The evolution of the holocene wetland landscape of the Humberhead Levels from a fossil insect perspective.

Palaeoentomological investigations have been carried out on a series of profiles and contexts in the Humberhead Levels (eastern England), principally from the raised mires of Thome and Hatfield Moors, and from floodplains of the rivers Tome and Idle at Rossington, near Doncaster, and Misterton Carr, Nottinghamshire. Research has attempted to elucidate the effect of peatland development on the composition of the insect fauna, with particular emphasis on Hatfield Moors, as well as investigate the transition from Quercus-Pinus forest to mire and the faunal characteristics of those forests. The study of the fossil insects, together with other palaeoecological evidence, has enabled the genesis and development of these mires to be reconstructed in some detail. However, the palaeoenvironmental record from Thome and Hatfield Moors indicate significant differences in initiation, development and rate of growth between the two sites. The research highlights the valuable palaeoecological record of the peat deposits on Hatfield Moors, which have long been ignored in favour of Thome Moors. In particular, research highlights the importance of Pirns woodland and wet heath, components reflected in the invertebrates today. The study of the floodplain deposits have enabled the research from the Moors to be placed within a regional context. Faunal successions highlight the transition from Urwald (undisturbed woodland), c. 4000 cal BC, to a largely cleared landscape by the late Roman period (c. 400 cal AD). The research has highlighted the nature and diversity of Holocene Urwald and illustrates the important habitat provided by abundant dead wood within these systems. The fossil record emphasises the contraction in range of many elements of the British Coleopterous fauna, both at a regional and national level. A total of eleven extirpated Coleóptera have been recovered, including two species of beetle previously unknown in the British Isles. The significance of these and other Urwaldrelikt species is discussed in relation to the human fragmentation of forest habitats and the decline of Pirns sylvestris L. The importance of fire as a natural agent within the landscape, within coniferous woodland and Pinus-mire and heath systems is highlighted. The dependence of some pinicolous taxa on fire habitats suggests that the decline of this habitat has had a detrimental impact on the biogeography of some species. The role of climate as a limiting factor in distribution of thermophilous species is also discussed

Simulations of protostellar collapse using multigroup radiation hydrodynamics. I. The first collapse

Radiative transfer plays a major role in the process of star formation. Many simulations of gravitational collapse of a cold gas cloud followed by the formation of a protostellar core use a grey treatment of radiative transfer coupled to the hydrodynamics. However, dust opacities which dominate extinction show large variations as a function of frequency. In this paper, we used frequency-dependent radiative transfer to investigate the influence of the opacity variations on the properties of Larson's first core. We used a multigroup M1 moment model in a 1D radiation hydrodynamics code to simulate the spherically symmetric collapse of a 1 solar mass cloud core. Monochromatic dust opacities for five different temperature ranges were used to compute Planck and Rosseland means inside each frequency group. The results are very consistent with previous studies and only small differences were observed between the grey and multigroup simulations. For a same central density, the multigroup simulations tend to produce first cores with a slightly higher radius and central temperature. We also performed simulations of the collapse of a 10 and 0.1 solar mass cloud, which showed the properties of the first core to be independent of the initial cloud mass, with again no major differences between grey and multigroup models. For Larson's first collapse, where temperatures remain below 2000 K, the vast majority of the radiation energy lies in the IR regime and the system is optically thick. In this regime, the grey approximation does a good job reproducing the correct opacities, as long as there are no large opacity variations on scales much smaller than the width of the Planck function. The multigroup method is however expected to yield more important differences in the later stages of the collapse when high energy (UV and X-ray) radiation is present and matter and radiation are strongly decoupled.Comment: 9 pages, 5 figures, accepted for publication in A&

Outbreak of gastroenteritis caused by Yersinia pestis in Afghanistan.

