Interactions between benthic macroinvertebrates and saltmarsh plants : consequences for saltmarsh restoration and the policy of managed realignment on the coast of SE England.

PhDOver the last half century, the saltmarshes of south east England have undergone an extensive decline, especially the pioneer zone vegetation. These losses have generally been blamed on coastal squeeze resulting from sea level rising against sea walls. There is little evidence to support this hypothesis however, and an alternative hypothesis, based on infaunal invertebrates preventing the establishment of saltmarsh plants was tested. In the managed realignment site at Tollesbury, and the other sites examined, the mudflat fauna was dominated by Nereis (= Hediste) diversicolor and Hydrobia ulvae. In laboratory experiments N. diversicolor and H. ulvae reduced the production of seedlings from seeds of Salicornia europaea agg.. Conversely the presence of S. europaea agg. significantly reduced the normal burrowing activity of N. diversicolor. Invertebrate exclusion experiments established at five sites in south east England facilitated colonisation by saltmarsh plants at some sites (Orplands, the Blythe Estuary, Wallasea Island and Maldon), by excluding large (>3cm) N. diversicolor. However, at the Tollesbury realignment site, the high rate of sediment deposition and the relatively long distance to a source of seeds prevented plant colonisation. This study supports the hypothesis that establishment of saltmarsh vegetation is prevented by infaunal invertebrates,particularly N.diversicolor, which exclude plants through bioturbation, herbivory and granivory. These interactions may help explain the loss of saltmarshes and will reduce the success of future managed realignment schemes which depend upon the colonisation of new intertidal areas by saltmarsh vegetation. Further management of realignment sites will be necessary to encourage saltmarsh development.Ministry of Agriculture, Fisheries and Foo

Men of uncertainty: The social organization of day labourers in contemporary Japan.

Japan is a country strongly associated with strong, long-term relationships, whether they be located within kin- groups, local communities or large industrial enterprises. Yet Japan also has a long tradition of people who have been excluded from these relationships, whether voluntarily (hermits, mendicant monks, etc.) or compulsorily (outcasts etc.). This thesis deals with a contemporary category of people who operate largely outside the certainties of long-term relationships: day labourers. Whereas Japanese industry has become famous for 'life-time employment', my subjects often work under contracts for just one day. Most of them are also excluded from family and mainstream community life, living singly in doya-gai -- small urban districts with cheap hotels which resemble the American skid-row. These districts center on a casual labour market (yoseba), divided between a formal sector (public casual labour exchanges) and an informal sector (jobs negotiated on the street with recruiters often affiliated with yakuza gangs). Fieldwork (1993-5) was conducted mainly in Kotobuki, the Yokohama doya-gai, with brief field-trips to similar districts in Tokyo, Osaka, Nagoya, Kitakyushu and Fukuoka. Most of my informants were Japanese nationals, though Koreans and Filipinos are also briefly discussed. The thesis describes the lives and attitudes of day labourers, and the social organization of the very distinctive districts which they inhabit. Based on participant observation, backed up by historical analysis and cross-cultural comparison, the thesis considers the role of these 'men of uncertainty' in a society which craves certainty. In economic terms, that role is to enable the construction and longshoring industries to adjust to fluctuating demand and changing weather conditions while maintaining a stable core workforce. But day labourers, like other stigmatized minorities, have a parallel cultural role, as an "internal other" in the formation of mainstream Japanese people's identity

The interaction of marine fouling organisms with topography of varied scale and geometry: a review

Many studies have examined the effects of surface topography on the settlement behaviour of marine organisms and this article reviews these investigations with more emphasis on the effects of topography scale. It has been observed that macro topographies (1-100 mm) are generally favoured by marine fouling taxa and are unsuitable for antifouling applications. This is because macro topographies are usually large enough to fit fouling organisms and provide refuge from dangers in the marine environment. Micro topographies had only limited success at reducing fouling from a wide range of marine taxa. The antifouling performance of micro topographies (1 to ≤1000 μm) is dependent on the properties of topography features in terms of symmetry, isotropy, width, length, height/depth, separation distance and average roughness. In terms of the antifouling performance of micro topography, topography geometry may only be of secondary importance in comparison to the size of features itself. It is also noted that hydrodynamic stresses also contribute to the settlement trends of foulers on textured surfaces. Future studies on antifouling topographies should be directed to hierarchical topographies because the mixed topography scales might potentially reduce fouling by both micro and macro organisms. Patterned nano-topographies (1- ≤1000 nm) should also be explored because the antifouling mechanisms of these topographies are not yet clear

A lncRNA fine tunes the dynamics of a cell state transition involving Lin28, let-7 and de novo DNA methylation

Execution of pluripotency requires progression from the naive status represented by mouse embryonic stem cells (ESCs) to a state capacitated for lineage specification. This transition is coordinated at multiple levels. Non-coding RNAs may contribute to this regulatory orchestra. We identified a rodent-specific long non-coding RNA (lncRNA) linc1281, hereafter Ephemeron (Eprn), that modulates the dynamics of exit from naive pluripotency. Eprn deletion delays the extinction of ESC identity, an effect associated with perduring Nanog expression. In the absence of Eprn, Lin28a expression is reduced which results in persistence of let-7 microRNAs, and the up-regulation of de novo methyltransferases Dnmt3a/b is delayed. Dnmt3a/b deletion retards ES cell transition, correlating with delayed Nanog promoter methylation and phenocopying loss of Eprn or Lin28a. The connection from lncRNA to miRNA and DNA methylation facilitates the acute extinction of naive pluripotency, a pre-requisite for rapid progression from preimplantation epiblast to gastrulation in rodents. Eprn illustrates how lncRNAs may introduce species-specific network modulations

