Effect of the dusk photoperiod change from light to dark on the incubation period of eggs of the spotted rose snapper, Lutjanus guttatus (Steindachner)     

Neil J Duncan  Leonardo Ibarra-Castro  & Ricardo Alvarez-Villaseñor 《Aquaculture Research》2008,39(4):427-433

Spotted rose snapper, Lutjanus guttatus (Steindachner), eggs were incubated under different photoperiods to examine the effect of photoperiod on incubation. The eggs from two fish were incubated under five artificial photoperiods: constant dark (D), constant light (L) from 06:00 hours and 6, 10 and 14 h of light from 06:00 hours. The eggs from seven other fish were incubated under a natural photoperiod. Different spawning times (21:00 – 01:00 hours) and different photoperiods combined to give the start of the dusk photoperiod change after 11–23 h of incubation. Constant light or applying the dusk photoperiod change after ≥20 h of incubation appeared to extend the hatching period. The mean hatching period for groups of eggs incubated in darkness or that received the dusk photoperiod change after ≤19 h of incubation (n=8 different groups) was 2 h 15±10 min, which was significantly lower (P<0.05) than the mean hatching period of 4 h±37 min for groups that did not receive the dusk photoperiod change or that received the dusk photoperiod change after ≥20 h of incubation (n=9 groups). However, despite these differences, the majority of the eggs hatched during a 2–3 h period from 17 to 20 h of incubation, and a sigmoid regression (r²=0.9) explained the relationship between percentage hatch and hours of incubation for all photoperiod groups.  相似文献   

Density management and biodiversity in young Douglas-fir forests: Challenges of managing across scales     

Duncan S. Wilson  Klaus J. Puettmann 《Forest Ecology and Management》2007

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Detection of a chitinase-like protein in the roots of Douglas-fir trees infected with Armillaria ostoyae and Phellinus weirii     

Robinson RM  Sturrock RN  Davidson JJ  Ekramoddoullah AK  Morrison DJ 《Tree physiology》2000,20(8):493-502

Protein was extracted from root bark of 11- and 25-year-old interior Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees that were naturally infected with Armillaria ostoyae (Romagnesi) Herink. The proteins were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Root bark tissue adjacent to infected areas had a significantly higher protein concentration than healthy tissue (P < 0.05), whereas the protein concentration of infected tissue was consistently lower (P < 0.05) than that of healthy tissue. The SDS-PAGE profiles of healthy, infected, and adjacent-to-infected root bark tissues revealed significant differences in concentrations of a 29.3-kDa protein. The N-terminal amino acid sequence of the 29.3-kDa protein displayed significant homology (P = 0.013) to a basic endochitinase. Use of a polyclonal antibody raised against the 29.3-kDa putative endochitinase-like protein (ECP) indicated differences in the quantities of ECP in healthy roots compared with roots infected with A. ostoyae in 11- and 25-year-old interior Douglas-fir trees. The antibody was also used to screen for the presence of the 29.3-kDa protein in roots of 24-year-old coastal Douglas-fir (Pseudotsuga menziesii var. menziesii) trees that were artificially inoculated with and colonized by Phellinus weirii (Murr.) Gilbn. The amount of ECP was elevated in root bark of coastal Douglas-fir in response to P. weirii infection, although in lower quantities relative to those found in the A. ostoyae-interior Douglas-fir pathosystem. The sequence homology of the ECP with a basic chitinase, together with its increased synthesis in response to two fungal pathogens, indicate a possible role for this protein in the defense of Douglas-fir against fungal pathogens.  相似文献   

Seasonal and temperature dependence of photosynthesis and respiration for two co-occurring broad-leaved tree species with contrasting leaf phenology     

Dungan RJ  Whitehead D  Duncan RP 《Tree physiology》2003,23(8):561-568

We measured the seasonal and temperature responses of leaf photosynthesis and respiration of two co-occurring native New Zealand tree species with contrasting leaf phenology: winter-deciduous fuchsia (Fuchsia excorticata J. R. Forst & G. Forst) and annual evergreen wineberry (Aristotelia serrata J. R. Forst & G. Forst). There was no difference in the amount of nitrogen per unit leaf area (Narea, range 40-160 mmol m-2, P = 0.18) or specific leaf area (S, range 8-27 m2 kg-1, P = 0.87) in summer leaves of wineberry or fuchsia. The amount of nitrogen per unit leaf area and S varied significantly with height of leaves in the canopy for both species (r2 range 0.61-0.87). Parameters describing the maximum rates of rubisco carboxylation (Vcmax) and electron transport (Jmax) were related significantly to Narea, and were 60% higher on average in spring and summer leaves than in autumn and winter leaves for both species. The seasonal effect remained significant (P < 0.001) when Narea was included in a regression model, indicating that seasonal changes were not only due to changes in Narea. Values for Vcmax and Jmax were 30% lower in wineberry leaves than in fuchsia leaves on average, although the difference ranged from 15% in summer leaves to 39% in autumn leaves. Activation energies describing the temperature dependence of Vcmax and Jmax in wineberry were 111 and 114% of corresponding values for fuchsia (Ea (Vcmax) = 39.1 kJ mol-1, Ea (Jmax) = 32.9 kJ mol-1). Respiration at night was the same (P = 0.34) at 10 degrees C for both species (R10 = 0.7 micromol m-2 s-1), although activation energies (E0) were higher in wineberry than in fuchsia (47.4 and 32.9 kJ mol-1 K-1, respectively). These results show that rates of photosynthesis are higher in winter-deciduous fuchsia than in annual evergreen wineberry.  相似文献   

