环境变迁在中国文明形成中的作用

The formation of civilization, one of great marks in the history of human's society development, has been remained one of the hottest topics in the world. Many theories have been put ford to explain its causes and mechanisms. Although more attentions have been paid to its development, the role of environmental change should not be ignored. In this paper, the level of ancient farming productivity was analyzed, the mechanisms and the process of Chinese ancient civilization formation was explored, and some causes why Chinese ancient civilization shows many different features from other 5 ancient civilizations of the world was analyzed. The main results and conclusions are presented as followed. 1. Compared with the productivity level of other five ancient civilizations, the productivity of ancient China characterized by a feature of extensive not intensive cultivation was lower than that of other five ancient civilizations whose agriculture were based on irrigation. 2. The 5 5000 a B.P. cold event may have facilitated the formation of Egypt and Mesopotamian ancient civilizations and also have had an influence on the development of Neolithic culture in China. 3. The 4 000 a B.P. cold event, which may be the coldest period since the Younger Dryas cold event and signifies the changes from the early Holocene Climate Optimum to late Holocene in many regions of the world, resulted in the great migration of the Indo-European peoples from north Europe to other part of the World and the collapses of ancient civilizations in Egypt, Indus and the Mesopotamian and the collapse of five Neolithic cultures around central China. More important than that is the emergence of Chinese civilization during the same period. Many theories have been put ford to explain why it was in Zhongyuan area not other places whose Neolithic cultures seem more advanced that gave rise to civilization. For now no theory could explain it satisfiedly. Archaeological evidence clearly demonstrate that war was prevailed the whole China especially during the late Longshan culture period, so it seemed war has played a very important role in the emergence of China ancient civilization. Carneiro sees two conditions as essential to the formation of complex societies in concert with warfare, i.e. population growth and environmental circumscription. It was generally through that China couldn't evolved into the environmental circumscription and population pressure because China has extensive areas to live, but that depends on situations. The environmental circumscription area was formed due to the 4000a B.P. cold event and companied flooding disasters, while the population pressure is formed due to three factors; 1) population grow rapidly because of the suitable environment provided by the Holocene Optimum and thus laid its foundations for the ancient human population; 2) population pressure is also related to the primitive agricultural level characterized by extensive not intensive cultivation; 3) population pressure was mainly related to the great migrations of people to the same areas; 4) population pressure was also related to productivity decrease due to the 4 000a B.P. cold event. 4. When population pressure is formed, war is the most possible way to solve the intensions between population and the limited cultivated land and then resulted in the formation of civilization. In this way the climate change during the 4 000a B.P. cold event may have facilitated the emergence of Chinese ancient civilization. Their detailed relations could also be further understood in this way: The first birth places of China ancient civilization could be in Changjiang areas or (and) Daihai area, Shandong province rather than in central China and the emergence time of ancient civilization formed in central China should be delayed if the 4 000a B.P. cold event and companied flooding disasters didn't occurred.

Molecular cloning and characterization analysis of immunoglobulin M heavy chain gene in European eel (Anguilla anguilla)

In this study, the immunoglobulin M heavy chain gene of European eel (Anguilla anguilla) was cloned and analyzed. The full-length cDNA of the IgM heavy chain gene (GenBank accession no. EF062515) has 2089 nucleotides encoding a putative protein of 581 amino acids. The IgM heavy chain was composed of leader peptide (L), variable domain (VH), CH1, CH2. Hinge, CH3, CH4, and C-terminus and two novel continuous putative N-glycosylation sites were found close to the second cysteine of CH3 in A. anguilla-H1 and A. anguilla-H2. The deduced amino acid sequence of the European eel IgM heavy chain constant region shared similarities to that of the Ladyfish (Elops saurus). Atlantic salmon (Salmo salar), rainbow trout (Oncorhynchus mykiss), Grass carp (Ctenopharingodon idella), Common carp (Cyprinus carpio), Channel catfish (Ictalurus punctatus), and the orange-spotted grouper (Epinephelus coioides) with the identity of 46.1%, 39.7%, 38.9%, 32.4%, 32.3%, 31.7%, and 30.7%, respectively. The highest level of IgM gene expression was observed in the kidney, followed by the spleen, gills, liver, muscle and heart in the apparently healthy European eels. (C) 2008 Elsevier B.V. All rights reserved.

