稻田生态系统蜘蛛种群动态的初步研究

自1977～1978年间,在广西北部和中部地区,调查了11个县13个公社的部分山区、平原稻田蜘蛛种类。经鉴定,有11科28种,其中分布普遍数量较多的有球腹蛛科的八斑球腹蛛;微蛛科的食虫瘤胸蛛和草间小黑蛛;狼蛛科的拟水狼蛛和稻田狼蛛(拟环纹狼蛛);长脚蛛科的日本长脚蛛等六种。这些初步被定为优势种。文中揭示了早稻和晚稻两类生态系中的蜘蛛种群结构及其数量变化的差异。早稻前期和中期以微蛛科种群为主,后期以八斑球腹蛛为主;晚稻前期是微蛛和八斑球腹蛛种群为主,两者比数相当,后期以八斑球腹蛛种群占优势。水稻全生育期不使用化学农药,蜘蛛混合种群数量在早稻和晚稻后期达到最高峰。种群数量变动的主要原因及其与稻飞虱、稻叶蝉数量消长的相互关系,受人为因素影响颇大,其中长期大量使用广谱性化学农药和季节性农事操作的变更是种群数量减少的重要原因。试验表明,稻田生态系蜘蛛种群对叶蝉、飞虱有明显控制作用,在实施综合防治措施时应注意保护这一类天敌。     

Correlations between the behavior of recreational horses,the physiological parameters and summer atmospheric conditions

The aim of this paper was to select atmospheric factors and their values, which may disrupt the correct behavior and physiological condition of recreational horses. The studies were carried out from 1 July until 1 September on 16 Anglo‐Arabian geldings. Each day, from 09.00 to 10.00 hours, the horses worked under saddle. The riders and the authors gave a qualitative behavioral assessment for each horse. Mood and willingness to work were evaluated. The quantitative assessment was called ‘incorrect behavior of the horse while riding’ (IBHR). The percentage time of duration and the number of occurrences of the features while riding were calculated. Heart rate, body temperature and respiratory rate were taken at 08.00 hours (resting measurement) and at 10.05 hours (post‐exercise measurement). Air temperature, relative air humidity, wind speed and atmospheric pressure were measured at 08.00 and 10.00 hours. The results showed that adverse changes in the behavior of recreational horses can occur if the horse is ridden when the air temperature is above 26°C and when wind speeds exceed 5.5 m/s. Such conditions may cause a reduction in the mood and willingness to work in horses. Physiological parameters like heart rate and body temperature seem to be more sensitive indicators of the horse body reaction to the weather than behavioral reactions.     

Effect of Iron Status in Rats on the Absorption of Metal Ions from Plant Ferritin

An isolate of lead-ferritin obtained from soybean seeds sprouted in 25 mM of PbNO₃ was introduced into the diet of both iron-deficient and iron non-deficient male rats. After a 21-day administration period, statistical differences in the lead accumulation in the femurs of the rats were noted. Iron-deficient rats accumulated more than four times the amount of lead in their bones than rats without iron-deficiency. No further decrease was observed in haemoglobin concentrations in the groups of animals fed with lead isolates, either iron-deficient or iron non-deficient. Also, no differences in the mean corpuscular haemoglobin (MCH) and mean corpuscular volume (MCV) were observed at the end of the experiment in the group of iron non-deficient rats fed with lead-ferritin isolate compared to the control group of iron non-deficient rats. In the iron-deficient group fed with lead-ferritin isolate, a small increase in haemoglobin concentrations, MCH, MCV and mean corpuscular haemoglobin concentrations (MCHC) was recorded. The results presented in this paper confirm that lead from the tested preparation—lead ferritin isolate—was better absorbed by those rats with induced iron deficiency anaemia. Additionally, we may also suspect based on the obtained results that absorption of ferritin-iron depends on iron status in the body.     

"九五"陕西林业科技进步贡献份额的测算

运用C-D生产函数法和增长速度方程法建立了“九五”陕西林业科技进步对经济增长作用的数学模型,对模型进行了求解和检验,得出陕西林业科技进步贡献份额37.7%的结论,并对结论作了分析和说明。     

Repression of the 14-3-3 gene affects the amino acid and mineral composition of potato tubers

Recently, transgenic potato plants were created showing underexpression of the 20R isoform of the 14-3-3 protein. The transgenic plants grown in tissue culture showed a significant increase in nitrate reductase activity and a decrease in nitrate level. The transgenic line with the lowest 14-3-3 quantity was field-trialed (1997-2000) and analyzed. The reduction in the 14-3-3 protein level consistently resulted in a starch content increase and in an increase in the ratio of soluble sugars to starch in the tubers, although the latter was only barely visible. The determination of amino acid composition in the tubers showed a significant increase in methionine, proline, and arginine content and a slight but consistent increase in hydrophobic amino acid and lysine content in the cells of the transgenic potato plants. We also observed an increase in the crude protein content, from 19 to 22.1% of the control value in consecutive years. It is proposed that all of these changes might have resulted from the downregulation of nitrate reductase and sucrose phosphate synthase activities by 14-3-3, although other potential mechanisms cannot be excluded (e.g., an increase in enzyme protein level). 14-3-3-repressed transgenic plants showed a significant increase in calcium content in their tubers. It is thus proposed that a function of the isolated 14-3-3 isoform is in the control of amino acid synthesis and calcium metabolism. However, the mechanism of this control is as yet unknown.     

