Predicting the phenology of codling moth,Cydia pomonella,for sustainable pest management in Swiss apple orchards

The effects of temperature on post‐diapause development, female lifespan, and reproduction of Cydia pomonella L. (Lepidoptera: Tortricidae) were studied under controlled conditions to determine the respective parameters for a temperature‐driven phenology model. Lower thermal thresholds of 10.0 and 9.7 °C and thermal constants of 417.2 and 427.7 degree days were established for post‐diapause development of females and males, respectively. Female lifespan was found to be 202.6 degree days on average, with a lower thermal threshold of 11.2 °C. Total fecundity was highest at 27.7 °C with an average of 241.9 eggs per female. Literature data were used to quantify the lower thermal thresholds and the thermal constants for eggs, larvae, and pupae. For validation, the model was run with weather data from 13 consecutive years and the output was compared with pheromone trap catches from 39 to 63 different orchards, depending on the year. The model proved to be a reliable and useful tool to forecast codling moth phenology under Swiss conditions not only for a whole growing season but also during several years with very variable weather conditions. Hence, it can be used to support apple growers in pest management decisions on the one hand and to predict changes in codling moth phenology with respect to climate change on the other.     

Wall yield threshold and effective turgor in growing bean leaves

The rate of cell enlargement depends on cell-wall extensibility (m) and on the amount of turgor pressure (P) which exceeds the wall yield threshold (Y). The difference (P-Y) is the growth-effective turgor (P _e). Values of P, Y and P _ehave been measured in growing bean (Phaseolus vulgaris L.) leaves with an isopiestic psychrometer, using the stress-relaxation method to derive Y. When rapid leaf growth is initiated by light, P, Y and P _eall decrease. Thereafter, while the growth rate declines in maturing leaves, Y continues to decrease and P _eactually increases. These data confirm earlier results indicating that the changes in light-stimulated leaf growth rate are primarily controlled by changes in m, and not by changes in P _e. Seedlings incubated at 100% relative humidity have increased P, but this treatment does not increase growth rate. In some cases Y changes in parallel with P, so that P _eremains unchanged. These data point out the importance of determining P _e, rather than just P, when relating cell turgor to the growth rate.Abbreviations and symbols FC fusicoccin - m wall extensibility - P turgor pressure - P _e effective turgor - RH relative humidity - Y yield threshold - _w water potential - _s osmotic potential     

猫脊髓背角双投射神经元的外周传入特性

电刺激猫颈髓背索和背外侧索可双重地逆向激动同侧腰骶髓背角神经元。该神经元对非伤害性和伤害性皮肤刺激发生反应;对电刺激其感受野的反应具有单突触性、低阈值和传导快等特征;该神经元的突触前和突触后纤维的传导速度相似,但不具正变关系。结果表明,SCT-DCPS神经元具有低阈机械感受型和广动力范围型两种生理学模型;从A_β传人接受输入并与之构成单突触联系;其突触前纤维直径与突触后纤维直径之间不具匹配关系。     

The inhibitory effect of NaCl on barley germination

Abstract The possibility that the nature of the inhibitory effect of NaCl is different during imbibition compared to germination was investigated. Germination in both NaCl and betaine (a non-toxic solute) improved with pre-imbibition in water. Seeds imbibed in inhibitory concentrations of either solute could be induced to germinate by brief exposure to water. Electron micrographs of tissue from seeds imbibed in 0.5 kmol m^?3 NaCl for 25 h showed cells identical to those in seeds imbibed in water for only 1 h, but seeds imbibed for 6 h in water exhibited many changes in ultrastructure. These results are consistent with the hypothesis that seed hydration must reach a critical value before germination can proceed, and that the inhibitory effect of NaCl is primarily osmotic in barley seeds that have not reached this hydration threshold. Although isotonic solutions of betaine and NaCl were equally inhibitory to germination, isotonic solutions of betaine and NaCl were not equally inhibitory to continued development in seeds which had been pre-imbibed in water. Calcium ions improved both germination and plumule emergence of pre-imbibed seeds in NaCl solutions, but calcium had little effect on pre-imbibed seeds placed in betaine. Very high concentrations of NaCl or betaine inhibited germination, but did not kill dry seeds. Both solutes, on the other hand, were lethal at high concentrations to germinating seeds. NaCl killed germinating seeds more rapidly than betaine, but calcium reduced the rate of killing to nearly that of betaine. We conclude that hydrated seeds are sensitive to both osmotic and toxic effects of NaCl and that calcium mitigates the toxic effect of NaCl, but not the osmotic effect.     

逐级递增负荷踏车试验测定最大耗氧量和无氧阈的重复性

本文目的旨在研究在逐级递增负荷踏车试驻中测定最大耗氧量和无氧阈的重复性。21名运动员各完成三次重复性递增负荷踏车试验。通过与Apple Ⅱ_E计算机辅助联机的Jaeger EOS自动分析系统,根据通气和气体交换参数的变化,对无氧阈及最大耗氧量进行无创性测定。结果表明,采用递增负荷踏车试验测定最大耗氧量时,有必要对不熟悉试验程序的受试者进行重复测定以提高准确性,无创性测定无氧阈具有令人满意的重复性,多次重复测定将可提高无氧阈测定的准确性。     

The effects of specificity of training on rating of perceived exertion at the lactate threshold

To determine the effects of cycle and run training on rating of perceived exertion at the lactate threshold (LT), college men completed a 40-session training program in 10 weeks (n = 6 run training, n = 5 cycle training, n = 5 controls). Pre- and post-training variables were measured during graded exercise tests on both the bicycle ergometer and treadmill. ANOVA on the pre- and post-training difference scores resulted in similar improvements in VO2max for both testing protocols, regardless of training mode. The run training group increased VO2 at the LT by 58.5% on the treadmill protocol and by 20.3% on the cycle ergometer. Cycle trainers increased VO2 LT only during cycle ergometry (+38.7%). No changes were observed in the control group. No differences for RPE at the LT were found before or after training, or between testing protocols for any group. Perception of exercise intensity at the LT ranged from "very light" to "light". The relationship between RPE and %VO2max was altered by the specific mode of training, with trained subjects having a lower RPE at a given %VO2max (no change in RPE at max.). It was concluded that RPE at the LT was not affected by training, despite the fact that after training the LT occurs at a higher work rate and was associated with higher absolute and relative metabolic and cardiorespiratory demands.     

The effects of training on the metabolic and respiratory profile of high-intensity cycle ergometer exercise

The tolerable work duration (t) for high-intensity cycling is well described as a hyperbolic function of power (W): W = (W'.t-1) + Wa, where Wa is the upper limit for sustainable power (lying between maximum W and the threshold for sustained blood [lactate] increase, theta lac), and W' is a constant which defines the amount of work which can be performed greater than Wa. As training increases the tolerable duration of high-intensity cycling, we explored whether this reflected an alteration of Wa, W' or both. Before and after a 7-week regimen of intense interval cycle-training by healthy males, we estimated ( ) theta lac and determined maximum O2 uptake (mu VO2); Wa; W'; and the temporal profiles of pulmonary gas exchange, blood gas, acid-base and metabolic response to constant-load cycling at and above Wa. Although training increased theta lac (24%), mu VO2 (15%) and Wa (15%), W' was unaffected. For exercise at Wa, a steady state was attained for VO2, [lactate] and pH both pre- and post-training, despite blood [norepinephrine] and [epinephrine] ([NE], [E]) and rectal temperature continuing to rise. For exercise greater than Wa, there was a progressive increase in VO2 (resulting in mu VO2 at fatigue), [lactate], [NE], [E] and rectal temperature, and a progressive decrease for pH. We conclude that the increased endurance capacity for high-intensity exercise following training reflects an increased W asymptote of the W-t relationship with no effect on its curvature; consequently, there is no appreciable change in the amount of work which can be performed above Wa.(ABSTRACT TRUNCATED AT 250 WORDS)     

