甘肃省坡耕地利用状况与退耕还林还草技术对策研究

对甘肃省坡耕地的利用状况及其退耕的可行性进行了较为全面的分析,按照因地制宜的原则,将退耕区域划分为陇中黄土丘陵沟壑区、陇东黄土台塬区、山高坡陡的陇南山区与河西防风固沙区四大区,并就各区退耕后的还林还草方式进行了具体的论证,提出了15°～25°和25°以上坡耕地退耕还林还草的具体技术对策。     

刑法中身份的概念与特征辨正

刑法中的身份是指刑法中对定罪、量刑具有影响的个人人身方面的客观要素。它具体包括行为人的身份、刑事被害人的身份和行为对象人的身份三种,其中后二者是交叉关系。在这些身份中,既包括刑法明文规定的身份,也包括虽然刑法没有明文规定,但却对定罪、量刑有影响的身份;既包括自然人的身份,也包括单位的身份。刑法中的身份有五个方面的特征,即客观人身性、有效性、针对性、相对性和先在性。     

A bio-economic modelling project for small-scale milk production systems in South-East Brasil

This paper reports on the development and use of a bioeconomic model to simulate dairy enterprises in the Zona da Mata of Minas Gerais State in south-east Brasil.In view of the relatively small size of the units, each animal within the herd is accounted for on an individual basis and the main biological events and processes are treated stochastically. Within the limits of given herdranges for genetic potentials, actual rates of performance are estimated from the levels of feeding and other management factors. An energy balance approach is used to assess the contributions of pasture, cut forage and concentrates in the diet.The model has been used to help in identifying priority areas for applied research, to explore various combinations of herd potential and level of feeding, the behaviour of different herd sizes and the potential returns from specific technical innovations.     

Action potential and contraction of Dionaea muscipula (Venus flytrap)

Observation of the action potential and contraction of the leaf of Dionaea muscipula Ellis revealed several interesting phenomena. Two successive stimuli are generally necessary to cause contraction. The first and ineffective stimulus is associated with slow depolarization. The second stimulus has much more rapid depolarization and initiates contraction.     

The susceptibility of domestic cats (Felis catus) to experimental infection with Leishmania braziliensis

Over the last few years, several cases of feline leishmaniasis (FL) with cutaneous and visceral forms have been reported around the world. Nonetheless, the real susceptibility of cats to infection with Leishmania spp. and the outcome of leishmaniasis in these animals are poorly understood. Experimental studies on feline models will contribute to the knowledge of natural FL. Thus, in order to determine the susceptibility of domestic cats (Felis catus) to experimental infection with Leishmania braziliensis, 13 stray cats were infected with 10(7) promastigotes by the intradermal route in the ear and nose simultaneously and followed up for 72 weeks. Soon after infection, the earliest indication of a lesion was a papule on the ear at 2 weeks post-infection (w.p.i.). The emergence of satellite papules around the primary lesion was observed about 4 w.p.i. Two weeks later these papules coalesced and formed a huge and irregular nodule. Thereafter, there was lesion dissemination to the external and marginal surface of the ipsilateral ear, and later to the contralateral ear. At 10 w.p.i., some nodules became ulcerated. Nose lesions presented a similar evolution. At both sites, the largest lesion sizes occurred at 10 w.p.i. and started to decrease 15 days later. Ear and nose nodules healed at 32 and 40 w.p.i., respectively. Specific L. braziliensis IgG antibody titers (optical density> or = 0.01 as positive result) were detected as early as 2 w.p.i. (0.09 +/- 0.02) in only three animals (23%), and all cats had positive titers at 20 w.p.i. (0.34 +/- 0.06). Only three animals (38%) continued to show positive serology at 72 w.p.i. (0.08 +/- 0.02). Up to that time, none of the cats had lesion recurrence. In a feline model of cutaneous leishmaniasis, it seems that there is no correlation between active lesions and positive serology. The implications of these data are discussed.     

抗虫棉群体NPt-Ⅱ标记基因纯度与其抗虫性强度的相关分析

研究了转基因抗虫棉标记基因纯度与生物学抗虫性的相关特性,结果显示:综合平均抗性指数与棉苗群体抗虫标记基因纯度两者呈极显著的正相关,即品种群体抗虫标记基因的纯度愈高,其生物学抗虫性愈强。通过提高转基因抗虫棉Npt Ⅱ标记基因纯度,可显著提高该品种的群体生物学抗虫性;进而通过苗床去杂保纯技术,达到跟踪保持抗虫棉群体抗虫性的目的。     

