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Generally Coronal Mass Ejections (CMEs) are large eruptions of plasma and magnetic field from the Sun into interplanetary space. CMEs are most frequently associated with a variety of phenomena occurring in the lower corona before, during and after onset of eruption and generally are visible in coronagraph observation. Stealth CMEs do not obviously exhibit any of the low-coronal signatures (LCS) like solar flares, flows, jets, coronal dimmings or brightenings, filament eruptions or the formation of flare loop arcades. In this study, five stealth CMEs are selected using LASCO/SOHO CME catalogue and associated ICMEs (Interplanetaty CMEs) are identified using data from STEREO, ACE and WIND.
We have used the Coronagraphic and Heliospheric Imaging data from Solar TErrestrial RElations Observatory (STEREO) to observe a prominence which is erupted on June 7th 2011. This prominence is subjected to the morphological evolution of MRT instability from the lower solar corona upto the inter-planetary space. The unstable structures are converted into the bunch of localized plasma spikes due to the turbulent mixing, and propagate in the inter-planetary space upto 1 A.U.
It has been established that Coronal Mass Ejections (CMEs) may have significant impact on terrestrial magnetic field and lead to space weather events. In the present study, we selected several CMEs which are associated with filament eruptions on the Sun. We attempt to identify the presence of filament material within ICME at 1AU. We discuss how different ICMEs associated with filaments lead to moderate or major geomagnetic activity on their arrival at the Earth. Our study also highlights the difficulties in identifying the filament material at 1AU within isolated and in interacting CMEs.
Coronal Mass Ejections (CMEs) contribute to the perturbation of solar wind in the heliosphere. Thus, depending on the different phases of the solar cycle and the rate of CME occurrence, contribution of CMEs to solar wind parameters near the Earth changes. In the present study, we examine the long term occurrence rate of CMEs, their speeds, angular widths and masses. We attempt to find correlation between near sun parameters of the CMEs with near the Earth measurements. Importantly, we attempt to find what fraction of the averaged solar wind mass near the Earth is provided by the CMEs during different phases of the solar cycles.
Using HINODE/XRT, GOES, SDO/AIA observations, we study a compact C-1.4 class flare outside a major sunspot of AR 12178 on 4 October 2014. This flare is associated with a peculiar coronal jet, which is erupted in two stages in the overlying corona above the compact flaring region. At the time of flare maximum, the first stage of the jet eruption occurs above the flare energy release site, and thereafter in the second stage its magneto-plasma system interacts with the overlying distinct magnetic field domain in its vicinity to build further the typical jet plasma column.
We have studied three Interplanetary Coronal Mass Ejections (ICMEs) having clear signatures of magnetic cloud (MC) arrival at 1 AU and their associated solar sources during 2011 to 2013. Comparing the axial magnetic field strength (B0) of the near-Sun coronal flux-ropes with that of the MC at 1 AU, we have found that the average inferred value of B0 at 1 AU assuming the self-similar expansion of the flux-rope is two times smaller than the value of B0 obtained from the results of MC fitting. Furthermore, by comparing the initial orientation of the flux-rope near the Sun and its final orientation at 1 AU we have found that the three CMEs exhibited more than 80° rotation during its propagation through the interplanetary medium. Our study suggests that although the near-Sun magnetic properties of coronal flux-ropes can be used to infer the field strength of the associated MC at 1 AU, it is difficult to estimate the final orientation of the MC axis in order to predict the geo-effectiveness of the ICMEs.
Methods for efficient variance-based global sensitivity analysis of complex high-dimensional problems are presented and compared. Variance decomposition methods rank inputs according to Sobol indices that can be computationally expensive to evaluate. Main and interaction effect Sobol indices can be computed analytically in the Kennedy and O'Hagan framework with Gaussian processes. These methods use the high-dimensional model representation concept for variance decomposition that presents a unique model representation when inputs are uncorrelated. However, when the inputs are correlated, multiple model representations may be possible leading to ambiguous sensitivity ranking with Sobol indices. In this work, we present the effect of input correlation on sensitivity analysis and discuss the methods presented by Li and Rabitz in the context of Kennedy and O'Hagan's framework with Gaussian processes. Results are demonstrated on simulated and real problems for correlated and uncorrelated inputs and demonstrate the utility of variance decomposition methods for sensitivity analysis.
