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11.
K. Håkan Olsén J. Torbjörn Järvi Ian Mayer Erik Petersson Frederieke Kroon 《Chemoecology》1998,8(1):9-17
Summary. In the present experiment the behaviour and endocrine status of males of the brown trout, Salmo trutta L., (Salmoniformes: Salmonidae) were studied when males were kept in a stream tank with a nest digging female. Groups of
mature adult males and precocious intact or anosmic male parr were placed with the nesting female so that the group resembled
a natural spawning situation with big anadromous fish acting as dominant males and precocious parr acting as “sneakers”. A
control experiment was also run with only males without a female present. In intact parr there were significant positive correlations
between the per cent of the total observation time spent with a female, milt volume, and plasma concentration of 17α, 20β-dihydroxy-4-pregnen-3-one.
Anosmic parr had significantly lower volumes of strippable milt and gonadal steroid hormone levels compared with intact parr.
However, no differences were found in the control experiment. Significantly fewer anosmic parr attended and courted the nesting
female and those anosmic fish that attended the female had significantly lower plasma levels of gonadal hormones. Intact parr
also displayed a greater number of agonistic acts against other parr without any difference in fighting ability. No differences
in aggression occured in the control experiment. In adult males together with a female, post-experimental gonadal steroid
hormone levels were higher than pre-experimental levels. Positive correlations between aggression and androgen hormone levels
were observed in adult males. No differences in plasma hormone levels were observed between adult males and intact precocious
males. The results show that olfactory occlusion results in low steroid hormone levels and milt volumes in precocious males
placed in a spawning situation. The courting behaviour was also affected by anosmia. Odours from the nesting female may have
caused the enhanced plasma hormone levels and stimulated the males to attend the female.
Received 15 May 1997; accepted 29 June 1997. 相似文献
12.
Preparation of a porous clay heterostructure and study of its adsorption capacity of phenol and chlorinated phenols from aqueous solutions. 总被引:1,自引:0,他引:1
Sofía Arellano-Cárdenas Tzayhrí Gallardo-Velázquez Guillermo Osorio-Revilla Ma del Socorro López-Cortez 《Water environment research》2008,80(1):60-67
A porous clay heterostructure (PCH) from a Mexican clay was prepared and characterized, and its aqueous phenol and dichlorophenols (DCPs) adsorption capacities were studied using a batch equilibrium technique. The PCH displayed a surface area of 305.5 m2/g, 37.2 A average porous diameter, and a basal space of 23.2 A. The adsorption capacity shown by the PCH for both phenol and DCPs from water (14.5 mg/g for phenol; 48.7 mg/g for 3,4-DCP; and 45.5 mg/g for 2,5-DCP) suggests that the PCH has both hydrophobic and hydrophilic characteristics, as a result of the presence of silanol and siloxane groups formed during the pillaring and calcination of the PCH. The values of maximal adsorption capacity for dichlorophenols were higher than those reported for aluminum pillared clays and some inorgano-organo clays and comparable with some ionic exchange resins. 相似文献
13.
In multiphase systems capillary pressures play a significant role on fluid movement and retention. The facility to predict
the effect of different thermal remediation strategies requires the knowledge of the effect of temperature on capillary pressure-saturation
relationships in the soils.
The objective of recent study was (a) to develop a technique for routinely measuring the pressure-saturation curves of soil
samples saturated with a nonpolar liquid at different regulated temperatures (b) to build a database using the measured pressure-saturation
curves and the physical, chemical properties of the model soils (c) to establish the dependence of nonaqueous phase liquid
retention on the soil properties and the temperature.
The retention curves (extraction isotherms) with nonaqueous phase liquid were determined using a modified
pressure plate extractor. The wetting phase was a non-aromatic hydrocarbon distillation product. Pressure plates were designed and constructed in
the laboratory of our department. The temperature was held constant at 20, 40 and 60 ∘C.
Statistical analysis was performed involving selected soil parameters and the measured nonaqueous phase liquid retention data.
The results show that knowing some easily measurable soil parameters (bulk density, particle size distribution, humus and
lime content) we can estimate the nonaqueous phase liquid retention of the soils. The measured “extraction isotherms” provide
essential information about the temperature-dependency of pressure-saturation curves. 相似文献
14.
Solá María Zoleica Simón Prado Carolina Rosa Mariana Aráoz María Victoria Coll Benimeli Claudia Susana Polti Marta Alejandra Alvarez Analia 《Environmental science and pollution research international》2021,28(37):51217-51231
Environmental Science and Pollution Research - Phytoremediation techniques have been proposed as ecological methods to clean up contaminated sites. This study is aimed to evaluate the effect of the... 相似文献
15.
M.A. Bustamante D. Said-Pullicino E. Agulló J. Andreu C. Paredes R. Moral 《Agriculture, ecosystems & environment》2011,140(1-2):80-87
The effects on different physico-chemical, chemical and biological soil properties of the incorporation of different organic materials into a calcareous vineyard soil were studied in an experiment during three growing seasons. The organic materials used were sheep manure and four composts derived from the treatment of winery and distillery wastes. A multivariate technique, factor analysis (FA), was also used for interpreting the data obtained from the samplings carried out throughout the three vine growing seasons. The application of the organic materials induced an increase in the activity of the soil microorganisms and in the soil macro and micronutrient contents, as well as a slow release of inorganic N. Through FA of the soil properties studied, three factors that explained 74.7% of the variability were established and the effects of the treatments after the whole experimental period were assessed. 相似文献
16.
