UC Santa Barbara

Abstract: Despite increasing racial diversity in the United States, and the particular growth of multiracial populations, questions about how children perceive others’ (bi)racial identities remain poorly understood. In two preregistered studies, we asked White and racially minoritized American children (N = 157; 4–11‐years old) and White and multiracial adults (N = 226) how acceptable it was for monoracial people (Black or White; Study 1) and/or biracial people (Black–White; Studies 1 and 2) to claim either a monoracial or biracial identity. Consistent with past research with adults, children said that monoracial people should claim (only) the monoracial identity which matched their ancestry. Judgements about biracial identity were more variable. White and multiracial adults (Study 2) reported that biracial targets could claim a racial identity that matched either or both of their parents, with biracial claims being evaluated most positively. Exploratory analyses on children's judgements about biracial people's identity claims (Study 1) revealed different patterns of development for White children and children from minoritized backgrounds. Whereas White children became more likely with age to report that all identity claims were acceptable, children from racially minoritized groups became more likely with age to endorse biracial targets who claimed a biracial identity. These findings suggest that children's own racial background and age may have a larger impact on their perceptions of biracial people's identities, compared to their perceptions of monoracial people's identities.

Hemodialysis for chronic kidney disease (CKD) relies on vascular access (VA) devices, such as arteriovenous fistulas (AVF), grafts (AVG), or catheters, to maintain blood flow. Nonetheless, unpredictable progressive vascular stenosis due to neointimal formation or complete occlusion from acute thrombosis remains the primary cause of mature VA failure. Despite emergent surgical intervention efforts, the lack of a reliable early detection tool significantly reduces patient outcomes and survival rates. This study introduces a soft, wearable device that continuously monitors blood flow for early detection of VA failure. Using thermal anemometry, integrated sensors noninvasively measure flow changes in large vessels. Bench testing with AVF and AVG models shows agreement with finite element analysis (FEA) simulations, while human and preclinical swine trials demonstrate the devices sensitivity. Wireless adaptation could enable at-home monitoring, improving detection of VA-related complications and survival in CKD patients.

An animal's diet breadth is a central aspect of its life history, yet the factors determining why some species have narrow dietary breadths (specialists) and others have broad dietary breadths (generalists) remain poorly understood. This challenge is pronounced in herbivorous insects due to incomplete host plant data across many taxa and regions. Here, we develop and validate machine learning models to predict pollen diet breadth in bees, using a bee phylogeny and occurrence data for 682 bee species native to the United States, aiming to better understand key drivers. We found that pollen specialist bees made an average of 72.9% of their visits to host plants and could be predicted with high accuracy (mean 94%). Our models predicted generalist bee species, which made up a minority of the species in our dataset, with lower accuracy (mean 70%). The models tested on spatially and phylogenetically blocked data revealed that the most informative predictors of diet breadth are plant phylogenetic diversity, bee species' geographic range, and regional abundance. Our findings also confirm that range size is predictive of diet breadth and that both male and female specialist bees mostly visit their host plants. Overall, our results suggest we can use visitation data to predict specialist bee species in regions and for taxonomic groups where diet breadth is unknown, though predicting generalists may be more challenging. These methods can thus enhance our understanding of plant-pollinator interactions, leading to improved conservation outcomes and a better understanding of the pollination services bees provide.

Bioinspired hydroxypyridinone (HOPO)functionalized materials are shown to display a remarkable capacity for stability and for chelating a wide array of metal ions. This allows for the synthesis of multifunctional networks with diverse physical properties when compared to traditional catechol systems. In the present study, we report a facile, one-pot synthesis of an amino HOPO ligand and simple, scalable incorporation into PEG-acrylate based networks via active ester chemistry. This modular network approach allows for fabrication of patterned HOPO containing networks which can chelate a range of metal ions, such as transition metals (Fe3+) and lanthanides (Ho3+, Tb3+), leading to modulation of mechanical, magnetic, and fluorescent properties. Moreover, networks with tailored, heterogeneous properties can be prepared through localization of metal ion incorporation in 3-dimensions via masking techniques, creating distinctly soft, hard, magnetic, and fluorescent domains.

