Digital Repositories and the Semantic Web: Semantic Search and Navigation for DSpace

4th International Conference on Open RepositoriesThis presentation was part of the session : DSpace User Group PresentationsDate: 2009-05-21 08:30 AM – 10:00 AMIn many digital repository implementations, resources are often described against some flavor of metadata schema, popularly the Dublin Core Element Set (DCMES), as is the case with the DSpace system. However, such an approach cannot capture richer semantic relations that exist or may be implied, in the sense of a Semantic Web ontology. Therefore we first suggest a method in order to semantically intensify the underlying data model and develop an automatic translation of the flatly organized metadata information to this new ontology. Then we propose an implementation that provides for inference-based knowledge discovery, retrieval and navigation on top of digital repositories, based on this ontology. We apply this technique to real information stored in the University of Patras Institutional Repository that is based on DSpace, and confirm that more powerful, inference-based queries can indeed be performed

The determinants of loan loss provisions:an analysis of the Greek banking systemin light of the sovereign debt crisis

We utilize a new set of macroeconomic and regulatory data to analyze the evolution of loan loss provisioning practices in the Greek banking system over the period 2005-2015. We explore the determinants of the aggregate loan loss reserves to total loans ratio, which reflects the accumulation of provisions net of write-offs, and constitutes an important metric of the credit quality of loan portfolios. Our results suggest that domestic credit institutions respond relatively quickly to macroeconomic shocks, though the latter’s effects on the provisioning behavior of the domestic banking system show significant persistence. Furthermore, the impact of macroeconomic shocks on the loan loss reserves ratio has become stronger (both in terms of magnitude and statistical significance) following the outbreak of the Greek sovereign debt crisis. From a macro policy perspective, this result indicates that a sustainable stabilization of macroeconomic conditions is a key precondition for safeguarding domestic financial stability. For a regulatory standpoint, it suggests that the possibility of macroeconomic regime-related effects on banks’ provisioning policies should be taken into account when macro prudential stress tests of the banking system are designed and implemented

Explaining non-performing loans in Greece: a comparative study on the effects of recession and banking practices

Using a new dataset of macroeconomic and banking-related variables we attempt to explain the evolution of “bad” loans in Greece over the period 2005-2015. Our findings suggest that the primary cause of the sharp increase in non-performing loans (NPLs) following the outbreak of the sovereign debt crisis can be mainly attributed to the unprecedented contraction of domestic economic activity and the subsequent rise in unemployment. Furthermore, our results offer no empirical evidence in support of a range of examined hypotheses assuming overly aggressive lending practices by major Greek credit institutions or any systematic efforts to boost current earnings by extending credit to lower credit quality clients. We find that the transmission of macroeconomic shocks to NPLs takes place relatively fast, with the estimated magnitude of the respective responses being broadly comparable with that documented in some earlier studies for other euro area periphery economies. Overall, our results support a swift implementation of reforms agreed with official lenders in the context of the new (3rd) bailout programme. These envisage the modernization the county’s private sector insolvency framework and the creation of a more efficient model for the management of NPLs. A vigorous implementation of these reforms is key for allowing a resumption of positive credit creation, by freeing up valuable resources that are currently trapped in unproductive sectors of the domestic economy. This, in turn, would facilitate a speedier return to positive economic growth and a gradual reduction in unemployment

Angiographic estimation of atherosclerotic disease burden in a coronary artery fed by collaterals: a potential pitfall in decision for revascularization

Despite the remarkable advances in revascularization strategies made during the last decade, a significant proportion of patients are excluded from either percutaneous coronary intervention or coronary artery bypass grafting because of unsuitable coronary anatomy. Diffuse severe coronary artery disease, small vessel caliber, chronic total occlusions, or extremely calcified vessels are frequent reasons for deferring revascularization with either percutaneous coronary intervention or coronary artery bypass grafting. We present a case concerning a middle-aged asymptomatic patient who was treated successfully with percutaneous coronary intervention due to a chronic total occlusion lesion of the left anterior descending artery. Coronary angiography is an inadequate method for the estimation of the burden of atherosclerotic disease in an artery fed by collaterals. Assessment of any residual antegrade flow, and ipsilateral and contralateral collateral filling of the segments distal to the occlusion with invasive or noninvasive techniques, could affect the appropriate decision-making by physicians

Treatment of alopecia totalis/universalis/focalis with vitamin D and analogs: Three case reports and a literature review

