bluuebunny/crossref_metadata_2025 huggingface dataset:
Glacier ice archives nearly 15,000-year-old microbes and phages
Authors: Zhong Zhi-Ping , Tian Funing , Roux Simon , Gazitúa M. Consuelo , Solonenko Natalie E. , Li Yueh-Fen , Davis Mary E. , Van Etten James L. , Mosley-Thompson Ellen , Rich Virginia I. , Sullivan Matthew B. , Thompson Lonnie G.
Published: July 2021

Background

Glacier ice archives information, including microbiology, that helps reveal paleoclimate histories and predict future climate change. Though glacier-ice microbes are studied using culture or amplicon approaches, more challenging metagenomic approaches, which provide access to functional, genome-resolved information and viruses, are under-utilized, partly due to low biomass and potential contamination.

Results

We expand existing clean sampling procedures using controlled artificial ice-core experiments and adapted previously established low-biomass metagenomic approaches to study glacier-ice viruses. Controlled sampling experiments drastically reduced mock contaminants including bacteria, viruses, and free DNA to background levels. Amplicon sequencing from eight depths of two Tibetan Plateau ice cores revealed common glacier-ice lineages including Janthinobacterium, Polaromonas, Herminiimonas, Flavobacterium, Sphingomonas, and Methylobacterium as the dominant genera, while microbial communities were significantly different between two ice cores, associating with different climate conditions during deposition. Separately, ~355- and ~14,400-year-old ice were subject to viral enrichment and low-input quantitative sequencing, yielding genomic sequences for 33 vOTUs. These were virtually all unique to this study, representing 28 novel genera and not a single species shared with 225 environmentally diverse viromes. Further, 42.4% of the vOTUs were identifiable temperate, which is significantly higher than that in gut, soil, and marine viromes, and indicates that temperate phages are possibly favored in glacier-ice environments before being frozen. In silico host predictions linked 18 vOTUs to co-occurring abundant bacteria (Methylobacterium, Sphingomonas, and Janthinobacterium), indicating that these phages infected ice-abundant bacterial groups before being archived. Functional genome annotation revealed four virus-encoded auxiliary metabolic genes, particularly two motility genes suggest viruses potentially facilitate nutrient acquisition for their hosts. Finally, given their possible importance to methane cycling in ice, we focused on Methylobacterium viruses by contextualizing our ice-observed viruses against 123 viromes and prophages extracted from 131 Methylobacterium genomes, revealing that the archived viruses might originate from soil or plants.

Conclusions

Together, these efforts further microbial and viral sampling procedures for glacier ice and provide a first window into viral communities and functions in ancient glacier environments. Such methods and datasets can potentially enable researchers to contextualize new discoveries and begin to incorporate glacier-ice microbes and their viruses relative to past and present climate change in geographically diverse regions globally.
Joint development of cultural heritage protection and tourism: the case of Mount Lushan cultural landscape heritage site
Authors: Cai Zhenrao , Fang Chaoyang , Zhang Qian , Chen Fulong
Published: July 2021

The joint development of cultural heritage protection and tourism is an essential part of sustainable heritage tourism. Mount Lushan in China is such a site which in the past has had shortcomings in heritage protection and heritage tourism marketing. The present research addresses this issue by using digital technologies such as oblique aerial photography, 3D laser scanning technology, and 360 degrees panorama technology to digitize the Mount Lushan cultural landscape heritage site, integrating all elements to create a virtual tourism subsystem. It provides users with a virtual experience of cultural landscape heritage tourism and promotes cultural landscape tourism marketing. In addition, tourist flow and environmental subsystems were built through the integration of Internet of Things (IoT) technology and analytical models. The tourist flow subsystem can help managers to regulate tourist flow according to the tourist carrying capacity threshold. Managers can also conduct environmental health assessment and management through the "pressure-state-response" model provided by the environmental subsystem. Finally, a comprehensive platform was developed based on the system concept, which integrated the three subsystems and their functions, and developed different versions to provide a visual platform for tourists and managers. This study provides a new model for the joint development of cultural heritage protection and tourism activities.
Effects of yellow natural dyes on handmade Daqian paper
Authors: Luo Yanbing , Zhang Xiujuan
Published: July 2021

Natural yellow plant dyes and traditional medicines were used widely on historical papers in ancient China for religious reasons and conservation considerations. This study aims to evaluate some traditional yellow botanical sources of dyes that contain different chemical colorant compositions in order to understand their effects on the properties of traditional handmade paper. The physical and chemical changes in paper specimens treated with plant dyes were studied by examining properties such as the color, pH, thermogravimetric (TG) characteristics, tensile strength, folding endurance and microstructure by scanning electron microscopy (SEM). The results indicated that different colorants had different toning effects and that the main components, including carboxyl and ketone groups, could affect the paper stability at high temperatures. The results also revealed that the mechanical properties of paper specimens were improved after treatment with plant dyes. The significant improvements in the tensile strength and folding endurance and the slightly higher decomposition temperature of Amur cork tree-dyed paper could be ascribed to the strong interaction between the colorants’ main components and the fibers. The scientific evaluation of the property changes is therefore valuable information for weighing the advantages and disadvantages of the various yellow toning materials for paper conservation treatment.
Time series modeling of road traffic accidents in Amhara Region
Authors: Getahun Kidane Alemtsega
Published: July 2021

