State Estimation in Power Distribution Network Operation

The majority of power distribution networks were planned, designed and built as a passive but reliable link between the bulk power transmission point and the in- dividual customer. Enough latent capacity in cables and lines to accommodate anticipated demand growth was allowed and so the system was left unmonitored. Following the signicant development in business regulation, technology evolutions and various government policies towards low carbon renewable generation, it has become necessary to operate the distribution systems efficiently and in a controlled manner. This obviously needs state estimation for network control functions. State estimation is the core function of any energy management system in transmission networks. However little emphasis have been given to the distribution system state estimation, mainly due to the absence of adequate network measurements and also lack of rigorous methodology and tools that could be applied on restricted measure- ments. The scarcity of measured information offers formidable challenge to the state estimator to provide reasonably meaningful estimates of the system states. This introduces bottlenecks in carrying out a range of substation and feeder automa- tion tasks that rely on the quality of the state estimator and opens up many issues like modelling of demand, identification of suitable estimator and placement of new measurements etc. This thesis attempts to address these issues. Thus, the objec- tives of this research are to model the demand as pseudo measurement, identify the state estimation methodology to suite the distribution scenarios and find the effec- tive locations for placing measurements for improving the quality of the estimated quantities. The thesis discusses in detail the criterion for identifying suitable solvers for the distribution system state estimation and stochastic optimisation methods to model the demand. It also discusses a probabilistic technique for identifying effective locations for measurement placement. The robustness of the state estimation algorithm against changes in network topology has been addressed in a statistical framework. All the concepts have been demonstrated on 12-bus radial and 95-bus UKGDS network models

Twin Telescope observations of the Sun at Kodaikanal Observatory

We report the design, fabrication and installation of a 'Twin Telescope' at Kodaikanal Observatory intended to augment the ongoing synoptic observations of the Sun that has been carried out since 1904. The telescope uses a 15 cm objective capable of taking Ca-K line filtergrams and photoheliograms in continuum of the full disk of the Sun simultaneously, at a frequency of 0.1 Hz using 2kx2k format CCD cameras. The telescope has been in operation since February 2008 and images are being obtained at a cadence of 5 min during normal observing periods. In case of solar activity, images of the active regions can be taken at a frequency of 1 Hz by restricting the field of view and spatial resolution. In this paper, we describe the telescope, instruments, image acquisition, data calibration and image processing. We also discussed a method of determining the network element and plage area index. The preliminary results show that while the network element covers about 30% of the disk, the percentage of the network element area index varies marginally with the seeing conditions during the day.Comment: 17 pages, 10 Figures, to appear in the 2012 March issue of the Bulletin of the Astronomical Society of Indi

Mechanistic principles of antisense targets for the treatment of Spinal Muscular Atrophy

Spinal muscular atrophy (SMA) is a major neurodegenerative disorder of children and infants. SMA is primarily caused by low levels of SMN protein owing to deletions or mutations of the SMN1 gene. SMN2, a nearly identical copy of SMN1, fails to compensate for the loss of the production of the functional SMN protein due to predominant skipping of exon 7. Several compounds, including antisense oligonucleotides (ASOs) that elevate SMN protein from SMN2 hold the promise for treatment. An ASO-based drug currently under Phase III clinical trial employs intronic splicing silencer N1 (ISS-N1) as its target. Cumulative studies on ISS-N1 reveal a wealth of information with significance to the overall therapeutic development for SMA. Here, the authors summarize the mechanistic principles behind various antisense targets currently available for SMA therapy

How the discovery of ISS-N1 led to the first medical therapy for spinal muscular atrophy

Spinal muscular atrophy (SMA), a prominent genetic disease of infant mortality, is caused by low levels of survival motor neuron (SMN) protein owing to deletions or mutations of the SMN1 gene. SMN2, a nearly identical copy of SMN1 present in humans, cannot compensate for the loss of SMN1 due to predominant skipping of exon 7 during pre-mRNA splicing. With the recent FDA approval of nusinersen (Spinraza™), the potential for correction of SMN2 exon 7 splicing as a SMA therapy has been affirmed. Nusinersen is an antisense oligonucleotide that targets intronic splicing silencer N1 (ISS-N1) discovered in 2004 at the University of Massachusetts Medical School. ISS-N1 has emerged as the model target for testing the therapeutic efficacy of antisense oligonucleotides using different chemistries as well as different mouse models of SMA. Here we provide a historical account of events that led to the discovery of ISS-N1 and describe the impact of independent validations that raised the profile of ISS-N1 as one of the most potent antisense targets for the treatment of a genetic disease. Recent approval of nusinersen provides a much-needed boost for antisense technology that is just beginning to realize its potential. Beyond treating SMA, the ISS-N1 target offers myriad potentials for perfecting various aspects of the nucleic-acid-based technology for the amelioration of the countless number of pathological conditions

