cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Limits on fast radio bursts at 145 MHz with ARTEMIS, a real-time software backend
Creators: name: Karastergiou, A.
name: Chennamangalam, J.
name: Armour, W.
name: Williams, C.
name: Mort, B.
name: Dulwich, F.
name: Salvini, S.
name: Magro, A.
name: Roberts, S.
name: Serylak, M.
name: Doo, A.
name: Bilous, A. V.
name: Breton, R. P.
name: Falcke, H.
name: Grießmeier, J. M.
name: Hessels, J. W.T.
name: Keane, Evan
name: Kondratiev, V. I.
name: Kramer, M.
name: Van Leeuwen, J.
name: Noutsos, A.
name: Oslowski, Stefan
name: Sobey, C.
name: Stappers, B. W.
name: Weltevrede, P.
Publisher: name: Swinburne
Year: 2024

description: Fast Radio Bursts (FRBs), are millisecond radio signals that exhibit dispersion larger than what the Galactic electron density can account for. We have conducted a 1446 hour survey for Fast Radio Bursts (FRBs) at 145~MHz, covering a total of 4193 sq. deg on the sky. We used the UK station of the LOFAR radio telescope -- the Rawlings Array -- , accompanied for a majority of the time by the LOFAR station at Nanc{c}ay, observing the same fields at the same frequency. Our real-time search backend, ARTEMIS, utilizes graphics processing units to search for pulses with dispersion measures up to 320 cm−3 pc. Previous derived FRB rates from surveys around 1.4~GHz, and favoured FRB interpretations, motivated this survey, despite all previous detections occurring at higher dispersion measures. We detected no new FRBs above a signal-to-noise threshold of 10, leading to the most stringent upper limit yet on the FRB event rate at these frequencies: 29 sky−1 day−1 for 5~ms-duration pulses above 62~Jy. The non-detection could be due to scatter-broadening, limitations on the volume and time searched, or the shape of FRB flux density spectra. Assuming the latter and that FRBs are standard candles, the non-detection is compatible with the published FRB sky rate, if their spectra follow a power law with frequency (∝να), with α≳+0.1, demonstrating a marked difference from pulsar spectra. Our results suggest that surveys at higher frequencies, including the low frequency component of the Square Kilometre Array, will have better chances to detect, estimate rates and understand the origin and properties of FRBs.
Probing for the Rashba Effect in Novel Two-Dimensional Hybrid Perovskites with Terahertz Emission Spectroscopy
Creators: name: Wu, Nova
Publisher: name: Stanford Digital Repository
Year: 2026
Subjects: Rashba Effect
Terahertz Emission Spectroscopy
Hybrid Perovskite
Helicity dependence

description: Ferroelectricity is a property where materials contain spontaneous, polarization states that can be aligned in the same direction by a built-in electric field. When combined with photovoltaic devices this ferroelectric response can improve charge carrier separation and increase photovoltaic efficiency.  When spin-orbit coupling effects, such as the Rashba effect, are also present in a material, an additional level of control over optoelectronic properties is offered in comparison to an ordinary ferroelectric system. These materials, known as Ferroelectric Rashba semiconductors (FERSCs), include noncentrosymmetric two-dimensional hybrid perovskites (2DHPs), which are promising candidates for applications in retinomorphic technologies and spintronic devices. In this work, we probe for the Rashba effect in noncentrosymmetric 2DHPs with the formula (2-FBZ)₂(A)ₙ₋₁PbₙI₃ₙ₊₁ (2-FBZ = 2-fluorobenzylammonium, A designates organic cations including FA = formamidinium and MA = methylammonium) by probing for a helicity-dependent response. Our results indicate no change in response in all three 2DHPs as there is little difference in THz signals from exposure to right vs left circularly polarized light. A lack of helicity-dependence also indicates absence of the Rashba effect, meaning emitted THz fields may originate from out of plane currents generated by trivial effects including Dember fields, band bending, and optical rectification. Further work entails degradation studies of the 2DHPs under varying fluence, measurements with a half wave plate to probe for the presence of optical rectification, and measurements with vertical wire-grid polarizer orientation for maximized detection of in-plane induced current responses.
Contributions of striatal circuits to interval timing
Creators: name: Bruce, Robert Austin
Publisher: name: University of Iowa
Year: 2025
Subjects: subject: Dopamine Receptors
subject: Striatum
subject: Timing
subject: public abstract
subject: Physiology
subject: FOS: Biological sciences

description: Time represents a fundamental dimension around which all adaptive behavior must inherently be organized. The ability to prospectively organize actions in time depends upon striatal circuits and is disrupted in disease states involving basal ganglia dysfunction. However, how striatal neurons encode and facilitate prospective timing remains poorly understood.
description: To further shed light on this issue, I recorded and manipulated striatal ensembles as I trained mice on a novel interval timing task. I report four primary results. Firstly, time-related ‘ramping’ activity, monotonic increases or decreases in firing rate with the passage of time, becomes more prominent amongst striatal medium spiny neurons (MSNs) as mice gain experience performing timed action. Second, I found that this pattern of activity is sensitive to pharmacological blockade of the D2 dopamine receptors, but not D1 dopamine receptors. Third, I found that directly perturbing either D1- or D2-MSNs via cell-type specific optogenetics was sufficient to disrupt timed behavior. Finally, I found that time-related ‘ramping’ activity was initially attenuated following striatal dopamine depletion, and treatment with the dopamine precursor levodopa further compounded these deficits.
description: My results suggest that interval timing is dependent upon balanced activity across both direct and indirect projecting striatal neurons. My hope is that these findings will contribute to a better understanding of how striatal circuits facilitate fundamental cognitive processing which might then be harnessed to address cognitive dysfunction, particularly in patients suffering from Parkinson’s disease and other diseases of the basal ganglia.
title: Money and relationships
title: differences in risk preferences in the social and financial domains
titleType: Subtitle
Creators: name: Lee, Sunme
Publisher: name: University of Iowa
Year: 2024
Subjects: Judgment and Decision Making
Risk
Social
public abstract

