Local disorder is associated with enhanced catalysis in an engineered photoswitch.

The LOV2 domain is commonly harnessed as a source of light-based regulation in engineered optogenetic switches. In prior work, we used LOV2 to create a light-regulated Dihydrofolate Reductase (DHFR) enzyme and showed that structurally disperse mutations in DHFR were able to tune the allosteric response to light. However, it remained unclear how light allosterically activates DHFR, and how disperse mutations modulate the allosteric effect.

Irreversibility in bacterial regulatory networks.

Irreversibility, in which a transient perturbation leaves a system in a new state, is an emergent property in systems of interacting entities. This property has well-established implications in statistical physics but remains underexplored in biological networks, especially for bacteria and other prokaryotes whose regulation of gene expression occurs predominantly at the transcriptional level. Focusing on the reconstructed regulatory network of , we examine network responses to transient single-gene perturbations.

The genetic landscape of a metabolic interaction.

While much prior work has explored the constraints on protein sequence and evolution induced by physical protein-protein interactions, the sequence-level constraints emerging from non-binding functional interactions in metabolism remain unclear. To quantify how variation in the activity of one enzyme constrains the biochemical parameters and sequence of another, we focus on dihydrofolate reductase (DHFR) and thymidylate synthase (TYMS), a pair of enzymes catalyzing consecutive reactions in folate metabolism. We use deep mutational scanning to quantify the growth rate effect of 2696 DHFR single mutations in 3 TYMS backgrounds under conditions selected to emphasize biochemical epistasis.

A continuous epistasis model for predicting growth rate given combinatorial variation in gene expression and environment.

Quantifying and predicting growth rate phenotype given variation in gene expression and environment is complicated by epistatic interactions and the vast combinatorial space of possible perturbations. We developed an approach for mapping expression-growth rate landscapes that integrates sparsely sampled experimental measurements with an interpretable machine learning model. We used mismatch CRISPRi across pairs and triples of genes to create over 8,000 titrated changes in E.

Engineering Proteins Using Statistical Models of Coevolutionary Sequence Information.

Homologous protein sequences are wonderfully diverse, indicating many possible evolutionary "solutions" to the encoding of function. Consequently, one can construct statistical models of protein sequence by analyzing amino acid frequency across a large multiple sequence alignment. A central premise is that covariance between amino acid positions reflects coevolution due to a shared functional or biophysical constraint.

The Continued Impact of the COVID-19 Pandemic on Pediatric Obesity: A Commentary on the Return to a Healthy New "Normal".

Two years into this pandemic, mental health symptoms are more prevalent in children and adolescents, routine wellness visits have decreased, individuals and families are experiencing increased stress, and food and nutrition insecurity are on the rise. Pediatric overweight and obesity are yet another health condition that has been impacted by the pandemic. The current commentary aims to (a) summarize a variety of factors contributing to worsening obesity and healthy lifestyle choices in youth throughout the pandemic and to (b) provide recommendations for healthcare providers on navigating this challenge.

Situational factors shape moral judgements in the trolley dilemma in Eastern, Southern and Western countries in a culturally diverse sample.

The study of moral judgements often centres on moral dilemmas in which options consistent with deontological perspectives (that is, emphasizing rules, individual rights and duties) are in conflict with options consistent with utilitarian judgements (that is, following the greater good based on consequences). Greene et al. (2009) showed that psychological and situational factors (for example, the intent of the agent or the presence of physical contact between the agent and the victim) can play an important role in moral dilemma judgements (for example, the trolley problem).

Structurally distributed surface sites tune allosteric regulation.

Our ability to rationally optimize allosteric regulation is limited by incomplete knowledge of the mutations that tune allostery. Are these mutations few or abundant, structurally localized or distributed? To examine this, we conducted saturation mutagenesis of a synthetic allosteric switch in which Dihydrofolate reductase (DHFR) is regulated by a blue-light sensitive LOV2 domain. Using a high-throughput assay wherein DHFR catalytic activity is coupled to growth, we assessed the impact of 1548 viable DHFR single mutations on allostery.

Accelerating Biological Insight for Understudied Genes.

The rapid expansion of genome sequence data is increasing the discovery of protein-coding genes across all domains of life. Annotating these genes with reliable functional information is necessary to understand evolution, to define the full biochemical space accessed by nature, and to identify target genes for biotechnology improvements. The majority of proteins are annotated based on sequence conservation with no specific biological, biochemical, genetic, or cellular function identified.

Historic Firsts: Aeromedical Evacuation and the Transportation Isolation System.

