An accurate speciation mapping of non-methane volatile organic compounds (NMVOC) emissions has an important impact on the performance of chemical transport models (CTMs) in simulating ozone mixing ratios and secondary organic aerosols. Taking the INTEX-B Asian NMVOC emission inventory as the case, we developed an improved speciation framework to generate model-ready anthropogenic NMVOC emissions for various gas-phase chemical mechanisms commonly used in CTMs in this work, by using an explicit assignment approach and updated NMVOC profiles. NMVOC profiles were selected and aggregated from a wide range of new measurements and the SPECIATE database v.4.2. To reduce potential uncertainty from individual measurements, composite profiles were developed by grouping and averaging source profiles from the same category. The fractions of oxygenated volatile organic compounds (OVOC) were corrected during the compositing process for those profiles which used improper sampling and analyzing methods. Emissions of individual species were then lumped into species in different chemical mechanisms used in CTMs by applying mechanism-dependent species mapping tables, which overcomes the weakness of inaccurate mapping in previous studies. Emission estimates for individual NMVOC species differ between one and three orders of magnitude for some species when different sets of profiles are used, indicating that source profile is the most important source of uncertainties of individual species emissions. However, those differences are diminished in lumped species as a result of the lumping in the chemical mechanisms. Gridded emissions for eight chemical mechanisms at 30 min x 30 min resolution as well as the auxiliary data are available at < a href='http://mic.greenresource.cn/intex-b2006'target='_blank'> http://mic.greenresource.cn/intex-b2006 . The framework proposed in this work can be also used to develop speciated NMVOC emissions for other regions
Bivalve molluscs are descendants of an early-Cambrian lineage superbly adapted to benthic filter feeding. Adaptations in form and behavior are well recognized, but the underlying molecular mechanisms are largely unknown. Here, we investigate the genome, various transcriptomes, and proteomes of the scallop Chlamys farreri, a semi-sessile bivalve with well-developed adductor muscle, sophisticated eyes, and remarkable neurotoxin resistance. The scallop’s large striated muscle is energy-dynamic but not fully differentiated from smooth muscle. Its eyes are supported by highly diverse, intronless opsins expanded by retroposition for broadened spectral sensitivity. Rapid byssal secretion is enabled by a specialized foot and multiple proteins including expanded tyrosinases. The scallop uses hepatopancreas to accumulate neurotoxins and kidney to transform to high-toxicity forms through expanded sulfotransferases, probably as deterrence against predation, while it achieves neurotoxin resistance through point mutations in sodium channels. These findings suggest that expansion and mutation of those genes may have profound effects on scallop’s phenotype and adaptation.
Gnetophytes are an enigmatic gymnosperm lineage comprising three genera, Gnetum, Welwitschia and Ephedra, which are morphologically distinct from all other seed plants. Their distinctiveness has triggered much debate as to their origin, evolution and phylogenetic placement among seed plants. To increase our understanding of the evolution of gnetophytes, and their relation to other seed plants, we report here a high-quality draft genome sequence for Gnetum montanum, the first for any gnetophyte. By using a novel genome assembly strategy to deal with high levels of heterozygosity, we assembled >4 Gb of sequence encoding 27,491 protein-coding genes. Comparative analysis of the G. montanum genome with other gymnosperm genomes unveiled some remarkable and distinctive genomic features, such as a diverse assemblage of retrotransposons with evidence for elevated frequencies of elimination rather than accumulation, considerable differences in intron architecture, including both length distribution and proportions of (retro) transposon elements, and distinctive patterns of proliferation of functional protein domains. Furthermore, a few gene families showed Gnetum-specific copy number expansions (for example, cellulose synthase) or contractions (for example, Late Embryogenesis Abundant protein), which could be connected with Gnetum's distinctive morphological innovations associated with their adaptation to warm, mesic environments. Overall, the G. montanum genome enables a better resolution of ancestral genomic features within seed plants, and the identification of genomic characters that distinguish Gnetum from other gymnosperms. NATuRe PLANTS ArticlesNATurE PLANTs phylogenetic position of gnetophytes, with topologies differing depending on the type of sequence data (for example, plastid versus nuclear genes, nucleotide versus amino acid data) and analytical approach used (for example, maximum parsimony, maximum likelihood, Bayesian, multispecies coalescent based methods) [6][7][8] . Consequently, several possible hypotheses have been put forward that place gnetophytes as sister to (1) Pinaceae ('Gnepine' hypothesis); (2) cupressophytes ('Gnecup' hypothesis); (3) all conifers ('Gnetifer' hypothesis); (4) all other gymnosperms; or (5) all seed plants 9 . Currently, the emerging consensus, based on both older and more recent studies, and recently released data from the 1KP initiative (see https://sites.google.com/a/ualberta.ca/onekp/, and Wickett et al. 8 ), indicates that gnetophytes are sister to, or within, the conifers.So far, the availability of whole genome sequences for gymnosperms has been limited to conifers (specifically to Pinaceae) [10][11][12][13] and G. biloba 14 , with no whole genome assemblies available for the two remaining major seed plant lineages-cycads and gnetophytes. This deficiency, together with the conflicting phylogenetic evidence for relationships among these groups, is impeding our understanding of genome evolution across all seed plants. Here, we present a high-quality draft genome of Gnetum ...
