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1.
A system for the assessment of potential for fireblight Erwinia amylovora activity (PFA), based on standard temperature and rainfall records, has previously been outlined. Here some recent modifications are described and the system is discussed more fully and tested for its ability to explain outbreaks of fireblight in different hosts in Kent, south-east England for the years 1955–76. In most cases, there was a satisfactory match between PFA patterns and recorded field outbreaks and incidents and it is concluded that warnings based on the system could have lessened risk of disease in some hosts in past years. In the short term (depending on the accuracy of weather forecasts) the system can be used predictively. Its use in this way is discussed together with underlying principles of some of the criteria used and possible ways in which the precision of the system might be improved.  相似文献   

2.
Weather and fireblight in England   总被引:1,自引:0,他引:1  
A method for assessing potential fireblight activity in the field in southeast England is described. It is based on potential doublings (PD), derived from in vitro growth rates of Erwinia amylovora at different temperatures, combined with a rain score (R) derived from daily precipitation values. Where the incubation period (I) was known, the coefficient of correlation between I/R and PD was 085 (P < 0–001). When I was regressed on PD and R, the multiple correlation coefficient was 0–97. The low level of fireblight in England precluded direct testing of the predictive value of the relationship between PD, I and R but its application to growing season weather of 1955-74 highlighted those years when fireblight activity was high in a particular host. Whilst within the range 65–86 oF (18–30 oC) there is good agreement between accumulated potential doubling values and accumulated degree days, the rain score would probably require modification in other climates.  相似文献   

3.
Aim Historical information about source populations of invasive species is often limited; therefore, genetic analyses are used. We compared inference about source populations from historical and genetic data for the oyster‐associated clam, Gemma gemma that invaded California from the USA Atlantic coast. Location Mid‐Atlantic (North Carolina, Maryland), Northeastern (New Jersey, New York, Massachusetts) and the California coasts (Elkhorn Slough, San Francisco Bay, Bolinas Lagoon, Tomales Bay, Bodega Harbor). Methods The documented history of transplantation of Eastern oysters to California was reviewed. Cytochrome c oxidase subunit I (COI) sequences from recent and archived clams were examined in a haplotype network. We used AMOVA to detect geographic genetic structure and a permutation test for significant reductions in diversity. Results Chesapeake Bay oysters were transplanted to New York prior to shipment to San Francisco Bay and from there to peripheral bays. Gemma in the Northeastern and Mid‐Atlantic regions were genetically differentiated. In California, populations in Bodega Harbor and Tomales Bay were genetically similar to those in the Mid‐Atlantic area while clams in San Francisco Bay, Elkhorn Slough and Bolinas Lagoon resembled populations in the Northeastern region. In California, genetic variation was not highest in San Francisco Bay despite greater magnitude of oyster plantings. Haplotypes varied over time in native and introduced populations. Main Conclusions Historical records and inferences from genetics agree that both Northeastern and Mid‐Atlantic regions were sources for Gemma in California. Only complex genetic hypotheses reconcile the strong segregation of haplotypes in California to the historical evidence of mixing in their proximate source (New York). These hypotheses include sorting of mixtures of haplotypes or selection in non‐native areas. Haplotype turnover in San Francisco and Massachusetts samples over time suggests that the sorting hypothesis is plausible. We suggest, however, that Gemma was introduced independently and recently to Tomales Bay and Bodega Harbor.  相似文献   

4.
Woodchuck hepatitis virus (WHV) infection is known to be endemic in areas of the mid-Atlantic states but is apparently absent from populations in New York and much of New England. Blood samples of 40 woodchucks (Marmota monax) from New York and from Delaware were examined by starch gel electrophoresis, and 18 monomorphic and six polymorphic protein-coding genetic systems were identified. Mendelian inheritance of variants of the six polymorphic systems was confirmed in 52 laboratory offspring of the original samples. Average heterozygosity of 0.066 in New York woodchucks and 0.039 in Delaware woodchucks were high values for mammals, although similar to those of other sciurids. Significant heterogeneity between samples from New York and Delaware woodchucks was observed at two loci (peptidase with glycyl leucine-4 and phosphogluconate dehydrogenase), suggesting that these populations were genetically distinct. Whether there are genetically determined differences in response to WHV infection remains to be determined experimentally.  相似文献   

