3,963 research outputs found
XCDCC: Core Excitation in the Breakup of Exotic Nuclei
The eXtended Continuum Discretized Coupled Channel (XCDCC) method is
developed to treat reactions where core degrees of freedom play a role. The
projectile is treated as a multi-configuration coupled channels system
generated from a valence particle coupled to a deformed core which is allowed
to excite. The coupled channels initial state breaks up into a coupled channels
continuum which is discretized into bins, similarly to the original CDCC
method. Core collective degrees of freedom are also included in the interaction
of the core and the target, so that dynamical effects can occur during the
reaction. We present results for the breakup of C=C+n and
Be=Be+n on Be. Results show that the total cross section
increases with core deformation. More importantly, the relative percentage of
the various components of the initial state are modified during the reaction
process through dynamical effects. This implies that comparing spectroscopic
factors from structure calculations with experimental cross sections requires
more detailed reaction models that go beyond the single particle model.Comment: 14 pages, revtex, submitted to Phys Rev
Preparing for Doris: Exploring Public Responses to Impact-Based Weather Warnings in the United Kingdom
In the UK, the Met Office issues regionally calibrated impact-based weather warnings. These aim to reduce harm to people and property. To decrease risk from severe weather, it is important to understand how members of the UK public interpret and act on these warnings. This paper addresses this through a post-event survey (n=552) conducted following Storm Doris, a 2017 winter storm during which wind warnings were issued across much of the UK. Survey questions examined 1) understanding of impact-based wind warnings; 2) interpretation of local warning level; 3) predictors of perceived local risk (likelihood, impact severity, concern) implied by warnings; 4) predictors of trust in the forecast; and 5) predictors of recalled and anticipated action. Our findings indicate that UK residents generally understand that weather warnings are based on potential weather impacts, although many do not realize warnings are regionally calibrated. We also find that while local warning levels are rarely underestimated, they may sometimes be overestimated. Institutional trust in the Met Office and perceived vulnerability to weather predict both perceived risk and behavioral response, while warning “understandability” is linked to greater trust in the forecast. Strikingly, while differences in local warning levels influenced risk perception, they did not affect recalled or intended behavioral response. This study highlights the importance of institutional trust in the effective communication of severe weather warnings, and a need for education on impact-based weather warnings. Above all, it demonstrates the need for further exploration of the effect of weather warnings on protective behavior
Effect of temperature-dependent air properties on the accuracy of numerical simulations of thermal airflows over pinned heat sinks
The importance of accounting for the temperature dependence of air properties in numerical simulations of air flows over pinned heat sinks is demonstrated by comparisons with recently published experiments. Numerical simulations, based on a conjugate heat transfer analysis, using the RANS-based modified k-ω turbulence model, with temperature-dependent air properties, are shown to be in significantly better agreement with experimental measurements of pressure drop, heat transfer coefficient, and heat sink base temperature, than those which employ constant air properties
Non-adiabatic corrections to elastic scattering of halo nuclei
We derive the formalism for the leading order corrections to the adiabatic
approximation to the scattering of composite projectiles. Assuming a two-body
projectile of core plus loosely-bound valence particle and a model (the core
recoil model) in which the interaction of the valence particle and the target
can be neglected, we derive the non-adiabatic correction terms both exactly,
using a partial wave analysis, and using the eikonal approximation. Along with
the expected energy dependence of the corrections, there is also a strong
dependence on the valence-to-core mass ratio and on the strength of the
imaginary potential for the core-target interaction, which relates to
absorption of the core in its scattering by the target. The strength and
diffuseness of the core-target potential also determine the size of the
corrections. The first order non-adiabatic corrections were found to be smaller
than qualitative estimates would expect. The large absorption associated with
the core-target interaction in such halo nuclei as Be11 kills off most of the
non-adiabatic corrections. We give an improved estimate for the range of
validity of the adiabatic approximation when the valence-target interaction is
neglected, which includes the effect of core absorption. Some consideration was
given to the validity of the eikonal approximation in our calculations.Comment: 14 pages with 10 figures, REVTeX4, AMS-LaTeX v2.13, submitted to
Phys. Rev.
