Some Physical Properties of Linseed   总被引：1，自引：0，他引：1  

Kemal aatay Selvi  Yunus P&#x;nar  Elin Yeilolu 《Biosystems Engineering》2006,95(4):607-612

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两种塑料暖棚猪舍的应用效果观测   总被引：1，自引：0，他引：1  

侯正录  杨占魁 《家畜生态》2002,23(3):17-18

在青海省乌兰县舍外温度－6．30℃条件下，选用40头荣昌猪分作2组，每组20头，在自行设计的半开放－封闭式多用塑料暖棚猪舍与常用简易塑料暖棚猪舍内开展对比试验。结果表明，前者可显著提高舍内温度，降低舍内湿度，且育猪增重效果明显。  相似文献   

Addendum     

E. Gruys  M. Castaño 《Veterinary research communications》1977,1(1):276-276

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Biological features and life table parameters of the mealy plum aphidHyalopterus pruni on different apricot cultivars     

M. S. Özgökçe  R. Atlıhan 《Phytoparasitica》2005,33(1):7-14

Development, survival, reproduction rate, and population growth parameters of the mealy plum aphidHyalopterus pruni (Geoffroy) (Hom.: Aphididae) were evaluated on four different apricot cultivars (Tyrinte, Sakıt, Colomer, and Bebeco) under field conditions in the Van region of Turkey. Experiments were carried out on exterior leaves of trees, 1.5–2 m above the ground. Plexiglas clip-cells (25×6 mm) with the upper side covered by muslin were used in the experiments. The mealy plum aphid performed better on Tyrinte than on the other cultivars tested. The fastest development time (first instar to adult; 9.4 days), highest daily reproduction rate (2.6 offspring/aphid/day), and highest total fecundity (48.1 offspring/aphid) were obtained on Tyrinte. The intrinsic rate of increase — a good indicator of the growth potential of a population — of individuals fed on Tyrinte was significantly greater than that of individuals fed on cvs. Colomer and Bebeco. While mean generation times (T _o ) of populations on different cultivars were close to each other, the net reproductive rate was the highest (29.45 offspring/aphid/generation) on Tyrinte and the population doubling time on Tyrinte was 18.7%, 25.2% and 26.3% faster than those of individuals on other cultivars tested. The results obtained in this study indicated that Tyrinte appeared to be the most susceptible to the mealy plum aphid among the cultivars tested. http://www.phytoparasitica.org. posting Nov. 23, 2004.  相似文献   

Growth loss of Lebanon cedar (Cedrus libani) stands as related to periodic outbreaks of the cedar shoot moth (Dichelia cedricola)     

Serdar Carus  Mustafa Avcı 《Phytoparasitica》2005,33(1):33-48

An outbreak ofDichelia cedricola (Diakonoff) (Lep.: Tortricidae), the cedar shoot moth (CSM), began in spring 1998 and lasted 3 years. This was the first monitored outbreak of the CSM in Isparta, Turkey. Tree crowns recovered to near normal condition by the middle of each growing season (in early June) during the outbreak. Tree volume and volume element increments were examined throughout the outbreak cycle from 1954 to 2001. In the past, CSM activity in stands of Lebanon cedar (Cedrus libani A. Rich.) was assessed through radial increment analyses. Cedar tree ring chronologies were analyzed for evidence of the CSM. Tree-ring chronologies from nonhost cedar (nondefoliated sample trees) were used to estimate potential growth in the host cedar (defoliated sample trees) during current and past outbreaks; all trees selected were the same subspecies and varieties. Regional outbreaks of the CSM were identified by synchronous and sustained growth periods of the trees. In 2001, increment cores were collected from 17 host and 16 nonhost dominant or codominant trees and annual radial growth indices from 1954–2001 were calculated for each of two host and two nonhost sample plots. Growth functions were defined as the cumulative sum of radial, height, and volume increment, and were graphically compared between CSM host cedar and nonhost cedar trees. Tree ring evidence suggests that a large-scale outbreak occurred in 1955 (from 1955 to 1966) and a small outbreak occurred in 1985 (1985–1990) and in 1998 (1998-continued) in the study area. The average diameter growth reductions around 1955, 1985 and 1998 were 40%, 46% and 7% of potential, respectively. It was concluded that a narrow latewood band is significant indicator of defoliation by the CSM and the outbreaks appear to be associated with dry winter and spring weather prior to the autumn and winter in which wood feeding occurred. http://www.phytoparasitica.org posting Nov. 24, 2004.  相似文献   