Road traffic accidents (RTA) are commonly encountered incidents that can cause injuries, death, and property damage to members of society. Ethiopia is one of the highest incident rates of road traffic accidents. Report of Transport and Communication from 2012 to 2014, shows an increment in the number of traffic accidents in Ethiopia. Amhara region accounted for 27.3% of the total road traffic accident-related deaths in Ethiopia during the year 2008/9, which is the highest share among all regions in Ethiopia. The current research aims to model the trend of injury, fatal and total road traffic accidents in the Amhara region from September 2013 to May 2017. Monthly reported traffic accidents were obtained from the traffic department of the Amhara region police commission. The most universal class of models for forecasting time series data called Auto-regressive Integrated Moving Averages (ARIMA) models were applied to model the trends and patterns of road traffic accident cases in the Amhara region. The average number of observed injury RTA, fatal RTA, and total RTA were 27.2, 14, and 78.2 per month respectively. It was observed that a relatively large number of RTA’s are reported on Tuesday, Thursday, and Saturday relative to other days of the week. The data also reveals that more than 60% of accidents involve drivers between the ages of 18–30 years. ARIMA (2,0,0) (1,0,0) ARIMA (2,0,0) and ARIMA (2,0,0) (1,1,0) were fitted as the best model for total injury accidents, fatal RTA and total RTA data respectively. A 48 months forecast was made based on the fitted models and it can be concluded that road traffic accident cases would continue at the non-decreasing rate in the Amhara region for the predicted periods. Therefore, the findings of this study draw attention to the importance of implementing improved better policies and close monitoring of road trafficking to change the existing non-decreasing trend of road traffic accidents in the region.
Trends in shaken baby syndrome diagnosis codes among young children hospitalized for abuse
Authors: Conrad Aislinn , Butcher Brandon , Oral Resmiye , Ronnenberg Megan , Peek-Asa Corinne
Published: July 2021

Objective

To investigate national trends of SBS diagnosis codes and how trends varied among patient and hospital characteristics.

Methods

We examined possible SBS, confirmed SBS, and non-SBS abuse diagnosis codes among children age three and younger who were hospitalized for abuse between 1998 and 2014 using a secondary analysis of the National Inpatient Sample, the largest US all-payer inpatient care database (N = 66,854). A baseline category logit model was used based on a quasi-likelihood approach (QIC) with an independent working correlation structure.

Results

The rate (per 100,000 census population of children age 3 and younger) of confirmed and possible SBS diagnosis codes was 5.4 (± 0.3) between 1998 and 2014, whereas the rate of non-SBS abuse was 19.6 (± 1.0). The rate of confirmed SBS diagnosis codes increased from 3.8 (± 0.3) in 1998 to 5.1 (± 0.9) in 2005, and decreased to 1.3 (± 0.2) in 2014. Possible SBS diagnosis codes were 0.6 (± 0.2) in 1998, increasing to 2.4 (± 0.4) in 2014. Confirmed SBS diagnosis codes have declined since 2002, while possible SBS diagnosis codes have increased. All abuse types were more frequent among infants, males, children from low-income homes, and urban teaching hospitals.

Conclusions

We investigated seventeen-year trends of SBS diagnosis codes among young children hospitalized for abuse. The discrepancy between trends in possible and confirmed SBS diagnosis codes suggests differences in norms for utilizing SBS diagnosis codes, which has implications for which hospital admissions are coded as AHT. Future research should investigate processes for using SBS diagnosis codes and whether all codes associated with abusive head injuries in young children are classified as AHT. Our findings also highlight the relativity defining and applying SBS diagnosis codes to children admitted to the hospital for shaking injuries. Medical professionals find utility in using SBS diagnosis codes, though may be more apt to apply codes related to possible SBS diagnosis codes in children presenting with abusive head injuries. Clarifying norms for SBS diagnosis codes and refining definitions for AHT diagnosis will ensure that young children presenting with, and coded for, abusive head injuries are included in overall counts of AHT based on secondary data of diagnosis codes. This baseline data, an essential component of child abuse surveillance, will enable ongoing efforts to track, prevent, and reduce child abuse.
Effects of different sodium salts and nitrogen sources on the production of 3-hydroxybutyrate and polyhydroxybutyrate by Burkholderia cepacia
Authors: Wang Jianfei , Huang Jiaqi , Guo Huanyu , Jiang Shaoming , Qiao Jinyue , Chen Xingyu , Qu Zixuan , Cui Wanyue , Liu Shijie
Published: July 2021

