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631.
Juvenile Epinephelus coioides were exposed to three nominal concentrations (8, 32, 128 mg wet sediments L?1) of suspended sediments (SS) from Port Shelter (PS), Mirs Bay (MB) and Victoria Harbour (VH) for 10 and 30 days using semi‐static system. Sediments from VH contained higher concentrations of Cu and polycyclic aromatic hydrocarbons (PAHs) than sediments from PS and MB. Gill damages including lamellar blood sinus dilation and vascular congestion were prevalent after just 10 days of exposure to SS. Fish exposed to SS at the highest concentration of 128 mg L?1 showed higher incidence of lamellar aneurism. Hyperplasia in the base of lamellae was recorded in fish that had been exposed to contaminated SS from VH. Significant increases in the density of chloride cells and mucous cells were found on the gills of fish that had been exposed to 128 mg L?1 of SS from PS. Clogging of gills by SS produced hypoxic‐like responses in fish. Polluted sediments from VH produced addictive or synergistic effects between SS and chemical contaminants on fish. 相似文献
632.
Studies in mammals have shown that synthetic Met-enkephalin derivatives, called growth hormone-releasing peptides (GHRPs), stimulate growth hormone (GH) release. In the present study, GHRP-6 action on GH secretion was examined in vivo and in vitro in sexually immature grass carp. GHRP-6 injected intraperitoneally had no influences on serum GH levels in juvenile grass carp. Following intraperitonal injection of GHRP-6 and dopamine (DA) or cysteamine hydrochloride (CSH), alone and in combination into juvenile grass carp, DA and CSH were effective in elevating serum GH levels, but GHRP-6 was not effective in this respect; in addition, the synergistic action of GHRP-6 and DA or CSH on GH secretion was not seen. In this work, we had adapted and validated a perifusion system and a culture system for GH regulation studies. In a perifusion system, GHRP-6 (1000 to 0.1 nM), GHRP-6 (0.1 to 1000 nM), GHRP-6 (1 μM), and Hexarelin (an analog of GHRP, 1 μM) had no action on GH release from juvenile grass carp pituitary fragments or cells. Under static incubation conditions, GHRP-6 was inactive on GH release from juvenile grass carp pituitary fragments after 1 h and 6 h incubation, but human growth hormone-releasing hormone (hGHRH; 1 to 100 nM) as positive control could stimulate GH release in a dose-dependent manner. Furthermore, when GHRP-6 (100 nM) in combination static incubation with neuropeptides [e.g., hGHRH (100 nM), salmon gonadotropin-releasing hormone analogue (sGnRH-A) (100 nM), or D-Ala6,Pro9-NEt-luteinizing hormone-releasing hormone (D-Ala6,Pro9-NEt-LHRH, LHRH-A) (100nM)], GHRP-6 did not strengthen GH secretion actions of neuropeptides, and at the same time neuropeptides also did not modify the effects of GHRP-6 on GH secretion. The present results obtained using in vivo and in vitro techniques adapted for GH regulation studies show that GHRP-6 does not function as a GH-releasing factor in juvenile grass carp as it does in tilapia, amphibians, chickens, and mammals. 相似文献
633.
Nathan J. Robinson Peter G. Dahlhaus Megan Wong Andrew MacLeod Dean Jones Cam Nicholson 《Soil Use and Management》2019,35(1):94-104
Soil data form the basis of soil information systems across the globe. Soil information needs, and the questions posed by users, are likely to evolve in response to advances in technology in this era of Big Data. This poses a challenge to the pedological community which is already experiencing a decline in soil knowledge and expertise. With a decrease in soil data collection by governments, it is timely to reconsider how and what soil information should be provided to future users. A public–private partnership is advocated to deliver timely and accessible soil information to users. Two public–private provisioning programs are presented, and advantages and considerations for sharing soil data and information amongst industry, government, research organizations, service providers and land managers for these are discussed. Interoperable, open‐source and agreed soil community standards are used to present soil data and information through spatial web portals with tools for interpretation of soil data for public and private beneficiaries. 相似文献
634.
