Immunohistochemical localization of the progesterone and oestrogen receptors in the shell gland of sexually immature ostriches (Struthio camelus) with active or inactive ovaries

The immunohistochemical localization of progesterone and oestrogen receptors was studied in the shell gland of the immature ostrich (Struthio camelus) during periods of ovarian activity and inactivity. In birds with active ovaries moderate to strong immunostaining for the progesterone receptor was observed in the surface epithelium and tubular glands. In contrast faint progesterone receptor immunostaining was observed in the surface epithelium of the shell gland in ostriches with inactive ovaries. In addition, bud-like invaginations of the surface epithelium, which signaled tubular gland development, were negative for the progesterone receptor. Oestrogen receptor immunostaining, which was seen only in birds with active ovaries, was weak and restricted to nuclei of the surface epithelium. These results suggest that steroid hormones secreted by the active ovary regulate the differentiation of the shell gland. Furthermore, the influence of these hormones on the shell gland appears to be mediated predominantly through the activation of the progesterone receptor.     

玉米不同生育期遭受螟害对产量损失的影响

1963年在北京防蛾网室的条件下,在盆栽春玉米上分期用人工接种螟卵,試驗螟害对产量损失的影响,得出如下的結果: 玉米产量的损失与玉米螟为害当时玉米的生育时期有密切的关系。在螟虫数量相同或接近的情况下,心叶期(心叶中期、心叶末期)被害较穗期(灌浆期)影响产量显著为大;心叶末期孵化的螟虫,其为害所造成的損失又显著较心叶中期为大。心叶期被害的处理,产量較对照区显著減低,但穗期被害的处理,每株平均虫数为3.5—15.1时,产量仍与对照差异不显著。同一接种时期,处理間平均虫数的差异大部分是显著的,但产量間的差异則不显著。玉米受害时期对产量的影响远較同一时期不同虫量的影响为明显。虫数与心叶中期和穗期接种的两个处理的产量有显著的負相关,相关系数分別为-0.89和-0.88;虽然产量随着虫数的增加而递減的趋势是明显的,但每株虫数在1—12头的范围內,产量间差异不一定显著。虫数与心叶末期接种的处理的产量,相关不显著,这可能是由于供試株数太少的原因。应用迴归方程式計算时,每增加一虫产量的損失,心叶中期为3.17％,穗期为1.84％。接种后被害玉米发育受到影响,心叶期遭受螟害植株高度減低17％。作者等指出心叶末期孵化为害的螟虫影响玉米产量特别严重的原因,可能是由于玉米抽雄时,这批幼虫尚未成熟,大量轉移蛀入茎稈或为害正在成长中的雌穗,妨碍营养物的輸送和雌穗的正常受粉所致。本文試驗所得的結果,初步指出当前用颗粒剂防治玉米螟,提倡在心叶末期施药的措施,不仅从減少虫数上看是适当的,从保証产量的角度来看也是有利的。     

颗粒剂防治玉米螟的研究

1960—61连续二年在河北衡水施用颗粒剂防治玉米螟:春、夏玉米心叶末期用5% DDT 颗粒剂,不仅前期的螟虫减少了80—90%左右,穗期的螟害也适当地被控制。1次施药能减少整个春玉米生育期的虫数65—77.4%,夏玉米60—71.9%。防治效果似与玉米后期虫口密度有关。心叶期防治以在心叶末期为最理想,提早施药不能获得最高效果。心叶期防治2次与防治1次的效果没有差异。心叶末期与穗期各防治1次,收获时检查,防治效果春玉米上可达85.8—88.6%,夏玉米90.6—91%。因此,在螟害较轻的年分,防治1次即能解决大部分的螟害问题,大发生年分,可以在穗期再防治1次。试验证明不同载体、不同加工方法配制的颗粒剂、不同用量和不同施用方法的防治效果差异都不显著。虽然含5% DDT 或0.5—1f6的颗粒剂的残效能维持1个月以上,但由于田间植株上残存的颗粒剂损失很快,1个月后的残存量仅为12—15%,因此1次防治的效果受到限制。由于防治效果与施药时螟卵发生的情况关系不大,而心叶未期是防治最适时期,因此作者建议可以玉米生育阶段作为施药时期的标准。     

Ultrastructural features of atretic follicles in the sexually immature ostrich (Struthio camelus)

The aim of this study was to describe the ultrastructural features of atresia in follicles of the immature ostrich (12–14 months old); a ratite that displays seasonal, precocious ovarian activity. The early stage of atresia in primordial, pre-vitellogenic and vitellogenic follicles was characterized by the accumulation of lipid droplets in the granulosa cells. Granulosa cells with condensed cytoplasm and nuclei were a prominent feature during the intermediate phase of atresia. The degenerating follicles were then infiltrated by stroma during the terminal stages of atresia. The results of this study provide further information on the morphology of atretic ovarian follicles in the immature ostrich.     

