The study of silicates and refractory materials at high pressures and temperatures

To better understand high pressure behavior of solids, both silicates and oxides have been investigated to clarify the high pressure melting, phase transformations and thermal parameters as well as their size dependences, both theoretically and experimentally. ^ To judge the precision of data determined experimentally, the reliabilities of different high pressure techniques have been discussed. A thermodynamic model has been developed and demonstrated to be able to closely reproduce the melting of solids by comparison between results calculated and data obtained experimentally, including metals (Al, Ni and Pt), Silicates (Mg3Al 2Si3O12 and CaMgSi2O6), Halides (NaCl, CsCl and LiF) and Oxides (MgO, FeO and Al2O3). The melting data obtained have been discussed to address the dynamics of the Earth's interior. ^ Results obtained with Raman spectroscopy and x-ray diffraction show that solids including silicates (andradite and pyrope) and oxides (CeO2 and TiO2) undergo a series of pressure-induced phase transformations. The effects of particle size under high pressures have been investigated. The results obtained indicate that the reduction of particle size leads to the enhancement of the bulk modulus and a significant decrease of transition pressure in TiO2 (rutile) and CeO2. The pressure-induced amorphization in anatase also results from the size effects. ^ Combining the data obtained with global seismic tomography, the physics and chemistry of the Earth's mantle and the dynamics of the core-mantle interaction have been discussed. The high pressure phases of Al3+- and Fe3+-bearing minerals play important roles in the dynamics of the lower mantle. ^

The Butter was Better: A Preliminary Study of Nostalgia and Cuban American Identity

Nostalgia for pre-Communist Cuba was found to have an important influence on the identity of three American born Cuban Americans.

A Mixed Method Study of Spirituality and the Influence on TB Medication Adherence

Nonadherence to medication for tuberculosis (TB) can lead to new cases of TB and death. Interest in spirituality in healthcare has grown among adult educators, health educators and healthcare workers (Tisdell, 2003). This mixed-method study will explore spirituality and TB medication adherence among African American and Haitian populations.

A Case-Only Genome-wide Association Study of Gender- and Age-specific Risk Markers for Childhood Leukemia

Males and age group 1 to 5 years show a much higher risk for childhood acute lymphoblastic leukemia (ALL). We performed a case-only genome-wide association study (GWAS), using the Illumina Infinium HumanCoreExome Chip, to unmask gender- and age-specific risk variants in 240 non-Hispanic white children with ALL recruited at Texas Children’s Cancer Center, Houston, Texas. Besides statistically most significant results, we also considered results that yielded the highest effect sizes. Existing experimental data and bioinformatic predictions were used to complement results, and to examine the biological significance of statistical results. Our study identified novel risk variants for childhood ALL. The SNP, rs4813720 (RASSF2), showed the statistically most significant gender-specific associations (P < 2 x 10-6). Likewise, rs10505918 (SOX5) yielded the lowest P value (P < 1 x 10-5) for age-specific associations, and also showed the statistically most significant association with age-at-onset (P < 1 x 10-4). Two SNPs, rs12722042 and 12722039, from the HLA-DQA1 region yielded the highest effect sizes (odds ratio (OR) = 15.7; P = 0.002) for gender-specific results, and the SNP, rs17109582 (OR = 12.5; P = 0.006), showed the highest effect size for age-specific results. Sex chromosome variants did not appear to be involved in gender-specific associations. The HLA-DQA1 SNPs belong to DQA1*01:07and confirmed previously reported male-specific association with DQA1*01:07. Twenty one of the SNPs identified as risk markers for gender- or age-specific associations were located in the transcription factor binding sites and 56 SNPs were non-synonymous variants, likely to alter protein function. Although bioinformatic analysis did not implicate a particular mechanism for gender- and age-specific associations, RASSF2 has an estrogen receptor-alpha binding site in its promoter. The unknown mechanisms may be due to lack of interest in gender- and age-specificity in associations. These results provide a foundation for further studies to examine the gender- and age-differential in childhood ALL risk. Following replication and mechanistic studies, risk factors for one gender or age group may have a potential to be used as biomarkers for targeted intervention for prevention and maybe also for treatment.

