bluuebunny/crossref_metadata_2025 huggingface dataset:
Adverse Outcomes during Postpartum Readmissions after Deliveries Complicated by Hypertensive Disorders of Pregnancy
Authors: Emeruwa Ukachi N. , Gyamfi-Bannerman Cynthia , Wen Timothy , Booker Whitney , Wright Jason D. , Huang Yongmei , D'Alton Mary E. , Friedman Alexander M.
Published: November 2021

Objective This study aimed to characterize risk for postpartum complications based on specific hypertensive diagnosis at delivery.

Study Design This retrospective cohort study used the 2010 to 2014 Nationwide Readmissions Database to identify 60-day postpartum readmissions. Delivery hospitalizations were categorized based on hypertensive diagnoses as follows: (1) preeclampsia with severe features, (2) superimposed preeclampsia, (3) chronic hypertension, (4) preeclampsia without severe features, (5) gestational hypertension, or (6) no hypertensive diagnosis. Risks for 60-day readmission was determined based on hypertensive diagnosis at delivery. The following adverse outcomes during readmissions were analyzed: (1) stroke, (2) pulmonary edema and heart failure, (3) eclampsia, and (4) severe maternal morbidity (SMM). We fit multivariable log-linear regression models to assess the magnitude of association between hypertensive diagnoses at delivery and risks for readmission and associated complications with adjusted risk ratios (aRR) as measures of effect.

Results From 2010 to 2014, 15.7 million estimated delivery hospitalizations were included in the analysis. Overall risk for 60-day postpartum readmission was the highest among women with superimposed preeclampsia (6.6%), followed by preeclampsia with severe features (5.2%), chronic hypertension (4.0%), preeclampsia without severe features (3.9%), gestational hypertension (2.9%), and women without a hypertensive diagnosis (1.5%). In adjusted analyses for pulmonary edema and heart failure as the outcome, risks were the highest for preeclampsia with severe features (aRR = 7.82, 95% confidence interval [CI]: 6.03, 10.14), superimposed preeclampsia (aRR = 8.21, 95% CI: 5.79, 11.63), and preeclampsia without severe features (aRR = 8.87, 95% CI: 7.06, 11.15). In the adjusted model for stroke, risks were similarly highest for these three hypertensive diagnoses. Evaluating risks for SMM during postpartum readmission, chronic hypertension and superimposed preeclampsia were associated with the highest risks.

Conclusion Chronic hypertension was associated with increased risk for a broad range of adverse postpartum outcomes. Risk estimates associated with chronic hypertension with and without superimposed preeclampsia were similar to preeclampsia with severe features for several outcomes.

Key Points
Empirical asset pricing via machine learning: evidence from the European stock market
Authors: Drobetz Wolfgang , Otto Tizian
Published: November 2021

This paper evaluates the predictive performance of machine learning methods in forecasting European stock returns. Compared to a linear benchmark model, interactions and nonlinear effects help improve the predictive performance. But machine learning models must be adequately trained and tuned to overcome the high dimensionality problem and to avoid overfitting. Across all machine learning methods, the most important predictors are based on price trends and fundamental signals from valuation ratios. However, the models exhibit substantial variation in statistical predictive performance that translate into pronounced differences in economic profitability. The return and risk measures of long-only trading strategies indicate that machine learning models produce sizeable gains relative to our benchmark. Neural networks perform best, also after accounting for transaction costs. A classification-based portfolio formation, utilizing a support vector machine that avoids estimating stock-level expected returns, performs even better than the neural network architecture.
Rotation
Authors: Mårtensson-Pendrill Ann-Marie
Published: November 2021

How do we know the Earth spins around its axis? How can we be sure that it is not the Sun moving around the Earth, causing sunrises and sunsets, day and night? Like acceleration, rotation is absolute and can be measured without looking at the surroundings, as a motion in a rotating system needs a sideways force to follow a straight line—the Coriolis effect. Many modern smart phones have built-in rotation sensors with two small wings that are made to vibrate. Rotation then requires a force or torque which creates an electronic signal for these “butterfly gyroscopes”. A carousel provides possibilities to explore physics in rotating systems and to gain first-hand experience of methods to measure rotation, without the need for an external reference, including the classic Foucault pendulum experiment. Amusement rides often involve rotation around more than one axis, and smartphones provide ways to measure rotation and discern new aspects of motion.
Physics on a Playground
Authors: Mårtensson-Pendrill Ann-Marie
Published: November 2021

A playground visit can be used to support the teaching about force and motion at different levels, from preschool to university. It can also be used as a preparation for amusement park physics days. A playground visit gives easier access and more freedom to experiment with the motion and with different objects than amusement park rides.

