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Controls on development and diversity of Early Archean stromatolites
The ≈3,450-million-year-old Strelley Pool Formation in Western Australia contains a reef-like assembly of laminated sedimentary accretion structures (stromatolites) that have macroscale characteristics suggestive of biological influence. However, direct microscale evidence of biology—namely, organic microbial remains or biosedimentary fabrics—has to date eluded discovery in the extensively-recrystallized rocks. Recently-identified outcrops with relatively good textural preservation record microscale evidence of primary sedimentary processes, including some that indicate probable microbial mat formation. Furthermore, we find relict fabrics and organic layers that covary with stromatolite morphology, linking morphologic diversity to changes in sedimentation, seafloor mineral precipitation, and inferred microbial mat development. Thus, the most direct and compelling signatures of life in the Strelley Pool Formation are those observed at the microscopic scale. By examining spatiotemporal changes in microscale characteristics it is possible not only to recognize the presence of probable microbial mats during stromatolite development, but also to infer aspects of the biological inputs to stromatolite morphogenesis. The persistence of an inferred biological signal through changing environmental circumstances and stromatolite types indicates that benthic microbial populations adapted to shifting environmental conditions in early oceans
Incremental Material Flow Analysis with Bayesian Inference
Material Flow Analysis (MFA) is widely used to study the life-cycles of materials from production, through use, to reuse, recycling or disposal, in order to identify environmental impacts and opportunities to address them. However, development of this type of analysis is often constrained by limited data, which may be uncertain, contradictory, missing or over-aggregated.
This article proposes a Bayesian approach, in which uncertain knowledge about material flows is described by probability distributions. If little data is initially available, the model predictions will be rather vague. As new data is acquired, it is systematically incorporated to reduce the level of uncertainty.
After reviewing previous approaches to uncertainty in MFA, the Bayesian approach is introduced, and a general recipe for its application to Material Flow Analysis is developed. This is applied to map global production of steel, using Markov Chain Monte Carlo simulations. As well as aiding the analyst, who can get started in the face of incomplete data, this incremental approach to MFA also supports efforts to improve communication of results by transparently accounting for uncertainty throughout.ngineering and Physical Sciences Research Council. Grant Numbers: EP/K039326/1, EP/N02351x/
Study of diffusion weighted MRI as a predictive biomarker of response during radiotherapy for high and intermediate risk squamous cell cancer of the oropharynx: The MeRInO study
Introduction and background:
A significant proportion of patients with intermediate and high risk squamous cell cancer of the oropharynx (OPSCC) continue to relapse locally despite radical chemoradiotherapy (CRT). The toxicity of the current combination of intensified dose per fraction radiotherapy and platinum based chemotherapy limits further uniform intensification. If a predictive biomarker for outcomes from CRT can be identified during treatment then individualised and adaptive treatment strategies may be employed.
Methods/design:
The MeRInO study is a prospective observational imaging study of patients with intermediate and high risk, locally advanced OPSCC receiving radical RT or concurrent CRT Patients undergo diffusion weighted MRI prior to treatment (MRI_1) and during the third week of RT (MRI_2). Apparent diffusion coefficient (ADC) measurements will be made on each scan for previously specified target lesions (primary and lymph nodes) and change in ADC calculated. Patients will be followed up and disease status for each target lesion noted. The primary aim of the MeRInO study is to determine the threshold change in ADC from baseline to week 3 of RT that may identify the sub-group of non-responders during treatment.
Discussion:
The use of DW-MRI as a predictive biomarker during RT for SCC H&N is in its infancy but studies to date have found that response to treatment may indeed be predicted by comparison of DW-MRI carried out before and during treatment. However, previous studies have included all sub-sites and biological sub-types. Establishing ADC thresholds that predict for local failure is an essential step towards using DW-MRI to improve the therapeutic ratio in treating SCC H&N. This would be done most robustly in a specific H&N sub-site and in sub-types with similar biological behaviour. The MeRInO study will help establish these thresholds in OPSCC
Multimode switching induced by a transverse field planar magnetic nanowires
We report how transverse fields affect the axial field needed to "inject" domain walls from a large Permalloy (Ni80Fe20) pad into planar nanowires of width 184 nm, 303 nm, 321 nm, and 537 nm fabricated by electron beam lithography. For the narrowest wire, different switching fields are observed under the same transverse field conditions, indicating that more than one mode or state for the domain walls may exist. In contrast, in the widest wires a transverse field causes each reversal event to occur in two stages. The different response may be attributed to the magnetostatic energy differences of domain walls in wires of different widths
Higgsless electroweak symmetry breaking at the LHC
While the Higgs model is the best studied scenario of electroweak symmetry
breaking, a number strongly-coupled models exist, predicting new signatures.
