1. |
- Morganti, R., et al.
(författare)
-
Continuum surveys with LOFAR and synergy with future large surveys in the 1 – 2 GHz band
- 2009
-
Ingår i: Proceedings of Science. - 1824-8039. ; 89
-
Konferensbidrag (refereegranskat)abstract
- Radio astronomy is entering the era of large surveys. This paper describes the plans for wide surveys with the LOw Frequency ARray (LOFAR) and their synergy with large surveys at higher frequencies (in particular in the 1 – 2 GHz band) that will be possible using future facilities like Apertif or ASKAP. The LOFAR Survey Key Science Project aims at conducting large-sky surveys at 15, 30, 60, 120 and 200 MHz taking advantage of the wide instantaneous field of view and of the unprecedented sensitivity of this instrument.
|
|
2. |
- Snellen, I., et al.
(författare)
-
Future investigations of GPS and CSS radio sources with LOFAR
- 2009
-
Ingår i: Astronomische Nachrichten. - : Wiley. - 0004-6337 .- 1521-3994. ; 330:2-3, s. 297-300
-
Tidskriftsartikel (refereegranskat)abstract
- In the next few years, the Low Frequency Array (LOFAR) will open up one of the last astronomically unexplored wavelength regimes. While the LOFAR core is currently being erected in the Netherlands, its outer stations will cover a large part of Europe, resulting in an unprecedented angular resolution at > meter wavelengths. Next to many other exciting scientific endeavours, LOFAR will be the first instrument to probe the low frequency spectra of Gigahertz Peaked Spectrum (GPS) and Compact Steep Spectrum (CSS) radio sources. It will give new insights into their absorption processes, and probe associated extended emission (possibly linked to earlier epochs of activity) in these enigmatic class of young active galactic nuclei. Furthermore, LOFAR will be sensitive to possibly the most distant GPS and CSS sources, of which their spectral turnovers have redshifted down to the lowest observable radio frequencies.
|
|
3. |
- Schmid, M, et al.
(författare)
-
Short-term sleep loss decreases physical activity under free-living conditions but does not increase food intake under time-deprived laboratory conditions in healthy men
- 2009
-
Ingår i: American Journal of Clinical Nutrition. - : Elsevier BV. - 0002-9165 .- 1938-3207. ; 90:6, s. 1476-1482
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Short sleep duration is correlated with an increased risk of developing obesity and cardiovascular disease, but the mechanisms behind this relation are largely unknown.Objective: We aimed to test the hypothesis that acute sleep loss decreases physical activity while increasing food intake, thereby shifting 2 crucial behavioral components of energy homeostasis toward weight gain.Design: In 15 healthy, normal-weight men, spontaneous physical activity was registered by accelerometry during the entire experiment, and food intake as well as relevant hormones were assessed during a 15-h daytime period after 2 nights of regular sleep (bed time: 2245-0700) and after 2 nights of restricted sleep (bed time: 0245-0700). Experiments were performed in a crossover design.Results: Sleep restriction significantly decreased physical activity during the daytime spent under free-living conditions after the first night of sleep manipulation (P = 0.008). Also, intensities of physical activity were shifted toward lower levels, with less time spent with intense activities (P = 0.046). Total energy intake, feelings of hunger, and appetite as well as ghrelin and leptin concentrations during day 2 remained unaffected by acute sleep restriction.Conclusions: In contrast to our expectation, short-term sleep loss neither increased food intake nor affected concentrations of the hunger-regulating hormones leptin and ghrelin. However, the observed decrease in daytime physical activity may point to another potentially important behavioral mechanism for the health-impairing influence of sleep loss.
|
|
4. |
|
|
5. |
|
|