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Abstract The “secondhit” pathway is responsible for biallelic inactivation of many tumor suppressors, where a pathogenic germline allele is joined by somatic mutation of the remaining functional allele. The mechanisms are unresolved, but the human PKD1 tumor suppressor is a good experimental model for identifying the molecular determinants. Inactivation of PKD1 results in autosomal dominant polycystic kidney disease, a very common disorder characterized by the accumulation of fluid-filled cysts and end-stage renal disease. Since human PKD1 follows second hit and mouse Pkd1 heterozygotes do not, we reasoned that there is likely a molecular difference that explains the elevated mutagenesis of the human gene. Here we demonstrate that guanine quadruplex DNA structures are abundant throughout human, but not mouse, PKD1 where they activate the DNA damage response. Our results suggest that guanine quadruplex DNAs provoke DNA breaks in PKD1, providing a potential mechanism for cystogenesis in autosomal dominant polycystic kidney disease specifically and for the inactivation of guanine quadruplex-rich tumor suppressors generally.

Abstract Background The application of ‘-omics’ technologies to study bacterial vaginosis (BV) has uncovered vast differences in composition and scale between the vaginal microbiomes of healthy and BV patients. Compared to amplicon sequencing and shotgun metagenomic approaches focusing on a single or few species, investigating the transcriptome of the vaginal microbiome at a system-wide level can provide insight into the functions which are actively expressed and differential between states of health and disease. Results We conducted a meta-analysis of vaginal metatranscriptomes from three studies, split into exploratory (n = 42) and validation (n = 297) datasets, accounting for the compositional nature of sequencing data and differences in scale between healthy and BV microbiomes. Conducting differential expression analyses on the exploratory dataset, we identified a multitude of strategies employed by microbes associated with states of health and BV to evade host cationic antimicrobial peptides (CAMPs); putative mechanisms used by BV-associated species to resist and counteract the low vaginal pH; and potential approaches to disrupt vaginal epithelial integrity so as to establish sites for adherence and biofilm formation. Moreover, we identified several distinct functional subgroups within the BV population, distinguished by genes involved in motility, chemotaxis, biofilm formation and co-factor biosynthesis. After defining molecular states of health and BV in the validation dataset using KEGG orthology terms rather than community state types, differential expression analysis confirmed earlier observations regarding CAMP resistance and compromising epithelial barrier integrity in healthy and BV microbiomes and also supported the existence of motile vs. non-motile subgroups in the BV population. These findings were independent of the enzyme classification system used (KEGG or EggNOG). Conclusions Our findings highlight a need to focus on functional rather than taxonomic differences when considering the role of microbiomes in disease and identify pathways for further research as potential BV treatment targets. Video Abstract

Abstract The tantalum carbides, TaC x , have been repeatedly shown to harden dramatically with some loss of carbon content, then soften with further decarburization. First observed in 1963, this anomalous hardness behavior has been reproduced for decades without satisfactory explanation. Prior attempts to characterize this phenomenon using elastic stiffnesses have failed to reproduce the anomalous hardness behavior. In this work, we demonstrate a change in slip system preference from {111}B1 to {110}B1 in TaC x as x decreases, while no such transition is observed in TiC x . We find this to be the primary mechanism of the anomalous hardness, arising from reduced energetic favorability of dissociation of dislocations on {111}B1 into Shockley partials at lower carbon contents. We also present experimental hardness measurements for bulk and thin-film TaC x at different carbon contents. An anomalous hardness peak is observed in the bulk samples, but not in the thin films, due to loss of dislocation plasticity in the nanocrystalline films.

ABSTRACT: Barley grain sources with variable kernel sizes makes adequate and consistent processing of kernels challenging. This study evaluated how the severity of processing for reconstituted high-moisture (65% on DM basis) barley (RHB) affects ensiling characteristics and in vitro ruminal fermentation. Three independent sources of light (670 g/500 mL) barley were blended to create 4 sources of variable kernel sized barley (646 g/500 mL). Reconstituted high-moisture barley rolled using a 1.40-mm gap width for finely processed RHB (RHBF), a 1.86-mm gap width for medium processed RHB (RHBM), or a 2.31-mm gap width for coarsely processed RHB (RHBC) was ensiled for 1 or 5 mo with dry rolled barley (DRB; roller gap width 1.86 mm) used as a control. The 1-mo RHB and the DRB were further evaluated using the rumen in vitro simulation technique (RUSITEC) to investigate the effects of severity of processing for RHB on ruminal fermentation, and gas, methane, and microbial protein production. Using a randomized complete block design (n = 4), 16 fermenters from 2 RUSITEC apparatuses were used to assess the 4 sources and 4 processing treatments. The addition of water increased kernel width before rolling and resulted in increased kernel length, width, and thickness for RHB relative to DRB. Increasing processing severity for RHB linearly increased kernel width. The percentage of fine particles (

