59 research outputs found
Acid episodes and the behavioural ecology of Atlantic salmon Salmo salar L
Although the impacts of surface water acidification on Atlantic salmon (Salmo salar L.) and brown trout (Salmo trutta L.) are well described, factors affecting recovery following pollution abatement are poorly understood. Paradoxically, despite increasing average pH over the last two decades, stocking efforts to rehabilitate damaged populations have not been successful. One possible explanation is that average pH measurements mask the effects of episodic fluctuations during high flow when pH is transiently reduced, metal concentrations are elevated and some organisms are affected adversely. However, because salmonid fish (i) avoid acid water and (ii) shelter within stream bed interstices, assessing the effects of acid episodes on their populations requires some understanding of how refuge use, refuge availability and refuge conditions affect recolonisation opportunities. This project therefore examined the effects of acid episodes on the behaviour of Atlantic salmon at different life stages as a possible explanation for the limited recovery of re-stocked populations. Sampling in acid sensitive-streams at low and high (episodic) flow revealed that the stream hyporheos was less acid than surface water in the same streams, with temperature and conductivity also more favourable in interstices. Laboratory experiments were then used to examine (i) the behaviour of Atlantic salmon alevins during a simulated episode in a vertical substrate-filled tank (Chapter 3) (ii) the behaviour of Atlantic salmon parr during a simulated episode in a shelter choice tank (Chapter 4) and (iii) if differences resulting from rearing environment affected the behaviour of Atlantic salmon parr during a simulated acid episode (Chapter 5). Hatchery-reared alevins avoided episodically acid conditions by moving into an area of more neutral pH opercular rate and mortality were both greater in acid water. Hatchery-reared pan- preferentially used a neutral shelter acid exposure also resulted in increased activity and opercular rate. Fish reared in a simulated wild environment were better able to avoid acid pulses (i.e. they showed greater use of neutral refuges) than hatchery-reared fish, but other behavioural responses (activity and opercular rate) were similar. These results illustrate the potential importance of the streambed during acid episodes as chemical refuges to salmonids, which both alevins and parr are able to exploit. However, at least for hatchery-reared fish, the success of re-stocking programmes could be improved by subjecting fish to acid stress- conditioning regimes prior to release
The 2010 August 01 type II burst: A CME-CME Interaction, and its radio and white-light manifestations
We present observational results of a type II burst associated with a CME-CME
interaction observed in the radio and white-light wavelength range. We applied
radio direction-finding techniques to observations from the STEREO and Wind
spacecraft, the results of which were interpreted using white-light
coronagraphic measurements for context. The results of the multiple
radio-direction finding techniques applied were found to be consistent both
with each other and with those derived from the white-light observations of
coronal mass ejections (CMEs). The results suggest that the Type II burst radio
emission is causally related to the CMEs interaction.Comment: 7 pages, 6 figures, Accepted to ApJ: January 16, 201
Abundance of a chlorophyll a precursor and the oxidation product hydroxychlorophyll a during seasonal phytoplankton community progression in the Western English Channel
This study presents the first in-situ measurements of the chlorophyll a oxidation product, hydroxychlorophyll a as well as the chlorophyll a precursor, chlorophyll aP276 conducted over an annual cycle. Chlorophyll a oxidation products, such as hydroxychlorophyll a may be associated with the decline of algal populations and can act as an initial step in the degradation of chlorophyll a into products which can be found in the geochemical record, important for studying past climate change events. Here, hydroxychlorophyll a and chlorophyll aP276 were measured at the long-term monitoring station L4, Western Channel Observatory (UK, www.westernchannelobservatory.org) over an annual cycle (2012). Weekly measurements of phytoplankton species composition and abundance enabled detailed analysis of possible sources of hydroxychlorophyll a. Dinoflagellates, 2 diatom species, the prymnesiophyte Phaeocystis spp. and the coccolithophorid Emiliania huxleyi were all associated with hydroxychlorophyll a occurrence. However, during alternate peaks in abundance of the diatoms, no association with hydroxychlorophyll a occurred, indicating that the oxidation of chlorophyll a was dependant not only on species but also on additional factors such as the mode of mortality, growth limiting factor (i.e. nutrient concentration) or phenotypic plasticity. Surface sediment samples contained 10 times more hydroxychlorophyll a (relative to chlorophyll a) than pelagic particulate samples, indicating that more chlorophyll a oxidation occurred during sedimentation or at the sediment-water interface, than in the pelagic environment. In addition, chlorophyll aP276 correlated with chl-a concentration, thus supporting its assignment as a chl-a precursor
Annealing multicomponent supramolecular gels
Annealing is widely used as a means of changing the physical properties of a material. The rate of heating
and cooling used in the annealing process controls the final properties. Annealing can be used as a means
of driving towards the, or at least a, thermodynamic minimum. There is surprisingly little information on
annealing kinetically-trapped supramolecular gels. Here, we show that annealing multicomponent gels can
be used to prepare materials with tunable mechanical properties. We show that annealing in a two-component
gel leads to a self-sorted network, which has significantly different mechanical properties to the asprepared
gels. Whilst the fibres are self-sorted, we show that the annealing of this system leads to significant
change in the network level of assembly, and it is this that leads to the increase in storage modulus. We also
show that it is possible to selectively anneal only a single component in the mixtureAMFC thanks the University of Glasgow for funding. FPGF
acknowledges an Erasmus traineeship. DJA thanks the EPSRC
for a Fellowship (EP/L021978/1), which funded BD.
