600 research outputs found
Perifoveal exudative vascular anomalous complex-like lesion as a complication of prepapillary arterial loops
No full textPerifoveal exudative vascular anomalous complex (PEVAC) and its expanded spectrum have been recently elucidated by multimodal imaging. Although there is some clarity about its characteristic features and natural history, the cause remains unknown. Herein, the authors describe a hitherto unknown association with prepapillary arterial loops and suggest a possible hypothesis for the development of a PEVAC-like lesion and its response to treatment with thermal laser. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:974-978.]
Blockchain technology-based fake news detection : Applications and future research directions
No full textFor the past few years, the topic of “fake news” has been consistently featured prominently in the news headlines. Fake news is a serious problem that jeopardises a society’s political, social, democratic, and economic institutions. The usage of the Internet and social media has exacerbated the situation. Technology plays a significant part in the dissemination of fake news, but it may also play a significant role in combating fake news. The blockchain technology (BCT) is a new form of disruptive technology that has captured the interest of a significant number of researchers due to the exceptional security characteristics it possesses and the transparency it offers. BCT ensures the provenance, authenticity and traceability of data by producing a record of transactions that is open to inspection, cannot be altered, and can be independently verified. The purpose of this chapter is to investigate the use of BCT in the fight against fake news. To do so, we will first examine the characteristics of blockchain technology, and then we will discuss the difficulties that BCT faces. In addition, a number of suggestions are provided as a roadmap for future researchers on topics that will need to be addressed in order to combat the spread of fake news
Adsorption of free floating DNA and antimicrobial resistance genes out of wastewater effluents by sewage-based biochar and iron-oxide-coated sands
No full textThe presence of extracellular DNA (eDNA) containing antibiotic resistance genes in the treated wastewater effluents can contribute to the spread of antimicrobial resistance (AMR) among receiving waters. The removal of cell associated antibiotic resistance genes (ARGs) has been widely studied using advance treatments. However, these treatments were not evaluated for cell free or extracellular ARGs resulting from the cell lysis or secretion during metabolic activities. eDNA is known to well adsorb onto clay, suspended particles and other soil components. Thus, in this research the potential and the main mechanisms involved in the removal of eDNA by adsorption onto sewage-based biochar and iron-oxide-coated sands has been studied.Master of Science in Civil Engineering and in Environmental EngineeringCivil Engineering | Environmental Engineerin
Arsenic Removal by Adsorption and Multilayer Sand Filtration
No full textThe presence of Arsenic in the groundwater, and eventually in the drinking water is a serious problem in many of the Asian countries. Due to it high toxicity to its removal is very essential. There are many removal technologies for the removal of arsenic such as adsorption, coagulation-filtration, membrane filtration, ion exchange and precipitation. Adsorption is one such technology which is mainly used as it’s a very simple technique. the extent of adsorption is affected by pH, nature of the adsorbent, surface area of the adsorbents. Iron is widely used for the removal of Arsenic from groundwater. The iron which is present in dissolved form in groundwater needs to first get oxidised to hydrous ferric oxides as flocs which provide adsorption sites for arsenic. In this study the effect of pH and Iron dosage on the arsenic removal by adsorption with the available dissolved Iron in the groundwater. The effect of pH on arsenic removal by floc formation of iron with a series of Jar tests were done for Arsenite and Arsenate. Also, the removal of arsenic in a multilayer sand bed (3 layers with Anthracite, Sand and Garnet) was evaluated at three different pH. It was found that pH plays a very important role on Arsenic removal. Arsenite removal was increased with pH whereas Arsenate removal decreased with increase in pH. At pH 5 and at high Fe concentrations, the removal decreases but the effective iron or the iron that flocculated to greater