5,276 research outputs found

    Krill oil attenuates left ventricular dilatation after myocardial infarction in rats

    Get PDF
    Background: In the western world, heart failure (HF) is one of the most important causes of cardiovascular mortality. Supplement with n-3 polyunsaturated fatty acids (PUFA) has been shown to improve cardiac function in HF and to decrease mortality after myocardial infarction (MI). The molecular structure and composition of n-3 PUFA varies between different marine sources and this may be of importance for their biological effects. Krill oil, unlike fish oil supplements, contains the major part of the n-3 PUFA in the form of phospholipids. This study investigated effects of krill oil on cardiac remodeling after experimental MI. Rats were randomised to pre-treatment with krill oil or control feed 14 days before induction of MI. Seven days post-MI, the rats were examined with echocardiography and rats in the control group were further randomised to continued control feed or krill oil feed for 7 weeks before re-examination with echocardiography and euthanization. Results: The echocardiographic evaluation showed significant attenuation of LV dilatation in the group pretreated with krill oil compared to controls. Attenuated heart weight, lung weight, and levels of mRNA encoding classical markers of LV stress, matrix remodeling and inflammation reflected these findings. The total composition of fatty acids were examined in the left ventricular (LV) tissue and all rats treated with krill oil showed a significantly higher proportion of n-3 PUFA in the LV tissue, although no difference was seen between the two krill oil groups. Conclusions: Supplement with krill oil leads to a proportional increase of n-3 PUFA in myocardial tissue and supplement given before induction of MI attenuates LV remodeling

    On virialization with dark energy

    Full text link
    We review the inclusion of dark energy into the formalism of spherical collapse, and the virialization of a two-component system, made of matter and dark energy. We compare two approaches in previous studies. The first assumes that only the matter component virializes, e.g. as in the case of a classic cosmological constant. The second approach allows the full system to virialize as a whole. We show that the two approaches give fundamentally different results for the final state of the system. This might be a signature discriminating between the classic cosmological constant which cannot virialize and a dynamical dark energy mimicking a cosmological constant. This signature is independent of the measured value of the equation of state. An additional issue which we address is energy non-conservation of the system, which originates from the homogeneity assumption for the dark energy. We propose a way to take this energy loss into account.Comment: 15 pages, 5 figures. Accepted for publication in JCA

    Resipientundersøkelser i Ballangsfjorden 2000. Kildesporing, metallinnhold i fisk og blåskjell samt mulige effekter på fisk

    Get PDF
    Årsliste 2001Torsk, rødspette, sandflyndre og blåskjell fra Ballangsfjorden kunne i hovedsak karakteriseres som ubetydelig til lite forurenset. Konsentrasjoner av metaller (Pb, Hg, Cd, Ni, Cu) og arsen (As) klart over bakgrunnsnivåer, ble kun observert i ytre del av Ballangsfjorden og da for Hg i sandflyndre (ca 2.5 x antatt bakgrunn) og muligens As i rødspette (meget usikker bakgrunn). Det noe forhøyede Hg-innholdet i sandflyndre kan trolig ikke knyttes til utslipp av avgang til Ballangsfjorden. I torskelever er blyisotopsammensetningen (206Pb/207Pb forhold) mer lik avgang fra Bjørkåsen gruver enn fra Nikkel og Olivin A/S. Isotopforholdet i skjell fra den indre stasjonen (BI) er mer likt forholdet i avgang (begge typer) enn skjell fra den ytre stasjonen. Isotopanalysene kan tyde på at kilden til den diffuse belastningen på skjell i ytre område er forskjellig fra den noe tydeligere påvirkning observert i torskelever. I begge tilfeller synes imidlertid andre blykilder enn de to avgangstyper (muligens markavrenning og atmosfæretransportert bly) å være fremtredende. Totalt sett tyder blyisotopsammensettningen på at avgang fra Nikkel og Olivin A/S ikke er en betydelig kilde for bly i organismer i Ballangsfjorden. Biomarkøranalyser viser at metaller i avgangen fra gruvedriften ikke gir noen tydelige effekter på fisk. Beregninger antyder at man kan spise 150 kg pr. uke med fiskefilet før FNs anbefalinger for maksimalt inntak av Pb og Cd nås. Tilsvarende verdier for torskelever og blåskjell ligger på mer enn 2.3 kg pr. uke. Beregninger for Hg og As gir et trygt konsum av fiskefilet i området 1.2-25 og 0.7-12.2 kg pr uke. Hg innholdet i sandflyndre og As innholdet i filet av rødspette (begge fra ytre område) er de forbindelser/vev som tillater lavest konsum. Med utgangspunkt i FNs (JECFA) anbefalinger (PTWI/PMTDI) synes det lite trolig at de observerte metallkonsentrasjoner har betydning for bruken av fjorden. Det er imidlertid SNT som er den rette instans for å avgjøre den endelige betydningen for spiselighet av de konsentrasjoner av metaller og arsen som er funnet i fisk og blåskjell fra Ballangsfjorden.Nikkel og Olivin A/

    A search for VHE counterparts of Galactic Fermi bright sources and MeV to TeV spectral characterization

