Publications by authors named "Shannon Collins"

is a Gram-negative bacterium associated with localized aggressive periodontitis as well as some systemic diseases. The strains of most closely associated with disease produce more of a secreted leukotoxin (LtxA) than isolates from healthy carriers, suggesting a key role for this toxin in disease progression. LtxA is released into the bacterial cytosol in a free form as well as in association with the surface of outer membrane vesicles (OMVs).

View Article and Find Full Text PDF
Article Synopsis
  • The BeeBDC R package provides a solution to the problem of limited and unreliable species occurrence data, particularly for bees, by creating a global dataset from over 18.3 million records.
  • The dataset was meticulously cleaned and standardized, ensuring consistency in species names, country names, and collection dates, while also flagging potential quality issues.
  • The package allows researchers to customize their data filtering and analysis, enhancing the accessibility and reliability of data for future research and conservation efforts.
View Article and Find Full Text PDF

Objectives: Uncovering and addressing disparities in infectious disease outbreaks require a rapid, methodical understanding of local epidemiology. We conducted a seroprevalence study of SARS-CoV-2 infection in Holyoke, Massachusetts, a majority Hispanic city with high levels of socio-economic disadvantage to estimate seroprevalence and identify disparities in SARS-CoV-2 infection.

Methods: We invited 2000 randomly sampled households between 11/5/2020 and 12/31/2020 to complete questionnaires and provide dried blood spots for SARS-CoV-2 antibody testing.

View Article and Find Full Text PDF

We previously identified the mechanistic target of rapamycin complex 2 (mTORC2) as an effector of Ras for the control of directed cell migration in . Recently, the Ras-mediated regulation of mTORC2 was found to be conserved in mammalian cells, and mTORC2 was shown to be an effector of oncogenic Ras. Interestingly, mTORC2 has been linked to cancer cell migration, and particularly in breast cancer.

View Article and Find Full Text PDF

Point-of-care antigen-detecting rapid diagnostic tests (RDTs) to detect Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) represent a scalable tool for surveillance of active SARS-CoV-2 infections in the population. Data on the performance of these tests in real-world community settings are paramount to guide their implementation to combat the COVID-19 pandemic. We evaluated the performance characteristics of the CareStart COVID-19 Antigen test (CareStart) in a community testing site in Holyoke, Massachusetts.

View Article and Find Full Text PDF

The development of high quality, non-toxic (, heavy-metal-free), and functional quantum dots (QDs) 'green' and scalable synthesis routes is critical for realizing truly sustainable QD-based solutions to diverse technological challenges. Herein, we demonstrate the low-temperature all-aqueous-phase synthesis of silver indium sulfide/zinc (AIS/Zn) QDs with a process initiated by the biomineralization of highly crystalline indium sulfide nanocrystals, and followed by the sequential staging of Ag cation exchange and Zn addition directly within the biomineralization media without any intermediate product purification. Therein, we exploit solution phase cation concentration, the duration of incubation in the presence of InS precursor nanocrystals, and the subsequent addition of Zn as facile handles under biomineralization conditions for controlling QD composition, tuning optical properties, and improving the photoluminescence quantum yield of the AIS/Zn product.

View Article and Find Full Text PDF

Analytical characterization of small biological particles, such as extracellular vesicles (EVs), is complicated by their extreme heterogeneity in size, lipid, membrane protein, and cargo composition. Analysis of individual particles is essential for illuminating particle property distributions that are obscured by ensemble measurements. To enable high-throughput analysis of individual particles, liftoff nanocontact printing (LNCP) is used to define hexagonal antibody and toxin arrays that have a 425 nm dot size, on average, and 700 nm periodicity.

View Article and Find Full Text PDF

Bacterial outer membrane vesicles (OMVs) are nanometer-scale, spherical vehicles released by Gram-negative bacteria into their surroundings throughout growth. These OMVs have been demonstrated to play key roles in pathogenesis by delivering certain biomolecules to host cells, including toxins and other virulence factors. In addition, this biomolecular delivery function enables OMVs to facilitate intra-bacterial communication processes, such as quorum sensing and horizontal gene transfer.

View Article and Find Full Text PDF

The cell wall of Gram-negative bacteria consists of an inner (cytoplasmic) and outer membrane (OM), separated by a thin peptidoglycan layer. Throughout growth, the outer membrane can bleb to form spherical outer membrane vesicles (OMVs). These OMVs are involved in numerous cellular functions including cargo delivery to host cells and communication with bacterial cells.

