56 research outputs found

    HOW COLLABORATIVE LEARNING AFFECTS STUDENT PERCEPTION AND COMPREHENSION OF ELECTROMAGNETIC RADIATION IN AN INTRODUCTORY ASTRONOMY CLASS

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    This research explores student perception of collaborative learning and comprehension of electromagnetic radiation in a university level introductory astronomy class. Collaborative learning is an instructional strategy in which small groups of students complete a common task such as answering a question, discussing a concept, creating a presentation, or conducting an experiment. Collaborative learning changes students\u27 and teachers\u27 roles in classrooms by shifting the focus from the teacher to the student-centered collaborative group. Collaborative learning may support students’ comprehension of the course material through peer discussion and input, in order to construct knowledge with the help of their peers. This research seeks to explore student perception of collaborative learning in an introductory astronomy class through case study. Also, student comprehension of electromagnetic radiation is assessed by pretest and posttest. A review of the literature shows that while there have been extensive studies on collaborative learning, the effects of collaborative learning in the discipline of astronomy at the university level have not been widely researched. The analysis of the quantitative data supports collaborative learning as a means of improving student comprehension. Observation of student engagement in collaborative learning as well as participant interviews indicate that students generally hold a positive perception of working in a small collaborative group environment, but they found collaborative interaction in a large expert group to be problematic, stressful, and detrimental to the collaborative learning process

    Doing the Right Thing : A Study of Cross-Generational Eldercare Decision-making in Community and Disease Context

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    Utilizing the sociology of knowledge perspective, as well as elements of structural-functional theory this study examined the decision-making process as it relates to eldercare. Specifically, how does the knowledge of available resources, community context, and caregiving beliefs affect the caregiving alternative one chooses? Furthermore, what role does family social milieus play in the decision-making process? This research used a 20-item interview schedule developed specifically for this study; and the unit of analysis was the individual responsible for making decisions about the care received by an elder. The survey used both closed and open-ended questions, designed to capture data related to the cultural, socio-demographic, and social structural level of each respondent. Thirty-three (33) individuals responsible for eldercare decision-making completed an interview, which took anywhere from 45 minutes to 2 hours to complete. Data from closed ended questions were coded and entered into an SPSS file. The data from open-ended questions were summarized on a case-by-case basis and the content analyzed for particular themes or patterns that could be measured. Finding from this study, as well as policy recommendations are discussed, concentrating on social service agencies, medical organizational resources, public education as it relates to social and medical agencies, and economic and medical dilemmas effecting decision-makers

    Doing the Right Thing : A Study of Cross-Generational Eldercare Decision-making in Community and Disease Context

    Get PDF
    Utilizing the sociology of knowledge perspective, as well as elements of structural-functional theory this study examined the decision-making process as it relates to eldercare. Specifically, how does the knowledge of available resources, community context, and caregiving beliefs affect the caregiving alternative one chooses? Furthermore, what role does family social milieus play in the decision-making process? This research used a 20-item interview schedule developed specifically for this study; and the unit of analysis was the individual responsible for making decisions about the care received by an elder. The survey used both closed and open-ended questions, designed to capture data related to the cultural, socio-demographic, and social structural level of each respondent. Thirty-three (33) individuals responsible for eldercare decision-making completed an interview, which took anywhere from 45 minutes to 2 hours to complete. Data from closed ended questions were coded and entered into an SPSS file. The data from open-ended questions were summarized on a case-by-case basis and the content analyzed for particular themes or patterns that could be measured. Finding from this study, as well as policy recommendations are discussed, concentrating on social service agencies, medical organizational resources, public education as it relates to social and medical agencies, and economic and medical dilemmas effecting decision-makers

