COMMUNITY TEACHERS AND THE PREPARATION OF SPECIAL EDUCATION TEACHERS: A CASE STUDY

The current context of special education classrooms across America is that of an increasing demographic complexity. There is a disproportionate representation of historically marginalized groups (HMGs) in special education that (re)emphasizes a disconnect between those students, their families, and schools. Coupled with a predominantly White middle-class teaching force not being prepared to effectively teach these students, it furthers the marginalization of HMG special education students. Using a feminist-standpoint theoretical framework, the authors put forward a rationale for special education teacher preparation programs to partner with community teachers working in community-based organizations (CBOs) that serve HMGs. The authors contend that this type of partnership results in pre-service teachers being better prepared to address both the demographic complexities and the disconnect between families and schools

Μελέτη οχήματος πόλης με τεχνολογία φιλική προς το περιβάλλον

114 σ.Εθνικό Μετσόβιο Πολυτεχνείο--Μεταπτυχιακή Εργασία. Διεπιστημονικό-Διατμηματικό Πρόγραμμα Μεταπτυχιακών Σπουδών (Δ.Π.Μ.Σ.) "Συστήματα Αυτοματισμού"Η επικράτηση του κινητήρα εσωτερικής καύσης στα οχήματα τον 20ο αιώνα προκάλεσε βλαπτικές παρενέργειες σημαντικής έκτασης και έντασης. έτσι κινητοποιήθηκε το παγκόσμιο επιστημονικό δυναμικό, προκειμένου να εξευρεθούν τρόποι αντιμετώπισης του προβλήματος. Οι αριθμοί των οχημάτων που προστίθενται κάθε χρόνο στην κυκλοφορία επιτείνουν τα φαινόμενα και καθιστούν επιτακτική την ανάγκη λήψης άμεσων μέτρων. Η αντικατάσταση του κιντήρα εσωτερικής καύσης διαφαίνεται ότι είναι θεμα χρόνου. Σκοπός της εργασίας αυτής είναι η ανασκόπιση των τεχνολογικών επιτευγμάτων που θα συμβάλλουν στο σχεδιασμό ενός οχήματος μηδενικής ρύπανσης. Ηχρήση νέων έξυπνων υλικών, η μείωση του βάρους, οι ανανεώσιμες πηγές ενέργειας, η ανλακτηση ενέργειας μέσω φρεναρίσματος είναι μερικές από τις εφαρμογές που αναπτύσσονται. Μακροπρόθεσμα αναμένεται να συμβάλλουν τεχνολογίες όπως οι κυψέλες καυσίμου και τα βιοκαύσιμα, ενώ στο άμεσο μέλλον αναμένεται να κυκλοφορήσουν πολλά ηλεκτρικά υβριδικά οχήματα στην αγορά.The prevalence of internal engine combustion engine vehicles of road transport during the 20th century caused extended damaging side affects. Therefore, the world's scientific potential is working in order for this problem to be confronted. The increase of the vehicles worsens this situation and it is necessary to act immediately against it. The replacement of the internal combustion machine by the electric motor is a matter of time. This dissertation aims to review the overall technological developments which will lead to the design of automobiles with zero emissions. The use of new materials for automobile design, weight reduction, renewable energy sources, regenerative energy from braking are some of the topics that will be discussed. Key technologies such as hydrogen fuel cells, electric cars and biofuels are expected to contribute in the long run. Whereas, hybrid cars are considered as the solution for the near future.Σοφία Γ. Δαΐκο

A study on the material properties of novel PEGDA/gelatin hybrid hydrogels polymerized by electron beam irradiation

Gelatin-based hydrogels are highly desirable biomaterials for use in wound dressing, drug delivery, and extracellular matrix components due to their biocompatibility and biodegradability. However, insufficient and uncontrollable mechanical properties and degradation are the major obstacles to their application in medical materials. Herein, we present a simple but efficient strategy for a novel hydrogel by incorporating the synthetic hydrogel monomer polyethylene glycol diacrylate (PEGDA, offering high mechanical stability) into a biological hydrogel compound (gelatin) to provide stable mechanical properties and biocompatibility at the resulting hybrid hydrogel. In the present work, PEGDA/gelatin hybrid hydrogels were prepared by electron irradiation as a reagent-free crosslinking technology and without using chemical crosslinkers, which carry the risk of releasing toxic byproducts into the material. The viscoelasticity, swelling behavior, thermal stability, and molecular structure of synthesized hybrid hydrogels of different compound ratios and irradiation doses were investigated. Compared with the pure gelatin hydrogel, 21/9 wt./wt. % PEGDA/gelatin hydrogels at 6 kGy exhibited approximately up to 1078% higher storage modulus than a pure gelatin hydrogel, and furthermore, it turned out that the mechanical stability increased with increasing irradiation dose. The chemical structure of the hybrid hydrogels was analyzed by Fourier-transform infrared (FTIR) spectroscopy, and it was confirmed that both compounds, PEGDA and gelatin, were equally present. Scanning electron microscopy images of the samples showed fracture patterns that confirmed the findings of viscoelasticity increasing with gelatin concentration. Infrared microspectroscopy images showed that gelatin and PEGDA polymer fractions were homogeneously mixed and a uniform hybrid material was obtained after electron beam synthesis. In short, this study demonstrates that both the presence of PEGDA improved the material properties of PEGDA/gelatin hybrid hydrogels and the resulting properties are fine-tuned by varying the irradiation dose and PEGDA/gelatin concentration

