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51.
Carotenoids and chlorophyll-derived compounds in grapes and Port wines were investigated by HPLC-DAD and HPLC-DAD-MS (ESP+) analysis. A total of 13 carotenoid and chlorophyll-derived compounds are formally reported in grapes, 3 are identified for the first time, pheophytins a and b and (13Z)-beta-carotene, and 3 others remain unknown. In Port wines 19 compounds with carotenoid or chlorophyll-like structures are present, 8 still unidentified. The young wines showed higher total carotenoid content and chlorophyll-like compounds compared to aged Ports, with lutein and beta-carotene as major carotenoids. Among samples analyzed of monovarietal Vitis vinifera L. cultivar wines produced with the five most important Douro varieties, Tinta Roriz contained the highest levels of carotenoids and Touriga Franca the lowest. The forced-aging study indicated that lutein was more sensitive to temperature than beta-carotene. Additionally, aged wines showed higher ratios of beta-carotene/lutein concentrations compared to new Ports. Rates of degradation of chlorophyll derivative compounds were higher than those for carotene and lutein.  相似文献   
52.
Many tropical fruits are rich in anthocyanins, though limited information is available about the characterization and quantification of these anthocyanins. The identification and quantification of anthocyanin pigments in four tropical fruits were determined by HPLC-MS/MS. Fruits studied included acerola (Malphigia emarginata), jussara (Euterpe edulis), jambol?o (Syzygium cumini), and guajiru (Chrysobalanus icaco). All four fruits were found to contain anthocyanin pigments. Anthocyanidin backbones included cyanidin, delphinidin, peonidin, pelargonidin, petunidin, and malvidin. Guajiru contained several acylated forms, while acerola, jussara, and jambol?o contained only nonacylated glycosides. These results demonstrate that these tropical fruits are rich in anthocyanins and that the anthocyanins are widely ranging in anthocyanidin backbone, glycosylation, and acylation.  相似文献   
53.
The feeding habits of soil mesofauna have been a mystery for decades, and depending on the methods used, different degrees of feeding specialisation have been observed. A new way to study the almost unknown feeding habits of soil mesofauna e.g. oribatid mites is to use PCR-based techniques. When applying PCR on these small organisms, the low amount of ingested DNA can cause problems. Even more important is to certify that the amplified DNA does not originate from body-surface contamination. The aim of this study was to analyse if washing of the body surface combined with PCR can be a successful approach when identifying the food ingested by fungivorous mites. The method was developed in a laboratory system where we used the oribatid mite Archegozetes longisetosus as a model organism due to its relatively short life cycle and ease of laboratory culturing. The results demonstrated that surface contamination is a serious problem. Both washing and dissection was needed to remove surface contamination on such small organisms. To get a reliable result the samples also had to contain at least five pooled guts, but preferably ten. This is the first step towards a successful use of PCR-based methods to study natural feeding habits of species most likely contaminated on the body surface. When modified for field conditions, the results obtained by this method have a high potential to answer many questions about the animals feeding habits, and their functional role in the soil.  相似文献   
54.
55.

Purpose

Wastes from a former Portuguese steel plant were deposited between 1961 and 2001 on the riverbank of a tributary of the Tagus River creating a landfill connected to the river, posing a potential contamination risk to the Tagus estuary ecosystem. This study aims to assess the transfer of chemical elements from contaminated sediments to the estuarine water from cycles of sediment leaching so as to evaluate the ecotoxicity of the leachates, and to analyze the solid phases crystallized from those leachates.

Materials and methods

Landfill sediment and estuarine water samples were collected during low tide. Sediment samples were analyzed for pH, electric conductivity (EC), Corg, NPK, and iron oxides. Leaching assays (four replicates) were done using estuarine water (200 cm3/replicate) and 1.5 kg of sediment per reactor. Each reactor was submitted to four leaching processes (0, 28, 49, and 77 days). The sediment was kept moist between leaching processes. Sediment (total (acid digestion) and available fraction (diluted organic acid extraction-Rhizo)) elemental concentrations were determined by inductively coupled plasma–instrumental neutron activation analysis (ICP/INAA). Leachates, and estuarine and sediment pore waters were analyzed for metals/metalloids by ICP/mass spectrometry (MS) and carbonates/sulfate/chloride by standard methodologies. Ecotoxicity assays were performed in leachates and estuarine and pore waters using Artemia franciscana and Brachionus plicatillis. Aliquots of the leachates were evaporated to complete dryness (23–25 °C) and crystals analyzed by X-ray powder diffraction (XRD).

