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This paper investigates two mapping methods for Kerkini reservoir bottom, in order to study the morphology and the evolution of deposits at the reservoir. The methods are the hydrographic and the satellite bathymetry. The hydrographic method incorporates the geodetic satellite technology with sonar system for mapping the bottom relief, while the satellite bathymetry extracts the depths using the information from the spectral bands of a satellite image. The satellite Worldview-2 was used in this study. The milestones for the Kerkini reservoir were the years 1952 and 1982, where the construction of the west dike changed the hydrological regime. After these changes, bottom surveys of the reservoir were carried out in 1962 and 1984 and charts were produced. Based on these diagrams, deposition rates are calculated and volumes are compared over the years till the recent mapping in 2014. The digital bathymetry models, obtained from the implementation of hydrography and satellite bathymetry, are compared to each other. Furthermore, the development of new methods for the determination of volume and deposition rate can contribute to the optimal management of such water systems and the creation of a sustainability index for the reservoir.

The aim of this study was to evaluate the effect of antioxidant agents and freezing methods on the ability of ram sperm to preserve its post-thaw quality characteristics. Six Chios rams were subjected to 52 weekly semen collections. Each ram was used as semen donor for freezing experiments once every 2 weeks. Equal number of good quality spermatozoa from each ejaculate (concentration ≥1 × 109 spermatozoa/ml, motility ≥70%, motility score ≥3.5) were pooled. Three equal aliquots of the pooled sample were diluted using three different fractions of a milk-based and glycerol extender (control, quercetin-enriched, α-tocopherol-enriched). Three freezing methods were applied (slow and fast freezing rate in a programmable freezer, vapors of liquid nitrogen) in every aliquot. Sperm aliquots were tested before freezing, immediately after thawing and after 3 h of incubation at 37 °C. Sperm motility (%) was evaluated microscopically. The percentage of membrane and acrosome-intact spermatozoa (IL%) as well as the percentage of membrane-intact and acrosome-reacted spermatozoa (ARL%) were determined by eosin-nigrosin stain. Furthermore, the percentage of hypo-osmotic swelling (HOS) test-positive spermatozoa was estimated. The results revealed no beneficial effect of the antioxidant treatment on the parameters of post-thaw semen (P > 0.05). However, the slow freezing rate method was more beneficial regarding motility, IL, ARL and HOS-positive spermatozoa compared to the other methods. In conclusion, the antioxidant agents used in this study failed to protect sperm against cryopreservation stress; however, the choice of the appropriate freezing method could contribute to the improvement of post-thaw ram sperm quality.

Left ventricular diastolic dysfunction (LVDD) constitutes the prominent characteristic of cirrhotic cardiomyopathy, but its relevance on the clinical course of cirrhotic patients has not been clearly defined. The aim of the study was to evaluate the relationship of LVDD with the severity and etiology of liver disease and to investigate whether it affects the outcome of cirrhotic patients. Cardiac function of 45 cirrhotics was studied by a tissue Doppler imaging echocardiography. Diagnosis of LVDD was made according to the latest guidelines of the American Society of Echocardiography. All patients were followed up for a period of 2 years. Death or liver transplantation was the endpoint of the study. LVDD was found in 17 (38 %) of 45 patients. Its presence was not found to be associated with the etiology and stage of cirrhosis, but its severity was directly correlated with the Child-Pugh score. At the end of follow-up, 14 patients had died; 9 had LVDD (9/17, 53 %) and 5 had not (5/28, 18 %). Patients who died at the beginning of observation period had a higher Child-Pugh and MELD score, higher BNP, lower albumin and more prolonged QTc. On Kaplan-Meier analysis, patients with LVDD had statistically significantly worse prognosis compared to those without (p = 0.013, log rank: 5.495). Low albumin values (p = 0.003) and presence of LVDD (p = 0.017) were independent predictive factors of mortality. LVDD is a common complication of cirrhosis. As its development seems to be related to a worse prognosis, patients with LVDD must be under a strict follow-up.

