Exploring Cultural Competence amongst OT Students

Directory of Open Access Journals (Sweden)

Pragashnie Govender

2017-01-01

Full Text Available Occupational therapy relies primarily on communication between the therapist and client for effective intervention. Adequate communication may be influenced by language and cultural differences between the therapist and client. Cultural competence in relation to language and culture is thus a vital part in practice. Limited research exists on cultural competence in occupational therapy students. This study thus aimed to explore the cultural competence of final year students and their perceptions of their own cultural competence, with respect to language and culture in their practice as students. An explorative qualitative study design was utilised with a nonprobability purposeful sample of 21 final year undergraduate students at a tertiary institute in South Africa. Three focus groups were conducted, comprising between 6 and 8 students in each group. Thematic analysis using inductive reasoning was undertaken in order to analyse the students’ experiences and understanding of cultural competence. Findings of the study suggest that cultural competence, in relation to language and culture, influences the occupational therapy intervention process. It was shown to both positively and negatively influence intervention through supporting or hindering rapport building, client centeredness, and effective intervention.

High-LET particle exposure of Skylab astronauts

International Nuclear Information System (INIS)

Benton, E.V.; Peterson, D.D.; Bailey, J.V.; Parnell, T.

1977-01-01

High-LET particle radiation was registered in nuclear track recording plastic dosimeters worn on the wrists of Skylab astronauts and located in a heavily shielded film vault. The mission-average planar flux of high-LET particles with LET >= 100 keV/micron . tissue has been determined to be 2.7 +- 0.6 particles/cm 2 . day . 2π sr and 0.34 +- 0.4 particles/cm 2 . day . 2π sr, respectively, for the nine astronauts and for the film vault. Comparison of results representative of a wide range of shielding depths reveals that the magnitude and slope of the integral LET spectrum of high-LET particles inside spacecraft are proportional to the amount of shielding. (author)

Ataxia telangiectasia: LET dependence of cellular inactivation

International Nuclear Information System (INIS)

Blakely, E.A.; Tobias, C.A.

1984-01-01

Human Ataxia telangiectasia cells (AT 2SF line) have been irradiated in vitro under aerobic and hypoxic conditions with heavy-ion beams accelerated at the Berkeley Bevalac as a part of a study to characterize the radiation responses of genetically sensitive and resistant cell lines to high LET radiations. Results from track-segment exposures to neon, silicon, argon and iron ion beams accelerated to initial energies of from 225 to 670 MeV/amu provided an LET range between 30 to 1,000 KeV/μm. The data indicate: (1) The sensitivity of AT cells increases with increasing LET, similar to resistant human lines (e.g., T-1 cells). However, due to efficient repair, T-1 cells are more resistant than AT cells at LET values below 200 keV/μm; (2) Maximum cell kill occurs for both lines at 100-200 keV/μm; at higher LET the sensitivity of the two lines approach each other; (3) There is only small variation in the sensitivity of AT cells to particles of various atomic numbers at the same LET; differences are more pronounced in the LET domain between 50 and 200 keV/μm; and (4) AT cells have slightly lower OER values than T-1 cells in the range of LET studied below 200 keV/μm

Calculated LET-Spectrum of Antiprotons

DEFF Research Database (Denmark)

Bassler, Niels

-LET components resulting from the annihilation. Though, the calculations of dose-averaged LET in the entry region may suggest that the RBE of antiprotons in the plateau region could significantly differ from unity. Materials and Methods Monte Carlo simulations using FLUKA were performed for calculating...

The concept of average LET values determination

International Nuclear Information System (INIS)

Makarewicz, M.

1981-01-01

The concept of average LET (linear energy transfer) values determination, i.e. ordinary moments of LET in absorbed dose distribution vs. LET of ionizing radiation of any kind and any spectrum (even the unknown ones) has been presented. The method is based on measurement of ionization current with several values of voltage supplying an ionization chamber operating in conditions of columnar recombination of ions or ion recombination in clusters while the chamber is placed in the radiation field at the point of interest. By fitting a suitable algebraic expression to the measured current values one can obtain coefficients of the expression which can be interpreted as values of LET moments. One of the advantages of the method is its experimental and computational simplicity. It has been shown that for numerical estimation of certain effects dependent on LET of radiation it is not necessary to know the dose distribution but only a number of parameters of the distribution, i.e. the LET moments. (author)

Career exploration behavior of Korean medical students.

Science.gov (United States)

An, Hyejin; Lee, Seung-Hee

2017-09-01

This study is to analyze the effects of medical students' social support and career barriers on career exploration behavior mediated by career decision-making self-efficacy. We applied the t-test to investigate the difference among the variables based on gender and admission types. Also, we performed path analysis to verify the effect of perceived career barriers and social support on career exploration behavior with career decision efficacy as a mediator. First, we noted statistically significant gender and admission type difference in social support, career barriers and career exploration behaviors. Second, social support and career barriers were found to influence career exploration behavior as a mediating variable for career decision-making self-efficacy. Social support and career barriers as perceived by medical students influenced their career exploration behavior, with their decision-making self-efficacy serving as a full mediator. Therefore, this study has educational implications for career program development and educational training for career decision-making self-efficacy.

Inactive and mutagenic effects induced by carbon beams of different LET values in a red yeast strain

International Nuclear Information System (INIS)

Wang Jufang; Lu Dong; Wu Xin; Sun Haining; Ma Shuang; Li Renmin; Li Wenjian

2010-01-01

To evaluate biological action of microorganism exposed to charged particles during the long distance space exploration, induction of inactivation and mutation in a red yeast strain Rhodotorula glutinis AY 91015 by carbon beams of different LET values (14.9-120.0 keV μm -1 ) was investigated. It was found that survival curves were exponential, and mutation curves were linear for all LET values. The dependence of inactivation cross section on LET approached saturation near 120.0 keV μm -1 . The mutation cross section saturated when LET was higher than 58.2 keV μm -1 . Meanwhile, the highest RBE i for inactivation located at 120.0 keV μm -1 and the highest RBE m for mutation was at 58.2 keV μm -1 . The experiments imply that the most efficient mutagenic part of the depth dose profile of carbon ion is at the plateau region with intermediate LET value in which energy deposited is high enough to induce mutagenic lesions but too low to induce over kill effect in the yeast cells.

Inactive and mutagenic effects induced by carbon beams of different LET values in a red yeast strain

Science.gov (United States)

Wang, Jufang; Lu, Dong; Wu, Xin; Sun, Haining; Ma, Shuang; Li, Renmin; Li, Wenjian

2010-09-01

To evaluate biological action of microorganism exposed to charged particles during the long distance space exploration, induction of inactivation and mutation in a red yeast strain Rhodotorula glutinis AY 91015 by carbon beams of different LET values (14.9-120.0 keV μm -1) was investigated. It was found that survival curves were exponential, and mutation curves were linear for all LET values. The dependence of inactivation cross section on LET approached saturation near 120.0 keV μm -1. The mutation cross section saturated when LET was higher than 58.2 keV μm -1. Meanwhile, the highest RBE i for inactivation located at 120.0 keV μm -1 and the highest RBE m for mutation was at 58.2 keV μm -1. The experiments imply that the most efficient mutagenic part of the depth dose profile of carbon ion is at the plateau region with intermediate LET value in which energy deposited is high enough to induce mutagenic lesions but too low to induce over kill effect in the yeast cells.

Let them eat cake!

OpenAIRE

Samson, Audrey; Gallardo, Francisco; FRAUD, -

2017-01-01

Let them eat cake!' is a food-led event serving an edible imaginary of a Facebook profile. In early 2012, Facebook conducted massive scale emotional contagion by manipulating the emotional expressions in the News Feeds of 689,003 users. This exemplifies how the governability and the biopolitics of everyday life flow through the many layers of shared images, liked videos, protocols, and hyperlinks, all orchestrated by the Facebook News Feed algorithm. 'Let them eat cake!' proposes a gustatory ...

77 FR 16566 - Submission for OMB Review, Comment Request, Proposed Collection: Let's Move Museums, Let's Move...

Science.gov (United States)

2012-03-21

..., Proposed Collection: Let's Move Museums, Let's Move Gardens AGENCY: Institute of Museum and Library..., comment request. SUMMARY: The Institute of Museum and Library Services announces that the following... functions of the agency, including whether the information will have practical utility; Evaluate the...

'The Gentle Art of Letting the Other Fellow Have Your Own Way ...

African Journals Online (AJOL)

'The Gentle Art of Letting the Other Fellow Have Your Own Way': Viewpoints on a Media Narrative used to Promote the Proposed N2 Toll Road. ... We highlight the importance of developing 'media literacy' – reading skills which enable the critical deconstruction of media texts. We explore, more specifically, the public ...

Exploring classical Greek construction problems with interactive geometry software

CERN Document Server

Meskens, Ad

2017-01-01

In this book the classical Greek construction problems are explored in a didactical, enquiry based fashion using Interactive Geometry Software. The book traces the history of these problems, stating them in modern terminology. By focusing on constructions and the use of GeoGebra the reader is confronted with the same problems that ancient mathematicians once faced. The reader can step into the footsteps of Euclid, Viète and Cusanus amongst others and then by experimenting and discovering geometric relationships far exceed their accomplishments. Exploring these problems with the neusis-method lets him discover a class of interesting curves. By experimenting he will gain a deeper understanding of how mathematics is created. More than 100 exercises guide him through methods which were developed to try and solve the problems. The exercises are at the level of undergraduate students and only require knowledge of elementary Euclidean geometry and pre-calculus algebra. It is especially well-suited for those student...

Exploring Non-Instructional Factors in Student Evaluations

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Ali, Holi Ibrahim Holi; Al Ajmi, Ahmed Ali Saleh

2013-01-01

The use of student ratings to measure instructors' teaching performance and effectiveness in tertiary education has been an important but controversial tool in the improvement of teaching quality during the past few decades. This is an attempt to explore non-instructional factors of student evaluations by discussing and reviewing relevant…

Exploring Elementary Student Perceptions of Writing Feedback

Science.gov (United States)

Marrs, Sarah; Zumbrunn, Sharon; McBride, Caitlin; Stringer, J. K.

2016-01-01

The purpose of this descriptive qualitative investigation was to explore elementary students' (N = 867) perceptions of the feedback they receive on their writing. After responding to the closed-ended question, "Do you like to receive feedback about your writing?" students were branched to the appropriate follow-up open-ended question,…

"Let Your Data Tell a Story:" Climate Change Experts and Students Navigating Disciplinary Argumentation in the Classroom

Science.gov (United States)

Walsh, Elizabeth Mary; McGowan, Veronica Cassone

2017-01-01

Science education trends promote student engagement in authentic knowledge in practice to tackle personally consequential problems. This study explored how partnering scientists and students on a social media platform supported students' development of disciplinary practice knowledge through practice-based learning with experts during two pilot…

LETs and NETs: Exploring How Teachers from Diverse Cultural Backgrounds Impact Student Motivation and Preferences

Science.gov (United States)

Wong, Ruth

2014-01-01

This paper, an exploratory case study, examines how students' preferences and motivation to learn English are influenced by their perceptions of teaching practices--both of native English teachers and local English teachers. To better understand the context of this research question, this study adopts a method of triangulation in collecting data:…

High School Student Opinion Polling on Career Exploration

Science.gov (United States)

Whitten, Leah Suzanne

2011-01-01

This study examines the use of student learning polls as indicators of student perceptions and influences on career exploration. No Child Left Behind requires schools that fail to make adequate yearly progress for two consecutive years to develop continuous improvement plans. The concept of career preparation for students is included in these…

Explor@ Advisory Agent: Tracing the Student's Trail.

Science.gov (United States)

Lundgren-Cayrol, Karin; Paquette, Gilbert; Miara, Alexis; Bergeron, Frederick; Rivard, Jacques; Rosca, Ioan

This paper presents research and development of an adaptive World Wide Web-based system called Explor@ Advisory Agent, capable of tailoring advice to the individual student's needs, actions, and reactions toward pedagogical events, as well as according to diagnosis of content acquisition. Explor@ Advisory Agent consists of two sub-systems, the…

LET effects on normal and radiosensitive cell lines

International Nuclear Information System (INIS)

Geard, C.R.; Travisano, M.

1986-01-01

Charged particles in the track segment mode were produced by the RARAF Van de Graaff accelerator and used to irradiate two CHO cell lines, a radiosensitive hypermutable line EM9 and its normal parent AA8. Asynchronous cells were irradiated attached to 6 micrometer thick Mylar with protons, deuterons and helium-3 particles at LETs ranging from 10 to 150 keV per micrometer. A 50 kVp x-ray tube integrated into the track segment facility provided a low LET comparison. Following irradiation cells were monitored for clonogenicity, and in a separate series of experiments frequencies of sister chromatid exchanges. Up to 9 experiments were carried out at each LET, with a total of 8 radiations of different LETs being compared. The optimally effective LET for cell survival was between 80 and 120 keV per micrometer, with the 150 keV per micrometer particles indicating energy wastage. The differential between the normal and radiosensitive cell lines was maintained at all LETs

Characterization and expression patterns of let-7 microRNA in the silkworm (Bombyx mori

Directory of Open Access Journals (Sweden)

Hong Kaili

2007-07-01

Full Text Available Abstract Background lin-4 and let-7, the two founding members of heterochronic microRNA genes, are firstly confirmed in Caenorhabditis elegans to control the proper timing of developmental programs in a heterochronic pathway. let-7 has been thought to trigger the onset of adulthood across animal phyla. Ecdysone and Broad-Complex are required for the temporal expression of let-7 in Drosophila melanogaster. For a better understanding of the conservation and functions of let-7, we seek to explore how it is expressed in the silkworm (Bombyx mori. Results One member of let-7 family has been identified in silkworm computationally and experimentally. All known members of this family share the same nucleotides at ten positions within the mature sequences. Sequence logo and phylogenetic tree show that they are not only conserved but diversify to some extent among some species. The bmo-let-7 was very lowly expressed in ova harvested from newborn unmated female adult and in individuals from the first molt to the early third instar, highly expressed after the third molt, and the most abundant expression was observed after mounting, particularly after pupation. The expression levels were higher at the end of each instar and at the beginning of each molt than at other periods, coinciding with the pulse of ecdysone and BR-C as a whole. Using cultured ovary cell line, BmN-SWU1, we examined the effect of altered ecdysone levels on bmo-let-7 expression. The expression was also detected in various tissues of day 3 of the fifth instar and of from day 7 of the fifth to pupa, suggesting a wide distributing pattern with various signal intensities. Conclusion bmo-let-7 is stage- and tissue-specifically expressed in the silkworm. Although no signals were detected during embryonic development and first larval instar stages, the expression of bmo-let-7 was observed from the first molt, suggesting that it might also function at early larval stage of the silkworm. The

Characterization and expression patterns of let-7 microRNA in the silkworm (Bombyx mori).

Science.gov (United States)

Liu, Shiping; Xia, Qingyou; Zhao, Ping; Cheng, Tingcai; Hong, Kaili; Xiang, Zhonghuai

2007-07-25

lin-4 and let-7, the two founding members of heterochronic microRNA genes, are firstly confirmed in Caenorhabditis elegans to control the proper timing of developmental programs in a heterochronic pathway. let-7 has been thought to trigger the onset of adulthood across animal phyla. Ecdysone and Broad-Complex are required for the temporal expression of let-7 in Drosophila melanogaster. For a better understanding of the conservation and functions of let-7, we seek to explore how it is expressed in the silkworm (Bombyx mori). One member of let-7 family has been identified in silkworm computationally and experimentally. All known members of this family share the same nucleotides at ten positions within the mature sequences. Sequence logo and phylogenetic tree show that they are not only conserved but diversify to some extent among some species. The bmo-let-7 was very lowly expressed in ova harvested from newborn unmated female adult and in individuals from the first molt to the early third instar, highly expressed after the third molt, and the most abundant expression was observed after mounting, particularly after pupation. The expression levels were higher at the end of each instar and at the beginning of each molt than at other periods, coinciding with the pulse of ecdysone and BR-C as a whole. Using cultured ovary cell line, BmN-SWU1, we examined the effect of altered ecdysone levels on bmo-let-7 expression. The expression was also detected in various tissues of day 3 of the fifth instar and of from day 7 of the fifth to pupa, suggesting a wide distributing pattern with various signal intensities. bmo-let-7 is stage- and tissue-specifically expressed in the silkworm. Although no signals were detected during embryonic development and first larval instar stages, the expression of bmo-let-7 was observed from the first molt, suggesting that it might also function at early larval stage of the silkworm. The detailed expression profiles in the whole life cycle and

Inactive and mutagenic effects induced by carbon beams of different LET values in a red yeast strain

Energy Technology Data Exchange (ETDEWEB)

Wang Jufang, E-mail: jufangwang@impcas.ac.c [Institute of Modern Physics, Chinese Academy of Sciences, Nanchang Road No. 509, Lanzhou 730000 (China); Lu Dong; Wu Xin; Sun Haining; Ma Shuang; Li Renmin; Li Wenjian [Institute of Modern Physics, Chinese Academy of Sciences, Nanchang Road No. 509, Lanzhou 730000 (China)

2010-09-15

To evaluate biological action of microorganism exposed to charged particles during the long distance space exploration, induction of inactivation and mutation in a red yeast strain Rhodotorula glutinis AY 91015 by carbon beams of different LET values (14.9-120.0 keV {mu}m{sup -1}) was investigated. It was found that survival curves were exponential, and mutation curves were linear for all LET values. The dependence of inactivation cross section on LET approached saturation near 120.0 keV {mu}m{sup -1}. The mutation cross section saturated when LET was higher than 58.2 keV {mu}m{sup -1}. Meanwhile, the highest RBE{sub i} for inactivation located at 120.0 keV {mu}m{sup -1} and the highest RBE{sub m} for mutation was at 58.2 keV {mu}m{sup -1}. The experiments imply that the most efficient mutagenic part of the depth dose profile of carbon ion is at the plateau region with intermediate LET value in which energy deposited is high enough to induce mutagenic lesions but too low to induce over kill effect in the yeast cells.

Moon 101: Introducing Students to Lunar Science and Exploration

Science.gov (United States)

Shaner, A. J.; Shipp, S. S.; Allen, J. S.; Kring, D. A.

2011-12-01

Moon 101 is designed with the purpose of familiarizing students with lunar geology and exploration. Armed with guiding questions, students read articles covering various lunar science topics and browse images from past and current lunar missions to familiarize themselves with available lunar data sets. Moon 101 was originally created for high school students preparing to conduct open-inquiry, lunar research. Most high school students' knowledge of lunar science is limited to lunar phases and tides, and their knowledge of lunar exploration is close to non-existent. Moon 101 provides a summary of the state of knowledge of the Moon's formation and evolution, and the exploration that has helped inform the lunar science community. Though designed for high school students, Moon 101 is highly appropriate for the undergraduate classroom, especially at the introductory level where resources for teaching lunar science are scarce. Moon 101 is comprised of two sections covering lunar science (formation and geologic evolution of the Moon) and one section covering lunar exploration. Students read information on the formation and geologic evolution of the Moon from sources such as the Planetary Science Research Discoveries (PSRD) website and the USGS professional paper A Geologic History of the Moon by Wilhelms. While these resources are not peer-reviewed journals, the information is presented at a level more advanced than articles from newspapers and popular science magazines. This ensures that the language is accessible to students who do not have a strong lunar/planetary science background, or a strong science background in general. Formation readings include information on older and current formation hypotheses, including the Giant Impact Hypothesis, the Magma Ocean hypothesis, and the age of the lunar crust. Lunar evolution articles describe ideas such as the Late Heavy Bombardment and geologic processes such as volcanism and impact cratering. After reading the articles

Design criteria for a hemispherical detector for LET measurements

International Nuclear Information System (INIS)

Schell, M.C.; DeLuca, P.M. Jr.; Pearson, D.W.; Attix, F.H.

1980-01-01

A detector for the direct measurement of the Linear Energy Transfer (LET) in cylindrical geometry was developed by Brandan and DeLuca. The detector successfully measured the LET of protons and a fraction of the heavy charged particles generated in cylindrical A150 plastic and graphite walls by 14.8 MeV neutrons. In this report, we present design tests for the hemispherical LET detector which will measure the LET of charged particles in spherical geometry and allow comparison with calculated LET spectra. The hemispherical LET detector will also provide a data base for radiobiological predictions with the Track Structure Model by Katz. A comparison of predictions of radiobiological effects by the Theory of Dual Radiation Action and the Track Structure Model by Edwards and the authors indicate that the Track Structure Model predicts cell survival as a function of dose more accurately and hence an additional motivation for the present construction of the hemispherical LET detector

Exploration of the Moon and Asteroids by Secondary Students

Science.gov (United States)

Shaner, A. J.; Bakerman, M. N.; Buxner, S.

2016-12-01

Since 2014, the Exploration of the Moon and Asteroids by Secondary Students, or ExMASS, program provides an opportunity for students to participate in authentic scientific research. The ExMASS program is an effort managed by the Center for Lunar Science and Exploration (CLSE). Led by the Lunar and Planetary Institute and Johnson Space Center, CLSE is one of nine teams comprising NASA's Solar System Exploration Research Virtual Institute (SSERVI). Over the course of one academic year, 10 teams of U.S. high school students conduct their own scientific investigations of Earth's Moon, or asteroids, with guidance from a scientist advisor. The program includes two elements: 1) two guided-inquiry introductory research activities that builds student knowledge of current lunar/asteroid science and lunar/asteroid data, and 2) an open-inquiry research project in which the students apply their knowledge to a self-defined project. Because the research is student-driven, it is not necessarily original research; original research is therefore not required. However, one team's research has been published in a professional journal. At the end of the school year, teams submit an abstract and research poster which are scored by a panel a judges. The top four scoring teams gather virtually to give short presentations to the judges. After presentations and time for Q&A, the judges choose one team to present in person at the Exploration Science Forum (ESF). The posters of all finalist schools are displayed at the ESF. The ExMASS program is evaluated by collecting data on changes in students' lunar/asteroid content knowledge, student attitudes toward science and science careers, and student perceptions of the processes of science in which their team participated. Exit surveys for teachers, students, and advisors are also distributed at the end of each program year to gather general feedback about the program and its impact. Results of this data from the first two years of the Ex

Relational Leading – Appreciating Letting Go, and Not Knowing Where You Are Going

DEFF Research Database (Denmark)

Larsen, Mette Vinther

2016-01-01

In this article we meet Steven,the manager of a Danish regional regional medical supply organization. With him, we explore how – even for leaders – it can feel liberating to let go of existing knowledge and understanding and embark on a journey with others with the certainty that no one knows where...

LET calibration for CR-39 detectors in different oxygen environments

International Nuclear Information System (INIS)

Zhou, D.; Semones, E.; Weyland, M.; Benton, E.R.

2007-01-01

High LET (linear energy transfer) radiation is the main contributor to the radiation field in low Earth orbit (LEO) in terms of dose equivalent. CR-39 plastic nuclear track detectors (PNTDs) can measure the LET spectrum and charge spectrum for the complicated radiation field in space. Previous research indicated that the sensitivity of CR-39 is different for CR-39 PNTDs working in different oxygen environments. LET calibration for CR-39 detectors in different oxygen environments is needed. Almost all the previous LET calibration work was carried out for CR-39 detectors in good-oxygen condition, LET calibration work for CR-39 in poor-oxygen condition has not been conducted until our work. Systematic LET calibrations were carried out by JSC-SRAG (Space Radiation Analysis Group) for CR-39 detectors working in different oxygen environments and abundant results of LET calibrations were obtained. This paper introduces the method for CR-39 LET calibration, presents and discusses the calibration results and some applications

Reflective Processes: A Qualitative Study Exploring Early Learning Student Teacher Mentoring Experiences in Student Teaching Practicums

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Barnes, Michelle M.

2013-01-01

This doctoral thesis explored mentoring in early learning teacher preparation programs. This study explored the reflective processes embedded in the work between student teachers and their mentors during early learning student teacher experiences at Washington State community and technical colleges. Schon's (1987a) concepts of…

Gene-expression profiling of Saccharomyces cerevisiae irradiated by high-LET radiations

Data.gov (United States)

National Aeronautics and Space Administration — Ionizing radiations are categorized by linear energy transfer (LET) into low-LET and high-LET. High-LET is considered to have a higher relative biological...

Precise let-7 expression levels balance organ regeneration against tumor suppression

Science.gov (United States)

Wu, Linwei; Nguyen, Liem H; Zhou, Kejin; de Soysa, T Yvanka; Li, Lin; Miller, Jason B; Tian, Jianmin; Locker, Joseph; Zhang, Shuyuan; Shinoda, Gen; Seligson, Marc T; Zeitels, Lauren R; Acharya, Asha; Wang, Sam C; Mendell, Joshua T; He, Xiaoshun; Nishino, Jinsuke; Morrison, Sean J; Siegwart, Daniel J; Daley, George Q; Shyh-Chang, Ng; Zhu, Hao

2015-01-01

The in vivo roles for even the most intensely studied microRNAs remain poorly defined. Here, analysis of mouse models revealed that let-7, a large and ancient microRNA family, performs tumor suppressive roles at the expense of regeneration. Too little or too much let-7 resulted in compromised protection against cancer or tissue damage, respectively. Modest let-7 overexpression abrogated MYC-driven liver cancer by antagonizing multiple let-7 sensitive oncogenes. However, the same level of overexpression blocked liver regeneration, while let-7 deletion enhanced it, demonstrating that distinct let-7 levels can mediate desirable phenotypes. let-7 dependent regeneration phenotypes resulted from influences on the insulin-PI3K-mTOR pathway. We found that chronic high-dose let-7 overexpression caused liver damage and degeneration, paradoxically leading to tumorigenesis. These dose-dependent roles for let-7 in tissue repair and tumorigenesis rationalize the tight regulation of this microRNA in development, and have important implications for let-7 based therapeutics. DOI: http://dx.doi.org/10.7554/eLife.09431.001 PMID:26445246

Being a young midwifery student: A qualitative exploration.

Science.gov (United States)

Fenwick, J; Cullen, D; Gamble, J; Sidebotham, M

2016-08-01

undergraduate midwifery programmes offer opportunities for school leavers and young people (aged less than 21 years) to enter the profession. There is limited research exploring this age groups experience of their Bachelor of Midwifery programme. In order to retain these students we need to ensure that their experiences of undertaking a Bachelor of Midwifery program are positive and barriers and challenges are minimised. this study explored young midwifery students' experience of their Bachelor of Midwifery program. a descriptive exploratory qualitative approach was used to explore the experiences of eleven students aged 20 years or less on enrolment. Data was collected using face-to-face or telephone-recorded interviews. Thematic analysis was used to analysis the data set. three major themes described the young students' experiences. The first labelled 'The challenges of being young' presented a number of age related challenges including transport issues with on-call commitments as some students had not gained a driver's license. Students experienced some degree of prejudice relating to their age from their older student peers and some clinical staff during placements. 'Finding your way' was the second theme and described the strategies students used to build confidence and competence both in the university and clinical environment. The young students reported a strong commitment to the profession. They demonstrated high levels of connection with women and found the continuity of care experiences invaluable to their learning. The final theme 'Making the transition from teenager to midwife' demonstrated some unique insights into how studying to become a midwife impacted upon their personal and professional growth. the young students in this study encountered some unique issues related to their age. However as they progressed through the program they developed confidence in themselves and visualised themselves as having a long midwifery career. They were strongly

Let's do comprehension 5-6

CERN Document Server

Brodie, Andrew

2015-01-01

Let's Do Comprehension is a brand new series of six titles in the popular 'Let's Do' range. Each book contains a rich variety of stimulating reading passages, accompanied by questions of varying difficulty. Designed to be used at home, each book includes tips and clues from Alice the Alligator as well as extra challenges in Brodie's Brain Boosters. There is a clear answer section for reference by parents and children, together with bright, colourful reward stickers.

Let's do comprehension 8-9

CERN Document Server

Brodie, Andrew

2015-01-01

Let's Do Comprehension is a brand new series of six titles in the popular 'Let's Do' range. Each book contains a rich variety of stimulating reading passages, accompanied by questions of varying difficulty. Designed to be used at home, each book includes tips and clues from Alice the Alligator as well as extra challenges in Brodie's Brain Boosters. There is a clear answer section for reference by parents and children, together with bright, colourful reward stickers.

Pri-let-7a-1 rs10739971 polymorphism is associated with gastric cancer prognosis and might affect mature let-7a expression

Directory of Open Access Journals (Sweden)

Li Y

2016-07-01

Full Text Available Ying Li, Qian Xu, Jingwei Liu, Caiyun He, Quan Yuan, Chengzhong Xing, Yuan Yuan Tumor Etiology and Screening Department of Cancer Institute and General Surgery, the First Affiliated Hospital of China Medical University, and Key Laboratory of Cancer Etiology and Prevention (China Medical University, Liaoning Provincial Education Department, Shenyang, People’s Republic of China Abstract: The relationship between the pri-let-7a-1 rs10739971 polymorphism and gastric cancer (GC risk has been reported. However, the role of this polymorphism in the prognosis of GC remains largely elusive. Sequenom MassARRAY platform method and the polymerase chain reaction (PCR-restriction fragment length polymorphism were used to investigate pri-let-7a-1 rs10739971 G→A in 334 GC patients. Real-time PCR detected expression of mature let-7a in serum and tissue. Patients with AA or GA+AA genotypes of the pri-let-7a-1 rs10739971 polymorphism demonstrated significantly longer survival time than those with the wild GG genotype. Stratified analysis indicated that survival time was significantly longer in women with AA or GA+AA genotypes and in Borrmann type I/II patients with GA heterozygote or GA+AA genotypes. AA genotype was more frequent in the lymphatic-metastasis-negative subgroup. Serum mature let-7a expression in healthy people with the GA heterozygote and the GA+AA genotype was higher than in those with the GG genotype, and the difference remained significant in the female healthy subgroup. Pri-let-7a-1 rs10739971 polymorphism might be a biomarker for GC prognosis, especially for female and Borrmann type I/II patients. The pri-let-7a-1 rs10739971 polymorphism might affect serum mature let-7a expression, and partly explain the mechanism of the relationship between the pri-let-7a-1 rs10739971 polymorphism and GC survival. Keywords: miRNA, let-7a, polymorphism, gastric cancer, prognosis, expression

The Lin28/let-7 axis regulates glucose metabolism

Science.gov (United States)

Zhu, Hao; Shyh-Chang, Ng; Segrè, Ayellet V.; Shinoda, Gen; Shah, Samar P.; Einhorn, William S.; Takeuchi, Ayumu; Engreitz, Jesse M.; Hagan, John P.; Kharas, Michael G; Urbach, Achia; Thornton, James E.; Triboulet, Robinson; Gregory, Richard I.; Altshuler, David; Daley, George Q.

2012-01-01

SUMMARY The let-7 tumor suppressor microRNAs are known for their regulation of oncogenes, while the RNA-binding proteins Lin28a/b promote malignancy by blocking let-7 biogenesis. In studies of the Lin28/let-7 pathway, we discovered unexpected roles in regulating metabolism. When overexpressed in mice, both Lin28a and LIN28B promoted an insulin-sensitized state that resisted high fat diet-induced diabetes, whereas muscle-specific loss of Lin28a and overexpression of let-7 resulted in insulin resistance and impaired glucose tolerance. These phenomena occurred in part through let-7-mediated repression of multiple components of the insulin-PI3K-mTOR pathway, including IGF1R, INSR, and IRS2. The mTOR inhibitor rapamycin abrogated the enhanced glucose uptake and insulin-sensitivity conferred by Lin28a in vitro and in vivo. In addition, we found that let-7 targets were enriched for genes that contain SNPs associated with type 2 diabetes and fasting glucose in human genome-wide association studies. These data establish the Lin28/let-7 pathway as a central regulator of mammalian glucose metabolism. PMID:21962509

Blood-letting in anorexia nervosa: a case study.

Science.gov (United States)

Morgan, J F; Lacey, J H

2000-05-01

Deliberate blood-letting has been characterized as an alternative to purging behavior in bulimia. We describe a female healthcare worker with an 8-year history of restrictive anorexia nervosa, who initially presented with anemia, using blood-letting, cold baths, and starvation to control her mental state. In contrast with the previous cases of bulimia, the aim of blood-letting in this case of anorexia nervosa was to achieve anemia. She compared the psychic correlates of anemia to emaciation, rather than to deliberate self-harm or purging. We note that mainstream 19th century psychiatry prescribed "baths, blood-letting and diet" as a treatment of "madness." Copyright 2000 by John Wiley & Sons, Inc.

Stakeholders' Opinions on "Let the Schools Become Life" Project in Scope of Lifelong Learning Activities

Science.gov (United States)

Karatas, Süleyman

2015-01-01

The objective of this study is to find out the opinions of school administrators, teachers, staff, benefiting students and parents and other stakeholders of "Let the Schools Become Life" project being carried out in order to reveal the effectiveness and efficiency of the project. Data in this qualitative research was gathered by…

The Lin28/let-7 Axis Regulates Glucose Metabolism

NARCIS (Netherlands)

Zhu, Hao; Shyh-Chang, Ng; Segre, Ayellet V.; Shinoda, Gen; Shah, Samar P.; Einhorn, William S.; Takeuchi, Ayumu; Engreitz, Jesse M.; Hagan, John P.; Kharas, Michael G.; Urbach, Achia; Thornton, James E.; Triboulet, Robinson; Gregory, Richard I.; Altshuler, David; Daley, George Q.

2011-01-01

The let-7 tumor suppressor microRNAs are known for their regulation of oncogenes, while the RNA-binding proteins Lin28a/b promote malignancy by inhibiting let-7 biogenesis. We have uncovered unexpected roles for the Lin28/let-7 pathway in regulating-metabolism. When overexpressed in mice, both

The Impact of Career Exploration upon the Success of Underrepresented Students in Higher Education

Science.gov (United States)

Blair, Elaine J.

2012-01-01

Factors that contribute to college student success are multiple. Career exploration as a student success strategy was explored in this study. The purpose of this exploratory mixed-methods study was to explore whether there was a relationship between career exploration and the success of underrepresented students in higher education. Quantitative…

Letting die: A moral defence | Adenugba | Sophia: An African ...

African Journals Online (AJOL)

This paper draws a distinction between letting die and active euthanasia. It argues that there is a moral difference between letting die and active euthanasia which strictly intends to cause death. The difference between letting die and active euthanasia lies in intention though intention in both cases can be said to be ...

The dependence of relative biological effectiveness from LET

International Nuclear Information System (INIS)

Savich, A.V.

1985-01-01

A dependence of radiation-chemical yields of DNA injuries on the LET value is found for two transformations - one and two-strand breaks of it. It is shown that the yield of one-strand breaks decreases with the increase of LET value, and the quantity of two-strand breaks at first increases reaching the maximum value within the LET range from 100 up to 150 eV/nm and then decreases. The considered semiempiric theories of the RBE dependences on LET permits using the experimentally determined parameters characterizing radiosensitivity, to estimate the efficiency of the effect of ionizing radiation on cells at different doses, types of radiation and levels of saturation with oxygen. The stage of the cell cycle is also taken into account

Exploring the Solar System? Let the Math Teachers Help!

Science.gov (United States)

Charles, Karen; Canales, J. D.; Smith, Angela; Zimmerman, Natalie

2012-01-01

Scale measurement and ratio and proportion are topics that fall clearly in the middle-grades mathematics curriculum in Texas. So does the solar system. In their experience, the authors have found that students have trouble manipulating, much less comprehending, very large numbers and very small numbers. These concepts can be brought into students'…

Teacher-student contact : Exploring a basic but complicated concept

NARCIS (Netherlands)

Korthagen, Fred A J; Attema-Noordewier, Saskia; Zwart, Rosanne C.

2014-01-01

Contact is fundamental to teacher-student relationships, but empirical studies or theoretical frameworks on teacher-student contact are rare. This article describes a theoretical and empirical exploration aimed at building such a framework. In two studies using classroom observations and interviews

Let G be a group

DEFF Research Database (Denmark)

Lützen, Jesper

2015-01-01

I moderne formalistisk matematik er ontologi blevet erstattet med spørgsmålet om konsistens af et aksiomatisk system. I artiklen gøres der rede for hvordan denne opfattelse er blevet til og denne historie opfattes i sig selv som en slags erstatning for ontologi......I moderne formalistisk matematik er ontologi blevet erstattet med spørgsmålet om konsistens af et aksiomatisk system. I artiklen gøres der rede for hvordan denne opfattelse er blevet til og denne historie opfattes i sig selv som en slags erstatning for ontologi...

Identification of let-7-regulated oncofetal genes

DEFF Research Database (Denmark)

Boyerinas, Benjamin; Park, Sun-Mi; Shomron, Noam

2008-01-01

-regulated at the end of embryonic development. Let-7 is often down-regulated early during cancer development, suggesting that let-7-regulated oncofetal genes (LOG) may become reexpressed in cancer cells. Using comparative bioinformatics, we have identified 12 conserved LOGs that include HMGA2 and IMP-1/CRD-BP. IMP-1...

A Post-Intentional Exploration of Agnostic College Students' Experiences

Science.gov (United States)

Armstrong, Amanda

2017-01-01

Scholars have adapted college student identity development models to examine and highlight the unique, laborious, and varied experiences of marginalized populations. However, researchers have minimally explored the perspectives of nontheistic and nonreligious college students using poststructural methodologies. I followed a post-intentional…

In vitro RBE-LET dependence for multiple particle types

DEFF Research Database (Denmark)

Sørensen, Brita Singers; Overgaard, Jens; Bassler, Niels

2011-01-01

Background. In vitro RBE values for various high LET radiation types have been determined for many different cell types. Occasionally it is criticized that RBE for a given endpoint cannot be single-value dependent on LET alone, but also on particle species, due to the different dose deposition...... profiles on microscopic scale. Hence LET is not sufficient as a predictor of RBE, and this is one of the motivations for development of radiobiological models which explicitly depend on the detailed particle energy spectrum of the applied radiation field. The aim of the present study is to summarize...... the available data in the literature regarding the dependency of RBE on LET for different particles. Method. As RBE is highly dependent on cell type and endpoint, we discriminated the RBE-LET relationship for the three investigated cell lines and at the same endpoint (10% survival in colony formation). Data...

Career exploration behavior of Korean medical students

OpenAIRE

Hyejin An; Seung-Hee Lee

2017-01-01

Purpose This study is to analyze the effects of medical students? social support and career barriers on career exploration behavior mediated by career decision-making self-efficacy. Methods We applied the t-test to investigate the difference among the variables based on gender and admission types. Also, we performed path analysis to verify the effect of perceived career barriers and social support on career exploration behavior with career decision efficacy as a mediator. Results First, we no...

Letting Your Students "Fly" in the Classroom.

Science.gov (United States)

Adams, Thomas

1997-01-01

Students investigate the concept of motion by making simple paper airplanes and flying them in the classroom. Students are introduced to conversion factors to calculate various speeds. Additional activities include rounding decimal numbers, estimating, finding averages, making bar graphs, and solving problems. Offers ideas for extension such as…

A Review: Some biological effects of high LET radiations

Science.gov (United States)

Wiley, A., Jr.

1972-01-01

There are qualitative and quantitative differences in the biological damage observed after exposure to high LET radiation as compared to that caused by low LET radiations. This review is concerned with these differences, which are ultimately reflected at the biochemical, cellular and even whole animal levels. In general, high LET radiations seem to produce biochemical damage which is more severe and possibly less repairable. Experimental data for those effects are presented in terms of biochemical RBE's with consideration of both early and late manifestations. An LET independent process by which significant biochemical damage may result from protons, neutrons and negative pion mesons is discussed.

Owning, letting and demanding second homes

DEFF Research Database (Denmark)

Bloze, Gintautas; Skak, Morten

register data and presents estimations of the probability of owning a second home, the decision to let the second home and the number of let weeks per year. Also income elasticities for primary and second housing demand are estimated. We find a conventional monotonic increase in demand elasticities...... for primary housing demand for non-owners of second homes; however, owners of second homes have the highest income elasticity in the middle income group....

The inactivation of papain by high LET radiations

International Nuclear Information System (INIS)

Bisby, R.H.; Cundall, R.B.; Sims, H.E.; Burns, W.G.

1984-01-01

The effect of varying LET over a wide range (0.2-1570 eV/nm) on the radiation-induced inactivation of the enzyme papain in dilute aqueous solution has been investigated. Measurements of total, reparable and non-reparable inactivation G values in oxygen, nitrous oxide and argon saturated solutions have allowed the contributions to inactivation from radicals and hydrogen peroxide to be evaluated. At high LET the results demonstrate an increasing component due to reaction of the superoxide radical, formed from oxygen produced in the track as a primary radiolysis product. This effect was not observed in our previous study with ribonuclease due to the insensitivity of ribonuclease to inactivation by superoxide and hydrogen peroxide. The results obtained with papain clearly demonstrate a maximum in G(H 2 O 2 ) at an LET of equivalent to 140 eV/nm. Generation of O 2 within the track as a primary radiolysis product at high LET now appears to be confirmed as an important mechanism leading to reduction in the oxygen enhancement ratio for cellular systems exposed to high LET radiations (Baverstock and Burns 1981). (author)

Internship training in computer science: Exploring student satisfaction levels.

Science.gov (United States)

Jaradat, Ghaith M

2017-08-01

The requirement of employability in the job market prompted universities to conduct internship training as part of their study plans. There is a need to train students on important academic and professional skills related to the workplace with an IT component. This article describes a statistical study that measures satisfaction levels among students in the faculty of Information Technology and Computer Science in Jordan. The objective of this study is to explore factors that influence student satisfaction with regards to enrolling in an internship training program. The study was conducted to gather student perceptions, opinions, preferences and satisfaction levels related to the program. Data were collected via a mixed method survey (surveys and interviews) from student-respondents. The survey collects demographic and background information from students, including their perception of faculty performance in the training poised to prepare them for the job market. Findings from this study show that students expect internship training to improve their professional and personal skills as well as to increase their workplace-related satisfaction. It is concluded that improving the internship training is crucial among the students as it is expected to enrich their experiences, knowledge and skills in the personal and professional life. It is also expected to increase their level of confidence when it comes to exploring their future job opportunities in the Jordanian market. Copyright © 2017 Elsevier Ltd. All rights reserved.

Exploring the Drinking/Driving Behaviors and Attitudes of College Students.

Science.gov (United States)

Geller, E. Scott

While there is little research specifically dealing with college students and drunk driving, there is ample evidence of frequent, heavy drinking by students. A series of projects was undertaken to explore college students' drinking behavior and attitudes related to alcohol-impaired driving. These projects included: (1) analysis of behavioral…

Exploring Language Awareness through Students' Engagement in Language Play

Science.gov (United States)

Ahn, So-Yeon

2016-01-01

The present study explores Korean students' demonstration of language awareness through their engagement in language play. Grounded in the understanding of the relationship between language play and an "engagement with language" (EWL) perspective, this ethnographic and discourse analytic study investigates how Korean students aged 11-15…

The Role of Classroom Characteristics for Students' Motivation and Career Exploration

Science.gov (United States)

Lazarides, Rebecca; Rohowski, Susanne; Ohlemann, Svenja; Ittel, Angela

2016-01-01

This study focused on students enrolled in obligatory vocational education courses in German secondary schools that aim to support students' career exploration. The study examined the relations between student-perceived classroom characteristics (support for autonomy, competence and relatedness), students' intrinsic motivation and their career…

High and Low LET Radiation Differentially Induce Normal Tissue Damage Signals

International Nuclear Information System (INIS)

Niemantsverdriet, Maarten; Goethem, Marc-Jan van; Bron, Reinier; Hogewerf, Wytse; Brandenburg, Sytze; Langendijk, Johannes A.; Luijk, Peter van; Coppes, Robert P.

2012-01-01

Purpose: Radiotherapy using high linear energy transfer (LET) radiation is aimed at efficiently killing tumor cells while minimizing dose (biological effective) to normal tissues to prevent toxicity. It is well established that high LET radiation results in lower cell survival per absorbed dose than low LET radiation. However, whether various mechanisms involved in the development of normal tissue damage may be regulated differentially is not known. Therefore the aim of this study was to investigate whether two actions related to normal tissue toxicity, p53-induced apoptosis and expression of the profibrotic gene PAI-1 (plasminogen activator inhibitor 1), are differentially induced by high and low LET radiation. Methods and Materials: Cells were irradiated with high LET carbon ions or low LET photons. Cell survival assays were performed, profibrotic PAI-1 expression was monitored by quantitative polymerase chain reaction, and apoptosis was assayed by annexin V staining. Activation of p53 by phosphorylation at serine 315 and serine 37 was monitored by Western blotting. Transfections of plasmids expressing p53 mutated at serines 315 and 37 were used to test the requirement of these residues for apoptosis and expression of PAI-1. Results: As expected, cell survival was lower and induction of apoptosis was higher in high -LET irradiated cells. Interestingly, induction of the profibrotic PAI-1 gene was similar with high and low LET radiation. In agreement with this finding, phosphorylation of p53 at serine 315 involved in PAI-1 expression was similar with high and low LET radiation, whereas phosphorylation of p53 at serine 37, involved in apoptosis induction, was much higher after high LET irradiation. Conclusions: Our results indicate that diverse mechanisms involved in the development of normal tissue damage may be differentially affected by high and low LET radiation. This may have consequences for the development and manifestation of normal tissue damage.

Exploring International Students' Food Choices Using Photovoice Techniques

Science.gov (United States)

Corcoran, Nova

2018-01-01

This study aimed to explore international student food choices in a semirural setting using participatory photovoice techniques. Eighteen international students took photographs over 7-10 days of a typical food week and then attended a workshop where they completed three photography display and captioning tasks. Ten themes emerged linked to the…

Biomarkers specific to densely-ionising (high LET) radiations

International Nuclear Information System (INIS)

Brenner, D.J.; Okladnikova, N.; Hande, P.; Burak, L.; Geard, C.R.; Azizova, T.

2001-01-01

There have been several suggestions of biomarkers that are specific to high LET radiation. Such a biomarker could significantly increase the power of epidemiological studies of individuals exposed to densely-ionising radiations such as alpha particles (e.g. radon, plutonium workers, individuals exposed to depleted uranium) or neutrons (e.g. radiation workers, airline personnel). We discuss here a potentially powerful high LET biomarker (the H value) which is the ratio of induced inter-chromosomal aberrations to intra-arm aberrations. Both theoretical and experimental studies have suggested that this ratio should differ by a factor of about three between high LET radiation and any other likely clastogen, and will yield more discrimination than the previously suggested F value (ratio of inter-chromosomal aberrations to intra-chromosomal inter-arm aberrations). Evidence of the long-term stability of such chromosomal biomarkers has also been generated. Because these stable intra-arm and inter-chromosomal aberrations are (1) frequent and (2) measurable at long times after exposure, this H value appears to be a practical biomarker of high LET exposure, and several in vitro studies have confirmed the approach for unstable aberrations. The approach is currently being tested in a population of Russian radiation workers exposed several decades ago to high- or low LET radiation. (author)

Exploring the extent to which ELT students utilise smartphones for ...

African Journals Online (AJOL)

Zehra

2015-11-09

Nov 9, 2015 ... aimed to explore the extent to which English Language Teaching (ELT) students utilise ... Given the fact that almost all students have a personal smartphone, and use it ..... ears as a disadvantage for smartphones (Kétyi,.

Career exploration behavior of Korean medical students

Directory of Open Access Journals (Sweden)

Hyejin An

2017-09-01

Full Text Available Purpose This study is to analyze the effects of medical students’ social support and career barriers on career exploration behavior mediated by career decision-making self-efficacy. Methods We applied the t-test to investigate the difference among the variables based on gender and admission types. Also, we performed path analysis to verify the effect of perceived career barriers and social support on career exploration behavior with career decision efficacy as a mediator. Results First, we noted statistically significant gender and admission type difference in social support, career barriers and career exploration behaviors. Second, social support and career barriers were found to influence career exploration behavior as a mediating variable for career decision-making self-efficacy. Conclusion Social support and career barriers as perceived by medical students influenced their career exploration behavior, with their decision-making self-efficacy serving as a full mediator. Therefore, this study has educational implications for career program development and educational training for career decision-making self-efficacy.

Exploring students' patterns of reasoning

Science.gov (United States)

Matloob Haghanikar, Mojgan

As part of a collaborative study of the science preparation of elementary school teachers, we investigated the quality of students' reasoning and explored the relationship between sophistication of reasoning and the degree to which the courses were considered inquiry oriented. To probe students' reasoning, we developed open-ended written content questions with the distinguishing feature of applying recently learned concepts in a new context. We devised a protocol for developing written content questions that provided a common structure for probing and classifying students' sophistication level of reasoning. In designing our protocol, we considered several distinct criteria, and classified students' responses based on their performance for each criterion. First, we classified concepts into three types: Descriptive, Hypothetical, and Theoretical and categorized the abstraction levels of the responses in terms of the types of concepts and the inter-relationship between the concepts. Second, we devised a rubric based on Bloom's revised taxonomy with seven traits (both knowledge types and cognitive processes) and a defined set of criteria to evaluate each trait. Along with analyzing students' reasoning, we visited universities and observed the courses in which the students were enrolled. We used the Reformed Teaching Observation Protocol (RTOP) to rank the courses with respect to characteristics that are valued for the inquiry courses. We conducted logistic regression for a sample of 18courses with about 900 students and reported the results for performing logistic regression to estimate the relationship between traits of reasoning and RTOP score. In addition, we analyzed conceptual structure of students' responses, based on conceptual classification schemes, and clustered students' responses into six categories. We derived regression model, to estimate the relationship between the sophistication of the categories of conceptual structure and RTOP scores. However, the

Exploring the Use of Tablets for Student Teaching Supervision

Science.gov (United States)

Johnson, Joseph A.; Wesley, Whitney M.; Yerrick, Randy

2016-01-01

While research on the use of tablets in the field of education is emerging, existing research on the use of this tool for the purposes of student teaching supervision is very limited. This study aimed to explore the application of iPad tablets for student teacher supervision in a teacher preparation program at a large state university in the…

In vitro cellular transformation induced by charged particles of defined LET

International Nuclear Information System (INIS)

Hei, T.K.; Hall, E.J.; Komatsu, K.; Goldhagen, P.

