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31.
This paper discusses the possibility of including the culturing of microalgae within a conventional wastewater treatment sequence by growing them on the blackwater (BW) from biosolid dewatering to produce biomass to feed the anaerobic digester. Two photobioreactors were used: a 12 L plexiglas column for indoor, lab-scale tests and a 85 L plexiglas column for outdoor culturing. Microalgae (Chlorella sp. and Scenedesmus sp.) could easily grow on the tested blackwater. The average specific growth rate in indoor and outdoor batch tests was satisfactory, ranging between 0.14 and 0.16 day?1. During a continuous test performed under outdoor conditions from May to November, in which the off-gas from the combined heat and power unit was used as the CO2 source, an average biomass production of 50 mgTSS L?1 day?1 was obtained. However, statistical analyses confirmed that microalgal growth was affected by environmental conditions (temperature and season) and that it was negatively correlated with the occurrence of nitrification. Finally, the biochemical methane potential of the algal biomass was slightly higher than that from waste sludge (208 mLCH4 gVS?1 vs. 190 mLCH4 gVS?1).  相似文献   
32.
The volatile oil of the bark of Cinnamomum zeylanicum was extracted by means of supercritical CO2 fluid extraction in different conditions of pressure and temperature. Its chemical composition was characterized by GC-MS analysis. Nineteen compounds, which in the supercritical extract represented >95% of the oil, were identified. (E)-Cinnamaldehyde (77.1%), (E)-beta-caryophyllene (6.0%), alpha-terpineol (4.4%), and eugenol (3.0%) were found to be the major constituents. The SFE oil of cinnamon was screened for its biological activity about the formation of melanin in vitro. The extract showed antityrosinase activity and was able to reduce the formation of insoluble flakes of melanin from tyrosine. The oil also delayed the browning effect in apple homogenate. (E)-Cinnamaldehyde and eugenol were found to be mainly responsible of this inhibition effect.  相似文献   
33.
Investigation of PCDDs, PCDFs, PCBs, Al, As, Pb, Ba, Co, Cu, Cr, Fe, Mn, Cd, Ag, Sn, Zn, and Hg contents in 60 samples of cold-pressed essential oils produced in Calabria and Sicily in 2003-2005 was carried out. PCDDs, PCDFs, and PCBs were analyzed by HRGC-HRMS techniques using U.S. EPA 1613/94 and U.S. EPA 1668/A (1999) analytical methods. Mineral components were determined through GFAAS techniques; Hg content was determined by FI-M/H-AAS. The results of this study showed that essential oil contamination was due to a widespread pollution, typical background of rural areas, with relatively higher concentrations of PCDDs compared to PCDFs and little presence of PeCDF. Congeners OCDD, HpCDF, and OCDF were found at high concentrations. Regarding mineral components, mean values of Cr, Fe, and Ni were in agreement with data reported in the literature. Concentrations of As and Pb were below the maximum limits accepted by the current legislation. Finally, none of the samples analyzed were contaminated with Hg.  相似文献   
34.
PCR products obtained by selective amplification of transgenic DNA derived from food samples containing Roundup Ready soybean or Bt-176 maize have been analyzed by anion-exchange HPLC. Peptide nucleic acids (PNAs), oligonucleotide analogues known to bind to complementary single-stranded DNA with high affinity and specificity, have been used as specific probes in order to assess the identity of the peaks observed. Two different protocols were adopted in order to obtain single-stranded DNA: amplification with an excess of one primer or digestion of one DNA strand. The single-stranded DNA was mixed with the PNA probe, and the presence of a specific sequence was revealed through detection of the corresponding PNA:DNA peak with significantly different retention time. Advantages and limits of this approach are discussed. The method was tested with reference materials and subsequently applied to commercial samples.  相似文献   
35.
This paper focuses on the analysis of the slope and catchment erosion dynamics in a typical Mediterranean context and its sensitivity to recent climatic and socio‐economic changes. The main objective of the present study is to test the reliability of digital photogrammetric analysis to evaluate the time and space evolution of erosion processes mainly triggered by surface running waters and landslides for about the last 60 years. The selected test area is the Landola catchment, a minor tributary of the Upper Orcia River Valley (Southern Tuscany). The Upper Orcia valley is a key site for the comprehension of denudation processes typically acting in Mediterranean badland areas thanks to the following: (i) the availability of long‐lasting erosion monitoring datasets (20 years' long direct measurements at erosion ‘hot spots’); (ii) its representativeness as a sub‐humid Mediterranean badland area; and (iii) the rapidity of development of erosion processes, which makes it suitable as an open‐air laboratory for the study of badland dynamics. The outputs of this work highlight that the application of high‐resolution digital photogrammetric methodologies can represent a powerful and low‐cost tool to evaluate rates and spatial–temporal distribution of denudation processes, as confirmed by the validation through field point monitoring in areas close to the study area. The results obtained for the study area confirm that high erosion rates are a persistent environmental problem for the Upper Orcia Valley, which is not solved up to now, despite various land conservation interventions. The performed multi‐temporal analysis shows a slight decrease in the average water erosion rate during the last 60 years and a parallel increase in the frequency of mass wasting events. These variations are most likely related to a complex interplay between land use changes that have affected the study area during the studied period, revealing a very delicate equilibrium between farming activities and erosion processes. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   
36.
