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1.
Loess hilly and     
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2.
AIM: To observe the effect of immune-activated platelets and low-density lipoprotein cholesterol (LDL) on the expression and activity of cyclooxygenase-2 (COX-2) and peroxisome proliferator activated receptor α (PPAR-α) in human umbilical vein endothelial cells (HUVECs) treated with activated platelets and LDL. METHODS: The platelets were activated by ADP. The co-culture system of HUVECs with immune activated platelets and/or LDL were established. The activity of COX-2 and expression of PPAR-α at mRNA and protein levels in HUVECs were detected by RT-PCR and Western blotting. The concentration of PGE2 was measured by ELISA for representing the COX-2 activity. The PPAR-α activity was determined by a nuclear factor assay kit. RESULTS: The COX-2 activity and mRNA expression of PPAR-α, the protein levels of COX-2 and PPAR-α and PGE2 concentration in activated platelets group were significant higher than those in un-activated platelets group (all P<0.01). No difference of PPAR-α binding activity was observed between two groups. LDL didnt affect the COX-2 activity and PPAR-α expression, but significantly promoted the stimulating effect of immune-activated platelets. CONCLUSION: Immune-activated platelets significantly promote COX-2 activity and PPAR-α expression in HUVECs, but dont change the PPAR-α binding activity. LDL at general concentration does not affect the expression and activity of COX-2 and PPAR-α, but promote the effect of activated platelets on HUVECs.  相似文献   

3.
Fruit body , basidiospore and mycelialmorphology ,and the structure of the ectomy-corrhiza formed with the host plant , arei mportant characteristics for identifying variouskinds of ectomycorrhizal fungi . AGERER[1]described the microstructure of ectomycorrhizaformed byPiceirhiza internicrassihyphisandPicea abiesas thick-walled hyphae in themycelial mantle , some of which grew inparallel . WANGet al[2 ,3]studied structuresdissected from ectomycorrhizae ofBoletusedulis,Tricholoma matsutakea…  相似文献   

4.
Summary

Shade and chemical thinning treatments were applied to mature ‘Royal Gala’/M.26 apple trees either alone or in combination to study their effects on the pattern of abscission and growth of spur fruit. Natural fruit drop occurred in two distinct waves in both years; the first wave peaked 20 d after bloom (DAB) at a weekly abscission rate of c 15% in both years. The second wave of fruit drop in 2001 occurred earlier and was more intense than in the previous season. Application of NAA as a bloom thinner increased the maximum weekly abscission rate during the first wave of fruit drop in both years. Chemical fruit thinning treatments (Carbaryl in 2000, BA or delayed lime sulphur in 2001) had no effect on abscission or growth of spur fruit. Covering trees with 80% shade cloth for 3 d (2000) or 5 d (2001) stimulated a wave of fruit abscission that peaked c 10–15 d after removal of the cloth. Shade during the period from 20–25 DAB stimulated more fruit drop than earlier shade treatments, resulting in weekly abscission rates as high as 70%.There were no additive effects of combining thinning chemicals and shade treatments on abscission of fruit from spurs. However, additive effects of shade and thinning treatments were observed when measured as whole-tree crop density values, indicating that abscission of fruit from one-year wood was stimulated when low light conditions preceded application of (fruit) thinning chemicals. Shading trees from 34–39 DAB in 2000 resulted in a transient reduction and subsequent increase in the rate of dry-matter accumulation in fruit that were retained. Considerable challenges lie ahead in developing models of fruit growth that can account for the inter-dependent effects of light and crop load on fruit abscission and development that exist within an orchard environment.  相似文献   

