Representation of Instantaneous and Short-Term Loudness in the Human Cortex.

Acoustic signals pass through numerous transforms in the auditory system before perceptual attributes such as loudness and pitch are derived. However, relatively little is known as to exactly when these transformations happen, and where, cortically or sub-cortically, they occur. In an effort to examine this, we investigated the latencies and locations of cortical entrainment to two transforms predicted by a model of loudness perception for time-varying sounds: the transforms were instantaneous loudness and short-term loudness, where the latter is hypothesized to be derived from the former and therefore should occur later in time. Entrainment of cortical activity was estimated from electro- and magneto-encephalographic (EMEG) activity, recorded while healthy subjects listened to continuous speech. There was entrainment to instantaneous loudness bilaterally at 45, 100, and 165 ms, in Heschl's gyrus, dorsal lateral sulcus, and Heschl's gyrus, respectively. Entrainment to short-term loudness was found in both the dorsal lateral sulcus and superior temporal sulcus at 275 ms. These results suggest that short-term loudness is derived from instantaneous loudness, and that this derivation occurs after processing in sub-cortical structures.This work was supported by an ERC Advanced Grant (230570, ‘Neurolex’) to WMW, and by MRC Cognition and Brain Sciences Unit (CBU) funding to WMW (U.1055.04.002.00001.01). Computing resources were provided by the MRC-CBU.This is the final version of the article. It first appeared from Frontiers via http://dx.doi.org/10.3389/fnins.2016.0018

Tracking cortical entrainment in neural activity: auditory processes in human temporal cortex.

A primary objective for cognitive neuroscience is to identify how features of the sensory environment are encoded in neural activity. Current auditory models of loudness perception can be used to make detailed predictions about the neural activity of the cortex as an individual listens to speech. We used two such models (loudness-sones and loudness-phons), varying in their psychophysiological realism, to predict the instantaneous loudness contours produced by 480 isolated words. These two sets of 480 contours were used to search for electrophysiological evidence of loudness processing in whole-brain recordings of electro- and magneto-encephalographic (EMEG) activity, recorded while subjects listened to the words. The technique identified a bilateral sequence of loudness processes, predicted by the more realistic loudness-sones model, that begin in auditory cortex at ~80 ms and subsequently reappear, tracking progressively down the superior temporal sulcus (STS) at lags from 230 to 330 ms. The technique was then extended to search for regions sensitive to the fundamental frequency (F0) of the voiced parts of the speech. It identified a bilateral F0 process in auditory cortex at a lag of ~90 ms, which was not followed by activity in STS. The results suggest that loudness information is being used to guide the analysis of the speech stream as it proceeds beyond auditory cortex down STS toward the temporal pole.This work was supported by an EPSRC grant to William D. Marslen-Wilson and Paula Buttery (EP/F030061/1), an ERC Advanced Grant (Neurolex) to William D. Marslen-Wilson, and by MRC Cognition and Brain Sciences Unit (CBU) funding to William D. Marslen-Wilson (U.1055.04.002.00001.01). Computing resources were provided by the MRC-CBU and the University of Cambridge High Performance Computing Service (http://www.hpc.cam.ac.uk/). Andrew Liu and Phil Woodland helped with the HTK speech recogniser and Russell Thompson with the Matlab code. We thank Asaf Bachrach, Cai Wingfield, Isma Zulfiqar, Alex Woolgar, Jonathan Peelle, Li Su, Caroline Whiting, Olaf Hauk, Matt Davis, Niko Kriegeskorte, Paul Wright, Lorraine Tyler, Rhodri Cusack, Brian Moore, Brian Glasberg, Rik Henson, Howard Bowman, Hideki Kawahara, and Matti Stenroos for invaluable support and suggestions.This is the final published version. The article was originally published in Frontiers in Computational Neuroscience, 10 February 2015 | doi: 10.3389/fncom.2015.0000

Multi-mode Combustion Process Monitoring on a Pulverised Fuel Combustion Test Facility based on Flame Imaging and Random Weight Network Techniques