World coffee markets and national coffee parastatals since 1989: a comparative study of Colombia and Cote D'ivoire

The International Coffee Agreements (ICA) involved the majority of nations producing and consuming coffee and provided relative economic stability to the coffee sectors of the exporting Third World countries. This study focuses on the serious impact of the 1989 collapse of the ICA on the domestic coffee sectors of Colombia and Cote d'Ivoire. In particular, the dissertation examines the role of the Colombian and Ivoirian coffee parastatals, the Federacion Nacional de Cafeteros de Colombia and the Caisse de Stabilisation et Soutien des Prix des Produits Agricoles, during the crisis and their transformation by it. The theoretical framework employed in this study is borrowed from the literature on state-society relations. The methodology includes: in-depth analysis of the historical roles of the parastatal agencies in coffee production, state-society relations and economic development in Colombia and Côte d'Ivoire; interviews with parastatal administrators, producers and other knowledgeable informants in both countries; and a comprehensive review of newspaper articles and official statements of coffee policy published in Colombia and Côte d'Ivoire prior to, during, and after the crisis. The Colombian and Ivoirian coffee sectors and their producers faced serious economic and social problems following the drop in coffee prices. The coffee parastatals in Colombia and Côte d'Ivoire first lost some of their responsibilities following the world coffee crisis. The Caisse was in the end eliminated while FEDECAFE struggled to remain in existence. Along the way, both entities faced protests from disgruntled coffee producers, who organized politically for the first time in their nations' histories. I argue that the outcome for the parastatals depended in part on the conditions of their formation, particularly the level of societal involvement in their creation. I also posit that the country's dependence on foreign aid played a key role in the fate of the parastatals. This dissertation concludes that developments in the Colombian and Ivoirian coffee sectors have significantly contributed to the creation of the difficult political and economic conditions of both countries today.

Design construction and testing of a heat loop for study of fouling and its interrelationship to corrosion in heat exchanger tubes

A heat loop suitable for the study of thermal fouling and its relationship to corrosion processes was designed, constructed and tested. The design adopted was an improvement over those used by such investigators as Hopkins and the Heat Transfer Research Institute in that very low levels of fouling could be detected accurately, the heat transfer surface could be readily removed for examination and the chemistry of the environment could be carefully monitored and controlled. In addition, an indirect method of electrical heating of the heat transfer surface was employed to eliminate magnetic and electric effects which result when direct resistance heating is employed to a test section. The testing of the loop was done using a 316 stainless steel test section and a suspension of ferric oxide and water in an attempt to duplicate the results obtained by Hopkins. Two types of thermal ·fouling resistance versus time curves were obtained . (i) Asymptotic type fouling curve, similar to the fouling behaviour described by Kern and Seaton and other investigators, was the most frequent type of fouling curve obtained. Thermal fouling occurred at a steadily decreasing rate before reaching a final asymptotic value. (ii) If an asymptotically fouled tube was cooled with rapid cir- ·culation for periods up to eight hours at zero heat flux, and heating restarted, fouling recommenced at a high linear rate. The fouling results obtained were observed to be similar and 1n agreement with the fouling behaviour reported previously by Hopkins and it was possible to duplicate quite closely the previous results . This supports the contention of Hopkins that the fouling results obtained were due to a crevice corrosion process and not an artifact of that heat loop which might have caused electrical and magnetic effects influencing the fouling. The effects of Reynolds number and heat flux on the asymptotic fouling resistance have been determined. A single experiment to study the effect of oxygen concentration has been carried out. The ferric oxide concentration for most of the fouling trials was standardized at 2400 ppM and the range of Reynolds number and heat flux for the study was 11000-29500 and 89-121 KW/M², respectively.

Functional study of ephrins and eph receptors in the immune system

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.

Functional study of ephrins and eph receptors in the immune system

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.

A Market Study of Organic and Fair Trade Coffee in Bolivia

The purpose of this research is to study the commercialization of Fairtrade and Organic coffee in the Bolivia. Fairtrade and Organic coffee are alternative trade systems designed to promote the equitable and environmentally sustainable production of coffee. However, these alternative trading systems often fail to meet these goals. The producers and environment these systems are intended to protect remain marginalized. These failures are due to a number of local institutions. In order to better understand these institutions, this research conducted interviews of various stakeholders including producers, cooperative leaders, organic/Fair Trade certifiers, government agencies and private buyers. All these stakeholders influence the success of the alternative trade systems. By better understanding how these stakeholders impact the commercialization of coffee in Bolivia; new policies can be develop to improve the outcomes of alternative trade, to benefit both producers and the environment. This is especially critical in Bolivia because of the environmentally sensitive area in which coffee is grown, the potentially damaging impact of coca on the region and, the devastating economic impact to farmers.

