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31.
This work investigates the degradation of Reactive Gray BF-2R dye (a blend of reactive yellow 145, reactive orange 122 and reactive black 5 dyes) using UV/H2O2, Fenton, and photo-Fenton-advanced oxidative processes, with artificial sunlight and UV-C radiations. The photo-Fenton process employing UV-C radiation was the most efficient under the conditions studied. The ideal conditions for the degradation of the dye, determined using a factorial design 23 and a study of the concentration of hydrogen peroxide ([H2O2]), were [H2O2] equal to 40 mg L?1, iron concentration [Fe] of 1 mg L?1, and pH between 3 and 4. The Chan and Chu non-linear kinetic model predicted the kinetic data with a degradation of over 98% for color and 68% for aromatics after 60 min. The behavior of the chemical oxygen demand fitted the first-order kinetic model well, with a degradation of 64% after 60 min. The Multilayer Perceptron 7-11-2 artificial neural network model enabled to model the degradation process of the aromatics and accurately predict the experimental data. Toxicity tests indicated that the post-treatment samples were non-toxic for Escherichia coli bacteria, and Portulaca grandiflora and Basil sabory seeds. However, they inhibited the growth of Lactuca sativa seeds and Salmonella enteritidis bacteria. The photo-Fenton process with UV-C radiation degraded the dye studied efficiently and the degradation percentages were, on average, 7% and 5% higher for color than those observed when employing the Fenton and UV/H2O2 processes, respectively. With the aromatic, however, they were 84% and 62% higher, thus justifying the use of this process.  相似文献   
32.
In previous studies, it has been demonstrated that, similar to general practitioners, veterinarians find it difficult to discuss overweight in dogs. This study aimed to provide insight in the barriers and motivators for veterinarians to discuss overweight in dogs and to compare the results with findings from human medicine. Sub-hypotheses were postulated based on existing literature to investigate if lack of time, fear of offending clients, or lack of skills were potential barriers, and if feeling responsible and feeling compassion were potential motivators for veterinarians to discuss overweight in dogs. To this end, an online survey (n = 59) was conducted. Furthermore, 15 small animal clinicians working in general practice were interviewed by semi-structured face-to-face interviews. Results from the online survey indicated that veterinarians find it sometimes difficult to discuss overweight in dogs. Veterinarians who responded to the online survey did not experience strong barriers but did make use of motivators (e.g. feeling responsible and feeling compassion) when discussing overweight in dogs. Interestingly, results from the semi-structured face-to-face interviews showed that the responding veterinarians did experience strong barriers, as well as motivators, when discussing overweight in dogs with their clients. The most prominent barrier was customer dissatisfaction, whereas lack of time and lack of skills were also experienced. The most prominent motivator was feeling responsible for animal health and preventive veterinary medicine. These findings were strikingly similar to previous research on discussing childhood overweight by general practitioners. To improve treatment and prevention of overweight in dogs, veterinarians need more communication skills and should be more aware of the motivators that drive their self-motivation. Improving awareness on overweight and its comorbidities should be a One Health issue.  相似文献   
33.
A commercial microencapsulated diet was used as a total or partial replacement of live prey for feeding larvae of winter flounder Pseudopleuronectes americanus (Walbaum), a potential alternative finfish species for coldwater marine aquaculture. Growth performance (morphometric measurements and biochemical composition) and nutritional condition (RNA/DNA ratios) of larvae fed live prey (Brachionus plicatilis Müller), a microencapsulated diet or a mixed diet of live prey and microcapsules were compared. Newly hatched larvae were unable to digest microencapsulated diet; live prey at initial feeding was required for their survival and growth. Larvae offered a mixed diet showed slower growth than larvae fed exclusively with live prey. However, at the onset of stomach differentiation, RNA/DNA ratios (indicators of protein synthesis potential) of the larvae fed both diets became similar. We suggest that, at that stage (size 5.5–6.3 mm), enzymatic activity had developed enough to allow digestion of inert food. As the RNA/DNA ratio is a good indicator of nutritional condition, it appears to be an interesting tool for the assessment of diet adequacy in marine larval feeding technology.  相似文献   
34.
Fractionation of the polyphenols constituting a food grade lingonberry extract (Vaccinium vitis-idaea) highlighted a composition more complex than described until now in the berry. Procyanidins B1, B2, and A2 were identified by UPLC/ESI-MS(2) along with the presence of other flavanol oligomers. Processing induced the release of large amounts of aglycones for ferulic acid, p-coumaric acid, and quercetin. The described anthocyanic composition of lingonberry was completed with hexoside derivatives of peonidin, petunidin, malvidin, and delphinidin. Besides confirmation of in vitro antioxidant activity, in vivo study was performed on rats fed a diet inducing oxidative stress. Supplementation with lingonberry extract significantly decreased the total oxidant status and favorably affected antioxidant defense enzymes in red blood cells and liver. A drop in the serum reduced glutathione level was also prevented, and uric acid was maintained at low level, confirming the antioxidant activity of the extract (5% proanthocyanidins) from a dosage of 23 mg/kg of body weight.  相似文献   
35.
Antioxidant activities of polyphenolic compounds extracted (PPEs) from ripe fruits of oil palms are investigated by studying their in vitro effects on human low-density lipoprotein (LDL) oxidation. Four oil palm species ( Elaeis guineensis ) are issued from the National Centre of Agronomic Research of Co?te d'Ivoire, of which two are parental varieties (HP1 and HP2), while the other two are crossing varieties (HP3 and HP4). The main identified compounds were rutin (HP3 and HP4) and caffeic and chlorogenic (5-caffeoyl quinic) acids (HP1, HP3, and HP4). The highest total phenolic content was found for HP4, while it was significantly lower for HP2. Antioxidative effects were monitored by Cu(2+)- or 2,2'-azobis(2-amidinopropane) hydrochloride (AAPH)-induced generation of conjugated dienes (lag time and oxidation rate). The highest PPE specific antioxidant activity (SAA) values were obtained with crossing varieties (HP3 and HP4) in the copper-oxidation assay. In the AAPH-oxidation assay, SAA values were comparable for all four varieties. PPEs were effective at preventing LDL-vitamin E depletion in vitro. They could exert direct beneficial antioxidant effects on vitamin E and other antioxidants contained in food and beverages in vivo, within the gastrointestinal (GI) tract. These data could also be of particular importance for a healthier nutrition or the management of chronic diseases by a polyphenol-rich diet.  相似文献   
36.
The understanding of the molecular biology of Polymyxa betae, the protist vector of Beet necrotic yellow vein virus, remains limited because of the obligate nature of this root endoparasite and the limited data on the genome of Beta vulgaris, its most common host plant. The aim of this work was to assess the infection of P. betae in Arabidopsis thaliana in order to learn more about the P. betae genome and its interaction with the host. The susceptibility of a set of ecotypes of various origins to a monosporosorus and aviruliferous isolate of P. betae was analyzed in a series of bioassays conducted under controlled conditions. P. betae was detected in roots of A. thaliana using light microscopy and PCR. The infection severity was relatively low in this species compared with B. vulgaris, but the different stages of the life cycle were present. The phenotype of P. betae in A. thaliana root cells differed from the phenotype in B. vulgaris: the spore-forming phase was more prevalent in comparison with the sporangial phase, and the sporosori contained a lower number of spores. The compatible interaction between P. betae and A. thaliana obtained after the inoculation of zoospores and optimal conditions for the development of P. betae provide a new model system that can be used to improve the knowledge on the P. betae genome and on the mechanisms of the spore-forming phase of P. betae.  相似文献   
37.
Human-induced changes in the hydrology of the western United States   总被引:7,自引:0,他引:7  
Observations have shown that the hydrological cycle of the western United States changed significantly over the last half of the 20th century. We present a regional, multivariable climate change detection and attribution study, using a high-resolution hydrologic model forced by global climate models, focusing on the changes that have already affected this primarily arid region with a large and growing population. The results show that up to 60% of the climate-related trends of river flow, winter air temperature, and snow pack between 1950 and 1999 are human-induced. These results are robust to perturbation of study variates and methods. They portend, in conjunction with previous work, a coming crisis in water supply for the western United States.  相似文献   
38.
This analysis identifies and attempts to resolve the paradox of combining plant hyperaccumulators and arbuscular mycorrhizal fungi (AMF) for the purpose of post-industrial bioremediation due to the divergence of their respective ecological and evolutionary stress-tolerance behaviors. The identification of a ‘dilemma of resource allocation’ associated with plant resources consumed in intrinsic (e.g. metabolic) vs. extrinsic (e.g. symbiotic) stress-tolerance mechanisms could provide a suitable evolutionary reasoning for the apparent dichotomy existing between the hyperaccumulators and AMF–plant life-history strategies. Ultimately, it is considered that any efforts toward integrating such biotechnology innovations into bioremediation strategies (e.g. ‘mycorrhizal–metal-hyperaccumulators’) should first explicitly consider their inherent environmental and (or) evolutionary contexts to avoid misleading and possibly even unproductive outcomes prior to incorporating these attributes as potential technological solutions.  相似文献   
39.

