Monitoring and management strategy for Helicoverpa armigera resistance to Bt cotton in China

The cotton bollworm, Helicoverpa armigera, is one of the most important insect pests in cotton growing regions of China. Transgenic cotton that expresses a gene derived from the bacterium Bacillus thuringiensis (Bt) has been deployed for combating cotton bollworm since 1997. Natural refugees derived from the mixed planting system consisting of cotton, corn, soybean, vegetables, peanut and others on single-family farms of a small scale were used for delaying the evolution of resistance to Bt cotton. Susceptibility of H. armigera field populations to the Bt insecticidal protein Cry1Ac was monitored from 1997 to 2006. The results indicate that the field populations are still susceptible to Cry1Ac, and monitoring indication no apparent shifts in susceptibility in field populations of this important pest.     

Conservation Reserve Program Benefits on Henslow's Sparrows Within the United States

ABSTRACT Henslow's sparrow (Ammodramus henslowii) is one of North America's fastest declining songbirds. Population declines combined with a small global population have led to heightened conservation concern. I used data from the North American Breeding Bird Survey to assess the impact that the Conservation Reserve Program (CRP) has had on Henslow's sparrows throughout their United States breeding range. My analysis suggests local Henslow's sparrow population trends are correlated with CRP enrollment, with populations increasing more in areas with relatively high local CRP enrollment, and that CRP appears to be playing a significant role in reversing long-term population declines.     

江苏宜兴龙池山现代植被表土孢粉的初步研究

江苏宜兴龙池山森林自然保护区表土花粉分析结果表明,表土孢粉植物群主要以栎属(Quercus)、松属(Pinus)、青冈属(Cyclobalanopsis)、栲属(Castanopsis)/柯属(Lithocarpus)、栗属(Castanea)占优势的木本植物组成,混生有枫香属(Liquidambar)、杨梅属(Myrica)、冬青属(Ilex)、女贞属(Ligustrum)、紫树属(Nyssa)、盐肤木属(Rhus)、黄连木属(Pistacia)等亚热带常见植物类型。研究区不同海拔高度的表土孢粉组合特征基本反映了当地现今的植物构成、植被面貌及其垂直分布规律。结合长江三角洲及其周边地区其他代表性表土花粉资料,首次提出以常绿阔叶木本植物与落叶阔叶木本植物含量之比(E/D),并结合重要优势、标志木本植物科属,初步识别和确立各地带性森林植被的表土花粉指标,为这一地区开展第四纪古植被和古气候等孢粉研究提供参考性依据。     

Resistance to glyphosate in the cyanobacterium <Emphasis Type="Italic">Microcystis aeruginosa</Emphasis> as result of pre-selective mutations

Adaptation of Microcystis aeruginosa (Cyanobacteria) to resist the herbicide glyphosate was analysed by using an experimental model. Growth of wild-type, glyphosate-sensitive (G^s) cells was inhibited when they were cultured with 120 ppm glyphosate, but after further incubation for several weeks, occasionally the growth of rare cells resistant (G^r) to the herbicide was found. A fluctuation analysis was carried out to distinguish between resistant cells arising from rare spontaneous mutations and resistant cells arising from other mechanisms of adaptation. Resistant cells arose by rare spontaneous mutations prior to the addition of glyphosate, with a rate ranging from 3.1 × 10⁻⁷ to 3.6 × 10⁻⁷ mutants per cell per generation in two strains of M. aeruginosa; the frequency of the G^r allele ranged from 6.14 × 10⁻⁴ to 6.54 × 10⁻⁴. The G^r mutants are slightly elliptical in outline, whereas the G^s cells are spherical. Since G^r mutants have a diminished growth rate, they may be maintained in uncontaminated waters as the result of a balance between new resistants arising from spontaneous mutation and resistants eliminated by natural selection. Thus, rare spontaneous pre-selective mutations may allow the survival of M. aeruginosa in glyphosate-polluted waters via G^r clone selection.     

