Multi-party responses to environmental problems. A case of contaminated dairy cattle     

George E. B. Morren Jr. 《Agriculture and Human Values》1989,6(4):30-39

This paper presents a framework for exploring the temporal and behavioral aspects of the responses of various involved parties that may lead to governmental intervention in situations involving exposure of the public to hazardous substances. The activities of key individuals are closely scrutinized. Relevance of the framework to agricultural and food concerns is also indicated. The exemplary case is the contamination of livestock in Michigan that began in 1973, but other cases are discussed that conform closely to the pattern described by the framework.George Morren is Associate Professor of Anthropology and Ecology in the Department of Human Ecology at Cook College, Rutgers, the State University of New Jersey, where he coordinates the International Environmental Studies Program. His areas of interest include tropical human ecology and social responses to hazards. He has done field research in Papua, New Guinea, northern Europe, and the U. S. and is currently studying public participation in environmental affairs in New Jersey and long term forest change in Papua, New Guinea. He is co-author (with Kathleen Wilson) ofSystems Approaches for Improvement in Agriculture and Resource Management, MacMillan, 1990.  相似文献   

Molecular characterization of tetracycline- and quinolone-resistant Aeromonas salmonicida isolated in Korea     

Ji Hyung Kim  Sun Young Hwang  Jee Soo Son  Jee Eun Han  Jin Woo Jun  Sang Phil Shin  Casiano Choresca  Jr  Yun Jaie Choi  Yong Ho Park  Se Chang Park 《Journal of veterinary science (Suw?n-si, Korea)》2011,12(1):41-48

The antibiotic resistance of 16 Aeromonas (A.) salmonicida strains isolated from diseased fish and environmental samples in Korea from 2006 to 2009 were investigated in this study. Tetracycline or quinolone resistance was observed in eight and 16 of the isolates, respectively, based on the measured minimal inhibitory concentrations. Among the tetracycline-resistant strains, seven of the isolates harbored tetA gene and one isolate harbored tetE gene. Additionally, quinolone-resistance determining regions (QRDRs) consisting of the gyrA and parC genes were amplified and sequenced. Among the quinolone-resistant A. salmonicida strains, 15 harbored point mutations in the gyrA codon 83 which were responsible for the corresponding amino acid substitutions of Ser⁸³→Arg⁸³ or Ser⁸³→Asn⁸³. We detected no point mutations in other QRDRs, such as gyrA codons 87 and 92, and parC codons 80 and 84. Genetic similarity was assessed via pulsed-field gel electrophoresis, and the results indicated high clonality among the Korean antibiotic-resistant strains of A. salmonicida.  相似文献   

Methane emission and entrapment in flooded rice soils as affected by soil properties   总被引：7，自引：0，他引：7  

Z. P. Wang  C. W. Lindau  R. D. Delaune  W. H. Patrick Jr. 《Biology and Fertility of Soils》1993,16(3):163-168

Laboratory incubation experiments were conducted to study the effects of soil chemical and physical properties on CH₄ emission and entrapment in 16 selected soils with a pH range of 4.7–8.1, organic matter content of 0.72–2.38%, and soil texture from silt to clay. There was no significant correlation with CH₄ emission for most of the important soil properties, including soil aerobic pH (measured before anaerobic incubation), total Kjeldahl N, cation exchange capacity, especially soil organic matter, and soil water-soluble C, which were considered to be critical controlling factors of CH₄ emission. A lower CH₄ emission was observed in some soils with a higher organic matter content. Differences in soil Fe and Mn contents and their chemical forms contributed to the this observation. A significant correlation between the CH₄ emission and the soil organic C content was observed only after stratifying soils into subgroups according to the level of CH₄ emission in soils not amended with organic matter. The results also showed that the soil redox potential (Eh), anaerobic pH, anerobic pH, and biologically reducible Fe and Mn affected CH₄ emission significantly. Urea fertilization promoted CH₄ emission in some soils and inhibited it in others. This result appeared to be related to the original soil pH. CH₄ entrapment was positively correlated with soil clay content, indicating the importance of soil physical characteristics in reducing CH₄ emissions to the atmosphere.  相似文献   

Scientific goals and experiments of the project “winter precipitation at Mount Rigi”: An overview     

J. Staehelin  A. Waldvogel  J. L. Collett Jr.  R. Dixon  R. Heimgartner  W. Henrich  C. Hsu  L. Li  L. Mosimann  B. Oberholzer  A. S. H. Prevot  W. Schmid  T. Schumann  M. Steiner  M. Volken  B. Zinder 《Water, air, and soil pollution》1993,68(1-2):1-14

Wet deposition plays an important role as a mechanism for cleansing of the polluted troposphere. Fluxes of pollutants from the atmosphere to earth's surface can affect soil and aquatic ecosystems. The investigation of the pollutant incorporation into wet deposition is therefore of considerable interest for environmental research. The project “Winter precipitation at Mount Rigi” addresses the processes determining the chemical composition of wet deposition through an integrated approach considering atmospheric physical and chemical processes and their complex interactions. The investigated topics include: aerosol and gas scavenging, atmospheric chemistry (cloud water chemistry), cloud physics and dynamics. The design of the experiment, using three ground based measuring stations at the northwestern slope of the mountain, and the conceptual ideas using case study investigations are discussed.  相似文献   

Contributions of cloud processes to precipitation chemistry in mixed phase clouds     

J. L. Collett Jr.  B. Oberholzer  L. Mosimann  J. Staehelin  A. Waldvogel 《Water, air, and soil pollution》1993,68(1-2):43-57

