A Bio-Based Pro-Antimicrobial Polymer Network Via Degradable Acetal Linkages

The synthesis of a fully degradable, bio-based, sustained release, pro-antimicrobial polymer network comprised of degradable acetals (PANDA) is reported. The active antimicrobial agent – p-anisaldehyde (pA) (an extract from star anise) – was converted into a UV curable acetal containing pro-antimicrobial monomer and subsequently photopolymerized into a homogenous thiol-ene network. Under neutral to acidic conditions (pH \u3c 8), the PANDAs undergo surface erosion and exhibit sustained release of pA over 38 days. The release of pA from PANDAs was shown to be effective against both bacterial and fungal pathogens. From a combination of confocal microscopy and transmission electron microscopy, we observed that the released pA disrupts the cell membrane. Additionally, we demonstrated that PANDAs have minimal cytotoxicity towards both epithelial cells and macrophages. Although a model platform, these results point to promising pathways for the design of fully degradable sustained-release antimicrobial systems with potential applications in agriculture, pharmaceuticals, cosmetics, household/personal care, and food industries

Actin and microtubules drive differential aspects of planar cell polarity in multiciliated cells

Actin dynamics are required for proper cilia spacing, global coordination of cilia polarity, and coordination of metachronic cilia beating, whereas cytoplasmic microtubule dynamics are required for local coordination of polarity between neighboring cilia

A Broadly Implementable Research Course in Phage Discovery and Genomics for First-Year Undergraduate Students

Engaging large numbers of undergraduates in authentic scientific discovery is desirable but difficult to achieve. We have developed a general model in which faculty and teaching assistants from diverse academic institutions are trained to teach a research course for first-year undergraduate students focused on bacteriophage discovery and genomics. The course is situated within a broader scientific context aimed at understanding viral diversity, such that faculty and students are collaborators with established researchers in the field. The Howard Hughes Medical Institute (HHMI) Science Education Alliance Phage Hunters Advancing Genomics and Evolutionary Science (SEA-PHAGES) course has been widely implemented and has been taken by over 4,800 students at 73 institutions. We show here that this alliance-sourced model not only substantially advances the field of phage genomics but also stimulates students’ interest in science, positively influences academic achievement, and enhances persistence in science, technology, engineering, and mathematics (STEM) disciplines. Broad application of this model by integrating other research areas with large numbers of early-career undergraduate students has the potential to be transformative in science education and research training

Expanding the diversity of mycobacteriophages: insights into genome architecture and evolution.

Mycobacteriophages are viruses that infect mycobacterial hosts such as Mycobacterium smegmatis and Mycobacterium tuberculosis. All mycobacteriophages characterized to date are dsDNA tailed phages, and have either siphoviral or myoviral morphotypes. However, their genetic diversity is considerable, and although sixty-two genomes have been sequenced and comparatively analyzed, these likely represent only a small portion of the diversity of the mycobacteriophage population at large. Here we report the isolation, sequencing and comparative genomic analysis of 18 new mycobacteriophages isolated from geographically distinct locations within the United States. Although no clear correlation between location and genome type can be discerned, these genomes expand our knowledge of mycobacteriophage diversity and enhance our understanding of the roles of mobile elements in viral evolution. Expansion of the number of mycobacteriophages grouped within Cluster A provides insights into the basis of immune specificity in these temperate phages, and we also describe a novel example of apparent immunity theft. The isolation and genomic analysis of bacteriophages by freshman college students provides an example of an authentic research experience for novice scientists

A Broadly Implementable Research Course in Phage Discovery and Genomics for First-Year Undergraduate Students

Engaging large numbers of undergraduates in authentic scientific discovery is desirable but difficult to achieve. We have developed a general model in which faculty and teaching assistants from diverse academic institutions are trained to teach a research course for first-year undergraduate students focused on bacteriophage discovery and genomics. The course is situated within a broader scientific context aimed at understanding viral diversity, such that faculty and students are collaborators with established researchers in the field. The Howard Hughes Medical Institute (HHMI) Science Education Alliance Phage Hunters Advancing Genomics and Evolutionary Science (SEA-PHAGES) course has been widely implemented and has been taken by over 4,800 students at 73 institutions. We show here that this alliance-sourced model not only substantially advances the field of phage genomics but also stimulates students’ interest in science, positively influences academic achievement, and enhances persistence in science, technology, engineering, and mathematics (STEM) disciplines. Broad application of this model by integrating other research areas with large numbers of early-career undergraduate students has the potential to be transformative in science education and research training

A Preliminary Examination of Derived Relational Responding in the Context of Body Image

Relational Frame Theory (RFT), a contemporary behavioral account of language and cognition, has been offered as an explanatory model of the development and maintenance of body image disturbance. RFT proposes derived relational responding (DRR) as a process through which the functions of a stimulus are transformed consistent with its relation with other stimuli (and absent direct learning contingencies. Conceptual work has assumed DRR to be central to the development and treatment of body image disturbance. This study offers the first empirical investigation of DRR with body-image stimuli, and untrained approach-andescape functions. Participants readily demonstrated mutual and combinatorial entailment with stimuli they generated to represent their own body image, along with images fatter and thinner than themselves. Participants also readily demonstrated transformation of untrained approach-and-escape functions consistent with that of thinner and fatter body images. These findings provide a preliminary demonstration of DRR in the context of body image disturbance and support further research applying RFT in this area

An examination of transformation of evaluative and consequential functions through derived relations with participant generated values-relevant stimuli

Values-affirmation interventions have demonstrated efficacy in increasing approach behavior in the context of potential threat. In other words, writing about values seems associated with changes to the functions of previously aversive events. Evaluative conditioning and derived relational responding have been offered as possible mechanisms by which values interventions change behavior. The current study aimed to extend the extant literature by demonstrating derived relational responding and subsequent transformation of evaluative and consequential functions with values-relevant stimuli. Participants were 34 undergraduate students. Participants generated personally meaningful values-relevant stimuli after engaging in a values-affirmation task and were subsequently trained through matching to sample to coordinate a subset of those stimuli to arbitrary stimuli. All participants exhibited mutual entailment, and all but one exhibited combinatorial entailment, suggesting that individuals learn to coordinate events with values quite readily. Further, there was evidence of transformation of functions, both in terms of changes in ratings of derived stimuli and in terms of changes in approach and escape behavior. These data are offered in support of continued scientific exploration of what values are, how they emerge, and how they are best intervened upon

Programmable Porous Polymers via Direct Bubble Writing with Surfactant-Free Inks

Fabrication of macroporous polymers with functionally graded architecture or chemistry bears transformative potential in acoustic damping, energy storage materials, flexible electronics, and filtration, but is hardly reachable with current processes. Here, we introduce thiol-ene chemistries in direct bubble writing, a recent technique for additive manufacturing of foams with locally controlled cell size, density and macroscopic shape. Surfactant-free and solvent-free graded 3D foams without drying-induced shrinkage were fabricated by direct bubble writing at an unparalleled ink viscosity of 410 cP (40 times higher than previous formulations). Functionalities including shape memory, high glass transition temperatures ( \u3e25 °C), and chemical gradients were demonstrated. These results extend direct bubble writing from aqueous inks to non-aqueous formulations, while the liquid flow rate (3 mL min-1) exceeds chip microfluidic techniques. Altogether, direct bubble writing with thiol-ene inks promises rapid one-step fabrication of functional materials with locally controlled gradients in the chemical, mechanical, and architectural domains