The effects of NaCl, Na2SO4, Na2HPO4, and Na3C6H5O7on the production of 3-hydroxybutyrate, polyhydroxybutyrate, and by-products byBurkholderia cepacia. Proper addition of Na3C6H5O7can significantly promote the production of 3-hydroxybutyric acid and polyhydroxybutyrate. The concentration, productivity, and yield of 3-hydroxybutyrate were increased by 48.2%, 55.6%, and 48.3% at 16 mM Na3C6H5O7. The increases of 80.1%, 47.1%, and 80.0% in the concentration, productivity, and yield of polyhydroxybutyrate were observed at 12 mM Na3C6H5O7. Na2SO4and Na2HPO4also have positive effects on the production capacity of 3-hydroxybutyrate and polyhydroxybutyrate within a certain range of concentration. NaCl is not conducive to the improvement of fermentation efficiency. Compared with a single nitrogen source, a mixed nitrogen source is more conducive to enhancing the production of 3-hydroxybutyrate and polyhydroxybutyrate.
Cardiovascular benefits of Momordica charantia in cholesterol-fed Wistar rats
Authors: Innih Silvanus Olu , Eze Ikechi Gerald , Omage Kingsley
Published: July 2021

Background

Momordica. charantia is popularly used as a medicinal herb in ethnomedicine for the management of cardiovascular diseases. In this study, we evaluated the beneficial effects of the ethanolic extract of M. charantia (Linn.) in experimentally induced cardiovascular disorders using cholesterol-fed Wistar rat.

Methods

Seventy-two experimental rats were randomly assigned into nine 9 groups of 8 rats each and treated as follows: Rats in group A (control) were given distilled water only; Rats in group B were given 30 mg/kg of cholesterol dissolved in coco-nut oil (cholesterol solution); Rats in group C were given cholesterol solution and 100 mg/kg Atorvastatin; Rats in group D were given 250 mg/kg of M. charantia and cholesterol solution; Rats in group E were given 500 mg/kg of M. charantia and cholesterol solution; Rats in group F were given 250 mg/kg. M. charantia; Rats in group G were given 500 mg/kg M. charantia; Rats in group H were given 1 ml of coconut oil; Rats in group I were given 100 mg/kg of Atorvastatin.

Results

Mean LDL-cholesterol was significantly (P < 0.05) lower in groups F, E and H as compared with the control groups. Histological analysis of the heart and aortic branch of the experimental rats show that cholesterol administration induced myocardial degeneration, vascular ulceration and stenosis in the aorta and heavy perivascular infiltrates of inflammatory cells. However, these deleterious effects were ameliorated upon treatment with Momordica charantia and Atorvastatin as compared with the control groups.

Conclusion

Our findings indicate the possible cardiovascular benefits of M. charantia.
Cross-cultural adaptation and psychometric properties of the Kessler Distress Scale (K10): an application of the rating scale model
Authors: Peixoto Evandro Morais , Zanini Daniela Sacramento , de Andrade Josemberg Moura
Published: July 2021

Background

The Kessler Distress Scale (K10) is a self-report scale for the assessment of non-specific psychological distress in the general and clinical population. Because of its ease of application and good psychometric properties, the K10 has been adapted to several cultures. The present study seeks to adapt the K10 to Brazilian Portuguese and estimate its validity evidence and reliability.

Methods

A total of 1914 individuals from the general population participated in the study (age = 34.88, SD = 13.61, 77.7% female). The adjustment indices were compared among three different measurement models proposed for the K10 through confirmatory factor analysis (CFA). The items’ properties were analyzed by Andrich’s Rating Scale Model (RSM). Furthermore, evidence based on relations to other variables (depression, stress, anxiety, positive and negative affects, and satisfaction with life) was estimated.

Results

CFA indicated the adequacy of the bifactor model (CFI= 0.985; TLI= 0.973; SMR= 0.019; RMSEA= 0.050), composed of two specific factors (depression and anxiety) and one general factor (psychological distress), corresponding to the theoretical hypothesis. Additionally, it was observed multiple-group invariance by gender and age range. The RSM provided an understanding of the organization of the continuum represented by the psychological distress construct (items difficulty), which varied from −0.89 to 1.00; good adjustment indexes; infit between 0.67 and 1.32; outfit between 0.68 and 1.34; and desirable reliability, α= 0.87. Lastly, theoretically coherent associations with the external variables were observed.

Conclusions

It is concluded that the Brazilian version of the K10 is a suitable measure of psychological distress for the Brazilian population.
Finding formulas: Does active search facilitate appropriate generalization?
Authors: Hallinen Nicole R. , Sprague Lauren N. , Blair Kristen P. , Adler Rebecca M. , Newcombe Nora S.
Published: July 2021

Background

One criterion of adaptive learning is appropriate generalization to new instances based on the original learning context and avoiding overgeneralization. Appropriate generalization requires understanding what features of a solution are applicable in a new context and whether the new context requires modifications or a new approach. In a series of three experiments, we investigate whether searching for an algebraic formalism before receiving direct instruction facilitates appropriate generalization.

Results

(1) Searching buffers against negative transfer: participants who first searched for an equation were less likely to overgeneralize compared to participants who completed a tell-and-practice activity. (2) Likelihood of creating a correct new adaptation varied by performance on the searching task. (3) Asking people to sketch alleviated some of the negative effects of tell-and-practice, but sketching did not augment the effect of searching. (4) When participants received more elaborate tell-and-practice instruction, the advantages of searching were less notable.

