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1.
Defining the structure of irregular nucleic acids: conventions and principles   总被引:31,自引:0,他引:31  
The algorithm "Curves", that we have recently presented in this journal (J. Biolmol. Str. Dynam. 6, 63-91 (1988], is updated to take into account the conventions developed at the Cambridge meeting on DNA curvature (September 1988) and extended to the calculation of local parameters. In addition, the principles which govern the choices made in establishing the Curves algorithm are compared with the approaches adopted by other authors.  相似文献   

2.
Predation can be a major factor in recruitment success of yellow perch ( Perca flavescens Mitchitl). Trawl catches of age-0 yellow perch in western Lake Erie declined from 870·3 per trawling h in June to 3·3 per trawling h in late July 1988. Coincident with the decline in relative abundance of age-0 yellow perch we found large numbers of age-0 yellow perch in the stomachs of small walleyes ( Stizostedion vitreum Mitchill). From this evidence we hypothesized that predation by walleyes may have caused the demise of the 1988 year-class of yellow perch. We used a population and bioenergetics modelling approach to estimate the impact of walleye predation on the abundance of age-0 yellow perch. Modelling showed that 6·8 × 109 age-0 yellow perch that had attained 18 mm total length ( t.l. ), were eaten by small (age-2 and younger) walleye from June through July 1988. We estimated that walleye ate 28·4–89·7% of the yellow perch reaching 18 mm t.l. during 1988. The majority of this predation (77% of total) was by the abundant age-2 cohort of walleyes. We concluded that, even in a large system such as Lake Erie, predation can play a major role in structuring year-class strength of yellow perch and, thus, management of percid fisheries should be conducted on a fish-community basis.  相似文献   

3.
《Research in virology》1991,142(1):67-70
Following the Rift Valley fever (RVF) epizootic of 1987 in the Senegal River basin, 2 series of serosurveys were carried out. In 1988 and 1989, respectively, 303 and 331 randomly selected sheep and goats were investigated and sera tested for the presence of specific RVF-virus-neutralizing antibodies.In 1988, 24.4% of the sera was found to have anti-RVF neutralizing antibodies and in 1989, 19.3% was found. In 1988, we observed in the Dagana district, including the 1987 epizootic area, a significantly higher prevalence (71.1%) than in the two other more distant districts of Podor (21.5%) and Matam (9.7%). From 1988 to 1989, the antibody seroprevalence dropped significantly from 71.7 to 23.9% within the Dagana district. Young animals showed a significantly lower antibody prevalence (7.9%, N=114) than adults (25.3%, N=217).RVF virus circulated at low level in 1988–1989 without any epizootic manifestation. The population turnover generated an important non-immune population potentially at risk.  相似文献   

4.
Abstract

The algorithm “Curves”, that we have recently presented in this journal (J. Biolmol. Str. Dynam. 6, 63–91 (1988)), is updated to take into account the conventions developed at the Cambridge meeting on DNA curvature (September 1988) and extended to the calculation of local parameters. In addition, the principles which govern the choices made in establishing the Curves algorithm are compared with the approaches adopted by other authors.  相似文献   

5.
We examined the historical record of mountain pine beetle (Dendroctonus ponderosae Hopkins) activity within Yellowstone National Park, Wyoming, for the 25-years period leading up to the 1988 Yellowstone fires (1963–86) to determine how prior beetle activity and the resulting tree mortality affected the spatial pattern of the 1988 Yellowstone fires. To obtain accurate estimates of our model parameters, we used a Markov chain Monte Carlo method to account for the high degree of spatial autocorrelation inherent to forest fires. Our final model included three statistically significant variables: drought, aspect, and sustained mountain pine beetle activity in the period 1972–75. Of the two major mountain pine beetle outbreaks that preceded the 1988 fires, the earlier outbreak (1972–75) was significantly correlated with the burn pattern, whereas the more recent one (1980–83) was not. Although regional drought and high winds were responsible for the large scale of this event, the analysis indicates that mountain pine beetle activity in the mid-1970s increased the odds of burning in 1988 by 11% over unaffected areas. Although relatively small in magnitude, this effect, combined with the effects of aspect and spatial variation in drought, had a dramatic impact on the spatial pattern of burned and unburned areas in 1988.  相似文献   