description: For decades, the central tenet of prospect theory has been the idea of loss aversion: the notion that people find losses so unpleasant they will take greater risks to avoid loss than to pursue gains. Although much of the evidence about loss aversion comes from studies conducted in the financial domain, there is much to learn about how people react to risk in other domains, particularly in a social context. How do people respond to risk in social decisions? The current work explores how people make decisions related to social relationships. This paper extends the understanding of prospect theory to the social domain by testing different risk preference mechanisms.
title: “We're on the front line”
title: a mixed methods study on sex educators' work navigating controversy as street level bureaucrats
titleType: Subtitle
Creators: name: Bartlett-Chase, Meghanne
Publisher: name: University of Iowa
Year: 2022
Subjects: Health Teachers
Sex Education Teachers
Sex Educators
Sexual Health
Sexual Policy
public abstract
Public Policy
Sex Education

description: Comprehensive sex education (CSE) holds vital opportunity for students to learn how to make informed decisions for their sexual and relational health, but CSE policies also tend to attract heated debates and controversy. Even when CSE standards are instated, these policies are only as effective as their implementation, and policymakers rarely discuss teachers as the primary implementors of sex education legislation. This study aimed to better understand teachers’ experiences implementing sex education policies in communities where the policy may be seen as controversial. To do so, I used the street level bureaucracy theoretical framework to conduct a mixed methods study on the Washington Healthy Youth Act, a CSE policy that was voted on and approved by state voters. The analyses included county-level statistical analysis of voters and community characteristics as well as interviews with Washington public school sex education teachers. This study found that the higher proportion of conservative voters in a county, the more likely it was that county opposed the school-based comprehensive sex education policy. This suggests a highly politicized nature of sex education that created challenges for the public school sex education teachers in this study. I referred to those challenges as “perceived policy controversiality” and posit it as an addition to the street level bureaucracy framework. Despite the divisiveness of the CSE policy at the voter level, teachers largely managed their classrooms and school communities with relatively low backlash. Ultimately, this study finds hope that teachers can successfully implement CSE policy even in controversial spaces.
Skein theory and its applications to tensor categories
Creators: name: Poudel, Anup
Publisher: name: University of Iowa
Year: 2022
Subjects: Quantum invariants
Skein theory
Spiders
Tensor categories
public abstract

description: This thesis is composed of two main parts. The first part focuses on families of unitary fusion categories $\C$ that contain at least one selfdual object, $q$, satisfying a fusion rule of the form $q\otimes q \cong \bm{1}\oplus\bigoplus^k_{i=1}x_{i}$. Assuming the category is ribbon, we classify all associated ribbon structures when $k=1,2$. In particular, we also consider the cases when $q$ is antisymmetrically selfdual. Further, a comprehensive discussion on construction of a ``canonical diagrammatic basis'' for any unitary fusion category is provided.\\
description: In the second part, we focus on spider categories associated to the representation category of the quantum group $U_q(SL_n)$. We work with the full subcategory of the spider category, $\mathcal{S}p(SL_n)$ from \cite{ckm}, whose objects are monoidally generated by the standard representation and its dual, and show that this category is equivalent as a spherical braided (ribbon) category to the spider category which is a quotient category coming from Sikora's relations in \cite{sik}. This answers a question from Morrison's Ph.D. thesis \cite{mor}.We also show that the full subcategory (with standard representation and its dual as objects) of MOY's quotient category defined using their relations in \cite{moy} is equivalent as a spherical braided category to the HOMFLYPT category, which is a quotient category with standard representation and its dual as objects with relations coming from the HOMFLYPT relations.
Telephony and the NBN
Creators: name: Darling, Peter
Publisher: name: Swinburne
Year: 2024

description: Most of the discussion about Australia's National Broadband Network (NBN) has been about the costs, the benefits and the implementation of "super-fast broadband". This article looks at another important use that will be made of the optical fibre to the user provided by the NBN - the provision of telephony service as a continuation of the current standard telephone service available across Australia. The article looks at the extensive range of current policies that will have to be considered and quite possibly modified with the implementation of the NBN. Work has begun on only a few, but many more policy areas will have to be resolved to enable a smooth transition to the new network and identify the ubiquitous services that the NBN will provide.
Protein Interactome of Muscle Invasive Bladder Cancer
Creators: name: Bhat, Akshay
name: Heinzel, Andreas
name: Mayer, Bernd
name: Perco, Paul
name: Mühlberger, Irmgard
name: Husi, Holger
name: Merseburger, Axel S.
name: Zoidakis, Jerome
name: Vlahou, Antonia
name: Schanstra, Joost
name: Mischak, Harald
name: Jankowski, Vera
Publisher: name: Charité - Universitätsmedizin Berlin
Year: 2015
Subjects: subject: 600 Technik, Medizin, angewandte Wissenschaften::610 Medizin und Gesundheit

