472 research outputs found
\u3ci\u3eJhe in Gryllus assimilis\u3c/i\u3e: Cloning, sequence-activity associations and phylogeny
The 458 amino acid sequence of a mature JHE protein from the cricket Gryllus assimilis was identified after isolating the partial cDNA sequence encoding this protein from a fat body and midgut cDNA library. This hemimetabolan JHE sequence shows over 40% amino acid similarity to the known JHE sequences of several holometabolous insects. It also includes previously determined peptide sequences for G. assimilis JHE as well as two other motifs associated with JHE enzymes in holometabolous insects. The predicted molecular weight of the protein agrees with that of the JHE previously purified from G. assimilis. Partial genomic sequence encoding the Jhe contains two large (1330 and 2918 bp) introns. No coding DNA sequence variation was observed over a 1293 bp region between selected lines differing six to eight-fold in hemolymph JHE activity. However, a 19 bp indel was found in one of the introns; the insertion was strongly associated with elevated hemolymph activity, both in the selected lines and in the F2 progeny of crosses between them. Phylogenetic analyses localised the G. assimilis JHE to a clade containing dipteran and coleopteran JHEs, with lepidopteran JHEs occurring in a separate clade
\u3ci\u3eJhe in Gryllus assimilis\u3c/i\u3e: Cloning, sequence-activity associations and phylogeny
The 458 amino acid sequence of a mature JHE protein from the cricket Gryllus assimilis was identified after isolating the partial cDNA sequence encoding this protein from a fat body and midgut cDNA library. This hemimetabolan JHE sequence shows over 40% amino acid similarity to the known JHE sequences of several holometabolous insects. It also includes previously determined peptide sequences for G. assimilis JHE as well as two other motifs associated with JHE enzymes in holometabolous insects. The predicted molecular weight of the protein agrees with that of the JHE previously purified from G. assimilis. Partial genomic sequence encoding the Jhe contains two large (1330 and 2918 bp) introns. No coding DNA sequence variation was observed over a 1293 bp region between selected lines differing six to eight-fold in hemolymph JHE activity. However, a 19 bp indel was found in one of the introns; the insertion was strongly associated with elevated hemolymph activity, both in the selected lines and in the F2 progeny of crosses between them. Phylogenetic analyses localised the G. assimilis JHE to a clade containing dipteran and coleopteran JHEs, with lepidopteran JHEs occurring in a separate clade
Mesoscopic Transport Through Ballistic Cavities: A Random S-Matrix Theory Approach
We deduce the effects of quantum interference on the conductance of chaotic
cavities by using a statistical ansatz for the S matrix. Assuming that the
circular ensembles describe the S matrix of a chaotic cavity, we find that the
conductance fluctuation and weak-localization magnitudes are universal: they
are independent of the size and shape of the cavity if the number of incoming
modes, N, is large. The limit of small N is more relevant experimentally; here
we calculate the full distribution of the conductance and find striking
differences as N changes or a magnetic field is applied.Comment: 4 pages revtex 3.0 (2-column) plus 2 postscript figures (appended),
hub.pam.94.
Reassessing Britainâs âpost-war consensusâ: the politics of reason 1945â1979
Since the late-1970s, scholars have been engaged in a vibrant debate about the nature of post-war British politics. While some writers have suggested that the three decades that succeeded the Second World War witnessed a bi-partisan consensus on key policy questions, others have argued that it was conflict, not agreement, that marked the period. This article offers a novel contribution to this controversy by drawing attention to the epistemological beliefs of the Labour and Conservative parties. It argues that once these beliefs are considered, it becomes possible to reconcile some of the competing claims made by proponents and critics of the âpost-war consensusâ thesis. Labour and Conservative leaders may have been wedded to different beliefs, but they also shared a common enthusiasm for empiricist reasoning and were both reluctant to identify fixed political âendsâ that they sought to realise. Consequently, they were both committed to evolutionary forms of change, and they eschewed the notion that any social or political arrangement was of universal value
Weak-Localization in Chaotic Versus Non-Chaotic Cavities: A Striking Difference in the Line Shape
We report experimental evidence that chaotic and non-chaotic scattering
through ballistic cavities display distinct signatures in quantum transport. In
the case of non-chaotic cavities, we observe a linear decrease in the average
resistance with magnetic field which contrasts markedly with a Lorentzian
behavior for a chaotic cavity. This difference in line-shape of the
weak-localization peak is related to the differing distribution of areas
enclosed by electron trajectories. In addition, periodic oscillations are
observed which are probably associated with the Aharonov-Bohm effect through a
periodic orbit within the cavities.Comment: 4 pages revtex + 4 figures on request; amc.hub.94.
