bluuebunny/crossref_metadata_2025 huggingface dataset:
Smaller Epiphyseal Tubercle and Larger Peripheral Cupping in Slipped Capital Femoral Epiphysis Compared with Healthy Hips
Authors: Novais Eduardo N. , Maranho Daniel A. , Vairagade Amishi , Kim Young-Jo , Kiapour Ata
Published: October 2019

Background:

The inner surface of the capital femoral epiphysis is important for growth plate stability. However, abnormalities of epiphyseal morphology associated with the pathogenesis of slipped capital femoral epiphysis (SCFE) remain poorly understood. This study compares the 3-dimensional anatomy of the epiphyseal tubercle and peripheral cupping in hips with SCFE and normal hips.

Methods:

We created 3-dimensional models of the capital femoral epiphysis with use of computed tomography (CT) imaging from 51 patients with SCFE and 80 subjects without hip symptoms who underwent CT because of abdominal pain. The height, width, and length of the epiphyseal tubercle and the peripheral cupping were measured and normalized by the epiphyseal diameter and presented as a percentage. We used analysis of variance for the comparison of the measurements between SCFE and control hips after adjusting for age and sex.

Results:

Compared with normal hips, hips with mild SCFE had smaller mean epiphyseal tubercle height (0.9% ± 0.9% compared with 4.4% ± 0.4%; p = 0.006) and length (32.3% ± 1.8% compared with 43.7% ± 0.8%; p < 0.001). The mean epiphyseal tubercle height was also smaller in hips with moderate (0.6% ± 0.9%; p = 0.004) and severe SCFE (0.3% ± 0.8%; p < 0.001) compared with normal hips. No differences were observed for measurements of epiphyseal tubercle height and length between SCFE subgroups. The mean peripheral cupping was larger in hips with mild (16.3% ± 1.0%; p < 0.001), moderate (16.4% ± 1.1%; p < 0.001), and severe SCFE (18.9% ± 0.9%; p < 0.001) overall and when assessed individually in all regions compared with normal hips (10.6% ± 0.5%).

Conclusions:

Hips with SCFE have a smaller epiphyseal tubercle and larger peripheral cupping compared with healthy hips. A smaller epiphyseal tubercle may be a predisposing morphologic factor or a consequence of the increased shearing stress across the physis secondary to the slip. Increased peripheral growth may be an adaptive response to instability as other stabilizers (i.e., epiphyseal tubercle and anterior periosteum) become compromised with slip progression. Future studies are necessary to determine the biomechanical basis of our morphologic findings.
Impact of Reference Pricing on Cost and Quality in Total Joint Arthroplasty
Authors: Brodke Dane J. , Guo Chaoran , Aouad Marion , Brown Timothy T. , Bozic Kevin J.
Published: October 2019

Background:

Prices for total joint arthroplasty vary widely. Insurers have experimented with reference-based benefit designs (reference pricing) to control costs by setting a contribution limit that covers lower-priced facilities but necessitates higher out-of-pocket payments at higher-priced facilities. The purpose of this study was to evaluate the impact of reference pricing on the cost and quality of care for total joint arthroplasty.

Methods:

The California Public Employees’ Retirement System (CalPERS) implemented reference pricing for total joint arthroplasty in January 2011. We obtained data on 2,023 CalPERS patients who underwent total joint arthroplasty from January 2009 to December 2013 and comparison group data on 8,024 non-CalPERS patients from the same time period. Trends in 9 cost and quality-related metrics were compared between the CalPERS group and the comparison group: patient choice of a lower-priced hospital, insurer payment, consumer payment, 90-day complication rate, 90-day readmission rate, annual surgical volume of the chosen hospital, length of stay, travel distance, and rate of discharge to home. The impact of reference pricing was estimated with difference-in-differences multivariable regressions, adjusting for covariates.

Results:

An increase of 19 percentage points (95% confidence interval [CI], 13.0 to 25.6 percentage points; p < 0.01) in the selection of lower-priced hospitals was attributable to reference pricing, with a concurrent mean savings for the insurer of $5,067 (95% CI, $2,315 to $7,819; p < 0.01) and an increase in the mean patient out-of-pocket payment of $1,991 (95% CI, $1,053 to $2,929; p < 0.01). No significant change in any quality indicator was attributable to reference pricing, with the exception of an 8% reduction (95% CI, 3.3% to 12.7% reduction; p < 0.01) in the length of stay for hip replacement.

Conclusions:

Reference pricing motivates patients to choose lower-priced hospitals for total joint arthroplasty, with no measurable adverse impact on quality. Reference pricing represents a viable strategy in the shift toward value-based care.
Irrigation Fluids Used for the Prevention and Treatment of Orthopaedic Infections
Authors: Kavolus Joseph J. , Schwarzkopf Ran , Rajaee Sean S. , Chen Antonia F.
Published: October 2019

➤ Intrawound irrigation is a mainstay in the prevention and treatment of surgical site infections.

➤ There are 3 components of irrigation: delivery method, volume, and type of solution (with and without additives).

➤ A low-pressure delivery system for a 1 to 9-L volume of solution should be used to irrigate wounds, with a greater volume indicated in the setting of contaminated or infected wounds.

➤ Operative irrigation solutions are frequently supplemented with the addition of surfactants, antibiotics, or antiseptics.