The chapter starts with a presentation of investigations on a small playground with climbing racks, slides, and swings. This introduction is followed by brief discussions of possibilities on large playgrounds, including parabolic whispering dishes, see-saws, carousels, spinning bowls, and trampolines. Thematic investigations to integrate playground experiences into the curriculum are suggested for several concepts: equivalence between gravitational and inertial mass (the equivalence principle); torque and angular momentum; work and energy as well as friction and rolling on inclined planes. Finally, the organization of playground teacher days is discussed to support sharing the joy of physics with teachers for younger students.
Tropical fever in remote tropics: tuberculosis or melioidosis, it depends on the lab
Authors: Warner Jeffrey , Rush Catherine
Published: November 2021

Diagnostics tests used to identify the cause of infection using proteomics and genomics have revolutionised microbiology laboratories in recent times. However, approaches to build the capacity of clinical microbiology services in the rural tropics by simply transplanting these approaches have proven difficult to sustain. Tropical fever in the remote tropics is, by definition, a clinical diagnosis where the aetiology of fever is not known, treatment is empirical, guided by clinical suspicion with treatment failure often attributed to incorrect diagnosis or antimicrobial resistance. Tuberculosis (TB) in rural Papua New Guinea (PNG) is mostly diagnosed clinically, perhaps supported by microscopy. In fact, a ‘tuberculosis patient’ in rural PNG is included in the TB register upon commencement of TB treatment with or without any laboratory-based evidence of infection. The roll-out of GeneXpert is continuing to transform TB diagnostic certainty in TB endemic communities. Melioidosis is endemic in tropical regions and is increasingly reported to mimic TB. Isolation and identification of the causative agent Burkholderia pseudomallei remains the gold standard. Here, we discuss the increasing divide between rural and urban approaches to laboratory-based infection diagnosis using these two enigmatic tropical infectious diseases, in rural PNG, as examples.
Introns encode dsRNAs undetected by RIG-I/MDA5/interferons and sensed via RNase L
Authors: Chitrakar Alisha , Solorio-Kirpichyan Kristina , Prangley Eliza , Rath Sneha , Du Jin , Korennykh Alexei
Published: November 2021

Significance

Double-stranded RNA (dsRNA) is the strongest-known “molecular signature” of viral infections that activates antiviral interferon responses and inflammation in human cells. Due to this activity, dsRNA-sensing pathways belong to the core interests of academic laboratories and pharma working on antiviral defenses and inflammatory diseases. dsRNAs do not always arise from viral infections. Mammalian cells can also produce their own dsRNAs. Precisely what are the endogenous dsRNAs that activate innate immune responses in human cells, and which receptors of the innate immune system sense endo-dsRNAs? Here, we find that human endo-dsRNAs can arise from jammed decay of intronic and intergenic transcripts folded as RNA duplexes. We show that the receptors OAS3/RNase L and PKR are important sensors of these dsRNAs.
What do (some of) our association measures measure (most)? Association?
Authors: Gries Stefan Th.
Published: November 2021

This paper discusses the degree to which some of the most widely-used measures of association in corpus linguistics are not particularly valid in the sense of actually measuring association rather than some amalgam of a lot of frequency and a little association. The paper demonstrates these issues on the basis of hypothetical and actual corpus data and outlines implications of the findings. I then outline how to design an association measure that only measures association and show that its behavior supports the use of the log odds ratio as a true association-only measure but separately from frequency; in addition, this paper sets the stage for an analogous review of dispersion measures in corpus linguistics.
The politicization of Sufism in Chechnya
Authors: Vatchagaev Mairbek
Published: November 2021

The present article analyses the evolution of Sufism in Chechnya. The study of the Sufi community, by one of its members, contributes to an understanding of the changes that took place in Chechen society in the second half of the twentieth century. Particular attention is paid to the integration of Sufi orders into the political system of the Republic. This essay investigates the isolation of Chechen Sufism from the rest of the Sufi world and its reasons, likewise its impact on the formation of a specifically Chechen Sufism. First among studies of North Caucasian Sufism, it raises the issue of the substitution of the political system by Sufi orders. There is a growing tendency towards the politicisation of Sufism in Chechnya, reflecting the alliance of Sufi orders with government. It is also a result of the quest for a political system in Chechen society, where clan relations are still strong.
Mitochondrial calpain inhibition restores defective SR-mitochondrial crosstalk in CPVT rat myocytes
Authors: Hamilton Shanna , Terentyeva Radmila , Veress Roland , Perger Fruzsina , Martin Benjamin Y. , Gyorke Sandor , Belevych Andriy E. , Terentyev Dmitry
Published: November 2021

Cardiac RYR2-mediated sarcoplasmic Ca2+ (SR) release is essential for matching increased energy demand during fight-or-flight response with mitochondrial metabolic output by delivering Ca2+ into the mitochondrial matrix to activate Ca2+-dependent Krebs cycle dehydrogenases. RYR2 complex gain-of-function mutations associated with catecholaminergic polymorphic ventricular tachycardia (CPVT) have been linked to mitochondrial structural damage and enhanced production of reactive oxygen species (ROS). Despite being critical for arrhythmogenesis in CPVT, the exact causes of these phenomena remain undetermined. Taking advantage of a new rat model of CPVT induced by heterozygous RYR2 gain-of-function mutation S2222L, we tested how RYR2 overactivity alters mitochondrial Ca2+ and ROS handling, and how these changes cause mitochondrial structural defects. Injection of epinephrine (1 mg/kg) and caffeine (120 mg/kg) induced bigamy and bidirectional VT in vivo in 100% of CPVT rats. Simultaneous whole-cell patch clamp and confocal Ca2+-imaging demonstrated that under β-adrenergic stimulation with isoproterenol (50 nM), CPVT ventricular myocytes (VMs) exhibited severe Ca2+ mishandling and high propensity for generation of spontaneous Ca2+ waves (SCWs) that cause arrhythmogenic afterdepolarizations. Diminished Ca2+ transient amplitude in CPVT VMs resulted in a significant reduction in mitochondrial matrix–[Ca2+], and thereby a mito-ROS surge, visualized using matrix-targeted biosensors mtRCaMP1h and MLS-HyPer, respectively. Importantly, using novel Ca2+-biosensors targeted to intermembrane space (IMS-GECO), we uncovered that [Ca2+] in this compartment reaches 1 µM, sufficient for activation of Ca2+-dependent protease μ-calpain. Adenoviral overexpression of IMS-targeted calpastatin, an endogenous calpain inhibitor, reduced mito-ROS, restored cytosolic Ca2+ transient amplitude and SR Ca2+ content, and reduced RYR2-mediated SCWs in CPVT VMs. These changes were paralleled by restored expression levels of OPA1, a mitochondrial structural protein responsible for tight cristae organization. Our data suggest that enhanced mito-ROS due to matrix-[Ca2+] reduction in CPVT VMs and unexpectedly high IMS-[Ca2+] promotes IMS-calpain–mediated degradation of OPA1, resulting in mitochondrial structural damage that contributes to proarrhythmic remodeling.
Effects of HOCl oxidation on excitation–contraction coupling: Implications for the pathophysiology of Duchenne muscular dystrophy
Authors: Lea Thomas A. , Pinniger Gavin J. , Arthur Peter G. , Bakker Tony J.
Published: November 2021

