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1.
A. Vilenkin 《Biopolymers》1977,16(8):1657-1675
A new technique is presented for treating the ground state of an heteropolymer with a random sequence of components. An exact system of equations is found for determining the ground state energy E which is equal to the polymer free energy f in the lowest-order approximation in T/V (V/2 is the large “surface” energy arising at the boundaries between coiled and “helical” sections: V ? T, Uk; U1 and –U2 are the free energies of the components counted from the corresponding coiled state energies). These equations are essentially simplified at certain fixed values of the ratio U1/U2. For integer values of U2/U1 and U1/U2 a solution is obtained with an accuracy exp(–V/Uk). The ground-state energy as a function of U1 and U2 is shown to be highly irregular: its derivatives have jumps at an infinite number of points. These jumps provide a fine structure of the melting curves. A smoothed over the jumps function E′ is found by way of analytic continuation from the integer values of U1/U2 and U2/U1. The accuracy of the approximation fE is estimated and the correctional term of order T/V is determined.  相似文献   

2.
The implication of state space structure on the existence of a repeatable experimentE designed to determine if a statesL has propertyP or notP is investigated. It is shown that if a state spaceL is connected, then no experimentE is repeatable. This formalism is used to demonstrate that if a propertyP has an associated set of points inL which is dense with dense complement inL, then there exists no repeatable experimentE which can be used to test whethers has propertyP or notP. Other consequences of this formalization are discussed.  相似文献   

3.
All known Queensland species of the isopod family Sphaeromatidae, subfamily Sphaeromatinae (= hemibranchs), are discussed. The following new taxa are erected: Calcipila cornuta, gen. nov., sp. nov. ; Cymodoce tribullis, sp. nov. ; Cymodoce bipapilla, sp. nov. ; Paracilicaea aspera, sp. nov. ; Cilicaeopsis glebosa, sp. nov. ; Cilicaeopsis furculata, sp. nov. ; Cilicaea calcarifera, sp. nov. ; Zuzara curtispina, sp. nov. ; Zuzara digitata, sp. nov. ; and Clianella brucei, sp. nov. Exosphaeroma intermedium Baker is transferred to the genus Sphaeroma Latreille. The genus Dynoides Barnard is reviewed and its current synonymy is contested. With several new records, this brings the total number of sphaeromatid species known from Queensland to 49, 24 of which are in the subfamily Sphaeromatinae. A checklist of all sphaeromatid species occurring in Queensland waters is given. From the rest of Australia: Cymodoce tuberculata Haswell is given the replacement name Cymodoce haswelli, nom. nov. ; Cymodoce granulata Miers is made a junior synonym of Cerceis trispinosa (Haswell) (subfamily Dynameninae); Zuzara diadema Leach, Z. dicantha (Milne Edwards) and Z. Integra Haswell are made junior synonyms of Z. semipunctata Leach; Cilicaeopsis dakini Tattersall is tentatively transferred to the genus Paracilicaea Stebbing. The genera discussed are reviewed world-wide and among the non-Australian species: Exosphaeroma papillae Bayliff is transferred to the genus Sphaeroma; Sphaeroma irakiensis Ahmed is made a junior synonym of Sphaeroma annandalei annandalei Stebbing; Cymodoce richardsoniae Nobili is shown to be distinct from Cymodoce truncata Leach; Cymodoce eupyga Nobili is transferred to the genus Paracilicaea; Dynoides amblysinus Pillai, Dynoides castroi Loyola e Silva and Exosphaeroma globicaudum (Dana) are transferred to the genus Clianella Boone; Dynoides brasiliensis (Loyola e Silva; and Sphaeroma savignn Milne Edwards sensu Dana, 1853 are declared to be conspecific with Clianella castroi. The name Sorrentosphaera Verhoeff is made a junior synonym of Dynamene Leach (subfamily Dynameninae.  相似文献   

