Extreme States Research Articles

A Platform for Ultra-Fast Proton Probing of Matter in Extreme Conditions.

Recent developments in ultrashort and intense laser systems have enabled the generation of short and brilliant proton sources, which are valuable for studying plasmas under extreme conditions in high-energy-density physics. However, developing sensors for the energy selection, focusing, transport, and detection of these sources remains challenging. This work presents a novel and simple design for an isochronous magnetic selector capable of angular and energy selection of proton sources, significantly reducing temporal spread compared to the current state of the art. The isochronous selector separates the beam based on ion energy, making it a potential component in new energy spectrum sensors for ions. Analytical estimations and Monte Carlo simulations validate the proposed configuration. Due to its low temporal spread, this selector is also useful for studying extreme states of matter, such as proton stopping power in warm dense matter, where short plasma stagnation time (<100 ps) is a critical factor. The proposed selector can also be employed at higher proton energies, achieving final time spreads of a few picoseconds. This has important implications for sensing technologies in the study of coherent energy deposition in biology and medical physics.

Restoration of the upper limbs of athletes in the Caucasian Mineral Waters resort using the combined application of electro- and peloidotherapy to the cervical– collar area

Objective. Of the work was to develop a method for restoring the upper limbs of athletes in the Caucasian Mineral Waters resort based on the combined use of electro- and peloid therapy on the cervical-collar area. Material and methods.Was carried out among highly qualified athletes during their stay at training camps in Kislovodsk. 30 athletes took part in the study (23 athletes — the main group and 7 athletes (CG). Before and after the application of the technique, the athletes were examined: the initial level and dynamics of the functional state of the upper extremities (according to electroneuromyography (ENMG) and rheography), as well as hemodynamics of cerebral vessels (according to rheoencephalography). The results of the study showed that a single and course application of electro- and peloid therapy procedures on the cervical-collar area contributes to a significant relaxing effect on the upper limbs of athletes. As a result, a decrease in neuromuscular activity and normalization of excessively increased blood flow, improvement of venous outflow. Conclusion. A method for restoring the upper extremities of athletes has been developed and scientifically substantiated, which is recommended for use especially for relaxation after a training day and during the transition (recovery) period of the training process in sanatorium-resort conditions.

Wind-Sea and Swell Climate in the Black and Azov Seas, Based on 42-Year Spectral Wave Hindcast

Long-term wave climates of the Black and Azov Seas are widely assessed based on the bulk wave parameters of the mixed sea. However, studies based on spectral wave partitions are rarely documented. Assessment of the wave climate based on the individual wave systems provides a more reliable description of the sea states' characteristics and the variability in the long-term wave climate. For instance, the wind-sea climate may reflect a real change in the local climate. However, local change in swell characteristics may not necessarily reflect a change in the local climate, and it can locally influence the mixed sea climate variability. This study assessed the spatial distributions of the long-term averages and maxima of mixed seas, wind-sea, and swell partitions at annual and seasonal scales. The contributions of wind-sea and swell partitions to the mixed-sea were computed, and their spatial and temporal variability was also assessed for overall and extreme sea state conditions. Finally, the occurrence in main wave systems' directions and occurrence of crossing, opposing, and following wind-sea and swell interactions were computed. The wind-sea contribution to the mixed-sea exceeds 70 % in all Black Sea and >95 % in the Azov Sea. The swells are more dominant on the Northeastern and Northwestern Black Sea basins. Thus, the results show spatial and temporal variability in the wind-sea climate close to the mixed sea but largely different compared to the swell climate. The inter-annual trends in the swell partitions and wind-sea are inversed at some locations.