than 0.45µm was quite similar. This was also seen in the particle counter analysis. Iron concentration of 5mg/l was enough to remove Arsenate upto 90% whereas Arsenite needed higher doses of upto 20mg/l to reach 90%. Clear increase in the flocculation was observed in particle counts with the increase of iron concentration. Before the dosing of Iron Arsenic oxidation was seen in the filter bed maybe due to the presence of Arsenic Oxidising Bacteria (AOB). High oxidation efficiency was seen Sand and Garnet layer. The oxidation of Arsenite to Arsenate before dosing iron in the filter was less at pH 8. High resistance was observed in the filter bed within 3 days after backwashing although the removal was quite stable in the three days. After dosing of Iron, high removal of arsenic was seen in Anthracite layer due to the high adsorption of Iron in the Anthracite layer.CIE 5050-0
Prevalence and severity of periodontal disease in type 2 diabetes mellitus (non-insulin-dependent diabetes mellitus) patients in Bangalore city: An epidemiological study
No full textBackground: Our objective was to study the prevalence and severity of periodontal disease in type 2 diabetes mellitus (DM) patients in Bangalore city. Materials and Methods : Four hundred and eight type 2 DM patients (Study Group) and 100 non-diabetic patients (Control Group) among the age group of 35-75 years were included in the study. The study group was divided based on Glycated hemoglobin levels into well, moderately and poorly controlled. Relevant information regarding age, oral hygiene habits and personal habits was obtained from the patients. Diabetic status and mode of anti-diabetic therapy of the study group was obtained from the hospital records with consent from the patient. Community periodontal index (CPI) was used to assess the periodontal status. The results were statistically evaluated. Results : The mean CPI score and the number of missing teeth was higher in diabetics compared with non-diabetics, and was statistically significant ( P=0.000), indicating that prevalence and extent of periodontal disease was more frequent and more severe in diabetic patients. The risk factors like Glycated hemoglobin, duration of diabetes, fasting blood sugar, personal habits and oral hygiene habits showed a positive correlation with periodontal destruction, whereas mode of anti-diabetic therapy showed a negative correlation according to the multiple regression analysis. The odds ratio of a diabetic showing periodontal destruction in comparison with a non-diabetic was 1.97, 2.10 and 2.42 in well, moderately and poorly controlled diabetics, respectively. Conclusion : Our study has made an attempt to determine the association between type 2 DM (NIDDM) and periodontal disease in Bangalore city. It was found that type 2 DM (non-insulin-dependent diabetes mellitus [NIDDM]) subjects manifested relatively higher prevalence and severity of periodontal disease as compared with non-diabetics
Synaptic mechanisms of OPRM1 A118G single nucleotide polymorphism in human neurons
No full textAssociation of the non-synonymous single nucleotide polymorphism (SNP) rs1799971 in OPRM1 to drug dependence and alcohol abuse suggests it may have a functional consequence in altering receptor signaling in the brain. The A118G SNP causes a switch of asparagine (N) at position 40 of the mu-opioid receptor (MOR) to aspartate (D). To dissect the underlying neural and synaptic basis of the N40D MOR variant, we generated human GABAergic induced neuronal (iN) cells from induced pluripotent stem (iPS) cells of donors homozygous for either the major (N40) or minor (D40) alleles of the MOR. We found that the subject-derived iN cells exhibit mature neuronal properties such as action potential firing and neuronal excitability and express functional MORs. Interestingly, upon MOR activation by the agonist DAMGO, D40 MOR iN cells exhibit consistently stronger suppression of spontaneous inhibitory postsynaptic currents (sIPSCs) than N40 MOR iN cells across multiple subjects. To mitigate the complexity of diverse genetic backgrounds of the subject iN cells derived from multiple human subjects, we employed CRISPR/Cas9 genome-editing to generate two pairs of isogenic human pluripotent stem cell lines. Remarkably, the synaptic regulation of MOR activation in the isogenic lines recapitulate those of neurons generated from different individuals, i.e. stronger suppression in D40 MOR carrying human neuronal cells by MOR activation. We further determined that the increased sensitivity of D40 iN cells to DAMGO was caused by a more robust inhibition of excitability and synaptic release by DAMGO in D40 MOR expressing neurons. Additionally, we found that the N40D SNP influences the development of long-term tolerance at the MOR. Specifically, D40 iN cells are unable to develop adaptive changes in synaptic function unlike N40 iN cells following long-term mu opioid receptor activation by DAMGO. This study utilizes patient-specific iPS cells as well as a gene edited isogenic neurons to advance our understanding of the fundamental synaptic alterations associated with OPRM1 A118G in a human neuronal context.Ph.D.Includes bibliographical referencesby Apoorva Haliker
