Asymptotic formulas for curve operators in TQFT

Topological quantum field theories with gauge group $\textrm{SU}_2$ associate to each surface with marked points $\Sigma$ and each integer $r>0$ a vector space $V_r (\Sigma)$ and to each simple closed curve $\gamma$ in $\Sigma$ an Hermitian operator $T_r^{\gamma}$ acting on that space. We show that the matrix elements of the operators $T_r^{\gamma}$ have an asymptotic expansion in orders of $\frac{1}{r}$, and give a formula to compute the first two terms in terms of trace functions, generalizing results of March\'e and Paul

Distributions of TOP, TON and TOC in the North Pacific subtropical gyre: Implications for nutrient supply in the surface ocean and remineralization in the upper thermocline

We report measurements of total organic phosphorus, nitrogen, and carbon (TOP, TON, and TOC) along a meridional transect in the eastern subtropical North Pacific. In the surface waters, TOP and TON comprise 83% and 98% of the total dissolved phosphorus and nitrogen pools, respectively. Between the equatorial region and the subtropical gyre, there is a distinct gradient in surface TOP of about 0.25 µM, but very little gradient in TON. TOC increases by nearly 30 µM across the same region. Meridional advection of TOP along its gradient via Ekman transport can provide 40-80% of the phosphorus necessary to supply present estimates of particulate phosphorus export from the subtropical gyre. Mass balance requires an additional input of nitrogen to the surface waters to fuel particulate nitrogen export. This input is likely supported by nitrogen fixation. As dissolved organic matter (DOM) is degraded along isopycnals that outcrop within the subtropical gyre, TOP and TOC are consumed more rapidly than TON. TOC and TON contribute 70% and 20% to organic matter remineralization along these isopycnals, respectively, and the C:N ratio for remineralization is 30 ± 10. In contrast, along isopycnals that outcrop to the north of the gyre, both TOC and TON contribute 30% to organic matter remineralization and the C:N ratio is 8 ± 1. Our results suggest that excess TOC, produced within the surface waters of the subtropical gyre during nitrogen fixation, is highly labile and dominates respiration along shallow isopycnals. Preferential remineralization of TOC relative to TON within the gyre results in a negative preformed nitrate signal in the upper thermocline, and may establish a feedback between upper thermocline DOM remineralization and surface ocean DOM production that maintains nitrogen fixation in the surface waters

Détermination des facteurs bénéfiques et néfastes à la récupération locomotrice à la suite d’une section spinale complète chez la souris

