bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on microwave heating structure optimization of auxiliary material box of road maintenance vehicle
Authors: Gao Kangping , Wei Xiaoyu , Jiao Shengjie , Li Jiabo , Wei Meng
Published: September 2020

The arrangement and spacing of microwave comprehensive maintenance vehicle antenna array directly affect the heating efficiency and heating uniformity of asphalt mixture. In order to improve the heating uniformity of asphalt mixture, this paper proposes a microwave heating structure based on auxiliary materials box, and optimizes the microwave heating structure of auxiliary materials box of road maintenance vehicle through CST simulation platform. Firstly, in the way of side-by-side arrangement of the antenna array, the spacing of the antenna array is optimized, and the heating uniformity of the asphalt mixture in the auxiliary material box is the best when the spacing is 132mm×155mm under side-by-side arrangement. Then, under the optimal arrangement spacing, the orthogonal arrangement of antenna array was put forward, and it was concluded that under this arrangement, the heating uniformity of asphalt mixture increased by 12.1%, and the proportion of asphalt mixture increased by 8.7% at 80°C -160°C. This conclusion has certain reference value to the improvement of the heating effect of the auxiliary material box heating system.
An obstacle avoidance design of UAV based on genetic algorithm
Authors: Hu Xusheng , Liu Juan
Published: September 2020

In order to improve the effect of obstacle avoidance, a PID control algorithm combined with genetic algorithm is proposed. By establishing the mathematical model of UAV, the auxiliary control system of UAV is analyzed, and then the control system is optimized by genetic algorithm. Taking STM32 as the control platform, the obstacle avoidance experiment was carried out by building the experimental platform. The experimental results show that the algorithm can avoid obstacles effectively.
High-precision spot positioning algorithm based on four-quadrant detector
Authors: Xiao Meifang , Zhang Yanmei , Li Huan
Published: September 2020

Inherent errors and random errors are consisting in four-quadrant detector when used for azimuth measurement. Many spot fitting algorithms are proposed to solve the inherent errors caused by the structure of the four-quadrant detector itself, which can reduce the errors in a way. In order to further improve the spot positioning accuracy and eliminate the influence caused by random errors such as background light and thermal noise, we first perform Kalman filtering on the output of the four quadrants when we perform experiments to calibrate parameters. Build an experimental platform, and experimentally verify that the Kalman filtering of the output of the four quadrants before bringing in the spot positioning algorithm can improve the accuracy of the composite fitting algorithm, thereby improving the positioning accuracy.
Wireless indoor localization using convolutional neural network
Authors: Qu Tianqi , Li Meng , Liang Dong
Published: September 2020

This paper provides a wireless localization method using convolutional neural networks (CNN) and based on WIFI fingerprinting data. We pre-processed WIFI fingerprinting data from Jaume I University public database and used it to train our CNN model. A WIFI fingerprint is composed of a series of received signals’ strength (RSS) released by many access points (APs). We changed the RSSs’ value at the edge of the signal disappearance. This operation can help the CNN model extract the features of fingerprints and have a better performance. After this operation, a CNN model can have about 21.2% lower loss and 23.5% higher accuracy than usual. Changing edge RSS is shown to be a good way to improve the performance of indoor localization.
Application research of adaptive fuzzy control in the treatment device of drilling fluid wastewater
Authors: Meng Minghui , Zhou Chuande , Gao Xiaofei , Zhang Man , Guo Yingying
Published: September 2020

Aiming at the problem of energy consumption and efficiency in the treatment process by the treatment device of drilling fluid wastewater, this paper puts out an adaptive fuzzy control method. The fuzzy controller is based on the real-time online monitoring data of water quality and make rules based on engineering practice experience. The adaptive algorithm based on the real time online data of Do, pH and SS can treat drilling fluid wastewater in pertinence by selecting the specific processing module from aeration, filter presses, de-oiled, activated carbon, and adjusting the temperature of the Mechanical Vapor Recompression (MVR) processor. The experimental results show that the method of fuzzy control can decrease energy cost and improve treatment efficiency. The device with the optimized control can save energy consumption per hour 0.6 kw.h, and save 1 hour in a single workflow.
Study on straightening quality control for slender rod based on digital twin
Authors: Chen Xinchun , Yan Naiqing , Wang Can , Ding Peng
Published: September 2020

For the technical problems of slender rod straightening quality control in the mechanical industry, a straightening quality control method for slender rod based on digital twin is proposed. According to the characteristics of the slender rod straightening process system, straightness detection device for slender rod suitable for production site is developed. Combined with the straightening process of the slender rod, straightening stroke model is given. Straightening quality control system for slender rod is established based on digital twin technology. Taking the piston rod of a large hydraulic cylinder as an example, straightening quality is controlled. The result shows that the theoretical calculation error rate of the straightening stroke is less than 0.5%. Straightness data of piston rod with quality control system is compared with straightness data of piston rod without quality control system. The result shows that the straightness consistency of the piston rod by quality control is good, and it is controlled within the range of 0-0.5mm. Straightening pass rate increased from 30% to 100%. This proves straightening quality control system for slender rod based on digital twin is effective. It can meet the needs of actual production. This study provides technical support for the optimization of slender rod straightening process parameters and high-precision machining.
A prediction method of residential load transformer demand factor based on time series
Authors: Sun Ming , Jiang Hang , Lu Yangchao , Liu Qing , Yang Yong , Yu Bing
Published: September 2020