➤ There is limited evidence with regard to the optimal antiseptic or whether antiseptics confer any advantage. Current literature suggests that surfactants and antibiotics should be avoided.

➤ To date, most studies on irrigation solutions in orthopaedics are retrospective, necessitating the organization of prospective randomized controlled trials to guide future evidence-based decisions.
Percutaneous Pinning of Pediatric Proximal Humeral Fractures
Authors: Swarup Ishaan , Hughes Michael S. , Bram Joshua T. , Horn B. David , Ganley Theodore J.
Published: October 2019

Background:

Proximal humeral fractures are relatively common in pediatric patients. These injuries are usually treated nonoperatively in younger children or children with minimally displaced fractures. However, closed reduction or open reduction followed by percutaneous pinning is recommended for older children with displaced fractures. Percutaneous pinning has several advantages, but there are limited reports of a safe and reliable surgical technique in the literature.

Description:

Patients are positioned in a modified beach-chair position to allow orthogonal imaging. The injured extremity is draped free from the remainder of the body. Closed reduction, which comprises a combination of traction, abduction, and rotation, is attempted. Internal or external rotation may be required, depending on the fracture line and deforming forces. If an anatomic closed reduction cannot be obtained, a block to reduction should be suspected and open reduction should be performed via a deltopectoral approach. Once the fracture is reduced, two 2.5-mm threaded Kirschner wires from the small external fixator set are used to percutaneously fix the fracture. Any small external fixator set can be used, and if not available, individual threaded wires of similar size can be used. Alternatively, Kirschner wires can be advanced to the fracture site prior to reduction and then advanced into the humeral epiphysis once the fracture is reduced. Care is taken to avoid the axillary nerve, which is reliably within 6 cm of the anterolateral aspect of the acromion, and wires are placed distal to this site. Once pin position has been confirmed radiographically, the construct is secured with pin-to-pin clamps to improve rigidity and further decrease the risk of pin migration. A soft dressing and shoulder immobilizer are placed postoperatively. Patients are followed with biweekly radiographs, and pins are removed in the outpatient office or under conscious sedation at 4 weeks. Leaving pins for a longer period may increase the risk of skin irritation and potentially infection.

Alternatives:

Alternatives to closed reduction or open reduction and percutaneous pinning include nonoperative management and elastic intramedullary nailing. Nonoperative treatment is a reliable option for most patients. However, it is not suitable for older children with severely displaced fractures because of diminished remodeling potential. Elastic intramedullary nailing is a good option for distal fractures. However, it is not suitable for proximal fractures, and it has been associated with longer operative times and more blood loss than percutaneous pinning. It also requires a second procedure.

Rationale:

This procedure allows for anatomic fixation of proximal humeral fractures and provides a rigid construct to maintain reduction. It is not technically challenging, requires limited postoperative immobilization, and decreases the risk of a second general anesthetic.
Efektivitas Pupuk Hayati Mikoriza Berbasis Azolla (Mikola) Pada Tanaman Bawang Merah (Effectiveness Of Biofertilizer Mycorrhiza Based Azolla (Mikola) On Shallot)
Authors: Rokhminarsi Eny , Utami Darini Sri , Begananda NFN
Published: October 2019

Bawang merah merupakan jenis sayuran umbi yang potensial secara ekonomi. Produksi dan harganya yang fluktuatif menjadikan komoditas ini perlu mendapat perhatian yang serius, khususnya untuk pengembangan budidayanya ke lahan marjinal yang masih luas di Indonesia. Tujuan penelitian adalah menerapkan bioteknologi pupuk hayati mikoriza spesifik lokasi lahan marjinal berbasis azolla (Mikola) dan pengurangan dosis pupuk anorganik pada budidaya tanaman bawang merah. Metode penelitian berupa percobaan pot di rumah plastik menggunakan rancangan Central Composit Second Order Design dengan 2 faktor. Faktor pertama, dosis pupuk Mikola yaitu 6, 12, 18, 24, 30 g tanaman-1 dan faktor kedua adalah pengurangan dosis pupuk anorganik Urea, ZA, SP 36 dan KCl yaitu 20%, 40%, 60%, 80% dan 100% dari dosis anjuran. Analisis dilakukan dengan metode Respon Surface Methodology (RSM) dengan model persamaan matematika : Yi= β0X0 + β1X1 + β2X2 + β11X1² 1+ β22X2² +β12X1X2 + εij dengan bantuan program minitab16. Kesimpulan dari penelitian ini menunjukkan bahwa aplikasi pupuk Mikola pada budidaya tanaman bawang merah di pot dengan dosis 18 gram per tanaman dapat mengurangi pemakaian pupuk anorganik hingga 40% dari dosis rekomendasi dan meningkatkan hasil hingga 15%.

