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91.
92.
Within the field of restorative environments research, it is commonly assumed that restorative responses, triggered by exposure to natural elements and settings, are ultimately adaptive traits originating from our species’ long evolutionary history in natural environments. The aim of this article is to critically investigate the viability of this evolutionary view on restoration. In doing so, we specifically focus on Stress Recovery Theory (SRT), as this theoretical framework has most extensively elaborated on the supposed evolutionary origins of restoration. A detailed analysis of SRT's psycho-evolutionary framework shows that neither current empirical evidence nor conceptual arguments provide any strong support for the hypothesis of restorative responses to nature as an ancient evolved adaptive trait. Based on this conclusion we put forward an alternative model for restorative responses to nature based on processing fluency, which prima facie circumvents some of the pitfalls associated with evolutionary accounts for restoration. The Discussion section reflects on the implications of our critical discussion for the theory and practice of urban forestry and urban greening.  相似文献   
93.
Methane (CH4) emissions from rice paddies often show significant diurnal variations, most likely driven by diurnal changes of radiation and temperature in air, floodwater, and soil. Field measurements, however, are often scheduled at a fixed time of a given measuring day, thereby neglecting sub‐daily variations of CH4 emissions. Here we evaluated diurnal patterns of CH4 emissions from traditional paddy rice production as observed during field measurements in the Philippines. Field emissions were measured during three consecutive cropping seasons using an automated chamber and gas sampling system with fluxes being obtained every 4 h. Methane fluxes were monitored with a total of nine chambers during the dry seasons in 2012 and 2013 and 27 chambers during the wet season in 2012. Significant and consistent diurnal patterns of CH4 emissions were mainly observed from the start of field flooding until the middle of cropping periods, i.e., periods with low leaf area of the rice crop. Our data show that disregarding the diurnal variability of fluxes results in an average overestimation of seasonal CH4 emissions of 22% (16–31%) if measurements were conducted only around noon. Scheduling manual sampling either at early morning (7:00–9:00) or evening (17:00–19:00) results in estimations of seasonal emissions within 94–101% of the “true” value as calculated from multiple daily flux measurements. Alternatively, uncertainties of seasonal emissions can be reduced to an average of ≤3% by applying sinus function or Gauss function‐based correction factors. Application of correction factors allows the performance of flux measurements at any time of day. We also investigated N2O emissions from rice paddies with respect to diurnal variations, but did not find, as in the case of CH4, any significant and persistent diurnal pattern.  相似文献   
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Faecal contamination on lettuce growing in the open as indicated by the presence of Escherichia coli I was demonstrated for up to 21 days after irrigation with sewage effluent, although the level of contamination usually decreased after 3–7 days. Recovery of other coliform bacteria gave parallel results ; counts of these organisms and of other bacteria also indicated the persistence of more general pollution.  相似文献   
96.
Blood, feces, and nasal swabs specimens were collected 12 to 24 hours after birth and then 3 times/week (blood only once per week) from one group of 10 calves until they were 10 weeks old and from a second group of 10 calves until they were 10 to 20 weeks old. Colostrum was collected from all calves' dams and tears from 5 randomly selected calves in the first group. All fecal and nasal specimens were assayed for bovine coronavirus (BCV) antigens by ELISA. Nasal epithelial cells were examined for BCV antigens by direct immunofluorescence. Isotype antibody titers to BCV in all samples from 5 calves in group 1 were evaluated by ELISA. Zinc sulfate turbidity (ZST) values were determined on the first serum samples taken from all calves in group 1. To determine whether any correlation existed between ZST values, isotype antibody titers to BCV (12 to 24 hours after birth), number of respiratory sick days, number of enteric sick days, or days to first shedding of virus, a Spearman rank order correlation coefficient was done. Bovine coronavirus respiratory tract and enteric tract infections were common on this farm. Most initial infections developed when calves were 1 to 3 weeks old; however, there were also multiple incidences of shedding of viral antigens or seroconversions at later times during the study. Persistence of infection or reinfection of the upper respiratory tract with BCV was common. Colostral antibody titers to BCV (IgG1) were in all cows at moderate amounts; however, calf serum antibody titers and ZST values (12 to 24 hours after birth) were highly variable.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
97.
