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1.
A microcomputer program which locates tRNA genes within longDNA sequences is described. The search is performed either byidentifying tRNA-like secondary structures or by locating eukaryoticRNA polymerase III promoter consensus sequences. The programis also useful in finding inverted repeats allowing the formationof stem-loop secondary structures in tRNA. The program has beendeveloped in BASIC and 6502 Assembler and runs on the AppleII plus and He microcomputers. The execution is quite fast;all the operations are carried out in 190 s, dependingon the required task and on the sequence length.
Received on March 1, 1985; accepted on April 25, 1985 相似文献
2.
A general purpose non-linear curve fitting program for the British Broadcasting Corporation Microcomputer 总被引:2,自引:0,他引:2
Software for nonlinear curve fitting has been writtenin BASIC to execute on the British Broadcasting CorporationMicrocomputer. The program uses the direct search algorithmPatternsearch, a robust algorithm that has the additionaladvantage of needing specification of the Junction without inclusionof the partial derivatives. Although less efficient than gradientmethods, the program can be readily configured to solve lowdimensionaloptimization problems that are normally encountered in lifesciences. In writing the software, emphasis has been placedupon the user interface and making the most efficientuse of the facilities provided by the minimal configurationof this system.
Received on March 4, 1985; accepted on March 14, 1985 相似文献
3.
An algorithm and a program have been developed which enableoptimal alignments of biological sequences on an 8bitmicrocomputer. The compiled program can process sequences upto 1000 residues on a Commodore 64. Since this program was writtenoriginally in the BASIC language, it may readily be adaptedto other microcomputers with small changes.
Received on March 11, 1985; accepted on March 14, 1985 相似文献
4.
We present an algorithm for prediction of RNA secondary structures.The program consists of three parts: the first computes locationand free energy of every possible stemloop structure,the second computes probability of its formation, and the thirdlists the positions and free energies of all the stemloopsin the order of their probability sizes. The circular RNA moleculeof chrysanthemum stunt viroid was used as an input data fordemonstrating the operation of the program.
Received on March 14, 1985; accepted on March 18, 1985 相似文献
5.
Gonadal changes in two species of Cerastoderma occurring indiscrete populations in South Wales were monitored by stereologicalanalysis during the breeding seasons of 1981 and 1982. Fecundityand spawning efficiencies were determined quantitatively. Therelationship between reproductive activity and changes in meatcondition are discussed. Both species are opportunistic breeders. Their normal patternsof reproduction are similar, consisting of minimum activityin winter and peak activity during spring/early summer. Thetwo species were affected differently by the severe winter of198182C. glau-cum exhibited a single, epidemicspawning and resumed gametogenesis after a 4-month resting period.C. edule adopted a polycyclic pattern withouta resting period. Both of these unusual reproductive strategies,augmented by reduced predation resulted in heavy spatfalls. (Received 20 March 1985; revised 20 March 1985; 相似文献
6.
Taylor Philip; Rosenberg Paul; Samsonova Mary.G. 《Bioinformatics (Oxford, England)》1991,7(4):495-500
We describe a fast computer algorithm for identifying consensuspatterns in DNA sequences. The method requires no prior assumptionsabout the consensus pattern other than its length. In particularno previous knowledge of the frequency or spacing of consensuspatterns is required. However, a priori information about theshape of the consensus pattern, or invariability of individualpositions, or the overall conservation level, can be utilizedto enhance the selectivity and sensitivity of search. As thenumber of all possible consensus words increases very rapidlywith length, comprehensive searches have usually been restrictedto a maximum of 1012 nucleotides, even when large mainframesare used. Our algorithm enables searching for consensus patternsof this order on current mid-range and powerful microcomputers.Searches may be conducted on single, long sequences or a setof possibly aligned shorter sequences. We give examples of identifiedconsensus patterns in both prokaryotic and eukaryotic DNA sequences,along with some typical program timings.
Received on January 14, 1991; accepted on March 5, 1991 相似文献
7.
Phytoplankton studies in the fjords of West Spitzbergen: physical environment and production in spring and summer 总被引:1,自引:0,他引:1
The phytoplankton in the fjords of West Spitzbergen was investigatedfrom 1978 to 1985. The spring bloom lasted longer than at theNorwegian coast: from mid March to early June. There is no delayin the onset of the spring bloom in Spitzerbergen fjords relativeto fjords of northern Norway. This is probably related to therapid daylength increase at high latitudes. The phytoplanktonspecies composition during spring was comparable to that alongthe coast of northern Norway. Annual primary production in theinvestigated area was calculated to be 150 g C m2 year1. 相似文献
8.
