Search for: All records

Abstract Tropical elevation gradients support highly diverse assemblages, but competing hypotheses suggest either peak species richness in lowland rainforests or at mid‐elevations. We investigated scolytine beetles—phloem, ambrosia and seed‐feeding beetles—along a tropical elevational gradient in Papua New Guinea.Highly standardised sampling from 200 to 3700 m above sea level (asl) identified areas of highest and lowest species richness, abundance and other biodiversity variables.Using passive flight intercept traps at eight elevations from 200 to 3500 m asl, we collected over 9600 specimens representing 215 species. Despite extensive sampling, species accumulation curves suggest that diversity was not fully exhausted.Scolytine species richness followed a unimodal distribution, peaking between 700 and 1200 m asl, supporting prior findings of highest diversity at low‐to‐mid elevations.Alternative models, such as a monotonous decrease from lowlands to higher elevations and a mid‐elevation maximum, showed lesser fit to our data. Abundance is greatest at the lowest sites, driven by a few extremely abundant species. The turnover rate—beta diversity between elevation steps—is greatest between the highest elevations.Among dominant tribes—Dryocoetini, Xyleborini and Cryphalini—species richness peaked between 700 and 2200 m asl. Taxon‐specific analyses revealed distinct patterns:Euwallaceaspp. abundance uniformly declined with elevation, while other genera were driven by dominant species at different elevations.Coccotrypesand phloem‐feedingCryphalushave undergone evolutionary radiations in New Guinea, with many species still undescribed. Species not yet known to science are most likely to be found at lower and middle elevations, where overall diversity is highest. 

Cellular signaling networks are modulated by multiple protein-protein interaction domains that coordinate extracellular inputs and processes to regulate cellular processes. Several of these domains recognize short linear motifs, or SLiMs, which are often highly conserved and are closely regulated. One such domain, the Src homology 3 (SH3) domain, typically recognizes proline-rich SLiMs and is one of the most abundant SLiM-binding domains in the human proteome. These domains are often described as quiteversatile, and indeed, SH3 domains can bind ligands in opposite orientations dependent on target sequence. Furthermore, recent work has identified diverse modes of binding for SH3 domains and a wide variety of sequence motifs that are recognized by various domains. Specificity is often attributed to the RT and nSrc loops near the peptide-binding cleft in this domain family, particularly for Class I binding, which is defined as RT and nSrc loop interactions with the N-terminus of the ligand. Here, we used the Src and Abl SH3 domains as a model to further investigate the role of the RT and nSrc loops in SH3 specificity. We created chimeric domains with both the RT and nSrc loop sequences swapped between these SH3 domains, and used fluorescence anisotropy assays to test how relative binding affinities were affected for Src SH3- and Abl SH3-specific ligands. We also used Alphafold–Multimer to model our SH3:peptide complexes in combination with molecular dynamics simulations. We identified a position that contributes to the nSrc loop conformation in Src SH3, the amino acid immediately following a highly conserved Trp that creates a hydrophobic pocket critical for SH3 ligand recognition. We defined this as the WX motif, where X = Trp for Src and Cys for Abl. A broad importance of this position for modulating nSrc loop conformation in SH3 domains is suggested by analyses of previously deposited SH3 structures, multiple sequence alignment of SH3 domains in the human proteome, and our biochemical and computational data of mutant Src and Abl SH3 domains. Overall, our work uses experimental approaches and structural modeling to better understand specificity determinants in SH3 domains. 

This paper proposes two contributions to the literature on the social acceptance (SA) of energy systems and public perceptions of renewable energy (RE) transitions. The first contribution is methodological, recognizing more effective and inclusive forms of engagement begin with building reciprocal relationships and collaborative research partnerships operationalizing the tenets of energy justice. Employing these methodological recommendations, we conducted a collaborative, inclusive, and equitable research design and engagement practice by collaborating with Tribal members on research with expressly mutual benefits. In this work, a years-long collaboration of Tribal members and non-Tribal researchers developed a methodology to survey respondents at an accessible and culturally relevant community event to learn about preferences and perceived barriers to transitioning to RE. A second contribution is empirical. The results suggest shared priorities for energy solutions that enhance energy sovereignty, i.e., community control and ownership of energy services provisioning. They also demonstrate widespread awareness regarding barriers to a RE transition and simultaneously, some potential misperceptions about the challenges to transition. This study reinforces the need for SA research to move beyond asking what technologies receive public support and where those technologies should be sited to consider how access and transparency in planning processes, collaboration, engagement, development, ownership, and benefits are organized and can be radically reconfigured to enable the just transition to a decarbonized energy system. 