Duchenne muscular dystrophy (DMD) is a fatal X-linked genetic disease characterized by progressive loss of skeletal muscle. The mechanisms underlying the DMD pathology likely involve the complex interaction between reactive oxygen species (ROS) impaired Ca2+ handling and chronic inflammation, characterized by the presence of immune cells such as neutrophils. Hypochlorous acid (HOCl) is a highly reactive form of ROS produced endogenously via the actions of myeloperoxidase, an enzyme secreted by neutrophils. Myeloperoxidase activity is significantly elevated in dystrophic muscle. This study aimed to determine the effect of HOCl exposure on excitation–contraction coupling and its potential contribution to the dystrophic pathology. Isolated extensor digitorum longus (EDL) muscles and single fibers from C57 (wild type) and mdx (dystrophic) mice were used to investigate the effects of HOCl on whole muscle function, intracellular Ca2+ handling, and myofilament force production. HOCl exposure significantly decreased maximum specific force in isolated EDL muscles by 26% and 49%, respectively, in C57 and mdx mice (P < 0.0001). In single interosseous fibers, HOCl exposure significantly increased resting intracellular Ca2+ concentration by ∼17–19% (P < 0.05) and decreased the amplitude of electrically induced Ca2+ transients by ∼45% and 50%, respectively, in C57 and mdx fibers (C57, P < 0.05; mdx, P < 0.01). These effects of HOCl on resting Ca2+ could be blocked via application of tetracaine (ryanodine receptor blocker) or Gd3+ (stretch-activated channel blocker; C57, P < 0.01; mdx, P < 0.01 for both). The effect of HOCl on Ca2+ transient amplitude was significantly reduced by Gd3+ (C57, P < 0.05; mdx, P < 0.01). In chemically skinned EDL fibers, HOCl exposure decreased maximum Ca2+-activated force by ∼40% in both C57 and mdx fibers (P < 0.001). These results indicate that HOCl potently affects excitation–contraction coupling via impaired Ca2+ handling and myofilament force production. Hence, HOCl potentially links the chronic inflammation, oxidative stress, and impaired Ca2+ handling that underlies the dystrophic pathology.
Arrhythmogenesis in heart cells involves reverse E–C coupling and reverse electrotonic conduction along T-tubules
Authors: Shioya Takao
Published: November 2021

Early afterdepolarization (EAD) is an aberrant cardiac afterpotential that underlies the development of life-threatening ventricular arrhythmias. It is believed that the development of EAD is caused by the reactivation of L-type Ca2+ current during the period of the action potential plateau; however, the cellular mechanisms that underlie the development of EAD is still controversial. One favorable alternative is the depolarizing reverse-mode operation of the Na+/Ca2+ exchanger, which is activated by aberrant Ca2+ release from the sarcoplasmic reticulum in the process of reverse E–C coupling. Since EADs develop preferentially in damaged heart cells with abnormal Ca2+-signaling, here I studied the causal link between the development of EADs and aberrant intracellular Ca2+ level ([Ca2+]i) dynamics in mouse heart cells using the whole-cell clamp technique. My results show (1) the generation of EADs was preceded by the development of depolarizing membrane potential (Vm) fluctuation, (2) the depolarizing Vm fluctuation is associated with [Ca2+]i elevation, suggesting an involvement of reverse E–C coupling via the Na+/Ca2+ exchanger, and (3) that extending the T-tubules’ length constant by decreasing the extracellular K+ level facilitated the development of the Vm fluctuation and EADs. Taken together, I conclude that EADs are caused by the depolarizing Vm fluctuation, which is induced locally in the T-tubule membrane by aberrant [Ca2+]i elevation and is conducted back electrotonically along the T-tubules.
SERCA2a gain of function in patient-derived R14Del hiPSC-CMs
Authors: Badone Beatrice , Ronchi Carlotta , Lodola Francesco , Maniezzi Claudia , Eskandr Marem , Florindi Chiara , Knaust Anika E. , Eschenhagen Thomas , Hansen Arne , Zaza Antonio
Published: November 2021