View Article and Find Full Text PDF

Introduction: Malposition of THA implants can lead to many complications, some of which may necessitate reoperation. Thus, proper implant placement is critical for optimizing patient outcomes. In addition, intraoperative visual estimation of stem position has been shown to be unreliable.

View Article and Find Full Text PDF

The Ras oncogene is notoriously difficult to target with specific therapeutics. Consequently, there is interest to better understand the Ras signaling pathways to identify potential targetable effectors. Recently, the mechanistic target of rapamycin complex 2 (mTORC2) was identified as an evolutionarily conserved Ras effector.

View Article and Find Full Text PDF

Fermentation-based chemical production strategies provide a feasible route for the rapid, safe, and sustainable production of a wide variety of important chemical products, ranging from fuels to pharmaceuticals. These strategies have yet to find wide industrial utilization due to their inability to economically compete with traditional extraction and chemical production methods. Here, we engineer for the first time the complex microbial biosynthesis of an anthocyanin plant natural product, starting from sugar.

View Article and Find Full Text PDF

Methanol is an attractive substrate for biological production of chemicals and fuels. Engineering methylotrophic Escherichia coli as a platform organism for converting methanol to metabolites is desirable. Prior efforts to engineer methylotrophic E.

View Article and Find Full Text PDF

Robust gene circuit construction requires use of promoters exhibiting low crosstalk. Orthogonal promoters have been engineered utilizing an assortment of natural and synthetic transcription factors, but design of large orthogonal promoter-repressor sets is complicated, labor-intensive, and often results in unanticipated crosstalk. The specificity and ease of targeting the RNA-guided DNA-binding protein dCas9 to any 20 bp user-defined DNA sequence makes it a promising candidate for orthogonal promoter regulation.

View Article and Find Full Text PDF

Metabolic engineering and synthetic biology have enabled the use of microbial production platforms for the renewable production of many high-value natural products. Titers and yields, however, are often too low to result in commercially viable processes. Microbial co-cultures have the ability to distribute metabolic burden and allow for modular specific optimization in a way that is not possible through traditional monoculture fermentation methods.

View Article and Find Full Text PDF

Flavonoids are a growing class of bioactive natural products with distinct and interesting bioactivity both in vitro and in vivo. The extraction of flavonoids from plant sources is limited by their low natural abundance and commonly results in a mixture of products that are difficult to separate. However, due to recent advances, the microbial production of plant natural products has developed as a promising alternative for flavonoid production.

View Article and Find Full Text PDF

Objective: The authors sought to evaluate 2 approaches with varying time and complexity in engaging adolescents with an Internet-based preventive intervention for depression in primary care. The authors conducted a randomized controlled trial comparing primary care physician motivational interview (MI, 5-10 minutes) + Internet program versus brief advice (BA, 1-2 minutes) + Internet program.

Setting: Adolescent primary care patients in the United States, aged 14 to 21 years.

View Article and Find Full Text PDF

Background: Adolescent depression is both a major public health and clinical problem, yet primary care physicians have limited intervention options. We developed two versions of an Internet-based behavioral intervention to prevent the onset of major depression and compared them in a randomized clinical trial in 13 US primary care practices.

Methods: We enrolled 84 adolescents at risk for developing major depression and randomly assigned them to two groups: brief advice (BA; 1-2 minutes) + Internet program versus motivational interview (MI; 5-15 minutes) + Internet program.

View Article and Find Full Text PDF

Purpose: This article reports on the findings of a study whose purpose was to explore the experiences of caregivers of gay and lesbian seniors living in the community and to identify issues that emerged from an exploration of access to and equity in health care services for these populations.

Design And Methods: The study used a qualitative methodology based upon principles of grounded theory in which open-ended interviews were undertaken with 17 caregivers living in three different cities across Canada.

Results: Findings indicated several critical themes, including the impact of felt and anticipated discrimination, complex processes of coming out, the role of caregivers, self-identification as a caregiver, and support.

View Article and Find Full Text PDF

Objectives: Pulse oximetry is widely used in the NICU, but clinicians often distrust the displayed values during patient motion, i.e., questionable oxygen saturation (SpO(2)) and pulse rate (PR) values.

View Article and Find Full Text PDF