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101.
Treatment of antibiotics and antibiotic resistant bacteria in swine wastewater with free chlorine 总被引:2,自引:0,他引:2
Qiang Z Macauley JJ Mormile MR Surampalli R Adams CD 《Journal of agricultural and food chemistry》2006,54(21):8144-8154
Recent recognition of the occurrence of antibiotics in the environment has highlighted concerns regarding potential threats of antibiotics to humans and wildlife. Antibiotics are commonly applied to animals to prevent diseases and promote growth, making livestock agriculture a major source of antibiotic pollution. The purpose of our study was to examine chlorination technology as a method for preventing the release of antibiotics as well as antibiotic-resistant bacteria into the environment from concentrated animal feeding operations. Wastewaters from various sites of two anaerobic lagoon systems, one aerated and the other not, on a swine facility were investigated. Each system consisted of a primary treatment lagoon and a subsequent polishing lagoon. Free chlorine (or monochloramine for comparison) was applied to oxidize antibiotics and to disinfect lagoon bacteria as well. Results indicate that aeration substantially improves lagoon functionality, thereby adding both organic and ammonia removal. Ammonia present in the wastewaters plays a critical role in antibiotics decomposition and bacterial inactivation due to its rapid competition for free chlorine to form monochloramine. Generally, a chlorine dose close to breakpoint is required to achieve complete removal of antibiotics, leading to high consumption of free chlorine in most of the wastewaters examined. However, because of a low ammonia concentration in the polishing lagoon wastewater of the aerated system, a chlorine dose of 100 mg/L can effectively achieve complete removal of both antibiotics and bacteria. On the basis of our experimental findings, a possible strategy for the treatment of swine wastewater is suggested. 相似文献
102.
103.
Baumgartner C Bollerhey M Henke J Wagner S Ungerer M Erhardt W 《Veterinary anaesthesia and analgesia》2008,35(2):100-112
OBJECTIVE: To evaluate the cardiovascular effects of intravenous propofol in rabbits. STUDY DESIGN: Randomized, prospective, experimental study. ANIMALS: Thirty-one female New Zealand White rabbits. METHODS: Rabbits were allocated to one of two groups [propofol (P) or conscious (C)]. In C (n = 16) vascular dimensions were measured using ultrasound of the left common carotid artery (ACC) and the abdominal aorta (AA). Group P (n = 15) received propofol 4.0-8.0 mg kg(-1) intravenously (IV). Anaesthesia was maintained with propofol at 1.2-1.3 mg kg(-1) minute(-1). Subsequently, three propofol injections (8 mg kg(-1)) were given. Before and for 10 minutes after each injection the following vascular and haemodynamic variables were recorded (a) at the ACC after the first injection; and (b) at the AA after the second injection: vessel diameter [D, (mm)], peak systolic, minimum diastolic, end-diastolic and average blood flow velocities [psBFV, mdBFV, edBFV, Vave (cm second(-1))], average volumetric flow [VFave (mL s(-1))], resistance index (RI) and pulsatility index (PI) mean arterial pressure (MAP), heart rate (HR), arterial oxygen saturation (SpO(2)) and end-tidal CO(2) (Pe'CO(2)). Echocardiography was performed after the third propofol bolus injection to investigate changes in cardiac parameters [fractional shortening, FS (%)]. RESULTS: Intravenous propofol injections caused a significant decrease in vessel diameter, volumetric flow and edBFV, and significant increases in psBFV, RI and PI. Baseline levels for vessel diameter and psBFV were restored 6-8 minutes after injection. Propofol injection decreased FS significantly by 7 minutes after injection while MAP and HR were significantly reduced for 4 minutes. CONCLUSION AND CLINICAL RELEVANCE: Injections of propofol (8 mg kg(-1)) produced an immediate, transient decrease in vascular diameters, a significant decrease in ventricular performance and an increase in peripheral vascular resistance (ACC and AA). Propofol should probably not be or only carefully used in rabbits with ventricular dysfunction. 相似文献
104.