A new active rehabilitation training mode for upper limbs based on Tai Chi Pushing Hands

Robot-assisted rehabilitation is a crucial approach to restoring motor function in the limb. However, the current training trajectory lacks sufficient theoretical or practical support, and the monotony of single-mode training is a concern. Tai Chi Pushing Hands, a beneficial and effective daily exercise, has been shown to improve balance function, psychological state, and motor function of the upper extremities in patients recovering from stroke. To address these issues, we propose a new active rehabilitation training that incorporates Tai Chi Pushing Hands movements and yin-yang balance principles. The training trajectory and direction are encoded by the velocity field and consist of two processes: yang (push) and yin (return). During yang, the limb actively pushes the robot to move, while during yin, the limb actively follows the robot’s movement. To provide necessary assistance, an admittance controller with self-adaptive parameters is designed. In addition, we introduce two indexes, the ‘Intention Angle’ (ϖ) and the time ratio (Γ), to evaluate motion perception performance. Our experiment was conducted on a 4-degree-of-freedom upper limb rehabilitation robot platform, and the subjects were separated into a familiar group and an unfamiliar group. The experiment results show that the training could be completed well no matter whether the subject is familiar with Tai Chi Pushing Hands or not. The parameters and the movement of the robot can be adjusted based on the interactive force to adapt to the ability of the subject.

How Algorithms Promote Self-Radicalization: Audit of TikTok’s Algorithm Using a Reverse Engineering Method

Algorithmic radicalization is the idea that algorithms used by social media platforms push people down digital “rabbit holes” by framing personal online activity. Algorithms control what people see and when they see it and learn from their past activities. As such, people gradually and subconsciously adopt the ideas presented to them by the rabbit hole down which they have been pushed. In this study, TikTok’s role in fostering radicalized ideology is examined to offer a critical analysis of the state of radicalism and extremism on platforms. This study conducted an algorithm audit of the role of radicalizing information in social media by examining how TikTok’s algorithms are being used to radicalize, polarize, and spread extremism and societal instability. The results revealed that the pathways through which users access far-right content are manifold and that a large portion of the content can be ascribed to platform recommendations through radicalization pipelines. Algorithms are not simple tools that offer personalized services but rather contributors to radicalism, societal violence, and polarization. Such personalization processes have been instrumental in how artificial intelligence (AI) has been deployed, designed, and used to the detrimental outcomes that it has generated. Thus, the generation and adoption of extreme content on TikTok are, by and large, not only a reflection of user inputs and interactions with the platform but also the platform’s ability to slot users into specific categories and reinforce their ideas.

Experimental study of a semi-submersible floating wind turbine with aquaculture cages under combined wind and irregular waves

The coordinated and integrated development of multiple marine industries is conducive to achieving efficient utilization of the ocean. Here, a novel semi-submersible floating wind power platform integrated with aquaculture cages is proposed. Then, model tests of the innovative floating wind-aquaculture platform (FWAP) with scaling ratio of 1/40 are carried out. Four sea conditions (below rated, rated, cut out and 50-year sea states) and three incident angles of combined wind and waves (0 deg, 90 deg and 180 deg) are considered in the tests. Correspondingly, three typical motion responses of the FWAP, the acceleration response of the wind turbine and the representative mooring line tension are analyzed. The experimental results show that one obvious response peak is mainly found in the response amplitude operator (RAO) curves for the in-plane motion of the new FWAP, including surge, sway and yaw. While for out-of-plane motions including heave, roll and pitch, the RAO curves show two distinct response peaks. Notably, as the environmental conditions progress from below rated to rated, cut out, and finally to 50-year extreme sea state, the motion response of the FWAP becomes increasingly pronounced. Furthermore, the acceleration of the wind turbine under rated and cut out conditions is significantly large, which can be attributed to the effect of rotor rotation. While the maximum mooring line tension in the FWAP is observed at the 50-year sea state, the maximum average tension occurs at the rated condition. The response power spectra of the new FWAP reveal the presence of multiple frequency components. Additionally, the nets can act as an excited or damping effect on the motion of the FWAP, the acceleration of the wind turbine and the mooring line system, depending on the variation of the sea conditions or the incident angle. This study can provide reference for the design improvement and engineering application of such new FWAP.