Homochiral metal-organic coordination networks from l-typtophan

Three homochiral metal-organic coordination networks [Co₂(l-Trp)₂(Py)₆] · Py · (ClO₄)₂ (1), [Ni(l-Trp)(Py)₃] · H₂O · ClO₄ (2) and [Co₂(l-Trp)(INT)₂(H₂O)₂(ClO₄)] (3), all containing natural amino acid l-HTrp (l-typtophan), were hydrothermally synthesized and structurally characterized. The compounds 1 and 2 crystallize in the orthorhombic space group C222₁, with a = 10.731(2) Å, b = 19.709(4) Å, c = 27.365(6) Å and Z = 4 for 1 and a = 10.710(10) Å, b = 20.088(18) Å, c = 27.63(3) Å and Z = 8 for 2, respectively. The compound 3 has the monoclinic space group P2₁, with a = 8.1934(14) Å, b = 13.209(2) Å, c = 12.464(2) Å, β = 104.107(3)° and Z = 2. Both 1 and 2 consist of 1D helical chains. Compound 3 is composed of 2D networks, which further assemble into a 3D supramolecular structure via weak interlayer interactions. The optically pure amino acid l-HTrp plays an important role leading to homochiral structures reported here.     

Air movement preferences observed in office buildings

Office workers’ preferences for air movement have been extracted from a database of indoor environmental quality surveys performed in over 200 buildings. Dissatisfaction with the amount of air motion is very common, with too little air movement cited far more commonly than too much air movement. Workers were also surveyed in a detailed two-season study of a single naturally ventilated building. About one-half the building’s population wanted more air movement and only 4% wanted less. This same ratio applied when the air movement in workspaces was higher than 0.2 m/s, the de facto draft limit in the current ASHRAE and ISO thermal environment standards. Preference for “less air motion” exceeded that for “more” only at thermal sensations of −2 (cool) or colder. These results raise questions about the consequences of the ASHRAE and ISO standards’ restrictions on air movement, especially for neutral and warm conditions.     

广东鼎湖山自然保护区森林景观的动态模拟研究

在遥感和GIS系统支持下,以1991年和1999年两个时期的Landsat-TM合成影像为基础,利用马尔科夫模型,模拟鼎湖山自然保护区森林景观的动态演变。结果表明:常绿阔叶林面积增加,除水域外,其它面积相应减少,到达稳定期,区域内大多为常绿阔叶林,少量的混交林,其它类型几乎消失。这个趋势是和该地区森林的演替规律相符的,但是这种结果对维持保护区内的景观多样性是不利的。     

云南省小黑山自然保护区兰科植物多样性及保护评价

云南省小黑山自然保护区孕育了丰富的兰科植物。据调查,保护区有兰科植物43属、134种,约占云南省135属、780种的31.9%和17.2%,是保护区种子植物种类最多的科。兰科植物在保护区的各个生态类型中均有出现。保护区134种兰科植物以附生兰占优势,占67.16%(90种);其次,地生兰占31.34%(42种),腐生兰为1.50%(2种)。保护区兰科植物起源于新、旧世界的热带和温带,热带属占70.0%(28),温带属占27.5%(11)。鉴于兰科植物重要的保护价值,应加强保护区兰科植物的保护。首先应加强保护区的建设和管理,还应加强社区经济发展,加强科学研究,实施社区共管以及加大保护宣传力度。     

贵州柏箐喀斯特台原森林自然保护区两栖动物研究

在柏菁保护区共采到两栖动物标本267号,经整理鉴定隶属1目、6科、6属、13种。该区两栖动物垂直分布划为3个带：（1）海拔600．1000m为低山河谷农田两栖类带,本带两栖类6种,占总种数的46．15％;（2）海拔1000．1750m为中山台地农田针叶林两栖类带,有两栖类11种,占总种数的84．62％;（3）海拔1750～2200m为中山高原森林两栖类带,仅有1种。柏箐地区在动物地理区划上属于华中区,但两栖类以华中及华南区种为主。还讨论了中华蟾蜍和华西蟾蜍的分类地位。