Pre-existing Structures Research Articles

Bidirectional propagating brightenings in arch filament systems observed by Solar Orbiter/EUI

Arch filament systems (AFSs) are chromospheric and coronal manifestations of emerging magnetic flux. Using high spatial resolution observations taken at a high cadence by the Extreme Ultraviolet Imager (EUI) on board Solar Orbiter, we identified small-scale elongated brightenings within the AFSs. These brightenings appear as bidirectional flows along the threads of AFSs. For our study, we investigated the coordinated observations of the AFSs acquired by the EUI instrument and the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO) on 2022 March 4 and 17. We analyzed 15 bidirectional propagating brightenings from EUI 174 AA images. These brightenings reached propagating speeds of 100--150 km s$^ $. The event observed on March 17 exhibits blob-like structures, which may be signatures of plasmoids and due to magnetic reconnection. In this case, we also observed counterparts in the running difference slit-jaw images in the 1400 AA passbands taken by the Interface Region Imaging Spectrograph (IRIS). Most events show co-temporal intensity variations in all AIA EUV passbands. Together, this implies that these brightenings in the AFSs are dominated by emission from cool plasma with temperatures well below 1 MK. The Polarimetric and Helioseismic Imager (PHI) on board Solar Orbiter provides photospheric magnetograms at a similar spatial resolution as EUI and from the same viewing angle. The magnetograms taken by PHI show signatures of flux emergence beneath the brightenings. This suggests that the events in the AFSs are triggered by magnetic reconnection that may occur between the newly emerging magnetic flux and the preexisting magnetic field structures in the middle of the AFSs. This would also give a natural explanation for the bidirectional propagation of the brightenings near the apex of the AFSs. The interaction of the preexisting field and the emerging flux may be important for mass and energy transfer within the AFSs.

DESI Massive Poststarburst Galaxies at z ∼ 1.2 Have Compact Structures and Dense Cores

Poststarburst galaxies (PSBs) are young quiescent galaxies that have recently experienced a rapid decrease in star formation, allowing us to probe the fast-quenching period of galaxy evolution. In this work, we obtained Hubble Space Telescope (HST)/WFC3 F110W imaging to measure the sizes of 171 massive ( log(M*/M⊙)∼11) spectroscopically identified PSBs at 1 < z 1.3 selected from the DESI Survey Validation luminous red galaxy sample. This statistical sample constitutes an order of magnitude increase from the ∼20 PSBs with space-based imaging and deep spectroscopy. We perform structural fitting of the target galaxies with pysersic and compare them to quiescent and star-forming galaxies in the 3D-HST survey. We find that these PSBs are more compact than the general population of quiescent galaxies, lying systematically ∼0.1 dex below the established size–mass relation. However, their central surface mass densities are similar to those of their quiescent counterparts ( log(Σ1kpc/(M⊙kpc−2))∼10.1 ). These findings are easily reconciled by later ex situ growth via minor mergers or a slight progenitor bias. These PSBs are round in projection (b/a median ∼ 0.8), suggesting that they are primarily spheroids, not disks, in 3D. We find no correlation between the time since quenching and light-weighted PSB sizes or central densities. This disfavors apparent structural growth due to the fading of centralized starbursts in this galaxy population. Instead, we posit that the fast quenching of massive galaxies at this epoch occurs preferentially in galaxies with preexisting compact structures.

Cancer Vaccines: Recent Insights and Future Directions

The field of cancer immunotherapy has seen incredible advancements in the past decades. mRNA-based cancer vaccines generating de novo T cell responses, particularly against tumor-specific antigens (TSAs), have demonstrated promising clinical outcomes and overcome diverse challenges. Despite the high potential of neoantigens to provide personalized immunotherapies through their tumor specificity and immunogenicity, challenges related to the scarcity of immunogenic neoepitopes have prompted continuous research towards finding new tumor-associated antigens (TAAs) and broader therapeutic frameworks, which may now learn from the genuine successes obtained with neoantigens. As an example, human endogenous retroviruses (HERVs) have emerged as potential alternatives to tumor neoantigens due to their high tumoral expression and ability to elicit both T cell reactivity and B cell responses associated with the efficacy of existing immunotherapies. This review aims to assess the status and limitations of TSA-directed mRNA cancer vaccines and the lessons that can be derived from these and checkpoint inhibitor studies to guide TAA vaccine development. We expect that shared B cell, CD4 and CD8 T cell antigen presentation will be key to stimulate continuous T cell expansion and efficacy for tumors that do not contain pre-existing tertiary lymphoid structures. When these structures are present in highly mutated tumors, the current checkpoint-based immunotherapies show efficacy even in immune privileged sites, and vaccines may hold the key to broaden efficacy to more tumor types and stages.

