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1.
Sang-Hyun Lee Jin-Ho Choi Wol-Soo Kim Tae-Ho Han Yong-Seo Park Hirosi Gemma 《Scientia Horticulturae》2006
This study was carried out to investigate the cause of stone cell formation in pear (Pyrus pyrifolia cv. ‘Niitaka’) flesh. Potted plants grown in a glass house were subjected to water stress conditions without irrigation for 30 days from 30 days before full bloom (BFB treatment), full bloom (FB treatment) and 30 days after full bloom (AFB treatment). Control plants were drip-irrigated daily maintaining a soil matrix potential around −40 ± 5 kPa. The formation of stone cells in pear flesh increased in the FB treatment and AFB treatment plants and this tendency was sustained until the harvest season. Root activity was investigated 60 days after full bloom (DAFB) and the triphenyltetrazolium chloride (TTC) reduction potential, the formazan content and leaf water potential were investigated 30, 45, and 60 DAFB. Root activity decreased progressively due to the effect of water stress. Also, the Ca content in leaf and flesh was lower. The peroxidase activity was high in the flesh at the early stages of fruit growth and decreased at the late stages of fruit growth, and then a higher increase of peroxidase activity was observed in water-stressed fruit. The reduction in calcium content of leaf and fruit in plants under water stress may be related to the reduction of root activity and leaf water potential. The increase in peroxidase activity under water stress may be due to limited calcium absorption. Higher peroxidase activity may induce the accumulation of lignin in the cell wall and promote the formation of stone cells in pear flesh. We conclude that water stress condition during the early stages of fruit growth is one of several factors that determine the formation of stone cells in pear flesh. 相似文献
2.
The primary objective of this study was to evaluate the effects of foliar boron and calcium application after harvest on the quantity and activity of pollen in the ‘Housui’ and ‘Wonwhang’ pears on a subsequent year. Pollen grains of the ‘Housui’ pear were cultured on germination medium, to which had been added boric acid (0, 25, 75, 100, 200, 300, 400, and 500 mg L−1) and calcium nitrate (0, 10, 25, 50, 100, 150, 200, 250, 300, 400, and 500 mg L−1). Boric acid, which was added to the germination media, exerted a significant stimulatory effect on both pollen germination and pollen tube growth, although pollen tube growth was inhibited at higher concentrations than 300 mg L−1. Calcium nitrate addition stimulated pollen germination, except at concentration of 500 mg L−1. However, pollen tube growth was significantly inhibited with increasing concentrations of calcium nitrate. In the orchard experiment, boron and calcium were sprayed at concentrations of 0, 100, 200, 500 or 1000 mg L−1 onto leaves after harvest, respectively. Boron and calcium content in the tissues as well as pollen production and growth were determined after these treatments. The foliar application of boron mainly resulted in an increase of boron concentration in buds. It also induced an increase in the weight of the anther and pollen in the following year. On the other hand, the foliar application of calcium resulted in an increase of calcium concentration mainly in the leaves, but pollen weight was decreased at high concentration treatment in the following year. The germination rate and tube growth of collected pollen were highest in the trees which had received boron treatment at a concentration of 200 mg L−1. In contrast, the germination rate and tube growth of collected pollen were decreased by calcium application at concentrations of 500 and 1000 mg L−1 without significant increase at lower concentrations. Consequently, the accumulation of boron in the developed buds of pear trees subjected to post-harvest foliar boron application generated positive effects on both the quantity and quality of pollen in the following year. 相似文献
3.
