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Early stages modelling of processes involves issues of classification of variables into inputs, outputs and internal variables, referred to as Model Orientation Problem (MOP) which may be addressed on state space implicit, or matrix pencil descriptions. Defining orientation is equivalent to producing state space models of the regular or singular type. In this paper we consider autonomous differential descriptions defined by matrix pencils and then search for strict equivalence transformations which introduce the partitioning of the implicit vector into states and possible inputs and outputs, referred to as system orientation. The Kronecker invariant structure of the matrix pencil description is shown to be central to the solution of system orientation and this is expressed as a problem of classification and partitioning of the Kronecker invariants. It is shown that the types of Kronecker invariants characterise the nature of the system orientation solutions. Studying the conditions, under which such oriented models may be derived, as well as their structural properties in terms of the Kronecker structure, is the issue considered here.

Statement of problem Although numerous studies have been performed on the accuracy of intraoral scanners, determining the clinical significance of the results is problematic. Purpose The purpose of this in vitro study was to evaluate the trueness and precision of 4 intraoral optical scanners (IOSs) on a 6-implant model and provide a method to help determine clinical significance. Material and methods A polymer mandibular edentulous model with 6 hexagonal scan bodies (Ritter) was fabricated, and a control scan was made by using an industrial laser line probe (FARO Edge HD Arm). Four IOSs (True Definition, TRIOS, CEREC Omnicam, Emerald Scanner) were used to scan the same model 5 times: the 20 standard tessellation language (STL) files were individually imported to a 3D inspection software program (Geomagic Control X) and superimposed over the computer-aided design (CAD) control scan. The tolerance was set at a limit of ±0.01 mm. Results None of the tested scanners were true even 10% of the time at the ±0.01-mm tolerance, and the Emerald scanner was true less than 5% of the time. Within scanners, results were precise, showing variations of no more than 2% over repeated scans. When a ±0.05-mm tolerance was selected, the percentage within tolerance increased dramatically. This made the performance of the scanners to appear better but obscured valuable information. The 3D color map was the best method for understanding the data. The color maps showed how much was within tolerance and, equally important, the amount and direction of out of tolerance, providing an easily understandable qualitative and quantitative image. Conclusions No statistical or clinical differences were found among the scanners tested. The 3D map was the best method for observing the data.

We evaluated the outcomes of total hip arthroplasty in 67 patients (86 hips) with congenital hip disease and excessive abnormal anatomy of the proximal femur with the use of custom-made femoral stems. The design of the stem was based on CT data following the principles of CAD-CAE-CAM technique. No serious complications attributed to the femoral stem were seen. Within a median follow-up of 127.5 months the 10-year survival of any of the components was 95.4% and respective value when aseptic loosening of the stem was considered was 98.1%. Patients with high dislocations had a 10-fold risk for loosening compared to those with low dislocations. No other parameter was associated with outcomes. The clinical and radiological evaluation was in consistency with the above outcomes.

Hepatitis D virus (HDV) has decreased in Europe, but recent reports indicate a rising trend. We report the epidemiological changes, clinical progress, and effect of treatment on the natural course of HDV infection in Greece during the last 13 years.Prospective data were extracted from the HepNet.Greece Cohort-Study.Since 1997, 4673 chronic HBV (CHB) cases (4527 adults, 146 children) have been followed prospectively. Two thousand one hundred thirty-seven patients were tested for anti-HDV [101 (4.7%) positive]. Anti-HDV testing in Greece decreased significantly (57.0% before 2003, 35.3% thereafter; p0.001). Anti-HDV prevalence among HBsAg-positives was 4.2%; lower in native Greeks (2.8%) than in immigrants (7.5%) or in children (15.3%; p0.001). Within 2.3 years of follow-up, HDV occurred in 11/2047 HBsAg-positive patients (2.2 new delta-infected adults and 8.7 children per 1000 HBsAg-positive annually). HDV-positive compared to CHB adults were younger (p=0.035) and had more active and advanced disease at baseline, as indicated by laboratory indices and the higher prevalence of cirrhosis at younger age. During a 4.2-year median observation, significantly more anti-HDV-positive than CHB adults developed a liver-related first event (20.0% vs. 8.5%, p Log-rank=0.014).Treatment was received by 46/90 (51.1%) patients, 40 of them interferon-based. In multivariable analysis, interferon significantly decreased disease progression in HDV-positive patients [HR=0.14 (95% CI: 0.02-0.86; p=0.033)].In Greece, HDV serology is currently tested in only one-third of HBsAg-positive patients. HDV prevalence is lower in native Greeks compared to immigrants, who may contribute50% of the HDV infection burden in Greece. Data show that HDV infection is a rapidly progressive disease, but interferon-based treatment may alter its course.

