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Interspecific competition influences the composition of ecological communities. Species may differ in their needs for different resources, therefore resource availability may determine the outcome of interspecific interactions. Species often compete over food, shelter or both. When more than one resource is limited, different species may prioritize different resources. To determine the impact of resource availability on the competitive relationship between an invasive and a native species, we examined interactions between groups of the invasive Argentine ant (Linepithema humile) and the native odorous ant (Tapinoma sessile) over (1) food, (2) shelter or (3) both simultaneously. We further examined the mechanisms underlying the competitive relationship, asking whether aggressive interactions, exploratory behaviour or the order of arrival at a resource explained resource use. Shelter was preferred by both species when no competitors were present. In a competitive setting, L. humile groups controlled shelter through aggressive displacement but lost control over food due to investment of workers in the control of shelter. Thus, there are tradeoffs when competing over multiple resources and aggressive interactions allow invasive species to displace native species from a preferred resource. This article is part of the theme issue 'Intergroup conflict across taxa'.

Variation in individual behavior among group members impacts collective outcomes. The ability of both individuals and groups to outcompete others can determine access to resources. The invasive Argentine ant, Linepithema humile, dominates resources and displaces native species. To determine how access to resources by groups of L. humile is impacted by their behavioral composition, we first determined that L. humile workers consistently vary in aggressive behavior. We then asked if variation in aggression within a group influences the group's ability to access a resource in the presence of cues of a native species, Tapinoma sessile. We found that the behavioral composition of L. humile groups impacted the groups' collective response to cues of T. sessile. Group behavior was the result of mostly additive, rather than synergistic, combinations of the behaviors of the group members. The behavior of groups that contained 50% highly aggressive and 50% low-aggression individuals was similar to the average of the behaviors of groups of all highly aggressive and groups of all low-aggression individuals. Uncovering the mechanisms that allow social invasive species to dominate the ecological communities they invade can inform the mitigation of invasion.

This article provides an overview of the field of bioorthogonal chemistry and its advancements at Radboud University. Bioorthogonal chemistry involves conducting chemical reactions within a biological environment with high selectivity and compatibility. Radboud University has made significant contributions to this field, including the development of strained alkynes and the synthesis of bioorthogonal tools such as BCN and TCO. These tools have been applied in various areas such as chemical biology and materials science. The article also highlights the interdisciplinary nature of research at Radboud University and the importance of synthetic availability in bioorthogonal reagents. The text specifically discusses the use of VBAs in bioorthogonal chemistry, particularly in the IEDDA reaction with tetrazines. The authors found that introducing boronic acid substituents on linear alkenes improved their reactivity in the IEDDA reaction. They also observed that the reactivity of VBAs varied depending on the coordinating substituent on the tetrazine. The authors explored the potential of VBAs in click-to-release chemistry, protein modification, and drug delivery applications. The article emphasizes the collaborative efforts and interdisciplinary approach necessary for advancing bioorthogonal chemistry. [Extracted from the article]

Cyclic peptides offer many advantages compared to their linear counterparts, including prolonged stability within the biological environment and enhanced binding affinity. Typically, peptides are cyclized by forming an amide bond, either on‐resin or in solution, through extensive use of orthogonal protecting groups or chemoselective ligation strategies, respectively. Here, we show that the chemoselective tetrazine‐thiol exchange is a powerful tool for rapid in situ cyclization of peptides without the need for additional activation reagents or extensive protecting group reshuffling. The reaction between N‐terminal sulfide‐bearing unsymmetric tetrazines and internal cysteines occurs spontaneously within a mildly acidic environment (pH 6.5) and is of traceless nature. The rapidly available unsymmetric sulfide tetrazine building blocks can be incorporated on resin using standard solid‐phase peptide synthesis protocols and are orthogonal to trifluoroacetic acid cleavage conditions. The cyclized peptides display high stability, even when incubated with a large excess of free thiols. Due to its traceless and mild nature, we expect that the tetrazine‐thiol exchange will be of high value for the in situ formation of cyclic peptide libraries, thus being applicable in drug discovery and development. [ABSTRACT FROM AUTHOR]

