A new diatom species P. Hallegraeffii sp. Nov. Belonging to the toxic genus Pseudo-nitzschia (Bacillariophyceae) from the East Australian Current

© 2018 Ajani et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. A new species belonging to the toxin producing diatom genus Pseudo-nitzschia, P. hallegraeffii sp. nov., is delineated and described from the East Australian Current (EAC). Clonal cultures were established by single cell isolation from phytoplankton net hauls collected as part of a research expedition in the EAC region in 2016 on the RV Investigator. Cultures were assessed for their morphological and genetic characteristics, their sexual compatibility with other Pseudo-nitzschia species, and their ability to produce domoic acid. Light and transmission electron microscopy revealed cells which differed from their closest relatives by their cell width, rows of poroids, girdle band structure and density of band straie. Phylogenetic analyses based on sequencing of nuclear-encoded ribosomal deoxyribonucleic acid (rDNA) regions showed this novel genotype clustered within the P. delicatissima complex, but formed a discrete clade from its closest relatives P. dolorosa, P. simulans, P. micropora and P. delicatissima. Complementary base changes (CBCs) were observed in the secondary structure of the 3’ nuclear ribosomal transcribed spacer sequence region (ITS2) between P. hallegraeffii sp. nov. and its closest related taxa, P. simulans and P. dolorosa. Under laboratory conditions, and in the absence of any zooplankton cues, strains of P. hallegraeffii sp. nov. did not produce domoic acid (DA) and were not sexually compatible with any other Pseudo-nitzschia clones tested. A total of 18 Pseudo-nitzschia species, including three confirmed toxigenic species (P. cuspidata, P. multistriata and P. australis) have now been unequivocally confirmed from eastern Australia

The microbiome of the cosmopolitan diatom leptocylindrus reveals significant spatial and temporal variability

Copyright © 2018 Ajani, Kahlke, Siboni, Carney, Murray and Seymour. The ecological interactions between phytoplankton and marine bacteria have important implications for the productivity and biogeochemistry of ocean ecosystems. In this study we characterized the microbial assemblages associated with multiple isolates of the ecologically important diatom Leptocylindrus using amplicon sequencing of the 16S rRNA gene, to examine levels of conservation of the microbiome across closely related species or strains. We also assessed if the microbiome structure of a given diatom strain was dependent on the location from which it was isolated and if the microbiome of cultured isolates significantly changed overtime from the seawater in which they were isolated. The bacterial assemblages from 36 strains belonging to three species (Leptocylindrus danicus, Leptocylindrus convexus, and Leptocylindrus aporus) isolated from six locations spanning > 1000 km of south east Australian coastline over 1 year, were dominated by the Rhodobacteraceae (∼60%) and the Flavobacteriaceae (∼10%). Across all strains, only one 'core OTU' (Roseovarius sp.) was identified across all samples. We observed no significant differences in bacterial community composition between diatom species. Significant differences in microbiome structure were, however, observed between diatom strains collected at different sampling times and from differing locations, albeit these two factors were coupled. Moreover, while bacterial communities under domestication varied from the seawater in which they were isolated, they remained specific to the location/month of origin, i.e., different regions and time points harbored distinct bacterial communities. Our study delivers new knowledge in relation to diatom-bacterial associations, revealing that the location/time from which a diatom is isolated plays an important role in shaping its microbiome

Authority, Power and Distributed Leadership

This is the Accepted Manuscript version of an article accepted for publication in Management and Education following peer review. The version of record, Philip Woods, ‘Authority, power and distributed leadership’, Management and Education, Vol 30(4): 155-160, first published online 28 September 2016, is available online via doi: 10.1177/0892020616665779 © 2016 British Educational Leadership, Management & Administration Society (BELMAS) Published by SAGE.A much greater understanding is needed of power in the practice of distributed leadership. This article explores how the concept of social authority might be helpful in achieving this. It suggests that the practice of distributed leadership is characterized by multiple authorities which are constructed in the interactions between people. Rather than there being a uniform hierarchy (relatively flat or otherwise) of formal authority, organizational members may be ‘high’ in some authorities and ‘low’ in others, and people’s positioning in relation to these authorities is dynamic and changeable. The article maps different forms of authorities, provides illustrations from educational institutions, and concludes with implications for educational leadership. A key conclusion is that everyone is involved in the ongoing production of authorities by contributing to who is accepted as or excluded from exercising authority and leadershipPeer reviewedFinal Accepted Versio

Bloom drivers of the potentially harmful dinoflagellate Prorocentrum minimum (Pavillard) Schiller in a south eastern temperate Australian estuary

