Boron nitride nanotubes : pronounced resistance to oxidation

Boron nitride (BN) nanotubes have the same nanostructure as carbon nanotubes but are found to exhibit significant resistance to oxidation at high temperatures. Our systematic study has revealed that BN nanotubes are stable at 700 &deg;C in air and that some thin nanotubes (diameter less than 20 nm) with perfect multiwalled cylindrical structure can survive up to 900 &deg;C. Thermogravimetric analysis reveals an onset temperature for oxidation of BN nanotubes of 800 &deg;C compared with only 400 &deg;C for carbon nanotubes under the same conditions. This more pronounced resistance of BN nanotubes to oxidation is inherited from the hexagonal BN and also depends on the nanocrystalline structure. This high level of resistance to oxidation allows promising BN nanotube applications athigh temperatures<br /

Stock assessment of the Queensland and New South Wales pearl perch (Glaucosoma scapulare) fishery

Pearl perch (Glaucosoma scapulare) are found commonly in sub-tropical offshore-waters along the east coast of Australia and are a valuable table fish popular with commercial and recreational fishers. The species is long-lived, up to 30 years of age, and reaches sexual maturity at between 25 and 35 cm total length. Pearl perch are predominantly line-caught and fishing is managed separately by New South Wales (NSW) and Queensland. Historical fishing data indicate that pearl perch harvests have been consistently higher from Queensland waters with 73% of the total catch landed in Queensland in 2013. Approximately 52% of the Queensland catch is taken by recreational fishers compared with 42% in NSW. In Queensland, the Department of Agriculture and Fisheries (DAF) recently classified the stock status of pearl perch as “transitional depleting” (DAF Stock Status 2015). The status raised concern in both Queensland and NSW as to whether current management arrangements are adequate to protect the sustainability of pearl perch fishery. This stock assessment incorporates data from both jurisdictions and assesses at the whole of stock level; establishes current stock status reference points including biomass and fishing pressure levels for pearl perch; and provides advice on whether additional management measures are required to reduce fishing pressure and rebuild fish stocks

Environmental and genetic factors associated with Solanesol accumulation in potato leaves

Solanesol is a high value 45-carbon, unsaturated, all-trans-nonaprenol isoprenoid. Recently solanesol has received particular attention because of its utility, both in its own right and as a precursor in the production of numerous compounds used in the treatment of disease states. Solanesol is found mainly in solanaceous crops such as potato, tomato, tobacco and pepper where it accumulates in the foliage. There is considerable potential to explore the extraction of solanesol from these sources as a valuable co-product. In this study we have characterised the genetic variation in leaf solanesol content in a biparental, segregating diploid potato population. We demonstrate that potato leaf solanesol content is genetically controlled and identify several quantitative trait loci associated with leaf solanesol content. Transient over-expression of genes from the methylerythritol 4-phosphate (MEP) and mevalonic acid (MVA) pathways, either singly or in combination, resulted in enhanced accumulation of solanesol in leaves of Nicotiana benthamiana, providing insights for genetically engineering the pathway. We also demonstrate that in potato, leaf solanesol content is enhanced by up to six-fold on exposure to moderately elevated temperature and show corresponding changes in expression patterns of MEP and MVA genes. Our combined approaches offer new insights into solanesol accumulation and strategies for developing a bio-refinery approach to potato production

Non-Linear N-Parameter Spacetime Perturbations: Gauge Transformations

We introduce N-parameter perturbation theory as a new tool for the study of non-linear relativistic phenomena. The main ingredient in this formulation is the use of the Baker-Campbell-Hausdorff formula. The associated machinery allows us to prove the main results concerning the consistency of the scheme to any perturbative order. Gauge transformations and conditions for gauge invariance at any required order can then be derived from a generating exponential formula via a simple Taylor expansion. We outline the relation between our novel formulation and previous developments.Comment: 7 pages, no figures, RevTeX 4.0. Revised version to match version published in PR

Polls and elections: Is Loyalty a Powerful Thing? Republican Senate Campaign Strategy and Trump Coattails in the 2016 Election

Presidential candidates provide a boost to their congressional candidate counterparts, in which congressional candidates should ride the proverbial coattails into office (Campbell and Sumners 1990; Stewart 1989). The 2016 election, however, provides an instance in which the presidential coattails were less than desirable. In this article, we argue that state politics determines the optimal strategy for how candidates should position themselves vis‐à‐vis a controversial presidential candidate. Based on our findings, voters rewarded candidates at varying levels for distancing themselves from then candidate Trump. Specifically, the disloyal strategy, in which candidates completely disavowed Trump, worked best in swing states and among Democrats, liberals, and Clinton voters. The ambiguous strategy, in which candidates took an unclear position on Trump, was less effective, but still received gains in appeal among independents and liberals