    Mechanisms of intron gain and loss in Drosophila

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    <p>Abstract</p> <p>Background</p> <p>It is widely accepted that orthologous genes have lost or gained introns throughout evolution. However, the specific mechanisms that generate these changes have proved elusive. Introns are known to affect nearly every level of gene expression. Therefore, understanding their mechanism of evolution after their initial fixation in eukaryotes is pertinent to understanding the means by which organisms develop greater regulation and complexity.</p> <p>Results</p> <p>To investigate possible mechanisms of intron gain and loss, we identified 189 intron gain and 297 intron loss events among 11 Drosophila species. We then investigated these events for signatures of previously proposed mechanisms of intron gain and loss. This work constitutes the first comprehensive study into the specific mechanisms that may generate intron gains and losses in Drosophila. We report evidence of intron gain via transposon insertion; the first intron loss that may have occurred via non-homologous end joining; intron gains via the repair of a double strand break; evidence of intron sliding; and evidence that internal or 5' introns may not frequently be deleted via the self-priming of reverse transcription during mRNA-mediated intron loss. Our data also suggest that the transcription process may promote or result in intron gain.</p> <p>Conclusion</p> <p>Our findings support the occurrence of intron gain via transposon insertion, repair of double strand breaks, as well as intron loss via non-homologous end joining. Furthermore, our data suggest that intron gain may be enabled by or due to transcription, and we shed further light on the exact mechanism of mRNA-mediated intron loss.</p

    Identifying the mechanisms of intron gain: progress and trends

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    Continued improvements in Next-Generation DNA/RNA sequencing coupled with advances in gene annotation have provided researchers access to a plethora of annotated genomes. Subsequent analyses of orthologous gene structures have identified numerous intron gain and loss events that have occurred both recently and in the very distant past. This research has afforded exceptional insight into the temporal and lineage-specific rates of intron gain and loss among various species throughout evolution. Numerous studies have also attempted to identify the molecular mechanisms of intron gain and loss. However, even after considerable effort, very little is known about these processes. In particular, the mechanism(s) of intron gain have proven exceptionally enigmatic and remain topics of considerable debate. Currently, there exists no definitive consensus as to what mechanism(s) may generate introns. Because many introns are known to affect gene expression, it is necessary to understand the molecular process(es) by which introns may be gained. Here we review the seven most commonly purported mechanisms of intron gain and, when possible, summarize molecular evidence for or against the occurrence of each of these mechanisms. Furthermore, we catalogue indirect evidence that supports the occurrence of each mechanism. Finally, because these proposed mechanisms fail to explain the mechanistic origin of many recently gained introns, we also look at trends that may aid researchers in identifying other potential mechanism(s) of intron gain.This article was reviewed by Eugene Koonin, Scott Roy (nominated by W. Ford Doolittle), and John Logsdon. © 2012 Yenerall and Zhou; licensee BioMed Central Ltd

    Determining the Locations of Dust Sources in FeLoBAL Quasars

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    We conduct a spectroscopic search of quasars observed by the Sloan Digital Sky Survey (SDSS) with broad absorption line (BAL) troughs due to Mg II and troughs due to Fe II that simultaneously exhibit strong Balmer narrow emission lines (NELs). We find that in a redshift range of 0.4 less than or equal to z less than or equal to 0.9 approximately 23 of the 70 Mg II BALs and 4 of a subset of 15 Fe II BALs exhibit strong Balmer emission. We also find significant fractions of Mg II BALs (approximately 23%) and those Mg II BALs with Fe II troughs (approximately 27%) have strong continuum reddening, E(B - V) greater than or equal to 0.1. From measurements of the Balmer decrement in three objects, we find similarly significant reddening of the NEL region in three of the four objects; the NELs in the fourth object are not measurable. We also include one object in this study not taken from the SDSS sample that shows Fe II absorption and strong narrow emission, but due to measurement uncertainty and low continuum reddening the comparison is consistent but inconclusive. We find a trend in both the Mg II and Fe II BAL samples between the NEL reddening and continuum reddening. Because the narrow line reddening is consistent with the continuum reddening in every object in the two SDSS samples, it suggests that the reddening sources in these objects likely exist at larger radial distances than the narrow line regions from the central nucleus.Comment: 40 manuscript pages, accepted in ApJ (July

    The complex intron landscape and massive intron invasion in a picoeukaryote provides insights into intron evolution

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    Genes in pieces and spliceosomal introns are a landmark of eukaryotes, with intron invasion usually assumed to have happened early on in evolution. Here, we analyse the intron landscape of Micromonas, a unicellular green alga in the Mamiellophyceae lineage, demonstrating the co-existence of several classes of introns and the occurrence of recent massive intron invasion. This study focuses on two strains, CCMP1545 and RCC299, and their related individuals from ocean samplings, showing that they not only harbour different classes of introns depending on their location in the genome, as for other Mamiellophyceae, but uniquely carry several classes of repeat introns. These introns, dubbed introner elements (IEs), are found at novel positions in genes and have conserved sequences, contrary to canonical introns. This IE invasion has a huge impact on the genome, doubling the number of introns in the CCMP1545 strain. We hypothesize that each IE class originated from a single ancestral IE that has been colonizing the genome after strain divergence by inserting copies of itself into genes by intron transposition, likely involving reverse splicing. Along with similar cases recently observed in other organisms, our observations in Micromonas strains shed a new light on the evolution of introns, suggesting that intron gain is more widespread than previously thought

