Component Of Element Research Articles

Nucleotide sequence and characterization of a gene encoding the phytochrome polypeptide from Avena

We have isolated and characterized a gene encoding the phytochrome polypeptide of Avena. Based on nucleotide sequence identity with previously sequenced cDNA clones this gene is designated as type 3 ( phy3). The gene is about 5.9 kb long with six exons and five introns, one each of the latter in the 5 ' and 3 ' -untranslated regions. The largest exon encodes the entire 74-kDa, chromophore-bearing, N-terminal domain of the photoreceptor postulated to be directly involved in its mechanism of action. The transcription start point, identified by mung-bean nuclease digestion, is located 24 to 35 bp downstream from a tandem TATA box. Sequence elements homologous to a number of motifs implicated as upstream regulatory elements in other genes are present in the 5'-flanking DNA of phy3. Particularly intriguing are three elements at positions -140, -470 and -650. These elements share homology with the ‘GT’ motif postulated to be a component of the light-regulatory element of genes encoding the small subunit of ribulose bisphosphate carboxylase.

A triangular membrane element with rotational degrees of freedom

A new plane-stress triangular element is derived using the free formulation of Bergan and Nygård. The triangle possesses nine degrees of freedom: six corner translations and three corner normal rotations. The element is coordinate-invariant and passes the patch test for any geometry. Two free parameters in the formulation may be adjusted to optimize the behavior for in-plane bending patterns. With the recommended parameter choices the element performance is significantly better than that of the constant-strain triangle. Because of the presence of the rotational freedoms, this new element appears especially suitable as membrane component of a flat triangular element for modelling general shell structures.

Beta decay rate of the [formula omitted] transition for the study of meson-exchange effects and gp/ gA

The O − → O + β-decay rate has been measured by means of a new experimental method. A decay rate W β = 0.60 ± 0.07 s −1 has been obtained which is 50% larger than previously measured values. From this value combined with the μ − capture rate, a large meson-exchange effect in the time component of the transition matrix element, and a gp/ tg A value larger than 12 are required for consistency.

On the group of automorphisms of affine algebraic groups

We study the conservativeness property of affine algebraic groups over an algebraically closed field of characteristic O and of their group of automorphisms. We obtain a certain decomposition of affine algebraic groups, and this, together with the result of Hochschild and Mostow, becomes a major tool in our study of the conservativeness property of the group of automorphisms. 1. Introduction. Let G be an affine algebraic group over a field F, with Hopf algebra 6g(G) of polynomial functions on G, in the sense of (2) and let W(G) denote the group of all affine algebraic group automorphisms of G. Then 6D(G) may be viewed as a right W(G)-module, with W(G) acting by compositionff o ol on 6D(G). We recall, from (3), that G is said to be conservative if (G) is locally finite as a W(G)-module. As is shown in (3), the conservativeness of G character- izes the existence of a suitable affine algebraic group structure on W(G) and the obstruction to the conservativeness of a connected G is realized as the presence of certain central tori in G, when the base field F is algebraically closed and of characteristic 0. In the present study of W(G), we exploit the above results and technique of (3) and, accordingly, we refer to (2) and (3) for standard facts concerning affine algebraic groups and their automorphism group. The following are brief descriptions of the contents appearing in each section: In §2, we examine reductive affine algebraic groups and their conservativeness and, in §3, we establish a certain W(G)-invariant decompo- sition of G when G is conservative. Finally, in §4, we use the result obtained in §3 to study the structure of W(G). The following notation is standard throughout: Let G be an affine algebraic group. Then Gl denotes the connected component of the identity element of G and Z(G) the center of G. If x E G, we use lx to denote the inner automorphism of G that is induced by x, and, for a subset S of G,

Chromosomal map locations of integrated plasmids and related elements in Staphylococcus aureus

The chromosomal integration sites of several derivatives of the pI258 penicillinase plasmid (one, Ω42[pI258 incl −], being deficient in incompatibility specificity, another, Ω50[pI258 repA18], being deficient in replication, and several others, Ω1[pI258 ermB], etc., involving only the erythromycin-resistance locus) were investigated by transformation. The Ω42 and Ω50 sequences were located, perhaps at the same site, between tmn (chromosomal tetracycline-minocycline resistance) and pur-110 in the tmn- pur- ilv- pig (pigmentation) linkage group. Evidence is presented for the presence of the entire pI258 plasmid as an integrated gene sequence in both integrated plasmid-bearing strains. Closely linked to this region of Ω42 and Ω50 integration is attφ11, the integration site for the φ11 prophage. Transformations have also established at least two different sites of integration of the pI258 ermB locus, and it is concluded that this gene is a component of a translocatable element. In addition, the chromosomal location of the Ps53 bla locus has been established. By analogy with certain other strains carrying chromosomal β-lactamase determinants, it is probable that this gene can also translocate. The linkage group carrying these insertions is now defined as … Ω5-tmn-3106-attφ11-( Ω42, Ω50)- Ω1-pur-110-Ps53bla-ilv-129-pig-131 …