ISO 14001 certification and financial performance: selection-effect versus treatment-effect 总被引:1,自引:0,他引:1
Iñaki Heras-Saizarbitoria José F. Molina-Azorín Gavin P.M. Dick 《Journal of Cleaner Production》2011,19(1):1-12
The paper explores the bi-directional relationship between ISO 14001 certification and financial performance with the aim of shedding light on whether better performance is due to the beneficial effects of ISO 14001 or due to selection-effects where better performance precedes accreditation. The study uses a five year longitudinal analysis to compare the financial performance of firms in Spain before and after certification. The results of a multivariate panel data analysis find that firms with better than average performance have a greater propensity to pursue accreditation but there is no evidence that improvements in performance follow certification. This suggests that the inference that environmental variables cause improved financial performance may be unwise in research studies that can only measure association. 相似文献
17.
Alvarez-Muñoz D Lara-Martín PA Blasco J Gómez-Parra A González-Mazo E 《Environment international》2007,33(4):565-570
The presence of linear alkylbenzene sulfonates (LAS) and their degradation intermediates, sulfophenylcarboxylic acids (SPCs), with concentrations up to 100 ppb has been found in surface waters taken from the estuary of the river Guadalete (Cádiz, SW of Spain). Higher concentrations were found at the sampling site located adjacent to the discharge outlet of a wastewater treatment plant (WWTP). The concentrations decreased downstream to a few ppb as a result of dilution, sorption, and degradation processes, which were taking place along the estuary. Once the presence of both xenobiotics was confirmed in the environment, an in vivo assay was conducted to study their biotransformation and effects in the benthic fish Solea senegalensis. A flow-through system was employed, consisting of an exposure phase (120 h) with environmental levels of the surfactant (200, 500 and 800 microg/L of 2?C(10)LAS), followed by a depuration stage (72 h). The generation of SPCs has been quantified during these phases in both water and fish, with LAS biotransformation shown in all cases. The antioxidant enzymes catalase (CAT), glutathione peroxidase (GPX), glutathione reductase (GR), the phase II enzyme glutathione S-transferase (GST), and the phase III acid and alkaline phosphatases (AcP, ALP) were also estimated and utilized as biomarkers. 相似文献
18.
Hannah K. Larson Shana K. Goffredi Erica L. Parra Orlando Vargas Adrián A. Pinto-Tomas Terrence P. McGlynn 《Die Naturwissenschaften》2014,101(5):397-406
We document a facultative Bartonella-like Rhizobiales bacterium in the giant tropical ant, Paraponera clavata. In a lowland tropical rainforest in Costa Rica, 59 colonies were assayed for the prevalence of the Bartonella-like bacterium (BLB), 14 of which were positive. We addressed three questions: First, how does the prevalence of BLB within colonies vary with environmental conditions? Second, how does diet affect the prevalence of BLB in P. clavata? Third, how does the distribution of BLB among colonies reflect ambient differences in food resources and foraging habits? A variety of environmental variables that may be predictive of the presence of BLB were measured, and diet manipulations were conducted to test whether the prevalence of BLB responded to supplemental carbohydrate or prey. The ambient frequency of BLB is much higher in young secondary forests, but is nearly absent from older secondary forests. The prevalence of BLB inside field colonies increased over the duration of a 2-week carbohydrate supplementation; however, water and prey supplementation did not alter the prevalence of BLB. The diets of the colonies located in young secondary forest, compared to other habitats, have a diet richer in carbohydrates and lower in prey. The abundance of carbohydrate, or the relative lack of N, in a colony’s diet influences the occurrence of the BLB microbe in P. clavata. As experimental diet manipulations can affect the facultative presence of an N-cycling microbe, a consistent diet shift in diet may facilitate the emergence of tighter symbioses. 相似文献
19.
Bilgili Levent Çetinkaya Afşın Yusuf 《Journal of Material Cycles and Waste Management》2023,25(1):324-336
Journal of Material Cycles and Waste Management - In this study, an average waste composition was determined using the Provincial Environmental Status Reports of 81 provinces in Turkey for 2019,... 相似文献
20.
García del Barrio JM Ortega M Vázquez De la Cueva A Elena-Rosselló R 《Environmental monitoring and assessment》2006,119(1-3):137-159
This paper mainly aims to study the linear element influence on the estimation of vascular plant species diversity in five Mediterranean landscapes modeled as land cover patch mosaics. These landscapes have several core habitats and a different set of linear elements -habitat edges or ecotones, roads or railways, rivers, streams and hedgerows on farm land- whose plant composition were examined. Secondly, it aims to check plant diversity estimation in Mediterranean landscapes using parametric and non-parametric procedures, with two indices: Species richness and Shannon index.Land cover types and landscape linear elements were identified from aerial photographs. Their spatial information was processed using GIS techniques. Field plots were selected using a stratified sampling design according to relieve and tree density of each habitat type. A 50×20 m2 multi-scale sampling plot was designed for the core habitats and across the main landscape linear elements. Richness and diversity of plant species were estimated by comparing the observed field data to ICE (Incidence-based Coverage Estimator) and ACE (Abundance-based Coverage Estimator) non-parametric estimators.The species density, percentage of unique species, and alpha diversity per plot were significantly higher (p < 0.05) in linear elements than in core habitats. ICE estimate of number of species was 32% higher than of ACE estimate, which did not differ significantly from the observed values. Accumulated species richness in core habitats together with linear elements, were significantly higher than those recorded only in the core habitats in all the landscapes. Conversely, Shannon diversity index did not show significant differences. 相似文献