Experimental and Theoretical Studies of Dimers Stabilized by Two Chalcogen Bonds in the Presence of a N···N Pnicogen Bond.

The structure of the 5,6-dichloro-2,1,3-benzoselenadiazole homodimer, obtained by adding the ligand, 4,5-dichloro--phenylenediamine, to the methanolic solution of SeCl, was determined by X-ray crystallography, augmented by Fourier transform infrared, Raman, and NMR spectroscopy. The binding motif involves a pair of Se···N chalcogen bonds, with a supplementary N···N pnicogen bond. Quantum calculations provide assessments of the strengths of the individual interactions as well as their contributing factors.

Epigallocatechin-3-Gallate (EGCG) Inhibits SARS-CoV-2 Infection in Primate Epithelial Cells: (A Short Communication).

SARS-CoV-2, the novel coronavirus responsible for the COVID-19 pandemic, caused >26 million cases in the United States and >437,000 deaths as of Jan 30, 2020. Worldwide by that date, there had been 102 million cases of infections, and deaths had climbed to 2.21 million.

Predicting greater sage-grouse habitat selection at the southern periphery of their range.

Mapping suitable habitat is an important process in wildlife conservation planning. Species distribution reflects habitat selection processes occurring across multiple spatio-temporal scales. Because habitat selection may be driven by different factors at different scales, conservation planners require information at the scale of the intervention to plan effective management actions.

Measuring the effect of environmental stress on inbreeding depression alone obscures the relative importance of inbreeding-stress interactions on overall fitness in .

Environmental stress can have a profound effect on inbreeding depression. Quantifying this effect is of particular importance in threatened populations, which are often simultaneously subject to both inbreeding and environmental stress. But while the prevalence of inbreeding-stress interactions is well known, the importance and broader applicability of such interactions in conservation are not clearly understood.

Using satellite-derived estimates of plant phenological rhythms to predict sage-grouse nesting chronology.

The "green wave" hypothesis posits that during spring consumers track spatial gradients in emergent vegetation and associated foraging opportunities. This idea has largely been invoked to explain animal migration patterns, yet the general phenomenon underlies trends in vertebrate reproductive chronology as well. We evaluated the utility of this hypothesis for predicting spatial variation in nest initiation of greater sage-grouse (), a species of conservation concern in western North America.

Contribution to the knowledge of the bumblebee fauna of Afghanistan (Hymenoptera, Apidae, Latreille).

Bumblebees (Hymenoptera: Apidae: genus Latreille, 1802) constitute an important group of pollinators for many wild plants and crops in north temperate regions and South America. Although knowledge of these insects has been increasing over the last decades, some geographic areas remain poorly studied and additions to the knowledge of their faunas are infrequent. Afghanistan is one example of a country that is currently underrepresented in the scientific literature despite its high species diversity.

A missed research opportunity for effective prevention: Clery Act Timely Warning Notices.

The Clery Act was created to provide transparency around campus safety, including sexual assault. This includes making timely warnings to the campus community about safety threats on campus. While all universities are mandated to follow the Clery Act, the legislation does not provide guidance on what language universities should employ, how much leeway an institution has in determining if a sexual assault represents an immediate public safety threat, or recommended best practices for Timely Warning Notices.

Versatility of the Cyano Group in Intermolecular Interactions.

Several cyano groups are added to an alkane, alkene, and alkyne group so as to construct a Lewis acid molecule with a positive region of electrostatic potential in the area adjoining these substituents. Although each individual cyano group produces only a weak π-hole, when two or more such groups are properly situated, they can pool their π-holes into one much more intense positive region that is located midway between them. A NH base is attracted to this site, where it forms a strong noncovalent bond to the Lewis acid, amounting to as much as 13.

Small differences in root distributions allow resource niche partitioning.

Deep roots have long been thought to allow trees to coexist with shallow-rooted grasses. However, data demonstrating how root distributions affect water uptake and niche partitioning are uncommon.We describe tree and grass root distributions using a depth-specific tracer experiment six times over two years in a subtropical savanna, Kruger National Park, South Africa.

