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31.
The effect of methionine dietary deficiency on food intake, weight gain, liver and kidney weight, feed conversion rate, protein efficiency ratio, maltase and leucineaminopeptidase (LAPase) activities of the intestinal mucosa as well as renal LAPase activity was studied. Three groups of female Wistar rats, weighing between 40-60 g, were fed for 25 days on either Diet A (casein supplemented with 0.6% DL-methionine), Diet B (amino acid mixture simulating casein also supplemented with 0.6% methionine) or Diet C (amino acid mixture with 0.67% methionine deficiency with respect to Diet A). The results show no significant differences in either growth or enzymatic activity between the rats fed on Diet A and those on Diet B. The animals fed on Diet C show an increase in intestinal (P less than 0.01, vs Diet B) and renal (P less than 0.005, vs Diet A) LAPase activity, although intestinal maltase activity remained unchanged. Food intake, weight gain, organ weight and nutritional parameters obtained in rats fed on Diet C showed no statistically significant changes, with the exception of kidney weight which decreased (P less than 0.005) when compared to those fed on Diet B.  相似文献   
32.
The various land management and planning policies that have been developed for the Tierra de Campos district of northwestern Spain over the past century have had major effects on wetland ecosystems of this area. To assist conservation planners in the future management of these habitats, this study outlines the changes that have occurred in these environments using data for the years 1900, 1956, 1984 and 2007. Multiple logistic regression models allowed the accurate projection of locations of wetlands that need to be restored or regenerated. These models were developed using a combination of 19 explanatory variables including: data related to historic lakelets, variations in the surfaces of wetlands, soil physicochemical and weather data, and socioeconomic and spatial planning data, as depicted by thematic mapping. The landscape used for projecting the wetlands in the study area was classified into five categories based on the probability of the presence of lakelets: very low, low, medium, high and very high. These generated maps show that the spatial extent of the wetlands of the Tierra de Campos district was 2.78 % in 1900–1933 and decreased to 0.65 % in 2007–2008. Accordingly, a dramatic decrease in the spatial extent covered by these ecosystems is observed over the twentieth century according to these maps; consequently these results highlight the effects of positive (protective) or negative (desiccative) policies implemented in the area.  相似文献   
33.
A key issue to be taken into account in any mining operation or premises is workers’ health and safety. Noise has negative repercussions on workers’ health, which is why regular inspections of noise levels are necessary to ensure that noise is less than legally permitted limits. In our study we statistically analyzed functional data with a view to determining noise levels in an aggregates plant. Data were captured by a sound level meter that indicated equivalent sound pressure levels and peaks and the octave bands for a specific range of frequencies. Unlike the methods habitually used to construct noise maps (which only permit one of these parameters to be determined for each point), the methods applied in our research enable the noise level to be calculated at each point for the entire spectrum of frequencies picked up by a sound level meter. For each point we obtain, rather than a single value, a noise curve reflecting the entire range of frequencies detected by the sound level meter. This enables us to better understand the effects of noise and to determine its origin.  相似文献   
34.
Fermentation bioprocesses typically involve two liquid phases (i.e. water and organic compounds) and one gas phase (air), together with suspended solids (i.e. biomass), which are the components to be dispersed. Characterization of multiphase dispersions is required as it determines mass transfer efficiency and bioreactor homogeneity. It is also needed for the appropriate design of contacting equipment, helping in establishing optimum operational conditions. This work describes the development of image analysis based techniques with advantages (in terms of data acquisition and processing), for the characterization of oil drops and bubble diameters in complex simulated fermentation broths. The system consists of fully digital acquisition of in situ images obtained from the inside of a mixing tank using a CCD camera synchronized with a stroboscopic light source, which are processed with a versatile commercial software. To improve the automation of particle recognition and counting, the Hough transform (HT) was used, so bubbles and oil drops were automatically detected and the processing time was reduced by 55% without losing accuracy with respect to a fully manual analysis. The system has been used for the detailed characterization of a number of operational conditions, including oil content, biomass morphology, presence of surfactants (such as proteins) and viscosity of the aqueous phase.  相似文献   
35.
A novel method to obtain crystals of pure, anhydrous salt, using aqueous two-phase systems was studied. A concentrated salt solution is mixed with polyethylene glycol (PEG), upon which three phases are formed: salt crystals, a PEG-rich liquid and a salt-rich liquid. After removal of the solid salt, a two-phase system is obtained. Both liquid phases are recycled, allowing the design of a continuous process, which could be exploited industrially. The phase diagram of the system water–Na2SO4–PEG 3350 at 28°C was used. Several process alternatives are proposed and their economic potential is discussed. The process steps needed to produce sodium sulphate crystals include mixing, crystallisation, settling and, optionally, evaporation of water. The yield of sodium sulphate increases dramatically if an evaporation step is used.  相似文献   
36.