Simon X. B. Zhao David W. H. Wong David W. S. Wong Y. P. Jiang 《Growth and change》2020,51(1):338-361
In this new age of globalization, regions attempt to attract foreign direct investment (FDI) in order to achieve regionally balanced development. We revisit existing theories of regional development and FDI by analyzing recent data sets on FDI, employment, and trade in China, Southeast Asia, and South Asia. Using Chinese provincial data in 2004, 2008, and 2013 and applying panel estimations, our econometric results demonstrate that FDI remarkably influenced the concentration of employment in manufacturing, financial, and business services industries within the three Chinese macro-regions. We also find that FDI is ever transient, always moving away from high-cost to low-cost production bases across different regions. This transient nature of FDI is spatially selective and biased, and not able to generate the trickle-down effects to other neighboring regions. That is why FDI recently moved from China to Southeast and South Asia rather than from its coastal to inland regions. Furthermore, we show that this nature of FDI generally leads to polarization development for regions. As a synthesis or extension of the existing theories, we propose a leapfrog polarization pattern and strategy for vast developing countries in considering their regional development strategies. 相似文献
635.
636.
The relationship between a retroviral infection and the development of nonviral intracytoplasmic inclusion bodies was studied in a Boa constrictor model. Twelve juvenile age- and size-matched inclusion body disease (IBD)-negative boas were randomly divided into three groups. Each group was inoculated intraperitoneally with 1 ml of an IBD virus (IBDV)-infected liver homogenate or 1 ml of normal boa liver homogenate (sham-inoculated control) or was left untreated. All boas were monitored for development of IBD by daily examination and serial liver biopsy over 1 year. The 4 IBDV-inoculated boas became IBDV and inclusion positive by 10 weeks postinoculation. The average size and density of inclusion bodies increased with the duration of infection. Ultrastructurally, inclusion bodies <2 microm in diameter consisted of intracytoplasmic aggregates of granular electron-dense material that were not membrane limited. Larger inclusions (3-6 microm in diameter) were characterized as membrane-bound aggregates of amorphous to granular electron-dense material admixed with membranelike fragments. The sham-inoculated and untreated control snakes did not become inclusion or IBDV positive. Direct comparison of the protein electrophoretograms of IBDV-infected and normal boa tissues demonstrated a prominent 68-kd protein band unique to infected inclusion-positive tissues. Monoclonal antibodies directed against the 68-kd protein band specifically labeled inclusion bodies. The results of this study demonstrate that IBD inclusions represent an intracytoplasmic accumulation of an antigenically distinct IBDV-associated protein. 相似文献
637.
Wong DF Wagner HN Dannals RF Links JM Kuhar MJ Gjedde A 《Science (New York, N.Y.)》1986,232(4755):1270-1271
638.
639.
Increase in the plant protein ratio in the diet of white shrimp,Litopenaeus vannamei (Boone), using Bacillus subtilis E20‐fermented soybean meal as a replacement 下载免费PDF全文
Ya‐Li Shiu Saou‐Lien Wong Wang‐Chen Guei Yu‐Ching Shin Chun‐Hung Liu 《Aquaculture Research》2015,46(2):382-394
This study aimed to improve the nutritional value and utilization of soybean meal (SBM) used as feed ingredient for shrimp by an approach of solid‐state fermentation with Bacillus subtilis E20. The protein content and B. subtilis E20 proliferation significantly increased, as the initial moisture increased from 30% to 50% during fermentation. Compared with SBM, the protein content of FSBM increased by 19% after fermentation, accompanied by an increase of 18.75% in the total hydrolyzed amino acids. The free amino acid profile and content in FSBM also obviously increased by 374.9% compared with SBM. The FSBM is a good substitute for fish meal (FM) in a diet with 37% protein and 7% lipid content. The maximal replacement levels of FM in shrimp diet with SBM and FSBM were 37.42% and 61.67%, respectively, based on the feed efficiency estimated by a broken‐line analysis. The B. subtilis E20‐FSBM can be a potential protein source used as a replacement for FM in shrimp diet. 相似文献
640.
Currie CR Wong B Stuart AE Schultz TR Rehner SA Mueller UG Sung GH Spatafora JW Straus NA 《Science (New York, N.Y.)》2003,299(5605):386-388
The symbiosis between fungus-growing ants and the fungi they cultivate for food has been shaped by 50 million years of coevolution. Phylogenetic analyses indicate that this long coevolutionary history includes a third symbiont lineage: specialized microfungal parasites of the ants' fungus gardens. At ancient levels, the phylogenies of the three symbionts are perfectly congruent, revealing that the ant-microbe symbiosis is the product of tripartite coevolution between the farming ants, their cultivars, and the garden parasites. At recent phylogenetic levels, coevolution has been punctuated by occasional host-switching by the parasite, thus intensifying continuous coadaptation between symbionts in a tripartite arms race. 相似文献