Staphylococcus aureus is an opportunistic pathogen that colonizes the skin and mucosal surfaces of mammals. Persistent staphylococcal infections often involve surface-associated communities called ...biofilms. Here we report the discovery of a novel extracellular fibril structure that promotes S. aureus biofilm integrity. Biochemical and genetic analysis has revealed that these fibers have amyloid-like properties and consist of small peptides called phenol soluble modulins (PSMs). Mutants unable to produce PSMs were susceptible to biofilm disassembly by matrix degrading enzymes and mechanical stress. Previous work has associated PSMs with biofilm disassembly, and we present data showing that soluble PSM peptides disperse biofilms while polymerized peptides do not. This work suggests the PSMs' aggregation into amyloid fibers modulates their biological activity and role in biofilms.
Development of improved approaches for HIV-1 prevention will likely be required for a durable end to the global AIDS pandemic. Recent advances in preclinical studies and early phase clinical trials ...offer renewed promise for immunologic strategies for blocking acquisition of HIV-1 infection. Clinical trials are currently underway to evaluate the efficacy of two vaccine candidates and a broadly neutralizing antibody (bNAb) to prevent HIV-1 infection in humans. However, the vast diversity of HIV-1 is a major challenge for both active and passive immunization. Here we review current immunologic strategies for HIV-1 prevention, with a focus on current and next-generation vaccines and bNAbs.
This paper analyzes match attendance for the National Women's Soccer League over its first seven seasons. Findings include large attendance boosts for matches played after the 2015 and 2019 Women's ...World Cup tournaments, but a negligible increase following the 2016 Summer Olympics. Large superstar effects for Alex Morgan and Abby Wambach are found as well as smaller effects for Sam Kerr and Carli Lloyd. Megan Rapinoe has a large star effect, but only for matches played following the Women's World Cups.
Epithelial tissues are defined by polarized epithelial cells that are integrated into tissues and exhibit barrier function in order to regulate what is allowed to pass between cells. Cell-cell ...junctions must be stable enough to promote barrier function and tissue integrity, yet plastic enough to remodel when necessary. This remarkable ability to dynamically sense and respond to changes in cell shape and tissue tension allows cell-cell junctions to remain functional during events that disrupt epithelial homeostasis including morphogenesis, wound healing, and cell division. In order to achieve this plasticity, both tight junctions and adherens junctions are coupled to the underlying actomyosin cytoskeleton. Here, we discuss the importance of the junctional linkage to actomyosin and how a localized zone of active RhoA along with other Rho GTPases work together to orchestrate junctional actomyosin dynamics. We focus on how scaffold proteins help coordinate Rho GTPases, their upstream regulators, and their downstream effectors for efficient, localized Rho GTPase signaling output. Additionally, we highlight important roles junctional actin-binding proteins play in addition to their traditional roles in organizing actin. Together, Rho GTPases, their regulators, and effectors form compartmentalized signaling modules that regulate actomyosin structure and contractility to achieve proper cell-cell adhesion and tissue barriers.
Epithelial integrity and barrier function must be maintained during the complex cell shape changes that occur during cytokinesis in vertebrate epithelial tissue. Here, we investigate how adherens ...junctions and bicellular and tricellular tight junctions are maintained and remodeled during cell division in the Xenopus laevis embryo. We find that epithelial barrier function is not disrupted during cytokinesis and is mediated by sustained tight junctions. Using fluorescence recovery after photobleaching (FRAP), we demonstrate that adherens junction proteins are stabilized at the cleavage furrow by increased tension. We find that Vinculin is recruited to the adherens junction at the cleavage furrow, and that inhibiting recruitment of Vinculin by expressing a dominant-negative mutant increases the rate of furrow ingression. Furthermore, we show that cells neighboring the cleavage plane are pulled between the daughter cells, making a new interface between neighbors, and two new tricellular tight junctions flank the midbody following cytokinesis. Our data provide new insight into how epithelial integrity and barrier function are maintained throughout cytokinesis in vertebrate epithelial tissue.
