Closure Process Research Articles

Cooling down AI regulation controversies: Three closure processes in the Chilean legislative arena

According to social studies of artificial intelligence (AI), public AI controversies tend to dissipate relatively quickly despite well-documented risks and harms. The reasons for this lack of controversiality are beginning to be studied. Drawing on the framework of sociotechnical controversies, we analyze the de-escalation of contentious discussions observed in the AI legislative process by Chile's National Congress. Utilizing a qualitative approach, we tracked the deliberations hosted by the Chamber of Deputies and the Senate of Chile across 51 sessions between 2023 and 2024. We describe three processes of cooling down in the AI debates: (1) deflection of technology liability, (2) instrumentalization of technology policy, and (3) moralization of technology use. However, constructive exchanges appear in some circumstances, which allow us to foresee some favorable conditions for participation in the debates on AI regulation. This paper contributes to AI controversy studies by outlining cooling-down processes and conditions that foster dialogue and providing a critical perspective on the formation of AI regulation.

Papillary Muscles of the Left Ventricle: Integrating Electrical and Mechanical Dynamics.

Papillary muscles are structures integrated into the mitral valve apparatus, having both electrical and mechanical roles. The importance of the papillary muscles (PM) is mainly related to cardiac arrhythmias and mitral regurgitation. The aim of this review is to offer an overview of the anatomy and physiology of the papillary muscles, along with their involvement in cardiovascular pathologies, including arrhythmia development in various conditions and their contribution to secondary mitral regurgitation. A literature search was performed on PubMed using the following relevant keywords: papillary muscles, mitral valve, arrhythmia, anatomy, and physiology. During the cardiac cycle, papillary muscles have continuous dimensional and pressure changes. On one hand, their synchrony or dyssynchrony impacts the process of mitral valve opening and closure, and on the other hand, the pressure changes can trigger electrical instability. There is increased awareness of papillary muscles as an arrhythmic source. Arrhythmias arising from PM were found in patients with or without structural heart disease, via Purkinje fibres, due to increased automaticity or triggered activity. Despite the interest in mitral valve physiology, there are still many unknowns in relation to the papillary muscles, especially with regard to their role in arrhythmogenesis and the pathogenesis of mitral regurgitation.

Excluded voices in inclusive child and youth welfare services

ABSTRACT The voices of social work service users in Germany are getting increasingly prominent. The recent developments in the Child and Youth Welfare Act (SGB VIII) illustrate that participation, self-organisation, and self-representation rights are receiving heightened attention. Simultaneously, questions regarding the requirements, conditions, and possibilities of self-organisation have received relatively minuscule attention so far. Who has the means and opportunities for self-organisation under which conditions? How are social closure processes of significance? What consequences does it have for service users? What insights can we gain at the intersection of social work and special education? In this article, we seek to explore these questions. Initially, we take a journey through history, shedding light on the question of the virulence of social closure and usurpation processes within user movements. Based on this historical recapitulatory overview and repositories of paradigms and theories on social inequality, we take a look at current transformations in the voices of service users within the social services system. Through interviews with self-advocates in child and youth welfare and disability assistance services, and the analysis of official documents from self-advocacy organisations, we illustrate the capacity for a redirection of attention on the voices of service users guided by closure theory.

Initiation of epithelial wound closure by an active instability at the purse string

The ability of biological systems to withstand and recover from various disruptions, such as spontaneous genetic mutations and environmental damage, largely relies on intricate feedback mechanisms. We theoretically study the mechanical response of an epithelial tissue facing damage in the form of a circular wound. Our model describes a feedback loop between the generation of active forces in the actomyosin and tissue mechanics, described by the vertex model. While the exact dynamics of wound closure may be influenced by several biophysical mechanisms that interplay in a nontrivial way, our findings suggest that the closure may initiate as an active instability, triggered by a reduced myosin turnover rate at the wound’s perimeter. We explore the interplay between myosin dynamics and the elastic properties of the tissue, elucidating their collective role in determining a wound’s loss of stability, leading to the initiation of the closure process.

