Abstract Ice-and-snow tourism (IST) is central to the Chinese ice-and-snow economy and can help achieve the green transformation and expansion of the Chinese economy. However, IST has not been defined conclusively in China. In this study, the IST concept was analyzed, and the growth of both tourism types was described using an Event–Time–Space comprehensive analysis method. Two temporal phases with large increases were highlighted in both tourisms. The factors promoting their increases were analyzed from market demand, the Beijing 2022 Olympics Winter Games, and scientific and technological developments for ice and snow. The 2020–2021 decrease in IST was primarily attributed to the COVID-19 pandemic. In addition, IST has dual challenges related to natural and socioeconomic factors. Climate warming has a long-term adverse effect on IST, particularly on glacier tourism. Traditional outdoor skiing tourism in Northeast China (NEC) may also be affected by more competition owing to increased ski tourism in the pan-Beijing-Tianjin-Hebei region, the Xinjiang Uygur Autonomous Region (XJUAR) and Southern China, as well as by the development of indoor skiing and ice/snow entertainment. These natural and socioeconomic factors currently limit the ability of IST to promote socioeconomic development in alpine areas, particularly in western China. However, there are many opportunities for future IST growth, including warmed comfort climate at high altitudes in the NEC, XJUAR and the Qinghai-Tibet Plateau, major glacier resource potentials, and IST development driven by policies. The findings of this study provide important information for decision-makers and investors in IST and its related industries.
The Nile tilapia is the most productive and internationally traded food fish in the world. Many Nile tilapia families are needed to develop breeding programs for this species. The aim of this study was to develop Nile tilapia families using the Oreochromis species unique breeding characteristics (male territory establisher and female mouth brooders) and determine the mixing rate within each family. Both male and female fish were cultured in one pond in the reproductive season and the female mouths were checked every 5–8 days. When embryos were present, they were removed and cultivated independently as a family. As a result, 45 families were developed from the 60 female fish sampled. The embryo survival rate in aerated water varied from 85.5 to 100.0%. Seven polymorphic microsatellite loci were selected from a set of 31 for paternity identification. The CPE (combined paternity exclusion probability) of two microsatellite loci was higher than 0.93 and the CPE for the seven loci used in this study was as high as 0.9999. There were no unrelated individuals in five of the seven families analyzed and only one mixed individual in F29 and F30. The overall admixture rate was very low (2.2%). In this study, we developed an optimized group mating system. Furthermore, we verified that for group mating systems there were no mixed individuals in most families and the admixture rate of some families was very low according to the paternity analysis.
Understanding genomic bases of environmental adaptation is central to evolutionary biology and important for assessing adaptive potential of organisms under rapid climate change. Climate change is causing profound changes in world’s ocean, and genomic studies on keystone marine species such as the estuarine oyster ( Crassostrea ariakensis ) may inform how marine ecosystems respond to environmental shifts. We constructed a chromosome-level assembly of the estuarine oyster genome that spans 613.89 Mb and encodes 29,631 proteins. Resequencing of 264 wild individuals across wide latitude distribution revealed remarkably low genomic diversity in the estuarine oyster compared with its sister species and fine population structures shaped by historical glaciation, geological events and oceanographic forces. Genes from regions under selection were mostly involved in responding to temperature and salinity stress, demonstrating selection by these two environmental factors is a strong evolutionary force. Genes under selection included a large cluster of tandemly duplicated members of the solute carrier membrane transport protein families which are also expanded in two other low-salinity oyster species, highlighting the significance of membrane transporter expansion in estuarine adaptation. Genes exhibiting high plasticity showed strong selection in upstream regulatory regions that modulate transcription, indicating selection favoring plasticity. This study revealed genomic signatures of past glaciation and fine population structures shaped by climate history, physical forces and selection in a bivalve mollusc. Our results show gene expansion and selection in regulatory regions enhance phenotypic plasticity that is critical for organisms to survive and adapt to rapidly changing environments.
