4,173 research outputs found

    Commercial property markets and property cycles in Chinese cities

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    This paper uses interview data to explore and examines property markets in three Chinese cities with the focus placed on the emergence of the commercial property markets and the government-market interplay, noting the market formation process and cycles that are ‘unexpected’ in a transitional economy. The research identified varying opinions and perceptions among key stake-holders about cycles in China’s emerging commercial property markets. Interviews in the three cities suggested a spectrum of factors that may substantially affect the stability of China’s office markets. A cross-sectional comparison of the three cities has revealed a similar pattern of cyclical behaviour highlighting structural change and state intervention with leads-and-lags, in spite of the dispersion in geography, culture and market maturity. The various views offered about market mechanism and cyclical behaviour represent varying levels of market maturity. These brief insights offer an opportunity to develop an alternative approach to measure property market conditions in emerging or immature markets such as China.published_or_final_versio

    Habitat-use influences severe disease-mediated population declines in two of the most common garden bird species in Great Britain

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    The influence of supplementary feeding of wildlife on disease transmission and its consequent impacts on population dynamics are underappreciated. In Great Britain, supplementary feeding is hypothesised to have enabled the spread of the protozoan parasite, Trichomonas gallinae, from columbids to finches, leading to epidemic finch trichomonosis and a rapid population decline of greenfinch (Chloris chloris). More recently, chaffinch (Fringilla coelebs), has also declined markedly from the second to fifth commonest bird in Britain. Using citizen science data, we show that both declines were driven primarily by reduced adult survival, with the greatest reductions occurring in peri-domestic habitats, where supplementary food provision is common. Post-mortem examinations showed a proportional increase in chaffinch trichomonosis cases, near-contemporaneous with its population decline. Like greenfinches, chaffinches often use supplementary food, but are less associated with human habitation. Our results support the hypothesis that supplementary feeding can increase parasite transmission frequency within and between common species. However, the dynamics behind resultant population change can vary markedly, highlighting the need for integrating disease surveillance with demographic monitoring. Other species susceptible to T. gallinae infection may also be at risk. Supplementary feeding guidelines for wildlife should include disease mitigation strategies to ensure that benefits to target species outweigh risks

    Role of clathrin in dense core vesicle biogenesis

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    The dense-core vesicles (DCVs) of neuroendocrine cells are a rich source of bioactive molecules such as peptides, hormones, and neurotransmitters, but relatively little is known about how they are formed. Using fractionation profiling, a method that combines subcellular fractionation with mass spectrometry, we identified ∼1200 proteins in PC12 cell vesicle-enriched fractions, with DCV-associated proteins showing distinct profiles from proteins associated with other types of vesicles. To investigate the role of clathrin in DCV biogenesis, we stably transduced PC12 cells with an inducible shRNA targeting clathrin heavy chain, resulting in ∼85% protein loss. DCVs could still be observed in the cells by electron microscopy, but mature profiles were ∼4-fold less abundant than in mock-treated cells. By quantitative mass spectrometry, DCV-associated proteins were found to be reduced ∼2-fold in clathrin-depleted cells as a whole and ∼5-fold in vesicle-enriched fractions. Our combined datasets enabled us to identify new candidate DCV components. Secretion assays revealed that clathrin depletion causes a near-complete block in secretagogue-induced exocytosis. Taken together, our data indicate that clathrin has a function in DCV biogenesis beyond its established role in removing unwanted proteins from the immature vesicle.This work was funded by grants from the Wellcome Trust: 086598 (to M.S.R.), 100140 (Wellcome Trust Strategic Award), and 093026 (for the FEI Tecnai G2 Spirit BioTWIN transmission EM); and by a National Institutes of Health/National Institute of Diabetes and Digestive and Kidney Diseases grant (R01DK102496) to A.B

    Penetration and intracellular uptake of poly(glycerol-adipate)nanoparticles into 3-dimensional brain tumour cell culture models

