从阿根廷金融危机分析"钉住汇率制"的利弊

1 32 0亿美元的巨额外债是阿根廷金融危机的导火索 ,而阿根廷在汇率制度上的僵化是产生金融危机的重要原因。本文以阿根廷金融危机为背景 ,分析钉住汇率制的优点主要是有利于国际贸易与资本流动 ;缺点主要是丧失独立的货币政策且不能利用汇率调整应对复杂多变的世界经济形势。对我国的启迪是人民币汇率的稳定不等于没有波动 ,汇率形成机制要市场化。     

Population biology of Sphaeroma serratum Fabricius (Isopoda,Flabellifera) at the Port of Mar del Plata,Argentina

Variations in size distribution, sex ratio, fecundity and morph frequencies in a population of Sphaeroma serratum were studied year-round. Changes in size distribution are most marked during the breeding season. Growth is arrested during the winter months. Young are produced throughout the summer; these overwinter, reproduce and then die. Differences in size of mature males suggest an effect of the timing of birth on life-span. Females are able to produce two broods. Offspring number is positively correlated with female size. Brood pouch mortality is estimated at 39%. Marked changes in sex ratio within the breeding season are thought to be artifacts due to sexual differences in behaviour. Comparison of reproductive traits of this, and other, populations shows a latitudinal pattern related to the duration of the warm season. Analysis of morph frequencies revealed similarities with European populations so far studied.     

Diet composition of an invasive population of Lithobates catesbeianus (American Bullfrog) from Argentina

The American bullfrog Lithobates catesbeianus has been introduced around the world, with invasive populations reported from almost all South American countries. A population of this species was introduced in the Calingasta department of San Juan province, which is an arid environment in western Argentina. This work provides information on the dietary composition of an invasive population of L. catesbeianus, and compares the degree of dietary overlap between adults and juveniles. Stomach contents of 169 bullfrogs (82 adults and 87 juveniles) were analysed. Adults consumed 40 prey taxa and Hymenoptera (Insecta) was the most numerous prey item (41.8%), followed by Araneae (13.6%) and Aeglidae (13.4%). Juveniles consumed 29 prey taxa and Hymenoptera constituted the highest percentage in prey number (77.2%). The trophic overlap niche index at the same level shows a value of 0.64 overlap in dietary community between adults and juveniles of this bullfrog. Aeglidae was volumetrically the most important trophic item (25.4%), followed by Anura (25.02%). Our results showed that cannibalism in bullfrogs is more common than the consumption of native anurans, coinciding with that reported in other populations of introduced bullfrogs. The high similarity in the diets of both size classes and the association between the size of the predator and prey suggest that the impact caused by bullfrogs throughout their ontogeny is high and probably has an impact on their prey. Freshwater crabs are the main items in the diet of Lithobates catesbeianus in other introduced populations and are usually the most conspicuous at our study site. The crabs in freshwater ecosystems are part of the lowest trophic level in the food chain. The major threats to the southern region’s freshwater crabs include deforestation, farming and exotic species. Lithobates catesbeianus has a generalist diet and high overlap between adults and juveniles.     

阿根廷的金融危机与资本外逃

阿根廷是美国赞扬的金融自由化典范,银行证券业向外资开放的力度大,但其爆发金融危机造成的破坏也格外严重。阿根廷金融危机与经济全球化进程,特别是与金融开放和资本市场自由化密切相关。阿根廷吸引跨国银行投资,对本国金融体系的稳定造成了极其恶劣的影响,资本外逃给民众存款造成了重大损失。中国应积极吸取阿根廷的教训,慎重对待外资收购、兼并和MBO,特别是"入世"后银行证券业的开放,更好地维护本国经济金融安全,防范风险。     

Two new phoxocephalids (Crustacea: Amphipoda: Phoxocephalidae) from the south-west Atlantic

A new genus and species, Parafoxiphalus longicarpus, and a new species, Metharpinia protuberantis belonging to the family Phoxocephalidae, are described from the Argentine Sea. Both taxa were collected from sandy substrata in the intertidal and subtidal regions. Parafoxiphalus longicarpus is related to Foxiphalus Barnard, 1979 and they share many characters, most of them in plesiomorphic condition. Metharpinia protuberantis is an intermediate species between Metharpinia Schellenberg, 1931 and Microphoxus Barnard, 1960, and its assignation to the first genus is discussed.     

