Effects of heat‐assisted irradiation treatment on microbial and physicochemical qualities of dried laver (Porphyra spp.) and optimization by response surface methodology

The Korean Food Code has approved irradiation less than 7 kGy for microbial control in algal food, which is often not sufficient to achieve the acceptable contamination level (<10⁴ CFU/g). In this study, heat‐assisted low‐dose electron beam (E‐beam) irradiation was applied for improving the microbial quality of dried laver through the response surface optimization of process conditions (Xn); irradiation dose (0–4 kGy, X1), heating temperature (140–180°C, X2) and heating time (0–28 s, X3) for their effects on total aerobic bacteria (TAB) count, moisture content, chlorophyll content, carotenoid content and overall palatability of dried laver. TAB counts were affected more by irradiation dose than by heating temperature and time. Moisture, chlorophyll and carotenoid content and overall palatability were more affected by heating temperature and heating time than by irradiation dose. The overall results indicated that the optimal conditions were irradiation dose of 1.8–3.0 kGy, heating temperature of 154–170°C and heating time of 10–18 s to achieve appropriate quality attributes of heat‐assisted E‐beam irradiated dried laver, such as TAB count of 10³ CFU/g, moisture content of 5% and 6.5 of good overall palatability score out of 7.     

Thermal challenge of the Indian shrimp Penaeus indicus

This study investigated short‐term effects of increasing water temperature from 27 to 41°C on survival and feed consumption of Penaeus indicus at three different ages: PL₂₅ (postlarvae 25 days old), PL₅₀ and PL₉₀. For each age group, water temperature was maintained at 27°C in the control, but increased to 32, 35, 38 and 41°C at a rate of 1°C every eight hours. The temperature was then kept stable until the end of the 7‐day experiment. Results showed that increasing water temperature affected both survival and feed consumption of the experimental shrimps (p < .01). Survival was highest at 32 and 35°C ranging from 93.8% to 100%, but significantly reduced to 40.0%–81.6% at 38°C. No shrimp survived the 41°C treatment. PL₂₅ were more tolerant to 38–41°C than PL₅₀ and PL₉₀ in terms of survival. Increasing water temperature had no effects on feed consumption of PL₂₅ (p > .05). For PL₅₀ and PL_90, feed consumption significantly increased at 38 and 41°C (p < .01) and was similar within the range of 27–35°C. This study suggests that P. indicus in tropical areas can tolerate water temperatures of at least 35°C and should be considered for farming during the summer time.     

Dual-facing bridges and brokers: Diaspora politics and Chinese voluntary associations

This commentary introduces the term ‘dual facing’ to describe the way that Chinese voluntary associations orientate themselves as collectives situated between the ancestral land (China) and their countries of settlement. The commentary uses examples of Chinese voluntary associations in Singapore and Myanmar to reflect on China's longstanding presence and expanding reach in Southeast Asia, including through its diaspora engagement with the Chinese abroad. It argues that such associations are embedded not only in the nation-building efforts of their countries of settlement, but also the ancestral land. However, this dual-facing orientation also means that they can become embroiled in conflictual domestic and foreign politics at both ends, potentially jeopardising how they are otherwise seen as bridges and brokers by China and in the countries where have settled.     

First report on the isolation of immunoglobulin M of guppy, Poecilia reticulata, for the production of polyclonal antibodies

As guppies are one of the commercially important fish in freshwater ornamental aquaculture industry, it is important to gain an understanding of guppy immune response for infectious disease control. Till now, the number of study that examined the immune response of guppies is limited and effective tools for monitoring guppy antibody have not been reported. In this study, we successfully isolated guppy IgM using mannan-binding protein (MBP) affinity chromatography and produced specific polyclonal antibodies against guppy IgM heavy and light chains, that showed a molecular weight of approximately 74 and 23 kDa respectively. The produced polyclonal antibodies were used to develop an enzyme-linked immunosorbent assay (ELISA) and have demonstrated to be an effective tool for the detection and quantification of antigen-specific antibody of guppies immunized with Pseudomonas fluorescens. In conclusion, the produced anti-guppy IgM polyclonal antibodies should prove its future implications for immunology and epidemiology studies in guppies.     

台北市山坡地之开发特性与其对下游水文环境冲击之研究

本研究系针对台北都会区四周之山坡地,进行连续之地文与水理分析,目的在了解都市化山坡地之迳流特性,期就定量之研究分析,推估不同型态之土地利用及开发度,对下游水文环境所造成之冲击,并提出对应之建议。本研究首先建立台北市山坡地开发程度与其地文条件之评估模式,再配合於山沟谷口间设置水文环境监测站,以掌握山坡地之动态水文资料。经评估结果,本研究共规划设置六座水文环境监测站,对都市化山坡地之尖峰流量、稽延时间、泥砂产量、地下水位及水质变化进行长期监测。其监测资料,经验证分析之结果显示,当集水区不透水面积提高至40%时,其洪峰流量将提高2.7倍;同时亦发现当集水区不透水面积在5%以下时,其洪峰流量增加并不显着,但不透水面积提高至20%～40%范围之间时,其洪峰流量则有显着提升之现象。故於高度都市化集水区进行水理分析时,应特别考虑都市化现象对迳流机制之影响,同时该集水区之总开发度亦不宜超过30%,以避免对下游之水文环境造成冲击。     

Phylogeography and conservation gaps of Musa balbisiana Colla genetic diversity revealed by microsatellite markers

Genetic Resources and Crop Evolution - Collection and storage of crop wild relative (CWR) germplasm is crucial for preserving species genetic diversity and crop improvement. Nevertheless, much of...