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1.
布氏田鼠在低温条件下的实验观察   总被引:3,自引:2,他引:1  
施大钊  海淑珍 《兽类学报》1996,16(4):291-296
实验在一20℃的低温下进行. 结果表明:(1)单笼饲养鼠平均存活期为145.9±30.8h其
中幼鼠耐低温力最差, 然后依次为老体组、亚成体组、成体组。除幼体外, 雌鼠的抗寒能力稍高于雄体。(2)饲喂冷篙组比饲喂其它6种牧草在低温下布氏田鼠的存活期显著延长(3)聚集可明显增强对低温的耐受程度。(4)窝草可使巢内温度保持在5-8℃ , 窝巢内层的温度可达15-22 ℃ 。  相似文献   

2.
环境条件对水网藻(Hydrodictyon reticulatum)生长的影响   总被引:13,自引:0,他引:13  
研究了温度、光照强度及N、P浓度与水网藻生长的关系.结果表明,水网藻能在较大的温度范围(10~31℃)、光照强度(300~5300Lx)和N浓度(1.0~84.0mg·L-1)和P浓度(0.05~3.72mg·L-1)等条件下生长.最适生长温度为25℃,当光照强度大于1300Lx,N、P含量分别为16.8~50.4和0.744~2.23mg·L-1时,水网藻生长良好.低温有利于水网藻忍耐低光照和低N低P.  相似文献   

3.
温度对美洲斑潜蝇发育,存活和繁殖的影响   总被引:10,自引:1,他引:9  
探讨了在光照周期为14L10D、R.H.为70 % ±5 % 的恒温(12 ~35 ℃) 条件下美洲斑潜蝇的发育、繁殖和存活,求得美洲斑潜蝇世代的发育起点温度与有效积温分别为8 .77 ℃和295 .69 日度,给出了温度与各虫态发育速率间的函数关系.20 ~27 .5 ℃时存活率较高,死亡主要发生在蛹期,35 ℃下蛹不能羽化.成虫寿命随温度的升高而缩短; 种群增长指数于27 .5 ℃时达到最高.  相似文献   

4.
温度对射干种子萌发影响的试验研究   总被引:7,自引:0,他引:7  
对射干〖elamcanda hinensis(L.)DC.〗种子萌发中温度的影响进行了研究,结果表明射干种子的萌发温度为5~30℃,恒温条件下的萌发率不高,且持续时间较长,低温或高温向15~25℃变温可以提高种子萌发率。15~25℃向向低温高温变温萌发率下降。15~25℃之间的变温萌发率变化不大。昼夜温度周期30℃向人氏温或高温变温萌发率下降,15~25℃之间的变温萌发率变化不大。昼夜温度周期30  相似文献   

5.
樊晓丽  雷焕宗  林植华 《生态学报》2012,32(17):5574-5580
体温是影响变温动物表现的最重要生理学变量。检测了国家二级保护动物虎纹蛙的雌性亚成体、雄性亚成体、幼体和蝌蚪这4个发育阶段的选择体温和热耐受性。单因子方差分析表明,虎纹蛙选择体温、耐受低温、耐受高温和温度耐受范围的组间差异均显著,幼体的选择体温(24.13℃)显著低于雌性亚成体(28.06℃)、雄性亚成体(29.27℃)和蝌蚪(28.23℃),雌性亚成体、雄性亚成体和蝌蚪之间差异不显著;幼体的耐受低温(13.85℃)显著高于雌性亚成体(11.27℃)、雄性亚成体(10.84℃)和蝌蚪(10.74℃),雌性亚成体、雄性亚成体和蝌蚪之间差异不显著;幼体具有显著低的耐受高温(35.48℃)、蝌蚪具有显著高的耐受高温(43.31℃),雌性亚成体(39.55℃)和雄性亚成体(39.02℃)的耐受高温差异不显著;幼体(21.62℃)具有显著小的温度耐受范围、蝌蚪(32.58℃)具有显著大的温度耐受范围,雌性亚成体(28.28℃)和雄性亚成体(28.18℃)的温度耐受范围差异不显著。虎纹蛙幼体和亚成体体温和水温之间在降温速度和升温速度的相关关系均显著。用回归剩余值去除水温变化速度对体温变化的影响,双因子方差分析(降温和升温速度为重复检验设置)表明,幼体的体温变化速度显著大于亚成体,两性亚成体间差异不显著;温度变化类型(降温和升温)和两因子的交互作用对体温变化的影响不显著。基本热生态位分离和体温调节能力的发育限制是形成上述现象的最可能的原因。  相似文献   

