6,234 research outputs found
The omega-3 fatty acid, eicosapentaenoic acid (EPA), prevents the damaging effects of tumour necrosis factor (TNF)-alpha during murine skeletal muscle cell differentiation
Background: Eicosapentaenoic acid (EPA) is a -3 polyunsaturated fatty acid with antiinflammatory
and anti-cachetic properties that may have potential benefits with regards to skeletal muscle atrophy conditions where inflammation is present. It is also reported that pathologic levels of the pro-inflammatory cytokine tumour necrosis factor (TNF)-α are associated with muscle wasting, exerted through inhibition of myogenic differentiation and enhanced apoptosis. These findings led us to hypothesize that EPA may have a protective effect against skeletal muscle damage induced by the actions of TNF-α.
Results: The deleterious effects of TNF-α on C2C12 myogenesis were completely inhibited by co-treatment with EPA. Thus, EPA prevented the TNF-mediated loss of MyHC expression and significantly increased myogenic fusion (p < 0.05) and myotube diameter (p < 0.05) indices back to
control levels. EPA protective activity was associated with blocking cell death pathways as EPA completely attenuated TNF-mediated increases in caspase-8 activity (p < 0.05) and cellular necrosis (p < 0.05) back to their respective control levels. EPA alone significantly reduced spontaneous
apoptosis and necrosis of differentiating myotubes (p < 0.001 and p < 0.05, respectively). A 2 hour pre-treatment with EPA, prior to treatment with TNF alone, gave similar results.
Conclusion: In conclusion, EPA has a protective action against the damaging effects of TNF-α on C2C12 myogenesis. These findings support further investigations of EPA as a potential therapeutic agent during skeletal muscle regeneration following injury
Regis-Darwin specified in the p-Calculus
There now is a translator for DARWIN programs that automatically generates their Ï-calculus equivalents. A variety of errors in DARWIN programs can be detected at the Ï-calculus level. These include detection of recursive structures, unbound ports and ports that are bound in the wrong direction. It can also be used to confirm whether two REGIS-DARWIN programs are equivalent
COMPLACENT OR COMPETITIVE? BRITISH EXPORTERS AND THE DRIFT TO EMPIRE
The belief that Britainâs empire markets were soft is well entrenched in the literature. It is, however, a belief that has been largely untested. Indeed, the literature does not even offer an explicit definition of softness. This paper attempts to fill this gap by discussing the meaning of the term and, then, posing the question whether between 1870 and 1914 Britainâs fastest growing markets â Australasia and Canada â can in fact be reasonably labelled soft, as has often been assumed. The paper concludes that the demand for British imports in these markets were driven more by income and price considerations than by colonial sentiment or preference.Empire markets, soft markets, British exports, imperial sentiments
Monitoring and control in scenario-based requirements analysis
Scenarios are an effective means for eliciting, validating and documenting requirements. At the requirements level, scenarios describe sequences of interactions between the software-to-be and agents in the environment. Interactions correspond to the occurrence of an event that is controlled by one agent and monitored by another.This paper presents a technique to analyse requirements-level scenarios for unforeseen, potentially harmful, consequences. Our aim is to perform analysis early in system development, where it is highly cost-effective. The approach recognises the importance of monitoring and control issues and extends existing work on implied scenarios accordingly. These so-called input-output implied scenarios expose problematic behaviours in scenario descriptions that cannot be detected using standard implied scenarios. Validation of these implied scenarios supports requirements elaboration. We demonstrate the relevance of input-output implied scenarios using a number of examples
Adhesive coating eliminated in new honeycomb-core fabrication process
Technique eliminates use of silicone-based adhesive material as bonding medium. Adhesive requires precise time-temperature cure. Prepreg resin is used as bonding medium, and each layer is laminated together to form honeycomb billet. Process can be used in any application where nonmetallic honeycomb core is being fabricated
The investigation of flame spreading over the surface of igniting solid propellants Final summary report
Flame spreading over surface of igniting solid propellants in different gas mixtures at various pressure
Detecting the signatures of helium in type Iax supernovae
Recent studies have argued that the progenitor system of type Iax supernovae
must consist of a carbon-oxygen white dwarf accreting from a helium star
companion. Based on existing explosion models invoking the pure deflagration of
carbon-oxygen white dwarfs, we investigate the likelihood of producing spectral
features due to helium in type Iax supernovae. From this scenario, we select
those explosion models producing ejecta and Ni masses that are broadly
consistent with those estimated for type Iax supernovae (0.014 -
0.478~ and - 0.183~, respectively). To this
end, we present a series of models of varying luminosities (~mag) with helium abundances accounting for up to
36\% of the ejecta mass, and covering a range of epochs beginning a few
days before Bband maximum to approximately two weeks after maximum. We find
that the best opportunity for detecting \ion{He}{i} features is at
near-infrared wavelengths, and in the post-maximum spectra of the fainter
members of this class. We show that the optical spectrum of SN~2007J is
potentially consistent with a large helium content (a few 10),
but argue that current models of accretion and material stripping from a
companion struggle to produce compatible scenarios. We also investigate the
presence of helium in all objects with near-infrared spectra. We show that
SNe~2005hk, 2012Z, and 2015H contain either no helium or their helium
abundances are constrained to much lower values
(10). Our results demonstrate the differences in
helium content among type Iax supernovae, perhaps pointing to different
progenitor channels. Either SN~2007J is an outlier in terms of its progenitor
system, or it is not a true member of the type Iax supernova class.Comment: 15 pages, 12 figures, 2 tables. Accepted for publication in Astronomy
and Astrophysic
Public views on the donation and use of human biological samples in biomedical research: a mixed methods study
Objective A mixed methods study exploring the UK general public's willingness to donate human biosamples (HBSs) for biomedical research.<p></p>
Setting Cross-sectional focus groups followed by an online survey.<p></p>
Participants Twelve focus groups (81 participants) selectively sampled to reflect a range of demographic groups; 1110 survey responders recruited through a stratified sampling method with quotas set on sex, age, geographical location, socioeconomic group and ethnicity.<p></p>
Main outcome measures (1) Identify participantsâ willingness to donate HBSs for biomedical research, (2) explore acceptability towards donating different types of HBSs in various settings and (3) explore preferences regarding use and access to HBSs.<p></p>
Results 87% of survey participants thought donation of HBSs was important and 75% wanted to be asked to donate in general. Responders who self-reported having some or good knowledge of the medical research process were significantly more likely to want to donate (p<0.001). Reasons why focus group participants saw donation as important included: it was a good way of reciprocating for the medical treatment received; it was an important way of developing drugs and treatments; residual tissue would otherwise go to waste and they or their family members might benefit. The most controversial types of HBSs to donate included: brain post mortem (29% would donate), eyes post mortem (35%), embryos (44%), spare eggs (48%) and sperm (58%). Regarding the use of samples, there were concerns over animal research (34%), research conducted outside the UK (35%), and research conducted by pharmaceutical companies (56%), although education and discussion were found to alleviate such concerns.<p></p>
Conclusions There is a high level of public support and willingness to donate HBSs for biomedical research. Underlying concerns exist regarding the use of certain types of HBSs and conditions under which they are used. Improved education and more controlled forms of consent for sensitive samples may mitigate such concerns.<p></p>
Flame Spreading over the Surface of Double Base Propellants at High Pressure Annual Report
Flame spreading over igniting surface of double base propellants in high pressure quiescent environmen
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