Early Evolution Research Articles

The SAGES MASTERS program bariatric surgery pathway selects 10 seminal publications on revisional bariatrics.

The Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) Masters Program designated bariatric surgery as a clinical pathway. Among the tiers of the Masters Program, revisional bariatric surgery is the highest tier of "mastery" within the pathway. This article presents the top 10 seminal studies representing the current landscape of revisional bariatrics. The literature was systematically searched and seminal articles designated by consensus agreement of the SAGES Metabolic and Bariatric Surgery committee using multiple criteria, including impact on the field, citation frequency, and expert opinion. Articles were reviewed by committee members and presented in summarized fashion. The top 10 papers are presented in grouped thematic categories covering the early evolution of revisional bariatrics, changing criteria for reoperative bariatric surgery, divergence of revision versus conversion bariatric surgery, and recent technologic innovations in revisional bariatric surgery. Each summary is presented with expert appraisal and commentary. These seminal papers represent a snapshot of the dynamic field of revisional bariatric surgery and emphasize the need to not only remain current with contemporary trends but also keep a patient-oriented perspective on patient and intervention selection for optimal success.

From earthquakes to island area: multi‐scale effects upon local diversity

Tropical forests occupy small coral atolls to the vast Amazon basin. They occur across bioregions with different geological and climatic history. Differences in area and bioregional history shape species immigration, extinction and diversification. How this effects local diversity is unclear. The Indonesian archipelago hosts thousands of tree species whose coexistence should depend upon these factors. Using a novel dataset of 215 Indonesian forest plots, across fifteen islands ranging in area from 120 to 785 000 km2, we apply Gaussian mixed effects models to examine the simultaneous effects of environment, earthquake proximity, island area and bioregion upon tree diversity for trees ≥ 10 cm diameter at breast height. We find that tree diversity declines with precipitation seasonality and increases with island area. Accounting for the effects of environment and island area we show that the westernmost bioregion Sunda has greater local diversity than Wallacea, which in turn has greater local diversity than easternmost Sahul. However, when the model includes geological activity (here proximity to major earthquakes), bioregion differences are reduced. Overall, results indicate that multi‐scale, current and historic effects dictate tree diversity. These multi‐scale drivers should not be ignored when studying biodiversity gradients and their impacts upon ecosystem function.

The Apollo 17 Regolith: Induced Thermoluminescence Evidence for Formation by a Single Event ∼100 Million Years Ago and Possibly the Presence of Tycho Material

AbstractWe explored the geological history of the Taurus‐Littrow Valley at the Apollo 17 landing site through the induced thermoluminescence (TL) properties of regolith samples collected from the foothills of the Northern and Southern Massifs, from near the landing site, and from the deep drill core taken in proximity to the landing site. The samples were recently made available by NASA through the Apollo Next Generation Sample Analysis program in anticipation of the forthcoming Artemis missions. We found that the two samples from the foothills of the massifs exhibit induced TL values approximately four times higher than those of the valley samples. This observation is consistent with their elevated plagioclase content, indicating their predominantly highland material composition. Conversely, the valley samples display induced TL values characteristic of lunar mare material. The samples from the deep drill core demonstrate uniformly induced TL properties, despite originating from depths of up to 3 m. Notably, one of the samples from the lower section of the deep drill core presents anomalous‐induced TL readings. This anomaly coincides with elevated levels of low‐potassium KREEP along with reduced quantities of anorthositic gabbro and orange glass, and could be due to the traces of phosphate minerals. Alternatively, this observation raises the possibility that this sample contains Tycho impact material. The induced TL data is consistent with the regolith, extending to a depth of at least 3 m, having been deposited by a singular event approximately 100 million years ago. This timing aligns with the hypothesized formation of the Tycho crater.

