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Abstract Objectives To assess the added value of gadoxetic-acid–enhanced T1-weighted magnetic resonance Cholangiography (T1W-MRC) including controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA)-Volumetric Interpolated Breathhold (VIBE) technique compared to T2-weighted MR Cholangiography (T2W-MRC) in depicting biliary anatomy in potential living liver donors. Methods Eighty-five potential donors including 34 men with a mean age of 35.6 years (range, 18–55 years) and 51 women with a mean age of 36.7 years (range, 23–57 years), were enrolled in this ethics-approved retrospective study. Image quality for depiction of bile ducts was evaluated by two readers in consensus in 3 separate reading sessions: 1) T2W-MRC alone, 2) T1W-MRC alone (including CAIPI-VIBE and generalized autocalibrating partially parallel acquisitions (GRAPPA)-VIBE techniques, and 3) combined T1W/T2W-MRC. Accuracy of T2W-MRC, T1W-MRC, and combined T1W/T2W-MRC for the identification/classification of the biliary variants was calculated using intraoperative cholangiogram (IOC) as the reference standard. Image quality and reader diagnostic confidence provided by CAIPI-VIBE technique was compared with GRAPPA-VIBE technique. Datasets were compared using the Wilcoxon signed-rank test. Results Image quality for depiction of the bile ducts was significantly superior in the combined T1W/T2W-MRC group, when compared to each of T2W-MRC and T1W-MRC groups independently (P value = 0.001–0.034). The combination of CAIPI-VIBE and GRAPPA-VIBE was superior compared to each of the sequences individually. The accuracy of T2W-MRC and T1W-MRC was 93% and 91%, respectively. T1W-MRC depicted four biliary variants better than T2W-MRC. Two variants not well seen in T2W-MRC were clearly shown on T1W-MRC. Conclusion Gadoxetic-acid–enhanced T1W-MRC and conventional T2W-MRC techniques are complementary for depiction of biliary variants in potential liver donors and the combination of the two improves the results. The combination of CAIPI-VIBE and GRAPPA-VIBE techniques appear to be complementary for optimal diagnostic yield of T1W-MRC.

Let k be a base field, K be a field containing k and L/K be a field extension of degree n. The essential dimension ed(L/K) over k is a numerical invariant measuring "the complexity" of L/K. Of particular interest is $\tau$(n) = max { ed(L/K) | L/K is a separable extension of degree n}, also known as the essential dimension of the symmetric group $S_n$. The exact value of $\tau$(n) is known only for n $\leq$ 7. In this paper we assume that k is a field of characteristic p > 0 and study the essential dimension of inseparable extensions L/K. Here the degree n = [L:K] is replaced by a pair (n, e) which accounts for the size of the separable and the purely inseparable parts of L/K respectively, and \tau(n) is replaced by $\tau$(n, e) = max { ed(L/K) | L/K is a field extension of type (n, e)}. The symmetric group $S_n$ is replaced by a certain group scheme $G_{n,e}$ over k. This group is neither finite nor smooth; nevertheless, computing its essential dimension turns out to be easier than computing the essential dimension of $S_n$. Our main result is a simple formula for \tau(n, e). Comment: 18 pages

Simulated sensor data from active and passive sensors has numerous applications in target detection and tracking. Simulated data is particularly useful in performance evaluation of target tracking algorithms where the ground truth of a scenario must be known. For real sensor data it is impossible to know the ground truth so simulated data must be used. This paper discusses existing methods for simulation of data from active sensors and proposes a method that builds on existing techniques from the field of computer graphics. An extension to existing methods is proposed to accommodate the simulation of active sensor data for which timing and frequency information is required in addition to intensity. Results from an existing method of active sensor data simulation are compared to the results of the proposed method. Additionally, a cloud computing framework is proposed and its scalability evaluated to address the fairly large computational load of such a simulation. Thesis Master of Applied Science (MASc)