We present here a joint experimental and computational study on the formation of benzothiazoles. Our investigation reveals a green protocol for accessing benzothiazoles from acyl chlorides using either water alongside a reducing agent as the reaction medium or in combination with stoichiometric amounts of a weak acid, instead of the harsh conditions and catalysts previously reported. Specifically, we show that a protic solvent, particularly water, enables the formation of 2‐substituted benzothiazoles from N‐acyl 1,2‐aminothiophenols already at room temperature, without the need for strong acids or metal catalysts. DFT Molecular Dynamics simulations coupled with advanced enhanced sampling techniques provide a clear understanding of the catalytic role of water. We demonstrate how bulk water – due to its extended network of hydrogen bonds and an efficient Grotthuss mechanism – provides a reaction path that strongly reduces the reaction barriers compared to aprotic environments, namely more than 80 kJ/mol for the first reaction step and 250 kJ/mol for the second. Finally, we discuss the influence of different aliphatic and aromatic substituents with varying electronic properties on chemical reactivity. Besides providing in‐depth mechanistic insights, we believe that our findings pave the way for a greener route toward an important class of bioactive molecules. [ABSTRACT FROM AUTHOR]

Since the first report that 1,2,4,5‐tetrazines undergo a bioorthogonal reaction with dienophiles in the form of an inverse electron‐demand Diels‐Alder reaction, the demand for high‐yielding synthetic approaches towards them grew steadily. Despite this significant interest, tetrazines were predominantly accessed via the Pinner synthesis or other Pinner‐like reactions, significantly limiting available substrates. In particular, the synthesis of unsymmetrically substituted s‐tetrazines for the selective conjugation to another species presented a major challenge. To tackle these challenges, new and innovative high‐yielding transformations have been developed to widen the scope of accessible symmetric and unsymmetric tetrazines. For instance, Ni(II), Zn(II), and sulphur‐catalysed reactions between two nitriles and hydrazine were developed, which provide access to a wide range of (un‐)symmetric aryl s‐tetrazines. Also, amidines and orthoesters give tetrazines with alkyl substituents, whereas the usage of CH2Cl2 yields valuable H‐monosubstituted tetrazines. Methods using thiocarbohydrazides, terminal fluoroolefins, oxetane esters, or tosyl hydrazones are among the recent additions. Due to the high interest in tetrazine click‐chemistry approaches, some of which reach beyond inverse electron‐demand Diels‐Alder reactions, we expect this overview of synthetic routes to aid the exploration for further applications of tetrazines. Ultimately, we hope to provide a guide for chemists and chemical biologists for accessing functional s‐tetrazines. [ABSTRACT FROM AUTHOR]

Elucidating the mechanisms underlying differentiation between populations is essential to our understanding of ecological and evolutionary processes. While social network analysis has yielded numerous insights in behavioral ecology in recent years, it has rarely been applied to questions about population differentiation. Here, we use social network analysis to assess the potential role of social behavior in the recent divergence between two three-spined stickleback ecotypes, "whites" and "commons". These ecotypes differ significantly in their social behavior and mating systems as adults, but it is unknown when or how differences in social behavior develop. We found that as juveniles, the white ecotype was bolder and more active than the common ecotype. Furthermore, while there was no evidence for assortative shoaling preferences, the two ecotypes differed in social network structure. Specifically, groups of the white ecotype had a lower clustering coefficient than groups of the common ecotype, suggesting that groups of the white ecotype were characterized by the formation of smaller subgroups, or "cliques". Interestingly, ecotypic differences in the clustering coefficient were not apparent in mixed groups composed of whites and commons. The formation of cliques could contribute to population divergence by restricting the social environment that individuals experience, potentially influencing future mating opportunities and preferences. These findings highlight the insights that social network analysis can offer into our understanding of population divergence and reproductive isolation. [ABSTRACT FROM AUTHOR]