Chemical characteristics and potential source of fulvic acids leached from the plow layer of paddy soil

To understand better the chemical characteristics and source of dissolved organic matter (DOM) leached from the plow layer of rice paddies, a lysimeter study was conducted, which simulated submerged paddy topsoil during rice growth. The fulvic acid (FA) fraction in the percolation water from the lysimeter was collected by adsorption onto insoluble polyvinylpyrrolidone (PVP), and the temporal variations in its elemental composition, molecular size distribution, IR spectra, ¹³C CPMAS NMR spectra, and δ¹³C values were investigated. The proportion of the FA fraction to bulk DOM varied greatly, but the chemical characteristics of the FA fraction did not change appreciably during the experimental period. Thus, it is considered that the changes in the DOM composition in percolation water were mainly due to the differing contributions of the FA fraction. Further, to investigate the source of the FA fraction in the leachate, the chemical characteristics of the FA fraction in the leachate were compared with those extracted from the plow layer soil. A sequential extraction of the FA fraction was conducted using a sequence of water, 0.25 M Na₂SO₄, 0.1 M Na₄P₂O₇ (pH 7.0), 0.1 M Na₄P₂O₇ (pH 10.5), and NaBH₄+0.1 M Na₄P₂O₇ (pH 10.5). It was found that the water- and 0.25 M Na₂SO₄-extractable fractions, which were most mobile, were not the only source of the FA fraction in the leachate. The small molecular size sub-fraction of the NaBH₄+0.1 M Na₄P₂O₇ (pH 10.5)-extractable FAs, most of which are probably bound mainly to iron oxides, are considered to be another source of the FA fraction leached from the plow layer of paddy fields.     

93份叶用枸杞农艺性状分析及综合评价

为客观评价叶用枸杞种质资源多样性和筛选综合性状优异种质,初步筛选出综合性状优异的叶用枸杞新品种。以93份叶用枸杞种质8个农艺性状,利用变异系数、模糊数学隶属函数和聚类分析方法进行分析。变异系数分析显示变异系数范围为5.25%～73.52%,其中变异系数最大的为单株产量, 最小的为叶鲜干比,Shannon多样性指数范围为1.77～5.73,其中Shannon多样性指数最大的为地径,最小的为茎鲜干比;相关性分析显示单株产量与叶面积、叶鲜干比、株高和地茎显著正相关（P ≤0.05）,与叶形指数、茎鲜干比和叶/茎显著负相关（P ≤0.05）;隶属函数分析显示筛选出综合性状优异的叶用枸杞新品种9份,即Z88、Z76、Z100、Z58、Z32、Z54、Z57、Z85和Z69;聚类分析将种质分为五类,第Ⅰ类材料的特征为单株产量最高,株高、地径和叶面积等较大,包含品系Z88和Z76等,第Ⅱ类材料特征为地径最大,株高、叶形指数和叶面积等较大,包含品系Z58和Z32等,第Ⅲ类材料特征为叶面积最大,株高、叶鲜干比等较大,包含品系Z57和Z85等,第Ⅳ类材料特征为叶鲜干比最大,叶形指数和单株产量等较大,第Ⅴ类材料特征为叶/茎最大,叶形指数、茎鲜干比和株高等较大。93份通过杂交获得的叶用枸杞种质资源较为丰富,单株产量、地径、叶面积、叶鲜干比和叶/茎性状是作为评价叶用枸杞种质的重要农艺性状指标,模糊数学隶属函数和聚类分析方法能够准确、可靠地综合评价叶用枸杞种质资源。     

Chronic otitis externa with heat shock protein 70-positive intranuclear inclusion bodies in the ceruminous gland epithelium of a Chihuahua dog

A Chihuahua dog showed persistent itching in the right ear canal. Anti-inflammatory medicines and prednisolone were ineffective and total ear canal ablation was performed. Histological diagnosis was chronic otitis externa. Eosinophilic intranuclear inclusion bodies (Cowdry type A and full-type) were occasionally observed in the ceruminous gland epithelium. The inclusion bodies were negative for nucleic acid and ultrastructurally composed of fibrous structures (approximately 10 nm in width). Viral infection was initially suspected, but polymelase chain reaction tests did not detect the expected viral genes. Immunohistochemistry revealed that the inclusion bodies were positive for heat shock protein 70 (HSP70), suggesting that these bodies could be protein aggregates including HSP70. The etiology of this lesion has not been elucidated, but chronic inflammation may influence the cytoplasm-to-nuclear transportation of HSP70. To the best of our knowledge, this is the first report of canine chronic otitis externa with HSP70-positive intranuclear inclusion bodies.     