4.
Summary T(Y;2) translocations were used to cytologically localise the wingless locus of Drosophila melanogaster. We found that an existing T(Y;2), which is an insertion of a segment of 2L into the Y chromosome, has wg + within this insert. This Y chromosome was used to generate an attached XY chromosome containing wg +. The mutation claret-nondisjunctional (ca nd) was used to induce the loss of this XY chromosome and thus generate gynandromorphs with wg 1/wg 1 male tissue and wg +/wg 1/wg 1 female tissue. Analysis of these gynanders demonstrated that a genotypically wingless mutant hemithorax is usually also phenotypically mutant in these half body mosaics; thus wg 1 is discautonomous. This observation is of interest as it is known that wg is not cell autonomous.  相似文献   

5.
The asymptotic quasi‐likelihood method is considered for the model yt = ft(θ) + Mt, t = 0,1, …,T where ftθ) is a linear predictable process of the parameter of interest θ, Mt is a martingale difference, and the nature of E(Mt2 | ℱt–1) is unknown. This paper is concerned with the limiting distribution of the asymptotic quasi‐score function of such a model. Confidence intervals and hypothesis testing of θ is derived from the limiting distribution. Comparison is made between the estimates obtained through this method and those obtained through the least squares method.  相似文献   

6.
7.
FLOWERING LOCUS M (FLM) is a MADS-domain gene that acts as an inhibitor of flowering in Arabidopsis. Here we describe the genetic interaction of FLM with genes in the photoperiod and autonomous flowering pathways. Although the sequence of FLM is most similar to that of FLC, FLM and FLC interact with different flowering pathways. It has been previously shown that flc lesions suppress the late-flowering phenotype of FRI-containing lines and autonomous-pathway mutants. However, flm lesions suppress the late-flowering phenotype of photoperiod-pathway mutants but not that of FRI-containing lines or autonomous-pathway mutants. Another MADS-domain flowering repressor with a mutant phenotype similar to FLM is SVP. The late-flowering phenotype of FLM over-expression is suppressed by the svp mutation, and an svp flm double mutant behaves like the single mutants. Thus FLM and SVP are in the same flowering pathway which interacts with the photoperiod pathway. Abbreviations: CO, CONSTANS; FLC, FLOWERING LOCUS C; FLM, FLOWERING LOCUS M; FRI, FRIGIDA; GI, GIGANTEA; LD, LUMINIDEPENDENS; SVP, SHORT VEGETATIVE PHASE; FCA is not an abbreviation  相似文献   

8.
Macrolycus is a genus of net‐winged beetles with 69 species distributed in the eastern Palearctic and northernmost part of the Oriental region. The first molecular phylogeny of Macrolycus was produced using an rrnL + tRNA‐Leu + nad1 mtDNA fragment. The major lineages and species limits were identified with morphology and molecular data. We propose that Cerceros is a subgenus of Macrolycus to enable identification of all adult specimens in the genus without DNA sequencing. Two species groups are proposed in Macrolycus s. str. and six in Cerceros. Additionally, twelve Macrolycus species are newly described from China: M. aquilinus, M. baihualingensis, M. bicolor, M. guangxiensis, M. jianfenglingensis, M. kuatunensis, M. lizipingensis, M. parvus, M. phoeniceus, M. rhodoneurus, M. rosaceus and M. sichuanensis. Macrolycus holzschuhi is proposed to be a junior subjective synonym of M. jeanvoinei. The highest diversity of Macrolycus is found in southern China. The species from the main islands of Japan are placed in two species groups: M. excellens is a sister to remaining species of the M. murzini group and the M. flabellatus group is a monophylum of closely related species in a sister position to the M. bicolor group.  相似文献   

9.
Hieracium pallidum subsp. aetnense Gottschl., Raimondo & Di Grist. is described and illustrated. H.pallidum is considered as an intermediate species between H. schmidtii and H. racemosum (“schmidtii>racemosum”) and is placed in H. sect. Grovesiana. By consequence, H.lanudae Gottschl. is transferred to H. pallidum as H. pallidum subsp. lanudae (Gottschl.) Gottschl., Raimondo & Di Grist. A key for the three recognised subspecies of H. pallidum is provided.  相似文献   