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    Nanoparticle (NP) drug delivery systems may potentially enhance the efficacy of therapeutic agents. It is difficult to characterise many important properties of NPs in vivo and therefore attempts have been made to use realistic in vitro multicellular spheroids instead. In this paper we have evaluated poly(glycerol-adipate) (PGA) NPs as a potential drug carrier for local brain cancer therapy. Various 3-dimensional (3-D) cell culture models have been used to investigate the delivery properties of PGA NPs. Tumour cells in 3-D culture showed a much higher level of endocytic uptake of NPs than a mixed normal neonatal brain cell population. Differences in endocytic uptake of NPs in 2-D and 3-D models strongly suggest that it is very important to use in vitro 3-D cell culture models for evaluating this parameter. Tumour penetration of NPs is another important parameter which could be studied in 3-D cell models. The penetration of PGA NPs through 3-D cell culture varied between models, which will therefore require further study to develop useful and realistic in vitro models. Further use of 3-D cell culture models will be of benefit in the future development of new drug delivery systems, particularly for brain cancers which are more difficult to study in vivo

    Automatic eduction and statistical analysis of coherent structures in the wall region of a confine plane

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    This paper describes a vortex detection algorithm used to expose and statistically characterize the coherent flow patterns observable in the velocity vector fields measured by Particle Image Velocimetry (PIV) in the impingement region of air curtains. The philosophy and the architecture of this algorithm are presented. Its strengths and weaknesses are discussed. The results of a parametrical analysis performed to assess the variability of the response of our algorithm to the 3 user-specified parameters in our eduction scheme are reviewed. The technique is illustrated in the case of a plane turbulent impinging twin-jet with an opening ratio of 10. The corresponding jet Reynolds number, based on the initial mean flow velocity U0 and the jet width e, is 14000. The results of a statistical analysis of the size, shape, spatial distribution and energetic content of the coherent eddy structures detected in the impingement region of this test flow are provided. Although many questions remain open, new insights into the way these structures might form, organize and evolve are given. Relevant results provide an original picture of the plane turbulent impinging jet

    Is extinction forever?

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    We thank the various people who provided feedback and encouragement when we presented preliminary findings at the June 2012 annual conference of the Association for Tropical Biology and Conservation in Bonito, Brazil. We also thank Richard J. Ladle and an anonymous reviewer for direct comments to the manuscript.Mistrust of science has seeped into public perception of the most fundamental aspect of conservation—extinction. The term ought to be straightforward, and yet, there is a disconnect between scientific discussion and public views. This is not a mere semantic issue, rather one of communication. Within a population dynamics context, we say that a species went locally extinct, later to document its return. Conveying our findings matters, for when we use local extinction, an essentially nonsensical phrase, rather than extirpation, which is what is meant, then we contribute to, if not create outright, a problem for public understanding of conservation, particularly as local extinction is often shortened to extinction in media sources. The public that receives the message of our research void of context and modifiers comes away with the idea that extinction is not forever or, worse for conservation as a whole, that an extinction crisis has been invented.Yeshttp://pus.sagepub.com/content/21/3/258.shor

    For which side the bell tolls: The laterality of approach-avoidance associative networks

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    The two hemispheres of the brain appear to play different roles in emotion and/or motivation. A great deal of previous research has examined the valence hypothesis (left hemisphere = positive; right = negative), but an increasing body of work has supported the motivational hypothesis (left hemisphere = approach; right = avoidance) as an alternative. The present investigation (N = 117) sought to provide novel support for the latter perspective. Left versus right hemispheres were briefly activated by neutral lateralized auditory primes. Subsequently, participants categorized approach versus avoidance words as quickly and accurately as possible. Performance in the task revealed that approach-related thoughts were more accessible following left-hemispheric activation, whereas avoidance-related thoughts were more accessible following right-hemispheric activation. The present results are the first to examine such lateralized differences in accessible motivational thoughts, which may underlie more “downstream” manifestations of approach and avoidance motivation such as judgments, decision making, and behavior

    Author Correction: Three-dimensional strain imaging of irradiated chromium using multi-reflection Bragg coherent diffraction

