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1. Voluntary environmental effort under ( s , S ) inventory policy*

   https://doi.org/10.1080/00207543.2023.2242968  

   Bensoussan, Alain; El_Ouardighi, Fouad (January 2024, International Journal of Production Research)

   Prior research on inventory control has been wide ranging, yet the environmental implications of an (s,S) inventory policy remain uninvestigated. This paper seeks to bridge the gap by characterising a firm’s voluntary environmental policy in the setup of an (s,S) inventory control policy. We suggest a mixed model structure wherein, due to the presence of fixed production costs, the inventory is determined continuously by sales and impulsively with ordering decisions obeying an optimal stopping process, while the uncertain sales process is controlled by continuous-time environmental goodwill-related decisions. We show that a firm should successively use voluntary environmental efforts to stimulate its sales when there is inventory and to increase backlogging to improve its production efficiency. Given the recurrent pattern of this policy, we conclude that voluntary environmental efforts under an (s,S) inventory control is not compatible with using these efforts as a means to generate ephemeral reputation insurance. 

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2. 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)

   SUMMARY 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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3. s- process enrichment of ultrafaint dwarf galaxies

   https://doi.org/10.1093/mnras/stab1487  

   Tarumi, Yuta; Suda, Takuma; van de Voort, Freeke; Inoue, Shigeki; Yoshida, Naoki; Frebel, Anna (June 2021, Monthly Notices of the Royal Astronomical Society)

   null (Ed.)

   ABSTRACT We study the production of barium (Ba) and strontium (Sr) in ultrafaint dwarf (UFDs) galaxies. Both r- and s- processes produce these elements, and one can infer the contribution of the r-process from the characteristic r-process abundance pattern, whereas the s-process contribution remains largely unknown. We show that the current s-process yield from asymptotic giant branch (AGB) stars is not sufficient to explain the Ba and Sr abundances observed in UFDs. Production of these elements would need to be efficient from the beginning of star formation in the galaxies. The discrepancy of nearly or more than 1 dex is not reconciled even if we consider s-process in super-AGB stars. We consider a possible resolution by assuming rotating massive stars (RMSs) and electron-capture supernovae (ECSNe) as additional contributors. We find that the RMSs could be the origin of Ba in UFDs if ∼10 per cent of massive stars are rotating at 300 km s−1. As for ECSNe, we argue that their fraction is less than 2 per cent of core-collapse supernova. It narrows the progenitor mass-range to $${\lesssim}0.1\, \mathrm{M}_\odot$$ at −3 ≲ [Fe/H] ≲ −2. We also explore another resolution by modifying the stellar initial mass function (IMF) in UFDs and find a top-light IMF model that reproduces the observed level of Ba-enrichment. Future observations that determine or tightly constrain the europium and nitrogen abundances are crucial to identify the origin of Ba and Sr in UFDs. 

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4. Nebular Spectroscopy of Kepler ’s Brightest Supernova

   https://doi.org/10.3847/2041-8213/aaf9b1  

   Dimitriadis, G.; Rojas-Bravo, C.; Kilpatrick, C. D.; Foley, R. J.; Piro, A. L.; Brown, J. S.; Guhathakurta, P.; Quirk, A. C.; Rest, A.; Strampelli, G. M.; et al (January 2019, The Astrophysical Journal)
5. The s Process and Beyond

   https://doi.org/10.1146/annurev-nucl-102422-080857  

   Lugaro, Maria; Pignatari, Marco; Reifarth, René; Wiescher, Michael (September 2023, Annual Review of Nuclear and Particle Science)

   Neutron captures produce the vast majority of abundances of elements heavier than iron in the Universe. Beyond the classical slow ( s) and rapid ( r) processes, there is observational evidence for neutron-capture processes that operate at neutron densities in between, at different distances from the valley of β stability. Here, we review the main properties of the s process within the general context of neutron-capture processes and the nuclear physics input required to investigate it. We describe massive stars and asymptotic giant branch stars as the s-process astrophysical sites and discuss the related physical uncertainties. We also present current observational evidence for the s process and beyond, which ranges from stellar spectroscopic observations to laboratory analysis of meteorites. 

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