687 research outputs found
Generation and delivery of free hydroxyl radicals using a remote plasma
We demonstrate a new gas-based generation source using a low power radio frequency driven atmospheric pressure plasma configured to deliver the radical flux into the far effluent region, well away from interference from other plasma factors such as electric fields, currents, and ultraviolet radiation. Using He–H2O gas chemistry isolated from the laboratory air, the plasma generated flux contains and other radicals including, O and HO2 as well as H2O2 which, along with, was found to vary with H2O vapour content and absorbed power density. Peak flux values were 2.3 nmol s−1 and 0.23 nmol s1 for H2O2 and respectively at a distance of 50 mm from the plasma, with 790 ppmv H2O and a power density of ∼108 W m−3. The maximum flux density was 4.5 × 1019 m−2s−1 falling to 1.7 × 1019 m2 s1 at 110 mm, equivalent to generation rates of 74 µM s1 and 28 µM s−1. Despite high recombination rates at the plasma exit, the escaping flux is still significant, indicating a viable delivery capability to downstream targets. Its performance with regard to generation rates compares well with traditional generation techniques such as radiolysis, advanced oxidation processes and enhanced Fenton-chemistry approaches where production rates are sub-µM s−1. Delivering precisely quantifiable fluxes provides new opportunities for scientific studies and technological opportunities in cell biology, atmospheric chemistry, protein unfolding and systematic dose studies for plasma-based and other related potential medical treatments
Concentration of atomic hydrogen diffused into silicon in the temperature range 900–1300 °C
Boron-doped Czochralski silicon samples with [B]~1017 cm−3 have been heated at various temperatures in the range 800–1300 °C in an atmosphere of hydrogen and then quenched. The concentration of [H-B] pairs was measured by infrared localized vibrational mode spectroscopy. It was concluded that the solubility of atomic hydrogen is greater than [Hs] = 5.6 × 1018 exp( − 0.95 eV/kT)cm−3 at the temperatures investigated
The longitudinal, bidirectional relationships between parent reports of child secondhand smoke exposure and child smoking trajectories
This study examines the longitudinal relationships between child smoking and secondhand smoke exposure (SHSe). Participants were 222 parent–child dyads. The parents smoked, had a child with (48%) or without asthma, and were enrolled in a smoking/health intervention. Parent-reported child SHSe was measured at baseline and 4, 6, and 12-month follow-ups; self-reported child smoking was assessed at these points and at 2-months. A parallel process growth model was used. Baseline child SHSe and smoking were correlated (r = 0.30). Changes in child SHSe and child smoking moved in tandem as evidenced by a correlation between the linear slopes of child smoking and SHSe (r = 0.32), and a correlation between the linear slope of child smoking and the quadratic slope of child SHSe (r = − 0.44). Results may inform interventions with the potential to reduce child SHSe and smoking among children at increased risk due to their exposure to parental smoking.</p
The role of science in physical natural hazard assessment : report to the UK Government by the Natural Hazard Working Group
Following the tragic Asian tsunami on 26 December 2004, the Prime Minister asked
the Government’s Chief Scientific Adviser, Sir David King, to convene a group of
experts (the Natural Hazard Working Group) to advise on the mechanisms that could
and should be established for the detection and early warning of global physical
natural hazards.
2. The Group was asked to examine physical hazards which have high global or regional
impact and for which an appropriate early warning system could be put in place. It
was also asked to consider the global natural hazard frameworks currently in place
and under development and their effectiveness in using scientific evidence; to
consider whether there is an existing appropriate international body to pull together
the international science community to advise governments on the systems that need
to be put in place, and to advise on research needed to fill current gaps in knowledge.