A meta-analysis of letter-sound integration: Assimilation and accommodation in the superior temporal gyrus.

Despite being a relatively new cultural phenomenon, the ability to perform letter-sound integration is readily acquired even though it has not had time to evolve in the brain. Leading theories of how the brain accommodates literacy acquisition include the neural recycling hypothesis and the assimilation-accommodation hypothesis. The neural recycling hypothesis proposes that a new cultural skill is developed by "invading" preexisting neural structures to support a similar cognitive function, while the assimilation-accommodation hypothesis holds that a new cognitive skill relies on direct invocation of preexisting systems (assimilation) and adds brain areas based on task requirements (accommodation). Both theories agree that letter-sound integration may be achieved by reusing pre-existing functionally similar neural bases, but differ in their proposals of how this occurs. We examined the evidence for each hypothesis by systematically comparing the similarities and differences between letter-sound integration and two other types of preexisting and functionally similar audiovisual (AV) processes, namely object-sound and speech-sound integration, by performing an activation likelihood estimation (ALE) meta-analysis. All three types of AV integration recruited the left posterior superior temporal gyrus (STG), while speech-sound integration additionally activated the bilateral middle STG and letter-sound integration directly invoked the AV areas involved in speech-sound integration. These findings suggest that letter-sound integration may reuse the STG for speech-sound and object-sound integration through an assimilation-accommodation mechanism.

Magma Degassing andGoldMineralizationinthe Alkaline Intrusion- HostedGiltEdgeGoldDeposit,NorthernBlackHills, SouthDakota,USA

Gold mineralization in the Gilt Edge deposit was closely associated with magmatic differentiation and the formation of a Tertiary alkaline intrusive complex within the Lead–Deadwood dome.. Fluid inclusions and trace element geochemistry were used to study fluid evolution and determine sources. Quartz disseminated in unaltered trachyte porphyry hosts two populations of primary inclusions: 1) hypersaline i S–L–V a red hematite crystal and 2) mixtures of L–V and V– L that record phase separation at ~700oC. Whereas samples of hydrothermal quartz collected from in ore zones within and beyond structures (e.g., fault and breccia zones) contain dominant populations of V–L and L–V inclusions, respectively. Mineralization in structures formed from complex fluids of magmatic origin based on inclusions containing five transparent salt crystals and opaque crystals with cubic and round habits that have homogenization temperatures (Th) 650oC and salinities 63 wt.% NaCl equiv. In contrast, broader areas of disseminated mineralization in argillized and propylitized rocks contain hydrothermal quartz hosting large populations of L–V inclusions with Th of 200o360oC and salinities of 10–30 wt.% NaCl equiv., which reflect fluid mixing. Trace element concentrations are significantly higher in samples from structures and define zones of near surface Ag–As–Zn–Pb and deep Au–W–Mo–Cu. Whereas low trace element concentrations characterize propylitized quartz trachyte porphyry, except for high concentrations of Sb and Hg that occur at depth and likely track the retreat of isotherms as the hydrothermal system collapsed. These data show that during differentiation in a deep magma chamber, volatile-rich low-density fluids were periodically degassed into preexisting structures that were reactivated. Gold deposition during four stages of mineralization likely occurred due to boiling, changes in oxygen fugacity, and fluid mixing.

Relocation of earthquake clusters show seismogenic transverse structures in the Inner Northern Apennines (Italy)

The Inner Northern Apennines (Italy) are a region with a dominant N-S to NNW-SSE fault system, but dissected and offset by several E-W to NE-SW trending structures and lineaments. The knowledge about the nature of these transverse structures, their origin, activity and role in current tectonic motions is limited and debated. To better establish the location, subsurface shape, and kinematics of faults related to the Livorno-Empoli lineament, one of the major transverse structures in the Northern Apennines, we analysed the seismicity in western Tuscany. In the Viareggio Basin we identified and relocated two distinct earthquake clusters as well as calculated 12 new focal mechanisms. The results show that the clusters consisted of several swarms from the years 2006, 2015, 2016 and 2021. The events had a depth between 2 and 15 km and were located along a NE-SW oriented, SE dipping fault system dissecting the Viareggio Basin. Focal mechanisms show oblique normal slip. We interpret the fault system to form a connection between the Viareggio Basin and the Lucca Basin to the east as well as continuing offshore. The results show that the transversal faults of the Inner Northern Apennines are seismogenic, with the length, position and onshore to offshore nature of the fault suggesting reactivation of pre-existing structures.

