Sample records for agregado natural nos

  1. Multifaceted NOS Instruction: Contextualizing Nature of Science with Documentary Films

    ERIC Educational Resources Information Center

    Bloom, Mark; Binns, Ian C.; Koehler, Catherine

    2015-01-01

    This research focuses on inservice science teachers' conceptions of nature of science (NOS) before and after a two-week intensive summer professional development (PD). The PD combined traditional explicit NOS instruction, numerous interactive interventions that highlighted NOS aspects, along with documentary films that portrayed NOS in context of…

  2. The influence of authentic scientific research experiences on teachers' conceptions of the nature of science (NOS) and their NOS teaching practices

    NASA Astrophysics Data System (ADS)

    Moriarty, Meghan A.

    This study explored the influence of teachers' authentic scientific research experiences (ASREs) on teachers' conceptions of the nature of science (NOS) and teachers' NOS instruction. Twelve high school biology teachers participated in this study. Six of the participants had authentic scientific research experience (ASRE) and six had not participated in authentic scientific research. Data included background surveys, modified Views of the Nature of Science (VNOS) questionnaires, interviews, and teaching observations. Data was coded based on the eight NOS understandings outlined in 2013 in the Next Generation Science Standards (NGSS). Evidence from this study indicates participating in authentic scientific research as a member of a scientific community has dual benefits of enabling high school science teachers with informed understandings of the NOS and positioning them to teach with the NOS. However, these benefits do not always result from an ASRE. If the nature of the ASRE is limited, then it may limit teachers' NOS understandings and their NOS teaching practices. The results of this study suggest that participation in ASREs may be one way to improve teachers' NOS understandings and teaching practices if the experiences themselves offer a comprehensive view of the NOS. Because ASREs and other science learning experiences do not always offer such experiences, pre-service teacher education and professional development opportunities may engage science teachers in two ways: (1) becoming part of a scientific community may enable them to teach with NOS and (2) being reflective about what being a scientist means may improve teachers' NOS understandings and better position them to teach about NOS.. Keywords: nature of science, authentic scientific research experiences, Next Generation Science Standards, teaching about NOS, teaching with NOS.

  3. Advancing the Perceptions of the Nature of Science (NOS): Integrating Teaching the NOS in a Science Content Course

    ERIC Educational Resources Information Center

    Aflalo, Ester

    2014-01-01

    Background: Understanding the nature of science (NOS) has been a key objective in teaching sciences for many years. Despite the importance of this goal it is, until this day, a complex challenge that we are far from achieving. Purpose: The study was conducted in order to further the understanding of the NOS amongst preservice teachers. It explores…

  4. Suggesting a NOS Map for Nature of Science for Science Education Instruction

    ERIC Educational Resources Information Center

    Oh, Jun-Young

    2017-01-01

    The aims of this research are 1) to explore the inter-relationships within the individual elements or tenets of Nature of Science (NOS), based on the dimensions of scientific knowledge in science learning, and 2) to consider Kuhn's concept of how scientific revolution takes place. This study suggests that instruction according to our NOS Flowchart…

  5. [Dynamic study of small metallic clusters]; Estudio Dinamico de Pequenos Agregados Metalicos

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lopez, M.J.; Jellinek, J.

    1995-12-31

    We present a brief introduction to computer simulation techniques (particularly to classical molecular dynamics) and their application to the study of the thermodynamic properties of a material system. The basic concepts are illustrated in the study of structural and energetic properties such as the liquid-solid transition and the fragmentation of small clusters of nickel. [Espanol] Presentamos una breve introducci{acute o}n de las t{acute e}cnicas de simulaci{acute o}n por ordenador (en particular de la Din{acute a}mica Molecular cl{acute a}sica) y de su aplicaci{acute o}n al estudio de las propiedades termodin{acute a}micas de un sistema material. Los conceptos b{acute a}sicos se ilustranmore » en el estudio de las propieades estructurales y energ{acute e}ticas, as{acute i} como de la transici{acute o}n de fase s{acute o}lido-l{acute i}quido y de las fragmentaciones de peque{tilde n}os agregados de n{acute i}quel.« less

  6. Using a Professional Development Program for Enhancing Chilean Biology Teachers' Understanding of Nature of Science (NOS) and Their Perceptions About Using History of Science to Teach NOS

    NASA Astrophysics Data System (ADS)

    Pavez, José M.; Vergara, Claudia A.; Santibañez, David; Cofré, Hernán

    2016-05-01

    A number of authors have recognized the importance of understanding the nature of science (NOS) for scientific literacy. Different instructional strategies such as decontextualized, hands-on inquiry, and history of science (HOS) activities have been proposed for teaching NOS. This article seeks to understand the contribution of HOS in enhancing biology teachers' understanding of NOS, and their perceptions about using HOS to teach NOS. These teachers ( N = 8), enrolled in a professional development program in Chile are, according to the national curriculum, expected to teach NOS, but have no specific NOS and HOS training. Teachers' views of NOS were assessed using the VNOS-D+ questionnaire at the beginning and at the end of two modules about science instruction and NOS. Both the pre- and the post-test were accompanied by interviews, and in the second session we collected information about teachers' perceptions of which interventions had been more significant in changing their views on NOS. Finally, the teachers also had to prepare a lesson plan for teaching NOS that included HOS. Some of the most important study results were: significant improvements were observed in teachers' understanding of NOS, although they assigned different levels of importance to HOS in these improvements; and although the teachers improved their understanding of NOS, most had difficulties in planning lessons about NOS and articulating historical episodes that incorporated NOS. The relationship between teachers' improved understanding of NOS and their instructional NOS skills is also discussed.

  7. Using a Professional Development Program for Enhancing Chilean Biology Teachers' Understanding of Nature of Science (NOS) and Their Perceptions about Using History of Science to Teach NOS

    ERIC Educational Resources Information Center

    Pavez, José M.; Vergara, Claudia A.; Santibañez, David; Cofré, Hernán

    2016-01-01

    A number of authors have recognized the importance of understanding the nature of science (NOS) for scientific literacy. Different instructional strategies such as decontextualized, hands-on inquiry, and history of science (HOS) activities have been proposed for teaching NOS. This article seeks to understand the contribution of HOS in enhancing…

  8. Elementary school science teachers' reflection for nature of science: Workshop of NOS explicit and reflective on force and motion learning activity

    NASA Astrophysics Data System (ADS)

    Patho, Khanittha; Yuenyong, Chokchai; Chamrat, Suthida

    2018-01-01

    The nature of science has been part of Thailand's science education curriculum since 2008. However, teachers lack of understanding about the nature of science (NOS) and its teaching, particularly element school science teachers. In 2012, the Science Institute of Thailand MOE, started a project of Elementary Science Teacher Professional Development to enhance their thinking about the Nature of Science. The project aimed to enhance teachers' understanding of NOS, science teaching for explicit and reflective NOS, with the aim of extending their understanding of NOS to other teachers. This project selected 366 educational persons. The group was made up of a teacher and a teacher supervisor from 183 educational areas in 74 provinces all Thailand. The project provided a one week workshop and a year's follow up. The week-long workshop consisted of 11 activities of science teaching for explicit reflection on 8 aspects of NOS. Workshop of NOS explicit and reflective on force and motion learning activity is one of eight activities. This activity provided participants to learn force and motion and NOS from the traditional toy "Bang-Poh". The activity tried to enhance participants to explicit NOS for 5 aspects including empirical basis, subjectivity, creativity, observation and inference, and sociocultural embeddedness. The explicit NOS worksheet provided questions to ask participants to reflect their existing ideas about NOS. The paper examines elementary school science teachers' understanding of NOS from the force and motion learning activity which provided explicit reflection on 5 NOS aspects. An interpretive paradigm was used to analyse the teachers' reflections in a NOS worksheet. The findings indicated that majority of them could reflect about the empirical basis of science and creativity but few reflected on observation and inference, or sociocultural embeddedness. The paper will explain the teachers' NOS thinking and discuss the further enhancing of their understanding

  9. The influence of explicit versus implicit instructional approaches during a technology-based curriculum on students' understanding of nature of science (NOS)

    NASA Astrophysics Data System (ADS)

    Al-Saidi, Ahmed Mohammad

    The purpose of this study was to examine the effect of an explicit versus an implicit instructional approach during technology-based curriculum on students' understanding of the nature of science (NOS) within an introductory biology course. The study emphasized the inferential and tentative nature of science. The intervention or explicit group was involved in inquiry activities followed by discussions that were directly geared towards the target aspects of NOS. The implicit group was engaged in the same activities but received instruction devoid of direct reference to the NOS aspects. Students in both groups spent identical amount of time on task. Selected items of the Views of Nature of Science Questionnaire (VNOS) together with semi-structured interviews were used to evaluate students' NOS conceptions before and at the end of the intervention, which lasted two weeks. A quantitative analysis using chi-square of students' pre-intervention NOS views as provided by the VNOS questionnaires revealed that there was not a statistically significant difference between implicit and explicit groups in both targeted NOS aspects, with (p = 0.18) and (p = 0.34) for inferential and tentative NOS, respectively. However the same analysis indicated statistical significance difference for post-intervention between implicit and explicit groups, yielding (p < 0.02) and (p < 0.002) for both inferential and tentative NOS, respectively. A qualitative analysis of students' pre and post-intervention views of the target aspects of NOS as well as semi-structured interviews for both groups was also conducted. Before intervention, the number of informed NOS responses in both groups was not considerably different. However, analysis of post-intervention NOS views indicated that more students in the explicit group demonstrated informed views of the NOS aspects than in the implicit group. Therefore, the analysis of the data indicated that, in this particular study, engaging students in inquiry

  10. The Development of In-Service Science Teachers' Understandings of and Orientations to Teaching the Nature of Science within a PCK-Based NOS Course

    ERIC Educational Resources Information Center

    Faikhamta, Chatree

    2013-01-01

    The nature of science (NOS) has become a central goal of science education in many countries. This study sought an understanding of the extent to which a nature of science course (NOSC), designed according to the conceptualization of pedagogical content knowledge (PCK) for teaching nature of science (NOS), affects in-service science teachers'…

  11. From Orthodoxy to Plurality in the Nature of Science (NOS) and Science Education: A Metacommentary

    ERIC Educational Resources Information Center

    Bazzul, Jesse

    2017-01-01

    This article provides a metacommentary on the special issue on nature of science (NOS). The issue is composed of senior scholars discussing Hodson and Wong's (2017, this issue) critique of the consensus view of nature of science, which on a basic level states that there are agreed-upon aspects of science that can be taught in K-12 schools. Each…

  12. Investigating inquiry beliefs and nature of science (NOS) conceptions of science teachers as revealed through online learning

    NASA Astrophysics Data System (ADS)

    Atar, Hakan Yavuz

    teachers NOS conceptions. Developing desired understanding of nature of science conceptions and having an adequate experience with inquiry learning is especially important for science teachers because science education literature suggests that the development of teachers' nature of science conceptions is influenced by their experiences with inquiry science (Akerson et. al. 2000) and implementation of science lessons reflect teachers' NOS conceptions (Abd-EL-Khalick & Boujaoude, 1997; Matson & Parsons, 1998; Rosenthal, 1993; Trowbridge, Bybee & Powell, 2000; Turner & Sullenger, 1999). Furthermore, the impediments to successful integration of inquiry based science instruction from teachers' perspective are particularly important, as they are the implementers of inquiry based science education reform. The purpose of this study is to understand the relationship between the teachers' NOS conceptions and their inquiry beliefs and practices in their classrooms and how this relationship impedes or contributes to the implementation of inquiry based science education reform efforts. The participants of this study were in-service teachers who were accepted into the online Masters Program in science education program at a southern university. Three online courses offered in the summer semester of 2005 constituted the research setting of this study: (1) Special Problems in the Teaching of Secondary School Science: Nature of Science & Science Teaching, (2) Curriculum in Science Education, and (3) Colloquium. Multiple data sources were used for data triangulation (Miles & Huberman, 1984; Yin, 1994) in order to understand the relationship between participants' NOS views and their conceptions and beliefs about inquiry-based science teaching. The study revealed that the relationship between the teachers' NOS conceptions and their inquiry beliefs and practices is far from being simple and linear. Data suggests that the teachers' sophistication of NOS conceptions influence their perception of

  13. The Development of Scientific Literacy through Nature of Science (NoS) within Inquiry Based Learning Approach

    NASA Astrophysics Data System (ADS)

    Widowati, A.; Widodo, E.; Anjarsari, P.; Setuju

    2017-11-01

    Understanding of science instructional leading to the formation of student scientific literacy, seems not yet fully understood well by science teachers. Because of this, certainly needs to be reformed because science literacy is a major goal in science education for science education reform. Efforts of development science literacy can be done by help students develop an information conception of the Nature of Science (NoS) and apply inquiry approach. It is expected that students’ science literacy can develop more optimal by combining NoS within inquiry approach. The purpose of this research is to produce scientific literacy development model of NoS within inquiry-based learning. The preparation of learning tools will be maked through Research and Development (R & D) following the 4-D model (Define, Design, Develop, and Disseminate) and Borg & Gall. This study is a follow-up of preliminary research results about the inquiry profile of junior high school students indicating that most categories are quite good. The design of the model NoS within inquiry approach for developing scientific literacy is using MER Model in development educational reconstruction. This research will still proceed to the next stage that is Develop.

  14. Thai primary students' understanding of nature of science (NOS) in learning about force and motion for explicit NOS through STS approach

    NASA Astrophysics Data System (ADS)

    Jimakorn, Narakorn; Yuenyong, Chokchai

    2018-01-01

    This paper aimed to study of primary school students' understanding of nature of science in learning about force and motion for Explicit Nature of Science through science technology and society (STS) approach. Participants were 11 Grade 5 students who study in Baan Khongtaphet, Bothong, Chonburi, Thailand. This research regarded interpretive paradigm. The intervention of STS physics provided 4 weeks of teaching about force and motion through Yuenyong (2006) science technology and society (STS) approach. The issues of making skate board was brought into the class in order to enhance students learning about force and motion and applying knowledge for designing skate board. The intervention was also designed to allow students explicitly mentioning their ideas about nature of science related to learning activities of STS force and motion. Students' understanding of nature of science was interpreted through students' worksheets, participant observation, students' journal writing and informal interview. The findings revealed that majority of students could reflect their ideas related to many aspects of nature of science. This included Science demands and relies on empirical evidence; knowledge production in science shares many common factors and shared habits of mind, norms, logical thinking and methods; tentative of scientific knowledge; historical, cultural and social influences on science; historical, cultural and social influences on science; science and its methods cannot answer all questions. The study has implications for NOS teaching in Thailand primary school.

  15. Science learning based on local potential: Overview of the nature of science (NoS) achieved

    NASA Astrophysics Data System (ADS)

    Wilujeng, Insih; Zuhdan Kun, P.; Suryadarma, IGP.

    2017-08-01

    The research concerned here examined the effectiveness of science learning conducted with local potential as basis from the point of a review of the NoS (nature of science) achieved. It used the non equivalent control group design and took place in the regions of Magelang and Pati, Province of Central Java, and the regions of Bantul and Sleman, Province of the Special Region of Yogyakarta. The research population consisted of students of the first and second grades at each junior high school chosen with research subjects sampled by means of cluster sampling. The instruments used included: a) an observation sheet, b) a written test, and c) a questionnaire. The learning and research instruments had been declared valid and reliable according to previous developmental research. In conclusion, the science learning based on local potential was effective in terms of all the NoS aspects.

  16. Applying innovative approach “Nature of Science (NoS) within inquiry” for developing scientific literacy in the student worksheet

    NASA Astrophysics Data System (ADS)

    Widowati, A.; Anjarsari, P.; Zuhdan, K. P.; Dita, A.

    2018-03-01

    The challenges of the 21st century require innovative solutions. Education must able to make an understanding of science learning that leads to the formation of scientific literacy learners. This research was conducted to produce the prototype as science worksheet based on Nature of Science (NoS) within inquiry approach and to know the effectiveness its product for developing scientific literacy. This research was the development and research design, by pointing to Four D models and Borg & Gall Model. There were 4 main phases (define, design, develop, disseminate) and additional phases (preliminary field testing, main product revision, main field testing, and operational product revision). Research subjects were students of the junior high school in Yogyakarta. The instruments used included questionnaire sheet product validation and scientific literacy test. For the validation data were analyzed descriptively. The test result was analyzed by an N-gain score. The results showed that the appropriateness of worksheet applying NoS within inquiry-based learning approach is eligible based on the assessment from excellent by experts and teachers, students’ scientific literacy can improve high category of the N-gain score at 0.71 by using student worksheet with Nature of Science (NoS) within inquiry approach.

  17. Low shear stress induces vascular eNOS uncoupling via autophagy-mediated eNOS phosphorylation.

    PubMed

    Zhang, Jun-Xia; Qu, Xin-Liang; Chu, Peng; Xie, Du-Jiang; Zhu, Lin-Lin; Chao, Yue-Lin; Li, Li; Zhang, Jun-Jie; Chen, Shao-Liang

    2018-05-01

    Uncoupled endothelial nitric oxide synthase (eNOS) produces O 2 - instead of nitric oxide (NO). Earlier, we reported rapamycin, an autophagy inducer and inhibitor of cellular proliferation, attenuated low shear stress (SS) induced O 2 - production. Nevertheless, it is unclear whether autophagy plays a critical role in the regulation of eNOS uncoupling. Therefore, this study aimed to investigate the modulation of autophagy on eNOS uncoupling induced by low SS exposure. We found that low SS induced endothelial O 2 - burst, which was accompanied by reduced NO release. Furthermore, inhibition of eNOS by L-NAME conspicuously attenuated low SS-induced O 2 - releasing, indicating eNOS uncoupling. Autophagy markers such as LC3 II/I ratio, amount of Beclin1, as well as ULK1/Atg1 were increased during low SS exposure, whereas autophagic degradation of p62/SQSTM1 was markedly reduced, implying impaired autophagic flux. Interestingly, low SS-induced NO reduction could be reversed by rapamycin, WYE-354 or ATG5 overexpression vector via restoration of autophagic flux, but not by N-acetylcysteine or apocynin. eNOS uncoupling might be ascribed to autophagic flux blockade because phosphorylation of eNOS Thr495 by low SS or PMA stimulation was also regulated by autophagy. In contrast, eNOS acetylation was not found to be regulated by low SS and autophagy. Notably, although low SS had no influence on eNOS Ser1177 phosphorylation, whereas boosted eNOS Ser1177 phosphorylation by rapamycin were in favor of the eNOS recoupling through restoration of autophagic flux. Taken together, we reported a novel mechanism for regulation of eNOS uncoupling by low SS via autophagy-mediated eNOS phosphorylation, which is implicated in geometrical nature of atherogenesis. Copyright © 2018 Elsevier B.V. All rights reserved.

  18. Using the Lens of Pedagogical Content Knowledge for Teaching the Nature of Science to Portray Novice Chemistry Teachers' Transforming NOS in Early Years of Teaching Profession

    ERIC Educational Resources Information Center

    Supprakob, Surayot; Faikhamta, Chatree; Suwanruji, Potjanart

    2016-01-01

    Pedagogical content knowledge for teaching the nature of science (PCK for NOS) has attracted interest in recent decades. This study investigated the PCK for NOS of six novice chemistry teachers with various educational backgrounds. An interpretive case study was performed. Multiple data sources including classroom observations, field notes,…

  19. Nature of Science Contextualized: Studying Nature of Science with Scientists

    ERIC Educational Resources Information Center

    Tala, Suvi; Vesterinen, Veli-Matti

    2015-01-01

    Understanding nature of science (NOS) is widely considered an important educational objective and views of NOS are closely linked to science teaching and learning. Thus there is a lively discussion about what understanding NOS means and how it is reached. As a result of analyses in educational, philosophical, sociological and historical research,…

  20. Pedagogical Reflections by Secondary Science Teachers at Different NOS Implementation Levels

    ERIC Educational Resources Information Center

    Herman, Benjamin C.; Clough, Michael P.; Olson, Joanne K.

    2017-01-01

    This study investigated what 13 secondary science teachers at various nature of science (NOS) instruction implementation levels talked about when they reflected on their teaching. We then determined if differences exist in the quality of those reflections between high, medium, and low NOS implementers. This study sought to answer the following…

  1. Pedagogical Reflections by Secondary Science Teachers at Different NOS Implementation Levels

    NASA Astrophysics Data System (ADS)

    Herman, Benjamin C.; Clough, Michael P.; Olson, Joanne K.

    2017-02-01

    This study investigated what 13 secondary science teachers at various nature of science (NOS) instruction implementation levels talked about when they reflected on their teaching. We then determined if differences exist in the quality of those reflections between high, medium, and low NOS implementers. This study sought to answer the following questions: (1) What do teachers talk about when asked general questions about their pedagogy and NOS pedagogy and (2) what qualitative differences, if any, exist within variables across teachers of varying NOS implementation levels? Evidence derived from these teachers' reflections indicated that self-efficacy and perceptions of general importance for NOS instruction were poor indicators of NOS implementation. However, several factors were associated with the extent that these teachers implemented NOS instruction, including the utility value they hold for NOS teaching, considerations of how people learn, understanding of NOS pedagogy, and their ability to accurately and deeply self-reflect about teaching. Notably, those teachers who effectively implemented the NOS at higher levels value NOS instruction for reasons that transcend immediate instructional objectives. That is, they value teaching NOS for achieving compelling ends realized long after formal schooling (e.g., lifelong socioscientific decision-making for civic reasons), and they deeply reflect about how to teach NOS by drawing from research about how people learn. Low NOS implementers' simplistic notions and reflections about teaching and learning appeared to be impeding factors to accurate and consistent NOS implementation. This study has implications for science teacher education efforts that promote NOS instruction.

  2. MGE-derived nNOS+ interneurons promote fear acquisition in nNOS-/- mice.

    PubMed

    Zhang, Lin; Yuan, Hong-Jin; Cao, Bo; Kong, Cheng-Cheng; Yuan, Fang; Li, Jun; Ni, Huan-Yu; Wu, Hai-Yin; Chang, Lei; Liu, Yan; Luo, Chun-Xia

    2017-12-02

    Neuronal nitric oxide synthase (nNOS) 1 , mainly responsible for NO release in central nervous system (CNS) 2 , plays a significant role in multiple physiological functions. However, the function of nNOS + interneurons in fear learning has not been much explored. Here we focused on the medial ganglionic eminences (MGE) 3 -derived nNOS + interneurons in fear learning. To determine the origin of nNOS + interneurons, we cultured neurons in vitro from MGE, cortex, lateral ganglionic eminence (LGE) 4 , caudal ganglionic eminences (CGE) 5 and preoptic area (POA) 6 . The results showed that MGE contained the most abundant precursors of nNOS + interneurons. Moreover, donor cells from E12.5 embryos demonstrated the highest positive rate of nNOS + interneurons compared with other embryonic periods (E11.5, E12, E13, E13.5 and E14). Additionally, these cells from E12.5 embryos showed long axonal and abundant dendritic arbors after 10 days culture, indicating the capability to disperse and integrate in host neural circuits after transplantation. To investigate the role of MGE-derived nNOS + interneurons in fear learning, donor MGE cells were transplanted into dentate gyrus (DG) 7 of nNOS knock-out (nNOS -/- ) or wild-type mice. Results showed that the transplantation of MGE cells promoted the acquisition of nNOS -/- but not the wild-type mice, suggesting the importance of nNOS + neurons in fear acquisition. Moreover, we transplanted MGE cells from nNOS -/- mice or wild-type mice into DG of the nNOS -/- mice and found that only MGE cells from wild-type mice but not the nNOS -/- mice rescued the deficit in acquisition of the nNOS -/- mice, further confirming the positive role of nNOS + neurons in fear learning. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Development and Nature of Preservice Chemistry Teachers' Pedagogical Content Knowledge for Nature of Science

    NASA Astrophysics Data System (ADS)

    Demirdöğen, Betül; Hanuscin, Deborah L.; Uzuntiryaki-Kondakci, Esen; Köseoğlu, Fitnat

    2016-08-01

    The purpose of this case study is to delve into the complexities of the early development of preservice chemistry teachers' science teaching orientations, knowledge of learners, knowledge of instructional strategies, and knowledge of assessment during a two-semester intervention designed to enhance their pedagogical content knowledge (PCK) for teaching nature of science (NOS). Thirty preservice chemistry teachers enrolled in a Research in Science Education course participated in the study. Qualitative data sources included responses to an open-ended instrument, interviews, observations, and artifacts such as lesson plans and reflection papers. Through the in-depth analysis of explicit PCK and constant comparative method of analysis, we identified the influence of the intervention on participants' PCK for NOS. Analysis of data revealed four major themes related to the nature of preservice chemistry teachers' NOS teaching practices and their PCK for NOS: (1) prerequisite knowledge and beliefs are necessary to teach NOS, (2) there is a developmental progression of PCK for NOS from knowledge to application level, (3) teachers need some comfort in their NOS understanding to teach NOS, and (4) the higher integration of PCK components leads to successful NOS teaching practices. Implications for science teacher education and research are discussed.

  4. Nature of Science or Nature of the Sciences?

    ERIC Educational Resources Information Center

    Schizas, Dimitrios; Psillos, Dimitris; Stamou, George

    2016-01-01

    The present essay examines the emerging issue of domain-general versus domain-specific nature of science (NOS) understandings from a perspective that illuminates the value of domain-specific philosophies of science for the growth and development of the NOS educational field. Under the assumption that individual sciences do have their own…

  5. Comparison of Views of the Nature of Science between Natural Science and Nonscience Majors

    ERIC Educational Resources Information Center

    Desaulniers Miller, Marie C.; Montplaisir, Lisa M.; Offerdahl, Erika G.; Cheng, Fu-Chih; Ketterling, Gerald L.

    2010-01-01

    Science educators have the common goal of helping students develop scientific literacy, including understanding of the nature of science (NOS). University faculties are challenged with the need to develop informed NOS views in several major student subpopulations, including science majors and nonscience majors. Research into NOS views of…

  6. Identifying Demographic Variables Influencing the Nature of Science (NOS) Conceptions of Teachers

    ERIC Educational Resources Information Center

    Karaman, Ayhan

    2017-01-01

    In this survey research study, the views of practicing teachers in select aspects of NOS were investigated in connection with the effects of several variables (teaching discipline, gender, education level, teaching experience and regional work location). The instrument used to collect data was an adapted version of "Scientific Epistemological…

  7. Student conceptions of the nature of science

    NASA Astrophysics Data System (ADS)

    Talbot, Amanda L.

    Research has shown that students from elementary school to college have major misconceptions about the nature of science. While an appropriate understanding of the nature of science has been an objective of science education for a century, researchers using a variety of instruments, continue to document students' inadequate conceptions of what science is and how it operates as an enterprise. Current research involves methods to improve student understanding of the nature of science. Students often misunderstand the creative, subjective, empirical, and tentative nature of science. They do not realize the relationship between laws and theories, nor do they understand that science does not follow a prescribed method. Many do not appreciate the influence culture, society, and politics; nor do they have an accurate understanding of the types of questions addressed by science. This study looks at student understanding of key nature of science (NOS) concepts in order to examine the impact of implementing activities intended to help students better understand the process of science and to see if discussion of key NOS concepts following those activities will result in greater gains in NOS understanding. One class received an "activities only" treatment, while the other participated in the same activities followed by explicit discussion of key NOS themes relating to the activity. The interventions were implemented for one school year in two high school anatomy and physiology courses composed of juniors and seniors. Student views of the nature of science were measured using the Views of the Nature of Science-Form C (VNOS-C). Students in both classes demonstrated significant gains in NOS understanding. However, contrary to current research, the addition of explicit discussion did not result in significantly greater gains in NOS understanding. This suggests that perhaps students in higher-level science classes can draw the correlations between NOS related activities and

  8. Does the nature of science influence college students' learning of biological evolution?

    NASA Astrophysics Data System (ADS)

    Butler, Wilbert, Jr.

    This quasi-experimental, mixed-methods study assessed the influence of the nature of science (NOS) instruction on college students' learning of biological evolution. In this research, conducted in two introductory biology courses, in each course the same instruction was employed, with one important exception: in the experimental section students were involved in an explicit, reflective treatment of the nature of science (Explicit, reflective NOS), in the traditional treatment section, NOS was implicitly addressed (traditional treatment). In both sections, NOS aspects of science addressed included is tentative, empirically based, subjective, inferential, and based on relationship between scientific theories and laws. Students understanding of evolution, acceptance of evolution, and understanding of the nature of science were assessed before, during and after instruction. Data collection entailed qualitative and quantitative methods including Concept Inventory for Natural Selection (CINS), Measure of Acceptance of the Theory of Evolution (MATE) survey, Views of nature of Science (VNOS-B survey), as well as interviews, classroom observations, and journal writing to address understand students' views of science and understanding and acceptance of evolution. The quantitative data were analyzed via inferential statistics and the qualitative data were analyzed using grounded theory. The data analysis allowed for the construction and support for four assertions: Assertion 1: Students engaged in explicit and reflective NOS specific instruction significantly improved their understanding of the nature of science concepts. Alternatively, students engaged in instruction using an implicit approach to the nature of science did not improve their understanding of the nature of science to the same degree. The VNOS-B results indicated that students in the explicit, reflective NOS class showed the better understanding of the NOS after the course than students in the implicit NOS class

  9. Rerouting the Pathway for the Biosynthesis of the Side Ring System of Nosiheptide: The Roles of NosI, NosJ, and NosK

    PubMed Central

    2017-01-01

    Nosiheptide (NOS) is a highly modified thiopeptide antibiotic that displays formidable in vitro activity against a variety of Gram-positive bacteria. In addition to a central hydroxypyridine ring, NOS contains several other modifications, including multiple thiazole rings, dehydro-amino acids, and a 3,4-dimethylindolic acid (DMIA) moiety. The DMIA moiety is required for NOS efficacy and is synthesized from l-tryptophan in a series of reactions that have not been fully elucidated. Herein, we describe the role of NosJ, the product of an unannotated gene in the biosynthetic operon for NOS, as an acyl carrier protein that delivers 3-methylindolic acid (MIA) to NosK. We also reassign the role of NosI as the enzyme responsible for catalyzing the ATP-dependent activation of MIA and MIA’s attachment to the phosphopantetheine moiety of NosJ. Lastly, NosK catalyzes the transfer of the MIA group from NosJ-MIA to a conserved serine residue (Ser102) on NosK. The X-ray crystal structure of NosK, solved to 2.3 Å resolution, reveals that the protein is an α/β-fold hydrolase. Ser102 interacts with Glu210 and His234 to form a catalytic triad located at the bottom of an open cleft that is large enough to accommodate the thiopeptide framework. PMID:28343381

  10. Exploring Natural and Social Scientists' Views of Nature of Science

    ERIC Educational Resources Information Center

    Bayir, Eylem; Cakici, Yilmaz; Ertas, Ozge

    2014-01-01

    Science education researchers recently turned their attention to exploring views about nature of science (NOS). A large body of research indicates that both students and teachers have many naïve views about the NOS. Unfortunately, less attention has been directed at the issue of exploring the views of the scientists. Also, the little research in…

  11. Going beyond the Consensus View: Broadening and Enriching the Scope of NOS-Oriented Curricula

    ERIC Educational Resources Information Center

    Hodson, Derek; Wong, Siu Ling

    2017-01-01

    Nature of science (NOS) is now a well-established focus of science education and a key element in defining scientific literacy. In recent years, a particular specification of NOS, often described as "the consensus view," has become very influential and has gained ready acceptance in many countries around the world as a template for…

  12. When Nature of Science Meets Marxism: Aspects of Nature of Science Taught by Chinese Science Teacher Educators to Prospective Science Teachers

    NASA Astrophysics Data System (ADS)

    Wan, Zhi Hong; Wong, Siu Ling; Zhan, Ying

    2013-05-01

    Nature of science (NOS) is beginning to find its place in the science education in China. In a study which investigated Chinese science teacher educators' conceptions of teaching NOS to prospective science teachers through semi-structured interviews, five key dimensions emerged from the data. This paper focuses on the dimension, NOS content to be taught to prospective science teachers. Among a total of twenty NOS elements considered by the Chinese science teacher educators to be important ideas to be taught, five were suggested by no less than a half of the educators. They are (1) empirical basis of scientific investigation, (2) logics in scientific investigation, (3) general process of scientific investigation, (4) progressive nature of scientific knowledge, and (5) realist views of mind and natural world. This paper discusses the influence of Marxism, a special socio-cultural factor in China, on Chinese science teacher educators' conceptions of NOS content to be taught to prospective science teachers. We argue the importance of considering ideological traditions (mainly those in general philosophy and religion) when interpreting views of NOS or its content to be taught in different countries and regions and understanding students' conceptual ecology of learning NOS.