Conclusions

Searching for an algebraic formula prior to direct instruction may be a productive way to help learners connect a formula to its referent and avoid overgeneralization. Tell-and-practice instruction that only described the mathematical procedures led to the greatest levels of overgeneralization errors and worst performance. Tell-and-practice instruction that highlighted connections between the mathematical structure of the formula and the visual referent performed at similar or marginally worse levels than the search-first conditions.
Kuaishou short video social network from the perspective of urban-rural cultural linkage: a field study on the mobile internet practices of young Monguor villagers in China’s Qinghai Province
Authors: Ji Guangxu
Published: July 2021

This paper uses the shooting and posting of Kuaishou short videos by young villagers in Wushi Village, Wushi Town, Huzhu Autonomous County, Qinghai Province, China as a case study, attempting to explore the cultural significance of the Kuaishou Short Video Social Network frequently used in our daily lives. The short videos of those young villagers not only show the overlapping of online and offline spaces in urban and rural areas, but also present another possibility of the coexistence between urban and rural cultures in the new era of Internet. Kuaishou has become a metaphor and a stage for the ambiguity and coexistence of urban and rural boundaries by virtue of the relative ease and availability of short video editing. The use of Kuaishou by young Monguor villagers is of great significance in addressing the traditional urban-rural dual economic structure.
Development and validation of RP-HPLC method for estimation of brexpiprazole in its bulk and tablet dosage form using Quality by Design approach
Authors: Jagdale Amol S. , Pendbhaje Nilesh S. , Nirmal Rupali V. , Bachhav Poonam M. , Sumbre Dayandeo B.
Published: July 2021

Background

A new, sensitive, suitable, clear, accurate, and robust reversed-phase high-performance liquid chromatography (RP-HPLC) method for the determination of brexpiprazole in bulk drug and tablet formulation was developed and validated in this research. Surface methodology was used to optimize the data, with a three-level Box-Behnken design. Methanol concentration in the mobile phase, flow rate, and pH were chosen as the three variables. The separation was performed using an HPLC method with a UV detector and Openlab EZchrom program, as well as a Water spherisorb C18 column (100 mm × 4.6; 5m). Acetonitrile was pumped at a flow rate of 1.0 mL/min with a 10 mM phosphate buffer balanced to a pH of 2.50.05 by diluted OPA (65:35% v/v) and detected at 216 nm.

Result

The developed RP-HPLC method yielded a suitable retention time for brexpiprazole of 4.22 min, which was optimized using the Design Expert-12 software. The linearity of the established method was verified with a correlation coefficient (r2) of 0.999 over the concentration range of 5.05–75.75 g/mL. For API and formulation, the percent assay was 99.46% and 100.91%, respectively. The percentage RSD for the method’s precision was found to be less than 2.0%. The percentage recoveries were discovered to be between 99.38 and 101.07%. 0.64 μg/mL and 1.95 μg/mL were found to be the LOD and LOQ, respectively.

Conclusion

The developed and validated RP-HPLC system takes less time and can be used in the industry for routine quality control/analysis of bulk drug and marketed brexpiprazole products.

Graphical abstract
Identification and phylogenetic analysis of two canine coronavirus strains
Authors: Gan Junji , Tang Ye , Lv Haifeng , Xiong Wenbin , Tian Xiaoyan
Published: July 2021

Canine coronavirus (CCoV), a member of the genus Alphacoronavirus, is an enveloped, single-stranded positive-sense RNA virus that responsible for gastroenteritis in dogs. In this study, two CCoV isolates were successfully propagated from 53 CCoV-positive clinical specimens by serial passaging in A-72 cells. These two strains, CCoV JS1706 and CCoV JS1712, caused cytopathic effects in A-72 cells. The sizes of virus plaque formed by them differed in early passages. Electron microscopy revealed a large quantity of typical coronavirus particles with 80–120 nm in diameter in cell culture media and cytoplasm of infected cells, in which they appeared as inclusion bodies. RT-PCR analysis of S gene indicated that these two isolates were belonged to CCoV IIa subtype. Homology of RdRp, S, M and N proteins between the two strains were 100, 99.6, 99.2 and 100.0%, respectively, whereas they were 99.4–100%, 83.1–95.2%, 88.5–99.2% and 91.9–99.7% identity compared to CCoV II reference strains. Phylogenetic analysis of RdRp, S, M and N protein showed that they were closely related to CCoV II strains. These two subtype IIa isolates will be useful for evaluating the pathogenesis and evolution of CCoV and for developing diagnostic reagents and vaccines.
Efficient spreading strategy for global solution search using a trust-region optimization method: An application to the common-reflection-surface stacking problem
Authors: Pisnitchenko Feodor , Sakamori Momoe
Published: July 2021

