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1.
Samples of marine pleuston were collected from the sea-surface along considerable sections of the track of Eye of the Wind during its 2-year circumnavigational expedition 'Operation Drake' from November 1978 to October 1980. One hundred and eleven of the tow samples contained insects of the genus Halobates . They were assigned to four oceanic species: H. micans, H. sericeus, H. germanus and H. splendens; two coastal species: H. maculatus, H. princeps, and one undescribed species. Various development stages of the oceanic species were found. The locations, time of collection and surface temperatures where sea-skaters were collected are tabulated. Distributional boundaries and population densities of the oceanic species collected are discussed.  相似文献   
2.
We previously identified heme oxygenase 1 (HO-1) as a specific target of miR-155, and inhibition of HO-1 activity restored the capacity of miR-155 -/- CD4+ T cells to promote antigen-driven inflammation after adoptive transfer in antigen-expressing recipients. Protoporphyrins are molecules recognized for their modulatory effect on HO-1 expression and function. In the present study, we investigated the effect of protoporphyrin treatment on the development of autoimmunity in miR-155-deficient mice. MiR-155-mediated control of HO-1 expression in promoting T cell-driven chronic autoimmunity was confirmed since HO-1 inhibition restored susceptibility to experimental autoimmune encephalomyelitis (EAE) in miR-155-deficient mice. The increased severity of the disease was accompanied by an enhanced T cell infiltration into the brain. Taken together, these results underline the importance of miR-155-mediated control of HO-1 expression in regulating the function of chronically-stimulated T cells in EAE.  相似文献   
3.
用云南山楂(Crataegus scabrifolia(Franch.)Rehd.)成年树茎尖和实生芽两种不同发育阶段的材料为外殖体,诱导它们休眠芽萌动,丛生芽条并诱导芽条生根。实验结果如下:1.以成年态的云南山楂侧芽为外植体,培养在附加IAA 0.1—0.5mg/l+6-BA 1-2mg/l的MS培养基上可诱导芽的萌发;将芽继代培养在附加0.5—1mg/l 6-BA的SH或MS培养基上,40天后芽数增殖4—6倍;将芽条截下置于1/2MS培养基上,附加不同浓度的IAA或IBA,可得到50—80%的生根率。2.以实生芽为外殖体,在相同条件下,则20天后芽数增殖便可获4—6倍;98%以上生根。结果表明:云南山楂的幼年态要比成年态易脱分化和再分化。  相似文献   
4.
香荚兰种子的无菌萌发试验   总被引:1,自引:0,他引:1  
香荚兰(Vanilla planifolia)是兰科、香荚兰属植物,主产于湿热地区。香荚兰的果实是国际上重要的食用香料的原料。大约在1960年,我国引入香荚兰试栽。生产上,通常用扦插法繁殖;但如用种子繁殖,虽然结实较晚(约7至8年开始结实,较扦插苗晚4—5年),但结实期长,盛产期可维持约15年。而且,在杂交育种过程中,一定要用种子繁殖。  相似文献   
5.
Restructured beef steaks, formulated with different beef particle sizes, fat content and binder levels, were evaluated with selected marketing factors by 30 consumers. Conjoint analysis was applied to consumers’hedonic scores and statement of purchase intent for raw and cooked steaks. Product preference, packaging and brand had significant (P < 0.05) impacts on hedonic scores for raw products. Price was an additional important factor in purchase intent. Parcooked products, only product preference was important for both hedonic rating and purchase intent. When products were not present, conjoint measurement indicated that nutritional information, price and brand influenced (P < 0.05) hedonic responses.  相似文献   
6.
本文比较了不同酶液、渗透压稳定剂、酶解温室及菌丝培养基成份等因素对木耳属(Auricularia)中木耳(Auricularia auricula)和毛木耳(Auricularia polytricha)菌丝释放原生质体的作用及影响。用0.5%纤维素酶加0.5%蜗牛酶的混合酶液,以0.6M的MgSO_4为稳定剂,在34℃下可自两种菌丝体获得大量原生质体。对原生质体再生条件的研究表明,纤维二糖和菌丝体培养物浸提物对再生有明显促进作用,再生率达20%左右。本文还用VBL型荧光增白剂观察了菌丝脱壁以及原生质体细胞壁再生的过程。  相似文献   
7.
