14,621 research outputs found

    Relación entre el islam y la ciencia:: De la armonía medieval al concordismo contemporáneo

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    The relationship between "reason and faith" or "science and religion" is articulated in Islam in a particular way by the fact that the Koran is interpreted as a revelation addressed to the intellect and by the splendour of the sciences during the golden age of this civilisation in the Middle Ages. After its collapse, with the challenge of the scientific rationalism of the 19th century and the apologetic intention of Islam, on the one hand, and of liberation against colonialism, Islamic reformism proposes a "return to reason" and science. However, a current of "scientific interpretation of the Koran" was born, which was more an Islamisation of science than a rationalisation of Islam.La relación entre “razón y fe” o “ciencia y religión” tiene una articulación particular en el islam por el hecho de que el Corán es interpretado como una revelación dirigida al intelecto y por el esplendor de las ciencias durante el período de oro de esta civilización en la Edad Media. Después de su derrumbamiento, con la interpelación del racionalismo científico del s.XIX y con la intencionalidad apologética del islam, por una parte, y de liberación contra el colonialismo, el reformismo islámico propone “volver a la razón” y a la ciencia. Sin embargo, nacerá una corriente de “interpretación científica del Corán” que será más bien una islamización de la ciencia y no una racionalización del islam

    Towards detection of structurally-diverse glycated epitopes in native proteins : single-chain antibody directed to non-A1c epitope in human haemoglobin

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    Over 500 million people worldwide are affected by diabetes mellitus, a chronic disease that leads to high blood glucose levels and causes severe side effects. The predominant biological marker for diagnosis of diabetes is glycated haemoglobin (GHb). In human blood the predominant reducing sugar, glucose, irreversibly conjugates onto accessible amine groups within Hb. Most methods for diagnosis and monitoring of diabetes selectively detect N-terminal glycation at Val-1 on the β-globin chain, but not glycation at other sites. Detection of other glycated epitopes of GHb has the potential to provide new information on the extent, duration and timing of elevated glucose, facilitating personalised diagnosis and intelligent diabetic control. In this work, a new anti-GHb Fab antibody (Fab-1) specific for haemoglobin A1c (HbA1c) with nanomolar affinity was discovered via epitope-directed immunisation and phage display. A single chain variable fragment (scFv) antibody derived from Fab-1 retained affinity and specificity for HbA1c, and affinity was enhanced tenfold upon addition of an enhanced green fluorescent protein tag. Both the scFv and Fab-1 recognised an epitope within HbA1c that was distinct from β-Val-1, and our data suggest that this epitope may include glycation at Lys-66 in the β-globin chain. To our knowledge, this is the first report of an scFv/Fab anti-glycated epitope antibody that recognises a non-A1c epitope in GHb, and confirms that fructosamine attached to different, discrete glycation sites within the same protein can be resolved from one another by immunoassay. [Abstract copyright: Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.

    Viability of calcinated wastepaper sludge ash geopolymer in the treatment of road pavement subgrade materials

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    Problematic ground conditions constituted by weak or expansive clays are commonly encountered in construction projects and require some form of chemical treatment such as lime and cement to re-engineer their performance. However, in the light of the adverse effects of these traditional additives on the climate, alternative eco-friendlier materials are now sourced. In the current study, the viability of calcinated wastepaper sludge ash geopolymer in enhancing the engineering behaviour of a problematic site condition is evaluated. A highly expansive clay (HEC) constituted with a blend of kaolinite and bentonite clays is treated with calcinated wastepaper sludge ash (CPSA) geopolymer. Activation of the precursor is actualised at room temperature using a combination of NaOH and Na2SiO3 at various activator to soil+binder ratios (AL/P), and molarity (M). The mechanical, microstructural, and mineralogical characteristics of the treated clay were investigated through unconfined compressive strength (UCS), swell, water absorption, SEM, and EDX analysis. The performance of the stabilised samples was then compared with the requirements for road subgrade and subbase materials and that of OPC and lime-GGBS treatment. The results showed that CPSA-geopolymer enhanced the engineering properties of the treated clay better than traditional binders (OPC and Iime-GGBS). UCS improvement of 220% was observed in the CPSA-stabilised soil over that of OPC-treated ones, while the swell potential and water absorption were drastically reduced by over 95 and 97% respectively after 28-day soaking. The SEM and EDX results showed improved crystallisation of earth-metal-based cementitious flakes (NASH) with increasing CPSA, molarity, and AL/P ratios, which enhanced the inter-particle bonds with simultaneous reduction in porosity. The modified characteristics of the stabilised materials meet the requirements for pavement subgrades. Further, the equivalent carbon emission (CO2-e) from the stabilised materials were also evaluated and compared with that of traditional binders. The results also showed that CPSA-geopolymer had lower CO2-e at higher subgrade strengths than OPC, making it more eco-friendly. Therefore, wastepaper sludge, a common landfill waste from paper recycling is a viable geopolymer precursor that could be utilised in enhancing the engineering properties of subgrade and sub-base materials for road and foundation construction