  13. Exploring How Second Grade Elementary Teachers Translate Their Nature of Science Views into Classroom Practice After a Graduate Level Nature of Science Course

    NASA Astrophysics Data System (ADS)

    Deniz, Hasan; Adibelli, Elif

    2015-12-01

    The main purpose of this study was to explore the factors mediating the translation of second grade teachers' nature of science (NOS) views into classroom practice after completing a graduate level NOS course. Four second grade in-service elementary teachers comprised the sample of this study. Data were collected from several sources during the course of this study. The primary data sources were (a) assessment of the elementary teachers' NOS views before and after the graduate level NOS course using the Views of Nature of Science Questionnaire Version B (VNOS-B) (Lederman et al., 2002) coupled with interviews, and (b) a classroom observation and videotaped recording of the elementary teachers' best NOS lessons coupled with interview. We identified three distinct but related factors that mediated the translation of NOS views into classroom practice: the teachers' perspectives about the developmental appropriateness of the NOS aspect, the teachers' selection of target NOS aspects, and the relative importance placed by teachers on each NOS aspect.

  14. Characteristics of colonic migrating motor complexes in neuronal NOS (nNOS) knockout mice.

    PubMed

    Spencer, Nick J

    2013-01-01

    It is well established that the intrinsic pacemaker mechanism that generates cyclical colonic migrating motor complexes (CMMCs) does not require endogenous nitric oxide (NO). However, pharmacological blockade of endogenous NO production potently increases the frequency of CMMCs, suggesting that endogenous NO acts normally to inhibit the CMMC pacemaker mechanism. In this study, we investigated whether mice with a life long genetic deletion of the neuronal nitric oxide synthase (nNOS) gene would show similar CMMC characteristics as wild type mice that have endogenous NO production acutely inhibited. Intracellular electrophysiological and mechanical recordings were made from circular muscle cells of isolated whole mouse colon in wild type and nNOS knockout (KO) mice at 35°C. In wild type mice, the NOS inhibitor, L-NA (100 μM) caused a significant increase in CMMC frequency and a significant depolarization of the CM layer. However, unexpectedly, the frequency of CMMCs in nNOS KO mice was not significantly different from control mice. Also, the resting membrane potential of CM cells in nNOS KO mice was not depolarized compared to controls; and the amplitude of the slow depolarization phase underlying MCs was of similar amplitude between KO and wild type offspring. These findings show that in nNOS KO mice, the major characteristics of CMMCs and their electrical correlates are, at least in adult mice, indistinguishable from wild type control offspring. One possibility why the major characteristics of CMMCs were no different between both types of mice is that nNOS KO mice may compensate for their life long deletion of the nNOS gene, and their permanent loss of neuronal NO production. In this regard, we suggest caution should be exercised when assuming that data obtained from adult nNOS KO mice can be directly extrapolated to wild type mice, that have been acutely exposed to an inhibitor of NOS.

  15. mNos2 deletion and human NOS2 replacement in Alzheimer disease models.

    PubMed

    Colton, Carol A; Wilson, Joan G; Everhart, Angela; Wilcock, Donna M; Puoliväli, Jukka; Heikkinen, Taneli; Oksman, Juho; Jääskeläinen, Olli; Lehtimäki, Kimmo; Laitinen, Teemu; Vartiainen, Nina; Vitek, Michael P

    2014-08-01

    Understanding the pathophysiologic mechanisms underlying Alzheimer disease relies on knowledge of disease onset and the sequence of development of brain pathologies. We present a comprehensive analysis of early and progressive changes in a mouse model that demonstrates a full spectrum of characteristic Alzheimer disease-like pathologies. This model demonstrates an altered immune redox state reminiscent of the human disease and capitalizes on data indicating critical differences between human and mouse immune responses, particularly in nitric oxide levels produced by immune activation of the NOS2 gene. Using the APPSwDI(+)/(+)mNos2(-/-) (CVN-AD) mouse strain, we show a sequence of pathologic events leading to neurodegeneration,which include pathologically hyperphosphorylated tau in the perforant pathway at 6 weeks of age progressing to insoluble tau, early appearance of β-amyloid peptides in perivascular deposits around blood vessels in brain regions known to be vulnerable to Alzheimer disease, and progression to damage and overt loss in select vulnerable neuronal populations in these regions. The role of species differences between hNOS2 and mNos2 was supported by generating mice in which the human NOS2 gene replaced mNos2. When crossed with CVN-AD mice, pathologic characteristics of this new strain (APPSwDI(+)/(-)/HuNOS2(tg+)/(+)/mNos2(-/-)) mimicked the pathologic phenotypes found in the CVN-AD strain.

  16. Views of nature of science questionnaire: Toward valid and meaningful assessment of learners' conceptions of nature of science

    NASA Astrophysics Data System (ADS)

    Lederman, Norm G.; Abd-El-Khalick, Fouad; Bell, Randy L.; Schwartz, Renée S.

    2002-08-01

    Helping students develop informed views of nature of science (NOS) has been and continues to be a central goal for kindergarten through Grade 12 (K-12) science education. Since the early 1960s, major efforts have been undertaken to enhance K-12 students and science teachers' NOS views. However, the crucial component of assessing learners' NOS views remains an issue in research on NOS. This article aims to (a) trace the development of a new open-ended instrument, the Views of Nature of Science Questionnaire (VNOS), which in conjunction with individual interviews aims to provide meaningful assessments of learners' NOS views; (b) outline the NOS framework that underlies the development of the VNOS; (c) present evidence regarding the validity of the VNOS; (d) elucidate the use of the VNOS and associated interviews, and the range of NOS aspects that it aims to assess; and (e) discuss the usefulness of rich descriptive NOS profiles that the VNOS provides in research related to teaching and learning about NOS. The VNOS comes in response to some calls within the science education community to go back to developing standardized forced-choice paper and pencil NOS assessment instruments designed for mass administrations to large samples. We believe that these calls ignore much of what was learned from research on teaching and learning about NOS over the past 30 years. The present state of this line of research necessitates a focus on individual classroom interventions aimed at enhancing learners' NOS views, rather than on mass assessments aimed at describing or evaluating students' beliefs.

  17. Demystifying Nature of Science

    ERIC Educational Resources Information Center

    Lederman, Judith; Bartels, Selina; Lederman, Norman; Gnanakkan, Dionysius

    2014-01-01

    With the emergence of the "Next Generation Science Standards" ("NGSS"; NGSS Lead States 2013), it is apparent that teaching and learning about nature of science (NOS) continues to be an important goal of science education for all K-12 students. With this emphasis on NOS, early childhood teachers are asking how to design…

  18. The return of the Scarlet Pimpernel: cobalamin in inflammation II — cobalamins can both selectively promote all three nitric oxide synthases (NOS), particularly iNOS and eNOS, and, as needed, selectively inhibit iNOS and nNOS

    PubMed Central

    Wheatley, Carmen

    2007-01-01

    The up-regulation of transcobalamins [hitherto posited as indicating a central need for cobalamin (Cbl) in inflammation], whose expression, like inducible nitric oxide synthase (iNOS), is Sp1- and interferondependent, together with increased intracellular formation of glutathionylcobalamin (GSCbl), adenosylcobalamin (AdoCbl), methylcobalamin (MeCbl), may be essential for the timely promotion and later selective inhibition of iNOS and concordant regulation of endothelial and neuronal NOS (eNOS/nNOS.) Cbl may ensure controlled high output of nitric oxide (NO) and its safe deployment, because: (1) Cbl is ultimately responsible for the synthesis or availability of the NOS substrates and cofactors heme, arginine, BH4 flavin adenine dinucleotide/flavin mononucleotide (FAD/FMN) and NADPH, via the far-reaching effects of the two Cbl coenzymes, methionine synthase (MS) and methylmalonyl CoA mutase (MCoAM) in, or on, the folate, glutathione, tricarboxylic acid (TCA) and urea cycles, oxidative phosphorylation, glycolysis and the pentose phosphate pathway. Deficiency of any of theNOS substrates and cofactors results in ‘uncoupled’ NOS reactions, decreasedNO production and increased or excessive O2−, H2O2, ONOO− and other reactive oxygen species (ROS), reactive nitric oxide species (RNIS) leading to pathology. (2) Cbl is also the overlooked ultimate determinant of positive glutathione status, which favours the formation of more benign NO species, s-nitrosothiols, the predominant form in which NO is safely deployed. Cbl status may consequently act as a ‘back-up disc’ that ensures the active status of antioxidant systems, as well as reversing and modulating the effects of nitrosylation in cell signal transduction.New evidence shows that GSCbl can significantly promote iNOS/ eNOS NO synthesis in the early stages of inflammation, thus lowering high levels of tumour necrosis factor-a that normally result in pathology, while existing evidence shows that in extreme

  19. Working with the Nature of Science in Physics Class: Turning "Ordinary" Classroom Situations into Nature of Science Learning Situations

    ERIC Educational Resources Information Center

    Hansson, Lena; Leden, Lotta

    2016-01-01

    In the science education research field there is a large body of literature on the "nature of science" (NOS). NOS captures issues about what characterizes the research process as well as the scientific knowledge. Here we, in line with a broad body of literature, use a wide definition of NOS including also e.g. socio-cultural aspects. It…

  20. When Nature of Science Meets Marxism: Aspects of Nature of Science Taught by Chinese Science Teacher Educators to Prospective Science Teachers

    ERIC Educational Resources Information Center

    Wan, Zhi Hong; Wong, Siu Ling; Zhan, Ying

    2013-01-01

    Nature of science (NOS) is beginning to find its place in the science education in China. In a study which investigated Chinese science teacher educators' conceptions of teaching NOS to prospective science teachers through semi-structured interviews, five key dimensions emerged from the data. This paper focuses on the dimension, "NOS content…

  1. Embedding Nature of Science in Teaching about Astronomy and Space

    ERIC Educational Resources Information Center

    Buaraphan, Khajornsak

    2012-01-01

    Science teachers need an adequate understanding of nature of science (NOS) and the ability to embed NOS in their teaching. This collective case study aims to explore in-service science teachers' conceptions of NOS and the embeddedness of NOS in their teaching about astronomy and space. Three science teachers participated in this study. All…

  2. Integrating the Nature of Science

    ERIC Educational Resources Information Center

    Weiland, Ingrid; Blieden, Katherine; Akerson, Valarie

    2014-01-01

    The nature of science (NOS) describes what science is and how knowledge in science is developed (NSTA 2013). To develop elementary students' understandings of how scientists explore the world, the authors--an education professor and a third-grade teacher--endeavored to integrate NOS into a third-grade life science unit. Throughout the lesson,…

  3. Teaching the "Nature of Science": Modest Adaptations or Radical Reconceptions?

    ERIC Educational Resources Information Center

    Hipkins, Rosemary; Barker, Miles; Bolstad, Rachel

    2005-01-01

    This article explores the nature of a continuing mismatch between curriculum reform rhetoric in science education and actual classroom practice. Lack of philosophical consensus about the nature of science (NOS); lack of appropriate curriculum guidance, classroom materials and pedagogical content knowledge for NOS teaching; teachers' personal…

  4. A Framework for Guiding Future Citizens to Think Critically about Nature of Science and Socioscientific Issues

    ERIC Educational Resources Information Center

    Yacoubian, Hagop A.

    2015-01-01

    In this article, I introduce a framework for guiding future citizens to think critically about nature of science (NOS) and "with" NOS as they engage in socioscientific decision making. The framework, referred to as the critical thinking--nature of science (CT-NOS) framework, explicates and targets both NOS as a learning objective and NOS…

  5. Teachers' Ways of Talking about Nature of Science and Its Teaching

    ERIC Educational Resources Information Center

    Leden, Lotta; Hansson, Lena; Redfors, Andreas; Ideland, Malin

    2015-01-01

    Nature of science (NOS) has for a long time been regarded as a key component in science teaching. Much research has focused on students' and teachers' views of NOS, while less attention has been paid to teachers' perspectives on NOS teaching. This article focuses on in-service science teachers' ways of talking about NOS and NOS teaching, e.g. what…

  6. Towards a Philosophically and a Pedagogically Reasonable Nature of Science Curriculum

    NASA Astrophysics Data System (ADS)

    Yacoubian, Hagop Azad

    This study, primarily theoretical in nature, explores a philosophically and pedagogically reasonable way of addressing nature of science (NOS) in school science. NOS encompasses what science is and how scientific knowledge develops. I critically evaluate consensus frameworks of NOS in school science, which converge contentious philosophical viewpoints into general NOS-related ideas. I argue that they (1) lack clarity in terms of how NOS-related ideas could be applied for various ends, (2) portray a distorted image of the substantive content of NOS and the process of its development, and (3) lack a developmental trajectory for how to address NOS at different grade levels. As a remedy to these problems, I envision a NOS curriculum that (1) explicates and targets both NOS as an educational end and NOS as a means for socioscientific decision making, (2) has critical thinking as its foundational pillar, and (3) provides a developmental pathway for NOS learning using critical thinking as a progression unit. Next, I illustrate a framework for addressing NOS in school science referred to as the critical thinking—nature of science (CT-NOS) framework. This framework brings together the first two of the three elements envisioned in the NOS curriculum. I address the third element by situating the CT-NOS framework in a developmental context, borrowing from the literature on learning progressions in science and using critical thinking as a progression unit. Finally, I present an empirical study of experienced secondary science teachers’ views of a NOS lesson prepared using the CT-NOS framework. The teachers attended a professional development workshop at which the lesson, and the characteristics of the CT-NOS framework, were presented. The analysis of the qualitative data revealed that most teachers found the lesson to be somewhat feasible for a secondary science classroom, useful or somewhat useful to their students, and interesting. The teachers focused on 14 features of

  7. Comparison of views of the nature of science between natural science and nonscience majors.

    PubMed

    Miller, Marie C Desaulniers; Montplaisir, Lisa M; Offerdahl, Erika G; Cheng, Fu-Chih; Ketterling, Gerald L

    2010-01-01

    Science educators have the common goal of helping students develop scientific literacy, including understanding of the nature of science (NOS). University faculties are challenged with the need to develop informed NOS views in several major student subpopulations, including science majors and nonscience majors. Research into NOS views of undergraduates, particularly science majors, has been limited. In this study, NOS views of undergraduates in introductory environmental science and upper-level animal behavior courses were measured using Likert items and open-ended prompts. Analysis revealed similarities in students' views between the two courses; both populations held a mix of naïve, transitional, and moderately informed views. Comparison of pre- and postcourse mean scores revealed significant changes in NOS views only in select aspects of NOS. Student scores on sections addressing six aspects of NOS were significantly different in most cases, showing notably uninformed views of the distinctions between scientific theories and laws. Evidence-based insight into student NOS views can aid in reforming undergraduate science courses and will add to faculty and researcher understanding of the impressions of science held by undergraduates, helping educators improve scientific literacy in future scientists and diverse college graduates.

  8. Impact of historical science short stories on students' attitudes and NOS understanding

    NASA Astrophysics Data System (ADS)

    Hall, Garrett

    This study examines the impact of historical short stories on upper and lower level high school chemistry students in the second semester of a two-semester course at a large Midwestern suburban school. Research focused on improved understanding of six fundamental nature of science (NOS) concepts made explicit in the stories, recollection of historical examples from the stories that supported student NOS thinking; student attitudes toward historical stories in comparison to traditional textbook readings as well as student attitudes regarding scientists and the development of science ideas. Data collection included surveys over six NOS concepts, attitudes towards science and reading, and semi-structured interviews. Analysis of the data collected in this study indicated significant increases in understanding for three of the six NOS concepts within the upper-level students and one of the six concepts for lower level students. Students were able to draw upon examples from the stories to defend their NOS views but did so more frequently when responding verbally in comparison to written responses on the surveys. The analysis also showed that students in both levels would rather utilize historical short stories over a traditional textbook and found value in learning about scientists and how scientific ideas are developed.

  9. Pre-Service Physics Teachers' Conceptions of Nature of Science

    ERIC Educational Resources Information Center

    Buaraphan, Khajornsak

    2011-01-01

    Understanding of NOS (nature of science) appears as a prerequisite of a scientifically literate person. Promoting adequate understanding of NOS in pre-service physics teachers is, therefore, an important task of science educators. Before doing that, science educators must have information concerning their pre-service teachers' conceptions of NOS.…

  10. Therapeutic effect of enhancing endothelial nitric oxide synthase (eNOS) expression and preventing eNOS uncoupling

    PubMed Central

    Förstermann, Ulrich; Li, Huige

    2011-01-01

    Nitric oxide (NO) produced by the endothelium is an important protective molecule in the vasculature. It is generated by the enzyme endothelial NO synthase (eNOS). Similar to all NOS isoforms, functional eNOS transfers electrons from nicotinamide adenine dinucleotide phosphate (NADPH), via the flavins flavin adenine dinucleotide and flavin mononucleotide in the carboxy-terminal reductase domain, to the heme in the amino-terminal oxygenase domain. Here, the substrate L-arginine is oxidized to L-citrulline and NO. Cardiovascular risk factors such as diabetes mellitus, hypertension, hypercholesterolaemia or cigarette smoking reduce bioactive NO. These risk factors lead to an enhanced production of reactive oxygen species (ROS) in the vessel wall. NADPH oxidases represent major sources of this ROS and have been found upregulated in the presence of cardiovascular risk factors. NADPH-oxidase-derived superoxide avidly reacts with eNOS-derived NO to form peroxynitrite (ONOO-). The essential NOS cofactor (6R-)5,6,7,8-tetrahydrobiopterin (BH4) is highly sensitive to oxidation by this ONOO-. In BH4 deficiency, oxygen reduction uncouples from NO synthesis, thereby converting NOS to a superoxide-producing enzyme. Among conventional drugs, compounds interfering with the renin-angiotensin-aldosterone system and statins can reduce vascular oxidative stress and increase bioactive NO. In recent years, we have identified a number of small molecules that have the potential to prevent eNOS uncoupling and, at the same time, enhance eNOS expression. These include the protein kinase C inhibitor midostaurin, the pentacyclic triterpenoids ursolic acid and betulinic acid, the eNOS enhancing compounds AVE9488 and AVE3085, and the polyphenolic phytoalexin trans-resveratrol. Such compounds enhance NO production from eNOS also under pathophysiological conditions and may thus have therapeutic potential. PMID:21198553

  11. Vascular endothelial dysfunction in Duchenne muscular dystrophy is restored by bradykinin through upregulation of eNOS and nNOS

    PubMed Central

    Dabiré, Hubert; Barthélémy, Inès; Blanchard-Gutton, Nicolas; Sambin, Lucien; Sampedrano, Carolina Carlos; Gouni, Vassiliki; Unterfinger, Yves; Aguilar, Pablo; Thibaud, Jean-Laurent; Ghaleh, Bijan; Bizé, Alain; Pouchelon, Jean-Louis; Blot, Stéphane; Berdeaux, Alain; Hittinger, Luc; Chetboul, Valérie; Su, Jin Bo

    2012-01-01

    Little is known about the vascular function and expression of endothelial and neuronal nitric oxide synthases (eNOS and nNOS) in Duchenne muscular dystrophy (DMD). Bradykinin is involved in the regulation of eNOS expression induced by angiotensin-converting enzyme inhibitors. We characterized the vascular function and eNOS and nNOS expression in a canine model of DMD and evaluated the effects of chronic bradykinin treatment. Vascular function was examined in conscious golden retriever muscular dystrophy (GRMD) dogs with left ventricular dysfunction (measured by echocardiography) and in isolated coronary arteries. eNOS and nNOS proteins in carotid arteries were measured by western blot and cyclic guanosine monophosphate (cGMP) content was analyzed by radioimmunoassay. Compared with controls, GRMD dogs had an impaired vasodilator response to acetylcholine. In isolated coronary artery, acetylcholine-elicited relaxation was nearly absent in placebo-treated GRMD dogs. This was explained by reduced nNOS and eNOS proteins and cGMP content in arterial tissues. Chronic bradykinin infusion (1 μg/min, 4 weeks) restored in vivo and in vitro vascular response to acetylcholine to the level of control dogs. This effect was NO-mediated through upregulation of eNOS and nNOS expression. In conclusion, this study is the first to demonstrate that DMD is associated with NO-mediated vascular endothelial dysfunction linked to an altered expression of eNOS and nNOS, which can be overcome by bradykinin. PMID:22193759

  12. Functional significance of differential eNOS translocation

    PubMed Central

    Sánchez, Fabiola A.; Savalia, Nirav B.; Durán, Ricardo G.; Lal, Brajesh K.; Boric, Mauricio P.; Durán, Walter N.

    2006-01-01

    Nitric oxide (NO) regulates flow and permeability. ACh and platelet-activating factor (PAF) lead to endothelial NO synthase (eNOS) phosphorylation and NO release. While ACh causes only vasodilation, PAF induces vasoconstriction and hyperpermeability. The key differential signaling mechanisms for discriminating between vasodilation and hyperpermeability are unknown. We tested the hypothesis that differential translocation may serve as a regulatory mechanism of eNOS to determine specific vascular responses. We used ECV-304 cells permanently transfected with eNOS-green fluorescent protein (ECVeNOS-GFP) and demonstrated that the agonists activate eNOS and reproduce their characteristic endothelial permeability effects in these cells. We evaluated eNOS localization by lipid raft analysis and immunofluorescence microscopy. After PAF and ACh, eNOS moves away from caveolae. eNOS distributes both in the plasma membrane and Golgi in control cells. ACh (10−5 M, 10−4 M) translocated eNOS preferentially to the trans-Golgi network (TGN) and PAF (10−7 M) preferentially to the cytosol. We suggest that PAF-induced eNOS translocation preferentially to cytosol reflects a differential signaling mechanism related to changes in permeability, whereas ACh-induced eNOS translocation to the TGN is related to vasodilation. PMID:16679407

  13. Instructional Strategy for Promoting Understanding of Nature of Science

    ERIC Educational Resources Information Center

    Chimphali, Kamonrat; Nuangchalerm, Prasart; Ladachart, Luecha

    2013-01-01

    The Nature of science (NOS) has been thought of as an important component of "Science literacy" that the goal of standards-based science education. The aim of this paper try to present NOS for science education. Hereby, we may compile and notice where we promote students' understanding NOS. We find the highlight by using…

  14. Design of Chemistry Teacher Education Course on Nature of Science

    ERIC Educational Resources Information Center

    Vesterinen, Veli-Matti; Aksela, Maija

    2013-01-01

    To enhance students' understanding of nature of science (NOS), teachers need adequate pedagogical content knowledge related to NOS. The educational design research study presented here describes the design and development of a pre-service chemistry teacher education course on NOS instruction. The study documents two iterative cycles of…

  15. Unexpected Heterodivalent Recruitment of NOS1AP to nNOS Reveals Multiple Sites for Pharmacological Intervention in Neuronal Disease Models.

    PubMed

    Li, Li-Li; Melero-Fernandez de Mera, Raquel M; Chen, Jia; Ba, Wei; Kasri, Nael Nadif; Zhang, Mingjie; Courtney, Michael J

    2015-05-13

    The protein NOS1AP/CAPON mediates signaling from a protein complex of NMDA receptor, PSD95 and nNOS. The only stroke trial for neuroprotectants that showed benefit to patients targeted this ternary complex. NOS1AP/nNOS interaction regulates small GTPases, iron transport, p38MAPK-linked excitotoxicity, and anxiety. Moreover, the nos1ap gene is linked to disorders from schizophrenia, post-traumatic stress disorder, and autism to cardiovascular disorders and breast cancer. Understanding protein interactions required for NOS1AP function, therefore, has broad implications for numerous diseases. Here we show that the interaction of NOS1AP with nNOS differs radically from the classical PDZ docking assumed to be responsible. The NOS1AP PDZ motif does not bind nNOS as measured by multiple methods. In contrast, full-length NOS1AP forms an unusually stable interaction with nNOS. We mapped the discrepancy between full-length and C-terminal PDZ motif to a novel internal region we call the ExF motif. The C-terminal PDZ motif, although neither sufficient nor necessary for binding, nevertheless promotes the stability of the complex. It therefore potentially affects signal transduction and suggests that functional interaction of nNOS with NOS1AP might be targetable at two distinct sites. We demonstrate that excitotoxic pathways can be regulated, in cortical neuron and organotypic hippocampal slice cultures from rat, either by the previously described PDZ ligand TAT-GESV or by the ExF motif-bearing region of NOS1AP, even when lacking the critical PDZ residues as long as the ExF motif is intact and not mutated. This previously unrecognized heterodivalent interaction of nNOS with NOS1AP may therefore provide distinct opportunities for pharmacological intervention in NOS1AP-dependent signaling and excitotoxicity. Copyright © 2015 the authors 0270-6474/15/357349-16$15.00/0.

  16. Using History of Science to Teach Nature of Science to Elementary Students

    ERIC Educational Resources Information Center

    Fouad, Khadija E.; Masters, Heidi; Akerson, Valarie L.

    2015-01-01

    Science lessons using inquiry only or history of science with inquiry were used for explicit reflective nature of science (NOS) instruction for second-, third-, and fourth-grade students randomly assigned to receive one of the treatments. Students in both groups improved in their understanding of creative NOS, tentative NOS, empirical NOS, and…

  17. Science Teachers' Conceptions of Nature of Science: The Case of Bangladesh

    ERIC Educational Resources Information Center

    Sarkar, Md. Mahbub Alam; Gomes, Jui Judith

    2010-01-01

    This study explored Bangladeshi science teachers' conceptions of nature of science (NOS) with a particular focus on the nature of (a) scientific knowledge, (b) scientific inquiry and (c) scientific enterprise. The tentative, inferential, subjective and creative NOS, in addition to the myths of the scientific method and experimentation, the nature…

  18. Spanish Students' Conceptions about NOS and STS Issues: A Diagnostic Study

    ERIC Educational Resources Information Center

    Vázquez-Alonso, Ángel; García-Carmona, Antonio; Manassero-Mas, María Antonia; Bennàssar-Roig, Antoni

    2014-01-01

    Spanish students' beliefs on themes of Science-Technology-Society (STS) and nature of science (NOS) are assessed. The sample consisted of 1050 science and non-science students who had concluded their pre-university education (18-19 years old). Each participant anonymously answered 30 items drawn from the Questionnaire of Opinions on Science,…

  19. Working with the nature of science in physics class: turning ‘ordinary’ classroom situations into nature of science learning situations

    NASA Astrophysics Data System (ADS)

    Hansson, Lena; Leden, Lotta

    2016-09-01

    In the science education research field there is a large body of literature on the ‘nature of science’ (NOS). NOS captures issues about what characterizes the research process as well as the scientific knowledge. Here we, in line with a broad body of literature, use a wide definition of NOS including also e.g. socio-cultural aspects. It is argued that NOS issues, for a number of reasons, should be included in the teaching of science/physics. Research shows that NOS should be taught explicitly. There are plenty of suggestions on specific and separate NOS activities, but the necessity of discussing NOS issues in connection to specific science/physics content and to laboratory work, is also highlighted. In this article we draw on this body of literature on NOS and science teaching, and discuss how classroom situations in secondary physics classes could be turned into NOS-learning situations. The discussed situations have been suggested by secondary teachers, during in-service teacher training, as situations from every-day physics teaching, from which NOS could be highlighted.

  20. A Socioscientific Curriculum Facilitating the Development of Distal and Proximal NOS Conceptualizations

    ERIC Educational Resources Information Center

    Schalk, Kelly A.

    2012-01-01

    This study reports the effects of an innovative introductory microbiology course for undergraduates that used a socioscientific issues (SSI)-based curriculum. The study illustrates how an SSI-based intervention provides learners with pragmatic opportunities for cultivating their scientific literacy subsuming the nature of science (NOS). Empirical…

  1. Science Olympiad students' nature of science understandings

    NASA Astrophysics Data System (ADS)

    Philpot, Cindy J.

