We assemble a sample of 24 hydrogen-poor superluminous supernovae (SLSNe). Parameterizing the light-curve shape through rise and decline time-scales shows that the two are highly correlated. ...Magnetar-powered models can reproduce the correlation, with the diversity in rise and decline rates driven by the diffusion time-scale. Circumstellar interaction models can exhibit a similar rise–decline relation, but only for a narrow range of densities, which may be problematic for these models. We find that SLSNe are approximately 3.5 mag brighter and have light curves three times broader than SNe Ibc, but that the intrinsic shapes are similar. There are a number of SLSNe with particularly broad light curves, possibly indicating two progenitor channels, but statistical tests do not cleanly separate two populations. The general spectral evolution is also presented. Velocities measured from Fe ii are similar for SLSNe and SNe Ibc, suggesting that diffusion time differences are dominated by mass or opacity. Flat velocity evolution in most SLSNe suggests a dense shell of ejecta. If opacities in SLSNe are similar to other SNe Ibc, the average ejected mass is higher by a factor 2–3. Assuming κ = 0.1 cm2 g−1, we estimate a mean (median) SLSN ejecta mass of 10 M⊙ (6 M⊙), with a range of 3–30 M⊙. Doubling the assumed opacity brings the masses closer to normal SNe Ibc, but with a high-mass tail. The most probable mechanism for generating SLSNe seems to be the core collapse of a very massive hydrogen-poor star, forming a millisecond magnetar.
•Mini-RF on LRO collected bistatic S-band radar data of the lunar nearside from 2012 to 2015 to observe the scattering characteristics of the upper meter(s) of the lunar regolith.•An opposition ...effect was observed for the ejecta blankets of two Copernican-aged craters and for the floor of the south-polar crater Cabeus.•The unique response of Cabeus floor materials may indicate the presence of water ice.
The Miniature Radio Frequency (Mini-RF) instrument aboard NASA's Lunar Reconnaissance Orbiter (LRO) is a hybrid dual-polarized synthetic aperture radar (SAR) that operated in concert with the Arecibo Observatory to collect bistatic radar data of the lunar nearside from 2012 to 2015. The purpose of this bistatic campaign was to characterize the radar scattering properties of the surface and near-surface, as a function of bistatic angle, for a variety of lunar terrains and search for a coherent backscatter opposition effect indicative of the presence of water ice. A variety of lunar terrain types were sampled over a range of incidence and bistatic angles; including mare, highland, pyroclastic, crater ejecta, and crater floor materials. Responses consistent with an opposition effect were observed for the ejecta of several Copernican-aged craters and the floor of the south-polar crater Cabeus. The responses of ejecta material varied by crater in a manner that suggests a relationship with crater age. The response for Cabeus was observed within the portion of its floor that is not in permanent shadow. The character of the response differs from that of crater ejecta and appears unique with respect to all other lunar terrains observed. Analysis of data for this region suggests that the unique nature of the response may indicate the presence of near-surface deposits of water ice.
Efficient engulfment of the intact cell corpse is a critical end point of apoptosis, required to prevent secondary necrosis and inflammation. The presentation of “eat-me” signals on the dying cell is ...an important part of this process of recognition and engulfment by professional phagocytes. Here, we present evidence that apoptotic cells secrete chemotactic factor(s) that stimulate the attraction of monocytic cells and primary macrophages. The activation of caspase-3 in the apoptotic cell was found to be required for the release of this chemotactic factor(s). The putative chemoattractant was identified as the phospholipid, lysophosphatidylcholine. Further analysis showed that lysophosphatidylcholine was released from apoptotic cells due to the caspase-3 mediated activation of the calcium-independent phospholipase A
2. These data suggest that in addition to eat-me signals, apoptotic cells display attraction signals to ensure the efficient removal of apoptotic cells and prevent postapoptotic necrosis.
We observed GRB 190114C (redshift
z
= 0.4245), the first gamma-ray burst (GRB) ever detected at TeV energies, at optical and near-infrared wavelengths with several ground-based telescopes and the
...Hubble
Space Telescope, with the primary goal of studying its underlying supernova, SN 2019jrj. The monitoring spanned the time interval between 1.3 and 370 days after the burst, in the observer frame. We find that the afterglow emission can be modelled with a forward shock propagating in a uniform medium modified by time-variable extinction along the line of sight. A jet break could be present after 7 rest-frame days, and accordingly the maximum luminosity of the underlying supernova (SN) ranges between that of stripped-envelope core-collapse SNe of intermediate luminosity and that of the luminous GRB-associated SN 2013dx. The observed spectral absorption lines of SN 2019jrj are not as broad as in classical GRB SNe and are instead more similar to those of less-luminous core-collapse SNe. Taking the broad-lined stripped-envelope core-collapse SN 2004aw as an analogue, we tentatively derive the basic physical properties of SN 2019jrj. We discuss the possibility that a fraction of the TeV emission of this source might have had a hadronic origin and estimate the expected high-energy neutrino detection level with IceCube.
