21 research outputs found
Faulting and hydration of the Juan de Fuca plate system
Author Posting. © Elsevier B.V., 2009. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Earth and Planetary Science Letters 284 (2009): 94-102, doi:10.1016/j.epsl.2009.04.013.Multichannel seismic observations provide the first direct images of crustal scale normal
faults within the Juan de Fuca plate system and indicate that brittle deformation extends
up to ~200 km seaward of the Cascadia trench. Within the sedimentary layering steeply
dipping faults are identified by stratigraphic offsets, with maximum throws of 110±10 m
found near the trench. Fault throws diminish both upsection and seaward from the trench.
Long-term throw rates are estimated to be 13±2 mm/kyr. Faulted offsets within the
sedimentary layering are typically linked to larger offset scarps in the basement
topography, suggesting reactivation of the normal fault systems formed at the spreading
center. Imaged reflections within the gabbroic igneous crust indicate swallowing fault
dips at depth. These reflections require local alteration to produce an impedance contrast,
indicating that the imaged fault structures provide pathways for fluid transport and
hydration. As the depth extent of imaged faulting within this young and sediment
insulated oceanic plate is primarily limited to approximately Moho depths, fault-
controlled hydration appears to be largely restricted to crustal levels. If dehydration
embrittlement is an important mechanism for triggering intermediate-depth earthquakes
within the subducting slab, then the limited occurrence rate and magnitude of intraslab
seismicity at the Cascadia margin may in part be explained by the limited amount of
water imbedded into the uppermost oceanic mantle prior to subduction. The distribution
of submarine earthquakes within the Juan de Fuca plate system indicates that propagator
wake areas are likely to be more faulted and therefore more hydrated than other parts of
his plate system. However, being largely restricted to crustal levels, this localized
increase in hydration generally does not appear to have a measurable effect on the
intraslab seismicity along most of the subducted propagator wakes at the Cascadia
margin.Supported by the Doherty Foundation and the National Science
449 Foundation under grants OCE002488 and OCE0648303 to SMC and MR
Diving into the vertical dimension of elasmobranch movement ecology
Knowledge of the three-dimensional movement patterns of elasmobranchs is vital to understand their ecological roles and exposure to anthropogenic pressures. To date, comparative studies among species at global scales have mostly focused on horizontal movements. Our study addresses the knowledge gap of vertical movements by compiling the first global synthesis of vertical habitat use by elasmobranchs from data obtained by deployment of 989 biotelemetry tags on 38 elasmobranch species. Elasmobranchs displayed high intra- and interspecific variability in vertical movement patterns. Substantial vertical overlap was observed for many epipelagic elasmobranchs, indicating an increased likelihood to display spatial overlap, biologically interact, and share similar risk to anthropogenic threats that vary on a vertical gradient. We highlight the critical next steps toward incorporating vertical movement into global management and monitoring strategies for elasmobranchs, emphasizing the need to address geographic and taxonomic biases in deployments and to concurrently consider both horizontal and vertical movements
Clinical outcomes and response to treatment of patients receiving topical treatments for pyoderma gangrenosum: a prospective cohort study
Background: pyoderma gangrenosum (PG) is an uncommon dermatosis with a limited evidence base for treatment.
Objective: to estimate the effectiveness of topical therapies in the treatment of PG.
Methods: prospective cohort study of UK secondary care patients with a clinical diagnosis of PG suitable for topical treatment (recruited July 2009 to June 2012). Participants received topical therapy following normal clinical practice (mainly Class I-III topical corticosteroids, tacrolimus 0.03% or 0.1%). Primary outcome: speed of healing at 6 weeks. Secondary outcomes: proportion healed by 6 months; time to healing; global assessment; inflammation; pain; quality-of-life; treatment failure and recurrence.