description: Muscle invasive bladder carcinoma is a complex, multifactorial disease caused by disruptions and alterations of several molecular pathways that result in heterogeneous phenotypes and variable disease outcome. Combining this disparate knowledge may offer insights for deciphering relevant molecular processes regarding targeted therapeutic approaches guided by molecular signatures allowing improved phenotype profiling. The aim of the study is to characterize muscle invasive bladder carcinoma on a molecular level by incorporating scientific literature screening and signatures from omics profiling. Public domain omics signatures together with molecular features associated with muscle invasive bladder cancer were derived from literature mining to provide 286 unique protein-coding genes. These were integrated in a protein-interaction network to obtain a molecular functional map of the phenotype. This feature map educated on three novel disease-associated pathways with plausible involvement in bladder cancer, namely Regulation of actin cytoskeleton, Neurotrophin signalling pathway and Endocytosis. Systematic integration approaches allow to study the molecular context of individual features reported as associated with a clinical phenotype and could potentially help to improve the molecular mechanistic description of the disorder.
Effects of viscosity on dynamic interfacial tension.
Creators: name: Touhami, Youssef.
Publisher: name: Université d'Ottawa / University of Ottawa
Year: 1990
Subjects: subject: Engineering, Chemical.

description: In this study, we have investigated the interfacial tension (IFT)-lowering potential of a range of caustic solutions which were contacted with dilute solution of linoleic acid in light paraffin oil. Two polymers, namely, polyvinyl alcohol and polyacrylamide were added to the caustic solution in order to increase bulk phase viscosity. The dynamic IFT of caustic, polymer and caustic-polymer solutions were measured. By using different linoleic acid concentrations up to 100 mM, it was found that an increase in acid concentration was accompanied by a decrease in IFT for any given caustic composition. When the acid strength was fixed at 10 mM and the caustic concentration was also increased up maximum of 250 mM, the lowest IFT values were obtained at 12.5 mM NaOH. The dilute polymer solutions lowered the IFT of the oleic phase against neutral water from 30.0 to about 15 mN/m. However, the addition of the polymeric material to the caustic solution produced a marginal reduction in dynamic IFT at early contact times and also produced characteristic IFT minima at all caustic concentrations. (Abstract shortened by UMI.)
Is ultrasound suited to probe electrochemical processes in batteries? An operando multiprobe investigation of NMC/graphite commercial cell
Creators: name: Villevieille, Claire
name: Renais, Corentin
name: Mercier-Guyon, Benjamin
name: Wasylowski, David
name: Sonnet, Morian
name: Dechent, Philipp André
name: Servajon, Maxime
name: Blanc, Nils
name: Lyonnard, Sandrine
name: Sauer, Dirk Uwe
Publisher: name: RWTH Aachen University
Year: 2024

description: 12 Seiten (2024). doi:10.21203/rs.3.rs-5111062/v1
Association of body mass index with knee cartilage damage in an asymptomatic population-based study
Creators: name: Keng, Alvin
name: Sayre, E. C.
name: Guermazi, Ali
name: Nicolaou, Savvakis
name: Esdaile, John
name: Thorne, Anona
name: Singer, Joel
name: Kopeć, Jacek A.
name: Cibere, Jolanda, 1962-
Publisher: name: BioMed Central
Year: 2017

description: Background: Cartilage changes are an important early finding of osteoarthritis (OA), which can exist even before symptoms. Our objective was to determine the prevalence of knee cartilage damage on magnetic resonance imaging (MRI) in an asymptomatic population-based cross-sectional study and to evaluate the association of body mass index (BMI) with cartilage damage. Methods: Subjects, aged 40-79 years, without knee pain (n = 73) were recruited as a random population sample and assessed for BMI (kg/m2), including current BMI (measured), past BMI at age 25 (self-reported) and change in BMI. Knee cartilage was scored semi-quantitatively (grades 0-4) on MRI. In primary analysis, cartilage damage was defined as ≥2 (at least moderate) and in a secondary analysis as ≥3 (severe). We also conducted a sensitivity analysis by dichotomizing current BMI as <25 vs. ≥25. Logistic regression was used to evaluate the association of each BMI variable with prevalent MRI-detected cartilage damage, adjusted for age and sex. Results: Of 73 subjects, knee cartilage damage ≥2 and ≥3 was present in 65.4% and 28.7%, respectively. The median current BMI was 26.1, median past BMI 21.6, and median change in BMI was a gain of 2.8. For cartilage damage ≥2, current BMI had a non-statistically significant OR of 1.65 per 5 units (95% CI 0.93-2.92). For cartilage damage ≥3, current BMI showed a trend towards statistical significance with an OR of 1.70 per 5 units (95% CI 0.99-2.92). Past BMI and change in BMI were not significantly associated with cartilage damage. Current BMI ≥ 25 was statistically significantly associated with cartilage damage ≥2 (OR 3.04 (95% CI 1.10-8.42)), but not for ≥3 (OR 2.63 (95% CI 0.86-8.03)). Conclusions: MRI-detected knee cartilage damage was highly prevalent in this asymptomatic population-based cohort. We report a trend towards significance of BMI with cartilage damage severity. Subjects with abnormal current BMI (≥25) had a 3-fold increased odds of cartilage damage ≥2, compared to those with normal BMI. This study lends support towards the role of obesity in the pathogenesis of knee cartilage damage at an asymptomatic stage of disease.
Experimental and analytical investigation on the behavior of continuous box girder bridges.
Creators: name: Wakim, Maroun Ghosn.
Publisher: name: Université d'Ottawa / University of Ottawa
Year: 1996
Subjects: subject: Engineering, Civil.

