Stream and wetland landscape patterns in watersheds with different cranberry agriculture histories,southern New Jersey,USA

Stream and wetland-landscape patterns in watersheds that drain active-cranberry bogs, abandoned-cranberry bogs, and forest land with no history of cranberry agriculture were compared at three different levels of detail. Stream-pattern variables included drainage density, sinuosity, and the number, density, and length of ditches. Landscape-pattern measures included wetland-patch structure (the size, shape, and number of wetland patches) and cover-type composition. The results of the stream-pattern analysis indicated that the effect of past and present cranberry agriculture on stream-drainage patterns was limited primarily to the occurrence of ditches. A greater number, density, median length, and total length of ditches were observed in cranberry and abandoned-bog basins compared to forest basins. Drainage density and sinuosity of the remaining non-ditched stream segments did not differ between basin types. Excluding areas of active-cranberry bogs where the native vegetation was removed, there was no significant difference in the relative number, size, shape, and composition of the remaining vegetation-cover types between the three basin types. The exact type and extent of vegetation removed to establish bogs in the active and abandoned basins are not known, but based on soil type and vegetation class associations, it was estimated that the largest losses were of pitch pine lowlands and cedar swamps.     

蛋白质组学及蛋白质翻译后修饰在畜牧领域中的应用研究进展

蛋白质组学是一门全方位研究生命结构功能、生理功能及生命活动规律的新兴学科,已成为后基因组时代研究的重要内容,在很多领域得到广泛关注,同时为畜牧科学的发展与创新提供了全新的研究思路和技术手段。目前,蛋白质组学在畜禽生长发育、繁殖、营养、疾病、肉质等方面均有涉及,并通过各种研究手段发掘出一批与畜禽重要经济性状相关的蛋白质,对生产有重要的理论指导意义。蛋白质翻译后修饰(post-translation modifications,PTMs)作为蛋白质组学研究的一个重要分支,在增加蛋白质多样性和进行复杂生理学调控过程中发挥着重要的作用,能更好地揭示生命现象的本质与规律。作者对蛋白质组学及PTMs在畜牧领域中的应用研究进展进行了综述。     

Glyoxalase 1 expression is downregulated in preimplantation blastocysts of diabetic rabbits

In a diabetic pregnancy, an altered maternal metabolism led to increased formation of reactive α‐dicarbonyls such as glyoxal (GO) and methylglyoxal (MGO) in the reproductive organs and embryos. The enzyme glyoxalase (GLO) 1 detoxifies reactive α‐dicarbonyls thus protecting cells against malfunction or modifications of proteins by advanced glycated end products (AGEs). The aim of this study was to analyse the influence of a maternal insulin‐dependent diabetes mellitus (IDD) on GLO1 expression and activity in preimplantation embryos in vivo and human trophoblast cells (Ac‐1M88) in vitro. Maternal diabetes was induced in female rabbits by alloxan before conception and maintained during the preimplantation period. GLO1 expression and activity were investigated in 6‐day‐old blastocysts from healthy and diabetic rabbits. Furthermore, blastocysts and human trophoblast cells were exposed in vitro to hyperglycaemia, GO and MGO and analysed for GLO1 expression and activity. During gastrulation, GLO1 was expressed in all compartments of the rabbit blastocyst. Maternal diabetes decreased embryonic GLO1 protein amount by approx. 30 per cent whereas the enzymatic activity remained unchanged, indicating that the specific GLO1 activity increases along with metabolic changes. In in vitro cultured embryos, neither hyperglycaemia nor MGO and GO had an effect on GLO1 protein amount. In human trophoblast cells, a stimulating effect on the GLO1 expression was shown in the highest GO concentration, only. Our data show that maternal diabetes mellitus affects the specific activity of GLO1, indicating that GLO1 was post‐translationally modified due to changes in metabolic processes in the preimplantation embryos.     

Differences in native soil ecology associated with invasion of the exotic annual chenopod,<Emphasis Type="Italic"> Halogeton glomeratus</Emphasis>

Various biotic and abiotic components of soil ecology differed significantly across an area where Halogeton glomeratus is invading a native winterfat, [ Krascheninnikovia (= Ceratoides) lanata] community. Nutrient levels were significantly different among the native, ecotone, and exotic-derived soils. NO₃, P, K, and Na all increased as the cover of halogeton increased. Only Ca was highest in the winterfat area. A principal components analysis, conducted separately for water-soluble and exchangeable cations, revealed clear separation between halogeton- and winterfat-derived soils. The diversity of soil bacteria was highest in the exotic, intermediate in the ecotone, and lowest in the native community. Although further studies are necessary, our results offer evidence that invasion by halogeton alters soil chemistry and soil ecology, possibly creating conditions that favor halogeton over native plants.     

