Genome sequence of Aedes aegypti, a major arbovirus vector     

Nene V  Wortman JR  Lawson D  Haas B  Kodira C  Tu ZJ  Loftus B  Xi Z  Megy K  Grabherr M  Ren Q  Zdobnov EM  Lobo NF  Campbell KS  Brown SE  Bonaldo MF  Zhu J  Sinkins SP  Hogenkamp DG  Amedeo P  Arensburger P  Atkinson PW  Bidwell S  Biedler J  Birney E  Bruggner RV  Costas J  Coy MR  Crabtree J  Crawford M  Debruyn B  Decaprio D  Eiglmeier K  Eisenstadt E  El-Dorry H  Gelbart WM  Gomes SL  Hammond M  Hannick LI  Hogan JR  Holmes MH  Jaffe D  Johnston JS  Kennedy RC  Koo H  Kravitz S  Kriventseva EV  Kulp D  Labutti K  Lee E  Li S  Lovin DD 《Science (New York, N.Y.)》2007,316(5832):1718-1723

We present a draft sequence of the genome of Aedes aegypti, the primary vector for yellow fever and dengue fever, which at approximately 1376 million base pairs is about 5 times the size of the genome of the malaria vector Anopheles gambiae. Nearly 50% of the Ae. aegypti genome consists of transposable elements. These contribute to a factor of approximately 4 to 6 increase in average gene length and in sizes of intergenic regions relative to An. gambiae and Drosophila melanogaster. Nonetheless, chromosomal synteny is generally maintained among all three insects, although conservation of orthologous gene order is higher (by a factor of approximately 2) between the mosquito species than between either of them and the fruit fly. An increase in genes encoding odorant binding, cytochrome P450, and cuticle domains relative to An. gambiae suggests that members of these protein families underpin some of the biological differences between the two mosquito species.  相似文献   

Geogenic and agricultural controls on the geochemical composition of European agricultural soils     

Rémon Saaltink  Jasper Griffioen  Gerben Mol  Manfred Birke 《Journal of Soils and Sediments》2014,14(1):121-137

Purpose

Concern about the environmental impact of agriculture caused by intensification is growing as large amounts of nutrients and contaminants are introduced into the environment. The aim of this paper is to identify the geogenic and agricultural controls on the elemental composition of European, grazing and agricultural soils.

Materials and methods

Robust factor analysis was applied to data series for Al, B, Ca, Cd, Co, Cu, Fe, K, Mg, Mn, Na, Ni, P, S, Se, Sr, U, Zn (ICP-MS) and SiO2, K2O, Na2O, Fe2O3, Al2O3 (XRF) based on the European GEMAS dataset. In addition, the following general soil properties were included: clay content, pH, chemical index of alteration (CIA), loss on ignition (LOI), cation exchange capacity (CEC), total organic carbon (TOC) and total carbon and total sulfur. Furthermore, this dataset was coupled to a dataset containing information of historic P₂O₅ fertilization across Europe. Also, a mass balance was carried out for Cd, Cu and Zn to determine if concentrations of these elements found in the soils have their origin in historic P₂O₅ fertilization.

Results and discussion

Seven geogenic factors and one agricultural factor were found of which four prominent ones (all geogenic): chemical weathering, reactive iron-aluminum oxide minerals, clay minerals and carbonate minerals. Results for grazing and agricultural soils were near identical, which further proofs the prominence of geogenic controls on the elemental composition. When the cumulative amount of P₂O₅ fertilization was considered, no extra agriculture-related factors became visible. The mass balance confirms these observations.

Conclusions

Overall, the geological controls are more important for the soil chemistry in agricultural and grazing land soils than the anthropogenic controls.  相似文献   

Phosphorus dynamics in peat‐based substrates     

Azizollah Khandan‐Mirkohi  Manfred K. Schenk 《植物养料与土壤学杂志》2008,171(5):804-809

The mobility of nutrients in soils is well characterized, whereas little information is available for common horticultural substrates based on peat. Aim of the current study was to investigate the mobility and dynamics of phosphorus (P) as well as the parameters involved in P transport to plant roots in peat‐based substrates. A series of experiments was run to determine the impedance factor (f) and the buffer power (b). The impedance factor was determined for black peat and black peat mixed with 20% and 40% (v/v) of mineral component at volumetric water content (θ) of 40%, 50%, 60%, and 70% and at different diffusion time. Buffer power was calculated for black peat and black peat mixed with 20% (v/v) of seven different mineral components. Phosphorus was applied at rates of 0, 35, and 100 mg (L substrate^–1), respectively. The impedance factor was not affected by addition of the mineral component to peat. However, f increased from 0.03 to 0.2, by increasing θ from 40% to 60%, indicating that water content has a significant effect on this parameter. Substrate‐solution P ranged from 0.3 to 27 and from 1 to 95 mg P (L solution)^–1 for the P‐application rate of 35 and 100 mg P (L substrate)^–1, respectively. Buffer power of the substrates ranged from 1 to 17.25 depending on the mineral component, and it was positively correlated with oxalate‐soluble Fe and Al in the substrate. The calculated effective diffusion coefficient for P in the substrate was in the range of 10^–7 to 10^–8 cm² s^–1. This high value could be attributed mostly to the low buffer power rather than to the high impedance factor.  相似文献   