Background Most NSAIDs are thought to be able to cause hepatic injury and acute liver failure (ALF), but the event rates of those leading to transplantation (ALFT) remain uncertain. Objectives The aim of the study was to estimate population event rates for NSAID-associated ALFT Methods This was a case-population study of ALFT in 57 eligible liver transplant centres in seven countries (France, Greece, Ireland, Italy, The Netherlands, Portugal and the UK). Cases were all adults registered from 2005 to 2007 for a liver transplant following ALFT without identified clinical aetiology, exposed to an NSAID or paracetamol (acetaminophen) within 30 days before the onset of clinical symptoms. NSAID and paracetamol population exposures were assessed using national sales data from Intercontinental Marketing Services (IMS). Risk was estimated as the rate of ALFT per million treatment-years (MTY). Results In the 52 participating centres, 9479 patients were registered for transplantation, with 600 for ALFT, 301 of whom, without clinical aetiology, had been exposed to a drug within 30 days. Of these 301 patients, 40 had been exposed to an NSAID and 192 to paracetamol (81 of whom were without overdose). Event rates per MTY were 1.59 (95 % CI 1.1–2.2) for all NSAIDs pooled, 2.3 (95 % CI 1.2–3.9) for ibuprofen, 1.9 (95 % CI 0.8–3.7) for nimesulide, 1.6 (95 % CI 0.6–3.4) for diclofenac and 1.6 (95 % CI 0.3–4.5) for ketoprofen. For paracetamol, the event rate was 3.3 per MTY (95 % CI 2.6–4.1) without overdoses and 7.8 (95 % CI 6.8–9.0) including overdoses. Conclusions ALF leading to registration for transplantation after exposure to an NSAID was rare, with no major difference between NSAID. Non-overdose paracetamol-exposed liver failure was twice more common than NSAID-exposed liver failure. Electronic supplementary material The online version of this article (doi:10.1007/s40264-012-0013-7) contains supplementary material, which is available to authorized users.

Background Laparoscopic cholecystectomy is the gold standard treatment of gallbladder disease. Post-cholecystectomy syndrome is a severe postoperative complication which can be caused by multiple mechanisms and can present with multiple disorders. The wide use of laparoscopy induces the need to understand more clearly the presentation and pathophysiology of this syndrome. Post-cholecystectomy Mirizzi syndrome is one form of this syndrome and, according to literature, this is the first report that clearly describes it. Case presentation We describe the case of a 62-year-old Greek woman who underwent laparoscopic cholecystectomy because of gallstone disease. A few days after surgery, post-cholecystectomy syndrome gradually developed with mild bilirubin increase in association with epigastric pain, nausea, and vomiting. After performing ultrasound, magnetic resonance cholangiopancreatography, and endoscopic retrograde cholangiopancreatography, we conducted a second laparoscopic surgery to manage the obstruction, which was converted to open surgery because of the remaining inflammation from the post-endoscopic retrograde cholangiopancreatography acute pancreatitis. Four polymeric laparoscopic clips were removed because they were identified as the cause of her post-cholecystectomy syndrome. She had a quick recovery without further complications. Conclusions Postoperative Mirizzi syndrome induced by the migration of polymer laparoscopic clips is a rare (only one case referring to polymeric clips has been published in the literature) but a well-identified complication of laparoscopic cholecystectomy which can confuse the diagnostic and therapeutic field requiring simultaneous immediate management.