Atherosclerosis is marked by an overt inflammatory infiltrate, with enhanced recruitment of monocytes/macrophages observed in both human and experimental atherosclerosis. We previously determined that monocyte chemoattractant protein 1 (MCP-1) accounts for virtually all of the chemotactic activity produced by vascular (aortic) smooth muscle cells in culture. We now report that arteries from a primate model of atherosclerosis with dietary-induced hypercholesterolemia exhibit increased levels of MCP-1 mRNA expression in vivo, whereas their normal counterparts demonstrate minimal MCP-1 expression. Furthermore, immunohistochemistry and in situ hybridization clearly indicate that the expression of MCP-1 protein and mRNA is in the smooth muscle cells of the medial layer of the artery and in monocytelike and smooth muscle-like cells found in the overlying intimal lesion. These studies indicate that one of the responses to dietary hypercholesterolemia is the expression of MCP-1 by vascular smooth muscle cells. This expression, when augmented with other cellular and molecular factors, could significantly contribute to the recruitment of monocytes/macrophages to the vessel wall.Atherosclerosis is a multistage disease involving invasion of the intima by smooth muscle cells (SMCs) from the media, followed by SMC proliferation and production of an extensive insoluble matrix including such connective tissue components as collagens, elastin, and proteoglycans (1). The two major lesions seen are the fatty streak and the atheromatous or fibrotic plaque. Evidence suggests that fatty streaks, seen in childhood, may progress to fibrotic lesions in adults. Both types of lesions are typified by macrophage invasion (2). Factors released by the macrophage have been shown to influence SMC migration, proliferation, and connective tissue gene expression (3-5). Thus a renewed appreciation of the role of the inflammatory process in coronary arteriosclerosis has emerged.Monocyte chemoattractant protein 1 (MCP-1) is a monomeric polypeptide that migrates in a gel with an estimated molecular mass of 9-15 kDa (6, 7). The various forms of MCP-1 result from differences in O-linked glycosylation and do not affect chemotactic activity (8, 9). Unlike other chemoattractants, MCP-1 is relatively specific for monocytes. Lymphocytes and polymorphonuclear leukocytes lack MCP-1 receptors and do not respond to MCP-1 (10). Previous in vitro studies have shown that this protein can either be secreted by normal cells such as endothelial cells (11) and SMCs (12) or by many tumor cell lines (6, 13). MCP-1 expression in most normal cell types occurs in response to proinflammatory factors such as interleukin 1, tumor necrosis factor a, and interferon y (11, 14). It has also been shown that minimally modified plasma low density lipoprotein stimulates MCP-1 production by human SMCs and endothelial cells in vitro (15). It has been suggested that macrophage/ monocyte recruitment in atherosclerosis occurs in response to a gradient of chemoattractants released ...
In recent years in a few Chinese megacities, fog events lasting one to a few days have been frequently associated with high levels of aerosol loading characterized by high sulfate (as high as 30 μg m(-3)), therefore termed as haze-fog events. The concomitant pollution characteristics include high gas-phase mixing ratios of SO2 (up to 71 ppbv) and NO2 (up to 69 ppbv), high aqueous phase pH (5-6), and smaller fog droplets (as low as 2 μm), resulting from intense emissions from fossil fuel combustion and construction activities supplying abundant Ca(2+). In this work, we use an observation-based model for secondary inorganic aerosols (OBM-SIA) to simulate sulfate formation pathways under conditions of haze-fog events encountered in Chinese megacities. The OBM analysis has identified, at a typical haze-fogwater pH of 5.6, the most important pathway to be oxidation of S(IV) by dissolved NO2, followed by the heterogeneous reaction of SO2 on the aerosol surface. The aqueous phase oxidation of S(IV) by H2O2 is a very minor formation pathway as a result of the high NOx conditions suppressing H2O2 formation. The model results indicate that the unique cocktail of high fogwater pH, high concentrations of NO2, SO2, and PM, and small fog droplets are capable of greatly enhancing sulfate formation. Such haze-fog conditions could lead to rapid sulfate production at night and subsequently high PM2.5 in the morning when the fog evaporates. Sulfate formation is simulated to be highly sensitive to fogwater pH, PM, and precursor gases NO2 and SO2. Such insights on major contributing factors imply that reduction of road dust and NOx emissions could lessen PM2.5 loadings in Chinese megacities during fog events.
