Dominant Structure Research Articles

Precursory Analysis Ensemble Spread Signals That Foreshadow Stratospheric Sudden Warmings

Abstract This study conducts a thorough investigation into the behaviors of analysis ensemble spreads linked to stratospheric sudden warming (SSW) events. A stratosphere-resolving ensemble data assimilation system is used here to document the evolution of analysis spread leading up to a pair of warming events. Precursory signals of the increased ensemble spreads were found a few days prior to two SSW events that occurred during December 2018 and August–September 2019 in the Northern and Southern Hemispheres, respectively. The signals appeared in the upper and middle stratosphere and did not appear at lower heights. When the signals appeared, it was found that both tendency by forecast and analysis increment in a forecast-analysis (data assimilation) cycle simultaneously became large. An empirical orthogonal function analysis showed that the dominant structures of the precursory signals were equivalent barotropic and were 90° out-of-phase with the analysis ensemble-mean field. Over the same period, the upper and middle stratosphere became more susceptible to barotropic instability than in their previous states. We conclude that the differing growth of barotropically unstable modes across ensemble members can amplify spread during the lead-up to SSW events. Significance Statement Winds in the winter stratospheric polar vortex are typically westerly. Occasionally, however, warming over the pole leads to a reversal of the flow through a process known as stratospheric sudden warming. These events are difficult to predict even in state-of-the-art analysis and forecasting systems. In this study, we identify a precursor signal in the form of increased ensemble spread that appears to originate from differing realizations of growing barotropic modes across the ensemble. This signal could serve as a useful forecasting tool by enhancing situational awareness in the lead-up to potential stratospheric sudden warming events.

Hydrogen bonding switched symmetric and anti-symmetric vibrations SRS of –CH2 in aqueous DEG solution

The symmetric and anti-symmetric stretching vibrations of C–H extensively exist in organic molecules, which constantly arise together in Raman spectroscopy. In this study, a method was presented to switch stimulated Raman scattering peak from symmetric vibrations (2870 cm−1) to anti-symmetric vibrations (2924 cm−1) of –CH2 by regulating the hydrogen bonding (HB) associated through intermolecular and intramolecular in diethylene glycol (DEG) molecules. Such dominant association structure can be converted from DEG-DEG to DEG-H2O in the aqueous DEG solutions. The interaction between H2O and DEG was investigated through the density functional theory calculation. The changes in intermolecular HB have effects on the intramolecular vibrational modes by the intermolecular forces and symmetry of the DEG molecule. This study has exciting potential prospect and can be extended to other mixing solutions.

Analysis of the Dominant Structures of an Impinging Round Jet at M=0.9

Large-eddy simulation of subsonic round jet impinging on a flat circular plate is performed at Mach number 0.9 and Reynolds number 25,000, based on the diameter and centerline velocity of the jet for two impingement distances h of 6r0 and 8r0 using high-order compact finite difference scheme. The complex flow phenomena associated with the impinging jet flowfield are studied. The power spectral density (PSD) of instantaneous pressure reveals a discrete impingement tone. Dynamic mode decomposition (DMD) of the velocity and pressure is also done for both cases to extract the most dominant modes of the flow. The fundamental impingement tone frequency obtained from the PSD of pressure is identical to that of the first dominant pressure mode obtained from DMD. Both axisymmetric and semihelical modes are present for the h=8r0 case, but only axisymmetric modes are there in the h=6r0 case, and it is noted that the modes corresponding to the fundamental tone have an axisymmetric structure. Also, one dominant mode showing the wall jet structures denoting the liftoff of fluid from the wall after impingement at some radial distance away from the stagnation region is present in both impingement distance cases.

Tuning dynamic mechanical properties of Cu50Zr50 nanoglasses/ nanopolycrystalline Cu composites investigated by molecular dynamics simulation

Nanoglasses/nanopolycrystalline (NGNP) composites have emerged as a promising approach to balance the strength and plasticity of metallic glasses. Herein, the shock responses of five Cu50Zr50 NGNP composites are investigated via molecular dynamics simulations under a shock velocity of 0.5 to 2.0 km/s. The simulation results reveal that with an increasing fraction of nanocrystalline grains, the Hugoniot pressure, shear stress, and spall strength of the composites are enhanced, while their atomic strain decreases under shock loading. Additionally, due to the dominant structure type changes from an amorphous structure to a crystal structure, the deformation mechanism transforms from the growth of shear transformation zones to dislocation slip, phase transition, and amorphization as the impact velocity increases. In terms of the spallation, the spall strength of the composites rises initially and then declines due to the competing mechanisms of strain rate hardening and shock-induced softening.

