Reference Material Development for Paralytic Shellfish Poisoning Toxins and Associated Analytical Applications

Food poisoning incidences relating to marine biotoxins are a global phenomenon and have the potential to severely impact the aquaculture industry. As a result, and as a legislative requirement in the European Union (EU), many countries have implemented monitoring programmes for these compounds but their success relies on the availability of certain quality assurance tools, two of which are reference materials (RMs) and proficiency testing. The limited amounts of RMs, in particular matrix certified reference materials (CRMs) for paralytic shellfish poisoning (PSP) toxins has been a limiting factor in the implementation of alternatives to the mouse bioassay for routine monitoring programmes. Various stabilisation procedures were investigated to ascertain the applicability of each for preparing RMs for various uses including internal QA/QC, proficiency testing and as candidates for certification. The beginning of these studies coincided with a large PSP toxic event in Icelandic waters. During that period mussels from two production sites on the north and north-west coasts of Iceland accumulated PSP toxins to levels many times over the EU regulatory limit. Mussels sampled during this period were characterised and presented along with phytoplankton data from the same period and presented as a first report of PSP toxins from Icelandic waters. Large quantities of naturally contaminated mussel tissues were harvested during this period for use in these studies. Various stabilisation procedures were investigated, such as thermal treatment, the use of preserving additives, high pressure processing (HPP) and freeze drying, for their applicability in preparing RMs for PSP toxins. Extensive characterisation of the materials was performed through homogeneity and short and long-term stability studies using two LC-FLD methods to evaluate each technique in reducing levels of degradation, biotransformations or epimerization. Freeze drying proved the most effective technique evaluated and this procedure was used to prepare RMs in two shellfish species, Pacific oyster (Crassostrea gigas) and blue mussels (Mytilus edulis). The technique improved the stability of all toxins assessed compared to untreated controls. A successful feasibility study was carried out in a C. gigas matrix which resulted in the production of a medium scale RM as a candidate CRM. Certification of this material was not carried out during the course of these studies however. Although freeze drying proved the most effective in stabilising both the tissue matrix and the PSP toxins themselves, the labour intensive nature of the procedure as well as the significant per unit production costs led to alternative RM techniques being investigated. HPP of a C. gigas tissue matrix was performed and it provided an extremely effective technique for stabilising the toxins through a reduction of microbial activity. Stability studies showed the technique reduces or eliminates toxin degradation and epimerisation compared to untreated control materials with the technique potentially having applications in CRM development, although a full feasibility study was not conducted. The use of heat treatment and preserving additives provided the simplest and most cost effective stabilisation procedure investigated with both techniques, particularly when combined, improving toxin and matrix stability compared to untreated controls. Each technique was evaluated separately and combined in one tissue matrix, M. edulis and applications for materials prepared by this procedure were examined. Combining the use of preserving additives with a thermal pre-treatment step provided sufficiently stable and homogenous RMs which were used as an internal QA/QC tool in the Irish National Monitoring Programme (NMP) and in proficiency testing (PT) schemes operated by QUASIMEME and VEREFIN. Data from a RM prepared by the combined techniques above and used in the Irish NMP over a two year period provided evidence for the long-term stability of the material using a classical stability model and was used to calculate an expanded uncertainty of measurement for the method used for official control purposes at the Marine Institute. Materials prepared by these combined techniques were also used to develop the first commercially available PT scheme for PSP toxins. Data is presented from the first six years of this development exercise from participants using a wide array of methodologies. Data showed the improvement of participants over this period but found statistical differences in the datasets of both LC-FLD methods employed by some subscribers in determining dcSTX and GTX2,3. A material was also prepared for use in a separate PT scheme operated by VEREFIN which highlights the wide applicability of these RMs. The techniques investigated during these studies have multiple applications in method development, as QA/QC tools, in CRM preparation and in proficiency testing schemes

‘I’m a red-blooded male’: Understanding men’s experiences of domestic abuse through a feminist lens

