Foraging strategies involved in habitat use of shorebirds at the intertidal area of Chongming Dongtan, China

Dense flocks of migratory shorebirds from diverse species often concentrate in the intertidal areas for stopover. Trophic structure, food partition, prey availability and selectivity, predation risk, and abiotic factors are often used to explain the differences in habitat use of coexisting shorebirds. We sampled the macrobenthos and surveyed the distribution of shorebird populations to study the effects of foraging strategies on the habitat use of shorebirds at Chongming Dongtan, an important stopover site for shorebirds on the East Asian–Australasian Flyway. Results show that the relative abundance of epifaunal macrobenthos in salt marshes was much higher than that in the bare flats, whereas the relative abundance of infaunal macrobenthos in salt marshes was much lower than that in bare flats. The relative abundance of two life forms of macrobenthos was similar in the transitional zones between the salt marshes and the bare flats. Shorebirds with different foraging strategies exhibited different habitat uses. Pause-travel shorebirds mainly utilized the salt-marsh fringes, while tactile continuous shorebirds relied heavily on the bare flats. There was no significant difference in habitat use for visual continuous shorebirds. The density of tactile continuous shorebirds was positively correlated with bivalve density, and that of visual continuous shorebirds positively with crustacean density. Meanwhile, the relative abundance of pause-travel foraging shorebirds was positively correlated with the relative abundance of epifaunal, but negatively with infaunal macrobenthos. In contrast, the relative abundance of tactile foraging shorebirds had a positive correlation with infaunal but a negative one with epifaunal life form. Therefore, foraging strategies may play important roles in shorebirds’ habitat use in intertidal areas.     

Mechanism of translesion synthesis past an equine estrogen-DNA adduct by Y-family DNA polymerases

4-Hydroxyequilenin (4-OHEN)-dC is a major, potentially mutagenic DNA adduct induced by equine estrogens used for hormone replacement therapy. To study the miscoding property of 4-OHEN-dC and the involvement of Y-family human DNA polymerases (pols) eta, kappa and iota in that process, we incorporated 4-OHEN-dC into oligodeoxynucleotides and used them as templates in primer extension reactions catalyzed by pol eta, kappa and iota. Pol eta inserted dAMP opposite 4-OHEN-dC, accompanied by lesser amounts of dCMP and dTMP incorporation and base deletion. Pol kappa promoted base deletions as well as direct incorporation of dAMP and dCMP. Pol iota worked in conjunction with pol kappa, but not with pol eta, at a replication fork stalled by the adduct, resulting in increased dTMP incorporation. Our results provide a direct evidence that Y-family DNA pols can switch with one another during synthesis past the lesion. No direct incorporation of dGMP, the correct base, was observed with Y-family enzymes. The miscoding potency of 4-OHEN-dC may be associated with the development of reproductive cancers observed in women receiving hormone replacement therapy.     

我国洛阳与菏泽牡丹主栽园区AM真菌多样性研究

为探明我国特有花卉牡丹 (Paeonia suffruticosa) 根围内的丛枝菌根(AM)真菌资源状况, 作者对河南省洛阳市与山东省菏泽市牡丹主产区土壤中的AM真菌进行了调查。共分离到AM真菌5属35 种, 其中球囊霉属(Glomus)在各采样点相对多度最高, 其次是无梗囊霉属(Acaulospora)。两地土壤中AM真菌种的丰度、孢子密度和物种多样性指数等存在差异: 菏泽赵楼牡丹园AM真菌种的孢子密度最高,而其种的丰度最低; 洛阳矬里牡丹种苗基地的孢子密度最低; 菏泽种苗基地的Shannon-Wiener指数显著高于其他样地。地球囊霉(Glomus geosporum)是洛阳王城公园和菏泽赵楼牡丹园的优势种; 缩球囊霉(Glomus constrictum)为洛阳土桥花木基地、洛阳牡丹园、菏泽牡丹种苗基地和菏泽赵楼牡丹园的优势种。本研究结果表明我国牡丹主栽园区AM真菌具有丰富的多样性。     

基于结构域组合信息预测蛋白质相互作用

基于多个结构域联合作用导致蛋白质间相互作用的假设,提出了一种预测蛋白质间相互作用的新方法。使用支持向量机分析结构域组合对序列的氨基酸理化性质得到其序列特征值,同时采用统计分析的方法获取其频率特征值,最后通过融合上述两种特征估计该结构域组合间发生相互作用的可能性,并以此预测蛋白质间相互作用关系。该方法能够预测所有结构域组合间相互作用关系,且对于蛋白质相互作用关系有着较好的预测效果。     