The Secondary Structure of Potato Spindle Tuber Viroid Determines Its Infectivity in Nicotiana benthamiana.

The function of RNAs is determined by their structure. However, studying the relationship between RNA structure and function often requires altering RNA sequences to modify the structures, which leads to the neglect of the importance of RNA sequences themselves. In our research, we utilized potato spindle tuber viroid (PSTVd), a circular-form non-coding infectious RNA, as a model with which to investigate the role of a specific rod-like structure in RNA function. By generating linear RNA transcripts with different start sites, we established 12 PSTVd forms with different secondary structures while maintaining the same sequence. The RNA secondary structures were predicted using the mfold tool and validated through native PAGE gel electrophoresis after in vitro RNA folding. Analysis using plant infection assays revealed that the formation of a correct rod-like structure is crucial for the successful infection of PSTVd. Interestingly, the inability of PSTVd forms with non-rod-like structures to infect plants could be partially compensated by increasing the amount of linear viroid RNA transcripts, suggesting the existence of additional RNA secondary structures, such as the correct rod-like structure, alongside the dominant structure in the RNA inoculum of these forms. Our study demonstrates the critical role of RNA secondary structures in determining the function of infectious RNAs.

Structural and metamorphic evolution of a subducted passive margin: insights from the Briançonnais nappes of the Western Alps (Ubaye–Maira valleys, France–Italy)

This contribution analyses the structural architecture and tectono-metamorphic evolution of Briançonnais units in the southern French-Italian Western Alps. The studied area extends from a virtually non-metamorphic area adjacent to the Helvetic-Dauphinois External Domain in the west to the Monviso-Queyras ocean-derived units in the east, where metamorphism increases up to eclogite-facies. Mapping at the scale 1:10.000 of a mountainous part of the Ubaye-Maira transect was performed, which portrays in detail the Briançonnais units over ~ 100 km2. The lithologies include meta-andesite, meta-siliciclastics, marbles, turbiditic calcschists and flysch whose age spans from Late Carboniferous to Eocene. Metamorphism is low-grade greenschist-facies in the west but reaches the blueschist-facies to the east. Structures related to four phases of deformation are identified. The first two generations of structures (D1–D2), related to the original top-to-the-west nappe stacking, are associated with conditions close to the peak of Alpine metamorphism. Previous tectonic surfaces are transposed by the dominant deformation structures (D3), developed under retrograde/decompression conditions. This D3 corresponds to a backfolding and back-thrusting event with a top-to-the-E transport. A fourth phase (D4) developed during late low-grade metamorphic conditions and deforms the previous surfaces by locally developing a crenulation cleavage, followed by brittle tectonics. An updated metamorphic map is presented, backed on published estimates and new thermometric data obtained by Raman Spectroscopy of Carbonaceous Material (RSCM). The TRSCM values range from ~ 295 °C to > 350 °C, moving from the most external Briançonnais unit to the internal Queyras “Schistes Lustrés” units. Suspected Upper Cretaceous palaeofaults have been documented, allowing us to group the classic Aiguille de Mary and Ceillac (sub-) units into a single tectonic unit, here referred to as Maurin unit. The palaeogeographical reconstruction of the evolution of the studied transect highlights the importance of the Marinet and Maurin axial units in the feeding of the Late Cretaceous-Eocene breccias deposited on the more internal Acceglio-type units.

Processing and characterization of TiNbMoTaW refractory high entropy alloy by mechanical alloying

Refractory High Entropy Alloys (RHEAs) are a new class of alloys that have attractive properties suited for high-temperature applications. An equiatomic combination of the elements Ti, Nb, Mo, Ta, and W has been processed by mechanical alloying (MA) route to yield TiNbMoTaW RHEA powder. Structural analysis of RHEA powder obtained after 100 h of mechanical milling, indicated the formation of a single-phase solid solution with a body-centered cubic (BCC) structure and has a lattice constant of 3.1645 Å. CALPHAD modeling of TiNbMoTaW RHEA was carried out to understand the effect of phase changes with respect to temperature. RHEA was found to be thermally stable at elevated temperatures with a dominant BCC structure, which highlights its potential in high-temperature engineering applications.

