University of Patras

About: University of Patras is a education organization based out in Pátrai, Greece. It is known for research contribution in the topics: Population & Catalysis. The organization has 13372 authors who have published 31263 publications receiving 677159 citations. The organization is also known as: Panepistímio Patrón.

Personal Teaching Efficacy and Its Sources: Student Teachers' Perceptions.

Abstract: Teachers’ confidence in their ability to perform the actions that lead to student learning is one of the few individual characteristics that predicts teacher practice and student outcomes. Teachers and especially student teachers need strong efficacy beliefs in order to continue teaching during in‐service education. The current study explores the factors that precede student teachers’ beliefs of teaching efficacy and determine their conviction that they can influence instructional strategies, classroom management, and students’ engagement. In the study 198 fourth‐year students from two primary education departments in Greece completed a Teacher Efficacy Sources Inventory and a Teachers’ Sense of Efficacy Scale. It was found that self‐perceptions of teaching competence, personal characteristics, and motivation for teaching were contributory factors to teaching efficacy. The search for this type of information from student teachers is based on the assumption that feedback from students comprises a substanti...

Global distribution of particle phase state in atmospheric secondary organic aerosols

Abstract: Secondary organic aerosols (SOA) are a large source of uncertainty in our current understanding of climate change and air pollution. The phase state of SOA is important for quantifying their effects on climate and air quality, but its global distribution is poorly characterized. We developed a method to estimate glass transition temperatures based on the molar mass and molecular O:C ratio of SOA components, and we used the global chemistry climate model EMAC with the organic aerosol module ORACLE to predict the phase state of atmospheric SOA. For the planetary boundary layer, global simulations indicate that SOA are mostly liquid in tropical and polar air with high relative humidity, semi-solid in the mid-latitudes and solid over dry lands. We find that in the middle and upper troposphere SOA should be mostly in a glassy solid phase state. Thus, slow diffusion of water, oxidants and organic molecules could kinetically limit gas-particle interactions of SOA in the free and upper troposphere, promote ice nucleation and facilitate long-range transport of reactive and toxic organic pollutants embedded in SOA.

Increased Bax/Bcl-2 ratio up-regulates caspase-3 and increases apoptosis in the thymus of patients with myasthenia gravis.

Abstract: Background: In this study the possible relation of Bax (an apoptosis promoter) to Bcl-2 (an apoptosis inhibitor) ratio with the apoptosis co-ordination enzyme, caspase-3, in the thymus of patients with myasthenia gravis (MG) was investigated in correlation with long-term clinical prognosis. Patients and Methods: The study included 46 patients (17M/29F, mean age 36.60±16.09 yr) with MG, who underwent thymectomy for treatment. The clinical staging (Osserman classification) included: stage I-5, IIA-21, IIB-17, III-3. The pathology of the thymus showed: hyperplasia-26, atrophy-8, thymoma B1 and B2 type-9, thymoma B3 type (well differentiated thymic carcinoma) -3. The patients were evaluated 39-166 (mean 91.87±38.38) months after thymectomy. At the end of the follow-up period, the patients were classified as follows: group A: complete stable remission, group B: pharmacological remission+minimal manifestations+improvement+deterioration. Paraffin sections of thymic tissue were subjected to: a) immunohistochemistry (bax, bcl-2, caspase-3 protein); b) in situ hybridization (bax, bcl-2 mRNA); and c) TUNEL-stain (apoptotic cells). Bax to bcl-2 mRNA and protein ratio was determined for each sample by dividing the %bax (+) cells by the % bcl-2 (+) cells. Results: Follow-up data were available for 39/46 patients: 13/39 patients belonged to group A and 26/39 to group B. The Bax/Bcl-2 mRNA and protein ratios were increased towards advanced disease stages (+370% for mRNA and +391% for protein, from MG stage I to stage III). These ratios were correlated with caspase-3 expression (r=0.782 and 0.583, p 1(1.47±0.07 for mRNA and 1.52±0.18 for protein). The Kaplan-Meier survival curve showed higher, free of disease, survival in group A (p=0.0082). Cox regression analysis revealed that the Bax/Bcl-2 ratio was an independent prognostic factor, however the p-value was marginally significant (95% CI:1.078-44.073, p=0.041). Conclusion: This study has demonstrated that in patients with MG who underwent thymectomy: a) the Bax/Bcl-2 ratio may up-regulate caspase-3 expression and modulate apoptosis associated with progress of the disease; b) the Bax/Bcl-2 ratio<1 was associated with complete stable remission after thymectomy; and c) Bax/Bcl-2 ratio was an independent predictive marker for therapeutic response after thymectomy. Myasthenia gravis (MG) is an autoimmune disorder caused by a defect of neuromuscular transmission due to an antibody-mediated attack upon the nicotinic acetylocholine receptors. It is characterized by fluctuating weakness that is improved by inhibitors of cholinesterase (1). Myasthenia gravis is associated with thymic hyperplasia in 65% and thymoma in 10% of cases, while MG is present in 30-45% of patients with thymomas (2). Among several therapeutic modalities employed in the treatment of MG, thymectomy is one of the efficient strategies used in the integrated management of the disease (3-5). Today it is well-known that apoptosis maintains homeostasis in living organisms by depleting cells as a response to various stimuli (6). After cell depletion due to apoptosis, tissue remodelling is achieved through cell proliferation and the degree of this remodelling depends on the balance between apoptosis and proliferation. Apoptosis is a morphologically distinct, gene-directed form of cell death characterized by cytoplasmic fragmentation and nuclear condensation that contributes to both physiological and pathological processes (7). Previous studies have