A ratio-based logistic model developed to assess elephant harvest rates, based on a study at Nagarhole Tiger Reserve in India, was recommended as a management tool to control human–elephant conflict through culling. Considering this reserve among others violates an assumption of the logistic model: isolation. Nevertheless, assuming this violation was irrelevant, we re-evaluated the model, with minor modifications, for the neighbouring Mudumalai Tiger Reserve, where we used data from 13 elephant Elephas maximus population surveys to derive bootstrapped sets of population ratios, and mortality records. We generated arrays of harvest regimes and examined which ratio outputs were closest to the bootstrapped ratios. Our results indicated that (1) model outputs corresponded best with the Mudumalai population structure when harvest regimes were extreme and unlikely, (2) there were significant differences in population structure and harvest regimes between Nagarhole and Mudumalai, and (3) only 49% of adult male deaths predicted by model outputs were recorded in official governmental records. The model provides significantly different results among reserves, which invalidates it as a tool to predict change across the entire elephant population. Variability in survey data and inaccuracies in transition probabilities are sufficiently large to warrant caution when using them as a basis for deterministic modelling. Official mortality databases provide a weak means of validation because poaching incidents are poorly recorded. We conclude that the model should be based on validated transition probabilities and encompass the entire regional population.
A compact printed 2 × 2 ultrawideband (UWB) multiple input multiple output (MIMO) antenna with a single circular patch as a common radiator for both the antenna elements is presented in this paper. A single circular patch is excited by two tapered CPW feeds for dual polarization. To improve the isolation between two ports, a rectangular slot of dimension L1 × W1 is created in the radiator. The UWB MIMO antenna has impedance bandwidth of 3–12 GHz with a isolation better than 17 dB between the two ports. The envelope correlation coefficient and the capacity loss are evaluated to ensure the good diversity performance of UWB MIMO antenna. The antenna has a compact size of 45 × 45 mm2 and is fabricated on low cost FR4 substrate and measured using Agilent VNA. The simulated and measured results show that the proposed UWB antenna is good candidate for UWB MIMO applications.
Overuse of acetolactate synthase (ALS)–inhibiting herbicides in rice has led to the evolution of halosulfuron-resistant rice flatsedge in Arkansas and Mississippi. Resistant accessions were cross-resistant to labeled field rates of ALS-inhibiting herbicides from four different families, in comparison to a susceptible (SUS) biotype. Resistance index of Arkansas and Mississippi accessions based on an R/S ratio of the lethal dose required for 50% plant mortality (LD50) to bispyribac-sodium, halosulfuron, imazamox, and penoxsulam was ≥ 21-fold. Control of Arkansas, Mississippi, and SUS accessions with labeled field rates of 2,4-D, bentazon, and propanil was ≥ 93%. An enzyme assay revealed that an R/S ratio for 50% inhibition (I50) of ALS for halosulfuron was 2,600 and 200 in Arkansas and Mississippi, respectively. Malathion studies did not reveal enhanced herbicide metabolism in resistant plants. The ALS enzyme assay and cross-resistance studies point toward altered a target site as the potential mechanism of resistance. Trp574–Leu amino acid substitution within the ALS gene was found in both Arkansas and Mississippi rice flatsedge accessions using the Illumina HiSeq platform, which corresponds to the mechanism of resistance found in many weed species. Field-rate applications of 2,4-D, bentazon, and propanil can be used to control these ALS-resistant rice flatsedge accessions.
To present the profile of patients undergoing surgical treatment for vertigo at a contemporary institutional vertigo clinic.
A retrospective analysis of clinical charts.
The charts of 1060 patients, referred to an institutional vertigo clinic from January 2003 to December 2012, were studied. The clinical profile and long-term outcomes of patients who underwent surgery were analysed.
Of 1060 patients, 12 (1.13 per cent) were managed surgically. Of these, disease-modifying surgical procedures included perilymphatic fistula repair (n = 7) and microvascular decompression of the vestibular nerve (n = 1). Labyrinth destructive procedures included transmastoid labyrinthectomy (n = 2) and labyrinthectomy with vestibular nerve section (n = 1). One patient with vestibular schwannoma underwent both a disease-modifying and destructive procedure (translabyrinthine excision). All patients achieved excellent vertigo control, classified as per the American Academy of Otolaryngology – Head and Neck Surgery 1995 criteria.
With the advent of intratympanic treatments, surgical treatments for vertigo have become further limited. However, surgery with directed intent, in select patients, can give excellent results.
