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131.
Pseudomonas solanacearum (Smith) was consistently isolated from the wilted plants of Casuarina equisetifolia. The isolate gave positive reaction to oxidase, catalase and gas production from nitrate and negative reaction for arginine dihydrolase and acid was produced from various carbohydrates. Wilt produced on tomato, egg plant and capsicum indicated that the pathogen belongs to Race I and Biovar III of P. solanacearum which is a new record from India.  相似文献   
132.
This paper explores the influence over time of past policies on people’s attitudes towards the use of forestland in Bangladesh. The discourses of the attitudes of people were captured from the observed social tradition towards forest resources. Forests were reserved systematically and solely through the Forest Department. The conservation processes were not participatory, and rights and tenure were strictly controlled. People were socially excluded and alienated from the forest, and the socio-political factors stimulated negative attitudes among people. Forests were considered to be government property, and therefore managing forests was the responsibility of the government. People only used forest resources to meet their own requirements, either with formal permission or illegally. This situation continued even after the independence of Bangladesh in 1971. As a result, the forests of Bangladesh have been degraded heavily in recent decades.  相似文献   
133.
Micromechanics of wood subjected to axial tension   总被引:5,自引:0,他引:5  
Summary The behaviour of a small group of wood fibers of Sitka spruce during tensile loading is investigated. The load-extension curves for both early and late wood fibers consist of three distinct segments. The first segment is almost a straight line, at some stage of loading a yield point is observed. Beyond this point the specimen becomes less stiff and undergoes a large, mainly irreversible deformation. As the load is increased further, the curve exhibits the third segment showed by a significant change in slope. These curves look different from those obtained on thick specimens. In this respect, the behaviour of a thin wood specimen subjected to cyclic type tensile loading along its longitudinal direction is also illustrated. Based on wood microstructure, a model is presented to interpret the evolution of the Young's modulus of a wood fiber during tensile loading. The model considers wood as an assembly of cylindrical fibers pasted together in a longitudinal direction. We have assumed the cell wall to comprise only an S2 layer made of a composite material consisting of a lignin and hemicellulose matrix reinforced by helical microfibrils along the fiber. Furthermore, it is assumed that the microfibril angle a in the S2 layer is not uniform along the fiber axis and matrix degradation occurs in the zones where the microfibril angles are bigger. The validity of this assumption is verified by using holographic interferometry to visualize the displacement field of the specimen's surface under tension.The work reported in this paper is supported by a grant from the Swiss National Science Foundation, and its support is gratefully acknowledged  相似文献   
134.
Kumar A  Ali M 《Fitoterapia》2000,71(2):101-104
A new steroidal alkaloid, named antidysentericine, has been isolated from the seeds of Holarrhena antidysenterica and characterized as 3 beta-dimethylaminocon-5-enin-18-one (1).  相似文献   
135.
Wildfires in recent years have resulted in degradation and damage to the Hyrcanian forest ecosystems in Northern Iran.This study was carried out to investigate fire damage to trees and changes in regeneration in early-season growth after wildfires in the Golestan Province.For this purpose,a random sampling plan was used,with 60 circular plots(each plot is 1000 m2) for each stand and 240 circular(25 m2) plots for regeneration within the burned and unburned areas,respectively.In each plot,habitat factors were recorded,including crown canopy percentage,forest stratum,herb-layer cover percentage,species,diameter at breast height,tree and regeneration quality,and quantity of seedlings and saplings.Our results showed that bark is an important factor for fire resistance in Hyrcanian forests.The Persian ironwood and European yew has the highest and lowest fire resistance;as broad leave species are more resistant than needle leaf species.Density of regeneration in unburned area was higher than burned area,and statistical analysis showed significant differences for all species between two areas.Fire effects on sapling were different among species which indicates sapling has different resistance to fire.Forest floor fuel,season,stand composition and microclimate have more effects on fire severity while environmental factors,regeneration and management practices shaping future composition stands.  相似文献   
136.
Tropical Animal Health and Production - This study was conducted to evaluate the male effect on the manifestation of estrus and feeding behavior of Afshari ewes during their breeding season. The...  相似文献   
137.
