410 research outputs found
Exercise related anxiety-like behaviours are mediated by TNF receptor signaling, but not depression-like behaviours
No full textAvailable online 22 May 2018Abstract not availableJulie A. Morgan, Gaurav Singhal, Frances Corrigan, Emily J. Jaehne, Magdalene C. Jawahar, Bernhard T. Baun
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
Cytokine levels in major depression are related to childhood trauma but not to recent stressors
No full textAbstract not availableLaura Grosse, Oliver Ambrée, Silke Jörgens, M. Catharine Jawahar, Gaurav Singhal, David Stacey, Volker Arolt, Bernhard T. Baun
Advancing porous heat transfer materials and polymer coatings with photonic structures
No full textSubmission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2025-12-01The student, Gaurav Singhal, accepted the attached license on 2023-11-27 at 13:11.The student, Gaurav Singhal, submitted this Dissertation for approval on 2023-11-27 at 13:19.This Dissertation was approved for publication on 2023-11-30 at 16:12.DSpace SAF Submission Ingestion Package generated from Vireo submission #20022 on 2024-03-01 at 13:50:27Multi-dimensional photonic structures have been extensively explored for various applications, including waveguides, filters, and lenses. Metallic counterparts of such structures have been explored for their application in heat transfer and sensing. However, there has been a noticeable gap in research regarding the optical-based fabrication and optical applications of two- and three-dimensional metallic structures in the realms of heat transfer and polymer science. This can be attributed to reliance on methods that are less scalable and difficulty of using optical methods on substrates that can cause additional problems like reflection. This research addresses this gap by utilizing two- and three-dimensional metallic structures to solve critical challenges in these fields. This thesis critically evaluates a particular class of multi-dimensional photonic structures, specifically the templated electroplated metallic copper inverse opals (CIO) with densely packed pores. It comprehensively examines their electrical, thermal, and mechanical properties, as detailed in Chapter Two. While CIOs demonstrate an encouraging electrical conductivity of roughly 15% compared to pure copper, in line with structural expectations and measured electroplated copper conductivity, their thermal reliability is a cause for concern. Consequently, the study pivots to the application of interference lithography, leveraging a copper oxide anti-reflection coating (nCO) that can be electrochemically reduced to copper metal. This advancement facilitates the creation of three-dimensionally structured templates on reflective substrates, a concept discussed in Chapter Three. The resultant nCO structures display exceptional radiation absorbance, and their ability to be converted into copper metal during electrochemical deposition of metal, significantly enhances two-phase cooling applications. In addition, two-dimensional plasmonic structures are employed to address the critical need for a robust method offering high temporal and spatial resolution in characterizing molecular transport within polymers. This necessity holds immense importance across diverse sectors, including pharmaceuticals, textiles, and food and beverage packaging, as well as within the broader polymer science community. By leveraging the amplified infrared (IR) absorbance sensitivity of plasmonic nanoantenna-based surface-enhanced infrared absorption (SEIRA), a novel approach is introduced in Chapter Four. For the study of self-stratifying polyurethane coatings in Chapter Five, traditional methods are adopted due to the limitations of plasmonic structures for thicker coatings. This investigation yields valuable insights into the self-stratification process when hydrophobic and hydrophilic polyols and prepolymers are carefully mixed under controlled conditions, as verified through techniques such as SIMS, XPS, and confocal Raman spectroscopy. Ultimately, this research contributes to the advancement of efficient coating applications, benefiting a broad spectrum of surfaces. Collectively, these research efforts has made significant advances in the field of multi-dimensional photonics structures by successfully applying the two and three-dimensional metallic structures in the field of heat transfer and polymer science. We have successfully demonstrated application of structure copper oxide as anti-reflection coating for optical fabrication methods like interference lithography and proximity field nano-patterning. This work opens up a new avenue for fabricating structures with high surface area to volume ratio for higher critical heat flux (CHF) applications as we demonstrate with the help of two-phase cooling experiments where we see three times improvement when compared with CHF of bare silicon substrate. This work also overcome the problems associated with the colloidal self-assembly method like template cracking and delamination which affects the scalability to industrial scales. Further, we demonstrate significant enhancement in infrared absorbance sensitivity through plasmonic nanoantenna-based surface-enhanced infrared absorption (SEIRA) within a 50 nm proximity of a thin film under investigation, enabling precise detection of trace analytes and diffusion measurements in thin polymer films. Compared to a standard attenuated total internal reflection (ATR) system, this method improves the limit of detection by at least 13-fold and reduces the detection volume by approximately 15-fold, facilitating the determination of diffusion coefficients and solubility’s of specific molecules in thin polymer films, including L-ascorbic acid, ethanol, sugars, and water in various mixtures. Acknowledging the limit of SEIRA technique for thin film studies, we used conventional characterization studies to analyze polyurethane self-stratifying coating system and prove that the interfacial energy can be used as driving force for stratification in such systems and achieve the desired result
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 relationship between mean platelet volume and coronary collateral vessels in patients with acute coronary syndromes
No full textBackground: Elevated mean platelet volume (MPV) has been proposed as a risk factor for coronary artery disease (CAD) and is associated with poor clinical outcome in acute coronary syndrome (ACS). However, some studies have contradictory findings. Hence, we aimed to evaluate the association of MPV with the presence of coronary collateral vessel (CCV) in patients with ACS. Objective: To find MPV value in ACS patients and to find the predictive value of MPV in the spectrum of CAD and to examine whether levels of MPV predict the presence of CCVs. Methods: A total of 180 patients with first ACS were included in the study. MPV was measured. All patients underwent coronary angiography to know disease severity and CCVs. The CCVs are graded according to the Rentrop scoring system and according to coronary angiography results; patients were divided into two groups as Group 1 (poor CCV) and Group 2 (good CCV). Results: The MPV was 10.74 ± 2 fl in poor collateral group patients and 11.01 ± 1.7 fl in good collateral group (P = 0.421). The presence of CCV was not significantly associated with high levels of MPV. MPV value did not show any prediction of the spectrum of CAD. Conclusion: MPV on admission was not associated with the development of CCV positively in patients with ACS. Furthermore, it is not associated with a number of vessel involvements
TNF signalling via the TNF receptors mediates the effects of exercise on cognition-like behaviours.