Structure and Evolution of Multi-Trend Faults in BZ19-6 Buried Hill of the Bohai Bay Basin, Eastern China

Defining the structure and evolution of multi-trend faults is critical for analyzing the accumulation of hydrocarbons in buried hills. Based on high-resolution seismic and drilling data, the structural characteristics and evolutionary mechanism of multi-trend faults were investigated in detail through the structural analysis theory and quantitative calculations of fault activity, allowing us to determine the implication that fault evolution exerts on hydrocarbon accumulation in the BZ19-6 buried hill. There are four kinds of strike faults developed on the buried hill: SN-, NNE-, NE–ENE-, and nearly EW-trending, which experienced the Mesozoic Indosinian, Yanshan, and Cenozoic Himalayan tectonic movements. During the Indosinian, the BZ19-6 was in a SN-oriented compressional setting, with active faults composed of SN-trending strike-slip faults (west branch of the Tanlu fault zone) and near EW-trending thrust faults (Zhang-peng fault zone). During the Yanshanian, the NNE-trending normal faults were formed under the WNW–ESE tensile stress field. Since the Himalayan period, the BZ19-6 buried hill has evolved into the rifting stage. In rifting stage Ⅰ, all of the multi-trend pre-existing faults were reactivated, and the EW-trending thrust faults became normal faults due to negative inversion. In rifting stage II, a large number of NE–ENE-trending normal faults were newly formed in the NW–SE-oriented extensional setting, which made the structure pattern more complicated. In rifting stage III, the buried hill entered the post-rift stage, with only part of the NNE- and NE–ENE-trending faults continuously active. Multi-trend faults are the result of the combination of various multi-phase stress fields and pre-existing structures, which have great influence on the formation of tectonic fractures and then control the distribution of high-quality reservoirs in buried hills. The fractures controlled by the NNE- and EW-trending faults have higher density and scale, and fractures controlled by NE–ENE trending faults have stronger connectivity and effectiveness. The superposition of multi-trend faults is the favorable distribution of high-quality reservoirs and the favorable accumulation area of hydrocarbon.

Upper mantle shear velocity structure of the Cathaysia Block and surrounding areas: New insight into deep geodynamics

The Cathaysia Block (CAB) and its surrounding areas experienced intensive magmatism and mineralization in the Yanshanian period (ca. 200–90 Ma), but their mechanism and deep geodynamics are still debated. In addition, the origin and structures of the Hainan mantle plume are still unclear. To resolve these issues and investigate the large-scale lithospheric thinning and extension in the eastern South China Block, we determine a detailed 3-D S-wave velocity (Vs) model down to 700 km depth by collecting 24,190 S-wave teleseismic data recorded at 164 permanent stations and 125 portable stations deployed in the CAB and surrounding areas. Our results show that high-Vs anomalies exist separately in the study volume. Two high-Vs anomalies appear in the shallow upper mantle and the mantle transition zone, which may reflect the present thin lithosphere and the stagnant Paleo-Pacific slab, respectively. Two other high-Vs anomalies exist in the upper mantle, which may reflect the detached lithosphere and subducting slabs. In contrast, low-Vs anomalies appear widely beneath the CAB, which reflect a tilting magmatic conduit beneath the Wuyishan metallogenic belt (WYMB) and magmatic chambers beneath the Nanling metallogenic belt (NLMB). In addition, our results show that the Hainan plume has a double-layered appearance. Combining our tomographic results with previous multidisciplinary findings, we consider that (1) the subduction and rollback of the Paleo-Pacific Plate may have played different roles in the Yanshanian mineralization of the WYMB and the NLMB; (2) the double-layered appearance of the Hainan plume may be formed due to the influence of plume self-evolution dynamics and pre-existing deep structures; and (3) lithospheric delamination triggered by gravity instability may have occurred beneath the Xuefengshan Mountain in the late Mesozoic.

