Effective use of a reservoir for paddy irrigation in tropical monsoon Asia—a case study of the Ngamoeyeik Project,Lower Myanmar

Irrigation projects with reservoirs have contributed to the stabilization of traditional rainfed rice and to the introduction of double-rice in monsoon Asia. This type of irrigation also has the capability of shifting the traditional rice-cropping season. This paper discusses the influences of the shifted cropping season on water resources and the effective use of the reservoir in the Ngamoeyeik Irrigation Project Area in Lower Myanmar. Synthesized streamflow data were applied to simulate water storage in the reservoir. The main results are as follows: (1) shifting the cropping season to avoid inundation problems can increase water availability, (2) the amount of evaporation loss in the reservoir water budget can be as high as 16%, which decreases water efficiency in the reservoir operation during the dry season, (3) a shifted cropping season is preferable under the special hydrological conditions found in Lower Myanmar.     

Decadal changes in the rice-cropping system in the Ayeyarwady Delta using a large archive of satellite imagery from 1981 to 2020

In the last 40 years, the rice-cropping system has considerably changed in the Ayeyarwady Delta. The large archive of satellite imagery provides a history of how land and water resource managements have changed in the face of growing populations, resource demand, and climate change. This study aimed to assess the decadal changes in the rice-cropping system in the Ayeyarwady Delta by using the large archive of satellite imagery for the last 40 years (1981???2020). The long-term NDVI dataset provided various information on rice cultivation. Signal processing techniques were used to detect on the historical changes in the rice-cropping system, and the impact of climate change was assessed by using trend analysis. Until the 1980s, single-cropping of summer rice was dominant in the Delta. To enhance the grain yield of rice, the irrigation facilities were introduced in 1992 under an initiative of the Myanmar government. As a result, the annual cropping intensities increased from 1.087?±?0.390 in the 1980s to 1.422?±?0.499 in the 2010s. The information on historical change in the rice-cropping system would be useful to consider the practical and cost-effective utilization of remaining land and water resources. Moreover, the trend analysis of NDVI time-series showed negative trends in coastal areas. This indicates that the rice production in coastal areas has been constrained by the saline intrusion. The salt-affected areas are expected to expand under future climate change scenarios. Government support is highly required for sustainable rice production in the Delta.

     

Monitoring saline intrusion in the Ayeyarwady Delta,Myanmar, using data from the Sentinel-2 satellite mission

Paddy and Water Environment - Summer rice cannot be grown near the coast of the Ayeyarwady Delta, Myanmar, because of the high salinity in river water during the dry season. This means that saline...     

Biomechanical energy harvesting: generating electricity during walking with minimal user effort

We have developed a biomechanical energy harvester that generates electricity during human walking with little extra effort. Unlike conventional human-powered generators that use positive muscle work, our technology assists muscles in performing negative work, analogous to regenerative braking in hybrid cars, where energy normally dissipated during braking drives a generator instead. The energy harvester mounts at the knee and selectively engages power generation at the end of the swing phase, thus assisting deceleration of the joint. Test subjects walking with one device on each leg produced an average of 5 watts of electricity, which is about 10 times that of shoe-mounted devices. The cost of harvesting-the additional metabolic power required to produce 1 watt of electricity-is less than one-eighth of that for conventional human power generation. Producing substantial electricity with little extra effort makes this method well-suited for charging powered prosthetic limbs and other portable medical devices.     