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•Tight junctions and barrier function are maintained during cytokinesis•Adherens junctions are maintained and reinforced at cleavage furrow by vinculin•After cytokinesis, two nascent tricellular tight junctions flank the midbody•New interface initially forms between neighbor cells, not daughter cells
Using live imaging of Xenopus laevis gastrula embryos, Higashi et al. characterize how epithelial cells maintain tight and adherens junctions during cytokinesis and how new tricellular tight junctions form after division, demonstrating that cell-cell junctions at the cleavage furrow are stabilized and reinforced in a vinculin-dependent manner.
In the past five years, San Diego and St. Louis lost National Football League franchises to Los Angeles. This paper uses daily data on hotel room rentals, average room rates, and hotel revenue to ...examine the effect that losing NFL franchises will have on those cities. For comparison, other events including professional baseball and hockey franchises, Major League Baseball's All-Star Game, and two college football bowl games are considered.
Abstract
Recurrent influenza epidemics and pandemic potential are significant risks to global health. Public health authorities use clinical surveillance to locate and monitor influenza and ...influenza-like cases and outbreaks to mitigate hospitalizations and deaths. Currently, global integration of clinical surveillance is the only reliable method for reporting influenza types and subtypes to warn of emergent pandemic strains. The utility of wastewater surveillance (WWS) during the COVID-19 pandemic as a less resource intensive replacement or complement for clinical surveillance has been predicated on analyzing viral fragments in wastewater. We show here that influenza virus targets are stable in wastewater and partitions favorably to the solids fraction. By quantifying, typing, and subtyping the virus in municipal wastewater and primary sludge during a community outbreak, we forecasted a citywide flu outbreak with a 17-day lead time and provided population-level viral subtyping in near real-time to show the feasibility of influenza virus WWS at the municipal and neighbourhood levels in near real time using minimal resources and infrastructure.
An accurate assessment of liquid-phase mass transport resistances is necessary for understanding and optimizing battery performance using mathematical models. This work combines modeling and ...experiments to quantify tortuosity in electrolyte-filled porous battery structures (separator and active-material film). Tortuosities of separators were measured by two methods, AC impedance and polarization-interrupt, which produced consistent results. We measured an apparent interfacial resistance at the lithium metal electrodes that contributed to both ohmic and diffusional resistance of the cell. The polarization-interrupt experiment was used similarly to measure effective electrolyte transport in porous films of cathode materials, particularly films containing LiFePO
4. An empirical relationship between porosity and the tortuosity of the porous structures was developed. Our results demonstrate that the tortuosity-dependent mass transport resistance in porous separators and electrodes is significantly higher than that predicted by the oft-used Bruggeman relationship.
Resection of small pulmonary nodules with minimally invasive techniques can be challenging when the lesions are not palpable. Localizing theses nodules by electromagnetic navigational bronchoscopy ...(ENB) techniques has not been well studied.
A review of our thoracic surgery database was performed for patients undergoing ENB localization of pulmonary nodules for robotic resection between August 2012 and April 2013.
19 patients were identified who underwent a combined localization with ENB and then da Vinci robotic lung resection. A transbronchial needle biopsy was performed in 14 patients followed by methylene blue dye marking on the pleural surface to localize the lesion. Five patients did not have a needle biopsy and underwent dye marking only. After dye marking, patients underwent robotic resection. Three patients who underwent transbronchial needle biopsy were found to have a diagnosis of malignancy and no diagnostic resection was needed. We proceeded directly to anatomic resection. Four patients had lesions too deep for a wedge resection, and a diagnostic segmentectomy was needed. The remaining 11 patients required a diagnostic wedge resection. The median time for the ENB portion of the procedure was 28 minutes. No adverse events were related to the placement of the dye marker, and no patients underwent conversion to an open procedure to localize the lesion.
We found ENB to be a safe and effective technique for localization of small pulmonary nodules with the diagnostic needle biopsy, possibly altogether negating the need for a wedge resection without adding significant time to the procedure.
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