Inhibins are members of the TGFβ superfamily and act as suppressors of follicle stimulating hormone (FSH) secretion from pituitary glands via a negative feedback mechanism to regulate folliculogenesis. In this study, the INHBB gene was knocked down by three RNAi-Ready pSIREN-RetroQ-ZsGreen vector- mediated recombinant plasmids to explore the effects of INHBB silencing on granulosa cell (GC) cell cycle, apoptosis and steroid production in vitro. Quantitative real-time polymerase chain reaction, Western blot, flow cytometry and ELISA were performed to evaluate the role of INHBB in the mouse GC cell cycle, apoptosis and steroid production in vitro. The results showed that the relative mRNA and protein expression of INHBB in mouse GCs can be significantly reduced by RNAi with pshRNA-B1, pshRNA-B2 and pshRNA-B3 plasmids, with pshRNA-B3 having the best knockdown efficiency. Downregulation of the expression of INHBB significantly arrests cells in the G1 phase of the cell cycle and increases the apoptosis rate in GCs. This was further confirmed by downregulation of the protein expressions of Cyclin D1, Cyclin E and Bcl2, while the protein expression of Bax was upregulated. In addition, specific downregulation of INHBB markedly decreased the concentration of estradiol and progesterone, which was further validated by the decrease in the mRNA levels of CYP19A1and CYP11A1. These findings suggest that inhibin βB is important in the regulation of apoptosis and cell cycle progression in granulosa cells. Furthermore, the inhibin βB subunit has a role in the regulation of steroid hormone biosynthesis. Evidence is accumulating to support the concept that inhibin βB is physiologically essential for early folliculogenesis in the mouse.  相似文献   
138.
This experiment was conducted to evaluate the effects of different levels of sweet orange (Citrus sinensis) peel extract (SOPE) on humoral immune system responses in broiler chickens. Three hundred 1‐day broilers (Ross‐308) were randomly allocated to treatments varying in supplemental SOPE added in the drinking water. The experimental groups consisted of three treatments fed for 42 days as follows: a control treatment without feed extract, a treatment containing 1000 ppm of SOPE and a treatment containing 1250 ppm of SOPE. All treatments were isocaloric and isonitrogenous. Broilers were vaccinated with Newcastle disease virus (NDV), avian influenza (AI), infectious bursal disease (IBD) and infectious bronchitis virus (IBV) vaccines. Antibody titer response to sheep red blood cells (SRBC) was higher in the group fed 1250 ppm of SOPE (P < 0.05) as well as for immunoglobulin G (IgG) and IgM. Similarly, antibody titer responses to all vaccines were constantly elevated (P < 0.05) by SOPE enrichment in a dose‐dependent manner. Relative weights of spleen and bursa of Fabricius were unaffected by treatments. Dietary SOPE supplementation may improve the immune response and diseases resistance, indicating that it can constitute a useful additive in broiler feeding. Thus, supplying SOPE in rations may help to improve relative immune response in broiler chickens.  相似文献   
139.
Journal of Pest Science - Conflicting views regarding synthetic pesticides include the successful use as pest management tools for agriculture and forestry on one hand and the threats to components...  相似文献   
140.
The effect of a combination of (-)-epigallocatechin-3-gallate (EGCG) with fish oil on intestinal tumorigenesis in Apc (Min/+) mice fed a high-fat diet was investigated in the present study. The combined treatment of EGCG and fish oil for 9 weeks reduced the tumor number by 53% as compared to controls while neither agent alone had a significant effect. Apoptosis was significantly increased in all treatment groups. beta-Catenin nuclear positivity in adenomas from the combination group was lower than control mice, implicating the modulation of Wnt signaling by the combination. Fish oil and the combination significantly reduced prostaglandin E 2 (PGE 2) levels in small intestinal tumors as compared to controls, suggesting modulation of aberrant arachidonic acid metabolism by fish oil. Akt phosphorylation in adenomas was significantly reduced in all treatment groups, which may have contributed to the observed increase in apoptosis. The results indicate that a combination of low doses of EGCG and fish oil can inhibit tumor multiplicity in Apc (Min/+) mice.  相似文献   
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