175 research outputs found
Chitinozoan Biodiversity in the Ordovician of Gondwana: An Interval-Free Approach Using the Quantitative Stratigraphic Correlation Program CONOP9
The purpose of this study is to examine the biodiversity patterns of a group of fossil organisms called chitinozoans. Chitinozoans are organic-walled, planktonic microfossils that first appear in the Early Ordovician Period (488 million years ago) and diversify rapidly through the Paleozoic Era. The Ordovician Period was a time of great global climate change, and by studying this group of fossil plankton, we hope to better understand how modern plankton, which are the base of the marine food chain, might respond to climate change. We used a method called constrained optimization (CONOP9) to construct a composite range chart of 152 chitinozoan species from 65 Ordovician drill cores and outcrops from the paleocontinent Gondwana. Our results show that chitinozoan biodiversity increases throughout the Early and Middle Ordovician, peaks in the middle part of the Late Ordovician and declines thereafter. These results differ from biodiversity estimates derived from more traditional species counting methods
An Analysis of Uncertainty for Dose Estimation through the γ-H2AX Assay
Currently, the primary biomarker for radiation biodosimetry is the dicentric chromosome. However, the γ-H2AX histone is an alternative assay that is less labour-intensive. Blood samples can be taken more quickly than for the dicentric biomarker, and a larger number of samples can be handled within a given time frame. In this thesis, we discuss several statistical techniques for how to handle scored γ-H2AX foci data. We then apply these techniques to two datasets from Public Health England, using one to demonstrate techniques, and the second to check that the dose-response curve calculation and dose estimation techniques work. Throughout we choose to fit quasi-Poisson models instead of Poisson ones to account for overdispersion present within the foci count data. After fitting both linear and quadratic dose-response curves we create controls to validate the curves, using a reference sampling ratio to scale them if necessary. By calculating the uncertainty we show why linear fits are preferable to quadratic ones. We finally compare our linear dose-response curves from both datasets for multiple timepoints with pre-existing ones from the literature to see how they compare and what conclusions can be drawn about dose-response curves for this assay in general
Assessment practices in higher education: The experiences of newly appointed academics in professional fields from a phenomenological perspective
For a novice academic, the first experience of marking can be as memorable as preparing for and giving their first teaching session. Yet, while academic reflections and narratives abound for the latter, there is a paucity of literature regarding the former. This study begins to address this lack of literature through an exploration of the experiences of six newly appointed academics as they begin to mark students’ coursework. In choosing interpretive phenomenology as the methodological and philosophical influences for this study, I committed to an approach which required a search for an ontological understanding of being involved in marking as a new academic, rather than an understanding of what is known about marking. Each participant’s experience is illustrated through extracts from interviews that reflect rich descriptions of actions, behaviours and intentions, with the objective of evoking a ‘phenomenological nod’ that might resonate with others. Towards the end of the first year each participant reflected on the challenges in relation to their experience of unanticipated emotional effects and ethical considerations. Confidence, processes, accountability and responsibility and judgements emerged from the data as common themes. The concept of being-in-the-world-of-marking demonstrates conceptually the experiences of the newly appointed academics as they began to come to know themselves as markers and academics; not through the learning of facts about marking, but through their understanding and self-interpretation of their own and others’ marking practices. The experiences shared throughout the thesis support and further develop previous research findings, highlighting the need for additional training and guidance in relation to assessment and feedback within higher education, and reinforcing the necessity for newly appointed academics to be offered formal and informal mentorship and guidance in the theory and practice of assessment
Effects of tall fescue and lactate dehydrogenase genetic polymorphisms on dairy heifer growth and immune function
