This work presents a model for assigning trust values to agents operating within a collaborative multi-agent system. The model enables agents to assess the trustworthiness of their peers, and thus, to be able to select reliable ones for cooperation and coalition formation. In this work, the performance of a group of agents – a team – that collaborate to achieve a shared goal where the individual contribution of each agent is unknown, is evaluated. The work thus aims to present a reliable method for calculating a trust value for agents involved in teamwork. More specifically, this research presents a model – called Inducing the Trust Ratio Model - for evaluating the individual trustworthiness of a group of agents. Toward this end, the model makes use of genetic algorithms to induce the trust ratio of each coalition member. Empirical analysis is undertaken to evaluate the effectiveness of this model

The preparation of metal (II) complexes [CoCl(2).6H(2)O, Ni(CH(3)COO)(2).4H(2)O, Cu(CH(3)COO)(2).2H(2)O, and Zn (CH3COO)(2) .2H(2)O] with 2[N-(cinnamlidene) amino]-5-nitro phenol as a novel ligands and their biological evaluation against candida species was studied. The inhibitory effects of the tested metal complexes were tested against six pathogenic yeasts (Candida albicans, C. fructus, C. glabrata, C. oleophila, C. parapsilosis, and C. tropicalis). The effect of the most efficient metal complex (Zn(II) complex) was more pronounced at 1.25 microg/ml, while Ni(II) complex was exhibited the least suppressive effect. Co(II) and Zn(II) complexes act as potential antitumor agents, while Zn(II) complex has shown promising cytotoxic activity with slow candidal respiration rate. Addition of Zn(II) complex leading to suppression of cell wall components in all candidal cells accompanied with leaking out of amino acids. Purification of the cell wall mannoprotein of C. glabrata treated with Zn(II) complex was established, resulting one pure fissured protein peak. Cell wall protein modulation was showed by appearance of two new protein bands with molecular weights of 72 and 39 KDa in C. glabrata cells treated with Zn(II) complex compared with one pure protein band 55.6 KDa in the non treated yeast cell.

The preparation of metal (II) complexes [CoCl(2).6H(2)O, Ni(CH(3)COO)(2).4H(2)O, Cu(CH(3)COO)(2).2H(2)O, and Zn (CH3COO)(2) .2H(2)O] with 2[N-(cinnamlidene) amino]-5-nitro phenol as a novel ligands and their biological evaluation against candida species was studied. The inhibitory effects of the tested metal complexes were tested against six pathogenic yeasts (Candida albicans, C. fructus, C. glabrata, C. oleophila, C. parapsilosis, and C. tropicalis). The effect of the most efficient metal complex (Zn(II) complex) was more pronounced at 1.25 microg/ml, while Ni(II) complex was exhibited the least suppressive effect. Co(II) and Zn(II) complexes act as potential antitumor agents, while Zn(II) complex has shown promising cytotoxic activity with slow candidal respiration rate. Addition of Zn(II) complex leading to suppression of cell wall components in all candidal cells accompanied with leaking out of amino acids. Purification of the cell wall mannoprotein of C. glabrata treated with Zn(II) complex was established, resulting one pure fissured protein peak. Cell wall protein modulation was showed by appearance of two new protein bands with molecular weights of 72 and 39 KDa in C. glabrata cells treated with Zn(II) complex compared with one pure protein band 55.6 KDa in the non treated yeast cell.

PURPOSE: Recent data demonstrate that age may be a significant independent prognostic variable following treatment for renal cell carcinoma. We analyzed data from the SEER (Surveillance, Epidemiology and End Results) database to evaluate the relative survival of patients treated surgically for localized renal cell carcinoma as related to tumor size and patient age.

MATERIALS AND METHODS: Patients in the SEER database with localized renal cell carcinoma were stratified into cohorts by age and tumor size. Three and 5-year relative survival, the ratio of observed survival in the cancer population to the expected survival of an age, sex and race matched cancer-free population, was calculated with SEER-Stat. Brown's method was used for hypothesis testing.

RESULTS: A total of 8,578 patients with surgically treated, localized renal cell carcinoma were identified. While 3 and 5-year survival for patients with small (less than 4 cm) renal cell carcinoma was no different from that of matched cancer-free controls, patients treated for large (greater than 7 cm) localized renal cell carcinoma experienced decreased 5-year relative survival across all age groups. Therefore, age was not a significant predictor of relative survival for patients with small (less than 4 cm) or large (greater than 7 cm) tumors. However, a statistically significant trend toward lower relative survival with increasing age was demonstrated in patients with medium size tumors (4 to 7 cm). Hypothesis testing confirmed these findings.

CONCLUSIONS: These data suggest that relative survival is high in patients with tumors less than 4 cm and lower in patients with tumors larger than 7 cm regardless of age. However, increasing age may be related to worse outcomes in patients with tumors 4 to 7 cm. The cause of this observation warrants further investigation.

UNLABELLED: The aim of this study was to detect the accuracy of routine magnetic resonance imaging (MRI) done in different centres and its agreement with arthroscopy in meniscal and ligamentous injuries of the knee. We prospectively examined 70 patients ranging in age between 22 and 59 years. History taking, plain X-ray, clinical examination, routine MRI and arthroscopy were done for all patients. Sensitivity, specificity, accuracy, positive and negative predictive values, P value and kappa agreement measures were calculated. We found a sensitivity of 47 and 100%, specificity of 95 and 75% and accuracy of 73 and 78.5%, respectively, for the medial and lateral meniscus. A sensitivity of 77.8%, specificity of 100% and accuracy of 94% was noted for the anterior cruciate ligament (ACL). We found good kappa agreements (0.43 and 0.45) for both menisci and excellent agreement (0.84) for the ACL. MRI shows high accuracy and should be used as the primary diagnostic tool for selection of candidates for arthroscopy.

LEVEL OF EVIDENCE: 4.

A blend of poly(trimethylene terephthalate) (PTT) and polycarbonate with a weight ratio of 50/50 was studied by means of differential scanning calorimetry (DSC) and dielectric spectroscopy (DS) after melt annealing that enables transesterification. The DSC results show that with increasing the residence time in the melt, the melting temperature and the heat of fusion of PTT crystals decrease. Prolonged thermal treatment at 300 °C gives rise to a copolymer that no longer reveals melting or crystallization. Additional annealing of such samples below the melting temperature of PTT results in restoration of the crystallization ability. The amorphous phase dynamics is studied by means of DS demonstrating that the glass transition relaxations are very sensitive to the crystallinity changes. The random copolymer is characterized by only one α-relaxation indicating a more or less homogeneous amorphous phase. In contrast to this, the physical blend and the block copolymers show two α-relaxation processes attributed to the existence of two amorphous fractions. Analysis of the relaxation process in terms of Vogel-Fucher-Tammann- Hesse model reveals a correlation between the fragility parameter and the extent of trans-reaction. The crystallization kinetics of the blocky copolymer determined from the changes of the dielectric constant with time are discussed and compared with pure PTT. © 2008 Springer Science+Business Media B.V.