A PRELIMINARY STUDY ON THE MODEL OF DEVELOPMENTAL RATE OF RICE

The relationship between the developmental rate of crops and meteorological factors is not only a fundamental theory of agrometeorology, but also the foundation of agroclimatic division and agrometeorological forecasting as well. Therefore, some studies have been made on this by scientific workers at home and abroad. This paper provides a further approach to this subject on the basis of comparatively integral data.

薄荷醇对果蝇产卵驱避作用及毒杀效果

【目的】研究薄荷醇对常见几种果蝇Drosophila产卵的驱避作用,并通过后代存活率和发育历期及成虫死亡率以评价薄荷醇毒杀作用。【方法】应用产卵双向选择装置,在0.05%,0.1%和0.2%薄荷醇作用下检测果蝇的产卵选择性;利用双染料食物偏好实验检测薄荷醇对果蝇的摄食行为影响;利用产卵装置,检测薄荷醇对黑腹果蝇D.melanogaster的位置的影响;利用黑暗条件、摘除触角和前腿以及Orco 2突变体测定薄荷醇对黑腹果蝇产卵选择性的影响;并测定薄荷醇对黑腹果蝇后代存活率与发育历期的影响;测定薄荷醇对黑腹果蝇成虫寿命、奔跑速度和攀爬速度的影响;利用二氢乙锭(dihydroethidium,DHE)荧光染色技术,评估喂食1%薄荷醇3 d后黑腹果蝇成虫肠道内活性氧(reactive oxygen species,ROS)水平。【结果】薄荷醇对果蝇雌成虫产卵有驱避性,在0.05%,0.1%和0.2%薄荷醇作用下黑腹果蝇雌成虫的产卵指数分别为-0.42,-0.58和-0.98;铃木氏果蝇D.suzukii、雅库巴果蝇D.yakuba和拟暗果蝇D.pseudoobscura雌成虫对薄荷醇的产卵避性反应与黑腹果蝇雌成虫相同。在摄食过程中,黑腹果蝇及铃木氏果蝇成虫均对薄荷醇培养基产生明显排斥反应。薄荷醇培养基对黑腹果蝇成虫有明显的位置驱避性,0.05%,0.1%和0.2%薄荷醇处理下位置指数分别为-0.32,-0.44和-0.84。各个浓度的薄荷醇对黑暗环境和摘除前足的黑腹果蝇雌成虫仍然表现出显著的产卵驱避性,但在摘除黑腹果蝇成虫触角的条件下,薄荷醇对它们的产卵驱避性显著降低,0.05%,0.1%和0.2%薄荷醇作用下产卵指数分别为-0.04,-0.06和-0.26,薄荷醇对Orco 2突变体仍旧有产卵驱避性。与对照组相比,1%薄荷醇处理组黑腹果蝇成蛹和成虫羽化时间明显延长,分别延长了0.74和0.73 d,存活率明显下降,分别下降了63.2%和91.3%。随着薄荷醇浓度的增加黑腹果蝇成虫存活率呈现下降的趋势,且明显降低其奔跑和攀爬速度,即薄荷醇降低了亲代黑腹果蝇的适合度。1%薄荷醇处理3 d显著提升了黑腹果蝇成虫肠道内的ROS水平。【结论】薄荷醇通过嗅觉介导了果蝇的产卵避性反应,且薄荷醇降低了后代和亲代的适合度和存活率。

不同桑树品种对桑螟侵害的抵抗能力调查与分析

桑螟(Glyphodespyloalis Walker)是严重危害桑树的主要害虫之一,一旦暴发成灾会给蚕桑生产造成重大经济损失。为了筛选出对桑螟侵害有较强抵抗能力的桑品种,在田间调查桑螟发生规律及对8个桑品种的危害率基础上,进一步在室内观察比较了桑螟分别取食8个桑品种的叶片后其生长发育受到的影响。田间调查结果显示,桑螟在重庆市北碚区一年中总共有5个成虫羽化高峰期,大致出现在4月21日、6月16日、8月中旬、9月中旬、10月20日;桑螟对桑品种塔桑、蒙桑、孟简3号、德昌长果、东光小白和沙漠果桑的危害率显著低于对火桑和葫芦桑的危害率。室内饲养观察获得的桑螟发育历期显示,取食不同桑品种的叶片后,桑螟的平均幼虫期经过时间开差较大,取食蒙桑(16.06d)、孟简3号(15.09d)和德昌长果(14.91d)叶片的平均幼虫期经过时间显著长于取食火桑(13.75d)、葫芦桑(13.80d)和沙漠果桑(14.03d)叶片的经过时间,对蛹期和成虫期经过时间的影响差异不显著,但取食孟简3号和蒙桑叶片后的化蛹率最低(58.33%),且羽化成虫的数量均低于31头。综上所述,孟简3号和蒙桑对桑螟的侵害具有一定的抵抗性,有进一步研究后筛选成为抗虫桑品种的潜力。

