Offspring of aged mothers of rotifer Brachionus calyciflorus shows lower sexual propensity than their elder siblings under crowded conditions

Maternal effects are one of the most interesting topics in evolutionary ecology as they can affect the rate of evolution and population dynamics by phenotypic manipulation of offspring related to fitness.At present,studies examining the interaction between maternal environment effects and maternal age(birth order)effects are scarce.We designed an experiment to reveal whether environmentally induced maternal manipulation works equally on offspring across birth orders in rotifer Brachionus calyciflorus.In the experiment,newborn amictic mothers(FO)were cultured parallelly in low(LD)and high(HD)population density.Offspring(F_1)of young(YF_0)and old(OF_0)mothers in both LD and HD groups were cultured under a crowded condition and the mixis ratios of both F_1 and F_2 were examined.Results show that F_1 from HD-YF_0 had a significantly higher mixis ratio and those amictic ones produced daughters(F_2)with higher mixis ratio in response to crowding than those from HD-OF_0.In contrast,no such differences among F_1 siblings were found in the LD-F_0 group.Therefore,the effect of maternal age on the sexual propensity of the offspring can be affected independently by the maternal population density.     

自然资源管理改革基本逻辑下海洋自然资源 年度利用计划的思考

重构自然资源管理体系的重点并不在于直接干预和调整资源配置的结果,而在于优化重塑自然资源配置制度和手段。自然资源管理改革在机构方面基本实现了"两统一",并在海域管理方面取消了过去的围填海年度计划。文章以此为背景,梳理了自然资源管理制度重构的基本逻辑,以围填海为例解析了自然资源管理模式调整思路。基于以上提出海洋自然资源利用年度计划的初步构想,包括将海洋自然资源年度利用计划作为国土空间用途管制中的基础性制度。并提出政策建议:坚持陆海统筹,加强计划管理对海洋资源开发、保护和修复的约束与引导;探索"总量不变、盘活存量"的海洋空间资源供给思路;完善围填海"总量控制、中央统筹"的管理流程;聚焦解决围填海历史遗留问题;加强自然资源法治建设。     

高维遥感图像的快速分类算法

为了实现对高维遥感图像的快速准确分类,提出了一种基于k均值二叉树支持向量机(SVM)的分类方法。该方法通过对选取的训练样本进行k均值聚类,生成支持向量机分类二叉树,作为确定最佳分类顺序的依据,以降低分类过程中的误差累积并提高整体分类精度,而且可缓解由样本数量不均衡导致的分类误差。该方法可在不进行降维处理的情况下,对高维遥感图像进行快速准确分类。测试结果表明,其分类速度和分类精度都优于传统的支持向量机分类结果。     

基于大数据架构的国家海洋创新指标及其预测方法研究

基于国家创新体系理论和大数据思想,探讨国家海洋创新体系定义和范围;根据国家海洋创新体系的具体内容,选取对外海洋技术依存度、海洋仪器设备国有化率、海洋关键技术自主化率、海洋科技进步贡献率、海洋科技成果转化率等作为国家海洋创新预测指标;在Bigtable+MapReduce框架内讨论适用于海洋创新指标的预测方法,探索国家海洋创新指标预测技术思路,为建立支撑海洋创新战略制定的预测体系做了有益尝试。     

计算机辅助绘制流域等流时线

采用地理信息系统方法，对流域的地形地貌特征进行分析，模拟水质点在流域上的运动轨迹，并根据水质点汇流时间与汇流路径，坡度，坡长的关系，建立了流域汇流等流时线模型，经实例验证，效果较好。     

Tide-induced Lagrangian residual velocity and dynamic analysis based on field observations in the inner Xiangshan Bay,China

In the Xiangshan Bay at the east coast of China, coastal marine pollution is conspicuous and severe in recent years. As transport of the pollutants is closely related to the coastal circulation, there is a great practical significance to investigate the circulation in this area. In this work, the surface pattern and vertical profiles of Lagrangian residual velocity (LRV) were studied based on field observation data from the inner Xiangshan Bay. By tracking GPS-GPRS drifters’ trajectories, the surface LRV pattern is going out in the central deep trough and flowing inwards near the shoreside. Combined with data from two mooring stations, vertical profiles of LRV is flowing out at surface and flowing in at the bottom, consistent with the gravitational circulation induced by baroclinic effects at the estuary. However, according to the diagnostic analysis, the main mechanism driving the residual current is barotropic rather than baroclinic. The LRV equation is controlled by the tidally-averaged barotropic pressure gradient force, tidal body force and tidally-averaged turbulent stress, while the tidally-averaged baroclinic pressure gradient force is one order of magnitude less than other forces. Additionally, the tidally mean eddy viscosity coefficient which is used in the expression of tidally-averaged turbulent stress might be not adequate and requires further studies.     

