Effects of dbcAMP on steroidogenesis in isolated ovarian follicles of Atlantic salmon     

M. Watts  N.W. Pankhurst  H. King 《Fish physiology and biochemistry》2003,28(1-4):375-376

In vitro estradiol-17β (E₂) and testosterone (T) production were measured in vitellogenic follicles of Atlantic salmon in response to treatment with human chorionic gonadotropin (hCG) and 2-0-dibutyryladenosine 3′,5′-cyclic monophosphate (dbcAMP). DbcAMP stimulated T production but had no effect on E₂, whereas hCG treatment stimulated E₂ production but T production was low. Elevated intracellular [cAMP] may be part of the normal mechanism for inhibition of aromatase activity at the end of vitellogenesis.  相似文献   

Evaluating changes in switchgrass physiology,biomass, and light-use efficiency under artificial shade to estimate yields if intercropped with Pinus taeda L.     

Janine M. Albaugh  Timothy J. Albaugh  Ryan R. Heiderman  Zakiya Leggett  Jose L. Stape  Kyle King  Katherine P. O’Neill  John S. King 《Agroforestry Systems》2014,88(3):489-503

There is growing interest in using switchgrass (Panicum virgatum L.) as a biofuel intercrop in forestry systems. However, there are limited data on the longevity of intercropped bioenergy crops, particularly with respect to light availability as the overstory tree canopy matures. Therefore, we conducted a greenhouse study to determine the effects of shading on switchgrass growth. Four treatments, each with different photosynthetically active radiation (PAR) levels, were investigated inside the greenhouse: control (no shade cloth, 49 % of full sunlight), low (under 36 % shade cloth), medium (under 52 % shade cloth), and heavy shade (under 78 % shade cloth). We determined the effect of shading from March to October 2011 on individually potted, multi-tillered switchgrass transplants cut to a stubble height of 10 cm. In the greenhouse, there was a reduction in tiller number, tiller height, gas exchange rates (photosynthesis and stomatal conductance), leaf area, above- and belowground biomass and light-use efficiency with increasing shade. Total (above- and belowground) biomass in the control measured 374 ± 22 compared to 9 ± 2 g pot^?1 under heavy shade (11 % of full sunlight). Corresponding light-use efficiencies were 3.7 ± 0.2 and 1.4 ± 0.2 g MJ^?1, respectively. We also compared PAR levels and associated aboveground switchgrass biomass from inside the greenhouse to PAR levels in the inter-row regions of a range of loblolly pine (Pinus taeda L.) stands from across the southeastern United States (U.S.) to estimate when light may limit the growth of intercropped species under field conditions. Results from the light environment of loblolly pine plantations in the field suggest that switchgrass biomass will be significantly reduced at a loblolly pine leaf area index between 1.95 and 2.25, which occurs on average between ages 6 and 8 years across the U.S. Southeast in intensively managed pine plantations. These leaf area indices correspond to a 60–65 % reduction in PAR from open sky.  相似文献   

Phosphorus utilization in rainbow trout (Oncorhynchus mykiss) fed practical diets and its consequences on effluent phosphorus levels   总被引：2，自引：0，他引：2  

Relicardo M. Coloso  Kim King  John W. Fletcher  Michael A. Hendrix  Mark Subramanyam  Peddrick Weis  Ronaldo P. Ferraris   《Aquaculture (Amsterdam, Netherlands)》2003,220(1-4):801-820