BACKGROUND: Alopecia areata (AA) is an inflammatory disease with autoimmune, environmental, and inherited components directed at the hair follicle, either limited to patchy hair loss over the scalp (Focalis, AF), total loss of scalp hair (Totalis, AT), or total loss of both scalp and body hair (Universalis, AU). Despite multiple treatment modalities, no therapy exists. Vitamin D deficiency in patients with AA/AT/AF influences disease severity and duration, inversely correlating with inflammation histologically. CASE SUMMARY: Three girls presented with AT (P1), AU (P2), and AF (P3) at the ages of 1, 5, and 5 years, respectively. For P1-P2, all available treatments implemented for 2 years had failed. We started an initial 6-mo repletion with oral cholecalciferol 2000/4000 IU/d, with no apparent effect. Then we attempted immunomodulation using oral calcitriol and its analog paricalcitol. On calcitriol, 0.5 mcg/d P1 regrew hair within 6 mo. After 4 years, a relapse with loss of eyebrow hair was resolved after doubling the calcitriol dose to 0.5 mcg × 2/d; the results have been maintained for 6 years to date. On calcitriol, 0.25 mcg × 3/d P2 led to the development of asymptomatic hypercalcemia-hypercalciuria, which was immediately resolved by switching to paricalcitol 2 mcg × 3/d; mild tolerable hypercalciuria was maintained. Hair regrowth was observed at 6 mo, stabilizing only as fur at 12 mo. AF in P3 was resolved completely within 3 mo on a daily high dose (8000 IU) of cholecalciferol. CONCLUSION: Vitamin D may have immunomodulating therapeutic impact on AT/AU/AF, which needs to be explored with further pilot clinical trials

Isolated chronic mitral regurgitation with preserved systolic left ventricular function and severe pulmonary hypertension

AbstractPulmonary hypertension in chronic mitral valve disease has been related most commonly to left ventricular dysfunction or mitral stenosis; its association with chronic, isolated mitral regurgitation and preserved left ventricular systolic function is unclear. In 41 catheterized patients with chronic mitral regurgitation (known history of mitral regurgitation for >18 months) and preserved left ventricular systolic function (ejection fraction >0.55), historic, electrocardiographic, echocardiographic and hemodynamic variables were analyzed. Ten patients (Group 1) had normal pulmonary artery systolic pressure (>30 mm Hg), whereas 31 patients had pulmonary hypertension. Pulmonary artery systolic pressure was mildly increased (30 to 49 mm Hg) in 13 patients (Group II) and was >50 mm Hg in 18 patients (Group III).Univariate analysis showed the more frequent occurrence of male gender and ruptured chordae tendineae in the groups with pulmonary hypertension. Mean pulmonary capillary wedge pressure, size of the V wave in pulmonary capillary wedge pressure and pulmonary arteriole resistance were higher, whereas cardiac index was lower in the hypertension groups. Multivariate stepwise analysis revealed higher mean pulmonary capillary wedge pressure and pulmonary arteriole resistance as the only variables independently differing among groups.In conclusion, pulmonary hypertension occurs frequently (76% of cases) in patients with chronic, isolated mitral regurgitation with preserved left ventricular systolic function. In these patients, a severe increase in pulmonary capillary wedge pressure is associated with elevation in pulmonary artery resistance, a finding similar to that in mitral stenosis

Maternal pomegranate juice intake and brain structure and function in infants with intrauterine growth restriction: A randomized controlled pilot study.

Polyphenol-rich pomegranate juice has been shown to have benefit as a neuroprotectant in animal models of neonatal hypoxic-ischemia. No published studies have investigated maternal polyphenol administration as a potential neuroprotectant in at-risk newborns, such as those with intrauterine growth restriction (IUGR). This was a randomized, placebo-controlled, double-blind pilot study to investigate the impact of maternal pomegranate juice intake in pregnancies with IUGR, on newborn brain structure and function at term-equivalent age (TEA). Mothers with IUGR at 24-34 weeks\u27 gestation were recruited from Barnes-Jewish Hospital obstetrical clinic. Consented mothers were randomized to treatment (8 oz. pomegranate juice) or placebo (8 oz. polyphenol-free juice) and continued to take juice daily from enrollment until delivery (mean 20.1 and 27.1 days, respectively). Infants underwent brain MRI at TEA (36-41 weeks\u27 gestation). Brain measures were compared between groups including: brain injury score, brain metrics, brain volumes, diffusion tensor imaging and resting state functional connectivity. Statistical analyses were undertaken as modified intention-to-treat (including randomized participants who received their allocated intervention and whose infants received brain MRI) and per-protocol (including participants who strictly adhered to the protocol, based on metabolite status). Seventy-seven mothers were randomized to treatment (n = 40) or placebo (n = 37). Of these, 28 and 27 infants, respectively, underwent term-equivalent MRI. There were no group differences in brain injury, metrics or volumes. However, treatment subjects displayed reduced diffusivity within the anterior and posterior limbs of the internal capsule compared with placebo. Resting state functional connectivity demonstrated increased correlation and covariance within several networks in treatment subjects, with alterations most apparent in the visual network in per-protocol analyses. Direct effects on health were not found. In conclusion, maternal pomegranate juice intake in pregnancies with known IUGR was associated with altered white matter organization and functional connectivity in the infant brain, suggesting differences in brain structure and function following in utero pomegranate juice exposure, warranting continued investigation. Clinical trial registration. NCT00788866, registered November 11, 2008, initial participant enrollment August 21, 2012