6.
In this article we describe MS-EdSeq, an integrated system forfast and accurate gel reading combined with safe and automaticfile tranfer to an arbitrary host computer. The uniqueness ofMS-EdSeq is its way of forming a link between the interactivesequence editor on the PC and the potential of the minicomputeracting as a host, thus making optimal use of both systems. Thisis especially suited for the moderately sized research group,using DNA-sequencing as one of various biochemical methods,where PCs are already in use for other tasks and a minicomputeris available. The gel reading algorithm described is fast, accurateand simple and the file transfer relies on the safe and well-knownKermit programs. Received on July 7, 1988; accepted on November 15, 1988  相似文献   

7.
Isolation of a Specific Potato Tuber-Inducing Substance from Potato Leaves   总被引:2,自引:0,他引:2  
Potato tuberization is induced by an unidentified "tuberizationstimulus" which is produced in the leaves. Recently, we confirmedthe occurrence of two acidic substances in the leaves whichappear to be the stimulus (Koda and Okazawa 1988). We reporthere the isolation of one of the substances from potato leaves.The molecular weight of the substance is 388. The substanceis active in inducing tuberization in vitro at a concentrationof 0.01 mg- liter-11 (ca. 3 ? 10-8 M). (Received April 15, 1988; Accepted June 28, 1988)  相似文献   

8.
Summary Since 1982 we have been monitoring allergological pollen, by means of a Lanzoni pollen trap VPPS 2000. In 1988 we detected the ragweed pollen for the first time, and subsequently in 1989 and in 1990.In 1988 it had been monitored from 16/8 to 26/9 (highest concentration 66.5 gr/m3/24 h on 3/9), in 1989 from 7/8 to 23/9 (highest concentration 30.0 gr/m3/24 h on 10/9) and in 1990 from 3/8 to 23/9 (highest concentration 80.9 gr/m3/24 h on 2/9). During the same years the prick test for ragweed pollen turned out to be positive in 27 patients out of 1526 (1.76%) in 1988, in 25 patients out of 1517 (1.64%) in 1989 and in 56 patients out of 1614 (3.41%) in 1990.The presence of specific IgE turned out to be positive in 12 patients out of 189 (6.35%) in 1988, in 17 patients out of 195 (8.71%) in 1989 and in 22 patients out of 230 (9.56%) in 1990.During out 3-years investigation, on the basis of the severity of symptoms and of the possible multi-sensitization, only 2 patients have undergone a specific immunotherapy to ragweed pollen.Our data confirm the presence of ragweed pollen in Lombardy, even if the sensitization is low in our population and the clinical significance of ragweed pollinosis is even lower.Nevertheless the high sensitizing power of this pollen makes a higher incidence of ragweed pollinosis possible in coming years.  相似文献   

9.
From 1986-90 we tagged 98 harbour seal pups at Hvaler, Norway Fifteen were recovered later the same year of which 10 were recovered in 1988, when the seal population was infected by a morbillivirus The epizootic in 1988 resulted in a population decline of c 75% Predicted birth weight did not vary significantly before and after the epizootic Newborn harbour seals have antibodies against the morbillivirus two years after the outbreak of the disease  相似文献   

10.
We examined the effect of ovule position within the ovary on the probability of seed maturation, on seed weight, and on progeny performance in the outbreeding legume Phaseolus coccineus. Ovaries of P. coccineus possess six linearly arranged ovules (ovule position one = stylar end). We found that in both 1987 and 1988, ovule position had a significant effect on the probability of seed maturation under field conditions. In 1987, ovule positions one. two, and three had a higher probability of maturing seeds than the three most basal ovule positions. In 1988, the probability of producing a mature seed in ovule position one was more similar to the three most basal ovule positions than to ovule positions two and three. The position of the ovule in the ovary had no significant effect on seed weight in 1987, but it had a significant effect in 1988. Overall, seeds from ovule positions one, two, and three tended to produce heavier seeds than the three most basal ovule positions. The effects of ovule position on progeny performance were determined in a greenhouse and a field study. In the greenhouse study, we found no significant overall effect of the position of the ovule that produced the seed on progeny performance. In the field study, we did find a significant ovule position effect on several measures of reproductive performance as well as an overall effect on reproductive performance. In addition, we found a significant interaction between ovule position and number of seeds per fruit. Progeny from the stylar end of the fruit outperformed the progeny from the peduncular end in fruits containing many seeds, whereas there were no significant differences between progeny produced in the stylar and peduncular ends of fruits containing few seeds. Causes of position effects are unknown but hypotheses abound.  相似文献   

