bluuebunny/crossref_metadata_2025 huggingface dataset:
Advanced Cardiovascular Magnetic Resonance Imaging in Takotsubo Syndrome: Update on Feature Tracking and Tissue Mapping
Authors: Sclafani Matteo , Tini Giacomo , Musumeci Beatrice , Cianca Alessandro , Maestrini Viviana , Cacciotti Luca , Arcari Luca
Published: May 2024

Backgrounds

Takotsubo syndrome (TTS) is an intriguing clinical entity characterized by transient myocardial dysfunction. The precise pathophysiological mechanism of TTS is still unknown, but recent evidence suggests a central role of systemic inflammation associated with adrenergic discharge. Although initially considered benign, TTS has shown several potential short-term and long-term complications and adverse outcomes. To improve understanding and management, advanced cardiovascular magnetic resonance (CMR) techniques, such as feature tracking (FT) and parametric mapping, have gained attention.

Purpose of Review

The purpose of this review is to summarize the current literature on the clinical applications of CMR-FT and mapping in TTS. Additionally, the most significant and recent findings will be discussed.

Recent Findings

FT-CMR enables the parametric quantification of myocardial deformation, allowing a comprehensive evaluation of left ventricular, right ventricular, and atrial function. It provides an accurate definition of areas of myocardial dysfunction and potentially serves as a superior prognostic tool compared to ejection fraction. Tissue mapping techniques enable precise and comprehensive tissue characterization by quantifying areas of oedema, and myocardial fibrosis.

FT-CMR and mapping techniques serve as valuable prognostic tools both in the acute and chronic phases of TTS. They can detect subtle alterations and pan-cardiac involvement, while also providing important insights into the complex underlying mechanisms of the syndrome.
Accurate Prediction of Lysine Methylation Sites Using Evolutionary and Structural-Based Information
Authors: Arafat Md. Easin , Ahmad Md. Wakil , Shovan S. M. , Haq Towhid Ul , Islam Nazrul , Mahmud Mufti , Kaiser M. Shamim
Published: May 2024

Methylation is considered one of the proteins’ most important post-translational modifications (PTM). Plasticity and cellular dynamics are among the many traits that are regulated by methylation. Currently, methylation sites are identified using experimental approaches. However, these methods are time-consuming and expensive. With the use of computer modelling, methylation sites can be identified quickly and accurately, providing valuable information for further trial and investigation. In this study, we propose a new machine-learning model called MeSEP to predict methylation sites that incorporates both evolutionary and structural-based information. To build this model, we first extract evolutionary and structural features from the PSSM and SPD2 profiles, respectively. We then employ Extreme Gradient Boosting (XGBoost) as the classification model to predict methylation sites. To address the issue of imbalanced data and bias towards negative samples, we use the SMOTETomek-based hybrid sampling method. The MeSEP was validated on an independent test set (ITS) and 10-fold cross-validation (TCV) using lysine methylation sites. The method achieved: an accuracy of 82.9% in ITS and 84.6% in TCV; precision of 0.92 in ITS and 0.94 in TCV; area under the curve values of 0.90 in ITS and 0.92 in TCV; F1 score of 0.81 in ITS and 0.83 in TCV; and MCC of 0.67 in ITS and 0.70 in TCV. MeSEP significantly outperformed previous studies found in the literature. MeSEP as a standalone toolkit and all its source codes are publicly available at https://github.com/arafatro/MeSEP.
Generation mechanism of overpressures caused by disequilibrium compaction in the northwestern Bozhong subbasin, China
Authors: Shi Liang , Jin Zhenkui , Zhu Xiao’er , Lin Mengli , Guan Baowen
Published: May 2024

In sedimentary basins, deep-seated overpressure conditions are frequently encountered. However, the precise origins of these overpressure conditions and the assessment of their formation times have long presented challenges. Previous studies have primarily relied on qualitative approaches to investigate overpressure origins, leading to substantial uncertainties in their findings. Based on theories such as the effective stress law, disequilibrium compaction, equilibrium depth, and nested fluid trapping containers in this paper, a new quantitative methodology is introduced for identifying the disequilibrium-compaction-induced origins of overpressure conditions. Additionally, the formation times of overpressure can be also estimated by nested fluid trapping container theory. This methodology is successfully applied to the northwestern Bozhong subbasin in the Bohai Bay Basin, China. The results indicate that the overpressure within the Dongying Formation of the northwestern Bozhong subbasin is primarily attributed to the disequilibrium compaction of mudstone, because the disequilibrium compaction of mudstone accounts for over 90% of the pressure in sandstone. Furthermore, the overpressure system in this area is not singular but comprises multiple nested relative fluid trapping containers. The application of nested fluid trapping container theory allows for an estimation of the overpressure’s formation time, although further validation of these estimates is required. It should be noted that the method proposed in this paper is particularly suited for sedimentary basins with relatively weak tectonic activity.
‘I do plan to do that in the future, just not the near future’: rural professional experience programs and pre-service teacher graduate destination preferences
Authors: Fish Tim , Bradbury Ondine , O’Donovan Richard , Larsen Ana , Komarzynski Lyn
Published: May 2024