1985-01-01

Cytotoxicity and neoplastic transformation were scored in the C/sub 3/H 10T1/2 cell system following irradiation with protons, deuterons and helium-3 ions of defined LET in the track segment mode. The charged particles were accelerated at the Radiological Research Accelerator Facility at the Nevis Laboratories of Columbia University and provided a range of LET values from 10 to 175 keV/μm. Exponential phase cultures of C3H 10T1/2 cells, growing on a thin mylar surface were irradiated with charged particles of various LET values and subsequently replated onto commercial plastic petri dishes. The cultures were incubated for six weeks at which time they were fixed, stained and type II and III scored as transformants. Over the range of LET values studied thus far, it was found that as the LET of the charged particles increased, the shoulder of the survival curves decreased and approached an exponential function of dose at LET values of 100 keV/μm and above. The transformation incidence, likewise, showed a direct correlation with LET over the dose ranges examined

Exploring student teachers' views of science process skills in their ...

African Journals Online (AJOL)

2016-08-18

Aug 18, 2016 ... The purpose of this study was to explore the views of student teachers with regard to the importance they attach to these skills ... and purpose of practical work in science. .... students learn how to use some piece(s) of scientific.

Exploring Native American Students' Perceptions of Scientists

Science.gov (United States)

Laubach, Timothy A.; Crofford, Geary Don; Marek, Edmund A.

2012-07-01

The purpose of this descriptive study was to explore Native American (NA) students' perceptions of scientists by using the Draw-A-Scientist Test and to determine if differences in these perceptions exist between grade level, gender, and level of cultural tradition. Data were collected for students in Grades 9-12 within a NA grant off-reservation boarding school. A total of 133 NA students were asked to draw a picture of a scientist at work and to provide a written explanation as to what the scientist was doing. A content analysis of the drawings indicated that the level of stereotype differed between all NA subgroups, but analysis of variance revealed that these differences were not significant between groups except for students who practised native cultural tradition at home compared to students who did not practise native cultural tradition at home (p educational and career science, technology, engineering, and mathematics paths in the future. The educational implication is that once initial perceptions are identified, researchers and teachers can provide meaningful experiences to combat the stereotypes.

Multiple mechanisms disrupt the let-7 microRNA family in neuroblastoma

Science.gov (United States)

Powers, John T; Tsanov, Kaloyan M; Pearson, Daniel S; Roels, Frederik; Spina, Catherine S; Ebright, Richard; Seligson, Marc; de Soysa, Yvanka; Cahan, Patrick; Theiβen, Jessica; Tu, Ho-Chou; Han, Areum; Kurek, Kyle C; LaPier, Grace S; Osborne, Jihan K; Ross, Samantha J; Cesana, Marcella; Collins, James J; Berthold, Frank; Daley, George Q

2016-01-01

Poor prognosis in neuroblastoma is associated with genetic amplification of MYCN. MYCN is itself a target of let-7, a tumor suppressor family of microRNAs implicated in numerous cancers. LIN28B, an inhibitor of let-7 biogenesis, is overexpressed in neuroblastoma and has been reported to regulate MYCN. However, here we show that LIN28B is dispensable in MYCN-amplified neuroblastoma cell lines, despite de-repression of let-7. We further demonstrate that MYCN mRNA levels in amplified disease are exceptionally high and sufficient to sponge let-7, which reconciles the dispensability of LIN28B. We found that genetic loss of let-7 is common in neuroblastoma, inversely associated with MYCN-amplification, and independently associated with poor outcomes, providing a rationale for chromosomal loss patterns in neuroblastoma. We propose that let-7 disruption by LIN28B, MYCN sponging, or genetic loss is a unifying mechanism of neuroblastoma pathogenesis with broad implications for cancer pathogenesis. PMID:27383785

Career exploration in Mozambique : exploratory study with secondary students

OpenAIRE

Ussene, Camilo; Taveira, Maria do Céu

2009-01-01

This article is part of a larger research project on the evaluation of career intervention needs in Mozambique. It consists of an exploratory study of the career exploration process of Mozambican students attending the 12th grade. The results of the construct validity and clustering analyses of the responses to the Career Exploration Survey (CES; Stumpf, Colarelli, & Hartman, 1983) are discussed, in the light of the career exploration theory and empirical research, namely the cognitive-motiva...

Exploring Nursing Students' Experiences of Learning Using Phenomenography: A Literature Review.

Science.gov (United States)

Barry, Sinead; Ward, Louise; Walter, Ruby

2017-10-01

The purpose of this extensive international and national literature review was to explore how phenomenography identifies nursing students' experiences of learning within preregistration (or prelicensure) nursing education. Data were collected utilizing a comprehensive search of electronic databases. Full text, peer-reviewed, and scholarly articles published in English using the search terms phenomengraph*, nurs*, student, education, and learning were reviewed. Two discreet themes emerged exploring students' experiences of learning within preregistration nursing education: (a) Phenomenography was a beneficial method to expose variation in students' understandings of a challenging concept or topic and (b) phenomenography was beneficial to evaluate teaching methods in attempt to improve student learning of challenging and complex concepts. On the basis of these findings, future research utilizing phenomenography within nursing education has potential to uncover variation in students' understandings of mental health, with future consideration of implications to nursing curriculum design and development. [J Nurs Educ. 2017;56(10):591-598.]. Copyright 2017, SLACK Incorporated.

Applicability of LET to single events in microelectronic structures

Science.gov (United States)

Xapsos, Michael A.

1992-12-01

LET is often used as a single parameter to determine the energy deposited in a microelectronic structure by a single event. The accuracy of this assumption is examined for ranges of ion energies and volumes of silicon appropriate for modern microelectronics. It is shown to be accurate only under very restricted conditions. Significant differences arise because (1) LET is related to energy lost by the ion, not energy deposited in the volume; and (2) LET is an average value and does not account for statistical variations in energy deposition. Criteria are suggested for determining when factors other than LET should be considered, and new analytical approaches are presented to account for them. One implication of these results is that improvements can be made in space upset rate predictions by incorporating the new methods into currently used codes such as CREME and CRUP.

MicroRNA let-7, T cells, and patient survival in colorectal cancer

Science.gov (United States)

Dou, Ruoxu; Nishihara, Reiko; Cao, Yin; Hamada, Tsuyoshi; Mima, Kosuke; Masuda, Atsuhiro; Masugi, Yohei; Shi, Yan; Gu, Mancang; Li, Wanwan; da Silva, Annacarolina; Nosho, Katsuhiko; Zhang, Xuehong; Meyerhardt, Jeffrey A.; Giovannucci, Edward L.; Chan, Andrew T.; Fuchs, Charles S.; Qian, Zhi Rong; Ogino, Shuji

2016-01-01

Experimental evidence suggests that the let-7 family of noncoding RNAs suppresses adaptive immune responses, contributing to immune evasion by the tumor. We hypothesized that the amount of let-7a and let-7b expression in colorectal carcinoma might be associated with limited T-lymphocyte infiltrates in the tumor microenvironment and worse clinical outcome. Utilizing the molecular pathological epidemiology resources of 795 rectal and colon cancers in two U.S.-nationwide prospective cohort studies, we measured tumor-associated let-7a and let-7b expression levels by quantitative reverse-transcription PCR, and CD3+, CD8+, CD45RO (PTPRC)+, and FOXP3+ cell densities by tumor tissue microarray immunohistochemistry and computer-assisted image analysis. Logistic regression analysis and Cox proportional hazards regression were used to assess associations of let-7a (and let-7b) expression (quartile predictor variables) with T-cell densities (binary outcome variables) and mortality, respectively, controlling for tumor molecular features, including microsatellite instability, CpG island methylator phenotype, LINE-1 methylation, and KRAS, BRAF, and PIK3CA mutations. Compared with cases in the lowest quartile of let-7a expression, those in the highest quartile were associated with lower densities of CD3+ [multivariate odds ratio (OR), 0.40; 95% confidence interval (CI), 0.23 to 0.67; Ptrend = 0.003] and CD45RO+ cells (multivariate OR, 0.31; 95% CI, 0.17 to 0.58; Ptrend = 0.0004), and higher colorectal cancer-specific mortality (multivariate hazard ratio, 1.82; 95% CI, 1.42 to 3.13; Ptrend = 0.001). In contrast, let-7b expression was not significantly associated with T-cell density or colorectal cancer prognosis. Our data support the role of let-7a in suppressing antitumor immunity in colorectal cancer, and suggest let-7a as a potential target of immunotherapy. PMID:27737877

A mixed-methods study exploring student nurses’ understanding of futile CPR

OpenAIRE

Batty, Emma

2014-01-01

Abstract Background: Futile CPR has the potential to inflict significant, avoidable harms on dying patients. Futile CPR is widely debated in the literature, but there is little research into futile CPR in the context of nursing. There are no published studies exploring student nurses’ understanding of futile CPR. Aim: To explore student nurses’ understanding of futile CPR Methods: A mixed methods study, using questionnaires to establish background data and identify prominent issues. ...

Student-Produced Podcasts in Language Learning – Exploring Student Perceptions of Podcast Activities

Directory of Open Access Journals (Sweden)

Birgit Phillips

2017-12-01

Full Text Available Podcasts are a useful tool for developing speaking skills in language acquisition settings, particularly within the context of the emerging Mobile Assisted Language Learning (MALL. While much research has emphasized the effectiveness of teacher-produced podcasts, this study seeks to address the gap in knowledge on student-generated podcasts in language learning. In addition to highlighting some of the main pedagogical considerations of using podcasts in language learning, this paper explores students’ perceptions of podcasts as a learning tool. To this end, this study describes the results of two surveys which were conducted with two different student cohorts over the course of two years. The surveys explored the students’ levels of acceptance and enjoyment of activities in which they had to produce their own podcasts, as well as the perceived learning benefits. The discussion section describes a range of positive learning outcomes and highlights the pedagogical implications of using podcasts in class. The paper concludes with some practical suggestions for the effective use of student-generated podcast activities in the language classroom.

Biological fingerprint of high LET radiation. Brenner hypothesis

International Nuclear Information System (INIS)

Kodama, Yoshiaki; Awa, Akio; Nakamura, Nori

1997-01-01

Hypothesis by Brenner et al. (1994) that in chromosome aberrations in human peripheral lymphocytes induced by radiation exposure, F value (dicentrics/rings) differs dependently on the LET and can be a biomarker of high LET radiation like neutron and α-ray was reviewed and evaluated as follows. Radiation and chromosome aberrations; in this section, unstable aberrations like dicentric and rings (r) and stable ones like translocation and pericentric inversions were described. F value. Brenner hypothesis. Bauchinger's refutation. F value determined by FISH method; here, FISH is fluorescence in situ hybridization. F value in studies by author's Radiation Effect Research Facility. Frequency of chromosome aberration in A-bomb survivors and ESR (ESR: electron spin resonance). The cause for fluctuation of F values. The Brenner hypothesis could not be supported by studies by author's facility, suggesting that the rate of inter-chromosomal and intra-chromosomal exchange abnormalities can not be distinguishable by the radiation LET. This might be derived from the difference in detection technology of r rather than in LET. (K.H.)

Special photographic emulsions for high LET dosimetry

International Nuclear Information System (INIS)

Katz, R.

1978-12-01

The purpose of these investigations into photographic emulsion dosimetry is to attempt to use the photographic emulsion to mimic the response of human tissues to high LET radiations. The program therefore requires that a systematic understanding of the response of mammalian cells to ionizing radiations be achieved. We have been concerned with differences in RBE and in radiation response to both high and LET radiations, and in the interrelationship between observations with these different radiations

Are you a developer? Let's talk!

CERN Multimedia

CERN. Geneva

2014-01-01

Many of us have to create software as part of our work, if you do probably you asked yourself some of the following: How other people at CERN develop? What technologies have they used? What worked and what didn't for them? Am I reinventing the wheel? What CERN services can make my life easier? What other services I miss that would be useful to have? How can I integrate my system with XXYY at CERN? Unfortunately there is little communication between us and we need to fix that, let's find initiatives to improve and share experiences between software engineers... let's talk!

Digital Downsides: Exploring University Students' Negative Engagements with Digital Technology

Science.gov (United States)

Selwyn, Neil

2016-01-01

Digital technologies are now an integral feature of university study. As such, academic research has tended to concentrate on the potential of digital technologies to support, extend and even "enhance" student learning. This paper, in contrast, explores the rather more messy realities of students' engagements with digital technology. In…

LET dependence of scintillation yields in liquid argon

Energy Technology Data Exchange (ETDEWEB)

Doke, Tadayoshi; Hitachi, Akira; Kikuchi, Jun; Crawford, H J; Lindstrom, P J; Masuda, Kimiaki; Shibamura, Eido; Takahashi, Tan

1988-06-01

Scintillation yields (scintillation intensity per unit absorbed energy) in liquid argon for ionizing particles are reviewed as a function of LET for the particles. The maximum scintillation yield, which is obtained for relativistic heavy ions from Ne to La, is about 1.2 times larger than that for gamma rays in NaI(Tl) crystal. In the low LET region, the scintillation yields for relativistic electrons, protons and He ions are 10-20% lower than the maximum yield. This tendency can be explained by taking into account the existence of the electrons which have escaped from their parent ions. In the high LET region, a quenching effect due to high ionization density is observed for alpha particles, fission fragments and relativistic Au ions.

"Let's Move" campaign: applying the extended parallel process model.

Science.gov (United States)

Batchelder, Alicia; Matusitz, Jonathan

2014-01-01

This article examines Michelle Obama's health campaign, "Let's Move," through the lens of the extended parallel process model (EPPM). "Let's Move" aims to reduce the childhood obesity epidemic in the United States. Developed by Kim Witte, EPPM rests on the premise that people's attitudes can be changed when fear is exploited as a factor of persuasion. Fear appeals work best (a) when a person feels a concern about the issue or situation, and (b) when he or she believes to have the capability of dealing with that issue or situation. Overall, the analysis found that "Let's Move" is based on past health campaigns that have been successful. An important element of the campaign is the use of fear appeals (as it is postulated by EPPM). For example, part of the campaign's strategies is to explain the severity of the diseases associated with obesity. By looking at the steps of EPPM, readers can also understand the strengths and weaknesses of "Let's Move."

Exploring the cultural competence of undergraduate nursing students in Saudi Arabia.

Science.gov (United States)

Halabi, Jehad O; de Beer, Jennifer

2018-03-01

To explore the cultural competence of undergraduate nursing students at a college of nursing, Saudi Arabia. A descriptive exploratory design was used to explore the Saudi undergraduate nursing students' level of cultural competency. The convenience sample included 205 nursing students affiliated with a college of nursing at a health science university in Jeddah, Saudi Arabia. Data was collected using the Inventory for Assessing the Process of Cultural Competence-Revised (IAPCC-R) consisting of 25 items. The tool reported acceptable reliability of Cronbach alpha 0.89. The majority of students were culturally aware and dealt with people from different cultures. One-third preferred to have training on culture over a period of time. Half the students preferred studying a special course related to working with people from different cultures. Cultural desire reported the highest mean while cultural knowledge scored the lowest among the cultural competence subscales despite students being exposed to some cultural knowledge content in their training. Implementing the guidelines for culturally competent care assure covering all aspects of care with consideration of cultural heritage as a main concept. Comparative study of nurses' and students' perception is further recommended. Copyright © 2017 Elsevier Ltd. All rights reserved.

Complexity in Simplicity: Flexible Agent-based State Space Exploration

DEFF Research Database (Denmark)

Rasmussen, Jacob Illum; Larsen, Kim Guldstrand

2007-01-01

In this paper, we describe a new flexible framework for state space exploration based on cooperating agents. The idea is to let various agents with different search patterns explore the state space individually and communicate information about fruitful subpaths of the search tree to each other...

Mutagenic action of radiation with different LET on Bacillus subtilis cells

International Nuclear Information System (INIS)

edinennyj Inst. Yadernykh Issledovanij, Dubna (Russian Federation))" data-affiliation=" (Obedinennyj Inst. Yadernykh Issledovanij, Dubna (Russian Federation))" >Borejko, A.V.; edinennyj Inst. Yadernykh Issledovanij, Dubna (Russian Federation))" data-affiliation=" (Obedinennyj Inst. Yadernykh Issledovanij, Dubna (Russian Federation))" >Krasavin, E.A.

1997-01-01

The induction of the his - -> his + mutants in vegetative and spores of Bacillus subtilis wild type cells irradiated with γ-rays and helium ions (LET = 20-80 keV/μm) has been investigated. It was shown that the dose dependence of the mutation induction in vegetative cells is described by a linear-quadratic function of dose in case of both γ-rays and helium ions. RBE (LET) dependencies on the lethal and mutagenic effect of radiation have a local maximum. The maximum of RBE (LET) dependence on the mutagenic assay is shifted at the low region of LET in comparison with the lethal effect of irradiation. (author)

Teaching Reconsidered: Exploring the Teaching Experiences of Student Affairs Professionals in the College Classroom

Directory of Open Access Journals (Sweden)

Ramona Meraz Lewis

2016-11-01

Full Text Available Aim/Purpose\tThe purpose of this study was to explore the experiences of student affairs professionals who teach in a variety of college classroom settings. Background\tIncreasingly, student affairs professionals are serving in teaching roles inside the college classroom; yet, there are few empirical studies that explore that teaching role or the impacts of that teaching experience. Because there are so few studies, we know little of the impacts of these experiences on the individual, the institution, or students. Methodology\tThis qualitative study explores the experiences of student affairs professionals who also teach in a variety of campus and classroom settings. The 12 participants from 11 different institutions ranged in years of service in the profession from six to 40 years. They taught an array of undergraduate and graduate courses including first-year experience and career courses, general education courses, and courses in higher education graduate programs. Participants share insights on how their training as student affairs professionals impacts them in their roles as college teachers. Findings\tThe findings are categorized into two broad themes: the impacts of practice on teaching and the impacts of teaching on practice. Additionally, participants share how their teaching experiences enhanced their awareness of the academic culture of the academy, enriched their understanding of students, and improved collaborations across their campuses. Future Research\tOur research addresses the gap in the literature by providing a number of considerations on how formal teaching and student affairs practice have a recursive relationship. Future research might explore how teaching at the undergraduate level may differ from teaching at the graduate level. Future research, should explore in what, if any, ways the number of years teaching influences how professionals approach teaching. Future research on teaching might also explore the experiences of

A career exploration assignment for first-year pharmacy students.

Science.gov (United States)

Sholy, Lydia; Zeenny, Rony

2013-11-12

To develop, implement, and assess student-learning outcomes from an assignment designed to expose first-year pharmacy students (P1) to a wide range of pharmacy career pathways. Students enrolled in a required Pharmacy Practice and Ethics course at the Lebanese American University chose 1 pharmacist career to investigate from a suggested list of 28 career pathways. Students completed a literature review on the selected career, interviewed a pharmacist practicing that career path in Lebanon, wrote a paper, and prepared and delivered a summary presentation to their classmates about the career pathway. Students peer evaluated their classmates after each presentation. More than 85% of the students scored ≥70% on the assignment based on their achievement of student learning outcomes. Responses on an anonymous questionnaire showed that more than 94.6% of students were satisfied with the extent to which the course allowed them to meet the established learning outcomes. A career exploration assignment provided pharmacy students with an opportunity to widen their knowledge and understanding of the different career pathways that are available for them.

Consumer Products Advertised to Save Energy--Let the Buyer Beware.

Science.gov (United States)

1981-07-24

AD-AL06 653 GENERAL ACCOUNTING OFFICE WASHINGTON DC HUMAN RESOUR--ETC F/G 5/3 CONSUMER PRODUCTS ADVERTISED TO SAVE ENERGY--LET THE BUYER BEWA-ETC...COMPTROLLER GENERAL’S CONSUMER PRODUCTS ADVERTISED REPORT TO THE CONGRESS TO SAVE ENERGY- - LET THE BUYER BEWARE D IG E ST In efforts to reduce energy costs...and comparable, GAO believes that the best ad- vice for consumers is "let the buyer beware." (See p. 42.) F’TC ’S COMMENTS FTC said that GAO

Let's Talk! ESL Students' Needs and Writing Centre Philosophy

Science.gov (United States)

Moussu, Lucie

2013-01-01

When university/college faculty members believe that ESL students' writing skills are not equivalent to those of native speakers, they frequently send these ESL students to their institution's writing centres (WCs). However, this often results in frustration for WC staff, the students, and faculty members. This article first describes ESL…

Induction and disappearance of G2 chromatid breaks in lymphocytes after low doses of low LET γ - rays and high LET fast neutrons

International Nuclear Information System (INIS)

Vral, Anne; Thierens, Hubert; Baeyens, Ans; De Ridder, Leo

2001-01-01

In view of the potential importance of the G2 assay for detecting chromosomal radiosensitivity and possible predisposition to cancer the need to elucidate the mechanism underlying the formation of chromatid breaks, observed with the G2 assay after low dose irradiation, has been recognised. In this study we irradiated blood samples of 4 healthy donors with low LET γ-rays and high LET neutrons, which initially produce the same number of dsb but of a different quality. By means of the G2 assay, we determined the number of chromatid breaks induced by γ-rays and neutrons and compared the kinetics of chromatid break rejoining for radiations of different quality. In a first set of experiments a dose-response curve for the formation of chromatid breaks was carried out for γ-rays and neutrons with doses ranging between 0.1 and 0.5 Gy. In a second set of experiments the kinetics of chromatid break formation and disappearance was investigated after a dose of 0.5 Gy using post-irradiation times ranging between 0.5 h and 3.5 h. For the highest dose of 0.5 Gy the number of isochromatid breaks were also scored. No significant differences in the number of chromatid breaks were observed between low LET γ-rays and high LET neutrons for the 4 donors at any of the doses given. The dose response curves for the formation of chromatid breaks are linear for both radiation qualities and RBE values equal to one were obtained. Scoring of isochromatid breaks at the highest dose of 0.5 Gy revealed that high LET neutrons are however more effective at inducing isochromatid breaks (RBE of 6.2). The rejoining experiments further showed that the kinetics of disappearance of chromatid breaks following irradiation with low LET γ-rays or high-LET neutrons are not significantly different. T 1/2 0.92 h for γ-rays and t 1/2 = 0.84 h for neutrons were obtained. In conclusion, our results show that at low doses of radiation the induction as well as the disappearance of G2 chromatid breaks is LET

[Career consciousness among Japanese female students: relationships between vocational motivation and career exploration].

Science.gov (United States)

Adachi, Tomoko

2008-04-01

This questionnaire study investigated career consciousness among 348 Japanese female freshman and sophomore college students. Variables included career consciousness (belief in the idea of a best-fit vocation, passivity, and giving priority to personal interests), vocational motives (self-improvement, interpersonal, status), as well as career decision-making self-efficacy (self-appraisal, gathering occupational information) and career exploration (self and environmental exploration). The results of causal analyses showed that the belief in the idea of a best-fit vocation and passivity had effects on all three vocational motives, but giving priority to personal interests had an effect only on motivation for self-improvement. Analysis of covariance (ANCOVA) models were constructed with career exploration as dependent variables, career consciousness as fixed factors, and career decision-making self-efficacy as covariates. The results of the analyses showed that students who had high career decision-making self-efficacy engaged in both self exploration and environmental exploration activities with a higher frequency. Students with a greater passive tendency toward their career engaged in both self and environmental exploration with a lower frequency. Belief in the idea of a best-fit vocation was associated only with differences in frequency of self exploration. Giving priority to personal interests did not produce differences in career exploration activities.

A simple theory of LET spectra of heavy ion beams

International Nuclear Information System (INIS)

Wilson, J.W.; Townsend, L.W.; Schimmerling, W.; Norbury, J.W.; Wong, M.; Badavi, F.

1985-01-01

The transition of high energy ion beams through extended matter is of considerable interest to the space program as well as radiobiology and medical therapy. The transition is defined in terms of various atomic/molecular and nuclear cross sections in a Boltzmann-like equation. One dimensional solutions are derived herein from which LET spectra are derived for secondary fragments. Such LET spectra are fundamental to the evaluation of beam quality, biological effects, and radiation shield effectiveness. Sensitivity of LET spectral distributions to uncertainty in physical parameters such as the isotopic fragmentation parameters, fragment mass, and absorption cross section is established for a number of ion beams. The main limitation in LET studies is the paucity of both elemental and isotopic fragmentation data. The elemental fragmentation data is more readily available because of its simple experimental procedures. It has been suggested by some that natural abundance ratios should be used with the elemental cross sections but this leads to an order-of-magnitude error in LET spectra in many cases. Very few examples of isotopic fragmentation measurements are available. Although major advances in nuclear fragmentation theory have been made, we must await more extensive isotopic fragmentation experiments for final validation

Enabling narrative pedagogy: inviting, waiting, and letting be.

Science.gov (United States)

Ironside, Pamela M

2014-01-01

This article describes how teachers enable Narrative Pedagogy in their courses by explicating the Concernful Practice Inviting: Waiting and Letting Be. Narrative Pedagogy, a research-based, phenomenological approach to teaching and learning, extends conventional pedagogies and offers nursing faculty an alternative way of transforming their schools and courses. Using hermeneutic phenomenology, interview data collected over a 10-year period were analyzed by coding practical examples of teachers' efforts to enact Narrative Pedagogy. When Narrative Pedagogy is enacted, teachers and students focus on thinking and learning together about nursing phenomena and seek new understandings about how they may provide care in the myriad situations they encounter. Although the Concernful Practices co-occur, explicating inviting experiences can assist new teachers, and those seeking to extend their pedagogical literacy, by providing new understandings of how Narrative Pedagogy can be enacted.

Let7a involves in neural stem cell differentiation relating with TLX level

Energy Technology Data Exchange (ETDEWEB)

Song, Juhyun [Department of Anatomy, Yonsei University College of Medicine, Seoul (Korea, Republic of); Cho, Kyoung Joo; Oh, Yumi [Department of Anatomy, Yonsei University College of Medicine, Seoul (Korea, Republic of); BK21 Plus Project for Medical Sciences, and Brain Research Institute, Yonsei University College of Medicine, Seoul (Korea, Republic of); Lee, Jong Eun, E-mail: jelee@yuhs.ac [Department of Anatomy, Yonsei University College of Medicine, Seoul (Korea, Republic of); BK21 Plus Project for Medical Sciences, and Brain Research Institute, Yonsei University College of Medicine, Seoul (Korea, Republic of)

2015-07-10

Neural stem cells (NSCs) have the potential for differentiation into neurons known as a groundbreaking therapeutic solution for central nervous system (CNS) diseases. To resolve the therapeutic efficiency of NSCs, recent researchers have focused on the study on microRNA's role in CNS. Some micro RNAs have been reported significant functions in NSC self-renewal and differentiation through the post-transcriptional regulation of neurogenesis genes. MicroRNA-Let7a (Let7a) has known as the regulator of diverse cellular mechanisms including cell differentiation and proliferation. In present study, we investigated whether Let7a regulates NSC differentiation by targeting the nuclear receptor TLX, which is an essential regulator of NSC self-renewal, proliferation and differentiation. We performed the following experiments: western blot analysis, TaqMan assay, RT-PCR, and immunocytochemistry to confirm the alteration of NSCs. Our data showed that let7a play important roles in controlling NSC fate determination. Thus, manipulating Let-7A and TLX could be a novel strategy to enhance the efficiency of NSC's neuronal differentiation for CNS disorders. - Highlights: • Let7a influences on NSC differentiation and proliferation. • Let7a involves in mainly NSC differentiation rather than proliferation. • Let7a positively regulates the TLX expression.

Let7a involves in neural stem cell differentiation relating with TLX level

International Nuclear Information System (INIS)

Song, Juhyun; Cho, Kyoung Joo; Oh, Yumi; Lee, Jong Eun

2015-01-01

Neural stem cells (NSCs) have the potential for differentiation into neurons known as a groundbreaking therapeutic solution for central nervous system (CNS) diseases. To resolve the therapeutic efficiency of NSCs, recent researchers have focused on the study on microRNA's role in CNS. Some micro RNAs have been reported significant functions in NSC self-renewal and differentiation through the post-transcriptional regulation of neurogenesis genes. MicroRNA-Let7a (Let7a) has known as the regulator of diverse cellular mechanisms including cell differentiation and proliferation. In present study, we investigated whether Let7a regulates NSC differentiation by targeting the nuclear receptor TLX, which is an essential regulator of NSC self-renewal, proliferation and differentiation. We performed the following experiments: western blot analysis, TaqMan assay, RT-PCR, and immunocytochemistry to confirm the alteration of NSCs. Our data showed that let7a play important roles in controlling NSC fate determination. Thus, manipulating Let-7A and TLX could be a novel strategy to enhance the efficiency of NSC's neuronal differentiation for CNS disorders. - Highlights: • Let7a influences on NSC differentiation and proliferation. • Let7a involves in mainly NSC differentiation rather than proliferation. • Let7a positively regulates the TLX expression

Diffusion-kinetic theories for LET effects on the radiolysis of water

International Nuclear Information System (INIS)

Pimblott, S.M.; LaVerne, J.A.

1994-01-01

Diffusion-kinetic methods are used to investigate the effects of incident particle linear energy transfer (LET) on the radiolysis of water and aqueous solutions. Chemically realistic deterministic diffusion-kinetic calculations examining the scavenging capacity dependences of the scavenged yield of e aq - and of OH demonstrate that the scavenged yields are related to the underlying time-dependent kinetics in the absence of the scavenger by a simple Laplace transform relationship. This relationship is also shown to link the effect of an e eq - scavenger on the formation of H 2 with the time dependence of H 2 production in the absence of the scavenger. The simple Laplace relationship does not work well when applied to H 2 O 2 formation in high-LET particle tracks even though such a relationship is valid with low-LET particles. It is found that while the secondary reaction of H 2 O 2 with e aq - can be neglected in low-LET particle radiolysis, it is of considerable significance in the tracks produced by high-LET particles. The increased importance of this reaction with increasing LET is the major reason for the failure of the Laplace relationship for H 2 O 2 . 55 refs., 9 figs., 2 tabs

Irradiation of single cells with individual high-LET particles

International Nuclear Information System (INIS)

Nelson, J.M.; Braby, L.A.

1993-01-01

The dose-limiting normal tissue of concern when irradiating head and neck lesions is often the vascular endothelium within the treatment field. Consequently, the response of capillary endothelial cells exposed to moderate doses of high LET particles is essential for establishing exposure limits for neutron-capture therapy. In an effort to characterize the high-LET radiation biology of cultured endothelial cells, the authors are attempting to measure cellular response to single particles. The single-particle irradiation apparatus, described below, allows them to expose individual cells to known numbers of high-LET particles and follow these cells for extended periods, in order to assess the impact of individual particles on cell growth kinetics. Preliminary cell irradiation experiments have revealed complications related to the smooth and efficient operation of the equipment; these are being resolved. Therefore, the following paragraphs deal primarily with the manner by which high LET particles deposit energy, the requirements for single-cell irradiation, construction and assembly of such apparatus, and testing of experimental procedures, rather than with the radiation biology of endothelial cells

Exploring student teachers' perceptions of the influence of ...

African Journals Online (AJOL)

Rapid global technological developments have affected all facets of life, including the teaching and learning of mathematics. This qualitative study was designed to identify the ways in which technology was used and to explore the nature of this use by a group of 52 mathematics student teachers. The participants were ...

Reversal of diuretic-associated impaired glucose tolerance and new-onset diabetes: results of the STAR-LET study.

Science.gov (United States)

Bakris, George; Molitch, Mark; Zhou, Qian; Sarafidis, Pantelis; Champion, Annette; Bacher, Peter; Sowers, James R

2008-01-01

Reversal of new-onset diabetes secondary to thiazide diuretic use remains questionable. STAR-LET was a 6-month extension of the Study of Trandolapril/Verapamil SR and Insulin Resistance (STAR), which assessed the effects of a fixed-dose renin-angiotensin system inhibitor (RASI)/hydrochlorothiazide (HCTZ) combination on changes in 2-hour oral glucose tolerance test (OGTT) results. STAR-LET explored whether the glycemic impact of HCTZ could be reversed by conversion to a RASI/verapamil combination. The primary outcome was change in 2-hour OGTT results. Fifty-one percent of the STAR patients were enrolled in STAR-LET. The 2-hour OGTT value (mmol/L) was unchanged from STAR baseline in the RASI/verapamil group (7.7+/-2.4 vs 8.1+/-3.3; P=.18) and improved in those who were switched from RASI/HCTZ to RASI/verapamil (8.5+/-3.0 vs 7.2+/-2.3; P<.001). This exploratory study suggests that the impairment in glycemic control seen with use of a thiazide diuretic combined with a RASI can be reversed by switching to a regimen that does not include a diuretic.

High LET radiation and mechanism of DNA damage repair

International Nuclear Information System (INIS)

Furusawa, Yoshiya

2004-01-01

Clarifying the mechanism of repair from radiation damage gives most important information on radiation effects on cells. Approximately 10% of biological experiments groups in Heavy Ion Medical Accelerator in Chiba (HIMAC) cooperative research group has performed the subject. They gave a lot of new findings on the mechanism, and solved some open questions. The reason to show the peak of relative biological effectiveness RBE at around 100-200 keV/μm causes miss-repair of DNA damage. Sub-lethal damage generated by high linear energy transfer (LET) radiation can be repaired fully. Potentially lethal damages by high-LET radiation also repaired, but the efficiency decreased with the LET, and so on. (author)

Unlocking Resources: Self-Guided Student Explorations of Science Museum and Aquarium Exhibits

Science.gov (United States)

Kirkby, K. C.; Phipps, M.; Hamilton, P.

2010-12-01

Remarkably few undergraduate programs take full advantage of the rich resources provided by science museums, aquariums and other informal science education institutions. This is not surprising considering the logistical hurdles of class trips, but an even more fundamental barrier is that these institutions’ exhibit text seldom explicitly convey their information at a level suitable for undergraduate curriculum. Traditionally, this left the burden of interpretation on individual instructors, who rarely have the time to undertake it. To overcome these hurdles, the University of Minnesota has partnered with the Science Museum of Minnesota and Underwater Adventures Aquarium to test the efficacy of self-guided student explorations in revealing the rich data encoded in museum and aquarium exhibits. An initial module at the Science Museum of Minnesota focused on interpreting animal designs, specifically exploring how differences in dinosaur skeletal features reflected variations in the animals’ lifestyles. Students learn to interpret diet and lifestyle not only from characteristics of the skull and teeth, but also from variations in vertebrae and rib design or the relative proportion of limb elements. A follow-up module, based on exhibits at Underwater Adventures Aquarium focuses on interpreting energy flow through ecosystems from the behavior of living organisms. Students explore the information on lifestyle and diet that is encoded in a sturgeon’s ceaseless glide or a muskellunge’s poised stillness. These modules proved to be immensely popular with students. In classes with up to 500 students, half to two-thirds of the students volunteered to complete the modules, despite the additional expense and distances of up to 13 miles between the University and partner institutions. More importantly, quantitative assessment with pre-instruction and post-instruction surveys demonstrate that these ungraded, self-guided explorations match or exceed the efficacy of

Exploring multiliteracies, student voice, and scientific practices in two elementary classrooms

Science.gov (United States)

Allison, Elizabeth Rowland

This study explored the voices of children in a changing world with evolving needs and new opportunities. The workplaces of rapidly moving capitalist societies value creativity, collaboration, and critical thinking skills which are of growing importance and manifesting themselves in modern K-12 science classroom cultures (Gee, 2000; New London Group, 2000). This study explored issues of multiliteracies and student voice set within the context of teaching and learning in 4th and 5th grade science classrooms. The purpose of the study was to ascertain what and how multiliteracies and scientific practices (NGSS Lead States, 2013c) are implemented, explore how multiliteracies influence students' voices, and investigate teacher and student perceptions of multiliteracies, student voice, and scientific practices. Grounded in a constructivist framework, a multiple case study was employed in two elementary classrooms. Through observations, student focus groups and interviews, and teacher interviews, a detailed narrative was created to describe a range of multiliteracies, student voice, and scientific practices that occurred with the science classroom context. Using grounded theory analysis, data were coded and analyzed to reveal emergent themes. Data analysis revealed that these two classrooms were enriched with multiliteracies that serve metaphorically as breeding grounds for student voice. In the modern classroom, defined as a space where information is instantly accessible through the Internet, multiliteracies can be developed through inquiry-based, collaborative, and technology-rich experiences. Scientific literacy, cultivated through student communication and collaboration, is arguably a multiliteracy that has not been considered in the literature, and should be, as an integral component of overall individual literacy in the 21st century. Findings revealed four themes. Three themes suggest that teachers address several modes of multiliteracies in science, but identify

Molecular analysis of two genes between let-653 and let-56 in the unc-22(IV) region of Caenorhabditis elegans.

Science.gov (United States)

Marra, M A; Prasad, S S; Baillie, D L

1993-01-01

A previous study of genomic organization described the identification of nine potential coding regions in 150 kb of genomic DNA from the unc-22(IV) region of Caenorhabditis elegans. In this study, we focus on the genomic organization of a small interval of 0.1 map unit bordered on the right by unc-22 and on the left by the left-hand breakpoints of the deficiencies sDf9, sDf19 and sDf65. This small interval at present contains a single mutagenically defined locus, the essential gene let-56. The cosmid C11F2 has previously been used to rescue let-56. Therefore, at least some of C11F2 must reside in the interval. In this paper, we report the characterization of two coding elements that reside on C11F2. Analysis of nucleotide sequence data obtained from cDNAs and cosmid subclones revealed that one of the coding elements closely resembles aromatic amino acid decarboxylases from several species. The other of these coding elements was found to closely resemble a human growth factor activatable Na+/H+ antiporter. Paris of oligonucleotide primers, predicted from both coding elements, have been used in PCR experiments to position these coding elements between the left breakpoint of sDf19 and the left breakpoint of sDf65, between the essential genes let-653 and let-56.

Experimental and calculated LET distributions in the Cosmos-2044 biosatellite orbit

International Nuclear Information System (INIS)

Dudkin, V.E.; Karpov, O.N.; Potapov, Yu.V.; Benton, E.V.; Frank, A.L.; Watts, J.W. Jr.

1992-01-01

During the flight of the Cosmos-2044 biosatellite, joint U.S.S.R.-U.S.A. investigations of different characteristics of cosmic radiation (CR) in the near-Earth environment were carried out. The U.S. dielectric track detectors CR-39 and Soviet BYa- and BR-type nuclear photo-emulsions were used as detectors. The present work shows some results of experimental measurements of linear energy transfer (LET) spectra of CR particles obtained with the use of these detectors, which were placed both inside and outside the satellite. The LET spectra measurement with plastic detectors is composed of two parts: the measurement of galactic cosmic rays (GCR) particles, and of short-range particles. The contributions of these components to the total LET distribution at various thicknesses of the shielding were analyzed and the results of these studies are presented. Calculated LET spectra in the Cosmos-2044 orbit were compared with experimental data. On the basis of experimental and calculated values of the LET spectra, absorbed and equivalent CR doses were calculated. In the shielding range of 1-1.5 g cm -2 , outside the spacecraft, the photo-emulsions yielded 10.3 mrad d -1 and 27.5 mrem d -1 (LET ≥ 2 MeV cm -1 ) while the CR-39 yielded averages of 1.43 mrad d -1 and 13.4 mrem d -1 (LET ≥ 40 MeV cm -1 ). Inside the spacecraft (≥10 g cm -2 ) the photo-emulsions yielded 8.9 mrad d -1 and 14.5 mrem d -1 . (author)

Let's Start the Music.

Science.gov (United States)

Ivankovic, Patricia; Gilpatrick, Ingrid

1994-01-01

A preschool/kindergarten program that serves 18 students with deafness/hearing impairments and 11 hearing children uses music activities to develop speech, audition, language, and movement and to further explore current classroom themes. A deaf teacher models body movements, signs, rhythm, and facial expressions while a hearing teacher models…

Exploring the Climate for Overweight and Obese Students in a Student Health Setting

Science.gov (United States)

Pedersen, Peggy J.; Ketcham, Patricia L.

2009-01-01

Attitudes and beliefs of health care providers, in conjunction with a nonthreatening physical environment, are important components in establishing a constructive and supportive climate for care of overweight and obese students. Objective: The authors explored providers' attitudes about obesity and assessed the physical environment in a student…

Simulated Job Samples: A Student-Centered Approach to Vocational Exploration and Evaluation.

Science.gov (United States)

Richter-Stein, Caryn; Stodden, Robert A.

1981-01-01

Incorporating simulated job samples into the junior high school curriculum can provide vocational exploration opportunities as well as assessment data on special needs students. Students can participate as active learners and decision makers. (CL)

`Let your data tell a story:' climate change experts and students navigating disciplinary argumentation in the classroom

Science.gov (United States)

Walsh, Elizabeth Mary; McGowan, Veronica Cassone

2017-01-01

Science education trends promote student engagement in authentic knowledge in practice to tackle personally consequential problems. This study explored how partnering scientists and students on a social media platform supported students' development of disciplinary practice knowledge through practice-based learning with experts during two pilot enactments of a project-based curriculum focusing on the ecological impacts of climate change. Through the online platform, scientists provided feedback on students' infographics, visual argumentation artifacts that use data to communicate about climate change science. We conceptualize the infographics and professional data sets as boundary objects that supported authentic argumentation practices across classroom and professional contexts, but found that student generated data was not robust enough to cross these boundaries. Analysis of the structure and content of the scientists' feedback revealed that when critiquing argumentation, scientists initiated engagement in multiple scientific practices, supporting a holistic rather than discrete model of practice-based learning. While traditional classroom inquiry has emphasized student experimentation, we found that engagement with existing professional data sets provided students with a platform for developing expertise in systemic scientific practices during argument construction. We further found that many students increased the complexity and improved the visual presentation of their arguments after feedback.

Exploring Plagiarism into Perspectives of Indonesian Academics and Students

Directory of Open Access Journals (Sweden)

Rina Agustina

2017-08-01

Full Text Available Plagiarism has been done by students from around the globes. There has been a heated discussion of finding reasons why plagiarism occurred in academic world and Eastern students in particular. This research wants to explore how actually students perceive plagiarism in their academic writing as well as how lecturers coped with plagiarism in the students’ assignments. The research participants were taken from 2 different majors, 32 English Education students and 10 Psychology students as well as 5 lecturers from English Education Department and 3 lecturers from Psychology Faculty in one of private universities in Central Java Province, Indonesia. Questionnaires were distributed to those respondents and also interviews were conducted to several lecturers and students. The results of questionnaire and interview showed that both students and lecturers knew and understand the essence of plagiarism, however, students admitted that they still plagiarised in their assignment. Lecturers, on the other hand, revealed that they could figure out when students plagiarised others’ works. However, it was limited to crossing over assignments between students. In other words, detecting plagiarism was done manually and restricted to students’ written works only. In conclusion, despite comprehending the meaning of plagiarism, student still plagiarised since there was not any real action from lecturers to encounter it.

Let s make progress together!

Science.gov (United States)

Adriana, Mazare; Liliana, Gheorghian

2015-04-01

Let's make progress together! The "Theodor Balan" Secondary School in the urban area of Suceava County in northeastern Romania is involved in several different projects. In order to extend previous successful projects with the students, parents, teachers, businesses and local government representatives in science symposiums for civic projects within the concept of sustainable development, the school is continuing to develop various successful programs. "The battle" continues both in nature and in the classrooms, in order to preserve the environment and to discover new resources. To raise awareness about the importance of existing resources even at the level of individuals there is a constant concern for keeping up to date on what already exists and is well known, but at the same time to remove "barriers" and discover new horizons and resources. Scientific activities held in our school are an effective way to educate students and the community to which they belong. In our community, we discovered sources of drinking water polluted by nitrites from fertilizers used in agriculture. In order to inform and educate people in the area, our teachers have organized several educational activities. Its purpose was: -Knowledge of the importance of water for the environment and human health. -Reducing water pollution. Students have informed their families' about sustainable development acquired at school. In this way, the school manages to educate and change people's ideas. The ways and methods of adults' learning were practiced within a Grundtvig training course "It's never too late learning to learn" in February 2014, in Florence, Italy. The GIFT 2014 was a great occasion for the teachers and students, the county's educational department and the participants at the National Colloquia of Physics to discover new materials provided at the Conference and the latest news and topics in the world of science. The theme trips at the physics laboratories of "Alexandru Ioan Cuza

Exploring student teachers' perceptions of the influence of ...

African Journals Online (AJOL)

user

2015-11-11

Nov 11, 2015 ... This qualitative study was designed to identify the ways in which technology was used and to explore the nature of ... The use of technology requires research and careful planning in order for it to .... Methodology .... teaching by the student teachers, the social inter- ..... and quantitative approaches (7th ed).

Unpacking the Value of Writing: Exploring College Students' Perceptions of Writing

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Zumbrunn, Sharon; Carter, Yvette M.; Conklin, Sarah

2014-01-01

This study explored college students' beliefs about the value of writing, their past experiences with writing, and the relationship between students' prior experiences with writing and writing value beliefs. One hundred fourteen undergraduates from a public Southeastern university participated in the study. Using expectancy-value theory as a…

Exploring the Differences of Undergraduate Students' Perceptual Learning Styles in International Business Study

Science.gov (United States)

Ding, Ning; Lin, Wei

2013-01-01

More than 45,000 international students are now studying for bachelor programs in The Netherlands. The number of Asian students increased dramatically in the past decade. The current research aims at examining the differences between Western European and Asian students' perceptual learning styles, and exploring the relationships between students'…

High-LET dose-response characteristics by track structure theory of heavy charged particles

International Nuclear Information System (INIS)

Hansen, J.W.; Olsen, K.J.

1981-09-01

The track structure theory developed by Katz and co-workers ascribes the effect of high-LET radiation to the highly inhomogeneous dose distribution due to low energy Δ-rays ejected from the particle track. The theory predicts the effectiveness of high-LET radiation by using the ion parameters zsub(eff') effective charge of the ion, and β = v/c, the relative ion velocity, together with the characteristic dose D 37 derived from low-LET dose-response characteristic of the detector and the approximate size asub(0) of the sensitive element of the detector. 60 Co gamma-irradiation is used as a reference low-LET radiation, while high-LET radiation ranging from 16 MeV protons to 4 MeV/amu 16 0-ions covering an initial LET range of 30-5500 MeVcm 2 /g is obtained from a tandem Van de Graaff accelerator. A thin film (5mg/cm 2 ) radiochromic dye cyanide plastic dosemeter was used as detector with the characteristic dose of 16.8 Mrad and a sensitive element size of 10 -7 cm. Theoretical and experimental effectiveness, RBE, agreed within 10 to 25% depending on LET. (author)

High-LET charged particle radiotherapy

International Nuclear Information System (INIS)

Castro, J.R.; California Univ., San Francisco, CA

1991-07-01

The Department of Radiation Oncology at UCSF Medical Center and the Radiation Oncology Department at UC Lawrence Berkeley Laboratory have been evaluating the use of high LET charged particle radiotherapy in a Phase 1--2 research trial ongoing since 1979. In this clinical trail, 239 patients have received at least 10 Gy (physical) minimum tumor dose with neon ions, meaning that at least one-half of their total treatment was given with high-LET charged particle therapy. Ninety-one patients received all of their therapy with neon ions. Of the 239 patients irradiated, target sites included lesions in the skin, subcutaneous tissues, head and neck such as paranasal sinuses, nasopharynx and salivary glands (major and minor), skull base and juxtaspinal area, GI tract including esophagus, pancreas and biliary tract, prostate, lung, soft tissue and bone. Analysis of these patients has been carried out with a minimum followup period of 2 years

Exploring Student Perceptions of Audiovisual Feedback via Screencasting in Online Courses

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Mathieson, Kathleen

2012-01-01

Using Moore's (1993) theory of transactional distance as a framework, this action research study explored students' perceptions of audiovisual feedback provided via screencasting as a supplement to text-only feedback. A crossover design was employed to ensure that all students experienced both text-only and text-plus-audiovisual feedback and to…

Exploring Students' Conceptions of Science Learning via Drawing: A Cross-Sectional Analysis

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Hsieh, Wen-Min; Tsai, Chin-Chung

2017-01-01

This cross-sectional study explored students' conceptions of science learning via drawing analysis. A total of 906 Taiwanese students in 4th, 6th, 8th, 10th, and 12th grade were asked to use drawing to illustrate how they conceptualise science learning. Students' drawings were analysed using a coding checklist to determine the presence or absence…

EXPLORING THE TERTIARY EFL STUDENTS' ACADEMIC WRITING COMPETENCIES

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Aunurrahman Aunurrahman

2017-05-01

Full Text Available For tertiary English as a Foreign Language (EFL students, academic writing is not an easy task. It requires knowledge of the academic writing genres with their particular linguistic features. Moreover, academic writing demands good critical thinking. This research aims to explore the students' academic writing competencies that also focus on critical thinking. The research involved thirty-six first-year tertiary EFL students from a regular class of a private university in Pontianak, West Kalimantan, Indonesia. The source for data collection was the students’ texts. Three texts were selected and the students were categorized into low, medium, and high levels of writing achievement. The text analysis utilized functional grammar rooted in systemic functional linguistics (Emilia, 2014. The analysis shows that the students, regardless of their levels of writing achievement, have little control over the schematic structure and linguistic features of an argumentative writing. The text analysis also shows that the students’ texts have some limitations as regards their critical thinking capacity. Still, a few examples of academic language were detected in the texts. The findings suggest that the lecturer should incorporate explicit teaching and cooperative learning activities to alleviate the students' difficulties and develop their academic writing and critical thinking capacity.

