Center for Research and Technology

Vólos, Greece

Center for Research and Technology

Vólos, Greece
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Albakour M.-D.,University of Essex | Kruschwitz U.,University of Essex | Nanas N.,Center for Research and Technology | Song D.,Robert Gordon University | And 2 more authors.
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2011

Search engines have become much more interactive in recent years which has triggered a lot of work in automatically acquiring knowledge structures that can assist a user in navigating through a document collection. Query log analysis has emerged as one of the most promising research areas to automatically derive such structures. We explore a biologically inspired model based on ant colony optimisation applied to query logs as an adaptive learning process that addresses the problem of deriving query suggestions. A user interaction with the search engine is treated as an individual ant's journey and over time the collective journeys of all ants result in strengthening more popular paths which leads to a corresponding term association graph that is used to provide query modification suggestions. This association graph is being updated in a continuous learning cycle. In this paper we use a novel automatic evaluation framework based on actual query logs to explore the effect of different parameters in the ant colony optimisation algorithm on the performance of the resulting adaptive query suggestion model. We also use the framework to compare the ant colony approach against a state-of-the-art baseline. The experiments were conducted with query logs collected on a university search engine over a period of several years. © 2011 Springer-Verlag.

Kruschwitz U.,University of Essex | Albakour M.-D.,University of Essex | Niu J.,University of Essex | Leveling J.,Dublin City University | And 5 more authors.
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2011

Search applications have become very popular over the last two decades, one of the main drivers being the advent of the Web. Nevertheless, searching on the Web is very different to searching on smaller, often more structured collections such as digital libraries, local Web sites, and intranets. One way of helping the searcher locating the right information for a specific information need in such a collection is by providing well-structured domain knowledge to assist query modification and navigation. There are two main challenges which we will both address in this chapter: acquiring the domain knowledge and adapting it automatically to the specific interests of the user community. We will outline how in digital libraries a domain model can automatically be acquired using search engine query logs and how it can be continuously updated using methods resembling ant colony behaviour. © 2011 Springer-Verlag.

Gkizlis V.,University of Thessaly | Giannaki C.D.,University of Nicosia | Giannaki C.D.,University of Thessaly | Karatzaferi C.,Center for Research and Technology | And 7 more authors.
ASAIO Journal | Year: 2012

Restless legs syndrome (RLS) affects both the general population and patients with chronic renal failure. Even though it has been suggested that all forms of RLS share a common pathophysiology, not much evidence exists on how RLS of different etiology could affect aspects related to quality of life (QoL). The aim of this study was to investigate whether patients with uremic RLS (uRLS) experience lower QoL, mental health, and sleep quality, compared with their idiopathic RLS (iRLS) counterparts. Fifteen iRLS patients, 26 uRLS patients, and 15 age-matched healthy individuals participated in the study. The RLS diagnosis and severity, the depression levels, the perception of sleep, and perceived health-related QoL levels were assessed through validated questionnaires. Sleep status was not different between the two RLS groups. In contrast, the uRLS patients scored higher in RLS symptoms severity, depression, while they scored lower in QoL levels compared with iRLS patients. QoL levels were significantly lower in both RLS groups compared with healthy individuals. In conclusion, the uRLS patients experienced lower QoL levels and more severe RLS symptoms, compared with the idiopathic group, possibly leading to the observed higher depression symptoms score. Copyright © 2012 by the American Society for Artificial Internal.

Pavlidis P.,King's College London | Pavlidis P.,University College London | Romanidou O.,King's College London | Romanidou O.,Center for Research and Technology | And 16 more authors.
Clinical and Developmental Immunology | Year: 2012

Why zymogen glycoprotein 2 (GP2), the Crohn's disease (CD)-specific pancreatic autoantigen, is the major target of humoral autoimmunity in inflammatory bowel diseases (IBD) is uknown. Recent evidence demonstrates that GP2 is also present on the apical surface of microfold (M) intestinal cells. As the colon lacks GP2-rich M cells, we assumed that patients with colonic CD are seronegative for anti-GP2. Anti-GP2 antibodies were tested in 225 CDs, including 45 patients with colonic location (L2), 45 with terminal ileum (L1) and 135 with ileocolonic involvement; 225 patients with ulcerative colitis (UC) were also tested. Anti-GP2 reactivity was detected in 59 (26.2) CDs and 15 (6.7) UCs (P < 0.001). Only 5 CDs with L2 had anti-GP2 antibodies, compared to 54/180 (30.0, P = 0.0128) of the CDs with L1 and L3. Anti-GP2 antibody positive CD patients had higher ASCA titres compared to seronegative cases. Amongst the 128 CD patients with previous surgical intervention, 45 (35.0) were anti-GP2 antibody positive compared to 14/97 (14.0) without surgical (P < 0.001). Our data support the assumption that ileal inflammation is required for the development of anti-GP2 antibodies in CD, and suggest that the intestine rather than the pancreatic juice is the antigenic source required for the initiation of anti-GP2 antibodies. © 2012 Polychronis Pavlidis et al.