10.
11.
Approximate formulas for the mean and variance of the FSTor GST statistic in a finite number of isolated populations are developed under the effect of random genetic drift. Computer simulation has shown that the approximate formulas give a fairly accurate result unless the initial frequency of one of the alleles involved is close to 1 and t/2N is large, where N is the effective size of a subpopulation and t is the number of generations. It is shown that when the number of subpopulations (s) is small, the mean of FSTor GST depends on the initial gene frequencies as well as on s. When the initial frequencies of all alleles are nearly equal to each other and the number of subpopulations is large, the distribution of FST in the early generations is bell-shaped. In this case Lewontin and Krakauer's k parameter is approximately 2 or less. However, if one of the initial allele frequencies is close to 1, the distribution is skewed and leptokurtic, and the k parameter often becomes larger than 2 in later generations. Thus, even under pure random genetic drift, Lewontin and Krakauer's test of selective neutrality of polymorphic genes in terms of FST is not always valid. It is also shown that Jacquard's approximate formula for k generally gives an overestimate.  相似文献   

12.
The CAUCHY-PEXIDER functional equation H (x±y)=F(x) G(y) is generalized to the form H ((xc±yc)1/c) = F(x) G(y), c≠0, assuming the function H(x) possesses a measurable majorant on a set of positive measure. The result is used to obtain a characterization of WEIBULL distribution. This functional equation is generalized to functions of vector variables.  相似文献   

13.
Summary  Twenty-eight species of heterobasidiomycetes (phylum Basidiomycota) belonging to the orders Auriculariales, Dacrymycetales, Exidiales, Platygloeales, Sebacinales, Septobasidiales and Tremellales from Belize are described or reported. Endoperplexa phlebioides, Heterochaete pentadelphai and Sebacina pileata are described as new. The genus Aphelariopsis is considered a possible synonym of Septobasidium and the new combination Septobasidium kupemontis is proposed. The new combination Endoperplexa obscura is also proposed.  相似文献   

14.
Echidnopsis thulinii M. G. Gilbert is described from northern Somalia. The infrageneric classification of Echidnopsis Hook. f. is reviewed in the light of recently published molecular phylogenies. The new species belongs to E. sect. Echidnopsis and a key to the species of this section is provided. A lectotype, supported by an epitype, is designated for E. virchowii K. Schum. Echidnopsis sect. Profundicoronata Bruyns is included within sect. Vadosicoronata Bruyns and two new sections recognised: E. sect. Pseudopectinaria (Lavranos) M. G. Gilbert, based on the genus Pseudopectinaria Lavranos, and E. sect. Sobolifera M. G. Gilbert. A key is given to the sections of Echidnopsis.  相似文献   

15.
Abstract

A new species of Carabus (Lamprostus) from the province of Gilan, Iran, is described and illustrated: Carabus (Lamprostus) staveni sp. nov., Carabus (Pachystus) rechingerae Mandl, 1972, is considered a junior synonym of Carabus (Lamprostus) calleyi nigrinus Motschulsky, 1865. The specific status of Carabus (Sphodristocarabus) korgei Heinz, 1970, is restored (stat. rev.) and Carabus separatus delirensis Deuve, 2000, is considered to be a junior synonym of it. Carabus (Megodontus) stroganowi javahardensis Deuve, 2000, is considered to be a synonym of Carabus (Megodontus) heinrichi Mandl, 1966; both taxa are from the same type locality.  相似文献   