This study examines pre-service teachers (PSTs) from two Australian universities regarding their involvement in rural professional experience (PE) placements and their potential impact on future career choices. The objective was to gain insight into the diverse teaching and learning experiences PSTs had during their rural PE, and what impact these had on their interest in working in country schools. This paper focuses on findings from urban and rural-based PSTs who undertook rural, regional and remote PE. PSTs reported that these experiences helped them develop rewarding pedagogical approaches and contributed to significant personal and professional growth. They reflected that their growth as a teacher arose from encountering diverse student cohorts, the school cultures they experienced, and the relationships they formed within the school community. However, despite these positive aspects, the PSTs’ intentions to pursue employment in rural areas remained diverse and personal. This suggests that while rural PE was highly valued, it was not sufficient to override individual circumstances and preferences when considering rural employment. It also seemed that the experiences may have inadvertently attracted PSTs open to change and adventure who utilised the support of rural mentors and communities, only to ultimately teach in metropolitan schools.
Khovanov homology, wedges of spheres and complexity
Authors: Przytycki Jozef H. , Silvero Marithania
Published: May 2024

Our main result has topological, combinatorial and computational flavor. It is motivated by a fundamental conjecture stating that computing Khovanov homology of a closed braid of fixed number of strands has polynomial time complexity. We show that the independence simplicial complex I(w) associated to the 4-braid diagram w (and therefore its Khovanov spectrum at extreme quantum degree) is contractible or homotopy equivalent to either a sphere, or a wedge of two spheres (possibly of different dimensions), or a wedge of three spheres (at least two of them of the same dimension), or a wedge of four spheres (at least three of them of the same dimension). On the algorithmic side we prove that finding the homotopy type of I(w) can be done in polynomial time with respect to the number of crossings in w. In particular, we prove the wedge of spheres conjecture for circle graphs obtained from 4-braid diagrams. We also introduce the concept of Khovanov adequate diagram and discuss criteria for a link to have a Khovanov adequate braid diagram with at most 4 strands.
Optimizing the drying conditions of date plum (Diospyros lotus L.) to conserve its phenolic content and antioxidants for preparing a highly bioaccessible polyphenol-rich tea
Authors: Pashazadeh Hojjat , Ali Redha Ali , Hassan Awadalgeed M. A. , Koca Ilkay
Published: May 2024

Date plum (Diospyros lotus L.) fruits are a good source of bioactive compounds and antioxidants. Drying can increase the shelf life of the fruit and its applications in the food development industry. Optimizing the drying conditions can help to produce prime-quality dried date plum fruits and conserve nutrients including phytochemicals. This study used a two-factor graphics-optimal design to optimize convective drying considering the air velocity and drying temperature of date plum fruits. The independent factors considered included drying temperature (43.78–86.21 °C) and air velocities (0.54–1.96 m/s), and the responses included total phenolic content (TPC), total flavonoid content (TFC), ferric reducing antioxidant power (FRAP), and 2,2-diphenyl-1-picrylhydrazy (DPPH) radical scavenging activity of date plum fruit. The optimized drying conditions (68 °C and 1.75 m/s) resulted in desirable TPC, TFC, FRAP, and DPPH values. The findings indicated that long drying time at low temperatures significantly decreased the phenolics and antioxidants. Date plum tea with different decoction times (5, 10, and 15 min) was prepared from fruits dried at optimum conditions. A decoction time of 5 min resulted in the highest catechin, vanillic, epicatechin, syringic acid, and quercetin-3-glucoside content, which were 2.45 ± 0.04, 11.06 ± 0.11, 22.03 ± 0.11, 12.95 ± 0.08, and 9.37 ± 0.10 mg/L; respectively. In vitro gastrointestinal digestion revealed that the tea product can be a source of highly bioaccessible (> 80%) gallic acid, catechin, vanillic acid, and quercetin-3-glucoside. Applying optimized drying conditions to dehydrate date plum fruit can be useful in preparing a highly bioaccessible polyphenol-rich tea.
Understanding the Novel Approach of Nanoferroptosis for Cancer Therapy
Authors: Sheikh Afsana , Kesharwani Prashant , Almalki Waleed H. , Almujri Salem Salman , Dai Linxin , Chen Zhe-Sheng , Sahebkar Amirhossein , Gao Fei
Published: May 2024

As a new form of regulated cell death, ferroptosis has unraveled the unsolicited theory of intrinsic apoptosis resistance by cancer cells. The molecular mechanism of ferroptosis depends on the induction of oxidative stress through excessive reactive oxygen species accumulation and glutathione depletion to damage the structural integrity of cells. Due to their high loading and structural tunability, nanocarriers can escort the delivery of ferro-therapeutics to the desired site through enhanced permeation or retention effect or by active targeting. This review shed light on the necessity of iron in cancer cell growth and the fascinating features of ferroptosis in regulating the cell cycle and metastasis. Additionally, we discussed the effect of ferroptosis-mediated therapy using nanoplatforms and their chemical basis in overcoming the barriers to cancer therapy.
Efficient and Stable Inverted Perovskite Solar Modules Enabled by Solid–Liquid Two-Step Film Formation
Authors: Zhang Juan , Ji Xiaofei , Wang Xiaoting , Zhang Liujiang , Bi Leyu , Su Zhenhuang , Gao Xingyu , Zhang Wenjun , Shi Lei , Guan Guoqing , Abudula Abuliti , Hao Xiaogang , Yang Liyou , Fu Qiang , Jen Alex K.-Y. , Lu Linfeng
Published: May 2024

