1,477 research outputs found
VETA x ray data acquisition and control system
We describe the X-ray Data Acquisition and Control System (XDACS) used together with the X-ray Detection System (XDS) to characterize the X-ray image during testing of the AXAF P1/H1 mirror pair at the MSFC X-ray Calibration Facility. A variety of X-ray data were acquired, analyzed and archived during the testing including: mirror alignment, encircled energy, effective area, point spread function, system housekeeping and proportional counter window uniformity data. The system architecture is presented with emphasis placed on key features that include a layered UNIX tool approach, dedicated subsystem controllers, real-time X-window displays, flexibility in combining tools, network connectivity and system extensibility. The VETA test data archive is also described
Academic Problem-Solving and Students’ identities as engineers
Socially constructed identities and language practices influence the ways students perceive themselves as learners, problem solvers, and future professionals. While research has been conducted on individuals’ identity as engineers, less has been written about how the language used during engineering problem solving influences students’ perceptions and their construction of identities as learners and future engineers. This study investigated engineering students’ identities as reflected in their use of language and discourses while engaged in an engineering problem solving activity. We conducted interviews with eight engineering students at a large southeastern university about their approaches to open and closed-ended materials engineering problems. A modification of Gee’s analysis of language-in-use was used to analyze the interviews. We found that pedagogical and engineering problem solving uses of language were the most common. Participants were more likely to perceive themselves as students highlighting the practices, expectations, and language associated with being a student rather than as emerging engineers whose practices are affected by conditions of professional practice. We suggest that problem solving in an academic setting may not encourage students to consider alternative discourses related to industry, professionalism, or creativity; and, consequently, fail to promote connections to social worlds beyond the classroom. By learning about the ways in which language in particular settings produces identities and shapes problem solving practices, educators and engineering professionals can gain deeper understanding of how language shapes the ways students describe themselves as problem-solvers and make decisions about procedures and techniques to solve engineering problems
Comience aquí, o aquí, no aquí: Introduções para repensar a política e a metodologia educativa em uma era pós-verdad
This special issue takes up urgent questions about how we education scholars might think and do policy and methodology in what has come to be known as the post-truth era. The authors in this special issue grapple with questions about the roles and responsibilities of educational researchers in an era in which research and policy have lost their moorings in T/truth. Collectively they reconceptualize educational research and policy in light of post-truths, anti-science sentiment, and the global rise of right-wing populism. At the same time we editors wonder whether post-truth is given a bad rap. Could post-truth have something productive to offer? What does post-truth open up for educational research and policy? Or, is the real issue of this special issue a collective despair of our own insignificance and obsolescence in the wake of post-truth. Whatever we editors and authors aimed to do, this special issue will not be heard by post-truth adherents and partisans. Perhaps its only contribution is encouragement to stay with the troubles of a post-truth era, even as we despair the consequences of our research and policy creations.Este número especial plantea preguntas urgentes sobre cómo los académicos de la educación pueden pensar y hacer políticas y metodologías en una era posverdad. Los autores se enfrentan a preguntas sobre los roles y responsabilidades de los investigadores educativos en un momento en que la investigación y la política han perdido sus amarres en V/verdad. En conjunto, reconceptualizan la investigación y la política educativa a la luz de las posverdades, el sentimiento anticientífico y el auge mundial del populismo de derecha. Los editores también se preguntan si a la posverdad se le da una mala reputación. ¿Podría la posverdad tener algo productivo que ofrecer? ¿Qué abre la posverdad a la investigación y la política educativa? O bien, ¿es el problema real de este número especial una desesperación colectiva de nuestra propia insignificancia y obsolescencia después de la posverdad? Independientemente de lo que nosotros (los editores y autores) pretendamos hacer, este número especial no será escuchado por los partidarios y partidarios de la posverdad. Quizás su única contribución sea un estímulo para permanecer con los problemas de una era posverdad, incluso cuando nos desesperamos por las consecuencias de nuestras investigaciones y creaciones de políticas.Esta dossiê especial levanta questões urgentes sobre como os estudiosos da educação podem pensar e fazer políticas e metodologias em uma era pós-verdade. Os autores se deparam com questões sobre os papéis e responsabilidades dos pesquisadores educacionais em um momento em que a pesquisa e a política perderam seus laços na verdade. Juntos, eles reconceitualizam a pesquisa e a política educacional à luz das verdades posteriores, do sentimento anti-científico e da ascensão mundial do populismo de direita. Os editores também se perguntam se a verdade posterior recebe uma má reputação. A pós-verdade poderia ter algo produtivo para oferecer? O que abre a verdade depois da pesquisa e da política educacional? Ou o verdadeiro problema desta questão especial é um desespero coletivo de nossa própria insignificância e obsolescência depois da verdade posterior? Independentemente do que nós (editores e autores) pretendemos fazer, esta edição especial não será ouvida pelos apoiadores e apoiadores da verdade posterior. Talvez sua única contribuição seja um incentivo para permanecer com os problemas de uma era pós-verdade, mesmo quando nos desesperamos com as conseqüências de nossa pesquisa e elaboração de políticas