Context

The landscape heterogeneity hypothesis states that increased heterogeneity in agricultural landscapes will promote biodiversity. However, this hypothesis does not detail which components of landscape heterogeneity (compositional or configurational) most affect biodiversity and how these compare to the effects of surrounding agricultural land-use.

Objectives

Our objectives were to: (1) assess the influence of the components of structural landscape heterogeneity on taxonomic diversity; and (2) compare the effects of landscape heterogeneity to those of different types of agricultural land-use in the same landscape across different taxonomic groups.

Methods

We identified a priori independent gradients of compositional and configurational landscape heterogeneity within an agricultural mosaic of north-eastern Swaziland. We tested how bird, dung beetle, ant and meso-carnivore richness and diversity responded to compositional and configurational heterogeneity and agricultural land-use across five different spatial scales.

Results

Compositional heterogeneity best explained species richness in each taxonomic group. Bird and ant richness were both positively correlated with compositional heterogeneity, whilst dung beetle richness was negatively correlated. Commercial agriculture positively influenced bird species richness and ant diversity, but had a negative influence on dung beetle richness. There was no effect of either component of heterogeneity on the combined taxonomic diversity or richness at any spatial scale.

Conclusions

Our results suggest that increasing landscape compositional heterogeneity and limiting the negative effects of intensive commercial agriculture will foster diversity across a greater number of taxonomic groups in agricultural mosaics. This will require the implementation of different strategies across landscapes to balance the contrasting influences of compositional heterogeneity and land-use. Strategies that couple large patches of core habitat across broader scales with landscape structural heterogeneity at finer scales could best benefit biodiversity.
  相似文献   
40.
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