5,004 research outputs found

    Egypt’s dispersed heritage: Multi-directional storytelling through comic art

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    This paper responds to a need to address the colonial history of collections of Egyptian archaeology and to find new ways in which Egyptian audiences can assume greater agency in such a process. The ‘Egypt’s Dispersed Heritage’ project presents a model of engagement whereby foreign museum collections become the inspiration for Egyptians to express their own feelings about the removal of their heritage abroad using idioms and traditional storytelling of cultural relevance to them. A series of online comics confronting contentious heritage issues, including the display of mummified human remains, eugenics, looting and destruction, is discussed. It is argued that this approach is not only more relatable for Egyptian communities, but moreover provides space for the development of grass-roots critique of heritage practices, both in the UK and in Egypt. Museums have a responsibility to take on board these critiques, curating not just objects but relationships forged amongst them in historical and contemporary society

    Determination of protein binding affinities within hydrogel-based molecularly imprinted polymers (HydroMIPs)

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    Hydrogel-based molecularly imprinted polymers (HydroMIPs) were prepared for several proteins (haemoglobin, myoglobin and catalase) using a family of acrylamide-based monomers. Protein aïŹƒnity towards the HydroMIPs was investigated under equilibrium conditions and over a range of concentrations using specific binding with Hill slope saturation profiles. We report HydroMIP binding aïŹƒnities, in terms of equilibrium dissociation constants (Kd) within the micro-molar range (25 ± 4 mM, 44 ± 3 mM, 17 ± 2 mM for haemoglobin, myoglobin and catalase respectively within a polyacrylamide-based MIP). The extent of non-specific binding or cross-selectivity for non-target proteins has also been assessed. It is concluded that both selectivity and aïŹƒnity for both cognate and non-cognate proteins towards the MIPs were dependent on the concentration and the complementarity of their structures and size. This is tentatively attributed to the formation of protein complexes during both the polymerisation and rebinding stages at high protein concentrations. We have used atomic force spectroscopy to characterize molecular interactions in the MIP cavities using protein-modified AFM tips. Attractive and repulsive force curves were obtained for the MIP and NIP (non-imprinted polymer) surfaces (under protein loaded or unloaded states). Our force data suggest that we have produced selective cavities for the template protein in the MIPs and we have been able to quantify the extent of non-specific protein binding on, for example, a non-imprinted polymer (NIP) control surface

    Selective extraction of proteins and other macromolecules from biological samples using molecular imprinted polymers

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    The accurate determination of intact macromolecules in biological samples, such as blood, plasma, serum, urine, tissue and feces is a challenging problem. The increased interest in macromolecules both as candidate drugs and as biomarkers for diagnostic purposes means that new method development approaches are needed. This review charts developments in the use of molecularly imprinted polymers first for small-molecular-mass compounds then for proteins and other macromolecules. Examples of the development of molecularly imprinted polymers for macromolecules are highlighted. The two main application areas to date are sensors and separation science, particularly SPE. Examples include peptides and polypeptides, lysozyme, hemoglobin, ovalbumin, bovine serum albumin and viruses

    Direct Extraction of QCD Lambda MS-bar from e+e- Jet Observables

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    We directly fit the QCD dimensional transmutation parameter, Lambda MS-bar, to experimental data on e+e- jet observables, making use of next-to-leading order (NLO) perturbative calculations. In this procedure there is no need to mention, let alone to arbitrarily vary, the unphysical renormalisation scale mu, and one avoids the spurious and meaningless ``theoretical error'' associated with standard alpha_s determinations. PETRA, SLD, and LEP data are considered in the analysis. An attempt is made to estimate the importance of uncalculated next-NLO and higher order perturbative corrections, and power corrections, by studying the scatter in the values of Lambda MS-bar obtained for different observables.Comment: 46 pages, 22 figure

    Examining the potential for climate change mitigation from zero tillage

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    The benefits of reduced and zero-tillage systems have been presented as reducing runoff, enhancing water retention and preventing soil erosion. There is also general agreement that the practice can conserve and enhance soil organic carbon (C) levels to some extent. However, their applicability in mitigating climate change has been debated extensively, especially when the whole profile of C in the soil is considered, along with a reported risk of enhanced nitrous oxide (N2O) emissions. The current paper presents a meta-analysis of existing literature to ascertain the climate change mitigation opportunities offered by minimizing tillage operations. Research suggests zero tillage is effective in sequestering C in both soil surface and sub-soil layers in tropical and temperate conditions. The C sequestration rate in tropical soils can be about five times higher than in temperate soils. In tropical soils, C accumulation is generally correlated with the duration of tillage. Reduced N2O emissions under long-term zero tillage have been reported in the literature but significant variability exists in the N2O flux information. Long-term, location-specific studies are needed urgently to determine the precise role of zero tillage in driving N2O fluxes. Considering the wide variety of crops utilized in zero-tillage studies, for example maize, barley, soybean and winter wheat, only soybean has been reported to show an increase in yield with zero tillage (7·7% over 10 years). In several cases yield reductions have been recorded e.g. c. 1–8% over 10 years under winter wheat and barley, respectively, suggesting zero tillage does not bring appreciable changes in yield but that the difference between the two approaches may be small. A key question that remains to be answered is: are any potential reductions in yield acceptable in the quest to mitigate climate change, given the importance of global food security