    First-principles calculations of anharmonic phonons in diamond and silicon at high temperature and pressure

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    Many ab initio approaches for calculating anharmonic phonon dispersion relations have recently been developed, taking advantage of improvements in computational power. In this thesis, anharmonic phonons in the diamond-type semiconductors silicon and diamond are studied using two of these recently developed ab initio techniques to better understand the role of anharmonicity in these materials at elevated temperatures and pressures. The two techniques are the self-consistent phonon method as implemented in the alamode code and the temperature dependent effective potential approach implemented in the TDEP code. Both these approaches rely on density functional theory calculations to compute anharmonic phonon frequencies from first principles. The renormalisation of the zone-centre optical phonon of silicon is calculated using both methods. The TDEP approach accurately reproduces the experimentally observed temperature dependence of the zone-centre phonon, whereas alamode underestimates the renormalisation. This underestimation is determined to originate from the exclusion of certain phonon–phonon interaction processes in a series expansion central to the self-consistent phonon method. In particular, an interaction process involving three phonons is identified to contribute strongly to the anharmonic phonon renormalisation. An attempt was made to extend alamode to include this interaction, which was, regrettably, unsuccessful. The TDEP approach is then applied to diamond in the same manner as silicon. The zone-centre optical phonon is calculated and a comparison to available experimental data is made. The approach is again found to accurately reproduce the experimental data. Consequently, the TDEP approach is used to investigate the so-called quantum isotope effect in diamond. Deviations from the harmonic frequency ratio of the zone-centre phonons are used to investigate the anharmonic nature of the interatomic potential, as well as to search for an experimentally suggested “inversion” of the quantum isotope effect at high pressure. No such inversion of the quantum isotope effect is observed in the calculations made here. A detailed comparison of the effect of different exchange–correlation functionals and pseudopotentials on the density functional theory calculations is made, ultimately recommending local density approximation as the most accurate predictor of phonon frequencies in diamond. Finally, the Raman frequency of natural diamond is calculated at high temperature and pressure using the highly accurate TDEP method. Improvements are made to the stochastic sampling process, eliminating unwanted scatter from misaligned eigenvectors at degenerate points in the Brillouin zone and increasing the precision of the method. The calculated Raman frequency is used to suggest a calibration of the high-frequency edge of the Raman signal from a diamond anvil, which is used as a pressure marker in very-high-pressure experiments. The suggested calibration extends to pressures up to 1 TPa and temperatures up to 2000 K

    Physiological, molecular, and genetic mechanism of action of the biostimulant Quantis™ for increased thermotolerance of potato (Solanum tuberosum L.)

