61 resultados para Repetitive DNAs


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Inheritance of three kinds of molecular genetic markers (mtDNA, random-amplified polymorphic DNAs (RAPDs) and allozymes) and sex were investigated in crossbreeding experiments between three populations of the Australian freshwater crayfish Cherax destructor. Crossbreeding did not disrupt the ively maternally inherited, and allozyme and RAPD markers were transmitted following expected Mendelian principles for co-dominant and dominant traits respectively. Unlike these three markers, sex ratios were found to be distorted by crossbreeding in some families. Two crossbred families produced only females. The implications of these findings for freshwater crayfish population genetics, taxonomy and aquaculture are discussed.


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The lack of attention to quality control by house builders has been a contentious issue for more than three decades. In an attempt to improve the quality of housing, various mechanisms have been adopted and discarded by industry-based organizations and government legislation. Now that registration of builders has been achieved (since 1995) the regulating authority, the Building Commission have placed the maintenance of standards from registered builders at the forefront of their priorities. The provision of suitable training and continuing professional development programs is likely to receive greater attention over the next few years. However, a key factor that is often overlooked in the debate on quality of house construction is the use of subcontract labour by both, registered builders and owner builders. The repetitive nature of some activities ensures that tacit knowledge within the subcontract system becomes an integral part of house construction. Research by the authors into defects in housing has provided some interesting analyses from the statistic collected. This paper analyses the incidence of defects over a number of years in a range of functional elements within the house envelope and presents the results. Particular attention is paid to the incidence of defects where the licensed trades are involved compared to the non-licensed trades and elements. This work suggests where housing defects are likely to occur and the authors suggest that appropriate educational resources may be directed to areas where it will be most effective and beneficial. The authors propose a more integrated and inclusive approach.

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The reductive voltammetry of the photovoltaic sensitizer [(H2-dcbpy)2Ru(NCS)2] (H2-dcbpy=2,2′-bipyridine-4,4′-dicarboxylic acid) and [(H3-tctpy)Ru(NCS)3]− (H3-tctpy=2,2′:6′,2″-terpyridine-4,4′,4″-tricarboxylic acid) has been investigated in acetone. Significant surface interactions at both platinum and glassy carbon electrodes occur at 0.6 V prior to the reversible potential expected for ligand-based reduction process of the fully protonated acids. The origin of the surface interactions are attributed to the acid–base behaviour of the compounds, combined with overall deprotonation and reduction to hydrogen, since repetitive cycling of the potential reveals well-defined reversible reduction processes in the negative potential range, resulting from formation of doubly deprotonated [(H-dcbpy−)2Ru(NCS)2]2− and singly deprotonated [(H2-tctpy−)Ru(NCS)3]2−, respectively. The extent of the surface interactions has been estimated by electrochemical quartz crystal microbalance and chronocoulometric measurements. Under certain conditions, a thick conducting polymer consisting of several hundred monolayers is formed.

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Granulocyte colony-stimulating factor (G-CSF) is the major regulator of neutrophil production. Studies in cell lines have established that conserved tyrosines Y704, Y729, Y744, Y764 within the cytoplasmic domain of G-CSF receptor (G-CSF-R) contribute significantly to G-CSF-induced proliferation, differentiation and cell survival. However, it is unclear whether these tyrosines are equally important under more physiological conditions. Here, we investigated how individual G-CSF-R tyrosines affect G-CSF responses of primary myeloid progenitors. We generated GCSF- R deficient mice and transduced their bone marrow cells with tyrosine "null" mutant (mO), single tyrosine "add back" mutants or wild type (WT) receptors. G-CSFinduced responses were determined in primary colony assays, serial replatings and suspension cultures. We show that removal of all tyrosines had no major influence on primary colony growth. However, adding back Y764 strongly enhanced proliferativeresponses, which was reverted by inhibition of ERK activitity. Y729, which we found to be associated with the suppressor of cytokine signaling, SOCS3, had a negative effect on colony formation. After repetitive replatings, the clonogenic capacities of cells expressing mO gradually dropped compared to WT. The presence of Y729, but also Y704 and Y744, both involved in activation of STAT3, further reduced replating
efficiencies. Conversely, Y764 greatly elevated the clonogenic abilities of myeloid progenitors, resulting in a >104–fold increase of colony forming cells over mO after the fifth replating. These findings suggest that tyrosines in the cytoplasmic domain of G-CSF-R, although dispensable for G-CSF-induced colony growth, recruit signaling mechanisms that regulate the maintenance and outgrowth of myeloid progenitor cells.

