bluuebunny/crossref_metadata_2025 huggingface dataset:
Array Production Survey Accurately Pinpoints Water Shut-Off Location and Strengthen the Understanding on Remaining Potential of a Giant Carbonate Gas Field, Offshore East Malaysia
Authors: Ahmad Noor Afiqah , Chieng Zhin Houng , Jelie Anie , Abdul Rahman Hazrina , M Amin M Farid , Foo Nicholas Kwang Hui , Zakeria Ahmad Fakrudin , Sidek Sulaiman , Yahya Fadzil , Ramli Syamim , Suhari Azahari , Abd Manan Mohd Zahir
Published: October 2021

Over the years, Multiple Array Production Suite (MAPS) has been run several times in Offshore Peninsular Malaysia but never in Offshore East of Malaysia. Field A is located 260km North-North West of Bintulu, Offshore Sarawak and was discovered in 1992 with first gas produced in 2004. One of the many challenges currently faced in managing the field is the prediction and handling of water breakthrough at the existing producers. Based on historical data, water breakthrough from carbonate Zone T begin around 2010 which then followed by series of Water Shut-Off (WSO) campaign. To strengthen the understanding, evaluate the remaining potential and to optimize near term well and reservoir management of the field, an integrated remedial approach is essential. Well-AA was identified for mechanical WSO in an effort to remediate high water production and improve well productivity. The target well was chosen as the well unable to sustain production after a rapid tubing pressure drop due to the highest water production in the field. Moreover, its production had to be capped due to the water production constraints at the receiving hub. Production Logging (PL) was planned across the carbonate sections to accurately identify the appropriate zones for WSO operations.

The long horizontal section and high water production typically create a stratified flow regime that forces a smaller volume of hydrocarbon to flow on the high side of the well, hence the conventional PL technology would have been unable to deliver accurate and insightful results. As such, the MAPS technology was run for an initial assessment to identify the water producing zones. MAPS was deployed using wireline tractor and was combined with the Noise Tool (NTO) to provide a comprehensive 3D image of the multi-phase flow profile across the entire wellbore and to investigate the integrity of annular swell packers located in between the carbonate sections.

This paper illustrates the best practices involved in the successful downhole Production Logging with a Multiple Array Production Suite and Digital Noise Tool (PL-MAPS-NTO) toolstring, which served as the key input in determining the WSO treatment depth and strategy in Well-AA, that may lead to a potential gain of 10.8MMscf/d.
Optimized Clay Control Fracturing Fluid Used in a Highly Water-Sensitive Tight Oil Reservoir Hydraulic Fracturing Application in Xinjiang Oil Field: Case Study
Authors: Mao Xinjun , Chen Chaofeng , Gan Renzhong , Zhou Shubo , Wang Zichao , Zhao Zhoumin
Published: October 2021

The candidate wells are tight oil wells and most of the wells in the area have a low recovery rate of fracturing fluid after fracturing treatment. The lithology is glutenite with weak cementation and a high sensitivity tendency. This paper presents the process of sensitivity evaluation and fracturing fluid evaluation. Also, this paper introduces a customized and optimized clay control fracturing fluid wells in a highly sensitive reservoir.

Per local national standard, traditional methods of swelling test (ST) and x-ray diffraction (XRD) were employed for qualitative formation cutting analysis. An innovative trial was then developed to evaluate cores quantitatively by water sensitivity. A clay stabilizer was then chosen to be used for the highly sensitive cores and regain permeability testing of the broken fracturing fluid was performed. Based on the analysis and evaluation, a customized treatment design was initiated for the hydraulic fracturing treatment.

The qualitative evaluation showed the rock is highly water sensitive and the cores easily collapse because of weak cementation. No flow could be established during traditional core flow tests with brine. The newly developed method used kerosene as the working fluid to prevent the cores from contact with water or brine. The core flow tests resulted in a velocity sensitivity damage rate of 92%, which is considered as highly velocity sensitive. Accordingly, a special clay stabilizer was chosen to be used in the fracturing fluid and the permeability damage of the broken fracturing fluid is only 26.9%(Table 16).

Field results have shown that the fracturing fluid recovery rate in treated wells is higher than the area average level and treated wells have significant oil production increase. The innovative clay control fracturing fluid and its field application reduces the influence of water and velocity sensitivity. The customized treatment with special clay stabilizer helps increase the recovery rate of fracturing fluid in reservoirs with severe clay stability and weak cementation issues.
Towards 1 Million Barrels Oil Per Day in 2030: Visual Analytics for Artificial Lift Performance Optimization in Indonesia
Authors: Falach Achmad Rocky , Warasta Ageng , Ihsan Alfandra , Dewi Amalia Kusuma , Safrizal Heri , Perfibita Randy , Kauripan Satria Panji
Published: October 2021

One of the strategies to achieve Indonesia's main goal to produce one million barrels oil per day in 2030 is to maintain existing production volume. The key of maintain the existing production is to optimize artificial lift performance used in oil wells, because 96% of oil wells in Indonesia had installed artificial lifts and their performance will significantly affect the production decline rate. This approach aims to create a simple data visualization from macro perspective, to evaluate the artificial lift performance of all oil wells in Indonesia and to find a solution to optimize their performance.