Dielectric Constant and Magneto-Optical Kerr Rotation of Ferromagnetic Chromium Tribromide above the Absorption Band Edge

By extending the optical and magneto-optical measurements of the insulating ferromagnet CrBr3 (hexagonal layer structure, Tc=36°K, and 4πMs=3520 G) beyond the absorption band edge near 22 000 cm−1 with reflection techniques, three absorption bands representing the π and σ processes of electron transfer transitions and an internal transition of Cr3+ have been observed. The room-temperature dielectric constant was measured by means of an ellipsometer. The σ process and the internal transitions give rise to the two absorption bands at 24 310 cm−1 and 29 580 cm−1 with oscillator strengths of 0.30 and 1.61, respectively. They account for most of the dielectric constant. While the π process is too weak to be resolved in the dielectric constant data, it accounts for the main peak of the normal incidence polar Kerr rotation at 1.5°K of 3.5° at 23 500 cm−1. The σ process accounts for the relatively sharp negative peak in the Kerr rotation of −2.5° at 26 700 cm−1. The data further suggest that the π process component of the off-diagonal element of the electric polarizability tensor has opposite sign to the σ process and the internal transitions.

An application of the generalized norm residue symbol

Let k be an algebraic number field of finite degree or an algebraic function field of dimension 1 with finite constant field and let K/k be a finite, separably Galois extension field. We call an algebraic extension field L, not necessarily Galois nor necessarily of finite degree, of K an everywhere locally abelian extension, denoted in the following as EL-abelian extension, for brevity, of K over k, if and only if for every finite extension L' of K in L and every valuation v of L it holds that the completion field Lv' of L' with reference to v is a composition field of KV and an abelian extension Mv of kv in Lv', where we denote by kv and KV the closures of k and K in Lv', respectively. Let Q be an algebraic closure of K, BK/k the maximum separably EL-abelian extension of K/k in Q, CK/k the maximum separably central extension of K/k in Q (i.e. the maximum extension CK/k which is separably normal over k, contains K, and has the Galois group of CK/k/K in the center of the Galois group of CK/k/k), Ik and IK the groups of the ideles of k and K, Ak and AK the maximum separably abelian extensions of k and K in Q, respectively. Let DK/k=BK/k nCKIk. Then, the norm residue symbol 0Jk in Ak/k is, if restricted into NK/kIK, extensible into a homomorphism UK/k of NK/kIK into the Galois group G(DK/k/K). We shall study in the present article arithmetical meanings of the extensibility. In ?1, we shall define oUK/k precisely, in ?2, study the kernel and obtain a principal genus theorem (Theorem 2), from which will follow easily a certain generalized formulation of some fundamental theorems in the class field theory.1 Combining it with a known property2 of the quotient group of the connected component of the unit element of the idele class group by the natural image of the maximal compact subgroup of the connected component of the unit element of the idele group, we shall obtain, in ?3, our main result (Theorem 8), which concerns total norm residues in the principal idele group of k for K/k, and which is, the author thinks, an idele-theoretic reconstruction of a research of Scholz.3

On a Conjecture of Montgomery

Throughout the paper, G denotes a compact Lie group and GC the connected component of the identity element in G. If G is a finite group, ord (G) denotes the number of elements in G. If g e G, ord (g) denotes the usual order of g. LEMMA 1. Let G be a compact Lie group and B an integer. Then there are at most a finite number of (mutually) non-conjugate subgroups H with ord (H) < B. PROOF. Obviously it suffices to prove that there exist at most a finite number of non-conjugate subgroups H with ord (H) = B. Proof is by contradiction. Suppose H1 , H2, * * is an infinite sequence of mutually non-conjugate subgroups

The Automorphism Group of a Lie Group

Introduction. The group A (G) of all continuous and open automorphisms of a locally compact topological group G may be regarded as a topological group, the topology being defined in the usual fashion from the compact and the open subsets of G (see ?1). In general, this topological structure of A (G) is somewhat pathological. For instance, if G is the discretely topologized additive group of an infinite-dimensional vector space over an arbitrary field, then A (G) already fails to be locally compact. On the other hand, if G is a connected Lie group, we shall show without any difficulty that the compact-open topology of A (G) coincides with the topology obtained by identifying A (G) with a closed subgroup of the linear group of automorphisms of the Lie algebra of G, as was done by Chevalley (in [1]) in order to make A (G) into a Lie group. We shall then deduce that A (G) is a Lie group whenever the group of its components, G/Go, is finitely generated('), where Go denotes the component of the identity element in G. The other questions with which we shall be concerned are the following: Let I(Go) denote the group of the inner automorphisms of Go, and let E(Go, G) denote the natural image in A (Go) of A (G). Regard I(Go) and E(Go, G) as