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Electron Glass Phase with Resilient Zhang-Rice Singlets in LiCu3O3
Full text linkLiCu_{3}O_{3} is an antiferromagnetic mixed valence cuprate where trilayers of edge-sharing Cu(II)O (3d^{9}) are sandwiched in between planes of Cu(I) (3d^{10}) ions, with Li stochastically substituting Cu(II). Angle-resolved photoemission spectroscopy (ARPES) and density functional theory reveal two insulating electronic subsystems that are segregated in spite of sharing common oxygen atoms: a Cu d_{z^{2}}/O p_{z} derived valence band (VB) dispersing on the Cu(I) plane, and a Cu 3d_{x^{2}-y^{2}}/O 2p_{x,y} derived Zhang-Rice singlet (ZRS) band dispersing on the Cu(II)O planes. First-principle analysis shows the Li substitution to stabilize the insulating ground state, but only if antiferromagnetic correlations are present. Li further induces substitutional disorder and a 2D electron glass behavior in charge transport, reflected in a large 530 meV Coulomb gap and a linear suppression of VB spectral weight at E_{F} that is observed by ARPES. Surprisingly, the disorder leaves the Cu(II)-derived ZRS largely unaffected. This indicates a local segregation of Li and Cu atoms onto the two separate corner-sharing Cu(II)O_{2} sub-lattices of the edge-sharing Cu(II)O planes, and highlights the ubiquitous resilience of the entangled two hole ZRS entity against impurity scattering
Indigenous Co-Stewardship and the “Rashomon Effect”
Full text linkThe author applies principles from the classic film "Rashomon" to improve co-stewardship efforts between Indigenous People / Tribes and government agencies
Gut dysbiosis was inevitable, but tolerance was not: temporal responses of the murine microbiota that maintain its capacity for butyrate production correlate with sustained antinociception to chronic morphine.
Full text linkThe therapeutic benefits of opioids are compromised by the development of analgesic tolerance, which necessitates higher dosing for pain management thereby increasing the liability for drug dependence and addiction. Rodent models indicate opposing roles of the gut microbiota in tolerance: morphine-induced gut dysbiosis exacerbates tolerance, whereas probiotics ameliorate tolerance. Not all individuals develop tolerance, which could be influenced by differences in microbiota, and yet no study design has capitalized upon this natural variation. We leveraged natural behavioral variation in a murine model of voluntary oral morphine self-administration to elucidate the mechanisms by which microbiota influences tolerance. Although all mice shared similar morphine-driven microbiota changes that largely masked informative associations with variability in tolerance, our high-resolution temporal analyses revealed a divergence in the progression of dysbiosis that best explained sustained antinociception. Mice that did not develop tolerance maintained a higher capacity for production of the short-chain fatty acid (SCFA) butyrate known to bolster intestinal barriers and promote neuronal homeostasis. Both fecal microbial transplantation (FMT) from donor mice that did not develop tolerance and dietary butyrate supplementation significantly reduced the development of tolerance independently of suppression of systemic inflammation. These findings could inform immediate therapies to extend the analgesic efficacy of opioids
Respectful Tribal Consultation Protocols from Native California Perspectives
Full text linkFor public land management agency managers and staff, co-stewardship and co-management may just be another element of the job, but for Native peoples it’s their very life. This article details respectful Tribal consultation from Native California perspectives, the foundation upon which successful co-stewardship and co-management of public lands rests. For those managers and staff who are unfamiliar with the Tribes and Tribal communities in their area, we begin by providing a note about naming terminology and some sources for identifying Native groups who are/were historically located in a given area. From there, after introducing the concept of respectful Tribal consultation, we describe the relationship and trust-building process between Tribal governments and their designated representatives and public land management agency managers and other staff, relationships that must be proven and nurtured across time, rather than initiated as time- and process-challenged business arrangements. We also explicate “community protocol,” the etiquette, customs, and traditional ways of interacting that support, protect, and promote the community, so once you get to the “business” part of the relationship, there can be equality, honor, and respect within it. Next, we provide links to best-practice models, resources, and agreements for effective collaboration and consultation in the stewardship of public lands. We end by making a case for the integration of natural and cultural “resources” in the procedures and policies under which Tribal consultation and co-stewardship and co-management of public lands takes place. Many of these processes are time tested and active in current co-management projects
The California Indian Basketweavers Association and Its Organizationally Based Land Stewardship and Management Initiatives
Full text linkThis article will detail the wide-ranging and effective land stewardship and management initiatives by a Native California organization, the California Indian Basketweavers Association (CIBA). Founded in 1992 to “preserve, promote and perpetuate California Indian basketry traditions,” CIBA has a proud history of working with public land-holding agencies to initiate policy changes around the management and gathering of basketry plants on those lands, including the reduction and sometimes outright elimination of pesticide spraying, the encouragement of cultural burning, and an unprecedented, joint US Forest Service and Bureau of Land Management gathering policy for ethnobotanic materials. Currently, CIBA spearheads training programs in land stewardship and cultural burning through its Following the Smoke II and Rekindling Culture and Fire projects. It has also inspired the establishment of other Native basketweavers associations in various regions of the US
Rethinking microbial carbon use efficiency in soil models
Full text linkSoil models include a key parameter known as carbon use efficiency, which impacts estimates of global carbon storage by determining the flow of carbon into soil pools versus the atmosphere. Microbial-explicit versions of these models are due for an update that recasts carbon use efficiency as an output variable emerging from microbial metabolism
What Matters Most to Drayage Companies When Considering a Zero-Emission Truck: Insights from Small and Large Fleet Operators
Full text linkDrayage trucks (i.e., heavy-duty trucks that move containers and bulk freight between ports and rail facilities, distribution centers, and other nearby locations) are a critical part of port operations, however, they also adversely affect air quality. In California, drayage fleets are facing strict regulatory pressure under the Advanced Clean Fleets (ACF) regulations. Starting in January 2024, all newly registered drayage trucks in the CARB Online System must be zeroemission vehicles (ZEVs), so either a battery electric truck (BET) or hydrogen fuel cell electric truck (HFCET). By 2035, every drayage truck operating in California must be zeroemission
Evidence for microbially-mediated tradeoffs between growth and defense throughout coral evolution.
