395 research outputs found

    A PHARMACOGNOSTIC AND PHYTOCHEMICAL STUDY ON THE MARKET SAMPLES OF NAGAKESARA

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    This work was conducted to evaluate the pharmacognostic and phytochemical study of varieties of Nagakesara. When it is further studied, it is observed that Nagakesara available in the markets of different areas is from different source plants. There are nearly 5 drugs sold in the market with the same name, the common floral parts available in the markets are commonly from Nagakesara (Mesua ferrea Linn.), Surapunnaga (Ochrocarpus longifolius Benth and Hook f.), Tamalpatra (Cinnamomum tamala Nees and Ebern.), Punnaga (Calophyllum inophyllum Linn.), Dillenia pentagyna Roxb. Hence a comparative study of these two samples 1) Nagakesara (Mesua ferrea), and 2) Tamalpatra (Cinnamomum tamala) has been carried out. The phytochemical study shows the presence of tannins, steroids and carbohydrates in almost all varieties of Nagakesara. Flower buds of Nagakesara plant of different species available in the market was taken up for the study. CONCLUSION: A detailed Pharamcognostic and Phytochemical review was done through which it was concluded that Mesua ferrea Linn. belonging to family Guttiferae may be the exact source of Nagakesara. The flower buds of Cinnamomum tamala Nees and Ebern. which is known as black variety in the markets according to our study,

    Effect of oxygen vacancies on spin-dependent tunneling in Fe/MgO/Fe

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    First-principles calculations based on density functional theory are used to elucidate the effect of O vacancies, forming F centers, on spin-dependent tunneling in Fe/MgO/Fe(001) magnetic tunnel junctions. O vacancies produce occupied localized s states and unoccupied resonant p states, which is consistent with available experimental data. The authors find that O vacancies affect the conductance by nonresonant scattering of tunneling electrons causing a substantial reduction of tunneling magnetoresistance (TMR). Improving the quality of the MgO barrier to reduce O vacancy concentration would improve TMR in these and similar junctions

    Survey and identification of entomopathogenic nematodes in the province of Cotabato, Philippines, for biocontrol potential against the tobacco cutworm, Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae)

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    Background: The tobacco cutworm, Spodoptera litura [Fab.] (Lepidoptera: Noctuidae), is a devastating insect pest of several crops. Entomopathogenic nematodes (EPNs) of the families Heterorhabditidae and Steinernematidae are used as an alternative control measure in lieu of the hazardous synthetic chemical applications. Results: A survey of naturally occurring EPNs was conducted across the province of Cotabato, Philippines, covering a total of 5 municipalities with 25 villages. Galleria-baiting technique was employed to recover nematodes from peanut and grassland soils. Out of 50 soil samples collected, only 5 samples harbored nematodes, indicating a recovery of 10%. Preliminary morphological data identified only one EPN under the genera Heterorhabditis (1 isolate), whereas 4 were facultative necromenic nematodes from the genera Metarhabditis (2 isolates) and Oscheius (2 isolates). Analysis of D2D3 segments of the 28S rDNA confirmed high sequence similarity to Heterorhabditis indica, Metarhabditis rainai, Oscheius insectivora, and Oscheius sp. This is the first record of H. indica and M. rainai in the entire region, whereas the first record for Oscheius spp. in the Philippines. Furthermore, the biocontrol potential of the local H. indica infective juvenile (IJ) populations (PIGCD1) isolated from peanut was assessed against the tobacco cutworm, S. litura, under laboratory conditions. The mean percentage mortality caused by H. indica on S. litura at 7 different concentrations ranged from 0-100% at 24 h post inoculation. The lethal concentration (LC50) required to kill 50% of the S. litura larvae population with H. indica was 7.13±1 (IJs/larva). Conclusions: The use of Galleria-baiting method is a convenient approach to detect EPNs including other facultative necromenic nematodes from the soils. Obtained data indicated that the local H. indica isolate can be a promising alternative measure to suppress the economically important insect pest, S. litura, and this may provide significant outlook to establish the biocontrol program in the country

