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  1. The versatile functions of fluorescent proteins (FPs) as fluorescence biomarkers depend on their intrinsic chromophores interacting with the protein environment. Besides X-ray crystallography, vibrational spectroscopy represents a highly valuable tool for characterizing the chromophore structure and revealing the roles of chromophore–environment interactions. In this work, we aim to benchmark the ground-state vibrational signatures of a series of FPs with emission colors spanning from green, yellow, orange, to red, as well as the solvated model chromophores for some of these FPs, using wavelength-tunable femtosecond stimulated Raman spectroscopy (FSRS) in conjunction with quantum calculations. We systematically analyzed and discussed four factors underlying the vibrational properties of FP chromophores: sidechain structure, conjugation structure, chromophore conformation, and the protein environment. A prominent bond-stretching mode characteristic of the quinoidal resonance structure is found to be conserved in most FPs and model chromophores investigated, which can be used as a vibrational marker to interpret chromophore–environment interactions and structural effects on the electronic properties of the chromophore. The fundamental insights gained for these light-sensing units (e.g., protein active sites) substantiate the unique and powerful capability of wavelength-tunable FSRS in delineating FP chromophore properties with high sensitivity and resolution in solution and protein matrices. The comprehensive characterization for various FPs across a colorful palette could also serve as a solid foundation for future spectroscopic studies and the rational engineering of FPs with diverse and improved functions. 
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    Free, publicly-accessible full text available August 1, 2024
  2. Benjamin, L ; Henderson, J A ; Hines, E M (Ed.)
    The topic of engineering identity is neither new nor complete in its coverage within current literature. In fact, although this body of work predates the last ten years, researchers have argued that some of the most significant burgeoning in this area has occurred in the last decade. By applying both quantitative and qualitative lenses to this inquiry, researchers have concluded that, much like a STEM identity, an engineering identity describes how students see themselves, their competence and potential for success in the academic and career context of the field. To further examine the latter component i.e. potential for academic and career success, we attend to an emerging concept of an entrepreneurial engineering identity. This preliminary work unfolded organically; the authors’ primary goal involved a larger Interpretative Phenomenological Analysis (IPA) study that investigated persistence and advanced degree aspirations among 20 Black male engineering undergraduate students from a variety of institutional settings. While we did not intentionally seek to examine this emerging component of engineering identity, our preliminary analysis of participants’ interview data led us down this path. What we observed was a latent phenomenon of interest among participants: these Black male engineering undergraduates recurringly articulated clear intentions for academic and career opportunities that integrated business components into their engineering realities. Kegan’s (1984, 1994) Theory of Meaning-Making provided a framework for understanding how participants perceived the development of business acumen as a strategy for ascending existing corporate/organizational structures, creating new business pathways, and promoting corporate social responsibility. Based on these findings, the authors were inspired to explore the conceptual development of an entrepreneurial engineering identity and its practical application to engineering degree (re)design, student academic advisory and career planning. 
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  3. Abstract

    Supernova (SN) SN H0pe is a gravitationally lensed, triply imaged, Type Ia SN (SN Ia) discovered in James Webb Space Telescope imaging of the PLCK G165.7+67.0 cluster of galaxies. Well-observed multiply imaged SNe provide a rare opportunity to constrain the Hubble constant (H0), by measuring the relative time delay between the images and modeling the foreground mass distribution. SN H0pe is located atz= 1.783 and is the first SN Ia with sufficient light-curve sampling and long enough time delays for anH0inference. Here we present photometric time-delay measurements and SN properties of SN H0pe. Using JWST/NIRCam photometry, we measure time delays of Δtab=116.69.3+10.8observer-frame days and Δtcb=48.64.0+3.6observer-frame days relative to the last image to arrive (image 2b; all uncertainties are 1σ), which corresponds to a ∼5.6% uncertainty contribution forH0assuming 70 km s−1Mpc−1. We also constrain the absolute magnification of each image toμa=4.31.8+1.6,μb=7.62.6+3.6,μc=6.41.5+1.6by comparing the observed peak near-IR magnitude of SN H0pe to the nonlensed population of SNe Ia.

     
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  4. Free, publicly-accessible full text available September 1, 2024
  5. The topic of engineering identity is neither new nor complete in its coverage within current literature. In fact, although this body of work predates the last ten years, researchers have argued that some of the most significant burgeoning in this area has occurred in the last decade. By applying both quantitative and qualitative lenses to this inquiry, researchers have concluded that, much like a STEM identity, an engineering identity describes how students see themselves, their competence and potential for success in the academic and career context of the field. To further examine the latter component i.e. potential for academic and career success, we attend to an emerging concept of an entrepreneurial engineering identity. This preliminary work unfolded organically; the authors’ primary goal involved a larger Interpretative Phenomenological Analysis (IPA) study that investigated persistence and advanced degree aspirations among 20 Black male engineering undergraduate students from a variety of institutional settings. While we did not intentionally seek to examine this emerging component of engineering identity, our preliminary analysis of participants’ interview data led us down this path. What we observed was a latent phenomenon of interest among participants: these Black male engineering undergraduates recurringly articulated clear intentions for academic and career opportunities that integrated business components into their engineering realities. Kegan’s (1984, 1994) Theory of Meaning-Making provided a framework for understanding how participants perceived the development of business acumen as a strategy for ascending existing corporate/organizational structures, creating new business pathways, and promoting corporate social responsibility. Based on these findings, authors were inspired to explore the conceptual development of an entrepreneurial engineering identity and its practical application to engineering degree (re)design, student academic advisory and career planning. 
    more » « less