Designer biochar with specific functionalities for the sustainable mining of invaluable metals from sea water: Performance assessment, mechanism insights and cost benefit analysis

Resource efficiency and cleaner production are an integral component of sustainable development. The present research addresses three contemporary issues. Firstly, quest for a greener alterative to land based mining-seawater, secondly, translation of renewable biowastes into carbon negative biochar and thirdly, synthesis of organic salts of metals directly from metal laded biochar. Sea water is an untapped source of invaluable elements leading to rising momentum for various new technologies. Herein, neem cake is tailored specifically for selective recovery of magnesium and strontium ions from simulated sea water in both batch and continuous systems. Magnesium selective biochar is prepared by insitu pyrolysis at 700℃ using sodium bicarbonate and urea as green porogen and nitrogen source whereas strontium selective biochar is prepared by direct pyrolysis at 700℃ followed by encapsulating alginate microspheres within the biochar lattice. Batch studies revealed the maximum adsorption capacities and removal efficiencies of 34.08 mg/g and 95 % for strontium(S-BC) and 40.2 mg/g and 98 % for magnesium(M−BC). The analytics reveals biochars as fine-tuned mesoporous carbon dominant structure with several N and O functionalities suggesting complexation, H-bonding as the adsorption mechanism. The Sips and PNO models surpassed all isotherm and kinetic models and well describes the process kinetics as chemisorption along with film diffusion as main contributors respectively. In column studies, effect of different process parameters is investigated and it is observed that experimental data corelates well with the BDST model. Moreover, scale up approach is employed to predict large scale design parameters. Lastly, citric acid as a green chelating agent is utilized to recover metal ions in the form of citrates and regenerate spent biosorbent along with detailed cost benefit analysis, thereby endorsing the circular economy approach.

Population of Collembola of bog ecosystems of the ukrainian part of the International Biosphere Reserve «Roztochia»

A comparative analysis of the taxonomic and ecological structure of bog collembolan taxocenes of IBR "Roztochia" was carried out. 67 species of Сollembola belonging to 43 genera and 12 families were found on the studied territory. The representation of the rare element of collembolofauna (its uniqueness) is 14.9%. Three species are new to the collembolofauna of Ukraine (Cryptonura kühnelti, Heteromurus sexoculatus, Isotomurus fucicolus) and one new species is from the continental part of Ukraine (Tetracanthella proxima). From 1 to 13 species of Сollembola were found at the level of point alpha diversity, and 5–29 species of coenotic alpha diversity, which indicates a small capacity of the soil environment for Сollembola in bog ecosystems, сompared to forest and meadow ecosystems. The investigated bog Collembola taxocenes are characterized by small and average population density indicators, from 0.25 to 9.1 thousand spec./m2. It was found that the structure of dominance, spectra of life forms and biotope groups of the studied taxocenes have their own specificity, due to local edaphic conditions. The analysis of the ecological structure showed that, in terms of species richness, complexes of hygro-mesophilic (31.3% of the total species richness), mesophilic (22.4%) and xeroresistant forms (20.9%) prevail in bog taxocenes of collembola. The studied taxocenes include nine biotope groups of species. The biotope groups of forest species (28,9%) and species that differentiate the bog type of ecosystems (bog, near-water, meadow- and forest-bog species) prevails. The share of representatives of the second group in the studied taxocenes is 14.9% of the total species diversity and 29.5% of the total abundance. It was established that a mixed collembolan taxocene is formed in bog ecosystems, where none of the biotope groups reaches 40% of the total abundance.

Taxonomic and ecological structure of oribatid mites (Acari: Oribatida) of mesophilic grasslands on the Transcarpathian lowland

