102 research outputs found
On the relationship between small and large signal modulation capabilities in highly nonlinear quantum dot lasers
No full textThe small signal modulation response of semiconductor lasers is commonly used to predict large signal modulation capabilities. Recent experiments suggest that this prediction may fail in some quantum dot (QD) lasers. We present a model supported by experiments, which shows that when the small signal modulation response is limited by gain compression and the gain is large, the laser can be modulated at very high bit rates. This effect is inherent to dynamics governing all semiconductor lasers but the conditions needed for high bit rate modulation in the presence of narrow small signal bandwidths are only obtainable in QD lasers
Empty spaces and the value of symbols: Estonia's 'war of monuments' from another angle
No full textTaking as its point of departure the recent heightened discussion surrounding publicly sited monuments in Estonia, this article investigates the issue from the perspective of the country's eastern border city of Narva, focusing especially upon the restoration in 2000 of a 'Swedish Lion' monument to mark the 300th anniversary of Sweden's victory over Russia at the first Battle of Narva. This commemoration is characterised here as a successful local negotiation of a potentially divisive past, as are subsequent commemorations of the Russian conquest of Narva in 1704. A recent proposal to erect a statue of Peter the Great in the city, however, briefly threatened to open a new front in Estonia's ongoing 'war of monuments'. Through a discussion of these episodes, the article seeks to link the Narva case to broader conceptual issues of identity politics, nationalism and post-communist transition
Legal Empowerment: Between Transition and Transformation
No full textChapter 5 argues for a ‘good enough’ transitional justice which seeks to do more whilst acknowledging both its core strengths and limitations. The chapter explores the potential of linking transitional justice to development and the rule of law through the vehicle of legal empowerment. Building on relationships between transitional justice and development, collective reparations, the rule of law, and access to justice, Waldorf argues that there are four strong reasons to link transitional justice and legal empowerment. 1) They share key goals, notably accountability and building civic trust. 2) There is an increasing convergence in methods, as transitional justice becomes more participatory and bottom-up in orientation. 3) Both approaches contribute to a ‘socialization of a rights culture.’ 4) Transitional justice can help create openings for legal mobilization, claims-making and empowerment. Ultimately, the author argues for legal empowerment as a form of collective legal rehabilitation or reparations
1.3 µm two-section DBR lasers based on surface defined gratings for high speed telecommunication
No full textInP-based two-section distributed Bragg reflector lasers employing surface defined lateral gratings, which are compatible with low-cost nanoimprint technology, were fabricated. A newly developed inductively coupled plasma reactive ion etching process was utilized for obtaining large aspect ratios and good device performance. The lasers operate in a single mode up to 50 degrees C under continuous-wave conditions. A modulation bandwidth of about 10 GHz was obtained for 0.9-mm-long device
Conformational preferences of the substrates of lactate dehydrogenase.