This method is started by collecting the main parameters that describes the artificial lift performance such as artificial lift type, historical run life, historical operating cost, production rate, reservoir depth, type of fluid as well as additional issues from each field in Indonesia. After the data is gathered, the next step is to cluster the usage of various artificial lifts in Indonesia, which have similarities such as area, crude type, depth, rate, and operational problems, in terms of comparison between the optimum case and non-optimum one. Finally, from the non-optimum one, it will be evaluated on more detailed programs for further optimization. This evaluation process is carried out by visualizing all the data gathered using some informative dashboards. The digitalization is expected to help the improvement of evaluation time and to support decision processes.

By implementing this method, several success cases were demonstrated in 2020, like optimizing Sucker Rod Pump (SRP) component in one of the fields in Sumatra, with the gain around 120 BOPD, Gas lift and SRP to Electric Submersible Pump (ESP) conversion in one of the fields in Kalimantan with 160 BOPD production outcome, switching normal ESP rate to lower rate ESP which resulted from double run life compared with the previous one, and also conversion from SRP to HPU that can extend its run life, while creating cost efficiency. From those results, it shows the benefit of the dashboards created for artificial lift optimization, especially from Government point of view. Furthermore, there are around 50 wells that will be evaluated in detail for optimization program.

The visual analytics of the dashboards, for example, will help the evaluation process all at once providing positive impacts on artificial lift optimalization program. In the future, we hope that these dashboards could be developed further, by combining the implementation of machine learning, like fuzzy logic methods or neural network, to enhance the operator performance and to improve production efficiency toward the achievement of one million barrels oil per day in 2030.
Building the Digital Workplace on SharePoint to Support Drilling and Completion Activities
Authors: Nguyen Cuong Kien , Le Tri Tran Minh , Le Son Ngoc
Published: October 2021

Over the last five years, the oil market has experienced its most significant downturn since 1990s which resulted in the greatest immediate impact on the exploration and development drilling segment of the industry. With the objective to counter the influence of this potentially long period of downturn in global oil price, oil & gas operators have opted for different approaches to secure their future recovery and growth. The digital transformation across their drilling and completion activities could be a solution which helps to improve the drilling efficiency, shorten the well time, and cut down the well cost to the tolerable investment. In addition to that, the need of switching to a digital environment has recently became an urgent requirement, especially when everywhere in the world applies the social distancing and work from home concept during Covid-19 pandemic. Therefore, establishing a digital workplace has set an approach in a way drilling and completion teams handling internal and external communications, collaborations and content management to support drilling and completion activities.

In order to understand more in depth, this paper, as a part of the digital transformation project carried out by Phu Quoc Petroleum Operating Company (PQPOC), the Operator of Block B Gas Development Project (Blocks B&48/95 and 52/97) located offshore of the South West of Vietnam, will make clear how to build a digital workplace on SharePoint, what features should be included in this platform, and how it can support drilling and completion activities.
Innovative Method for Efficient Real Time Online Well Monitoring to Enhance Crew Respond Time in Marginal Field
Authors: Massewa Dias Anugrah , Rifaat Muhammad , Akbar Ferdyan Ihza , Fadri Rahmanda , Akbar Denny Mulia , Rachmadani Aris , Uswitra Ichbal , Nugraha Fahmi , Purnama Fertian Eka , Zaelani Bomantara , Widijanto Ridwan
Published: October 2021

Previously, well monitoring in Siak block relied on production crew scheduled tour that needed six hours to complete one cycle of all wells in Lindai field. This paper describes the utilization of digital technology to observe well parameters while sending notification if there is any anomaly regarding those parameters through smart phone application or website.

Smart microcontroller was installed in wellhead panel and three sensors are mounted in desired point around wellhead to perform online Intelligent Well Monitoring (IWM) for well’s parameters. If abnormality occurs, real time notification would be sent to user’s smart phone application or website by using global mobile communication system (GSM) signal. The parameters monitored were pressure, temperature, and load because they are essential to be analyzed as initial diagnosis of well problem. Based on the readings, production team could quickly perform troubleshooting to prevent loss production opportunity (LPO). The programming of this smart microcontroller used C language as data compiler.

This method was tested in one of the wells in Lindai field, which has the highest oil production. After three months of surveillance, in terms of data quality, the values shown by this tool had only five percent differences compared to manual survey using calibrated measurement tools. Additionally, the parameters could be monitored online, real time, and gave the notification directly to users should there be any issues. Moreover, this tool could reduce the response time of the field crew significantly from six hours following the conventional field tour to only in five minutes by relying on real time notification. In addition, the operational cost of this tool was 82% cheaper compared to other well-known online monitoring tool available in the market so it is considered economical. In the long term, this tool will be implemented on all wells in Siak block for integrated real time monitoring. Furthermore, the impact of field scale implementation will be much greater such as increasing data accuracy by eliminating human error from manual well checking and improving safety of the crew by reducing the possibility of fatigue.

