应用资源选择函数研究朱鹮的巢址选择

本文介绍了资源选择函数的原理与方法,并分析了朱鹮(Nipponia nippon)的巢址选择我们将上述结果与主成分分析的结果进行了比较,发现两种方法都显示水田面积、营巢树高度海拔高度和人类干扰程度对朱鹮巢址选择有较大影响,而巢向、巢上郁闭度、坡向和坡度对朱鹮影响较小。然而,两种方法也有明显的差异：资源选择函数显示营巢地的坡位非常重要而主成分分析显示植被密度比较重要。分析表明资源选择函数更好地反映了多种生境因素对朱鹮巢址选择的影响。本文探讨了应用资源选择函数所必须注意的对照样方选择和参数的独立性问题,并提出了对朱鹮保护工作的建议。     

朱Huan冬季觅食地的选择

在无线电遥测的基础上,采用样方法对朱Ｈuan冬季觅食地进行了调查。朱Huan冬季觅食地有冬水田、河流浅滩和水库３种类型。成鸟与幼鸟的主要觅食地类型及分布有明显的差别。位于海拔６００－１００0m的低山区冬水田是朱Ｈuan成鸟 冬季最重要的觅食地,幼鸟我在汉江流域的河流及浅滩中觅食。对冬水田的主要栖息地特征的方差分析和因子分析的结果表明,影响朱Ｈuan食地选择的主要因子为觅食地的海拔高度,开阔度、面积及人类活动的干扰程度等。冬水田的恢复及保护对朱Ｈuan的保护有着重要的意义。     

四川南充农田区乌鸫的巢址选择

2007年3～5月在四川省南充市近郊农田区域对乌鸫Turdus merula sowerbyi的巢址选择进行了研究.共调查57个巢址样方,通过主成分分析(PCA)提取到影响乌鸫巢址选择的6个主要因子,其累积贡献率达74.44%, 其中乔木因子的贡献率最高,达26.58%.农田区中,乌鸫在4月中旬开始营巢,营巢树平均高度为16.02±2.29 m,主要巢树种类是白杨.     

四川南充市夜鹭的巢址选择

2006年3~6月,在四川省南充市太和保护区对夜鹭的巢址选择进行了研究。野外调查了夜鹭巢47个,对照样方26个,通过主成分分析和对比分析,表明影响夜鹭巢址选择的主要因子依次为:营巢树高度、植被平均高度、巢高、竹平均直径、隐蔽度、巢上方盖度、距水(西河)距离、距白鹭巢距离、植被盖度、巢下盖度。     

陕西洋县朱Huan活动区的鸟类

1999年1月至2002年1月,在陕西省洋县进行朱Huan研究过程中,对当地鸟类进行了长期,系统的观察,记录到鸟类16目48科116属,共201种。     

洋县野生朱Huan的繁殖

朱鹮(Nipponia nippon)的繁殖状况 ,尤其是种群数量的变化 ,一直受到国内外的关注。本文收集分析了 1 981～ 1 997年 1 7年朱繁殖资料 ,进一步研究了朱的繁殖及其数量 ,以期为朱保护 ,采取行之有效的措施 ,提供科学依据。1　研究方法自 1 981年朱被重新发现后 ,至 1 997年 ,每年3～ 6月繁殖期 ,固定人员 ,2～ 3人为 1组 ,在每个巢区设立观察点 ,进行跟踪观察 ,并详细统计每窝产卵数、孵化数、雏鸟成活数和死亡数。并结合平常的跟踪监护 ,调查分析种群数量动态 ,统计成鸟死亡数 ,然后进行整理分析。2　结果与讨论2 .1　种群数量1 98…     

甘肃盐池湾斑头雁巢址选择

2019年4至6月,采用定点观察法和样方法研究甘肃盐池湾国家级自然保护区斑头雁(Anser indicus)巢址选择。研究期间共发现斑头雁巢332个,斑头雁在繁殖期有3种营巢生境,即浅水沼泽、湖心小岛以及山崖,其巢址类型有草垛巢、地面巢和山崖裸岩巢3种。浅水沼泽、湖心小岛以及山崖3种营巢生境中窝卵数分别为(4.7±2.7)枚(n=204)、(4.2±1.9)枚(n=108)及(3.1±0.6)枚(n=20),孵化成功率分别为48.65%(n=199)、45.27%(n=148)及24.00%(n=25),繁殖成功率分别为66.67%(n=42)、74.28%(n=35)及36.36%(n=11)。主成分分析显示,影响浅水沼泽生境中斑头雁巢址选择的主要环境因素依次为水源因素、隐蔽因素、干扰因素和食物因素;影响湖心小岛生境中斑头雁巢址选择的主要环境因素依次为隐蔽因素、食物因素、干扰因素;影响山崖生境中斑头雁巢址选择的主要环境因素依次为地形因素、食物及水源因素、干扰因素。本研究表明,斑头雁在不同营巢生境中,巢址选择的最主要环境因素并不相同,主要依赖生境特征及周围环境因素特征。     