Addiction Studies: Exploring Students' Attitudes toward Research in a Graduate Program

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James, Raven; Simons, Lori

2011-01-01

An exploratory study was conducted to compare addiction studies and community counseling students' attitudes toward research. A survey of 66 addiction studies and 17 community counseling students in graduate programs was used to explore interest and self-efficacy in research and the research training environment. A pre/post test design was used to…

Exploring Gender through Education Abroad Programs: A Graduate Student Case Study

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Squire, Dian D.; Williams, Terry E.; Cartwright, Matthew; Jourian, T. J.; Monter, Marie; Weatherford, Amy

2015-01-01

This case study explores how graduate students who attended a short-term education abroad program understood gender as a result of participation in the trip. Findings reveal that students' understandings of gender are influenced by in and out of class contexts. Implications for faculty and education abroad practitioners are shared to deepen and…

The let-7/Lin28 axis regulates activation of hepatic stellate cells in alcoholic liver injury.

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McDaniel, Kelly; Huang, Li; Sato, Keisaku; Wu, Nan; Annable, Tami; Zhou, Tianhao; Ramos-Lorenzo, Sugeily; Wan, Ying; Huang, Qiaobing; Francis, Heather; Glaser, Shannon; Tsukamoto, Hidekazu; Alpini, Gianfranco; Meng, Fanyin

2017-07-07

The let-7/Lin28 axis is associated with the regulation of key cellular regulatory genes known as microRNAs in various human disorders and cancer development. This study evaluated the role of the let-7/Lin28 axis in regulating a mesenchymal phenotype of hepatic stellate cells in alcoholic liver injury. We identified that ethanol feeding significantly down-regulated several members of the let-7 family in mouse liver, including let-7a and let-7b. Similarly, the treatment of human hepatic stellate cells (HSCs) with lipopolysaccharide (LPS) and transforming growth factor-β (TGF-β) significantly decreased the expressions of let-7a and let-7b. Conversely, overexpression of let-7a and let-7b suppressed the myofibroblastic activation of cultured human HSCs induced by LPS and TGF-β, as evidenced by repressed ACTA2 (α-actin 2), COL1A1 (collagen 1A1), TIMP1 (TIMP metallopeptidase inhibitor 1), and FN1 (fibronectin 1); this supports the notion that HSC activation is controlled by let-7. A combination of bioinformatics, dual-luciferase reporter assay, and Western blot analysis revealed that Lin28B and high-mobility group AT-hook (HMGA2) were the direct targets of let-7a and let-7b. Furthermore, Lin28B deficiency increased the expression of let-7a/let-7b as well as reduced HSC activation and liver fibrosis in mice with alcoholic liver injury. This feedback regulation of let-7 by Lin28B is verified in hepatic stellate cells isolated by laser capture microdissection from the model. The identification of the let-7/Lin28 axis as an important regulator of HSC activation as well as its upstream modulators and down-stream targets will provide insights into the involvement of altered microRNA expression in contributing to the pathogenesis of alcoholic liver fibrosis and novel therapeutic approaches for human alcoholic liver diseases. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Mutagenic action of radiation with different LET on Bacillus subtilis cells

International Nuclear Information System (INIS)

Borejko, A.V.; Krasavin, E.A.

1996-01-01

The induction of the his - →his + mutants in vegetative and spores of Bacillus subtilis wild type cells irradiated with γ-rays and helium ions (LET=20-80 keV/μm has been investigated. It was shown that the dose dependence of the mutation induction in vegetative cells is described by a linear-quadratic function of dose in case of both γ-rays and helium ions. RBE (LET) dependence on the mutagenic assay is shifted at the low region of LET. (author). 11 refs., 4 figs

Exploring Erasmus student mobility in Ukraine: A case study

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Yevhen Baranchenko

2016-04-01

Full Text Available In the context of increasing interest in the internationalisation of education, the Erasmus programme of student mobility led by the European Commission is perceived as a highly desirable by many stakeholders.  Despite the high demand emanating from Ukrainian students for Erasmus programme participation, the inward student mobility of EU nationals to Ukraine remains exceptionally low at the undergraduate level. The main aim of the current study is to explore the inward Erasmus student mobility mechanism in Ukraine through application of the single case study approach.  The data were collected through participant observation, two rounds of interviews and the analysis of the participant diary.  The research outcomes shed light on how the inward Erasmus student mobility programme in Ukraine can be arranged more effectively. We identified four broad areas by means of thematic analysis, which includes transparency of the process; communication; living conditions; learning process and facilities.

Fast Neutrons - LET Distributions and the Response of Mammalian Cells

Energy Technology Data Exchange (ETDEWEB)

Bewley, D. K. [Medical Research Council Cyclotron Unit, Hammersmith Hospital, London (United Kingdom)

1968-03-15

Distributions of stopping power (LET) are given for four beams of fast neutrons, namely, neutrons of 14.6 MeV, neutrons produced by bombarding a thick beryllium target with 15 MeV deuterons, neutrons of 3 MeV, and fast neutrons produced by bombardment of a {sup 235}U converter plate with thermal neutrons. The track average LET is correlated with mean neutron energy, but the dose average is approximately constant. However, neither of these types of average is expected to have much relevance to radiobiology. Further, specification of a ''biologically effective LET'' depends on the biological test used, and is not solely a function of the radiation quality. An attempt has been made to calculate the response of T.I. kidney cells in tissue culture to these four beams of neutrons, based on their response to charged particles using the track-segment method. The calculated RBE's of the neutron beams are lower than the observed values and the calculated values of the oxygen enhancement ratio are higher. These differences seem too great to be explained by errors in dosimetry and in the calculated LET spectra. The suggestion is made that LET is not an adequate criterion of radiation quality, and that the discrepancies may be explained by more detailed consideration of the part played by delta rays and by heavy recoil tracks of short range. (author)

Exploring the Changes in Students' Understanding of the Scientific Method Using Word Associations

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Gulacar, Ozcan; Sinan, Olcay; Bowman, Charles R.; Yildirim, Yetkin

2015-01-01

A study is presented that explores how students' knowledge structures, as related to the scientific method, compare at different student ages. A word association test comprised of ten total stimulus words, among them "experiment," "science fair," and "hypothesis," is used to probe the students' knowledge structures.…

Keep it local (and final): Remnant preferences in "let alone" ellipsis.

Science.gov (United States)

Harris, Jesse A; Carlson, Katy

2016-01-01

The let alone construction (John can't run a mile, let alone a marathon) differs from standard coordination structures (with and or but) by requiring ellipsis of the second conjunct--for example, a marathon is the remnant of an elided clause [[see text] a marathon]. In support of an ellipsis account, a corpus study of British and American English finds that let alone exhibits a Locality bias, as the second conjunct preferentially contrasts with the nearest lexical item of the same syntactic type. Two self-paced reading studies show that the Locality bias is active during online processing, but must be reconciled with indicators of semantic contrast and discourse information. Further, a sentence-rating study shows that the Locality bias interacts with a Finality bias that favours placing the let alone phrase at the end of a clause, which sometimes necessitates a nonlocal contrast. Together, the results show how a general bias in ellipsis for local contrasts is affected by discourse demands, such as the need for scalar contrast imposed by let alone, thereby offering a window into how possibly divergent syntactic and discourse constraints impact sentence processing.

High-LET radiation carcinogenesis

International Nuclear Information System (INIS)

Fry, R.J.M.; Powers-Risius, P.; Alpen, E.L.; Ainsworth, E.J.

1985-01-01

The dose-response curves for the induction of tumors by high-LET radiation are complex and are insufficiently understood. There is no model or formulation to describe the dose-response relationship over a range 0 to 100 rad. Evidence suggests that at doses below 20 rad the response is linear, at least for life shortening and some tumor systems. Thus, limiting values of RBEs for the induction of cancer in various tissues can be determined, but it will require sufficient data obtained at low single doses or with small fractions. The results obtained from experiments with heavy ions indicate an initial linear response with a plateauing of the curve at a tumor incidence level that is dependent on the type of tissue. The RBE values for the heavy ions using 60 Co gamma rays as the reference radiation increase with the estimated LET from 4 for 4 H to about 27 for 56 Fe, 40 Ar. The dose-responses and RBEs for 56 Fe and 40 Ar are similar to those for fission neutrons. These findings suggest the possibility that the effectiveness for tumor induction reaches a maximum. 26 refs., 4 figs., 2 tabs

Apoptosis induced by high- and low-LET radiations

International Nuclear Information System (INIS)

Hendry, J.H.; Potten, C.S.; Merritt, A.

1995-01-01

Cell death after irradiation occurs by apoptosis in certain cell populations in tissues. The phenomenon also occurs after high linear energy transfer (LET) irradiation, and the relative biological effectiveness (RBE) is 3 to 4 (with respect to low-LET radiation and apoptosis in intestinal crypts) for neutrons with energies of 14 MeV and up to 600 MeV. It is thought that p53 plays a role in the phenomenon, as radiation-induced apoptosis is not observed in p53-null animals. (orig.)

Generalized concept of the LET-RBE relationship of radiation-induced chromosome aberration and cell death

International Nuclear Information System (INIS)

Takatsuji, Toshihiro; Yoshikawa, Isao; Sasaki, Masao S.

1999-01-01

The frequency of chromosome aberrations per traversal of a nucleus by a charged particle at the low dose limit increases proportionally to the square of the linear energy transfer (LET), peaks at about 100 keV/μm and then decreases with further increase of LET. This has long been interpreted as an excessive energy deposition over the necessary energy required to produce a biologically effective event. Here, we present an alternative interpretation. Cell traversed by a charged particle has certain probability to receive lethal damage leading to direct death. Such events may increase with an increase of LET and the number of charged particles traversing the cell. Assuming that the lethal damage is distributed according to a Poisson distribution, the probability that a cell has no such damage is expressed by e -cLx , where c is a constant, L is LET, and x is the number of charged particles traversing the cell. From these assumptions, the frequency of chromosome aberration in surviving cells can be described by Y=αSD+βS 2 D 2 with the empirical relation Y=αD+βD 2 in the low LET region, where S=e -cL , α is a value proportional to LET, β is a constant, and D is the absorbed dose. This model readily explains the empirically established relationship between LET and relative biological effectiveness (RBE). The model can also be applied to clonogenic survival. If cells can survive and they have neither unstable chromosome aberrations nor other lethal damage, the LET-RBE relationship for clonogenic survival forms a humped curve. The relationship between LET and inactivation cross-section becomes proportional to the square of LET in the low LET region when the frequency of a directly lethal events is sufficiently smaller than unity, and the inactivation cross-section saturates to the cell nucleus cross-sectional area with an increase in LET in the high LET region. (author)

General Chemistry Students' Goals for Chemistry Laboratory Coursework

Science.gov (United States)

DeKorver, Brittland K.; Towns, Marcy H.

2015-01-01

Little research exists on college students' learning goals in chemistry, let alone specifically pertaining to laboratory coursework. Because students' learning goals are linked to achievement and dependent on context, research on students' goals in the laboratory context may lead to better understanding about the efficacy of lab curricula. This…

Improvement of date palm plant lets during rooting stage by silver ion

International Nuclear Information System (INIS)

Sharaf, M.M.; Khamis, M.A.; El Bana, A.; Abd El Galeil, L.M.; Zaid, Z.E.

2012-01-01

This study aim to promote growth plant lets of date palm cv. Zaghlool by decreasing ethylene production inside the containers during rooting stage. Data obtained declared that three silver thiosulphate (STS) levels added to one half strength MS rooting medium improved significantly three rooting measurements (rooting percentage; number and length of developed root lets). However, the lightest STS level (0.25 ml/L of 4 mM STS solution) was the superior, while highest one (1.0 ml/L) was the inferior from statistical point of view. Data obtained displayed that providing MS rooting medium with silver nitrate improved 3 rooting measurements (rooting %; number of root lets and their length) for Zaghloul date palm shoot lets proliferated from somatic embryos. However, the 0.50 mg/L AgNO 3 provided MS medium was the most preferable in this concern. Plant lets were transferred to capped tubes contained 1/4 liquid MS medium through 3 weeks in the growth chamber (under aseptic condition). Ventilation was allowed gradually by punching holes in aluminum foil caps during first five days of 2 nd week. After then, the plant lets were transplanted in acclimatization green house on mixture from (peat moss + perlite + vermiculite at 1:1:1) and survival percentage was 75% after three months.

PARP-1 is a key player in controlling apoptosis induced by high LET carbon ion beam and low LET gamma radiation in HeLa cells

International Nuclear Information System (INIS)

Ghorai, Atanu; Ghosh, Utpal; Bhattacharyya, Nitai P.; Sarma, Asitikantha

2014-01-01

PARP-1 inhibitors have long been used as chemo-sensitizer or radio-sensitizer and specific PARP-1 inhibitors are also in clinical trial for the treatment of various cancers. PARP-1 is not only involved in DNA repair but also plays very complex role in induction of apoptosis in postirradiation condition. Our objective is to investigate role of PARP-1 in apoptosis triggered by high LET carbon ion beam (CIB) and low LET gamma. We have treated HeLa and PARP-1 knock down HeLa (Hsil) cells with various doses of CIB and gamma. We measured DNA damage by comet assay and various apoptotic parameters such as nuclear fragmentation, activation of caspase-3,8,9, AIF translocation etc. We observed higher DNA breaks and also higher apoptosis in HsiI cells compared with HeLa cells. Both CIB and gamma treatment results G2/M arrest but unlike gamma CIB makes S-phase delay, implicating that gamma and CIB triggers different pathway after DNA damage. Cell death by CIB or by gamma increased up on knocking down of PARP-1 but increase is higher for high LET CIB compared with low LET gamma. Furthermore, expression level of PARP-1 controls the intensity of overall apoptosis in cells in post-irradiation condition. So, combination of PARP-1 inhibition with high LET CIB could be a promising tool to combat cancer. (author)

Exploring Different Patterns of Love Attitudes among Chinese College Students.

Science.gov (United States)

Zeng, Xianglong; Pan, Yiqin; Zhou, Han; Yu, Shi; Liu, Xiangping

2016-01-01

Individual differences in love attitudes and the relationship between love attitudes and other variables in Asian culture lack in-depth exploration. This study conducted cluster analysis with data regarding love attitudes obtained from 389 college students in mainland China. The result of cluster analysis based on love-attitude scales distinguished four types of students: game players, rational lovers, emotional lovers, and absence lovers. These four groups of students showed significant differences in sexual attitudes and personality traits of deliberation and dutifulness but not self-discipline. The study's implications for future studies on love attitudes in certain cultural groups were also discussed.

An Arduino Investigation of Simple Harmonic Motion

Science.gov (United States)

Galeriu, Calin; Edwards, Scott; Esper, Geoffrey

2014-01-01

We cannot hope for a new generation of scientists and engineers if we don't let our young students take ownership of their scientific and engineering explorations, if we don't let them enjoy the hands-on cycle of design and production, and if we don't let them implant their creativity into a technologically friendly environment.…

Radiation-Induced Epigenetic Alterations after Low and High LET Irradiations

Energy Technology Data Exchange (ETDEWEB)

Aypar, Umut; Morgan, William F.; Baulch, Janet E.

2011-02-01

Epigenetics, including DNA methylation and microRNA (miRNA) expression, could be the missing link in understanding the delayed, non-targeted effects of radiation including radiationinduced genomic instability (RIGI). This study tests the hypothesis that irradiation induces epigenetic aberrations, which could eventually lead to RIGI, and that the epigenetic aberrations induced by low linear energy transfer (LET) irradiation are different than those induced by high LET irradiations. GM10115 cells were irradiated with low LET x-rays and high LET iron (Fe) ions and evaluated for DNA damage, cell survival and chromosomal instability. The cells were also evaluated for specific locus methylation of nuclear factor-kappa B (NFκB), tumor suppressor in lung cancer 1 (TSLC1) and cadherin 1 (CDH1) gene promoter regions, long interspersed nuclear element 1 (LINE-1) and Alu repeat element methylation, CpG and non-CpG global methylation and miRNA expression levels. Irradiated cells showed increased micronucleus induction and cell killing immediately following exposure, but were chromosomally stable at delayed times post-irradiation. At this same delayed time, alterations in repeat element and global DNA methylation and miRNA expression were observed. Analyses of DNA methylation predominantly showed hypomethylation, however hypermethylation was also observed. MiRNA shown to be altered in expression level after x-ray irradiation are involved in chromatin remodeling and DNA methylation. Different and higher incidence of epigenetic changes were observed after exposure to low LET x-rays than high LET Fe ions even though Fe ions elicited more chromosomal damage and cell killing. This study also shows that the irradiated cells acquire epigenetic changes even though they are chromosomally stable suggesting that epigenetic aberrations may arise in the cell without initiating RIGI.

Challenging nurse student selection policy: Using a lifeworld approach to explore the link between care experience and student values.

Science.gov (United States)

Scammell, Janet; Tait, Desiree; White, Sara; Tait, Michael

2017-10-01

This study uses a lifeworld perspective to explore beginning students' values about nursing. Internationally, increasing care demand, a focus on targets and evidence of dehumanized care cultures have resulted in scrutiny of practitioner values. In England, selection policy dictates that prospective nursing students demonstrate person-centred values and care work experience. However, there is limited recent evidence exploring values at programme commencement or the effect of care experience on values. Mixed method study. A total of 161 undergraduate nursing students were recruited in 2013 from one English university. Thematic content analysis and frequency distribution to reveal descriptive statistics were used. Statistical analysis indicated that most of the values identified in student responses were not significantly affected by paid care experience. Five themes were identified: How I want care to be; Making a difference; The value of learning; Perceived characteristics of a nurse; and Respecting our humanity. Students readily drew on their experience of living to identify person-centred values about nursing.

Potential proteins targeted by let-7f-5p in HeLa cells.

Science.gov (United States)

Wang, Yu; Chen, Xiujuan; Zhang, Yi; Song, Jiandong

2017-07-24

MicroRNAs are a class of small, endogenous, non-coding RNAs mediating posttranscriptional gene silencing. The current authors hypothesized that let-7f-5p is likely involved in cell invasion and proliferation by regulating the expression of target genes. The current study combined let-7f-5p with iTRAQ to assess its effect on gene expression in HeLa cells. Results indicated that 164 proteins were expressed at different levels in HeLa cells overexpressing let-7f-5p and negative controls and that 172 proteins were expressed at different levels in let-7f-5p-silenced HeLa cells and negative controls. Results indicated that let-7f-5p may suppress insulin-like growth factor 2 mRNA binding protein 1 (IGF2BP1) in HeLa cells.

Let us fish4tomorrow

OpenAIRE

J.D., Farrugia

2015-01-01

All over the world, governments and stakeholders are trying to cope with overfishing. Overfishing is when too much fish is caught which leads to an overall degradation of the marine ecosystem. It is the non-sustainable use of ocean resources. http://www.um.edu.mt/think/let-us-fish4tomorrow/

Exploring Uyghur University Students' Identities Constructed through Multilingual Practices in China

Science.gov (United States)

Guo, Xiaoyan; Gu, Mingyue

2018-01-01

This article explores how a cohort of tertiary-level Uyghur students contested and negotiated their identities through multilingual practices in the receiving community. Drawing upon interview data from fieldwork, this study indicates that these students experienced essentialist understandings and negative views in the host society. Participants…

Alienated and Disaffected Students: Exploring the Civic Capacity of "Outsiders" in Asian Societies

Science.gov (United States)

Kuang, Xiaoxue; Kennedy, Kerry John

2018-01-01

As an important group of students, the alienated and disaffected students are often overlooked in more general studies of civic education. Based on data from the International Civics and Citizenship Education Study (ICCS 2009), the study investigated alienated and disaffected students in Asia and explored the development of their civic attitudes.…

Exploring the experiences of novice clinical instructors in physical therapy clinical education: a phenomenological study.

Science.gov (United States)

Greenfield, B H; Bridges, P H; Phillips, T A; Drill, A N; Gaydosik, C D; Krishnan, A; Yandziak, H J

2014-12-01

To explore the perceptions of novice physical therapy clinical instructors (CIs) about their interactions and teaching behaviours with physical therapy students. A phenomenological approach using semi-structured interviews and a focus group. Six novice physical therapy CIs (less than two years as a CI and supervised fewer than three students) were recruited purposefully from a large metropolitan area in the USA. All participants were credentialed by the American Physical Therapy Association as CIs. Transcripts of interview data and focus group data were analysed using interpretative analysis for themes and subthemes. Participants viewed the transition of students from the classroom to the clinic as their primary role, using strategies of 'providing a way in', 'fostering critical thinking', 'finding a balance', 'overcoming barriers' and 'letting go'. While novice CIs showed skill in fostering student reflection and providing orientation, they struggled with student autonomy and balancing the competing obligations of patient care and clinical instruction. They expressed issues related to anxiety and lack of confidence. In the future, novice CIs could benefit from training and support in these areas. Copyright © 2014 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.

Using Photo-Elicitation with Native American Students to Explore Perceptions of the Physical Library

Directory of Open Access Journals (Sweden)

Karen Neurohr

2016-04-01

Full Text Available Abstract Objective – This research project explored Native American students’ perceptions of the Edmon Low Library at Oklahoma State University (OSU. The study sought to understand how Native American students perceived the role of the academic library in their lives, and which elements of the library students depicted and described as holding meaning for them. Methods – Photo-elicitation, a form of visual research and a participatory research method, was the primary method chosen to explore students’ perceptions of the library. To qualify for this study, students self-identified as Native American and as frequent library users. They also had completed three or more semesters of study at OSU. Five students followed a photo prompt for taking at least fifteen pictures of the library, then participated in two separate interviews with the primary researcher. Participants also completed a demographic/questionnaire form, answered semi-structured questions, and ranked the photos they took. Results – This study produced several emergent findings. First, students expressed uncertainty about the library’s books. Second, functional library tools such as express printers and library signage played a valuable role for facilitating student work. Third, the method of photo-elicitation was enjoyable for students and served as library discovery. Fourth, Native American resources and exhibits in the library had varied salience for students. Conclusion – Limited research focuses on Native American students in academic libraries, particularly on how students use and experience the library. Exploring how individual students who identify as Native American perceive the university library enhanced our understanding of how libraries in Predominantly White Institutions (PWIs can best serve and support students. This study provided insight into the method of photo-elicitation interviews. This research also provided practical benefits for student

Functional improvement of dystrophic muscle by repression of utrophin: let-7c interaction.

Directory of Open Access Journals (Sweden)

Manoj K Mishra

Full Text Available Duchenne muscular dystrophy (DMD is a fatal genetic disease caused by an absence of the 427kD muscle-specific dystrophin isoform. Utrophin is the autosomal homolog of dystrophin and when overexpressed, can compensate for the absence of dystrophin and rescue the dystrophic phenotype of the mdx mouse model of DMD. Utrophin is subject to miRNA mediated repression by several miRNAs including let-7c. Inhibition of utrophin: let-7c interaction is predicted to 'repress the repression' and increase utrophin expression. We developed and tested the ability of an oligonucleotide, composed of 2'-O-methyl modified bases on a phosphorothioate backbone, to anneal to the utrophin 3'UTR and prevent let-7c miRNA binding, thereby upregulating utrophin expression and improving the dystrophic phenotype in vivo. Suppression of utrophin: let-7c interaction using bi-weekly intraperitoneal injections of let7 site blocking oligonucleotides (SBOs for 1 month in the mdx mouse model for DMD, led to increased utrophin expression along with improved muscle histology, decreased fibrosis and increased specific force. The functional improvement of dystrophic muscle achieved using let7-SBOs suggests a novel utrophin upregulation-based therapeutic strategy for DMD.

LncRNA-LET inhibits cell viability, migration and EMT while induces apoptosis by up-regulation of TIMP2 in human granulosa-like tumor cell line KGN.

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Han, Qingfang; Zhang, Wenke; Meng, Jinlai; Ma, Li; Li, Aihua

2018-04-01

Polycystic ovary syndrome (PCOS) is a common endocrine disease characterized by hyperandrogenism, irregular menses, and polycystic ovaries. Several long non-coding RNAs (lncRNAs) are aberrantly expressed in PCOS patients; however, little is known about the effects of the lncRNA-low expression in tumor (lncRNA-LET) on PCOS. We aimed to explore the effects of lncRNA-LET on human granulosa-like tumor cell line, KGN. Expression of lncRNA-LET in normal IOSE80 cells and granulosa cells was determined by qRT-PCR. KGN cell viability, apoptosis and migration were measured by trypan blue exclusion method, flow cytometry assay and wound healing assay, respectively. TGF-β1 was used to induce epithelial-mesenchymal transition (EMT) process. LncRNA-LET expression and mRNA expressions of TIMP2 and EMT-related proteins were measured by qRT-PCR. Western blot analysis was used to measure the protein expression of apoptosis-related proteins, EMT-related proteins, TIMP2, and the proteins in the Wnt/β-catenin and Notch signaling pathways. lncRNA-LET was down-regulated in KGN cells, and its overexpression inhibited cell viability and migration, and promoted apoptosis in KGN cells. Overexpression of lncRNA-LET increased the expression of E-cadherin and decreased the expressions of N-cadherin and vimentin in KGN cells. These effects of lncRNA-LET on KGN cells were reversed by TIMP2 suppression. Overexpression of TIMP2 inhibited cell viability, migration and EMT process, and increased apoptosis by activating the Wnt/β-catenin and Notch pathways. Overexpression of lncRNA-LET inhibits cell viability, migration and EMT process, and increases apoptosis in KGN cells by up-regulating the expression of TIMP2 and activating the Wnt/β-catenin and notch signaling pathways. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Exploring Service Learning Outcomes in Students: A Mixed Methods Study for Nursing

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Martin, John F.

2017-01-01

This mixed methods study exploring student outcomes of service learning experiences is inter-disciplinary, near the intersection of higher education research, moral development, and nursing. The specific problem examined in this study is that service learning among university students is utilized by educators, but largely without a full…

Exploring Meaning of Active Learning with Millennial Nursing Students: A Phenomenological Study

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Szoka, Amy

2017-01-01

The purpose of this interpretive, phenomenological study was to explore and understand how millennial nursing students perceived their lived experiences of being active learners in an associate degree program and how it affected student learning outcomes and/or program satisfaction. The research questions guiding this study were based on…

Exploring Different Patterns of Love Attitudes among Chinese College Students

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Zeng, Xianglong; Pan, Yiqin; Zhou, Han; Yu, Shi; Liu, Xiangping

2016-01-01

Individual differences in love attitudes and the relationship between love attitudes and other variables in Asian culture lack in-depth exploration. This study conducted cluster analysis with data regarding love attitudes obtained from 389 college students in mainland China. The result of cluster analysis based on love-attitude scales distinguished four types of students: game players, rational lovers, emotional lovers, and absence lovers. These four groups of students showed significant differences in sexual attitudes and personality traits of deliberation and dutifulness but not self-discipline. The study’s implications for future studies on love attitudes in certain cultural groups were also discussed. PMID:27851784

Exploring Different Patterns of Love Attitudes among Chinese College Students.

Directory of Open Access Journals (Sweden)

Xianglong Zeng

Full Text Available Individual differences in love attitudes and the relationship between love attitudes and other variables in Asian culture lack in-depth exploration. This study conducted cluster analysis with data regarding love attitudes obtained from 389 college students in mainland China. The result of cluster analysis based on love-attitude scales distinguished four types of students: game players, rational lovers, emotional lovers, and absence lovers. These four groups of students showed significant differences in sexual attitudes and personality traits of deliberation and dutifulness but not self-discipline. The study's implications for future studies on love attitudes in certain cultural groups were also discussed.

On the problem of finding a suitable distribution of students to universities in Germany

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Schneider, Johannes J.; Hirtreiter, Christian; Morgenstern, Ingo

2009-10-01

For many years, the problem of how to distribute students to the various universities in Germany according to the preferences of the students has remained unsolved. Various approaches, like the centralized method to let a central agency organize the distribution to the various universities or the decentralized method to let the students apply directly at their preferred universities, turned out to lead to a significant fraction of frustrated students ending up at universities not being on their preference list or even not having a place to study at all. With our centralized approach, we are able to decrease the fraction of frustrated students as well as the bureaucratic expenses for applicants and universities drastically.

Exploring Students' Understanding of Ordinary Differential Equations Using Computer Algebraic System (CAS)

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Maat, Siti Mistima; Zakaria, Effandi

2011-01-01

Ordinary differential equations (ODEs) are one of the important topics in engineering mathematics that lead to the understanding of technical concepts among students. This study was conducted to explore the students' understanding of ODEs when they solve ODE questions using a traditional method as well as a computer algebraic system, particularly…

Markov Processes: Exploring the Use of Dynamic Visualizations to Enhance Student Understanding

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Pfannkuch, Maxine; Budgett, Stephanie

2016-01-01

Finding ways to enhance introductory students' understanding of probability ideas and theory is a goal of many first-year probability courses. In this article, we explore the potential of a prototype tool for Markov processes using dynamic visualizations to develop in students a deeper understanding of the equilibrium and hitting times…

LIN28 expression in malignant germ cell tumors down-regulates let-7 and increases oncogene levels

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Murray, Matthew J.; Saini, Harpreet K.; Siegler, Charlotte A.; Hanning, Jennifer E.; Barker, Emily M.; van Dongen, Stijn; Ward, Dawn M.; Raby, Katie L.; Groves, Ian J.; Scarpini, Cinzia G.; Pett, Mark R.; Thornton, Claire M.; Enright, Anton J.; Nicholson, James C.; Coleman, Nicholas

2013-01-01

Despite their clinico-pathologic heterogeneity, malignant germ-cell-tumors (GCTs) share molecular abnormalities that are likely to be functionally important. In this study, we investigated the potential significance of down-regulation of the let-7 family of tumor-suppressor microRNAs in malignant-GCTs. Microarray results from pediatric and adult samples (n=45) showed that LIN28, the negative-regulator of let-7 biogenesis, was abundant in malignant-GCTs, regardless of patient age, tumor site or histologic subtype. Indeed, a strong negative-correlation existed between LIN28 and let-7 levels in specimens with matched datasets. Low let-7 levels were biologically significant, since the sequence complementary to the 2-7nt common let-7 seed ‘GAGGUA’ was enriched in the 3′untranslated regions of mRNAs up-regulated in pediatric and adult malignant-GCTs, compared with normal gonads (a mixture of germ cells and somatic cells). We identified 27 mRNA targets of let-7 that were up-regulated in malignant-GCT cells, confirming significant negative-correlations with let-7 levels. Among 16 mRNAs examined in a largely independent set of specimens by qRT-PCR, we defined negative-associations with let-7e levels for six oncogenes, including MYCN, AURKB, CCNF, RRM2, MKI67 and C12orf5 (when including normal control tissues). Importantly, LIN28 depletion in malignant-GCT cells restored let-7 levels and repressed all of these oncogenic let-7 mRNA targets, with LIN28 levels correlating with cell proliferation and MYCN levels. Conversely, ectopic expression of let-7e was sufficient to reduce proliferation and down-regulate MYCN, AURKB and LIN28, the latter via a double-negative feedback loop. We concluded that the LIN28/let-7 pathway has a critical pathobiological role in malignant-GCTs and therefore offers a promising target for therapeutic intervention. PMID:23774216

Clinical placements and nursing students' career planning: a qualitative exploration.

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McKenna, Lisa; McCall, Louise; Wray, Natalie

2010-04-01

Many nursing students enter undergraduate programmes with preconceived ideas about their future nursing careers, and intend to practice in particular areas such as midwifery or paediatrics. Through clinical placements, students are exposed to different clinical areas and professional socialization is facilitated. However, little is known about the influence of clinical placements on students' career intentions. This paper reports nursing findings drawn from a large qualitative study conducted in Victoria, Australia that sought to explore the influence of health professional students' clinical placements on their future career intentions. Participants were invited to be involved in either face-to-face or focus group interviews depending upon their own preference. Thematic data analysis revealed three main themes: 're-affirming career choice', 'working in a particular area' and 'work location'. Findings from the study add to our understanding of factors influencing nursing students' planning for their future careers including the impact of clinical placements.

Patients' approaches to students' learning at a clinical education ward--an ethnographic study.

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Manninen, Katri; Henriksson, Elisabet Welin; Scheja, Max; Silén, Charlotte

2014-07-02

It is well known that patients' involvement in health care students' learning is essential and gives students opportunities to experience clinical reasoning and practice clinical skills when interacting with patients. Students encounter patients in different contexts throughout their education. However, looking across the research providing evidence about learning related to patient-student encounters reveals a lack of knowledge about the actual learning process that occurs in encounters between patients and students. The aim of this study was to explore patient-student encounters in relation to students' learning in a patient-centered health-care setting. An ethnographic approach was used to study the encounters between patients and students. The setting was a clinical education ward for nursing students at a university hospital with eight beds. The study included 10 observations with 11 students and 10 patients. The observer followed one or two students taking care of one patient. During the fieldwork observational and reflective notes were taken. After each observation follow-up interviews were conducted with each patient and student separately. Data were analyzed using an ethnographic approach. The most striking results showed that patients took different approaches in the encounters with students. When the students managed to create a good atmosphere and a mutual relationship, the patients were active participants in the students' learning. If the students did not manage to create a good atmosphere, the relationship became one-way and the patients were passive participants, letting the students practice on their bodies but without engaging in a dialogue with the students. Patient-student encounters, at a clinical education ward with a patient-centred pedagogical framework, can develop into either a learning relationship or an attending relationship. A learning relationship is based on a mutual relationship between patients and students resulting in patients

Let's tweet in Chinese! : Exploring how learners of Chinese as a foreign language self-direct their use of microblogging to learn Chinese

NARCIS (Netherlands)

Hsiao, A.; Broeder, Peter

2014-01-01

Twitter is becoming increasingly popular as a medium for language learning. This study explores self-directed learning via social interactions that use Twitter as an interactive learning environment. The participants in this study were thirty university students of Chinese as a foreign language at

Killing, letting die and euthanasia.

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Husak, D N

1979-12-01

Medical ethicists debate whether or not the moral assessment of cases of euthanasia should depend on whether the patient is 'killed' or 'allowed to die'. The usual presupposition is that a clear distinction between killing and letting die can be drawn so that this substantive question is not begged. I contend that the categorisation of cases of instances of killing rather than as instances of letting die depends in part on a prior moral assessment of the case. Hence is it trivially rather than substantively true that the distinction has moral significance. But even if a morally neutral (ie non-question begging) distinction could be drawn, its application to the euthanasia controversy is problematic. I illustrate the difficulties of employing this distinction to reach moral conclusions by critically discussing Philippa Foot's recent treatment of euthanasia. I conclude that even if an act of euthanasia is an instance of killing, and there exists a prima facie moral duty not to kill, and no more stringent duty overrides this duty, one still cannot determine such an act to be morally impermissible.

Killing, letting die and euthanasia.

Science.gov (United States)

Husak, D N

1979-01-01

Medical ethicists debate whether or not the moral assessment of cases of euthanasia should depend on whether the patient is 'killed' or 'allowed to die'. The usual presupposition is that a clear distinction between killing and letting die can be drawn so that this substantive question is not begged. I contend that the categorisation of cases of instances of killing rather than as instances of letting die depends in part on a prior moral assessment of the case. Hence is it trivially rather than substantively true that the distinction has moral significance. But even if a morally neutral (ie non-question begging) distinction could be drawn, its application to the euthanasia controversy is problematic. I illustrate the difficulties of employing this distinction to reach moral conclusions by critically discussing Philippa Foot's recent treatment of euthanasia. I conclude that even if an act of euthanasia is an instance of killing, and there exists a prima facie moral duty not to kill, and no more stringent duty overrides this duty, one still cannot determine such an act to be morally impermissible. PMID:541821

Exploring the challenges faced by polytechnic students

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Matore, Mohd Effendi @ Ewan Mohd; Khairani, Ahmad Zamri

2015-02-01

This study aims to identify other challenges besides those already faced by students, in seven polytechnics in Malaysia as a continuation to the previous research that had identified 52 main challenges faced by students using the Rasch Model. The explorative study focuses on the challenges that are not included in the Mooney Problem Checklist (MPCL). A total of 121 polytechnic students submitted 183 written responses through the open questions provided. Two hundred fifty two students had responded from a students' perspective on the dichotomous questions regarding their view on the challenges faced. The data was analysed qualitatively using the NVivo 8.0. The findings showed that students from Politeknik Seberang Perai (PSP) gave the highest response, which was 56 (30.6%) and Politeknik Metro Kuala Lumpur (PMKL) had the lowest response of 2 (1.09%). Five dominant challenges were identified, which were the English language (32, 17.5%), learning (14, 7.7%), vehicles (13, 7.1%), information technology and communication (ICT) (13, 7.1%), and peers (11, 6.0%). This article, however, focus on three apparent challenges, namely, English language, vehicles, as well as computer and ICT, as the challenges of learning and peers had been analysed in the previous MPCL. The challenge of English language that had been raised was regarding the weakness in commanding the aspects of speech and fluency. The computer and ICT challenge covered the weakness in mastering ICT and computers, as well as computer breakdowns and low-performance computers. The challenge of vehicles emphasized the unavailability of vehicles to attend lectures and go elsewhere, lack of transportation service in the polytechnic and not having a valid driving license. These challenges are very relevant and need to be discussed in an effort to prepare polytechnics in facing the transformational process of polytechnics.

MicroRNAs let-7b/i suppress human glioma cell invasion and migration by targeting IKBKE directly

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Tian, Yuan; Hao, Shaobo [Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin 300052 (China); Laboratory of Neuro-Oncology, Tianjin Neurological Institute, Tianjin 300052 (China); Key Laboratory of Neurotrauma, Variation and Regeneration, Ministry of Education and Tianjin Municipal Government (China); Ye, Minhua [Department of Neurosurgery, Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi Province 330006 (China); Zhang, Anling [Laboratory of Neuro-Oncology, Tianjin Neurological Institute, Tianjin 300052 (China); Key Laboratory of Neurotrauma, Variation and Regeneration, Ministry of Education and Tianjin Municipal Government (China); Nan, Yang [Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin 300052 (China); Wang, Guangxiu; Jia, Zhifan [Laboratory of Neuro-Oncology, Tianjin Neurological Institute, Tianjin 300052 (China); Key Laboratory of Neurotrauma, Variation and Regeneration, Ministry of Education and Tianjin Municipal Government (China); Yu, Kai; Guo, Lianmei [Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin 300052 (China); Pu, Peiyu [Laboratory of Neuro-Oncology, Tianjin Neurological Institute, Tianjin 300052 (China); Key Laboratory of Neurotrauma, Variation and Regeneration, Ministry of Education and Tianjin Municipal Government (China); Huang, Qiang, E-mail: huangqiang209@163.com [Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin 300052 (China); Zhong, Yue, E-mail: zhongyue2457@sina.com [Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin 300052 (China)

2015-03-06

We demonstrated that IKBKE is overexpressed in human gliomas and that the downregulation of IKBKE markedly inhibits the proliferative and invasive abilities of glioma cells, which is consistent with the results reported by several different research groups. Therefore, IKBKE represents a promising therapeutic target for the treatment of glioma. In the present study, we verified that the microRNAs let-7b and let-7i target IKBKE through luciferase assays and found that let-7b/i mimics can knock down IKBKE and upregulate E-cadherin through western blot analysis. Moreover, the expression levels of let-7b/i were significantly lower in glioma cell lines than that in normal brain tissues, as determined by quantitative real-time PCR. Furthermore, let-7b/i inhibit the invasion and migration of glioma cells, as determined through wound healing and Transwell assays. The above-mentioned data suggest that let-7b/i inhibit the invasive ability of glioma cells by directly downregulating IKBKE and indirectly upregulating E-cadherin. - Highlights: • Let-7b and let-7i are downregulated in glioma cell lines. • IKBKE is a target gene of let-7b/i. • Let-7b/i inhibit the invasion and migration of glioma cells. • Let-7b/i upregulate E-cadherin by downregulating IKBKE.

MicroRNAs let-7b/i suppress human glioma cell invasion and migration by targeting IKBKE directly

International Nuclear Information System (INIS)

Tian, Yuan; Hao, Shaobo; Ye, Minhua; Zhang, Anling; Nan, Yang; Wang, Guangxiu; Jia, Zhifan; Yu, Kai; Guo, Lianmei; Pu, Peiyu; Huang, Qiang; Zhong, Yue

2015-01-01

We demonstrated that IKBKE is overexpressed in human gliomas and that the downregulation of IKBKE markedly inhibits the proliferative and invasive abilities of glioma cells, which is consistent with the results reported by several different research groups. Therefore, IKBKE represents a promising therapeutic target for the treatment of glioma. In the present study, we verified that the microRNAs let-7b and let-7i target IKBKE through luciferase assays and found that let-7b/i mimics can knock down IKBKE and upregulate E-cadherin through western blot analysis. Moreover, the expression levels of let-7b/i were significantly lower in glioma cell lines than that in normal brain tissues, as determined by quantitative real-time PCR. Furthermore, let-7b/i inhibit the invasion and migration of glioma cells, as determined through wound healing and Transwell assays. The above-mentioned data suggest that let-7b/i inhibit the invasive ability of glioma cells by directly downregulating IKBKE and indirectly upregulating E-cadherin. - Highlights: • Let-7b and let-7i are downregulated in glioma cell lines. • IKBKE is a target gene of let-7b/i. • Let-7b/i inhibit the invasion and migration of glioma cells. • Let-7b/i upregulate E-cadherin by downregulating IKBKE

LET-effects in DNA

International Nuclear Information System (INIS)

Kraft, G.; Taucher-Scholz, G.; Heilmann, J.

1994-11-01

In this contribution, an introductory view on the physical properties of ions is given and the cellular response to high LET radiation is summarized. Then the measurements of strand break induction of DNA in solution and in intracellular DNA are reported and compared to cell survival. The possibility of changes in the quality of the lesions is discussed and finally the present status of model calculations in comparison to the experiments is given. (orig./HSI)

FORECASTING CAREER PLANNING OF STUDENT OF UNIVERSITY

Directory of Open Access Journals (Sweden)

Aleksandra Danilenko

2012-01-01

Full Text Available In this article the forecasting model of career planning of student of University. This model has an empirical nature and lets to control the process and the content of student learning taking into account of his individual characteristics and the predictions of his potential careers.

Exploring Race, Culture, and Family in the Identities of Mixed Heritage Students

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Johnston-Guerrero, Marc P.; Pecero, Veronica

2016-01-01

Family plays an integral role in racial and cultural socialization, yet how mixed heritage students understand the concepts of race and culture in relation to family is unclear. This qualitative study explored the interplay of race, culture, and family in the identity constructions of 25 mixed heritage students. Findings suggest the centrality of…

Exploring whether Students' Use of Labelling Depends upon the Type of Activity

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Bures, Eva Mary; Abrami, Philip C.; Schmid, Richard F.

2010-01-01

This paper explores a labelling feature designed to support higher-level online dialogue. It investigates whether students use labels less often during a structured online dialogue than during an unstructured one, and looks at students' reactions to labelling and to both types of tasks. Participants are from three successive course offerings of a…

14 CFR 151.47 - Performance of construction work: Letting of contracts.

Science.gov (United States)

2010-01-01

... Development Projects § 151.47 Performance of construction work: Letting of contracts. (a) Advertising required... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Performance of construction work: Letting... project, each contract for construction work on a project in the amount of more than $2,000 must be...

In real time: exploring nursing students' learning during an international experience.

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Afriyie Asenso, Barbara; Reimer-Kirkham, Sheryl; Astle, Barbara

2013-10-11

Abstract Nursing education has increasingly turned to international learning experiences to educate students who are globally minded and aware of social injustices in local and global communities. To date, research with international learning experiences has focused on the benefits for the students participating, after they have completed the international experience. The purpose of this qualitative study was to explore how nursing students learn during the international experience. The sample consisted of eight nursing students who enrolled in an international learning experience, and data were collected in "real time" in Zambia. The students were observed during learning activities and were interviewed three times. Three major themes emerged from the thematic analysis: expectations shaped students' learning, engagement facilitated learning, and critical reflection enhanced learning. Implications are discussed, related to disrupting media representations of Africa that shape students' expectations, and educational strategies for transformative learning and global citizenship.

Don't Let Osteoporosis Slow You Down | NIH MedlinePlus the Magazine

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... has never let anything stop her from doing what she loves, and she wasn't about to let osteoporosis keep her off the dance floor. It's that kind of spirit that led the National Osteoporosis Foundation (NOF) to ...

Keep it local (and final): Remnant preferences in ‘let alone’ ellipsis

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Harris, Jesse A.; Carlson, Katy

2015-01-01

The let alone construction (John can't run a mile, let alone a marathon) differs from standard coordination structures (with and or but) by requiring ellipsis of the second conjunct, e.g., a marathon is the remnant of an elided clause [John run a marathon]. In support of an ellipsis account, a corpus study of British and American English finds that let alone exhibits a Locality bias, as the second conjunct preferentially contrasts with the nearest lexical item of the same syntactic type. Two self-paced reading studies show that the Locality bias is active during online processing, but must be reconciled with indicators of semantic contrast and discourse information. Further, a sentence-rating study shows that the Locality bias interacts with a Finality bias that favors placing the let alone phrase at the end of a clause, which sometimes necessitates a non-local contrast. Together, the results show how a general bias in ellipsis for local contrasts is affected by discourse demands, such as the need for scalar contrast imposed by let alone, thereby offering a window into how possibly divergent syntactic and discourse constraints impact sentence processing. PMID:26085004

Radiation-induced epigenetic alterations after low and high LET irradiations

International Nuclear Information System (INIS)

Aypar, Umut; Morgan, William F.; Baulch, Janet E.

2011-01-01

Epigenetics, including DNA methylation and microRNA (miRNA) expression, could be the missing link in understanding radiation-induced genomic instability (RIGI). This study tests the hypothesis that irradiation induces epigenetic aberrations, which could eventually lead to RIGI, and that the epigenetic aberrations induced by low linear energy transfer (LET) irradiation are different than those induced by high LET irradiations. GM10115 cells were irradiated with low LET X-rays and high LET iron (Fe) ions and evaluated for DNA damage, cell survival and chromosomal instability. The cells were also evaluated for specific locus methylation of nuclear factor-kappa B (NFκB), tumor suppressor in lung cancer 1 (TSLC1) and cadherin 1 (CDH1) gene promoter regions, long interspersed nuclear element 1 (LINE-1) and Alu repeat element methylation, CpG and non-CpG global methylation and miRNA expression levels. Irradiated cells showed increased micronucleus induction and cell killing immediately following exposure, but were chromosomally stable at delayed times post-irradiation. At this same delayed time, alterations in repeat element and global DNA methylation and miRNA expression were observed. Analyses of DNA methylation predominantly showed hypomethylation, however hypermethylation was also observed. We demonstrate that miRNA expression levels can be altered after X-ray irradiation and that these miRNA are involved in chromatin remodeling and DNA methylation. A higher incidence of epigenetic changes was observed after exposure to X-rays than Fe ions even though Fe ions elicited more chromosomal damage and cell killing. This distinction is apparent at miRNA analyses at which only three miRNA involved in two major pathways were altered after high LET irradiations while six miRNA involved in five major pathways were altered after low LET irradiations. This study also shows that the irradiated cells acquire epigenetic changes suggesting that epigenetic aberrations may arise in the

Radiation-induced epigenetic alterations after low and high LET irradiations

Energy Technology Data Exchange (ETDEWEB)

Aypar, Umut, E-mail: uaypa001@umaryland.edu [Department of Radiation Oncology, Radiation Oncology Research Laboratory, University of Maryland School of Medicine, Baltimore, MD 21201 (United States); Morgan, William F. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Baulch, Janet E. [Department of Radiation Oncology, Radiation Oncology Research Laboratory, University of Maryland School of Medicine, Baltimore, MD 21201 (United States)

2011-02-10

Epigenetics, including DNA methylation and microRNA (miRNA) expression, could be the missing link in understanding radiation-induced genomic instability (RIGI). This study tests the hypothesis that irradiation induces epigenetic aberrations, which could eventually lead to RIGI, and that the epigenetic aberrations induced by low linear energy transfer (LET) irradiation are different than those induced by high LET irradiations. GM10115 cells were irradiated with low LET X-rays and high LET iron (Fe) ions and evaluated for DNA damage, cell survival and chromosomal instability. The cells were also evaluated for specific locus methylation of nuclear factor-kappa B (NF{kappa}B), tumor suppressor in lung cancer 1 (TSLC1) and cadherin 1 (CDH1) gene promoter regions, long interspersed nuclear element 1 (LINE-1) and Alu repeat element methylation, CpG and non-CpG global methylation and miRNA expression levels. Irradiated cells showed increased micronucleus induction and cell killing immediately following exposure, but were chromosomally stable at delayed times post-irradiation. At this same delayed time, alterations in repeat element and global DNA methylation and miRNA expression were observed. Analyses of DNA methylation predominantly showed hypomethylation, however hypermethylation was also observed. We demonstrate that miRNA expression levels can be altered after X-ray irradiation and that these miRNA are involved in chromatin remodeling and DNA methylation. A higher incidence of epigenetic changes was observed after exposure to X-rays than Fe ions even though Fe ions elicited more chromosomal damage and cell killing. This distinction is apparent at miRNA analyses at which only three miRNA involved in two major pathways were altered after high LET irradiations while six miRNA involved in five major pathways were altered after low LET irradiations. This study also shows that the irradiated cells acquire epigenetic changes suggesting that epigenetic aberrations may arise

let-7 miRNAs Can Act through Notch to Regulate Human Gliogenesis

Directory of Open Access Journals (Sweden)

M. Patterson

2014-11-01

Full Text Available It is clear that neural differentiation from human pluripotent stem cells generates cells that are developmentally immature. Here, we show that the let-7 plays a functional role in the developmental decision making of human neural progenitors, controlling whether these cells make neurons or glia. Through gain- and loss-of-function studies on both tissue and pluripotent derived cells, our data show that let-7 specifically regulates decision making in this context by regulation of a key chromatin-associated protein, HMGA2. Furthermore, we provide evidence that the let-7/HMGA2 circuit acts on HES5, a NOTCH effector and well-established node that regulates fate decisions in the nervous system. These data link the let-7 circuit to NOTCH signaling and suggest that this interaction serves to regulate human developmental progression.

