Social Relationships and Mortality Risk: A Meta-analytic Review

In a meta-analysis, Julianne Holt-Lunstad and colleagues find that individuals' social relationships have as much influence on mortality risk as other well-established risk factors for mortality, such as smoking

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Probing the viability of oxo-coupling pathways in iridium-catalyzed oxygen evolution

[Image: see text] A series of Cp*Ir(III) dimers have been synthesized to elucidate the mechanistic viability of radical oxo-coupling pathways in iridium-catalyzed O(2) evolution. The oxidative stability of the precursors toward nanoparticle formation and their oxygen evolution activity have been investigated and compared to suitable monomeric analogues. We found that precursors bearing monodentate NHC ligands degraded to form nanoparticles (NPs), and accordingly their O(2) evolution rates were not significantly influenced by their nuclearity or distance between the two metals in the dimeric precursors. A doubly chelating bis-pyridine–pyrazolide ligand provided an oxidation-resistant ligand framework that allowed a more meaningful comparison of catalytic performance of dimers with their corresponding monomers. With sodium periodate (NaIO(4)) as the oxidant, the dimers provided significantly lower O(2) evolution rates per [Ir] than the monomer, suggesting a negative interaction instead of cooperativity in the catalytic cycle. Electrochemical analysis of the dimers further substantiates the notion that no radical oxyl-coupling pathways are accessible. We thus conclude that the alternative path, nucleophilic attack of water on high-valent Ir-oxo species, may be the preferred mechanistic pathway of water oxidation with these catalysts, and bimolecular oxo-coupling is not a valid mechanistic alternative as in the related ruthenium chemistry, at least in the present system

Partner outcomes from an uncontrolled trial of Couple HOPES: A guided online couple intervention for posttraumatic stress disorder and relationship enhancement

Posttraumatic stress disorder (PTSD) is associated with significant individual and relationship impairment for people with PTSD and their romantic partners. Conjoint treatments, such as cognitive behavioral conjoint therapy for PTSD (CBCT), are designed to address individual and relationship factors, yet significant barriers impede accessing in-person therapy. Couple HOPES (i.e., Helping Overcome PTSD and Enhance Satisfaction) is a coach-guided, online couple intervention for PTSD based on CBCT that was designed to address these barriers. Previous investigations have found preliminary efficacy of Couple HOPES for improving PTSD symptoms, relationship functioning, and some individual functioning domains for the partner with probable PTSD. However, no study to date has tested individual outcomes for romantic partners, which is needed to fully evaluate the intervention's promise. The current study tested these partner outcomes in a combined, uncontrolled sample of 27 couples. Intent-to-intervene analyses found significant improvements at postintervention in four of eight tested outcomes, including ineffective arguing, g = 0.74; anger, g = 0.32; perceived health, g = 0.67; and quality of life, g = 0.56. Depressive symptoms, generalized anxiety, alcohol misuse, and work functioning did not significantly change, gs = 0.17-0.42. Among participants who completed a 1-month follow-up assessment, generalized anxiety, g = 0.43, and perceived health, g = 0.73, significantly improved over follow-up, whereas anger, g = -0.48, lost gains previously made. Results were largely consistent in the completer sample. These findings show the potential of Couple HOPES to have broad benefits not only for individuals with probable PTSD but also for their romantic partners