The article analyzes the taxonomic diversity, dominance structure, spectra of morpho-ecological types, biotope complexes and groups of oribatid mites of mesophilic grasslands on Transcarpathian lowland. Prior to our works, there were almost no studies of the oribatid communities of the studied area. The research plots located on the sorrounding areas of the city of Mukachevo and the village of Kalnyk of the Mukachevo district. Soil samples selected for 2013-2014. The geographical coordinates of the first meadow are: 48º22.79' N, 22º40.14' E, and the second one is 48º30.86' N, 22º34.65' E. The total area of the first biotope is 0.45, and the second is 37.5 hectares. In relation to the humidity of the substrate, this type of biotope is characterized by mesophilic conditions. Extraction of mites from soil was carried out using Tullgren funnel method. Permanent preparations were prepared. Identification of the specimens was carried out using a microscope (Olympus BX 51). Oribatid mites of the investigated mesophilic grasslands are represented by 26 species from 22 genera and 16 families. The families Oppiidae and Scheloribatidae are the most represented. The average density of oribatid mites of the mesophilic grasslands on Transcarpathian lowland has relatively small values (3.7 thousand specimens per m2). The dominant species include Punctoribates punctum (C. L. Koch, 1839) and Ceratozetes mediocris Berlese, 1908. They together make up 44% of the total density of oribatids. Margalef, Menkhinik, Simpson, Shannon and Berger-Parker indices were calculated. 10 morpho-ecological types of oribatid mites were found on mesophilic grasslands. Oribatids - inhabitants of small soil crevices – predominate. Representatives of five biotope complexes (euryoecic, hygrophilous, hygro-mesophilous, mesophilous and xerophilous) and four biotope groups (eurytopic, forest, forest-meadow, meadow) were identified in the structure of ecological groups of Oribatids. Mesophilous and meadow species of oribatid mites have the largest share.

First results from the interaction between hydroxyl radicals and condensed water droplets: A spin-polarized DFT-MD study

The formation of clouds results from condensation of water vapor into liquid water droplets. These water droplets form on the surface of tiny particles that are suspended in the air, like dust. Atmospheric chemistry relies heavily on the hydroxyl radical (OH*), which is highly reactive and prone to combining with hydrogen atoms in other compounds. Despite previous studies concerning liquid, solid, and gas phase interactions, how hydroxyl radicals interact with condensed water droplets is still unknown. OH*-condensed droplet interactions show unique behavior, according to our studies. Several hydrogen transfers were detected during the interaction process. It takes approximately 3.5 kcal/mol of energy to initiate hydrogen transfer. Moreover, we revealed the dominant structures of hydrated radicals during the mobility of OH* into condensed droplets using Born–Oppenheimer molecular dynamics simulations. In contrast to our previous studies, the hemibond doesn't significantly affect the stability of OH*(H2O)n structures in condensed droplets. Our results showed that condensed droplets hinder the mobility of OH*, causing its diffusion coefficient to decrease. Moreover, several analyses were carried out to investigate condensed droplet surfaces, bonding patterns, and the position of OH* in conjunction with water molecules, including mobility analyses, radial distribution functions, coordination analyses, and population analyses.

A Postmodern Psychoanalytic Critique of Narrative Disruptions and Subversions in Dalit and Post-apocalyptic Narratives: A Comparative Study

This research study investigates narrative disruptions and subversions in Dalit and post-apocalyptic literature using a postmodern psychoanalytic methodology. Drawing on the concepts of Jacques Lacan and Homi K. Bhabha, the research argues that these literary genres use language and plot to subvert and disrupt dominant power structures, social hierarchies and hegemonic discourses. The study examines a few works of Dalit and post-apocalyptic fiction to show how both genres use narrative methods such as fragmentation, irony, parody and subversion to question established standards of representation and disclose the traumas and disjunctions of the oppressed. The voice of the oppressed is explicit through the analysis of the selected texts.

A genetic algorithm with resource buffers for the resource-constrained multi-project scheduling problem

In this study, we compose a new metaheuristic algorithm for solving the resource-constrained multi-project scheduling problem. Our approach is based on a general metaheuristic strategy which incorporates two resource-buffered scheduling tactics. We build on the most effective evolutionary operators and other well-known scheduling methods to create a novel genetic algorithm with resource buffers. We test our algorithm on a large benchmark dataset and compare its performance to ten existing metaheuristic algorithms. Our results show that our algorithm can generate new best-known solutions for about 20% of the test instances, depending on the optimisation criterion and due date. In some cases, our algorithm outperforms all other available methods combined. Finally, we introduce a new schedule metric that can quantitatively measure the dominant structure of a solution, and use it to analyse the differences between the best solutions for different objectives, due dates, and instance parameters.