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Tendon injuries account for a substantial proportion of overuse injuries in competitive and recreational sports participants, as well as in individuals whose jobs require repetitive activity. Overuse type injuries account for 30% to 50% of all sports injuries, and in many endurance and power sports tendon injuries are clearly the most frequent reason for interruptions to training and competition [1] . Because tendon problems are so common, and not easily managed, this issue of Clinics is devoted to them. This article aims to provide an understanding of the pathology underlying the conditions before outlining current evidence for clinical assessment and treatment of tendinopathies.

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Due to the repetitive and lengthy nature, automatic content-based summarization is essential to extract a more compact and interesting representation of sport video. State-of-the art approaches have confirmed that high-level semantic in sport video can be detected based on the occurrences of specific audio and visual features (also known as cinematic). However, most of them still rely heavily on manual investigation to construct the algorithms for highlight detection. Thus, the primary aim of this paper is to demonstrate how the statistics of cinematic features within play-break sequences can be used to less-subjectively construct highlight classification rules. To verify the effectiveness of our algorithms, we will present some experimental results using six AFL (Australian Football League) matches from different broadcasters. At this stage, we have successfully classified each play-break sequence into: goal, behind, mark, tackle, and non-highlight. These events are chosen since they are commonly used for broadcasted AFL highlights. The proposed algorithms have also been tested successfully with soccer video.

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Prismatic boron nitride nanorods have been grown on single crystal silicon substrates by mechanical ball-milling followed by annealing at 1300 °C. Growth takes place by rapid surface diffusion of BN molecules, and follows heterogeneous nucleation at catalytic particles of an Fe/Si alloy. Lattice imaging transmission electron microscopy studies reveal a central axial row of rather small truncated pyramidal nanovoids on each nanorod, surrounded by three basal planar BN domains which, with successive deposition of epitaxial layers adapt to the void geometry by crystallographic faceting. The bulk strain in the nanorods is taken up by the presence of what appear to be simple nanostacking faults in the external, near-surface domains which, like the nanovoids are regularly repetitive along the nanorod length. Growth terminates with a clear cuneiform tip for each nanorod. Lateral nanorod dimensions are essentially determined by the size of the catalytic particle, which remains as a foundation essentially responsible for base growth. Growth, structure, and dominating facets are shown to be consistent with a system which seeks lowest bulk and surface energies according to the well-known thermodynamics of the capillarity of solids.

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In the literacy classroom, students have few opportunities to use their literacy practices to contest narratives of race, class, gender and sexuality. Instead, extensive time is spent completing literacy activities associated with what “good” readers and writers do. Students’ literacy practices are often formulaic, repetitive, and serve classroom management strategies producing a mythic narrative of good literacy teaching. This paper introduces a queer literacy curriculum that poses pedagogy as a series of questions: What does being taught, what does knowledge do to students? How does knowledge become understood in the relationship between teacher/text and student? (Lusted, 1986) It emphasizes developing critical analyses of heterosexism, heteronormativity and normativity with the goal of helping students understand binary categories are not givens, rather social constructions we are often forced to perform (Butler, 1990) through available discourses. The paper highlights an interruption into the literacy curriculum where, through collective memory work, students investigated, analysed and contested the usually-not-noticed ways a small understanding of heterosexuality has come to structure their lives.

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Numerous empirical studies on knowledge management have examined the relative effectiveness of various enablers, such as organizational structure, technology, culture, managerial system and strategy for knowledge creation and sharing in organizations. While these studies play a critical role in helping us to appreciate the importance of organizational enablers in knowledge management, they have neglected to examine the possible effects of task complexity on the nature and efficacy of knowledge sharing. This study investigates how task complexity influences the mode and effectiveness of knowledge sharing among professional accountants in Malaysia. In particular, it highlights the relationships between different task dimensions and modes of knowledge sharing, and the impact of knowledge sharing on professional competency. This study adopts a process oriented approach based on Nonaka’s (1994) knowledge sharing model. This study reveals that task complexity is significantly related to knowledge sharing. Tasks carried out by professional accountants vary from repetitive or clearly-defined procedural tasks to unstructured tasks that required professional judgment and expertise for successful task performance. While professional accountants are generally keen to gain access to knowledge databases to source for possible task solutions, they are generally hesitant to share their tacit knowledge by transforming the knowledge into explicit form. The finding suggests that there may be cultural-related factors that inhibit sharing of one’s tacit  knowledge totally and completely. This study also shows the existence of a  significant relationship between knowledge sharing and professional  competency, suggesting that the importance of the internalization mode of  knowledge sharing in sustaining the competitive edge of professional  accountants.

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Attempts are under way to condense more than 70 pieces of federal, state and territory legislation on personal property securities (PPS) into a single Federal Act. The revised second draft of the PPS Bill 2008 was released in November calling for further public comments by December 2008. The aim of this article is to highlight some of the important instances where further intensive drafting is needed. It draws out some key issues that have not been addressed that may assist in further revising the bill. Overall, the author firmly believes that the bill is far from perfect, that much work is still needed to improve clarity and readability and to minimise any uncertainty in the use of certain terms that are repetitive and obsolete. The article concludes with some useful references that Australia could perhaps learn from the problems currently experienced in New Zealand under its own PPS Act.

