Reproduction in three species of rainbowfish (Melanotaeniidae) from rainforest streams in northern Queensland, Australia

Abstract – The reproductive biology of three species of rainbowfish (Melanotaeniidae) in northeastern Australian rainforest streams was investigated. Two species, Melanotaenia eachamensis and Cairnsichthys rhombosomoides are endemic to the area, whereas the third, M. splendida splendida, is more widespread. The species were all highly fecund, producing many hundreds of eggs between 1.10 and 1.24 mm in diameter. Melanotaenia eachamensis was the most fecund, produced the largest eggs of the three species, and consequently exhibited the greatest maternal investment (as measured by gonadosomatic index). The majority of reproductive effort occurred during the dry season, although reproductively active fish were present year-round for each of the species, but particularly so for M. s. splendida and C. rhombosomoides. No evidence for a role by temperature or photoperiod as environmental cues for reproduction was found, and it was suggested that gonad development was strongly tied to somatic growth. The concentration of reproduction to the dry season ensures that larvae are produced during a period of relatively stable and benign physical conditions. Comparison of temporal changes in gonadosomatic index values suggest that the spawning season of M. eachamensis , which occurs in high-elevation streams, is more restricted and commences about 1 month earlier than either other species. A similar phenology was observed for the M. s. splendida population found at high elevation and highlights the potential for spatial differences in stream productivity to influence life history. ^Note     

基于工作流的ERP系统重构的研究

分析了企业现有ERP系统运营存在的缺陷，提出了适合本企业的基于工作流的ERP系统重构的开发方案。     

基于复杂种植结构多情景分析的灌区多目标多水源优化配置

为改善多水源灌区农业用水供需矛盾,通过合理调整种植结构,优化灌区水资源配置,该研究以河北省邯郸市漳滏河灌区为研究对象,将农业灌溉缺水量最小和农作物经济效益最大作为目标函数,兼顾灌区生态安全约束,构建了基于种植结构优化的多目标多水源优化配置模型,针对作物熟制、作物种类、种植制度以及灌溉方式设置了8种不同的种植结构优化情景,通过自主改进的基于精英策略并协遗传算法（NSGAⅡ-S）对模型求解,获得不同情景下的水资源优化配置方案。结果表明：应用模型进行水资源配置后,各情景配水总量均有所减少,其中水库配水量高于其他水源的配水量,水库水、引黄水和引江水均达到用水总量控制目标,民有分区的各计算单元间的配水量变化明显,总配水量高于滏阳河分区;适当压减主要依靠抽取地下水灌溉的冬小麦的播种面积,变灌溉农业为旱作雨养农业,可以极大地减少地下水用量,增加灌区经济效益;最佳的种植结构优化方案为CS₄（削减冬小麦的种植面积,种植苜蓿,灌溉方式采取管灌或喷灌）,该方案冬小麦播种面积压减17.10%,地下水开采量减少了16.42%,灌区的经济效益增加了26.41%,在保证配水总量最小的同时,具有更高的经济效益。该研究所构建的多目标多水源优化配置模型和作物配水结果可为类似地区的水资源配置提供参考。     

型钢拱架日光温室结构稳定性能及参数分析

型钢拱架日光温室结构的主要受力构件长细比大,暴雪等极端灾害天气下易引发结构失稳灾变。针对此问题,该研究利用弹塑性力学理论和非线性有限单元法,建立型钢拱架日光温室结构精细化有限元模型,开展雪荷载下日光温室稳定性能分析;通过对型钢截面类型（平椭圆形截面、箱形截面和几字形截面）、温室跨度（8、10和12 m）、雪荷载分布形态（分布厚度不均匀和分布区域不对称）等参数下进行日光温室失稳全过程分析,分别确定日光温室稳定承载力,揭示雪荷载分布对日光温室稳定承载力的量化影响;结合日光温室的荷载系数-位移全过程曲线和不同加载时刻点的变形图、应力图、轴力图与弯矩图,从直观现象和内在本质两个层面深入探明日光温室的静力失稳机理。分析结果表明：在保证不发生平面外整体失稳的前提下,当型钢截面面积和翼缘宽度相同时,相较于箱形截面型钢、几字形截面型钢,采用平椭圆形截面型钢拱架的日光温室稳定承载力分别提高了19.2%和44.2%;跨度对日光温室稳定承载力的影响较大,与8 m跨度相比,10、12 m跨度的日光温室的荷载系数分别下降了27.1%和57.9%;相较于均匀分布雪荷载,在非均匀分布雪荷载下日光温室的稳定承载力最大下降63.8%;相较于不设置拉杆和撑杆的情况,单独设置拉杆的日光温室稳定承载力最大可提高9.0%,单独设置撑杆的日光温室稳定承载力最大可提高66.8%。该研究得出的结果和给出的建议可为型钢拱架日光温室结构抗雪设计、稳定性研究和防灾分析提供技术指导和理论参考。     