No full textThe substrates of lactate dehydrogenase (pyruvate and lactate) as well as an inhibitor (oxamate) are characterized using ab initio methods employing the basis sets 6-31 +G(d) and 6-31 +G(d, p) at both RHF and MP2 levels. The first aim of these studies i
Development of high-speed directly-modulated DFB and DBR lasers with surface gratings
No full textThe conventional distributed feedback and distributed Bragg reflector edge-emitting lasers employ buried gratings, which require two or more epitaxial growth steps. By using lateral corrugations of the ridge-waveguide as surface gratings the epitaxial overgrowth is avoided, reducing the fabrication complexity, increasing the yield and reducing the fabrication cost. The surface gratings are applicable to different materials, including Al-containing ones and can be easily integrated in complex device structures and photonic circuits. Single-contact and multiple contact edge-emitting lasers with laterally-corrugated ridge waveguide gratings have been developed both on GaAs and InP substrates with the aim to exploit the photon-photon resonance in order to extend their direct modulation bandwidth. The paper reports on the characteristics of such surface-grating-based lasers emitting both at 1.3 and 1.55 μm and presents the photon-photon resonance extended small-signal modulation bandwidth (> 20 GHz) achieved with a 1.6 mm long single-contact device under direct modulation. Similarly structured devices, with shorter cavity lengths are expected to exceed 40 GHz smallsignal modulation bandwidth under direct modulatio
C-type lectin-like domains in <it>Fugu rubripes</it>
No full textAbstract Background Members of the C-type lectin domain (CTLD) superfamily are metazoan proteins functionally important in glycoprotein metabolism, mechanisms of multicellular integration and immunity. Three genome-level studies on human, C. elegans and D. melanogaster reported previously demonstrated almost complete divergence among invertebrate and mammalian families of CTLD-containing proteins (CTLDcps). Results We have performed an analysis of CTLD family composition in Fugu rubripes using the draft genome sequence. The results show that all but two groups of CTLDcps identified in mammals are also found in fish, and that most of the groups have the same members as in mammals. We failed to detect representatives for CTLD groups V (NK cell receptors) and VII (lithostathine), while the DC-SIGN subgroup of group II is overrepresented in Fugu. Several new CTLD-containing genes, highly conserved between Fugu and human, were discovered using the Fugu genome sequence as a reference, including a CSPG family member and an SCP-domain-containing soluble protein. A distinct group of soluble dual-CTLD proteins has been identified, which may be the first reported CTLDcp group shared by invertebrates and vertebrates. We show that CTLDcp-encoding genes are selectively duplicated in Fugu, in a manner that suggests an ancient large-scale duplication event. We have verified 32 gene structures and predicted 63 new ones, and make our annotations available through a distributed annotation system (DAS) server http://anz.anu.edu.au:8080/Fugu_rubripes/ and their sequences as additional files with this paper. Conclusions The vertebrate CTLDcp family was essentially formed early in vertebrate evolution and is completely different from the invertebrate families. Comparison of fish and mammalian genomes revealed three groups of CTLDcps and several new members of the known groups, which are highly conserved between fish and mammals, but were not identified in the study using only mammalian genomes. Despite limitations of the draft sequence, the Fugu rubripes genome is a powerful instrument for gene discovery and vertebrate evolutionary analysis. The composition of the CTLDcp superfamily in fish and mammals suggests that large-scale duplication events played an important role in the evolution of vertebrates.</p
On Fernando's Photograph: The Biopolitics of Aparicion in Contemporary Argentina
No full textThis article concerns the striking photograph of a young man, Fernando Brodsky, taken shortly after he was kidnapped in Argentina in 1979. Brodsky was detained in the notorious Escuela de la Armada (ESMA) in Buenos Aires, and remains disappeared. The negative of the photograph was smuggled out of ESMA and the image became part of a bundle of photographic evidence submitted by families of the disappeared during the trials of the military after the return to democracy in 1983. This article seeks to under- stand the vitality of the photograph, the different courses it takes, the archives it joins and leaves, asking: ‘What sort of life can the photograph have? What sort of desire? What sort of politics?’ The article proposes that we might consider the role of such images ‘biopolitically’, which is to say in the context of the relations established through the attempts to govern populations in times of military rule and in times of transitional democracy. The re-appearance of Fernando in the photograph is part of post-dictator- ship politics in which the demand ‘aparición’ resounds. Fernando, an absolute witness who does not, who cannot, speak nevertheless re-appears in the law courts and in art exhibitions. The article considers the difference between the photograph’s appearance as evidence and its reappearance in the art galleries, arguing that its ‘desires’ can be imagined differently in each. The article argues that while the photograph does not escape archives tout court, in raising the question of how it should be filed, it prompts reflec- tion on the biopolitical present, with its inequitable distribution of life and security among populations. This is a politics of the present, more than it is a politics of memory
ChemInform Abstract: Preparation of 8-Substituted Pyrido(2,3-d)pyrimidines (N5-Deazapterins) .
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