New biological models are incorporating the realistic processes underlying biological responses to climate change and other human-caused disturbances. However, these more realistic models require ...detailed information, which is lacking for most species on Earth. Current monitoring efforts mainly document changes in biodiversity, rather than collecting the mechanistic data needed to predict future changes. We describe and prioritize the biological information needed to inform more realistic projections of species' responses to climate change. We also highlight how trait-based approaches and adaptive modeling can leverage sparse data to make broader predictions. We outline a global effort to collect the data necessary to better understand, anticipate, and reduce the damaging effects of climate change on biodiversity.
Coherent X-ray microscopy by phase retrieval of Bragg diffraction intensities enables lattice distortions within a crystal to be imaged at nanometre-scale spatial resolutions in three dimensions. ...While this capability can be used to resolve structure-property relationships at the nanoscale under working conditions, strict data measurement requirements can limit the application of current approaches. Here, we introduce an efficient method of imaging three-dimensional (3D) nanoscale lattice behaviour and strain fields in crystalline materials with a methodology that we call 3D Bragg projection ptychography (3DBPP). This method enables 3D image reconstruction of a crystal volume from a series of two-dimensional X-ray Bragg coherent intensity diffraction patterns measured at a single incident beam angle. Structural information about the sample is encoded along two reciprocal-space directions normal to the Bragg diffracted exit beam, and along the third dimension in real space by the scanning beam. We present our approach with an analytical derivation, a numerical demonstration, and an experimental reconstruction of lattice distortions in a component of a nanoelectronic prototype device.
Aims/hypothesis
It is well established that diabetes mellitus increases the risk of cardiovascular disease (CVD) and all-cause mortality. Observational studies suggest that a history of diabetic foot ...ulceration (DFU) may increase this risk further still. We sought to determine to what extent DFU is associated with excess risk over and above diabetes.
Methods
We identified studies reporting on associations of DFU with CVD and all-cause mortality. We obtained data on incident events of all-cause mortality, fatal myocardial infarction and fatal stroke. Study-specific estimates were pooled using a random-effects meta-analysis and the statistical heterogeneity of included studies was assessed using the
I
2
statistic.
Results
The eight studies included reported on 3,619 events of all-cause mortality during 81,116 person-years of follow-up. DFU was associated with an increased risk of all-cause mortality (RR 1.89, 95% CI 1.60, 2.23), fatal myocardial infarction (2.22, 95% CI 1.09, 4.53) and fatal stroke (1.41, 95% CI 0.61, 3.24). CVD mortality accounted for a similar proportion of deaths in DFU and non-DFU patients.
Conclusions/interpretation
Patients with DFU have an excess risk of all-cause mortality, compared with patients with diabetes without a history of DFU. This risk is attributable, in part, to a greater burden of CVD. If this result is validated in other studies, strategies should evaluate the role of further aggressive CVD risk modification and ulcer prevention in those with DFU.
Diabet. Med. 28, 1144–1153 (2011)
Aim To quantify global variation in the incidence of lower extremity amputations in light of the rising prevalence of diabetes mellitus.
Methods An electronic ...search was performed using the EMBASE and MEDLINE databases from 1989 until 2010 for incidence of lower extremity amputation. The literature review conformed to Preferred Reporting Items for Systematic Reviews and Meta‐Analyses (PRISMA) statement standards.
Results Incidence of all forms of lower extremity amputation ranges from 46.1 to 9600 per 105 in the population with diabetes compared with 5.8–31 per 105 in the total population. Major amputation ranges from 5.6 to 600 per 105 in the population with diabetes and from 3.6 to 68.4 per 105 in the total population. Significant reductions in incidence of lower extremity amputation have been shown in specific at‐risk populations after the introduction of specialist diabetic foot clinics.
Conclusion Significant global variation exists in the incidence of lower extremity amputation. Ethnicity and social deprivation play a significant role but it is the role of diabetes and its complications that is most profound. Lower extremity amputation reporting methods demonstrate significant variation with no single standard upon which to benchmark care. Effective standardized reporting methods of major, minor and at‐risk populations are needed in order to quantify and monitor the growing multidisciplinary team effect on lower extremity amputation rates globally.
This study presents the application of a cost-effective, unmanned aerial vehicle (UAV) to investigate calving dynamics at a major marine-terminating outlet glacier draining the western sector of the ...Greenland ice sheet. The UAV was flown over Store Glacier on three sorties during summer 2013 and acquired over 2000 overlapping, geotagged images of the calving front at an similar to 40 cm ground sampling distance. Stereo-photogrammetry applied to these images enabled the extraction of high-resolution digital elevation models (DEMs) with vertical accuracies of plus or minus 1.9 m which were used to quantify glaciological processes from early July to late August 2013. The central zone of the calving front advanced by similar to 500 m, whilst the lateral margins remained stable. The orientation of crevasses and the surface velocity field derived from feature tracking indicates that lateral drag is the primary resistive force and that ice flow varies across the calving front from 2.5 m d super(-1) at the margins to in excess of 16 m d super(-1) at the centreline. Ice flux through the calving front is 3.8 107 m3 d super(-1), equivalent to 13.9 Gt a super(-1) and comparable to flux-gate estimates of Store Glacier's annual discharge. Water-filled crevasses were present throughout the observation period but covered a limited area of between 0.025 and 0.24% of the terminus and did not appear to exert any significant control over fracture or calving. We conclude that the use of repeat UAV surveys coupled with the processing techniques outlined in this paper have great potential for elucidating the complex frontal dynamics that characterise large calving outlet glaciers.
