Shrinkage and swelling behavior of archaeological waterlogged wood preserved with slightly crosslinked sodium polyacrylate

In this article, the conservation of archaeological waterlogged wood (WW) of Afzelia sp. (medium degraded: U_max = 385%) was impregnated in vacuum with an aqueous solution of acrylic acid (AA), sodium acrylate monomer (AANa), crosslinking agent (MBA) and catalyst (V-501). The simultaneous in situ polymerization and crosslinking resulted in slightly crosslinked sodium polyacrylate (PAANa) in the wood structure. The results showed that untreated WW had only a very limited ability to re-swell to recover its original dimensions from a collapsed condition, while WW protected by crosslinked PAANa could almost fully recover its original shape and size even after several drying–rewetting cycles. From microscopic observations, treated wood was found to maintain its original cell structure, form and shape even after repeated drying–rewetting cycles. PAANa was observed to be densely localized near the middle lamella, the cell corners, and the cell lumina by transmission electron microscopy observation. These observations suggest that our PAANa treatment provides reasonable strength as well as favorable hydrophilicity to avoid hornification of the cell wall upon drying, thus providing unique shape recovery properties.     

Within-stem variations in mechanical properties of <Emphasis Type="Italic">Melia azedarach</Emphasis> planted in northern Vietnam

Within-stem variations in the mechanical properties of 17–19-year-old Melia azedarach planted in two sites in northern Vietnam were examined by destructive and nondestructive methods. Wood samples were collected from 10, 50, and 90% of the radial length from pith on both sides (North and South) at 0.3, 1.3, 3.3, 5.3, and 7.3 m heights above the ground. The mean values in whole trees of wood density (WD), modulus of rupture (MOR), modulus of elasticity (MOE), and dynamic modulus of elasticity (E_d) at 12% moisture content were 0.51 g/cm³, 78.58 MPa, 9.26 GPa, and 10.93 GPa, respectively. Within the stem, the radial position was a highly (p?<?0.001) significant source of variation in mechanical properties. MOR, MOE, and E_d increased from pith to bark. WD had a strong positive linear relationship with both MOR (r?=?0.85, p?<?0.001) and MOE (r?=?0.73, p?<?0.001). This suggests that it is potentially possible to improve mechanical properties through controlling WD. MOR had also a strong linear relationship with E_d (r?=?0.84, p?<?0.001). This indicates that E_d is a good indicator to predicting the strength of wood if the density of measured element is known. Besides, the stress wave method used in this study provides relatively accurate information for determining the stiffness of Melia azedarach planted in northern Vietnam.     

Successful drug development despite adverse preclinical findings part 1: processes to address issues and most important findings

Unexpected adverse preclinical findings (APFs) are not infrequently encountered during drug development. Such APFs can be functional disturbances such as QT prolongation, morphological toxicity or carcinogenicity. The latter is of particular concern in conjunction with equivocal genotoxicity results. The toxicologic pathologist plays an important role in recognizing these effects, in helping to characterize them, to evaluate their risk for man, and in proposing measures to mitigate the risk particularly in early clinical trials. A careful scientific evaluation is crucial while termination of the development of a potentially useful drug must be avoided. This first part of the review discusses processes to address unexpected APFs and provides an overview over typical APFs in particular classes of drugs. If the mode of action (MoA) by which a drug candidate produces an APF is known, this supports evaluation of its relevance for humans. Tailor-made mechanistic studies, when needed, must be planned carefully to test one or several hypotheses regarding the potential MoA and to provide further data for risk evaluation. Safety considerations are based on exposure at no-observed-adverse-effect levels (NOAEL) of the most sensitive and relevant animal species and guide dose escalation in clinical trials. The availability of early markers of toxicity for monitoring of humans adds further safety to clinical studies. Risk evaluation is concluded by a weight of evidence analysis (WoE) with an array of parameters including drug use, medical need and alternatives on the market. In the second part of this review relevant examples of APFs will be discussed in more detail.     

Anthracnose of Madagascar periwinkle caused by species belonging to the Colletotrichum gloeosporioides species complex

Severe blight of stems was found on Madagascar periwinkle (Catharanthus roseus) in Shizuoka and Okinawa prefectures, Japan, in July 2003 and September 2004, respectively. Similar fungi were isolated from the diseased plants. The isolated fungi caused the disease after inoculation and subsequently were reisolated from diseased tissues. The fungi were identified as species closely related to C. siamense or C. tropicale according to sequences of the β-tubulin-2 gene, indicating that they belong to the Colletotrichum gloeosporioides species complex. This is the first report specifying the genetic relationships of the pathogens of Madagascar periwinkle anthracnose in the complex.     