Some processes in seismic imaging can be formulated as a coherence-based problem, such as common-reflection-surface (CRS) stacking. The approach consists of obtaining the CRS attributes that provide the best-fitting CRS surface in the multicoverage data. The problem can be described as an optimization problem and is solved by an optimization algorithm. In general, quick convergent optimization algorithms are local solvers. To obtain a global solution, an efficient strategy has been developed to be used combined with a trust-region local optimization method. This strategy can be divided into two features: the sequential parameter search and the spreading solution. The idea is to first find solutions on a coarse output grid by a sequential parameter search. This feature is based on constructing splines to estimate the maxima of the objective function in one dimension. These estimated maxima are the initial approximations to the local solver. The optimization algorithm obtains the parameters by sequentially solving 1D, 2D, and 3D problems. Once the solutions are found on the coarse grid, useful information is propagated in the neighborhood to obtain the solutions on all output grids. Although the idea of spreading a solution seems easy, its implementation is complex. It is essential to consider the properties of the problem as well as the properties of the optimization algorithm. Through some numerical experiments, the results using this strategy are shown. The use of sequential parameter search and spreading solution provides an improvement not only in the parameters but also in computational time.
Identifying reflector azimuth from borehole multicomponent cross-dipole acoustic measurement
Authors: Li Chao , Chen Hao , He Xiao , Wang Xiuming
Published: July 2021

The borehole dipole shear-wave reflection imaging method has great potential in heterogeneous reservoir explorations because of its deep investigation depth and relatively large reflection amplitude. However, the generally used shear horizontal (SH) reflection approach can only indicate the reflector strike and has an inherent defect in azimuth ambiguity. We have developed a multicomponent cross-dipole array acoustic measurement with four azimuthally distributed receiver arrays and a method using reflected dipole P-waves to eliminate the azimuth ambiguity caused by the SH reflection. The recorded data include cross-dipole waves with four components and two combined dipole-monopole waves that stack the data of the four azimuthally distributed receivers induced by each dipole source. A theoretical analysis indicates that the dipole compressional reflection is sensitive to the reflector azimuth. Therefore, the cross-dipole waves are first used to determine the reflective interface strike with the SH reflection. The compressional reflections obtained from the cross-dipole data and the combined dipole-monopole data are then processed to identify the correct azimuth. The effectiveness and accuracy of the method are validated via synthetic and field data examples in a soft formation. Our method may potentially solve the azimuth ambiguity problem in borehole acoustic reflection imaging and fully use cross-dipole acoustic measurements.
Elastic isotropic and anisotropic full-waveform inversions using automatic differentiation for gradient calculations in a framework of recurrent neural networks
Authors: Wang Wenlong , McMechan George A. , Ma Jianwei
Published: July 2021

We have implemented multiparameter full-waveform inversions (FWIs) in the framework of recurrent neural networks in elastic isotropic and transversely isotropic media. A staggered-grid velocity-stress scheme is used to solve the first-order elastodynamic equations for forward modeling. The gradients of loss with respect to model parameters are obtained by automatic differentiation. Multiple elastic model parameters are simultaneously inverted with a minibatch optimizer. We prove the equivalency of full-batch automatic differentiation and the conventional adjoint-state method for inversions in elastic isotropic media. Synthetic tests on elastic isotropic models show that the minibatch configuration has a better convergence rate and higher inversion accuracy than full-batch elastic FWIs. Inversions with data that contain incoherent and coherent noise are tested, respectively. With automatic differentiation, we determine the ease of extension to anisotropic media with two parameterizations, and the potential to implement it for more general media.
3D electromagnetic modeling of graphitic faults in the Athabasca Basin using a finite-volume time-domain approach with unstructured grids
Authors: Lu Xushan , Farquharson Colin G. , Miehé Jean-Marc , Harrison Grant
Published: July 2021

Uranium exploration in the Athabasca Basin, Canada, relies heavily on ground-based transient electromagnetic (TEM) surveys to target thin, steeply dipping graphitic conductors that are often closely related to the uranium ore deposits. The interpretation of TEM data is important in identifying the locations and trends of conductors to guide subsequent drilling campaigns. We develop a trial-and-error modeling approach and demonstrate its application to the interpretation of a data set acquired at the Close Lake in the Athabasca Basin. The modeling process has two key tasks: building geoelectric models and computing their TEM responses. The modeling process is repeated with the geoelectric model being iteratively refined based on the match between three-component calculated and measured data from early to late times. To create geoelectric models, we first build a realistic geologic model and discretize it using an unstructured tetrahedral mesh, with each mesh cell populated with appropriate resistivities. To calculate the TEM responses of the geoelectric model, we use a 3D finite-volume time-domain algorithm. We construct our initial model based on existing geologic information and drilling data. We find that this modeling process is flexible and can easily handle thin, steeply dipping conductive graphitic fault models with variable resistivities in the fault and background and with topography. Our interpretation of the Close Lake data matches well with the trend and location of the main conductor as revealed by drilling data and also confirms the existence of a smaller conductor that only caused noticeable anomalous responses in early-time horizontal-component data. The smaller conductor was suggested by previous electromagnetic data but was missed in a recent interpretation based on the modeling of only late-time vertical-component data with plate-based approximate modeling methods.
Introduction of the Hessian in joint migration inversion and improved recovery of structural information using image-based regularization
Authors: Assis Carlos A. M. , Schleicher Jörg
Published: July 2021