Excessive dietary phosphorous (P) concentrations in effluents from aquaculture present a major environmental problem. We therefore studied the effect of dietary P and vitamin D₃ on P utilization by rainbow trout-fed practical diets and on P concentrations in the soluble, particulate and settleable components of the effluent from fish tanks. Rainbow trout (average weight: 78 g, initial biomass: 13 kg in 0.7 m³ tanks) were fed for 11 weeks, practical diets that varied in total P, available P, and vitamin D₃ concentrations. Soluble, particulate (10–200 μm) and settleable (>200 μm) P in the effluent were sampled every 0.5–6 h for 1–3 days in the third and eleventh weeks of the experiment. Trout in all diets more than doubled their weight after 11 weeks. Increasing the concentrations of available dietary P from 0.24% to 0.88% modestly enhanced growth rate. Feed conversion ratio (FCR) and biomass gain per gram P consumed decreased as dietary P concentrations increased. Carcass P, daily P gain, and plasma P concentrations were lower in fish fed with low P diets. Soluble P concentrations in the effluent peaked immediately after and again 4–6 h after feeding, and is a linear function of available dietary P. No soluble P would be produced during consumption of diets containing less than 0.22±0.02% available P. Above this dietary concentration, soluble P would be excreted at 6.9±0.4 mg/day/kg for each 0.1% increase in available dietary P. Particulate P concentrations in the effluent were independent of dietary P concentrations. Settleable, presumably fecal, P concentrations tended to increase with dietary P concentrations. In trout fed with low P (0.24% available P, 0.6% total P) diets, 60% of total dietary P were retained by the fish and the remaining 40% were excreted in the effluent as settleable P (20–30%) and particulate or soluble P (10–20%). In trout fed with high P (0.59–0.88% available P; 0.9–1.2% total P) diets, 30–55% of total dietary P was retained by fish, and the remaining 15–25% appeared in the effluent as settleable P, 20–55% as soluble P, and 5–10% as particulate P. Vitamin D₃ did not affect fish growth nor effluent P levels. Physicochemical management of aquaculture effluents should consider the effect of diets on partitioning of effluent P, the peaks of soluble P concentration following feeding, and the contributions of particulate P to total P in the effluent. Increasing our understanding of how dietary P is utilized and is subsequently partitioned in the effluent can contribute significantly towards alleviating this important environmental and industry problem.  相似文献   

Larval and juvenile Australian smelt Retropinna semoni somatic and otolith growth parameters – implications for growth interpretation of wild fish     

Z. D. Tonkin  D. S. L. Ramsey  A. J. King 《Ecology of Freshwater Fish》2008,17(3):489-494

Abstract –  Relationships between fish length, otolith size, age and weight were assessed for a population of wild Australian smelt ( Retropinna semoni ) larvae and juveniles captured over a 4-year period to aid further interpretation of growth and condition during the early life history of the species. Nonlinear smoothed generalized additive models best described the fish–otolith size relationship during the larval and juvenile period, indicating that the proportionality between fish length and otolith size varies in relation to size. It is proposed that back-calculated predictions of fish size at a previous age or otolith size, accounting for individual variation is possible by assuming a body proportional hypothesis. Growth rate of larval and juvenile Australian smelt was best described using the Gompertz model that indicated a steady decline in growth rate after around 30 days of age. The allometric growth of larval and juvenile Australian smelt established from the length/weight relationship can subsequently be used to assess the condition of fish within this population using a relative condition or relative weight condition index. The results of the study have provided significant information to enable more precise growth reconstruction and condition assessment for the species in Australian lowland rivers.  相似文献   

Explaining urban governance in the midst of political transformation: The city of Macao          下载免费PDF全文

Li Sheng  Penny Yim King Wan 《Asia Pacific viewpoint》2017,58(3):289-300

This paper takes a close look at the urban governance and political culture of Macao, the world largest casino city. Macao has experienced spectacular economic growth since gaming liberalisation in 2002 and China's Free Individual Travel scheme launched in 2003. However, the booming gaming sector has crowded out other sectors of Macao. It has not only made the city's economy mono‐structured and consequently extremely vulnerable to external shocks and fluctuations but also induced serious social divisions and political controversies within the local community. By tracing the root cause of the ongoing dilemma and crisis in the mode of governance, the dynamic relationships between formal and informal institutions, consensus politics and the social group culture are intensively discussed in a historical context. In fact, the sustainable development of the former Portuguese colony has largely been hindered by its residents' passive attitudes toward political communication, non‐transparent urban governance, the absence of a middle class and the dominance of pro‐establishment social groups.  相似文献   

Drugs and foods from little-known plants: by Siri von Reis Altschul. University Press,Harvard, and Oxford University Press,London: xii + 366 pp., 24 × 16 cm, £5.00, 1973     