description: Continuous curved box girder bridges are increasingly being used in metropolitan large cities particularly as flyovers and as entrance and exit ramps for highspeed freeways. The purpose of this investigation is to examine the static response of continuous curved box girder bridges subjected to various specified OHBD loadings. The prototype structure that was selected for this model study is the Cyrville road Queensway overpass located in the east end of Ottawa. The structure was built in 1973 and designed according to ASHTO design truck load HS20-44 by the Ministry of Transportation and Communication. The bridge is 102.4 meters long, 12.8 meters wide, and consists of two spans with 16.8$\sp\circ$ horizontal angle of curvature between the end supports. Its cross section consists of four contiguous cells with a depth of 1.83 meters. As for the diaphragms, two prestressed diaghragms are placed at the extreme end supports and one is placed over the middle support.
Two-dimensional gas chromatography time-of-flight mass spectrometry (gcxgc-tof-ms) data analysis for identifying unknown persistent organic pollutants in milk samples
Creators: name: Flores, Allison
Publisher: name: University of Iowa
Year: 2022
Subjects: Chemometric Analysis
Principal Component Analysis
Relative Retention Times
public abstract
Signal Processing

description: Persistent organic pollutants (POPs) i.e., polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs), are targeted in chemometric analysis. Comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometer (GCxGC-ToF-MS) data is collected to identify the POPs that are toxic and have adverse effects to human health. The Food and Drug Administration (FDA) has collected data relevant to this research over the past ten years. While thousands of compounds are extracted in the analytical hardware, only twenty-three compounds, well-known to the chemists are targeted in these samples. This leaves a knowledge gap regarding the role and prominence of the other compounds, i.e, non-target analytes, in each sample. The purpose of this research is to analyze the instrumental data for non-target compounds to determine matches between samples with similar compound distributions, discover (potential) coeluting compounds across multiple samples, and find patterns in between the samples using the statistical method of principal component analysis (PCA). To account for variances in the primary and secondary retention time attained from the analytical hardware of a compound in each sample, relative retention times were introduced. Relative retention times are determined by the target compounds and define a window for evaluation. The research presented in this thesis focuses on utilizing the mass spectra comparison algorithm by focusing on a pre-selected window of a GCxGC image, where an unknown compound has been identified between the PCB-101 and PCB-123 in collaboration with the FDA. The robust mass spectra comparison algorithm had a success rate of 93.5% when identifying matches. The remaining 6.5% can be reduced by only returning the best matching algorithm and limiting the percent change in the primary relative retention time to 3.5%. The PCA correlated the 51,143 unique relative retention time pairs of a GCxGC image to 71 principal components. The scores and coefficients of the principal components identify samples that differ substantially and samples with compounds in the same relative retention time locations. In conclusion, the mass spectral data comparison was performed as intended. The PCA did not indicate any strict patterns but identified locations to be investigated in future work.
Resistance and backlash from the perspective of PK-12 educational diversity, equity, and inclusion professionals (DEIP) in a predominantly White Midwestern state
Creators: name: Chaisson-Cárdenas, John-Paul
Publisher: name: University of Iowa
Year: 2022
Subjects: CRT
Diversity
Equity
Racism
Resistance
Schools
Education policy
public abstract

description: This pragmatic and exploratory Mixed Methods Research (MMR) study examined the phenomena of organizational diversity, equity, and inclusion (DEI) ‘resistance’ and ‘backlash’ as they affected diversity, equity, and inclusion professionals (DEIPs) and their efforts to promote DEI within the Iowa PK-12 education system. The study was conducted during a period when new anti-DEI legislation (HF802) had just become law. The topline findings of the study were that DEI resistance and DEI backlash, undergirded by colorblind systemic racism, exist in Iowa’s PK-12 schools; that performative diversity is the most common type of DEI resistance; and that resistance is most visible in suburban school districts. That said, this study also found that not all DEIPs are affected by DEI resistance and backlash in the same way. Specifically, DEIPs of color are much more likely to experience DEI resistance and backlash than their white counterparts.
Longitudinal fluorescence in situ hybridization reveals cytogenetic evolution in myeloma relapsing after autologous transplantation
Creators: name: Merz, Maximilian
name: Jauch, Anna
name: Hielscher, Thomas
name: Mai, Elias K.
name: Seckinger, Anja
name: Hose, Dirk
name: Bertsch, Uta
name: Blau, Igor W. [U.A.]
Publisher: name: Charité - Universitätsmedizin Berlin
Year: 2017
Subjects: subject: 600 Technik, Medizin, angewandte Wissenschaften::610 Medizin und Gesundheit

