A new method for identifying rapid decline dynamics in wild vertebrate populations

Tracking trends in the abundance of wildlife populations is a sensitive method for assessing biodiversity change due to the short time‐lag between human pressures and corresponding shifts in population trends. This study tests for proposed associations between different types of human pressures and wildlife population abundance decline‐curves and introduces a method to distinguish decline trajectories from natural fluctuations in population time‐series. First, we simulated typical mammalian population time‐series under different human pressure types and intensities and identified significant distinctions in population dynamics. Based on the concavity of the smoothed population trend and the algebraic function which was the closest fit to the data, we determined those differences in decline dynamics that were consistently attributable to each pressure type. We examined the robustness of the attribution of pressure type to population decline dynamics under more realistic conditions by simulating populations under different levels of environmental stochasticity and time‐series data quality. Finally, we applied our newly developed method to 124 wildlife population time‐series and investigated how those threat types diagnosed by our method compare to the specific threatening processes reported for those populations. We show how wildlife population decline curves can be used to discern between broad categories of pressure or threat types, but do not work for detailed threat attributions. More usefully, we find that differences in population decline curves can reliably identify populations where pressure is increasing over time, even when data quality is poor, and propose this method as a cost‐effective technique for prioritizing conservation actions between populations.     

泡桐丛枝植原体tRNA异戊烯基焦磷酸转移酶基因克隆、原核表达及功能分析

【目的】为了鉴定植原体tRNA异戊烯基焦磷酸转移酶基因(tRNA-ipt)的表达及蛋白功能,探索植原体致病机理。【方法】对泡桐丛枝、桑萎缩、长春花绿变及苦楝丛枝植原体tRNA-ipt基因完整序列进行PCR扩增和生物信息学分析。对泡桐丛枝植原体tRNA-ipt基因进行原核表达并制备抗体。利用Western blot和FITC间接免疫荧光显微镜检测其在植原体中的表达。使用分光光度计分析该基因对大肠杆菌生长的影响,用ELISA测定转化菌株细胞分裂素含量。【结果】首次发现泡桐丛枝、桑萎缩、长春花绿变及苦楝丛枝植原体中完整tRNA-ipt基因,大小为876 bp,编码291个氨基酸,且N端均含有ATP/GTP结合位点保守序列(GPTASGKT)。4种植原体tRNA-IPT之间的氨基酸序列相似率为99.1%-99.5%,与同组植原体同源性在95.4%-99.3%,与其他组植原体同源性低于70%。SDS-PAGE结果显示tRNA-IPT蛋白在大肠杆菌中得到表达。首次获得泡桐丛枝植原体tRNA-IPT抗体并检测到该蛋白在泡桐发病组织中的特异表达。经过对转化菌株生长曲线及玉米素含量的测定,发现该基因能促进大肠杆菌后期生长和玉米素核苷的积累。【结论】4种植原体tRNA-ipt基因编码相同特性的功能蛋白,泡桐丛枝植原体tRNA-IPT蛋白能够在植原体中表达,根据该基因对异源菌株生长速率和激素合成的影响推断该蛋白可能参与植原体的细胞分裂素合成,在致病过程中起到重要作用。     

海南橡胶林植物多样性特征

为探讨人工林物种多样性维持机制及人为干扰后人工林群落的多样性恢复机制, 作者依据自然林的核心理论建立了一个1 ha的橡胶(Hevea brasiliensis)林固定样地, 通过研究近自然管理后样地内植物物种组成与分布来探讨近自然管理后橡胶林生物多样性的特征。结果表明: 近自然管理后橡胶林群落物种多样性较高, 1 ha样地内共有植物69科155属183种。在面积为4,000 m²、3,000 m²和2,000 m²时分别包含了样地内大约90%的种、属和科; 逻辑斯蒂模型拟合拟合种-面积曲线效果较好(R²=0.997), 证明了1 ha取样尺度可以满足橡胶林群落物种多样性研究的需要。多度-面积曲线和丰富度-面积曲线与随机分布模型有明显的差异, 表明橡胶林群落内个体数及物种分布呈非随机性。(4)对数级数模型和对数正态模型拟合橡胶林群落的种-多度分布都不理想, 相比而言后者拟合效果稍好。     

美味猕猴桃净光合速率日变化与光合特性的初步研究

在春季田间条件下,我们对美味猕猴桃品种米良１ 号（Ａｃｔｉｎｉｄｉａ ｄｅｌｉｃｉｏｓａ ｃｖＭｉｌｉａｎｇ－１）的光－光合特性与净光合速率日变化及其与环境因子的关系进行了初步研究．结果表明美味猕猴桃米良１ 号在适宜的环境条件下（气温３４ ℃,相对湿度６２％ ）,同化ＣＯ２ 的光合速率达到１７．３７～１８．６９ μｍ ｏｌｍ － ２ｓ－ １,但是在高温和干旱条件下（气温４１℃,相对湿度３０％ ）,其光合能力降低到７．３２ μｍ ｏｌｍ － ２ｓ－ １．该品种的光饱和点与光补偿点分别为１ １００ 和２０ μｍ ｏｌｍ － ２ｓ－ １, 表明是一种阴性偏阳的树种． ５ 月初的晴天,美味猕猴桃米良１号的净光合速率日变化呈双峰曲线型,第一高峰出现在上午１０∶００,１８．６５ μｍ ｏｌｍ － ２ｓ－ １,午间１３∶００ 剧降到３．１５ μｍ ｏｌｍ － ２ｓ－ １,下午１６∶００ 出现第二高峰,其值为１０．３５ μｍ ｏｌｍ － ２ｓ－ １． 在测定净光合速率的同时,还对田间条件下环境因子如光照、气温、空气湿度与ＣＯ２浓度以及植物叶表面温度与蒸腾速率日变化等进行了监测,用多元线形回归的方法分析了环境因子对猕猴桃光合作用日变化的影响     

