A strain-specific and a sex-associated STS marker for Asian arowana (Scleropages formosus, Osteoglossidae)

A sex‐associated amplified fragment length polymorphism and a strain‐specific random amplified polymorphic DNA marker were identified from Asian arowana (dragonfish; Scleropages formosus Müller & Schlegel) by screening pooled genomic DNA samples from three different strains as well as males and females respectively. Both markers were cloned, sequenced and successfully converted into sequence‐tagged‐site (STS) markers. The strain‐specific STS marker could be applied to differentiate the Indonesian golden strain of Asian arowana from the green and blood‐red strains before the stage when colours become identifiable. Individuals from the green strain could be sexed with an efficiency of 82.7% using the sex‐associated STS marker. Thus, populations with preferred sex ratios can be formed without the need of rearing a large number of fish.     

Evidence for large decadal variability in the tropical mean radiative energy budget

It is widely assumed that variations in Earth's radiative energy budget at large time and space scales are small. We present new evidence from a compilation of over two decades of accurate satellite data that the top-of-atmosphere (TOA) tropical radiative energy budget is much more dynamic and variable than previously thought. Results indicate that the radiation budget changes are caused by changes in tropical mean cloudiness. The results of several current climate model simulations fail to predict this large observed variation in tropical energy budget. The missing variability in the models highlights the critical need to improve cloud modeling in the tropics so that prediction of tropical climate on interannual and decadal time scales can be improved.     

Human CSF-1: molecular cloning and expression of 4-kb cDNA encoding the human urinary protein

A 4-kilobase complementary DNA (cDNA) encoding human macrophage-specific colony-stimulating factor (CSF-1) was isolated. When introduced into mammalian cells, this cDNA directs the expression of CSF-1 that is structurally and functionally indistinguishable from the natural human urinary CSF-1. Direct structural analysis of both the recombinant CSF-1 and the purified human urinary protein revealed that these species contain a sequence of at least 40 amino acids at their carboxyl termini which are not found in the coding region of a 1.6-kilobase CSF-1 cDNA that was previously described. These results demonstrate that the human CSF-1 gene can be expressed to yield at least two different messenger RNA species that encode distinct but related forms of CSF-1.     

Nudging fisheries and aquaculture research towards food systems

Food system is a powerful concept for understanding and responding to nutrition and sustainability challenges. Food systems integrate social, economic, environmental and health aspects of food production through to consumption. Aquatic foods are an essential part of food systems providing an accessible source of nutrition for millions of people. Yet, it is unclear to what degree research across diverse disciplines concerning aquatic foods has engaged food systems, and the value this concept has added. We conducted a systematic review of fisheries, aquaculture and aquatic food literature (2017–2019) to determine the following: the characteristics of this research; the food systems components and interrelations with which research engaged; and the insights generated on nutrition, justice, sustainability and climate change. Sixty five of the 88 reviewed articles focussed on production and supply chains, with 23 considering human nutrition. Only 13% of studies examined low- and middle-income countries that are most vulnerable to undernutrition. One third of articles looked beyond finfish to other aquatic foods, which illuminated values of local knowledge systems and diverse foods for nutrition. When aggregated, reviewed articles examined the full range of food system drivers—biophysical and environmental (34%), demographic (24%) and socio-cultural (27%)—but rarely examined interactions between drivers. Future research that examines a diversity of species in diets, system-wide flows of nutrients, trade-offs amongst objectives, and the nutritional needs of vulnerable social groups would be nudging closer to the ambitions of the food systems concept, which is necessary to address the global challenges of equity, nutrition and sustainability.     

Co-inoculation of Acacia mangium with Glomus intraradices and Bradyrhizobium sp. in aeroponic culture

Acacia mangium grown in aeroponic culture was co-inoculated with selected strains of Bradyrhizobium sp. and Glomus intraradices. A single-step technique using alginate as an embedding and sticking agent for an inoculum composed of arbuscular mycorrhiza (AM)-infected sheared roots was used to infect plants. This method resulted in the successful establishment of AM in 100% of the inoculated plants after 7 weeks. The results indicated that dual microbial inoculation with Glomus intraradices strain S-043 and Bradyrhizobium strain AUST 13C stimulated the growth of A. mangium in aeroponic culture. The effects of single and dual microbial inoculations were also evaluated at two levels of P in the nutrient medium. A concentration of 5 mg P kg^–1 stimulated the development of AM without affecting plant development or establishment of Bradyrhizobium symbiosis. In contrast, saplings supplemented with a higher concentration of P (25 mg kg^–1) alone or co-inoculated with Bradyrhizobium had lower AM frequencies.     

香港土壤研究 Ⅰ.研究现状与展望

对近半个世纪以来香港地区的土壤分类、农业和园林绿地土壤的肥力以及土壤环境保护等研究工作进行了系统的回顾和介绍,为中国香港地区及其他社会经济快速发展地区的土壤资源合理利用、生态环境保护与社会可持续发展提供了科学信息。认为,高度城市化和国际化的香港地区可以结合香港高科技及新产业的发展目标,合理利用和开发土地资源,定向培育中草药产地土壤环境与教育基地;需要进一步系统研究香港地区土壤发生与系统分类、性状与特征、空间分布与变异规律,建立香港土壤基础数据库、土壤图和土壤信息与服务系统;进一步探明污染元素和有益元素的土壤地球化学背景以及持久性有机污染物的环境生物地球化学过程及其生态与健康风险,建立长期的土壤环境质量动态观测点与研究平台,以及区域尺度的土壤环境质量信息系统和定量可视化预测预警系统;研究与发展适合香港地区的有问题土壤的风险评估与修复技术体系     

Effects of earthworm activity and P‐solubilizing bacteria on P availability in soil

The effects of phosphate solubilizing bacteria (Bacillus megateriumi) (PSB) and earthworms (Pheretima guillelmi and Eisenia fetida) on phosphorus (P) turnover and transformation in soil were investigated in a laboratory experiment lasting for 21 days. The treatments included soil + P. guillelmi (SW1), soil + E. fetida (SW2), soil + B. megaterium (SB), soil + P. guillelmi + B. megaterium (SBW1), soil + E. fetida + B. megaterium (SBW2), and the control with sterilized soil (control) only. The results showed that the number of B. megaterium. was enhanced in all treatments especially those with earthworms added when compared with the control. Activities of acid phosphatase (pH = 6.5) increased in all treatments, especially in the presence of P. guillelmi with or without PSB (64 % and 38 %, respectively). Significant increases in both inorganic P and water‐soluble P were observed in treatments involving B. megaterium. and earthworms when compared with the control. Inoculation of both earthworms and PSB had significant effects on microbial growth, enzymatic activity, and thus enhanced the release of available P. The dual inoculation of earthworms and bacteria further accelerated P transformation. Different performances observed for the earthworm species were probably due to their different feeding habits and physiology.     

Modelling sulphur dioxide levels in the Sarnia area

For environmental planning and policy-making purposes, this study was undertaken to apply the Ontario Ministry of the Environment Air Quality Model for SO₂ to an urban-industrial region, namely, the Sarnia and St. Clair River area. Predicted and measured SO₂ levels showed good agreement. A comparison of daily model predictions with 118 observations from 11 monitoring stations for 12 days in 1973 gave an overall correlation coefficient of 0.88.