The utilization of smart microcontroller for online well monitoring is beneficial for marginal field with high number of wells and wide field coverage. Earlier, real time well monitoring is usually considered expensive investment that rarely become priority. However, the implementation of IoT (Internet of Things) by using this tool can be the game changer in marginal field and maximize the well’s production by reducing LPO.
Well Testing Based Method to Identify the Complex Fracture Geometry and Changing Drainage Radius Using an Efficient Boundary Element Model
Authors: Deng Cai , Shi Hua , Zhang Jiali , Liao Xinwei , Chen Zhiming , Li Dexuan
Published: October 2021

Fracture geometries and drainage radius are important parameters for developing a reasonable development plan of a single fractured well. In some unconventional gas reservoir, some scholars observed the phenomenon of single well controlled reserves increasing through the material balance curve, and put forward the idea of district supply. In addition, owing to fracture hits, the fracture geometries of fractured wells are sometimes more complex. Thus, those complex factors bring challenges for parameter estimations.

In order to study the variation of the drainage radius and complex fracture geometries in the single model, a well testing based model for a finite-conductivity fractured vertical well in radial composite reservoirs with dynamic supply and fracture networks is established. Based on "successive steady state method", the point source function, pressure superposition principle and boundary element method are used to solve the reservoir model, and the methods of discrete fracture and pressure superposition are used to solve the fracture model. By introducing the rate normalized pseudo-pressure and material balance time, the variable fluid flux is equivalent to the constant fluid flux. Combined with the inversion idea of well test, the drainage radius value and fracture geometries are solved by fitting the log-log curves of pressure response, and case studies are performed. The results show that the drainage radius increases with the increase of production time and finally tends to a certain value, and it has a good exponential relationship with time. Also, the fracture geometries of the typical well are multiple-radial fracture networks. Through the study of dynamic drainage radius, the controlled reserves of single well in unconventional gas reservoir can be better determined, and it can also provide theoretical basis for fracture evaluation, productivity prediction and enhanced recovery study of the same type of unconventional gas reservoir.
Study of the Cause of Lost Circulation while Drilling Fractured Carbonates
Authors: Ruzhnikov Alexey
Published: October 2021

Fractured carbonate formations are prone to lost circulation, which affects the well construction process and has longtime effect on well integrity. Depending on the nature of losses (either induced or related to local dissolutions) the success rate is different when the induced losses can be cured with a high chance, and the one related to dissolutions may take a long time, and despite multiple attempts, the success rate is normally low.

To have a better understanding of the complete losses across the fractured carbonates, a series of studies were initiated. First, to understand the strength of the loss zone, the fracture closing pressure was evaluated studying the fluid level in the annulus and back-calculating the effect of drilling fluid density. Second, the formation properties across the loss circulation zones were studied using microresistivity images, dip data, and imaging of fluid-saturated porous media.

The results of the studies brought a lot of new information and explained some previous mysteries. The formation strength across the lost circulation zone was measured, and it was confirmed that it remains constant despite other changes of the well construction parameters. Additionally, it was confirmed that the carbonates are naturally highly fractured, having over 900 fractures along the wellbore. The loss circulation zone was characterized, and it was confirmed that the losses are not related to the fractures but rather to the karst, dissolution, and megafractures. The size and dip of the fractures were identified, and it was proven the possibility to treat them with conventional materials. However, the size of identified megafractures and karst zones exceeding the fractures by 10 times in true vertical depth, and in horizontal wells the difference is even higher due to measured depth. This new information helps to explain the previous unsuccessful attempts with the conventional lost circulation materials.

The manuscript provides new information on the fractured carbonate formation characterization not available previously in the literature. It allows to align the subsurface and drilling visions regarding the nature of the losses and further develop the curing mechanisms.
Pitching Early for CCUS Research and Development in Oil & Gas Industry: A Well Thought Endeavor
Authors: Tewari Raj Deo , Sedaralit Mohd Faizal , Lal Bhajan
Published: October 2021

The oil and gas industry, a highly technical industry, involves a collaboration of various disciplines of science and technology from exploration to production and utilization of the products. Continuous research and technology developments have improved the success of the industry. Oil and Gas will continue to play important role in the total energy mix due to their affordability and easiness of use. The infrastructure and facilities viz, drilling rigs, pipeline, casing and tubular, platforms and chemical produced from other industries also contribute significant greenhouse gas (GHG) emission. Increased use of oil & gas is causing the emission of GHG in the atmosphere causing temperature rise of the earth which is a major cause for climate change. The increasing demand for natural gas is necessitating the development of giant contaminated gas fields which will further increase GHG production significantly. Natural gas would be the transition fuel from conventional to renewable energy sources.

Climate science is understood, and experts are of the view that current and enhanced future emissions of GHG will have a catastrophic effect on the environment. It has to be controlled and produced contaminated gases need to be stored safely and utilized for humanity. Improvement in energy efficiency and environmental sustainability by reduction of greenhouse gas emissions from the industrial operations as well as from energy use by consumers is picking up. Carbon capture, separation, transportation, storage, and utilization has started at a small scale. There is an urgent need to improve yesterday’s performance and meet tomorrow’s challenge in CCUS in the petroleum industry.

