VictorJuiz/thesis huggingface dataset:
Involvement of cyclic nucleotide-dependent protein kinases in the circadian responses to light in the suprachiasmatic nucleus

The behavior and metabolism of most organisms follow a 24-hour schedule. These rhythms persist in constant environmental conditions as circadian rhythms and can be synchronised by environmental cycles, primarily the daily cycle of light and dark. Pulses of light in constant dark are known to shift the phase of activity rhythms of nocturnal animals but only during the time of their cycle (circadian time; CT) when they are naturally active, i.e., the subjective night (SN). The onset of activity during each cycle is defined as CT 12. Light pulses induce phase delays of activity rhythms during early SN and induce advances during late SN. These rhythms are generated endogenously by the suprachiasmatic nuclei (SCN) of the hypothalamus. The light signal travels from the retina to the SCN mainly via the retinohypothalamic tract (RHT) where the signal is thought to be mediated by the neurotransmitter glutamate to SCN cells. (Abstract shortened by UMI.)
Accelerated cytotoxic mechanism screening of isoniazid and phenylhydrazine using an in vitro hepatocyte inflammation model

The use of hydrazine-derivatives as therapeutic agents is still quite prevalent despite the many documented toxic effects. In the present study we have screened various hydrazines, with a particular focus on isoniazid and phenylhydrazine, in an attempt to elucidate their molecular mechanism of toxicity. As hepatoxicity in vivo induced by many hepatotoxins has previously been attributed to resident or infiltrating inflammatory tells that form H2O2 when activated, the effect of H 2O2 on the hepatocyte cytotoxicity in WM of various hydrazines was investigated for the first time. It was found that H2O 2 markedly increased the cytotoxicity of these hydrazines, and derivatives of, by 10-100-fold. The cytotoxic mechanism for isomazid involved reactive oxygen species (ROS) formation and lipid peroxidation (LPO). The cytotoxic mechanism for phenylhydrazine involved ROS formation, LPO, GSH oxidation and collapse of the mitochondrial membrane potential, which occurred before the onset of cytotoxicity.
Acute opioid effects on cortisol and cytokines in bipolar disorder

Although hypothalamic-pituitary-adrenal axis and immune system dysregulation is prevalent in major depression it has not been well studied in bipolar disorder. Since opioids can modulate cortisol and cytokine secretions, this study examined whether opioid system dysfunction was associated with endocrine and immune system abnormalities. In a placebo-controlled cross-over study 8 bipolar depressed, 11 bipolar euthymic and 11 control subjects received 6mg oral hydromorphone. Results showed that basal cortisol, IL-6, IL-10 and IL-12 levels did not significantly differ among subject groups. Bipolar depressed subjects had significantly higher basal IL-8 levels than control and euthymic subjects. Morning IL-6 was significantly elevated in the depressed group compared to the euthymic group. Hydromorphone did not significantly influence cortisol or pro-inflammatory cytokine levels in any subject group however it significantly increased mean IL-10 levels. This is one of the first studies to examine endocrine, immune and opioid dysregulation in a major mental illness.
The role of SHIP1 in erythropoietin-mediated signalling