Barrett’s esophagus (BE) is a major complication of gastroesophageal reflux disease due to its neoplastic potential. The length of the metaplastic epithelium has been associated with cancer risk. Angiogenesis, inflammation, and increased cell proliferation are early events in the malignant sequence. Vascular endothelial growth factor (VEGF), cyclooxygenase-2 (COX-2) and Ki-67 are indirect markers of these complex mechanisms. To examine the expression of VEGF, COX-2 and Ki-67 in BE and investigate whether there is an association to Barrett’s length. Immunohistochemistry for VEGF, COX-2, and Ki-67 was performed in well-characterized Barrett’s samples, evaluated using a qualitative scale and compared between long (LSBE) and short (SSBE) segments. The study population consisted of 98 patients (78 men). LSBE and SSBE was diagnosed in 33 (33.7%) and 65 (66.3%) cases, respectively. VEGF was expressed in vascular endothelium of all Barrett’s specimens. COX-2 and Ki-67 expression in metaplastic epithelia was strong in 81.6 and 61.2% of the samples, respectively. Ki-67 expression was significantly stronger in LSBE (p = 0.035), whereas VEGF expression was significantly increased in SSBE (p = 0.031). COX-2 expression was not associated with Barrett’s length. VEGF, COX-2, and Ki-67 were overexpressed in the majority of Barrett’s samples. The length was inversely associated with VEGF expression and directly associated with Ki-67 expression.

Δημοσίευση σε επιστημονικό περιοδικό Summarization: In this paper we design and study the performance of a Medium Access Control (MAC) scheme for the multiplexing and the integrated delivery of voice, mobile messaging, IP, gaming and H.264 videoconference traffic over a high-speed cellular TDMA channel with errors and capture. To the best of our knowledge, this is one of the first papers in the literature investigating the integration of actual H.264 video traces and gaming traffic with other types of traffic over wireless networks. Our results show that the proposed scheme achieves high throughput results while preserving the strict Quality of Service (QoS) requirements of each traffic type, and outperforms two efficient schemes previously proposed in the literature. Presented on: Wireless Networks

Statistical downscaling techniques have been developed for the generation of maximum and minimum temperatures in Greece. This research focuses on the four conventional seasons, and three downscaling approaches, Multiple Linear Regression using a circulation type approach (MLRct), Canonical Correlation Analysis (CCA) and Artificial Neural Networks (ANNs), are employed and compared to assess their performance skills. Models were developed individually for each variable (Tmax, Tmin), station and season. The accuracy of downscaled values has been quantified in terms of a number of performance criteria, such as differences of the mean and standard deviation ratios between observed and modelled data, the correlation coefficients of the two sets, and also the RMSEs of the downscaled values relative to the observed. All methods revealed that during the cool season Tmax tends to be better reproduced, whereas Tmin is overestimated, particularly over western Greece, which is characterised by higher orography. With respect to the warm season, the simulation of Tmax reveals greater divergence, whereas Tmin is better generated. The distinction between the three techniques is somewhat blurred. None of the methods were found to be superior to the others and each has been shown to be a good estimator in some cases. This study concludes that all proposed methods comprise useful tools for simulating daily temperatures, as the high correlation coefficients, between observed and downscaled values, have demonstrated. However, the importance of local factors, which affect the natural variability of temperature, has been emphasised indicating that the geography of a region constitutes an important and rather complex factor, which should be included in models to improve their performance.

Δημοσίευση σε επιστημονικό περιοδικό Summarization: A well designed Medium Access Control (MAC) protocol for wireless networks should provide an efficient mechanism to share the limited bandwidth resources, and satisfy the diverse and usually contradictory Quality of Service (QoS) requirements of each traffic class. In this paper a new MAC protocol for next generation wireless communications is presented and investigated. The protocol uses a combined Packet Discard/Forward Error Correction scheme in order to efficiently integrate MPEG-4 videoconference packet traffic with voice, SMS data and web packet traffic over a noisy wireless channel of high capacity. Our scheme achieves high aggregate channel throughput in all cases of traffic load, while preserving the Quality of Service (QoS) requirements of each traffic type, and is shown to clearly outperform DPRMA, another efficient MAC protocol proposed in the literature for multimedia traffic integration over wireless networks. Presented on: Wireless Personal Communications

The orthogonal method, a powerful and versatile array design procedure, is implemented to the synthesis of conformal slot arrays that reside on a perfectly conducting elliptic cone. In the design scheme, coupling between the slots is taken into account. The coupling information is derived through a numerically rigorous technique based on a full wave analysis. Two arrays, a circumferential and a quasi-radial, are synthesized. In the design examples, constraints on the side lobe level, on scanning capabilities and on cosecant pattern shaping are included.