Accomplishing lesson ending: bringing lesson to an end

ABSTRACT This ethnomethodological study examines the dynamics of lesson closure in diverse classroom settings, drawing on the sequential analysis of five video-recorded lessons in history, literature, chemistry, and geography classes. The detailed analysis of teacher-student interactions during the lesson endings in a tenth-grade high school classroom in Ankara sheds light on the temporal, social, and interactional processes involved in concluding lessons. The ringing of the bell emerges as a key temporal marker signalling the end of the lesson, while teachers play a central role in orchestrating closure through verbal and non-verbal cues. The interactional dynamics between teachers and students also reveal the negotiation of roles and responsibilities, with students demonstrating orientation to the lesson closure through preparatory actions. Furthermore, the structured nature of lesson closure is evident in sequential patterns and the deployment of terminal components. The study highlights the dynamic nature of classroom interactions during lesson endings, underscoring the formal interactional dynamics at play. Overall, the findings contribute to the understanding of lesson closure processes and offer insights for educators, researchers, and policymakers aiming to enhance teaching and learning experiences in diverse educational contexts.

Notch signaling regulates limb regeneration through Hes1 and HeyL in the Chinese mitten crab

Tissue regeneration is an efficient strategy developed by animals to compensate for damaged tissues, involving various types of progenitor cells. Deciphering the signal network that modulates the activity of these progenitors during regeneration is crucial for understanding the differences in regenerative capacities across species. In this study, we evaluated the expression profile and phenotypic function of Notch signaling during limb regeneration in arthropod Chinese mitten crabs. The expression of key components of the Notch signaling pathway was upregulated at 7-day post-autotomy (7 DPA), and declined later at 18-day post-autotomy (18 DPA). To assess the role of Notch, we injected dsRNA targeting the Notch gene into the automized area and evaluated the regeneration efficiency. Our results indicated that blocking Notch signaling led to regenerative defects, manifested by delays in the wound closure and blastema emergence processes. Furthermore, the expression of Notch target genes, Hes1 and HeyL, was significantly reduced following Notch knockdown by dsRNA. Knockdown of Hes1 specifically impaired the proliferation and expression of neural progenitor cell markers, without affecting myogenic cells. In contrast, blockage of HeyL inhibited the proliferation and expression of markers in both activated neurogenic and myogenic progenitor cells, while up-regulating markers of quiescent neural progenitor cells. These findings suggest that Notch signaling plays an important role in limb regeneration of E. sinensis by activating downstream effectors Hes1 and HeyL, regulating neurogenesis and myogenesis through distinct mechanisms.

Boron in wound healing: a comprehensive investigation of its diverse mechanisms.

Chronic wounds present a significant clinical challenge due to their prolonged healing time and susceptibility to infection. Boron, a trace element with diverse biological functions, has emerged as a promising therapeutic agent in wound healing. This review article comprehensively investigates the mechanisms underlying the beneficial effects of boron compounds in wound healing. Boron exerts its healing properties through multiple pathways, including anti-inflammatory, antimicrobial, antioxidant, and pro-proliferative effects. Inflammation is a crucial component of the wound-healing process, and boron has been shown to modulate inflammatory responses by inhibiting pro-inflammatory cytokines and promoting the resolution of inflammation. Furthermore, boron exhibits antimicrobial activity against a wide range of pathogens commonly associated with chronic wounds, thereby reducing the risk of infection and promoting wound closure. The antioxidant properties of boron help protect cells from oxidative stress, a common feature of chronic wounds that can impair healing. Additionally, boron stimulates cell proliferation and migration, as well as essential tissue regeneration and wound closure processes. Overall, this review highlights the potential of boron as a novel therapeutic approach for treating chronic wounds, offering insights into its diverse mechanisms of action and clinical implications.

