A continuous time cyclical growth model for the Federal Republic of Germany: Construction, estimation and analysis

This paper seeks to unify and extend a number of recent directions in macro-economic research. Firstly, there has been a tendency to introduce new factors and to unify their treatment. Thus imported raw materials together with floating exchange rates are now an established part of the literature. This has naturally led to the introduction of real wage rigidity as an essential element in the study of transmission of impulses between countries. Yet the unified treatment of such factors in a macro-econometric model is rare, the empirical work being mainly of the Single equation on reduced form variety. The empirical work on real wages and employment is a good example (see Sachs, 1983, for a review). In addition most macro-econometric modeis are Keynesian in construction, the supply side being relatively poorly developed.

Trade policy in West Germany.

Außenwirtschaftspolitik; Deutschland;

First record of verticillium wilt (Verticillium longisporum) in winter oilseed rape in the UK

Verticillium longisporum is an important pathogen of oilseed rape (OSR) and vegetable brassicas in several European countries, but has not been reported previously in the UK (Karapapa et al., 1997; Steventon et al., 2002). In 2007, Verticillium wilt was suspected in UK crops of winter OSR (W-OSR) on cv. Castille in Romney Marsh, Kent and on cv. Barrel near Hereford. At these two locations, 32 and 10% of the plants, respectively, appeared to be affected, but the presence of stem canker may have masked some infections. Symptoms were first seen as the crops began to ripen (seeds green-brown to brown, Growth Stage: 6,4-6,5) and included brown and dark grey vertical bands on the stems from soil level into the branches, and premature ripening of some branches (Fig. 1). Microsclerotia were observed on stem samples collected in the field (Fig. 2), suggesting V. longisporum as the causal agent. Cultures were prepared from field samples by immersing stem pieces in 5% sodium hypochlorite solution for one minute, washing twice in sterile distilled water and plating onto potato dextrose agar containing 25 mg/l streptomycin sulphate. Isolates from three plants per outbreak were identified morphologically as V. longisporum. Mean conidial dimensions (25 spores per isolate) were 8.80-9.65 μm (length) and 2.50-2.85 μm (width) and all isolates produced elongated microsclerotia, characters typical of V. longisporum (Karapapa et al., 1997). The identity was confirmed by PCR using species-specific primers (Steventon et al., 2002) and, as a member of the α sub-group, by direct sequencing of the amplicons from primer pairs ITS4-ITS5 and DB19-DB22 (Collins et al., 2003; 2005). Sequences for isolate 003 from Kent were deposited in GenBank (Accession Nos. HQ702376 and HQ702377). All isolates tested from 2008 and 2009 were identical with previously deposited sequences for European OSR isolates (e.g. AF363992 and AF363246 respectively). Pathogenicity was confirmed by inoculating three OSR cv. Castille seedlings per isolate using the root dip technique with 1 x 106 spores/ml (Karapapa et al., 1997) under heated glasshouse conditions at 19°C. Leaf yellowing and blackening of the leaf veins were found 26 days after inoculation (Fig. 3). Yellowing affecting the three oldest leaves increased for seven to nine days. After five weeks the final mean leaf area affected was 63-78% with no differences between isolates. No leaf yellowing occurred in the controls. After five weeks, V. longisporum was re-isolated from all the inoculated seedlings, but not from the non-inoculated controls. In June 2008, infection of W-OSR crops in different fields on the same farms was found on cv. Es Astrid in Kent (56% incidence) and on cv. Lioness in Hereford (15% incidence). The Kent farm had been growing W-OSR alternating with winter wheat for at least 10 years whilst the Hereford farm had grown W-OSR one year in four. These short rotations of OSR may be contributing to the appearance of this disease. This study confirms the identification of V. longisporum on any host in the UK, through molecular studies and detailed spore measurements that were not reported in an earlier review (Gladders, 2009). This pathogen occurs in several European countries and, since OSR may be traded freely, following a Defra consultation, no statutory plant health action is to be taken

Stratified dispersal and increasing genetic variation during the invasion of Central Europe by the western corn rootworm, Diabrotica virgifera virgifera

Invasive species provide opportunities for investigating evolutionary aspects of colonization processes, including initial foundations of populations and geographic expansion. Using microsatellite markers and historical information, we characterized the genetic patterns of the invasion of the western corn rootworm (WCR), a pest of corn crops, in its largest area of expansion in Europe: Central and South-Eastern (CSE) Europe. We found that the invaded area probably corresponds to a single expanding population resulting from a single introduction of WCR and that gene flow is geographically limited within the population. In contrast to what is expected in classical colonization processes, an increase in genetic variation was observed from the center to the edge of the outbreak. Control measures against WCR at the center of the outbreak may have decreased effective population size in this area which could explain this observed pattern of genetic variation. We also found that small remote outbreaks in southern Germany and north-eastern Italy most likely originated from long-distance dispersal events from CSE Europe. We conclude that the large European outbreak is expanding by stratified dispersal, involving both continuous diffusion and discontinuous long-distance dispersal. This latter mode of dispersal may accelerate the expansion of WCR in Europe in the future