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    Background: Raising global temperatures limit crop productivity and new strategies are needed to improve the resilience of thermosensitive crops such as potato (Solanum tuberosum L.). Biostimulants are emerging as potential crop protection products against environmental stress, however their mechanism of action remains largely unknown, hindering their wider adoption. We used comprehensive physiological, molecular, and mass spectrometry approaches to develop understanding of the mechanism of plant thermotolerance exerted by the biostimulant, Quantis™, under heat stress. Using orthologues gene mutations in Arabidopsis thaliana we report heat-defence genes, modified by Quantis™, which were also investigated for potential overlapping functions in biotic stress defence to Sclerotinia sclerotiorum and Rhizoctonia solani. Results: Quantis™ enhanced PSII photochemical efficiency and decreased thermal dissipation of potato grown under heat stress. These effects were associated with upregulation of genes with antioxidant function, including PR10, flavonoid 3′‐hydroxylase and β-glucosidases, and modulation of abscisic acid (ABA) and cytokinin (CK) activity in leaves by Quantis™. The biostimulant modulated the expression of the heat-defence genes, PEN1, PR4 or MEE59, with functions in leaf photoprotection and root thermal protection, but with no overlapping function in biotic stress defence. Protective root growth under heat stress, following the biostimulant application, was correlated with enhanced CK signalling in roots. Increased endogenous concentrations of ABA and CK in potato leaves and significant upregulation of StFKF1 were consistent with tuberisation promoting effects. Quantis™ application resulted in 4% tuber weight increase and 40% larger tuber size thus mitigating negative effects of heat stress on tuber growth. Conclusions: Quantis™ application prior to heat stress effectively primed heat tolerance responses and alleviated temperature stress of S. tuberosum L. and A. thaliana by modulating the expression and function of PR4 and MEE59 and by regulating CK activity above and below ground, indicating that the mechanism of action of the biostimulant is conserved, and will be effective in many plant species. Thus, a biostimulant application targeting the most susceptible crop developmental stages to heat disorders can be effectively integrated within future agronomy practices to mitigate losses in other thermosensitive crops

    Metabolites in fish and humans as a response to different food ingredients : a metabolomics approach

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    The main objective of this thesis was to evaluate metabolomics changes in humans and fish as a response to food/feed consumption. To alleviate the environmental impact of animal production and maximize the use of resources, the valorization of meat by-products might be an attractive alternative. A meat product containing heart and aorta tissue from pork was designed and analyzed for fatty acid and metabolite composition. In comparison with a control of similar qualities, the designed meat product (or test product) showed higher monounsaturated fatty acid and tyramine levels and lower levels of sugars. The test meat product was used in a randomized controlled clinical trial to test for potential health effects in patients showing atherosclerosis symptoms. Patients receiving the test product showed a decrease in blood levels of low-density lipoproteins, total cholesterol, atherogenic index and triacylglycerols. To reduce the impact of animal production on ecosystems, the replacement of feed ingredients by a microbial alternative was realized. In this study, vegetable oils included in the feed of Arctic char (Salvelinus alpinus) were replaced by biomass of the oleaginous yeast (Rhodotorula toruloides). The analysis of the yeast biomass showed safe levels of pollutants and heavy metals. Fish growth and muscle fatty acid profile were similar to the control. A higher liver weight and hepatosomatic index were observed in fish fed including the yeast biomass, albeit no significant difference in liver fat content or in hepatic enzyme activity was observed. Quantification of plasma metabolites revealed higher levels of metabolites involved in energy pathways such as one-carbon metabolism and gluconeogenesis.In conclusion, this thesis showed that metabolomics can be applied to evaluate effects of food/feed at the molecular level in complex systems. It adds knowledge on the effects of meat by-product consumption in the particular case of atherosclerosis symptoms. The fish feed trial showed the possibility of feed modification with a specific yeast

    High sensitivity of mobile phone microscopy screening for Schistosoma haematobium in Azaguié, Côte d'Ivoire

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    Schistosomiasis infections continue to impact African settings disproportionately, and there is an urgent need for novel tools to evaluate infection control and elimination strategies at the community level. Mobile phone microscopes are portable and semiautomated devices with multiple applications for screening neglected tropical diseases. In a community-based schistosomiasis screening program in Azaguie, Cote d'Ivoire, mobile phone microscopy demonstrated a sensitivity of 85.7% (95% CI: 69.7-95.2%) and specificity of 93.3% (95% CI: 87.7-96.9%) for Schistosoma haematobium identification compared with conventional light microscopy, and 95% sensitivity (95% CI: 74.1-99.8%) with egg concentrations of five or more per 10 mL of urine. Mobile phone microscopy is a promising tool for schistosomiasis control and elimination efforts