Pressure-Induced Topological Phase Transitions in CdGeSb2_2 and CdSnSb2_2

Topological quantum phase transitions (TQPTs) in a material induced by external perturbations are often characterized by band touching points in the Brillouin zone. The low-energy excitations near the degenerate band touching points host different types of fermions while preserving the topological protection of surface states. An interplay of different tunable topological phases offers an insight into the evolution of the topological character. In this paper, we study the occurrence of TQPTs as a function of hydrostatic pressure in CdGeSb$_2$ and CdSnSb$_2$ chalcopyrites, using the first-principles calculations. At ambient pressure, both materials are topological insulators having a finite band gap with inverted order of Sb-$s$ and Sb-$p_x$,$p_y$ orbitals of valence bands at the $\Gamma$ point. On the application of hydrostatic pressure the band gap reduces, and at the critical point of the phase transition, these materials turn into Dirac semimetals. On further increasing the pressure beyond the critical point, the band inversion is reverted making them trivial insulators. The pressure-induced change in band topology from non-trivial to trivial phase is also captured by L\"{u}ttinger model Hamiltonian calculations. Our model demonstrates the critical role played by a pressure-induced anisotropy in frontier bands in driving the phase transitions. These theoretical findings of peculiar coexistence of multiple topological phases in the same material provide a realistic and promising platform for the experimental realization of the TQPT.Comment: 7 pages, 7 figure

A short antisense oligonucleotide masking a unique intronic motif prevents skipping of a critical exon in spinal muscular atrophy

Spinal muscular atrophy (SMA) is the leading genetic cause of infant mortality. Most SMA cases are associated with the low levels of SMN owing to deletion of Survival Motor Neuron 1 (SMN1). SMN2, a nearly identical copy of SMN1, fails to compensate for the loss of SMN1 due to predominant skipping of exon 7. Hence, correction of aberrant splicing of SMN2 exon 7 holds the potential for cure of SMA. Here we report an 8-mer antisense oligonucleotide (ASO) to have a profound stimulatory response on correction of aberrant splicing of SMN2 exon 7 by binding to a unique GC-rich sequence located within intron 7 of SMN2. We confirm that the splicing-switching ability of this short ASO comes with a high degree of specificity and reduced off-target effect compared to larger ASOs targeting the same sequence. We further demonstrate that a single low nanomolar dose of this 8-mer ASO substantially increases the levels of SMN and a host of factors including Gemin 2, Gemin 8, ZPR1, hnRNP Q and Tra2-β1 known to be down regulated in SMA. Our findings underscore the advantages and unmatched potential of very short ASOs in splicing modulation in vivo

Multiple Triple-Point Fermions in Heusler Compounds

Using the density functional theoretical calculations, we report a new set of topological semimetals X$_{2}$YZ (X = \{Cu, Rh, Pd, Ag, Au, Hg\}, Y = \{Li, Na, Sc, Zn, Y, Zr, Hf, La, Pr, Pm, Sm, Tb, Dy, Ho, Tm\} and Z =\{Mg, Al, Zn, Ga, Y, Ag, Cd, In, Sn, Ta, Sm\}), which show the existence of multiple topological triple point fermions along four independent $C_{3}$ axes. These fermionic quasiparticles have no analogues elementary particle in the standard model. The angle-resolved photoemission spectroscopy is simulated to obtain the exotic topological surface states and the characteristic Fermi arcs. The inclusion of spin-orbit coupling splits the triple-point into two Dirac points. The triple-point fermions are exhibited on the easily cleavable (111) surface and are well separated from the surface $\bar{\Gamma}$ point, allowing them to be resolved in the surface spectroscopic techniques. This intermediate linearly dispersive degeneracy between Weyl and Dirac points may offer prospective candidates for quantum transport applications

Antisense oligonucleotide mediated therapy of spinal muscular atrophy

Spinal muscular atrophy (SMA) is the leading genetic cause of infant mortality. SMA results from deletions or mutations of survival motor neuron 1 (SMN1), an essential gene. SMN2, a nearly identical copy, can compensate for SMN1 loss if SMN2 exon 7 skipping is prevented. Among the many cis-elements involved in the splicing regulation of SMN exon 7, intronic splicing silencer N1 (ISS-N1) has emerged as the most effective target for an antisense oligonucleotide (ASO)-mediated splicing correction of SMN2 exon 7. Blocking of ISS-N1 by an ASO has been shown to fully restore SMN2 exon 7 inclusion in SMA patient cells as well as in vivo. Here we review how ISS-N1 targeting ASOs that use different chemistries respond differently in the various SMA mouse models. We also compare other ASO-based strategies for therapeutic splicing correction in SMA. Given that substantial progress on ASO-based strategies to promote SMN2 exon 7 inclusion in SMA has been made, and that similar approaches in a growing number of genetic diseases are possible, this report has wide implications

Feminism and Husband-Wife Relationship in Society in Shobha De Novels\u27

Shobha De is a wonderful writer because of her extraordinary ability to communicate about extremely delicate aspects of the human condition. She has a unique ability to convey the complexities of interpersonal interactions, particularly those between men and women. Some in India with more conservative views have spoken out against her openness on the subject of sexuality. People are aware of some of her many qualities, but on the whole, they have no idea that she is a complex, multifaceted individual who can deftly juggle a wide range of skills. Traditional readers\u27 opinions on the subject matter of her literature are the last thing you should consider, in my view, so don\u27t bother listening to them. It\u27s likely due to her rising widespread renown as a writer of imaginative prose. Most of her fans like her for two reasons: the content she covers and the unique way she presents it. This study aims to analyze how Shobha De approaches feminist concerns in her writing, focusing on Snapshots in particular. These females have the moxie and good judgement to keep going strong as a couple. Asha Rani and Akshay Arora\u27s romance in Starry Nights (1991) is a great illustration of this sort of pairing. Men don\u27t care about women\u27s uniqueness, compassion, or perspective, but these women want more freedom to make decisions for themselves. They act irresponsibly, such as having extramarital affairs to vent their anger, or they may even do so