191 research outputs found
Observational Analysis of Lyman-alpha Emission in Equivalent Magnitude Solar Flares
The chromospheric Lyman-alpha line of neutral hydrogen (Ly; 1216
\r{A}) is the most intense emission line in the solar spectrum, yet until
recently observations of flare-related Ly emission have been scarce.
Here, we examine the relationship between nonthermal electrons accelerated
during the impulsive phase of three M3 flares that were co-observed by RHESSI,
GOES, and SDO, and the corresponding response of the chromosphere in
Ly. Despite having identical X-ray magnitudes, these flares show
significantly different Ly responses. The peak Ly enhancements
above quiescent background for these flares were 1.5%, 3.3%, and 6.4%. However,
the predicted Ly enhancements from FISM2 were consistently <2.5%. By
comparing the properties of the nonthermal electrons derived from spectral
analysis of hard X-ray observations, flares with a harder spectral index were
found to produce a greater Ly enhancement. The percentage of nonthermal
energy radiated by the Ly line during the impulsive phase was found to
range from 2.0-7.9%. Comparatively, the radiative losses in He II (304 \r{A})
were found to range from 0.6-1.4% of the nonthermal energy while displaying
enhancements above the background of 7.3-10.8%. FISM2 was also found to
underestimate the level of He II emission in two out of the three flares. These
results may have implications for space weather studies and modelling the
response of the terrestrial atmosphere to changes in the solar irradiance, and
will guide the interpretation of flare-related Ly observations that
will become available during Solar Cycle 25
The landscape, heritage and society of St Michael's churchyard, Shotwick
This dissertation examines the history and heritage of St Michael's Churchyard in the Wirral parish of Shotwick. It explores in particular the effect topographical features and historical events have had on the churchyard's development. Stylistic variations in memorials are analysed to identify chronological trends. The lifestyle of churchyard occupants is also discussed, with the spotlight focusing specifically on the Whaley, Roberts and Maddock families; parish curates; and RAF pilots killed in the final months of the Second World War. Information has chiefly been derived from memorials recorded during numerous visits to the churchyard itself, and from primary and secondary sources held by Cheshire and Chester Archives and Local Studies, in particular maps, parish registers and their transcripts, churchwarden's accounts, wills, reports of coroner's inquests, school log¬books, tithe apportionments, charters and church correspondence. Relevant information has been extracted from Cheshire County Council's Sites and Monuments Record, and material held by the War Graves Commission and the RAF Museum at Hendon has also contributed to the exposition. Data from all these sources has been collated and analysed to extrapolate parochial trends, and much supporting material discussed in the body of the dissertation is included in the Appendices as verification
Research for the development of software techniques for computer-driven displays
Graphical data structures by display transformation routines to compute
Survival of Influenza A(H1N1) on Materials Found in Households: Implications for Infection Control
The majority of influenza transmission occurs in homes, schools and workplaces, where many frequently touched communal items are situated. However the importance of transmission via fomites is unclear since few data exist on the survival of virus on commonly touched surfaces. We therefore measured the viability over time of two H1N1 influenza strains applied to a variety of materials commonly found in households and workplaces.Influenza A/PuertoRico/8/34 (PR8) or A/Cambridge/AHO4/2009 (pandemic H1N1) viruses were inoculated onto a wide range of surfaces used in home and work environments, then sampled at set times following incubation at stabilised temperature and humidity. Virus genome was measured by RT-PCR; plaque assay (for PR8) or fluorescent focus formation (for pandemic H1N1) was used to assess the survival of viable virus.The genome of either virus could be detected on most surfaces 24 h after application with relatively little drop in copy number, with the exception of unsealed wood surfaces. In contrast, virus viability dropped much more rapidly. Live virus was recovered from most surfaces tested four hours after application and from some non-porous materials after nine hours, but had fallen below the level of detection from all surfaces at 24 h. We conclude that influenza A transmission via fomites is possible but unlikely to occur for long periods after surface contamination (unless re-inoculation occurs). In situations involving a high probability of influenza transmission, our data suggest a hierarchy of priorities for surface decontamination in the multi-surface environments of home and hospitals
