The reproductive system and gametogenesis in a nematode Distolabrellus veechi

以线虫Distolabrellus veechi的卵巢和精巢为材料,用甲醇固定,DAPI荧光染料对细胞核进行染色,通过Normaski荧光显微镜对其生殖系统结构、性细胞染色体数目、体细胞染色体数目进行了观察。结果显示了该线虫雌虫和雄虫生殖细胞减数分裂Ⅰ前期的细胞核的变化特征;减数分裂Ⅰ前期丝球期雌、雄生殖细胞的二价体数目均为6;卵细胞染色体数目为6,精细胞染色体数目为5或6,其性别决定机制为XX/X0型;体细胞染色体数目为11(雄虫)或12(雌虫)。In this study we analyzed oogenesis and spermatogenesis in the nematode Distolabrellus veechi.The D.veechi germ line can be divided into several regions based upon the state of the DNA in the nuclei visualized by DAPI in situ staining of dissected adult gonadal arms.We identified a mitotic zone,a transition zone between mitosis and meiosis,a pachytene zone and a diakinesis zone.In D.veechi males,the primary spermatocytes initially assemble on the rachis.Upon entering meiosis,the primary spermatocytes develop to the diplotene stage and bud away from the rachis.At diakinesis(which follows the diplotene stage) six spermatocyte bivalents become more apparent due to chromosomal condensation.The spermatocytes then undergo two maturation divisions and produce haploid spermatids,which are stored in the seminal vesicle.Five or six chromosomes can be seen in the spermatids.The male's somatic gonad consists of three tissues:two distal tip cells,the seminal vesicle and the vas deferens.In D.veechi females,oogonia(early oocytes) are produced from the rachis.The oocytes then undergo a growth phase and arrest at diakinesis;further development is halted until fertilization occurs.At this time,six bivalents can be seen.After penetration of the oocyte by a sperm,the oocyte advances to the metaphase stage and passes into the uterus.After two maturation divisions have been completed,two polar bodies are formed.Shortly afterwards,the sperm and egg pronuclei fuse to form the zygote nucleus,and cleavage division begin after some time.The somatic gonad of female D.veechi consists of one distal tip cell,the gonadal sheath,the spermatheca,the oviduct and the uterus.The results of this study also indicate that D.veechi show a 2N condition of 11 chromosomes for males,and 12 for females.国家自然科学基金资助项目(No.30670237)~

Social Attitude of Urban and Ｒural Ｒesidents—Analysis of a Sampling Survey Data

利用2014年中国科学院心理研究所第三期社会调查数据,解析城乡居民的社会心态。城乡居民对生活状况基本满意,对国家经济发展形式比较乐观。生活压力相对较大的方面为&quot;养老问题&quot;和&quot;看病就医&quot;,对中央政府的满意度高于地方政府,对地方民主参与的评价不高,只有极少数居民认为本地县(市)政府推行一项政策时,经常征求老百姓的意见。普遍认为腐败、物价上涨、贫富差距大是比较严重的社会问题。面对不公平事件,尽管大部分居民倾向于以理性的方式解决,但也有约1/5的居民选择&quot;联合亲友对抗&quot;、&quot;罢工罢课&quot;或&quot;集体示威&quot;作为应对不公平事件的首选应对方式。定期调查民众的社会心态,有助于发现社会问题,促进政府执政能力的提升。</p

2005～2014年CERN野外台站气象观测场土壤含水量数据集

土壤水分是影响陆地–大气边界层能量和物质传输的重要因子。土壤水分含量是中国生态系统研究网络(CERN)陆地生态系统水环境长期定位观测的重要指标。截至2014年,CERN全国范围内包括农田、森林、草地、荒漠与湿地等生态类型的34个陆地生态系统台站,依据陆地水环境观测规范、质量保证与质量控制规范,设立观测样地,并开展土壤含水量的长期定位观测与数据汇交及质控工作。CERN水分分中心选取了这34个台站2005～2014年气象观测场的土壤含水量长期监测数据,通过进一步统一规范数据格式,形成了全国范围内较长时间序列的公开共享数据集,为土壤含水量时空动态的遥感反演、模型估算验证提供地面实测数据支撑

JUNO Sensitivity on Proton Decay p→νˉK+p\to \bar\nu K^+ Searches

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in $p\to \bar\nu K^+$ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar\nu K^+$ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is $9.6 \times 10^{33}$ years, competitive with the current best limits on the proton lifetime in this channel

JUNO sensitivity on proton decay p → ν K + searches*

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this study, the potential of searching for proton decay in the $p\to \bar{\nu} K^+$ mode with JUNO is investigated. The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits suppression of the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar{\nu} K^+$ is 36.9% ± 4.9% with a background level of $0.2\pm 0.05({\rm syst})\pm$$0.2({\rm stat})$ events after 10 years of data collection. The estimated sensitivity based on 200 kton-years of exposure is $9.6 \times 10^{33}$ years, which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies