浅谈葡萄与葡萄酒工程专业学生实践能力训练的改革--以青岛农业大学葡萄与葡萄酒工程专业为例

葡萄与葡萄酒工程专业是一个注重实践动手能力的学科,该文首先提出现在实践能力培养中存在的问题,并针对问题相应地提出了实践能力训练改革的方向和措施。     

Cervix–rectum temperature differential at the time of insemination is correlated with the potential for pregnancy in dairy cows

This study sought to establish whether temperature gradients between the cervix, vagina, and rectum at and 7 days post-artificial insemination (AI) were associated with the incidence of pregnancy in lactating dairy cows (Experiment I; n = 90 ovulating cows) and to evaluate temperature gradient dynamics from the time of insemination to 7 days post-AI under heat stress conditions (Experiment II; n = 16 ovulating and 4 non-ovulating cows). In Experiment I, 39 cows (43.3%) became pregnant. The odds ratio for pregnancy was 2.5 for each one-tenth of a degree drop in cervical temperature with reference to the control rectal temperature at the time of AI (P = 0.01), whereas the same decrease in the cervix–rectum temperature differential 7 days post-AI resulted in an odds ratio of 0.44 (P = 0.02). In Experiment II, 5 of the ovulating cows (31.3%) became pregnant. The mean values of the vagina–rectum, vagina–cervix, and cervix–rectum temperature differentials at AI (day 0), 8 h, 24 h, and 7 days post-AI changed significantly from day 0 to day 7 (within-subject effect; P < 0.02) in ovulating cows but not in non-ovulating cows. Temperature differentials on days 0 and 7 were similar between ovulating cows and cows of Experiment I. Overall, our findings support the notion that a temperature differential between the caudal cervical canal and rectum at AI may be an indicator of the likelihood of pregnancy. Possible prospects of confirming estrus at the herd-level are also suggested.     

The effect of harvest time and pre harvest treatment on the moisture content of Miscanthus × giganteus

This study aims to determine the most appropriate time to harvest Miscanthus × giganteus between January and April, over three possible harvest windows (Jan, Feb and Mar), relative to the harvest method being employed to cut the crop. The moisture content (MC) of biomass cut in January increased compared to the standing crop (control). From an initial MC of 53% in 2009 and 63% in 2010, the control was 12% and 13% lower than Cut Jan after 4 weeks of the treatment in respective years. The MC of Cut Feb was 19% lower than the control after 4 weeks in 2009. Despite Cut Feb being 4% higher than the control after one week in 2010, both treatments reached 34% MC after 3 weeks. A difference of 16% occurred between the Cut Mar and the control after one week in 2009 while in 2010 Cut Mar was 5% higher than the control after one week. Examining the relationship between stem MC, meteorological parameters and evapotranspiration showed that a combination of relative humidity and evaporation rate (Penman equation.) demonstrated the strongest relationship with crop MC. If harvesting early, lower MC can be achieved by cutting and collecting the crop immediately. An increase in the rate of moisture loss can be achieved later in spring by cutting the material and allowing it to dry for a period of time prior to collection if suitable drying conditions occur. An analysis across several sites showed that such conditions are most likely to occur in February.     

Inhibitory effect of zacopride on ouabain-induced arrhythmias in adult rats

AIM: To investigate the effect of zacopride, an inward rectifier potassium channel agonist, on ouabain-induced arrhythmias in adult rats, and to explore the underlying electrophysiological mechanism.METHODS: Using ouabain to establish in vitro and in vivo arrhythmic rat models, the effects of zacopride on ouabain-induced arrhythmias were observed. The technique of whole-cell patch clamp was used to observe the effects of zacopride on inward rectifier potassium current (I_K1), resting membrane potential (RMP) and delayed afterdepolarizations (DADs) in single rat ventricular myocyte. RESULTS: Zacopride at 1 μmol/L significantly reduced total number of premature ventricular beats, and the duration and incidence of ventricular tachycardia and ventricular fibrillation induced by ouabain in rat hearts in vitro (P<0.05). In anesthetized rats, zacopride at 15 μg/kg significantly reduced total number of premature ventricular beats, and the duration and incidence of ventricular tachycardia and ventricular fibrillation induced by ouabain (P<0.05). I_K1 was significantly inhibited by ouabain (P<0.05), which was partially and even completely reversed by zacopride at 0.1~10 μmol/L. RMP value was significantly reduced by ouabain (P<0.05), and then increased to different levels after treatment with zacopride (0.1~10 μmol/L). Zacopride at 1 μmol/L showed its maximal effect and RMP was restored to normal level. Moreover, zacopride at 1 μmol/L markedly suppressed ouabain-induced DADs in single rat ventricular myocyte. The incidence of DADs decreased from 91.67% to 12.50% after zacopride was applied (P<0.05), and this effect was abolished by 1 μmol/L BaCl₂. CONCLUSION: Inward rectifier potassium channel agonist zacopride significantly inhibits ouabain-induced ventricular arrhythmias in adult rats. The mechanism is related to increased RMP level and inhibition of DADs by activation of I_K1 channel.     

Rice growth, yield and water productivity responses to irrigation scheduling prior to the delayed application of continuous flooding in south-east Australia

The majority of rice grown in south-east Australia is continuously flooded for much of its growing season, but reduced irrigation water availability brought about by a combination of drought and environmental flow legislation has presented a need to maintain (or even increase) rice production with less irrigation water. Delaying the application of continuous flooding until prior to panicle initiation can increase input water productivity by reducing non-beneficial evaporation losses from free water and the soil. A field experiment was conducted over two growing seasons, 2008/9 and 2009/10, comparing a conventional dry seeded treatment (the control - continuous flooding from the 3 leaf stage) with delayed continuous flooding (10-20 days prior to panicle initiation) with several irrigation scheduling treatments prior to flooding commencement. In the first year, the delayed water treatments were irrigated at intervals of 40, 80 and 160 mm of cumulative reference evapotranspiration (ETo) prior to delayed continuous flooding, thereby imposing differing degrees of crop water stress. In year 2, the 80 and 160 mm treatments were modified by use of a crop factor (Kc) when the plants were small and the 40 mm treatment was replaced with a continuously flooded treatment throughout the crop duration.Decreases in net water input (irrigation + rain − surface drainage) and increases in input water productivity were achieved by reducing the flush irrigation frequency during the pre-flood period. Savings of 150 and 230 mm (10 and 15%) were achieved in Year 1 from the 80 and 160 mm cumulative ETo irrigation frequency treatments, respectively, in comparison to the control. In the second year, net water input savings of 230 and 330 mm (15 and 22%) were achieved with the 80/Kc and 160/Kc mm treatments, respectively. Input water productivity of the 160 mm treatment was 0.06 kg/m³ (8%) higher than the control in Year 1, while in Year 2 a 0.15 kg/m³ (17%) increase in input water productivity above the control was achieved by the 160/Kc mm treatment. Delaying the application of continuous flooding in the second year greatly extended the period of crop growth suggesting the need for earlier sowing (by 7-10 days) to ensure pollen microspore still occurs at the best time to minimise yield loss due to cold damage. Nitrogen fertiliser management is an important issue when delaying continuous flooding, and nitrogen losses appeared to increase with the frequency of irrigation prior to continuous flooding. This was likely due to increased denitrification from alternate wetting and drying of the soil. Further research is required to determine the most appropriate nitrogen management strategies, and to also better define the optimal pre-flood irrigation frequency.     

Using automated monitoring systems to uncover pest population dynamics in agricultural fields

Understanding pest population dynamics is an essential part of pest management programs, but the examination of field pest populations faces many logistical difficulties. Consequently, potentially useful characteristics of pest ecology that can be utilized in the development of pest control strategies are yet to be discovered. In this study, we used an automated pest monitoring system to study a population of the oriental fruit fly and revealed its intriguing population dynamics in the field. The system automatically counts the number of flies captured by traps, and the real-time data are accessible anywhere using the Internet. Data from two time periods (May–June and July–August) were analyzed. Autocorrelation analysis indicated that there was a statistically significant population cycle in May and June, but the population was stationary in July and August. Partial rate correlation analysis and an associated functional analysis revealed the existence of delayed density-dependence that differed between the two periods. These results suggest that the mechanism of population dynamics may change possibly within a short time frame. These patterns were revealed because of the detailed data that were made available by the monitoring system and were unknown prior to the study. The automated monitoring system will be highly valuable for the advancement of pest monitoring and pest management programs.     

运用延迟反馈消除混沌的分析

以永磁电动机模型为例,研究如何运用延迟反馈来控制混沌。首先在理论上分析永磁电动机模型延迟反馈控制混沌的可行性,然后通过仿真实验验证其正确性。通过研究可知运用延迟反馈可以很好地消除混沌使系统达到一个稳定的状态。     

A wireless sensor network for precision viticulture: The NAV system

In the last decade, wireless technologies have been increasingly applied in precision agriculture. Wireless monitoring systems in particular have been used in precision viticulture in order to understand vineyard variability, and therefore suggest appropriate management practices for improving the quality of the wines.The NAV (Network Avanzato per il Vigneto – Advanced Vineyard Network) system is a wireless sensor network designed and developed with the aim of remote real-time monitoring and collecting of micro-meteorological parameters in a vineyard. The system includes a base agrometeorological station (Master Unit) and a series of peripheral wireless nodes (Slave Units) located in the vineyard. The Master Unit is a typical single point monitoring station placed outside the vineyard in a representative site to collect agrometeorological data. It utilizes a wireless technology for data communication and transmission with the Slave Units and remote central server. The Slave Units are multiple stations placed in the vineyard and equipped with agrometeorological sensors for site-specific environmental monitoring, which store and transmit data to the Master Unit. Software was developed for setup and configuration functionality. A graphical user interface operating on the remote central server was implemented to collect and process data and provide real-time control. The devices were tested in a three-step process: hardware functionality and data acquisition, energy consumption and communication. The NAV system is a complete monitoring system that gave flexibility for planning and installation, which fully responded to the objectives of the work in terms of energy efficiency and performance.     

Delayed permanent water rice production systems do not improve the recovery of 15N-urea compared to continuously flooded systems

Crop recovery of nitrogen (N) fertiliser in flooded rice systems is low relative to fertiliser N recoveries in aerobic crops, and the N losses have environmental consequences. Recent water shortages across the globe have seen a move towards alternative water management strategies such as delayed permanent water (DPW, also known as delayed flood). To investigate whether N fertiliser regimes used in DPW systems result in greater recovery of N fertiliser than traditional continuously flooded (CF) rice systems, we conducted a multi-N rate field trial using ¹⁵N-labelled urea. Around 27% of the ¹⁵N-labelled fertiliser was recovered in aboveground biomass at maturity, regardless of water regime or N fertiliser rate, and approximately 20% recovered in the soil to 300 mm depth. Plants in the CF system accumulated more total N at each rate of applied N fertiliser than plants in the DPW system due to greater exploitation of native soil N reserves, presumably because the earlier application of N fertiliser in the CF systems led to greater early growth and higher crop N demand. The greater crop biomass production as a result of higher N uptake in the CF system did not increase grain yields above those observed in the DPW system, likely due to cold weather damage. In the following season at the same site, a single N rate (150 kg N ha⁻¹) trial found no significant differences in crop N uptake, biomass yields, grain yields or ¹⁵N-labelled urea recovery in DPW, CF and drill sown-CF (DS-CF) treatments. However, owing to higher ¹⁵N fertiliser recovery in the 0–100 mm soil horizon, total plant + soil recovery of ¹⁵N was significantly higher in the CF treatment (63%) than the DS-CF and DPW treatments (around 50% recoveries). The loss of 40–50% of the applied N (presumably as NH₃ or N₂) in both seasons regardless of watering regime suggests that new fertiliser N management strategies beyond optimising the rate and timing of urea application are needed, particularly in light of increasing N fertiliser prices.     

棉花延迟吐絮收桃增产与机采收桃的可行性研究

为探寻棉花增产和机械化摘桃采收新方式的可行性,以开辟新的收获途径来实现棉花增产和全程机械化。在总结前人研究成果的基础上,进行了棉花延迟吐絮方法的试验。结果表明,棉铃在50~55天左右干物质重达到最大,后期吐絮反而会因消耗使重量降低,通过生长调节剂实现了棉花的延迟吐絮,棉花吐絮时间延迟5~10天,并获得了该方式下棉花增产的理论基础和依据。由此得出,棉花延迟吐絮实现增产是有据可依的,奠定了机械化摘桃的研究基础,为最终实现棉花收获全程机械化提供了研究参考。