甘蔗渣基离子吸附剂的研究

以甘蔗渣为原料,用丙烯腈和盐酸羟胺对其进行改性,在甘蔗渣分子中引入胺肟基团,提高其对金属离子的吸附能力.讨论了羟胺化反应条件如温度、时间、羟胺质量浓度对胺肟基团含量的影响.用红外光谱表征了产物的结构,用元素分析法测试了产物中氮元素的含量.在反应温度90℃、反应时间180min、羟胺质量浓度100g/L时,改性甘蔗渣中最大含氮元素为13.4%,最大含胺肟基团为3.38mmol/g,并对改性产物进行了铜离子的吸附研究,其最大铜离子吸附量为54.0mg/g.     

仿生合成的功能性纳米碳酸钙在造纸中的应用

采用仿生矿化原位合成淀粉改性纳米碳酸钙(MPCC),并将其应用于造纸技术当中.试验显示,使用该方法碳酸钙(PCC)可以被淀粉覆膜改性.填加原位生成的MPCC制备的手抄纸与填加PCC制备的手抄纸相比表面光滑度增大较多;在力学性能上,填加原位生成的MPCC的手抄纸普遍高于填加PCC制备的手抄纸;PCC的淀粉腹膜改性还可改善填料在手抄纸中的留着率,减少纸浆用量,降低生产成本.另外,仿生矿化原位合成功能性纳米碳酸钙技术在有机质改变碳酸钙表面性质的同时,还可以控制碳酸钙的晶体形貌和大小,这种技术可大大降低生产成本,增加造纸企业的经济效益.     

稻草纤维素醚化改性及其结构表征

以稻草纤维素为原料,对其进行醚化改性处理。通过单因素和旋转试验,确定了羧甲基纤维素制备的最佳条件为:醚化时间100min、醚化温度70℃、NaOH用量为3.2g以及一氯乙酸用量为3.0g,最大取代度为0.53。     

一种改良质粒DNA提取方法在实验课中的应用

改良碱裂解质粒DNA提取方法,将溶液Ⅰ、Ⅱ、Ⅲ、无水乙醇的反应时间分别缩短为0、0、10、0 min;用针式滤器除去残余蛋白质,替代了传统的酚/氯仿抽提方式,缩短DNA提取时间,使其在1 h内完成,并减少有毒物质对人体造成的伤害。获得的质粒DNA质量好、产率高,能满足常规分子生物学实验的要求。     

Comparison of the effect of Cow manure,Vermicompost, and Azolla on safflower growth in a saline-sodic soil

ABSTRACT

Soil salinity and sodicity are two important factors in land degradation, especially in arid and semi-arid regions of the world. Application of soil amendments, such as organic matter, can be a suitable method for improving the fertility of saline-sodic soils. In this research, a saline-sodic soil was chosen, mixed with three levels of 1%, 3%, and 5% (weight) of Cow manure, Vermicompost, and Azolla, and incubated for 5 months at field capacity and a temperature of 20°C. Then, safflower seeds were planted and treatments were placed in a greenhouse for two months. After this period, plant indices were measured. The results showed that the addition of treatments caused differences in safflower growth in comparison to the control treatment. The noted differences were mostly negative for the treatment of cow manure, they were negligible for Azolla, and were positive for Vermicompost. Vermicompost applied at 5% level provided the most suitable substrate for safflower growth in saline-sodic soil.     

沸石和方解石复合覆盖层控制底泥氮磷释放的效果及机理分析

通过模拟试验，研究了沸石和方解石复合覆盖层控制底泥氮磷释放的效果及机理。结果表明，（1）Ca^2＋会促进方解石对磷酸盐的去除，并且Ca^2＋浓度越高，对磷酸盐去除的促进作用越强，而Na＋则会抑制方解石对磷酸盐的去除。（2）采用CaCl2对天然沸石进行改性，可以提高沸石Ca^2＋的交换量和降低Na^＋的交换量；而采用NaCl改性则可以明显提高沸石Na^＋的交换量，并且大幅度地降低沸石Ca^2＋的交换量。（3）沸石与方解石复合覆盖层不仅可以控制底泥氨氮的释放，而且可以抑制底泥磷的释放，并且复合覆盖层对底泥磷释放的控制效果受沸石改性的影响，控制效果从大到小依次为CaCl：改性沸石〉天然沸石〉NaCl改性沸石。