    Signal Durations and local Richter magnitudes in northeast india: An empirical approach

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    Twenty four analog seismic stations are operated by the Regional Research Laboratory (Jorhat), National Geophysical Research Institute (Hyderabad) and by the India Meteorological Department (IMD) in the Northeastern region (NER) of India. 8000 seismograms of 1992 shallow (5-30km) earthquakes recorded by these stations during the period from January 1985 to December 1999, have been used to establish relationships between signal durations and the local Richter magnitudes (ML). In order to obtain the empirical relations for the determination of duration magnitudes (MD), signal duration estimates have been fitted using regression analysis to models of the form Model-I: MD = C0 + C1 Log10 (S.D) + C2 Δ + C3 h Model-II: MD = C0 + C1 Log10 (S.D) + C2 Δ + C3 h + C4 [Log10 (S.D)]2, where S.D is the signal duration in seconds, Δ epicentral distance in degree and h focal depth in km. The models yielded duration magnitudes at each of the 24 stations having standard deviations as low as 0.07. For these stations, station factors are obtained by finding the average of the deviations of network magnitude (i.e. mean estimate of station magnitudes for each earthquake, denoted by MD A) from station magnitudes (MD) for the earthquake events in NER. Over - and under - estimations of station magnitudes with respect to ML are also determined for each station. It has been observed that the estimates of MD (A) scatter up to about 0.8units with respect to ML for both the models. Application of these factors reduced scatter down to ± 0.25 units for both the models. © Geol. Soc. India

    Self-regulation learning as active inference: dynamic causal modeling of an fMRI neurofeedback task

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    Introduction: Learning to self-regulate brain activity by neurofeedback has been shown to lead to changes in the brain and behavior, with beneficial clinical and non-clinical outcomes. Neurofeedback uses a brain-computer interface to guide participants to change some feature of their brain activity. However, the neural mechanism of self-regulation learning remains unclear, with only 50% of the participants succeeding in achieving it. To bridge this knowledge gap, our study delves into the neural mechanisms of self-regulation learning via neurofeedback and investigates the brain processes associated with successful brain self-regulation. Methods: We study the neural underpinnings of self-regulation learning by employing dynamical causal modeling (DCM) in conjunction with real-time functional MRI data. The study involved a cohort of 18 participants undergoing neurofeedback training targeting the supplementary motor area. A critical focus was the comparison between top-down hierarchical connectivity models proposed by Active Inference and alternative bottom-up connectivity models like reinforcement learning. Results: Our analysis revealed a crucial distinction in brain connectivity patterns between successful and non-successful learners. Particularly, successful learners evinced a significantly stronger top-down effective connectivity towards the target area implicated in self-regulation. This heightened top-down network engagement closely resembles the patterns observed in goal-oriented and cognitive control studies, shedding light on the intricate cognitive processes intertwined with self-regulation learning. Discussion: The findings from our investigation underscore the significance of cognitive mechanisms in the process of self-regulation learning through neurofeedback. The observed stronger top-down effective connectivity in successful learners indicates the involvement of hierarchical cognitive control, which aligns with the tenets of Active Inference. This study contributes to a deeper understanding of the neural dynamics behind successful self-regulation learning and provides insights into the potential cognitive architecture underpinning this process

    Native Philippine Heterorhabditis indica isolates from banana and rice fields and preliminary results of their virulence against the larvae of super worm (Zophobas morio Fabricius Coleoptera: Tenebrionidae)

