In der Dissertation wurde die Möglichkeit des gemeinsamen Recycling von Bleiglas und LCD-Glas zur Gewinnung der Hauptmetalle Blei und Indium (sowie weiterer Begleitmetalle) und die Erzeugung einer wirtschaftlich verwertbaren Glasphase untersucht. Durch die Anpassung der Glaszusammensetzung über die Zugabe von Soda und Kalk, die Einstellung der Arbeitstemperatur und die Untersuchung der prozesstechnischen Erfordernisse, wie die Trennung von Schmelzvorgang und Reduktion, konnte gezeigt werden, dass Blei zu über 98% und Indium zu über 80% aus den Schrotten gewonnen werden kann. Die erzeugte Glasphase ist durch Verdünnung mit Quarz und Feineinstellung der Zusammensetzung direkt verwendbar. Durch die Reduktion des Glases und die Kreislaufführung von zugeführtem Natriumoxid konnte gezeigt werden, dass sogar höherwertige Gläser hergestellt werden können. Die durchgeführte Wirtschaftlichkeitsbetrachtung der beiden Verfahrensalternativen bestätigte den ökonomischen Vorteil der Kreislaufführung.

Doctor of Philosophy / Department of Special Education, Counseling and Student Affairs / Kenneth F. Hughey / African American and Latino students continue to experience lower retention and higher attrition rates then their White counterparts. The aim of this qualitative interview study was to understand how African American and Latino students at a predominantly White institution (PWI) achieved graduation in Agriculture-STEM (A-STEM) disciplines. Based on the global need for more A-STEM and STEM professionals and the under-representation of African American and Latino students in the fields, there appeared to be a gap in the research on this population and success attributes with respect to completing undergraduate degrees. There was a tendency in the literature toward examining African American and Latino students utilizing the deficit model. This study explores the lived experiences of two African American and one Latino alumni of A-STEM programs. Understanding the life stories, via counter narratives, of these students may help universities develop stronger support for student success in college for not only African American and Latino students, but for all students in A-STEM disciplines. Critical Race Theory was the framework used for the analysis and the interpretation of the data in this study. The data consisted of interview transcripts, timeline, documents, photographs, and e-mail conversations. Communicating the findings in qualitative interview studies is the result of constructing the experiences and meanings of events through the eyes of the participants in a manner that portrays a representation of their experiences. Each participant’s counter narratives were created to highlight salient patterns reflected in their experiences. The writing around the participants’ experiences, and the interrogation of data allowed for the identification of patterns that were consistent with each participant’s stories and their individual unique details. The findings revealed: (a) ethnic minority students want faculty and administrators who looked like them because having someone to understand their experiences as people of color in PWI is needed; (b) the need for organizations that support ethnic minority student academic and social success, which in turn helps to create a sense of belongingness and a more inclusive campus climate; (c) more overall faculty support in and out of the classroom; and (d) opportunities for involvement in faculty-led research projects.

Heuristic estimates of probabilities may be an obstacle to decision making within High Reliability Organizations. Accident reports have found that two from each other separate phenomenon, Blame Culture and Type 1 processing constitutes a particularily serious threat to decision making. The present study (N = 70) investigated if a perceived risk of negative feedback and cognitive load would lead to more heuristic estimates on the Conjunction Fallacy. Three experiment conditions were included in the study: Negative feedback, cognitive load and control. The results were non-significant for both negative feedback and cognitive load. Furthermore, the estimated negative affect was higher when violations to the Conjunction Rule was made. Previous studies showing that high scores on the Cognitive Reflection Test (CRT) indicate less sensitivity to conjunction fallacies, were replicated. The present study concluded that the CRT may be a strong predictor of the Conjunction Fallacy.