5.
Previous reports hypothesized that introduced populations of the Asian sea anemone Diadumene lineata (Verill, 1870 (Presented 1869) Communications of the Essex Institution 6: 51–104), which reproduces by fission, are often monoclonal or to be composed of few clones. To test this hypothesis, sea anemones were collected from thirteen sites in three non-native regions and one native region: Chesapeake Bay, New England, central California, and Japan. The internal transcribed spacer (ITS) region separating nuclear ribosomal RNA genes was amplified from each individual using PCR and surveyed for DNA sequence variation using single strand conformational polymorphism analysis (SSCP). Fifty-six distinct electrophoretic banding patterns were found in 268 anemones, and each pattern was considered a different genotype. The number of genotypes in a population ranged from one to thirteen. Only one sample (York River, Chesapeake Bay, n = 10) was monoclonal, although six populations were dominated (>50%) by single genotype. Only four genotypes were found in more than one population, and these were confined to single regions. Walker Creek, California was sampled in 1995 and 1997 and no genotypes were found in both years, suggesting rapid shifts in genotype frequency. We conclude that multiple genotypes of D. lineata have invaded North America and that the primary importance of clonal growth for introduced populations is the production of colonizing propagules.  相似文献   

6.
Benito C. Tan 《Brittonia》1990,42(1):50-55
The bryophyte portion of the Wabash College Herbarium (WAB) consists of the personal herbaria of two faculty members: Drs. R. L. Laubengayer and A. R. Bechtel. Together, there were 1483 packets of bryophyte specimens. Most of the collections are from New York, Indiana, and Puerto Rico. Among them, ten represent new county records for New York mosses.Pseudocrossidium aureum is reported as new to California.Orthotrichum sordidum andPylaisiella selwynii are newly identified from a Puerto Rican collection by Laubengayer. The West Indian records of these two species, however, are only doubtfully accepted. In addition, a short biographical sketch is presented for R. L. Laubengayer.  相似文献   

7.
Hair in African Art and Culture. The Museum for African Art, New York, February 9–May 28, 2000 (review venue); Apex Museum, Atlanta, July–September 2000; Cantor Center for Visual Arts, Stanford University, Palo Alto, California, October–December 2000; Museum of African American History, Detroit, January–April 2001; California African American Museum, Los Angeles, May–August 2001.
Hair in African Art and Culture. Roy Sieber and Frank Herreman. eds. New York: The Museum for African Art; Munich, London, New York: Prestel, 2000. 192 pp.  相似文献   

8.
Although matings between relatives can have negative effects on offspring fitness, apparent inbreeding preference has been reported in a growing number of systems, including those with documented inbreeding depression. Here, we examined evidence for inbreeding depression and inbreeding preference in two populations (Clinton, New York, and Davis, California, USA) of the cooperatively breeding American crow (Corvus brachyrhynchos). We then compared observed inbreeding strategies with theoretical expectations for optimal, adaptive levels of inbreeding, given the inclusive fitness benefits and population‐specific magnitude of inbreeding depression. We found that low heterozygosity at a panel of 33 microsatellite markers was associated with low survival probability (fledging success) and low white blood cell counts among offspring in both populations. Despite these costs, our data were more consistent with inbreeding preference than avoidance: The observed heterozygosity among 396 sampled crow offspring was significantly lower than expected if local adults were mating by random chance. This pattern was consistent across a range of spatial scales in both populations. Adaptive levels of inbreeding, given the magnitude of inbreeding depression, were predicted to be very low in the California population, whereas complete disassortative mating was predicted in the New York population. Sexual conflict might have contributed to the apparent absence of inbreeding avoidance in crows. These data add to an increasing number of examples of an “inbreeding paradox,” where inbreeding appears to be preferred despite inbreeding depression.  相似文献   

9.
Slow-growing bacteria similar to the bacterium causing lettuce corky root (CR) in California (strain CA1) were isolated from muck soils of Florida, New York, and Wisconsin, using lettuce seedlings as bait. All strains were tested for reaction with polyclonal antibodies produced against strain CA1 and for pathogenicity on CR-susceptible (Salinas) and CR-resistant (Green Lake) lettuce cultivars in a greenhouse. Five strains from Florida, three from New York, and three from Wisconsin induced severe CR symptoms on Salinas and mild symptoms on Green Lake. All strains were gram-negative, aerobic, oxidase positive, and catalase positive and reduced nitrate to ammonia. Whole-cell fatty acid compositions were similar for all strains and resembled that of Pseudomonas paucimobilis. Since this fatty acid pattern is unique, it is suggested that CR of lettuce is caused by strains of the same bacterium in Florida, New York, Wisconsin, and California.  相似文献   

10.
Reduced genetic diversity due to founder effects often is expected for invasive populations. The present study examined two nuclear gene regions and one mitochondrial gene to evaluate the origins and genetic diversity of Gemma gemma, a ‘stow-away’ that was introduced to California more than 100 years ago with the importation of the Eastern oyster, Crassostrea virginica, from the United States’ Atlantic coast. A previous investigation involving mitochondrial DNA cytochrome-c-oxidase subunit I sequences reported no significant difference in haplotype diversity between the native and introduced populations; however, estimates of allelic (or haplotypic) variability are insensitive to losses of rare alleles that may accompany founder events and population bottlenecks. Estimates of allele richness and the distribution of rare alleles provide more sensitive indicators of such events. The present investigation of introduced and potential source populations identified lower allele richness and number of singleton alleles in California samples. Atlantic coast Gemma exhibit a sharp phylogeographic transition between northeastern (New York through New England) and mid-Atlantic (southern New Jersey through Virginia) subpopulations, which appear latitudinally inverted for the California Gemma populations. These genetic results, and information from the transportation history of the Eastern oyster, help to clarify processes involved in the introduction of this invasive species.  相似文献   