MarvinSketch 16.11.28.0 was used for naming chemical structures.
This work benefitted from SasView software, originally
developed by the DANSE project under NSF award
DMR-0520547. SasView also contains code developed with
funding from the EU Horizon 2020 programme under the
SINE2020 project Grant No. 654000. The X-ray scattering
apparatus was purchased under (EP/K035746/1)
Using a Human Challenge Model of Infection to Measure Vaccine Efficacy: A Randomised, Controlled Trial Comparing the Typhoid Vaccines M01ZH09 with Placebo and Ty21a
Background
Typhoid persists as a major cause of global morbidity. While several licensed vaccines to prevent typhoid are available, they are of only moderate efficacy and unsuitable for use in children less than two years of age. Development of new efficacious vaccines is complicated by the human host-restriction of Salmonella enterica serovar Typhi (S. Typhi) and lack of clear correlates of protection. In this study, we aimed to evaluate the protective efficacy of a single dose of the oral vaccine candidate, M01ZH09, in susceptible volunteers by direct typhoid challenge.
Methods and Findings
We performed a randomised, double-blind, placebo-controlled trial in healthy adult participants at a single centre in Oxford (UK). Participants were allocated to receive one dose of double-blinded M01ZH09 or placebo or 3-doses of open-label Ty21a. Twenty-eight days after vaccination, participants were challenged with 104CFU S. Typhi Quailes strain. The efficacy of M01ZH09 compared with placebo (primary outcome) was assessed as the percentage of participants reaching pre-defined endpoints constituting typhoid diagnosis (fever and/or bacteraemia) during the 14 days after challenge. Ninety-nine participants were randomised to receive M01ZH09 (n = 33), placebo (n = 33) or 3-doses of Ty21a (n = 33). After challenge, typhoid was diagnosed in 18/31 (58.1% [95% CI 39.1 to 75.5]) M01ZH09, 20/30 (66.7% [47.2 to 87.2]) placebo, and 13/30 (43.3% [25.5 to 62.6]) Ty21a vaccine recipients. Vaccine efficacy (VE) for one dose of M01ZH09 was 13% [95% CI -29 to 41] and 35% [-5 to 60] for 3-doses of Ty21a. Retrospective multivariable analyses demonstrated that pre-existing anti-Vi antibody significantly reduced susceptibility to infection after challenge; a 1 log increase in anti-Vi IgG resulting in a 71% decrease in the hazard ratio of typhoid diagnosis ([95% CI 30 to 88%], p = 0.006) during the 14 day challenge period. Limitations to the study included the requirement to limit the challenge period prior to treatment to 2 weeks, the intensity of the study procedures and the high challenge dose used resulting in a stringent model.
