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101.

Background, Aim and Scope

Models describing in- and exfiltration of sewer systems require a large amount of data for calibration. These are often difficult and expensive to measure and to acquire. Therefore, this paper aims at clarifying whether results from various measurement campaigns might be joined to broaden the basis of an exfiltration model. Within this context, the transferability of exfiltration rates from one sewer (or catchment) to another is one of the crucial points.

Materials and Methods

Exfiltration rates derived from field measurements and from literature (field and laboratory investigations) are compared with respect to - Catchment characteristics- Applied methods: tracer tests, blocking tests, and laboratory investigations- Experimental site: laboratory and field studies - Leakage area: Closed-circuit television (CCTV) serves as a substitute for sewer characteristics. From those records the leakage area is obtained calculating an exfiltration rate per day and cm² leakage area.

-

Exfiltration was measured in two catchments and the findings were compared with published data for two catchments and two laboratory studies. As expected, exfiltration rates exhibit a wide range. We investigated whether the experimental design dominates the variance of measured data. The results are compared by means of statistical methods (Kruskal-Wallis analysis of ranks, Bootstrapping, and analysis of covariance-ANCOVA) to reveal significant differences in means.

Results

The statistical analysis yields significant differences in exfiltration rates comparing the results obtained (i) in either field or laboratory and (ii) with different methods. Exfiltration rates measured in various catchments are not significantly different.

Discussion

It can be shown that exfiltration rates obtained from field studies are affected by the measurement technique, whereas for laboratory investigations, the measurement technique does not influence the result in the first place. It is therefore difficult to jointly analyse laboratory and field experiments, i.e. a transfer of exfiltration rates from laboratory investigations to operational sewers is hardly feasible. It is also shown that results from different catchments are better suited for a joint assessment than results from differing methods.

Conclusions

A joint assessment of exfiltration rates obtained in various studies is not feasible with the available datasets.