Social terminology in “Traité de la Noblesse” by Gilles-André La Roque de La Lontière (1678)

The “Traité de la noblesse” by Gilles-André de La Rocque de La Lontière is an example of the treatises on nobility that were prevalent in early modern Europe. The author, a renowned French genealogist, heraldist, and royal historiographer, presented his work as a comprehensive summary and conclusion on the issues surrounding nobility in French society. Although Larocque’s voluminous treatise has been referenced by researchers of the French nobility, it has not been the subject of in-depth investigation by Russian historians. This paper aims to address this gap in the historical literature by analysing the major problems outlined in the treatise and the social terminology used by Larocque as a reflection of the process of defining the boundaries of the noble estate in early modern France. The close subject and epistemic connection between the nobiliary discourse and the French erudite intellectual current is demonstrated. The process of closure of the nobility that took place at that time required the delineation of the boundary between the nobility and the roturiers. In this regard, the internal structure of the French nobility was of little interest to La Rocque, who focused on clarifying its lower border. He provides a detailed account of the terms used to define the borderline between the lower levels of nobility. Larocque addresses the controversial question of the dignity of the old and new nobility, concluding that they are equivalent.

Above-threshold ionization with X-ray free-electron lasers

This study delves into the relatively uncharted territory of Above Threshold Ionization in atoms, triggered by intense X-ray radiation fields. At these frequencies, the energy of a single photon far exceeds the ionization potential of valence electrons in atoms and molecules. The conditions we examine are similar to those achievable with current or future free-electron laser facilities. Under such high-energy scenarios, the onset of strong field ionization requires a shift away from the traditional quasi-classical approach. Here, we present an analytical model to characterize how the field-free ionization potential, ponderomotive energy, and photon energy govern the transition to this regime, all accounted for by means of the Keldysh and Reiss parameters. We show that both of these parameters are needed to capture the onset of strong-field behavior due to both bound state and continuum state properties. At higher X-ray intensities, we find that ionization rates deviate from the linear intensity scaling expected from lowest order perturbative processes, corresponding to channel closure and higher-order photon absorption processes.

T2-weighted spoiled gradient echo MRI for forensic age estimation: a study on knee growth plates

The timing of growth plate fusion is a key indicator for age estimation and is primarily used in forensic investigations. On the other hand, non-ionizing techniques such as MRI are being developed to provide safer and more ethical evaluations in forensic casework. This study aims to evaluate the closure process of growth plates in the distal femoral and proximal tibial epiphyses using Multiple Echo Recombined Gradient Echo (MERGE) MRI sequences and provide age estimation data based on staging methods for forensic purposes. We retrospectively analyzed 559 patients (294 males, 265 females, aged 8–25 years) diagnosed with trauma and knee pain at Tepecik Training and Research Hospital from 2016 to 2019. MRI scans were performed using a 1.5-T system with MERGE sequences and evaluated by two observers using a new staging system. Observer agreement was assessed using Cohen’s κ test, yielding high agreement values (κ > 0.8). Positive correlations were found between age and ossification stages (p < 0.001). Minimum age thresholds for stages 5a and 5b of the distal femoral epiphysis were 16 and 18 years for females and 17 and 19 years for males, respectively. For the proximal tibial epiphysis, the minimum ages for stages 5a and 5b were 15 years for females and 17 years for males. The MERGE sequence provides a viable method for assessing skeletal maturity in living individuals with significant ethical advantages due to non-ionizing radiation. This study supports the potential application of the MERGE sequence in forensic age estimation, demonstrating high observer agreement and consistency. Future research should focus on comparing different sequences and populations to enhance the methodology’s applicability.

Engagement strategies in the context of the Itabira mine closure: impacts and stakeholder participation

Purpose: This article aims to propose and apply a set of analytical categories for evaluating engagement in mine closure processes. Design/methodology/approach: The qualitative research adopts a case study strategy considering the singularity of the phenomenon studied. The mine project analyzed is the country's first large-scale closure, scheduled for 2041, with the potential to influence future processes. Data collection involved observation, documentary analysis, and interviews. Sixteen interviews were conducted with representatives from the public power, community, organizations, and the company. The research strategy chosen was content analysis using the analytical categories raised in the literature review and triangulation of data collection sources. Findings: The results highlight the importance of the mining company's active role in constructing the city's post-mining future, collaborating to reconvert socio-economic dynamics, and fostering a trusting relationship with the community. However, the company remains distant from the debate. Interviews revealed a paternalistic relationship between the mining company that guides engagement in a predominantly unilateral flow, with communication directed to meet its interests. Originality/value: This research fills a gap in the existing literature by focusing on engagement in a vulnerable context. It contributes to the theoretical advancement of the main characteristics of engagement in mine closure processes and for dialogue practices with communities to favor sustainable territory development in the post-mining period.