湖北神农架中蜂的数值分类研究

 通过测定湖北神农架6 个不同样点的18群东方蜜蜂，每群15只工蜂，每只蜜蜂样共38个形态特征，测定的性状特征的数据进行因素分析，集合分析和区辨分析；形态性状与生态环境因子相关性分析；并与周边省份东方蜜蜂的相关数据进行比较，发现: 神农架蜜蜂种群内遗传变异丰富，种群中许多形态性状特征表现出较明显的地理变异性；蜜蜂个体增大、体色变深, 具体是：前翅长、前翅宽、背板3，4宽； 后腿长、蜡镜长、蜡镜宽、蜡镜间距、腹片3，6的长和宽逐渐增加；而背板3，4的色素度、小盾片的色素度逐渐加深。神农架东方蜜蜂种群形态性状的多态性、多型性及其生态地理变异式样，均具有生态适应意义     

长白山东方蜜蜂形态特征研究*

 通过测定长白山6个不同样点17群东方蜜蜂的38个形态特征并采用计算机进行数据分析,得出长白山东方蜜蜂可分为3个类群。同邻近国家(日本、韩国)及中国部分地区的东方蜜蜂形态数据进行分析发现,长白山东方蜜蜂与日本、韩国的东方蜜蜂归于1个类群,由于长白山的气候及自然地理条件而形成多个小的生态区域,长白山东方蜜蜂在小区域内自成繁殖体系,各个生态区域间蜜蜂个体体色差异较大,体型大小差异不大。     

胡蜂与蜜蜂的防御行为研究

 在19.4℃气温条件下,选择东方蜜蜂和西方蜜蜂各3群进行蜜蜂激怒时的结团温度的试验研究,刺激物分别为半导体点温仪器的铜线头和活体胡蜂,在蜂群内放入刺激物后每隔15 s做一次温度记录。结果发现,在东方蜜蜂群内,蜂群对两种刺激物的结团蜜蜂数在25～32只之间;温度在210 s左右的时间内分别达到44.6 ℃和45.0 ℃,其中,刺激物为铜线头的结团温度最高可以达到45.0 ℃, 而刺激物为活体胡蜂的结团温度最高可以达到45.6 ℃;在西方蜜蜂群内,蜂群对两种刺激物的结团蜜蜂数在18～26只之间;蜂群对两种刺激物的结团温度在210 s左右的时间内分别达到42.2 ℃和 44.1 ℃,其中刺激物为铜线头的结团温度最高可以达到42.7 ℃,而刺激物为活体胡蜂的结团温度最高可以达到44.4 ℃.在恒温箱的耐温试验里,20 min内,黑盾胡蜂的最高耐温极限温度为46 ℃,而东方蜜蜂和西方蜜蜂的最高耐温极限温度却分别为51 ℃和52 ℃.另外, 选择云南高原温带型东方蜜蜂和云南低海拔热带型东方蜜蜂各2群,在蜂箱门口用活体黑盾胡蜂（Vespa velutina）干扰蜜蜂采集活动,干扰的时间分别为3 min,6 min和12 min. 每 min为一计数单位,记录蜜蜂采集蜂飞出的数量。结果发现:蜜蜂采集蜂飞出的数量随干扰时间的增加而明显下降,干扰的时间越长,蜜蜂采集蜂恢复到正常数量的时间就越长;高原温带型东方蜜蜂和低海拔热带型东方蜜蜂在胡蜂干扰时的在数量变化有着明显的差异,后者对胡蜂的干扰比前者更为敏感(P<0.05）。     

