三峡库区移民安置区生态农业发展模式的研究

就三峡库区农用土地的分布、开发方式、存在问题、生态农业发展模式等方面进行了初步的探讨．在分析三峡库区现已开发的农用土地存在着地力衰退、生产力低、自然灾害频繁及生态环境恶化等问题的基础上,从人与自然相协调的角度,提出了建立农林复合生态系统、木本粮油型、农林牧复合型、农林牧渔复合型的发展模式的思路和建议．     

近代人群头骨颞线的分型和变异

颞线作为头骨表面咀嚼肌颞肌的附着痕迹,其形态变异对探讨人类体质特征及咀嚼功能具有一定意义。为了解颞线在现代人群中的变异情况,本文选取亚洲、非洲和欧洲278例近现代成年人头骨为研究材料,通过对颞线的颞弧形态、宽度、发育程度、粗糙度及末端位置的观察和分析,明确颞线的分类及其定义标准,获取颞线各种表现形式的侧别、性别和地区间变异的数据,为体质人类学的研究提供参考资料。研究结果显示：1)颞线无显著侧别间差异;2)颞弧形态和发育程度无显著性别和地区间差异;3)顶部颞线宽度及粗糙度有显著性别间差异：男性顶部颞线整体较宽,粗糙型个体大多为男性;4)额部和顶部颞线宽度及粗糙度有显著地区间差异：超宽条带状颞线只出现在云南和华北地区标本,欧洲地区标本脊状颞线和粗糙型比例较高,非洲地区脊状颞线比例较高但粗糙型较低;5)颞线末端止于枕骨的类型极少;6)颞线宽度在额部和顶部及其与颞弧形态显著相关,颞线发育程度在额部与顶部显著相关。     

Retention of Sediments and Nutrients in the Iron Gate I Reservoir on the Danube River

This work addresses an intensively debated question in biogeochemical research: “Are large dams affecting global nutrient cycles?” It has been postulated that the largest impoundments on the Lower Danube River, the Iron Gates Reservoirs, act as a major sink for silica (Si) in the form of settling diatoms, for phosphorus (P) and to a lesser extent for nitrogen (N). This retention of P and N in the reservoir would represent a positive contribution to the nutrient reduction in the Danube River. Based on a 9-month monitoring scheme in 2001, we quantified the nutrient and the sediment retention capacity of the Iron Gate I Reservoir. The sediment accumulation corresponded to 5% TN (total nitrogen), 12% TP (total phosphorus) and 55% TSS (total suspended solids) of the incoming loading. A mass balance revealed that more N and P are leaving the reservoir than entering via the inflow. Based on these current results, the reservoir was temporarily acting as a small nutrient source. The nutrient accumulation in the sediments of the Iron Gate I Reservoir represents only 1% of the “missing” load of 10⁶ t N and 1.3 × 10⁵ t P defined as the difference between the estimated nutrient export from the Danube Basin and the measured flux entering the Black Sea. This result disproves the hypothesis that the largest impoundment on the Danube River, the Iron Gates Reservoir, plays a major role in N and P elimination.     

长江三峡库区蝶类群落的物种多样性

报道了多样性指数、丰富度和均匀度.各小生境物种丰富度的变化在0～28之间,其下限值的数理分布范围主要在0与5之间,而上限值的分布主要在9、11和12.物种多样性指数的变化范围是：样本间0～4.9285,小生境间0～2.1143,生境类型间0～1.7091和植被型0.9740～1.3143;而物种多样性指数最高的样本（4.9285）在1500～1500m针阔混交林的小生境中,物种多样性指数最高的小生境（2.1143）是1000～1500m阔叶林,物种多样性指数最高的生境类型是阔叶林灌丛（1.4373）,物种多样性指数最高的植被型是灌丛（1.3143）;而灌丛各生境类型的物种多样性指数最高,从1.2773到1.4373;草地居第二位1.0588～1.2402,森林最低,0.8088～0.9618（仅分布在一个海拔梯度的生境类型除外）;就整体有而言,物种多样性指数居前5位的生境类型都是灌丛.可见,三峡库区灌丛是最适宜于蝴蝶繁衍的植被型;完全成片的森林与纯粹的农田均不太适合蝴蝶生存.因环境的复杂性,物种多样性指数的最高值（4.9285）和最低值（0.0）均出现森林植被型,样本间物种多样性指数变异系数最大的也是森林植被型,表明它给蝴蝶生存的影响,也将是最复杂的.海拔高度对物种多样性指数的影响明显,最高的物种多样性指数出现在海拔1000～1500m（1.2363）,最低是2000m以上（0.2536）,但没有显著的规律性.灌丛和森林各个小生境的蝴蝶均匀度与物种多样性的变化趋势基本是一致的,表明这两种植被型内各小生境的物种多样性指数主要受物种均匀度变化的影响;农田和草地两种植被型的物种多样性指数的变化除受均匀度影响外,还较大程度地受物种丰富度的影响.在生境类型的水平上,蝴蝶均匀度与物种多样性指数、丰富度间有着比较复杂的关系.这些结果反映了三峡库区蝶类生存环境的多样性和破碎化,从而影响了蝴蝶分布的丰富度、多样性和均匀性.     

