205 research outputs found

    Protein-mediated dethreading of a biotin-functionalised pseudorotaxane

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    In this article, we describe the synthesis of new biotin-functionalised naphthalene derivatives 3 and 4 and their complexation behaviour with avidin and neutravidin using a range of analytical techniques. We have shown using 2-(4prime or minute-hydroxyazobenzene)benzoic acid displacement and ITC experiments{,} that compounds 3 and 4 have the propensity to form reasonably high-affinity bioconjugates with avidin and neutravidin. We have also demonstrated using 1H NMR{,} UV-vis and fluorescence spectroscopy that the naphthalene moiety of 3 and 4 facilitates the formation of pseudorotaxane-like structures with 1 in water. We have then investigated the ability of avidin and neutravidin to modulate the complexation between 1 and 3 or 4. UV-vis and fluorescence spectroscopy has shown that in both cases the addition of the protein disrupts complexation between the naphthalene moieties of 3 and 4 with 1

    Hole depletion and localization due to disorder in insulating PrBa2Cu3O7-d: a Compton scattering study

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    The (mostly) insulating behaviour of PrBa2Cu3O7-d is still unexplained and even more interesting since the occasional appearance of superconductivity in this material. Since YBa2Cu3O7-d is nominally iso-structural and always superconducting, we have measured the electron momentum density in these materials. We find that they differ in a striking way, the wavefunction coherence length in PrBa2Cu3O7-d being strongly suppressed. We conclude that Pr on Ba-site substitution disorder is responsible for the metal-insulator transition. Preliminary efforts at growth with a method to prevent disorder yield 90K superconducting PrBa2Cu3O7-d crystallites.Comment: 4 pages, 3 figures, revised version submitted to PR

    Ab initio calculation of the neutron-proton mass difference

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    The existence and stability of atoms rely on the fact that neutrons are more massive than protons. The measured mass difference is only 0.14\% of the average of the two masses. A slightly smaller or larger value would have led to a dramatically different universe. Here, we show that this difference results from the competition between electromagnetic and mass isospin breaking effects. We performed lattice quantum-chromodynamics and quantum-electrodynamics computations with four nondegenerate Wilson fermion flavors and computed the neutron-proton mass-splitting with an accuracy of 300300 kilo-electron volts, which is greater than 00 by 55 standard deviations. We also determine the splittings in the Σ\Sigma, Ξ\Xi, DD and Ξcc\Xi_{cc} isospin multiplets, exceeding in some cases the precision of experimental measurements.Comment: 57 pages, 15 figures, 6 tables, revised versio

    The utilisation of health research in policy-making: Concepts, examples and methods of assessment

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    The importance of health research utilisation in policy-making, and of understanding the mechanisms involved, is increasingly recognised. Recent reports calling for more resources to improve health in developing countries, and global pressures for accountability, draw greater attention to research-informed policy-making. Key utilisation issues have been described for at least twenty years, but the growing focus on health research systems creates additional dimensions. The utilisation of health research in policy-making should contribute to policies that may eventually lead to desired outcomes, including health gains. In this article, exploration of these issues is combined with a review of various forms of policy-making. When this is linked to analysis of different types of health research, it assists in building a comprehensive account of the diverse meanings of research utilisation. Previous studies report methods and conceptual frameworks that have been applied, if with varying degrees of success, to record utilisation in policy-making. These studies reveal various examples of research impact within a general picture of underutilisation. Factors potentially enhancing utilisation can be identified by exploration of: priority setting; activities of the health research system at the interface between research and policy-making; and the role of the recipients, or 'receptors', of health research. An interfaces and receptors model provides a framework for analysis. Recommendations about possible methods for assessing health research utilisation follow identification of the purposes of such assessments. Our conclusion is that research utilisation can be better understood, and enhanced, by developing assessment methods informed by conceptual analysis and review of previous studies

    An assessment of opportunities and challenges for public sector involvement in the maternal health voucher program in Uganda

