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61.

Purpose

In soils from serpentinitic areas the natural background of Ni and Cr is so high that the assessment of contamination by comparing metal concentrations with some fixed thresholds may give unreliable results. We therefore sought a quantitative relation between serpentines and Ni and Cr concentrations in uncontaminated soils, evaluated if the approach may help in establishing a baseline, and discussed if additional anthropogenic inputs of Ni and Cr can be realistically individuated in these areas.

Materials and methods

We analysed the total, acid-extractable and exchangeable concentrations of Ni and the total and acid-extractable concentrations of Cr in 66 soil horizons, belonging to 19 poorly developed and uncontaminated Alpine soils. The soils had different amounts of serpentines, depending on the abundance of these minerals in the parent material. We calculated an index of abundance of serpentines in the clay fraction by XRD and related total metal contents to the mineralogical index. We then tested the regressions on potentially contaminated soils, developed on the alluvial plain of the same watershed.

Results and discussion

We found extremely high total concentrations of Ni (up to 1,887 mg kg–1) and Cr (up to 2,218 mg kg–1) in the uncontaminated soils, but only a small proportion was extractable. Total Ni and Cr contents were significantly related to serpentine abundance (r 2?=?0.86 and 0.74, respectively). The regressions indicated that even small amounts of serpentines induced metal contents above 200 mg kg–1, and the 95% confidence limits were 75 and 111 mg kg–1 of Ni and Cr, respectively. When the regressions were tested on the potentially contaminated soils, a good estimate was obtained for Cr, while the Ni concentration was overestimated, probably because of some leaching of this element.