Thoracoscopic Lung Lobectomy for Primary Lung Tumors in 13 Dogs          下载免费PDF全文

Seth Bleakley  Colleen G. Duncan  Eric Monnet 《Veterinary surgery : VS》2015,44(8):1029-1035

Objectives

To report our experience with thoracoscopic lung lobectomy in dogs with primary lung tumors and compare the long‐term outcome between dogs with primary lung tumors treated with lobectomy via thoracoscopy or thoracotomy.

Study Design

Retrospective case series; case–control study.

Animals

Thirteen dogs with primary lung tumors treated with thoracoscopic lung lobectomy; case‐matched cohort of 9 dogs with primary lung tumors treated with lobectomy via thoracotomy.

Methods

Medical records from dogs that underwent thoracoscopic lung lobectomy at a single institution were reviewed. Only cases with primary lung tumors were included. Surgical complications and conversion rate were reported. Cases without conversion and with clean margins on histologic examination were matched on prognostic criteria to cases with primary lung tumors treated with lobectomy via thoracotomy. Survival was compared between thoracoscopy and thoracotomy.

Results

Thirteen dogs with primary lung tumors that measured 2.2–7 cm underwent thoracoscopic lung lobectomy. Nine dogs were diagnosed with carcinoma and 4 with histiocytic sarcoma. There were 3 conversions to open thoracotomy because of poor visualization. There were no differences in short‐term outcome between dogs that had their procedures completed via thoracoscopy and those that were converted to thoracotomy. Nine dogs with clean margins were matched with 9 dogs treated via thoracotomy. Mean (standard deviation) followup was 367 (327) days for dogs undergoing thoracoscopy and 603 (612) days for dogs undergoing thoracotomy. The 2‐year survival rate was 44% for thoracoscopy and 56% for thoracotomy (P = .942).

Conclusion

Selected primary lung tumors in dogs can be safely resected with thoracoscopy and not affect long‐term outcome.

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Metatranscriptomics reveals metabolic adaptation and induction of virulence factors by Haemophilus parasuis during lung infection     

Bernardo Bello-Ortí  Kate J. Howell  Alexander W. Tucker  Duncan J. Maskell  Virginia Aragon 《Veterinary research》2015,46(1)

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Expression of a glycoprotein hormone receptor gene in the ovary of the bullseye puffer (Sphoeroides annulatus)     

J.N. Gutiérrez  N.J. Duncan  N. García-Aguilar  P.V. Estañol  A. García-Gasca 《Fish physiology and biochemistry》2003,28(1-4):341-342

A fragment of a glycoprotein hormone receptor (GpHR) gene was isolated from the ovary of the bullseye puffer. This cDNA fragment showed similarity to the thyrotropin (TSH) and gonadotropin (LH and FSH) receptors. GpHR mRNA expression in the ovary gradually increased during oocyte maturation.  相似文献   

Whole blood manganese concentrations in dogs with primary hepatitis     

S. Kilpatrick  A. Jacinto  R. D. Foale  S. W. Tappin  C. Burton  P. E. Frowde  C. M. Elwood  R. Powell  A. Duncan  R. J. Mellanby  A. G. Gow 《The Journal of small animal practice》2014,55(5):241-246

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Coil Embolization of a Palatine Artery Pseudoaneurysm in a Gelding     

Nathaniel R. McClellan DVM  Margaret C. Mudge VMD  Diplomate ACVS  ACVECC  Brian A. Scansen DVM  MS  Diplomate ACVIM  Stephen S. Jung MD  FACR  Duncan Russell BVMS  Diplomate ACVP 《Veterinary surgery : VS》2014,43(4):487-494

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Gamna‐Gandy bodies: a case of mistaken identity in the spleen of a cat     

Julia K. Ryseff  Colleen Duncan  Gabriella Sfiligoi  Paul R. Avery 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2014,43(1):94-100

A 4‐year‐old, female spayed Domestic Shorthair cat was presented for a 2‐day history of lethargy, anorexia, and vomiting. Diagnostic assessments revealed a severe, regenerative anemia and the presence of a solitary, 3 × 4 cm splenic mass. Cytologic examination of fine‐needle aspirates of the splenic mass showed sheets of pleomorphic histiocytic cells with numerous intracellular and extracellular, negatively staining to deeply basophilic, branching structures. These structures were typically of thin uniform thickness with random angled branching that formed geometrical shapes and fragments, occasionally with sharpened ends and a crystalline appearance. Septal‐like divisions were irregularly spaced along some of the linear branches. The cytology was interpreted as a probable histiocytic inflammatory response to the unidentified foreign material with histiocytic sarcoma as a differential diagnosis. Histopathologic evaluation of the splenic mass resulted in a diagnosis of histiocytic sarcoma. The branching material stained positively for both iron and calcium, indicating that the material was compatible with Gamna‐Gandy bodies present secondary to tumor‐associated hemorrhage and the formation of calcium–iron complexes.  相似文献