Chassanidis C.G.,University of Thessaly | Malizos K.N.,University of Thessaly | Malizos K.N.,Center for Research and Technology | Varitimidis S.,University of Thessaly | And 6 more authors.
Journal of Bone and Joint Surgery - Series B | Year: 2012

Periosteum is important for bone homoeostasis through the release of bone morphogenetic proteins (BMPs) and their effect on osteoprogenitor cells. Smoking has an adverse effect on fracture healing and bone regeneration. The aim of this study was to evaluate the effect of smoking on the expression of the BMPs of human periosteum. Real-time polymerase chain reaction was performed for BMP-2,-4,-6,-7 gene expression in periosteal samples obtained from 45 fractured bones (19 smokers, 26 non-smokers) and 60 non-fractured bones (21 smokers, 39 non-smokers). A hierarchical model of BMP gene expression (BMP-2 > BMP-6 > BMP-4 > BMP-7) was demonstrated in all samples. When smokers and non-smokers were compared, a remarkable reduction in the gene expression of BMP-2, -4 and -6 was noticed in smokers. The comparison of fracture and non-fracture groups demonstrated a higher gene expression of BMP-2, -4 and -7 in the non-fracture samples. Within the subgroups (fracture and non-fracture), BMP gene expression in smokers was either lower but without statistical significance in the majority of BMPs, or similar to that in non-smokers with regard to BMP-4 in fracture and BMP-7 in non-fracture samples. In smokers, BMP gene expression of human periosteum was reduced, demonstrating the effect of smoking at the molecular level by reduction of mRNA transcription of periosteal BMPs. Among the BMPs studied, BMP-2 gene expression was significantly higher, highlighting its role in bone homoeostasis. ©2012 British Editorial Society of Bone and Joint Surgery.

Samara S.,University of Thessaly | Dailiana Z.,University of Thessaly | Chassanidis C.,University of Thessaly | Koromila T.,National and Kapodistrian University of Athens | And 4 more authors.
Experimental and Molecular Pathology | Year: 2014

Introduction: Femoral head avascular necrosis (AVN) is a recalcitrant disease of the hip that leads to joint destruction. Osteoprotegerin (OPG), Receptor Activator of Nuclear Factor kappa-B (RANK) and RANK ligand (RANKL) regulate the balance between osteoclasts-osteoblasts. The expression of these genes affects the maturation and function of osteoblasts-osteoclasts and bone remodeling. In this study, we investigated the molecular pathways leading to AVN by studying the expression profile of OPG, RANK and RANKL genes. Material and methods: Quantitative Real Time-PCR was performed for evaluation of OPG, RANK and RANKL expression. Analysis was based on parallel evaluation of mRNA and protein levels in normal/necrotic sites of 42 osteonecrotic femoral heads (FHs). OPG and RANKL protein levels were estimated by western blotting. Results: The OPG mRNA levels were higher (insignificantly) in the necrotic than the normal site (p. >. 0.05). Although the expression of RANK and RANKL was significantly lower than OPG in both sites, RANK and RANKL mRNA levels were higher in the necrotic part than the normal (p. <. 0.05). Protein levels of OPG and RANKL showed no remarkable divergence. Conclusions: Our results indicate that differential expression mechanisms for OPG, RANK and RANKL that could play an important role in the progress of bone remodeling in the necrotic area, disturbing bone homeostasis. This finding may have an effect on the resulting bone destruction and the subsequent collapse of the hip joint. © 2013.

