Comparison of magnetic resonance spectroscopy, proton density fat fraction and histological analysis in the quantification of liver steatosis in children and adolescents

AIM: To establish a threshold value for liver fat content between healthy children and those with non-alcoholic fatty liver disease (NAFLD) by using magnetic resonance imaging (MRI), with liver biopsy serving as a reference standard. METHODS: The study was approved by the local ethics committee, and written informed consent was obtained from all participants and their legal guardians before the study began. Twenty-seven children with NAFLD underwent liver biopsy to assess the presence of nonalcoholic steatohepatitis. The assessment of liver fat fraction was performed using MRI, with a high field magnet and 2D gradient-echo and multiple-echo T1-weighted sequence with low flip angle and single-voxel point-resolved ¹H MR-Spectroscopy (¹H-MRS), corrected for T1 and T2* decays. Receiver operating characteristic curve analysis was used to determine the best cut-off value. Lin coefficient test was used to evaluate the correlation between histology, MRS and MRI-PDFF. A Mann-Whitney U-test and multivariate analysis were performed to analyze the continuous variables. RESULTS: According to MRS, the threshold value between healthy children and those with NAFLD is 6%; using MRI-PDFF, a cut-off value of 3.5% is suggested. The Lin analysis revealed a good fit between the histology and MRS as well as MRI-PDFF. CONCLUSION: MRS is an accurate and precise method for detecting NAFLD in children

Adaptive closed-loop control for post-capture spacecrat de-tumbling with real-time inertia estimation using dual-filter UKF

LAUREA MAGISTRALEQuesto studio si concentra sulla fase post-cattura di una missione di Servizio in Orbita (In-Orbit Servicing) di un veicolo spaziale bersaglio in rotazione incontrollata. Le metodologie attuali per le operazioni sopra menzionate si basano su diverse tecnologie, che spesso richiedono una comprensione chiara dei parametri inerziali e delle proprietà di massa del veicolo spaziale bersaglio. Inoltre, queste metodologie raramente considerano un modello a ciclo chiuso in cui le dinamiche accoppiate vengono valutate insieme agli algoritmi di controllo e stima dei parametri. Questo lavoro ha l'obiettivo di eseguire la stabilizzazione (de-tumbling) e stimare i parametri di inerzia sconosciuti del bersaglio per ottenere una conoscenza più approfondita del sistema. A tale scopo, viene creato un sistema a ciclo chiuso con controllo della base e del manipolatore, che interagisce con un algoritmo di logica Dual-Filter. Grazie a questo sistema e all’impiego dei Filtri di Kalman Unscented (UKF), l'inerzia del bersaglio può essere stimata in tempo reale, senza dover interrompere il controllo della base né quello del manipolatore. Lo studio sviluppato mira ad approfondire la manovra post-cattura e a migliorare l'efficienza di questa fase. A tal fine, il sistema si avvale del software MATLAB e propone due studi: il primo ha lo scopo di comprendere i possibili vincoli della manovra di cattura attraverso un'analisi Monte Carlo che varia la configurazione iniziale del braccio; il secondo analizza il comportamento del sistema aumentando la massa e le dimensioni del bersaglio. Attraverso queste analisi, il lavoro dimostra la scarsa influenza della geometria iniziale del manipolatore e l'importanza dell’Eccitazione Persistente (PE) nella stima dei parametri di inerzia del bersaglio.The following study focuses on the post-capture phase of an In-Orbit Servicing mission of a tumbling target spacecraft. The current methods about the above mentioned operations rely on different technologies which, almost often, require a clear understanding of the target spacecraft for what concerns the inertial parameters and mass properties. Also these methods hardly consider a closed-loop model in which the coupled dynamics are assessed together with the control and parameter estimation algorithms. This work aims to perform the de-tumbling and to estimate the unknown inertia parameters of the target in order to have a deeper knowledge of the system. This is done by creating a closed-loop system with control of base and manipulator that interacts with a Dual-Filter logic algorithm. Thanks to this system and the choice of the Unscented Kalman Filters (UKF), the inertia of the target can be estimated in real-time with no need of stopping neither the base control nor the manipulator control. The developed study aims to delve deeper into the post-capture maneuver and improve the efficiency of this phase. To do so the system relies on MATLAB and it proposes two studies: the first one aims to understand the possible constrains of the capturing maneuver by using a Monte Carlo analysis that varies the initial arm configuration; the second one analyses the behavior of the system by increasing the mass and dimension of the target. With these analysis, this paper demonstrates the low influence of the manipulator initial geometry and the importance of the Persistent Excitation (PE) on the parameter estimation of the target's inertia

