436 research outputs found

    Linear Approximations to AC Power Flow in Rectangular Coordinates

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    This paper explores solutions to linearized powerflow equations with bus-voltage phasors represented in rectangular coordinates. The key idea is to solve for complex-valued perturbations around a nominal voltage profile from a set of linear equations that are obtained by neglecting quadratic terms in the original nonlinear power-flow equations. We prove that for lossless networks, the voltage profile where the real part of the perturbation is suppressed satisfies active-power balance in the original nonlinear system of equations. This result motivates the development of approximate solutions that improve over conventional DC power-flow approximations, since the model includes ZIP loads. For distribution networks that only contain ZIP loads in addition to a slack bus, we recover a linear relationship between the approximate voltage profile and the constant-current component of the loads and the nodal active and reactive-power injections

    Comparison between incremental shuttle run test and Harvard’s step test on peak exercise performance in healthy males: a cross-sectional study

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    Background: Cardiovascular fitness is directly related to the physical health of the person. Aerobic capacity (VO2max) is one of the major criteria to decide the cardiovascular fitness of an individual. To help quantify the fitness level by calculating their VO2max, there are various indirect maximal tests available but out of these, which one would predict VO2max better, is a major concern. Hence the purpose of this study was to compare the effects of two indirect maximal tests i.e. Incremental Shuttle Run Test (ISRT) and Harvard’s Step Test (HST) on peak exercise performance in young healthy males.Methods: A cross-sectional study with purposive sampling was performed on healthy untrained 100 males of age group 18-25 years. Day 1 subjects performed ISRT on 20 m track and after a 48 hours rest period, on day 3 same subject performed Harvard’s step test. Pre and post-test parameters (Pulse rate, respiratory rate, systolic and diastolic blood pressure and RPE) were measured and predicted VO2max was calculated.Results: Post-test parameters i.e. PR, RR, SBP significantly increased (p=0.00*) by Harvard’s step test. The diastolic blood pressure did not change significantly (p=0.3) for both the tests. Rating of perceived exertion by both the test was of the range 17-19 (very hard to maximal). Calculated predicted VO2max was significantly more by ISRT than HST in males (p=0.00*).Conclusions: Incremental shuttle run test is more efficient in predicting VO2max than Harvard’s step test in healthy adult’s males

    VERY LARGE SCALE INTEGRATION TINY CHIP WITH NANOPOWER SENSOR APPLICATIONS

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    Semiconductor devices have rapidly advanced over the past years increasing switching(on and off) speed and density of the device, causing an increase in power consumption and power dissipation; accordingly, the issues have been considered and improved . In CMOS 0.5μm process, the designed VLSI mirror-amplifier had power dissipation of 8.41 milliwatts. This technique is changed in this paper. The biasing is done in two steps proved to be correct procedure to improve overall power consumption. Source voltage was considered as 3V for the MOSIS process technology. Layout ,simulation and electrical characterization of the design were carried out by MENTOR GRAPHICS tool and CAD tools were used for the design Holding the scaling and process unchanged at 0.5μm as the previous design, the new VLSI design had power dissipation of 4.39 nanowatts in second step by reducing the dynamic loss. Multi-die chip placement is done for fabrication. More advanced 0.35um CMOS process is used for low threshold voltage and enhanced supply voltage range. This paper presents details of the key research works, results, completed chip layout and applications of the chip

    Comparative efficacious study between preoperative pregabalin and gabapentin on postoperative pain in abdominal hysterectomy: an institutional experience

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    Background: Pain is a consistent and predominant complaint following surgical intervention including abdominal open hysterectomy. A multimodal approach has been suggested to improve postoperative analgesia and to reduce opioid related side effects. In this context we conducted a comparative study on efficacy between gabapentin and pregabalin on postoperative pain relief.Methods: In this prospective randomised study, 60 patients were divided in to two arms group G and group P. 900 mg of gabapentin and 300 mg of pregabalin were administered orally one hour before spinal anaesthesia to respective groups. Hemodynamic parameters such as heart rate, mean arterial pressure, respiratory rate was monitored pre, per and postoperatively. Also, the need for first analgesic dose and visual analog pain score were documented in all subjects of both groups. Statistical analysis with SPSS 16.0 performed.Results: There was significant fall in mean arterial pressure in group G than group P patients. Further the fall in mean pulse rate was more in group G compared to group P throughout pre, per and post-operative phases. In terms of mean postoperative time required for first dose of analgesic drug, pregabalin and gabapentin was required after 7 and 5 hours respectively. There was a statistically significant change in Visual Analogue Scale, showing pregabalin as better drug than gabapentin in post operative pain control with score 5 and 7 respectively.Conclusions: Pre-emptive analgesia with pregabalin appears to be superior to gabapentin as a part of multimodal perioperative pain management in abdominal hysterectomy

    Ciliary Neurotrophic Factor Induces Genes Associated with Inflammation and Gliosis in the Retina: A Gene Profiling Study of Flow-Sorted, Müller Cells