Phospholamban (PLN) is the natural inhibitor of the sarco/endoplasmic reticulum Ca2+ ATPase (SERCA2a). Heterozygous PLN-R14del mutation is associated with an arrhythmogenic dilated cardiomyopathy (DCM), whose pathogenesis has been attributed to SERCA2a “superinhibition.” The aim of the project is to test in human induced pluripotent stem cell–derived cardiomyocytes (hiPSC-CM) harvested from a PLN-R14del carrier whether (1) Ca2+ dynamics and protein localization were compatible with SERCA2a superinhibition and (2) functional abnormalities could be reverted by pharmacological SERCA2a activation with PST3093. Ca2+ transients (CaT) were recorded at 36°C in hiPSC-CMs clusters during field stimulation. SERCA2a and PLN were immunolabeled in single hiPSC-CMs. Mutant (MUT) preparations were compared with isogenic WT ones obtained by mutation reversal. WT and MUT differed for the following properties: (1) CaT time to peak (tpeak) and half-time of CaT decay were shorter in MUT, (2) several CaT profiles were identified in WT, whereas “hyperdynamic” ones largely prevailed in MUT, (3) whereas tpeak rate-dependently declined in WT, it was shorter and rate independent in MUT, and (4) diastolic Ca2+ rate-dependently accumulated in WT, but not in MUT. When applied to WT, PST3093 changed all of the above properties to resemble those of MUT; when applied to MUT, PST3093 had no effect. Preferential perinuclear SERCA2a-PLN localization was lost in MUT hiPSC-CMs. In conclusion, functional data converge to argue for PLN-R14del incompetence in inhibiting SERCA2a in the tested case, thus weakening the rationale for therapeutic SERCA2a activation. Mechanisms alternative to SERCA2a superinhibition should be considered in the pathogenesis of DCM, including dysregulation of Ca2+-dependent transcription.
Discovery of new intracellular junctions: The calcium entry units (CEUs)
Authors: Boncompagni Simona
Published: November 2021

In 2017, Boncompagni, Michelucci et al. demonstrated that during exercise the sarcotubular system of extensor digitorum longus (EDL) fibers undergoes a profound remodeling that leads to the assembly of new junctions between T-tubule extensions at the I band and sarcoplasmic reticulum (SR) stacks. As these junctions contain colocalized STIM1 and Orai1 and enhance store-operated Ca2+ entry (SOCE), they have been named Ca2+ entry units (CEUs). In addition, it has been more recently shown that (1) CEUs disassemble following recovery, with T-tubules retraction from the I band faster than SR stacks disassembly, and (2) lack of calsequestrin-1 (CASQ1) induces a constitutive assembly of CEUs, resulting in enhanced SOCE that counteracts the SR Ca2+ depletion. We have now analyzed (1) CEUs during postnatal maturation (at 2 wk of age) and (2) whether CEUs form in slow-twitch fibers (soleus). (a) Compared with adult (4 mo) EDL fibers of resting WT mice, at 2 wk of age we found a greater longitudinal disposition of T-tubules associated to SR membranes forming junctions virtually identical to CEUs in adult EDLs of exercised WT mice, which promote increased STIM1/Orai1-mediated SOCE. (b) We also compared structure and function of soleus (which also express the cardiac isoform CASQ2) from WT mice and from mice lacking either CASQ1 (CASQ1-null) or CASQ1/2 (dCASQ-null). In soleus from both genotypes, CEUs are constitutively assembled although they appear structurally smaller than those described previously in exercised WT or CASQ1-null EDLs. A detailed EM quantitative analysis revealed that CEUs were more abundant in dCASQ-null than CASQ1-null mice. The amount of CEUs strictly correlated with the ability of soleus fibers to recover extracellular Ca2+ via SOCE to support contractility during high-frequency stimulation. These data were supported by molecular analysis of Western blots, showing that Orai1 expression was enhanced following ablation of CASQ.
RYR1-related myopathies: Expanding the spectrum of morphological presentation
Authors: Sorrentino Vincenzo
Published: November 2021

Mutations in the RYR1 gene are the most common cause of nondystrophic congenital myopathies. Mutations in RYR1 were initially identified in individuals susceptible to malignant hyperthermia, a pharmacogenetic disorder triggered by volatile anesthetics and succinylcholine. Shortly after, mutations in RYR1 were identified in patients with central core disease, which is the most frequent congenital myopathy, and in other muscle disorders, collectively referred to as RYR1-related myopathies. RYR1 mutations are also responsible of some acute pathological conditions triggered by heat- and exercise-induced stress, named exertional heat stroke and exertional-induced rhabdomyolysis, which, similarly to malignant hyperthermia, occur in otherwise healthy individuals with normal skeletal muscle functions. Hundreds of causative mutations linked to RYR1-related diseases have been identified. These mutations are clustered in three regions that are referred to as the N-terminal, central, and C-terminal hot spots. Recent developments in cryo-EM techniques have provided high-resolution reconstructions of the channel, allowing a much better definition of the structural domains within the large N-terminal cytoplasmic region and in the C-terminal domain containing six transmembrane helices and the pore region of the channel. RYR1 mutations may either activate or inhibit channel function or, in some cases, can reduce the expression levels of RYR1 protein. However, similar clinical phenotypes can result from mutations with opposing effects on RYR1 function, or little or no correlation can be found between the observed clinical phenotype and localization of mutations in the structural domains of the RYR1 channel, even though recent studies indicate that clinically severe cases are mostly recessive or due to mutations located in the bridging solenoid. Recent results on the identification of RYR1 mutations in patients with myopathies will be presented.
Cardiac muscle disease and therapeutic targets
Authors: Schuldt Maike , Dorsch Larissa , Kuster Diederik , Van der Velden Jolanda
Published: November 2021