Factors influencing the initial establishment of salt marsh vegetation on engineered sea wall terraces in south east England

Sea walls provide vital flood protection for lowland coastal property. We investigated the integrity of a cost-effective method of repairing sea defences, which has potential to create habitat for coastal and salt marsh flora. Experimental stone-gabion and clay-filled terraces were installed as a soft engineered approach to repair damaged sea walls in estuarine embayments in south east England. Changes in the surface heights of sediment and vascular plant colonisation were monitored over a 22 month period. Seven of the 12 terraces were colonised, by 12 species of plant, reaching a maximum of 85% cover. The main drivers of plant colonisation were sediment stability, elevation, exposure and sediment shear strength. Terraces with least change in the surface height of sediments were favourable for plant colonisation. Ordination (Canonical Correspondence Analysis) showed 72% variation in plant distribution explained by elevation (37%), exposure (30%), terrace length and sediment shear strength (5%). Elevation was the most influential variable; recruitment increased as terrace height approached the height of existing marsh (r2 = 0.43). This cost-effective approach has the potential to provide protection to sea walls and create additional habitat for wildlife. Key considerations for the improvement of terrace design and construction are discussed

Tamoxifen for the treatment of myeloproliferative neoplasms: a phase II clinical trial and exploratory analysis

Current therapies for myeloproliferative neoplasms (MPNs) improve symptoms but have limited effect on tumor size. In preclinical studies, tamoxifen restored normal apoptosis in mutated hematopoietic stem/progenitor cells (HSPCs). TAMARIN Phase-II, multicenter, single-arm clinical trial assessed tamoxifen’s safety and activity in patients with stable MPNs, no prior thrombotic events and mutated JAK2V617F, CALRins5 or CALRdel52 peripheral blood allele burden ≥20% (EudraCT 2015-005497-38). 38 patients were recruited over 112w and 32 completed 24w-treatment. The study’s A’herns success criteria were met as the primary outcome ( ≥ 50% reduction in mutant allele burden at 24w) was observed in 3/38 patients. Secondary outcomes included ≥25% reduction at 24w (5/38), ≥50% reduction at 12w (0/38), thrombotic events (2/38), toxicities, hematological response, proportion of patients in each IWG-MRT response category and ELN response criteria. As exploratory outcomes, baseline analysis of HSPC transcriptome segregates responders and non-responders, suggesting a predictive signature. In responder HSPCs, longitudinal analysis shows high baseline expression of JAK-STAT signaling and oxidative phosphorylation genes, which are downregulated by tamoxifen. We further demonstrate in preclinical studies that in JAK2V617F+ cells, 4-hydroxytamoxifen inhibits mitochondrial complex-I, activates integrated stress response and decreases pathogenic JAK2-signaling. These results warrant further investigation of tamoxifen in MPN, with careful consideration of thrombotic risk

Sediment reworking by the burrowing polychaete Hediste diversicolor modulated by environmental and biological factors across the temperate North Atlantic. A tribute to Gaston Desrosiers

International audienceParticle mixing and irrigation of the seabed by benthic fauna (bioturbation) have major impacts on ecosystem functions such as remineralization of organic matter and sediment-water exchange. As a tribute to Prof. Gaston Desrosiers by the Nereis Park association, eighteen laboratories carried out a collaborative experiment to acquire a global snapshot of particle reworking by the polychaete Hediste diversicolor at 16 sites surrounding the Northern Atlantic. Organisms and soft sediments were collected during May – July at different geographical locations and, using a common laboratory protocol, particulate fluorescent tracers (‘luminophores’) were used to quantify particle transport over a 10-day period. Particle mixing was quantified using the maximum penetration depth of tracers (MPD), particle diffusive coefficients (Db), and non-local transport coefficients (r). Non-local coefficients (reflecting centimeter scale transport steps) ranged from 0.4 to 15 yr−1, and were not correlated across sites with any measured biological (biomass, biovolume) or environmental parameters (temperature, grain size, organic matter). Maximum penetration depths (MPD) averaged ~10.7 cm (6.5–14.5 cm), and were similar to the global average bioturbation depth inferred from short-lived radiochemical tracers. MPD was also not correlated with measures of size (individual biomass), but increased with grain size and decreased with temperature. Biodiffusion (Db) correlated inversely with individual biomass (size) and directly with temperature over the environmental range (Q10 ~ 1.7; 5–21 °C). The transport data were comparable in magnitude to rates reported for localized H. diversicolor populations of similar size, and confirmed some but not all correlations between sediment reworking and biological and environmental variables found in previous studies. The results imply that measures of particle reworking activities of a species from a single location can be generally extrapolated to different populations at similar conditions