Combustion systems need to be operated under a range of different conditions to meet fluctuating energy demands. Reliable monitoring of the combustion process is crucial for combustion control and optimisation under such variable conditions. In this paper, a monitoring method for variable combustion conditions is proposed by combining digital imaging, PCA-RWN (Principal Component Analysis and Random Weight Network) techniques. Based on flame images acquired using a digital imaging system, the mean intensity values of RGB (Red, Green, and Blue) image components and texture descriptors computed based on the grey-level co-occurrence matrix are used as the colour and texture features of flame images. These features are treated as the input variables of the proposed PCA-RWN model for multi-mode process monitoring. In the proposed model, the PCA is used to extract the principal component features of input vectors. By establishing the RWN model for an appropriate principal component subspace, the computing load of recognising combustion operation conditions is significantly reduced. In addition, Hotelling’s T2 and SPE (Squared Prediction Error) statistics of the corresponding operation conditions are calculated to identify the abnormalities of the combustion. The proposed approach is evaluated using flame image datasets obtained on a 250 kWth air- and oxy-fuel Combustion Test Facility. Variable operation conditions were achieved by changing the primary air and SA/TA (Secondary Air to Territory Air) splits. The results demonstrate that, for the operation conditions examined, the condition recognition success rate of the proposed PCA-RWN model is over 91%, which outperforms other machine learning classifiers with a reduced training time. The results also show that the abnormal conditions exhibit different oscillation frequencies from the normal conditions, and the T2 and SPE statistics are capable of detecting such abnormalities

Additive technology for pollutant control and efficient coal combustion

High efficiency and low emissions from pf coal power stations has been the drive behind the development of present and future efficient coal combustion technologies. Upgrading coal, capturing CO2, reducing emission of NOx, SO2 and particulate matter, mitigating slagging, fouling and corrosion are the key initiatives behind these efficient coal technologies. This study focuses on a newly developed fuel additive (Silanite™) based efficient coal combustion technology, which addresses most of the aforementioned key points. Silanite™ a finely milled multi-oxide additive when mixed with the coal without the need to change the boiler installation has proven to increase the boiler efficiency, flame temperature with reduction in corrosion, NOx and particulate matter (dust) emissions. The process has been developed through bench, pilot (100kW) and full scale (233 MWth). The process has been found to have a number of beneficial effects that add up to a viable retrofit to existing power plant as demonstrated on the 233MWth boiler tests (under BS EN 12952-15:2003 standard

LES and RANS of air and oxy-coal combustion in a pilot-scale facility: predictions of radiative heat transfer

The development of carbon capture and storage (CCS) technology is important to permit the use of fossil fuels while honouring commitments to curb greenhouse gas emissions. Coal is a valuable global resource, which is widely available around the world, however its detrimental e ect on climate change will limit its use in a future with strict controls over carbon emissions. Oxyfuel combustion is a promising CCS technology that is being actively pursued in the development of large scale demonstration projects. Under the oxyfuel process for CCS, the combustion gas is replaced with a mixture of recycled ue gas and enriched oxygen. The resulting combustion environment can vary signi cantly from traditional air- red combustion. The development of modelling capabilities will greatly improve the optimisation process to develop oxyfuel technology into an economically viable prospect. This study evaluates the use of large eddy simulation (LES) and Reynoldsaveraged Navier Stokes (RANS) models on the prediction of thermal radiation during coal combustion for both air- red and oxyfuel operation in a pilot-scale 250 kWth furnace. The furnace is part of the UKCCSRC Pilot-scale Advanced Capture Technology (PACT) facilities and was designed for detailed analysis of the combustion process. Two radiation models were evaluated during the RANS calculations, the widely used weighted sum of grey gases (WSGG) andthe full-spectrum correlated k (FSCK) model, while the LES case was calculated using the FSCK radiation model. The results show that the LES solutions are in better agreement with measured values than the RANS predictions for both air- red and oxyfuel coal combustion, however LES demands considerably more computational resources

Hadaean to Palaeoarchaean stagnant-lid tectonics revealed by zircon magnetism.

