Optical turbulence and spectral condensate in long-fiber lasers

We study optical wave turbulence using as a particular example recently created ultralong-fiber laser. We show that the sign of the cavity dispersion has a critical impact on the spectral and temporal properties of generated radiation that are directly relevant to the fiber laser performance. For a normal dispersion, we observe an intermediate state with an extremely narrow spectrum condensate, which experiences an instability and a sharp transition to a strongly fluctuating regime with a wide spectrum and increased probability of spontaneous generation of large-amplitude pulses.

Ireland and immigration: explaining the absence of the far right

Garner seeks to explain the absence of far-right political formations in the history of the Republic of Ireland, especially in relation to immigration. He argues that the ‘mainstream’ nationalist parties have implemented a racialized governance of Ireland via the issue of citizenship (in the referendum of 2004). While hegemonic ideas on the racial purity of indigenous populations and the highly ambivalent attitudes and policies on immigration pursued over the last decade are characteristic of a broader European trend, this has not, in the Republic, been accompanied by meaningful far-right political mobilization. Ireland has frequently been seen as sui generis in political terms, and indeed emerges in some ways as a counter-case: increasing hostility towards Others has been identified in the midst of rapid economic growth and political stability. A variety of issues related to the country’s political development have given rise to an especially small left-wing vote, a nationalist centre ground and longlasting domination by a single populist party, Fianna Fa´ il. This party has been partnered in government since 1997 by a free-market party, the Progressive Democrats, who have contributed to Ireland’s movement towards neo-liberal policies and a highly functional approach to immigration. The transition from country of emigration to country of immigration has thus taken place against an ideological backdrop in which the imperatives of labour demand and consolidating domestic support for reform have made an uneasy match, resulting in the racialization of Irishness. The state has, however, amended the Constitution in order to qualify jus soli citizenship entitlement in the case of particular categories of people: those whose parents are not Irish nationals. The significant stakes of these changes are analysed in the context of state responses to Eire’s transition to a country of immigration, and the role of nationalist-populism in the country’s political culture.

Political parties and public policy in the German Länder:when parties matter

When Parties Matter looks at the extent to which political parties can make a difference to public policy, focusing on the regional level in Germany. Politicians of the left and the right sometimes have radically different views, but inevitably the combined forces of legal and financial constraints, bureaucracy, public expectations and the 'weight of history' restrict their ability to translate political disagreement into policy change. Giving a detailed examination of education policy, childcare and family policy, and labour market policy in three German regions between 1999 and 2006, this book provides insights into what politicians can and cannot achieve, in particular at the level below the nation-state.

Advocating alcohol abstinence to pregnant women: some observations about British policy

In 2007, the English Department of Health (DH) issued advice stating 'pregnant woman' and 'those trying to conceive' should abstain from drinking alcohol. As others have noted, this advice was issued despite their being no new evidence about the deleterious effects of low levels of alcohol consumption. In this paper, we argue this development is significant for the social construction of 'risk', since in advocating abstinence without an evidence base for this advice, policy makers formalise a connection between uncertainty and danger. We suggest this development has important implications, most obviously for pregnant women, certainly impacting on the nature of the advice they will now receive and likely more generally on their experience of the transition to motherhood. We suggest it has wider implications for individuals' experience also, as policy makers appear to be advocating the same approach to risk to non-pregnant people. Further, it suggests a noteworthy formalisation of a new definition of risk, which should be debated far more extensively, as it matters for the future development of health policy.

Peer mentoring in higher education:a multidimensional approach to conceptualising the role of peer mentoring programmes in enhancing the first year undergraduate experience

Across the literature researchers agree that the concept of mentoring results in positive outcomes for both mentors and mentees alike (Enrich et al, 2004). From a pedagogical perspective, student focused mentoring activities in Higher Education are generally perceived to comprise dyadic or triadic relationships that encapsulate a diverse range of learning strategies and/or support mechanisms. Whilst there exists a significant amount of literature regarding the wider value of Peer Mentoring in Higher Education, there remains a notable gap in knowledge about the value of such programmes in enhancing the first year undergraduate experience and thus promoting a smooth transition to University. Using the emergent study findings of a large international project, a multidimensional conceptual framework bringing together the theoretical, conceptual and contextual determinants of Peer Mentoring is proposed. This framework makes a distinctive contribution to current pedagogical theory and practice – particularly in relation to the first year experience.