Prioritizing Indicators for Rapid Response in Global Health Security: A Bayesian Network Approach

This study explored a Bayesian belief networks (BBNs) approach, developing two distinct models for prioritizing the seven indicators related to the “rapid response to and mitigation of the spread of an epidemic” category within the context of both the specific category and the Global Health Security Index (GHS index). Utilizing data from the 2021 GHS index, the methodology involves rigorous preprocessing, the application of the augmented naive Bayes algorithm for structural learning, and k-fold cross-validation. Key findings show unique perspectives in both BBN models. In the mutual value of information analysis, “linking public health and security authorities” emerged as the key predictor for the “rapid response to and mitigation of the spread of an epidemic” category, while “emergency preparedness and response planning” assumed precedence for the GHS index. Sensitivity analysis highlighted the critical role of “emergency preparedness and response planning” and “linking public health and security authorities” in extreme performance states, with “access to communications infrastructure” and “trade and travel restrictions” exhibiting varied significance. The BBN models exhibit high predictive accuracy, achieving 83.3% and 82.3% accuracy for extreme states in “rapid response to and mitigation of the spread of an epidemic” and the GHS index, respectively. This study contributes to the literature on GHS by modeling the dependencies among various indicators of the rapid response dimension of the GHS index and highlighting their relative importance based on the mutual value of information and sensitivity analyses.

Risk spillovers among global oil & gas firms

ABSTRACT This study examines the risk spillovers among the world’s top oil & gas firms, accounting for the role of environmental fiscal policies, economic policy uncertainty (EPU), and regulatory quality. We find evidence of high risk spillovers among the oil & gas firms, being more intense at the extreme market states. More highly capitalised firms are mostly net transmitters of spillovers across the different market states, but less so at the extreme market states. Net pair-wisely, the network analysis suggests that spillovers are trivial when the market is normal, but complex when it is bullish. Finally, the spillovers are driven by environmental tax and expenditures, EPU, and regulatory quality heterogeneously. These results have important implications for suitable investment decisions and policy-making.

Diffusion on PCA-UMAP Manifold: The Impact of Data Structure Preservation to Denoise High-Dimensional Single-Cell RNA Sequencing Data.

Single-cell transcriptomics (scRNA-seq) is revolutionizing biological research, yet it faces challenges such as inefficient transcript capture and noise. To address these challenges, methods like neighbor averaging or graph diffusion are used. These methods often rely on k-nearest neighbor graphs from low-dimensional manifolds. However, scRNA-seq data suffer from the 'curse of dimensionality', leading to the over-smoothing of data when using imputation methods. To overcome this, sc-PHENIX employs a PCA-UMAP diffusion method, which enhances the preservation of data structures and allows for a refined use of PCA dimensions and diffusion parameters (e.g., k-nearest neighbors, exponentiation of the Markov matrix) to minimize noise introduction. This approach enables a more accurate construction of the exponentiated Markov matrix (cell neighborhood graph), surpassing methods like MAGIC. sc-PHENIX significantly mitigates over-smoothing, as validated through various scRNA-seq datasets, demonstrating improved cell phenotype representation. Applied to a multicellular tumor spheroid dataset, sc-PHENIX identified known extreme phenotype states, showcasing its effectiveness. sc-PHENIX is open-source and available for use and modification.

Calibration of CFOSAT Off‐Nadir SWIM SWH Product Based on CNN‐LSTM Model

AbstractHigh‐precision observation of significant wave height (SWH) is crucial for marine research. The Surface Waves Investigation and Monitoring (SWIM) aboard the China France Oceanography Satellite (CFOSAT) provides the ocean wave spectrum that allows for the calculation of the off‐nadir SWH parameters, but there exists a certain bias with the in‐situ SWH values. To improve the accuracy of the SWH calculation bias from the off‐nadir 6°, 8°, 10° wave spectra and the whole combined spectrum, this paper establishes a spatio‐temporal hybrid model that combines convolutional neural network (CNN) and long short‐term memory network (LSTM). Additionally, to further correct bias exhibited under high sea state, we introduce a bias correction module based on deep neural network (DNN) to adjust the SWIM off‐nadir SWH greater than 4 m. The experimental results demonstrate a significant enhancement in the accuracy of corrected SWIM off‐nadir SWH, and the best calibration result is 10° with 0.267 m root mean square error (RMSE), and 0.979 correlation coefficient (R) compared with the ERA5 value. We conducted a comprehensive study and analysis on the performance of the proposed model under different wave heights, extreme sea states, and wind and swell regions. Meanwhile, the buoy and altimeters are leveraged to render further evaluation the RMSE of the corrected SWH is less than 0.5 m.