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    Ciliary neurotrophic factor (CNTF), a member of the interleukin-6 cytokine family, has been implicated in the development, differentiation and survival of retinal neurons. The mechanisms of CNTF action as well as its cellular targets in the retina are poorly understood. It has been postulated that some of the biological effects of CNTF are mediated through its action via retinal glial cells; however, molecular changes in retinal glia induced by CNTF have not been elucidated. We have, therefore, examined gene expression dynamics of purified Müller (glial) cells exposed to CNTF in vivo.Müller cells were flow-sorted from mgfap-egfp transgenic mice one or three days after intravitreal injection of CNTF. Microarray analysis using RNA from purified Müller cells showed differential expression of almost 1,000 transcripts with two- to seventeen-fold change in response to CNTF. A comparison of transcriptional profiles from Müller cells at one or three days after CNTF treatment showed an increase in the number of transcribed genes as well as a change in the expression pattern. Ingenuity Pathway Analysis showed that the differentially regulated genes belong to distinct functional types such as cytokines, growth factors, G-protein coupled receptors, transporters and ion channels. Interestingly, many genes induced by CNTF were also highly expressed in reactive Müller cells from mice with inherited or experimentally induced retinal degeneration. Further analysis of gene profiles revealed 20-30% overlap in the transcription pattern among Müller cells, astrocytes and the RPE.Our studies provide novel molecular insights into biological functions of Müller glial cells in mediating cytokine response. We suggest that CNTF remodels the gene expression profile of Müller cells leading to induction of networks associated with transcription, cell cycle regulation and inflammatory response. CNTF also appears to function as an inducer of gliosis in the retina

    Take a Step Back: Evoking Reasoning via Abstraction in Large Language Models

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    We present Step-Back Prompting, a simple prompting technique that enables LLMs to do abstractions to derive high-level concepts and first principles from instances containing specific details. Using the concepts and principles to guide the reasoning steps, LLMs significantly improve their abilities in following a correct reasoning path towards the solution. We conduct experiments of Step-Back Prompting with PaLM-2L models and observe substantial performance gains on a wide range of challenging reasoning-intensive tasks including STEM, Knowledge QA, and Multi-Hop Reasoning. For instance, Step-Back Prompting improves PaLM-2L performance on MMLU Physics and Chemistry by 7% and 11%, TimeQA by 27%, and MuSiQue by 7%

    Structural and functional characterization of proteinase inhibitors from seeds of Cajanus cajan (cv. ICP 7118)

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    Proteinase inhibitors (C11PI) from mature dry seeds of Cajanus cajan (cv. ICP 7118) were purified by chromatography which resulted in 87-fold purification and 7.9% yield. SDS-PAGE, matrix assisted laser desorption ionization time-of-flight (MALDI-TOF/TOF) mass spectrum and two-dimensional (2-D) gel electrophoresis together resolved that C11PI possessed molecular mass of 8385.682 Da and existed as isoinhibitors. However, several of these isoinhibitors exhibited self association tendency to form small oligomers. All the isoinhibitors resolved in Native-PAGE and 2-D gel electrophoresis showed inhibitory activity against bovine pancreatic trypsin and chymotrypsin as well as Achaea janata midgut trypsin-like proteases (AjPs), a devastating pest of castor plant. Partial sequences of isoinhibitor (pI 6.0) obtained from MALDI-TOF/TOF analysis and N-terminal sequencing showed 100% homology to Bowman-Birk Inhibitors (BBIs) of leguminous plants. C11PI showed non-competitive inhibition against trypsin and chymotrypsin. A marginal loss (<15%) in C11PI activity against trypsin at 80 °C and basic pH (12.0) was associated with concurrent changes in its far-UV CD spectra. Further, in vitro assays demonstrated that C11PI possessed significant inhibitory potential (IC50 of 78 ng) against AjPs. On the other hand, in vivo leaf coating assays demonstrated that C11PI caused significant mortality rate with concomitant reduction in body weight of both larvae and pupae, prolonged the duration of transition from larva to pupa along with formation of abnormal larval-pupal and pupal-adult intermediates. Being smaller peptides, it is possible to express C11PI in castor to protect them against its devastating pest A. janata

    Creation of leaderless FMDV replicon for development of replication defective virus (leaderless FMDV): A strategy towards the development of attenuated vaccine with marker facility

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    26-34Leader protease (Lpro) of foot-and-mouth disease virus (FMDV) which is essential for viral replication and pathogenicity in host is found in two forms, Lab and Lb with similar activity but, both differing only at amino-termini with separate initiation codons, 84 nucleotides apart. After translation of the genomic RNA into single polyprotein, the L protease is released autocatalytic from the N terminus and cleaves the p220 subunit of the eukaryotic initiation factor 4F complex resulting in the shut off host protein synthesis, an essential step for viral pathogenicity. We exploited this function for development of attenuated virus by deleting the gene encoding Lb protease from FMDV Asia 1(63/72) cDNA replicon (Joshi et al, 2013) by PCR mutagenesis approach. The deletions and intactness of the frames were confirmed by sequence analysis. P1-2A polyprotein gene of FMDV ‘O’ was inserted into the replicon and the full length construct was studied for virulence to baby hamster kidney (BHK) 21 cells. Vaccinia expressing T7 polymerase was used for in vitro RNA generation and infection. The lower cytopathic effect (cpe) as observed by reduced replication efficiency confirmed the effect of Lb deletion when compared with the construct with no deletion
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