The present study investigates the joining of 5-mm-thick plates of superaustenitic stainless steel, AISI 904L by continuous current (CC) and pulsed current (PC) gas tungsten arc welding (GTAW) using ER2553 and ERNiCrMo-4 fillers. This research article attempts to provide a detailed structure–property relationship of these weldments. Interface microstructure revealed the absence of deleterious secondary phases at the heat affected zone in all the cases. Skeletal delta ferrite morphology at the cap of ER2553 fusion zone and multidirectional grain growth at the ERNiCrMo-4 fusion zone were observed for both the weldments. The average hardness at the fusion zone was found to be higher for PCGTA weldments using ER2553 due to the higher proportions of ferrite. Tensile studies corroborated that the failure occurred at the parent metal in all the cases. Charpy V-notch studies divulged that the CCGTA and PCGTA weldments utilizing ERNiCrMo-4 filler exhibited the greater impact toughness of 69 J and 75 J, respectively. The bend test results conveyed that both the CCGTA and PCGTA weldments using ERNiCrMo-4 exhibited soundness and ductility.
Sesame (Sesamum indicum L.) is one of the oldest and most nutritional oilseed crops, of which domestication history has been poorly understood. This study suggested that sesame has undergone domestication bottleneck during its use for a long time. In this investigation, the molecular analysis included 4.4 Mbp of the genomic DNA of sesame comprising stearoyl acyl desaturase (sad), fatty acid desaturase 2 (fad2) and omega 3 fatty acid desaturase (o3fad) genes in 99 accessions of four populations of sesame germplasm namely: wild species, landraces, improved cultivars and introgressed lines. Results indicated that the improved cultivars and landraces lost 46.6 and 36.7% of nucleotide diversity, respectively, which indicate that the genetic diversity of the crop had been eroded due to selection after domestication. However, there was no significant reduction in genetic diversity of improved cultivars compared with landraces, indicating that unique improved cultivars generated through crosses were of less frequency in this population. Moreover, introgressed lines retained only 17.77% (π) and 4.57% (θ) of landrace diversity. To evaluate the impact of selection across fatty acid biosynthetic pathway, individual nucleotide diversity at three major genes involved in the pathway was surveyed. The analysis between wild and improved cultivars supported positive selection in fad2 and o3fad loci. Though locus-to-locus sequence variation was observed, positive results with two most important loci supported selection after domestication. Reduced diversity in these critical quality governing genes in improved cultivars suggested that future sesame cultivation would benefit from the incorporation of alleles from sesame's wild relatives.
This work illustrates that a variety of nanowire microstructures can be obtained either by controlling the nanowire formation kinetics or by suitable thermal processing of as-deposited nanowires with nonequilibrium metastable microstructure. In the present work, 200-nm diameter Ag–Ni nanowires with similar compositions, but with significantly different microstructures, were electrodeposited. A 15 mA deposition current produced nanowires in which Ag-rich crystalline nanoparticles were embedded in a Ni-rich amorphous matrix. A 3 mA deposition current produced nanowires in which an Ag-rich crystalline phase formed a backbone-like configuration in the axial region of the nanowire, whereas the peripheral region contained Ni-rich nanocrystalline and amorphous phases. Isothermal annealing of the nanowires illustrated a phase evolution pathway that was extremely sensitive to the initial nanowire microstructure.
Starting as a crisis of sub-prime mortgages in the United States, the US financial crisis became intertwined with a global economic crisis during 2007–09. All major economies were adversely affected. While some countries went into deep recession, others escaped with limited erosion in their growth rates. But the crisis also accelerated the pace at which a new world economic order is emerging, the centerpiece of which is a group now referred to as the G20 group. Together the G20 economies comprise about 90 per cent of global gross national product, 80 per cent of world trade (including EU intratrade) and two-thirds of the world population. The epicentre of the world economic power, which had until recently been concentrated in the hands of the G-7 economies, is now more wide spread with considerable economic power slowly shifting to emerging economies like China and India.
In this paper, the author looks at the effects of the global crisis as it affected the G20 members with special reference to India. The global crisis also witnessed a weakening of the efforts regarding international burden sharing for a long-felt need for support for achieving both the MDG goals and international climate change related efforts. He also examines both conventional and innovative methods of financing the international effort for achieving the MDG objectives and the approach that India may develop in this context as part of the G20 group.