Transition of planar Couette flow at infinite Reynolds numbers

An outline of the state space of planar Couette flow at high Reynolds numbers (Re<105) is investigated via a variety of efficient numerical techniques. It is verified from nonlinear analysis that the lower branch of the hairpin vortex state (HVS) asymptotically approaches the primary (laminar) state with increasing Re. It is also predicted that the lower branch of the HVS at high Re belongs to the stability boundary that initiates a transition to turbulence, and that one of the unstable manifolds of the lower branch of HVS lies on the boundary. These facts suggest HVS may provide a criterion to estimate a minimum perturbation arising transition to turbulent states at the infinite Re limit. © 2013 American Physical Society.

Germany and the European union:from 'tamed power' to normalized power?

Germany has traditionally played a key role in promoting European Union solutions to domestic policy problems. In doing so it gained a reputation as a 'tamed power' (Katzenstein). This article reviews Germany's diplomacy two decades after unification. It explores the 'tamed power' hypothesis with reference to three policy areas: constitutional reform in the EU; Justice and Home Affairs policy; and an issue that has made German European policy very salient of late, the management of the Eurozone. The article argues that Germany has become a much less inclusive actor in European policy, pursuing policy solutions through 'pioneer groups' where these offer greater promise than the EU itself and becoming increasingly attentive to domestic political constraints. The article argues that Germany has become a normalized power, with significant implications for the EU. © 2010 The Author(s). International Affairs © 2010 The Royal Institute of International Affairs.

Nanophotonics of optical fibers

This review is concerned with nanoscale effects in highly transparent dielectric photonic structures fabricated from optical fibers. In contrast to those in plasmonics, these structures do not contain metal particles, wires, or films with nanoscale dimensions. Nevertheless, a nanoscale perturbation of the fiber radius can significantly alter their performance. This paper consists of three parts. The first part considers propagation of light in thin optical fibers (microfibers) having the radius of the order of 100 nanometers to 1 micron. The fundamental mode propagating along a microfiber has an evanescent field which may be strongly expanded into the external area. Then, the cross-sectional dimensions of the mode and transmission losses are very sensitive to small variations of the microfiber radius. Under certain conditions, a change of just a few nanometers in the microfiber radius can significantly affect its transmission characteristics and, in particular, lead to the transition from the waveguiding to non-waveguiding regime. The second part of the review considers slow propagation of whispering gallery modes in fibers having the radius of the order of 10–100 microns. The propagation of these modes along the fiber axis is so slow that they can be governed by extremely small nanoscale changes of the optical fiber radius. This phenomenon is exploited in SNAP (surface nanoscale axial photonics), a new platform for fabrication of miniature super-low-loss photonic integrated circuits with unprecedented sub-angstrom precision. The SNAP theory and applications are overviewed. The third part of this review describes methods of characterization of the radius variation of microfibers and regular optical fibers with sub-nanometer precision.

Unveiling temporal correlations characteristic of a phase transition in the output intensity of a fiber laser

We use advanced statistical tools of time-series analysis to characterize the dynamical complexity of the transition to optical wave turbulence in a fiber laser. Ordinal analysis and the horizontal visibility graph applied to the experimentally measured laser output intensity reveal the presence of temporal correlations during the transition from the laminar to the turbulent lasing regimes. Both methods unveil coherent structures with well-defined time scales and strong correlations both, in the timing of the laser pulses and in their peak intensities. Our approach is generic and may be used in other complex systems that undergo similar transitions involving the generation of extreme fluctuations.

Optical turbulence and spectral condensate in fibre lasers

We study optical wave turbulence in Raman fibre lasers using particular examples of 13 km and 22 km long Fabry-Perot resonators. We demonstrate that the sign of the cavity dispersion has a critical impact on the spectral and temporal properties of generated radiation that are directly relevant to the fibre laser performance. For a normal dispersion, we observe in numerical modelling an intermediate state with an extremely narrow spectrum (condensate), which experiences instability and a sharp transition to a strongly fluctuating regime with a wider spectrum. The experimental results for the generated spectra demonstrate a good match with numerical simulations. © 2011 IEEE.

A költségvetési hiány politikai gazdaságtana (The political economy of budgetary deficit)