Identification and characterization of the TonB region and its role in transferrin-mediated iron acquisition in Haemophilus parasuis

Haemophilus parasuis is the causative agent of Gl?sser's disease, which is responsible for considerable economic losses in the pig-rearing industry. The aim of the study reported here was the identification, sequencing and molecular characterization of the TonB region that includes tonB, exbBD, and tbpBA genes in H. parasuis. In addition, two fusion proteins were generated. One of them (pGEX-6P-1-GST-TbpB) contained the first 501 amino acids of H. parasuis TbpB protein, while the second (pBAD-Thio-TbpB-V5-His) included the first 102 amino acids of H. parasuis TbpB N-terminus domain. A panel of 14 hybridomas secreting monoclonal antibodies was raised against the two recombinant TbpB fusion proteins. Furthermore, to assess whether the expression of the H. parasuis ExbB, TbpB, and TbpA proteins was upregulated under conditions of restricted availability of iron, a rabbit polyclonal antibody against H. parasuis TbpB-His fusion protein was produced. A rabbit polyclonal antibody against serotype 7 of Actinobacillus pleuropneumoniae ExbB and TbpA proteins was also used for the detection of the homologous proteins in H. parasuis. Overall, the data indicate that H. parasuis, like other members of the Pasteurellaceae family, possesses the genetic elements of the TonB region for iron acquisition and the transferrin-binding proteins encoded under this region are upregulated under restricted iron availability.     

横断山区高山姬鼠（Apdoemus chevrieri）头骨几何形态分析

研究对分布于横断山区（从北到南：巴塘、中甸、宁蒗、景东）的高山姬鼠头骨背面、腹面、侧面及下颌侧面的形态特征进行主成分分析、判别分析、薄片样条分析和多维尺度分析,以进一步探讨高山姬鼠头骨形态变异与环境之间的关系。研究结果表明,高山姬鼠头骨的背面和腹面在研究多种群头骨形态时更适宜,更有参考价值;经过薄片样条法分析显示形变集中在鼻骨、眼眶和臼齿,这可能与高山姬鼠生存的横断山从北到南的气候和地理环境变化相关;经多维尺度分析显示横断山地区的高山姬鼠的头骨发生了变异,这可能与高山姬鼠生活环境的经度和纬度有关。综上,横断山区的高山姬鼠种群的头骨形态有一定的变异,这可能反映了其对横断山不同生态环境的形态适应性变异．     

长江三峡库区及其邻近地区的残存稀有濒危植物群落

长江三峡库区及其邻近地区的残存稀有濒危植物群落属于中亚热带绿落叶阔叶混交林。群落所处自然环境少生境独特;群落中有数种至十余种稀有濒危植物群聚生长,且以其中的部分稀有濒危植物为优势种。独特的生增昨良好的群落结构被认为是该类群落得以保存的主要原因,应加强对该类群落的就地保护研究。     

Effects of solar radiation and solar radiation deprived of UV-B and total UV on photosynthetic oxygen production and pulse amplitude modulated fluorescence in the brown alga Padina pavonia

Abstract: The effects of solar radiation on photosynthetic oxygen production and pulse amplitude modulated (PAM) fluorescence were measured in the marine brown macroalga Padina pavonia harvested from different depths from the Greek coast near Korinth. In fluence rate-response curves the light compensation point for photosynthetic oxygen production increased and the saturation level decreased with increasing exposure time to solar radiation. Cutting off the UV-B wavelength range (280–315 nm) from solar radiation reduced the inhibition of photosynthesis, and the organisms were less affected when all of the UV radiation was filtered out. Algae collected from 7 m depth were much more prone to photoinhibition than those harvested from rock pools exposed to unfiltered solar radiation. During continuous exposure to solar radiation, rock pool algae showed photoinhibition after longer periods of time than specimens from 7 m or from dark adapted habitats. When subjected to unfiltered solar radiation the ratio of the variable fluorescence to the maximal fluorescence     (F_v = F_m− F_o) rapidly declined with increasing exposure time. However, again algae from 7 m depth were more prone to photoinhibition than rock pool algae. The differences between the two ecological strains were less obvious when UV-B or total UV was removed from solar radiation. Only in the latter case a complete recovery was observed after 2 h while, when exposed to unifiltered sunlight, only the rock pool algae recovered completely within that time.     