A Simple, Student-Built Spectrometer to Explore Infrared Radiation and Greenhouse Gases

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Bruce, Mitchell R. M.; Wilson, Tiffany A.; Bruce, Alice E.; Bessey, S. Max; Flood, Virginia J.

2016-01-01

In this experiment, students build a spectrometer to explore infrared radiation and greenhouse gases in an inquiry-based investigation to introduce climate science in a general chemistry lab course. The lab is based on the exploration of the thermal effects of molecular absorption of infrared radiation by greenhouse and non-greenhouse gases. A…

Factors determinating the shape of survival curves of Escherichia coli cells irradiated by ionizing radiation with different LET. The dependence of the shape of survival curve on LET

International Nuclear Information System (INIS)

Kozubek, S.; Krasavin, E.A.; Fajsi, Ch.

1984-01-01

The dependence of the shape of bacterial sUrvival curve in the case of Escherichia coli Wild type, rec - and pol - mutants on linear energy transfer is considered. When increasing LET of the radiation the shouldered survival curves are transformed to exponential ones. In the case of sensitive mutants the transformation is observed for smaller values of LET. The dependence of cell sensitivity on LET calculated on the basis of Landau-Vavilov distribution is compared with earlier calculations. The comparison showed a good agreement between two methods of calculation for ions with 4 MeV per nucleon energy

The Role of Student Burnout in Predicting Future Burnout: Exploring the Transition from University to the Workplace

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Robins, Tamara G.; Roberts, Rachel M.; Sarris, Aspa

2018-01-01

Burnout is a significant problem in the workplace and recent research suggests burnout is also a growing concern for students. This study aimed to explore the transition from study to work, including exploring the impact of student burnout on work burnout. Australian health profession students (T1, n = 86; T2, n = 86; T3, n = 57) from the…

Student-Faculty Partnership in Explorations of Pedagogical Practice: A Threshold Concept in Academic Development

Science.gov (United States)

Cook-Sather, Alison

2014-01-01

Student-faculty partnerships position students as informants, participants, and change agents in collaboration with faculty members. Enacting one form of such collaboration, Bryn Mawr College's SaLT program pairs faculty members and undergraduate students in explorations of pedagogical practice. The program provides both context and case study for…

Exploring the transition from student to practitioner in diagnostic radiography

International Nuclear Information System (INIS)

Naylor, S.; Ferris, C.; Burton, M.

2016-01-01

Introduction: This study explores the expectations and experiences of newly qualified diagnostic radiographers during their transition into practice. Methods: This was a longitudinal study using interpretative phenomenological analysis methodology. Data were gathered from four students who participated in a focus group. This informed semi structured interviews with a further eight students who were interviewed prior to starting work and three times over the following twelve months. Results: Themes generated from the data included; experience, fitting in, and identity. Conclusion: This study brings to light the experiences of newly qualified diagnostic radiographers. The findings are open to theoretical generalizability and raise issues that may be used by academic staff in the preparation of students and managers who support newly qualified staff members. - Highlights: • Diagnostic radiographers are well prepared for most clinical practice. • Clinical education cannot fully prepare students for the reality of practice. • Being familiar with a hospital, and staff, reduces the stress of starting work. • Newly qualified radiographers struggle taking responsibility for students. • Professional identity is a key issue in the transition from student to practitioner.

Radiosensitivity of yeast cells as a function of radiation LET

International Nuclear Information System (INIS)

Lobachevskij, P.N.; Krasavin, E.A.

1988-01-01

A model is proposed for interpreting the radiosensitivity of yeast cells as a function of linear energy transfer (LET) of ionizing radiation. The model takes into account the role of repair processes in sensitivity of yeast cells to ionizing radiation of different LET. Two types of repair are discussed: (1) a nonspecific repair (characteristic of both haploid and diploid cells), and (2) a diploid - soecific repair (characteristic of diploid cells only)

Let's Take a Trip: Exploring the Effect of Listening Styles

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Dailey, Stephanie L.

2014-01-01

Listening is a core component of developing effective communication skills. Thus, a common objective of many basic communication courses is to help students become better listeners (Johnson & Long, 2007). Often, the teacher's goal is to show students that there are different listening styles or preferences and that people decode messages…

Student Needs and Motives When Attending a University: Exploring the Syrian Case

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Al-Fattal, Anas; Ayoubi, Rami

2013-01-01

This paper aims at exploring student needs and motives to pursue higher education in Syria. Based on the model of student buyer behavior developed by Kotler and Fox in 1995, the study focuses on the first step of this model, so-called motives. The study results are based on qualitative data collected by means of semi-structured styles of…

MicroRNA let-7b regulates neural stem cell proliferation and differentiation by targeting nuclear receptor TLX signaling.

Science.gov (United States)

Zhao, Chunnian; Sun, GuoQiang; Li, Shengxiu; Lang, Ming-Fei; Yang, Su; Li, Wendong; Shi, Yanhong

2010-02-02

Neural stem cell self-renewal and differentiation is orchestrated by precise control of gene expression involving nuclear receptor TLX. Let-7b, a member of the let-7 microRNA family, is expressed in mammalian brains and exhibits increased expression during neural differentiation. However, the role of let-7b in neural stem cell proliferation and differentiation remains unknown. Here we show that let-7b regulates neural stem cell proliferation and differentiation by targeting the stem cell regulator TLX and the cell cycle regulator cyclin D1. Overexpression of let-7b led to reduced neural stem cell proliferation and increased neural differentiation, whereas antisense knockdown of let-7b resulted in enhanced proliferation of neural stem cells. Moreover, in utero electroporation of let-7b to embryonic mouse brains led to reduced cell cycle progression in neural stem cells. Introducing an expression vector of Tlx or cyclin D1 that lacks the let-7b recognition site rescued let-7b-induced proliferation deficiency, suggesting that both TLX and cyclin D1 are important targets for let-7b-mediated regulation of neural stem cell proliferation. Let-7b, by targeting TLX and cyclin D1, establishes an efficient strategy to control neural stem cell proliferation and differentiation.

LET spectrometry with track etch detectors-Use in high-energy radiation fields

International Nuclear Information System (INIS)

Jadrnickova, I.; Spurny, F.

2008-01-01

For assessing the risk from ionizing radiation it is necessary to know not only the absorbed dose but also the quality of the radiation; radiation quality is connected with the physical quantity linear energy transfer (LET). One of the methods of determination of LET is based on chemically etched track detectors. This contribution concerns with a spectrometer of LET based on the track detectors and discusses some results obtained at: ·high-energy radiation reference field created at the SPS accelerator at CERN; and ·onboard of International Space Station where track-etch based LET spectrometer has been exposed 273 days during 'Matrjoshka - R' experiment. Results obtained are compared with the results of studies at some lower-energy neutron sources; some conclusions on the registrability of neutrons and the ability of this spectrometer to determine dose equivalent in high-energy radiation fields are formulated

Mutational influences of low-dose and high let ionizing radiation in drosophila melanogaster

Science.gov (United States)

Lei, Huang; Fanjun, Kong; Sun, Yeqing

For cosmic environment consists of a varying kinds of radiation particles including high Z and energy ions which was charactered with low-dose and high RBE, it is important to determine the possible biofuctions of high LET radiation on human beings. To analyse the possible effectes of mutational influences of low-dose and high-LET ionizing radiation, wild fruit flies drosophila melanogaster were irradiated by 12C6+ ions in two LET levels (63.3 and 30 keV/µum) with different low doses from 2mGy to 2000mGy (2, 20, 200, 2000mGy) in HIRFL (Heavy ion radiation facility laboratory, lanzhou, China).In the same LET value group, the average polymorphic frequency was elevated along with adding doses of irradation, the frequency in 2000 mGy dose samples was significantly higher than other samples (p<0.01).These results suggest that genomic DNA sequence could be effected by low-dose and high-LET ionizing radiation, the irradiation dose is an important element in genomic mutation frequency origination.

mBAND analysis for high- and low-LET radiation-induced chromosome aberrations: A review

Energy Technology Data Exchange (ETDEWEB)

Hada, Megumi, E-mail: megumi.hada-1@nasa.gov [NASA Johnson Space Center, Houston, TX 77058 (United States); Universities Space Research Association, Houston, TX 77058 (United States); Wu Honglu; Cucinotta, Francis A. [NASA Johnson Space Center, Houston, TX 77058 (United States)

2011-06-03

During long-term space travel or cancer therapy, humans are exposed to high linear energy transfer (LET) energetic heavy ions. High-LET radiation is much more effective than low-LET radiation in causing various biological effects, including cell inactivation, genetic mutations, cataracts and cancer induction. Most of these biological endpoints are closely related to chromosomal damage, and cytogenetic damage can be utilized as a biomarker for radiation insults. Epidemiological data, mainly from survivors of the atomic bomb detonations in Japan, have enabled risk estimation from low-LET radiation exposures. The identification of a cytogenetic signature that distinguishes high- from low-LET exposure remains a long-term goal in radiobiology. Recently developed fluorescence in situ hybridization (FISH)-painting methodologies have revealed unique endpoints related to radiation quality. Heavy-ions induce a high fraction of complex-type exchanges, and possibly unique chromosome rearrangements. This review will concentrate on recent data obtained with multicolor banding in situ hybridization (mBAND) methods in mammalian cells exposed to low- and high-LET radiations. Chromosome analysis with mBAND technique allows detection of both inter- and intrachromosomal exchanges, and also distribution of the breakpoints of aberrations.

Exploring the Views of Students on the Use of Facebook in University Teaching and Learning

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Donlan, Leah

2014-01-01

Facebook use among students is almost ubiquitous; however, its use for formal academic purposes remains contested. Through an online survey monitoring student use of module Facebook pages and focus groups, this study explores students' current academic uses of Facebook and their views on using Facebook within university modules. Students reported…

Social Cognitive Career Theory and Middle School Student Career Exploration

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Sickinger, Pamela H.

2013-01-01

Within the framework of social cognitive career theory, social cognitive career variables, demographic variables, and the contextual variable, parent support, were examined to determine their predictive value for eighth-grade students' career exploration behavior. Results suggest that the social cognitive career variable, intentions/goals,…

Exploring Regional and Institutional Factors of International Students' Dropout: The South Korea Case

Science.gov (United States)

Jung, Jisun; Kim, Yangson

2018-01-01

With an increasing number of international students in South Korea, the issue of retaining these students and reducing their dropout rates has become important. This study explores the multilevel factors that affect the institutional dropout rate among international students in Korea. The research questions are as follows: (a) to what extent do…

Prophage λ induction by ionizing radiation of different LETs

International Nuclear Information System (INIS)

Bonev, M.N.; Kozubek, S.; Krasavin, E.A.; Amirtaev, K.G.

1988-01-01

The λ prophage induction caused by γ-irradiation and accelerated heavy ions with different LET was studied in variety Escherichia coli strains. The induction frequency on the dose I(D) shaped a curve with a maximum in the strains which possess recA + /lexA + genotype. The inductivity of these strains increases as well as LET and an alteration poor → rich media does it. Unlike I(D) for recA + /lexA + , the dependence I(D) for recA, lexA and recBC strains was a constant. 15 refs.; 6 figs.; 3 tabs

TH-CD-209-06: LET-Based Adjustment of IMPT Plans Using Prioritized Optimization

Energy Technology Data Exchange (ETDEWEB)

Unkelbach, J; Giantsoudi, D; Paganetti, H [Massachusetts General Hospital, Boston, MA (United States); Botas, P [Massachusetts General Hospital, Boston, MA (United States); Heidelberg University, Heidelberg, DE (Germany); Qin, N; Jia, X [The University of Texas Southwestern Medical Ctr, Dallas, TX (United States)

2016-06-15

Purpose: In-vitro experiments suggest an increase in proton relative biological effectiveness (RBE) towards the end of range. However, proton treatment planning and dose reporting for clinical outcome assessment has been based on physical dose and constant RBE. Therefore, treatment planning for intensity-modulated proton therapy (IMPT) is unlikely to transition radically to pure RBE-based planning. We suggest a hybrid approach where treatment plans are initially created based on physical dose constraints and prescriptions, and are subsequently altered to avoid high linear energy transfer (LET) in critical structures while limiting the degradation of the physical dose distribution. Methods: To allow fast optimization based on dose and LET we extended a GPU-based Monte-Carlo code towards providing dose-averaged LET in addition to dose for all pencil beams. After optimizing an initial IMPT plan based on physical dose, a prioritized optimization scheme is used to modify the LET distribution while constraining the physical dose objectives to values close to the initial plan. The LET optimization step is performed based on objective functions evaluated for the product of physical dose and LET (LETxD). To first approximation, LETxD represents a measure of the additional biological dose that is caused by high LET. Regarding optimization techniques, LETxD has the advantage of being a linear function of the pencil beam intensities. Results: The method is applicable to treatments where serial critical structures with maximum dose constraint are located in or near the target. We studied intra-cranial tumors (high-grade meningiomas, base-of-skull chordomas) where the target (CTV) overlaps with the brainstem and optic structures. Often, high LETxD in critical structures can be avoided while minimally compromising physical dose planning objectives. Conclusion: LET-based re-optimization of IMPT plans represents a pragmatic approach to bridge the gap between purely physical dose

Exploring lecturers' views of first-year health science students' misconceptions in biomedical domains.

Science.gov (United States)

Badenhorst, Elmi; Mamede, Sílvia; Hartman, Nadia; Schmidt, Henk G

2015-05-01

Research has indicated that misconceptions hamper the process of knowledge construction. Misconceptions are defined as persistent ideas not supported by current scientific views. Few studies have explored how misconceptions develop when first year health students conceptually move between anatomy and physiology to construct coherent knowledge about the human body. This explorative study analysed lecturers' perceptions of first-year health science students' misconceptions in anatomy and physiology to gain a deeper understanding of how and why misconceptions could potentially arise, by attempting to link sources of misconceptions with four schools of thought, namely theories on concept formation, complexity, constructivism and conceptual change. This was a qualitative study where ten lecturers involved in teaching anatomy and physiology in the health science curricula at the University of Cape Town were interviewed to explore perceptions of students' misconceptions. Analytical induction was used to uncover categories within the interview data by using a coding system. A deeper analysis was done to identify emerging themes that begins to explore a theoretical understanding of why and how misconceptions arise. Nine sources of misconceptions were identified, including misconceptions related to language, perception, three dimensional thinking, causal reasoning, curricula design, learning styles and moving between macro and micro levels. The sources of misconceptions were then grouped together to assist educators with finding educational interventions to overcome potential misconceptions. This explorative study is an attempt in theory building to understand what is at the core of biomedical misconceptions. Misconceptions identified in this study hold implications for educators as not all students have the required building blocks and cognitive skills to successfully navigate their way through biomedical courses. Theoretical insight into the sources of misconceptions can

Secondary School Students' Misconceptions about Photosynthesis and Plant Respiration: Preliminary Results

Science.gov (United States)

Svandova, Katerina

2014-01-01

The study investigated the common misconceptions of lower secondary school students regarding the concepts of photosynthesis and plant respiration. These are abstract concepts which are difficult to comprehend for adults let alone for lower secondary school students. Research of the students misconceptions are conducted worldwide. The researches…

First-Year Female Students: Perceptions of Friendship.

Science.gov (United States)

Ishler, Jennifer L. Crissman; Schreiber, Staci

2002-01-01

Examined 91 first-year female students' perceptions of their pre-college and new collegiate friendships. Found that they have difficulty letting go of pre-college friendships and investing in new friendships. (EV)

The Othering in Kazuo Ishiguro’s Never Let Me Go

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Matava Vichiensing

2017-08-01

Full Text Available In this article, I will investigate the concept of ‘othering’ originally as part of a post-colonial theory. This concept is interested in many academic areas, including a literary study. In Kazuo Ishiguro’s novel Never Let Me Go is about human clones raised for organs. The clones are excluded and discriminated to be ‘the other’ from the normal people. The manifestations of othering in Never Let Me Go can be presented in the forms of linguistic features, indoctrination, objectification, and assimilation. Although the othering phenomenon can be found in the reality, it can be appeared in literary texts as well. The findings show that the study of Kazuo Ishiguro’s Never Let Me Go helps us to understand and aware of how the negative consequences of the othering process affect undesirable treatments in the society as a whole.

Uncovering Students' Environmental Identity: An Exploration of Activities in an Environmental Science Course

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Blatt, Erica

2014-01-01

This study at a public high school in the Northeastern United States explores how students' environmental identities are affected by various activities in an Environmental Science course. Data was collected as part of an ethnographic study involving an Environmental Science teacher and her tenth-twelfth grade students. The results focus on…

Exploring the Relationship between Academic Dishonesty and Moral Development in Law School Students

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Edmondson, Macey Lynd

2013-01-01

This mixed methods study explored whether a relationship existed between moral development and dishonest academic behaviors in law students. The quantitative portion of the study utilized a survey adapted from James Rest's Defining Issues Test and Donald McCabe's Academic Integrity Survey. Law students were solicited by email from two public…

Exploring the Limitations of Measures of Students' Socioeconomic Status (SES)

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Dickinson, Emily R.; Adelson, Jill L.

2014-01-01

This study uses a nationally representative student dataset to explore the limitations of commonly used measures of socioeconomic status (SES). Among the identified limitations are patterns of missing data that conflate the traditional conceptualization of SES with differences in family structure that have emerged in recent years and a lack of…

Exploring Work Values: Helping Students Articulate Their Good (Work) Life

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Carlstrom, Aaron H.; Hughey, Kenneth F.

2014-01-01

The current article builds on "Living the Good (Work) Life: Implications of General Values for Work Values" (Carlstrom, 2011) by presenting ways to address work values in career advising. The following questions are addressed in the current article: When should students explore work values in career advising? What career development and…

Let-7b Regulates Myoblast Proliferation by Inhibiting IGF2BP3 Expression in Dwarf and Normal Chicken

Science.gov (United States)

Lin, Shumao; Luo, Wen; Ye, Yaqiong; Bekele, Endashaw J.; Nie, Qinghua; Li, Yugu; Zhang, Xiquan

2017-01-01

The sex-linked dwarf chicken is caused by the mutation of growth hormone receptor (GHR) gene and characterized by shorter shanks, lower body weight, smaller muscle fiber diameter and fewer muscle fiber number. However, the precise regulatory pathways that lead to the inhibition of skeletal muscle growth in dwarf chickens still remain unclear. Here we found a let-7b mediated pathway might play important role in the regulation of dwarf chicken skeletal muscle growth. Let-7b has higher expression in the skeletal muscle of dwarf chicken than in normal chicken, and the expression of insulin-like growth factor 2 mRNA binding protein 3 (IGF2BP3), which is a translational activator of IGF2, showed opposite expression trend to let-7b. In vitro cellular assays validated that let-7b directly inhibits IGF2BP3 expression through binding to its 3′UTR region, and the protein level but not mRNA level of IGF2 would be reduced in let-7b overexpressed chicken myoblast. Let-7b can inhibit cell proliferation and induce cell cycle arrest in chicken myoblast through let-7b-IGF2BP3-IGF2 signaling pathway. Additionally, let-7b can also regulate skeletal muscle growth through let-7b-GHR-GHR downstream genes pathway, but this pathway is non-existent in dwarf chicken because of the deletion mutation of GHR 3′UTR. Notably, as the loss binding site of GHR for let-7b, let-7b has enhanced its binding and inhibition on IGF2BP3 in dwarf myoblast, suggesting that the miRNA can balance its inhibiting effect through dynamic regulate its binding to target genes. Collectively, these results not only indicate that let-7b can inhibit skeletal muscle growth through let-7b-IGF2BP3-IGF2 signaling pathway, but also show that let-7b regulates myoblast proliferation by inhibiting IGF2BP3 expression in dwarf and normal chickens. PMID:28736533

Web site lets solar scientists inform and inspire students

Science.gov (United States)

Hauck, Karin

2012-07-01

Where on the Web can a middle school girl ask a female solar scientist about solar storms, the course and behavior of charged solar particles, and the origin of the Sun's dynamo—and also find out what the scientist was like as a child, whether the scientist has tattoos or enjoys snowboarding, what she likes and dislikes about her career, and how she balances her energy for work and family life? These kinds of exchanges happen at Solar Week (http://www.solarweek.org; see Figure 1). Established in 2000, Solar Week is an online resource for middle and lower high school students about the science of the Sun, sponsored by the Center for Science Education at the Space Sciences Laboratory (CSE@SSL) at the University of California, Berkeley (UC Berkeley). The Web site's goals are to educate students about the Sun and solar physics and to encourage future careers in science—especially for girls. One way is by giving solar scientists the chance to be relatable role models, to answer students' questions, and to share their experiences in an online forum.

let-7 Modulates Chromatin Configuration and Target Gene Repression through Regulation of the ARID3B Complex

Directory of Open Access Journals (Sweden)

Tsai-Tsen Liao

2016-01-01

Full Text Available Let-7 is crucial for both stem cell differentiation and tumor suppression. Here, we demonstrate a chromatin-dependent mechanism of let-7 in regulating target gene expression in cancer cells. Let-7 directly represses the expression of AT-rich interacting domain 3B (ARID3B, ARID3A, and importin-9. In the absence of let-7, importin-9 facilitates the nuclear import of ARID3A, which then forms a complex with ARID3B. The nuclear ARID3B complex recruits histone demethylase 4C to reduce histone 3 lysine 9 trimethylation and promotes the transcription of stemness factors. Functionally, expression of ARID3B is critical for the tumor initiation in let-7-depleted cancer cells. An inverse association between let-7 and ARID3A/ARID3B and prognostic significance is demonstrated in head and neck cancer patients. These results highlight a chromatin-dependent mechanism where let-7 regulates cancer stemness through ARID3B.

Cytotoxic and mutagenic effects of high let charged particles on human skin fibroblasts

International Nuclear Information System (INIS)

Tsuboi, Koji.; Park, M.S.; Chen, D.J.; Yang, T.C.

1992-01-01

Cytotoxic and mutagenic effects of high LET charged particles were quantitatively measured using primary cultures of human skin fibroblasts. The span of LETs selected were from 25 keV/μm(330 MeV/u) to 920 keV/μm (600 MeV/u). Mutations were scored at the hypoxanthine-guanine phosphoribosyl transferase (HPRT) locus using 6-thioguanine (6-TG) for selection. Exposure to these high LET charged particles resulted in exponential survival curves whereas mutant induction was fitted by a linear model. The Relative Biological Effect (RBE) for cell-killing ranged from 3.73 to 1.25, while that for mutant induction ranged from 5.74 to 0.48. Maximum RBE values were obtained at the LET of 150 keV/μm. The inactivation cross-section (σ i ) and the action cross-section for mutant induction (σ m ) ranged from 2.2 to 92.0 μm 2 and 0.09 to 5.56 x 10 -3 μm 2 respectively, the maximum values were obtained by 56 Fe with an LET of 200 keV/μm. The mutagenicity (σ m /σ i ) ranged from 2.05 to 7.99 x 10 -5 with the maximum value at 150 keV/μm. Furthermore, the results of multiplex polymerase chain reaction (PCR) of some of the mutants induced by charged particles indicate that higher LET beams are more likely to cause larger deletions in the hprt locus. (author)

Research with School Students: Four Innovative Methods Used to Explore Effective Teaching

Directory of Open Access Journals (Sweden)

Jessica Faye Heal

2015-03-01

Full Text Available This article outlines four research methods we’ve employed to enhance how students from low-income backgrounds engage in research exploring effective teaching. It firstly outlines the need to be innovative, drawing Article 12 of the United Nations Convention on the Rights of the Child, and then moves on to explain two methods that scaffold a semi-structured interview, one child-led classroom tour and finally a creative ‘draw and tell’ approach. It argues that these methods are successful because they disrupt the researcher-participant power imbalance using the following techniques: Familiarity to the student, empowering the student to be an expert, and giving the student choice.

Let7a involves in neural stem cell differentiation relating with TLX level.

Science.gov (United States)

Song, Juhyun; Cho, Kyoung Joo; Oh, Yumi; Lee, Jong Eun

2015-07-10

Neural stem cells (NSCs) have the potential for differentiation into neurons known as a groundbreaking therapeutic solution for central nervous system (CNS) diseases. To resolve the therapeutic efficiency of NSCs, recent researchers have focused on the study on microRNA's role in CNS. Some micro RNAs have been reported significant functions in NSC self-renewal and differentiation through the post-transcriptional regulation of neurogenesis genes. MicroRNA-Let7a (Let7a) has known as the regulator of diverse cellular mechanisms including cell differentiation and proliferation. In present study, we investigated whether Let7a regulates NSC differentiation by targeting the nuclear receptor TLX, which is an essential regulator of NSC self-renewal, proliferation and differentiation. We performed the following experiments: western blot analysis, TaqMan assay, RT-PCR, and immunocytochemistry to confirm the alteration of NSCs. Our data showed that let7a play important roles in controlling NSC fate determination. Thus, manipulating Let-7A and TLX could be a novel strategy to enhance the efficiency of NSC's neuronal differentiation for CNS disorders. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

High energy ion irradiation effects on polymer materials. LET dependence of G value of scission of polymethylmethacrylate (PMMA)

Energy Technology Data Exchange (ETDEWEB)

Kudoh, H; Sasuga, T; Seguchi, T [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

1997-03-01

Linear energy transfer (LET) dependence on the probability of main chain scission of polymethylmethacrylate (PMMA) was investigated. The probability was obtained from decreases in molecular weight measured by the gel permeation chromatography (GPC), and LET was evaluated by TRIM code. The scission probability as a function of LET was almost constant in the low LET, and decreased in the high LET ion irradiation. The mechanism was interpreted from the model of spur-overlapping along an ion`s path. (author)

Let-7b-mediated suppression of basigin expression and metastasis in mouse melanoma cells

International Nuclear Information System (INIS)

Fu, Tzu-Yen; Chang, Chia-Che; Lin, Chun-Ting; Lai, Cong-Hao; Peng, Shao-Yu; Ko, Yi-Ju; Tang, Pin-Chi

2011-01-01

Basigin (Bsg), also called extracellular matrix metalloproteinase inducer (EMMPRIN), is highly expressed on the surface of tumor cells and stimulates adjacent fibroblasts or tumor cells to produce matrix metalloproteinases (mmps). It has been shown that Bsg plays an important role in growth, development, cell differentiation, and tumor progression. MicroRNAs (miRNAs) are a class of short endogenous non-protein coding RNAs of 20-25 nucleotides (nt) that function as post-transcriptional regulators of gene expression by base-pairing to their target mRNAs and thereby mediate cleavage of target mRNAs or translational repression. In this study, let-7b, one of the let-7 family members, was investigated for its effect on the growth and invasiveness of the mouse melanoma cell line B16-F10. We have shown that let-7b can suppress the expression of Bsg in B16-F10 cells and also provided evidence that this suppression could result in the indirect suppression of mmp-9. The ability of B16-F10 cells transfected with let-7b to invade or migrate was significantly reduced. In addition, let-7b transfected B16-F10 cells displayed an inhibition of both cellular proliferation and colony formation. Furthermore, it was shown that the overexpression of let-7b in B16-F10 cells could reduce lung metastasis. Taken together, the present study identifies let-7b as a tumor suppressor that represses cancer cell proliferation and migration as well as tumor metastasis in mouse melanoma cells.

Let-7b-mediated suppression of basigin expression and metastasis in mouse melanoma cells

Energy Technology Data Exchange (ETDEWEB)

Fu, Tzu-Yen [Department of Animal Science, National Chung Hsing University, 250 Kuo Kuang Road, Taichung 40227, Taiwan (China); Chang, Chia-Che [Institute of Biomedical Sciences, National Chung Hsing University, 250 Kuo Kuang Road, Taichung 40227, Taiwan (China); Graduate Institute of Basic Medical Science, China Medical University, 91 Hsueh Shih Road, Taichung 40402, Taiwan (China); Lin, Chun-Ting [Department of Animal Science, National Chung Hsing University, 250 Kuo Kuang Road, Taichung 40227, Taiwan (China); Lai, Cong-Hao [Institute of Biomedical Sciences, National Chung Hsing University, 250 Kuo Kuang Road, Taichung 40227, Taiwan (China); Department of Life Sciences, National Chung Hsing University, 250 Kuo Kuang Road, Taichung 40227, Taiwan (China); Peng, Shao-Yu; Ko, Yi-Ju [Department of Animal Science, National Chung Hsing University, 250 Kuo Kuang Road, Taichung 40227, Taiwan (China); Tang, Pin-Chi, E-mail: pctang@dragon.nchu.edu.tw [Department of Animal Science, National Chung Hsing University, 250 Kuo Kuang Road, Taichung 40227, Taiwan (China)

2011-02-15

Basigin (Bsg), also called extracellular matrix metalloproteinase inducer (EMMPRIN), is highly expressed on the surface of tumor cells and stimulates adjacent fibroblasts or tumor cells to produce matrix metalloproteinases (mmps). It has been shown that Bsg plays an important role in growth, development, cell differentiation, and tumor progression. MicroRNAs (miRNAs) are a class of short endogenous non-protein coding RNAs of 20-25 nucleotides (nt) that function as post-transcriptional regulators of gene expression by base-pairing to their target mRNAs and thereby mediate cleavage of target mRNAs or translational repression. In this study, let-7b, one of the let-7 family members, was investigated for its effect on the growth and invasiveness of the mouse melanoma cell line B16-F10. We have shown that let-7b can suppress the expression of Bsg in B16-F10 cells and also provided evidence that this suppression could result in the indirect suppression of mmp-9. The ability of B16-F10 cells transfected with let-7b to invade or migrate was significantly reduced. In addition, let-7b transfected B16-F10 cells displayed an inhibition of both cellular proliferation and colony formation. Furthermore, it was shown that the overexpression of let-7b in B16-F10 cells could reduce lung metastasis. Taken together, the present study identifies let-7b as a tumor suppressor that represses cancer cell proliferation and migration as well as tumor metastasis in mouse melanoma cells.

Influence of Career Exploration Process Behaviors on Agriculture Students' Level of Career Certainty

Science.gov (United States)

Esters, Levon T.

2008-01-01

The purpose of this study was to determine the extent to which career exploration process behaviors influence the level of career certainty of agriculture students. Data were gathered from 181 freshmen and 131 senior students enrolled in the College of Agriculture and Life Sciences at Iowa State University. Career certainty was assessed using…

Exploring perceptions of the educational environment among undergraduate physiotherapy students.

Science.gov (United States)

Palmgren, Per J; Lindquist, Ingrid; Sundberg, Tobias; Nilsson, Gunnar H; Laksov, Klara B

2014-07-19

The aim of this study was to explore areas of strength and weakness in the educational environment as perceived by undergraduate physiotherapy students and to investigate these areas in relation to the respondents' demographic characteristics. This study utilized a cross-sectional study design and employed the Dundee Ready Education Environment Measure, a 50-item, self-administered inventory relating to a variety of topics directly pertinent to educational environments. Convenience sampling was used, and the scores were compared across demographic variables. All undergraduate physiotherapy students in their first five terms of the programme in a major Swedish university were invited to participate in the study. A total of 222 students (80%) completed the inventory. With an overall score of 150/200 (75%), the students rated the educational environment in this institution as "more positive than negative". Two items consistently received deprived scores - authoritarian teachers and teaching with an overemphasis on factual learning. Students in term 4 differed significantly from others, and students with earlier university education experience perceived the atmosphere more negatively than their counterparts. There were no significant differences with regards to other demographic variables. This study provides valuable insight into how undergraduate physiotherapy students perceive their educational environment. In general, students perceived that their educational programme fostered a sound educational environment. However, some areas require remedial measures in order to enhance the educational experience.

Harderian Gland Tumorigenesis: Low-Dose and LET Response

Energy Technology Data Exchange (ETDEWEB)

Chang, Polly Y. [SRI International, Menlo Park, CA (United States). Biosciences Div.; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Life Sciences Div.; Cucinotta, Francis A. [Univ. of Nevada, Las Vegas, NV (United States). Dept. of Health Physics and Diagnostic Sciences; Bjornstad, Kathleen A. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Life Sciences Div.; Bakke, James [SRI International, Menlo Park, CA (United States). Biosciences Div.; Rosen, Chris J. [SRI International, Menlo Park, CA (United States). Biosciences Div.; Du, Nicholas [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Life Sciences Div.; Fairchild, David G. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Life Sciences Div.; Cacao, Eliedonna [Univ. of Nevada, Las Vegas, NV (United States). Dept. of Health Physics and Diagnostic Sciences; Blakely, Eleanor A. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Life Sciences Div.

2016-04-19

Increased cancer risk remains a primary concern for travel into deep space and may preclude manned missions to Mars due to large uncertainties that currently exist in estimating cancer risk from the spectrum of radiations found in space with the very limited available human epidemiological radiation-induced cancer data. Existing data on human risk of cancer from X-ray and gamma-ray exposure must be scaled to the many types and fluences of radiations found in space using radiation quality factors and dose-rate modification factors, and assuming linearity of response since the shapes of the dose responses at low doses below 100 mSv are unknown. The goal of this work was to reduce uncertainties in the relative biological effect (RBE) and linear energy transfer (LET) relationship for space-relevant doses of charged-particle radiation-induced carcinogenesis. The historical data from the studies of Fry et al. and Alpen et al. for Harderian gland (HG) tumors in the female CB6F1 strain of mouse represent the most complete set of experimental observations, including dose dependence, available on a specific radiation-induced tumor in an experimental animal using heavy ion beams that are found in the cosmic radiation spectrum. However, these data lack complete information on low-dose responses below 0.1 Gy, and for chronic low-dose-rate exposures, and there are gaps in the LET region between 25 and 190 keV/μm. In this study, we used the historical HG tumorigenesis data as reference, and obtained HG tumor data for 260 MeV/u silicon (LET ~70 keV/μm) and 1,000 MeV/u titanium (LET ~100 keV/μm) to fill existing gaps of data in this LET range to improve our understanding of the dose-response curve at low doses, to test for deviations from linearity and to provide RBE estimates. Animals were also exposed to five daily fractions of 0.026 or 0.052 Gy of 1,000 MeV/u titanium ions to simulate chronic exposure, and HG tumorigenesis from this fractionated study were compared to the

Exploring and Leveraging Chinese International Students' Strengths for Success

Science.gov (United States)

He, Ye; Hutson, Bryant

2018-01-01

This study used an Appreciative Education framework to explore the strengths of Chinese international students and to identify areas where support is needed during their transition to U.S. higher education settings. Using a convergent mixed methods design with data collected from surveys, interviews and focus groups, the complex nature of the…

Analysis of Mongolian Students' Common Translation Errors and Its Solutions

Science.gov (United States)

Zhao, Changhua

2013-01-01

In Inner Mongolia, those Mongolian students face lots of difficulties in learning English. Especially the English translation ability of Mongolian students is a weak point. It is worth to think a problem that how to let our students use the English freely on a certain foundation. This article investigates the problems of Mongolian English learners…

Exploring the views of students on the use of Facebook in university teaching and learning

OpenAIRE

Donlan, Leah

2012-01-01

Facebook use among students is almost ubiquitous; however, its use for formal academic purposes remains contested. Through an online survey monitoring student use of module Facebook pages and focus groups, this study explores students' current academic uses of Facebook and their views on using Facebook within university modules. Students reported using Facebook for academic purposes, notably peer-peer communication around group work and assessment - a use not always conceptualised by students...

Combined chemo/radiotherapy of cancer: present state and prospects for use with high-LET radiotherapy

International Nuclear Information System (INIS)

Phillips, T.L.

1979-01-01

Cytotoxic chemotherapy added to low-LET radiotherapy has improved survival and in some cases local control. In some instances the combination has yielded increased normal tissue damage. Similar results can be expected, as confirmed by intestinal crypt cell experiments, with high-LET. Less interaction than with low-LET appears to occur with agents blocking sublethal damage repair or causing synchronization. (author)

Towards the Ethical or the Unethical Side?: An Explorative Research of Greek Business Students' Attitudes

Science.gov (United States)

Karassavidou, Eleonora; Glaveli, Niki

2006-01-01

Purpose: The purpose of this research is to investigate the ethical orientations of undergraduate business students in Greece by exploring the relations among students' internalized code of ethics, anomia and students' judgment related to ethical problem situations within classroom as well as business context. Design/methodology/approach: A…

Exploring the Self-Reported ICT Skill Levels of Undergraduate Science Students

Directory of Open Access Journals (Sweden)

Jef C. Verhoeven

2015-12-01

Full Text Available Computers have taken an important place in the training of science students and in the professional life of scientists. It is often taken for granted that most students have mastered basic Information and Communication Technologies (ICT skills; however, it has been shown that not all students are equally proficient in this regard. Starting from theories of socialization and technology acceptance we report how we constructed a structural equation model (SEM to explore the variance in the basic ICT skill levels of science students. We also present the results of a test of this model with university bachelor’s science students. Basic ICT skills were measured using a new, elaborate instrument allowing students to rate their skills in detail. Our results show that science students score high on basic ICT skills and that our SEM explains a large part of the variation in the ICT skill levels of these students. The most explanatory power is coming from four variables: the perceived ease of use and the perceived usefulness of a personal computer, the anxiety for using a personal computer, and students’ belief that ICT is necessary for scientific research.

Creating a Successful Academic Climate for Urban Students

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Slaughter, Terri

2009-01-01

Teaching students in the inner city has been likened to hugging a porcupine--teachers nudge them toward success while getting pricked along the way. Many urban students perform below proficiency level and are difficult to manage. Their apathy toward completing class assignments, let alone homework, compounds the problem. As a whole, educators do…

Mutagenic effect of radiations of various LET on Salmonella cells

International Nuclear Information System (INIS)

Kozubek, S.; Krasavin, E.A.; Amirtaev, K.G.; Tokarova, B.; Basha, S.G.

1989-01-01

Regularities of mutagenic effect of heavy charged particles of helium, deuterium ions and protons on various strains of Salmonella typhimurium were studied. Linear dose dependences of mutation frequency in the range of low doses were revealed. A conclusion was made that mutation process at low dose irradiation is determined in various teststrains of Salmonella typhimurium by certain premutation injuries. Quite a different picture is observed in mutation process in case of high dose irradiation where effect of inducible SOS-repair is distinctly manifested. Not only spectra of primary DNA injuries but probability of their fixation into mutation can change with the increase of LET. If fixation probability doesn't change with LET increase for replicative mutagenesis which make basis contribution to linear component of dose dependence of mutation frequency the probability of fixation is increased for reparative mutagenesis. It accounts for increase of values of relative genetic efficiency with LET increase. 7 refs.; 6 figs.; 1 tab

Exploring whether student nurses report poor practice they have witnessed on placements.

Science.gov (United States)

Bellefontaine, Nerys

While literature suggests that nurses report incidents or potentially unsafe care delivery, there is little evidence on student nurses' practice in this area. To explore the factors that influence student in reporting concerns about practice. A qualitative study was carried out using a phenomenological approach, based on semi-structured interviews with six student nurses. Student nurses said they do not always report potentially unsafe practice they have witnessed. Four main themes were identified: the student-mentor relationship in clinical placement; actual or potential support provided by both the practice area and university; students' own personal confidence and professional knowledge base; and fear of failing clinical placements. The nursing profession needs to take stock of current organisational culture and practice, and address issues around reporting in practice. Recommendations are made to improve mentorship, nurse training and for further research.

Letting go or holding on? Parents' perceptions of their relationships with their children during emerging adulthood.

Science.gov (United States)

Kloep, Marion; Hendry, Leo B

2010-11-01

This qualitative interview study explored and examined the transitions surrounding emerging adulthood within the family from the parents' perspective. Interviews conducted with a purposive sample of parents (N = 59) revealed the perceived difficulties parents have in 'letting go' of their grown-up children, and in acknowledging their developing autonomy; and demonstrated a range of perceived parental strategies in response to young people's growing independence. The significance of these intertwined elements of perceived dependency, emotional tensions, and interactive behaviours for relationships in the family, and the implications for 'emerging adulthood', was discussed.

Mechanism and significance of let-7 in diagnosis and treatment of hepatocellular carcinoma

Directory of Open Access Journals (Sweden)

HUO Tingting

2017-07-01

Full Text Available Abstract:MicroRNA (miRNA play important roles in post-transcriptional gene regulation. In recent years, miRNA has become a hot topic in the research on the development and progression of tumors, and gene targeting therapy for malignant tumors has achieved preliminary progress. As one of the first discovered miRNA, let-7 can regulate the cell cycle and angiogenesis and is involved in the proliferation, differentiation, and apoptosis of various tumor cells. Most members of the let-7 family can act as tumor suppressor gene and have low expression in various tumor tissues and high expression in the serum of patients with malignant tumors. Let-7 is closely associated with the invasion and drug resistance of hepatocellular carcinoma (HCC. The studies above show that let-7 might become a new marker for the early diagnosis of HCC and provide new targets for the treatment of HCC.

Privileged Pursuits of Social Justice: Exploring Privileged College Students' Motivation for Engaging in Social Justice

Science.gov (United States)

Howard, Adam

2011-01-01

The author of this article explores the motivation factors that lead privileged college students to be involved in social justice efforts. The students participating in this study identified multiple reasons for their initial and continued involvement in social justice work, but all students identified three main sources of motivation: responding…

An Exploration of Secondary Students' Mental States When Learning about Acids and Bases

Science.gov (United States)

Liu, Chia-Ju; Hou, I-Lin; Chiu, Houn-Lin; Treagust, David F.

2014-01-01

This study explored factors of students' mental states, including emotion, intention, internal mental representation, and external mental representation, which can affect their learning performance. In evaluating students' mental states during the science learning process and the relationship between mental states and learning…

Owning, letting and demanding second homes in Denmark

DEFF Research Database (Denmark)

Bloze, Gintautas; Skak, Morten

with administrative register data and presents estimations of the probability of owning a second home, the decision to let the second home and the number of let weeks per year. Also income elasticities for primary and second housing demand are estimated. We find a conventional monotonic increase in demand...... elasticities for primary housing demand for non-owners of second homes; however, owners of second homes have the highest income elasticity in the middle income group.......An increasing number of households consume housing beyond the primary home as owners of a second home. Economic studies of non-speculative demand for second homeownership are still scarce, and the present empirical study fills this gap to some extent. It is based on Danish survey data combined...

ExplorOcean H2O SOS: Help Heal the Ocean-Student Operated Solutions: Operation Climate Change

Science.gov (United States)

Weiss, N.; Wood, J. H.

2016-12-01

The ExplorOcean H2O SOS: Help Heal the Ocean—Student Operated Solutions: Operation Climate Change, teaches middle and high school students about ocean threats related to climate change through hands-on activities and learning experiences in the field. During each session (in-class or after-school as a club), students build an understanding about how climate change impacts our oceans using resources provided by ExplorOcean (hands-on activities, presentations, multi-media). Through a student leadership model, students present lessons to each other, interweaving a deep learning of science, 21st century technology, communication skills, and leadership. After participating in learning experiences and activities related to 6 key climate change concepts: 1) Introduction to climate change, 2) Increased sea temperatures, 3) Ocean acidification, 4) Sea level rise, 5) Feedback mechanisms, and 6) Innovative solutions. H2O SOS- Operation Climate change participants select one focus issue and use it to design a multi-pronged campaign to increase awareness about this issue in their local community. The campaign includes social media, an interactive activity, and a visual component. All participating clubs that meet participation and action goals earn a field trip to ExplorOcean where they dive deeper into their selected issue through hands-on activities, real-world investigations, and interviews or presentations with experts. In addition to self-selected opportunities to showcase their focus issue, teams will participate in one of several key events identified by ExplorOcean, including ExplorOcean's annual World Oceans Day Expo.

Exploring Science Through Polar Exploration

Science.gov (United States)

Pfirman, S. L.; Bell, R. E.; Zadoff, L.; Kelsey, R.

2003-12-01

Exploring the Poles is a First Year Seminar course taught at Barnard College, Columbia University. First Year Seminars are required of incoming students and are designed to encourage critical analysis in a small class setting with focused discussion. The class links historical polar exploration with current research in order to: introduce non-scientists to the value of environmental science through polar literature; discuss issues related to venturing into the unknown that are of relevance to any discipline: self-reliance, leadership, preparation, decisions under uncertainty; show students the human face of science; change attitudes about science and scientists; use data to engage students in exploring/understanding the environment and help them learn to draw conclusions from data; integrate research and education. These goals are met by bringing analysis of early exploration efforts together with a modern understanding of the polar environment. To date to class has followed the efforts of Nansen in the Fram, Scott and Amundsen in their race to the pole, and Shackleton's Endurance. As students read turn-of-the-century expedition journals, expedition progress is progressively revealed on an interactive map showing the environmental context. To bring the exploration process to life, students are assigned to expedition teams for specific years and the fates of the student "expeditions" are based on their own decisions. For example, in the Arctic, they navigate coastal sea ice and become frozen into the ice north of Siberia, re-creating Nansen's polar drift. Fates of the teams varied tremendously: some safely emerged at Fram Strait in 4 years, while others nearly became hopelessly lost in the Beaufort Gyre. Students thus learn about variability in the current polar environment through first hand experience, enabling them to appreciate the experiences, decisions, and, in some cases, the luck, of polar explorers. Evaluation by the Columbia Center for New Media, Teaching

"Borrowing Happiness from the Future": Exploring College Students' Own Experiences on Health-Related Lifestyles

Science.gov (United States)

Chen, Hsin-Yu; Yarnal, Careen; Bram, Barry

2017-01-01

Combining the theory of emerging adulthood with self-authorship, the authors utilized students' reflection papers (n = 111) to explore their current lifestyles and reasons behind behavioral changes. Decreased physical activity, increased substance use, irregular sleep patterns, and unhealthy dietary habits emerged after students transitioned to…

Suppression of MicroRNA let-7a Expression by Agmatine Regulates Neural Stem Cell Differentiation.

Science.gov (United States)

Song, Juhyun; Oh, Yumi; Kim, Jong Youl; Cho, Kyoung Joo; Lee, Jong Eun

2016-11-01

Neural stem cells (NSCs) effectively reverse some severe central nervous system (CNS) disorders, due to their ability to differentiate into neurons. Agmatine, a biogenic amine, has cellular protective effects and contributes to cellular proliferation and differentiation in the CNS. Recent studies have elucidated the function of microRNA let-7a (let-7a) as a regulator of cell differentiation with roles in regulating genes associated with CNS neurogenesis. This study aimed to investigate whether agmatine modulates the expression of crucial regulators of NSC differentiation including DCX, TLX, c-Myc, and ERK by controlling let-7a expression. Our data suggest that high levels of let-7a promoted the expression of TLX and c-Myc, as well as repressed DCX and ERK expression. In addition, agmatine attenuated expression of TLX and increased expression of ERK by negatively regulating let-7a. Our study therefore enhances the present understanding of the therapeutic potential of NSCs in CNS disorders.

Generating Code with Polymorphic let: A Ballad of Value Restriction, Copying and Sharing

Directory of Open Access Journals (Sweden)

Oleg Kiselyov

2017-02-01

Full Text Available Getting polymorphism and effects such as mutation to live together in the same language is a tale worth telling, under the recurring refrain of copying vs. sharing. We add new stanzas to the tale, about the ordeal to generate code with polymorphism and effects, and be sure it type-checks. Generating well-typed-by-construction polymorphic let-expressions is impossible in the Hindley-Milner type system: even the author believed that. The polymorphic-let generator turns out to exist. We present its derivation and the application for the lightweight implementation of quotation via a novel and unexpectedly simple source-to-source transformation to code-generating combinators. However, generating let-expressions with polymorphic functions demands more than even the relaxed value restriction can deliver. We need a new deal for let-polymorphism in ML. We conjecture the weaker restriction and implement it in a practically-useful code-generation library. Its formal justification is formulated as the research program.

Let-7i-Induced Atg4B Suppression Is Essential for Autophagy of Placental Trophoblast in Preeclampsia.

