Complexity and lack of standardization have mostly limited the use of event-related potentials (ERPs) and quantitative EEG (QEEG) biomarkers in drug development to small early phase trials. We ...present results from a clinical study on healthy volunteers (HV) and patients with schizophrenia (SZ) that assessed test-retest, group differences, variance, and correlation with functional assessments for ERP and QEEG measures collected at clinical and commercial trial sites with standardized instrumentation and methods, and analyzed through an automated data analysis pipeline.
81 HV and 80 SZ were tested at one of four study sites. Subjects were administered two ERP/EEG testing sessions on separate visits. Sessions included a mismatch negativity paradigm, a 40 Hz auditory steady-state response paradigm, an eyes-closed resting state EEG, and an active auditory oddball paradigm. SZ subjects were also tested on the Brief Assessment of Cognition (BAC), Positive and Negative Syndrome Scale (PANSS), and Virtual Reality Functional Capacity Assessment Tool (VRFCAT).
Standardized ERP/EEG instrumentation and methods ensured few test failures. The automated data analysis pipeline allowed for near real-time analysis with no human intervention. Test-retest reliability was fair-to-excellent for most of the outcome measures. SZ subjects showed significant deficits in ERP and QEEG measures consistent with published academic literature. A subset of ERP and QEEG measures correlated with functional assessments administered to the SZ subjects.
With standardized instrumentation and methods, complex ERP/EEG testing sessions can be reliably performed at clinical and commercial trial sites to produce high-quality data in near real-time.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
A programmable borehole measurement system was deployed in hot water drilled ice holes during the ‘Bed Access and Monitoring of Ice Sheet History’ (BEAMISH) project to drill to the bed of the Rutford ...Ice Stream in West Antarctica. This system operates autonomously (no live data) after deployment, and records borehole diameter (non-contact measurement), water column pressure, heading and inclination. Three cameras, two sideways looking and one vertical, are also included for visual inspection of hole integrity and sediments. The system is small, lightweight (~35.5 kg) and low power using only 6 ‘D’ cell sized lithium batteries, making it ideal for transport and use in remote field sites. The system is 2.81 m long and 165 mm in diameter, and can be deployed attached to the drill hose for measurements during drilling or on its own deployment line afterwards. The full system is discussed in detail, highlighting design strengths and weaknesses. Data from the BEAMISH project are also presented in the form of camera images showing hole integrity, and sensor data used to calculate borehole diameter through the full length of the hole. These data are used to show confidence in hole verticality and subsurface cavity development and connection.
The frequently stated problem of under‐delivery in oil and gas exploration is largely due to overprediction in the volumetric size of prospects rather than to the misinterpretation of risk. In an ...effort to deal with the significant degree of uncertainty inherent in sub‐surface evaluations, the standard method involves building a stochastic volumetric model of the potential container by choosing distributions and probabilities of the gross rock volume, the simulated column height, and the average 3D net/gross, as well as of other reservoir and fluid parameters. Unfortunately, prior to drilling, the three main inputs to the model are difficult to constrain as they are closely tied to the seismic interpretation rather than to historical information. By contrast, a source of hard data is available from existing discoveries and wells in the form of statistics for the play or analogue play, the most useful of which are: (i) the footprint area of the discoveries; (ii) the properties of net reservoir, encapsulated in an area yield parameter MMboe/km2; and (iii) the downside size of the discoveries, specifically the inferred P99 recoverable resource. In this paper, we propose a method called Prospect Area Yield (PAY) to assess the potential size of an exploration prospect which simply integrates these statistical data with the most reliable information from seismic mapping. The main step involves calculating an upside volume by multiplying a mid‐case MMboe/km2 yield with a mapped reasonable closure area for the prospect. This upside volume is assigned a probability which is currently assumed to be P10, implying that 90% of discovery outcomes will be smaller. A probabilistic distribution of the recoverable resource for the prospect is then produced by using the upside volume (P10) and the inferred P99 to construct a lognormal trend. The method can be tested by companies using lookbacks to fine‐tune the probability of the upside volume to ensure that exploration predictions effectively match historical reality. In the meantime, it is recommended that the PAY method, which is available as a free online tool, is used as a check on the results of stochastic models.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Play analysis is used to delineate areas containing geologically similar discoveries and prospects. The yet‐to‐find (YTF) recoverable resource for a conventional play can be predicted using ...deterministic scenarios utilizing the fact that discoveries within a part play (or common risk segment) can be fitted to a lognormal distribution. Assuming the part play works, a YTF scenario can be made with estimates of (i) the number of drillable prospects, (ii) the average prospect risk, (iii) the resource size of an upside discovery (based on the evaluation of a favoured prospect), and (iv) a downside resource from an implied P99 volume (based on historical data or calculation). A range of YTF is then developed using low, median and high case scenarios. The value of the different scenarios can be estimated provided a minimum economic field size for a generic prospect is available plus a pre‐drill net present value for an average economic discovery. Useful reality checks of YTF estimations include the historical discovery rate, the areal density of traps in analogue settings, the historical average discovery size and the total estimated recoverable resource per unit area. YTF from prospect inventories using Monte Carlo simulations tend to focus on mature areas and are biased to outcomes where all pre‐drill models are correct, unless the prospect sizes are adjusted to account for discoveries which are smaller than predicted by seismic interpretation. YTF estimates will change as information about the play evolves, meaning that it is important that the calculations are kept relatively simple and easy to adjust as new well and seismic data becomes available.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
The provenance of turbidites from the predominantly Arenig-aged Manx Group has been constrained using petrographical and geochemical techniques. Petrographical analysis of sandstones reveals that ...mono- and poly-crystalline quartz grains of cratonic origin are dominant. Major, trace and rare earth element concentrations in both sandstones and mudstones complement the petrographical data indicating that the source of the sediments consisted of quartzose basement and mature sedimentary rocks. There is little evidence of a juvenile volcanic input but a minor palaeovolcanic component of active continental margin affinity is present. There are indications of a more immature character in the oldest units but, on the whole, geochemical data from the Manx Group suggest an overall passive margin setting. These results suggest that Eastern Avalonia was attached to Gondwana during deposition of the Manx Group and that Iapetus oceanic crust did not subduct beneath the region before the end of the Arenig.