Results and discussion

Sediment with pH?=?8 and high EC and Corg was contaminated with As, Cd, Cr, Cu, Pb, and Zn. The element concentrations in the available fraction of the sediment were low compared to the sediment total concentrations (<1 % for Rhizo extraction). The concentrations of potentially hazardous elements in the estuarine water were relatively low, except for Cd. Concentrations of hazardous elements in the leachates were very low. Calcium, K, Mg, Na, and chloride concentrations were high but did not vary significantly among the four leaching experiments. Total concentrations of carbonate were much higher in leachates than in estuarine water. Both estuarine water and leachates showed negligible toxicity. Crystals identified in the solids obtained from the leachates by evaporation were halite, anhydrite, epsomite, dolomite, and polyhalite.

Conclusions

The sediment showed the capacity to retain the majority of the potentially hazardous chemical elements. Remobilization of chemical elements from sediment by leaching was essentially negligible. The variation of total concentrations of Ca, carbonate, and sulfate in leachates indicates that the sediment contained reactive sulfides. Due to its composition, the sediment seems to be a dynamic system of pollution control, which should not be disturbed.
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56.
A complete study was made of 20 Spanish herbaria and of the literature concerning the regional flora of Spain in order to define the geographical limits of the different genera of the subtribe Hordeineae found in Spain. Accordingly, several expeditions were undertaken to the greater part of the Spanish mainland and its islands in order to collect samples of wild populations of the genera Hordeum L., Taeniatherum Nevski and Hordelymus Jessen. This paper, which contains information garnered from both collection activities and the study of herbaria, describes the distribution and ecological characteristics of the habitats where populations of H. bulbosum, H. secalinum, H. murinum subsp. murinum, H. murinum subsp. leporinum, H. marinum subsp. marinum, H. marinum subsp. gussoneanum, Taeniatherum caput-medusae and Hordelymus europeus grow.The bioclimatic and geographical characteristics of the populations of the different genera and species from which samples were taken during collect ing expeditions are also described.  相似文献   
57.
Considering the very high socio economic value of cork oak (Quercus suber L.) in Mediterranean areas, a better knowledge of local genetic resources is necessary in order to reach a good balance between the conservation issues and the need of an efficient cork production network. In such frame, local germplasm of Q. suber from the main cork production areas of Sardinia was analysed for DNA and isozyme polymorphisms and for cork quality in relation to some environmental parameters. A total number of 24 sample stands of cork oak were selected, representing typical vegetation, sylvicultural and cork quality features within the eight identified cork growing areas in Sardinia. Considerable variation was found between cork oak stands of the different areas. Results of the principal component analysis performed on the cork quality data and environmental characters of the eight areas, showed that the first three components explain 72.2% of the variation. The major characters involved in this differentiation were cork quality characters such as dimensional recover, moisture and Mg content of the cork and also elevation of stands m a.s.l. for the first component. The second component appears to be determined by some climatic parameters (average annual temperature and average of the minimum temperatures of coldest month) and by the Fe and Zn in the cork. For the third component, major characters involved in differentiation are average annual rainfall, bark thickness and Ca content in the cork.  相似文献   
58.
Loquat [Eriobotrya japonica (Thunb.) Lindl.] is a minor fruit-tree species which is grown commercially in the Mediterranean region. Given the current increase in loquat cultivation, there is a need to define basic crop-management procedures in order to obtain high yields and optimal fruit quality. The aim of this work was to develop a routine for loquat farmers to follow, in order to know the nutritional status of trees in order to establish a rational fertilization regime, and to correct nutrient deficiencies as soon as possible. This paper reports three experiments aimed at establishing: 1) leaf type, 2) time of leaf sampling and 3) the standard leaf nutrient levels as a function of maximum yield. Results indicate that the summer flush leaves could be the most representative of nutritional status. Thus, the most appropriate time to sample leaves for analysis is in summer (beginning of August to the end of September), taking mature 3–4 month old leaves.  相似文献   
59.

Precision agriculture (PA) has a huge potential for growth in sub-Saharan Africa (SSA), but it faces a number of social-economic and technological challenges. This study sought to map existing PA research and application in SSA countries following the methodology for systematic mapping in environmental sciences. After screening for relevance, the initial about 7715 articles was reduced to 128. Results show that most of the studies were conducted in countries with socio-economic and technological advancement, mainly South Africa followed by Nigeria and Kenya. The studies were conducted at various scales ranging from field to country level with field scale studies being the most common. Most studies were conducted in relatively small farms typical of most farmlands in SSA. Studies done in relatively large farms are fewer, and such farms would likely belong to a few organisations and individuals with high economic capacity. Many of these studies have been conducted by researchers from outside SSA and a combination of researchers from within and outside SSA. However, based on authorship of the articles, it appears that most of the studies conducted in SSA on precision agriculture have either involved or depended on non-African researchers. It is concluded that there have been significant strides towards use of precision agriculture in SSA. However, with about 21 countries having no research done, there exists greater potential for precision agriculture in the region. Besides, there is need for more research to investigate the low usage of precision agriculture for livestock management.

  相似文献   
60.
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