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41.
Summary Color notations of dorsal pelage were analyzed in 451 adult subterranean mole rats, comprising 19 populations and 4 chromosomal species (2n=52, 54, 58 and 60) of the Spalax ehrenbergi superspecies in Israel. In addition, the color notations of soil samples from the collection sites were measured. In an attempt to evaluate the degree of correlation between pelage color of mole rats and the local soil color, each color was compared both macro- and microgeographically. The macrogeographic comparisons were among populations of the 4 chromosomal species, and the microgeographic comparisons were among pairs of geographically neighboring subpopulations which occur under similar climatic conditions but differ in soil type and color. The results indicate that 1. no differences in pelage color notation exist between the sexes; 2. pelage of mole rats is generally characterized by an over-all grayish color, but its shades vary regionally and locally in accordance with varying soil color; 3. a positive correlation was found between pelage and local soil colors in the macrogeographic analysis and this correlation was verified in a microgeographic comparison; 4. specimens from populations of the northern chromosomal species (2n=52, 54) mainly inhabit terra rossa and basalt soils, respectively, with reddish brown tones, and they tend to have a more reddish shade, whereas animals from the central species (2n=58), which inhabits mainly dark soils including alluvial clays, terra rossa and brown rendzina and the souther species 2n=60, which occurs mainly in light soil types such as pale rendzina, sandy loams and loess, tend to have a more yellowish shade. The general appearance of specimens from 2n=58 was dark gray while that of 2n=60 specimens was light gray; 5. mole rats living in xeric environments (particularly 2n=60, but also 2n=54) are lighter than those which live in mesic environments (2n=52, 58). The results support the conclusion that pelage color of strictly subterranean mole rats is subject to selection pressures of overground predation of disharmonious types with their background soil color. The possibility that the pelage color variation and patterns also contributes to better thermoregulation while mole rats are above ground is discussed.  相似文献   
42.
小地老虎变态期脂肪体变化及保幼激素类似物的影响   总被引:1,自引:0,他引:1  
本文对小地老虎Agrotis ypsilon(Rottemberg)从四龄幼虫开始经预蛹和蛹的变态期及羽化为成虫后的脂肪体出现的超微结构变化,蛋白质含量的变动,以及蛋白质颗粒的形成和消失过程,进行了系统观察和组织化学分析。结果表明:(1)在幼虫期的后期,脂肪体扩大成宽带状,细胞体积增大的同时出现双核和多核。进入预蛹期,细胞内开始出现嗜碱性“蛋白质颗粒”,血细胞吞噬部分脂肪体细胞。蛹龄一天时,脂肪体转变成块状,细胞内充满大型蛋白质颗粒。在蛹龄5—10天内,“幼虫脂肪体”逐步崩解,围膜及细胞膜消失。至蛹龄12天时转变为预成虫,脂肪体细胞重新出现,并以气管分支为中心聚合成花朵状圆球体,再组成串状“成虫脂肪体”,仍充满蛋白质颗粒。幼虫期发达的粗面内质网和线粒体,至预蛹期则衰变成几种类型的蛋白质颗粒。(2)六龄幼虫在1—5日龄期间,每克脂肪体的蛋白质含量稳定在7.1—8.4毫克之间,随后逐步升高,至预蛹期达16.3毫克的峰值。蛹初期,雄蛹和雌蛹的含量分别增高到预蛹期的1.63和2.4倍。但在蛹龄2—8天内迅速下降到六龄幼虫期的水平。至蛹龄9—13天时间(包括预成虫),含量又突然猛增,雌蛹尤为显著。蛹期脂肪体细胞充满着的几种蛋白质颗粒,在羽化为成虫后的24小时内全部消失。在六龄幼虫期用保幼激素类似物ZR-515(20微克)作体壁处理,可使幼虫期延长4天,并使九日龄幼虫的脂肪体仍保持幼虫型状态。  相似文献   
43.