Différents modèles animaux ont permis de déterminer le rôle des réseaux locomoteurs spinaux dans la production de la locomotion à la suite d’une lésion de la moelle épinière (LM pour lésion médullaire). De plus, il a été démontré que des interventions ciblant leur activation améliorent la récupération en favorisant leur adaptation fonctionnelle et structurale par des mécanismes plastiques tels que ceux impliqués dans l’apprentissage et la mémoire. L’entraînement locomoteur permet ainsi d’améliorer progressivement la récupération locomotrice médiée par les réseaux locomoteurs spinaux, incluant lors de section complète de la moelle épinière. En plus de l’entraînement, une multitude de facteurs cliniques, des processus associés à la blessure elle-même ou à son traitement, sont susceptibles d’influencer l’activation des réseaux spinaux ou leur potentiel d’adaptation plastique. Afin d’optimiser la récupération fonctionnelle, l’impact de ces facteurs et les mécanismes impliqués doivent être clarifiés. L’objectif de cette thèse est d’évaluer l’influence de l’entraînement sur la récupération fonctionnelle dans deux conditions de réadaptation spécifiques : 1) lors de présence d’inflammation musculo-squelettique lié à l’étiologie traumatique de la LM et 2) lors de traitement combinant entraînement et buspirone, un agoniste sérotoninergique en étude préclinique pour ses effets pro-locomoteurs. La première condition à l’étude, la présence d’inflammation musculo-squelettique, est une comorbidité fréquente de la LM et est associée à un pire pronostic qu’en absence d’inflammation. Considérant le rôle des réseaux spinaux dans le traitement de l’information sensorielle et nociceptive et de leur contribution à la régulation de la locomotion générée par les circuits spinaux, leur influence sur la récupération locomotrice devait être définit. En utilisant un modèle de souris avec une section mi-thoracique complète, nous avons évalué l’impact d’une réaction inflammatoire persistante par injection d’adjuvant de Freund (CFA) dans les muscles lombaires sous-lésionnels sur le rétablissement du rythme et patron locomoteur, en présence ou non d’entraînement (étude 1). Nos résultats montrent que l’inflammation des muscles lombaires perturbe la récupération locomotrice. Les afférences sensorielles jouent un rôle important dans le rétablissement de la locomotion en modulant l’activité du CPG et en influençant l’excitabilité de circuits réflexes impliqués dans la locomotion. En évaluant les changements d’excitabilité ii du réflexe de Hoffmann associés à l’injection de CFA à la suite d’une section, nous avons observé que l’inflammation des muscles lombaires induit un état de désinhibition spinale dans les premiers jours post-injection (étude 2). Toutefois, cet effet ne perdurait pas pour toute la durée de la réponse neuroinflammatoire tel qu’évaluée par l’activation de la microglie dans la moelle épinière lombaire (étude 3) ce qui suggère que les déficits locomoteurs associés au CFA s’expliquent au moins partiellement par un mécanisme indépendant de la désinhibition spinale. La deuxième condition à l’étude, la combinaison d’un traitement à la buspirone au protocole d’entraînement, présente un réel potentiel thérapeutique selon un essai préclinique récent. Toutefois, son influence sur les réseaux locomoteurs spinaux est inconnue, de même que l’influence de l’utilisation de la buspirone sur l’adaptation des réseaux spinaux par l’entraînement. En utilisant notre modèle de souris ayant une section spinale complète, nous avons montré que la buspirone facilite l’activation des réseaux locomoteurs spinaux (étude 4). Cependant, cette facilitation était associée à des changements limités de la récupération médiée par l’entraînement. En comparant l’impact de la buspirone chez des animaux aux statuts fonctionnels différents (récupération symétrique partielle et récupération asymétrique) causés par un paradigme de lésion distinct (section complète et hémisection), des changements dans la récupération médiée par l’entraînement ont été observés, ce qui suggère que l’impact positif de la buspirone sur la récupération locomotrice est causé, au moins en partie, par la favorisation d’adaptations plastiques. En conclusion, cette thèse décrit deux conditions qui modifient de façon opposée la récupération locomotrice régulée par les réseaux locomoteurs spinaux. Ces découvertes renforcent le concept que les réseaux locomoteurs spinaux sont plastiques et jouent un rôle primordial dans la récupération locomotrice et ajoutent de nouvelles connaissances sur les facteurs qui en influencent la réadaptation.Locomotor spinal networks contribution to locomotor recovery has been described in various animal models of spinal cord injury (SCI). It is now assumed that these networks are plastic and will re-express, to some extent, locomotion by hosting activity-dependent adaptation similar to those observed in motor learning and memory. Thus, locomotor training promotes behavioral recovery mediated by locomotor spinal networks after a SCI, including after a complete transection and disconnection from the brain. In addition to training, various factors can exert beneficial or detrimental influence on locomotor spinal networks activity and plasticity, including factors associated with the traumatic origin of spinal injury itself or its pharmacological treatment. In order to direct plasticity toward adaptation and promote recovery, the influence of such factors must be clarified. The objectives of the present thesis is to determine the contribution of training to recovery in two specific conditions of rehabilitation: 1) in presence of musculoskeletal inflammation related to the traumatic etiology of SCI and 2) in combination with a pharmacological intervention, administration of the 5HT agonist buspirone, used in preclinical studies to facilitate locomotor activity. The first condition, the presence of musculoskeletal inflammation, is frequently observed in patients after a SCI and is associated with poor functional recovery. Considering the role of spinal networks in sensory processing and the selective recruitment by nonnociceptive and nociceptive afferents of reflex pathways implicated in locomotion, the impact of inflammation on locomotor recovery must be determined. In a model of complete transection in mice, we evaluate the impact of lumbar muscle inflammation induced by intramuscular complete Freund adjuvant (CFA) injection on locomotor recovery mediated by spinal networks, with or without locomotor training. Our results show that lumbar muscle inflammation hindered locomotor recovery (study 1). In a second experiment, we examined if CFA injection changed sensory transmission to spinal cord by measuring the evolution of Hoffmann reflex frequencydependent depression, which is progressively attenuated after spinal transection. We found that lumbar muscle inflammation induced a short term suppression of the Hoffmann reflex frequency-dependent depression, thereby altering spinal excitability (study 2). However, this short term change in excitability did not match the temporal course of locomotor deficits and iv central neuroinflammatory response as measured with the enhanced presence of microglia in spinal cord, suggesting that inflammation-induced locomotor deficits rely at least partially on mechanism independent of spinal excitability (study 3). The second condition under investigation, the use of buspirone to enhance locomotor recovery after a SCI, shows great therapeutic potential. Results from a preclinical trial on SCI patients show that it can enhance locomotor activity, but it is not known if it does so by reactivating dormant descending pathways or locomotor spinal networks. Using our model of complete transection in mice, we showed that buspirone strongly activates locomotor spinal networks and allow near full expression of locomotion on day 2 post-transection (study 4). However, this facilitation was associated with limited long term effect when combined with training. Improved long term effect of buspirone depending on residual function after transection (partial vs absent function) caused by different lesion paradigms (hemisection preceding transection vs transection only) suggests that buspirone promotes recovery by enhancing use-dependent plastic changes. In conclusion, this thesis describes two conditions that influence locomotor recovery mediated by spinal networks oppositely. These findings give new insights on the role of locomotor spinal networks plasticity in recovery after a SCI including spinal transection and provide evidence both beneficial and detrimental factors contributes to functional rehabilitation