Atypical Mycobacterial Infection Presenting as Persistent Skin Lesion in a Patient with Ulcerative Colitis

Immunosuppressive drugs are commonly used for the treatment of inflammatory bowel disease. Patients receiving immunosuppressants are susceptible to a variety of infections with opportunistic pathogens. We present a case of skin infection with Mycobacterium chelonae in a 60-year-old Caucasian woman with ulcerative colitis who had been treated with corticosteroids and azathioprine. The disease manifested with fever and rash involving the right leg. Infliximab was administered due to a presumptive diagnosis of pyoderma gangrenosum, leading to worsening of the clinical syndrome and admission to our hospital. Routine cultures from various sites were all negative. However, Ziehl-Neelsen staining of pus from the lesions revealed acid-fast bacilli, and culture yielded a rapidly growing mycobacterium further identified as M. chelonae. The patient responded to a clarithromycin-based regimen. Clinicians should be aware of skin lesions caused by atypical mycobacteria in immunocompromised patients with inflammatory bowel disease. Furthermore, they should be able to thoroughly investigate and promptly treat these conditions

Exploring colistin pharmacodynamics against Klebsiella pneumoniae: A need to revise current susceptibility breakpoints

Objectives: Because the pharmacokinetic/pharmacodynamic (PK/PD) characteristics of colistin against Enterobacteriaceae are not well explored, we studied the activity of colistin against K. pneumoniae in an in vitro PK/PD model simulating different dosing regimens. Methods: Three clinical isolates of K. pneumoniae with MICs of 0.5, 1 and 4mg/L were tested in an in vitro PK/PD model following a dose-fractionation design over a period of 24h. A high and low inoculumof 107 and 104 cfu/mL with and without a heteroresistant subpopulation, respectively, were used. PK/PD indices associated with colistin activity were explored and Monte Carlo analysis was performed in order to determine the PTA for achieving a bactericidal effect (2 log kill). Results: The fAUC/MIC (R2"0.64-0.68) followed by fCmax/MIC (R2=0.55-0.63) best described colistin's 24 h log10 cfu/mL reduction for both low and high inocula. Dosing regimens with fCmax/MIC≥6 were always associated with a bactericidal effect (P=0.0025). However, at clinically achievable concentrations, usually below fCmax/MIC=6, an fAUC/MIC ≤25 was more predictive of a bactericidal effect. Using a dosing regimen of 9 MU/ day, the PTA for this pharmacodynamic target was 100%, 5%-70%and 0%, for isolates with MICs of ≤0.5, 1 and ≥2 mg/L, respectively. Dosing regimens that aim for a trough level of 1 mg/L achieve coverage of strains up to 0.5 mg/L (target trough/MIC=2 mg/L). Conclusions: Characterization of the pharmacodynamics of colistin against Enterobacteriaceae in an in vitro model of infection indicates that a revision of current susceptibility breakpoints is needed. Therapeutic drug monitoring of colistin to achieve pharmacodynamic targets in individual patients is highly recommended

Weak electron irradiation suppresses the anomalous magnetization of N-doped diamond crystals

Several diamond bulk crystals with a concentration of electrically neutral single substitutional nitrogen atoms of ≲80 ppm, the so-called C or P1 centers, are irradiated with electrons at 10 MeV energy and low fluence. The results show a complete suppression of the irreversible behavior in field and temperature of the magnetization below 30 K, after a decrease in ≲40 ppm in the concentration of C centers produced by the electron irradiation. This result indicates that magnetic C centers are at the origin of the large hysteretic behavior found recently in nitrogen-doped diamond crystals. This is remarkable because of the relatively low density of C centers, stressing the extraordinary role of the C centers in triggering those phenomena in diamond at relatively high temperatures. After annealing the samples at high temperatures in vacuum, the hysteretic behavior is partially recovered