Identification and characterization of Biomphalaria peregrina (Orbignyi, 1835) from Agua Escondida in northern Patagonia,Argentina

During a general malacological survey for freshwater gastropods in northern Patagonia, a population of Biomphalaria was encountered at Agua Escondida. Biomphalaria spp. are freshwater pulmonates of biomedical importance, uncommon in Mendoza Province, and often act as intermediate hosts for Schistosoma mansoni. By looking at both morphological and molecular characters, we describe a detailed process of identification and characterization of Biomphalaria peregrina from a location towards the extremity of its species range. A reference DNA ‘barcode’ is presented. As B. peregrina has been shown to be a permissive experimental host of S. mansoni, snails were also screened in the field for schistosomiasis and later in the laboratory using a novel polymerase chain reaction-based assay but no infections were found. Considering the transmission potential of this species, increased vigilance for intestinal schistosomiasis is recommended, especially if local environmental conditions become favourable for disease transmission, for example, through future climate change and intensification of irrigation.     

On four new species of Cletocamptus Shmankevich, 1875 (Copepoda: Harpacticoida) from inland waters of Argentina

Argentinean specimens of Cletocamptus of the collection of the Smithsonian Institution as well as recently collected material were analyzed and four new species are described. Cletocamptus assimilis sp. nov. and C. tertius sp. nov. seem to be related to C. levis. Cletocamptus pilosus sp. nov. seems to be related to C. stimpsoni. Cletocamptus spinulosus sp. nov. shares the armature formula of the mandibular palp, the armature formula of P1–P4 and the lower insertion level of the innermost seta of the male P5BENP with C. levis, C. assimilis sp. nov. and C. tertius sp. nov. Cletocamptus spinulosus sp. nov. shares the slender seta of the maxillulary arthrite with C. pilosus sp. nov. and C. stimpsoni, and is unique in the strong spinules along the posterior margin of the P2- to P4-bearing somites. Additional comments on some other species and an identification key to the species of Cletocamptus are presented.     

阿根廷职业教育考察情况及随想

该文就无锡职业技术学院派员考察阿根廷职业教育情况作了介绍,总结了该国职业教育的体系和特点,提出针对我国职业教育的启示和借鉴。     

Relationship between environmental conditions and host-seeking activity of Ochlerotatus albifasciatus (Diptera: Culicidae) in an agroecosystem and in an urban area in Chubut,Central Patagonia,Argentina

Ochlerotatus albifasciatus is associated with aquatic environments that are frequently flooded. Awareness of blood hematophagic activity of female mosquitoes is particularly important in species which are vectors of human disease and domestic animals. The study of host-seeking activity allows us to infer the risk of transmission of these parasites. The objective of this work was to study in an agro-ecosystem and urban area of central Argentine Patagonia the relationship between the circadian rhythm of activity of host-seeking of Oc. albifasciatus, and environmental variables. During January 2003, 99 human bait catches were carried out, of which 77.8% registered at least one individual of Oc. albifasciatus. Generalised linear models were used to evaluate the relationship between Oc. albifasciatus biting activity rate and capture time, environmental humidity, air temperature, sunshine degree, wind speed, habitat type and proximity of larval habitat. The model that best explained the variation in biting activity rate included the capture time, environmental humidity, air temperature, sunshine degree and wind speed as predictor variables. Host-seeking activity was higher in the evening than in the morning or afternoon, and it was positively related to mean air temperature and environmental relative humidity (RH), but negatively to sunshine degree and wind speed. The combination of these characteristics (wind speed less than 20 km/h, environmental temperature greater than 26°C, sunshine less than 40% and (RH) greater than 50%) would provide favourable conditions to allow seeking activity and to feed on the host. The dispersion of this mosquito could be among environmental patches that present these characteristics.