© 2018 Elsevier Ltd Harmful algal blooms are an increasing concern in the estuarine reaches of the Hawkesbury-Nepean River, one of the largest coastal rivers systems in south eastern Australia. In the austral spring of 2016, an unprecedented bloom of the harmful mixotrophic dinoflagellate Prorocentrum minimum occurred in Berowra Creek (maximum cell abundance 1.9E+06 cells L−1, 89% of the total phytoplankton community), a major tributary of this river system. In response to this bloom, our study utilises an estuary-wide, thirteen-year time series of phytoplankton abundance and environmental data to examine the spatial and temporal patterns of this harmful alga and its potential bloom drivers in this system. P. minimum cell densities and environmental parameters varied over large spatial scales, with sites located in the main channel of the estuary significantly differing from those in the more urbanized tributary of Berowra Creek. Generalised additive modelling outputs suggested that blooms of P. minimum are complex, but generally corresponded to a spatial gradient of eutrophication and salinity, whereby P. minimum growth and concomitant high chlorophyll-a concentrations were enhanced at sites that were generally less saline and more eutrophic than others. Furthermore, temporal patterns suggested that blooms occurred abruptly and lasted up to three weeks, most often during the austral autumn to spring. While significant correlations were observed between rainfall and nutrients at all other sites, suggesting a pathway for nutrient availability, the association between rainfall and nutrient delivery was generally not observed in Berowra Creek (a 15-m deep site) suggesting that a continual supply of nutrients, coupled with unique bathymetry and water residence time at this site, are the most likely contributing factors to phytoplankton growth. This study presents the most comprehensive examination of P. minimum in any southern hemisphere estuary to date and highlights the importance of continued monitoring of HABs and the important role that anthropogenic inputs have in driving blooms of P. minimum in this oyster-growing river/estuary system

Knowledge Exchange Through Science Diplomacy to Assist Disaster Risk Reduction. Progress in Disaster Science

This paper analyses science diplomacy efforts to reduce disaster risks and proposes establishing national knowledge exchange centers (KECs) to help individual states adhere to their Sendai Framework goals. KECs are considered to be interconnected globally and work together to promote resilience efforts by facilitating sharing of information and strategies in risk monitoring, assessment, and ultimately reduction across the globe. KECs can provide high-quality scientific evidence for informed decisionmaking along with a component related to disaster science media to ensure that appropriate knowledge reaches a variety of people who need it in different forms tailored for them. KECs can promote transdisciplinary education in disaster-related science diplomacy (i.e., disaster diplomacy). The United Nations Office for Disaster Risk Reduction (UNDRR) and the International Science Council (ISC) can provide assistance to KECs through UNDRR National Platforms and ISC Members

Improved model identification for non-linear systems using a random subsampling and multifold modelling (RSMM) approach

In non-linear system identification, the available observed data are conventionally partitioned into two parts: the training data that are used for model identification and the test data that are used for model performance testing. This sort of 'hold-out' or 'split-sample' data partitioning method is convenient and the associated model identification procedure is in general easy to implement. The resultant model obtained from such a once-partitioned single training dataset, however, may occasionally lack robustness and generalisation to represent future unseen data, because the performance of the identified model may be highly dependent on how the data partition is made. To overcome the drawback of the hold-out data partitioning method, this study presents a new random subsampling and multifold modelling (RSMM) approach to produce less biased or preferably unbiased models. The basic idea and the associated procedure are as follows. First, generate K training datasets (and also K validation datasets), using a K-fold random subsampling method. Secondly, detect significant model terms and identify a common model structure that fits all the K datasets using a new proposed common model selection approach, called the multiple orthogonal search algorithm. Finally, estimate and refine the model parameters for the identified common-structured model using a multifold parameter estimation method. The proposed method can produce robust models with better generalisation performance

A Comparative Analysis of Methods (LC-MS/MS, LC-MS and Rapid Test Kits) for the Determination of Diarrhetic Shellfish Toxins in Oysters, Mussels and Pipis

Rapid methods for the detection of biotoxins in shellfish can assist the seafood industry and safeguard public health. Diarrhetic Shellfish Toxins (DSTs) are produced by species of the dinoflagellate genus Dinophysis, yet the comparative efficacy of their detection methods has not been systematically determined. Here, we examined DSTs in spiked and naturally contaminated shellfish–Sydney Rock Oysters (Saccostrea glomerata), Pacific Oysters (Magallana gigas/Crassostrea gigas), Blue Mussels (Mytilus galloprovincialis) and Pipis (Plebidonax deltoides/Donax deltoides), using LC-MS/MS and LC-MS in 4 laboratories, and 5 rapid test kits (quantitative Enzyme-Linked Immunosorbent Assay (ELISA) and Protein Phosphatase Inhibition Assay (PP2A), and qualitative Lateral Flow Assay (LFA)). We found all toxins in all species could be recovered by all laboratories using LC-MS/MS (Liquid Chromatography—tandem Mass Spectrometry) and LC-MS (Liquid Chromatography—Mass Spectrometry); however, DST recovery at low and mid-level concentrations (0.86 mg/kg) was higher (60–262%). While no clear differences were observed between shellfish, all kits delivered an unacceptably high level (25–100%) of falsely compliant results for spiked samples. The LFA and the PP2A kits performed satisfactorily for naturally contaminated pipis (0%, 5% falsely compliant, respectively). There were correlations between spiked DSTs and quantitative methods was highest for LC-MS (r2 = 0.86) and the PP2A kit (r2 = 0.72). Overall, our results do not support the use of any DST rapid test kit as a stand-alone quality assurance measure at this tim