A considerable efficiency gap exists between large-area perovskite solar modules and small-area perovskite solar cells. The control of forming uniform and large-area film and perovskite crystallization is still the main obstacle restricting the efficiency of PSMs. In this work, we adopted a solid–liquid two-step film formation technique, which involved the evaporation of a lead iodide film and blade coating of an organic ammonium halide solution to prepare perovskite films. This method possesses the advantages of integrating vapor deposition and solution methods, which could apply to substrates with different roughness and avoid using toxic solvents to achieve a more uniform, large-area perovskite film. Furthermore, modification of the NiOx/perovskite buried interface and introduction of Urea additives were utilized to reduce interface recombination and regulate perovskite crystallization. As a result, a large-area perovskite film possessing larger grains, fewer pinholes, and reduced defects could be achieved. The inverted PSM with an active area of 61.56 cm2 (10 × 10 cm2 substrate) achieved a champion power conversion efficiency of 20.56% and significantly improved stability. This method suggests an innovative approach to resolving the uniformity issue associated with large-area film fabrication.
Underlying catastrophes: umbilics and pattern formation
Authors: Jeffrey Mike R.
Published: May 2024

Bifurcation theory provides a very general means to classify the local changes in numbers of zeros of vector fields, but not a general means to find where a given bifurcation occurs, at least at higher codimensions. Instead, it turns out, these bifurcations can be found by looking for their underlying catastrophes. Here I show that the concept of underlying catastrophes can be extended to the umbilics. The umbilics are important in opening up qualitatively different forms of bifurcations beyond the ‘corank 1’ catastrophes of folds, cusps, swallowtails, etc. An example is given showing how four zeros of a vector field bifurcating from a single point, may do so either via a 3-parameter swallowtail catastrophe involving equilibria of similar stabilities, or via a 4-parameter umbilic catastrophe involving equilibria of opposing stabilities. This opens an avenue to studying spatiotemporal pattern formation around high codimension bifurcation points, and I conclude with some illustrative examples.
Praktiken des Zuweisens von (Il‑)Legitimität. Wie Grundschullehrer*innen im Anspruch der Inklusion pädagogische Tradierungen verhandeln
Authors: Olk Matthias
Published: May 2024

Im Anspruch der Inklusion sieht sich das Grundschullehrer*innenhandeln mit der Aufgabe konfrontiert, diesen Anspruch in die Alltagspraxis zu übersetzen. Dabei können die Eigenlogik der Praxis und die komplexen Erwartungen, die an die Grundschule im Anspruch der Inklusion gerichtet werden, nicht missachtet werden. An empirischen Beispielen wird in dem Beitrag der Frage nachgegangen, wie grundschulpädagogische Akteur*innen diese Übersetzungsleistung vollziehen. Dabei treten zwei unterschiedliche Modi der Zuweisung der (Il‑)Legitimität pädagogischer Tradierungen hervor. Sie werden kontrastierend dargestellt, um schließlich die Frage nach einer mehr oder weniger professionalisierten Bearbeitung der Aufgabe, die Gültigkeit pädagogischer Tradierungen im Anspruch der Inklusion zu verhandeln, zu diskutieren.
Decellularized porcine vena cava grafts are fully repopulated after orthotopic implantation
Authors: Palek Richard , Massaro Maria Stefania , Cervenkova Lenka , Moulisova Vladimira , Grajciarova Martina , Maleckova Anna , Hosek Petr , Rosendorf Jachym , Polak Robert , Sevcik Jan , Sarcevic Sima , Kepkova Lucie , Korcakova Eva , Mirka Hynek , Tonar Zbynek , Liska Vaclav
Published: May 2024

Tissue-engineered organs, based on native extracellular matrix (ECM) scaffolds, could be a game changer in regenerative medicine applications. Decellularization technology provides such scaffolds with organ-typic ECM composition and architecture. Despite limitations such as the requirement of huge cell numbers and finding the optimal route of entry, recellularized scaffolds provide alternative grafts for transplantation. In this study we assessed whether decellularized scaffolds, when implanted, are repopulated from the adjacent tissue. Since the vasculature plays an important role in tissue functionality, our main focus was to evaluate in situ repopulation of decellularized veins in a pig model. For this, porcine inferior vena cava grafts were decellularized and orthotopically implanted in recipient pigs (n = 12). To evaluate possible immune responses to the scaffolds and to assess potential thrombus formation, cellular allogeneic vena cava grafts were transplanted in control pigs (n = 8). Within 28 days after implantation, the decellularized veins were fully recellularized with endothelial cells and smooth muscle cells. Quantitative histological analysis showed a comparable amount of smooth muscle actin in the repopulated decellularized grafts similar to the native IVC. Lymphocyte infiltrates representing signs of graft rejection were not detected in the pigs, as opposed to the control group that received the allogeneic grafts. The decellularized grafts provoked a higher incidence of thrombosis in comparison with allogeneic grafts (33.3 vs. 12.5%). With this study, we show efficient in situ repopulation of decellularized vein grafts. These findings are insightful and promising to further explore the use of decellularized tissue without the need for full pre-transplant recellularization.

