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1. Temperature dependence of collisional broadening and shift for the Kr 4 p 6 S 01→5 p [3/2] 2 electronic transition

   https://doi.org/10.1364/AO.380102  

   Sahoo, Abinash ; Zelenak, Dominic ; Narayanaswamy, Venkateswaran ( February 2020 , Applied Optics)

   Temperature scaling of collisional broadening parameters for krypton (absorber)$4p^6{S}_0^1\to <\#comment/>5p[3/2{]}_2$electronic transition centered at 107.3 nm in the presence of major combustion species (perturber) is investigated. The absorption spectrum in the vicinity of the transition is obtained from the fluorescence due to the two-photon excitation scan of krypton. Krypton was added in small amounts to major combustion species such as${\mathrm{C}\mathrm{H}}_4$,${\mathrm{C}\mathrm{O}}_2$,${\mathrm{N}}_2$, and air, which then heated to elevated temperatures when flowed through a set of heated coils. In a separate experimental campaign, laminar premixed flat flame product mixtures of methane combustion were employed to extend the investigations to higher temperature ranges relevant to combustion. Collisional full width half maximum (FWHM) ($w_C$) and shift (${\mathrm{\delta <\#comment/>}}_C$) were computed from the absorption spectrum by synthetically fitting Voigt profiles to the excitation scans, and their corresponding temperature scaling was determined by fitting power-law temperature dependencies to the$w_C$and${\mathrm{\delta <\#comment/>}}_C$data for each perturber species. The temperature exponents of$w_C$and${\mathrm{\delta <\#comment/>}}_C$for all considered combustion species (perturbers) were$-<\#comment/>0.73$and$-<\#comment/>0.6$, respectively. Whereas the temperature exponents of$w_C$are closer to the value ($-<\#comment/>0.7$) predicted by the dispersive interaction collision theory, the corresponding exponents of${\mathrm{\delta <\#comment/>}}_C$are in between the dispersive interaction theory and the kinetic theory of hard-sphere collisions. Comparison with existing literature on broadening parameters of NO, OH, and CO laser-induced fluorescence spectra reveal interesting contributions from non-dispersive interactions on the temperature exponent.

    

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2. Sex‐specific evolution of a Drosophila sensory system via interacting cis‐ and trans‐ regulatory changes

   https://doi.org/10.1111/ede.12398  

   Luecke, David ; Rice, Gavin ; Kopp, Artyom ( March 2022 , Evolution & Development)

   The evolution of gene expression viacis‐regulatory changes is well established as a major driver of phenotypic evolution. However, relatively little is known about the influence of enhancer architecture and intergenic interactions on regulatory evolution. We address this question by examining chemosensory system evolution inDrosophila.Drosophila prolongatamales show a massively increased number of chemosensory bristles compared to females and males of sibling species. This increase is driven by sex‐specific transformation of ancestrally mechanosensory organs. Consistent with this phenotype, thePox neurotranscription factor (Poxn), which specifies chemosensory bristle identity, shows expanded expression inD. prolongatamales.Poxnexpression is controlled by nonadditive interactions among widely dispersed enhancers. Although someD. prolongata Poxnenhancers show increased activity, the additive component of this increase is slight, suggesting that most changes inPoxnexpression are due to epistatic interactions betweenPoxnenhancers andtrans‐regulatory factors. Indeed, the expansion ofD. prolongata Poxnenhancer activity is only observed in cells that expressdoublesex(dsx), the gene that controls sexual differentiation inDrosophilaand also shows increased expression inD. prolongatamales due tocis‐regulatory changes. Although expandeddsxexpression may contribute to increased activity ofD. prolongata Poxnenhancers, this interaction is not sufficient to explain the full expansion ofPoxnexpression, suggesting thatcis–transinteractions betweenPoxn, dsx, and additional unknown genes are necessary to produce the derivedD. prolongataphenotype. Overall, our results demonstrate the importance of epistatic gene interactions for evolution, particularly when pivotal genes have complex regulatory architecture.

    

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3. Sequence analysis of the Petunia inflata S ‐locus region containing 17 S‐Locus F‐Box genes and the S‐RNase gene involved in self‐incompatibility

   https://doi.org/10.1111/tpj.15005  

   Wu, Lihua ; Williams, Justin S. ; Sun, Linhan ; Kao, Teh‐Hui ( October 2020 , The Plant Journal)