11.
Habitat management recommendations are often based on best available science determined through retroductive and inductive hypotheses. Such recommendations are not frequently tested, potentially resulting in the implementation of unreliable practices for management of imperiled species. The New England cottontail (Sylvilagus transitionalis) is an imperiled shrubland-obligate species whose recovery efforts include habitat management and restoration. Researchers suggest former best management practices for the species may result in ecological traps and new recommendations have been developed. We evaluated these newly revised best management practices designed to retain higher tree canopy closure to promote New England cottontails without encouraging eastern cottontails (Sylvilagus floridanus). We compared New England and eastern cottontail density between management plots (tree canopy thinned with all downed trees left on the ground, with or without invasive shrub treatment) and control plots (unmanaged) and examined the influence of management on resource selection and survival. Management strategies retaining higher canopy closure promoted stronger selection by New England cottontails than by eastern cottontails. Catch per unit effort of New England cottontails was greater than for eastern cottontails in management plots (P = 0.002). For both species, the proportion of the 95% home range overlapping managed areas was greater than the proportion of managed area in the habitat patch; however, for the 50% core area of the home range, this was only true for New England cottontails. When post-treatment canopy cover was >75%, New England cottontails selected canopy-thinning treatments without invasive shrub removal over unmanaged areas, but selection by eastern cottontails was unaffected by management treatment or canopy cover. Survival probability of both species was high and uncorrelated with time spent in management areas. Survival probability decreased as the average distance a rabbit moved in a 7-day period increased. Our results illustrate the need to revise management strategies that emphasize eliminating canopy cover when improving New England cottontail habitat is an objective, particularly where they are sympatric with eastern cottontails.  相似文献   

12.
Members of the committee were Dorothea Bennett (Chairman), Department of Zoology, University of Texas, Austin (deceased); Linda C. Cork, Division of Comparative Medicine, Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, Maryland; Thomas J. Gill III, Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania; Jon W. Gordon, Department of Obstetrics and Gynecology, Mt. Sinai School of Medicine, New York, New York; Andrew G. Hendrickx, California Primate Research Center, University of California, Davis, California; Larry E. Mobraaten, The Jackson Laboratory, Bar Harbor, Maine; and John L. VandeBerg, Department of Genetics, Southwest Foundation for Biomedical Research, San Antonio, Texas.  相似文献   

13.
Abstract. We investigated the identity and distribution of members of the Culicoides variipennis complex in the six New England states of the U.S.A., a region where bluetongue transmission has not been detected. Analyses of seven polymorphic isozyme-encoding loci showed that only C.v.variipennis , not considered to be a vector of the bluetongue viruses, was present. The populations of C.v.variipennis were significantly more hetero-zygous than C.v.sonorensis and Cv.occidentalis populations from similar studies in the state of California. Estimates of genetic diversity among populations of C.v.variipennis in New England were similar to C.v.sonorensis in the state of Colorado, but were significantly more genetically divergent than California populations of Cv.occidentalis. The impact of these findings on the status of New England as a possible bluetongue-free region for the purpose of international trade in ruminant livestock and their germplasm is discussed.  相似文献   

14.
Kellington, S. H., and A. C. Mitchell An Evaluation of New Science Worksheets for Scottish Integrated Science London: Heinemann Educational Books, 1978 136 pp. $9.50 paper. Reviewed by Howard J. Stein

Sullivan, Dennis Lots of Dots: Learning with Coordinate Pictures Designed by and for Children Berkeley: Lawrence Hall of Science, University of California, 1977 48 pp. $2.50 softcover. Reviewed by John G. Harvey

Parker, Stephen Life before Birth: The Story of the First Nine Months Published with the British Museum (Natural History) New York: Cambridge University Press, 1979 48 pp. $6.95 hardcover, $2.50 paper. Reviewed by Donald J. Nash

Anderson, Norman D. Investigating Science in the Swimming Pool and Ocean New York: McGraw-Hill Book Co., 1978 175 pp. $7.95. Reviewed by Julian R. Brandou

Selsam, Millicent Tyrannosaurus Rex New York: Harper &; Row, 1978 41 pp. $5.95. Reviewed by George R. Zug

Freeman, W. H., and Brian Bracegirdle An Atlas of Embryology, 3d ed. London and Exeter, N. H.: Heinemann Educational Books, Inc., 1979 94 pp. $10.00 cloth. Reviewed by Joseph Patrick Kennedy  相似文献   