Surveys in northern Utah for egg parasitoids of (Stål) (Hemiptera: Pentatomidae) detect (Ashmead) (Hymenoptera: Scelionidae).

The highly polyphagous and invasive brown marmorated stink bug, (Stål) (Hemiptera: Pentatomidae), has become a significant insect pest in North America since its detection in 1996. It was first documented in northern Utah in 2012 and reports of urban nuisance problems and plant damage have since increased. Biological control is the preferred solution to managing in North America and other invaded regions due to its alignment with integrated pest management and sustainable practices.

Noncovalent Bonds between Tetrel Atoms.

The pairing of TFH with a TH CH anion, where T represents tetrel atoms C, Si, Ge, Sn, Pb, results in a strong direct interaction between the two T atoms. The interaction energy is sensitive to the nature of the two T atoms but can be as large as 90 kcal/mol. The noncovalent bond strength rises quickly as the basic T atom of the anion becomes smaller, or as the Lewis acid T grows larger, although there is less sensitivity to the latter atom.

The geographic mosaic of arms race coevolution is closely matched to prey population structure.

Reciprocal adaptation is the hallmark of arms race coevolution. Local coadaptation between natural enemies should generate a geographic mosaic pattern where both species have roughly matched abilities across their shared range. However, mosaic variation in ecologically relevant traits can also arise from processes unrelated to reciprocal selection, such as population structure or local environmental conditions.

The ditetrel bond: noncovalent bond between neutral tetrel atoms.

The ability of a tetrel atom to serve in the capacity of electron donor in a σ-hole noncovalent bond is tested by quantum calculations. The donor molecule TMH contains a metal atom M on a tetravalent tetrel (T) atom, with M = Li, Na, K so as to generate a partial negative charged region on T. The F atom of the Lewis acid HFT molecule facilitates the formation of a positive σ-hole on the acid T atom.

Genotyping-by-sequencing and ecological niche modeling illuminate phylogeography, admixture, and Pleistocene range dynamics in quaking aspen ().

is the widest-ranging tree species in North America and an ecologically important component of mesic forest ecosystems displaced by the Pleistocene glaciations. Using phylogeographic analyses of genome-wide SNPs (34,796 SNPs, 183 individuals) and ecological niche modeling, we inferred population structure, ploidy levels, admixture, and Pleistocene range dynamics of , and tested several historical biogeographical hypotheses. We found three genetic lineages located mainly in coastal-Cascades (cluster 1), east-slope Cascades-Sierra Nevadas-Northern Rockies (cluster 2), and U.

Caterpillars on a phytochemical landscape: The case of alfalfa and the Melissa blue butterfly.

Modern metabolomic approaches that generate more comprehensive phytochemical profiles than were previously available are providing new opportunities for understanding plant-animal interactions. Specifically, we can characterize the phytochemical landscape by asking how a larger number of individual compounds affect herbivores and how compounds covary among plants. Here we use the recent colonization of alfalfa () by the Melissa blue butterfly () to investigate the effects of indivdiual compounds and suites of covarying phytochemicals on caterpillar performance.

Low-cost observations and experiments return a high value in plant phenology research.

Plant ecologists in the Anthropocene are tasked with documenting, interpreting, and predicting how plants respond to environmental change. Phenology, the timing of seasonal biological events including leaf-out, flowering, fruiting, and leaf senescence, is among the most visible and oft-recorded facets of plant ecology. Climate-driven shifts in plant phenology can alter reproductive success, interspecific competition, and trophic interactions.

Functional traits explain amphibian distribution in the Brazilian Atlantic Forest.

Aim: Species distributions are one of the most important ways to understand how communities interact through macroecological relationships. The functional abilities of a species, such as its plasticity in various environments, can determine its distribution, species richness and beta diversity patterns. In this study, we evaluate how functional traits influence the distribution of amphibians, and hypothesize which functional traits explain the current pattern of amphibian species composition.

Anion⋅⋅⋅Anion Attraction in Complexes of MCl (M=Zn, Cd, Hg) with CN.

