Survival of Nucella lapillus in a tributyltin-polluted area in west Brittany: a further example of a male genital defect (Dumpton syndrome) favouring survival

A male genital defect was reported in a Nucella lapillus (L.) population at Dumpton Gap (England). This defect was termed Dumpton syndrome (DS) and appears to be a genetic feature. Its main characteristic is the absence of penis (aphally) in males and in females. In 1992, such a phenomenon was discovered in populations in the vicinity of Brest (Brittany, France). DS-affected females exhibit fewer tributyltin-induced imposex characteristics than expected in normal individuals. The percentage of female sterilization is thus lower, favouring population survival. In consequence, the DS is considered to be a pollution-resistance feature. Comparison with the Dumpton population revealed similarities and differences in the DS characteristics. It is thus hypothesized that the DS observed at the two locations is due to two different biological mechanisms. Indeed, aphallic males with a split prostate were observed but no underdevelopment of their vas deferens and testis was noted in the present study. In this gonochoristic gastropod species, the most DS-affected males in Brest possess an ovotestis and it is thus hypothesized that feminity is remnant in N. lapillus. Incidence of abnormality is ten times higher in females than in males. This suggested that a sex-difference operates in the Brest phenomenon.     

不同生产阶段产生的压电陶瓷废品对氯化丁基橡胶阻尼减振性能的影响

将压电陶瓷生产过程中不同生产阶段产生的废品应用于氯化丁基橡胶阻尼减振材料,并比较了它们对阻尼减振性能的影响.     

周庄旅游者的结构特征及利益追求

旅游客源市场由不同结构特征的旅游者组成,其利益追求各不相同,对此加以分析,可以制定正确的营销策略,提供科学依据.以周庄为案例,采用随机抽样问卷调查法,分别对周庄旅游者的性别结构、年龄结构、文化结构、家庭收入水平结构和职业结构进行了分析.结果显示,周庄旅游者以男性游客为主体,25～44岁的中青年游客占大多数;文化程度以大专及以上层次为主,职业构成比较分散,企事业管理人员居多;家庭月收入水平高于全国平均水平.对旅游者的利益追求进行了初步的探讨,并结合游客结构特征和利益追求的分析结果,提出了周庄未来旅游产品的营销策略.     

Accuracy improvement of various short-term load forecasting models by a novel and unified statistical data-filtering method

ABSTRACT

Time-series and machine-learning methods are being strongly exploited to improve the accuracy of short-term load forecasting (STLF) results. In developing countries, power consumption behaviors could be suddenly changed by different customers, e.g. industrial customers, residential customers, so the load-demand dataset is often unstable. Therefore, reliability assessment of the load-demand dataset is obviously necessary for STLF models. Hence, this paper proposes a novel and unified statistical data-filtering method with the best confidence interval to eliminate unexpected noises/outliers of the input dataset before performing various short-term load forecasting models. This proposed novel data-filtering method, so-called the data pre-processing method, is also compared to other existing data-filtering methods (e.g. Kalman filter, Density-Based Spatial Clustering of Applications with Noise, Wavelet transform, and Singular Spectrum Analysis). By using an SCADA system?-based database of a typical 22kV distribution network in Vietnam, NYISO database, and PJM-RTO database, case studies of short-term load forecasting have been conducted with a conventional ARIMA model, an ANN forecasting model, an LSTM-RNN model, an LSTM-CNN combined model, a deep auto-encoder (DAE) network, a Wavenet-based model, a Wavenet and LSTM hybrid model, and a Wavelet Neural Network (WNN) model, which are to validate the novel and unified statistical data-filtering method proposed. The achieved numerical results demonstrate which the accuracy of the aforementioned STLF models can be significantly improved due to the proposed statistical data-filtering method with the best confidence interval of the input load dataset. The proposed statistical data-filtering method can considerably outperform the existing data-filtering methods.     