Recommendations and Perspective

:A standardisation of methods would allow for optimal analysis of exfiltration rates measured by different researchers or operators.
  相似文献   
102.
The aim of this study was to prove if oxidation-reduction levels in the follicular fluid were new functional indices of follicular health and whether there was a high level of accordance with endocrinological parameters and with the growth stage as detected by ultrasound monitoring of individual follicles during the oestrous cycle in mares. Follicles were classified as growing and regressing follicles using ultrasonography. Altogether 48 follicles with a diameter from 20 to 56 mm were aspirated by transvaginal ultrasound guided follicular aspiration. Follicular concentration of oestradiol and progesterone in relation to the diameter of growing follicles showed correlations of r = 0.64 and r = 0.57, respectively. The redox potential derived index D2 varied from -448 to +431 in the collected fluids of the follicles. The accordance of the judgement of all follicles using both complexes of methods - endocrinological and ultrasonographic parameters vs. analysis of oxidation and reduction levels - reached 72.5%. This finding has shown that parameters of redox reactions do not correlate closely with the stage of follicular growth or regression as determined by in vivo scanning of ovaries or by assessment of follicular steroid concentrations. However, the measurement of redox potentials offers an opportunity to examine the whole process of metabolism in follicular cells and to forecast impairments of cellular performances. Changes of redox parameters in growing follicles enable an earlier prediction of their further development. The data demonstrate that growing and regressing follicles do not represent nonatretic, early atretic and atretic follicles, respectively.  相似文献   
103.
Genetically modified (GM) animals are unique mutants with an enormous scientific potential. Cryopreservation of pre-implantation embryos or spermatozoa is a common approach for protecting these lines from being lost or to store them in a repository. A mutant line can be taken out of a breeding nucleus only if sufficient numbers of samples with an appropriate level of quality are cryopreserved. The quality of different donors within the same mouse line might be heterogeneous and the cryopreservation procedure might also be error-prone. However, only limited amounts of material are available for analysis. To improve the monitoring of frozen/thawed spermatozoa, commonly used in vitro fertilization (IVF) followed by embryo transfer were replaced with animal-free techniques. Major factors for assessing spermatozoa quality (i.e., density, viability, motility, and morphology) were evaluated by fluorescence microscopy. For this, a live/dead cell staining protocol requiring only small amounts of material was created. Membrane integrity was then examined as major parameter closely correlated with successful IVF. These complex analyses allow us to monitor frozen/thawed spermatozoa from GM mice using a relatively simple staining procedure. This approach leads to a reduction of animal experiments and contributes to the 3R principles (replacement, reduction and refinement of animal experiments).  相似文献   
104.
Observations on six farms keeping laying hens in furnished cages showed that hens accepted the installations of this new housing type. Behaviours indicating that the adaptations of hens were problematic have not been observed. Locomotion and dust bathing in some groups occured as not sufficient. Lighting was too low and affected expressions of behaviour patterns. For further developments are proposed more usable space per bird and a different placement of perches. Dust bathes should be utilized permanently and should contain sufficient amount of litter.  相似文献   
105.
The aim of the present study was to provide current data on the prevalence of anti-Yersinia-antibodies in Bavarian slaughtering pigs. The recomBlot Westernblot assay based on five recombinantly produced Yersinia Outer Proteins (YopD, YopE, YopH, YopM, V-antigen) is well evaluated for the use in the diagnosis of human yersiniosis and proved to be also a valuable tool for the detection of porcine antibodies. 965 out of 1002 meat juice samples collected in 53 Bavarian pig farms contained anti-Yop/V-Ag-antibodies. Only blots with three or more detectable signals were considered as positive. On the basis of these results a possible previous history of Yersinia infection was detected in 45.4% of the pigs and all of the pig farms. The high prevalence of anti-Yersinia-antibodies found in this investigation demonstrates the need for further epidemiological surveillance and animal studies to assess consumers' endangering.  相似文献   
106.
The aim of this study was to examine the incidence of sperm agglutinations and their relationships with sperm quality and fertility. Semen samples of 40 boars of an AI-station were investigated. Nineteen of the 40 investigated boars showed a constantly low (< 10% agglutinated sperm), 3 an intermediate (10-20%) and 6 boars a high level (> 20%) of agglutination in raw semen. The degree of agglutination in sperm samples of 12 boars varied distinctly during the investigation period. During summer more (P < 0.05) agglutinated sperm were observed (11.0 +/- 11.6%) than during winter (6.2 +/- 7.3%). There was no association between bacterial contamination and incidence of agglutinations (P > 0.05). After dilution in extender the percentage of agglutinated sperm decreased from 6.2 +/- 7.3% to 1.1 +/- 1.4% (P < 0.0001). Twenty-four hours after dilution the percentage of progressively motile sperm was 7.4% lower (P < 0.05) in ejaculates with an initially high degree of agglutination (> 20% agglutinated sperm) compared to samples with an initially low degree of agglutinated sperm (< 10%). Plasma membrane integrity, mitochondrial membrane potential, acrosome reaction and chromatin structure were independent (P > 0.05) from the level of agglutination. Fertility data did not differ (P > 0.05) between boars with low and high numbers of agglutinated sperm in raw semen. The results show that there are individual, ejaculatory and seasonal variations in the incidence and degree of agglutination. Agglutinations have a negative effect on motility of sperm and disappear to a large extent after dilution in sperm extender. They have no negative consequences on fertility.  相似文献   
107.