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    This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Background: Continued inequities in coverage, low quality of care, and high out-of-pocket expenses for health services threaten attainment of Millennium Development Goals 4 and 5 in many sub-Saharan African countries. Existing health systems largely rely on input-based supply mechanisms that have a poor track record meeting the reproductive health needs of low-income and underserved segments of national populations. As a result, there is increased interest in and experimentation with results-based mechanisms like supply-side performance incentives to providers and demand-side vouchers that place purchasing power in the hands of low-income consumers to improve uptake of facility services and reduce the burden of out-of-pocket expenditures. This paper describes a reproductive health voucher program that contracts private facilities in Uganda and explores the policy and implementation issues associated with expansion of the program to include public sector facilities. Methods: Data presented here describes the results of interviews of six district health officers and four health facility managers purposefully selected from seven districts with the voucher program in southwestern Uganda. Interviews were transcribed and organized thematically, barriers to seeking RH care were identified, and how to address the barriers in a context where voucher coverage is incomplete as well as opportunities and challenges for expanding the program by involving public sector facilities were investigated. Results: The findings show that access to sexual and reproductive health services in southwestern Uganda is constrained by both facility and individual level factors which can be addressed by inclusion of the public facilities in the program. This will widen the geographical reach of facilities for potential clients, effectively addressing distance related barriers to access of health care services. Further, intensifying ongoing health education, continuous monitoring and evaluation, and integrating the voucher program with other services is likely to address some of the barriers. The public sector facilities were also seen as being well positioned to provide voucher services because of their countrywide reach, enhanced infrastructure, and referral networks. The voucher program also has the potential to address public sector constraints such as understaffing and supply shortages.Conclusions: Accrediting public facilities has the potential to increase voucher program coverage by reaching a wider pool of poor mothers, shortening distance to service, strengthening linkages between public and private sectors through public-private partnerships and referral systems as well as ensuring the awareness and buy-in of policy makers, which is crucial for mobilization of resources to support the sustainability of the programs. Specifically, identifying policy champions and consulting with key policy sectors is key to the successful inclusion of the public sector into the voucher program

    Participants\u27 perceptions of a knowledge-brokering strategy to facilitate evidence-informed policy-making in Fiji

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    BACKGROUND: Evidence-informed policy-making (EIPM) is optimal when evidence-producers (researchers) and policy developers work collaboratively to ensure the production and use of the best available evidence. This paper examined participants’ perceptions of knowledge-brokering strategies used in the TROPIC (Translational Research in Obesity Prevention in Communities) project to facilitate the use of obesity-related evidence in policy development in Fiji. METHOD: Knowledge-brokers delivered a 12-18 month programme comprising workshops targeting EIPM skills and practical support for developing evidence-informed policy briefs to reduce obesity. The programme was tailored to each of the six participating organizations. Knowledge-brokering strategies included negotiating topics that were aligned to the goals of individual organizations, monitoring and evaluating time-management skills, accommodating other organizational and individual priorities, delivering practical sessions on use of appropriate research tools and supporting individual writing of policy briefs. Two qualitative methods were used to examine individuals’ perceptions of skills obtained, opportunities afforded by the TROPIC project, facilitators and inhibiters to planned policy brief development and suggestions for improved programme delivery. Forty-nine participants completed an electronic word table and then participated in a semi-structured interview. An independent interviewer conducted structured interviews with a high-ranking officer in each organization to examine their perceptions of TROPIC engagement strategies. Data were analyzed descriptively and thematically, with the first author and another experienced qualitative researcher analyzing data sets separately, and then combining analyses. RESULTS: Many participants believed that they had increased their skills in acquiring, assessing, adapting and applying evidence, writing policy briefs and presenting evidence-based arguments to higher levels. Many participants preferred one-to-one meetings to group activities to ensure early resolution of developing issues and to refine policy briefs. Perceived barriers to EIPM were lack of knowledge about data sources, inadequate time to develop evidence-informed briefs, and insufficient resources for accessing and managing evidence. CONCLUSION: An innovative knowledge-brokering approach utilizing skill development and mentorship facilitated individual EIPM skills and policy brief development. The TROPIC model could stimulate evidence-based policy action relating to obesity prevention and other policy areas in other Pacific countries and elsewhere

    EMMIE and engineering: What works as evidence to improve decisions?

