1,149 research outputs found
Water vole (Arvicola amphibius) abundance in grassland habitats of Glasgow
Water vole (Arvicola amphibius) populations have
undergone a serious decline throughout the UK, and
yet a stronghold of these small mammals is found in
the greater Easterhouse area of Glasgow. The water
voles in this location are mostly fossorial, living a
largely subterranean existence in grasslands, rather
than the more typical semi-aquatic lifestyle in
riparian habitats. In this study, we carried out
capture-mark-recapture surveys on water voles at
two sites: Cranhill Park and Tillycairn Drive. We
made a total of 62 captures including retraps, and the
resulting population estimates were 78 individuals
(95% confidence interval 41-197) for Cranhill Park
and 42 individuals (20-141) for Tillycairn Drive.
From these figures we estimated a population
density of water voles, which appeared to be higher
than other reports from the UK. Despite the
difficulties of sampling in urban environments that
resulted in relatively low capture rates, our data
suggest that the greater Easterhouse area of Glasgow
holds water voles at relatively high population
densities. These results will inform future
conservation in the City of Glasgow and surrounding
areas, as well as raise awareness of important water
vole populations in urban environments
Tectonic evolution of the Plymouth Bay Basin
A synthesis of offshore seismic data in the Plymouth Bay and Western Approaches, and onshore basement structures and mineralisation history has allowed new constraints to be placed on the structural evolution of the late Carboniferous- Triassic Plymouth Bay Basin. These data have been combined to produce a model for the late- and post- Variscan tectonics of the Plymouth Bay area. Additional controls on the timing and magnitude of Variscan uplift and late-Variscan low-angle extensional deformation onshore are used to infer a late Carboniferous age for the earliest basin fill. These sediments were accommodated in a northeast — south-west oriented basin formed during late-orogenic extension. A change in the orientation of the depocentre in the early Permian signalled a switch to a north-west — south-east, strike-slip dominated tectonic environment
Aerial Surveys for Cetaceans in the Former Akutan, Alaska, Whaling Grounds
Randomized aerial surveys were flown between 26 July and 26 August 1984 to search for cetaceans in two areas of southwestern Alaska: one on both Bering Sea and Pacific Ocean sides of the Aleutian Islands near the defunct Akutan shore-whaling station, which operated from 1912 through 1938, the other overlapping continental slope and shallow continental shelf waters between the Aleutians and the Pribilof Islands. ... Searches covered about 3940 nautical miles (nm), including some 2403 nm of random transects. Sightings were made of gray whales (10 sightings, 14 individuals), fin whales (3, 11), minke whales (1, 1), unidentified beaked whales (1, 6), Dall's porpoises (47, 131), killer whales (8, 26), and harbor porpoises (4, 7). A Fourier series model was used to estimate density of Dall's porpoises as 115 individuals (CV=0.263) per 1000 sq nm on the whaling grounds and 16.6 individuals (CV=0.0) per sq nm in the Bering Sea north of the whaling grounds. These estimates are comparable to those previously reported for the same general areas (97.2 animals per 1000 sq nm, SD=49.5). There were too few sightings of other cetaceans to permit calculation of meaningful density estimates. At least four species of great whales (blue, fin, humpback and sperm) were sufficiently abundant during the first four decades of this century to support significant whaling activities within about 100 sq nm of Akutan (more than 5300 whales were caught during 23 years of whaling, 1912-39). Although previous studies of the fisheries showed a downward trend in catch per unit of effort and an increase in distance traveled to take whales, whales were still being taken at relatively high rates (0.28-0.51 whales per gross catcher day) at the end of the fishery in 1939. Populations of fin, humpback, blue and sperm whales were probably significantly reduced by shore and pelagic whaling conducted widely in the North Pacific since 1939. ...Key words: aerial surveys, cetaceans, Bering Sea, North Pacific Ocean, historical whaling Des relevés aériens ont été effectués au hasard entre le 26 juillet et le 26 août 1984, afin de déterminer la présence de cétacés dans deux régions du Sud-Ouest de l'Alaska : l'une située des deux côtés des îles Aléoutiennes (du côté de la mer de Béring et du côté de l'océan Pacifique), près de ce qui fut jadis le port baleinier d'Akukan qui resta en opération de 1912 à 1939; l'autre couvrant à la fois les eaux du talus continental et celles, peu profondes, de la plate-forme continentale, entre les îles Aléoutiennes et les îles Pribilof. Les relevés furent effectuées à des altitudes comprises entre 150 et 245 m, d'un appareil d'observation Partenavia P68, muni d'un nez de plexiglas, permettant de voir dans l'axe de déplacement. Les recherches ont été effectuées sur environ 3940 milles nautiques (mn), y compris 2403 mn de recoupements au hasard. One a relevé la présence de