There is a growing consensus that traits offer a powerful way to examine the relationship between the environment, organismal strategies, species interactions, and ecological success. To date, trait-based research has largely been focusing on individual trophic levels and not on cross-level interactions. Looking at traits not only within but across trophic levels and identifying traits that together define trophic interactions holds a great potential for understanding the mechanisms of interactions. Here, we outline the conceptual foundation for cross-trophic trait-based frameworks, using planktonic food webs as an example. First, we compile a list of traits important within different individual trophic levels and show that there are traits that are common across trophic levels ("universal" traits), as well as trophic level-specific traits. Next, we focus on traits that characterize interactions across trophic levels, focusing on two types of interaction-grazer-primary producer and host-parasite, identifying the similarities and differences between these interactions. We outline the trait hierarchies that define possible and realized intertrophic interactions and their strengths. We then highlight the importance of trade-offs among those traits in shaping interactions and explaining general patterns in the structure and function of food webs. Finally, we discuss the environmental influences on traits, their eco-evolutionary responses to changing conditions and how those responses may alter trophic interactions. The extension of trait-based approaches from individual trophic levels to food webs and different trophic interactions should stimulate further conceptual development, enrich the field of aquatic sciences, and provide a framework to better predict global change effects on ecosystems.

A complex interplay of environmental variables impacts phytoplankton community composition and physiology. Temperature and nutrient availability are two principal factors driving phytoplankton growth and composition, but are often investigated independently and on individual species in the laboratory. To assess the individual and interactive effects of temperature and nutrient concentration on phytoplankton community composition and physiology, we altered both the thermal and nutrient conditions of a cold-adapted spring phytoplankton community in Narragansett Bay, Rhode Island, when surface temperature was 2.6 degrees C and chlorophyll > 9 mu g L-1. Water was incubated in triplicate at -0.5 degrees C, 2.6 degrees C, and 6 degrees C for 10 d. At each temperature, treatments included both nutrient amendments (N, P, Si addition) and controls (no macronutrients added). The interactive effects of temperature and resource availability altered phytoplankton growth and community structure. Nutrient amendments resulted in species sorting and communities dominated by larger species. Under replete nutrients, warming tripled phytoplankton growth rates, but under in situ nutrient conditions, increased temperature acted antagonistically, reducing growth rates by as much as 33%, suggesting communities became nutrient limited. The temperature-nutrient interplay shifted the relative proportions of each species within the phytoplankton community, resulting in more silica rich cells at decreasing temperatures, irrespective of nutrients, and C : N that varied based on resource availability, with nutrient limitation inducing a 47% increase in C : N at increasing temperatures. Our results illustrate how the temperature-nutrient interplay can alter phytoplankton community dynamics, with changes in temperature amplifying or exacerbating the nutrient effect with implications for higher trophic levels and carbon flux.

Mathematica code for "A general framework for species-abundance distributions: linking traits and dispersal to explain commonness and rarity", Ecology Letters. Requires: Wolfram Mathematica (tested on v13.1) EcoEvo package (tested on v1.6.4) This research was supported by the Simons Foundation grant 343149, NSF grant DEB 17-54250 and NASA grant 80NSSC18K1084. Copyright: Creative Commons Attribution 4.0 International Open Access

The chromatin associated with the nuclear lamina (NL) is referred to as lamina-associated domains (LADs). Here, we present an adaptation of the tyramide-signal amplification sequencing (TSA-seq) protocol, which we call chromatin pull down-based TSA-seq (cTSA-seq), that can be used to map chromatin regions at or near the NL from as little as 50 000 cells. The cTSA-seq mapped regions are composed of previously defined LADs and smaller chromatin regions that fall within the Hi-C defined B-compartment containing nuclear peripheral heterochromatin. We used cTSA-seq to map chromatin at or near the assembling NL in cultured cells progressing through early G1. cTSA-seq revealed that the distal ends of chromosomes are near or at the reassembling NL during early G1, a feature similar to those found in senescent cells. We expand the use of cTSA-seq to the mapping of chromatin at or near the NL from fixed-frozen mouse cerebellar tissue sections. This mapping reveals a general conservation of NL-associated chromatin and identifies global and local changes during cerebellar development. The cTSA-seq method reported here is useful for analyzing chromatin at or near the NL from small numbers of cells derived from both in vitro and in vivo sources.