长江三峡库区蝶类群落的物种获得率、小生境占有率及相对多度

研究于 1998～ 2 0 0 3年在库区 10个区县 ,35个调查点进行。研究时 ,库区蝴蝶的生活环境被划分为 80个小生境 ,设置样带6 6 1条 ;调查期间获得 (Sampled)蝴蝶 331种 ,10 780只个体。报道三峡库区蝴蝶群落的部分参数 :2 5 3种蝴蝶的小生境占有率低于 10 % ,占有 4 0 %以上小生境的蝴蝶只有 7种 ;在 6 0条以上样带都获得的蝴蝶有 16种 ,而在 10条以下样带内获得的蝴蝶 2 19种 ,占总数的 6 6 .2 % ;优势种 2 1个 (6 .3% ) ,常见种 12 5个 (37.8% ) ,少见种 10 3个 (31.1% ) ,罕见种 82个 (2 4 .8% ) ;相对多度高于 1%的种类 2 2个 ,仅占总数的 6 .6 % ;个体数分布的规律接近对数级数法则。三峡库区蝶类现在的分布反映了库区生境破碎化的结果 ,意味着适宜的生境斑块周围分布不适宜生境 ,种群受到面积、隔离、边缘等多种效应的影响 ,形成了现有的物种多样性及其空间格局     

Iron levels in the human brain: A post-mortem study of anatomical region differences and age-related changes

The link between brain iron homeostasis and neurodegenerative disease has been the subject of extensive research. There is increasing evidence of iron accumulation during ageing, and altered iron levels in some specific brain regions in neurodegenerative disease patients have been reported.Using graphite furnace atomic absorption spectrometry after microwave-assisted acid digestion of the samples, iron levels were determined in 14 different areas of the human brain [frontal cortex, superior and middle temporal, caudate nucleus, putamen, globus pallidus, cingulated gyrus, hippocampus, inferior parietal lobule, visual cortex of the occipital lobe, midbrain, pons (locus coeruleus), medulla and cerebellum (dentate nucleus)] of n = 42 adult individuals (71 ± 12 years old, range: 53–101 years old) with no known history or evidence of neurodegenerative, neurological or psychiatric disorders.It was found that the iron distribution in the adult human brain is quite heterogeneous. The highest levels were found in the putamen (mean ± SD, range: 855 ± 295 μg/g, 304–1628 μg/g) and globus pallidus (739 ± 390 μg/g, 225–1870 μg/g), and the lowest levels were observed in the pons (98 ± 43 μg/g, 11–253 μg/g) and medulla (56 ± 25 μg/g, 13–115 μg/g).Globally, iron levels proved to be age-related. The positive correlation between iron levels and age was most significant in the basal ganglia (caudate nucleus, putamen and globus pallidus).Compared with the age-matched control group, altered iron levels were observed in specific brain areas of one Parkinson's disease patient (the basal ganglia) and two Alzheimer's disease patients (the hippocampus).     

The effect of the sagittal ridge angle on cartilage stress in the equine metacarpo-phalangeal (fetlock) joint

Fatigue failure of bones of the metacarpo-phalangeal (fetlock, MCP) joint is common in thoroughbred racehorses. Stresses within the fetlock joint cartilages are affected by the morphology of the third metacarpal bone (MC3) and proximal phalangeal bone, and the steepness of the median sagittal ridge of MC3 is believed to be associated with fracture. This study investigated the influence of the steepness of the sagittal ridge on cartilage stress distribution using a finite element model of the joint. Changes to the steepness of the sagittal ridge were made by applying a parabolic function to the mesh, creating four different models with sagittal ridge angles ranging from 95° to 105°. In the fetlock joint of Thoroughbred racehorses, sagittal ridge angles of >100° were associated with higher Von Mises stresses in cartilage at the palmar aspect of the condylar groove than such stresses in joints with sagittal ridge angles of <100°. Stresses were high in the specific region where fractures are known to originate in MC3. This aspect of morphology of the fetlock joint thus appears to play an important role in the magnitude and distribution of cartilage stresses, which, when acting on the underlying hard tissues of the articular calcified cartilage and subchondral bone may play a role in the initiation of fatigue fracture in the third metacarpal bone.     