枸杞光合特性评价及高光效指标筛选

通过对枸杞种质的光合特性进行综合评价,以期筛选出高光效种质,为枸杞品种选育提供参考依据。采用大田试验,连续2 a对76份枸杞种质材料的光合气体交换参数、叶片物理性状指标进行测定,利用主成分分析、层次分析法、聚类分析法对枸杞种质的光合特性进行综合评价,筛选出合理的高光效评价指标。结果表明：枸杞种质间净光合速率、气孔导度、胞间CO₂浓度、蒸腾速率、水分利用率、叶面积、叶鲜质量、叶干质量均存在极显著差异,其中气孔导度、叶鲜质量、叶干质量、比叶重、叶面积的变异系数大,为46.3%~57.6%,胞间CO₂浓度、水分利用率的变异系数小,在10.9%～27.4%。利用主成分分析,提取到3个主成分,累计贡献率达86.88%,具有代表性,筛选出净光合速率、气孔导度、胞间CO₂浓度、蒸腾速率、叶面积、叶鲜质量、比叶重作为评价指标,通过层次分析法得出权重值依次为蒸腾速率＞比叶重＞叶鲜质量＞气孔导度＞叶面积＞净光合速率＞胞间CO₂浓度。通过聚类分析将76份材料划分为3种类型,低光效型6个,中等光效型51个,高光效型19个。利用判别分析对聚类结果重新进行分类,只有1个材料被误判,总误判率为1.32%,判对的概率为98.68%,分类结果可靠,可为后续新品种选育提供材料。     

The flammability of shrubs and trees in anAcacia mangium plantation based on silica-free ash content

Preliminary research to understand the flammability of 14 species of shrubs and 8 species of trees based on silica-free ash content was done in order to recognize which shrubs or trees are more flammable. The results show that the silica-free ash content of shrubs and trees leaves was greater than the stems ranging between 1.7% and 11.4% for leaf and 0.4% and 7.8% for the stems. The shrubsDicranopteris linearis, Imperata cylindrica, Eupatorium pubescens, Lantana camara, Eugenia sp.,Cliforia laurifolia, Pterospermum sp.,Hibiscus similis, Clidemia hirta andTrema orientalis must be considered when fire invades the plantation as well as the treeParaserianthes falcataria, Eucalyptus urophylla, Calliandra callothyrsus, andPeronema canescens.     

The changes in proximate compositions and glycogen contents in the dorsal ordinary muscles of the full-cycle cultured Pacific bluefin tuna Thunnus orientalis occurring with growth

ABSTRACT:   Using full-cycle cultured (FC) Pacific bluefin tuna (body length [BL], 42.6–66.4 cm; body weight [BW], 1.66–7.40 kg, n  = 15), the changes in chemical compositions and histological structure of the cephalal parts of the dorsal ordinary muscles (DOM) occurring with growth were investigated. A positive correlation ( r  = 0.9644, P  < 0.05) was observed between BL and BW with growth. The protein, lipid and ash contents of DOM and condition factor did not change with growth. However, the glycogen content of DOM increased ( P  < 0.05) from approximately 55 cm (BL) in this study. Using optical microscopic photographs, the various shapes of muscle fibers were observed and it was noted that the muscle fiber diameter increased ( P  < 0.05) with growth. Using transmission electron microscopic observation, many glycogen granules were observed in muscle fibers (especially, side of connective tissue) of DOM throughout the growth stage in this study. These results indicate that the glycogen content of DOM of FC Pacific bluefin tuna increases before the lipid with growth.     

Guanine-cytosine contents of the host and symbiont cDNA in a symbiotic coral

ABSTRACT:   Hermatypic (reef-building) corals harbor dinoflagellate endo-symbionts Symbiodinium spp. In studying gene expression in such symbiotic corals, problems arise regarding how to distinguish the coral and symbiont mRNA, and how to estimate their fractions in the mRNA population of the holobiont (symbiotic complex of the coral and Symbiodinium cells). In this study, these issues were addressed using juveniles of hermatypic coral Acropora tenuis in symbiosis with Symbiodinium cells of strain PL-TS-1. First, the guanine-cytosine (GC) contents were determined in expressed sequence tags (EST) from PL-TS-1 cells cultured in vitro and symbiont-free larvae of A. tenuis , and their average GC contents were found to be significantly different. The average GC content of the EST from the holobiont was much closer to that of A. tenuis larvae, suggesting that the majority (>90%) of mRNA isolated from the holobiont originated in the host. In protein-coding sequences, little overlap was observed between the GC-content distributions of PL-TS-1 cells and A. tenuis larvae. All of the coding sequences ( n  = 59) found in the A. tenuis EST had GC contents below 0.5, whereas the GC content exceeded 0.5 in the majority (43/44) of coding sequences from the nuclear genome of PL-TS-1 cells.