A new stegosaurian dinosaur (Ornithischia: Thyreophora) with a remarkable dermal armour from the Middle Jurassic of North Africa

In recent years the Middle Atlas of Morocco has become an area of interest for the study of dinosaurs in northern Africa. The Boulahfa locality, near Boulemane, has produced a diverse dinosaur assemblage from the Middle Jurassic of the El Mers Group. Fossil remains of sauropods and thyreophorans, such as ankylosaurs (Spicomellus) and stegosaurs (Adratiklit), have been reported so far in this region. Here, we describe a new partial thyreophoran skeleton found in the gray marls of the El Mers III Formation (Bathonian-? Callovian), which mainly consists of disarticulated dorsal vertebrae and ribs, and associated dermal armour elements. Axial characters (e.g., elongated pedicels of the dorsal neural arches; upturned transverse processes and dorsal ribs with straight axes suggesting a narrow ribcage) indicate that the specimen belongs to a medium to large-sized stegosaur. The dorsal vertebrae show differences with those of Adratiklit, whose material has been found at the same stratigraphic levels. Thyreosaurus atlasicus gen. et sp. nov. is characterized by a remarkable dermal armour, which consists of thick (up to 4 cm) subovate to subrectangular-shaped osteoderms. The asymmetrical texture of their sides, one roughly ornamented with small pits and fiber bundles, the other with a well-marked cross-hatched pattern, is clearly different from that observed to date in other stegosaurs (and ankylosaurs). The bone histology of these osteoderms is reminiscent of that of stegosaurian tail spines. It is interpreted that these osteoderms were arranged in a recumbent position over the body of the animal, instead of an erect position. The holotype corresponds to an adult individual who did not reach its maximum body size (estimated body length 6 m). The phylogenetic analysis suggests that Thyreosaurus is closely related to Dacentrurus within Dacentrurinae. The recent discoveries of Adratiklit and Thyreosaurus provide insight into the early evolution of stegosaurs in the Middle Jurassic of Africa.

On the Rhodopean protoliths and their Middle Jurassic to Early Cretaceous evolution. A review

The Rhodope Massif represents a large high-grade metamorphic complex situated in the Balkan Peninsula, straddling the border between Bulgaria and Greece. Geological studies carried out during the last thirty years clearly established that the complex is composed of three major lithotectonic units characterized by differing protolith ages and Alpine thermotectonic evolution. The Rhodope Massif consists of Upper and Lower terranes representing continental fragments composed mainly of pre-Mesozoic magmatic rocks and covered by Early Mesozoic sedimentary sequences. These two entities are separated by an Intermediate Terrane comprising a Jurassic magmatic arc and its host rocks tectonically intercalated with Jurassic ophiolitic fragments together with the Early Mesozoic sediments. Detailed analyses of the previously published geochronological data revealed that the three main tectonic terranes were juxtaposed in the Late Jurassic–Early Cretaceous during the continental collision and northward subduction of the Lower and Intermediate terranes. These rocks experienced Middle Jurassic to Early Cretaceous high-pressure metamorphism, followed by high-temperature one accompanied by anatexis. At that time, the Upper Terrane was metamorphosed and deformed only partially. Being part of the European margin, this terrane represented an upper continental plate during the subduction, and therefore is not considered as a part of the Alpine Rhodope metamorphic complex. It is important to note that, although most of the present-day fabric and major tectonic zones in the Rhodope metamorphic complex are younger than Early Cretaceous, and therefore they postdate the geological evolution discussed in this study, they often reactivate the old boundaries between the main terranes and units.

Metallogenetic epoch and material source of Be-pegmatite differentiated from biotite granite in Mufushan complex