Geomorphic expressions of active rifting reflect the role of structural inheritance: a new model for the evolution of the Shanxi Rift, northern China

Abstract. Many rifts are influenced by pre-existing structures and heterogeneities during their evolution, a process known as structural inheritance. During rift evolution, these heterogeneities may aid rift nucleation, rift growth, and the segmentation of faults; encourage the linkage of various segments; or even inhibit the formation of faults. Understanding how structural inheritance influences early rift evolution could be vital for evaluating seismic risk in tectonically active areas. The Shanxi Rift in the north of China is an active rift system believed to have formed along the trend of the Proterozoic Trans-North China Orogen; however, the influence of these pre-existing structures on the present-day rift architecture is poorly understood. Here, we use tectonic geomorphological techniques, e.g. the hypsometric integral (HI), channel steepness (ksn), and local relief, to study the evolution of the Shanxi Rift and identify areas of higher tectonic activity. We found that the HI was less sensitive to lithology and more valuable in evaluating the tectonic signal and that activity is concentrated in two rift interaction zones (RIZs) formed between the Xinding, Taiyuan, and Linfen basins. We then evaluated the relationship between the active faults and mapped pre-existing structures, finding that many faults formed parallel to inherited structures, while faults in the RIZs often cross-cut these structures. Based on these observations, we propose a new model for the evolution of the Shanxi Rift, where inherited structures play an important role in the initial segmentation of the rift, which, in turn, controls the development of the RIZ structures.

Every voice counts – Embedding the principles of Universal Design for Learning into higher education online course design

University classrooms are diverse settings. With online courses becoming increasingly more common instructors in post-secondary institutions must create inclusive learning environments that meet the needs of adult learners with exceptionalities. Goldberg et al. (2003) asserted that innovative technological tools can be used to promote student engagement, motivation, and enhance the quality of learning for students with disabilities. One such tool is the Voice Thread which can be thoughtfully and intentionally incorporated into the course design phase. Friedman and Lee (2009) contend that using visual images to present content is a necessary pedagogical strategy and provides an opportunity to reduce visual clutter. Making content visual and auditory rather than exclusively in print is a Universal Design for Learning strategy that makes the information more accessible to all students not just those who struggle with reading. Hampton and Mason (2003) reminded us that many students with learning disabilities require additional time to formulate their thoughts to make meaningful contributions to an online discussion. The features of the program offer a comfortable way for students to share their knowledge and understanding, analytical skills and personal reflections related to a particular concept. Offering a choice in the response format allows students to utilize their strengths and concentrate more fully on demonstrating their learning. Fostering an inclusive learning environment using innovative technologies, such as Voice Thread, offers online instructors a meaningful way to adopt inclusive approaches to curriculum and assessment. Pre-existing structures such as the Community of Practice (Lave &amp; Wenger, 1991) provide inclusive leaders the opportunity to share these innovations with colleagues and ensure that every voice counts.

The effect of pre-existing structures on the Cenozoic rifting processes: Insights from seismic reflection imaging of the northeastern south China sea

The South China Sea (SCS) opened due to the extension of a compressional setting of the paleo-Pacific subduction. The pre-existing structure significantly influences the geometry of rift basins and the kinematic evolution of the rifting. However, structural evidence of the paleo-Pacific subduction in the northeastern SCS remains enigmatic. The deformation front, serving as the structural evidence of paleo-subduction, is associated with accretionary style deformation and would be reactivated during the subsequent extension phase. In this study, we use a multi-channel seismic profile to investigate the pre-existing structure related to the paleo-Pacific subduction in the northeastern SCS, emphasizing the influence of pre-existing structure on the rift evolution. The seismic profile reveals imbricate reflections in the lower crust. These reflections are interpreted as the deformation front of the Paleo-Pacific subduction. Notably, the deformation front is hyperextended in the Chaoshan Depression. The result of the stretching factors indicates that the ductile lower crust experienced preferential thinning during the rifting beneath the Chaoshan Depression. In the northern part of the profile, a transparent reflection zone was identified and interpreted as a magmatic arc related to Mesozoic subduction. One major achievement of our study is these seismic reflections provide the structural evidence for Paleo-Pacific subduction and reveal that the northeastern SCS has experienced crustal shortening and imbrication through a series of dipping thrusts. Subsequently, we discuss the role of pre-existing structures in lower crustal thinning and continental rifting. We propose the deformation front of the Mesozoic subduction, as a pre-existing weakness, facilitated the kinematic evolution of the rifting in the northeastern SCS during the Cenozoic.