Science.gov (United States)

Xu, Yinyan; Huang, Xinyan; Xie, Juan; Chen, Yanni; Fu, Jing; Wang, Li

2017-09-01

Autophagy, identified as type II programmed cell death, has already been known to be involved in the pathophysiology of preeclampsia (PE), which is a gestational disease with high morbidity. The present study aims to investigate the functional role of let-7i, a miRNA, in trophoblastic autophagy. Placental tissue used in this study was collected from patients with severe preeclampsia (SPE) or normal pregnant women. A decreased level of let-7i was found in placenta of SPE. In addition, autophagic vacuoles were observed in SPE and the expression of microtubule associated protein 1 light chain 3 (LC3) II/I was elevated. In vitro, let-7i mimics suppressed the autophagic activities in human HTR-8/SVneo trophoblast cell line (HTR-8) and human placental choriocarcinoma cell line JEG-3, whereas let-7i inhibitor enhanced the activities. As a potential target of let-7i, autophagy-related 4B cysteine peptidase (Atg4B) had an increased expression level in SPE. As expected, the increased expression of Atg4B was negatively regulated by let-7i using dual luciferase reporter assay. Furthermore, these trophoblast-like cells transfected with the let-7i mimic or inhibitors resulted in a significant change of Atg4B in both mRNA and protein level. More importantly, Atg4B overexpression could partly reverse let-7i mimic-reduced LC3II/I levels; whereas Atg4B silencing partly attenuated let-7i inhibitor-induced the level of LC3II/I expression. Taken together, these findings suggest that let-7i is able to regulate autophagic activity via regulating Atg4B expression, which might contribute to the pathogenesis of PE. J. Cell. Physiol. 232: 2581-2589, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Students as Virtual Scientists: An exploration of students' and teachers' perceived realness of a remote electron microscopy investigation

Science.gov (United States)

Childers, Gina; Jones, M. Gail

2015-10-01

Remote access technologies enable students to investigate science by utilizing scientific tools and communicating in real-time with scientists and researchers with only a computer and an Internet connection. Very little is known about student perceptions of how real remote investigations are and how immersed the students are in the experience. This study, conducted with high school students and their teachers, explored the impact of students' perception of ownership and virtual presence during a remote investigation using a scanning electron microscope. Students were randomly assigned to one of two treatment groups: students able to select their own insect to use during the remote investigation, and students that did not select their own insects to view during the remote investigation. The results of this study showed that students in the experimental group who had choice and ownership of their insect reported being more present (less distracted) during the remote investigation than students in the control group, whereas students in the control group reported controlling the technology was easier than the experimental group. Students indicated the remote investigation was very real; however, the teachers of these students were less likely to describe the investigation as being real. The results of this study have practical implications for designing remote learning environments.

High LET Radiation Amplifies Centrosome Overduplication Through a Pathway of γ-Tubulin Monoubiquitination

Energy Technology Data Exchange (ETDEWEB)

Shimada, Mikio [Department of Genome Repair Dynamics, Radiation Biology Center, Kyoto University, Kyoto (Japan); Hirayama, Ryoichi [Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba (Japan); Komatsu, Kenshi, E-mail: komatsu@house.rbc.kyoto-u.ac.jp [Department of Genome Repair Dynamics, Radiation Biology Center, Kyoto University, Kyoto (Japan)

2013-06-01

Purpose: Radiation induces centrosome overduplication, leading to mitotic catastrophe and tumorigenesis. Because mitotic catastrophe is one of the major tumor cell killing factors in high linear energy transfer (LET) radiation therapy and long-term survivors from such treatment have a potential risk of secondary tumors, we investigated LET dependence of radiation-induced centrosome overduplication and the underlying mechanism. Methods and Materials: Carbon and iron ion beams (13-200 keV/μm) and γ-rays (0.5 keV/μm) were used as radiation sources. To count centrosomes after IR exposure, human U2OS and mouse NIH3T3 cells were immunostained with antibodies of γ-tubulin and centrin 2. Similarly, Nbs1-, Brca1-, Ku70-, and DNA-PKcs-deficient mouse cells and their counterpart wild-type cells were used for measurement of centrosome overduplication. Results: The number of excess centrosome-containing cells at interphase and the resulting multipolar spindle at mitosis were amplified with increased LET, reaching a maximum level of 100 keV/μm, followed by sharp decrease in frequency. Interestingly, Ku70 and DNA-PKcs deficiencies marginally affected the induction of centrosome overduplication, whereas the cell killings were significantly enhanced. This was in contrast to observation that high LET radiation significantly enhanced frequencies of centrosome overduplication in Nbs1- and Brca1-deficient cells. Because NBS1/BRCA1 is implicated in monoubiquitination of γ-tubulin, we subsequently tested whether it is affected by high LET radiation. As a result, monoubiquitination of γ-tubulin was abolished in 48 to 72 hours after exposure to high LET radiation, although γ-ray exposure slightly decreased it 48 hours postirradiation and was restored to a normal level at 72 hours. Conclusions: High LET radiation significantly reduces NBS1/BRCA1-mediated monoubiquitination of γ-tubulin and amplifies centrosome overduplication with a peak at 100 keV/μm. In contrast, Ku70 and DNA

Exploring Student Self-Plagiarism

Science.gov (United States)

Halupa, Colleen M.

2014-01-01

Student self-plagiarism is a confusing issue for both faculty and students alike. This problem is compounded because both groups perceive the concept very differently. Recent literature regarding these perceptions is reviewed and some brief preliminary results of an exploratory multi-university study of student perceptions of self-plagiarism are…

Effects of let-7b and TLX on the proliferation and differentiation of retinal progenitor cells in vitro.

Science.gov (United States)

Ni, Ni; Zhang, Dandan; Xie, Qing; Chen, Junzhao; Wang, Zi; Deng, Yuan; Wen, Xuyang; Zhu, Mengyu; Ji, Jing; Fan, Xianqun; Luo, Min; Gu, Ping

2014-10-20

MicroRNAs manifest significant functions in brain neural stem cell (NSC) self-renewal and differentiation through the post-transcriptional regulation of neurogenesis genes. Let-7b is expressed in the mammalian brain and regulates NSC proliferation and differentiation by targeting the nuclear receptor TLX, which is an essential regulator of NSC self-renewal. Whether let-7b and TLX act as important regulators in retinal progenitor cell (RPC) proliferation and differentiation remains unknown. Here, our data show that let-7b and TLX play important roles in controlling RPC fate determination in vitro. Let-7b suppresses TLX expression to negatively regulate RPC proliferation and accelerate the neuronal and glial differentiation of RPCs. The overexpression of let-7b downregulates TLX levels in RPCs, leading to reduced RPC proliferation and increased neuronal and glial differentiation, whereas antisense knockdown of let-7b produces robust TLX expression,enhanced RPC proliferation and decreased differentiation. Moreover, the inhibition of endogenous TLX by small interfering RNA suppresses RPC proliferation and promotes RPC differentiation. Furthermore, overexpression of TLX rescues let-7b-induced proliferation deficiency and weakens the RPC differentiation enhancement caused by let-7b alone. These results suggest that let-7b, by forming a negative feedback loop with TLX, provides a novel model to regulate the proliferation and differentiation of retinal progenitors in vitro.

Exploring a Relational Cultural Group Trainee Model for Master's Level Counseling Students

Science.gov (United States)

Hall, Brenda S.; Harper, Irene; Korcuska, James

2018-01-01

We explored students' experiences of a graduate level group course infused with components of the Relational Cultural Theory (RCT). During the didactic and experiential aspects of 2 semester-long group courses, the faculty instructors and students focused on creating an environment of safety, connection, and empowerment. The instructor and…

Review of relative biological effectiveness dependence on linear energy transfer for low-LET radiations

International Nuclear Information System (INIS)

Hunter, Nezahat; Muirhead, Colin R

2009-01-01

Information on Japanese A-bomb survivors exposed to gamma radiation has been used to estimate cancer risks for the whole range of photon (x-rays) and electron energies which are commonly encountered by radiation workers in the work place or by patients and workers in diagnostic radiology. However, there is some uncertainty regarding the radiation effectiveness of various low-linear energy transfer (low-LET) radiations (x-rays, gamma radiation and electrons). In this paper we review information on the effectiveness of low-LET radiations on the basis of epidemiological and in vitro radiobiological studies. Data from various experimental studies for chromosome aberrations and cell transformation in human lymphocytes and from epidemiological studies of the Japanese A-bomb survivors, patients medically exposed to radiation for diagnostic and therapeutic procedures, and occupational exposures of nuclear workers are considered. On the basis of in vitro cellular radiobiology, there is considerable evidence that the relative biological effectiveness (RBE) of high-energy low-LET radiation (gamma radiation, electrons) is less than that of low-energy low-LET radiation (x-rays, betas). This is a factor of about 3 to 4 for 29 kVp x-rays (e.g. as in diagnostic radiation exposures of the female breast) and for tritium beta-rays (encountered in parts of the nuclear industry) relative to Co-60 gamma radiation and 2-5 MeV gamma-rays (as received by the Japanese A-bomb survivors). In epidemiological studies, although for thyroid and breast cancer there appears to be a small tendency for the excess relative risks to decrease as the radiation energy increases for low-LET radiations, it is not statistically feasible to draw any conclusion regarding an underlying dependence of cancer risk on LET for the nominally low-LET radiations. (review)

High LET radiation enhances apoptosis in mutated p53 cancer cells through Caspase-9 activation

International Nuclear Information System (INIS)

Yamakawa, Nobuhiro; Takahashi, Akihisa; Mori, Eiichiro; Imai, Yuichiro; Ohnishi, Ken; Kirita, Tadaaki; Ohnishi, Takeo; Furusawa, Yoshiya

2008-01-01

Although mutations in the p53 gene can lead to resistance to radiotherapy, chemotherapy and thermotherapy, high linear energy transfer (LET) radiation induces apoptosis regardless of p53 gene status in cancer cells. The aim of this study was to clarify the mechanisms involved in high LET radiation-induced apoptosis. Human gingival cancer cells (Ca9-22 cells) containing a mutated p53 (mp53) gene were irradiated with X-rays, C-ion (13-100 KeV/μm), or Fe-ion beams (200 KeV/μm). Cellular sensitivities were determined using colony forming assays. Apoptosis was detected and quantified with Hoechst 33342 staining. The activity of Caspase-3 was analyzed with Western blotting and flow cytometry. Cells irradiated with high LET radiation showed a high sensitivity with a high frequency of apoptosis induction. The relative biological effectiveness (RBE) values for the surviving fraction and apoptosis induction increased in a LET-dependent manner. Both RBE curves reached a peak at 100 KeV/μm, and then decreased at values over 100 KeV/μm. When cells were irradiated with high LET radiation, Caspase-3 was cleaved and activated, leading to poly (ADP-ribose) polymerase (PARP) cleavage. In addition, Caspase-9 inhibitor suppressed Caspase-3 activation and apoptosis induction resulting from high LET radiation to a greater extent than Caspase-8 inhibitor. These results suggest that high LET radiation enhances apoptosis by activation of Caspase-3 through Caspase-9, even in the presence of mp53. (author)

The Impact of Career Exploration on Career Development among Hong Kong Chinese University Students

Science.gov (United States)

Cheung, Raysen; Arnold, John

2014-01-01

Career exploration is widely believed to produce positive career development outcomes among college and university students. Some research has supported this belief, but there is little information about exactly which outcomes it affects and whether any benefits of career exploration can be observed beyond individualistic western cultures. We…

Exploring Students' Perceptions of Service-Learning Experiences in an Undergraduate Web Design Course

Science.gov (United States)

Lee, Sang Joon; Wilder, Charlie; Yu, Chien

2018-01-01

Service-learning is an experiential learning experience where students learn and develop through active participation in community service to meet the needs of a community. This study explored student learning experiences in a service-learning group project and their perceptions of service-learning in an undergraduate web design course. The data…

An Exploration into the Impact of Blogs on Students' Learning: Case Studies in Postgraduate Business Education

Science.gov (United States)

Mansouri, S. Afshin; Piki, Andriani

2016-01-01

The research draws from four case studies to investigate the impact of using blogs within postgraduate education. The study explores how postgraduate business students engage with blogs, whether students' learning preferences correlate with their degree of contribution and how student participation relates with overall achievement. A mixed…

The efficacy of video monitoring-supported student self-evaluation of dental explorer skills in dental hygiene education.

Science.gov (United States)

Tano, R; Takaku, S; Ozaki, T

2017-11-01

The objective of this study was to investigate whether having dental hygiene students monitor video recordings of their dental explorer skills is an effective means of proper self-evaluation in dental hygiene education. The study participants comprised students of a dental hygiene training school who had completed a module on explorer skills using models, and a dental hygiene instructor who was in charge of lessons. Questions regarding 'posture', 'grip', 'finger rest' and 'operation' were set to evaluate explorer skills. Participants rated each item on a two-point scale: 'competent (1)' or 'not competent (0)'. The total score was calculated for each evaluation item in evaluations by students with and without video monitoring, and in evaluations by the instructor with video monitoring. Mean scores for students with and without video monitoring were compared using a t-test, while intraclass correlation coefficients were found by reliability analysis of student and instructor evaluations. A total of 37 students and one instructor were subject to analysis. The mean score for evaluations with and without video monitoring differed significantly for posture (P Dental Hygiene Published by John Wiley& Sons Ltd.

An Exploration Of Engagement, Motiviation And Student-Centered Learning In Physical Education

Directory of Open Access Journals (Sweden)

Barbara WARNER

2015-12-01

Full Text Available This author examines the discrepancy between the known benefits of physical activity and the startling statistics of obesity in children between the ages of 12 and 17. She queries if it is time to look at educators as contributing to this problem and questions if our current teaching styles and curriculum are working for students. In addition, the author explores the question if by allowing our students autonomy, will this equate to engagement and motivation to continue to participate in physical activities? Through a discussion of her personal experiences and a literature review focusing on the areas of autonomy, engagement and motivation, the author shares input into how and why some students experience physical education in a negative manner, and some things that educators can do to improve student engagement and motivation. Her argument demonstrates that an autonomous, student-centered teaching approach will positively affect student engagement, which in turn causes motivation and a desire to participate in life-long physical activity.

LET spectrum measurements in Cr-39 PNTD with AFM

Energy Technology Data Exchange (ETDEWEB)

Johnson, Carl Edward [Los Alamos National Laboratory; De Witt, Joel M [OSU, PHYSICS; Benton, Eric R [OSU, PHYSICS; Yasuda, Nakahiro [NIRS, HIMAC; Benton, Eugene V [UNIV OF SAN FRANCISCO

2010-01-01

Energetic protons, neutrons, and heavy ions undergoing collisions with target nuclei of varying Z can produce residual heavy recoil fragments via intra-nuclear cascade/evaporation reactions. The particles produced in these non-elastic collisions generally have such extremely short range ({approx}< 10 {mu}m) that they cannot be directly observed by conventional detection methods including CR-39 plastic nuclear track detector (PNTD) that has been chemically etched for analysis by standard visible light microscopy. However, high-LET recoil fragments having range on the order of several cell diameters can be produced in tissue during radiotherapy using proton and carbon beams. We have developed a method to analyze short-range, high-LET tracks in CR-39 plastic nuclear track detector (PNTD) using short duration chemical etching ({approx}< 1 {mu}m) followed by automated atomic force microscope (AFM) scanning. The post-scan data processing used in this work was based on semi-automated matrix analysis opposed to traditional grey-scale image analysis. This method takes advantage of the 3-D data obtained via AFM to achieve robust discrimination of nuclear tracks from other features. Through automation of AFM scanning, sufficient AFM scan frames were obtained to attain an LET spectrum spanning the LET range from 200-1500 keV/{mu}m. In addition to our experiments, simulations were carried out with the Monte Carlo transport code, FLUKA. To demonstrate this method, CR-39 PNTD was exposed to the proton therapy beam at Loma Linda University Medical Center (LLUMC) at 60 and 230 MeV. Additionally, detectors were exposed to I GeV protons at the NASA Space Radiation Laboratory (NSRL) at Brookhaven National Laboratory (BNL). For these exposures CR-39 PNTD, Al and Cu target foils were used between detector layers.

LET spectrum measurements in Cr-39 PNTD with AFM

International Nuclear Information System (INIS)

Johnson, Carl Edward; DeWitt, Joel M.; Benton, Eric R.; Yasuda, Nakahiro; Benton, Eugene V.

2010-01-01

Energetic protons, neutrons, and heavy ions undergoing collisions with target nuclei of varying Z can produce residual heavy recoil fragments via intra-nuclear cascade/evaporation reactions. The particles produced in these non-elastic collisions generally have such extremely short range (∼< 10 μm) that they cannot be directly observed by conventional detection methods including CR-39 plastic nuclear track detector (PNTD) that has been chemically etched for analysis by standard visible light microscopy. However, high-LET recoil fragments having range on the order of several cell diameters can be produced in tissue during radiotherapy using proton and carbon beams. We have developed a method to analyze short-range, high-LET tracks in CR-39 plastic nuclear track detector (PNTD) using short duration chemical etching (∼< 1 μm) followed by automated atomic force microscope (AFM) scanning. The post-scan data processing used in this work was based on semi-automated matrix analysis opposed to traditional grey-scale image analysis. This method takes advantage of the 3-D data obtained via AFM to achieve robust discrimination of nuclear tracks from other features. Through automation of AFM scanning, sufficient AFM scan frames were obtained to attain an LET spectrum spanning the LET range from 200-1500 keV/μm. In addition to our experiments, simulations were carried out with the Monte Carlo transport code, FLUKA. To demonstrate this method, CR-39 PNTD was exposed to the proton therapy beam at Loma Linda University Medical Center (LLUMC) at 60 and 230 MeV. Additionally, detectors were exposed to I GeV protons at the NASA Space Radiation Laboratory (NSRL) at Brookhaven National Laboratory (BNL). For these exposures CR-39 PNTD, Al and Cu target foils were used between detector layers.

WE-H-BRA-05: Investigation of LET Spectral Dependence of the Biological Effects of Therapeutic Protons

Energy Technology Data Exchange (ETDEWEB)

Guan, F; Bronk, L; Kerr, M; Wang, X; Li, Y; Peeler, C; Sahoo, N; Patel, D; Mirkovic, D; Titt, U; Grosshans, D; Mohan, R [UT MD Anderson Cancer Center, Houston, TX (United States)

2016-06-15

Purpose: To investigate the dependence of biologic effect (BE) of therapeutic protons on LET spectra by comparing BEs with equal dose-averaged LET (LETd) derived from different LET spectra using high-throughput in vitro clonogenic survival assays. Methods: We used Geant4 to design the relevant experimental setups and perform the dose, LETd, and LET spectra calculations for spot-scanning protons. The clonogenic assay was performed using the H460 lung cancer cell line cultured in 96-well plates. In the first experimental setup (S1), cells were irradiated using 127.4 MeV protons with a 93.22 mm Lucite buildup resulting in a LETd value of 3.4 keV/µm in the cell layer. In the second experimental setup (S2), cells were irradiated by a combination of 127.4 MeV and 136.4 MeV protons with a 96.61 mm Lucite buildup. The LETd values in the cell layer were 11.4 keV/µm and 1.5 keV/µm respectively, but an average LETd of 3.4 keV/µm was obtained by adjusting the relative fluence of each beam. Ten discrete dose levels with 0.5 Gy increments were delivered. Results: In the two setups, the energies or LET spectra were different but resulted in identical LETd values. We quantified the dose contributions from high-LET (≥10 keV/µm, threshold determined by previous experiments) events in the LET spectra separately for these two setups as 3.2% and 10.5%. The biologic effects at each identical dose level yielded statistically significant different survival curves (extra sum-of-squares F-test, P<0.0001). The second setup with a higher contribution from high-LET events exhibited the higher biologic effect with a dose enhancement factor of 1.17±0.03 at 0.10 surviving fraction. Conclusion: The dose-averaged LET may not be an accurate indicator of the biological effects of protons. Detailed LET spectra may need to be considered explicitly to accurately quantify the biologic effects of protons. Funding Support: U19 CA021239-35, R21 CA187484-01 and MDACC-IRG.

Let the Right One In : Motion picture (2008)

OpenAIRE

Buhagiar, Celaine; Lauri Lucente, Gloria

2009-01-01

Twilight: A teenage girl risks everything when she falls in love with a vampire. Let the Right One In: Oskar, an overlooked and bullied boy, finds love and revenge through Eli, a beautiful but peculiar girl.

Cosmic ray LET spectra and doses on board Cosmos-2044 biosatellite

International Nuclear Information System (INIS)

Dudkin, V.E.; Kovalev, E.E.; Potapov, Yu.V.

1992-01-01

Results of the experiments on board Cosmos-2044 (Biosatellite 9) are presented. Various nuclear track detectors (NTD) (dielectric, AgCl-based, nuclear emulsions) were used to obtain the LET spectra inside and outside the satellite. The spectra from the different NTDs have proved to be in general agreement. The results of LET spectra calculations using two different models are also presented. The resultant LET distributions are used to calculate the absorbed and equivalent doses and the orbit-averaged quality factors (QF) of the cosmic rays (CR). Absorbed dose rates inside (∼ 20 g cm -2 shielding) and outside (1 g cm -2 ) the spacecraft, omitting electrons, were found to be 4.8 and 8.6 mrad d -1 , respectively, while the corresponding equivalent doses were 8.8 and 19.7 mrem d -1 . The effects of the flight parameters on the total fluence of, and on the dose from, the CR particles are analyzed. Integral dose distributions of the detected particles are also determined. The LET values which separate absorbed and equivalent doses into 50% intervals are estimated. The CR-39 dielectric NTD is shown to detect 20-30% of the absorbed dose and 60-70% of the equivalent dose in the Cosmos-2044 orbit. The influence of solar activity phase on the magnitude of the CR flux is discussed. (author)

What Makes a "Good Group"? Exploring the Characteristics and Performance of Undergraduate Student Groups

Science.gov (United States)

Channon, S. B.; Davis, R. C.; Goode, N. T.; May, S. A.

2017-01-01

Group work forms the foundation for much of student learning within higher education, and has many educational, social and professional benefits. This study aimed to explore the determinants of success or failure for undergraduate student teams and to define a "good group" through considering three aspects of group success: the task, the…

Measuring Teacher Effectiveness through Hierarchical Linear Models: Exploring Predictors of Student Achievement and Truancy

Science.gov (United States)

Subedi, Bidya Raj; Reese, Nancy; Powell, Randy

2015-01-01

This study explored significant predictors of student's Grade Point Average (GPA) and truancy (days absent), and also determined teacher effectiveness based on proportion of variance explained at teacher level model. We employed a two-level hierarchical linear model (HLM) with student and teacher data at level-1 and level-2 models, respectively.…

Mathematics Education for Engineering Technology Students – A Bridge Too Far?

Directory of Open Access Journals (Sweden)

Noraishiyah Abdullah

2013-03-01

Full Text Available Trying to decide what is best suited for someone or something is an ever enduring task let alone trying to prepare students with the right engineering mind. So ‘how do you build an engineer?’ if that is the right word. What is the right ingredient? Mathematics has been said as the most important foundation in engineers’ life. Curriculum has been developed and reviewed over the years to meet this target. This work explores how much or lack of it has the curriculum prepares the future technologist to face the world of engineering technology as far as mathematics is concerned. Analysis of mathematics lectures, interviews of engineering technologist students and engineering technology subject lecturer is undertaken. Understand what each contributes help in understanding the picture that the current education is painting. Based on the theory of learning, APOS theory helps in explaining how students bridge their knowledge of mathematics when it comes to solving engineering technology problems. The question is, is it a bridge too far? 

Dosimetry and microdosimetry using LET spectrometer based on the track-etch detector: radiotherapy Bremsstrahlung beam, onboard aircraft radiation field

International Nuclear Information System (INIS)

Jadrnickova, I.; Spurny, F.

2006-01-01

The spectrometer of linear energy transfer (Let) based on the chemically etched poly-allyl-diglycol-carbonate (P.A.D.C.) track-etch detector was developed several years ago in our institute. This Let spectrometer enables determining Let of particles approximately from 10 to 700 keV/μm. From the Let spectra, dose characteristics can be calculated. The contribution presents the Let spectra and other dosimetric characteristics obtained onboard a commercial aircraft during more than 6 months long exposure and in the 18 MV radiotherapy Bremsstrahlung beam. (authors)

High-LET particle dosimetry in the ASTP-Biostack III: Zea mays experiment

International Nuclear Information System (INIS)

Peterson, D.D.; Benton, E.V.; Tran, M.; Yang, T.; Freeling, M.; Craise, L.; Tobias, C.A.

1977-01-01

High-LET particle hits in embryos of Zea mays (corn) seeds, flown as part of the ASTP-Biostack III, were determined via plastic nuclear track detectors. Based on etched particle-tracks measurements, 41 embryos were hit in seed layer 1 which contained 80 seeds, and 49 hits occurred in layer 2 which contained 79 seeds. The mean LET value and range of atomic numbers of recorded hits is, respectively, 210 +- 57 keV/μm and 9 approximately less than Z approximately less than 26. Detailed analysis of one particular seed showing marked growth anomalies revealed two hits in the central region of the embryo. These two hits had LET values in the region of 100 to 150 keV/μm, and Z less than approximately 20. (author)

Chemical protection from high LET radiation

International Nuclear Information System (INIS)

Ando, Koichi; Koike, Sachiko; Matsushita, Satoru; Kanai, Tatsuaki; Ohara, Hiroshi

1992-01-01

Radioprotection by WR151327 from high LET fast neutrons was investigated and compared with that from low LET radiation. Radiation damage in bone marrow, intestine, skin and leg length were all protected by a pretreatment with 400 mg/kg WR151327. Most prominent protection was observed for bone marrow, which gave a Dose Modifying Factor (DMF) of 2.2 against γ rays. Identical protection was observed between early and late radiation damage. WR151327 protected fast neutrons less efficiently than γ rays; 40% for bone marrow and 80% for skin leg. Pathological findings indicated that hyperplastic change in both dermis and epidermis associated with late skin shrinkage. Laser doppler flow-metry showed a good relationship between reduction of blood flow and late skin shrinkage. Irradiation of skin by heavy particle Carbon-12 indicated that skin shrinkage was modified by unirradiated surrounding normal tissues, which proposed a significant role of 'Volume Effect' in radiation damage. Tumor tissues were less protected by WR151327 than normal tissues. Dependence of radioprotection by WR151327 on tissue oxygen concentration is a probable reason to explain the difference between normal and tumor tissues. (author)

Let-7a is a direct EWS-FLI-1 target implicated in Ewing's sarcoma development.

Directory of Open Access Journals (Sweden)

Claudio De Vito

Full Text Available Ewing's sarcoma family tumors (ESFT are the second most common bone malignancy in children and young adults, characterized by unique chromosomal translocations that in 85% of cases lead to expression of the EWS-FLI-1 fusion protein. EWS-FLI-1 functions as an aberrant transcription factor that can both induce and suppress members of its target gene repertoire. We have recently demonstrated that EWS-FLI-1 can alter microRNA (miRNA expression and that miRNA145 is a direct EWS-FLI-1 target whose suppression is implicated in ESFT development. Here, we use miRNA arrays to compare the global miRNA expression profile of human mesenchymal stem cells (MSC and ESFT cell lines, and show that ESFT display a distinct miRNA signature that includes induction of the oncogenic miRNA 17-92 cluster and repression of the tumor suppressor let-7 family. We demonstrate that direct repression of let-7a by EWS-FLI-1 participates in the tumorigenic potential of ESFT cells in vivo. The mechanism whereby let-7a expression regulates ESFT growth is shown to be mediated by its target gene HMGA2, as let-7a overexpression and HMGA2 repression both block ESFT cell tumorigenicity. Consistent with these observations, systemic delivery of synthetic let-7a into ESFT-bearing mice restored its expression in tumor cells, decreased HMGA2 expression levels and resulted in ESFT growth inhibition in vivo. Our observations provide evidence that deregulation of let-7a target gene expression participates in ESFT development and identify let-7a as promising new therapeutic target for one of the most aggressive pediatric malignancies.

Exploring the Writing Process of Indonesian EFL Students: The Effectiveness of Think-Aloud Protocol

Science.gov (United States)

Abas, Imelda Hermilinda; Aziz, Noor Hashima Abd

2016-01-01

The objectives of this study were to explore the writing process of the Indonesian English as a Foreign Language (EFL) students and to find out the effectiveness of using think-aloud protocol to understand the writing process. The data were obtained from six proficient EFL students who were doing Postgraduate English Language Studies Program in…

Exploring Individual Factors Affecting Business Students' Willingness to Study Abroad: A Case Study from the Caribbean

Science.gov (United States)

Hernández-Díaz, Arleen; Fernández-Morales, Leticia M.; Vega-Vilca, José C.; Córdova-Claudio, Mario

2016-01-01

Despite a low rate of student participation in study abroad programs in the Caribbean, there is insufficient research about the individual factors that help determine business students' willingness to study or to participate in internship programs abroad. This study aims to explore business students' attitudes toward study abroad. The positive…

A Course Exploration: Guiding Instruction to Prepare Students as Change Agents in Educational Reform

Directory of Open Access Journals (Sweden)

Kathy L. Church, EdD

2010-08-01

Full Text Available This article explores the premise of teacher identity development through course experiences directed at inquiry and social awareness. The course exploration examines the use of various strategies used to help promote educators as change agents. Pre-service students enrolled in a one-year master’s program with teaching credential participated in a yearlong course designed to engage them in guided inquiry while making connections between theory and practice. Evaluation of the projects and student perceptions of their work suggest that guided inquiry into educational issues builds critical thinking skills and a sense of purpose, leadership, and service through shaping teacher identity.

Mouse fecal microbiome after exposure to high LET radiation

Data.gov (United States)

National Aeronautics and Space Administration — Space travel is associated with continuous low-dose-rate exposure to high Linear Energy Transfer (LET) radiation. Pathophysiological manifestations after low-dose...

Exploring hurdles to transfer : student experiences of applying knowledge across disciplines

Science.gov (United States)

Lappalainen, Jouni; Rosqvist, Juho

2015-04-01

This paper explores the ways students perceive the transfer of learned knowledge to new situations - often a surprisingly difficult prospect. The novel aspect compared to the traditional transfer studies is that the learning phase is not a part of the experiment itself. The intention was only to activate acquired knowledge relevant to the transfer target using a short primer immediately prior to the situation where the knowledge was to be applied. Eight volunteer students from either mathematics or computer science curricula were given a task of designing an adder circuit using logic gates: a new context in which to apply knowledge of binary arithmetic and Boolean algebra. The results of a phenomenographic classification of the views presented by the students in their post-experiment interviews are reported. The degree to which the students were conscious of the acquired knowledge they employed and how they applied it in a new context emerged as the differentiating factors.

Exploring Chinese Students' Experience of Curriculum Internationalisation: A Comparative Study of Scotland and Australia

Science.gov (United States)

Cheng, Ming; Adekola, Olalekan Adeban; Shah, Mahsood; Valyrakis, Manousos

2018-01-01

Increasing enrolment of Chinese students has become a key feature of internationalisation for Western universities, but there is limited research into how curriculum internationalisation affects Chinese students' learning experiences. Using the typologies of curriculum internationalisation as a framework, this paper explores and compares how…

Oxygen as a product of water radiolysis in high-LET tracks. II. Radiobiological implications

International Nuclear Information System (INIS)

Baverstock, K.F.; Burns, W.G.

1981-01-01

Consideration is given to the possibility that molecular oxygen generated in the tracks of energetic heavy ions is responsible for the reduction in oxygen enhancement ratio (OER) with increasing linear energy transfer (LET) observed for the loss of reproductive capacity caused by radiation in many cellular organisms. Yields of oxygen relationship of OER to LET for two organisms, Chlamydomonas reinhardii and Shigella flexneri, using a simple diffusion kinetic model for radiobiological action which takes account of the diffusion of oxygen after its formation. The results of these calculations show that the model accounts well for the shape of the OER vs. LET relationship

Exploring Students' Perceptions about English Learning in a Public University

Science.gov (United States)

Jiménez, Patricia Kim

2018-01-01

This manuscript reports the final findings of an exploratory, descriptive case study that aimed at exploring the perceptions of a group of English as a foreign language students in a public university regarding their English learning and the commitment level through the process. A questionnaire, a survey, and the teacher's diary were the…

Interactions among Future Study Abroad Students: Exploring Potential Intercultural Learning Sequences

Science.gov (United States)

Borghetti, C.; Beaven, A.; Pugliese, R.

2015-01-01

The study presented in this article aims to explore if and how intercultural learning may take place in students' class interaction. It is grounded in the assumption that interculturality is not a clear-cut feature inherent to interactions occurring when individuals with presumed different linguistic and cultural/national backgrounds talk to each…

Exploring the Concern about Food Allergies among Secondary School and University Students in Ontario, Canada: A Descriptive Analysis.

Science.gov (United States)

Majowicz, Shannon E; Jung, James K H; Courtney, Sarah M; Harrington, Daniel W

2017-01-01

Our objective was to explore the perceived risk of food allergies among students in Ontario, Canada. We analyzed blinding questions ("I am concerned about food allergies"; "food allergies are currently a big threat to my health") from three existing food safety surveys, given to high school and university undergraduate students ( n = 3,451) circa February 2015, using descriptive analysis, and explored how concern related to demographics and self-reported cooking ability using linear regression. Overall, high school students were neutral in their concern, although Food and Nutrition students specifically were significantly less concerned ( p = 0.002) than high school students overall. University undergraduates were moderately unconcerned about food allergies. Concern was highest in younger students, decreasing between 13 and 18 years of age and plateauing between 19 and 23 years. Among students aged 13-18 years, concern was higher among those who worked or volunteered in a daycare and who had previously taken a food preparation course. Among students aged 19-23 years, concern was higher among females and those with less advanced cooking abilities. Concern was significantly correlated with perceiving food allergies as a personal threat. This study offers a first exploration of perceived risk of food allergies among this demographic and can guide future, more rigorous assessments.

Analysis of mutagenic effects induced by carbon beams at different LET in a red yeast strain

International Nuclear Information System (INIS)

Sun Haining; Wang Jufang; Ma Shuang; Lu Dong; Wu Xin; Li Wenjian

2011-01-01

To evaluate inactive and mutagenic effects of carbon beam at different LET, the inactivation cross section and mutation cross section induced by carbon beams of different LET values were investigated in a red yeast strain Rhodotorula glutinis AY 91015. It was found that the maximum inactivation cross section of 4.37μm 2 , which was very close to the average nucleus cross section, was at LET of 120.0 keV/μm. The maximum mutation cross section was at LET of 96.0 keV/μm. Meanwhile, the highest mutagenicity of carbon ion was found around 58.2 keV/μm. It implied that the most efficient LET to induce mutation in survival yeasts was 58.2 keV/μm, which corresponded to energy of 35 MeV/u carbon beam. The most effective carbon beam to induce inactivation and mutation located at different energy region. (authors)

LET’s start new a LETS: Learning from a case-study investigation in Brno, Czech Republic

Directory of Open Access Journals (Sweden)

Lukáš Kala

2013-12-01

Full Text Available This paper brings information about the operation of RozLEŤSe, a LETS (Local Exchange Trading System network, based inBrno. LETS are parallel sustainable monetary systems, in which local community networks attempt to extricate themselves from the international economy by using their own currency. LETS is supposed to promote sustainable development by localising economic development. Although, there used to be several LETS group in the Czech Republic, all of them vanished during the first few years of the new millennium.  RozLEŤSe was built from the remains of former LETS groups. Hence, the aim of this study is to determine possible threats to the future existence of the group and evaluate its current operations. This research is a sociological case study investigation examining the socio-demographic characteristics, motivations and organisational functioning of the group. We point out some serious threats to the group (lack of supply, growth in negative credit, decrease in trust and offer possible solutions. 

Utilizing Science Outreach to Foster Professional Skills Development in University Students

Science.gov (United States)

Eng, Edward; Febria, Catherine

2011-01-01

Students seek unique experiences to obtain and enhance professional development skills and to prepare for future careers. Through the Let's Talk Science Partnership Program (LTSPP), a voluntary science outreach program at University of Toronto Scarborough, students are given the opportunity to continually improve on skills which include: the…

Student ID Cards: What You Should Know About Them

Science.gov (United States)

Hoffman, Jonathan; McGuire, Agnes C.

1973-01-01

Discusses the usefulness of photo ID cards for school security purposes, library control, student activities, and bus transportation control. Examines ways in which card costs can be reduced and the pros and cons of producing the cards at the school or of letting the work out. Problems involving card abuse and student rights are also considered.…

What's the Point?: An Exploration of Students' Motivation to Learn in a First-Year Seminar

Science.gov (United States)

Jessup-Anger, Jody E.

2011-01-01

This qualitative case study explores how undergraduate students and their instructor made meaning of students' motivation to learn in a one-credit, pass/fail first-year seminar. The findings point to the importance of addressing structural motivational barriers and ensuring that instructors possess the instructional, motivational, and…

Cooperative interplay of let-7 mimic and HuR with MYC RNA.

Science.gov (United States)

Gunzburg, Menachem J; Sivakumaran, Andrew; Pendini, Nicole R; Yoon, Je-Hyun; Gorospe, Myriam; Wilce, Matthew C J; Wilce, Jacqueline A

2015-01-01

Both RNA-binding proteins (RBP) and miRNA play important roles in the regulation of mRNA expression, often acting together to regulate a target mRNA. In some cases the RBP and miRNA have been reported to act competitively, but in other instances they function cooperatively. Here, we investigated HuR function as an enhancer of let-7-mediated translational repression of c-Myc despite the separation of their binding sites. Using an in vitro system, we determined that a let-7 mimic, consisting of single-stranded (ss)DNA complementary to the let-7 binding site, enhanced the affinity of HuR for a 122-nt MYC RNA encompassing both binding sites. This finding supports the biophysical principle of cooperative binding by an RBP and miRNA purely through interactions at distal mRNA binding sites.

Depth-Dose and LET Distributions of Antiproton Beams in Various Target Materials

DEFF Research Database (Denmark)

Herrmann, Rochus; Olsen, Sune; Petersen, Jørgen B.B.

the annihilation process. Materials We have investigated the impact of substituting the target material on  the depth-dose distribution of pristine and  spread out antiproton beams using the FLUKA Monte Carlo transport program. Classical ICRP targets are compared to water phantoms. In addition, track average...... unrestricted LET is calculated for all configurations. Finally, we investigate which concentrations of gadolinium and boron are needed in a water target in order to observe a significant change in the antiproton depth-dose distribution.  Results Results indicate, that there is no significant change...... in the depth-dose distribution and average LET when substituting the materials. Adding boron and gadolinium up to concentrations of 1 per 1000 atoms to a water phantom, did not change the depth-dose profile nor the average LET. Conclusions  According to our FLUKA calculations, antiproton neutron capture...

Don't Waste My Time; Exploring the Reflective Journaling Requirement in the Student Teaching Experience

Science.gov (United States)

Spiker, Amy

2014-01-01

For many years reflective journaling has been a required component of the student teaching experience at the University of Wyoming. Through action research, Amy Spiker, an instructor at the University of Wyoming, set out to explore the perceived disconnect between what faculty desires for and from student teachers and what student teachers view as…

Pro-Social Behavior Amongst Students of Tertiary Institutions: An Explorative and a Quantitative Approach

Science.gov (United States)

Quain, Samuel; Yidana, Xiaaba Dantallah; Ambotumah, Bernard Baba; Mensah-Livivnstone, Ike Joe Nii Annang

2016-01-01

The purpose of this paper was to explore antecedents of pro-social behavior amongst university students, using a private university as a case study. Following an explorative research, the study was guided by some theories relating to the phenomenon, focusing on gender and location factors. A quantitative approach was used in the follow up to the…

Exploring gender differences in attitudes of university students towards entrepreneurship

OpenAIRE

Dabić, M; Daim, T; Bayraktaroglu, E; Novak, I; Basic, M

2012-01-01

Purpose - The purpose of this paper is to understand gender differences in entrepreneurial intentions as measured by perceived feasibility and perceived desirability, and to explore gender differences in perceptions of entrepreneurship education needs - in terms of programmes, activities or projects - to succeed in an entrepreneurial career from the university students’ point of view. Design/Methodology/Approach - Using data gathered from 3420 university students in more than 10 countries, an...

Internal high linear energy transfer (LET) targeted radiotherapy for cancer

International Nuclear Information System (INIS)

Allen, Barry J

2006-01-01

High linear energy transfer (LET) radiation for internal targeted therapy has been a long time coming on to the medical therapy scene. While fundamental principles were established many decades ago, the clinical implementation has been slow. Localized neutron capture therapy, and more recently systemic targeted alpha therapy, are at the clinical trial stage. What are the attributes of these therapies that have led a band of scientists and clinicians to dedicate so much of their careers? High LET means high energy density, causing double strand breaks in DNA, and short-range radiation, sparing adjacent normal tissues. This targeted approach complements conventional radiotherapy and chemotherapy. Such therapies fail on several fronts. Foremost is the complete lack of progress for the control of primary GBM, the holy grail for cancer therapies. Next is the inability to regress metastatic cancer on a systemic basis. This has been the task of chemotherapy, but palliation is the major application. Finally, there is the inability to inhibit the development of lethal metastatic cancer after successful treatment of the primary cancer. This review charts, from an Australian perspective, the developing role of local and systemic high LET, internal radiation therapy. (review)

Developing Self-Efficacy: Exploring Preservice Coursework, Student Teaching, and Professional Development Experiences

Science.gov (United States)

McKim, Aaron J.; Velez, Jonathan J.

2017-01-01

To extend current understanding of school-based agriculture teacher development, this study explored the relationship between teacher development experiences and the self-efficacy of early career agriculture teachers. Three teacher development experiences were of interest: (a) preservice coursework, (b) student teaching, and (c) professional…

Expression of hsa Let-7a MicroRNA of Macrophages Infected by Leishmania Major

Directory of Open Access Journals (Sweden)

Nooshin Hashemi

2016-10-01

Full Text Available Leishmaniasis is a vector-born disease caused by species of the genus Leishmania and is transmitted from host to host through the bite of an infected sandfly. MicroRNAs (miRNAs are non-coding small RNAs with 22-nucleotide length. They are involved in some biological and cellular processes. We aimed to evaluate the expression of let-7a in human macrophages miRNA when are infected by Leishmania major. We also evaluated the impact of Leishmania major infection on the expression of let-7a at two different times, 24 and 48 hours, after infection. Blood samples were collected from ten healthy volunteers with no history of leishmaniasis. Development of macrophages from peripheral monocytes and infection with stationary phase of Leishmania major promastigotes were done through serial cultures under 5% CO2 environment and 37C. To measure the expression levels of let-7a real-time PCR was performed with specific related primers using the SYBR® Green master mix Kit™. The real-time PCR showed let-7a was expressed in cells infected with parasites after 24 and 48h post-infection. Comparison of let-7a miRNA expression after 24 and 48 h revealed that let-7a miRNAs were down-regulated at 48 h post-infection more than 24h after infection. The results of this study suggest that according to the main function of miRNA in repression of mRNA translation it could be possible to manipulate host cells in order to alter miRNA levels and regulate macrophage functions after establishment of intracellular parasites such as Leishmania.

`Hard science': a career option for socially and societally interested students? Grade 12 students' vocational interest gap explored

Science.gov (United States)

Struyf, Annemie; Boeve-de Pauw, Jelle; Van Petegem, Peter

2017-11-01

A key theme in science education research concerns the decline in young peoples' interest in science and the need for professionals in hard science. Goal Congruity Theory posits that an important aspect of the decision whether to pursue hard science for study or as a career is the perception that hard science careers do not fulfil social (working with people) and societal (serving or helping others) interests. In this qualitative study, we explore grade 12 students' perceptions about the social and societal orientation of hard science careers. Furthermore, we investigate the variation in students' social and societal interests. Six focus groups were conducted with 58 grade 12 students in Flanders. Our results indicate that a number of students hold stereotypical views about hard science careers' social orientation, while others believe cooperation with others is an important aspect of hard science careers nowadays. Furthermore, our results show that students believe hard science careers can be societally oriented in the sense that they often associate them with innovation or societal progress. Finally, our results indicate that students may differentiate direct versus indirect societal orientation. These findings contribute to literature regarding social and societal interests and students' perceptions of hard science careers.

Let's Turn Things on Their Head--Teaching Counterintuitive Science

Science.gov (United States)

Kumar, David

2017-01-01

Teaching science through counterintuitive events is an effective way of engaging students in exploring science; such events motivate and involve students in solving problems with a high degree of creativity and critical thinking. This can push students into a seeking explanation mode, setting the stage for discovery. In this article, the author…

Microglial-derived miRNA let-7 and HMGB1 contribute to ethanol-induced neurotoxicity via TLR7.

Science.gov (United States)

Coleman, Leon G; Zou, Jian; Crews, Fulton T

2017-01-25

Toll-like receptor (TLR) signaling is emerging as an important component of neurodegeneration. TLR7 senses viral RNA and certain endogenous miRNAs to initiate innate immune responses leading to neurodegeneration. Alcoholism is associated with hippocampal degeneration, with preclinical studies linking ethanol-induced neurodegeneration with central innate immune induction and TLR activation. The endogenous miRNA let-7b binds TLR7 to cause neurodegeneration. TLR7 and other immune markers were assessed in postmortem human hippocampal tissue that was obtained from the New South Wales Tissue Bank. Rat hippocampal-entorhinal cortex (HEC) slice culture was used to assess specific effects of ethanol on TLR7, let-7b, and microvesicles. We report here that hippocampal tissue from postmortem human alcoholic brains shows increased expression of TLR7 and increased microglial activation. Using HEC slice culture, we found that ethanol induces TLR7 and let-7b expression. Ethanol caused TLR7-associated neuroimmune gene induction and initiated the release let-7b in microvesicles (MVs), enhancing TLR7-mediated neurotoxicity. Further, ethanol increased let-7b binding to the danger signaling molecule high mobility group box-1 (HMGB1) in MVs, while reducing let-7 binding to classical chaperone protein argonaute (Ago2). Flow cytometric analysis of MVs from HEC media and analysis of MVs from brain cell culture lines found that microglia were the primary source of let-7b and HMGB1-containing MVs. Our results identify that ethanol induces neuroimmune pathology involving the release of let-7b/HMGB1 complexes in microglia-derived microvesicles. This contributes to hippocampal neurodegeneration and may play a role in the pathology of alcoholism.

Exploring Graduate Students' Perspectives towards Using Gamification Techniques in Online Learning

Directory of Open Access Journals (Sweden)

Daniah ALABBASI

2017-07-01

Full Text Available Teachers and educational institutions are attempting to find an appropriate strategy to motivate as well as engage students in the learning process. Institutions are encouraging the use of gamification in education for the purpose of improving the intrinsic motivation as well as engagement. However, the students’ perspective of the issue is under-investigated. The purpose of this research study was to explore graduate students’ perspectives toward the use of gamification techniques in online learning. The study used exploratory research and survey as the data collection tool. Forty-seven graduate students (n = 47 enrolled in an instructional technology program studied in a learning management system that supports gamification (TalentLMS. The average total percentages were calculated for each survey section to compose the final perspective of the included students. The results showed a positive perception toward the use of gamification tools in online learning among graduate students. Students require effort-demanding, challenging, sophisticated learning systems that increase competency, enhance recall memory, concentration, attentiveness, commitment, and social interaction. Limitations of the study are identified, which highlights the need for further research on the subject matter.

EXPLORING THE RELATIONS BETWEEN STUDENT CYNICISM AND STUDENT BURNOUT.

Science.gov (United States)

Wei, Xueyan; Wang, Rongrong; Macdonald, Elizabeth

2015-08-01

Research on the negative effects of student cynicism has been limited, especially regarding its relation to student burnout. This study examined the relations among student cynicism (policy cynicism, academic cynicism, social cynicism, and institutional cynicism) and student burnout, as evidenced by emotional exhaustion, depersonalization, and reduced personal accomplishment, in a sample of 276 Chinese undergraduates. Hierarchical multiple regressions showed that four aspects of student cynicism together explained substantial variance in student burnout. Policy cynicism was the strongest contributor to emotional exhaustion. Social cynicism was the primary contributor to depersonalization, and also to reduced personal accomplishment. Student cynicism overall had the strongest relationship with reduced sense of personal achievement. The findings outline the negative functional relations between student cynicism and student burnout.

Behaviour of medical students in seeking mental and physical health care: exploration and comparison with psychology students.

Science.gov (United States)

Brimstone, Renee; Thistlethwaite, Jill E; Quirk, Frances

2007-01-01

Doctors are often reluctant to seek health care through the usual channels and tend to self-diagnose and prescribe. Medical students learn attitudes and values from clinician role models and may also adopt behaviour patterns that lead them to seek help for physical and mental health problems from informal sources. This study aimed to explore the behaviour of students in seeking health care for physical and mental health problems, comparing medical with psychology students, and to understand what barriers to conventional routes of seeking health care may affect this. We administered a questionnaire asking for demographic details and responses to 2 vignettes in which a student from the respondent's discipline was experiencing firstly symptoms of a mental health problem and secondly symptoms of a physical health problem. Data were analysed with spss and univariate anovas to examine differences between respondents. A total of 172 students at the psychology and medical schools at James Cook University in Australia participated. We identified a number of barriers affecting student behaviour in seeking help, which included worries about knowing the doctor they could consult at the university health centre or having future dealings with him or her, and cost of treatment. There were differences between the 2 groups of students. There are several barriers for both psychology and medical students to accessing appropriate professional mental health care. Medical students also experience barriers to attaining appropriate physical health care when needed. Psychology and medical students were more likely to seek advice informally from friends and/or family with regard to mental health care.

I'm Not the Gingerbread Man! Exploring the Experiences of College Students Diagnosed with ADHD

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Perry, Susan N.; Franklin, Kathy K.

2006-01-01

This study explored how undergraduate students diagnosed with AD/HD remain in college. Using a qualitative research design from a grounded theory perspective, the researchers captured the personal stories of 10 college students from two universities similar in location, size, and liberal arts tradition. The findings included themes related to…

Let-7i attenuates human brain microvascular endothelial cell damage in oxygen glucose deprivation model by decreasing toll-like receptor 4 expression.