The Mufushan Complex (MFSC) is a significant rare metal mineralized in the central China district and is renowned for its marked economic value of rare metal deposits. While the main rare metal mineralization (RMM) stage in the MFSC relates to the magmatic event of two-mica monzogranite, the mineralization event related to biotite monzogranite remains unknown. To fill this gap, this study focuses on porphyritic biotite monzogranite and adjacent Be-rich pegmatite samples obtained from Changqing Pegmatite No. 1, which is situated in the southeastern part of the MFSC. We subjected these samples to zircon U–Pb dating and Hf isotope analysis using laser ablation inductively coupled plasma mass spectrometry (LA–ICP–MS) and utilized an electron probe X-ray microanalyzer (EPMA) and LA–ICP–MS to examine the major and trace elements present in the muscovite samples. Our findings revealed precise chronological data for the geological history of Changqing, pinpointing the intrusion age of biotite monzogranite to 145.8 ± 1.1 Ma and the crystallization age of Be-rich pegmatite to 144.9 ± 1.1 Ma, firmly situating these events within the Late Jurassic to Early Cretaceous epoch. Regarding isotopic composition, zircon εHf (t) for granite ranged from −9.29 to −5.09, and their corresponding TDM2 ranged from 1788 to 1520 Ma. Similarly, zircon εHf (t) for pegmatite ranged from −7.89 to −5.47, and their corresponding TDM2 ranged from 1699 to 1544 Ma. These isotopic signatures strongly indicate a shared origin for the initial magma of granite and pegmatite. The partial melting of the thick Lengjiaxi Group tasedimentary strata serves as a material source for RMM. The transition from granite to pegmatite exhibits remarkable constancy in the primary components of muscovite. By examining its geochemical attributes, we observed synchronous decreases in FeO, MgO, SiO2, MnO, Be, Rb, and Cs, coupled with synchronous increases in Nb and Ta contents, along with Ta/Nb values. These findings strongly imply that the Changqing biotite monzogranite and Be-rich pegmatite originate from the continuous differentiation and evolution of a common magmatic source, establishing a clear genetic relationship between them. The MFSC has its origins in three distinct stages of magmatic activity and RMM spanning from 160 Ma to 120 Ma. Considering the distribution patterns of similar pegmatite veins, the metallogenic potential observed during the biotite granite stage may serve as an external indicator of marked mineralization within large batholiths.

An Image Retrieval Method for Lunar Complex Craters Integrating Visual and Depth Features

In the geological research of the Moon and other celestial bodies, the identification and analysis of impact craters are crucial for understanding the geological history of these bodies. With the rapid increase in the volume of high-resolution imagery data returned from exploration missions, traditional image retrieval methods face dual challenges of efficiency and accuracy when processing lunar complex crater image data. Deep learning techniques offer a potential solution. This paper proposes an image retrieval model for lunar complex craters that integrates visual and depth features (LC2R-Net) to overcome these difficulties. For depth feature extraction, we employ the Swin Transformer as the core architecture for feature extraction and enhance the recognition capability for key crater features by integrating the Convolutional Block Attention Module with Effective Channel Attention (CBAMwithECA). Furthermore, a triplet loss function is introduced to generate highly discriminative image embeddings, further optimizing the embedding space for similarity retrieval. In terms of visual feature extraction, we utilize Local Binary Patterns (LBP) and Hu moments to extract the texture and shape features of crater images. By performing a weighted fusion of these features and utilizing Principal Component Analysis (PCA) for dimensionality reduction, we effectively combine visual and depth features and optimize retrieval efficiency. Finally, cosine similarity is used to calculate the similarity between query images and images in the database, returning the most similar images as retrieval results. Validation experiments conducted on the lunar complex impact crater dataset constructed in this article demonstrate that LC2R-Net achieves a retrieval precision of 83.75%, showcasing superior efficiency. These experimental results confirm the advantages of LC2R-Net in handling the task of lunar complex impact crater image retrieval.

Constraints and dynamic assessment of biomethane generation from cyclically nutrients stimulation

The generation of biomethane in geological history is primarily influenced by multi-stage tectonic uplift and diverse groundwater charging conditions. To investigate and simulate this process, we conducted laboratory experiments involving cyclic addition of nutrients. The results demonstrate that continuous nutrient supplementation is a viable approach for achieving sustained biomethane production, with yields ranging from 1191.53 to 1316.90 μmol/g over three biodegradation cycles. Fitzhugh models prove to be the most suitable for predicting biomethane production. Biodegradation induces rearrangement of coal's pore structure, leading to increased pore sizes and numbers, facilitating the infiltration of biological enzymes, and enhancing methanogenesis rates. Our study elucidates the mechanisms underlying biomethane generation in geological history and offers strategies to expedite the practical application of coalbed methane bioengineering.

The three-dimensionally articulated oral apparatus of a Devonian heterostracan sheds light on feeding in Palaeozoic jawless fishes.