Dam building and reservoir operations alter the downstream hydrological regime, and as a result, affect the health of the river aquatic ecosystem, particularly for large-scale cascade reservoirs. This study investigated the impact of the Gezhouba Reservoir (GR) and the Three Gorges Reservoir (TGR) on the spawning conditions of two critical taxa, i.e., the endemic four major carps and the endangered Chinese sturgeon in the Yangtze River. We analyzed the flow, sediment, and thermal regime in these two taxa spawning seasons and compared their features between the predam and postdam periods. Our results revealed that the GR and the TGR had altered the frequency distributions of flow, sediment, and water temperature to different degrees, with the impact by the GR on the carps and Chinese sturgeon ranked as water temperature > water temperature. For the GR, the satisfying degree of the suitable flow and water temperature of the carps increased, whilst the suitable flow, sediment, and water temperature for the Chinese sturgeon decreased. These changes in TGR showed a significant ascending (descending) trend in the suitable flow (water temperature) for the carps, and a clear decreasing trend in the flow, sediment, and temperature for Chinese sturgeon. Both the TGR and the GR had negative impacts on the spawning of these two taxa in terms of the rising/falling flow characteristics. flow, and the effect of the TGR on these two taxa were ordered as flow > water temperature, sediment > water temperature > flow, sediment > flow >

Managing the thread-level parallelism (TLP) of GPGPU applications by limiting it to a certain degree is known to be effective in improving the overall performance. However, we find that such prior techniques can lead to sub-optimal system throughput and fairness when two or more applications are co-scheduled on the same GPU. It is because they attempt to maximize the performance of individual applications in isolation, ultimately allowing each application to take a disproportionate amount of shared resources. This leads to high contention in shared cache and memory. To address this problem, we propose new application-aware TLP management techniques for a multi-application execution environment such that all co-scheduled applications can make good and judicious use of all the shared resources. For measuring such use, we propose an application-level utility metric, called effective bandwidth, which accounts for two runtime metrics: attained DRAM bandwidth and cache miss rates. We find that maximizing the total effective bandwidth and doing so in a balanced fashion across all co-located applications can significantly improve the system throughput and fairness. Instead of exhaustively searching across all the different combinations of TLP configurations that achieve these goals, we find that a significant amount of overhead can be reduced by taking advantage of the trends, which we call patterns, in the way application's effective bandwidth changes with different TLP combinations. Our proposed pattern-based TLP management mechanisms improve the system throughput and fairness by 20% and 2x, respectively, over a baseline where each application executes with a TLP configuration that provides the best performance when it executes alone.

Backgrounds: Severe influenza infection causes substantial morbidity and mortality worldwide and remains an important threat to global health. This study addressed factors related to treatment outcomes in subjects of complicated influenza infection with acute respiratory distress syndrome (ARDS) during the Taiwan epidemic in the Spring of 2016. Methods: This is a retrospective study conducted by Taiwan Severe Influenza Research Consortium (TSIRC), including eight tertiary referral medical centers. Patients with virology-proven influenza infection admitted to intensive care unit (ICU) between January and March 2016 were included for analysis. Results: We identified 263 patients with complicated influenza infection who fulfilled ARDS criteria; the mean age was 59.8 ± 14.6 (years), and 66.1% (166/263) were male. Type A influenza (77.9%, 205/263) virus was the main pathogen during this epidemic. The 30-day mortality rate was 23.2% (61/263). The mean tidal volume (VT) in the first three days after intubation was greater than 8 mL/kg of predicted body weight (PBW). Patients whose first measured VT was >8 mL/kg PBW had an increased 30-day mortality (p = 0.04, log-rank test). In a multivariate Cox proportional hazard regression model, an increase of 1 mL/kg PBW of first VT was associated with 26.1% increase in 30-day mortality (adjusted hazard ratio 1.261, 95% confidence interval [CI] 1.072–1.484, p < 0.01). Conclusion: First tidal volume, shortly after intubation, greater than 8 mL/kg PBW is an independent risk factor for mortality in complicated influenza infection with ARDS. Timely recognition of ARDS with strict adherence to protective ventilation strategy of lowering VT may be important in reducing mortality. Keywords: Influenza, Acute respiratory distress syndrome, Tidal volume