    2007-12-01

    Recent reform efforts in science education focus on scientific literacy for all citizens. In order to be scientifically literate, an individual must have informed understandings of nature of science (NOS), scientific inquiry, and science content matter. This study specifically focused on Science Olympiad students' understanding of NOS as one piece of scientific literacy. Research consistently shows that science students do not have informed understandings of NOS (Abd-El-Khalick, 2002; Bell, Blair, Crawford, and Lederman, 2002; Kilcrease and Lucy, 2002; Schwartz, Lederman, and Thompson, 2001). However, McGhee-Brown, Martin, Monsaas and Stombler (2003) found that Science Olympiad students had in-depth understandings of science concepts, principles, processes, and techniques. Science Olympiad teams compete nationally and are found in rural, urban, and suburban schools. In an effort to learn from students who are generally considered high achieving students and who enjoy science, as opposed to the typical science student, the purpose of this study was to investigate Science Olympiad students' understandings of NOS and the experiences that formed their understandings. An interpretive, qualitative, case study method was used to address the research questions. The participants were purposefully and conveniently selected from the Science Olympiad team at a suburban high school. Data collection consisted of the Views of Nature of Science -- High School Questionnaire (VNOS-HS) (Schwartz, Lederman, & Thompson, 2001), semi-structured individual interviews, and a focus group. The main findings of this study were similar to much of the previous research in that the participants had informed understandings of the tentative nature of science and the role of inferences in science, but they did not have informed understandings of the role of human imagination and creativity, the empirical nature of science, or theories and laws. High level science classes and participation in

  2. Teaching Nature of Science to K-2 Students: What understandings can they attain?

    NASA Astrophysics Data System (ADS)

    Akerson, Valarie; Donnelly, Lisa A.

    2010-01-01

    This study explored the influence of a Saturday Science program that used explicit reflective instruction through contextualized and decontextualized guided and authentic inquiry on K-2 students' views of nature of science (NOS). The six-week program ran for 2.5 hours weekly and emphasized NOS in a variety of science content areas, culminating in an authentic inquiry designed and carried out by the K-2 students. The Views of Nature of Science Form D was used to interview K-2 students pre- and post-instruction. Copies of student work were retained for content analysis. Videotapes made of each week's science instruction were reviewed to ensure that explicit reflective NOS instruction took place. Explicit NOS teaching strategies included (1) introducing NOS through decontextualized activities, (2) embedding NOS into science content through contextualized activities, (3) using children's literature, (4) debriefings and embedded NOS assessments, and (5) guided and student-designed inquiries. Results indicate that K-2 students improved their NOS views over the course of the program, suggesting that they are developmentally ready for these concepts. Students developed adequate views of the distinction between observation and inference, the creative NOS, the tentative NOS, the empirical NOS, and to a lesser degree, the subjective NOS.

  3. Nature of Science and Science Content Learning. The Relation Between Students' Nature of Science Understanding and Their Learning About the Concept of Energy

    NASA Astrophysics Data System (ADS)

    Michel, Hanno; Neumann, Irene

    2016-12-01

    Besides viewing knowledge about the nature of science (NOS) as important for its own value with respect to scientific literacy, an adequate understanding of NOS is expected to improve science content learning by fostering the ability to interrelate scientific concepts and, thus, coherently acquire scientific content knowledge. However, there is a lack of systematic investigations, which clarify the relations between NOS and science content learning. In this paper, we present the results of a study, conducted to investigate how NOS understanding relates to students' acquisition of a proper understanding of the concept of energy. A total of 82 sixth and seventh grade students received an instructional unit on energy, with 41 of them receiving generic NOS instruction beforehand. This NOS instruction, however, did not result in students having higher scores on the NOS instrument. Thus, correlational analyses were performed to investigate how students' NOS understanding prior to the energy unit related to their learning about science content. Results show that a more adequate understanding of NOS might relate to students' perspective on the concept of energy and might support them in understanding the nature of energy as a theoretical concept. Students with higher NOS understanding, for example, seemed to be more capable of learning how to relate the different energy forms to each other and to justify why they can be subsumed under the term of energy. Further, we found that NOS understanding may also be related to students' approach toward energy degradation—a concept that can be difficult for students to master—while it does not seem to have a substantive impact on students' learning gain regarding energy forms, transformation, or conservation.

  4. Neuronal NOS localises to human airway cilia.

    PubMed

    Jackson, Claire L; Lucas, Jane S; Walker, Woolf T; Owen, Holly; Premadeva, Irnthu; Lackie, Peter M

    2015-01-30

    Airway NO synthase (NOS) isoenzymes are responsible for rapid and localised nitric oxide (NO) production and are expressed in airway epithelium. We sought to determine the localisation of neuronal NOS (nNOS) in airway epithelium due to the paucity of evidence. Sections of healthy human bronchial tissue in glycol methacrylate resin and human nasal polyps in paraffin wax were immunohistochemically labelled and reproducibly demonstrated nNOS immunoreactivity, particularly at the proximal portion of cilia; this immunoreactivity was blocked by a specific nNOS peptide fragment. Healthy human epithelial cells differentiated at an air-liquid interface (ALI) confirmed the presence of all three NOS isoenzymes by immunofluorescence labelling. Only nNOS immunoreactivity was specific to the ciliary axonemeand co-localised with the cilia marker β-tubulin in the proximal part of the ciliary axoneme. We report a novel localisation of nNOS at the proximal portion of cilia in airway epithelium and conclude that its independent and local regulation of NO levels is crucial for normal cilia function. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. An exploration of worldview and conceptions of nature of science among science teachers at a private Christian high school

    NASA Astrophysics Data System (ADS)

    Kits, Kara M.

    Both worldview and conceptions of nature of science (NOS) are important components in teaching and learning science. However, few empirical studies have examined the interplay between both of these components for teachers or students. Therefore, this study examines the possible relationship between worldview and conceptions of nature of science for secondary science teachers who currently teach at a Christian school. Qualitative methodologies developed a rich description of the worldview beliefs and conceptions of NOS for teachers in this study. Eight secondary science teachers employed at a private Christian school participated in the study. A Views of Nature of Science (VNOS) questionnaire and follow-up interviews elicited participants' conceptions of NOS. A semi-structured interview and Test of Preferred Explanations (TOPE) questionnaire elicited participants' worldview beliefs regarding nature and the natural world and causality. Participants communicated understandings of NOS that ranged from uninformed to informed in various aspects. In addition, while their worldview beliefs and conceptions of NOS reflected their faith beliefs, participants did not have a less informed view of NOS than other science teachers in previous studies. In fact, for several aspects of NOS, these participants articulated more informed conceptions of NOS than participants in previous studies. For these participants, faith did not appear to interfere with their ability to think scientifically in regards to their worldview beliefs regarding nature and causality. Rather, faith was incorporated into a scientifically compatible worldview regarding nature and causality that is not much different from other teachers. Other than the fact that these science teachers integrated their faith beliefs into some of their responses regarding worldview and NOS, these teachers did not appear to be much different from other science teachers. That is, there was no predictable pattern between worldview

  6. 76 FR 4516 - Revisions to Forms, Statements, and Reporting Requirements for Natural Gas Pipelines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-26

    ...; Order No. 710-B] Revisions to Forms, Statements, and Reporting Requirements for Natural Gas Pipelines... for natural gas companies, contained in FERC Form Nos. 2, 2-A, and 3-Q, to include functionalized fuel..., and reports for natural gas companies, contained in FERC Form Nos. 2, 2-A, and 3-Q, to include...

  7. Dilemmas in Examining Understanding of Nature of Science in Vietnam

    ERIC Educational Resources Information Center

    Thao-Do, Thi Phuong; Yuenyong, Chokchai

    2017-01-01

    Scholars proved nature of science (NOS) has made certain contributions to science teaching and learning. Nonetheless, what, how and how much NOS should be integrated in the science curriculum of each country cannot be a benchmark, due to the influence of culture and society. Before employing NOS in a new context, it should be carefully studied. In…

  8. Natural occupation numbers in two-electron quantum rings.

    PubMed

    Tognetti, Vincent; Loos, Pierre-François

    2016-02-07

    Natural orbitals (NOs) are central constituents for evaluating correlation energies through efficient approximations. Here, we report the closed-form expression of the NOs of two-electron quantum rings, which are prototypical finite-extension systems and new starting points for the development of exchange-correlation functionals in density functional theory. We also show that the natural occupation numbers for these two-electron paradigms are in general non-vanishing and follow the same power law decay as atomic and molecular two-electron systems.

  9. Natural occupation numbers in two-electron quantum rings

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Tognetti, Vincent, E-mail: vincent.tognetti@univ-rouen.fr; Loos, Pierre-François

    2016-02-07

    Natural orbitals (NOs) are central constituents for evaluating correlation energies through efficient approximations. Here, we report the closed-form expression of the NOs of two-electron quantum rings, which are prototypical finite-extension systems and new starting points for the development of exchange-correlation functionals in density functional theory. We also show that the natural occupation numbers for these two-electron paradigms are in general non-vanishing and follow the same power law decay as atomic and molecular two-electron systems.

  10. Natural antisense transcript-targeted regulation of inducible nitric oxide synthase mRNA levels.

    PubMed

    Yoshigai, Emi; Hara, Takafumi; Araki, Yoshiro; Tanaka, Yoshito; Oishi, Masaharu; Tokuhara, Katsuji; Kaibori, Masaki; Okumura, Tadayoshi; Kwon, A-Hon; Nishizawa, Mikio

    2013-04-01

    Natural antisense transcripts (asRNAs) are frequently transcribed from mammalian genes. Recently, we found that non-coding asRNAs are transcribed from the 3' untranslated region (3'UTR) of the rat and mouse genes encoding inducible nitric oxide synthase (iNOS), which catalyzes the production of the inflammatory mediator nitric oxide. The iNOS asRNA stabilizes iNOS mRNA by interacting with the mRNA 3'UTR. Furthermore, single-stranded 'sense' oligonucleotides corresponding to the iNOS mRNA sequence were found to reduce iNOS mRNA levels by interfering with mRNA-asRNA interactions in rat hepatocytes. This method was named natural antisense transcript-targeted regulation (NATRE) technology. In this study, we detected human iNOS asRNA expressed in hepatocarcinoma and colon carcinoma tissues. The human iNOS asRNA harbored a sequence complementary to an evolutionarily conserved region of the iNOS mRNA 3'UTR. When introduced into hepatocytes, iNOS sense oligonucleotides that were modified by substitution with partial phosphorothioate bonds and locked nucleic acids or 2'-O-methyl nucleic acids greatly reduced levels of iNOS mRNA and iNOS protein. Moreover, sense oligonucleotides and short interfering RNAs decreased iNOS mRNA to comparable levels. These results suggest that NATRE technology using iNOS sense oligonucleotides could potentially be used to treat human inflammatory diseases and cancers by reducing iNOS mRNA levels. Copyright © 2013 Elsevier Inc. All rights reserved.

  11. An investigation of Zimbabwe high school chemistry students' laboratory work-based images of the nature of science

    NASA Astrophysics Data System (ADS)

    Vhurumuku, Elaosi; Holtman, Lorna; Mikalsen, Oyvind; Kolsto, Stein D.

    2006-02-01

    This study investigates the proximal and distal images of the nature of science (NOS) that A-level students develop from their participation in chemistry laboratory work. We also explored the nature of the interactions among the students' proximal and distal images of the NOS and students' participation in laboratory work. Students' views of the NOS and the nature of their chemistry laboratory work were elicited through students' responses to an open-ended questionnaire and semistructured interviews. The results suggest that students build some understandings of the NOS from their participation in laboratory work. Students' proximal NOS understandings appear to build into and interact with their understandings of the nature and practice of professional science. This interaction appears to be mediated by the nature of instruction. It is posited that each student's conceptual ecological system is replete with interactions, which govern attenuation of proximal understandings into distal images. Methodologically, the study illustrates how students' laboratory work-based proximal and distal images of the NOS can be identified and extracted through analyzing and interpreting their responses to protocols. Implications for A-level Chemistry instruction and curriculum development are raised.

  12. Thai in-service teacher understanding of nature of science in biology teaching: Case of Mali

    NASA Astrophysics Data System (ADS)

    Aiemsum-ang, Napapan; Yuenyong, Chokchai

    2018-01-01

    This paper aimed to investigate the existing ideas of nature of science (NOS) teaching in Thailand biology classroom. The study reported the existing ideas of nature of science (NOS) teaching of one biology teacher Mrs. Mali who had been teaching for 6 years at in a school in Khon Kaen city. Methodology regarded interpretive paradigm. Tools of interpretation included 2 months of classroom observation, interviewing, and questionnaire of NOS. The findings revealed Mali held good understanding of the nature of science in the aspect of the use of evidence, the aspect of knowledge inquiry through different observation and deduction, the aspect of creativity and imagination influencing science knowledge inquiry, and the aspect of changeable scientific knowledge. Her biology teaching indicated that she used both the deficient nature of science approach and the implicit nature of science approach. The implicit nature of science approach was applied mostly in 7 periods and only 2 periods were arranged using the deficient nature of science approach. The paper has implication for professional development and pre-service program on NOS teaching in Thailand.

  13. The effect of high protein diet and exercise on irisin, eNOS, and iNOS expressions in kidney.

    PubMed

    Tastekin, Ebru; Palabiyik, Orkide; Ulucam, Enis; Uzgur, Selda; Karaca, Aziz; Vardar, Selma Arzu; Yilmaz, Ali; Aydogdu, Nurettin

    2016-08-01

    Long-term effects of high protein diets (HPDs) on kidneys are still not sufficiently studied. Irisin which increases oxygen consumption and thermogenesis in white fat cells was shown in skeletal muscles and many tissues. Nitric oxide synthases (NOS) are a family of enzymes catalyzing the production of nitric oxide (NO) from L-arginine. We aimed to investigate the effects of HPD, irisin and NO expression in kidney and relation of them with exercise and among themselves. Animals were grouped as control, exercise, HPD and exercise combined with HPD (exercise-HPD). Rats were kept on a HPD for 5 weeks and an exercise program was given them as 5 exercise and 2 rest days per week exercising on a treadmill with increasing speed and angle. In our study, while HPD group had similar total antioxidant capacity (TAC) levels with control group, exercise and exercise-HPD groups had lower levels (p < 0.05). Kidneys of exercising rats had no change in irisin or eNOS expression but their iNOS expression had increased (p < 0.001). HPD-E group has not been observed to cause kidney damage and not have a significant effect on rat kidney irisin, eNOS, or iNOS expression. Localization of irisin, eNOS, and iNOS staining in kidney is highly selective and quite clear in this study. Effects of exercise and HPD on kidney should be evaluated with different exercise protocols and contents of the diet. İrisin, eNOS, and iNOS staining localizations should be supported with various research studies.

  14. An analysis of South African Grade 9 natural sciences textbooks for their representation of nature of science

    NASA Astrophysics Data System (ADS)

    Dewnarain Ramnarain, Umesh; Chanetsa, Tarisai

    2016-04-01

    This article reports on an analysis and comparison of three South African Grade 9 (13-14 years) Natural Sciences textbooks for the representation of nature of science (NOS). The analysis was framed by an analytical tool developed and validated by Abd-El-Khalick and a team of researchers in a large-scale study on the high school textbooks in the USA. The three textbooks were scored on targeted NOS aspects on a scale of -3 to +3 that reflected the explicitness with which these aspects were addressed. The analysis revealed that the textbooks poorly depict NOS, and in particular, there was scant attention given to the social dimension of science, science versus pseudoscience and the 'myth of the scientific method'. The findings of this study are incommensurate with the strong emphasis in a reformed school science curriculum that underlies the need for learners to understand the scientific enterprise, and how scientific knowledge develops. In view of this, the findings of this research reinforce the need for a review on the mandate given to textbook publishers and writers so that a stronger focus be placed on the development of materials that better represent the tenets of NOS.

  15. Enhancing Students' NOS Views and Science Knowledge Using Facebook-Based Scientific News

    ERIC Educational Resources Information Center

    Huang, Hsi-Yu; Wu, Hui-Ling; She, Hsiao-Ching; Lin, Yu-Ren

    2014-01-01

    This study investigated how the different discussion approaches in Facebook influenced students' scientific knowledge acquisition and the nature of science (NOS) views. Two eighth- and two ninth-grade classes in a Taiwanese junior high school participated in the study. In two of the classes students engaged in synchronous discussion, and in the…

  16. The Nature of Science Instrument-Elementary (NOSI-E): Using Rasch principles to develop a theoretically grounded scale to measure elementary student understanding of the nature of science

    NASA Astrophysics Data System (ADS)

    Peoples, Shelagh

    The purpose of this study was to determine which of three competing models will provide, reliable, interpretable, and responsive measures of elementary students' understanding of the nature of science (NOS). The Nature of Science Instrument-Elementary (NOSI-E), a 28-item Rasch-based instrument, was used to assess students' NOS understanding. The NOS construct was conceptualized using five construct dimensions (Empirical, Inventive, Theory-laden, Certainty and Socially & Culturally Embedded). The competing models represent three internal models for the NOS construct. One postulate is that the NOS construct is unidimensional where one latent construct explains the relationship between the 28 items of the NOSI-E. Alternatively, the NOS construct is composed of five independent unidimensional constructs (the consecutive approach). Lastly, the NOS construct is multidimensional and composed of five inter-related but separate dimensions. A validity argument was developed that hypothesized that the internal structure of the NOS construct is best represented by the multidimensional Rasch model. Four sets of analyses were performed in which the three representations were compared. These analyses addressed five validity aspects (content, substantive, generalizability, structural and external) of construct validity. The vast body of evidence supported the claim that the NOS construct is composed of five separate but inter-related dimensions that is best represented by the multidimensional Rasch model. The results of the multidimensional analyses indicated that the items of the five subscales were of excellent technical quality, exhibited no differential item functioning (based on gender), had an item hierarchy that conformed to theoretical expectations; and together formed subscales of reasonable reliability (> 0.7 on each subscale) that were responsive to change in the construct. Theory-laden scores from the multidimensional model predicted students' science achievement with

  17. Examining Preservice Science Teacher Understanding of Nature of Science: Discriminating Variables on the Aspects of Nature of Science

    NASA Astrophysics Data System (ADS)

    Jones, William I.

    This study examined the understanding of nature of science among participants in their final year of a 4-year undergraduate teacher education program at a Midwest liberal arts university. The Logic Model Process was used as an integrative framework to focus the collection, organization, analysis, and interpretation of the data for the purpose of (1) describing participant understanding of NOS and (2) to identify participant characteristics and teacher education program features related to those understandings. The Views of Nature of Science Questionnaire form C (VNOS-C) was used to survey participant understanding of 7 target aspects of Nature of Science (NOS). A rubric was developed from a review of the literature to categorize and score participant understanding of the target aspects of NOS. Participants' high school and college transcripts, planning guides for their respective teacher education program majors, and science content and science teaching methods course syllabi were examined to identify and categorize participant characteristics and teacher education program features. The R software (R Project for Statistical Computing, 2010) was used to conduct an exploratory analysis to determine correlations of the antecedent and transaction predictor variables with participants' scores on the 7 target aspects of NOS. Fourteen participant characteristics and teacher education program features were moderately and significantly ( p < .01) correlated with participant scores on the target aspects of NOS. The 6 antecedent predictor variables were entered into multiple regression analyses to determine the best-fit model of antecedent predictor variables for each target NOS aspect. The transaction predictor variables were entered into separate multiple regression analyses to determine the best-fit model of transaction predictor variables for each target NOS aspect. Variables from the best-fit antecedent and best-fit transaction models for each target aspect of NOS were

  18. Changing Epistemological Beliefs with Nature of Science Implementations

    ERIC Educational Resources Information Center

    Johnson, Keith; Willoughby, Shannon

    2018-01-01

    This article discusses our investigation regarding nature of science (NOS) implementations and epistemological beliefs within an undergraduate introductory astronomy course. The five year study consists of two years of baseline data in which no explicit use of NOS material was implemented, then three years of subsequent data in which specific NOS…

  19. iNOS-dependent sweating and eNOS-dependent cutaneous vasodilation are evident in younger adults, but are diminished in older adults exercising in the heat

    PubMed Central

    Fujii, Naoto; Meade, Robert D.; Alexander, Lacy M.; Akbari, Pegah; Foudil-bey, Imane; Louie, Jeffrey C.; Boulay, Pierre

    2015-01-01

    Nitric oxide synthase (NOS) contributes to sweating and cutaneous vasodilation during exercise in younger adults. We hypothesized that endothelial NOS (eNOS) and neuronal NOS (nNOS) mediate NOS-dependent sweating, whereas eNOS induces NOS-dependent cutaneous vasodilation in younger adults exercising in the heat. Further, aging may upregulate inducible NOS (iNOS), which may attenuate sweating and cutaneous vasodilator responses. We hypothesized that iNOS inhibition would augment sweating and cutaneous vasodilation in exercising older adults. Physically active younger (n = 12, 23 ± 4 yr) and older (n = 12, 60 ± 6 yr) adults performed two 30-min bouts of cycling at a fixed rate of metabolic heat production (400 W) in the heat (35°C). Sweat rate and cutaneous vascular conductance (CVC) were evaluated at four intradermal microdialysis sites with: 1) lactated Ringer (control), 2) nNOS inhibitor (nNOS-I, NPLA), 3) iNOS inhibitor (iNOS-I, 1400W), or 4) eNOS inhibitor (eNOS-I, LNAA). In younger adults during both exercise bouts, all inhibitors decreased sweating relative to control, albeit a lower sweat rate was observed at iNOS-I compared with eNOS-I and nNOS-I sites (all P < 0.05). CVC at the eNOS-I site was lower than control in younger adults throughout the intermittent exercise protocol (all P < 0.05). In older adults, there were no differences between control and iNOS-I sites for sweating and CVC during both exercise bouts (all P > 0.05). We show that iNOS and eNOS are the main contributors to NOS-dependent sweating and cutaneous vasodilation, respectively, in physically active younger adults exercising in the heat, and that iNOS inhibition does not alter sweating or cutaneous vasodilation in exercising physically active older adults. PMID:26586908

  20. iNOS-dependent sweating and eNOS-dependent cutaneous vasodilation are evident in younger adults, but are diminished in older adults exercising in the heat.

    PubMed

    Fujii, Naoto; Meade, Robert D; Alexander, Lacy M; Akbari, Pegah; Foudil-Bey, Imane; Louie, Jeffrey C; Boulay, Pierre; Kenny, Glen P

    2016-02-01

    Nitric oxide synthase (NOS) contributes to sweating and cutaneous vasodilation during exercise in younger adults. We hypothesized that endothelial NOS (eNOS) and neuronal NOS (nNOS) mediate NOS-dependent sweating, whereas eNOS induces NOS-dependent cutaneous vasodilation in younger adults exercising in the heat. Further, aging may upregulate inducible NOS (iNOS), which may attenuate sweating and cutaneous vasodilator responses. We hypothesized that iNOS inhibition would augment sweating and cutaneous vasodilation in exercising older adults. Physically active younger (n = 12, 23 ± 4 yr) and older (n = 12, 60 ± 6 yr) adults performed two 30-min bouts of cycling at a fixed rate of metabolic heat production (400 W) in the heat (35°C). Sweat rate and cutaneous vascular conductance (CVC) were evaluated at four intradermal microdialysis sites with: 1) lactated Ringer (control), 2) nNOS inhibitor (nNOS-I, NPLA), 3) iNOS inhibitor (iNOS-I, 1400W), or 4) eNOS inhibitor (eNOS-I, LNAA). In younger adults during both exercise bouts, all inhibitors decreased sweating relative to control, albeit a lower sweat rate was observed at iNOS-I compared with eNOS-I and nNOS-I sites (all P < 0.05). CVC at the eNOS-I site was lower than control in younger adults throughout the intermittent exercise protocol (all P < 0.05). In older adults, there were no differences between control and iNOS-I sites for sweating and CVC during both exercise bouts (all P > 0.05). We show that iNOS and eNOS are the main contributors to NOS-dependent sweating and cutaneous vasodilation, respectively, in physically active younger adults exercising in the heat, and that iNOS inhibition does not alter sweating or cutaneous vasodilation in exercising physically active older adults. Copyright © 2016 the American Physiological Society.

  1. Contextualizing Nature of Science Instruction in Socioscientific Issues

    ERIC Educational Resources Information Center

    Eastwood, Jennifer Lynne; Sadler, Troy D.; Zeidler, Dana L.; Lewis, Anna; Amiri, Leila; Applebaum, Scott

    2012-01-01

    The purpose of this study was to investigate the effects of two learning contexts for explicit-reflective nature of science (NOS) instruction, socioscientific issues (SSI) driven and content driven, on student NOS conceptions. Four classes of 11th and 12th grade anatomy and physiology students participated. Two classes experienced a curricular…

  2. Changes in the Perceptions of the Nature of Science and Religious Belief

    ERIC Educational Resources Information Center

    Aflalo, Ester

    2018-01-01

    Understanding the nature of science (NOS) is one of the challenging objectives in science education due, in part, to the complex relationship between religion and science. This study examines how NOS teaching affects the perception of the NOS amongst religious, as compared to secular, students. The participants included 205 religious and secular…

  3. Using History of Science to Teach Nature of Science to Elementary Students

    NASA Astrophysics Data System (ADS)

    Fouad, Khadija E.; Masters, Heidi; Akerson, Valarie L.

    2015-11-01

    Science lessons using inquiry only or history of science with inquiry were used for explicit reflective nature of science (NOS) instruction for second-, third-, and fourth-grade students randomly assigned to receive one of the treatments. Students in both groups improved in their understanding of creative NOS, tentative NOS, empirical NOS, and subjective NOS as measured using VNOS-D as pre- and post-test surveys. Social and cultural context of science was not accessible for the students. Students in second, third, and fourth grades were able to attain adequate views of empirical NOS, the role of observation and inference, creative and imaginative NOS, and subjective NOS. Students were not able to express adequate views of socially and culturally embedded NOS. Most gains in NOS eroded by the next school year, except for tentative NOS for both groups and creative NOS for the inquiry group.

  4. Opening the Black Box of NOS: Or Knowing How to Go on with Science Education, Wittgenstein, and STS in a Precarious World

    ERIC Educational Resources Information Center

    Alsop, Steve; Gardner, Sam

    2017-01-01

    In this response essay we offer some critical comments on the nature of science (NOS) and thereby hopefully extend Hodson and Wong's (2017, this issue) argument concerning "understanding scientific practice." Drawing on selected theorising in science and technology studies (STS), we argue that NOS needs to take much more seriously…

  5. Developing the Inner Scientist: Book Club Participation and The Nature of Science

    PubMed Central

    Griffard, Phyllis Baudoin; Mosleh, Tayseer; Kubba, Saad

    2013-01-01

    The leap from science student to scientist involves recognizing that science is a tentative, evolving body of knowledge that is socially constructed and culturally influenced; this is known as The Nature of Science (NOS). The aim of this study was to document NOS growth in first-year premedical students who participated in a science book club as a curricular option. The club read three acclaimed nonfiction works that connect biology to medicine via the history of scientific ideas. Students’ NOS status was assessed as informed, transitional, or naïve at the beginning and end of the academic year using the Views of Nature of Science Questionnaire–Form C (VNOS-C). Focus group interviews and document analysis of assignments and exams provided qualitative evidence. VNOS-C scores improved over the academic year regardless of book club participation. Students who participated in book club had marginally better NOS status at the end of the year but also at the beginning, suggesting that book club may have attracted rather than produced students with higher NOS status. It is notable that an improvement in NOS understanding could be detected at all, as there have been few reports of NOS growth in the literature in which NOS was not an explicit topic of instruction. PMID:23463231

  6. Developing the inner scientist: book club participation and the nature of science.

    PubMed

    Griffard, Phyllis Baudoin; Mosleh, Tayseer; Kubba, Saad

    2013-01-01

    The leap from science student to scientist involves recognizing that science is a tentative, evolving body of knowledge that is socially constructed and culturally influenced; this is known as The Nature of Science (NOS). The aim of this study was to document NOS growth in first-year premedical students who participated in a science book club as a curricular option. The club read three acclaimed nonfiction works that connect biology to medicine via the history of scientific ideas. Students' NOS status was assessed as informed, transitional, or naïve at the beginning and end of the academic year using the Views of Nature of Science Questionnaire-Form C (VNOS-C). Focus group interviews and document analysis of assignments and exams provided qualitative evidence. VNOS-C scores improved over the academic year regardless of book club participation. Students who participated in book club had marginally better NOS status at the end of the year but also at the beginning, suggesting that book club may have attracted rather than produced students with higher NOS status. It is notable that an improvement in NOS understanding could be detected at all, as there have been few reports of NOS growth in the literature in which NOS was not an explicit topic of instruction.

  7. Introducing Taiwanese undergraduate students to the nature of science through Nobel Prize stories

    NASA Astrophysics Data System (ADS)

    Eshach, Haim; Hwang, Fu-Kwun; Wu, Hsin-Kai; Hsu, Ying-Shao

    2013-06-01

    Although there is a broad agreement among scientists and science educators that students should not only learn science, but also acquire some sense of its nature, it has been reported that undergraduate students possess an inadequate grasp of the nature of science (NOS). The study presented here examined the potential and effectiveness of Nobel Prize stories as a vehicle for teaching NOS. For this purpose, a 36-hour course, “Albert Einstein’s Nobel Prize and the Nature of Science,” was developed and conducted in Taiwan Normal University. Ten undergraduate physics students participated in the course. Analysis of the Views of Nature of Science questionnaires completed by the students before and after the course, as well as the students’ own presentations of Nobel Prize stories (with an emphasis on how NOS characteristics are reflected in the story), showed that the students who participated in the course enriched their views concerning all aspects of NOS. The paper concludes with some suggestions for applying the novel idea of using Nobel Prize stories in physics classrooms.

  8. Challenges and strategies for effectively teaching the nature of science: A qualitative case study

    NASA Astrophysics Data System (ADS)

    Koehler, Catherine M.

