Microbial distribution and function across wheat rhizosphere with oxamide and ammonium sulfate as N sources

Analysis of the effect of slow-releasing N fertilizers on microbial parameters of the rhizosphere soil is essential for their effective use. This investigation revealed the comparative effects of oxamide and ammonium sulfate as different N sources on some selected microbial parameters as well as the pH in the rhizosphere of wheat (Triticum aestivum cv. Nourin No. 61). The study was conducted on a Japanese upland alluvial soil using a rhizobox system. In the central compartment (CC) of the rhizoboxes treated with oxamide and ammonium sulfate, four wheat seedlings were grown for 53 d. In either of the treatments, the pH of the rhizosphere soil increased with the increase in the distance from the CC. In contrast, nitrate production, bacterial and fungal numbers, microbial biomass nitrogen, and β-acetylglucosaminidase activity decreased with the increase in the distance, with the highest values of the respective parameters being recorded in the CC. However, remarkable changes of these microbial parameters were found within a distance of 1–2 mm from the CC to the distant compartments. Thus the results indicated that pH, bacterial number, and nitrate production were high in the oxamide treatment. In contrast, higher fungal number, microbial biomass N, and .B-acetylglucosaminidase activity were associated with the ammonium sulfate treatment. It was assumed that the significant (p<O.05) effect of the rhizosphere on microbial activities varied with the treatments.     

Electroacupuncture-induced neural activation detected by use of manganese-enhanced functional magnetic resonance imaging in rabbits

OBJECTIVE: To investigate the effects of acupuncture on neural activity detected by use of manganese-enhanced functional magnetic resonance imaging (fMRI) and elucidate the relationship between somatic acupoint stimulation and brain activation. ANIMALS: 40 New Zealand White rabbits. PROCEDURE: Manganese-enhanced fMRI was performed in anesthetized rabbits manipulated with electroacupuncture (EA) on Zusanli (ST-36) and Yanglingquan (GB-34) acupoints. Image acquisition was performed on a 1.5T superconductive clinical scanner with a circular polarized extremity coil. T1-weighted images were acquired sequentially as follows: baseline, after mannitol injection, after manganese infusion, and 5 and 20 minutes after initiation of EA. RESULTS: Changes in focal neural activity were detected by use of manganese-enhanced fMRI. Stimulation on Zusanli (ST-36) for 5 minutes resulted in activation of the hippocampus, whereas stimulation on Yanglingquan (GB-34) resulted in activation of the hypothalamus, insula, and motor cortex. Activation became less specific after 20 minutes of EA. Furthermore, stimulation on ipsilateral acupoints led to bilateral brain activation. CONCLUSIONS AND CLINICAL RELEVANCE: Each acupoint has a corresponding cerebral linkage, and stimulation on these points resulted in time-dependent neural activation. Understanding the linkage between peripheral acupoint stimulation and central neural pathways may provide a useful guide for clinical applications of acupuncture.     

苦豆子种子抽提物对两种蔬菜害虫的活性

在害虫防治中,面对化学防治出现的一些问题,本文采集广泛分布于我国西北地区的野生豆科植物苦豆子Sophora alopecuroida(L.),采取有机溶剂制备提取物,测定了对两种蔬菜害虫的生物活性,结果简报如下。 1.1 苦豆子提取物制备及试验方法将苦豆子种子用植物粉碎机粉碎并过40目筛,在实验室以索氏抽提器进行抽提,然后将提取物在旋转蒸发器内蒸干,将此提取物稀释后进行毒力测定。供试虫为萝卜蚜Li-     

光活化农药的研究与应用

结合作者近期的研究工作，对光活化农药的研究现状、作用机理、应用前景及其与新农药创 制的关系进行了综述。     

Hormonal changes and follicular activity after treatment with intravaginal progesterone‐releasing devices in llamas

