The Economy of Communist China: Its Present Status and its Future Prospects

It is my purpose to give you some idea of the economy of Communist China—where the economy stands today, and where it is going and how fast

Development of a cobalt-tungsten ferromagnetic, high-temperature, structural alloy

Cobalt-tungsten ferromagnetic, high temperature structural alloy for rotor applications in space power generator

Extreme morning chronotypes are often familial and not exceedingly rare: the estimated prevalence of advanced sleep phase, familial advanced sleep phase, and advanced sleep-wake phase disorder in a sleep clinic population.

Study objectivesReport the first prevalence estimates of advanced sleep phase (ASP), familial advanced sleep phase (FASP), and advanced sleep-wake phase disorder (ASWPD). This can guide clinicians on the utility of screening for extreme chronotypes both for clinical decision-making and to flag prospective participants in the study of the genetics and biology of FASP.MethodsData on morning or evening sleep schedule preference (chronotype) were collected from 2422 new patients presenting to a North American sleep center over 9.8 years. FASP was determined using a severity criterion that has previously identified dominant circadian mutations in humans. All patients were personally seen and evaluated by one of the authors (C.R.J.).ResultsOur results demonstrate an ASP prevalence of 0.33%, an FASP prevalence of 0.21%, and an ASWPD prevalence of at least 0.04%. Most cases of young-onset ASP were familial.ConclusionsAmong patients presenting to a sleep clinic, conservatively 1 out of every 300 patients will have ASP, 1 out of every 475 will have FASP, and 1 out of every 2500 will have ASWPD. This supports obtaining a routine circadian history and, for those with extreme chronotypes, obtaining a family history of circadian preference. This can optimize treatment for evening sleepiness and early morning awakening and lead to additional circadian gene discovery. We hope these findings will lead to improved treatment options for a wide range of sleep and medical disorders in the future

Superflares on Ordinary Solar-Type Stars

Short duration flares are well known to occur on cool main-sequence stars as well as on many types of `exotic' stars. Ordinary main-sequence stars are usually pictured as being static on time scales of millions or billions of years. Our sun has occasional flares involving up to $\sim 10^{31}$ ergs which produce optical brightenings too small in amplitude to be detected in disk-integrated brightness. However, we identify nine cases of superflares involving $10^{33}$ to $10^{38}$ ergs on normal solar-type stars. That is, these stars are on or near the main-sequence, are of spectral class from F8 to G8, are single (or in very wide binaries), are not rapid rotators, and are not exceedingly young in age. This class of stars includes many those recently discovered to have planets as well as our own Sun, and the consequences for any life on surrounding planets could be profound. For the case of the Sun, historical records suggest that no superflares have occurred in the last two millennia.Comment: 16 pages, accepted for publication in Ap

Computational NMR investigation of mixed-metal (Al,Sc)-MIL-53 and its phase transitions

Funding: The authors would like to thank the ERC (Advanced Grant 787073 ADOR) and the Allan Handsel Postgraduate Research Scholarship for Chemistry for studentship funding for ZHD and EALB, respectively. We also acknowledge support from the Collaborative Computational Project on NMR Crystallography (CCP-NC) funded by EPSRC (EP/T026642/1) and from the UK Materials and Molecular Modelling Hub (Young), which is partially funded by EPSRC (EP/T022213/1, EP/W032260/1 and EP/P020194/1) for which access was obtained via the UKCP consortium and funded by EPSRC (EP/P022561/1).Compositionally complex metal-organic frameworks (MOFs) have properties that depend on local structure that is often difficult to characterise. In this paper a density functional theory (DFT) computational study of mixed-metal (Al,Sc)-MIL-53, a flexible MOF with several different forms, was used to calculate the relative energetics of these forms and to predict NMR parameters that can be used to evaluate whether solid-state NMR spectroscopy can be used to differentiate, identify and characterise the forms adopted by mixed-metal MOFs of different composition. The NMR parameters can also be correlated with structural features in the different forms, giving fundamental insight into the nature and origin of the interactions that affect nuclear spins. Given the complexity of advanced NMR experiments required, and the potential need for expensive and difficult isotopic enrichment, the computational work is invaluable in predicting which experiments and approaches are likely to give the most information on the disorder, local structure and pore forms of these mixed-metal MOFs.Publisher PDFPeer reviewe

Sterically restricted tin phosphines, stabilized by weak intramolecular donor-acceptor interactions

Funding: Engineering and Physical Sciences Research Council (EPSRC)Four related sterically restricted pen-substituted acenaphthenes have been prepared containing mixed tin phosphorus moieties in the proximal 5,6-positions (Acenap[SnR3][(PPr2)-Pr-i]; Acenap = acenaphthene-5,6-diyl; R-3 = Ph-3 (1), Ph2Cl (2), Me2Cl (3), Bu2Cl (4)). The degree of intramolecular P-Sn bonding within the series was investigated by X-ray crystallography, solution and solid-state NMR spectroscopy, and density functional theory (DFT/B3LYP/SBKJC/PCM) calculations. All members of the series adopt a conformation such that the phosphorus lone pair is located directly opposite the tin center, promoting an intramolecular donor acceptor P -> Sn type interaction. The extent of covalent bonding between Sn and P is found to be much greater in triorganotin chlorides 2-4 in comparison with the triphenyl derivative 1. Coordination of a highly electronegative chlorine atom naturally increases the Lewis acidity of the tin center, enhancing the Ip(P)-sigma*(Sn-Y) donor acceptor 3c-4e type interaction, as indicated by conspicuously short Sn-P peri distances and significant (1)J(P-31,Sn-119) spin spin coupling constants (SSCCs) in the range 740-754 Hz. Evidence supporting the presence of this interaction was also found in solid-state NMR spectra of some of the compounds which exhibit an indirect spin spin coupling on the same order of magnitude as observed in solution. DFT calculations confirm the increased covalent bonding between P and Sn in 2-4, with notable WBIs of ca. 0.35 obtained, in comparison to 0.1 in 1.PostprintPeer reviewe