Drawing of fibres composed of shear-thinning or shear-thickening fluid with internal holes

We explore the drawing of a shear-thinning or shear-thickening thread with an axisymmetric hole that evolves due to axial drawing, inertia and surface tension effects. The stress is assumed to be proportional to the shear rate raised to the $n$ th power. The presence of non-Newtonian rheology and surface tension forces acting on the hole introduces radial pressure gradients that make the derivation of long-wavelength equations significantly more challenging than either a Newtonian thread with a hole or shear-thinning and shear-thickening threads without a hole. In the case of weak surface tension, we determine the steady-state profiles. Our results show that for negligible inertia the hole size at the exit becomes smaller as $n$ is decreased (i.e. strong shear-thinning effects) above a critical draw ratio, but surprisingly the opposite is true below this critical draw ratio. We determine an accurate estimate of the critical draw ratio and also discuss how inertia affects this process. We further show that the dynamics of hole closure is dominated by a different limit, and we determine the asymptotic forms of the hole closure process for shear-thinning and shear-thickening fluids with inertia. A linear instability analysis is conducted to predict the onset of draw resonance. We show that increased shear thinning, surface tension and inlet hole size all act to destabilise the flow. We also show that increasing shear-thinning effects reduce the critical Reynolds number required for unconditional stability. Our study provides valuable insights into the drawing process and its dependence on the physical effects.

Optimization design and performance study of magnesium alloy vascular clamp

Purpose: This study investigates the effects of varying inner diameter of a vascular clamp made from an Mg–Nd–Zn–Zr alloy on its functional performance. The primary objectives are to optimize the clamp’s structure, assess its performance across different inner diameters, and ultimately determine the optimal configuration. Methods: We developed a V-shaped vascular clamp equipped with a locking mechanism and transverse teeth. The study involved comparing vascular clamps with various inner diameters (0.35 mm, 0.4 mm, 0.5 mm and 0.6 mm, denoted as R0.35, R0.4, R0.5 and R0.6, respectively), achieved by modifying the clamp design. Finite element analysis simulated the closure process of these clamps, both with and without blood vessels, to analyze stress and strain distribution. Subsequently, we manufactured a clamp with the optimized design and conducted performance evaluations, including a closing strength test and an in vitro immersion test. Results: Among the tested vascular clamps, the R0.5 clamp demonstrated the lowest strain (0.50798) and minimal stress on blood vessels (0.7629 MPa). Notably, the R0.5 clamp remained intact during clamping fracture experiments and demonstrated a maximum closing force of 334.98±15.4 mmHg. Regarding corrosion resistance, the clamped position showed a higher corrosion rate (0.179±0.00551 mg.cm-2.day-1) compared to the open clamp (0.161±0.00306 mg.cm-2.day-1). Conclusion: The R0.5 clamp demonstrated superior performance in finite element analysis, showing effective vascular closure, strong clamping force, and uniform corrosion behavior. Overall, these results highlight its potential as an effective tool for vascular closure.

Combining traditional and novel techniques to increase our understanding of the lock-in depth of atmospheric gases in polar ice cores – results from the EastGRIP region

Abstract. We investigate the lock-in zone (LIZ) of the East Greenland Ice Core Project (EastGRIP) region, northeastern Greenland, in detail. We present results from the firn air-pumping campaign of the S6 borehole, forward modeling, and a novel technique for finding the lock-in depth (LID, the top of the LIZ) based on the visual stratigraphy of the EastGRIP ice core. The findings in this work help to deepen our knowledge of how atmospheric gases are trapped in ice cores. CO2, δ15N, and CH4 data suggest that the LID lies around 58 to 61 m depth. With the pixel value intensity and bright-spot analysis based on visual stratigraphy, we can pinpoint a change in ice properties to exactly 58.3 m depth, which we define as the optical lock-in depth (OLID). This visual change in ice properties is caused by the formation of rounded and enclosed air bubbles that alter the measured refraction of the light pathways. The results for the LID and OLID agree accurately on the depth. We furthermore use the visual stratigraphy images to obtain information on the sharpness of the open- to closed-porosity transition. Combining traditional methods with the independent optical method presented here, we can now better constrain the bubble closure processes in polar firn.

