Bravo/Nr-CAM Is Closely Related to the Cell Adhesion Molecules L1 and Ng-CAM and Has a Similar Heterodimer Structure

Diverse cell-surface molecules of the nervous system play an important role in specifying cell interactions during development. Using a method designed to generate mAbs against neural surface molecules of defined molecular weight, we have previously reported on the surface protein, Bravo, found in the developing avian retinotectal system. Bravo is immunologically detected on developing optic fibers in the retina, but absent from distal regions of the same fibers in the tectum. We have isolated cDNA clones encompassing the entire coding region of Bravo, including clones containing five alternative sequences of cDNA. These putative alternatively spliced sequences encode stretches of polypeptide ranging in length from 10-93 amino acids and are predicted to be both extra- and intracellular. The deduced primary structure of Bravo reveals that, like the cell adhesion molecules (CAMs) chicken Ng- CAM and mouse L1, Bravo is composed of six Ig-like domains, five fibronectin type III repeats, a transmembrane domain, and a short cytoplasmic region. Recently, the cDNA sequence of a related molecule, Nr-CAM, was reported and its possible identity with Bravo discussed (Grumet, M., V. Mauro, M. P. Burgoon, G. E. Edelman, and B. A. Cunningham. 1991. J. Cell Biol. 113:1399-1412). Here we confirm this identity and moreover show that Bravo is found on Muller glial processes and end-feet in the developing retina. In contrast to the single polypeptide chain structure of Nr-CAM reported previously, we show that Bravo has a heterodimer structure composed of an alpha chain of M(r) 140/130 and a beta chain of 60-80 kD. As with L1 and Ng-CAM, the two chains of Bravo are generated from an intact polypeptide by cleavage at identical locations and conserved sites within all three molecules (Ser-Arg/Lys-Arg). The similar domain composition and heterodimer structure, as well as the 40% amino acid sequence identity of these molecules, defines them as an evolutionarily related subgroup of CAMs. The relationship of Bravo to molecules known to be involved in cell adhesion and process outgrowth, combined with its pattern of expression and numerous potential isoforms, suggests a complex role for this molecule in cell interactions during neural development

Politics of education, conflict and conflict resolution in Balochistan, Pakistan

Balochistan is one of the federating units (provinces) of Pakistan; it constitutes 44 % of Pakistan’s total territory and has been in a state of confrontation with the state since 1948. This is because the majority of the Baloch consider that the Pakistani state annexed their land forcibly, against the will and desire of the people. The Baloch nationalists have never accepted this annexation, and as a result the state has been facing serious crises precipitated by various factors. Ever since Pakistan’s annexation of Balochistan, there has been an on-going conflict between the Baloch (i.e., the Baloch people) and the state of Pakistan. The fact is that the conflict in Balochistan is multidimensional, including political, social and economic factors, the avarice of the Pakistani state and the grievances of the Baloch people. In order to aid an understanding of the various backgrounds to the conflict, this thesis contributes to debates on the politics of education and conflict in Pakistan’s Balochistan. I have used statistics and analysed data gathered during my fieldwork in Balochistan and Pakistan to investigate the politics of education and examine various policy frameworks, rationales and perspectives on the role of education. In order to do so, this study adopts a qualitative method and employs multiple data sources: documentary data, semi-structured interviews with twenty-eight stakeholders (in the province and country), visual data, and observations. Drawing on functionalist and conflict perspectives on the role of education, this thesis examines whether education in Balochistan is designed to empower the people or is simply used as a tool to control them. I have found that the state is not willing to educate the Baloch people; rather, it wishes to control them. There are two ways in which education in Balochistan is being used to serve the purpose of control. Firstly, the state of education in terms of its type, quality, quantity and infrastructure is considered by the majority of Baloch to be a failure of government’s strategic policy. For instance, education in Balochistan has lagged behind in various areas of government policy and decision-making. Major problems in Balochistan’s educational system include a deeply inadequate supply of textbooks, insufficient monitoring of schools, shortages of teachers and schools for both boys and girls, and insufficient funding. Secondly, many Baloch decry Pakistan’s unjust efforts to impose its culture, language and radical religious ideologies on the Baloch people. Indeed, the politics of (mis)representation of the Baloch and their history, culture and language are implemented through the state’s official textbooks. Education in Balochistan, particularly in government-run schools, is highly biased against the Baloch culture, history and social set-up, and it is thus a contributory factor in the generation of retaliatory behaviour among Baloch students. Formal education in Balochistan is structured in ways that indoctrinate children with a different language, culture and history. To many scholars, controlling education negates Baloch national aspirations and thus contributes to the conflict in Balochistan

Strain Hardening Behavior of Engineered Geopolymer Composites: Effects of the Activator Combination