Background Despite the beneficial effects of epidurals in intra-abdominal surgery, the incidence of anastomotic leak remains controversial when used. Moreover, studies have also shown that fluid overload may be deleterious to anastomoses. The purpose of this paper is to evaluate the effects of varying intraoperative fluid protocols, in the presence of an epidural, on the burst pressure strength of colonic anastomoses. Methods An epidural was installed in 18 rabbits, divided into three groups. Group 1 received 30 mL/kg/h Ringer's lactate, Group 2 received 100 mL/kg/h Ringer's lactate, and Group 3 received 30 mL/kg/h Pentaspan. Two colo-colonic anastomoses were performed per rabbit. On postoperative day 7 the anastomoses were resected and their burst pressures measured as a surrogate for anastomotic leak. Results When comparing the average burst pressures of all three groups, there was a significant difference (P = 0.04). The anastomoses in the 100 mL/kg/h Ringer's lactate group were shown to be the weakest, with 64% of the anastomoses having burst under 120 mm Hg. The rabbits hydrated with Pentaspan had the highest strength, with no anastomoses bursting under 120 mm Hg. This translated into significant burst pressure differences (P = 0.02) between Group 2 and Group 3. Conclusion These results suggest that fluid overload with a crystalloid, in the presence of an epidural, may be deleterious to the healing of colonic anastomoses, creating a higher risk of anastomotic leak. Intraoperative resuscitation should thus focus on goal-directed euvolemia with appropriate amounts of colloids and/or crystalloids to prevent the risk of weakening anastomoses, especially in patients with epidurals.

Background. HCV infection and transfusional iron overload in Thalassemic patients may result in liver disease. HCV treatment in Thalassemia has raised safety concerns. Aim. Estimate effectiveness and tolerability of interferon-based therapy in HCV-infected Thalassemic patients. Material and methods. Over a 12-year period, consecutive patients with β Thalassemia major (TM) and chronic hepatitis C received treatment. Liver biopsy, HCV-RNA and genotyping were performed beforehand. Sustained virological response (SVR) was defined as negative HCV-RNA 6 months post-treatment. Forty eight patients (26 M-22 F, mean age 39.8) were enrolled. Twenty nine patients were treated with conventional interferon alpha (IFNa) for 48 weeks (group A). Nineteen patients (10 naive-9 previously IFNa experienced) received pegylated interferon (PEGIFN) (group B). Results. HCV-1 was found in 44%, HCV-2 in 14%, HCV-3 in 23% and HCV-4 in 19%. Group A: ten patients (38.5%) achieved SVR, 2 (7.5%) relapsed and 17 (54%) were non responders. Group B: five (28%) achieved SVR, 8 (44%) relapsed and 6 (28%) never responded. High HCV-RNA levels, genotype 1 and advanced liver fibrosis were independently associated with no response. Four patients (3 treated with IFNα, 1 with PEG-IFN) had to discontinue treatment due to complications. Conclusions. The response rate of IFN monotherapy in multi-transfused, HCV-infected Thalassemic patients is not inferior to that in nonmulti-transfused patients. IFNa administration is well-tolerated and should be recommended as initial treatment schedule in this setting.

The disturbance decoupling and the simultaneous disturbance and input-output decoupling problems for singular systems are considered in the context of the matrix fraction description (MFD) of the system. Solvability conditions are obtained in terms of the composite matrix of a column reduced MFD of the system, a characterisation of the fixed poles of both problems is given and it is shown that the remaining poles can be arbitrarily assigned.

A visible abutment-restorative interface is a problematic consequence, especially in the esthetic zone. This article presents formulas to predict the vertical tissue position around the abutment-restoration, which can be used both as a guide to the clinical situation and as an aid to computer-aided design and computer-aided manufacturing design.