    Taxane-Platin-Resistant Lung Cancers Co-develop Hypersensitivity to JumonjiC Demethylase Inhibitors

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    Although non-small cell lung cancer (NSCLC) patients benefit from standard taxane-platin chemotherapy, many relapse, developing drug resistance. We established preclinical taxane-platin-chemoresistance models and identified a 35-gene resistance signature, which was associated with poor recurrence-free survival in neoadjuvant-treated NSCLC patients and included upregulation of the JumonjiC lysine demethylase KDM3B. In fact, multi-drug-resistant cells progressively increased the expression of many JumonjiC demethylases, had altered histone methylation, and, importantly, showed hypersensitivity to JumonjiC inhibitors in vitro and in vivo. Increasing taxane-platin resistance in progressive cell line series was accompanied by progressive sensitization to JIB-04 and GSK-J4. These JumonjiC inhibitors partly reversed deregulated transcriptional programs, prevented the emergence of drug-tolerant colonies from chemo-naive cells, and synergized with standard chemotherapy in vitro and in vivo. Our findings reveal JumonjiC inhibitors as promising therapies for targeting taxane-platin-chemoresistant NSCLCs.Fil: Dalvi, Maithili P.. University of Texas. Southwestern Medical Center; Estados UnidosFil: Wang, Lei. University of Texas. Southwestern Medical Center; Estados UnidosFil: Zhong, Rui. University of Texas. Southwestern Medical Center; Estados UnidosFil: Kollipara, Rahul K.. University of Texas. Southwestern Medical Center; Estados UnidosFil: Park, Hyunsil. University of Texas. Southwestern Medical Center; Estados UnidosFil: Bayo Fina, Juan Miguel. University of Texas. Southwestern Medical Center; Estados Unidos. Universidad Austral. Facultad de Ciencias Biomédicas. Instituto de Investigaciones en Medicina Traslacional. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Medicina Traslacional; ArgentinaFil: Yenerall, Paul. University of Texas. Southwestern Medical Center; Estados UnidosFil: Zhou, Yunyun. University of Texas. Southwestern Medical Center; Estados UnidosFil: Timmons, Brenda C.. University of Texas. Southwestern Medical Center; Estados UnidosFil: Rodriguez Canales, Jaime. University of Texas; Estados UnidosFil: Behrens, Carmen. Md Anderson Cancer Center; Estados UnidosFil: Mino, Barbara. University of Texas; Estados UnidosFil: Villalobos, Pamela. University of Texas; Estados UnidosFil: Parra, Edwin R.. University of Texas; Estados UnidosFil: Suraokar, Milind. University of Texas; Estados UnidosFil: Pataer, Apar. University of Texas; Estados UnidosFil: Swisher, Stephen G.. University of Texas; Estados UnidosFil: Kalhor, Neda. University of Texas; Estados UnidosFil: Bhanu, Natarajan V.. University of Pennsylvania; Estados UnidosFil: Garcia, Benjamin A.. University of Pennsylvania; Estados UnidosFil: Heymach, John V.. University of Texas; Estados UnidosFil: Coombes, Kevin. University of Texas; Estados UnidosFil: Xie, Yang. University of Texas. Southwestern Medical Center; Estados UnidosFil: Girard, Luc. University of Texas. Southwestern Medical Center; Estados UnidosFil: Gazdar, Adi F.. University of Texas. Southwestern Medical Center; Estados UnidosFil: Kittler, Ralf. University of Texas. Southwestern Medical Center; Estados UnidosFil: Wistuba, Ignacio I.. University of Texas; Estados UnidosFil: Minna, John D.. University of Texas. Southwestern Medical Center; Estados UnidosFil: Martinez, Elisabeth D.. University of Texas. Southwestern Medical Center; Estados Unido
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