The ways in which gendered expectations of women are used to maintain power and control by male perpetrators of domestic abuse are now well understood. It is also increasingly recognised that men can be victims of domestic abuse. This has led to calls to de-gender theories of violence and abuse, and arguments that the feminist theories which underpin many interventions are outdated. We draw on the experiences of 344 men using a helpline for male victim–survivors of domestic abuse to show that patriarchal constructions of relationships, femininity and masculinity, which underpin women’s experiences of domestic abuse by men are also central to understanding men’s experiences of domestic abuse by women. We propose that men’s victimisation by women perpetrators is not incompatible with feminist understandings of domestic abuse. Rather, that the influence of patriarchal norms in men’s victimisation accentuates the importance of gender in understanding and responding to domestic abuse

The invisibility of men's practices: A discourse analysis of gender in domestic violence policy

Domestic violence is a phenomenon which is both gendered and social, in that it is perpetrated overwhelmingly by men against women, and is pervasive throughout all areas of society. Yet the history of the response to domestic violence by the state has often been one of inaction and failure. This master's thesis explores how the governments of Finland and the United Kingdom approach the issue today, by examining how policy around domestic violence is discursively gendered, constructed, and problematised. This is carried out through an analysis of two national policy documents from each country, published between 2008 and 2011, which focus on domestic violence or violence against women more broadly. These texts are studied by a combination of discourse analysis methods and a problematisation approach to policy analysis. The UK and Finland were chosen for comparison because of the different ways in which feminists have traditionally interacted with the state in the two countries. In Britain, feminists have theorised the state as being inherently patriarchal and their struggle has therefore often been oriented 'outside' of the state. In Finland meanwhile, the more consensus-oriented nature of welfare state development has meant that feminists have viewed the state more benignly, and have been more willing to work 'inside' its apparatus. This research investigates whether this traditional contrast between the two countries is apparent in their contemporary policy discourses. It was found that, in all four of the policy documents, men's practices are almost entirely invisible and unproblematised, and that the discourse is instead centred around the victimhood of women. The violence of men, and its underlying causes, is not engaged with, and is routinely concealed through the use of agentless language. Where men's practices are referred to, they are often degendered, through a gender-neutral discourse which obfuscates the patriarchal dynamics of domestic violence. In this representation of the problem, a deafening silence surrounds men's responsibility for domestic violence. With the focus limited only to the victims, the phenomenon is instead represented as being a problem of women, and women are thus denoted with the onus of responsibility for stopping and preventing men's violence. A fundamental transformation away from this representation of domestic violence is therefore advocated, based on the problematisation of men's practices and the gendered power relations which underpin them, as a vital part of efforts to prevent men from ever choosing to use violence in the first place. This demonstrates that there is an urgent need for further research into primary prevention work and how the norms, assumptions, and ideas which fuel men's violence can be tackled. Furthermore, confronting the practices of men means fundamentally challenging the structures of the patriarchal system, which is itself an essential step in tackling domestic violence

Development of a lattice Boltzmann model to investigate the interaction mechanism of surface acoustic wave on a sessile droplet

This study focuses on the development of a three dimensional numerical model, based on the lattice Boltzmann method (LBM), for two-phase fluid flow dynamics employing a multiple-relaxation-time (MRT) pseudopotential scheme. The numerical model is applied in the investigation of acoustic interactions with microscale sessile droplets (1- 10 µl), under surface acoustic wave (SAW) excitation, through the introduction of additonal forcing terms in the LBM scheme. In the study, a range of resonant frequencies (61.7 - 250.1 MHz) are studied and quantatively compared to existing studies and experimental findings to verify the proposed model. The modelling predictions on the roles of forces (SAW, interfacial tension, inertia and viscosity) on the dynamics of mixing, pumping and jetting of a droplet are in good agreement with observations and experimental data. Further examination of the model, through parameter study, identified that the relaxation parameters considered free to tune in the MRT, play an important role in model stability, providing large reductions in spurious velocities, in both the liquid and gas phases, when the values are specified correctly. It has also been discovered that employing a dynamic contact angle hysteresis model increased the adhesion between the liquid droplet and the substrate, improving the agreement with experimental findings by up to 20%. Lastly, an investigation of various equation of state implementations revealed some fascinating differences in droplet dynamics and behaviours, owing primarily to the physical underpinning of which each is based upon. The developed model is successfully applied in the examination of various scenarios including SAW-droplet interactions on an inclined slope, droplet impact on flat (horizontal) and inclined surfaces with and without SAW interactions, and dual SAW interactions on a droplet at several configurations. The findings indicate the importance of applied SAW power, especially in inclined slope scenarios, to overcome the inertia and gravitational forces which act to counteract the droplet motion initiated by the acoustic wave direction of travel. Furthermore, a new multi-component multi-phase multi-pseudopotential (MCMP MPI) LB model is proposed. The study details initial model development and verification for classical benchmark cases, comparing to both the single-component (SCMP MPI) and publicised data. Similar to its SCMP MPI counterpart, the model displays excellent stability, even at high density ratios, and thermodynamic consistency. Comparison to the SCMP MPI model reveals lower spurious velocities are generated in the proposed MCMP model, approximately one order of magnitude lower. Close inspection of the interaction force implementation shows they are analogous whilst similar surface tension values are presented for both models. The proposed scheme signifies a new class of MPI model capable of simulating realistic fluid compositions for use in applications of scientific and engineering interest

