263 research outputs found
Cloning and sequence analysis of cDNAs encoding the cytosolic precursors of subunits GapA and GapB of chloroplast glyceraldehyde-3-phosphate dehydrogenase from pea and spinach
Chloroplast glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is composed of two different subunits, GapA and GapB. cDNA clones containing the entire coding sequences of the cytosolic precursors for GapA from pea and for GapB from pea and spinach have been identified, sequenced and the derived amino acid sequences have been compared to the corresponding sequences from tobacco, maize and mustard. These comparisons show that GapB differs from GapA in about 20% of its amino acid residues and by the presence of a flexible and negatively charged C-terminal extension, possibly responsible for the observed association of the enzyme with chloroplast envelopes in vitro. This C-terminal extension (29 or 30 residues) may be susceptible to proteolytic cleavage thereby leading to a conversion of chloroplast GAPDH isoenzyme I into isoenzyme II. Evolutionary rate comparisons at the amino acid sequence level show that chloroplast GapA and GapB evolve roughly two-fold slower than their cytosolic counterpart GapC. GapA and GapB transit peptides evolve about 10 times faster than the corresponding mature subunits. They are relatively long (68 and 83 residues for pea GapA and spinach GapB respectively) and share a similar amino acid framework with other chloroplast transit peptides
Teaching literacy and language in a functioning Western Cape quintile one school : a grade one case study
Includes bibliographical references (leaves 89-94).The Progress in International Reading Literacy Study (PIRLS) provides compelling evidence that many learners fail to achieve at the required grade level in South African primary schools. Although there are various factors that might contribute to this, the teaching and classroom practices of the teacher must be regarded as a highly significant factor in learners? achievement.This dissertation examines the literacy and language pedagogy of a South African Grade one teacher, in a Quintile one school with a history of relatively good performance on the Grade three provincial systemic assessments. The study asks the question: How does a Grade one teacher of learners who are not proficient in the language of learning and teaching (LoLT), English, teach literacy in the first term in a high performing Quintile 1 school
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The Bodies We Write In: Reentry Women Narrate Embodied Experiences of Writing in Graduate Education
This inquiry project explores connections between mind and body in academic writing. What scholars, educators and researchers have noted about the inclusion of the body in academic study illuminates the challenges of understanding the relationship between the two. Using a framework shaped by embodiment and feminist criticality illuminates how the body is elided through schooling and educational systems, reaching a peak in higher education. An interdisciplinary review of the literature supports a broad consideration of embodiment and typical writing practices in academic settings.
To better understand the body as a source of knowledge, data construction is holistic, using an embodied methodology with women who reenter graduate school later in life. Mindful awareness of the body guides the relating of writing experiences, and methods are designed with an ethic of care for participants, a spirit of co-creation, and shared experience. A narrative approach to data is used to explore where and how embodiment appears in women’s stories about academic writing.
The research process reflects a time of social separation within a pandemic. By better understanding women’s embodied experiences, this project seeks to enrich and enliven the way institutions of graduate study understand writing as an embodied practice and to honor what the body knows alongside the mind
Messung des ambulanten Bewegungsprofils bei Parkinsonpatienten in späten Krankheitsstadien - Zeigen sich Unterschiede zwischen kognitiven Subtypen?
