Plastid genome evolution and inheritance in Passiflora

Plastid genomes (plastomes) of photosynthetic angiosperms are for the most part highly conserved in their organization, mode of inheritance and rates of nucleotide substitution. A small number of distantly related lineages including Passiflora share a syndrome of features that deviate from this general pattern, including extensive genomic rearrangements, accelerated rates of nucleotide substitution, biparental inheritance and plastome-genome incompatibility. Plastome evolution studies in Passiflora are limited in taxon sampling; hence the phylogenetic extent of the rearrangements is unknown. To gain better understanding in plastome evolution in Passiflora, plastomes from 31 taxa and transcriptomes from 6 species were sequenced and assembled. In addition, interspecific crosses within two largest subgenera, Passiflora and Decaloba, were greatly expanded to understand mode of plastid inheritance in the genus. Phylogenomic analyses with 68 protein-coding genes generated a fully resolved, strongly supported tree that is congruent with the comprehensive phylogenies based on a few plastid and nuclear loci. Extensive rearrangements were detected including several gene/intron losses, inverted repeat expansion/contraction and inversions, some of which occurred in parallel. Nucleotide substitution rate analyses of 68 protein-coding genes across the genus showed lineage- and locus-specific acceleration. Comparative transcriptome analyses identified missing or divergent plastid genes in Passiflora that have followed three distinct evolutionary paths: transfer to the nucleus, substitution by the nuclear genes and highly divergent gene that likely remain functional. Plastid-encoded rps7 was transferred into the intron of a nuclear-encoded plastid-targeted thioredoxin m-type gene, acquiring its plastid transit peptide. Plastid rpl20 likely experienced a novel substitution by a duplicated, nuclear-encoded mitochondrial-targeted rpl20 that has a similar gene structure. Interspecific hybrids in Passiflora exhibit diverse modes of plastid inheritance including a clade-specific paternal or maternal pattern along with frequent transmission of biparental plastids. Furthermore, heteroplasmy due to biparental inheritance was restricted to early developmental stage in hybrids and plastid types from either parent were excluded in older plants resulting plastid homogeneity. These results of unusual plastome dynamics and inheritance identified in Passiflora presents the genus as an exciting system to study plastome evolution in angiospermsPlant Biolog

Modeling Polarization and Capacitance Hysteresis of Ferroelectric Capacitors

A simulation based comparative study of the polarization hysteresis of the ferroelectric capacitor using various ferroelectric models is presented. A 2-dimensional finite element device-level model was implemented using SILVACO\u27s ATLAS device simulator to generate the polarization hysteresis characteristics for Au/Poly(vinylidene fluoride-trifluoroethylene)/Au metal-insulator-metal (MIM) device. Landau free energy expression for electric field in terms of polarization is also implemented in MATLAB to produce the polarization hysteresis curves of monocrystalline and polycrystalline ferroelectrics. The main drawback of previous models was their inability to predict polarization saturation at the same electric field limits as compared with measurements taken from a recently fabricated ferroelectric capacitor. A new model for ferroelectric polarization hysteresis based on curve fitting algorithm is derived that forces the polarization to be saturated at the desired electric field. The MATLAB simulation of this model and the experimental hysteresis is compared which shows an excellent level of agreement. The capacitance hysteresis of the ferroelectric capacitor is also analyzed using the MATLAB simulation. The new polarization hysteresis model that uses four-point fit method is used to derive the mathematical expression for large-signal capacitance. Landau-Khalatnikov kinetic equation is used for deriving mathematical expression for small-signal capacitance. The capacitance simulation results agreed fairly well with physical measurements from a Au-P(VDF-TrFE)-Au capacitor

Power System Stability Analysis Using Wide Area Measurement System

Advances in wide area measurement systems have transformed power system operation from simple visualization, state estimation, and post-mortem analysis tools to real-time protection and control at the systems level. Transient disturbances (such as lightning strikes) exist only for a fraction of a second but create transient stability issues and often trigger cascading type failures. The most common practice to prevent instabilities is with local generator out-of-step protection. Unfortunately, out-of-step protection operation of generators may not be fast enough, and an instability may take down nearby generators and the rest of the system by the time the local generator relay operates. Hence, it is important to assess power system stability over transmission lines as soon as the transient instability is detected instead of relying on purely localized out-of-step protection in generators. This thesis proposes a synchrophasor-based out-of-step prediction methodology at the transmission line level using wide area measurements from optimal phasor measurement unit (PMU) locations in the interconnected system. Voltage and current measurements from wide area measurement systems (WAMS) are utilized to find the swing angles. The proposed scheme was used to predict the first swing out-of-step condition in a Western Systems Coordinating Council (WSCC) 9 bus power system. A coherency analysis was first performed in this multi-machine system to determine the two coherent groups of generators. The coherent generator groups were then represented with a two-machine equivalent system, and the synchrophasor-based out-of-step prediction algorithm then applied to the reduced equivalent system. The coherency among the group of generators was determined within 100 ms for the contingency scenarios tested. The proposed technique is able to predict the instability 141.66 to 408.33 ms before the system actually reaches out-of-step conditions. The power swing trajectory is either a steady-state trajectory, monotonically increasing type (when the system becomes unstable), or oscillatory type (under stable conditions). Un- der large disturbance conditions, the swing could also become non-stationary. The mean and variance of the signal is not constant when it is monotonically increasing or non-stationary. An autoregressive integrated (ARI) approach was developed in this thesis, with differentiation of two successive samples done to make the mean and variance constant and facilitate time series prediction of the swing curve. Electromagnetic transient simulations with a real-time digital simulator (RTDS) were used to test the accuracy of the proposed algorithm with respect to predicting transient in- stability conditions. The studies show that the proposed method is computationally efficient and accurate for larger power systems. The proposed technique was also compared with a conventional two blinder technique and swing center voltage method. The proposed method was also implemented with actual PMU measurements from a relay (General Electric (GE) N60 relay). The testing was carried out with an interface between the N60 relay and the RTDS. The WSCC 9 bus system was modeled in the simulator and the analog time signals from the optimal location in the network communicated to the N60 relay. The synchrophasor data from the PMUs in the N60 were used to back-calculate the rotor angles of the generators in the system. Once the coherency was established, the swing curves for the coherent group of generators were found from time series prediction (ARI model). The test results with the actual PMUs match quite well with the results obtained from virtual PMU-based testing in the RTDS. The calculation times for the time series prediction are also very small. This thesis also discusses a novel out-of-step detection technique that was investigated in the course of this work for an IEEE Power Systems Relaying Committee J-5 Working Group document using real-time measurements of generator accelerating power. Using the derivative or second derivative of a measurement variable significantly amplifies the noise term and has limited the actual application of some methods in the literature, such as local measurements of voltage or voltage deviations at generator terminals. Another problem with the voltage based methods is taking an average over a period; the intermediate values cancel out and, as a result, just the first and last sample values are used to find the speed. This effectively means that the sample values in between are not used. The first solution proposed to overcome this is a polynomial fitting of the points of the calculated derivative points (to calculate speed). The second solution is the integral of the accelerating power method (this eliminates taking a derivative altogether). This technique shows the direct relationship of electrical power deviation to rotor acceleration and the integral of accelerating power to generator speed deviation. The accelerating power changes are straightforward to measure and the values obtained are more stable during transient conditions. A single machine infinite bus (SMIB) system was used for the purpose of verifying the proposed local measurement based method