    This year long, qualitative, case study examines two, experienced, high school, biology teachers as they facilitated nature of science (NOS) understandings in their classrooms. This study explored three research questions: (1) In what ways do experienced teachers' conceptions of NOS evolve over one full year as a result of participating in a course that explicitly address NOS teaching and learning? (2) In what ways do experienced teachers' pedagogical practices evolve over one full year as a result of participating in a course that explicitly address NOS teaching and learning?, and (3) What are the challenges facing experienced teachers in their attempts to implement NOS understandings in their science, high school classrooms? This study was conducted in two parts. In Part I (fall 2004 semester), the participants were enrolled in a graduate course titled, Teaching the Nature of Science , where they were introduced to: (1) NOS, (2) a strategy, the Model for Teaching NOS (MTNOS), which helped them facilitate teaching NOS understandings through inquiry-based activities, and (3) participated in "real" science activities that reinforced their conceptions of NOS. In Part II (spring 2005 semester), classroom observations were made to uncover how these teachers implemented inquiry-based activities emphasizing NOS understanding in their classrooms. Their conceptions of NOS were measured using the Views of the Nature of Science questionnaire. Results demonstrated that each teacher's conceptions of NOS shifted slightly during course the study, but, for one, this was not a permanent shift. Over the year, one teacher's pedagogical practices changed to include inquiry-based lessons using MTNOS; the other, although very amenable to using prepared inquiry-based lessons, did not change her pedagogical practices. Both reported similar challenges while facilitating NOS understanding. The most significant challenges included: (1) time management; (2) the perception that NOS was a

  9. Learning about the Nature of Science Using Algae

    ERIC Educational Resources Information Center

    Edelmann, Hans G.; Martius, Thilo; Hahn, Achim; Schlüter, Kirsten; Nessler, Stefan H.

    2016-01-01

    Enquiry learning and teaching about the nature of science (NoS) is a key element of science education. We have designed an experimental setting for students aged 12-14 years to exercise enquiry-learning skills and to introduce students to the NoS aspects of creativity and imagination. It also illustrates the impact of carbon dioxide on the growth…

  10. Describing Teachers' Conceptual Ecologies for the Nature of Science

    ERIC Educational Resources Information Center

    Southerland, Sherry A.; Johnston, Adam; Sowell, Scott

    2006-01-01

    This research focused on the interactionist conceptual ecologies of inservice teachers and how these ecologies influenced these teachers' conceptual frameworks for the nature of science (NOS). The participants in the study were five teachers enrolled in a graduate course focused on NOS. Data included participants' responses to open-ended and…

  11. Nature of Science and Science Content Learning: The Relation between Students' Nature of Science Understanding and Their Learning about the Concept of Energy

    ERIC Educational Resources Information Center

    Michel, Hanno; Neumann, Irene

    2016-01-01

    Besides viewing knowledge about the nature of science (NOS) as important for its own value with respect to scientific literacy, an adequate understanding of NOS is expected to improve science content learning by fostering the ability to interrelate scientific concepts and, thus, coherently acquire scientific content knowledge. However, there is a…

  12. A 5E Nature of Science Introduction: Preparing Students to Learn about Evolution

    ERIC Educational Resources Information Center

    Bilica, Kimberly

    2012-01-01

    Teachers often struggle with controversy when teaching biological evolution in American schools. Research indicates that curriculum with a nature of science (NOS) focus quells controversy (McComas 2004; Scharmann 2005; Staver 2003). This article presents a 5E NOS series that is a first step in a NOS curriculum that situates student understanding…

  13. Views from the Chalkface: Values of Teaching Nature of Science in Hong Kong

    ERIC Educational Resources Information Center

    Wan, Zhi Hong; Wong, Siu Ling

    2016-01-01

    Although the goal of developing school students' understanding of nature of science (NOS) has long been advocated, there is still a lack of research that focuses on probing how science teachers, a kind of major stakeholder in NOS instruction, perceive the values of teaching NOS. Through semi-structured interviews, this study investigated the views…

  14. Changes in Students' Views about Nature of Scientific Inquiry at a Science Camp

    ERIC Educational Resources Information Center

    Leblebicioglu, G.; Metin, D.; Capkinoglu, E.; Cetin, P. S.; Eroglu Dogan, E.; Schwartz, R.

    2017-01-01

    Although nature of science (NOS) and nature of scientific inquiry (NOSI) are related to each other, they are differentiated as NOS is being more related to the product of scientific inquiry (SI) which is scientific knowledge whereas NOSI is more related to the process of SI (Schwartz et al. 2008). Lederman et al. ("Journal of Research in…

  15. What Scientists Say: Scientists' Views of Nature of Science and Relation to Science Context

    ERIC Educational Resources Information Center

    Schwartz, Renee; Lederman, Norman

    2008-01-01

    The purpose of this study is to examine practicing scientists' views of nature of science (NOS) and explore possible relationships between these views and science context. Science educators emphasize teaching NOS through inquiry-based learning experiences throughout science disciplines. Yet aspects of NOS that are agreed upon as relevant to…

  16. How Contextualized Learning Settings Enhance Meaningful Nature of Science Understanding

    ERIC Educational Resources Information Center

    Bilican, K.; Cakiroglu, J.; Oztekin, C.

    2015-01-01

    Exploring different contexts to facilitate in-depth nature of science (NOS) views were seen as critical for better professional development of pre-service science teachers, which ultimately would assure better students' NOS understanding and achieve an ultimate goal of current science education reforms. This study aimed to reduce the lack of…

  17. Different Conceptions of the Nature of Science among Preservice Elementary Teachers of Two Countries

    ERIC Educational Resources Information Center

    Park, Do-Yong; Lee, Yong Bok

    2009-01-01

    This study examined the differences of the nature of science (NOS) conceptions portrayed by preservice teachers in Korea (N = 42) and the United States (N = 50). We conducted a survey of preservice elementary science teachers' NOS conceptions followed by interviews in both countries to further investigate their viewpoints. The NOS domains of this…

  18. Eliciting the Views of Prospective Elementary and Preschool Teachers about the Nature of Science

    ERIC Educational Resources Information Center

    Karaman, Ayhan

    2018-01-01

    Recent science education standards emphasize the importance of the instruction of nature of science (NOS) concepts at all levels of schooling from pre-K to K-12. Delivering a proper NOS education to students is excessively dependent on their teachers with an adequate understanding of NOS concepts. The present study investigated the science…

  19. Relationship between soil type and N₂O reductase genotype (nosZ) of indigenous soybean bradyrhizobia: nosZ-minus populations are dominant in Andosols.

    PubMed

    Shiina, Yoko; Itakura, Manabu; Choi, Hyunseok; Saeki, Yuichi; Hayatsu, Masahito; Minamisawa, Kiwamu

    2014-01-01

    Bradyrhizobium japonicum strains that have the nosZ gene, which encodes N2O reductase, are able to mitigate N2O emissions from soils (15). To examine the distribution of nosZ genotypes among Japanese indigenous soybean bradyrhizobia, we isolated bradyrhizobia from the root nodules of soybean plants inoculated with 32 different soils and analyzed their nosZ and nodC genotypes. The 1556 resultant isolates were classified into the nosZ+/nodC+ genotype (855 isolates) and nosZ-/nodC+ genotype (701 isolates). The 11 soil samples in which nosZ- isolates significantly dominated (P < 0.05; the χ(2) test) were all Andosols (a volcanic ash soil prevalent in agricultural fields in Japan), whereas the 17 soil samples in which nosZ+ isolates significantly dominated were mainly alluvial soils (non-volcanic ash soils). This result was supported by a principal component analysis of environmental factors: the dominance of the nosZ- genotype was positively correlated with total N, total C, and the phosphate absorption coefficient in the soils, which are soil properties typical of Andosols. Internal transcribed spacer sequencing of representative isolates showed that the nosZ+ and nosZ- isolates of B. japonicum fell mainly into the USDA110 (BJ1) and USDA6 (BJ2) groups, respectively. These results demonstrated that the group lacking nosZ was dominant in Andosols, which can be a target soil type for an N2O mitigation strategy in soybean fields. We herein discussed how the nosZ genotypes of soybean bradyrhizobia depended on soil types in terms of N2O respiration selection and genomic determinants for soil adaptation.

  20. Understandings of Nature of Science and Multiple Perspective Evaluation of Science News by Non-science Majors

    NASA Astrophysics Data System (ADS)

    Leung, Jessica Shuk Ching; Wong, Alice Siu Ling; Yung, Benny Hin Wai

    2015-10-01

    Understandings of nature of science (NOS) are a core component of scientific literacy, and a scientifically literate populace is expected to be able to critically evaluate science in the media. While evidence has remained inconclusive on whether better NOS understandings will lead to critical evaluation of science in the media, this study aimed at examining the correlation therein. Thirty-eight non-science majors, enrolled in a science course for non-specialists held in a local community college, evaluated three health news articles by rating the extent to which they agreed with the reported claims and providing as many justifications as possible. The majority of the participants were able to evaluate and justify their viewpoint from multiple perspectives. Students' evaluation was compared with their NOS conceptions, including the social and cultural embedded NOS, the tentative NOS, the peer review process and the community of practice. Results indicated that participants' understanding of the tentative NOS was significantly correlated with multiple perspective evaluation of science news reports of socioscientific nature (r = 0.434, p < 0.05). This moderate correlation suggested the association between understanding of the tentative NOS and multiple perspective evaluation of science in the media of socioscientific nature. However, the null result for other target NOS aspects in this study suggested a lack of evidence to assume that understanding the social dimensions of science would have significant influence on the evaluation of science in the media. Future research on identifying the reasons for why and why not NOS understandings are applied in the evaluation will move this field forward.

  1. Elementary teachers' perceptions about the effective features of explicit-reflective nature of science instruction

    NASA Astrophysics Data System (ADS)

    Adibelli-Sahin, Elif; Deniz, Hasan

    2017-04-01

    This qualitative study explored elementary teachers' perceptions about the effective features of explicit-reflective nature of science (NOS) instruction. Our participants were four elementary teachers from a public charter school located in the Southwestern U.S.A. The four elementary teachers participated in an academic year-long professional development about NOS which consisted of NOS training and NOS teaching phases. After each phase of the professional development, we specifically asked our participants which features of the explicit-reflective NOS instruction they found effective in improving their NOS conceptions by presenting pre- and post-profiles of their NOS conceptions. We identified nine features perceived by the participants as effective components of explicit-reflective NOS instruction: (1) specific focus on NOS content, (2) participation in hands-on NOS activities, (3) introductory NOS readings, (4) multiple types/forms of reflection, (5) multiple exposure to NOS content, (6) structural consistency in the presentation of NOS content, (7) the evaluation of secondary NOS data from elementary students, (8) the analysis of national and state science standards in terms of NOS content, and (9) NOS teaching experience.

  2. Preservice teachers' use of lesson study in teaching nature of science

    NASA Astrophysics Data System (ADS)

    McDowell, Amy Virginia

    The purpose of this study was to explore preservice teachers' lived experiences in a lesson study focused on teaching and learning nature of science (NOS). The body of knowledge about shifting pre- and in-service novice NOS understandings is substantial. The focus of science education research is now exploring ways to move these informed NOS understandings into classroom practice (Abd-El-Khalick & Lederman, 2000b). The research questions guiding the study were (a) how do preservice teachers' understandings of NOS shift as a result of the lesson study experience?, and (b) how does the reflective practice that occurs in lesson study influence preservice teachers' transition of NOS tenets into classroom practice? The participants in this study represented a sample of graduate preservice teachers, who were part of a middle and secondary science teaching alternative certification program in a southeastern university. In the first summer semester of this certification program, the participants were immersed in reform based science instruction; a section of which included NOS teachings (INTASC, 2002). In the following semester, participants were placed in a practicum setting; where the exploration of the preservice teachers' teaching of NOS was supported through the modified lesson study framework. Data sources included the Views on Nature of Science-Form B (VNOS-b), interviews, and lesson study portfolios. Analysis of NOS understandings was guided by instruments found in literature associated with the VNOS-b (Lederman et al., 2002) and reflection (Ward & McCotter, 2004). Results showed successful transfer of NOS into classroom practice using the modified lesson study framework, with less success in the deepening of participants' NOS understandings. Of particular significance was that results indicated a deepening of NOS pedagogical content knowledge for those participants functioning at higher levels of reflection. The study's results contributes to two knowledge bases

  3. Pre-Service Chemistry Teachers' Pedagogical Content Knowledge of the Nature of Science in the Particle Nature of Matter

    ERIC Educational Resources Information Center

    Bektas, Oktay; Ekiz, Betul; Tuysuz, Mustafa; Kutucu, Elif Selcan; Tarkin, Aysegul; Uzuntiryaki-Kondakci, Esen

    2013-01-01

    This study investigated pre-service chemistry teachers' pedagogical content knowledge of the nature of science (NOS) in the content of the particle nature of matter. Qualitative research design was utilized. Data were collected from seven pre-service chemistry teachers (PCTs) by using open-ended questions, interviews, observations, lesson plans,…

  4. The Impact of a Course on Nature of Science Pedagogical Views and Rationales. Comparing Preservice Teachers in Their First Versus Second Experience

    NASA Astrophysics Data System (ADS)

    Kruse, Jerrid W.; Easter, Jaclyn M.; Edgerly, Hallie S.; Seebach, Colin; Patel, Neal

    2017-08-01

    This study explored changes in preservice teachers' (PSTs) nature of science pedagogical (NOSP) views and nature of science (NOS) rationales using pre- and post-course written responses as well as interview data. Through systematic analysis, themes were generated and compared to the NOS literature. Comparisons between pre- and post-course data demonstrate improved and deepened NOS views, NOSP views that are more aligned with NOS literature, and a greater number of rationales for including NOS. All participants were enrolled in the "Inquiry and Natures of Science, Technology, and Engineering" (INSTE) course. However, six participants were enrolled in INSTE as their first course in which NOS and NOSP were addressed. The other six participants were enrolled in INSTE as their second course in which NOS and NOSP were addressed, with science methods as their first course in which NOS and NOSP were addressed. By comparing participants enrolled in INSTE as their first course to those enrolled in INSTE as their second course, we observed that NOS understanding seemed to develop in a first experience alongside some NOS rationales, but NOSP views lagged for participants in INSTE as their first course. Participants enrolled in INSTE as their second course developed more robust and literature-aligned NOSP views and more multifaceted NOS rationales. Therefore, this study bolsters arguments that teachers need to receive extended NOS and NOSP instruction.

  5. Contextualizing Nature of Science Instruction in Socioscientific Issues

    NASA Astrophysics Data System (ADS)

    Eastwood, Jennifer Lynne; Sadler, Troy D.; Zeidler, Dana L.; Lewis, Anna; Amiri, Leila; Applebaum, Scott

    2012-10-01

    The purpose of this study was to investigate the effects of two learning contexts for explicit-reflective nature of science (NOS) instruction, socioscientific issues (SSI) driven and content driven, on student NOS conceptions. Four classes of 11th and 12th grade anatomy and physiology students participated. Two classes experienced a curricular sequence organized around SSI (the SSI group), and two classes experienced a content-based sequence (the Content group). An open-ended NOS questionnaire was administered to both groups at the beginning and end of the school year and analyzed to generate student profiles. Quantitative analyses were performed to compare pre-instruction NOS conceptions between groups as well as pre to post changes within groups and between groups. Both SSI and Content groups showed significant gains in most NOS themes, but between-group gains were not significantly different. Qualitative analysis of post-instruction responses, however, revealed that students in the SSI group tended to use examples to describe their views of the social/cultural NOS. The findings support SSI contexts as effective for promoting gains in students' NOS understanding and suggest that these contexts facilitate nuanced conceptions that should be further explored.

  6. An initial examination of Singaporean seventh and eighth graders' views of nature of science

    NASA Astrophysics Data System (ADS)

    Lin, Tzung-Jin; Goh, Amos Yoong Shin; Chai, Ching Sing; Tsai, Chin-Chung

    2013-07-01

    Background and purpose . Research in nature of science (NOS) among Asia-Pacific countries such as Singapore is arguably scarce. This study aimed to survey Singaporean secondary school students' views of NOS with a newly developed instrument named Students' Views of Nature of Science (SVNOS), which included various key aspects of NOS that are generally agreed upon by the science education community. Moreover, the relations between some demographic factors, including gender and grade, and students' views of NOS were explored. Sample, design and method In total, 359 Singaporean seventh and eighth graders were invited to participate in this survey. The reliability, validity and structure of the SVNOS instrument were ensured by confirmatory factor analysis. A two-way multivariate analysis of variance was then conducted to determine the interaction effects between the gender variable and the grade-level variable. Results and conclusion The results indicated that the SVNOS instrument is reliable and valid to assess students' views of NOS regarding seven distinct NOS dimensions. The male students were more prone to have constructivist-oriented views of NOS in the most of the SVNOS dimensions, while the female students conveyed more non-objective views of NOS. In addition, the eighth graders revealed more empiricist-oriented views of NOS than the seventh graders in several SVNOS dimensions. This result seems to contradict the results of previous studies that students' views of NOS may reflect a developmental trend with their increasing educational experiences.

  7. The "General Aspects" Conceptualization as a Pragmatic and Effective Means to Introducing Students to Nature of Science

    ERIC Educational Resources Information Center

    Kampourakis, Kostas

    2016-01-01

    Teaching about nature of science (NOS) is considered as an important goal of science education in various countries. Extensive empirical research about how some aspects of NOS can be effectively taught is also available. The most widely adopted conceptualization of NOS is based on a small number of general aspects of NOS, which fall into two…

  8. Students' Environmental NOS Views, Compassion, Intent, and Action: Impact of Place-Based Socioscientific Issues Instruction

    ERIC Educational Resources Information Center

    Herman, Benjamin C.

    2018-01-01

    Preparing students to achieve the lofty goal of functional scientific literacy entails addressing the normative and non-normative facets of socioscientific issues (SSI) such as scientific processes, the nature of science (NOS) and diverse sociocultural perspectives. SSI instructional approaches have demonstrated some efficacy for promoting…

  9. The Importance of Teaching and Learning Nature of Science in the Early Childhood Years

    ERIC Educational Resources Information Center

    Akerson, Valarie L.; Buck, Gayle A.; Donnelly, Lisa A.; Nargund-Joshi, Vanashri; Weiland, Ingrid S.

    2011-01-01

    Though research has shown that students do not have adequate understandings of nature of science (NOS) by the time they exit high school, there is also evidence that they have not received NOS instruction that would enable them to develop such understandings. How early is "too early" to teach and learn NOS? Are students, particularly young…

  10. Scientists Taking a Nature of Science Course: Beliefs and Learning Outcomes of Career Switchers

    ERIC Educational Resources Information Center

    Peters-Burton, Erin

    2016-01-01

    The purpose of the study was to examine what scientists studying to become teachers know about the nature of science (NOS) before, during and after a course focused on NOS. The 16 scientists had an average of 9.7 years of work experience. The course was structured to teach knowledge about the aspects of NOS, demonstrate effective methods of…

  11. Exploring the Conceptions of a Science Teacher from Karachi about the Nature of Science

    ERIC Educational Resources Information Center

    Shah, Mir Zaman

    2009-01-01

    The main purpose of this study is to investigate a science teacher's beliefs and understanding of the nature of science (NOS) in order to be able to relate these beliefs about the NOS to classroom practice and therefore student experience. Teachers' beliefs about the NOS are embedded in their experiences of learning and teaching science and hence,…

  12. Examining the Affordances of Dual Cognitive Processing to Explain the Development of High School Students' Nature of Science Views

    NASA Astrophysics Data System (ADS)

    Jackson, Luke M.

    This mixed method study was aimed at examining the influence of dual processing (Type 1 and Type 2 thinking) on the development of high school students' nature of science (NOS) views. Type 1 thinking is intuitive, experiential, and heuristic. Type 2 thinking is rational, analytical, and explicit. Three research questions were asked: (1) Do the experiential process (Type 1) and the logical process (Type 2) influence the development of students' NOS views? (2) If there is an influence on students' NOS views, then what is the nature of relationship between the experiential process (Type 1) and the development of NOS views? (3) What is the nature of relationship between the logical process (Type 2) and the development of NOS views? The Views of Nature of Science Questionnaire C (VNOS-C; Lederman, Abd-El-Khalick, Bell, & Schwartz, 2002) was administered to 29 high school students at the beginning and at the end of an explicit-reflective NOS intervention offered in an Advanced Placement environmental science course. Changes in students' NOS views were calculated through a chi-square test and examining the percentage of students holding NOS views at various levels of sophistication. With the chi-square goodness of fit test performed, the relationship between pre and post NOS scores was not significant, X2(3, 29) = 4.78, p <.05. The informed and preinformed NOS views increased (14%, 17%) in frequency while the mixed and uninformed NOS views decreased (i.e. improved 26%, 24%) in frequency from pre to posttest. The reading discussions were coded based on the EBR framework (Furtak et al., 2010) to analyze the use of dual processing. Type1 and Type 2 thinking were both used during the intervention and reading reflections. Type 2 thinking was more prominent when analyzing a problem, formulating a hypothesis, or stating logical claims. The association of NOS education and Type 1 and Type 2 thinking in scientific literacy was examined, and implications and future research are

  13. Fostering Pre-Service Teachers' Views about Nature of Science: Evaluation of a New STEM Curriculum

    ERIC Educational Resources Information Center

    Krell, Moritz; Koska, Johannes; Penning, Fenna; Krüger, Dirk

    2015-01-01

    Background: An elaborated understanding of Nature of Science (NOS) is seen as an important part of scientific literacy. In order to enable teachers to adequately discuss NOS in their lessons, various approaches have recently been employed to improve teachers' understanding of NOS. Purpose: This study investigated the effect of participating in a…

  14. Relationship Between Soil Type and N2O Reductase Genotype (nosZ) of Indigenous Soybean Bradyrhizobia: nosZ-minus Populations are Dominant in Andosols

    PubMed Central

    Shiina, Yoko; Itakura, Manabu; Choi, Hyunseok; Saeki, Yuichi; Hayatsu, Masahito; Minamisawa, Kiwamu

    2014-01-01

    Bradyrhizobium japonicum strains that have the nosZ gene, which encodes N2O reductase, are able to mitigate N2O emissions from soils (15). To examine the distribution of nosZ genotypes among Japanese indigenous soybean bradyrhizobia, we isolated bradyrhizobia from the root nodules of soybean plants inoculated with 32 different soils and analyzed their nosZ and nodC genotypes. The 1556 resultant isolates were classified into the nosZ+/nodC+ genotype (855 isolates) and nosZ−/nodC+ genotype (701 isolates). The 11 soil samples in which nosZ− isolates significantly dominated (P < 0.05; the χ2 test) were all Andosols (a volcanic ash soil prevalent in agricultural fields in Japan), whereas the 17 soil samples in which nosZ+ isolates significantly dominated were mainly alluvial soils (non-volcanic ash soils). This result was supported by a principal component analysis of environmental factors: the dominance of the nosZ− genotype was positively correlated with total N, total C, and the phosphate absorption coefficient in the soils, which are soil properties typical of Andosols. Internal transcribed spacer sequencing of representative isolates showed that the nosZ+ and nosZ− isolates of B. japonicum fell mainly into the USDA110 (BJ1) and USDA6 (BJ2) groups, respectively. These results demonstrated that the group lacking nosZ was dominant in Andosols, which can be a target soil type for an N2O mitigation strategy in soybean fields. We herein discussed how the nosZ genotypes of soybean bradyrhizobia depended on soil types in terms of N2O respiration selection and genomic determinants for soil adaptation. PMID:25476067

  15. A study of elementary teachers' conceptions of nature of science and their beliefs about the developmental appropriateness and importance of nature of science throughout a professional development program

    NASA Astrophysics Data System (ADS)

    Adibelli, Elif

    This qualitative study aimed to explore the changes in elementary science teachers' conceptions of nature of science (NOS) and their beliefs about the developmental appropriateness and importance of NOS after participating in an academic, year-long professional development program (PDP) as well as the factors facilitating these changes. The PDP consisted of two phases. In the first phase, the participants received NOS training designed with an explicit-reflective instructional approach. In the second phase, the participants implemented several NOS training activities in their classrooms. Four elementary science teachers who volunteered and completed all components of the PDP (i.e., the NOS training and the NOS teaching) comprised the participants of the present study. A multiple-embedded case study design was employed to explore the changes in the elementary science teachers' conceptions of NOS and their beliefs about the developmental appropriateness and importance of NOS. The study data were collected from multiple sources. The primary data sources included (a) Views of Nature of Science Elementary School Version 2 (VNOS-D2) questionnaire (Lederman & Khishfe, 2002), (b) Ideas about Science for Early Elementary (K-4) Students questionnaire (Sweeney, 2010), and (c) follow-up semi-structured interviews. The secondary data sources included videotaping of meetings with teachers, reflective field notes, and artifacts produced by teachers and their students. Data were analyzed using Yin's (1994, 2003) analytic tactics of pattern matching, explanation building, and cross-case synthesis. The findings of the study revealed that the elementary science teachers showed gradual, but substantial changes in their conceptions, and beliefs about the developmental appropriateness and importance of the NOS aspects over the course of participation in the PDP. Moreover, the participants identified nine components in the PDP that facilitated these changes in their conceptions, and

  16. Resveratrol protects rats from Aβ-induced neurotoxicity by the reduction of iNOS expression and lipid peroxidation.

    PubMed

    Huang, Tai-Chun; Lu, Kwok-Tung; Wo, Yu-Yuan Peter; Wu, Yao-Ju; Yang, Yi-Ling

    2011-01-01

    Alzheimer disease (AD) is an age-dependent neurodegenerative disease characterized by the formation of β-amyloid (Aβ)-containing senile plaque. The disease could be induced by the administration of Aβ peptide, which was also known to upregulate inducible nitric oxide synthase (iNOS) and stimulate neuronal apoptosis. The present study is aimed to elucidate the cellular effect of resveratrol, a natural phytoestrogen with neuroprotective activities, on Aβ-induced hippocampal neuron loss and memory impairment. On adult Sprague-Dawley rats, we found the injection of Aβ could result in a significant impairment in spatial memory, a marked increase in the cellular level of iNOS and lipid peroxidation, and an apparent decrease in the expression of heme oxygenase-1 (HO-1). By combining the treatment with Aβ, resveratrol was able to confer a significant improvement in spatial memory, and protect animals from Aβ-induced neurotoxicity. These neurological protection effects of resveratrol were associated with a reduction in the cellular levels of iNOS and lipid peroxidation and an increase in the production of HO-1. Moreover, the similar neurological and cellular response were also observed when Aβ treatment was combined with the administration of a NOS inhibitor, N(G)-nitro-L-arginine methyl ester hydrochloride (L-NAME). These findings strongly implicate that iNOS is involved in the Aβ-induced lipid peroxidation and HO-1 downregulation, and resveratrol protects animals from Aβ-induced neurotoxicity by suppressing iNOS production.

  17. Resveratrol Protects Rats from Aβ-induced Neurotoxicity by the Reduction of iNOS Expression and Lipid Peroxidation

    PubMed Central

    Wo, Yu-Yuan Peter; Wu, Yao-Ju; Yang, Yi-Ling

    2011-01-01

    Alzheimer disease (AD) is an age-dependent neurodegenerative disease characterized by the formation of β–amyloid (Aβ)-containing senile plaque. The disease could be induced by the administration of Aβ peptide, which was also known to upregulate inducible nitric oxide synthase (iNOS) and stimulate neuronal apoptosis. The present study is aimed to elucidate the cellular effect of resveratrol, a natural phytoestrogen with neuroprotective activities, on Aβ-induced hippocampal neuron loss and memory impairment. On adult Sprague-Dawley rats, we found the injection of Aβ could result in a significant impairment in spatial memory, a marked increase in the cellular level of iNOS and lipid peroxidation, and an apparent decrease in the expression of heme oxygenase-1 (HO-1). By combining the treatment with Aβ, resveratrol was able to confer a significant improvement in spatial memory, and protect animals from Aβ-induced neurotoxicity. These neurological protection effects of resveratrol were associated with a reduction in the cellular levels of iNOS and lipid peroxidation and an increase in the production of HO-1. Moreover, the similar neurological and cellular response were also observed when Aβ treatment was combined with the administration of a NOS inhibitor, N(G)-nitro-L-arginine methyl ester hydrochloride (L-NAME). These findings strongly implicate that iNOS is involved in the Aβ-induced lipid peroxidation and HO-1 downregulation, and resveratrol protects animals from Aβ-induced neurotoxicity by suppressing iNOS production. PMID:22220203

  18. A Structural Model of Prospective Science Teachers' Nature of Science Views

    ERIC Educational Resources Information Center

    Mugaloglu, Ebru Z.; Bayram, Hale

    2010-01-01

    This study aims to establish a viable structural model of prospective science teachers' nature of science (NOS) views, which could be used as an analytical tool for understanding the complex relationships between prospective teachers' conceptions of NOS and factors possibly affecting their conceptions. In order to construct such a model, likely…

  19. Thai In-Service Science Teachers' Conceptions of the Nature of Science

    ERIC Educational Resources Information Center

    Buaraphan, Khajornsak

    2009-01-01

    Understanding of the Nature of Science (NOS) serves as one of the desirable characteristics of science teachers. The current study attempted to explore 101 Thai in-service science teachers' conceptions of the NOS, particularly scientific knowledge, the scientific method, scientists' work, and scientific enterprise, by using the Myths of Science…

  20. Exploring Elementary Science Methods Course Contexts to Improve Preservice Teachers' NOS of Science Conceptions and Understandings of NOS Teaching Strategies

    ERIC Educational Resources Information Center

    Akerson, Valarie L.; Weiland, Ingrid; Rogers, Meredith Park; Pongsanon, Khemmawaddee; Bilican, Kader

    2014-01-01

    We explored adaptations to an elementary science methods course to determine how varied contexts could improve elementary preservice teachers' conceptions of NOS as well as their ideas for teaching NOS to elementary students. The contexts were (a) NOS Theme in which the course focused on the teaching of science through the consistent teaching…

  1. Genetics instruction with history of science: Nature of science learning

    NASA Astrophysics Data System (ADS)

    Kim, Sun Young

    2007-12-01

    This study explored the effect of history of genetics in teaching genetics and learning the nature of science (NOS). A quasi-experimental control group research design with pretests, posttests, and delayed posttests was used, combining qualitative data and quantitative data. Two classes which consisted of tenth grade biology students participated in this study. The present study involved two instructional interventions, Best Practice Instruction with History of Genetics (BPIw/HG) and Best Practice Instruction (BPI). The experimental group received BPIw/HG utilizing various historical materials from the history of genetics, while the control group was not introduced to historical materials. Scientific Attitude Inventory II, Genetics Terms' Definitions with Concept Mapping (GTDCM), NOS Terms' Definitions with Concept Mapping (NTDCM), and View of Nature of Science (VNOS-C) were used to investigate students' scientific attitude inventory, and their understanding of genetics as well as the NOS. The results showed that students' scientific attitude inventory, and their understanding of genetics and the NOS were not statistically significantly different in the pretest (p>.05). After the intervention, the experimental group of students who received BPIw/HG demonstrated better understanding of the NOS. NTDCM results showed that the experimental group was better in defining the NOS terms and constructing a concept map ( p<.01). In addition, the experimental group retained their understanding of the NOS two-months after the completion of the intervention, showing no statistically significant difference between the posttest and the delayed posttest of NTDCM (p>.05). Further, VNOS-C data indicated that a greater percentage of the experimental group than the control group improved their understanding of the NOS. However, the two groups' understanding of genetics concepts did not show any statistically significant difference in the pretest, the posttest, and the delayed posttest

  2. Myths about the Nature of Technology and Engineering

    ERIC Educational Resources Information Center

    Kruse, Jerrid; Edgerly, Hallie; Easter, Jaclyn; Wilcox, Jesse

    2017-01-01

    Increasingly, science teachers are expected to devote instruction to technology and engineering, as encouraged by the Next Generation Science Standards (NGSS Lead States 2013). Just as scientific literacy requires understanding the nature of science (NOS), technological literacy must include understanding the philosophy and nature of technology…

  3. How Are the Perceptions of High School Students and Teachers on NOS as a Knowledge Type Presented in Schools in Terms of "Importance" and "Interest"?