Evaluate the Dynamic response of Buildings to Seismic Forces, Considering the Interaction between human Occupants and Structural vibrations

Damage to buildings and other structures may occur when dynamic loads, caused by earthquake vibrations, drive the ground and everything related to it to shake in a complicated way. Civil engineers are always thinking of new methods to deal with this inevitable problem. Humans put stress on a variety of buildings, including floors, footbridges, stadiums, and more. Modern material and manufacturing technology, together with human desire for aesthetics, have made it possible to build long span structures like bridges, stadiums, floors, etc. that are sleek, lightweight, and slim. To dampen a structure's dynamic reaction, engineers use devices called (TMDs), which consist of a mass and a spring, are tuned mass dampers. When it comes to managing the structural reactions to wind and harmonic excitations, Tuned Mass Damper (TMD) is the way to go. Specifically, the shear beam and 1D lumped-mass beams are the models under consideration. The main purpose of this piece is to demonstrate how methods that use records of ambient vibration may enhance and supplement seismic risk assessments of preexisting structures. To compare the structure's reaction with and without TMD, or tuned mass damper, is mounted on the building's exterior. Using a model calculated from outside vibrations and recorded within the structure, we were able to effectively compare the building's motion to a fake ground motion. It was also determined the inter-storey drift and the stiffness of each floor.

Seismic Reflection Imaging Reveals Relict Subduction Zone of the Paleo-Pacific Plate in the Northeastern South China Sea

The South China Sea (SCS) is widely accepted as an active margin that is associated with the subduction of the Paleo-Pacific plate during the Mesozoic. However, the exact location of the subduction or suture zone remains unclear. Understanding the location of the subduction zone is crucial for comprehending the Mesozoic tectonic evolution of the South China Block and the Cenozoic rifting process of the SCS. To clarify the position of the subduction zone and the influences of preexisting structures, we used a multichannel seismic reflection profile to investigate the crustal architecture. The seismic profile reveals a crustal “crocodile” structure that is interpreted as relict subduction in the Chaoshan Depression and a set of south-dipping crust-mantle reflectors related to the initial rifting in the continent–ocean transition (COT) zone. The results indicate that a Mesozoic subduction zone is located at the northeastern margin of the SCS and that preexisting structures (subduction-related structures) facilitated the rifting process. Combined with previous studies on the oceanic plateau collision-accretionary zone of the northern SCS and the Mesozoic accretionary zone in Palawan of the southern SCS, we infer that a section of the suture zone of the Paleo-Pacific plate subduction is preserved at the northeastern SCS margin and that the rifting of the SCS may have initiated at the suture zone.

Riedel shear structures reactivation may induce earthquakes through long-term steam injection: A case study of a heavy oil production field in northwestern China

Conventional heavy oil exploitation methods involve steam stimulation and flooding. An oil field in northwestern China has been producing heavy oil via steam injection for several decades. The production area has been seismically quiet until an increase in seismicity occurred several years ago. An array of 40 seismographs has been deployed between July and October 2021 to monitor seismicity and resolve the possible causes of the recent seismicity. Using an end-to-end machine-learning-based high-precision earthquake location workflow, we analyze a microseismic sequence comprised of 178 events that occurred in the study area. Numerical simulations incorporating Coulomb failure stress suggest that prolonged steam injection can reactivate faults and induce seismic events. Similarly, fluid diffusion through conduits may achieve the same effect. Analysis of the focal mechanism solutions of 21 strike-slip and thrust events with [Formula: see text] in conjunction with the background stress regime ([Formula: see text] azimuth = N15°W) reveal that the stress distribution is compatible with a left-lateral Riedel shear structure (RSS) model. Therefore, we can speculate that steam injection may induce earthquakes by reactivating preexisting RSS fault structures. To conclude, the recent seismic events could have been induced by two possible mechanisms: (1) long-term steam injection may cause the static stress level on the faults beneath the reservoir to build up to critical levels, following which a slight stress disturbance can trigger an earthquake and (2) fluid conduits may transport condensed water to basement faults, weakening the faults through fluid diffusion.

