Search results for "otos"
showing 10 items of 857 documents
Insensitivity of Tree-Ring Growth to Temperature and Precipitation Sharpens the Puzzle of Enhanced Pre-Eruption NDVI on Mt. Etna (Italy)
2017
On Mt. Etna (Italy), an enhanced Normalized Difference in Vegetation Index (NDVI) signature was detected in the summers of 2001 and 2002 along a distinct line where, in November 2002, a flank eruption subsequently occurred. These observations suggest that pre-eruptive volcanic activity may have enhanced photosynthesis along the future eruptive fissure. If a direct relation between NDVI and future volcanic eruptions could be established, it would provide a straightforward and low-cost method for early detection of upcoming eruptions. However, it is unclear if, or to what extent, the observed enhancement of NDVI can be attributed to volcanic activity prior to the subsequent eruption. We conse…
Natural Genetic Variation of Freezing Tolerance in Arabidopsis
2006
Abstract Low temperature is a primary determinant of plant growth and survival. Using accessions of Arabidopsis (Arabidopsis thaliana) originating from Scandinavia to the Cape Verde Islands, we show that freezing tolerance of natural accessions correlates with habitat winter temperatures, identifying low temperature as an important selective pressure for Arabidopsis. Combined metabolite and transcript profiling show that during cold exposure, global changes of transcripts, but not of metabolites, correlate with the ability of Arabidopsis to cold acclimate. There are, however, metabolites and transcripts, including several transcription factors, that correlate with freezing tolerance, indica…
Garibaldi popolare. Politiche novecentesche dell’icona risorgimentale
2019
«Hero of the People». Political uses of Garibaldi’s image in the XXth century · Garibaldi epitomizes Italian Risorgimento also on an iconographical level. With particular reference to Sicily in the XXth century, the article aims at analyzing first some aspects of an often thaumaturgic Garibaldi’s figure within subaltern culture, chiefly through handcratfs, political tattoos, painted scenes pertaining to traditional puppet theatre as well as to ornate carts. All these contexts show a dense circulation between ‘high’ and ‘low’ culture. The elections for the regional parliament in 1947 are characterized by the massive use of Garibaldi in the frame of Communist propaganda; we try to shed light …
Remote sensing of sun-induced fluorescence to improve modeling of diurnal courses of gross primary production (GPP)
2010
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…
An updated checklist and biogeography of the Sardinian large branchiopods, with a focus on Spinicaudata (Crustacea, Branchiopoda)
2021
Author(s): Marrone, Federico; Alfonso, Giuseppe; Cottarelli, Vezio; Botta, Marco Massimo; Koepp, Christian; Stoch, Fabio | Abstract: The large branchiopod fauna of Sardinia is reviewed based both on literature and newly collected data. Based on the available evidence, 13 taxa are present on the island (8 Anostraca, 2 Notostraca, and 3 Spinicaudata). Among them, the finding of the spinicaudatan Leptestheria dahalacensis is new for Sardinia, while the spinicaudatans Cyzicus bucheti and Eulimnadia sp. were overlooked in the most recent synopses on the fauna of the island due to misidentifications. Conversely, Cyzicus tetracerus and Limnadia lenticularis, previously erroneously reported based o…
Intercomparison and quality assessment of MERIS, MODIS and SEVIRI FAPAR products over the Iberian Peninsula
2013
Abstract The fraction of absorbed photosynthetically active radiation (FAPAR) is a key variable in productivity and carbon cycle models. The variety of available FAPAR satellite products from different space agencies leads to the necessity of assessing the existing differences between them before using into models. Discrepancies of four FAPAR products derived from MODIS, SEVIRI and MERIS (TOAVEG and MGVI algorithms), covering the Iberian Peninsula from July 2006 to June 2007 are here analyzed. The assessment is based on an intercomparison involving the spatial and temporal consistency between products and a statistical analysis across land cover types. In general, significant differences ar…
The Effect of Phosphinothricin (Glufosinate) on Photosynthesis II. The Causes of Inhibition of Photosynthesis
1987
It was shown in the previous study that phosphinothricin (glufosinate) causes an accumulation of ammonia and inhibition of photosynthesis. The extent to which there is a connection between these two processes is now investigated in the present study. First of all. the role of NH3 per se in the impairment of photosynthesis was to be clarified. For this purpose, the inhibition of photosynthesis was investigated in relation to exogenously applied ammonia in chloroplasts, protoplasts and entire leaves. The comparison with the experimental results in leaves in which the ammonia was formed endogenously (by action of phosphinothricin) shows that the ammonia toxicity at least cannot be solely resp…
Effect of phosphinothricin (glufosinate) on photosynthesis and photorespiration of C3 and C 4 plants.
1990
Phosphinothricin (glufosinate), an irreversible inhibitor of glutamine synthetase, causes an inhibition of photosynthesis in C3 (Sinapis alba) and C4 (Zea mays) plants under atmospheric conditions (400 ppm CO2, 21% O2). This photosynthesis inhibition is proceeding slower in C4 leaves. Under non-photorespiratory conditions (1000 ppm CO2, 2% O2) there is no inhibition of photosynthesis. The inhibition of glutamine synthetase by phosphinothricin results in an accumulation of NH4 (+). The NH4 (+)-accumulation is lower in C4 plants than in C3 plants. The inhibition of glutamine synthetase through phosphinothricin in mustard leaves results in a decrease in glutamine, glutamate, aspartate, asparag…
Oxidative DNA base damage induced by singlet oxygen and photosensitization: recognition by repair endonucleases and mutagenicity.
2000
We have analyzed the recognition by various repair endonucleases of DNA base modifications induced by three oxidants, viz. [4-(tert-butyldioxycarbonyl)benzyl]triethylammonium chloride (BCBT), a photochemical source of tert-butoxyl radicals, disodium salt of 1,4-etheno-2,3-benzodioxin-1,4-dipropanoic acid (NDPO(2)), a chemical source of singlet oxygen, and riboflavin, a type-I photosensitizer. The base modifications induced by BCBT, which were previously shown to be mostly 7,8-dihydro-8-oxoguanine (8-oxoGua) residues, were recognized by Fpg and Ogg1 proteins, but not by endonuclease IIII, Ntg1 and Ntg2 proteins. In the case of singlet oxygen induced damage, 8-oxoGua accounted for only 35% of…
Fanconi's anaemia cells have normal steady-state levels and repair of oxidative DNA base modifications sensitive to Fpg protein
1998
Abstract Cells from Fanconi's anaemia (FA) patients are abnormally sensitive to oxygen. However, a distinct genetic defect in either the cellular defence against reactive oxygen species (ROS) or in their metabolic generation has not been identified to date. Recently, the gene for the human 8-hydroxyguanine (8-oxoG) glycosylase, which removes this oxidative base modification from the genome, has been localized on chromosome 3p25, i.e., in the same region as the FA complementation group D (FAD) gene. We therefore studied the removal of photosensitization-induced 8-oxoG residues from the DNA of FA cells, using Fpg protein, the bacterial 8-oxoG glycosylase, to quantify the lesions by alkaline e…