Complex patterns of local adaptation in teosinte

Populations of widely distributed species often encounter and adapt to specific environmental conditions. However, comprehensive characterization of the genetic basis of adaptation is demanding, requiring genome-wide genotype data, multiple sampled populations, and a good understanding of population structure. We have used environmental and high-density genotype data to describe the genetic basis of local adaptation in 21 populations of teosinte, the wild ancestor of maize. We found that altitude, dispersal events and admixture among subspecies formed a complex hierarchical genetic structure within teosinte. Patterns of linkage disequilibrium revealed four mega-base scale inversions that segregated among populations and had altitudinal clines. Based on patterns of differentiation and correlation with environmental variation, inversions and nongenic regions play an important role in local adaptation of teosinte. Further, we note that strongly differentiated individual populations can bias the identification of adaptive loci. The role of inversions in local adaptation has been predicted by theory and requires attention as genome-wide data become available for additional plant species. These results also suggest a potentially important role for noncoding variation, especially in large plant genomes in which the gene space represents a fraction of the entire genome

Is there indirect selection on female extra-pair reproduction through cross-sex genetic correlations with male reproductive fitness?

We thank Peter Arcese, Lukas Keller and Pirmin Nietlisbach for their support and long-term contributions to the dataset; the Tsawout and Tseycum First Nations bands for access to Mandarte; everyone who contributed to long-term data collection; and Greta Bocedi for helpful comments. JMR and MEW were funded by the European Research Council and NSERC (Canada) provided invaluable long-term support for the field study. The authors declare no conflict of interest. The doi for our data is 10.5061/dryad.p6df410.Peer reviewedPublisher PD

Why health visiting? Examining the potential public health benefits from health visiting practice within a universal service: A narrative review of the literature

INTRODUCTION: There is increasing international interest in universal, health promoting services for pregnancy and the first three years of life and the concept of proportionate universalism. Drawing on a narrative review of literature, this paper explores mechanisms by which such services might contribute to health improvement and reducing health inequalities. OBJECTIVES: Through a narrative review of empirical literature, to identify: DESIGN: The paper draws upon a scoping study and narrative review. REVIEW METHODS: We used three complementary approaches to search the widely dispersed literature: Our key inclusion criterion was information about health visiting practice. We included empirical papers from United Kingdom (UK) from 2004 to February 2012 and older seminal papers identified in search (3), identifying a total of 348 papers for inclusion. A thematic content analysis compared the older (up to 2003) with more recent research (2004 onwards). RESULTS: The analysis revealed health visiting practice as potentially characterized by a particular 'orientation to practice.' This embodied the values, skills and attitudes needed to deliver universal health visiting services through salutogenesis (health creation), person-centredness (human valuing) and viewing the person in situation (human ecology). Research about health visiting actions focuses on home visiting, needs assessment and parent-health visitor relationships. The detailed description of health visitors' skills, attitudes, values, and their application in practice, provides an explanation of how universal provision can potentially help to promote health and shift the social gradient of health inequalities. CONCLUSIONS: Identification of needs across an undifferentiated, universal caseload, combined with an outreach style that enhances uptake of needed services and appropriate health or parenting information, creates opportunities for parents who may otherwise have remained unaware of, or unwilling to engage with such provision. There is a lack of evaluative research about health visiting practice, service organization or universal health visiting as potential mechanisms for promoting health and reducing health inequalities. This paper offers a potential foundation for such research in future

A practice research study concerning homeless service user involvement with a programme of social support work delivered in a specialized psychological trauma service

Homeless people are a population known to be highly vulnerable to trauma, in triggering events to becoming homeless and the considerable social isolation, discrimination, and adversity suffered when homeless. Currently, there is a paucity of research into mental health service delivery to homeless persons and the influence it imparts in individual lives. This article presents a qualitative ‘practice research’ study into a pilot programme of social support work delivered in a specialized psychological trauma service to homeless service users. The programme was grounded in a non-directive, person-centred approach and staffed by student social workers. The study aim was to explore the support work programme as it was received by service users domiciled in supported housing for homeless persons, encompassing experiencing the programme, worker-service user engagement and contextual influences bearing upon positive outcomes. Narrative interviews gathered the impressions of service users and support workers and the data arising from these interviews was analysed thematically. Service user participants valued support work that combined practical and relational elements, but would have preferred a longer-term involvement. They also spoke of feelings of disconnection and estrangement from their peers in the supported accommodation and their families. The worker participants valued the flexibility of person-centred work tailored to service users' individual needs and echoed service user concerns around the short-term nature of their involvement. Psychiatric nurses carrying out, or supervising, mental health support work with homeless service users should be mindful of the potential impact of temporary staffing arrangements on continuity of care. They should also consider how working from a person-centred perspective and addressing client's practical needs may aid in developing rapport and trust with homeless service users

Nonergodicity transitions in colloidal suspensions with attractive interactions

The colloidal gel and glass transitions are investigated using the idealized mode coupling theory (MCT) for model systems characterized by short-range attractive interactions. Results are presented for the adhesive hard sphere and hard core attractive Yukawa systems. According to MCT, the former system shows a critical glass transition concentration that increases significantly with introduction of a weak attraction. For the latter attractive Yukawa system, MCT predicts low temperature nonergodic states that extend to the critical and subcritical region. Several features of the MCT nonergodicity transition in this system agree qualitatively with experimental observations on the colloidal gel transition, suggesting that the gel transition is caused by a low temperature extension of the glass transition. The range of the attraction is shown to govern the way the glass transition line traverses the phase diagram relative to the critical point, analogous to findings for the fluid-solid freezing transition.Comment: 11 pages, 7 figures; to be published in Phys. Rev. E (1 May 1999