Using 137Cs technique to quantify soil conservation capacities of different ecosystems in Wolong Natural Reserve, southwestern China

Reliable information about soil conservation capacities of different natural ecosystems is an important reference for the design of targeted erosion and sediment control strategies. The objective of this paper is to quantify the soil conservation capacities of different natural ecosystems that can represent different climatic zones. The 137Cs technique has been used to estimate soil redistribution rates in different natural ecosystems over the past 40 years in Wolong Nature Reserve. The reserve, transiting from the Chengdu plain to the Qinghai-Tibet plateau, maintains rich ecosystems from subtropical to frigid.The net soil erosion rates of 5 selected ecosystems that represent a warm coniferous-broadleaf-mixed forest, a cold-resistant deciduous taiga forest, a cold-resistant shrub, an evergreen cold-resistant taiga servation capacities are reversed in order. The reference inventories for 137Cs in different ecosystems velop effective erosion and sediment strategies in areas with similar climates should consider natural ecosystem types.     

Solid cultures of thrips-pathogenic fungi Isaria javanica strains for enhanced conidial productivity and thermotolerance

Entomopathogenic fungi have great potential to control agricultural and horticultural insect pests, however optimizing conidial production systems to demonstrate high productivity and stability still needs additional efforts for successful field application and industrialization. Although many virulent entomopathogenic fungal isolates have been viewed as potential candidates in a laboratory environment, very few of the isolates are being used in practice for application in agricultural fields as commercial products. I. javanicus is an entomopathogenic fungus that is parasitic to various diverse coleopteran and lepidopteran insects and thought good candidate as biopesticdes. In this work, the basic characteristics of two entomopathogenic fungi, I. javanica FG340 and Pf04, were investigated in morphological examinations, genetic identification, and virulence against Thrips palmi, and then the feasibility of various grains substrates for conidial production was assessed, particularly focusing on conidial productivity and thermotolerance. Isaria javanica FG340 and Pf04 conidia were solid-cultured on 12 grains for 14?days in a Petri dish. Of the tested Italian millet, perilla seed, millet and barley-based cultures showed high conidial production. The four-grain media yielded >1?×?10⁹ conidia/g of I. javanica FG340 and Pf04. Pf04 strain had enhanced thermotolerance up to 45?°C when cultured on Italian millet. In application, it was easy to make a conidial suspension using the cultured grains, and several surfactants were tested to release the conidia. This work suggests several possible inexpensive grain substrates by which to promote conidial production combined with enhanced stability against exposure to high temperature.     

Role of the Nuclease Activities Encoded by Herpes Simplex Virus 1 UL12 in Viral Replication and Neurovirulence

Enzyme-dead mutations in the herpes simplex virus 1 UL12 gene that abolished its endo- and exonuclease activities only slightly reduced viral replication in cell cultures. However, the UL12 null mutation significantly reduced viral replication, suggesting that a UL12 function(s) unrelated to its nuclease activities played a major role in viral replication. In contrast, the enzyme-dead mutations significantly reduced viral neurovirulence in mice, suggesting that UL12 nuclease activities were critical for viral pathogenesis in vivo.     

Aromatic amino acid transaminase in rat intestine

The transamination of aromatic l-amino acids (5-hydroxytryptophan, tryptophan, tyrosine, phenylalanine and kynurenine) was shown to be catalysed by enzyme preparations from rat small intestine. On the basis of the partial purification and characterization of these aromatic amino acid transaminases, it is suggested that rat small intestine contains several kinds of aromatic amino acid transaminases.     

5种光合细菌种间原生质体融合及优良农用融合子的筛选鉴定

处于对数生长期的光合细菌球形红假单胞菌(Rhodopseudomonassphaeroides)、沼泽红假单胞菌(Rhodopseudomonaspalustris)、嗜酸红假单胞菌(Rhodopseudomdnasacidophila)、深红红螺菌(Rhodospirarubrum)、万尼氏红微菌(Rhodomocrobiumvannielii),经溶菌酶(3mg/L)处理50min后,获得了它们的菌体形成的原生质体,其再生率分别为80%、71%、82%、61%、74%.取等量的亲本菌株在35%的PEG(MW6000)诱导下两两融合5min,共10种组合.其融合率为球×沼2.5×10-4、球×嗜2.1×10-4、球×深2.0×10-4、球×万2.1×10-4、沼×嗜2.8×10-4、沼×深2.4×10-4、沼×万2.6×10-4、嗜×深2.0×10-4、嗜×万2.3×10-4、深×万2.4×10-4.经影印法鉴定:形成的融合子可以分别生长于以相应的有机物为唯一碳源的培养基上,所有融合子体积均相当于两亲本株体积之和,融合子菌落形态特征介于两亲本株之间.从中随机挑选100个融合子,以辣椒苗作为靶标植物,从上述融合子中筛选到了1株具有显著促进作物生长、提高抗病性的融合子.     