Risk factors and functional abnormalities associated with adult onset secondary nocturnal enuresis in women

Aims The study aims to evaluate bothersome lower urinary tract symptoms (LUTS), risk factors, and associated functional abnormalities in women reporting adult onset secondary nocturnal enuresis (SNE), to help understand factors associated with SNE. Methods 12,795 women (age \u3e18) attending a tertiary referral centre underwent a comprehensive standardized evaluation including urodynamic testing in accordance with the International Continence Society recommendations. Records of all patients reporting bedwetting while asleep were evaluated under various categories. Multiple logistic regression was used to identify statistically significant risk factors and urodynamic findings associated with SNE. Results The prevalence of SNE in women undergoing urodynamic testing for bothersome LUTS was 14.4% (1,838). High BMI (OR = 1.47, P \u3c 0.001), cigarette smoking (OR = 2, P \u3c 0.001), antidepressant usage (OR = 1.8, P \u3c 0.001), neurological conditions (OR = 2.12, P \u3c 0.001), and previous hysterectomy (OR = 1.19, P = 0.03) were significantly associated with SNE. Women with SNE significantly complained of overactive bladder (OAB) symptoms (OR = 1.65, P \u3c 0.001) and slightly higher mean nocturia episodes (OR = 1.38, P \u3c 0.0001). Low maximum urethral closure pressure (MUCP) (OR = 1.34, P \u3c 0.0001) and detrusor overactivity incontinence (DOI) (OR = 1.75, P \u3c 0.0001) were significantly associated with SNE. There was no significant association with the symptom of stress urinary incontinence (P = 0.264), urodynamic stress incontinence (P = 0.454) or detrusor overactivity (P = 0.231). Conclusion Women with adult SNE usually present with OAB symptoms. SNE is associated with high BMI, cigarette smoking, antidepressant use, and neurological conditions. DOI and a low MUCP are possible pathophysiological mechanisms in SNE. Neurourol. Urodynam. 36:188–191, 2017. © 2015 Wiley Periodicals, Inc

Influence of Age, Computer Self-Efficacy, and Educational Level On Computer Training Outcome

It is well known that throughout the 1980s and 1990s, with the growth of computer use in the workplace, older workers had greater difficulties than younger workers in learning new computer skills. Not only were older workers having more difficulties in acquiring new computer skills, but research revealed that their self-efficacy beliefs were also lower, having an adverse effect on their ability to learn and develop new skills. Also, there have been some conflicting results with regards to the mediating effects or influence that educational level has on the acquisition of skills. With a large baby-boom population in Canada, and despite some reaching retirement age, many older workers are choosing to remain in the workforce for various reasons. Since most jobs today require computer skills, it is important to investigate whether older workers are still having the same difficulties, since this may have important implications for organizations. This study proposes five hypotheses to examine how age, computer self-efficacy, and educational level influence computer training outcome. Ninety-two participants, aged 18 to 66 (M = 37.6, SD = 12.7), took part in a two-hour computer training session. Demographic data were collected, followed by measures of pre-training computer self-efficacy and pretest of computer skills. Participants received computer skills instruction, and completed posttest and post-training computer self-efficacy measures. Findings revealed that age negatively influenced computer training outcome, but no correlation was found between age and pre-training computer self-efficacy (and this remained consistent with the post-training self-efficacy measure). An ANCOVA indicated a significant effect of pre-training computer self-efficacy on computer training outcome. While age had a negative effect on training outcome, the absence of a relationship between age and pre-training computer self-efficacy ruled out the possibilities of mediation. Similarly, the absence of a relationship between age and educational level and between educational level and computer training outcome, ruled out the possibility of mediation. Post-training self-efficacy predicted both pretest and posttest results, but age had a significant negative weight, indicating that after accounting for post-training computer self-efficacy, older participants were expected to have lower posttest scores. Results are discussed in terms of implications, limitations, and future research

