首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 21 毫秒
1.
In 1843 S. B. Buckley (1809–1884) traveled up the St. Johns River, Florida in search of plants, shells, and possibly other natural history objects. Buckley encountered many difficulties in interior Florida and his trip did not live up to his original expectations. It was unfortunate that the took years to distribute his plant specimens, since few botanists or naturalists had preceded him into that poorly explored region.  相似文献   

2.
The first recorded bloom of Karenia spp., resulting in brevetoxin in oysters, in the low salinity waters of the Northern Gulf of Mexico (NGOMEX) occurred in November 1996. It raised questions about the salinity tolerance of Karenia spp., previously considered unlikely to occur at salinities <24 psu, and the likelihood that the bloom would reoccur in the NGOMEX. Salinity was investigated as a factor controlling Karenia spp. abundance in the field, using data from the NGOMEX 1996 bloom and Florida coastal waters from 1954 to 2004, and growth and toxin production in cultures of Karenia brevis (Davis) G. Hansen and Moestrup. During the NGOMEX bloom, Karenia spp. occurred much more frequently at low salinities than in Florida coastal waters over the last 50 years. The data suggest that the NGOMEX bloom started on the NW Florida Shelf, an area with a higher frequency of Karenia spp. at low salinities than the rest of Florida, and was transported by an unusual westward surface current caused by Tropical Storm Josephine. The minimum salinity at which growth occurred in culture ranged between 17.5 and 20 psu, but the optimal salinity ranged between low values of 20 or 25 and high values of 37.5–45 psu, depending on the clone. The effect of salinity on toxin production in one clone of K. brevis was complex, but at all salinities brevetoxin levels were highest during the stationary growth phase, suggesting that aging, high density blooms may pose the greatest public health threat. The results demonstrate that Karenia spp. can be a public health threat in low salinity areas, but the risk in the NGOMEX is relatively low. No bloom has occurred since the 1996 event, which was probably associated with a special set of conditions: a bloom along the Florida Panhandle and a tropical storm with a track that set up a westward current.  相似文献   

3.
Larval release patterns in brachyuran crabs are often synchronized with environmental cycles. While previous studies have focused extensively on supratidal and intertidal taxa, there have been relatively few investigations of subtidal species. This study examined patterns of larval release by the Florida stone crab, Menippe mercenaria, from three different tidal regimes. Ovigerous stone crabs were collected from Sebastian Inlet on the east coast of Florida, Tampa Bay on the west coast of Florida, and the Florida Keys. Patterns of larval release were monitored in the laboratory in relation to local tidal and diel cycles. Results showed a significant diel pattern in initiation of hatching by crabs from each of three study areas. Larval release consistently occurred during the diurnal phase despite the maintenance of females in constant laboratory conditions for up to 96 h prior to hatching. This implies that release may be controlled by a circadian clock. Patterns of release by stone crabs in relation to tidal cycle were more variable. Larval release by females from populations near Tampa Bay and Sebastian Inlet were not synchronized with the tides, whereas females collected from the Florida Keys exhibited a pattern that was strongly related to tidal cycle. These results may be explained by differences in tidal amplitude at the three sampling locations.  相似文献   

4.
The calcifying cave inhabitant atmophytic blue-green algaGeitleria calcarea is reported from new localities in Florida and in the Cook Islands.—G. floridana n. sp., is described from caves in Florida. The calcified sheath has the shape of a quadratic prism and is built of crystalline acicular subunits about 0.1 µm in diameter. The subunits mostly form a rhombic lattice pattern but in some cases, they are not distinguishable and then the surface of the sheath is smooth.This paper is dedicated with gratitude to my former teacher, Prof. Dr.Lothar Geitler, for his 80th birthday.  相似文献   

5.
Cabbage looper larvae, Trichoplusia ni, were equally susceptible to isolates of the entomogenous fungus Nomuraea rileyi from Missouri, Mississippi, and Brazil; an isolate from Florida was 7–17 times less active than the other isolates. Velvetbean caterpillars, Anticarsia gemmatalis, were either only slightly susceptible or not susceptible to the isolates of N. rileyi from Missouri, Florida, and Mississippi. In contrast, larvae of A. gemmatalis cultured from three locations (Missouri, Florida, and Brazil) all were equally susceptible to a Brazilian isolate of N. rileyi.  相似文献   

