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41.
The processes of release and retention of phosphorus (P) in soils of a tidal floodplain were studied at Combu Island (Belém/Brazil). Three parcels of 220m2 were chosen: low floodplain (LF), intermediate floodplain (MF) and high floodplain (HF). Two cores to 0.4 m depth were collected in each parcel, one week after the highest and lowest tides of the year. Organic phosphorus (P—OM) concentrations ranged from 0.02 ± 0.01 to 0.07 ± 0.02 mg/g, the highest concentrations were found in the HF parcel. On the other hand the HF parcel had the lowest concentrations of total inorganic phosphorus (TIP): 0.10 ± 0.03 to 0.11 ± 0.33 mg/g. The speciation of inorganic P suggested that P—Fe/Al is the main chemically bound P in soil (0.05 ± 0.01 to 0.20 — 0.04 mg/g). The tidal inundation of the floodplain appears to influence these chemical reactions involving phosphate retention and release. 相似文献
42.
Levy Carvalho Gomes Richard Philip Brinn Jaydione Luiz Marcon Lucelle Araújo Dantas Franmir Rodrigues Brandão Janessa Sampaio de Abreu Paulo Evandro Mendes Lemos Dawn Michelle McComb & Bernardo Baldisserotto 《Aquaculture Research》2009,40(2):157-165
The objective of this experiment was to test the probiotic Efinol® L during transportation of cardinal tetra, Paracheirodon axelrodi (Schultz). For the transportation, fish were distributed in 18 plastic tanks, of which nine contained the Efinol® L (10 mg L−1 ; probiotic treatment) and the remaining had no probiotic (control treatment). Transport lasted 24 h and three different boxes of each treatment were sampled at 3, 12 and 24 h. Up to the 12-h sampling period, no significant difference in the survival was observed; on the other hand, survival was higher at the end of the transport (24 h) in the probiotic treatment. No significant difference was found in dissolved oxygen and temperature between treatments. Conductivity, pH and alkalinity increased along the transport, but without a difference between treatments. Ammonia increased in all treatments, although it was significantly lower in the probiotic group at 24 h. Cortisol levels were significantly higher in all transported fish when compared with the basal values. At 24 h, cortisol levels in control fish were significantly higher than those in the probiotic treatment. With the observed results, we are able to conclude that the probiotic Efinol® L is efficient during cardinal transport, lowering the mortality and helping maintain water quality possibly by lowering metabolic wastes. 相似文献
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44.
Alana Batista dos Santos Mara Lúcia Albuquerque Pereira Herymá Giovane de Oliveira Silva Gleidson Giordano Pinto de Carvalho Taiala Cristina de Jesus Pereira Leandro Sampaio Oliveira Ribeiro José Augusto Gomes Azevêdo Maria das Graças Conceição Parada Costa Silva Larisse Borges Sousa Leandro Borges Sousa Daiane de Oliveira Alencar 《Tropical animal health and production》2016,48(3):509-515
45.
Esterina Fazio Pietro Medica Cristina Cravana Adriana Ferlazzo 《Journal of Veterinary Behavior: Clinical Applications and Research》2013,8(4):231-237
Cortisol may be useful as a marker in predicting how an animal will respond to stressful stimuli, thus providing information on animal's temperament. To quantify the level of transport stress and the effect of temperament on the adrenocortical response, the change in circulating cortisol levels was evaluated in 84 healthy experienced thoroughbred and crossbred stallions, mean age 11.4 ± 4.5 years old, after road transport in a commercial trailer (6 horses per load, stocking density: 2 m2/horse), over mean distances of 210 ± 11.8 km for about 3 hours. Several experienced caretakers were asked to complete 2 questionnaires, one that used a 5-point scale to subjectively evaluate temperament and another that used a 3-point scale to assess tendencies in response to ordinary care and daily management. The scores for the latter were defined as follows: a score of 1 indicated that the horse had never or rarely troubled the caretaker during management, 2 occasionally, and 3 usually. On this basis, the subjects were distinguished between calm and nervous stallions. Blood samples were taken same daytime (8.00 am), in single box, immediately before loading, then after transport and unloading. Serum cortisol concentrations were analyzed in duplicate by immunoenzymatic assay. Compared with basal levels, cortisol increases were observed in both calm (P < 0.001) and nervous (P < 0.05) stallions after transport. Repeated-measures analysis of variance showed significant effects of transport on cortisol changes (P < 0.001). Nervous subjects showed lower (P < 0.01) cortisol levels than did calm subjects after transport, and basal cortisol levels did not differ between calm and nervous subjects. No significant differences (P > 0.05) between different age, breed, and orientation were detected.The results showed that temperament could influence the adrenocortical responses of stallions after short-term transportation. The presence of the same staff for handling, loading, confinement, and unloading, the same veterinarian taking all blood samples, and the presence of cospecifics did not reduce the response to short transport stress both in calm and nervous stallions already accustomed to transport. Lower cortisol concentrations in nervous subjects might be because of failure of the adrenal cortex to respond normally to transport stress. Moreover, signs of transport stress were less pronounced in nervous stallions. 相似文献
46.