Fundamental research for capturing, utilization and storage of GHG has to be enhanced for improvising the processes. It is a fact that technology stimulates science, science stimulates technology, and both stimulate the efficiency of the process. Because of this, success mantra and objective for better performance, oil and gas companies are investing and pursuing research and development for controlling and managing the carbon capture utilization and storage (CCUS).

This paper discusses the result of active Research and Development of CCUS which is being pursued for the last decades for fundamental issues of separation of carbon dioxide, transportation, subsurface storage physics & chemistry and utilization of the CO2 into usable products. Scientific results and findings of basic and applied research for better efficiency and cost-effectiveness of the products like precipitated calcium carbonate (PCC), alcohols and methane generation by Methanogenesis. Supercritical behavior of CO2 in subsurface, geomechanical and geochemical changes during and after storage, enhancing trapping mechanism, the effect of H2S on CO2 storage and understanding the science of contaminant separation and areas of improvement in methodologies will be presented and highlighted.
Pioneering Secondary Recovery Strategies in a Complex Geological Environment and Challenging Reservoirs Located in Offshore Sarawak
Authors: Suggust Alister Albert , Khalid Aizuddin , Usop Mohammad Zulfiqar , M Khalil M Idraki
Published: October 2021

The Balingian province is located offshore Sarawak, comprising of at least 7 oil fields with its regional geology consisting of a combination of deltaic & shoreface system. Though consisting of clastic reservoirs, the fields are highly sophisticated in terms of reservoir compartmentalization, hence uncertainties in fluid contacts, differing depletion strategies and varying production performance per well. As the regional production has gone into brownfield stage, the challenge is to determine the most suitable secondary recovery method to prolong field life. The subsurface & feasibility studies conducted produced mixed results between application of water & gas injection, giving recovery factors between 30 to 40%, and implementation so much depending on source of water & gas and cost benefit analyses. The application of IOR across Balingian province are executed in pilot mode across all fields. While the pilots are still continuing, this paper is to share the methodology, recovery factors and process of the regional study and some results from the ongoing surveillance post-execution, and the wayforward.
Resolving Multiple Formation Damage Mechanism in Carbonate Reservoir Through Systematic Approach Using Combination of Aromatic Solvent and Less Aggressive Acid
Authors: Kamal Hamzah , Noke Fajar Prakoso , Farid Ghozali , Agus Aryanto , Tri Atmojo Priyantoro , Kautsar Amru , Pradhipta Seno Respati
Published: October 2021

There is no well operation that is truly non-damaging. Any invasive operation, even production phase itself, may be damaging to well productivity. An interesting case was found in L-Field which is located in South Sumatra, Indonesia. All four wells are predicted to cease to flow after five-year production and artificial lift have to be installed to prevent steep decline in oil production. Unfortunately, all of wells’ productivity index (PI) decreased post well intervention and therefore, couldn’t achieve target. The PI was continuously decreasing during production phase and aggravated the decline in oil production.

Remediation action by systematic approach was applied to solve the problem. Early diagnostic revealed some potential causes through evaluation of both production and well treatment data. Laboratory test such as mineralogy analysis, crude composition and water analysis, solubility and compatibility test have been conducted and clarified the root cause that formation damage occurred in multiple mechanism related to incompatibility of the workover fluid and organic deposition. Then, possible well treatments were listed with pros and cons by considering post water production related to the carbonate reservoir properties.

Subsequently, chemical matrix injection was ranked based on less possibility of water breakthrough risk. Diesel fuel and de-emulsifier injection was decided as the first treatment in order to remove formation damage caused by organic deposition. The rate was increased temporary with Water Cut (WC) remained at the same level. The subseqeuent effort was to inject low reaction chelating acid and the result showed temporary improvement and the production did achieve significant gain. Finally, the third attempt indicated promising results with the injection of aromatic solvent followed by chelating acid. The well productivity was increased to more than 20 times of the pre treatment levels. The method can be replicated to other affected wells with similar damage mechanism.

High vertical permeability over horizontal permeability becomes a real threat in carbonate strong water driver reservoir in L-field. Thus, matrix acidizing treatment has to be carefully applied to prevent unwanted water production. Non-aggressive and slow reaction acid were chosen to prevent face dissolution reaction that leads to water breakthrough.
Periodic Solution of a Stochastic Microorganism Flocculation Model with Distributed Delay
Authors: Mu Xiaojie , Jiang Daqing
Published: October 2021

In this paper, a nonautonomous delay differential equation of microorganism flocculation is established by considering the influence of external conditions such as seasonal alternation and ocean current movement on the ecological function of microorganism population. At the same time, the dynamic change characteristics of microorganism population in oil spill environment were simulated, and on this basis, the effects of diurnal change and climate change on the parameters of microorganism system were analyzed. From a mathematical point of view, the stochastic microorganism flocculation model exists a T-positive periodic solution. The existence and uniqueness of globally positive equilibrium of the exploited model is studied. Finally, some numerical examples illustrate the results.
Numerical Simulation of Natural Convection and Calculation of Heat Transfer Coefficient in Wellbore Annulus during Deep-Water Gas Well Testing
Authors: Liu Hui , Wang Zhiyuan , Sun Baojiang , Lou Wenqiang , Zhang Jianbo , Liu Zheng
Published: October 2021

