106 research outputs found

    Development of a nationwide network for technology transfer

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    The winter and spring of 1987 saw the cooperative nationwide network for technology transfer translated from concept to reality. The most obvious of the network relationships which were developed or which are anticipated are summarized. The objective was to help assure that every U.S. business which has the capacity to exploit, or the need to obtain new technology in any form, has access to the technology it needs or can use

    Updating the Kentucky Contract Time Determination System

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    The Federal Highway Administration requires State Transportation Agencies to have a formal method to estimate contract time for highway construction projects. To meet this requirement many states use an integrated scheduling system to estimate project durations based on assumed productivity rates and generic job logic. The current work investigated the accuracy of two of these systems found that both systems accuracy in predicting the duration of Kentucky Transportation Cabinet projects was greater than +200%. In response to this poor accuracy, a parametric project duration estimating tool was developed based on a multivariate regression analysis of bid item quantities and engineering and construction estimate. Five regression models were develop to estimate contract time for large projects (great than 1,000,000)basedonkeybiditemquantities;limitedaccess(+221,000,000) based on key bid item quantities; limited access (+22% median error), open access (+35% median error), new route (+55% median error), bridge rehabilitation (+77% median error), and bridge replacement(+17% median error). It was not possible to develop a parametric estimating tool for predicting the duration of small projects (less than 1,000,000) as it appears that the duration of small projects is determined by factors outside of bid item quantities

    Varying efficacy of artesunate+amodiaquine and artesunate+sulphadoxine-pyrimethamine for the treatment of uncomplicated falciparum malaria in the Democratic Republic of Congo: a report of two in-vivo studies

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    BACKGROUND: Very few data on anti-malarial efficacy are available from the Democratic Republic of Congo (DRC). DRC changed its anti-malarial treatment policy to amodiaquine (AQ) and artesunate (AS) in 2005. METHODS: The results of two in vivo efficacy studies, which tested AQ and sulphadoxine-pyrimethamine (SP) monotherapies and AS+SP and AS+AQ combinations in Boende (Equatorial province), and AS+SP, AS+AQ and SP in Kabalo (Katanga province), between 2003 and 2004 are presented. The methodology followed the WHO 2003 protocol for assessing the efficacy of anti-malarials in areas of high transmission. RESULTS: Out of 394 included patients in Boende, the failure rates on day 28 after PCR-genotyping adjustment of AS+SP and AS+AQ were estimated as 24.6% [95% CI: 16.6-35.5] and 15.1% [95% CI: 8.6-25.7], respectively. For the monotherapies, failure rates were 35.9% [95% CI: 27.0-46.7] for SP and 18.3% [95% CI: 11.6-28.1] for AQ. Out of 207 patients enrolled in Kabalo, the failure rate on day 28 after PCR-genotyping adjustment was 0 [1-sided 95% CI: 5.8] for AS+SP and AS+AQ [1-sided 95% CI: 6.2]. It was 19.6% [95% CI: 11.4-32.7] for SP monotherapy. CONCLUSION: The finding of varying efficacy of the same combinations at two sites in one country highlights one difficulty of implementing a uniform national treatment policy in a large country. The poor efficacy of AS+AQ in Boende should alert the national programme to foci of resistance and emphasizes the need for systems for the prospective monitoring of treatment efficacy at sentinel sites in the country

    Efficacy of antimalarial treatment in Guinea: in vivo study of two artemisinin combination therapies in Dabola and molecular markers of resistance to sulphadoxine-pyrimethamine in N'Zérékoré

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    BACKGROUND: In the last five years, countries have been faced with changing their malaria treatment policy to an artemisinin-based combination therapy (ACT), many with no national data on which to base their decision. This is particularly true for a number of West African countries, including Guinea, where these studies were performed. Two studies were conducted in 2004/2005 in programmes supported by Medecins Sans Frontieres, when chloroquine was still national policy, but artesunate (AS)/sulphadoxine-pyrimethamine (SP) had been used in refugee camps for two years. METHODS: In Dabola (central Guinea), 220 children aged 6-59 months with falciparum malaria were randomized to receive either AS/amodiaquine (AQ) or AS/SP. In vivo efficacy was assessed following the 2003 World Health Organization guidelines. In a refugee camp in Laine (south of Guinea), where an in vivo study was not feasible due to the unstable context, a molecular genotyping study in 160 patients assessed the prevalence of mutations in the dihydrofolate reductase (dhfr) (codons 108, 51, 59) and dihydropteroate synthase (dhps) (codons 436, 437, 540) genes of Plasmodium falciparum, which have been associated with resistance to pyrimethamine and sulphadoxine, respectively. RESULTS: In Dabola, after 28 days of follow-up, Polymerase Chain Reaction (PCR)-adjusted failure rates were 1.0% (95%CI 0-5.3) for AS/AQ and 1.0% (95%CI 0-5.5) for AS/SP. In the refugee camp in Laine, the molecular genotyping study found three dhfr mutations in 85.6% (95%CI 79.2-90.7) patients and quintuple dhfr/dhps mutations in 9.6% (95%CI 5.2-15.9). CONCLUSION: Both AS/AQ and AS/SP are highly efficacious in Dabola, whereas there is molecular evidence of established SP resistance in Laine. This supports the choice of the national programme of Guinea to adopt AS/AQ as first line antimalarial treatment. The results highlight the difficulties faced by control programmes, which have gone through the upheaval of implementing ACTs, but cannot predict how long their therapeutic life will be, especially in countries which have chosen drugs also available as monotherapies

