The mass of the very massive binary WR21a

We present multi-epoch spectroscopic observations of the massive binary system WR21a, which include the January 2011 periastron passage. Our spectra reveal multiple SB2 lines and facilitate an accurate determination of the orbit and the spectral types of the components. We obtain minimum masses of $64.4\pm4.8 \ M_{\odot}$ and $36.3\pm1.7 \ M_{\odot}$ for the two components of WR21a. Using disentangled spectra of the individual components, we derive spectral types of O3/WN5ha and O3Vz~((f*)) for the primary and secondary, respectively. Using the spectral type of the secondary as an indication for its mass, we estimate an orbital inclination of $i=58.8\pm2.5^{\mathrm{o}}$ and absolute masses of $103.6\pm10.2 \ M_{\odot}$ and $58.3\pm3.7 \ M_{\odot}$, in agreement with the luminosity of the system. The spectral types of the WR21a components indicate that the stars are very young (1$-$2 Myr), similar to the age of the nearby Westerlund 2 cluster. We use evolutionary tracks to determine the mass-luminosity relation for the total system mass. We find that for a distance of 8 kpc and an age of 1.5 Myr, the derived absolute masses are in good agreement with those from evolutionary predictions.Comment: 7 pages, 4 figures; accepted for publication in MNRA

Globally controlled quantum wires for perfect qubit transport, mirroring and computing

It is expected that quantum wires (q-wires), will be required to transport quantum information within many quantum computer implementations. Here we describe a new design for a q-wire with perfect transmission using a uniformly coupled Ising spin chain subject to global (homogeneously-applied) pulses. Besides allowing for perfect transport of single qubits, the design also yields the perfect ``mirroring'' of multiply encoded qubits within the wire. We further utilise this global-pulse generated perfect mirror operation as a ``clock cycle'' to perform universal quantum computation on these multiply encoded qubits. We demonstrate the operation of single and two-qubit quantum logic gates and show that only $N-1$ complete mirror cycles are required to execute a quantum Fourier transform on $N$ qubits encoded within the q-wire.Comment: Shortened 5 pages, 4 figure

Quantum metrology with molecular ensembles

This work was supported by the EPSRC through QIP IRC (Grants No. GR/S82176/01 and No. GR/S15808/01), the National Research Foundation and Ministry of Education, Singapore, the DAAD, and the Royal Society.The field of quantum metrology promisesmeasurement devices that are fundamentally superior to conventional technologies. Specifically, when quantum entanglement is harnessed, the precision achieved is supposed to scale more favorably with the resources employed, such as system size and time required. Here, we consider measurement of magnetic-field strength using an ensemble of spin-active molecules. We identify a third essential resource: the change in ensemble polarization (entropy increase) during the metrology experiment. We find that performance depends crucially on the form of decoherence present; for a plausible dephasing model, we describe a quantum strategy, which can indeed beat the standard strategy.Publisher PDFPeer reviewe

Ensemble based quantum metrology

The field of quantum metrology promises measurement devices that are fundamentally superior to conventional technologies. Specifically, when quantum entanglement is harnessed the precision achieved is supposed to scale more favourably with the resources employed, such as system size and the time required. Here we consider measurement of magnetic field strength using an ensemble of spins, and we identify a third essential resource: the initial system polarisation, i.e. the low entropy of the original state. We find that performance depends crucially on the form of decoherence present; for a plausible dephasing model, we describe a quantum strategy which can indeed beat the standard quantum limit

The evaluation of Education Maintenance Allowance Pilots: three years' evidence: a quantitative evaluation