Attempts to explain the origin and diversification of vertebrates have commonly invoked the evolution of feeding ecology, contrasting the passive suspension feeding of invertebrate chordates and larval lampreys with active predation in living jawed vertebrates. Of the extinct jawless vertebrates that phylogenetically intercalate these living groups, the feeding apparatus is well-preserved only in the early diverging stem-gnathostome heterostracans. However, its anatomy remains poorly understood. Here, we use X-ray microtomography to characterize the feeding apparatus of the pteraspid heterostracan Rhinopteraspis dunensis (Roemer, 1855). The apparatus is composed of 13 plates arranged approximately bilaterally, most of which articulate from the postoral plate. Our reconstruction shows that the oral plates were capable of rotating around the transverse axis, but likely with limited movement. It also suggests the nasohypophyseal organs opened internally, into the pharynx. The functional morphology of the apparatus in Rhinopteraspis precludes all proposed interpretations of feeding except for suspension/deposit feeding and we interpret the apparatus as having served primarily to moderate the oral gape. This is consistent with evidence that at least some early jawless gnathostomes were suspension feeders and runs contrary to macroecological scenarios that envisage early vertebrate evolution as characterized by a directional trend towards increasingly active food acquisition.

Petrogenesis of newly identified mantle-plume-related ca. 3.3 Ga tholeiitic-komatiitic rocks in the Anshan area, North China Craton

The geodynamic regime that governed the crustal evolution of Earth during the early Archean remains intensely debated. The North China Craton (NCC) preserves a geological history spanning 3.8–2.5 Ga, particularly in the Anshan area, making it an ideal natural laboratory for probing the formation and evolution of the NCC and its associated geodynamic regime. Here, we document new geochronology, geochemistry, and zircon Hf-O isotope data from newly discovered Paleoarchean meta-mafic rocks in the Anshan area. Based on their whole-rock geochemistry, these unit can be divided into tholeiitic and komatiitic series. Of which, the komatiitic rocks are characteristic by high MgO contents (up to 20.6 wt%). Zircon U-Pb dating shows that all meta-mafic rocks formed contemporaneously, with crystallization ages of ca. 3.3 Ga. Most of the studied meta-mafic rocks display radiogenic zircon Hf isotopes, with TDM1 ages ranging from 3592 to 3346 Ma and εHf(t) values from −1.94 to + 3.49. They also exhibit mantle-like zircon δ18O values (+4.92 ‰ to + 5.98 ‰). These zircon Hf-O isotope data indicate that the protoliths of the ca. 3.3 Ga meta-mafic rocks originated from the partial melting of a depleted mantle without significant crustal contamination. Furthermore, the parental magmas of the komatiitic rocks and some of tholeiitic rocks were generated from 20 % and 5–10 % partial melting of spinel-lherzolite, respectively, whereas other tholeiitic rocks were the result of a low degree (1–5 %) of partial melting of spinel-garnet lherzolite. The ca. 3.3 Ga tholeiitic-komatiitic rocks were most likely formed in an intraplate rifting setting, associated with a mantle plume.

Subsurface architecture of the Wajrakarur Kimberlite Field, Dharwar Craton, India: Evidence from ground magnetic surveys

The Ground magnetic study in the Wajrakarur Kimberlite Field and adjoining area has unveiled prominent geological variations, including felsic doming beneath the PGC-II formation to the west of the Cuddapah Basin and mafic doming beneath the Closepet Granite zone. These doming features within the upper mantle are identified as sources of mantle upwelling, which influence the emplacement of corresponding intrusive rocks. The presence of mafic chambers enhances the magnetic response, leading to localized high signatures in magnetic data and contributes to a better understanding of the subsurface composition and distribution of rock types. The present magnetic data throw lights to study the complexity of the sub-surface structure and geological activities, have shaped the study area and serve as valuable markers for understanding the geological evolution of the area. The intersections of magnetic lineament oriented in NW-SE, NE-SW, E-W yield crucial insights into geological structures and the emplacement of Kimberlite intrusions. Through comprehensive magnetic data analysis, the study offers a unique cross-sectional view of the subsurface, reaching depth up to 60 km. This perspective unveils magnetic sources and structures, revealing shallow features, interfaces of the Archaean basement, crustal roots, and upper mantle configuration. Profound magnetic gradients observed in the study area serve as indicators of fault lines influenced by tectonic activity, kimberlite intrusion, and other fault-related mineralization if any. These features contribute to a deeper understanding of the structural configurations and geological history of the area. The present study provides information about the lateral and vertical layouts of major structures as well as the deep-seated channels. It also introduces the mafic and felsic categories of rocks, explaining the complex relationships between underlying structures, geological characteristics, and magnetic anomalies.