Skeletal muscle NOX4 is required for adaptive responses that prevent insulin resistance
Reactive oxygen species (ROS) generated during exercise are considered integral for the health-promoting effects of exercise. However, the precise mechanisms by which exercise and ROS promote metabolic health remain unclear. Here, we demonstrate that skeletal muscle NADPH oxidase 4 (NOX4), which is induced after exercise, facilitates ROS-mediated adaptive responses that promote muscle function, maintain redox balance, and prevent the development of insulin resistance. Conversely, reductions in skeletal muscle NOX4 in aging and obesity contribute to the development of insulin resistance. NOX4 deletion in skeletal muscle compromised exercise capacity and antioxidant defense and promoted oxidative stress and insulin resistance in aging and obesity. The abrogated adaptive mechanisms, oxidative stress, and insulin resistance could be corrected by deleting the H2O2-detoxifying enzyme GPX-1 or by treating mice with an agonist of NFE2L2, the master regulator of antioxidant defense. These findings causally link NOX4-derived ROS in skeletal muscle with adaptive responses that promote muscle function and insulin sensitivity
An exploration of the use of simple statistics to measure consensus and stability in Delphi studies
<p>Abstract</p> <p>Background</p> <p>The criteria for stopping Delphi studies are often subjective. This study aimed to examine whether consensus and stability in the Delphi process can be ascertained by descriptive evaluation of trends in participants' views.</p> <p>Methods</p> <p>A three round email-based Delphi required participants (n = 12) to verify their level of agreement with 8 statements, write comments on each if they considered it necessary and rank the statements for importance. Each statement was analysed quantitatively by the percentage of agreement ratings, importance rankings and the amount of comments made for each statement, and qualitatively using thematic analysis. Importance rankings between rounds were compared by calculating Kappa values to observe trends in how the process impacts on subject's views.</p> <p>Results</p> <p>Evolution of consensus was shown by increase in agreement percentages, convergence of range with standard deviations of importance ratings, and a decrease in the number of comments made. Stability was demonstrated by a trend of increasing Kappa values.</p> <p>Conclusion</p> <p>Following the original use of Delphi in social sciences, Delphi is suggested to be an effective way to gain and measure group consensus in healthcare. However, the proposed analytical process should be followed to ensure maximum validity of results in Delphi methodology for improved evidence of consensual decision-making.</p
Impaired RNA incorporation and dimerization in live attenuated leader-variants of SIV(mac239)
BACKGROUND: The 5' untranslated region (UTR) or leader sequence of simian immunodeficiency virus (SIV(mac239)) is multifunctional and harbors the regulatory elements for viral replication, persistence, gene translation, expression, and the packaging and dimerization of viral genomic RNA (vRNA). We have constructed a series of deletions in the SIV(mac239 )leader sequence in order to determine the involvement of this region in both the packaging and dimerization of viral genomic RNA. We also assessed the impact of these deletions upon viral infectiousness, replication kinetics and gene expression in cell lines and monkey peripheral blood mononuclear cells (PBMC). RESULTS: Regions on both sides of the major splice donor (SD) were found to be necessary for the efficiency and specificity of viral genome packaging. However, stem-loop1 is critical for both RNA encapsidation and dimerization. Downstream elements between the splice donor and the initiation site of SIV-Gag have additive effects on RNA packaging and contribute to a lesser degree to RNA dimerization. The targeted disruption of structures on both sides of the SD also severely impacts viral infectiousness, gene expression and replication in both CEMx174 cells and rhesus PBMC. CONCLUSION: In the leader region of SIV(mac239), stem-loop1 functions as the primary determinant for both RNA encapsidation and dimerization. Downstream elements between the splice donor and the translational initiation site of SIV-Gag are classified as secondary determinants and play a role in dimerization. Collectively, these data signify a linkage between the primary encapsidation determinant of SIV(mac239 )and RNA dimerization
- …