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The Caribbean Through-Flow (CTF) is a critical chokepoint for North and South Atlantic waters that form the North Atlantic western boundary current system and the upper ocean limb of the Atlantic Meridional Overturning Circulation. While the circulation and energetics of the CTF have been well studied, its water mass transformations remain poorly constrained. Using over 7700 Argo float profiles from 2014 to 2024, we document a prominent westward modification in water mass structure across the Caribbean Sea. From the eastern to western Caribbean, we observe systematic increases in ocean heat content, a deepening of isopycnals, and a freshening and deepening of the subsurface salinity maximum. These changes result in a net mid-depth (~50–500 m) density reduction of 0.40 ± 0.27 kg m-3. We hypothesize that regional variations in mesoscale eddy activity, complex bathymetry, and meridional wind stress curl gradients drive this transformation. The resulting water mass structure has critical implications for regional climate, weather, ecosystems, and sea level rise, as it modifies the density and stratification of source waters entering the Gulf of Mexico and North Atlantic western boundary current system. Our findings highlight the importance of internal Caribbean processes in shaping upper-ocean heat and salt transport in the Atlantic and underscore the need for sustained in situ observations in the region and targeted modeling analyses of the underlying modification processes. 

Not AvailThe on-surface synthesis of various organic compounds relies on the self-assembly and subsequent dissociation of halogen-substituted organic molecules for polymerization and functionalization. Here, we demonstrate that the photolytic disassembly and dissociation of bromobenzene molecules within magic-sized tetramer nanoclusters are influenced by halogen bonding on the Cu(111) surface. We explain this phenomenon using a combination of two-photon photoemission spectroscopy, scanning tunneling microscopy, and density functional theory computations. The interactions that determine the preferred cluster sizes of trimers to pentamers arise from a combination of halogen bonding and weak hydrogen bonding. Surface adsorption enhances halogen bonding while weakening the weak hydrogen bonds in the nanoclusters. The most stable tetramers are constructed from a trimer foundation that employs halogen-3 synthons with an exterior fourth molecule. The exterior bromobenzene in this tetramer may detach from the trimer core cluster or undergo dehalogenation before the other bromobenzene molecules under irradiation. The work function of the Cu(111) surface is significantly decreased by the presence of a tetramer. This reduction facilitates the photodissociation of bromobenzene by allowing electrons from the surface to occupy the antibonding molecular orbitals associated with the C–Br bond. The work function increases steadily as smaller clusters and dissociated bromobenzene (phenyl and Br) are formed photolytically. The molecules of the trimers are not photodissociated because the energy levels of the C–Br antibonding orbitals in the trimer core are notably higher in energy than those of the exterior molecule in the tetramer. Our study highlights the potential of weak noncovalent interactions to guide selective photolytic reactions on surfaces.able 

ABSTRACT Technologies for large‐scale manufacturing of viral vectors for gene therapies, such as tangential flow filtration and membrane chromatography, are under development. In these early stages of process development, techno‐economic analyses are useful for identifying membrane properties yielding the greatest impact on process performance. In this study, we adapted a techno‐economic framework used for monoclonal antibody capture for adeno‐associated viral vector purification. We added mechanistic models to simulate flux decline during harvesting and separating full and empty capsids during polishing. Graphical user interfaces were added to help users explore the design search space. We selected a base process and manipulated selected variables to see their impact on large‐scale manufacturing performance. These sensitivity analyses revealed that, under the selected process conditions, increasing module capacity reduces cost of goods more effectively than increasing operational flux in tangential flow membrane filtration modules for virus harvesting. Membrane chromatography columns with relatively low dynamic binding capacity (DBC) and short residence time (RT) offered similar or better economic performance than those with high DBC and long RT. Additionally, the difference in equilibrium solid‐phase concentration between full and empty capsids as a function of salt concentration significantly affects purity. 

