1,105 research outputs found
Evidence of hydrothermal fluid circulation driving elemental mass redistribution in an active fault zone
Important fault zone processes can be discerned from the characterization of fracture damage and chemical transformations associated with active seismic sources. To characterize the 2010 M7.2 El Mayor-Cucapah rupture zone, continuous samples of fault core and 23 samples of damaged rock were collected perpendicular to strike of the Borrego fault. Samples were analyzed for clay mineralogy, bulk geochemistry, and bulk and grain density from which porosities and volumetric strains were derived. Prior to the Borrego fault forming, the tonalitic protolith, containing chlorite, epidote, and titanite, was subjected to temperatures of ∼330–340 °C during deuteric alteration. Rocks within the damage zone are partially pulverized and contain abundant cataclastic seams. Porosity and volumetric strain peak in zones 1.5 m–10.5 m from the core. Within these zones, losses in Ca and P mass, increases in Mg and Na mass, along with the conservation of Fe and Si mass are consistent with oxidizing acidic conditions at < 200 °C. Gains in LOI are attributed to increases in clay content. The above data support a model of Mg- and Na-rich oxidizing fluid circulation within the damage zone of the Borrego fault
Fermentation kinetics including product and substrate inhibitions plus biomass death: a mathematical analysis
Fermentation is generally modelled by kinetic equations giving the time
evolutions for biomass, substrate, and product concentrations. Although these
equations can be solved analytically in simple cases if substrate/product
inhibition and biomass death are included, they are typically solved
numerically. We propose an analytical treatment of the kinetic equations
--including cell death and an arbitrary number of inhibitions-- in which
constant yield needs not be assumed. Equations are solved in phase space, i.e.
the biomass concentration is written explicitly as a function of the substrate
concentration.Comment: 4 pages, 4 figure
A qualitative study of health care professionals' views and experiences of paediatric advance care planning
Background: Good end-of-life care planning is vital to ensure optimal care is provided for patients and their families. Two key factors are open and honest advance care planning conversations between the patient (where possible), family, and health care professionals, focusing on exploring what their future wishes are; and the development of an advance care plan document. However, in paediatric and neonatal settings, there has been little research to demonstrate how advance care planning conversations take place. This study explored health care professionals' views and experiences of paediatric advance care planning in hospitals, community settings and hospices. Methods: A qualitative methodology was employed using purposive sampling of health care professionals involved in the end-of-life care for children aged 0-18 years known to the hospital palliative care team, and had died at least three months before, but less than 18 months prior to the study. Ethics committee approval was obtained for the study. Located in the North of England, the study involved three hospitals, a children's hospice, and community services. Data were collected using semi-structured, digitally recorded, telephone interviews. All interviews were transcribed verbatim and subjected to thematic analysis. Results: Twenty-one health care professionals participated, including generalist paediatric staff as well as specialist palliative care staff. Two themes were generated from the study: The timing of planning conversations, including waiting for the relationship with the family to form; the introduction of parallel planning; avoiding a crisis situation. Secondly, supporting effective conversations around advance care planning, including where to have the conversation; introducing the conversation; and how to approach the topic encompassing the value of advance care planning and documentation for families. Conclusion: The timing of when to start the advance care planning conversations remains an issue for health care professionals. The value of doing it in stages and considering the environment where the conversations are held was noted. Timely planning was seen as vital to avoid difficult conversations at a crisis point and for co-ordination of care. Good advance care planning is to provide the best person-centred care for the child and experience for the family
Ice core measurements of 14CH4 show no evidence of methane release from methane hydrates or old permafrost carbon during a large warming event 11,600 years ago