The use of residential transformer in distribution network directly affects the assessment result of the feeder installed capacity. With the development of power system reform and the improvement of power supply economy, it is more and more important to evaluate the demand factor of these transformers scientifically. In this paper, a method based on time series is proposed to predict the demand factor of residential load transformer in distribution network. Firstly, the actual current data of distribution transformer is collected. After data pre-processing, the maximum value of monthly demand factor is calculated, and the historical data based on time series can be obtained. Then, the general development trend of demand factor is predicted through gray model. Finally, more accurate demand factor prediction value can be obtained by using neural network model training. The data of a distribution transformer in a capital city of China is selected to illustrate the practicability and effectiveness of the proposed algorithm. The proposed algorithm can fully consider the dynamic characteristics of the demand factor changing in time, and will greatly improve the accuracy of the feeders installed capacity assessment.
Defect detection for aluminium conductor composite core X-ray image with deep convolution network
Authors: Wei Rui , Wei Hanlai , Chen Dabing , Xie Lizhe , Wang Zheng , Hu Yining
Published: September 2020

The Aluminum Conductor Composite Core (ACCC) has been considered one of the solutions for massively increasing requirements for the electricity power transmission in China due to its superiority in weight, strength and ampacity. Yet the popularize of ACCC lines suffer from damages caused during the construction, which may result in line broke in the future. In this paper, an automatic defect detection method based on Deep Convolution Network is proposed. Image classification framework with Inception-Resnet structure as backbone is applied. With the online self-designed robot, the proposed method can effectively detect the defects such as fracture, splitting and distortion, with a recall rate over 90%.
Mix design and properties of reactive powder concrete with diatomaceous earth as cement replacement
Authors: Saidi T , Hasan M , Riski A D D , Ayunizar R R , Mubarak A
Published: September 2020

Reactive powder concrete (RPC) consuming a large amount of Portland cement results in high cost. To reduce the cement used in RPC, the silica fume and ground granulated blast-furnace slag have been used as cement replacement. However, those materials are not available in Aceh Province - Indonesia. The objective of this research is to propose the mix design of RPC composed of locally available materials. In this paper, the mix design of RPC using calcined diatomaceous earth powder as partial cement replacement is presented. The iron ore powder was used as filler, and river sand with a diameter of less than 1 mm was used as aggregate. To maintain the workability of concrete, superplasticizer was added. The bulk density, specific gravity as well as particle size distribution of Portland cement, diatomaceous earth powder, iron ore powder and river size were tested. The modified Andreasen and Andersen model was utilized. The mix proportion of materials was determined using an optimization algorithm based on the least-squares method. Furthermore, all materials were mixed to produce RPC; and then the properties of fresh and hardened concrete i.e. workability, air content, compressive strength, splitting tensile strength, and flexural strength, were tested. The relative slump flow decreases with the increase of diatomaceous earth binder. The RPC with diatomaceous earth powder has a lower 7 days compressive strength but high flexural strength and splitting tensile strength.
Large deformation of building frame structure due to December 7, 2016 Pidie Jaya earthquake
Authors: Hasan M , Afifuddin M , Putra R
Published: September 2020

Pidie Jaya earthquake on December 7, 2016 caused the damage of many buildings. This paper presents the case study on a building frame structure that has undergone large deformation during Pidie Jaya earthquake without structural damage. The building has 3 stories. The permanent lateral displacement and inter-story drift of the structure in Y direction at the third story after the earthquake is 420 mm and 4.2%, respectively, which exceed the requirement of Indonesian standard for design building and other structures under earthquake load (SNI 1726:2012). The building structure was modeled as a space frame. A response spectral analysis with design response spectral provided in SNI 1726:2012 was conducted. For comparison, a time history analysis based on real time ground acceleration during Pidie Jaya earthquake was also conducted. The maximum lateral displacement based on response spectral analysis is 469 mm with maximum inter-story drift of 4.79%. Based on time history analysis, the maximum lateral displacement and inter-story drifts are 550 mm and 5.81%, respectively. Based on those results, it is necessary to revise the design response spectrum in SNI 1726:2012.
Community satisfaction levels on the housing reconstruction project after Mentawai tsunami in 2010 - a case study at Sipora Island
Authors: Ophiyandri T , Hidayat B , Ghiffari C
Published: September 2020

An earthquake accompanied by tsunami that occurred in the Mentawai Islands on 25 October 2010 brought many casualties and damage on housing. As a result, people living on the coastline lost their homes and has to be relocated to safer places. The implementation of the housing reconstruction program was based on the relocation approach. Unsafe coastal locations require the communities to move to higher ground which unfortunately at the forest areas of Mentawai. The success of the reconstruction of the housing sector can be an indicator of success in the implementation of post-disaster reconstruction. The purpose of this research is to identify the community satisfaction levels on the housing reconstruction projects in Sipora island. This research was conducted in South Sipora by conducting structured interview on 20 respondents spread across four villages. Respondents were invited to rate the satisfaction levels from very dissatisfied until very satisfied with points values 1-5. The results show that the level of community satisfaction was 2.91. The main problem was caused by a long delay in the start of the reconstruction program. In addition, there are still problems after the house is completed, such as the lack of availability of clean water and public facilities.
Seismic performance analysis of multi-span masonry infilled RC frame based on analytical strut model
Authors: Maidiawati M , Tanjung J , Nugroho F , Hayati Y
Published: September 2020