Hypertrophic cardiomyopathy (HCM) is the most common genetic heart disease. While ∼50% of patients with HCM carry a sarcomere gene mutation (sarcomere mutation-positive, SMP), the genetic background is unknown in the other half of the patients (sarcomere mutation-negative, SMN). Gene mutations are most often present in genes encoding the sarcomere proteins myosin heavy chain, myosin-binding protein C, and troponin T. Studies in cardiac tissue samples from patients with obstructive HCM that were obtained during myectomy surgery showed increased myofilament calcium sensitivity, increased kinetics and tension cost, and a reduction of the super-relaxed state of myosin, which is associated with an energy-conserving status of the crossbridges. The increase in myofilament calcium sensitivity is observed at a low dose of mutant protein, while the magnitude of the increase in calcium sensitivity depends on the specific mutation location. These mutation-mediated myofilament changes may underlie inefficient in vivo cardiac performance in mutation carriers. Reduced cardiac efficiency has been observed before onset of cardiac hypertrophy and at advanced disease stages. In addition, impaired diastolic function is an early disease characteristic of HCM. Our recent proteomics studies revealed increased detyrosination of microtubules, which may be a cause of diastolic dysfunction. Recent treatments that target inefficient cardiac performance, such as myosin inhibitors and metabolic drug therapies, may have the potential to prevent, delay, or even reverse disease in HCM-mutation carriers. Treatment response may depend on the specific gene mutation in SMP individuals and may explain diverse response of HCM patients to therapy. While mutation-mediated cardiomyocyte defects have become clear in past years, more research is warranted to define the cellular pathomechanisms of cardiac dysfunction in SMN patients.
Implication of CREB in the calcium regulation by ischemia/reperfusion in cardiomyocytes
Authors: Falcón Débora , Mayoral Isabel , Ordóñez Antonio , Smani Tarik
Published: November 2021

It is well established that abnormalities in [Ca2+] regulation occur in heart diseases. Actually, independent studies demonstrated that Orai1/2/3 and TRPC protein related with store-operated calcium channels (SOCC) have a role in cardiac pathologies. Ischemia/reperfusion (I/R) stimulates transcription factor activation that modifies the expression of genes implicated in the pathogenesis of this process. Previous results described an increase in the expression of Orai1 and TRPC5 in cardiomyocytes after I/R, although the molecular mechanisms that mediate this regulation are still unknown. The aim of this study is to examine the molecular mechanisms implicated in the regulation of SOCC in cardiomyocytes after I/R focusing on the handling of intracellular [Ca2+]. Experiments were performed in a rat model of myocardial I/R, in adult (ARVM) and neonatal rat ventricular myocytes (NRVM), and in ventricular samples of heart-failure patients. Immunofluorescence was used to investigate CREB activation, and the protein expression was analyzed by Western blot. Calcium diastolic studies were realized using microfluorimetric technic with FURA-2AM. To evoke intracellular Ca2+ transients, ARVMs were field stimulated at 0.5 Hz and NRVMs at 1 Hz. An activation of CREB after I/R was observed in adult and neonatal rat cardiomyocytes. Furthermore, it was demonstrated that this activation was mediated by PKA, but not for EPAC2 or ERK. I/R induced an CREB-dependent ORAI protein expression increase and also an increase in the diastolic calcium in NRVM and ARVM from I/R animal models. Additionally, it was observed that ORAI1 inhibition with SYNTA-66 or GSK reduced the calcium diastolic increase induced by I/R. We demonstrated, for the first time, the activation of the transcription factor CREB in cardiomyocytes after I/R. This activation induces an up-regulation of ORAI1, suggesting that this channel plays a role in the I/R induced calcium diastolic increase.
Generative adversarial network and transfer-learning-based fault detection for rotating machinery with imbalanced data condition
Authors: Li Jun , Liu Yongbao , Li Qijie
Published: November 2021

Intelligent fault diagnosis achieves tremendous success in machine fault diagnosis because of its outstanding data-driven capability. However, the severely imbalanced dataset in practical scenarios of industrial rotating machinery is still a big challenge for the development of intelligent fault diagnosis methods. In this paper, we solve this issue by constructing a novel deep learning model incorporated with a transfer learning (TL) method based on the time-generative adversarial network (Time-GAN) and efficient-net models. Firstly, the proposed model, called Time-GAN-TL, extends the imbalanced fault diagnosis of rolling bearings using time-series GAN. Secondly, balanced vibration signals are converted into two-dimensional images for training and classification by implementing the efficient-net into the transfer learning method. Finally, the proposed method is validated using two types of rolling bearing experimental data. The high-precision diagnosis results of the transfer learning experiments and the comparison with other representative fault diagnosis classification methods reveal the efficiency, reliability, and generalization performance of the presented model.
Enhanced terahertz emission from mushroom-shaped InAs nanowire network induced by linear and nonlinear optical effects
Authors: Xi Fugang , Yang He , Khayrudinov Vladislav , He Yuhang , Haggren Tuomas , Zhou Yixuan , Lipsanen Harri , Sun Zhipei , Xu Xinlong
Published: November 2021