11.
Summary A number of parameters characteristic of the wing margin precursor in imaginal discs of Drosophila are known: the zone of non-proliferating cells or ZNC (O'Brochta and Bryant 1985), aldehyde oxidase (AO) and other enzyme staining patterns (Sprey et al. 1982), E1C antigen localization in a narrow band along the margin (Piovant and Lena 1988). To test our hypothesis that such parameters, and others, act in concert to determine margin identity and the positional information that specifies the bristles and hairs appropriate to the anterior, posterior and distal margins, we have examined these parameters in the dominant mutant Lyra, in which much of the anterior and posterior margins is missing. After establishing that Lyra phenotype is already evident in the early pupal wing, we tested the known imaginal disc parameters and found that only Mab E1C (Piovant and Lena 1988) distribution differs from wild type, suggesting that E1C antigen may be a component of positional information. Sibatani's (1983) model for specification of positional information (PI) applied to wing discs predicts the Lyra adult wing shape as well as the reduced distribution of E1C antigen in Lyra wing discs. The model is based on the assumption that specification of positional information depends on interactions of multiple, independent factors. Clonal analysis with shaggy (Simpson et al. 1988 and Ripoll et al. 1988) indicates that factors in addition to E1C antigen contribute to margin PI in Lyra wings and should allow us to test the multi-component hypothesis further.  相似文献   

12.
Book Reviews     
《Freshwater Biology》1989,22(3):495-495
Evans, M.S. (ed.) (1988) Toxic Contamination and Ecosystem Health: A Great Lakes Focus.
Kelly, M. (1988) Mining and the Freshwater Environment.
Chart, T.E. and Bergerson, E.P. (1988) Methods for long-term identification of Salmonids: a review.
Gilderhus, P.A., Dawson, V.K. and Allen, J.L. (1988) Deposition and persistence of rotenone in shallow ponds during cold and warm seasons.
Hunn, J.B. (1988) Field assessment of the effects of contaminants on fish.
Jennings, D.P. (1988) Bighead carp (Hypothalmichthys nobilis): a biological synopsis.  相似文献   

13.
Activities of glycolytic enzymes were determined in elutriation fractionated cultures of Saccharomyces cerevisiae grown on different carbon sources. Almost pure fractions of single cells at the G1 state of cell division were obtained for some of the growth conditions tested, whereas other stages were enriched in particular fractions. Specific activities of glucose-6-phosphate dehydrogenase and alcohol dehydrogenase were found to be constant during the cell cycle, as reported by van Doorn et al. (1988a), Journal of Bacteriology 170, 4808-4815, and (1988b), Journal of General Microbiology 134, 785-790. In contrast to the earlier reports, the activities of hexokinase, phosphofructokinase, pyruvate kinase and trehalase were also constant in different states of the cell cycle. For hexokinase and phosphofructokinase it was shown that the apparent specific activity in a cell-free extract strongly diminished when extracts contained less that 0.5-1 mg protein ml-1. In the experiments of van Doorn et al. (1988a) the protein content of the outer fractions was up to 20 times lower than that of the central fractions, suggesting an alternative explanation for the observed changes in enzyme activities during the cell cycle. Therefore, we want to rectify the observations presented by van Doorn et al. (1988a), and conclude that the activities of the glycolytic enzymes do not vary greatly during the cell cycle of S. cervisiae.  相似文献   

14.
作者对当前植物形态学中与维管植物的形态演化和起源有着十分密切关系的顶枝学说,中柱学说与子叶节区学说进行了全面研究。并结合半个多世纪以来国际上著名的植物系统学家的维管植物分类系统,反复进行了比较和研究,对其中认为不妥之处提出了我们的见解,具体反映在文后的“维管植物系统的系统发育图”中。  相似文献   

15.
The full genome sequence (19,177 bp) of an Indian strain (IND1988/02) of bluetongue virus (BTV) serotype 23 was determined. This virus was isolated from a sheep that had been killed during a severe bluetongue outbreak that occurred in Rahuri, Maharashtra State, western India, in 1988. Phylogenetic analyses of these data demonstrate that most of the genome segments from IND1988/02 belong to the major "eastern" BTV topotype. However, genome segment 5 belongs to the major "western" BTV topotype, demonstrating that IND1988/02 is a reassortant. This may help to explain the increased virulence that was seen during this outbreak in 1988. Genome segment 5 of IND1988/02 shows >99% sequence identity with some other BTV isolates from India (e.g., BTV-3 IND2003/08), providing further evidence of the existence and circulation of reassortant strains on the subcontinent.  相似文献   