The Group was asked to make recommendations on whether a new body was
needed, or whether other arrangements would be more effective
Lagrangian dust model simulations for a case of moist convective dust emission and transport in the western Sahara region during Fennec/LADUNEX
Biallelic GINS2 variant p.(Arg114Leu) causes Meier-Gorlin syndrome with craniosynostosis
Contains fulltext :
284813.pdf (Publisher’s version ) (Open Access)INTRODUCTION: Replication of the nuclear genome is an essential step for cell division. Pathogenic variants in genes coding for highly conserved components of the DNA replication machinery cause Meier-Gorlin syndrome (MGORS). OBJECTIVE: Identification of novel genes associated with MGORS. METHODS: Exome sequencing was performed to investigate the genotype of an individual presenting with prenatal and postnatal growth restriction, a craniofacial gestalt of MGORS and coronal craniosynostosis. The analysis of the candidate variants employed bioinformatic tools, in silico structural protein analysis and modelling in budding yeast. RESULTS: A novel homozygous missense variant NM_016095.2:c.341G>T, p.(Arg114Leu), in GINS2 was identified. Both non-consanguineous healthy parents carried this variant. Bioinformatic analysis supports its classification as pathogenic. Functional analyses using yeast showed that this variant increases sensitivity to nicotinamide, a compound that interferes with DNA replication processes. The phylogenetically highly conserved residue p.Arg114 localises at the docking site of CDC45 and MCM5 at GINS2. Moreover, the missense change possibly disrupts the effective interaction between the GINS complex and CDC45, which is necessary for the CMG helicase complex (Cdc45/MCM2-7/GINS) to accurately operate. Interestingly, our patient's phenotype is strikingly similar to the phenotype of patients with CDC45-related MGORS, particularly those with craniosynostosis, mild short stature and patellar hypoplasia. CONCLUSION: GINS2 is a new disease-associated gene, expanding the genetic aetiology of MGORS
A standardised ecosystem services framework for the deep sea
Despite its remoteness, human activity has impacted the deep sea and changes to the structure and function of deep-sea ecosystems are already noticeable. In terrestrial and shallow water marine environments, demonstrating how ecosystems support human well-being has been instrumental in setting policy and management objectives for sustainable resource use. Foundational to this approach is a framework of ecosystem service (ES) classification and a synthesis of the knowledge base, which can then be used to structure decision-support tools such as ecosystem accounts or Environmental Impact Assessments. At present, no such framework exists for the deep sea. There is thus an urgent need to determine and assess the ES provided by deep-sea habitats and species before (potentially irreversible) decisions are made about deep-sea habitat use and governance. As a first step towards the incorporation of ES in such decision-making, we undertake two systematic reviews of the scientific literature based on the principles of the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) systematic process. This was to define a comparative ES framework and synthesise the current evidence base for how deep-sea habitats support ecosystem services. Our framework proposes four supporting services, three regulating services, four provisioning services and three cultural services for which there is an established and growing body of evidence for the role of deep-sea habitats. The ES framework presented here provides a structure for deep-sea ecosystem services. In its next phase of development, this could provide the foundation for the development of habitat-ecosystem service matrices, which are a critical component for truly accounting for ES in decision-making, particularly spatial management. This framework has significant implications for deep-sea management, conservation and policy, as it provides an ecosystem services-based tool that can be used in any deep-sea ecosystems management across the planet, and it also shows how critical these data gaps are for today’s decisions and how seriously they should be considered in decision-making processes
Spatial and temporal variability in recruitment of intertidal mussels around the coast of southern Africa
Intensity of intertidal mussel recruitment was compared across a range of different spatial and temporal scales around the coast of southern Africa between June 1995 and October 1996. Comparison of the east and west coasts revealed significantly higher recruit densities on the west coast, corresponding to larger adult densities. This difference between the two coasts reflects biogeographic disparities in mussel species composition, growth rates and spawning intensities, oceanographic conditions and productivity. Significant spatial variations in recruitment were recorded between regions 100–1000 km apart and between localities 1–25 km apart. Results suggest that the influence of dispersal processes on recruitment patterns acts at a relatively small scale, and may affect the distribution and abundance of adults among shores only a few kilometres apart. The high variability in