Science.gov (United States)

Xiang, Wei; Tian, Canhui; Peng, Shunli; Zhou, Liang; Pan, Suyue; Deng, Zhen

2017-11-04

The let-7 family of microRNAs (miRNAs) plays an important role on endothelial cell function. However, there have been few studies on their role under ischemic conditions. In this study, we demonstrate that let-7i, belonging to the let-7 family, rescues human brain microvascular endothelial cells (HBMECs) in an oxygen-glucose deprivation (OGD) model. Our data show that the expression of let-7 family miRNAs was downregulated after OGD. Overexpression of let-7i significantly alleviated cell death and improved survival of OGD-treated HBMECs. Let-7i also protected permeability in an in vitro blood brain barrier (BBB) model. Further, let-7i downregulated the expression of toll-like receptor 4 (TLR4), an inflammation trigger. Moreover, overexpression of let-7i decreased matrix metallopeptidase 9 (MMP9) and inducible nitric oxide synthase (iNOS) expression under OGD. Upon silencing TLR4 expression in HBMECs, the anti-inflammatory effect of let-7i was abolished. Our research suggests that let-7i promotes OGD-induced inflammation via downregulating TLR4 expression. Copyright © 2017 Elsevier Inc. All rights reserved.

Ionization chambers for LET determination

DEFF Research Database (Denmark)

Kaiser, Franz-Joachim; Bassler, Niels; Tölli, Heikki

2010-01-01

resolution and high sensitivity are necessary. For exact dosimetry which is done using ionization chambers (ICs), the recombination taking place in the IC has to be known. Up to now, recombination is corrected phenomenologically and more practical approaches are currently used. Nevertheless, Jaff´e's theory...... of columnar recombination was designed to model the detector efficiency of an ionization chamber. Here, we have shown that despite the approximations and simplification made, the theory is correct for the LETs typically found in clinical radiotherapy employing particles from protons to carbon ions...

Qualitative exploration of the career aspirations of rural origin health science students in South Africa.

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Diab, Paula N; Flack, Penny S; Mabuza, Langalibalele H; Reid, Stephen J Y

2012-01-01

There is evidence in the literature that rural background significantly encourages eventual rural practice. Given the shortage of healthcare providers in rural areas, we need to explore ways of ensuring throughput and success of rural-origin students in health sciences. It is therefore important to understand who these students are, what motivates them and the factors involved in the formation of their career choices. The aim of this study is to understand the aspirations of undergraduate health science students of rural origin with regard to their future career plans. The objectives of the study include to explore and identify the key issues facing rural-origin students with regard to their future career plans. Individual interviews were conducted with 15 health science students from two South African universities. Transcriptions were analyzed with the aid of Nvivo v8 (www.qsrinternational.com). The findings suggest health science students of rural origin studying at universities in the South African context face specific challenges related to the nature of the contrast between rural and urban life, in addition to the more generic adaptations that confront all students on entering tertiary education. In order to support rural students in their studies, academic, financial, emotional and social stressors need to be addressed. Universities should strengthen existing support structures as well as aid the development of further support that may be required.Key words: career plan, health science, rural background, South Africa.

Educational Debt in the Context of Career Planning: A Qualitative Exploration of Medical Student Perceptions.

Science.gov (United States)

Phillips, Julie P; Wilbanks, Deana M; Salinas, Diana F; Doberneck, Diane M

2016-01-01

Phenomenon: Medical students in the United States face increasing educational debt because medical education costs have risen while public investment in higher education has declined. Contemporary students borrow more money and accumulate debt far surpassing that of previous generations of physicians, and both interest rates and terms of loan repayment have changed significantly in the last decade. As a result, the experiences of medical students differ from the experiences of physician educators. Little is known about how contemporary medical students view their debt in the context of career planning. Understanding contemporary U.S. medical students' lived experiences of educational debt is important, because high debt levels may affect medical students' well-being and professional development. The study's purpose was to explore contemporary students' views of their debt in the context of career planning. In 2012, 2nd-year medical students enrolled in a health policy course at one medical school were invited to write an essay about how debt influences their career choices. The authors analyzed 132 essays using immersion and crystallization and iterative, team-based coding. Code-recode strategies, member checking, and reflexivity ensured validity and rigor. Three themes emerged about the meaning of debt: debt symbolizes lack of social investment, debt reinforces a sense of entitlement, and debt is a collective experience. Four approaches to debt management emerged: anticipation, avoidance, acceptance, and disempowerment. Insights: Medical students' views of debt are more complex than previously reported. Medical educators should recognize that many students experience debt as a stressor, acknowledge students' emotions about debt, and invite discussion about the culture of entitlement in medical education and how this culture affects students' professionalism. At the same time, educators should emphasize that students have many repayment options and that regardless

Hsa-let-7a functions as a tumor suppressor in renal cell carcinoma cell lines by targeting c-myc

Energy Technology Data Exchange (ETDEWEB)

Liu, Yongchao; Yin, Bingde; Zhang, Changcun; Zhou, Libin [Department of Urology, Shanghai First People' s Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200080 (China); Fan, Jie, E-mail: jief67@sina.com [Department of Urology, Shanghai First People' s Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200080 (China)

2012-01-06

Highlights: Black-Right-Pointing-Pointer This study is the first to test the let-7a/c-myc loop in renal cell carcinoma cell lines. Black-Right-Pointing-Pointer Let-7a down-regulated c-myc in three renal cell carcinoma cell lines. Black-Right-Pointing-Pointer c-myc target genes were down-regulated because of the let-7a-mediated down-regulation of c-myc. Black-Right-Pointing-Pointer The let-7a/c-myc loop has a significant function in renal cell carcinoma cell lines. -- Abstract: Widespread functions of the c-myc pathway play a crucial role in renal cell carcinoma (RCC) carcinogenesis. Thus, we evaluated the connection between proto-oncogenic c-myc and anti-neoplastic hsa-let-7a (let-7a) in RCC cell lines. The levels of c-myc and let-7a in 3 RCC cell lines (769P, Caki-1 and 786O) were measured after transfecting the cells with let-7a mimics or a negative control. The change in c-myc protein level was confirmed by Western blot. The anti-neoplastic function of let-7a was evaluated using cell counting kit-8 (CCK-8) for proliferation analysis and cell flow cytometry for cell cycle analysis. The changes of downstream targets of c-myc were measured using reverse transcription quantitative real-time PCR (qRT-PCR). Our results suggest for the first time that let-7a acts as a tumor suppressor in RCC cell lines by down-regulating c-myc and c-myc target genes such as proliferating cell nuclear antigen (PCNA), cyclin D1 (CCND1) and the miR17-92 cluster, which is accompanied by proliferation inhibition and cell cycle arrest.

A method for radiobiological investigations in radiation fields with different LET and high dose rates

International Nuclear Information System (INIS)

Grundler, W.

1976-01-01

For investigations: 1. Performed in the field of radiobiology with different LET-radiation and a relatively high background dose rate of one component (e.g. investigations with fast and intermediate reactor neutrons) 2. Concerning radiation risk studies within a wide range 3. Of irradiations, covering a long time period (up to 100 days) a test system is necessary which on the one hand makes it possible to analyze the influence of different LET radiation and secondly shows a relative radiation resistant behaviour and allows a simple cell cycle regulation. A survey is given upon the installed device of a simple cell observation method, the biological test system used and the analysis of effects caused by dose, repair and LET. It is possible to analyze the behaviour of the nonsurvival cells and to demonstrate different reactions of the test parameters to the radiation of different LET. (author)

Effects of estrogen and gender on cataractogenesis induced by high-LET radiation

International Nuclear Information System (INIS)

Henderson, M.A.; Rusek, A.; Valluri, S.; Garrett, J.; Lopez, J.; Caperell-Grant, A.; Mendonca, M.; Bigsby, R.; Dynlacht, J.

2010-01-01

Planning for long-duration manned lunar and interplanetary missions requires an understanding of radiation-induced cataractogenesis. Previously, it was demonstrated that low-linear energy transfer (LET) irradiation with 10 Gy of 60 Co γ rays resulted in an increased incidence of cataracts in male rats compared to female rats. This gender difference was not due to differences in estrogen, since male rats treated with the major secreted estrogen 17-β-estradiol (E2) showed an identical increase compared to untreated males. We now compare the incidence and rate of progression of cataracts induced by high-LET radiation in male and female Sprague-Dawley rats. Rats received a single dose of 1 Gy of 600 MeV 56 Fe ions. Lens opacification was measured at 2-4 week intervals with a slit lamp. The incidence and rate of progression of radiation-induced cataracts was significantly increased in the animals in which estrogen was available from endogenous or exogenous sources. Male rats with E2 capsules implanted had significantly higher rates of progression compared to male rats with empty capsules implanted (P = 0.025) but not compared to the intact female rats. These results contrast with data obtained after low-LET irradiation and suggest the possibility that the different types of damage caused by high- and low-LET radiation may be influenced differentially by steroid sex hormones.

Exploring Elementary-School Students' Engagement Patterns in a Game-Based Learning Environment

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Hsieh, Ya-Hui; Lin, Yi-Chun; Hou, Huei-Tse

2015-01-01

Unlike most research, which has primarily examined the players' interest in or attitude toward game-based learning through questionnaires, the purpose of this empirical study is to explore students' engagement patterns by qualitative observation and sequential analysis to visualize and better understand their game-based learning process. We…

Appraising the Qualities of Social Work Students' Theoretical Knowledge: A Qualitative Exploration

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van Bommel, Marijke; Boshuizen, Henny P. A.; Kwakman, Kitty

2012-01-01

Higher professional education aims to prepare students for entering practice with an adequate theoretical body of knowledge. In constructivist programmes, authentic learning contexts and self-directed learning are assumed to support knowledge learning and the transition from education to practice. Through an in-depth exploration, this case study…

Culturally and linguistically diverse students in health professional programs: an exploration of concerns and needs.

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Gilligan, C; Outram, S

2012-07-01

Cultural diversity among students in tertiary institutions in Australia and globally has increased rapidly in the last decade, and is continuing to do so. Focus groups were held at the University of Newcastle, NSW to: (1) examine the specific needs of international students in the Master of Pharmacy, Bachelor of Medicine and Bachelor of Nursing programs in relation to language and cultural considerations and (2) to understand the attitudes of domestic students to the cultural issues faced among their peers. The project explored these issues with the intention to inform curricula changes to accommodate the needs of culturally and linguistically diverse students. The key themes emerging from international students were: difficulties in spoken language, differences in professional roles and expectations, differences in methods of learning, inadequate social interaction outside the classroom and acceptance of differences in cultural and religious practices. The domestic student views reinforced the comments from international students both in regard to social interaction and in regard to participation in class discussions. Although local students were interested in learning from international students about their culture and religious beliefs, there were limited initiatives from both sides. There is a need for tertiary institutions that benefit economically from increasing the numbers of international students to help them to study and live in a new environment. Assistance needs to go beyond learning the English language to helping students understand its use in a professional context (health terminology and slang used by patients), the nuances of the health professional disciplines in a western society, the approach to study and problem-based learning styles and skills to assist with social interaction. The results of the present exploration have led to a series of proposed actions for the University of Newcastle. These recommendations are applicable to any "Western

Exploring pre-service science teachers' pedagogical capacity for formative assessment through analyses of student answers

Science.gov (United States)

Aydeniz, Mehmet; Dogan, Alev

2016-05-01

Background: There has been an increasing emphasis on empowering pre-service and in-service science teachers to attend student reasoning and use formative assessments to guide student learning in recent years. Purpose: The purpose of this study was to explore pre-service science teachers' pedagogical capacity for formative assessment. Sample: This study took place in Turkey. The participants include 53 pre-service science teachers in their final year of schooling. All but two of the participants are female. Design and methods: We used a mixed-methods methodology in pursing this inquiry. Participants analyzed 28 responses to seven two-tiered questions given by four students of different ability levels. We explored their ability to identify the strengths and weaknesses in students' answers. We paid particular attention to the things that the pre-service science teachers noticed in students' explanations, the types of inferences they made about students' conceptual understanding, and the affordances of pedagogical decisions they made. Results: The results show that the majority of participants made an evaluative judgment (i.e. the answer is correct or incorrect) in their analyses of students' answers. Similarly, the majority of the participants recognized the type of mistake that the students made. However, they failed to successfully elaborate on fallacies, limitations, or strengths in student reasoning. We also asked the participants to make pedagogical decisions related to what needs to be done next in order to help the students to achieve academic objectives. Results show that 8% of the recommended instructional strategies were of no affordance, 64% of low-affordance, and 28% were of high affordance in terms of helping students achieve the academic objectives. Conclusion: If our goal is to improve pre-service science teachers' noticing skills, and the affordance of feedback that they provide, engaging them in activities that asks them to attend to students' ideas

Learning experiences on role-emerging placements: an exploration from the students' perspective.

Science.gov (United States)

Dancza, Karina; Warren, Alison; Copley, Jodie; Rodger, Sylvia; Moran, Monica; McKay, Elizabeth; Taylor, Ann

2013-12-01

Occupational therapy educators are challenged to provide students with practical experiences which prepare them for ever changing health-care contexts on graduation. Role-emerging placements have been widely used internationally to help meet this challenge, but research into the learning experiences of students during these innovative placements is limited. This research investigated the enablers and barriers to learning from the perspectives of students on such placements from two European universities. Two separate qualitative studies tracked 10 final year students. Interviews explored their learning experiences prior to, during and after an eight- or 10-week role-emerging placement in a range of settings. Four themes emerged, which were (1) adapting to less doing, more thinking and planning; (2) understanding the complexity of collaboration and making it work; (3) emotional extremes; and (4) realising and using the occupational therapy perspective. These placements presented a 'roller coaster' of authentic learning experiences which created the opportunity for students to use occupation in practice and develop skills for collaborative working in an interprofessional environment. Whereas students viewed their role-emerging placement experiences positively, challenges included the emotional responses of students and placement pace. Findings suggest the need for supportive student placement experiences in both established and role-emerging areas to prepare students for a range of opportunities in an uncertain future. © 2013 Occupational Therapy Australia.

Students as Non-Standard Employees. Exploring Work Related Issues in Students’ Perceptions on their Term-time Job

DEFF Research Database (Denmark)

Winkler, Ingo

2008-01-01

The article presents the results of an explorative study that aimed at exploring work related issues in students’ perceptions of their job as atypical employees. An individual picture of the experienced work reality of students is drawn according to work task, flexible working hours, instructions...... and training opportunities, students’ relations to other employees, and social integration. By adopting a qualitative design, I was able to emphasize the subjective perspective of students describing their very own experiences as flexible workers. The study revealed various perceptions of students working...... as flexible employees and related this picture to current empirical and theoretical research in the field of non-standard employment....

Who perceives they are smarter? Exploring the influence of student characteristics on student academic self-concept in physiology.

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Cooper, Katelyn M; Krieg, Anna; Brownell, Sara E

2018-06-01

Academic self-concept is one's perception of his or her ability in an academic domain and is formed by comparing oneself to other students. As college biology classrooms transition from lecturing to active learning, students interact more with each other and are likely comparing themselves more to other students in the class. Student characteristics can impact students' academic self-concept; however, this has been unexplored in the context of undergraduate biology. In this study, we explored whether student characteristics can affect academic self-concept in the context of an active learning college physiology course. Using a survey, students self-reported how smart they perceived themselves to be in the context of physiology relative to the whole class and relative to their groupmate, the student with whom they worked most closely in class. Using linear regression, we found that men and native English speakers had significantly higher academic self-concept relative to the whole class compared with women and nonnative English speakers. Using logistic regression, we found that men had significantly higher academic self-concept relative to their groupmate compared with women. Using constant comparison methods, we identified nine factors that students reported influenced how they determined whether they were more or less smart than their groupmate. Finally, we found that students were more likely to report participating more than their groupmate if they had a higher academic self-concept. These findings suggest that student characteristics can influence students' academic self-concept, which in turn may influence their participation in small-group discussion and their academic achievement in active learning classes.

Teaching medical students to express empathy by exploring patient emotions and experiences in standardized medical encounters.

Science.gov (United States)

Ruiz-Moral, Roger; Pérula de Torres, Luis; Monge, Diana; García Leonardo, Cristina; Caballero, Fernando

2017-09-01

To increase medical students' ability to detect contextual and emotional cues and to respond empathetically to patients. a training course in communication skills and patient-centered care with different teaching activities (didactic, reflective and interactive: workshops and encounters with simulated patients) was delivered to third-year medical students just before their clerkships. The program was evaluated by an external observer (OE) and simulated patients (SP) in 2 or 3 videotaped encounters. Students improved significantly from baseline to 3rd interview in all communicative skills and domains explored both in OE (32.4%) and SP (38.3%) measurement. At the end of the course students detected significantly more clues and made more empathetic expressions. The course seems to improve the ability of students to explore the illness experience, showing more empathy in a more genuine way. This was carried out in consultations lasting 10min. The program is effective and feasible to be applied as a regular formative activity. Further research is needed to assess whether this training program is applicable to students in more advanced educational levels and if it has any additional outcomes. Copyright © 2017 Elsevier B.V. All rights reserved.

Exploring Learners' Conceptual Resources: Singapore a Level Students' Explanations in the Topic of Ionisation Energy

Science.gov (United States)

Taber, Keith S.; Tan, Kim Chwee Daniel

2007-01-01

This paper describes findings from a study to explore Singapore A-level (Grades 11 and 12, 16-19 yr old) students' understanding of ionisation energy, an abstract and complex topic that is featured in school chemistry courses. Previous research had reported that students in the United Kingdom commonly use alternative notions based on the perceived…

LET effect on irradiation of hydroxyphthal imide in alcohol solutions

International Nuclear Information System (INIS)

Nakagawa, S.; Murakami, T.

2005-01-01

Hydroxyphthalimide(C 6 H 4 (CO) 2 -NOH) was irradiated with C ion (290MeV/u) in isopropyl alcohol, methanol, ethanol, and acetonitrile. LET was 13.2 and 26.5 keV/m. Dose was 5 and 10 kGy. A little amount of phthalimide was produced. The G value of the production of phthalimide by ion irradiation was less than that by -irradiation except for in methanol. In methanol solution, the production rate of phthalimide increased with increasing the value of LET. The amount of the substitution for C 6 H 4 (CO) 2 -NOD in methanol-d decreased by ion irradiation. These results suggest that the reaction mechanism in ion irradiation is different from -irradiation. (author)

College Students and Financial Distress: Exploring Debt, Financial Satisfaction, and Financial Anxiety

Science.gov (United States)

Archuleta, Kristy L.; Dale, Anita; Spann, Scott M.

2013-01-01

The impact of financial concerns on overall mental health has become a popular topic among researchers and practitioners. In this exploratory study, possible associations of financial anxiety were explored using a sample of 180 college students who sought services at a university peer financial counseling center in a Midwestern state. Of…

MicroRNA hsa-let-7b suppresses the odonto/osteogenic differentiation capacity of stem cells from apical papilla by targeting MMP1.

Science.gov (United States)

Wang, Yanqiu; Pang, Xiyao; Wu, Jintao; Jin, Lin; Yu, Yan; Gobin, Romila; Yu, Jinhua

2018-01-31

MicroRNA let-7 family acts as the key regulator of the differentiation of mesenchymal stem cells (MSCs). However, the influence of let-7b on biological characteristics of stem cells from apical papilla (SCAPs) is still controversial. In this study, the expression of hsa-let-7b was obviously downregulated during the osteogenic differentiation of SCAPs. SCAPs were then infected with hsa-let-7b or hsa-let-7b inhibitor lentiviruses. The proliferation ability was determined by CCK-8 and flow cytometry. The odonto/osteogenic differentiation capacity was analyzed by alkaline phosphatase (ALP) activity, alizarin red staining, Western blot assay, and real-time RT-PCR. Bioinformatics analysis was used to screen out the target of hsa-let-7b and the target relationship was confirmed by dual luciferase reporter assay. Hsa-let-7b was of no influence on the proliferation of SCAPs. Interferential expression of hsa-let-7b increased the ALP activity as well as the formation of calcified nodules of SCAPs. Moreover, the mRNA levels of osteoblastic markers (ALP, RUNX2, OSX, OPN, and OCN) were upregulated while the protein levels of DSPP, ALP, RUNX2, OSX, OPN, and OCN also increased considerably. Conversely, overexpression of hsa-let-7b inhibited the odonto/osteogenic differentiation capacity of SCAPs. Bioinformatics analysis revealed a putative binding site of hsa-let-7b in the matrix metalloproteinase 1 (MMP1) 3'-untranslated region (3'-UTR). Dual luciferase reporter assay confirmed that hsa-let-7b targets MMP1. The odonto/osteogenic differentiation ability of SCAPs ascended after repression of hsa-let-7b, which was then reversed after co-transfection with siMMP1. Together, hsa-let-7b can suppress the odonto/osteogenic differentiation capacity of SCAPs by targeting MMP1. © 2018 Wiley Periodicals, Inc.

The induction of somatic mutations by high-LET radiations using the drosophila assay system

International Nuclear Information System (INIS)

Yoshikawa, Isao; Takatsuji, Toshihiro

2004-01-01

Two types of somatic mutation in Drosophila melanogaster were examined to evaluate the relative biological effectiveness (RBE) of 252 Cf neutrons and heavy ions (carbon ions and neon ions) accelerated with a synchrotron for inducing mutations as a function of linear energy transfer (LET). One is the loss of heterozygosity for wing-hair mutations and the other the reversion of the mutant white-ivory. The measurements were made using a combined mutation assay system; so that induced mutant wing-hair clones as well as revertant eye-color clones could be detected simultaneously in the same fly. Larvae were irradiated at the age of 3 days post-oviposition. The efficiency of 252 Cf neutrons for inducing wing-hair mosaic spots is very high, RBE=8.5, but that for eye-color mosaic spot is almost equal (RBE=1.2) to that of 137 Cs γ-rays. RBE-LET relationships were obtained for the induction of wing-hair and eye-color mosaic spots. The RBE of carbon and neon ions for producing wing-hair mosaic spots increased with increasing LET values. The RBE for the induction of eye-color mutants did not change with LET. These relationships suggest that more complex types of DNA damage such as non-rejoinable strand breaks or clustered double strand breaks that increase with LET may be responsible for inducing the wing-hair mutation, while simpler forms of molecular damage may induce reversion in the white-ivory allele. (author)

VE-821, an ATR inhibitor, causes radiosensitization in human tumor cells irradiated with high LET radiation

International Nuclear Information System (INIS)

Fujisawa, Hiroshi; Nakajima, Nakako Izumi; Sunada, Shigeaki; Lee, Younghyun; Hirakawa, Hirokazu; Yajima, Hirohiko; Fujimori, Akira; Uesaka, Mitsuru; Okayasu, Ryuichi

2015-01-01

High linear energy transfer (LET) radiation such as carbon ion particles is successfully used for treatment of solid tumors. The reason why high LET radiation accomplishes greater tumor-killing than X-rays is still not completely understood. One factor would be the clustered or complex-type DNA damages. We previously reported that complex DNA double-strand breaks produced by high LET radiation enhanced DNA end resection, and this could lead to higher kinase activity of ATR protein recruited to RPA-coated single-stranded DNA. Although the effect of ATR inhibition on cells exposed to low LET gamma-rays has recently been reported, little is known regarding the effect of ATR inhibitor on cells treated with high LET radiation. The purpose of this study is to investigate the effects of the ATR inhibitor VE-821 in human tumor and normal cells irradiated with high LET carbon ions. HeLa, U2OS, and 1BR-hTERT (normal) cells were pre-treated with 1 μM VE-821 for 1 hour and irradiated with either high LET carbon ions or X-rays. Cell survival, cell cycle distribution, cell growth, and micronuclei formation were evaluated. VE-821 caused abrogation of G2/M checkpoint and forced irradiated cells to divide into daughter cells. We also found that carbon ions caused a higher number of multiple micronuclei than X-rays, leading to decreased cell survival in tumor cells when treated with VE-821, while the survival of irradiated normal cells were not significantly affected by this inhibitor. ATR inhibitor would be an effective tumor radiosensitizer with carbon ion irradiation. The online version of this article (doi:10.1186/s13014-015-0464-y) contains supplementary material, which is available to authorized users

Student nurses' experiences of community-based practice placement learning: a qualitative exploration.

Science.gov (United States)

Baglin, M R; Rugg, Sue

2010-05-01

United Kingdom (UK) health policy has adopted an increasing community and primary care focus over recent years (Department of Health, 1997; Department of Health, 1999. Making a Difference: Strengthening the Nursing, Midwifery and Health Visitor Contribution to Health and Health Care. Department of Health, London; Department of Health, 2004. The NHS Knowledge and Skills Framework (NHS KSF). Department of Health, London). Nursing practice, education and workforce planning are called upon to adapt accordingly (Department of Health, 2004. The NHS Knowledge and Skills Framework (NHS KSF). Department of Health, London; Kenyon, V., Smith, E., Hefty, L., Bell, M., Martaus, T., 1990. Clinical competencies for community health nursing. Public Health Nursing 7(1), 33-39; United Kingdom Central Council for Nursing, Midwifery and Health Visiting, 1986. Project 2000: A New Preparation for Practice. UKCC, London). Such changes have major implications for pre-registration nursing education, including its practice placement element. From an educational perspective, the need for increased community nursing capacity must be balanced with adequate support for student nurses' learning needs during community-based placements. This qualitative study explored six second year student nurses' experiences of 12 week community-based practice placements and the extent to which these placements were seen to meet their perceived learning needs. The data came from contemporaneous reflective diaries, completed by participants to reflect their 'lived experience' during their practice placements (Landeen, J., Byrne, Brown, B., 1995. Exploring the lived experiences of psychiatric nursing students through self-reflective journals. Journal of Advanced Nursing 21(5), 878-885; Kok, J., Chabeli, M.M., 2002. Reflective journal writing: how it promotes reflective thinking in clinical nursing education: a students' perspective. Curationis 25(3), 35-42; Löfmark, A., Wikblad, K., 2001. Facilitating and

A composite microdose Adaptive Response (AR) and Bystander Effect (BE) model-application to low LET and high LET AR and BE data.

Science.gov (United States)

Leonard, Bobby E

2008-08-01

It has been suggested that Adaptive Response (AR) may reduce risk of adverse health effects due to ionizing radiation. But very low dose Bystander Effects (BE) may impose dominant deleterious human risks. These conflicting behaviors have stimulated controversy regarding the Linear No-Threshold human risk model. A dose and dose rate-dependent microdose model, to examine AR behavior, was developed in prior work. In the prior work a number of in vitro and in vivo dose response data were examined with the model. Recent new data show AR behavior with some evidence of very low dose BE. The purpose of this work is to supplement the microdose model to encompass the Brenner and colleagues BaD (Bystander and Direct Damage) model and apply this composite model to obtain new knowledge regarding AR and BE and illustrate the use of the model to plan radio-biology experiments. The biophysical composite AR and BE Microdose Model quantifies the accumulation of hits (Poisson distributed, microdose specific energy depositions) to cell nucleus volumes. This new composite AR and BE model provides predictions of dose response at very low dose BE levels, higher dose AR levels and even higher dose Direct (linear-quadratic) Damage radiation levels. We find good fits of the model to both BE data from the Columbia University microbeam facility and combined AR and BE data for low Linear Energy Transfer (LET) and high LET data. A Bystander Factor of about 27,000 and an AR protection factor of 0.61 are obtained for the low LET in vivo mouse spleen exposures. A Bystander Factor of 317 and an AR protection factor of 0.53 are obtained for high LET radon alpha particles in human lymphocytes. In both cases the AR is activated at most by one or two radiation induced charged particle traversals through the cell nucleus. The results of the model analysis is consistent with a premise that both Bystander damage and Adaptive Response radioprotection can occur in the same cell type, derived from the same

Cooperative interplay of let-7 mimic and HuR with MYC RNA

OpenAIRE

Gunzburg, Menachem J; Sivakumaran, Andrew; Pendini, Nicole R; Yoon, Je-Hyun; Gorospe, Myriam; Wilce, Matthew Cj; Wilce, Jacqueline A

2015-01-01

Both RNA-binding proteins (RBP) and miRNA play important roles in the regulation of mRNA expression, often acting together to regulate a target mRNA. In some cases the RBP and miRNA have been reported to act competitively, but in other instances they function cooperatively. Here, we investigated HuR function as an enhancer of let-7-mediated translational repression of c-Myc despite the separation of their binding sites. Using an in vitro system, we determined that a let-7 mimic, consisting of...

Influence of chemical inhibitors on cell recovery after exposure to different LET radiation

Energy Technology Data Exchange (ETDEWEB)

Evstratova, Ekaterina S.; Petin, Vladislav G. [Medical Radiological Research Center, Obninsk (Russian Federation); Kim, Jin Kyu; KIm, Jin Hong [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

2016-12-15

Chemical radiosensitizers are often used to increase cell radiosensitivity. It is known that the ability of chemical drugs to increase cell radiosensitivity is related with inhibition of cell recovery from damage induced by ionizing radiation. However, there are little comparative investigations of cell sensitivity modification after exposure to radiation with high linear energy transfer (LET). Therefore, we studied the anticancer drugs cisplatin and endoxan and their impact on the ability of yeast cells to recover after cell exposure to radiations with different LET. The ability of cell recovery from radiation damage was less effective after exposure to high-LET radiation, when cells were irradiated without drug, with the increase in cisplatin concentration resulting in the disappearance of this difference. The increase of cisplatin concentration results in progressive increase in the fraction of irreversible damage independently of radiation quality.

Influence of chemical inhibitors on cell recovery after exposure to different LET radiation

International Nuclear Information System (INIS)

Evstratova, Ekaterina S.; Petin, Vladislav G.; Kim, Jin Kyu; KIm, Jin Hong

2016-01-01

Chemical radiosensitizers are often used to increase cell radiosensitivity. It is known that the ability of chemical drugs to increase cell radiosensitivity is related with inhibition of cell recovery from damage induced by ionizing radiation. However, there are little comparative investigations of cell sensitivity modification after exposure to radiation with high linear energy transfer (LET). Therefore, we studied the anticancer drugs cisplatin and endoxan and their impact on the ability of yeast cells to recover after cell exposure to radiations with different LET. The ability of cell recovery from radiation damage was less effective after exposure to high-LET radiation, when cells were irradiated without drug, with the increase in cisplatin concentration resulting in the disappearance of this difference. The increase of cisplatin concentration results in progressive increase in the fraction of irreversible damage independently of radiation quality.

Exploring Seafloor Volcanoes in Cyberspace: NOAA's "Ocean Explorer" Inspires Inquiry

Science.gov (United States)

Hjelm, Elizabeth

2011-01-01

Seafloor exploration being done by scientists is an ideal way to introduce students to technology as a tool for inquiry. The same technology that allows scientists to share data in near real time can also provide students the tools to become researchers. NOAA's Ocean Explorer Explorations website is a rich research data bank that can be used by…

Exploring Students' E-Learning Effectiveness through the Use of Line Chat Application

Science.gov (United States)

Limsuthiwanpoom, Tassaneenart; Kanthawongs, Penjira; Kanthawongs, Penjuree; Suwandee, Sasithorn

2016-01-01

This study explores the impact of motivational goals for using social networking sites (SNS) usage and computer self-efficacy towards e-learning effectiveness of the 155 students from different schools at a private university, in Pathum Thani province, Thailand during April to May of academic year 2015/2016. Social dimension and human interaction…

Neoplastic cell transformation by high-LET radiation - Molecular mechanisms

Science.gov (United States)

Yang, Tracy Chui-Hsu; Craise, Laurie M.; Tobias, Cornelius A.; Mei, Man-Tong

1989-01-01

Quantitative data were collected on dose-response curves of cultured mouse-embryo cells (C3H10T1/2) irradiated with heavy ions of various charges and energies. Results suggests that two breaks formed on DNA within 80 A may cause cell transformation and that two DNA breaks formed within 20 A may be lethal. From results of experiments with restriction enzymes which produce DNA damages at specific sites, it was found that DNA double strand breaks are important primary lesions for radiogenic cell transformation and that blunt-ended double-strand breaks can form lethal as well as transformational damages due to misrepair or incomplete repair in the cell. The RBE-LET relationship for high-LET radiation is similar to that for HGPRT locus mutation, chromosomal deletion, and cell transformation, indicating that common lesions may be involved in these radiation effects.

How we created a peer-designed specialty-specific selective for medical student career exploration.

Science.gov (United States)

Keating, Elizabeth M; O'Donnell, Erin P; Starr, Stephanie R

2013-01-01

In recent years, medical students have recognized and advocated for opportunities to explore various specialties earlier in their medical education. A brief literature review, however, reveals little consensus on the best approach to introduce students to different fields during their preclinical years. We present one of the first reports of a student-led effort to design and implement a preclinical specialty-specific elective. At Mayo Medical School, for two consecutive years the student president of the Pediatric Interest Group has created a peer-designed weeklong group elective ("selective") experience consisting of workshops, faculty and resident panel discussions, and clinical shadowing experiences based on a student needs assessment. Each year, more than 25% of the first- and second-year medical student body participated. The majority of students who completed the selective agreed that this experience heightened their interests and expanded their knowledge about pediatrics. The pediatric group selective has provided students with important resources for their medical education and future careers. Students found the group selective beneficial to their learning experience and recommend continuing to offer it in the future.

Intracellular trafficking of LET-756, a fibroblast growth factor of C. elegans, is controlled by a balance of export and nuclear signals

International Nuclear Information System (INIS)

Popovici, Cornel; Fallet, Mathieu; Marguet, Didier; Birnbaum, Daniel; Roubin, Regine

2006-01-01

The superfamily of fibroblast growth factors (FGF), which counts 22 members in humans, exerts many functions during animal development and adult life. LET-756 is one of the two FGFs of the nematode C. elegans. Re-introduction of LET-756 in a null mutant strain restores viability, allowing the study of structural requirements for LET-756 trafficking and function. LET-756 protein has several regions and motifs, including a non-classical internal motif required for secretion. We show here that a main difference in the wild-type LET-756 molecule and a truncated molecule that mimics a partial loss-of-function mutant lies on subnuclear expression. Using Cos-1 cells and rescue activity we show that: (i) nuclear localization is due to various redundant NLS, one of them acting as a nucleolar localization signal; (ii) nuclear LET-756 is addressed to the speckles by a stretch of glutamine residues; (iii) nuclear LET-756 is trafficking between speckles and nucleoli; (iv) in the nucleolus, LET-756 is associated with proteins of the rRNA splicing compartment; (v) changing LET-756 secretion signal prevents its nuclear localization. We propose that LET-756 exerts its functions through a balance between secreted and nuclear forms due to two opposite addressing signals (i) synergy of several NLS and (ii) attenuated secretion signal

An Exploration of the Attitude and Learning Effectiveness of Business College Students towards Game Based Learning

Science.gov (United States)

Chang, Chiung-Sui; Huang, Ya-Ping; Chien, Fei-Ling

2014-01-01

This study aimed to explore the attitude and learning effectiveness in game based simulations from college students' perspective. The participants included 189 business college students in Taiwan. The main instrument employed in this study was McDonald's video game. Additionally, participant selection, data collection and analysis, and results…

Dress Codes Blues: An Exploration of Urban Students' Reactions to a Public High School Uniform Policy

Science.gov (United States)

DaCosta, Kneia

2006-01-01

This qualitative investigation explores the responses of 22 U.S. urban public high school students when confronted with their newly imposed school uniform policy. Specifically, the study assessed students' appraisals of the policy along with compliance and academic performance. Guided by ecological human development perspectives and grounded in…

Exploring Student Characteristics of Retention That Lead to Graduation in Higher Education Using Data Mining Models

Science.gov (United States)

Raju, Dheeraj; Schumacker, Randall

2015-01-01

The study used earliest available student data from a flagship university in the southeast United States to build data mining models like logistic regression with different variable selection methods, decision trees, and neural networks to explore important student characteristics associated with retention leading to graduation. The decision tree…

IGF-1/IGF-1R/hsa-let-7c axis regulates the committed differentiation of stem cells from apical papilla

Science.gov (United States)

Ma, Shu; Liu, Genxia; Jin, Lin; Pang, Xiyao; Wang, Yanqiu; Wang, Zilu; Yu, Yan; Yu, Jinhua

2016-01-01

Insulin-like growth factor-1 (IGF-1) and its receptor IGF-1R play a paramount role in tooth/bone formation while hsa-let-7c actively participates in the osteogenic differentiation of mesenchymal stem cells. However, the interaction between IGF-1/IGF-1R and hsa-let-7c on the committed differentiation of stem cells from apical papilla (SCAPs) remains unclear. In this study, human SCAPs were isolated and treated with IGF-1 and hsa-let-7c over/low-expression viruses. The odonto/osteogenic differentiation of these stem cells and the involvement of mitogen-activated protein kinase (MAPK) pathway were subsequently investigated. Alizarin red staining showed that hsa-let-7c low-expression can significantly promote the mineralization of IGF-1 treated SCAPs, while hsa-let-7c over-expression can decrease the calcium deposition of IGF-1 treated SCAPs. Western blot assay and real-time reverse transcription polymerase chain reaction further demonstrated that the expression of odonto/osteogenic markers (ALP, RUNX2/RUNX2, OSX/OSX, OCN/OCN, COL-I/COL-I, DSPP/DSP, and DMP-1/DMP-1) in IGF-1 treated SCAPs were significantly upregulated in Let-7c-low group. On the contrary, hsa-let-7c over-expression could downregulate the expression of these odonto/osteogenic markers. Moreover, western blot assay showed that the JNK and p38 MAPK signaling pathways were activated in Let-7c-low SCAPs but inhibited in Let-7c-over SCAPs. Together, the IGF-1/IGF-1R/hsa-let-7c axis can control the odonto/osteogenic differentiation of IGF-1-treated SCAPs via the regulation of JNK and p38 MAPK signaling pathways. PMID:27833148

Protective Effects of Let-7b on the Expression of Occludin by Targeting P38 MAPK in Preventing Intestinal Barrier Dysfunction

Directory of Open Access Journals (Sweden)

Zhihua Liu

2018-01-01

Full Text Available Background/Aims: Let-7b was dramatically reduced after a dicer knockout of mice with intestinal barrier function injuries. This paper aims to investigate the molecular mechanism of let-7b by targeting p38 MAPK in preventing intestinal barrier dysfunction. Methods: A total of 186 patients were enrolled, with 93 in the control group and 93 in the PRO group. Only 158 patients completed the entire study, whereas the others either did not meet the inclusion criteria or refused to participate. To further verify the role of let-7b, intestinal epithelial conditional knockout (IKO mice of mmu-let-7b model were established. Serum let-7b, zonulin, IL-6, and TNF-α concentrations were measured by ELISA or quantitative RT-PCR. Permeability assay was done by ussing chamber. The apoptotic cells were identified using an In Situ Cell Death Detection Kit. Protein was detected by western blot. Results: Probiotics can lower infection-related complications, as well as increase the serum and tissue let-7b levels. P38 MAPK was identified as the target of let-7b, as verified by NCM460 cells. P38 MAPK expression was increased, whereas tight-junction (TJ proteins were significantly decreased in let-7b IKO mice (both P<0.05. Negative regulation of p38 MAPK molecular signaling pathways was involved in the protective effects of let-7b on intestinal barrier function. Conclusion: Let-7b was identified as a novel diagnosis biomarker or a potential treatment target for preventing intestinal barrier dysfunction.

Protective Effects of Let-7b on the Expression of Occludin by Targeting P38 MAPK in Preventing Intestinal Barrier Dysfunction.

Science.gov (United States)

Liu, Zhihua; Tian, Yinghai; Jiang, Yanqiong; Chen, Shihua; Liu, Ting; Moyer, Mary Pat; Qin, Huanlong; Zhou, Xinke

2018-01-01

Let-7b was dramatically reduced after a dicer knockout of mice with intestinal barrier function injuries. This paper aims to investigate the molecular mechanism of let-7b by targeting p38 MAPK in preventing intestinal barrier dysfunction. A total of 186 patients were enrolled, with 93 in the control group and 93 in the PRO group. Only 158 patients completed the entire study, whereas the others either did not meet the inclusion criteria or refused to participate. To further verify the role of let-7b, intestinal epithelial conditional knockout (IKO) mice of mmu-let-7b model were established. Serum let-7b, zonulin, IL-6, and TNF-α concentrations were measured by ELISA or quantitative RT-PCR. Permeability assay was done by ussing chamber. The apoptotic cells were identified using an In Situ Cell Death Detection Kit. Protein was detected by western blot. Probiotics can lower infection-related complications, as well as increase the serum and tissue let-7b levels. P38 MAPK was identified as the target of let-7b, as verified by NCM460 cells. P38 MAPK expression was increased, whereas tight-junction (TJ) proteins were significantly decreased in let-7b IKO mice (both P<0.05). Negative regulation of p38 MAPK molecular signaling pathways was involved in the protective effects of let-7b on intestinal barrier function. Let-7b was identified as a novel diagnosis biomarker or a potential treatment target for preventing intestinal barrier dysfunction. © 2018 The Author(s). Published by S. Karger AG, Basel.

Exploring student learning profiles in algebra-based studio physics: A person-centered approach

Science.gov (United States)

Pond, Jarrad W. T.; Chini, Jacquelyn J.

2017-06-01

In this study, we explore the strategic self-regulatory and motivational characteristics of students in studio-mode physics courses at three universities with varying student populations and varying levels of success in their studio-mode courses. We survey students using questions compiled from several existing questionnaires designed to measure students' study strategies, attitudes toward and motivations for learning physics, organization of scientific knowledge, experiences outside the classroom, and demographics. Using a person-centered approach, we utilize cluster analysis methods to group students into learning profiles based on their individual responses to better understand the strategies and motives of algebra-based studio physics students. Previous studies have identified five distinct learning profiles across several student populations using similar methods. We present results from first-semester and second-semester studio-mode introductory physics courses across three universities. We identify these five distinct learning profiles found in previous studies to be present within our population of introductory physics students. In addition, we investigate interactions between these learning profiles and student demographics. We find significant interactions between a student's learning profile and their experience with high school physics, major, gender, grade expectation, and institution. Ultimately, we aim to use this method of analysis to take the characteristics of students into account in the investigation of successful strategies for using studio methods of physics instruction within and across institutions.

MicroRNA let-7d regulates the TLX/microRNA-9 cascade to control neural cell fate and neurogenesis.

Science.gov (United States)

Zhao, Chunnian; Sun, GuoQiang; Ye, Peng; Li, Shengxiu; Shi, Yanhong

2013-01-01

MicroRNAs have important functions in the nervous system through post-transcriptional regulation of neurogenesis genes. Here we show that microRNA let-7d, which has been implicated in cocaine addiction and other neurological disorders, targets the neural stem cell regulator TLX. Overexpression of let-7d in vivo reduced neural stem cell proliferation and promoted premature neuronal differentiation and migration, a phenotype similar to those induced by TLX knockdown or overexpression of its negatively-regulated target, microRNA-9. We found a let-7d binding sequence in the tlx 3' UTR and demonstrated that let-7d reduced TLX expression levels in neural stem cells, which in turn, up-regulated miR-9 expression. Moreover, co-expression of let-7d and TLX lacking its 3' UTR in vivo restored neural stem cell proliferation and reversed the premature neuronal differentiation and migration. Therefore, manipulating let-7d and its downstream targets could be a novel strategy to unravel neurogenic signaling pathways and identify potential interventions for relevant neurological disorders.

Linear energy transfer (LET) effects in the radiation-induced inactivation of papain

International Nuclear Information System (INIS)

Bisby, R.H.; Cundall, R.B.; Sims, H.E.; Burns, W.G.

1977-01-01

The inactivation of dilute aqueous solutions of papain by radiations of varying linear energy transfer has been studied in N 2 , N 2 0 and O 2 -saturated solutions. The results obtained with low LET radiation are very similar to those previously reported by Lin et al (Radiation Res.;62:438(1975)). The additional data obtained at higher LET, when radical product yields are reduced and the yield of hydrogen peroxide is increased, show that the hydrogen atom is more important in the inactivation of papain than previously considered. (author)

An Approach to Energy Education for High School, Junior High School and Elementary School Students at Aichi Institute of Technology

Science.gov (United States)

Yukita, Kazuto; Ichiyanagi, Katsuhiro; Mori, Tsuyoshi; Goto, Yasuyuki

This paper discusses the methods of implementation and improvement adopted in the energy education program of “Marugoto Taiken World” (“Total Experience World”) at Aichi Institute of Technology. The program, which is aimed at high school, junior high school and elementary school students, has been carried on at Aichi Institute of Technology for a number of years now, and the authors have been involved in the energy education project for the past four years. During that time, the following four courses have been held : 1) Let's use wind power to generate electricity, 2) Let's use flowers to build a solar battery, 3) Let's use bottles to build a fuel cell battery, 4) Let's make all sorts of batteries.

Exploring Lecturers' Views of First-Year Health Science Students' Misconceptions in Biomedical Domains

Science.gov (United States)

Badenhorst, Elmi; Mamede, Sílvia; Hartman, Nadia; Schmidt, Henk G.

2015-01-01

Research has indicated that misconceptions hamper the process of knowledge construction. Misconceptions are defined as persistent ideas not supported by current scientific views. Few studies have explored how misconceptions develop when first year health students conceptually move between anatomy and physiology to construct coherent knowledge…

Taiwanese Medical Students' Narratives of Intercultural Professionalism Dilemmas: Exploring Tensions between Western Medicine and Taiwanese Culture

Science.gov (United States)

Ho, Ming-Jung; Gosselin, Katherine; Chandratilake, Madawa; Monrouxe, Lynn V.; Rees, Charlotte E.

2017-01-01

In an era of globalization, cultural competence is necessary for the provision of quality healthcare. Although this topic has been well explored in non-Western cultures within Western contexts, the authors explore how Taiwanese medical students trained in Western medicine address intercultural professionalism dilemmas related to tensions between…

Exploring the Relationships among Race, Class, Gender, and Middle School Students' Perceptions of School Racial Climate

Science.gov (United States)

Watkins, Natasha D.; Aber, Mark S.

2009-01-01

Although school climate has been thought to be especially important for racial minority and poor students (Booker, 2006; Haynes, Emmons, & Ben-Avie, 1997), little research has explored the significance of racial climate for these students. Furthermore, research in the area has tended to treat race, socioeconomic class, and gender separately,…

Using association rules to explore interdependencies in vacation portfolios and co-variates: the case of students

NARCIS (Netherlands)

Grigolon, A.B.; Kemperman, A.D.A.M.; Timmermans, H.J.P.

2012-01-01

The goal of this paper was to explore the vacation histories of a sample of young adults, mostly students, as part of a larger study on vacation planning of this segment of the population. The student segment represents an interesting and highly relevant subject of study. Over a relative short

Square Pegs, Round Holes: An Exploration of Teaching Methods and Learning Styles of Millennial College Students

Science.gov (United States)

Bailey, Regina M.

2012-01-01

In an information-saturated world, today's college students desire to be engaged both in and out of their college classrooms. This mixed-methods study sought to explore how replacing traditional teaching methods with engaged learning activities affects millennial college student attitudes and perceptions about learning. The sub-questions…

Let's collocate: student generated worksheets as a motivational tool

OpenAIRE

Simpson, Adam John

2006-01-01

This article discusses the process of producing collocation worksheets and the values of these worksheets as a motivational tool within a tertiary level preparatory English program. Firstly, the method by which these worksheets were produced is described, followed by an analysis of their effectiveness as a resource in terms of student motivation, personalisation, involvement in the development of the curriculum and in raising awareness of corpus linguistics and its applications.

Competencies in Education for Sustainable Development: Exploring the Student Teachers’ Views

Directory of Open Access Journals (Sweden)

Gisela Cebrián

2015-03-01

Full Text Available In the context of higher education, over 100 universities have signed international declarations and have committed to embed sustainability within their operations, outreach, education and research. However, despite the declaration of good intentions and policy developments at the national, regional and international level, little has been achieved in terms of embedding education for sustainable development holistically in the curriculum. To date, a number of research studies have focused on the perceptions and views of university students in relation to sustainable development knowledge, skills and competencies; however, few studies have focused on student teachers’ perceptions of education for sustainable development. The aim of this study was to explore the perceptions and views of a group of thirty-two student teachers in relation to education for sustainable development competencies. The research instrument used was a questionnaire. This study provides evidence on the education for sustainable development (ESD competencies that student teachers would prioritize in a school project related to ESD: acquisition of knowledge and practical skills related to nature and natural sciences, to the detriment of other types of learning, such as the promotion of ethical values, positive attitudes towards sustainability and the management of emotions among their future primary school students. Existing ESD theoretical frameworks need to become more alive and integrated within the existing teacher education curriculum to promote the awareness and development of ESD competencies amongst student teachers.

Making connections: Exploring student agency in a science classroom in India

Science.gov (United States)

Sharma, Ajay

India has been a free country for more than half a century now. In this time, the state has succeeded to a large extent in providing universal access to at least elementary education to all the citizens. However, the quality of education provided in state-run schools remains far removed from the ideals endorsed in policy documents. The vast majority of Indian poor, especially in rural areas, depend upon state-run schools for access to education. However, the low quality of education provided in these schools militates against their hopes and efforts for securing a better future through education. Undergirded by concerns over the raw deal students of government run schools get in rural India, this study is an ethnographic exploration of science learning in a rural middle school classroom in India. The study was conducted in the government middle school at the village Rajkheda, in the Hoshangabad district of the state of Madhya Pradesh, India. The study focused on the nature and scope of student participation in a middle school science classroom of rural school in India. Taking a socio-cultural perspective, it explored student participation in science classroom as engagement in a socioculturally mediated dialogue with the natural and the social world. Thus, two parallel yet intersecting themes run through the narrative this study presents. On one hand, it focuses on students' efforts to both learn and survive science as taught in that school. While on the other, it details the nature of their engagement with and knowledge of their immediate material world. The study shows that through active engagement with their local material and social world, students of the 8th grade had acquired an extensive, useful and situated funds of experiential knowledge that enabled them to enact their agency in the material world around them. This knowledge revealed itself differently in different contexts. Their knowledge representations about school science and the material world were

CD95 is part of a let-7/p53/miR-34 regulatory network.