6.
Genetic data were used to compare the structure of native house fly populations collected in North Dakota, Texas, and Florida. Recombination studies with mutant markers on chromosomes 3 and 4 indicated a lack of inversion polymorphism among the three populations in those areas of the genetic map studied. Significant differences were observed among flies from the three regions with regard to the frequency of 1) females that produced only male progeny, and 2) male-determining 3rd chromosomes (IIIm chromosomes). However, the North Dakota and Texas flies were more similar to each other than to the Florida flies since populations from the two former areas possessed a low frequency of both male-producing females and IIIm chromosomes; in contrast, the Florida population was void of females that produced males only and a high percentage if not all Florida males appeared to possess the IIIm male-determining mechanism. Tests for recessive lethal 3rd chromosomes showed that there was no significant difference in the frequency of lethal factors recovered from the North Dakota and Texas flies; the presence of IIIm chromosomes in Florida males precluded the recovery of lethal factors from this population by the method employed. The data suggest that house fly strains to be employed in genetic control programs should 1) originate from target control areas to avoid possible behavioral differences existing among flies from different locales, 2) be initiated with as many flies as possible to provide a background for the maintenance of variability, and 3) be renewed periodically with field-collected material since the genotype may be capable of rapid reorganization in response to laboratory selection pressures.  相似文献   

7.
Two members of the floating fern genus Salvinia (Salviniaceae), S. minima Baker and S. molesta Mitchell, have established in the United States. Cyrtobagous salviniae Calder and Sands (Coleoptera: Curculionidae), long established on Florida S. minima, was released in Texas and Louisiana as a biocontrol agent for both species. Subsequently, sequence analysis of the 28S rRNA D2 expansion domain suggested that the Florida and Brazilian populations (used worldwide for biocontrol) of C. salviniae might constitute two cryptic species. In response, the Brazilian weevil was imported from Australia and released instead onto S. molesta. We sampled C. singularis Hustache and C. salviniae from their native ranges in Brazil, Argentina, and Paraguay and sequenced them (D2) along with Australian and Florida samples. The genetic distance between C. singularis and C. salviniae samples is much greater (almost 5×) than the distance between either the Florida and Brazilian samples or the Brazilian and Argentinean/ Paraguayan C. salviniae samples. Since C. singularis and C. salviniae are cryptic species, the Florida and Brazilian populations (or for that matter Brazilian and Argentinean/Paraguayan) could reasonably be described as demes or ecotypes. Occurrence data indicates that, in parts of their ranges, C. salviniae and C. singularis are not only sympatric but also feed on the same plant species at the same site. While host adaptation (species preferences) likely occurs within local demes, both species seem capable of adapting to the available resource (Salvinia species). Finally, a polymerase chain reaction (PCR) primer was developed to distinguish the Florida and Brazilian/Australian types.  相似文献   

8.
I G Levy  N A Iscoe  L H Klotz 《CMAJ》1998,159(5):509-513
A 70-year-old woman who experienced a long period of depression after her first husband''s death from prostate cancer at the age of 63 has become increasingly anxious about her own health and that of her close family. A few years ago she married a man her own age; he is in good physical condition. Last year the family spent much of the winter in Florida, where the woman noticed several studies in the media suggesting that an epidemic of prostate cancer is occurring in North America and that because early detection can save lives men of retirement age should be checked by their physicians as soon as possible. In addition, 2 close friends recently diagnosed with prostate cancer. On his latest fishing trip her husband learned from a friend that 1 in 8 men get prostate cancer. He has not seen his family physician for several years, but his wife has booked an appointment for them to discuss their concerns.  相似文献   

9.
Summary The present experiment compared the establishment of a position habit and three subsequent response shifts with and without discriminative stimuli. The discriminative stimuli employed were (a) 90° and 180° polarization patterns and (b) high and low intensity levels. A significant difference (0.05) was found between the running time performance of the polarization discrimination group and the uniform illumination and bright-dark discrimination groups. No similar difference was found with errors as the dependent measure, and no significant between group differences were found during the response shifts. The conclusion was drawn that the extra-ocular hypothesis could not account for the significant difference.This paper is taken from a Master's Thesis submitted to the Florida State University by the senior author, under the direction of the junior author, in partial fulfillment of the requirements for the degree of Master of Science. A portion of this paper was presented at the 1965 meeting of the American Psychological Association.This research was partially supported by a grant from the Florida State University Research Council. The statistical analyses were made possible in part by a National Science Foundation grant (# GP 671) to the Florida State University Computation Center. The authors are indebted to Dr. F. J. King, Institute of Human Learning, Florida State University, for his contribution to the data analysis.  相似文献   