Essays in International and Urban Economics

Chapter 1, “The Impact of Trade Shocks on Local Labor Markets” estimates the effects of increased trade with China on Brazilian local labor markets using longitudinal individual data on the universe of Brazilian formal sector workers. First, I use reduced-form estimation strategies commonly found in the literature to compare my results to previous findings. I show that my results at the regional level mirror those found in prior studies based on cross-sectional data. I argue that these estimates are potentially biased as they do not take into account the flows of factors and goods between regions. I complement the reduced-form approach with a structural analysis based on the model by Caliendo et al. (2015) in order to endogenize such flows and to study welfare effects. I find that in the absence of the Chinese shock the Brazilian Commodities sector would have shrunk while Manufacturing and Services would have expanded. Relative to this baseline, the employment effect of increased trade with China at the national level was a slower reduction in the share of the Commodities sector and a slower growth in the Manufacturing subsectors that were relatively more exposed to Chinese import competition. My analysis suggests that while the average Brazilian worker benefitted from this shock, the welfare effects were very heterogeneous across sectors and across locations. I find that this heterogeneity is vastly underestimated if instead of using data at the level of metropolitan areas I use data aggregated by States and I explain why the choice of spatial units affects these results. Chapter 2, “Agglomeration: A Long-Run Panel Data Approach” studies the sources of agglomeration economies in cities. We begin by incorporating within and cross-industry spillovers into a dynamic spatial equilibrium model in order to obtain a panel data estimating equation. This gives us a framework for measuring a rich set of agglomeration forces while controlling for a variety of potentially confounding effects. We apply this estimation strategy to detailed new data describing the industry composition of 31 English cities from 1851-1911. Our results show that industries grew more rapidly in cities where they had more local suppliers or other occupationally-similar industries. We find no evidence of dynamic within-industry effects, i.e., industries generally did not grow more rapidly in cities in which they were already large. Once we control for these agglomeration forces, we find evidence of strong dynamic congestion forces related to city size. We also show how to construct estimates of the combined strength of the many agglomeration forces in our model. These results suggest a lower bound estimate of the strength of agglomeration forces equivalent to a city-size divergence rate of 1.6-2.3% per decade. Chapter 3, “Gravity estimation with unobserved bilateral flow data” adapts the methodology by Miscio & Soares (2016) to predict domestic trade flows by sector between Brazilian metropolitan areas. This methodology, initially developed to infer commuting flows from aggregate data on population by place of residence and by place of work, relies on moment conditions derived from a general gravity equation and it is consistent with a large class of trade models. I show that it can also be applied to infer domestic trade flows by sector. Before using the methodology on Brazilian data, where we only observe flows between States, I test it on US data from the Commodity Flow Survey, where we observe both flows between States and between finer spatial units similar to metropolitan areas. I argue that the predicted bilateral flows obtained from this methodology are highly correlated with actual flows. Alternative approaches found in the recent literature differ from the one presented here in that they require stronger assumptions and deliver weaker results. In particular, the other approaches only describe aggregate flows (i.e. summing across all sectors) and cannot be used to predict sectoral flows