Discrimination of objects through electrolocation in the weakly electric fish,Gnathonemus petersii

Summary Three weakly electric fish (Gnathonemus petersii) were force-choice trained in a two-alternative procedure to discriminate between objects differing in their electrical characteristics. The objects were carbon dipoles in plexiglass tubing (length 2.5 cm, diameter 0.6 cm). Their electrical characteristics could be changed by varying the impedance of an external circuit to which they were connected (Fig. 1). In one (the capacitance dipole) the resistance was very low(< 3 ) and the capcitance variable. In the other (the resistance dipole) the resistance was variable and the capacitance low (<50 pF).Capacitances from several hundred pF (lower thresholds, Fig. 2) to several hundred nF (upper thresholds, Fig. 3) could be discriminated from both insulators and good conductors. In all cases the reward-negative stimulus was the capacitance dipole, which was avoided by all fish spontaneously. Thresholds were defined at 70% correct choices.The fish were then tested for their ability to discriminate between one object with a given capacitance and another with resistances varying from 3 to 200 k. The capacitance dipole continued to be the negative stimulus throughout. All 3 fish avoided it in at least 80% of the trials at each stimulus combination (Fig. 4). This result suggests that Gnathonemus perceives the capacitance and the resistance of objects differentially.The effect of the dipole-objects as well as some natural objects on the local EOD was recorded differentially very close to the fish's skin (Fig. 5). The amplitude of the local EODs was affected by all types of objects as they approached the skin. However, the waveform was changed only by capacitance dipoles and some natural objects (Figs. 6 and 7). It appears that the fish perceive not only intensity changes in the local EOD but wave-form deformations as well and can thus distinguish objects of different complex impedances.Abbreviations EOD electric organ discharge - f _max maximal spectral frequency - GP Gnathonemus petersii - LFS local filtered signal - PMA probing motor act - S+ positive stimulus - S negative stimulus     

中枢催产素在电针镇痛中的作用

本工作以钾离子透入法引起大鼠甩尾反应的电流强度(mA)为痛反应指标,观察了侧脑室注射催产素(OT)及抗催产素血清(AOTS)对大鼠痛阈和电针镇痛效应的影响。注射50 ngOT 后80min 内,大鼠痛阈比注药前增加20—38%。与注射生理盐水组的痛阈相比有非常明显的增高(p<0.01—0.001),侧脑室注射 OT 后电针期内,痛阈增加139—234%,与生理盐水电针组相比,有显著差异(P<0.05—0.01)。OT 的剂量在25—100ng 范围内,其增强电针镇痛效应有明显的剂量-效应关系。注射 AOTS 后,电针镇痛应明显低于注射正常兔血清(NRS)组(p<0.05—0.01)。上述结果表明,侧脑室注射 OT,既可提高痛阈又可明显地增强电针镇痛效应,而用 AOTS消除内源性 OT 的作用后,电针镇痛效应明显降低。这提示,中枢神经系统内的 OT 在电针镇痛过程中,发挥一定的作用     

稻纵卷叶螟为害损失率测定及动态经济阈值模型研究初报

室内饲养观察稻纵卷叶螟(Cnaphalocrocis medinalis)5龄幼虫食量最大,第1、2代占总食叶量的68.42％和71.60％,4龄次之,第2、3代分别占总食叶量的18.30％和15.78％。因此,幼虫消灭在3龄以前可控制为害。对不同为害程度与水稻产量损失量关系进行了测定和分析,结果表明,第2代为害主要可使千粒重降低,同时对每穗粒数和空壳率也有较大影响。第3代为害主要表现在空壳率的上升和千粒重下降。第2代主要为害倒4、5叶,少量为害有一定的增产作用;而第3代主要为害剑叶和倒2叶,产量损失明显地大于第2代,是防治的关键世代。根据研究结果可得出不同世代、不同虫龄盛发期的动态经济阈值模型。