This work presents a study of a low-power, solid-state additive manufacturing process to simultaneously mix and build a metal matrix composite. Specifically, an Al 6061 powder was blended with 11 wt% silica (SiO2) after which the powders were solid-state consolidated through additive friction stir deposition (AFSD). The inclusion of the SiO2 resulted in an average hardness of 70 ± 1 HV as compared to a control (no SiO2) of 52 ± 1 Hv. However, for the SiO2 composite, the hardness varied in both the radial build and vertical build directions, with the highest hardness found in the centerline of the deposit. This inhomogeneity has been contributed to differences in how the SiO2 particulates evolve during the stirring and mixing processes of AFSD. Furthermore, this variation in particulate evolution was found to be a useful marker in understanding the microstructure evolution through AFSD.

While significant progress has been made to characterize life history patterns, movement ecology, and regional estimates of abundance of white sharks (Carcharodon carcharias) in the Western North Atlantic (WNA), patterns of spatial distribution remain relatively unknown in the northern Gulf of Maine. In this study, we utilize data collected from multiple acoustic telemetry projects from 2012-2023 to assess the spatiotemporal distribution of white sharks along sections of the Maine coastline and regional offshore waters. Acoustic receivers were deployed each year from 2012-2019 (mean number of receivers ± SD: 11 ± 4), and effort increased following the first-ever white shark related fatality in Maine in 2020 (2020-2023: 40 ± 15). In total, 107 white sharks tagged by researchers in the WNA were detected, with the majority (n = 90) detected in shallow (

Introduction Many chemotherapy agents used to treat advanced cancer are inherently mucotoxic, causing breakdown of the gastrointestinal mucosa (gastrointestinal mucositis (GI-M)) and lead to a constellation of secondary complications including diarrhoea, malnutrition, anorexia, pain, fatigue and sleep disturbances. These symptoms are usually managed individually, leading to polypharmacy and its associated risks. The endocannabinoid system regulates numerous biological and behavioural processes associated with chemotherapy side effects, suggesting its modulation could control these symptoms. Therefore, the CANnabinoids in CANcer (CANCAN) therapy trial is a phase II, randomised, double-blind, placebo-controlled trial that aims to determine the efficacy of medicinal cannabis in minimising GI-M and its associated symptom burden.Methods and analysis The CANCAN trial is being conducted at four Australian sites: the Royal Adelaide Hospital, the Queen Elizabeth Hospital, Flinders Medical Centre and the Lyell McEwin Hospital. Adults (n=176) diagnosed with a solid tumour or a haematological cancer scheduled to receive mucotoxic chemotherapy will be eligible. Participants will be randomised 1:1 to receive either the investigational product (IP) or placebo, both delivered as sublingual wafers. The active IP contains cannabidiol (300 mg/day) and Δ9-tetrahydrocannabinol (5–20 mg/day, titrated by the participant). The primary outcome is GI-M burden, determined by the Mucositis Daily Questionnaire. Secondary and tertiary outcomes include overall symptom burden (Edmonton Symptom Assessment Scale), anorexia (Average Functional Assessment of Anorexia/Cachexia Therapy), depression/anxiety (Hospital Anxiety and Depression Scale), financial toxicity (Functional Assessment of Chronic Illness Therapy COmprehensive Score for financial Toxicity), quality of life (European Organisation for Research and Treatment of Cancer Core Quality of Life Questionnaire), incidence of chemotherapy dose reductions/modifications, cumulative dose of chemotherapy administered, incidence/length of hospitalisation, the use of supportive care, and the cost-benefit of the IP. The CANCAN trial prioritises patient experiences by focusing on patient-reported outcome measures and administering medicinal cannabis during active treatment to prevent symptoms that occur secondary to mucositis.Ethics and dissemination The protocol has been approved by Central Adelaide Local Health Network Human Research Ethics Committee (2022HRE00037). All participants will be required to provide written or digitally authorised informed consent. Trial results will be disseminated in peer-reviewed journals, and at scientific conferences.Trial registration number ACTRN12622000419763.