棉铃虫四个丝氨酸蛋白酶抑制剂基因的克隆与表达分析

为明确棉铃虫Helicoverpa armigera丝氨酸蛋白酶抑制剂（serine protease inhibitor,serpin）的种类及其表达特性,利用PCR技术克隆棉铃虫的serpin基因,使用生物信息学软件预测其结构并进行系统进化分析,采用实时荧光定量PCR（real time quantitative PCR,RT-qPCR）技术比较serpin基因在棉铃虫不同发育阶段和组织中的表达量及取食Cry1Ac后其表达量的变化。结果表明,共获得serpin-a、serpin-b、serpin-c、serpin-e四个棉铃虫serpin基因,全长为1 119~1 254 bp,编码373~418个氨基酸,均包含一段具有反应中心环的保守结构域,且与斜纹夜蛾Spodoptera litura、草地贪夜蛾S.frugiperda等鳞翅目昆虫serpin的同源性较高。serpin-a和serpin-e在棉铃虫4龄幼虫期的表达量最高,serpin-b和serpin-c分别在成虫期和蛹期表达量最高。serpin-a在中肠和围食膜中表达量最高,serpin-b在头、中肠和表皮中表达量最高,serpin-c在头部表达量最高,serpin-e在中肠和血淋巴中的表达量显著高于其他组织。棉铃虫取食低浓度Cry1Ac后,中肠的serpin-b和serpin-e的表达量显著增加。推测不同serpin基因在棉铃虫不同发育时期和组织中可能发挥不同的作用,其中serpin-b和serpin-e可能参与棉铃虫对Cry1Ac的解毒过程。     

Nitrogenous compounds enhance the growth of petunia and reprogram biochemical changes against the adverse effect of salinity

This study aimed to determine ways to improve the growth and salt tolerance of petunia. Effects of polyamines (PAs; spermidine [Spd], spermine [Spm], and putrescine [Put]) and a nitric oxide (NO) donor (sodium nitroprusside [SNP]) were investigated. Initially, we screened petunia cultivars against sodium chloride (0–125 mM). The petunia cultivar Hurrah Red was identified as salt-sensitive cultivar in the basis of salt-effect on seed germination, fresh weight, and root length of seedlings. Treatment of Hurrah Red shoots with nitrogenous compounds improved the number, length, and fresh weight of roots, as well as the length and fresh weight of shoots over those of the control. Furthermore, plantlets rooted in an optimal concentration of Spd (34.5 µM), Spm (24.8 µM), Put (62.1 µM), and SNP (3.9 µM) were treated with 200 mM NaCl for 3 days to assess their tolerance level. Salt-affected plantlets showed higher level of lipid peroxidation, reduced catalase (CAT), peroxidase (POD), polyphenol oxidase (PPO) activities and decreased contents of photosynthetic pigments and polyphenol than those of the control. PAs and SNP treatments significantly elevated photosynthetic pigments, enhanced antioxidant enzymes, and decreased lipid peroxidation in salt-stressed plantlets. Moreover, the growth and salt-tolerance response of petunia was highest when plantlets were exposed to SNP, followed by levels on treatment with Put, Spm, and Spd. Thus, the findings of this study suggested that treatment with exogenous SNP, Put, Spm, and Spd could protect petunia plants against soil salinity and improve their commercial production.     

Characteristics of Livestock Husbandry and Management Practice in the Central Dry Zone of Myanmar

Tropical Animal Health and Production - The central dry zone of Myanmar is the area with the highest density of small-scale livestock farmers under harsh environmental condition. In this study, we...     

Effect of replacements of fishmeal and fish oil on growth and dioxin contents of rainbow trout

Eight experimental diets were prepared to determine the effect of replacements of fishmeal and fish oil with plant protein and palm oil on the growth and dioxin contents in rainbow trout. The first four diets (FP0, FP5, FP10, and FP15) included fishmeal (55%) with increasing replacement of fish oil by palm oil (0, 5, 10, and 15%). Four other diets (AP0, AP5, AP10, and AP15) were substituted with an alternative protein source and with increasing palm oil content (0, 5, 10, and 15%). Dietary dioxin contents increased as fish oil level increased. Thirty rainbow trout (mean weight 38 g) were fed the experimental diets for 12 weeks. No significant differences in growth performance and feed utilization were observed. Dietary dioxin contents influenced the dioxin contents in the whole body. These results suggest that palm oil could effectively replace fish oil in rainbow trout diets, and reduce the dioxin contents in fish.     

Assessment of paddy fields’ damage caused by Cyclone Nargis using MODIS time-series images (2004–2013)

Paddy and Water Environment - The Ayeyarwady Delta in the Bay of Bengal, the rice bowl of Myanmar, depends on natural conditions, especially rainfall. During the dry season, the delta’s...