Adjunctive Antiplatelet Treatment in Primary Percutaneous Coronary Intervention

Background: Despite significant advances in the management of coronary heart disease, myocardial infarction is still associated with high mortality. Thienopyridines and glycoprotein IIb/IIIa inhibitors have been used extensively in the management of ST segment elevation myocardial infarction. Objective: This article discusses the evidence from clinical trials and registries concerning the benefits of thienopyridines, reviews the results of published multicenter, randomized controlled trials of the efficacy and safety of platelet GPIIb/IIIa inhibitors in patients with acute myocardial infarction undergoing primary percutaneous coronary intervention (PCI) and presents the recent guidelines.Methods: Data for this review were identified by broad searches of MEDLINE, Current Contents and references from relevant articles (1980-2011); numerous articles were identified through searches of the extensive files of the authors and selected based on their importance, oppurtunity for further reading and up to date information. Search terms included thienopyridines, platelet aggregation inhibitors, percutaneous coronary intervention, antiplatelet therapy, ST elevation myocardial infarction (STEMI), primary percutaneous coronary intervention. Only English language papers were reviewed. No restrictions were set on the type of papers.Results: Clopidogrel is the most commonly used thienopyridine in patients undergoing primary PCI. Recently new inhibitors of P2Y12 receptors, like prasugrel and ticagrelor, have become available, which have a more potent and rapid onset of action, with similar safety profile, which is specifically targeted to the subgroup of primary PCI. On the other hand, the platelet glycoprotein IIb/IIIa inhibitors have aided and abetted medical management of acute coronary syndromes and proved an important adjunctive therapy in percutaneous coronary interventions. Platelet glycoprotein IIb/IIIa inhibitors, although not recommended for routine therapy, have an important role at the time of primary PCI, particularly in high-risk subgroups, like the diabetics and those with a heavy thrombotic burden.Conclusion: Clopidogrel remains the most used thienopyridine together with aspirin in patients undergoing primary PCI but there are currently available new inhibitors of P2Y12 receptors, like prasugrel and ticagrelor, which have a more potent and rapid onset of action, with similar safety profile. Glycoprotein IIb/IIIa antagonists, although not recommended for routine therapy, can be of use at the time of primary PCI, particularly in high-risk subgroups

Predictors of outcome in idiopathic rapidly progressive glomerulonephritis (IRPGN)

BACKGROUND: Small vessel vasculitides are known to follow a devastating course towards end-stage renal disease, unless treated with immunosuppressive regiments. We investigated the value of clinical, histological and immunohistochemical parameters as predictors of outcome at diagnosis in patients with pauci immune necrotizing glomerulonephritis. METHODS: In 34 patients the percentage and evolution stage of crescents, the presence of glomerular necrosis, the degree or severity of arteriosclerosis, as well as the extent of tubulointerstitial infiltration, interstial fibrosis and tubular atrophy were assessed. Monoclonal antibodies were used to identify infiltrating macrophages, α-SMA(+) and PCNA(+) cells, the expression of integrins α3β1 and LFA-1β, the adhesion molecule ICAM-1, the growth factor TGF-β1 and the terminal complement component C5b-9. RESULTS: 24 pts (70.6%) showed a complete or partial response to the treatment. The follow-up period was 20 ± 22 months. At multivariate analysis, serum CRP (p = 0.024), the intensity of tubular expression of C5b-9 (p < 0.0001) as well as the extent of glomerular and tubular expression of α3β1 integrin (p = 0.001 and 0.008 respectively) independently predicted the response to treatment. The response rate was better in ANCA(+) pts (p = 0.008). The extent of interstitial infiltrate (p < 0.0001), the severity of tubulointerstitial fibrosis (p < 0.0001) and the severity of tubular TGF-β1 expression (p < 0.0001) were independent predictors of long term outcome of renal function. CONCLUSION: Patients with ANCA-associated renal vasculitis seem to respond better to the treatment. Acute phase reactants, such as CRP, implying a more intense parenchymal inflammatory reaction, as well as the intensity of the de novo expression of C5b-9 and the glomerular and tubular expression of α3β1 integrin predict the response to therapy. The severity of TIN lesions and of the tubulo-interstitial TGF-β1 and C5b-9 expression predict an unfavourable outcome