Immunohistochemical demonstration of urotensins I and II in the caudal neurosecretory system of the Japanese charr,Salvelinus leucomaenis,retained in sea water

This paper is concerned with part of the role and function of the caudal neurosecretory system of the charr,Salvelinus leucomaenis, studied by immunohistochemistry. In order to elucidate the different histologic changes, we examined the immunoreactivities of urotenisn I (UI) and urotensin II (UII) in 3 experimental groups: the feral (river) fish, the fresh-water aquarium-, and sea water aquarium-retained fish. Coexistence of UI and UII was demonstrated in most of the smaller and larger neurons distributed in and near the urophyseal system of all 3 groups. However, some of the larger neurons were immunoreactive only to a single hormone, UI or UII. Merely a few neurons indicated no reactivity for either UI or UII. No such clearcut differences were encountered immunohistochemically in the 3 groups. Neuronal and urophysial immuno-reactivity to UI of feral and fresh-water-retained fish was slightly stronger than that of sea water-retained fish. Moreover, in sea water-retained fish, the intensity of immunoreactivity for UI was variable, and the number of neurons positive for UII only was somewhat larger than that in feral and fresh-water-retained fish. A series of UII-positive cerebrospinal fluid (CSF)-contacting neurons were seen in the ependymal and subependymal layers ventral to the central canal of the spinal cord in every group. These CSF-contacting neurons might constitute another neurosecretory system aside from the ordinary caudal neurosecretory system equipped with urophysis. In contrast to the hypothalamohypophysial neurosecretory system, the caudal neurosecretory system did not show any significant changes among the 3 groups. This suggests that urotensins I and II have no essential role in osmoregulation of the charr.     

Relationship Between Time- and Frequency-Domain Analyses of Angular Head Movements in the Squirrel Monkey

We used the three-dimensional magnetic search-coil recording technique to study the range of active angular head movements made by squirrel monkeys. There were two goals in this study: (1) to determine the range of angular velocities and accelerations as well as the bandwidth and other frequency characteristics of active head movements and (2) to compare analyses of transients of velocity and acceleration that are studied by residual analysis, Fourier transform, and wavelet transform of the head velocity signal.The residual analysis showed that the shape and duration of the transients affected the bandwidth. During the time after the head had begun to accelerate, the frequency content of the head movement extended into the range of 6 to 12 Hz. When considering all three planes of rotation, approximately 75% of the transients had peak acceleration between 2,000 and 10,000 deg/s² and a peak velocity of 50 to 400 deg/s. A peak acceleration of >10,000 deg/s² was recorded in 10% of the transients.These findings indicate that active head movements in squirrel monkeys cover a higher range of frequencies, accelerations, and velocities than have typically been used in previous eye-movement and neuronal studies of the reflexes that control gaze. We further conclude that the choice of a method for analyzing transient, time-varying biological signals is dependent on the desired information. Residual analysis provides detailed resolution in the time domain, but estimation of the frequency content of the signal is dependent on the portions selected for analysis and the choice of filters. Fourier transform provides a representation of the power spectrum in the frequency domain but without any inherent temporal resolution. We show that the wavelet transform, a novel method as applied to the signal analysis goals of this study, is the most useful technique for relating time- and frequency-domain information during a continuous signal.     

Genetic diversity and population structure of white-spotted charr, Salvelinus leucomaenis, in the Lake Biwa water system inferred from AFLP analysis

