305 research outputs found
First person – Gaurav Barve
No full textABSTRACT
First Person is a series of interviews with the first authors of a selection of papers published in Journal of Cell Science, helping early-career researchers promote themselves alongside their papers. Gaurav Barve is the first author on ‘Septins are involved at the early stages of macroautophagy in S. cerevisiae’, published in Journal of Cell Science. Gaurav is a PhD student in the laboratory of Ravi Manjithaya at Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, India, investigating the role of septins in autophagy.</jats:p
Linguistic representations of visual events
No full textThis thesis explores the nature of linguistic representations that correspond to verbal descriptions of events. In two experiments, participants watched captioned videos and decided whether the captions accurately described the videos. In the videos, two geo-metric shapes moved around the screen. [In half of the trials, the geometric shapes had "eyes."] The verbs used to describe the shapes' actions were either source-to-goal verbs (chase, follow, trail ) or goal-to-source verbs (flee, lead, guide). Sometimes the captions were active sentences (e.g., The circle is chasing the square) and sometimes passive sentences (The square is chased by the circle). Analyses of participants' reaction times indicate that the level of linguistic and visual detail encoded reflected the complexity of the task participants had to perform. These results are consistent with "good enough" models of language processing (e.g., Ferreira and Henderson (2007)) in which people process sentences heuristically or syntactically depending on the nature of the task they must perform.M.S.Includes bibliographical referencesby Gaurav Kharkwa
Semantic parsing using lexicalized well-founded grammars
No full textResearch in semantic parsing has focused on developing computational systems capable of simultaneously performing syntactic, i.e. structural, and semantic, i.e., meaning-based, analyses of given sentences. We present an implementation of a semantic parsing system using a constraint-based grammatical formalism called Lexicalized Well-Founded Grammars (LWFGs). LWFGs are a type of Definite Clause Grammars, and use an ontology-based framework to represent syntactico-semantic information in the form of compositional and interpretation constraints. What makes LWFGs particularly interesting is the fact that these are the only constraint-based grammars that are provably learnable. Furthermore, there exist tractable learning algorithms for LWFGs, which make these especially useful in resource-poor language settings. In this thesis, we present a revised parsing implementation for Lexicalized Well-Founded Grammars. Previous work implemented semantic parsers using Prolog, a declarative language, which is slow and does not allow for an easy extension to a stochastic parsing framework. Our implementation utilizes Python's Natural Language Toolkit which not only allows us to easily interface our work with the natural language processing community, but also allows for a future possibility of extending the parser to support broad-coverage and stochastic parsing.M.S.Includes bibliographical referencesby Gaurav Kharkwa
Altered Expression of the CB1 Cannabinoid Receptor in the Triple Transgenic Mouse Model of Alzheimer's Disease
No full textThe endocannabinoid system has gained much attention as a new potential pharmacotherapeutic target in various neurodegenerative diseases, including Alzheimer's disease (AD). However, the association between CB1 alterations and the development of AD neuropathology is unclear and often contradictory. In this study, brain CB1 mRNA and CB1 protein levels were analyzed in 3 × Tg-AD mice and compared to wild-type littermates at 2, 6 and 12 months of age, using in-situ hybridization and immunohistochemistry, respectively. Semiquantitative analysis of CB1 expression focused on the prefrontal cortex (PFC), prelimbic cortex, dorsal hippocampus (DH), basolateral amygdala complex (BLA), and ventral hippocampus (VH), all areas with high CB1 densities that are strongly affected by neuropathology in 3 × Tg-AD mice. At 2 months of age, there was no change in CB1 mRNA and protein levels in 3 × Tg-AD mice compared to Non-Tg mice in all brain areas analyzed. However, at 6 and 12 months of age, CB1 mRNA levels were significantly higher in PFC, DH, and BLA, and lower in VH in 3 × Tg-AD mice compared to wild-type littermates. CB1 immunohistochemistry revealed that CB1 protein expression was unchanged in 3 × Tg-AD at 2 and 6 months of age, while a significant decrease in CB1 receptor immunoreactivity was detected in the BLA and DH of 12-month-old 3 × Tg-AD mice, with no sign of alteration in other brain areas. The altered CB1 levels appear, rather, to be age-and/or pathology-dependent, indicating an involvement of the endocannabinoid system in AD pathology and supporting the ECS as a potential novel therapeutic target for treatment of AD
The role of endocannabinoid signaling in the molecular mechanisms of neurodegeneration in Alzheimer's disease