Proficiency testing of laboratories for paralytic shellfish poisoning toxins in shellfish by QUASIMEME: A review

AbstractParalytic Shellfish Poisoning (PSP) toxins are some of the most toxic substances known to man and consumption of shellfish containing these naturally-occurring neurotoxins can lead to a range of different symptoms including death in extreme cases. It is imperative therefore, to implement robust shellfish monitoring programs to minimise the possibility of contaminated product reaching the marketplace. To improve the quality assurance of these programs, QUASIMEME, the proficiency test provider added to its scope PSP toxins in shellfish. Since 2009, six proficiency testing exercises have been delivered by QUASIMEME with a total of thirty-four different laboratories submitting data using a range of different methods. These include animal and antibody based assays, together with High Performance Liquid Chromatography (HPLC) techniques using post and pre-column oxidation and more recently LC-MS/MS methodologies.Data from these exercises is presented and laboratory performance is assessed to determine any changes in overall performance over the six rounds, together with any potential method-related performance issues. The data showed the improvement of laboratories over the six exercises with between laboratory CV% values decreasing from an average of 39% in the first year to 22% in 2014 and the average percentage of participants receiving satisfactory z-scores increasing from 50% in 2009 to over 66% in 2014

Feedback control-based inverse kinematics solvers for a nuclear decommissioning robot

The article develops two novel feedback control-based Inverse Kinematics (IK) solvers. They are evaluated for a dual-manipulator mobile robotic system with application to nuclear decommissioning. The first algorithm has similarities to other feedback control based solvers, and borrows ideas from the Cyclic Coordinate Decent and the Jacobian Transpose methods. This yields a particularly straightforward algorithm with tunable Proportional-Integral-Derivative (PID) gains to determine performance. The second approach utilises a discrete-time state space modelling framework to solve the IK problem. Although the second solver is more complex to implement, preliminary simulation results for the case study example, show that it can converge quicker, and has improved immunity to the kinematic singularities that can occur in Jacobian based methods

Implementation of a Collaborative HIV and Hepatitis C Screening Program in Appalachian Urgent Care Settings