朱鹮野化种群对冬季低温的行为响应

低温对鸟类的生长发育、新陈代谢和生活状态有显著的影响,鸟类往往通过改变行为模式来适应温度的变化。朱鹮(Nipponia nippon)是东亚特有的濒危鸟类,2018年从秦岭南麓的陕西洋县引入到河北北戴河,建立了全球纬度最高的野化种群。本文以北戴河和洋县两个野化种群为研究对象,采用瞬时扫描法观察分析了季节和温度等因素对朱鹮休息行为的影响。结果表明,双腿站立露喙是朱鹮在游荡期最常见的休息行为(70.9%),但在越冬期显著降低(55.6%),而单腿站立和隐喙行为比例相应升高。温度对双腿站立隐喙、单腿站立露喙和单腿站立隐喙3种行为的比例有显著影响。可见,朱鹮在冬季通过增加保护裸露部位的行为比例来适应低温。在冬季,随着温度的下降,朱鹮趴卧在树干上的夜宿行为比例逐渐增加,而这一行为在白天没有记录到。温度对成鸟和幼鸟冬季的休息行为有显著影响。由此表明,趴卧行为很可能是朱鹮对极端耐受低温的一种应对,在保护监测过程中需警惕。朱鹮在北戴河越冬过程中没有使用网笼中的遮挡伞棚和庇护场所,表明其能够自主适应-20℃的低温。为了确保野化朱鹮顺利越冬,建议在野化网笼中增加一些松科等常绿树种,为朱鹮提供更加优良的夜宿环境,并用稻草搭建风挡,减少夜间大风的负面影响。     

陕西宁陕野化放飞朱鹮秋季觅食地选择与食物丰富度

于2008年秋季应用样方法对陕西宁陕县寨沟野化放飞朱鹮(Nipponia nippon)的觅食地和食物丰富度进行了调查。结果表明,朱鹮秋季的主要觅食地是冬水田,影响朱鹮觅食地选择的主要因素是人为干扰、觅食地开阔度和土壤松软程度;宁陕野化放飞区朱鹮觅食地中共发现记录动物36种,冬水田翻耕对朱鹮的食物丰富度和生物量无显著影响。总体上,在秋季游荡期朱鹮的食物并不丰富。     

Evolution of tryptophan biosynthetic pathway in microbial genomes: a comparative genetic study

Biosynthetic pathway evolution needs to consider the evolution of a group of genes that code for enzymes catalysing the multiple chemical reaction steps leading to the final end product. Tryptophan biosynthetic pathway has five chemical reaction steps that are highly conserved in diverse microbial genomes, though the genes of the pathway enzymes show considerable variations in arrangements, operon structure (gene fusion and splitting) and regulation. We use a combined bioinformatic and statistical analyses approach to address the question if the pathway genes from different microbial genomes, belonging to a wide range of groups, show similar evolutionary relationships within and between them. Our analyses involved detailed study of gene organization (fusion/splitting events), base composition, relative synonymous codon usage pattern of the genes, gene expressivity, amino acid usage, etc. to assess inter- and intra-genic variations, between and within the pathway genes, in diverse group of microorganisms. We describe these genetic and genomic variations in the tryptophan pathway genes in different microorganisms to show the similarities across organisms, and compare the same genes across different organisms to find the possible variability arising possibly due to horizontal gene transfers. Such studies form the basis for moving from single gene evolution to pathway evolutionary studies that are important steps towards understanding the systems biology of intracellular pathways.     

Partitioning the Relative Contributions of Inorganic Plant Composition and Soil Characteristics to the Quality of Helichrysum italicum subsp. italicum (Roth) G. Don fil. Essential Oil

Composition of Helichrysum italicum subsp. italicum essential oil showed chemical variability according to vegetation cycle, environment, and geographic origins. In the present work, 48 individuals of this plant at different development stages and the corresponding root soils were sampled: i) 28 volatile components were identified and measured in essential oil by using GC and GC/MS; ii) ten elements from plants and soils have been estimated using colorimetry in continuous flux, flame atomic absorption spectrometry, or emission spectrometry (FAAS/FAES); iii) texture and acidity (real and potential) of soil samples were also reported. Relationships between the essential‐oil composition, the inorganic plant composition, and the soil characteristics (inorganic composition, texture, and acidity) have been established using multivariate analysis such as Principal Component Analysis (PCA) and partial Redundancy Analysis (RDA). This study demonstrates a high level of intraspecific differences in oil composition due to environmental factors and, more particularly, soil characteristics.     