Sound Presentation of the Silent History: Orature in Yvonne Vera’s The Stone Virgins

Abstract: In her novel The Stone Virgins , Zimbabwean author Yvonne Vera provides a model of orature writing by using sound in the interaction between literature and history as well as literature and politics. This essay will principally draw on the ideas of Kenyan author Ngugi Wa Thiong’o as well as Roland Barthes’ ideas about listening to analyze this effect. As a medium of oral tradition that carries traditional aesthetic and cultural values throughout the text, sound and its spatiotemporal framework establish an interpretative community among the author, the character, and the reader. In this community, silence—an extreme state of sound—and distorted sound highlight the individual memories of the suppressed people and form a contrast with the collective national memory that is put under the framework of the history of patriotism by official nationalist discourse. To reconstruct the suppressed history of the common people, Vera adopts the performance mechanism of orature by sound and thereby presents the inner monologue of the characters, which helps restore the subjectivity of the oppressed and sends out a call to the reader to participate in the reconstruction of a new history with the people as subjects. Vera’s sound presentation of the silenced Zimbabwean history is an important example of orature writing, showcasing a strong sense of historical responsibility among Zimbabwean writers and contributing to the formation of originality of African Europhone literature.

Redesigning the electric gun: Launching thick flyers to hypervelocity with high efficiency

To investigate pressure states as extreme as those involved in inertial confinement fusion using projectile-driven impact, the projectile must be both moving at hypervelocity and thick enough to introduce a shock pulse sufficiently long as to be measured. The electric gun is a highly efficient pulsed-power projectile launcher: its unique drive mechanism has been reported to convert over 25% of a capacitor bank’s stored electrical energy to flyer kinetic energy (Osher et al., 1990). This high efficiency allows the gun to accelerate thin dielectric flyers to hypervelocity using relatively low energy machines (Weingart et al., 1979). However, the technique was unable to accelerate thick flyers (>0.5 mm) without causing the flyers significant damage, rendering it unsuitable for investigating extreme states of matter. In this work, previously existing results from the launch of a thin flyer on a low energy machine were analysed using a 0D electric gun model (Fitzgerald et al., 2023). The pressure states experienced by the flyer during this shot, performed in a well understood region of the electric gun parameter space, were used to inform the design of a new electric gun load, capable of launching thick flyers to hypervelocity. The experimental results of the testing of this load design on a 140 kV, 2.0µs rise-time machine are presented. The load was found to successfully accelerate intact flyers up to 2.0-mm-thick, introducing shock speeds of over 10 km/s in a PMMA target block, inducing pressures of 80 GPa. This is twice as thick as those reported previously (Song et al., 2018). The outcomes of the study suggest the results from previous low-risk shots can be used to develop electric gun loads in new regions of the design space using simplified modelling tools.

Branching ratio in the photodissociation of (C6H5NH2)+-H2O–H218O

Molecular systems including clusters often manifest multiple photodissociation pathways upon absorption of photon energy enough to break down chemical bonds. This certainly raises fundamental questions to chemists: which pathway will be most favored and how can we predict it with precision? To address these issues, we had previously introduced a rather crude but highly simplified and straightforward calculation method, Rice-Ramsperger-Kassel-Marcus (RRKM) calculation method complemented by the concept of extreme loose transition state (eLTS). This approach has proven effective in estimating branching ratios in photodissociation of C6H4BrCl+. Here, we have extended this method to interpret results in IR photodissociation of (C6H5NH2)+-H2O–H218O for further evaluation and refinement of this method. We compared branching ratios derived from RRKM-eLTS with those obtained via phase-space theory (PST) to find that our calculation results through RRKM-eLTS were quite in line with the experimental data while those from PST calculation fluctuated significantly depending on the calculation levels and basis sets. This indicates that RRKM-eLTS model not only aligns well with experimental observations giving insights into the relevant rate constants but also intuitively explains these results. We, hereby, suggest that RRKM-eLTS model is a robust and user-friendly method for computing branching ratios, with possible applications to other molecular systems.