Results: Sixty-six patients (22 to 85 years) were enrolled. Clobetasol propionate 0.05% was the most commonly prescribed therapy. Overall, 28/66 (43.8%) of ulcers healed by 6 months. Median time-to-healing was 145 days (95% CI: 96 days, ∞). Initial ulcer size was a significant predictor of time-to-healing (hazard ratio 0.94 (0.88;80 1.00); p = 0.043). Four patients (15%) had a recurrence.
Limitations: No randomised comparator
Conclusion: Topical therapy is potentially an effective first-line treatment for PG that avoids possible side effects associated with systemic therapy. It remains unclear whether more severe disease will respond adequately to topical therapy alone
Diving into the vertical dimension of elasmobranch movement ecology
Knowledge of the three-dimensional movement patterns of elasmobranchs is vital to understand their ecological roles and exposure to anthropogenic pressures. To date, comparative studies among species at global scales have mostly focused on horizontal movements. Our study addresses the knowledge gap of vertical movements by compiling the first global synthesis of vertical habitat use by elasmobranchs from data obtained by deployment of 989 biotelemetry tags on 38 elasmobranch species. Elasmobranchs displayed high intra- and interspecific variability in vertical movement patterns. Substantial vertical overlap was observed for many epipelagic elasmobranchs, indicating an increased likelihood to display spatial overlap, biologically interact, and share similar risk to anthropogenic threats that vary on a vertical gradient. We highlight the critical next steps toward incorporating vertical movement into global management and monitoring strategies for elasmobranchs, emphasizing the need to address geographic and taxonomic biases in deployments and to concurrently consider both horizontal and vertical movements
Diving into the vertical dimension of elasmobranch movement ecology
Knowledge of the three-dimensional movement patterns of elasmobranchs is vital to understand their ecological roles and exposure to anthropogenic pressures. To date, comparative studies among species at global scales have mostly focused on horizontal movements. Our study addresses the knowledge gap of vertical movements by compiling the first global synthesis of vertical habitat use by elasmobranchs from data obtained by deployment of 989 biotelemetry tags on 38 elasmobranch species. Elasmobranchs displayed high intra- and interspecific variability in vertical movement patterns. Substantial vertical overlap was observed for many epipelagic elasmobranchs, indicating an increased likelihood to display spatial overlap, biologically interact, and share similar risk to anthropogenic threats that vary on a vertical gradient. We highlight the critical next steps toward incorporating vertical movement into global management and monitoring strategies for elasmobranchs, emphasizing the need to address geographic and taxonomic biases in deployments and to concurrently consider both horizontal and vertical movements
BHPR research: qualitative1. Complex reasoning determines patients' perception of outcome following foot surgery in rheumatoid arhtritis
Background: Foot surgery is common in patients with RA but research into surgical outcomes is limited and conceptually flawed as current outcome measures lack face validity: to date no one has asked patients what is important to them. This study aimed to determine which factors are important to patients when evaluating the success of foot surgery in RA Methods: Semi structured interviews of RA patients who had undergone foot surgery were conducted and transcribed verbatim. Thematic analysis of interviews was conducted to explore issues that were important to patients. Results: 11 RA patients (9 ♂, mean age 59, dis dur = 22yrs, mean of 3 yrs post op) with mixed experiences of foot surgery were interviewed. Patients interpreted outcome in respect to a multitude of factors, frequently positive change in one aspect contrasted with negative opinions about another. Overall, four major themes emerged. Function: Functional ability & participation in valued activities were very important to patients. Walking ability was a key concern but patients interpreted levels of activity in light of other aspects of their disease, reflecting on change in functional ability more than overall level. Positive feelings of improved mobility were often moderated by negative self perception ("I mean, I still walk like a waddling duck”). Appearance: Appearance was important to almost all patients but perhaps the most complex theme of all. Physical appearance, foot shape, and footwear were closely interlinked, yet patients saw these as distinct separate concepts. Patients need to