Giovanni Forzieri  Loïc P. Dutrieux  Agata Elia  Bernd Eckhardt  Giovanni Caudullo  Flor Álvarez Taboada  Alessandro Andriolo  Flavius Bălăcenoiu  Ana Bastos  Andrei Buzatu  Fernando Castedo Dorado  Lumír Dobrovolný  Mihai-Leonard Duduman  Angel Fernandez-Carrillo  Rocío Hernández-Clemente  Alberto Hornero  Săvulescu Ionuț  María J. Lombardero  Samuli Junttila  Petr Lukeš  Leonardo Marianelli  Hugo Mas  Marek Mlčoušek  Francesco Mugnai  Constantin Nețoiu  Christo Nikolov  Nicolai Olenici  Per-Ola Olsson  Francesco Paoli  Marius Paraschiv  Zdeněk Patočka  Eduardo Pérez-Laorga  Jose Luis Quero  Marius Rüetschi  Sophie Stroheker  Davide Nardi  Ján Ferenčík  Andrea Battisti  Henrik Hartmann  Constantin Nistor  Alessandro Cescatti  Pieter S. A. Beck 《Global Change Biology》2023,29(21):6040-6065
Insect and disease outbreaks in forests are biotic disturbances that can profoundly alter ecosystem dynamics. In many parts of the world, these disturbance regimes are intensifying as the climate changes and shifts the distribution of species and biomes. As a result, key forest ecosystem services, such as carbon sequestration, regulation of water flows, wood production, protection of soils, and the conservation of biodiversity, could be increasingly compromised. Despite the relevance of these detrimental effects, there are currently no spatially detailed databases that record insect and disease disturbances on forests at the pan-European scale. Here, we present the new Database of European Forest Insect and Disease Disturbances (DEFID2). It comprises over 650,000 harmonized georeferenced records, mapped as polygons or points, of insects and disease disturbances that occurred between 1963 and 2021 in European forests. The records currently span eight different countries and were acquired through diverse methods (e.g., ground surveys, remote sensing techniques). The records in DEFID2 are described by a set of qualitative attributes, including severity and patterns of damage symptoms, agents, host tree species, climate-driven trigger factors, silvicultural practices, and eventual sanitary interventions. They are further complemented with a satellite-based quantitative characterization of the affected forest areas based on Landsat Normalized Burn Ratio time series, and damage metrics derived from them using the LandTrendr spectral–temporal segmentation algorithm (including onset, duration, magnitude, and rate of the disturbance), and possible interactions with windthrow and wildfire events. The DEFID2 database is a novel resource for many large-scale applications dealing with biotic disturbances. It offers a unique contribution to design networks of experiments, improve our understanding of ecological processes underlying biotic forest disturbances, monitor their dynamics, and enhance their representation in land-climate models. Further data sharing is encouraged to extend and improve the DEFID2 database continuously. The database is freely available at https://jeodpp.jrc.ec.europa.eu/ftp/jrc-opendata/FOREST/DISTURBANCES/DEFID2/ .  相似文献   
37.
Efficient ophthalmic therapy requires the development of strategies that can provide sufficiently high drug levels in the ocular structures for a prolonged time. This work focuses on the suitability of poly-(cyclo)dextrins as carriers able to solubilize the carbonic anhydrase inhibitor (CAI) ethoxzolamide (ETOX), which is so far used for oral treatment of glaucoma. Topical ocular treatment should notably enhance the efficiency/safety profile of the drug. Natural α-, β- and γ-cyclodextrins and a maltodextrin were separately polymerized using citric acid as cross-linker agent under mild conditions. The resultant hydrophilic polymers exhibited larger capability to solubilize ETOX than the pristine (cyclo)dextrins. Moreover, they provided sustained drug diffusion in artificial lachrymal fluid. Interestingly the poly-(cyclo)dextrins solutions facilitate the loading of remarkably high doses of ETOX in poly(2-hydroxyethyl methacrylate)-based contact lenses. Exploiting ionic interactions between functional groups in the contact lenses and remnant free carboxylic acids in the citric acid linkers of poly-(cyclo)dextrins led to the retention of the drug-loaded poly-(cyclo)dextrins and, in turn, to sustained release for several weeks.  相似文献   
38.
Two groups of rats were fed on diets with protein from a marine specie holothuria (Holothuria forskali) or casein (for the control group) during 16 days with the aim of assessing the nutritional value of the holothuria protein. Several serum lipid levels were also determined. The results of the nutritive parameters indicate that except for True Digestibility (which did not differ significantly between the two groups) all other indicators were significantly lower for the holothuria fed group. HDL-cholesterol level was significantly higher in the holothuria fed group, while triglyceride level was lower.  相似文献   
39.
The dietary effects of two high protein diets from two species of sea urchin (Paracentrotus lividus and Echinus esculentus) as compared to a reference protein such as casein on serum lipid levels and on intestinal disaccharidases and alkaline phosphatase were studied. After 23 days, the containing the two sea urchins as diets compared to casein decreased the cholesterol level and significantly increased the HDL-cholesterol in serum. The consumption of Echinus esculentus meal produced a significant decrease in lactase activity. The intestinal alkaline phosphatase activity increased not significantly in animals fed on the sea urchin meal.  相似文献   
40.
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