    Extreme genetic fragility of the HIV-1 capsid

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    Genetic robustness, or fragility, is defined as the ability, or lack thereof, of a biological entity to maintain function in the face of mutations. Viruses that replicate via RNA intermediates exhibit high mutation rates, and robustness should be particularly advantageous to them. The capsid (CA) domain of the HIV-1 Gag protein is under strong pressure to conserve functional roles in viral assembly, maturation, uncoating, and nuclear import. However, CA is also under strong immunological pressure to diversify. Therefore, it would be particularly advantageous for CA to evolve genetic robustness. To measure the genetic robustness of HIV-1 CA, we generated a library of single amino acid substitution mutants, encompassing almost half the residues in CA. Strikingly, we found HIV-1 CA to be the most genetically fragile protein that has been analyzed using such an approach, with 70% of mutations yielding replication-defective viruses. Although CA participates in several steps in HIV-1 replication, analysis of conditionally (temperature sensitive) and constitutively non-viable mutants revealed that the biological basis for its genetic fragility was primarily the need to coordinate the accurate and efficient assembly of mature virions. All mutations that exist in naturally occurring HIV-1 subtype B populations at a frequency >3%, and were also present in the mutant library, had fitness levels that were >40% of WT. However, a substantial fraction of mutations with high fitness did not occur in natural populations, suggesting another form of selection pressure limiting variation in vivo. Additionally, known protective CTL epitopes occurred preferentially in domains of the HIV-1 CA that were even more genetically fragile than HIV-1 CA as a whole. The extreme genetic fragility of HIV-1 CA may be one reason why cell-mediated immune responses to Gag correlate with better prognosis in HIV-1 infection, and suggests that CA is a good target for therapy and vaccination strategies

    High throughput methods applied in biomaterial development and discovery

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    The high throughput discovery of new materials can be achieved by rapidly screening many different materials synthesised by a combinatorial approach to identify the optimal material that fulfils a particular biomedical application. Here we review the literature in this area and conclude that for polymers, this process is best achieved in a microarray format, which enable thousands of cell-material interactions to be monitored on a single chip. Polymer microarrays can be formed by printing pre-synthesised polymers or by printing monomers onto the chip where on-slide polymerisation is initiated. The surface properties of the material can be analysed and correlated to the biological performance using high throughput surface analysis, including time-of-flight secondary ion mass spectrometry (ToF-SIMS), X-ray photoelectron spectroscopy (XPS) and water contact angle (WCA) measurements. This approach enables the surface properties responsible for the success of a material to be understood, which in turn provides the foundations of future material design. The high throughput discovery of materials using polymer microarrays has been explored for many cell-based applications including the isolation of specific cells from heterogeneous populations, the attachment and differentiation of stem cells and the controlled transfection of cells. Further development of polymerisation techniques and high throughput biological assays amenable to the polymer microarray format will broaden the combinatorial space and biological phenomenon that polymer microarrays can explore, and increase their efficacy. This will, in turn, result in the discovery of optimised polymeric materials for many biomaterial applications

    Genomewide Association Studies of LRRK2 Modifiers of Parkinson's Disease.

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    OBJECTIVE: The aim of this study was to search for genes/variants that modify the effect of LRRK2 mutations in terms of penetrance and age-at-onset of Parkinson's disease. METHODS: We performed the first genomewide association study of penetrance and age-at-onset of Parkinson's disease in LRRK2 mutation carriers (776 cases and 1,103 non-cases at their last evaluation). Cox proportional hazard models and linear mixed models were used to identify modifiers of penetrance and age-at-onset of LRRK2 mutations, respectively. We also investigated whether a polygenic risk score derived from a published genomewide association study of Parkinson's disease was able to explain variability in penetrance and age-at-onset in LRRK2 mutation carriers. RESULTS: A variant located in the intronic region of CORO1C on chromosome 12 (rs77395454; p value = 2.5E-08, beta = 1.27, SE = 0.23, risk allele: C) met genomewide significance for the penetrance model. Co-immunoprecipitation analyses of LRRK2 and CORO1C supported an interaction between these 2 proteins. A region on chromosome 3, within a previously reported linkage peak for Parkinson's disease susceptibility, showed suggestive associations in both models (penetrance top variant: p value = 1.1E-07; age-at-onset top variant: p value = 9.3E-07). A polygenic risk score derived from publicly available Parkinson's disease summary statistics was a significant predictor of penetrance, but not of age-at-onset. INTERPRETATION: This study suggests that variants within or near CORO1C may modify the penetrance of LRRK2 mutations. In addition, common Parkinson's disease associated variants collectively increase the penetrance of LRRK2 mutations. ANN NEUROL 2021;90:82-94

    Safety, immunogenicity, and reactogenicity of BNT162b2 and mRNA-1273 COVID-19 vaccines given as fourth-dose boosters following two doses of ChAdOx1 nCoV-19 or BNT162b2 and a third dose of BNT162b2 (COV-BOOST): a multicentre, blinded, phase 2, randomised trial

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