The development of powerful terahertz (THz) emitters is the cornerstone for future THz applications, such as communication, medical biology, non-destructive inspection, and scientific research. Here, we report the THz emission properties and mechanisms of mushroom-shaped InAs nanowire (NW) network using linearly polarized laser excitation. By investigating the dependence of THz signal to the incidence pump light properties (e.g. incident angle, direction, fluence, and polarization angle), we conclude that the THz wave emission from the InAs NW network is induced by the combination of linear and nonlinear optical effects. The former is a transient photocurrent accelerated by the photo-Dember field, while the latter is related to the resonant optical rectification effect. Moreover, the p-polarized THz wave emission component is governed by the linear optical effect with a proportion of ∼85% and the nonlinear optical effect of ∼15%. In comparison, the s-polarized THz wave emission component is mainly decided by the nonlinear optical effect. The THz emission is speculated to be enhanced by the localized surface plasmon resonance absorption of the In droplets on top of the NWs. This work verifies the nonlinear optical mechanism in the THz generation of semiconductor NWs and provides an enlightening reference for the structural design of powerful and flexible THz surface and interface emitters in transmission geometry.
Exploring electron beam induced atomic assembly via reinforcement learning in a molecular dynamics environment
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Authors: Vasudevan Rama K , Ghosh Ayana , Ziatdinov Maxim , Kalinin Sergei V
Published: November 2021

Atom-by-atom assembly of functional materials and devices is perceived as one of the ultimate targets of nanotechnology. Recently it has been shown that the beam of a scanning transmission electron microscope can be used for targeted manipulation of individual atoms. However, the process is highly dynamic in nature rendering control difficult. One possible solution is to instead train artificial agents to perform the atomic manipulation in an automated manner without need for human intervention. As a first step to realizing this goal, we explore how artificial agents can be trained for atomic manipulation in a simplified molecular dynamics environment of graphene with Si dopants, using reinforcement learning. We find that it is possible to engineer the reward function of the agent in such a way as to encourage formation of local clusters of dopants under different constraints. This study shows the potential for reinforcement learning in nanoscale fabrication, and crucially, that the dynamics learned by agents encode specific elements of important physics that can be learned.
Effects of secondary γ-electrons from accelerator grid under ion impingement in gridded ion sources
Authors: Fu S H , Tian L C , Ding Z F
Published: November 2021

Thus far, effects of secondary γ-electrons emitted from accelerator grids (AGs) of gridded ion sources on ionization in discharge chambers have not been studied. The presence and induced processes of such secondary electrons in a microwave electron cyclotron resonance gridded ion source are confirmed by the consistent explanations of: (1) the observed jump of ion beam current (I
b) in case of a low-density plasma appearing at the chamber’s radial center due to the microwave skin effect; (2) the evolution of glow images recorded from the end-view of the ion source during the jump of I
b; (3) the over-large jump step of I
b with increasing microwave power; (4) the pattern appearing on the temperature sticker exposed to the discharge operated in the regime where the arrayed energetic-electron beamlets are injected into the discharge chamber; (5) the measured step-increment in the voltage drop across the screen grid (SG) sheath. A positive feedback loop composed of involved processes is established to elucidate the underlying mechanism. Energetic γ-electrons from the AG and warm δ-electrons from the opposite antenna do not produce direct excitation and ionization, but they enhance the electrical confinement of cold electrons by elevating the voltage drop across the sheaths at the antenna and SG, thus leading to the jump of I
b. The energetic γ-electrons-based model can be also modified to explain abnormal results observed in the other gridded ion sources. Energetic γ-electrons from AGs should be taken into account in understanding gridded ion sources.
Manipulation of wave motion in smart nonlinear phononic crystals made of shape memory alloys
Authors: Sepehri Soroush , Mosavi Mashhadi Mahmoud , Seyyed Fakhrabadi Mir Masoud
Published: November 2021

Thanks to the functional role of shape memory alloys (SMAs) in controlling the mechanical behavior of structures, researchers have started investigating the possibility of manipulating wave motion in phononic crystals using SMAs. While SMAs were used before to tune the wave propagation in linear phononic crystals, in this work, we aim to extend their utilization to nonlinear lattices. For this purpose, SMA helical springs are used to manipulate the dispersion curves and the location of stop-bands in weakly nonlinear monoatomic and diatomic lattice chains. Using Brinson’s formulation to describe the thermo-mechanical behavior of SMA wires and Lindstedt-Poincaré method to solve the derived governing equations, closed-form nonlinear dispersion relations in monoatomic and diatomic lattice chains are obtained and the effects of temperature-induced phase transformation and stiffness nonlinearity on the wave propagation are investigated. The results reveal that the dispersion curves of a weakly nonlinear monoatomic chain are formed at lower frequencies through the austenite-to-martensite phase transformation. Similarly, both the acoustic and optical branches of a diatomic lattice are moved to lower frequencies during the phase transformation in the cooling process. Therefore, the generated stop-bands in nonlinear diatomic lattices are also moved to lower frequencies. In addition, using auxiliary SMA ground springs, new classes of nonlinear monoatomic and diatomic chains exhibiting additional low-frequency attenuation zones are introduced. These low-frequency stop-bands are tunable and their frequency range can be modulated by exploiting the temperature-induced phase transformation in the SMA springs. The results obtained from analytic formulations are verified by numerical calculations and an excellent agreement is observed. Such tunability and the potential for adding stop-bands in low frequencies reveal that SMAs can be very helpful in designing nonlinear phononic and acoustic devices, such as vibration mitigators and wave filters with pre-defined attenuation zones.
Unified galaxy power spectrum measurements from 6dFGS, BOSS, and eBOSS
Authors: Beutler Florian , McDonald Patrick
Published: November 2021

