马传贫驴白细胞弱毒疫苗株跨膜蛋白主要免疫决定区基因的克隆与表达

从感染驴白细胞的马传贫驴白细胞弱毒疫苗株前病毒DNA中克隆了编码跨膜蛋白主要免疫决定区(TMIR)的基因，并在大肠杆菌中进行了表达。所表达的融合蛋白有一部分是可溶的，其氨基端带有6个组氨酸的标签，因此可以用固定化金属离子亲和层析法在非变性条件下进行纯化。在间接酶联免疫吸附试验(ELISA)和免疫印迹试验中，重组的TMIR蛋白可与马传贫阳性血清样品发生反应，而与健康马血清无任何反应。这表明该重组蛋白具有良好的抗原性和特异性，可用于马传贫弱毒疫苗株在体内外复制、接种马体内免疫应答及马传贫诊断的研究。     

红壤丘陵果农复合系统的小气候效应初步观察

果农复合系统是江西丘陵红壤开发的主要模式。试验表明,果农复合系统能增加空气湿度,调节温度,稳定土壤水热状况,对改善小气候具有一定的作用,从而为改善整个小流域的气候环境创造了条件,是一种值得推广的耕作模式。     

贵州典型黄壤辣椒生长、品质及光合特性对新型肥料的响应

为探究新型肥料在贵州黄壤区辣椒上的施用效果,本研究通过盆栽试验研究了普通复合肥(FHF)、保水型(BSX)、稳定性(WDX)、包膜型(BMX)缓释肥和长效氮肥(CXDF)五种新型肥料施用对贵州辣椒生长、品质及光合特性的影响,并通过相关分析明确影响辣椒产量的主导因素,以期为适宜的新型肥料品种筛选及其在辣椒种植中的推广应用提供参考依据。结果表明∶与普通复合肥(FHF)相比,施用新型肥料使辣椒株高增加0.72%~3.76%,但对辣椒茎粗影响不大。新型肥料显著提高辣椒分蘖数和产量,分蘖数和单株产量较FHF处理分别增加2.65%~19.75%和12.26%~29.77%,稳定性缓释肥(WDX)产量最高,达到300.35 g·株~(-1)。不同类型新型肥料对辣椒品质影响存在差异,与普通复合肥(FHF)相比,保水型缓释肥(BMX)可使辣椒硝酸盐含量显著降低23.93%、还原糖增加10.65%、Vc增加38.61%,长效氮肥(CXDF)处理的硝酸盐含量显著降低12.64%,稳定性缓释肥(WDX)处理的Vc含量显著增加56.21%,而包膜型缓释肥(BMX)和长效氮肥(CXDF)处理的Vc含量则明显著降低。相关分析结果表明,辣椒株高、分蘖数以及净光合速率(Pn)、胞间CO2浓度(Ci)和蒸腾速率(Tr)均与辣椒产量存在显著或极显著的线性相关,而综合考虑多个影响因子并利用逐步回归分析进行拟合后得到逐步回归分方程为Y=52.316X7-1.714X_6+640.888(X_6为胞间CO_2浓度(Ci)、X_7为蒸腾速率(Tr),相关系数r为0.924**),说明收获期辣椒叶片的胞间CO_2浓度(Ci)与蒸腾速率(Tr)对辣椒产量的影响起到了主导作用。综上所述,新型肥料对贵州典型黄壤上辣椒生长、品质以及光合特性的影响效果是显著的,综合来看以稳定性(WDX)和包膜型(BMX)缓释型的施用效果最优。     

护坦与丁坝在林区沿河公路防护中的应用

研究分析了丁坝和护坦在沿河林区公路路基防护中的作用、防护原理、设置方法、应用条件和有效性问题。     

淡水养殖池塘及其外河水中TOC·COD及PV的相关性分析

根据《渔业水域生态环境监测规范》(SC/T9102.3-2007),于2014年6~8月对湖州市43家水产养殖场的池塘水及其周边水体中TOC、COD及PV的含量进行测定,并分析了外河水及池塘水中PV与TOC、COD与TOC的相关关系。结果表明,池塘水中TOC、COD和PV的含量均高于其外河水,说明水产养殖自身存在较高的有机物污染。相关性分析表明,外河水中PV与TOC、COD与TOC相关性较高,相关系数分别为0.896和0.848(P0.01);池塘水中PV与TOC、COD与TOC相关性良好,但较外河水有所下降,相关系数分别为0.635和0.775(P0.01)。水产养殖水体中较高浓度的悬浮物、亚硝酸盐和氯离子等共存离子对不同有机物指标间的相关性影响较大,仅用单一测定参数预测水体中有机物污染情况局限性较大。因此,在分析养殖水体中有机物污染状况时,应根据不同水体的实际情况,选择一种适用于该水体有机物测定的参数或者将多种参数结合起来分析。     