    Many-body physics of a quantum fluid of exciton-polaritons in a semiconductor microcavity

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    Some recent results concerning nonlinear optics in semiconductor microcavities are reviewed from the point of view of the many-body physics of an interacting photon gas. Analogies with systems of cold atoms at thermal equilibrium are drawn, and the peculiar behaviours due to the non-equilibrium regime pointed out. The richness of the predicted behaviours shows the potentialities of optical systems for the study of the physics of quantum fluids.Comment: Proceedings of QFS2006 conference to appear on JLT

    The solid state forms of the sex hormone 17-ÎČ-estradiol

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    The crystal structure of the single component form of the primary female sex hormone, 17-ÎČ-estradiol (BES), is reported, solved from single crystals obtained by sublimation. The Zâ€Č = 2 P2₁2₁2₁ structure was computationally predicted as one of the thermodynamically plausible structures. It appears that the dehydration process for the very stable hemihydrate structure is a complex process, strongly affected by particle size and conditions. An experimental polymorph screen has produced six solid forms of BES, including novel acetonitrile and highly labile ethylene dichloride solvates, and reproduced previously reported methanol and propanol solvates. These have been characterized, as far as possible given the metastability relative to the hemihydrate (BES·0.5H₂O), by single-crystal X-ray diffraction (SCXRD), powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), hot-stage microscopy and Fourier transform infrared spectroscopy (FT-IR), sorting out some of the confusion in the earlier literature

    Optimal Renormalization Scale and Scheme for Exclusive Processes

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    We use the BLM method to fix the renormalization scale of the QCD coupling in exclusive hadronic amplitudes such as the pion form factor and the photon-to-pion transition form factor at large momentum transfer. Renormalization-scheme-independent commensurate scale relations are established which connect the hard scattering subprocess amplitudes that control exclusive processes to other QCD observables such as the heavy quark potential and the electron-positron annihilation cross section. The commensurate scale relation connecting the heavy quark potential, as determined from lattice gauge theory, to the photon-to-pion transition form factor is in excellent agreement with Îłe→π0e\gamma e \to \pi^0 e data assuming that the pion distribution amplitude is close to its asymptotic form 3fπx(1−x)\sqrt{3}f_\pi x(1-x). We also reproduce the scaling and normalization of the ÎłÎłâ†’Ï€+π−\gamma \gamma \to \pi^+ \pi^- data at large momentum transfer. Because the renormalization scale is small, we argue that the effective coupling is nearly constant, thus accounting for the nominal scaling behavior of the data. However, the normalization of the space-like pion form factor Fπ(Q2)F_\pi(Q^2) obtained from electroproduction experiments is somewhat higher than that predicted by the corresponding commensurate scale relation. This discrepancy may be due to systematic errors introduced by the extrapolation of the γ∗p→π+n\gamma^* p \to \pi^+ n electroproduction data to the pion pole.Comment: 22 pages, Latex, 7 Latex figures. Several references added, discussion of scale fixing revised for clarity. Final version to appear in Phys. Rev.

    MIP-based protein profiling: A method for interspecies discrimination

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    Due to recent public concern and interest in the authenticity and origin of meat, for example, the 2013 “horsemeat scandal” in the human food chain, novel sensor strategies for the discrimination between protein species are highly sought after. In this work, molecularly imprinted polymers (MIPs) are utilised for protein discrimination using electrochemical sensor and spectrophotometric techniques. MIP selectivity between two proteins of similar molecular weight (haemoglobin and serum albumin) were compared across three different species, namely pork, beef and human. Bulk MIPs resulted in Kd and Bmax values of 184±23 ”M, and 582 ”mol g-1 for BHb, 246.3±26 ”M, and 673 ”mol g-1 for HHb; 276±31 ”M, and 467 ”mol g-1 for PHb. With the aid of chemometrics, i.e. multivariate analysis and pattern recognition, distinctive protein profiles have been achieved for species discrimination in both spectrophotometric and electrochemical analysis experiments. MIP suitability and selectivity within complex matrices was also assessed using urine, human plasma and human serum. Pattern recognition MIP-based protein profiling demonstrated positive outputs yielding either a ‘bovine’ or ‘not-bovine’ outcome (p = 0.0005) for biological samples spiked with/without bovine using respective bovine haemoglobin MIPs
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