Erythropoietin (EPO) is the major in vivo regulator of mammalian erythropoiesis by promoting the survival, proliferation and differentiation of erythroid progenitors. It is well established that EPO activates the tyrosine phosphorylation of Shc resulting in recruitment of the Grb2/SOS complex and subsequent activation of the Ras/ERK signal transduction pathway. However, the molecular mechanism by which the Erythropoietin receptor (EPO-R) recruits Shc remained unknown. In this study, we showed that SHIP1 may couple EPO to the Ras/ERK signalling cascade by recruitment of the Shc/Grb2/SOS complex. We further demonstrated that SHIM is rapidly tyrosine phosphorylated in response to EPO stimulation and associates directly with the activated EPO-R in an SH2 domain-dependent manner through multiple phosphotyrosine residues that are located in an inhibitory domain. Concurrent with this analysis, Crk and DOK adaptor proteins were identified as SHIP1-interacting molecules. Crk proteins were observed to associate directly with SHIP1 and the EPO-R in an activation-dependent manner. Our results suggest that EPO may regulate Crk-dependent cellular processes through the binding of Crk proteins to SHIP1 and the EPO-R. Interleukin-3 (IL-3)-induced SHIP1/DOK2 complex formation was shown to result in activation of hematopoietic cell migration pathways. This effect was dependent on DOK2 Tyr351, which represents a putative Nck SH2 domain consensus-binding site. Detailed analyses were then performed to investigate the role of SHIP1 in erythroid development. SHIP1 ablation in adult mice was observed to lead to a 2.4-fold increase in total body BFU-E and a redistribution of BFU-E and CFU-E from the bone marrow to the spleen. SHIP1-deficient mice were found to recover their hematocrit more quickly from acute erythroid stimulation (phenylhydrazine-induced anemia) than wild-type controls. Furthermore, EPO-dependent phosphorylation of JAK2, EPO-R, STAT5, ERK1/2 and PKB was unaffected by the loss of SHIP1. These findings suggest that SHIP1 may be required for negative regulation of the proliferation and mobilization of primitive erythroid progenitors. Further study of SHIP1-regulated signalling pathways will continue to be useful in elucidating the role of SHIP1 within the erythroid lineage, and will ultimately further our understanding of erythroid development in steady-state, as well as in pathological situations associated with aberrant increases in cellular activation.
Conductivity and hall effect in diamond-like carbon (DLC) thin films

A set of four nitrogen doped films were successfully grown using the DC saddle field deposition system. Samples grown under these conditions were classified as hard a-C:H with a Tauc gap of about 1eV and resistivity of 1.43 GΩ·cm at 25°C. Upon addition of nitrogen the growth rate decreased and films exhibited an increase in conductivity in conjunction with a slight increment in Tauc gap and optical bandgap. A shift in the Fermi level towards the conduction band was also observed. Hall measurements were performed only on the sample deposited using a 30% gas fraction of nitrogen. Hall mobility was about 35 cm2/V −1·s−1. Hall coefficient showed a negative sign and an exponential behaviour suggesting electrons as the majority carrier in the conduction process. Decrease in the activation energy and in the film's disorder accompanied by an increment in conductivity, optical bandgap and mobility suggest that nitrogen is acting as a substitutional dopant.
Communicating mathematics online: the case of online help

This qualitative and quantitative study intended to define and explore the characteristics of asynchronous online mathematics help environments and look for some evidence that they provide conditions for learning. Data for the study were collected from online contributions on three purposely selected, public mathematics help sites; written reflections of expert tutors; and interviews with them. Peer tutors are found to be mathematics problem-driven and focused in their answers, as opposed to expert tutors who are following general rules of efficiency and honesty, and who are verbose in their answers. Both students and peer tutors are gracious in their acknowledgements, while experts are more direct in theirs. Expert tutors try to adapt their tutoring strategy to a student by holistically approaching the student's question. When a question lacks enough background information to help them to model a student, experts sometimes provide multiple answers. Expert tutors also use probes to gauge and provoke student's comprehension. They prefer to teach general rules and language of mathematics, and provide hints rather than complete work. This study found evidence of learning on mathematics online help sites and potential benefits for participants in discursive activities related to mathematics. The study showed that users of this service have specific goals, that peer tutors and expert tutors teach differently, and that online expert tutors use tutoring strategies that are specific to this medium. The students use mathematics online help primarily to request information. The questions on mathematics help sites are mostly homework related with isolated recorded cases of abuse of online help. In a small percentage of questions students provide feedback to tutors or participate in long discussions. Conversely, students ask a substantial number of deep-reasoning questions. This study also found evidence of achieved comprehension in students' messages and satisfaction with the help received on the Web sites. The study looked into the tutorial discourse with the intent to characterize communicative goals, form, cognitive level, hedging and degree of specification of students' questions in mathematics online help; and to distinguish what and how tutors in mathematics online help teach, do they hedge, and how helpful are their answers.