From prevention to response: A holistic exploration of factors shaping Global Health Security

In the face of global challenges, ensuring robust health security is paramount for safeguarding populations against emerging threats. Using country-level data on the Global Health Security (GHS) index covering 195 countries, this study employs Bayesian Belief Networks (BBNs) to explore probabilistic dependencies among various indicators that can influence health security outcomes. The findings reveal distinct probabilities of low performance for certain components within main indicators such as ‘prevention’, ‘early detection and reporting’, and ‘sufficient and robust health sector’, significantly shaping overall health security outcomes. Particularly noteworthy is the identification of ‘early detection and reporting’ as the most critical indicator, showing an 87% probability improvement, followed closely by ‘prevention’ at 81%. The latter part of the study delves into the sub-indicators associated with ‘early detection and reporting’. This analysis uncovers varying probabilities of extreme performance states, with ‘laboratory supply chains’ emerging as the most crucial sub-indicator, presenting an 84% probability improvement. Conversely, the ‘epidemiology workforce’ is deemed less influential in impacting overall health security outcomes. Assessing the mutual value of information sheds light on the informative nature of ‘prevention’ and ‘sufficient and robust health sector’ within the main indicators, while in sub-indicators, ‘surveillance data accessibility and transparency’ take precedence.

Structural optimization design of multi ribbed composite wall of building components under seismic load based on random optimization algorithm and resilience model

The multi ribbed composite wall structure is also known as the multi ribbed wall panel light frame structure. This structure is suitable for housing construction in the residential field. The special structural failure process and mode of multi ribbed composite walls are different from traditional walls. To fully utilize the excellent structural performance in building construction and improve the seismic performance of the building, based on the transformation principle of subset optimization algorithm for optimization problems, a constrained subset simulation optimization algorithm suitable for optimizing the maximum displacement angle of multi ribbed composite wall panels is designed. The Bayesian algorithm is used to construct a restoring force model for multi ribbed composite wall panels. The constrained subset simulation optimization algorithm and resilience model are used to optimize the seismic performance of 4-layer multi ribbed composite wall panels. The results show that the section height and the equivalent slant support width of the continuous column for the 4-story multi ribbed composite wall panel change from discrete distribution to aggregation with the increase of iteration. Finally, the sampling is stable in the 9th floor. At this time, the section height of the continuous column is 230 mm, and the equivalent slant support width is 525. After optimization, the failure probability of both extreme displacement angle states has decreased. When the peak ground acceleration is 1.0 g, the optimized second limit state failure probability is less than 100%. When the peak ground acceleration value is between 0.2 g and 0.6 g, both limit states show a rapid upward trend. The constrained subset simulation optimization algorithm and Bayesian quantitative resilience model proposed in the research can effectively optimize the seismic performance of multi ribbed composite walls.

State Crime

The International Criminal Tribunal for Rwanda’s historic judgment in the Akayesu Judgment established that rape and other forms of sexual violence can be an actus reus of genocide as defined by the United Nations Convention on Genocide Article II. The Akayesu Judgment therefore provides a logical framework to analyze a hidden episode of extreme post-colonial state violence in the newly independent Zimbabwe, namely a state policy of mass atrocities in Matabeleland and parts of the Midlands, targeting the minority Ndebele ethnic group during Operation Gukurahundi. The specific foci of this study are the patterns of mass rape and sexual violence in the military operation between 1983 and 1984 in Matabeleland. Drawing on 36 in-depth interviews with survivors from throughout Matabeleland, this study provides a critical new lens on Operation Gukurahundi through its identification of uniform systematic patterns of rape and other forms of sexual violence across Matabeleland. The article concludes that the patterns of rape and other forms of sexual violence identified in this study are indicative of a state policy of systematic genocidal rape between 1983 and 1984, deployed with the intent and effect to destroy, in part, a specific ethnic group, namely the minority Ndebele of Zimbabwe, thereby fulfilling every condition of the Genocide Convention principles of genocide.