Composition of beer by 1H NMR spectroscopy: effects of brewing site and date of production     

Almeida C  Duarte IF  Barros A  Rodrigues J  Spraul M  Gil AM 《Journal of agricultural and food chemistry》2006,54(3):700-706

A principal component analysis (PCA) of 1H NMR spectra of beers differing in production site (A, B, C) and date is described, to obtain information about composition variability. First, lactic and pyruvic acids contents were found to vary significantly between production sites, good reproducibility between dates being found for site A but not for sites B and C beers. Second, site B beers were clearly distinguished by the predominance of linear dextrins, while A and C beers were richer in branched dextrins. Carbohydrate reproducibility between dates is poorer for site C with dextrin branching degree varying significantly. Finally, all production sites were successfully distinguished by their contents in adenosine/inosine, uridine, tyrosine/tyrosol, and 2-phenylethanol, reproducibility between dates being again poorer for site C. Interpretation of the above compositional differences is discussed in terms of the biochemistry taking place during brewing, and possible applications of the method in brewing process control are envisaged.  相似文献   

Metabolism of curcuminoids in tissue slices and subcellular fractions from rat liver     

Hoehle SI  Pfeiffer E  Sólyom AM  Metzler M 《Journal of agricultural and food chemistry》2006,54(3):756-764

Curcumin and its natural congeners are of current interest because of their putative anti-inflammatory and anticarcinogenic activities, but knowledge about their metabolic fate is scant. In the present study conducted with precision-cut liver slices from male and female Sprague-Dawley rats, five reductive but no oxidative metabolites of curcumin and its demethoxy and bis-demethoxy analogues were observed and identified by HPLC and GC-MS analysis, mostly by comparison with authentic reference compounds. The major reductive metabolites were the hexahydrocurcuminoids in both male and female rat liver slices, whereas male rats formed more octahydro than tetrahydro metabolites and female rats more tetrahydro- than octahydrocurcuminoids. Tetrahydro, hexahydro, and octahydro metabolites were predominantly present as glucuronides, but a significant proportion of sulfate conjugates was also observed. The lack of formation of oxidative metabolites of curcumin and the ready generation of reductive metabolites were confirmed using rat liver microsomes and cytosol, respectively. Results of enzymatic hydrolysis studies conducted under various conditions revealed that curcumin and demethoxycurcumin are chemically less stable than bis-demethoxycurcumin, whereas the reductive metabolites of all three curcuminoids are stable compounds. This is the first report on the metabolism of demethoxycurcumin and bis-demethoxycurcumin. In view of the chemical instability of the parent curcuminoids, it is proposed to use their major phase I metabolites, that is, the stable hexahydro products, as biomarkers for exposure in clinical studies.  相似文献   

Quantitative analysis of tylosin in eggs by high performance liquid chromatography with electrospray ionization tandem mass spectrometry: residue depletion kinetics after administration via feed and drinking water in laying hens     

Hamscher G  Limsuwan S  Tansakul N  Kietzmann M 《Journal of agricultural and food chemistry》2006,54(24):9017-9023

Maximum residue limits (MRLs) have been established by the European Union when tylosin is used therapeutically. They are fixed at 200 microg/kg for eggs. A highly sensitive and selective quantitative liquid chromatography electrospray ionization tandem mass spectrometry (LC/ESI/MS/MS) method suitable for monitoring tylosin residues in eggs to determine its depletion kinetics was developed and validated. For sample pretreatment all samples were liquid-liquid extracted with citrate buffer (pH 5.0) and acetonitrile. Liquid chromatographic separation was carried out on a reversed phase C18 column employing a 0.5% formic acid/acetonitrile gradient system. The tylosin recovery in eggs at a concentration range from 1.0-400 microg/kg was >82% with relative standard deviations between 1.5 and 11.0%. In two experimental studies administrating tylosin via feed (final dosage: 1.5 g/kg) or drinking water (final dosage: 0.5 g/L), no residues above the MRL were found during and after treatment. Moreover, all samples were well below the actual MRL of 200 microg/kg. Therefore, our residue data suggest that a withholding period for eggs is not required when laying hens are treated with tylosin in recommended dosages via feed or drinking water. Keywords: Tylosin; residue; depletion; laying hen; withholding period; mass spectrometry.  相似文献   

