Queen's University Belfast

About: Queen's University Belfast is a education organization based out in Belfast, United Kingdom. It is known for research contribution in the topics: Population & Context (language use). The organization has 25457 authors who have published 55463 publications receiving 1751346 citations. The organization is also known as: Queen's College, Belfast & Queen's College.

Climate-related changes in peatland carbon accumulation during the last millennium

Abstract: Peatlands are a major terrestrial carbon store and a persistent natural carbon sink during the Holocene, but there is considerable uncertainty over the fate of peatland carbon in a changing climate. It is generally assumed that higher temperatures will increase peat decay, causing a positive feedback to climate warming and contributing to the global positive carbon cycle feedback. Here we use a new extensive database of peat profiles across northern high latitudes to examine spatial and temporal patterns of carbon accumulation over the past millennium. Opposite to expectations, our results indicate a small negative carbon cycle feedback from past changes in the long-term accumulation rates of northern peatlands. Total carbon accumulated over the last 1000 yr is linearly related to contemporary growing season length and photosynthetically active radiation, suggesting that variability in net primary productivity is more important than decomposition in determining long-term carbon accumulation. Furthermore, northern peatland carbon sequestration rate declined over the climate transition from the Medieval Climate Anomaly (MCA) to the Little Ice Age (LIA), probably because of lower LIA temperatures combined with increased cloudiness suppressing net primary productivity. Other factors including changing moisture status, peatland distribution, fire, nitrogen deposition, permafrost thaw and methane emissions will also influence future peatland carbon cycle feedbacks, but our data suggest that the carbon sequestration rate could increase over many areas of northern peatlands in a warmer future.

Hydrogen-poor superluminous supernovae and long-duration gamma-ray bursts have similar host galaxies

Abstract: We present optical spectroscopy and optical/near-IR photometry of 31 host galaxies of hydrogen-poor superluminous supernovae (SLSNe), including 15 events from the Pan-STARRS1 Medium Deep Survey. Our sample spans the redshift range 0.1 z 1.6, and is the first comprehensive host galaxy study of this specific subclass of cosmic explosions. Combining the multi-band photometry and emission-line measurements, we determine the luminosities, stellar masses, star formation rates, and metallicities. We find that, as a whole, the hosts of SLSNe are a low-luminosity (MB ≈ –17.3 mag), low stellar mass (M * ≈ 2 × 108 M ☉) population, with a high median specific star formation rate (sSFR ≈ 2 Gyr–1). The median metallicity of our spectroscopic sample is low, 12 + log (O/H) ≈ 8.35 ≈ 0.45 Z ☉, although at least one host galaxy has solar metallicity. The host galaxies of H-poor SLSNe are statistically distinct from the hosts of GOODS core-collapse SNe (which cover a similar redshift range), but resemble the host galaxies of long-duration gamma-ray bursts (LGRBs) in terms of stellar mass, SFR, sSFR, and metallicity. This result indicates that the environmental causes leading to massive stars forming either SLSNe or LGRBs are similar, and in particular that SLSNe are more effectively formed in low metallicity environments. We speculate that the key ingredient is large core angular momentum, leading to a rapidly spinning magnetar in SLSNe and an accreting black hole in LGRBs.

Molecular and Biological Characterization of Deformed Wing Virus of Honeybees (Apis mellifera L.)

Abstract: Deformed wing virus (DWV) of honeybees (Apis mellifera) is closely associated with characteristic wing deformities, abdominal bloating, paralysis, and rapid mortality of emerging adult bees. The virus was purified from diseased insects, and its genome was cloned and sequenced. The genomic RNA of DWV is 10,140 nucleotides in length and contains a single large open reading frame encoding a 328-kDa polyprotein. The coding sequence is flanked by a 1,144-nucleotide 5 nontranslated leader sequence and a 317-nucleotide 3 nontranslated region, followed by a poly(A) tail. The three major structural proteins, VP1 (44 kDa), VP2 (32 kDa), and VP3 (28 kDa), were identified, and their genes were mapped to the N-terminal section of the polyprotein. The C-terminal part of the polyprotein contains sequence motifs typical of well-characterized picornavirus nonstructural proteins: an RNA helicase, a chymotrypsin-like 3C protease, and an RNA-dependent RNA polymerase. The genome organization, capsid morphology, and sequence comparison data indicate that DWV is a member of the recently established genus Iflavirus. Deformed wing virus (DWV) is the one of the main viruses associated with the collapse of honeybee (Apis mellifera L.) colonies due to infestation with the ectoparasitic mite Varroa destructor (4, 8, 12). The virus was first isolated from a sample of symptomatic honeybees from Japan in the early 1980s and is currently distributed worldwide, wherever varroa mites are found (2, 18). A recent survey of adult bee populations detected DWV in over 90% of French apiaries (66) and in 100% of mite samples. The incidence was slightly reduced when pupal samples were analyzed, especially in the spring (66). DWV has also been detected by serology in the dwarf bee A. florae Fabr. (F. R. Hunter-Fujita, M. S. Mossadegh, and B. V. Ball, Abstr. 36th “Apimondia” Int. Apic. Congr., abstr. 230, 1999) and in the Asian honeybee A. cerana Fabr. (2) and by reverse transcriptase (RT) PCR in bumblebees (29). It is serologically related to Egypt bee virus (8, 9, 13), first isolated in 1977 from infected adults from Egypt (10). Typical symptoms of deformed wing disease are vestigial and crumpled wings, bloated abdomens, paralysis, and a severely shortened adult life span for emerging worker and drone bees (44). For a long time it was believed that these symptoms were due to the feeding activity of the mites (23, 42, 72) until it was shown that, in diseased colonies, deformed bees could emerge from cells not parasitized by varroa mites (49, 55) and that the symptoms

British Thoracic Society Guideline for bronchiectasis in adults

Abstract: ### How should the diagnosis of bronchiectasis be determined? #### Recommendations – Imaging #### Good practice points CT imaging protocol CT features of bronchiectasis General ### In whom should the diagnosis of bronchiectasis be suspected? #### Recommendations