Plate tectonics is a fundamental factor in the sustained habitability of Earth, but its time of onset is unknown, with ages ranging from the Hadaean to Proterozoic eons1-3. Plate motion is a key diagnostic to distinguish between plate and stagnant-lid tectonics, but palaeomagnetic tests have been thwarted because the planet's oldest extant rocks have been metamorphosed and/or deformed4. Herein, we report palaeointensity data from Hadaean-age to Mesoarchaean-age single detrital zircons bearing primary magnetite inclusions from the Barberton Greenstone Belt of South Africa5. These reveal a pattern of palaeointensities from the Eoarchaean (about 3.9 billion years ago (Ga)) to Mesoarchaean (about 3.3 Ga) eras that is nearly identical to that defined by primary magnetizations from the Jack Hills (JH; Western Australia)6,7, further demonstrating the recording fidelity of select detrital zircons. Moreover, palaeofield values are nearly constant between about 3.9 Ga and about 3.4 Ga. This indicates unvarying latitudes, an observation distinct from plate tectonics of the past 600 million years (Myr) but predicted by stagnant-lid convection. If life originated by the Eoarchaean8, and persisted to the occurrence of stromatolites half a billion years later9, it did so when Earth was in a stagnant-lid regime, without plate-tectonics-driven geochemical cycling

Phosphorylation of bacterial-type phosphoenolpyruvate carboxylase at Ser425 provides a further tier of enzyme control in developing castor oil seeds

PEPC [PEP (phosphoenolpyruvate) carboxylase] is a tightly controlled anaplerotic enzyme situated at a pivotal branch point of plant carbohydrate metabolism. Two distinct oligomeric PEPC classes were discovered in developing COS (castor oil seeds). Class-1 PEPC is a typical homotetramer of 107 kDa PTPC (plant-type PEPC) subunits, whereas the novel 910-kDa Class-2 PEPC hetero-octamer arises from a tight interaction between Class-1 PEPC and 118 kDa BTPC (bacterial-type PEPC) subunits. Mass spectrometric analysis of immunopurified COS BTPC indicated that it is subject to in vivo proline-directed phosphorylation at Ser425. We show that immunoblots probed with phosphorylation site-specific antibodies demonstrated that Ser425 phosphorylation is promoted during COS development, becoming maximal at stage IX (maturation phase) or in response to depodding. Kinetic analyses of a recombinant, chimaeric Class-2 PEPC containing phosphomimetic BTPC mutant subunits (S425D) indicated that Ser425 phosphorylation results in significant BTPC inhibition by: (i) increasing its Km(PEP) 3-fold, (ii) reducing its I50 (L-malate and L-aspartate) values by 4.5- and 2.5-fold respectively, while (iii) decreasing its activity within the physiological pH range. The developmental pattern and kinetic influence of Ser425 BTPC phosphorylation is very distinct from the in vivo phosphorylation/activation of COS Class-1 PEPC's PTPC subunits at Ser11. Collectively, the results establish that BTPC's phospho-Ser425 content depends upon COS developmental and physiological status and that Ser425 phosphorylation attenuates the catalytic activity of BTPC subunits within a Class-2 PEPC complex. To the best of our knowledge, this study provides the first evidence for protein phosphorylation as a mechanism for the in vivo control of vascular plant BTPC activity

Geology and combustion perspectives of Pakistani coals from Salt Range and Trans Indus Range

Abundant availability of low rank coals in some developing countries has a great potential for socio-economic development. Pakistan, as a developing country, has taken a number of initiatives some of which are at an advanced stage. Thus, a critical study of regional and local geology of Salt Range and Trans Indus Range coals located in the Kohat–Potwar geologic province is presented in this paper. Permian coal is the oldest coal, which is located in the Western Salt Range in limited quantity while Palaeocene coal is the younger coal and it is mined from the Hangu and Patala formations. The Palaeocene coal is available in abundance and is mined in the Eastern and Central parts of the Salt Range and Trans Indus Range. Additionally, this study presents the thermo-chemical analyses of the coal samples collected from thirty coal mines of Salt Range and Trans Indus Range. The samples were analyzed for ash composition, ash fusion temperatures (AFT), proximate analysis, ultimate analysis and calorific value from two different Labs, i.e. SGS Pakistan and Changsha University of Science and Technology (CUST), China. The average AFT of the samples analyzed is > 1350 °C, which reveals that the coal is non-slagging. On average the coal has low slagging index, medium fouling index, good combustion characteristic parameters and indices. The coal samples have high ash (14–50%), ultra-high sulfur (3.3–11.1%), low moisture (3–10%), high volatile matter (VM, 24–41%), low carbon (23–57%) with low to medium gross calorific value (GCV, 10.2–25.7 MJ/kg). The data gathered from an extensive campaign is compared with the already published data. The study has provided a knowledge on utilization of coal reserves to meet the projected energy demand in Pakistan as well as in other developing countries