Aims: This study investigates the community structure and diversity of terrestrial soil bacterial communities thriving in four contrasting Köppen climatic zones of India using high-throughput sequencing. Methodology and results: Soil samples were collected for metagenomic DNA isolation and PCR amplification using primers targeting the 16S rRNA gene region. Amplicons were subjected to Oxford nanopore sequencing and data analysis. Bacterial species diversity, evenness and richness were highest in a humid sub-tropical climatic zone (HSCZ). Firmicutes were the most abundant phylum in the tropical wet climatic zone (TWCZ), arid climatic zone (ACZ) and humid sub-tropical climatic zone (HSCZ), while Proteobacteria in the mountain climatic zone (MCZ). The predominance of class Alphaproteobacteria, Actinobacteria with genera Bradyrhizobium, Chthoniobacter and Mycobacterium, was observed in MCZ in contrast to class Bacilli with genera Bacillus and Paenibacillus in the rest of the zones. OTU abundance was positively correlated with moisture, TOC (total organic carbon), K, MAP (mean annual precipitation) and negatively correlated with pH, Ca, N, B, Fe, P, Mg and MAT (mean annual temperature). A significant correlation was only observed with Fe against Shannon diversity (H’) in multiple regression analysis. Conclusion, significance and impact of study The multidirectional relationship between soil, its microbiota and climate is crucial in modulating bacterial community diversity and its survival in terrestrial ecosystems that significantly contribute to ecosystem function. This work mapped the occurrence and distribution of terrestrial soil bacterial communities in contrasting climatic zones for the first time, enabling us to assess the effect of climate in the mentioned Köppen climatic zones.

STUDY DESIGN: Retrospective review of an initial cohort of consecutive patients undergoing robot-assisted pedicle screw placement.PURPOSE: We aimed to evaluate the learning curve, if any, of this new technology over the course of our experience.OVERVIEW OF LITERATURE: Percutaneous pedicle screws have specific advantages over open freehand screws. However, they require intraoperative imaging for their placement (e.g., fluoroscopy and navigation) and require increased surgeon training and skill with the learning curve estimated at approximately 20–30 cases. To our knowledge, this is the first study that measures the learning curve of robot-guided purely percutaneous pedicle screw placement with comprehensive objective postoperative computed tomography (CT) scoring, time per screw placement, and fluoroscopy time.METHODS: We included the first 80 consecutive patients undergoing robot-assisted spinal surgery at Melbourne Private Hospital. Data were collected for pedicle screw placement accuracy, placement time, fluoroscopy time, and revision rate. Patient demographic and relevant perioperative and procedural data were also collected. The patients were divided equally into four sub-groups as per their chronological date of surgery to evaluate how the learning curve affected screw placement outcomes.RESULTS: Total 80 patients were included; 73 (91%) had complete data and postoperative CT imaging that could help assess that placement of 352 thoracolumbar pedicle screws. The rate of clinically acceptable screw placement was high (96.6%, 95.4%, 95.6%, and 90.7%, in groups 1 to 4, respectively, p=0.314) over time. The median time per screw was 7.0 minutes (6.5, 7.0, 6.0, and 6.0 minutes in groups 1 to 4, respectively, p=0.605). Intraoperative revision occurred in only 1 of the 352 screws (0.3%).CONCLUSIONS: We found that robot-assisted screw placement had high accuracy, low placement time, low fluoroscopy time, and a low complication rate. However, there were no significant differences in these parameters at the initial experience and the practiced, experience placement (after approximately 1 year), indicating that robot-assisted pedicle screw placement has a very short (almost no) learning curve.
Cohort Studies ; Fluoroscopy ; Hospitals, Private ; Humans ; Learning Curve ; Learning ; Pedicle Screws ; Retrospective Studies ; Robotic Surgical Procedures ; Spinal Fusion