Advice for Health Care Professionals and Users: An Evaluation of Websites for Perinatal Anxiety
Background: Many websites are available with information and resources for perinatal anxiety; however, there is limited research on the quality and content of these sites.
Objective: This study aims to identify what sites are available on perinatal anxiety, identify any information and therapeutic advice given, and review its accuracy and website design.
Methods: We conducted an evaluation of websites for perinatal anxiety. Eligible websites (N=50) were evaluated for accuracy of information, resources for mothers, website quality, and readability.
Results: Information was often incomplete and focused on symptoms rather than risk factors or impact of untreated perinatal anxiety. Websites often had information on treatment (46/50, 92%), but much less on screening (19/50, 38%). Most sites provided at least some resources to support mothers (49/50, 98%), but active, guided support was infrequent (25/50, 50%). Website quality was extremely variable and mostly difficult to read (42/50, 84%).
Conclusions: This study recommends the top 4 websites on perinatal anxiety for health care professionals and users. There is a need for websites to be developed that provide accurate, evidence-based information that women can relate to with quality support resources. Furthermore, these sites should be easy to use and readable
Comparison of Outcomes in Level I vs Level II Trauma Centers in Patients Undergoing Craniotomy or Craniectomy for Severe Traumatic Brain Injury.
BACKGROUND: Traumatic brain injury (TBI) carries a devastatingly high rate of morbidity and mortality.
OBJECTIVE: To assess whether patients undergoing craniotomy/craniectomy for severe TBI fare better at level I than level II trauma centers in a mature trauma system.
METHODS: The data were extracted from the Pennsylvania Trauma Outcome Study database. Inclusion criteria were patients \u3e 18 yr with severe TBI (Glasgow Coma Scale [GCS] score less than 9) undergoing craniotomy or craniectomy in the state of Pennsylvania from January 1, 2002 through September 30, 2017.
RESULTS: Of 3980 patients, 2568 (64.5%) were treated at level I trauma centers and 1412 (35.5%) at level II centers. Baseline characteristics were similar between the 2 groups except for significantly worse GCS scores at admission in level I centers (P = .002). The rate of in-hospital mortality was 37.6% in level I centers vs 40.4% in level II centers (P = .08). Mean Functional Independence Measure (FIM) scores at discharge were significantly higher in level I (10.9 ± 5.5) than level II centers (9.8 ± 5.3; P \u3c .005). In multivariate analysis, treatment at level II trauma centers was significantly associated with in-hospital mortality (odds ratio, 1.2; 95% confidence interval, 1.03-1.37; P = .01) and worse FIM scores (odds ratio, 1.4; 95% confidence interval, 1.1-1.7; P = .001). Mean hospital and ICU length of stay were significantly longer in level I centers (P \u3c .005).
CONCLUSION: This study showed superior functional outcomes and lower mortality rates in patients undergoing a neurosurgical procedure for severe TBI in level I trauma centers
Indole pulse signalling regulates the cytoplasmic pH of E. coli in a memory-like manner
This is the final version. Available from the publisher via the DOI in this record.The data that support the findings of this study are available in Apollo (University of Cambridge Repository) at https://doi.org/10.17863/CAM.26410.Bacterial cells are critically dependent upon pH regulation. Here we demonstrate that indole plays a
critical role in the regulation of the cytoplasmic pH of Escherichia coli. Indole is an aromatic molecule
with diverse signalling roles. Two modes of indole signalling have been described: persistent and
pulse signalling. The latter is illustrated by the brief but intense elevation of intracellular indole during
stationary phase entry. We show that under conditions permitting indole production, cells maintain
their cytoplasmic pH at 7.2. In contrast, under conditions where no indole is produced, the cytoplasmic
pH is near 7.8. We demonstrate that pH regulation results from pulse, rather than persistent, indole
signalling. Furthermore, we illustrate that the relevant property of indole in this context is its ability to
conduct protons across the cytoplasmic membrane. Additionally, we show that the efect of the indole
pulse that occurs normally during stationary phase entry in rich medium remains as a “memory” to
maintain the cytoplasmic pH until entry into the next stationary phase. The indole-mediated reduction
in cytoplasmic pH may explain why indole provides E. coli with a degree of protection against stresses,
including some bactericidal antibiotics.Leverhulme TrustEngineering and Physical Sciences Research Council (EPSRC)Biotechnology and Biological Sciences Research Council (BBSRC)Winton Programme for the Physics of SustainabilityTrinity-Henry Barlow ScholarshipNational Physical Laboratory (UK)European Research Council (ERC
Indole Pulse Signalling Regulates the Cytoplasmic pH of E. coli in a Memory-Like Manner.