The genetic variations—and the time dependence of such variations—of natural populations of the white-spotted charr ,Salvelinus leucomaenis, in the Lake Biwa water system as well as those of a hatchery-reared population were inferred from AFLP. Upon the application of principal coordinate analysis using 118 polymorphic AFLP fragments based on the Jaccard similarity index, specimens of each of six natural local populations from the inlet rivers of Lake Biwa grouped roughly together, suggesting that each local population was genetically differentiated. The hatchery-reared population was shown to be closely related to the local population in the Seri River, suggesting that the Seri River population originated from hatchery-reared charr due to extensive stocking. Furthermore, specimens of the Yasu River grouped in a somewhat different position from the other natural populations, agreeing well with its geographic distance from the other populations. The nucleotide diversities of six natural populations (Harihata River, Ishida River, two reaches of the Takatoki River, Ane River, and Yasu River) in 2002 or 2003 were relatively low (π = 0.067–0.146%) compared with that of the Seri River (0.278%) and the hatchery-reared charr (0.316%). The nucleotide diversity in the five local populations (Ishida River, two reaches of the Takatoki River, Ane River, and Yasu River) remained at a low level from 1994 to 2002/2003, but only the nucleotide diversity in the Harihata River actually decreased. From 1994 to 2002/2003, the nucleotide diversity in the Seri River remained at a higher level among the natural populations from 1994 to 2002/2003; it was enhanced by the artificial release of hatchery-reared charr before 1994. In order to conserve the genetic diversity of the white-spotted charr in the Lake Biwa water system, it is necessary to prevent the stocking of hatchery-reared charr in reaches where hatchery-reared charr have not previously been stocked.     

Interrelationships Between Arteries,Veins and Lymphatics in the Head Region of the Eel,Anguilla anguilla L.

Vascular casting and dissection of fresh specimens had been used to investigate the arrangement of vessels before and after the gills in the head region of the eel. Arterial and venous morphology was found to be as reported in previous works, but the presence in the eel of a venous system that does not confom to the generalised teleost plan necessitated the use of a non-standard nomenclature. The gills are the site of the connection of the arterial system with a second vascular system and it is suggested that this system should be termed the veno-lymphatic system. The veno-lymphatic system connects dorsally to the systemic lymphatic system and so to the internal jugular vein. Ventrally the veno-lymphatic vessels from the first three gill arches are collected into a connective tissue sheath around the ventral aorta. The sheath is connected to a veno-lymphatic sinus posterior to it which also collects the veno-lymphatic of the fourth gill arch. This sinus then drains into the external jugular vein which at this point is the fusion of the left and right branches. These later separate and each branch contains a valve preventing flow towards the ventral aortic sheath. It is proposed that because of the form of this ventral route for veno-lymphatic drainage, and the ease and completeness of filling of this route compared with the dorsal route, that the ventral veno-lymphatic system is probably the primary route of drainage of veno-lymphatic outflow from the gills.     

Species Diversity and Altitudinal Gradient Patterns of Evergreen Broad leaved Forest in MeihuashanNational Natural Reserve,Fujian Province

In China, evergreen broad leaved forests (EBLFs) is one of the most important vegetation types which was widly distributed in subtropical area, and it plays a very important role in the global biological diversity and natural environment conservation also. In order to reveal species diversity and altitudinal gradient patterns of evergreen broad leaved forest in Meihuashan National Natural Reserve, Fujian Province. Five altitude transects were set up at a vertical interval of 200m between 375m and 1300m above sea level in the EBLFs distribution areas, and twenty four quadrats(14400m2) had been surveyed. Species richness(S), species richness index (dGl), Simpson index (D), Shannon Wiener index (H′), Pielou evenness index (J) had been used for analysis of species diversity and altitudinal gradient pattern of EBLFs. The average value of S, dGl, H′,J and D were 64.42, 10.75, 5.75, 3.50, 0.58 respectively. The difference of community species diversity index(S, dGl, D, H′, and J) was extremely significant between transects, and the altitudinal gradient patterns of species diversity presented the unimodal variable trend, with a peak in the mid altitude(700m-900m). The species richness and Shannon Wiener index of different layer were ranked as shrub layer (include young tree and the plants between layers)>arbor layer>herb layer. The species richness of tree and shrub layer, and Shannon Wiener index of tree layer were significantly different between at transects, and trends of altitude gradient was similar to community. The Shannon Wiener index of shrub layer and herb layer, and the species richness of herb layer did not change significantly along elevation gradient. Therefore, plant species diversity distribution pattern presented a unimodal variable trend along an elevation gradient, and supported “mid domain model” in EBLFs of Meihuashan National Nature Reserve.     

