Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Automating Cloud Security Governance

Adopting cloud infrastructure in a large scale is a challenging proposition for companies. One of the key challenges is adopting the organization's existing infrastructure and security governance to the cloud operations. Scalability, agility and distributed computing are inherent properties of cloud infrastructure. These precisely are the challenges faced on governing cloud security. Existing procedures that depended on manual intervention are not feasible when the infrastructure is almost infinitely (compared to human resources at disposal) scalable. Parts of the infrastructure can change abruptly within minutes. How does one deploy audit processes with such agile infrastructure? What if the infrastructure changes even before the audit is complete? How to provide security assurance to higher management while following rapidrelease cycles in DevOps mode? This project is a series of governance learnings, tools prototyping and experimentation done on job. Infrastructure governance policies, procedures and tools were created specifically for the cloud. Parts of the cloud infrastructure such as the OS were customized to meet the governance policies. Asset and identity management were achieved by centralizing cloud service accounts. This enabled a central team to use cloud APIs to manage assets and users. Automated tools were deployed centrally to audit cloud assets and user accounts for security issues. The results strongly indicate that security automation and self-certification are key components of security governance of cloud and DevOps

Ultrasound-guided versus Conventional Caudal Blocks in Children: A Randomised Clinical Study

Introduction: Caudal epidural block is a popular regional anesthetic technique in children undergoing infraumbilical surgeries. Conventionally, a landmark-guided method is used to perform caudal epidural blocks. Although widely practiced, this method is associated with procedural difficulties such as multiple attempts, decreased success rates at the first puncture, as well as higher rates of complications including dural puncture, rectal injury, and intraosseous/intravenous (i.v.)/subcutaneous injections. In order to overcome the shortcomings of the conventional technique, various other methods have been described in clinical practice, including imaging-assisted techniques with fluoroscopy and Ultrasound (US). Aim: To compare the overall block success rates between the conventional and US-guided methods of caudal blocks in children. Materials and Methods: The present randomised clinical study was conducted in the Department of Anesthesiology, St. John's Medical College, Bengaluru, Karnataka, India, from November 2019 to September 2021. Sixty-four children, aged 1-8 years, belonging to the American Society of Anesthesiologists (ASA) physical status grade I and II, and undergoing elective inguinal hernial surgery were included in the study. After induction of general anesthesia, the children were administered caudal blocks based on the assigned groups: group A (conventional) - patients were given 0.5 mL/kg of 0.25% bupivacaine after the needle entered the sacral canal, and group B (USG) - patients were given 0.5 mL/kg of 0.25% bupivacaine immediately after the needle was visualised piercing the sacrococcygeal ligament in the longitudinal view. The parameters studied were overall block success rates, block performance times, and the number of attempts taken. Descriptive statistics were reported using mean±Standard Deviation (SD) for continuous variables and number or percentage for categorical variables. Independent t-test and Mann-Whitney U test were used for normally distributed and non-normally distributed variables, respectively. Chi-square test was used to analyse differences between categorical variables. Results: A total of 64 children of both genders, aged 1-8 years, belonging to ASA physical status I and II, were included in the study. Overall block success rates were comparable between the two groups, with 28 (87.5%) in group A and 30 (93.8%) in group B. The mean block performance time was longer in group B (2.781±1.2439 minutes) compared to group A (1.578±0.5835 minutes) (p-value<0.001). The number of attempts was lower in group B, with 100% success in the first attempt, as opposed to 68.8% in group A (p-value<0.05). Conclusion: Ultrasound-guided caudal block does not improve overall block success rates or block performance time, but it does improve success rates at the first attempt and thereby reduces the number of attempts

Performance analysis and enhancement of brain emotion-based intelligent controller and its impact on PMBLDC motor drive for electric vehicle applications

Growing awareness of electric vehicles insists on the necessity of Permanent Magnet Brushless Direct Current Motor (PMBLDCM) worldwide. This paper involves building a simulation model of the complete PMBLDCM drive system using Matlab/Simulink to control the speed and Torque. Using the Simulink model, speed parameters with various controllers of the drive system are studied and analyzed. The conventional PI controller is capable of controlling the speed of the PMBLDC motor. H1owever, it cannot give assurance of the stability of the motor throughout the load variation. In a speed loop, Improved Brain Emotional Learning Based Intelligent Controller (IBELBIC) is proposed in this paper. The proposed IBELBIC-based PMBLDC motor drive system with a rating of 3 phase, 30 V, 400 W, 3000 RPM is implemented using Spartan 3 Field Programmable Gate Array (FPGA) from Xilinx. This paper presents an IBELBIC design for enhancing the speed performance of the drive system at various set speeds and different load conditions of 1.2 Nm load, 0.6 Nm load, and no load. The proposed PMBLDCM drive system is realized with the help of a Very high speed integrated circuit Hardware Description Language (VHDL) programming algorithm of digital Pulse Width Modulation (PWM) generator topology. Various test cases are evaluated under different operating conditions to demonstrate the learning capability and the applicability of the proposed controller. In this paper, simulation validation is done using hardware setup, and experimental results are monitored on a computer using a customized program developed using LabVIEW (Laboratory Virtual Instrumentation Engineering Workbench). Instead of a Data Acquisition (DAQ) card, the Virtual Instrument Software Architecture (VISA) tool of LabVIEW software is used in this work and results in cost minimization of the experimental setup.Scopu