Full text linkBACKGROUND: Evolutionary tradeoffs between life-history strategies are important in animal evolution. Because microbes can influence multiple aspects of host physiology, including growth rate and susceptibility to disease or stress, changes in animal-microbial symbioses have the potential to mediate life-history tradeoffs. Scleractinian corals provide a biodiverse, data-rich, and ecologically-relevant host system to explore this idea. RESULTS: Using a comparative approach, we tested if coral microbiomes correlate with disease susceptibility across 425 million years of coral evolution by conducting a cross-species coral microbiome survey (the Global Coral Microbiome Project) and combining the results with long-term global disease prevalence and coral trait data. Interpreting these data in their phylogenetic context, we show that microbial dominance predicts disease susceptibility, and traced this dominance-disease association to a single putatively beneficial symbiont genus, Endozoicomonas. Endozoicomonas relative abundance in coral tissue explained 30% of variation in disease susceptibility and 60% of variation in microbiome dominance across 40 coral genera, while also correlating strongly with high growth rates. CONCLUSIONS: These results demonstrate that the evolution of Endozoicomonas symbiosis in corals correlates with both disease prevalence and growth rate, and suggest a mediating role. Exploration of the mechanistic basis for these findings will be important for our understanding of how microbial symbioses influence animal life-history tradeoffs
Synapse-specific catecholaminergic modulation of neuronal glutamate release
Full text linkNorepinephrine in vertebrates and its invertebrate analog, octopamine, regulate the activity of neural circuits. We find that, when hungry, Drosophila larvae switch activity in type II octopaminergic motor neurons (MNs) to high-frequency bursts, which coincide with locomotion-driving bursts in type I glutamatergic MNs that converge on the same muscles. Optical quantal analysis across hundreds of synapses simultaneously reveals that octopamine potentiates glutamate release by tonic type Ib MNs, but not phasic type Is MNs, and occurs via the Gq-coupled octopamine receptor (OAMB). OAMB is more abundant in type Ib terminals and acts through diacylglycerol and its target Unc13A, a key component of the glutamate release machinery. Potentiation varies significantly-by up to 1,000%-across synapses of a single Ib axon, with synaptic Unc13A levels determining both release probability and potentiation. We propose that a dual molecular mechanism-an upstream neuromodulator receptor and a downstream transmitter release controller-fine-tunes catecholaminergic modulation so that strong tonic synapses exhibit large potentiation, while weaker tonic and all phasic synapses maintain consistency, yielding a sophisticated regulation of locomotor behavior
Defining Mechanistic Links Between the Non-Coding Variant rs17673553 in CLEC16A and Lupus Susceptibility.
No full textSystemic lupus erythematosus (SLE) is a complex autoimmune disorder characterized by widespread inflammation and autoantibody production. Its development and progression involve genetic, epigenetic, and environmental factors. Although genome-wide association studies (GWAS) have repeatedly identified a susceptibility signal at 16p13, its fine-scale source and its functional and mechanistic role in SLE remain unclear. We used bioinformatics to prioritize likely functional variants and validated the top candidate through various experimental techniques, including clustered regularly interspaced short palindromic repeats (CRISPR)-based genome editing in B cells. To assess the functional impact of the proposed causal variant in C-type lectin domain family 16, member A (CLEC16A), we compared autophagy levels between wild-type (WT) and knock-out (KO) cells. Systematic bioinformatics analysis identified the highly conserved non-coding intronic variant rs17673553, with the risk allele apparently affecting enhancer function and regulating several target genes, including CLEC16A itself. Luciferase reporter assays followed by chromatin immunoprecipitation-quantitative polymerase chain reaction (ChIP-qPCR) validated this enhancer activity, demonstrating that the risk allele increases the binding of enhancer histone marks (H3K27ac and H3K4me1), the CTCF-binding factor, and key immune transcription factors (GATA3 and STAT3). Knock-down of GATA3 and STAT3 via siRNA led to a significant decrease in CLEC16A expression. These regulatory effects on the target gene were further confirmed using CRISPR-based genome editing and CRISPR-dCas9-based epigenetic activation/silencing. Functionally, WT cells exhibited higher levels of starvation-induced autophagy compared to KO cells, highlighting the role of CLEC16A and the rs17673553 locus in autophagy regulation. These findings suggest that the rs17673553 locus-particularly the risk allele-drives significant allele-specific chromatin modifications and binding of multiple transcription factors, thereby mechanistically regulating the expression of target autophagy-associated genes, including CLEC16A itself. This mechanism could potentially explain the association between rs17673553 and SLE, and could underlie the signal at 16p13