Globalization, international law, and emerging infectious diseases.

The global nature of the threat posed by new and reemerging infectious diseases will require international cooperation in identifying, controlling, and preventing these diseases. Because of this need for international cooperation, international law will certainly play a role in the global strategy for the control of emerging diseases. Recognizing this fact, the World Health Organization has already proposed revising the International Health Regulations. This article examines some basic problems that the global campaign against emerging infectious diseases might face in applying international law to facilitate international cooperation. The international legal component of the global control strategy for these diseases needs careful attention because of problems inherent in international law, especially as it applies to emerging infections issues

Spin-torque switching: Fokker-Planck rate calculation

We describe a new approach to understanding and calculating magnetization switching rates and noise in the recently observed phenomenon of "spin-torque switching". In this phenomenon, which has possible applications to information storage, a large current passing from a pinned ferromagnetic (FM) layer to a free FM layer switches the free layer. Our main result is that the spin-torque effect increases the Arrhenius factor $\exp(-E/kT)$ in the switching rate, not by lowering the barrier $E$, but by raising the effective spin temperature $T$. To calculate this effect quantitatively, we extend Kramers' 1940 treatment of reaction rates, deriving and solving a Fokker-Planck equation for the energy distribution including a current-induced spin torque of the Slonczewski type. This method can be used to calculate slow switching rates without long-time simulations; in this Letter we calculate rates for telegraph noise that are in good qualitative agreement with recent experiments. The method also allows the calculation of current-induced magnetic noise in CPP (current perpendicular to plane) spin valve read heads.Comment: 11 pages, 8 figures, 1 appendix Original version in Nature format, replaced by Phys. Rev. Letters format. No substantive change

Effect of fluoridated toothpicks and dental flosses on enamel and dentine and on plaque composition in situ

The aim was to evaluate the effect of two toothpicks and two dental flosses on demineralized enamel and dentine and on plaque composition, using an in situ model with simulated approximal spaces within dentures. Fifteen subjects with full dentures were recruited and 14 completed the study. It consisted of two crossover periods, the first comparing a birch toothpick with AmF and a birch toothpick with NaF, and the second comparing a dental floss with AmF + NaF and a dental floss without F. Between these four periods, there was a control period without any approximal cleaning. In small, rectangular sample holders, one enamel and one dentine specimen were embedded, forming a triangular, approximal-like space. Two sample holders were mounted in the premolar-molar region of the upper or lower dentures. The subjects used the toothpicks or dental flosses 3 times/day for 4 weeks. The results showed that all toothpicks and dental flosses inhibited further demineralization compared to the control period ( p <0.001). The dental flosses were somewhat more effective in this respect than the toothpicks, especially in dentine. There were relatively small numerical differences between AmF and NaF toothpicks, but in favour of NaF regarding mineral gain ( p <0.05). The fluoridated floss gave somewhat less lesion depth in dentine than the non-fluoridated floss ( p <0.01). Toothpicks and flosses resulted in lower counts of microorganisms in plaque compared to the control period ( p <0.001); the AmF toothpick gave a more pronounced reduction than the NaF toothpick ( p <0.001). Copyright (C) 2005 S. Karger AG, Basel

Monitoring a large construction site using wireless sensor networks

Despite the significant advances made by wireless sensor network research, deployments of such networks in real application environments are fraught with significant difficulties and challenges that include robust topology design, network diagnostics and maintenance. Based on our experience of a six-month-long wireless sensor network deployment in a large construction site, we highlight these challenges and argue the need for new tools and enhancements to current protocols to address these challenges.This research has been funded by the EPSRC Innovation and Knowledge Centre for Smart Infrastructure and Construction project (EP/K000314/1). We would like to thank Costain-Skanska Joint Venture (CSJV) and our industrial partner Crossrail for allowing access and instrumentation of the Paddington site. We would also like to thank Dr Munenori Shibata from Japan Railway Technical Research Institute for his assistance with network deployment.This is the author accepted manuscript. The final version is available from ACM via http://dx.doi.org/10.1145/2820990.2820997 Data supporting this paper is available from https://www.repository.cam.ac.uk/handle/1810/250538

Magnetic properties of (Fe1−x_{1-x}Cox_x)2_2B alloys and the effect of doping by 5dd elements