According to previous studies, it was accepted that masonry infills have a contribution to lateral strength, stiffness, and ductility of reinforced concrete (RC) frames structures. In the past studies, an analytical method of diagonal strut model has developed for evaluating the seismic performance of masonry infill. In this model, the masonry infills were presented by compression struts as distributed forces at the frame-infill interfaces in which the frame-infill contact lengths were evaluated by static equilibrium related to compression balance and lateral displacement compatibility. The lateral strength of infill was determined based on frame-infill contact length. In the current study, an experimental study of quasi-static cyclic lateral loading tests was conducted to evaluate the seismic performance of two-bay brick masonry infilled RC frames. This paper discusses the results of seismic performance brick infills based on experimental and analysis results of the multi-span masonry RC frame applying the diagonal strut model. According to the analytical model, antisymmetric strut was acted at the top and bottom of the middle column of the multi-span infilled frame from each infill. As a result, good agreements of lateral strength of structures were obtained between the experimental and analytical values.
Public perception of the transit bus plan in the city of Lhokseumawe
Authors: Haryadi H , Darma Y , Isya M
Published: September 2020

Community dependence on private transportation is a major factor in traffic congestion. Community perception is one of many important aspects in policy-making because by involving the community, the decision-makers will be able to capture the views, needs, and expectations of the community. The purpose of this study is to examine people’s perceptions of the transit bus plan. The data collection method used is Stated Preference (SP) with a total of 100 respondents in stratified random sampling. The SP questionnaire contains information about socio-economic status and respondents’ perceptions. The results of the perception survey show that the overall psychological questions have values above 2.5 from the 4 scale Likert, which means that respondents’ perceptions of the transit bus plan are very positive. The respondents agree that the transit bus can be received with positive values.
Mechanical properties improvement of clay soils using dry dust collector and silica sand wastes
Authors: Gunarti A S S , Nuryati S , Primatama F , Raharja I
Published: September 2020

Wastes from industrial parks increase rapidly; they are also difficult to manage. They should be carefully managed and used for other purposes, e.g., improving the infrastructure. The study did some laboratory experiments, e.g., California bearing ratio test, direct shear test, and triaxial (unconsolidated and undrained condition) test. Soil stabilization through chemical addition was done by mixing the original soil with some compositions of dry dust collector and silica sand wastes. California bearing ratio value of the 5mm penetration of soil with an additive composition of 7.5% silica sand and 1.5% dry dust collector was increased by 86 %. Internal friction angle value based on triaxial test showed that soil with an additive composition of 7.5 % silica sand (without dry dust collector) was increased by 2.5 %. The cohesion of soil having the additive composition of 7.5 % silica sand and 1.5 % dry dust collector increased by 60 % from the original soils.
The effect of water cement ratio (WCR) on compressive strength of interlocking bricks with mix design variations
Authors: Malahayati N , Hayati Y , Mahlil  , Sundary D , Maulina F
Published: September 2020

Interlocking brick is a material used for wall work in home construction. Called Interlocking Brick or Brick Interlock because the method of arranging the bricks is interlocked with one another. This interlocking brick itself began to be known in Aceh Province after the 2004 tsunami disaster. Interlocking brick is a block of compacted soil, made of cement, silt soil, and dried sand, measuring 300 χ 150 χ 100 cm3. Interlocking brick can function as a wall that can withstand structural and non-structural components. The purpose of this research is to get the compressive strength value of interlocking bricks designed with variations in the water cement ratio (WCR) so that the optimum compressive strength of interlocking bricks is obtained. The WCR used was 0.3; 0.4; and 0.5, while for the composition of cement, silt, and sand the ratio of 1:2:2 is used. The making of test specimens for testing the compressive strength of interlocking bricks is by cutting the interlocking bricks into cubes measuring 50 χ 50 χ 50 mm by 5 specimens for each variation so that the total of the total specimens are 45 specimens. Testing is done at the age of 7, 14, and 28 days. The results of the compressive strength of interlocking bricks using WCR 0.3 average compressive strength at the age of 7 days reached 8.10 MPa, 14 days reached 9.49 MPa and 28 days reached 10.94 MPa. For WCR 0.4, compressive strength on average at 7 days reaches 5.69 MPa, 14 days reaches 7.61 MPa and 28 days reaches 9.77 MPa. And for WCR 0.5 the average compressive strength at the age of 7 days reaches 5.36 MPa, 14 days reaches 8.25 MPa and 28 days reaches 9.93 MPa. From the compressive strength test results the interlocking brick with a WCR variation of 0.3; 0.4; and 0.5 with a mixture of 1:2:2 can be used as wall work material in house construction for structural construction and the optimum compressive strength value is obtained at WCR 0.3.
The effect of diameter and distance between vegetation in the riverbank to flood discharge by Eco-hydraulic in the Lawe Alas River, Southeast Aceh, Indonesia
Authors: Ziana  , Rizalihadi M , Azmeri  , Nugraha A
Published: September 2020