10.
Field surveys indicated that individuals of Halimeda incrassata (Ellis) Lamouroux, a rhizophytic alga, were significantly more mineralized when collected from phosphate-limited carbonate sediments of the Florida Keys than those collected from siliciclastic sediments at Tarpon Springs on the west coast of Florida. Results from field experiments in Tarpon Springs, which compared growth of H. incrassata in enriched conditions to unmanipulated controls, indicated that biomineralization of new growth was significantly lower when phosphate was added to plots. After 18 days in a tank culture experiment, newly produced segments of H. incrassata grown in 20 µM phosphate showed a significant decrease in mineralization compared to the new growth in control tanks. Phosphate enrichment also led to a non-significant increase in segment mortality and a significant decrease in amount of new growth. Results from the survey and experimental studies suggest that biomineralization of H. incrassata is negatively impacted by elevated phosphate levels.  相似文献   

11.
A new method to estimate within-species gene genealogies was used to establish linkages among individuals associated with the Florida dental human immunodeficiency virus transmission case. Phylogenetic relationships were estimated from 103 nucleotide sequences from the V3 region of the env gene representing the Florida dentist, eight of his seropositive patients, and many local controls. The cladogram estimation procedure supports linkages among individuals within the previously described dental clade, whereas local controls and other patients form independent networks or are outliers in the main network, indicating more distant evolutionary relationships. A nested statistical analysis also indicates significant cohesion of the dental clade group.  相似文献   

12.
Samples representing the three nominal subspecies of Floridichthys carpio were examined electrophoretically. Although the populations in Florida could not be distinguished completely from the populations in Yucatan by morphology, 5 of the 30 electrophoretic characters demonstrated fixed differences between Florida and Yucatan populations. Based on the observed genetic differentiation between Florida and Yucatan populations and the absence of genetic differentiation within those populations, we conclude that the Yucatan population has diverged to the species level. We, therefore, propose to elevate the nominal Yucatan subspecies Floridichthys carpio polyommus to a species status.  相似文献   

13.
Aphytis holoxanthus Debach is an important biological control agent of Florida red scale, Chrysomphalus aonidum (L.). Laboratory tests quantified the mortality of this hymenopteran parasite caused by field residues of carbaryl and dicofol. Behavior and mortality of adult A. holoxanthus on carbaryl-treated “Hamlin” orange leaves were related to quantities of dislodgeable pesticide residues over time as field residues weathered. After 24 h, mortality of A. holoxanthus by dicofol was not observed through day 31 when the experiment was terminated. Our data showed that field-weathered carbaryl residues killed A. holoxanthus for a period of up to 22 days posttreatment under spring conditions in Florida.  相似文献   

14.
Institutions of higher learning and their faculty must make a significant commitment to participate in the revitalization of the science curriculum. An active science outreach program within colleges and universities can have a pronounced impact on science education at relatively little expense. This partnership requires time, energy, and the willingness to share one's dedication and enthusiasm for his/her vocation.  相似文献   

15.
Dogs were trained to detect Eastern subterranean termites, Reticulitermes flavipes (Kollar), using the United States Customs method of scent detection dog training modified with a food reward. Dogs were tested with various numbers of Eastern subterranean termites placed in vented PVC containers. Trained dogs were 95.93% accurate in finding > or = 40 Eastern subterranean termite workers (positive indications) and incorrectly indicated the presence of termites in 2.69% of the containers without termites. Multiple species of termites [dark southern subterranean, R. virginicus (Banks); Formosan subterranean, Coptotermes formosanus Shiraki; powderpost, Cryptotermes cavifrons Banks; and southeastern drywood termites, Incisitermes snyderi (Light)], were similarly evaluated. Dogs trained to locate Eastern subterranean termites were also 100% accurate in finding dark southern subterranean termites, 98.89% accurate in finding Formosan subterranean termites, 97.33% accurate in finding powderpost termites, and 88.89% accurate in finding southeastern drywood termites. Dogs were able to discriminate live termites from non-termite material. Trained dogs' false response rate was 25.33% to Eastern subterranean termite-damaged wood, 6.67% to American cockroaches, Periplaneta americana (L.), and 2.67% to Florida carpenter ants, Camponotus floridanus Buckley.  相似文献   