Warrior Women: Indigenous Women, Gender Relations, and Sexual Politics within the American Indian Movement and at Wounded Knee

The main purpose of this article is to describe and analyze Indigenous women’sparticipation in the prolonged takeover of Wounded Knee in 1973. Indigenouswomen’s grassroots activism was fundamental for sustaining and keeping the occu-pation alive, yet their contributions were largely eclipsed by the actions of theirmedia-savvy, male comrades-in-arms. What is more important, Indigenous women inthe American Indian Movement (AIM) frequently claimed that they were in a state of“double oppression” or “double colonization”—first, through colonial domination andracial inequality, and second, through male privilege and female subordination—itself,part of the legacy of colonization and the imposition of dominant white patriarchalmasculinity.2 Nationalist struggles such as that of the anticolonial AIM tend to repli-cate the very structures of male dominance that they struggle against. While womenhave been included in public discourse, they have been largely left out of politicaldecision-making.3At Wounded Knee, Indigenous women took on a series of interrelated roles andresponsibilities that kept the occupation alive. Indigenous women skillfully renegoti-ated their gendered position of power within the masculinist organization, constructingfemininities that shifted between domesticated motherhood and female comrades-in-arms. In so doing, they both reaffirmed and challenged sexist and chauvinist attitudes within AIM. They were well known as long-standing community organizers, andtheir active participation at the Wounded Knee takeover was an indication of female empowerment. 

The Work-Life Experiences of Black African Immigrant Nurses in Vancouver: Everyday Racisms and Acts of Resistance

This analysis is based on semi-structured interviews examining the work–life experiences of Black African immigrant nurses in Vancouver, British Columbia, conducted from June 2013 to June 2014. The article argues that nurses experience systemic barriers in which their sense of Canadian belonging and professionalism are called into question by patients, colleagues, and managers. Using the framing device of everyday racism, findings suggest that nurses navigate and counter these socio-cultural barriers by repurposing their daily actions into powerful subversive acts of resistance. The article uses the concept of everyday racism to relate the day-to-day experiences recounted by Black nurses to the larger macrostructural contexts that define the intersecting inequalities they describe. Grounded in Black Canadian feminist theory, this article contends that the lives of Black nurses offer critical insights to challenge structures of dominance. This article builds on existing scholarship discussing experiences of racism among Black and largely Caribbean nurses in Canada. The contribution is important because it offers the opportunity to analyze the lived realities of continental African nurses in Vancouver, in the historical context of a racialized Canadian state policy.

Exploring the structural and mechanical properties of single-Component Mo metallic glasses

In this paper, we employed molecular dynamics (MD) simulations to investigate how the cooling rate affects the structural and mechanical properties of molybdenum monoatomic glasses (Mo-MG). We also examined the influence of cooling rates on the glass transition temperature, showing a decrease as the cooling rates decreased. The analysis of structural properties using techniques such as radial distribution function (RDF), Voronoi tessellation analysis, and common neighbor analysis (CNA) revealed that the cooling rates have a significant impact on the local structure of Mo-MG. The RDF function displayed a splitting in the second peak, indicating the formation of a super-cooled liquid state. The CNA analysis identified the most dominant local structures as icosahedral configurations, specifically ⟨0,1,10,2⟩, ⟨0,0,12,0⟩, and ⟨0,0,12,2⟩. The mechanical properties were calculated using the Virial theorem implemented in the LAMMPS simulation software. The results indicated that the ultimate strengths of Mo-MG were comparable to those of crystalline molybdenum. However, the ultimate strength decreased with increasing cooling rate, indicating that higher cooling rates result in weaker Mo-MG samples. A similar trend was observed for Young's modulus, where increasing cooling rates led to a decrease in the stiffness of the formed Mo-MG.

Flow-induced noise from a seal-vibrissa-shaped cylinder

Inspired by the special structure of seal vibrissae and their ability to effectively suppress vortex-induced vibrations, this paper studies the characteristics of flow and aerodynamic noise generated around a seal-vibrissa-shaped cylinder at a Reynolds number (based on the hydrodynamic diameter and freestream velocity) of 6 × 104 using the delayed detached-eddy simulation model combined with the acoustic analogy approach. The far-field aerodynamic noise has also been measured at Reynolds numbers of 6 × 104∼1.2 × 105 in an anechoic wind tunnel to compare the seal-vibrissa-shaped cylinder with cylindrical and elliptical bars of the same characteristic dimensions. The calculated spectra of aerodynamic noise agree well with the wind tunnel measurements, verifying the accuracy of the numerical simulations. It is found that the three-dimensional flow separations introduced by the alternative saddle and nodal planes of the seal-vibrissa-shaped cylinder inhibit shear layer interactions and reduce the spanwise coherence, resulting in a wake with no dominant coherent structures and thus suppressing pressure fluctuations on the solid surfaces. The configuration of seal-vibrissa-shaped cylinder eliminates the regular Kármán vortex street which generally occurs in a cylinder wake, and consequently inhibits the tonal peak in the aerodynamic noise. The sound pressure level is also reduced in most frequencies. The consistency of the normalized spectra of the far-field aerodynamic noise and the vortex shedding frequency at different inflow speeds demonstrates the high accuracy of the anechoic wind tunnel measurements. Compared with cylinders with circular or elliptical cross sections, the seal-vibrissa-shaped cylinder effectively reduces the flow-induced noise by, respectively, 13 dB or 11 dB for a far-field receiver of 90° at Reynolds number of 6 × 104, showing great potential in reducing aerodynamic noise.

