35 research outputs found
Presence of microplastics in tilapia (Oreochromis niloticus) along the Iloilo River
No full textAbstract onlyMicroplastic pollution poses a significant threat to aquatic ecosystems, with potential consequences for biodiversity and human health. This study investigates the presence and characteristics of microplastics in tilapia (Oreochromis niloticus) inhabiting the Iloilo River, a vital watercourse in the Philippines. Samples were collected from three distinct sites along the river: Barangay Tap-oc, Barangay San Rafael, and Barangay Progreso. A total of 45 tilapia specimens were examined, and microplastics were isolated from the gill and gut tissues using chemical digestion and filtration techniques. The results revealed a high detection rate of microplastics, with 95.6% of the fish specimens containing these contaminants. A total of 132 microplastic particles were identified, with fibrous morphologies being the most prevalent (70.5%), followed by particles (22.7%) and pellets (6.8%). Blue microplastics constituted the dominant color (50.0%), succeeded by red (21.2%) and black (15.9%). Statistical analysis demonstrated significant variations in microplastic abundance across sampling locations, with Barangay Tap-oc exhibiting the highest contamination levels. These findings underscore the pervasive nature of microplastic pollution in the Iloilo River ecosystem and the potential risks it poses to aquatic life and human health.Includes bibliographical referencesBachelor of Science in Environmental Managemen
Learning-Derived Cost Evolution in Materials Selection
No full textThesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2010.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from student submitted PDF version of thesis.Includes bibliographical references (p. 163-168).Materials selection is a complex, but important, problem for manufacturing firms. Poor material choices can negatively affect the firm's market share or profits. In the face of this complexity, most selection methods make a number of simplifications, including limiting problem scope to selection for a single product or application, and assuming material properties and design criteria are constant over the problem's time horizon. Such assumptions, however, do not always apply, especially when material preference is based on the materials' "emergent properties," the values of which are context-dependent. Consequently, these properties can evolve with changes in context and potentially alter the preferred material identified by the selection method. This thesis investigates the impact of considering cost evolution on a firm's materials selection decision, and seeks to identify strategies the firm can adopt when introducing new materials to its products. To that end, a framework for incorporating cost evolution, specifically from learning, into the materials selection process is proposed and demonstrated using single-product and multi-product automotive case studies. In the single-product method, material options are ranked by their respective manufacturing costs. The multi-product problem is more complex and requires an analytical framework that combines an integer linear program and a genetic algorithm to select materials for any number of products over a specified time horizon. Case study results indicate that when selection problem scope is limited to a single product, accounting for learning in the decision process has minimal impact on the preferred material. When several products are included in the problem scope, however, the firm is able to leverage "shared learning" so that experience gained from manufacturing one product can be applied to lower the costs of other products that share a common resource, such as a manufacturing process line, with the initial product. Not only does the consideration of shared learning impact the preferred materials that are suggested by the selection framework, it also helps to better characterize the circumstances under which the firm should introduce a new material on a test bed. Additionally, the case study results emphasize the use of one material across multiple applications and indicate that this approach helps the firm cope with uncertainty in selection criteria.by Trisha M. Montalbo.Sc.D
Enhancing learning and memory in the aged: Interactions between dietary supplementation and exercise
No full textItem marked as restricted to the 'Administrator' Group (id=1) by Seth Robbins ([email protected]) on 2014-05-30T17:21:44Z
Item is restricted until 2016-05-30T17:21:23ZRestriction data tranferred 2014-07-01T11:39:49-05:00