Pseudopregnancy in Saanen Goats (Capra hircus) Raised in Northeast Brazil

The prevalence of pseudopregnancy over 44 months was investigated in 23 Saanen goats raised in Northeast Brazil during continuous oestrous cycling (cyclic group) or after synchronization of oestrus (synchronized group). The goats were monitored by ultrasonography and their plasma progesterone profile. The overall prevalence of pseudopregnancy was 30.4% (7/23). In the cyclic group, 28.6% (4/14) of goats showed pseudopregnancy, while in the synchronized group the prevalence was 33.3% (3/9). There was no significant difference between the groups (p>0.05). The mean (+/- SD) length of pseudopregnancy, as shown by the progesterone profile, was 121.6 +/- 33.5 days, ranging from 70 to 155 days. The study defined the prevalence of pseudopregnancy in Saanen goats raised in Northeast Brazil for the first time. This finding identified a major problem for this breed, as without treatment such animals remain unproductive until the spontaneous resolution of the condition. More research seems desirable to ascertain the prevalence of this condition in other breeds in this region of Brazil.     

Comparison of hemodynamic, clinicopathologic, and gastrointestinal motility effects and recovery characteristics of anesthesia with isoflurane and halothane in horses undergoing arthroscopic surgery

OBJECTIVE: To compare hemodynamic, clinicopathologic, and gastrointestinal motility effects and recovery characteristics of halothane and isoflurane in horses undergoing arthroscopic surgery. ANIMALS: 8 healthy adult horses. PROCEDURE: Anesthesia was maintained with isoflurane or halothane (crossover study). At 6 intervals during anesthesia and surgery, cardiopulmonary variables and related derived values were recorded. Recovery from anesthesia was assessed; gastrointestinal tract motility was subjectively monitored for 72 hours after anesthesia. Horses were administered chromium, and fecal chromium concentration was used to assess intestinal transit time. Venous blood samples were collected for clinicopathologic analyses before and 2, 24, and 48 hours after anesthesia. RESULTS: Compared with halothane-anesthetized horses, cardiac index, oxygen delivery, and heart rate were higher and systemic vascular resistance was lower in isoflurane-anesthetized horses. Mean arterial blood pressure and the dobutamine dose required to maintain blood pressure were similar for both treatments. Duration and quality of recovery from anesthesia did not differ between treatments, although the recovery periods were somewhat shorter with isoflurane. After isoflurane anesthesia, gastrointestinal motility normalized earlier and intestinal transit time of chromium was shorter than that detected after halothane anesthesia. Compared with isoflurane, halothane was associated with increases in serum aspartate transaminase and glutamate dehydrogenase activities, but there were no other important differences in clinicopathologic variables between treatments. CONCLUSIONS AND CLINICAL RELEVANCE: Compared with halothane, isoflurane appears to be associated with better hemodynamic stability during anesthesia, less hepatic and muscle damage, and more rapid return of normal intestinal motility after anesthesia in horses undergoing arthroscopic procedures.     

Critical disease components of common bacterial blight to effectively evaluate resistant genotypes of snap bean

Common bacterial blight (CBB) caused by Xanthomonas axonopodis pv. phaseoli (Xap) is the main bacterial disease of snap bean. The present work aimed to select snap bean genotypes that are resistant to CBB based on three components of resistance: area under the disease progress curve, latent period, and lesion diameter on pods (DL). A completely randomized two-factor factorial design with six replications was used to evaluate leaves and pods of 14 snap bean and three common bean genotypes (PI 207262, BAC-6 and A-794) with high resistance to CBB. Two Xap isolates, 1394-98 and 775-90, were used to inoculate leaves and pods. Data were analyzed using nonparametric statistics. Significant differences were observed among the evaluated genotypes for all of the components of resistance, except for DL. The snap bean UENF 1482 demonstrated good performance in two disease resistance components. For this reason, this genotype can be recommended for use in breeding programs that aim to generate snap bean genotypes resistant to Xanthomonas axonopodis pv. phaseoli.     

吉林省水稻品种遗传改良过程中地上干物质积累特性

以吉林省1958-2004年间育成的14个水稻品种为试材,研究了齐穗前后的干物质生产特性及其与产量的关系.结果表明:产量、生物量和收获指数随育成年代的增加而显著增加,47年来分别增加了66.9％、28.1％、14.8％.齐穗后干物质积累量随育成年代增加显著增加且与产量呈显著正相关(0.650**),且占经济产量的比例为58.3％～99.0％;齐穗前干物质积累量与产量无显著相关关系,但齐穗前同化物转移到子粒产量的贡献率存在基因型显著差异,变幅为41.7％～1.0％.分蘖至齐穗期单茎净干物质积累量与产量的相关系数为0.656**,齐穗至齐穗后10 d的叶片净同化速率和穗增重速率与育成年代和产量均呈显著正相关.因此,单茎干重可作为早期衡量水稻群体结构是否合理的一个有效监测鉴别指标,进一步提高吉林省水稻产量应注重提高齐穗后群体的干物质生产能力.