Graphical abstract
Conversion of iota carrageenan hydrocolloids to hydrophobic hydrocolloids, by the replacement of potassium to barium ion, for the entrapment of water insoluble drugs
Authors: Shukla Aman , Kumar Sachin , Bhatt Akanksha , Purohit Priyank
Published: May 2024

To entrap the water-insoluble medicine, the current innovation provides a cost-effective solution to the increasing need for hydrophobic gel. Improving the bioavailability of a medicine that is poorly soluble begins with entrapping the substance. By only switching out the monovalent ions for divalent ones, the researchers hope to increase the hydrophobicity of their material. In this experiment, barium ions were used instead of potassium ions in the iota carrageenan to make structural, chemical, and physicochemical changes easier during transformation. Hydrophobicity was determined qualitatively by observing the ability to trap small oil particles and repel water, moreover, the quantitative investigation was carried out using the weight loss method to determine the metal ion water isolation value and drug entrapment value within the core of barium linked carrageenan gel. The metal’s weight loss metal water affinity was determined to be 90% after 24 h, but it was only 67% with the synthesized gel coating the metal, this clearly shows that the barium gel had greater water protection activity. Furthermore, the barium-linked gel exhibited three times the entrapment capacity of the parent gel, and it successfully encased the water-insoluble medication with controlled release. The current study shows how the attached ion to the polymer changes its hydrophilic behavior into a hydrophobic one. This is a new and inexpensive way to do things. However, up until this point, the addition of the hydrophobic substrate and the functionalization of the polymer have been utilized. This leads to a plan that shows promise for improving the ability of hydrophobic hydrocolloid gels to hold drugs that do not dissolve in water.
Quantum deep learning-based anomaly detection for enhanced network security
Authors: Hdaib Moe , Rajasegarar Sutharshan , Pan Lei
Published: May 2024

Identifying and mitigating aberrant activities within the network traffic is important to prevent adverse consequences caused by cyber security incidents, which have been increasing significantly in recent times. Existing research mainly focuses on classical machine learning and deep learning-based approaches for detecting such attacks. However, exploiting the power of quantum deep learning to process complex correlation of features for anomaly detection is not well explored. Hence, in this paper, we investigate quantum machine learning and quantum deep learning-based anomaly detection methodologies to accurately detect network attacks. In particular, we propose three novel quantum auto-encoder-based anomaly detection frameworks. Our primary aim is to create hybrid models that leverage the strengths of both quantum and deep learning methodologies for efficient anomaly recognition. The three frameworks are formed by integrating the quantum autoencoder with a quantum one-class support vector machine, a quantum random forest, and a quantum k-nearest neighbor approach. The anomaly detection capability of the frameworks is evaluated using benchmark datasets comprising computer and Internet of Things network flows. Our evaluation demonstrates that all three frameworks have a high potential to detect the network traffic anomalies accurately, while the framework that integrates the quantum autoencoder with the quantum k-nearest neighbor yields the highest accuracy. This demonstrates the promising potential for the development of quantum frameworks for anomaly detection, underscoring their relevance for future advancements in network security.
Flexible Piezoelectric Sensor Based on Two-Dimensional Topological Network of PVDF/DA Composite Nanofiber Membrane
Authors: Xiong Junpeng , Wang Ling , Liang Fanghua , Li Mengying , Yabuta Yoshinori , Iqbal Muhammad Asim , Mayakrishnan Gopiraman , Shi Jian , Kim Ick Soo
Published: May 2024

Owing to the robust scalability, ease of control and substantial industrial applications, the utilization of electrospinning technology to produce piezoelectric nanofiber materials demonstrates a significant potential in the development of wearable products including flexible wearable sensors. However, it is unfortunate that the attainment of high-performance piezoelectric materials through this method remains a challenging task. Herein, a high-performance composite nanofiber membrane with a coherent and uniformly dispersed two-dimensional network topology composed of polyvinylidene fluoride (PVDF)/dopamine (DA) nanofiber membranes and ultrafine PVDF/DA nanofibers was successfully fabricated by the electrospinning technique. Based on the evidence obtained from simulations, experimental and theoretical results, it was confirmed that the unique structure of the nanofiber membrane significantly enhances the piezoelectric performance. The present PVDF/DA composite nanofibers demonstrated a remarkable piezoelectric performance such as a wide response range (1.5–40 N), high sensitivity to weak forces (0–4 N, 7.29 V N−1), and outstanding operational durability. Furthermore, the potential application of the present PVDF/DA membrane as a flexible wearable sensor for monitoring human motion and subtle physiological signals has also been validated. This work not only introduces a novel strategy for the application of electrospun nanofibers in sensors but also provides new insights into high-performance piezoelectric materials.

