560 research outputs found

    Selling just preservation

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    Treves et al. argue for better representation of voiceless groups in current policy decisions. We agree with the argument but believe it will be challenging to convince enough people of its importance to change policy โ€” especially those political groups who are not predisposed to agreeing with these kinds of arguments. We draw on the social psychology literature to recommend three principles for increasing the persuasiveness of the argument to the public: pre-suasion, framing, and tailoring for the audience. We apply these principles to make concrete recommendations for framing the argument to persuade the American political right

    Metastable Nanostructured Metallized Fluoropolymer Composites for Energetics

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    Fluoropolymers have long served as potent oxidizers for metal-based pyrolant designs for the preparation of energetic materials. Commercial perfluoropolyethers (PFPEs), specifically known as Fomblinsยฎ, are well-known to undergo accelerated thermal degradation in the presence of native metals and Lewis acids producing energetically favorable metal fluoride species. This study employs the use of PFPEs to coat nano-aluminum (n-Al) and under optimized stoichiometric formulations, harness optimized energy output. The PFPEs serve as ideal oxidizers of n-Al because they are non-volatile, viscous liquids that coat the particles thereby maximizing surface interactions. The n-Al/PFPE blended combination is required to interface with an epoxy-based matrix in order to engineer a moldable/machinable, structurally viable epoxy composite without compromising bulk thermal/mechanical properties. Computational modeling/simulation supported by thermal experimental studies showed that the n-Al/PFPE blended epoxy composites produced an energetic material that undergoes latent thermal metal-mediated oxidation. Details of the work include the operationally simple, scalable synthetic preparation, thermal properties from DSC/TGA, and SEM/TEM of these energetic metallized nanocomposite systems. Post-burn analysis using powder XRD of this pyrolant system confirms the presence of the predominating exothermic metal-mediated oxidized AlF3 species in addition to the production of Al2O3 and Al4C3 during the deflagration reaction. Details of this first epoxy-based energetic nanocomposite entrained with a thermally reactive formulation of PFPE coated n-Al particles are presented herein

    The SCUBA-2 Cosmology Legacy Survey: Ultraluminous star-forming galaxies in a z=1.6 cluster

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    We analyze new SCUBA-2 submillimeter and archival SPIRE far-infrared imaging of a z = 1.62 cluster, Cl 0218.3โ€“0510, which lies in the UKIRT Infrared Deep Sky Survey/Ultra-Deep Survey field of the SCUBA-2 Cosmology Legacy Survey. Combining these tracers of obscured star-formation activity with the extensive photometric and spectroscopic information available for this field, we identify 31 far-infrared/submillimeter-detected probable cluster members with bolometric luminosities 1012 L โ˜‰ and show that by virtue of their dust content and activity, these represent some of the reddest and brightest galaxies in this structure. We exploit ALMA submillimeter continuum observations, which cover one of these sources, to confirm the identification of a SCUBA-2-detected ultraluminous star-forming galaxy in this structure. Integrating the total star-formation activity in the central region of the structure, we estimate that it is an order of magnitude higher (in a mass-normalized sense) than clusters at z ~ 0.5-1. However, we also find that the most active cluster members do not reside in the densest regions of the structure, which instead host a population of passive and massive, red galaxies. We suggest that while the passive and active populations have comparable near-infrared luminosities at z = 1.6, MH ~ โ€“23, the subsequent stronger fading of the more active galaxies means that they will evolve into passive systems at the present day that are less luminous than the descendants of those galaxies that were already passive at z ~ 1.6 (MH ~ โ€“20.5 and MH ~ โ€“21.5, respectively, at z ~ 0). We conclude that the massive galaxy population in the dense cores of present-day clusters were already in place at z = 1.6 and that in Cl 0218.3โ€“0510 we are seeing continuing infall of less extreme, but still ultraluminous, star-forming galaxies onto a pre-existing structure

    Collagen-Binding Peptidoglycans Inhibit MMP Mediated Collagen Degradation and Reduce Dermal Scarring

