Gastrointestinal Disorders Georgoulis, Michael; Kechribari, Ioanna; Kontogianni, Meropi D.
Antioxidants in Health and Disease,
2015
Book Chapter
Odprti dostop
This chapter provides an overview of the role of oxidative stress in the pathogenesis of inflammation-based gastrointestinal tract diseases, namely celiac disease and inflammatory bowel diseases, as ...well as the potential role of antioxidants in their prevention and treatment. Celiac disease is associated with serious consequences on health, such as malabsorption of nutrients, osteoporosis, gastrointestinal malignancies, and the onset of other autoimmune diseases, such as diabetes mellitus, making it a serious public health problem, which needs to be treated. Among the mediators of the dysfunctional immunoregulation of the gut, oxidative stress is considered as a potential etiological and/or triggering factor for Inflammatory bowel disease (IBD). Oxidative stress is considered to contribute both to the development and the progression of IBD. Current theories on IBD pathogenesis suggest that interactions among various genetic, environmental, and immune factors lead to an uncontrolled, dysregulated immune response in the intestinal mucosa.
A crucial challenge to successful flare prediction is forecasting periods that transition between "flare-quiet" and "flare-active." Building on earlier studies in this series in which we describe the ...methodology, details, and results of flare forecasting comparison efforts, we focus here on patterns of forecast outcomes (success and failure) over multiday periods. A novel analysis is developed to evaluate forecasting success in the context of catching the first event of flare-active periods and, conversely, correctly predicting declining flare activity. We demonstrate these evaluation methods graphically and quantitatively as they provide both quick comparative evaluations and options for detailed analysis. For the testing interval 2016-2017, we determine the relative frequency distribution of two-day dichotomous forecast outcomes for three different event histories (i.e., event/event, no-event/event, and event/no-event) and use it to highlight performance differences between forecasting methods. A trend is identified across all forecasting methods that a high/low forecast probability on day 1 remains high/low on day 2, even though flaring activity is transitioning. For M-class and larger flares, we find that explicitly including persistence or prior flare history in computing forecasts helps to improve overall forecast performance. It is also found that using magnetic/modern data leads to improvement in catching the first-event/first-no-event transitions. Finally, 15% of major (i.e., M-class or above) flare days over the testing interval were effectively missed due to a lack of observations from instruments away from the Earth-Sun line.
Solar flares are extremely energetic phenomena in our solar system. Their impulsive and often drastic radiative increases, particularly at short wavelengths, bring immediate impacts that motivate ...solar physics and space weather research to understand solar flares to the point of being able to forecast them. As data and algorithms improve dramatically, questions must be asked concerning how well the forecasting performs; crucially, we must ask how to rigorously measure performance in order to critically gauge any improvements. Building upon earlier-developed methodology of Paper I (Barnes et al. 2016), international representatives of regional warning centers and research facilities assembled in 2017 at the Institute for Space-Earth Environmental Research, Nagoya University, Japan to, for the first time, directly compare the performance of operational solar flare forecasting methods. Multiple quantitative evaluation metrics are employed, with the focus and discussion on evaluation methodologies given the restrictions of operational forecasting. Numerous methods performed consistently above the "no-skill" level, although which method scored top marks is decisively a function of flare event definition and the metric used; there was no single winner. Following in this paper series, we ask why the performances differ by examining implementation details (Leka et al. 2019), and then we present a novel analysis method to evaluate temporal patterns of forecasting errors in Paper IV (Park et al. 2019). With these works, this team presents a well-defined and robust methodology for evaluating solar flare forecasting methods in both research and operational frameworks and today's performance benchmarks against which improvements and new methods may be compared.
A workshop was recently held at Nagoya University (2017 October 31-November 2), sponsored by the Center for International Collaborative Research, at the Institute for Space-Earth Environmental ...Research, Nagoya University, Japan, to quantitatively compare the performance of today's operational solar flare forecasting facilities. Building upon Paper I of this series, in Paper II we described the participating methods for this latest comparison effort, the evaluation methodology, and presented quantitative comparisons. In this paper, we focus on the behavior and performance of the methods when evaluated in the context of broad implementation differences. Acknowledging the short testing interval available and the small number of methods available, we do find that forecast performance: (1) appears to improve by including persistence or prior flare activity, region evolution, and a human "forecaster in the loop"; (2) is hurt by restricting data to disk-center observations; (3) may benefit from long-term statistics but mostly when then combined with modern data sources and statistical approaches. These trends are arguably weak and must be viewed with numerous caveats, as discussed both here and in Paper II. Following this present work, in Paper IV (Park et al. 2019) we will present a novel analysis method to evaluate temporal patterns of forecasting errors of both types (i.e., misses and false alarms). Hence, most importantly, with this series of papers, we demonstrate the techniques for facilitating comparisons in the interest of establishing performance-positive methodologies.
