Lincoln Electric (United States)

N-methyl-D-aspartate receptors (NMDARs) mediate excitatory signaling essential for synaptic plasticity and memory. Unlike GluN2-containing NMDARs, GluN3-containing receptors are activated solely by glycine, exhibit profound desensitization and paradoxical potentiation by GluN1-selective antagonists, including CGP-78608 (CGP). Although GluN3 NMDARs regulate synapse pruning, excitotoxicity, and are associated with schizophrenia, autism and stroke, their native stoichiometry and gating mechanism poorly defined. Using single-molecule pulldown analysis, we show that native GluN3A receptors are diheteromeric assemblies. Cryo-EM analysis of GluN1/GluN3A receptors in antagonist-bound, pre-active, active, and desensitized states, augmented by electrophysiology and pharmacology experiments, show how glycine activates the receptor solely via GluN3A-dependent conformational changes, opening the gate with ~2-fold symmetry, and induces a ~4-fold symmetric desensitized state. CGP-bound GluN1 restricts GluN3A rotation, promoting glycine-induced activation by blocking desensitization. These findings illuminate how CGP potentiates GluN3A receptor activity, place the receptor gating mechanism on a solid structural foundation, and define the molecular basis for pharmacological modulation.

Abstract Introduction Inpatient falls are a significant source of morbidity and mortality, particularly in high-risk populations. They are associated with prolonged hospital stays, increased complications, and substantial economic burden. Burn patients may face unique risks due to impaired mobility, systemic stress responses, and restrictions from dressings. Yet, the risk factors and outcomes associated with inpatient falls in burn units remain underexplored. This study evaluates the impact of inpatient falls on adult burn outcomes and identifies predictors of fall risk to guide prevention strategies. Methods This retrospective cohort study included adult patients admitted for burn injury between July 1, 2015, and June 30, 2024. Patients who experienced falls during hospitalization were identified through an internal auditing system (Riskonnect) and matched 1:2 to non-fall controls based on age, sex, total burn surface area (TBSA), and inhalation injury. Data collected included demographics, comorbidities, medication use, Fall Risk Assessment Score (FRAS), physical therapy (PT) and occupational therapy (OT) assessments and fall safety measures. Univariate analyses, receiver operating characteristic (ROC) curve, and stepwise multivariate logistic regression were used to assess associations with fall risk. Statistical significance was defined as p<.05. Results A total of 132 patients were included (45 fallers, 87 non-fallers). Fallers were more likely to use antihypertensives (62.2% vs 39.1%, p=.016) and antiarrhythmics (75.6% vs 52.9%, p=.014) and to require greater mobility assistance at admission (Basic mobility score 16 [11.3–20] vs 20 [14–24], p=.002). More than half (57.8%) experienced a fall prior to their first surgery, with a median time to fall of 9 days. FRAS showed moderate predictive value (AUC = 0.653, p=.009), with a cutoff of 15 yielding 50% sensitivity and 72–74% specificity. OT assessments reflected lower activities of daily living (ADL) independence in fallers (Daily activity total score 16 [12–19] vs 19 [14–22], p=.004). On multivariable analysis, burn surgery requirement (Odds Ratio (OR) = 3.35 [1.12–10.1], p=.031) and FRAS (OR = 1.12 [1.04–1.20], p=.003) were independently associated with fall risk. Conclusions Falls in the burn unit are preceded by identifiable functional deficits and medication patterns. FRAS and early rehabilitation assessments provide valuable risk stratification tools and opportunities for timely intervention. Applicability of Research to Practice These findings highlight the importance of functional risk assessment, interdisciplinary care coordination, and proactive fall prevention protocols tailored to the burn population. Funding for the Study N/A.

Wastewater treatment plants (WWTPs) are integral parts of the infrastructure of metropolitan areas across the world. Their role in treating both stormwater and wastewater helps minimize the impact that humans have on their surrounding environment. Wastewater treatment is an expensive endeavor that aims to balance environmental impact and cost. Current standard methods of evaluating bacterial contamination of wastewater are based on culturing samples for the number of bacterial colonies. Here, we use Oxford Nanopore sequencing as a comprehensive method for surveying the microbial composition of wastewater outflow. 16s rDNA sequencing of final effluent (FE) from the West Point Wastewater Treatment Plant in Seattle, as well as of surrounding coastal environments revealed high levels of Arcobacteraceae, a family of sewage-related bacteria, in the FE and at Discovery Park Beach. We also detected high relative levels of bacteria previously identified to be resistant to antibiotics in the FE, suggesting a need for future studies on the effects of wastewater treatment processes on bacterial viability, as well as possible links to antibiotic-resistant clinical isolates. The release of such bacteria at high levels in the Puget Sound may elevate the risk of horizontal gene transfer, potentially leading to the rise of new antibioticresistant pathogens. Routine monitoring through relatively inexpensive DNA sequencing will allow more comprehensive screening of wastewater and optimization of cost-effective treatment.

β-N-Methylamino-l-alanine (BMAA), a neurotoxic nonproteinogenic amino acid implicated in the development of neurodegenerative diseases, has been broadly associated with cyanobacteria and bioaccumulation through the food web. Early high-level detections, from poorly selective high-performance liquid chromatography-fluorescence detection (HPLC-FLD) methods, have never been repeated using modern, selective tandem mass spectrometry methods. We developed a hydrophilic interaction liquid chromatography-tandem mass spectrometry (HILIC-MS/MS) method for total BMAA analysis, using an improved solid-phase extraction sample cleanup to reduce suppression. We identified oxidative degradation products of BMAA, formed during strong acid hydrolysis, due to residual nitrate in culture media and implemented a dewatering step to resolve this problem. The method was validated using Spirulina powder, environmental, and two cultured cyanobacterial samples, achieving a reporting limit of 0.3 mg/kg in dry cyanobacterial samples. The validated method was then applied to an additional 30 cyanobacteria cultures from Aotearoa New Zealand. BMAA was only detected in one strain, Planktothrix sp. CAWBG-35, at 2.3 mg/kg. These results indicate that BMAA is not produced at the high levels originally reported (e.g., g/kg) in freshwater cyanobacteria and suggest that BMAA production is not widespread among freshwater cyanobacteria from Aotearoa New Zealand. These results have broad implications for future risk-based environmental and public health monitoring.

Most work is done on large existing systems. This chapter will provide strategies for extending conversations into those systems.

User experience is more complicated than it seems, a large part of that complication is because we must balance many competing desires within systems. And when we factor in different user types, this problem is even more complex. Figure 2-1 gives a glimpse of a chat user experience, which contains text, layout, and a dad joke.

Abstract Body size in mammals spans 20 orders of magnitude and is strongly correlated with ecology, making it one of the most important characteristics for a mammal. Body mass must be estimated for fossil mammals because the whole organism is rarely fully preserved. Although the relationships between anatomical characters and body mass have been calculated for many groups of mammals, rodents are less well studied. Previous work had limited sampling of species or used a species average for body size and may not be accurate. Because rodents are the most species rich order of mammals having accurate relationships for the different families of rodents is crucial for understanding the evolution of body size in rodents. I analysed the relationship between body size and three skull characters (skull, molar (M1), and toothrow length) in 11 species of cricetid rodents from Nebraska using reduced major axis regressions. I found a significant positive relationship between all characters and body size. Skull and toothrow length are the best predictors of body size. M1 length is not as good of a predictor because one genus ( Microtus ) has an unusually large M1 length for its body size. Separate regression equations for the Arvicolines and the Sigmodontids provide better predictors for body size using lower M1 length. This work will allow for more accurate predictions of body mass in extinct cricetids.