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Abstract Dust is a key component of galaxies, but its properties during the earliest eras of structure formation remain elusive. Here we present a simple semi-analytic model of the dust distribution in galaxies atz≳ 5. We calibrate the free parameters of this model to estimates of the UV attenuation (using the IRX-βrelation between infrared emission and the UV spectral slope) and to ALMA measurements of dust emission. We find that the observed dust emission requires that most of the dust expected in these galaxies is retained (assuming a similar yield to lower-redshift sources), but if the dust is spherically distributed, the modest attenuation requires that it be significantly more extended than the stars. Interestingly, the retention fraction is larger for less massive galaxies in our model. However, the required radius is a significant fraction of the host's virial radius and is larger than the estimated extent of dust emission from stacked high-zgalaxies. These can be reconciled if the dust is distributed anisotropically, with typical covering fractions of ∼ 0.2–0.7 in bright galaxies and ≲ 0.1 in fainter ones. 

Abstract The use of photopolymerization is expanding across a multitude of biomedical applications, from drug delivery to bioprinting. Many of these current and emerging photopolymerization systems employ visible light, as motivated by safety and energy efficiency considerations. However, the “library” of visible light initiators is limited compared with the wealth of options available for UV polymerization. Furthermore, the synthesis of traditional photoinitiators relies on diminishing raw materials, and several traditional photoinitiators are considered emerging environmental contaminants. As such, there has been recent focus on identifying and characterizing biologically sourced, visible light‐based photoinitiator systems that can be effectively used in photopolymerization applications. In this regard, several bio‐sourced molecules have been shown to act as photoinitiators, primarily through Type II photoinitiation mechanisms. However, whether bio‐sourced molecules can also act as effective synergists in these reactions remains unknown. In this study, we evaluated the effectiveness of bio‐sourced synergist candidates, with a focus on amino acids, due to their amine functional groups, in combination with two bio‐sourced photoinitiator molecules: riboflavin and curcumin. We tested the effectiveness of these photoinitiator systems under both violet (405 nm) and blue (460–475 nm) light using photo‐rheology. We found that several synergist candidates, namely lysine, arginine, and histidine, increased the polymerization effectiveness of riboflavin when used with both violet and blue light. With curcumin, we found that almost all tested synergist candidates slightly decreased the polymerization effectiveness compared with curcumin alone under both light sources. These results show that bio‐sourced molecules have the potential to be used as synergists with bio‐sourced photoinitiators in visible light photopolymerization. However, more work must be done to fully characterize these reactions and to investigate more synergist candidates. Ultimately, this information is expected to expand the range of available visible light‐based photoinitiator systems and increase their sustainability. 

The National Science Board has declared that the long-term vitality of the U.S. workforce relies on the full range of science, technology, engineering, and mathematics (STEM) career pathways being available to all Americans. This declaration was premised on the increasing diversity in the U.S. population [1] and the need for multiple perspectives on the complex problems faced by society [2]. Thus, the National Science Foundation, the National Academies of Science, Engineering, and Medicine, the American Institutes of Research, and the Council of Graduate Schools have stated that the increased participation of women and members of racially minoritized and marginalized (RMM, including Black, Hispanic/Latinx, and Indigenous) groups in STEM is imperative to maintain the U.S. standing as a global leader in innovation. Because engineering doctoral graduates account for a large share of the innovation workforce [3], the ongoing lack of diversity in the engineering doctoral workforce remains a problem with far-reaching implications for the U.S. economy. The ‘mold’ for an engineering doctoral student was created by graduate education's earliest beneficiaries: young, White, and single men. Students who fall outside this mold, including women, people of color, older people, people with children, and people with disabilities are more likely than their traditional graduate student counterparts to report climate-related issues [4]. While some studies of university or campus-level climate for students have included doctoral students in general, few studies disaggregate findings by discipline or by demographic categories beyond gender identity and race/ethnicity. In engineering, Riley, Slaton, and Pawley’s [5] observed that the engineering education research community tends to take up issues of diversity focused on “women and [racial and ethnic] minorities while queerness, class, nationality, disability, age, and other forms of difference are, for the most part, not seen as requiring address”. This literature review was conducted as a preliminary assessment of the available research literature produced by the engineering education community on organizational climate affecting the retention of engineering doctoral students from diverse backgrounds. We seek to understand this specific student group’s retention as an organizational climate issue and use an intersectional approach to consider the meaning and relevance of students’ belonging, simultaneously to multiple social categories, such as gender identity, sexual orientation, socioeconomic background, race/ethnicity, and disability status within the context of engineering doctoral education as a first step to building a climate survey instrument. Searches on February 2, 2023, for existing scoping reviews and systematic reviews on this topic conducted on JBI Evidence Synthesis, the Cochrane Database of Systematic Reviews, and the Campbell Collaboration did not provide results [6]. The objective of this literature review is to explore how the concept of ‘climate’ is being used in the context of doctoral engineering student retention to degree completion and gather a body of evidence of climate factors. To do this, we conducted a targeted literature review and used intersectionality [7] [8] as our approach to interpreting the literature, as we aim to understand how climate affects the retention of engineering doctoral students from diverse backgrounds. In this paper, we first briefly present our understanding of organizational climate and intersectionality, then we explain our methodology, followed by results and finally discuss our analysis of the climate literature in engineering. 

Summary Although most xyloglucans (XyGs) biosynthesis enzymes have been identified, the molecular mechanism that defines XyG branching patterns is unclear. Four out of five XyG xylosyltransferases (XXT1, XXT2, XXT4, and XXT5) are known to add the xylosyl residue from UDP‐xylose onto a glucan backbone chain; however, the function of XXT3 has yet to be demonstrated.Singlexxt3and triplexxt3xxt4xxt5mutantArabidopsis(Arabidopsis thaliana) plants were generated using CRISPR‐Cas9 technology to determine the specific function of XXT3.Combined biochemical, bioinformatic, and morphological data conclusively established for the first time that XXT3, together with XXT4 and XXT5, adds xylosyl residue specifically at the third glucose in the glucan chain to synthesize XXXG‐type XyGs. We propose that the specificity of XXT3, XXT4, and XXT5 is directed toward the prior synthesis of the acceptor substrate by the other two enzymes, XXT1 and XXT2. We also conclude that XXT5 plays a dominant role in the synthesis of XXXG‐type XyGs, while XXT3 and XXT4 complementarily contribute their activities in a tissue‐specific manner.The newly generatedxxt3xxt4xxt5mutant produces only XXGG‐type XyGs, which further helps to understand the impact of structurally deficient polysaccharides on plant cell wall organization, growth, and development.