Graphical Abstract
Generalized Formal Model-Verifier: A Formal Approach for Verifying Static Models
Authors: Somogyi Norbert , Mezei Gergely
Published: May 2024

The field of software modeling has gained significant popularity in the last decades. By capturing the static aspects of the software requirements, model-driven engineering eases the development and maintenance of software. However, additional constraints, such as invariants on model elements, that the solution must conform to may be too complex to include in the structure of the model itself. External solutions are often used to describe static constraints on models, the most prevalent approach being the Object Constraint Language (OCL) and its formal variants. This paper proposes the Generalized Formal Model-Verifier (GFMV), which is a general approach for verifying static constraints on software models. GFMV employs different formal verification methods based on Kripke Structures. Kripke Structures are used to capture the static structure of the model, then the constraints are formalized using a first-order branching-time logic, the Computational Tree Logic (CTL). Finally, the NuSMV model checker is reused to verify whether the constraints formalized in CTL hold on the formal Kripke Structure. When compared to existing solutions, GFMV offers increased generality and formal proof that the constraints hold on the model. The expressive power and runtime-scalability of the approach are evaluated on a real-world example model and OCL invariants cited from literature.
Snap-induced flow in a closed channel
Authors: Oshri Oz , Goncharuk Kirill , Feldman Yuri
Published: May 2024

Snap-through is a buckling instability that allows slender objects, including those in plant and biological systems, to generate rapid motion that would be impossible if they were to use their internal forces exclusively. In microfluidic devices, such as micromechanical switches and pumps, this phenomenon has practical applications for manipulating fluids at small scales. The onset of this elastic instability often drives the surrounding fluid into motion – a process known as snap-induced flow. To analyse the complex dynamics resulting from the interaction between a sheet and a fluid, we develop a prototypical model of a thin sheet that is compressed between the two sides of a closed channel filled with an inviscid fluid. At first, the sheet bends towards the upstream direction and the system is at rest. However, once the pressure difference in the channel exceeds a critical value, the sheet snaps to the opposite side and drives the fluid dynamics. We formulate an analytical model that combines the elasticity of thin sheets with the hydrodynamics of inviscid fluids to explore how external pressure differences, material properties and geometric factors influence the system's behaviour. To analyse the early stages of the evolution, we perform a linear stability analysis and obtain the growth rate and the critical pressure difference for the onset of the instability. A weakly nonlinear analysis suggests that the system can exhibit a pressure spike in the vicinity of the inverted configuration.
Revisiting the evidence on thermostatic response to democratic change: degrees of democratic support or researcher degrees of freedom?
Authors: Hu Yue , Tai Yuehong Cassandra , Solt Frederick
Published: May 2024

Prominent recent work argues that support for democracy behaves thermostatically—that democratic erosion boosts democratic support while deepening democracy yields public backlash—and further contends that there is no evidence for the classic argument that democracy itself increases democratic support over time. Here, we document how these conclusions depend on subtle choices in measurement coding that constitute “researcher degrees of freedom”: analyses employing alternative reasonable choices provide little or no support for the original conclusions. The fragility of the statistical results demonstrates that researcher degrees of freedom in measurement must be taken seriously and that the question of the relationship between democratic institutions and democratic support remains unsettled.
Thinness of some hypergeometric groups in
$\mathrm{Sp}(6)$
Authors: Singh Sandip , Singh Shashank Vikram
Published: May 2024

We show the thinness of
$7$
of the
$40$
hypergeometric groups having a maximally unipotent monodromy in
$\mathrm{Sp}(6)$
.
What are the limits of political violence? Ebihara Toshio’s murder and the Umemoto-Kuroda controversy in 1970s Japan
Authors: de Vargas Ferran
Published: May 2024

On 3 August 1970, a student activist belonging to the Kakumaru-ha (Revolutionary Marxist Faction) was beaten to death by members of the rival Chūkaku-ha (Central Core Faction) at Hosei University, Tokyo. This incident sparked an intense war between Japanese New Left factions that stretched into the 1980s and resulted in dozens of deaths, making Japan a unique case among industrialized nations for its extremely high level of left-wing interfactional violence. Of particular importance in understanding the ideological factors surrounding such an escalation of violence was the debate triggered between Umemoto Katsumi, one of the intellectual founders of the Japanese New Left, and members of the Kakumaru-ha led by Kuroda Kan’ichi around the limits of political violence. This article explores the theoretical confrontation between these two opposing sides that was of such critical importance to the logic of war between Japanese New Left factions in the 1970s and 1980s.
Learning vision-based robotic manipulation tasks sequentially in offline reinforcement learning settings
Authors: Yadav Sudhir Pratap , Nagar Rajendra , Shah Suril V.
Published: May 2024

With the rise of deep reinforcement learning (RL) methods, many complex robotic manipulation tasks are being solved. However, harnessing the full power of deep learning requires large datasets. Online RL does not suit itself readily into this paradigm due to costly and time-consuming agent-environment interaction. Therefore, many offline RL algorithms have recently been proposed to learn robotic tasks. But mainly, all such methods focus on a single-task or multitask learning, which requires retraining whenever we need to learn a new task. Continuously learning tasks without forgetting previous knowledge combined with the power of offline deep RL would allow us to scale the number of tasks by adding them one after another. This paper investigates the effectiveness of regularisation-based methods like synaptic intelligence for sequentially learning image-based robotic manipulation tasks in an offline-RL setup. We evaluate the performance of this combined framework against common challenges of sequential learning: catastrophic forgetting and forward knowledge transfer. We performed experiments with different task combinations to analyse the effect of task ordering. We also investigated the effect of the number of object configurations and the density of robot trajectories. We found that learning tasks sequentially helps in the retention of knowledge from previous tasks, thereby reducing the time required to learn a new task. Regularisation-based approaches for continuous learning, like the synaptic intelligence method, help mitigate catastrophic forgetting but have shown only limited transfer of knowledge from previous tasks.
Compliant variable admittance adaptive fixed-time sliding mode control for trajectory tracking of robotic manipulators
Authors: Gao Hang , Ma Chao , Zhang Xiaodong , Zhou Cheng
Published: May 2024