Joint migration inversion (JMI) is a method based on one-way wave equations that aims at fitting seismic reflection data to estimate an image and a background velocity. The depth-migrated image describes the high spatial-frequency content of the subsurface and, in principle, is true amplitude. The background velocity model accounts mainly for the large spatial-scale kinematic effects of the wave propagation. Looking for a deeper understanding of the method, we briefly review the continuous equations that compose the forward-modeling engine of JMI for acoustic media and angle-independent scattering. Then, we use these equations together with the first-order adjoint-state method to arrive at a new formulation of the model gradients. To estimate the image, we combine the second-order adjoint-state method with the truncated-Newton method to obtain the image updates. For the model (velocity) estimation, in comparison to the image update, we reduce the computational cost by adopting a diagonal preconditioner for the corresponding gradient in combination with an image-based regularizing function. Based on this formulation, we build our implementation of the JMI algorithm. Our image-based regularization of the model estimate allows us to carry over structural information from the estimated image to the jointly estimated background model. As demonstrated by our numerical experiments, this procedure can help to improve the resolution of the estimated model and make it more consistent with the image.
Simulation of borehole acoustic wavefields in fractured media by combining the spectral-element method and linear-slip model
Authors: Xu Jiaqi , Liu Qing Huo , Hu Hengshan , Zhong Yang
Published: July 2021

We have used the spectral-element method (SEM) to simulate 3D acoustic wavefields in the fluid-filled borehole embedded in fractured media. The fractures are characterized by the linear-slip model (LSM), which is incorporated into the surface integral of the SEM weak form, avoiding meshing individual fractures, thus reducing the degrees of freedom of the fractures compared with meshing each fracture directly. For the fracture-free case, we validate SEM through the comparison with the real-axis integration method for monopole and dipole sources. For the case with a fracture, we compare the SEM-LSM solutions with the reference numerical solutions of a thin-layer model using the finite-difference method. Good agreement is achieved between the results from our method and the reference finite-difference solutions. We find that the acoustic wavefields excited by a dipole source are more sensitive to the fractures than those by a monopole source. To show the ability of the approach to handle complex problems, we simulate the cases with a tilted fracture and multiple fractures. Based on the simulated results, we investigate the influence of the fracture parameters (e.g., stiffness, tilt angle, azimuth, thickness, number, and spatial intervals of fractures) on the scattered wavefields. We find that the tilt angle has an obvious influence on the scattered waveforms and amplitudes. The results also demonstrate that the wavefields are quite sensitive to the number of fractures. The magnitudes of the horizontal components’ transmitted wavefields decrease linearly with the number of fractures. Through analyzing the synthetic data in the time and frequency domains, we discuss how to evaluate the properties of fractures intersected by a borehole.
Characterization of gas hydrate systems on the Hikurangi margin (New Zealand) through geostatistical seismic and petrophysical inversion
Authors: Turco Francesco , Azevedo Leonardo , Grana Dario , Crutchley Gareth J. , Gorman Andrew R.
Published: July 2021

Quantitative characterization of gas hydrate systems on continental margins from seismic data is challenging, especially in regions where no well logs are available. However, probabilistic seismic inversion provides an effective means for constraining the physical properties of subsurface strata in such settings and analyzing the variability related to the results. We have applied a workflow for the characterization of two deepwater gas hydrate reservoirs east of New Zealand, where high concentrations of gas hydrate have been inferred previously. We estimate porosity and gas hydrate saturation in the reservoirs from multichannel seismic data through a two-step procedure based on geostatistical seismic and Bayesian petrophysical inversion built on a rock-physics model for gas hydrate-bearing marine sediments. We find that the two reservoirs together host between [Formula: see text] and [Formula: see text] of gas hydrate, with the best estimate at [Formula: see text]. This estimate provides a first-order assessment for further gas hydrate evaluations in the region. The two-step statistically based seismic inversion method is an effective approach for characterizing gas hydrate systems from long-offset seismic reflection data.
SeReMpy: Seismic reservoir modeling Python library
Authors: Grana Dario , de Figueiredo Leandro
Published: July 2021

Seismic reservoir characterization is a subfield of geophysics that combines seismic and rock-physics modeling with mathematical inverse theory to predict reservoir variables from the measured seismic data. An open-source comprehensive modeling library that includes the main concepts and tools is still missing. We have developed a Python library called SeReMpy with state-of-the-art of seismic reservoir modeling for reservoir properties characterization using seismic and rock-physics models and Bayesian inverse theory. The most innovative component of the library is the Bayesian seismic and rock-physics inversion to predict the spatial distribution of petrophysical and elastic properties from seismic data. The inversion algorithms include Bayesian analytical solutions of the linear-Gaussian inverse problem and Markov chain Monte Carlo (MCMC) numerical methods for nonlinear problems. The library includes four modules: geostatistics, rock physics, facies, and inversion, as well as several scripts with illustrative examples and applications. We illustrate the use of the functions of the module and develop codes for practical inversion problems using synthetic and real data. The applications include a rock-physics model for the prediction of elastic properties and facies using well-log data, a geostatistical simulation of continuous and discrete properties using well logs, a geostatistical interpolation and simulation of 2D maps of temperature, an elastic inversion of partial stacked seismograms with Bayesian linearized amplitude-variation-with-offset inversion, a rock-physics inversion of partial stacked seismograms with MCMC methods, and a 2D seismic inversion.
3D ground-penetrating radar attributes to generate classified facies models: A case study from a dune island
Authors: Koyan Philipp , Tronicke Jens , Allroggen Niklas
Published: July 2021