Thawing permafrost and marine methane hydrate destabilization in the Arctic and elsewhere have been proposed as large sources of methane to the atmosphere in the future warming world. To evaluate this hypothesis it is useful to ask whether such methane releases happened during past warming events. The two major abrupt warming events of the last deglaciation, Oldest Dryas - Bølling (OD-B, ≈ 14,500 years ago) and Younger Dryas - Preboreal (YD-PB; ≈11,600 years ago), were associated with large (up to 50%) increases in atmospheric methane (CH4) concentrations. The sources of these large warming-driven CH4 increases remain incompletely understood, with possible contributions from tropical and boreal wetlands, thawing permafrost as well as marine CH4 hydrates. We present new measurements of 14C of paleoatmospheric CH4 over the YD-PB transition from ancient ice outcropping at Taylor Glacier, Antarctica. 14C can unambiguously identify CH4 emissions from "old carbon" sources, such as permafrost and CH4 hydrates. The only prior study of paleoatmospheric 14CH4 (from Greenland ice) suggested that wetlands were the main driver of the YD-PB CH4 increase, but the results were weakened by an unexpected and poorly understood 14CH4 component from in situ cosmogenic production directly in near-surface ice. In this new study, we have been able to accurately characterize and correct for the cosmogenic 14CH4 component. All samples from before, during and after the abrupt warming and associated CH4 increase yielded 14CH4 values that are consistent with 14C of atmospheric CO2 at that time, indicating a purely contemporaneous methane source. These new measurements rule out the possibility of large CH4 releases to the atmosphere from methane hydrates or old permafrost carbon in response to the large and rapid YD-PB warming. To the extent that the characteristics of the YD-PB warming are comparable to those of the current anthropogenic warming, our measurements suggest that large future atmospheric methane increases from old carbon sources in the Arctic are unlikely. Instead, our measurements indicate that global wetlands will likely respond to the warming with increased methane emissions. © European Geosciences UnionYellow Posters session, Y7
The future burden of lung cancer attributable to current modifiable behaviours: a pooled study of seven Australian cohorts
BACKGROUND: Knowledge of preventable disease and differences in disease burden can inform public health action to improve health and health equity. We quantified the future lung cancer burden preventable by behavioural modifications across Australia. METHODS: We pooled seven Australian cohort studies (n = 367 058) and linked them to national registries to identify lung cancers and deaths. We estimated population attributable fractions and their 95% confidence intervals (CIs) for modifiable risk factors, using risk estimates from the cohort data and risk factor exposure distribution from contemporary national health surveys. RESULTS: During the first 10-year follow-up, there were 2025 incident lung cancers and 20 349 deaths. Stopping current smoking could prevent 53.7% (95% CI, 50.0-57.2%) of lung cancers over 40 years and 18.3% (11.0-25.1%) in 10 years. The smoking-attributable burden is highest in males, those who smoke <20 cigarettes per day, are <75 years of age, unmarried, of lower educational attainment, live in remote areas or are healthy weight. Increasing physical activity and fruit consumption, if causal, could prevent 15.6% (6.9-23.4%) and 7.5% (1.3-13.3%) of the lung cancer burden, respectively. Jointly, the three behaviour modifications could prevent up to 63.0% (58.0-67.5%) of lung cancers in 40 years, and 31.2% (20.9-40.1%) or 43 300 cancers in 10 years. The preventable burden is highest among those with multiple risk factors. CONCLUSIONS: Smoking remains responsible for the highest burden of lung cancer in Australia. The uneven burden distribution distinguishes subgroups that could benefit the most from activities to control the world's deadliest cancer
Protocol for the 'e-Nudge trial' : a randomised controlled trial of electronic feedback to reduce the cardiovascular risk of individuals in general practice [ISRCTN64828380]
Background: Cardiovascular disease (including coronary heart disease and stroke) is a major
cause of death and disability in the United Kingdom, and is to a large extent preventable, by lifestyle
modification and drug therapy. The recent standardisation of electronic codes for cardiovascular
risk variables through the United Kingdom's new General Practice contract provides an
opportunity for the application of risk algorithms to identify high risk individuals. This randomised
controlled trial will test the benefits of an automated system of alert messages and practice
searches to identify those at highest risk of cardiovascular disease in primary care databases.
Design: Patients over 50 years old in practice databases will be randomised to the intervention
group that will receive the alert messages and searches, and a control group who will continue to
receive usual care. In addition to those at high estimated risk, potentially high risk patients will be
identified who have insufficient data to allow a risk estimate to be made. Further groups identified
will be those with possible undiagnosed diabetes, based either on elevated past recorded blood
glucose measurements, or an absence of recent blood glucose measurement in those with
established cardiovascular disease.
