348 research outputs found
Characterization of the optical and X-ray properties of the northwestern wisps in the Crab Nebula
We have studied the wisps to the north-west of the Crab pulsar as part of a
multi-wavelength campaign in the visible and in X-rays. Optical observations
were obtained using the Nordic Optical Telescope in La Palma and X-ray
observations were made with the Chandra X-ray Observatory. The observing
campaign took place from 2010 October until 2012 September. About once per year
we observe wisps forming and peeling off from (or near) the region commonly
associated with the termination shock of the pulsar wind. We find that the
exact locations of the northwestern wisps in the optical and in X-rays are
similar but not coincident, with X-ray wisps preferentially located closer to
the pulsar. This suggests that the optical and X-ray wisps are not produced by
the same particle distribution. Our measurements and their implications are
interpreted in terms of a Doppler-boosted ring model that has its origin in
magne- tohydrodynamic (MHD) modelling. While the Doppler boosting factors
inferred from the X-ray wisps are consistent with current MHD simulations of
pulsar wind nebulae (PWN), the optical boosting factors are not, and typically
exceed values from MHD simulations by about a factor of 3.Comment: 11 pages, 12 figure
Kvinners opplevelser av trening under og etter hjerterehabilitering
Hensikt: Å utdype forståelsen av hva kvinner opplever som viktig i hjerterehabilitering
i fase 2 med tanke på å styrke troen på egen kropp og motivere til trening og
fysisk aktivitet etter en hjertehendelse.
Design og metode: En kvalitativ studie basert på et fokusgruppeintervju, analysert
gjennom systematisk tekstkondensering.
Materiale: Fire kvinner som hadde deltatt i hjerterehabilitering i primærhelsetjenesten.
Funn: To hovedtemaer ble identifisert; «Styrket tro på egen kropp» og «Fra ledet til
selvstyrt – istandsatt gjennom kroppslige erfaringer, erkjennelse og forståelse».
Konklusjon: Denne studien viser at tidlig oppstart med treningsbasert rehabilitering
gir viktige erfaringer som bidrar til styrket tro på egen kropp, redusert engstelse for
hva hjertet tåler og økt bevissthet på betydningen av trening og fysisk aktivitet.
Kompetente fysioterapeuter og likemenn trekkes frem som avgjørende bidragsytere i
prosessen
Oxidized Dietary Oil, High in Omega-3 and Omega-6 Polyunsaturated Fatty Acids, Induces Antioxidant Responses in a Human Intestinal HT29 Cell Line
When oxidized, dietary oils generate products which have the potential to cause adverse effects on human health. The objective of the study was to investigate whether lipid oxidation products in an oxidized dietary oil can be taken up in intestinal cells, induce antioxidant stress responses and potentially be harmful. The in vitro cell model HT29 was exposed to camelina oil with different extents of oxidation, or only 4-hydroxy-2-hexenal (HHE) or 4-hydroxy-2-nonenal (HNE). The cellular content of HHE increased with an increasing extent of oxidation of the camelina oil added to the cell’s growth media, whereas HNE did not show a similar trend. Deuterated HHE was taken up by the HT29 cells, with 140 μM HHE metabolized within 0.5–1 h. The low oxidation degree of the camelina oil increased the gene expression of antioxidant markers (GPX, ATF6, XBP1). The increase in the gene expression of SOD at medium oxidation levels of the oil might indicate different regulation mechanisms. Highly oxidized camelina oil and a low concentration of HHE, over time, induced SOD and catalase enzyme activity in HT29 cells. Oxidized camelina oil contains multiple oxidation products which can be responsible for the intracellular responses observed in HT29 cells, while HHE and HNE in combination with other oxidation products induce antioxidant defence responses.publishedVersio
Current state of mixed forests available for wood supply in Finland and Sweden
This study's objectives were to suggest harmonised criteria for the definition of mixed forests for two Nordic countries, describe their principal mixture types, and provide an overview of their current extent. We used national forest inventory data compiled in Finland and Sweden, considering the forest available for wood supply (FAWS), excluding seedling and sapling plots before canopy closure. The definition of the mixed forest was based on the threshold criteria, which indicate the basal area proportion of the dominant tree species of the total in a stand. The proportion of mixed forests increased with higher threshold criteria: 21% to 42% in Finland and 24% to 49% in Sweden, as the threshold criterion was changed from 65% to 85%. With a threshold criterion of 75%, the area of mixed FAWS was 5.6 million ha (31% of FAWS) in Finland and 6.5 million ha (36%) in Sweden. The dominant mixture type was the pine-spruce-birches mixture (31%) in Finland and the pine-spruce mixture (29%) in Sweden. The proportion of peatland forest of mixed forests was similar in the countries: 9-10%. The mixed forests proportion increased from north boreal to hemiboreal, increasing with more mature development classes
Connection Between Optical and VHE Gamma-ray Emission in Blazar Jets
MAGIC has been performing optically triggered Target of Opportunity
observations of flaring blazars since the beginning of its scientific
operations. The alerts of flaring blazars originate from Tuorla Blazar
Monitoring Programme, which started the optical monitoring of candidtate TeV
blazars in 2002 and has now collected up to eight years of data on more than 60
blazars. These ToO observations have resulted in the discovery of five new VHE
gamma-ray emitting blazars (S5 0716+714, 1ES 1011+496, Mrk 180, ON 325 and B3
2247+381). In addition part of the discovery of BL Lac and the discovery of 3C
279 was made during a high optical state. In this contribution we present a
detailed analysis of the optical light curves which are then compared to MAGIC
observations of the same sources. We aim to answer the question: "Is there a
connection between optical and VHE -ray high states in blazars or have we just
been lucky?"Comment: 6 pages, 1 figure, 2 tables, proceedings for the Beamed and Unbeamed
Gamma-Rays from Galaxies workshop, Olos, April 11-15 201
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