Keywords

Mikoriza, azolla, pupuk hayati, bawang merah, sayuran

Abstract

Shallots is a kind of tuber vegetable economic potential. Production and the price fluctuating commodity makes it necessary for serious concer, particularly for the development of cultivation into marginal land that is still widespread in Indonesia. The objective of research was to apply of biofertilizer mycorrhizal marginal land of azolla based (Mikola) and dose reduction of inorganic fertilizers in the cultivation of shallot. The research was pot experiment using the Central Composite Second Order Design with 2 factors. The factors are the dose of Mikola namely 6, 12, 18, 24, 30 g plant-1 and reduction of Urea, ZA, SP 36, KCl i.e. 20%, 40%, 60%, 80% and 100% of recommended doses. The analysis using Response Surface Methodology, a mathematical equation: Yi= β0X0 + β1X1 + β2X2 + β11X1² 1+ β22X2² +β12X1X2 + εij. The conclusion showed that the application of Mikola fertilizers on the shallot planting with 18 grams per plant can eliminate the use of inorganic fertilizers up to 40% of the dose recommendation and increase the yield up to 15%.
Pengujian Mutu Benih Cabai (Capsicum annuum) Dengan Metode Uji Pemunculan Radikula [Seed Quality Test in Pepper (Capsicum annuum) Seeds Using Radicle Emergence]
Authors: Kusumawardana Aditya , Pujiasmanto Bambang , Pardono NFN
Published: October 2019

Kecepatan berkecambah yang rendah merupakan indikator kemunduran benih. Pengujian vigor dengan metode uji pemunculan akar pada benih cabai dilakukan untuk menduga pertumbuhan tanaman di lapangan. Makin tinggi nilai uji pemunculan akar maka vigor benih makin tinggi. Jika laju pemunculan radikula pada benih berjalan lambat, vigor benih tersebut dinyatakan rendah. Tujuan penelitian ini adalah membandingkan jumlah kemunculan radikula pada empat lot benih cabai pada suhu berganti 2030°C selama 168 jam. Penelitian ini menggunakan rancangan acak lengkap dengan satu faktor, yaitu lot benih berupa empat varietas cabai (Sret, Laskar, Serambi, dan Madun) dengan delapan ulangan. Perhitungan koefisien korelasi dilakukan untuk mengetahui keeratan hubungan antara nilai uji pemunculan radikula dengan tolok ukur pengujian yang lain. Hasil penelitian menunjukkan bahwa kemunculan radikula tertinggi terjadi pada 120 jam. Jumlah pemunculan radikula berkorelasi positif dengan daya berkecambah (r=0,907), indeks vigor (r=0,864), kecepatan tumbuh (r=0,727), dan daya tumbuh (r=0,935). Dari penelitian ini diperoleh kesimpulan bahwa uji vigor pemunculan radikula benih cabai yang dilakukan pada suhu 2030°C selama 120 jam (5 hari) dapat digunakan untuk menilai mutu benih cabai.

Keywords

Benih cabai; Daya tumbuh; Mutu benih; Pemunculan radikula

Abstract

Low germination is an indicator of seed deterioration. Vigour testing using radicle emergence on pepper  seeds was done to predict plant growth in field. The higher radicle emergence found, the higher the seed vigour occurred. If the rate of radicle was slow, the seed vigour was also low. The objective of this study was to compare the number of radicles emergence on four pepper seed lots at 2030°C for 168 hours. This study used a completely randomized design with one factor, seed lot four variety of pepper (Sret, Laskar, Serambi, and Madun) with eight replication. Calculation of coefficients correlation was done to calculate the relationship between radicle emergence and on other testing. The highest of radicles emergence occurred at 120 hours. The number of radicle emergence had positive correlation with germination (r = 0.907), vigour index (r = 0.864), speed of growth (r = 0.727), and field emergence (r = 0.935). From this research, it can be concluded that the vigour test in pepper seeds using radicle emergence was performed at 2030°C for 120 hours (5 days).
Controlling Factors of Shale Gas Production: What can Artificial Intelligence Tell Us?
Authors: He Qin , Bruno Jonathan , Zhong Zhi
Published: October 2019

Application of horizontal drilling and hydraulic fracturing technique has made development of shale gas reservoir successful in the United States during the past decade. Chasing its operational success, researchers have been studying to understand the fundamentals of shale gas production, which will provide valuable information to assist in optimization of shale reservoir development. Unfortunately, the mechanism of shale gas production has not been fully revealed so far, and most reservoir simulation models are adopting the mechanism of coalbed methane production to forecast shale gas development process, which might not be the real case.

In this paper, instead of using numerical simulation model, artificial intelligence and data mining techniques are implemented to study the controlling factors of shale gas production and understand the impacts of reservoir, completion and stimulation parameters in a dynamic manner only according to the field data. A database of Marcellus shale reservoir is generated by integrating information such as well locations, well trajectories, reservoir characteristics, completion, hydraulic fracturing, and production parameters, etc. Neural network models are trained to learn the key performance impacting factors on shale gas production in a dynamic manner, which could assist reservoir management decisions.
Modeling and Optimization of Gas-Assisted Plunger Lift GAPL by a Transient Simulator: A Case Study of a Permian Shale Well
Authors: Kannan Subash K , Boyer Matthew , Yuan Ge , Lu Haidan , Fai-Yengo Ghislain
Published: October 2019

Gas-assisted plunger lift (GAPL) could be an effective and economically favorable artificial lift (AL) method to be considered during the AL life cycle for North American shale wells. The main advantage of GAPL is that it improves the well production by reducing liquid fallback and boosts the plunger efficiency through gas injection and increases the gas lift efficiency by assisting in delivering the slugs to the surface. The objective of this study is to capture the GAPL dynamic behavior through a transient multiphase flow simulator. The entire GAPL production cycle was modeled, including plunger fall, gas injection, pressure buildup, and production. First, the GAPL well production history was analyzed to evaluate the well operating condition. Then, a transient simulator was used to model the well flow behavior and production performance with GAPL. The study demonstrated the GAPL impact on flowing bottomhole pressure and the improvement in the well productivity.