Conclusions

The concentrations of Ni and Cr that can be expected in soils because of the presence of small amounts of serpentines are comparable to the amounts accumulated in the soil because of diffuse contamination and potentially contaminated soils had metal concentrations falling in the range expected from the presence of natural sources. Only in the case of very severe contamination events, the identification of anthropogenic sources adding to the natural background would be feasible.  相似文献   
62.
Live BW and BCS data were collected from 2,775 breeding rabbits (644 males and 2,131 females) of 34 genetic types and sorted according to their specialization (maternal, paternal, and others). Data were gathered on 66 visits to 43 commercial farms in Spain between 2009 and 2011. Mean BW was 4.72 kg (range of 2.87 to 8.13 kg, with a median BW of 4.60 kg) and mean BCS was 4.6 (range of 1.0 to 9.0, with a median BCS of 5.0). females had heavier (P < 0.05) BW than males and paternal lines of rabbits had greater (P < 0.05) BW than maternal lines and other breeds/lines not selected for meat production. Between 69.3% and 75.4% of the rabbits were deemed healthy by a veterinarian and, as expected, healthy rabbits were heavier (P < 0.05) than sick rabbits diagnosed with rhinitis, mastitis, sore hocks, and several other diseases. Among purebred, maternal lines of rabbits, Hyplus GD24, UPV A, and UPV V were heavier (P < 0.05) than hyplus GD14 and Hyla HL-D lines, and line UPV R had the greatest (P < 0.05) BW among the purebred, paternal lines. Additionally, A×H, A×V, PS19, and P×A crossbreds had greater (P < 0.05) BW than HE-C×D, HL-C×D, H×V, LP×V, and V×P crossbreds among the maternal lines, whereas HE-SL were the heaviest (P < 0.05) crossbred paternal line of rabbits. Additionally, females received greater (P < 0.05) BCS than males and BCS were greater (P < 0.05) in healthy than sick rabbits. Moreover, maternal lines had smaller (P < 0.05) BCS than either paternal lines or other lines/breeds not selected for meat production. Results also indicated a moderate relationship between BCS and BW (r = 0.32), with a 1-point change in BCS equivalent to an ~ 245-g change in BW. results from this study can be used as baseline figures for breeding rabbits in spain and are essential factors in several decisions concerning housing, feeding, reproduction, health, and welfare of breeding rabbits.  相似文献   
63.
The protein and mineral composition of different varieties of three different lupin species (Lupinus albus, Lupinus angustifolius, and Lupinus luteus) and the effect of alpha-galactoside removal by means of a hydroalcoholic extraction process on such composition were studied in relationship to nutrient distribution among the different anatomical parts of the seed (embryo, cotyledon, and seed coat). The extent of processing-derived protein insolubilization was assessed by both chemical and electrophoretic techniques and related to the amount of nitrogen soluble in H(2)O, NaCl, ethanol, NaOH, and sodium dodecyl sulfate/beta-mercaptoethanol (SDS/BME). The alpha-galactoside extraction process caused a significant increase in the amount of total and insoluble nitrogen and decreased the amount of soluble protein nitrogen, without affecting the content of soluble nonprotein nitrogen. alpha-Galactoside extraction was not effective at decreasing the levels of Mn present in lupins, and processing caused an increase in the content of this mineral in all of the species studied with the exception of L. albus var. multolupa. In general, the effect of processing on mineral content varied with the different lupin species, and mineral losses were lower in L. luteus.  相似文献   
64.
Cherimoya (Annona cherimola (Mill.)) is a subtropical fruit tree, which is cultivated in a good range of subtropical regions. In most of these areas the crop relies on hand pollination. However, following this practice, erratic fruit set is often produced, which could be related to problems in pollen handling. Indeed, very little is known of the time that the pollen remains viable and on which is the best stage to collect the anthers or pollen from the flower. The aim of this work is to evaluate pollen germinability prior and after anther dehiscence and also how the age of pollen affects pollen vigor, understood as speed of germination. Pollen samples at different times following anther dehiscence were germinated in vitro and in vivo. Pollen up to 90 min following dehiscence performed as well as freshly dehisced pollen. However, the pollen taken 120 min following dehiscence, showed a clear reduction in vigor and germinated much slower in vivo. To overcome this short pollen germinability, pollen was taken from anthers 30 and 5 h prior to natural anther dehiscence and compared with pollen taken at anther dehiscence and 20 h later. However, a reduction in germination rate was obtained in pollen taken prior to anther dehiscence. The narrow stage at which pollen can be collected together to its ephemeral germinability explains erratic results obtained following hand pollination in this crop and these results provide the clues for an adequate pollen handling.  相似文献   
65.
New resistance sources coming from Lycopersicon peruvianum, especially those introgressed in UPV 32 line, are studied. UPV 32 resistance is controlled by a single gene. Resistance and dominance levels of this gene are conditioned by thrips transmission and isolate aggressiveness. A partial overcoming of resistance occurs due to the incomplete penetrance of the gene. Incomplete dominance of resistance also happens, which suggests gene dosage dependence. UPV 32 gene segregates independently of both Sw-5 gene and UPV 1 resistance gene, also coming from Lycopersicon peruvianum. It is proposed to name Sw-6 this new locus from UPV 32. Sw-5 gene and UPV 1 resistance gene show higher resistance than Sw-6. Heterozygotes for UPV 1 resistance gene were more resistant than heterozygotes for Sw-5. The lower dependence of UPV 1 resistance gene on the gene dosage effect makes it very useful for the development of commercial hybrids.  相似文献   
66.
67.
An experiment was conducted to determine whether spray-dried porcine plasma containing 2.47 x 10(5) dna copies of porcine circovirus type 2 (pcv-2) could infect weanling pigs when fed to them. Five specific pathogen-free (spf) weanling pigs were fed ad libitum for 45 days a control diet and six pigs were fed a test diet containing 8 kg sdpp per 100 kg feed. The two groups were housed in separate biosecurity level-3 rooms. None of the pigs in either group developed any clinical signs or became pcv-2 viraemic or seroconverted.  相似文献   
68.
Breast cancer is the leading cause of death among women worldwide. Over the years, oxidative stress has been linked to the onset and progression of cancer. In addition to the classical histological classification, breast carcinomas are classified into phenotypes according to hormone receptors (estrogen receptor—RE—/progesterone receptor—PR) and growth factor receptor (human epidermal growth factor receptor—HER2) expression. Luminal tumors (ER/PR-positive/HER2-negative) are present in older patients with a better outcome. However, patients with HER2-positive or triple-negative breast cancer (TNBC) (ER/PR/HER2-negative) subtypes still represent highly aggressive behavior, metastasis, poor prognosis, and drug resistance. Therefore, new alternative therapies have become an urgent clinical need. In recent years, anticancer agents based on natural products have been receiving huge interest. In particular, carotenoids are natural compounds present in fruits and vegetables, but algae, bacteria, and archaea also produce them. The antioxidant properties of carotenoids have been studied during the last years due to their potential in preventing and treating multiple diseases, including cancer. Although the effect of carotenoids on breast cancer during in vitro and in vivo studies is promising, clinical trials are still inconclusive. The haloarchaeal carotenoid bacterioruberin holds great promise to the future of biomedicine due to its particular structure, and antioxidant activity. However, much work remains to be performed to draw firm conclusions. This review summarizes the current knowledge on pre-clinical and clinical analysis on the use of carotenoids as chemopreventive and chemotherapeutic agents in breast cancer, highlighting the most recent results regarding the use of bacterioruberin from haloarchaea.  相似文献   
69.
70.
The fatty acid (FA) composition of nine potentially important forage species was determined (n = 330): red drum (Sciaenops ocellatus), spot (Leiostomus xanthurus), spotted seatrout (Cynoscion nebulosus), striped mullet (Mugil cephalus), pinfish (Lagodon rhomboides), Atlantic croaker (Micropogonias undulatus), star drum (Stellifer lanceolatus), striped anchovy (Anchoa hepsetus), and brief squid (Lolliguncula brevis). Samples were collected from estuarine and nearshore coastal waters around Charleston, South Carolina, USA, from March 2002–February 2003. Twenty-nine of 125 identified FAs were included in multivariate analyses of FA profiles. Despite existing intraspecific variation, the PRIMER routine analysis of similarity (ANOSIM) indicated each species was distinct, and discriminant function analysis correctly classified 99.5% of the training data set samples (n = 221) and 98.2% of the validation samples (n = 109). Most species could be characterized by distinctive levels of a suite of FAs. Our results indicated FA profiles can be used to reliably distinguish even closely related forage species in this southeastern US estuarine ecosystem. The information gained from this study not only provides insight into the biochemical composition of these important species but also provides fundamental information to support studies on the feeding ecology of local higher-level predators. The U.S. Government’s right to retain a non-exclusive, royalty-free license in and to any copyright is acknowledged.  相似文献   
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