GM1 gangliosidosis is a lysosomal storage disorder caused by deficiency of β-galactosidase (βgal) and subsequent accumulation of GM1 ganglioside in lysosomes. One of the pathological aspects of GM1 gangliosidosis, and other storage disorders, is impaired autophagy, i.e., a reduced fusion of autophagosomes and lysosomes to degrade cellular waste. Enzyme replacement therapy (ERT) can effectively treat systemic deficiency but is limited by immunogenicity and shortened half-life of intravenously administered enzyme. In this paper, we report a hyaluronic acid-b-polylactic acid (HA-PLA) polymersome delivery system that can achieve an enzyme-responsive and sustained delivery of βgal to promote the cell’s self-healing process of autophagy. HA-PLA polymersomes have an average diameter of 138.0 ± 17.6 nm and encapsulate βgal with an efficiency of 77.7 ± 3.4%. In the presence of model enzyme Hyaluronidase, HA-PLA polymersomes demonstrate a two-fold higher release of encapsulant than without enzyme. We also identified reduced autophagy in a cellular model of GM1 Gangliosidosis (GM1SV3) compared to healthy cells, illustrated using immunofluorescence. Enhanced autophagy was reported in GM1SV3 cells treated with βgal-loaded polymersomes. Most notably, the fusion of lysosomes and autophagosomes in GM1SV3 cells returned to normal levels of healthy cells after 24 h of polymersome treatment. The HA-PLA polymersomes described here can provide a promising delivery system to treat GM1 Gangliosidosis. 

Abstract Biological and biomedical research is increasingly conducted in large, interdisciplinary collaborations to address problems with significant societal impact, such as reducing antibiotic resistance, identifying disease sub-types, and identifying genes that control for drought tolerance in plants. Many of these projects are data driven and involve the collection and analysis of biological data at a large-scale. As a result, life-science projects, which are frequently diverse, large and geographically dispersed, have created unique challenges for collaboration and training. We examine the communication and collaboration challenges in multidisciplinary research through an interview study with 20 life-science researchers. Our results show that both the inclusion of multiple disciplines and differences in work culture influence collaboration in life science. Using these results, we discuss opportunities and implications for designing solutions to better support collaborative tasks and workflows of life scientists. In particular, we show that life science research is increasingly conducted in large, multi-institutional collaborations, and these large groups rely on “mutual respect” and collaboration. However, we found that the interdisciplinary nature of these projects cause technical language barriers and differences in methodology affect trust. We use these findings to guide our recommendations for technology to support life science. We also present recommendations for life science research training programs and note the necessity for incorporating training in project management, multiple language, and discipline culture. 

Millions of individuals in the United States without a computer or broadband at their residence must rely on public libraries for their Internet access. Drawing on a rich data set of interviews and participant observation at three public libraries, we explore how individuals navigate these complex settings and how they profoundly shape their digital lives and experiences, one we characterize as digital home-lessness. In this article, we identify three themes that characterize the relationship between library computer use and digital home-lessness: lifeline encompasses the diverse set of activities that require computer and broadband access; negotiating access focuses on usability, privacy, and security disadvantages among these users; and risky business concentrates on the multiplicities of insecure Internet and computing practices exacerbated by low technological capital. Our findings push forward literature on the digital divide by illuminating how the experience of digital home-lessness limits social inclusion and reproduces socioeconomic inequality. 

Abstract Anticipated future reductions in aerosol emissions are expected to accelerate warming and substantially change precipitation characteristics. Therefore, it is vital to identify the existing patterns and possible future pathways of anthropogenic aerosol reductions. The COVID-19 pandemic prompted abrupt, global declines in transportation and industrial activities, providing opportunities to study the aerosol effects of pandemic-driven emissions changes. Here, measurements of aerosol optical depth (AOD) from two satellite instruments were used to characterize aerosol burdens throughout 2020 in four Northern Hemisphere source regions (Eastern & Central China, the United States, India, and Europe). In most regions, record-low measures of AOD persisted beyond the earliest ‘lockdown’ periods of the pandemic. Record-low values were most concentrated during the boreal spring and summer months, when 56% to 72% of sampled months showed record-low AOD values for their respective regions. However, in India and Eastern & Central China, the COVID-19 AOD signature was eclipsed by sources of natural variability (dust) and a multi-year trend, respectively. In the United States and Europe, a likely COVID-19 signal peaks in the summer of 2020, contributing as much as −.01 to −.03 AOD units to observed anomalies.