Objectives of this project were to evaluate polymorphisms in upstream elements of the lactate dehydrogenase B (LDHB) gene in crossbred dairy heifers (n = 27) and their effects on immune function and heifer growth when grazing endophyte-infected tall fescue. Two cultivars of tall fescue were utilized: Kentucky 31 (KY31), a wild-type endophyte-infected tall fescue, and HiMag 4 (HiMag), a domesticated non-toxic endophyte-infected tall fescue. Crossbred dairy heifers (Holstein × Jersey) were stratified by weight and randomly allotted to forage. The LDHB gene codes for one subunit of lactate dehydrogenase (LDH), an enzyme that catalyzes pyruvate to lactate and back to pyruvate. Forward primer used for amplification was 5’-ACACACCAGCAGCATCTCAG-3’ and reverse primer was 5’- GATAAGGGCTGCACGAAGAC-3’. The amplicon size for this LDHB primer set was 457 base pairs. Sequenced amplicons were aligned with Clustal2W for polymorphism detection and genotype assignment. Heifers that had a heterozygous genotype and grazed HiMag were heavier when compared with other heifer groups. Number of red blood cells and hemoglobin concentrations for heifers grazing KY31 were greater when compared to heifers grazing HiMag. Distribution of white blood cells was affected by LDHB genotype. Two dairy heifer management tools, stockpiled tall fescue and LDHB genotyping, were assessed in this study, both of which impacted heifer growth and immune function as assessed by blood cell differentials
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Perception of Foreign Accented Speech: the Roles of Familiarity and Linguistic Training
This paper seeks to address the issue by examining two factors that potentially affect a listener’s perception of foreign accented speech: degree of familiarity (as acquired through a work or personal environment) and amount of ESL or linguistic training. Speech samples were recorded from 18 international students from Hispanic, Asian, and Middle-eastern backgrounds and across all proficiency levels as designated by their academic English program. Six native English speakers were also recorded to serve as a basis for comparison. Listeners were drawn from two pools: people with ESL and/or linguistic training (n=42) and laypersons with no such specialist training (n=36). After completing a background questionnaire to assess familiarity with foreign accented speech, each listener rated all 24 speech samples on the dimensions of comprehensibility, degree of accent, and communicative ability. Results indicate that participants with ESL/linguistic training rate foreign accented speech more positively on all three dimensions than laypersons with no such training. Additionally, degree of familiarity with foreign accented speech is positively correlated with how participants rated the accented speech samples. a number of highly significant interactions between these and other factors including sex of the speaker, proficiency level of the speaker, and L1 family of the speaker were found as well
Materiais montessorianos para estudantes com paralisia cerebral no Ensino Fundamental
The present study aimed to investigate how the pedagogical materials developed by Maria Montessori can help in the development of children with cerebral palsy-CP in Elementary School. This research is qualitative, descriptive and explanatory, based on studies on cerebral palsy and Maria Montessori's scientific pedagogy. As a theoretical-methodological contribution, the writings of Sposito (2004), Duarte (2014) and Mantoan (2000) were sought. Based on the reference studied, the experience of building a Montessori pedagogical material was carried out and, then, it was inserted in the pedagogical activities of a student with cerebral palsy, who is attending the 4th year of the Initial Years in a Basic Education Unit of the municipal public school system in São LuÃs (MA). The importance and efficiency of such materials in the development and learning of students with cerebral palsy in regular education was confirmed, since they enabled the autonomy and sensorimotor development of this student.O presente estudo se propôs investigar como os materiais pedagógicos desenvolvidos por Maria Montessori podem auxiliar no desenvolvimento de crianças com paralisia cerebral-PC na etapa relativa ao Ensino Fundamental. Essa pesquisa é de natureza qualitativa do tipo descritiva e explicativa, fundamentada em estudos sobre a paralisia cerebral e a pedagogia cientÃfica de Maria Montessori. Como aporte teórico-metodológico, buscou-se os escritos de Mantoan (2000), Sposito (2004) e Duarte (2014). Com base no referencial estudado, realizou-se a experiência de construção de um material pedagógico montessoriano para que, posteriormente, fosse inserido nas atividades pedagógicas de uma estudante com paralisia cerebral que cursa o 4º ano dos Anos Iniciais em uma Unidade de Educação Básica da rede pública municipal de ensino de São LuÃs (MA). Ratificou-se a importância e eficiência de tais materiais no desenvolvimento e aprendizagem de estudantes com paralisia cerebral no ensino regular, uma vez que possibilitaram a autonomia e desenvolvimento sensório-motor desta aluna
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