A Delaware Basin well case study demonstrates the benefits of dynamic modeling and provides a comprehensive comparison between dynamic simulation results and field data. The simulation work provides insights into the fluid flow, GAPL behavior, and pressure and rate transients of a GAPL well.

The modeling results were validated against field data. A commercially available transient multiphase flow simulator was used and produced outcomes that were in alignment with field data collected. The dynamic plunger cycles were reproduced in the simulation, and the results showed the benefits of GAPL in a typical shale oil well. This could extend the gas lift life by delaying the transition to rod pumps or potentially act as an end-of-life AL solution. In the long term, this reduces the overall AL life cycle cost. The use of transient simulation helps validate AL design concepts, especially for unconventional wells where the flow behavior is very dynamic. This study encourages the use of this analysis in the AL selection workflow to help optimize the overall AL life cycle cost and maximize the net present value (NPV).
Comprehensive Review of Artificial Lift System Applications in Tight Formations
Authors: Kolawole Oladoyin , Gamadi Talal , Bullard Denny
Published: October 2019

The artificial lift system (AL) is the most efficient production technique in optimizing production from unconventional horizontal oil and gas wells. Nonetheless, due to declining reservoir pressure during the production life of a well, artificial lifting of oil and gas remains a critical issue. Notwithstanding the attempt by several studies in the past few decades to understand and develop cutting-edge technologies to optimize the application of artificial lift in tight formations, there remains differing assessments of the best approach, AL type, optimum time and conditions to install artificial lift during the life of a well. This report presents a comprehensive review of artificial lift systems application with specific focus on tight oil and gas formations across the world. The review focuses on thirty-three (33) successful and unsuccessful field-tests in unconventional horizontal wells over the past few decades. The purpose is to apprise the industry and academic researchers on the various AL optimization approaches that have been used and suggest AL optimization areas where new technologies can be developed.
New OCTG Developments to Overcome Challenges in Unconventional Plays
Authors: Blanc Carlos , Lewis Josh , Ichim Adonis , Mutis David , Zestran Alexandru , Lucca Carlos Ignaccio , Perello Leandro
Published: October 2019

Research and development drives success in shale plays throughout the world, enabling operators to deploy new drilling, completions, and production technologies to reach more reservoir area and extend the life of production wells. This work demonstrates the development, validation, and deployment of an extreme torque casing connection addressing technical challenges of tubulars in unconventionals.

Throughout the well lifetime, Oil Country Tubular Goods (OCTG) experience various loads during the installation, stimulation, and production phases. Some of the challenges experienced during the stimulation and production phases relate to internal and external pressure resistance, sealability, corrosion and cracking, erosion, and wear. Furthermore, with the increase in lateral length and the more demanding well geometries, the OCTG capabilities related to high cycle fatigue, connection runability, and torque limits become more important to safely and efficiently reach the total depth of the well and ensure integrity throughout well life. Another scenario in which the torque limit of an OCTG connection is important is rotating while cementing, a practice undertaken to mitigate sustained casing pressure, improve well integrity, and completion efficiency.

We present the key elements in the development of a casing connection that overcomes these challenges and the decision process leading to a prototype. To prove the design concept, a fit-for-purpose testing protocol was adopted to validate its performance, replicating the installation, stimulation, and production phases under the expected loads. Once validated, a pilot involving casing installation, rotation while cementing and stimulation was completed in two wells, and its outcomes will be discussed in this work.

This novel casing extreme torque connection, designed to overcome the application challenges, enables the installation of casing in longer laterals, together with the improvement of well integrity through rotation while cementing.

The performance of the product, tested through a special procedure while ensuring reliability, was confirmed by the case study from the Niobrara shale. A new connection considering the challenges of wells in unconventional plays must account for several aspects from design to installation. We show the process, from the design stage and validation, leading to successful field deployment.
Refined Drill Bit Technology for Underbalanced Drilling in the Northeast United States
Authors: Goodman Aaron J. , Grimes Robert E. , Lane Christopher W.
Published: October 2019

Underbalanced drilling via air drilling is deeply rooted in the Northeast United States due to its distinct geology, high rates of penetration (ROP) and drilling efficiency, and low cost of circulating material. The active drilling programs of several independent operators in the Marcellus and Utica Basins are well suited for air drilling down to the final kick off point by virtue of competent, stable formations, low static reservoir pressures, and manageable water ingress to the wells. Air drilling provides near-atmospheric pressure at the borehole bottom, since there is no fluid column with resulting hydrostatic pressure. The result is very high ROP with essentially 100% drilling efficiency, allowing the completion of intervals in one or two bit runs. A service company deployed a cross-functional product development team to optimize oilfield air bits for these applications over the last two years, resulting in decreased drilling costs through increased performance and reliability.

