High Resolution Correlation of Sequence Stratigraphy to Stipulate Further Hidrocarbon Prospect in A Mature Field : Case Study of Limau Field, South Sumatera Basin

The Limau Trend Structure is located in the South Sumatera Basin of Indonesia. The main reservoir in this field is the Talang Akar Formation which is deposited in a fluvial complex that changes gradually into a shallow marine depositional environment in a transgressive phase of 3rd order sequence. The sediment deposit was developed from the Late Oligocene to Middle Miocene. A high-resolution sequence stratigraphic interpretation of the 3rd to 4th order was interpreted from the subsurface data (core and well log) combined with the outcrop observation that resulted in a comprehensive input for building a geological model. Based on this framework, the transgressive phase series in each parasequence set produces restricted sediment deposits that have the potential for stratigraphic traps. On the other hand, the amalgamated sands of the regression phase will be related to the structural traps. The RMS amplitude volume from seismic multi attributes analysis shows that the facies is changing with the reservoir distribution. The seismic attributes such as VpVs indicate a hydrocarbon presence. The combination of all data reveals that the stratigraphic traps are the main trapping mechanism in the Limau field. The field development works are now focusing in the northern area, on the transgressive phase of the 4th order parasequence set. It composes of a fluvial complex cycle that has a high potential for a virgin geometrically restricted (lense shaped) reservoir rather than well-connected and sand-rich maximum regressive reservoir facies. This transgressive phase reservoir of parasequence set (4th order) at the Northern Belimbing Field was proven by 2 (two) recently drilled wells. Both wells showed very good hydrocarbon indications and produced oil with an initial rate of 174 bopd & 1265 bopd respectively. These results confirmed the oil prospectivity within the transgressive phase of the 4th order parasequence set at the Northern Limau Trend. The initial resources estimation in the Northern Belimbing Field contains 65 MMBO. This is very promising for the development of the Belimbing Field, Limau Trend.

Effect of interactive vs. passive virtual reality on pain threshold and tolerance

Objectives Scientific evidence suggests that virtual reality (VR) could potentially help patients tolerate painful medical procedures and conditions. The aim of this study was to evaluate the efficacy of virtual reality on pain tolerance and threshold. Methods A within-subjects experimental study design was conducted on 53 female students at Qassim University in Saudi Arabia. Each participant completed three rounds of assessment: one baseline (no VR) and two VR immersion (passive and interactive) in random order sequence. During each round, participants submerged their non-dominant hand into an ice bath; pain threshold and tolerance were measured as outcomes and analyzed using repeated measures ANOVA. Results Participants had both higher pain threshold and tolerance during interactive and passive VR rounds in comparison to the non-VR baseline assessment (p<0.05). Participants had greater pain tolerance during the interactive VR condition compared to the passive VR condition (p<0.001). Conclusions VR experiences increase pain threshold and tolerance with minimal side effects, and the larger effects were demonstrated using interactive games. Interactive VR gaming should be considered and tested as a treatment for pain.

Characterizing Promoter and Enhancer Sequences by a Deep Learning Method

Promoters and enhancers are well-known regulatory elements modulating gene expression. As confirmed by high-throughput sequencing technologies, these regulatory elements are bidirectionally transcribed. That is, promoters produce stable mRNA in the sense direction and unstable RNA in the antisense direction, while enhancers transcribe unstable RNA in both directions. Although it is thought that enhancers and promoters share a similar architecture of transcription start sites (TSSs), how the transcriptional machinery distinctly uses these genomic regions as promoters or enhancers remains unclear. To address this issue, we developed a deep learning (DL) method by utilizing a convolutional neural network (CNN) and the saliency algorithm. In comparison with other classifiers, our CNN presented higher predictive performance, suggesting the overarching importance of the high-order sequence features, captured by the CNN. Moreover, our method revealed that there are substantial sequence differences between the enhancers and promoters. Remarkably, the 20–120 bp downstream regions from the center of bidirectional TSSs seemed to contribute to the RNA stability. These regions in promoters tend to have a larger number of guanines and cytosines compared to those in enhancers, and this feature contributed to the classification of the regulatory elements. Our CNN-based method can capture the complex TSS architectures. We found that the genomic regions around TSSs for promoters and enhancers contribute to RNA stability and show GC-biased characteristics as a critical determinant for promoter TSSs.

Generative Capacity of Probabilistic Protein Sequence Models

Potts models and variational autoencoders (VAEs) have recently gained popularity as generative protein sequence models (GPSMs) to explore fitness landscapes and predict the effect of mutations. Despite encouraging results, quantitative characterization and comparison of GPSM-generated probability distributions is still lacking. It is currently unclear whether GPSMs can faithfully reproduce the complex multi-residue mutation patterns observed in natural sequences arising due to epistasis. We develop a set of sequence statistics to comparatively assess the accuracy, or “generative capacity”, of three GPSMs: a pairwise Potts Hamiltonian, a vanilla VAE, and a site-independent model, using natural and synthetic datasets. We show that the generative capacity of the Potts Hamiltonian model is the largest; the higher order mutational statistics generated by the model agree with those observed for natural sequences. In contrast, we show that the vanilla VAE’s generative capacity lies between the pairwise Potts and site-independent models. Importantly, our work measures GPSM generative capacity in terms of higher-order sequence covariation and provides a new framework for evaluating and interpreting GPSM accuracy that emphasizes the role of epistasis.

