The contribution of grass and clover root turnover to N leaching

Sources of inorganic and organic N leaching from grass-clover mixtures at field sites in Denmark, Germany and Iceland were investigated. Grass or clover was labelled with 15N-urea four times (autumn 2007, spring, summer and autumn 2008) prior to the leaching season in autumn and winter 2008. Soil water was sampled at 30 cm depth and analyzed for 15N-enrichment of dissolved inorganic N (DIN) and dissolved organic N (DON). Most 15N was recovered in DON for both labelled grass and clover at all sites. At the Danish site, grass and clover contributed more to the DON pool than the DIN whereas the opposite was observed at the German and Icelandic sites. The results show that both clover and grass contribute directly to N leaching from the root zone in mixtures, and that clover contribution is higher than grass. Furthermore, the present study indicates that roots active in the growth season prior to the drainage period contribute more to N leaching than roots active in the growth season the previous year, which is consistent with estimates of root longevity at the three sites

Protein folding rates correlate with heterogeneity of folding mechanism

By observing trends in the folding kinetics of experimental 2-state proteins at their transition midpoints, and by observing trends in the barrier heights of numerous simulations of coarse grained, C-alpha model, Go proteins, we show that folding rates correlate with the degree of heterogeneity in the formation of native contacts. Statistically significant correlations are observed between folding rates and measures of heterogeneity inherent in the native topology, as well as between rates and the variance in the distribution of either experimentally measured or simulated phi-values.Comment: 11 pages, 3 figures, 1 tabl

Organisational interventions designed to reduce caesarean section rates: a systematic review protocol.

INTRODUCTION: There is a growing body of evidence to indicate that both primary and subsequent caesarean sections are associated with increased maternal and perinatal morbidity. Efforts to reduce the number of clinically unnecessary caesarean sections are urgently required. Our objective is to systematically review published evidence on the effectiveness of maternity service organisational interventions, such as models of maternity care, that aim to reduce caesarean section rates. METHODS AND ANALYSIS: Databases will be searched, including the Cochrane Central Register of Controlled Trials, Cumulative Index to Nursing and Allied Health Literature, MEDLINE, Maternity and Infant Care, EMBASE and SCOPUS. Search terms related to caesarean section and organisational intervention will be used. Research published before 1980 will be excluded and only randomised controlled trials, cluster-randomised controlled trials, quasi-randomised controlled trials, controlled before and after studies and interrupted time series studies will be included. Data extraction and quality assessments will be undertaken by two authors. ETHICS AND DISSEMINATION: Ethics approval is not required for this systematic review. The results of this study will be disseminated via peer-reviewed publication and presentation at professional conferences. PROSPERO REGISTRATION NUMBER: CRD42016039458

One step multiderivative methods for first order ordinary differential equations

A family of one-step multiderivative methods based on Padé approximants to the exponential function is developed. The methods are extrapolated and analysed for use in PECE mode. Error constants and stability intervals are calculated and the combinations compared with well known linear multi-step combinations and combinations using high accuracy Newton-Cotes quadrature formulas as correctors. w926020

Urban energy exchanges monitoring from space

One important challenge facing the urbanization and global environmental change community is to understand the relation between urban form, energy use and carbon emissions. Missing from the current literature are scientific assessments that evaluate the impacts of different urban spatial units on energy fluxes; yet, this type of analysis is needed by urban planners, who recognize that local scale zoning affects energy consumption and local climate. However, satellite-based estimation of urban energy fluxes at neighbourhood scale is still a challenge. Here we show the potential of the current satellite missions to retrieve urban energy budget, supported by meteorological observations and evaluated by direct flux measurements. We found an agreement within 5% between satellite and in-situ derived net all-wave radiation; and identified that wall facet fraction and urban materials type are the most important parameters for estimating heat storage of the urban canopy. The satellite approaches were found to underestimate measured turbulent heat fluxes, with sensible heat flux being most sensitive to surface temperature variation (-64.1, +69.3 W m-2 for ±2 K perturbation); and also underestimate anthropogenic heat flux. However, reasonable spatial patterns are obtained for the latter allowing hot-spots to be identified, therefore supporting both urban planning and urban climate modelling