Deceptive female oviposition behaviour elicits male ejaculation in the European bitterling

In European bitterling Rhodeus amarus, fish that lay their eggs in the gill chambers of living freshwater mussels, females perform conspicuous behaviours associated with spawning that increases the probability of males performing ejaculatory behaviour and participating in a spawning. A significant positive association was detected between behaviour in which a female performs a spawning action but without releasing eggs, here termed 'deceptive female oviposition', and ejaculatory behaviour by courting males.

A possible evolutionary lag in the relationship between freshwater mussels and European bitterling

The coevolutionary dynamics between European bitterling Rhodeus amarus and freshwater unionid mussels, which the former parasitize by laying eggs on their gills, were tested. In a series of experiments fish preferences and mussel responses were compared in parasites and hosts of recent (Europe) and ancient (Asia) sympatry. Rhodeus amarus readily oviposited on the gills of all mussel species tested. Fish that laid their eggs on the gills of Asian Anodonta woodiana, however, suffered a dramatic reduction in reproductive success compared to fish that oviposited on the gills of European mussels: Unio pictorum, Unio tumidus, Anodonta anatina and Anodonta cygnea. This difference was the result of egg ejection behaviour by mussels rather than the unsuitability of the internal gill environment for European bitterling embryo development. The ejection response of mussels with a long sympatry with European bitterling was considerably more pronounced than that of mussels with a substantially shorter sympatry. The data support a coevolutionary arms race between bitterling and mussels and point to an evolutionary lag in the relationship between R. amarus and its European mussel hosts. (c) 2007 The Authors. Journal compilation (c) 2007 The Fisheries Society of the British Isles.

Effect of cycles of feed deprivation on growth and food consumption of immature three-spined sticklebacks and European minnows

Individual juvenile three-spined sticklebacks Gasterosteus aculeatus and European minnow Phoxinus phoxinus, from sympatric populations, were subjected to four cycles of I week of food deprivation and 2 weeks of ad libitum feeding. Mean specific growth rate during the weeks of deprivation was negative and did not differ between species. The three-spined stickleback showed sufficient growth compensation to recover to the growth trajectory shown by control fish daily fed ad libitum. The compensation was generated by hyperphagia during the re-feeding periods, and in the last two periods of re-feeding, the gross growth efficiencies of deprived three-spined sticklebacks were greater than in control fish. The expression of the compensatory changes in growth and food consumption became clearer over the successive periods of re-feeding. The European minnow developed only a weak compensatory growth response and the mass trajectory of the deprived fish deviated more and more from the control trajectory During re-feeding periods, there were no significant differences in food consumption or gross growth efficiency between control and deprived European minnows. The differences between the two species are discussed in terms of the possible costs of compensatory growth, the control of growth and differences in feeding biology (C) 2003 The Fisheries Society of the British Isles.

Genetic divergence between Cyprinus carpio carpio and Cyprinus carpio haematopterus as assessed by mitochondrial DNA analysis, with emphasis on origin of European domestic carp

Although common carp is the major fish species in Asian and European aquaculture and many domestic varieties have occurred, there is a controversy about the origination of European domestic common carp. Some scientists affirmed that the ancestor of European domestic common carp was Danube River wild common carp, but others considered it might be Asian common carp. For elucidating origination of European domestic common carp, we chose two representative European domestic common carp strains (German mirror carp and Russian scattered scaled mirror carp) and one wild common carp strain of Cyprinus carpio carpio subspecies (Volga River wild common carp) and two Asian common carp strains, the Yangtze River wild common carp (Cyprinus carpio haematopterus) and traditionally domestic Xingguo red common carp, as experimental materials. ND5-ND6 and D-loop segments of mitochondrial DNA were amplified by polymerase chain reaction and analyzed through restriction fragment length polymorphism (RFLP) and sequencing respectively. The results revealed that HaeIII and DdeI digestion patterns of ND5-ND6 segment and sequences of control region were different between European subspecies C. carpio carpio and Asian subspecies C. carpio haematopterus. Phylogenetic analysis showed that German mirror carp and Russian scattered scaled mirror carp belonged to two subspecies, C. carpio carpio and C. carpio haematopterus, respectively. Therefore, there were different ancestors for domestic carp in Europe: German mirror carp was domesticated from European subspecies C. carpio carpio and Russian scattered scaled mirror carp originated from Asian subspecies C. carpio haematopterus.