5.
Urban trees provide numerous ecosystem goods and services by providing shade, habitat for wildlife, removal of air pollutants and the removal and storage of atmospheric CO2. Carbon removal services provided by Canadian urban trees have previously been assessed using an IPCC 2006 guidelines approach based on the percentage of urban area covered by tree canopy (UTC) for the 2012 time period (Pasher et al., 2014). That work however provided only a single point in time assessment of the national scale UTC and carbon removal services. The research undertaken for this study was a continuation of this earlier work focusing on a 1990 national scale UTC assessment and carbon sequestration estimates for 1990. UTC estimates for 1990 were developed using a point sampling approach with circa 1990 air photos covering a large portion of Canadian urban areas. In total almost 179,000 points were sampled for the 1990 time period, reassessing 83% of the points used for the previous 2012 assessment. Based on the urban area boundary layers for 1991 and 2011, Canada’s urban areas grew by an estimated 6% for this time period. Most of this growth occurred through conversion of agricultural and forested lands to urban. At the national scale the UTC for 1990 was estimated to be 27.6%, as compared to the 2012 UTC estimate of 26.1%, the difference between estimates for the two time periods fell within the uncertainty range. Carbon removal estimates based on the UTC estimates were also very similar for the two dates with 660.2 kt C removed in 1990 and 662.8 kt C removed in 2012. It was noted that urban development in the Prairie regions resulted in an increase in tree cover as compared to the pre-conversion agricultural and natural landscapes and also that in most urban areas across the country UTC increases through time as tree cover matured in newly developed urban areas. These two assessments provide a time series of urban trees for 22 year time period, which will be useful for further studies and analysis.  相似文献   

6.
Urban environments are often characterized by extensive paved surfaces, exacerbating the urban heat island effect. At the same time, limited root space due to underground infrastructure poses a challenge for planting new trees in these areas. Trees in planters have emerged as popular design elements, offering innovative and sustainable greening solutions, particularly in urban environments with limited rooting space. However, growing conditions in planters may strongly impact tree growth and the provision of environmental ecosystem services (ES). In this 3-year study, we analyzed tree growth and ecosystem services (cooling by shading, CO2-fixation) of London plane (Platanus x hispanica Münchh.) and small-leaved lime (Tilia cordata Mill.) in four planting treatments: in-ground (G), planters in the ground (PG), non-insulated plastic planters (P), and insulated planters (PI). We also recorded soil temperature throughout the experiment and implemented soil drought conditions by reducing soil irrigation for half of the trees after one year. Our findings revealed higher thermal fluctuations in soil temperature within non-insulated plastic planters (P), reaching a maximum of 45 °C, surpassing the critical temperature threshold for plant growth (>38 °C). In contrast, insulated planters (PI) effectively mitigated soil temperatures, staying below 33.8 °C. When planted in the ground (G), P. x hispanica exhibited a significantly higher stem diameter increment (52–66%) compared to other planting treatments, aligning with the provision of ecosystem services. However, T. cordata trees showed a more moderate response to planting treatments in terms of growth and ecosystem service provision. Furthermore, the implementation of soil drought conditions resulted in a reduction of up to 34% in stem diameter increment for P. x hispanica and up to 25% for T. cordata. Our results underscore the necessity of tree species-specific knowledge about growth responses to different planting treatments for effective urban planning perspectives, as the provision of ecosystem services may be influenced differently.  相似文献   

7.
Landscape sustainability can be considered in terms of order and disorder, where order implies causality, well-defined boundaries and predictable outcomes, while disorder implies uncertain causality, shifting boundaries and often-unpredictable outcomes. We address the interplay of order and disorder in social–ecological landscapes (SELs) using spatiotemporal analysis of entropy-related indices of Normalized Difference Vegetation Index time-series. These indices can provide insights for complex systems analysis for the evaluation of adaptive capacity in SELs. In particular, our overarching aim is to help interpret what an increase of order/disorder means with regards to SELs and the underlying drivers and causes of conditions in SELs. The approach can be used to increase spatially explicit anticipatory capability in environmental science and natural resource management based on how the system has responded to stress in the past. Such capability is crucial to address SEL adaptive capacity and for sustainable planning given that surprises may increase as a consequence of both climate change and multiple interacting anthropogenic stressors. These advancements should greatly contribute to the application of spatial resilience strategies in general, and to sustainable landscape planning in particular, and for the spatially explicit adaptive comanagement of ecosystem services.  相似文献   