Challenges in the delivery of e-government through kiosks

Kiosks are increasingly being heralded as a technology through which governments, government departments and local authorities or municipalities can engage with citizens. In particular, they have attractions in their potential to bridge the digital divide. There is some evidence to suggest that the citizen uptake of kiosks and indeed other channels for e-government, such as web sites, is slow, although studies on the use of kiosks for health information provision offer some interesting perspectives on user behaviour with kiosk technology. This article argues that the delivery of e-government through kiosks presents a number of strategic challenges, which will need to be negotiated over the next few years in order that kiosk applications are successful in enhancing accessibility to and engagement with e-government. The article suggests that this involves consideration of: the applications to be delivered through a kiosk; one stop shop service and knowledge architectures; mechanisms for citizen identification; and, the integration of kiosks within the total interface between public bodies and their communities. The article concludes by outlining development and research agendas in each of these areas.</p

Two-Level Atom in an Optical Parametric Oscillator: Spectra of Transmitted and Fluorescent Fields in the Weak Driving Field Limit

We consider the interaction of a two-level atom inside an optical parametric oscillator. In the weak driving field limit, we essentially have an atom-cavity system driven by the occasional pair of correlated photons, or weakly squeezed light. We find that we may have holes, or dips, in the spectrum of the fluorescent and transmitted light. This occurs even in the strong-coupling limit when we find holes in the vacuum-Rabi doublet. Also, spectra with a sub-natural linewidth may occur. These effects disappear for larger driving fields, unlike the spectral narrowing obtained in resonance fluorescence in a squeezed vacuum; here it is important that the squeezing parameter $N$ tends to zero so that the system interacts with only one correlated pair of photons at a time. We show that a previous explanation for spectral narrowing and spectral holes for incoherent scattering is not applicable in the present case, and propose a new explanation. We attribute these anomalous effects to quantum interference in the two-photon scattering of the system.Comment: 10 pages, 17 figures, submitted to Phys Rev

Dynamic buckling and fragmentation in brittle rods

We present experiments on the dynamic buckling and fragmentation of slender rods axially impacted by a projectile. By combining the results of Saint-Venant and elastic beam theory, we derive a preferred wavelength lambda for the buckling instability, and experimentally verify the resulting scaling law for a range of materials including teflon, dry pasta, glass, and steel. For brittle materials, buckling leads to the fragmentation of the rod. Measured fragment length distributions show two clear peaks near lambda/2 and lambda/4. The non-monotonic nature of the distributions reflect the influence of the deterministic buckling process on the more random fragmentation processes.Comment: 4 pages, 5 figures, submitted to Physical Review Letter

Cooling atomic motion with quantum interference

We theoretically investigate the quantum dynamics of the center of mass of trapped atoms, whose internal degrees of freedom are driven in a $\Lambda$-shaped configuration with the lasers tuned at two-photon resonance. In the Lamb-Dicke regime, when the motional wave packet is well localized over the laser wavelenght, transient coherent population trapping occurs, cancelling transitions at the laser frequency. In this limit the motion can be efficiently cooled to the ground state of the trapping potential. We derive an equation for the center-of-mass motion by adiabatically eliminating the internal degrees of freedom. This treatment provides the theoretical background of the scheme presented in [G. Morigi {\it et al}, Phys. Rev. Lett. {\bf 85}, 4458 (2000)] and implemented in [C.F. Roos {\it et al}, Phys. Rev. Lett. {\bf 85}, 5547 (2000)]. We discuss the physical mechanisms determining the dynamics and identify new parameters regimes, where cooling is efficient. We discuss implementations of the scheme to cases where the trapping potential is not harmonic.Comment: 11 pages, 3 figure