One of the eco-hydraulic methods used to reduce flooding and erosion in rivers is by vegetation along the riverbanks. The main problem in the Lawe Alas River is repeated flooding in the downstream areas that need to be addressed upstream. The purpose of this study is to design the proper vegetation diameter and the distance between plants that can reduce the velocity and flow of the river. The method of study in this research consists of conducting field surveys, measuring river discharge, and calculating vegetation diameter on riverbanks to reduce velocity and discharge based on the equation proposed by Merten. The planned diameter of vegetation with diameter is 0,1 m - 1,1 m, and the distance between vegetation 1 m - 11 m. The results showed that the maximum discharge capacity of the Lawe Alas River was 514,360 m3/s. For the return period of 50 years, 50 m from the riverbank design, vegetation with a diameter of 10 cm to 110 cm can reduce flooding in the resulting discharge 222,95 m3/s - 241,68 m3/s. Discharge is greater than 50 yearly flood discharge, which is 528,670 m3/s. In conditions without vegetation (diameter = 0) velocity = 1,725 m/s, the velocity produced by the design is 0,727 m/s - 0,789 m/s. Discharge and velocity are reduced by 54% - 58% so that the vegetation diameter of 10 cm is suitable for environmentally friendly designs on the riverbanks 50 m. In conclusion, all planned vegetation diameters can reduce discharge and velocity. Recommended vegetation is local vegetation, which is a tree that produces fruit that can be benefited to the community so that it can be planted and managed by local residents.
Study on the impact of canal blocking on groundwater fluctuation for tropical peatland restoration
Authors: Sutikno S , Rinaldi R , Putri R A , Khotimah G K
Published: September 2020

Peatland fires occur almost every year in Indonesia that might be caused by over-drained peatland due to canalization for a certain purpose. Canalization in the peatland leads to a significant decreasing change of groundwater level that might cause peatland very vulnerable against fire. The rewetting approach by the Peatland Restorations Agency of Indonesia using canal blocking is expected to keep groundwater level high so that the peatland is maintained in an always wet condition. Therefore, it is important to study the impact of canal blocking on the fluctuation of groundwater level in peatland ecosystems. This study was carried out at a research site which is located in Pulau Tebing Tinggi peatland hydrological unit, Kepulauan Meranti Regency, Riau, Indonesia. Groundwater level fluctuation as the impact of canal blocking was monitored using eight dipwells that were set with a distance of 1 m, 51 m, 101 m, and 201 m from the canal for each transect of the three transects. The result of this study showed that the canal blocking has a good impact for keeping groundwater level and keeping peatland on an always wet condition for peatland restoration and peat fire prevention until 400 m distance to the upstream area from canal block and about 1 m distance perpendicular to the canal. The canal blockings will have a good impact on rewetting at the peatland area up to 201 m distance perpendicular to the canal if the rise of water level at the canal is more than 0.6 m for peatland restoration.
Entropic and heat-transfer analysis of EMHD flows with temperature-dependent properties
Authors: Mondal A , Mandal P K , Weigand B , Nayak A K
Published: September 2020

This paper focusses on a theoretical analysis of the entropic generation and heat-transfer characteristics of electromagnetohydrodynamic (EMHD) flow in vertical hydrophobic microchannels. The flow viscosity, electrical conductivity, and thermal conductivity are assumed to be temperature variant. The fluid velocity and energy transfer equations associated with a system of coupled non-linear equations dealing with hydrophobic slip conditions are solved using a finite volume method associated with lubrication theory. The Debye–Hückel approximation is employed in an electrical double layer combined with the Poisson–Boltzmann equation to acquire an analytical solution for the electrical potential function. Slip velocities along with constant temperatures are provided to obtain numerical solutions for the case of a fully developed EMHD flow, in order to reveal the influence of fluid rheology. The results are presented for electromagnetic transport with variable viscosity over hydrophobic interfaces. Numerical and analytical validations are performed using the existing experimental results. In this study, we vizualize the significance of variable viscosity, electrical conductivity, and thermal conductivity on temperature distributions in the presence of a magnetic field. In this work, entropy generation is represented in terms of the Bejan number, which greatly impacts the normalized electroosmotic flow as well as the thermophysical parameters, leading to a minimization of the entropy-generation rate.
Qubit coupled cluster singles and doubles variational quantum eigensolver ansatz for electronic structure calculations
Authors: Xia Rongxin , Kais Sabre
Published: September 2020