C.J. King 《Biological conservation》1974,6(4):318-319

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Nasopharyngeal cryptococcosis   总被引：1，自引：0，他引：1  

R MALIK  P MARTIN  DI WIGNEY  DB CHURCH  W BRADLEY  CR BELLENGER  WA LAMB  VR BARRS  S FOSTER  S HEMSLEY  PJ CANFIELD  DN LOVE 《Australian veterinary journal》1997,75(7):483-488

Naturally occurring cryptococcosis in five cats, a dog and a koala is described. Involvement of the nasopharynx was documented in all patients, and nasopharyngeal mass lesions accounted for the major presenting complaints in four. Signs referable to nasopharyngeal disease included snoring, stertor, inspiratory dyspnoea and aerophagia. Diagnoses were made by caudal rhinoscopy using a retroverted flexible endoscope, vigorous orthograde flushing with saline, or at necropsy. Concurrent cryptococcal rhinitis was present in all cases, although involvement appeared limited to the caudal nasal cavity in most cases. Typical signs of nasal cavity disease, such as sneezing and nasal discharge, were often absent. Treatment of nasopharyngeal cryptococcosis should include physical dislodgement or debulking of lesion(s) to provide immediate alleviation of upper airway obstruction, followed by systemic antifungal therapy to eliminate residual infection from the nasal cavity. Infections caused by Cryptococcus neoformans var gattii accounted for a disproportionately large number of these cases.  相似文献   

Embryonic development in the blue fox     

M Valtonen  W A King  I Gustavsson  A M?kinen 《Nordisk veterinaermedicin》1985,37(4):243-248

Embryos from vixens at different stages of gestation were measured and photographed. Implantation was observed 16-18 days after breeding. Differentiation and the development of characteristic features were described and embryonic loss was studied in relation to number of corpora lutea.  相似文献   

Contrast radiography of the equine oesophagus: effect of spasmolytic agents and passage of a nasogastric tube     

J N King  J V Davies  E L Gerring 《Equine veterinary journal》1990,22(2):133-135

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Evaluation of maternal parent and puroindoline allele on kernel texture in a reciprocal cross between two hard spring wheat cultivars     

Kristene R. Gedye  Arthur D. Bettge  Garrison E. King  Craig F. Morris 《Euphytica》2005,141(1-2):121-127

Kernel texture is an important characteristic for both the milling and the end-use quality of wheat (Triticum aestivum L.). Gene sequence variation and mutations to the two puroindoline genes (Pina and Pinb), located at the Ha locus on chromosome 5DS, account for the majority of variation in wheat kernel texture. Other factors also influence kernel texture, including effects associated with different maternal parent backgrounds. To investigate the effect of two hard puroindoline alleles in different maternal backgrounds, a population of 228 recombinant inbred lines (RILs) derived from a reciprocal cross between two wheat cultivars ID377s (Pina-D1b/Pinb-D1a) and Klasic (Pina-D1a/Pinb-D1b) were examined in two succeeding generations (F₇ & F₈). Kernel texture was determined using the Single Kernel Characterization System (SKCS) and the RIL puroindoline haplotype was identified by the sequence-specific PCR amplification of each gene. Analysis of variance identified a significant (P 0.001) effect of the maternal parent and puroindoline mutation on kernel texture. RILs containing the Pina-D1b mutation were significantly harder than lines containing the Pinb-D1b mutation. RILs which had Klasic as the maternal parent were significantly harder than those which had ID377s as the maternal parent. When the maternal parent and puroindoline allele were analyzed in combination, RILs derived from Klasic as the maternal parent and the Pina-D1b allele were significantly harder (P 0.001) than those containing the same allele but ID377s as the maternal parent. The same occurred for RILs containing the Pinb-D1b allele, lines with Klasic as the maternal parent were harder than lines with ID377s as the maternal parent. These results corroborate the harder phenotype of the Pina-D1b allele and indicate a significant maternally-inherited contribution to kernel texture variation.  相似文献