Calibration of channel depth and friction parameters in the LISFLOOD-FP hydraulic model using medium resolution SAR data and identifiability techniques

Single satellite synthetic aperture radar (SAR) data are now regularly used to estimate hydraulic model parameters such as channel roughness, depth and water slope. However, despite channel geometry being critical to the application of hydraulic models and poorly known a priori, it is not frequently the object of calibration. This paper presents a unique method to simultaneously calibrate the bankfull channel depth and channel roughness parameters within a 2-D LISFLOOD-FP hydraulic model using an archive of moderate-resolution (150 m) ENVISAT satellite SAR-derived flood extent maps and a binary performance measure for a 30 × 50 km domain covering the confluence of the rivers Severn and Avon in the UK. The unknown channel parameters are located by a novel technique utilising the information content and dynamic identifiability analysis (DYNIA) (Wagener et al., 2003) of single and combinations of SAR flood extent maps to find the optimum satellite images for model calibration. Highest information content is found in those SAR flood maps acquired near the peak of the flood hydrograph, and improves when more images are combined. We found that model sensitivity to variation in channel depth is greater than for channel roughness and a successful calibration for depth could only be obtained when channel roughness values were confined to a plausible range. The calibrated reach-average channel depth was within 0.9 m (16 % error) of the equivalent value determined from river cross-section survey data, demonstrating that a series of moderate-resolution SAR data can be used to successfully calibrate the depth parameters of a 2-D hydraulic model

L2 perception of Spanish palatal variants across different tasks

While considerable dialectal variation exists, almost all varieties of Spanish exhibit some sort of alternation in terms of the palatal obstruent segments. Typically, the palatal affricate [ɟʝ] tends to occur in word onset following a pause and in specific linear phonotactic environments. The palatal fricative [ʝ] tends to occur in syllable onset in other contexts. We show that listeners’ perceptual sensitivity to the palatal alternation depends upon the task and exposure to Spanish input. For native Spanish listeners, the palatal alternation boosts segmentation accuracy on an artificial speech segmentation task and also reduces latencies on a phonotactically-conditioned elision task. L2 Spanish listeners, on the other hand, only benefit from the palatal alternation in the second task. These results suggest that while Spanish L2 learners benefit from the presence of the alternation in linear phonotactic terms, this benefit does not carry over to a more abstract segmentation task

Development of Science-Based Permitting Guidance for Geological Sequestration of CO2 in Deep Saline Aquifers Based on Modeling and Risk Assessment

Underground carbon storage may become one of the solutions to address global warming. However, to have an impact, carbon storage must be done at a much larger scale than current CO{sub 2} injection operations for enhanced oil recovery. It must also include injection into saline aquifers. An important characteristic of CO{sub 2} is its strong buoyancy--storage must be guaranteed to be sufficiently permanent to satisfy the very reason that CO{sub 2} is injected. This long-term aspect (hundreds to thousands of years) is not currently captured in legislation, even if the U.S. has a relatively well-developed regulatory framework to handle carbon storage, especially in the operational short term. This report proposes a hierarchical approach to permitting in which the State/Federal Government is responsible for developing regional assessments, ranking potential sites (''General Permit'') and lessening the applicant's burden if the general area of the chosen site has been ranked more favorably. The general permit would involve determining in the regional sense structural (closed structures), stratigraphic (heterogeneity), and petrophysical (flow parameters such as residual saturation) controls on the long-term fate of geologically sequestered CO{sub 2}. The state-sponsored regional studies and the subsequent local study performed by the applicant will address the long-term risk of the particular site. It is felt that a performance-based approach rather than a prescriptive approach is the most appropriate framework in which to address public concerns. However, operational issues for each well (equivalent to the current underground injection control-UIC-program) could follow regulations currently in place. Area ranking will include an understanding of trapping modes. Capillary (due to residual saturation) and structural (due to local geological configuration) trappings are two of the four mechanisms (the other two are solubility and mineral trappings), which are the most relevant to the time scale of interest. The most likely pathways for leakage, if any, are wells and faults. We favor a defense-in-depth approach, in which storage permanence does not rely upon a primary seal only but assumes that any leak can be contained by geologic processes before impacting mineral resources, fresh ground water, or ground surface. We examined the Texas Gulf Coast as an example of an attractive target for carbon storage. Stacked sand-shale layers provide large potential storage volumes and defense-in-depth leakage protection. In the Texas Gulf Coast, the best way to achieve this goal is to establish the primary injection level below the total depth of most wells (>2,400 m-8,000 ft). In addition, most faults, particularly growth faults, present at the primary injection level do not reach the surface. A potential methodology, which includes an integrated approach comprising the whole chain of potential events from leakage from the primary site to atmospheric impacts, is also presented. It could be followed by the State/Federal Government, as well as by the operators