description: To investigate cytogenetic evolution after upfront autologous stem cell transplantation for newly diagnosed myeloma we retrospectively analyzed fluorescence in situ hybridization results of 128 patients with paired bone marrow samples from the time of primary diagnosis and at relapse. High-risk cytogenetic abnormalities (deletion 17p and/or gain 1q21) occurred more frequently after relapse (odds ratio: 6.33; 95% confidence interval: 1.86–33.42; P<0.001). No significant changes were observed for defined IGH translocations [t(4;14); t(11;14); t(14;16)] or hyperdiploid karyotypes between primary diagnosis and relapse. IGH translocations with unknown partners occurred more frequently at relapse. New deletion 17p and/or gain 1q21 were associated with cytogenetic heterogeneity, since some de novo lesions with different copy numbers were present only in subclones. No distinct baseline characteristics were associated with the occurrence of new high-risk cytogenetic abnormalities after progression. Patients who relapsed after novel agent-based induction therapy had an increased risk of developing high-risk aberrations (odds ratio 10.82; 95% confidence interval: 1.65–127.66; P=0.03) compared to those who were treated with conventional chemotherapy. Survival analysis revealed dismal outcomes regardless of whether high-risk aberrations were present at baseline (hazard ratio, 3.53; 95% confidence interval: 1.53–8.14; P=0.003) or developed at relapse only (hazard ratio, 3.06; 95% confidence interval: 1.09–8.59; P=0.03). Our results demonstrate cytogenetic evolution towards high-risk disease after autologous transplantation and underline the importance of repeated genetic testing in relapsed myeloma (EudraCT number of the HD4 trial: 2004-000944-26).
La Charte canadienne des droits et libertés et le domaine constitutionnel de l'expression commerciale.
Creators: name: St Louis, Marcouiller
Publisher: name: Université d'Ottawa / University of Ottawa
Year: 1994
Subjects: subject: Business Administration, Marketing.

description: La caractere fondamental de la liberte d'expression fut consacre par son enchassement a l'alinea 2 b) de la Charte canadienne des droits et libertes. L'interpretation large et liberale de l'alinea 2 b) fait en sorte que toute categorie d'expression est constitutionellement protegee. La liberte d'expression commerciale, constituant dorenavant une categorie d'expression beneficiant d'une telle protection, l'auteure s'est alors interessee a la delimitation de son domaine constitutionnel. Cette recherche de delimitation prendra ainsi l'aspect d'une demarche presentant trois phases differencies: dans le cadre de l'alinea 2 b), une delimitation par l'analyse des valeurs justifiant la liberte d'expression commerciale de meme qu'une delimitation de la sphere d'exercice de cette categorie d'expression et, en vertu de l'article premier, une delimitation par suite de l'approche contextuelle de cette forme de liberte. L'auteure pretend donc, qu'en definitive, c'est lors de l'analyse effectuee dans le cadre de l'article premier que se precise effectivement le domaine constitutionnel de l'expression commerciale. Elle souligne ainsi qu'en raison d'une approche contextuelle du caractere commercial de l'expression, autant lors de l'analyse de l'objectif de la regle de droit que lors de l'etude de l'atteinte minimale, le domaine constitutionnel de la liberte d'expression commerciale s'en trouve fortement reduit.
Fast NMDA transmission and non-linear synaptic interactions in a sensory feedback pathway.
Creators: name: Plant, James Richard.
Publisher: name: Université d'Ottawa / University of Ottawa
Year: 1994
Subjects: subject: Biology, Neuroscience.

description: Excitatory amino acid (EAA) neurotransmitters are extensively utilized at excitatory synapses throughout the vertebrate nervous system, with functional diversity being conferred by multiple forms of EAA receptors. Non-NMDA ionotropic EAA receptors (Kainate and AMPA) have typically been ascribed roles as mediators of fast neural transmission, with NMDA receptors hypothesized to contribute to slower processes such as temporal integration and synaptic plasticity. Employing extracellular field potentials, current source density analysis, and intrasomatic and dendritic recordings, the present studies demonstrated the relative contribution of non-NMDA and NMDA receptors to sensory feedback synapses within a highly stratified in vitro slice preparation of the electrosensory lateral line lobe (ELL) of the weakly electric fish Apteronotus leptorhynchus. Results confirmed a significant contribution of both a non-NMDA, and a fast NMDA component to EPSPs evoked by stimulation of the tractus stratum fibrosum (tSF) pathway. A voltage-dependent synaptically-mediated persistent Na$\sp+$ (slow) component of the tSF-evoked EPSP interacts with both fast NMDA and non-NMDA components, producing highly non-linear "thresholding" behaviour at the tSF synapses within the ventral molecular layer (VML) of the ELL. When viewed within the context of the in vivo physiology of this sensory feedback pathway, the complex response properties of the VML synapse suggests a rich diversity in EAA receptor/channel characteristics giving rise to dynamic functional properties which are consistent with its previously hypothesized role as a mediator of attentional processes within the electrosensory system.
Synthetic manipulation of azaheterocycles and their applications towards new bond transformations
Creators: name: Tun, Soe Lu
Publisher: name: University of Iowa
Year: 2025
Subjects: Aminal
Azaheterocycle
Organic Synthesis
Pyridine
Synthetic Methodology
public abstract

