685 research outputs found
Simulation of a solar funnel cooker using MATLAB
A software for the calculation of the radiation heat transfer in solar funnel cookers by means of the radiosity method has been developed in Matlab. The software has been used to study a folding solar cooker. The cooker geometry is discretized using a triangular mesh where a piecewise constant approximation is assumed for the radiosity function. Form factors, including self-occlusions, are calculated by properly refining the triangular mesh. The concentration factor of the solar cooker is estimated as a function of its position and orientation with respect to that of the Sun.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
NudE regulates dynein at kinetochores but is dispensable for other dynein functions in the C. elegans early embryo
In mitosis, themolecular motor dynein is recruited to kinetochores by the Rod-Zw10-Zwilch complex (RZZ) and Spindly to control spindle assembly checkpoint (SAC) signaling and microtubule attachment. How the ubiquitous dynein co-factors Lis1 and NudE contribute to these functions remains poorly understood. Here, we show that the C. elegans NudE homolog NUD-2 is dispensable for dynein- and LIS-1-dependent mitotic spindle assembly in the zygote. This facilitates functional characterization of kinetochore-localized NUD-2, which is recruited by the CENP-F-like proteins HCP-1 and HCP-2 independently of RZZ- Spindly and dynein-LIS-1. Kinetochore dynein levels are reduced in ¿nud-2 embryos, and, as occurs upon RZZ inhibition, loss of NUD-2 delays the formation of load-bearing kinetochore-microtubule attachments and causes chromatin bridges in anaphase. Survival of ¿nud-2 embryos requires a functional SAC, and kinetochores without NUD-2 recruit an excess of SAC proteins. Consistent with this, SAC signaling in early ¿nud-2 embryos extends mitotic duration and prevents high rates of chromosome mis-segregation. Our results reveal that both NUD-2 and RZZ-Spindly are essential for dynein function at kinetochores, and that the gain in SAC strength during early embryonic development is relevant under conditions that mildly perturb mitosis.This project was funded by the European Research Council under the European Union’s Seventh Framework Programme (ERC grant agreement no. ERC-2013-StG-338410-DYNEINOME to R.G.), and the European Union’s Horizon 2020 Research and Innovation Programme (ERC grant agreement no. ERC-2014-StG-640553-ACTOMYO to A.X.C.). Additional funding was fromthe European Molecular Biology Organization (Installation Grant; R.G.), from the Fundação para a Ciência e a Tecnologia(IF/01015/2013/CP1157/CT0006; R.G.), and from the project ‘Norte-01-0145-FEDER-000029, Advancing cancer research: from basic knowledge to application’, supported by the Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement through the European Regional Development Fund (FEDER). Deposited in PMC for immediate release
Toward the S3DVAR data assimilation software for the Caspian Sea
Data Assimilation (DA) is an uncertainty quantification technique used to incorporate observed data into a prediction model in order to improve numerical forecasted results. The forecasting model used for producing oceanographic prediction into the Caspian Sea is the Regional Ocean Modeling System (ROMS). Here we propose the computational issues we are facing in a DA software we are developing (we named S3DVAR) which implements a Scalable Three Dimensional Variational Data Assimilation model for assimilating sea surface temperature (SST) values collected into the Caspian Sea with observations provided by the Group of High resolution sea surface temperature (GHRSST). We present the algorithmic strategies we employ and the numerical issues on data collected in two of the months which present the most significant variability in water temperature: August and March
Characterization of a β-glucanase produced by Rhizopus microsporus var. microsporus, and its potential for application in the brewing industry
BACKGROUND: In the barley malting process, partial hydrolysis of β-glucans begins with seed germination. However, the endogenous 1,3-1,4-β-glucanases are heat inactivated, and the remaining high molecular weight β-glucans may cause severe problems such as increased brewer mash viscosity and turbidity. Increased viscosity impairs pumping and filtration, resulting in lower efficiency, reduced yields of extracts, and lower filtration rates, as well as the appearance of gelatinous precipitates in the finished beer. Therefore, the use of exogenous β-glucanases to reduce the β-glucans already present in the malt barley is highly desirable. RESULTS: The zygomycete microfungus Rhizopus microsporus var. microsporus secreted substantial amounts of β-glucanase in liquid culture medium containing 0.5% chitin. An active protein was isolated by gel filtration and ion exchange chromatographies of the β-glucanase activity-containing culture supernatant. This isolated protein hydrolyzed 1,3-1,4-β-glucan (barley β-glucan), but showed only residual activity