Keywords: Mathematics, Computer network resources
Mathematics, Study and teaching
Social perspective taking, empathy and social outcomes in children with Attention-Deficit/Hyperactivity Disorder

The overarching goal of this dissertation was to examine two aspects of social cognition (Empathy and Social Perspective Taking, SPT) in 8 to 12 year old children with Attention-Deficit/Hyperactivity Disorder (ADHD), and to investigate the relationship between SPT and social outcomes. The dissertation is comprised of two studies using the same sample of 92 children (50 ADHD and 42 typically developing). Study 1 examined empathy and SPT in children with and without ADHD and the predictors of these social cognitive skills. Although parents of children with ADHD rated their children as less empathic than children without ADHD, this difference was associated with co-occurring oppositional and conduct problems. Children with ADHD employed lower levels of SPT, and these differences persisted even after the role of language and oppositional/conduct problems were taken into account. Girls were more empathic and had higher overall SPT skills than boys. Study 2 explored the friendship characteristics and the relationship between SPT and social outcomes in children with ADHD. Although children with ADHD did not differ from comparison children in the number of friends they nominated, fewer of their nominated friends were corroborated by parents or teachers, their friendships were shorter in duration, they spent less time with friends outside of school, and had more friends with learning or behavioral problems than comparison children. SPT and ADHD symptoms shared variance in predicting social skills, but ADHD symptoms also explained unique variance. SPT moderated the relationship between ADHD symptoms and the length of friendship and the amount of telephone contact between friends. Results suggest that children with ADHD are not impaired in empathy, but their SPT is not as developed as those of comparison children. In general, ADHD symptoms were inversely related to social outcomes (i.e. social skills and some aspects of friendship) and SPT was positively related to social skills and friendship stability. While our results indicate that few children with ADHD are friendless, a number of aspects of their friendship characteristics place them at risk for poor adjustment. Clinical implications and directions for future research are discussed. (PsycINFO Database Record (c) 2016 APA, all rights reserved)
Numerical simulation of inlet and combustor regions of a real shcramjet flowfield

The numerical simulation of the three-dimensional flowfield of a shcramjet was performed using the WARP code, in which multispecies Favre-averaged Navier-Stokes equations are closed by the k-o turbulence model and the Wilcox dilational dissipation correction. The hydrogen/air chemical reactions are modeled by Jachimowsky's 9 species, 20 reaction model. This thesis addresses the problem of designing a shock-induced combustion ramjet (shcramjet) engine. Previous studies have investigated cantilevered ramp injectors using a two oblique shock external compression inlet with a hydrogen slot injector to suppress ignition. The present study uses a cowl to generate flow-turning angles of 12° and 16°. The reflected shocks induce combustion after ignition delays of 10.5 cm and 4.5 cm, respectively. It was found that maximum thrust potentials for each case were 203.4 and 218.8 Ns/kg, indicating that an increase in shock strength reduces the ignition delay without contributing to any significant increase in thrust potential.

Keywords: Airplanes, Scramjet engines
Embedded wavelet-based coding of the shape and texture of arbitrarily-shaped visual objects

This thesis addresses the issue of coding the shape and texture of arbitrarily-shaped visual objects. Arbitrarily-shaped visual objects are images which are not necessarily rectangular in shape and are described by two basic features: shape and texture. Current state-of-the-art object-based coding schemes do not provide integrated coding of both the shape and the texture. They require that the shape of the object be pre-transmitted before the texture can be decoded. An embedded wavelet-based scheme which codes both the shape and texture of an arbitrarily-shaped object in one integrated algorithm is proposed. Called shape and texture SPIHT (ST-SPIHT), the proposed scheme is based on the shape-adaptive discrete wavelet transform (SA-DWT) with lifting implementation and the set partitioning in hierarchical trees (SPIHT) wavelet-based coding scheme. Subjective and objective results showed that the ST-SPIHT scheme performed better than other state-of-the-art schemes, such as JPEG2000, under certain conditions and requirements.
Huron potters and archaeological constructs: researching ceramic mirco-stylistics

