青海不同产区大黄的X-射线衍射图谱研究（摘要）

[目的]为区分不同产地大黄药材的质量及鉴别提供依据。[方法]将供试材料青海玉树掌叶大黄（样品1）、青海海南唐古特大黄（样品2）与青海果洛唐古特大黄（样品3）分别粉碎成粉末,过100目筛,即可供X射线衍射试验用。设定管压30 kV,管流20 mA,2θ扫描范围3°～90°,扫描速度0.06°/s,每种样时间0.5 s,获得3种不同产区大黄的X-射线衍射图谱。试验数据以晶面间距d与特征峰相对强度L/Io表示,记为d/（I/Io）。将试验数据导入中药指纹图谱相似度计算软件,经选峰,设定匹配模板,将谱峰自动匹配,然后设定标准模板,进行谱峰差异性评价和整体相似性评价。[结果]样品1中所含的化学成分与样品2相同,但峰的强度（I/Io）不同,表明相同成分在两种样品中的含量不相等。同样把样品3的图谱与其他两个样品进行比较,也会得到相同的衍射峰值。表明不同产区的大黄中各化学成分的含量有差异,但其衍射图谱及衍射峰值具有一定的指纹特征。[结论]X-射线衍射法是鉴别不同产区的大黄及其他中药材的一种快捷有效的方法。     

New Pseudococcidae species on Cupressus macrocarpa in Tunisia: first report of Planococcus vovae

In May 2017 and 2018, Planococcus vovae (Nasonov) (Hemiptera: Pseudococcidae) was collected in Hammam Sousse (Tunisia) on the ornamental plant Cupressus macrocarpa (Cupressaceae). The infestation was observed on needles which showed symptoms of desiccation and chlorosis. This is the first record of P. vovae in Tunisia and in North Africa.     

The diving behaviour of little penguins in Western Australia predisposes them to risk of injury by watercraft

1. The most western little penguin colony globally, and the most northern in Western Australia (WA) is found on Penguin Island, WA. The penguins use coastal bays that are also used extensively by recreational watercraft. These penguins have been found to either dive predominantly to shallow depths of 1–5 m or to depths >8 m. It is thus hypothesized that (a) both the shallow and deeper diving penguins can potentially be disturbed or injured by these watercraft but that the risk will differ between the two diving strategies, and (b) that risk of injury for both is greater during the summer and autumn, when people are more likely to use watercraft.
2. This was tested by attaching data loggers to little penguins during chick rearing and by investigating necropsy records. Diving activity was studied for the very shallow and relatively deeper diving penguins separately, and we considered the penguins were vulnerable to interactions with watercraft when they were within the top 2 m of the water column or at the surface.
3. Shallow‐diving penguins executed >1,200 dives per day, 64% of dives occurred within the top 2 m, and they were vulnerable for approximately two‐thirds of their time at sea. The deeper diving penguins executed fewer dives. Almost half of dives were to ≥10 m, yet they were vulnerable for almost one‐third of their time at sea. Their post‐dive recovery was also longer. Thus, the risk of interaction from watercraft differs depending on the diving behaviour.
4. This study highlights the potential impact to little penguins throughout Australia and New Zealand.

     

Combined application of nitrogen and phosphorus to enhance nitrogen use efficiency and close the wheat yield gap on varying soils in semi‐arid conditions

A primary driver of the wheat yield gap in Australia and globally is the supply of nitrogen (N) and options to increase N use efficiency (NUE) are fundamental to closure of the yield gap. Co‐application of N with phosphorus (P) is suggested as an avenue to increase fertiliser NUE, and inputs of N and P fertiliser are key variable costs in low rainfall cereal crops. Within field variability in the response to nutrients due to soil and season offers a further opportunity to refine inputs for increased efficiency. The response of wheat to N fertiliser input (0, 10, 20, 40 and 80 kg N ha^‐1) under four levels of P fertiliser (0, 5, 10 and 20 kg P ha^?1) was measured on three key low rainfall cropping soils (dune, mid‐slope and swale) across a dune‐swale system in a low rainfall semi‐arid environment in South Australia, for three successive cropping seasons. Wheat on sandy soils produced significant and linear yield and protein responses across all three seasons, while wheat on a clay loam only produced a yield response in a high rainfall season. Responses to P fertiliser were measured on the sandy soils but more variable in nature and a consistent effect of increased P nutrition leading to increased NUE was not measured.     

