Rating fixed film nitrifying biofilters used in recirculating aquaculture systems   总被引：1，自引：0，他引：1  

Ronald F. Malone  Timothy J. Pfeiffer 《Aquacultural Engineering》2006,34(3):389-402

Predicting the performance of biofilters is an engineering challenge that is critical to both designers and managers. The task is complicated by the wide variety of water quality expectations and environmental conditions displayed by a recirculating aquaculture system (RAS). A myriad of biofilters designs have been generated reflecting approaches of engineers attempting to maximize specific surface area and oxygen transfer within the context of a biofilm management strategy. A rating strategy is presented for biofilters to facilitate the identification of appropriate matches between biofiltration formats and RAS applications. As a foundation, a previously proposed RAS classification system based upon salinity, temperature and trophic levels is upgraded to create 17 systems classifications. A biofilter classification system identifies seven combinations of trophic level and pH which should be sufficient to serve the RAS demands. Temperature and salinity are neglected as a means of simplifying the approach. An experimental methodology based upon chemical feeds is proposed to represent the steady-state RAS performance of the biofilters. Data is summarized by linear analysis of filter performance for concentration ranges below 1.0 g TAN m⁻³ and simple averaging is proposed for higher trophic levels. Input from the aquacultural engineering community and RAS aquaculturists is required to further refine the approach prior to endorsement.  相似文献   

Enzyme-linked immunosorbent assay (ELISA) detection of infectious pancreatic necrosis virus (IPNV) in culture fluids and tissue homogenates of the rainbow trout, Salmo gairdneri Richardson     

L. RODÁK  Z. POSPÍ&#;IL  J. TOMÁNEK  T. VESELÝ  T. OBR  L. VALÍ&#;EK 《Journal of fish diseases》1988,11(3):225-235

Abstract. A double antibody enzyme-linked immunosorbent assay (ELISA) for the detection of infectious pancreatic necrosis virus (IPNV) is described. The sensitivity of the assay reached 10² TCID₅₀ per 0·1 ml of culture fluid. The specificity of anti-IPNV sera and of the assay was confirmed by agar-gel immunodiffusion, by the direct immunoperoxidase technique for the deletion of IPNV in tissue cultures and by the ELISA inhibition test. High values of specific inhibition (over 90% at serum dilutions 1:40–1:2560) and low values of non-specific inhibition (8·4% at serum dilution 1:160) demonstrated the quality of the rabbit anti-IPNV serum. The results of ELISA agreed well with those of virological examinations. The potential of ELISA for investigations of a large series of field samples is discussed.  相似文献   

斯洛伐克农田土壤环境学指标的研究     

J. VIL&#;EK  R. BUJNOVSK&# 《土壤圈》2014,24(1):137-144

The soil environmental index(SEI),which is a four digit code system,represents relatively homogenous spatial unit with specific soil capacity to provide ecological or non-production functions.This work aimed to present information on rating and economic evaluation of SEI,which is a spatial identifier used for expressing heterogeneity of Slovak agricultural soil to support analysis of soil ecological functions.In this study,SEI index expressed the capacity of soil to accumulate water,immobilise the risk elements and substances and transform risk substances(organic pollutants).Partial evaluations of soil capacity to provide above mentioned functions were used to derive final SEI values.Within the agricultural soils of Slovakia there were 493 combinations of soil environmental index.Each index was expressed through rating(point)value and economic value.Average value of Slovak agricultural land to provide selected ecological soil functions was 55.3 points,which corresponded to 35.946 billionper agricultural land or approximately 1.42per square meter.Spatial identification of SEI codes and relevant database were developed in vector form via geographical information systems of Soil Science and Conservation Research Institute,Bratislava.In addition to using the national soil database system,a strategy was presented for evaluating and pricing of soil ecological function,and the development of an soil environmental index.Assessment and evaluation of vitally important soil functions expressed by SEI can significantly contribute to planning and protection of the soil,and can regulate indiscriminate anthropic interventions in land use decisions.  相似文献   

Spatial Response of Mammals to Late Quaternary Environmental Fluctuations     

RW Graham  EL Lundelius  MA Graham  EK Schroeder  RS Toomey  E Anderson  AD Barnosky  JA Burns  CS Churcher  DK Grayson  RD Guthrie  CR Harington  GT Jefferson  LD Martin  HG McDonald  RE Morlan  HA Semken  SD Webb  L Werdelin  MC Wilson 《Science (New York, N.Y.)》1996,272(5268):1601-1606

Analyses of fossil mammal faunas from 2945 localities in the United States demonstrate that the geographic ranges of individual species shifted at different times, in different directions, and at different rates in response to late Quaternary environmental fluctuations. The geographic pattern of faunal provinces was similar for the late Pleistocene and late Holocene, but differing environmental gradients resulted in dissimilar species composition for these biogeographic regions. Modern community patterns emerged only in the last few thousand years, and many late Pleistocene communities do not have modern analogs. Faunal heterogeneity was greater in the late Pleistocene.  相似文献   