The oilfield air drilling environment places unique challenges on drill bit design due to the increased risk of downhole vibrations, corrosion, abrasive wear, heat generation, and seal infiltration of very fine cuttings. The application requirements have increased due to deeper intervals requiring passage through multiple high unconfined compressive strength formations, extended tangent angles, and rising input energy levels. Accordingly, enhancements to both the cutting structures and sealed bearing systems were vigorously pursued. Several cutting structure design iterations were evaluated in both laboratory and field tests. A new sealed bearing system was developed and implemented for increased life and reliability. Modifications to the bit body for stability were included, and the bit hydraulics were further optimized.

Through an understanding of the objectives and application challenges, unique solutions were developed for Northeast oilfield air drilling applications. The optimization process for the new air bit designs is described, and the resulting positive performance metrics are presented. Improvements were observed in distance drilled, ROP, seal effective rate, and dull condition. Lessons learned were also used to refine the recommended drilling parameters and practices through the challenging formations encountered in these tangent sections, which can span in excess of 7000 feet. These enhancements all contributed to reduced drilling cost and days per well, for increased rig productivity.

The natural gas fields throughout the Marcellus and Utica Basins in the Northeast U.S. continue to deliver rising total gas production for the U.S. and the world through increased capacities in pipelines and LNG trains. Improved drilling performance as documented in this paper are driving continuous improvement in the overall upstream drilling economics of the region.
Re-Fracturing the Appalachian Basin: An Economic Analysis
Authors: Kiselica Kade , Jennings Taylor
Published: October 2019

In the past ten years, hydraulic fracturing technology and strategies have made major improvements in the operational efficiency and economic performance of shale well completions. Much of this advancement was derived in the past three years as a response to the global downturn in oil and gas commodity pricing. Mature shale plays across the United States have a surplus inventory of horizontal wells employing highly inefficient completions styles. Amid the low oil pricing environment, operators in the Bakken and Eagle Ford were capable of revitalizing these prior generation wells with great success through re-fracturing programs. In many cases, production of these re-fractured wells rivaled the production of newly drilled and completed shale wells both in terms of initial production post re-fracture as well as extended interval cumulative production. These re-fracturing programs allowed producers to achieve tremendous gains in production while minimizing drilling activity. Although re-fracturing began as a highly economical method to improve production during a time of depressed oil pricing, it is still being used today to improve the production of additional wells recognized as top-tier candidates.

By developing a specific set of criteria to select wells for re-fracturing, these programs can be successfully employed in the Appalachian Basin to improve the economics of gas wells, mitigating the effects of highly discounted natural gas pricing. After the explanation of well candidacy, an economic sensitivity analysis was implemented to illustrate the impacts a strong re-fracturing program could make for operators in the Northeast through a comparison of public data showing production and total reserves for both in and out-of-basin re-fracturing programs. Additionally, while this paper focuses on re-fracturing as it relates to shale formations it also includes information as to how re-fracturing relates to conventional formations.

After looking at the incremental economics of re-fracturing programs implemented in shale plays across the United States and in-basin data, the impacts of gas well re-completion can be fully quantified and understood through the application of probabilistic modeling. Additionally, this modeling further delineates re-completion candidacy by identifying which wells pose higher risks in economic metrics.

Very little information has been published regarding the impacts a re-fracturing program could have in the Appalachian Basin. As the field matures, the topic of re-completions will become increasingly important, and this analysis will allow operators to have a greater understanding of the impacts of refracturing shale gas wells in the Northeast.
Applying Field-Proven Surface Modified Proppant SMP to Increase Gas Production: A Case Study from Marcellus Shale
Authors: Bammidi Vidya Sagar , Mortazavi Millad , McClure Mark , Kakadjian Sarkis , Sobernheim Dave
Published: October 2019

In shale formations, operators are constantly seeking new technologies to improve proppant transport and conductivity in order to boost production. A novel technique known as surface modified proppant (SMP) has been pumped in more than a dozen wells in the United States, with proven results of increased production. This paper demonstrates and analyzes a case study for a Marcellus shale development where two wells are presented. Well A applied the SMP technique while the offset, Well B, was stimulated without the technology. After three years, Well A yielded an 18% increase in normalized cumulative gas production over the offset Well B.

In presenting the benefits of this technique, the paper provides a brief overview of the development of the conductivity enhancer; the case study; 3D reservoir and hydraulic fracturing simulator selection; model setup and simulation results. SMP is a chemical additive that, when pumped, creates a buoyancy effect of proppant particles upon entering the fracture network. This dynamic SMP application also propels proppant transportation, prevents proppant settling and enhances the fracture network conductivity by increasing the volume by which sand inhabits the fracture network. Increasing the proppant pack height enables deeper penetration into the fracture network, allowing for an increase in proppant distribution and ultimately enhancing the stimulated rock volume (SRV). We have been able to prove the application in both the lab and field scale tests. The impact of the SMP proppant is investigated by performing numerical simulations of hydraulic fracturing and subsequent production.