15.
Believing Identity: Pentecostalism and the Mediation of Jamaican Ethnicity and Gender in England. Nicole Rodriguez Toulis. New York: New York University Press, 1997.304 pp.  相似文献   

16.
Abstract: A cohort of rhesus macaques (Macaca mulatta), obtained from the California Regional Primate Research Center (CRPRC) and necropsied in 1970–72 with lesions suggestive of simian immunodeficiency virus (SIV) infection, was identified at the New England Regional Primate Research Center (NERPRC). Polymerase chain reaction (PCR), DNA sequence analysis, and in situ hybridization were used to confirm the presence of SIV nucleic acids. This represents the earliest case of SIV infection at the NERPRC and suggests a common source for present day SIV isolates.  相似文献   

17.
ABSTRACT Managers and other stakeholders may rely on wildlife-related risk communication campaigns to prevent or reduce risks associated with human-wildlife conflict. The operating environment or the sphere of activity within which a campaign functions can influence a campaign's ability to achieve outcomes. Between 1 May 2005 and 30 October 2005, we studied human-black bear conflict in southeastern New York and the wildlife-related risk communication campaign, the New York NeighBEARhood Watch (NYNW). Based on the social amplification of risk framework, our goal was to determine whether mass media affected the operating environment of the campaign, and if so, identify the magnitude and direction of the effect. We used a self-administered mail survey (N = 2,800) in 4 southeastern New York, USA, towns to collect data about residents’ perceived black bear-related risks, bear-related behavior, and exposure to the NYNW. We also conducted a content analysis of mass media coverage about black bears. Exposure to the NYNW from newspapers was positively correlated (R = 0.39, P < 0.01) with respondents’ decreased acceptance of black bear-related risks. Our results showed a small social amplification of risk associated with black bears from exposure to mass media, specifically newspapers. Mass media can influence the operating environment of a wildlife-related risk communication campaign, including through amplification of risk perception. Characterizing the operating environment of campaigns is key to HWC-intervention planning, evaluation, and policy. Wildlife practitioners can consider media effects, as well as other biological and social factors, as potential influences on a campaign's operating environment and be aware that interaction effects may occur.  相似文献   

18.
Book reviews     
Andrea de Guttry and Natalino Ronzitti, eds. The Iran‐Iraq War (1980–1988) and the Law of Naval Warfare. 1993. Cambridge, England: Grotius Publications. 573 pp. ISBN 1–857010–13–2. (Available from Cambridge University Press, Cambridge, England, and New York, NY, ISBN 0–521–463025, $190)

David L. Larson. Security Issues and the Law of the Sea. 1993. Lanham, MD: University Press of America. 382 pp. ISBN 0–8191–9089–6. $47.50  相似文献   

19.
Buds of Claytonia virginica were examined from 9 locations in the metropolitan New York area. A large amount of meiotic irregularity was characteristic of the populations studied. Chromosome counts on pollen mother cells were higher than any reported previously for the taxon, which contains an extensive aneuploid series including at least 40 different numbers ranging from 2n = 12 to ca. 190. In one New Jersey population, plants having approximately 90 chromosomes were associated with those having only 16. All the observations indicated that Claytonia virginica is an unusual species with an ability to tolerate fluctuations in chromosome material without apparent effects on fertility and morphology.  相似文献   

20.
The invasive ascidian, Didemnum sp. A, first appeared in New England bays and harbors in the early 1990s, and in the waters around Cape Cod in 1993. While ship traffic was the likely vector introducing the species, its origin and precise date and location of its introduction are presently unknown. Colony surfaces of Didemnum sp. A appear very clean and not favorable substrates for epibiota settlement, but closer inspection revealed the presence of benthic foraminifera. During 2003 and 2004, 52 samples of Didemnum sp. A and other ascidians were collected to determine whether or not the foraminiferal assemblages might also be non-native and thus provide a potential clue to the place of origin of Didemnum sp. A. Sample locations included the New England coast from Connecticut to Maine (with a concentration in the Cape Cod area), northern California, Zeeland, The Netherlands, and Shakespeare Bay, New Zealand. From New England samples, 18 species of benthic foraminifera were identified. The most common species represented were Cornuspira involvens, C. planorbis, Elphidium galvestonense, E. margaritaceum, Glabratellina lauriei, Miliolinella subrotunda, Quinqueloculina bicornis, and Rosalina floridana. Foraminiferal assemblages on Didemnum sp. A from other regions sampled were composed of the same cosmopolitan species found in New England, plus other species which were indigenous to each region. Because no exotic foraminifera species were found it is concluded that Didemnum sp. A likely did not introduce non-native foraminifera originating from their native habitats into the New England region.  相似文献   

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