754 research outputs found
Millimeter interferometer observations of the magnetar 4U 0142+61
The Anomalous X‐ray Pulsar 4U 0142+61 is the only neutron star where it is believed that one of the long searched‐for ‘fallback’ disks has been detected in the mid‐IR by Wang et al. [1] using Spitzer. Such a disk originates from material falling back to the NS after the supernova. We search for cold circumstellar material in the 90 GHz continuum using the Plateau de Bure Interferometer. No millimeter flux is detected at the position of 4U 0142+61, the upper flux limit is 150 μJy corresponding to the 3σ noise rms level. The re‐processed Spitzer MIPS 24μm data presented previously by Wang et al. [2] show some indication of flux enhancement at the position of the neutron star, albeit below the 3σ statistical significance limit. At far infrared wavelengths the source flux densities are probably below the Herschel confusion limits
Integrated stress response of Escherichia coli to methylglyoxal : transcriptional readthrough from the nemRA operon enhances protection through increased expression of glyoxalase I
© 2013 The Authors. Molecular Microbiology published by John Wiley & Sons Ltd.Peer reviewedPublisher PD
Abspaltung ortho-ständiger Substituenten aus ionisierten Phenyl-2-propanonen nach Elektronenstoßaktivierung
Die Molekülionen der Phenyl-2-propanone 2a-4a verlieren positionsspezifisch
o-ständige Cl -, Br - bzw. I -Atome unter Bildung von (M-Hal')+-
Ionen (m/z 133) hoher Intensität (70/12 eV; 1. und 2. FFR) und identischer
Struktur (MIKE-CAD-Spektren). Die Fragmentionen bei m/z 133 aus o-
Chlorphenyl-2-propanon (2a) und 2,2-Dimethyl-2,3-dihydro[fc]furan (11)
sind von ähnlicher, aber nicht identischer Struktur. Die stoßaktivierten (2.
FFR) (M-Br*)+-Ionen aus o-Bromphenyl-2-propanon (3a) und 1-Brom-lphenyl-
2-propanon (12) liefern praktisch deckungsgleiche Spektren. Die
Hauptreaktion der (M-Hal')+-Ionen aus 2a-4a ist die Abspaltung von CO,
das ausschließlich das C-Atom der Carbonylgruppe enthält (13C-Markierung).
Der mechanistische Verlauf der Reaktionsfolge wird diskutiert
(Abb. 5 und 8).
In the gas phase, the phenyl-2-propanone molecules 2a-4a lose upon electron
impact chloro-, bromo-, and iodo-radicals specifically at the orthoposition
of the phenyl group giving rise to strong (M-Hal')+-ions (70/12
eV; 1st and 2nd FFR) of identical structure as confirmed by their MIKECAD-
spectra. The daughter ions at m/z 133 from o-chlorophenyl-2-propanone
(2a) and 2,2-dimethyl-2,3-dihydro[b]furane (11) are structurally
similar but not identical (similarity index 99.8). The collisionally activated
(2nd FFR) (M-Br')+-ions from o-bromophenyl-2-propanone (3a) and 1-
bromo-1-phenyl-2-propanone (12) produce virtually congruent spectra.
