Dynamics of Crossover from a Chaotic to a Power Law State in Jerky Flow

We study the dynamics of an intriguing crossover from a chaotic to a power law state as a function of strain rate within the context of a recently introduced model which reproduces the crossover. While the chaotic regime has a small set of positive Lyapunov exponents, interestingly, the scaling regime has a power law distribution of null exponents which also exhibits a power law. The slow manifold analysis of the model shows that while a large proportion of dislocations are pinned in the chaotic regime, most of them are pushed to the threshold of unpinning in the scaling regime, thus providing insight into the mechanism of crossover.Comment: 5 pages, 3 figures. In print in Phy. Rev. E Rapid Communication

Evaluation of Methanolic Leaf Extract of Cymbopogon Citratus on Alcohol Withdrawal Syndrome in Wistar Rats

Alcohol withdrawal syndrome refers to a set of symptoms that occurs within few hours following the cessation of alcohol. Some of the symptoms are anxiety, tremor, hyper locomotion, sweating, nausea, vomiting, and agitation. On severe cases, it may lead to Delirium tremens and Seizures. Benzodiazepines are the popular class of drugs used in the treatment of AWS. But on prolonged usage it may also cause addiction. So, in mild to moderate symptoms of AWS herbal medicines can be used to suppress those symptoms which is of less or no side effect. Wistar albino rats were used in this study. For which permission was granted from the Institutional Animal Ethics Committee[NCP/IAEC/2021-22/01]. Cymbopogon citratus, commonly known as lemongrass is a perennial herb with therapeutic activities such as anti-obesity, anti-diabetic, anti-hepatotoxic, anti-anxiety and anti-microbial activity. It is selected to evaluate its activity against AWS. The plant was identified and authenticated by the Tamilnadu Agricultural University, Coimbatore[BSI/SRC/5/23/2020/Tech]. The leaves of the plant were collected and the methanolic extract was prepared by maceration process. Phytochemical screening confirmed the presence of flavonoid, aldehyde, terpenoid, tannin, phenolic compounds, saponin, alkaloid, unsaturated steroids and steroid derivatives. Alcohol withdrawal syndrome was induced in the wistar rats by administering 10% ethanol for 28 days followed by withdrawal. Diazepam(2mg/kg ip.,) was used as a standard in this study. MECC 200mg/kg and MECC 400 mg/kg were administered to group IV and group V respectively from day 22 to 28. The behavioral parameters were assessed using apparatus such as open field, rota rod, elevated plus maze, forced swim test on the 29th day. The ethanol withdrawal groups shown anxiety, muscle incoordination, depression and hyper locomotion. Which was attenuated by diazepam. But diazepam administration produced sedative effects. Administration of the MECC produced results similar to that of normal control. Then blood was collected on the 31st day and the biochemical parameters such as AST, ALT and ALP were assessed in the serum. The withdrawal group shown increased level of these biomarkers due to hepatotoxicity. Diazepam further increased the hepatic toxicity thus showing increased level of these biomarkers. MECC administration decreased the level of these biomarkers. Animals were sacrificed on the 31st day and the brain and liver were isolated. The brain and liver homogenates were prepared and MDA, SOD, CAT, GSH, GPx were measured. The withdrawal group shown decrease in the level of these antioxidants. Diazepam administration increased the level of these antioxidants in brain. But, in liver it further decreased the level of antioxidants when compared to that of the withdrawal group. MECC (200mg/kg and 400mg/kg) produced significant increase in the level of these antioxidants. The brain and liver samples were histopathologically analysed. The histopathology reports also supports the therapeutic and protective effects of Cymbopogon citratus. CONCLUSION: Alcohol withdrawal syndrome is a group of symptoms that occurs following the cessation of alcohol after a period of excessive alcohol use. These symptoms occur due to alcohol-induced chemical imbalances in the brain which result in excessive neuronal activity if the alcohol is withheld. Herbal medicines can be used for a very long period of time to treat them without possessing any side effects. Based on evidence from previous studies, Cymbopogon citratus was chosen and evaluated for its efficacy against Alcohol withdrawal syndrome in Wistar rats. From the biochemical and behavioral results it can be concluded that the methanolic leaf extract of Cymbopogon citratus possess anti-oxidant activity and it also attenuates the symptoms of Alcohol Withdrawal Syndrome in Wistar rats

