30 research outputs found
Проблеми управління фінансовою безпекою підприємства
Expanding urbanization in estuaries and the increase in pollutants from anthropogenic point sources can affect nearby benthic assemblages. Using a paired impact-control design, we assessed the effects of pollution from anthropogenic point sources (marinas, storm-water drains, sewage outfalls and fish farms) on algal and sessile invertebrate recruits to pavers placed in an industrialized Tasmanian estuary. Species number and cover of native recruits were lower after 12 months at sites outside marinas relative to paired control sites, whereas non-native and cryptogenic recruits were significantly higher outside marinas and near sewage outfalls. The cover of fast-growing, opportunistic species was significantly higher at sites near fish farms and sewage outfalls, and the cover of native species was also greater at sites near sewage outfalls relative to the paired control sites. Our results suggest an increased management focus on controlling pollution from marinas and sewage outfalls is warranted to limit the spread of non-native and cryptogenic species
Single amino acid substitutions in either YhjD or MsbA confer viability to 3-deoxy-d- manno -oct-2-ulosonic acid-depleted Escherichia coli
The Escherichia coli K-12 strain KPM22, defective in synthesis of 3-deoxy-d- manno -oct-2-ulosonic acid (Kdo), is viable with an outer membrane (OM) composed predominantly of lipid IV A , a precursor of lipopolysaccharide (LPS) biosynthesis that lacks any glycosylation. To sustain viability, the presence of a second-site suppressor was proposed for transport of lipid IV A from the inner membrane (IM), thus relieving toxic side-effects of lipid IV A accumulation and providing sufficient amounts of LPS precursors to support OM biogenesis. We now report the identification of an arginine to cysteine substitution at position 134 of the conserved IM protein YhjD in KPM22 that acts as a compensatory suppressor mutation of the lethal δKdo phenotype. Further, the yhjD400 suppressor allele renders the LPS transporter MsbA dispensable for lipid IV A transmembrane trafficking. The independent derivation of a series of non-conditional KPM22-like mutants from the Kdo-dependent parent strain TCM15 revealed a second class of suppressor mutations localized to MsbA. Proline to serine substitutions at either residue 18 or 50 of MsbA relieved the Kdo growth dependence observed in the isogenic wild-type strain. The possible impact of these suppressor mutations on structure and function are discussed by means of a computationally derived threading model of MsbA.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75126/1/MMI_6074_sm_Figure_S1.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/75126/2/j.1365-2958.2007.06074.x.pd
Clinical quality measures for intraoperative and perioperative management in carpal tunnel surgery
A global assessment of the direct and indirect benefits of marine protected areas for coral reef conservation
Aim:
Marine protected areas (MPAs) are increasingly implemented to conserve or restore coral reef biodiversity, yet evidence of their benefits for enhancing coral cover is limited and variable.
Location:
30 MPAs worldwide and nearby sites (within 10 km).
Taxa:
Cover of key functional groups for coral (total, branching, massive and tabular), and algae (total, filamentous, foliose) and total biomass of reef fish trophic groups (excavator, scraper, browser, higher carnivore).
Methods:
We used a global dataset obtained using standardized survey methods at 465 sites associated with 30 MPAs in 28 ecoregions to test the effects of five key MPA attributes (>10 years old, well‐enforced, no‐take, large and isolated) on coral cover, algal cover and reef fish biomass. We also tested the direct (reducing disturbance by human activities) versus indirect pathways (increasing grazing potential through recovering populations of herbivorous fishes) by which MPAs can influence coral and algal cover.
Results:
Only well‐enforced, no‐take and old (>10 years) MPAs had higher total coral cover (response ratio 1.08–1.19×) than fished sites, mostly due to the increased cover of massive coral growth forms (1.34–2.06×). This effect arose through both the direct influence of protection and indirect benefits of depressed algal cover by recovering herbivorous fish biomass. Neither the direct (standardized coefficient = 0.06) nor indirect effects (standardized coefficient = 0.04) of no‐take protection on coral cover were particularly strong, likely reflecting regional differences in fishing gear, targeted species and trophic webs.
Conclusions:
MPAs promote the persistence of some functional groups of corals, and thus represent an important management tool, globally