The importance of creatine kinase (E.C. 2.7.3.2) in endocrine tissues has been generally overlooked. Using a specific radiometric assay, we have demonstrated the existence of CK in the Brockmann body (principal islet) of the Coho salmon. We have purified this protein from insular tissue and concurrently purified CK from brain and muscle of the salmon. Purification characteristics, immunological cross-reactivity, and N-terminal sequence analysis have demonstrated that the predominant cytosolic CK from the Brockmann body is indistinguishable from the BB (brain) isoenzyme. Immunocytochemical studies indicated that the enzyme resides in the endocrine parenchyma. Phosphocreatine may serve as a reservoir of energy in the islet and augment its capacity to secrete hormones. The induction of CK-BB in the islet by other hormones could influence the secretion of insular hormones. Interorgan flux of the substrate creatine may be an undescribed mechanism of physiological regulation.  相似文献   
44.
Feeding of aflatoxin B1 at the rate of 0.5 ppm to young Japanese quail resulted in significant (p<0.01) decrease in body weight gain that became apparent on the third week. There was no significant difference in the mean values of haemoglobin, packed cell volume and total erythrocyte counts of quail chicks given aflatoxin B1 in feed in comparison to those fed on a similar diet without aflatoxin. However, the total leucocyte count revealed an increase on the third week which was due to an increase in the percentage of heterophils and decrease in lymphocytes.  相似文献   
45.
The life history of three populations ofProtohermes grandis and two populations ofProtohermes immaculatus (Megaloptera: Corydalidae) was compared. In general, the larvae lived in stream riffles for 2 years and the adults appeared in summer. Adult body size differed between these closely related species and also between the populations ofP. grandis. Dwarfism occurred inP. immaculatus, a species that is endemic to the small, isolated island, Amami Island. The population ofP. grandis on Yaku Island, located between Amami Island and the mainland Kyushu, had an intermediate body size between that ofP. immaculatus and the mainland population ofP. grandis. Despite being an insular population,P. grandis on Tsushima Island had a similar body size to mainlandP. grandis. In these populations with large adults, some larvae lived in the streams for 3 years. The size distribution of benthic animals, which are the prey available toProtohermes larvae, differed between the streams studied. The density of large prey was lowest on Amami Island, intermediate on Yaku Island, and highest on the mainland and Tsushima Island. Different size distributions of available prey may be caused by the differences of benthic fauna; most of Ecdyonuridae and Ephemerellidae (large mayflies) and Perlidae (large stoneflies) were not found on Amami and Yaku Islands. Thus, there is a tendency to dwarfism in the populations ofProtobermes inhabiting streams where the density of large prey is low.  相似文献   
46.
Fully adult partial skeletons attributed to Australopithecus afarensis (AL 288-1, “Lucy”) and to Homo habilis (OH 62, “Lucy's child”), respectively, both include remains from upper and lower limbs. Relationships between various limb bone dimensions of these skeletons are compared to those of modern African apes and humans. Surprisingly, it emerges that OH 62 displays closer similarities to African apes than does AL 288-1. Yet A. afarensis, whose skeleton is dated more than 1 million years earlier, is commonly supposed to be the ancestor of Homo habilis. If OH 62, classified as Homo habilis by its discoverers, does indeed represent a stage intermediate between A. afarensis and later Homo, a revised interpretation of the course of human evolution would be necessary.  相似文献   
47.
人体和动物模型的体表物理信息地形图的研究   总被引:1,自引:0,他引:1  
对人体头面、躯干、四肢、耳廓各局部几十个及整个人体等体表部位正、背面等210个部位进行超微弱冷光和温度测量,输入电子计算机,经特殊的自编程序处理,获得十分清晰的,由3000多数据构成的各个局部或人体整体的冷光和温度地形图。 对家兔左、右耳廓、胸腹部、背部都分别观察32个部位的冷光与体表温度,经计算机分析处理,每观察区域获得约由2000个数据构成的精确的冷光、温度地形分市图。并可见不同生理、病理状态及不同病程家兔体表冷光、温度等地形图呈有规律的改变。 此外,我们还编制了以体表左右相应对称部位差值为分析数据进行地形图分析的程序,用以人体和动物体表物理信息对称规律的研究。 本工作以图形的形式显示物理参量在体表的广泛的分布规律,以揭示机体内部的不同生理、病理状态。本方法定位准确、直观醒目,为研究体表信息及机体生命活动规律提供了与逐点直接测量方法相互补充的有益的新手段。  相似文献   
48.