Research in information systems: A study of diversity and inter-disciplinary discourse in the AIS basket journals between 1995 and 2011

The paper investigates how Information Systems (IS) has emerged as the product of inter-disciplinary discourses. The research aim in this study is to better understand diversity in IS research, and the extent to which the diversity of discourse expanded and contracted from 1995 to 2011. Methodologically, we apply a combined citations/co-citations analysis based on the eight Association for Information Systems basket journals and the 22 subject-field classification framework provided by the Association of Business Schools. Our findings suggest that IS is in a state of continuous interaction and competition with other disciplines. General Management was reduced from a dominant position as a reference discipline in IS at the expense of a growing variety of other discourses including Business Strategy, Marketing, and Ethics and Governance, among others. Over time, IS as a field moved from the periphery to a central position during its discursive formation. This supports the notion of IS as a fluid discipline dynamically embracing a diverse range of adjacent reference disciplines, while keeping a degree of continuing interaction with them. Understanding where IS is currently at allows us to better understand and propose fruitful avenues for its development in both academia and practice. © 2013 JIT Palgrave Macmillan All rights reserved.

Ultrastructural and Histological Study of Oogenesis and Oocyte Degeneration in the PenshellAtrina maura(Bivalvia: Pinnidae)

The successive stages of oogenesis and the changes involved in the oocyte degeneration process in the penshell Atrina maura were examined using light and transmission electron microscopy. The ovarian maturation process is asynchronous, as oocytes at different developmental stages can be found simultaneously. Oocytes develop from oogonia and then undergo three distinct stages of oogenesis: previtellogenesis, vitellogenesis and postvitellogenesis with mature oocytes. Atrina maura displays a solitary oogenesis type, in which follicular cells become associated with oocytes from the earliest stages of development and seem to play an integral role in vitellogenesis. The cytoplasm of vitellogenic oocytes contains numerous whorls of rough endoplasmic reticulum and Golgi bodies, suggesting that auto-synthetic vitellogenesis may occur in this species. In addition, the degeneration process of postvitellogenic oocytes triggered by a seasonal increase in water temperature (> 25°C) is described.

Ultrastructural and Histological Study of Oogenesis and Oocyte Degeneration in the PenshellAtrina maura(Bivalvia: Pinnidae)

The successive stages of oogenesis and the changes involved in the oocyte degeneration process in the penshell Atrina maura were examined using light and transmission electron microscopy. The ovarian maturation process is asynchronous, as oocytes at different developmental stages can be found simultaneously. Oocytes develop from oogonia and then undergo three distinct stages of oogenesis: previtellogenesis, vitellogenesis and postvitellogenesis with mature oocytes. Atrina maura displays a solitary oogenesis type, in which follicular cells become associated with oocytes from the earliest stages of development and seem to play an integral role in vitellogenesis. The cytoplasm of vitellogenic oocytes contains numerous whorls of rough endoplasmic reticulum and Golgi bodies, suggesting that auto-synthetic vitellogenesis may occur in this species. In addition, the degeneration process of postvitellogenic oocytes triggered by a seasonal increase in water temperature (> 25°C) is described.

Project Pró-Natal: population-based study of perinatal and infant mortality in Natal, Northeast Brazil

RAMOS, Ana Maria de Oliveira et al. Project Pró-Natal: population-based study of perinatal and infant mortality in Natal, Northeast Brazil. Pediatric and Developmental Pathology, v.3, n.1, p.29-35, 2000

Comparative study of hematologic and plasma biochemical variables in Eastern Atlantic juvenile and adult nesting loggerhead sea turtles (Caretta caretta).

[EN] Background: Plasma biochemical and hematologic variables are important in the management of endangered sea turtles, such as loggerheads. However, studies on blood biochemistry and hematology of loggerheads are limited, and different concentrations according to variable criteria have been reported. Objective: The purpose of this study was to establish and compare baseline plasma chemistry and hematology values in Eastern Atlantic juvenile and adult nesting loggerhead sea turtles (Caretta caretta).