不同气候对氧化型降解地膜的影响（英文）

【目的】通过在三个不同气候地区的试验,研究气候因素对农用氧化型降解地膜降解的影响,为此类降解地膜在不同地区的应用而调整添加剂配方提供指导。【方法】太阳辐射、温度和湿度是控制降解速度的主要因素,通过红外光谱分析,力学性能和分子量测试来评估他们对降解的影响。【结果】太阳辐射强度对氧化型降解地膜的降解影响最大。经过6个月太阳照射后,含有高浓度添加剂的降解膜,降解速率快。【结论】氧化型农用降解地膜的降解速率主要受太阳辐射强度控制,温度和湿度对降解速率影响较轻。当分子量小于5道尔顿时,降解膜碎片能够被微生物消化。     

A low molecular weight immunosuppressive factor produced by Onchocerca gibsoni

An immunosuppressive factor(s) which is heat stable, and dialysable, with a molecular weight less than 10,000 molecular weight, and is not species specific, has been shown to be produced during the in vitro culture of Onchocerca gibsoni microfilariae. The factor(s) is capable of abolishing lymphocyte mitogenesis induced by Con A in bovine lymphocytes and PHA in human lymphocytes. The factor(s) may play a role in establishing the microfilariae in the tissues of the host by depressing cell mediated immune reactions during invasion.     

Flip-flopping fractional flux quanta

The d-wave pairing symmetry in high-critical temperature superconductors makes it possible to realize superconducting rings with built-in pi phase shifts. Such rings have a twofold degenerate ground state that is characterized by the spontaneous generation of fractional magnetic flux quanta with either up or down polarity. We have incorporated pi phase-biased superconducting rings in a logic circuit, a flip-flop, in which the fractional flux polarity is controllably toggled by applying single flux quantum pulses at the input channel. The integration of p rings into conventional rapid single flux quantum logic as natural two-state devices should alleviate the need for bias current lines, improve device symmetry, and enhance the operation margins.     

热塑挤压操作参数对低值水产蛋白组织化制品物理特性的影响

以北太平洋鱿鱼加工废弃的边角料为原料,采用双螺杆挤压技术,利用响应面分析方法研究了主要操作参数物料含水量、机筒温度和螺杆转速对鱿鱼蛋白挤出物的水分含量和堆积密度的影响,分别建立挤出物水分含量、堆积密度与操作参数的回归拟合方程。结果表明,物料含水量对挤出物水分含量的影响非常明显,两者呈现正相关关系,物料含水量和机筒温度的交互作用对挤出物的水分含量和堆积密度的影响均呈显著性;水分含量、堆积密度与操作参数的回归拟合方程的相关系数R2分别是0.952和0.819,拟合的统计模型具有较高的可信度。     

Activating landscape ecology: a governance framework for design-in-science

Context

In response to predominantly local and private approaches to landscape change, landscape ecologists should critically assess the multiscalar influences on landscape design.

Objectives

This study develops a governance framework for Nassauer and Opdam’s “Design-in-Science” model. Its objective is to create an approach for examining hierarchical constraints on landscape design in order to investigate linkages among urban greening initiatives, patterns of landscape change, and the broader societal values driving those changes. It aims to provide an integrative and actionable approach for landscape sustainability science.

Methods

This framework is examined through an ethnographic study of public policy processes surrounding the urban tree initiatives in Boston, MA; Philadelphia, PA; and Baltimore, MD.

Results

These initiatives demonstrate the impact of political and economic decentralization on urban landscape patterns. Their collaborative governance approach incorporates diverse resources to implement programming at a fine-scale. The predominant tree giveaway program fragments the urban and regional forest.

Conclusion

Spatial and temporal fragmentation undermines the long-term security of urban greening programs, and it suggests reconsideration of the role of state regimes in driving broad scale spatial planning.

     

薯莨及红根皮单宁组分的研究(凝缩类单宁组分研究之四)

从薯莨(Dioscorea cirrhosa)块茎及红根(Rosa spp.)根皮提取物中分离出来的单宁,通过各种降解反应及波谱方法研究,均判定为原花青定。其中的终端单元及延伸单元,都由(+)-儿茶素及(-)-表儿茶素组成,但(-)-表儿茶素单元在薯莨原花青定中占大部分,(+)-儿茶素单元在红根原花青定中占大部分。     

Geraniin and amariin,ellagitannins from Phyllanthus amarus, protect liver cells against ethanol induced cytotoxicity

Ethanol mediated free radical generation plays an important role in the pathogenesis of liver injuries and alcoholic liver diseases. In the present study two ellagitannins namely geraniin and amariin isolated from Phyllanthus amarus were examined for their ability to protect mouse liver slices against ethanol induced toxicity and possible mechanism of its protection. Oxidative stress markers such as, lipid peroxidation, protein carbonyl formation, amount of 8-hydroxy-2-deoxyguanosine and antioxidant enzymes levels were measured using specific biochemical assays. Poly (ADP-ribose) polymerase (PARP), Bax and Bcl2 were checked to assess the induction of apoptosis using western blots. The results showed that geraniin and amariin protected mouse liver slices against ethanol induced cytotoxicity. Both compounds inhibited oxidation of lipid, protein and formation of 8-hydroxy-2-deoxyguanosine, all of which were found to be elevated on exposure to ethanol. These compounds restored the antioxidant enzymes altered on ethanol exposure. Compounds also inhibited the cleavage of PARP and bax and restored Bcl2, induced on exposure to ethanol. In summary, both ellagitannins effectively protected mouse liver slices against ethanol induced cytotoxicity and apoptosis by reducing oxidative damage to biological molecules and modulating Bax/Bcl-2 ratio respectively, thus minimizing liver injury.