On the relationship between small and large signal modulation capabilities in highly nonlinear quantum dot lasers

The 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

Development of high-speed directly-modulated DFB and DBR lasers with surface gratings

The 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

Empty spaces and the value of symbols: Estonia's 'war of monuments' from another angle

Taking 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

A future without forgiveness: beyond reconciliation in transitional justice

This article questions the promotion of reconciliation in transitional justice contexts. The article puts forward a critique of reconciliation in practice and questions mainstream definitions of reconciliation. The principle that these forms of reconciliation are desirable is also questioned. It is argued that examples of genuine reconciliation are difficult to find, that the promotion of reconciliation is frequently emphasised at the expense of substantive societal change, that emphasis on reconciliation (narrowly defined) risks taking agency away from those affected by conflict and that emphasis on reconciliation may obscure injustice and may promote acceptance of the status quo. The article suggests that reconciliation is not a necessary condition of, and should be de-emphasised in, transitional justice and, if it is promoted at all, that a different, less prescriptive notion of reconciliation is necessary

Exploring synergies between human rights and public health ethics: A whole greater than the sum of its parts

<p>Abstract</p> <p>Background</p> <p>The fields of human rights and public health ethics are each concerned with promoting health and elucidating norms for action. To date, however, little has been written about the contribution that these two justificatory frameworks can make together. This article explores how a combined approach may make a more comprehensive contribution to resolving normative health issues and to advancing a normative framework for global health action than either approach made alone. We explore this synergy by first providing overviews of public health ethics and of international human rights law relevant to health and, second, by articulating complementarities between human rights and public health ethics.</p> <p>Discussion</p> <p>We argue that public health ethics can contribute to human rights by: (a) reinforcing the normative claims of international human rights law, (b) strengthening advocacy for human rights, and (c) bridging the divide between public health practitioners and human rights advocates in certain contemporary health domains. We then discuss how human rights can contribute to public health ethics by contributing to discourses on the determinants of health through: (a) definitions of the right to health and the notion of the indivisibility of rights, (b) emphasis on the duties of states to progressively realize the health of citizens, and (c) recognition of the protection of human rights as itself a determinant of health. We also discuss the role that human rights can play for the emergent field of public health ethics by refocusing attention on the health and illness on marginalized individuals and populations.</p> <p>Summary</p> <p>Actors within the fields of public health, ethics and human rights can gain analytic tools by embracing the untapped potential for collaboration inherent in such a combined approach.</p

Adapting legume crops to climate change using genomic approaches

Our agricultural system and hence food security is threatened by combination of events, such as increasing population, the impacts of climate change, and the need to a more sustainable development. Evolutionary adaptation may help some species to overcome environmental changes through new selection pressures driven by climate change. However, success of evolutionary adaptation is dependent on various factors, one of which is the extent of genetic variation available within species. Genomic approaches provide an exceptional opportunity to identify genetic variation that can be employed in crop improvement programs. In this review, we illustrate some of the routinely used genomics‐based methods as well as recent breakthroughs, which facilitate assessment of genetic variation and discovery of adaptive genes in legumes. Although additional information is needed, the current utility of selection tools indicate a robust ability to utilize existing variation among legumes to address the challenges of climate uncertainty

Understanding conflict-related sexual violence and the ‘everyday’ experience of conflict through witness testimonies.

The testimonies of witnesses who testify before criminal courts provide crucial insights into the situated experience of conflict-related sexual violence. Witness testimonies highlight the complex realities and everyday lives of individuals caught up in situations of armed conflict. The evidence presented by witnesses can provide vital insights into lived experiences of wartime violence, and reveal the seemingly mundane strategies and tactics adopted by victims to cope with, survive and resist the violent and coercive circumstances of war. This article foregrounds conflict-related sexual violence witness testimonies as highly significant sources of knowledge of the everyday experiences of conflict. It sets out a bottom-up, mixed-method approach for identifying and analysing the experiential accounts of those who lived through conflict-related sexual violence, while engaging with the opportunities and challenges of using witness testimony. Our approach unsettles existing notions of ‘the everyday’ in Peace & Conflict Studies as a synonym for narratives and practices of violence, justice and peacebuilding that are private, informal and largely hidden from view. Understanding witness testimonies requires conceptualising the everyday as an amalgam of formal and informal practices, as accessible through both elite and lay knowledges and as documented in both public and private (e.g. redacted) sources. It requires challenging taken-for-granted dichotomies that are frequently invoked to understand conflict and peace