四环素类抗生素在土壤和堆肥中的吸附和降解 总被引：6，自引：0，他引：6
Two agricultural soils were collected from Dahu and Pinchen counties and swine manure compost (SMC) from Ping-tung County in Taiwan, China to investigate the sorption and dissipation of three tetracyclines (TCs), i.e., oxytetracycline (OTC), tetracycline (TC) and chlortetracycline (CTC), in compost, soils and soil/compost mixtures with different organic carbon (OC) contents. There were seven treatments in total. TCs were most strongly adsorbed to SMC in all treatments due to the high OC content. When SMC was present in the soils, the sorption of TCs was significantly enhanced, which might be attributed to the increased OC content and CEC. The adsorption of TCs showed non-linear adsorption isotherms and fitted well to the Freundlich model. After 49 d of incubation at 25 ℃ in soils and soil/compost mixtures in the dark, TCs elapsed in all substrates, with the time required for 50% degradation (DT50) between 20 and 41 d, and the time for 90% degradation (DT90) between 68 and 137 d. Soil amended with compost enhanced the stability of TCs and reduced their mobility. The dissipation of TCs in a soil environment was slow, indicating that these compounds might be persistent in soil. 相似文献
4.
Two agricultural soils were collected from Dahu and Pinchen counties and swine manure compost (SMC) from Pingtung County in Taiwan, China to investigate the sorption and dissipation of three tetracyclines (TCs), i.e., oxytetracycline (OTC), tetracycline (TC) and chlortetracycline (CTC), in compost, soils and soil/compost mixtures with different organic carbon (OC) contents. There were seven treatments in total. TCs were most strongly adsorbed to SMC in all treatments due to the high OC content. When SMC was present in the soils, the sorption of TCs was significantly enhanced, which might be attributed to the increased OC content and CEC. The adsorption of TCs showed non-linear adsorption isotherms and fitted well to the Freundlich model. After 49 d of incubation at 25 oC in soils and soil/compost mixtures in the dark, TCs elapsed in all substrates, with the time required for 50% degradation (DT50) between 20 and 41 d, and the time for 90% degradation (DT90) between 68 and 137 d. Soil amended with compost enhanced the stability of TCs and reduced their mobility. The dissipation of TCs in a soil environment was slow, indicating that these compounds might be persistent in soil. 相似文献
5.
The Firm as Social Networks: An Organisational Perspective 总被引：1，自引：0，他引：1
HENRY WAI‐CHUNG YEUNG 《Growth and change》2005,36(3):307-328
ABSTRACT This paper offers an organizational perspective on the firm in new economic geographies. It starts with the premise of the firm as a production function in neoclassical economics and a cost minimisation device in transaction cost economics. By pointing out the inadequacy in these mainstream economic perspectives on the firm, I draw upon recent behavioral and managerial theories to develop a relational conception of the firm as social networks in which actors are embedded in ongoing power relations and discursive processes. In further elaborating this relational perspective on the firm as an organisational device, I show how the firm is governed through social relations among different actors, how it is a site of contested ideologies and political representations among these actors, and how space and geographical scales matter in shaping its social construction. Taken together, this organisational perspective aims to shift our research agenda in urban and regional development from promoting the growth of the firm per se to understanding how the firm serves as a relational institution that connects spatially differentiated actors in different places and regions. 相似文献
6.
固体粉末可以作为乳化剂早在本世紀初就已发现[1]。由于所得的乳浊液一般地讲液滴较粗,稳定性也差,因而长期以来很少被注意。最近L.N.Mukerjee和S.N.Srivastava等人系統地检查了多种难溶无机化合物和粘土作为工业用和农业喷洒用乳化剂的可能性[2,3]。但对于粘土粉末作为乳化剂的条件没有深入研究。本文是研究一定pH范围内几种本国粘土的乳化效能。 相似文献
7.
Heh-Myung Ghil Jong-Hyeon Yoo Woo-Sung Jung Tae-Ho Chung Hwa-Young Youn Cheol-Yong Hwang 《Journal of veterinary science (Suw?n-si, Korea)》2009,10(1):67-72
Discovery of Helicobacter (H.) pylori has led to a fundamental change in our understanding of gastric diseases in humans. Previous studies have found various Helicobacter spp. in dogs and cats, and pets have been questioned as a zoonotic carrier. The present study surveyed the Helicobacter infections and investigated the presence of H. felis and H. pylori infections in domestic and feral cats in Korea. Sixty-four domestic cats and 101 feral cats were selected from an animal shelter. Saliva and feces were evaluated by Helicobacter genus-specific polymerase chain reaction (PCR). Genus-specific PCR positive samples were further evaluated for H. felis and H. pylori using specific primer pairs. Thirty-six of 64 (56.3%) samples from domestic cats and 92 of 101 (91.1%) samples from feral cats were PCR positive; the positive rate of feces samples was higher than that of saliva samples in both groups. H. felis and H. pylori species-specific PCR was uniformly negative. The prevalence of Helicobacter spp. in feral cats was approximately two-fold higher than that of domestic cats. The fecal-oral route may be more a common transmission route not only between cats but also in humans. 相似文献
8.