Continuity or Change? Gonschorek, Gerrit J.; Schulze, Günther G.
ASEAN economic bulletin,
08/2018, Letnik:
35, Številka:
2
Journal Article
Recenzirano
This paper provides a systematic overview of the intergovernmental fiscal transfer system in Indonesia. It describes the size, allocation mechanism, and economic rationale (if any) of the different ...transfer schemes. Furthermore, the study points out major changes in the institutional set-up and in the relative magnitudes of the transfers effected by the Joko “Jokowi” Widodo administration. This allows us to assess the extent to which the current administration has shifted the policy stance on (fiscal) decentralization in the country. We critically evaluate the effectiveness and efficiency of the existing system, including the newly implemented reforms.
A natural field experiment is conducted on the determinants of consumer’s willingness to pay for “fair trade” (FT) products. In four treatments, subjects are offered different choices in connection ...with a coffee purchase, such as buying regular coffee or FT coffee at a premium, regular coffee with or without a premium, or donating directly or not donating. Depending on the treatment, the premium or direct donations are either given to FT or a well-known charity. A large part of the willingness to pay a premium for FT coffee over regular coffee is shown to be not related to the specific attributes of FT coffee but rather caused by the indirect transfer mechanism that FT uses, i.e., selling products at a premium which goes to the cause of FT.
The study examined the effects of feeding broiler breeder pullets hydrolyzed whole yeast (
HY
) from hatch to 22 wk of age (
WOA
). A total of 524-day-old Ross 708 pullets were placed in floor pens ...(∼24 birds/pen) for the starter (0–4 WOA) and grower (5–18 WOA) phases, then transferred to the egg production facility and redistributed to ∼20 birds/pen for the prelay phase (19–22 WOA). Two diets were allocated to pens (0–18 WOA;
n
= 11) and (19–22 WOA; n-12). The diets were a control corn and soybean meal diet formulated to meet specifications and control plus 0.05% HY (HY). Birds had ad libitum access to feed in the first week and daily feed allocation based on pen BW from 2 WOA. Birds had free access to water throughout the trial. Body weight (
BW
) and uniformity (BW CV) were monitored. Boosters for infectious bronchitis and New Castle disease vaccines were administered at 18 WOA, and samples of pullets bled for antibody titer 5-day later. One pullet/pen was randomly selected, weighed, bled for plasma biochemistry, and necropsied for organ weights, ceca digesta for short-chain fatty acids (
SCFA
), and leg bones morphometry. In the starter and grower phases, birds fed HY were lighter and gained less (
P
< 0.05) than control birds. However, there were no diet effects (
P
> 0.05) on growth, the BW prelay phase, or BW uniformity throughout the trial. There were no (
P
> 0.05) diet effects on breast, gastrointestinal, liver and bursa weights, serum antibody titers, plasma biochemistry, SCFA and bone attributes. However, pullets fed HY had heavier (
P
= 0.047) spleen and tended to have lower (
P
= 0.080) plasma concentrations of aspartate aminotransferase (
AST
) relative to control pullets. In conclusion, the parameters assessed showed no negative consequences of feeding HY to broiler breeder pullets. However, effects on the spleen and plasma AST may indicate modest modulation of immunity and metabolism. The impact of the provision of HY during broiler breeder pullet phase on reproductive performance and chick quality should be investigated.
Carbon exchange between the terrestrial biosphere and the atmosphere is
one of the key processes that need to be assessed in the context of the Kyoto
Protocol. Several studies suggest that the ...terrestrial biosphere
is gaining carbon, but these estimates are
obtained primarily by indirect methods, and the factors that control terrestrial
carbon exchange, its magnitude and primary locations, are under debate. Here
we present data of net ecosystem carbon exchange, collected between 1996 and
1998 from 15 European forests, which confirm that many European forest ecosystems
act as carbon sinks. The annual carbon balances range from an uptake of 6.6
tonnes of carbon per hectare per year to a release of nearly 1 t C ha
-1 yr-1, with a large variability between forests.
The data show a significant increase of carbon uptake with decreasing latitude,
whereas the gross primary production seems to be largely independent of latitude.
Our observations indicate that, in general, ecosystem respiration determines
net ecosystem carbon exchange. Also, for an accurate assessment of the carbon
balance in a particular forest ecosystem, remote sensing of the normalized
difference vegetation index or estimates based on forest inventories may not
be sufficient.
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