The missing toxic link: Exposure of non-target native marsupials to second-generation anticoagulant rodenticides (SGARs) suggest a potential route of transfer into apex predators.

Anticoagulant rodenticides (ARs) are used globally to control rodent pests. Second-generation anticoagulant rodenticides (SGARs) persist in the liver and pose a significant risk of bioaccumulation and secondary poisoning in predators, including species that do not generally consume rodents. As such, there is a clear need to understand the consumption of ARs, particularly SGARs, by non-target consumers to determine the movement of these anticoagulants through ecosystems. We collected and analysed the livers from deceased common brushtail possums (Trichosurus vulpecula) and common ringtail possums (Pseudocheirus peregrinus), native Australian marsupials that constitute the main diet of the powerful owl (Ninox strenua), an Australian apex predator significantly exposed to SGAR poisoning. ARs were detected in 91 % of brushtail possums and 40 % of ringtail possums. Most of the detections were attributed to SGARs, while first-generation anticoagulant rodenticides (FGARs) were rarely detected. SGAR concentrations were likely lethal or toxic in 42 % of brushtail possums and 4 % of ringtail possums with no effect of age, sex, or weight detected in either species. There was also no effect of the landscape type possums were from, suggesting SGAR exposure is ubiquitous across landscapes. The rate of exposure detected in these possums provides insight into the pathway through which ARs are transferred to one of their key predators, the powerful owl. With SGARs entering food-webs through non-target species, the potential for bioaccumulation and broader secondary poisoning of predators is significantly greater and highlights an urgent need for routine rodenticide testing in non-target consumers that present as ill or found deceased. To limit their impact on ecosystem stability the use of SGARs should be significantly regulated by governing agencies.

Three-arm robotic cholecystectomy: a novel, cost-effective method of delivering and learning robotic surgery in upper GI surgery.

Cholecystectomy is one of the commonest performed surgeries worldwide. With the introduction of robotic surgery, the numbers of robot-assisted cholecystectomies has risen over the past decade. Despite the proven use of this procedure as a training operation for those surgeons adopting robotics, the consumable cost of routine robotic cholecystectomy can be difficult to justify in the absence of evidence favouring or disputing this approach. Here, we describe a novel method for performing a robot-assisted cholecystectomy using a "three-arm" technique on the newer, 4th generation, da Vinci system. Whilst maintaining the ability to perform precision dissection, this method reduces the consumable cost by 46%. The initial series of 109 procedures proves this procedure to be safe, feasible, trainable and time efficient.