description: Discovering new methods that can be broadly applied in different synthetic settings is an important task in the synthetic organic community. In particular, synthetic methods focused on the construction and manipulation of small-molecule building blocks to provide access to widely distributed pharmacophores and bioactive fragments of larger molecules are especially important. Azaheterocyclic frameworks such as pyridines, dihydropyridines, imidazolidines and benzimidazolines are commonly found in bioactive small molecules and natural products. Additionally, simple derivatives of these ring systems can be used as synthetic intermediates for construction of more functionalized building blocks owing to their unique reactivities. Methods to effectively harness the reactivity of these important azaheterocycles in bond-forming transformations remain underdeveloped and underutilized. In this thesis research leading to the discovery and development of several new synthetic methods utilizing azaheterocyclic frameworks as reaction intermediates for construction of common small molecule building blocks is described
description: Synthetic applications of azaheterocycles possessing an aminal moiety as intramolecular hydride sources in palladium-catalyzed reductive Heck-type transformations were achieved. Imidazolidine aminals derived from 2-alkynylbenzaldehyde derivatives were used as substrates for palladium-catalyzed regio- and stereoselective reductive C-C coupling of alkynes with aryl iodide electrophiles. The resulting trisubstituted alkene products bearing benzanilide groups formed from heterocycle ring opening could be converted to carboxylic acid functional groups via saponification. Moreover, a styrene derivative linked to a benzimidazoline aminal was also found to undergo an analogous hydroarylation/benzimidazoline oxidation to give a diarylethane product.
description: The use of transient anhydrobases in construction of new C-C and C-S bond formations was also accomplished. 4-Alkylidene dihydropyridines generated in situ using 4-alkylpyridines and ethyl chloroformate were found to be reactive toward Eschenmoser’s salt to give geminally disubstituted 4-alkenyl pyridine derivatives. In addition, a simple and efficient sulfonylation reaction of 4-alkylidene dihydropyridines was achieved, leading to the straightforward synthesis of versatile 4-picolyl sulfones. In both cases the pyridine derivatives obtained using these processes could be further functionalized to assemble more decorated azaheterocyclic frameworks found in bioactive molecules.
Nuclear magnetic resonance in aluminum-manganese alloys.
Creators: name: Mau, A. E.
Publisher: name: Université d'Ottawa / University of Ottawa
Year: 1961
Subjects: subject: Physics, Electricity and Magnetism.

description: This thesis reports on the behavior of the n.m.r signal from Al27 in Al and Al Mn alloys. We have obtained values of 0.162 .002% for the Knight shift and of 8.65 .2 oe. for the line width in pure Al, in good agreement with values reported elsewhere. On alloying with Mn, decreases in intensity, line width and Knight shift are observed. This behavior is readily explained by nuclear electric quadrupole interactions. The small effective magnetic moment of the Mn ions seem to have a negligible effect on the line and from that point of view Al Mn behaves essentially like Al Mg and Al Zn which have been extensively studied recently.
Catheter-related blood stream infections in hemodialysis patients: a prospective cohort study
Creators: name: Thompson, Stephanie
name: Wiebe, Natasha
name: Klarenbach, Scott
name: Pelletier, Rick
name: Hemmelgarn, Brenda R.
name: Gill, John S.
name: Manns, Braden J.
name: Tonelli, Marcello
Publisher: name: BioMed Central
Year: 2018

description: Background: For people requiring hemodialysis, infectious mortality is independently associated with geographic distance from a nephrologist. We aimed to determine if differential management of catheter-related blood stream infections (CRBSIs) could explain poorer outcomes. Methods: We prospectively collected data from adults initiating hemodialysis with a central venous catheter between 2005 and 2015 in Alberta, Canada. We collected indicators of CRBSI management (timely catheter removal, relapsing bacteremia); frequency of CRBSIs; hospitalizations; predictors of CRBSIs, and bacteremia. We evaluated indicators and infectious episodes as a function of the shortest distance by road to the closest nephrologist’s practice: <50 (referent); 50–99; and ≥100 km. Results: One thousand one hundred thirty-one participants were followed for a median of 755 days (interquartile range (IQR) 219, 1465) and used dialysis catheters for a median of 565 days (IQR 176, 1288). Compared to the referent group, there was no significant difference in the rate ratio (RR) of CRBSI in the 50–100 and >100 km distance categories: RR 1.63; 95% confidence interval (CI) (0.91, 2.91); RR 0.84 (95% CI 0.44, 1.58); p = 0.87, respectively or in bacteremia: RR 1.42; (95% CI 0.83, 2.45); RR 0.79 (95% CI 0.45,1.39) p = 0.74, respectively. There were no differences in indicators of appropriate CRBSI management or hospitalizations according to distance. The overall incidence of CRBSIs was low (0.19 per 1000 catheter days) as was the frequency of relapse. Only liver disease was independently associated with CRBSI (RR 2.11; 95% CI 1.15, 3.86). Conclusions: The frequency and management of CRBSIs did not differ by location; however, event rates were low.
Interconnection of LANs through ISDN.
Creators: name: Liu, Zhengyu.
Publisher: name: Université d'Ottawa / University of Ottawa
Year: 1991
Subjects: subject: Engineering, Electronics and Electrical.