Conclusions
Despite successfully demonstrating the use of a human challenge study to directly evaluate vaccine efficacy, a single-dose M01ZH09 failed to demonstrate significant protection after challenge with virulent Salmonella Typhi in this model. Anti-Vi antibody detected prior to vaccination played a major role in outcome after challenge
The OdonAssist inflatable device for assisted vaginal birth—the ASSIST II study (United Kingdom)
BackgroundDecreasing rates of assisted vaginal birth have been paralleled with increasing rates of cesarean deliveries over the last 40 years. The OdonAssist is a novel device for assisted vaginal birth. Iterative changes to clinical parameters, device design, and technique have been made to improve device efficacy and usability.ObjectiveThis study aimed to determine if the feasibility, safety, and efficacy of the OdonAssist device were sufficient to justify conducting a future randomized controlled trial.Study DesignAn open-label nonrandomized study of 104 participants having a clinically indicated assisted vaginal birth using the OdonAssist was undertaken at Southmead Hospital, Bristol, United Kingdom. Data were also collected from participants who consented to participate in the study but for whom trained OdonAssist operators were not available, providing a nested cohort. The primary clinical outcome was the proportion of births successfully expedited with the OdonAssist. Secondary outcomes included clinical, patient-reported, operator-reported, device and health care utilization. Neonatal outcome data were reviewed at day 28, and maternal outcomes were investigated up to day 90. Given that the number of successful OdonAssist births was ≥61 out of 104, the hypothesis of a poor rate of 50% was rejected in favor of a good rate of ≥65%.ResultsBetween August 2019 and June 2021, 941 (64%) of the 1471 approached, eligible participants consented to participate. Of these, 104 received the OdonAssist intervention. Birth was assisted in all cephalic vertex fetal positions, at all stations ≥1 cm below the ischial spines (with or without regional analgesia). The OdonAssist was effective in 69 of the 104 (66%) cases, consistent with the hypothesis of a good efficacy rate. There were no serious device-related maternal or neonatal adverse reactions, and there were no serious adverse device effects. Only 4% of neonatal soft tissue bruising in the successful OdonAssist group was considered device-related, as opposed to 20% and 23% in the unsuccessful OdonAssist group and the nested cohort, respectively. Participants reported high birth perception scores. All practitioners found the device use to be straightforward.ConclusionRecruitment to an interventional study of a new device for assisted vaginal birth is feasible; 64% of eligible participants were willing to participate. The success rate of the OdonAssist was comparable to that of the Kiwi OmniCup when introduced in the same unit in 2002, meeting the threshold for a randomized controlled trial to compare the OdonAssist with current standard practice. There were no disadvantages of study participation in terms of maternal and neonatal outcomes. There were potential advantages of using the OdonAssist, particularly reduced neonatal soft tissue injury. The same application technique is used for all fetal positions, with all operators deeming the device straightforward to use. This study provides important data to inform future study design
Leaving the Minors : The Green Party of Aotearoa New Zealand and the 2011 General Election
The Green Party of Aotearoa New Zealand has emerged as a successful environmentally focused party with a solid base. The 2011 General Election represented a high-point for the party, distancing it from the other minor parties. This article explores examples of factors affecting the success of Green parties, and examines the strategy of the New Zealand Green Party prior to the 2011 election. The findings indicate that the party has developed stable support through the development of a consistent policy base and pragmatic approach to its role in parliament. This has allowed the Greens to establish a position following the 2011 election as the third party in New Zealand politics
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Digital Remote Monitoring Using an mHealth Solution for Survivors of Cancer: Protocol for a Pilot Observational Study
Background: Healthy lifestyle interventions have a positive impact on multiple disease trajectories, including cancer-related outcomes. Specifically, appropriate habitual physical activity, adequate sleep, and a regular wholesome diet are of paramount importance for the wellness and supportive care of survivors of cancer. Mobile health (mHealth) apps have the potential to support novel tailored lifestyle interventions.
Objective: This observational pilot study aims to assess the feasibility of mHealth multidimensional longitudinal monitoring in survivors of cancer. The primary objective is to test the compliance (user engagement) with the monitoring solution. Secondary objectives include recording clinically relevant subjective and objective measures collected through the digital solution.
Methods: This is a monocentric pilot study taking place in Bangor, Wales, United Kingdom. We plan to enroll up to 100 adult survivors of cancer not receiving toxic anticancer treatment, who will provide self-reported behavioral data recorded via a dedicated app and validated questionnaires and objective data automatically collected by a paired smartwatch over 16 weeks. The participants will continue with their normal routine surveillance care for their cancer. The primary end point is feasibility (eg, mHealth monitoring acceptability). Composite secondary end points include clinically relevant patient-reported outcome measures (eg, the Edmonton Symptom Assessment System score) and objective physiological measures (eg, step counts). This trial received a favorable ethical review in May 2023 (Integrated Research Application System 301068).
Results: This study is part of an array of pilots within a European Union funded project, entitled “GATEKEEPER,” conducted at different sites across Europe and covering various chronic diseases. Study accrual is anticipated to commence in January 2024 and continue until June 2024. It is hypothesized that mHealth monitoring will be feasible in survivors of cancer; specifically, at least 50% (50/100) of the participants will engage with the app at least once a week in 8 of the 16 study weeks.
Conclusions: In a population with potentially complex clinical needs, this pilot study will test the feasibility of multidimensional remote monitoring of patient-reported outcomes and physiological parameters. Satisfactory compliance with the use of the app and smartwatch, whether confirmed or infirmed through this study, will be propaedeutic to the development of innovative mHealth interventions in survivors of cancer
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