16.
Traditional colorimetric protein assays such as Biuret, Lowry, and modified Lowry (U-1988) are unsuitable for colored biological samples. Here we describe an improved Lowry protein assay (U-2012), which utilizes stable reagents and offers enhanced sensitivity over the U-1988 assay. U-2012 circumvents interference from colored pigments and other substances (for example sugars) bound to perchloric acid (PCA) precipitated proteins by hydrogen peroxide (H2O2) induced oxidation at 50°C. Unused hydrogen peroxide is neutralized with sodium pyruvate before protein estimation for a stable end color. The U-2012 assay is carried out on the PCA precipitated protein pellet after neutralization (with Na2CO3 plus NaOH), solubilization (in Triton-NaCl), decolorization (by H2O2) and pyruvate treatment. Protein contents in red wine and homogenates of beetroot and blueberry are calculated from standard curves established for various proteins and generated using a rectangular hyperbola with parameters estimated with Microsoft Excel's Solver add-in. The U-2012 protein assay represents an improvement over U-1988 and gives a more accurate estimation of protein content.  相似文献   

17.
Books     
《Ibis》1989,131(3):451-458
Book reviewed in this article:
A ndrle , R.F. & C arroll , J.R. (eds) 1988. The Atlas of Breeding Birds in New York State.
B ergerud , A.T. & G ratson , M.W. (eds) 1988. Adaptive Strategies and Population Ecology of Northern Grouse.
C ooper , M.E. 1987. An Introduction to Animal Law.
G oriup , P.D. (ed.) 1988. Ecology and Conservation of Grassland Birds.
H udson , P.J. & R ands , M.R. 1988. Ecology and Management of Gamebirds.
J anssen , R.B. 1987. Birds in Minnesota.
J ones , P.H. 1988. The Natural History of Bardsey.
K ondratiev , A. YA. (ed.) 1988. Bulletin of the Working Group on Waders.
L ardelli , R. 1988. Atlante degli Uccelli Nidificanti net Mendrisiotto.
M arle , J.G. van & V oous , K.H. 1988. The Birds of Sumatra. B.O.U. Check-list No. 10.
P almer , R.S. (ed.) 1988. Handbook of North American Birds; Volumes 4 & 5: Diurnal Raptors.
R ose , M.R. 1987. Quantitative Ecological Theory: an Introduction to Basic Models.
S chleidt , V.M. (ed.) 1988. Der Kreis urn Konrad Lorenz.
S ick , H. 1985. Ornitologia Brasileira. 3rd edition. Vols I and II.
S ummers -S mith , J.D. 1988. The Sparrows.
S iokhin , V.D., C hernichko , I.I., A rdamatskaya , T.B. et al. 1988. Colonial Waterbirds in the Southern Ukraine: Charadriiformes.
T emple , S.A. & C ary , J.R. 1987. Wisconsin Birds: A Seasonal and Geographical Guide.
T rounson , D. & T rounson , M. 1987. Australia Land of Birds.
W oods , R.W. 1988. Guide to Birds of the Falkland Islands.  相似文献   

18.
The aim of this study was to assess trends in captive breeding of threatened and endangered bird species in British zoos. The measures we recorded were: 1) the total number of species held, 2) the percentage of species held that are listed in the IUCN Red List, 3) the percentage of endangered species breeding, and 4) the number of species in managed breeding programs. These data were gathered from the bird inventories of 10 representative British zoos for the years 1988 and 1997. The data for measures 1–3 were compared between the 2 years using a Wilcoxon matched‐pairs test. We found that the zoos maintained the same number of species (W=10.5; n=10; P=0.093; median=87.5 and 78 for 1988 and 1997, respectively). However, there was a significant increase in the number of birds held that fit each of the IUCN's conservation categories (Endangered: W=43.0; n=10; P<0.05, median=1.48 and 6.64 for 1988 and 1997, respectively; Vulnerable: W=53.0; n=10; P<0.05, median=3.33 and 10.05 for 1988 and 1997, respectively; and Rare: W=55.0; n=10; P<0.01, median=0.00 and 8.33 for 1988 and 1997, respectively). Overall, the percentage of threatened species kept in zoos increased from a median of 4.81 in 1988 to 25.02 in 1997. During this period there was an increase in the number of species in each category of the IUCN Red List. No difference was found in the number of threatened species breeding between 1988 and 1997. Zoo Biol 23:85–89, 2004. © 2004 Wiley‐Liss, Inc.  相似文献   