Since its fust record in Icelandic waters in 1970, Praunus flexuosushas been found to be very common in the littoral zone of theAtlantic water at the south-west coast of Iceland. It seemspossible that P. flexuosus has only recently been introducedinto Icelandic waters. The life history of P. flexuosus hasbeen followed in Skerjafjord, near Reykjavik, in 19851986.The animals have a one-year life span. The females, some ofwhich appear to produce three broods, breed mainly during JuneAugust.Breeding females ranged in length from 18.7 to 25.7 mm and thelargest brood was 72 eggs. The incubation time at c. 11°Cwas estimated to be 25 days. The daily growth rate of juvenileswas estimated to be 0.16 mm in JulyAugust and 0.050.07mm in SeptemberOctober. No growth occurred during thewinter months of OctoberMarch. 相似文献
9.
Peptides that participate in the oxidizing side of PS II wereselectively tagged with iodine, activated by illuminated Tris-treatedthylakoids. A peptide of 29 kDa was iodinated, with less labelingof 33- and 58-kDa peptides. The iodination was inhibited byDCMU, and suppressed when the Tris-treated thylakoids were supportedby diphenylcarbazide. No peptide in the untreated thylakoidswas iodinated. These findings indicate that the oxidation ofI at the oxidizing side of photosystem II results iniodination. The iodinated peptide of 29 kDa was identified to be one ofthe major components of the isolated PS II reaction center complexfrom the following characteristics of the peptide: 1) polymerizationon heat-treatment (95C, 5 min) of the iodinatcd thylakoidsin the presence of SDS and 2-mercaptoethanol, 2) thylakoid-bindingafter NaSCN-washing, and 3) migration distinct from that ofthe herbicide-binding protein in SDS-polyacrylamide gel electrophoresis.Thus, the iodinated 29-kDa peptide is a secondary electron donorof PS II or the nearest one to a site where I is oxidized. (Received March 13, 1985; Accepted June 5, 1985) 相似文献
10.
Vegetative shoots from the base of the crown, and from partsof the tree likely to form male or female buds, were collectedfrom 40yearsold trees of Picea sitchensis (Bong.)Carr. throughout the 19734 annual growth cycle. The morphologyand growth rates of the terminal buds on these shoots were assessed. Bud scale primordia were formed most quickly in the female position,at an intermediate rate in the male position and most slowlyin the basal vegetative position during April, May and June.In July and early August the apical meristems swelled to formdomes and continued to grow at the same relative rates in themale, female and basal vegetative positions. Reproductive budswere first morphologically distinct in late August and sporangiaappeared in October. Dormancy, defined by the pause in apicalvolume increase, extended from mid-October to midMarch.Young strobili grew much faster than basal vegetative shootsof the same age between midMarch and bud burst in lateApril. Throughout the growth cycle, external changes in budsize reflected changes in size of the apical meristem, youngstrobihis or young vegetative shoot inside the bud. It is proposed that the rate of growth of an apical meristemmay be causally related to the type of bud which subsequentlydevelops from it. Sitka spruce, Picea sitchensis, bud development, morphology, growth of apical dome, flowering 相似文献
11.
Three programs useful for the investigation of steadystatekinetics have been developed. Two provide the solution to thesteadystate rate equation; the first of these is a straightforwardimplementation of the rules developed by Chou. The second isa very efficient procedure for evaluating KingAltmandiagrams and can be used for quite large mechanisms. The thirdprogram provides the numeric solution for a specific mechanismand set of initial conditions; it is well suited to extremelylarge models.
Received on April 1, 1985; accepted on April 19, 1985 相似文献
12.
A simple device was developed to detect net ion efflux duringa single action potential of Chara as an increase in the electricconductance of the bathing solution. The device showed a sufficientlyhigh sensitivity and rapid response to the increase in the electricconductance. Net efflux of monovalent ions was estimated as65660 pmol cm2 impluse1 (average 220 pmolcm2 impulse1). (Received June 28, 1985; Accepted November 13, 1985) 相似文献
13.