Revealing complex subsurface dynamics with continuous seismic monitoring: Observations using distributed acoustic sensing and surface orbital vibrators during hydraulic fracturing

Understanding hydraulic fracturing is crucial to improving the stimulation of unconventional reservoirs and increasing fluid production. This study develops a novel seismic monitoring technology using distributed acoustic sensing (DAS) and surface orbital vibrators (SOV) to capture fracture seismic response and mechanical properties at high temporal intervals. We analyze continuous time-lapse vertical seismic profiling (VSP) data acquired every hour during the first nine days of treatment of an unconventional reservoir in the Austin Chalk/Eagle Field Laboratory. The VSP data contain clear seismic signals scattered from the activated fractures. The spatiotemporal changes of the fracture reflectivity revealed by the SOV/DAS data correlate well with the observations of fracture locations inferred from low-frequency DAS data. These results capture the fracture opening and closure processes, as well as highlight potential prestage activations of the fractures due to hydraulic connectivity with preexisting fracture systems. Therefore, analysis of the presented data set provides a unique opportunity to understand fracture initiation and subsequent evolution, not only in the context of unconventional resources but also in enhanced geothermal systems.

Enhancing wound healing with zinc and silver nanocomposites synthesized with β-lactoglobulin: antimicrobial properties, collagen deposition, and systemic effects in a C57BL/6J mouse model

This study explores the potential of zinc and silver nanocomposites, synthesized with β-lactoglobulin, a whey protein, in promoting wound healing, using the C57BL/6J mouse model. Our research is distinct in its dual focus: assessing the antimicrobial efficacy of these nanocomposites and their impact on wound healing processes. The antimicrobial properties were investigated through minimum inhibitory concentration (MIC) assessments and colony-forming unit (CFU) tests, providing insights into their effectiveness against wound-associated microorganisms. Notably, the formulation's effective antibacterial concentration did not exhibit toxicity to mouse fibroblasts. A key aspect of our methodology involved the use of a stereoscopic microscope for detailed monitoring of the wound closure process. Additionally, the distribution and potential systemic effects of the zinc and silver ions were analyzed using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). This analysis was crucial in evaluating metal ion absorption through the wound site and estimating any toxic effects on the body. Our findings are particularly significant in the field of regenerative medicine. Transmission electron microscopy (TEM) revealed that the tested nanocomposites notably enhanced collagen deposition, a vital component in the wound healing process. Furthermore, a reduction in glycogen levels in hepatocytes was observed following treatment with these metal-protein dressings. This novel finding warrants further investigation. Overall, our findings highlight the diverse roles of zinc and silver nanocomposites in wound healing. This study not only contributes to our understanding of metal-protein complexes in tissue regeneration but also opens new avenues for research into the delivery mechanisms of such treatments for hard-to-heal wounds.

Climate changes at mine closure: a systematic review

This systematic review addresses the implications of climate change on mine closure processes, aiming to identify, analyze, and synthesize recent literature on how climate change influences the rehabilitation of mined areas, environmental risks, the safety of remaining structures, and the long-term sustainability of closure projects. Through a methodology of selecting scientific articles, articles published between 2020 and 2024 found in the Capes/CAfe database were analyzed. The analysis covered the climatic impacts on increasing temperatures and changes in precipitation patterns in relation to soil erosion, water management, and revegetation in mine closure processes. The results highlight challenges and opportunities arising from extreme weather events, which compromise the stability of mine structures, and the noted absence of Emergency Action Plans for dealing with extreme events, which hinders decision-making and the implementation of control measures. Recommendations include the development of adaptive practices and the incorporation of advanced environmental monitoring to mitigate risks and promote sustainability in mine closure, as well as being essential to increase environmental resilience.

