1,180 research outputs found

    The cultural elite in Latin America

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    "Seminar on Latin American Elites, Montevideo, Uruguay, June, 1965.""1636"--handwritten on coverIncludes bibliographical referencesSponsored by the Institute of International Studies, University of California ... [et al.

    DISEÑO DE SISTEMA DE CONTROL EN UN INVERNADERO BASADO EN ROBÓTICA EDUCATIVA NEURON

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    Para el cultivo de verduras y hortalizas en un invernadero es importante monitorear y controlar variables como la humedad del suelo, la luminosidad y la temperatura ambiente. Este proyecto tiene como objetivo diseñar un sistema de control de invernadero inteligente, utilizando el kit de robótica educativa Neuron. Mediante la implementación de programación por bloques es posible desarrollar algoritmos de fácil entendimiento que permitan monitorear y controlar estas variables para aumentar la productividad de la cosecha de verduras y hortalizas en el municipio de Santa María. Con el desarrollo del proyecto se logró determinar que el kit Neuron es aplicable al desarrollo de soluciones de la cuarta revolución industrial en diferentes escenarios bajo el enfoque STEAM, entre ellos el monitoreo de variables de un invernadero, así mismo, se validó la pertinencia del proyecto en el municipio y se diseñó un sistema de monitoreo y control de la humedad del suelo, luminosidad y temperatura ambiente para ser aplicado a un invernadero inteligent

    Isolation and detection of circulating tumour cells from metastatic melanoma patients using a slanted spiral microfluidic device.

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    Circulating Tumour Cells (CTCs) are promising cancer biomarkers. Several methods have been developed to isolate CTCs from blood samples. However, the isolation of melanoma CTCs is very challenging as a result of their extraordinary heterogeneity, which has hindered their biological and clinical study. Thus, methods that isolate CTCs based on their physical properties, rather than surface marker expression, such as microfluidic devices, are greatly needed in melanoma. Here, we assessed the ability of the slanted spiral microfluidic device to isolate melanoma CTCs via label-free enrichment. We demonstrated that this device yields recovery rates of spiked melanoma cells of over 80% and 55%, after one or two rounds of enrichment, respectively. Concurrently, a two to three log reduction of white blood cells was achieved with one or two rounds of enrichment, respectively. We characterised the isolated CTCs using multimarker flow cytometry, immunocytochemistry and gene expression. The results demonstrated that CTCs from metastatic melanoma patients were highly heterogeneous and commonly expressed stem-like markers such as PAX3 and ABCB5. The implementation of the slanted microfluidic device for melanoma CTC isolation enables further understanding of the biology of melanoma metastasis for biomarker development and to inform future treatment approaches

    Immunomagnetic-enriched subpopulations of melanoma circulating tumour cells (CTCs) exhibit distinct transcriptome profiles

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    Cutaneous melanoma circulating tumour cells (CTCs) are phenotypically and molecularly heterogeneous. We profiled the gene expression of CTC subpopulations immunomagnetic-captured by targeting either the melanoma-associated marker, MCSP, or the melanoma-initiating marker, ABCB5. Firstly, the expression of a subset of melanoma genes was investigated by RT-PCR in MCSP-enriched and ABCB5-enriched CTCs isolated from a total of 59 blood draws from 39 melanoma cases. Of these, 6 MCSP-and 6 ABCB5-enriched CTC fractions were further analysed using a genome-wide gene expression microarray. The transcriptional programs of both CTC subtypes included cell survival maintenance, cell proliferation, and migration pathways. ABCB5-enriched CTCs were specifically characterised by up-regulation of genes involved in epithelial to mesenchymal transition (EMT), suggesting an invasive phenotype. These findings underscore the presence of at least two distinct melanoma CTC subpopulations with distinct transcriptional programs, which may have distinct roles in disease progression and response to therapy. © 2019 by the authors. Licensee MDPI, Basel, Switzerland

    Earthquake research in China

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    A visit to China of an American seismological delegation, which took place October 5 to November 5, 1974, is covered in this report. The Americans were sponsored by the Committee on Scholarly Communication with the People's Republic of China (CSCPRC), and the hosts in China were the Scientific and Technical Association and the State Seismological Bureau. The CSCPRC is sponsored jointly by the National Academy of Sciences, the Social Science Research Council, and the American Council of Learned Societies. The visit had its origins in an invitation extended in January 1973 by Carl Kisslinger, as President of the Seismological Society of America, to the Chinese Academy of Sciences to send representatives to a Symposium on Earthquake Prediction Research. Although the Chinese declined to participate, this invitation was one step towards a reciprocal exchange of seismologists between the United States and the People's Republic of China. Several months after Kisslinger's letter the CSCPRC visited Peking. Their purpose was to arrange an exchange program with the Chinese Scientific and Technical Association. Prompted by Kisslinger, the committee's proposals for American delegations included seismology. Not only was this particular exchange accepted, but the Chinese in turn suggested that a Chinese seismology group visit the United States

    Discordance rates of biopsy techniques among men with prostate cancer that are candidates for active surveillance