legitimize these feelings was clear and they frequently entered into a defensive repertoire ("it's not cosmetic surgery; it's something that's more important than that, you know?”). Clinician opinion: Surgeons' post operative evaluation of the procedure was very influential. The impact of this appraisal continued to affect patients' lasting impression irrespective of how the outcome compared to their initial goals ("when he'd done it ... he said that hasn't worked as good as he'd wanted to ... but the pain has gone”). Pain: Whilst pain was important to almost all patients, it appeared to be less important than the other themes. Pain was predominately raised when it influenced other themes, such as function; many still felt the need to legitimize their foot pain in order for health professionals to take it seriously ("in the end I went to my GP because it had happened a few times and I went to an orthopaedic surgeon who was quite dismissive of it, it was like what are you complaining about”). Conclusions: Patients interpret the outcome of foot surgery using a multitude of interrelated factors, particularly functional ability, appearance and surgeons' appraisal of the procedure. While pain was often noted, this appeared less important than other factors in the overall outcome of the surgery. Future research into foot surgery should incorporate the complexity of how patients determine their outcome Disclosure statement: All authors have declared no conflicts of interes
Inheritance of DNA methylation level in healthy human tissues
DNA methylation (DNAm) is the covalent modification of DNA by addition of a
methyl group primarily at the cytosine directly upstream of a guanine. DNAm level
plays a central role in transcriptional regulation and is linked to disease. Therefore,
understanding genetic and environmental influences on DNAm level in healthy
tissue is an important step in the elucidation of trait and disease etiology. However,
at present only a minority of easy to access human tissues and ethnicities have been
investigated.
Therefore, we studied DNAm level measured in five human tissues: cerebellum,
frontal cortex, pons, temporal cortex and colon in either North American or South
American samples. We applied a novel statistical approach to estimate the
heritability attributable to genomic regions (regional heritability, ĥ²/r,g ) for DNAm
level at thousands of individual DNAm sites genome-wide.
In all five tissues, DNAm level was significantly associated with the local genomic
region for more DNAm sites than expected by chance. Moreover, DNAm level could
be predicted from the local sequence variants with an accuracy that scaled with the
estimated ĥ²/r,g .
Our results inform on molecular mechanisms regulating DNAm level and trait
etiology in several ways. Firstly, DNAm level at DNAm sites located in genomic risk
regions and measured in a tissue relevant to the disease can be influenced by the
local genetic variants. Specifically, we found that genetic variation within a region
associated with Fluid Intelligence was also associated with local DNAm level at the
proline-rich coiled-coil 1 (PRRC1) gene in healthy temporal cortex tissue.
Additionally, we replicated the finding of a Colorectal Cancer risk variant
(rs4925386) associated with two DNAm sites in healthy colon tissue. More
generally, we showed that DNAm sites located within a susceptibility region and
measured in a relevant tissue exhibit a similar overall pattern of estimated ĥ²/r,g to
DNAm sites outwith a susceptibility region. Secondly, the propensity for DNAm
level to be associated with the local sequence variation differs with respect to CpG
dinucleotide density and genic location. Most notably, DNAm sites located in CpG
dense regions of the genome are less likely to be heritable than DNAm sites located
in CpG sparse regions of the genome. Additionally, within both CpG dense and CpG
sparse regions of the genome intergenic DNAm sites are more likely to be heritable
than intragenic DNAm sites. Overall, our study suggests that variation in DNAm
level at some DNAm sites is at least partially controlled by nuclear genetic variation.
Moreover, DNAm level in healthy tissue has the potential to act as an intermediary in
trait variation and etiology
Tetramic Acid Analogues Produced by Coculture of <i>Saccharopolyspora erythraea </i>with<i> Fusarium pallidoroseum</i>
Coculture of the fungus <i>Fusarium
pallidoroseum</i> with
the bacterium <i>Saccharopolyspora erythraea</i> was found
to produce three new
decalin-type tetramic acid analogues related to equisetin. The structures
were determined by spectroscopic methods. The absolute configurations
were established by circular dichroism spectroscopy and comparing
the data with those of equisetin