Operation Gukurahundi: A Policy of Genocidal Rape and Sexual Violence in Zimbabwe, 1983–1984

The International Criminal Tribunal for Rwanda’s historic judgment in the Akayesu Judgment established that rape and other forms of sexual violence can be an actus reus of genocide as defined by the United Nations Convention on Genocide Article II. The Akayesu Judgment therefore provides a logical framework to analyze a hidden episode of extreme post-colonial state violence in the newly independent Zimbabwe, namely a state policy of mass atrocities in Matabeleland and parts of the Midlands, targeting the minority Ndebele ethnic group during Operation Gukurahundi. The specific foci of this study are the patterns of mass rape and sexual violence in the military operation between 1983 and 1984 in Matabeleland. Drawing on 36 in-depth interviews with survivors from throughout Matabeleland, this study provides a critical new lens on Operation Gukurahundi through its identification of uniform systematic patterns of rape and other forms of sexual violence across Matabeleland. The article concludes that the patterns of rape and other forms of sexual violence identified in this study are indicative of a state policy of systematic genocidal rape between 1983 and 1984, deployed with the intent and effect to destroy, in part, a specific ethnic group, namely the minority Ndebele of Zimbabwe, thereby fulfilling every condition of the Genocide Convention principles of genocide.

Mechanochemically Robust LiCoO2 with Ultrahigh Capacity and Prolonged Cyclability.

Pushing intercalation-type cathode materials to their theoretical capacity often suffers from fragile Li-deficient frameworks and severe lattice strain, leading to mechanical failure issues within the crystal structure and fast capacity fading. This is particularly pronounced in layered oxide cathodes because the intrinsic nature of their structures is susceptible to structural degradation with excessive Li extraction, which remains unsolved yet despite attempts involving elemental doping and surface coating strategies. Herein, a mechanochemical strengthening strategy is developed through a gradient disordering structure to address these challenges and push the LiCoO2 (LCO) layered cathode approaching the capacity limit (256mAhg-1, up to 93% of Li utilization). This innovative approach also demonstrates exceptional cyclability and rate capability, as validated in practical Ah-level pouch full cells, surpassing the current performance benchmarks. Comprehensive characterizations with multiscale X-ray, electron diffraction, and imaging techniques unveil that the gradient disordering structure notably diminishes the anisotropic lattice strain and exhibits high fatigue resistance, even under extreme delithiation states and harsh operating voltages. Consequently, this designed LCO cathode impedes the growth and propagation of particle cracks, and mitigates irreversible phase transitions. This work sheds light on promising directions toward next-generation high-energy-density battery materials through structural chemistry design.

The high power laser facility at beamline ID24-ED at the ESRF

ABSTRACT This paper describes technical details and new scientific opportunities offered by the new High Power Laser Facility at the ESRF, opened to users since 2022. This facility enables laser-induced dynamic compression experiments probed by ultra-fast X-ray Absorption Spectroscopy at beamline ID24-ED. This capability allows to reach and probe more extreme pressure and temperature states and higher strain rates with respect to static compression, addressing open questions in fundamental, planetary and material science.

Evolution of diapause in the African turquoise killifish by remodeling the ancient gene regulatory landscape

Suspended animation states allow organisms to survive extreme environments. The African turquoise killifish has evolved diapause as a form of suspended development to survive a complete drought. However, the mechanisms underlying the evolution of extreme survival states are unknown. To understand diapause evolution, we performed integrative multi-omics (gene expression, chromatin accessibility, and lipidomics) in the embryos of multiple killifish species. We find that diapause evolved by a recent remodeling of regulatory elements at very ancient gene duplicates (paralogs) present in all vertebrates. CRISPR-Cas9-based perturbations identify the transcription factors REST/NRSF and FOXOs as critical for the diapause gene expression program, including genes involved in lipid metabolism. Indeed, diapause shows a distinct lipid profile, with an increase in triglycerides with very-long-chain fatty acids. Our work suggests a mechanism for the evolution of complex adaptations and offers strategies to promote long-term survival by activating suspended animation programs in other species.