Response of Douglas-fir and amabilis fir to split-root nutrition with inorganic and organic nitrogen

There is limited understanding of the spatial plasticity of conifer root growth in response to inorganic and organic nitrogen (N). In this study, slow-growing amabilis fir and fast-growing Douglas-fir, and slow- and fast-growing seedlots of the latter species were examined for their ability to proliferate roots preferentially in compartments of sand/peat medium enriched in organic and inorganic forms of N. In one experiment, N was supplied as 7.1 or 0.71 mM ammonium, nitrate and ammonium nitrate, and in a second experiment, N was supplied as ammonium or glycine. The seedlings’ ability to compensate for the starvation of a portion of the root system was assessed by measuring biomass of leaves, stems and roots, and foliar N concentration. Both fast- and slow-growing seedlots of Douglas-fir and slow-growing amabilis fir were able to proliferate roots in compartments of soil enriched with inorganic and organic N. In the first experiment, whole plant and root biomass was greatest when N was provided as ammonium followed by nitrate, and in the second experiment, seedling whole and root biomasses did not differ between ammonium and glycine treatments. All seedlings were able to compensate for the starvation of a portion of the root system, thus total plant biomass did not differ between split-root treatments; however, foliar N contents were lower in the 7.1/0.71 mM inorganic N split-root treatments. Foliar N concentrations were also lower in seedlings supplied with glycine.     

An agent-based model to investigate the roles of attractive and repellent pheromones in ant decision making during foraging

Pharaoh's ants organise their foraging system using three types of trail pheromone. All previous foraging models based on specific ant foraging systems have assumed that only a single attractive pheromone is used. Here we present an agent-based model based on trail choice at a trail bifurcation within the foraging trail network of a Pharaoh's ant colony which includes both attractive (positive) and repellent (negative) trail pheromones. Experiments have previously shown that Pharaoh's ants use both types of pheromone. We investigate how the repellent pheromone affects trail choice and foraging success in our simulated foraging system. We find that both the repellent and attractive pheromones have a role in trail choice, and that the repellent pheromone prevents random fluctuations which could otherwise lead to a positive feedback loop causing the colony to concentrate its foraging on the unrewarding trail. An emergent feature of the model is a high level of variability in the level of repellent pheromone on the unrewarding branch. This is caused by the repellent pheromone exerting negative feedback on its own deposition. We also investigate the dynamic situation where the location of the food is changed after foraging trails are established. We find that the repellent pheromone has a key role in enabling the colony to refocus the foraging effort to the new location. Our results show that having a repellent pheromone is adaptive, as it increases the robustness and flexibility of the colony's overall foraging response.     

条形柄锈菌34号生理小种的分子标记

条形柄锈菌Puccinia striiformis f. sp. tritici 34号生理小种(CYR34)是目前我国毒性谱最宽、毒性最强的生理小种,对小麦生产和抗病品种选育造成了极大的影响。本研究采用RAPD-SCAR分子标记技术,从300条RAPD随机引物中筛选到CYR34的特异引物,通过特异性片段回收、克隆和测序(GenBank登录号为OL907303),依据序列设计出了S2008F34/S2008R34特异性引物,能够从CYR34及接种CYR34的小麦发病叶片总DNA中都扩增出417 bp的目标片段。采用该特异性引物检测2021年陕西渭南、咸阳和宝鸡地区小麦条锈菌CYR34的流行频率分别为8.6%、6.0%和10.8%。该项研究为小麦条锈菌CYR34号生理小种的快速检测提供了技术支撑。     