The response of individual Cryptomonas cells to continuous lightwas recorded using infrared video-micrography. Swimming directionsand temporal shifts in swimming direction of each cell weremeasured. White light of 0.11 W m2 elicited apositive phototactic orientation, but did not induce any photophobicresponse. Light of 100 W m2 induced a photophobic responseat the onset of actinic irradiation, but did not induce positivephototactic orientation. No correlation between positive phototacticorientation and photophobic response was found in this species.The direction toward the light source was defined as 0°,and the direction away from the source as 180°. Within 2s after the onset of lateral monochromatic light of 570 nm at0.1 W m2, cells which were swimming in a direction ofless than 120° predominantly shifted their course towardthe light source. Cells swimming in directions of larger than120° shifted their course as randomly as those in the dark.Thus, for phototactic orientation, the cells must perceive thelight from their anterior side. (Received July 29, 1985; Accepted November 4, 1985) 相似文献
14.
Kikunaga Shigeshi; Takahashi Masayuki; Huzisige Hirosi 《Plant & cell physiology》1985,26(7):1323-1330
We developed an accurate and simple method for measuring thephytic acid contents in cereal grains on the basis of closeexamination of various factors affecting the accuracy and reproducibilityof the measurement. Our conclusions were: (1) As extracting medium for phytic acid,HCl was better than trichloroacetic acid or H2SO4. (2) The suitablepH range for extracting phytic acid was 0.3 to 1.0. (3) Completeformation of Fe-phytate required four to nine times as muchFe3$ as phytic acid. (4) No definite effect of Na2SO4 on therecovery of phytic acid was observed, though it increased theextracting efficiency of trichloroacetic acid. (5) The determinationlimit of phytic acid by the iron precipitation method was 3.3µmol per 20 ml. Our new method gave reliable results, and a linear relationshipof y=0.3163x$0.0597 was obtained up to 0.025 µmol µ1between the concentration of phytic acid and the zone lengthin isotachophoresis. The phytic acid contents of two kinds ofrice, two kinds of rye, and one kind of wheat and of barleywere determined with this method. (Received March 19, 1985; Accepted August 2, 1985) 相似文献
15.
Particulate and dissolved phytoplankton production of the Patos Lagoon estuary, southern Brazil: comparison of methods and influencing factors 总被引:3,自引:0,他引:3
Abreu Paulo C.; Odebrecht Clarisse; Gonzlez Adriana 《Journal of plankton research》1994,16(7):737-753
Uptake rates of 14C (filtration and the acidification-bubblingmethodABM) were measured weekly in a shallow region ofthe Patos Lagoon estuary (3207'S, 5206'W) between March 1989and March 1990. Phytoplankton production varied seasonally,the lowest values occurring in the austral winter (JuneAugust1989) and the highest rates during spring and summer (March1989; September 1989March 1990). Particulate carbon productionvaried between 0.65 and 70.6 mg C m3 h1 and wasmostly associated with organisms <20 µm (mean = 73.4%).Dissolved organic carbon (DOC) released by phytoplankton variedbetween 0.1 and 89.3 mg C m3 h1 representing 相似文献
16.
An enzyme, which catalyzes the formation of dihydrofolate fromdihydropteroic acid and L-glutamic acid, was found in pea seedlings.The enzyme was purified approximately 25-fold from the crudeextracts of pea seedlings, and its some properties were investigated.Optimum pH for the enzyme activity was found to be 8.8. Pteroicand tetrahydropteroic acids were not active as substrate. Theenzymatic reaction required as cofactors ATP, divalent (Mg2+or Mn2+) and univalent (K+, NH4+ or Rb+) cations. The productwas characterized as dihydrofolic acid by bioautography. MICHAELIS constants for L-glutamic acid, ATP, dihydropteroicacid and Mg2+ were 7.0x104, 9.0x105, 3.5x106and 1.2x103 M, respectively. The MICHAELIS constant forMn2+ was 3.0x104. The enzyme was inhibited by PCMB orsilver nitrate and, to some extent, by L-aspartic acid. Inhibitionby PCMB was completely reversed by addition of 2-mercaptoethanol.Enzyme activity was distributed widely among plants. The importanceof magnesium and potassium ions for enzyme catalysis is discussed.
1For the previous paper, Part V, see Reference (30). (Received March 28, 1970; ) 相似文献
17.