18F-GE-180: a novel TSPO radiotracer compared to 11C-R-PK11195 in a preclinical model of stroke

PURPOSE: Neuroinflammation plays a critical role in various neuropathological conditions, and hence there is renewed interest in the translocator protein (TSPO) as a biomarker of microglial activation and macrophage infiltration in the brain. This is reflected in the large amount of research conducted seeking to replace the prototypical PET radiotracer 11C-R-PK11195 with a TSPO ligand with higher performance. Here we report the in vivo preclinical investigation of the novel TSPO tracer 18F-GE-180 in a rat model of stroke. METHODS: Focal cerebral ischaemia was induced in Wistar rats by 60-min occlusion of the middle cerebral artery (MCAO). Brain damage was assessed 24 h after MCAO by T2 MRI. Rats were scanned with 11C-R-PK11195 and 18F-GE-180 5 or 6 days after MCAO. Specificity of binding was confirmed by injection of unlabelled R-PK11195 or GE-180 20 min after injection of 18F-GE-180. In vivo data were confirmed by ex vivo immunohistochemistry for microglial (CD11b) and astrocytic biomarkers (GFAP). RESULTS: 18F-GE-180 uptake was 24 % higher in the core of the ischaemic lesion and 18 % lower in the contralateral healthy tissue than that of 11C-R-PK11195 uptake (1.5 ± 0.2-fold higher signal to noise ratio). We confirmed this finding using the simplified reference tissue model (BPND = 3.5 ± 0.4 and 2.4 ± 0.5 for 18F-GE-180 and 11C-R-PK11195, respectively, with R 1 = 1). Injection of unlabelled R-PK11195 or GE-180 20 min after injection of 18F-GE-180 significantly displaced 18F-GE-180 (69 ± 5 % and 63 ± 4 %, respectively). Specificity of the binding was also confirmed by in vitro autoradiography, and the location and presence of activated microglia and infiltrated macrophages were confirmed by immunohistochemistry. CONCLUSION: The in vivo binding characteristics of 18F-GE-180 demonstrate a better signal to noise ratio than 11C-R-PK11195 due to both a better signal in the lesion and lower nonspecific binding in healthy tissue. These results provide evidence that 18F-GE-180 is a strong candidate to replace 11C-R-PK11195

Second-order Democratic Aggregation

Aggregated second-order features extracted from deep convolutional networks have been shown to be effective for texture generation, fine-grained recognition, material classification, and scene understanding. In this paper, we study a class of orderless aggregation functions designed to minimize interference or equalize contributions in the context of second-order features and we show that they can be computed just as efficiently as their first-order counterparts and they have favorable properties over aggregation by summation. Another line of work has shown that matrix power normalization after aggregation can significantly improve the generalization of second-order representations. We show that matrix power normalization implicitly equalizes contributions during aggregation thus establishing a connection between matrix normalization techniques and prior work on minimizing interference. Based on the analysis we present {\gamma}-democratic aggregators that interpolate between sum ({\gamma}=1) and democratic pooling ({\gamma}=0) outperforming both on several classification tasks. Moreover, unlike power normalization, the {\gamma}-democratic aggregations can be computed in a low dimensional space by sketching that allows the use of very high-dimensional second-order features. This results in a state-of-the-art performance on several datasets

Understanding lived experiences and perceptions of resilience in black and South Asian Muslim children living in East London: a qualitative study protocol.

INTRODUCTION: It is important to promote resilience in preadolescence; however, there is limited research on children's understandings and experiences of resilience. Quantitative approaches may not capture dynamic and context-specific aspects of resilience. Resilience research has historically focused on white, middle-class Western adults and adolescents, creating an evidence gap regarding diverse experiences of resilience in middle childhood which could inform interventions. East London's Muslim community represents a diverse, growing population. Despite being disproportionately affected by deprivation and racial and cultural discrimination, this population is under-represented in resilience research. Using participatory and arts-based methods, this study aims to explore lived experiences and perceptions of resilience in black and South Asian Muslim children living in East London. METHODS AND ANALYSIS: We propose a qualitative study, grounded in embodied inquiry, consisting of a participatory workshop with 6-12 children and their parents/carers to explore lived experiences and perceptions of resilience. Participants will be identified and recruited from community settings in East London. Eligible participants will be English-speaking Muslims who identify as being black or South Asian, have a child aged 8-12 years and live in East London. The workshop (approx. 3.5 hours) will take place at an Islamic community centre and will include body mapping with children and a focus group discussion with parents/carers to explore resilience perspectives and meanings. Participants will also complete a demographic survey. Workshop audio recordings will be transcribed verbatim and body maps and other paper-based activities will be photographed. Data will be analysed using systematic visuo-textual analysis which affords equal importance to visual and textual data. ETHICS AND DISSEMINATION: The Queen Mary Ethics of Research Committee at Queen Mary University of London has approved this study (approval date: 9 October 2023; ref: QME23.0042). The researchers plan to publish the results in peer-reviewed journals and present findings at academic conferences