Most of the current prediction model of wellbore temperature for deep-water gas well does not consider the influence of natural convection in annulus on the heat dissipation of the system, resulting in a lower prediction accuracy of temperature. In this study, three-dimensional simulation on the heat transfer by natural convective of testing fluid in annulus was performed. The mechanism of heat transfer are studied for different values of Rayleigh number (Ra) and Bingham number (Bn). The results show that the occurrence of natural convection in the annulus can significantly increase the heat loss of the fluid in the tubing. With the increases in Ra or decreases in Bn, the convective transport in annulus gradually strengthens, and the heat transfer coefficient gradually increases. However, when the Bingham number increases to about 100, the heat transfer mode in annulus becomes a single heat conduction. Based on the simulation results, a new correlation of heat transfer coefficients in annulus was proposed. The introduction of this correlation can significantly improve the prediction accuracy of wellbore temperature during deep water gas well testing, and lay a foundation for the prevention and control of hydrate and wax formation in wellbore.
Integrating Underwater Data into GIS for Offshore Decommissioning in Bass Strait, Australia
Authors: Lambert Jamie , Bok Melanie , Aziz Azivy
Published: October 2021

Through asset lifecycle, data is collected for a variety of purposes across multiple disciplines, and exists in various formats and repositories. Decommissioning projects utilize and repurpose a multitude of these datasets; from use in analysis and planning, to facilitating systematic environmental assessments, and meaningful discussion with stakeholders. The key challenge is how do we consolidate historical data, incorporate new data, and make it evergreen to support planning and informed decision making; and how do we coordinate large volumes of previously disparate data in a meaningful way for all users with a simple access model?

A team of geographic information system (GIS) practitioners and subject matter contacts in technical and health, safety and environment (HSE) disciplines was convened to collect, sort, and compile known historical offshore data, including, but not limited to; pipeline and structural inspections and environmental studies, all captured via Remote Operated Vehicle (ROV), Side Scan Sonar (SSS), and sampling programs. Data was reformatted to standardize headers and attributes allowing for merging of existing like-data and to support new data integration. To this end, we also worked collaboratively with vendors to optimize data collection and improve alignment with our internal data structures.

The Esri GIS technology was utilized for data integration, specifically the web and mobile environments. Through these environments, non-GIS users could easily access data and focused applications, supporting ease of data visualization and allowing for a single view of data spanning decades and covering multiple themes. This enabled an enhanced understanding of the offshore environment, allowing us to identify gaps and focus areas for future data capture, helping to facilitate cross-discipline discussions, and identification of operational synergies; improving access, efficiency, and reducing decommissioning costs.

Data integration resulting from this initiative and delivery through a spatially aware GIS environment is providing unprecedented access to a vast scope of cross-disciplinary data previously not possible with more traditional engineering methods and data formats. Data accessibility aids communication, and when combined with early engagement across multi-disciplinary teams, the path to decision making is reduced, synergies gained, and costs are reduced through improved efficiency and optimization.
A descriptive analysis of the impact of COVID-19 on Emergency Department attendance and visit characteristics in Singapore
Authors: Lim Mei Qiu , Siddiqui Fahad Javaid , Saffari Seyed Ehsan , Ho Andrew Fu Wah , Liew Johannes Nathaniel Min Hui , Tan Boon Kiat Kenneth , Sim Nicole Simin , Shen Yuzhen , Ong Marcus Eng Hock
Published: October 2021

Background: The coronavirus disease 2019 (COVID-19) has impacted the utilisation of Emergency Department (ED) services worldwide. This study aims to describe the changes in attendance of a single ED and corresponding patient visit characteristics before and during the COVID-19 period. Methods: In a single-centre retrospective cohort study, we used descriptive statistics to compare ED attendance, patient demographics and visit characteristics during the COVID-19 period (1 January – 28 June 2020) and its corresponding historical period in 2019 (2 January – 30 June 2019). Results: Mean ED attendance decreased from 342 visits/day in the pre-COVID-19 period, to 297 visits/day in the COVID-19 period. This was accompanied by a decline in presentations in nearly every ICD-10-CM diagnosis category except for respiratory-related diseases. Notably, we observed reductions in visits by critically ill patients and severe disease presentations during the COVID-19 period. We also noted a shift in ED patient case-mix from ‘Non-fever’ cases to ‘Fever’ cases, likely giving rise to two distinct trough-to-peak visit patterns during the pre-Circuit Breaker and Circuit Breaker period. Conclusions: This descriptive study revealed distinct ED visit trends across different time periods. The COVID-19 pandemic caused a reduction in ED attendances amongst patients with low-acuity conditions and those with highest priority for emergency care. This raises concern about treatment-seeking delays and possible impact on health outcomes. The downward trend in low-acuity presentations also presents learning opportunities for ED crowd management planning in a post-COVID-19 era.
FIOLA: An accelerated pipeline for Fluorescence Imaging OnLine Analysis
Authors: Giovannucci Andrea , Cai Changjia , Dong Cynthia , Rozsa Marton , Pnevmatikakis Eftychios
Published: October 2021