Abstract Background Physician burnout is rising, especially among academic physicians facing pressures to increase their clinical workload, lead administrative tasks and committees, and be active in research. There is a concern this could have downstream effects on learners’ experiences and academic physician’s ability to teach learners on the team. Methods A 29-question RedCap survey was electronically distributed to 54 attending physicians within an academic learning health system who oversaw the General Medicine inpatient teaching services during the 2022–2023 academic year. The aims were to assess this cohort of attending physicians’ experiences, attitudes, and perceptions on their ability to effectively teach learners on the team, feeling valued, contributors to work-life balance and symptoms of burnout, Fisher’s Exact Tests were used for data analysis. Results Response rate was 56%. Attendings splitting time 50% inpatient / 50% outpatient felt that team size and type of admissions model affected their ability to effectively teach learners (p = 0.022 and p = 0.049). Attendings with protected administrative time felt that non-patient care obligations affected their ability to effectively teach the learners (p = 0.019). Male attendings and attendings with ≤ 5 years of General Medicine inpatient teaching experience felt less valued by residency leadership (p = 0.019 and p = 0.026). 80% of attendings experienced emotional exhaustion, and those with > 10 weeks on a General Medicine inpatient teaching service were more likely to experience emotional exhaustion (p = 0.041). Attendings with > 10 weeks on a General Medicine inpatient teaching service and those who were a primary caregiver were more likely to experience depersonalization (p = 0.012 and p = 0.031). 57% of attendings had reduced personal achievement. Conclusions Institutions should seek an individual and organizational approach to professional fulfillment. Special attention to these certain groups is warranted to understand how they can be better supported. Further research, such as with focus groups, is needed to address these challenges.

ABSTRACT During its cell cycle, the bacterium Caulobacter crescentus switches from a motile, free-living state, to a sessile surface-attached cell. During this coordinated process, cells undergo irreversible morphological changes, such as shedding of their polar flagellum and synthesis of an adhesive holdfast at the same pole. In this work, we used genetic screens to identify genes involved in the regulation of the transition from the motile to the sessile lifestyle. We identified a predicted hybrid histidine kinase that inhibits biofilm formation and promotes the motile lifestyle: HmrA (holdfast and motility regulator A). Genetic screens and genomic localization led to the identification of additional genes that form a putative phosphorelay pathway with HmrA. We postulate that the Hmr pathway acts as a rheostat to control the proportion of cells harboring a flagellum or a holdfast in the population. Further genetic analysis suggests that the Hmr pathway impacts c-di-GMP synthesis through the diguanylate cyclase DgcB pathway. Our results also indicate that the Hmr pathway is involved in the regulation of motile to sessile lifestyle transition as a function of various environmental factors: biofilm formation is repressed when excess copper is present and derepressed under non-optimal temperatures. Finally, we provide evidence that the Hmr pathway regulates motility and adhesion without modulating the transcription of the holdfast synthesis regulator HfiA.IMPORTANCEComplex communities attached to a surface, or biofilms, represent the major lifestyle of bacteria in the environment. Such a sessile state enables the inhabitants to be more resistant to adverse environmental conditions. Thus, having a deeper understanding of the underlying mechanisms that regulate the transition between the motile and the sessile states could help design strategies to improve biofilms when they are beneficial or impede them when they are detrimental. For Caulobacter crescentus motile cells, the transition to the sessile lifestyle is irreversible, and this decision is regulated at several levels. In this work, we describe a putative phosphorelay that promotes the motile lifestyle and inhibits biofilm formation, providing new insights into the control of adhesin production that leads to the formation of biofilms.

Mid-infrared microscopy is an important tool for biological analyses, allowing a direct probe of molecular bonds in their low energy landscape. In addition to the label-free extraction of spectroscopic information, the application of broadband sources can provide a third dimension of chemical specificity. However, to enable widespread deployment, mid-infrared microscopy platforms need to be compact and robust while offering high speed, broad bandwidth, and high signal-to-noise ratio. In this study, we experimentally showcase the integration of a broadband, high-repetition-rate dual-comb spectrometer (DCS) in the mid-infrared range with a scanning microscope. We employ a set of 1-GHz mid-infrared frequency combs, demonstrating their capability for high-speed and broadband hyperspectral imaging of polymers and ovarian tissue. The system covers 1000 cm−1 at νc = 2941 cm−1 with 12.86 kHz spectra acquisition rate and 5 µm spatial resolution. Taken together, our experiments and analysis elucidate the trade-off between bandwidth and speed in DCS as it relates to microscopy. This provides a roadmap for the future advancement and application of high-repetition-rate DCS hyperspectral imaging.

The Ga+ focused Ion Beam (FIB) or Xe+ Plasma FIB (PFIB) procedure has enabled the ability to make specimens where mechanical tests in the microscale regime can be achieved with high precision. Nevertheless, milling times can be long and shape optimization can be arduous collectively limiting the ability to readily make a sufficient number of test samples. In this work, we present a sample preparation technique for microscale cantilever fabrication which streamlines the milling procedures by using combined electropolishing and FIB milling. Specifically, the procedure mitigates extensive undercutting requirements which reduces the fabrication time for the microcantilever to more than half that time as compared to direct milling methods from making similar geometries directly from the bulk material. This process is discussed along with specific aspects related to the sample alignment of the cantilever to specific fracture planes for single crystals. In addition, we comment on the applicability of this method to polycrystalline samples.