6.
角质蛋白酶固态发酵工艺及酶解条件的研究   总被引:2,自引:0,他引:2  
张道海  李楠 《生物技术》1994,4(4):11-14
曲霉A28-8是一株优良的角蛋白酶分泌突变菌株。其最佳固体发酵培养基为:20%羽毛粉,80%麸皮和微量无机氮(每克培养基中加0.5mg);最适产酶条件为:起始pH7.5~8.0,温度28℃~30℃,时间为60~70小时,酶活高达2500KU/g曲;最适酶解条件为pH7.0~9.0,温度45℃~50℃。  相似文献   

7.
两种独行菜种子萌发生理特性研究   总被引:2,自引:0,他引:2  
孟君  李群  李冠 《生物技术》2008,18(2):32-35
以两种在新疆具有代表性的十字花科独行菜属早春短命植物抱茎独行菜(Lepidium perfoliatum Linnaeus)和独行菜(Lepi-dium apetalum Willd)为材料,研究(光照、温度、外源激素ABA处理)对其种子萌发的影响。结果:两种独行菜种子萌发对光照不敏感;抱茎独行菜种子萌发的温度范围广,在0℃~25℃之间都可萌发,而独行菜种子则在低温下(0℃、4℃)不萌发,其萌发温度范围为10℃~25℃。两种独行菜种子对低温胁迫表现出不同的耐受性;0℃、4℃下,在培养基中加入不同浓度的ABA,对抱茎独行菜种子萌发有抑制作用。  相似文献   

8.
光照和温度对高原鼠兔褐色脂肪组织产热特征的影响   总被引:6,自引:2,他引:4  
测定了高原鼠兔( Ochotona curzoniae) 在驯化2 周后( 分4 种处理: 23 ℃,16 L:8 D; 23 ℃, 8 L:16 D; 5℃,16 L:8 D 和5 ℃, 8 L:16 D) 褐色脂肪组织(BAT) 的蛋白含量、线粒体蛋白含量和细胞色素c 氧化酶活性的变化。结果表明, 低温或短光照可刺激这些指标的增加; 最高值出现在低温加短光照组。说明在季节性驯化过程中, 光照和温度协同作用, 以诱导动物的产热调节。这与高原鼠兔群居性差、不筑巢的行为习性、栖息于开阔的矮蒿草草甸以及高寒地区的昼夜温差较大、气候多变等因素有关。  相似文献   

9.
用太行花(Taihangia rupestris Y汃etLi)试管花进行雌雄蕊发育的温度试验表明:1. 雄蕊和雌蕊的发育对温度的要求是不同的,雄蕊发育的最适温度范围偏低,接近于1~6 ℃,高于18 ℃雄蕊全部败育。雌蕊发育的最适温度范围偏高,约6~26 ℃,低于3 ℃,大部分雌蕊在分化早期停止发育。2. 由高温引起的雄蕊败育过程始于雄蕊原基时期,这个过程一旦启动,雄蕊败育将不会因重新将它转入低温而逆转。通过控制实验温度获得了单性雄花(1~3 ℃)、单性雌花(6~26 ℃)和两性花(6~12 ℃)。实验结果将为性别控制和雄性不育研究开拓新思路  相似文献   