This thesis examines the commonplace framework of assumptions that have been in use in Huron ceramic analysis. Customary views on Huron pots, potters and potting systems are revisited here in light of extant ethnographic and ethnohistorical literature pertaining to traditional pottery manufacture, use and discard and, at an analytical level, through the testing of selected ceramic samples from three contact period Huron sites—Ball (BdGv-3), Auger (BdGw-3), and Thomson-Walker (BeGv-3). Using a multi-component, multi-scalar research design, this work singles out three important problems in Huron ceramic analysis - vessel function, population relocations and ethnicity, the organization of ceramic production—and explores the implications of data analysis and corroborating evidence for our understanding of each. Previously, none of these issues have received extensive treatment since it has been thought that: (1) Huron pottery was simply made and did not incorporate functional categories; (2) production was simply organized, carried out in the household and therefore geared toward self-sufficiency, and; (3) women decorated their pots only according to personal or family tradition and choice. A multivariate approach to artifact analysis was used to help identify multiple layers and meanings of “stylistic” attributes on Huron pots. It assisted in the identification of potential functional categories of vessels, including strong correlations between decorative attributes and vessel size classes, which suggests future function-oriented research is needed. When combined with the concept of micro-style (i.e., patterned behaviours in individual, family and community manufacturing practices and traditions), this approach revealed intra-village exchanges and the relocation of potters between successive villages. In the future, a micro-stylistic approach will prove more meaningful for reconstructing tribal or ethnic territories and affiliations. The skill and standardization levels observed on Huron vessels from the Ball and Auger sites were quite high, and alongside the widespread intra-village distribution of products of single potters, hints at a higher level of productive organization than normally presumed. Therefore, this work recognizes the need for a better informed understanding of the nature of craft production in Huron communities and its role in local and regional economies.

Keywords: Iroquoian Indians, Pottery
Indians of North America, Pottery
Indians of North America, Ontario
Du mot injuste au mot juste: count(er)ing costs of black holocausts, a panAfrikan approach to education

By accident or intent, commission or omission, 'the word', in recounting panAfrikan histories and the holocausts they reveal, generally masks 'the crime'. This thesis examines hidden costs of Black holocausts on panAfrikan life chances over thirty generations. It analyses texts where 'Others', overwhelmingly, have recorded and told our stories, prescribing the words with which we clothe our collective memory. This study also explores continuities within Afrikan speech and cultural expression in Europe, the Caribbean and the Americas. It reveals aspects of Afrikan culture, lost because of Black holocausts, in ancestral languages like Wolof and Twi and data from museum studies, artefacts, the arts and popular culture. Through careful reflection on panAfrikanist perspectives, this thesis (1) enhances new ways of understanding, of telling, measuring and eventually countering the costs of externally manufactured panAfrikan holocausts and (2) explores the possibilities and significance of education which draws on these panAfrikanist ways of seeing.

Keywords: Pan-Africanism, History
Wolof language
Antislavery movements, History
Discourse analysis
Communication
Slavery, History
English language, Slang
Racism in language
Race relations in literature
Blacks, Race identity
Twi language
Blacks, Race identity
Blacks, Africa
African diaspora, Social aspects
Meaning-making through art-making at a community-based art program

This study explores how children make-meaning through art-making at a community art program in an inner city community in Toronto. Through five months of fieldwork research at A Home for Creative Opportunity, interviews with four of the staff and a literature review, a deepened understanding of the children's experiences in the art program was gained. In this inquiry the contextual forces of the Regent Park community are considered alongside the activities that take place on a daily basis at the Art Centre. Questions that fuelled the inquiry are: how does meaning-making evolve from art-making in a community-based arts program, for the children who participate? And how does engagement in art-making affect these children, particularly in light of the challenging circumstance of growing up in Regent Park? The researcher identifies tangible themes and forces informing the children's experiences in the program, and considers the importance of community-based art initiatives as a mechanism of both personal and communal transformation.