For a long time, the scientific community underestimated the value of carbohydrates and the approach of most scientists to the complex world of glycans was apprehensive. The scenario, however, has changed today. With the development of new research tools and methodologies the study of carbohydrates and glycoconjugates has progressed rapidly, increasing our understanding of these molecules. Carbohydrates are most abundant amongst biological polymers in nature and vital for life processes. In their simplest form, they serve as a primary source of energy to most living organisms. In generalis, they exist as complex structures (glycans), and as conjugates of protein (glycoproteins, proteoglycans), lipids (glycolipids) and nucleosides (UDP-Glucose). Defined in the broadest sense, the study of glycans in all their forms and their interacting partners is termed “Glycobiology”. Glycans are ubiquitously found in nature decorating cells of almost all types with a “sugar coat”. They are also present within the cytoplasm, as well as in the extra-cellular matrix. They have key roles in a broad range of biological processes, including signal transduction, cell development and immune responses. All living organisms have evolved to express proteins that recognize discrete glycans and mediate specific physiological or pathological processes. One major class of such proteins is “Lectins”. Found in all forms of life, they are characterized by their ability to recognize carbohydrates. They are proteins of non-immune origin that bind glycans reversibly with a high degree of stereo-specificity in a non-catalytic manner. It must be emphasized that they are a different class from glycan-specific antibodies. Lectins were first discovered in plants and a large amount of work has been carried out on plant lectins to decipher their structural organization, mode of interaction with substrate and as models to study protein stability and folding. Study on animal and microbial lectins, on the other hand, gathered momentum only recently. In spite of this, more is known about their function in animals and micro-organisms rather than in plants. Lectin-glycan binding is implicated in several important biological processes such as protein folding, trafficking, host-pathogen interactions, immune cell responses and in malignancy and metastasis. Most lectins have one or more carbohydrate recognition domains (CRDs) which often share either 3-D structural features or amino acid sequence. New members of a family can be identified using either sequence or structural homology. Interestingly, it turns out that several plant and microbial lectins have structural or sequential similarity with animal lectins , revealing that these CRDs are evolutionarily related. This thesis, entitled “Structural, Biophysical and Biochemical Studies on Mannose-specific Lectins”, focuses on three lectins, Banana lectin (Banlec), Calreticulin (CRT) and Peptide-N-Glycanase (PNGase). Although all three lectins have distinct biological functions, they share a common ligand specificity at the monosaccharide level i.e. mannose. This thesis, besides characterizing these lectins, studies in detail, the difference in the mode of interaction with their ligands. Chapter 1 is a general introduction on lectins, glycan-lectin interactions and the various techniques that are employed to characterize these interactions. Several principles have emerged about the nature of glycan–lectin interactions. It has been observed that the binding sites for low molecular weight glycans are of relatively low affinity (Kd values in the high micromolar to low millimolar range). Selectivity is mostly achieved via a combination of hydrogen bonds and by van der Waals packing of the hydrophobic faces of monosaccharide rings against aromatic amino acid side chains. Further selectivity and enhanced affinity can be achieved by additional contacts between the glycan and the protein. It is notable that the actual region of contact between the saccharide and the polypeptide typically involves only one to three monosaccharide residues. As a consequence of all of the above, these lectin-binding sites tend to be of relatively low affinity, although they can exhibit high specificity. It is intriguing to observe that such low-affinity sites have the ability to mediate biologically relevant interactions. There are many different ways to study binding of glycans to proteins, and each approach has its advantages and disadvantages in terms of thermodynamic rigor, amounts of protein and glycan needed, and the speed of analysis. In examining these interactions, two broad categories of techniques are applied: (1) kinetic and near-equilibrium methods, such as titration calorimetry; and (2) non-equilibrium methods such as glycan microarray screening and ELISA-based approaches. Two of the most widely used biophysical approaches for examining glycan-lectin interactions at the molecular level are X-ray crystallography and nuclear magnetic resonance (NMR). However, as small molecules often co-crystallize with a lectin better than large molecules, a lot of our knowledge about glycan–lectin interactions at the atomic level is based on co-crystals of lectins with unnatural ligands. Thus, a great challenge exists in attempting to understand glycan–lectin interactions in the context of natural glycans present as glycoproteins, glycolipids, or proteoglycans. Chapter 2 introduces Banana lectin