We make use of recent developments in the analysis of galaxy
redshift surveys to present an easy to use matrix-based analysis
framework for the galaxy power spectrum multipoles, including
wide-angle effects and the survey window function. We employ this
framework to derive the deconvolved power spectrum multipoles of
6dFGS DR3, BOSS DR12 and the eBOSS DR16 quasar sample. As an
alternative to the standard analysis, the deconvolved power spectrum
multipoles can be used to perform a data analysis agnostic of survey
specific aspects, like the window function. We show that in the
case of the BOSS dataset, the Baryon Acoustic Oscillation (BAO)
analysis using the deconvolved power spectra results in the same
likelihood as the standard analysis. To facilitate the analysis
based on both the convolved and deconvolved power spectrum
measurements, we provide the window function matrices, wide-angle
matrices, covariance matrices and the power spectrum multipole
measurements for the datasets mentioned above. Together with this
paper we publish a Python-based toolbox to calculate the
different analysis components. The appendix contains a detailed
user guide with examples for how a cosmological analysis of these
datasets could be implemented. We hope that our work makes the
analysis of galaxy survey datasets more accessible to the wider
cosmology community.
Proximate Analysis and Antioxidant Activity of Red Rice (Oryza sativa L.) Milk
Authors: Wijaya Cokro , Romulo Andreas
Published: November 2021

Plant-based milk has become a consumer interest in recent years due to the health-beneficial effect of the product. Red rice milk is one of the cereal-based milk that uses red rice (Oryza sativa L.) as the main ingredient that contains antioxidant activity. The utilization of red rice in Indonesia is very limited, only for replacing white rice. The potency of red rice to be developed as rice milk has been poorly studied about the antioxidant activity and proximate content in the red rice milk. In this research, red rice was used as the main ingredient. Proximate analysis and antioxidant analysis (DPPH and total phenolic content) were conducted on the red rice milk. This research aims to analyze the nutrients content in red rice milk and its antioxidant activity. Red rice milk contained 98.01% of water, 0.07% of ash, 0.13% of protein, 0.71% of fat, and 1.07% of carbohydrate. Red rice milk inhibited 53.37% of DPPH radical and contained total phenolic about 274.5 ppm. The result revealed the potential of red rice milk as a functional drink with antioxidants.
Simple Amperometric Biosensor for Sucrose Concentration Measurement Based on Principal Component Analysis
Authors: Rosandi Vira Annisa , Linda Tetty Marta , Agustirandi Beny , Umar Lazuardi
Published: November 2021

Sucrose is a type of sugar that is widely used in various types of foods and beverages. In Indonesia, sucrose consumption reaches 2.8 million tons on average per year. Effects of consuming too much sucrose can increase the risk of various diseases such as diabetes, dental caries and obesity. The level of maximum amount of sucrose that is safe for the body equal to 10% of the total energy or the equivalent of 50 g/person/day, so that the required detection system and the identification of the sucrose concentration. In this work, the identification process was carried out using an amperometric biosensor based on the yeast Saccharomyces cerevisiae as a bioreceptor. Measurements were made by immobilizing yeast cells and analyte samples into the biosensor electrodes and observed based on cellular respiration activity which was expressed as a parameter of dissolved oxygen (DO). The biosensor response is generated in the form of an output potential value, then processed using principal component analysis (PCA) to produce a sucrose concentration classification point with a percentage of variance of the two main components of 98.77% which states that the sensor is able to identify sucrose concentrations.
High Potential of Averrhoa bilimbi Leaf Waste as Porous Activated Carbon Source for Sustainable Electrode Material Supercapacitor
Authors: Taer E , Nursyafni  , Apriwandi  , Taslim R
Published: November 2021

The energy cost-effective/free-environmental pollution concerns have an interest in bio-waste materials for the production of porous activated carbon, especially as electrode material for electrochemical energy storage devices such as li-ion batteries and supercapacitors. In this study, Averrhoa bilimbi leaf wastes were selected as a porous activated carbon source for sustainable electrode material supercapacitor. Porous activated carbons were prepared by chemical activation of 0.5 ml−1 sodium hydroxide solution at an optimum temperature of 800 °C pyrolyze in an environment of N2 and CO2 gases. The monolith coin shape of activated carbon is maintained by optimizing the self-adhesive properties of the precursor without the addition of adhesive materials. All coin monoliths feature a turbostratic to highly amorphous carbon structure. Furthermore, the relatively high monolith dimensional shrinkage of 42.00% initiated the development of a better pore framework carbon. In symmetric supercapacitors, electrochemical behavior confirmed a high specific capacitance of 149.04 F/g at a constant density of 1.0 A/g. Moreover, the maximum energy density was found of 10.50 Whkg−1 at an optimum power density of 116.35 W/kg in an aqueous electrolyte of 1 ml−1 Na2SO4. With bio-recycled waste, relatively easy preparation, and high electrochemical properties, porous activated carbon based on Averrhoa bilimbi leaf has great potential as a sustainable electrode material for supercapacitor energy storage applications.
Etlingera elatior leaf agricultural waste as activated carbon monolith for supercapacitor electrodes
Authors: Taer E , Padang E , Yanti N , Apriwandi  , Taslim R
Published: November 2021