The complex circumstellar environment of supernova 2023ixf.

The early evolution of a supernova (SN) can reveal information about the environment and the progenitor star. When a star explodes in vacuum, the first photons to escape from its surface appear as a brief, hours-long shock-breakout flare1,2, followed by a cooling phase of emission. However, for stars exploding within a distribution of dense, optically thick circumstellar material (CSM), the first photons escape from the material beyond the stellar edge and the duration of the initial flare can extend to several days, during which the escaping emission indicates photospheric heating3. Early serendipitous observations2,4 that lacked ultraviolet (UV) data were unable to determine whether the early emission is heating or cooling and hence the nature of the early explosion event. Here we report UV spectra of the nearby SN 2023ixf in the galaxy Messier 101 (M101). Using the UV data as well as a comprehensive set of further multiwavelength observations, we temporally resolve the emergence of the explosion shock from a thick medium heated by the SN emission. We derive a reliable bolometric light curve that indicates that the shock breaks out from a dense layer with a radius substantially larger than typical supergiants.

The role of intra-oceanic arc in the growth of continental crust: Evidence from the Early Paleozoic Bainaimiao arc

The Early Palaeozoic arc-related formations in the northern margin of the North China Craton (NCC) belonging to the Bainaimiao arc belt is an important part of the eastern Central Asian Orogenic Belt (CAOB). The tectonic evolution of this belt remains controversial. Here we present detailed data on the geochronology and geochemistry on a newly identified Early Palaeozoic igneous suite from the Faku area in northern Liaoning. Zircon U–Pb dating of the Faku volcanic and intrusive rocks yielded weighted mean 206Pb/238U ages of ca. 458 Ma and 433–405 Ma, respectively, which represent their crystallization (eruption) times. Zircon Hf isotopic analyses show a low negative to positive εHf (t) values of − 0.33 to + 12.4, implying depleted characteristics of the source. The geochemical features of Laolingshan basaltic andesites display higher TiO2 and lower P2O5 contents, similar to that of mid-ocean ridge basalts, and relatively high Zr/Y and low Ta/Yb ratios, suggesting oceanic island arc basalt affinity. Therefore, we suggest that the Laolingshan basaltic andesites were formed in an intra-oceanic environment. The Bachagou granodiorites, with adakitic geochemical signatures, belong to the calc-alkaline and high-K calc-alkaline series, implying formation in an active continental margin tectonic setting. The Baerhushan granodiorites, which geochemically belong to S-type granites, were probably formed in a syn-collisional environment influenced by arc–continent collision. The Donggou granitoids, which have higher SiO2 and alkali and lower MgO and P2O5, show A-type granite features. Geochemical characteristics of the Donggou A-type granite suggest formation in an extensional setting caused by orogenic intermittent extension. The Baerhushan gabbro diorites, which display properties of both mid-ocean ridge and continental rift basalts, were produced under post-orogenic extensional tectonic setting after the arc–continent collision. Our study traces the Early Palaeozoic tectonic evolution of the south-eastern segment of the CAOB and the related accretionary tectonics.