Radiomics of Biliary Tumors: A Systematic Review of Current Evidence
No full textBiliary tumors are rare diseases with major clinical unmet needs. Standard imaging modalities provide neither a conclusive diagnosis nor robust biomarkers to drive treatment planning. In several neoplasms, texture analyses non-invasively unveiled tumor characteristics and aggressiveness. The present manuscript aims to summarize the available evidence about the role of radiomics in the management of biliary tumors. A systematic review was carried out through the most relevant databases. Original, English-language articles published before May 2021 were considered. Three main outcome measures were evaluated: prediction of pathology data; prediction of survival; and differential diagnosis. Twenty-seven studies, including a total of 3605 subjects, were identified. Mass-forming intrahepatic cholangiocarcinoma (ICC) was the subject of most studies (n = 21). Radiomics reliably predicted lymph node metastases (range, AUC = 0.729–0.900, accuracy = 0.69–0.83), tumor grading (AUC = 0.680–0.890, accuracy = 0.70–0.82), and survival (C-index = 0.673–0.889). Textural features allowed for the accurate differentiation of ICC from HCC, mixed HCC-ICC, and inflammatory masses (AUC > 0.800). For all endpoints (pathology/survival/diagnosis), the predictive/prognostic models combining radiomic and clinical data outperformed the standard clinical models. Some limitations must be acknowledged: all studies are retrospective; the analyzed imaging modalities and phases are heterogeneous; the adoption of signatures/scores limits the interpretability and applicability of results. In conclusion, radiomics may play a relevant role in the management of biliary tumors, from diagnosis to treatment planning. It provides new non-invasive biomarkers, which are complementary to the standard clinical biomarkers; however, further studies are needed for their implementation in clinical practice
LoRaWAN Class B Multicast Scalability
No full textLoRaWAN has emerged as a popular IoT commu- nications technology. It comes with three classes of operation: A, B, and C. Although many IoT use-cases, like Firmware-over- the-Air updates, require multicast, Class A cannot be used for that purpose. Class C can, but consumes a lot of energy. This leaves Class B. In this paper, we investigate Class B multicast and its scalability properties. Issues like multicast member capacity, beacon blocking, and beacon collisions are highlighted, and several approaches to mitigate them are proposed: (1) “Ping-Slot Relaying,” to allow for more multicast members, (2) a scheduling approach indicating when to best send multicast packets, and (3) “Dynamic Region Formation” to coordinate the sending of beacons over multiple gateways. The proposed solutions do not require any modifications to the LoRaWAN protocol.Virtual/online event due to COVID-19 accepted author manuscriptEmbedded System
Generalizations Of The Quantum Search Algorithm
No full textQuantum computation has attracted a great deal of attention from the scientific community in recent years. By using the quantum mechanical phenomena of superposition and entanglement, a quantum computer can solve certain problems much faster than classical computers. Several quantum algorithms have been developed to demonstrate this quantum speedup. Two important examples are Shor’s algorithm for the factorization problem, and Grover’s algorithm for the search problem. Significant efforts are on to build a large scale quantum computer for implementing these quantum algorithms.
This thesis deals with Grover’s search algorithm, and presents its several generalizations that perform better in specific contexts. While writing the thesis, we have assumed the familiarity of readers with the basics of quantum mechanics and computer science. For a general introduction to the subject of quantum computation, see [1].