8.
Summary

Total anti-oxidant capacity (TAC) and the contents of mono- and disaccharides, and organic acids were determined in strawberry fruit from ten genotypes sampled from eight experimental sites in Norway in 2002 and 2003. The difference between genotypes was significant for all recorded traits, and it appeared possible to select for all traits in breeding programmes. On average, the Norwegian bred cultivar ‘Carmen’ had a TAC of 30.07 mmol kg–1 fresh weight (FW), compared to 23.16 mmol kg–1 FW in the standard cultivar ‘Korona’. TAC was negatively correlated with fruit size, rainfall and leaf surface humidity, but was positively correlated with the minimum temperature on the day prior to sampling. Mono- and di-saccharide contents were negatively correlated with both minimum and maximum temperatures, and with wind velocity. It was confirmed that the sugars:organic acids ratio was inversely related to the maximum temperature on the day before harvest, which supports anecdotal claims that strawberries grown in northern areas have, on average, better flavour.  相似文献   

9.
10.
Different organic solvents (petroleum ether, ethyl acetate and ethanol) were used to extract A. aegerita mycelium and spent culture medium following growth of the fungus in submerged culture. All the extracts exhibited antioxidant and anti-tumor activity that may be linked to triterpenoids present in the extracts.  相似文献   

11.
The effects of three intensities of pruning on fruit set, fruit bud development, cropping and vigour of intensively grown Cornice and Beurré Hardy pears were compared over a three-year period. Severe pruning, in which extension shoots were cut back to fruit buds on the two-year-old wood, greatly increased the set of fruits per 100 flower clusters and reduced vigour, in comparison with a renewal type of pruning. Severe pruning of Comice caused a relative reduction in the number of fruit buds in subsequent years, so the improvement in fruit set did not lead to an increase in crop per tree, but with Beurré Hardy fruit bud formation was unaffected and the crop per tree was increased by hard pruning. There was an improvement in yield in relation to tree size with both varieties. Pruning to fruit buds provides a means of increasing yields per acre by ‘containing’ pear trees at close spacings without reducing the yield per tree.

Partial disbudding just before blossoming increased fruit set but not enough to offset the reduction in number of fruit buds. Supplementary pollination did not improve the yields of Comice and increased the crop of Hardy in one year only.  相似文献   

12.
《Scientia Horticulturae》2001,87(1-2):93-105
Campanula carpatica Jacq. ‘Blue Clips’ plants were grown in a greenhouse under nine combinations of day and night temperatures created by moving plants every 12 h among three day/night temperatures (15, 20, and 25°C). At each temperature, there were three daily light integrals (DLI; 4.2, 10.8, and 15.8 mol m−2 per day, averaged over the experimental period) created with varying supplemental light, and ambient (≈400 μmol mol−1) and enriched (≈600 μmol mol−1) CO2 concentrations. Time to flower was closely related to average daily temperature (ADT), and was not significantly affected by the day or night temperatures delivered to achieve a specific ADT. Time to flower was not largely affected by DLI or CO2 enrichment. As plant ADT increased between 15 and 25°C, flower diameter decreased about 1 mm per degree and was not related to the difference between day and night temperatures (DIF). Flower diameter was smallest and least sensitive to changes in temperature at lower DLI and at ambient CO2 levels. There were 10 less flower buds and 0.3 g less dry mass per plant at first flower for every 1° increase in plant ADT at high and medium DLIs. Flower bud number and dry mass were relatively low and less sensitive to changes in ADT at low DLI, and increased slightly with CO2 enrichment at medium and high but not at low DLI. Plant height was not related to ADT, but increased linearly as DIF increased from −6 to 12°C at all DLIs, but the response was stronger under low DLI than high and medium DLIs. Flower bud number and dry mass were correlated closely with the ratio of DLI to daily thermal time (base temperature of 0°C). Flower bud number and dry mass were highest when C. carpatica plants were grown at 15°C with a DLI of 10–15 mol m−2 per day.  相似文献   

