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101.
Aursand IG Gallart-Jornet L Erikson U Axelson DE Rustad T 《Journal of agricultural and food chemistry》2008,56(15):6252-6260
Low-field (LF) (1)H NMR T 2 relaxation measurements were used to study changes in water distribution in lean (Atlantic cod) and fatty (Atlantic salmon) fish during salting in 15% NaCl and 25% NaCl brines. The NMR data were treated by PCA, continuous distribution analysis, and biexponential fitting and compared with physicochemical data. Two main water pools were observed in unsalted fish, T 21, with relaxation times in the range 20-100 ms, and T 22, with relaxation times in the range 100-300 ms. Pronounced changes in T 2 relaxation data were observed during salting, revealing changes in the water properties. Salting in 15% brine lead to a shift toward longer relaxation times, reflecting increased water mobility, whereas, salting in saturated brines had the opposite effect. Water mobility changes were observed earlier in the salting process for cod compared to salmon. Good linear correlations ( F = 0.05) were found between T 2 parameters and water holding capacity, centrifugation loss, water activity, and salt content in the liquid phase for all fish groups. Fillet pH and total weight changes correlated linearly with T 2 parameters for some of the fish groups. 相似文献
102.
Background, Aims, and Scope As a consequence of human living and activity, water infiltration to the urban subsurface occurs from a variety of different
sources, like precipitation, irrigation, leaking pipes and sewers, septic tanks and rainwater infiltration ponds. This infiltration
is strongly related with quality issues of the infiltrated water and further impact on groundwater quality. In order to set
up an integrated urban water balance it becomes essential to estimate the infiltration processes, i.e. water flow and solute
transport, from these different infiltration sources and to take into account the large spatial variability of sediment properties,
the geometric settings of these sources and the groundwater table. For that purpose, the development of simple, physically-based
quantification approaches is required in order to establish an efficiently working prediction and risk analysis tool within
the framework of an integrated urban water management system. The scope of the presented work was to demonstrate the applicability
of the developed approaches at urban scale.
Methods Since a detailed, three-dimensional, numerical quantification of the infiltration processes within the entire urban area is
not possible, the individual sources were considered as independent within the EU AISUWRS project. Different models were developed
for balancing infiltration from areal and point sources with respect to the related flow pattern. The analytical model UL_FLOW,
based on one-dimensional, steady state analytical solutions, allows the estimation of conservative tracer residence times
in layered sediments under varying infiltration rates. The numerical model WSTM, based on a three-dimensional random walk
approach, calculates water and solute transport from pipe leaks. Additionally, the sources were classified in accordance to
the spatial distribution of the parameters determining the infiltration processes.
Results UL_FLOW was applied to data sets from the city of Rastatt within a case study of the AISUWRS project. Each neighbourhood of
water balance computation by the Urban Volume and Quality Model (UVQ) was defined as an areal infiltration source with unique
parameter values for sediment depth, profile and properties, as well as infiltration rate time series. Groundwater recharge
and residence time series were computed for each neighbourhood. Relevant statistical parameters obtained by time series analyses
from those time series could be mapped by GIS. Point infiltration, particularly from sewers, was classified due to the sediment
parameters and the distance to the groundwater table at each source location in order to reduce computational efforts. WSTM
computations provided time series of groundwater recharge and tracer breakthrough for some specific cases.
Discussion The analytical model UL_FLOW provides fast and efficient computation of groundwater recharge and residence times accounting
for storage effects within the unsaturated zone of urban areas. The reliability of this model has been shown by cross validation
with HYDRUS1D. Because of the high computational effort, WSTM could provide only short-term simulations for some specific
parameter sets for which residence time estimates could be derived.
Conclusions UL_FLOW provides an analytical modelling tool for balancing one-dimensional areal infiltration and estimating residence times
under varying conditions including spatial parameter variability. These balances could be used for assessing the impact of
those infiltration sources on groundwater quality. The tracer breakthrough from point infiltration sources computed by WSTM
could also be used for such kinds of assessment. The larger spatial parameter variability associated with these sources could
be handled by classification in GIS environments.
Recommendations and Perspectives Similar to the areal sources, a simple balance approach for point sources based on analytical solutions needs to be developed
for estimating residence times in order to avoid large computational efforts. Such a model would complete the balancing of
all kinds of infiltration sources in urban areas efficiently. Since the approaches are based on the balance of the physical
processes, they have a large predictive capability and could be included into an integrated urban water balance and management
system. The mapping of the statistical values of the residence times provides a tool to compare parts of the urban areas and
to visualize differences between urban water management scenarios. 相似文献
103.
The present study aimed at describing older persons’ experiences of outdoor environments at nursing homes in Sweden in terms of what factors are important and in what way they are important. Twelve residents and seven next of kin from three nursing homes participated in 16 interviews. Two main themes were identified. The first theme, access to nature and surrounding life, describes the outdoor environment as a means for change and as promoting a feeling of freedom. This theme calls for an inspiring design. The second theme, being comfortable in the outdoor environment, describes how important it is that going outdoors can be something easy and natural, and it calls for a comfortable design. The results are intended to facilitate practical knowledge that is useful to planners, decision-makers and care workers striving to create attractive and useable environments that are part of the daily life of nursing home residents. The themes also exemplify how the outdoor environment at nursing homes can serve as a resource in promoting restoration, a feeling of being at home and positive development late in life. 相似文献
104.