10.
2005年调查若尔盖湿地的高原林蛙(Rana kukunoris)和岷山蟾蜍(Bufo minshanicus)的日活动节律,发现阳光充足时两栖类的活动性明显高于多云天气;高原林蛙成体、亚成体、岷山蟾蜍亚成体活动的最低气温为0℃、2℃、8℃;高原林蛙亚成体日活动高峰为中午12:30左右,岷山蟾蜍亚成体日活动高峰为下午15:30左右;高原林蛙亚成体在草地、林地、河边均有一定数量个体活动,岷山蟾蜍亚成体主要集中在河边活动。在若尔盖地区,两栖类可能主要是采用晒太阳(basking)的行为来适应高海拔环境;高原林蛙成体对温度的耐受性比亚成体高,亚成体比岷山蟾蜍亚成体高;高原林蛙与岷山蟾蜍的亚成体在活动时间与活动生境上存在差异,可能是减少种间竞争的途径之一。  相似文献   

11.
正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases  相似文献   

12.
Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.  相似文献   

13.
The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.  相似文献   

14.
15.
Highlights
1. The N-terminal tail of histone H3 is specifically cleaved during EV71 infection.
2. Viral protease 3C is identified as a protease responsible for proteolytically processing the N-terminal H3 tail.
3. Our finding reveals a new epigenetic regulatory mechanism for Enterovirus 71 in virus-host interactions.  相似文献   

16.
Rasmussen’s encephalitis (RE) is a rare pediatric neurological disorder, and the exact etiology is not clear. Viral infection may be involved in the pathogenesis of RE, but conflicting results have reported. In this study, we evaluated the expression of both Epstein-Barr virus (EBV) and human herpes virus (HHV) 6 antigens in brain sections from 30 patients with RE and 16 control individuals by immunohistochemistry. In the RE group, EBV and HHV6 antigens were detected in 56.7% (17/30) and 50% (15/30) of individuals, respectively. In contrast, no detectable EBV and HHV6 antigen expression was found in brain tissues of the control group. The co-expression of EBV and HHV6 was detected in 20.0% (6/30) of individuals. In particular, a 4-year-old boy had a typical clinical course, including a medical history of viral encephalitis, intractable epilepsy, and hemispheric atrophy. The co-expression of EBV and HHV6 was detected in neurons and astrocytes in the brain tissue, accompanied by a high frequency of CD8+ T cells. Our results suggest that EBV and HHV6 infection and the activation of CD8+ T cells are involved in the pathogenesis of RE.  相似文献   

17.
18.
Shen  Jia-Yuan  Li  Man  Xie  Lyu  Mao  Jia-Rong  Zhou  Hong-Ning  Wang  Pei-Gang  Jiang  Jin-Yong  An  Jing 《中国病毒学》2021,36(1):145-148
正Dear Editor,Chikungunya virus (CHIKV), an arbovirus in the family of Togaviridae, genus Alphavirus, is transmitted by the A.aegyptii or A. albopictus mosquito, and causes disease in humans characterized by fever, rash, and arthralgia (Silva and Dermody 2017; Suhrbier 2019). It was first reported in 1953 in Tanzania, and caused only a few outbreaks and sporadic cases in Africa and Asia in last century. However, in the epidemic in 2004, CHIKV acquired mutations that conferred enhanced transmission by the A. albopictus mosquito(Schuffenecker et al. 2006). Since then, it has successively caused outbreaks in Africa, the Indian Ocean, South East Asia, the South America, and Europe (Zeller et al. 2016).  相似文献   

19.
In conclusion, the novel visual RT-LAMP assay is a simple, rapid, and sensitive approach for detection of SARS-CoV-2, and it is ready for application in primary care and community hospitals or health care centers, and even patients' own houses in response to the current SARS-CoV-2 epidemic because the assay does not require sophisticated equipment and skilled personnel. Furthermore, it is also ready to be used in fields for screening samples from wild animals and environments to facilitate the identification of potential intermediate hosts that mediate the cross-species transmission of SARS-CoV-2 from bats to humans.  相似文献   

20.
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