Neutron diffraction study of the magnetic order in NdMn2Ge1.6Si0.4

Here we report a detailed investigation of NdMn2Ge1.6Si0.4; this forms part of our investigation of the magnetic order across the NdMn2Ge2−xSix (x = 0–2.0) series by magnetometry, x-ray diffraction and neutron diffraction over the temperature range 6–465 K. On decreasing the temperature from 465 K, NdMn2Ge1.6Si0.4 exhibits four magnetic transitions: (i) from paramagnetism to intralayer antiferromagnetism AFl at TIntraN ~ 430 K; (ii) AFl to canted ferromagnetism Fmc at TInterC ~ 330 K; (iii) Fmc to conical magnetic ordering of the Mn sublattice Fmi at Tcc ~ 178 K and (iv) Fmi(Mn) to Fmi(Mn)+F(Nd) at TNdC ~ 72 K

Measuring the effects of fractionated radiation therapy in a 3D prostate cancer model system using SERS nanosensors.

Multicellular tumour spheroids (MTS) are three-dimensional cell cultures that possess their own microenvironments and provide a more meaningful model of tumour biology than monolayer cultures. As a result, MTS are becoming increasingly used as tumor models when measuring the efficiency of therapies. Monitoring the viability of live MTS is complicated by their 3D nature and conventional approaches such as fluorescence often require fixation and sectioning. In this paper we detail the use of Surface Enhanced Raman Spectroscopy (SERS) to measure the viability of MTS grown from prostate cancer (PC3) cells. Our results show that we can monitor loss of viability by measuring pH and redox potential in MTS and furthermore we demonstrate that SERS can be used to measure the effects of fractionation of a dose of radiotherapy in a way that has potential to inform treatment planning.EaStCHEM, NHS Lothian, Jamie King Cancer Research FundThis is the final version of the article. It first appeared from the Royal Society of Chemistry via http://dx.doi.org/10.1039/C6AN01032

Charged black holes in effective string theory

We investigate the qualitative new features of charged dilatonic black holes which emerge when both the Yang-Mills and Gauss-Bonnet curvature corrections are included in the effective action. We consider perturbative effects by an expansion up to second order in the inverse string tension on the four dimensional Schwarzschild background and determine the backreaction. We calculate the thermodynamical functions and show that for magnetic charge above a critical value, the temperature of the black hole has a maximum and goes to zero for a finite value of the mass. This indicates that the conventional Hawking evaporation law is modified by string theory at a classical level.Comment: 17 pages, 5 figures not included, plain Te

The NASA Micro Pulse Lidar Network (MPLNET): Introduction of the New Version 3 Release

The NASA Micro-Pulse Lidar Network (MPLNET) is a global federated network of polarized Micro-Pulse Lidar (MPL) systems running continuously. MPLNET began in 2000, and there have been over 70 sites deployed worldwide, with 24 sites currently active and a few more planned over the next year. Seven of the long-term sites have 10+ years of data, and many more have 5+ years. Most sites are co-located with AERONET providing joint data on column and vertically resolved aerosol and cloud information. This presentation will introduce our new Version 3 MPLNET data. All sites in the network now feature eye-safe polarized backscatter MPL instruments, providing information on attenuated backscatter and particle shape. In addition to change with our signal data, we have an enhanced cloud product suite, a new PBL height product, and inclusion of the new AERONET lunar aerosol optical depth into MPLNET aerosol retrievals. A new quality flag process will be used to better describe all data products. Finally, a new data portal will provide near-real-time (NRT) access to all data products, including new quality assured NRT L1.5 products. Custom products developed for model specific applications will also be provided

Overview of MPLNET Version 3 Cloud Detection

The National Aeronautics and Space Administration Micro Pulse Lidar Network, version 3, cloud detection algorithm is described and differences relative to the previous version are highlighted. Clouds are identified from normalized level 1 signal profiles using two complementary methods. The first method considers vertical signal derivatives for detecting low-level clouds. The second method, which detects high-level clouds like cirrus, is based on signal uncertainties necessitated by the relatively low signal-to-noise ratio exhibited in the upper troposphere by eye-safe network instruments, especially during daytime. Furthermore, a multitemporal averaging scheme is used to improve cloud detection under conditions of a weak signal-to-noise ratio. Diurnal and seasonal cycles of cloud occurrence frequency based on one year of measurements at the Goddard Space Flight Center (Greenbelt, Maryland) site are compared for the new and previous versions. The largest differences, and perceived improvement, in detection occurs for high clouds (above 5 km, above MSL), which increase in occurrence by over 5%. There is also an increase in the detection of multilayered cloud profiles from 9% to 19%. Macrophysical properties and estimates of cloud optical depth are presented for a transparent cirrus dataset. However, the limit to which the cirrus cloud optical depth could be reliably estimated occurs between 0.5 and 0.8. A comparison using collocated CALIPSO measurements at the Goddard Space Flight Center and Singapore Micro Pulse Lidar Network (MPLNET) sites indicates improvements in cloud occurrence frequencies and layer heights