    ERIC Educational Resources Information Center

    Sahin, Canan Tunc; Koksal, Mustafa Serdar

    2010-01-01

    The common resources of the misunderstandings on nature on science (NOS) are textbooks, teachers and media. However, students with their affective characteristics such as value given to any task related to NOS might also be a resource for misunderstandings. With this idea in mind, the perceptions of teachers and their students in Anatolian Teacher…

  4. Recapitulating the History of Sickle-Cell Anemia Research: Improving Students' NOS Views Explicitly and Reflectively

    ERIC Educational Resources Information Center

    Howe, Eric Michael; Rudge, David Wyss

    2005-01-01

    This paper provides an argument in favor of a specific pedagogical method of using the history of science to help students develop more informed views about nature of science (NOS) issues. The paper describes a series of lesson plans devoted to encouraging students to engage, "unbeknownst to them", in similar reasoning that led…

  5. Undergraduate honors students' images of science: Nature of scientific work and scientific knowledge

    NASA Astrophysics Data System (ADS)

    Wallace, Michael L.

    This exploratory study assessed the influence of an implicit, inquiry-oriented nature of science (NOS) instructional approach undertaken in an interdisciplinary college science course on undergraduate honor students' (UHS) understanding of the aspects of NOS for scientific work and scientific knowledge. In this study, the nature of scientific work concentrated upon the delineation of science from pseudoscience and the value scientists place on reproducibility. The nature of scientific knowledge concentrated upon how UHS view scientific theories and how they believe scientists utilize scientific theories in their research. The 39 UHS who participated in the study were non-science majors enrolled in a Honors College sponsored interdisciplinary science course where the instructors took an implicit NOS instructional approach. An open-ended assessment instrument, the UFO Scenario, was designed for the course and used to assess UHS' images of science at the beginning and end of the semester. The mixed-design study employed both qualitative and quantitative techniques to analyze the open-ended responses. The qualitative techniques of open and axial coding were utilized to find recurring themes within UHS' responses. McNemar's chi-square test for two dependent samples was used to identify whether any statistically significant changes occurred within responses from the beginning to the end of the semester. At the start of the study, the majority of UHS held mixed NOS views, but were able to accurately define what a scientific theory is and explicate how scientists utilize theories within scientific research. Postinstruction assessment indicated that UHS did not make significant gains in their understanding of the nature of scientific work or scientific knowledge and their overall images of science remained static. The results of the present study found implicit NOS instruction even with an extensive inquiry-oriented component was an ineffective approach for modifying UHS

  6. An Analysis of South African Grade 9 Natural Sciences Textbooks for Their Representation of Nature of Science

    ERIC Educational Resources Information Center

    Ramnarain, Umesh Dewnarain; Chanetsa, Tarisai

    2016-01-01

    This article reports on an analysis and comparison of three South African Grade 9 (13-14 years) Natural Sciences textbooks for the representation of nature of science (NOS). The analysis was framed by an analytical tool developed and validated by Abd-El-Khalick and a team of researchers in a large-scale study on the high school textbooks in the…

  7. Relationship between endothelial nitric oxide synthase (eNOS) and natural history of intracranial aneurysms: meta-analysis.

    PubMed

    Paschoal, Eric Homero Albuquerque; Yamaki, Vitor Nagai; Teixeira, Renan Kleber Costa; Paschoal Junior, Fernando Mendes; Jong-A-Liem, Glaucia Suzanna; Teixeira, Manoel Jacobsen; Yamada, Elizabeth Sumi; Ribeiro-Dos-Santos, Ândrea; Bor-Seng-Shu, Edson

    2018-01-01

    The aneurysmal subarachnoid hemorrhage is a major public health problem described as a sudden drastic event with no warning symptoms and high morbidity and mortality rates. The role of the endothelial isoform of nitric oxide synthase gene polymorphism in intracranial aneurysms (IAs) is still a matter of controversy with divergent findings among European, American, and Asian populations. Our study purposed to test the association between intracranial aneurysms formation and nitric oxide gene polymorphisms through a systematic review and meta-analysis. Systematic search on Medline, Lilacs, and EMBASE was performed. The primary search resulted in 139 papers, out of which 9 met our inclusion criteria after a full text analysis. The dominant T786C model found a significant association with IA (OR 1.22, 95 % CI 1.04-1.44, p = 0.01), so did studies of the recessive T786C model (OR 0.37, 95 % CI 0.30-0.45, p < 0.0001) but with opposite effect. Our findings support the presence of the T786C polymorphism as a predictor for the development of intracranial aneurysm in the cerebral vascular system. More studies are necessary in order to elucidate the pathways of the endothelial nitric oxide synthase (eNOS) in cerebrovascular diseases and in defining how different allelic combinations of the eNOS gene single-nucleotide polymorphism (SNP) could favor this pathological process.

  8. Conceptions of the nature of science and worldviews of preservice elementary science teachers in Taiwan

    NASA Astrophysics Data System (ADS)

    Liu, Shiang-Yao

    This exploratory investigation aimed to identify preservice science teachers' conceptions of the nature of science (NOS), and worldviews that represent their culturally dependent beliefs about the world, in the context of Taiwan. The interrelationships between the responses elicited from both the assessments of NOS understandings and worldviews were examined. Participants included 54 third-year students enrolled in the departments of science education and mathematics education at a teachers college. Their worldviews and NOS conceptions were tabulated by two questionnaires and 14 of them were purposefully selected to participate follow-up interviews. The worldview questionnaire contained five open-ended items, of which each examines one of the worldview domains in Kearney's model (1984). The NOS questionnaire consisting of nine open-ended questions was developed, specifically addressing cultural characteristics, to assess participants' views on the development of scientific knowledge. An anthropocentric-moderate continuum emerged to describe participants' views of the humanity's relationship with Nature. It was found that participants with informed NOS conceptions were more likely to emphasize harmony with Nature, recognize the limitations of scientific knowledge, and accept the idea that science involves subjective and cultural components. On the other hand, participants who provided a pragmatic perspective of Nature seemed to possess narrow views about the scientific enterprises by describing science as close to technology and as a materialistic benefit. Authoritarianism was also a noticeable cultural trait hindering some participants from reflecting on the values inherent to the development of scientific knowledge, and also prohibiting them from searching empirical evidence to solve problems. It was found that there were differences between science education and mathematics education majors in their worldviews and NOS understandings. The results in this study not

  9. Clinicopathological analysis in PTCL-NOS with CADM1 expression.

    PubMed

    Kato, Takeharu; Miyoshi, Hiroaki; Kobayashi, Seiichiro; Yoshida, Noriaki; Imaizumi, Yoshitaka; Seto, Masao; Uchimaru, Kaoru; Miyazaki, Yasushi; Ohshima, Koichi

    2017-11-01

    Peripheral T cell lymphoma, not otherwise specified (PTCL-NOS), is a heterogeneous disease with respect to clinicopathological features. Cell adhesion molecule 1 (CADM1) has been reported to be ectopically expressed in adult T cell leukaemia/lymphoma (ATLL). However, the frequency of CADM1 expression remains unknown in peripheral T cell lymphomas. In the current study, CADM1 expression was analysed in 88 PTCL-NOS patients. CADM1 was expressed in 14 of 88 (15.9%) PTCL-NOS cases, and its expression was associated with C-C chemokine receptor type 4 (CCR4) expression and nuclear atypia. CADM1-positive PTCL-NOS cases (10/74) had a significantly poorer prognosis than CADM1-negative cases (64/74) (P = 0.001). Multivariate analysis confirmed that CADM1 expression was an independent prognostic factor in PTCL-NOS. These findings suggest that CADM1 expression is a novel prognostic factor for PTCL-NOS.

  10. Identification of hamster inducible nitric oxide synthase (iNOS) promoter sequences that influence basal and inducible iNOS expression

    PubMed Central

    Saldarriaga, Omar A.; Travi, Bruno L.; Choudhury, Goutam Ghosh; Melby, Peter C.

    2012-01-01

    IFN-γ/LPS-activated hamster (Mesocricetus auratus) macrophages express significantly less iNOS (NOS2) than activated mouse macrophages, which contributes to the hamster's susceptibility to intracellular pathogens. We determined a mechanism responsible for differences in iNOS promoter activity in hamsters and mice. The HtPP (1.2 kb) showed low basal and inducible promoter activity when compared with the mouse, and sequences within a 100-bp region (−233 to −133) of the mouse and hamster promoters influenced this activity. Moreover, within this 100 bp, we identified a smaller region (44 bp) in the mouse promoter, which recovered basal promoter activity when swapped into the hamster promoter. The mouse homolog (100-bp region) contained a cis-element for NF-IL-6 (−153/−142), which was absent in the hamster counterpart. EMSA and supershift assays revealed that the hamster sequence did not support the binding of NF-IL-6. Introduction of a functional NF-IL-6 binding sequence into the hamster promoter or its alteration in the mouse promoter revealed the critical importance of this transcription factor for full iNOS promoter activity. Furthermore, the binding of NF-IL-6 to the iNOS promoter (−153/−142) in vivo was increased in mouse cells but was reduced in hamster cells after IFN-γ/LPS stimulation. Differences in the activity of the iNOS promoters were evident in mouse and hamster cells, so they were not merely a result of species-specific differences in transcription factors. Thus, we have identified unique DNA sequences and a critical transcription factor, NF-IL-6, which contribute to the overall basal and inducible expression of hamster iNOS. PMID:22517919

  11. An Investigation of Zimbabwe High School Chemistry Students' Laboratory Work-Based Images of the Nature of Science

    ERIC Educational Resources Information Center

    Vhurumuku, Elaosi; Holtman, Lorna; Mikalsen, Oyvind; Kolsto, Stein D.

    2006-01-01

    This study investigates the proximal and distal images of the nature of science (NOS) that A-level students develop from their participation in chemistry laboratory work. We also explored the nature of the interactions among the students' proximal and distal images of the NOS and students' participation in laboratory work. Students' views of the…

  12. The nature of science and the preservice elementary teacher: Changes in understanding and practice

    NASA Astrophysics Data System (ADS)

    Rivas, Michael Gerald

    This action research project studies preservice elementary teachers in a science methods course. The purpose of this research project was to enhance preservice teachers' understanding of specific nature of science (NOS) tenets so as to promote equity and access within the elementary science classroom. In particular, I chose five NOS tenets that were listed in the first chapter of the AAAS (1989) document titled, "The Nature of Science," and connected them to equitable educational goals and practices. The theoretical framework guiding this study came from bodies of scholarship relating to the NOS, social constructivism, and action research. This study addressed the following three questions: (1) What opportunities were provided the preservice teachers so that they could enhance their understandings of the NOS? (2) What were the changes in preservice teachers' understanding of the NOS as a result? (3) How did the prospective teachers' understandings of the NOS translate into their classroom practice? The analysis revealed that the science methods course's operational curriculum consisted of implicit and explicit teaching of the NOS, as well as intended and untended NOS tenets. The prospective teachers initially held a limited view of the NOS, but by the end of the course their view had been enhanced. In addition, the participants made direct connections between their new understandings of the NOS and equity and access in the science classroom. In their teaching, the preservice teachers as a group implicitly taught all five of the NOS tenets. In fact, a majority taught three of the five intended tenets. Explicitly, only one tenet was taught, but it was taught with a direct connection to making the science classroom more inclusive. The findings of this study indicate that preservice teachers can have their views of the NOS enhanced even though they may have experienced years of deficient science instruction. They pointed out that this enhanced view of the NOS can be

  13. ET-1 Stimulates Superoxide Production by eNOS Following Exposure of Vascular Endothelial Cells to Endotoxin.

    PubMed

    Gopalakrishna, Deepak; Pennington, Samantha; Karaa, Amel; Clemens, Mark G

    2016-07-01

    significantly monomerized the eNOS homodimer that was inhibited by sepiapterin loading. The two concomitant phenomena of decreased NO production and increased ROS formation seem to be multifactorial in nature with ROS production dependent upon pterin availability.

  14. Controversy as a Blind Spot in Teaching Nature of Science. Why the Range of Different Positions Concerning Nature of Science Should Be an Issue in the Science Classroom

    NASA Astrophysics Data System (ADS)

    Kötter, Mario; Hammann, Marcus

    2017-07-01

    In this article, the argument is put forth that controversies about the scope and limits of science should be considered in Nature of Science (NOS) teaching. Reference disciplines for teaching NOS are disciplines, which reflect upon science, like philosophy of science, history of science, and sociology of science. The culture of these disciplines is characterized by controversy rather than unified textbook knowledge. There is common agreement among educators of the arts and humanities that controversies in the reference disciplines should be represented in education. To teach NOS means to adopt a reflexive perspective on science. Therefore, we suggest that controversies within and between the reference disciplines are relevant for NOS teaching and not only the NOS but about NOS should be taught, too. We address the objections that teaching about NOS is irrelevant for real life and too demanding for students. First, we argue that science-reflexive meta-discourses are relevant for students as future citizens because the discourses occur publicly in the context of sociopolitical disputes. Second, we argue that it is in fact necessary to reduce the complexity of the above-mentioned discourses and that this is indeed possible, as it has been done with other reflexive elements in science education. In analogy to the German construct Bewertungskompetenz (which means the competency to make informed ethical decisions in scientific contexts), we suggest epistemic competency as a goal for NOS teaching. In order to do so, science-reflexive controversies must be simplified and attitudes toward science must be considered. Discourse on the scientific status of potential pseudoscience may serve as an authentic and relevant context for teaching the controversial nature of reflexion on science.

  15. Recapitulating the History of Sickle-Cell Anemia Research: Improving Students' NOS Views Explicitly and Reflectively

    NASA Astrophysics Data System (ADS)

    Howe, Eric Michael; Wÿss Rudge, David

    This paper provides an argument in favor of a specific pedagogical method of using the history of science to help students develop more informed views about nature of science (NOS) issues. The paper describes a series of lesson plans devoted to encouraging students to engage, unbeknownst to them, in similar reasoning that led scientists to understand sickle-cell anemia from the perspective of multiple subdisciplines in biology. Students pursue their understanding of a "mystery disease"; by means of a series of open-ended problems that invite them to discuss it from the perspective of anatomy, physiology, ecology, evolution, and molecular and cell biology. Throughout this unit, instructors incorporate techniques that invite students to explicitly and reflectively discuss various NOS issues with reference to this example and more generally. It is argued on the grounds of constructivist tenets that this pedagogy has substantial advantages over more implicit approaches. The findings of an empirical study using an open-ended survey and follow-up, semi-structured interviews to assess students' pre- and post-instruction NOS conceptions support the efficacy of this approach.

  16. Controversy as a Blind Spot in Teaching Nature of Science: Why the Range of Different Positions Concerning Nature of Science Should Be an Issue in the Science Classroom

    ERIC Educational Resources Information Center

    Kötter, Mario; Hammann, Marcus

    2017-01-01

    In this article, the argument is put forth that controversies about the scope and limits of science should be considered in Nature of Science (NOS) teaching. Reference disciplines for teaching NOS are disciplines, which reflect upon science, like philosophy of science, history of science, and sociology of science. The culture of these disciplines…

  17. A Look into Students' Retention of Acquired Nature of Science Understandings

    ERIC Educational Resources Information Center

    Khishfe, Rola

    2015-01-01

    Having the learning and retention of science content and skills as a goal of scientific literacy, it is significant to study the issue of retention as it relates to teaching and learning about nature of science (NOS). Then, the purpose of this study was to investigate the development of NOS understandings of students, and the retention of these…

  18. Understanding How Science Works: The Nature of Science as The Foundation for Science Teaching and Learning

    ERIC Educational Resources Information Center

    McComas, William F.

    2017-01-01

    The nature of science (NOS) is a phrase used to represent the rules of the game of science. Arguably, NOS is the most important content issue in science instruction because it helps students understand the way in which knowledge is generated and validated within the scientific enterprise. This article offers a proposal for the elements of NOS that…

  19. Scientific Communication and the Nature of Science

    NASA Astrophysics Data System (ADS)

    Nielsen, Kristian H.

    2013-09-01

    Communication is an important part of scientific practice and, arguably, may be seen as constitutive to scientific knowledge. Yet, often scientific communication gets cursory treatment in science studies as well as in science education. In Nature of Science (NOS), for example, communication is rarely mentioned explicitly, even though, as will be argued in this paper, scientific communication could be treated as a central component of NOS. Like other forms of communication, scientific communication is socially and symbolically differentiated. Among other things, it encompasses technical language and grammar, lab communications, and peer reviews, all of which will be treated in this paper in an attempt to engage on an empirical and theoretical level with science as communication. Seeing science as a form of communicative action supplements the epistemological view of science that is standard to both NOS and the philosophy of science. Additions to the seven NOS aspects on Lederman's (Handbook of research on science education. Lawrence Erlbaum, Mahwah, pp. 831-879, 2007) list are put forward as well as preliminary thoughts on the inclusion of scientific communication into NOS instruction.

  20. Teachers' Nature of Science Implementation Practices 2-5 Years after Having Completed an Intensive Science Education Program

    ERIC Educational Resources Information Center

    Herman, Benjamin C.; Clough, Michael P.; Olson, Joanne K.

    2013-01-01

    Few, if any, studies have examined the impact of nature of science (NOS) instruction on science teachers' practices 2 or more years after completing a science teacher education program. Extant studies on preservice and first-year teachers' NOS teaching practices have had disappointing results, with few teachers valuing NOS as a cognitive objective…

  1. Cross-Cultural Comparisons of Undergraduate Student Views of the Nature of Science

    ERIC Educational Resources Information Center

    Arino de la Rubia, Leigh S.; Lin, Tzung-Jin; Tsai, Chin-Chung

    2014-01-01

    Past studies investigating university level students' views of nature of science (NOS) were relatively few and most of them were conducted in Western countries. This paper focuses upon comparing the quantitative patterns in Western (US Caucasian and African-American) and non-Western (Taiwanese) students' views of NOS (VNOS) by adopting a survey…

  2. Development and Validation of Nature of Science Instrument for Elementary School Students

    ERIC Educational Resources Information Center

    Hacieminoglu, Esme; Yilmaz-Tüzün, Özgül; Ertepinar, Hamide

    2014-01-01

    The purposes of this study were to develop and validate an instrument for assessing elementary students' nature of science (NOS) views and to explain the elementary school students' NOS views, in terms of varying grade levels and gender. The sample included 782 students enrolled in sixth, seventh, and eighth grades. Exploratory factor analysis…

  3. Changes in Pre-service Science Teachers' Understandings After Being Involved in Explicit Nature of Science and Socioscientific Argumentation Processes

    NASA Astrophysics Data System (ADS)

    Kutluca, A. Y.; Aydın, A.

    2017-08-01

    The study explored the changes in pre-service science teachers' understanding of the nature of science and their opinions about the nature of science, science teaching and argumentation after their participation in explicit nature of science (NOS) and socioscientific argumentation processes. The participants were 56 third-grade pre-service science teachers studying in a state university in Turkey. The treatment group comprised 27 participants, and there were 29 participants in the comparison group. The comparison group participants were involved in a student-centred science-teaching process, and the participants of the treatment group were involved in explicit NOS and socioscientific argumentation processes. In the study, which lasted a total of 11 weeks, a NOS-as-argumentation questionnaire was administered to all the participants to determine their understanding of NOS at the beginning and end of the data collection process, and six random participants of the treatment group participated in semi-structured interview questions in order to further understand their views regarding NOS, science teaching and argumentation. Qualitative and quantitative data analysis revealed that the explicit NOS and socioscientific argumentation processes had a significant effect on pre-service science teachers' NOS understandings. Furthermore, NOS, argumentation and science teaching views of the participants in the treatment group showed a positive change. The results of this study are discussed in light of the related literature, and suggestions are made within the context of contribution to science-teaching literature, improvement of education quality and education of pre-service teachers.

  4. St36 electroacupuncture activates nNOS, iNOS and ATP-sensitive potassium channels to promote orofacial antinociception in rats.

    PubMed

    Almeida, R T; Galdino, G; Perez, A C; Silva, G; Romero, T R; Duarte, I D

    2017-02-01

    Orofacial pain is pain perceived in the face and/or oral cavity, generally caused by diseases or disorders of regional structures, by dysfunction of the nervous system, or through referral from distant sources. Treatment of orofacial pain is mainly pharmacological, but it has increased the number of reports demonstrating great clinical results with the use of non-pharmacological therapies, among them electroacupuncture. However, the mechanisms involved in the electroacupuncture are not well elucidated. Thus, the present study investigate the involvement of the nitric oxide synthase (NOS) and ATP sensitive K + channels (KATP) in the antinociception induced by electroacupuncture (EA) at acupoint St36. Thermal nociception was applied in the vibrissae region of rats, and latency time for face withdrawal was measured. Electrical stimulation of acupoint St36 for 20 minutes reversed the thermal withdrawal latency and this effect was maintained for 150 min. Intraperitoneal administration of specific inhibitors of neuronal nitric oxide synthase (nNOS), inducible nitric oxide synthase (iNOS) and a KATP channels blocker reversed the antinociception induced by EA. Furthermore, nitrite concentration in cerebrospinal fluid (CSF) and plasma, increased 4 and 3-fold higher, respectively, after EA. This study suggests that NO participates of antinociception induced by EA by nNOS, iNOS and ATP-sensitive K + channels activation.

  5. Dilemmas in examining understanding of nature of science in Vietnam

    NASA Astrophysics Data System (ADS)

    Thao-Do, Thi Phuong; Yuenyong, Chokchai

    2017-06-01

    Scholars proved nature of science (NOS) has made certain contributions to science teaching and learning. Nonetheless, what, how and how much NOS should be integrated in the science curriculum of each country cannot be a benchmark, due to the influence of culture and society. Before employing NOS in a new context, it should be carefully studied. In assessing views of NOS in Vietnam, a developing country with Eastern culture where the NOS is not consider a compulsory learning outcome, there are several issues that researchers and educators should notice to develop an appropriate instrument that can clearly exhibit a NOS view of Vietnamese. They may include: time for the survey; length, content, type, and terms of the questionnaire; Vietnamese epistemology and philosophy; and some other Vietnamese social and cultural aspects. The most important reason for these considerations is that a Vietnamese view of NOS and NOS assessment possibly differs from the Western ideas due to the social and cultural impact. As a result, a Western assessment tool may become less effective in an Eastern context. The suggestions and implications in this study were derived from a prolonged investigation on Vietnamese science teacher educators and student teachers of School of Education, at Can Tho University, a State University in Mekong Delta region, Vietnam.

  6. Nature of Science as Portrayed in the Middle School Science and Technology Curriculum: The Case of Turkey

    ERIC Educational Resources Information Center

    Izci, Kemal

    2017-01-01

    Representation of nature of science (NOS) within curricula including standards, grade level expectations, and textbooks and their alignment with each other to achieve teaching NOS is crucial. Thus, the aims of the study were to a) assess how NOS is portrayed in standards, grade level expectations and a teacher edition of seventh grade textbook of…

  7. eNOS-uncoupling in age-related erectile dysfunction

    PubMed Central

    Johnson, JM; Bivalacqua, TJ; Lagoda, GA; Burnett, AL; Musicki, B

    2011-01-01

    Aging is associated with ED. Although age-related ED is attributed largely to increased oxidative stress and endothelial dysfunction in the penis, the molecular mechanisms underlying this effect are not fully defined. We evaluated whether endothelial nitric oxide synthase (eNOS) uncoupling in the aged rat penis is a contributing mechanism. Correlatively, we evaluated the effect of replacement with eNOS cofactor tetrahydrobiopterin (BH4) on erectile function in the aged rats. Male Fischer 344 ‘young’ (4-month-old) and ‘aged’ (19-month-old) rats were treated with a BH4 precursor sepiapterin (10 mg/kg intraperitoneally) or vehicle for 4 days. After 1-day washout, erectile function was assessed in response to electrical stimulation of the cavernous nerve. Endothelial dysfunction (eNOS uncoupling) and oxidative stress (thiobarbituric acid reactive substances, TBARS) were measured by conducting western blot in penes samples. Erectile response was significantly reduced in aged rats, whereas eNOS uncoupling and TBARS production were significantly increased in the aged rat penis compared with young rats. Sepiapterin significantly improved erectile response in aged rats and prevented increase in TBARS production, but did not affect eNOS uncoupling in the penis of aged rats. These findings suggest that aging induces eNOS uncoupling in the penis, resulting in increased oxidative stress and ED. PMID:21289638

  8. Zinc regulates iNOS-derived nitric oxide formation in endothelial cells.

    PubMed

    Cortese-Krott, Miriam M; Kulakov, Larissa; Opländer, Christian; Kolb-Bachofen, Victoria; Kröncke, Klaus-D; Suschek, Christoph V

    2014-01-01

    Aberrant production of nitric oxide (NO) by inducible NO synthase (iNOS) has been implicated in the pathogenesis of endothelial dysfunction and vascular disease. Mechanisms responsible for the fine-tuning of iNOS activity in inflammation are still not fully understood. Zinc is an important structural element of NOS enzymes and is known to inhibit its catalytical activity. In this study we aimed to investigate the effects of zinc on iNOS activity and expression in endothelial cells. We found that zinc down-regulated the expression of iNOS (mRNA+protein) and decreased cytokine-mediated activation of the iNOS promoter. Zinc-mediated regulation of iNOS expression was due to inhibition of NF-κB transactivation activity, as determined by a decrease in both NF-κB-driven luciferase reporter activity and expression of NF-κB target genes, including cyclooxygenase 2 and IL-1β. However, zinc did not affect NF-κB translocation into the nucleus, as assessed by Western blot analysis of nuclear and cytoplasmic fractions. Taken together our results demonstrate that zinc limits iNOS-derived high output NO production in endothelial cells by inhibiting NF-κB-dependent iNOS expression, pointing to a role of zinc as a regulator of iNOS activity in inflammation.

  9. Zinc regulates iNOS-derived nitric oxide formation in endothelial cells

    PubMed Central

    Cortese-Krott, Miriam M.; Kulakov, Larissa; Opländer, Christian; Kolb-Bachofen, Victoria; Kröncke, Klaus-D.; Suschek, Christoph V.

    2014-01-01

    Aberrant production of nitric oxide (NO) by inducible NO synthase (iNOS) has been implicated in the pathogenesis of endothelial dysfunction and vascular disease. Mechanisms responsible for the fine-tuning of iNOS activity in inflammation are still not fully understood. Zinc is an important structural element of NOS enzymes and is known to inhibit its catalytical activity. In this study we aimed to investigate the effects of zinc on iNOS activity and expression in endothelial cells. We found that zinc down-regulated the expression of iNOS (mRNA+protein) and decreased cytokine-mediated activation of the iNOS promoter. Zinc-mediated regulation of iNOS expression was due to inhibition of NF-κB transactivation activity, as determined by a decrease in both NF-κB-driven luciferase reporter activity and expression of NF-κB target genes, including cyclooxygenase 2 and IL-1β. However, zinc did not affect NF-κB translocation into the nucleus, as assessed by Western blot analysis of nuclear and cytoplasmic fractions. Taken together our results demonstrate that zinc limits iNOS-derived high output NO production in endothelial cells by inhibiting NF-κB-dependent iNOS expression, pointing to a role of zinc as a regulator of iNOS activity in inflammation. PMID:25180171

  10. Design of Chemistry Teacher Education Course on Nature of Science

    NASA Astrophysics Data System (ADS)

    Vesterinen, Veli-Matti; Aksela, Maija

    2013-09-01

    To enhance students' understanding of nature of science (NOS), teachers need adequate pedagogical content knowledge related to NOS. The educational design research study presented here describes the design and development of a pre-service chemistry teacher education course on NOS instruction. The study documents two iterative cycles of problem analysis, design, implementation, and evaluation. The main aims of the study were (1) to create an in-depth and detailed description of the process used in the development of the course and the design solutions produced, and (2) to evaluate how the design solutions affected participants' commitment to teach NOS. Based on the problem analysis based on challenges recognized from the previous research, three design solutions were produced: (1) definition of central dimensions of domain-specific NOS for chemistry education, (2) teaching cycle for explicit and structured opportunities for reflection and discussion, and (3) design assignments to translate NOS understanding into classroom practice. The major data-sources used in the evaluation of the design solutions were the four in-depth interviews conducted after the course. Based on the evaluation, the design solutions supported internalizing understanding of NOS and transforming the understanding to instruction. Supporting the implementation of new innovative teaching practices such as NOS instruction in pre-service teacher education is a challenge. However, the success of the participants in implementing NOS instruction demonstrates, that a pre-service teacher education course can be successful in producing early adopters of NOS instruction and thus might be one of the first steps in injecting NOS instruction into the curriculum.