Plasma progesterone (P₄) concentrations and follicular activity after administration of different P₄ doses were evaluated in 33 adult female llamas treated with intravaginal devices. In Study 1, a group of llamas (n = 10) was treated with an intravaginal device (IVD) containing 160 (n = 5) or 780 mg of P₄ (n = 5). Based on the results from the first study, in Study 2, females with follicles at different stages of development were treated with the IVD containing 780 mg of P₄ (n = 21) or remain untreated (control; n = 12) to evaluate the effect of P₄ on follicular activity. In Study 1, the IVD containing 160 mg of P₄ induced follicular turnover in 60% of females while the remaining 40% of llamas developed persistent follicles. Thus, this device controlled follicular activity in llamas, although it promotes the persistence of follicles present at start of treatment. Conversely, in both studies, the IVD containing 780 mg of P₄ suppressed follicular development and hasten the emergence of a new follicular wave in all females regardless of the follicular phase at insertion. Additionally, in Study 2, this device effectively concentrated the appearance of follicles with ovulatory diameter at a definite time after treatment in comparison with control animals. In conclusion, treatment with an IVD containing 780 mg of P₄ would be considered for the control of follicular activity in llamas as it ensures the presence of a young follicle with ovulatory diameter by day 6 after the end of treatment in all females.     

京郊葫芦科作物花叶病毒的类型初报

从1957到1958年,在北京都区进行了瓜类作物花叶病毒的调查研究。在记述病作物症状的同时,还采集了各类花叶病株的标样,进行了病毒的常规鉴定。西葫芦的花叶病是一个严重的病毒病,鉴定的结果证明其毒原主要为典型的甜瓜花叶病毒(MMV),而且能侵染西瓜而产生系统性花叶症。在南瓜的花叶病标样中分离到的也是甜瓜花叶病毒,但是这个株系不同于典型的甜瓜花叶病毒,因为它们都不侵染西瓜。从黄瓜花叶病标样中分离出来的病毒全属于黄瓜花叶病毒种羣(GMV),其中可能有不同的株系,而秋黄瓜上却分离出了一个毒原,不侵染心叶菸,系统侵染普通菸和毛叶菸,在蔓陀蘿叶上产生局部枯斑而具有较高的致死温度(85℃)。作者认为这可能是一个新单元,称之为秋黄瓜花叶病毒(ACMV)。所有在甜瓜,哈密瓜及绞瓜上分离出来的毒原都是属于典型甜瓜花叶病毒的,但梢瓜(即白瓜)上的毒原都是黄瓜花叶病毒(CMV),没有广州报告的白瓜花叶花病毒。丝瓜花叶病的分离物类似甜瓜花叶病毒,但寄主范围远较狭隘,很可能是一个甜瓜花叶病毒的新株系。     

应用敌百虫防治荔枝蝽象的大田试验

荔枝蝽象是华南地区的重要害虫之一。作者根据此虫自然抗药性季节变化的規律,結合荔枝的开花結果时期,采用有机磷杀虫剂敌百虫0.067％水溶液噴雾于3月中及5月初各噴药一次,防治效果达95％以上。基本可以消灭荔枝蝽象成虫及若虫的为害,达到保花保果的要求。根据試驗結果,掌握上述两个时期大面积噴敌百虫,对荔枝开花、結果以及品质,均无不良影响。噴药时最好暫时关閉蜂箱,噴药后再放蜂。大面积使用敌百虫防治荔枝蝽象,成本低廉,每株药剂及人工費用为0.177元,每亩15株計算,每亩費用为2.65元。防治时期,最好选择能在3—4天內天晴、气温较高、风力0—1級为宜,噴雾要求均匀周到。     

Effects of thinning and pruning on knots and lumber recovery of Taiwania (<Emphasis Type="Italic">Taiwania cryptomerioides</Emphasis>) planted in the Lu-Kuei area

This study investigated the effects of various thinning and pruning methods on the knots (number and size) and lumber recovery from Taiwania (Taiwania cryptomerioides Hay.) plantation trees. The results showed that heavy thinning caused more knots and larger-diameter knots than medium or no thinning; moreover, pruning caused fewer numbers of knots and smaller-diameter knots than no pruning. Better-quality Taiwania trees occurred with the no-thinning/no-pruning treatments, as shown by analyzing the knots, although the results also showed that the healing process seemed to have produced not completely clear wood during the 9 years after the pruning treatment. The thinning intensity slightly enhanced the lumber recovery of logs. Pruning did not affect lumber recovery from taiwania trees and logs. Thinning increased the lumber recovery per tree due to an increase in the diameter at breast height.