The Concept of State Identity in International Relations : A Theoretical Analysis 【Article】

The identity problematique is fast moving to the core of the research agenda of international relations discipline, and the concept of state identity has now become a permanent feature of the constructivist discourse. This paper identifies four problems attendant upon the introduction of the state identity con-cept to international relations theory. Firstly, the relationship between state identity and other importantconcepts of constructivist argument is underspecified. Secondly, the question of how states chooseamong multiple identities is not sufficiently addressed by constructivists. Thirdly, the concept of stateidentity has been rather slow to find its way into empirical research and is still largely ignored by therationalist scholars. Finally, the link between state identities and power tends to be neglected by bothconstructivist scholars and their rationalist rivals. In addressing these problems, the paper clarifies therelationship between state identity, culture and norms and provides a systematic review of the state iden-tity approaches. The paper proposes a new definition of the concept that is compatible with the rational-ist foundations of the mainstream of international relations discipline. It illuminates the role of stateidentity as a tool in the strategic interaction among states, and provides several examples to illustrate theclose relationship between state identities and power. Since power is the key explanatory concept formany rationalist approaches, the paper argues that the concept of state identity also deserves to be animportant part of rationalist analytical frameworks

A continuous-flow ATP amplification system for increasing the sensitivity of quantitative bioluminescence assay

We constructed a novel ATP amplification reactor using a continuous-flow system, and this allowed us to increase the sensitivity of quantitative bioluminescence assay by controlling the number of ATP amplification cycles. We previously developed a bioluminescence assay coupled with ATP amplification using a batch system. However, it was difficult to control the number of amplification cycles. In this study, ATP amplification was performed using a continuous-flow system, and significant linear correlations between amplified luminescence and initial ATP concentration were observed. When performing 4 cycles of continuous-flow ATP amplification, the gradient of amplification was 1.87N. Whereas lower quantifiable level was 500 pM without amplification, values as low as 50 pM ATP could be measured after amplification. Sensitivity thus increased 10-fold, with further improvements expected with additional amplification cycles. The continuous-flow system thus effectively increased the sensitivity of quantitative bioluminescence assay

Molecular Engineering of a Fluorescent Bioprobe for Sensitive and Selective Detection of Amphibole Asbestos

<div><p>Fluorescence microscopy-based affinity assay could enable highly sensitive and selective detection of airborne asbestos, an inorganic environmental pollutant that can cause mesothelioma and lung cancer. We have selected an <i>Escherichia coli</i> histone-like nucleoid structuring protein, H-NS, as a promising candidate for an amphibole asbestos bioprobe. H-NS has high affinity to amphibole asbestos, but also binds to an increasingly common asbestos substitute, wollastonite. To develop a highly specific Bioprobe for amphibole asbestos, we first identified a specific but low-affinity amosite-binding sequence by slicing H-NS into several fragments. Second, we constructed a streptavidin tetramer complex displaying four amosite-binding fragments, resulting in the 250-fold increase in the probe affinity as compared to the single fragment. The tetramer probe had sufficient affinity and specificity for detecting all the five types of asbestos in the amphibole group, and could be used to distinguish them from wollastonite. In order to clarify the binding mechanism and identify the amino acid residues contributing to the probe’s affinity to amosite fibers, we constructed a number of shorter and substituted peptides. We found that the probable binding mechanism is electrostatic interaction, with positively charged side chains of lysine residues being primarily responsible for the probe’s affinity to asbestos.</p> </div

Adsorption of the engineered peptide tetramers on amosite.

<p>Pep1-Pep7 were used to identify the binding sequence and optimal linker length. Pep8-Pep14 were used to determine the binding mechanism and the contribution of individual amino acids of the binding sequence. The percentage values indicate the adsorption of each peptide tetramer relative to that of pep3, which is referred to as the “original binding sequence”.</p

SDS–PAGE analysis of amosite-binding proteins isolated from <i>E. coli</i> lysate.

<p>SDS–PAGE analysis of amosite-binding proteins isolated from <i>E. coli</i> lysate.</p

Specificity of fluorescently labeled tetramers of H-NS fragments.

<p>The fibers are stained with fluorescently labeled tetramers of the indicated H-NS fragments. Each pair of phase contrast and fluorescence micrographs of amosite and wollastonite fibers shows the same field of view. Bar, 50 µm.</p

Scatchard analysis of H-NS_60-90 monomer and its streptavidin-based tetramer’s adsorption on amosite.

<p>Scatchard analysis of H-NS_60-90 monomer and its streptavidin-based tetramer’s adsorption on amosite.</p

Amosite fibers stained with fluorescently labeled monomers and streptavidin-based tetramers of H-NS_60-90.

<p>Each pair of phase contrast and fluorescence micrographs shows the same field of view. Due to lower affinity of H-NS_60-90 monomer, its adsorption on amosite at the indicated concentration is minimal. Bar, 10 µm.</p