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Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemLimited Restriction Lifted for Item 49893 on 2016-09-22T20:59:18Z.Age associated cognitive decline in human and rodents has been linked with decreases in hippocampal neurogenesis and a chronic low grade inflammation in the central nervous system. Physical exercise increases neurogenesis and reverses some cognitive deficits observed in the elderly, but the extent to which dietary supplementation may interact with exercise is unknown. Epigallocatechin gallate (EGCG, a catechin high in green tea) can ameliorate age-related cognitive decline. In addition, β-alanine (β-Ala, a naturally occurring amino acid) may be beneficial against cognitive aging. We hypothesized that exercise (voluntary wheel running, VWR) and dietary supplementation with EGCG (182 mg/kg/d) and β-Ala (417 mg/kg/d) would interact to improve cognition of aged mice. Balb/c mice aged (19 mo) served as sedentary controls or were provided access to running with or without EGCG + β-Ala for 4 weeks. The Morris water maze (MWM) and contextual fear conditioning (CFC) were used to assess learning and memory while BrdU labeling was used to measure new cell proliferation in the dentate gyrus (DG). VWR improved cognition during probe trials in the MWM, increased time spent frozen during both context and auditory cue testing in CFC, and increased BDNF mRNA expression within hippocampus. Dietary supplementation did not affect any of these measurements. Collectively, these data verify that exercise has positive effects on cognition of aged mice by enhancing newborn cells in the DG and increasing neurotrophin expression.Item withdrawn by Laura Spradlin ([email protected]) on 2014-05-01T21:41:04Z
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University of Illinois Theses & Dissertations (ID: 1)
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COLLABORATIVELY - LED LIVING LEARNING PROGRAMS: AN EXPLORATION FOR HOW COLLABORATION IS FACILITATED BETWEEN STUDENT AFFAIRS UNITS AND ACADEMIC AFFAIRS IN LLPS
No full textAccording to Inkelas et al. (2008), Living Learning Programs (LLPs) that are collaboratively led by academic affairs and student affairs units tend to have a significant impact on student learning, when compared to students who participate in LLPs that are operated by one unit (Inkelas et al., 2008). Despite evidence that co-authored LLPs are beneficial to enhancing the LLP student experience, there is little to no research that explores how administrators facilitate collaboration between the units used to co-author the LLP student experience. For this reason, the focus of this study was to explore how administrators facilitate collaboration between academic affairs and students affairs units in the context of LLPs. A sequential explanatory mixed methods approach revealed that collaboration between both units is facilitated through a series of four factors; (a) Mutually supportive relationships, (b) LLP coordinators, (c) collaborative networks and (d) mechanisms for collaboration. In addition, LLP administrators throughout the study demonstrated a high effort of collaboration on co-curricular programming and slightly less of an effort to collaborate on items related to curricular or judicial engagement of LLP students
Thesis Launch: Helping Students Begin the Undergraduate Honors Thesis Process
No full textabstract: Honors colleges have offered an academically rigorous option for growing numbers of diverse students. This study took place at a large, public university that required undergraduate students to complete a thesis to graduate from the honors college. In 2017, 97% of students who began the honors thesis prior to senior year completed it. Thus, the aim of this study was to help more students begin the honors thesis process early.
Thesis Launch was a six-week intervention that was designed to provide support for students in the critical early steps of thesis work such as brainstorming topics, examining professors’ research interests, reaching out to professors, preparing for meetings with potential thesis committee members, and writing a thesis prospectus. Thesis Launch offered web-based resources, weekly emails and text message reminders, and was supplemented by in-person advising options.
A mixed methods action research study was conducted to examine: (a) students’ perceptions of barriers that prevented beginning thesis work; (b) self-efficacy towards thesis work; (c) how to scale the intervention using technology; and (d) whether participants began the thesis early. Quantitative data was collected via pre- and post-intervention surveys, journals, and prospectus submissions. Qualitative data came from student interviews, journals, and open-ended questions on the surveys.
Quantitative data showed that after students participated in Thesis Launch, they had higher self-efficacy to work with professors, perceived fewer barriers to thesis work, and greater proportions of students began thesis work early. The qualitative data were complementary and showed that participants overcame barriers to thesis initiation, built self-efficacy, preferred an online intervention, and began thesis work early. Findings also showed that a primarily technology-based intervention was preferred by students and showed promise for scaling to a larger audience.
Thesis Launch provided a framework for students to begin work on the honors thesis and have mastery experiences to build self-efficacy. Strategies that fostered “small wins” and reflective efforts also assisted in this aim. Participants accomplished tasks tied to thesis work and customized their personal thesis timelines based on work begun during Thesis Launch. Finally, a discussion of limitations, implications for practice and research, and personal reflection was included.Dissertation/ThesisDoctoral Dissertation Educational Leadership and Policy Studies 201
Patterns of analytical thinking and knowledge use in students' early understanding of the limit concept.