Glycolytic intermediates and related metabolites were measured in the fat body of the American cockroach (Periplaneta americana) to locate the rate-limiting reactions that regulate glycolysis during the action of the corpus cardiacum (CC) in vitro.
1.  The concentrations of glucose 1-phosphate, fructose 6-phosphate, and fructose 1,6-bisphosphate were approximately doubled after 30 min treatment with CC extract, whereas that of glucose 6-phosphate increased more than four-fold. Slightly lower increases occurred after 10 and 60 min treatment.
2.  Triose phosphates, 2-phosphoglyceric acid, phosphoenolpyruvate and pyruvate were unaffected by CC extract.
3.  Glycerol 3-phosphate, which is 20\2-200 times more concentrated than any of the other measured metabolites in the unstimulated tissue, is increased more than two-fold by CC extract.
4.  NAD, NADP, and ATP were not significantly affected by CC extract. ADP was increased significantly by the gland extract.
  相似文献   
49.
Abstract.
  • 1 The species number, the abundance per species and the body length of arthropods foraging within the crowns of an over-storey rainforest tree from Australia, Argyrodendron actinophyllum (Sterculiaceae), were investigated by interception trap sampling and restricted canopy fogging. Emphasis was placed upon the interpretation of trap data. Arthropods were trapped continuously day and night, over a 2-year period and the final analyses examined the attributes of 759 species which represented 20,500 individuals.
  • 2 The proportion of‘rare’species (Le. collected once) intercepted was high (35.7%), although lower than in other similar rainforest surveys. Neither the α log-series nor the log-normal distribution could be fitted to the relationship between number of species and number of individuals, since the number of rare species was much higher than predicted and the mode of the distribution could not be identified. The proportion of rare species was higher in fogging collections (452%) than in trap collections.
  • 3 The data are compared with a study of Bornean arboreal beetles, obtained by fogging trees during a single sampling event. Several patterns were common to both data sets. However, the three-dimensional plot of the variables describing the structure of the arthropod community showed a notably rougher surface than in the case of Bornean beetles.
  • 4 Although several factors may complicate the interpretation of the three-dimensional plots, long-term and continuous sampling may alter our perception of complex arthropod communities. This methodology is imperative for a proper understanding of arthropod community structure in rain forests.
  相似文献   
50.
颈动脉内注入腺苷对呼吸,血压和肾交感神经活动的影响   总被引:3,自引:1,他引:2  
苏欣  张万育 《生理学报》1991,43(2):164-170
在33只麻醉家兔,观察了颈动脉内注入腺苷所诱发的平均动脉压、心率,呼吸和肾交感神经活动的变化。结果如下:(1)颈动脉内注入腺苷后,平均动脉压呈剂量依赖性下降;呼吸加快,深度变化不明显,剪断窦神经后注入腺苷,仍引起平均动脉压下降,而呼吸变化消失。(2)隔离的颈动脉窦灌流液内加入腺苷后,平均动脉压下降,心率减慢;颈动脉体(CB)失活后反应消失。(3)将腺苷灌注到颈动脉窦区后,平均动脉压下降,肾交感神经传出放电活动增加,CB 失活或剪断窦神经后,反应消失。由此提示:腺苷可作为兴奋 CB 的一种物质,引起平均动脉压降低,心率减慢,呼吸加强和肾交感神经放电活动增加。  相似文献   
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