Semantically enhancing multimedia lifelog events

Lifelogging is the digital recording of our everyday behaviour in order to identify human activities and build applications that support daily life. Lifelogs represent a unique form of personal multimedia content in that they are temporal, synchronised, multi-modal and composed of multiple media. Analysing lifelogs with a view to supporting content-based access, presents many challenges. These include the integration of heterogeneous input streams from different sensors, structuring a lifelog into events, representing events, and interpreting and understanding lifelogs. In this paper we demonstrate the potential of semantic web technologies for analysing lifelogs by automatically augmenting descriptions of lifelog events. We report on experiments and demonstrate how our re- sults yield rich descriptions of multi-modal, multimedia lifelog content, opening up even greater possibilities for managing and using lifelogs

Developing perennial wildflower strips for use in Mediterranean orchard systems

To support sustainable food production and the delivery of ecosystem services through ecological intensification, wildflower strips have become a popular strategy. Despite their success in temperate orchard systems, they remain understudied in Mediterranean ecosystems, which poses a significant barrier to uptake. In order to further promote their adoption, seed mixes must be optimised for commercial orchard systems and for the Mediterranean climate. Plant species should be selected for their consistent performance, whilst the availability of resources for ecosystem service providers determines the quality of the wildflower strip. In this study, the suitability of 12 native perennial forbs and two tussock-forming grass species for wildflower strips in commercial Citrus orchards was assessed over a 3-year period. Distinct resources for natural enemies according to the different plant growth stages were used an indicator of wildflower strip quality. The wildflower strips were managed under two different cutting strategies: (i) standard management, in which wildflower strips were cut once annually in February, and (ii) active management, in which wildflower strips were cut two additional times each year. The establishment and success of the sown species were compared. The influence of wildflower strips and their management on plant species richness, community structure, and the provision of resources was com -pared with a control treatment, in which alleyways were managed conventionally by cutting any naturally occurring vegetation to a height of ≤5 cm, four to five times annual. For the first time, the performance of native perennial plant species has been assessed in Mediterranean orchard systems and a seed mix developed for targeting pest regulation services. The wildflower strips were successful in increasing plant species richness and the available resources expected to support natural enemies. However, only wildflower strips managed with cutting once annually enhanced vegetation cover relative to the control, whilst extending the flowering period. This study therefore provides crucial tools for the further development of sustainable approaches to food production in Mediterranean orchard systems

Investigation of zeolitic imidazolate frameworks using 13C and 15N solid-state NMR spectroscopy

The authors are grateful to EPSRC computational support through the Collaborative Computational Project on NMR Crystallography (CCP-NC), via EP/M022501/1, and for other support through EP/G062129/1 (JK) and EP/M506631/1 (SS). AFO acknowledges funding from the European Community Seventh Framework Program (FP7/2007-2013 [grant agreement number 608490], Project M4CO2). SEA would also like to thank the Royal Society and Wolfson Foundation for a merit award. AFO would also like to acknowledge the SCI for a scholarship for her PhD studies. Some of the calculations were performed on the ARCHER UK National Supercomputing Service, and were supported by CCP-NC. The research data (and/or materials) supporting this publication can be accessed at http://dx.doi.org/10.17630/7959a81e-161d-4ada-9914-08d3d235ce88Zeolitic imidazolate frameworks (ZIFs) are a subclass of metal-organic frameworks (MOFs) with extended three-dimensional networks of transition metal nodes (bridged by rigid imidazolate linkers), with potential applications in gas storage and separation, sensing and controlled delivery of drug molecules. Here, we investigate the use of 13C and 15N solid-state NMR spectroscopy to characterise the local structure and disorder in a variety of single- and dual-linker ZIFs. In most cases, a combination of a basic knowledge of chemical shifts typically observed in solution-state NMR spectroscopy and the use of dipolar dephasing NMR experiments to reveal information about quaternary carbon species are combined to enable spectral assignment. Accurate measurement of the anisotropic components of the chemical shift provided additional information to characterise the local environment and the possibility of trying to understand the relationships between NMR parameters and both local and long-range structure. First-principles calculations on some of the simpler, ordered ZIFs were possible, and provided support for the spectral assignments, while comparison of these model systems to more disordered ZIFs aided interpretation of the more complex spectra obtained. It is shown that 13C and 15N NMR are sufficiently sensitive to detect small changes in the local environment, e.g., functionalisation of the linker, crystallographic inequivalence and changes to the framework topology, while the relative proportion of each linker present can be obtained by comparing relative intensities of resonances corresponding to chemically-similar species in cross polarisation experiments with short contact times. Therefore, multinuclear NMR spectroscopy, and in particular the measurement of both isotropic and anisotropic parameters, offers a useful tool for the structural study of ordered and, in particular, disordered ZIFs.Publisher PDFPeer reviewe