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The genetic structure of marine animals that inhabit the seashore is affected by numerous factors. Of these, gene flow and natural selection during recruitment have strong influences on the genetic structure of seashore-dwelling species that have larval periods. Relative contributions of these two factors to the genetic structure of marine species would be determined mainly by the duration of larval stage. The relationship between larval period and genetic structure of population has been rarely studied in Korea. In this study, genetic variations of cytochrome oxidase subunit I (COI) were analyzed in two dominant species on rocky shore habitats in the Korean peninsula: periwinkle Littorina brevicula and acorn barnacle Fistulobalanus albicostatus. Both species are not strongly structured and may have experienced recent population expansion. Unlike periwinkle, however, barnacle populations have considerable genetic variation, and show a bimodal pattern of mismatch distribution. These results suggest that barnacle populations are more affected by local adaptation rather than gene flow via larval migration. The bimodal patterns of barnacle populations observed in mismatch distribution plots imply that they may have experienced secondary contact. Further studies on seashore-dwelling species are expected to be useful in understanding the evolution of the coastal ecosystem around Korean waters.

In remote sensing, change detection based on deep learning shows promising performance. However, collecting multi-temporal paired images for training a change detection model is costly. To solve this problem, unsupervised change detection methodologies have been proposed, but their performance is still low. In this article, we introduce the Unsupervised Change Detection Based on Image Reconstruction Loss (CDRL) and CDRL with Segment Anything (CDRL-SA). Requiring only single-temporal unlabelled images for training, CDRL uses the original and a photometrically transformed image as an unchanged pair, input to a bi-temporal transformer-based network for reconstructing the original image. During inference, changed pairs result in significant reconstruction loss, highlighting change areas. To capture finer details, we change the structure of CDRL to a transformer-based model and introduce the CutSwap method for effective training. Furthermore, this output is fused with the results of a recently proposed Segment Anything (SA) model to improve the final output. We assessed the performance of CDRL and CDRL-SA using the LEVIR change detection dataset and CLCD dataset, and the method achieved competitive results of 88.9 and 91.6 ACC for the respective datasets, demonstrating its effectiveness in unsupervised change detection tasks. [ABSTRACT FROM AUTHOR]

Activity-based detection of hydrogen sulfide in live cells can expand our understanding of its reactivity and complex physiological effects. We have discovered a highly efficient method for fluorescent probe activation, which is driven by H 2 S-triggered 1,6-elimination of an α-CF 3 -benzyl to release resorufin. In detecting intracellular H 2 S, 4-azido-(α-CF 3 )-benzyl resorufin offers significantly faster signal generation and improved sensitivity compared to 4-azidobenzyl resorufin. Computed free energy profiles for the 1,6-elimination process support the hypothesis that a benzylic CF 3 group can reduce the activation energy barrier toward probe activation. This novel probe design allows for near-real-time detection of H 2 S in HeLa cells under stimulation conditions., Competing Interests: DECLARATION OF INTEREST The authors declare no competing interests.

A unified strategy for the deoxygenative or desulfurative pyridylation of various alcohols and thiols has been developed through a single-electron transfer (SET) process of frustrated Lewis pairs (FLPs) derived from pyridinium salts and PtBu 3 . Mechanistic studies revealed that N-amidopyridinium salts serve as effective Lewis acids for the formation of FLPs with PtBu 3 , and the generated phosphine radical cation ionically couples with the in situ generated xanthate, eventually affording the alkyl radical through facile β-scission under photocatalyst-free conditions. The reaction efficiency was further accelerated by visible-light irradiation. This method is conceptually appealing by using encounter complexes in FLP chemistry to promote SET, which provides a previously unrecognized opportunity for the selective heteroarylation of a diverse range of alcohols and thiols with various functional groups, even in complex settings under mild reaction conditions., (© 2022 Wiley-VCH GmbH.)