Solid state metathesis synthesis for ZnO-based materials towards applications in light-emitting diodes and ultra-violet-sensing devices

Solid state metathesis (SSM) has gained much attention for the synthesis of ZnObased semiconductors. SSM is a synthesis method that avoids organic solvents, high temperature calcination, and it is simple and fast. Co-doped ZnO has already been synthesized by several other methods (co-precipitation method, sol-gel). We wanted to use SSM to make Co-doped ZnO, in which Zn²⁺ ions are replaced by Co²⁺ ions. The thesis work goal was to prepare Co-doped ZnO to use it in light emitting diodes as a red light emitter. Raman spectra of the attempted Co-doped ZnO confirms the formation Co(OH)₂ as a secondary phase, which in turns converts into Co₃O₄ during high temperature calcination. There were no characteristic peaks in the visible region of UV-Vis spectra that would correspond to the emission of red light. Stoichiometric ZnO films are good candidates for use in various sensing devices. The frequency-dependent UV response of SSM-produced ZnO films were studied under AC conditions. After storing in the dark for several days, the UV responses were studied by electrochemical impedance spectroscopy (EIS). The resulting data allow determination, for each individual film, what range of frequencies are appropriate for use in UV sensing

Analysis, Modeling, and Algorithms for Scalable Web Crawling

This dissertation presents a modeling framework for the intermediate data generated by external-memory sorting algorithms (e.g., merge sort, bucket sort, hash sort, replacement selection) that are well-known, yet without accurate models of produced data volume. The motivation comes from the IRLbot crawl experience in June 2007, where a collection of scalable and high-performance external sorting methods are used to handle such problems as URL uniqueness checking, real-time frontier ranking, budget allocation, spam avoidance, all being monumental tasks, especially when limited to the resources of a single-machine. We discuss this crawl experience in detail, use novel algorithms to collect data from the crawl image, and then advance to a broader problem – sorting arbitrarily large-scale data using limited resources and accurately capturing the required cost (e.g., time and disk usage). To solve these problems, we present an accurate model of uniqueness probability the probability to encounter previous unseen data and use that to analyze the amount of intermediate data generated the above-mentioned sorting methods. We also demonstrate how the intermediate data volume and runtime vary based on the input properties (e.g., frequency distribution), hardware configuration (e.g., main memory size, CPU and disk speed) and the choice of sorting method, and that our proposed models accurately capture such variation. Furthermore, we propose a novel hash-based method for replacement selection sort and its model in case of duplicate data, where existing literature is limited to random or mostly-unique data. Note that the classic replacement selection method has the ability to increase the length of sorted runs and reduce their number, both directly benefiting the merge step of external sorting and . But because of a priority queue-assisted sort operation that is inherently slow, the application of replacement selection was limited. Our hash-based design solves this problem by making the sort phase significantly faster compared to existing methods, making this method a preferred choice. The presented models also enable exact analysis of Least-Recently-Used (LRU) and Random Replacement caches (i.e., their hit rate) that are used as part of the algorithms presented here. These cache models are more accurate than the ones in existing literature, since the existing ones mostly assume infinite stream of data, while our models work accurately on finite streams (e.g., sampled web graphs, click stream) as well. In addition, we present accurate models for various crawl characteristics of random graphs, which can forecast a number of aspects of crawl experience based on the graph properties (e.g., degree distribution). All these models are presented under a unified umbrella to analyze a set of large-scale information processing algorithms that are streamlined for high performance and scalability

Modeling randomized data streams in caching, data processing, and crawling applications

caching, search in large graphs) process streams of random key-value records that follow highly skewed frequency distributions. In this work, we first develop stochastic models for the probability to encounter unique keys during exploration of such streams and their growth rate over time. We then apply these models to the analysis of LRU caching, MapReduce overhead, and various crawl properties (e.g., node-degree bias, frontier size) in random graphs. I

Exploratory Qualitative Study to Understand the Underlying Motivations and Strategies of the Private For-Profit Healthcare Sector in Urban Bangladesh