This paper presents a compliant variable admittance adaptive fixed-time sliding mode control (SMC) algorithm for trajectory tracking of robotic manipulators. Specifically, a compliant variable admittance algorithm and an adaptive fixed-time SMC algorithm are combined to construct a double-loop control structure. In the outer loop, the variable admittance algorithm is developed to adjust admittance parameters during a collision to minimize the collision time, which gives the robot compliance property and reduce the rigid collision influence. Then, by employing the Lyapunov theory and the fixed-time stability theory, a new nonsingular sliding mode manifold is proposed and an adaptive fixed-time SMC algorithm is presented in the inner loop. More precisely, this approach enables rapid convergence, enhanced steady-state tracking precision, and a settling time that is independent of system initial states. As a result, the effectiveness and improved performance of the proposed algorithm are demonstrated through extensive simulations and experimental results.
Threshold dynamics scenario of a plants-pollinators cooperative system with impulsive effect on a periodically evolving domain
Authors: Wang Jie , Yang Ruirui , Wang Jian , Cao Jianxiong
Published: May 2024

Flowering plants depend on some animals for pollination and contribute to nourish the animals in natural environments. We call these animals pollinators and build a plants-pollinators cooperative model with impulsive effect on a periodically evolving domain. Next, we define the ecological reproduction index for single plant model and plants-pollinators system, respectively, whose threshold dynamics, including the extinction, persistence and coexistence, is established by the method of upper and lower solutions. Theoretical analysis shows that a large domain evolution rate has a positive influence on the survival of pollinators whether or not the impulsive effect occurs, and the pulse eliminates the pollinators even when the evolution rate is high. Moreover, some selective numerical simulations are still performed to explain our theoretical results.
Demographics and FDI: lessons from China’s one-child policy
Authors: Donaldson John B. , Koulovatianos Christos , Li Jian , Mehra Rajnish
Published: May 2024

Following the introduction of the one-child policy in China, the capital-labor ratio of China increased relative to that of India, while FDI/GDP inflows to China versus India simultaneously declined. These observations are explained in the context of a simple neoclassical overlapping generations paradigm. The adjustment mechanism works as follows: the reduction in the growth rate of the (urban) labor force due to the one-child policy increases the capital per worker inherited from the previous generation. The resulting increase in China’s domestic capital-labor ratio thus "crowds out" the need for foreign direct investment (FDI) in China relative to India. Our paper is a contribution to the nascent literature exploring demographic transitions and their effects on FDI flows.
Challenges in Evaluating Climate Sensitivity from Climate Models
Authors: Rajaram Harihar , Camargo Suzana , Giannini Alessandra , Su Hui
Published: May 2024

In recognition of the 50th anniversary of Geophysical Research Letters, the editors showcase an exceptional study published in the journal that investigates the climate sensitivity in CMIP6 models.
Raindrop Deformation in Turbulence
Authors: Zheng Hepeng , Zhang Yun , Li Haoran , Wu Zuhang , Xie Yanqiong , Zhang Lifeng
Published: May 2024

The physical behavior of a falling raindrop is governed by delicate fluid dynamics and thermodynamics, and oscillates with time. Despite this time‐variant nature, past observational and simulation studies have aimed to generalize parameterizations for describing rain microphysics bearing the assumption that raindrops fall at terminal speeds with an equilibrium shape. However, the applicability of this hypothesis in a realistic atmosphere that is inherently turbulent remains an open question. Here, we employ novel retrieval techniques to quantify the impact of turbulence on raindrop microphysics using long‐term in situ observations with careful assessment of the wind effect. We find that raindrop microphysics increasingly deviate from the equilibrium state as the turbulence dissipation rate increases, and this effect is more pronounced for large raindrops. We present turbulence‐invoked rain microphysical parameterizations which shed light on the complex interactions between turbulence dynamics and raindrop microphysics.
Atlantic Meridional Overturning Circulation Influence on the Annual Mean Intertropical Convergence Zone Location in the Miocene
Authors: Liu Xiaoqing , Herold Nicholas , Huber Matthew
Published: May 2024

The Intertropical Convergence Zone (ITCZ) has an annual mean location north of the equator today. The factors determining this location and the evolution to its modern state are actively debated. Here we investigate how the Atlantic Meridional Overturning Circulation (AMOC) influences the ITCZ during the early‐to‐middle Miocene. By conducting a sensitivity study with an open Canadian Arctic Archipelago gateway, we show that North Atlantic Deep‐Water formation strengthens the AMOC, in alignment with Miocene North Atlantic ventilation proxies. A vigorous AMOC increases northward Atlantic Ocean heat transport and cross‐equatorial atmospheric energy transport shifts southwards to compensate, pushing the ITCZ northwards. Our study supports AMOC development as a strong contributor to the ITCZ's northern location today. Existing proxy‐based interpretations of ITCZ history are too sparse to strongly confirm these results. We predict a strong in‐phase relationship between AMOC strength and ITCZ's northward location, which should be testable in high resolution paleoclimate records.
Velocity Measurements of Powdered Rock at Low Confining Pressures and Comparison to Lunar Shallow Seismic Velocity
Authors: Amos C. C. , Prasad M. , Cannon K. M. , Dreyer C. B.
Published: May 2024