取食雄蜂蛹粉对龟纹瓢虫和异色瓢虫卵黄发生的影响   总被引:1,自引:1,他引:0  
沈志成  龚和 《昆虫学报》1992,35(3):273-278
本文比较了龟纹瓢虫Proylea japonica和异色瓢虫Harmonia axyridis取食蚜虫和取食雄蜂蛹粉时的卵黄发生情况.当取食雄蜂蛹粉时,体内卵黄蛋白出现迟,积累速度慢,产卵前期长.但用保幼激素类似物ZR512点滴处理后则能达到与食蚜对照相当的水平.ZR512对取食雄蜂蛹粉瓢虫的作用显著大于取食岈虫者.进一步的研究表明,ZR512能促进这两种瓢虫取食雄蜂蛹粉,但对成虫的体重没有明显的影响.因此推论,雄蜂蛹粉基本能够满足这两种瓢虫生殖的营养需要,但对其内分泌有一定的影响,使瓢虫处于类似生殖滞育的状态.本文根据不同食物条件对卵黄蛋白发生的影响不同,建议用卵黄蛋白的量作为生理指标,以快速初步筛选和评估人工饲料.  相似文献   
8.
粘虫幼虫血淋巴中的凝集素   总被引:5,自引:0,他引:5  
朱呈智  孙勇 《昆虫学报》1992,35(4):399-404
粘虫Mythlmna separata Walker幼虫血淋巴中含有凝集某些脊椎动物红细胞的凝集素,凝集活性可被乳糖、岩藻糖或神经氨酸抑制.用CNBr-sepharose 4B 进行亲和层析从血淋巴中分离的凝集素成分比较复杂,聚丙烯酰胺凝胶电泳显示三条区带,SDS聚丙烯酰胺凝胶电泳出现6个亚基,亚基分子量分别为71000、65000、56000、35000、33000及31000道尔顿.  相似文献   
9.
Abstract.
  • 1 A case study is presented of the autumn migration of the brown planthopper, Nilaparvata lugens (Stål), in the area of Nanjing in the People's Republic of China. The study was made using a high frequency (8 mm wavelength) radar and a net suspended from a kytoon.
  • 2 The observations confirmed that long-distance return migrations occur in China in mid and late September, with N.lugens being carried on the prevailing north-easterly wind towards the autumn infestation and overwintering areas of the species.
  • 3 After mass take-off in the late afternoon or at dusk, the migrants flew for several hours during the evening, often in a dense layer which formed at heights between about 400 and 1000m above ground. These layers often had well-defined ceilings corresponding to an air temperature of about 16°C. The migration height was above the top of the surface temperature inversion, i.e. the migrants did not fly at the height of the warmest air.
  • 4 The dense layer concentrations overflying the radar were backtracked to source areas up to 240 km away in the north-east of Jiangsu Province. Planthoppers observed emigrating from the Nanjing area would reach areas in south Anhui Province or north Jiangxi Province if they flew for 12 h.
  • 5 There was a second period of mass take-off at dawn. Insect layers sometimes formed but did not last longer than 1–2h.
  • 6 The present results were strikingly different from those previously observed in the dry season in the Philippines, where migratory flight durations were largely confined to periods of about 30min at dusk and dawn.
  • 7 Our observations are discussed in relation to the equator-wards return migrations undertaken in autumn by other insect species, and the importance of these migrations for the maintenance of long-flying genotypes in the overwintering populations is considered.
  相似文献   
10.
本工作用二种离子通道阻断剂四乙胺(TEA)和河豚毒素(TTX)来研究 Na~+、K~+通道的改变对大鼠黄体细胞孕酮生成的影响。10~(-3)mol/L 的 TEA 或 TTX 均使孕酮分泌量显著增加,而这种促进效应可被酪氨酸(Tyr)完全阻断。Tyr 对 TEA 或 TTX 与 hCG 联合所引起的孕酮分泌也有抑制作用。上述实验说明跨黄体细胞内外的 K~+和 Na~+浓度差与孕酮分泌有关。  相似文献   
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