The aim of this study was to investigate the prevalence of antibodies against zoonotic agents in employees of the zoological garden of Vienna, Sch?nbrunn, Austria. Sixty out of 120 employees participated in the study. In 97% of them antibodies to at least one zoonotic agent were identified. Only two participants were free of antibodies to the zoonotic agents tested. The following seroprevalences (in brackets) were obtained: Viral zoonotic (and potentially zoonotic) agents: Influenzavirus A/H1N1 (58%), Influenzavirus A/H3N2 (85%), Lymphocytic choriomeningitis virus (13%), Encephalomyocarditis virus (5%), Orthopox- (Cowpox-) virus and Hantavirus type Puumala (3%). Hantavirus type Hantaan and Borna disease virus (all negative). Bacterial zoonotic agents: Bartonella henselae (65 %), Borrelia burgdorferi (10%), Leptospira interrogans serovar copenhageni and serovar icterohaemorrhagiae as well as Chlamydophila psittoci (2% each). Brucella spp., Coxiella bumetii, and Francisella tularensis (all negative). Parasitic zoonotic agents: Toxoplasma gondii (53%), Toxocara spp. (21%), Capillaria hepatica (2%), Fasciola hepatica, Schistosoma mansoni, E. multilocularis, and E. granulosus (all negative). The remarkably high seroprevalence to the causative agent of cat scratch disease, Bartonella henselae, is probably due to the private contact of the employees to cats. Regarding viral zoonotic agents it has to be mentioned that Influenzavirus vaccination and/or human-to-human transmission of especially A/H3N2 Influenzaviruses probably attributed significantly to the very high seroprevalence to both Influenzavirus types A/H1N1 and A/H3N2. When investigating parasitic zoonotic agents, high prevalence rates were found against Toxoplasma gondii and Toxocara spp., however, it was not possible to establish a causal link between seropositivity and the professional activity in the zoo. Interestingly, in the case of antibodies to T. gondii, the typical correlation with age was not found in this study, while in the case of the Toxocara spp. positive subjects a correlation was identified with both age and duration of employment in the zoo. Regarding the later two zoonotic parasites, employees of the zoological garden showed significantly higher seroprevalences than the average Austrian population. Antibodies to Capillaria hepatica, a hepatic-parasite in rodents which is diagnosed in humans rarely, were identified in one employee and another one showed a questionable positive result. Further investigations did not exhibit clinical infestations with the parasite in these two individuals so far.  相似文献   
108.
The present study examined the effects of race and age on the redox potential behavior of blood plasma samples. The oxidative stability was studied in the reaction with p-benzoquinone. The investigated animals represented three different cattle races (Limousin, Angus and Hereford), grazed on pasture. The blood samples from clinical healthy heifers (44) and calves (45) were investigated. The following parameters were determined: the start level of redox potential and the level after adding 10, 20, and 30 mg p-benzoquinone to the samples. The analyses of the redox potentials showed the advantage of oxidative stability of heifers compared with calves. The results showed a significant effect of race on the redox potential behavior of blood plasma.  相似文献   
109.
Fluotrimazole [BUE 0620; 1-(3-trifluoromethyltriphenyl) 1,2,4-triazole] (20 μg/ml of nutrient solution) and clotrimazole [Bay b 5097; bisphenyl(2-chlorophenyl)-1-imidazolyl methane] (5 μg/ml) did not inhibit dry weight increase and only slightly reduced multiplication of sporidia of Ustilago avenae during the first doubling period (about 4 hr). After 8 hr, both fluotrimazole and clotrimazole more strongly inhibited sporidia multiplication than dry weight increase. As a consequence of treatment with both fungicides the usually single-celled sporidia appear swollen, multicellular, and branched. Both chemicals at a concentration range of 5–100 μg/ml did not affect oxidation of glucose. The effect of fluotrimazole and clotrimazole on protein, DNA, and RNA synthesis was similar to that on dry weight. Following a 6-hr incubation period total lipid synthesis was quantitatively unaffected by both chemicals. As the analysis of major fatty acids of total lipids revealed fluotrimazole substantially induced the synthesis of 20:4 carbon fatty acids, while in clotrimazole-treated sporidia the pattern of fatty acids did not differ from that of control sporidia. Fluotrimazole and clotrimazole produced a higher quantity of free fatty acids in sporidia of U. avenae. Gas-liquid chromatographic analysis of sterol fractions in treated and control sporidia (6 hr) indicated that both fluotrimazole and clotrimazole seriously inhibited ergosterol biosynthesis and concomitantly caused an accumulation of immediate ergosterol precursors which represent C-4-methyl and 4,4-dimethyl sterols. Incorporation of [14C]acetate for 2 hr into various lipid fractions of sporidia of U. avenae also revealed that radioactivity in C-4-desmethyl sterols in both fluotrimazole- and clotrimazole-treated sporidia was drastically reduced, while the radioactivity of C-4-methyl and 4,4-dimethyl sterols distinctly increased. The data suggest that fluotrimazole and clotrimazole are specific inhibitors of the oxidative demethylation of the C-14-methyl group during ergosterol biosynthesis in U. avenae.  相似文献   
110.
In the present study variability of bull sperm concerning percentages of sperm with intact plasma membranes (PMI), high mitochondrial membrane potential (HMMP) and positive acrosomal status (PAS) before and after cryopreservation (vKK; nKK) between bulls and between ejaculates within bulls was examined. Studies were performed on 4 semen samples each of 20 Deutsche Fleckvieh bulls. VKK-Values were 76.5% +/- 9.6% (PMI) 68.3% +/- 8.9% (HMMP) and 9.8 +/- 5.1% (PAS) and nKK-values were 38.1 +/- 14.0% (PMI), 38.2 +/- 14.0% (HMMP) and 30.9 +/- 12.1% (PAS). After freezing, variabilities in sperm parameter values between bulls (nKK: PMI: 49.8%, HMMP 52.1% and PAS: 56.6%) were nearly quite as high or higher than variabilities between ejaculates (nKK: 50.2%, 47.9% and 43.4%). VKK-values of PMI, HMMP and PAS were only fairly to moderately related (0.36 < r < 0.53; P < 0.05) to nKK-values. The results show that PMI, HMMP and PAS did not only vary between bulls, but also between ejaculates within bulls. As there are no high relationships in these sperm parameters between times before and after cryopreservation, each ejaculate should be examined after cryopreservation in order to receive a reliable information about the quality of cryopreserved sperm.  相似文献   
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