Lawson L.G.,Copenhagen University | Pedersen S.M.,Copenhagen University | Sorensen C.G.,University of Aarhus | Pesonen L.,Mtt Agrifood Research Finland | And 8 more authors.
Computers and Electronics in Agriculture | Year: 2011

The aim of this paper is to present the descriptive results of the survey responses that explore the perception of advanced information systems among four European countries: i.e. Denmark, Finland, Germany and Greece. The study evaluates the potential time savings associated with office tasks for information management and the likely adoption of advanced farming systems and precision farming practices. The survey results suggest that there are differences in weekly hours allocated to office tasks and its distribution across countries. However, there seems to be a potential benefit for introducing labour saving farm information management systems in relation to budgeting procedures, field planning and paperwork to deal with subsidy applications and public authorities. More than 40% of the respondent farms from Germany, Denmark and Finland seem to be unsure about usefulness of computers in dealing with official institutions and consumers. The extent to which the finding is linked to the budgeted time allocated to office tasks is worth pursuing. © 2011 Elsevier B.V.

Giannaki C.D.,University General Hospital of Larissa | Giannaki C.D.,Center for Research and Technology | Giannaki C.D.,University of Nicosia | Zigoulis P.,University of Thessaly | And 12 more authors.
Journal of Clinical Sleep Medicine | Year: 2013

Study Objectives: In hemodialysis (HD) patients, restless legs syndrome (RLS) and periodic limb movements in sleep (PLMS) constitute common sleep disorders. Recent findings indicate a role for PLMS as a risk factor in the development of new or the aggravation of existing cardiovascular disease. The aim of the current study was to investigate the association of PLMS with indices of cardiac morphology and function in HD patients with RLS as a potential pathway by which PLMS could alter cardiovascular risk. Methods: Based on PLMS diagnosis by an overnight polysomnographic evaluation, 19 stable HD-RLS patients were divided into the PLMS group (n = 10) and the non-PLMS group (n = 9). During the overnight assessment, nocturnal blood pressure (BP) indices were also assessed. Left ventricular (LV) dimensions were examined by M-mode echocardiography, whereas LV diastolic function was evaluated by conventional Doppler and tissue Doppler imaging the following day. Results: LV internal diameter in diastole was significantly increased in the PLMS group (4.96 ± 0.61 vs 4.19 ± 0.48 cm, p = 0.007), leading to a significantly increase in LV mass (202 ± 52 vs 150 ± 37 g, p = 0.026). In contrast, no between group differences were observed in diastolic function indices (p > 0.05). Conclusions: These are the first data to associate severe PLMS with further LV structure abnormalities in HD patients with RLS.

Kim S.H.,Indiana University Bloomington | Kim S.H.,University of Missouri | Qi D.,Indiana University Bloomington | Qi D.,Center for Research and Technology | And 3 more authors.
Science | Year: 2016

Maintaining high crop yields in an environmentally sustainable manner requires the development of disease-resistant crop varieties. We describe a method to engineer disease resistance in plants by means of an endogenous disease resistance gene from Arabidopsis thaliana named RPS5, which encodes a nucleotide-binding leucine-rich repeat (NLR) protein. RPS5 is normally activated when a second host protein, PBS1, is cleaved by the pathogen-secreted protease AvrPphB. We show that the AvrPphB cleavage site within PBS1 can be substituted with cleavage sites for other pathogen proteases, which then enables RPS5 to be activated by these proteases, thereby conferring resistance to new pathogens. This "decoy" approach may be applicable to other NLR proteins and should enable engineering of resistance in plants to diseases for which we currently lack robust genetic resistance. © 2016, American Association for the Advancement of Science. All rights reserved.

Nash E.,University of Rostock | Wiebensohn J.,University of Rostock | Nikkila R.,Aalto University | Vatsanidou A.,University of Thessaly | And 4 more authors.
Computers and Electronics in Agriculture | Year: 2011

Production standards in the form of legal regulations or quality assurance labels are playing an increasingly important role in farming. Each farm must therefore gather information on all standards which apply, which may vary from field-to-field, and ensure that they are respected during operations. This information may be provided on paper or as electronic documents, by the standards publishers or by advisors. Together with the need to document compliance, the need to collect and process the requirements is becoming increasingly burdensome for farmers.In this paper, two questions are addressed: whether an automation of the compliance checking is possible, in order to assist the farmer by proactively warning against 'forbidden' operations, and how the definition of the production standard may be formally represented in order to clearly and unambiguously inform the farmer as to what is required. This formal representation also forms one of the prerequisites for any automated assessment.As an initial step, a general model of production standards was developed and applied to some common standards in European agriculture. Based on this model, separating standards into metadata and a list of individual rules (check points), a formal representation was developed and an assessment was made as to whether an automated compliance check was feasible. © 2011 Elsevier B.V.

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