Outcome measures: The intervention will be applied for two years, and outcome data will be
collected for a further year. The primary outcome measure will be the annual rate of cardiovascular
events in the intervention and control arms of the study. Secondary measures include the
proportion of patients at high estimated cardiovascular risk, the proportion of patients with missing
data for a risk estimate, and the proportion with undefined diabetes status at the end of the trial
Light hadron, Charmonium(-like) and Bottomonium(-like) states
Hadron physics represents the study of strongly interacting matter in all its
manifestations and the understanding of its properties and interactions. The
interest on this field has been revitalized by the discovery of new light
hadrons, charmonium- and bottomonium-like states. I review the most recent
experimental results from different experiments.Comment: Presented at Lepton-Photon 2011, Mumbai, India; 21 pages, 18 figures;
add more references; some correctio
Genome wide association mapping for arabinoxylan content in a collection of tetraploid wheats
BACKGROUND: Arabinoxylans (AXs) are major components of plant cell walls in bread wheat and are important in bread-making and starch extraction. Furthermore, arabinoxylans are components of soluble dietary fibre that has potential health-promoting effects in human nutrition. Despite their high value for human health, few studies have been carried out on the genetics of AX content in durum wheat. RESULTS: The genetic variability of AX content was investigated in a set of 104 tetraploid wheat genotypes and regions attributable to AX content were identified through a genome wide association study (GWAS). The amount of arabinoxylan, expressed as percentage (w/w) of the dry weight of the kernel, ranged from 1.8% to 5.5% with a mean value of 4.0%. The GWAS revealed a total of 37 significant marker-trait associations (MTA), identifying 19 quantitative trait loci (QTL) associated with AX content. The highest number of MTAs was identified on chromosome 5A (seven), where three QTL regions were associated with AX content, while the lowest number of MTAs was detected on chromosomes 2B and 4B, where only one MTA identified a single locus. Conservation of synteny between SNP marker sequences and the annotated genes and proteins in Brachypodium distachyon, Oryza sativa and Sorghum bicolor allowed the identification of nine QTL coincident with candidate genes. These included a glycosyl hydrolase GH35, which encodes Gal7 and a glucosyltransferase GT31 on chromosome 1A; a cluster of GT1 genes on chromosome 2B that includes TaUGT1 and cisZog1; a glycosyl hydrolase that encodes a CelC gene on chromosome 3A; Ugt12887 and TaUGT1genes on chromosome 5A; a (1,3)-β-D-glucan synthase (Gsl12 gene) and a glucosyl hydrolase (Cel8 gene) on chromosome 7A. CONCLUSIONS: This study identifies significant MTAs for the AX content in the grain of tetraploid wheat genotypes. We propose that these may be used for molecular breeding of durum wheat varieties with higher soluble fibre content.Ilaria Marcotuli, Kelly Houston, Robbie Waugh, Geoffrey B. Fincher, Rachel A. Burton, Antonio Blanco, Agata Gadalet
Stress Strengthens Memory of First Impressions of Others' Positive Personality Traits
Encounters with strangers bear potential for social conflict and stress, but also allow the formation of alliances. First impressions of other people play a critical role in the formation of alliances, since they provide a learned base to infer the other's future social attitude. Stress can facilitate emotional memories but it is unknown whether stress strengthens our memory for newly acquired impressions of other people's personality traits. To answer this question, we subjected 60 students (37 females, 23 males) to an impression-formation task, viewing portraits together with brief positive vs. negative behavior descriptions, followed by a 3-min cold pressor stress test or a non-stressful control procedure. The next day, novel and old portraits were paired with single trait adjectives, the old portraits with a trait adjective matching the previous day's behavior description. After a filler task, portraits were presented again and subjects were asked to recall the trait adjective. Cued recall was higher for old (previously implied) than the novel portraits' trait adjectives, indicating validity of the applied test procedures. Overall, recall rate of implied trait adjectives did not differ between the stress and the control group. However, while the control group showed a better memory performance for others' implied negative personality traits, the stress group showed enhanced recall for others' implied positive personality traits. This result indicates that post-learning stress affects consolidation of first impressions in a valence-specific manner. We propose that the stress-induced strengthening of memory of others' positive traits forms an important cue for the formation of alliances in stressful conditions
Higher-order multipole amplitudes in charmonium radiative transitions
Using 24 million decays in CLEO-c, we have searched
for higher multipole admixtures in electric-dipole-dominated radiative
transitions in charmonia. We find good agreement between our data and
theoretical predictions for magnetic quadrupole (M2) amplitudes in the
transitions and ,
in striking contrast to some previous measurements. Let and
denote the normalized M2 amplitudes in the respective aforementioned decays,
where the superscript refers to the angular momentum of the . By
performing unbinned maximum likelihood fits to full five-parameter angular
distributions, we determine the ratios and , where
the theoretical predictions are independent of the charmed quark magnetic
moment and are and .Comment: 32 pages, 7 figures, acceptance updat
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