Variational quantum eigensolver (VQE) for electronic structure calculations is believed to be one major potential application of near term quantum computing. Among all proposed VQE algorithms, the unitary coupled cluster singles and doubles excitations (UCCSD) VQE ansatz has achieved high accuracy and received a lot of research interest. However, the UCCSD VQE based on fermionic excitations needs extra terms for the parity when using Jordan–Wigner transformation. Here we introduce a new VQE ansatz based on the particle preserving exchange gate to achieve qubit excitations. The proposed VQE ansatz has gate complexity up-bounded to O(n
4) for all-to-all connectivity where n is the number of qubits of the Hamiltonian. Numerical results of simple molecular systems such as BeH2, H2O, N2, H4 and H6 using the proposed VQE ansatz gives very accurate results within errors about 10−3 Hartree.
Renal Sodium Handling in Relation to Environmental and Genetic Factors in Untreated Chinese
Authors: Kang Yuan-Yuan , Cheng Yi-Bang , Guo Qian-Hui , Sheng Chang-Sheng , Huang Qi-Fang , Xu Ting-Yan , Li Yan , Wang Ji-Guang
Published: September 2020

BACKGROUND

We investigated proximal and distal renal tubular sodium handling, as assessed by fractional excretion of lithium (FELi) and fractional distal reabsorption rate of sodium (FDRNa), in relation to environmental and genetic factors in untreated patients.

METHODS

Our study participants were suspected hypertensive patients being off antihypertensive medication for ≥2 weeks and referred for 24-hour ambulatory blood pressure monitoring. We collected serum and 24-hour urine for measurement of sodium, creatinine, and lithium concentration, and calculated FELi and FDRNa. We genotyped 19 single-nucleotide polymorphisms associated with renal sodium handling or blood pressure using the ABI SNapShot method.

RESULTS

The 1,409 participants (664 men, 47.1%) had a mean (±SD) age of 51.0 ± 10.5 years. After adjustment for host factors, both FELi and FDRNa were significantly (P ≤ 0.01) associated with season and humidity, explaining ~1.3% and ~3.5% of the variance, respectively. FELi was highest in autumn and lowest in summer and intermediate in spring and winter (P = 0.007). FDRNa was also highest in autumn but lowest in winter and intermediate in spring and summer (P < 0.001). Neither FELi nor FDRNa was associated with outdoor temperature or atmospheric pressure (P ≥ 0.13). After adjustment for host and environmental factors and Bonferroni multiple testing, among the 19 studied genetic variants, only rs12513375 was significantly associated with FELi and FDRNa (P ≤ 0.004) and explained about 1.7% of the variance.

CONCLUSIONS

Renal sodium handling as measured by endogenous lithium clearance was sensitive to major environmental and genetic factors. Our finding is toward the use of these indexes for the definition of renal tubular dysfunction.
Examining the Prospective Associations Between Mindfulness Facets and Substance Use in Emerging Adulthood
Authors: Single Alanna , Keough Matthew T
Published: September 2020

Aims

Emerging adulthood (i.e. ages 18–25) is a developmental phase associated with frequent alcohol and cannabis use, placing this population at risk for substance use problems. Depression and anxiety (i.e. emotional psychopathology) are also prevalent during this phase, and some emerging adults use substances to cope with these negative emotions. Mindfulness—a multifaceted construct—involves being present in a nonjudgmental and nonreactive way. Certain mindfulness facets are particularly relevant in buffering against substance use. A recent longitudinal study [Single A, Bilevicius E, Johnson EA. et al. (2019) Specific facets of trait mindfulness reduce risk for alcohol and drug use among first-year undergraduate students. Mindfulness  10:1269–1279] showed that specific mindfulness facets (i.e. acting with awareness, nonjudging of inner experience and nonreactivity to inner experience) predicted decreased alcohol and drug use in undergraduates. These pathways were explained by low levels of emotional psychopathology.

Methods

This study expanded this recent work by using a three time-point longitudinal design and by including measures of both alcohol and cannabis use and related problems. Using MTurk, participants (N = 299) completed online measures of trait mindfulness, depression, anxiety, alcohol and cannabis use and related problems at three time-points, each 2 weeks apart. Structural equation modeling was used to test the hypotheses.

Results

The acting with awareness and nonjudging of inner experience facets predicted fewer alcohol problems, but not alcohol use, and this effect was mediated by low levels of emotional psychopathology. These results were not supported for cannabis use and problems.

Conclusion

This study demonstrates that there may be differences in the pathways from trait mindfulness to alcohol and cannabis use during emerging adulthood.
Branding the Geospatial Industry
Authors: Imaoka Laura Beltz
Published: September 2020

This study situates geospatial technology within the platform economy and constructs its brand culture, making it visible as a for-profit business rather than a utility. A critical lens is turned on the macroscopic economic and micro-social processes of the geospatial industry that result in the hegemonic relations and discursive regimes that legitimize and naturalize a common geospatially equipped, data-driven world. The annual user conventions and platform marketing of Esri, the global market leader in geographical information systems (GIS), acts as a site to observe how an imagined geospatial community of practitioners and investors is constructed. Branded content is unpacked to understand how the company’s image-making cultivates power relations between the public at large while negating itself as gatekeeper. These symbolic processes and collective practices help influence the uncritical investment and growth of the geospatial industry.
The American Board of Internal Medicine’s New Longitudinal Assessment Option and What It Means for Infectious Disease Specialists
Authors: Abraham George M , Saravolatz Louis D
Published: September 2020