Effects of the field modulation on the Hofstadter's spectrum
We study the effect of spatially modulated magnetic fields on the energy
spectrum of a two-dimensional (2D) Bloch electron. Taking into account four
kinds of modulated fields and using the method of direct diagonalization of the
Hamiltonian matrix, we calculate energy spectra with varying system parameters
(i.e., the kind of the modulation, the relative strength of the modulated field
to the uniform background field, and the period of the modulation) to elucidate
that the energy band structure sensitively depends on such parameters:
Inclusion of spatially modulated fields into a uniform field leads occurrence
of gap opening, gap closing, band crossing, and band broadening, resulting
distinctive energy band structure from the Hofstadter's spectrum. We also
discuss the effect of the field modulation on the symmetries appeared in the
Hofstadter's spectrum in detail.Comment: 7 pages (in two-column), 10 figures (including 2 tables
The genetic contribution of single male immigrants to small, inbred populations: A laboratory study using drosophila melanogaster
This study examined the genetic contribution of single male immigrants to small, inbred laboratory populations of Drosophila melanogaster. Genetic contribution was assessed by measuring the relative frequency of immigrant marker alleles in the first and second generations after immigration, while controlling for any selection effects at the marker locus, and for the experience of male immigrants. When immigrants were outbred, the mean frequency of the immigrant allele was significantly higher than its initial frequency, in both the first and second generations after immigration. There was no significant change in allele frequency for populations receiving inbred immigrants. The increase in allele frequency for outbred immigrants was attributed to an initial outbred vigour fitness advantage of immigrant males over resident males experiencing inbreeding depression. Hybrid vigour of immigrant progeny and the rare-male effect did not have a statistically significant role in the fitness advantage of the immigrant allele. The results suggest that inbreeding may have a considerable impact on the contribution of immigrants to the genetic diversity of populations
Editors' introduction: the book, the conference, and fighting back
This book makes a strong case for the abiding relevance of Dewey's notion of learning through experience, with a community of others, and what this implies for democratic 21st century education
Communitarian perspectives on social enterprise
Concepts of social enterprise have been debated repeatedly, and continue to cause confusion. In this paper, a meta-theoretical framework is developed through discussion of individualist and communitarian philosophy. Philosophers from both traditions build social theories that emphasise either consensus (a unitarist outlook) or diversity (a pluralist outlook). The various discourses in corporate governance reflect these assumptions and create four distinct approaches that impact on the relationship between capital and labour. In rejecting the traditional discourse of private enterprise, social enterprises have adopted other approaches to tackle social exclusion, each derived from different underlying beliefs about the purpose of enterprise and the nature of governance. The theoretical framework offers a way to understand the diversity found within the sector, including the newly constituted Community Interest Company (CIC).</p
The Big Society and the Conjunction of Crises: Justifying Welfare Reform and Undermining Social Housing
The idea of the âBig Societyâ can be seen as culmination of a long-standing debate about the regulation of welfare. Situating the concept within governance theory, the article considers how the UK coalition government has justified a radical restructuring of welfare provision, and considers its implications for housing provision. Although drawing on earlier modernization processes, the article contends that the genesis for welfare reform was based on an analysis that the government was forced to respond to a unique conjunction of crises: in morality, the state, ideology and economics. The government has therefore embarked upon a programme, which has served to undermine the legitimacy of the social housing sector (most notably in England), with detrimental consequences for residents and raising significant dilemmas for those working in the housing sector
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