The design of a base station antenna for mobile communications is presented. The orthogonal method (OM) is applied under constraints on nulls of the radiation pattern. In the synthesis process the mutual coupling between the elements of the antenna array could be taken into account. Beam tilting and direction of arrival are also considered. The whole design is completed by implementing a special architecture of the antenna. Finally, some examples show the applicability of our technique.

Assessment of the reliability of NCEP-NCAR reanalysis data has been the subject of much recent climatological research. In this study, an attempt is made to evaluate the reanalysis data for maximum and minimum temperatures over Greece for the period 1958–2000. Considering that available observations for Greek stations are not included as input in the NCEP-NCAR reanalysis data, the evaluation was made using gridded observational data derived from long time series for the examined area, using an objective scheme. The reanalysis data were compared with respect to the intra-annual variability for extreme years, the inter-annual variability of the corresponding temperature anomalies, and their ability to represent cold and warm spells. Also, the correlation patterns between the two datasets of daily and monthly values were examined. In general, it was found that there was good agreement between the two datasets, although some regional and seasonal differences existed and these were associated with topographical features not correctly represented by the reanalysis model resolution, such as land-sea distribution and orography.

In this work, a novel method is presented, with which the safe space around aperture antennas can be assessed. The basis of this new approach is the approximate similarity of the contours between uniformly and non-uniformly illuminated apertures. The isoparametric contours that result from numerical calculations have to be replaced by envelope contours that fully enclose them, in order to avoid radio frequency hazards. These envelopes were approximated with analytical formulas. Various examples of different apertures are presented, which demonstrate the mode of application and the validity of our method.

¶A spatio-temporal analysis of the dry spells that occur in the Greek area is carried out for an extended period of 40 years (1958–1997). The dry spells can be defined as a number of consecutive days with no rain. The number of days defines the length of the dry spells. The longest spells are identified in central (Cyclades) and the south-east Aegean Sea whereas dry spells with the minimum length are shown over the north-west of the Greek area that reflects the significance of the latitude and the topography. Negative Binomial Distribution and Markov Chains of second order have been used to fit the duration of the dry spells of different lengths. The study of the seasonal and annual distribution of the frequency of occurrence of dry spells revealed that the dry spells in Greece depict a seasonal character, while medium and long sequences are associated with the duration and hazards of drought.

This article is an appraisal of the use of CT in the management of patients with unstable abdominal trauma. We examined 41 patients with abdominal trauma using noncontrast dynamic CT. In 17 patients a postcontrast dynamic CT was also carried out. On CT, 25 patients had hemoperitoneum. Thirteen patients had splenic, 12 hepatic, 6 pancreatic, 8 bowel and mesenteric, 12 renal and 2 vascular injuries. Seven patients had retroperitoneal and 2 patients adrenal hematomas. All but five lesions (three renal, one pancreatic, and one splenic) were hypodense when CT was performed earlier than 8 h following the injury. Postcontrast studies (n = 17), revealed 4 splenic, 3 hepatic, 1 pancreatic, 3 renal, and 2 bowel and mesenteric injuries beyond what was found on noncontrast CT. Surgical confirmation (n = 21) was obtained in 81.81 % of splenic, 66.66 % of hepatic, 83.33 % of pancreatic, 100 % of renal, 100 % of retroperitoneal, and 85.71 % of bowel and mesenteric injuries. The majority of false diagnoses was obtained with noncontrast studies. Computed tomography is a remarkable method for evaluation and management of patients with hemodynamically unstable abdominal trauma, but only if it is revealed in the emergency room. Contrast injection, when it could be done, revealed lesions that were not suspected on initial plain scans.