A comparative study of exteriorization and intraperitoneal closure of uterus in caesarean delivery

Background: Caesarean delivery is the most common intraperitoneal surgical procedure in obstetrics. Many surgical techniques for caesarean delivery have been described, and the debate about the ideal caesarean technique to minimize morbidity is going on still. The aim of this study was to assess the intraoperative and postoperative advantages and disadvantages following exteriorization of uterus at caesarean section with intraperitoneal repair of uterus.Methods: It is a randomized controlled trial conducted at Adichunchanagiri Institute of Medical Sciences, B G Nagar, Mandya. Minimum of 100 cases, 50 each were randomly allocated into case and control groups. All patients who were undergoing emergency and elective caesarean delivery under spinal anaesthesia were randomly allocated into exteriorization and intraperitoneal group. In exteriorization group, uterus is exteriorized after delivery of foetus and placenta for repair, whereas in intraperitoneal group in situ repair was done. A pfannenstiel incision was taken for all the cases. Placenta was removed either by controlled traction after spontaneous separation or manually. Uterus was exteriorized after delivery of placenta and may be repaired by single or double layer. Visceral and parietal peritoneum are not closed.Results: There is significant difference in the operating time in the exteriorization group and in the in-situ group. But no significant difference between 2 groups regarding nausea, vomiting intra operatively, in return of bowel function, number of analgesic doses, incidence of cystitis, endometritis and wound infection. Period of hospitalization were also same in both groups.Conclusion: Exteriorization of uterus at caesarean delivery has the advantages less perioperative haemoglobin reduction, good exposure, good access to incision angle, especially during difficult extraction. Easy identification of uterine anomaly, adnexal mass if present and exposure of posterior aspect of lower segment

PHYTOSYNTHESIS OF SILVER NANOPARTICLES USING HYGROPHILA AURICULATA LEAF EXTRACT AND ASSESSMENT OF THEIR ANTIBACTERIAL AND ANTIOXIDANT PROPERTIES

Objective: In this study, the phytosynthesis of silver nanoparticles (AgNPs) using leaf extracts of Hygrophila auriculata (HA) and their biological activities was investigated.Methods: The synthesis of AgNPs was done by using the green synthetic method and analyzed by UV-Visible spectroscopy, X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR) and further characterized by transmission electron microscopy (TEM) and dynamic light scattering (DLS). The antibacterial activity of HA AgNPs was studied by agar well diffusion method and micro broth dilution method for determination of minimum inhibitory concentration (MIC). The antioxidant potentials of HA AgNPs were detected by Diphenyl-1-picryl hydrazyl radical scavenging assay (DPPH), Phosphomolybdenum assay, reducing power assay.Results: The prepared HA AgNPs showed characteristic absorption peak at 420 nm in the UV-Vis spectrum. FTIR spectra had shown that the biomolecules present in leaf extract were responsible for the reduction and capping material of silver nanoparticles. XRD study showed the particles found to be crystalline in nature, with a face-centered cubic (fcc) structure. TEM and DLS results revealed that the AgNPs were mostly spherical with an average size ranging from ~15-115 nm with a mean diameter of 40.96 nm. The HA AgNPs showed good antibacterial activity and MIC against Staphylococcus aureus (ATCC 6538), Bacillus cereus (NCIM 2106), Pseudomonas aeruginosa (ATCC 9027) and Escherichia coli (ATCC 8739). In agar well diffusion method, the maximum zone of inhibition was found against Pseudomonas aeruginosa (ATCC 9027) with 18 mm and minimum zone of inhibition was found to be against Escherichia coli (ATCC 8739) with 13 mm. The MIC of the HA AgNp was found to be 5µg against all the test organisms. In addition, the Diphenyl-1-picryl hydrazyl radical scavenging assay (DPPH), Phosphomolybdenum assay, reducing power assay revealed they can be used as the potential scavenger against deleterious damages caused by the free radicals.Conclusion: The present study explored that Hygrophila auriculata which are efficient producers of AgNPs and could act as safe and cost-effective with potential antibacterial and antioxidant activities. These findings encourage studying HA AgNP further for their potential biological applications