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    Background: Entomopathogenic nematodes (EPNs) of the families Heterorhabditidae and Steinernematidae are used as biological control agents of several insect pests in lieu of synthetic pesticides. Results: Using an insect-baiting technique, naturally occurring EPN isolates were collected from banana and rice fields in the municipality of Hagonoy, the Philippines. A total of 4 isolates were recovered from all the sites namely, HBP1, HBP2, HR3 and HR4. By combining morphometrical and ITS rDNA data, all the isolates were identified as Heterorhabditis indica. To initially assess their infectivity, virulence tests were conducted on the last instar larvae of the super worm, Zophobas morio Fabricius (Coleoptera: Tenebrionidae), the model insect. HR3 isolate had the highest percentage mortality (56%), followed by HBP1 and HBP2 (33%), which were comparable to the available nematode in the market, Heterorhabditis bacteriophora (44%), whereas the lowest was obtained in HR4 isolate (11%). Conclusions: This study accounted 4 more H. indica isolates in addition to pre-existing isolates in the country, expanding its habitat range and geographic distribution. This also provides baseline information on the potential biocontrol utilization of native EPNs against soil-dwelling insect pests of agricultural crops. Further investigations are required to assess their efficacy against several other insect pests of economic importance for the integrated pest management (IPM) programmes in the country

    Characterizing peritoneal dialysis catheter use in pediatric patients after cardiac surgery

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    ObjectiveChildren who undergo cardiac surgery are at high risk for renal insufficiency and abdominal compartment syndrome. Peritoneal dialysis catheter (PDC) implantation is used in this population for abdominal decompression and access for dialysis. However, there is no consensus regarding PDC use, and the practice varies widely. This study was undertaken to assess associated factors, outcomes, and variability in the use of PDC in patients who have undergone cardiac surgery.MethodsThe cohort was obtained from the Kids' Inpatient Database, years 2006 and 2009. Patients who underwent cardiac surgery were included and the subset that underwent PDC implantation during the same hospitalization was identified. Univariable and multivariable analyses assessed factors associated with PDC and survival.ResultsA cohort of 28,259 patients underwent cardiac surgery, of whom 558 (2%) had PDCs placed. In the PDC group, 39.1% (n = 218) had acute renal failure whereas 3.5% or patients (n = 974) in the non-PDC group had acute renal failure. Among patients receiving PDC, mortality was 20.3% (n = 113; vs 3.4% overall mortality, n = 955). Excluding patients with acute renal failure, mortality remained 12% (n = 41) for the PDC group. Factors associated significantly with PDC placement in the overall cohort were younger age, greater surgical complexity, nonelective admission, hospital region, use of cardiopulmonary bypass, and acute renal failure.ConclusionsPatients receiving PDC after cardiac surgery had 20% mortality, which remained 12% after excluding patients with acute renal failure. Given the variability in PDC use and poor outcomes, further research is needed to assess the possible benefit of earlier intervention for peritoneal access in this high-risk cohort

    Longitudinal brain atrophy rates in transient ischemic attack and minor ischemic stroke patients and cognitive profiles

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    Introduction: Patients with transient ischemic attack (TIA) and minor stroke demonstrate cognitive impairment, and a four-fold risk of late-life dementia. Aim: To study the extent to which the rates of brain volume loss in TIA patients differ from healthy controls and how they are correlated with cognitive impairment. Methods: TIA or minor stroke patients were tested with a neuropsychological battery and underwent T1 weighted volumetric magnetic resonance imaging scans at fixed intervals over a 3 years period. Linear mixed effects regression models were used to compare brain atrophy rates between groups, and to determine the relationship between atrophy rates and cognitive function in TIA and minor stroke patients. Results: Whole brain atrophy rates were calculated for the TIA and minor stroke patients; n = 38 between 24 h and 18 months, and n = 68 participants between 18 and 36 months, and were compared to healthy controls. TIA and minor stroke patients demonstrated a significantly higher whole brain atrophy rate than healthy controls over a 3 years interval (p = 0.043). Diabetes (p = 0.012) independently predicted higher atrophy rate across groups. There was a relationship between higher rates of brain atrophy and processing speed (composite P = 0.047 and digit symbol coding P = 0.02), but there was no relationship with brain atrophy rates and memory or executive composite scores or individual cognitive tests for language (Boston naming, memory recall, verbal fluency or Trails A or B score). Conclusion: TIA and minor stroke patients experience a significantly higher rate of whole brain atrophy. In this cohort of TIA and minor stroke patients changes in brain volume over time precede cognitive decline
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