The history and future of the biological resources of the Caspian and the Aral Seas

The term ‘biological resources' here means a set of organisms that can be used by man directly or indirectly for consumption. They are involved in economic activities and represent an important part of a country's raw material potential. Many other organisms are also subject to rational use and protection. They can be associated with true resource species through interspecific relationships. The Caspian and Aral Seas are continental water bodies, giant saline lakes. Both categories of species are represented in the benthic and pelagic communities of the Caspian and Aral Seas and are involved in human economic activities. The most important biological resource of the Caspian Sea and the Aral Sea is their ichthyofauna, represented by both aboriginal species and species introduced by man in the 20 th century. Among invertebrates, the main biological resource of these saline lakes is the brine shrimp A rtemia. The physical state of the Caspian as a water body is relatively stable but its biological resources are very seriously af fected by irrational use. The Aral Sea since the second half of the 20 t h century has experienced catastrophic anthropogenic regression, which has led to the almost complete loss of its biological resources due to salinization. However, thanks to efficacious engineering measures, it has now become possible to preserve its northern part(Small Aral) and rehabilitate it, lowering the salinity to its former state. The result has been the restoration of its fish biological resources. In the southern part of Aral(Large Aral), which turned into a group of separated hypersaline reservoirs, the only resource species currently available is the brine shrimp A rtemia. The main environmental threats for biological resources of the future Caspian and Aral as well as potential solutions are considered.

Proposal of Japanese Vocabulary Difficulty Level Dictionaries for Automated Essay Scoring Support System Using Rubric

We are developing a Moodle plug-in,which is an AES(automated essay scoring)support system for the basic education of university students.Our system evaluates essays based on rubric,which has five evaluation viewpoints“Contents,Structure,Evidence,Style,and Skill”.Vocabulary level is one of the scoring items of Skill.It is calculated using Japanese Language Learners’Dictionaries constructed by Sunakawa et al.Since this does not fully cover the words used in the student-level essays,we found that there is a problem with the accuracy of the vocabulary level scoring.In this paper,we propose to construct comprehensive Japanese vocabulary difficulty level dictionaries using Japanese Wikipedia as the corpus.We apply Latent Dirichlet Allocation(LDA)to the Wikipedia corpus and find the word appearance probability as one of the indexes of word difficulty.We use the TF-IDF value instead of the LDA value of the words,which rarely appears.As a result,we constructed highly comprehensive Japanese vocabulary difficulty level dictionaries.We confirmed that the vocabulary level can be scored for all words in the test dataset by using the constructed dictionaries.