Ichthyoplankton surveys were conducted in surface waters of the northern Gulf of Mexico (NGoM) over a three-year period (2006-2008) to determine the relative value of this region as early life ...habitat of sailfish (Istiophorus platypterus), blue marlin (Makaira nigricans), white marlin (Kajikia albida), and swordfish (Xiphias gladius). Sailfish were the dominant billfish collected in summer surveys, and larvae were present at 37.5% of the stations sampled. Blue marlin and white marlin larvae were present at 25.0% and 4.6% of the stations sampled, respectively, while swordfish occurred at 17.2% of the stations. Areas of peak production were detected and maximum density estimates for sailfish (22.09 larvae 1000 m(-2)) were significantly higher than the three other species: blue marlin (9.62 larvae 1000 m(-2)), white marlin (5.44 larvae 1000 m(-2)), and swordfish (4.67 larvae 1000 m(-2)). The distribution and abundance of billfish and swordfish larvae varied spatially and temporally, and several environmental variables (sea surface temperature, salinity, sea surface height, distance to the Loop Current, current velocity, water depth, and Sargassum biomass) were deemed to be influential variables in generalized additive models (GAMs). Mesoscale features in the NGoM affected the distribution and abundance of billfish and swordfish larvae, with densities typically higher in frontal zones or areas proximal to the Loop Current. Habitat suitability of all four species was strongly linked to physicochemical attributes of the water masses they inhabited, and observed abundance was higher in slope waters with lower sea surface temperature and higher salinity. Our results highlight the value of the NGoM as early life habitat of billfishes and swordfish, and represent valuable baseline data for evaluating anthropogenic effects (i.e., Deepwater Horizon oil spill) on the Atlantic billfish and swordfish populations.
Abstract
The Bloch point is a point singularity in the magnetisation configuration, where the magnetisation vanishes. It can exist as an equilibrium configuration and plays an important role in many ...magnetisation reversal processes. In the present work, we focus on manipulating Bloch points in a system that can host stable Bloch points—a two-layer FeGe nanostrip with opposite chirality of the two layers. We drive Bloch points using spin-transfer torques and find that Bloch points can move collectively without any Hall effect and report that Bloch points are repelled from the sample boundaries and each other. We study pinning of Bloch points at wedge-shaped constrictions (notches) in the nanostrip and demonstrate that arrays of Bloch points can be moved past a series of notches in a controlled manner by applying consecutive current pulses of different strength. Finally, we simulate a T-shaped geometry and demonstrate that a Bloch point can be moved along different paths by applying current between suitable strip ends.
The fundamental building blocks of the proton-quarks and gluons-have been known for decades. However, we still have an incomplete theoretical and experimental understanding of how these particles and ...their dynamics give rise to the quantum bound state of the proton and its physical properties, such as its spin
. The two up quarks and the single down quark that comprise the proton in the simplest picture account only for a few per cent of the proton mass, the bulk of which is in the form of quark kinetic and potential energy and gluon energy from the strong force
. An essential feature of this force, as described by quantum chromodynamics, is its ability to create matter-antimatter quark pairs inside the proton that exist only for a very short time. Their fleeting existence makes the antimatter quarks within protons difficult to study, but their existence is discernible in reactions in which a matter-antimatter quark pair annihilates. In this picture of quark-antiquark creation by the strong force, the probability distributions as a function of momentum for the presence of up and down antimatter quarks should be nearly identical, given that their masses are very similar and small compared to the mass of the proton
. Here we provide evidence from muon pair production measurements that these distributions are considerably different, with more abundant down antimatter quarks than up antimatter quarks over a wide range of momenta. These results are expected to revive interest in several proposed mechanisms for the origin of this antimatter asymmetry in the proton that had been disfavoured by previous results
, and point to future measurements that can distinguish between these mechanisms.
Abstract
Unusual features in the Hall Resistivity of thin film systems are frequently associated with whirling spin textures such as Skyrmions. A host of recent investigations of Hall Hysteresis ...loops in SrRuO
3
heterostructures have provided conflicting evidence for different causes for such features. We have constructed an SrRuO
3
-PbTiO
3
(Ferromagnetic – Ferroelectric) bilayer that exhibits features in the Hall Hysteresis previously attributed to a Topological Hall Effect, and Skyrmions. Here we show field dependent Magnetic Force Microscopy measurements throughout the key fields where the ‘THE’ presents, revealing the emergence to two periodic, chiral spin textures. The zero-field cycloidal phase, which then transforms into a
‘double-q’
incommensurate spin crystal appears over the appearance of the ‘Topological-like’ Hall effect region, and develop into a ferromagnetic switching regime as the sample reaches saturation, and the ‘Topological-like’ response diminishes. Scanning Tunnelling Electron Microscopy and Density Functional Theory is used to observe and analyse surface inversion symmetry breaking and confirm the role of an interfacial Dzyaloshinskii–Moriya interaction at the heart of the system.
An intense 120 GeV proton beam incident on an extremely long iron target generates enormous numbers of light-mass particles that also decay within that target. If one of these particles decays to a ...final state with a hidden gauge boson, or if such a particle is produced as a result of the initial collision, then that weakly interacting hidden-sector particle may traverse the remainder of the target and be detected downstream through its possible decay to an e super(+)e super(-), mu super(+)mu super(-), or pi super(+)pi super(-) final state. These conditions can be realized through an extension of the SeaQuest experiment at Fermilab, and in this initial investigation we consider how it can serve as an ultrasensitive probe of hidden vector gauge forces, both Abelian and non-Abelian. A light, weakly coupled hidden sector may well explain the dark matter established through astrophysical observations, and the proposed search can provide tangible evidence for its existence-or, alternatively, constrain a "sea" of possibilities.
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