Decoy receptor-3 (DcR3) is a member of the TNF receptor superfamily of proteins, which has been implicated in anti-apoptotic and anti-inflammatory pathways, via binding to TL1A, LIGHT and Fas-L. The role of the TL1A/DcR3 ligand/receptor pair in ulcerative colitis (UC) has not been studied. We investigated the systemic (peripheral blood) and local (large intestine) expression of DcR3 and TL1A in 64 patients with UC and 56 healthy controls. DcR3 serum concentrations were highly elevated in patients with active UC (P

The disturbance decoupling and the simulteneous disturbance and input – output decoupling problems for singular systems are considered in the context of the matrix fraction description (MFD) of the system. Solvability conditions are obtained in terms of the composite matrix of a column reduced MFD of the system, a characterisation of the fixed poles of both problems is given and it is shown that the remaining poles can be arbitrarily assigned.

An estimation of the future changes in the extreme conditions over the Greek area has been attempted, by applying the output data from a GCM to two different statistical downscaling models. The first was a multiple linear regression model based on a circulation type approach (MLRct) and the second one used artificial neural networks (ANNs). Two extreme temperature indices (txq90, tnq10) and two extreme precipitation indices (pq90, pxcdd) were selected for the study and simulated by the statistical models. From the comparison of the models during a validation period, it was found that the MLRct was relatively more efficient and the circulation types were proven to be a more reliable predictor. However, both the models underestimated the natural variability of the observed time-series. Generally, the extreme temperature indices were simulated better than the precipitation ones and winter was the season that showed the highest downscaling skill. Subsequently, the present day and future extreme temperature and rainfall conditions were examined using four ensemble members (control runs) and five scenarios driven by the A2 and B2 emission SRES scenarios, from the atmospheric general circulation model HadAM3P. Concerning extreme temperatures, an increase of their values is expected during the future period 2070–2100, according to the MLRct model. The climate change signal of the ANNs model was not so strong and in some cases it was of opposite direction. The results for the extreme precipitation indices showed a spatial incoherence and more complex structure of change.

Δημοσίευση σε επιστημονικό περιοδικό Summarization: Both call admission control (CAC) and efficient scheduling are of great importance in next generation wireless networks, which are expected to handle various types of highly demanding multimedia users. In this paper, we present and evaluate a new mechanism which combines CAC with bandwidth allocation in a high-speed downlink time division multiple access (TDMA) wireless channel with errors; our mechanism incorporates predictions of the wireless channel condition in its decision making and our results show that, with the use of the feedback between the scheduler and the admission controller, system performance is significantly enhanced (in terms of voice-WAP-SMS-H.263 video QoS) compared to a scheme without prediction on the channel condition. Presented on: AE� - International Journal of Electronics and Communications / Archiv f�r Elektronik und �bertragungstechnik

The novel vanadium bromide (V/Br) redox flow cell employs a vanadium(II)/vanadium(III) couple in the negative half-cell and a Br−/Br3− couple in the positive half-cell, using a mixture of vanadium bromide, hydrobromic acid and hydrochloric acid as the electrolyte in both half-cells. An ion exchange membrane separates the two V/Br half-cell electrolytes. In this project, small test cell cycling experiments were conducted to evaluate the performance of a range of ion exchange membranes in the V/Br redox flow cell. The features and charge/discharge results of the V/Br redox flow cell will also be discussed in this paper.

Δημοσίευση σε επιστημονικό περιοδικό Summarization: In this paper we design and study the performance of a Multiple Access Control (MAC) scheme for the multiplexing and the integrated delivery of voice, video and bursty data traffic over a high-speed wireless TDMA channel. We compare our results with a previously proposed efficient MAC protocol and we show that, regardless of the much more severe (and realistic) channel conditions examined in our work, our scheme clearly outperforms the previously proposed protocol in terms of channel throughput and voice capacity, due to the use of two novel ideas. Presented on: Computer Communications

The conformers of the 2-, 3- and 4-substituted phenolic cation radicals, 2-X-, 3-X- and 4-X-ArOH + , and the respective phenoxyl radicals, ArO , the intramolecular hydrogen bond strength (Δ H intra ) estimate along with the electronic effects of five electron withdrawing (EWG) and eight electron donating groups (EDG) on the gas-phase O–H proton dissociation enthalpies, (PDEs), of the short-lived, 2-X-ArOH + , (involved in the single-electron transfer antioxidant mechanism), are studied at the DFT/B3LYP level of theory. EWG result to smaller PDEs, hence to stronger acidity; EDG to weaker acidity. The deprotonation antioxidant mechanistic step is not a rate-controlling step for 2-X-ArOH to scavenge free radicals. Approximate estimations of the ΔPDEs (hence acidities as well) can be derived from calculated structural and/or vibrational frequency values. Δ H intra s correlate reasonably with geometrical parameters for the closed-shell, neutral counterparts, in contrast with previous estimates.