    Full text link
    Very high-energy (VHE; E>100 GeV) gamma-rays have been detected from a wide range of astronomical objects, such as pulsar wind nebulae (PWNe), supernova remnants (SNRs), giant molecular clouds, gamma-ray binaries, the Galactic Center, active galactic nuclei (AGN), radio galaxies, starburst galaxies, and possibly star-forming regions as well. At lower energies, observations using the Large Area Telescope (LAT) onboard Fermi provide a rich set of data which can be used to study the behavior of cosmic accelerators in the MeV to TeV energy bands. In particular, the improved angular resolution of current telescopes in both bands compared to previous instruments significantly reduces source confusion and facilitates the identification of associated counterparts at lower energies. In this paper, a comprehensive search for VHE gamma-ray sources which are spatially coincident with Galactic Fermi/LAT bright sources is performed, and the available MeV to TeV spectra of coincident sources are compared. It is found that bright LAT GeV sources are correlated with TeV sources, in contrast to previous studies using EGRET data. Moreover, a single spectral component seems unable to describe the MeV to TeV spectra of many coincident GeV/TeV sources. It has been suggested that gamma-ray pulsars may be accompanied by VHE gamma-ray emitting nebulae, a hypothesis that can be tested with VHE observations of these pulsars.Comment: Astronomy and Astrophysics, in press, 17 pages, 12 figures, 5 table

    Testing Consumer Rationality using Perfect Graphs and Oriented Discs

    Full text link
    Given a consumer data-set, the axioms of revealed preference proffer a binary test for rational behaviour. A natural (non-binary) measure of the degree of rationality exhibited by the consumer is the minimum number of data points whose removal induces a rationalisable data-set.We study the computational complexity of the resultant consumer rationality problem in this paper. This problem is, in the worst case, equivalent (in terms of approximation) to the directed feedback vertex set problem. Our main result is to obtain an exact threshold on the number of commodities that separates easy cases and hard cases. Specifically, for two-commodity markets the consumer rationality problem is polynomial time solvable; we prove this via a reduction to the vertex cover problem on perfect graphs. For three-commodity markets, however, the problem is NP-complete; we prove thisusing a reduction from planar 3-SAT that is based upon oriented-disc drawings

    Proceedings of the third French-Ukrainian workshop on the instrumentation developments for HEP

    Full text link
    The reports collected in these proceedings have been presented in the third French-Ukrainian workshop on the instrumentation developments for high-energy physics held at LAL, Orsay on October 15-16. The workshop was conducted in the scope of the IDEATE International Associated Laboratory (LIA). Joint developments between French and Ukrainian laboratories and universities as well as new proposals have been discussed. The main topics of the papers presented in the Proceedings are developments for accelerator and beam monitoring, detector developments, joint developments for large-scale high-energy and astroparticle physics projects, medical applications.Comment: 3rd French-Ukrainian workshop on the instrumentation developments for High Energy Physics, October 15-16, 2015, LAL, Orsay, France, 94 page

    Spatial and temporal variations in ammonia emissions – a freely accessible model code for Europe

    Get PDF
    Deriving a parameterisation of ammonia emissions for use in chemistry-transport models (CTMs) is a complex problem as the emission varies locally as a result of local climate and local agricultural management. In current CTMs such factors are generally not taken into account. This paper demonstrates how local climate and local management can be accounted for in CTMs by applying a modular approach for deriving data as input to a dynamic ammonia emission model for Europe. Default data are obtained from information in the RAINS system, and it is demonstrated how this dynamic emission model based on these input data improves the NH<sub>3</sub> calculations in a CTM model when the results are compared with calculations obtained by traditional methods in emission handling. It is also shown how input data can be modified over a specific target region resulting in even further improvement in performance over this domain. The model code and the obtained default values for the modelling experiments are available as supplementary information to this article for use by the modelling community on similar terms as the EMEP CTM model: the GPL licencse v3

    Community‐Engaged Neighborhood Revitalization and Empowerment: Busy Streets Theory in Action

    Full text link
    Busy streets theory predicts that engaging residents in physical revitalization of neighborhoods will facilitate community empowerment through the development of sense of community, social cohesion, collective efficacy, social capital, and behavioral action. Establishing safe environments fosters positive street activity, which reinforces neighborhood social relationships. A community‐engaged approach to crime prevention through environmental design (CE‐CPTED) is one promising approach to creating busy streets because it engages residents in collaborative interactions to promote safer environments. Yet, few researchers have studied how CE‐CPTED may be associated with busy streets. We interviewed 18 residents and stakeholders implementing CE‐CPTED in Flint, Michigan. We studied three neighborhoods with different levels of resident control over CE‐CPTED. Participants described how CE‐CPTED implementation affected their neighborhood. Participants from all three neighborhoods reported that CE‐CPTED was associated with positive street activity, sense of community, and collective efficacy. Participants from neighborhoods with higher resident control of CE‐CPTED reported more social capital and behavioral action than those from neighborhoods with less resident control. Our findings support busy streets theory: Community engagement in neighborhood improvement enhanced community empowerment. CE‐CPTED that combines physical revitalization with resident engagement and control creates a potent synergy for promoting safe and healthy neighborhoods.HighlightsBusy streets theory supported in qualitative study of neighborhoods in a rust belt city.Community engaged neighborhood improvement enhances psychological empowerment.Resident control of neighborhood revitalization results in most empowered outcomes of busy streets.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154635/1/ajcp12358_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154635/2/ajcp12358.pd
    corecore