against 1,3-β-glucan (laminarin), or no activity at all against 1,4-β-glucan (cellulose), indicating that the R. microsporus var. microsporus enzyme is a member of the EC 3.2.1.73 category. The purified protein had a molecular mass of 33.7 kDa, as determined by mass spectrometry. The optimal pH and temperature for hydrolysis of 1,3-1,4-β-glucan were in the ranges of 4–5, and 50–60°C, respectively. The Km and Vmax values for hydrolysis of β-glucan at pH 5.0 and 50°C were 22.39 mg.mL(-1 )and 16.46 mg.min(-1), respectively. The purified enzyme was highly sensitive to Cu(+2), but showed less or no sensitivity to other divalent ions, and was able to reduce both the viscosity and the filtration time of a sample of brewer mash. In comparison to the values determined for the mash treated with two commercial glucanases, the relative viscosity value for the mash treated with the 1,3-1,4-β-glucanase produced by R. microsporus var. microsporus. was determined to be consistently lower. CONCLUSION: The zygomycete microfungus R. microsporus var. microsporus produced a 1,3-1,4-β-D-glucan 4-glucanhydrolase (EC 3.2.1.73) which is able to hydrolyze β-D-glucan that contains both the 1,3- and 1,4-bonds (barley β-glucans). Its molecular mass was 33.7 kDa. Maximum activity was detected at pH values in the range of 4–5, and temperatures in the range of 50–60°C. The enzyme was able to reduce both the viscosity of the brewer mash and the filtration time, indicating its potential value for the brewing industry
Diagnóstico da fertilidade do solo e do estado nutricional de pimenteira-do-reino na Transamazônica, em agricultura familiar.
bitstream/item/48624/1/Boletim-PD-24-AMAZ-ORIENTAL.pd
Carceleras : argumento del drama lírico en un acto y tres cuadros, letra de Ricardo R. Flores, música del maestro Vicente Peydró
Copia digital. Valladolid : Junta de Castilla y León. Consejería de Cultura y Turismo, 2009-201
Crescimento vegetativo e reprodutivo em plantas de pinhão manso sob condições de campo, Altamira-PA.
Modernismos, literatura dramática e sociedade brasileira na virada do século 20
From the origin processes of Modernism in Europe, the paper proposes to think about the Brazilian theatrical situation of the time through the analysis of the social, political and economic characteristics of the local population between 19th and 20th centuries. As a result, it discusses the hypothesis that there was in that period a certain conjuncture acting as an obstacle to the establishment of the social conditions necessary for the installation of modernist theatrical ideas.A partir dos processos de origem do Modernismo na Europa, o artigo propõe pensar a situação teatral brasileira da época por meio da análise das características sociais, políticas e econômicas da população local entre os séculos 19 e 20. Discute-se como resultado a hipótese de que havia nesse período certa conjuntura agindo como obstáculo para a instauração das condições sociais necessárias à instalação das ideias teatrais modernistas
Characterization and control of a robot for wrist rehabilitation
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2003.Includes bibliographical references (p. 209-214).Human motor control pathologies, such as those caused by stroke, can be treated through physical rehabilitation. The use of robots in therapy environments seems appropriate considering the possibilities they offer for quantification of performance as well as "quality control" between therapy sessions. The research presented in this thesis is part of the continuing development of robotic applications for physical therapy and neuro-rehabilitation at the Newman Laboratory for Biomechanics and Human Rehabilitation. MIT-MANUS, a robot for shoulder and elbow therapy developed in this lab, introduced this new brand of therapy, offering a highly backdrivable mechanism with a soft and stable feel for the user. The focus here is the development, characterization, and implementation of a robot for wrist rehabilitation, designed to provide three rotational degrees of freedom. The wrist motions of flexion/extension and abduction/adduction are governed by a differential gear mechanism, while pronation and supination of the forearm are actuated by a curved slider attached to the rest of the mechanism. Through the characterization, the device was found to exhibit some unwanted behavior, largely attributable to the nonlinearities inherent in the system. Efforts to suppress these effects through control are presented along with recommendations for addressing these problems at the design level.(cont.) The alpha prototype has been set up for clinical trials by providing a functional control scheme along with "video game" patient interfaces; initial clinical trials will run in parallel with the development of the next version of the device. If improvements comparable to those seen with the use of MIT-MANUS are seen with the wrist robot, then rehabilitation therapists will have a new and useful tool at their disposal.by James R. Celestino.S.M
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