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1.
Chicoric acid was isolated from dandelion (Taraxacum officinale Wigg.) leaves by column chromatography. Conditions for HPLC analysis of chicoric and chlorogenic acids were optimized. These acids were assayed in some plants growing in Georgia. The optimum conservation temperature for the preservation of chicoric and chlorogenic acids in leaves of dandelion and bilberry (Vaccinium arctostaphylos L.) was determined. 相似文献
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Summary Systematic observations were made on reindeer feeding behaviour during 1973–74, and seven phanerogams and three bryophytes were selected for sampling during the following year. Material of the principal plant species in the main communities at a study site was harvested and analysed for crude fibre, holocellulose, nitrogen, phosphorus, potassium, calcium, magnesium and ash. Contrary to expectation, crude fibre data show an early season peak in most species, whereas holocellulose data are more variable. Seasonal trends in mineral elements were similar to those found in nearby ungrazed vegetation, and to those in northern temperate species, although absolute values were often higher than in the latter. Data from material collected within and outside a deer-proof exclosure suggest some degree of nutrient input by the animals in the grazed situation, and nutrient enrichment was also apparent at a site colonized by white-chinned petrels. Differences in nutrient content occurred in species collected from both a freely-drained, exposed site and a wetter, more sheltered area, but these were not consistent. Data are considered in relation to the diet of South Georgia reindeer as determined by rumen content analysis, and are compared with those of forage species of northern reindeer and caribou. 相似文献
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We studied 12 small, seasonally flooded, depressional wetlands on the Atlantic Coastal Plain of Georgia, U.S.A. Each wetland was embedded in stands of managed plantation pine. The pine trees surrounding each wetland had been harvested and replanted beginning in 1997 (2 sites), 1995 (2 sites), 1993 (1 site), 1988 (2 sites), 1984 (2 sites) or 1975 (3 sites). Regressions of various environmental variables with harvest histories indicated that those wetlands surrounded by smaller trees had greater light levels, water temperatures, pH, herbaceous plant cover and biomass, terrestrial invertebrate diversities and numbers, and water flea numbers, and lower water electrical conductivities and aquatic oligochaete numbers than those wetlands surrounded by more mature trees. Detected variations in hydroperiod, water depth, dissolved oxygen levels, sediment inputs, macrophyte diversity, periphyton biomass and densities of most aquatic invertebrates were not clearly correlated with past histories of peripheral tree harvest. This study suggests that harvesting trees around small wetlands initiates physical and ecological changes within the embedded habitats and that changes can persist for up to 15 years. 相似文献
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Duane R. Diefenbach Leslie A. Baker William E. James Robert J. Warren Michael J. Conroy 《Restoration Ecology》1993,1(4):241-247
Many felids are threatened by loss of habitat, lack of genetic diversity, and over-exploitation. The reintroduction of bobcats (Felis rufus) to Cumberland Island, Georgia provided an opportunity to reintroduce a mid-sized felid without the concern for species survival that is paramount with endangered species. We captured bobcats from the coastal plain region of Georgia, briefly held them in captivity, and released them on Cumberland Island. We describe and evaluate the protocols and techniques used to accomplish the reintroduction. Future reintroductions of felids should consider the problem of post-release dispersal, although our island was relatively isolated and inhibited dispersal. Also, any reintroduction effort should invest effort and resources into post-release monitoring of the population. Empirical knowledge about the effects of spatial distribution, genetics, population dynamics, especially mechanisms of population regulation, behavior, and environmental conditions on the viability of populations is critical to the conservation of endangered species. Future research of the bobcats on Cumberland Island will be able to address aspects of the population and genetic dynamics of a small, insular felid population. 相似文献
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Kurashvili BE 《Parasitology today (Personal ed.)》1988,4(6):177-179
Intensive fish breeding in artificial freshwater reservoirs and ponds is often accompanied by epidemics of invasive parasitic diseases. In the USSR, much attention is given to the study of fish parasites and diseases, revealing a range of protozoan and helminth parasites that can cause significant economic losses to the fish industry (Table I ; Refs 1-5). 相似文献
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Tatia Kuljanishvili Giorgi Epitashvili Jörg Freyhof Bella Japoshvili Lukáš Kalous Boris Levin Namig Mustafayev Shaig Ibrahimov Samvel Pipoyan Levan Mumladze 《Zeitschrift fur angewandte Ichthyologie》2020,36(4):501-514