Along with clear results showing better proppant placement using the simulator with the conducted study, we further explain the completion effectiveness. We outline advantages and the ease of pumping the SMP, including design optimization, thus making this technology cost beneficial.
Analyses of Multiple Pressure Drops on the Potential Productivity of Shale Wells
Authors: Gorell Sheldon , Browning Jim , Andrews Justin
Published: October 2019

Production from shales can be dependent on many things, including multiple reservoir properties, drilling, completion and production methods. Designs and analyses often focus on drilling and completion issues, such as number of stages, wellbore length and fracture properties, such as conductivity, length, spacing and complexity. As a result, many aspects of the reservoir, fractures and production methods can be significant. Flow from the reservoir to production points is driven by pressure drops. If an entire well including fractures and surrounding reservoir is considered as a single system, then the production behavior is driven by the magnitude of three pressure drops and corresponding resistances to flow in the system. Those that need to be considered are: pressure drop between the reservoir and the fractures, pressure drop along the fractures to the wellbore perforations and pressure drop along the wellbore to the pump inlet or tubing head. Different aspects of the well/fracture/reservoir system become important, or unimportant, depending on the relative magnitude of these pressure drops and resistances to flow. For example, many people believe that fractures should be as long as possible assuming they can be restricted to zones of interest and do not interfere with other wells and/or fractures. However, since the pressure along a fracture increases as you move further away from the wellbore, increasing fracture length can have diminishing returns for reservoirs with small reservoir to fracture pressure drops and/or low fracture conductivities. Similar effects pertain to number of fractures, fracture spacing and wellbore lengths. This paper analyzes effects of different reservoir, fracture and wellbore properties and the influence of different pressure drops on shale well productivity.
Improved Analysis of Stimulated Reservoir Volumes in Unconventional Reservoirs Using Supervised Learning Techniques
Authors: Tandon Saurabh
Published: October 2019

"Sweet spots" in the unconventional reservoirs such as organic-rich mudrocks are zones with high productivity. However, identifying such regions in unconventional reservoirs depends non-only on their petrophysical and but also on their geomechanical properties. Supervised learning methods can help in integrating numerical simulation and legacy field data in sweet-spot identification workflows and enhance their analysis in complex reservoirs. The objectives of this paper are to: (i) demonstrate the use of supervised learning in parameter selection and evaluation for fracture design and (ii) provide non-linear models for sweet-spot analysis in complex reservoirs.

We used fracture simulator that combines with fracture deformation with fluid-flow in discrete fracture networks. We started by selecting different geomechanical rock properties related to its fracability. We then used quasi-random design approach to obtain wide variation in aforementioned properties and performed 200 fracture simulations using the hydraulic fracturing simulator. We used the short-term Stimulated Reservoir Volumes (SRV) obtained at the end of numerical simulations, to quantify the performance of hydraulic fracturing operations. We used supervised learning techniques like support vector machines, decision trees, and random forests to perform parameter ranking and create non-linear regression models that can correlate the SRV to formation geomechanical properties.

The inputs for the analysis are: initial aperture, toughness, dilation angle, closure stress, and friction coefficient of initial fractures, stress anisotropy, shear modulus and a ratio of the reservoir rock. We analyzed the results using β-linear and multinomial regression, support vector machines, decision trees, and random forests. The linear models and non-linear models can explain up to 89.1% of output variance. The classification accuracy of support vector machines was at most 35% higher than other algorithms like random forests. Parameter rating using non-linear models showed that stress anisotropy and dilation angle demonstrated the highest effect on SRVs. Shear modulus and fracture toughness show minimal effect on the SRV but these parameters might still be useful they could be correlated to other formation parameters.

The outcomes of this paper demonstrated that parameters pertaining to unpropped fracture conductivity play a significant role in determining the success of hydraulic fracturing treatments. We have also compared the performances of supervised machine learning algorithms in assessing the impact of rock properties on fracturing treatments. Such supervised machine learning algorithms can help integrate field legacy data and numerical simulation outputs to develop proxy models that improve sweet-spot analysis and production estimates in unconventional reservoirs.
Evaluation of Reservoir Compartmentalization Through Organic Geochemistry jawdah Field, South of Oman
Authors: Al Shukairi Saleem Abdullah
Published: October 2019

As the oil and gas industry has been investigating the challenges in identifying reservoir compartmentalization and interpreting the negative influences it generates, diverse disciplines within the oil and gas industry have presented beneficial approaches to inspect and reduce the challenges found while exploring and appraising oil fields. despite the various pieces of literature that have been published in this field stating that reservoir compartments are either structurally or stratigraphically in origin depending on the depositional facies or fault geometry. This study presents, geochemical data from twenty oil samples which are used to investigate horizontal and vertical compartmentalization of the Jawdah Field, which is located in the south of Oman. The data were intended to identify the causes of the segmentation using fluid properties. The results from each oil sample are integrated with carbon isotopes, whole-oil gas chromatography, saturates, aromatics, resins and asphaltenes (SARA) analysis and biomarkers in order to detect different variations in fluid composition that may be lead to better understanding of reservoir compartmentalization. Based on these four analyses, the research findings indicate that Jawdah oils are derived from a single source rock (Huqf oils). The identification of the Huqf source rock was based on the similarities between pristane and phytane peaks from the whole-oil gas chromatography data and the carbon isotopes for the Jawdah oils and from the Grantham (1988) paper. However, the API gravities in Jawdah field varied ranging from light to moderately heavy oil (20-33 API), indicating a possibility of other geological factors affected the alteration of the crude oil. Therefore, these oils were further characterized by interpreting the level of maturation and biodegradation ratios using biomarker signatures. This combination of methods has provided a more advanced method of investigating and interpreting compartmentalized reservoirs and it will lead to enhancing recovery. It was found that the Gharif and Al Khlata reservoir units are not in communication, potentially impacting well design, and field development planning.
Trial Forge Guidance 2: How to decide if a further Study Within A Trial (SWAT) is needed
Authors: Treweek Shaun , Bevan Simon , Bower Peter , Briel Matthias , Campbell Marion , Christie Jacquie , Collett Clive , Cotton Seonaidh , Devane Declan , Feky Adel El , Galvin Sandra , Gardner Heidi , Gillies Katie , Hood Kerenza , Jansen Jan , Littleford Roberta , Parker Adwoa , Ramsay Craig , Restrup Lynne , Sullivan Frank , Torgerson David , Tremain Liz , von Elm Erik , Westmore Matthew , Williams Hywel , Williamson Paula R , Clarke Mike
Published: October 2019