As members of the American Board of Internal Medicine’s (ABIM) Infectious Disease (ID) Board we’ve heard from many of our colleagues asking for greater flexibility in maintaining their ABIM Board Certification. The ID Board—and ABIM as a whole—has engaged with the physician community over the past several years to gain a deeper understanding of what is most important to them, and how an enhanced Maintenance of Certification (MOC) program could support their commitment to keeping up with advances in medical knowledge. This article serves as an update about how ABIM has evolved its assessments over time and on our progress in developing a new longitudinal pathway that is anticipated to become available in most specialties in 2022, and will launch in ID in 2023.
Model averaging estimation for high-dimensional covariance matrices with a network structure
Authors: Zhu Rong , Zhang Xinyu , Ma Yanyuan , Zou Guohua
Published: September 2020

In this paper, we develop a model averaging method to estimate a high-dimensional covariance matrix, where the candidate models are constructed by different orders of polynomial functions. We propose a Mallows-type model averaging criterion and select the weights by minimizing this criterion, which is an unbiased estimator of the expected in-sample squared error plus a constant. Then, we prove the asymptotic optimality of the resulting model average covariance estimators. Finally, we conduct numerical simulations and a case study on Chinese airport network structure data to demonstrate the usefulness of the proposed approaches.
Stress CMR in patients with obesity: insights from the Stress CMR Perfusion Imaging in the United States (SPINS) registry
Authors: Ge Yin , Steel Kevin , Antiochos Panagiotis , Bingham Scott , Abdullah Shuaib , Mikolich J Ronald , Arai Andrew E , Bandettini W Patricia , Shanbhag Sujata M , Patel Amit R , Farzaneh-Far Afshin , Heitner John F , Shenoy Chetan , Leung Steve W , Gonzalez Jorge A , Shah Dipan J , Raman Subha V , Nawaz Haseeb , Ferrari Victor A , Schulz-Menger Jeanette , Stuber Matthias , Simonetti Orlando P , Kwong Raymond Y
Published: September 2020

Aims

Non-invasive assessment and risk stratification of coronary artery disease in patients with large body habitus is challenging. We aim to examine whether body mass index (BMI) modifies the prognostic value and diagnostic utility of stress cardiac magnetic resonance imaging (CMR) in a multicentre registry.

Methods and results

The SPINS Registry enrolled consecutive intermediate-risk patients who presented with a clinical indication for stress CMR in the USA between 2008 and 2013. Baseline demographic data including BMI, CMR indices, and ratings of study quality were collected. Primary outcome was defined by a composite of cardiovascular death and non-fatal myocardial infarction. Of the 2345 patients with available BMI included in the SPINS cohort, 1177 (50%) met criteria for obesity (BMI ≥ 30) with 531 (23%) at or above Class 2 obesity (BMI ≥ 35). In all BMI categories, >95% of studies were of diagnostic quality for cine, perfusion, and late gadolinium enhancement (LGE) sequences. At a median follow-up of 5.4 years, those without ischaemia and LGE experienced a low annual rate of hard events (<1%), across all BMI strata. In patients with obesity, both ischaemia [hazard ratio (HR): 2.14; 95% confidence interval (CI): 1.30–3.50; P = 0.003] and LGE (HR: 3.09; 95% CI: 1.83–5.22; P < 0.001) maintained strong adjusted association with the primary outcome in a multivariable Cox regression model. Downstream referral rates to coronary angiography, revascularization, and cost of care spent on ischaemia testing did not significantly differ within the BMI categories.

Conclusion

In this large multicentre registry, elevated BMI did not negatively impact the diagnostic quality and the effectiveness of risk stratification of patients referred for stress CMR.
Meta-Analysis of Present-Bias Estimation using Convex Time Budgets
Authors: Imai Taisuke , Rutter Tom A , Camerer Colin F
Published: September 2020

We examine 220 estimates of the present-bias parameter from 28 articles using the Convex Time Budget protocol. The literature shows that people are on average present-biased, but estimates exhibit substantial heterogeneity across studies. There is evidence of modest selective reporting in the direction of over-reporting present bias. The primary source of heterogeneity is the type of reward, either monetary or non-monetary, but this effect is weakened after correcting for selective reporting. In studies using monetary rewards, the delay until the issue of the reward associated with the ‘current’ time period influences estimates of the present-bias parameter.
A converging subset of soil bacterial taxa is permissive to the IncP-1 plasmid pKJK5 across a range of soil copper contamination
Authors: Song Jianxiao , Klümper Uli , Riber Leise , Dechesne Arnaud , Smets Barth F , Sørensen Søren J , Brandt Kristian K
Published: September 2020

