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1. Instabilities and patterns in a submerged jelling jet

   https://doi.org/10.1039/D1SM00517K  

   Chakrabarti, Aditi; Al-Mosleh, Salem; Mahadevan, L. (November 2021, Soft Matter)

   When a thin stream of aqueous sodium alginate is extruded into a reacting calcium chloride bath, it polymerizes into a soft elastic tube that spontaneously forms helical coils due to the ambient fluid drag. 

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2. Among‐ and within‐population variation in morphology, rewards, and scent in a hawkmoth‐pollinated plant

   https://doi.org/10.1002/ajb2.16030  

   Eisen, Katherine E.; Ma, Rong; Raguso, Robert A. (November 2022, American Journal of Botany)

   Abstract PremiseFloral scent is a complex trait that mediates many plant–insect interactions, but our understanding of how floral scent variation evolves, either independently or in concert with other traits, remains limited. Assessing variation in floral scent at multiple levels of biological organization and comparing patterns of variation in scent to variation in other floral traits can contribute to our understanding of how scent variation evolves in nature. MethodsWe used a greenhouse common garden experiment to investigate variation in floral scent at three scales—within plants, among plants, and among populations—and to determine whether scent, alone or in combination with morphology and rewards, contributes to population differentiation inOenothera cespitosasubsp.marginata. Its range spans most of the biomes in the western United States, such that variation in both the abiotic and biotic environment could contribute to trait variation. ResultsMultiple analytical approaches demonstrated substantial variation among and within populations in compound‐specific and total floral scent measures. Overall, populations were differentiated in morphology and reward traits and in scent. Across populations, coupled patterns of variation in linalool, leucine‐derived compounds, and hypanthium length are consistent with a long‐tongued moth pollination syndrome. ConclusionsThe considerable variation in floral scent detected within populations suggests that, similar to other floral traits, variation in floral scent may have a heritable genetic component. Differences in patterns of population differentiation in floral scent and in morphology and rewards indicate that these traits may be shaped by different selective pressures. 

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3. A note on surfaces in ℂℙ² and ℂℙ²#ℂℙ²

   https://doi.org/10.1090/bproc/218  

   Marengon, Marco; Miller, Allison; Ray, Arunima; Stipsicz, András (June 2024, Proceedings of the American Mathematical Society, Series B)

   In this brief note, we investigate the ${\mathbb{C}\mathbb{P}}^2$-genus of knots, i.e., the least genus of a smooth, compact, orientable surface in ${\mathbb{C}\mathbb{P}}^2\setminus <\#comment/>\stackrel{˚<\#comment/>}{B^4}$bounded by a knot in $S^3$. We show that this quantity is unbounded, unlike its topological counterpart. We also investigate the ${\mathbb{C}\mathbb{P}}^2$-genus of torus knots. We apply these results to improve the minimal genus bound for some homology classes in ${\mathbb{C}\mathbb{P}}^2\mathrm{\#<\#comment/>}{\mathbb{C}\mathbb{P}}^2$. 

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4. Positioning in a collaboration network and performance in competitions: a case study of Kaggle

   https://doi.org/10.1093/jcmc/zmad024  

   Twyman, Marlon; Murić, Goran; Zheng, Weiwei; Baym, ed., Nancy; Ellison, ed., Nicole (June 2023, Journal of Computer-Mediated Communication)

   Abstract Online innovation competitions are ecosystems where institutions source numerous solutions from knowledge workers through a platform intermediary. By considering how an individual competitor’s performance varies based on their social positioning in a competition ecosystem’s collaboration network, we illustrate the value of social networks for individual outcomes in online competitions. The study reports results from Kaggle, a popular online competition platform for data science, where a sample of 350,956 users participated in 2,789 competitions over 4 years. We investigate how the number of collaborations, membership in the largest connected component in the network, and diversity of collaboration experiences impact the points and medals earned and how quickly competitors earn their first medal. Results show that positioning has a positive relationship with performance in competitive ecosystems. Relevant to the future of work, the study considers how knowledge workers in future workplaces should manage their online collaborations. 

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5. Female reproduction and viral infection in a long‐lived mammal

   https://doi.org/10.1111/1365-2656.13799  

   Negrey, Jacob D.; Emery Thompson, Melissa; Dunn, Christopher D.; Otali, Emily; Wrangham, Richard W.; Mitani, John C.; Machanda, Zarin P.; Muller, Martin N.; Langergraber, Kevin E.; Goldberg, Tony L. (October 2022, Journal of Animal Ecology)

   Abstract For energetically limited organisms, life‐history theory predicts trade‐offs between reproductive effort and somatic maintenance. This is especially true of female mammals, for whom reproduction presents multifarious energetic and physiological demands.Here, we examine longitudinal changes in the gut virome (viral community) with respect to reproductive status in wild mature female chimpanzeesPan troglodytes schweinfurthiifrom two communities, Kanyawara and Ngogo, in Kibale National Park, Uganda.We used metagenomic methods to characterize viromes of individual chimpanzees while they were cycling, pregnant and lactating.Females from Kanyawara, whose territory abuts the park's boundary, had higher viral richness and loads (relative quantity of viral sequences) than females from Ngogo, whose territory is more energetically rich and located farther from large human settlements. Viral richness (total number of distinct viruses per sample) was higher when females were lactating than when cycling or pregnant. In pregnant females, viral richness increased with estimated day of gestation. Richness did not vary with age, in contrast to prior research showing increased viral abundance in older males from these same communities.Our results provide evidence of short‐term physiological trade‐offs between reproduction and infection, which are often hypothesized to constrain health in long‐lived species. 

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