Plague, which is most often caused by the bite of Yersinia pestis-infected fleas, is a rapidly progressing, serious disease that can be fatal without prompt antibiotic treatment. In late December 2007, an outbreak of acute gastroenteritis occurred in Nimroz Province of southern Afghanistan. Of the 83 probable cases of illness, 17 died (case fatality 20·5%). Being a case was associated with consumption or handling of camel meat (adjusted odds ratio 4·4, 95% confidence interval 2·2-8·8, P<0·001). Molecular testing of patient clinical samples and of tissue from the camel using PCR/electrospray ionization-mass spectrometry revealed DNA signatures consistent with Yersinia pestis. Confirmatory testing using real-time PCR and immunological seroconversion of one of the patients confirmed that the outbreak was caused by plague, with a rare gastrointestinal presentation. The study highlights the challenges of identifying infectious agents in low-resource settings; it is the first reported occurrence of plague in Afghanistan

Carbon-enhanced stars with short orbital and spin periods

Many characteristics of dwarf carbon stars are broadly consistent with a binary origin, including mass transfer from an evolved companion. While the population overall appears to have old-disc or halo kinematics, roughly 2 per cent of these stars exhibit Hα emission, which in low-mass main-sequence stars is generally associated with rotation and relative youth. Its presence in an older population therefore suggests either irradiation or spin-up. This study presents time-series analyses of photometric and radial-velocity data for seven dwarf carbon stars with Hα emission. All are shown to have photometric periods in the range 0.2–5.2 d, and orbital periods of similar length, consistent with tidal synchronisation. It is hypothesised that dwarf carbon stars with emission lines are the result of close-binary evolution, indicating that low-mass, metal-weak or metal-poor stars can accrete substantial material prior to entering a common-envelope phase

Foundation scour as a geohazard

Carrying out a hazard assessment for offshore structures can entail the consideration of a number of different factors. Scour hazard assessments are routinely undertaken, and scour development at offshore structures should be considered a time-varying process. However, scour may take place within a morphologically dynamic environment, the combination of which will impact on the soil–structure–fluid response. This paper presents the analysis of an unique data set that shows the partial collapse of a scour hole at a large monopile foundation within a morphologically active site. The collapse suggests a slope failure mechanism, resulting in the movement of around 450 m3 of material within a period of about 75 min. The paper analyzes the processes involved regarding formation and development of the collapse

Genetic counseling as preventive intervention: Toward individual specification of transgenerational autism risk

BACKGROUND: Although autism spectrum disorders (ASD) are among the most heritable of all neuropsychiatric syndromes, most affected children are born to unaffected parents. Recently, we reported an average increase of 3-5% over general population risk of ASD among offspring of adults who have first-degree relatives with ASD in a large epidemiologic family sample. A next essential step is to investigate whether there are measurable characteristics of individual parents placing them at higher or lower recurrence risk, as this information could allow more personalized genetic counseling. METHODS: We assembled what is to our knowledge the largest collection of data on the ability of four measurable characteristics of unaffected prospective parents to specify risk for autism among their offspring: (1) sub clinical autistic trait burden, (2) parental history of a sibling with ASD, (3) transmitted autosomal molecular genetic abnormalities, and (4) parental age. Leveraging phenotypic and genetic data in curated family cohorts, we evaluate the respective associations between these factors and child outcome when autism is present in the family in the parental generation. RESULTS: All four characteristics were associated with elevation in offspring risk; however, the magnitude of their predictive power-with the exception of isolated rare inherited pathogenic variants -does not yet reach a threshold that would typically be considered actionable for reproductive decision-making. CONCLUSIONS: Individual specification of risk to offspring of adults in ASD-affected families is not straightforwardly improved by ascertainment of parental phenotype, and it is not yet clear whether genomic screening of prospective parents in families affected by idiopathic ASD is warranted as a clinical standard. Systematic screening of affected family members for heritable pathogenic variants, including rare sex-linked mutations, will identify a subset of families with substantially elevated transmission risk. Polygenic risk scores are only weakly predictive at this time but steadily improving and ultimately may enable more robust prediction either singly or when combined with the risk variables examined in this study

Shaping electron wave functions in a carbon nanotube with a parallel magnetic field

A magnetic field, through its vector potential, usually causes measurable changes in the electron wave function only in the direction transverse to the field. Here we demonstrate experimentally and theoretically that in carbon nanotube quantum dots, combining cylindrical topology and bipartite hexagonal lattice, a magnetic field along the nanotube axis impacts also the longitudinal profile of the electronic states. With the high (up to 17T) magnetic fields in our experiment the wave functions can be tuned all the way from "half-wave resonator" shape, with nodes at both ends, to "quarter-wave resonator" shape, with an antinode at one end. This in turn causes a distinct dependence of the conductance on the magnetic field. Our results demonstrate a new strategy for the control of wave functions using magnetic fields in quantum systems with nontrivial lattice and topology.Comment: 5 figure

Carbonaceous particulate matter on the lung surface from adults living in São Paulo, Brazil.