Fly ash-based engineered geopolymer composites (EGCs) exhibiting strain hardening behavior under uni-axial tension were developed employing two different sodium-based (Na-based) and potassium-based (K-based) activator combinations. The relatively brittle low calcium (Class F) fly ash-based geopolymer matrix was reinforced with randomly oriented short poly vinyl alcohol (PVA) fibers (2% v/v). Na-based activator combination was composed of 8.0 M NaOH solution (28.6% w/w) and Na2SiO3 solution (71.4% w/w) with a SiO2/Na2O ratio of 2.0; whereas, Kbased activator combination was composed of 8.0 M KOH solution (28.6% w/w) and K2SiO3 solution (71.4% w/w) with a SiO2/K2O ratio of 2.23. The matrix and composite properties of the developed fly ash-based EGCs including workability of the fresh matrix, density, compressive strength and uni-axial tensile behavior were evaluated. The experimental results revealed that the sodium-based EGC (EGC-Na) exhibited superior tensile strain capacity, compressive and uni-axial tensile strengths with significantly enhanced ductility

Effect of dry heat on germination and viability of Cryptostegia grandiflora seeds

The present study described the effect of six dry heat intensities (28, 40, 60, 80, 100, and 200°C) and eight heat durations (0.5, 1, 2, 3, 6, 12, 24, and 36 min) on germination, viability, and germination rate of one-year-old seeds of the invasive weed rubber vine (Cryptostegia grandiflora R.Br.). Heat induced seed mortality is of significance to land managers, especially in pastoral areas, where prescribed burning is used to control rubber vine. There was a highly significant interaction between heat intensity and heat duration on germination, viability and germination rate of rubber vine seed. Seed germination was reduced once temperatures reached 80°C for more than 24 min. Raising the temperature to 100°C completely inhibited germination at 6 min and induced a total kill of seeds at 24 min. Further increases in dry heat to 200°C advanced inhibition of germination to 1 min and induced total kill of seeds at 3 min. Germination rate at 80, 100, and 200°C slowed down by 42, 65 and 91% of the original rate respectively. Above 80°C a negative correlation was detected between (i) germination response and heat duration, (ii) seed viability and heat duration, and (iii) germination rate and heat duration whereas seed viability was positively correlated with seed germination. The apparent tolerance to high temperature in rubber vine seeds indicates that high-intensity fires may be a requirement for maintenance of an effective seed management strategy in rubber vine infested habitats

Διευρύνοντας το Μεθοδολογικό πλάισιο των Ολοκληρωμένων Μοντέλων Χρήσεων-Γης και Μεταφορών: Χωρικά Οικονομετρικά Μοντέλα και Αξιολόγηση Πολιτικών

323 σ.Στην παρούσα εργασία εξετάζεται η διεύρυνση του μεθοδολογικού πλαισίου των Όλοκληρωμένων Μοντέλων Χρήσεων-Γης και Μεταφορών σε κάθε επίπεδο. Οι προτεινόμενες βελτιώσεις αποσκοπούν στην αύξηση των ικανοτήτων πρόβλεψης, αξιοποιώντας τα οφέλη της μικροπροσομοίωσης σε τρείς διαστάσεις, άτομο, χώρο και χρόνο, με σκοπό να καταστόύν τα μοντέλα αυτά ευέλικτα εργαλεία αξιολοόγησης πολιτικών.In this research, the methodological framework of the Integrated Land-Use and Transport (LUTI) models is extended at every level. The objective of developing and implementing LUTI models is to predict the direct and indirect impacts of –transport and land-use– policies, on the environment, the society and the economy. The proposed improvements aim to increase the predicting capabilities of the current LUTI models, exploiting the strengths of microsimulation in three dimensions, agents, space and time, in order to render them flexible platforms for policy evaluation. The effects of the current economic crisis are discussed and explored throughout the doctoral dissertation. Aiming to decrease the required budget for a LUTI model development, public on-line data are used to a large part of the analysis. Moreover, a graph-theoretic solution for associations generation in synthetic simulation is suggested. Different types of spatial econometric models are used for the development of real estate price models, which form fundamental component of every LUTI model. Urban quality indicators (i.e. accessibility, population segregation, economic viability, available open space, housing affordability, land-use and social mix, and building density) are effectively employed manifesting the benefits of trans-disciplinary collaboration in urban planning. In this research, a policy evaluation methodology based on distributions rather than single aggregate measures of quality indicators is proposed. The results indicate that spatial econometrics effectively remove the spatial autocorrelation and achieve higher accuracy than the traditional linear regression, in predicting the dwelling prices. The impact of transportation infrastructure locations on real estate purchase prices and rents differs, depending on the type of the transit system. Qualitative transit infrastructure has preserved the real estate prices at higher levels during the crisis. Synthetic populations and real, on-line, crowdsourced data can efficiently be used for the development of LUTI models. Finally, agent-based LUTI models provide an opportunity for the development of an improved, flexible policy evaluation platform.Δημήτριος Β. Ευθυμίο