Directory of Open Access Journals (Sweden)

Annika Hau

Full Text Available The death receptor CD95 (APO-1/Fas mediates apoptosis induction upon ligation by its cognate ligand CD95L. Two types of CD95 signaling pathways have been identified, which are characterized by the absence (Type I or presence (Type II of mitochondrial involvement. Micro(miRNAs are small noncoding RNAs that negatively regulate gene expression. They are important regulators of differentiation processes and are found frequently deregulated in many human cancers. We recently showed that Type I cells express less of the differentiation marker miRNA let-7 and, hence, likely represent more advanced tumor cells than the let-7 high expressing Type II cells. We have now identified miR-34a as a selective marker for cells that are sensitive to CD95-mediated apoptosis. Both CD95 and miR-34a are p53 target genes, and consequently, both the sensitivity of cancer cells to CD95-mediated apoptosis and the ability to respond to p53 mediated DNA genotoxic stress are linked. Interestingly, while miR-34a was found to positively correlate with the ability of cells to respond to genotoxic stress, let-7 was negatively correlated. The expression level of CD95 inversely correlated with the expression of let-7 suggesting regulation of let-7 expression by CD95. To test a link between p53 and miR-34a, we altered the expression of CD95. This affected the ability of cells to activate p53 and to regulate miR-34a. Our data point to a novel regulatory network comprising p53, CD95, let-7, and miR-34a that affects cancer cell survival, differentiation, and sensitivity to apoptotic signals. The possible relevance of this regulatory network for cancer stem cells is discussed.

Exploring simple assessment methods for lighting quality with architecture and design students

DEFF Research Database (Denmark)

Madsen, Merete

2006-01-01

that cannot be assessed by simple equations or rules-of-thumb. Balancing the many an often contradictory aspects of energy efficiency and high quality lighting design is a complex undertaking not just for students. The work described in this paper is one result of an academic staff exchange between...... the Schools of Architecture in Copenhagen and Victoria University of Wellington (New Zealand). The authors explore two approaches to teaching students simple assessment methods that can contribute to making more informed decisions about the luminous environment and its quality. One approach deals...... with the assessment of luminance ratios in relation to computer work and presents in that context some results from an experiment undertaken to introduce the concept of luminance ratios and preferred luminance ranges to architeture students. In the other approach a Danish method for assissing the luminance...

Exploring relativity: a workbook for undergraduate students (undergraduate lecture notes in physics)

CERN Document Server

Lorimer, Dunan

2013-01-01

Einstein’s special and general theories of relativity are explored graphically and quantitatively using elementary algebra through a series of fifteen interactive lectures designed for undergraduate physics majors.  Topics covered include:  space-time diagrams, special relativity, the equivalence principle, general relativity, and black holes.  The goal of this book is to provide the student with a sound, conceptual understanding of both the special and the general theories of relativity, so the student will gain insight into how astrophysicists are using these theories to study black holes in the universe.  At the end of each chapter, there is a set of exercises to further facilitate the student’s understanding of the material. The ultimate goal of the book is for students to continue to use it as a preferred reference during and after their undergraduate career.

MicroRNA-let-7a regulates cell autophagy by targeting Rictor in gastric cancer cell lines MGC-803 and SGC-7901.

Science.gov (United States)

Fan, Hao; Jiang, Mingkun; Li, Bowen; He, Yu; Huang, Chi; Luo, Dakui; Xu, Hao; Yang, Li; Zhou, Jundong

2018-03-01

miR-let-7a is the most widely studied miRNA, whose functions have been well-established by scientists in both carcinogenesis and progression of human cancer, including gastric cancer (GC). However, to date there is a lack of information concerning the relationship between miR-let-7a and cellular autophagy. Using western blotting and immunofluorescence, we determined that upregulation of miR-let-7a led to increased cellular autophagic level, whereas miR-let-7a suppression decreased autophagy activity in GC cells. To further elucidate the mechanisms underlying this, we screened potential targets of miR-let-7a using bioinformatics analyses, validated by a series of assays. Our results indicated that Rptor independent companion of mTOR complex 2 (Rictor) was a direct target of miR-let-7a. In addition, rescue experiments in vitro showed that miR-let-7a promoted cellular autophagic level by inhibiting Rictor expression in GC cells. Furthermore, as an upstream executor of Akt-mTOR signaling pathway, we found that Rictor elaborated its effect on autophagy by phosphorylating Akt and mTOR, and this regulatory process could also be mediated by miR-let-7a. Taken together, our results present a novel role for miR-let-7a in GC which modulates autophagy by targeting Rictor, following the regulation of Akt-mTOR signal pathway.

Influence of high- and low-LET radiation on the cardiac differentiation of mouse embryonic stem cells

Energy Technology Data Exchange (ETDEWEB)

Helm, Alexander

2013-07-19

The in utero exposure to ionising radiation poses a risk for the radiosensitive developing embryo. Effects of low-LET radiation on different developmental stages of the embryo are relatively well known due to experimental studies and epidemiological data. Data for effects on the very early stage of the embryonic development, particularly the effects of high-LET radiation instead are rather limited. However, unanticipated exposures of the early embryo to ionising radiation may occur through diagnostic or therapeutic applications or through radiation accidents. Additionally, protons and carbon ions are increasingly used in radiotherapy. Thus, a risk estimation of high-LET exposure especially to the early embryo is of a certain importance. To address this topic, pluripotent mouse embryonic stem cells resembling the blastocyst stage were irradiated with high-LET carbon ions or low-LET X-rays and subsequently differentiated to mimic the early embryonic development. The occurrence of spontaneously contracting cardiomyocytes was used as a marker to asses the radiation effects on the differentiation. Among others, cell inactivation, cell death and gene expression were analysed. A delay in the cardiac differentiation after radiation exposure was found. The results point to radiation-induced cell killing as the main effector of the developmental delay. Carbon ions were found to be more effective than X-rays.

Light-effect transistor (LET) with multiple independent gating controls for optical logic gates and optical amplification

Science.gov (United States)

Marmon, Jason; Rai, Satish; Wang, Kai; Zhou, Weilie; Zhang, Yong

The pathway for CMOS technology beyond the 5-nm technology node remains unclear for both physical and technological reasons. A new transistor paradigm is required. A LET (Marmon et. al., Front. Phys. 2016, 4, No. 8) offers electronic-optical hybridization at the component level, and is capable of continuing Moore's law to the quantum scale. A LET overcomes a FET's fabrication complexity, e.g., physical gate and doping, by employing optical gating and photoconductivity, while multiple independent, optical gates readily realize unique functionalities. We report LET device characteristics and novel digital and analog applications, such as optical logic gates and optical amplification. Prototype CdSe-nanowire-based LETs, incorporating an M-S-M structure, show output and transfer characteristics resembling advanced FETs, e.g., on/off ratios up to 106 with a source-drain voltage of 1.43V, gate-power of 260nW, and a subthreshold swing of 0.3nW/decade (excluding losses). A LET has potential for high-switching (THz) speeds and extremely low-switching energies (aJ) in the ballistic transport region. Our work offers new electronic-optical integration strategies for high speed and low energy computing approaches, which could potentially be extended to other materials and devices.

Multilevel Analysis Exploring the Links between Stress, Depression, and Sleep Problems among Two-Year College Students

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Wallace, Deshira D.; Boynton, Marcella H.; Lytle, Leslie A.

2017-01-01

Objective: This study explored the association of stress and depression with a multidimensional sleep problems construct in a sample of 2-year college students. Participants: The sample consisted of 440 students enrolled in 2-year study from Fall 2011 to Fall 2013. Methods: Participants in an obesity prevention study completed surveys assessing…

Decreased expression of microRNA let-7i and its association with chemotherapeutic response in human gastric cancer

Directory of Open Access Journals (Sweden)

Liu Kun

2012-10-01

Full Text Available Abstract Background MicroRNA let-7i has been proven to be down-regulated in many human malignancies and correlated with tumor progression and anticancer drug resistance. Our study aims to characterize the contribution of miRNA let-7i to the initiation and malignant progression of locally advanced gastric cancer (LAGC, and evaluate its possible value in neoadjuvant chemotherapeutic efficacy prediction. Methods Eighty-six previously untreated LAGC patients who underwent preoperative chemotherapy and radical resection were included in our study. Let-7i expression was examined for pairs of cancer tissues and corresponding normal adjacent tissues (NATs, using quantitative RT-PCR. The relationship of let-7i level to clinicopathological characteristics, pathologic tumor regression grades after chemotherapy, and overall survival (OS was also investigated. Results Let-7i was significantly down-regulated in most tumor tissues (78/86: 91% compared with paired NATs (P P =0.024 independently of other clinicopathological factors, including tumor node metastasis (TNM stage (HR = 3.226, P = 0.013, depth of infiltration (HR = 4.167, P P = 0.037. Conclusions These findings indicate that let-7i may be a good candidate for use a therapeutic target and a potential tissue marker for the prediction of chemotherapeutic sensitivity and prognosis in LAGC patients.

Protein-directed modulation of high-LET hyperthermic radiosensitization

International Nuclear Information System (INIS)

Chang, P.Y.

1991-01-01

A pair of Chinese Hamster Ovary cell lines, the wild-type CHO-SC1, and its temperature-sensitive mutant (CHO-tsH1) was used to examine the importance of protein synthesis in the development of thermotolerance. The classical biphasic thermotolerant survival response to hyperthermia was observed in the SC1 cells after continuous heating at 41.5C to 42.5C, while tsH1 showed no thermotolerance. In separate experiments, each cell line was triggered and challenged at 45C. The heat doses were separated with graded incubaton periods at 35C or 40C for thermotolerance development. SC1 cells expressed thermoresistance, with the synthesis of heat shock proteins, under both incubation conditions. tsH1 cells expressed thermotolerance similar to that seen in the SC1 cells when incubated at 35C, but the survival response with the non-permissive 40C incubation was much reduced in the absence of protein synthesis. The combined effects of heavy-ion radiation and hyperthermia were examined using the same cell system. A mild heat dose of 41.5C was used in conjunction with Neon particle radiation of various high LET values. The cell killing effects were highly dependent on the sequence of application of heat and Neon radiation. Heat applied immediately after Neon irradiation was more cytotoxic to SC1 cells than when heat was applied prior to the irradiation. The ability of cells to synthesize new proteins plays a key role in this sequence-dependent thermal radiosensitization. In the absence of protein synthesis in the tsH1 cells, the high-LET thermal enhancement for cell-killing was unchanged regardless of the sequence. In the presence of protein synthetic activity in the SC1 cells, the thermal enhancement of radiation-induced cell killing was LET-dependent

Operation of a hemispherical detector for LET measurements

International Nuclear Information System (INIS)

Schell, M.C.; DeLuca, P.M. Jr.; Pearson, D.W.

1982-01-01

A hemispherical ΔE/E detector has been constructed and tested for the measurement of linear-energy-transfer distributions of charged particles induced by fast neutrons. The initial performance test results and LET distributions from 14.8-MeV monoenergetic neutron irradiation in free space of carbon, lead, and Al50-plastic are presented

LET dependence of the production of oxidative DNA damage in mammalian cells

International Nuclear Information System (INIS)

Ito, Atsushi; Furuichi, Wataru; Inoguchi, Hiroki; Hirayama, Ryoichi; Murayama, Chieko; Furusawa, Yoshiya

2006-01-01

Production of 8-hydroxy-2'-deoxyguanosine (8-OHdG) in human leukemia HL-60 cells was examined upon irradiation with carbon, neon silicon ions. Cell suspension with the concentration of 1 x 10 7 /ml was irradiated tinder air-saturated condition. After irradiation cells were subjected to the DNA extraction using isopropanol, separation of DNA strands by heat treatment, digestion into nucleosides with nuclease P1 and alkaline phosphatase. A single peak of 8-OHdG on a chromatogram was observed using newly installed ECD detector (Coulochem III; ESA, Inc. U.S.A.). Reproducibility was also greatly improved with this detector. 8-OHdG yield was decreased with increasing linear energy transfer (LET) for carbon and silicon beam. These results are in good accordance with those of dG solution which was previously reported by us. Ion species dependence in 8-OHdG yield was not so apparent through the comparison of carbon and neon beam with an LET of 80 keV/μm and neon and silicon beam with an LET of 150 keV/μm. (author)

Student Engagement in the Caribbean Region: Exploring Its Role in the Motivation and Achievement of Jamaican Middle School Students

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Martin, Tamica G.; Martin, Andrew J.; Evans, Paul

2017-01-01

Using an expectancy-value framework, the present investigation is the first to explore the generality of this theorizing and research in the emerging regional context of the Caribbean. Given high underachievement in the Caribbean region, we addressed the need to better understand the role of engagement in students' academic motivation and…

c-Myc Represses Tumor-Suppressive microRNAs, let-7a, miR-16 and miR-29b, and Induces Cyclin D2-Mediated Cell Proliferation in Ewing's Sarcoma Cell Line.

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Masanori Kawano

Full Text Available Myc oncogenic transcription factor is known to inhibit tumor suppressive microRNAs (miRNAs, resulting in greater expression of their target protein related to cell cycle, invasion or anti-apoptotic factors in human cancer cells. To explore possible oncogenic factors in Ewing's sarcoma (ES, we conducted microarray-based approach to profile the changes in the expression of miRNAs and its downstream mRNAs in five ES cell lines and human mesenchymal stem cells (hMSCs. Three miRNAs, let-7a, miR-16 and miR-29b were significantly down-regulated, whereas c-Myc and cyclin D2 (CCND2 were significantly up-regulated in all tested ES cells compared with hMSCs. To verify that let-7a, miR-16 and miR-29b were the targets of c-Myc in ES cell lines, we transfected siRNA against c-Myc and confirmed the coordinate up-regulation of let-7a, miR-16 and miR-29b through the repression of c-Myc. The ES cells transfected with c-Myc-siRNA and let-7a, miR-16 and miR-29b exhibited the inhibition of the cell cycle progression. The increased expression of let-7a, miR-16 and miR-29b resulted in the reduction of CCND2 protein expression. We also demonstrated that c-Myc-siRNA treatment of ES cells was associated with the decreased expression of CCND2 as a down-stream of three miRNAs. Furthermore, the introduction of let-7a, miR-16 and miR-29b in ES cells could inhibit the c-Myc-mediated up-regulation of CCND2 resulted in the prevention of cell cycle progression. In addition, the transfection of let-7a, miR-16 and miR-29b in ES cells suppressed tumor growth ex vivo treatment. These findings suggests that the up-regulation of c-Myc inhibited the expression of let-7a, miR-16 and miR-29b subsequently induced CCND2 expression in ES cells. The present study might identify a novel oncogenic axis that c-Myc regulates the expression of CCND2 via let-7a, miR-16 and miR-29b, leading to the development new therapeutic targets for ES.

Quartet cards as the media of career exploration for lower-grade primary school students

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Yulia Ayriza

2017-12-01

Full Text Available A career developed through the optimization of one’s potentials will irrevocably play a role in the development of self-identity as well as the psychological well-being of the individual. When children are introduced and allowed to explore as many career options as possible during their developmental stage, they are more likely to have a fruitful career development in the future. The preceding study showed that the career interests and knowledge of lower-grade primary students fit the Holland Career Categories: realistic, investigative, artistic, social, enterprising, and conventional (RIASEC. It was also found that the students’ career interest and knowledge levels varied, with most in the low level. This second-year study aims to expand the results of the previous study by developing the use of Quartet cards as the media of career exploration for lower-grade primary students. By using the research and development method, this study develops Quartet Career Cards into three difficulty levels: low, medium, and high. The Quartet cards media have undergone feasibility tests conducted by experts in theory and media, as well as a series of field testing consisting of preliminary, main, and operational stages among a total of 266 primary students of grades 1, 2, and 3. A revision was made on several components including the images, information, colors, font sizes, illustration styles, and card sizes. The findings show that Quartet Career Cards meet the feasibility standards for the media of career exploration

Exploring Factors That Promote Online Learning Experiences and Academic Self-Concept of Minority High School Students

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Kumi-Yeboah, Alex; Dogbey, James; Yuan, Guangji

2018-01-01

The rapid growth of online education at the K-12 level in recent years presents the need to explore issues that influence the academic experiences of students choosing this method of learning. In this study, we examined factors that promote/hinder the learning experiences and academic self-concept of minority students attending an online high…

An Exploration of the Readiness, Challenges and Expected Support for Their Overseas Study of Chinese Business and Management Programme Students

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Wang, Chengbo; Li, Xiaomei; Ou, Xuan; O'Kane, James; Mao, Zhaofang; Zhang, Wenquan

2015-01-01

Chinese students are the largest international student cohort in the higher education institutions of English-speaking developed countries. The paper explores strategies to enhance the Chinese students' learning efficacy in overseas institutions. This research differs from other research focusing on international students already in…

Psychological Attributes in Foreign Language Reading: An Explorative Study of Japanese College Students

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Mikami, Hitoshi; Leung, Chi Yui; Yoshikawa, Lisa

2016-01-01

This study explores the internal structure of psychological attributes (i.e., motivation, belief and emotion) related to foreign language reading (FLR) (hereafter FLR attributes) and checks the utility of existing FLR attribute measurements for the specific learner group (i.e., Japanese university students studying English as their foreign…

Exploring Attitude Transformation: A Grounded Theory Study of Romanian Teachers of Roma Students

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Jones, Laura Estella

2016-01-01

The purpose of this systematic grounded theory study was to explore the process of change in teacher attitudes toward including Roma ("Gypsy") students in non-segregated schools in Romania. The theories guiding this study included Mezirow's (1991, 2000) theory of transformation, Gay's (2002, 2013) theory of culturally responsive…

Exploring Students' Computational Thinking Skills in Modeling and Simulation Projects: : A Pilot Study

NARCIS (Netherlands)

Grgurina, Natasa; van Veen, Klaas; Barendsen, Erik; Zwaneveld, Bert; Suhre, Cor; Gal-Ezer, Judith; Sentance, Sue; Vahrenhold, Jan

2015-01-01

Computational Thinking (CT) is gaining a lot of attention in education. We explored how to discern the occurrences of CT in the projects of 12th grade high school students in the computer science (CS) course. Within the projects, they constructed models and ran simulations of phenomena from other

A preliminary study on action mechanisms of surviving expression in cell apoptosis induced by high-LET radiation

International Nuclear Information System (INIS)

Jin Xiaodong; Li Qiang; Gong Li; Wu Qingfeng; Li Ping; Dai Zhongying; Liu Xinguo; Tao Jiajun

2010-01-01

It has been proven that over-expression of surviving in cancerous cell lines is related to the radioresistance of cells to high-LET radiation in previous work. In this study, action mechanisms of surviving gene in apoptosis induced by high-LET radiation were investigated. We found that inhibiting surviving by siRNA had no notable influence on Bcl-2 and Bax expressions induced by carbon ions. Surviving depressed cell apoptosis through the inhibition of the activities of caspase-3 and -9 possibly in cell apoptosis induced by high-LET radiation. (authors)

Typing Compared with Handwriting for Essay Examinations at University: Letting the Students Choose

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Mogey, Nora; Paterson, Jessie; Burk, John; Purcell, Michael

2010-01-01

Students at the University of Edinburgh do almost all their work on computers, but at the end of the semester they are examined by handwritten essays. Intuitively it would be appealing to allow students the choice of handwriting or typing, but this raises a concern that perhaps this might not be "fair"--that the choice a student makes,…

Human Anatomy: Let the Students Tell Us How to Teach

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Davis, Christopher R.; Bates, Anthony S.; Ellis, Harold; Roberts, Alice M.

2014-01-01

Anatomy teaching methods have evolved as the medical undergraduate curriculum has modernized. Traditional teaching methods of dissection, prosection, tutorials and lectures are now supplemented by anatomical models and e-learning. Despite these changes, the preferences of medical students and anatomy faculty towards both traditional and…

Away from Home: A Qualitative Exploration of Health Experiences of Nigerian Students in a U.K. University

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Alloh, Folashade T.; Tait, Desiree; Taylor, Clare

2018-01-01

This study explored the factors that contribute to the health experience of Nigerian students in the United Kingdom. Challenges faced by international students include dietary issues, isolation, stress, depression, and others. Nine semi-structured interviews were conducted combination of purposive sampling and snowball sampling techniques were…

"Forbidden Narratives": Exploring the Use of Student Narratives of Self in a Graduate Sport Sociology Course

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Liberti, Rita

2004-01-01

This essay highlights three graduate student papers in an effort to explore the use of a relatively new methodology in the social sciences known as narratives of self. The seminar, in which the student papers were written, was formulated on the tenets of critical pedagogy and cultural studies. This paper positions the use of narratives of self…

Production of perhydroxy radical (HO2) and oxygen in the radiolysis of aqueous solution and the LET effects

International Nuclear Information System (INIS)

Imamura, Masashi

1987-01-01

This article aims to review the results concerning the production of perhydroxy radical (HO 2 ) and oxygen from irradiated aqueous solutions and the LET effects on these products, beginning with a brief introduction to the elementary primary processes in radiolysis of aqueous solution. Oxygen, if produced in the radiolysis of aqueous solution, may be considered responsible for the decreased oxygen enhancement ratio (OER) in biological systems exposed to high LET radiation. A Harwell's group has determined oxygen generated from aqueous ferrous solutions irradiated with heavy ions and concluded that the oxygen is a precursor of perhydroxy radicals. The LET-dependent yields for perhydroxy radical have been determined by LaVerne and Schuler; the analysis of their results sheds light into the reactions taking place in high-LET track cores. In conjunction with these results, the possible contributions to the LET effects are pointed out and discussed of the energetic secondary electrons ejected from the track core by knock-on collision with heavy ions and of the variation in the track core size with energy of the heavy particles. (author)

LET dependency of heavy-ion induced apoptosis in V79 cells

International Nuclear Information System (INIS)

Aoki, Mizuho; Furusawa, Yoshiya; Yamada, Takeshi

2000-01-01

We investigated the relationship between the LET values and cell death, defined as either apoptosis or loss of reproductive integrity (reproductive death), using Chinese hamster V79 cells. The cells were irradiated with X-rays or carbon-ion beams from the Heavy Ion Medical Accelerator in Chiba (HIMAC) at the National Institute of Radiological Sciences (NIRS). Apoptosis was defined based on the morphological change upon treating of cells with caffeine. The apoptotic index, the ratio of apoptotic cells to the total, after exposure to 2 Gy of X-rays was 0.043. Upon irradiation with carbon-ion beams, the index was gradually increased with increasing LET values, reaching a maximum of 0.076 at 110 keV/μm, and then decreased to 0.054 at 237 keV/μm. An analogous pattern of the LET dependence was observed between reproductive death and apoptotic death. The cell-survival values obtained after 2 Gy exposure (SF 2 ) were 0.64, 0.13, and 0.24, respectively. A similar trend was found for the RBE values calculated from the initial slope for both apoptosis and reproductive death. These results strongly suggest that the target for both types of cell death is the same. (author)

Developing Curriculum to Help Students Explore the Geosciences' Cultural Relevance

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Miller, G.; Schoof, J. T.; Therrell, M. D.

2011-12-01

Even though climate change and an unhealthy environment have a disproportionate affect on persons of color, there is a poor record of diversity in geoscience-related fields where researchers are investigating ways to improve the quality of the environment and human health. This low percentage of representation in the geosciences is equally troubling at the university where we are beginning the third and final year of a project funded through the National Science Foundation's (NSF) Opportunities to Enhance Diversity in the Geosciences (OEDG). The purpose of this project is to explore a novel approach to using the social sciences to help students, specifically underrepresented minorities, discover the geosciences' cultural relevance and consider a career in the earth, atmospheric, and ocean sciences. To date, over 800 college freshmen have participated in a design study to evaluate the curriculum efficacy of a geoscience reader. Over half of these participants are students of color. The reader we designed allows students to analyze multiple, and sometimes conflicting, sources such as peer-reviewed journal articles, political cartoons, and newspaper articles. The topic for investigation in the reader is the 1995 Chicago Heat Wave, a tragic event that killed over 700 residents. Students use this reader in a core university course required for entering freshmen with low reading comprehension scores on standardized tests. To support students' comprehension, evaluation, and corroboration of these sources, we incorporated instructional supports aligned with the principles of Universal Design for Learning (UDL), reciprocal teaching, historical reasoning, media literacy, and quantitative reasoning. Using a digital format allows students to access multiple versions of the sources they are analyzing and definitions of challenging vocabulary and scientific concepts. Qualitative and quantitative data collected from participating students and their instructors included focus

Calculated LET spectrum from antiproton beams stopping in water

CERN Document Server

Bassler, Niels

2009-01-01

Antiprotons have been proposed as a potential modality for radiotherapy because the annihilation at the end of range leads to roughly a doubling of physical dose in the Bragg peak region. So far it has been anticipated that the radiobiology of antiproton beams is similar to that of protons in the entry region of the beam, but very different in the annihilation region, due to the expected high-LET components resulting from the annihilation. On closer inspection we find that calculations of dose averaged LET in the entry region may suggest that the RBE of antiprotons in the plateau region could significantly differ from unity, which seems to warrant closer inspection of the radiobiology in this region. Materials and Methods. Monte Carlo simulations using FLUKA were performed for calculating the entire particle spectrum of a beam of 126 MeV antiprotons hitting a water phantom. Results and Discussion. In the plateau region of the simulated antiproton beam we observe a dose-averaged unrestrict...

Exploring the Work/Life/Study Balance: The Experience of Higher Education Students in a Scottish Further Education College

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Lowe, Janet; Gayle, Vernon

2007-01-01

This study explores the dimensions of the work/life/study balance and its influence on student participation in higher education, through a case study of the experience of higher education students, studying both full time and part time, in a Scottish further education college. The experience of the students and the work/life/study challenges that…

Let's Write It Right! A Student-Oriented Approach for Teaching Letterwriting Skills.

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Christensen, Judie

In the student-oriented approach to writing business letters, students work in small groups to write a series of letters. For the first letter, the groups take the role of consumers, writing letters to order merchandise. The letters are written on overhead transparencies and are then critiqued by the other teams, with an emphasis on constructive…

Enough about You, Let's Talk about Me: Student Voice in the Classroom

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Mee, Molly

2007-01-01

Many middle school students claim that their voices are ignored in the classroom, where the attitude is too often that the teacher holds the one right answer. Instead of this approach, teachers may wish to use the Socratic Seminar, which prompts students to examine issues and ideas through dialogue and actively involves and motivates them, giving…

miRNA let-7b modulates macrophage polarization and enhances tumor-associated macrophages to promote angiogenesis and mobility in prostate cancer.

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Wang, Zhigang; Xu, Lu; Hu, Yinying; Huang, Yanqin; Zhang, Yujuan; Zheng, Xiufen; Wang, Shanshan; Wang, Yifan; Yu, Yanrong; Zhang, Meng; Yuan, Keng; Min, Weiping

2016-05-09

Macrophage polarization is a highly plastic physiological process that responds to a variety of environmental factors by changing macrophage phenotype and function. Tumor-associated macrophages (TAMs) are generally recognized as promoting tumor progression. As universal regulators, microRNAs (miRNAs) are functionally involved in numerous critical cellular processes including macrophage polarization. Let-7b, a miRNA, has differential expression patterns in inflamed tissues compared with healthy controls. However, whether and how miRNA let-7b regulates macrophage phenotype and function is unclear. In this report, we find that up-regulation of let-7b is characteristic of prostatic TAMs, and down-regulation of let-7b in TAMs leads to changes in expression profiles of inflammatory cytokines, such as IL-12, IL-23, IL-10 and TNF-α. As a result, TAMs treated with let-7b inhibitors reduce angiogenesis and prostate carcinoma (PCa) cell mobility. Let-7b may play a vital role in regulating macrophage polarization, thus modulating the prognosis of prostate cancer.

From Phenotype to Genotype: Exploring Middle School Students' Understanding of Genetic Inheritance in a Web-Based Environment

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Williams, Michelle; Montgomery, Beronda L.; Manokore, Viola

2012-01-01

Research shows that students face challenges as they learn about genetic inheritance. The challenges could emanate from the fact that genetic inheritance involves unseen processes at different organizational levels. We explored students' understanding of heredity and related concepts such as cells and reproduction using a Web-based Science Inquiry…

An Exploration of Support Factors Available to Higher Education Students with High Functioning Autism or Asperger Syndrome

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Rutherford, Emily N.

2013-01-01

This qualitative phenomenological research study used narrative inquiry to explore the support factors available to students with High Functioning Autism or Asperger Syndrome in higher education that contribute to their success as perceived by the students. Creswell's (2009) six step method for analyzing phenomenological studies was used to…

Overexpression of let-7a increases neurotoxicity in a PC12 cell model of Alzheimer's disease via regulating autophagy.

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Gu, Huizi; Li, Lan; Cui, Chen; Zhao, Zihui; Song, Guijun

2017-10-01

Increased deposition of β-amyloid (Aβ) protein is one of the typical characteristics of Alzheimer's disease (AD). Recent evidence has demonstrated that the microRNA let-7 family, which is highly expressed in the central nervous system, participates in the regulation of pathologic processes of AD. In the present study, the effect of let-7a overexpression on Aβ1-40-induced neurotoxicity was evaluated in PC12 and SK-N-SH cells. The results indicated that overexpression of let-7a enhanced the neurotoxicity induced by Aβ1-40 in PC12 and SK-N-SH cells. In addition, the apoptosis induced by Aβ1-40 in PC12 and SK-N-SH cells was increased by let-7a overexpression. Furthermore, Aβ1-40 treatment increased the protein levels of microtubule-associated protein 1A/1B-light chain 3 (LC3) and beclin-1 and increased the LC3 II/I ratio. The mRNA expression levels of beclin-1, autophagy protein 5 (Atg-5) and Atg-7 were also increased by Aβ1-40 treatment in PC12 cells. Let-7a overexpression further upregulated the above autophagy-related markers. Furthermore, the protein level of p62 was increased by Aβ1-40 treatment, and this was further enhanced by let-7a overexpression. Finally, the present results demonstrated that the phosphoinositide-3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) signaling pathway was involved in the autophagy regulation by let-7a. In conclusion, the present study demonstrates that the neurotoxicity induced by Aβ1-40 is augmented by let-7a overexpression via regulation of autophagy, and the PI3K/Akt/mTOR signaling pathway also serves a function in this process.

Exploring the Effects of Active Learning on High School Students' Outcomes and Teachers' Perceptions of Biotechnology and Genetics Instruction

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Mueller, Ashley L.; Knobloch, Neil A.; Orvis, Kathryn S.

2015-01-01

Active learning can engage high school students to learn science, yet there is limited understanding if active learning can help students learn challenging science concepts such as genetics and biotechnology. This quasi-experimental study explored the effects of active learning compared to passive learning regarding high school students'…

Student Voice Initiative: Exploring Implementation Strategies

Science.gov (United States)

Alexander, Blaine G.

2017-01-01

Student voice is the process of allowing students to work collaboratively with adults to produce a learning culture that is conducive for optimum growth in every student. In a traditional setting, the adults make the decisions and the students are passive observers in the learning process. Data has shown that this traditional culture is not…

Teaching and Learning Science through Song: Exploring the Experiences of Students and Teachers

Science.gov (United States)

Governor, Donna; Hall, Jori; Jackson, David

2013-01-01

This qualitative, multi-case study explored the use of science-content music for teaching and learning in six middle school science classrooms. The researcher sought to understand how teachers made use of content-rich songs for teaching science, how they impacted student engagement and learning, and what the experiences of these teachers and…

Sci-Sat AM: Radiation Dosimetry and Practical Therapy Solutions - 10: Towards LET detection: A study on the effects of scintillator doping

Energy Technology Data Exchange (ETDEWEB)

Nusrat, Humza; Pang, Geordi; Ahmad, Syed; Keller, Brian; Sarfehnia, Arman [Ryerson University, Sunnybrook Health Sciences Centre (Canada)

2016-08-15

Purpose: In radiotherapy, the amount of radiation delivered is determined by optimizing the amount of absorbed dose to the tumor. Dose does not always correlate well with the actual biological effects of radiation. This work seeks to validate the LET-dependence of doped plastic scintillators for use in a radiation beam quality (LET) detector. Methods: The LET spectrum ([Φ]) can be resolved knowing the measured signals of uniquely LET-dependent detectors, [S], and the response of each LET-dependent detector to specific LETs ([R]), through the relation [Φ]=[S][R]{sup −1}. Plastic scintillator response is intrinsically LET dependent and can be varied via doping. Initial prototype consists of plastic scintillator and glass taper coupled to an optical fiber; components are housed in black acrylic, reducing effect of ambient light. In order to determine [R], the light response matrix, GEANT4.10.1 Monte Carlo (MC) was used. To validate MC, measurements were done using high energy electrons (9,12,15MeV) and orthovoltage x-rays (100,250kV); scintillator signal was normalized to dose measured simultaneously. Results: Stopping power was varied by changing particle type/energy; measurements indicated that as stopping power increased from 1.9 to 6.6MeV/cm, detector response increased by 263% (+/−29.2%) for 5%Pb-doped scintillator (155% in MC); 52% (+/−7.8%) increase observed when undoped scintillator was used (49% in MC). 5%Pb-doped discrepancy (100kV x-rays) is being investigated. Conclusions: This work validates that doping effects LET/energy response of scintillators; an effect that can be utilized for construction of an LET detector.

Production and excision of thymine damage in the DNA of mammalian cells exposed to high-LET radiations

International Nuclear Information System (INIS)

Mattern, M.R.; Welch, G.P.

1979-01-01

HeLa S3 and Chinese hamster ovary cells were irradiated with high doses of carbon ions having linear energy transfers (LETs) of 170 and 780 keV/μm. The DNA was analyzed for 5,6-dihydroxydihydrothymine (t'-type) radiation products both before and after postirradiation incubation at 37 0 C. In HeLa cells, 2.1 x 10 -5 ring-damaged thymines were produced per kilorad per 10 6 daltons after irradiation with high-LET carbon ions - approximately one-fifth the efficiency of t' formation in HeLa cells exposed to low-LET x rays. t' products were also formed less efficiently in Chinese hamster ovary cells exposed to carbon ions than in those exposed to x rays. In both cell lines, up to 80% of the t' formed initially was excised selectively from the DNA during 60 min of postirradiation incubation at 37 0 C. Product excision was accompanied by small amounts of DNA degradation (less than 1%). Radiation with LET of 170 keV/μm - nearly the most effective LET for cell killing and the generation of unrejoined DNA strand breaks - produced ring-damaged thymines that were removed selectively from the DNA. This result is consistent with the conclusion that t'-type products do not contribute substantially to lethality after high-LET irradiation, although the alternative possibilities remain that t' is not excised as efficiently after biological doses, or that a particular subclass of t' or defective postexcision events contribute to cell killing

Peer learning partnerships: exploring the experience of pre-registration nursing students.

Science.gov (United States)

Christiansen, Angela; Bell, Amelia

2010-03-01

This paper explores the impact of a peer learning initiative developed to facilitate, purposefully, mutually supportive learning relationships between student nurses in the practice setting. Finding effective strategies to support learning in the practice setting has been the focus of professional concern for a considerable time. In the UK clinical mentorship is seen as pivotal to ensuring fitness to practice; however, recent debate on the nature of learning has revealed the clinical workplace as a rich learning environment where learning occurs not only through hierarchical relationships, but also from a network of peer relationships. Formalising peer relationships through peer assisted learning is increasingly suggested as a strategy to support workplace learning and support novice students' transition to the clinical setting. Despite the developing literature in this field there is limited understanding about how students experience facilitated peer relationships. An interpretive qualitative design. Focus group interviews were used to collect interactive and situated discourse from nursing students who had recently participated in peer learning partnerships (n = 54). Narrative data were analysed thematically. Findings suggest that active support from a fellow student reduced the feelings of social isolation experienced by novice students in initial clinical placements, helping them to deal more effectively with the challenges faced and reducing the factors that have an impact on attrition. In addition, the reciprocity of the peer learning partnerships facilitated understanding of mentorship and created a heightened sense of readiness for registration and professional practice. Peer learning partnerships facilitated by mentors in clinical practice can support the transition to nursing for first year students and can help more experienced students gain a confidence and a heightened readiness for mentorship and registered practice. Facilitated peer learning

Let??s teach geometry

OpenAIRE

Ca??adas, Mar??a C.; Molina, Marta; Gallardo, Sandra; Mart??nez-Santaolalla, Manuel J.; Pe??as, Mar??a

2010-01-01

In this work we present an activity for High School students in which various mathematical concepts of plane and spatial geometry are involved. The final objective of the proposed tasks is constructing a particular polyhedron, the cube, by using a modality of origami called modular origami.

Learning strategies of public health nursing students: conquering operational space.

Science.gov (United States)

Hjälmhult, Esther

2009-11-01

To develop understanding of how public health nursing students learn in clinical practice and explore the main concern for the students and how they acted to resolve this main concern. How professionals perform their work directly affects individuals, but knowledge is lacking in understanding how learning is connected to clinical practice in public health nursing and in other professions. Grounded theory. Grounded theory was used in gathering and analysing data from 55 interviews and 108 weekly reports. The participants were 21 registered nurses who were public health nursing students. The grounded theory of conquering operational space explains how the students work to resolve their main concern. A social process with three identified phases, positioning, involving and integrating, was generated from analysing the data. Their subcategories and dimensions are related to the student role, relations with a supervisor, student activity and the consequences of each phase. Public health nursing students had to work towards gaining independence, often working against 'the system' and managing the tension by taking a risk. Many of them lost, changed and expanded their professional identity during practical placements. Public health nursing students' learning processes in clinical training are complex and dynamic and the theory of 'Conquering operational space' can assist supervisors in further developing their role in relation to guiding students in practice. Relationships are one key to opening or closing access to situations of learning and directly affect the students' achievement of mastering. The findings are pertinent to supervisors and educators as they prepare students for practice. Good relationships are elementary and supervisors can support students in conquering the field by letting students obtain operational space and gain independence. This may create a dialectical process that drives learning forward.

Low LET radiation-induced telomerase catalytic subunit promoter activation is mediated by nuclear factor Kappa B

International Nuclear Information System (INIS)

Natarajan, M.; Hong, F.A.; Mohan, S.; Herman, T.S.

2003-01-01

Full text: The objective of this study is to understand whether low doses of low LET radiation induces survival advantage in normal cells. As an increase in telomerase activity is associated with longevity and cell proliferation, we examined the telomerase response following gamma-irradiation in normal aortic endothelial cells. Telomeric Repeat Amplification Protocol assay following low LET radiation showed an increase in telomerase enzyme activity as early as 8 h post irradiation and reaches its maximum at 24 h. Subsequent analysis revealed that the increased telomerse enzyme activity is due to increased synthesis resulting from an increased transcription. Examination of transcriptional activation of telomerase reverse transcriptase (TERT) promoter regulation showed an enhanced transcription of the telomerse gene following gamma-irradiation. In our previous reports we documented an increase in NF-kB DNA-binding property following low LET radiation (3). Therefore, to determine whether the activation of NF-kB-signaling is responsible for induced TERT promoter activation, cells transiently transfected with minimal promoter region of TERT containing wild type or mutant NF-kB binding site were examined following low LET radiation. TERT promoter activation was induced in wild type transfected cells whereas, in mutant kB binding site, the activation remained at the basal level similar to that of un-irradiated cells. More significantly, the gamma-ray mediated promoter activation of telomerase gene as well as induce telomerase enzyme activity was abrogated by ectopically expressing the IkBa mutant (IkBa (S32A/S36A)), which blocks NF-kB activation. The results thus suggest that exposure to low LET radiation could induce telomerase activity and the activation is at least, in part, mediated by the transcription factor NF-kB. Sustained activation of telomerase in these cells after low LET radiation may impart extended life span

Photon-Fluence-Weighted let for Radiation Fields Subjected to Epidemiological Studies.

Science.gov (United States)

Sasaki, Michiya

2017-08-01

In order to estimate the uncertainty of the radiation risk associated with the photon energy in epidemiological studies, photon-fluence-weighted LET values were quantified for photon radiation fields with the target organs and irradiation conditions taken into consideration. The photon fluences giving a unit absorbed dose to the target organ were estimated by using photon energy spectra together with the dose conversion coefficients given in ICRP Publication 116 for the target organs of the colon, bone marrow, stomach, lung, skin and breast with three irradiation geometries. As a result, it was demonstrated that the weighted LET values did not show a clear difference among the photon radiation fields subjected to epidemiological studies, regardless of the target organ and the irradiation geometry.

Teaching the Thrill of Discovery: Student Exploration of Ultra-Faint Dwarf Galaxies with the NOAO Data Lab

Science.gov (United States)

Olsen, Knut; Walker, Constance E.; Smith, Blake; NOAO Data Lab Team

2018-01-01

We describe an activity aimed at teaching students how ultra-faint Milky Way dwarf galaxies are typically discovered: through filtering of optical photometric catalogs and cross-examination with deep images. The activity, which was developed as part of the Teen Astronomy Café program (https://teensciencecafe.org/cafes/az-teen-astronomy-cafe-tucson/), uses the NOAO Data Lab (http://datalab.noao.edu) and other professional-grade tools to lead high school students through exploration of the object catalog and images from the Survey of the Magellanic Stellar History (SMASH). The students are taught how to use images and color-magnitude diagrams to analyze and interpret stellar populations of increasing complexity, including those of star clusters and the Magellanic Clouds, and culminating with the discovery of the Hydra II ultra-faint dwarf galaxy. The tools and datasets presented allow the students to explore and discover other known stellar systems, as well as unknown candidate star clusters and dwarf galaxies. The ultimate goal of the activity is to give students insight into the methods of modern astronomical research and to allow them to participate in the thrill of discovery.

Exploring the use of student perspectives to inform topics in teacher education

Directory of Open Access Journals (Sweden)

Katy Arnett

2008-04-01

Full Text Available Abstract As FSL teacher educators look to respond to teachers’ concerns about the increasingly diverse student population in K-12 settings, empirical research may not always hold the answers—simply because there has not been much research on the topic. In an attempt to at least identify issues worthy of such empirical consideration and discussion within teacher education programs, this article explores the views of seven Grade 8 core French students who were members of an effective inclusive classroom. Drawing on the individual and focus group interview data from a larger case study of their teacher’s classroom, this article will identify two key themes that the students described as instrumental in the teacher’s attempts to be an effective, inclusive core French teacher. It is the goal of this article that these themes will help inform the decisions FSL teacher educators make about this topic within their programs.

Exploring the Etiology of Ethnic Self-Hatred: Internalized Racism in Chicana/o and Latina/o College Students

Science.gov (United States)

Hipolito-Delgado, Carlos P.

2010-01-01

Internalized racism is rarely discussed in student affairs. Despite the negative effects of internalized racism on the mental health and identity development of college students of color, little is known about its etiology. Based on theoretical conceptions, the author explores if perceived racism and/or U.S. acculturation act as predictors of…

Affirming independence: Exploring mechanisms underlying a values affirmation intervention for first-generation students.

Science.gov (United States)

Tibbetts, Yoi; Harackiewicz, Judith M; Canning, Elizabeth A; Boston, Jilana S; Priniski, Stacy J; Hyde, Janet S

2016-05-01

First-generation college students (students for whom neither parent has a 4-year college degree) earn lower grades and worry more about whether they belong in college, compared with continuing-generation students (who have at least 1 parent with a 4-year college degree). We conducted a longitudinal follow-up of participants from a study in which a values-affirmation intervention improved performance in a biology course for first-generation college students, and found that the treatment effect on grades persisted 3 years later. First-generation students in the treatment condition obtained a GPA that was, on average, .18 points higher than first-generation students in the control condition, 3 years after values affirmation was implemented (Study 1A). We explored mechanisms by testing whether the values-affirmation effects were predicated on first-generation students reflecting on interdependent values (thus affirming their values that are consistent with working-class culture) or independent values (thus affirming their values that are consistent with the culture of higher education). We found that when first-generation students wrote about their independence, they obtained higher grades (both in the semester in which values affirmation was implemented and in subsequent semesters) and felt less concerned about their background. In a separate laboratory experiment (Study 2) we manipulated the extent to which participants wrote about independence and found that encouraging first-generation students to write more about their independence improved their performance on a math test. These studies highlight the potential of having FG students focus on their own independence. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

An exploration of student midwives' language to describe non-formal learning in professional practice.

Science.gov (United States)

Finnerty, Gina; Pope, Rosemary

2005-05-01

The essence of non-formal learning in midwifery practice has not been previously explored. This paper provides an in-depth analysis of the language of a sample of student midwives' descriptions of their practice learning in a range of clinical settings. The students submitted audio-diaries as part of a national study (Pope, R., Graham. L., Finnerty. G., Magnusson, C. 2003. An investigation of the preparation and assessment for midwifery practice within a range of settings. Project Report. University of Surrey). Participants detailed their learning activities and support obtained whilst working with their named mentors for approximately 10 days or shifts. The rich audio-diary data have been analysed using Discourse Analysis. A typology of non-formal learning (Eraut, M. 2000. Non-formal learning and implicit knowledge in professional work. British Journal of Educational Psychology 70, 113-136) has been used to provide a framework for the analysis. Non-formal learning is defined as any learning which does not take place within a formally organised learning programme (Eraut, M. 2000. Non-formal learning and implicit knowledge in professional work. British Journal of Educational Psychology 70, 113-136). Findings indicate that fear and ambiguity hindered students' learning. Recommendations include the protection of time by mentors within the clinical curriculum to guide and supervise students in both formal and non-formal elements of midwifery practice. This paper will explore the implications of the findings for practice-based education.

Teaching Arturo Ui: Triumph of Whose Will?

Science.gov (United States)

Rhiel, Mary

1993-01-01

Describes a unit on teaching Brecht in an introductory literature course, and suggests that students are better able to read and discuss Brecht's Hitler play if they first view and discuss Leni Riefenstahl's film Triumph of the Will. Guidelines are provided on how best to present and explore the two works with students. (LET)

Track structure analysis illustrating the prominent role of low-energy electrons in radiobiological effects of low-LET radiations

International Nuclear Information System (INIS)

Nikjoo, H.; Goodhead, D.T.

1991-01-01

Monte Carlo track structure methods have been used to illustrate the importance of low-energy electrons produced by low-LET radiations. It is shown that these low-energy secondary electrons contribute substantially to the dose in all low-LET irradiations and are particularly efficient at producing highly localized clusters of atomic damage which may be responsible for a major part of the biological effectiveness of low-LET radiations. The data generated by Monte Carlo track structure techniques and by earlier semi-analytical methods based on the LET concept have been compared in terms of cumulative and differential fractions of total dose absorbed as a function of electron energy. The data show that low-energy secondary electrons account for up to nearly 50% of the total dose imparted to a medium when irradiated with electrons or photons. (author)

The future of high-let radiation in cancer therapy. Justification of the heavy-ion therapy programmes

International Nuclear Information System (INIS)

Wambersie, A.

1989-01-01

The introduction of new types of ionizing radiations to control the primary tumour is a promising approach in radiation therapy. High-LET (linear energy transfer) radiations produce different biological effects compared to conventional X-rays, leading to a potential therapeutic advantage over low-LET (e.g., protons or helium ions) beams, which only are aimed at improving the physical selectivity. Introduced historically to reduce the OER (oxygen enhancement ratio), there is evidence for a reduction in radiosensitivity differences, which implies an advantage or disadvantage depending on the tumour characteristics and the normal tissues at risk, which in turn raises the problem of patient selection. From clinical data, fast neutrons were found to be superior to photons in the treatments of salivary gland tumours, prostatic adenocarcinomas, and some carcinomas. Heavy ions combine the advantages of a high physical selectivity and the potential advantage of high-LET for some tumour types. Clinical indications for the use of heavy-ion beams are therefore those tumours that reside in problematic sites but are of a type for which high-LET radiations were already shown to be useful. This review discusses the improvement of the physical selectivity with proton and helium ion beams; the differential effect and the potential advantage of neutrons and high-LET radiations (including both the radiological considerations and the clinical data); and presents the rationale for heavy-ion therapy. 38 refs, 7 figs, 10 tabs

An Exploration of Elementary School Counselors' Perceptions of Students' Exposure to Violent Video Games

Science.gov (United States)

Woody, Tammy Lynn

2010-01-01

This study explored elementary school counselors' perceptions of working with students exposed to violent video games. Certified elementary school counselors participated in both an online survey and individual interviews, revealing their observations regarding elementary school children and the phenomenon of gaming. An emphasis was placed on…

Let your communication skills equal your clinical skills.

Science.gov (United States)

Demarais, Ann; Baum, Neil

2012-01-01

Relating effectively with patients is among the most valued skills of clinical care. Honing your communication skills is an art that every physician needs to learn and understand. In this era of increased volume of patients there is a tendency to lose sight of the importance of having good communication skills. This article will review 11 suggestions for letting your communication skills equal your clinical skills.

Exploring Knowledge, Attitudes and Abuse Concerning Doping in Sport among Syrian Pharmacy Students

Directory of Open Access Journals (Sweden)

Mazen El-Hammadi

2013-09-01

Full Text Available This study aimed to assess pharmacy students’ knowledge about doping substances used in sport, explore their attitudes toward doping and investigate their misuse of doping drugs. A questionnaire was developed and employed to collect data from bachelor of pharmacy (BPharm students at the International University for Science and Technology (IUST. Two-hundred and eighty students participated in this self-administrated, paper-based survey. Around 90% of the students did not appear to know that narcotics, β-blockers and diuretics were used in sport as doping agents. Additionally, proportions between 60% and 80% considered vitamins, energy drinks and amino acids as substances that possess performance-enhancing effects. The main reason for doping, based on students’ response, was to improve muscular body appearance. The vast majority of students agreed that pharmacists should play a major role in promoting awareness about risks of doping. While students showed negative attitudes toward doping, approximately 15% of them, primarily males, had already tried a doping drug or might do so in the future. More than 60% of the students believed that sports-mates and friends are the most influential in encouraging them to take a doping agent. The study highlights the need to provide pharmacy students with advanced theoretical background and practical training concerning doping. This can be achieved by adopting simple, but essential, changes to the current curricula.