Enhancing sand liquefaction resistance through microbial-induced partial saturation: An experimental study

The liquefaction potential of saturated sand can be significantly reduced by inducing partial saturation in the soil. Conventional soil liquefaction mitigation methods, namely soil densification, drainage, cementing, and groundwater lowering, pose environmental concerns and are challenging to apply to pre-existing structures. However, the microbially induced partial saturation (MIPS) method is emerging as a novel and eco-friendly approach to mitigate liquefaction. The MIPS method involves microbial denitrification, which produces nitrogen gas and results in a desaturating effect in the saturated soil. The current study conducted a series of stress-controlled undrained cyclic triaxial tests on saturated sandy soil and microbially-desaturated sandy soil under different relative densities and loading conditions. In addition, the study systematically analyzed the effects of temperature and pH on bacterial activity and the denitrification process. Batch experiments were conducted to establish a relationship between the initial nitrate concentration in the bacterial media and the resulting desaturation.Comprehensive analyses of cyclic resistance curves were performed to gain a thorough understanding. Additionally, the study conducts detailed analyses of the accumulation of excess pore pressure and the resulting axial strains and deformation patterns in both treated and untreated sand. This study demonstrates that the MIPS treatment considerably enhances the liquefaction resistance of treated sand.

Digitization Planning for Large Collections and Agencies with Specify 7

The Specify Collections Consortium (SCC) supports research collections around the world with an intuitive, robust, and highly-customizable software platform to digitize their holdings and manage their collections. For over 25 years, Specify has provided and sustained biological research museums and biorepositories with software for managing, integrating, and publishing collections information (Fig. 1). The SCC has increasingly engaged with very large collections managed by institutions ranging from universities to individual government departments to entire federal agencies, to envision a framework that supports standard computerization workflows and best practices. From our involvement in working with these institutions, which have successfully navigated the transition to Specify, we have gathered insights and learned lessons that may be helpful to others to better anticipate and address key data-related issues in their own institution when embarking on a Specify (or any collections management system) implementation. Understanding how to approach data preparation for import into a collections management system is crucial, as collections often face significant challenges in this area. We will discuss some of the key hurdles that collections encounter and methods to overcome them such as unstandardized data within a single collection and between multiple collections, unparsed names for taxonomy and people, and reconciling pre-existing custom data structures with the fixed structure of a collections management system. We will also cover the decision-making process for determining what collection data should be shared between collections versus what should be managed separately (scoping, data sharing, and data exporting). Large institutions often have multiple collections with diverse needs, and finding the right balance between centralized coordination and individual collection autonomy can be complex. The presentation will discuss the factors considered and the strategies employed to navigate this balance, as it can have significant implications for the overall success of a Specify deployment (Fig. 2). In addition to the technical considerations, the presentation will also delve into the human side of transitioning to a new collections management system. Successful collections management platform implementations require not only technical expertise, but also effective communication and collaboration among the collections staff, volunteers, and management. This presentation offers a framework to help other large collections successfully transition to Specify. Our team at the Specify Collections Consortium has extensive experience in supporting the transition of large research collections to their robust and highly customizable software platform. We have gained valuable insights into the key challenges and best practices for data preparation, system implementation, and change management. By sharing the lessons learned from these institutions and the SCC's experience, the presentation provides valuable insights and guidance to support other organizations in their collections management system implementation projects. A better understanding of this process will ultimately contribute to preserving and improving access to natural history collections (and soon geoscience collections) worldwide.

Interpretable machine learning models for predicting the bond strength between UHPC and normal-strength concrete

Ultra-high-performance concrete (UHPC) boasts superior mechanical properties and durability, rendering it a viable material to repair and reinforce pre-existing concrete structures. The complexity of the bond behavior between UHPC and normal-strength concrete (NC) presents a challenge to make precise predictions of the interfacial bond strength. This study employed four machine learning algorithms, namely artificial neural network, random forest, adaptive boosting, and categorical gradient boosting, to predict the interfacial bond strength of UHPC-NC. A database of 95 samples of slant shear tests was collected from existing literature. The input variables for modeling include joint angle, compressive strength of NC and UHPC, surface treatment, interfacial moisture, curing age, and curing method. The impact of each feature on the slant shear bond strength was assessed using SHapley Additive exPlanations and Partial Dependence Plots. Results show that the categorical gradient boosting model performed the best on the testing set, achieving an R2 of 0.948, RMSE of 1.408, and MAE of 1.028. The accuracy of all four machine learning models surpassed that of two empirical models (AASHTO LRFD 2014 and Eurocode 2). The top three features influencing the interfacial bond strength were identified as the surface treatment, joint angle, and compressive strength of NC, while the impact of the curing method and the interfacial moisture were comparatively limited. The proposed machine learning model exhibits potential as a valuable tool for assisting structural retrofitting and rehabilitation with UHPC.