   Self‐incompatibility inPetuniais controlled by the polymorphicS‐locus, which containsS‐RNaseencoding the pistil determinant and 16–20S‐locus F‐box(SLF) genes collectively encoding the pollen determinant. Here we sequenced and assembled approximately 3.1 Mb of theS₂‐haplotype of theS‐locus inPetunia inflatausing bacterial artificial chromosome clones collectively containing all 17SLFgenes,SLFLike1, andS‐RNase. TwoSLFpseudogenes and 28 potential protein‐coding genes were identified, 20 of which were also found at theS‐loci of both theS_6a‐haplotype ofP. inflataand theS_N‐haplotype of self‐compatiblePetunia axillaris, but not in theS‐locus remnants of self‐compatible potato (Solanum tuberosum) and tomato (Solanum lycopersicum). Comparative analyses ofS‐locus sequences of these threeS‐haplotypes revealed potential genetic exchange in the flanking regions ofSLFgenes, resulting in highly similar flanking regions between different types ofSLFand between alleles of the same type ofSLFof differentS‐haplotypes. The high degree of sequence similarity in the flanking regions could often be explained by the presence of similar long terminal repeat retroelements, which were enriched at theS‐loci of all threeS‐haplotypes and in the flanking regions of allS‐locus genes examined. We also found evidence of the association of transposable elements withSLFpseudogenes. Based on the hypothesis thatSLFgenes were derived by retrotransposition, we identified 10F‐boxgenes as putativeSLFparent genes. Our results shed light on the importance of non‐coding sequences in the evolution of theS‐locus, and on possible evolutionary mechanisms of generation, proliferation, and deletion ofSLFgenes.

    

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4. Revealing the Cooperative Relationship between Spin, Energy, and Polarization Parameters toward Developing High‐Efficiency Exciplex Light‐Emitting Diodes

   https://doi.org/10.1002/adma.201904114  

   Wang, Miaosheng ; Huang, Yi‐Hsuan ; Lin, Kai‐Siang ; Yeh, Tzu‐Hung ; Duan, Jiashun ; Ko, Tzu‐Yu ; Liu, Shun‐Wei ; Wong, Ken‐Tsung ; Hu, Bin ( September 2019 , Advanced Materials)

   Experimental studies to reveal the cooperative relationship between spin, energy, and polarization through intermolecular charge‐transfer dipoles to harvest nonradiative triplets into radiative singlets in exciplex light‐emitting diodes are reported. Magneto‐photoluminescence studies reveal that the triplet‐to‐singlet conversion in exciplexes involves an artificially generated spin‐orbital coupling (SOC). The photoinduced electron parametric resonance measurements indicate that the intermolecular charge‐transfer occurs with forming electric dipoles (D^+•→A^−•), providing the ionic polarization to generate SOC in exciplexes. By having different singlet‐triplet energy differences (ΔE_ST) in 9,9′‐diphenyl‐9H,9′H‐3,3′‐bicarbazole (BCzPh):3′,3′″,3′″″‐(1,3,5‐triazine‐2,4,6‐triyl)tris(([1,1′‐biphenyl]‐3‐carbonitrile)) (CN‐T2T) (ΔE_ST= 30 meV) and BCzPh:bis‐4,6‐(3,5‐di‐3‐pyridylphenyl)‐2‐methyl‐pyrimidine (B3PYMPM) (ΔE_ST= 130 meV) exciplexes, the SOC generated by the intermolecular charge‐transfer states shows large and small values (reflected by different internal magnetic parameters: 274 vs 17 mT) with high and low external quantum efficiency maximum, EQE_max(21.05% vs 4.89%), respectively. To further explore the cooperative relationship of spin, energy, and polarization parameters, different photoluminescence wavelengths are selected to concurrently change SOC, ΔE_ST, and polarization while monitoring delayed fluorescence. When the electron clouds become more deformed at a longer emitting wavelength due to reduced dipole (D^+•→A^−•) size, enhanced SOC, increased orbital polarization, and decreased ΔE_STcan simultaneously occur to cooperatively operate the triplet‐to‐singlet conversion.

    

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5. Compensatory trans -regulatory alleles minimizing variation in TDH3 expression are common within Saccharomyces cerevisiae

   https://doi.org/10.1002/evl3.137  

   Metzger, Brian P. H. ; Wittkopp, Patricia J. ( October 2019 , Evolution Letters)

   Heritable variation in gene expression is common within species. Much of this variation is due to genetic differences outside of the gene with altered expression and is trans-acting. This trans-regulatory variation is often polygenic, with individual variants typically having small effects, making the genetic architecture and evolution of trans-regulatory variation challenging to study. Consequently, key questions about trans-regulatory variation remain, including the variability of trans-regulatory variation within a species, how selection affects trans-regulatory variation, and how trans-regulatory variants are distributed throughout the genome and within a species. To address these questions, we isolated and measured trans-regulatory differences affecting TDH3 promoter activity among 56 strains of Saccharomyces cerevisiae, finding that trans-regulatory backgrounds varied approximately twofold in their effects on TDH3 promoter activity. Comparing this variation to neutral models of trans-regulatory evolution based on empirical measures of mutational effects revealed that despite this variability in the effects of trans-regulatory backgrounds, stabilizing selection has constrained trans-regulatory differences within this species. Using a powerful quantitative trait locus mapping method, we identified ∼100 trans-acting expression quantitative trait locus in each of three crosses to a common reference strain, indicating that regulatory variation is more polygenic than previous studies have suggested. Loci altering expression were located throughout the genome, and many loci were strain specific. This distribution and prevalence of alleles is consistent with recent theories about the genetic architecture of complex traits. In all mapping experiments, the nonreference strain alleles increased and decreased TDH3 promoter activity with similar frequencies, suggesting that stabilizing selection maintained many trans-acting variants with opposing effects. This variation may provide the raw material for compensatory evolution and larger scale regulatory rewiring observed in developmental systems drift among species.

    

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