Relationship between energy dissipation rate and channel morphology in the development of the model braided channel

A certain pattern of channel is the product of its self-adjustment under given boundary, discharge and sediment conditions. Based upon the principle of process-response model, an experimental study with 18 runs is carried out in LESRC. This paper is focused on the variation of the energy dissipation versus the channel morphology during and after the bedmaking process of braided channel. The results show that there exists a good empirical relationship between the energy dissipation rate and channel morphology. According to this relationship and the theory of minimum rate of energy dissipation, the authors explain the metamorphosis of the model channel with the development of the braided river.

Impacts of climate change on development rate and production of corn in the northeastern China

In this paper, the impacts of climate change on development rate and production of corn in the northeastern China are discussed. The results show that the higher the temperature is, the faster the development rate will be. And the more the precipitation is, the slower the development rate will be. Of which, air temperature is the controlling factor of corn development rate. The influences of development rate on corn yield are remarkable. The impacts of development rate on production in first and last periods are great, and small in the middle two periods. The development rate is positive by relate with corn production from sowing to emergence stage and negative during other periods. So, it is very important to arrange a suitable sowing time for com cultivating in the northeastern China.

Strategic Considerations on Development of WiMAX and Its Relationship with 3G and 4G

The paper states the characteristics and basic market positioning of WiMAX. It should be noted that WiMax is a new generation WMAN (Wideband MAN) broadband wireless access standard with good forward extensibility. It is emphasized that the basic market positioning of WiMAX should be nothing but WMAN applications. It is predicted that the applications of WiMax would face severe challenges mainly due to its high cost, at least at the initial stage. Finally the paper gives all-around analysis on the relationship between Wi-Fi, WiMAX, WBMA, 3G, 3G+ and 4G.

Development rate of Labidocera euchaeta Giesbrecht in Xiamen Harbor

-The development rate of Labidocera euchaeta Giesbrecht in the Xiamen Harbor was studied in laboratory. The results showed that the development times of egg and larval stages ( D ) were significantly correlated with temperature ( T ), following the Belehradek function, D = α( T -7. 5)-1.0634. The development time from egg to larval stages and adult, as well as generation time can be predicted from the equation for egg development ( α=411/24) by appropriately multipling the constant (α) with a proportion. The development was not isochronal over the whole larval period. Durations of naupliar stages were short and quasi-isochronal, which favored their non-feeding development. In contrast, durations of copepodid stages (C) were long. CV had the longest duration followed by CI, both of which are considered as the critical stages in the larval development. The acclimation effect of the seasonal temperature on the development rate was also observed.

Effect of Strain Rate on Compression Behavior of Vinyl Ester Resin Casting

Quasi-static and high strain rate compressive experiments on vinyl ester casting were carried out by means of MTS (Material Test System) and Hopkinson bar. The behaviors of the compressed unstable and fracture of the resin casting at different strain rates were investigated.The results indicate that the response behavior of the resin casting is controlled by different mechanisms at different strain rate, and some mechanical properties of vinyl ester casting are rate-dependent: the casting are destroyed in toughness model under strain rate 3.3×10 -4～6.6×10 -3/s, while the casting are destroyed in brittleness model under strain rate 950～5800/s. The yield stress, yield strain energy density are all increased with the increasing strain rates at quasi-static as well as at high strain rates. What is interesting is that the yield strain decreased with the strain rates increasing at quasi-static while increased at high strain rates. It is considered that the casting occurred forcing high elastic deformation at high strain rates. The damage of the specimens is mainly controlled by axial stress before unstable deformation, while mainly controlled by shear stress after unstable deformation, and then developed to fracture finally. This progress is rate-dependent: the development of the cracks inside the castings increased with the strain rate increasing.