VETA x ray data acquisition and control system
We describe the X-ray Data Acquisition and Control System (XDACS) used together with the X-ray Detection System (XDS) to characterize the x-ray image during testing of the AXAF P1/H1 mirror pair at the MSFC X-ray Calibration Facility. A variety of x-ray data were acquired, analyzed, and archived during the testing including: mirror alignment, encircled energy, effective area, point spread function, system housekeeping, and proportional counter window uniformity data. The system architecture will be presented with emphasis placed on key features that include a layered UNIX tool approach, dedicated subsystem controllers, real-time X-window displays, flexibility in combining tools, network connectivity, and system extensibility. The VETA test data archive are also described
Localization of a 64-kDa phosphoprotein in the lumen between the outer and inner envelopes of pea chloroplasts
The identification and localization of a marker protein for the intermembrane space between the outer and inner chloroplast envelopes is described. This 64-kDa protein is very rapidly labeled by [γ-32P]ATP at very low (30 nM) ATP concentrations and the phosphoryl group exhibits a high turnover rate. It was possible to establish the presence of the 64-kDa protein in this plastid compartment by using different chloroplast envelope separation and isolation techniques. In addition comparison of labeling kinetics by intact and hypotonically lysed pea chloroplasts support the localization of the 64-kDa protein in the intermembrane space. The 64-kDa protein was present and could be labeled in mixed envelope membranes isolated from hypotonically lysed plastids. Mixed envelope membranes incorporated high amounts of 32P from [γ-32P]ATP into the 64-kDa protein, whereas separated outer and inner envelope membranes did not show significant phosphorylation of this protein. Water/Triton X-114 phase partitioning demonstrated that the 64-kDa protein is a hydrophilic polypeptide. These findings suggest that the 64-kDa protein is a soluble protein trapped in the space between the inner and outer envelope membranes. After sonication of mixed envelope membranes, the 64-kDa protein was no longer present in the membrane fraction, but could be found in the supernatant after a 110000 × g centrifugation
Systematic review of perioperative and quality-of-life outcomes following surgical management of localised renal cancer
UCAN Cancer Charity (www.ucanhelp.org.uk) and MacMillan Cancer Charity (www.macmillan.org.uk) helped design and conduct the study.Peer reviewedPostprin
PLA/WOOD BIOCOMPOSITES: IMPROVING COMPOSITE STRENGTH BY CHEMICAL TREATMENT OF THE FIBERS
A resol type phenolic resin was prepared for the impregnation of wood particles used for the reinforcement of PLA. A preliminary study showed that the resin penetrates wood with rates depending on the concentration of the solution and on temperature. Treatment with a solution of 1 wt% resin resulted in a considerable increase of composite strength and decrease of water absorption. Composite strength improved as a result of increased inherent strength of the wood, but interfacial adhesion might be modified as well. When wood was treated with resin solutions of larger concentrations, the strength of the composites decreased, first slightly, then drastically to a very small value. A larger amount of resin results in a thick coating on wood with inferior mechanical properties. At large resin contents the mechanism of deformation changes; the thick coating breaks very easily leading to the catastrophic failure of the composites at very small loads
Fiber association and network formation in PLA/lignocellulosic fiber composites.
PLA composites were prepared in an internal mixer with a lignocellulosic fiber having relatively large aspect ratio. Fiber content changed between 0 and 60 vol% and the homogenized material was compression molded to 1 mm thick plates. The composites showed anomalous behavior above certain fiber content. Their modulus and especially their strength decreased drastically and modeling also proved the loss of reinforcement at large fiber contents. Micromechanical testing showed that the mechanism of deformation and failure changes at a critical fiber content. Microscopic analysis indi-cated the formation of a network purely from geometrical reasons. The inherent strength of the network is very small because of the weak forces acting among the fibers. This weak inherent strength makes the structure of the composites very sensitive to pro-cessing conditions, and decreases strength, reproducibility as well as reliability
An AARS variant as the likely cause of Swedish type hereditary diffuse leukoencephalopathy with spheroids
Swedish type Hereditary Diffuse Leukoencephalopathy with Spheroids (HDLS-S) is a severe adult-onset leukoencephalopathy with the histopathological hallmark of neuraxonal degeneration with spheroids, described in a large family with a dominant inheritance pattern. The initial stage of the disease is dominated by frontal lobe symptoms that develop into a rapidly advancing encephalopathy with pyramidal, deep sensory, extrapyramidal and optic tract symptoms. Median survival is less than 10 years. Recently, pathogenic mutations in CSF1R were reported in a clinically and histologically similar leukoencephalopathy segregating in several families. Still, the cause of HDLS-S remained elusive since its initial description in 1984, with no CSF1R mutations identified in the family. Here we update the original findings associated with HDLS-S after a systematic and recent assessment of several family members. We also report the results from exome sequencing analyses indicating the p.Cys152Phe variant in the alanyl tRNA synthetase (AARS) gene as the probable cause of this disease. The variant affects an amino acid located in the aminoacylation domain of the protein and does not cause differences in splicing or expression in the brain. Brain pathology in one case after 10 years of disease duration showed the end stage of the disease to be characterized by widespread liquefaction of the white matter leaving only some macrophages and glial cells behind the centrifugally progressing front. These results point to AARS as a candidate gene for rapidly progressing adult-onset CSF1R-negative leukoencephalopathies
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