Implementation and evaluation of simultaneous video-electroencephalography and functional magnetic resonance imaging

The objective of this study was to demonstrate that the addition of simultaneous and synchronised video to electroencephalography (EEG)-correlated functional magnetic resonance imaging (fMRI) could increase recorded information without data quality reduction. We investigated the effect of placing EEG, video equipment and their required power supplies inside the scanner room, on EEG, video and MRI data quality, and evaluated video-EEG-fMRI by modelling a hand motor task. Gradient-echo, echo-planner images (EPI) were acquired on a 3-T MRI scanner at variable camera positions in a test object [with and without radiofrequency (RF) excitation], and human subjects. EEG was recorded using a commercial MR-compatible 64-channel cap and amplifiers. Video recording was performed using a two-camera custom-made system with EEG synchronization. An in-house script was used to calculate signal to fluctuation noise ratio (SFNR) from EPI in test object with variable camera positions and in human subjects with and without concurrent video recording. Five subjects were investigated with video-EEG-fMRI while performing hand motor task. The fMRI time series data was analysed using statistical parametric mapping, by building block design general linear models which were paradigm prescribed and video based. Introduction of the cameras did not alter the SFNR significantly, nor did it show any signs of spike noise during RF off conditions. Video and EEG quality also did not show any significant artefact. The Statistical Parametric Mapping{T} maps from video based design revealed additional blood oxygen level-dependent responses in the expected locations for non-compliant subjects compared to the paradigm prescribed design. We conclude that video-EEG-fMRI set up can be implemented without affecting the data quality significantly and may provide valuable information on behaviour to enhance the analysis of fMRI data

Yield Interactions of Wheat Genotypes to Dates of Seeding in Eastern Mid Hills of Nepal

Wheat (Triticum aestivum L.) is one of the major cereal crops and staple food sources in Nepal. Wheat varieties being popular in mid hill regions are still in the early stages of adoption. Identification of appropriate date of seeding plays important role in enhancing the adoption rate ensuring the sustainable production. Therefore, three dates viz 15th November, 1st and 15th December for seeding and twenty eight wheat genotypes were evaluated in a split plot design with two replications for two consecutive seasons in 2011/12 and 2012/13 at an altitude of 2200 masl of eastern Nepal. The results showed genetic differences and interaction effect of genotypes with the dates of sowing on grain yield, panicle length and effective tillers per square meter. The wheat sown on 1st December showed the highest yield as compared to other sown dates. Similarly, WK1907, WK1911, WK1803, WK1915, WK1909, WK1714 and WK1803 produced highest yield among the tested genotypes with retaining maximum number of effective tillers and posed suitable maturity across all sowing date.Journal of Nepal Agricultural Research Council Vol.1 2015 pp.33-3

Development of a pulsar-based timescale

Using observations of pulsars from the Parkes Pulsar Timing Array (PPTA) project we develop the first pulsar-based timescale that has a precision comparable to the uncertainties in international atomic timescales. Our ensemble of pulsars provides an Ensemble Pulsar Scale (EPS) analogous to the free atomic timescale Echelle Atomique Libre (EAL). The EPS can be used to detect fluctuations in atomic timescales and therefore can lead to a new realisation of Terrestrial Time, TT(PPTA11). We successfully follow features known to affect the frequency of the International Atomic Timescale (TAI) and we find marginally significant differences between TT(PPTA11) and TT(BIPM11). We discuss the various phenomena that lead to a correlated signal in the pulsar timing residuals and therefore limit the stability of the pulsar timescale.Comment: Accepted for publication in MNRA

Milling, Nutritional, Physical and Cooking Properties of Four Basmati Rice Varieties

Rice is one of the most popular staple foods produced contributing higher most in agriculture gross domestic production in Nepal. Thus, nutritional, physicochemical, and cooking properties of rice might interplay important roles in their production and farming practice, therefore, it is inevitable to understand these characteristic features. However, there has been only limited information available on such properties, therefore we aimed to examine nutritional, physicochemical and cooking properties of four Basmati varieties of rice namely Red Basmati, White Basmati, Black Basmati and Pokhareli Basmati. These rice varieties were purchased from different places in Nepal in paddy form. In this study various parameters associated with milling, nutritional, physical and cooking properties were evaluated. To measure protein contents in rice, Kjeldal method was implied. Among the varieties, the protein content was maximum in Red Basmati (7.74%) and minimum in Black Basmati (6.51%). The milled rice percentage and head rice recovery were maximum in Pokhareli Basmati represented by 72.02±0.10 and 67.46±0.42, respectively, while and minimum in White Basmati represented by 68.17±0.50 and 65.11±0.28, respectively. The kernel elongation ratio and volume expansion ratio was maximum in Red Basmati represented by 1.62 and 2.85 respectively. Water uptake ratio was maximum 3.11 in Black Basmati and minimum of 2.18 in Red Basmati. Gruel loss was found lowest 1.05% in Red Basmati and highest represented by 2.40% in Black Basmati. The highest starch iodine blue value of 0.21 was observed in Red Basmati and lowest of 0.12 in Black Basmati. The Red Basmati was found to have the better cooking quality among all varieties

Ultrafast Enhancement of Ferromagnetic Spin Exchange Induced by Ligand-to-Metal Charge Transfer

We theoretically predict and experimentally demonstrate a nonthermal pathway to optically enhance superexchange interaction energies in a material based on exciting ligand-to-metal charge-transfer transitions, which introduces lower-order virtual hopping contributions that are absent in the ground state. We demonstrate this effect in the layered ferromagnetic insulator CrSiTe₃ by exciting Te-to-Cr charge-transfer transitions using ultrashort laser pulses and detecting coherent phonon oscillations that are impulsively generated by superexchange enhancement via magneto-elastic coupling. This mechanism kicks in below the temperature scale where short-range in-plane spin correlations begin to develop and disappears when the excitation energy is tuned away from the charge-transfer resonance, consistent with our predictions

The Parkes Observatory Pulsar Data Archive

The Parkes pulsar data archive currently provides access to 144044 data files obtained from observations carried out at the Parkes observatory since the year 1991. Around 10^5 files are from surveys of the sky, the remainder are observations of 775 individual pulsars and their corresponding calibration signals. Survey observations are included from the Parkes 70cm and the Swinburne Intermediate Latitude surveys. Individual pulsar observations are included from young pulsar timing projects, the Parkes Pulsar Timing Array and from the PULSE@Parkes outreach program. The data files and access methods are compatible with Virtual Observatory protocols. This paper describes the data currently stored in the archive and presents ways in which these data can be searched and downloaded.Comment: Accepted by PAS

Rotation measure variations for 20 millisecond pulsars

We report on variations in the mean position angle of the 20 millisecond pulsars being observed as part of the Parkes Pulsar Timing Array (PPTA) project. It is found that the observed variations are dominated by changes in the Faraday rotation occurring in the Earth's ionosphere. Two ionospheric models are used to correct for the ionospheric contribution and it is found that one based on the International Reference Ionosphere gave the best results. Little or no significant long-term variation in interstellar RM was found with limits typically about 0.1 rad m$^{-2}$ yr$^{-1}$ in absolute value. In a few cases, apparently significant RM variations over timescales of a few 100 days or more were seen. These are unlikely to be due to localised magnetised regions crossing the line of sight since the implied magnetic fields are too high. Most probably they are statistical fluctuations due to random spatial and temporal variations in the interstellar electron density and magnetic field along the line of sight.Comment: Accepted for publication in Astrophysics & Space Scienc