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1.
Measurements of regional net ecosystem exchange (NEE) were made over a period of 21 days in summer 2002 in the South‐Central part of the Netherlands and extrapolated to an area of 13 000 km2 using a combination of flux measurements made by a Sky Arrow ERA research aircraft, half‐hourly eddy covariance data from four towers, half‐hourly weather data recorded by three weather stations and detailed information on regional land use. The combination of this type of information allowed to estimate the net contribution of the terrestrial ecosystems to the overall regional carbon flux and to map dynamically the temporal and spatial variability of the fluxes. A regional carbon budget was calculated for the study period and the contributions of the different land uses to the overall regional flux, were assessed. Ecosystems were, overall, a small source of carbon to the atmosphere equivalent to to 0.23±0.025 g C m−2 day−1. When considered separately, arable and grasslands were a source of, respectively, 0.68±0.022 and 1.28±0.026 g C m−2 day−1. Evergreen and deciduous forests were instead a sink of −1.42±0.015 g C m−2 day−1. During the study period, forests offset approximately 3.5% of anthropogenic carbon emission estimates obtained from inventory data. Lacking of a robust validation, NEE values obtained with this method were compared with independent state of art estimates of the regional carbon balance that were obtained by applying a semi‐empirical model of NEE driven by MODIS satellite fAPAR data. The comparison showed an acceptable matching for the carbon balance of forest that was a sink in both cases, while a much larger difference for arable and grassland was found. Those ecosystems were a sink for satellite‐based estimates while they were a source for the combined aircraft and tower estimates. Possible causes of such differences are discussed and partly addressed. The importance of new methods for determining carbon balance at the regional scale, is outlined. 相似文献
2.
Wastewater from olive oil mill was decolorized (and its chemical oxygen demand reduced in static cultivation) using the fungiCoriolus versicolor, Funalia trogii, Phanerochœte chrysosporium andPleurotus sajor-caju. The effect of cotton stalk on decolorizing and COD removing capability was demonstrated.P. chrysosporium (in 20% medium with cotton stalk) reduced the COD by 48% and color by 58%,F. trogii (in 30% medium with cotton stalk) by 51 and 55%, respectively. 相似文献
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4.
Belma Turan Ertan Delilba§i Nejat Dalay §evki Sert Lale Afrasyap Ahmet Sayal 《Biological trace element research》1992,33(1-3):95-102
Selenium, aluminum, cadmium, and magnesium concentrations and gluthathione-peroxidase activities in sera of 35 healthy individuals,
30 renal transplants, and 30 hemodialysis patients were measured. Serum selenium, aluminum, and cadmium concentrations in
both groups of patients were higher than the controls (p<0.001), whereas the serum gluthathione-peroxidase levels were lower (p<0.001). According to our results, it can be concluded that the patients receiving hemodialysis are subjected to more toxic
elements than the transplantation patients. These findings imply that dietary selenium supplement may be suggested in renal
failure for the detoxification of elements, such as cadmium and mercury. The essential trace element selenium takes part not
only in the direct protection of endothelial cells against the accumulation of aggressive oxygen species, but also in the
preventions of the toxic effects of cadmium or in the modulation of the active calcium transport. 相似文献
5.
An ethnobotanical survey was made of the villages of the Ilica District, Erzurum Province, Turkey. The authors interviewed
130 people in 60 villages. The information so obtained was classified according to the use of plants for food, fuel, dye,
and construction materials, as well as for miscellaneous uses. All in all, this study revealed 60 plant taxa that were useful
to the villagers of this district. 相似文献
6.
Remote sensing of sun-induced fluorescence to improve modeling of diurnal courses of gross primary production (GPP) 总被引:4,自引:0,他引:4
ALEXANDER DAMM JAN ELBERS† RÉ ERLER‡ BENIAMINO GIOLI§ KARIM HAMDI‡ RONALD HUTJES† MARTINA KOSVANCOVA¶ MICHELE MERONI FRANCO MIGLIETTA§ RÉ MOERSCH‡ JOSE MORENO ANKE SCHICKLING†† RUTH SONNENSCHEIN THOMAS UDELHOVEN‡‡ SEBASTIAN van der LINDEN PATRICK HOSTERT UWE RASCHER‡ 《Global Change Biology》2010,16(1):171-186
Terrestrial gross primary production (GPP) is an important parameter to explore and quantify carbon fixation by plant ecosystems at various scales. Remote sensing (RS) offers a unique possibility to investigate GPP in a spatially explicit fashion; however, budgeting of terrestrial carbon cycles based on this approach still remains uncertain. To improve calculations, spatio-temporal variability of GPP must be investigated in more detail on local and regional scales. The overarching goal of this study is to enhance our knowledge on how environmentally induced changes of photosynthetic light-use efficiency (LUE) are linked with optical RS parameters. Diurnal courses of sun-induced fluorescence yield ( F Syield ) and the photochemical reflectance index of corn were derived from high-resolution spectrometric measurements and their potential as proxies for LUE was investigated. GPP was modeled using Monteith's LUE-concept and optical-based GPP and LUE values were compared with synoptically acquired eddy covariance data. It is shown that the diurnal response of complex physiological regulation of photosynthesis can be tracked reliably with the sun-induced fluorescence. Considering structural and physiological effects, this research shows for the first time that including sun-induced fluorescence into modeling approaches improves their results in predicting diurnal courses of GPP. Our results support the hypothesis that air- or spaceborne quantification of sun-induced fluorescence yield may become a powerful tool to better understand spatio-temporal variations of fluorescence yield, photosynthetic efficiency and plant stress on a global scale. 相似文献
7.
