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31.
Extensive grasslands are considered to be of high biodiversity value, but are under threat from intensification and abandonment. We studied butterfly species richness and abundance in 47 hay and grazing meadows in the Picos de Europa, northern Spain in 2004. Nine transects were walked around the perimeter of the meadows from the 1 June to 28 July with butterflies recorded to species or species-group. Land-use, abiotic, and sward variables were also recorded. Change in meadow extent was estimated by comparing a digital map of open meadows with a cadastral map with 1950s provenance. We found: A decrease in open area, mostly attributable to reduction in grazing meadows. 75 or more butterfly species with species richness principally, and positively, influenced by altitude and presence of scrub in the body of the meadow. Hay meadow management was a positive influence on richness of satyrids. When all butterflies were considered together, the only significant factor influencing abundance was Plantago lanceolata (−ve). For sub-groups of the butterfly community there was no consistent pattern, although P. lanceolata was identified as a (−ve) factor in relation to hesperiid, nymphalid, satyrid, and Viola-feeding fritillary groups. Several regression models included components that could be linked to abiotic influences (water, aspect, altitude) but many were indicative of abandonment or relaxation of management intensity (scrub, Pteridium aquilinum, Asphodelus albus), sward components, fragmentation (distance to nearest meadow, number of meadows within 100 m), and land use (hay management, summer grazing). The results are discussed in relation to changing socio-economics, including the potential impact of tourism, and the need for financial instruments to support extensive farming.  相似文献   
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Mack AA  Kroboth S  Rajesh D  Wang WB 《PloS one》2011,6(11):e27956
The methodology to create induced pluripotent stem cells (iPSCs) affords the opportunity to generate cells specific to the individual providing the host tissue. However, existing methods of reprogramming as well as the types of source tissue have significant limitations that preclude the ability to generate iPSCs in a scalable manner from a readily available tissue source. We present the first study whereby iPSCs are derived in parallel from multiple donors using episomal, non-integrating, oriP/EBNA1-based plasmids from freshly drawn blood. Specifically, successful reprogramming was demonstrated from a single vial of blood or less using cells expressing the early lineage marker CD34 as well as from unpurified peripheral blood mononuclear cells. From these experiments, we also show that proliferation and cell identity play a role in the number of iPSCs per input cell number. Resulting iPSCs were further characterized and deemed free of transfected DNA, integrated transgene DNA, and lack detectable gene rearrangements such as those within the immunoglobulin heavy chain and T cell receptor loci of more differentiated cell types. Furthermore, additional improvements were made to incorporate completely defined media and matrices in an effort to facilitate a scalable transition for the production of clinic-grade iPSCs.  相似文献   
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The deep sea, the largest ecosystem on Earth and one of the least studied, harbours high biodiversity and provides a wealth of resources. Although humans have used the oceans for millennia, technological developments now allow exploitation of fisheries resources, hydrocarbons and minerals below 2000 m depth. The remoteness of the deep seafloor has promoted the disposal of residues and litter. Ocean acidification and climate change now bring a new dimension of global effects. Thus the challenges facing the deep sea are large and accelerating, providing a new imperative for the science community, industry and national and international organizations to work together to develop successful exploitation management and conservation of the deep-sea ecosystem. This paper provides scientific expert judgement and a semi-quantitative analysis of past, present and future impacts of human-related activities on global deep-sea habitats within three categories: disposal, exploitation and climate change. The analysis is the result of a Census of Marine Life--SYNDEEP workshop (September 2008). A detailed review of known impacts and their effects is provided. The analysis shows how, in recent decades, the most significant anthropogenic activities that affect the deep sea have evolved from mainly disposal (past) to exploitation (present). We predict that from now and into the future, increases in atmospheric CO(2) and facets and consequences of climate change will have the most impact on deep-sea habitats and their fauna. Synergies between different anthropogenic pressures and associated effects are discussed, indicating that most synergies are related to increased atmospheric CO(2) and climate change effects. We identify deep-sea ecosystems we believe are at higher risk from human impacts in the near future: benthic communities on sedimentary upper slopes, cold-water corals, canyon benthic communities and seamount pelagic and benthic communities. We finalise this review with a short discussion on protection and management methods.  相似文献   
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Here we describe novel forms of structural integration between endo- and episymbiotic microbes and an unusual new species of snail from hydrothermal vents in the Indian Ocean. The snail houses a dense population of γ-proteobacteria within the cells of its greatly enlarged esophageal gland. This tissue setting differs from that of all other vent mollusks, which harbor sulfur-oxidizing endosymbionts in their gills. The significantly reduced digestive tract, the isotopic signatures of the snail tissues, and the presence of internal bacteria suggest a dependence on chemoautotrophy for nutrition. Most notably, this snail is unique in having a dense coat of mineralized scales covering the sides of its foot, a feature seen in no other living metazoan. The scales are coated with iron sulfides (pyrite and greigite) and heavily colonized by - and δ-proteobacteria, likely participating in mineralization of the sclerites. This novel metazoan-microbial collaboration illustrates the great potential of organismal adaptation in chemically and physically challenging deep-sea environments.  相似文献   
37.