and describes the stability studies carried out. The unfolding pathway of Banlec was determined using GdnCl induced denaturation. Analysis of isothermal denaturation provided information on its conformational stability and the high values of ΔG of unfolding at various temperatures indicated the strength of inter-subunit interactions. It was found that Banlec is a very stable protein and denatures only at high chaotrope concentrations. The basis of the stability may be attributed to strong hydrogen bonds at the dimeric interface along with the presence of water bridges. This is a very unique example in proteins where subunit association is not a consequence of the predominance of hydrophobic interactions. High temperature molecular dynamics simulations have been utilized to monitor and understand early stages of thermally induced unfolding of Banlec. The present study investigates the behavior of the dimeric protein at four different temperatures. The process of unfolding was monitored by monitoring the radius of gyration, the rms deviation of each residue, change in relative solvent accessibility and the pattern of inter- and intra-subunit interactions. The overall study demonstrates that the Banlec dimer is a highly stable structure, the stability in most part contributed by interfacial interactions. The pattern of hydrogen bonding within the subunits and at the interface across different stages has been analyzed and has provided the rationale for its intrinsic high stability. In Chapter 3 the conformational and dynamic behaviour of three mannose containing oligosaccharides, a tetrasaccharide with α1→2, and α1→3, and a penta- and a heptasaccharide with α1→2, α1→3, and α1→6 linkages has been evaluated. Molecular mechanics, molecular dynamics simulations and NMR spectroscopy methods were used for evaluation. It is found that they display a fair amount of conformational freedom, with one major and one minor conformation per glycosidic linkage. The evaluation of their recognition by Banlec has been performed by STD NMR methods and a preliminary view of their putative interaction mode has been carried out by means of docking procedures. In Chapter 4 the conformational behaviour of three mannose containing oligosaccharides, namely, the α1→3[α1→6] trisaccharide, the heptasaccharide with α1→2, α1→3, and α1→6 linkages and the tetrasaccharide consisting of α1→3 and α1→2 linkages, when bound to Banlec has been evaluated by trNOE NMR methods and docking calculations. It is found that the molecular recognition event involves a conformational selection process, with only one of the conformations, among those available to the sugar in free state, being recognised at the lectin binding site. It is known that many proteins, including members of the Jacalin-related lectin family (of which Banlec is a member), bind the high-mannose saccharides found on the surface of the HIV-associated envelope glycoprotein, gp120, thus interfering with the viral life cycle, potentially providing a manner of controlling a variety of infections, including HIV. These proteins are thought to recognize the high-mannose type glycans with subtly different structures, although the precise specificities are yet to be clarified. This study was carried out to gain a better understanding of these protein-carbohydrate recognition events. Chapter 5 reports interactions of Calreticulin (CRT) with the trisaccharide Glcα1-3Manα1-2Man. Previously in our laboratory it was established using modeling studies the residues in CRT important for sugar binding. Here, the relative roles of Trp-319, Asp-317 and Asp-160 for sugar binding have been explored by using site-directed mutagenesis and isothermal titration calorimetry (ITC). Residues corresponding to Asp-160 and Asp-317 in calnexin (CNX) are known to play important roles in sugar binding. The present study demonstrates that Asp-160 is not involved in sugar binding, while Asp-317 plays a crucial role. Further, it is also validated that hydroxyl-pi interactions of the sugar with Trp-319 dictate sugar binding in CRT. This study defines further the binding site of CRT and also highlights its subtle differences with that of CNX. Additionally, mono-deoxy analogues of the trisaccharide unit Glcα1-3Manα1-2Man have been used to determine the role of various hydroxyl groups of the sugar substrate in sugar-CRT interactions. Using the thermodynamic data obtained by carrying out ITC of CRT with these analogues, it is demonstrated that the 3-OH group of Glc1 plays an important role in sugar-CRT binding, whereas the 6-OH group does not. Also, the 4-OH, 6-OH of Man2 and 3-OH, 4-OH of Man3 in the trisaccharide are involved in binding, of which 6-OH of Man2 and 4-OH of Man3 have a more significant role to play. Therefore, the interactions between the substrate sugar of glycoproteins and the lectin chaperone CRT are further delineated. Chapter 6 introduces Peptide-N-Glycanase (PNGase) and delineates the various interactions involved in the binding of oligomannose structures of glycoproteins to the C-terminal domain (the carbohydrate recognition module) of PNGase. ITC is used to characterize the interaction to oligosaccharides in terms of affinity, stoichiometry, enthalpy, entropy and heat capacity changes with the mouse PNGase C-terminal domain. Using the thermodynamic data obtained, it was determined that PNGase requires the tri-mannoside moiety of the native glycan on glycoproteins