Glaciological studies in Mexico, 60 years of academic work: A summary

Glaciers have played a very important role in controlling the climate during most of the geologic history of our planet Earth. Of course, the glaciers have always been at higher latitudes (north and south), and some on high-altitude mountains. Current glaciers in Mexico are those inherited from the Last Glacial Maximum, (26000 - 19000 years before the present), increasing in size during the period of the Little Ice Age (1300 to 1850 common era), and they are unique in several ways; they are located at 19° north latitude, and they received snow precipitation from both the Pacific Ocean and the Gulf of Mexico (Atlantic Ocean). Research on glacial chronology, physical glaciology, and glacial geochemistry at Universidad Nacional Autónoma de México has provided valuable information on climate and environmental changes at different time scales, from millennial to decadal, and even annual. The first part of this work deals with the reconstruction of the glacial history in Mexico and establishing a glacial chronology from the Last Glacial Maximum to the Little Ice Age. The second part of this work focuses on monitoring recent changes (the last 60 years, 1960s to 2023) of the glacier extent on Iztaccíhuatl, Popocatépetl, and Citlaltépetl (the three highest mountains in Mexico), as well as having an updated inventory of all the glaciers at those mountains. Changes in glacier extent and thickness of ice are directly related to the increase in air temperature, variation in precipitation patterns, and glacier dynamics on some of the last glaciers of the northern tropics. The third part or this work focuses on a compilation of geochemical data from 17 years (from 2006 to 2013) of sampling ice (shallow ice cores) and snow at Iztaccíhuatl and Citlaltépetl glaciers. This database has the potential for providing interesting and useful information on natural and anthropogenic-induced changes related to the occurrence of heavy metals in tropical glaciers in the northern hemisphere of North America. Black carbon concentrations analyzed in snow and glacier ice, and preliminary data on stable isotopes of Zn, also add information on natural vs. anthropogenic sources of heavy metals in central Mexico.

The Great Valley of Virginia as place and time in American geoheritage

Abstract The Great Valley of Virginia (GVV) is a section of a much larger geological structure that spans from the northeastern USA through the mid-Atlantic and to the SE. While the structural formation of the region represents nearly 1.2 billion years of geological history, the rocks that remain record vast cycles of tectonic change. The legacy of that geology is a rich and aesthetically attractive region that has drawn many peoples over time to its agricultural fertility and geological resources. This contribution traces the geological development of the GVV, the relationship of the GVV to the peoples, both indigenous and European colonizers, who have inhabited the GVV over thousands of years and the geological resources that the inhabitants found. Although relatively under-expressed from a geoheritage perspective, the GVV possesses a rich legacy of how its resources supported each society's needs and interests and the role its geological environment has played at critical moments in the historical development of the USA over the last 400 years.

Mechanisms of Waterflood Inefficiency: Analysis of Geological, Petrophysical and Reservoir History, a Field Case Study of FWU (East Section)

The petroleum reservoir represents a complex heterogeneous system that requires thorough characterization prior to the implementation of any incremental recovery technique. One of the most commonly utilized and successful secondary recovery techniques is waterflooding. However, a lack of sufficient investigation into the inherent behavior and characteristics of the reservoir formation in situ can result in failure or suboptimal performance of waterflood operations. Therefore, a comprehensive understanding of the geological history, static and dynamic reservoir characteristics, and petrophysical data is essential for analyzing the mechanisms and causes of waterflood inefficiency and failure. In this study, waterflood inefficiency was observed in the Morrow B reservoir located in the Farnsworth Unit, situated in the northwestern shelf of the Anadarko Basin, Texas. To assess the potential mechanisms behind the inefficiency of waterflooding in the east half, geological, petrophysical, and reservoir engineering data, along with historical information, were integrated, reviewed, and analyzed. The integration and analysis of these datasets revealed that several factors contributed to the waterflood inefficiency. Firstly, the presence of abundant dispersed authigenic clays within the reservoir, worsened by low reservoir quality and high heterogeneity, led to unfavorable conditions for waterflood operations. The use of freshwater for flooding exacerbated the adverse effects of sensitive and migratory clays, further hampering the effectiveness of the waterflood. In addition to these factors, several reservoir engineering issues played a significant role in the inefficiency of waterflooding. These issues included inadequate perforation strategies due to the absence of detailed hydraulic flow units (HFUs) and rock typing, random placement of injectors, and uncontrolled injected fresh water. These external controlling parameters further contributed to the overall inefficiencies observed during waterflood operations in the east half of the reservoir. A detailed understanding of the mechanistic factors of inefficient waterflood operation will provide adequate insights into the development of the improved recovery technique for the field.