We present a critical checklist of freshwater fish species found so far in the countries of Armenia, Azerbaijan and Georgia. In total 119 freshwater fishes are recorded. There are 40, 86 and 96 species currently known for Armenia, Azerbaijan and Georgia respectively. From these 119 species, seven are endemic and seven species are alien. From the alien species, only three (Carassius gibelio, Gambusia holbrooki and Pseudorasbora parva) can be considered as widespread and invasive. There are four species (Gasterosteus aculeatus, Gobio artvinicus, Perca fluviatilis and Salmo gegarkuni) that are translocated within the region. Seven species are confirmed or recorded for the first time including G. artvinicus and Oxynoemacheilus veyselorum for Armenia, Azerbaijan and Georgia, Capoeta kaput and Rhinogobius lindbergi for Azerbaijan and Georgia, Capoeta razii for Azebaijan, Oxynoemacheilus cemali and Squalius agdamicus for Georgia. In this checklist, Acipenser colchicus is treated as a synonym of Acipenser persicus. Sand smelts of the Black and Caspian Sea basin are identified as Atherina caspia and Clupeonella caspia is treated as a synonym of Clupeonella cultriventris. Coregonus sevanicus is listed as Coregonus sp. until the situation of Sevan whitefish is better understood. Capoeta sevangi and Capoeta ekmekciae are synonyms of Capoeta capoeta. The fish often identified as Capoeta capoeta gracilis from rivers south of the Kura most likely belong to C. razii. The Black and Caspian Sea Rutilus populations are treated as conspecific, therefore R. kutum is a junior synonym of R. frisii. Oxynoemacheilus veyseli is valid as O. veyselorum. We list the alien Rhinogobius species as R. lindbergi, however the name is provisional and needs further confirmation. All Squalius species from the Kura River drainage are identified as S. agdamicus, however in the Aras, it is replaced by S. turcicus. Squalius orientalis is treated as a valid species restricted to the eastern Black Sea basin. The four forms of Lake Sevan trout (Salmo ischchan, S. gegarkuni, S. danilewskii and S. aestivalis) are treated as valid species, two of them (S. ischchan and S. danilewskii) are extinct. Rutilus sojuchbulagi from Azerbaijan is also extinct. 相似文献
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《Cell cycle (Georgetown, Tex.)》2013,12(19):3848-3850
Georgia is situated in the Caucasus region where Eastern Europe and Western Asia meet. The country covers a territory of 69,700 km² and its population is 4.385 million people. Formerly a part of the Soviet Union, Georgia restored its independence in 1991. Since then the country has struggled to renovate its economical and political structure, while saving the best from the past and exploring new opportunities. Bioscience is an essential part of this process. We have interviewed several leading Georgian scientists and asked them to describe the problems and accomplishments in their areas of bioscience. 相似文献
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Large numbers of 2 species of Entamoeba, Entamoeba coli and Entamoeba bovis, were recovered from captive white-tailed deer from Georgia. The trophozoite of the first ameba was a large form with a well-defined vesicular nucleus bearing a prominent eccentric endosome, abundant peripheral chromatin, and numerous periendosomal granules. Cytoplasmic vacuoles containing bacteria and other substances were common. Mature cysts were octonucleate. Glycogen vacuoles and irregularly shaped chromatoids were frequently present. This ameba was identified as Entamoeba coli. The trophozoite of the second ameba was small, with a typical Entamoeba nucleus. Cysts were uninucleate, containing numerous chromatoids resembling bars, splinters of wood, and irregular masses. There was occasionally a glycogen vacuole. This ameba was identified as Entamoeba bovis. 相似文献
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Tidal wetlands are threatened by global changes related not only to sea level rise but also to altered weather patterns. To predict consequences of these changes on coastal communities, it is necessary to understand how temporally varying abiotic conditions drive wetland production. In 2000–2011, we conducted annual surveys of Spartina alterniflora biomass in tidal marshes at nine sites in and around the Altamaha river estuary on the coast of Georgia, USA. End of the year live biomass was assessed in the creekbank and midmarsh zones to estimate annual net primary production (ANPP). River discharge was the most important driver of S. alterniflora ANPP, especially in creekbank vegetation. Increased river discharge reduces water column salinity, and this was most likely the proximate driver of increased production. In the midmarsh zone, the patterns were less distinct, although river discharge was again the best predictor, but maximum temperature had similar predictive ability. In contrast to results from terrestrial grasslands, we found no consistent evidence for a sharply delimited critical period for any climate driver in the tidal marsh, which indicates that plant growth was responsive to abiotic drivers at any time during the growing season. Results were broadly consistent across multiple sites within a geographic region. Our results differ from previous analyses of production in S. alterniflora marshes, which either identified oceanic drivers of S. alterniflora production or were unable to identify any drivers, likely because the low-latitude sites we studied were hotter and more affected by river discharge than those in previous studies. 相似文献
