411 research outputs found

    Study on the isolation and characterization of rhizobia strains as biofertilizer tools for growth improvement of four grain legumes in Ngaoundéré-Cameroon

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    Increasing the yield and economical efficiency of grain legumes in the Guinea-Savannah zone of Cameroon is a high researcher priority to assist growers in the rural areas. We report here a two-years study inthe production process of fertilizer containing rhizobia for a sustainable production of grain legumes in the region. To address the issue, nodulation and rhizobia strains characterization were assessed at Dang and Wakwa, two soils different in trapping rhizobia partners for groundnut, bambara groundnut, cowpea and soybean. This was a prerequisite step in the determination of the most efficient rhizobia strains for biofertilizer production. Results indicate that all the four grain legumes differently formed nodules in their roots system in the two experimental soils. Cowpea and soybean demonstrated a highly significant (p ≀ 0.001) potential in fixing atmospheric nitrogen through their nodules than groundnut and bambara groundnut. The dry weight of nodules in groundnut and bambara groundnut was significantly lower (0.0001 < p ≀ 0.038) than that of cowpea and soybean in the two soils. When rhizobia were isolated from root nodules of plant species, the number of isolates ranged from 2 to 4 per grain legumes. All the isolates were convex in elevation, smooth/humid on the surface, with regular edges, except one groundnut colony from wakwa soil. The colonies were either whitish for soybean, whitish/yellowish for cowpea, groundnut and bambara groundnut. The rhizobia biofertilizer produced for each grain legumes were stored in the refrigerator for field tests. This is a step forward for further molecular characterization of isolates to enable production of elite inoculum in the region.© 2009 International Formulae Group. All rights reserved.Key words: Grain legumes, nodulation, Rhizobium characterization, Rhizobium biofertilizer

    Reactions of medicinal gold(III) compounds with proteins and peptides explored by electrospray ionization mass spectrometry and complementary biophysical methods

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    Electrospray ionization mass spectrometry (ESI MS) is a powerful investigative tool to analyze the reactions of metallodrugs with proteins and peptides and characterize the resulting adducts. Here, we have applied this type of approach to four experimental anticancer gold(III) compounds for which extensive biological and mechanistic data had previously been gathered, namely, Auoxo6, Au2phen, AuL12, and Aubipyc. These gold(III) compounds were reacted with two representative proteins, i.e., human serum albumin (HSA) and human carbonic anhydrase I (hCA I), and with the C-terminal dodecapeptide of thioredoxin reductase. ESI MS analysis allowed us to elucidate the nature of the resulting metal–protein adducts from which the main features of the occurring metallodrug–protein reactions can be inferred. In selected cases, MS data were integrated and supported by independent 1HNMR and UV–Vis absorption measurements to gain an overall description of the occurring processes. From data analysis, it emerges that most of the investigated gold(III) complexes, endowed with an appreciable oxidizing character, undergo quite facile reduction to gold(I); the resulting gold(I) species tightly associate with the above proteins/peptides with a remarkable selectivity for free cysteine residues. In contrast, in the case of the less-oxidizing Aubipyc complex, the gold(III) oxidation state is conserved, and a gold(III) fragment still containing the original ligand is found to be associated with the target proteins. It is notable that the C-terminal dodecapeptide of thioredoxin reductase containing the characteristic –Gly–Cys–Sec–Gly metal-binding motif is able in all cases to trigger gold(III)-to-gold(I) reduction. Our investigation allowed us to identify in detail the nature of the gold fragments that ultimately bind the protein targets and determine the exact binding stoichiometry; some insight on the reaction kinetics was also gained. Notably, a few clear correlations could be established between the structure of the metal complexes and the nature of the resulting protein adducts. The mechanistic implications of these findings are analyzed and thoroughly discussed. Overall, the present results set the stage to better understand the real target biomolecules of these gold compounds and elucidate at the atomic level their interaction modes with proteins and peptides

    A two-step parallel plate chamber with a resistive germanium anode and a two dimensional readout for the detection of minimum ionizing particles

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    Abstract A parallel plate avalanche chamber specially suited for the high resolution detection of minimum ionizing particles (m.i.p.) is presented. The anode is made of a thin germanium layer with a sheet resistivity > 1 M Ω/p[ while the cathode is made of a nickel mesh having 600 line pairs/in. A chess board of pads placed behind the anode plane is used to obtain the positional information. A 100% detection efficiency, a 40 ns (fwhm) time resolution and a spatial resolution better than 140 Όm (fwhm) for both coordinates have been measured

    Greenhouse gas emissions in the agricultural phase of wine production in the Maremma rural district (Tuscany, Italy).

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    In recent years, there has been an increasing interest from retailers, industries and environmental associations in estimating the life cycle of greenhouse gases emitted in the atmosphere from everyday products and services, also known as carbon footprint (CF). Life cycle assessment (LCA) is the most common methodology used to evaluate the environmental impact of a product. This approach was largely used in many industrial sectors and was also recently applied to quantify the environmental impact of the agri-food chain. Within agri-food products, wine is one of the most analysed, both for its importance in economic production and in the world distribution market. The present study is a part of the Carbon Label Project carried out in the wine production chain in the Maremma rural district (Tuscany, Italy). The project assessed the greenhouse gas (GHG) emissions from wine production for labelling purposes. Here, we evaluated the environmental performances of four high quality wines for carbon labelling. The international standards ISO 14040, ISO 14044, and the Product Category Rules (PCR) Wine from Fresh Grapes (except sparkling wine) and Grape Must for the Environmental Product Declaration (EPD) certification, specifically for Climate Declaration, were used in order to carry out our analyses. The functional unit (FU) used here was one 0.75 L bottle of wine. The system boundaries were set from the vineyard planting to the distribution and waste disposal. The global warming potential (GWP) of four investigated wines was found to lie between 0.6 and 1.3 kg CO2-eq./bottle, showing a value comparable with literature. With all the four wines analysed, the agricultural phase covered, on average, 22% of the total GWP/bottle, while the main impact was in the production of the glass bottle. The results showed that the vineyard-planting phase has a significant impact on the wine CF, thus it has to be considered in the life cycle, while in literature it is frequently omitted. On the contrary, the pre-production phase did not present a relevant impact. The use of nitrogen fertilisers, the grapes’ yield and N2O emissions were the parameters that mostly affected the carbon footprint in the agricultural phase, as underlined by the sensitivity analysis