    Fremont Legacy in Capitol Reef and the Waterpocket Fold: A Radiocarbon Analysis of the Pectol Collection Coiled Basketry Using Bayesian Modeling

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    Perishable artifacts provide ample opportunity to better understand past human lives. Artifacts constructed from shorter-lived plant materials can make a significant contribution to archaeological research through radiocarbon dating. Analyzing and radiocarbon dating the basketry construction types from the Pectol Collection aids in the development of a more precise prehistoric timeline for the Capitol Reef and Waterpocket Fold (CRWF) area of southeastern Utah. Basketry technology construction is treated as a signal for growing Fremont occupancy throughout the Colorado Plateau and eastern Great Basin, and can the provide prior information used to better organize Bayesianbased age models. From AD 750–1050, a narrow window of regionally stable environmental conditions could have promoted agricultural intensification, with peak occupancy occurring in northern Fremont regions during AD 840–1080. New data will test the hypothesis that peak CRWF occupation in the south occurred simultaneously with Cub Creek in the north. However, compared to their northern neighbors, Fremont occupancy in the CRWF peaked later in time, closer to AD 1100. Future research can use new data to examine whether agricultural communities in the northern Colorado Plateau formed earlier but persisted for a shorter period of time than those in the eastern Great Basin

    Enhancing the forensic comparison process of common trace materials through the development of practical and systematic methods

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    An ongoing advancement in forensic trace evidence has driven the development of new and objective methods for comparing various materials. While many standard guides have been published for use in trace laboratories, different areas require a more comprehensive understanding of error rates and an urgent need for harmonizing methods of examination and interpretation. Two critical areas are the forensic examination of physical fits and the comparison of spectral data, which depend highly on the examiner’s judgment. The long-term goal of this study is to advance and modernize the comparative process of physical fit examinations and spectral interpretation. This goal is fulfilled through several avenues: 1) improvement of quantitative-based methods for various trace materials, 2) scrutiny of the methods through interlaboratory exercises, and 3) addressing fundamental aspects of the discipline using large experimental datasets, computational algorithms, and statistical analysis. A substantial new body of knowledge has been established by analyzing population sets of nearly 4,000 items representative of casework evidence. First, this research identifies material-specific relevant features for duct tapes and automotive polymers. Then, this study develops reporting templates to facilitate thorough and systematic documentation of an analyst’s decision-making process and minimize risks of bias. It also establishes criteria for utilizing a quantitative edge similarity score (ESS) for tapes and automotive polymers that yield relatively high accuracy (85% to 100%) and, notably, no false positives. Finally, the practicality and performance of the ESS method for duct tape physical fits are evaluated by forensic practitioners through two interlaboratory exercises. Across these studies, accuracy using the ESS method ranges between 95-99%, and again no false positives are reported. The practitioners’ feedback demonstrates the method’s potential to assist in training and improve peer verifications. This research also develops and trains computational algorithms to support analysts making decisions on sample comparisons. The automated algorithms in this research show the potential to provide objective and probabilistic support for determining a physical fit and demonstrate comparative accuracy to the analyst. Furthermore, additional models are developed to extract feature edge information from the systematic comparison templates of tapes and textiles to provide insight into the relative importance of each comparison feature. A decision tree model is developed to assist physical fit examinations of duct tapes and textiles and demonstrates comparative performance to the trained analysts. The computational tools also evaluate the suitability of partial sample comparisons that simulate situations where portions of the item are lost or damaged. Finally, an objective approach to interpreting complex spectral data is presented. A comparison metric consisting of spectral angle contrast ratios (SCAR) is used as a model to assess more than 94 different-source and 20 same-source electrical tape backings. The SCAR metric results in a discrimination power of 96% and demonstrates the capacity to capture information on the variability between different-source samples and the variability within same-source samples. Application of the random-forest model allows for the automatic detection of primary differences between samples. The developed threshold could assist analysts with making decisions on the spectral comparison of chemically similar samples. This research provides the forensic science community with novel approaches to comparing materials commonly seen in forensic laboratories. The outcomes of this study are anticipated to offer forensic practitioners new and accessible tools for incorporation into current workflows to facilitate systematic and objective analysis and interpretation of forensic materials and support analysts’ opinions
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