Im Verlauf der Parkinson Erkrankung (PD) ist die Entwicklung einer Parkinsondemenz (PDD) häufig. Im Hinblick auf therapeutische Möglichkeiten ist die frühe Diagnosestellung der PDD wichtig. Für die Differenzialdiagnostik zwischen der PDD und dem Vorstadium PD-MCI (PD mit leichter kognitiver Beeinträchtigung) ist entscheidend, ob kognitiv bedingte Beeinträchtigungen der Aktivitäten des täglichen Lebens (ADL) vorliegen. Für diese Beurteilung werden vorrangig Angaben von den Patienten und deren Angehörigen herangezogen. Diese subjektiven Einschätzungen können jedoch ungenau sein und lassen nur eingeschränkt auf die zugrunde liegenden Ursachen der Verhaltensänderungen schließen. Die vorhandenen objektiven Testmethoden sind jedoch zeit- und kostenintensiv und wenig verbreitet. Die Anwendung von Bewegungssensoren stellt eine neue, kostengünstige und objektive Methode dar, das Bewegungsprofil von Patienten im häuslichen Umfeld über einen längeren Zeitraum zu erfassen. Da epidemiologische Studien bei älteren Probanden einen Zusammenhang zwischen der ADL-Funktion und dem Bewegungsprofil aufzeigen konnten, stellt sich die Frage nach dem Potential dieser Methode für die Differenzialdiagnostik der PDD. Über das objektiv gemessene ambulante Bewegungsprofil von kognitiv eingeschränkten PD Patienten gibt es jedoch bislang kaum Erkenntnisse. Die hier vorgestellte Pilotstudie untersuchte, ob sich das objektiv gemessene Bewegungsprofil zwischen PD Patienten mit beeinträchtigten ADL-Funktionen (PDD) im Vergleich zu den anderen kognitiven Subgruppen PD-MCI und PD ohne kognitive Beeinträchtigung (PD-NC) unterscheidet. Zur Validierung des Bewegungssensors wurde in einem ersten Schritt untersucht, ob sich das Bewegungsprofil aller PD Patienten (PD Total) von dem Bewegungsprofil von älteren Personen ohne neurodegenerative Erkrankung (Kontrollpersonen, KO) in den in der Literatur beschrieben Charakteristika unterscheidet. Insgesamt nahmen 55 PD Patienten und 18 Kontrollpersonen an dieser Studie teil. Basierend auf einer neuropsychologischen Testung und einem personalisierten Interview zur Beurteilung der ADL wurden die Patienten einer der drei kognitiven Subgruppen (PDD, PD-MCI und PD-NC) zugeordnet. Neben den demographischen Charakteristika wurden der motorische Schweregrad der PD und die depressive Symptomatik erfasst. Alle Probanden trugen den ambulanten Bewegungssensor (Dynaport Minimod®) für maximal 3 Tage. Messungen wurden ausgeschlossen (komplett oder einzelne Messtage), sofern die registrierte Messzeit 0.05). Die bisherigen Erkenntnisse zum ambulanten Bewegungsprofil von PD Patienten konnten bestätigt und ergänzt werden: Die PD Patienten zeigten ein inaktiveres Bewegungsprofil (P < 0.05) und unterschieden sich in einzelnen Parametern des zeitlichen Verteilungsmusters des aktiven physischen Verhaltens von den Kontrollpersonen (P<0.05). Der Vergleich der kognitiven Subgruppen ergab Hinweise darauf, dass Parameter des zeitlichen Verteilungsmusters von inaktivem physischen Verhalten die PDD Gruppe von den anderen kognitiven Subgruppen abgrenzte: Patienten saßen weniger oft aber dafür verweilten sie jeweils länger in dieser sitzenden Position (P < 0.05). In dieser Arbeit wurde erstmalig das ambulante Bewegungsprofil von PDD Patienten untersucht. Unsere Ergebnisse belegen, dass der Bewegungssensor auch in späten PD Stadien angewendet werden kann. Als unterscheidendes Merkmal zwischen PD-MCI (ohne ADL-Beeinträchtigung) und PDD (mit ADL-Beeinträchtigung) wurde das Verteilungsmuster des Sitzverhaltens identifiziert. Im Gegensatz zu dem vermindertem Volumen aktiver physischer Verhaltensweisen und der geringeren Intensität des Bewegungsprofils, die sich bei PD Patienten im Allgemeinen zeigen, deuten unsere Ergebnisse darauf hin, dass das Verteilungsmuster des inaktiven physischen Verhaltens den kognitiven ADL-Aspekt, also die seltenere Initiierung von neuen Handlungsabläufen, wiederspiegelt. Durch die objektive Abbildung dieser kognitiv bedingten ADL-Beeinträchtigung könnte die untersuchte Methode die Differenzialdiagnostik der PDD verbessern und somit frühere Interventionen ermöglichen
In situ magnetic separation of antibody fragments from Escherichia coli in complex media.