A preliminary phylogenetic analysis of Metapenaeopsis (Decapoda : Penaeidae) based on mitochondrial dna sequences of selected species from the Indo-West Pacific

Phylogenetic relationships within Metapenaeopsis remain largely unknown. The modern revision of the genus suggests that the shape of the petasma, followed by the presence of a stidulating organ, are the most important distinguishing taxonomic features. In the present study, phylogenetic relationships were studied among seven Metapenaeopsis species from the Indo-West Pacific based on partial sequences of mitochondrial 16S rRNA and cytochrome c oxidase I (COI) genes. Mean sequence divergence was 6.4% for 16S and 15.8% for COI. A strikingly large nucleotide distance (10.0% for 16S and 16.9% for COI) was recorded between M. commensalis, the only Indo-West Pacific species with a one-valved petasma, and the other species with a two-valved petasma. Phylogenetic analyses using neighbor-joining, maximum parsimony, and maximum likelihood generated mostly identical tree topologies in which M. commensalis is distantly related to the other species. Two clades were resolved for the remaining species, one with and the other without a stridulating organ, supporting the main groupings of the recent taxonomic revision. Results of the present study also indicate that the deep-water forms represent a relatively recent radiation in Metapenaeopsis.

On equations for regular languages, finite automata, and sequential networks

We consider systems of equations of the form where A is the underlying alphabet, the Xi are variables, the Pi,a are boolean functions in the variables Xi, and each δi is either the empty word or the empty set. The symbols υ and denote concatenation and union of languages over A. We show that any such system has a unique solution which, moreover, is regular. These equations correspond to a type of automation, called boolean automation, which is a generalization of a nondeterministic automation. The equations are then used to determine the language accepted by a sequential network; they are obtainable directly from the network.

practical type checking of functions defined on context-free languages

A type checking method for the functional language LFC is presented. A distinct feature of LFC is that it uses Context-Free (CF) languages as data types to represent compound data structures. This makes LFC a dynamically typed language. To improve efficiency, a practical type checking method is presented, which consists of both static and dynamic type checking. Although the inclusion relation of CF.languages is not decidable,a special subset of the relation is decidable, i.e., the sentential form relation, which can be statically checked.Moreover, most of the expressions in actual LFC programs appear to satisfy this relation according to the statistic data of experiments. So, despite that the static type checking is not complete, it undertakes most of the type checking task. Consequently the run-time efficiency is effectively improved. Another feature of the type checking is that it converts the expressions with implicit structures to structured representation. Structure reconstruction technique is presented.

pattern matching compilation of functions defined in context-free languages

LFC is a functional language based on recursive functions defined in context-free languages. In this paper, a new pattern matching algorithm for LFC is presented, which can represent a sequence of patterns as an integer by an encoding method. It is a rather simple method and produces efficient case-expressions for pattern matching definitions of LFC. The algorithm can also be used for other functional languages, but for nested patterns it may become complicated and further studies are needed.

facilitating formal specification acquisition by using recursive functions on context-free languages

Although formal specification techniques are very useful in software development, the acquisition of formal specifications is a difficult task. This paper presents the formal specification language LFC, which is designed to facilitate the acquisition and validation of formal specifications. LFC uses context-free languages for syntactic aspect and relies on a new kind of recursive functions, i.e. recursive functions on context-free languages, for semantic aspect of specifications. Construction and validation of LFC specifications are machine-aided. The basic ideas behind LFC, the main aspects of LFC, and the use of LFC and illustrative examples are described.