105.
Juhani Hakkarainen Paul Lindberg Gsta Bengtsson Lennart Jnsson 《Acta veterinaria Scandinavica》1978,19(2):269-284
Blood serum glutathione peroxidase activity and blood selenium concentration were measured in blood samples from pigs subjected to experimentally induced selenium deficiency and dietary selenium supplementation on graded levels. A highly significant correlation between blood selenium and serum GSH-Px activity in pigs, especially in selenium deficient pigs, was demonstrated. There was also a strong relationship between blood selenium concentration and serum GSH-Px activity in pigs receiving dietary selenium at graded levels. Serum GSH-Px activity exhibited an excellent close-response relationship to dietary selenium. Linear regression analysis showed that the increased serum GSH-Px activity was a function of the dietary selenium concentration. The fitness of serum in monitoring slight changes of the selenium status of pigs with help of the estimation of GSH-Px activity was discussed. The measurement of serum GSH-Px activity seems to provide a useful and rapid means for defining selenium requirements and for identifying selenium deficiency in growing pigs. 相似文献
106.
J Luthman V Dall S O Jacobsson B Bengtsson C Korpe 《Acta veterinaria Scandinavica》1988,29(2):199-206
The addition of citrate buffer to a penicillin G preparation for injection was in a preliminary study found to improve the local tolerance in rabbits. In the present study 2 penicillin G preparations with different citrate buffer content was tested in the target species swine and cattle. The results of the local tolerance studies indicated that the preparation with the highest citrate content caused less tissue damage. In swine this preparation gave 100% higher maximum levels in serum than the more tissue irritating preparation. In calves the most irritating preparation showed significantly longer half-life. The results indicated that the local tolerance may influence the serum levels in a way that may influence the penetration of penicillin. 相似文献
107.
Olsén L Bondesson U Broström H Tjälve H Ingvast-Larsson C 《Veterinary journal (London, England : 1997)》2008,177(2):242-249
The pharmacokinetics of the histamine H(1)-antagonist cetirizine and its effect on histamine-induced cutaneous wheal formation were studied in six healthy horses following repeated oral administration. After three consecutive administrations of cetirizine (0.2 mg/kg body weight, bw) every 12h, the trough plasma concentration of cetirizine was 16+/-4 ng/mL (mean+/-SD) and the wheal formation was inhibited by 45+/-23%. After four additional administrations of cetirizine (0.4 mg/kg bw) every 12 h, the trough plasma concentration was 48+/-15 ng/mL and the wheal formation was inhibited by 68+/-11%. The terminal half-life was about 5.8 h. A pharmacokinetic/pharmacodynamic link model showed that the maximal inhibition of wheal formation was about 95% and the EC(50) about 18 ng/mL. It is concluded that cetirizine in doses of 0.2-0.4 mg/kg bw administered at 12 h intervals exhibits favourable pharmacokinetic and pharmacodynamic properties without causing visible side effects, and the drug may therefore be a useful antihistamine in equine medicine. 相似文献
108.
109.
110.
Sidsel Fiskaa Hagen Grethe Iren A. Borge Knut Asbjørn Solhaug Gunnar B. Bengtsson 《Postharvest Biology and Technology》2009,51(1):36-42
In this study, curly kale stored at 1 °C for 3 and 6 weeks was compared with plants remaining in the field regarding several properties related to human health and sensory quality. Cold storage had no effect on the antioxidant capacity (ORAC assay), total phenols (Folin-Ciocalteu assay) or flavonol content, but reduced the content of vitamin C and soluble sugars. The ratio ascorbic:dehydroascorbic acid decreased from about 3 to 0.5 upon storage. The largest changes in the content of bioactive compounds were found in plants that remained in the field for 6 additional weeks, including many frost days. In these plants, the levels of flavonols, total phenols and antioxidant capacity were reduced by 25–35% and the vitamin C content by more than 50%, whereas soluble sugars and dry matter increased by roughly 20% and 30%, respectively. Among all the curly kale samples, the antioxidant capacity was positively correlated with the level of total phenols (r = 0.73, P < 0.001) and total flavonols (r = 0.70, P < 0.001). Values obtained with a non-destructive method based on chlorophyll fluorescence (ChlF) were well correlated with the flavonol content in the leaves, with the highest correlation found for quercetin (r = 0.76, P < 0.001). Using the ChlF method, the kinetics of the flavonol content during the experiment was recorded. The same method also showed gradients of flavonol content within the plant, with the highest values in the upper leaves and in the tip of the leaves. ChlF measurement, therefore, proved to be a quick and cost-effective alternative to chemical analyses of the flavonol content in curly kale. 相似文献