as the basic minimum entity for recognition and binding. Additional mannose moieties on the glycan do not significantly interact with PNGase and therefore no enhancement in binding affinity is observed (unlike CRT) which is in concordance with its role of stripping glycans from misfolded glycoproteins targeted for degradation via the ERAD (Endoplasmic reticulum assisted degradation) pathway. Chapter 7 briefly summarizes all the findings of the research carried out and presents a comparative analysis of the three lectins studied. Appendix A: Protein folding in the ER is assisted by molecular chaperones. Lectin chaperones such as CRT and CNX assist the folding of glycoproteins by their N-linked oligosaccharide chains. Dynamic processing of the original glycan chain of (GlcNAc)2(Man)9(Glc)3 to remove the terminal glucose moieties is essential for accurate folding. Proteins that attain their native conformation are then transported to the Golgi complex for further glycan modifications. In case of aberrant folding the proteins are retrotranslocated into the cytosol, ubiquitinated, deglycosylated and degraded by the proteasome. Peptide-N-glycanase is a cytosolic enzyme that releases N-glycans from glycoproteins and glycopeptides. PNGase is now widely recognized as a major participant in protein quality control machinery for ERAD or the proteasomal degradation of retrotranslocated glycoproteins. It is therefore desirable to synthesize fluorescently labeled glycoprotein substrates which will provide direct understanding of how, when and where, the interaction between the substrate and the enzyme occurs. Towards this goal, cloning of GFP and RFP tagged full length mouse and human PNGase and CRT was carried out which is described in this section.

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Recent research suggests that culturally responsive teaching (CRT) practices have the potential to increase student educational outcomes, as well as to reduce unnecessary or inappropriate placement referrals. Examination of the core components in CRT, teacher efficacy and cultural competence, is proposed to be a critical step to reduce unwarranted referrals of culturally and linguistically diverse students. However, there is limited empirical support for the relationship between CRT and instructional referrals, and even among existing studies there is inconsistency regarding the relation of these constructs. The purpose of this study is to examine teacher factors (i.e., teacher role, degree earned, years of teaching, ESL certification held, language proficiency and ethnicity) as a predictor of teacher competence, and the role these factors play in teachers’ referral decision making. To investigate these relationships, a national sample of elementary teachers (N = 258) completed a survey addressing their background, profession endorsements, sense of teaching efficiency, and the instructional decisions they would make in the scenarios presented. The results of this study revealed that teacher role (i.e., general, ESL or special educator) and ESL certification were important predictors of teacher competency. A statistically significant mean difference in teacher competency was found between teachers with and without ESL certification, indicating ESL certification as an important factor in deciding the level of teacher competency. Finally, teacher competency was found to improve teachers’ instructional decision making in scenarios in which the students displayed linguistic difficulties. The findings provide valuable insights to teacher training programs and other professional development entities regarding how to prepare educators to work more efficiently with ESL students.

La « haute-définition » a connu un essor important ces dernières années dans les domaines multimédia (télévision, jeux vidéo, etc.). Cependant, pour que l'observateur bénéficie pleinement de cette amélioration de la qualité d'usage, l'augmentation de la résolution spatiale des images affichées doit être accompagnée d'une augmentation de la taille de l'écran. Les écrans à tube cathodique (CRT), lourds et encombrants, ont donc progressivement laissé la place à de nouvelles technologies d'affichage, caractérisées par leur écran plat. Les écrans à cristaux liquides (LCD), leaders sur le marché des téléviseurs et des moniteurs informatiques, souffrent encore de nombreux défauts visuels notamment lors de l'affichage d'images animées. Durant ces travaux de thèse, nous avons choisi de nous intéresser plus particulièrement au flou de mouvement, dont les causes sont à la fois technologiques et perceptives. Nous avons tout d'abord caractérisé cet artefact visuel d'un point de vue métrologique, en développant une méthode de mesure basée sur la réponse indicielle temporelle des pixels de l'écran. Dans un second temps, nous avons mis en œuvre plusieurs expérimentations psychophysiques de manière à modéliser la perception du flou de mouvement sur LCD, et à caractériser la gêne associée à ce défaut. Ces mesures psychovisuelles ont permis d'établir des recommandations sur les caractéristiques temporelles des écrans LCD. Enfin, un modèle de flou de mouvement global, basé sur la caractérisation technique et perceptive de cet artefact, permet de prédire la perte de qualité mesurée subjectivement sur les écrans LCD. Les solutions technologiques de réduction du flou de mouvement peuvent alors être évaluées de manière automatique.