The enteropathogenicity of avian reoviruses (ARVs), isolated from chickens affected with malabsorption syndrome (MAS) from The Netherlands and Germany was studied. In the first trial seven different ARVs isolated from MAS cases were inoculated in 1-day-old specific pathogenic free (SPF) white leghorns. The pathogenicity was compared with 2 ARVs isolated from cases of tenosynovitis, namely reference strain S1133 and a Dutch strain. Although a difference in the severity of the clinical disease was observed, all reoviruses could induce vacuolar degeneration and sloughing of the epithelium of the small intestine at day 2 post inoculation (PI) till day 7 PI. Two Dutch and one German ARV derived from MAS causing the most severe intestinal lesions at day 2 PI, were further studied in the second trial using SPF broilers. These reoviruses did not cause weight gain depression in the broilers although lesions in the small intestine were present from day 1 up to day 4 PI and were more severe than in the white leghorn chickens. In one of the inoculated groups apical denuded villi were already present at day 1 PI. At day 7 PI the small intestine of the infected broilers appeared to be normal. Reovirus antigen was detected in the cytoplasm of the enterocytes at the tip and middle section of the affected villi both in layers and in broilers. To study the role of intestinal CD4+ and CD8+ T-cells and macrophages/monocytes in the pathogenesis of ARV, the numbers of these cells of the jejunal villi of one infected and the control broiler groups were compared. CD4+ T-cells were detected in low numbers and only in the infected broiler group at day 14 PI. The numbers of CD8+ T-cells and macrophages/monocytes were significantly higher in the infected broiler group than in the control broiler group at day 7 and 14 PI and at day 7 PI respectively. Our study indicates that the reovirus alone cannot induce intestinal lesions as found in MAS chickens. Moreover, CD8+ T-cells may play a major role in the pathogenesis and or reovirus clearance in the small intestine.  相似文献   
98.
The absorption of ethanol from the rumen was studied in three British Milk sheep equipped with a rumen cannula. After removal of the rumen content and washing the forestomachs several times the reticulo-omasal orifice was closed and through the cannula 20 or 60 ml ethanol and 2 ml Cr-EDTA were infused in physiological saline. The entire fluid volume was 3000 ml. At the start of the experiment (0 min) and subsequently in the 5th, 15th, 30th, 45th, 60th and 75th minutes samples were taken from the fluid present in the forestomachs. During the 75-min experiment the amount of ethanol gradually decreased in the rumen. The rate of disappearance varied according to concentration. The graph depicting the change of ruminal ethanol concentration shows a curve typical of passive transport. The equation describing the disappearance of ethanol was y = -0.0474x2 + 5.6544x + 10.869 after the administration of 20 ml ethanol, and y = -0.1377x2 + 19.541x - 24.606 after the infusion of 60 ml ethanol. It was established that ethanol was absorbed through the rumen wall by a passive transport process.  相似文献   
99.
100.
Egg expulsion and post mortem examination were used to compare self-cure and resistance to reinfection with Haemonchus contortus in female Merino sheep, AA and BB hemoglobin types. Animals were infected by 500 or 5000 larvae of H. concortus once, or several times, before being challenged by 500 (low dose) or 5000 (high dose) larvae.In AA sheep infected once by 500 larvae self-cure was detected by a challenge of either 500 or 5000 larvae while in multi-infected sheep only a challenge of 5000 L3 induced the self-cure. In BB sheep a mild self-cure was detected only by a challenge of 5000 larvae.In AA sheep receiving several infections, challenge by 500 larvae was not effective in producing resistance while 5000 L3 was effective in producing a state of resistance for up to 35 days post challenge.At post mortem examination, a strong state of resistance was evidenced in multi-infected animals by the low number of L4 and adults present in the abomasum up to the 35th day after challenge.In BB sheep no state of resistance was demonstrated by challenge with either 500 or 5000 L3, even in multi-infected animals.  相似文献   
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