Elemental compositions of comet 81P/Wild 2 samples collected by Stardust     

Flynn GJ  Bleuet P  Borg J  Bradley JP  Brenker FE  Brennan S  Bridges J  Brownlee DE  Bullock ES  Burghammer M  Clark BC  Dai ZR  Daghlian CP  Djouadi Z  Fakra S  Ferroir T  Floss C  Franchi IA  Gainsforth Z  Gallien JP  Gillet P  Grant PG  Graham GA  Green SF  Grossemy F  Heck PR  Herzog GF  Hoppe P  Hörz F  Huth J  Ignatyev K  Ishii HA  Janssens K  Joswiak D  Kearsley AT  Khodja H  Lanzirotti A  Leitner J  Lemelle L  Leroux H  Luening K  Macpherson GJ  Marhas KK  Marcus MA  Matrajt G  Nakamura T  Nakamura-Messenger K  Nakano T  Newville M 《Science (New York, N.Y.)》2006,314(5806):1731-1735

We measured the elemental compositions of material from 23 particles in aerogel and from residue in seven craters in aluminum foil that was collected during passage of the Stardust spacecraft through the coma of comet 81P/Wild 2. These particles are chemically heterogeneous at the largest size scale analyzed ( approximately 180 ng). The mean elemental composition of this Wild 2 material is consistent with the CI meteorite composition, which is thought to represent the bulk composition of the solar system, for the elements Mg, Si, Mn, Fe, and Ni to 35%, and for Ca and Ti to 60%. The elements Cu, Zn, and Ga appear enriched in this Wild 2 material, which suggests that the CI meteorites may not represent the solar system composition for these moderately volatile minor elements.  相似文献   

p53 regulates mitochondrial respiration   总被引：4，自引：0，他引：4  

Matoba S  Kang JG  Patino WD  Wragg A  Boehm M  Gavrilova O  Hurley PJ  Bunz F  Hwang PM 《Science (New York, N.Y.)》2006,312(5780):1650-1653

The energy that sustains cancer cells is derived preferentially from glycolysis. This metabolic change, the Warburg effect, was one of the first alterations in cancer cells recognized as conferring a survival advantage. Here, we show that p53, one of the most frequently mutated genes in cancers, modulates the balance between the utilization of respiratory and glycolytic pathways. We identify Synthesis of Cytochrome c Oxidase 2 (SCO2) as the downstream mediator of this effect in mice and human cancer cell lines. SCO2 is critical for regulating the cytochrome c oxidase (COX) complex, the major site of oxygen utilization in the eukaryotic cell. Disruption of the SCO2 gene in human cancer cells with wild-type p53 recapitulated the metabolic switch toward glycolysis that is exhibited by p53-deficient cells. That SCO2 couples p53 to mitochondrial respiration provides a possible explanation for the Warburg effect and offers new clues as to how p53 might affect aging and metabolism.  相似文献   

Effects of detritivorous invertebrates on the decomposition of rice straw: evidence from a microcosm experiment   总被引：1，自引：0，他引：1  

Jörn Panteleit  Finbarr G. Horgan  Manfred Türke  Anja Schmidt  Martin Schädler  Michael Bacht  Roland Brandl  Stefan Hotes 《Paddy and Water Environment》2018,16(2):279-286

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Characterization of Functional Properties of Gluten Proteins in Spelt Cultivars Using Rheological and Quality Factor Measurements     

Tilman J. Schober  Charmaine I. Clarke  Manfred Kuhn 《Cereal Chemistry》2002,79(3):408-417

Wet glutens of 27 European spelt (Triticum aestivum ssp. spelta (L.) Thell.) cultivars were examined using fundamental rheological methods (oscillatory and creep tests) in conjunction with the determination of moisture contents of these glutens and the wet gluten contents of the flours. Furthermore, SDS sedimentation volumes were determined. A special baking test for spelt was developed that encompassed the characteristic elements used in the production of traditional German spelt speciality breads. Various significant correlations between gluten properties and baking results were found for three sets of spelt cultivars obtained from different demographic locations and years of harvest. Furthermore, the relationship between baking results (response) and gluten properties (predictors) could be modeled quite well with the help of multiple linear regression analysis. Radar charts used to profile the gluten properties of a particular cultivar showed a great amount of diversity within the spelt material, but there were also similarities between several cultivars. The differences between spelt cultivars should be taken into account when characterizing spelt in general terms or when comparing spelt and modern wheat.  相似文献