Our past GAPplanetS survey over the last 5 years with the MagAO visible AO system discovered the first examples of accreting protoplanets (by direct observation of H-alpha emission). Examples include LkCa15 b (Sallum et al. 2015) and PDS70 b (Wagner et al. 2018). In this paper we review the science performance of the newly (Dec. 2019) commissioned MagAO-X extreme AO system. In particular, we use the vAPP coronagraphic contrasts measured during MagAO-X first light. We use the Massive Accreting Gap (MAG) protoplanet model of Close 2020 to predict the H-alpha contrasts of 19 of the best transitional disk systems (ages 1-5 Myr) for the direct detection of H-alpha from accretion of hydrogen onto these protoplanets. The MAG protoplanet model applied to the observed first light MagAO-X contrasts predict a maximum yield of 46 +/- 7 planets from 19 stars (42 of these planets would be new discoveries). This suggests that there is a large, yet, unexplored reservoir of protoplanets that can be discovered with an extreme AO coronagraphic survey of 19 of the best transitional disk systems. Based on our first light contrasts we predict a healthy yield of protoplanets from our MaxProtoPlanetS survey of 19 transitional disks with MagAO-X.

Correlations between chemical and structural complexities of minerals were analysed using a total of 4962 datasets on the chemical compositions and 3989 datasets on the crystal structures of minerals. The amounts of structural and chemical Shannon information per atom and per unit cell or formula unit were calculated using the approach proposed by Krivovichev with no H-correction for the minerals with unknown H positions. Statistical analysis shows that there are strong and positive correlations (R-2 > 0.95) between the chemical and structural complexities and the number of different chemical elements in a mineral. Analysis of relations between chemical and structural complexities provides strong evidence that there is an overall trend of increasing structural complexity with the increasing chemical complexity. Following Hazen, four groups of minerals were considered that represent four eras of mineral evolution: "ur-minerals", minerals from chondritic meteorites, Hadean minerals, and minerals of the post-Hadean era. The analysis of mean chemical and structural complexities for the four groups demonstrate that both are gradually increasing in the course of mineral evolution. The increasing complexity follows an overall passive trend: more complex minerals form with the passage of geological time, yet the simpler ones are not replaced. The observed correlations between the chemical and structural complexities understood in terms of Shannon information suggest that, at a first approximation, chemical differentiation is a major force driving the increase of complexity of minerals in the course of geological time. New levels of complexity and diversification observed in mineral evolution are achieved through the chemical differentiation, which favours local concentrations of particular rare elements and creation of new geochemical environments.

Single-crystal X-ray diffraction data have been obtained for crystals of the F analog of superhydrous phase B, Mg10Si3O14F4. Twinned crystals were synthesized using a split-sphere anvil apparatus (USSA-2000) at pressures between 17.8 and 22.3 GPa and temperatures between 1450 and 1600 degrees C, Orthorhombic (space group Pnnm) unit-cell parameters are a = 5.050(3), b = 13.969(2), and c = 8.640(3) Angstrom. The substitution of F for H results in minor crystal chemical changes. Notably, average Mg-F distances (1.95 Angstrom) are shorter than the corresponding average of Mg-OH distances (1.98 Angstrom). These differences are reflected in shortening of unit-cell axes a and c in superfluorous B by 0.6 and 0.8%, respectively, relative to superhydrous B, while the b axis is unchanged. The close similarities between superhydrous and superfluorous B phases suggest that F will usually substitute for OH- in mantle phases.