Distributions of microbial activities in deep subseafloor sediments   总被引：1，自引：0，他引：1  

D'Hondt S  Jørgensen BB  Miller DJ  Batzke A  Blake R  Cragg BA  Cypionka H  Dickens GR  Ferdelman T  Hinrichs KU  Holm NG  Mitterer R  Spivack A  Wang G  Bekins B  Engelen B  Ford K  Gettemy G  Rutherford SD  Sass H  Skilbeck CG  Aiello IW  Guèrin G  House CH  Inagaki F  Meister P  Naehr T  Niitsuma S  Parkes RJ  Schippers A  Smith DC  Teske A  Wiegel J  Padilla CN  Acosta JL 《Science (New York, N.Y.)》2004,306(5705):2216-2221

Diverse microbial communities and numerous energy-yielding activities occur in deeply buried sediments of the eastern Pacific Ocean. Distributions of metabolic activities often deviate from the standard model. Rates of activities, cell concentrations, and populations of cultured bacteria vary consistently from one subseafloor environment to another. Net rates of major activities principally rely on electron acceptors and electron donors from the photosynthetic surface world. At open-ocean sites, nitrate and oxygen are supplied to the deepest sedimentary communities through the underlying basaltic aquifer. In turn, these sedimentary communities may supply dissolved electron donors and nutrients to the underlying crustal biosphere.  相似文献   

AAAS Meetings: A Progress Report     

Bert WG 《Science (New York, N.Y.)》1969,163(3869):767

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High-probability uniquantal transmission at excitatory synapses in barrel cortex     

Silver RA  Lubke J  Sakmann B  Feldmeyer D 《Science (New York, N.Y.)》2003,302(5652):1981-1984

The number of vesicles released at excitatory synapses and the number of release sites per synaptic connection are key determinants of information processing in the cortex, yet they remain uncertain. Here we show that the number of functional release sites and the number of anatomically identified synaptic contacts are equal at connections between spiny stellate and pyramidal cells in rat barrel cortex. Moreover, our results indicate that the amount of transmitter released per synaptic contact is independent of release probability and the intrinsic release probability is high. These properties suggest that connections between layer 4 and layer 2/3 are tuned for reliable transmission of spatially distributed, timing-based signals.  相似文献   

The structure of a human p110alpha/p85alpha complex elucidates the effects of oncogenic PI3Kalpha mutations     

Huang CH  Mandelker D  Schmidt-Kittler O  Samuels Y  Velculescu VE  Kinzler KW  Vogelstein B  Gabelli SB  Amzel LM 《Science (New York, N.Y.)》2007,318(5857):1744-1748

PIK3CA, one of the two most frequently mutated oncogenes in human tumors, codes for p110alpha, the catalytic subunit of a phosphatidylinositol 3-kinase, isoform alpha (PI3Kalpha, p110alpha/p85). Here, we report a 3.0 angstrom resolution structure of a complex between p110alpha and a polypeptide containing the p110alpha-binding domains of p85alpha, a protein required for its enzymatic activity. The structure shows that many of the mutations occur at residues lying at the interfaces between p110alpha and p85alpha or between the kinase domain of p110alpha and other domains within the catalytic subunit. Disruptions of these interactions are likely to affect the regulation of kinase activity by p85 or the catalytic activity of the enzyme, respectively. In addition to providing new insights about the structure of PI3Kalpha, these results suggest specific mechanisms for the effect of oncogenic mutations in p110alpha and p85alpha.  相似文献   

Molecular biology. Little molecules with big goals     

O'Malley BW 《Science (New York, N.Y.)》2006,313(5794):1749-1750

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Changes in cytokine profiles following treatment with food allergen‐specific sublingual immunotherapy in dogs with adverse food reactions          下载免费PDF全文

Elisa Maina  Bert Devriendt  Eric Cox 《Veterinary dermatology》2017,28(6):612-e149

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Phenotyping of productivity and resilience in sweetpotato under water stress through UAV-based multispectral and thermal imagery in Mozambique     

David A. Ramírez  Wolfgang Grüneberg  Maria I. Andrade  Bert De Boeck  Hildo Loayza  Godwill S. Makunde  Johan Ninanya  Javier Rinza  Simon Heck  Hugo Campos 《Journal of Agronomy and Crop Science》2023,209(1):41-55

Sweetpotato is a crucial crop to guarantee food security in sub-Saharan Africa, and drought events are considered one of the most critical factors affecting sweetpotato productivity in this region. In this study, airborne imagery based on reflectance (NDVI, CI_red-edge) and canopy temperature minus air temperature (dT) indices was used to characterize sweetpotato genotypes under drought treatments in Mozambique. Two field experiments established in rainy/hot (Trial A) and dry/cool (Trial B) seasons were assessed. In Trial A, 24 genotypes were subjected to early- (ESD), mid- (MSD) and late-season (LSD) drought stress treatments and compared against a control. In Trial B, 120 genotypes were subjected to LSD only. The percentage of reduction in vine weight (PR_VW) under drought was related primarily to temporal variation of NDVI and CI, regardless of drought treatment and seasons. dT in relation to control (dT_Amp) was associated with PR_VW in ESD-Trial A and LSD-Trial B, whereas under LSD-Trial A, dT_Amp was related to total fresh storage root weight (TRW). During the rainy/hot season, higher TRW reduction was promoted under ESD; however, under LSD, it was possible to identify productive genotypes able to withstand drought stress, highlighting their relevance for drought-tolerance selection purposes.  相似文献   

Electrical stunning of farmed Atlantic cod Gadus morhua L.: a comparison of an industrial and experimental method     

Hanne Digre  Ulf Erikson  Ekrem Misimi  Bert Lambooij  Hans Van De Vis 《Aquaculture Research》2010,41(8):1190-1202

An industrial and experimental electrical method for stunning farmed Atlantic cod in air and seawater (SW), respectively, were compared. The impacts of sedation with AQUI‐S^? and exercise to exhaustion before electrical stunning were also assessed to monitor the possible depletion of rested muscle energy levels by electrical stunning. Stress (blood glucose, haematocrit, muscle pH, muscle excitability, high‐energy phosphates and rigor mortis) and flesh quality (fillet texture, colour, liquid leakage (LL), gaping, residual blood and K‐value) were assessed. For the industrial stunning method, an average of 41 V, 0.2 A dc was applied to individual cod for 18–27 s. For the SW method, a bipolar square wave current (170 Hz, 33% duty cycle) was applied for 5 s. After stunning, recovery was prevented by exsanguination in chilled SW. There were no differences (P>0.05) between the two stunning methods except for a higher ultimate fillet pH for cod stunned in air 8 days postmortem. Exercise before stunning depleted muscle energy levels at slaughter, increased LL and fillets had redder and darker flesh after storage on ice for 8 days. Electrical stunning (in air) of AQUI‐S^?‐treated fish partly depleted muscle energy levels (pH 7.3, ATP 18.7 μmol g^?1, PCr 70.1 μmol g^?1). However, flesh quality was not affected. Unless pre‐rigor filleting is the chosen processing strategy, electrical stunning of cod seems to be a promising stunning method.  相似文献