Effectiveness of simulation technique in teaching-learning process for prevention of postpartum hemorrhage in obstetrics and gynecology

Background: Simulation involves creation of artificial depiction of clinical situations which are rarely encountered. Objectives of the study to evaluate efficacy of simulation in teaching learning process for prevention of postpartum hemorrhage amongst postgraduates of Obstetrics Gynecology department.Methods: Prospective study was conducted in Obstetrics Gynecology department of rural tertiary centre of Northern India over 6 months. Twenty one postgraduates of Obstetrics Gynecology department were randomly assigned to either simulation teaching using mannequin / didactic lecture on Active Management of Third Stage of Labor, ten students in each group (one dropped out). Efficacy of each teaching learning method was compared using multiple choice questionnaires: pre-teaching, post-teaching, Direct Observation of Procedural Skills (DOPS) encounter using structured checklist. Student satisfaction was evaluated using feedback questionnaire. Statistical analysis was done by Mann-Whitney test using SPSS-20 software.Results: Both groups showed no difference in performance of pretest MCQ. Comparison of DOPS performance showed, significant difference (p=0.0003) between simulation and didactic lecture group (mean marks 5.20±0.79 in Group 1 and 3.20±1.63 in Group 2). Both groups demonstrated significant improvement in post-teaching, but on comparison of post-test MCQ with pretest marks, significant difference was noted with mean difference of 7.80±1.76 in Group 1, 3.60±1.98 in Group 2, with greater improvement observed among simulation group. Students ranked simulation higher with regard to enjoyment (80%), interest (75%), relevance (75%), understanding (70%) and accessibility to ask questions (80%).Conclusions: Simulation based teaching is better than didactic lecture as teaching learning modality especially for critical care procedures

Thermal management and electromechanical noise suppression in a portable josephson junction voltage standard

A self-contained, fully portable, Josephson junction voltage reference standard system has been designed, developed and tested. The system relies on an active, closed-cycle refrigerator (CCR) cryocooler system and completely eliminates the reliance on liquid helium for cooling the Josephson Junction Array (JJA) chip to the required superconducting temperature of approximately to 4.2 K. The CCR based system has performance capabilities comparable to the liquid helium Dewar-based system and is packaged to operate as a portable system in environments like the US Army's calibration vans or calibration labs that do not have access to liquid helium. The use of a CCR based cryocooling system brings forth many challenges not found in the classic Dewar-based system. This work identifies the principal challenges for achieving an operating system, and provides unique solutions to overcoming two areas of significant concern, thermal management and electromagnetic noise. Dewar based systems provide three-dimensional convective cooling. While very effective in cooling, they are inappropriate for portable labs and are subject to evaporation. The challenge for an active system is in providing adequate thermal management to ensure sufficient cooling despite having only one-dimensional conductive cooling. An extensive study was conducted into various methodologies for mounting the chip in the new system and ensuring that superconducting temperatures were obtained. The surface roughness of a conventional machined surface is in the range of several micrometers. The random peaks and valleys of the surface offer insufficient contact area between the cryocooler cold-head and the Josephson junction array chip, resulting in higher than superconducting temperatures at the JJA chip surface. Several approaches researched to increase the thermal contact conductance included thermal grease, adhesives and other high conductivity interstitial materials. The solution provided in this research is an elegantly simple technique, which eliminated the introduction of viscous materials or adhesives, thereby improving the maintainability of the chip. An innovative chip-mount was designed and machined using a state-of-the-art diamond turning technique to achieve a surface roughness of lower than 5 nm and completely eliminate the use of any foreign material. The diamond turned surface attained an operational temperature of 4.2 ± 0.2 K indicating a 30% improvement in the ability to cool the JJA chip. The second area of interest is understanding the presence of magnetic fields and electromagnetic noise in the vicinity of the JJA chip and eliminating or greatly reducing them. High permeability MuMetal® magnetic shields were designed and installed to reduce the presence of magnetic field by up to 90%, and the nature of magnetic field noises were experimentally quantified. Performance deterioration due to the presence of electromagnetic noise induced by the cryocooler, motor and pump was expected, but for the first time detailed experiments were conducted to measure the magnetic fields in the system, understand their effects, and systematically eliminate or reduce them