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    Scarring of the skin is a large unmet clinical problem that is of high patient concern and impact. Wound healing is complex and involves numerous pathways that are highly orchestrated, leaving the skin sealed, but with abnormal organization and composition of tissue components, namely collagen and proteoglycans, that are then remodeled over time. To improve healing and reduce or eliminate scarring, more rapid restoration of healthy tissue composition and organization offers a unique approach for development of new therapeutics. A synthetic collagen-binding peptidoglycan has been developed that inhibits matrix metalloproteinase-1 and 13 (MMP-1 and MMP-13) mediated collagen degradation. We investigated the synthetic peptidoglycan in a rat incisional model in which a single dose was delivered in a hyaluronic acid (HA) vehicle at the time of surgery prior to wound closure. The peptidoglycan treatment resulted in a significant reduction in scar tissue at 21 days as measured by histology and visual analysis. Improved collagen architecture of the treated wounds was demonstrated by increased tensile strength and transmission electron microscopy (TEM) analysis of collagen fibril diameters compared to untreated and HA controls. The peptidoglycan's mechanism of action includes masking existing collagen and inhibiting MMP-mediated collagen degradation while modulating collagen organization. The peptidoglycan can be synthesized at low cost with unique design control, and together with demonstrated preclinical efficacy in reducing scarring, warrants further investigation for dermal wound healing

    Quantification of collagen and proteoglycan deposition in a murine model of airway remodelling

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    BACKGROUND: Sub-epithelial extracellular matrix deposition is a feature of asthmatic airway remodelling associated with severity of disease, decline in lung function and airway hyperresponsiveness. The composition of, and mechanisms leading to, this increase in subepithelial matrix, and its importance in the pathogenesis of asthma are unclear. This is partly due to limitations of the current models and techniques to assess airway remodelling. METHODS: In this study we used a modified murine model of ovalbumin sensitisation and challenge to reproduce features of airway remodelling, including a sustained increase in sub-epithelial matrix deposition. In addition, we have established techniques to accurately and specifically measure changes in sub-epithelial matrix deposition, using histochemical and immunohistochemical staining in conjunction with digital image analysis, and applied these to the measurement of collagen and proteoglycans. RESULTS: 24 hours after final ovalbumin challenge, changes similar to those associated with acute asthma were observed, including inflammatory cell infiltration, epithelial cell shedding and goblet cell hyperplasia. Effects were restricted to the bronchial and peribronchial regions with parenchymal lung of ovalbumin sensitised and challenged mice appearing histologically normal. By 12 days, the acute inflammatory changes had largely resolved and increased sub-epithelial staining for collagen and proteoglycans was observed. Quantitative digital image analysis confirmed the increased deposition of sub-epithelial collagen (33%, p < 0.01) and proteoglycans (32%, p < 0.05), including decorin (66%, p < 0.01). In addition, the increase in sub-epithelial collagen deposition was maintained for at least 28 days (48%, p < 0.001). CONCLUSION: This animal model reproduces many of the features of airway remodelling found in asthma and allows accurate and reproducible measurement of sub-epithelial extra-cellular matrix deposition. As far as we are aware, this is the first demonstration of increased sub-epithelial proteoglycan deposition in an animal model of airway remodelling. This model will be useful for measurement of other matrix components, as well as for assessment of the molecular mechanisms contributing to, and agents to modulate airway remodelling

    Evaluation of potential habitat with an integrated analysis of a spatial conservation strategy for Davidโ€™s deer, Elaphurus davidians