No full textAltered TNF levels are associated with cognitive impairment in depression, schizophrenia, bipolar disorder, and Alzheimer's disease (AD). Exercise improves cognition-like behaviours, reduces the expression of tumour necrosis factor alpha (TNF), and increases expression of the soluble TNF receptors soluble TNFR1 (sTNFR1) and sTNFR2. We suggest TNF and its receptors are involved in cognitive function and dysfunction, and investigate whether exercise mediates its effects on cognitive function via TNF and its receptors.We utilised C57BL/6, TNF-/-, TNFR1-/-, and TNFR2-/- mice to compare exercise to non-exercise control groups to investigate whether exercise exerts its effects on various types of cognition-like behaviours via TNF and its receptors.Recognition memory improved with exercise in WT mice, was impaired in TNFR1-/- exercise mice, showed non-significant impairment with exercise in TNF-/- mice, and no changes in TNFR2-/- mice. In spatial learning there were exercise related improvements in WT mice, non-significant but meaningful impairments evident in TNFR1-/- exercise mice, modest improvement in TNF-/- exercise mice, and potentially meaningful non-significant improvements in TNFR2-/- exercise mice. Moreover, WT and TNFR2-/- mice displayed noteworthy non-significant improvements in spatial memory, whereas TNFR1-/- exercise mice demonstrated non-significant spatial memory impairment. Exercise did not alter cognitive flexibility in any strain.TNF receptor signalling via the TNFR1 and TNFR2 appears to mediate the effects of exercise on cognitive-like behaviours. The potential for exercise to regulate human TNF and TNF signalling and cognitive dysfunction needs investigation under inflammatory conditions including depression and neuropsychiatric disorders.Julie A. Morgan, Gaurav Singhal, Frances Corrigan, Emily J. Jaehne, Magdalene C. Jawahar, Bernhard T. Baun
The effects of aerobic exercise on depression-like, anxiety-like, and cognition-like behaviours over the healthy adult lifespan of C57BL/6 mice
No full textPreclinical studies have demonstrated exercise improves various types of behaviours such as anxiety-like, depression-like, and cognition-like behaviours. However, these findings were largely conducted in studies utilising short-term exercise protocols, and the effects of lifetime exercise on these behaviours remain unknown. This study investigates the behavioural effects of lifetime exercise in normal healthy ageing C57BL/6 mice over the adult lifespan. 12 week-old C57BL/6 mice were randomly assigned to voluntary wheel running or non-exercise (control) groups. Exercise commenced at aged 3 months and behaviours were assessed in young adult (Y), early middle age (M), and old (O) mice (n=11-17/group). The open field and elevated zero maze examined anxiety-like behaviours, depression-like behaviours were quantified with the forced swim test, and the Y maze and Barnes maze investigated cognition-like behaviours. The effects of lifetime exercise were not simply an extension of the effects of chronic exercise on anxiety-like, depression-like, and cognition-like behaviours. Exercise tended to reduce overt anxiety-like behaviours with ageing, and improved recognition memory and spatial learning in M mice as was expected. However, exercise also increased anxiety behaviours including greater freezing behaviour that extended spatial learning latencies in Y female mice in particular, while reduced distances travelled contributed to longer spatial memory and cognitive flexibility latencies in Y and O mice. Lifetime exercise may increase neurogenesis-associated anxiety. This could be an evolutionary conserved adaptation that nevertheless has adverse impacts on cognition-like function, with particularly pronounced effects in Y female mice with intact sex hormones. These issues require careful investigation in future rodent studies.Julie A. Morgan, Gaurav Singhal, Frances Corrigan, Emily J. Jaehne, Magdalene C. Jawahar, Bernhard T. Baun
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