OBJECTIVES: We therefore sought to identify the exposures associated with lung surface in long-term residents of São Paulo, Brazil. METHODS: Lung surface carbon were analyzed in 72 autopsy specimens by image analysis. Smoking history, measured PM10 nearest to the home, distance to main road, and distance-weighted traffic density were used as exposure variables. Data are summarized as median (IQR), and compared by Mann Whitney Test, with correlations done by Spearman's correlation. RESULTS: There was no association between lung surface and age or gender. There was no statistically significant association in lung surface between smokers and non-smokers 6.74 cm2 (3.47 to 10.02) versus 5.20cm2 (2.29 to 7.54), and there was no significant association between lung surface carbon and exposure to environmental PM and markers of traffic exposure. CONCLUSION: We did not find a statistically significant association between lung surface and smokers and non-smokers, and no statistically significant association between lung surface carbon and environmental exposure variables. These results suggest that lung surface carbon in long-term residents of São Paulo may predominately be from environmental PM, but the most appropriate environmental exposure marker remains unclear.This study was supported by CAPES (Coordination for the Improvement of Higher Level -or Education- Personnel), Brazil, grant number: 99999.010610/2014-06, http://www.capes.gov.br/, to MP

The nature of the Lambda(1405)

We present here some results supporting the nature of the $\Lambda(1405)$ resonance as dynamically generated from the meson baryon interaction in coupled channels and resulting from the superposition of two close-by poles. We find support for this picture in the $K^- p \to \pi^0 \pi^0 \Sigma^0$ reaction, which shows a different shape than the one obtained from the $\pi ^- p \to K^0 \pi \Sigma$ reaction. We also call the attention to the $K^- p \to \gamma \pi \Sigma$ with $\pi \Sigma$ in the $\Lambda(1405)$ region, which shows a narrow peak in the calculations around 1420 MeV. We also report on recent calculations of the radiative decay of the two $\Lambda(1405)$ states and on reactions to obtain information on these decay modes. Finally, we present results for the $pp\to p K^+\Lambda(1405)$ reaction recently measured at ANKE/COSY and compare them with theoretical results.Comment: Talk given at the NSTAR2007 Workshop, Bonn September 200

Late Quaternary evolution of a lowland anastomosing river system: Geological-topographic inheritance, non-uniformity and implications for biodiversity and management

Lowland multiple-channel rivers are characterised by floodplain-corridor heterogeneity, high ecological and heritage value, and can be in quasi-stable states. This holistic study of a surviving temperate zone example (Culm, UK) uses geomorphological mapping, 14C, direct sediment dating (OSL, fallout radionuclides), and palaeoecology. This reveals the evolution of a channel-floodplain system from an initial braided state in the Late Pleistocene to its late Holocene anastomosing state. After the Pleistocene Holocene transition the reduced channel system incised into its braid-plain, only able to rework gravels locally due to reduced competence in relation to inherited bounding sediment calibre. This resulted in the creation of terrace islands, palaeochannels, and a stable anastomosing pattern dominated by channel junctions, bifurcations and palaeochannel intersections. Survey, coring and excavation reveal a persistence of mid-channel bars and riffles at channel junctions, and where channels crossed palaeochannel fills. In common with most other European lowland rivers this system evolves in the later Holocene due to both climate and catchment changes with a major hydrological critical transition in the mid-Holocene (c. 5300 BP). However, in the case of the Culm, the increase in fine sediment supply often seen in lowland catchments in the Middle-Late Holocene, occurred later, and was insufficient to convert the system to a single medium-low sinuosity channel-floodplain. This allowed the persistence of high heterogeneity and biodiversity (including the persistence of riffle beetles) as part of multiple-scales of non-uniformity. Indeed the pool-riffle persistence is an example of this system’s non-uniformity, being due, at least in part, to the effects of previous channel history. This paper reveals why this river survived in a multichannel state, and by implication, why others did not. These results are being used in the bespoke eco-heritage management of the Culm, but could also inform the restoration of other former multi-channel lowland temperate river systems worldwide