13.
AIM: To investigate the gene polymorphisms of interferon-γ(IFN-γ) and interleukin-4(IL-4) and the association with asthmatic susceptibility and the levels of plasma IFN-γ, IL-4 and IgE of asthmatic children. METHODS: 100 asthmatic children and 122 control children were enrolled the study. The genotypes of IFN-γ gene-179G/T polymorphism, IL-4 gene-33C/T and-589C/T polymorphisms were tested by PCR-RFLP.The genotype of IFN-γ gene +874A/T polymorphism was tested by AS-PCR.The CA repeat polymorphism of IFN-γ gene was detected by capillary electrophoresis technique.The levels of serum IFN-γ, IL-4 and IgE were measured by ELISA. RESULTS: 100 asthmatic children and 122 control children were all GG homozygotes at -179 locus of IFN-γ gene.-179 locus of IFN-γ gene has no mutation. The genotypes and allele frequency of IFN-γ gene +874A/T and CA repeat polymorphisms showed no significant difference between asthmatic children and the control(P>0.05). An association was revealed between IFN-γ gene +874A/T polymorphism and the level of plasma IFN-γ.The level of IFN-γ was lower in AA genotype than in AT genotype(P<0.05). The genotypes and allele frequency of IL-4 gene -33C/T and -589C/T polymorphisms showed significant difference between asthmatic children and the control(P<0.05).The levels of plasma IL-4 and IgE were higher in TT genotype at -33 locus and -589 locus than those in CT genotype, but only -33C/T polymorphism was associated with the level of plasma IL-4(P<0.05). CONCLUSION: The IFN-γ gene +874A/T and CA repeat polymorphisms were not correlated with asthmatic susceptibility, but there is significant correlation between the level of IFN-γ and +874A/T polymorphism. TT genotype of IL-4 gene -33 locus and -589 locus maybe the susceptible genotype of asthma in children, and the -33 locus polymorphism is associated with the level of IL-4.  相似文献   

14.
Plums (Prunus salicina cv. Songold) were cold stored for 10 d at -0.5°C followed by 18 d at 7.2°C and 7 d at 10°C. On the day of harvest and after 15,30 and 35 d of storage, the physiology, anatomy and development of internal disorders in inner and outer mesocarp tissue were assessed. Soluble solids, juice pH, internal conductivity, viscosity of soluble pectin and membrane leakage were significantly higher in the inner tissue, while titratable malic acid levels were lower, indicating that fruit was riper on the inside than the outside. Changes as indicated by the same variates showed that the rate of ripening in inner tissue was more rapid than in the outer mesocarp tissue over storage time. Gel breakdown in inner tissue was associated with high viscosities of water soluble pectin, permeable membranes, and as a result, binding of cell fluids which led to low levels of extractable juice. In outer tissue where extractable juice levels were higher, overripeness developed. At the ultrastructural level, it was evident that cell walls of inner tissue were thicker and had a better developed middle lamella than outer tissue. Inner mesocarp tissue was composed of larger cells than outer tissue.  相似文献   

15.
16.
AIM: To observe the effects of arsenic trioxide (As2O3) on activities of matrix metalloproteinases (MMPs), expression of tissue inhibitor of metalloproteinase-1 (TIMP-1) and transforming growth factor beta1 (TGF-β1) in human fibroblast (hFb), and to discuss weather As2O3 promotes the healing of chronic skin ulcer through regulating collagen metabolism. METHODS: Zymography was used for testing activity of MMP-9 deriving from rat polymorphonuclear neutrophils (PMNs) and activities of MMP-1, MMP-2 secreted by hFb. Immunocytochemical method was used to determine the expressions of TIMP-1 and TGF-β1. RESULTS: At the concentration of 50 mg/L, As2O3 elevated the activity of MMP-9 (P<0.01). At the concentration of 0.8 mg/L, As2O3 increased the activities of MMP-1 and MMP-2 (P<0.01, respectively). After hFb was cultured with As2O3 for 6 h, 12 h and 18 h, the expressions of TIMP-1 and TGF-β1 decreased continuously (P<0.01). CONCLUSION: As2O3 elevates the activities of MMP-1, MMP -2 and MMP-9, also inhibits the expressions of TIMP-1 and TGF-β1, suggesting that arsenic preparation may exert positive effect on healing chronic skin ulcer through regulating collagen metabolism.  相似文献   

17.