Culture of Differentiated Adult Rabbit Auricular Chondrocytes     

V. Villar  B. Colao  I. Calles‐Venal  J. G. Fernndez‐lvarez  M. Fernndez‐Caso  J. M. Villar 《Anatomia, histologia, embryologia》2005,34(Z1):54-54

Chondrocytes dedifferentiate to a fibroblast‐like phenotype on plastic surfaces. Dedifferentiation is reversible if these cells are then cultured embedded in gels as alginate, agarose or collagen. Chondrocytes cultured in suspension on a non‐adherent surface are also known to form aggregates of differentiated cells. The knowledge of chondrocyte behavior in culture is relevant for tissue engineering purposes. In this report we describe a simple method to culture differentiated or redifferentiated rabbit auricular chondrocytes on plastic surfaces with a stable phenotype. When chondrocyte aggregates formed in suspension are next seeded on plastic surfaces, most of them attach to the plastic as round or polygonal cells, and this morphological differentiation, confirmed by the presence of type II collagen, is stable for long culture periods. We also report that the addition of aggregates to monolayer cultures of dedifferentiated chondrocytes results in their redifferentiation, as is shown by their morphological changes and the synthesis of type II collagen. Therefore, this simple method can be useful for the study of chondrocyte behavior on plastic surfaces and for redifferentiating previously proliferated chondrocytes in tissue engineering techniques. Furthermore, these results demonstrate that, in addition to culture conditions such as cell isolation method or cell‐density, chondrocyte behavior on plastic depends on the presence or absence of aggregates resulting from the dissociation process.  相似文献   

Effects of weed control practices on surface-dwelling arthropod predators in tomato agroecosystems     

Yardım  Erdal N.  Edwards  Clive A. 《Phytoparasitica》2002,30(4):379-386

Weed control, an important practice in agroecosystems to protect crop production, is usually achieved with herbicides. However, these pesticides are expensive, pose potential risks to the environment, may affect some beneficial organisms indirectly, and decrease overall arthropod biodiversity, including pests and their natural enemies, by removing weeds that might act as hosts or shelters for many organisms. The activity density response of important surface-dwelling arthropod predators (ground beetles [Coleoptera: Carabidae], ants [Hymenoptera: Formicidae] and spiders [Arachnida: Araneae]) to herbicides (trifluralin and paraquat), and to two alternative weed management practices (rye straw mulch and mechanical treatment to maintain weeds below threshold levels, in comparison with an untreated check), was assessed using pitfall traps. The mulch treatment had the greatest effect on activity density, reducing the number of predators trapped significantly (P<0.05). Herbicide use resulted in significant (P<0.05) reductions in the activity density of ground beetles. Most predators were trapped in the check plots — which had the highest weed biomass, followed in turn by numbers trapped in the threshold weed control treatment, the full herbicide application and the mulch treatment plots. http://www.phytoparasitica.org posting July 10, 2002.  相似文献   