Deep Learning Based Forecasting of Indian Summer Monsoon Rainfall

Accurate short range weather forecasting has significant implications for various sectors. Machine learning based approaches, e.g., deep learning, have gained popularity in this domain where the existing numerical weather prediction (NWP) models still have modest skill after a few days. Here we use a ConvLSTM network to develop a deep learning model for precipitation forecasting. The crux of the idea is to develop a forecasting model which involves convolution based feature selection and uses long term memory in the meteorological fields in conjunction with gradient based learning algorithm. Prior to using the input data, we explore various techniques to overcome dataset difficulties. We follow a strategic approach to deal with missing values and discuss the models fidelity to capture realistic precipitation. The model resolution used is (25 km). A comparison between 5 years of predicted data and corresponding observational records for 2 days lead time forecast show correlation coefficients of 0.67 and 0.42 for lead day 1 and 2 respectively. The patterns indicate higher correlation over the Western Ghats and Monsoon trough region (0.8 and 0.6 for lead day 1 and 2 respectively). Further, the model performance is evaluated based on skill scores, Mean Square Error, correlation coefficient and ROC curves. This study demonstrates that the adopted deep learning approach based only on a single precipitation variable, has a reasonable skill in the short range. Incorporating multivariable based deep learning has the potential to match or even better the short range precipitation forecasts based on the state of the art NWP models.Comment: 14 pages, 14 figures. The manuscript is under review with journal 'Transactions on Geoscience and Remote Sensing

Identification of H3K4me1-associated proteins at mammalian enhancers.

Enhancers act to regulate cell-type-specific gene expression by facilitating the transcription of target genes. In mammalian cells, active or primed enhancers are commonly marked by monomethylation of histone H3 at lysine 4 (H3K4me1) in a cell-type-specific manner. Whether and how this histone modification regulates enhancer-dependent transcription programs in mammals is unclear. In this study, we conducted SILAC mass spectrometry experiments with mononucleosomes and identified multiple H3K4me1-associated proteins, including many involved in chromatin remodeling. We demonstrate that H3K4me1 augments association of the chromatin-remodeling complex BAF to enhancers in vivo and that, in vitro, H3K4me1-marked nucleosomes are more efficiently remodeled by the BAF complex. Crystal structures of the BAF component BAF45C indicate that monomethylation, but not trimethylation, is accommodated by BAF45C's H3K4-binding site. Our results suggest that H3K4me1 has an active role at enhancers by facilitating binding of the BAF complex and possibly other chromatin regulators

Chlamydia

https://digitalcommons.imsa.edu/hd_graphic_novels/1020/thumbnail.jp

The Molecular Basis of Monopolin Recruitment to the Kinetochore

The monopolin complex is a multifunctional molecular crosslinker, which in S. pombe binds and organises mitotic kinetochores to prevent aberrant kinetochore-microtubule interactions. In the budding yeast S. cerevisiae, whose kinetochores bind a single microtubule, the monopolin complex crosslinks and mono-orients sister kinetochores in meiosis I, enabling the biorientation and segregation of homologs. Here, we show that both the monopolin complex subunit Csm1 and its binding site on the kinetochore protein Dsn1 are broadly distributed throughout eukaryotes, suggesting a conserved role in kinetochore organisation and function. We find that budding yeast Csm1 binds two conserved motifs in Dsn1, one (termed Box 1) representing the ancestral, widely conserved monopolin binding motif and a second (termed Box 2-3) with a likely role in enforcing specificity of sister kinetochore crosslinking. We find that Box 1 and Box 2-3 bind the same conserved hydrophobic cavity on Csm1, suggesting competition or handoff between these motifs. Using structure-based mutants, we also find that both Box 1 and Box 2-3 are critical for monopolin function in meiosis. We identify two conserved serine residues in Box 2-3 that are phosphorylated in meiosis and whose mutation to aspartate stabilises Csm1-Dsn1 binding, suggesting that regulated phosphorylation of these residues may play a role in sister kinetochore crosslinking specificity. Overall, our results reveal the monopolin complex as a broadly conserved kinetochore organiser in eukaryotes, which budding yeast have co-opted to mediate sister kinetochore crosslinking through the addition of a second, regulatable monopolin binding interface