Objectives This paper explores the underlying motivations and strategies of formal small and medium-sized formal private for-profit sector hospitals and clinics in urban Bangladesh and their implications for quality and access. Methods This exploratory qualitative study was conducted in Dhaka, Sylhet and Khulna City Corporations. Data collection methods included key informant interviews (20) with government and private sector leaders, in-depth interviews (30) with clinic owners, managers and providers and exit interviews (30) with healthcare clients. Results Profit generation is a driving force behind entry into the private healthcare business and the provision of services. However, non-financial motivations are also emphasised such as aspirations to serve the disadvantaged, personal ambition, desire for greater social status, obligations to continue family business and adverse family events. The discussion of private sector motivations and strategies is framed using the Business Policy Model. This model is comprised of three components: products and services, and efforts to make these attractive including patient-friendly discounts and service-packages, and building ‘good’ doctor-patient relationships; the market environment, cultivated using medical brokers and referral fees to bring in fresh clientele, and receipt of pharmaceutical incentives; and finally, organisational capabilities, in this case overcoming human resource shortages by relying on medical staff from the public sector, consultant specialists, on-call and less experienced doctors in training, unqualified nursing staff and referring complicated cases to public facilities. Conclusions In the context of low public sector capacity and growing healthcare demands in urban Bangladesh, private for-profit engagement is critical to achieving universal health coverage (UHC). Given the informality of the sector, the nascent state of healthcare financing, and a weak regulatory framework, the process of engagement must be gradual. Further research is needed to explore how engagement in UHC can be enabled while maintaining profitability. Incentives that support private sector efforts to improve quality, affordability and accountability are a first step in building this relationship

Antinociceptive and Antioxidant Activity of Zanthoxylum budrunga

Different parts of the medicinal plant Zanthoxylum budrunga Wall enjoy a variety of uses in ethnobotanical practice in Bangladesh. In the present study, a number of phytochemical and pharmacological investigations were done on the ethanol extract of Z. budrunga seeds (ZBSE) to evaluate its antinociceptive and antioxidant potential. ZBSE was also subjected to HPLC analysis to detect the presence of some common antioxidants. In acetic acid induced writhing test in mice, ZBSE showed 65.28 and 74.30% inhibition of writhing at the doses of 250 and 500 mg/kg and the results were statistically significant (P<0.001). In hot-plate test, ZBSE raised the pain threshold significantly (P<0.001) throughout the entire observation period. In DPPH scavenging assay, the IC50 of ZBSE was observed at 82.60 μg/mL. The phenolic content was found to be 338.77 mg GAE/100 g of dried plant material. In reducing power assay, ZBSE showed a concentration dependent reducing ability. HPLC analysis indicated the presence of caffeic acid with a concentration of 75.45 mg/100 g ZBSE. Present investigation supported the use of Zanthoxylum budrunga seed in traditional medicine for pain management. Constituents including caffeic acid and other phenolics might have some role in the observed activity

Mutant U2AF1-induced alternative splicing of H2afy (macroH2A1) regulates B-lymphopoiesis in mice

Somatic mutations in spliceosome genes are found in ∼50% of patients with myelodysplastic syndromes (MDS), a myeloid malignancy associated with low blood counts. Expression of the mutant splicing factor U2AF1(S34F) alters hematopoiesis and mRNA splicing in mice. Our understanding of the functionally relevant alternatively spliced target genes that cause hematopoietic phenotypes in vivo remains incomplete. Here, we demonstrate that reduced expression of H2afy1.1, an alternatively spliced isoform of the histone H2A variant gene H2afy, is responsible for reduced B cells in U2AF1(S34F) mice. Deletion of H2afy or expression of U2AF1(S34F) reduces expression of Ebf1 (early B cell factor 1), a key transcription factor for B cell development, and mechanistically, H2AFY is enriched at the EBF1 promoter. Induced expression of H2AFY1.1 in U2AF1(S34F) cells rescues reduced EBF1 expression and B cells numbers in vivo. Collectively, our data implicate alternative splicing of H2AFY as a contributor to lymphopenia induced by U2AF1(S34F) in mice and MDS

ゾウケツセイ ナイヒ サイボウ ニ オケル ニブンカ ノウ ノ CXCR4 シグナル ニ ヨル チョウセツ

熊本大

Confusion, Misjudgment and Dissonance: The Fall of a Priest, a People and a God in Chinua Achebe’s Arrow of God

Chinua Achebe’s Arrow of God portrays the gradual downfall and the ultimate doom of the protagonist, Ezeulu, of the entire Igbo community and even their deity, Ulu. Ezeulu’s tragedy happens in numerous stages influenced by various factors stemming from personal, communal and religious conflicts and his misinterpretation or misunderstanding of himself, his people, his deity and institutions and circumstances. Set in the 1920s Nigeria, Arrow of God portrays a period when colonial machination is well underway, and the native beliefs and institutions are crumbling under its grueling pressure. This paper seeks to show how Arrow of God shows that the main reason for the debacle of Igbo society lies in their internal conflicts, failure to stick to their tradition and the helplessness and dilemma to which colonialism has subjected them. Achebe asserts that for the sake of maintaining age-old traditions, some flexibility in judgment must be there, and any kind of absolutism should be avoided for the greater interest of the people

ゾウケツセイ ナイヒ サイボウ ニ オケル ニブンカ ノウ ノ CXCR4 シグナル ニ ヨル チョウセツ

博士（医学）熊本大