recruitment intensities at a scale of metres indicates that larva! supply to the shore may be locally patchy, or that settlement preferences of recruits may be sensitive to subtle small-scale differences in adult density within mussel clumps. Small-scale differences in post-settlement mortality (e.g. owing to patchy predation pressure) may also play a role. This small-scale variability in recruitment is likely to reinforce the mosaic distribution of mussels evident on many of the shores. Significant temporal variability in recruit density was recorded, both between 3-monthly sampling intervals and interannually. Seasonal differences were absent for the north-west regions, whereas asynchronous seasonal patterns were displayed in the other regions. Results suggest that temporal cycles of recruitment are irregular and episodic, which may have important consequences for the dynamics of adults. Significant positive correlations were obtained between maximal recruitment and adult abundance, measured by density, or total number of adults on the shore (stock). This could be explained by the density-dependent role of adult conspecifics in providing suitable settlement habitat, or supply-side recruit limitation. These results have important implications for the management of exploited populations of mussels around the coast of southern Africa. Exploitation may influence recruitment success via at least two processes: reduction of larval supply by depletion of adult stock, and alteration of habitat suitable for settlement. Thus, overexploitation will compromise recruitment, which is itself the only mechanism of recovery. The west-coast mussel populations are likely to be more resilient to exploitation as recruitment is more predictable over time, stocks are larger and recruitment intensities high. This brings into question the present regulations for mussel harvesting because, paradoxically, more lenient regulations are applied on the east coast, where stocks and recruitment are low, than on the west coast, where biomass, recruitment and potential for recovery are high
Severe COVID anxiety among adults in the United Kingdom: cohort study and nested feasibility trial
BACKGROUND: People with severe COVID anxiety have poor mental health and impaired functioning, but the course of severe COVID anxiety is unknown and the quality of evidence on the acceptability and impact of psychological interventions is low. METHODS: People with severe COVID anxiety have poor mental health and impaired functioning, but the course of severe COVID anxiety is unknown and the quality of evidence on the acceptability and impact of psychological interventions is low. RESULTS: 204 (70.2%) of 285 people who took part in the cohort study completed the six month follow-up, for whom levels of COVID anxiety fell from 12.4 at baseline to 6.8 at six months (difference = -5.5, 95% CI = -6.0 to -4.9). Reductions in COVID anxiety were lower among older people, those living with a vulnerable person, those with lower baseline COVID anxiety, and those with higher levels of generalised anxiety and health anxiety at baseline. 36 (90%) of 40 participants enrolled in the nested feasibility trial were followed up at six months. 17 (80.9%) of 21 people in the active arm of the trial received four or more sessions of CBT-HA. We found improved mental health and social functioning among those in the active, but not the control arm of the trial (Mean difference in total score on the Work and Social Adjustment Scale between baseline and follow up, was 9.7 (95% CI = 5.8–13.6) among those in the active, and 1.0 (95% C.I. = -4.6 to 6.6) among those in the control arm of the trial. CONCLUSIONS: While the mental health of people with severe COVID anxiety appears to improve over time, many continue to experience high levels of anxiety and poor social functioning. Health anxiety is highly prevalent among people with severe COVID anxiety and may provide a target for psychological treatment. TRIAL REGISTRATION: Retrospectively registered at ISRCTN14973494 on 09/09/2021
Designer diatom episomes delivered by bacterial conjugation.
Eukaryotic microalgae hold great promise for the bioproduction of fuels and higher value chemicals. However, compared with model genetic organisms such as Escherichia coli and Saccharomyces cerevisiae, characterization of the complex biology and biochemistry of algae and strain improvement has been hampered by the inefficient genetic tools. To date, many algal species are transformable only via particle bombardment, and the introduced DNA is integrated randomly into the nuclear genome. Here we describe the first nuclear episomal vector for diatoms and a plasmid delivery method via conjugation from Escherichia coli to the diatoms Phaeodactylum tricornutum and Thalassiosira pseudonana. We identify a yeast-derived sequence that enables stable episome replication in these diatoms even in the absence of antibiotic selection and show that episomes are maintained as closed circles at copy number equivalent to native chromosomes. This highly efficient genetic system facilitates high-throughput functional characterization of algal genes and accelerates molecular phytoplankton research
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