We have explored, computationally and experimentally, the magnetic properties of \fecob{} alloys. Calculations provide a good agreement with experiment in terms of the saturation magnetization and the magnetocrystalline anisotropy energy with some difficulty in describing Co$_2$B, for which it is found that both full potential effects and electron correlations treated within dynamical mean field theory are of importance for a correct description. The material exhibits a uniaxial magnetic anisotropy for a range of cobalt concentrations between $x=0.1$ and $x=0.5$. A simple model for the temperature dependence of magnetic anisotropy suggests that the complicated non-monotonous temperature behaviour is mainly due to variations in the band structure as the exchange splitting is reduced by temperature. Using density functional theory based calculations we have explored the effect of substitutional doping the transition metal sublattice by the whole range of 5$d$ transition metals and found that doping by Re or W elements should significantly enhance the magnetocrystalline anisotropy energy. Experimentally, W doping did not succeed in enhancing the magnetic anisotropy due to formation of other phases. On the other hand, doping by Ir and Re was successful and resulted in magnetic anisotropies that are in agreement with theoretical predictions. In particular, doping by 2.5~at.\% of Re on the Fe/Co site shows a magnetocrystalline anisotropy energy which is increased by 50\% compared to its parent (Fe$_{0.7}$Co$_{0.3}$)$_2$B compound, making this system interesting, for example, in the context of permanent magnet replacement materials or in other areas where a large magnetic anisotropy is of importance.Comment: 15 pages 17 figure

Wireless sensor monitoring of Paddington Station Box Corner

This paper presents the real performance of three diaphragm wall panels on the southeast corner of Paddington Station Box during excavation, monitored using a wireless sensor network. In total, 15 LPDT displacement sensors, 12 tilt sensors, 13 relay nodes and a gateway were deployed at three different stages. Each wireless sensor node is programmed with Contiki OS using the in-built IPv6-based network layer (6LoWPAN/RPL) for link-local addressing and routing, and ContikiMAC at the medium access control (MAC) layer for radio duty cycling. Extensive testing and calibration was carried out in the laboratory to ensure that the system functioned as expected. Wireless tilt and displacement sensors were installed to measure the inclination, angular distortion and relative displacement of these corner panels at three different depths. The monitoring data reveal that the corner produced a stiffening effect on the station box, which might result in a breakdown of plane strain conditions. The network performance characteristics (e.g. message reception ratio and network topology status) and challenges are also highlighted and discussed

Multiscale nature of hysteretic phenomena: Application to CoPt-type magnets

We suggest a workable approach for the description of multiscale magnetization reversal phenomena in nanoscale magnets and apply it to CoPt-type alloys. We show that their hysteretic properties are governed by two effects originating at different length scales: a peculiar splitting of domain walls and their strong pinning at antiphase boundaries. We emphasize that such multiscale nature of hysteretic phenomena is a generic feature of nanoscale magnetic materials.Comment: 4 pages (revtex 4), 2 color EPS figure

A modified version of the Bayley Scales of Infant Development-II for cognitive matching of infants with and without Down syndrome

Background Many measures of infants' early cognitive development, including the BSID-II (The Bayley Scales of Infant Development), mix together test items that assess a number of different developmental domains including language, attention, motor functioning and social abilities, and some items contribute to the assessment of more than one domain. Consequently, the scales may lead to under- or over-estimates of cognitive abilities in some clinical samples and may not be the best measure to use for matching purposes. Method To address this issue we created a modified form of the BSID-II (the BSID-M) to provide a ‘purer’ assessment of the general cognitive capacities in infants with Down syndrome (DS) from 6 to 18 months of age. We excluded a number of items that implicated language, motor, attentional and social functioning from the original measure. This modified form was administered to 17 infants with Down syndrome when 6, 12 and 18 months old and to 41 typically developing infants at 4, 7 and 10 months old. Results The results suggested that the modified form continued to provide a meaningful and stable measure of cognitive functioning and revealed that DS infants may score marginally higher in terms of general cognitive abilities when using this modified form than they might when using the standard BSID-II scales. Conclusions This modified form may be useful for researchers who need a ‘purer’ measure with which to match infants with DS and other infants with intellectual disabilities on cognitive functioning

Non-resonant Coherent Amplitude Transfer in Attosecond Four-Wave Mixing Spectroscopy

Attosecond four-wave mixing spectroscopy using an XUV pulse and two noncollinear near-infrared pulses is employed to measure Rydberg wavepacket dynamics resulting from extreme ultraviolet excitation of a 3s electron in atomic argon into a series of autoionizing 3s-1np Rydberg states around 29 eV. The emitted signals from individual Rydberg states exhibit oscillatory structure and persist well beyond the expected lifetimes of the emitting Rydberg states. These results reflect substantial contributions of longer-lived Rydberg states to the four wave mixing emission signals of each individually detected state. A wavepacket decomposition analysis reveals that coherent amplitude transfer occurs predominantly from photoexcited 3s-1(n+1)p states to the observed 3s-1np Rydberg states. The experimental observations are reproduced by time-dependent Schr\"odinger equation simulations using electronic structure and transition moment calculations. The theory highlights that coherent amplitude transfer is driven non-resonantly to the 3s-1np states by the near-infrared light through 3s-1(n+1)s and 3s-1(n-1)d dark states during the four-wave mixing process