This short communication highlights the US Air Force's recent success with having their aeromedical evacuation crews use the Transportation Isolation System for the first time operationally to transport patients positive for coronavirus disease 2019.

A simplified strategy for titrating gene expression reveals new relationships between genotype, environment, and bacterial growth.

A lack of high-throughput techniques for making titrated, gene-specific changes in expression limits our understanding of the relationship between gene expression and cell phenotype. Here, we present a generalizable approach for quantifying growth rate as a function of titrated changes in gene expression level. The approach works by performing CRISPRi with a series of mutated single guide RNAs (sgRNAs) that modulate gene expression.

Weight outcomes in children with developmental disabilities from a multidisciplinary clinic.

Background: Children with developmental disabilities experience disparately high rates of obesity yet there are few reports detailing clinical outcomes for this population.

Aim: To describe outcomes of obesity treatment for children with developmental disabilities and a comparison group of children without developmental disabilities.

Methods And Procedures: We examined weight outcomes of children with and without developmental disabilities seen in a family-centered, multidisciplinary treatment center over a ten-year period.

Silicosis.

Occupational exposures to dust with elevated levels of respirable crystalline silica in artificial stone increase workers' risk for silicosis.

Altered expression of a quality control protease in reshapes the in vivo mutational landscape of a model enzyme.

Protein mutational landscapes are shaped by the cellular environment, but key factors and their quantitative effects are often unknown. Here we show that Lon, a quality control protease naturally absent in common expression strains, drastically reshapes the mutational landscape of the metabolic enzyme dihydrofolate reductase (DHFR). Selection under conditions that resolve highly active mutants reveals that 23.

Assessing Burnout and Associated Risk Factors in Medical Students.

Purpose: Our study aims to build on existing literature by assessing factors that may be associated with an increased risk of burnout amongst medical students, particularly students of color.

Methods: Our cross-sectional survey included the Copenhagen Burnout Inventory (CBI) and additional de novo questions. Surveys were administered electronically in June 2017 using a convenience sampling method.

Timely Delivery of Discharge Medications to Patients' Bedsides: A Patient-centered Quality Improvement Project.

Introduction: Patients who are unable to fill prescriptions after discharge are at risk of hospital readmission. Ensuring that patients have prescriptions in hand at the time of discharge is a critical component of a safe and effective discharge process. Using a "Meds to Beds" program, we aimed to increase the percentage of patients discharged from Holtz Children's Hospital with medications in hand from 49% to 80%, reduce turnaround time (TAT) from electronic prescription signature to bedside delivery from 4.

Psychopathology and Adolescent Bariatric Surgery: A Topical Review to Support Psychologists in Assessment and Treatment Considerations.

The rising rates of severe obesity among adolescents in the United States indicate a dire need for more intensive weight management strategies. While current evidence suggests that bariatric surgery is a safe and efficacious intervention for adolescents, the linkages with psychopathology before and after surgery are not well understood. Psychologists are an integral part of the interdisciplinary surgery team and play an important role in preparing youth for bariatric surgery as well as supporting adolescents post-surgery.

Strategies for Engineering and Rewiring Kinase Regulation.

Eukaryotic protein kinases (EPKs) catalyze the transfer of a phosphate group onto another protein in response to appropriate regulatory cues. In doing so, they provide a primary means for cellular information transfer. Consequently, EPKs play crucial roles in cell differentiation and cell-cycle progression, and kinase dysregulation is associated with numerous disease phenotypes including cancer.

Trends in gabapentin and baclofen exposures reported to U.S. poison centers.

Prescriptions for nonopioid pharmacological therapies such as gabapentin and baclofen have been increasing. While gabapentin and baclofen are less likely than opioids to result in fatal overdose, they are each associated with dependence, misuse and adverse effects. The objective of this study is to evaluate and describe trends in adult exposures to gabapentin and baclofen reported to U.

High-Order Epistasis in Catalytic Power of Dihydrofolate Reductase Gives Rise to a Rugged Fitness Landscape in the Presence of Trimethoprim Selection.

Evolutionary fitness landscapes of several antibiotic target proteins have been comprehensively mapped showing strong high-order epistasis between mutations, but understanding these effects at the biochemical and structural levels remained open. Here, we carried out an extensive experimental and computational study to quantitatively understand the evolutionary dynamics of Escherichia coli dihydrofolate reductase (DHFR) enzyme in the presence of trimethoprim-induced selection. To facilitate this, we developed a new in vitro assay for rapidly characterizing DHFR steady-state kinetics.