AC plasmas directly excited within liquid hydrocarbons were investigated for the production of hydrogen and unsaturated C2 hydrocarbon in a recirculating liquid jet flow configuration. Arc discharges were excited at two different frequencies (60 Hz and 17.3 kHz) in C6-C8 hydrocarbons (hexane, cyclohexane, benzene, toluene, and xylene) to produce H2, C2H4, C2H2, and CH4, along with liquid and solid carbon byproducts. AC frequency was seen to modify the plasma properties and gas bubble formation dynamics, significantly influencing the efficiency and reaction pathway. Higher discharge frequency increased energy efficiency more than 2-fold by minimizing thermal losses and favored the production of hydrogenated compounds due to shorter reactant-plasma contact times. Further optimization of hexane conversion was achieved by introducing fluid flow around the plasma electrodes, which led to competitively low specific energy requirements (SERs) of 3.2 kWh/kg C2H4, 4.9 kWh/kg C2H2, and 24.3 kWh/kg H2. The effect of hydrocarbon feed chemistry was analyzed, showing that hexane and cyclohexane are preferable for C2 hydrocarbon syntheses, whereas aromatic hydrocarbons produce more H2. Gas bubble dynamics and liquid/solid products were analyzed using high-speed imaging, optical emission spectroscopy (OES), gas chromatography-mass spectrometry (GC-MS), scanning electron microscopy/transmission electron microscopy (SEM/TEM), and Raman spectroscopy. This work contributes to the understanding of plasma conversion mechanisms within liquids and demonstrates the potential for the energy-efficient transformation of hydrocarbons with plasma in unique reaction environments.

The distribution of counterions and dopants within electrically doped semicrystalline conjugated polymers, such as poly(3-hexylthiophene-2,5-diyl) (P3HT), plays a pivotal role in charge transport. The distribution of counterions in doped films of P3HT with controlled crystallinity was examined using polarized resonant soft X-ray scattering (P-RSoXS). The changes in scattering of doped P3HT films containing trifluoromethanesulfonimide (TFSI-) and 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ•-) as counterions to the charge carriers revealed distinct differences in their nanostructure. The scattering anisotropy of P-RSoXS from doped blends of P3HT was examined as a function of the soft X-ray absorption edge and found to vary systematically with the composition of crystalline and amorphous domains and by the identity of the counterion. A computational methodology was developed and used to simulate the soft X-ray scattering as a function of morphology and molecular orientation of the counterions. Modeling of the P-RSoXS at N and F K-edges was consistent with a structure where the conjugated plane of F4TCNQ•- aligns perpendicularly to that of the P3HT backbone in ordered domains. In contrast, TFSI- was distributed more uniformly between domains with no significant molecular alignment. The approach developed here demonstrates the capabilities of P-RSoXS in identifying orientation, structural, and compositional distributions within doped conjugated polymers using a computational workflow that is broadly extendable to other soft matter systems.

The mammalian cell membrane is embedded with biomolecular condensates of protein and lipid clusters, which interact with an underlying viscoelastic cytoskeleton network to organize the cell surface and mechanically interact with the extracellular environment. However, the mechanical and thermodynamic interplay between the viscoelastic network and liquid-liquid phase separation of 2-dimensional (2D) lipid condensates remains poorly understood. Here, we engineer materials composed of 2D lipid membrane condensates embedded within a thin viscoelastic actin network. The network generates localized anisotropic stresses that deform lipid condensates into triangular morphologies with sharp edges and corners, shapes unseen in many 3D composite gels. Kinetic coarsening of phase-separating lipid condensates accelerates the viscoelastic relaxation of the network, leading to an effectively softer composite material over intermediate time scales. We dynamically manipulate the membrane composition to control the elastic-to-viscous crossover of the network. Such viscoelastic composite membranes may enable the development of coatings, catalytic surfaces, separation membranes, and other interfaces with tunable spatial organization and plasticity mechanisms.