A systematic investigation of the CuCl2/Mebta (Mebta = 1-methylbenzotriazole) reaction system is described, involving the determination of the influence of the CuII:Mebta ratio, the nature of solvent and the presence of counterions on the identity of the reaction products. As a consequence, complexes [Cu2Cl4(Mebta)4] (1), [CuCl2(Mebta)2] (2), {[Cu2Cl4(Mebta)2]}n (3), [Cu4OCl6(Mebta)4] · 0.25H2O (4 · 0.25H2O) and [Cu2Cl2(Mebta)6](ClO4)2 (5) have been isolated and structurally characterized by single-crystal X-ray studies. Mebta behaves as a monodentate ligand binding through N(3). 1 is a dinuclear complex, the structure of 2 consists of discrete monomeric units, and that of 3 is composed of linear, well-separated polymeric chains of CuII atoms. The molecules of 4 · 0.25H2O have a central μ4-oxide ion surrounded tetrahedrally by four CuII atoms. In the cations of 5 the two CuII centres are asymmetrically bridged by two chloro ligands, with three Mebta molecules completing five coordination at each metal. Complexes were characterized by spectroscopic (IR, far-IR, solution UV/Vis) and thermal decomposition (TG, DTG, and DTA) techniques. Variable-temperature magnetic susceptibility data for 1, 3 and 5 showed intramolecular (1, 5) and intrachain (3) ferromagnetic exchange interactions. Estimates of the Jparameters, experimentally derived, were in close agreement with a new magneto-structural criterion developed by us, holding for bis(μ-chloro) copper(II) dimers. A comparison between the CuCl2/Mebta and CuBr2/Mebta systems is also presented.

Early stages modelling of processes involves issues of classification of variables into inputs, outputs and internal variables, referred to as Model Orientation Problem (MOP) which may be addressed on state space implicit, or matrix pencil descriptions. Defining orientation is equivalent to producing state space models of the regular or singular type. Studying the conditions, under which such models may be derived, as well as the structural properties of the resulting oriented problems, is one of the issues considered here. Oriented models of the S(A,B,C,D) type have transfer functions which may not be well behaving as far as properties of input, output regularity and nondegeneracy. Defining subsystems by reduction of the number of inputs, outputs such that the resulting transfer function is well behaved as far as preservation of degeneracy, is a problem considered in the context of systems having physical input, output variables, which have to be preserved.

Computer-assisted design and computer-assisted milling (CAD/CAM) technology has been shown to be an effective dental treatment adjunct. This article demonstrates its use in the fabrication of an in-office, one visit, porcelain laminate veneer.

Transfer function models used for early stages of design are large dimension, contain all possible physical inputs, outputs, may be badly conditioned and possibly degenerate. The problem considered here is the selection of maximal cardinality subsets of the physical input, output sets, such as the resulting model is nondegenerate and satisfies additional properties such as controllability and observability and avoids the existence of high order infinite zeros. Conditions for characterisation of such properties are given. A selection procedure for natural subsets of inputs and outputs, which guarantee well conditioning in the above sense, may be based on these criteria.

The minisatellite DNA polymorphism consisting of a variable number of tandem repeats (VNTR) at the human INS (insulin gene) 5'-flanking region has demonstrated allelic effects on insulin gene transcription in vitro and has been associated with the level of insulin gene expression in vivo. We now show that this VNTR also has effects on the nearby insulin-like growth factor II gene (IGF2) in human placenta in vivo and in the HepG2 hepatoma cell line in vitro. We show that higher steady-state IGF2 mRNA levels are associated with shorter alleles (class I) than the longer class III alleles in term placentae. In vitro, reporter gene activity was greater from reporter gene constructs with IGF2 promoter 3 in the presence of class I alleles than from those with class III. Taken together with the documented transcriptional effects on the insulin gene, we propose that the VNTR may act as a long range control element affecting the expression of both INS and IGF2. The localization of a type 1 diabetes susceptibility locus (IDDM2) to the VNTR itself suggests that either or both of these genes may be involved in the biologic effects of IDDM2.