Tetracalcium Phosphate Biocement Hardened with a Mixture of Phytic Acid–Phytase in the Healing Process of Osteochondral Defects in Sheep

Hyaline articular cartilage has unique physiological, biological, and biomechanical properties with very limited self-healing ability, which makes the process of cartilage regeneration extremely difficult. Therefore, research is currently focused on finding new and potentially better treatment options. The main objective of this in vivo study was to evaluate a novel biocement CX consisting of tetracalcium phosphate–monetit biocement hardened with a phytic acid–phytase mixture for the regeneration of osteochondral defects in sheep. The results were compared with tetracalcium phosphate–monetit biocement with classic fast-setting cement systems and untreated defects. After 6 months, the animals were sacrificed, and the samples were evaluated using macroscopic and histologic methods as well as X-ray, CT, and MR-imaging techniques. In contrast to the formation of fibrous or fibrocartilaginous tissue on the untreated side, treatment with biocements resulted in the formation of tissue with a dominant hyaline cartilage structure, although fine fibres were present (p < 0.001). There were no signs of pathomorphological changes or inflammation. Continuous formation of subchondral bone and hyaline cartilage layers was present even though residual biocement was observed in the trabecular bone. We consider biocement CX to be highly biocompatible and suitable for the treatment of osteochondral defects.

Challenging ungrievability for people missing at sea. Search infrastructures, spaces of public mourning, and claims for justice

ABSTRACT Since the so-called refugee crisis, the central Mediterranean Sea has been identified as the deadliest border in the world. As the border studies debate has shown, these deaths reflect the structural violence of border regimes and demand due forms of political accountability and responsibility. However, dominant power structures differentially shape the visibility and grievability of those who are missing and dead at the border. Keeping this complexity as a background, and drawing on examples from Lampedusa and Tunisia, we investigate the politics of challenging Butler’s “ungrievability” – the lack of access to preconditions, spaces and times of private and public mourning and commemoration. We critically discuss the interplay between three components of this political arena: the search infrastructures of the missing and dead at sea; the creation of “spaces of commemoration” through place-making, time-marking and collective actions; the claims for justice and political accountability for those deaths.

Prefiguring Alternative Organizing: Confronting marginalization through projective cultural adjustment and tempered autonomy

In this paper, we examine community collectives – place-based, community-led initiatives for sustainable livelihood, as an alternative to the top-down, efficiency-driven economic model. Drawing on the theoretical framework of prefigurative organizing, we examined the strategies employed by community members in confronting entrenched inequalities and overcoming marginalization as they envision and engage in inclusive futures. We conducted a comparative case study of two exemplary community collectives in India that exhibited differences in the degrees of internal and external marginalization. We identified two key cross-cutting themes of prefigurative organizing: projective cultural adjustment – whether a community leverages their traditional culture or breaks away from it, and tempered autonomy – negotiating autonomy without overtly challenging dominant groups, and exercising self-imposed restraints to make independent decisions. We show how these two themes manifested across three key processes of prefigurative organizing: prefiguring self-governance; commoning; and cultivating discursive spaces. These findings help us theorize that in communities where the degree of internal marginalization is high due to persisting social hierarchies, breaking away from past discriminatory practices, incorporating suspension of consent in the decision-making process, and introducing multiple constructive works are essential components of prefigurative organizing. In communities where the degree of external marginalization is high, building on the past, incorporating refusal in decision-making, and introducing unified constructive work are important components of prefigurative organizing. We suggest that prefigurative organizing against the dominant power structure, whether within community social hierarchies or external exploitative political-economic structures, is based on selective and strategic engagement without seeking an exit, as exit might not be an option for place-based communities. We discuss the theoretical and practical implications of this research for alternative organizing and grand challenges.