Asthma is a disease characterized by reversible airway obstruction. An additional hallmark of chronic asthma is altered wound healing that leads to airway remodeling. Although beta-agonists are effective in treating the bronchospasm associated with asthma, their effects on airway wound healing, which are related to airway remodeling, are unknown. It has been demonstrated that beta-agonists can alter the signaling of epidermal growth factor (EGF) receptors, which are important in timely wound healing. Therefore, we hypothesized that the beta-agonist isoproterenol would affect wound healing. Using an in vitro scrape wound assay, we demonstrated that isoproterenol attenuates EGF-stimulated wound healing in 16HBE airway epithelial cell cultures. Through experiments with forskolin and cells overexpressing beta2-adrenergic receptor-yellow fluorescent protein, we show that attenuation is due to the accumulation of cAMP and the involvement of at least one additional pathway. Furthermore, attenuation is not due to a direct effect on the EGF receptor or to an alteration of the ERK/MAPK signaling cascade. Based on these results, we propose that isoproterenol may exert its effects through other MAPK signaling pathways (JNK and/or p38) or through parallel mechanisms. These results also demonstrate a problem of potential therapeutic relevance in which a commonly prescribed medication may alter wound healing and contribute to the remodeling of asthmatic airways.  相似文献   
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4-Azido-2-hydroxybenzoic acid (4-AzHBA), a novel photoactive benzoic acid derivative, has been synthesized and used as a photoprobe to identify the phenol binding site of UDP-glucuronosyltransferases (UGTs). Analysis of recombinant His-tag UGTs from the 1A family for their ability to glucuronidate p-nitrophenol (pNP) and 4-methylumbelliferone (4-MU) revealed that UGT1A10 shows high activity toward phenols and phenol derivatives. Purified UGT1A10 was photolabeled with 4-AzHBA, digested with trypsin, and analyzed by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF)-mass spectrometry. A single modified peak corresponding to amino acid residues 89-98 (EFMVFHAQWK) of UGT1A10 was identified. The attachment site of the 4-AzHBA probe was localized to the quadruplet Phe(90)-Met(91)-Val(92)-Phe(93) using ESI LC-MS/MS. Sequence alignment revealed that the Phe(90) and Phe(93) are conserved in UGT1A7-10. Site-directed mutagenesis of these two amino acids was then followed by kinetic analysis of the mutants with two phenolic substrates, pNP and 4-MU, containing one and two planar rings, respectively. Using the combination of photoaffinity labeling, enzymatic digestion, MALDI-TOF and LC-MS mass spectrometry, and site-directed mutagenesis, we have determined for the first time that Phe(90) and Phe(93) are directly involved in the catalytic activity of UGT1A10 toward 4-MU and pNP.  相似文献   
40.
Peri-cellular remodeling of mesenchymal extracellular matrices is considered a prerequisite for cell proliferation, motility and development. Here we demonstrate that membrane-type 3 MMP, MT3-MMP, is expressed in mesenchymal tissues of the skeleton and in peri-skeletal soft connective tissue. Consistent with this localization, MT3-MMP-deficient mice display growth inhibition tied to a decreased viability of mesenchymal cells in skeletal tissues. We document that MT3-MMP works as a major collagenolytic enzyme, enabling cartilage and bone cells to cleave high-density fibrillar collagen and modulate their resident matrix to make it permissive for proliferation and migration. Collectively, these data uncover a novel extracellular matrix remodeling mechanism required for proper function of mesenchymal cells. The physiological significance of MT3-MMP is highlighted in mice double deficient for MT1-MMP and MT3-MMP. Double deficiency transcends the combined effects of the individual single deficiencies and leads to severe embryonic defects in palatogenesis and bone formation incompatible with life. These defects are directly tied to loss of indispensable collagenolytic activities required in collagen-rich mesenchymal tissues for extracellular matrix remodeling and cell proliferation during embryogenesis.  相似文献   
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