In Chapter 1, we formally define the search problem as well as present Grover’s search algorithm [2]. This algorithm, or more generally the quantum amplitude amplification algorithm [3, 4], drives a quantum system from a prepared initial state (s) to a desired target state (t). It uses O(α-1 = | (t−|s)| -1) iterations of the operator g = IsIt on |s), where { IsIt} are selective phase inversions selective phase inversions of the corresponding states. That is a quadratic speedup over the simple scheme of O(α−2) preparations of |s) and subsequent projective measurements. Several generalizations of Grover’s algorithm exist.
In Chapter 2, we study further generalizations of Grover’s algorithm. We analyse the iteration of the search operator S = DsI t on |s) where Ds is a more general transformation than Is, and I t is a selective phase rotation of |t) by angle . We find sufficient conditions for S to produce a successful quantum search algorithm.
In Chapter 3, we demonstrate that our general framework encapsulates several previous generalizations of Grover’s algorithm. For example, the phase-matching condition for the search operator requires the angles and and to be almost equal for a successful quantum search. In Kato’s algorithm, the search operator is where Ks consists of only single-qubit gates, which are easier to implement physically than multi-qubit gates. The spatial search algorithms consider the search operator where is a spatially local operator and provides implementation advantages over Is. The analysis of Chapter 2 provides a simpler understanding of all these special cases.
In Chapter 4, we present schemes to improve our general quantum search algorithm, by controlling the operators through an ancilla qubit. For the case of two dimensional spatial search problem, these schemes yield an algorithm with time complexity . Earlier algorithms solved this problem in time steps, and it was an open question to design a faster algorithm. The schemes can also be used to find, for a given unitary operator, an eigenstate corresponding to a specified eigenvalue.
In Chapter 5, we extend the analysis of Chapter 2 to general adiabatic quantum search. It starts with the ground state |s) of an initial Hamiltonian Hs and evolves adiabatically to the target state |t) that is the ground state of the final Hamiltonian The evolution uses a time dependent Hamiltonian HT that varies linearly with time . We show that the minimum excitation gap of HT is proportional to α. Also, the ground state of HT changes significantly only within a very narrow interval of width around the transition point, where the excitation gap has its minimum. This feature can be used to reach the target state (t) using adiabatic evolution for time
In Chapter 6, we present a robust quantum search algorithm that iterates the operator on |s) to successfully reach |t), whereas Grover’s algorithm fails if as per the phase-matching condition. The robust algorithm also works when is generalized to multiple target states. Moreover, the algorithm provides a new search Hamiltonian that is robust against certain systematic perturbations.
In Chapter 7, we look beyond the widely studied scenario of iterative quantum search algorithms, and present a recursive quantum search algorithm that succeeds with transformations {Vs,Vt} sufficiently close to {Is,It.} Grover’s algorithm generally fails if while the recursive algorithm is nearly optimal as long as , improving the error tolerance of the transformations.
The algorithms of Chapters 6-7 have applications in quantum error-correction, when systematic errors affect the transformations The algorithms are robust as long as the errors are small, reproducible and reversible. This type of errors arise often from imperfections in apparatus setup, and so the algorithms increase the flexibility in physical implementation of quantum search.
In Chapter 8, we present a fixed-point quantum search algorithm. Its state evolution monotonically converges towards |t), unlike Grover’s algorithm where the evolution passes through |t) under iterations of the operator . In q steps, our algorithm monotonically reduces the failure probability, i.e. the probability of not getting |t), from . That is asymptotically optimal for monotonic convergence. Though the fixed-point algorithm is of not much use for , it is useful when and each oracle query is highly expensive.
In Chapter 9, we conclude the thesis and present an overall outlook
Weights of highest weight modules over Kac-Moody algebras
No full textIn this dissertation, broadly, we treat the weight-sets of arbitrary highest weight modules (uniformly) over all general complex Kac-Moody Lie algebras ,
achieving the below.
We obtain a uniform, explicit, cancellation-free and positive formula for the weight-sets of all highest weight modules (of all highest weights) over all Kac-Moody .
