pH variations enable guanine crystal formation within iridosomes.

Many animals produce vivid colors by reflecting and amplifying light with stacked guanine crystals within membrane-bound organelles called iridosomes. While the presence of guanine crystals in iridosomes is well documented, the mechanisms facilitating the accumulation of water-insoluble guanine and driving its crystallization remain unclear. Here we used cryo-electron microscopy, live-cell pH imaging, pharmacological perturbations and spectroscopy to study iridosome maturation in zebrafish.

Molecular Footprints of Quaternary Climate Fluctuations in the Circumpolar Tundra Shrub Dwarf Birch.

The Arctic tundra biome is undergoing rapid shrub expansion ('shrubification') in response to anthropogenic climate change. During the previous ~2.6 million years, glacial cycles caused substantial shifts in Arctic vegetation, leading to changes in species' distributions, abundance and connectivity, which have left lasting impacts on the genetic structure of modern populations.

Flash Communication: Boron K‑edge XAS and TDDFT Studies of Covalent Metal-Ligand Bonding in Ni(CBH).

Ligand K-edge X-ray absorption spectroscopy (XAS), a technique that can measure variations in covalent metal-ligand bonding, has rarely been used to assess covalency in complexes containing metal-boron bonds. Here we describe ligand K-edge XAS and TDDFT studies of the Ni dicarbollide complex Ni-(CBH) () and the Ni-free salt (HNMe)-(CBH) (). The XAS spectrum for reveals a pre-edge feature indicative of covalent Ni-B bonding, which is corroborated by time-dependent density functional theory (TDDFT) calculations and comparative analysis to and inner-shell electron energy loss spectroscopy (ISEELS) collected on the same Ni complex.

Spectroscopic and Theoretical Studies of Ruthenium Complexes with a Noninnocent NS Ligand in Different Redox States.

Herein we report an electronic structure investigation of neutral and oxidized Ru complexes containing a redox noninnocent NS ligand derived from -phenylenediamide (). UV-vis spectroelectrochemistry (SEC) studies were conducted on the square pyramidal complex [Ru()(PPh)] () and the six-coordinate complexes [Ru(μ-BH)()(PPh)] () - which has BH bound in a metal-ligand cooperative (MLC) fashion across Ru and - and [Ru()(PPh)(MeCN)] (). The SEC results yielded spectra assigned to singly and doubly oxidized and , revealing electronic structure changes as a function of oxidation state and in response to the presence and absence of bound MeCN.

A Three-Tiered Faculty Engagement Programme to Support Resident Scholarship.

Background: Residency training represents critical opportunities for scholarly engagement; however, establishing and sustaining effective mentorship for resident research are challenging. In 2007, our internal medicine residency programme developed RAMP (Resident Advising and Mentorship Program) to provide structured mentorship in research and career exploration. A confluence of factors resulted in RAMP stagnating over time, prompting a strategic redesign to meet evolving resident needs.

Atmospheric Evolution of Brown Carbon from Wildfires in North America.

Atmospheric brown carbon (BrC) from wildfires is a key component of light-absorbing carbon that significantly contributes to global radiative forcing, but its atmospheric evolution and lifetime remain poorly understood. In this study, we investigate BrC evolution by synthesizing data from one laboratory campaign and four aircraft campaigns spanning diverse spatial scales across North America. To estimate initial conditions for evaluating plume evolution, we develop a method to parametrize the emission ratios of BrC and other species using commonly measured inert tracers, acetonitrile and hydrogen cyanide.

Mineral Microbiomes Entombed in Great Salt Lake Gypsum: Considerations for Martian Evaporites.

Modern Great Salt Lake, UT, United States, is what remains after the extensive evaporation of Pleistocene Lake Bonneville, which makes this site an appropriate analog to ancient martian lacustrine systems. Today, evaporite minerals surround the lake, including recently precipitated displacive gypsum selenite crystals. Our hypothesis was that hydrated clay solid inclusions within the gypsum would support microbial life with water and nutrients, while the mineral encasement would provide protection from ultraviolet light and temperature fluctuations.

Direct Editing of Cysteine to Electrophilic Alkyl Halides in Peptides.

Functional group conversion is a cornerstone of modern synthetic chemistry. Many strategies routinely employed for small-molecule transformations are unsuitable for modifying biomacromolecules, including peptides. Here, we describe a simple but chemoselective approach that directly converts the nucleophilic cysteine carbon-thiol side chain into an electrophilic carbon-halogen bond under mild conditions, compatible with diverse peptides.