BACKGROUND: In situ magnetic separation (ISMS) has emerged as a powerful tool to overcome process constraints such as product degradation or inhibition of target production. In the present work, an integrated ISMS process was established for the production of his-tagged single chain fragment variable (scFv) D1.3 antibodies ("D1.3") produced by E. coli in complex media. This study investigates the impact of ISMS on the overall product yield as well as its biocompatibility with the bioprocess when metal-chelate and triazine-functionalized magnetic beads were used. RESULTS: Both particle systems are well suited for separation of D1.3 during cultivation. While the triazine beads did not negatively impact the bioprocess, the application of metal-chelate particles caused leakage of divalent copper ions in the medium. After the ISMS step, elevated copper concentrations above 120 mg/L in the medium negatively influenced D1.3 production. Due to the stable nature of the model protein scFv D1.3 in the biosuspension, the application of ISMS could not increase the overall D1.3 yield as was shown by simulation and experiments. CONCLUSIONS: We could demonstrate that triazine-functionalized beads are a suitable low-cost alternative to selectively adsorb D1.3 fragments, and measured maximum loads of 0.08 g D1.3 per g of beads. Although copper-loaded metal-chelate beads did adsorb his-tagged D1.3 well during cultivation, this particle system must be optimized by minimizing metal leakage from the beads in order to avoid negative inhibitory effects on growth of the microorganisms and target production. Hereby, other types of metal chelate complexes should be tested to demonstrate biocompatibility. Such optimized particle systems can be regarded as ISMS platform technology, especially for the production of antibodies and their fragments with low stability in the medium. The proposed model can be applied to design future ISMS experiments in order to maximize the overall product yield while the amount of particles being used is minimized as well as the number of required ISMS steps
A review of the processes associated with the removal of oil in water pollution
Water plays an essential role in production and refining processes. Many industries that
use petrochemicals also require water, especially for cleaning purposes. The wastewaters released
by these processes are often rich in petroleum pollutants, which requires significant treatment prior
to disposal. The presence of petroleum contaminants in rivers and oceans is a significant threat
to human health, as well as to many animal species. A current challenge for most industries and
conventional effluent treatment plants is compliance with accepted disposal standards for oil-polluted
wastewater. Of particular importance is the processing of dispersed oil in water, as well as oil in water
emulsion. Conventional oil and water separation methods for processing oil in water contamination
have several technology gaps in terms of applicability and efficiency. The removal and effective
processing of dispersed oil and emulsions from oily wastewater is a costly and significant problem.
The objective of this paper is to provide a review of the principles associated with oil in water
emulsion separation, with the aim of providing a more definitive understanding of the terminology,
processes, and methodologies, which will assist the development of a more efficient, innovative and
environmentally friendly process for the separation of oily wastewater
Managing Dynamic User Communities in a Grid of Autonomous Resources
One of the fundamental concepts in Grid computing is the creation of Virtual
Organizations (VO's): a set of resource consumers and providers that join
forces to solve a common problem. Typical examples of Virtual Organizations
include collaborations formed around the Large Hadron Collider (LHC)
experiments. To date, Grid computing has been applied on a relatively small
scale, linking dozens of users to a dozen resources, and management of these
VO's was a largely manual operation. With the advance of large collaboration,
linking more than 10000 users with a 1000 sites in 150 counties, a
comprehensive, automated management system is required. It should be simple
enough not to deter users, while at the same time ensuring local site autonomy.
The VO Management Service (VOMS), developed by the EU DataGrid and DataTAG
projects[1, 2], is a secured system for managing authorization for users and
resources in virtual organizations. It extends the existing Grid Security
Infrastructure[3] architecture with embedded VO affiliation assertions that can
be independently verified by all VO members and resource providers. Within the
EU DataGrid project, Grid services for job submission, file- and database
access are being equipped with fine- grained authorization systems that take VO
membership into account. These also give resource owners the ability to ensure
site security and enforce local access policies. This paper will describe the
EU DataGrid security architecture, the VO membership service and the local site
enforcement mechanisms Local Centre Authorization Service (LCAS), Local
Credential Mapping Service(LCMAPS) and the Java Trust and Authorization
Manager.Comment: Talk from the 2003 Computing in High Energy and Nuclear Physics
(CHEP03), La Jolla, Ca, USA, March 2003, 7 pages, LaTeX, 5 eps figures. PSN
TUBT00
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