Automatic Extraction of Martian Subsurface Layer from Radargrams Based on PDE Denoising and KL Filter

The polar regions of Mars, including the South and North Poles, are crucial for studying Martian climate and geological history, as they contain the largest reservoir of subsurface water ice. This study introduces a new approach for reflector detection, which includes radargram denoising to effectively enhance the signal of underground reflectors, peak detection to extract the positions of subsurface stratification from the radar echoes, and peak points connection to form continuous layers. The mapped enhancement denoising process involves a linear brightness adjustment and a fourth-order diffusion equation to enhance the signal of the subsurface layers for effective detection. The subsurface detection extracts the surface and subsurface peak points based on a peak detection algorithm, while using locally window-enhanced peak filtering and Kullback–Leibler (KL) divergence mapping to filter out non-stratified peak points. Finally, the layered connection process uses the proximity parameter to connect peak points in the same layer. Applied to multiple SHARAD (Shallow Radar) images at the Martian poles, this algorithm demonstrated a false detection rate below 5%. Compared to other methods, this method has a missed detection rate of less than 5% and, additionally, exhibits fewer discontinuities in layer connectivity. Therefore, this algorithm shows exceptional proficiency and applicability in analyzing the complex subsurface structures of the Martian polar regions.

Abstract 6098: Spatial single-cell immune microenvironment analysis reveals the transition from innate to adaptive immune response during early lung adenocarcinoma carcinogenesis

Abstract Introduction: Lung cancer remains the leading cause of cancer death worldwide. Although prevention holds the promise to reduce lung cancer mortality, the results from randomized trials have been disappointing, likely due to our rudimentary knowledge of early lung cancer carcinogenesis. Cancer initiation and progression involve complex processes dependent on the dynamic interplay of individual cells within the tumor microenvironment (TME). Our understanding of the multicellular composition, interaction, spatial distribution, and functional dynamics during the early evolution from precancer to invasive LUAD is limited. Methods: We performed spatial single cell immune microenvironment analysis of 10 normal, 40 AAH, 22 AIS, 18 MIA, and 34 IAC by Imaging Mass Cytometry (IMC) and analyzed high-dimensional images of 1,618 regions-of-interest (ROIs) using a 34-plex marker. Using machine learning approaches, we classified 4,828,879 cells into 14 major cell types, which were subjected to further analysis for multicellular composition, interaction, spatial distribution, and functional dynamics in LUAD precursors of different stages. Results: From AAH to AIS, MIA, and IAC, we observed a gradual escalation in the density (number of cells/mm2) of all immune subsets. Proportionally, adaptive immune cells exhibited a progressive increase, whereas innate immune cells demonstrated a concurrent decrease with the neoplastic progression from normal lung to AAH, AIS, MIA, and ADC. Notably, macrophages emerged as the predominant immune cells within the immune microenvironment of these LUAD precursors. Upon closer examination of subtypes, protumor M2 macrophages showed a gradual increase from AAH to AIS, MIA, and IAC, whereas anti-tumor M1 macrophages increased from normal to AIH, AIS and subsequently decreased in AIS, MIA, and IAC stages. These alterations resulted in a progressive increase in M2/M1 ratios from AAH to IAC stages. Furthermore, M2 macrophages exhibited higher heterotypic interactions with epithelial cells than M1 across LUAD precursors of different stages, especially in the later stages. Co-expression analysis revealed 5 modules that distinguishes each histological stage. Tim-3 module was significantly enriched in AAH lesions, while NK cell-related features were enriched at AIS stage, B cell-related features enriched at MIA stage and Ki-67-related adaptive immune features enriched in IAC stage. Conclusion: The spatial single cell immune microenvironment analysis revealed a transition from innate to adaptive immunity during initiation and early progression of LUAD progression and innate immunity may play critical roles during early LUAD development. Therefore, reprograming innate immunity such as repolarization of M2/M1 may provide avenues to intercept LUAD precursors to prevent invasive LUAD. Citation Format: Bo Zhu, Pingjun Chen, Muhammad Aminu, Junya Fujimoto, Lingzhi Hong, Andre L. Moreira, Jian-Rong Li, Yanhua Tian, Luisa M. Solis Soto, Parra Cuentas Edwin Roger, Ou Shi, Hong Chen, Frank R. Rojas, Eduardo Vilar, Anirban Maitra, Ken Chen, Nicolas Navin, Cara L. Haymacker, Vamsidhar Velcheti, Daniel H. Sterman, P Andrew Futreal, Don L. Gibbons, Ignacio I. Wistuba, John V. Heymach, Chao Cheng, Harvey I. Pass, Jia Wu, Jianjun Zhang. Spatial single-cell immune microenvironment analysis reveals the transition from innate to adaptive immune response during early lung adenocarcinoma carcinogenesis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6098.