致病疫霉对缬菌胺抗性突变体生物学特性及抗性风险量化评估

 通过研究致病疫霉对缬菌胺抗性突变体的生物学特性,评估致病疫霉对缬菌胺产生抗性的风险。采用菌丝生长速率法检测田间菌株对缬菌胺的敏感性;通过比较抗性突变体在无药条件下继代培养前后对缬菌胺的敏感性来确定其抗性稳定性;采用离体叶片法测定抗性突变体及其亲本敏感菌株的适合度和竞争力;通过量化7个基本抗性因素的风险值评估致病疫霉对缬菌胺的基本抗性风险。结果表明:在2018年从内蒙、河北、贵州、四川、黑龙江等五省(自治区)采集分离的153个菌株和2019年从河北、内蒙采集分离的40个菌株中低抗菌株分别占31.4%和35.0%,敏感菌株分别占68.6%和65.0%,抗性指数均为0.34,抗性倍数分别为1.5和2.1,未发现中抗和高抗菌株;8个抗性突变体在无药条件下继代培养10代后,少数抗性突变体的抗药性不能稳定遗传;6个抗性突变体的适合度均显著低于其亲本敏感菌株;4个抗性突变体与其亲本菌株的孢子囊不同比率混合物分别在离体叶片上继代培养1、3、7代的抗性频率显著低于初始抗性频率或与初始抗性频率无显著差异;致病疫霉对缬菌胺7个基本抗性因素的风险值之和为9,推测致病疫霉对缬菌胺的基本抗性风险为低至中等。建议加强致病疫霉菌群体对缬菌胺的抗性监测,将缬菌胺与不同作用机理的杀菌剂交替或混合使用,以延缓抗药性产生和发展。     

西瓜果冻的生产配方

采用L_9(3~3)正交试验法研究西瓜果冻的配方,在单因素试验的基础上,确定了生产色味俱佳的西瓜果冻的最佳配方为:白砂糖25.0 g,卡拉胶7.5 g,西瓜汁1 000 g。     

基于幸福指数视角反思失地农民安置补偿问题的研究——以重庆市北碚区学堂堡安置点为例

失地农民的核心问题是安置补偿问题.通过建立幸福指数测度指标体系,在对学堂堡安置点100户失地农民实际调研的基础上,采用熵值法、合成方法计算幸福指数,并以测度的幸福指数结果为依据反思安置补偿中存在的问题.结果表明:学堂堡安置点失地农民的总体幸福指数不高,处于“不太幸福”的等级.反思主要问题在于住房和货币补偿水平偏低;安置补偿中缺乏科学的就业指导,再就业不理想;社会保障实施范围狭窄等.故必须提高住房和货币安置的补偿标准,完善就业和社会保障机制,建立失地农民诉求渠道,以期恰当解决失地农民的安置问题.     

Comparison of postoperative effects between lidocaine infusion,meloxicam, and their combination in dogs undergoing ovariohysterectomy

ObjectiveTo compare the postoperative analgesic effects of intravenous (IV) lidocaine, meloxicam, and their combination in dogs undergoing ovariohysterectomy.Study designProspective, randomized, double‐blind, controlled clinical trial.AnimalsTwenty‐seven dogs aged (mean ± SD) 16.1 ± 7.5 months and weighing 22.4 ± 17.9 kg scheduled for ovariohysterectomy.MethodsAnaesthesia was induced with propofol and maintained with isoflurane. Dogs (n = 9 in each group) were allocated to receive just prior to and during surgery one of the following regimens: M group, 0.2 mg kg^?1 IV meloxicam then a continuous rate infusion (CRI) of lactated Ringer's at 10 mL kg^?1 hour^?1; L group, a bolus of lidocaine (1 mg kg^?1 IV) then a CRI of lidocaine at 0.025 mg kg^?1 minute^?1; and M + L group, both the above meloxicam and lidocaine treatments. Pain and sedation were scored, and venous samples taken for serum cortisol and glucose measurement before and at intervals for 12 hours after anaesthesia. Pain scores were assessed using a multi‐parameter subjective scoring scale (cumulative scale 0–21) by three observers. The protocol stated that dogs with a total score exceeding 9 or a sub‐score above 3 in any one category would receive rescue analgesia. Sedation was scored on a scale of 0–4.ResultsThere were no significant differences in subjective pain scores, serum cortisol, and glucose concentrations between the three groups. The highest pain score at any time was 5, and no dog required rescue analgesia. None of the three regimens caused any observable side effects during or after anaesthesia. At 1 and 2 hours after extubation dogs in group L were significantly more sedated than in the other two groups.Conclusions and Clinical relevanceThis study suggests that, with the scoring system used, IV lidocaine and meloxicam provide similar and adequate post‐operative analgesia in healthy dogs undergoing ovariohysterectomy.     

红薯品种桂引薯9号的特征特性及其栽培要点

桂引薯9号是从浙江农业科学院作物与核技术利用研究所引进,属弱感光型早熟红薯品种,株型半直立,中短蔓,结薯浅而集中,抗蔓割病;产量高、品质佳、口感粉甜,可在我国南方地区推广种植,春种夏收,夏(秋)种秋(冬)收,产量在26 055-29 565 kg/hm2,高产可达64 695 kg/hm2。