山西吕梁山草本群落物种多样性的海拔梯度格局及与环境因子的关系

山地草本群落物种多样性的海拔梯度格局及其与环境因子的关系一直是生态学和地理学研究的热点问题。为探究吕梁山草本群落不同尺度物种多样性(α、β、γ多样性)的海拔梯度格局及其与环境因子的关系,该研究采用样方法在吕梁山从北向南选取管涔山、关帝山、五鹿山,并对每个山地划分出高、中、低3个海拔梯度,对草本群落物种多样性和环境因子进行调查分析。结果表明:(1)α多样性随海拔升高呈先升后减的单峰变化格局,峰值出现在中海拔;β多样性中Cody指数在1 900～2 000 m间出现峰值,而BrayCurtis指数出现最小值,表明1 900～2 000 m海拔带是草本群落物种更新速率和组成变化较快的过渡地带;γ多样性随海拔升高也呈先升后减的单峰变化格局(R²=0.406,P<0.01)。(2)海拔对温度、湿度变化的影响极其显著(P<0.01);海拔、温度、湿度等环境因子共同影响物种的α多样性,其中海拔是主要影响因素(P<0.05),温度、湿度影响不显著(P>0.05)。综上所述,吕梁山草本群落多样性在海拔梯度上多表现为"中间膨胀"变化格局,海拔变化是影响多样性变...     

Ground‐dwelling beetle assemblages in the northern Cape Floristic Region: Patterns,correlates and implications

Abstract Recent studies have both shown and predicted that global climate change will have a substantial influence on biodiversity. This is true especially of a global biodiversity hotspot, the Cape Floristic Region. Although the effects of predicted changes have been widely assessed for plants, little is known about how insect diversity in the region might be affected. In particular, patterns in and the correlates of diversity in the region are poorly understood, and therefore the likely affects of a changing abiotic environment on this significant group of organisms are not clear. Therefore, we investigate patterns in, and correlates of, epigaeic beetle (Tenebrionidae and Carabidae) diversity in one of the most climate change‐sensitive areas in the Cape Floristic Region, the Cederberg. In particular, we determine whether epigaeic beetle assemblage structure differs between the main vegetation types in the Cederberg (Strandveld, Mountain Fynbos and Succulent Karoo), how restricted these beetles are to specific vegetation types, and which environmental variables might be associated with site‐related differences in beetle richness and abundance. Sampling was undertaken during October 2002 and 2003 across an altitudinal gradient ranging from sea level (Lambert's Bay) to approximately 2000 m above sea level (Sneeukop, Cederberg) and down again to 500 m above sea level (Wupperthal) using pitfall traps. The environmental correlates of abundance and species density in the epigaeic beetles were similar to those identified previously for ants across the transect, with both taxa being positively related to several temperature variables. Several species showed habitat specificity and fidelity, and clear distinctions existed between the vegetation types across the transect. A larger proportion of the variance in tenebrionid species density was explained by environmental variables and spatial factors than for carabids. The most likely explanation for this difference is that the correlates might well reflect collinear historical processes, rather than a causal relationship between contemporary environmental variables and species density. If this is the case, it suggests that caution should be exercised when interpreting environmental correlates of species density, and making climate change predictions based on these correlates.     

Relationships Between Hydrology and Soils Describe Vegetation Patterns in Seasonally Flooded Tree Islands of the Southern Everglades, Florida

Tree island ecosystems are important and distinct features of Florida Everglades wetlands. We described the inter-relationships among abiotic factors describing seasonally flooded tree islands and characterized plant–soil relationships in tree islands occurring in a relatively unimpacted area of the Everglades. We used Principal Components Analysis (PCA) to reduce our multi-factor dataset, quantified forest structure and vegetation nutrient dynamics, and related these vegetation parameters to PCA summary variables using linear regression analyses. We found that, of the 21 abiotic parameters used to characterize the ecosystem structure of seasonally flooded tree islands, 13 parameters were significantly correlated with four principal components, and they described 78% of the variance among the study islands. Most variation was described by factors related to soil oxidation and hydrology, exemplifying the sensitivity of tree island structure to hydrologic conditions. PCA summary variables describing tree island structure were related to variability in Chrysobalanus icaco (L.) canopy cover, Ilex cassine (L.) and Salix caroliniana (Michx.) canopy cover, Myrica cerifera (L.) plot frequency, litter turnover, % phosphorus resorption of co-dominant species, and nitrogen nutrient-use efficiency. This study supported findings that vegetation characteristics can be sensitive indicators of variability in tree island ecosystem structure. This study produced valuable, information which was used to recommend ecological targets (i.e. restoration performance measures) for seasonally flooded tree islands in more impacted regions of the Everglades landscape.     

