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341.
研究伞伐更新法对赫卡尼亚森林系统中森林再生和林分结构的影响。在伊朗北部优势种为山毛榉(Fagus orientalisLipsky)的硬木林,采取伞伐更新法和非伞伐更新法方法设计实验区。结果表明,在山毛榉(F orientalis Lipsky)林中采用伞伐更新法处理,明显影响林下草本植物种的频度和密度。伞伐更新法处理后,林堇菜(Viola silvestris Lam.)、车叶草(Asperula odorata L.)、苔草(Carex spp.)和悬钩子(Rubushyrcanus Juz)的种频度明显增加。在对照区,树种的胸高直径(57.50±2.15cm)大于被处理区(50.67±1.88cm)的树种的胸高直径(50.67±1.88 cm),但对照区和处理区的树种的高度值相似。在1995-2005年间,波斯铁木(Parrotia persica)苗木数量增加到13.2%,而山毛榉(F orientalis)和欧洲鹅耳枥(Carpinus betulus)的苗木数量却明显减少。总之,应该利用其它育林方法,如,带状择伐作业,而不是伞伐更新法培育赫卡尼亚森林中山毛榉林。  相似文献   
342.
根据2008~2009年实地考察研究结果,着重就该区2种有蹄类动物的分布、种群数量以及有关问题作概要性探讨。调查研究结果表明:(1)老虎台盘羊分布区盘羊平均密度=8.49/8=1.06只/km^2,黑英山盘羊分布区盘羊平均密度=5.34/3=1.78只/km^2。整个分布区盘羊种群数量1 488只,其中,老虎台分布区种群数量=480×1.06=509只,黑英山分布区种群数量=550×1.78=979只。(2)老虎台北山羊分布区北山羊平均密度=14.59/5=2.92只/km^2,黑英山北山羊分布区北山羊平均密度=7.01/4=1.75只/km^2。整个分布区北山羊种群数量5 604只,其中,老虎台分布区种群数量=1 200×2.92=3 504只,黑英山分布区种群数量=1 200×1.75=2 100只。以上数据为该区2种野生有蹄类动物开展狩猎与保护提供了对策性依据。  相似文献   
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344.

Background

Recently, botulinum neurotoxin (BoNT)-derived recombinant proteins have been suggested as potential botulism vaccines. Here, with concentrating on BoNT type E (BoNT/E), we studied two of these binding domain-based recombinant proteins: a multivalent chimer protein, which is composed of BoNT serotypes A, B and E binding subdomains, and a monovalent recombinant protein, which contains 93 amino acid residues from recombinant C-terminal heavy chain of BoNT/E (rBoNT/E-HCC). Both proteins have an identical region (48 aa) that contains one of the most important BoNT/E epitopes (YLTHMRD sequence).

Methods

The recombinant protein efficiency in antibody production, their structural differences, and their BoNT/E-epitope location were compared by using ELISA, circular dichroism, computational modeling, and hydrophobicity predictions.

Results

Immunological studies indicated that the antibody yield against rBoNT/E-HCC was higher than chimer protein. Cross ELISA confirmed that the antibodies against the chimer protein recognized rBoNT/E-HCC more efficiently. However, both antibody groups (anti-chimer and anti-rBoNT/E-HCC antibodies) were able to recognize other proteins. Structural studies with circular dichroism showed that chimer proteins have slightly more secondary structures than rBoNT/E-HCC.