The most important subsequent fragmentation of the (M-Hal')+-ions from
2a-4a is the loss of CO which incorporates the C-atom of the carbonyl
group exclusively (13C labelling). Mechanistic aspects of the fragmentation
sequences are discussed (Figs. 5 and 8)
X-Ray and Infrared Enhancement of Anomalous X-ray Pulsar 1E 2259+58
The long term (~1.5 years) X-ray enhancement and the accompanying infrared
enhancement light curves of the anomalous X-ray pulsar 1E 2259+58 following the
major bursting epoch can be accounted for by the relaxation of a fall back disk
that has been pushed back by a gamma-ray flare. The required burst energy
estimated from the results of our model fits is low enough for such a burst to
have remained below the detection limits. We find that an irradiated disk model
with a low irradiation efficiency is in good agreement with both X-ray and
infrared data. Non-irradiated disk models also give a good fit to the X-ray
light curve, but are not consistent with the infrared data for the first week
of the enhancement.Comment: 17 pages, 3 figures, accepted for publication in Ap
Lender forbearance
We use a threshold-based design to study ex post discretion in lenders’ contractual enforcement of covenant violations. At preset thresholds, lenders enforce contractual breaches only infrequently, but this enforcement is associated with material consequences, e.g., fees and renegotiations. Enforcement varies significantly over time and peaks when credit conditions are tightest, indicating that enforcement is procyclical. Costly coordination reduces enforcement: syndicates with ex ante restrictive voting requirements enforce at lower rates. Consistent with theories of lender competition and implicit contracting, enforcement rates are lower for borrowers with access to alternative sources of financing and well-reputed lead arrangers
Dim Isolated Neutron Stars, Cooling and Energy Dissipation
The cooling and reheating histories of dim isolated neutron stars(DINs) are
discussed. Energy dissipation due to dipole spindown with ordinary and magnetar
fields, and due to torques from a fallback disk are considered as alternative
sources of reheating which would set the temperature of the neutron star after
the initial cooling era. Cooling or thermal ages are related to the numbers and
formation rates of the DINs and therefore to their relations with other
isolated neutron star populations. Interaction with a fallback disk, higher
multipole fields and activity of the neutron star are briefly discussed.Comment: To appear in Astrophysics and Space Science, in the proceedings of
the conference "Isolated Neutron Stars: from the Interior to the Surface",
London, April 2006; eds. D. Page, R. Turolla and S. Zane. Revised version:
with minor change and typos correcte
Miokarditis vezan uz slinavku i šap u sisajuće teladi.
Foot-and-mouth disease (FMD) can lead to myocarditis in young animals, but the age distributions of calves with myocarditis have not been described, nor the biochemical profile in these calves. In an area endemic with foot-and-mouth disease, calves less than 6 months of age in infected farms were examined for clinical lesions and abnormalities in respiratory rate, heart rate and heart rhythm. In total, 53 calves were identified to be suspected of having foot-and-mouth disease infection. In 6 calves myocarditis was suspected based on tachypnea, tachycardia and gallop rhythm. In these 6 calves, cardiac troponin-I (cTnI) and aspartate aminotransferase (AST) were significantly higher (P<0.0001), but the levels of Creatinine Kinase MB (CK-MB) and Lactate dehydrogenase (LDH) were not. These 6 calves died within 2 days and histopathology confirmed myocarditis. All calves with myocarditis were younger than 2-months old, suggesting that myocarditis caused by FMD is mainly found in very young suckling calves.Slinavka i šap može dovesti do miokarditisa u mladih životinja. Dosada nije opisana dobna raspodjela miokarditisa ni biokemijski profil u teladi oboljele od slinavke i šapa. U jednom području gdje se slinavka i šap javlja endemijski, telad mlađa od šest mjeseci bila je na zaraženim farmama klinički pretražena posebice na poremećaje u frekvenciji bila, disanja i srčanog ritma. Ukupno su 53 teleta bila sumnjiva na slinavku i šap. Sumnja na miokarditis postavljena je u šest teladi i to na osnovi tahipneje, tahikardije i galopirajućeg ritma. U te su teladi razine srčanog troponina-I (cTnI) i aspartat-aminotransferaze (AST) bile značajno više (P<0,0001), dok razine kreatinin-kinaze MB (CK-MB) i laktat-dehidrogenaze (LDH) nisu. Tih šest teleta uginulo je unutar dva dana te je u njih miokarditis bio potvrđen patohistološki. Sva telad s miokarditisom bila je mlađa od dva mjeseca, što upućuje na zaključak da se miokarditis uzrokovan virusom slinavke i šapa pretežito javlja u sisajuće teladi najranije dobi
3-Benzyl-5-butyl-1,3,5-thiadiazinane-2-thione
In the title compound, C14H20N2S2, the 1,3,5-thiadiazinane-2-thione ring adopts an envelope conformation. The S=C bond length is 1.6776 (15) Å, whereas the S—C bond lengths are 1.7470 (15) and 1.8479 (17) Å. The intramolecular C—H⋯S hydrogen bond between the thione and the benzyl units along with the C—H⋯π interaction between the butyl group and the centroid of the benzene ring may be effective in stabilizing the molecule
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