Optical microscopy methods such as calcium and voltage imaging already enable fast activity readout (30-1000Hz) of large neuronal populations using light. However, the lack of corresponding advances in online algorithms has slowed progress in retrieving information about neural activity during or shortly after an experiment. This technological gap not only prevents the execution of novel real-time closed-loop experiments, but also hampers fast experiment-analysis-theory turnover for high-throughput imaging modalities. The fundamental challenge is to reliably extract neural activity from fluorescence imaging frames at speeds compatible with new indicator dynamics and imaging modalities. To meet these challenges and requirements, we propose a framework for Fluorescence Imaging OnLine Analysis (FIOLA). FIOLA exploits computational graphs and accelerated hardware to preprocess fluorescence imaging movies and extract fluorescence traces at speeds in excess of 300Hz on calcium imaging datasets and at speeds over 400Hz on voltage imaging datasets. Besides, we present the first real-time spike extraction algorithm for voltage imaging data. We evaluate FIOLA on both simulated data and real data, demonstrating reliable and scalable performance. Our methods provide the computational substrate required to interface precisely large neuronal populations and machines in real-time, enabling new applications in neuroprosthetics, brain-machine interfaces, and experimental neuroscience. Moreover, this new set of tools is poised to dramatically shorten the experiment-data-theory cycle by providing immediate feedback on the activity of large neuronal populations at experimental time.
Diverse Responses of Phenology in Multi-Grassland to Environmental Factors on Qinghai-Tibetan Plateau in China
Authors: Qin Gexia , Adu Benjamin , Li Chunbin , Wu Jing
Published: October 2021

Revealing grassland growing season spatial patterns and their climatic controls is crucial for the understanding of the productivity change mechanism in regional terrestrial ecosystem. However, the multi-grassland phenological factors are different, which has not been well studied. In this paper, the spatio-temporal patterns of the grassland start of the growing season (SOS) and the end of growing season (EOS) were investigated using MODIS Normalized Difference Vegetation Index (NDVI) on the Qinghai-Tibetan Plateau (QTP) during 2000 to 2019. At the same time, we analyzed the factors (including extreme and mean climate, drought, solar radiation, etc.) regulating grassland phenology under ongoing climate change. The results showed that the SOS appeared first in mountain meadow, shrub-tussock, temperature steppe and desert, then in alpine steppe and alpine meadow, showed a significant advancing tendency in all types. The EOS appeared first in temperature steppe, alpine steppe and alpine meadow, then in mountain meadow, shrub-tussock and desert. Further analysis indicated that the decrease of yearly minimum value of daily minimum temperature (TNN), yearly maximum value of daily minimum temperature (TNX), Temperature vegetation dryness index (TVDI) and the increase of yearly maximum consecutive five-day precipitation (RX5day) advance the grassland spring phenology, whereas the increase of solar radiation (SR) delay the grassland spring phenology. Meanwhile, SOS and its change rate showed the trend of significant delay and decline with the increase of altitude, respectively. We also found that the decrease of TVDI, TNN and the increase of yearly mean value of temperature (MAT_MEAN), yearly mean value of daily maximum temperature (MAT_MAX) and yearly mean value of daily minimum temperature (MAT_MIN) advanced the autumn phenology. The EOS and its change rate advance and increase with increasing altitude, respectively.
Impact of Family Function on Mental Health Problems of College Students in China During COVID-19 Pandemic and Moderating Role of Coping Style: A Longitudinal Study
Authors: Liu Lili , Chen Jianbin , Liang Shunwei , Yang Wenwen , Peng Xiaodan , Cai Chengcheng , Huang Andi , Wang Xiayong , Zhao Jingbo
Published: October 2021

Background. During the COVID-19 pandemic, college students were required to stay at home and maintain social distancing the entire spring semester of 2020. There is little research on how family function influenced mental health problems and how coping styles moderated the relationship between family function and mental health problems among college students during their stay-at-home period.Methods. We carried out four evaluations between February and October 2020 through an online survey. A total of 13,462 college students (age = 16--29 years) participated. Family function, coping styles, depression symptoms, and anxiety symptoms were studied. To evaluate the associations between variables, a generalized estimating equation was used. Results. Findings indicate that the incidence rates of depression rose during stay-at-home period from 33.87% to 40.08% after schools reopened. The incidence rates of anxiety rose from 17.45% to 26.53% through the entire period. The two-way interaction of time × family function for depression and anxiety were significant (χ2 = 52.97, p < 0.001 and χ2 = 51.25, p < 0.001, respectively). The three-way interaction of time × family function × coping style were also significant for depression and anxiety (χ2 = 862.09, p < 0.001 and χ2 = 583.29, p < 0.001, respectively) Conclusions. These findings shed light on how family function intersected with coping styles to influence the mental health problems of college students during and after the stay-at-home period of COVID-19.
Copper restoration by liver Ceruloplasmin ablation ameliorates NAFLD via SCO1-AMPK-LKB1 complex
Authors: Liu Junli , Xie Liping , Yuan Yanmei , Xu Simiao , Lu Sijia , Wang Yanping , Wang Yibing , Zhang Xianjing , Chen Suzhen , Lu Junxi , Sun Honglin , Hu Ruixiang , Piao Hai-long , Wang Cunchuan , Wang Jing , Li Na , White Morris , Jia Weiping , Miao Ji
Published: October 2021