  11. Teaching about Nature of Science in Secondary Education: A View from Multicultural Classrooms

    ERIC Educational Resources Information Center

    Gandolfi, Haira Emanuela

    2017-01-01

    Teaching about nature of science (NOS) within a science curriculum that is primarily concerned with developing scientific content continues to provide a challenge for teachers. This study of science lessons focuses on whether NOS is being incorporated implicitly or explicitly, and whether epistemic aspects (e.g. models, theories) and social…

  12. Fostering pre-service teachers' views about nature of science: evaluation of a new STEM curriculum

    NASA Astrophysics Data System (ADS)

    Krell, Moritz; Koska, Johannes; Penning, Fenna; Krüger, Dirk

    2015-09-01

    Background: An elaborated understanding of Nature of Science (NOS) is seen as an important part of scientific literacy. In order to enable teachers to adequately discuss NOS in their lessons, various approaches have recently been employed to improve teachers' understanding of NOS. Purpose: This study investigated the effect of participating in a newly developed Science, Technology, Engineering and Mathematics (STEM) curriculum at the Freie Universität Berlin (Germany) on pre-service teachers' NOS views. Program description: In the new STEM curriculum, two versions of explicitly teaching NOS, which are discussed in the literature, have been adopted: the pre-service teachers explicitly reflect upon nature and history of science (version one) as well as conduct own scientific investigations (version two). Sample: N = 76 pre-service teachers from different semester levels (cross-sectional study) who participated in the new STEM curriculum took part in this study (intervention group). As control groups, students who did not partake in the new curriculum participated (pre-service primary (N = 134), science (N = 198), and no-science (N = 161) teachers). Design and methods: In order to allow an economic assessment, a testing instrument with closed-item formats was developed to assess the respondents' views about six NOS aspects. Results: The intervention group shows significantly more elaborated NOS views than a relevant control group (p < .01, g = .48). Additionally, a one-way ANOVA reveals a positive effect of semester level on NOS views for the intervention group (p < .01; η² = .16) but not for the control groups. Conclusion: The findings support evidence suggesting that explicit approaches are effective when fostering an informed understanding of NOS. More specifically, a sequence of both versions of explicitly teaching NOS discussed in the literature seems to be a way to successfully promote pre-service teachers' NOS understanding.

  13. 76 FR 29277 - Exelon Generation Company, LLC; Peach Bottom Atomic Power Station Unit Nos. 2 and 3...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-20

    ... Company, LLC; Peach Bottom Atomic Power Station Unit Nos. 2 and 3; Environmental Assessment and Finding of..., LLC (Exelon, the licensee) for operation of the Peach Bottom Atomic Power Station, Units 2 and 3...) in the Peach Bottom Atomic Power Station (PBAPS) LLRW Storage Facility. Considering the nature of the...

  14. Posttranscriptional regulation of human iNOS by the NO/cGMP pathway.

    PubMed

    Pérez-Sala, D; Cernuda-Morollón, E; Díaz-Cazorla, M; Rodríguez-Pascual, F; Lamas, S

    2001-03-01

    Nitric oxide (NO) and cGMP may exert positive or negative effects on inducible NO synthase (iNOS) expression. We have explored the influence of the NO/cGMP pathway on iNOS levels in human mesangial cells. Inhibition of NOS activity during an 8-h stimulation with IL-1beta plus tumor necrosis factor (TNF)-alpha reduced iNOS levels, while NO donors amplified iNOS induction threefold. However, time-course studies revealed a subsequent inhibitory effect of NO donors on iNOS protein and mRNA levels. This suggests that NO may contribute both to iNOS induction and downregulation. Soluble guanylyl cyclase (sGC) activation may be involved in these effects. Inhibition of sGC attenuated IL-1beta/TNF-alpha-elicited iNOS induction and reduced NO-driven amplification. Interestingly, cGMP analogs also modulated iNOS protein and mRNA levels in a biphasic manner. Inhibition of transcription unveiled a negative posttranscriptional modulation of the iNOS transcript by NO and cGMP at late times of induction. Supplementation with 8-bromo-cGMP (8-BrcGMP) reduced iNOS mRNA stability by 50%. These observations evidence a complex feedback regulation of iNOS expression, in which posttranscriptional mechanisms may play an important role.

  15. Developing the Inner Scientist: Book Club Participation and the Nature of Science

    ERIC Educational Resources Information Center

    Griffard, Phyllis Baudoin; Mosleh, Tayseer; Kubba, Saad

    2013-01-01

    The leap from science student to scientist involves recognizing that science is a tentative, evolving body of knowledge that is socially constructed and culturally influenced; this is known as The Nature of Science (NOS). The aim of this study was to document NOS growth in first-year premedical students who participated in a science book club as a…

  16. Preservice and Inservice Science Teachers' Responses and Reasoning about the Nature of Science

    ERIC Educational Resources Information Center

    Buaraphan, Khajornsak

    2009-01-01

    An adequate understanding of the nature of science (NOS) is essential for science teachers. The Myths of Science Questionnaire (MOSQ) consisting of 14 items, which comprised both optional and written types of response, was utilized to explore 113 Thai preservice and 101 inservice science teachers' understanding and reasoning about the NOS,…

  17. Teaching about Nature of Science through Short Lab Activities in Hong Kong Classroom

    ERIC Educational Resources Information Center

    Lau, Kwok-chi

    2017-01-01

    The study evaluated the effectiveness of using short, school lab investigations to teach about the nature of science (NOS). A manipulated lab inquiry approach was used, which modified the investigations in ways that students were compelled to experience certain NOS aspects. An investigation about apple browning was used to teach about the…

  18. Challenges and Changes: Developing Teachers' and Initial Teacher Education Students' Understandings of the Nature of Science

    ERIC Educational Resources Information Center

    Ward, Gillian; Haigh, Mavis

    2017-01-01

    Teachers need an understanding of the nature of science (NOS) to enable them to incorporate NOS into their teaching of science. The current study examines the usefulness of a strategy for challenging or changing teachers' understandings of NOS. The teachers who participated in this study were 10 initial teacher education chemistry students and six…

  19. "Non alcoholic fatty liver disease and eNOS dysfunction in humans".

    PubMed

    Persico, Marcello; Masarone, Mario; Damato, Antonio; Ambrosio, Mariateresa; Federico, Alessandro; Rosato, Valerio; Bucci, Tommaso; Carrizzo, Albino; Vecchione, Carmine

    2017-03-07

    NAFLD is associated to Insulin Resistance (IR). IR is responsible for Endothelial Dysfunction (ED) through the impairment of eNOS function. Although eNOS derangement has been demonstrated in experimental models, no studies have directly shown that eNOS dysfunction is associated with NAFLD in humans. The aim of this study is to investigate eNOS function in NAFLD patients. Fifty-four NAFLD patients were consecutively enrolled. All patients underwent clinical and laboratory evaluation and liver biopsy. Patients were divided into two groups by the presence of NAFL or NASH. We measured vascular reactivity induced by patients' platelets on isolated mice aorta rings. Immunoblot assays for platelet-derived phosphorylated-eNOS (p-eNOS) and immunohistochemistry for hepatic p-eNOS have been performed to evaluate eNOS function in platelets and liver specimens. Flow-mediated-dilation (FMD) was also performed. Data were compared with healthy controls. Twenty-one (38, 8%) patients had NAFL and 33 (61, 7%) NASH. No differences were found between groups and controls except for HOMA and insulin (p < 0.0001). Vascular reactivity demonstrated a reduced function induced from NAFLD platelets as compared with controls (p < 0.001), associated with an impaired p-eNOS in both platelets and liver (p < 0.001). NAFL showed a higher impairment of eNOS phosphorylation in comparison to NASH (p < 0.01). In contrast with what observed in vitro, the vascular response by FMD was worse in NASH as compared with NAFL. Our data showed, for the first time in humans, that NAFLD patients show a marked eNOS dysfunction, which may contribute to a higher CV risk. eNOS dysfunction observed in platelets and liver tissue didn't match with FMD.

  20. iNOS expression in CD4+ T cells limits Treg induction by repressing TGFβ1: combined iNOS inhibition and Treg depletion unmask endogenous antitumor immunity.

    PubMed

    Jayaraman, Padmini; Alfarano, Matthew G; Svider, Peter F; Parikh, Falguni; Lu, Geming; Kidwai, Sarah; Xiong, Huabao; Sikora, Andrew G

    2014-12-15

    Expression of inducible nitric oxide synthase (iNOS) in different cellular compartments may have divergent effects on immune function. We used a syngeneic tumor model to functionally characterize the role of iNOS in regulation of CD4(+)FOXP3(+) regulatory T cells (Treg), and optimize the beneficial effects of iNOS inhibition on antitumor immunity. Wild-type (WT) or iNOS knockout mice bearing established MT-RET-1 melanoma were treated with the small-molecule iNOS inhibitor L-NIL and/or cyclophosphamide alone or in combination. The effect of iNOS inhibition or knockout on induction of Treg from mouse and human CD4(+) T cells in ex vivo culture was determined in parallel in the presence or absence of TGFβ1-depleting antibodies, and TGFβ1 levels were assessed by ELISA. Whereas intratumoral myeloid-derived suppressor cells (MDSC) were suppressed by iNOS inhibition or knockout, systemic and intratumoral FOXP3(+) Treg levels increased in tumor-bearing mice. iNOS inhibition or knockout similarly enhanced induction of Treg from activated cultured mouse splenocytes or purified human or mouse CD4(+) T cells in a TGFβ1-dependent manner. Although either iNOS inhibition or Treg depletion with low-dose cyclophosphamide alone had little effect on growth of established MT-RET1 melanoma, combination treatment potently inhibited MDSC and Treg, boosted tumor-infiltrating CD8(+) T-cell levels, and arrested tumor growth in an immune-dependent fashion. iNOS expression in CD4(+) T cells suppresses Treg induction by inhibiting TGFβ1 production. Our data suggest that iNOS expression has divergent effects on induction of myeloid and lymphoid-derived regulatory populations, and strongly support development of combinatorial treatment approaches that target these populations simultaneously. ©2014 American Association for Cancer Research.

  1. The Nature of Science Instrument-Elementary (NOSI-E): the end of the road?

    PubMed

    Peoples, Shelagh M; O'Dwyer, Laura M

    2014-01-01

    This research continues prior work published in this journal (Peoples, O'Dwyer, Shields and Wang, 2013). The first paper described the scale development, psychometric analyses and part-validation of a theoretically-grounded Rasch-based instrument, the Nature of Science Instrument-Elementary (NOSI-E). The NOSI-E was designed to measure elementary students' understanding of the Nature of Science (NOS). In the first paper, evidence was provided for three of the six validity aspects (content, substantive and generalizability) needed to support the construct validity of the NOSI-E. The research described in this paper examines two additional validity aspects (structural and external). The purpose of this study was to determine which of three competing internal models provides reliable, interpretable, and responsive measures of students' understanding of NOS. One postulate is that the NOS construct is unidimensional;. alternatively, the NOS construct is composed of five independent unidimensional constructs (the consecutive approach). Lastly, the NOS construct is multidimensional and composed of five inter-related but separate dimensions. The vast body of evidence supported the claim that the NOS construct is multidimensional. Measures from the multidimensional model were positively related to student science achievement and students' perceptions of their classroom environment; this provided supporting evidence for the external validity aspect of the NOS construct. As US science education moves toward students learning science through engaging in authentic scientific practices and building learning progressions (NRC, 2012), it will be important to assess whether this new approach to teaching science is effective, and the NOSI-E may be used as a measure of the impact of this reform.

  2. Pretreatment with β-Boswellic Acid Improves Blood Stasis Induced Endothelial Dysfunction: Role of eNOS Activation

    PubMed Central

    Wang, Mingming; Chen, Minchun; Ding, Yi; Zhu, Zhihui; Zhang, Yikai; Wei, Peifeng; Wang, Jingwen; Qiao, Yi; Li, Liang; Li, Yuwen; Wen, Aidong

    2015-01-01

    Vascular endothelial cells play an important role in modulating anti-thrombus and maintaining the natural function of vascular by secreting many active substances. β-boswellic acid (β-BA) is an active triterpenoid compound from the extract of boswellia serrate. In this study, it is demonstrated that β-BA ameliorates plasma coagulation parameters, protects endothelium from blood stasis induced injury and prevents blood stasis induced impairment of endothelium-dependent vasodilatation. Moreover, it is found that β-BA significantly increases nitric oxide (NO) and cyclic guanosine 3’, 5’-monophosphate (cGMP) levels in carotid aortas of blood stasis rats. To stimulate blood stasis-like conditions in vitro, human umbilical vein endothelial cells (HUVECs) were exposed to transient oxygen and glucose deprivation (OGD). Treatment of β-BA significantly increased intracellular NO level. Western blot and immunofluorescence as well as immunohistochemistry reveal that β-BA increases phosphorylation of enzyme nitric oxide synthase (eNOS) at Ser1177. In addition, β-BA mediated endothelium-dependent vasodilatation can be markedly blocked by eNOS inhibitor L-NAME in blood stasis rats. In OGD treated HUEVCs, the protective effect of β-BA is attenuated by knockdown of eNOS. In conclusion, the above findings provide convincing evidence for the protective effects of β-BA on blood stasis induced endothelial dysfunction by eNOS signaling pathway. PMID:26482008

  3. Teaching Nature of Science to K-2 Students: What Understandings Can They Attain?

    ERIC Educational Resources Information Center

    Akerson, Valarie; Donnelly, Lisa A.

    2010-01-01

    This study explored the influence of a Saturday Science program that used explicit reflective instruction through contextualized and decontextualized guided and authentic inquiry on K-2 students' views of nature of science (NOS). The six-week program ran for 2.5 hours weekly and emphasized NOS in a variety of science content areas, culminating in…

  4. The Context of Demarcation in Nature of Science Teaching: The Case of Astrology

    ERIC Educational Resources Information Center

    Turgut, Halil

    2011-01-01

    The aim of developing students' understanding of the nature of science [NOS] has been considered an important aspect of science education. However, the results of previous research indicate that students of various ages and even teachers possess both inaccurate and inappropriate views of the NOS. Such a failure has been explained by the view that…

  5. Analysis of Five Junior High School Physics Textbooks Used in China for Representations of Nature of Science

    NASA Astrophysics Data System (ADS)

    Li, Xiying; Tan, Zuyu; Shen, Jiliang; Hu, Weiping; Chen, Yinghe; Wang, Jingying

    2018-04-01

    Based on the analytical framework of nature of science (NOS) in junior school science textbooks, a content analysis method was adopted to analyze the NOS in junior middle school physical textbooks (grade 8) of five editions authorized by the Ministry of Education of China, and the features of NOS were analyzed and compared. It was found that all five textbooks presented poor representations of NOS. None of these five editions were scientifically objective, nor did they include discussions of scientific laws and theories. Furthermore, they rarely presented empirical evidence to support their arguments. The explicit representations of NOS were particularly inadequate.

  6. PPARα induced NOS1 phosphorylation via PI3K/Akt in guinea pig antral mucous cells: NO-enhancement in Ca(2+)-regulated exocytosis.

    PubMed

    Tanaka, Saori; Hosogi, Shigekuni; Sawabe, Yukinori; Shimamoto, Chikao; Matsumura, Hitoshi; Inui, Toshio; Marunaka, Yoshinori; Nakahari, Takashi

    2016-01-01

    A PPARα (peroxisome proliferation activation receptor α) agonist (GW7647) activates nitric oxide synthase 1 (NOS1) to produce NO leading to cGMP accumulation in antral mucous cells. In this study, we examined how PPARα activates NOS1. The NO production stimulated by GW7647 was suppressed by inhibitors of PI3K (wortmannin) and Akt (AKT 1/2 Kinase Inhibitor, AKT-inh), although it was also suppressed by the inhibitors of PPARα (GW6471) and NOS1 (N-PLA). GW7647 enhanced the ACh (acetylcholine)-stimulated exocytosis (Ca(2+)-regulated exocytosis) mediated via NO, which was abolished by GW6471, N-PLA, wortmannin, and AKT-inh. The Western blotting revealed that GW7647 phosphorylates NOS1 via phosphorylation of PI3K/Akt in antral mucous cells. The immunofluorescence examinations demonstrated that PPARα existing with NOS1 co-localizes with PI3K and Akt in the cytoplasm of antral mucous cells. ACh alone and AACOCF3, an analogue of arachidonic acid (AA), induced the NOS1 phosphorylation via PI3K/Akt to produce NO, which was inhibited by GW6471. Since AA is a natural ligand for PPARα, ACh stimulates PPARα probably via AA. In conclusion, PPARα activates NOS1 via PI3K/Akt phosphorylation to produce NO in antral mucous cells during ACh stimulation.

  7. English Secondary Students' Thinking about the Status of Scientific Theories: Consistent, Comprehensive, Coherent and Extensively Evidenced Explanations of Aspects of the Natural World--Or Just "An Idea Someone Has"

    ERIC Educational Resources Information Center

    Taber, Keith S.; Billingsley, Berry; Riga, Fran; Newdick, Helen

    2015-01-01

    Teaching about the nature of science (NOS) is seen as a priority for science education in many national contexts. The present paper focuses on one central issue in learning about NOS: understanding the nature and status of scientific theories. A key challenge in teaching about NOS is to persuade students that scientific knowledge is generally…

  8. The relationship between nature of science understandings and science self-efficacy beliefs of sixth grade students

    NASA Astrophysics Data System (ADS)

    Parker, Elisabeth Allyn

    Bandura (1986) posited that self-efficacy beliefs help determine what individuals do with the knowledge and skills they have and are critical determinants of how well skill and knowledge are acquired. Research has correlated self-efficacy beliefs with academic success and subject interest (Pajares, Britner, & Valiante, 2000). Similar studies report a decreasing interest by students in school science beginning in middle school claiming that they don't enjoy science because the classes are boring and irrelevant to their lives (Basu & Barton, 2007). The hypothesis put forth by researchers is that students need to observe models of how science is done, the nature of science (NOS), so that they connect with the human enterprise of science and thereby raise their self-efficacy (Britner, 2008). This study examined NOS understandings and science self-efficacy of students enrolled in a sixth grade earth science class taught with explicit NOS instruction. The research questions that guided this study were (a) how do students' self-efficacy beliefs change as compared with changes in their nature of science understandings?; and (b) how do changes in students' science self-efficacy beliefs vary with gender and ethnicity segregation? A mixed method design was employed following an embedded experimental model (Creswell & Plano Clark, 2007). As the treatment, five NOS aspects were first taught by the teachers using nonintegrated activities followed by integrated instructional approach (Khishfe, 2008). Students' views of NOS using the Views on Nature of Science (VNOS) (Lederman, Abd-El-Khalick, & Schwartz, 2002) along with their self-efficacy beliefs using three Likert-type science self-efficacy scales (Britner, 2002) were gathered. Changes in NOS understandings were determined by categorizing student responses and then comparing pre- and post-instructional understandings. To determine changes in participants' self-efficacy beliefs as measured by the three subscales, a multivariate

  9. Representing Nature of Science in a Science Textbook: Exploring Author-Editor-Publisher Interactions

    ERIC Educational Resources Information Center

    DiGiuseppe, Maurice

    2014-01-01

    Current reforms in elementary and secondary science education call for students and teachers to develop more informed views of the nature of science (NOS)--a process in which science textbooks play a significant role. This paper reports on a case study of the development of representations of the NOS in a senior high school chemistry textbook by…

  10. Effects of cyclooxygenase inhibitor pretreatment on nitric oxide production, nNOS and iNOS expression in rat cerebellum.

    PubMed

    Di Girolamo, G; Farina, M; Riberio, M L; Ogando, D; Aisemberg, J; de los Santos, A R; Martí, M L; Franchi, A M

    2003-07-01

    1. The therapeutic effect of nonsteroidal anti-inflammatory drugs (NSAIDs) is thought to be due mainly to its inhibition of cyclooxygenase (COX) enzymes, but there is a growing body of research that now demonstrates a variety of NSAIDs effects on cellular signal transduction pathways other than those involving prostaglandins. 2. Nitric oxide (NO) as a free radical and an agent that gives rise to highly toxic oxidants (peroxynitrile, nitric dioxide, nitron ion), becomes a cause of neuronal damage and death in some brain lesions such as Parkinson and Alzheimer disease, and Huntington's chorea. 3. In the present study, the in vivo effect of three NSAIDs (lysine clonixinate (LC), indomethacine (INDO) and meloxicam (MELO)) on NO production and nitric oxide synthase expression in rat cerebellar slices was analysed. Rats were treated with (a) saline, (b) lipopolysaccharide (LPS) (5 mg kg(-1), i.p.), (c) saline in combination with different doses of NSAIDs and (d) LPS in combination with different doses of NSAIDs and then killed 6 h after treatment. 4. NO synthesis, evaluated by Bred and Snyder technique, was increased by LPS. This augmentation was inhibited by coadministration of the three NSAIDs assayed. None of the NSAIDs tested was able to modify control NO synthesis. 5. Expression of iNOS and neural NOS (nNOS) was detected by Western blotting in control and LPS-treated rats. LC and INDO, but not MELO, were able to inhibit the expression of these enzymes. 6. Therefore, reduction of iNOS and nNOS levels in cerebellum may explain, in part, the anti-inflammatory effect of these NSAIDs and may also have importance in the prevention of NO-mediated neuronal injury.

  11. Effects of cyclooxygenase inhibitor pretreatment on nitric oxide production, nNOS and iNOS expression in rat cerebellum

    PubMed Central

    DiGirolamo, G; Farina, M; Riberio, M L; Ogando, D; Aisemberg, J; de los Santos, A R; Martí, M L; Franchi, A M

    2003-01-01

    The therapeutic effect of nonsteroidal anti-inflammatory drugs (NSAIDs) is thought to be due mainly to its inhibition of cyclooxygenase (COX) enzymes, but there is a growing body of research that now demonstrates a variety of NSAIDs effects on cellular signal transduction pathways other than those involving prostaglandins. Nitric oxide (NO) as a free radical and an agent that gives rise to highly toxic oxidants (peroxynitrile, nitric dioxide, nitron ion), becomes a cause of neuronal damage and death in some brain lesions such as Parkinson and Alzheimer disease, and Huntington's chorea. In the present study, the in vivo effect of three NSAIDs (lysine clonixinate (LC), indomethacine (INDO) and meloxicam (MELO)) on NO production and nitric oxide synthase expression in rat cerebellar slices was analysed. Rats were treated with (a) saline, (b) lipopolysaccharide (LPS) (5 mg kg−1, i.p.), (c) saline in combination with different doses of NSAIDs and (d) LPS in combination with different doses of NSAIDs and then killed 6 h after treatment. NO synthesis, evaluated by Bred and Snyder technique, was increased by LPS. This augmentation was inhibited by coadministration of the three NSAIDs assayed. None of the NSAIDs tested was able to modify control NO synthesis. Expression of iNOS and neural NOS (nNOS) was detected by Western blotting in control and LPS-treated rats. LC and INDO, but not MELO, were able to inhibit the expression of these enzymes. Therefore, reduction of iNOS and nNOS levels in cerebellum may explain, in part, the anti-inflammatory effect of these NSAIDs and may also have importance in the prevention of NO-mediated neuronal injury. PMID:12871835

  12. Contextualization of Nature of Science within the Socioscientific Issues Framework: A Review of Research

    ERIC Educational Resources Information Center

    Karisan, Dilek; Zeidler, Dana L.

    2017-01-01

    The aim of this paper is to examine the importance of contextualization of Nature of Science (NOS) within the Socioscientific Issues (SSI) framework, because of the importance to science education. The emphasis on advancing scientific literacy is contingent upon a robust understanding and appreciation of NOS, as well as the acquisition of…

  13. Osthole relaxes pulmonary arteries through endothelial phosphatidylinositol 3-kinase/Akt-eNOS-NO signaling pathway in rats.

    PubMed

    Yao, Li; Lu, Ping; Li, Yumei; Yang, Lijing; Feng, Hongxuan; Huang, Yong; Zhang, Dandan; Chen, Jianguo; Zhu, Daling

    2013-01-15

    Pulmonary arterial hypertension is a life-threatening disease lacking effective therapies. Osthole is a natural coumarin compound isolated from Angelica pubescens Maxim., which possesses hypotensive effect. Although its effects on isolated thoracic aorta (systemic circulating system) are clarified, it remains unclear whether Osthole relaxes isolated pulmonary arteries (PAs) (pulmonary circulating system). The aim of this study was to investigate the effects of Osthole on isolated PAs and the underlying mechanisms. We examined PA relaxation induced by Osthole in isolated human and rat PA rings with force-electricity transducers, the expression and activity of endothelial nitric oxide synthase (eNOS) and protein kinase B (Akt) with western blot, and nitric oxide (NO) production using DAF-FM DA fluorescent indicator. The results showed that Osthole elicited a dose-dependent vasorelaxation activity with phenylephrine-precontracted human and rat PA rings, which can be diminished by endothelium denudation and inhibition of eNOS, while having no effect on rat mesenteric arteries. Osthole increased NO release as well as activation of Akt and eNOS, indicated with increased phosphorylations of Akt at Ser-473 and eNOS at Ser-1177 in endothelial cells. PI3K inhibitor LY294002 also blocked Osthole induced vasodilation. In summary, dilative effect of Osthole was dependent on endothelial integrity and NO production, and was mediated by endothelial PI3K/Akt-eNOS-NO pathway. These may provide a new pulmonary vasodilator for the therapy of pulmonary arterial hypertension. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. The Impact of a Course on Nature of Science Pedagogical Views and Rationales: Comparing Preservice Teachers in Their First versus Second Experience

    ERIC Educational Resources Information Center

    Kruse, Jerrid W.; Easter, Jaclyn M.; Edgerly, Hallie S.; Seebach, Colin; Patel, Neal

    2017-01-01

    This study explored changes in preservice teachers' (PSTs) nature of science pedagogical (NOSP) views and nature of science (NOS) rationales using pre- and post-course written responses as well as interview data. Through systematic analysis, themes were generated and compared to the NOS literature. Comparisons between pre- and post-course data…

  15. NOS3 gene polymorphisms and exercise hemodynamics in postmenopausal women.

    PubMed

    Hand, B D; McCole, S D; Brown, M D; Park, J J; Ferrell, R E; Huberty, A; Douglass, L W; Hagberg, J M

    2006-12-01

    We tested whether the G894T and T-786C NOS3 polymorphisms were associated with exercise cardiovascular (CV) hemodynamics in sedentary, physically active, and endurance-trained postmenopausal women. CV hemodynamic parameters including heart rate (HR), systolic (SBP) and diastolic (DBP) blood pressures and cardiac output (Q), as determined by acetylene rebreathing, stroke volume (SV), arteriovenous oxygen difference (a-vO2 diff), and total peripheral resistance (TPR) were measured during submaximal (40, 60, 80 %) and maximal (approximately 100 % VO2max) exercise. NOS3 G894T genotype was not significantly associated, either independently or interactively with habitual physical activity (PA) level, with SBP, Q, TPR, or a-vO2 diff during submaximal or maximal exercise. However, NOS3 894T non-carriers had a higher submaximal exercise HR than NOS3 894T allele carriers (120 +/- 2 vs. 112 +/- 2 beats/min, p = 0.007). NOS3 894T allele carriers had a higher SV than 894T non-carriers (78 +/- 2 vs. 72 +/- 2 ml/beat, p = 0.03) during submaximal exercise. NOS3 894T non-carriers also had a higher maximal exercise HR averaged across habitual PA groups than T allele carrier women (165 +/- 2 vs. 158 +/- 2 beats/min, p = 0.04). NOS3 894T allele carriers also tended to have a higher SV during maximal exercise than 894T non-carriers (70 +/- 2 vs. 64 +/- 2 ml/beat, p = 0.08). NOS3 T-786C genotype was not significantly associated, either independently or interactively, with any of the CV hemodynamic measures during submaximal or maximal exercise. These results suggest an association of NOS3 G894T genotype with submaximal and maximal exercise CV hemodynamic responses, especially HR, in postmenopausal women.

  16. Thai and Bangladeshi In-Service Science Teachers' Conceptions of Nature of Science: A Comparative Study

    ERIC Educational Resources Information Center

    Buaraphan, Khajornsak; Abedin Forhad, Ziaul

    2014-01-01

    Understanding of nature of science (NOS) serves as one of the desirable characteristics of science teachers. The current study explored 55 Thai and 110 Bangladeshi in-service secondary science teachers' conceptions of NOS regarding scientific knowledge, scientific method, scientists' work, and scientific enterprise, by using the Myths of Science…

  17. Evaluating Instrument Quality in Science Education: Rasch-Based Analyses of a Nature of Science Test

    ERIC Educational Resources Information Center

    Neumann, Irene; Neumann, Knut; Nehm, Ross

    2011-01-01

    Given the central importance of the Nature of Science (NOS) and Scientific Inquiry (SI) in national and international science standards and science learning, empirical support for the theoretical delineation of these constructs is of considerable significance. Furthermore, tests of the effects of varying magnitudes of NOS knowledge on…

  18. Changing Preservice Science Teachers' Views of Nature of Science: Why Some Conceptions May Be More Easily Altered than Others

    ERIC Educational Resources Information Center

    Mesci, Gunkut; Schwartz, Renee' S.

