Italy), using 17 synthetic hyetographs to simulate the same number of rainfall-runoff events, using 1D (SWMM) and 2D (MIKE) models. The method proves to be effective in 65% of the cases, while in 82% of cases (i.e., for 14 cases out 17), the event produced by the same ietograph falls within the third rank

    Laser excitation of the n=3 level of positronium for antihydrogen production

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    We demonstrate the laser excitation of the n = 3 state of positronium (Ps) in vacuum. A combination of a specially designed pulsed slow positron beam and a high-efficiency converter target was used to produce Ps. Its annihilation was recorded by single-shot positronium annihilation lifetime spectroscopy. Pulsed laser excitation of the n = 3 level at a wavelength lambda approximate to 205 nm was monitored via Ps photoionization induced by a second intense laser pulse at lambda = 1064 nm. About 15% of the overall positronium emitted into vacuum was excited to n = 3 and photoionized. Saturation of both the n = 3 excitation and the following photoionization was observed and explained by a simple rate equation model. The positronium's transverse temperature was extracted by measuring the width of the Doppler-broadened absorption line. Moreover, excitation to Rydberg states n = 15 and 16 using n = 3 as the intermediate level was observed, giving an independent confirmation of excitation to the 3 P-3 state

    Tratamiento de la obesidad

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    Adversarial EXEmples: A Survey and Experimental Evaluation of Practical Attacks on Machine Learning for Windows Malware Detection

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    Recent work has shown that adversarial Windows malware samples - referred to as adversarial EXEmples in this article - can bypass machine learning-based detection relying on static code analysis by perturbing relatively few input bytes. To preserve malicious functionality, previous attacks either add bytes to existing non-functional areas of the file, potentially limiting their effectiveness, or require running computationally demanding validation steps to discard malware variants that do not correctly execute in sandbox environments. In this work, we overcome these limitations by developing a unifying framework that does not only encompass and generalize previous attacks against machine-learning models, but also includes three novel attacks based on practical, functionality-preserving manipulations to the Windows Portable Executable file format. These attacks, named Full DOS, Extend, and Shift, inject the adversarial payload by respectively manipulating the DOS header, extending it, and shifting the content of the first section. Our experimental results show that these attacks outperform existing ones in both white-box and black-box scenarios, achieving a better tradeoff in terms of evasion rate and size of the injected payload, while also enabling evasion of models that have been shown to be robust to previous attacks. To facilitate reproducibility of our findings, we open source our framework and all the corresponding attack implementations as part of the secml-malware Python library. We conclude this work by discussing the limitations of current machine learning-based malware detectors, along with potential mitigation strategies based on embedding domain knowledge coming from subject-matter experts directly into the learning process

    ImageNet-Patch: A dataset for benchmarking machine learning robustness against adversarial patches

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    Adversarial patches are optimized contiguous pixel blocks in an input image that cause a machine-learning model to misclassify it. However, their optimization is computationally demanding, and requires careful hyperparameter tuning, potentially leading to suboptimal robustness evaluations. To overcome these issues, we propose ImageNet-Patch, a dataset to benchmark machine-learning models against adversarial patches. The dataset is built by first optimizing a set of adversarial patches against an ensemble of models, using a state-of-the-art attack that creates transferable patches. The corresponding patches are then randomly rotated and translated, and finally applied to the ImageNet data. We use ImageNet-Patch to benchmark the robustness of 127 models against patch attacks, and also validate the effectiveness of the given patches in the physical domain (i.e., by printing and applying them to real-world objects). We conclude by discussing how our dataset could be used as a benchmark for robustness, and how our methodology can be generalized to other domains. We open source our dataset and evaluation code at https://github.com/pralab/ImageNet-Patch

    Crystalline polymeric carbon dioxide stable at megabar pressures

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    The nature and stability of carbon dioxide under extreme conditions relevant to the Earth’s mantle is still under debate, in view of its possible role within the deep carbon cycle. Here, the authors perform high-pressure experiments providing evidence that polymeric crystalline CO2 is stable under megabaric conditions

    High-voltage Sensor Based on Fiber Bragg Grating in Fibers with Electrodes

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    [EN] This work describes the use of FBGs inscribed in optical fiber with electrodes for voltage sensing. The results show a quadratic voltage dependence. The device can be explored for a multipoint, single-ended voltage sensing device.The authors acknowledge financial support from the FINESSE project. FINESSE is funded by the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska - Curie grant agreement n° 722509. Partial funding from K. A. Wallenberg Foundation and the Swedish Science Council is gratefully acknowledged. We also thank Kenny Hey Tow (RISE, Sweden) for useful discussions.Pereira, JMB.; Sartiano, D.; Hervás, J.; Barrera, D.; Madrigal-Madrigal, J.; Sales Maicas, S.; Laurell, F.... (2020). High-voltage Sensor Based on Fiber Bragg Grating in Fibers with Electrodes. IEEE. 1-2. http://hdl.handle.net/10251/177479S1
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