Reproducibility and implementation of a rapid, community-based COVID-19 "test and respond" model in low-income, majority-Latino communities in Northern California.

Objective: To evaluate implementation of a community-engaged approach to scale up COVID-19 mass testing in low-income, majority-Latino communities.

Methods: In January 2021, we formed a community-academic "Latino COVID-19 Collaborative" with residents, leaders, and community-based organizations (CBOs) from majority-Latinx, low-income communities in three California counties (Marin/Merced/San Francisco). The collaborative met monthly to discuss barriers/facilitators for COVID-19 testing, and plan mass testing events informed by San Francisco's Unidos en Salud "test and respond" model, offering community-based COVID-19 testing and post-test support in two US-census tracts: Canal (Marin) and Planada (Merced).

Comparison of SARS-CoV-2 Reverse Transcriptase Polymerase Chain Reaction and BinaxNOW Rapid Antigen Tests at a Community Site During an Omicron Surge : A Cross-Sectional Study.

Background: SARS-CoV-2 rapid antigen tests are an important public health tool.

Objective: To evaluate field performance of the BinaxNOW rapid antigen test (Abbott) compared with reverse transcriptase polymerase chain reaction (RT-PCR) for detecting infection with the Omicron variant of SARS-CoV-2.

Design: Cross-sectional surveillance study.

The COVID-19 Symptom to Isolation Cascade in a Latinx Community: A Call to Action.

Background: Rapid coronavirus disease 2019 (COVID-19) diagnosis and isolation of infectious persons are critical to stopping forward transmission, and the care cascade framework can identify gaps in the COVID-19 response.

Methods: We described a COVID-19 symptom to isolation cascade and barriers among symptomatic persons who tested polymerase chain reaction positive for severe acute respiratory disease coronavirus 2 (SARS-CoV-2) at a low-barrier testing site serving a low-income Latinx community in San Francisco. Steps in the cascade are defined as days from symptom onset to test, test to result, and result to counseling on self-isolation.

Community Transmission of Severe Acute Respiratory Syndrome Coronavirus 2 Disproportionately Affects the Latinx Population During Shelter-in-Place in San Francisco.

Background: There is an urgent need to understand the dynamics and risk factors driving ongoing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission during shelter-in-place mandates.

Methods: We offered SARS-CoV-2 reverse-transcription polymerase chain reaction (PCR) and antibody (Abbott ARCHITECT IgG) testing, regardless of symptoms, to all residents (aged ≥4 years) and workers in a San Francisco census tract (population: 5174) at outdoor, community-mobilized events over 4 days. We estimated SARS-CoV-2 point prevalence (PCR positive) and cumulative incidence (antibody or PCR positive) in the census tract and evaluated risk factors for recent (PCR positive/antibody negative) vs prior infection (antibody positive/PCR negative).

Msn2 coordinates a stoichiometric gene expression program.

Background: Many cellular processes operate in an "analog" regime in which the magnitude of the response is precisely tailored to the intensity of the stimulus. In order to maintain the coherence of such responses, the cell must provide for proportional expression of multiple target genes across a wide dynamic range of induction states. Our understanding of the strategies used to achieve graded gene regulation is limited.

Whole cell imaging reveals novel modular features of the exomembrane system of the malaria parasite, Plasmodium falciparum.

During its intra-erythrocytic development Plasmodium falciparum establishes a membrane network beyond its own limiting membrane in the cytoplasm of its host. These membrane structures play an important role in the trafficking of virulence proteins to the erythrocyte surface, however their ultrastructure is only partly defined and there is on-going debate regarding their origin, organisation and connectivity. We have used two whole cell imaging modalities to explore the topography of parasitised erythrocytes.

Dynamics and design principles of a basic regulatory architecture controlling metabolic pathways.

The dynamic features of a genetic network's response to environmental fluctuations represent essential functional specifications and thus may constrain the possible choices of network architecture and kinetic parameters. To explore the connection between dynamics and network design, we have analyzed a general regulatory architecture that is commonly found in many metabolic pathways. Such architecture is characterized by a dual control mechanism, with end product feedback inhibition and transcriptional regulation mediated by an intermediate metabolite.

Genome-scale approaches for discovering novel nonconventional splicing substrates of the Ire1 nuclease.

Background: The unfolded protein response (UPR) allows intracellular feedback regulation that adjusts the protein-folding capacity of the endoplasmic reticulum (ER) according to need. The signal from the ER lumen is transmitted by the ER-transmembrane kinase Ire1, which upon activation displays a site-specific endoribonuclease activity. Endonucleolytic cleavage of the intron from the HAC1 mRNA (encoding a UPR-specific transcription factor) is the first step in a nonconventional mRNA splicing pathway; the released exons are then joined by tRNA ligase.