    2017-01-01

    The purpose of this study was to assess preservice teachers' views of Nature of Science (NOS), identify aspects that were challenging for conceptual change, and explore reasons why. This study particularly focused on why and how some concepts of NOS may be more easily altered than others. Fourteen preservice science teachers enrolled in a NOS and…

  19. Explicit Nature of Science and Argumentation Instruction in the Context of Socioscientific Issues: An Effect on Student Learning and Transfer

    ERIC Educational Resources Information Center

    Khishfe, Rola

    2014-01-01

    The purpose of the study was two-fold: to (a) investigate the influence of explicit nature of science (NOS) and explicit argumentation instruction in the context of a socioscientific issue on the argumentation skills and NOS understandings of students, and (b) explore the transfer of students' NOS understandings and argumentation skills learned in…

  20. Using Nonfiction Narratives in an English Course to Teach the Nature of Science and Its Importance to Communicating About Science †

    PubMed Central

    Aune, Jeanine Elise; Evans, Lynn Lundy; Boury, Nancy

    2018-01-01

    The nature of science (NOS) is a foundational framework for understanding scientific ideas and concepts. This framework includes scientific methodology, the process of revising and interpreting data, and the ways in which science is a social endeavor. Nature of science literature treats science as a way of knowing that is based on observable phenomenon. While discipline-specific coursework teaches the factual information of science, it may fall short on teaching scientific literacy, a key component of which is understanding NOS. We have designed an English course that features nonfiction narratives describing the early days of epidemiology, hygiene awareness, and the current controversy surrounding vaccination. Using a validated assessment of student understanding of NOS, the Student Understanding of Science and Scientific Inquiry (SUSSI), we have determined that this science-themed English composition course was effective in teaching NOS. Student understanding of NOS increased between the beginning and the end of the course in eight of the nine parameters of NOS measured, with the greatest gains in understanding the role of revision and of creativity in science. Our data imply that the course helped students develop a slightly less naïve understanding of the nature of science and its importance in the development and dissemination of scientific ideas and concepts. PMID:29904539

  1. The protein inhibitor of nNOS (PIN/DLC1/LC8) binding does not inhibit the NADPH-dependent heme reduction in nNOS, a key step in NO synthesis

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Parhad, Swapnil S.; Jaiswal, Deepa; TIFR Centre for Interdisciplinary Sciences, 21 Brundavan Colony, Narsingi, Hyderabad 500075

    The neuronal nitric oxide synthase (nNOS) is an essential enzyme involved in the synthesis of nitric oxide (NO), a potent neurotransmitter. Although previous studies have indicated that the dynein light chain 1 (DLC1) binding to nNOS could inhibit the NO synthesis, the claim is challenged by contradicting reports. Thus, the mechanism of nNOS regulation remained unclear. nNOS has a heme-bearing, Cytochrome P450 core, and the functional enzyme is a dimer. The electron flow from NADPH to Flavin, and finally to the heme of the paired nNOS subunit within a dimer, is facilitated upon calmodulin (CaM) binding. Here, we show thatmore » DLC1 binding to nNOS-CaM complex does not affect the electron transport from the reductase to the oxygenase domain. Therefore, it cannot inhibit the rate of NADPH-dependent heme reduction in nNOS, which results in L-Arginine oxidation. Also, the NO release activity does not decrease with increasing DLC1 concentration in the reaction mix, which further confirmed that DLC1 does not inhibit nNOS activity. These findings suggest that the DLC1 binding may have other implications for the nNOS function in the cell. - Highlights: • The effect of interaction of nNOS with DLC1 has been debatable with contradicting reports in literature. • Purified DLC1 has no effect on electron transport between reductase and oxygenase domain of purified nNOS-CaM. • The NO release activity of nNOS was not altered by DLC1, supporting that DLC1 does not inhibit the enzyme. • These findings suggest that the DLC1 binding may have other implications for the nNOS function in the cell.« less

  2. iNOS inhibits hair regeneration in obese diabetic (ob/ob) mice.

    PubMed

    Sasaki, Mari; Shinozaki, Shohei; Morinaga, Hironobu; Kaneki, Masao; Nishimura, Emi; Shimokado, Kentaro

    2018-07-02

    Previous studies have shown that androgenic alopecia is associated with metabolic syndrome and diabetes. However, the detailed mechanism whereby diabetes causes alopecia still remains unclear. We focused on the inflammatory response that is caused by diabetes or obesity, given that inflammation is a risk factor for hair loss. Inducible nitric oxide synthase (iNOS) is known to be upregulated under conditions of acute or chronic inflammation. To clarify the potential role of iNOS in diabetes-related alopecia, we generated obese diabetic iNOS-deficient (ob/ob; iNOS-KO mice). We observed that ob/ob; iNOS-KO mice were potentiated for the transition from telogen (rest phase) to anagen (growth phase) in the hair cycle compared with iNOS-proficient ob/ob mice. To determine the effect of nitric oxide (NO) on the hair cycle, we administered an iNOS inhibitor intraperitoneally (compound 1400 W, 10 mg/kg) or topically (10% aminoguanidine) in ob/ob mice. We observed that iNOS inhibitors promoted anagen transition in ob/ob mice. Next, we administered an NO donor (S-nitrosoglutathione, GSNO), to test whether NO has the telogen elongation effects. The NO donor was sufficient to induce telogen elongation in wild-type mice. Together, our data indicate that iNOS-derived NO plays a role in telogen elongation under the inflammatory conditions associated with diabetes in mice. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

  3. Analysis of Nature of Science Included in Recent Popular Writing Using Text Mining Techniques

    ERIC Educational Resources Information Center

    Jiang, Feng; McComas, William F.

    2014-01-01

    This study examined the inclusion of nature of science (NOS) in popular science writing to determine whether it could serve supplementary resource for teaching NOS and to evaluate the accuracy of text mining and classification as a viable research tool in science education research. Four groups of documents published from 2001 to 2010 were…

  4. Henry David Thoreau, Forest Succession & The Nature of Science: A Method for Curriculum Development

    ERIC Educational Resources Information Center

    Howe, Eric M.

    2009-01-01

    A main reason for using the history of science in classroom instruction is its utility in promoting students' understanding of the nature of science (NOS). As indicated in such documents as the "National Science Education Standards," it is important to help students develop their understanding of NOS so that they will become more critical…

  5. The Nature of Science and the Next Generation Science Standards: Analysis and Critique

    NASA Astrophysics Data System (ADS)

    McComas, William F.; Nouri, Noushin

    2016-08-01

    This paper provides a detailed analysis of the inclusion of aspects of nature of science (NOS) in the Next Generation Science Standards (NGSS). In this new standards document, NOS elements in eight categories are discussed in Appendix H along with illustrative statements (called exemplars). Many, but not all, of these exemplars are linked to the standards by their association with either the "practices of science" or "crosscutting concepts," but curiously not with the recommendations for science content. The study investigated all aspects of NOS in NGSS including the accuracy and inclusion of the supporting exemplar statements and the relationship of NOS in NGSS to other aspects of NOS to support teaching and learning science. We found that while 92 % of these exemplars are acceptable, only 78 % of those written actually appear with the standards. "Science as a way of knowing" is a recommended NOS category in NGSS but is not included with the standards. Also, several other NOS elements fail to be included at all grade levels thus limiting their impact. Finally, NGSS fails to include or insufficiently emphasize several frequently recommended NOS elements such as creativity and subjectivity. The paper concludes with a list of concerns and solutions to the challenges of NOS in NGSS.

  6. The Role of Informal Support Networks in Teaching the Nature of Science

    NASA Astrophysics Data System (ADS)

    Herman, Benjamin C.; Olson, Joanne K.; Clough, Michael P.

    2017-06-01

    This study reports the participation of 13 secondary science teachers in informal support networks and how that participation was associated with their nature of science (NOS) teaching practices 2 to 5 years after having graduated from the same science teacher education program. The nine teachers who participated in informal support networks taught the NOS at high/medium levels, while the four non-participating teachers taught the NOS at low levels. The nine high/medium NOS implementation teachers credited the informal support networks for maintaining/heightening their sense of responsibility for teaching NOS and for helping them navigate institutional constraints that impede effective NOS instruction. Several high/medium NOS instruction implementers initially struggled to autonomously frame and resolve the complexities experienced in schools and thus drew from the support networks to engage in more sophisticated forms of teacher decision-making. In contrast, the NOS pedagogical decisions of the four teachers not participating in support networks were governed primarily by the expectations and constraints experienced in their schools. Implications of this study include the need for reconsidering the structure of teacher mentorship programs to ensure they do not promote archaic science teaching practices that are at odds with reform efforts in science education.

  7. The Effectiveness of Conceptual Change Texts and Concept Clipboards in Learning the Nature of Science

    ERIC Educational Resources Information Center

    Çil, Emine; Çepni, Salih

    2016-01-01

    Background: One of the most important goals of science education is to enable students to understand the nature of science (NOS). However, generally regular science teaching in classrooms does not help students improve informed NOS views. Purpose: This study investigated the influence of an explicit reflective conceptual change approach compared…

  8. Developing a Professional Identity as an Elementary Teacher of Nature of Science: A Self-Study of Becoming an Elementary Teacher

    ERIC Educational Resources Information Center

    Akerson, Valarie L.; Pongsanon, Khemmawadee; Weiland, Ingrid S.; Nargund-Joshi, Vanashri

    2014-01-01

    This study explores the development of professional identity as a teacher of nature of science (NOS). Our research question was "How can a teacher develop a professional identity as an elementary teacher of NOS?" Through a researcher log, videotaped lessons, and collection of student work, we were able to track efforts in teaching NOS as…

  9. Making Learning Last: Teachers' Long-Term Retention of Improved Nature of Science Conceptions and Instructional Rationales

    ERIC Educational Resources Information Center

    Mulvey, Bridget K.; Bell, Randy L.

    2017-01-01

    Despite successful attempts to improve learners' nature of science (NOS) conceptions through explicit, reflective approaches, retention of improved conceptions is rarely addressed in research. The issue of context for NOS instruction has implications for this retention. Whether to contextualise has been the question occupying science educators'…

  10. Relationship between students' understandings of nature of science and instructional context

    NASA Astrophysics Data System (ADS)

    Khishfe, Rola Fouad

    The study investigated and compared two different instructional approaches (integrated and nonintegrated), which address the explicit teaching of nature of science (NOS), in relation to improving students' understanding of NOS. Participants were three teachers and their students---a total of 129---which comprised six groups of 89 ninth and 40 10th/11th graders. Each teacher taught two intact sections of the same grade level within a specific science discipline (environmental science, chemistry, or biology). The treatment for all groups spanned five to six weeks and involved teaching a unit, which included both the regular science content and NOS. Participants in each of the two intact classes were taught by the same teacher about their regular science content, with the difference being the context in which NOS was explicitly taught (integrated or nonintegrated). In the integrated group, NOS instruction was related to the science content addressed in the unit. In the nonintegrated group, NOS was taught through a set of generic (non content-embedded) activities that specifically addressed NOS aspects and were "interspersed" across the science content addressed in the unit. An open-ended questionnaire, in conjunction with semi-structured interviews, was used to assess participants' views prior to and following instruction. Data analysis involved a systematic process consistent with analytic induction. Results showed general improvements in participants' views of NOS regardless of whether or not NOS was integrated within the regular science content. The results of this study do not support the appealing assumption held by many science educators that integrating NOS within the context of the science content would better enhance the learning of NOS. However, the results suggest the possibility of an interaction between the type of change (naive to transitional, transitional to informed, naive to informed, no changes, regression) in students' views and the explicit

  11. Nature of Science and Decision-Making

    NASA Astrophysics Data System (ADS)

    Khishfe, Rola

    2012-01-01

    The study investigated the relationship of nature of science (NOS) instruction and students' decision-making (DM) related to a controversial socioscientific issue about genetically modified food. Participants were ninth-grade students in four intact sections (two regulars and two honors) in a public high school in the Midwest. All four groups were taught by their regular science teacher. The treatment comprised a four-week unit about genetic engineering. Two groups (one regular and one honors), referred to as comparison groups, received instruction in genetic engineering and how to formulate arguments and make decisions related to this controversial issue. The other two groups (one regular and one honors), referred to as treatment groups, received instruction in genetic engineering and how to apply NOS aspects as they formulate arguments and make decisions in relation to this controversial issue. Chi-square analyses showed significant differences between the comparison and the treatment groups in relation to the understandings of four NOS aspects. There were no differences in their decisions, but there were differences in their DM factors in the context of the controversial socioscientific issue about genetically modified food. These results are discussed in light of the relationship between students' understandings of NOS and their DM related to controversial socioscientific issues.

  12. Nature of Science and Decision-Making

    ERIC Educational Resources Information Center

    Khishfe, Rola

    2012-01-01

    The study investigated the relationship of nature of science (NOS) instruction and students' decision-making (DM) related to a controversial socioscientific issue about genetically modified food. Participants were ninth-grade students in four intact sections (two regulars and two honors) in a public high school in the Midwest. All four groups were…

  13. Students' Conceptions of the Nature of Science: Perspectives from Canadian and Korean Middle School Students

    ERIC Educational Resources Information Center

    Park, Hyeran; Nielsen, Wendy; Woodruff, Earl

    2014-01-01

    This study examined and compared students' understanding of nature of science (NOS) with 521 Grade 8 Canadian and Korean students using a mixed methods approach. The concepts of NOS were measured using a survey that had both quantitative and qualitative elements. Descriptive statistics and one-way multivariate analysis of variances examined the…

  14. Representations of Nature of Science in High School Chemistry Textbooks over the Past Four Decades

    ERIC Educational Resources Information Center

    Abd-El-Khalick, Fouad; Waters, Mindy; Le, An-Phong

    2008-01-01

    This study assessed the representations of nature of science (NOS) in high school chemistry textbooks and the extent to which these representations have changed during the past four decades. Analyses focused on the empirical, tentative, inferential, creative, theory-driven, and social NOS, in addition to the myth of "The Scientific Method," the…

  15. Representing Nature of Science in a Science Textbook: Exploring author-editor-publisher interactions

    NASA Astrophysics Data System (ADS)

    DiGiuseppe, Maurice

    2014-05-01

    Current reforms in elementary and secondary science education call for students and teachers to develop more informed views of the nature of science (NOS)-a process in which science textbooks play a significant role. This paper reports on a case study of the development of representations of the NOS in a senior high school chemistry textbook by the book's author, editor, and publisher. The study examines the multiple discourses that arose as the developers reflected on their personal and shared understandings of NOS; squared these with mandated curricula, the educational needs of chemistry students and teachers, and the exigencies of large-scale commercial textbook publishing. As a result, the team developed and incorporated, in the textbook, representations of NOS they believed were the most pedagogically suitable. Analysis of the data in this study indicates that a number of factors significantly influenced the development of representations of NOS, including representational accuracy (the degree to which representations of NOS conformed to informed views of the NOS), representational consistency (the degree to which representations of NOS in different parts of the book conveyed the same meaning), representational appropriateness (the age-, grade-, and reading-level appropriateness of the NOS representations), representational alignment (the degree to which NOS representations aligned with mandated curriculum), representational marketability (the degree to which NOS representations would affect sales of the textbook), and 'Workplace Resources' factors including availability of time, relevant expertise, and opportunities for professional development.

  16. The Impact of the Social Norms of Education on Beginning Science Teachers' Understanding of NOS During their First Three Years in the Classroom

    NASA Astrophysics Data System (ADS)

    Firestone, Jonah B.

    An understanding of the Nature of Science (NOS) remains a fundamental goal of science education in the Unites States. A developed understanding of NOS provides a framework in which to situate science knowledge. Secondary science teachers play a critical role in providing students with an introduction to understanding NOS. Unfortunately, due to the high turnover rates of secondary science teachers in the United States, this critical role is often filled by relatively novice teachers. These beginning secondary science teachers make instructional decisions regarding science that are drawn from their emerging knowledge base, including a tentative understanding of NOS. This tentative knowledge can be affected by environment and culture of the classroom, school, and district in which beginning teachers find themselves. When examining NOS among preservice and beginning teachers the background and demographics of the teachers are often ignored. These teachers are treated as a homogenous block in terms of their initial understanding of NOS. This oversight potentially ignores interactions that may happen over time as teachers cross the border from college students, preservice teachers, and scientists into the classroom environment. Through Symbolic Interactionism we can explain how teachers change in order to adapt to their new surroundings and how this adaptation may be detrimental to their understanding of NOS and ultimately to their practice. 63 teachers drawn from a larger National Science Foundation (NSF) funded study were interviewed about their understanding of NOS over three years. Several demographic factors including college major, preservice program, number of History and Philosophy of Science classes, and highest academic degree achieve were shown to have an affect on the understanding of NOS over time. In addition, over time, the teachers tended to 'converge' in their understanding of NOS regardless of preservice experiences or induction support. Both the affect

  17. Cross-Cultural Comparisons of Undergraduate Student Views of the Nature of Science

    NASA Astrophysics Data System (ADS)

    Arino de la Rubia, Leigh S.; Lin, Tzung-Jin; Tsai, Chin-Chung

    2014-07-01

    Past studies investigating university level students' views of nature of science (NOS) were relatively few and most of them were conducted in Western countries. This paper focuses upon comparing the quantitative patterns in Western (US Caucasian and African-American) and non-Western (Taiwanese) students' views of NOS (VNOS) by adopting a survey instrument. This analysis combined with qualitative data begin to uncover details of potential cultural differences in patterns specifically in the US educational context by comparing Caucasian and African-American student responses to a question from a commonly used assessment of VNOS. Results show different patterns of views along the four dimensions of NOS (social negotiation, invented/creative NOS, cultural impacts, and changing/tentative feature of science) according to student major, student gender, and student ethnicity. These differences and similarities have the potential to impact undergraduate education and underrepresentation of cultural minorities in science careers and call for further research into NOS views in the context of diverse student groups.

  18. Brain stem NOS and ROS in neural mechanisms of hypertension.

    PubMed

    Chan, Samuel H H; Chan, Julie Y H

    2014-01-01

    There is now compelling evidence to substantiate the notion that by depressing baroreflex regulation of blood pressure and augmenting central sympathetic outflow through their actions on the nucleus tractus solitarii (NTS) and rostral ventrolateral medulla (RVLM), brain stem nitric oxide synthase (NOS) and reactive oxygen species (ROS) are important contributing factors to neural mechanisms of hypertension. This review summarizes our contemporary views on the impact of NOS and ROS in the NTS and RVLM on neurogenic hypertension, and presents potential antihypertensive strategies that target brain stem NOS/ROS signaling. NO signaling in the brain stem may be pro- or antihypertensive depending on the NOS isoform that generates this gaseous moiety and the site of action. Elevation of the ROS level when its production overbalances its degradation in the NTS and RVLM underlies neurogenic hypertension. Interventional strategies with emphases on alleviating the adverse actions of these molecules on blood pressure regulation have been investigated. The pathological roles of NOS in the RVLM and NTS in neural mechanisms of hypertension are highly complex. Likewise, multiple signaling pathways underlie the deleterious roles of brain-stem ROS in neurogenic hypertension. There are recent indications that interactions between brain stem ROS and NOS may play a contributory role. Given the complicity of action mechanisms of brain-stem NOS and ROS in neural mechanisms of hypertension, additional studies are needed to identify the most crucial therapeutic target that is applicable not only in animal models but also in patients suffering from neurogenic hypertension.

  19. Testing primary-school children's understanding of the nature of science.

    PubMed

    Koerber, Susanne; Osterhaus, Christopher; Sodian, Beate

    2015-03-01

    Understanding the nature of science (NOS) is a critical aspect of scientific reasoning, yet few studies have investigated its developmental beginnings and initial structure. One contributing reason is the lack of an adequate instrument. Two studies assessed NOS understanding among third graders using a multiple-select (MS) paper-and-pencil test. Study 1 investigated the validity of the MS test by presenting the items to 68 third graders (9-year-olds) and subsequently interviewing them on their underlying NOS conception of the items. All items were significantly related between formats, indicating that the test was valid. Study 2 applied the same instrument to a larger sample of 243 third graders, and their performance was compared to a multiple-choice (MC) version of the test. Although the MC format inflated the guessing probability, there was a significant relation between the two formats. In summary, the MS format was a valid method revealing third graders' NOS understanding, thereby representing an economical test instrument. A latent class analysis identified three groups of children with expertise in qualitatively different aspects of NOS, suggesting that there is not a single common starting point for the development of NOS understanding; instead, multiple developmental pathways may exist. © 2014 The British Psychological Society.

  20. Nature of Science Instruction to Turkish Prospective Chemistry Teachers: The Effect of Explicit-Reflective Approach

    ERIC Educational Resources Information Center

    Aglarci, Oya; Sariçayir, Hakan; Sahin, Musa

    2016-01-01

    The purpose of this study is to investigate the effect of explicit-reflective nature of science (NOS) instruction on Turkish prospective chemistry teachers' (PCTs) views of NOS. In the research, case study as a qualitative design was used and PCTs' views were examined thoroughly. The participants of the study consisted of 22 senior PCTs. Data…

  1. Asiatic acid alleviates hemodynamic and metabolic alterations via restoring eNOS/iNOS expression, oxidative stress, and inflammation in diet-induced metabolic syndrome rats.

    PubMed

    Pakdeechote, Poungrat; Bunbupha, Sarawoot; Kukongviriyapan, Upa; Prachaney, Parichat; Khrisanapant, Wilaiwan; Kukongviriyapan, Veerapol

    2014-01-16

    Asiatic acid is a triterpenoid isolated from Centella asiatica. The present study aimed to investigate whether asiatic acid could lessen the metabolic, cardiovascular complications in rats with metabolic syndrome (MS) induced by a high-carbohydrate, high-fat (HCHF) diet. Male Sprague-Dawley rats were fed with HCHF diet with 15% fructose in drinking water for 12 weeks to induce MS. MS rats were treated with asiatic acid (10 or 20 mg/kg/day) or vehicle for a further three weeks. MS rats had an impairment of oral glucose tolerance, increases in fasting blood glucose, serum insulin, total cholesterol, triglycerides, mean arterial blood pressure, heart rate, and hindlimb vascular resistance; these were related to the augmentation of vascular superoxide anion production, plasma malondialdehyde and tumor necrosis factor-alpha (TNF-α) levels (p<0.05). Plasma nitrate and nitrite (NOx) were markedly high with upregulation of inducible nitric oxide synthase (iNOS) expression, but dowregulation of endothelial nitric oxide synthase (eNOS) expression (p<0.05). Asiatic acid significantly improved insulin sensitivity, lipid profiles, hemodynamic parameters, oxidative stress markers, plasma TNF-α, NOx, and recovered abnormality of eNOS/iNOS expressions in MS rats (p<0.05). In conclusion, asiatic acid improved metabolic, hemodynamic abnormalities in MS rats that could be associated with its antioxidant, anti-inflammatory effects and recovering regulation of eNOS/iNOS expression.

  2. The relationship between biology teachers' understanding of the nature of science and the understanding and acceptance of the theory of evolution

    NASA Astrophysics Data System (ADS)

    Cofré, Hernán; Cuevas, Emilia; Becerra, Beatriz

    2017-11-01

    Despite the importance of the theory of evolution (TE) to scientific knowledge, a number of misconceptions continue to be found among biology teachers. In this context, the first objective of this study was to identify the impact of professional development programme (PDP) on teachers' understanding of nature of science (NOS) and evolution and on the acceptance of this theory. Its second objective was to study the relationship among these variables. Three instruments were used to quantify these variables: the Views of the Nature of Science Version D (VNOS D+), the Assessing Contextual Reasoning about Natural Selection (ACORN), and the Measure of Acceptance of Theory of Evolution (MATE). The results indicate that the PDP had a positive impact on teachers, significantly improving their understanding of the NOS and natural selection, as well as their acceptance of the TE. Furthermore, a positive correlation between the understanding of the NOS obtained by teachers in the first part of the PDP and the understanding and acceptance of evolution that these teachers showed at the end of the programme was determined. However, no relationship between an understanding of the NOS and gains in the understanding and acceptance of evolution was found.

  3. Expression analysis of NOS family and HSP genes during thermal stress in goat ( Capra hircus)

    NASA Astrophysics Data System (ADS)

    Yadav, Vijay Pratap; Dangi, Satyaveer Singh; Chouhan, Vikrant Singh; Gupta, Mahesh; Dangi, Saroj K.; Singh, Gyanendra; Maurya, Vijay Prakash; Kumar, Puneet; Sarkar, Mihir

    2016-03-01

    Approximately 50 genes other than heat shock protein (HSP) expression changes during thermal stress. These genes like nitric oxide synthase (NOS) need proper attention and investigation to find out their possible role in the adaptation to thermal stress in animals. So, the present study was undertaken to demonstrate the expressions of inducible form type II NOS (iNOS), endothelial type III NOS (eNOS), constitutively expressed enzyme NOS (cNOS), HSP70, and HSP90 in peripheral blood mononuclear cells (PBMCs) during different seasons in Barbari goats. Real-time polymerase chain reaction, western blot, and immunocytochemistry were applied to investigate messenger RNA (mRNA) expression, protein expression, and immunolocalization of examined factors. The mRNA and protein expressions of iNOS, eNOS, cNOS, HSP70, and HSP90 were significantly higher ( P < 0.05) during peak summer, and iNOS and eNOS expressions were also observed to be significantly higher ( P < 0.05) during peak winter season as compared with moderate season. The iNOS, eNOS, cNOS, HSP70, and HSP90 were mainly localized in plasma membrane and cytoplasm of PBMCs. To conclude, data generated in the present study indicate the possible involvement of the NOS family genes in amelioration of thermal stress so as to maintain cellular integrity and homeostasis in goats.

  4. A Look into Students' Retention of Acquired Nature of Science Understandings

    NASA Astrophysics Data System (ADS)

    Khishfe, Rola

    2015-07-01

    Having the learning and retention of science content and skills as a goal of scientific literacy, it is significant to study the issue of retention as it relates to teaching and learning about nature of science (NOS). Then, the purpose of this study was to investigate the development of NOS understandings of students, and the retention of these understandings four months after being acquired through explicit reflective instruction in relation to two contexts. Participants were 24 tenth-grade students at a private high school in a city in the Middle East. Explicit NOS instruction was addressed within a six-week unit about genetic engineering. Three NOS aspects were integrated and dispersed across the unit. A questionnaire, together with semi-structured interviews, was administered as pre-, post-, and delayed post-test to assess the retention of participants' NOS understandings. The questionnaire had two open-ended scenarios addressing controversial socioscientific issues about genetically modified food and water fluoridation. Results showed that most students improved their naïve understandings of NOS in relation to the two contexts following the six-week unit with the explicit NOS instruction. However, these newly acquired NOS understandings were not retained by all students four months after instruction. Many of the students reverted back to their earlier naïve understandings. Conclusions about the factors facilitating the process of retention as the orientation to meaningful learning and the prolonged exposure to the domain were discussed in relation to practical implications in the classroom.

  5. Influence of coronary artery diameter on eNOS protein content

    NASA Technical Reports Server (NTRS)

    Laughlin, M. H.; Turk, J. R.; Schrage, W. G.; Woodman, C. R.; Price, E. M.

    2003-01-01

    The purpose of this study was to test the hypothesis that the content of endothelial nitric oxide synthase (eNOS) protein (eNOS protein/g total artery protein) increases with decreasing artery diameter in the coronary arterial tree. Content of eNOS protein was determined in porcine coronary arteries with immunoblot analysis. Arteries were isolated in six size categories from each heart: large arteries [301- to 2,500-microm internal diameter (ID)], small arteries (201- to 300-microm ID), resistance arteries (151- to 200-microm ID), large arterioles (101- to 150-microm ID), intermediate arterioles (51- to 100-microm ID), and small arterioles(<50-microm ID). To obtain sufficient protein for analysis from small- and intermediate-sized arterioles, five to seven arterioles 1-2 mm in length were pooled into one sample for each animal. Results establish that the number of smooth muscle cells per endothelial cell decreases from a number of 10 to 15 in large coronary arteries to 1 in the smallest arterioles. Immunohistochemistry revealed that eNOS is located only in endothelial cells in all sizes of coronary artery and in coronary capillaries. Contrary to our hypothesis, eNOS protein content did not increase with decreasing size of coronary artery. Indeed, the smallest coronary arterioles had less eNOS protein per gram of total protein than the large coronary arteries. These results indicate that eNOS protein content is greater in the endothelial cells of conduit arteries, resistance arteries, and large arterioles than in small coronary arterioles.

  6. How In-Service Science Teachers Integrate History and Nature of Science in Elementary Science Courses

    ERIC Educational Resources Information Center

    Hacieminoglu, Esme

    2014-01-01

    The purpose of this study is to investigate how the in-service science teachers' (IST) perceptions and practices about curriculum and integration of the history of science (HOS) and the nature of science (NOS) affect their science courses. For this aim, how ISTs integrated the NOS and HOS in their elementary science courses for understanding of…

  7. Outcomes of Nature of Science Instruction along a Context Continuum: Preservice Secondary Science Teachers' Conceptions and Instructional Intentions

    ERIC Educational Resources Information Center

    Bell, Randy L.; Mulvey, Bridget K.; Maeng, Jennifer L.

    2016-01-01

    This investigation examined outcomes associated with nature of science (NOS) instruction along a science-content context continuum on the development of secondary preservice science teachers' conceptions of and plans to teach NOS, moving beyond the common dichotomy of contextualized versus noncontextualized instruction. Participants comprised six…

  8. Expression profiles of eNOS, iNOS and microRNA-27b in the corpus cavernosum of rats submitted to chronic alcoholism and Diabetes mellitus.

    PubMed

    Cunha, Joao Paulo da; Lizarte, Fermino Sanches; Novais, Paulo Cezar; Gattas, Daniela; Carvalho, Camila Albuquerque Mello de; Tirapelli, Daniela Pretti da Cunha; Molina, Carlos Augusto Fernandes; Tirapelli, Luis Fernando; Tucci, Silvio

    2017-01-01

    To evaluate the expression of endothelial and inducible NOS in addition to the miRNA-27b in the corpus cavernosum and peripheral blood of healthy rats, diabetic rats, alcoholic rats and rats with both pathologies. Forty eight Wistar rats were divided into four groups: control (C), alcoholic (A), diabetic (D) and alcoholic-diabetic (AD). Samples of the corpus cavernosum were prepared to study protein expressions of eNOS and iNOS by immunohistochemistry and expression of miRNA-27b in the corpus cavernosum and peripheral blood. Immunohistochemistry for eNOS and iNOS showed an increase in cavernosal smooth muscle cells in the alcoholic, diabetic and alcoholic-diabetic groups when compared with the control group. Similarly, the mRNA levels for eNOS were increased in cavernosal smooth muscle (CSM) in the alcoholic, diabetic and alcoholic-diabetic groups and miRNA-27b were decreased in CSM in the alcoholic, diabetic and alcoholic-diabetic groups. The major new finding of our study was an impairment of relaxation of cavernosal smooth muscle in alcoholic, diabetic, and alcoholic-diabetic rats that involved a decrease in the nitric oxide pathway by endothelium-dependent mechanisms accompanied by a change in the corpus cavernosum contractile sensitivity.

  9. Teaching With and About Nature of Science, and Science Teacher Knowledge Domains

    NASA Astrophysics Data System (ADS)

    Abd-El-Khalick, Fouad

    2013-09-01

    The ubiquitous goals of helping precollege students develop informed conceptions of nature of science (NOS) and experience inquiry learning environments that progressively approximate authentic scientific practice have been long-standing and central aims of science education reforms around the globe. However, the realization of these goals continues to elude the science education community partly because of a persistent, albeit not empirically supported, coupling of the two goals in the form of `teaching about NOS with inquiry'. In this context, the present paper aims, first, to introduce the notions of, and articulate the distinction between, teaching with and about NOS, which will allow for the meaningful coupling of the two desired goals. Second, the paper aims to explicate science teachers' knowledge domains requisite for effective teaching with and about NOS. The paper argues that research and development efforts dedicated to helping science teachers develop deep, robust, and integrated NOS understandings would have the dual benefits of not only enabling teachers to convey to students images of science and scientific practice that are commensurate with historical, philosophical, sociological, and psychological scholarship (teaching about NOS), but also to structure robust inquiry learning environments that approximate authentic scientific practice, and implement effective pedagogical approaches that share a lot of the characteristics of best science teaching practices (teaching with NOS).

