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Hydrobiologia - In shallow lakes, macrophytes have important effects on food webs, community structure and nutrient dynamics. For this reason they play a significant role in the restoration of... 相似文献
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G Del Boccio C Di Ilio E Casalone A Pennelli A Aceto P Sacchetta G Federici 《The Italian journal of biochemistry》1987,36(1):8-17
An anionic (pI 4.6) isoenzyme of glutathione transferase was purified to homogeneity from human thyroid by affinity chromatography followed by isoelectric focusing. The content of enzyme was calculated to constitute about 0.2% of soluble proteins. The enzyme is formed by two identical subunits of 23,000 daltons approximately. The thyroid transferase did not catalyze the reduction of peroxides. Physical, catalytic and immunological analyses demonstrated extensive similarities between the thyroid transferase and the transferase from placenta, erythrocytes and breast. On the other hand, the thyroid transferase appears catalytically different from transferase 7-7, even if both cross-react with the antibodies raised against human placenta transferase. 相似文献
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The species composition of the damselfly assemblage and the life history patterns of two Coenagrionidae (Ischnura elegans
and Cercion lindeni) were investigated along the urban tract of a river characterized by increasing organic pollution. The
assemblage was dominated by generalist species, usually recorded in lentic habitats, rather than by typical riverine species
and the proportion of the latter decrease at the most polluted sites. At the end of Winter, the mean size and in star distribution
were different between the sampling sites showing that the life history of both species examined were influenced by a degradation
of the environmental quality. A longer reproductive period, absence of diapause, and tolerance of low oxygen concentration
appear to be key factors that allow generalist species I. elegans and C. lindeni to predominate at the polluted sites.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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G Del Boccio A Pennelli E P Whitehead M Lo Bello R Petruzzelli G Federici G Ricci 《The Journal of biological chemistry》1991,266(21):13777-13782
7-Chloro-4-nitrobenzo-2-oxa-1,3-diazole reacts with two thiol groups of the dimeric horse erythrocyte glutathione transferase at pH 5.0, with strong inactivation reversible on dithiothreitol treatment. The inactivation kinetic follows a biphasic pattern, similar to that caused by other thiol reagents as recently reported. Both S-methylglutathione and 1-chloro-2,4-dinitrobenzene protect the enzyme from inactivation. Analysis of the reactive SH group-containing peptide gives the sequence Ala-Ser-Cys-Leu-Tyr, identical with that of the peptide that contains the reactive cysteine 47 of the human placental transferase. In the presence of glutathione, the enzyme is not inactivated by this reagent, but it catalyzes its conjugation to glutathione. At higher pH values, 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole reacts with 2 tyrosines/dimer and lysines, as well as with cysteines. Reaction with lysine seems essentially without effect on activity; whether the reactive tyrosines are important for activity could not be determined using this reagent only. However, 2 tyrosines among the 4 that are nitrated by tetranitro-methane are important for activity. 相似文献
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Giuliana Allegrucci Gianmaria Carchini Valentina Todisco Peter Convey Valerio Sbordoni 《Polar Biology》2006,29(4):320-326
The chironomid midges Belgica antarctica, Eretmoptera murphyi (subfamily Orthocladiinae) and Parochlus steinenii (subfamily Podonominae), are the only Diptera species currently found in Antarctica. The relationships between these species
and a range of further taxa of Chironomidae were examined by sequencing domains 1 and 3–5 of 28S ribosomal RNA. The resulting
molecular relationships between B. antarctica and E. murphyi, within Orthocladiinae, were highly supported by validation analyses, confirming their position within Chironomidae, as generated
by classical taxonomy. Within Podonominae, P. steinenii from the Maritime Antarctic was more closely related to material from sub-Antarctic South Georgia than to material from Patagonia.