The Missing Agrarian Middle Class

During the middle decades of the twentieth century, Puerto Rico embarked on one of the most rapid processes of industrialization and economic development the world had ever seen. Yet the industrial economy that this process produced had two fundamental flaws: it featured little by way of local capital formation in the manufacturing sector, and it was incapable of producing sufficient employment for the island’s labor force. What explains these flaws? This article seeks to answer this question by drawing on the rich literature on development in East Asia. I engage with four theories that explain successful East Asian development on the basis, respectively, of unique insertion into the international political economy, robust industrial policies, economic nationalism, and agrarian reform processes that preceded industrialization. While Puerto Rico benefited from all of these factors—which may explain the relative success of development on the island—they differed qualitatively from the East Asian cases, with the possible exception of international political economy. I suggest that these differences might in turn be explained by substantial differences in pre-existing agrarian class structure. The absence of a significant stratum of smallholding agricultural producers in Puerto Rico distinguished the island from East Asian societies. It also helps explain the lack of local capital formation and employment generation built into the Puerto Rican development model, as well as the shape of industrial policy and agrarian reform and the ultimate weakness of nationalist impulses.

Evolutionary patterns and functional effects of 3D chromatin structures in butterflies with extensive genome rearrangements

Chromosome rearrangements may distort 3D chromatin architectures and thus change gene regulation, yet how 3D chromatin structures evolve in insects is largely unknown. Here, we obtain chromosome-level genomes for four butterfly species, Graphium cloanthus, Graphium sarpedon, Graphium eurypylus with 2n = 30, 40, and 60, respectively, and Papilio bianor with 2n = 60. Together with large-scale Hi-C data, we find that inter-chromosome rearrangements very rarely disrupted the pre-existing 3D chromatin structure of ancestral chromosomes. However, some intra-chromosome rearrangements changed 3D chromatin structures compared to the ancestral configuration. We find that new TADs and subTADs have emerged across the rearrangement sites where their adjacent compartments exhibit uniform types. Two intra-chromosome rearrangements altered Rel and lft regulation, potentially contributing to wing patterning differentiation and host plant choice. Notably, butterflies exhibited chromatin loops between Hox gene cluster ANT-C and BX-C, unlike Drosophila. Our CRISPR-Cas9 experiments in butterflies confirm that knocking out the CTCF binding site of the loops in BX-C affected the phenotypes regulated by Antp in ANT-C, resulting in legless larva. Our results reveal evolutionary patterns of insect 3D chromatin structures and provide evidence that 3D chromatin structure changes can play important roles in the evolution of traits.

Semantic structures facilitate threat memory integration throughout the medial temporal lobe and medial prefrontal cortex

Emotional experiences can profoundly impact our conceptual model of the world, modifying how we represent and remember a host of information even indirectly associated with that experienced in the past. Yet, how a new emotional experience infiltrates and spreads across pre-existing semantic knowledge structures (e.g., categories) is unknown. We used a modified aversive sensory preconditioning paradigm in fMRI (n= 35) to investigate whether threat memories integrate with a pre-established category to alter the representation of the entire category. We observed selective but transient changes in the representation of conceptually related items in the amygdala, medial prefrontal cortex, and occipitotemporal cortex following threat conditioning to a simple cue (geometric shape) pre-associated with a different, but related, set of category exemplars. These representational changes persisted beyond 24h in the hippocampus and perirhinal cortex. Reactivation of the semantic category during threat conditioning, combined with activation of the hippocampus or medial prefrontal cortex, was predictive of subsequent amygdala reactivity toward novel category members at test. This provides evidence for online integration of emotional experiences into semantic categories, which then promotes threat generalization. Behaviorally, threat conditioning by proxy selectively and retroactively enhanced recognition memory and increased the perceived typicality of the semantic category indirectly associated with threat. These findings detail a complex route through which new emotional learning generalizes by modifying semantic structures built up over time and stored in memory as conceptual knowledge.