Stressors like metals or antibiotics can affect bacterial community permissiveness for plasmid uptake, but there is little knowledge about long-term effects of such stressors on the evolution of community permissiveness. We assessed the effect of more than 90 years of soil Cu contamination on bacterial community permissiveness (i.e. uptake ability) toward a gfp-tagged IncP-1 plasmid (pKJK5) introduced via an Escherichia coli donor. Plasmid transfer events from the donor to the recipient soil bacterial community were quantified and transconjugants were subsequently isolated by fluorescence activated cell sorting and identified by 16S rRNA gene amplicon sequencing. Transfer frequency of plasmid pKJK5 was reduced in bacterial communities extracted from highly Cu contaminated (4526 mg kg−1) soil compared to corresponding communities extracted from moderately (458 mg kg−1) Cu contaminated soil and a low Cu reference soil (15 mg kg−1). The taxonomic composition of the transconjugal pools showed remarkable similarities irrespective of the degree of soil Cu contamination and despite contrasting compositions of the extracted recipient communities and the original soil communities. Permissiveness assessed at the level of individual operational taxonomic units (OTUs; 16S rRNA gene 97% sequence similarity threshold) was only slightly affected by soil Cu level and high replicate variability of OTU-level permissiveness indicated a role of stochastic events in IncP-1 plasmid transfer or strain-to-strain permissiveness variability.
Assessment of phage-mediated inhibition of Salmonella Typhimurium treated with sublethal concentrations of ceftriaxone and ciprofloxacin
Authors: Jeon Gibeom , Ahn Juhee
Published: September 2020

This study was designed to evaluate the synergistic effect of phage (P22) and antibiotic on the inhibition of Salmonella Typhimurium exposed to ceftriaxone (CEF) and ciprofloxacin (CIP). The effect of phage and antibiotic treatments was evaluated by plaque size, disk diffusion, antibiotic susceptibility and phage multiplication assays. The sequential treatment effect of phage and antibiotic was carried out in different treatment order and time for 12 h at 37°C. P22 plaque sizes were increased by 28 and 71%, respectively, in the presence of CEF and CIP. The clear zone sizes in disk diffusion assay were significantly increased to >37 mm in the presence of CEF and CIP compared to the control (28–31 mm). Pre-treatment with P22 enhanced the antimicrobial effect of CIP, showing >2 log reduction after a 12 h incubation. Phage P22 combined with antibiotics (CEF and CIP) effectively inhibited the growth of S. Typhimurium depending on the treatment order and time. These results provide useful information for understanding the synergistic effect of phage and antibiotic treatment which can be an effective option to control antibiotic resistant pathogens.
Undetectable viral RNA in oocytes from SARS-CoV-2 positive women
Authors: Barragan M , Guillén J J , Martin-Palomino N , Rodriguez A , Vassena R
Published: September 2020

A central concern for the safe provision of ART during the current coronavirus disease 2019 (COVID-19) pandemic is the possibility of vertical transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection through gametes and preimplantation embryos. Unfortunately, data on SARS-CoV-2 viral presence in oocytes of infected individuals are not available to date. We describe the case of two women who underwent controlled ovarian stimulation and tested positive to SARS-CoV-2 infection by PCR on the day of oocyte collection. The viral RNA for gene N was undetectable in all the oocytes analyzed from the two women.
Physiological responses to temperature and ocean acidification in tropical fleshy macroalgae with varying affinities for inorganic carbon
Authors: Ho Maureen , McBroom James , Bergstrom Ellie , Diaz-Pulido Guillermo
Published: September 2020

Marine macroalgae have variable carbon-uptake strategies that complicate predicting responses to environmental changes. In seawater, dissolved inorganic carbon availability can affect the underlying physiological mechanisms influencing carbon uptake. We tested the interactive effects of ocean acidification (OA) and warming on two HCO3−-users (Lobophora sp. and Amansia rhodantha), a predominately CO2-user (Avrainvillea nigricans), and a sole CO2-user (Plocamium hamatum) in the Great Barrier Reef, Australia. We examined metabolic rates, growth, and carbon isotope values (δ13C) in algae at 26, 28, or 30°C under ambient or elevated pCO2 (∼1000 µatm). Under OA, δ13C values for the HCO3−-users decreased, indicating less reliance on HCO3−, while δ13C values for CO2-users were unaffected. Both HCO3−-users decreased in growth across temperatures under ambient pCO2, but this negative effect was alleviated by OA at 30°C. A. nigricans lost biomass across all treatments and P. hamatum was most sensitive, with reduced survival in all physiological responses. Metabolic rates varied greatly to interacting temperature and OA and indicated a decoupling between the relationship of photosynthesis and growth. Furthermore, our findings suggest HCO3−-users are more responsive to future CO2 changes, and highlight examining carbon physiology to infer potential responses to interacting environmental stressors.
Sacred Time and Rabbinic Literature: New Directions for an Old Question
Authors: Kaye Lynn
Published: September 2020

This article questions the utility of the term “sacred time.” In other words, it cautions against allowing sacred time to obscure how scholars study the dynamic relations between temporalities and sanctity in classical rabbinic texts (c. 200–550 CE). The achievement of recent Biblical and Jewish studies scholars who rejected characterizations of Hebrew or Jewish time as monolithic was their decoupling of the patterning or shape of events from what it means for time to be holy or for there to be a time for holiness. In the wake of such corrective efforts, scholars can now examine how rabbinic texts engage the quality of holiness as it pertains to durations, human activities, embodied temporal awareness, the time of exegesis, or to God’s time. This article distinguishes God’s time and human moments of recurrence and connection from eternity and sacred time through analysis of late antique Palestinian midrashim and presents directions for future study of holiness and time in classical rabbinic literature.
Predictive article recommendation using natural language processing and machine learning to support evidence updates in domain-specific knowledge graphs
Authors: Sharma Bhuvan , Willis Van C , Huettner Claudia S , Beaty Kirk , Snowdon Jane L , Xue Shang , South Brett R , Jackson Gretchen P , Weeraratne Dilhan , Michelini Vanessa
Published: September 2020

Objectives

Describe an augmented intelligence approach to facilitate the update of evidence for associations in knowledge graphs.