We report the metagenome-assembled genome of an ammonia-oxidizing archaeon that is closely related to Nitrosopumilus adriaticus NF5 but shows distinct genomic features compared to strain NF5.

This article draws on the researcher’s training and experience as a certified intimacy coordinator to examine how labour from professional sex work to intimacy coordination necessitates nuanced approaches to consent. What I call consent work – practices of communication, negotiation, and boundary setting – supports bodily autonomy while guiding portrayals of intimacy and nudity in film, television, theatre, and erotic media. I begin by discussing intimacy coordinators’ communication and consent frameworks to create context for my ensuing investigation. Next, utilizing data from interviews with online sex workers, I explore their sophisticated personal and community-oriented harm reduction techniques that, without formal training, dovetail with those in the intimacy coordination industry. Continuing my qualitative analysis, I describe the ways in which my interlocutors’ use of knowledge from consensual BDSM reflects the breadth of practices that inform consent work while illuminating the links between kink and intimacy coordination. Finally, I unpack how consent models remain entangled within systems of inequality and exclusion while owing much to marginalized communities’ contributions to contemporary understandings of bodily autonomy. Overall, consent work and its capacious lineage contribute to the expanding literature on intimacy coordination and highlight the field’s under-researched intersections with adult content creation.

The early initiation of binge-drinking and biological sex are critical risk factors for the development of affective disturbances and cognitive decline, as well as neurodegenerative diseases including Alzheimers disease. Further, a history of excessive alcohol consumption alters normal age-related changes in the pattern of protein expression in the brain, which may relate to an acceleration of cognitive decline. Here, we aimed to disentangle the interrelation between a history of binge-drinking during adolescence, biological sex and normal aging on the manifestation of negative affect, cognitive decline and associated biochemical pathology. To this end, adolescent male and female C57BL/6J mice (PND 28-29) underwent 30 days of alcohol binge-drinking using a modified drinking-in-the-dark (DID) paradigm. Then, mice were assayed for negative affect, sensorimotor gating and cognition at three developmental stages during adulthood-mature adulthood (6 months), pre-middle age (9 months) and middle age (12 months). Behavioural testing was then followed by immunoblotting to index the protein expression of glutamate receptors, neuropathological markers [Tau, p (Thr217)-Tau, p (Ser396)-Tau, BACE, APP, Aβ], as well as ERK activation within the entorhinal cortex, prefrontal cortex and amygdala. Across this age span, we detected only a few age-related changes in our measures of negative affect or spatial learning/memory in the Morris water maze and all of these changes were sex-specific. Prior adolescent binge-drinking impaired behaviour only during reversal learning in 9-month-old females and during radial arm maze testing in 12-month-old females. In contrast to behaviour, we detected a large number of protein changes related to prior binge-drinking history, several of which manifested as early as 6 months of age, with the prefrontal cortex particularly affected at this earlier age. While 6-month-old mice exhibited relatively few alcohol-related protein changes within the entorhinal cortex and amygdala, the number of alcohol-related protein changes within the entorhinal cortex increased with age, while the 12-month-old mice exhibited the largest number of protein changes within the amygdala. Approximately a third of the alcohol-related protein changes were sex-selective. Taken together, the results of our longitudinal study using a murine model of binge-drinking indicate that a prior history of heavy alcohol consumption, beginning in adolescence, is sufficient to induce what we presume to be latent changes in protein indices of cellular activity, glutamate transmission and neuropathology within key brain regions governing cognition, executive function and emotion that appear to precede the onset of robust behavioural signs of dysregulated affect and cognitive impairment.