    Plasduino: an inexpensive, general purpose data acquisition framework for educational experiments

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    Based on the Arduino development platform, Plasduino is an open-source data acquisition framework specifically designed for educational physics experiments. The source code, schematics and documentation are in the public domain under a GPL license and the system, streamlined for low cost and ease of use, can be replicated on the scale of a typical didactic lab with minimal effort. We describe the basic architecture of the system and illustrate its potential with some real-life examples.Comment: 11 pages, 10 figures, presented at the XCIX conference of the Societ\`a Italiana di Fisic

    A novel type of parallel plate chamber with resistive germanium anode and a two-dimensional readout

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    Abstract A parallel plate counter with a resistive anode and a two-dimensional readout is presented. The anode is made of a thin germanium layer with a sheet resistivity â©Ÿ 1 M ω /square and the cathode is made of aluminized mylar 5 ÎŒm thick. The anode is transparent to the fast impulse due to the collection of the multiplication electrons. A chessboard of "pads" placed behind the anode plane is used to obtain the positional information. The detector and the readout system are physically and logically separated. An overall spatial resolution of 70 ÎŒm (rms) for both coordinates has been measured

    Reading a GEM with a VLSI pixel ASIC used as a direct charge collecting anode

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    In MicroPattern Gas Detectors (MPGD) when the pixel size is below 100 micron and the number of pixels is large (above 1000) it is virtually impossible to use the conventional PCB read-out approach to bring the signal charge from the individual pixel to the external electronics chain. For this reason a custom CMOS array of 2101 active pixels with 80 micron pitch, directly used as the charge collecting anode of a GEM amplifying structure, has been developed and built. Each charge collecting pad, hexagonally shaped, realized using the top metal layer of a deep submicron VLSI technology is individually connected to a full electronics chain (pre-amplifier, shaping-amplifier, sample and hold, multiplexer) which is built immediately below it by using the remaining five active layers. The GEM and the drift electrode window are assembled directly over the chip so the ASIC itself becomes the pixelized anode of a MicroPattern Gas Detector. With this approach, for the first time, gas detectors have reached the level of integration and resolution typical of solid state pixel detectors. Results from the first tests of this new read-out concept are presented. An Astronomical X-Ray Polarimetry application is also discussed.Comment: 11 pages, 14 figures, presented at the Xth Vienna Conference on Instrumentation (Vienna, February 16-21 2004). For a higher resolution paper contact [email protected]

    Application of Vis/Nir spectroscopy to establish peach ripening as affected by rootstock

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    The objective of this paper was to monitor peach ripeness of “Chimarrita” and “Maciel” cultivars, grafted on different rootstocks, using the pulp firmness parameter, as an indicator of harvest time through equipment based on Vis/Nir spectroscopy. The orchard was installed in 2005, has a "V" conduction system with spacing of 5.0 x 1.5 m, and the cultivars are grafted on seven rootstocks: “Capdeboscq”, “Flordaguard”, “Nemaguard”, “Okinawa”, “Tsukuba”, “Umezeiro” and “Viamão”. After harvesting, the fruits were evaluated by the NIR CASE spectrophotometer, establishing categories of pulp firmness, between 40N and 60N for fruits consumed in a long term and <40N for immediate consumption. The analyzed rootstocks alter the peach ripeness of the “Chimarrita” and “Maciel” cultivars. The “Umezeiro” rootstock anticipates harvest for the “Chimarrita” cultivar. The “Nemaguard”/ “Maciel” combination provides fruits with a superior harvest period than the other ones evaluated. The Vis/Nir Spectroscopy is a useful tool to monitor the harvest of “Chimarrita” and “Maciel” cultivars

    Nutritional and nutraceutical properties of raw and traditionally obtained flour from chestnut fruit grown in Tuscany

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    The study of local chestnut and traditional techniques related to their use and consumption are considered of primary importance to promote their nutritional/nutraceutical values. Fruit of four local chestnut cultivars (‘Carpinese’, ‘Pontecosi’, ‘Capannaccia’ and ‘Morona’) from Garfagnana (Italy) were analysed under nutritional and antioxidant aspects and compared with their flour obtained through a traditional thermal-drying process. Raw fruit contained significative amounts of P, K and Mg (~ 149, 1960 and 50&nbsp;mg 100&nbsp;g−1 dry weight, respectively) and they were characterised by a good moisture content (~ 49%) and starch (~ 50&nbsp;g 100&nbsp;g−1 dw). The traditional thermal-drying processes affected the carbohydrate content of dried chestnut showing a higher sucrose and lower starch content as compared to raw fruits. Traditional thermal-drying processes negatively influenced also total phenol content (TP) and total antioxidant activity: flours from all cultivars contained lower amounts of TP than raw fruit except for ‘Morona’ in which these compounds remained unchanged. This study provides new useful information about the evaluation of nutritional and nutraceutical characteristics of Tuscany local chestnuts and the effects of a traditional thermal-drying processing method, helping consumers and producers to valorise these “forest products”
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