Copper is an essential nutrient and a co-factor of numerous enzymes governing a wide range of intracellular processes. Copper deficiency has emerged to be associated with various lipid metabolism diseases, including non-alcoholic fatty liver disease (NAFLD). However, the molecular mechanisms of how copper regulates lipid metabolism and is sensed remain elusive. Here, we reveal that copper elevation caused by hepatic ceruloplasmin (CP) ablation enhances lipid catabolism by promoting the assembly of copper-load SCO1/AMPK complex. We report that overnutrition-mediated CP elevation results in hepatic copper loss, and that liver-specific CP ablation counteracts this reduction in copper levels and ameliorates NAFLD in mice. Mechanistically, SCO1 constitutively interacts with LKB1 even in the absence of copper, and copper-loaded SCO1 directly tethers LKB1 to AMPK, thereby activating AMPK and consequently promoting mitochondrial biogenesis and fatty acid oxidation in hepatocytes. Therefore, this study reveals an unexpected role for AMPK to sense copper alteration via SCO1 and uncovers a previously unidentified mechanism by which copper, as a signaling molecule, improves hepatic lipid catabolism, and indicates that targeting copper-AMPK signaling pathway ameliorates NAFLD development by modulating AMPK activity.
Gut metagenome associations with extensive digital health data in a volunteer-based Estonian microbiome cohort
Authors: Aasmets Oliver , Krigul Kertu , Lüll Kreete , Metspalu Andres , Org Elin
Published: October 2021

Microbiome research is starting to move beyond the exploratory phase towards interventional trials and therefore well-characterized cohorts will be instrumental for generating hypothesis and providing new knowledge. As part of the Estonian Biobank (EstBB), we established the Estonian Microbiome Cohort (EstMB) which includes stool, oral and plasma samples from 2,509 participants and is supplemented with multi-omic measurements, questionnaires, and regular linkages to national electronic health records (EHRs). In this study, we analyzed stool data from deep metagenomic sequencing together with rich phenotyping, including 71 diseases, 136 medications, 21 dietary questions, 5 procedures, and 19 other factors. The data revealed numerous relationships (n = 3262) with different microbiome features. Additionally, we present that long-term antibiotic usage, independent from recent administration, has a significant impact on the microbiome composition, partly explaining the common associations between diseases. Overall, this study extends the understanding of microbiome–host interactions and facilitates the development of microbiome-related studies.
Mosquito control, killing off the females
Authors: Tran Phi
Published: October 2021

In addition to causing discomfort, female mosquitoes introduce disease-carrying viruses and bacteria into the bloodstream of their victims. There are numerous publications describing the uses of sugary mosquito baits with promising results. However, without temperature control measures, these methods are mainly useful for only nectar feeding insects, including male mosquitoes, because the warmth of the blood is a condition for the females to locate their meals. The efforts required to keep the baits fresh against the natural spoiling process make them less attractive or impractical to implement. These experiments address these issues by using warm baits of water, sugar, boric acid and antibiotics. On the surface, the area became a sought-out island where mosquito activities flourished; nevertheless, the mosquitoes were exclusively males (almost). Control vs. experiment protocol established no other logical explanation for this phenomenon other than that the females were attracted and killed by the bait. As expected, there was no mosquito egg laying in these areas.
Adsorption Behaviors and Mechanisms of Cu2+, Zn2+ and Pb2+ by Magnetically Modified Lignite
Authors: Di Junzhen , Ruan Zhen , Zhang Siyi
Published: October 2021

In order to solve the problems of high content of Cu2+, Zn2+ and Pb2+ in acid mine wastewater (AMD), and limited adsorption capacity of lignite, the lignite was used as raw material to prepare magnetically modified lignite (MML), and adsorption performance of lignite and MML on Cu2+, Zn2+ and Pb2+ was investigated by static beaker experiment and dynamic continuous column experiment. At the same time, the adsorption mechanism was revealed by means of scanning electron microscopy (SEM), X-ray diffractometer (XRD) and Fourier transform infrared spectrometer (FTIR). The results showed that the adsorption processes of lignite and MML on heavy metal ions were more consistent with the Langmuir model, obeying the quasi first-order model and quasi second-order model, respectively. In addition, the intraparticle diffusion model indicated that the adsorption processes were jointly controlled by multiple adsorption stages. The dynamic continuous column experiments showed that the average removal rates of Cu2+, Zn2+ and Pb2+ were 78.00%, 76.97% and 78.65% for lignite and 82.83%, 81.57% and 83.50% for MML, respectively. Compared with lignite, the adsorption effect of MML was better. From SEM, XRD and FTIR tests, it can be seen that the magnetic modification process successfully loads Fe3O4 onto the surface of lignite, making the surface morphology rougher, and the adsorption process of MML on Cu2+, Zn2+ and Pb2+ is related to the O-H stretching vibration of carboxylic acid ions and Fe-O stretching vibration of Fe3O4 particles.
Risk Factors Associated with Malaria Infection Identified through Reactive Case Detection in Zanzibar, 2012-2019
Authors: Mkali Humphrey Raphael , Reaves Erik J. , Lalji Shabbir M. , Al-mafazy Abdul-wahid , Joseph Joseph J. , Ali Abdullah S. , Abbas Faiza B. , Ali Mohamed H. , Hassan Wahida S. , Kitojo Chonge , Serbantez Naomi , Kabula Bilali I. , Nyinondi Ssanyu S. , Bisanzio Donal , McKay Mike , Eckert Erin , Reithinger Richard , Ngondi Jeremiah M.
Published: October 2021