Gunadhish Khanal Christine Wachendorf Klaus Dittert Melanie Willich Herbert Dietz Andreas Buerkert Mariko Ingold 《植物养料与土壤学杂志》2019,182(5):836-845
Under the hot and moist conditions of irrigated agriculture in the arid subtropics, turnover of organic matter is high, which can lead to considerable carbon (C) and nitrogen (N) losses. Therefore, sustainable use of these soils requires regular manure application at high rates. To investigate the contribution of consecutive manure applications to an arid sandy soil to various soil N pools, goat manure was isotopically labeled by feeding 15N‐enriched Rhodes grass hay and applied to the soil during a two‐year field experiment. In the first year, soils received 15N‐labeled manure to distinguish between soil‐derived and manure‐derived N. In the second year, these plots were split for the application of either 15N‐labeled or unlabeled manure to discriminate N derived from previous (first year) and recent (second year) manure application. Soil samples (of control and 15N‐manured soil) were collected at the end of the first and the second year, and incubated in two laboratory experiments with labeled or unlabeled manure. At the beginning of Experiment 1, 7% of total N, 11% of K2SO4 extractable N, and 16% of microbial biomass N were derived from previously field‐applied manure. While the application of manure during incubation increased microbial biomass N by 225% and 410% in the control soil and the previously field‐manured soil, respectively, N2O emissions were more affected on the control soil, releasing considerable amounts of the soil N‐pool (80% of total emissions). In Experiment 2, 4% of total N, 7% of K2SO4 extractable N, and 7% of microbial biomass N derived from previously applied manure, and 4%, 8%, and 3% from recently applied manure, respectively. Microbial biomass N and N2O‐N derived from manure declined with time after manure application, whereas in Experiment 1 this tendency was only observed for microbial biomass N. 相似文献
105.
Baumgartner C Bollerhey M Ebner J Laacke-Singer L Schuster T Erhardt W 《Canadian journal of veterinary research》2010,74(3):200-208
The direct effects of ketamine-xylazine (KET-XYL) on vascular function have not been investigated in rabbits. The short-term cardiovascular effects of intravenous (IV) KET-XYL bolus injection, therefore, should be investigated using vascular ultrasonography.In this prospective experimental study, KET-XYL anesthesia was induced IV in 9 female New Zealand White rabbits before 3 defined test bolus injections of KET-XYL were given IV. Before and for 10 min after each KET-XYL injection vascular and hemodynamic variables were recorded at the left common carotid artery (ACC) after the 1st injection, and at the abdominal aorta (AA) after the 2nd injection. Echocardiography was performed after the 3rd injection to investigate changes in cardiac parameters.Ketamine-xylazine IV caused a significant increase in vessel diameter at the ACC and AA. Average volumetric flow significantly decreased at the ACC and pulsatility index significantly decreased at the AA. Fractional shortening (FS) and heart rate significantly decreased, while mean arterial blood pressure initially increased.Bolus injections of KET-XYL IV produced a transient vasodilatation at the ACC and AA. Despite central vasodilatation, bradycardia, and decrease of FS and average volumetric flow (VFave), mean arterial blood pressure did not significantly decrease indicating well-preserved cardiovascular compensatory mechanism after the ratio and doses of KET-XYL IV bolus injections used in this study. 相似文献
106.
Sakiko Okumoto Karen Deuschle Marcus Fehr Melanie Hilpert Ida Lager Sylvie Lalonde 《Soil Science and Plant Nutrition》2013,59(7):947-953
Many of the genes encoding important trans porters and metabolic enzymes have been identified over the last ten years. Moreover it has been possible to study the biochemical properties of the corresponding proteins in great detail. It is expected that by 2,010 biochemical functions will have been assigned to many of the products of the approximately 30,000 Arabidopsis genes. We will get closer to understanding the biological function of the gene products by systematic analysis of mutants using knock-out and TILLING approaches. Metabolomics initiatives complement these approaches by providing insight into the changes in cellular ion and metabolite profiles in the mutants, thus giving information essential for the construction of cellular and whole plant models. However, one important dataset especially relevant to multicellular organisms is lacking: the knowledge of the spatial and temporal profiles of ions and metabolite levels at cellular and subcell ular levels. To address this issue, we have developed protein-based nanosensors for several metabolites, providing a set of tools for the determination of cytosolic and subcellular ion (e.g. iron and zinc) and metabolite levels in real time using fluorescence-based microscopy. The prototypes of these sensors were shown to function in vitro and also in vivo, i.e. in yeast and in mammalian cell cultures. One future goal is to expand the set of sensors to a wider spectrum of targets by using the natural spectrum of periplasmic binding proteins from bacteria and by computational design of proteins with altered binding pockets. Application of nanosensor technology to plant cells and tissues will help to elucidate the special and temporal distribution of ions and metabolites. 相似文献
107.