Bacterial cells are critically dependent upon pH regulation. Here we demonstrate that indole plays a critical role in the regulation of the cytoplasmic pH of Escherichia coli. Indole is an aromatic molecule with diverse signalling roles. Two modes of indole signalling have been described: persistent and pulse signalling. The latter is illustrated by the brief but intense elevation of intracellular indole during stationary phase entry. We show that under conditions permitting indole production, cells maintain their cytoplasmic pH at 7.2. In contrast, under conditions where no indole is produced, the cytoplasmic pH is near 7.8. We demonstrate that pH regulation results from pulse, rather than persistent, indole signalling. Furthermore, we illustrate that the relevant property of indole in this context is its ability to conduct protons across the cytoplasmic membrane. Additionally, we show that the effect of the indole pulse that occurs normally during stationary phase entry in rich medium remains as a "memory" to maintain the cytoplasmic pH until entry into the next stationary phase. The indole-mediated reduction in cytoplasmic pH may explain why indole provides E. coli with a degree of protection against stresses, including some bactericidal antibiotics.The Leverhulme Trus
Patent Human Infections with the Whipworm, Trichuris trichiura, Are Not Associated with Alterations in the Faecal Microbiota
Background: The soil-transmitted helminth (STH), Trichuris trichiura colonises the human large intestine where it may
modify inflammatory responses, an effect possibly mediated through alterations in the intestinal microbiota. We
hypothesised that patent T. trichiura infections would be associated with altered faecal microbiota and that anthelmintic treatment would induce a microbiota resembling more closely that observed in uninfected individuals.
Materials and Methods: School children in Ecuador were screened for STH infections and allocated to 3 groups: uninfected, T. trichiura only, and mixed infections with T. trichiura and Ascaris lumbricoides. A sample of uninfected children and those with T. trichiura infections only were given anthelmintic treatment. Bacterial community profiles in faecal samples were studied by 454 pyrosequencing of 16 S rRNA genes.
Results: Microbiota analyses of faeces were done for 97 children: 30 were uninfected, 17 were infected with T. trichiura, and 50 with T. trichiura and A. lumbricoides. Post-treatment samples were analyzed for 14 children initially infected with T. trichiura alone and for 21 uninfected children. Treatment resulted in 100% cure of STH infections. Comparisons of the microbiota at different taxonomic levels showed no statistically significant differences in composition between uninfected
children and those with T. trichiura infections. We observed a decreased proportional abundance of a few bacterial genera from the Clostridia class of Firmicutes and a reduced bacterial diversity among children with mixed infections compared to the other two groups, indicating a possible specific effect of A. lumbricoides infection. Anthelmintic treatment of children with T. trichiura did not alter faecal microbiota composition.
Discussion: Our data indicate that patent human infections with T. trichiura may have no effect on faecal microbiota but that A. lumbricoides colonisation might be associated with a disturbed microbiota. Our results also catalogue the microbiota of rural Ecuadorians and indicate differences with individuals from more urban industrialised societies
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