16.
Invasive weeds are potent agents of environmental change. Wetlands are valuable environments that frequently are impinged by a variety of threats including invasive weeds. Melaleuca quinquenervia (Cav.) S.T. Blake (broad-leaved paperbark), though experiencing major diminishment of native populations in Australia, is naturalized and highly invasive in most wetland habitats of south Florida, U.S.A., where it infests more than 202,000 ha. Wetlands in south Florida, including such renowned areas as the Everglades, are being transformed into M. quinquenervia swamps, with major environmental and economic impacts. Current management methods include herbicides, mechanical or hand removal of plants, flooding, and prescribed burning. Insufficient information, high costs, non-target impacts, and the resilience of M. quinquenervia (trunk and root sprouts and massive canopy seed banks) greatly constrain the effectiveness of these control methods. Biological control offers long-term management potential, most likely by reducing the rate of spread and the vitality and growth rate of plants, thus rendering them more vulnerable to other environmental stresses and control methods. The leaf weevil Oxyops vitiosa Pascoe, a natural enemy of M. quinquenervia in Australia, will likely be the first biocontrol agent released against the weed in Florida. More information is needed, especially ecological data, to better understand the invasiveness of M. quinquenervia in Florida and to facilitate its management there.  相似文献   

17.
Thiothrix spp., sulfide-oxidizing filamentous bacteria, were found to be a principal bacterial component of aquatic biofilms causing biofouling in selected municipal water storage tanks, private wells, and drip irrigation systems in Florida. Treatments of up to 200 ppm chlorine in the affected systems could not prevent return of the biofouling problem. The water originated from the upper Floridan aquifer and associated surficial aquifers in central and north Florida. Samples were examined where visible biofilms had a white, filamentous appearance, indicative of Thiothrix spp. The detection of Thiothrix spp. was confirmed by enzyme-liked immunosorbent assay (ELISA), indirect immunofluorescence (IIF), and microbiological procedures. It was estimated through immunocytochemical procedures that Thiothrix spp. comprised 18% of the biofilm in the municipal water storage tanks. These observations confirm that specific biological and chemical interactions may induce physical changes leading to significant biofouling. Received: 6 November 1996 / Accepted: 14 March 1997  相似文献   

18.
During the century following its initial introduction in 1886, the Australian tree Melaleuca quinquenervia (Myrtaceae) dispersed from a few introduction points to occupy over 200,000 ha, primarily in historic Everglades wetlands of southern Florida. Cellulose acetate gel electrophoresis (CAGE) was used to investigate the allozyme diversity and population genetic structure of 208 individuals in a dozen populations resulting from this invasion. The analyses showed that these populations have a high (82%) rate of polymorphic loci and an average of 2 alleles/locus. There was substantial heterozygosity (mean He = 0.356), which concords well with recent studies reporting a greater number of introduction events and sources than generally recognized. The introduction history and distributional patterns within Florida have led to geographic structuring (GST = 0.419) in which the Gulf Coast metapopulation has a greater effective number of alleles and greater heterozygosity than the Atlantic Coast metapopulation. The gene diversity in M. quinquenervia was comparable to other tropical woody species. Its strong population divergence was reminiscent of pioneer species and consistent with its status as a plant invader in Florida.  相似文献   

19.
B G Leask  D Yarrow 《Sabouraudia》1976,14(1):61-63
A new yeast species Pichia norvegensis Leask et Yarrow is described as the perfect state of Candida norvegensis (Dietrichson) van Uden et Farinha ex van Uden et Buckley. Strains of this species were isolated on 3 occasions from human vaginas. This species differs from other Pichia species that assimilate glucose but not galactose, sucrose, maltose, lactose, D-mannitol and D-glucitol by assimilating cellobiose.  相似文献   

20.
Ormia depleta(Wiedemann) (Diptera: Tachinidae), native to Brazil, is a parasitoid of someScapteriscusspecies (Orthoptera: Gryllotalpidae). It was first cultured in a laboratory in Florida in 1987. Releases ofO. depletawere made againstScapteriscusmole crickets in all regions of Florida beginning in 1988. Establishment of populations was achieved at some, but not all, of the release sites. The two earliest-established populations were monitored using traps employing synthetic calling song of maleScapteriscusmole crickets, to which gravid female flies are attracted. Additionally, progeny of the released flies were trapped between 1988 and 1993 in 32 peninsular counties, including 15 counties in which no releases had been made. The most parsimonious explanation of the pathways of spread of the current population was inferred from trapping surveys, and this yielded the probable year of colonization for peninsular counties. Reports in successive years by golf course superintendents of damage by mole crickets showed that counties withO. depletapopulations had significantly less damage than did yet-uncolonized counties.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号