成年和老年小鼠脑蛋白质组双向电泳图谱比较

使用双向电泳(2-DE)比较成年和老年小鼠脑蛋白质差异,从分子水平初步探索老年脑蛋白整体变化规律.以固相pH梯度等电聚焦为第一向,SDS-聚丙烯酰胺凝胶水平电泳(PAGE)为第二向进行2-DE.图象分析软件Imagemaster^® 2D Elite分析电泳图谱.重复性实验结果显示,同组样品在三次不同实验中所得蛋白质斑点数目的相对标准差（变异系数）为4.43%±0.25%;同一蛋白质斑点在三次实验中等电点、分子质量和蛋白质量的相对标准差分别为8.76%±5.14%, 13.00%±4.22%和10.84%±9.16%.成年和老年小鼠脑组织2-DE图谱分别获得996和1256个蛋白质斑点,其中8个蛋白质在老年脑组织中含量降低,20个蛋白质斑点含量增加.另至少有4个蛋白质斑点在老年脑组织中缺失,14个蛋白质点为老年脑特有. 以上差异点的发现为研究脑老化和退行性疾病机理提供了有益的线索.     

秦岭中段山脊油松叶功能性状差异及其对海拔梯度的响应

山脊油松林是秦岭山地典型的群落类型之一,其在维持生物多样性及发挥生态服务功能等方面具有重要意义.该研究以山脊油松为对象,采用典型取样法研究了秦岭中段山脊油松10种叶功能性状沿海拔梯度的适应性变化规律.结果表明:(1)山脊油松1～3年生各叶龄叶的叶长(LL)、叶氮含量(LNC)、叶磷含量(LPC)和1年生叶的叶绿素[Ch...     

种间竞争梯度对白车轴草与其病原菌白车轴草单孢锈菌相互作用的影响（英文） 刘登义 Lars Ericson

 白车轴草(Trifolium repens)在与其病原菌白车轴草单孢锈菌(Uromyces trifolii-repentis)的长期相互作用中分化形成了抗病型(Resistance)无性系和易感型(Susceptibility)无性系。该研究工作旨在了解：1)在种间竞争不断增强的环境梯度中,抗病型无性系和易感型无性系的生长表现有何区别?2)在同样的实验条件下,分别对抗病型无性系和易感型无性系进行接种感染后,两者的生长表现又有何区别?在一严重感病的白车轴草自然种群中,分别标定17个抗病型无性系和14个易感     

青藏高原53种菊科植物种子中碳、氮、磷含量与种子大小和海拔的关系

以青藏高原东北缘广泛分布的53种常见菊科植物种子为研究材料,以重铬酸钾外加热法和流动注射分析仪测定种子中碳、氮、磷含量,探讨种子中碳、氮、磷组成及分配是否随种子大小及生境海拔高度变异,为进一步探讨植物对环境变化的响应提供理论依据。结果表明:(1)53种菊科植物种子大小差异显著,且随海拔升高种子有变小的趋势。(2)53种菊科植物种子中C、N、P含量及其比值差异显著,不同海拔梯度的物种种子中C、N、P含量及其比值差异不显著,但C、N含量有随海拔升高增加的趋势,而P含量有随海拔升高降低的趋势。(3)种子大小变异并不影响其C的相对含量,但N、P含量与种子大小呈显著负相关关系,C/N、C/P、N/P与种子大小呈显著正相关关系,即种子越小,种子中N、P相对含量越高。因此,高海拔条件下,种子中积聚相对较多的C、N可以为其生长发育初期提供较高的能量及较多的蛋白质合成,从而增强幼苗抵御恶劣环境条件的能力,提高幼苗的存活率;较小种子中相对较高的N、P含量可以为早期幼苗提供足够的蛋白质和核糖体,帮助幼苗快速生长,从而克服其产生较小幼苗的劣势。研究表明,植物种子中C、N、P含量随种子大小及海拔的变异趋势是一种适应性选择的结果。     