Recent studies of WW and WZ final states at the ATLAS and CMS experiments are
summarized and expected sensitivities are presented within the frameworks of
the technicolor straw-man model and the electroweak chiral Lagrangian.Comment: Proceedings for the EPS HEP 2007 conference, Manchester, U.K., on
behalf of the ATLAS and CMS Collaboration
Manipulating ultracold atoms with a reconfigurable nanomagnetic system of domain walls
The divide between the realms of atomic-scale quantum particles and
lithographically-defined nanostructures is rapidly being bridged. Hybrid
quantum systems comprising ultracold gas-phase atoms and substrate-bound
devices already offer exciting prospects for quantum sensors, quantum
information and quantum control. Ideally, such devices should be scalable,
versatile and support quantum interactions with long coherence times.
Fulfilling these criteria is extremely challenging as it demands a stable and
tractable interface between two disparate regimes. Here we demonstrate an
architecture for atomic control based on domain walls (DWs) in planar magnetic
nanowires that provides a tunable atomic interaction, manifested experimentally
as the reflection of ultracold atoms from a nanowire array. We exploit the
magnetic reconfigurability of the nanowires to quickly and remotely tune the
interaction with high reliability. This proof-of-principle study shows the
practicability of more elaborate atom chips based on magnetic nanowires being
used to perform atom optics on the nanometre scale.Comment: 4 pages, 4 figure
Material Stock Demographics: Cars in Great Britain.
Recent literature on material flow analysis has been focused on quantitative characterization of past material flows. Fewer analyses exist on past and prospective quantification of stocks of materials in-use. Some of these analyses explore the composition of products' stocks, but a focus on the characterization of material stocks and its relation with service delivery is often neglected. We propose the use of the methods of human demography to characterize material stocks, defined herein as stock demographics, exploring the insights that this approach could provide for the sustainable management of materials. We exemplify an application of stock demographics by characterizing the composition and service delivery of iron, steel, and aluminum stocks of cars in Great Britain, 2002-2012. The results show that in this period the stock has become heavier, it is traveling less, and it is idle for more time. The visualization of material stocks' dynamics demonstrates the pace of product replacement as a function of its usefulness and enables the formulation of policy interventions and the exploration of future trends.This work was supported by EPSRC, grant reference EP/N02351X/1.This is the final version of the article. It first appeared from the American Chemical Society via https://doi.org/10.1021/acs.est.5b0501
Controlled motion of domain walls in submicron amorphous wires
© 2016 Author(s). Results on the control of the domain wall displacement in cylindrical Fe77.5Si7.5B15 amorphous glass-coated submicron wires prepared by rapid quenching from the melt are reported. The control methods have relied on conical notches with various depths, up to a few tens of nm, made in the glass coating and in the metallic nucleus using a focused ion beam (FIB) system, and on the use of small nucleation coils at one of the sample ends in order to apply magnetic field pulses aimed to enhance the nucleation of reverse domains. The notch-based method is used for the first time in the case of cylindrical ultrathin wires. The results show that the most efficient technique of controlling the domain wall motion in this type of samples is the simultaneous use of notches and nucleation coils. Their effect depends on wire diameter, notch depth, its position on the wire length, and characteristics of the applied pulse
Observation of Magnetic Supercooling of the Transition to the Vortex State
We demonstrate that the transition from the high-field state to the vortex
state in a nanomagnetic disk shows the magnetic equivalent of supercooling.
This is evidence that this magnetic transition can be described in terms of a
modified Landau first-order phase transition. To accomplish this we have
measured the bulk magnetization of single magnetic disks using nanomechanical
torsional resonator torque magnetometry. This allows observation of single
vortex creation events without averaging over an array of disks or over
multiple runs.Comment: 11 pages preprint, 4 figures, accepted to New Journal of Physic
Temperature dependence of electrical properties of electrodeposited Ni-based nanowires
The influence of annealing on the microstructure and the electrical properties of cylindrical nickel-based nanowires has been investigated. Nanowires of nickel of nominally 200 nm diameter and of permalloy (Py) of nominally 70 nm were fabricated by electrochemical deposition into nanoporous templates of polycarbonate and anodic alumina, respectively. Characterization was carried out on as-grown nanowires and nanowires heat treated at 650°C. Transmission electron microscopy and diffraction imaging of as-grown and annealed nanowires showed temperature-correlated grain growth of an initially nano-crystalline structure with ≤8 nm (Ni) and ≤20 nm (Py) grains towards coarser poly-crystallinity with grain sizes up to about 160 nm (Ni) and 70 nm (Py), latter being limited by the nanowire width. The electrical conductivity of individual as-grown and annealed Ni nanowires was measured in situ within a scanning electron microscope environment. At low current densities, the conductivity of annealed nanowires was estimated to have risen by a factor of about two over as-grown nanowires. We attribute this increase, at least in part, to the observed grain growth. The annealed nanowire was subsequently subjected to increasing current densities. Above 120 kA mm -2 the nanowire resistance started to rise. At 450 kA mm -2 the nanowire melted and current flow ceased
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