description: Network interconnection (internetworking) is an important issue in the area of computer communication. One of the purposes of internetworking is to allow communication to go beyond a single local area network (LAN). In this thesis, networks interconnection is studied. An internetworking device - (gate-way) is proposed to provide the capability of internetwork data transmission between LANs through an ISDN (Integrated Service Digital Network). This gateway is an application layer program which interfaces with the NetBIOS (Network Input Output System), a widely implemented interface between application programs and LANs in the IBM personal computer world. The NetBIOS interface is provided in both LAN and ISDN environments in a connection-oriented mode. A facility for file transfer and information exchange among LANs through ISDN is developed in such a way that it neither affects the existing network hardware and software available in both LANs and ISDN nor changes the mechanism of communication within a LAN. In particular, the emphasis is given to the specification, design and implementation of the gateway. In our model, the gateway is specified with a finite state machine. Based on the model, the gateway is designed by considering the issues of naming, name assigning, buffering, session handling, multi-session managing and error processing. A prototype of the gateway is implemented on a PC/XT computer with a LAN adapter, an ISDN adapter and the gateway program coded in "C". Performance benchmarks are conducted in terms of two factors: Message size and background traffic. These factors may affect the performance of internetwork data transmission. Finally, test results on different network conditions are given.
title: Impact of surgical correction of pectus excavatum on cardiac function
title: insights on the right ventricle. A cardiovascular magnetic resonance study
titleType: Subtitle
Creators: name: Töpper, Agnieszka
name: Polleichtner, Susanne
name: Zagrosek, Anja
name: Prothmann, Marcel
name: Traber, Julius
name: Schwenke, Carsten
name: Knobelsdorff-Brenkenhoff, Florian Von
name: Schaarschmidt, Klaus
name: Schulz-Menger, Jeanette
Publisher: name: Charité - Universitätsmedizin Berlin
Year: 2016
Subjects: subject: Right ventricle
subject: Pectus excavatum
subject: 600 Technik, Medizin, angewandte Wissenschaften::610 Medizin und Gesundheit

description: OBJECTIVES Pectus excavatum (PE) is often regarded as a cosmetic disease, while its effect on cardiac function is under debate. Data regarding cardiac function before and after surgical correction of PE are limited. We aimed to assess the impact of surgical correction of PE on cardiac function by cardiovascular magnetic resonance (CMR). METHODS CMR at 1.5 T was performed in 38 patients (mean age 21 ± 8.3; 31 men) before and after surgical correction to evaluate thoracic morphology, indices and its relation to three-dimensional left and right ventricular cardiac function. RESULTS Surgery was successful in all patients as shown by the Haller Index ratio of maximum transverse diameter of the chest wall and minimum sternovertebral distance [pre: 9.64 (95% CI 8.18–11.11) vs post: 3.0 (2.84–3.16), P < 0.0001]. Right ventricular ejection fraction (RVEF) was reduced before surgery and improved significantly at the 1-year follow-up [pre: 45.7% (43.9–47.4%) vs 48.3% (46.9–49.5%), P = 0.0004]. Left ventricular ejection fraction was normal before surgery, but showed a further improvement after 1 year [pre: 61.0% (59.3–62.7%) vs 62.7% (61.3–64.2%), P = 0.0165]. Cardiac compression and the asymmetry index changed directly after surgery and were stable at the 1-year follow-up [3.93 (3.53–4.33) vs 2.08 (1.98–2.19) and 2.36 (2.12–2.59) vs 1.38 (1.33–1.44), respectively; P < 0.0001 for both]. None of the obtained thoracic indices were predictors of the improvement of cardiac function. A reduced preoperative RVEF was predictive of RVEF improvement. CONCLUSIONS PE is associated with reduced RVEF, which improves after surgical correction. CMR has the capability of offering additional information prior to surgical correction.
Factors affecting collaboration among learners in a Web-based learning (WBL) environment.
Creators: name: Tiwari, Deborah E.
Publisher: name: Université d'Ottawa / University of Ottawa
Year: 2002
Subjects: subject: Education, Adult and Continuing.

description: Because Web-based Learning (WBL) is a relatively new educational environment, limited research has been undertaken in exploring the factors that affect learners and instructors in WBL. (Trentin, 2001; Muirhead, 2001; Sloffer, Dueber & Duffy, 1999; Gabriel, 1999; Land & Hannafin, 1997; Mayer, 1997; Newman, Webb & Cochrane, 1996). How WBL learners co-construct knowledge through collaboration with each other under the guidance of an instructor has not been examined in-depth. Although there is literature that examines general factors affecting learners in the WBL environment, there is little research that reveals why these factors are significant to the process of constructing learning, or how they impact learners' ability to collaborate in a WBL environment (Trentin, 2001; Carstens & Worsfold, 2000; Sloffer, Dueber & Duffy, 1999; Gabriel, 1999; Edelson, Pia, & Gomez, 1996; Silva & Breuleux, 1994). This qualitative single case study was comprised of a WBL course delivered to a group of public sector employees in various locations around the world, and focused on their WBL experiences. An instructor, a course administrator, a Website manager, and eight learners volunteered to participate in the case study. Data from the study were analyzed in order to provide in-depth descriptions of factors affecting collaboration among learners in a course delivered solely through WBL. This study revealed factors that primarily prevented learners from collaborating among themselves as they constructed their learning in a Web-based environment. Some factors that could have facilitated collaboration were evident; however, the barriers to it were insurmountable in this case. The findings of this study have illuminated findings of previous studies, and contributed new understandings. Recommendations for WBL processes and components will assist WBL instructors and designers to facilitate collaboration and knowledge co-construction among learners.
Acute effects of methylphenidate on energy balance in healthy men and women
Creators: name: Lorello, Claudio
Publisher: name: Université d'Ottawa / University of Ottawa
Year: 2007
Subjects: subject: Biology, Physiology.

