Assessing the recovery of an Antarctic predator from historical exploitation

The recovery of whale populations from centuries of exploitation will have important management and ecological implications due to greater exposure to anthropogenic activities and increasing prey consumption. Here, a Bayesian population model integrates catch data, estimates of abundance, and information on genetics and biology to assess the recovery of western South Atlantic (WSA) humpback whales (Megaptera novaeangliae). Modelling scenarios evaluated the sensitivity of model outputs resulting from the use of different data, different model assumptions and uncertainty in catch allocation and in accounting for whales killed but not landed. A long period of exploitation drove WSA humpback whales to the brink of extinction. They declined from nearly 27 000 (95% PI = 22 800–33 000) individuals in 1830 to only 450 (95% PI = 200–1400) whales in the mid-1950s. Protection led to a strong recovery and the current population is estimated to be at 93% (95% PI = 73–100%) of its pre-exploitation size. The recovery of WSA humpback whales may result in large removals of their primary prey, the Antarctic krill (Euphausia superba), and has the potential to modify the community structure in their feeding grounds. Continued monitoring is needed to understand how these whales will respond to modern threats and to climate-driven changes to their habitats

Analysis of divergence between the axes of dental implants installed using a classic freehand technique

Accuracy is a common challenge in dental implant placement. A successful clinical outcome is largely determined by accurate positioning of the implant at the prepared site and proper angulation. This study aimed to compare the divergence between the axes of the implants installed using a classic freehand technique. Cartesian coordinates of implant necks were determined on the CT images of 34 patients in the XOY (horizontal) plane, followed by the coordinates of implant apices. The obtained data were submitted to the original software developed by the authors (patent 2018661716) that automatically computed an angle between the insertion axes of the installed implants. We found that in 87% of cases, this angle was significantly greater (up to 27°) than recommended by implantation dentistry guidelines (7°). In 100% of the studied cases, the implants were not parallel; in sector 1, the deviation was 27° 4`.</jats:p

Analysis of osseous tissue temperature during preparation of recipient bed for cylindrical implants

In the early 21st century, robot-assisted dental implant surgery became a popular alternative to classic implant placement protocols. Postoperative complications are often provoked by poor compliance with surgical guidelines for implant placement, resulting in the overheating of the osteotomy site. The aim of this study was to measure the temperature of osseous tissue at the dental implant site during classic and robot-assisted dental implant placement performed at different cooling modes. Avital skeletonized mandibles of Vietnamese pot-bellied pigs were used as an experimental model. The recipient bed was prepared following the classic surgical protocol. Three cooling modes were tested: no irrigation, irrigation with sterile saline at 25–30 ml/min and standard 75 ml/min irrigation recommended by the standard surgical protocol. The temperature of the isotonic solution was 25 °С. The study showed that both classic and robot-assisted dental implant placement techniques are safe if there is sufficient irrigation and good compliance with the surgical protocol.</jats:p