Cambrian Ordovician sedimentary facies and its evolution in Tadong area

In order to clarify the sedimentary development law under the Cambrian Ordovician regional stratigraphic framework in Tadong area, and lay a theoretical foundation for further oil and gas exploration in the study area. The distribution, characteristics and evolution of main sedimentary facies belts of Cambrian Ordovician are studied by means of drilling core observation, cast thin section identification, logging curve feature analysis, seismic profile and well connection profile. The results show that the Cambrian middle lower Ordovician in Tadong area is equivalent to a second-order sequence and can be further divided into 12 thirdorder sequences. Each third-order sequence is mainly composed of transgressive and highstand tracts. Carbonate platform margin beach facies and Reef (mound) beach complex facies are favorable reservoir development facies belts in this area; Under the regional stratigraphic framework, three types of sedimentary facies can be identified in Cambrian Ordovician, and a total of 10 subfacies are developed; The evolution of sedimentary facies is mainly controlled by the rise and fall of sea level, which is characterized by the migration of platform margin facies and the change of platform facies.

Out-of-phase cyclical sediment supply: A potential causal mechanism for generating stratigraphic asymmetry and explaining sequence stratigraphic spatial variability

ABSTRACT Although acknowledged to be a simplification, the rate of sediment supply is usually assumed to be constant in sequence stratigraphic interpretations of clastic shelf systems. The simplified assumption taken in this work is that sediment supply can be represented by sine curves linked to climate changes driven by Milankovitch cycles. Three orders of sediment supply sine curves (amplitude and frequency scaled to order) are convolved with three orders of Milankovitch-forced eustatic sea-level sine curves and a constant rate of subsidence to generate curves for the ratio of rate of accommodation development to rate of sediment supply (δ A /δ S ). The relative-sea-level curve is then held constant whilst sediment supply is systematically changed from being constant to being cyclical across the three orders of Milankovitch frequencies and being in-phase, and out-of-phase with the eustatic cycles by 90°, 180°, and 270°. For each scenario, stratal architecture is then represented for sixty consecutive parasequences (fifth-order, regressive–transgressive shelf transit cycles) by converting the δ A /δ S curves into pseudo thickness / sandstone fraction plots (TSF plots). Constant sediment supply, in-phase sediment supply, and 180°-out-of-phase sediment supply produce symmetrical stratal geometries with equal periods of progradation, aggradation, and retrogradation. When sediment-supply cycles are 90°-out-of-phase (supply peak occurs later than sea-level peak), stratal geometries are asymmetrical with progradational architectures being dominant. When sediment-supply cycles are 270°-out-of-phase (supply peak occurs earlier than sea-level peak), stratal geometries are also asymmetrical but retrogradational architectures are dominant. These patterns are reproduced at all three orders of stratigraphic hierarchy (parasequence, sequence, and composite sequence). Comparison of these synthetic stratal geometries to real-world stratal geometries from Triassic to Neogene rocks across both the fifth-order (parasequence) and fourth-order (sequence) of stratal hierarchies suggests a consistently occurring asymmetrical, progradation-dominant motif. This indicates that 90°-out-of-phase sediment supply (supply peak occurs later than sea-level peak) may be a common occurrence through geological time. The work also corroborates the findings of earlier workers and suggests that sequence stratigraphic surfaces can change nature along depositional strike due to out-of-phase sediment supply and can thus also be diachronous. This work conceptually illustrates that Milankovitch climate-change-induced sinusoidal-sediment-supply cycles, out-of-phase with sinusoidal eustatic-sea-level cycles, may produce commonly observed asymmetrical stratal architectures and should be considered when invoking causal mechanisms for stratal architectures on clastic shelves.

Evaluation of audio-voice guided application for neonatal resuscitation: a prospective, randomized, pilot study

ObjectivesTo examine whether audio-voice guidance application improves adherence to resuscitation sequence and recommended time frames during neonatal resuscitation.MethodsA prospective, randomized, pilot study examining the use of an audio-voice application for guiding resuscitation on newborn mannequins, based on the Neonatal Resuscitation Program (NRP) algorithm. Two different scenarios, with and without voice guidance, were presented to 20 medical personnel (2 midwives, 8 nurses, and 10 physicians) in random order, and their performance videotaped.ResultsAudio-voice guided resuscitation compared with non-guided resuscitation, resulted in significantly better compliance with NRP order sequence (p<0.01), correct use of oxygen supplementation (p<0.01) and performance of MR SOPA (Mask, reposition, suction, open mouth, pressure, airway) (p<0.01), and shortened the time to “positive pressure ventilation” (p<0.01).ConclusionsIn this pilot study, audio-voice guidance application for newborn resuscitation simulation on mannequins, based on the NRP algorithm, improved adherence and performance of NRP guidelines.

DIGITAL WALLET USING ARM MICROCONTROLLER

In this work, a novel technique based on second order sequence filter and proportional resonant controller is proposed for control of universal active power filter integrated with PV array system (UAPF-PV). Using a second order sequence filter and sampling it at zero crossing of instant of the load voltage, the active component of distorted load current is estimated which is further used to generate reference signal for shunt active filter. The proposed method has good accuracy in extracting fundamental active component of distorted and unbalanced load currents with reduced mathematical computations. Along with power quality improvement, the system also generates clean energy through the PV array system integrated to its DC-bus. The UAPF-PV system integrates benefits of power quality improvement and distributed generation. The system performance is experimentally evaluated on an experimental prototype in the laboratory under a variety of disturbance conditions such as PCC voltage fall/rise, load unbalancing and variation in solar irradiation