This is the third report of the longitudinal quantitative evaluation of Education Maintenance Allowance (EMA) pilots and the first since the government announced that EMA is to be rolled out nationally from 2004. The evaluation was commissioned in 1999, by the Department for Education and Skills (DfES) from a consortium of research organisations, led by the Centre for Research in Social Policy (CRSP) and including the National Centre for Social Research, the Institute for Fiscal Studies (IFS) and the National Institute for Careers Education and Counselling (NICEC). The statistical evaluation design is a longitudinal cohort study involving large random sample surveys of young people (and their parents) in 10 EMA pilot areas and eleven control areas. Two cohorts of young people were selected from Child Benefit records. The first cohort of young people left compulsory schooling in the summer of 1999 and they, and their parents, were interviewed between October 1999 and April 2000 (Year 12 interview). A second interview was carried out with these young people between October 2000 and April 2001 (Year 13 interview). The second cohort left compulsory education the following summer of 2000 and young people, and their parents, were first interviewed between October 2000 and April 2001. The report uses both propensity score matching (PSM) and descriptive techniques, each of which brings their own particular strengths to the analysis

Co-Administration of Iron and a Bioavailable Curcumin Supplement Increases Serum BDNF Levels in Healthy Adults

Brain-derived neurotrophic factor (BDNF) is key for the maintenance of normal neuronal function and energy homeostasis and has been suggested to improve cognitive function, including learning and memory. Iron and the antioxidant curcumin have been shown to influence BDNF homeostasis. This 6-week, double blind, randomized, placebo-controlled study examined the effects of oral iron supplementation at low (18 mg) and high (65 mg) ferrous (FS) iron dosages, compared to a combination of these iron doses with a bioavailable formulated form of curcumin (HydroCurcTM; 500 mg) on BDNF levels in a healthy adult cohort of 155 male (26.42 years ± 0.55) and female (25.82 years ± 0.54) participants. Participants were randomly allocated to five different treatment groups: both iron and curcumin placebo (FS0+Plac), low dose iron and curcumin placebo (FS18+Plac), low dose iron and curcumin (FS18+Curc), high dose iron and curcumin placebo (FS65+Plac) and high dose iron and curcumin (FS65+Curc). Results showed a significant increase in BDNF over time (26%) in the FS18+Curc group (p = 0.024), and at end-point between FS18+Curc and FS18+Plac groups (35%, p = 0.042), demonstrating for the first time that the combination with curcumin, rather than iron supplementation alone, results in increased serum BDNF. The addition of curcumin to iron supplementation may therefore provide a novel approach to further enhance the benefits associated with increased BDNF levels

Effects of 5 Different Finger Rest Positions on Arm Muscle Activity During Scaling by Dental Hygiene Students

Purpose. This study was conducted to determine the effects of 5 different finger rest positions: opposite arch, standard intraoral, basic extraoral, cross arch, and finger on finger on the muscle activity of 4 forearm muscles (extensor carpi radialis longus, flexor carpi ulnaris, biceps brachii, and pronator teres) during a simulated periodontal scaling experience. Methods. A convenience sample of 32 consenting senior dental hygiene students who met inclusion criteria participated. Using a 4 x 5 counter-balanced research design, each participant used a Gracey 11/12 curet to scale one cc of artificial calculus from first permanent molar typodont teeth (#3,14,19,30). Five different typodonts were set up for each participant with fulcrums randomly assigned for use on each typodont. While scaling, the participant’s muscle activity was measured by surface electromyography. Two-way analysis of variance with repeated measures was used to determine if significant differences existed in the amount of muscle activity generated with each fulcrum. Results. Results revealed no statistically significant interaction effect between area of the mouth scaled, muscle activity, and fulcrum used. Similar muscle activity was produced throughout the mouth regardless of the fulcrum used. The upper right quadrant produced the most muscle activity (p= 0.0101) and the lower left quadrant produced the least (p=\u3c .0001). When comparing the overall muscle activity generated with each fulcrum, only the cross arch fulcrum when compared to the opposite fulcrum produced statistically significant results (p=0.0110). Conclusions. Based on the results, similar muscle activity is produced when using any of the 5 fulcrums in each quadrant of the mouth. Clinicians appear to experience minimal ergonomic advantage in terms of fulcrums used and area of the mouth scaled during a simulated scaling experience