Let’s Stop HIV Together: Jamar Rogers

Centers for Disease Control (CDC) Podcasts

2012-07-16

In this podcast, singer Jamar Rogers shares his personal story in the Let's Stop HIV Together Campaign.  Created: 7/16/2012 by National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention (NCHHSTP).   Date Released: 7/16/2012.

Exploring students learning approaches in MOOCs

OpenAIRE

Faucon, Louis Pierre

2017-01-01

This study aims at understanding different students approaches for solving assignments in MOOCs. It makes use of a large dataset of logs from students interaction with the MOOC platform Coursera on a course about functional programming with Scala. In total more than 10.000 students participated in the assignments. Learning approaches are divided in two categories: starting with video lectures (V) and start- ing with the assignment (A); and students are divided in three groups: those applying ...

The survival effects of V79 cells irradiated with carbon ions in different let

International Nuclear Information System (INIS)

Wang Jufang; Zhou Guangming; He Jing; Li Wenjian; Li Qiang; Dang Bingrong; Li Xinglin; Weng Xiaoqiong; Xie Hongmei; Wei Zengquan; Gao Qingxiang

2001-01-01

The survival of cultured Chinese V79 hamster cells irradiated with carbon ions with different LETs were investigated. Irradiation was performed at the heavy Ion Research Facility in Lanzhou (HIRFL). Results were compared with those obtained from the experiments with γ rats and could be concluded as follows: The survival curves for carbon ions showed as straight lines and were fitted to the one-target one-hit model, but for γ rays the curves with shoulders were fitted to the multi-target one-hit model. As the LETs were 125, 200 and 700 keV/μm for carbon ions, the inactivation cross section 35, 12 and 8 μm 2 , respectively, which suggested that under the experimental conditions, the lower the LET of carbon ions, the more seriously the irradiation killed cells. In the case of 125 keV/μm, the RBEs of carbon ions at the 0.1 and 0.37 survival levels were 1.47 and 2.19 respectively

Water radiolysis in extreme conditions of temperature and LET. Scavenging of HO. by Br- ions

International Nuclear Information System (INIS)

Saffre, Dimitri

2011-01-01

The purpose of this thesis is to contribute to the understanding of the oxidation mechanism of Br - in which the HO . radical is involved. The HO . radiolytic yield is strongly connected with the oxidation yield of Br - , and therefore we have studied the influence of different physical and chemical parameters on this global yield: temperature, LET, dose rate, pH, saturation gas. The solutions have been irradiated with 4 types of ionizing rays: X-rays (from 13 to 18 keV), electrons (from 7 to 10 MeV), C 6+ -ions beam of 975 MeV and He 2+ -ions beam of 70 MeV. The development of an optical autoclave with solution flow, compatible with high LET ionizing rays has allowed us conduct the first experiments at constant high LET and high temperature. This cell has turned out to be compatible with the picosecond pump-probe experiments performed with the ELYSE accelerator. The HO . scavenging yield has been, therefore, estimated at both high LET and high temperature. A better understanding of the Br - oxidation mechanism has been achieved, in acid medium, in particular, by comparing the kinetics results with Monte Carlo Simulations for time scales inferior to the microsecond and with Chemsimul for the stable products (Br 2 .- and Br 3 - formations). (author) [fr

Letting Students Take the Lead: A User-Centred Approach to Evaluating Subject Guides

Directory of Open Access Journals (Sweden)

Kimberley Hintz

2010-12-01

Full Text Available Objective – What do students need and want from library subject guides? Options such as Web 2.0 enhancement are now available to librarians creating subject-specific web pages. Librarians may be eager to implement these new tools, but are such add-ons a priority forstudents? This paper aims to start a dialogue on this issue by presenting the findings of the University of British Columbia (UBC Library’s Subject Guides Working Group (SGWG, which was tasked with assessing current library subject guides in order to make recommendations for the update and future development of UBC Library subject guides.Methods – The working group solicited feedback through a questionnaire that was distributed to undergraduate and graduate students from a variety of disciplines at UBC. The questionnaire included an evaluation of UBC subject guides, as well as guides from other academic libraries that used various platforms such as LibGuides and SubjectsPlus.Results – Respondents to the student questionnaire indicated that a simple and clean layout was of primary importance. Students also desired succinct annotations to resources and limited page scrolling. Meanwhile, few students identified Web 2.0 features such as rating systems and discussion forums as being important for their needs. The working group used the questionnaire data to create a “Top Ten” list of student recommendations.Conclusions – The “Top Ten” list of student recommendations was combined with stakeholder feedback from faculty, liaison librarians and Library Systems and Information Technology representatives to create the SGWG’s final recommendation for subject guide revision and enhancement. For the SGWG these findings called into question the necessity of Web 2.0 technologies within subject guide pages and highlighted the need for further research on the topic of subject guide usability and effectiveness.

Exploration of spatio-temporal patterns of students' movement in field trip by visualizing the log data

Science.gov (United States)

Cho, Nahye; Kang, Youngok

2018-05-01

A numerous log data in addition to user input data are being generated as mobile and web users continue to increase recently, and the studies in order to explore the patterns and meanings of various movement activities by making use of these log data are also rising rapidly. On the other hand, in the field of education, people have recognized the importance of field trip as the creative education is highlighted. Also, the examples which utilize the mobile devices in the field trip in accordance to the development of information technology are growing. In this study, we try to explore the patterns of student's activity by visualizing the log data generated from high school students' field trip with mobile device.

LET-99 functions in the astral furrowing pathway, where it is required for myosin enrichment in the contractile ring.

Science.gov (United States)

Price, Kari L; Rose, Lesilee S

2017-09-01

The anaphase spindle determines the position of the cytokinesis furrow, such that the contractile ring assembles in an equatorial zone between the two spindle poles. Contractile ring formation is mediated by RhoA activation at the equator by the centralspindlin complex and midzone microtubules. Astral microtubules also inhibit RhoA accumulation at the poles. In the Caenorhabditis elegans one-cell embryo, the astral microtubule-dependent pathway requires anillin, NOP-1, and LET-99. LET-99 is well characterized for generating the asymmetric cortical localization of the Gα-dependent force-generating complex that positions the spindle during asymmetric division. However, whether the role of LET-99 in cytokinesis is specific to asymmetric division and whether it acts through Gα to promote furrowing are unclear. Here we show that LET-99 contributes to furrowing in both asymmetrically and symmetrically dividing cells, independent of its function in spindle positioning and Gα regulation. LET-99 acts in a pathway parallel to anillin and is required for myosin enrichment into the contractile ring. These and other results suggest a positive feedback model in which LET-99 localizes to the presumptive cleavage furrow in response to the spindle and myosin. Once positioned there, LET-99 enhances myosin accumulation to promote furrowing in both symmetrically and asymmetrically dividing cells. © 2017 Price and Rose. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Let's Go Toy Shopping! Exploring Early Anticipatory Socialization for Careers and Gender Expectations

Science.gov (United States)

Jones-Bodie, Ashley

2016-01-01

Courses: Gender Communication, Communication and Careers, Organizational Communication. Objectives: At the end of the activity, students will be able: to identify and analyze the socialization of gender expectations, to recognize and describe how early this type of socialization can occur, to critique the early socialization of gendered career…

Teaching and Learning Science Through Song: Exploring the experiences of students and teachers

Science.gov (United States)

Governor, Donna; Hall, Jori; Jackson, David

2013-12-01

This qualitative, multi-case study explored the use of science-content music for teaching and learning in six middle school science classrooms. The researcher sought to understand how teachers made use of content-rich songs for teaching science, how they impacted student engagement and learning, and what the experiences of these teachers and students suggested about using songs for middle school classroom science instruction. Data gathered included three teacher interviews, one classroom observation and a student focus-group discussion from each of six cases. The data from each unit of analysis were examined independently and then synthesized in a multi-case analysis, resulting in a number of merged findings, or assertions, about the experience. The results of this study indicated that teachers used content-rich music to enhance student understanding of concepts in science by developing content-based vocabulary, providing students with alternative examples and explanations of concepts, and as a sense-making experience to help build conceptual understanding. The use of science-content songs engaged students by providing both situational and personal interest, and provided a mnemonic device for remembering key concepts in science. The use of songs has relevance from a constructivist approach as they were used to help students build meaning; from a socio-cultural perspective in terms of student engagement; and from a cognitive viewpoint in that in these cases they helped students make connections in learning. The results of this research have implications for science teachers and the science education community in developing new instructional strategies for the middle school science classroom.

Let-7 microRNAs are developmentally regulated in circulating human erythroid cells

Directory of Open Access Journals (Sweden)

Reed Christopher

2009-11-01

Full Text Available Abstract Background MicroRNAs are ~22nt-long small non-coding RNAs that negatively regulate protein expression through mRNA degradation or translational repression in eukaryotic cells. Based upon their importance in regulating development and terminal differentiation in model systems, erythrocyte microRNA profiles were examined at birth and in adults to determine if changes in their abundance coincide with the developmental phenomenon of hemoglobin switching. Methods Expression profiling of microRNA was performed using total RNA from four adult peripheral blood samples compared to four cord blood samples after depletion of plasma, platelets, and nucleated cells. Labeled RNAs were hybridized to custom spotted arrays containing 474 human microRNA species (miRBase release 9.1. Total RNA from Epstein-Barr virus (EBV-transformed lymphoblastoid cell lines provided a hybridization reference for all samples to generate microRNA abundance profile for each sample. Results Among 206 detected miRNAs, 79% of the microRNAs were present at equivalent levels in both cord and adult cells. By comparison, 37 microRNAs were up-regulated and 4 microRNAs were down-regulated in adult erythroid cells (fold change > 2; p let-7 miRNA family consistently demonstrated increased abundance in the adult samples by array-based analyses that were confirmed by quantitative PCR (4.5 to 18.4 fold increases in 6 of 8 let-7 miRNA. Profiling studies of messenger RNA (mRNA in these cells additionally demonstrated down-regulation of ten let-7 target genes in the adult cells. Conclusion These data suggest that a consistent pattern of up-regulation among let-7 miRNA in circulating erythroid cells occurs in association with hemoglobin switching during the fetal-to-adult developmental transition in humans.

Applications of high-throughput clonogenic survival assays in high-LET particle microbeams

Directory of Open Access Journals (Sweden)

Antonios eGeorgantzoglou

2016-01-01

Full Text Available Charged particle therapy is increasingly becoming a valuable tool in cancer treatment, mainly due to the favorable interaction of particle radiation with matter. Its application is still limited due, in part, to lack of data regarding the radiosensitivity of certain cell lines to this radiation type, especially to high-LET particles. From the earliest days of radiation biology, the clonogenic survival assay has been used to provide radiation response data. This method produces reliable data but it is not optimized for high-throughput microbeam studies with high-LET radiation where high levels of cell killing lead to a very low probability of maintaining cells’ clonogenic potential. A new method, therefore, is proposed in this paper, which could potentially allow these experiments to be conducted in a high-throughput fashion. Cells are seeded in special polypropylene dishes and bright-field illumination provides cell visualization. Digital images are obtained and cell detection is applied based on corner detection, generating individual cell targets as x-y points. These points in the dish are then irradiated individually by a micron field size high-LET microbeam. Post-irradiation, time-lapse imaging follows cells’ response. All irradiated cells are tracked by linking trajectories in all time-frames, based on finding their nearest position. Cell divisions are detected based on cell appearance and individual cell temporary corner density. The number of divisions anticipated is low due to the high probability of cell killing from high-LET irradiation. Survival curves are produced based on cell’s capacity to divide at least 4-5 times. The process is repeated for a range of doses of radiation. Validation shows the efficiency of the proposed cell detection and tracking method in finding cell divisions.

Applications of High-Throughput Clonogenic Survival Assays in High-LET Particle Microbeams.

Science.gov (United States)

Georgantzoglou, Antonios; Merchant, Michael J; Jeynes, Jonathan C G; Mayhead, Natalie; Punia, Natasha; Butler, Rachel E; Jena, Rajesh

2015-01-01

Charged particle therapy is increasingly becoming a valuable tool in cancer treatment, mainly due to the favorable interaction of particle radiation with matter. Its application is still limited due, in part, to lack of data regarding the radiosensitivity of certain cell lines to this radiation type, especially to high-linear energy transfer (LET) particles. From the earliest days of radiation biology, the clonogenic survival assay has been used to provide radiation response data. This method produces reliable data but it is not optimized for high-throughput microbeam studies with high-LET radiation where high levels of cell killing lead to a very low probability of maintaining cells' clonogenic potential. A new method, therefore, is proposed in this paper, which could potentially allow these experiments to be conducted in a high-throughput fashion. Cells are seeded in special polypropylene dishes and bright-field illumination provides cell visualization. Digital images are obtained and cell detection is applied based on corner detection, generating individual cell targets as x-y points. These points in the dish are then irradiated individually by a micron field size high-LET microbeam. Post-irradiation, time-lapse imaging follows cells' response. All irradiated cells are tracked by linking trajectories in all time-frames, based on finding their nearest position. Cell divisions are detected based on cell appearance and individual cell temporary corner density. The number of divisions anticipated is low due to the high probability of cell killing from high-LET irradiation. Survival curves are produced based on cell's capacity to divide at least four to five times. The process is repeated for a range of doses of radiation. Validation shows the efficiency of the proposed cell detection and tracking method in finding cell divisions.

Low LET protons focused to submicrometer shows enhanced radiobiological effectiveness

Science.gov (United States)

Schmid, T. E.; Greubel, C.; Hable, V.; Zlobinskaya, O.; Michalski, D.; Girst, S.; Siebenwirth, C.; Schmid, E.; Molls, M.; Multhoff, G.; Dollinger, G.

2012-10-01

This study shows that enhanced radiobiological effectiveness (RBE) values can be generated focusing low linear energy transfer (LET) radiation and thus changing the microdose distribution. 20 MeV protons (LET = 2.65 keV µm-1) are focused to submicrometer diameter at the ion microprobe superconducting nanoprobe for applied nuclear (Kern) physics experiments of the Munich tandem accelerator. The RBE values, as determined by measuring micronuclei (RBEMN = 1.48 ± 0.07) and dicentrics (RBED = 1.92 ± 0.15), in human-hamster hybrid (AL) cells are significantly higher when 117 protons were focused to a submicrometer irradiation field within a 5.4 × 5.4 µm2 matrix compared to quasi homogeneous in a 1 × 1 µm2 matrix applied protons (RBEMN = 1.28 ± 0.07; RBED = 1.41 ± 0.14) at the same average dose of 1.7 Gy. The RBE values are normalized to standard 70 kV (dicentrics) or 200 kV (micronuclei) x-ray irradiation. The 117 protons applied per point deposit the same amount of energy like a 12C ion with 55 MeV total energy (4.48 MeV u-1). The enhancements are about half of that obtained for 12C ions (RBEMN = 2.20 ± 0.06 and RBED = 3.21 ± 0.10) and they are attributed to intertrack interactions of the induced damages. The measured RBE values show differences from predictions of the local effect model (LEM III) that is used to calculate RBE values for irradiation plans to treat tumors with high LET particles.

Snapshots of Student Thinking: An Exploration of Video Cases for Extending Prospective Teachers' Knowledge

Science.gov (United States)

Pitts Bannister, Vanessa R.; Mariano, Gina J.

2013-01-01

The purpose of this article is to explore the relationships between prospective teachers' content knowledge, student understanding, and pedagogy using video cases. The emphasis was on the extent to which the participants utilized constructs of Technology Pedagogy And Content Knowledge. Ten prospective teachers viewed video cases of students…

An Exploration of the Effect of Servicescape on Student Institution Choice in UK Universities

Science.gov (United States)

Winter, Emma; Chapleo, Chris

2017-01-01

In recent years there has been increased discussion of the subjective, emotional and sociological factors influencing student choice of university. However, there is a dearth of information exploring what constitutes these feelings. This exploratory paper uses the conceptual model of the servicescape to provide insight into the emotional factors…

College Students' Experiences and Perceptions of Harassment on Campus: An Exploration of Gender Differences

Science.gov (United States)

Reason, Robert D.; Rankin, Susan R.

2006-01-01

Using a campus climate assessment instrument developed by Rankin (1998), we surveyed students (N = 7,347) from 10 campuses to explore the different experiences with harassment and campus climates reported by men and women. Both men and women reported experiencing harassment, although women experienced harassment at statistically significantly…

A critique of Katz's 'High LET constraint on low LET survival'

International Nuclear Information System (INIS)

Burch, P.R.J.; Chesters, M.S.

1979-01-01

Katz's interpretation of the connexion between RBE and LET is contrasted with a version published previously by Burch. The implications of Katz's model for dose-response relations apply only at ultra-high absorbed doses in Burch's model. In the latter, the shoulder on type-C survival curves for mammalian cells is explained in terms of Haynes' repair model. Under certain conditions the repair model becomes mathematically equivalent to the α-β model; under some other conditions it becomes equivalent to the 'two-component' model. The formulation of a new repair hypothesis, based on the idea of an inducible repair mechanism, is also set out. It is argued that Katz's supralinearity index' is appropriate to the induction of (rare) mutations but inappropriate to cell survival, for which an alternative index is proposed. Certain plausible hypotheses of radiobiological action conflict with Katz's 'logical constraint' which, it is contended, is neither logical nor valid. In conclusion, although experimental findings for some radiobiological systems conform to Katz's 'constraint', the frequently observed violations should not necessarily be regarded as artefacts. (author)

Instructor Misbehaviors as Digital Expectancy Violations: What Students Despise and What They Let Slide

Science.gov (United States)

MacArthur, Brenda L.; Villagran, Melinda M.

2015-01-01

This study examines students' motives for communicating with their instructors when the instructor exhibits inappropriate or unprofessional online behavior. To understand the relationship between what we call instructors' digital expectancy violations and students' motives for communicating with instructors, students' levels of task, social, and…

The role of long noncoding RNA-LET in cell proliferation and invasion of nasopharyngeal carcinoma and its mechanism

Directory of Open Access Journals (Sweden)

Chen L

2017-05-01

Full Text Available Lei Chen,1,* Lingling Sun,1,* Lei Dong,2 Peng Cui,3 Ziwei Xia,4 Chao Li,1 Yu Zhu5 1Department of Otolaryngology, The Second Hospital of Tianjin Medical University, Tianjin, People’s Republic of China; 2Department of Pediatrics, Division of Hematology/Oncology, Aflac Cancer and Blood Disorders Center, Emory University School of Medicine, Atlanta, GA, USA; 3Department of Multidisciplinary Consultation Center of TCM and Western Medicine, The Affiliated Qingdao Hiser Hospital of Qingdao University, Qingdao, 4Department of Clinical Medicine, The Second Clinical Medical School of Tianjin Medical University, 5Department of Clinical Laboratory, Tianjin Huanhu Hospital, Tianjin Key Laboratory of Cerebral Vessels and Neural Degeneration, Tianjin, People’s Republic of China *These authors contributed equally to this work Abstract: LncRNA-LET, a recently identified long noncoding RNA, has been shown to act as a tumor suppressor; however, its biological function and mechanism have not been fully investigated. Our research found that there was less expression of LET in nasopharyngeal carcinoma (NPC tissues than normal tissues and that LET might inhibit proliferation, adhesion and invasion of NPC in vitro by enhancing its expression. By contrast, decreased LET expression could promote the proliferation, adhesion and invasion of NPC. In addition, the expression profiles of related genes and MAPK/ERK pathway were also regulated effectively via overexpression or silencing of LET. This result provides comprehensive evidence of LET’s antitumor effect on NPC in vitro, which might provide a new approach for clinical treatment. Keywords: LncRNA-LET, proliferation, invasion, nasopharyngeal carcinoma, MAPK/ERK pathway

CXCR4/Let-7a Axis Regulates Metastasis and Chemoresistance of Pancreatic Cancer Cells Through Targeting HMGA2

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Guangfa Xiao

2017-09-01

Full Text Available Background/Aims: Pancreatic cancer cells (PCC is one of the most risky cancers and gemcitabine (GEM is the standard first-line drug for treating PCC. The PCC will develop drug resistance to GEM after a period of treatment. However, the detailed molecular mechanism of pathogenesis and drug resistance remains unresolved. Methods: we employed qRT-PCR and western blot to examine the expression level of CXCR4, let-7a and HMGA2. In addition, we used MTT assay to detect cell proliferation and transwell assay to measure migration and invasiveness. The expression level of epithelial marker E-cadherin and mesenthymal marker N-cadherin was detected by western blot. The apoptosis was determined using annexin V-FITC/PI apoptosis detection kit by flow cytometry. Results: we first proved that CXCR4 negatively regulated let-7a in PCC. Next, let-7a was confirmed to play crucial role in tumorigenesis, metastasis and drug resistance of pancreatic cancer cells Bxpc-3 and Panc-1 in vitro and in vivo. Finally, we identified HMGA2 as important downsteam target of let-7a in PCC and overexpression of HMGA2 restores cell proliferation, metastasis and chemosensitivity of GEM inhibited by let-7a. Conlusion: Taken together, we show an important signaling pathway involved in pathogenesis and drug resistance of PCC, thereby providing deeper insight into molecular mechanism by which CXCR4/let-7a regulates tumorigenesis and drug resistance of PCC. These findings will help us develop new strategies for diagnosis and treatment of PCC.

Exploring the Relationship between Time Management Skills and the Academic Achievement of African Engineering Students--A Case Study

Science.gov (United States)

Swart, Arthur James; Lombard, Kobus; de Jager, Henk

2010-01-01

Poor academic success by African engineering students is currently experienced in many higher educational institutions, contributing to lower financial subsidies by local governments. One of the contributing factors to this low academic success may be the poor time management skills of these students. This article endeavours to explore this…

Robust and Fragile Mathematical Identities: A Framework for Exploring Racialized Experiences and High Achievement among Black College Students

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McGee, Ebony O.

2015-01-01

I introduce the construct of fragile and robust identities for the purpose of exploring the experiences that influenced the mathematical and racial identities of high-achieving Black college students in mathematics and engineering. These students maintained high levels of academic achievement in these fields while enduring marginalization,…

Exploring the Relationship between Experienced Students' Preference for Open- and Closed-Book Examinations, Approaches to Learning and Achievement

Science.gov (United States)

Karagiannopoulou, Evangelia; Milienos, Fotios S.

2013-01-01

The relationship between university students' approaches to learning and preference for the open- and closed-book examinations was investigated for 144 Greek undergraduate (56 third- and 88 fourth-year) students attending a Philosophy, Education and Psychology Department. The approaches were explored by the Approaches and Study Skills Inventory…

A Physics MOSAIC: Scientific Skills and Explorations for Students

Science.gov (United States)

May, S.; Clements, C.; Erickson, P. J.; Rogers, A.

2010-12-01

MOSAIC unit begins with a series of activities and lessons designed to take advantage of the large data sets MOSAIC is collecting all the time to teach students about measurement, uncertainty, and data analysis. The curriculum develops an intuitive approach to thinking about numbers in science, focusing on both implicit and explicit expressions of uncertainty. Our teaching unit concludes with a final research project to provide students with the opportunity to pursue an area of interest within mesospheric ozone. This project is conceived in such a way that it can be as self-directed as a teacher or student needs. Given current concern for the state of our atmosphere and ozone, MOSAIC provides a unique opportunity for student engagement in an area of scientific research that has not been extensively explored. MOSAIC data can be compared with online resources for other atmospheric, astronomical, or geophysical data, and have been analyzed for the effects of such variables as seasonal and solar flux variations, lunar phases, shuttle and rocket launches, and sudden stratospheric warming events.

International students' experience of a western medical school: a mixed methods study exploring the early years in the context of cultural and social adjustment compared to students from the host country.

Science.gov (United States)

McGarvey, A; Brugha, R; Conroy, R M; Clarke, E; Byrne, E

2015-07-02

Few studies have addressed the challenges associated with international students as they adapt to studying medicine in a new host country. Higher level institutions have increasing numbers of international students commencing programmes. This paper explores the experiences of a cohort of students in the early years of medical school in Ireland, where a considerable cohort are from an international background. A mixed exploratory sequential study design was carried out with medical students in the preclinical component of a five year undergraduate programme. Data for the qualitative phase was collected through 29 semi-structured interviews using the peer interview method. Thematic analysis from this phase was incorporated to develop an online questionnaire combined with components of the Student Adaptation to College Questionnaire and Student Integration Questionnaire. First year students were anonymously surveyed online. The Mokken Scaling procedure was used to investigate the students' experiences, both positive and negative. Three main themes are identified; social adjustment, social alienation and cultural alienation. The response rate for the survey was 49% (467 Respondents). The Mokken Scaling method identified the following scales (i) Positive experience of student life; (ii) Social alienation, which comprised of negative items about feeling lonely, not fitting in, being homesick and (iii) Cultural alienation, which included the items of being uncomfortable around cultural norms of dress and contact between the sexes. With the threshold set to H = 0.4. Subscales of the positive experiences of student life scale are explored further. Overall student adjustment to a western third level college was good. Students from regions where cultural distance is greatest reported more difficulties in adjusting. Students from these regions also demonstrate very good adaptation. Some students from the host country and more similar cultural backgrounds were also

Take a Selfie of Life: A Qualitative Exploration of College Students' Self-Reflections on Free Time Use and Personal Values

Science.gov (United States)

Chen, Hsin-Yu; Yarnal, Careen; Hustad, John T. P.; Sims, Damon

2016-01-01

Adopting a qualitative approach, this study explores college students' self-reflections on free time use and personal values. Data were collected from 111 students' final reflection papers for a class entitled "Leisure and Human Behavior." The findings suggest that leisure education may empower students with fundamental knowledge about…

Depression of p53-independent Akt survival signals in human oral cancer cells bearing mutated p53 gene after exposure to high-LET radiation

Energy Technology Data Exchange (ETDEWEB)

Nakagawa, Yosuke [Department of Oral and Maxillofacial Surgery, School of Medicine, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521 (Japan); Takahashi, Akihisa [Advanced Scientific Research Leader Development Unit, Gunma University, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511 (Japan); Kajihara, Atsuhisa; Yamakawa, Nobuhiro; Imai, Yuichiro [Department of Oral and Maxillofacial Surgery, School of Medicine, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521 (Japan); Ota, Ichiro; Okamoto, Noritomo [Department of Otorhinolaryngology, School of Medicine, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521 (Japan); Mori, Eiichiro [Department of Radiation Oncology, School of Medicine, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521 (Japan); Noda, Taichi [Department of Dermatology, School of Medicine, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521 (Japan); Furusawa, Yoshiya [Heavy-ion Radiobiology Research Group, Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Kirita, Tadaaki [Department of Oral and Maxillofacial Surgery, School of Medicine, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521 (Japan); Ohnishi, Takeo, E-mail: tohnishi@naramed-u.ac.jp [Department of Radiation Oncology, School of Medicine, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521 (Japan)

2012-07-13

Highlights: Black-Right-Pointing-Pointer High-LET radiation induces efficiently apoptosis regardless of p53 gene status. Black-Right-Pointing-Pointer We examined whether high-LET radiation depresses the Akt-survival signals. Black-Right-Pointing-Pointer High-LET radiation depresses of survival signals even in the mp53 cancer cells. Black-Right-Pointing-Pointer High-LET radiation activates Caspase-9 through depression of survival signals. Black-Right-Pointing-Pointer High-LET radiation suppresses cell growth through depression of survival signals. -- Abstract: Although mutations and deletions in the p53 tumor suppressor gene lead to resistance to low linear energy transfer (LET) radiation, high-LET radiation efficiently induces cell lethality and apoptosis regardless of the p53 gene status in cancer cells. Recently, it has been suggested that the induction of p53-independent apoptosis takes place through the activation of Caspase-9 which results in the cleavage of Caspase-3 and poly (ADP-ribose) polymerase (PARP). This study was designed to examine if high-LET radiation depresses serine/threonine protein kinase B (PKB, also known as Akt) and Akt-related proteins. Human gingival cancer cells (Ca9-22 cells) harboring a mutated p53 (mp53) gene were irradiated with 2 Gy of X-rays or Fe-ion beams. The cellular contents of Akt-related proteins participating in cell survival signaling were analyzed with Western Blotting 1, 2, 3 and 6 h after irradiation. Cell cycle distributions after irradiation were assayed with flow cytometric analysis. Akt-related protein levels decreased when cells were irradiated with high-LET radiation. High-LET radiation increased G{sub 2}/M phase arrests and suppressed the progression of the cell cycle much more efficiently when compared to low-LET radiation. These results suggest that high-LET radiation enhances apoptosis through the activation of Caspase-3 and Caspase-9, and suppresses cell growth by suppressing Akt-related signaling, even in mp

Acculturation orientations and Chinese student Sojourners’ career adaptability : the roles of career exploration and cultural distance.

OpenAIRE

Guan, Y.; Liu, S.; Guo, M.J.; Li, M.; Wu, M.; Chen, S.X.; Xu, S.X.; Tian, L.

2018-01-01

Drawing on career construction theory and Berry's acculturation model, this study examined how student sojourners' acculturation orientations predicted their career exploration and career adaptability. We conducted a survey study among Chinese student sojourners (N = 222) and the results showed that after the effects of big-five personality and approach/avoidance traits were controlled, both host culture orientation and home culture orientation had positive indirect effects on career adaptabi...

Exploring the Relationship Between Students with Accommodations and Instructor Self-Efficacy in Complying with Accommodations

Directory of Open Access Journals (Sweden)

Anna M. Wright

2017-06-01

Full Text Available The willingness and flexibility of university instructors to comply with and provide accommodations for students with disabilities is critical to academic success. The authors examine how communication between students needing accommodations and university instructors impacts instructor self-efficacy, or instructors’ perception that they can meet the accommodation. Specifically, the authors’ explored the relationship between student self-disclosure of a disability and instructor empathy, flexibility, and self-efficacy in meeting student accommodation needs. Results revealed that the more a student self-discloses about a needed accommodation, the more self-efficacy an instructor has in making that accommodation. For the low-disclosure condition, empathy and flexibility were both significant predictors of self-efficacy, whereas, for the high-disclosure condition, only flexibility was a significant predictor of self-efficacy. Finally, instructors’ levels of empathy and flexibility both decreased after reading both the high and low self-disclosure scenarios.

Dual peer mentoring program for undergraduate medical students: exploring the perceptions of mentors and mentees.

Science.gov (United States)

Abdolalizadeh, Parya; Pourhassan, Saeed; Gandomkar, Roghayeh; Heidari, Farrokh; Sohrabpour, Amir Ali

2017-01-01

Background: Despite the advantages of dual peer mentoring, there are a few reports of implementing and evaluating such programs for medical students. This study aimed at exploring the perceptions of mentors and mentees about the dual peer mentoring program for the first year undergraduate medical students of Tehran University of Medical Sciences. Methods: This qualitative study was conducted at the end of the first year of implementing the mentoring program. All mentees and mentors were invited to participate in focus group discussions. Data were analyzed using a qualitative content analysis. Results: All mentors ( n= 12 ) and a group of mentees ( n= 21 ) participated in focus group discussion sessions. We provided a variety of supports for the mentees including academic and psychosocial support and positive relationship; as a result, some developments occurred to the mentors We also explored participants' views on some unique aspects of the program such as student-authorized, dual mentoring, and role model sessions. Conclusion: Our participants found the mentoring program beneficial in various academic achievements and psychosocial supports for both the mentors and the mentees. Dual peer mentoring program can be an alternative to school administered programs.

Hands Off: Mentoring a Student-Led Robotics Team

Science.gov (United States)

Dolenc, Nathan R.; Mitchell, Claire E.; Tai, Robert H.

2016-01-01

Mentors play important roles in determining the working environment of out-of-school-time clubs. On robotics teams, they provide guidance in hopes that their protégés progress through an engineering process. This study examined how mentors on one robotics team who defined their mentoring style as "let the students do the work" navigated…

"Who am I supposed to let down?": The caring work and emotional practices of vocational educational training teachers working with potential drop-out students

DEFF Research Database (Denmark)

Lippke, Lena

2012-01-01

initiatives and as a result, most colleges have established extended basic courses aimed at students with personal, social and/or academic difficulties. This paper aims to explore the emotional aspects of vocational educational teachers’ work and present a preliminary analysis of the notion of care....... Findings – The paper provides empirical insights into the emotional practices and the management of emotions related to prevention of dropout within an educational setting. It shows how emotional practices can provide both teachers and students with positive identities and make out a productive force...... that prevents students from dropping out. However the management of emotions also involves a range of dilemmas and ambivalences revealing the difficult limitations related to an institutionalization and professionalization of human care. Research limitations/implications – Because of the chosen research design...

Giving children space: A phenomenological exploration of student experiences in space science inquiry

Science.gov (United States)

Horne, Christopher R.

This study explores the experiences of 4th grade students in an inquiry-based space science classroom. At the heart of the study lies the essential question: What is the lived experience of children engaged in the process of space science inquiry? Through the methodology of phenomenological inquiry, the author investigates the essence of the lived experience of twenty 4th grade students as well as the reflections of two high school students looking back on their 4th grade space science experience. To open the phenomenon more deeply, the concept of space is explored as an overarching theme throughout the text. The writings of several philosophers including Martin Heidegger and Hans-Georg Gadamer are opened up to understand the existential aspects of phenomenology and the act of experiencing the classroom as a lived human experience. The methodological structure for the study is based largely on the work of Max van Manen (2003) in his seminal work, Researching Lived Experience, which describes a structure of human science research. A narrative based on classroom experiences, individual conversations, written reflections, and group discussion provides insight into the students' experiences. Their stories and thoughts reveal the themes of activity , interactivity, and "inquiractivity," each emerging as an essential element of the lived experience in the inquiry-based space science classroom. The metaphor of light brings illumination to the themes. Activity in the classroom is associated with light's constant and rapid motion throughout the Milky Way and beyond. Interactivity is seen through students' interactions just as light's reflective nature is seen through the illumination of the planets. Finally, inquiractivity is connected to questioning, the principal aspect of the inquiry-based classroom just as the sun is the essential source of light in our solar system. As the era of No Child Left Behind fades, and the next generation of science standards emerge, the

Evaluering af ordning med psykologbehandling af personer med let til moderat depression

DEFF Research Database (Denmark)

Fjeldsted, Rita; Christensen, Kaj Sparle

Herværende rapport evaluerer den pr. 1.4.2008 indførte ordning med mulighed for henvisning til psykologbehandling med 60 % tilskud for patienter med let til moderat depression. Evalueringen har betjent sig af flere gensidigt supplerende metoder: spørgeskemaundersøgelser overfor patienter, psykolo......Herværende rapport evaluerer den pr. 1.4.2008 indførte ordning med mulighed for henvisning til psykologbehandling med 60 % tilskud for patienter med let til moderat depression. Evalueringen har betjent sig af flere gensidigt supplerende metoder: spørgeskemaundersøgelser overfor patienter...... tidligere evaluering af forsøgsordning af psykologbehandling af depression i perioden 2005-06. 18.419 personer i alderen 18-37 år blev henvist til psykolog i den undersøgte ordning i perioden 1.2.2009 – 31.1.2010, svarende til en henvisningshyppighed på 1,6 % af baggrundsbefolkningen i samme aldersgruppe....... Ordningen giver mulighed for én rehenvisning, og 9 % blev rehenvist i perioden. Spørgeskemaresultater viser, at kun 33 % af de henviste falder ind under henvisningskriteriet ” let til moderat depression” på tidspunktet for opstart af psykologbehandling, 39 % har ingen tegn på depression, og 28 % har svær...

Exploring the transition of undergraduate medical students into a clinical clerkship using organizational socialization theory.

Science.gov (United States)

Atherley, Anique E; Hambleton, Ian R; Unwin, Nigel; George, Colette; Lashley, Paula M; Taylor, Charles G

2016-04-01

Transitions in medical education are emotionally and socially dynamic; this may affect learning. Students transitioning from preclinical to clinical training may experience negative consequences. Less is understood about students' experiences during transitions within clinical training and influential factors. The authors used organizational socialization theory to explore a transition within the clinical years. Final-year medical students experienced a nine-week internal medicine clerkship; willing students participated. Students (n = 101; 97 %) completed a questionnaire with open-ended questions at the beginning and end of the clerkship and participated in six consecutive focus groups, until data saturation occurred (n = 37). Data were thematically analyzed. Socialization was challenging. Many students experienced difficulty developing relationships with team members. Students with a positive attitude experienced a smoother transition. Many students were uncertain of their roles, concerned about the workload and desired guidance to meet clerkship demands. This transition resulted in varied outcomes from enjoyment, increased confidence and student development through to disinterest. Transitions within clinical training are complex. Faculty should focus on adequate socialization in a new clerkship as this may facilitate a smoother transition. This may necessitate orientations, staff training, and formal student support. Further research is needed on the impact of these recommendations on learning and well-being.

Exploring Kuwaiti mathematics: student-teachers' beliefs toward using Logo and mathematics education

OpenAIRE

Sulaiman, NAJ

2011-01-01

The main objective of this study is to explore the effect of one taught course, a Logo module, on Kuwaiti elementary mathematics student-teachers’ beliefs about Information and Communication Technology (ICT) and Logo. The Logo module incorporated ICT, in particular the Logo programming language, as a cognitive tool, that supports the constructivist perspective for mathematics instruction. The Logo module comprised of 24-sessions (deducted from the hours of the Methods of Teaching Mathematics ...

An Exploration of Relationships between Leadership and Student Citizenship Outcomes in Cyprus Middle Schools

Science.gov (United States)

Savvides, Vassos; Pashiardis, Petros

2016-01-01

Purpose: The main purpose of this study was to explore direct and indirect relationships between Leadership and Student Citizenship Outcomes in Cyprus middle schools. In the case of indirect effects the mediating role of School Academic Optimism and Instructional Quality was examined. Method: The specific study adopted a value-added quantitative…

A Preliminary Exploration of Uppercase Letter-Name Knowledge among Students with Significant Cognitive Disabilities

Science.gov (United States)

Greer, Claire W.; Erickson, Karen A.

2018-01-01

There are several factors known to impact the alphabet knowledge of young children without disabilities. The impact of these factors on the alphabet knowledge of students with significant cognitive disabilities is unknown. The purpose of this preliminary investigation was to explore the impact of three factors that might influence uppercase…

[Analysis of Therapeutic Regularities and Characteristics of Blood-letting Therapy for Acne Patients Based on Data Mining].

Science.gov (United States)

Du, Yu-zhu; Jia, Chun-sheng; Wang, Jian-ling; Shi, Jing; Zhang, Xiao-xu; Liu, Xin; Gang, Wei-juan

2015-06-01

To analyze the therapeutic regularities and characteristics of blood-letting therapy for acne in the past clinical practice by using data mining. Original papers about acne treated by pricking blood therapy were searched and screened from common databases as Chinese National Knowledge Infrastructure Database (CNKI), WanFang Data, SinoMed, Ovid, ScienceDirect, Socolar, SciFinder, Foreign Medical Journal Full-Text Service (FMJS) and PubMed using keywords of acne+bleeding therapy, acne+blood-letting, acne+ pricking blood, followed by establishing a data plateform to conduct a data mining using Online Analytical Processing (OLAP). A total of 230 original journal articles about acne treated by pricking blood therapy were collected. The included acne cases with wind-heat pattern were predoment, being 56 in frequency-times and acounting for 24. 78 %. In the treatment of acne, the therapeutic tool, three-edged needle was often used, being 168 in frequency and acounting for 71.79%. The frequently employed acupoints were those of the Governor Vessel and Bladder Meridian, such as Dazhui (GV 14) and back-shu points. When auricular points used for blood-letting, Erjian (EX-HN 6) and the Vena of the auricular back were most frequently selected. In addition to blood-letting, other therapies such as Chinese herbal medicines, filiform needles, and otopoint-pellet pressure were also used in combination, being 166 in items and constituting 72. 17%. Generally, blood-letting treatment was conducted once every three days (twice a week) or once every two days (three times a week) for about 20 sessions for each acne patient. Blood-letting therapy is effective in the treatment of acne. But if used in combination with other therapies, the therapeutic effect would be better.

A Qualitative Exploration of Former College Student-Athletes’ Wellness

Directory of Open Access Journals (Sweden)

Warehime Shane

2017-10-01

Full Text Available College student-athletes (SAs may experience difficulties while transitioning from college, which could reduce their overall wellness. However, it is essential to understand positive transition experiences and outcomes, as this can guide future research and intervention efforts. The purpose of this study was to explore the factors that led to higher levels of wellness in former SAs. Semi-structured interviews guided by the Indivisible Self Model were completed with former SAs (n = 12. Overall, participants displayed high levels of wellness - most prominently in terms of work and exercise. Many SAs perceived their current wellness was equal, if not better compared to when they were SAs. These results illustrate examples of successful transitions of former SAs, which can guide future research and interventions.

Eesti ja Soome kooliõpilased toovad lavale muusikali "Let Mamma Mia in!"

Index Scriptorium Estoniae

2006-01-01

21. okt. Kaja keskuses etendavad Tallinna 32. keskkooli ja Meri-Porin Lukio õpilased muusikali "Let Mamma Mia in". Muusikal koosneb muusikalihittidest, mille on looks kokku kirjutanud Sven Kivisildnik

Exploring the Contribution of Teaching and Learning Processes in the Construction of Students' Gender Identity in Early Year Classrooms

Science.gov (United States)

Baig, Amina

2014-01-01

The present study explores how gender identity construction takes place in a single gender classroom in early years. Qualitative research guided the study design which was conducted in two public sector single gender schools. The data were collected through observations of the teacher-student interaction, student-student interaction, focused group…

Exploring the Use of Interactive Digital Storytelling Video: Promoting Student Engagement and Learning in a University Hybrid Course

Science.gov (United States)

Shelton, Catharyn C.; Warren, Annie E.; Archambault, Leanna M.

2016-01-01

This study explores interactive digital storytelling in a university hybrid course. Digital stories leverage imagery and narrative-based content to explore concepts, while appealing to millennials. When digital storytelling is used as the main source of course content, tensions arise regarding how to engage and support student learning while…

Hierarchies and learning in the conservatoire : exploring what students learn through the lens of Bourdieu

NARCIS (Netherlands)

Burt-Perkins, Rosie

2013-01-01

This article explores the intersection between institutional hierarchies and learning at a UK conservatoire. Conceptualizing learning as a social practice situated in a hierarchical social space, the article draws on the theorization of Bourdieu to understand how students are positioned in the

Exploring factors affecting undergraduate medical students' study strategies in the clinical years: a qualitative study.

NARCIS (Netherlands)

Al Kadri, H.M.; Al-Moamary, M.S.; Elzubair, M.; Magzoub, M.E.; AlMutairi, A.; Roberts, C.; Vleuten, C.P.M. van der

2011-01-01

The aim of this study is to explore the effects of clinical supervision, and assessment characteristics on the study strategies used by undergraduate medical students during their clinical rotations. We conducted a qualitative phenomenological study at King Saud Bin Abdulaziz University for Health

White House Unveils America's College Promise Proposal: Tuition-Free Community College for Responsible Students. Fact Sheet

Science.gov (United States)

The White House, 2015

2015-01-01

In January, 2015, the President unveiled the America's College Promise proposal, which would make two years of community college free for responsible students, letting students earn the first half of a bachelor's degree and earn skills needed in the workforce at no cost. This proposal will require everyone to do their part: community colleges must…

SU-F-T-239: Evaluation of Plastic Scintillator Light Output for Various Lead Doping Concentrations: Towards LET Detection

International Nuclear Information System (INIS)

Nusrat, H; Pang, G; Sarfehnia, A

2016-01-01

Purpose: This work seeks to develop a beam quality meter using multiple differently doped plastic scintillators that are thus intrinsically beam-quality dependent. Plastic scintillators spontaneously emit visible light upon irradiation; the amount of light produced is dependent on stopping power (closely related to LET) according to Birks’ law. Doping plastic scintillators can be used to tune their sensitivity to specific LET ranges. Methods: GEANT4.10.1 Monte Carlo (MC) was used to evaluate the response of various scintillator dopant combinations. MC radiation transport and scintillator light response were validated against previously published literature. Current work involves evaluating detector response experimentally; to that end, a detector prototype with interchangeable scintillator housing was constructed. Measurement set-up guides light emitted by the scintillator to a photomultiplier tube via a glass taper junction coupled to an optical fiber. The resulting signal is measured by an electrometer, and normalized to dose readout from a diode. Measurements have been done using clinical electron and orthovoltage beams. MC response (simulated scintillator light normalized to dose scored inside the scintillating volume) was evaluated for four different LET radiations for an undoped and 1%Pb doped scintillator (σ=0.85%). Simulated incident electrons included: 0.05, 0.1, 0.2, 6, 12, and 18 MeV; these energies correspond to a range of stopping power (related to LET) values ranging from 1.824 to 11.09 MeVcm"2g"−"1 (SCOL from NIST-ESTAR). Results: Initial MC results show a distinct divergence in scintillator response as LET increases. The response for undoped plastic scintillator indicated a 35.0% increase in signal when going from 18 MeV (low LET) to 0.05 MeV (high LET) while 1%-Pb doped scintillator indicated a 100.9% increase. Conclusion: After validating MC against measurement, simulations will be used to test various concentrations (2%, 4%, 6%) of different

SU-F-T-239: Evaluation of Plastic Scintillator Light Output for Various Lead Doping Concentrations: Towards LET Detection

Energy Technology Data Exchange (ETDEWEB)

Nusrat, H [Ryerson University, Toronto, ON (Canada); Pang, G; Sarfehnia, A [Sunnybrook Health Sciences Centre, Toronto, ON (Canada)

2016-06-15

Purpose: This work seeks to develop a beam quality meter using multiple differently doped plastic scintillators that are thus intrinsically beam-quality dependent. Plastic scintillators spontaneously emit visible light upon irradiation; the amount of light produced is dependent on stopping power (closely related to LET) according to Birks’ law. Doping plastic scintillators can be used to tune their sensitivity to specific LET ranges. Methods: GEANT4.10.1 Monte Carlo (MC) was used to evaluate the response of various scintillator dopant combinations. MC radiation transport and scintillator light response were validated against previously published literature. Current work involves evaluating detector response experimentally; to that end, a detector prototype with interchangeable scintillator housing was constructed. Measurement set-up guides light emitted by the scintillator to a photomultiplier tube via a glass taper junction coupled to an optical fiber. The resulting signal is measured by an electrometer, and normalized to dose readout from a diode. Measurements have been done using clinical electron and orthovoltage beams. MC response (simulated scintillator light normalized to dose scored inside the scintillating volume) was evaluated for four different LET radiations for an undoped and 1%Pb doped scintillator (σ=0.85%). Simulated incident electrons included: 0.05, 0.1, 0.2, 6, 12, and 18 MeV; these energies correspond to a range of stopping power (related to LET) values ranging from 1.824 to 11.09 MeVcm{sup 2}g{sup −1} (SCOL from NIST-ESTAR). Results: Initial MC results show a distinct divergence in scintillator response as LET increases. The response for undoped plastic scintillator indicated a 35.0% increase in signal when going from 18 MeV (low LET) to 0.05 MeV (high LET) while 1%-Pb doped scintillator indicated a 100.9% increase. Conclusion: After validating MC against measurement, simulations will be used to test various concentrations (2%, 4%, 6%) of

Transitioning in Higher Education: An Exploration of Psychological and Contextual Factors Affecting Student Satisfaction

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Pennington, Charlotte R.; Bates, Elizabeth A.; Kaye, Linda K.; Bolam, Lauren T.

2018-01-01

In view of recent changes in the higher education sector, such as increased tuition fees, a greater focus has been placed on widening participation initiatives and monitoring student satisfaction. The aims of the current study were twofold: (1) to explore whether pre-entry programmes foster successful transition to higher education, and (2) to…

Synergy and Students' Explanations: Exploring the Role of Generic and Content-Specific Scaffolds

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Delen, Ibrahim; Krajcik, Joseph

2018-01-01

In this study, we explored how a teacher used a new mobile application that enables students to collect data inside and outside the classroom, and then use the data to create scientific explanations by using claim-evidence-reasoning framework. Previous technologies designed to support scientific explanations focused on how these programs improve…

Predicting Change over Time in Career Planning and Career Exploration for High School Students

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Creed, Peter A.; Patton, Wendy; Prideaux, Lee-Ann

2007-01-01

This study assessed 166 high school students in Grade 8 and again in Grade 10. Four models were tested: (a) whether the T1 predictor variables (career knowledge, indecision, decision-making selfefficacy, self-esteem, demographics) predicted the outcome variable (career planning/exploration) at T1; (b) whether the T1 predictor variables predicted…

An Exploration of Language Anxiety in L2 Academic Context for Chinese International Students in U.S. Universities

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Zhao, Qing

2013-01-01

This mix-methods study examined the language anxiety levels that the Chinese international students perceived in second language (L2) academic context at four universities in the northeastern region of the United States of America; it explored the impact of language anxiety that these students perceived on their academic learning; it also…

Self-Efficacy, Perceptions of Barriers, Vocational Identity, and the Career Exploration Behavior of Latino/a High School Students

Science.gov (United States)

Gushue, George V.; Clarke, Christine P.; Pantzer, Karen M.; Scanlan, Kolone R. L.

2006-01-01

This study explored the potential relationship between the social cognitive variables of career decision making self-efficacy and perceptions of barriers and the outcome variables of vocational identity and career exploration behaviors in a sample of 128 urban Latino/a high school students. The results indicated that higher levels of career…

Engineers' Responsibilities for Global Electronic Waste: Exploring Engineering Student Writing Through a Care Ethics Lens.