5,221 research outputs found
Studies on the Insecticidal and Repellent Properties of the Seed Extract of Tephrosia Purpurea (LINN) Pers
Laboratory and field trials were conducted to find out the insecticidal and repellent properties of petroleum ether extract of the seeds of Tephrosia purpurea. In laboratory trials contact toxicity of the extract was assessed against land leeches, houseflies, mosquitoes, rice weevil and flour beetle. In field trials, the repellency of the extract was assessed against land leeches, mosquitoes and simulium flies. In laboratory trials, the dosage required for 100 per cent mortality was 0.0005 gm/cm/sup 2/ for land leeches, 0.0157 gm/cm/sup 2/ for flour beetle. In field trials, the extract was found to be repellent against land leeches for 5 hours, mosquitoes for 4 hours and simulium flies for 5 hours
Robotic control of the seven-degree-of-freedom NASA laboratory telerobotic manipulator
A computationally efficient robotic control scheme for the NASA Laboratory Telerobotic Manipulator (LTM) is presented. This scheme utilizes the redundancy of the seven-degree-of-freedom LTM to avoid joint limits and singularities. An analysis to determine singular configurations is presented. Performance criteria are determined based on the joint limits and singularity analysis. The control scheme is developed in the framework of resolved rate control using the gradient projection method, and it does not require the generalized inverse of the Jacobian. An efficient formulation for determining the joint velocities of the LTM is obtained. This control scheme is well suited for real-time implementation, which is essential if the end-effector trajectory is continuously modified based on sensory feedback. Implementation of this scheme on a Motorola 68020 VME bus-based controller of the LTM is in progress. Simulation results demonstrating the redundancy utilization in the robotic mode are presented
Geochemistry of some ferruginous soils of Kerala, India
The four representative ferruginous soils on lateritic cover developed over Precambrian rocks in parts of Kottayam of Kerala were studied to understand the weathering pattern and genesis through geochemistry. These soils are strongly to moderately acidic, reddish brown with low Cation exchange capacity CEC and base saturation having SiO2 - 33 to 57%, Al2O3 - 16-31%, Fe2O3 - 8 to 15% and TiO2 -0.7 to 1.4%. Kanjirapalli (P3) and Athirampuzha (P4) soil series were more intensely weathered as compared to the Kinalur (P1) and Chingavanam series (P2) with silica to alumina -iron ratio less than 2 and had a significant negative relationship with Chemical index of alteration CIA ( -0.75**), Harnois index ( -0.678**), Richie index (-0.953**) and Plagioclase Index of Weathering (-0.705**). The trace elemental concentration ranges were above the values of world soils having an enrichment index more than 1 in Kanjirapalli series (P3) and Ni contamination in genetic horizons (Ni > 200µgg-1 ). The cluster analysis showed similar major oxide concentration pattern in Group -1 and Group - 2 but varied in trace elemental pattern with Cr > Ba > Cu in Group - 1 and Cu > Cr > Ba in Group- 2 soils whereas Zr > Ni > Mn in Group - 3 to Ni > Mn > Zr in Group - 4 soils. The study further showed that differential rate of weathering in soils under tropical climate was further accelerated due to anthropogenic activities such as improper land use practices and deforestation on sleep slopes
Measurement of epidural insertion pressures in labouring women of varying body mass indices and imaging of the lumbar spine to develop a high-fidelity epidural simulator for training.