With the exploration and development of oil and gas fileds going towards into deep-water fields, high waxy reservoir has much more flow assurance issues of encourage complex solids depositions in the transportation system, especially hydrates and wax. Applying risk management such as hydrate slurry technology to control hydrate blockage, has much more economic and technical advantages, comparing to the traditional methods. It is significant to understand the viscosity of the waxy-hydrate slurry using hydrate slurry technology in high wax content reservoir. In this work, based on a simplification idea by coupling the wax content effect into the viscosity, volume and density of the water-in-waxy oil emulsion, a new viscosity model of waxy-hydrate slurry is established according to the Einstein effective medium theory, based on the experiments carried out in a high-pressure rheology system with different wax contents ranging from 0.5 wt%∼2.0 wt%. The effect of the complex aggregate coupling wax-hydrate-water is considered by function the non-Newtonian coefficient by four dimensionless parameters. Well-fitting results within an improved deviation of ±15% indicate the feasibility of this method is feasibility. This work can provide a valuable reference for the application of hydrate slurry technology in deep-water fields with high wax content reservoir.
Abstract. The role of copepod Calanus sinicus on the production of dimethylsulfide (DMS)/dimethylsulfoniopropionate (DMSP) in Jiaozhou Bay was evaluated in field and laboratory experiments. Samples at 10 sites in the bay were collected monthly from June 2010 to May 2011 (except for March 2011), and zooplankton species composition was analyzed. The relationship between copepod abundance and DMS or DMSP concentration was investigated. Effects of C. sinicus grazing on DMS/DMSP production at different conditions (i.e., algal diets, food concentrations, and salinities) were assessed in the laboratory. Data from the field experiment showed that C. sinicus was the predominant copepod in Jiaozhou Bay (up to 123 individuals m−3 in May 2011) and has no apparent effect on DMS/DMSP production. In the laboratory experiment, compared with Gymnodinium sp. or Emiliania huxleyi, C. sinicus feeding on Isochrysis galbana and Chaetoceros curvisetus exhibited increased DMS concentration, whereas high salinity inhibited DMS production. This study indicated that DMSP was transferred from phytoplankton to copepod body, fecal pellet, and seawater through copepod grazing. Our results provided important information to understand the biogeochemical cycle of DMSP in Jiaozhou Bay.
The perceptions and attitudes of community residents are a “mirror” of tourism development. Little research has been conducted on the effects of place attachment and emotional solidarity on community residents’ attitudes toward tourism in China’s glacier tourism-related areas. In this paper, we selected the southernmost marine glacier in China, Hailuogou Glacier Forest Park, as a case study, and constructed a structural equation model of residents’ tourism perceptions and attitudes based on 358 valid questionnaires obtained from fieldwork. We analyzed the logical connection and influencing relationship between place attachment, residents’ perceptions (residents’ benefits and environmental perceptions), and community residents’ attitudes (security, support, satisfaction), and explored countermeasures and suggestions for building a harmonious host–customer relationship in the Hailuogou area to improve glacier tourism. The results of the study show that the influence of place attachment and residents’ perceptions on emotional solidarity is different from the degree of influence of emotional solidarity on residents’ tourism attitudes, with the most significant positive influence of place attachment on emotional solidarity and the greatest influence of emotional solidarity on sense of security. Emotional solidarity had a certain mediating effect between place attachment, residents’ perceptions, and residents’ tourism attitudes. Significantly, emotional solidarity had the most fully mediated effect between place attachment and support, reaching 73.61%. The moderating effect of place attachment reflects that the higher the place attachment, the weaker the correlation between residents’ perceptions and residents’ tourism attitudes. Meanwhile, residents’ tourism attitudes will weaken their influence with the increase in emotional solidarity. Based on the above results, relevant suggestions are made to provide a theoretical basis and decision-making reference for the development and management of glacier tourism destinations.
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