16.
《Journal of bryology》2013,35(3):178-183
Abstract

Fissidens firmus is revised, described, illustrated and a distribution is provided. It is compared to Fissidens hollianus, Fissidens pseudofirmus, Fissidens sedgwickii and Fissidens touwii. It is provisionally distinguished from F. firmus sensu auct. Fissidens multiflorus is reduced to F. hollianus. Lectotypes are designated for Fissidens multiflorus and Fissidens giesenhagenii. The collection that was reported from India as F. firmus appears to be F. hollianus. Thus, the present Western Ghats collection is effectively the first Indian record of F. firmus.  相似文献   

17.
The genus Crepicardus is endemic to Madagascar. Ten species are here recognized and redescribed; a key for their identification is given. The genus falls into three distinct species groups and one unassigned species: the klugii-group (klugii Castelnau, madagscariensis Fleutiaux, cribricollis Fleutiaux), the candezei-group (candezei Fairmaire stat.rev ., raffrayi Fairmaire, niger Candèze, puncticollis Fleutiaux), the trisulcatus-group (trisulcatus Candèze, mocquerysi Fleutiaux) and fleutiauxi Girard. Crepicardus costicollis (Castelnau) is again placed as a junior synonym of C.klugii (Castelnau) and candezei Fairmaire restored to specific status. Lectotypes are designated for klugii Castelnau, costicollis Castelnau, candezei Fairmaire, raffrayi Fairmaire, niger Candèze and mocquerysi Fleutiaux. On the basis of adult characters Crepicardus is here assigned to the Pyrophorinae sensu Stibick (1979) and its systematic position is discussed in relation to the widespread Pyrophorinae.  相似文献   

18.
The two generaPlectranthus andIsodon are compared and found to be very dissimilar.Isodon ist considered to be misplaced inOcimeae subtribePlectranthinae and apparently is more closely related to subtribeHyptidinae. The disjunct genusRabdosiella is compared to these two genera and regarded to be polyphyletic. The AfricanR. calycina (Benth.)Codd is returned toPlectranthus and calledP. calycinus Benth., while the AsianR. ternifolia (D. Don)Codd is placed inIsodon sect.Pyramidium and calledI. ternifolius (D. Don)Kudo.  相似文献   

19.
Canran Liu 《植被学杂志》2001,12(3):411-416
Abstract. The behaviour of five statistics (extensions of Pielou's, Clark and Evansapos;, Pollard's, Johnson & Zimmer's, and Eberhardt's statistics, which are denoted as Pi, Ce, Po, Jz and Eb respectively) that involve the distance from a random point to its jth nearest neighbour were examined against several alternative patterns (lattice‐based regular, inhomogeneous random, and Poisson cluster patterns) through Monte Carlo simulation to test their powers to detect patterns. The powers of all the five statistics increase as distance order j increases against inhomogeneous random pattern. They decrease for Pi and Ce and increase for Po, Jz, and Eb against regular and Poisson cluster patterns. Po, Jz, and Eb can reach high powers with the third or higher order distances in most cases. However, Po is recommended because no extra information is needed, it can reach a high power with the second or third distance even though the sample size is not large in most cases, and the test can be performed with an approximate χ2 distribution associated with it. When a regular pattern is expected, Jz is recommended because it is more sensitive to lattice‐based regular pattern than Po and Eb, especially for the first distance. However, simulation tests should be used because the speed of convergence of Jz to normal distribution is very slow.  相似文献   

20.
A nonlinear continuous-time Markov chain describing a two-step process of cytolytic cells binding to target and the subsequent lysis and release of label is shown to have kinetics which resemble standard enzyme-substrate kinetics. The Michaelis-Menten saturation function is found as a special case resulting when the target population is in excess. A comparison theorem for the pseudo-steady-state distribution Π is constructed to enable examination of that distribution whose expected value E and variance V satisfy - KmE + (CTE)(TTE) + V = 0, where Km is the Michaelis half-saturation constant and CT and TT are the initial populations of the two cell types. Using Π as an initial condition, the release of label process is examined. The main result is that the fraction of specific release, ƒ, has the approximate form when Tt is large, so that a nonlinear regression procedure is appropriate for the determination of the parameters.  相似文献   

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