Performance evaluation and enhancement of Dendro

DENDRO is a collection of tools for solving Finite Element problems in parallel. This package is written in C++ using the standard template library (STL) and uses the Message Passing (MPI). Dendro uses an octree data-structure to solve image-registration problems using finite element techniques. For analyzing the behavior of the package in terms of speed-up and scalability, it is important to know which part of the package is consuming most of the execution-time. The single node performance and the overall performance of the package is dependent on the code-organization and class-hierarchy. We used the PETSC profiler to collect the performance statistics and instrument the code to know which part of the code takes most of the time. Along with the function-specific execution timings, PETSC profiler also provides the information regarding how many floating point operations is being performed in total and on average (FLOP/second). PETSC also provides information related to memory usage and number of MPI messages and reductions being performed to execute that particular function. We have analyzed these performance-statistics to provide some guidelines to how we can make Dendro more efficient by optimizing certain functions. We obtained around 12X speedup over the performance of (default) Dendro by using compiler-provided optimizations and achieved more than 65% speedup over compiler optimized performance (20X over the naive Dendro performance) by manually tuning some-block of code along with the compiler-optimizations

Clinical outcome of primary cemented hemiarthroplasty in unstable trochanteric fractues in elderly patients

Background: Management of unstable trochanteric fracture in elderly patients is challenging due to poor bone quality. Fracture stabilization and early mobilization is very important in preventing the complications. Fixation of the fracture with proximal femoral nail and dynamic hip screw has its complication and it takes time to mobilization of the patient after consolidation of fracture. Cemented bipolar hemiarthroplasty in osteoporotic unstable comminuted trochanteric fracture helps in early mobility and reduces complications.Methods: We prospectively analyzed 20 cases of cemented hemiarthroplasty in unstable intertrochanteric fractures. The functional outcomes were assessed based by Harris hip score.Results: The functional outcome measured with Harris hip score is excellent to good in most of the patients.Conclusions: Primary cemented hemiarthroplasty in unstable trochanteric fracture in elderly results in early ambulation with good functional outcome

Spatial mode dynamics in wide-aperture quantum-dot lasers

We present a systematic theoretical study of spatial mode dynamics in wide-aperture semiconductor quantum-dot lasers within the Maxwell-Bloch formalism. Our opto-electro-thermal model self-consistently captures the essential dynamical coupling between field, polarization, and carrier density in both thermal and nonthermal regimes, providing detailed description of the complex spatiotemporal modal intensity structure and spectra in these novel devices and broad area edge-emitting lasers in general. Using linear stability analysis and high resolution adaptive-grid finite element numerical simulation, we show that in the nonthermal regime, the presence of inhomogeneous broadening in quantum-dot active media leads to suppressed filamentation and enhanced spatial coherence compared to conventional quantum well devices with comparable phase-amplitude coupling (alpha parameter). Increasing the degree of inhomogeneous broadening in the active medium leads to further improvement in spatial coherence. In the thermal regime, there is further suppression of filamentation in the inhomogeneously broadened quantum-dot active medium; however, the spatial coherence aided by inhomogeneous broadening is partly lost due to the effect of temperature on cavity detuning. We propose that device designs based on optimized inhomogeneous broadening of quantum-dot gain medium could ultimately lead to diffraction-limited outputs in the quasi-cw regime which are still very difficult to achieve in conventional wide-aperture designs

A study to evaluate the pattern of microorganisms causing early post-operative wound infection in patients undergoing orthopaedic surgery with implant for closed fracture or disease in medical college and hospital, Kolkata

Background: For all orthopaedic surgical procedures with implant, infection at the operative site has always been recognized as a potential complication. The present study was done to evaluate the pattern of causative microorganisms in post-operative infection after orthopaedic surgery with implant in Medical College and Hospital, Kolkata.Methods: This study was Institution based cross-sectional observational case study. Patients population were selected from the patients, who were admitted or came for follow up in the Department of Orthopaedics, who had undergone surgery with implant for close fracture and disease and developed early (<3 months) post-operative wound infection The samples were collected and were sent to the Department of Microbiology, Medical College & Hospital, Kolkata for isolation and identification of the microorganisms and their antimicrobial susceptibility were done.Results: Maximum infections were detected and wound swabs were sent for culture in 2nd week of surgery followed by 3rd week. Only 10% (8 cases) had infection beyond 8 weeks. Plates with screws were used in 37 cases (46%) and nails in 15 cases (19%). It was been seen that infection in case of hip prosthesis were significant that is 8% (6 cases) which included four cases of hemiarthroplasty and two cases of total hip arthroplasty.Conclusions: The data suggests that there is preponderance of Gram- negative infections in operated orthopaedic patients, but Staphylococcus aureus predominates the infectious agents as the sole pathogen. Klebsiella species and pseudomonas species are second and third most common pathogens respectively