We introduce and make openly accessible a comprehensive, multivariate time series (MVTS) dataset extracted from solar photospheric vector magnetograms in Spaceweather HMI Active Region Patch (SHARP) ...series. Our dataset also includes a cross-checked NOAA solar flare catalog that immediately facilitates solar flare prediction efforts. We discuss methods used for data collection, cleaning and pre-processing of the solar active region and flare data, and we further describe a novel data integration and sampling methodology. Our dataset covers 4,098 MVTS data collections from active regions occurring between May 2010 and December 2018, includes 51 flare-predictive parameters, and integrates over 10,000 flare reports. Potential directions toward expansion of the time series, either "horizontally" - by adding more prediction-specific parameters, or "vertically" - by generalizing flare into integrated solar eruption prediction, are also explained. The immediate tasks enabled by the disseminated dataset include: optimization of solar flare prediction and detailed investigation for elusive flare predictors or precursors, with both operational (research-to-operations), and basic research (operations-to-research) benefits potentially following in the future.
The optimal initial graft tension during ACL reconstruction is still a matter of debate. Manual tension is commonly applied to the graft during tibial fixation. However, this has been associated with ...a greater graft failure rate than that associated with device-assisted tensioning. This study aims to compare the clinical outcomes between the application of manual tension and the use of the ConMed Linvatec SE™ Graft Tensioning System during graft fixation while performing anatomic single-bundle ACL reconstruction.
A prospective comparative study was conducted between September 2015 and May 2017. Sixty-four patients (mean age 29.3 years, range 14-45) with isolated ACL injuries (and who would be subjected to ACL reconstruction with a quadruple hamstring tendon graft) were divided into two groups. In Group A (
= 29), common tension was applied manually to both grafts. In Group B (
= 35), specific tension was applied to the grafts with the use of a tensioner device (ConMed Linvatec SE™ (Stress Equalization) Graft Tensioning System). A total of 60 N was applied to the semitendinosus, and 40 N was applied to the gracilis. Clinical outcomes were assessed at 6, 12, and 24 months.
There were no significant differences between the baseline demographic and clinical data among the patients of the two groups (all
> 0.05). The patients were followed up for a minimum of 24 months (mean ± SD). There were no significant differences in the side-to-side anterior knee laxity, the IKDC, the Lysholm Knee, and the Tegner Activity Scale scores for up to 24 months after operation. The pivot shift test was negative in all cases, and no graft failure was reported at a 2-year follow-up.
No significant differences were found with respect to postoperative anterior knee laxity, clinical outcomes, activity level, and patient satisfaction between the application of manual tension and the use of the graft-tensioning system during tibial fixation while performing anatomic single-bundle ACL reconstruction with a quadruple hamstring tendon graft. Further high-quality clinical studies are required to elucidate whether device-assisted tension is superior to manual tension.
Purpose
The purpose of this study was to test whether rotational knee kinematics during dynamic pivoting activities are predictive of subjective functional outcome (IKDC, Lysholm), objective laxity ...scores (KT max), and activity levels (Tegner) in patients after anterior cruciate ligament reconstruction (ACLR).
Methods
Thirty-one patients with single-bundle ACLR were evaluated prospectively with 3D-motion analysis during (1) descending a stairway and pivoting and (2) landing from a jump and pivoting. The side-to-side difference of tibial rotation range of motion (SSDTR) between the ACLR and the contralateral intact knee was calculated for the pivoting phase of each task. Linear regression models were applied with SSDTR, for each task predictors of the subjective IKDC score, Lysholm score, anterior tibial translation, and Tegner activity level.
Results
SSDTR for descending and landing were predictive of the IKDC subjective score (
R
2
= 0.46,
p
< 0.001 and
R
2
= 0.40,
p
< 0.001, respectively) with “medium” effect sizes and of the Lysholm score (
R
2
= 0.13,
p
< 0.05 and
R
2
= 0.09, n.s.) with “small” to “none” effect sizes. SSDTR was not predictive of anterior translation or Tegner activity level (n.s.).
Conclusions
Restoring rotational kinematics during dynamic pivoting activities after ACLR is predictive of functional outcome. The ability of the athlete after ACLR to control tibial rotation during pivoting activities may be predictive of functional outcome.
Level of evidence
Case series study. Level IV.
Here we analyze the first complete genome sequence of
Pyrococcus chitonophagus
. The archaeon was previously suggested to belong to the
Thermococcus
rather than the
Pyrococcus
genus. Whole genome ...phylogeny as well as whole proteome comparisons using all available complete genomes in
Thermococcales
clearly showed that the species belongs to the
Pyrococcus
genus.
P. chitonophagus
was originally isolated from a hydrothermal vent site and it has been described to effectively degrade chitin debris, and therefore is considered to play a major role in the sea water ecology and metabolic activity of microbial consortia within hot sea water ecosystems. Indeed, an obvious feature of the
P. chitonophagus
genome is that it carries proteins showing complementary activities for chitin degradation, i.e. endo- and exo-chitinase, diacetylchitobiose deacetylase and exo-β-
d
glucosaminidase activities. This finding supports the hypothesis that compared to other
Thermococcales
species
P. chitonophagus
is adapted to chitin degradation.
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