Thermal management and electromechanical noise suppression in a portable josephson junction voltage standard

A self-contained, fully portable, Josephson junction voltage reference standard system has been designed, developed and tested. The system relies on an active, closed-cycle refrigerator (CCR) cryocooler system and completely eliminates the reliance on liquid helium for cooling the Josephson Junction Array (JJA) chip to the required superconducting temperature of approximately to 4.2 K. The CCR based system has performance capabilities comparable to the liquid helium Dewar-based system and is packaged to operate as a portable system in environments like the US Army's calibration vans or calibration labs that do not have access to liquid helium. The use of a CCR based cryocooling system brings forth many challenges not found in the classic Dewar-based system. This work identifies the principal challenges for achieving an operating system, and provides unique solutions to overcoming two areas of significant concern, thermal management and electromagnetic noise. Dewar based systems provide three-dimensional convective cooling. While very effective in cooling, they are inappropriate for portable labs and are subject to evaporation. The challenge for an active system is in providing adequate thermal management to ensure sufficient cooling despite having only one-dimensional conductive cooling. An extensive study was conducted into various methodologies for mounting the chip in the new system and ensuring that superconducting temperatures were obtained. The surface roughness of a conventional machined surface is in the range of several micrometers. The random peaks and valleys of the surface offer insufficient contact area between the cryocooler cold-head and the Josephson junction array chip, resulting in higher than superconducting temperatures at the JJA chip surface. Several approaches researched to increase the thermal contact conductance included thermal grease, adhesives and other high conductivity interstitial materials. The solution provided in this research is an elegantly simple technique, which eliminated the introduction of viscous materials or adhesives, thereby improving the maintainability of the chip. An innovative chip-mount was designed and machined using a state-of-the-art diamond turning technique to achieve a surface roughness of lower than 5 nm and completely eliminate the use of any foreign material. The diamond turned surface attained an operational temperature of 4.2 ± 0.2 K indicating a 30% improvement in the ability to cool the JJA chip. The second area of interest is understanding the presence of magnetic fields and electromagnetic noise in the vicinity of the JJA chip and eliminating or greatly reducing them. High permeability MuMetal® magnetic shields were designed and installed to reduce the presence of magnetic field by up to 90%, and the nature of magnetic field noises were experimentally quantified. Performance deterioration due to the presence of electromagnetic noise induced by the cryocooler, motor and pump was expected, but for the first time detailed experiments were conducted to measure the magnetic fields in the system, understand their effects, and systematically eliminate or reduce them. The final system was assembled and the performance was verified using standard Josephson voltage standard (JVS) system practices. A comparison of different operational parameters for the CCR based system was done with the laboratory based liquid helium cooling system, and the results were found to be comparable. The values for critical current and the step amplitude for the JJA chip (# 2629B11) were reported by the chip manufacturer to be 110 &mgr;A and 29 &mgr;A, respectively, tested with a liquid helium system; the same values were measured to be 112 &mgr;A and 27 &mgr;A, respectively, while operating in the UNC-Charlotte JVS system. The measured values were within the experimental repeatability of 5% and the nature of characteristic I-V curves and voltage steps were similar to the measurements made in the liquid helium system. These comparisons demonstrated the operational capabilities of the UNC-Charlotte CCR based Josephson voltage standard system