This chapter is divided into several sections. The following section looks at the position of the G20 economies as they emerge out of the global crisis. The next section examines the Indian economy as it faced and emerged out of the crisis. Next the author looks at the position of the G20 economies in the context of international burden sharing in the post-crisis world.
Effect of Gd substitution at Y-site on the structural and magnetic properties of Y1-xGdxMnO3 (x=0, 0.05) nanoparticles prepared by conventional solid state reaction method has been studied. The structural study using X-ray diffraction pattern indicates the hexagonal structure with P63cm space group for all the samples. The average particle size for all the samples lies in the range of 30-40 nm as confirmed by X-ray diffraction and transmission electron microscopy analysis. The change in a and c lattice parameters confirm the substitution of Gd at Y-site. Magnetization versus temperature measurements show enhanced magnetic moment and an increase in Neel temperature with Gd-doping. Spin glass behavior is observed at low temperature in all the samples. Exchange bias effect has been observed at 5 K after field cooling the samples which is ascribed to the formation of antiferromagnetic-ferromagnetic (AFM-FM) core-shell structure of the nanoparticles. A significant improvement in the dielectric properties of Gd-doped samples has also been observed.
A total of 34 tomato genotypes (24 F1+10 parents) were tested for resistance to tomato leaf curl virus (ToLCV) disease by various whitefly inoculation techniques under field and insect-proof glasshouse (mass and cage) conditions. Of the ten tomato parental lines, two accessions [EC-520061 (Solanum habrochaites) and EC-521080 (Solanum pimpinellifolium)] were identified as highly resistant while four accessions (EC-520049, EC-528372, WIR-5032 and WIR-3957) of wild species were resistant to ToLCV. Out of the 24 F1 crosses, PBC×EC-520061, H-86×EC-520061, H-24×EC-520061 and DVRT-2×EC-520061 were found to be highly resistant against ToLCV disease. Biochemical (total phenol and total sugar concentration) and physiological (chlorophyll content and leaf area index) parameters were also used in healthy and disease-inoculated leaves of ten parents and six F1 hybrids to test the conformity of ToLCV-resistant and susceptible disease reactions. The results showed that among the 16 genotypes (10 parents+6 F1), EC-520061, EC-520049, PBC×EC-520061 and H-86×EC-520061 were stable for both biochemical and physiological markers while EC-521080 showed higher accumulations of total phenol and sugar concentrations and reduced leaf size between healthy and disease-inoculated leaves. The present study demonstrates the importance of the whitefly inoculation technique and biochemical and physiological markers in virus resistance screening programmes, and identifies a potential source of resistance to the ToLCV in Solanum species.
A 4.9-m-thick lake sequence, formed due to the landslide damming of a stream in the semiarid Garhwal Himalaya, was studied to understand past monsoonal variations in the region. The Optically Stimulated Luminescence (OSL) chronology indicates that the lake existed between ~ 12 and ~ 7 ka ago. Chronologically constrained trends of sand percent, organic phosphorus (OP), apatite inorganic phosphorus (AIP) and parameters of environmental magnetism were measured in the paleolake profile. Measured proxies indicate that the Indian summer monsoon ameliorated in the early Holocene after 12 ka cooling, and it appears that all the proxies from the lake have captured this globally recognized early Holocene warming. Four phases of wet conditions (intensified monsoon) are recognized at ~ 11.5 ka, ~ 11–10.5 ka, ~ 10–9 ka and ~ 8–7 ka with maximum uncertainties of ~ 1000 years. The wet phases are characterized by high magnetic susceptibility, increased OP and reduced AIP. In an attempt to understand the primary forcing of the sharp fluctuations in monsoonal activity in the region, we show that changes in magnetic susceptibility match variations of residual atmospheric δ14C, suggesting a role for solar variability as an explanation of climatic variability.
The atomic and electronic structures of multilayer graphene on a monolayer boron nitride (MLBN) have been investigated by using the pseudopotential method and the local density approximation (LDA) of the density functional theory (DFT). We show that the LDA energy band gap can be tuned in the range 41-278 meV for a multilayer graphene by using MLBN as a substrate. The dispersion of the π/π* bands slightly away from the K point is linear with the electron speed of 0.9×106 and 0.93×106 for graphene (MLG)/MLBN and ABA trilayer graphene (TLG)/MLBN systems, respectively. This behaviour becomes quadratic with a relative effective mass of 0.0021 for the bilayer graphene (BLG)/MLBN system. The calculated binding energies are in the range of 10-43 meV per C atom.