Seismic methods will be useful for future lunar near‐surface characterization, and high‐fidelity elastic models will be required to aid interpretation of seismic observations. To develop an elastic lunar near‐surface model, we performed ultrasonic velocity measurements of lunar regolith simulant at low confining pressure and developed a rock physics model calibrated to these measurements. Grain contact models based on Hertz‐Mindlin theory produce accurate results at high confining pressure (i.e., several hundred meters or more burial depth) but historically fail to predict observed velocities in unconsolidated media at low pressure. Therefore, we heuristically modified existing models to fit our measured data over a range of porosities and confining pressures. To compare with Apollo 14 and 16 active seismic experiments, we used our new heuristic rock physics model to produce lunar subsurface velocity profiles. We performed ray tracing through our velocity profiles to calculate seismic traveltime, which results in good agreement with first arrivals interpreted from the Apollo experiments. Our model suggests a slightly higher velocity‐pressure dependence than inferred from in situ measurements, which may be due to porosity reduction in the lunar regolith from impact‐induced and natural vibrations.
Patient-derived follicular lymphoma spheroids recapitulate lymph node signaling and immune profile uncovering galectin-9 as a novel immunotherapeutic target
Authors: Dobaño-López Cèlia , Valero Juan García , Araujo-Ayala Ferran , Nadeu Ferran , Gava Fabien , Faria Carla , Norlund Marine , Morin Renaud , Bernes-Lasserre Pascale , Arenas Fabian , Grau Marta , López Cristina , López-Oreja Irene , Serrat Neus , Martínez-Farran Ares , Hernández Lluís , Playa-Albinyana Heribert , Giménez Rubén , Beà Silvia , Campo Elías , Lagarde Jean-Michel , López-Guillermo Armando , Magnano Laura , Colomer Dolors , Bezombes Christine , Pérez-Galán Patricia
Published: May 2024

Follicular lymphoma (FL), the most common indolent non-Hodgkin lymphoma, constitutes a paradigm of immune tumor microenvironment (TME) contribution to disease onset, progression, and heterogenous clinical outcome. Here we present the first FL-Patient Derived Lymphoma Spheroid (FL-PDLS), including fundamental immune actors and features of TME in FL lymph nodes (LNs). FL-PDLS is organized in disc-shaped 3D structures composed of proliferating B and T cells, together with macrophages with an intermediate M1/M2 phenotype. FL-PDLS recapitulates the most relevant B-cell transcriptional pathways present in FL-LN (proliferation, epigenetic regulation, mTOR, adaptive immune system, among others). The T cell compartment in the FL-PDLS preserves CD4 subsets (follicular helper, regulatory, and follicular regulatory), also encompassing the spectrum of activation/exhaustion phenotypes in CD4 and CD8 populations. Moreover, this system is suitable for chemo and immunotherapy testing, recapitulating results obtained in the clinic. FL-PDLS allowed uncovering that soluble galectin-9 limits rituximab, rituximab, plus nivolumab/TIM-3 antitumoral activities. Blocking galectin-9 improves rituximab efficacy, highlighting galectin-9 as a novel immunotherapeutic target in FL. In conclusion, FL-PDLS maintains the crosstalk between malignant B cells and the immune LN-TME and constitutes a robust and multiplexed pre-clinical tool to perform drug screening in a patient-derived system, advancing toward personalized therapeutic approaches.
A novel inhibitor of the mitochondrial respiratory complex I with uncoupling properties exerts potent antitumor activity
Authors: Al Assi Alaa , Posty Solène , Lamarche Frédéric , Chebel Amel , Guitton Jérôme , Cottet-Rousselle Cécile , Prudent Renaud , Lafanechère Laurence , Giraud Stéphane , Dallemagne Patrick , Suzanne Peggy , Verney Aurélie , Genestier Laurent , Castets Marie , Fontaine Eric , Billaud Marc , Cordier-Bussat Martine
Published: May 2024

Cancer cells are highly dependent on bioenergetic processes to support their growth and survival. Disruption of metabolic pathways, particularly by targeting the mitochondrial electron transport chain complexes (ETC-I to V) has become an attractive therapeutic strategy. As a result, the search for clinically effective new respiratory chain inhibitors with minimized adverse effects is a major goal. Here, we characterize a new OXPHOS inhibitor compound called MS-L6, which behaves as an inhibitor of ETC-I, combining inhibition of NADH oxidation and uncoupling effect. MS-L6 is effective on both intact and sub-mitochondrial particles, indicating that its efficacy does not depend on its accumulation within the mitochondria. MS-L6 reduces ATP synthesis and induces a metabolic shift with increased glucose consumption and lactate production in cancer cell lines. MS-L6 either dose-dependently inhibits cell proliferation or induces cell death in a variety of cancer cell lines, including B-cell and T-cell lymphomas as well as pediatric sarcoma. Ectopic expression of Saccharomyces cerevisiae NADH dehydrogenase (NDI-1) partially restores the viability of B-lymphoma cells treated with MS-L6, demonstrating that the inhibition of NADH oxidation is functionally linked to its cytotoxic effect. Furthermore, MS-L6 administration induces robust inhibition of lymphoma tumor growth in two murine xenograft models without toxicity. Thus, our data present MS-L6 as an inhibitor of OXPHOS, with a dual mechanism of action on the respiratory chain and with potent antitumor properties in preclinical models, positioning it as the pioneering member of a promising drug class to be evaluated for cancer therapy.
Anomalous dynamics of a passive droplet in active turbulence
Authors: Singh Chamkor , Chaudhuri Abhishek
Published: May 2024