No full textAlzheimer's disease (AD) is the most common form of progressive neurodegenerative disease characterized by cognitive impairment and mental disorders. The actual cause and cascade of events in the progression of this pathology is not fully determined. AD is multifaceted in nature and is linked to different multiple mechanisms in the brain. This aspect is related to the lack of efficacious therapies that could slow down or hinder the disease onset/progression. The ideal treatment for AD should be able to modulate the disease through multiple mechanisms rather than targeting a single dysregulated pathway. Recently, the endocannabinoid system emerged as a novel potential therapeutic target to treat AD. In fact, exogenous and endogenous cannabinoids seem to be able to modulate multiple processes in AD, although the mechanisms that are involved are not fully elucidated. This review provides an update of this area. In this review, we recapitulate the role of endocannabinoid signaling in AD and the probable mechanisms through which modulators of the endocannabinoid system provide their effects, thus highlighting how this target might provide more advantages over other therapeutic targets
Aberrant insulin signaling in Alzheimer’s disease: current knowledge
No full textAlzheimer’s disease (AD) is the most common form of dementia affecting elderly people. AD is a multifaceted pathology characterized by accumulation of extracellular neuritic plaques, intracellular neurofibrillary tangles (NFTs) and neuronal loss mainly in the cortex and hippocampus. AD etiology appears to be linked to a multitude of mechanisms that have not been yet completely elucidated. For long time, it was considered that insulin signaling has only peripheral actions but now it is widely accepted that insulin has neuromodulatory actions in the brain. Insulin signaling is involved in numerous brain functions including cognition and memory that are impaired in AD. Recent studies suggest that AD may be linked to brain insulin resistance and patients with diabetes have an increased risk of developing AD compared to healthy individuals. Indeed insulin resistance, increased inflammation and impaired metabolism are key pathological features of both AD and diabetes. However, the precise mechanisms involved in the development of AD in patients with diabetes are not yet fully understood. In this review we will discuss the role played by aberrant brain insulin signaling in AD. In detail, we will focus on the role of insulin signaling in the deposition of neuritic plaques and intracellular NFTs. Considering that insulin mitigates beta-amyloid deposition and phosphorylation of tau, pharmacological strategies restoring brain insulin signaling, such as intranasal delivery of insulin, could have significant therapeutic potential in AD treatment
Framework for Investigating Functional Encryption
No full textThesis: M. Eng. in Computer Science and Engineering, Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2016.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from student-submitted PDF version of thesis.Includes bibliographical references (pages 95-102).In functional encryption, keys are associated with functions, and ciphertexts with messages. Decrypting a message with a key gives the evaluation of the associated function on that message. We look at bounded-collusion functional encryption, where the number of keys for which security is guaranteed is bounded, as it is possible to realize using standard building blocks. For such schemes we aim to understand their practicality for real-world applications. There are some theoretical constructions of functional encryption, but few implementations. We rectify this by creating the Framework for Investigating Functional Encryption (FIFE). FIFE includes the first implementations for Sahai and Seyalioglu's one-key scheme (CCS 2010), and Gorbunov, Vaikuntanathan, and Wee's bounded-collusion scheme (CRYPTO 2012), and is easily extendable. We used FIFE to evaluate their performance, and to measure the impact of using different public-key or secret-key encryption schemes, bounds on collusion, and security levels, for interesting classes of functions.by Gaurav Singh.M. Eng. in Computer Science and Engineerin
Design and analysis of fiber reinforced elastomeric enclosures with application in upper arm orthosis
No full textFiber Reinforced Elastomeric Enclosures (FREEs) are soft pneumatic actuators that deform in a predetermined fashion upon inflation. They are constructed using a hollow elastomeric cylinder reinforced by two families of helical fibers. This thesis analyzes the deformation behavior of FREEs by formulating a simple calculus of variations problem that involves constrained maximization of the enclosed volume. The model accurately captures the deformed shape (kinematics) for FREEs with any general fiber angle orientation, and its relation with actuation pressure, material properties and applied load (kinetostatics). The accuracy of the model is verified by benchmarking with existing models for a popular McKibben Pneumatic Artificial muscle (PAM) actuator with two helically wrapped families of fibers having equal and opposite orientations. For FREEs with any general fiber orientations and other novel designs with no prior literature, the model is validated experimentally. This model is deemed to be useful in the design synthesis of fiber reinforced elastomeric actuators for any desired motion and force requirement. FREEs are soft, compliant, and have a high power to weight ratio, which makes them suitable for orthotic devices for upper extremities.