Context

Golden-cheeked warblers (Setophaga chrysoparia), an endangered wood-warbler, breed exclusively in woodlands co-dominated by Ashe juniper (Juniperus ashei) in central Texas. Their breeding range is becoming increasingly urbanized and habitat loss and fragmentation are a main threat to the species’ viability.

Objectives

We investigated the effects of remotely sensed local habitat and landscape attributes on point occupancy and density of warblers in an urban preserve and produced a spatially explicit density map for the preserve using model-supported relationships.

Methods

We conducted 1507 point-count surveys during spring 2011–2014 across Balcones Canyonlands Preserve (BCP) to evaluate warbler habitat associations and predict density of males. We used hierarchical Bayesian models to estimate multiple components of detection probability and evaluate covariate effects on detection probability, point occupancy, and density.

Results

Point occupancy was positively related to landscape forest cover and local canopy cover; mean occupancy was 0.83. Density was influenced more by local than landscape factors. Density increased with greater amounts of juniper and mixed forest and decreased with more open edge. There was a weak negative relationship between density and landscape urban land cover.

Conclusions

Landscape composition and habitat structure were important determinants of warbler occupancy and density, and the large intact patches of juniper and mixed forest on BCP (>2100 ha) supported a high density of warblers. Increasing urbanization and fragmentation in the surrounding landscape will likely result in lower breeding density due to loss of juniper and mixed forest and increasing urban land cover and edge.
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18.
Plant growth regulators play a vital role in fruit growth and development. However, effects of compounds belonging to the group of brassinosteroids have not been fully investigated in sweet cherries. One relatively new and one commonly applied growth regulator, 22S, 23S-Homobrassinolide and GA3, respectively, were tested on ‘Summit’ and ‘Regina’ sweet cherries to determine the effects on fruit quality and physiological disorders. The substances were applied with a handgun sprayer at full bloom and at the beginning of fruit development (shuck split) for a 2-year period. GA3 was applied at the concentrations of 25, 50, 100 mgL?1 and 22S, 23S-Homobrassinolide at 0.05, 0.1, 0.5 mgL?1. A combined application of 100 mgL?1 GA3 + 0.1 mgL?1 22S, 23S-Homobrassinolide was also applied. Effects of GA3 and 22S, 23S-Homobrassinolide on fruit weight and size were evident for the concentrations applied and between the seasons for both of the cultivars. Combination of the both growth regulators and 100 mgL?1 GA3 alone produced longer fruits compared to the control trees in ‘Regina’. The 22S, 23S-Homobrassinolide applications increased the firmness of the flesh slightly, but not to a great degree, compared to the GA3 applications alone. The brightness of the red color was better with GA3 applications in ‘Summit’ and ‘Regina’. Brassinosteroid caused the fruits to have comparably dull red color. Total soluble solid contents of the cultivars were influenced by the substances and the year of the application. Stem resistance to separation from the fruit was under the influence of both treatments and seasons. In general, 22S, 23S-Homobrassinolide provided better stem resistance than the GA3 applications. There were no effects of the substances on the development of physiological disorders.  相似文献   

19.
School grounds can have multiple values, and especially sufficient size, green elements, variation, integrated design and participatory development have been described as positive qualities. However, many studies have focused on pre-school and primary school grounds, while less is known about school grounds for adolescents. This study explored how secondary school students experience and use school grounds of varying size, content and design. The study included one class in year 8 (aged 14–15) at each of three schools in southern Sweden. A questionnaire with mainly open questions was distributed, followed by both individual interviews and walking interviews with four students from each class. The results show that school grounds were appreciated, but also that many chose to stay indoors. Large surface area and varied content, with ball courts, greenery, seating and multifunctional equipment, were valued, but a school ground design with integrated and pleasant settings, allowing socialising and activities, particularly support use by secondary school students.  相似文献   

20.
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