MIN SU LEE JEFF KO AH RA LEE IN HYE LEE MI AE JUNG BRENDA AUSTIN HYUNWOO CHUNG SANGSOEP NAHM KIDONG EOM 《Veterinary radiology & ultrasound》2010,51(2):130-135
The purpose of this study was to assess the effects of four anesthetic protocols on normal canine brain uptake of 2‐deoxy‐2‐[18F]fluoro‐d ‐glucose (FDG) using positron emission tomography/computed tomography (PET/CT). Five clinically normal beagle dogs were anesthetized with (1) propofol/isoflurane, (2) medetomidine/pentobarbital, (3) xylazine/ketamine, and (4) medetomidine/tiletamine–zolazepam in a randomized cross‐over design. The standard uptake value (SUV) of FDG was obtained in the frontal, parietal, temporal and occipital lobes, cerebellum, brainstem and whole brain, and compared within and between anesthetic protocols using the Friedman test with significance set at P<0.05. Significant differences in SUVs were observed in various part of the brain associated with each anesthetic protocol. The SUV for the frontal and occipital lobes was significantly higher than in the brainstem in all dogs. Dogs receiving medetomidine/tiletamine–zolazepam also had significantly higher whole brain SUVs than the propofol/isoflurane group. We concluded that each anesthetic protocol exerted a different regional brain glucose uptake pattern. As a result, when comparing brain glucose uptake using PET/CT, one should consider the effects of anesthetic protocols on different regions of the glucose uptake in the dog's brain. 相似文献
9.
AH RA LEE MIN SU LEE IN SEONG JUNG DAE YOUNG KIM SANG SEOP NHAM HYUN WOO CHUNG KIDONG EOM 《Veterinary radiology & ultrasound》2010,51(2):145-147
An 8‐year‐old Shih Tzu developed abdominal pain and hyperglobulinemia. A round splenic mass was noted radiographically and sonographically. The patient was evaluated by fluorodeoxyglucose positron emission tomography coupled with computed tomography (FDG‐PET/CT). There was no evidence of metastasis or bone marrow involvement on PET/CT images. The standardized uptake value (SUV) of the splenic mass was increased over the reference range (SUV=4.83). The patient was diagnosed as splenic extramedullary plasmacytoma through immunohistopathologic study. After the splenectomy, the globulin level normalized and the patient is alive without complications. 相似文献
10.
A pot experiment was conducted in a plastic film house to evaluate the translocation and uptake of heavy metals(Pb,Cd,Cu,and Zn) into brown rice(Oryza sativa L.) and the heavy metals residues in soils which had previously been irrigated with domestic wastewater for a long time(3 years).The range of Pb,Cd,Cu,and Zn was 5.10 ± 0.01,0.105 ± 0.017,5.76 ± 0.42,and 23.56 ± 1.40 mg kg-1,respectively in the domestic wastewater-irrigated soil,and 0.370 ± 0.006,0.011 ± 0.001,0.340 ± 0.04,and 2.05 ± 0.18 mg kg-1,respectively,in the domestic wastewater-irrigated brown rice.The results indicated that application of domestic wastewater to arable land slightly increased the levels of Pb,Cd,Cu,and Zn in soil and brown rice(P < 0.01).The concentrations of heavy metals in brown rice were lower than the recommended tolerable levels proposed by the Joint FAO/WHO Expert Committee on Food Additives.However,the continuous monitoring and pollution control of hazardous materials from domestic wastewater are needed in order to prevent excessive build-up of heavy metals in the food chain. 相似文献