藏南布丹拉山南坡种子植物区系海拔格局分析

生态群落交错区通常因物种丰富、区系成分复杂而被视为关键带.藏南布丹拉山处在半湿润向半干旱的生态环境过渡带上,因其特殊的自然地理环境而有着丰富的山地植物多样性,但这一重要生态过渡区的种子植物组成和区系成分海拔分布格局目前尚缺乏了解.为了理清布丹拉山南坡种子植物区系成分及其垂直分布变化格局,该文通过野外植物群落的样方调查、...     

祁连山区演替先锋物种西藏沙棘的种群结构及动态对海拔梯度的响应

西藏沙棘(Hippophaetibetana)是青藏高原高寒区特有的低矮灌木和植被演替先锋物种,具有优良的水土保持功效,对高海拔环境表现出良好的生态适应性,但有关其种群结构及动态对海拔梯度的响应规律少有研究,阻碍了对西藏沙棘适应高寒生境生态策略的理解。青藏高原东北缘的祁连山区生态脆弱,乡土物种西藏沙棘常在海拔2 700–3 300 m的高寒退化草地呈斑块状分布,对该区水源涵养林的维持具有重要作用。该研究以祁连山区3个海拔(2 868、3 012、3 244 m)的西藏沙棘为研究对象,通过编制静态生命表及绘制存活曲线,分析西藏沙棘的种群结构特征和种群动态,并利用种群动态量化分析和时间序列模型定量研究其未来发展趋势。结果显示:1)西藏沙棘种群的基径、株高和冠幅均随海拔的升高而降低; 3个海拔种群均呈中龄期个体丰富,老幼龄期个体较少的纺锤型年龄结构,充足的中龄期个体可以维持种群短期稳定。2)种群存活曲线均为Deevey-II型,存活能力为低海拔>中海拔>高海拔;死亡率和消失率均较高,呈高海拔>低海拔>中海拔的趋势,3个海拔种群均缺乏幼苗,未来均将走向衰退,高海拔种群较...     

Variations in Soil Microbial Communities and Residues Along an Altitude Gradient on the Northern Slope of Changbai Mountain,China

Altitudinally-defined climate conditions provide specific vegetation types and soil environments that could influence soil microbial communities, which in turn may affect microbial residues. However, the knowledge is limited in terms of the degree to which microbial communities and residues present and differ along altitude. In this study, we examined the soil microbial communities and residues along the northern slope of Changbai Mountain, China using phospholipid fatty acid (PLFA) and amino sugar analysis, respectively. Soil samples were taken from five different vegetation belts defined by climates. Principal component analysis (PCA) revealed substantial differences in soil microbial community composition among study sites, appeared to be driven primarily by soil pH and C/N ratio on the first principal component (PC1) which accounted for 50.7% of the total sample variance. The alpine tundra was separated from forest sites on the second principal component (PC2) by a signifiscantly higher amount of fungal PLFA (18:2ω6,9). Soil pH and C/N ratio were also correlated with the ratios of Gram-positive to Gram-negative bacteria (Gm⁺/Gm⁻), glucosamine to galactosamine (GluN/GalN), and glucosamine to muramic acid (GluN/MurA). Both total PLFAs and amino sugars were positively correlated with soil organic carbon, inorganic nitrogen, available phosphorus and potassium. We concluded that soil pH and C/N ratio were the most important drivers for microbial community structure and amino sugar pattern, while substrate availability was of great importance in determining the concentrations of microbial communities and residues. These findings could be used to facilitate interpretation of soil microbial community and amino sugar data derived from measurements in latitude or managed forests.     