长江安庆江段存在溯河洄游型和淡水定居型刀鲚实证研究

为了探究长江十年禁渔后安庆江段刀鲚的生境履历,利用X射线电子探针微区分析技术研究安庆江段不同类型长颌刀鲚(Coilia nasus)和短颌刀鲚的耳石Sr和Ca微化学特征。结果显示,根据耳石Sr/Ca值的变化值将安庆江段的短颌刀鲚分为2类,一类是其比值为一直小于3.0的低值,表明其纯淡水的生境履历;另一类是其比值不仅有小于3.0的低值区,还有大于3.0的高值区(小于7.0),表明其不仅有淡水的生境履历,还有高盐度的河口半咸水生境履历。长颌刀鲚的耳石Sr/Ca值均具有小于3.0的低值区和大于3.0 (甚至大于7.0)高值区的显著波动,表现为典型的淡水、河口半咸水及海水的溯河洄游型生境履历,Sr含量面分析图谱也可印证上述结果。本研究表明,长江安庆江段刀鲚群体组成较为复杂,同时存在溯河洄游型、淡水定居型短颌刀鲚和溯河洄游型长颌刀鲚3种生态表型个体。     

Prediction of irrigation return flows through a hierarchical modeling approach

The quantity of water available for irrigation is getting scarce in many countries and it assumes great importance for assured crop production, especially in view of the erratic behavior of the monsoon. Thus, there is a pressing need to improve the water efficiency of irrigation systems. One-way of improving the efficiency of the irrigation system is reusing the return flow from the irrigation system. This task requires quantification of return flow, which still remains as a grey area in irrigation water management. The estimation of return flow from the irrigation system is usually obtained using thumb rules depending upon the site-specific conditions like command area conditions and soil properties. In this paper, a hierarchical modeling technique, namely, regression tree is developed for return flow estimation. Regression tree is built through binary recursive partitioning. The effective rainfall, inflow, consumptive water demand, and percolation loss are taken as predictor variables and return flow is treated as the target variable. The applicability of the hierarchical model is demonstrated through a case study of Periyar-Vaigai Irrigation System in Tamil Nadu, India. The model performance shows a good match between the simulated and the field measured return flow values. Results of statistical analysis indicated that the correlation coefficients are high for both single as well as double crop seasons.     

矾根主要品种的叶色表型性状分析

通过目测进行分类的方式很难准确界定矾根品种叶色。为建立一套更为科学的基于叶色表型的矾根品种分类体系,笔者利用色差仪对72个矾根品种共计432个样品的叶色进行测定,对获得的L、a、b 3个色度值进行聚类分析,将72个矾根品种分为褐色系、深绿色系、黄色系、灰绿色系、浅绿色系5类色系。对矾根品种各色系的L、a、b值进行相关性分析,发现叶片正面的L值与a值、a值与b值呈负相关,L值与b值呈正相关,但相关性不明显;叶片背面的L值与a值、a值与b值呈负相关,L值与b值呈显著正相关。从多重比较的结果中可以看出,矾根品种各色系之间的L、a、b色度值差异显著,尤其是各色系间叶正面的颜色差异较大,在矾根品种选育工作中,叶片正面的颜色将作为主要参考。     

猪繁殖与呼吸综合征病毒实验感染SPF猪外周血单核细胞和肺泡巨噬细胞早期凋亡细胞的观察

采用Ａｎｎｅｘｉｎ Ｖ－ＦＩＴＣ／ＰＩ双染色法,用流式细胞仪检测了猪繁殖与呼吸综合征病毒（ＰＲＲＳＶ）实验感染ＳＰＦ猪不同时期外周血单核细胞和肺泡巨噬细胞感染Ａｎｎｅｘｉｎ Ｖ－ＦＩＴＣ＾＋／ＰＩ＾－细胞群（早期凋亡细胞群）。结果显示,ＰＲＲＳＶ感染猪外周血单核细胞和肺泡巨噬细胞Ａｎｎｅｘｉｎ Ｖ－ＦＩＴＣ＾＋／ＰＩ＾－细胞群的表达率均明显高于正常对照猪,感染后２４ｈ表达率达最高值。     

Genetic diversity,anti‐microbial resistance,plasmid profile and frequency of the Vi antigen in Salmonella Dublin strains isolated in Brazil

Salmonella Dublin is strongly adapted to cattle causing enteritis and/or systemic disease with high rates of mortality. However, it can be sporadically isolated from humans, usually causing serious disease, especially in patients with underlying chronic diseases. The aim of this study was to molecularly type S. Dublin strains isolated from humans and animals in Brazil to verify the diversity of these strains as well as to ascertain possible differences between strains isolated from humans and animals. Moreover, the presence of the capsular antigen Vi and the plasmid profile was characterized in addition to the anti‐microbial resistance against 15 drugs. For this reason, 113 S. Dublin strains isolated between 1983 and 2016 from humans (83) and animals (30) in Brazil were typed by PFGE and MLVA. The presence of the capsular antigen Vi was verified by PCR, and the phenotypic expression of the capsular antigen was determined serologically. Also, a plasmid analysis for each strain was carried out. The strains studied were divided into 35 different PFGE types and 89 MLVA‐types with a similarity of ≥80% and ≥17.5%, respectively. The plasmid sizes found ranged from 2 to >150 kb and none of the strains studied presented the capsular antigen Vi. Resistance or intermediate resistance was found in 23 strains (20.3%) that were resistant to ampicillin, ciprofloxacin, chloramphenicol, imipenem, nalidixic acid, piperacillin, streptomycin and/or tetracycline. The majority of the S. Dublin strains studied and isolated over a 33‐year period may descend from a common subtype that has been contaminating humans and animals in Brazil and able to cause invasive disease even in the absence of the capsular antigen. The higher diversity of resistance phenotypes in human isolates, as compared with animal strains, may be a reflection of the different anti‐microbial treatments used to control S. Dublin infections in humans in Brazil.