The evidence base available to trialists to support trial process decisions– e.g. how best to recruit and retain participants, how to collect data or how to share the results with participants – is thin. One way to fill gaps in evidence is to run Studies Within A Trial, or SWATs. These are self-contained research studies embedded within a host trial that aim to evaluate or explore alternative ways of delivering or organising a particular trial process. SWATs are increasingly being supported by funders and considered by trialists, especially in the UK and Ireland. At some point, increasing SWAT evidence will lead funders and trialists to ask : given the current body of evidence for a SWAT, do we need a further evaluation in a another host trial? A framework for answering such a question is needed to avoid SWATs themselves contributing to research waste. This paper presents criteria on when enough evidence is available for SWATs that use randomised allocation to compare different interventions.
Seroprevalence of Hepatitis B Virus among antenatal clinic attendees in Gamawa Local Government Area, Bauchi State, Nigeria
Authors: MUSTAPHA GARBA UMAR , Ibrahim Abdulrasul , Balogun Muhammad Shakir , Umeokonkwo Chukwuma David , Mamman Aisha Indo
Published: October 2019

Background: Hepatitis B is a potentially life-threatening liver infection and a major global health problem. It causes chronic infection and puts people at high risk of death from cirrhosis and liver cancer. WHO estimated 257 million people are living with hepatitis B virus (HBV) infection and in 2015 alone HBV resulted in to 887,000 deaths globally. We determined the prevalence and associated factors of hepatitis B virus infection among Antenatal Care (ANC) attendees in Gamawa Local Government Area, Bauchi State. Methods: We conducted a descriptive cross-sectional, health facility-based study between March and April 2018. We used systematic random sampling technique to recruit 210 pregnant women aged 15-49 years. With a structured questionnaire, we interviewed the respondents and collected blood sample to test for hepatitis B surface antigen. We calculated frequencies, means, proportions, and tested for associations using Epi Info 7.2 and Microsoft Excel. Results: The mean age of respondents was 24.5 ± 6.0 years; 112 (53%) of whom were younger than 25 years. All were married, 183 (87%) had no formal education and up to 190 (90%) were employed. Overall, 14 (6.7%) tested positive for HBsAg; women aged ≥35 years had the highest prevalence (10%). None with tertiary education tested positive and women married before 18 years had 13 (6.2%) prevalence. Conclusions: The prevalence of HBsAg among pregnant women in Gamawa LGA was 6.7% which is quite lower than the national prevalence reported. We recommended improved surveillance of HBV infection and screening of women attending ANC. Keywords: Hepatitis B virus, Hepatitis B Surface antigen, Prevalence, Pregnancy, Health facilities, Hepatitis B
A Sense of Place: Transcriptomics Identifies Environmental Signatures in Cabernet Sauvignon Berry Skins in the Late Stages of Ripening.
Authors: Cramer Grant R. , Cochetel Noé , Ghan Ryan , Destrac-Irvine Agnès , Delrot Serge
Published: October 2019

Background Grape berry ripening is influenced by climate, the main component of the “terroir” of a place. Light and temperature are major factors in the vineyard that affect berry development and fruit metabolite composition. Results To better understand the effect of “place” on berry ripening, transcript abundances in Cabernet Sauvignon berries grown in Bordeaux were compared to those in Reno during the late stages of berry development at similar berry sugar levels (19 to 26 °Brix, total soluble solids (TSS)). Day lengths were similar in both locations but day temperatures were warmer and night temperatures were cooler in Reno. TSS was lower in Bordeaux berries compared to Reno at maturity levels considered optimum for harvest. RNA-seq analysis identified 4,455 differentially expressed genes (DEGs) between Bordeaux and Reno grape skins at 22°Brix. Top DEG gene ontology categories involved response to stimulus (1464 genes), biosynthesis (1260 genes) and response to stress (834 genes). Some DEGS included genes encoding terpene synthases, cell wall enzymes, kinases, transporters, transcription factors and photoreceptors. Most circadian clock genes had higher transcript abundance in Bordeaux. The plant temperature sensor phytochrome B was linked with Reveille 1 expression, which is part of the circadian clock output pathway that affects seed dormancy. Bordeaux berries had higher transcript abundance with DEGs associated with seed dormancy, light, auxin, ethylene signaling, powdery mildew infection, phenylpropanoid, carotenoid and terpenoid metabolism, whereas Reno berries were enriched with DEGs involved in water deprivation, cold response, ABA signaling and Fe homeostasis. Conclusions Transcript abundance profiles in the berry skins at maturity were highly dynamic. RNA-seq analysis identified a common core set of ripening genes that do not depend on rootstock, vineyard management, plant age, soil and climatic conditions. Most DEGs could be associated with different environmental conditions that affected the berries in the two locations and may be potentially controlled in different ways by the vinegrower to adjust final berry composition and reach a desired result. Temperature, light, water status and fungal infection were identified to be some of the most influential factors that affected differential gene expression and the quality trait pathways associated with them.
Chronic Hypersensitivity Pneumonitis In The Southeastern United States: An Assessment Of How Clinicians Reached The Diagnosis
Authors: Gu Jessie , Tsai Chen-Liang , Wysham Nicholas , Huang Yuh-Chin Tony
Published: October 2019