Temporal changes in ascendance and in‐season exploitation of Atlantic salmon,Salmo salar,inferred by a video camera array

Abstract Weekly exploitation rates of Atlantic salmon, Salmo salar L., in the River Utsjoki, Finland, were estimated from catch reports during the 2003, 2004, 2006 and 2007 seasons, and recordings of all Atlantic salmon ascending the river using a submerged video camera array. In all years, mean weekly fishing mortality rates were significantly higher in June than July to August, with a falling trend throughout the fishing season. Owing to overlap in size between one‐sea‐winter (1SW) and multi‐sea‐winter (MSW) salmon, the estimated fishing mortality rates were based on all sea‐age categories combined. By the second week in June, 18.3–34.7% of large salmon (only MSW) had ascended, compared with 2.2–6.4% of small salmon (1SW and some MSW). Indirectly, the earlier start of ascent of large salmon to River Utsjoki indicated that in‐river fishing mortality of MSW salmon is higher than for 1SW salmon. A later opening of the fishing season may be used to reduce the in‐river fishing mortality, especially for the MSW component.     

Natural and artificially-induced habitat complexity and freshwater fish species composition

Abstract  The effects of habitat complexity, induced by construction of artificial reefs, on the fish assemblages in the Barra Bonita reservoir, Brazil, and in the lotic zone immediately below the dam were studied. Four artificial reefs were constructed in each habitat at variable distances from the shore. Multiple correspondence analysis showed that the factors distance from the shore and type of habitat were determinants for the group formation, and artificial reefs had a lesser effect. Fish species composition was about the same at locations with and without reefs.     

The Traditional Whedo Aquaculture System in Northern Benin

The traditional whedo system involves the digging of large ditch-like ponds that fill seasonally with flood water, trapping fish which are subsequently harvested during the dry season. Although whedos are well described in the South of Benin, basic information necessary for their management in the North is lacking. Since 1998, the commune of Malanville has experienced a kind of ‘blue revolution’ because up to now, approximately 500 whedos (known locally as tschifi dais) have been constructed covering a total surface area of 9.3 ha, thus reflecting the high acceptance of the practice among the local population. Despite the fast development this system has received little attention from national development planners and international agencies, but in view of the disastrous state of the river Niger's fishery, sustainable aquaculture, fully relying on local species should be supported to release pressure on natural fish stocks. Instead of focussing all efforts on the introduction of modern aquaculture, it is important to enhance the existing system because of the knowledge and acceptance by the local population.

This paper characterizes the current management and the technical as well as economical features of the tschifi dais in the commune of Malanville, northern Benin.     

嫩江上游地区水土流失现状及成因分析

对嫩江上游的大兴安岭及其周边地区的水土流失现状作了简要的分析,给出了近20年该地区的水土流失及产生水土流失的原因。针对这些原因提出了相应的防治措施和预测模型(USLE),并对其进行了简单的介绍。分析结果有利于改善当地的水土流失,促进地区的可持续发展。     

打破野生藏沙蒿种子休眠方法的筛选与评价

为筛选能够打破野生藏沙蒿（Artemisia wellbyi）种子休眠的适宜方法,本研究采用不同温度的温水浸种,不同浓度硝酸钾（KNO₃）、赤霉素（GA₃）、吲哚乙酸（IAA）、微量元素浸种以及不同浓度过氧化氢（H₂O₂）、聚乙二醇（PEG-6000）浸泡滤纸等7种方法处理藏沙蒿种子,测定种子萌发及活力指标,并利用隶属函数法将各指标进行综合评价。结果表明：随着KNO₃浓度的升高,藏沙蒿种子的相对发芽率呈现升高的趋势;且高浓度KNO₃对藏沙蒿种子根的伸长有较高促进作用;低浓度的GA₃,IAA,PEG-6000和30℃温水浸种对藏沙蒿种子萌发有促进效果;微量元素浸种对藏沙蒿种子的萌发影响较对照差异不显著;较高H₂O₂浓度下藏沙蒿发芽指数有所升高,但对其根长和芽长有一定抑制作用。综合分析,不同浓度GA₃,10 mg·L^-1IAA浸种处理12 h对藏沙蒿种子的萌发促进效果整体最优,可以作为打破藏沙蒿种子休眠的适宜方法。