Effects of Bovine Embryos at Different Developmental Stages on Bisection Effect

[Objectives]This study was conducted to explore the effects of embryos at different developmental stages on the bisection effect of embryos,improve the efficiency of bovine embryo bisection,and facilitate the application of embryo bisection technology in cattle breeding.[Methods]The effects of two different bisection solutions on the bisection of morulae and blastocysts in vitro were explored.The morulae and blastocysts produced in vitro from cattle that developed to the 6th to 8th d were bisected by hands,and demi-embryos were cultured in vitro.Their development was observed.[Results]Morulae were bisected in PBS solution and PBS+0.2 mol/L sucrose,and the success rates of bisection were 50%and 95.2%,respectively.The success rate of bisecting morulae in PBS+0.2 mol/L sucrose was significantly higher than that in PBS(P<0.05),while the development rate of the bisected demi-embryos had no significant difference between the two(53.3%,52.4%)(P>0.05).The success rates of blastocyst bisection in PBS solution and PBS+0.2 mol/L sucrose were 51.6%and 95.1%,respectively.The success rate of blastocyst bisection in PBS+0.2 mol/L sucrose was significantly higher than that in PBS(P<0.05),while the development rate of the bisected demi-embryos had no significant difference between the two(50.0%,56.4%)(P>0.05).[Conclusions]There were no significant differences between the success rates of bisecting bovine morulae and blastocysts in PBS+0.2 mol/L sucrose,which were both significantly better than those in pure PBS bisection solution,proving that PBS+0.2 mol/L sucrose bisection solution is suitable for bovine embryo bisection.

Spatiotemporal variations in the organic carbon accumulation rate in mangrove sediments from the Yingluo Bay,China,since 1900

Mangroves can not only provide multiple ecosystem service functions,but are also efficient carbon producers,capturers,and sinks.The estimation of the organic carbon accumulation rate(OCAR)in mangrove sediments is fundamental for elucidating the role of mangroves in the global carbon budget.In particular,understanding the past changes in the OCAR in mangrove sediments is vital for predicting the future role of mangroves in the rapidly changing environment.In this study,three dated sediment cores from interior and fringe of mangroves in the Yingluo Bay,China,were used to reconstruct the spatiotemporal variations of the calculated OCAR since 1900 in this area.The increasing OCAR in the mangrove interior was attributed to mangrove flourishment induced by climate change characterized by the rising temperature.However,in the mangrove fringe,the strengthening hydrodynamic conditions under the sea level rise were responsible for the decreasing OCAR,particularly after the1940 s.Furthermore,the duration of inundation by seawater was the primary factors controlling the spatial variability of the OCAR from the mangrove fringe to interior,while the strengthened hydrodynamic conditions after the 1940 s broke this original pattern.

Development of River Rating Curves for Simple to Complex Hydraulic Structure Based on Calibrated HEC-RAS Hydraulic Model, in Kwale, Coastal Kenya

Accurate and reliable river flow information is critical to planning and management for sustainable water resources utilization. Most of engineering activities related to hydrologic designs, flood, drought, reservoirs and their operations are heavily dependent on the river flow information derived from river rating curve. The rating curve for a given river section is normally developed from a set of direct stage-discharge measurements for different periods. This involves considerable labour, risk and resources, and presupposes a complex and extensive measuring survey. Extrapolating the rating curve beyond the measured range, as common in many cases, is fraught with errors and uncertainties, due to the complex hydraulic behaviour of the surface water profile in transition from section, channel, downstream and flood plain controls which are often poorly understood with direct measurements. Hydraulic modeling has recently emerged as one of the more promising methods to efficiently develop accurate rating curves for a river section with simple or complex hydraulic structures and conditions. This paper explores the use of a Hydraulic Engineering Center-River Analysis System (HEC-RAS) model to review and develop river rating curves for three hydrometric stations on two rivers in Kwale, coastal Kenya. The HEC-RAS models were set up based on topographical (cross section and longitudinal) survey data for the reaches and engineering drawings for the hydraulic structures commonly used as section controls for flow measurement. The model was calibrated under unsteady state conditions against measured stage-discharge data which were captured using a Velocity Current Meter (Valeport) and an Acoustic Doppler Current Profiler (ADCP) for both low and high flow. The rating curves were extracted from model results and the uncertainty associated with each rating curve analyzed. The results obtained by the HEC-RAS model were satisfactory and deemed acceptable for predicting discharge across the stage range at each river section.