Responses of Antarctic Iridaea cordata (Rhodophyta) tetraspores exposed to ultraviolet radiation

In Antarctica ozone depletion is highest during spring, coinciding with the reproduction of many seaweed species. Propagules are the life-stage of an alga most susceptible to environmental perturbations. Therefore, fertile thalli of Iridaea cordata (Turner) Bory (Rhodophyta) were collected in the eulittoral of King George Island (Antarctica) to examine spore susceptibility to ultraviolet radiation (UVR). In the laboratory, freshly released tetraspores were exposed to photosynthetically active radiation (PAR) (400–700 nm), PAR+UV-A (320–700 nm) or PAR+UV-A+UV-B (280–700 nm). Photosynthetic efficiency was measured during 1–8 h of exposure and after 48 h of recovery. Additionally, mycosporine-like amino acids (MAAs) and DNA damage were determined. Saturating irradiance of photosynthesis of freshly released tetraspores was 57 µmol photons m⁻² s⁻¹. Exposure to increasing fluence of PAR reduced photosynthetic efficiency. UVR further decreased the photosynthetic efficiencies of the tetraspores but spores were able to recover completely after UVR exposure and 2 days post-cultivation under low PAR. DNA damage was minimal and lesions were effectively repaired under photoreactivating light. Concentrations of the MAAs shinorine and palythine were higher in tetraspores treated with UVR than in spores only exposed to PAR. Generally, the tetraspores show a good UV tolerance. This flexible response of the tetraspores of this species to changing radiation conditions enables the alga to grow along a considerable depth gradient from the sublittoral to the eulittoral where they can be exposed to enhanced UVBR under conditions of stratospheric ozone depletion.     

快速叶绿素荧光动力学及其在植物抗逆生理研究中的应用

快速叶绿素荧光动力学是研究光合原初反应的无损探针,可监测光合反应的多个事件,并能反应植物的生理状况,可以应用于环境物理及化学条件胁迫对植物的影响(如化肥及除草剂的使用;CO2、O2、O3浓度的变化及温度、光强度胁迫等);也应用于农业生产(如确定耕作方式及日常管理;除草剂、杀虫剂及激素的使用;品种选优等);更是光合生理研究的便捷工具。介绍了快速叶绿素荧光动力学中的JIP-test分析方法,并从光、水分、温度、盐等多个方面介绍了JIP-test方法在植物抗逆生理研究中的应用。     

昆虫发育进度的非正态描述──分段指数曲线

提出了分段连续指数曲线转化为多元线性回归方程的方法。利用取剩余平方和最小的方法确定未知折点。给出了在描述昆虫发育进度的模拟模型。     

Urinary proteomics revealed prostaglandin H(2)D-isomerase, not Zn-α2-glycoprotein, as a biomarker for active lupus nephritis

Although renal histopathology is the gold standard for the diagnosis and prognosis of lupus nephritis (LN), the invasiveness of renal biopsy warrants the discovery of novel non-invasive diagnostic and prognostic biomarkers. In the present study, urine samples from 10 LN patients (5 active and 5 inactive) were analyzed by two-dimensional gel electrophoresis (2-DE) to screen for potential biomarkers of active LN. Quantitative analysis and statistics revealed 16 protein spots whose levels significantly differed between groups. These proteins were successfully identified by electrospray ionization quadrupole time-of-flight tandem mass spectrometry (ESI-Q-TOF MS/MS). Among these potential candidates, differential levels of urinary Zn-α2-glycoprotein (ZA2G) and prostaglandin H(2)D-isomerase (PGDS) were further validated by enzyme-linked immunosorbent assay (ELISA) in another independent group of 78 subjects, including 30 active LN, 26 inactive LN, 14 non-LN glomerular diseases, and 8 healthy normal individuals. Whereas ZA2G levels were elevated in urine of patients with active LN and non-LN glomerular diseases, PGDS was elevated only in the urine of the active LN group. Urinary PGDS, not ZA2G, may serve as a biomarker for active LN and upon validation in larger studies, may become the non-invasive test to evaluate the disease activity in future management of LN.     

Species Composition, Abundance, and Distribution of Seabirds along the Northeastern Coast of Sakhalin

Seabirds were counted in September 1998 from the research vessel Professor Khromovand a motorboat in Pil'tun and Lunskii bays and in the contiguous areas of the eastern Sakhalin shelf. Data on the species composition, abundance, and distribution of seabirds are presented. A fairly high species diversity and significantly high density of seabirds were recorded in Pil'tun and Lunskii bays, which are the main areas where they concentrate during the summer months.     

冀西北坝上地区灯下蛾类群落结构特征

对冀西北坝上地区蛾类进行了逐日灯诱监测,以微软系统的Excel列表、作图,进行蛾类群落的种-多度曲线作图及群落多样性(H')、均匀度(J')、物种丰富度(S)和个体数(N)的时间和空间分布的处理,并做了多样性分析。结果表明:该区蛾类已知16科173属247种,夜蛾科是该区蛾类的优势类群,旋幽夜蛾、网锥蛾野螟(草地螟)和小菜蛾为当地优势种。从5月到9月蛾类多样性指数、物种丰富度和个体数基本呈上升趋势,多样性指数与均匀度(r=0.9477)、物种数(r=0.7785)、个体数(r=0.9704)相一致。不同月份间的蛾类相似程度差异较大,种-多度关系符合对数正态分布模型,研究认为坝上地区蛾类赖以生存的生态环境稳定,生态环境条件保持较好。