Exceptional preservation of a marine tapeworm tentacle in Cretaceous amber

Parasites are ubiquitous in extant ecosystems but rarely preserved in the geological record, especially parasitic worms (helminths). One such group is Cestoda (tapeworms), a specialized endoparasitic group of platyhelminths (flatworms). They have a complex lifecycle with at least two hosts, infecting all major groups of vertebrates. However, their fossil record is extremely sparse due to their soft tissue and concealed habitats, with the only widely accepted example before the Quaternary being eggs discovered in a shark coprolite from the Permian. The lack of body fossils greatly hampers our understanding of their early evolution. We report a slender, armed fossil from mid-Cretaceous Kachin (Myanmar) amber (ca. 99 Ma). This fossil displays unique external (armature pattern) and internal (partially invaginated tentacle and rootless hooks) features that are most consistent with the tentacles of extant trypanorhynch tapeworms that parasitize marine elasmobranchs (mainly sharks and rays). Our study thus probably provides not only the first partial body fossil of a tapeworm, but also arguably the most convincing body fossil of a flatworm. In addition, the exquisite invaginated tentacle inside the fossil highlights that amber can preserve the internal structure of helminths. Remarkably, nearly all extant trypanorhynchs are endoparasites of marine elasmobranchs, thus our study provides an exceptional example of a marine endoparasite trapped in terrestrial amber.

Abstract 4254: Genetically engineered human lung organoid models for lung cancer evolution study

Abstract Initial cellular events in a transitional period from normal to cancer cells, such as transcriptomic or epigenetic dynamics, are poorly understood. Observing these is more challenging than in cancer progression, especially for humans. Mapping this phenomenon in early cancer evolution is crucial, as we can identify targetable molecules to inhibit cancer development at the precancerous stage. Immortalized human cancer cell lines hardly capture these appropriately as they have lost usual cellular characteristics. Normal organoids harbor stem cells and their differentiated cells, reflecting the epithelial physiology of tissues, and are more suitable models for cancer evolution studies. To establish a human cancer development model in vitro, we genetically engineered normal human airway organoids derived from adult stem cells into small cell lung cancer (SCLC). We used CRISPR-Cas9 systems to induce non-homologous end-joining in both TP53 and RB1, the most frequently mutated genes of SCLC. First, we knocked out TP53 of the airway organoids, selected by Nutlin-3a, an MDM2 antagonist, for 3-4 weeks, demonstrating 88-89% editing efficiencies calculated from Sanger sequencing results. Most mutations were one base pair deletion or insertion, which induced frameshift mutation in TP53. They did not show a significant difference from wild-type organoids morphologically at bright-field microscopy. Subsequently, we targeted RB1 on TP53-/- airway organoids to induce SCLC. We used Palbociclib, a CDK4/6 inhibitor, to enrich the mutated cells. They had 67.1% efficiency, and 20.4% had a 7-base pair deletion mutation. In the initial period, they seemed to have similar shapes to TP53-/- organoids. Unexpectedly and interestingly, however, we noticed more rapidly proliferating and disorganized organoids disrupting their original round shapes appeared in 4-5 weeks. The cells were indiscriminately piled up on the airway organoids' apical and basolateral surfaces, indicating their malignant traits. Their chaotic proliferation represented the rapidly progressing clinical feature of SCLC with a median survival of 7-16 months with treatment. This is the first work constructing the SCLC development model from the normal human airway organoid. By sequentially single-cell sequencing this organoid model changing to tumorous condition, we can capture the multi-omics landscape during the initial evolution of SCLC. Citation Format: Sungji Moon, Rokhyun Kim, Dakyung Lee, Kyunghyuk Park, Woochan Lee, Seyoon Lee, Young Jun Park, Jongil Kim. Genetically engineered human lung organoid models for lung cancer evolution study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4254.