Veterinarians' preferences for anticonvulsant drugs for treating seizure disorders in dogs and cats   总被引：1，自引：1，他引：0  

EK Kluger  R Malik  M Govendir 《Australian veterinary journal》2009,87(11):445-449

Objective   To identify veterinarians' approaches and concerns when managing canine and feline patients with acute and chronic seizure disorders.
Design   Cross-sectional survey.
Method   A questionnaire was distributed to veterinarians to determine how many dogs and cats they were actively treating for seizures, their anticonvulsant drug (ACD) preferences for treating acute and chronic seizure disorders and whether serum anticonvulsant concentrations and/or biochemical analytes were routinely measured. Additional questions involved the respondent's year and place of graduation and identified concerns they faced when managing patients with seizure disorders.
Results   Phenobarbitone was the most commonly used ACD for managing chronic seizure disorders in both dogs and cats, with 82% of respondents using a combination of phenobarbitone and potassium bromide to manage refractory seizure disorders in dogs. Most respondents (96%) felt comfortable managing seizures in dogs, but only 63% were comfortable managing affected cats. Routine monitoring of serum ACD concentrations and of liver biochemical analytes was performed routinely by 71% and 45% of respondents, respectively. Of the respondents, 86% graduated from Australian universities and of these 53% had graduated after 1985.
Conclusion   Veterinarians identified when to commence medication, whether regular monitoring of serum ACD concentrations and liver enzyme activity was necessary, and if the cost was justified. Veterinarians also identified the need to balance dose rates and side-effects by using combination therapy, and the importance of providing accurate information to clients about what to expect in terms of seizure control for their pet.  相似文献   

Long-term development of fish populations in the Římov Reservoir     

M. &#;ÍHA  J. KUBE&#;KA  M. VA&#;EK  J. SE&#;A  T. MRKVI&#;KA  M. PRCHALOVÁ  J. MAT&#;NA  M. HLADÍK  M. &#;ECH  V. DRA&#;TÍK  J. FROUZOVÁ  E. HOHAUSOVÁ  O. JAROLÍM  T. J&#;ZA  M. KRATOCHVÍL  J. PETERKA  & M. TU&#;ER 《Fisheries Management and Ecology》2009,16(2):121-129

Abstract  The inshore fish community of the Římov Reservoir in the Czech Republic was evaluated over 21 years using shore seining at night. The development of the fish community was divided into two separate phases: a highly dynamic and unstable phase dominated by perch, Perca fluviatilis L., was replaced by an extremely stable cyprinid phase dominated by roach, Rutilus rutilus (L.), and bream, Abramis brama (L.). The abundance of both these species oscillated during the cyprinid phase, but with decreasing amplitude. The proportion of piscivorous fish species such as asp, Aspius aspius (L.), pike, Esox lucius L., and pikeperch, Sander lucioperca (L.), increased slightly with time but remained low. The biomass of large Cladocera was negatively correlated with fish biomass only during the perch phase. The Shannon–Weaver index of diversity increased during the fish community succession, mainly because of greater evenness amongst the species.  相似文献   

EPSPS gene amplification confers resistance to glyphosate resistant populations of Hordeum glaucum Stued (northern barley grass) in South Australia     

Patricia Adu‐Yeboah  Jenna M Malone  Benjamin Fleet  Gurjeet Gill  Christopher Preston 《Pest management science》2020,76(4):1214-1221

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High and dry in days gone by: Life-history theory predicts Appalachian mountain stream fish assemblage transformation during historical drought     

Eric W. Malone  Joshuah S. Perkin  William Keith Gibbs  Matthew Padgett  Matthew Kulp  Stephen E. Moore 《Ecology of Freshwater Fish》2022,31(1):29-44

Understanding the ecological dimensions of drought is critical for predicting how humans and nature will be affected by the expected increased prevalence of drought in the future. We tested life-history-based predictions for fish assemblage responses to drought using retrospective analysis of long-term (1986–2003) fish surveys from two streams in the Appalachian Mountains of North America. We hypothesised that (1) fish assemblage composition would correlate with wet and dry hydrologic conditions as assemblages fluctuated within a loose equilibrium and (2) life-history traits of fishes would correlate with dry versus wet periods such that opportunistic life-history strategists would dominate during drought. Results showed fish assemblage changes in Little River and Cataloochee Creek correlated with drought severity measured one year prior to fish surveys. Fish assemblages at all three sampling sites in Little River and two sites in Cataloochee Creek fluctuated within a loose equilibrium, while the remaining two sites in Cataloochee Creek indicated directional change. Life-history traits for fishes in Cataloochee Creek correlated with one-year time lag fluctuations in drought caused by opportunistic species being dominant during drought and periodic/equilibrium species dominant during wet periods. Time series plots of fish abundances aggregated by life-history strategy revealed dominance of opportunistic species emerged at the onset of a multi-year drought spanning 1998–2004, particularly for the two sites undergoing directional change. Our work provides empirical evidence for theoretical linkages between life history and environmental fluctuations and can ultimately be used to predict stream fish community response to future drought regimes.  相似文献