Abstract Continuous manufacturing platforms and membrane chromatography are process technologies with the potential to reduce production costs and minimize process variability in monoclonal antibody production. This study presents a simulation and optimization framework to perform techno‐economic analyses of these strategies. Multi‐objective optimization was used to compare batch and continuous multicolumn operating modes and membrane and resin process alternatives, revealing performance differences in productivity and cost of goods attributed to variations in dynamic binding capacity, media geometry, and process residence time. From the set of optimal process configurations, we selected one membrane and one resin platform alternative yielding the highest net present values to undergo sensitivity analyses involving variations in batch cadence and product selling price. For the scenarios considered in this work, membrane continuous platforms showed benefits in the cost of goods and process mass intensity. Their shorter residence time compared to resins positions them as a viable alternative for single‐use capture chromatography. Moreover, this low residence time makes membrane platforms more flexible to changes in throughput, an essential feature for integrating capture into fully continuous processes. 

Abstract We present the first chromosome-level genome assembly for Bombus pensylvanicus, a historically widespread native pollinator species that was distributed across eastern North America but has subsequently undergone declines in range area and local relative abundance. This species has been of significant interest as a model for understanding both patterns and possible causes of bumble bee decline in the region, including the role of genetic variation. Here we present a chromosome-level reference genome assembled using Pacific Biosciences singe-molecule HiFi sequences and Hi-C data and annotated using evidence derived from RNA sequencing of multiple tissue types. The B. pensylvanicus genome has a total length of ∼352.6 Mb and was assembled into a total of 224 scaffolds, with 19 primary pseudomolecules representing putative chromosomes and an N50 = 14.872 Mb. Annotation with the Eukaryotic Genome Annotation Pipeline—External (EGAPx) identified 11,411 genes (10,263 protein coding), and BUSCO analysis of 5,991 Hymenoptera-specific BUSCO groups indicated a completeness for the proteins of 99.0% (98.6% single-copy, 0.5% duplicated) and for the genome of 98.5% (98.2% single-copy, 0.3% duplicated). We present synteny analyses with other recently assembled Bombus genomes representing different subgenera and examine the distribution of repetitive regions of the genome relative to the distribution of genes and noncoding RNAs. 

Time-resolved spectroscopy is an important tool for probing photochemically induced nonequilibrium dynamics and energy transfer. Herein, a method is developed for the ab initio simulation of vibronic spectra and dynamical processes. This framework utilizes the recently developed nuclear–electronic orbital time-dependent configuration interaction (NEO-TDCI) approach, which treats all electrons and specified nuclei quantum mechanically on the same footing. A strategy is presented for calculating time-resolved vibrational and electronic absorption spectra from any initial condition. Although this strategy is general for any TDCI implementation, utilizing the NEO framework allows for the explicit inclusion of quantized nuclei, as illustrated through the calculation of vibrationally hot spectra. Time-resolved spectra produced by either vibrational or electronic Rabi oscillations capture ground-state absorption, stimulated emission, and excited-state absorption between vibronic states. This methodology provides the foundation for fully ab initio simulations of multidimensional spectroscopic experiments. 

Summer circulation and moisture patterns in the Southeast United States are controlled by the position of the North Atlantic subtropical high. In a warming climate, the subtropical high is projected to strengthen and expand west, but there remains uncertainty regarding its variability and linkages to natural drivers. Here, we use a tree-ring network across the Southeast United States to reconstruct the relative intensity of the pressure gradient across the subtropical high’s western flank over the past 870 years. Variations in the flank’s position and the pressure gradient have been a major driver of the hydroclimate—including creating a Southeast-Caribbean moisture dipole—since 1140 CE. We document a significant increase in flank positional variability since 1900 CE, with westward migrations becoming more extreme. Likewise, major volcanic eruptions cause a multiyear period of westward positioning, leading to distinct regional moisture gradients. Our record highlights important changes in flank behavior, which has important implications for water resource management in a warming world.