BackgroundOver the past two decades, Zanzibar substantially reduced malaria burden. As malaria decreases, sustainable improvements in prevention and control interventions may increasingly depend on accurate knowledge of malaria risk factors to further target interventions. This study aimed to investigate the risk factors associated with malaria infection in Zanzibar. MethodsWe analyzed surveillance data from Zanzibar’s Malaria Case Notification system collected between August 2012 and December 2019. This system collects data from all malaria cases passively detected and reported by public and private health facilities, from household-based follow-up and reactive case detection activities linked to those primary cases. All members of households of the passively detected malaria cases were screened for malaria using a malaria rapid diagnostic test (mRDT); individuals with a positive mRDT result were treated with artemisinin-based combination therapy. Univariate and multivariate logistic regression analyses were done to investigate the association between mRDT positivity among the household members and explanatory factors (i.e., age, sex, history of fever, history of travel, rainfall, long-lasting insecticidal net [LLIN] density, LLIN use, household indoor residual spraying [IRS], and household location) with adjustment for seasonality ResultsThe findings show that younger age (p-value for trend<0.001), history of fever in the last two weeks (odds ratio [OR]=32.0; 95% CI: 29.1-35.3), history of travel outside Zanzibar in the last 30 days (OR=2.3; 95% CI: 2.1-2.6) and living in Unguja (OR=1.2; 95% CI: 1.1-1.3) were independently associated with increased odds of mRDT positivity. In contrast, male sex (OR=0.8; 95% CI: 0.7-0.9), having higher household LLIN density (p-value for trend<0.001), sleeping under an LLIN the previous night (OR=0.8; 95% CI: 0.7-0.9), and living in a household that received IRS in the last 12 months (OR=0.9; 95% CI: 0.8-0.9) were independently associated with reduced odds of mRDT positivity. A significant effect modification of combining IRS and LLIN was also noted (OR=0.7; 95% CI:0.6-0.8).Conclusions﻿The findings suggest that vector control remains an important malaria prevention intervention: they underscore the need to maintain universal access to LLINs, the persistent promotion of LLIN use, and application of IRS. Additionally, enhanced behavioral change and preventive strategies targeting children aged 5-14 years and travelers are needed.
Utilization of Long-lasting Insecticide Treated Net and Associated Factors Among Pregnant Women in Awabel District,North-West Ethiopia, 2017
Authors: Tariku Mengistie Kassahun
Published: October 2021

BackgroundUtilization of long-lasting insecticide treated net (LLITN) is one of the main vector control activities. It has a killing, repellent and physical barrier effects against mosquito. Even if priority is given for pregnant women, not all nets owned by household have been utilized by pregnant women. The objective of the study was to assess utilization of Long-lasting insecticidal net and associated factors among pregnant women in malarious kebeles, Awabel woreda, North-West Ethiopia.MethodsA community-based cross-sectional study was conducted from May 1 to June 30, 2017. A systematic random sampling was used to select 422 households. Two days training was given for data collectors and supervisors. Collected data were coded and entered using epi-data version 3.1, then it was exported to Statistical Package for Social Science (SPSS) version 20. After bivariate logistic regression analysis, all variables with a p-value less than or equal to 0.25was entered into multivariable logistic regression and p value < 0.05 considered as significantly associated with the outcome variable. ResultsUtilization of LLITN was 33.6%. Factors such as attending antenatal care [adjusted odd ratio (AOR) =1.89; 95% CI; 1.04-3.44], traveling <1 hour to reach health facility AOR=4.41; 95% CI; 2.06-9.43], age ≥ 35 year [AOR= 3.67; 95% CI; 1.36-9.95], knowledge [AOR=11.68; 95% CI; 5.96-22.89] and having positive attitude [AOR=3.12; 95 CI; 1.66-5.88] were significantly associated with utilization of LLITN.ConclusionThis study showed that low utilization of LLITN. Attending antenatal care (ANC), traveling <1 hour to reach health facility, age ≥ year, knowledge and attitude had positive association with LLITN utilization. Every concerned body should focus on reducing distance barrier by giving outreach services and increasing ANC, the attitude and knowledge of pregnant women toward malaria and LLITN which might increase utilization of LLITN.