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    Q1Q1e887-e887INTRODUCTION AND OBJECTIVES: With the ongoing stage migration in the diagnosis of prostate cancer, there has been increased interest in management with active surveillance. Our study examines the ability of two prostate biopsy techniques to predict appropriate candidates for active surveillance.METHODS500 consecutive patients, between 2005 and 2007, that underwent trans-rectal ultrasound guided biopsy by either an office biopsy with 12 cores or a saturation biopsy with ≥18 cores, and subsequent radical prostatectomy were identified. Using criteria of: Gleason score ≤6, clinical stage T1 or T2a, Prostate Specific Antigen (PSA) <10 and ≤33% of cores involved, 220 patients were found to be candidates for active surveillance. Pathology results from the prostatectomy specimens were used determine the discordance rate of each biopsy technique.RESULTSOf the 220 candidates for active surveillance, 124 patients underwent an office biopsy with 12 cores, and 96 patients underwent a saturation biopsy. The median number of cores in the saturation biopsy cohort was 27. There was no statistically significant difference between the groups in terms of median age (p=0.18), pre-operative PSA (p=0.48) and clinical stage (p=0.2). At least one previous negative biopsy had been performed on 20 patients (16%) in the office cohort and 43 patients (45%) in the saturation cohort (p= <0.001). In the 12 core biopsy group, 17 patients (14%) were upgraded to Gleason 7 on pathology from the prostatectomy specimen. In the saturation biopsy group, 14 patients (15%) were upgraded to Gleason 7, and 1 patient (1%) was upgraded to Gleason 8. There was no statistically significant difference in the rate of upgrading between the office and saturation biopsy cohorts (p=0.69). In the office biopsy group, 2 patients (1.6%) were upstaged to pT3 disease, compared to 0 patients (0%) in the saturation biopsy group (p=0.58). No statistically significant difference in the estimated tumor volume of the prostatectomy specimen was seen between the cohorts (p=0.47).CONCLUSIONSCandidates for active surveillance can accurately be predicted with 12 core biopsies. In both cohorts, approximately 1 in 6 patients underwent upgrading based on the pathology of the prostatectomy specimen

    Experimental analysis and mathematical prediction of Cd(II) removal by biosorption using support vector machines and genetic algorithms

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    We investigated the bioremoval of Cd(II) in batch mode, using dead and living biomass of Trichoderma viride. Kinetic studies revealed three distinct stages of the biosorption process. The pseudo-second order model and the Langmuir model described well the kinetics and equilibrium of the biosorption process, with a determination coefficient, R2 > 0.99. The value of the mean free energy of adsorption, E, is less than 16 kJ/mol at 25°C, suggesting that, at low temperature, the dominant process involved in Cd(II) biosorption by dead T. viride is the chemical ion-exchange. With the temperature increasing to 4050°C, E values are above 16 kJ/mol, showing that the particle diffusion mechanism could play an important role in Cd(II) biosorption. The studies on T. viride growth in Cd(II) solutions and its bioaccumulation performance showed that the living biomass was able to bioaccumulate 100% Cd(II) from a 50 mg/L solution at pH 6.0. The influence of pH, biomass dosage, metal concentration, contact time and temperature on the bioremoval efficiency was evaluated to further assess the biosorption capability of the dead biosorbent. These complex influences were correlated by means of a modeling procedure consisting in data driven approach in which the principles of artificial intelligence were applied with the help of support vector machines (SVM), combined with genetic algorithms (GA). According to our data, the optimal working conditions for the removal of 98.91% Cd(II) by T. viride were found for an aqueous solution containing 26.11 mg/L Cd(II) as follows: pH 6.0, contact time of 3833 min, 8 g/L biosorbent, temperature 46.5°C. The complete characterization of bioremoval parameters indicates that T. viride is an excellent material to treat wastewater containing low concentrations of metal

    Distributed Observer Network

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    The Distributed Observer network (DON) is a NASA-collaborative environment that leverages game technology to bring three-dimensional simulations to conventional desktop and laptop computers in order to allow teams of engineers working on design and operations, either individually or in groups, to view and collaborate on 3D representations of data generated by authoritative tools such as Delmia Envision, Pro/Engineer, or Maya. The DON takes models and telemetry from these sources and, using commercial game engine technology, displays the simulation results in a 3D visual environment. DON has been designed to enhance accessibility and user ability to observe and analyze visual simulations in real time. A variety of NASA mission segment simulations [Synergistic Engineering Environment (SEE) data, NASA Enterprise Visualization Analysis (NEVA) ground processing simulations, the DSS simulation for lunar operations, and the Johnson Space Center (JSC) TRICK tool for guidance, navigation, and control analysis] were experimented with. Desired functionalities, [i.e. Tivo-like functions, the capability to communicate textually or via Voice-over-Internet Protocol (VoIP) among team members, and the ability to write and save notes to be accessed later] were targeted. The resulting DON application was slated for early 2008 release to support simulation use for the Constellation Program and its teams. Those using the DON connect through a client that runs on their PC or Mac. This enables them to observe and analyze the simulation data as their schedule allows, and to review it as frequently as desired. DON team members can move freely within the virtual world. Preset camera points can be established, enabling team members to jump to specific views. This improves opportunities for shared analysis of options, design reviews, tests, operations, training, and evaluations, and improves prospects for verification of requirements, issues, and approaches among dispersed teams

    Performance of the CMS Cathode Strip Chambers with Cosmic Rays

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    The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns
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