A Single Operator Implementation of Task Based Multiple Unmanned Vehicle

ABSTRACT−Automation has greatly reduced operator workload and generally enhanced safety in supervisory control settings. There has recently been a significant amount of activity in developing supervisory control algorithms for multiple unmanned vehicle operation by a single operator. In the both military and commercial sectors there has been significant research and development in the field of unmanned vehicles. The objective of this paper is use to control multiple UV's using single operator by RESCHU software. RESCHU (Research Environment for Supervisory Control of Homogeneous Unmanned vehicles) which allows a single operator have the ability to control multiple UVs. This paper approaches two methods namely Vehicle-Based control (where a single operator individually assigns tasks to unmanned assets) and Task-Based control (where the operator generates a task list, which is then given to the group of vehicles that determine how to best divide the tasks among themselves). The proposed framework incorporates (i) sensor constraints, such as processing/travel time, and (ii) task constraints, such as prioritization. These results have implications for the design of future human-UV systems, as well as more general multiple task supervisory control models

A dynamical approach to the spatiotemporal aspects of the Portevin-Le Chatelier effect: Chaos,turbulence and band propagation

Experimental time series obtained from single and poly-crystals subjected to a constant strain rate tests report an intriguing dynamical crossover from a low dimensional chaotic state at medium strain rates to an infinite dimensional power law state of stress drops at high strain rates. We present results of an extensive study of all aspects of the PLC effect within the context a model that reproduces this crossover. A study of the distribution of the Lyapunov exponents as a function of strain rate shows that it changes from a small set of positive exponents in the chaotic regime to a dense set of null exponents in the scaling regime. As the latter feature is similar to the GOY shell model for turbulence, we compare our results with the GOY model. Interestingly, the null exponents in our model themselves obey a power law. The configuration of dislocations is visualized through the slow manifold analysis. This shows that while a large proportion of dislocations are in the pinned state in the chaotic regime, most of them are at the threshold of unpinning in the scaling regime. The model qualitatively reproduces the different types of deformation bands seen in experiments. At high strain rates where propagating bands are seen, the model equations are reduced to the Fisher-Kolmogorov equation for propagative fronts. This shows that the velocity of the bands varies linearly with the strain rate and inversely with the dislocation density, consistent with the known experimental results. Thus, this simple dynamical model captures the complex spatio-temporal features of the PLC effect.Comment: 17 pages, 18 figure

Drug utilization study of drugs used in the management of post-partum hemorrhage at a tertiary care hospital

Background: Postpartum haemorrhage remains a major cause of both maternal mortality and morbidity worldwide, uterotonic drugs such as oxytocin, with or without ergometrine, have been used to prevent PPH. The objective to study the drugs used in the management of post-partum haemorrhage at a tertiary care hospital.Methods: An observational and cross-sectional study design was adopted for this study. The case sheets of 100 patients presenting in active stage of labour to the labour room in a tertiary care hospital were analysed.Results: In the prescriptions analysed from the patients in the labour room, drugs used to prevent PPH are oxytocin and misoprostol. Oxytocin is the most commonly prescribed drug to prevent PPH in the study group. It is a life-saving drug to prevent PPH and thereby maternal mortality. In the study group having 103 patients, a total of 81 patients received only 10 IU oxytocin IM and 14 patients received 10 IU oxytocin IM and 600 g misoprostol to prevent PPH.Conclusions: Oxytocin is an essential drug included in the WHO essential drug list and in the national list of essential medicine, so it shouldn’t have been dealt in such a biased manner

The hidden order behind jerky flow

Jerky flow, or the Portevin-Le Chatelier effect, is investigated at room temperature by applying statistical, multifractal and dynamical analyses to the unstable plastic flow of polycrystalline Al-Mg alloys with different initial microstructures. It is shown that a chaotic regime is found at medium strain rates, whereas a self-organized critical dynamics is observed at high strain rates. The cross-over between these two regimes is signified by a large spread in the multifractal spectrum. Possible physical mechanisms leading to this wealth of patterning behavior and their dependence on the strain rate and the initial microstructure are discussed