1958—2019年云南省拐卖未成年人犯罪的时空格局及影响因素

拐卖犯罪的时间跨度长、社会危害性高,会对受害者造成一生的记忆创伤。未成年人作为弱势群体,极易受到拐卖犯罪的侵害。早前拐卖的相关研究主要集中在法学和社会学领域,基于地理学视角的研究起步较晚,且缺少针对犯罪高发区云南省的研究。为此,文章基于公益平台“宝贝回家”网站的数据资料,运用数理统计、空间分析等方法,从未成年受害群体视角探究云南省拐卖犯罪的时空格局及影响因素。研究发现：1）来自乡村的被拐未成年人占总体的77%,从乡村拐入乡村的拐卖数量最多;同时,被拐未成年人整体趋于低龄化,呈现较强的低龄男童偏好以及大龄女童偏好。2）1958—2019年云南省拐卖未成年人数量在时间上呈现“倒V型”波动特征,高发期为1994—2005年,其时间演变受特殊历史事件、国家政策和打拐活动等的影响。3）空间上,云南省东部犯罪总量较高,扩散速率较快,其中曲靖、昆明、昭通为热点区域;县域尺度上,官渡区、昭阳区、盘龙区、西山区、五华区、镇雄县、宣威市的被拐未成年人数量占总数的49.5%;同时,过半案件发生在居住场所附近,封闭式公共场所附近案件发生量最少。4）影响因素上,自然因子对拐卖犯罪的影响力度最小,人口因子对犯罪快速增长期影响显著,社会和经济因子对犯罪高发期和低发期的作用显著。     

Land surface temperature shaped by urban fractions in megacity region

The influence of spatial scales on surface fluxes is an interesting but not fully investigated question. This paper presents an analysis on the influence of spatial scales on surface fluxes in the north Tibetan Plateau based on eddy covariance (EC) and large aperture scintillometer (LAS) data at site Nagqu/BJ, combined with the land surface temperature (LST) and normalized difference vegetation index (NDVI) of moderate-resolution imaging spectroradiometer (MODIS). The analysis shows that sensible heat fluxes calculated with LAS data (H_LAS) agree reasonably well with sensible heat fluxes calculated with EC data (H_EC) in the rain and dry seasons. The difference in their footprints due to the wind direction is an important reason for the differences in H_EC and H_LAS. The H_LAS are statistically more consistent with H_EC when their footprints overlap than when their footprints do not. A detailed analysis on H_EC and H_LAS changes with net radiation and wind direction in rain and dry season indicates that the spatial heterogeneity in net radiation created by clouds contributes greatly to the differences in H_EC and H_LAS in short-term variations. A significant relationship between the difference in footprint-weighted averages of LST and difference in H_EC and H_LAS suggests that the spatial heterogeneity in LST at two spatial scales is a reason for the differences in H_EC and H_LAS and that LST has a positive correlation with the differences in H_EC and H_LAS. A significant relationship between the footprint-weighted averages of NDVI and the ratio of sensible heat fluxes at two spatial scales to net radiation (H/Rn) in the rain season supports the analysis that the spatial heterogeneity in canopy at two spatial scales is another reason for differences in H_EC and H_LAS and that canopy has a negative correlation with (H/Rn). An analysis on the influence of the difference in aerodynamic roughness lengths at two spatial scales on sensible heat fluxes shows that the influence is greater in the dry season and smaller in the rain season because the ratio of z_{0m_LAS} to z_{0m_EC} is big in the dry season and is close to 1.0 in the rain season. This study on spatial scales on surface fluxes in the Tibetan Plateau will be helpful in analyzing and understanding its influence on climate.     

群体大小对微囊藻细胞昼夜垂向迁移的影响

针对群体形态对微囊藻昼夜间上浮下沉规律的影响问题,利用柱状培养装置对室内培养的单细胞、群体细胞以及在太湖采集的群体细胞进行了昼夜间分层观测实验,探讨了细胞形态对微囊藻垂向迁移的影响.实验结果表明:单细胞表现出一定的昼夜迁移规律,但无论是室内培养群体细胞还是太湖采集的群体细胞,都未观察到显著的昼夜上浮下沉的变化规律.另一方面,太湖采集的群体细胞表现出显著的漂浮特点.由此认为,室内培养的细胞与实际湖泊细胞之间存在比重上的差异,群体的大小对于上浮有明显的影响.     

5个湖泊河川沙塘鳢(Odontobutis potamophila)种群线粒体细胞色素b基因的遗传变异分析

通过对5个湖泊的河川沙塘鳢种群的线粒体DNA细胞色素b基因进行PCR扩增、测序,获得1141 bp的序列全长.序列分析显示,cyt b基因序列中A+T含量(55.8%)略高于G+C含量(44.2%),共检测到806个多态位点,115个样本得到87个单倍型,平均单倍型多样性为0.969±0.012,核苷酸多样性为0.20081±0.00742,遗传多样性表现高度多样性.太湖种群与大纵湖种群间的遗传距离最近,为0.137,巢湖种群和大纵湖种群之间遗传距离最远,为0.424.分子方差分析表明,群体间遗传分化系数Fst为0.531,变异来自群体内及群体间.cyt b基因序列构建的UPGMA系统进化树显示,5个种群分化成不同的分支系谱,种群间存在的基因交流较少.