19.
David Penney 《Palaeontology》2001,44(5):987-1009
Trachelas poinari sp. nov. (Corinnidae), Miagrammopes sp. indet. (Uloboridae) and the first indisputable fossil Lycosidae (gen. et sp. indet.) are newly identified and described in Miocene amber from the Dominican Republic. The following are junior synonyms: Nops segmentatus Wunderlich, 1988 of N. lobatus Wunderlich, 1988 (Caponiidae); Azilia muellenmeisteri Wunderlich, 1988 of A. hispaniolensis Wunderlich, 1988 (Tetragnathidae); and Lyssomanes galianoae Reiskind, 1989 of L. pristinus Wunderlich, 1986 (Salticidae). The specimens described as Nops sp. (Caponiidae), Selenops beynai Schawaller, 1984, S. sp. 1, and S. sp. 2 (Selenopidae) by Wunderlich (1988) are unrecognizable as distinct species. The following new combinations are presented: gen. indet. clypeatus (Wunderlich, 1988) (= Anelosimus clypeatus ) (Theridiidae); Meioneta bigibber (Wunderlich, 1988) (= Agyneta bigibber ), M. fastigata (Wunderlich, 1988) (= Agyneta fastigata ), M. separata (Wunderlich, 1988) (= Agyneta separata ) (Linyphiidae); Enacrosoma verrucosa (Wunderlich, 1988) (= Cyclosa verrucosa ) (Araneidae); Pseudosparianthis pfeiferi (Wunderlich, 1988) (= Tentabunda pfeiferi ) (Sparassidae). Theridion wunderlichi nom. nov. is proposed as a replacement name for T. ovale Wunderlich, 1988 (nom. preocc.). The previously unknown male of Styposis pholcoides Wunderlich, 1988 (Theridiidae) is described. Additional features of Argyrodes crassipatellaris Wunderlich, 1988 (Theridiidae) are described; this species is transferred from the trigonum to the cancellatus species group. Nine specimens belonging to six previously described species, and six juvenile Selenops sp. (including one exuvium) are newly identified. These are the first fossil records of Trachelas, Enacrosoma and Pseudosparianthis, giving them stratigraphic ranges of 15–20 my; the genera Anelosimus, Cyclosa and Agyneta are unknown in the fossil record.  相似文献   

20.
Also received     
《Ibis》1989,131(3):459-460
A li , S. & R ipley S.D. 1987. Compact Handbook of the Birds of India and Pakistan together with those of Bangladesh, Nepal, Bhutan and Sri Lanka.
B ond , T.J. 1988. Birds, the Painting of Terance James Bond.
B ruun , B. & S ehhal , A. 1988. Birds of Prey in the Middle East (in Arabic).
C handler , W.J. (ed.) 1988. Audubon Wildlife Report 1988/89.
C ocker , M. & I nskip , C. 1988. A Himalayan Ornithologist. The Life and Work of Brian Houghton Hodgson.
D avison , G.W.H. & K iew , R. 1988. Malaysian Birds. Pp. 41. Kuala Lumpur: Malayan Nature Society. ISBN 967–999-06-4–8.
H jort , C, K arlsson J. & S vensson S. (eds) 1986. Baltic Birds IV. Var Fågelvärld, supplement no. 11.
L ow , R. 1988. Parrots, a Complete Guide.
M akatsch , W. 1987. Wir bestimmen die Vögel Europas. 5th edition.
M ierauskas , P. (ed.) 1988. Abstracts of the XII Eastern Baltic Ornithological Conference.
R aethel , H-S. 1988. Hühner-Vögel der Welt. 4th edition.
R hodes , R.J. 1988. Birds in the Doncaster District.
R ichards , A. 1988. Birds of the Tideline.
S tepnell , K. & D alby , J. 1988. Australia's Parrots.
Z oological R ecord : AVES vol. 124 section 18(1987/88) 1988.  相似文献   

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