description: This thesis attempts to clarify the impact of methylphenidate hydrochloride (MPH) on key components involved in energy balance, specifically, resting energy (REE) and postprandial energy expenditure (PEE), substrate oxidation, energy intake and appetite. A double-blind, randomized, placebo-controlled, cross-over study was conducted to measure any differences between MPH and placebo treatments. MPH and/or placebo were administered orally (0.5 mg/kg) to seven healthy males (age: 19-37y, BMI: 19.8-30.5 kg/m2, body fat: 8-1-23.6%) and seven healthy females (age: 20-26y, BMI: 20.6-32.4 kg/m2, body fat: 18.8-42.1%). Indirect calorimetry was used to calculate energy expenditure variables while energy intake variables were measured during an ad libitum buffet-type lunch. Body composition was measured with dual energy x-ray absorptiometry (DEXA). The post-prandial energy expenditure (PEE) phase was measured over a 3-hour period. Vital signs (BP and HR) were assessed pre- and post-administration of MPH or placebo in every session. Results demonstrate that resting energy expenditure (REE) during MPH treatment increased over values obtained during the placebo session (1727.4 kcal/24h vs. 1612.3 kcal/24h, p<0.001). No changes in fasting respiratory exchange ratio (RER) were noted; however, significant decreases in post-prandial RER were found during the 30- to 90-min time interval (p<0.01). Although PEE continually decreased with time as expected, MPH treatment resulted in significantly greater PEE values at 90-min (MPH: 1946.9 kcal/24h +/- 290.0 vs. placebo: 1856.5 kcal/24h +/- 260.3, p<0.005). No statistical differences in side effects were noted between MPH and placebo treatment. Methylphenidate hydrochloride seemed to have a significant affect on energy expenditure and energy intake variables resulting in a potential net caloric deficit without significant changes in vital signs commonly associated with psychostimulant use. Keywords: Methylphenidate hydrochloride, energy balance, thermic effect of food, dual energy x-ray absorptiometry
Survivable IP over optical transport networks
Creators: name: Maamoun, Khaled
Publisher: name: Université d'Ottawa / University of Ottawa
Year: 2007
Subjects: subject: Engineering, Electronics and Electrical.

description: Survivability strategies for a single network layer have been investigated for many years in the research and development of communication networks. Some of these networks already have available standards for protection methods and techniques (e.g. SONET). However, using only one survivability technique running in a single-layer is not always the optimal solution if we want to achieve a certain level of QoS for all services without increasing the cost of their use. One of the most promising solutions for overcoming this problem is to use multi-layer survivability techniques running in different network layers. The use of multi-layer survivability strategies requires precise definitions of the survivability functionalities that need to be allocated at each layer and the coordination between the network layers. This thesis investigates survivability schemes for optical networks that rely only on a single layer, as well as for those that have more than one layer survivability functions and uses different approaches to solve QoS survivability related problems. We have simulated the restoration process of single transport layer: IP; ATM; SONET and OTN, which have been analyzed by similar studies. Also, we have simulated the process of the multi-layer restoration schemes for previously analyzed IP/SONET, IP/OTN and IP-MPLS/OTN by using the hold-off timer concept. We have extended their restoration concept and applied it for IP/OTN and ATM/SONET restoration schemes. Further more, we have introduced IP Restoration/OTN Protection combined multi-layer survivability, IP Restoration/SONET Protection combined multi-layer survivability and IP-MPLS Protection and Restoration/OTN Protection combined multi-layer survivability. In this thesis, we have combined the analyses with simulations to form a comprehensive study for the IP over OTN survivability across different architectures. The study focuses on four of the most commonly used network architectures of the IP over OTN architecture possibilities: IP/POS/OTN; IP/GbE/OTN; IP-MPLS/OTN, and the traditional, still commonly used IP/ATM/SONET/OTN.
Sequential Detection of Physical Network Coding in the Presence of Phase Asynchrony
Creators: name: Marchand, Philippe
Publisher: name: Université d'Ottawa / University of Ottawa
Year: 2010
Subjects: subject: Engineering, Electronics and Electrical.

description: Physical-Layer Network Coding has the potential to greatly increase the throughput of wireless networks. This novel method of operating networks is based on the coherent demodulation of signals containing two waveforms transmitted synchronously. In this thesis, we explore the problems imposed by the physical constraints, in particular the carrier phase offset of the two signals making up the physical network code (PNC). For QPSK transmissions, coherent demodulation of the resulting symbols will be penalized by a decreased minimum distance resulting from carrier phase misalignment. Based on the observation that binary signalling is not affected by this asynchrony, we propose a modulation framework which enables the coherent demodulation of PNC symbols with arbitrary phase offsets. The framework is based on bit-offset modulation by the sources and Maximum-Likelihood Sequence Detection by the receiver. The spread in receiver performance for a range of phase offset PNC signals is less than 2dB at moderate SNR for transmissions at a rate of 2 bits/symbol. These results confirm that the proposed solution is able to solve the problem of phase asynchrony for PNC QPSK and higher order modulations.