Chinese medicine practitioner turnover rate and the development of Chinese medicine in Hong Kong,China

Objective:To establish that the Hong Kong Special Administrative Region(HKSAR)government is actively promoting Chinese medicine(CM)and to examine turnover rate of Chinese medicine practitioners(CMPs)in Hong Kong,China in light of this governmental push.Methods:This study covered two major areas:reviewing CM development in Hong Kong,and assessing the turnover rate of CMPs in Hong Kong.The first part of the paper is a historical review.The investigation of turnover rate had two sections.Section 1,quantitative method,involved online questionnaires;Section 2,qualitative method comprised interviews with CMPs from different types of CM clinics to ascertain the reasons for the turnover among CMPs.Results:A total of 123 online questionnaires were received in Section 1(55 from male CMPs;66 from female CMPs;2 respondents were unwilling to disclose their sex).The proportion of CMPs who had resigned in 2018e19 was 22.8%(28),of whom 5.7%(7)had resigned twice in one year.The rates of resignation in 3 years and 5 years were up to 40.7%(50)and 56.9%(70),respectively.Six CMPs were interviewed in Section 2.Young CMPs were more likely to resign than seniors.The large gap between actual salary and expectations appeared to be the main reason for the high rate of resignation.Conclusion:HKSAR government keenly desires to promote CM in Hong Kong,however,high turnover rate of CMPs was detected even under this positive governmental support.There is an urgent need to conduct a more representative study of the reasons for the inclination of CMPs in Hong Kong.The study highlights an important issue in CM development,and these results should remind different stakeholders in the CM industry and the government that CMPs need better career prospects and support in various areas.

National Breast Cancer Mortality and Incidence Rates According to the Human Development Index: An Ecological Study

Background: This study aimed to identify the role of human development index (HDI) in the incidence and mortality rates of breast cancer (BC) worldwide. Methods: Data on the age-standardized incidence and mortality rates of BC for 184 countries were obtained from the GLOBOCAN. Data about the HDI and other indices were obtained from the World Bank Report 2013. Linear regression model was used for assessment the effect of HDI on BC occurrence rates. Results: In 2012, BCs were estimated to have affected a total of 1,671,149 individuals (crude rate: 47.8 per 100,000 individuals), and caused 521,907 deaths worldwide (crude rate: 14.7 per 100,000 individuals). Nearly half of total female BC cases (46.3%) with the highest risk of incidence (age-standardized Rate (ASR): 128 per 100,000) had occurred in very high HDI regions. The most proportion of the mortality burden was in low HDI and medium HDI areas. Linear regression analyses showed a direct significant correlation between the incidence of BC and HDI at the global level (B = 104.5, P < 0.001). The mortality rate of BC was not significantly associated with HDI (B = 3.26, P = 0.160). Conclusion: Our study showed that the burden of female BC is enormous in very high HDI and low HID regions. Targeted interventions have the ability to reduce this number significantly through resource-dependent interventions. Moreover, further reductions in mortality could be brought about by increasing access to curative treatment for patients with BC.

Development of Heart Rate Variaty in the Early and Rehabilitation Phase of AMI

Heart rate variaty (HRV) of 85cases with AMI was observed in the early phase after onset and rehabilitation phase at first month and sixth month, and was contrasted with six time threshold indices of 111 cases with coronary heart disease and that of 35 normal control. We found the HRV of AMI was apperantly lower in the acute phase than that of coronary heart disease and normal controls. HRV recovered gradually with inclining to be stable after half a year, but it was still lower than that of controls. Low HRV in early phase of AMI suggested the poor prognosis.