Josef Knott Melanie Mueller Joachim Pander Juergen Geist 《Ecology of Freshwater Fish》2020,29(1):74-88
Hydropower structures hinder the movement and migration of fishes, impairing their life cycles. Additionally, downstream moving fish are often at risk of being injured during turbine passage. To improve hydropower production towards more fish-friendly techniques and management, knowledge on timing and extent of natural patterns of fish downstream movement is necessary. So far, migration behaviour of long-distance migrators such as eel or salmon has been well studied, but little is known about seasonal and diurnal movement patterns of nonmigratory species or medium-distance migrators. In this study, movement patterns of 39 fish species captured by stownets while transiting hydropower facilities in four impounded rivers were assessed and compared with the fish community composition directly upstream of the hydropower plants assessed by electrofishing. Strong differences between the fish community composition inhabiting the upstream sides of the dams and the fish detected in downstream passage were evident. In each study river, the downstream moving fish community composition differed significantly between spring and autumn. On average, significantly more fish were caught during the night (2.9 fish/hr) than during the day (1.3 fish/hr). Topmouth gudgeon, European grayling and pike-perch mostly moved downstream during the night, whereas roach, spirlin and bleak were the most frequent downstream moving fish during daytime. Downstream fish movement was positively related with turbidity, water temperature and discharge. The strong differences in seasonal and diurnal fish movement patterns suggest that fish damage can be strongly reduced by adaptive turbine and corridor management, for example by shutting down turbines at peak movements. 相似文献
108.
Melanie Caffe‐Treml Karl D. Glover Padmanaban G. Krishnan Gary A. Hareland 《Cereal Chemistry》2010,87(6):574-580
Because of the large number of cultivars that require examination in the development of spring wheat (Triticum aestivum L.) cultivars, breeding programs use predictive methods to test end use quality. The Mixograph is a widely used predictive test with which end use quality of many genotypes can be assessed in a short time. By comparison, the Mixolab is a relatively new device with additional capability that might be used for the same purpose. Our objective was to document variability of, and relationships among, 20 parameters obtained from Mixolab, Mixograph, and bake tests. Tests were performed on flour from 18 genotypes grown in 20 environments. Both genotype and environment had significant effects on quality parameter values. Several Mixograph and Mixolab parameters were highly significantly correlated, particularly when genotype mean values over environments were considered. Correlations between loaf volume and Mixolab parameters within environments were inconsistent and suggest that average genotype values over environments will be most useful. For example, the correlation between Mixolab stability and loaf volume (r = 0.25, P < 0.001) was much higher when genotype averages (r = 0.70, P < 0.001) were considered. Our results show that selection for Mixolab stability and water absorption should help delineate and improve the selection of genotypes with greater loaf volume. 相似文献
109.
Melanie D. Jones Mark H. R. BRowning Thomas C. Hutchinson 《Water, air, and soil pollution》1986,31(1-2):441-448
Acid deposition may adversely affect northern forest ecosystems by increasing the concentration of metals in the soil solution. This study investigates the effects of ectomycorrhizal fungi on paper birch and jack pine seedlings exposed to elevated Cu, Ni, or Al in sand culture. One of four mycorrhizal fungi,Scleroderma flavidum, was able to reduce Ni toxicity to the birch seedlings. It did this by reducing transport of Ni to the stems. None of the fungi affected Cu toxicity in birch. In separate experiments, jack pine seedlings were exposed to combinations of Al and Ca. Infection withRhizopogon rubescens increased seedling susceptibility to A1. Seedlings inoculated withSuillus tomentosus showed a greater growth stimulation by Ca than uninoculated jack pines. Thus, for both tree species, the mycorrhizal association could alter the response of seedlings to high concentrations of certain metals, although this varied with fungal species. 相似文献
110.
Jingping Guo Anneleen Swanepoel Xuan Qiu Joo Reis Melanie Rhodes D. Allen Davis 《Aquaculture Nutrition》2020,26(2):490-501
A series of trials were conducted with Pacific white shrimp Litopenaeus vannamei, to evaluate the efficiency of two salmon meals as compared to anchovy meal. The basal diet contained 200 g/kg anchovy meal, which was systematically replaced (0%, 50%, 75% and 100%) with salmon meal on an isonitrogenous basis. Another two diets were formulated with a hydrolysed salmon meal to replace 50% and 100% anchovy meal. Each diet was randomly fed to four replicate groups of 25 and 30 shrimp per tank in clear (indoor) and green (outdoor) water trials, respectively. The results showed that growth performance and feed conversion ratio were not statistically different when salmon meal replaced anchovy meal in both trials. However, when hydrolysed salmon meal was used to replace 100% of the anchovy meal, growth performance of the shrimp significantly decreased. The four kinds of fish meal (anchovy, salmon by‐product meals and menhaden) were evaluated in an ingredient digestibility trial using the 70:30 replacement technique. In general, dry matter, energy, protein and individual amino acids digestibility of salmon meal were significantly higher than those of menhaden and anchovy meal. Results of this study demonstrated that salmon meals are a good protein sources which can replace anchovy meal. 相似文献