Taking advantage of the availability of a molecular substitution rate calculated for this gene in Diptera, a dating of divergence
between our study taxa was tentatively established. The divergence dates obtained were 49 million years (Myr), between B. antarctica and E. murphyi, and 68.5 Myr between these species and the closest Orthocladiinae taxon tested from Patagonia, suggesting that B. antarctica and E. murphyi were representatives of an ancient lineage. As both are endemic to their respective tectonic microplates, their contemporary
distribution is, therefore, likely to have been shaped by vicariance rather than dispersal. 相似文献
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The absence of a rapid and inexpensive method for estimating macroinvertebrate individual biomass is a limit to the study of freshwater communities, given that traditional methods are time- and money-consuming. We propose an inexpensive method to quickly estimate individual biomass from video-recorded images of pond macroinvertebrates. We used a software that automatically measures several body dimensions (area, perimeter, minor and major axes) on each individual and linear regression to relate these body dimensions to dry weight. Area was found to be the best predictor of dry weight. The method allows individual measures of macroinvertebrates at a reasonable speed and accuracy, and may be useful for biomass size spectra or secondary production studies. 相似文献
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Gabriele Midolo Tomáš Herben Irena Axmanová Corrado Marcenò Ricarda Pätsch Helge Bruelheide Dirk Nikolaus Karger Svetlana Aćić Ariel Bergamini Erwin Bergmeier Idoia Biurrun Gianmaria Bonari Andraž Čarni Alessandro Chiarucci Michele De Sanctis Olga Demina Jürgen Dengler Tetiana Dziuba Giuliano Fanelli Emmanuel Garbolino Gianpietro Giusso del Galdo Friedemann Goral Behlül Güler Guillermo Hinojos-Mendoza Florian Jansen Borja Jiménez-Alfaro Attila Lengyel Jonathan Lenoir Aaron Pérez-Haase Remigiusz Pielech Vadim Prokhorov Valerijus Rašomavičius Eszter Ruprecht Solvita Rūsiņa Urban Šilc Željko Škvorc Zvjezdana Stančić Irina Tatarenko Milan Chytrý 《Global Ecology and Biogeography》2023,32(1):24-34
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Guido Grassi Gino Seravalle Francesco Scopelliti Raffaella Dell'Oro Luca Fattori Fosca Quarti‐Trevano Gianmaria Brambilla Ernesto L. Schiffrin Giuseppe Mancia 《Obesity (Silver Spring, Md.)》2010,18(1):92-98
Obese persons are at increased cardiovascular risk and exhibit increased arterial stiffness and impaired endothelial function of large‐ and medium‐size arteries. We hypothesized that normotensive subjects suffering from severe obesity would also present remodeling and endothelial dysfunction of small resistance arteries. A total of 16 lean (age: 49.6 ± 2.9 years, BMI: 22.9 ± 0.3 kg/m2, mean ± s.e.m.) and 17 age‐matched severely obese (BMI: 41.1 ± 2.3 kg/m2) normotensive subjects were investigated. None had glucose or lipid metabolic abnormalities except for insulin resistance. Resistance arteries, dissected from abdominal subcutaneous tissue, were assessed on a pressurized myograph. For superimposable blood pressure, the media thickness, media cross‐sectional area (CSA), and media‐to‐lumen ratio values of resistance arteries were markedly and significantly greater in obese compared to lean subjects (media thickness 26.3 ± 0.6 vs. 16.2 ± 0.6 µm, CSA 22,272 ± 1,339 vs. 15,183 ± 1,186 µm2, and media‐to‐lumen ratio 0.113 ± 0.006 vs. 0.059 ± 0.001, respectively, P < 0.01). Acetylcholine‐induced relaxation was impaired in vessels from obese subjects compared to the lean individuals (?40.4 ± 1.3%, P < 0.01), whereas endothelium‐independent vasorelaxation was similar in all groups. Stiffness of small arteries as assessed by the stress/strain relationship was similar in lean and severely obese subjects. We conclude that severe human obesity is associated with profound alterations in structural and functional characteristics of small arteries, which may be responsible for the presence of elevated cardiovascular risk and increased incidence of coronary, cerebrovascular and renal events reported in obesity. 相似文献