Interestingly, our formula for the weights of involves basic ingredients, namely the independent subsets in the Dynkin diagram of determined by , and nothing else!
Prior to our work, it seems that even for all (non-integrable) simple highest weight -modules - despite these being treated for over a half century - their weight-formulas were not known until a few years ago.
Namely, these were written-up in Khare [J. Alg. 2016] and Dhillon-Khare [Adv. Math. 2017 and J. Alg. 2022]; and our general formula recovers the formulas for simples in these papers.
Leaving out general Kac-Moody or even general semisimple settings, given an arbitrary highest weight module over or in particular , even in this case the weights of were not written down in the literature to the best of our knowledge.
More importantly, our weight-formula naturally drives us to introduce and study a finite family of ``higher order Verma modules" over Kac-Moody , for every highest weight and (any) collection of independent subsets in the Dynkin diagram of .
This family generalizes and includes: all Verma modules at zeroth order level, and the parabolic Verma modules (which were introduced and studied by Lepowsky, Kumar, Mathieu,... to name but a few) at first order level.
Importantly, our higher order Verma modules are crucial and universal for weight considerations:
their weight-sets (which are finitely many when we fix their highest weight) are pairwise disjoint and exhaust the weight-sets of all highest weight -modules.
In this thesis, we also initiate the study of the characters of these universal modules, by computing them via BGG-type resolutions in certain cases.
Next, a phenomenon in root systems which rewarded us with many applications on the weights side.
First, recall the partial sum property for Kac-Moody root systems: every root of is an ordered sum of simple roots such that each partial sum is also a root.
The course/journey to finding and proving our weight-formula mentioned above begins from proving a parabolic-generalization of this property, which we call as the parabolic partial sum property.
Given a subset of simple roots, it allows one to write any (positive) root involving some simple roots from as: an ordered sum of roots, in which each root involves exactly one simple root from (unit -height roots) and with each partial sum also being a root.
The parabolic partial sum property has been devised in order to obtain a ``minimal" description for the weights of all (non-integrable) highest weight simples, which was posed by Khare.
This thesis exhibits such minimal descriptions as an immediate application of the parabolic partial sum property;
in fact we will more strongly show this property at the level of Lie words for any general Lie algebra graded over any free abelian semigroup.
There is also another generalization of the partial sum property due to Khare and Kumar for highest weight simples in finite type, which we extend to the Kac-Moody setting in this thesis.
There is another notable application of the parabolic partial sum property shown in this thesis. Chari and her coauthors [Adv. Math. 2009 and J. Geom. Phys. 2011] introduced and studied certain combinatorial subsets called weak faces and -closed subsets of finite root systems. This is in order to construct Koszul algebras, study Kirillov-Reshetikhin modules over specializations of quantum affine algebras, and also to classify nilpotent ideals in the parabolic Lie subalgebras of finite type , etc.
These subsets (say subsets of a set ) are some discrete analogues/ generalizations of the faces for convex sets (the faces of the convex hull of ).
In this thesis, we are concerned with such subsets of a weight-set, generalizing the faces for convex hulls of weight-sets.
Using the weak faces for weight-sets of finite-dimensional simples (in finite type) Khare extended the aforementioned results of Chari et al.
Motivated by the applications of these two modern notions to representation theory, we completely classify the weak faces and -closed subsets of weights of all highest weight modules (again uniformly) over all Kac-Moody ; extending and completing the partial classification results of Chari, Khare, and their co-authors from finite type.
We more strongly show that both these notions are the same as the weights falling on the faces, for the convex hulls of these weight-sets.
This shows the equivalence of these two notions, to the classical faces for the convex hulls of weights (which have been pursued from the 1960s).NBHM Ph.D. Fellowship (Ref. No. 2/39(2)/2016/NBHM/R&D-II/11431) and by a Swarnajayanti Fellowship from the DST and SERB (Govt. of India)
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