Recently, biomass waste has become the focus of several researchers because it has promising potential when processed into porous activated carbon. Abundant availability, uncomplicated processing, and more economical are the reasons for choosing biomass as the basic material for making carbon electrodes for electric energy storage supercapacitors. In this study, Etlingera elatior waste biomass is processed into activated carbon by heating at high temperature and impregnation of 0.5 M ZnCl2. The monolith sample was optimized through a single-stage integrated high-temperature pyrolysis process. Where the process of carbonization of N2 gas from a temperature of 30 °C to 600 °C followed by a physical activation process of CO2 gas to a temperature of 800 °C. Determination of the physical properties of the electrodes through density characterization, while the electrochemical properties were analyzed by cyclic voltammetry and galvanostatic charge discharge methods. Cyclic voltammetry and galvanostatic charge discharge analysis were performed with 1 M Na2SO4 aqueous electrolyte at a voltage of 0–1 V and a scan rate of 1 mV/s. Furthermore, the high electrochemical behavior of the CV method was found to be 108 F/g, while for the gcd method, the specific capacitance was much higher at 148 F/g at a constant current density of 1.0 A/g. Further calculations found an energy density of 8.23 Wh/kg and a power density of 161 W/kg. These results support the optimization of 0.5 M ZnCl2 impregnated Etlingera elatior leaves as the base material for activated carbon electrodes to increase the supercapacitor capacitance.
Methodological approach to the tensiometrical analysis of the blood serum samples of Duroc pigs
Authors: Belopukhov S L , Zaitsev S Yu
Published: November 2021

The aim of this work was to compare the dynamic surface tension (DST) with biochemical parameters of the blood serum of Duroc pigs (BSDP). BSDP samples were taken after various times of pig fattening: 65 days (Group 1), 72 days (Group 2), 84-89 days (Group 3), 91-100 days (Group 4). Our approach is consisting in the BSDP-DST-measurement using all four modes of BPA-tensiometer: M1) “Standard experiment”; M2) “Experiment at constant lifetime”; M3) “Accelerated experiment”; M4) “Quick scan”. Here, we have worked out all the modes mentioned above for determining the BSDP tensiometric parameters. The BSDP-DST parameters obtained for groups 3 and 4 (84-89 and 91-101 fattening days, respectively) were very high and close in numbers. (from 73.4-74.6 mN/m for STo, to 58.1-60.5 mN/m for STm, respectively). These BSDP-DST parameters were significantly higher (7-13%) at extremely low interface “life-times” (0.01-0.1 s), as compared to those for groups 1 and 2 (65 and 72 fattening days, respectively). In contrast, the BSDP-DST parameters obtained for groups 1 and 2 were low (from 66.1-71.4 mN/m for STo, to 56.9-57.9 mN/m for STm, respectively). These data (in combination with other physical-chemical methods) can be used for the fundamental data set and monitoring the pig growth, health, productivity, etc.
3-adic complexity of ternary generalized cyclotomic sequences with period
Authors: Edemskiy V A , Koltsova S A
Published: November 2021

In this paper, we study the ternary generalized cyclotomic sequences with a period equal to a power of an odd prime. Ding-Helleseth’s generalized cyclotomic classes of order three are used for the definition of these sequences. We derive the symmetric 3-adic complexity of above mention sequences and obtain the estimate of symmetric 3-adic complexity of sequences. It is shown that 3-adic complexity of these sequences is large enough to resist the attack of the rational approximation algorithm for feedback with carry shift registers.
Ranking of documents of topical corpus according to their mutual relevance in the problem of estimating of affinity of a text to the sense standard
Authors: Mikhaylov D V , Emelyanov G M
Published: November 2021

The offered paper is devoted to the problem of oneness and integrity of image for the semantic pattern (i.e., sense standard) revealed phrase by phrase for some text within a topical collection. One phrase corresponds here to an extended natural-language sentence. The basis of estimating affinity to the standard is the classifying of words of each phrase in a text according to the TF-IDF value relative to some text corpus. Texts to the corpus are pre-selected by an expert. The essence of the problem: for each phrase, its maximal affinity to the sense standard is achieved concerning the individual corpus document, and, consequently, it is necessary to estimate the mutual relevance of such documents concerning different phrases of the analyzed text. Based on distances between vectors of TF-IDF for words of a separate phrase obtained relative to different corpus documents, the significance estimation for each such document is entered into consideration to choose a pair of mutual relevant.
Research of control algorithm of traction drive of a mining dump truck using simulation models of motion
Authors: Muravyev A S , Shishkina V A , Buzunov N V , Kartashov A B , Dubinkin D M , Nozirzoda Sh.
Published: November 2021

The paper describes control algorithms for a combined power plant made according to a sequential scheme for a 6x6 mining dump truck. The general approaches used in the development of control systems for similar power plants and transmissions are described. The methods of testing and simulation mathematical models used to analyze the operation of control systems for combined power plants are presented. As an example of control systems, the architecture of the developed system used for a mining dump truck is given. The developed control system and simulation model make it possible to analyze the behavior of the traction motor, energy storage device, transmission elements, and operational properties.