补中益气汤联合低频脉冲电刺激促进产后盆底功能障碍的效果及血清松弛素、CTGF和MMP-1水平的影响

摘要 目的：探讨补中益气汤联合低频脉冲电刺激促进产后盆底功能障碍的效果及血清松弛素（RLX）、结缔组织生长因子（CTGF）和基质金属蛋白酶-1（MMP-1）水平的影响。方法：选取我院2022年4月到2023年4月收治的150例产后盆底功能障碍患者作为研究对象,分为观察组与对照组,各组均75例。对照组患者采取低频脉冲电刺激治疗,观察组患者采取补中益气汤联合低频脉冲电刺激治疗,对比两组患者的临床疗效,治疗前后盆底表面肌电变化情况,并分别在治疗前后应用盆腔脏器官脱垂-尿失禁性功能问卷（PISQ-12）、国际尿控协会盆腔脏器脱垂定量分析量表（POP-Q）、尿失禁问卷表简表（ICI-Q-SF）评估两组患者的性功能、盆腔脱垂程度及尿失禁情况,并对比治疗前后血清RLX、CTGF和MMP-1表达水平。结果：观察组总有效率93.33%明显高于对照组78.67%（P＜0.05）;两组患者治疗前耐力收缩（Ⅱ类肌）、持续收缩和快速收缩（Ⅰ类肌）、前静息电位、后静息电位肌电水平对比无差异（P＞0.05）,治疗后观察组快速收缩（Ⅰ类肌）高于对照组（P＜0.05）,静息电位与后静息电位低于对照组（P＜0.05）;两组患者治疗前PISQ-12、POP-Q和ICI-Q-SF评分对比无明显差异（P＞0.05）,治疗后两组患者PISQ-12、ICI-Q-SF评分升高,观察组较对照组高,POP-Q评分均降低,观察组较对照组低（P＜0.05）;两组患者治疗前RLX、CTGF和MMP-1表达水平对比无差异（P＞0.05）,治疗后两组患者RLX、CTGF和MMP-1表达水平均降低,且观察组低于对照组（P＜0.05）。结论：补中益气汤联合低频脉冲电刺激可提升产后盆底功能障碍的临床疗效,改善盆底肌表面肌电变化,改善患者性功能、盆腔脱垂程度及尿失禁情况,且能够降低血清松弛素、CTGF和MMP-1表达水平。     

The role of pollinators in maintaining variation in flower colour in the Rocky Mountain columbine,Aquilegia coerulea

Background and Aims Flower colour varies within and among populations of the Rocky Mountain columbine, Aquilegia coerulea, in conjunction with the abundance of its two major pollinators, hawkmoths and bumble-bees. This study seeks to understand whether the choice of flower colour by these major pollinators can help explain the variation in flower colour observed in A. coerulea populations.Methods Dual choice assays and experimental arrays of blue and white flowers were used to determine the preference of hawkmoths and bumble-bees for flower colour. A test was made to determine whether a differential preference for flower colour, with bumble-bees preferring blue and hawkmoths white flowers, could explain the variation in flower colour. Whether a single pollinator could maintain a flower colour polymorphism was examined by testing to see if preference for a flower colour varied between day and dusk for hawkmoths and whether bumble-bees preferred novel or rare flower colour morphs.Key Results Hawkmoths preferred blue flowers under both day and dusk light conditions. Naïve bumble-bees preferred blue flowers but quickly learned to forage randomly on the two colour morphs when similar rewards were presented in the flowers. Bees quickly learned to associate a flower colour with a pollen reward. Prior experience affected the choice of flower colour by bees, but they did not preferentially visit novel flower colours or rare or common colour morphs.Conclusions Differences in flower colour preference between the two major pollinators could not explain the variation in flower colour observed in A. coerulea. The preference of hawkmoths for flower colour did not change between day and dusk, and bumble-bees did not prefer a novel or a rare flower colour morph. The data therefore suggest that factors other than pollinators may be more likely to affect the flower colour variation observed in A. coerulea.     

杂色山雀(Parus varius)亲代喂食与子代乞食间的行为交流

在育雏期,晚成鸟的子代一般都是由双亲共同来抚育,子代为了更好地存活,会用自己的方式竞争获得更多的食物和更好的生存空间,同时亲代也会通过子代的乞食信号来分配食物。2011年3月-7月采用针孔摄像技术录制了杂色山雀(Parus varius)育雏期巢内亲代与子代间的行为交流,统计了亲鸟站位、雏鸟站位、雏鸟乞食强度及亲鸟的喂食情况等数据。分析结果表明：(1)雌雄亲鸟在巢中的站位各有特点：雄鸟在整个育雏期都喜欢站在距离巢口较近的位置;雌鸟站位不太固定,前期离巢口相对较远,中期和后期离巢口相对较近;(2)雏鸟离亲鸟越近,乞食强度越大,获得食物的机会就越多;(3)杂色山雀主要是雌鸟担任育雏任务,喂食频率远大于雄鸟;(4)育雏期的不同阶段雏鸟乞食强度、亲鸟喂食频率变化很大：中期雏鸟乞食强度最大,亲鸟喂食频率最高,后期雏鸟乞食强度最弱;(5)整个育雏期雌性亲本没表现出明显的偏爱行为,但雄性亲本在中期表现出了偏爱大的雏鸟。