Explore the vast range of titles available.

This work was supported by the Generalitat Valenciana Grant PROMETEO CIPROM/2022/21 (M.d.l.P.) and the Spanish Ministry of Science and Innovation and Agencia Estatal de Investigación (PID2021-125175OB-I00) (M. M.-G.). JLS was supported by Programa Propio para el fomento de la I+D+i en la Universidad de Alicante 2022 UAFPU22-11 grant and the Spanish Ministry of Science and Universities FPU FPU23/00226 grant.

Recent extensive metatranscriptome mining vastly expanded the range of apparently covalently closed circular (ccc) RNA replicons. A notable family of such replicons is Obelisks, ~1 kilobase (kb) cccRNAs encoding a protein with a unique fold, Oblin-1, and detected in diverse metatranscriptomes. To identify potential cccRNAs in a sequence similarity–independent manner, we adopt the Fragmented and primer-Ligated DsRNA Sequencing (FLDS) method to selectively sequence double-stranded (ds) RNAs, replicative intermediates of RNA replicons. We focus on candidates with predicted extensive intramolecular base-pairing, a hallmark of viroid-like elements. Using FLDS, we explore metatranscriptomes from acidic hot springs in Japan and discover a distinct family of Obelisks apparently associated with thermoacidophilic bacteria (Hot spring Obelisks, HsObs). Despite lacking sequence similarity to known Oblins, HsObs share key features, including ~1 kb genome size, rod-like RNA secondary structure, and the predicted fold of the encoded protein, HsOblin. A comprehensive metatranscriptome search for Oblin-1 and HsOblin homologs expands Obelisk diversity about two-fold, revealing multiple subfamilies sharing the same core fold,. some of which are also predicted to encode additional small proteins with simple alpha-helical folds. These findings highlight Obelisks as widespread and overlooked components of microbial ecosystems, expanding understanding of viroid-like RNA replicon diversity and evolution. In this study, the authors identify circular RNAs replicating in high-temperature hot spring environments and demonstrate that ccc RNA replicons belonging to the Obelisk superfamily are more diverse and widespread than previously recognized, revealing hidden RNA systems in natural environments.

Epitaxial GaN nanostructures are developed, and the influence of the AlN buffer layer (temperature modulation) on material characteristics and optoelectronic device application is assessed. The AlN buffer layer was grown on a Si (111) substrate at varying temperatures (770–830 °C), followed by GaN growth using plasma-assisted molecular beam epitaxy. The investigation revealed that the comparatively lower temperature AlN buffer layer was responsible for stress and lattice strain relaxation and was realized as the GaN nano-obelisk structures. Contrarily, the increased temperature of the AlN growth led to the formation of GaN nanopyramidal and nanowax/wane structures. These grown GaN/AlN/Si heterostructures were utilized to develop photodetectors in a metal–semiconductor–metal geometry format. The performance of these fabricated optoelectronic devices was examined under ultraviolet illumination (UVA), where the GaN nano-obelisks-based device attained the highest responsivity of 118 AW−1. Under UVA (325 nm) illumination, the designed device exhibited a high detectivity of 1 × 1010 Jones, noise equivalent power of 1 × 10−12 WHz−1/2, and external quantum efficiency of 45,000%. The analysis revealed that the quality of the AlN buffer layer significantly improved the optoelectronic performance of the device.

The seismic assessment of rocking masonry structures is a complex task, due to the high sensitivity of the behavior to the characteristics of the input motion. The paper compares the results offered by different models and the reliability of widely used intensity measures. A displacement-based approach based on an incremental limit analysis of rigid blocks is proposed for the performance-based assessment of rocking masonry structures, such as: rocky structures (archeological remains, obelisks, columns, trilithons), arch-piers systems (e.g. triumphal arches, belfries), out-of-plane mechanisms of walls (standing out walls, façades in buildings or churches etc.) or artistic assets prone to overturn (pinnacles, statues etc.). The method is compatible with the format of the PERPETUATE performance-based assessment method for cultural heritage assets

Through an interdisciplinary study of the work of Jesuit Athanasius Kircher (1602–1680), the authors investigate the relationship between the cultural policies of the Roman Curia, the Jesuit order, religious diversity, and the aesthetic–spatial configuration of Rome during the early modern age. This paper shares in-depth observations of the recovery of ancient culture and its reworking in a post-reformist Christian age through architectural and spatial elements adopted to endorse the continuity of the ancient past and the Catholic reformistic universalistic aspirations. In this context, Kircher worked to decipher hieroglyphics on obelisks of the Imperial age but from Egyptian times. These defined a specific topography of space as a visual convergence of points: an urban geography of sacral and historical–political value and a connection with the memories of the Roman Empire and the most ancient religions of the ancient times.