Mathematical theory and empirical data show that discovery sizes from mature plays have lognormal distributions. This allows a simple transformation to be used that converts lognormal trends to ...straight lines from which valuable statistical data on exploration potential is derived.
After correcting for the unreliable nature of data from non‐commercial accumulations and then discounting the extreme high ends and low ends (<P99 and >P1), discovery size distributions from a variety of mature plays outside the Middle East show certain common properties that help constrain reserves ranges in individual prospects and new play fairways. These are:
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P99 is 0.3MM brl or less in non‐DHI oil plays and 4BCF or less in gas plays at normal depths;
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P50 reserves fall within the range 7‐35 MM brl or 15–150 BCF (half of all discoveries are smaller than this);
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risked average discovery size is generally 10‐100 MM brl or 20–200 BCF;
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there is somewhere between a 1 in 5 and 1 in 4 chance of finding reserves equal to or larger than the average size of discovery;
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the average minimum economic field size falls between P70 and P30, meaning that around half of all discoveries are too small to be commercial, except in onshore areas close to infrastructure;
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P90 values show the smallest variation over time as a play matures but these rarely become commercial;
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most established conventional plays contain 1–10 billion brl o.e. of recoverable resource.
In contrast, upside reserves, the number of discoveries and the chance of making a discovery are unique to each play. Also, rather than indicating the exploration maturity of a play per se, P10/P90 ratios reflect play specific limits to discovery size, although it is true that the P10/P90 ratio decreases as the number of discoveries increases.
As most large discoveries are made in emergent plays, companies looking for high impact (unusually large) prospects are unlikely to find these in established plays meaning that they need to be prepared to explore at higher risk, often in frontier areas.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
We present late-time (∼240-260 days after peak brightness) optical photometry and nebular (+236 and +264 days) spectroscopy of SN 2018oh, the brightest supernova (SN) Ia observed by the Kepler ...telescope. The Kepler/K2 30 minute cadence observations started days before explosion and continued past peak brightness. For several days after explosion, SN 2018oh had blue "excess" flux in addition to a normal SN rise. The flux excess can be explained by the interaction between the SN and a Roche-lobe filling non-degenerate companion star. Such a scenario should also strip material from the companion star that would emit once the SN ejecta become optically thin, imprinting relatively narrow emission features in its nebular spectrum. We search our nebular spectra for signs of this interaction, including close examination of wavelengths of hydrogen and helium transitions, finding no significant narrow emission. We place upper limits on the luminosity of these features of 2.6, 2.9 and 2.1 × 1037 erg s−1 for H , He i λ5875, and He i λ6678, respectively. Assuming a simple model for the amount of swept-up material, we estimate upper mass limits for hydrogen of 5.4 × 10−4 M and helium of 4.7 × 10−4 M . Such stringent limits are unexpected for the companion-interaction scenario consistent with the early data. No known model can explain the excess flux, its blue color, and the lack of late-time narrow emission features.
In extinction of auditory fear conditioning, rats learn that a tone no longer predicts the occurrence of a footshock. Recent lesion and unit recording studies suggest that the medial prefrontal ...cortex (mPFC) plays an essential role in the inhibition of conditioned fear following extinction. mPFC has robust projections to the amygdala, a structure that is known to mediate the acquisition and expression of conditioned fear. Fear conditioning potentiates the tone responses of neurons in the basolateral amygdala (BLA), which excite neurons in the central nucleus (Ce) of the amygdala. In turn, the Ce projects to the brainstem and hypothalamic areas that mediate fear responses. The present study was undertaken to test the hypothesis that the mPFC inhibits conditioned fear via feedforward inhibition of Ce output neurons. Recording extracellularly from physiologically identified brainstem-projecting Ce neurons, we tested the effect of mPFC prestimulation on Ce responsiveness to synaptic input. In support of our hypothesis, mPFC prestimulation dramatically reduced the responsiveness of Ce output neurons to inputs from the insular cortex and BLA. Thus, our findings support the idea that mPFC gates impulse transmission from the BLA to Ce, perhaps through GABAergic intercalated cells, thereby gating the expression of conditioned fear.
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