Colony Stimulating Factor-1 (CSF-1) and Interleukin-34 (IL-34) Differentially Alter White Matter and Gray Matter Microglia and Oligodendrocyte Progenitor Cells.

Colony stimulating factor-1 receptor (CSF-1R) signaling is necessary for microglia development and maintenance throughout life. The CSF-1R ligands, CSF-1 and interleukin-34 (IL-34), are indispensable for microglia survival in white matter and gray matter, respectively. While CSF-1 has been studied to a greater extent, the role of IL-34 in microglia function and in the brain overall is much less understood.

A Review of Abrupt Permafrost Thaw: Definitions, Usage, and a Proposed Conceptual Framework.

Purpose Of Review: We review how 'abrupt thaw' has been used in published studies, compare these definitions to abrupt processes in other Earth science disciplines, and provide a definitive framework for how abrupt thaw should be used in the context of permafrost science.

Recent Findings: We address several aspects of permafrost systems necessary for abrupt thaw to occur and propose a framework for classifying permafrost processes as abrupt thaw in the future. Based on a literature review and our collective expertise, we propose that abrupt thaw refers to thaw processes that lead to a substantial persistent environmental change within a few decades.

In-situ formed metal borates enable industrial-level seawater splitting via corrosion-resistant CoFe-Boride nanocatalysts.

Seawater electrolysis offers a sustainable route to green hydrogen production, but chloride-induced corrosion and competing reactions hinder its practical implementation. Here, we report a CoFe-Boride nanocatalyst that in-situ transforms into active borate phases, enabling industrially relevant seawater oxidation with exceptional stability. The catalyst achieves ultralow overpotentials of 394 mV (0.

Krüppel-like Factor 4-Deficient Cells Are Sensitive to Etoposide-Induced DNA Damage.

Krüppel-like factor 4 (KLF4) is a highly conserved zinc-finger transcription factor involved in cellular processes such as development, differentiation, and cell cycle regulation. Previous studies show that mouse embryonic fibroblasts (MEFs) null for exhibit increased genomic instability. While KLF4 is regarded as a tumor suppressor in many human cancers, its role in DNA repair mechanisms remains unknown.

Multi-omics Integrative Analysis for Incomplete Data Using Weighted -Value Adjustment Approaches.

Unlabelled: The advancements in high-throughput technologies provide exciting opportunities to obtain multi-omics data from the same individuals in a biomedical study, and joint analyses of data from multiple sources offer many benefits. However, the occurrence of missing values is an inevitable issue in multi-omics data because measurements such as mRNA gene expression levels often require invasive tissue sampling from patients. Common approaches for addressing missing measurements include analyses based on observations with complete data or multiple imputation methods.

Long-range electron transport in self-assembled fibrils of peptides rich in aromatic residues.

Understanding the mechanism of charge transport in proteins and peptides in physiologically relevant environments has been a long-standing interest, as several physiological processes involve ion and electron transfer in proteins. This has attracted the interest of researchers working on biomolecular electronics. However, the discovery that some bacteria can produce proteinaceous nanowires capable of transporting electrons over distances of up to the centimeter range has opened a new paradigm for the development of synthetic biomimetic proteinaceous nanowires as electronic materials.

Community members' perspectives on sexual orientation and gender identity data collection in health-care settings.

More than 13 million adults in the United States identify as a sexual or gender minority (SGM). This study aimed to describe the barriers and facilitators to SOGI data collection in health-care settings, looking to understand current and past practices with a goal of improving future data collection. With the aid of community-based organizations (CBOs) focused either on cancer or LGBTQ+ issues, 31 individuals were recruited to participate in 4 focus groups.

Function over form: The temporal evolution of affordance-based scene categorization.

Humans can rapidly understand and categorize scenes, yet the specific features and mechanisms that enable categorization remain debated. Here, we investigated whether affordances-the possible actions a scene supports-facilitate scene categorization even when other similarly informative features are present. In Experiment 1, we generated triplets of images that were equally dissimilar on one feature dimension (affordances, materials, surfaces) but similar on the remaining two.

Novel potential pharmacological approaches in treating eating disorders comorbid with substance use disorders.