The Neoproterozoic Aswan granites constitute a major post-collisional intrusive complex within the Egyptian Nubian Shield and represent one of Egypt’s most significant geological, geomorphological, and cultural landscapes. Integrated remote-sensing and radiological data are used to characterize their geological, geomorphological, and environmental attributes. Four granite suites are recognized in the Aswan area: greyish-black tonalites–granodiorites, coarse pink monzogranites–syenogranites, medium- to coarse-grained High Dam granites, and fine-grained granites. These lithologies exert a strong control on regional geomorphology, with structural fabrics—dominated by N–S and NE–SW joint sets and locally developed NE-trending shear zones—governing drainage patterns, landscape evolution, quarrying potential, and the distribution of radioelements. Integrated geomorphological and remote sensing analyses demonstrate that lithology and structural framework exert primary control on the Nile’s course and on the development of characteristic granite landforms, including inselbergs, exfoliation domes, joint-controlled valleys, steep canyons, and granitic island chains. PRISMA hyperspectral data further enhanced this framework by differentiating the rock units, delineating shear zones, and clearly identifying quarrying scars and associated landscape degradation. All remote-sensing interpretations were validated through detailed geological field investigations, ensuring accurate characterization of the granitic rocks and their modification by human activities. The granites show progressive differentiation from greyish-black granodiorites to coarse pink and fine-grained types, with U–Th–K enrichment and mean activities of 238 U (77.23 Bq/kg), 226 Ra (41.93 Bq/kg), 232 Th (73.07 Bq/kg), and 40 K (1281.3 Bq/kg), exceeding global averages. Radiological parameters record mean values of 131.35 nGy/h (absorbed dose), 0.16 mSv/y (annual effective dose), 275.82 Bq/kg (radium equivalent), hazard indices of 0.74 and 0.95, and a gamma index of 2.07. Fine-grained granites locally exceed indoor-use limits, High-Dam granites show moderate Th–K enrichment due to deformation, whereas greyish-black and most coarse pink granites (including Fila) remain within safety limits and are most suitable for quarrying. Overall, lithology and structural architecture—rather than external environmental factors—control mechanical behavior, landscape evolution, quarrying suitability, and radiological distribution across the Aswan granite province. Despite generally safe radiological levels, unregulated quarrying and rapid urban expansion have altered terrain and disrupted geomorphic integrity. These findings provide a framework for sustainable resource management, radiological safety evaluation, geomorphology-informed land-use planning, and preservation of Aswan’s unique geological and cultural heritage.

In 12 BCE, Augustus undertook the responsibility for the calendar, which had gradually fallen out of alignment with the true dates of solstices and equinoxes. Augustus’ calendar reform, entailing the introduction of a leap day every four years, coincided with the erection of a grand meridian in the Campus Martius, known in Latin as Horologium Augusti. This device utilized the obelisk of Psamtik II (6° century BCE) as its gnomon that casted its shadow upon a travertine floor inscribed with bronze reference marks. Despite the discovery of the obelisk in 18th century and partial excavation of the floor in 1980, comprehending its geometric intricacies, regarding both dimensions and positioning, remained a challenge due to the complexities of conducting precise geomatic measurements in subterranean environments. Consequently, uncertainties persisted regarding its operational mechanics, particularly regarding whether the marks denoted days or ecliptic degrees. This study presents accurate measurements and statistically rigorous analyses that enable a precise repositioning of the meridian and a careful reconstruction of its geometry. The results suggest that the marks likely denoted specific days of the year, as recalled by Pliny the Elder. This provides support to the hypothesis that the monument functioned as an empirical validation of Augustus’ calendrical reform. In addition, the great accuracy achieved in positioning represents a fundamental aid in the desirable scenario to continue excavations of the meridian.

This paper presents a detailed study of a sunk-relief scene from the Temple of Khonsu at Karnak. This scene has not yet been presented in a detailed publication although references have been made to it in several publications. This study revealed the ambiguity of two main elements of the scene actioned in Karnak temples in the reign of Herihor; the first is the lost dedicated obelisk of Herihor and the second is evidence of a new cult of king Amenhotep I and its dating according to his figuration in the scene as \"Imn-htp n bnrt\".