不同土地利用方式下紫色土中铵的容量和强度（Q/I）关系

研究了4种土地利用方式下(水田、旱地、林地、菜地)紫色土(紫色湿润雏形土)和紫色水稻土(紫色水耕人为土)NH4+的容量和强度(Q/I)关系。结果表明:紫色土和紫色水稻土NH4+Q/I曲线的曲线部分均出现在NH4+的活度比(ARNH4)较低时,表明土壤存在非交换性NH4+(或专性吸附的NH4+)的释放。紫色土和紫色水稻土NH4+的潜在缓冲容量(PBC)为71.47～203.7 cmol kg-1(mol L-1)-1/2;土壤活性NH4+(-ΔNH40)为0.029 5～0.089 7 cmol kg-1,NH4+的平衡活度比(AR0NH4)为0.187×10-3～1.255×10-3(mol L-1)1/2;土壤专性吸附位点(NH4-sas)为0.010 6～0.118 5 cmol kg-1。相关分析和通径分析表明,土壤小于0.002 mm黏粒含量与NH4+PBC及NH4-sas均呈极显著正相关(p<0.01),小于0.002 mm黏粒对PBC的影响主要是间接作用(间接通径系数为0.585),但对NH4-sas则有强烈的直接作用;有机碳与-ΔNH40和AR0NH4均呈极显著正相关(p<0.01),但是有机碳对-ΔNH40有较大的直接效应(直接通径系数为0.966),而对AR0NH4的影响主要以间接效应为主。土壤-ΔNH40与交换性NH4+数值接近且呈极显著相关(r=0.876 4,n=8,p<0.01),而AR0NH4与交换性NH 4+亦呈极显著相关(r=0.983 7,n=8,p<0.01)。土壤小于0.002 mm黏粒和有机碳的差异是导致不同土地利用方式下紫色土交换性NH4+以及Q/I参数的差异的主要原因,交换性NH4+标志的NH4+有效性指标与由Q/I关系得到的NH4+有效性指标类似。     

Soybean preference for Bradyrhizobium japonicum for nodulation

For examining the probability of increase in the occupation ratio of inoculated rhizobium in nodules, various Rj-soybean cultivars including the Rj ₂ Rj ₃ Rj ₄-lines of soybean were grown in a field of the Kyushu University Farm. Bradyrhizobium japonicum USDA110 that carries uptake hydrogenase (Hup⁺) was used as an inoculum. The relative efficiency of nitrogen fixation generally increased by the inoculation. However, there were no significant differences in the effects among the genotypes of the host plants. The occupation ratio of serogroup USDA110 in the nodules on the taproot of the inoculated plants was in the range of 77–100%, suggesting that the B. japonicum strain USDA110 infected taproots immediately after inoculation. The occupation ratios in the nodules on the lateral roots were 53–67, 40–86, 63–83, and 62–77% in inoculated plants of the non-Rj-, Rj ₂ Rj ₃-, Rj ₄-, and Rj ₂ Rj ₃ Rj ₄-genotypes, respectively, and they decreased in all the genotypes with the progression of growth. At the time of the first sampling, the occupation ratios on the lateral roots of these Rj ₂ Rj ₃ Rj ₄-genotypes showed values intermediate between those of IAC-2 (Rj ₂ Rj ₃) and Hill (Rj ₄) , which were the parent cultivars of the Rj ₂ Rj ₃ Rj ₄-lines, B340, B349, and C242. The reduction in the occupation ratio of the serogroup USDA110 for about 1 month after the first sampling was the lowest (0.13–0.16) in the Rj ₂ Rj ₃ Rj ₄-genotypes, excluding B349, followed by the non-Rj- and Rj ₂ Rj ₃-genotypes and highest (0.52–0.69) in the Rj ₄-genotypes, excluding Hill. Therefore, it was considered that the population of compatible rhizobia with host soybean plants increased in the rhizosphere with the progression of the development and growth. The results showed that with the expansion of the root area of host plants, the occupation ratio of type A rhizobia including the serogroup USDA110 was high. Therefore, the Rj ₂ Rj ₃ Rj ₄-genotypes were superior to other Rj-genotypes in terms of the inoculation effects of nodulation type A rhizobium, B. japonicum USDA110. However, the preference of the Rj ₂ Rj ₃ Rj ₄-genotype for serogroup USDA110 is not sufficient to rule out the competition with the other serogroups in this study. Therefore, the study should be centered on the isolation of more efficient (Hup⁺) and highly compatible rhizobial strains with the Rj ₂ Rj ₃ Rj ₄- genotypes.     

Optimizing the application of dairy farm effluent and manure to mitigate gas emission

Journal of Soils and Sediments - The impact of dairy farm effluent and manure applications upon gas emissions from soil is of concern for agronomic, ecological, and environmental reasons. Yet it...     

用探针杂交法检测鸡毒支原体和滑液囊支原体

根据鸡毒支原体(MG)和滑液囊支原体(MS)的16SrRNA基因序列，设计并合成了探针MG和MS共同目的基因，跨幅为580bP的一对引物。用这对引物对2个标准的MG和1个标准的Ms菌株DNA模板进行聚合酶锭反应(PcR)，结果得到了预期大小约580bP的PcR产物。回收纯化琼脂糖电泳凝肢中的MG扩增产物克隆至T载体中，DIG随机引物法合成核酸探针，斑点杂交试验对MG和MS均呈阳性，检测灵敏度分别为2ng和3ng，其它对照菌(毒)株为阴性。