A new approach to the row by row decoupling of singular systems via state feedback and regular input transformation is presented. The proposed method is based on the matrix fraction description of the system and is an extension of the frequency domain method for strictly proper systems. The solvability condition of the problem is readily obtained from the ‘numerator’ matrix of a coprime and column reduced matrix fraction description of the given system. Pole placement and decoupling is also considered, and the characterization of the fixed poles is given.

The problem of canonical forms of implicit descriptor systems under restricted system equivalence is considered. It is shown that the canonical form is directly related to the echelon form of the autoregressive matrix inducing the external behavior of the system. The proposed canonical form is a generalization of the Popov form, and is also valid for singular systems, under transfer equivalence.

The input-output decoupling problem for singular systems via state feedback and regular input transformation is considered. The treatment of the problem is in the frequency domain and it is an extension of the state-space systems case. The polynomial matrix approach is shown to be considerably simpler than the existing methods and the solvability conditions are readily obtained from the "numerator" matrix of a coprime and column reduced MFD of the given system. Pole placement issues are also considered and a characterisation of the fixed poles of the system is given.

Resume Nous considerons une forme canonique du type Popov pour des systemes singuliers avec sorties, sous l'action de l'equivalence restreinte des systemes. Nous decrivons les transformations qui conduisent a cette forme canonique et nous montrons que celle-ci est directement liee a la matrice composee, issue d'une factorisation de la matrice du transfert du systeme. Elie met en evidence, de maniere tout a fait transparente, les indices d'atteignabilite du systeme et permet de classifier, par simple inspection, les indices de commandabilite propres et nonpropres.

For linear systems, a family of cover problems of the geometric theory are introduced as extensions of the standard cover problem and a matrix pencil formulation of such problems is given. It is shown that the solvability of such problems is reduced to a problem of Kronecker Invariant Transformation by Matrix Pencil Augmentation and a Matrix Pencil Realisation Problem. Necessary, as well as sufficient conditions for solvability of both problems are given, which lead to a number of conditions for solvability of the partial, as well as standard cover problem. The special cases of left regular, regular solutions of the cover problem are investigated and a parametrisation of such families of solutions is given.

Evaluation: Without exception, the menus prepared by staff, students, and the visiting foodservice professionals (FSP) received good reviews. The foodservice directors have added many of the recipes to the regular menu at the high schools and plan to take them into the elementary and middle schools as well. The changes are being well received by the students. Conclusions and Implications: The participating FSP exemplify the idea that attitude is everything and that students are open to different eating experiences; that adults often underestimate their interest in trying new food. Their experience exhibits the need to continue offering new foods and that the more these new recipes are provided, the easier it will get. These FSP also involve students in the decision-making. Everyone wants to feel empowered to make their own choices; our role is to nudge them toward the healthy ones. Funding: USDA Team Nutrition TN 2011.

Introduction The aim of the study is to define whether the measurement of c-Kit protein serum levels can be used as a biomarker of response to treatment or disease progression in patients with GIST. Methods In a period of one year, we monitored 9 patients with GIST (6 men, 3 women), age from 46 to 77 years old (mean age 61). They had all been under endoscopic, imaging and histological follow up. Serum detection of c-Kit protein was determined by flow cytometry, performed with MILLIPLEX MAP Total c-Kit MAPmates pair, in conjunction with the MILLIPLEX MAP Cell Signaling Buffer and Detection Kit (Merck Millipore, USA), to detect the presence of total c-kit in cell lysates, using the Luminex IS100 System (Luminex corp, USA). Cut-off levels were determined according to the manufacturer's instructions. Results First of all, it is important to notice that four patients (3 men, 1 woman), had negative value of serum c-Kit three months after surgery, that turned into positive at the time of tumor relapse. A reduction in the titre of c-Kit protein in serum (from positive to negative values), was recorded in three patients (2 men, 1 woman), three months after surgery. One of them, presented with negative value of c-Kit before surgery that turned into positive when tumor relapsed. Moreover, one patient with GIST had a negative value of c-Kit protein in serum, both before and after surgery. Finally, another patient was recorded with positive c-kit in serum before surgery, that turned into negative three months after, and was rendered again positive at the time of tumor relapse. Serum c-Kit levels turned into negative when imatinib mesylate was administrated and finally became positive when relapse was clinically suspected. Conclusion Similarly to epithelial tumor markers, measurement of serum c-Kit levels in patients with GIST, seems to be a reliable and easy to perform serum biomarker for the clinical monitoring of these patients. Nevertheless, further well-organized, large studies and clinical trials are required in order to establish its use in everyday clinical practice.