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    The original version of this Article did not correctly credit and cite relevant previous work. The fifth to seventh sentences of the fifth paragraph of the ‘Three-dimensional imaging of the defects’ section previously read: “In our case, BCDI is sensitive to defects such as voids and dislocations through its strain field sensitivity rather than the spatial resolution46. This is illustrated by the relationship between the continuum representation of the crystal, (Formula presented.) , and the diffraction intensity, I(q) in the far field under a perfectly coherent illumination and in the kinematical scattering approximation given by (Formula presented.). Here, r and q are the real and reciprocal space coordinates respectively, (Formula presented.) is the Fourier transform, Q is the measured Bragg peak, and u(r) is the vector displacement field that is a continuum description of how the atoms are displaced from their equilibrium positions47.” The correct version reads: “In our case, BCDI is sensitive to defects such as voids and dislocations through its strain field sensitivity rather than the spatial resolution46. This is demonstrated by the relationship (Formula presented.). whereby (Formula presented.) is the intensity, (Formula presented.) is the mathematical description of the crystal as a continuum, (Formula presented.) denotes the Fourier transformation operator, Q is the Bragg reflection that was measured, and u(r) is the displacement field47.” The final six sentences of the Results section previously read: “Furthermore, underestimating the defect density prevents TEM from accurately determining the corresponding change in properties. For instance, Weiß et al. show a factor of 2 between measured and calculated change in hardness for neutron irradiated EUROFER9771. Meanwhile, Reza et al. report the same discrepancy between Transient Grating Spectroscopy (TGS)-measured and TEM-determined thermal diffusivity for self-ion irradiated tungsten72. It is important to note that when Reza et al. included small defects from molecular dynamics (MD) simulations, the combination of the TEM and MD data matches TGS measurements. This result confirms the theory that point defects play a significant role in the thermal diffusivity of a material and further reinforces the need to accurately characterize small defects in order to evaluate irradiation-induced changes in properties.” This has been replaced with: ““Hirst et al. opined that the underestimated defects density in TEM measurements comes with a corresponding mischaracterization of the materials properties70. This is demonstrated in a study by Weiß et al. who showed that the hardness values obtained from TEM data of neutron irradiated reduced activation ferritic/martensitic steel is significantly smaller than values from tensile testing. This clearly support the notion that underestimation of point defects from TEM analysis which goes into the dispersed barrier hardening model affects the calculated hardness value71. Hence, the difference in the magnitude of swelling between TEM and BCDI estimates is well justified. In a bid to accurately quantify nanoscale defects in irradiated materials, Meslin et al., used multiple characterization techniques which include TEM, Small Angle Neutron Scattering, Positron Annihilation Spectroscopy and Atom Probe Tomography which are sensitive to different types of nanoscale defects. The study clearly demonstrates the strength and complementarities of each technique72. This further support the need to develop multiple characterization techniques that can complements TEM for defects quantification and building predictive tools.” Consequently, Reference 72, which previously read “Reza, A., Yu, H., Mizohata, K. & Hofmann, F. Thermal diffusivity degradation and point defect density in self-ion implanted tungsten. Acta Mater. 193, 270–279 (2020)”, has been replaced by “Meslin, E. et al. Characterization of neutron-irradiated ferritic model alloys and a RPV steel from combined APT, SANS, TEM, and PAS analyses J. Nucl. Mater. 406, 73–83 (2010).” This has been corrected in both the PDF and HTML versions of the Article

    Three-dimensional strain imaging of irradiated chromium using multi-reflection Bragg coherent diffraction

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    Radiation-induced materials degradation is a key concern in limiting the performance of nuclear materials. The formation of nanoscale void and gas bubble superlattices in metals and alloys under radiation environments can effectively mitigate radiation-induced damage, such as swelling and aid the development of next generation radiation tolerant materials. To effectively manage radiation-induced damage via superlattice formation, it is critical to understand the microstructural changes and strain induced by such superlattices. We utilize multi-reflection Bragg coherent diffraction imaging to quantify the full strain tensor induced by void superlattices in iron irradiated chromium substrate. Our approach provides a quantitative estimation of radiation-induced three-dimensional (3D) strain generated at the microscopic level and predicts the number density of defects with a high degree of sensitivity. Such quantitative evaluation of 3D strain in nuclear materials can have a major impact on predicting materials behavior in radiation environments and can revolutionize design of radiation tolerant materials
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