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The ultrafiltration of whey solutions is a common feature of dairy processes. However, the frequent fouling of ultrafiltration membranes and the subsequent cleaning cycle significantly affect the economics of such a process. In this work, we investigated the effect of ultrasonics on the cleaning of whey-fouled membranes and examined the variables that influence this effect. Experiments were conducted using a small single sheet membrane unit that was immersed totally within an ultrasonic bath.

Results show that the use of ultrasonics enhances the flux recovery following fouling. The extent of flux recovery is independent of the length of sonication time and increases with ultrasonic power. The use of surfactants in combination with ultrasonic irradiation shows a synergistic effect, providing a better efficiency than either cleaning process alone. Repetitive use of ultrasonic cleaning over a 1 month period does not result in any significant change in the permeate flux of a cleaned membrane, indicating that the ultrasonic treatment does not appear to damage the membrane structure itself.

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Motor neurone disease (MND) is an uncommon neurodegenerative disease that is terminal and has an insidious onset. With no known cause or cure, the disease triggers progressive death of motor neurones that causes increasing difficulties with mobility, communication, breathing and nutrition. Most research focuses on the disease process, but little is known of the illness experience from the perspective of those diagnosed with the disease. The aim of this study was to explore what it is like to live with MND and how people with the disease negotiate with others to exercise choice over the way they live. A grounded theory methodology was used to explore the life world of people diagnosed and living with MND. Data were collected via in-depth interviews, their stories and photographs, poems and books participants identified as important and fieldnotes. The textual data were analysed using constant comparative analysis. The majority of participants experienced difficulty with verbal communication. Some invited a third person to interpret their speech and others used assistive technologies such as Lightwriters and computers. Analysis revealed three constructs that, together, told the story of the MND illness experience. First, was the “diagnosis story” that described the devastating process of repeated tests had on the participants, shattering their trust in the competence of the health care system. The second construct revealed the process of living with MND as cyclical and repetitive requiring constant decision-making to adapt to the ongoing changes connected with the disease. The core theme and basic social process of “maintaining personal integrity” evolved as the third construct. This process underpinned and explained participants’ decision-making. Finally a substantive theory was conceptualised as the illness experience: “maintaining personal integrity in the face of ongoing change and adaptation”. This theory illustrates that the basic social process of maintaining personal integrity is central to decision and choice making while living with MND. The findings have implications for people with MND, their carers, health professionals and service providers. Recommendations include improved counselling services for people at the time of diagnosis; the introduction of nurse specialists to support health professionals, people diagnosed with the disease and their families; open, accessible, realistic health and funding policies.

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This thesis comprises three studies aimed at examining viewers' responses to filmed violence. The first focused on habituation, the second desensitisation and the third compared the paradigms. Results indicated that several factors influence how an individual responds to filmed violence and provide some insight into the impact of repetitive exposure to media violence. The portfolio presents four case studies emphasising the difficulties for assessing risk and associated interventions in the client population of individuals found not guilty because of mental impairment. This as an area of fundamental discord between psychology and law.

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Parametric modelling is gaining in popularity as both a fabrication and design tool, but its application in the architectural design industry has not been widely explored. Parametric modelling has the ability to generate complex forms with intuitively reactive components, allowing designers to express and fabricate structures previously too laborious and geometrically complex to realise. This alIows designers to address a project at both the macro and micro levels of resolution in the governing control surface and the individual repetitive component. This two level modelling control, of component and overall surface, can allow designers to explore new types of form generation subject to parametric constraints. Shading screens have been selected as the focus for this paper and are used as a medium to explore form generation within a given set of functional parameters. Screens can have many applications in a building but for the purpose of the following case studies, lighting quality and passive sun control are the main functional requirement. A set of screen components have been designed within certain shading parameters to create a generic component that can automatically adapt to any given climatic conditions. These will then be applied to surfaces of varying degrees of geometric complexity to be analysed in their ability to correctly tessellate and create a unified screening array true to the lighting requirements placed on the generic component.

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A challenge in designing a RF MEMS switch is the determination of its parameters to satisfy the application requirements. Often this is done through a set of comprehensive time consuming simulations. This paper employs neural networks and develops a supervised learner that is capable of determining S11 parameter for a RF MEMS shunt switch. The inputs are the length its L and the height of its gap. The outputs are S11s for eight different frequency points from 0 to V band. The developed learner helps prevent repetitive simulations when designing the specified switch. Simulation results are presented.