Metabolic Discrimination of Catharanthus roseus Calli According to Their Relative Locations Using 1H-NMR and Principal Component Analysis

Creating a plant-cell suspension culture involves first transferring the callus into liquid media, but there are no objective criteria for selecting the location of the callus to be transferred. In this study, inner and outer cells of Catharanthus roseus with various elicitors in solid-state cultures were differentiated by ¹H NMR (nuclear magnetic resonance) spectrometry and principal component analysis (PCA). It was found that the samples of various elicitors and relative locations could be separated in PCA-derived score plots. Especially, there was a clear separation between nontreated samples and those cotreated with silver nitrate and methyl jasmonate. Loading-plot analysis was therefore applied to data obtained from nontreated samples and those cotreated with silver nitrate and methyl jasmonate to determine the separation of major metabolites on score plots. The levels of valine, lactic acid, threonine, alanine, arginine, acetic acid, malic acid, succinic acid, citric acid, asparagine, choline, lactose, fumaric acid, phenylalanine, tryptophan, and formic acid were higher in the inner callus than in the outer callus, whereas 2-oxoglutaric acid, oxalacetic acid, sucrose, and glucose dominated in the outer callus. The results obtained in this study suggest that inner and outer calli can be differentiated by ¹H-NMR-based metabolomic analysis.     

A strategy to develop molecular markers applicable to a wide range of crosses for marker assisted selection in plant breeding: a case study on anthracnose disease resistance in lupin (Lupinus angustifolius L.)

A key challenge in marker-assisted selection (MAS) for molecular plant breeding is to develop markers linked to genes of interest which are applicable to multiple breeding populations. In this study representative F₂ plants from a cross Mandalup (resistant to anthracnose disease) × Quilinock (susceptible) of Lupinus angustifolius were used in DNA fingerprinting by Microsatellite-anchored Fragment Length Polymorphism (MFLP). Nine candidate MFLP markers linked to anthracnose resistance were identified, then ‘validated’ on 17 commercial cultivars. The number of “false positives” (showing resistant-allele band but lack of the R gene) for each of the nine candidate MFLP markers on the 17 cultivars ranged from 1 to 9. The candidate marker with least number of false positive was selected, sequenced, and was converted into a co-dominant, sequence-specific, simple PCR based marker suitable for routine implementation. Testing on 180 F₂ plants confirmed that the converted marker was linked to the R gene at 5.1 centiMorgan. The banding pattern of the converted marker was consistent with the disease phenotype on 23 out of the 24 cultivars. This marker, designated “AnManM1”, is now being used for MAS in the Australian lupin breeding program. We conclude that generation of multiple candidate markers, followed by a validation step to select the best marker before conversion to an implementable form is an efficient strategy to ensure wide applicability for MAS.     

Activated NF-κB/Nrf2 and Wnt/β-catenin pathways are associated with lipid metabolism in CKD patients with microalbuminuria and macroalbuminuria

Early diagnosis of CKD patients at risk for microalbuminuria or macroalbuminuria could facilitate clinical outcomes and long-term survival. Considering the few and limited efficacy of current biomarkers in early detection, we aim to discover plasma lipids that effectively predict the development of CKD paitents with microalbuminuria or macroalbuminuria. A total of 380 healthy controls and 1156 patients with CKD stages 3 to 5 were stratified by urine albumin-creatinine ratio as microalbuminuria (30–300 mg/g) and macroalbuminuria (>300 mg/g). Fasting plasma samples were determined by UPLC-HDMS based on lipidomics. Quantitative real-time polymerase chain reaction, Western blot and immunohistochemical analyses were used to validate the lipid metabolism-associated pathways. Pathway analysis demonstrated that these lipids were closely associated with PPARγ, inflammatory mediator regulation of TRP channels and RAS signaling, which were intimately involved in activated NF-κB and Nrf2 pathways. We further carried out pathway validation and demonstrated that NF-κB pathway was activated in patients with macroalbuminuria compared with CKD patients with microalbuminuria, while Nrf2-associated protein expression was downregulated, which was accompanied by the up-regulation of Wnt/β-catenin signaling pathway. Four lipids including DTA, 5,8-TDA, GGD3 and DHA that showed great potential in the discrimination of CKD patients with microalbuminuria and healthy controls were selected by logistic regression analysis. Additionally, six lipid species including CDCA, glucosylceramide, GGD2, TTA, DHA and EDA that contributed to the discrimination of CKD patients with microalbuminuria and macroalbuminuria were selected by logistic LASSO regression Gangliosides were first identified and might be promising therapeutic targets for CKD patients with the different degree of albuminuria. Collectively, this study first demonstrates the association of plasma inflammation, oxidative stress, Wnt/β-catenin and lipid metabolism in CKD patients with microalbuminuria and macroalbuminuria.