The second part of the thesis considers the design and fabrication of a soft pneumatic sleeve for arm orthosis that uses a contracting FREE is shown. The sleeve is designed to reduce wrist loads in patients that use crutches for ambulation, thereby reducing the risk of joint injury. It forms an alternate load path between the crutch and the forearm, circumventing the wrist. The constricting force generated by the sleeve on the arm is analyzed by a string model and validated with experiments.Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2018-12-01The student, Gaurav Singh, accepted the attached license on 2016-12-06 at 16:32.The student, Gaurav Singh, submitted this Thesis for approval on 2016-12-06 at 16:48.This Thesis was approved for publication on 2016-12-07 at 08:36.DSpace SAF Submission Ingestion Package generated from Vireo submission #10459 on 2017-02-28 at 14:43:20Made available in DSpace on 2017-03-01T17:02:06Z (GMT). No. of bitstreams: 2
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Automated Passive Income from Stock Market Using Machine Learning and Big Data Analytics with Security Aspects-Retracted
No full textThis article is retracted:
Dear IJGASR Readers,
We regret to inform you that the article titled “Automated Passive Income from Stock Market Using Machine Learning and Big Data Analytics with Security Aspects,” published in Volume 2, Issue 4, 2023, with DOI https://doi.org/10.55938/ijgasr.v2i4.63 has been retracted.
The retraction is based on the request of the author, Dr. Gaurav Sharma, as it he along with his team is willing to expand his research further & want to publish with more research findings.
After thorough examination and review of the article, Editorial team has decided to consider request for the retraction/withdrawal of article
We apologize for any inconvenience or confusion this may have caused and reaffirm our commitment to upholding the integrity of our publication. We thank the author for bringing this matter to our attention and for taking the appropriate steps to retract the article.
Sincerely,
Editorial Team, IJGASR
Announcement: https://journals.icapsr.com/index.php/ijgasr/announcement/view/2
Studies of in-plane anisotropic physical properties in a-plane MgXZn1-XO
No full textMgxZn1-xO is a compound semiconductor material formed by alloying ZnO with MgO. The larger direct bandgap of MgxZn1-xO (~4eV for Mg0.33Zn0.67O) renders it useful as a barrier layer in ZnO/MgxZn1-xO based heterostructures and quantum wells. Conventionally grown c-oriented ZnO based quantum wells suffer from piezoelectric and spontaneous polarization fields, leading to lower quantum efficiency. Non-polar a-plane and m-plane ZnO based heterostructures avoid such problems. The non-polar MgxZn1-xO films also possess in-plane anisotropic optical, acoustic and electrical properties, useful for novel polarization sensitive devices. However, as-grown non-polar MgxZn1-xO films show rougher surface compared to its c-plane counterpart, introducing serious difficulty in growth of high quality heterostructures.
This dissertation addresses growth optimization and comprehensive characterization of a-plane MgxZn1-xO (0[less than or =] x [less than or =] 0.33) films on r-sapphire substrates using Metalorganic Chemical Vapor Deposition (MOCVD). Angle Resolved Auger electron spectroscopy (ARAES) indicates that Mg replaces Zn in ZnO lattice. Mg composition and films' crystal properties are characterized using transmission spectroscopy and x-ray diffraction (HRXRD), respectively. The in-plane strain along c-axis is compressive, while perpendicular to c-axis is tensile. Strain anisotropy reduces with increase in film thickness due to relaxation, with complete relaxation at film thickness of ~2µm. An increase in Mg composition increases a-axis lattice parameter and reduces c-axis lattice parameter, resulting in higher strain in the films. Scanning tunneling microscopy (STM) shows long and elongated terraces on films surface due to anisotropic surface diffusion and strain-relaxation. The direction of terraces is dependent on the miscut direction of r-sapphire substrates. The effects of film thickness, Mg composition, and deposition temperature on surface morphology have been analyzed. A red shift in the optical transmission edge is observed for electric field polarized perpendicular to in-plane c-axis as compared to that along in-plane c-axis. An increase in Mg composition reduces the separation in transmission edge. In-plane anisotropy in Hall mobility is analyzed, with mobility measured perpendicular to c-axis being higher than that along c-axis. The ZnO thin film transistors (TFTs) fabricated with devices aligned along and perpendicular to c-axis. The TFTs show high on-off ratio up to ~109. The field-effect mobility and transconductance of ~35.5cm2/Vs and 1.09mS/mm are obtained.Ph.D.Includes bibliographical references (p. 118-126)
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