Introduction: With the current hepatitis C (HCV) epidemic in the Appalachian region and the risk of human immunodeficiency virus (HIV) co-infection, there is a need for increased secondary prevention efforts. The purpose of this study was to implement routine HIV and HCV screenings in the urgent care setting through the use of an electronic medical record (EMR) to increase a provider’s likelihood of testing eligible patients. Methods: From June 2017 through May 2018, EMR-based HIV and HCV screenings were implemented in three emergency department-affiliated urgent care settings: a local urgent care walk-in clinic; a university-based student health services center; and an urgent care setting located within a multi-specialty clinic. EMR best practice alerts (BPA) were developed based on Centers for Disease Control and Prevention (CDC) guidelines and populated on registered patients who qualified to receive HIV and/or HCV testing. Patients were excluded from the study if they chose to opt out from testing or the provider deemed it clinically inappropriate. Upon notification of a positive HIV and/or HCV test result through the EMR, patient navigators (PNs) were responsible for linking patients to their first medical appointment. Results: From June 2017 through May 2018, 48,531 patients presented to the three urgent care clinics. Out of 27,230 eligible patients, 1,972 patients (7.2%) agreed to be screened for HIV; for HCV, out of 6,509 eligible patients, 1,895 (29.1%) agreed to be screened. Thirty-one patients (1.6%) screened antibody-positive for HCV, with three being ribonucleic acid confirmed positives. No patients in either setting were confirmed positive for HIV; however, two initially screened HIV- positive. PNs were able to link 17 HCV antibody-positive patients (55%) to their first appointment, with the remainder having a scheduled future appointment. Conclusion: Introducing an EMR-based screening program is an effective method to identify and screen eligible patients for HIV and HCV in Appalachian urgent care settings where universal screenings are not routinely implemented. [West J Emerg Med. 2018;19(6)1057–1064.

[1,3-Bis(diphenyl­phosphino)propane-κ2 P,P′]diiodido(perfluoro­propyl)rhodium(III) dichloro­methane solvate

The structure of the title compound, [RhI2(C3F7)(C27H26P2)]·CH2Cl2, at 110 (2) K is an unusual example of a structurally characterized square-based pyramidal alkyl complex of rhodium(III). The Rh—C bond is relatively short at 1.996 (6) Å. This short metal–carbon bond length is typical of perfluoro complexes of transition metals and illustrates the enhanced bond strength in these compounds

Effects of Temperature, Growth Media, and Photoperiod on Growth and Toxin Production of Azadinium spinosum

Azaspiracids (AZAs) are microalgal toxins that can accumulate in shellfish and lead to human intoxications. To facilitate their study and subsequent biomonitoring, purification from microalgae rather than shellfish is preferable; however, challenges remain with respect to maximizing toxin yields. The impacts of temperature, growth media, and photoperiod on cell densities and toxin production in Azadinium spinosum were investigated. Final cell densities were similar at 10 and 18 ◦C, while toxin cell quotas were higher (~3.5-fold) at 10 ◦C. A comparison of culture media showed higher cell densities and AZA cell quotas (2.5–5-fold) in f10k compared to f/2 and L1 media. Photoperiod also showed differences, with lower cell densities in the 8:16 L:D treatment, while toxin cell quotas were similar for 12:12 and 8:16 L:D treatments but slightly lower for the 16:8 L:D treatment. AZA1, -2 and -33 were detected during the exponential phase, while some known and new AZAs were only detected once the stationary phase was reached. These compounds were additionally detected in field water samples during an AZA event

First Detection of Paralytic Shellfish Poisoning (PSP) Toxins in Icelandic Mussels (Mytilus edulis): Links to Causative Phytoplankton Species.

peer-reviewedParalytic shellfish poisoning (PSP) toxins were detected in blue mussels (Mytilus edulis) from two harvesting areas, Eyjafjordur on the north coast and Breidafjordur on the west coast of Iceland in 2009. During a bloom of Alexandrium spp. at both locations in June of that year, blue mussels were found to be contaminated with paralytic shellfish toxins (PSTs), leading to extensive closures of these harvesting sites. Phytoplankton data taken during this time showed the presence of large numbers of A. tamarense, with smaller numbers of A. ostenfeldii also being detected. Mussel samples were analysed by mouse bioassay (MBA) and liquid chromatography with fluorescence detection (LC-FLD). Toxicity over 10 times the European Union (EU) regulatory limit was observed in samples from Eyjafjordur while levels over 4 times this limit were detected in samples from Breidafjordur. The toxin profile determined by LC-FLD was found to be composed primarily of the carbamate toxins gonyautoxin-2,3 (GTX-2,3). Saxitoxin (STX) was also detected in all samples analysed and was the second most abundant toxin present. Gonyautoxin-1,4 (GTX-1,4) was detected at lower concentrations in half the samples analysed from both locations. Comparison is made between predicted toxin profiles from these algal species and the toxin profiles determined through LC-FLD analysis. These results represent the first identification and PST profile determination in shellfish harvested from Icelandic waters