水稻与稻瘟病菌非亲和性互作中重要防御酶活性变化规律研究   总被引：14，自引：4，他引：14  

贾显禄  王振中  王平 《植物病理学报》2002,32(3):206-213

 选以CO39为背景的水稻抗稻瘟病近等基因系,与稻瘟菌生理小种ZC₁₃(菌株97-151a)组成的3类典型非亲和性互作,以亲和性互作为对照,对各互作中过氧化物酶(POD)、苯丙氨酸解氨酶(PAL)、几丁质酶及β-1,3-葡聚糖酶的活性变化规律进行了系统研究。完全非亲和性互作C101A51/97-151a、高度非亲和性互作C101L AC/97-151a及中度非亲和性互作C104 PKT/97-151a,POD比活性接种后即开始明显升高,48h前达到高峰,升高趋势一直持续到7d完全显症时,幅度基本与各互作非亲和程度呈正相关;亲和性互作CO39/97-151a接种后40 h POD比活性才开始升高,4~6 d达到高峰,峰值也较大。3类非亲和性互作PAL比活性在接种后0 h或16 h开始较明显升高,整个互作中形成3~4个较明显的峰;亲和性互作中PAL比活性一直明显下降。3类非亲和性互作外切几丁质酶比活性接种后即开始升高,基本一直保持升高趋势,在40 h前幅度较大,并形成1~3个较高的峰;亲和性互作外切几丁质酶比活性接种后即开始大幅度升高直至完全显症,48h后幅度远高于非亲和性互作。3类非亲和性互作β-1,3-葡聚糖酶比活性在24 h内开始较明显升高,在48h前形成2~3个较明显的峰;亲和性互作在接种后β-1,3-葡聚糖酶比活性即开始升高,在48h后显著高于非亲和性互作。讨论了POD、PAL、几丁质酶及β-1,3-葡聚糖酶参与水稻抗稻瘟病的可能性。  相似文献   

Bayesian comparison of test-day models under different assumptions of heterogeneity for the residual variance: the change point technique versus arbitrary intervals     

P. López-Romero  R. Rekaya  M. J. Carabaño 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2004,121(1):14-25

Test‐day milk yields from Spanish Holstein cows were analysed with two random regression models based on Legendre polynomials under two different assumptions of heterogeneity of residual variance which aim to describe the variability of temporary measurement errors along days in milk with a reduced number of parameters, such as (i) the change point identification technique with two unknown change points and (ii) using 10 arbitrary intervals of residual variance. Both implementations were based on a previous study where the trajectory of the residual variance was estimated using 30 intervals. The change point technique has been previously implemented in the analysis of the heterogeneity of the residual variance in the Spanish population, yet no comparisons with other methods have been reported so far. This study aims to compare the change point technique identification versus the use of arbitrary intervals as two possible techniques to deal with the characterization of the residual variance in random regression test‐day models. The Bayes factor and the cross‐validation predictive densities were employed for the model assessment. The two model‐selecting tools revealed a strong consistency between them. Both specifications for the residual variance were close to each other. The 10 intervals modelling showed a slightly better performance probably because the change point function overestimates the residual variance values at the very early lactation.  相似文献   

Evaluation of Olive Cultivars for Resistance to Verticillium dahliae     

F.J. López-Escudero  C. del Río  J.M. Caballero  M.A. Blanco-López 《European journal of plant pathology / European Foundation for Plant Pathology》2004,110(1):79-85

Resistance of 23 important olive cultivars to Verticillium dahliae has been evaluated in four experiments under controlled conditions. Nine-month-old nursery olive plants were inoculated with a cotton non-defoliating (ND) (V4) or a cotton defoliating (D) (V117) isolate of V. dahliae. Resistance was evaluated by assessing symptom severity using a 0–4 rating scale and estimating the area under disease progress curves. The percentage of plants killed and of those which recovered from the disease were used as additional parameters for including a particular cultivar into a defined category. Most of the evaluated cultivars were susceptible, although at different levels, to both isolates of V. dahliae. All cultivars were more susceptible to the D pathotype than to the ND one. A group of 11 cultivars, including several important Spanish cultivars, were susceptible or extremely susceptible to both pathotypes of V. dahliae. A second group showed differences of resistance depending on the pathotype used. They were susceptible or extremely susceptible to the D pathotype but resistant or moderately susceptible to the ND one. Finally, 'Frantoio', 'Oblonga' and 'Empeltre' were moderately susceptible to the D isolate of V. dahliae and resistant to the ND one. The resistance of 'Empeltre' was evident by the plant ability to recover from infection with either isolates. 'Empeltre' is considered to be a valuable cultivar for inclusion in breeding programmes for resistance to Verticillium wilt.  相似文献