利用海拔差异模拟增温对高山森林土壤溶解性有机碳和有机氮含量的影响

在2010年5月—2011年4月和2011年5月—2012年4月2个培养周期内,采用原状土柱野外控制试验,利用海拔梯度变化研究了温度增加对川西高山森林土壤溶解性有机碳(DOC)和有机氮(DON)动态的影响.结果表明: 经模拟增温处理(降低海拔)的土壤有机层和矿质土壤层DOC和DON含量在2个连续培养周期内的各关键时期均呈现明显的动态变化.海拔3300和3000 m样地比海拔3600 m 样地土层DOC含量分别增加6.8和26.6 mg·kg^-1.海拔3600、3300和3000 m样地土层DOC含量均在第1个培养周期的生长季末最高,分别为408.0、317.9和448.2 mg·kg^-1,在第2个培养周期的生长季节中期最低, 分别为33.1、32.4和36.5 mg·kg^-1.与海拔3600 m样地相比,海拔3300和3000 m样地土层DON含量分别增加2.3和30.4 mg·kg^-1.除海拔3000 m样地以外,海拔3600和3300 m样地土层DON含量在第1个培养周期内的生长季节中期最高,分别为65.9和64.6 mg·kg^-1,在第1个培养周期内的融化期最低,分别为31.9和37.1 mg·kg^-1.模拟增温处理增加了样地内土壤有机层DOC和DON含量,降低了矿质土壤层DOC含量、土壤有机层及矿质土壤层DOC/DON值.土壤有机层DOC/DON值与DOC含量呈显著正相关,与DON含量呈显著负相关;矿质土壤层DOC/DON值与DOC含量呈显著负相关,与DON含量呈显著正相关.未来全球气候变暖可能通过影响高寒森林土壤温度和冻融循环格局,增加整个土层DOC和DON含量,进而影响高寒森林土壤碳、氮循环过程.     

Seasonal abundance and the re-establishment of iwana charr Salvelinus leucomaenis f. pluvius after excessive sediment loading by road construction in the Hakusan National Park,central Japan

Synopsis Seasonal abundance and the re-establishment of stocks of iwana charr, Salvelinus leucomaenis f. pluvius were studied in the Jadani Stream, Hakusan National Park, central Japan, between 1984 and 1989 after the introduction of a moratorium on fishing. Stream conditions were severely damaged by dumped materials from the construction of a mountain road between 1967 and 1977. The densities of iwana increased markedly in the upper reaches and slightly in the middle reaches of the stream and showed marked seasonal fluctuations over the study period. Data shows that the iwana has a high potential reproductive capacity under degraded stream conditions. However, the population density of iwana remained low in the lower reaches, where the stream conditions were more severely damaged not only by construction of the mountain road but also abstraction of water for hydro-electric generation. We review also the state of native iwana and problems relating to its conservation in Japan.     

Effects of the Flooding Gradient on Tree Community Diversity in Várzea Forests of the Purus River,Central Amazon,Brazil

Amazonian floodplain forests have remarkable variation in tree diversity and structure related to flood duration. We assessed how floodplain forests respond to the continuum flooding gradient and found that Fisher's α values vary up to seven times across the landscape.     

海拔高度对江油地区杉木人工林群落结构和物种多样性的影响

物种多样性是群落功能复杂性和稳定性的重要量度指标,海拔高度是影响物种多样性的重要因素。该实验采用典型样地法,在800~900m(低海拔)和1 100~1 200m(高海拔)2个海拔高度分别取4个20m×20m的样地,对江油地区的杉木人工林群落结构和物种多样性进行研究,采用物种丰富度指数(D)、Shannon-Wienner多样性指数(H)、Simpson优势度指数(H′)和均匀度指数(Jsw)来综合衡量不同海拔杉木人工林群落的物种多样性。结果表明:(1)组成江油杉木人工林的物种共计205种,分属66科177属;低海拔地区乔木7种,灌木54种,草本47种;高海拔地区乔木10种,灌木60种,草本41种。(2)低海拔和高海拔的木本植物组成无明显差异,草本层的物种组成有明显差异。(3)群落各层次的物种多样性指数在低海拔和高海拔都表现为:灌木层草本层乔木层,乔木层的各项指数最低;物种多样性指数随海拔升高在特定区间内表现出一定规律性,D、H和Jsw值总体上呈高海拔低海拔,H′则相反,表明高海拔杉木人工林物种多样性和物种在群落中分布的均匀度都有增加的趋势,这与高海拔受人为干扰较轻以及环境因子的变化等密切相关。