To create high-fidelity epidural simulators it is important to incorporate in vivo epidural pressures.1 This study presents the results of insertion pressures as a Tuohy needle is advanced through to the epidural space on a porcine cadaver followed with a clinical trial of labouring women of varying BMIs. The ultimate aim is to use these measured epidural pressures together with ultrasound and MRI images for the development of a novel epidural simulator to aid training
Quantification of the pressures generated during insertion of an epidural needle in labouring women of varying body mass indices
Objective: The primary aim of this study was to measure pressure generated on a Tuohy needle during the epidural procedure in labouring women of varying body mass indices (BMI) with a view of utilising the data for the future development of a high fi delity epidural simulator. High-fi delity epidural simulators have a role in improving training and safety but current simulators lack a realistic experience and can be improved. Methods: This study was approved by the National Research Ethics Service Committee South Central, Portsmouth (REC reference 11/SC/0196). After informed consent epidural needle insertion pressure was measured using a Portex 16-gauge Tuohy needle, loss-of-resistance syringe, a three-way tap, pressure transducer and a custom-designed wireless transmitter. This was performed in four groups of labouring women, stratifi ed according to BMI kg/m2: 18-24.9; 25-34.9; 35-44.9 and >=45. One-way ANOVA was used to compare difference in needle insertion pressure between the BMI groups. A paired t-test was performed between BMI group 18-24.9 and the three other BMI groups. Ultrasound images of the lumbar spine were undertaken prior to the epidural procedure and lumbar magnetic resonance imaging (MRI) was performed within 72h post-delivery. These images will be used in the development of a high fi delity epidural simulator. Results: The mean epidural needle insertion pressure of labouring women with BMI 18-24.9 was 461mmHg; BMI 25-34.9 was 430mmHg; BMI 35-44.9 was 415mmHg and BMI >=45 was 376mmHg, (p=0.52). Conclusion: Although statistically insignifi cant, the study did show a decreasing trend of epidural insertion pressure with increasing body mass indices
Interplay of fission modes in mass distribution of light actinide nuclei 225,227Pa
Fission-fragment mass distributions were measured for 225,227Pa nuclei formed
in fusion reactions of 19F + 206, 208Pb around fusion barrier energies.
Mass-angle correlations do not indicate any quasi-fission like events in this
bombarding energy range. Mass distributions were fitted by Gaussian
distribution and mass variance extracted. At below-barrier energies, the mass
variance was found to increase with decrease in energy for both nuclei. Results
from present work were compared with existing data for induced fission of 224,
226Th and 228U around barrier energies. Enhancement in mass variance of 225,
227Pa nuclei at below-barrier energies shows evidence for presence of
asymmetric fission events mixed with symmetric fission events. This is in
agreement with the results of mass distributions of nearby nuclei 224, 226Th
and 228U where two-mode fission process was observed. Two-mode feature of
fission arises due to the shell effects changing the landscape of the potential
energy surfaces at low excitation energies. The excitation-energy dependence of
the mass variance gives strong evidence for survival of microscopic shell
effects in fission of light actinide nuclei 225, 227Pa with initial excitation
energy ~30 - 50 MeV
Measurement of epidural insertion pressures in labouring women of varying BMIs. Abstract
To create high-fidelity epidural simulators it is important to incorporate in vivo epidural pressures.1 This study presents the results of insertion pressures as a Tuohy needle is advanced through to the epidural space on a porcine cadaver followed by a clinical trial of labouring women of varying BMIs. The ultimate aim is to use these measured epidural pressures together with ultrasound and MRI images for the development of a novel epidural simulator to aid training
Advances in Gene Ontology Utilization Improve Statistical Power of Annotation Enrichment
Gene-annotation enrichment is a common method for utilizing ontology-based annotations in gene and gene-product centric knowledgebases. Effective utilization of these annotations requires inferring semantic linkages by tracing paths through edges in the ontological graph, referred to as relations. However, some relations are semantically problematic with respect to scope, necessitating their omission or modification lest erroneous term mappings occur. To address these issues, we created the Gene Ontology Categorization Suite, or GOcats—a novel tool that organizes the Gene Ontology into subgraphs representing user-defined concepts, while ensuring that all appropriate relations are congruent with respect to scoping semantics. Here, we demonstrate the improvements in annotation enrichment by re-interpreting edges that would otherwise be omitted by traditional ancestor path-tracing methods. Specifically, we show that GOcats’ unique handling of relations improves enrichment over conventional methods in the analysis of two different gene-expression datasets: a breast cancer microarray dataset and several horse cartilage development RNAseq datasets. With the breast cancer microarray dataset, we observed significant improvement (one-sided binomial test p-value = 1.86E-25) in 182 of 217 significantly enriched GO terms identified from the conventional path traversal method when GOcats’ path traversal was used. We also found new significantly enriched terms using GOcats, whose biological relevancy has been experimentally demonstrated elsewhere. Likewise, on the horse RNAseq datasets, we observed a significant improvement in GO term enrichment when using GOcat’s path traversal: one-sided binomial test p-values range from 1.32E-03 to 2.58E-44
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