Altered multisensory temporal integration in obesity

Eating is a multisensory behavior. The act of placing food in the mouth provides us with a variety of sensory information, including gustatory, olfactory, somatosensory, visual, and auditory. Evidence suggests altered eating behavior in obesity. Nonetheless, multisensory integration in obesity has been scantily investigated so far. Starting from this gap in the literature, we seek to provide the first comprehensive investigation of multisensory integration in obesity. Twenty male obese participants and twenty male healthy-weight participants took part in the study aimed at describing the multisensory temporal binding window (TBW). The TBW is defined as the range of stimulus onset asynchrony in which multiple sensory inputs have a high probability of being integrated. To investigate possible multisensory temporal processing deficits in obesity, we investigated performance in two multisensory audiovisual temporal tasks, namely simultaneity judgment and temporal order judgment. Results showed a wider TBW in obese participants as compared to healthy-weight controls. This holds true for both the simultaneity judgment and the temporal order judgment tasks. An explanatory hypothesis would regard the effect of metabolic alterations and low-grade inflammatory state, clinically observed in obesity, on the temporal organization of brain ongoing activity, which one of the neural mechanisms enabling multisensory integration

Is There a Gender Difference in the Response to onabotulinumtoxinA in Chronic Migraine? Insights from a Real-Life European Multicenter Study on 2879 Patients

Migranya crònica; Diferència de gènere; OnabotulinumtoxinAMigraña crónica; Diferencia de género, OnabotulinumtoxinAChronic migraine; Gender difference; OnabotulinumtoxinAIntroduction Migraine is mostly a female disorder because of its lower prevalence in men. Less than 20% of patients included in the available studies on migraine treatments are men; hence, the evidence on migraine treatments might not apply to men. The aims of the present study were to provide reliable information on the effectiveness of onabotulinumtoxinA (BT-A) for chronic migraine in men and to compare clinical benefits between men and women. Methods We performed a pooled patient-level gender-specific analysis of real-life data on BT-A for chronic migraine of patients followed-up to 9 months. We reported the 50% responder rates during each BT-A cycle, defined as percentage of reduction in monthly headache days (MHDs) compared to baseline, along with 75% and 30% responder rates. We also reported the mean decrease in MHDs and in days of acute medication use (DAMs) during each BT-A cycle as compared to baseline. We also evaluated the reasons for stopping the treatment within the third cycle. Results We included an overall cohort of 2879 patients, 522 of whom (18.1%) were men. In men, 50% responder rates were 27.7% during the first BT-A cycle, 29.2% during the second, and 35.6% during the third cycle; in women, the corresponding rates were 26.6%, 33.5%, and 41.0%. In the overall cohort, responder rates did not differ between men and women during the first two cycles; during the third cycle, the distribution was different (P < 0.001) mostly because of higher rates of treatment stopping and non-responders in men. In the propensity score matched cohort, the trend was maintained but lost its statistical significance. Both men and women had a significant decrease in MHDs and in DAMs with BT-A treatment (P < 0.001). There were no gender differences in those changes with the only exception of MHD decrease which, during the third cycle, was lower in men than in women (7.4 vs 8.2 days, P = 0.016 in the overall cohort and 9.1 vs 12.5 days, P = 0.009 in the propensity score matched cohort). At the end of follow-up, 152 men and 485 women stopped BT-A treatment (29.1% vs 20.6%; P < 0.001). The relative proportion of patients stopping treatment because of inadequate response (less than 30% decrease in MHDs from baseline) was higher in men than in women (42.8% vs 39.6%), while the proportion of patients stopping because of adverse events was higher in women than in men (5.6% vs 0%; P = 0.031). Conclusions Our pooled analysis suggests that the response to BT-A is significant in both men and women with a small gender difference in favor of women. Men tended to stop the treatment more frequently than women. We emphasize the need for more gender-specific data on migraine treatments from randomized controlled trials and observational studies.No funding or sponsorship was received for this study or publication of this article