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Power A McCrickard B Mitchell M Covington E Sweeney-Reeves M Payne K Walker R 《Diseases of aquatic organisms》2006,73(2):151-158
Oysters Crassostrea virginica are 'keystone' estuarine species in the southeastern USA, providing essential fish habitat, food for human consumption, filtration of water bodies, and protection against shoreline erosion. Relatively few oyster pathology studies have been conducted in Georgia. The parasitic protozoan Perkinsus marinus was first observed here in the 1960s, but has not been investigated since the late 1990s, when increasing oyster infection levels were apparent. In the late 1990s and early 2000s, the region suffered a prolonged drought, resulting in elevated salinities and the proliferation of various diseases in the marine environment. By 2003, salinities had returned to normal levels, but the effect of the drought on oysters was unknown. In June 2003, oyster reefs throughout Chatham County were sampled to evaluate the prevalence and intensity of P. marinus. The disease appears to have remained prevalent in the coastal waters of Georgia (100% prevalence at some sites), but the intensity was low, ranging from 0 to 1.83 on a scale where heavy infections rated a score of 5. While the disease did not occur at levels high enough to cause oyster mortalities, further monitoring, particularly on a temporal scale, is warranted. 相似文献
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Qualitative samples of Collembola were obtained from a range of substrates near Husvik, Stromness Bay, South Georgia, between
January and March 1996. Collections made at Hope Point near Grytviken (Cumberland East Bay) in 1980/1982 and 1997 were also
examined. Fifteen species of Collembola were recorded around Husvik; most were widely distributed. Two of these, Friesia sp. nov. and Cryptopygus badasa, represent additions to the previously recognised fauna of 17 species. A new record of an introduced species, Hypogastrura purpurescens, was identified in collections from Hope Point in 1980/1982, bringing the total South Georgian fauna to 20 species. A key
to South Georgian Collembola is included. H. purpurescens and the congeneric Hypogastrura viatica, both cosmopolitan invasive species, have also been recognised on other sub-Antarctic islands and have displaced resident
species from some habitats. Their presence on South Georgia, and the dominance of H. viatica in some habitats, highlight the importance of strict quarantine measures to avoid the introduction of further alien invertebrates.
Accepted: 30 November 1998 相似文献
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Wilfrida Decraemer 《Hydrobiologia》1984,119(3):181-191
Two new desmoscolecid species are described: Desmoscolex koloensis sp. nov. and D. parakoloensis sp. nov. Additional information is given on Desmoscolex (Desmolorenzenia) montana, D. sieverti and D. fennicus. The genus Desmolorenzenia is considered a subgenus of Desmoscolex. Pareudesmoscolex lacustris represents a juvenile state of Desmocolex dussarti. Some reflections are made on terrestrial and freshwater desmoscolecids. 相似文献
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Serologic testing, radio-telemetry and post-mortem diagnostic evaluations were used to investigate survival and causes of mortality among 17 coyotes (Canis latrans) in south-central Georgia (USA). Prevalence of canine heartworm (Dirofilaria immitis) microfilariae was lower (P = 0.057) among fall-captured (22%) than among winter-captured (75%) coyotes. Prevalence of heartworm was higher among adults than juveniles in the fall, but no significant difference was detected between animals captured in winter. Antibodies were found against canine parvovirus (65%), canine parainfluenza virus (59%), infectious canine hepatitis virus (41%), and Toxoplasma gondii (18%). Antibodies were not found to Brucella canis, canine coronavirus, five serovars of Leptospira interrogans, or canine distemper virus. Seroprevalence of canine parvovirus was lower (P = 0.009) among fall-captured animals (33%) than winter-captured animals (100%). The Kaplan-Meier estimate of annual survival was 0.500 for all animals. Juvenile survival did not differ (P = 0.79) from adult survival, but male survival (S = 0.217) was lower (P = 0.11) than female survival (S = 0.804). Two of nine (22%) mortalities were human-caused, one was due to concurrent canine parvovirus and canine distemper virus infections, one animal died of trauma, two were considered natural mortalities of unknown cause, and no cause of death could be determined for the remaining three animals. Natural mortality may be significant for coyotes in south-central Georgia, although there was no apparent link between exposure to pathogens and the animals' subsequent fate in our small sample. 相似文献
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Yuanyuan Shao Hans-Otto Baral Xiaoyun Ou Hao Wu Fuchang Huang Haifu Zheng Bin Liu 《Mycological Progress》2018,17(11):1225-1235
Orbilia georgiana and O. renispora are described as new species to science, in addition, O. eucalypti, O. occulta, and O. xanthoguttulata are reported based on collections taken from the state of Georgia, USA. Orbilia xanthoguttulata is a new record for North America. The morphology of all species is described based on both sexual and asexual morphs. Asexual morphs were obtained from ascospore isolates, from which also DNA was extracted and used to amplify rDNA genes (ITS and LSU) for phylogenetic comparison. 相似文献