In the study of vaccines for dengue viruses, which are multivalent immunization, genetically and antigenically distinct, we should have more sophisticated understanding of viral immune physiology. Because the immune response to dengue and its role in the pathophysiology of dengue fever and dengue hemorrhagic fever are multifaceted, several different efforts have been made to engineer a protective vaccine. Because of space limitations, this review is focused only on vaccines that have emerged from preclinical studies into clinical trial.
The enzymes of the acyl-coenzyme A: cholesterol acyltransferase (ACAT) family are responsible for the
Cyanobacteria possess multiple, functionally distinct NADPH dehydrogenase (NDH-1) complexes. In this mini-review, we describe the cyanobacterial NDH-1 complexes by focusing on their identification, regulatory properties, and multiple functions. The multiple functions can be divided into basic and extending functions, and the basic functions are compared with those in chloroplasts. Many questions related to cyanobacterial NDH-1 complexes remain unanswered and are briefly summarized here.
Algae and mosses are not only two of the familiar communities in the process of desert vegetational succession, but also have the highest biomass in biological soil crusts. Meanwhile, being the pioneer plants, algae and mosses are involved in the establishment of biological soil crusts, which have great importance in arid environments and play a major role in desert ecosystems, such as being the indicator of the vegetation type, soil-holding, preventing erosion by water and wind, and sand fixation. This paper reviews the advances in the study of algae and mosses in arid and semi-arid areas. It mainly describes the ecological functions of algae and mosses including their influences on water cycle, circulation of substances, and community succession. In addition, the relationships between algae and mosses are discussed. Finally, some suggestions are proposed for the research orientations of algae and mosses in biological soil crusts. Ecologically, algae and mosses have significant ecological importance in arid areas, especially in those areas where environmental problems are becoming increasingly serious.
Traditional agroecosystems play an important role in the conservation of biodiversity and in sustainable development. As a typical type of traditional agroecosystem, traditional homegardens have been receiving increasing attention from scientists, especially ethnobotanists. They are considered as germplasm banks for many crops and other economic plants. They are also a key site for domestication of wild plants. Current ethnobotanical studies on homegardens focus on their structures, floristic composition, and contributions to their owners. Traditional homegardens often show complicated structures, diverse floristic compositions, multiple functions, low input (including labor and money), and ecological and socioeconomic sustainability. The characteristics and functions of traditional homegardens are closely related to many factors, such as their geographic location and the cultural backgrounds and socioeconomic conditions of their owners. Many researches on homegardens are conducted in the tropics. There are few studies on the dynamics of traditional homegardens, especially those located in temperate, arid and semi-arid zones. The dynamics of homegardens and the factors affecting these processes will be a fruitful field for future research.
Forest fires frequently occur in boreal forests, and their effects on forest ecosystems are often significant in terms of carbon flux related to climate changes. Soil respiration is the second largest carbon flux in boreal forests and the change in soil respiration is not negligible. Environmental factors controlling the soil respiration, for example, soil temperature, are altered by such fires. The abnormal increase in soil temperature has an important negative effect on soil microbes by reducing their activities or even by killing them directly with strong heat. On the other hand, although vegetation is directly disturbed by fires, the indirect changes in soil respiration are followed by changes in root activities and soil microbes. However, there is very limited information on soil respiration in the forests of Northeast China. This review, by combining what is known about fire influence on soil respiration in boreal forests from previous studies of post-fire effects on soil conditions, soil microbes, and forest regeneration, presents possible scenarios of the impact of anticipated post-fire changes in forest soil respiration in Northeast China.
Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) technique was employed to examine the seasonal dynamic changes in bacterial community composition in the Inner Mongolia desert steppe using specific primers F954 and R1369. Bright and reproducible bands were sequenced, and the phylogenic tree was constructed. The results show that the bacterial community composition changed between different seasons. The specific bands were different between the sampling sites with light and heavy levels of degraded grassland. Three main types of bacteria constituting the microbial community in the Inner Mongolia desert steppe belonged to the α, γ and δ-sub phyla of Proteobacteria, Bacteroidetes and Acidobacteria. The unculturable bacteria accounted for 69% of the whole bacterial community of the Inner Mongolia desert steppe.
A field experiment was conducted to investigate the effect of growth regulators on growth characteristics such as root length, shoot length, total leaf area, number of inflorescence per plant, number of flower per inflorescence, whole plant fresh weight and whole plant dry weight. Photosynthetic characteristics were also analyzed based on the same experiment. For this, various photosynthetic pigment contents such as chlorophyll, carotenoid, anthocyanin and xanthophyll content were calculated. The conventional growth regulator abscisic acid (ABA) and non-conventional growth regulator triazole compound paclobutrazol (PBZ) were used. Root length increased due to growth regulator treatment, but shoot length decreased. Leaf area was decreased due to growth regulator treatment. The number of inflorescence increased in ABA treated plants, but it was decreased in PBZ treated plants. In ABA treated plants, the number of flowers per inflorescence was increased. In PBZ treated plants the number of inflorescence was reduced. The whole plant fresh weight (FW) and dry weight (DW) were increased in ABA and PBZ treated plants. There was an increase in chlorophyll content in growth regulator treated plants compared to control, and it was more in PBZ treated plants. The carotenoid content was also increased in ABA and PBZ treated plants.
The phenology of
We developed an efficient plant regeneration protocol for rapidly propagating
In this paper, the water quality of the Xixi Wetland was evaluated and the characteristics of water pollution were described according to the survey data. Based on the status of water quality and its functional requirements as an urban wetland, biological-ecological countermeasures were suggested. The experimental use of ecological technologies, such as artificial wetlands, ecological aquiculture and artificial floating island, were done in several fish ponds in the Xixi Wetland. Water monitoring results show that the quality of the treated water has improved significantly and the measures to purify the eutrophic water in the wetland have been effective.
The objective of this study was to evaluate the effect of some plant ecophysiological adaptations on soil microbial functional diversity in a Negev Desert ecosystem. Soil samples from the upper 0-10 cm layer were collected at the study site under three species of halophyte shrubs,