The model-matching problem for systems described by external models is considered in frameworks of both external and input-output equivalence. Necessary conditions for the solvability of the problem are produced, and it is shown that in certain cases these conditions are also sufficient. In the case where necessary and sufficient conditions exist, the solutions of the problem are obtained in a constructive way and a parametrization of solutions is given.

Type 1 diabetes or insulin-dependent diabetes mellitus (IDDM) is due to autoimmune destruction of pancreatic beta-cells. Genetic susceptibility to IDDM is encoded by several loci, one of which (IDDM2) maps to a variable number of tandem repeats (VNTR) minisatellite, upstream of the insulin gene (INS). The short class I VNTR alleles (26-63 repeats) predispose to IDDM, while class III alleles (140-210 repeats) have a dominant protective effect. We have reported that, in human adult and fetal pancreas in vivo, class III alleles are associated with marginally lower INS mRNA levels than class I, suggesting transcriptional effects of the VNTR. These may be related to type 1 diabetes pathogenesis, as insulin is the only known beta-cell specific IDDM autoantigen. In search of a more plausible mechanism for the dominant effect of class III alleles, we analysed expression of insulin in human fetal thymus, a critical site for tolerance induction to self proteins. Insulin was detected in all thymus tissues examined and class III VNTR alleles were associated with 2- to 3-fold higher INS mRNA levels than class I. We therefore propose higher levels of thymic INS expression, facilitating immune tolerance induction, as a mechanism for the dominant protective effect of class III alleles.

A unified formulation for superdirective end-fire arrays by using Chebyshev and Legendre Polynomials and their maximum directivities as well as the corresponding efficiency index and theQ factor are found. Several examples show the simplicity of the formulation.

Monthly precipitation data from 10 stations (Patras, Corfu, Hvar, Trieste, Venice, Florence, Rome, Naples, Catania and Malta) in the Central Mediterranean area are used for a period of 95 years (1894–1988). The homogeneity of these precipitation time series is tested and their statistical characteristics are analysed. An abrupt climatic change is found at Naples and Rome. The application of Principal Component Analysis (PCA) has yielded three groups of stations where the precipitation data indicate similar fluctuations. Group A includes the stations situated along the coasts of the Ionian and Adriatic seas and the station Naples, while Group B includes the Northern Italian stations and Group C includes the stations at Catania and Malta. In all three groups maximum precipitation was observed during the 1930s. The periodicities of the scores of the significant components have been studied by spectral analysis and significant periodicities of 13.6, 3.5 and 2.2 years were found. Finally, a discussion of the relationships between these precipitation fluctuations and circulation types over the Mediterranean is presented.

1459 Parental Intention to Have Children Vaccinated with H1N1 Vaccine. A Comparative Study in the Multicultural Area of North Evros

Introduction Cat scratch disease is an infectious disease transmitted by young cats, in which the principal causative factor is Bartonella henselae. The typical course of cat scratch disease is usually benign and self-limited and requires only supportive therapy. However, cases lasting up to 2 years have been reported, and more serious complications may occur. Many manifestations of the disease have been reported by different medical disciplines. Case presentation A case of cat scratch disease in a 71-year-old Greek woman with an unusual clinical course is presented here. Serous otitis media was combined with rotational vertigo due to labyrinthitis. The invaded ear was ipsilateral to the inoculation site. Conclusion Cervicofacial lymphadenopathy has been demonstrated as the most common otolaryngologic manifestation of cat scratch disease. Manifestation in the middle and inner ear has, to the best of our knowledge, not been reported before. Our report presents a patient with cat scratch disease with clinical signs and symptoms in the middle and inner ear.

Background The adrenal gland is one of the common sites of metastasis from primary lung cancer. Adrenal metastases are usually unilateral however bilateral adrenal metastases are seen in 10% of all lung cancer patients; of these 2–3% occurs at the initial presentation of non-small cell lung cancer. Secondary tumors can disrupt the structure and function of the adrenal. This can lead to adrenal hemorrhage, which constitutes a life threatening hazard for the patient.