Many spiders, and in particular those in the genus Argiope, spin highly visible web decorations whose function and significance are the subject of spirited debate. In this work, we present data to address two of the competing hypotheses that fuel this controversy. In particular, we examine the relationship between the presence of web decorations and spider survivorship (predator-protection hypo...

We consider proofs in minimal logic, written in natural deduction style. The only rules are introduction and elimination for implication and the universal quantifier. The logical connectives ∃,∧ are seen as special cases of inductively defined predicates, and hence are defined by the introduction and elimination schemes ∀x(A→ ∃xA), ∃xA→ ∀x(A→ B)→ B (x not free in B), A→ B → A ∧B, A ∧B → (A→ B →...

Abstract Contemporary peacekeeping operations carry out many disparate tasks, which has triggered a debate about “Christmas Tree mandates.” Did the UN Secretariat or Security Council drive this expansion? Using original data on nineteen missions, 1998–2014, article compares tasks recommended by to those mandated Council. It finds that two bodies expressed different preferences regarding nature,...

The unique, well-defined tubular structure of carbon nanotubes (CNTs) continues to attract interest. CNTs are fascinating materials for basic scientific research with the potential for several promising applications in catalysis, electronic devices and chemical biology. In recent years, many efforts have led to the development of versatile methods to modify CNTs to obtain derivatives with more ...