Application of Dispersion Modelling for Analysis of Particle Pollution Sources in a Street Canyon

The dominating source of particles in urban air is road traffic. In terms of number concentration, its main contribution is within the range of ultrafine particles (Dp < 100 nm). The dispersion conditions, i.e. transport and dilution, of the submicrometer particles are expected to be like for gases and therefore the particle concentrations in a street canyon can be calculated using gaseous pollutants dispersion models. Such processes, like coagulation or condensation, are less important due to the short residence time within the street canyon environment.Two extensive measuring campaigns were conducted in the street Jagtvej in Copenhagen, Denmark. The particle size distributions were measured by a Differential Mobility Analyser (DMA) coupled to a particle counter, providing high time resolution data (1/2 hourly) on a continuous basis. Measurements of NO_x, CO and meteorological parameters were also available. The measured particle number concentrations, especially below 100 nm, reveal very similar dependence on the meteorological conditions as the NO_x concentrations. This underpins the conclusion that dilution properties are similar for particles and NO_x. For particle sizes over 100 nm, somewhat different behaviour is observed. This points toward existence of additional particle sources, not related to traffic emissions within the street canyon. A significant contribution is believed here to be attributed to long-range transport. The total particle emission from traffic, including daily variation and size distribution, has been calculated using the OSPM dispersion model. Results are in accordance with a previous analysis based on statistical modelling.     

Influence of interspecific competition on the recruitment behavior and liquid food transport in the tramp ant species Pheidole megacephala

This study was conducted on the reactions of Pheidole megacephala scouts when finding liquid food sources situated on territories marked by competing dominant ant species or on unmarked, control areas to see if the number of recruited nestmates is affected and if soldiers behave in ways adapted to the situation. We show that scouts recruit more nestmates, particularly soldiers, on marked rather than on unmarked areas. This recruitment allows P. megacephala to organize the defence and rapid depletion of these food sources prior to any contact with competitors. Soldiers can carry liquid foods both (1) in their crops like other Myrmicinae and (2), in a new finding concerning myrmicine ants, under their heads and thoraxes like certain poneromorph genera because the droplets adhere through surface tension strengths. Later, the liquids stored in the crop are distributed to nestmates through regurgitations during trophallaxis and the external droplets are distributed through social buckets, or the mode of liquid food transfer common in poneromorphs. Their flexibility to use or not use the latter technique, based on the situation, corroborates other reports that Pheidole soldiers have a relatively large behavioral repertoire.     

Minute theropod eggs and embryo from the Lower Cretaceous of Thailand and the dinosaur-bird transition

We report on very small fossil eggs from the Lower Cretaceous of Thailand, one of them containing a theropod embryo, which display a remarkable mosaic of characters. While the surficial ornamentation is typical of non-avian saurischian dinosaurs, the three-layered prismatic structure of the eggshell is currently known only in extant and fossil eggs associated with birds. These eggs, about the size of a goldfinch's, mirror at the reproductive level the retention of small body size that was paramount in the transition from non-avian theropods to birds. The egg-layer may have been a small feathered theropod similar to those recently found in China.     

Environmental analysis of mercury in China

1　Ｄｅｔｅｒｍｉｎａｔｉｏｎｏｆｔｏｔａｌｍｅｒｃｕｒｙａｎｄｓｐｅｃｉａｔｉｏｎｏｆｍｅｒｃｕｒｙｃｏｍｐｏｕｎｄｓｉｎａｔｍｏｓｐｈｅｒｅ1.1　ＤｅｔｅｒｍｉｎａｔｉｏｎｏｆｔｏｔａｌｍｅｒｃｕｒｙＡｓａｍｐｌｉｎｇｔｒａｉｎｃｏｎｓｉｓｔｉｎｇｏｆａｆｉｌｔｅｒｔｏｒｅｔａｉｎ ｐａｒｔｉｃｕｌａｔｅｐｈａｓｅｍｅｒｃｕｒｙｆｏｌｌｏｗｅｄｂｙａｎａｂｓｏｒｂｅｎｔｔｒａｐｗｈｉｃｈｒｅｔａｉｎｓｔｏｔａｌｇａｓｅｏｕｓｍｅｒｃｕｒｙｉｓｕｓｅｄｆｏｒｄｅｔｅｒｍｉｎａｔｉｏｎｏｆｔｏｔａ…     

不同生产阶段产生的压电陶瓷废品对氯化丁基橡胶阻尼减振性能的影响

将压电陶瓷生产过程中不同生产阶段产生的废品应用于氯化丁基橡胶阻尼减振材料，并比较了它们对阻尼减振性能的影响。