Submitted by Ana Paula Jelihovschi (anapgj@gmail.com) on 2017-04-06T23:50:28Z No. of bitstreams: 1 Dissertação Ana Paula Jelihovschi.pdf: 735331 bytes, checksum: d5037818c52a08c937e7a7b8c3199e0c (MD5) / Approved for entry into archive by ÁUREA CORRÊA DA FONSECA CORRÊA DA FONSECA (aurea.fonseca@fgv.br) on 2017-05-08T14:08:01Z (GMT) No. of bitstreams: 1 Dissertação Ana Paula Jelihovschi.pdf: 735331 bytes, checksum: d5037818c52a08c937e7a7b8c3199e0c (MD5) / Made available in DSpace on 2017-05-16T12:32:31Z (GMT). No. of bitstreams: 1 Dissertação Ana Paula Jelihovschi.pdf: 735331 bytes, checksum: d5037818c52a08c937e7a7b8c3199e0c (MD5) Previous issue date: 2016-10-19 / Impulsivity may lead to several unfortunate consequences and maladaptive behaviors for clinical and non-clinical people. Although many studies discuss the negative impact of it, few of them emphasize the relationship between cognitive impulsiveness and decision making in non-clinical subjects. The aim of this study is to investigate the effects of cognitive impulsiveness on decision making and explore the strategies used by participants to solve problems. For this purpose, we apply two measures of impulsivity: the self-report Barratt Impulsiveness Scale (BIS-11) and the performance based Cognitive Reflection Test (CRT).This is the first study that compares self-report impulsiveness based on BIS-11 and performance-based reflectivity measured by CRT. Moreover, due to the fact that we apply the instruments on pen and paper, it is possible to evaluate participants’ reasoning processes employed to answer CRT questions. These reasoning processes are related to the role of Executive Functions for decision making and its relationship with impulsiveness. In practical terms, we observed participants’ strategies by analyzing their calculation expressions and data organization to answer CRT questions in the paper sheet. The sample consists of 191 non-clinical adults, professionals, and undergraduate students from the fields of business, management, and accounting. Results show that cognitive impulsiveness may negatively affect performance. Moreover, there is no difference in strategies used by impulsive and non-impulsive people during a decision making, and who calculate in the paper sheet perform better. Finally, people who inhibit their immediate answers also perform better during a decision making.

Environment friendly products can be defined as products which show significant environmental improvements made at their most important life-cycle stages. For durable goods, life-cycle stages include manufacturing, use, and end-of-life of product. Reverse Supply Chain Management is the process of planning, implementing, and controlling the efficient, cost effective flow of raw materials, in-process inventory, finished goods and related information from the point of consumption to the point of origin for the purpose of recapturing value and/or proper disposal. The efficient and proper use of 5R’s processes namely Remanufacturing, Refurbishment, Reuse, Repair; and Recycle help the product to be greener and environment friendly. Part of the process also includes the proper disposal of goods which is essential for maintaining a green environment. This study aims at finding the significant factors to be considered by Cathode Ray Tube (CRT) Television component manufacturers to manufacture Environment Friendly Product. Various parameters like raw material procurement; water and energy consumption in product manufacturing; the extent of environmental regulations followed; waste production; and waste processing have been considered in this study. A Case Study has been prepared to study the entire manufacturing process of a CRT Television. The case study also looks at the regulations followed by CRT TV component manufacturers in India and how they are different from other countries. An attempt has been made to find out the value which can be recovered at the End-Of-Life of CRT TVs. The case also looks at safe recycling options for CRT TVs. The study shows that CRT TV component manufacturers consider Resource Procurement, Energy Utilization; and Compliance with Regulations to a significant extent. Also, an attempt has been made to develop an Environmental Friendly Index (EFI). The EFI depends on resource procurement, energy utilization, waste production, waste processing, and existence of environmental team in the company. There have been no steps taken by these component manufacturers towards dealing with return goods. All the return goods are dealt with by recyclers, who extract the material through unscientific and non-environmental friendly ways. The recyclers are not able to extract all the useful material, which if done in an efficient way, will result in more material recovery.