No full textThis study explored first-semester calculus students' early understanding of limits, relative to their function knowledge and graphing calculator use. The purpose was to identify and describe students' patterns of analytical thinking and knowledge use in determining limit situations, as a first step in developing a grounded theory of early development of intuitive limit concepts.Students in this study had difficulty determining local function behavior, and did not always connect this to determining limit situations. They could read graphs and tables to conjecture limits, but often based such conjectures on poor tables or graphs. They learned that tables and graphs might mislead them, but rarely analyzed this, either assuming representativeness or assuming they were being misled. These students relied on formula-based expectations, graphs, or a few function values in determining limit situations. They did not know how to move from "almost certain" to certain in determining a limit situation.Over four task-based interviews, ten students progressed from examining local function behavior to analyzing increasingly difficult limit situations. Written and oral responses were analyzed relative to a four-element framework developed by the author: (a) analyzing functions locally in graphical and numerical settings; (b) conjecturing limits from representative graphs and tables; (c) understanding advantages and limitations of tables and graphs to conjecturing limits, particularly when using graphing calculators; and (d) producing multiple sources of evidence to justify a limit conjecture, and knowing whether this evidence is sufficient. Students demonstrating these four elements were deemed to have an intuitive-analytic understanding of the limit concept.The graphing calculator played a significant role. Graphs and tables on the calculator were often taken as the "standard" of comparison, without analysis. Awareness of calculator limitations did not necessarily imply correct limit conjectures, due to ignoring the limitations, or erroneously assuming the effects of those limitations.These students' function knowledge and methods of analyzing local function behavior both did and did not influence their determination of limit situations. Partial analyses led them to accept non-representative behavior, which led to erroneous limit conjectures. On the other hand, even full and complete analyses did not always result in correct limit conjectures
Author Correction: The future of Blue Carbon science
No full textAuthor Correction: The future of Blue Carbon scienc
ASCL1 and NEUROD1 Reveal Heterogeneity in Pulmonary Neuroendocrine Tumors and Regulate Distinct Genetic Programs
No full textSummarySmall cell lung carcinoma (SCLC) is a high-grade pulmonary neuroendocrine tumor. The transcription factors ASCL1 and NEUROD1 play crucial roles in promoting malignant behavior and survival of human SCLC cell lines. Here, we find that ASCL1 and NEUROD1 identify heterogeneity in SCLC, bind distinct genomic loci, and regulate mostly distinct genes. ASCL1, but not NEUROD1, is present in mouse pulmonary neuroendocrine cells, and only ASCL1 is required in vivo for tumor formation in mouse models of SCLC. ASCL1 targets oncogenic genes including MYCL1, RET, SOX2, and NFIB while NEUROD1 targets MYC. ASCL1 and NEUROD1 regulate different genes that commonly contribute to neuronal function. ASCL1 also regulates multiple genes in the NOTCH pathway including DLL3. Together, ASCL1 and NEUROD1 distinguish heterogeneity in SCLC with distinct genomic landscapes and distinct gene expression programs
Isotonic Resistance Exercise Outperforms Eccentric Quasi-Isometric Resistance Exercise for Increasing Elbow Flexor Muscle Thickness and Estimated One-Repetition Maximum in Untrained Individuals: Exploring the Influence of Sex and Volume
No full textAs a novel, low-velocity resistance exercise method, eccentric quasi-isometric resistance exercise (EQI-RE) results in greater time under tension than traditional isotonic resistance exercise (TRD-RE) and is surmised to increase muscle mass and strength. However, females may be more fatigue resistant than males when performing acute EQI-RE, which could lead to long-term differences in time under tension and resistance exercise volume. At present, studies have yet to compare muscle hypertrophy or strength improvements following TRD-RE and EQI-RE training, and whether sex-differences exist in these outcomes. Twenty-two (n = 13 females) untrained individuals completed ~8-weeks of effort matched unilateral TRD-RE and EQI-RE of the elbow flexors. Muscle thickness and estimated one-repetition maximum (E-1RM) were evaluated before and after training. TRD-RE produced significantly larger relative increases in muscle thickness (6.7% ± 3.9% vs. 4.0 ± 3.3%, p =.004) and E-1RM (19.6 ± 8.5% vs. 12.8 ± 6.2%, p = .001) than EQI-RE. Although females accrued greater resistance exercise volume than males across the TRD-RE and EQI-RE training, there were no relative sex-differences in muscle thickness or E-1RM improvements (p > .25). Sex-differences in fatiguability may therefore manifest in differences in resistance exercise volume between males and females after 8-weeks of TRD-RE and EQI-RE of the elbow flexors, but this does not lead to relative differences in muscle thickness or E-1RM improvements. Although EQI-RE did produce significant increases, TRD-RE of the elbow flexors appears more effective at increasing muscle thickness and E-1RM.The presentation of the authors' names and (or) special characters in the title of the pdf file of the accepted manuscript may differ slightly from what is displayed on the item page. The information in the pdf file of the accepted manuscript reflects the original submission by the author