Ground-penetrating radar (GPR) is a standard geophysical technique used to image near-surface structures in sedimentary environments. In such environments, GPR data acquisition and processing are increasingly following 3D strategies. However, the processed GPR data volumes are typically still interpreted using selected 2D slices and manual concepts such as GPR facies analyses. In seismic volume interpretation, the application of (semi-)automated and reproducible approaches such as 3D attribute analyses as well as the production of attribute-based facies models are common practices today. In contrast, the field of 3D GPR attribute analyses and corresponding facies models is largely untapped. We have developed and applied a workflow to produce 3D attribute-based GPR facies models comprising the dominant sedimentary reflection patterns in a GPR volume, which images complex sandy structures on the dune island of Spiekeroog (Northern Germany). After presenting our field site and details regarding our data acquisition and processing, we calculate and filter 3D texture attributes to generate a database comprising the dominant texture features of our GPR data. Then, we perform a dimensionality reduction of this database to obtain meta texture attributes, which we analyze and integrate using composite imaging and (also considering additional geometric information) fuzzy c-means cluster analysis resulting in a classified GPR facies model. Considering our facies model and a corresponding GPR facies chart, we interpret our GPR data set in terms of near-surface sedimentary units, the corresponding depositional environments, and the recent formation history at our field site. Thus, we demonstrate the potential of our workflow, which represents a novel and clear strategy to perform a more objective and consistent interpretation of 3D GPR data collected across different sedimentary environments.
Data-driven prestack-waveform inversion using genetic algorithm: Methodology and examples
Authors: Jia Lingxiao , Mallick Subhashis , Wang Cheng
Published: July 2021

The choice of an initial model for seismic waveform inversion is important. In matured exploration areas with adequate well control, we can generate a suitable initial model using well information. However, in new areas where well control is sparse or unavailable, such an initial model is compromised and/or biased by the regions with more well controls. Even in matured exploration areas, if we use time-lapse seismic data to predict dynamic reservoir properties, an initial model that we obtain from the existing preproduction wells could be incorrect. In this work, we outline a new methodology and workflow for a nonlinear prestack isotropic elastic waveform inversion. We call this method a data-driven inversion, meaning that we derive the initial model entirely from the seismic data without using any well information. By assuming a locally horizontal stratification for every common midpoint and starting from the interval P-wave velocity, estimated entirely from seismic data, our method generates pseudowells by running a two-pass 1D isotropic elastic prestack-waveform inversion that uses the reflectivity method for forward modeling and the genetic algorithm for optimization. We then use the estimated pseudowells to build the initial model for seismic inversion. By applying this methodology to real seismic data from two different geologic settings, we determine the usefulness of our method. We believe that our new method is potentially applicable for subsurface characterization in areas where well information is sparse or unavailable. Additional research is, however, necessary to improve the computational efficiency of the methodology.
Circulating Bile Acid Profiles: A Need for Further Examination
Authors: Qi Li , Tian Yu , Chen Yongsheng
Published: July 2021

Context

Bile acids (BAs) are increasingly recognized as metabolic and chronobiologic integrators that synchronize the systemic metabolic response to nutrient availability. Alterations in the concentration and/or composition of circulating BAs are associated with a number of metabolic disorders, such as obesity, type 2 diabetes mellitus (T2DM), insulin resistance (IR), and metabolic associated fatty liver disease (MAFLD). This review summarizes recent evidence that links abnormal circulating BA profiles to multiple metabolic disorders, and discusses the possible mechanisms underlying the connections to determine the role of BA profiling as a novel biomarker for these abnormalities.

Evidence Acquisition

The review is based on a collection of primary and review literature gathered from a PubMed search of BAs, T2DM, IR, and MAFLD, among other keywords.

Evidence Synthesis

Obese and IR subjects appear to have elevated fasting circulating BAs but lower postprandial increase when compared with controls. The possible underlying mechanisms are disruption in the synchronization between the feeding/fasting cycle and the properties of BA-regulated metabolic pathways. Whether BA alterations are associated per se with MAFLD remains inconclusive. However, increased fasting circulating BAs level was associated with higher risk of advanced fibrosis stage. Thus, for patients with MAFLD, dynamically monitoring the circulating BA profiles may be a promising tool for the stratification of MAFLD.