Comparison of Bipolar Diathermy with Thunder-beat Device in Surgical Outcome of Tonsillectomy

Background:. To compare the thunder-beat device with bipolar diathermy in surgical outcome of tonsillectomy. Methods: In this prospective study 75 patients who underwent tonsillectomy on one side using thunder beat device and on the other side using bipolar diathermy, were included . The intra-operative blood loss, operative time, post-operative pain and post-operative haemorrhage were taken for analysis in both the surgical procedures. Results: Among the seventy five patients, the age groups ranged from 19-36 years with mean age 25.36+/-5.54 years. Out of 75 patients, 21 were male and 54 were female.The comparison of operation time and intra-operative blood loss between thunder- beat and bipolar diathermy showed statistically significant differences. The comparison of pain score showed statistically significant result with better pain results in bipolar diathermy whereas the secondary haemorrhage was common in thunder beat device. Conclusion: The thunder-beat use in tonsillectomies is less time consuming with decreased intra-operative blood loss. But, the post-operative pain is more as compared to bipolar diathermy. Though, it is safe and effective in performing tonsillectomy but its cost is the main drawback for its regular use

Askin's Tumor: A Dual Case Study

Askin's tumor is a rare tumor arising from the chest wall. It is a subset of Ewing sarcoma characterized histologically by the presence of small round blue cells. It is a highly malignant tumor with guarded prognosis, which is dependent upon the extension of tumor at the time of diagnosis. A dual paper of Askin's tumors in young boys is being presented here

Taking a Community Biodiversity Management Approach to ABS in Local Communities: The Nepal Experience

Although the International Regime on Access and Benefit-Sharing (IRABS) is a global legal instrument, the provisions of the Convention on Biological Diversity (CBD) and Bonn Guidelines shows implementation of the international regime should start at the local community. While an international instrument for regulating ABS is required to generate the incentive for conservation of rapidly depleting biodiversity, the execution should effectively guarantee the recognition of the local communities and indigenous people as the true custodian of the genetic resources, and their right to make decisions on documentation, conservation, development and sustainable use and access to and benefit sharing

Light suppression of nitrate reductase activity in seedling and young plant tissues

Light is often reported to enhance plant nitrate reductase (NR) activity; we have identified a context in which light strongly suppresses NR activity. In vitro NR activity measurements of laboratory-grown seedlings showed strong suppression of nitrate-induced NR activity in cotyledon, hypocotyl, and root tissues of Ipomoea hederacea (L.) Jacquin; robust NR activity accumulated in nitrate-induced tissues in the dark, but was absent or significantly reduced in tissues exposed to light during the incubation. The suppressive mechanism appears to act at a point after nitrate perception; tissues pre-incubated with nitrate in the light were potentiated and developed NR activity more rapidly than nitrate-induced tissues not so pre-exposed. Suppression was affected by moderate to low light levels under full-spectrum light sources and by single-wavelength red, green, and blue sources. The suppression phenomenon persisted in early (first through fourth) leaves of glasshouse plants grown in soil, and in artificially rejuvenated cotyledons. Collectively these observations suggest a link between light perception and NR regulation that remains to be fully characterized

Development of an EMG-controlled mobile robot

This paper presents the development of a Robot Operating System (ROS)-based mobile robot control using electromyography (EMG) signals. The proposed robot’s structure is specifically designed to provide modularity and is controlled by a Raspberry Pi 3 running on top of an ROS application and a Teensy microcontroller. The EMG muscle commands are sent to the robot with hand gestures that are captured using a Thalmic Myo Armband and recognized using a k-Nearest Neighbour (k-NN) classifier. The robot’s performance is evaluated by navigating it through specific paths while solely controlling it through the EMG signals and using the collision avoidance approach. Thus, this paper aims to expand the research on the topic, introducing a more accurate classification system with a wider set of gestures, hoping to come closer to a usable real-life applicatio