22 research outputs found

    Effects of the Zebra Mussel on Nitrogen Dynamics and the Microbial Community at the Sediment-Water Interface

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    A flow-through experiment was conducted on intact cores of sediments from Saginaw Bay, Lake Huron, to examine how trophic interactions between filter-feeding bivalve mussels and microbial populations could affect nitrogen dynamics at the sediment-water interface. The zebra mussels used in this experiment removed a large proportion of protozoa and phytoplankton from the overlying water, particularly heterotrophic nanoplankton (up to 82%), while bacterial populations showed less change. A 3-fold decrease in the protozoan to bacterial carbon ratio corresponded to a 2.5-fold increase in relative ammonium removal rates as estimated from the dark loss of N-15-ammonium. Excretion by the bivalves also increased net ammonium flux to the water, thus elevating the total calculated areal ammonium removal rates to about B-fold over rates observed in the control treatment. These data suggest that filter-feeding bivalves may significantly affect nitrogen transformation rates near the sediment-water interface by excreting ammonium and altering the microbial food web structure at the sediment-water interface

    Poboljšana adaptivna pretvorba ostataka prilikom H.264/AVC video kodiranja bez gubitka kvalitete

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    The H.264/AVC was designed mainly for lossy video coding, the lossless coding of H.264 use bypass mode for DCT and quantization. Although sample-by-sample DPCM improves performance of coding, the benefit is limited in intra. In this paper, a new adaptive transform is proposed based on the character of 4x block residual coefficient\u27s distribution, which can be used both in intra and inter coding. The greatest strength of the proposed transform is the decorrelation without inflation versus dynamic range of input matrix. Due to the random distribution of residual coefficients, a specific transform is hard to play a positive impact on them. Therefore, several transforms of different directions will be implemented simultaneously, and the most efficient one will be determined by a proposed mechanism. Then, by means of statistic method, a new scan order is designed for CAVLC entropy encoder, cooperating with corresponding transform. The simulation results show that based on the fast algorithm of proposed method, the bit saving achieves about 7.41% bit saving in intra coding and 10.47% in inter, compared with H.264-LS.H.264/AVC je napravljen prvenstveno za kodiranje videa uz gubitak kvalitete, dok kodiranje H.264 bez gubitka kvalitete koristi zaobilazni mod za DCT i kvantizaciju. Iako uzorak-po-uzorak (DPCM) kvantizacija poboljšava performanse kodiranja, dobitak je ograničen. U ovom radu predlaže se nova adaptivna transformacija koja se zasniva na znakovima od 4x4 blokova distribucije ostataka koeficijenata, koja može koristiti i unutarnje i među kodiranje. Najveća snaga predložene transformacije je u nekoreliranosti bez inflacije protiv dinamičke veličine ulazne matrice. Radi slučajne distribucije ostataka koeficijenata, teško je postići da određena transformacija ima pozitivan učinak na njih. Iz tog razloga istovremeno je implementirano nekoliko transformacija različitih pristupa, te je korištenjem predloženog mehanizma odabrana najefikasnija. Zatim je, korištenjem statističke metode, dizajniran novi poredak snimanja za CAVLC entropijski enkoder, koji surađuje s odgovarajućom transformacijom. Rezultati simulacija pokazuju da korištenjem brzog algoritma predložene metode dolazi do smanjenja korištenih bitova od 7.41% kod među kodiranja i 10.47% prilikom unutarnjeg kodiranja u usporedbi s H.264-LS

    Analysis of heavy metals in the conversion of lake sediment and restaurant waste by black soldier fly (Hermetia illucens)

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    The risk posed by heavy metals makes it difficult to dispose of sediment contaminants from dredging lakes in China. Black soldier fly (Hermetia illucens) can convert organic waste, such as restaurant waste and lake sediment, to high-value-added protein feed and fertilizer. Experimental groups were formed in this study to explore the conversion of heavy metals present in the mixture of restaurant waste and lake sediment by black soldier fly larvae (BSFL). The results demonstrated that BSFL could survive in pure sediment with an 84.76% survival rate. Relative to the substrate, BSFL could accumulate 70-90% zinc (Zn), chromium (Cr), copper (Cu), and 20-40% cadmium (Cd) and lead (Pb). The experimental group 2:3, with 40% lake sediment and 60% restaurant waste, was the best group after conversion for 15 days, which showed a 95.24% survival rate of BFSL, 82.20 mg average weight of BFSL, 8.92 mm average length of BFSL, with varying content of heavy metals such as Cu (43.22 mg/kg), Zn (193.31 mg/kg), Cd (1.58 mg/kg), Cr (25.30 mg/kg) Cr, and Pb (38.59 mg/kg) in BSFL. Furthermore, the conversion residue conforms to the relevant standards of organic fertilizer in China and can be used as organic fertilizer. Overall, the present study shows that black soldier flies can improve the resource utilization of lake sediment, especially by reducing the effect of heavy metals