Methods

New publications are filtered through multiple machine learning study classifiers, and filtered publications are combined with articles already included as evidence in the knowledge graph. The corpus is then subjected to named entity recognition, semantic dictionary mapping, term vector space modeling, pairwise similarity, and focal entity match to identify highly related publications. Subject matter experts review recommended articles to assess inclusion in the knowledge graph; discrepancies are resolved by consensus.

Results

Study classifiers achieved F-scores from 0.88 to 0.94, and similarity thresholds for each study type were determined by experimentation. Our approach reduces human literature review load by 99%, and over the past 12 months, 41% of recommendations were accepted to update the knowledge graph.

Conclusion

Integrated search and recommendation exploiting current evidence in a knowledge graph is useful for reducing human cognition load.
A novel isoform of ATOH8 promotes the metastasis of breast cancer by regulating RhoC
Authors: Xu Mengyao , Huang Shan , Dong Xiaoli , Chen Yanan , Li Miao , Shi Wen , Wang Guanwen , Huang Chongbiao , Wang Qiong , Liu Yanhua , Sun Peiqing , Yang Shuang , Xiang Rong , Chang Antao
Published: September 2020

Metastases are the main cause of cancer-related mortality in breast cancer. Although significant progress has been made in the field of tumor metastasis, the exact molecular mechanisms involved in tumor metastasis are still unclear. Here, we report that ATOH8-V1, a novel isoform of ATOH8, is highly expressed in breast cancer and is a negative prognostic indicator of survival for patients. Forced expression of ATOH8-V1 dramatically enhances, while silencing of ATOH8-V1 decreases the metastasis of breast cancer cell lines. Moreover, ATOH8-V1 directly binds to the RhoC promoter and stimulates the expression of RhoC, which in turn enhances the metastasis of breast cancer. Altogether, our data demonstrate that ATOH8-V1 is a novel pro-metastatic factor that enhances cancer metastasis, suggesting that ATOH8-V1 is a potential therapeutic target for treatment of metastatic cancers.
Detection of Dermacentor andersoni (Acari: Ixodidae) in Brazil on a Human Traveler Returning from the United States
Authors: Faccini-Martínez Álvaro A , Martins Thiago F , Silveira Iara , Labruna Marcelo B
Published: September 2020

Only one previous record of an exotic tick on a Brazilian traveler has been reported. Here, we report the detection of Dermacentor andersoni (Stiles) in Brazil while attached to a human traveler returning from the United States. This report is the fifth record of D. andersoni as an exotic tick, and the second record of an exotic tick on a South American traveler.
Management of a life-threatening intercostal artery bleeding, difficult to visualize in open surgery: a case report
Authors: Laugsand Eivor Alette , Xanthoulis Athanasios
Published: September 2020

Life-threatening bleeding from an intercostal artery is a rare and challenging event. A 74-year-old patient with a right-sided pleural effusion was treated by a pigtail pleural drain. He developed a large haemothorax, initially addressed by a large bore chest tube. As he became haemodynamically unstable, he required an emergency anterolateral right thoracotomy. It was difficult to visualize and reach the bleeding vessel during open surgery. A 30° laparoscopy camera was introduced and the bleeding site was identified. An incision was made directly over the bleeding site and the two ends of the lacerated intercostal artery were ligated by two externally placed figure-of-eight sutures. The patient survived and recovered fully. As most general surgeons, even at smaller hospitals, are familiar with laparoscopy, the technique described here may be useful for other surgeons to employ if a life-threatening intercostal artery injury occurs.
Conventional therapy and new antifungal drugs againstMalasseziainfections
Authors: Rhimi Wafa , Theelen Bart , Boekhout Teun , Aneke Chioma Inyang , Otranto Domenico , Cafarchia Claudia
Published: September 2020

Malassezia yeasts are commensal microorganisms occurring on the skin of humans and animals causing dermatological disorders or systemic infections in severely immunocompromised hosts. Despite attempts to control such yeast infections with topical and systemic antifungals, recurrence of clinical signs of skin infections as well as treatment failure in preventing or treating Malassezia furfur fungemia have been reported most likely due to wrong management of these infections (e.g., due to early termination of treatment) or due to the occurrence of resistant phenomena. Standardized methods for in vitro antifungal susceptibility tests of these yeasts are still lacking, thus resulting in variable susceptibility profiles to azoles among Malassezia spp. and a lack of clinical breakpoints. The inherent limitations to the current pharmacological treatments for Malassezia infections both in humans and animals, stimulated the interest of the scientific community to discover new, effective antifungal drugs or substances to treat these infections. In this review, data about the in vivo and in vitro antifungal activity of the most commonly employed drugs (i.e., azoles, polyenes, allylamines, and echinocandins) against Malassezia yeasts, with a focus on human bloodstream infections, are summarized and their clinical implications are discussed. In addition, the usefulness of alternative compounds is discussed.