Environmental stress as salinity can negatively affect the physiology of tomato plants. Conditions leading to a reduction of transpiration can contribute to greater tolerance to salinity. Use of kaolin-based particle film technology (PFT) may be an effective tool to control stomatal conductance and transpiration rate, thus mitigating the detrimental effect of salinity. The present three-year study has investigated the effects of kaolin application on leaf gas exchange, leaf water potential, leaf and canopy temperature of field-grown tomato, irrigated with brackish water by drip method, in southern Italy. Treatments were: (1) three salinity levels of irrigation water (electrical conductivity of water = 0.5, 5 and 10 dS m?1); (2) tomato plants treated or not with kaolin; and (3) two cultivars in each year. The increase in salinity caused the reduction of leaf water potential, stomatal conductance, net photosynthesis and transpiration rate, and the increase of leaf and canopy temperature. Kaolin has resulted in an improvement of leaf water potential, and the reduction in gas exchange variables in low-salinity conditions. Under high salinity, kaolin was effective in limiting the reductions in net photosynthesis and reducing leaf and canopy temperature. These latter variables were slightly affected by kaolin, in different ways in respect to the saline treatments; while in non-saline conditions were 0.2–0.5°C higher in the kaolin-treated plants, the situation was reversed in more saline treatment. The variation of leaf and canopy temperature shows that kaolin influences the thermal balance mainly for the dual effect of reflection of the incident radiation and partial occlusion of the stomata. Kaolin mitigated detrimental effects of salinity also on yield, contributing to the improvement of income for the farmers. The use of kaolin-based PFT may be an effective tool to alleviate salinity stress in tomato production under arid and semi-arid conditions.  相似文献   
37.
The usual media and procedures were followed to measure the concentration of fecal streptococci (MPN on Azide Dextrose and Ethyl Violet Azide broths, membrane filtration on m-Enterococcus, KF and Pfizer Selective Enterococcus agars and according to the mE procedure) in samples collected along two different marine areas. The results were evaluated on the basis of three parameters: total concentrations, number of enterococci-like colonies (namely colonies gram positive, catalase negative, coccus shaped) and rate of strictly named fecal streptococci. From the results it appears that the various media and procedures employed gave different yields and their capacity to measure fecal streptococci varies according to the origin of samples. The accompanying bacterial flora may play an important role on the selectivity of each technique to measure the fecal streptococci.  相似文献   
38.
An analysis of the polar extracts from sweet potato Ipomoea batatas (Convolvulaceae) led to the isolation of seven unknown aminoacyl sugars. On the basis of 1D, 2D NMR, and mass spectrometry data, the structures of the compounds were elucidated as: beta-D-fructofuranosyl-(2 --> 1)-alpha-D-[2-O-valyl]-glucopyranoside (1), beta-D-fructofuranosyl-(2 --> 1)-alpha-D-[2-O-tyrosyl]-glucopyranoside (2), beta-D-fructofuranosyl-(2 --> 1)-alpha-D-[2-O-threonyl]-glucopyranoside (3), beta-D-fructofuranosyl-(2 --> 1)-alpha-D-[2-O-hystidyl]-glucopyranoside (4), 2-beta-D-fructofuranosyl-(2 --> 1)-alpha-D-[2-O-alanyl]-glucopyranoside (5), beta-D-fructofuranosyl-(2 --> 1)-alpha-D-[2-O-tryptophanyl]-glucopyranoside (6), and beta-D-fructofuranosyl-(2 --> 1)-alpha-D-[2-O-glycyl]-glucopyranoside (7).  相似文献   
39.
Soil fauna in the extreme conditions of Antarctica consists of a few microinvertebrate species patchily distributed at different spatial scales. Populations of the prostigmatic mite Stereotydeus belli and the collembolan Gressittacantha terranova from northern Victoria Land (Antarctica) were used as models to study the effect of soil properties on microarthropod distributions. In agreement with the general assumption that the development and distribution of life in these ecosystems is mainly controlled by abiotic factors, we found that the probability of occurrence of S. belli depends on soil moisture and texture and on the sampling period (which affects the general availability of water); surprisingly, none of the analysed variables were significantly related to the G. terranova distribution. Based on our results and literature data, we propose a theoretical model that introduces biotic interactions among the major factors driving the local distribution of collembolans in Antarctic terrestrial ecosystems.  相似文献   
40.
This report describes an unusual case of uterine stump pyometra in a cat whose main clinical sign at presentation was abdominal straining. At the time of ovariohysterectomy, the surgeon reported that the uterine body had a purulent content. Nearly a month after the surgery the cat showed abdominal straining. The enlarged uterine stump, filled with purulent fluid, had caused a compression of the rectum and secondary intestinal sub-occlusion. Surgical revision consisted of draining the purulent content of the remnant of the uterine body and ablating as much of it as possible; checking of the ovarian pedicles revealed the presence of a small fragment of whitish tissue on the right side, which was shown to contain, by means of histological observation and immunohistochemical staining, ovarian tissue. Four months after surgical revision the queen did not show any pathological signs and 1 year later she is still in good health.  相似文献   
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