The above oath is what every physician is bound to follow, but what happens in real practice is quite alarming. The so-called divine profession has lost its glory due to the intrusion of an evil namely ‘defensive medicine.’ Defensive medicine in simple words is departing from normal medical practice as a safeguard from litigation. It occurs when a medical practitioner performs treatment or proc...

Let Γ = (V,E) be a simple graph. For a nonempty set X ⊆ V , and a vertex v ∈ V , δX(v) denotes the number of neighbors v has in X. A nonempty set S ⊆ V is a defensive k-alliance in Γ = (V,E) if δS(v) ≥ δS̄(v)+k, ∀v ∈ S. A defensive k-alliance S is called global if it forms a dominating set. The global defensive k-alliance number of Γ, denoted by γ k(Γ), is the minimum cardinality of a defensive ...