    Polysaccharide Extracted from Laminaria japonica

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    This study aimed to determine the effect of topically applied Laminaria polysaccharide (LP) on skin aging. We applied ointment containing LP (10, 25, and 50 μg/g) or vitamin E (10 μg/g) to the dorsal skin of aging mice for 12 months and young control mice for 4 weeks. Electron microscopy analysis of skin samples revealed that LP increased dermal thickness and skin collagen content. Tissue inhibitor of metalloprotease- (TIMP-) 1 expression was upregulated while that of matrix metalloproteinase- (MMP-) 1 was downregulated in skin tissue of LP-treated as compared to untreated aging mice. Additionally, phosphorylation of c-Jun N-terminal kinase (JNK) and p38 was higher in aging skin than in young skin, while LP treatment suppressed phospho-JNK expression. LP application also enhanced the expression of antioxidative enzymes in skin tissue, causing a decrease in malondialdehyde levels and increases in superoxide dismutase, catalase, and glutathione peroxidase levels relative to those in untreated aging mice. These results indicate that LP inhibits MMP-1 expression by preventing oxidative stress and JNK phosphorylation, thereby delaying skin collagen breakdown during aging

    Atmospheric phosphorus in the northern part of Lake Taihu, China

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    Eutrophication, which has been linked to enhanced nutrient loading in lakes, estuarine and coastal waters, is common to many water bodies in China, including Lake Taihu. The atmosphere is an important and growing source of new nutrients entering water bodies. To assess the impact of atmospheric phosphorus (P) on water quality of Lake Taihu, we have estimated the atmospheric input of P by measuring its concentrations in aerosols and in rainwater. Samples were collected at the northeastern part of the lake. The P concentration in total suspended particle ranged from 0.054 to 0.300 mu g m(-3). Concentrations of P in aerosols in the winter and autumn samples were higher than those in the spring and summer samples. Soluble inorganic P (SIP), which provides direct nutrient sources to algae, accounts for 4.9%-83.4% of the total P. Principal Component Analysis of the measured aerosol constituents and examination of inter-species correlation indicate that SIP was correlated with elemental carbon, water soluble organic carbon, NO(3)(-), and Ca(2+). Such correlations could be explained if two nearby coal-fired power plants were a major aerosol P sources. The average concentration of the total P in rain water samples was 0.082 +/- 0.058 mg P/L. The annual deposition flux of P into the northern part of Lake Taihu was estimated to be in the range of 0.04-0.44 kg ha(-1) year(-1) through dry deposition and 0.33 kg ha(-1) year(-1) through wet deposition. The combined wet and dry deposition was less than 8% of riverine P input, therefore the atmospheric deposition was only a minor contributor to P in Lake Taihu at the time of this study. (C) 2011 Elsevier Ltd. All rights reserved

    Role of RING-Type E3 Ubiquitin Ligases in Inflammatory Signalling and Inflammatory Bowel Disease

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    Ubiquitination is a three-step enzymatic cascade for posttranslational protein modification. It includes the ubiquitin-activating enzyme (E1), ubiquitin-conjugating enzyme (E2), and ubiquitin ligase (E3). RING-type E3 ubiquitin ligases catalyse the posttranslational proteolytic and nonproteolytic functions in various physiological and pathological processes, such as inflammation-associated signal transduction. Resulting from the diversity of substrates and functional mechanisms, RING-type ligases regulate microbe recognition and inflammation by being involved in multiple inflammatory signalling pathways. These processes also occur in autoimmune diseases, especially inflammatory bowel disease (IBD). To understand the importance of RING-type ligases in inflammation, we have discussed their functional mechanisms in multiple inflammation-associated pathways and correlation between RING-type ligases and IBD. Owing to the limited data on the biology of RING-type ligases, there is an urgent need to analyse their potential as biomarkers and therapeutic targets in IBD in the future

    Use of Extreme Vertices Method for Analysis of How Proportional Composition Affects Component Interactions and Product Distribution during Hydrothermal Treatment

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    The interaction among three biomass components (hemicellulose, cellulose, and lignin) in an autoclave was studied based on the extreme vertices of a constrained region that had a significant effect on the distribution and characteristics of the products. The mathematical model of the three components was established according to the yield distribution. Based on the model, the biomass components and the hydrothermal characteristics of biomass were predicted. Subsequently, the contents of the main biomass components were analyzed, thus eliminating the complicated testing process and providing a convenient and reliable calculation tool for determining the three biomass components. The gaseous products showed that products from cellulose hydrolysis promoted hemicellulose hydrolysis and generated large amounts of CO2. The lignin content, as well as the low cellulose and hemicellulose contents, inhibited the acids and ketones in light oil. In addition, the interaction among cellulose, hemicellulose, and lignin inhibited the production of acids in heavy oil and promoted phenolic synthesis. A series of hydrolysis product reactions such as polymerization and condensation were increased to produce a char at a high degree of aromatization by the interaction among the three components
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