Green, C. F., Dawkins, T. C. K. and McDonald, H. G. 1985. Influenceof chlorocholine chloride on grain growth of winter barley (Hordeumdistichon L. cv. Igri) in the field.J. exp. Bot. 36:11261133. Chlorocholine chloride was applied to winter barley either inthe Spring or Autumn. It increased grain number per unit croparea. Rates of incorporation of dry matter into the grain weredecreased, but the period of growth was extended by the treatments.Overall the final mean grain weight was reduced so that no advantagesin terms of yield resulted from the increased grain numbers. Key words: Chlormequat, chlorocholine chloride, CCC, Hordeum distichon L., barley, grain growth, grain weight, senescence, grain yield 相似文献
18.
Miyazaki Atsushi; Kobayashi Katsumi; Ishizaka Shozo; Fujii Tadashi 《Plant & cell physiology》1986,27(4):693-700
Phosphorus, sulfur, potassium and calcium were measured by particle-inducedX-ray emission (PIXE) in horizontally oriented, light-irradiatedor non-irradiated primary roots of Zea mays L., cv. Golden CrossBantam 70 which exhibit gravitropic response only after exposureto light. The content of the four elements increased in thelower half of horizontally oriented roots which had been brieflyexposed to white or red light, while there were no marked differencesin distribution between the upper and lower halves of non-irradiatedroots. The increase of each element in the lower half was observed1530 min after irradiation in root caps and 3060min after irradiation in the elongation zones. The effect ofred light was not reversed by far-red light given immediatelyafter the red irradiation. Ethylene glycol-bis(ß-aminoethylether)-N, N, N',N'-tetraacetic acid (EGTA) treatment of roottips inhibited the gravitropic curvature of roots, and the additionof Ca reduced this inhibition. The meaning of Ca redistributionin root caps and elongation zones during light-induced gravitropiccurvature of maize roots is discussed. (Received December 4, 1985; Accepted March 22, 1986) 相似文献
19.
Kermode, A. R. and Bewley, J. D. 1985. The role of maturationdrying in the transition from seed development to germination.II. Postgerminative enzyme production and soluble proteinsynthetic pattern changes within the endosperm of Ricinus communisL. seeds.J. exp. Bot. 36: 19161927. Immature seedsof Ricinus communis L. cv. Hale (castor bean) removed from thecapsule at 30 or 40 d after pollination (DAP) do not germinateunless first subjected to a desiccation treatment. This changefrom development to germination elicited by premature desiccationis also mirrored by a change, upon subsequent rehydration, inthe pattern of soluble protein synthesis within the endospermstorage tissue. Following rehydration of prematurely dried 30or 40 DAP seeds, soluble proteins characteristic of developmentcease to be synthesized after 5 h of imbibition, and those uniquelyassociated with germination and growth are then produced. Apattern of soluble storage protein breakdown comparable to thatfound in endosperms from mature seeds following imbibition isalso observed. In contrast, hydration of 40 DAP seeds immediatelyfollowing detachment from the mother plant results in a continuationof the developmental pattern of protein synthesis. Prematuredesiccation at 40 DAP elicits the production within the endospermof enzymes involved in protein reserve breakdown (leucyl ßnaphthylamidase;LeuNAase) and lipid utilization (isocitrate lyase; ICL) to levelscomparable to those observed in maturehydrated endosperms.It is proposed that drying plays a role in redirecting metabolismfrom a developmental to a germinative mode; it also appearsto be a prerequisite for the induction of hydrolytic enzymesessential to the postgerminative (growth) phase of seedlingdevelopment. Key words: Desiccation-tolerance, germinability, seed development, castor bean 相似文献
20.
Enhancement of Oxygen-Evolution in Photosystem II-Phycobilisome Particles from Porphyridium cruentum
Oxygen-evolving photosystem II-phycobilisome particles froma red alga were inhibited 5080% by aging, dilution, lowpH and salt-washing. Bovine serum albumin, and dithiothreitolwere found to stimulate activity in all but salt-washed particles.CaCl2 and MnCl2 partially restored activity lost after agingor dilution.
1Current address: Waksman Institute of Microbiology, RutgersUniversity, Piscataway, New Jersey 08854-0759, U.S.A. (Received October 5, 1985; Accepted March 31, 1986) 相似文献