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.

Threats and knowledge gaps for ecosystem services provided by kelp forests: a northeast Atlantic perspective.

Abstract: Kelp forests along temperate and polar coastlines represent some of most diverse and productive habitats on the Earth. Here, we synthesize information from >60 years of research on the structure and functioning of kelp forest habitats in European waters, with particular emphasis on the coasts of UK and Ireland, which represents an important biogeographic transition zone that is subjected to multiple threats and stressors. We collated existing data on kelp distribution and abundance and reanalyzed these data to describe the structure of kelp forests along a spatial gradient spanning more than 10° of latitude. We then examined ecological goods and services provided by kelp forests, including elevated secondary production, nutrient cycling, energy capture and flow, coastal defense, direct applications, and biodiversity repositories, before discussing current and future threats posed to kelp forests and identifying key knowledge gaps. Recent evidence unequivocally demonstrates that the structure of kelp forests in the NE Atlantic is changing in response to climate- and non-climate-related stressors, which will have major implications for the structure and functioning of coastal ecosystems. However, kelp-dominated habitats along much of the NE Atlantic coastline have been chronically understudied over recent decades in comparison with other regions such as Australasia and North America. The paucity of field-based research currently impedes our ability to conserve and manage these important ecosystems. Targeted observational and experimental research conducted over large spatial and temporal scales is urgently needed to address these knowledge gaps.

Attractive intramolecular edge-to-face aromatic interactions in flexible organic molecules.

Abstract: Recent X-ray crystallographic and NMR evidence indicates that relatively weak intramolecular edge-to-face interactions between aromatic rings can affect or determine the conformation of organic molecules in the solid state and in solution. Experimental estimates indicate that these interactions are energetically attractive by ca. 1.5 kcal mol-1 but disfavored in solution by entropic factors due to the restricted internal mobility. Hence, these interactions are more manifest at low temperature in solution or in crystal structures where conformational entropy effects are negligible.

Perceptions of aging across 26 cultures and their culture-level associates.

Abstract: College students (N=3,435) in 26 cultures reported their perceptions of age-related changes in physical, cognitive, and socioemotional areas of functioning and rated societal views of aging within their culture. There was widespread cross-cultural consensus regarding the expected direction of aging trajectories with (a) perceived declines in societal views of aging, physical attractiveness, the ability to perform everyday tasks, and new learning; (b) perceived increases in wisdom, knowledge, and received respect; and (c) perceived stability in family authority and life satisfaction. Cross-cultural variations in aging perceptions were associated with culture-level indicators of population aging, education levels, values, and national character stereotypes. These associations were stronger for societal views on aging and perceptions of socioemotional changes than for perceptions of physical and cognitive changes. A consideration of culture-level variables also suggested that previously reported differences in aging perceptions between Asian and Western countries may be related to differences in population structure.

Tight junctional abnormality in multiple sclerosis white matter affects all calibres of vessel and is associated with blood-brain barrier leakage and active demyelination.

Abstract: Blood-brain barrier (BBB) hyperpermeability in multiple sclerosis (MS) is associated with lesion pathogenesis and has been linked to pathology in microvascular tight junctions (TJs). This study quantifies the uneven distribution of TJ pathology and its association with BBB leakage. Frozen sections from plaque and normal-appearing white matter (NAWM) in 14 cases were studied together with white matter from six neurological and five normal controls. Using single and double immunofluorescence and confocal microscopy, the TJ-associated protein zonula occludens-1 (ZO-1) was examined across lesion types and tissue categories, and in relation to fibrinogen leakage. Confocal image data sets were analysed for 2198 MS and 1062 control vessels. Significant differences in the incidence of TJ abnormalities were detected between the different lesion types in MS and between MS and control white matter. These were frequent in oil-red O (ORO)(+) active plaques, affecting 42% of vessel segments, but less frequent in ORO(-) inactive plaques (23%), NAWM (13%), and normal (3.7%) and neurological controls (8%). A similar pattern was found irrespective of the vessel size, supporting a causal role for diffusible inflammatory mediators. In both NAWM and inactive lesions, dual labelling showed that vessels with the most TJ abnormality also showed most fibrinogen leakage. This was even more pronounced in active lesions, where 41% of vessels in the highest grade for TJ alteration showed severe leakage. It is concluded that disruption of TJs in MS, affecting both paracellular and transcellular paths, contributes to BBB leakage. TJ abnormality and BBB leakage in inactive lesions suggests either failure of TJ repair or a continuing pathological process. In NAWM, it suggests either pre-lesional change or secondary damage. Clinically inapparent TJ pathology has prognostic implications and should be considered when planning disease-modifying therapy.

Measuring the contributions of nitrification and denitrification to the flux of nitrous oxide from soil

Abstract: The flux of N2O from soil can be due to nitrification or denitrification. Since aerobic and anaerobic microsites can develop within the same soil aggregate, nitrification and denitrification could be occurring at the same time. The contribution of nitrification and denitrification to the flux of N2O can be studied by differentially 15N-labelling the NO3− and NH4+ pools in soils. By periodically measuring and comparing the enrichments of the N2O, NH4+ and NO3− pools, the relative importance of the two processes can be quantified. The conclusions are based on calculations which assume that the 15N atom fractions of the nitrification and denitrification pools remain uniform throughout the incubation. The initial uniformity of the denitrification pool was tested by adding a nitrification-inhibitor, C2H2, at time zero and examining the 15N-distribution of the accumulated N2O at subsequent times. If the 15N distribution in the N2O is random it originated from one source, but ifthe 15N distribution is non-random the N2O originated from two or more sources. Two soil incubation experiments were conducted. In the first experiment fresh sieved soil was incubated over 10 days at 40, 50 and 60% moisture content with (NH2)2CO (70 μmol N g−1) and KNO3 (14 μmol N g−1) differentially labelled at 10 atom% excess 15N. The headspace was sampled daily for N2O before being refreshed with normal air. Every second day the sizes and enrichments of the NH4+ and NO3− pools were determined by destructive sampling. In the second experiment the assumption that the method of addition of label created only one denitrifying pool was tested by blocking nitrification with C2H2 (10 kPa). Fresh soil was incubated for three incubation times (6, 12 and 24 h) with differentially-labelled NH4NO3 (1.46 μmol N g−1) enriched to 20 atom% excess 15N, with glucose (42 and 83 μmol C g−1) to promote denitrification. In the first experiment the enrichment of the N2O did not match either the enrichment of the NH4+ or NO3− pools, showing that N2O was being produced by nitrification and denitrification. Quantification of the fractional contributions of nitrification and denitrification showed that denitrification was the dominant process in the first 2 days, but then nitrification became the dominant process for the rest of the incubation. More N2O was produced at 50 and 60% moisture than at 40% moisture, but the relative contributions of the two processes were the same at all moisture contents. Nitrification was responsible for 70% of the N2O flux. In the second experiment examination of the isotopic composition of the N2O showed that the 15N atoms were randomly distributed throughout the molecules. The N2O therefore orginated from one denitrifying pool, confirming that our method of addition of label initially created one NO3− pool for denitrification. There seems to be no feasible way at present to test the uniformity of the nitrification pool.