193 research outputs found

    Impacts of climate and land use changes on the hydrological and erosion processes of two contrasting Mediterranean catchments

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    The impacts of climate and land use changes on streamflow and sediment export were evaluated for a humid (São Lourenço) and a dry (Guadalupe) Mediterranean catchment, using the SWAT model. SWAT was able to produce viable streamflow and sediment export simulations for both catchments, which provided a baseline for investigating climate and land use changes under the A1B and B1 emission scenarios for 2071–2100. Compared to the baseline scenario (1971–2000), climate change scenarios showed a decrease in annual rainfall for both catchments (humid: − 12%; dry: − 8%), together with strong increases in rainfall during winter. Land use changes were derived from a socio-economic storyline in which traditional agriculture is replaced by more profitable land uses (i.e. corn and commercial forestry at the humid site; sunflower at the dry site). Climate change projections showed a decrease in streamflow for both catchments, whereas sediment export decreased only for the São Lourenço catchment. Land use changes resulted in an increase in streamflow, but the erosive response differed between catchments. The combination of climate and land use change scenarios led to a reduction in streamflow for both catchments, suggesting a domain of the climatic response. As for sediments, contrasting results were observed for the humid (A1B: − 29%; B1: − 22%) and dry catchment (A1B: + 222%; B1: + 5%), which is mainly due to differences in the present-day and forecasted vegetation types. The results highlight the importance of climate-induced land-use change impacts, which could be similar to or more severe than the direct impacts of climate change alone

    Genomes of Helicobacter pylori prophages

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    Nearly 20% of the Helicobacter pylori genomes carry prophages genes. Recently we were able to clearly differentiate four populations of prophages according to geographical origin of host strain. Interestingly we were able to discriminate between Northern Europe and Southern Europe using a phage sequence typing based on 2 prophage genes of H. pylori (integrase and holin) but present in only a minority of strains.info:eu-repo/semantics/publishedVersio

    Soil biochemistry and microbial activity in vineyards under conventional and organic management at Northeast Brazil.

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    The SĂŁo Francisco Submedium Valley is located at the Brazilian semiarid region and is an important center for irrigated fruit growing. This region is responsible for 97% of the national exportation of table grapes, including seedless grapes. Based on the fact that orgThe SĂŁo Francisco Submedium Valley is located at the Brazilian semiarid region and is an important center for irrigated fruit growing. This region is responsible for 97% of the national exportation of table grapes, including seedless grapes. Based on the fact that organic fertilization can improve soil quality, we compared the effects of conventional and organic soil management on microbial activity and mycorrhization of seedless grape crops. We measured glomerospores number, most probable number (MPN) of propagules, richness of arbuscular mycorrhizal fungi (AMF) species, AMF root colonization, EE-BRSP production, carbon microbial biomass (C-MB), microbial respiration, fluorescein diacetate hydrolytic activity (FDA) and metabolic coefficient (qCO2). The organic management led to an increase in all variables with the exception of EE-BRSP and qCO2. Mycorrhizal colonization increased from 4.7% in conventional crops to 15.9% in organic crops. Spore number ranged from 4.1 to 12.4 per 50 g-1 soil in both management systems. The most probable number of AMF propagules increased from 79 cm-3 soil in the conventional system to 110 cm-3 soil in the organic system. Microbial carbon, CO2 emission, and FDA activity were increased by 100 to 200% in the organic crop. Thirteen species of AMF were identified, the majority in the organic cultivation system. Acaulospora excavata, Entrophospora infrequens, Glomus sp.3 and Scutellospora sp. were found only in the organically managed crop. S. gregaria was found only in the conventional crop. Organically managed vineyards increased mycorrhization and general soil microbial activity

    Investigating empirical and theoretical calculations for intensity ratios of L-Shell X-ray transitions in atoms with 39 ≀ Z ≀ 94

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    The significance of theoretical, experimental, and analytical methods in calculating the intensity ratios of L-shell transitions for diverse elements lies in their widespread applications across various domains, including physical chemistry and medical research. In the present paper, empirical values for intensity ratios were computed through polynomial interpolations using experimental databases within the scope of atomic number 39 ≀ Z ≀ 92 for I L ÎČ I L α and I L Îł I L α , and extending to the range of 39 ≀ Z ≀ 94 for I Ll I L α . Additionally, new theoretical calculations were conducted using the Multiconfiguration Dirac–Fock Method for specific elements. The obtained results were compared with standard theoretical, experimental, and empirical values, showing a reasonable agreement with them

    Databases of L-shell X-ray intensity ratios for various elements after photon excitation

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    In this study, a comprehensive dataset of X-ray emission intensity ratios has been compiled, including I L ÎČ / I L α , I L Îł / I L α , I Ll / I L α , I L Îł / I L ÎČ , I Ll / I L Îł , I Ll / I L ÎČ , I L Îł 5 / I L α , I L Îł 44 â€Č / I L α , I L η / I L α , and I L Îł 1 / I L α , extracted from literature spanning the years 1971 to 2023, and encompassing 83 research papers. Over this timeframe, a total of 2600 values were collected, comprising some 678 values for I L ÎČ / I L α , 696 values for I L Îł / I L α , 617 values for I Ll / I L α , along with 132, 132, 89, 60, 70, 71, and 55 data points for I L Îł / I L ÎČ , I Ll / I L Îł , I Ll / I L ÎČ , I L Îł 5 / I L α , I L Îł 44 â€Č / I L α , I L η / I L α , and I L Îł 1 / I L α , respectively. The reported values are presented with precision up to three to four decimal places, accompanied by their associated uncertainties. Additionally, the tables include calculated weighted averages ( I L i / I L j ) W , uncertainty values ( Δ I S D , Δ E S D ), combined standard deviations ( z I S D , z E S D ), and average z-scores ( z ÂŻ I S D , z ÂŻ E S D ) for these intensity ratios. The data encompasses elements ranging from 39Y to 94Pu when excited by photon bombardment. The assessment of how these experimental data values are distributed according to atomic number indicates extensive coverage across most elements. However, a few isolated instances were identified where either no data or fewer than two data values were available

    Vacancy transfer probability parameters : Database and a new empirical value for elements in the atomic number range 16 ≀ Z ≀ 92

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    In the present work, we offer a collection of documented values for vacancy transfer probabilities ( η X Y , X = K , L i ; Y = L , M , N , L i , M j , N p , O p ; i = 1 , 2 , 3 ; j = 1 , 2 , 3 , 4 , 5 ; p = 1 , 4 , 5 ) sourced from published technical literature spanning 1993 to 2023 for elements in the atomic range 16 ≀ Z ≀ 92 . We found 1200 experimental vacancy transfer probability values from 68 scientific papers, during the specified period. These have been compiled and summarized in tables, encompassing various parameters and elements. This data is also comprehensively analysed, including tables that display weighted average vacancy transfer probability ( η X Y ) W values along with the combined standard deviation and the average z-score. We also recommend a new collection of empirical values for the atomic parameters η KL ( T ) , η KL 2 ( R ) , η KL 3 ( R ) , a n d η KM ( R ) of vacancy transfer probabilities. This compilation offers an overview of the present state of atomic data for vacancy transfer probabilities. It is a valuable resource to guide future experimental and theoretical studies in this area
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