The common practice of defining operational settings for Heating, Ventilation and Air Conditioning (HVAC) systems in buildings is to use fixed set points, which assume occupants have same and static comfort requirements. However, thermal comfort varies from person to person and also changes due to climatic variations or acclimation, making it dynamic. In addition, thermal comfort in transient conditions are different from the steady state conditions, which makes the prediction of thermal comfort more difficult. Thus, thermal comfort has to be monitored over time. In this paper, we present a novel infrared thermography based technique to monitor an individual's thermoregulation performance and thermal comfort levels by measuring the skin temperature on several points on human face, which has a high density of blood vessels and is not usually covered by clothing. Unlike other methods, our method requires no continuous user input or interaction. Our results demonstrate that the monitored facial points behave differently under the heat and cold stresses and it can be explained based on the underlying vascular territories. We define two heuristics to describe the thermoneutral zone based on the observed behaviors and estimate thermal comfort for individuals with 95% confidence level. Considerable variations are observed in the thermoregulation performance and uncomfortably cool conditions metrics between the males and females. Females' thermoregulation system responses are less sensitive to the perception of warm conditions. However, similar behaviors are observed for uncomfortably cool conditions across genders.
Gingival inflammation is initiated by bacterial colonization of the tooth surface. It is characterized by infiltration of mononuclear cells, a feature of many forms of chronic inflammation. Monocyte chemoattractant protein‐1 (MCP‐1) is the predominant monocyte chemoattractant secreted by a variety of cells in vitro. We examined MCP‐1 expression in chronic gingival inflammation by double antibody immunohistochemistry that utilized rabbit anti‐MCP‐1 antibody simultaneously with mouse monoclonal antibodies to specific cellular markers. MCP‐1 mRNA expression by fibroblasts in inflamed gingival tissues was examined by in situ hybridization. We report here that in human chronic gingival inflammation the principal cell type expressing MCP‐1 in dense inflammatory infiltrates is the mononuclear phagocyte. The cells expressing MCP‐1 in moderately inflamed areas and in adjacent areas to inflammatory infiltrates are mononuclear phagocytes and fibroblasts, while in areas of fibroblastic hyperplasia, MCP‐1 positive cells are predominantly fibroblasts. We also demonstrate that in moderately and highly inflamed areas, the extent of MCP‐1 expression is greater than that in adjacent normal/mildly inflamed areas. As the degree of inflammation increased, there is also a concomitant increase in the number of mononuclear phagocytes. Furthermore, it is apparent that most of the infiltrating monocytes/macrophages are positive for MCP‐1 in vivo. Our finding that MCP‐1 expression is unambiguously identified in fibroblasts suggests that they can play a role in host defense by initiating the recruitment of monocytes. In addition, the expression of chemokines such as MCP‐1 may represent a mechanism for amplification of inflammatory signals in gingival inflammation. J Periodontol 1995; 66:80–88.
Platelet-derived growth factor (PDGF) is mitogenic and chemotactic for osteoblastic cells in vitro. It is expressed during osseous wound healing and stimulates formation of new bone in vivo. PDGF stimulates cells by binding to specific cell surface receptors. The purpose of this study was to examine the effects of PDGF on osteoblastic proliferation and differentiation in long-term mineralizing cultures. Utilizing Northern blot analysis, we found that continuous PDGF treatment increased histone expression, indicative of enhanced proliferation, but suppressed osteoblast differentiation, demonstrated by inhibition of alkaline phosphatase, type I collagen, and osteocalcin expression. The inhibitory effect of PDGF on the differentiated function of osteoblasts was further established by findings that PDGF significantly inhibited nodule formation. The expression of PDGF receptors varied at different stages of culture. PDGF receptor mRNA expression increased when the cells had achieved a mature phenotype, during the stage of matrix maturation, and then decreased. However, as demonstrated by thymidine incorporation assays, the capacity of PDGF to stimulate DNA synthesis actually decreased during osteoblast maturation, as receptor expression increased. To investigate this apparent contradiction, tyrosyl phosphorylation and immunoblot assays were performed to assess changes in PDGF activation of their cognate receptors. The pattern of PDGF-induced tyrosyl phosphorylation remained relatively constant. This suggests that the diminished mitogenic activity of PDGF that occurs after osteoblast differentiation is regulated at a postreceptor level.
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