High-level ab initio calculations show that the MCl anions comprising Group 2B M atoms Zn, Cd, and Hg form a stable complex with the CN anion, despite the like charge of the two ions. The complexation occurs despite a negative π-hole region above the M atom of MCl . The dimerization distorts the planar geometry of MCl into a pyramidal shape which reduces the negative potential above the M atom, facilitating a close approach of the two anions, with R(M⋅⋅⋅C)∼2 Å, and an overall attractive electrostatic attraction within the dimer.

Postmagmatic Tectonic Evolution of the Outer Izu-Bonin Forearc Revealed by Sediment Basin Structure and Vein Microstructure Analysis: Implications for a 15 Ma Hiatus Between Pacific Plate Subduction Initiation and Forearc Extension.

International Ocean Discovery Program Expedition 352 recovered sedimentary-volcaniclastic successions and extensional structures (faults and extensional veins) that allow the reconstruction of the Izu-Bonin forearc tectonic evolution using a combination of shipboard core data, seismic reflection images, and calcite vein microstructure analysis. The oldest recorded biostratigraphic ages within fault-bounded sedimentary basins (Late Eocene to Early Oligocene) imply a ~15 Ma hiatus between the formation of the igneous basement (52 to 50 Ma) and the onset of sedimentation. At the upslope sites (U1439 and U1442) extension led to the formation of asymmetric basins reflecting regional stretch of ~16-19% at strain rates of ~1.

Food availability modulates temperature-dependent effects on growth, reproduction, and survival in .

Reduced body size and accelerated life cycle due to warming are considered major ecological responses to climate change with fitness costs at the individual level. Surprisingly, we know little about how relevant ecological factors can alter these life history trade-offs and their consequences for individual fitness. Here, we show that food modulates temperature-dependent effects on body size in the water flea and interacts with temperature to affect life history parameters.

Density-dependent space use affects interpretation of camera trap detection rates.

Camera traps (CTs) are an increasingly popular tool for wildlife survey and monitoring. Estimating relative abundance in unmarked species is often done using detection rate as an index of relative abundance, which assumes that detection rate has a positive linear relationship with true abundance. This assumption may be violated if movement behavior varies with density, but the degree to which movement behavior is density-dependent across taxa is unclear.

Invasive management outcomes and native plant recovery are context dependent.

The outcomes of invasive plant removal efforts are influenced by management decisions, but are also contingent on the uncontrolled spatial and temporal context of management areas. is an aggressive invader that is intensively managed in wetlands across North America. Treatment options have been understudied, and the ecological contingencies of management outcomes are poorly understood.

Evolutionary constraint on low elevation range expansion: Defense-abiotic stress-tolerance trade-off in crosses of the ecological model .

Most transplant experiments across species geographic range boundaries indicate that adaptation to stressful environments outside the range is often constrained. However, the mechanisms of these constraints remain poorly understood. We used extended generation crosses from diverged high and low elevation populations.

Chalcogen bonding of two ligands to hypervalent YF (Y = S, Se, Te, Po).

The ability of two NH ligands to engage in simultaneous chalcogen bonds to a hypervalent YF molecule, with Y = S, Se, Te, Po, is assessed via quantum calculations. The complex can take on one of two different geometries. The cis structure places the two ligands adjacent to one another in a pseudo-octahedral geometry, held there by a pair of σ-hole chalcogen bonds.

Function and Transcriptional Regulation of Bovine Gene in Adipocytes: Roles of , , and .

The TORC2 gene is a member of the transducer of the regulated cyclic adenosine monophosphate (cAMP) response element binding protein gene family, which plays a key role in metabolism and adipogenesis. In the present study, we confirmed the role of in bovine preadipocyte proliferation through cell cycle staining flow cytometry, cell counting assay, 5-ethynyl-2'-deoxyuridine staining (EdU), and mRNA and protein expression analysis of proliferation-related marker genes. In addition, Oil red O staining analysis, immunofluorescence of adiponectin, mRNA and protein level expression of lipid related marker genes confirmed the role of in the regulation of bovine adipocyte differentiation.