Comparison of traditional and environmental DNA survey methods for detecting rare and abundant freshwater fish

1. Detecting rare species is often a necessity for conservation and management, yet challenging for many field survey methods. Environmental DNA (eDNA) is a highly promising solution that has been shown to outperform many established survey methods.
2. Macquarie perch (Macquaria australasica) is an endangered native species that has declined significantly in range and abundance. Detection of M. australasica was compared with an abundant alien fish species (Oncorhynchus mykiss) using eDNA and three conventional survey methods: gill nets, electrofishing and fyke nets.
3. eDNA occupancy estimates for both fish species were compared using four different models to investigate what effect these differences have on false positives and false negatives for the rare and common fish species. These models used unadjusted eDNA detections in water samples, eDNA detections that have been screened using a limit of detection method to remove potential false positives, eDNA data supplemented with a second survey method, or eDNA data augmented with sequencing of positive polymerase chain reaction replicates.
4. eDNA surveying as a single detection method was found to be more efficient and sensitive compared with each capture method separately and combined. Occupancy estimates for the common and rare species did not vary significantly between the four site occupancy-detection models, suggesting that supplementary data may not have as much effect on occupancy estimates compared with other approaches such as temporal or spatial sampling.
5. We conclude that eDNA outperforms the three established survey methods for both a rare and common freshwater fish species. Although there was no significant effect of augmenting eDNA survey methods with other survey data, additional data may improve confidence in detection, and provide confirmatory evidence for unexpected or new detections of a species.

     

Food consumption and selectivity by larval yellowtail kingfish Seriola lalandi cultured at different live feed densities

Live food supply is a key factor contributing to the success of larval fish rearing. However, live food densities vary greatly between fish species and management protocols across fish hatcheries. The growth, survival, food selection and consumption of yellowtail kingfish larvae were examined at different regimes of live food supply in an attempt to identify a suitable live food feeding protocol for larval rearing in marine fish. This study was divided into two feeding phases: rotifer phase from 3 to 14 DPH (phase I) and Artemia nauplii phase from 15 to 22 DPH (phase II). In phase I, four rotifer densities (1, 10, 20 and 40 mL⁻¹) were used. In phase II, Artemia started at 0.8 nauplii mL⁻¹ on 15 DPH, and then the density of Artemia was daily incremented by 50%, 70%, 90% and 110%, respectively, in four treatments from 15 to 22 DPH. In phase I, rotifer density significantly affected larval growth, but not survival. By 7 DPH, the number of rotifers consumed by fish larvae reached 170–260 individuals, but did not significantly differ between rotifer densities. During cofeeding, fish larvae selected against Artemia nauplii by 10 DPH, but by 14 DPH Artemia nauplii became the preferred prey item by fish larvae exposed to the 10, 20 and 40 rotifers mL⁻¹. In phase II, both fish growth and survival were affected by Artemia densities. Fish daily consumption on Artemia by 20 DPH reached 500–600 individuals but did not significantly differ between prey densities. The result suggests that rotifer densities be offered at 20–40 mL⁻¹ before 6 DPH and 10–20 mL⁻¹ afterwards to support larval fish growth and survival. Likewise, Artemia is recommended at a daily increment of 90–110% of 0.8 mL⁻¹ from 15 to 22 DPH. This study proposes a management protocol to use appropriate type and quantity of live food to feed yellowtail kingfish larvae, which could be applicable to larval culture of other similar marine fish species.     

桉树木材干燥特性与工艺及其皱缩研究现状

本文回顾和分析了桉树木材与干燥有关的材性和干燥特性 ,指出桉木的密度、含水率和干缩率变异性大、渗透性差 ,在干燥过程中易产生皱缩、开裂等干燥缺陷 ,若采用预冻处理和前后期调湿处理可减少木材的皱缩 ;同时建议研究各种桉木不同规格板材的干燥基准和两段式干燥工艺     

转玉米C4光合酶基因水稻株系中的光合C4微循环

用转PEPC、PPDK、NADP-ME、PEPC PPDK等酶基因的水稻株系及原种野生型(WT)为材料, 研究了不同基因型水稻叶片中的C4光合微循环及其功能.用外源OAA或MA饲喂叶切片或离体叶绿体后,光合放氧速率在野生型水稻中增加了50%,在NADP-ME-和PPDK-转基因水稻中增加了50%～54%,在PEPC-和 PEPC PPDK-转基因水稻中增加了100%～150%.证明原种水稻Kitaake叶片中具有一个原初的和有限的C4光合微循环,除PPDK基因、NADP-ME基因外,外源PEPC基因或PEPC PPDK双基因导入原种水稻Kitaake后,可大幅度提高C4光合微循环的运行.水稻中C4光合微循环的增强有降低光呼吸速率(Pr)、增加净光合速率(Pn)的作用,在光能利用上,可增加PSⅡ光化学效率(Fv/Fm)、光化学猝灭(qp)、降低非光化学猝灭(qN)的作用;这些结果为转C4光合酶基因水稻中建立C4微循环系统来提高光合作用效率的可能性提供了依据.     

赤峰市城市森林建设资源潜力分析

文章以2007年赤峰市森林资源二类调查数据为基础,并结合赤峰市相关单位提供的统计数据,以及近年来的林业生态建设实践发展,主要从林业用地、三网绿化、人居环境林建设、坡耕地绿化和工矿废弃地绿化对赤峰市生态用地潜力进行分析,结果表明赤峰市城市森林建设有一定的资源发展潜力。