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    While written by a proponent of realism, this article argues in favour of a pragmatic approach to evaluation. It argues that multiple sources of evidence collected using diverse research methods can be useful in conducting informative evaluations of programmes, practices and policies. It argues in particular that methods, even if their assumptions appear incommensurable with one another, should be chosen to meet the evidence needs of decision-makers. These evidence needs are captured in the acronym, EMMIE, which refers to Effect size, Mechanism, Moderator (or context), Implementation and Economic impact. Finally the article questions evidence hierarchies that are inspired by clinical trials, and suggests instead that, notwithstanding the clear differences in the physical and social worlds, engineering may provide a superior model for evaluators to try to emulate. And engineering is, above all, a pragmatic field

    Процесс анализа угроз, влияющих на экономическую устойчивость предприятия

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    На основании проведенного исследования были выявлены факторы возникновения угроз, их группировка по степени воздействию на экономическую устойчивость предприятий и рассмотрена формализация процесса анализа угроз экономической устойчивости предприятий. В условиях рыночной экономики невозможно управлять предприятием без учета влияния угроз, а для эффективного управления важно не только знать об их присутствии, а и правильно идентифицировать конкретную угрозу.На підставі проведеного дослідження були виявлені чинники виникнення загроз, їх угруповання по степені впливу на економічну стійкість підприємств і розглянута формалізація процесу аналізу загроз економічної стійкості підприємств. В умовах ринкової економіки неможливо керувати підприємством без вивчення впливу загроз, а для ефективного керування важливо не тільки знати про їх присутність, а і правильно ідентифікувати конкретну загрозу.On the basis of the conducted research the factors of origin of threats were exposed, their gourmet on a degree to influence on economic stability of enterprises and formalization of process of analysis of threats of economic stability of enterprises is considered. In the conditions of market economy it is impossible to manage an enterprise without taking into account influencing of threats, and for the effective management it is important not only to know about their presence, and to identify the concrete threat correctly

    Appeals to evidence for the resolution of wicked problems: the origins and mechanisms of evidentiary bias

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    Wicked policy problems are often said to be characterized by their ‘intractability’, whereby appeals to evidence are unable to provide policy resolution. Advocates for ‘Evidence Based Policy’ (EBP) often lament these situations as representing the misuse of evidence for strategic ends, while critical policy studies authors counter that policy decisions are fundamentally about competing values, with the (blind) embrace of technical evidence depoliticizing political decisions. This paper aims to help resolve these conflicts and, in doing so, consider how to address this particular feature of problem wickedness. Specifically the paper delineates two forms of evidentiary bias that drive intractability, each of which is reflected by contrasting positions in the EBP debates: ‘technical bias’ - referring to invalid uses of evidence; and ‘issue bias’ - referring to how pieces of evidence direct policy agendas to particular concerns. Drawing on the fields of policy studies and cognitive psychology, the paper explores the ways in which competing interests and values manifest in these forms of bias, and shape evidence utilization through different mechanisms. The paper presents a conceptual framework reflecting on how the nature of policy problems in terms of their complexity, contestation, and polarization can help identify the potential origins and mechanisms of evidentiary bias leading to intractability in some wicked policy debates. The discussion reflects on whether being better informed about such mechanisms permit future work that may lead to strategies to mitigate or overcome such intractability in the future

    Preclinical pharmacokinetics and metabolism of a novel prototype DNA-PK inhibitor NU7026

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    In this study we investigated the in vitro time dependence of radiosensitisation, pharmacokinetics and metabolism of NU7026, a novel inhibitor of the DNA repair enzyme DNA-dependent protein kinase (DNA-PK). At a dose of 10 μM, which is nontoxic to cells per se, a minimum NU7026 exposure of 4 h in combination with 3 Gy radiation is required for a significant radiosensitisation effect in CH1 human ovarian cancer cells. Following intravenous administration to mice at 5 mg kg−1, NU7026 underwent rapid plasma clearance (0.108 l h−1) and this was largely attributed to extensive metabolism. Bioavailability following interperitoneal (i.p.) and p.o. administration at 20 mg kg−1 was 20 and 15%, respectively. Investigation of NU7026 metabolism profiles in plasma and urine indicated that the compound undergoes multiple hydroxylations. A glucuronide conjugate of a bis-hydroxylated metabolite represented the major excretion product in urine. Identification of the major oxidation site as C-2 of the morpholine ring was confirmed by the fact that the plasma clearance of NU7107 (an analogue of NU7026 methylated at C-2 and C-6 of the morpholine ring) was four-fold slower than that of NU7026. The pharmacokinetic simulations performed predict that NU7026 will have to be administered four times per day at 100 mg kg−1 i.p. in order to obtain the drug exposure required for radiosensitisation
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