Solitary waves in a stochastic parametrically forced nonlinear Schr\"odinger equation

We study a parametrically forced nonlinear Schr\"odinger (PFNLS) equation, driven by multiplicative translation-invariant noise. We show that a solitary wave in the stochastic equation is orbitally stable on a timescale which is exponential in the inverse square of the noise strength. We give explicit expressions for the phase shift and fluctuations around the shifted wave which are accurate to second order in the noise strength. This is done by developing a new perspective on the phase-lag method introduced by Kr\"uger and Stannat. Additionally, we show well-posedness of the equation in the fractional Bessel space $H^{s}$ for any $s \in [0,\infty)$, demonstrating persistence of regularity.Comment: 32 pages, this work supersedes arXiv:2208.01945, stability results on solitary waves adde

Evaluatie Opvangbeleid 2005-2008 overwinterende ganzen en smienten. Deelrapport 10. Hebben overwinterende ganzen invloed op de weidevogelstand?

Dit rapport richt zich op de vraag of de sterk toegenomen dichtheden ganzen in bepaalde gebieden mede verantwoordelijk kunnen zijn voor de achteruitgang van de weidevogels ter plekke. Gebruik makend van data verzameld in de periode 1990-2005 in het kader van het weidevogelmeetnet en de watervogeltellingen in ganzentelgebieden werd onderzocht in hoeverre gebieden met hoge dichtheden ganzen overlappen met gebieden met hoge dichtheden weidevogels. De effecten van hoge dichtheden overwinterende ganzen op in Nederland broedende weidevogels lijken verwaarloosbaar of positief. Resultaten van onderzoek van SOVON en Alterr

Coupling production networks and regional assets in manufacturing clusters

Paradoxically, the ongoing process of globalisation goes hand in hand with a surge of interest in the ‘local’ sources of firm competitiveness. In this paper, we develop a frame of analysis that helps to understand ‘coupling’ of production networks and regional development. Our aim is to reflect on the ‘spatiality’ of different types of networks, and to study the dynamic coupling process between these networks and regional assets. We apply the framework to two case studies – shipbuilding in Turku and machine building in Porto. Our analysis points towards the relevance of regional assets facilitating this coupling process and in strengthening regions as magnets for global production networks, reinforcing the long term sustainability of different types of clusters

Assessing the impact of tailored biosecurity advice on farmer behaviour and pathogen presence in beef herds in England and Wales

The term ‘biosecurity’ encompasses many measures farmers can take to reduce the risk of pathogen incursion or spread. As the best strategy will vary between settings, veterinarians play an important role in assessing risk and providing advice, but effectiveness requires farmer acceptance and implementation. The aim of this study was to assess the effectiveness of specifically-tailored biosecurity advice packages in reducing endemic pathogen presence on UK beef suckler farms. One hundred and sixteen farms recruited by 10 veterinary practices were followed for three years. Farms were randomly allocated to intervention (receiving specifically-tailored advice, with veterinarians and farmers collaborating to develop an improved biosecurity strategy) or control (receiving general advice) groups. A spreadsheet-based tool was used annually to attribute a score to each farm reflecting risk of entry or spread of bovine viral diarrhoea virus (BVDV), bovine herpesvirus-1 (BHV1), Mycobacterium avium subsp. paratuberculosis (MAP), Leptospira interrogans serovar hardjo (L. hardjo) and Mycobacterium bovis (M. bovis). Objectives of these analyses were to identify evidence of reduction in risk behaviours during the study, as well as evidence of reductions in pathogen presence, as indications of effectiveness. Risk behaviours and pathogen prevalences were examined across study years, and on intervention compared with control farms, using descriptive statistics and multilevel regression. There were significant reductions in risk scores for all five pathogens, regardless of intervention status, in every study year compared with the outset. Animals on intervention farms were significantly less likely than those on control farms to be seropositive for BVDV in years 2 and 3 and for L. hardjo in year 3 of the study. Variations by study year in animal-level odds of seropositivity to BHV1 or MAP were not associated with farm intervention status. All farms had significantly reduced odds of BHV1 seropositivity in year 2 than at the outset. Variations in farm-level MAP seropositivity were not associated with intervention status. There were increased odds of M. bovis on intervention farms compared with control farms at the end of the study. Results suggest a structured annual risk assessment process, conducted as a collaboration between veterinarian and farmer, is valuable in encouraging improved biosecurity practices. There were some indications, but not conclusive evidence, that tailored biosecurity advice packages have potential to reduce pathogen presence. These findings will inform development of a collaborative approach to biosecurity between veterinarians and farmers, including adoption of cost-effective strategies effective across pathogens