baleines grises (10 relevés, 14 individus), de rorquals communs (3, 11), de petits rorquals (1, 1), de baleines à bec non identifiées (1, 6), de marsouins de Dall (47, 131), d'épaulards (8, 26) et de marsouins communs. On a utilisé un modèle en séries de Fourier pour déterminer approximativement la densité de marsouins de Dall à 115 individus (CV = 0.263) aux 1000 mn² dans les zones de pêche à la baleine, et à 16.6 individus (CV = 0.0) aux 1000 mn² dans la mer de Béring au nord des zones de pêche. Ces évaluations sont comparables à celles rapportées précédemment pour ces mêmes zones en général (97.2 animaux aux 1000 mn², DS = 49.5). Trop peu d'autres cétacés ont été aperçus pour justifier le calcul des densités approximatives. Durant les quarante premières années de ce siècle, il y avait au moins quatre espèces de grandes baleines (rorquals bleus, rorquals communs, rorquals à bosse et cachalots) en quantité suffisante pour alimenter une industrie baleinière dans un rayon d'environ 100 mn d'Akutan. (Plus de 5300 baleines furent pêchées durant les 23 années que dura la pêche à la baleine, de 1912 à 1939). Bien que des études précédentes sur la pêche aient montré une tendance à la baisse du nombre de prises par rapport au nombre d'unités d'effort et une augmentation de la distance à parcourir pour capturer les baleines, celles-ci étaient capturées à un taux relativement élevé (de 0.28 à 0.51 baleine par unité d'effort brute par jour) à la fin de la pêche en 1939. Les populations de rorquals communs, de rorquals à bosse, de rorquals bleus et de cachalots ont probablement été réduites de façon significative par le pêche côtière et la pêche pélagique, qui ont été pratiquées à grande échelle dans le Pacifique Nord depuis 1939. Le petit nombre de cétacés aperçus durant les présents relevés porte à croire que les populations dans les zones de pêche et dans leur vicinité, restent peu élevées en raison de ces activités. Mots clés : relevé aérien, cétacés, mer de Béring, Pacifique Nord, ancienne pêche à la balein
Evidence from Cameroon reveals differences in the genetic structure and histories of chimpanzee populations
The history of the genus Pan is a topic of enduring interest. Chimpanzees (Pan troglodytes) are often divided into subspecies, but the population structure and genetic history of chimpanzees across Africa remain unclear. Some population genetics studies have led to speculation that, until recently, this species constituted a single population with ongoing gene flow across its range, which resulted in a continuous gradient of allele frequencies. Chimpanzees, designated here as P. t. ellioti, occupy the Gulf of Guinea region that spans southern Nigeria and western Cameroon at the center of the distribution of this species. Remarkably, few studies have included individuals from this region, hindering the examination of chimpanzee population structure across Africa. Here, we analyzed microsatellite genotypes of 94 chimpanzees, including 32 designated as P. t. ellioti. We find that chimpanzees fall into three major populations: (i) Upper Guinea in western Africa (P. t. verus); (ii) the Gulf of Guinea region (P. t. ellioti); and (iii) equatorial Africa (P. t. troglodytes and P. t. schweinfurthii). Importantly, the Gulf of Guinea population is significantly different genetically from the others, sharing a last common ancestor with the populations in Upper Guinea similar to 0.46 million years ago (mya) and equatorial Africa similar to 0.32 mya. Equatorial chimpanzees are subdivided into up to three populations occupying southern Cameroon, central Africa, and eastern Africa, which may have constituted a single population until similar to 0.10-0.11 mya. Finally, occasional hybridization may be occurring between the Gulf of Guinea and southern Cameroon population
Dual Vortex Theory of Strongly Interacting Electrons: Non-Fermi Liquid to the (Hard) Core
As discovered in the quantum Hall effect, a very effective way for
strongly-repulsive electrons to minimize their potential energy is to aquire
non-zero relative angular momentum. We pursue this mechanism for interacting
two-dimensional electrons in zero magnetic field, by employing a representation
of the electrons as composite bosons interacting with a Chern-Simons gauge
field. This enables us to construct a dual description in which the fundamental
constituents are vortices in the auxiliary boson fields. The resulting
formalism embraces a cornucopia of possible phases. Remarkably,
superconductivity is a generic feature, while the Fermi liquid is not --
prompting us to conjecture that such a state may not be possible when the
interactions are sufficiently strong. Many aspects of our earlier discussions
of the nodal liquid and spin-charge separation find surprising incarnations in
this new framework.Comment: Modified dicussion of the hard-core model, correcting several
mistake
Magnetic ordering of Mn sublattice, dense Kondo lattice behavior of Ce in (RPd3)8Mn (R = La, Ce)
We have synthesized two new interstitial compounds (RPd3)8Mn (R = La and Ce).
The Mn ions present in "dilute" concentration of just 3 molar percent form a
sublattice with an unusually large Mn-Mn near neighbor distance of ~ 85 nm.