How do multiple active cellular forces co-regulate wound shape evolution?

Wound closure is a fundamental procedure in many physiological and pathological processes, driven by multiple active cellular forces. In the closure process the wound shape can evolve into round, oval, or slit. However, the underlying mechanisms that determine the mechanical strategies of wound shape evolution are unclear. To understand how these active forces co-regulate wound shapes, we constructed a novel complex variable method-based mechanical model and obtained the stress field and free energy of cell layer with arbitrary wound shape. Our results revealed that there was a stress-driven cell polarization and arrangement around the wound under the cooperative regulation of the tissue pretension, cell protrusion stress and actomyosin ring tension that drove the direction of cell polarization and arrangement for the wound closure. In addition, a 3D phase diagram was obtained from minimizing the free energy of the cell layer that illustrates how the different active cellular forces co-regulate the wound shape evolution. In general, large cellular protrusion induces the evolution of the wound toward slit shape, and strong and medium contractions of the actomyosin ring correspond to the evolution toward oval shape and round shape, respectively. This study reveals a critical mechanism by which living organisms actively control complex processes via the coordination of multiple active cellular forces in tissue repair and development.

Hydraulic Fracture Closure Detection Techniques: A Comprehensive Review

This study reviews methods for detecting fracture closure pressure in both unconventional and conventional reservoirs using mathematical models and fluid flow equations. It evaluates techniques such as the Nolte method, tangent method, and compliance method. The investigation relies on observing changes in fluid flow regimes from preclosure to postclosure using fluid flow equations to examine the postclosure flow regime effect on the G function. Reverse calculations model pressure decline across synthesized flow regimes, facilitating a detailed investigation of the closure process. The analysis reveals that the tangent method is sensitive to postclosure fluid flow, while the compliance method is less effective in reservoirs with significant tortuosity or natural fractures. This paper recommends assessing natural fractures’ characteristics and permeability to identify the source of leak-off before selecting a technique. It proposes integrating various methods to comprehensively understand subsurface formations, combining their strengths for accurate fracture closure identification and a better understanding of subsurface formations. The new proposed workflow employs the continuous wavelet transform (CWT) technique for fracture closure detection, avoiding physical model preassumptions or simplifications to confirm the results. This approach offers guidance on selecting appropriate methods by integrating different techniques.

Characterization of urethra closure in female neonatal mice at histological and molecular levels.

Female hypospadias is a little-known and poorly studied birth defect. This research establishes an anatomical and molecular foundation for future research to investigate the origins of this defect. Hypospadias is a congenital anomaly of the external genitalia where the urethra does not properly close. In humans, hypospadias is mostly reported in male newborns, whereas in females hypospadias is rare, although it is generally considered to be under-reported. Improper urethra closure in the female genitalia can cause recurrent genitourinary tract infections and infertility. In mice, female hypospadias was induced by exposure to exogenous estrogenic compounds. Aside from the link between estrogen exposure and female hypospadias, the process of female urethra closure is largely unstudied, with the precise timing of urethra closure and associated molecular mechanisms remaining poorly understood. To address this gap, we determined when urethra closure occurs and identified gene expression patterns during the process of urethra closure in female neonatal mice from postnatal day (PND) 5 to 10. Using whole mount imaging and histology, we discovered that the initiation of urethra closure begins at PND7, and urethra closure is fully completed by PND10. To identify the genes associated with urethra closure, we conducted bulk RNA sequencing on female external genitalia prior to and after urethra closure. Gene ontology analyses revealed an increase in steroidogenic gene expression (Star, Hsd3b6, and Cyp17a1) during urethra closure, suggesting that the female genitalia locally produce steroids which could facilitate steroid signaling within the genitalia. With this study, we establish an anatomical timeline of female urethra closure and hypothesize a paracrine steroid signaling mechanism of urethra closure. These observations provide entry points to aid in further understanding external genital abnormalities, like hypospadias, in females.