Selenite and ebselen supplementation attenuates <Emphasis Type="SmallCaps">d</Emphasis>-galactose-induced oxidative stress and increases expression of SELR and SEP15 in rat lens

Selenite and ebselen supplementation has been shown to possess anti-cataract potential in some experimental animal models of cataract, however, the underlying mechanisms remain unclear. The present study was designed to evaluate the anti-cataract effects and the underlying mechanisms of selenite and ebselen supplementation on galactose induced cataract in rats, a common animal model of sugar cataract. Transmission electron microscopy images of lens fiber cells (LFC) and lens epithelial cells (LEC) were observed in d-galactose-induced experimental cataractous rats treated with or without selenite and ebselen, also redox homeostasis and expression of proteins such as selenoprotein R (SELR), 15kD selenoprotein (SEP15), superoxide dismutase 1 (SOD1), catalase (CAT), β-crystallin protein, aldose reductase (AR) and glucose-regulated protein 78 (GRP78) were estimated in the lenses. The results showed that d-galactose injection injured rat lens and resulted in cataract formation; however, selenite and ebselen supplementation markedly alleviated ultrastructural injury of LFC and LEC. Moreover, selenite and ebselen supplementation could mitigate the oxidative damage in rat lens and increase the protein expressions of SELR, SEP15, SOD1, CAT and β-crystallin, as well as decrease the protein expressions of AR and GRP78. Taken together, these findings for the first time reveal the anti-cataract potential of selenite and ebselen in galactosemic cataract, and provide important new insights into the anti-cataract mechanisms of selenite and ebselen in sugar cataract.     

Mechanism of interaction between electromagnetic fields and living organisms

Based on nonlinear phenomena of biophoton emission observed in the past, an interference model concerning with the mechanism of interaction between living organisms and electromagnetic fields was raised. Caused by biological nonlinearly polarizable double layer, destructive interference of incoming and reflected waves establishes in the outside. As a consequence, in the inside constructive interference takes place at the same time. The interference patterns may play an important role in biological self organization and in biological functions. We investigate the boundary conditions necessary for explaining these non-linear optical effects in terms of the phase conjugation. It turns out that there are solutions of the Maxwell equations which satisfy destructive interference of biophotons in agreement with the experimental results. Necessary provisions are nonlinearly polarizable optically active double layers of distances which are small compared to the wavelength of light. In addition, they have to be able to move into the nodal planes of the impinging waves within a small time interval compared to the coherence time. These conditions are likely fulfilled in the optically dense, but ordered and optically excited, highly polarizable living matter.     

Molecular phylogeny of the entomopathogenic fungi of the genus Cordyceps (Ascomycota:Clavicipitaceae) and its evolutionary implications

Cordyceps is an endoparasite ascomycetous genus containing approximately 450 species with a diversity of insect hosts,traditionally included in the family Clavicipitaceae of Ascomycota.Establishing the relationships among species with a varied range of morphologies and hosts is of importance to our understanding of the phylogeny and co-evolution of parasites and hosts in entomopathogenic ascomycetes.To this end,we used a combination of molecular index and morphological characters from 40 representative species to carry out comprehensive molecular phylogenetic analyses.Based on the phylogenetic tree,we used the program DISCRETE for inferring the rates of evolution and finding ancestral states of morphological character.The phylogenetic analyses revealed two important points.(i) Types of perithecia attached to stroma reflected an evolutionary trend in Cordyceps.The vertically immersed perithecia form was the ancestral state,superficial and obliquely immersed perithecia were derived characters,obliquely immersed was irreversible.Species with obliquely immersed perithecia were in a closely related group and were the derived group.(ii) A strong correlation between fungal relatedness and the microhabitat supported the hypothesis that the host jumps through commingling in soil microhabitats.Based on the results of these analyses,host switching explains the diversity of entomopathogenic fungi of the genus Cordyceps.     

siRNA制备技术的研究进展

近年来,siRNA(small interfering RNA)被广泛用于诱导哺乳动物体系中的RNA干扰。目前有五种siRNA制备方法：化学合成法、体外转录法、RNase Ⅲ家族体外消化法、表达载体法和表达框架法。在这些方法中siRNA序列的选择至关重要。随着药物研究和基因组研究的进展,siRNA的制备技术需要在高通量筛选、稳定性、基因导入和调控等方面进一步发展与完善。作者综述了siRNA序列的选择原则和哺乳动物系统中的siRNA产生方法,并简要讨论了其发展前景。