Showing papers by "Jennifer M. Heemstra published in 2019"

FAIL Is Not a Four-Letter Word: A Theoretical Framework for Exploring Undergraduate Students' Approaches to Academic Challenge and Responses to Failure in STEM Learning Environments.

Abstract: Navigating scientific challenges, persevering through difficulties, and coping with failure are considered hallmarks of a successful scientist. However, relatively few studies investigate how undergraduate science, technology, engineering, and mathematics (STEM) students develop these skills and dispositions or how instructors can facilitate this development in undergraduate STEM learning contexts. This is a critical gap, because the unique cultures and practices found in STEM classrooms are likely to influence how students approach challenges and deal with failures, both during their STEM education and in the years that follow. To guide research aimed at understanding how STEM students develop a challenge-engaging disposition and the ability to adaptively cope with failure, we generate a model representing hypotheses of how students might approach challenges and respond to failures in undergraduate STEM learning contexts. We draw from theory and studies investigating mindset, goal orientations, attributions, fear of failure, and coping to inform our model. We offer this model as a tool for the community to test, revise, elaborate, or refute. Finally, we urge researchers and educators to consider the development, implementation, and rigorous testing of interventions aimed at helping students develop a persevering and challenge-engaging disposition within STEM contexts.

Bilingual Peptide Nucleic Acids: Encoding the Languages of Nucleic Acids and Proteins in a Single Self-Assembling Biopolymer.

Abstract: Nucleic acids and proteins are the fundamental biopolymers that support all life on Earth. Nucleic acids store large amounts of information in nucleobase sequences while peptides and proteins utilize diverse amino acid functional groups to adopt complex structures and perform wide-ranging activities. Although nature has evolved machinery to read the nucleic acid code and translate it into amino acid code, the extant biopolymers are restricted to encoding amino acid or nucleotide sequences separately, limiting their potential applications in medicine and biotechnology. Here we describe the design, synthesis, and stimuli-responsive assembly behavior of a bilingual biopolymer that integrates both amino acid and nucleobase sequences into a single peptide nucleic acid (PNA) scaffold to enable tunable storage and retrieval of tertiary structural behavior and programmable molecular recognition capabilities. Incorporation of a defined sequence of amino acid side-chains along the PNA backbone yields amphiphiles having a "protein code" that directs self-assembly into micellar architectures in aqueous conditions. However, these amphiphiles also carry a "nucleotide code" such that subsequent introduction of a complementary RNA strand induces a sequence-specific disruption of assemblies through hybridization. Together, these properties establish bilingual PNA as a powerful biopolymer that combines two information systems to harness structural responsiveness and sequence recognition. The PNA scaffold and our synthetic system are highly generalizable, enabling fabrication of a wide array of user-defined peptide and nucleotide sequence combinations for diverse future biomedical and nanotechnology applications.

Small-Molecule Sequestration Using Aptamer-Functionalized Membranes

Abstract: Sequestration of small molecules from aqueous solutions poses a significant and important challenge in environmental science and human health. Current methods focus on broadly sequestering all smal...

Thermostability Trends of TNA:DNA Duplexes Reveal Strong Purine Dependence.

Abstract: The development of high fidelity polymerases and streamlined synthesis of threose nucleic acid (TNA) triphosphates and phosphoramidites has made TNA accessible as a motif for generating nuclease-re...

Selective enrichment of A-to-I edited transcripts from cellular RNA using Endonuclease V

Abstract: Immunoprecipitation enrichment has significantly improved the sensitivity and accuracy of detecting RNA modifications in the transcriptome. However, there are no existing methods for selectively isolating adenosine-to-inosine (A-to-I) edited RNAs. Here we show that Escherichia coli Endonuclease V (eEndoV), an inosine-cleaving enzyme, can be repurposed to bind and isolate A-to-I edited transcripts from cellular RNA through adjustment of cationic conditions. While Mg2+ is required for eEndoV catalysis, it has also been shown that similar levels of Ca2+ instead promote binding of inosine without cleavage. Leveraging these properties, we observe that Ca2+-supplemented eEndoV is highly specific for inosine in RNA and exhibits low nanomolar binding affinity. We then demonstrate EndoVIPER (Endonuclease Vinosine precipitation enrichment) as a facile and robust method to isolate A-to-I edited transcripts from cellular RNA. We envision the use of this approach as a straightforward and cost-effective strategy to enrich edited RNAs and detect A-to-I sites with improved sensitivity and fidelity.

Self-Care Is Not the Enemy of Performance.

Abstract: The highly competitive nature of academic environments might seem to suggest that success can only be obtained at the cost of taking good care of oneself. However, sacrificing self-care can be extremely harmful. Herein, we explore ways that high performance and self-care can be mutually reinforcing and produce long-term success.