Eating disorders (EDs), including anorexia nervosa (AN), bulimia nervosa (BN), and binge eating disorder (BED), frequently co-occur with substance use disorders (SUDs), affecting 20-30 % of individuals with either condition. This significant overlap is driven by shared neurobiological mechanisms, such as disruptions in dopamine, opioid, and cannabinoid systems, as well as by psychological traits including impulsivity, anxiety, and stress. While AN is often characterized by restrictive behaviors, BN and BED involve compulsive binge episodes, mirroring addiction patterns observed in SUDs.

Strategies and tactics for subcellular targeting of small molecule zinc sensors.

Zinc(II) ions play manifold roles in human health; dysregulation of zinc homeostasis has been implicated in a number of diseases and pathological conditions. Because zinc(II) is spectroscopically silent, it cannot be detected directly by conventional fluorescence microscopy. As a result, investigators seeking to image zinc(II) in biological systems frequently turn to small-molecule fluorescent sensors that selectively respond to the presence of the ion.

Meaningfully meeting the interoperability mandate: a review of the Assistant Secretary for Technology Policy Real World Testing practices.

Objectives: We analyzed interoperability-related Real World Testing results to identify whether developers are providing meaningful results with the appropriate context to enable stakeholders to understand the Certified Health IT conformance and interoperability when deployed in production environments.

Materials And Methods: This qualitative study analyzed components of the Assistant Secretary for Technology Policy's transitions of care criterion Real World Testing results of 5 inpatient and 5 ambulatory health IT developers with the largest market share.

Results: Developers provided interoperability measures; however, none of the developers' presented results in a meaningful way with the appropriate context to understand product interoperability.

Leaves for high power density hydrovoltaic generators.

Hydrovoltaic generators are a class of electronic devices that can generate electricity from the motion of water molecules through ion-selective microporous channels. Commercial applications of hydrovoltaic devices are limited by their low power density and inability to generate sustained power over a long time. Here, we report the development of leaf-based hydrovoltaic generators that can generate open circuit voltage of up to 1.

Energetics and Oxidative Status: Seasonal Variation in Blood Oxidative Stress Metrics in Four Species of Small Birds from a Cold Winter Climate.

Birds that overwinter in temperate regions must be physiologically flexible to face the demands of living in a thermally fluctuating environment. Much of the previous literature on this topic focuses on whole-animal metabolic rates and corresponding cellular and molecular mechanisms that enable these birds to withstand the demands of changing environmental conditions. Basal and maximal shivering metabolic rates, as well as daily energy expenditure, typically increase in winter for small birds overwintering in cold climates, which might increase the production of reactive oxygen species (ROS) within mitochondria as a natural byproduct of aerobic metabolism.

Blood-Brain Barrier Integrity and Transport of Major Hormones are Unchanged in Mice With Euglycemic Hyperinsulinemia.

High-fat diet (HFD) consumption increases the risk of metabolic syndrome as manifested by insulin resistance, fatty liver, hypertriglyceridemia, and diabetes mellitus type 2. Blood-brain barrier (BBB) disruptions and impaired BBB transport of metabolic hormones, including leptin, insulin, and ghrelin, occur in diabetes mellitus type 2 and contribute to metabolic dysregulation and cognitive impairment. However, it is unclear whether the BBB changes are caused by the HFD, obesity, insulin resistance, elevated glucose or triglyceride levels, or other aspects of the metabolic syndrome.

RDS-04-010: a novel atypical DAT inhibitor that inhibits cocaine taking and seeking and itself has low abuse potential in experimental animals.

Cocaine use disorder (CUD) is a severe public health problem, and currently, there is no FDA-approved medication for its treatment. Atypical dopamine (DA) transporter (DAT) inhibitors display low addictive liability by themselves and may have therapeutic potential for treatment of psychostimulant use disorders. Here, we report that RDS-04-010, a novel atypical DAT inhibitor that binds to an inward-facing conformation of DAT due to its sulfoxide moiety, displayed distinct pharmacological profiles in animal models of addiction from its sulfide analog, RDS-03-094, a DAT inhibitor that binds to a more outward-facing conformation.

Ru and W isotope systematics in ocean island basalts reveals core leakage.

The isotopic composition of lavas associated with mantle plumes has previously been interpreted in the light of core-mantle interaction, suggesting that mantle plumes may transport core material to Earth's surface. However, a definitive fingerprint of Earth's core in the mantle remains unconfirmed. Precious metals, such as ruthenium (Ru), are highly concentrated in the metallic core but extremely depleted in the silicate mantle.