Motion of a passive deformable object in an active environment serves as a representative of both in-vivo systems such as intracellular particle motion in Acanthamoeba castellanii, or in-vitro systems such as suspension of beads inside dense swarms of Escherichia coli. Theoretical modeling of such systems is challenging due to the requirement of well resolved hydrodynamics which can explore the spatiotemporal correlations around the suspended passive object in the active fluid. We address this critical lack of understanding using coupled hydrodynamic equations for nematic liquid crystals with finite active stress to model the active bath, and a suspended nematic droplet with zero activity. The droplet undergoes deformation fluctuations and its movement shows periods of “runs” and “stays”. At relatively low interfacial tension, the droplet begins to break and mix with the outer active bath. We establish that the motion of the droplet is influenced by the interplay of spatial correlations of the flow and the size of the droplet. The mean square displacement shows a transition from ballistic to normal diffusion which depends on the droplet size. We discuss this transition in relation to spatiotemporal scales associated with velocity correlations of the active bath and the droplet.
Multi-site integrated optical addressing of trapped ions
Authors: Kwon Joonhyuk , Setzer William J. , Gehl Michael , Karl Nicholas , Van Der Wall Jay , Law Ryan , Blain Matthew G. , Stick Daniel , McGuinness Hayden J.
Published: May 2024

One of the most effective ways to advance the performance of quantum computers and quantum sensors is to increase the number of qubits or quantum resources in the system. A major technical challenge that must be solved to realize this goal for trapped-ion systems is scaling the delivery of optical signals to many individual ions. In this paper we demonstrate an approach employing waveguides and multi-mode interferometer splitters to optically address multiple 171Yb+ ions in a surface trap by delivering all wavelengths required for full qubit control. Measurements of hyperfine spectra and Rabi flopping were performed on the E2 clock transition, using integrated waveguides for delivering the light needed for Doppler cooling, state preparation, coherent operations, and detection. We describe the use of splitters to address multiple ions using a single optical input per wavelength and use them to demonstrate simultaneous Rabi flopping on two different transitions occurring at distinct trap sites. This work represents an important step towards the realization of scalable integrated photonics for atomic clocks and trapped-ion quantum information systems.
Delayed room temperature phosphorescence enabled by phosphines
Authors: Lu Guang , Tan Jing , Wang Hongxiang , Man Yi , Chen Shuo , Zhang Jing , Duan Chunbo , Han Chunmiao , Xu Hui
Published: May 2024

Organic ultralong room-temperature phosphorescence (RTP) usually emerges instantly and immediately decays after excitation removal. Here we report a new delayed RTP that is postponed by dozens of milliseconds after excitation removal and decays in two steps including an initial increase in intensity followed by subsequent decrease in intensity. The delayed RTP is achieved through introduction of phosphines into carbazole emitters. In contrast to the rapid energy transfer from single-molecular triplet states (T1) to stabilized triplet states (Tn*) of instant RTP systems, phosphine groups insert their intermediate states (TM) between carbazole-originated T1 and Tn* of carbazole-phosphine hybrids. In addition to markedly increasing emission lifetimes by ten folds, since TM → Tn* transition require >30 milliseconds, RTP is thereby postponed by dozens of milliseconds. The emission character of carbazole-phosphine hybrids can be used to reveal information through combining instant and delayed RTP, realizing multi-level time resolution for advanced information, biological and optoelectronic applications.
Timing the evolution of phosphorus-cycling enzymes through geological time using phylogenomics
Authors: Boden Joanne S. , Zhong Juntao , Anderson Rika E. , Stüeken Eva E.
Published: May 2024

Phosphorus plays a crucial role in controlling biological productivity, but geological estimates of phosphate concentrations in the Precambrian ocean, during life’s origin and early evolution, vary over several orders of magnitude. While reduced phosphorus species may have served as alternative substrates to phosphate, their bioavailability on the early Earth remains unknown. Here, we reconstruct the phylogenomic record of life on Earth and find that phosphate transporting genes (pnas) evolved in the Paleoarchean (ca. 3.6-3.2 Ga) and are consistent with phosphate concentrations above modern levels ( > 3 µM). The first gene optimized for low phosphate levels (pstS; <1 µM) appeared around the same time or in the Mesoarchean depending on the reconstruction method. Most enzymatic pathways for metabolising reduced phosphorus emerged and expanded across the tree of life later. This includes phosphonate-catabolising CP-lyases, phosphite-oxidising pathways and hypophosphite-oxidising pathways. CP-lyases are particularly abundant in dissolved phosphate concentrations below 0.1 µM. Our results thus indicate at least local regions of declining phosphate levels through the Archean, possibly linked to phosphate-scavenging Fe(III), which may have limited productivity. However, reduced phosphorus species did not become widely used until after the Paleoproterozoic Great Oxidation Event (2.3 Ga), possibly linked to expansion of the biosphere at that time.