AbstractFamily history was one of the major risk factors for developing adverse health outcomes such as metabolic syndrome (MetS), type 2 diabetes mellitus (DM) and hypertension (HTN). Our aim was to examine the relationship between different family histories and cardiometabolic events, including DM, stroke, myocardial infarction (MI), and HTN. Participants who attended the health examinations at the Tri-Service General Hospital from 2010 to 2016 were enrolled in the study and were categorized into four groups by representing different family history. A multivariable logistic regression model was used for the associations between various family history with the cardiometabolic events. Subjects with family history of DM were divided into quartiles by percentage body fat (PBF) to be analyzed for these adverse outcomes. In the cross-sectional analysis, subjects with family history of DM had significant association with MetS (OR = 1.34 [95%CI: 1.17–1.54]) and DM (OR = 3.03 [95%CI: 2.44–3.76]), and those with family history of HTN were positively associated with HTN (OR = 1.60 [95%CI: 1.41–1.81]). Notably, those with family history of DM in higher PBF quartiles had substantially increased association of cardiometabolic events (MetS: OR = 15.20 [95%CI: 9.87–23.39]; DM: OR = 3.35 [95%CI: 1.91–5.90]; HTN: 2.81 [95%CI: 1.84–4.29]). Individuals with family history of DM were positively associated with MetS and DM, and those with family history of HTN was associated with HTN. Family history assessment was requested especially in obese population for screening adverse health outcomes.

Aim This study aims to explore the experiences of carers of children with cerebral palsy living in rural areas of Ghana who have received no rehabilitation services. Background Cerebral palsy is the most common chronic disability from childhood, which needs lifelong rehabilitation. Most of the population living in rural communities in Ghana have virtually no form of rehabilitation services for their chronic disabling conditions. Caring for children with disability are known to be challenging especially when coupled with environmental challenges in rural communities. Results Purposive and snowball techniques were used to recruit 12 carers, age 22 to 68 years, of children with cerebral palsy aged 7 to 15 years. Two main themes, developing personal beliefs to support the caregiving role and the demands that shape the experience of caring, emerged from six subthemes and 25 theme clusters of the narratives of the carers. The essential structure of the phenomenon demonstrated the complex interaction of personal and environmental factors in harmony with the actual demands to influence the experiences of participants positively or negatively. Positively, carers achieved coping, committed to caring, hoped for the future, and accepted the condition. However, negatively, carers described the triggering factors of feeling of despair and sorrow as frustration and lack of understanding of the condition, felt stigmatized, and perceived the child was going through pain and suffering. Conclusions Carers derived strength from their religious and spiritual beliefs to balance the demands of caregiving. Findings could be used as basis for developing interventions to support carers and inform new strategies for rehabilitation service and sensitization of community members about inclusion of children with disabilities.

Adverse outcome pathways (AOPs) describe how a measurable sequence of key events, beginning from a molecular initiator, can lead to an adverse outcome of relevance to risk assessment. An AOP is modular by design, comprised of four main components: (1) a Molecular Initiating Event (MIE), (2) Key Events (KEs), (3) Key Event Relationships (KERs) and (4) an Adverse Outcome (AO).Here, we illustrate the utility of the AOP concept through a case example in the field of ionizing radiation, using the Organisation for Economic Cooperation and Development (OECD) Users' Handbook. This AOP defines a classic targeted response to a radiation insult with an AO of lung cancer that is relevant to radon gas exposure.To build this AOP, over 500 papers were reviewed and categorized based on the modified Bradford-Hill Criteria. Data-rich key events from the MIE, to several measurable KEs and KERs related to DNA damage response/repair were identified.The components for this AOP begin with direct deposition of energy as the MIE. Energy deposited into a cell can lead to multiple ionization events to targets such as DNA. This energy can damage DNA leading to double-strand breaks (DSBs) (KE1), this will initiate repair activation (KE2) in higher eukaryotes through mechanisms that are quick and efficient, but error-prone. If DSBs occur in regions of the DNA transcribing critical genes, then mutations (KE3) generated through faulty repair may alter the function of these genes or may cause chromosomal aberrations (KE4). This can impact cellular pathways such as cell growth, cell cycling and then cellular proliferation (KE5). This will form hyperplasia in lung cells, leading eventually to lung cancer (AO) induction and metastasis. The weight of evidence for the KERs was built using biological plausibility, incidence concordance, dose-response, time-response and essentiality studies. The uncertainties and inconsistencies surrounding this AOP are centered on dose-response relationships associated with dose, dose-rates and radiation quality.Overall, the AOP framework provided an effective means to organize the scientific knowledge surrounding the KERs and identify those with strong dose-response relationships and those with inconsistencies. This case study is an example of how the AOP methodology can be applied to sources of radiation to help support areas of risk assessment.