Ö. Ye§ilada 《World journal of microbiology & biotechnology》1995,11(5):601-602
Crystal Violet was decolourized by Coriolus versicolor, Funalia trogii, Laetiporus sulphureus and Phanerochaete chrysosporium ME446 by 92%, 82%, 86% and 62%, respectively, over 3 days. 相似文献
8.
GAIL TAYLOR MATTHEW J. TALLIS CHRISTIAN P. GIARDINA† KEVIN E. PERCY‡ FRANCO MIGLIETTA§ POOJA S. GUPTA¶ BENIAMINO GIOLI§ CARLO CALFAPIETRA BIRGIT GIELEN†† MARK E. KUBISKE‡‡ GIUSEPPE E. SCARASCIA-MUGNOZZA KATRE KETS§§ STEPHEN P. LONG¶¶ DAVID F. KARNOSKY¶ 《Global Change Biology》2008,14(2):264-275
Growing seasons are getting longer, a phenomenon partially explained by increasing global temperatures. Recent reports suggest that a strong correlation exists between warming and advances in spring phenology but that a weaker correlation is evident between warming and autumnal events implying that other factors may be influencing the timing of autumnal phenology. Using freely rooted, field‐grown Populus in two Free Air CO2 Enrichment Experiments (AspenFACE and PopFACE), we present evidence from two continents and over 2 years that increasing atmospheric CO2 acts directly to delay autumnal leaf coloration and leaf fall. In an atmosphere enriched in CO2 (by ~45% of the current atmospheric concentration to 550 ppm) the end of season decline in canopy normalized difference vegetation index (NDVI) – a commonly used global index for vegetation greenness – was significantly delayed, indicating a greener autumnal canopy, relative to that in ambient CO2. This was supported by a significant delay in the decline of autumnal canopy leaf area index in elevated as compared with ambient CO2, and a significantly smaller decline in end of season leaf chlorophyll content. Leaf level photosynthetic activity and carbon uptake in elevated CO2 during the senescence period was also enhanced compared with ambient CO2. The findings reveal a direct effect of rising atmospheric CO2, independent of temperature in delaying autumnal senescence for Populus, an important deciduous forest tree with implications for forest productivity and adaptation to a future high CO2 world. 相似文献
9.
§ahan Saygi Gönen Deniz Osman Kutsal Nevin Vural 《Biological trace element research》1991,31(3):209-214
Male Wistar rats (n:20), at 5 wk of age, were given cadmium in drinking water (10 mg/L water) for 52 wk; 8 males and 20 female rats, as controls, were given tap water. At the end of 28 and 40 wk, some of the cadmium-treated males and control group male rats were sacrificed for the histopathological examination of testis, kidney, and liver. At the end of 56 wk, histopathological examinations were performed in the same way. Liver, kidney, and testis cadmium levels were also determined by atomic absorption spectrophotometry. All the cadmium-treated male rats showed pathological testicular alterations, and liver and kidney damage after chronic exposure. Cadmium levels were found to be highest in the kidney (1.009 +/- 0.034 microgram/g wet tissue in the infertile group). At the end of the 52-wk period, reproductive capacity of the cadmium-treated rats was investigated and was found to be lost in 39.89% of the animals. 相似文献
10.
Jeremy L. Clark Carey B. Clark J. Christian Mason § 《Nucleosides, nucleotides & nucleic acids》2013,32(4):286-292
The novel pyrimidine nucleoside, (3 ′S)-3 ′-deoxy-3 ′-fluoro-3 ′-C-ethynylcytidine (1) was synthesized from cytidine in seven steps. The key step in the synthesis was the introduction of the tertiary fluorine at the 3 ′-position. Compound 1 was evaluated in vitro against several RNA viruses. 相似文献