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    How to assess the potential habitat integrating landscape dynamics and population research, and how to reintroduce animals to potential habitats in environments highly human disturbed are still questions to be answered in conservation biology. According to behavioral research on Elaphurus davidians, we have developed a suitability index and a risk index to evaluate the potential habitats for the deer. With these indices, we conducted two transect assessments to evaluate the gradient change of the target region. Then, taking rivers as border lines, we tabulated the forest areas, high grassland area and total area and then compared the forest and high grassland area in each subregion. Furthermore, we computed the land use transfer matrix for the whole Yancheng coast during 1987โ€“2000. We also computed human modified index (HMI) in six subregions. Lastly with a geographical information system support we obtained the spatial distribution of the indices and evaluation of the whole potential habitats from a neighborhood analysis. The transect assessment showed that the suitability of the coastal area was higher than that of the inland area for the deer, while the southern area was higher than the northern. Landscape metrics and HMI analysis showed that different landscape patterns and different anthropogenic disturbance existed within the region, and the increasing human disturbance was the key factor causing the pattern dynamics. The evaluation of potential habitats showed that there was an estimated carrying capacity of no more than 10,000 for Davidโ€™s deer reintroduction into the natural area. Also the reintroduction strategy was discussed. This integrated approach linked the population research and the landscape metrics, and the dataset with different scale; thus, it is an approach likely to be useful for the protection of other large animal in a landscape highly disturbed by humans

    Ecologically Appropriate Xenobiotics Induce Cytochrome P450s in Apis mellifera

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    BACKGROUND: Honey bees are exposed to phytochemicals through the nectar, pollen and propolis consumed to sustain the colony. They may also encounter mycotoxins produced by Aspergillus fungi infesting pollen in beebread. Moreover, bees are exposed to agricultural pesticides, particularly in-hive acaricides used against the parasite Varroa destructor. They cope with these and other xenobiotics primarily through enzymatic detoxificative processes, but the regulation of detoxificative enzymes in honey bees remains largely unexplored. METHODOLOGY/PRINCIPAL FINDINGS: We used several approaches to ascertain effects of dietary toxins on bee susceptibility to synthetic and natural xenobiotics, including the acaricide tau-fluvalinate, the agricultural pesticide imidacloprid, and the naturally occurring mycotoxin aflatoxin. We administered potential inducers of cytochrome P450 enzymes, the principal biochemical system for Phase 1 detoxification in insects, to investigate how detoxification is regulated. The drug phenobarbital induces P450s in many insects, yet feeding bees with phenobarbital had no effect on the toxicity of tau-fluvalinate, a pesticide known to be detoxified by bee P450s. Similarly, no P450 induction, as measured by tau-fluvalinate tolerance, occurred in bees fed xanthotoxin, salicylic acid, or indole-3-carbinol, all of which induce P450s in other insects. Only quercetin, a common pollen and honey constituent, reduced tau-fluvalinate toxicity. In microarray comparisons no change in detoxificative gene expression was detected in phenobarbital-treated bees. However, northern blot analyses of guts of bees fed extracts of honey, pollen and propolis showed elevated expression of three CYP6AS P450 genes. Diet did not influence tau-fluvalinate or imidacloprid toxicity in bioassays; however, aflatoxin toxicity was higher in bees consuming sucrose or high-fructose corn syrup than in bees consuming honey. CONCLUSIONS/SIGNIFICANCE: These results suggest that regulation of honey bee P450s is tuned to chemicals occurring naturally in the hive environment and that, in terms of toxicological capacity, a diet of sugar is not equivalent to a diet of honey

    Running GAGs: myxoid matrix in tumor pathology revisited: Whatโ€™s in it for the pathologist?

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    Ever since Virchow introduced the entity myxoma, abundant myxoid extracellular matrix (ECM) has been recognized in various reactive and neoplastic lesions. Nowadays, the term โ€œmyxoidโ€ is commonly used in daily pathological practice. But what do todayโ€™s pathologists mean by it, and what does the myxoid ECM tell the pathologist? What is known about the exact composition and function of the myxoid ECM 150ย years after Virchow? Here, we give an overview of the composition and constituents of the myxoid ECM as known so far and demonstrate the heterogeneity of the myxoid ECM among different tumors. We discuss the possible role of the predominant constituents of the myxoid ECM and attempt to relate them to differences in clinical behavior. Finally, we will speculate on the potential relevance of this knowledge in daily pathological practice
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