There is increasing evidence that interactions between microbes and their hosts not only play a role in determining health and disease but also in emotions, thought, and behavior. Built environments greatly influence microbiome exposures because of their built - in highly specific microbiomes coproduced with myriad metaorganisms including humans, pets, plants, rodents, and insects. Seemingly static built structures host complex ecologies of microorganisms that are only starting to be mapped. These microbial ecologies of built environments are directly and interdependently affected by social, spatial, and technological norms. Advances in technology have made these organisms visible and forced the scientific community and architects to rethink gene-environment and microbe interactions respectively. Thus, built environment design must consider the microbiome, and research involving host-microbiome interaction must consider the built - environment. This paradigm shift becomes increasingly important as evidence grows that contemporary built environments are steadily reducing the microbial diversity essential for human health, well - being, and resilience while accelerating the symptoms of human chronic diseases including environmental allergies, and other more life - altering diseases. New models of design are required to balance maximizing exposure to microbial diversity while minimizing exposure to human - associated diseases. Sustained trans - disciplinary research across time (evolutionary, historical, and generational) and space (cultural and geographical) is needed to develop experimental design protocols that address multigenerational multispecies health and health equity in built environments.

Alka(e)nes are produced by many living organisms and exhibit diverse physiological roles, reflecting a high functional versatility. Alka(e)nes serve as waterproof wax in plants, communicating pheromones for insects, and microbial signaling molecules in some bacteria. Although alka(e)nes have been found in cyanobacteria and algal chloroplasts, their importance for photosynthetic membranes has remained elusive. In this study, we investigated the consequences of the absence of alka(e)nes on membrane lipid composition and photosynthesis using the cyanobacterium Synechocystis PCC6803 as a model organism. By following the dynamics of membrane lipids and the photosynthetic performance in strains defected and altered in alka(e)ne biosynthesis, we show that drastic changes in the glycerolipid contents occur in the absence of alka(e)nes, including a decrease in the membrane carotenoid content, a decrease in some digalactosyldiacylglycerol (DGDG) species and a parallel increase in monogalactosyldiacylglycerol (MGDG) species. These changes are associated with a higher susceptibility of photosynthesis and growth to high light in alka(e)ne-deficient strains. All these phenotypes are reversed by expressing an algal photoenzyme producing alka(e)nes from fatty acids. Therefore, alkenes, despite their low abundance, are an essential component of the lipid composition of membranes. The profound remodeling of lipid composition that results from their absence suggests that they play an important role in one or more membrane properties in cyanobacteria. Moreover, the lipid compensatory mechanism observed is not sufficient to restore normal functioning of the photosynthetic membranes, particularly under high light intensity. We conclude that alka(e)nes play a crucial role in maintaining lipid homeostasis of thylakoid membranes, thereby contributing to the proper functioning of photosynthesis, particularly under elevated light intensities.

The magnetic and structural properties of the recently discovered pnictogen/chalcogen-free superconductor LaFeSiH have been investigated by 57Fe synchrotron M & ouml;ssbauer source spectroscopy, X-ray and neutron powder diffraction, and 29Si nuclear magnetic resonance spectroscopy. In contrast with earlier work suggesting the presence of an orthorhombic and magnetic ground state as in underdoped Fe -based pnictides, our results unambiguously establish that LaFeSiH is in fact similar to strongly overdoped Fe -based pnictides: there is no magnetic order (including under hydrostatic pressure up to 18.8 GPa), nor even fluctuating local moments and the system remains tetragonal down to 2 K. This raises the prospect of enhancing the Tc of LaFeSiH by reducing its carrier concentration through appropriate chemical substitutions.

The lattice dynamics of the superconducting materials LaFeSiH and LaFeSiO 1 - delta as well as their intermetallic precursor LaFeSi are investigated by polarized Raman spectroscopy and first-principles calculations, together with X-ray and advanced electron diffraction techniques for their structural analysis. We find that the Fe-dominated Raman-active modes reflect the chemical peculiarities of these silicides compared to their pnictide counterparts, with enhanced structural couplings between the FeSi layer and the spacer that can be related to the ionic vs . covalent character of the latter. In addition, we find signatures of enhanced electron-phonon coupling for some of the Raman-active modes. Beyond that, our study reveals intriguing Fe-based Raman features as well as structural subtleties in LaFeSiH suggesting that this superconductor may formally be non-centrosymmetric.

The emergence of alternative stable states in forest systems has significant implications for the functioning and structure of the terrestrial biosphere, yet empirical evidence remains scarce. Here, we combine global forest biodiversity observations and simulations to test for alternative stable states in the presence of evergreen and deciduous forest types. We reveal a bimodal distribution of forest leaf types across temperate regions of the Northern Hemisphere that cannot be explained by the environment alone, suggesting signatures of alternative forest states. Moreover, we empirically demonstrate the existence of positive feedbacks in tree growth, recruitment and mortality, with trees having 4-43% higher growth rates, 14-17% higher survival rates and 4-7 times higher recruitment rates when they are surrounded by trees of their own leaf type. Simulations show that the observed positive feedbacks are necessary and sufficient to generate alternative forest states, which also lead to dependency on history (hysteresis) during ecosystem transition from evergreen to deciduous forests and vice versa. We identify hotspots of bistable forest types in evergreen-deciduous ecotones, which are likely driven by soil-related positive feedbacks. These findings are integral to predicting the distribution of forest biomes, and aid to our understanding of biodiversity, carbon turnover, and terrestrial climate feedbacks.

Reservoirs exert a profound influence on the cycling of dissolved organic matter (DOM) in inland waters by altering flow regimes. Biological incubations can help to disentangle the role that microbial processing plays in the DOM cycling within reservoirs. However, the complex DOM composition poses a great challenge to the analysis of such data. Here we tested if the interpretable machine learning (ML) methodologies can contribute to capturing the relationships between molecular reactivity and composition. We developed time-specific ML models based on 7-day and 30-day incubations to simulate the biogeochemical processes in the Three Gorges Reservoir over shorter and longer water retention periods, respectively. Results showed that the extended water retention time likely allows the successive microbial degradation of molecules, with stochasticity exerting a non-negligible effect on the molecular composition at the initial stage of the incubation. This study highlights the potential of ML in enhancing our interpretation of DOM dynamics over time.

A bright (m(F150W,AB) = 24 mag), z = 1.95 supernova (SN) candidate was discovered in JWST/NIRCam imaging acquired on 2023 November 17. The SN is quintuply imaged as a result of strong gravitational lensing by a foreground galaxy cluster, detected in three locations, and remarkably is the second lensed SN found in the same host galaxy. The previous lensed SN was called "Requiem," and therefore the new SN is named "Encore." This makes the MACS J0138.0-2155 cluster the first known system to produce more than one multiply imaged SN. Moreover, both SN Requiem and SN Encore are Type Ia SNe (SNe Ia), making this the most distant case of a galaxy hosting two SNe Ia. Using parametric host fitting, we determine the probability of detecting two SNe Ia in this host galaxy over a similar to 10 yr window to be approximate to 3%. These observations have the potential to yield a Hubble constant (H-0) measurement with similar to 10% precision, only the third lensed SN capable of such a result, using the three visible images of the SN. Both SN Requiem and SN Encore have a fourth image that is expected to appear within a few years of similar to 2030, providing an unprecedented baseline for time-delay cosmography.