锈斑蟳人工育苗技术

以锈斑蟳(Charybdis feriatus)为研究对象,将锈斑蟳发育阶段分为T1、T2、T3、T4、T5、T6及M期7个阶段进行锈斑蟳人工育苗试验。结果表明,①从蟹苗平均阶段存活率来看,秋季和春季育苗存活率最高是T1期,为100%;存活率最低是幼体发育阶段,为42.5%;其次是大眼幼体阶段,为51.1%,在锈斑蟳育苗过程中,T6期变态为大眼幼体以及大眼幼体变态为Ⅰ期幼蟹是最重要的时期。②锈斑蟳到T3期蟹苗在春季和秋季的总体存活率为48.1%,T6期变态为大眼幼体时期的总体存活率为11.4%,最后发育成为I期幼蟹的育苗总体存活率为5.0%。

温度对红肩瓢虫Harmonia dimidiate Fabricius生长发育的影响

【目的】研究温度对红肩瓢虫(Harmonia dimidiate Fabricius)生长发育的影响,探讨其大量扩繁及生防应用的适宜温度。【方法】以地中海粉螟(Ephestia kuehniella Zeller)卵为饲料,设置15、20、25、30和32℃等5个温度处理,研究温度对红肩瓢虫各阶段发育历期及存活率影响,采用最小二乘法测算红肩瓢虫各发育阶段的发育起点温度和有效积温,采用线性日度方程模拟温度与红肩瓢虫发育速率间的关系。【结果】20~30℃的温度范围适于红肩瓢虫卵的孵化,孵化率均达85%以上;发育至成虫的总存活率以20℃时最高,达87.50%,其次为25℃(82.50%)>30℃(77.50%)>32℃(45.00%)>15℃(35.00%),可见15℃低温和32℃高温均不适宜红肩瓢虫存活。15~32℃范围内,红肩瓢虫均可完成发育,温度升高发育速率加快、发育历期缩短,20~32℃区间内各处理间的总发育历期均无显著性差异,而15℃时极显著长于其他温度处理,说明15℃低温不适宜红肩瓢虫生长发育。红肩瓢虫各发育阶段中,2龄幼虫的发育起点温度最高,为12.74℃,蛹期最低,为9.24℃,从卵至成虫整个发育历期的发育起点温度和有效积温分别为9.87℃和324.82日·度。【结论】综合存活率与发育历期,以地中海粉螟卵为饲料,20~30℃为红肩瓢虫生长发育的适宜温度,本研究结果为红肩瓢虫的大量扩繁和生防应用条件提供了参考,发育起点温度和有效积温的测算也为红肩瓢虫的滞育研究提供了依据。

光周期对井上蛀果斑螟生长发育及繁殖的影响

为明确不同光周期对井上蛀果斑螟Assara inouei Yamanaka生长发育及繁殖的影响,在25℃,70%RH,光照强度5500 lx及5种不同光周期(L∥D=8 h∥16 h、10 h∥14 h、12 h∥12 h、14 h∥10 h、16 h∥8 h)条件下,研究了井上蛀果斑螟的生长发育和繁殖情况。结果表明,光周期对井上蛀果斑螟幼虫和蛹的发育历期、幼虫存活率、化蛹率、羽化率、成虫寿命、产卵期、平均单雌产卵量有显著影响。在L∥D=16 h∥8 h光周期下幼虫期、蛹期和产卵期最短,分别为18.8、8.2 d和7.8 d;幼虫存活率、化蛹率、羽化率和平均单雌产卵量最高,分别为67.4%、86.5%、93.3%和95.3粒。在L∥D=12 h∥12 h光周期下雌、雄成虫寿命和产卵期最长,分别为15.8、15.1 d和12.5 d,但幼虫存活率最低,为38.9%。光周期对蛹重、成虫产卵前期和卵孵化率无显著影响。除L∥D=16 h∥8 h光周期外,其余4种光周期下井上蛀果斑螟幼虫部分个体出现生长发育停滞现象,滞育率在3.9%~6.9%之间。长光照有利于井上蛀果斑螟的生长发育及繁殖。

橘小实蝇和番石榴实蝇幼虫之间的竞争机制

为了明确橘小实蝇Bactrocera dorsalis(Hendel)和番石榴实蝇Bactrocera correcta(Bezzi)资源利用的种间竞争机制,比较两者的竞争实力,本文研究了两种实蝇幼虫在26℃条件下于人工饲料和番石榴中的种间竞争关系。结果显示,两种实蝇同龄幼虫在共同饲养的竞争条件下,橘小实蝇幼虫期缩短、存活率提高,而番石榴实蝇蛹重变轻、存活率降低,橘小实蝇通过加快自身生长和抑制番石榴实蝇生长的方式在资源利用竞争中获得更多资源。因此,两种实蝇幼虫在种间竞争中,橘小实蝇可通过调整生活史对策获得竞争优势。