A fejlett ipari országokra a hetvenes évektől mind inkább jellemző tartós költségvetési hiányt sem a keynesi, sem pedig a neoklasszikus elmélet nem tudta kielégítően magyarázni. Az új politikai gazdaságtan azonban, úgy tűnik, sikerrel tárta fel nemcsak a tartós hiány és a növekvő eladósodottság okait, hanem a fiskális politikai teljesítményben országok között és időben mutatkozó jelentős eltérések forrásait is. A siker elsősorban annak köszönhető, hogy az új politikai gazdaságtan a költségvetési politika alakításának politikai és intézményi korlátai felé fordult, azzal a nem titkolt szándékkal, hogy kiterjessze a főáramú közgazdaságtan határait, és beépítse modelljeibe a gazdaságpolitikai döntéshozatal folyamatát. Tanulmányunkban négy átfogó magyarázatot tekintünk át - ezek: 1. az adósságállomány stratégiai használata, 2. a stabilizáció elodázása, 3. a politikai és választási rendszerek különbözősége és 4. a gyenge vagy széttöredezett végrehajtói hatalom -, azzal az egyértelmű igénnyel, hogy a szokásos pozitív elemzést normatív vizsgálódással egészítsük ki. / === / Neither Keynesian nor Neoclassical theory managed to explain adequately the increasingly typical state of chronic budgetary deficit found in developed industrial countries since the 1970s. But the new political economy seems to have revealed the causes of the chronic deficit and mounting indebtedness and of the reasons for the marked differences in fiscal-policy performance between countries and periods. The success can be ascribed primarily to the fact that the new political economy turned to the political and institutional constraints on the formation of budgetary policy, with the unconcealed aim of broadening the bounds of mainstream economics and building the policy-making process into it. The study examines four comprehensive explanations: 1. strategic use of debt stock, 2. postponement of stabilization, 3. differences of political and electoral systems, and 4. weak or fragmented executive power, with the clear intention of complementing the customary positive analysis with a normative examination.

Sustainability within the Social Assistance System of the Republic of South Africa

The Republic of South Africa is a unique place on the African continent: it was the only place which had a bloodless transition process when the regime changed from a minority government to a democratic one. During the transition period unemployment was at a level of 13 percent, however it rose to 30 percent in just six years time. In the paper we analyse what kind of attempts does the government make in order to sustain the social assistance system, and keep its promise to the voters by providing better living conditions and protection as opposed to apartheid.

A globálisan növekvő hulladékmennyiség és a kezelésére irányuló nemzetközi törekvések (International efforts to cope with globally increasing waste amounts)

Sokoldalú nemzetközi megállapodások és programok foglalkoznak a hulladékok keletkezésének és az országhatárokon átterjedő hatásainak problémájával, a nemzetközi együttműködést szükségessé tevő megoldásokkal. A leginkább átfogó megközelítést a probléma hajtóerőinek szentelt globális programok tartalmazzák, de a fenntarthatóság alapelveire támaszkodó termelési eljárásokra és fogyasztási szokásokra, a zöld gazdaságra való áttérést szorgalmazó dokumentumok nem tartalmaznak számon kérhető kötelezettségeket. A konkrétabb hulladékkeletkezési és hatásterjedési ügyekben – mindenekelőtt a veszélyes hulladékok és a nemzeti fennhatóság alá nem tartozó területekre eljutó vagy ott keletkező hulladékok esetében – jóval konkrétabb nemzetközi megállapodások és programok léteznek. Ezek szabályozási, szakpolitikai, technológiai célokat, feladatokat határoznak meg az országok és az érintett ágazati szereplők szintjén is. Egyes problémák kapcsán és egyes térségekben a hulladékgazdálkodás jelentős eredményeket tud felmutatni, de általában véve a nemzetközi megállapodások hatékony végrehajtásával komoly gondok vannak. Továbbá a meglévő nemzetközi eszközök összességükben még teljes körű végrehajtásuk esetén sem lennének képesek ellensúlyozni a hulladékprobléma globális szintű növekedését. Következésképpen további erőfeszítésekre van szükség – minden kormány, érintett nem-kormányzati szervezet és az ágazatok részéről – különösen a megelőzés vonatkozásában. ____ Various multilateral agreements and programmes deal with the problems of waste generation and its transboundary impacts, and those solutions, which necessitate international co-operation. Those global programmes include the most comprehensive approach, which are dedicated to the drivers of these problems, however, these documents promoting the transition to sustainable production and consumption, or to the green economy do not consist of binding commitments. In case of more concrete issues of waste generation and transboundary impacts there are much more concrete international agreements and programmes, especially, for the hazardous waste streams and the waste transmitted to and/or generated in areas outside national jurisdiction. These determine regulatory, policy, technological goals and tasks for the participating countries and the relevant sectors. Significant progress is demonstrated for some specific problems and in certain regions, but in general, there are serious concerns about the efficient implementation of the international agreements in their entirety. Moreover, even if those were fully accomplished, the existing set of the international instruments would be unable to counterweigh the global increase of the waste problem. Consequently, further efforts are needed by all countries, the relevant non-governmental organisations and sectors, primarily in order to prevent the further global escalation of the problem.