The E-ELT Multi-Object Spectrograph: latest news from MOSAIC

There are 8000 galaxies, including 1600 at z larger than 1.6, which could be simultaneously observed in an E-ELT field of view of 40 sq. arcmin. A considerable fraction of astrophysical discoveries require large statistical samples, which can only be obtained with multi-object spectrographs (MOS). MOSAIC will provide a vast discovery space, enabled by a multiplex of 200 and spectral resolving powers of R=5000 and 20000. MOSAIC will also offer the unique capability of more than 10 "high-definition" (multi-object adaptive optics, MOAO) integral-field units, optimised to investigate the physics of the sources of reionization. The combination of these modes will make MOSAIC the world-leading MOS facility, contributing to all fields of contemporary astronomy, from extra-solar planets, to the study of the halo of the Milky Way and its satellites, and from resolved stellar populations in nearby galaxies out to observations of the earliest "first-light" structures in the Universe. It will also study the distribution of the dark and ordinary matter at all scales and epochs of the Universe. Recent studies of critical technical issues such as sky-background subtraction and MOAO have demonstrated that such a MOS is feasible with state-of-the-art technology and techniques. Current studies of the MOSAIC team include further trade-offs on the wavelength coverage, a solution for compensating for the non-telecentric new design of the telescope, and tests of the saturation of skylines especially in the near-IR bands. In the 2020s the E-ELT will become the world's largest optical/IR telescope, and we argue that it has to be equipped as soon as possible with a MOS to provide the most efficient, and likely the best way to follow-up on James Webb Space Telescope (JWST) observations.Comment: 10 pages, 3 Figures, in Ground-based and Airborne Instrumentation for Astronomy VI, 2016, Proc. SPI

Rhesus Macaques Form Preferences for Brand Logos Through Sex and Social Status Based Advertising

Like humans, monkeys value information about sex and status, inviting the hypothesis that our susceptibility to these factors in advertising arises from shared, ancestral biological mechanisms that prioritize social information. To test this idea, we asked whether rhesus macaques (Macaca mulatta) show choice behavior that is similar to humans in response to sex and social status in advertising. Our results show that monkeys form preferences for brand logos repeatedly paired with images of macaque genitals and high status monkeys. Moreover, monkeys sustain preferences for these brand logos even though choosing them provided no tangible rewards, a finding that cannot be explained by a decision mechanism operating solely on material outcomes. Together, our results endorse the hypothesis that the power of sex and status in advertising emerges from the spontaneous engagement of shared, ancestral neural circuits that prioritize information useful for navigating the social environment. Finally, our results show that simple associative conditioning is sufficient to explain the formation of preferences for brand logos paired with sexual or status-based images

Optimisation of classification methods to differentiate morphologically-similar pollen grains from FT-IR spectra

A growing body of research is demonstrating the potential of Fourier-Transform Infrared spectroscopy (FT-IR) to identify and differentiate morphologically similar pollen taxa. The Poaceae (grass) family is a large and complex with morphologically similar pollen grains. It is not possible to use traditional light microscopy to differentiate Poaceae species, or genus, based on pollen morphological characteristics. This research presents a study of five species from the Poaceae family found across a wide variety of different moorland vegetation communities, to test the extent to which FT-IR microspectroscopy can be used to separate and identify these species and develop statistical approaches for the analyses of these data. Moorland grasses are of particular importance to assess conservation status and baselines in fragile and scarce vegetation communities, whose vegetation composition in the past remains cryptic owing to low taxonomic resolution. Non-differentiated and second derivative spectra were combined with Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) to determine whether species had different chemical compositions and would cluster. Decision trees and random forest were used to classify each species and demonstrated 100% successful classification rate. This success demonstrates that using FT-IR microspectroscopy alongside spectral pre-processing and multivariate analysis can successfully identify and separate these moorland Poaceae species and has the clear potential to improve taxonomic resolution and classification of fossil pollen records. This will improve our understanding of how past land-use practice has shaped upland communities, provide more detailed ecologically-relevant palaeoecological information, and be utilised for the restoration and conservation of upland habitats