While the existence of (RPd3)8M (where M is a p-block element) is already
documented in the literature, the present work reports for the first time the
formation of this phase with M being a 3d element. In (LaPd3)8Mn, the Mn
sub-lattice orders antiferromagnetically as inferred from the peaks in
low-field magnetization at 48 K and 23 K. The latter peak progressively shifts
towards lower temperatures in increasing magnetic field and disappears below
1.8 K in a field of ~ 8 kOe. On the other hand in (CePd3)8Mn the Mn sublattice
undergoes a ferromagnetic transition around 35 K. The Ce ions form a dense
Kondo-lattice and are in a paramagnetic state at least down to 1.5 K. A
strongly correlated electronic ground state arising from Kondo effect is
inferred from the large extrapolated value of C/T = 275 mJ/Ce-mol K^2 at T = 0
K. In contrast, the interstitial alloys RPd3Mnx (x = 0.03 and 0.06), also
synthesized for the first time, have a spin glass ground state due to the
random distribution of the Mn ions over the available "1b" sites in the parent
RPd3 crystal lattice.Comment: 18 figures and 20 pages of text documen
Screening for atrial fibrillation within a South Asian community setting using single-lead ECG
Timely detection and treatment of AF is amongst the Government’s cardiovascular priorities. Several initiatives have demonstrated the potential of AF detection using single-lead electrocardiogram (SLECG) technology in primary care settings, such as general practitioners’ (GP) surgeries. Unfortunately, some AF patients, including those from ethnic minorities, may not routinely engage with main-stream healthcare and may go undetected. Compared to White British, South Asians have a higher prevalence of cardiovascular risk factors, however fewer are diagnosed with AF. This study aimed to ascertain the feasibility of opportunistic AF screening within a South Asian community delivered by supervised pharmacy undergraduates using SL-ECG devices
Shifting sows: longitudinal changes in the periparturient faecal microbiota of primiparous and multiparous sows
Knowledge of periparturient longitudinal changes in sow microbiota composition is necessary to fully understand her role in the development of the piglet microbiota, but also to improve gut health and performance of the sow in lactation. Primiparous sows face the challenge of partitioning nutrients to support maternal growth in addition to supporting foetal growth and the demands of lactation. Additional metabolic stress present during the periparturient period may induce changes in the microbiota profile between primiparous and multiparous sows. Using 16S rRNA gene sequencing, the study aimed to characterise the longitudinal changes in the periparturient microbiota and identify differences within the sow microbiota profile associated with parity. Faecal samples from primiparous (n = 13) and multiparous (n = 16) sows were collected at four different time points (day - 6, - 1, 3 and 8) in relation to farrowing (day 0). Microbiota richness was lowest on day 3 and - 1 of the periparturient period (P < 0.05). Microbiota community composition, assessed by weighted and unweighted UniFrac distances, demonstrated longitudinal changes, with day 3 samples clustering away from all other sampling time points (P < 0.05). The relative abundance of several genera segregated gestation from lactation samples including Roseburia, Prevotella 1, Prevotella 2, Christensenellaceae R-7 group, Ruminococcaceae UCG-002 and Ruminococcaceae UCG-010 (P < 0.01). Furthermore, day 3 was characterised by a significant increase in the relative abundance of Escherichia/Shigella, Fusobacterium and Bacteroides, and a decrease in Alloprevotella, Prevotellaceae UCG-003 and Ruminococcus 1 (P < 0.001). Primiparous sows had overall lower periparturient microbiota diversity (P < 0.01) and there was a significant interaction between parity and sampling time point, with primiparous sows having lower microbiota richness on day - 6 (P < 0.001). There was a significant interaction between sow parity and sampling time point on microbiota composition on day - 6 and - 1 (unweighted UniFrac distances;  ≤ 0.01) and day 8 (weighted and unweighted UniFrac distances; P < 0.05). Whilst no significant interactions between sow parity and sampling day were observed for genera relative abundances, multiparous sows had a significantly higher relative abundance of Bacteroidetes dgA-11 gut group and Prevotellaceae UCG-004 (P < 0.01). This study demonstrates that the sow microbiota undergoes longitudinal changes, which are collectively related to periparturient changes in the sow environment, diet and physiological changes to support foetal growth, delivery and the onset of lactation, but also sow parity
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Recent progress with the DNA repair mutants of Chinese hamster ovary cells
Repair deficient mutants of Chinese hamster ovary (CHO) cells are being used to identify human genes that correct the repair defects and to study mechanisms of DNA repair and mutagenesis. Five independent tertiary DNA transformants were obtained from the EM9 mutant. In these clones a human DNA sequence was identified that correlated with the resistance of the cells to CldUrd. After Eco RI digestion, Southern transfer, and hybridization of transformant DNAs with the BLUR-8 Alu family sequence, a common fragment of 25 to 30 kb was present. 37 refs., 4 figs., 3 tabs
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