In Vitro Suppression of Growth of Murine WEHI-3 Leukemia Cells and in Vivo Promotion of Phagocytosis in a Leukemia Mice Model by Indole-3-carbinol

Indole-3-carbinol (I3C), a potential anticancer substance, can be found in cruciferous (cabbage family) vegetables, mainly cauliflower and Chinese cabbage. However, the bioactivity of I3C on the apoptotic effects of murine leukemia WEHI-3 cells and promotion of immune responses in leukemia mice model are unclear. In this study, we investigated the effect of I3C on cell-cycle arrest and apoptosis in vitro and immunomodulation in vivo. I3C decreased the viable WEHI-3 cells and caused morphological changes in a concentration- and time-dependent manner. I3C also led to G0/G1 phase arrest, decreased the levels of cyclin A, cyclin D, and CDK2, and increased the level of p21(WAF1/CIP1). Flow cytometric analyses further proved that I3C promoted ROS and intracellular Ca(2+) production and decreased the levels of ΔΨ(m) in WEHI-3 cells. Cells after exposure to I3C for 24 h showed DNA fragmentation and chromatin condensation. Comet assay also indicated that I3C induced DNA damage in examined cells. I3C increased the levels of cytochrome c, FADD, GADD153, GRP78, and caspase-12 as well as induced activities of caspase-3, -8, and -9. Moreover, I3C attenuated NF-κB DNA binding activity in I3C-treated WEHI-3 cells as shown by EMSA and Western blotting analyses. In the in vivo study, we examined the effects of I3C on WEHI-3 leukemia mice. Results showed that I3C increased the level of T cells and decreased the level of macrophages. I3C also reduced the weights of liver and spleen, and it promoted phagocytosis by macrophages as compared to the nontreated leukemia mice group. On the basis of our results, I3C affects murine leukemia WEHI-3 cells both in vitro and in vivo.     

Observation of quantum criticality with ultracold atoms in optical lattices

Quantum criticality emerges when a many-body system is in the proximity of a continuous phase transition that is driven by quantum fluctuations. In the quantum critical regime, exotic, yet universal properties are anticipated; ultracold atoms provide a clean system to test these predictions. We report the observation of quantum criticality with two-dimensional Bose gases in optical lattices. On the basis of in situ density measurements, we observe scaling behavior of the equation of state at low temperatures, locate the quantum critical point, and constrain the critical exponents. We observe a finite critical entropy per particle that carries a weak dependence on the atomic interaction strength. Our experiment provides a prototypical method to study quantum criticality with ultracold atoms.     

Resistance to Pseudomonas solanacearum in the potato: II. Aspects of host-pathogen-environment interaction

Summary White clover genotypes were selected for high and low values of leaf size, taproot diamater, number of taproots, proportion of total root and taproot dry weight. Crosses within selected groups of genotypes resulted in 14 seed lines, which were compared with parent genotypes in field tiles. Selections for taproot diameter and proportion taproot were more successful than those for taproot number and proportion root.Narrow sense heritability of characters calculated by regression of progeny on mid-parent values were well correlated with broad sense heritabilities derived from replicated clonal comparisons (r=0.73^*), indicating that the genetic variation is controlled predominantly by additive gene effects.     

Phytotoxicity of Sunflower Residues against Some Summer Season Crops

The growth of four summer season crops, namely Cyamopsis tetragonoloba , Sorghum vulgare , Pennisetum americanum and Zea mays , in fields with or without residues of the preceding sunflower crop was poor. Crop density, weight of seed or grain and total yield were significantly lower in sunflower fields than in the control fields (i.e. those without previous sunflower crops). Growth in terms of plant height and biomass was drastically reduced after 60 days. The effect was more pronounced in the fields where sunflower residues were allowed to decompose than in those where residues were completely removed. The soil collected from sunflower fields (both with and without residues) was found to be rich in phenolics, which in a laboratory bioassay were found to be phytotoxic. The reduced growth and yield of crops can be attributed to the release of phytotoxic phenolics from decomposing sunflower residues.