香溪河库湾春季水华期间硝酸盐、磷酸盐的时空分布

在三峡水库香溪河库湾春季水华连续暴发期间(2005年2月26日—4月28日)对香溪河与长江汇合处(河口)至香溪河库湾上游库尾处总计14个采样点进行连续监测,结果表明硝酸盐和磷酸盐在库湾中存在明显的时空分布规律。在空间上,河口的硝酸盐浓度高,库尾浓度低,其变化趋势是随着与河口距离的增加而降低;磷酸盐的分布规律是库尾的浓度高,河口的浓度低,其变化趋势与硝酸盐恰好相反。各采样点硝酸盐和磷酸盐浓度在时间上也呈现出明显的规律。河口硝酸盐的浓度在不同时间变化幅度较小,库尾采样点的硝酸盐浓度的变化幅度较大,随着与河口距离的增加硝酸盐浓度在不同时间的变化幅度逐渐增大。各样点磷酸盐在时间上的变化趋势是样点S04-S08的变化幅度较大,位于香溪河库湾河口和库尾的变化幅度较小。     

气候变化背景下青海省三江源地区游憩功能格局演变

在气候变化背景下,青海三江源地区游憩功能格局发生改变。综合运用PC （Pairwise Comparison）法、AHP （Analytic Hierarchy Process）、指标模型、相关分析等方法,构建三江源地区游憩功能评价框架,研究1978-2012年三江源地区3类游憩功能格局的演变,以及这种演变与气候变化之间的关联。研究表明：（1）气候条件、独特景观、植被条件、地表覆被与地形条件等要素影响着三江源地区游憩功能的形成,不同要素在美感、参与机会与适宜环境3类游憩功能形成过程中发挥的作用不同,且具有非线性贡献;（2）三江源地区的美感功能较强,其次是参与机会功能,而适宜环境功能较弱;（3）气候变化在不同程度上改变了三江源地区的3类游憩功能,其中,适宜环境功能的响应最强烈,主要表现为提升;参与机会功能的响应程度最弱。该研究完善了游憩功能的理论与应用,并为气候变化背景下三江源地区旅游可持续发展决策提供参考。     

Analysis of spatial and temporal patterns of aboveground net primary productivity in the Eurasian steppe region from 1982 to 2013

To explore the importance of the Eurasian steppe region (EASR) in global carbon cycling, we analyzed the spatiotemporal dynamics of the aboveground net primary productivity (ANPP) of the entire EASR from 1982 to 2013. The ANPP in the EASR was estimated from the Integrated ANPP_NDVI model, which is an empirical model developed based on field‐observed ANPP and long‐term normalized difference vegetation index (NDVI) data. The optimal composite period of NDVI data was identified by considering spatial heterogeneities across the study area in the Integrated ANPP_NDVI model. EASR's ANPP had apparent zonal patterns along hydrothermal gradients, and the mean annual value was 43.78 g C m^?2 yr^?1, which was lower than the global grasslands average. Compared to other important natural grasslands, EASR's ANPP was lower than the North American, South American, and African grasslands. The total aboveground net primary productivity (TANPP) was found to be 378.97 Tg C yr^?1, which accounted for 8.18%–36.03% of the TANPP for all grasslands. In addition, EASR's TANPP was higher than that of the grasslands in North America, South America, and Africa. The EASR's TANPP increased in a fluctuating manner throughout the entire period of 1982–2013. The increasing trend was greater than that for North American and South American and was lower than that for African grasslands over the same period. The years 1995 and 2007 were two turning points at which trends in EASR's TANPP significantly changed. Our analysis demonstrated that the EASR has been playing a substantial and progressively more important role in global carbon sequestration. In addition, in the development of empirical NDVI‐based ANPP models, the early–middle growing season averaged NDVI, the middle–late growing season averaged NDVI and the annual maximum NDVI are recommended for use for semi‐humid regions, semi‐arid regions, and desert vegetation in semi‐arid regions, respectively.     

垄作栽培对高产田夏玉米光合特性及产量的影响

试验于2006-2007年在河南省浚县农业科学研究所试验田进行,以传统平作为对照,研究了垄作栽培对夏玉米光合特性和产量的影响.结果表明,垄作提高了夏玉米光合速率Pn、叶片蒸腾速率Tr和气孔导度Gs,且其日变化均呈单峰曲线,12:00达到最大值,而细胞间隙二氧化碳浓度Gi有所降低,其日变化与Pn相反,呈倒抛物线型.垄作栽培夏玉米的最大光化学效率Fv/Fm和实际光化学效率φPSⅡ均有所增加.与平作相比,垄作后期叶面积衰减较慢,籽粒蜡熟期和成熟期垄作比平作叶面积指数分别高6.4％和3.7％,减少了漏光损失,垄作栽培延长了叶片功能期,促进光合产物的积累及向籽粒的转移,有利于后期玉米籽粒充实,千粒重显著高于平作,产量提高9.6％.