Glaydson S. dos Reis Matthew A. Adebayo Carlos H. Sampaio Eder C. Lima Pascal S. Thue Irineu A. S. de Brum Silvio L. P. Dias Flavio A. Pavan 《Water, air, and soil pollution》2017,228(1):33
Sludge-derived activated carbons (ACs) were prepared by conventional heating and microwave pyrolysis. The ACs were characterized using several analytical and functional techniques and used for removal of six phenolic compounds from aqueous solutions. The adsorbents exhibited similar features and possessed hydrophobic surfaces. The ACs were assigned mesoporous materials, with specific surface areas of up to 641 and 540 m2 g?1 for CAC-500 and MAC-980, respectively. The preliminary results indicated that phenol removal onto the ACs increased in the order: m-cresol?<?phenol?<?o-cresol?<?2-chrorophenol?<?2-nitrophenol?<?hydroquinone. Hydroquinone exhibited the highest adsorption capacity and was chosen to continue the remaining part of the experimental work—kinetic and isothermal studies. The adsorption kinetic and isotherm data were well described by the Avrami fractionary order and Redlich–Peterson models, respectively. The maximum amounts (Q max) of hydroquinone adsorbed at 25 °C were too high, reaching 1218.3 and 1202.1 mg g?1 for CAC-500 and MAC-980, respectively. The mechanism of adsorption was proposed in this work, and it was suggested that donor–acceptor complex and π–π interactions play major roles in the adsorption process. The adsorbents were also tested on simulated effluents. The two ACs displayed good efficiency for the treatment of industrial simulated effluents. 相似文献
47.
48.
Ana Cristina Borba da Cunha Sydney Sabedot Carlos Hoffmann Sampaio Claudete Gindri Ramos Alexandre Rodrigues da Silva 《Water, air, and soil pollution》2012,223(8):4723-4731
The petroleum industry activities provide potential risks to the environment because they can contaminate ecosystems with different organic compounds in the production chain. Several accidents with transport and handling of petroleum and related products occurred in urban areas with harmful effects to the quality of life and economy. In the 1990s, bioremediation and phytoremediation technologies as economically feasible alternatives to repair the environmental damage were developed. In this study, the potential of the willows Salix rubens and Salix triandra were evaluated with regard to the phytoremediation of soils contaminated with petroleum-derived hydrocarbons (total hydrocarbons and polycyclic aromatic hydrocarbons (PAHs)). The PAHs were quantified by extraction from soils and plants using dichloromethane under ultrasonication. The HPLC analysis was performed with GC/MSD equipment. The total hydrocarbons present in uncontaminated soil were quantified by the sum of animal/vegetable oils and greases and mineral oils and greases according to Standard Methods 5520 (1997). The two willows species S. rubens and S. triandra were resistant during the project development. In the contaminated soil, in which both species were planted, the total hydrocarbons concentration was reduced near 98?%. The PAHs content was remarkably reduced as well. Pyrene showed an initial concentration of 23.06???g?kg?1, decreasing in most cases to 0.1???g?kg?1 or to undetectable levels. Chrysene decreased from 126.27???g?kg?1 to undetectable levels. Benzo[k]fluoranthene and benzo[a]pyrene concentrations had also showed a decrease from 28.44 and 3.82???g?kg?1, respectively, to undetectable levels. 相似文献
49.
Fabrizio Scartezzini Pietro Fusani Nicola Aiello Carla Vender 《Genetic Resources and Crop Evolution》2012,59(3):465-471
Alpine blue-sow-thistle (Cicerbita alpina (L.) Wallr.) is a perennial herb distributed all along the entire Alpine Arc, the shoots of which are still collected in
the wild in several areas of Northern-Eastern Italy for food purposes. Our paper deals with experiments of domestication of
this species carried out in the surroundings of Trento and lasted from 2004 to 2010. The cultivation was carried out transplanting
seedlings, obtained by wild seed of a unique accession. One experimental trial (2004/2008) was carried in the location Frisanchi,
located at 1,078 m a.s.l. In this trial the theses compared 4 harvests, 1 week spaced, carried out respectively in the 2nd,
3rd and 4th year after the transplant. Of the total quantity harvested after 4 years, the most shoots (60) and the highest
dried weight per m2 (14 g) were obtained from shoots collected 2 or 3 years after being transplanted. However, comparing the shoots yielded in
the last year of the trial only (2008), the best results were obtained from 3 or 4-year-old transplants (42 shoots/m2; 8.2 g dry weight). Nevertheless there four times harvesting of shoots weakened the plants’ development and a high failure
rates was recorded. In addition to the real experimental trial another small cultivation was carried out in an higher location,
Monte Bondone at 1,500 m a.s.l., in which 5 years after the transplant (2010) only 2 harvests were carried out. In this experiment
the yield recorded was very encouraging (10.5 g m2) and also the quality of the shoots collected was good. 相似文献
50.
To date, most of the experimental and modelling research on the mobilization mechanisms of autochthonous colloidal‐sized soil particles has focused on single rainfall events. However, in the field, natural events interrupted by rainless periods of various durations follow one another. Some studies have shown that the amount of leached particles is much affected by the chronology of rainfall events. In this paper, we propose a model to compute the amount of mobilized particles during the transient flow regime of long series of successive rainfall events. Particles that can be mobilized are assumed to be located at the surface of preferential flow paths in contact with flowing water. As water passes, particles are mobilized, thus uncovering new particles and renewing the stock of mobilizable particles. We also report experimental data on the impact of long series of rainfall events on particle mobilization in undisturbed calcareous soil columns under controlled conditions. The model provides a framework to understand the variation of mobilization observed during the transient flow regime of these rainfall events. These variations resulted in part from the interplay between macropore water content at the onset of rain and the chronology of previous rainfall events. Additionally, the model provides a feedback loop between particle mobilization and minute macropore structure modifications. Once coupled with a particle transport model this feature may be useful to model soil structure changes during long series of successive rainfall events. 相似文献