6,844 research outputs found

    Recognition of abasic sites and single base bulges in DNA by a metalloinsertor

    Get PDF
    Abasic sites and single base bulges are thermodynamically destabilizing DNA defects that can lead to cancerous transformations if left unrepaired by the cell. Here we discuss the binding properties with abasic sites and single base bulges of Rh(bpy)_2(chrysi)^(3+), a complex previously shown to bind thermodynamically destabilized mismatch sites via metalloinsertion. Photocleavage experiments show that Rh(bpy)_2(chrysi)^(3+) selectively binds abasic sites with affinities of 1−4 × 10^6 M^(−1); specific binding is independent of unpaired base identity but is somewhat contingent on sequence context. Single base bulges are also selectively bound and cleaved, but in this case, the association constants are significantly lower (~10^5 M^(−1)), and the binding is dependent on both unpaired base identity and bulge sequence context. A wide variety of evidence, including strand scission asymmetry, binding enantiospecificity, and MALDI-TOF cleavage fragment analysis, suggests that Rh(bpy)_2(chrysi)^(3+) binds abasic sites, like mismatches, through insertion of the bulky chrysi ligand into the base pair stack from the minor groove side and ejection of the unpaired base. At single base bulge sites, a similar, though not identical, metalloinsertion mode is suggested. The recognition of abasic sites and single base bulges with bulky metalloinsertors holds promise for diagnostic and therapeutic applications

    A Dose of Reality: Overcoming Usability Challenges in VR Head-Mounted Displays

    Get PDF
    We identify usability challenges facing consumers adopting Virtual Reality (VR) head-mounted displays (HMDs) in a survey of 108 VR HMD users. Users reported significant issues in interacting with, and being aware of their real-world context when using a HMD. Building upon existing work on blending real and virtual environments, we performed three design studies to address these usability concerns. In a typing study, we show that augmenting VR with a view of reality significantly corrected the performance impairment of typing in VR. We then investigated how much reality should be incorporated and when, so as to preserve users’ sense of presence in VR. For interaction with objects and peripherals, we found that selectively presenting reality as users engaged with it was optimal in terms of performance and users’ sense of presence. Finally, we investigated how this selective, engagement-dependent approach could be applied in social environments, to support the user’s awareness of the proximity and presence of others

    Aspects of management options for pasture-based dairy production stocked at two cows per hectare

    Get PDF
    End of project reportWhite clover in association with Rhizobium bacteria have the capacity to fix or convent atmospheric N into plant available N. This can make a considerable contribution to sward productivity. One of the objectives of this experiment was to determine the upper carrying capacity of grass-white clover swards receiving 90 kg fertilizer N/ha. A second objective was to examine the impact of grass-clover swards on mineral-N in the soil and losses of nitrate-N from soil to drainage water during the winter. This experiment was conducted at Solohead Research Farm. There were three treatments: (i) A grass-only treatment (FN) stocked at 2.0 cows per ha in 2003 and 2.2 cows per ha during 2004, 2005 and 2006. This treatment received an average of 226 kg per ha of fertilizer N per year during these years. (ii) A grass-clover treatment (WC) stocked at the same rates as FN and received an average of 90 kg per ha of fertilizer N per year during the experiment. (iii) A grass-only treatment (CC) that was gradually converted over to grass-clover during the experiment and stocked at 2.0 cows per ha throughout the experiment. Fertilizer N input was gradually lowered from 150 kg per ha in 2003 to a target of 90 kg per ha in 2005 and 2006

    An Analysis of the 2002 Farm Bill’s Value-Added Producer Grants Program

    Get PDF
    Our objective is to identify the determinants for success among USDA’s Value- Added Producer Grants (VAPG) program recipients. Business development has become an important program in departments of agricultural economics. Market share was found to be an important determinant of VAPG success. Size variables including greater sales and increased grant dollars, as well as a lower number of producers, were also determinants of business success. Departments of agricultural economics are likely best able to assist VAPG recipients by providing information on price discovery, explaining their relationship to potential plant location, and providing education on best management practices to help producers avoid costly mistakes.agribusiness, business development, value-added, Agribusiness, Financial Economics, Productivity Analysis,