Conclusions

Alterations in the concentration, composition, and rhythm of circulating BAs are associated with adverse events in systemic metabolism. Subsequent investigations regarding these aspects of circulating BA kinetics may help predict future metabolic disorders and guide therapeutic interventions.
Association of HbA1c With All-cause Mortality Across Varying Degrees of Glycemic Variability in Type 2 Diabetes
Authors: Lu Jingyi , Wang Chunfang , Cai Jinghao , Shen Yun , Chen Lei , Zhang Lei , Lu Wei , Zhu Wei , Hu Gang , Xia Tian , Zhou Jian
Published: July 2021

Context

The interaction of glycated hemoglobin A1c (HbA1c) and glycemic variability in relation to diabetes-related outcomes remains unknown.

Objective

To evaluate the relationship between HbA1c and all-cause mortality across varying degrees of glycemic variability in patients with type 2 diabetes.

Design, Setting, and Patients

This was a prospective study conducted in a single referral center. Data of 6090 hospitalized patients with type 2 diabetes was analyzed. Glucose coefficient of variation [coefficient of variation (CV)] was obtained as the measure of glycemic variability by using continuous glucose monitoring for 3 days. Cox proportional hazards regression models were used to estimate hazard ratios and 95% CIs for all-cause mortality.

Results

During a median follow-up of 6.8 years, 815 patients died. In patients with the lowest and middle tertiles of glucose CV, HbA1c ≥ 8.0% was associated with 136% (95% CI 1.46-3.81) and 92% (95% CI 1.22-3.03) higher risks of all-cause mortality, respectively, as compared with HbA1c 6.0%-6.9%, after adjusting for confounders. However, a null association of HbA1c with mortality was found in patients with the highest tertile of glucose CV.

Conclusions

HbA1c may not be a robust marker of all-cause mortality in patients with high degree of glycemic variability. New metrics of glycemic control may be needed in these individuals to achieve better diabetes management.
Parental Rights and the Temporality of Attachment: Law, Kinship, and Child Welfare in Japan
Authors: Goldfarb Kathryn E.
Published: July 2021

This article explores the legal norms and regulatory mechanisms in Japan that structure child welfare placement decisions, focusing specifically on the legal category of “parental rights.” It is suggested that the ways child welfare officers and caregivers understand the concept of “rights”—both those of the biological parent(s) and the child—construe kinship relationships as problems to be managed, but with a particular orientation toward what is called in the article the temporality of attachment. Child welfare caseworkers’ understandings of legal categories, processes, and forms of documentation (such as the Japanese family registry) produce particular forms of kinship that prioritize a child's possible future relationship with an absent parent, above and beyond the day-to-day relationships children might develop with alternative caregivers such as foster parents. Despite the fact that the author's Japanese interlocutors often described kinship as an immutable relationship of blood ties, the author shows how kinship is in fact produced through specific encounters between (mostly absent) parents and their children, child welfare caseworkers, and foster and institutional caregivers, scaffolded by their engagement with legal and bureaucratic regimes. The article explores what parenthood means within Japanese child welfare, both as a temporalized form of relationality and as a set of legally structured claims to the right to care.
Not Entirely Married: Resisting the Hegemonic Patrilineal Family in Japan's Household Registry
Authors: White Linda
Published: July 2021

The koseki 戸籍 (family or household registry) has long served as a material representation of the conceptual structure of Japanese family relations. Membership in a family has been stipulated and proved through registration in a koseki document defined through a shared surname and address. Evidence of family membership for purposes of legal transactions and social interactions has rested in the koseki document. However, during the past several decades some women have questioned the social pressure and legal requirement to change their names in marriage, choosing instead to maintain their surname by refusing to register their marriages to their “husbands.” Claiming themselves “married” but not legally registering their marriages, this growing group of name-change resisters defines their nonregistered marriages as jijitsukon 事実婚 (common-law or real marriage). Drawing on ethnographic research with women in jijitsukon marriages in Tokyo who refuse to share a koseki with their “husbands,” this article explores the implications of marital registration resistance in a marriage-centric society and the concurrent critique of the koseki system (the Koseki Law, koseki document, and the broader system of registration) and the legal marriage structure at the core of women's claims to be married when they do not meet Japan's legal criteria for marriage.
Lesbian and Gay Parents, Heterosexual Kinship, and Queer Dreams: Making Families in Twenty-First Century Taiwan
Authors: Brainer Amy
Published: July 2021

This article analyzes ways that legal and social understandings of kinship intersect for Taiwanese queer parents and prospective parents. Parents in this research experience varying degrees of legal and cultural intelligibility within the existing household registration system and the familial contexts in which they reside and carry out their daily lives. Many are rearing children in multigenerational, extended family households and are juggling a variety of gendered family roles and responsibilities that shape their parenting practices. Their experiences highlight the limits of rights discourses that treat marriage and parenthood as largely class- and gender-neutral institutions and presuppose a nuclear family model. Such uncritical approaches to marriage and parenthood leave the normative power of these systems intact even as they provisionally open to greater numbers of people. The article foregrounds pathways to parenthood and struggles for legal recognition among queers in a variety of family arrangements, including those that do not fit within the conventional representation of a cohabiting and marriage-desiring same-sex couple with children.