Keywords: City children, Services for
Art, Study and teaching
Creative ability in children
Art, Psychological aspects
Art therapy for children
Parents' and teachers' reports of executive function deficits at different chronological ages for children diagnosed with ADHD

Some theories of Attention-Deficit/Hyperactivity Disorder (ADHD) have suggested that a deficit in Executive Function (EF) may underlie this disorder. The present study used a new behavioural rating scale to explore executive functioning in children with ADHD in two different settings and at different stages of development. The Behaviour Rating Inventory of Executive Function samples children's everyday executive skills in their natural settings through parent and teacher reports. This study examined archival clinical data of 240 children between the ages of 5 and 15. A comparison of parent and teacher ratings revealed that teachers reported a greater range of EF impairment and greater severity of deficits. Teachers also indicated more change across the five age groups. The profile of executive dysfunction differed among the age groups, with the 7- to 8-year-olds exhibiting the least amount of impairment. Significant differences between genders and ADHD subtypes were found on some scales.

Keywords: Attention-deficit hyperactivity disorder
Developmental psychology
Child psychology
The hemodynamic effects of negative inspiratory pressure during orthostatic stress

It has been argued that negative inspiratory pressure (NIP) may improve orthostatic tolerance. In order to evaluate the hemodynamic effects of NIP during orthostasis, ten healthy males and six males with spinal cord injury (SCI) below T6 underwent tilting with Sham (0 cm H2O) and NIP ( -9 cm H2O). Changes in blood pressure (BP), heart rate (HR), cardiac output (Q dot;), SV and total peripheral resistance (TPR) were compared between conditions. Autonomic modulation of HR was assessed through HR variability analysis. In healthy subjects, tilting with NIP and Sham produced similar falls in Q dot; and SV and rise in TPR, however NIP may have buffered the early hemodynamic changes. Average BP and HR increased equally between conditions. Sympathetic activity appeared higher with NIP. Pathophysiological differences in SCI subjects may have confounded measurement of Q dot;, SV and TPR. Further studies evaluating the hemodynamic effects and therapeutic potential of NIP are needed.
Collaborative filtering: A machine learning perspective

Collaborative filtering was initially proposed as a framework for filtering information based on the preferences of users, and has since been refined in many different ways. This thesis is a comprehensive study of rating-based, pure, non-sequential collaborative filtering. We analyze existing methods for the task of rating prediction from a machine learning perspective. We show that many existing methods proposed for this task are simple applications or modifications of one or more standard machine learning methods for classification, regression, clustering, dimensionality reduction, and density estimation. We introduce new prediction methods in all of these classes. We introduce a new experimental procedure for testing stronger forms of generalization than has been used previously. We implement a total of nine prediction methods, and conduct large scale prediction accuracy experiments. We show interesting new results on the relative performance of these methods.
Identification of known and novel fluorinated compounds in AFFF via fluorine-19-NMR, LC-MS/MS, and LC-Quad-TOFMS, and the aerobic biodegradation of 6:2 FtS

Aqueous film-forming foam (AFFF) is a fluorinated surfactant mixture used to extinguish hydrocarbon fuelled fires, and can be correlated to the detection of perfluorocarboxylic acids (PFCAs) in the environment. This thesis investigated AFFF as a point source for PFCAs by analyzing known and novel fluorinated compounds in AFFF via 19F-NMR, LC-MS/MS, and LC-Quad-TOFMS, and metabolites in the aerobic biodegradation pathway of 6:2 fluorotelomer sulfonate (FtS). Eleven of thirteen AFFF samples contained significant amounts of fluorine and similarities in composition, but only small amounts of known fluorinated compounds and no 6:2 FtS. Two newly recognized potential FtS and PFCA precursors were identified by LC-Quad-TOFMS in six AFFF samples, and molecular formulas were predicted for other potentially fluorinated ions. Dominant metabolites observed in the biodegradation of 6:2 FtS included 6:2 fluorotelomer alcohol (FTOH) and 6:2 fluorotelomer carboxylic acid (FTCA); 6:2 fluorotelomer unsaturated carboxylic acid (FTUCA) and perfluorohexanoic acid (PFHxA) were also detected.