The role clouds play as processors of atmospheric aerosols and trace gases was studied along the slope of Mt. Rigi in central Switzerland. Upon cloud formation many aerosols and trace gases are efficiently scavenged by cloud drops. The cloud drops can enhance removal of pollutants from the atmosphere by transferring them to snow or rain which falls rapidly to the ground. This often occurs through a process known as riming, where falling ice crystals capture cloud drops. When ice crystals are grown primarily via water vapor deposition, without significant capture of cloud drops, however, the cloud drops isolate atmospheric pollutants from the precipitation process, thereby inhibiting their deposition. Increased riming results in increased precipitation ion concentrations. The extent of ice crystal riming at times exhibits spatial inhomogeneities with greater riming apparent near the mountain summit. Variations in cloud chemistry with drop size indicate that bulk cloudwater composition is not an accurate predictor for the composition of cloud drops captured by the ice crystals.  相似文献   

Vertical distribution of soil mites (Acari) in conventional and no-tillage agricultural systems     

J. C. Perdue  D. A. Crossley Jr. 《Biology and Fertility of Soils》1990,9(2):135-138

Summary Soil mite abundance was measured at four depths (0–5, 6.5–11.5, 13–18, and 19.5–24.5 cm) in agricultural plots under no-tillage or conventional tillage in Clarke County, Georgia, USA. The vertical distribution of mites was not significantly different between the two tillage systems: Most mites were found in the top 0–5 cm zone. This was the zone where greater moisture content occurred, and (in other studies) was the zone of maximum root biomass and microbial activity. Among mite suborders, only the Prostigmata were found in any abundance below 5 cm. Mite populations declined dramatically on occasions when the soil moisture exceeded field capacity, but did not appear to migrate vertically.Dedicated to the late Prof. Dr. W. Kühnelt  相似文献   

Arsenic resistant microorganisms isolated from agricultural drainage water and evaporation pond sediments     

K. Davis Huysmans  W. T. Frankenberger Jr 《Water, air, and soil pollution》1990,53(1-2):159-168

Elevated levels of As in contaminated water and soil could pose a major threat to the environment. Relatively high levels of As have been reported in agricultural drainage water and in evaporation pond sediments in Kern County, California. The objective of this study was to enumerate and isolate As-resistant microorganisms from agricultural drainage water and evaporation pond sediments and to assess their tolerance to metals, metalloids and antibiotics. The culture medium was amended with arsenite (III), arsenate (V), methylarsonic acid (MAA), and dimethylarsinic acid (DMA). Among the water samples, As(V), MAA, and DMA added to the medium at concentrations from 0.1 to 1000 mg L^?1 showed no effect on the colony forming units (CFUs) compared with no As supplementation, while arsenite (III) (> 1.0 mg L^?1) inhibited the population. The sediments showed three trends: (i) no effect on CFUs in the presence of As(V) up to 1000 mg kg^?1, (ii) a decline in CFUs in the presence of > 100 mg kg^?1, As(III), and (iii) an increase in CFUs upon the addition of MAA or DMA at > 25 mg kg^?1, Arsenite (III) was much more toxic to the indigenous microflora than any other As species. Arsenite (III) inactivates many enzymes by having a high affinity for thiol groups of proteins. A plate diffusion method was used to assess the tolerance of the As-resistant bacteria to heavy metals, metalloids and antibiotics. Of 14 isolates tested, all were resistant to Co, Cu, Pb, Ni, Mo, Cr, Se(IV), Se(VI), As(III), As(V), Sb, Sn, and Ag (50 µg mL^?1). The most toxic trace elements were Cd followed by Hg>Te>Zn. Multiple antibiotic tolerance (resistance to 2 or more antibiotics) was found among 43% of the isolates. The As-resistant bacteria showed a high tolerance to metals and antibiotics.  相似文献   

Variations in the acid content of rain water in the course of a single precipitation     

Michael D. Seymour  Steven A. Schubert  J. Wesley Clayton Jr.  Quintus Fernando 《Water, air, and soil pollution》1978,10(2):147-161

The major acid components in the rain water collected during five different rainfall events in July and August 1977, were found to be a strong acid, the weak acid NH _in4 ^su+ and dissolved CO₂ from the atmosphere. Variations in their concentrations were determined as a function of time in the course of each of the rainfall events. Two experimental methods were used in this investigation, a microtitrim etric method and a coulometric method, and the data were analyzed by the use of modified Gran functions. Both methods gave the same results. The most significant observation was that the strong acid concentration increased from very low values to a maximum and then decreased in the course of a single rainfall event.  相似文献   

Effects of treatment and flow on the deoxygenation rate constant     

Yung-Tse Hung  W. Wesley Eckenfelder Jr.  Tom D. Reynolds 《Water, air, and soil pollution》1978,10(2):175-185

The laboratory bench-scale experiments were conducted to investigate the effects of varying degrees of waste treatment and the flow conditions in the receiving waters on the deoxygenation rate constant (k), and ultimate biochemical oxygen demand (L), and the total O₂ utilisation of the receiving waters. Industrial wastewaters were collected from 10 major industrial plants located along the Houston Ship Channel in Texas. Two different degrees of treatment for industrial wastewaters were studied. Three different flow conditions studied were the high, the average and the low flow in the Houston Ship Channel. The k values increased for both further treatment and decreased flow in the reactor runs. The L values were higher for the average flow conditions than for the low flow conditions. The total O₂ utilization was found to increase with a decrease in the flow of the receiving waters.  相似文献   

Response of soil invertebrates to forest canopy inputs along a productivity gradient     

Barbara C. Reynolds  D.A. Crossley Jr.Mark D. Hunter 《Pedobiologia》2003,47(2):127-139

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