Conclusion

The immunological results suggested that the above-mentioned identical region in rBoNT/E-HCC is more exposed. Circular dichroism, computational protein modeling and hydrophobicity predictions indicated a more exposed location for the identical region in rBoNT/E-HCC than the chimer protein, which is strongly in agreement with immunological results. Iran. Biomed. Key Words: Botulinum neurotoxin type E (BoNT/E), Cross ELISA, circular dichroism, Computational modeling, recombinant vaccine-candidates  相似文献   
345.
Effect of PRD (partial rootzone drying) on yield and yield components of canola (Brassica napus L.) was investigated in greenhouse conditions. The treatments were: T1, full watering of both sides of roots; T2, alternate irrigation on both sides; T3, half of irrigation water in T1 was given to one side; T4, same as T3 but without plate; T5, same as T2 but without plate. In T1, T2, and T3 treatments, the boxes were evenly separated into two compartments with thin plates. The results showed that grain yield of T1 to T5 treatments was 18.11, 16.38, 12.44, 9.29, and 8.66 g plant−1. T2 treatment increased plant height by 46.9% and 1000-seed weight by 17.8%, but reduced lateral branches by 16.7% and number of pods by 24%, over T1 treatment. T2 treatment was the most efficient (irrigation water use efficiency = 0.679 kg m−3) and treatment T5 was the least efficient (0.359 kg m−3). The difference between irrigation water use efficiency (IWUE) of T2 and T5, and T3 and T4 treatments, was significant (p < 0.05). Therefore, halving the amount of applied irrigation water and applying this water alternatively on both sides of the root zone will produce the highest IWUE. This study showed that PRD irrigation management has high influence on rooting system of canola. This phenomenon could affect nutrients uptake and consequently all aspects of plant growth and development.  相似文献   
346.
应用23个形态学特征,19个扩增片段长度多态性(AFLP)引物组合,80个随机扩增多态DNA(RAPD)引物和32个简单序列重复(SSR)引物对,比较三种分子标记法在29个杏仁栽培种和3个野生种遗传关系构建中的信息景和效率.根据预期杂合度的评价,与AFLPs和RAPDs相比,SSRs具有较高水平的多态性和较大的信息量.AFLPs预期朵合度值最低,但其辨别效率值最高,因为AFLPs能揭示每个反应中的大量条带,导致各种类型的多样性指数均较高.三种分子标记法对杏仁基因型的辨别效率均较高,只是SSRs无法辨别‘Monagha'和‘Sefied'杏仁基因型.三种分子标记法基因型相似性相关系数统计上显著,但SSR数据要低于RAPDs和AFLPs的值.尽管三种分子标记法树形图拓扑结构存在一些差异,但相似性水平均较高.SSRs、RAPDs和AFLPs的系统树图及其综合数据都能依据地理散布反映大多数栽培种的关系.AMOVA检测到每个地理组中栽培种和野生种的变异.辅助程序分析表明,实验所应用的标记物数量足以保证基因相似性估计的可靠性和标记法间的比较是有意义的.  相似文献   
347.
Gas exchange was measured in potatoes (cv. Folva) grown in lysimeters (4.32 m2) in coarse sand, loamy sand, and sandy loam and subjected to full (FI), deficit (DI), and partial root-zone drying (PRD) irrigation strategies. PRD and DI as water-saving irrigation treatments received 65% of FI and started after tuber bulking and lasted for six weeks until final harvest. Midday photosynthesis rate (An) and stomatal conductance (gs) of fully irrigated (FI) plants were lowest in coarse sand and mean An of diurnal measurements in FI, PRD and DI tended to be lower in this soil as compared with the loamy sand and sandy loam. The results revealed that diurnal values of An and gs in PRD and DI were consistently lower than FI without reaching significant differences in accordance with findings that xylem [ABA] in PRD was significantly higher than FI, and tended to be higher than in DI. Diurnal measurements showed that An reached peak values during mid-morning and midday, while gs were highest during the morning. Intrinsic water use efficiency (An/gs) correlated linearly well with the leaf to air vapor pressure deficit (VPD) and the slope of the line revealed the rate of An/gs increase per each kPa increase in VPD, i.e. approximately 10 μmol mol−1. Transpiration efficiency (An/T) of PRD was higher than DI, which shows slightly better efficient water use than DI. The slope of the linear relationship between transpiration efficiency and VPD decreased from −2.03 to −1.04 during the time course of the growing season, indicating the negative effect of leaf ageing on photosynthesis and thus on plant water use efficiency. This fact shows the possibility to save water during last growth stages through applying water-saving irrigations without much effect on transpiration efficiency.  相似文献   
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349.
The present study assessed the effects of dietary turmeric on Cyprinus carpio resistance and responses to copper exposure. First, the fish were assigned to four treatments received diets supplemented with 0 (control), 5, 10 and 20 g/kg turmeric for 3 weeks. Thereafter, the fish were exposed to lethal concentration (3.5 mg/L) of ambient copper for 24 hr and mortality was 65.3%, 41.8%, 22.7% and 20.6%, respectively. In the second experiment, the fish were fed with the aforementioned diets and simultaneously exposed to sub‐lethal concentration (0.25 mg/L) of ambient copper for 3 weeks. Copper exposure led to increases in plasma cortisol, glucose, malondialdehyde (MDA), alanine transaminase (ALT) and aspartate transaminase (AST), and decrease in plasma T4, T3, lysozyme, alternative complement haemolytic (ACH50), bactericidal activities, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and blood red blood cell count (RBC) and haemoglobin. Moreover, copper exposure led to significant upregulation of tumour necrosis factor‐alpha (TNF‐a) and interleukin 1‐beta (IL1‐b), and significant downregulation of interleukin 10 (IL10) gene expressions in the fish liver. Turmeric administration at 10 g/kg significantly mitigated/inhibited the copper‐induced negative effects, which seems to be due to the augmenting of the antioxidant defence.  相似文献   
350.
Angelwing clam were induced to spawn by thermal stimulation. Mature eggs measured 50 μm in diameter. Cell division occurred within 36 min after fertilization. Mobile trochophore larvae were seen after 12 h and larvae developed within 18 h. Reared on a diet of Isochrysis galbana the larvae reached the umbo stage in 6–7 days. On day 10 the foot could be seen and settlement occurred if a suitable substrate was present. The larvae completed metamorphosis into juveniles within 20 days after settling.  相似文献   
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