Background: Chronic hypersensitivity pneumonitis (cHP) is a disease caused by exposure to inhaled environmental antigens. Diagnosis of cHP is influenced by the awareness of the disease prevalence, which varies significantly in different regions, and how clinicians utilize relevant clinical information. We conducted a retrospective study to evaluate how clinicians in the Southeast United States, where the climate is humid favoring mold growth, diagnosed cHP using items identified in the international modified Delphi survey of experts, i.e., environmental exposure, CT imaging and lung pathology, Methods: We searched Duke University Medical Center database for patients over the age of 18 with a diagnosis of cHP (ICD-9 code: 495) between Jan. 1, 2008 to Dec. 31, 2013 using a query tool, Duke Enterprise Data Unified Content Explorer (DEDUCE). Results: Five hundred patients were identified and 261 patients had cHP confirmed in clinic notes by a pulmonologist or an allergist. About half of the patients lived in the Research Triangle area where our medical center is located, giving an estimated prevalence rate of 6.5 per 100,000 persons. An exposure source was mentioned in 69.3% of the patient. The most common exposure sources were environmental molds (43.1%) and birds (26.0%). We used Venn diagram to evaluate how the patients met the three most common cHP diagnostic criteria: evidence of environmental exposures (history or precipitin) (E), chest CT imaging (C) and pathology from lung biopsies (P). Eighteen patients (6.9%) met none of three criteria. Of the remaining 243 patients, 135 patients (55.6%) had one (E 35.0%, C 3.3%, P 17.3%), 81 patients (33.3%) had two (E+C 12.3%, E+P 17.3%, C+P 4.9%), and 27 patients (11.1%) had all three criteria (E+C+P). Overall, 50.6% of patients had pathology from lung biopsy compared to 31.6% with CT scan. Conclusions: Environmental mold was the most common exposure for cHP in the Southeast United States. Lung pathology was available in more than half of cHP cases in our tertiary care center, perhaps reflecting the complexity of referrals. Differences in exposure sources and referral patterns should be considered in devising future diagnostic pathways or guidelines for cHP.
Occurrence and seasonal variation of human Plasmodium infection in Punjab Province, Pakistan
Authors: Qureshi Naveeda Akhtar , Fatima Huma - , Afzal Muhammad , Khattak Aamer Ali , Nawaz Muhammad Ali
Published: October 2019

Background:
Background: Malaria is the fifth leading cause of death worldwide. Pakistan is considered as a moderate malaria-endemic country but still, 177 million individuals are at risk of malaria. Roughly 60% of Pakistan’s population, live in malaria-endemic regions. The present study is based upon the survey of various health care centers in 10 major cities of Northern and Southern Punjab to find out the malarial infection patterns in 2015. The diagnosis, seasonal variations, age and gender-wise distribution of Plasmodium spp. circulating in the study area were also included in the objectives.
Methods: The malaria-suspected patients ‘16075’ were enrolled for malaria diagnosis using microscopy, out of which 925 were malaria positive which were processed for molecular analysis using nested PCR. The 18S rRNA genes of Plasmodium species were amplified, sequenced, blast and the phylogenetic tree was constructed based on sequences using online integrated tool MEGA7.
Results: The 364 cases recruited from Northern Punjab with the highest incidence in Rawalpindi (25.5%) and lowest in Chakwal (15.9%). From Southern Punjab 561 cases were enlisted Rajanpur (21.4%) maximum and lowest from Multan and Rahim Yar Khan (18%). The slide positivity rate, annual parasite incidence, and annual blood examination rates were 5.7 per 1000 population, 0.1%, and 0.2% respectively. The only P. vivax (66.7%), P. falciparum (23.7%) and mixed infection by these two species (9.6%) were diagnosed. The same trend ( P. vivax > P. falciparum > mixed infection) in species identification %age was confirmed from molecular analysis. However, the occurrence of malaria was higher in Southern Punjab (5.5%) as compared to the Northern Punjab (4.0%). The overall malaria percentage occurrence of treatment-seeking patients in all recruited cities of Punjab was 4.9%. The age-group of 1-20 and males among genders were more affected by malaria. The comparison of different seasons showed that the malaria infection was at a peak in Summer and post-monsoon.
Conclusion: The incidence of malaria was high in the flood infected rural areas of Southern Punjab, Summer, and post-monsoon. The age group (1-20) and gender-wise males were more affected by malaria.