    Autonomy, evidence and intuition: nurses and decision-making

    Get PDF
    Aim: This paper is a report of a study conducted to examine how nurses represent professional clinical decision-making processes, and to determine what light Jamous and Peloille’s ‘Indeterminacy/Technicality ratio’ concept can shed on these representations. Background: Classic definitions of professional work feature autonomy of decision-making and control over the field of work. Sociologists Jamous and Peloille have described professional work as being high in ‘indeterminacy’ (the use of tacit judgements) relative to technicality (activity able to be codified). The rise of the evidence-based practice movement has been seen as increasing the realm of technical decision-making in healthcare, and it is relevant to analyse nurses’ professional discourse and study how they respond to this increase. Method: Three focus groups with qualified nurses attending post-qualifying courses at a London university were held in 2008. Participants were asked to talk about influences on their decision-making. The discussions were tape-recorded, transcribed, and subjected to discourse analysis. Findings: Participants described their decision-making as influenced by both indeterminate and technical features. They acknowledged useful influences from both domains, but pointed to their personal ‘experience’ as the final arbiter of decision-making. Their accounts of decision-making created a sense of professional autonomy while at the same time protecting it against external critique. Conclusion: Pre- and post-registration nurse education could encourage robust discussion of the definition and roles of ‘irrational’ aspects of decision-making and how these might be understood as components of credible professional practice

    Professional autonomy in 21st century healthcare: nurses’ accounts of clinical decision-making

    Get PDF
    Autonomy in decision-making has traditionally been described as a feature of professional work, however the work of healthcare professionals has been seen as steadily encroached upon by State and managerialist forces. Nursing has faced particular problems in establishing itself as a credible profession for reasons including history, gender and a traditional subservience to medicine. This paper reports on a focus group study of UK nurses participating in post-qualifying professional development in a London university in 2008. Three groups of nurses in different specialist areas comprised a total of 26 participants. The study uses accounts of decision-making to gain insight into contemporary professional nursing. The study also aims to explore the usefulness of a theory of professional work set out by Jamous and Peloille in 1970. The analysis draws on notions of interpretive repertoires and elements of narrative analysis. We identified two interpretive repertoires: ‘clinical judgement’ which was used to describe the different grounds for making judgements; and ‘decision-making’ which was used to describe organisational circumstances influencing decision-making. Jamous and Peloille’s theory proved useful for interpreting instances where the nurses collectively withdrew from the potential dangers of too extreme claims for technicality or indeterminacy in their work. However, their theory did not explain the full range of accounts of decision-making that were given. Taken at face value, the accounts from the participants depict nurses as sometimes practising in indirect ways in order to have influence in the clinical and bureaucratic setting. However, a focus on language use and in particular, interpretive repertoires, has enabled us to suggest that despite an overall picture of severely limited autonomy, nurses in the groups reproduced stories of the successful accomplishment of moral and influential action

    CHARACTERISTICS OF MASTER'S PROGRAMS IN AGRIBUSINESS MANAGEMENT

    Get PDF
    This study describes and compares agribusiness master’s programs in North America. These programs include the master of business administration (MBA) and master in (or “of”) agribusiness (MAB) degrees. Accredited MBA programs with an agribusiness emphasis are required to have a clear required core of courses in finance, management, marketing management, and human behavior. Additional required courses in policy, agricultural marketing, production or managerial economics, and quantitative methods are also frequently required. MAB programs have more diversity regarding the four core subjects with a greater percentage of the courses taught within departments of agricultural economics. Evaluation of agribusiness master’s programs in agricultural economics departments is difficult without any formal evaluation criteria.Agribusiness, Teaching/Communication/Extension/Profession,

    Implementing a Biblical Vision for Education: Challenges Facing Leaders from Primary Campuses of Christian Schools in Sydney, Australia

    Get PDF
    This article outlines the results of a recent study that investigated the challenges primary department leaders in Christian schools in Sydney are faced with as they seek to implement a biblical vision for education, along with strategies used to overcome the challenges. Competing Priorities was found to be the central challenge facing Christian school leaders as they seek to implement a biblical vision for education. Others identified include: Governance Issues, Changed Parent Expectations, Commodification of Education, Dealing with Conflicts and Human Resource Management Issues. With consideration of the challenges faced by Christian school leaders, the paper highlights a number of key strategies found in the study. These could be critically effective in assisting educators to help overcome the current problem facing Christian schools, that their ideologies are being challenged due to a rise in secularism in Australia, and assist them as they implement a biblical vision for education in their school. The results were displayed diagrammatically
    corecore