  10. Stromal cell-derived factor 2 is critical for Hsp90-dependent eNOS activation.

    PubMed

    Siragusa, Mauro; Fröhlich, Florian; Park, Eon Joo; Schleicher, Michael; Walther, Tobias C; Sessa, William C

    2015-08-18

    Endothelial nitric oxide synthase (eNOS) catalyzes the conversion of l-arginine and molecular oxygen into l-citrulline and nitric oxide (NO), a gaseous second messenger that influences cardiovascular physiology and disease. Several mechanisms regulate eNOS activity and function, including phosphorylation at Ser and Thr residues and protein-protein interactions. Combining a tandem affinity purification approach and mass spectrometry, we identified stromal cell-derived factor 2 (SDF2) as a component of the eNOS macromolecular complex in endothelial cells. SDF2 knockdown impaired agonist-stimulated NO synthesis and decreased the phosphorylation of eNOS at Ser(1177), a key event required for maximal activation of eNOS. Conversely, SDF2 overexpression dose-dependently increased NO synthesis through a mechanism involving Akt and calcium (induced with ionomycin), which increased the phosphorylation of Ser(1177) in eNOS. NO synthesis by iNOS (inducible NOS) and nNOS (neuronal NOS) was also enhanced upon SDF2 overexpression. We found that SDF2 was a client protein of the chaperone protein Hsp90, interacting preferentially with the M domain of Hsp90, which is the same domain that binds to eNOS. In endothelial cells exposed to vascular endothelial growth factor (VEGF), SDF2 was required for the binding of Hsp90 and calmodulin to eNOS, resulting in eNOS phosphorylation and activation. Thus, our data describe a function for SDF2 as a component of the Hsp90-eNOS complex that is critical for signal transduction in endothelial cells. Copyright © 2015, American Association for the Advancement of Science.

  11. Stromal cell–derived factor 2 is critical for Hsp90-dependent eNOS activation

    PubMed Central

    Siragusa, Mauro; Fröhlich, Florian; Park, Eon Joo; Schleicher, Michael; Walther, Tobias C.; Sessa, William C.

    2016-01-01

    Endothelial nitric oxide synthase (eNOS) catalyzes the conversion of l-arginine and molecular oxygen into l-citrulline and nitric oxide (NO), a gaseous second messenger that influences cardiovascular physiology and disease. Several mechanisms regulate eNOS activity and function, including phosphorylation at Ser and Thr residues and protein-protein interactions. Combining a tandem affinity purification approach and mass spectrometry, we identified stromal cell–derived factor 2 (SDF2) as a component of the eNOS macromolecular complex in endothelial cells. SDF2 knockdown impaired agonist-stimulated NO synthesis and decreased the phosphorylation of eNOS at Ser1177, a key event required for maximal activation of eNOS. Conversely, SDF2 overexpression dose-dependently increased NO synthesis through a mechanism involving Akt and calcium (induced with ionomycin), which increased the phosphorylation of Ser1177 in eNOS. NO synthesis by iNOS (inducible NOS) and nNOS (neuronal NOS) was also enhanced upon SDF2 overexpression. We found that SDF2 was a client protein of the chaperone protein Hsp90, interacting preferentially with the M domain of Hsp90, which is the same domain that binds to eNOS. In endothelial cells exposed to vascular endothelial growth factor (VEGF), SDF2 was required for the binding of Hsp90 and calmodulin to eNOS, resulting in eNOS phosphorylation and activation. Thus, our data describe a function for SDF2 as a component of the Hsp90-eNOS complex that is critical for signal transduction in endothelial cells. PMID:26286023

  12. Learning Nature of Science Concepts through a Research Apprenticeship Program: A Comparative Study of Three Approaches

    ERIC Educational Resources Information Center

    Burgin, Stephen R.; Sadler, Troy D.

    2016-01-01

    The merits of three approaches (explicit, reflective and implicit) to Nature of Science (NOS) teaching and learning in the context of a summer research experience on high school student participants' NOS ideas were explored in this study. The effectiveness of explicit over implicit approaches has been demonstrated in school contexts, but less…

  13. Professional Development of Elementary and Science Teachers in a Summer Science Camp: Changing Nature of Science Conceptions

    ERIC Educational Resources Information Center

    Karaman, Ayhan

    2016-01-01

    Many countries all over the world have recently integrated nature of science (NOS) concepts into their science education standards. Providing professional support to teachers about NOS concepts is crucially important for successful implementation of the standards. For this purpose, a summer science camp was offered to elementary and science…

  14. Scientific Communication and the Nature of Science

    ERIC Educational Resources Information Center

    Nielsen, Kristian H.

    2013-01-01

    Communication is an important part of scientific practice and, arguably, may be seen as constitutive to scientific knowledge. Yet, often scientific communication gets cursory treatment in science studies as well as in science education. In Nature of Science (NOS), for example, communication is rarely mentioned explicitly, even though, as will be…

  15. Understanding the Nature of Science through Evolution

    ERIC Educational Resources Information Center

    Narguizian, Paul

    2004-01-01

    As the common thread in biology, the topic of evolution and its related historical development can help students make sense of diverse biological concepts. The discussion of evolution provides educators with something else--a significant opportunity to teach important lessons involving the nature of science (NOS). This article addresses strategies…

  16. Closing the Gap between Beliefs and Practice: Change of Pre-Service Chemistry Teachers' Orientations during a PCK-Based NOS Course

    ERIC Educational Resources Information Center

    Demirdögen, Betül; Uzuntiryaki-Kondakçi, Esen

    2016-01-01

    The purpose of this case study was to investigate how pre-service chemistry teachers' science teaching orientations change during a two-semester intervention designed to enhance their pedagogical content knowledge (PCK) for teaching the nature of science (NOS). Moreover, the way that pre-service chemistry teachers translated their change in…

  17. 15 CFR Supplement Nos. 2-3 to Part... - [Reserved

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 15 Commerce and Foreign Trade 2 2011-01-01 2011-01-01 false [Reserved] Nos. Supplement Nos. 2-3 to Part 716 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS INITIAL...

  18. 15 CFR Supplement Nos. 2-3 to Part... - [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 2 2010-01-01 2010-01-01 false [Reserved] Nos. Supplement Nos. 2-3 to Part 716 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS INITIAL...

  19. How the nature of science is presented to elementary students in science read-alouds

    NASA Astrophysics Data System (ADS)

    Rivera, Seema

    Students as early as elementary school age are capable of learning the aspects of the nature of science (NOS), and the National Benchmarks incorporate the NOS as part of the learning objectives for K--2 students. Learning more about elementary science instruction can aid in understanding how the NOS can be taught or potentially integrated into current teaching methods. Although many teaching methods exist, this study will focus on read-alouds because they are recommended for and are very common in elementary schools. The read-aloud practice is particularly helpful to young students because most of these students have a higher listening comprehension than reading comprehension. One of the main components of the read-aloud practice is the discourse that takes place about the trade book. Both explicit and implicit messages are communicated to students by teachers' language and discussion that takes place in the classroom. Therefore, six multisite naturalistic case studies were conducted to understand elementary teachers' understanding of the NOS, students' understandings of the NOS, trade book representations of the NOS, and read-aloud practices and understandings in upstate New York. The findings of the study revealed that teachers and students held mostly naive and mixed understandings of the NOS. The trade books that had explicit connections to the NOS helped teachers discuss NOS related issues, even when the teachers did not hold strong NOS views. Teachers who held more informed NOS views were able to ask students NOS related questions. All teachers showed they need guidance on how to translate their NOS views into discussion and see the significance of the NOS in their classroom. Explicit NOS instruction can improve student understanding of the NOS, however the focus should be not only on teachers and their NOS understanding but also on the books used. These results show that quality trade books with explicit connections to the NOS are a useful instructional tool

  20. Changing Preservice Science Teachers' Views of Nature of Science: Why Some Conceptions May be More Easily Altered than Others

    NASA Astrophysics Data System (ADS)

    Mesci, Gunkut; Schwartz, Renee'S.

    2017-04-01

    The purpose of this study was to assess preservice teachers' views of Nature of Science (NOS), identify aspects that were challenging for conceptual change, and explore reasons why. This study particularly focused on why and how some concepts of NOS may be more easily altered than others. Fourteen preservice science teachers enrolled in a NOS and Science Inquiry course participated in this study. Data were collected by using a pre/post format with the Views of Nature of Science questionnaire (VNOS-270), the Views of Scientific Inquiry questionnaire (VOSI-270), follow-up interviews, and classroom artifacts. The results indicated that most students initially held naïve views about certain aspects of NOS like tentativeness and subjectivity. By the end of the semester, almost all students dramatically improved their understanding about almost all aspects of NOS. However, several students still struggled with certain aspects like the differences between scientific theory and law, tentativeness, and socio-cultural embeddedness. Results suggested that instructional, motivational, and socio-cultural factors may influence if and how students changed their views about targeted NOS aspects. Students thought that classroom activities, discussions, and readings were most helpful to improve their views about NOS. The findings from the research have the potential to translate as practical advice for teachers, science educators, and future researchers.

  1. Daily cycling of nitric oxide synthase (NOS) in the hippocampus of pigeons (C. livia)

    PubMed Central

    2013-01-01

    Background Nitric oxide synthase (NOS) is essential for the synthesis of nitric oxide (NO), a non-conventional neurotransmitter with an important role in synaptic plasticity underlying processes of hippocampus-dependent memory and in the regulation of biological clocks and circadian rhythms. Many studies have shown that both the NOS cytosolic protein content and its enzymatic activity present a circadian variation in different regions of the rodent brain, including the hippocampus. The present study investigated the daily variation of NOS enzymatic activity and the cytosolic content of nNOS in the hippocampus of pigeons. Results Adult pigeons kept under a skeleton photoperiod were assigned to six different groups. Homogenates of the hippocampus obtained at six different times-of-day were used for NOS analyses. Both iNOS activity and nNOS cytosolic protein concentrations were highest during the subjective light phase and lowest in the subjective dark phase of the circadian period. ANOVA showed significant time differences for iNOS enzymatic activity (p < 0.05) and for nNOS protein content (p < 0.05) in the hippocampus. A significant daily rhythm for both iNOS and nNOS was confirmed by analysis with the Cosinor method (p < 0.05). The present findings indicate that the enzymatic activity of iNOS and content of nNOS protein in the hippocampus of pigeons exhibit a daily rhythm, with acrophase values occurring during the behavioral activity phase. Conclusions The data corroborate the reports on circadian variation of NOS in the mammalian hippocampus and can be considered indicative of a dynamic interaction between hippocampus-dependent processes and circadian clock mechanisms. PMID:24176048

  2. Awakening the Scientist Inside: Global Climate Change and the Nature of Science in an Elementary Science Methods Course

    ERIC Educational Resources Information Center

    Matkins, Juanita Jo; Bell, Randy L.

    2007-01-01

    This investigation assessed the impact of situating explicit nature of science (NOS) instruction within the issues surrounding global climate change and global warming (GCC/GW). Participants in the study were 15 preservice elementary teachers enrolled in a science methods course. The instructional intervention included explicit NOS instruction…

  3. Understandings of Nature of Science and Multiple Perspective Evaluation of Science News by Non-Science Majors

    ERIC Educational Resources Information Center

    Leung, Jessica Shuk Ching; Wong, Alice Siu Ling; Yung, Benny Hin Wai

    2015-01-01

    Understandings of nature of science (NOS) are a core component of scientific literacy, and a scientifically literate populace is expected to be able to critically evaluate science in the media. While evidence has remained inconclusive on whether better NOS understandings will lead to critical evaluation of science in the media, this study aimed at…

  4. The Effect of Explicit-Reflective and Historical Approach on Preservice Elementary Teachers' Views of Nature of Science

    ERIC Educational Resources Information Center

    Pekbay, Canay; Yilmaz, Serkan

    2015-01-01

    This study aims to explore the influence of nature of science (NOS) activities based on explicit-reflective and historical approach on preservice elementary teachers' views of NOS aspects. Mixed-method approach including both qualitative and quantitative methods was used. The sample consisted of 83 preservice elementary teachers of a public…

  5. Transfer of Nature of Science Understandings into Similar Contexts: Promises and Possibilities of an Explicit Reflective Approach

    ERIC Educational Resources Information Center

    Khishfe, Rola

    2013-01-01

    The purpose of this study was to (a) investigate the effectiveness of explicit nature of science (NOS) instruction in the context of controversial socioscientific issues and (b) explore whether the transfer of acquired NOS understandings, which were explicitly taught in the context of one socioscientific context, into other similar contexts…

  6. Using Video Vignettes of Historical Episodes for Promoting Pre-Service Teachers' Ideas about the Nature of Science

    ERIC Educational Resources Information Center

    Cakmakci, Gultekin

    2017-01-01

    This study used video vignettes of historical episodes from documentary films as a context and instructional tool to promote pre-service science teachers' (PSTs) conceptions of the nature of science (NOS). The participants received explicit-reflective NOS instruction, and were introduced to techniques to be able to use scenes from documentary…

  7. A Community College Instructor's Reflective Journey toward Developing Pedagogical Content Knowledge for Nature of Science in a Non-Majors Undergraduate Biology Course

    ERIC Educational Resources Information Center

    Krajewski, Sarah J.; Schwartz, Renee

    2014-01-01

    Research supports an explicit-reflective approach to teaching about nature of science (NOS), but little is reported on teachers' journeys as they attempt to integrate NOS into everyday lessons. This participatory action research paper reports the challenges and successes encountered by an in-service teacher, Sarah, implementing NOS for the…

  8. 12. Railing Detail for Dam Nos. 3 and 4, Fence ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. Railing Detail for Dam Nos. 3 and 4, Fence Detail for Reservoir Nos. 3 and 4, Single Lamp Details, Triple Lamp Details - Washington Park Reservoirs, 2403 SW Jefferson Street, Portland, Multnomah County, OR

  9. Face and Emotion Recognition in MCDD versus PDD-NOS

    ERIC Educational Resources Information Center

    Herba, Catherine M.; de Bruin, Esther; Althaus, Monika; Verheij, Fop; Ferdinand, Robert F.

    2008-01-01

    Previous studies indicate that Multiple Complex Developmental Disorder (MCDD) children differ from PDD-NOS and autistic children on a symptom level and on psychophysiological functioning. Children with MCDD (n = 21) and PDD-NOS (n = 62) were compared on two facets of social-cognitive functioning: identification of neutral faces and facial…

  10. Impact of Chinese Culture on Pre-service Science Teachers' Views of the Nature of Science

    NASA Astrophysics Data System (ADS)

    Wan, Dongsheng; Zhang, Hongshia; Wei, Bing

    2018-04-01

    This study examines Chinese pre-service teachers' (N = 30) views on the nature of science (NOS) and how Chinese culture influences their views. Participants were from two teachers' universities in eastern China. As an exploratory and interpretive study, a scenario-based interview approach was adopted. The results indicated that the participants held unique views about the five key aspects of NOS. Many participants have alternative and contemporary views of NOS, but few possess classical views. In fact, teachers adopted features of the Confucian Doctrine of the Mean either consciously or unconsciously to account for their views of NOS. This research reflects that the Doctrine of the Mean affected Chinese teachers' views of NOS, making them rather deficient in their understandings of classical NOS. Based on empirical data, it is argued that science teacher training in China should focus on the content and objectives of classical NOS, rather than just teaching contemporary views of NOS. Taking Chinese culture into consideration, science teacher education in China cannot entirely import the strategies of teaching the classical views of NOS from the developed world, but should develop, design and contextualize local strategies that are suitable for the training of Chinese science teachers. Some issues for further investigation of learners' views of NOS in non-Western contexts are suggested as implications from this study.

  11. Social and Rational: The Presentation of Nature of Science and the Uptake of Change in Evolution Textbooks

    ERIC Educational Resources Information Center

    Fuselier, Linda C.; Jackson, J. Kasi; Stoiko, Rachel

    2016-01-01

    The nature of science (NOS) as described by education scholars is a critical component of scientific literacy and includes both rational and social aspects taught best in an explicit and reflective manner. NOS is frequently tied to a critical contextual empiricism (CCE) framework for knowledge production. Central to CCE is that objectivity is…

  12. Analysis of Nature of Science Included in Recent Popular Writing Using Text Mining Techniques

    NASA Astrophysics Data System (ADS)

    Jiang, Feng; McComas, William F.

    2014-09-01

    This study examined the inclusion of nature of science (NOS) in popular science writing to determine whether it could serve supplementary resource for teaching NOS and to evaluate the accuracy of text mining and classification as a viable research tool in science education research. Four groups of documents published from 2001 to 2010 were analyzed: Scientific American, Discover magazine, winners of the Royal Society Winton Prize for Science Books, and books from NSTA's list of Outstanding Science Trade Books. Computer analysis categorized passages in the selected documents based on their inclusions of NOS. Human analysis assessed the frequency, context, coverage, and accuracy of the inclusions of NOS within computer identified NOS passages. NOS was rarely addressed in selected document sets but somewhat more frequently addressed in the letters section of the two magazines. This result suggests that readers seem interested in the discussion of NOS-related themes. In the popular science books analyzed, NOS presentations were found more likely to be aggregated in the beginning and the end of the book, rather than scattered throughout. The most commonly addressed NOS elements in the analyzed documents are science and society and empiricism in science. Only one inaccurate presentation of NOS were identified in all analyzed documents. The text mining technique demonstrated exciting performance, which invites more applications of the technique to analyze other aspects of science textbooks, popular science writing, or other materials involved in science teaching and learning.

  13. Teaching and Assessing the Nature of Science

    ERIC Educational Resources Information Center

    Clough, Michael P.

    2011-01-01

    Understanding the nature of science (NOS)--what science is and how it works, the assumptions that underlie scientific knowledge, how scientists function as a social group, and how society impacts and reacts to science--is prominent in science education reform documents (Rutherford and Ahlgren 1990; AAAS 1993; McComas and Olson 1998; NRC 1996; AAAS…

  14. KLF6 and iNOS regulates apoptosis during respiratory syncytial virus infection

    PubMed Central

    Mgbemena, Victoria; Segovia, Jesus; Chang, Te-Hung; Bose, Santanu

    2013-01-01

    Human respiratory syncytial virus (RSV) is a highly pathogenic lung-tropic virus that causes severe respiratory diseases. Enzymatic activity of inducible nitric oxide (iNOS) is required for NO generation. Although NO contributes to exaggerated lung disease during RSV infection, the role of NO in apoptosis during infection is not known. In addition, host trans-activator(s) required for iNOS gene expression during RSV infection is unknown. In the current study we have uncovered the mechanism of iNOS gene induction by identifying kruppel-like factor 6 (KLF6) as a critical transcription factor required for iNOS gene expression during RSV infection. Furthermore, we have also uncovered the role of iNOS as a critical host factor regulating apoptosis during RSV infection. PMID:23831683

  15. Some Reflections on "Going beyond the Consensus View" of the Nature of Science in K-12 Science Education

    ERIC Educational Resources Information Center

    Berkovitz, Joseph

    2017-01-01

    Hodson and Wong (2017, this issue) argue that, though the nature of science (NOS) is now an established focus of school science education and a key element in defining scientific literacy, "the consensus view" of NOS misrepresents contemporary scientific practice. They then propose a number of alternative approaches to science curriculum…

  16. iNOS Activity Modulates Inflammation, Angiogenesis, and Tissue Fibrosis in Polyether-Polyurethane Synthetic Implants.

    PubMed

    Cassini-Vieira, Puebla; Araújo, Fernanda Assis; da Costa Dias, Filipi Leles; Russo, Remo Castro; Andrade, Silvia Passos; Teixeira, Mauro Martins; Barcelos, Luciola Silva

    2015-01-01

    There is considerable interest in implantation techniques and scaffolds for tissue engineering and, for safety and biocompatibility reasons, inflammation, angiogenesis, and fibrosis need to be determined. The contribution of inducible nitric oxide synthase (iNOS) in the regulation of the foreign body reaction induced by subcutaneous implantation of a synthetic matrix was never investigated. Here, we examined the role of iNOS in angiogenesis, inflammation, and collagen deposition induced by polyether-polyurethane synthetic implants, using mice with targeted disruption of the iNOS gene (iNOS(-/-)) and wild-type (WT) mice. The hemoglobin content and number of vessels were decreased in the implants of iNOS(-/-) mice compared to WT mice 14 days after implantation. VEGF levels were also reduced in the implants of iNOS(-/-) mice. In contrast, the iNOS(-/-) implants exhibited an increased neutrophil and macrophage infiltration. However, no alterations were observed in levels of CXCL1 and CCL2, chemokines related to neutrophil and macrophage migration, respectively. Furthermore, the implants of iNOS(-/-) mice showed boosted collagen deposition. These data suggest that iNOS activity controls inflammation, angiogenesis, and fibrogenesis in polyether-polyurethane synthetic implants and that lack of iNOS expression increases foreign body reaction to implants in mice.

  17. Crataegus Special Extract WS 1442 Effects on eNOS and microRNA 155.

    PubMed

    Wang, Xinwen; Liang, Yan; Shi, Jian; Zhu, Hao-Jie; Bleske, Barry E

    2018-04-16

    Increased expression of microRNA 155 (miR-155) results in a decrease in endothelial nitric oxide synthase (eNOS) expression and impaired endothelial function. Factors that have been shown to increase expression of miR-155 may be mitigated by WS 1442, an extract of hawthorn leaves and flowers ( Crataegus special extract) that contains a range of pharmacologically active substances including oligomeric proanthocyanidins and flavonoids. The purpose of this study is to determine the effect of WS 1442 on the expression of miR-155 and eNOS in the presence of tumor necrosis factor (TNF- α ). Human umbilical vein endothelial cells (HUVECs) were studied after the exposure to TNF- α , with or without simvastatin (positive control) and WS 1442. The expression levels of eNOS, phosphorylated eNOS, and miR-155 in the different HUVEC treatment groups were determined by western blot and quantitative real-time polymerase chain reaction, respectively. To evaluate the effect of WS 1442 on the eNOS activity, the medium and intracellular nitrate/nitrite (NO) concentrations were also analyzed using a colorimetric Griess assay kit. The results demonstrated that TNF- α upregulated miR-155 expression and decreased eNOS expression and NO concentrations. WS 1442 also increased miR-155 expression and decreased eNOS expression but, unlike TNF- α , increased phosphorylated eNOS expression and NO concentrations. Surprisingly, WS 1442 increased miR-155 expression; however, WS 1442 mitigated the overall negative effect of miR-155 on decreasing eNOS expression by increasing expression of phosphorylated eNOS and resulting in an increase in NO concentrations. In the setting where miR-155 may be expressed, WS 1442 may offer vascular protection by increasing the expression of phosphorylated eNOS. Georg Thieme Verlag KG Stuttgart · New York.

  18. Connecting Science and Mathematics: The Nature of Proof and Disproof in Science and Mathematics

    ERIC Educational Resources Information Center

    Oehrtman, Michael; Lawson, Anton E.

    2008-01-01

    Disagreements exist among textbook authors, curriculum developers, and even among science and mathematics educators/researchers regarding the meanings and roles of several key nature-of-science (NOS) and nature-of-mathematics (NOM) terms such as proof, disproof, hypotheses, predictions, theories, laws, conjectures, axioms, theorems, and…

  19. Awakening the Scientist Inside: Global Climate Change and the Nature of Science in an Elementary Science Methods Course

    NASA Astrophysics Data System (ADS)

    Matkins, Juanita Jo; Bell, Randy L.

    2007-04-01

    This investigation assessed the impact of situating explicit nature of science (NOS) instruction within the issues surrounding global climate change and global warming (GCC/GW). Participants in the study were 15 preservice elementary teachers enrolled in a science methods course. The instructional intervention included explicit NOS instruction combined with explicit GCC/GW instruction situated within the normal elementary science methods curriculum. Participants’ conceptions of NOS and GCC/GW were assessed with pre- and postadministrations of open-ended questionnaires and interviews. Results indicated that participants’ conceptions of NOS and GCC/GW improved over the course of the semester. Furthermore, participants were able to apply their conceptions to decision making about socioscientific issues. The results provide support for context-based NOS instruction in an elementary science methods course.

  20. Learning the 'grammar of science': The influence of a physical science content course on teachers' understanding of the nature of science

    NASA Astrophysics Data System (ADS)

    Hanuscin, Deborah L.

    This research examined the development of practicing K--8 teachers' views of the nature of science (NOS) within a physical science content course. Reforms in science education have called for the teaching of science as inquiry. In order to achieve the vision of the reforms, teachers must understand science, both a body of knowledge and as a process, but also the very nature of science itself-or the values and assumptions inherent in the construction of scientific knowledge. NOS has been deemed a critical component of scientific literacy, with implications for making informed decisions about scientific claims. Research has indicated that despite the emphasis of reforms, teachers generally do not possess accurate views of NOS. Recent work in science education has led to the recommendation that efforts undertaken within teacher education programs to improve teachers' understanding of NOS can be enhanced through relevant coursework in other academic areas, including the sciences. The purpose of this dissertation was to provide an empirical basis for this recommendation, by examining the development of teachers' views of NOS within a physical science content course. To this end, the researcher employed qualitative methodology including participant observation, interview, document analysis, and questionnaire to assess teacher participants' views of the nature of science and the impact of their experience in the content course on these views. As a result of this research, implications for both the course design and science teacher education have been described. In addition, various aspects of the community of practice that characterizes the classroom that inhibit the development of understandings about the nature of science are identified. It is argued that instruction in NOS should be approached from the perspective that builds bridges between the communities of practice of learners and of scientists.

  1. Partial eNOS deficiency causes spontaneous thrombotic cerebral infarction, amyloid angiopathy and cognitive impairment.

    PubMed

    Tan, Xing-Lin; Xue, Yue-Qiang; Ma, Tao; Wang, Xiaofang; Li, Jing Jing; Lan, Lubin; Malik, Kafait U; McDonald, Michael P; Dopico, Alejandro M; Liao, Francesca-Fang

    2015-06-24

    Cerebral infarction due to thrombosis leads to the most common type of stroke and a likely cause of age-related cognitive decline and dementia. Endothelial nitric oxide synthase (eNOS) generates NO, which plays a crucial role in maintaining vascular function and exerting an antithrombotic action. Reduced eNOS expression and eNOS polymorphisms have been associated with stroke and Alzheimer's disease (AD), the most common type of dementia associated with neurovascular dysfunction. However, direct proof of such association is lacking. Since there are no reports of complete eNOS deficiency in humans, we used heterozygous eNOS(+/-) mice to mimic partial deficiency of eNOS, and determine its impact on cerebrovascular pathology and perfusion of cerebral vessels. Combining cerebral angiography with immunohistochemistry, we found thrombotic cerebral infarctions in eNOS(+/-) mice as early as 3-6 months of age but not in eNOS(+/+) mice at any age. Remarkably, vascular occlusions in eNOS(+/-) mice were found almost exclusively in three areas: temporoparietal and retrosplenial granular cortexes, and hippocampus this distribution precisely matching the hypoperfused areas identified in preclinical AD patients. Moreover, progressive cerebral amyloid angiopaphy (CAA), blood brain barrier (BBB) breakdown, and cognitive impairment were also detected in aged eNOS(+/-) mice. These data provide for the first time the evidence that partial eNOS deficiency results in spontaneous thrombotic cerebral infarctions that increase with age, leading to progressive CAA and cognitive impairments. We thus conclude that eNOS(+/-) mouse may represent an ideal model of ischemic stroke to address early and progressive damage in spontaneously-evolving chronic cerebral ischemia and thus, study vascular mechanisms contributing to vascular dementia and AD.

  2. Phenotyping of nNOS neurons in the postnatal and adult female mouse hypothalamus.

    PubMed

    Chachlaki, Konstantina; Malone, Samuel A; Qualls-Creekmore, Emily; Hrabovszky, Erik; Münzberg, Heike; Giacobini, Paolo; Ango, Fabrice; Prevot, Vincent

    2017-10-15

    Neurons expressing nitric oxide (NO) synthase (nNOS) and thus capable of synthesizing NO play major roles in many aspects of brain function. While the heterogeneity of nNOS-expressing neurons has been studied in various brain regions, their phenotype in the hypothalamus remains largely unknown. Here we examined the distribution of cells expressing nNOS in the postnatal and adult female mouse hypothalamus using immunohistochemistry. In both adults and neonates, nNOS was largely restricted to regions of the hypothalamus involved in the control of bodily functions, such as energy balance and reproduction. Labeled cells were found in the paraventricular, ventromedial, and dorsomedial nuclei as well as in the lateral area of the hypothalamus. Intriguingly, nNOS was seen only after the second week of life in the arcuate nucleus of the hypothalamus (ARH). The most dense and heavily labeled population of cells was found in the organum vasculosum laminae terminalis (OV) and the median preoptic nucleus (MEPO), where most of the somata of the neuroendocrine neurons releasing GnRH and controlling reproduction are located. A great proportion of nNOS-immunoreactive neurons in the OV/MEPO and ARH were seen to express estrogen receptor (ER) α. Notably, almost all ERα-immunoreactive cells of the OV/MEPO also expressed nNOS. Moreover, the use of EYFP Vglut2 , EYFP Vgat , and GFP Gad67 transgenic mouse lines revealed that, like GnRH neurons, most hypothalamic nNOS neurons have a glutamatergic phenotype, except for nNOS neurons of the ARH, which are GABAergic. Altogether, these observations are consistent with the proposed role of nNOS neurons in physiological processes. © 2017 Wiley Periodicals, Inc.

  3. 49 CFR 173.187 - Pyrophoric solids, metals or alloys, n.o.s.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 2 2011-10-01 2011-10-01 false Pyrophoric solids, metals or alloys, n.o.s. 173... Class 1 and Class 7 § 173.187 Pyrophoric solids, metals or alloys, n.o.s. Packagings for pyrophoric solids, metals, or alloys, n.o.s. must conform to the requirements of part 178 of this subchapter at the...

  4. Nature of Science Progression in School Year 1-9: a Case Study of Teachers' Suggestions and Rationales

    NASA Astrophysics Data System (ADS)

    Leden, Lotta; Hansson, Lena

    2017-07-01

    The inclusion of nature of science (NOS) in science education has for a long time been regarded as crucial. There is, however, a lack of research on appropriate NOS aspects for different educational levels. An even more neglected area of research is that focusing on teachers' perspectives on NOS teaching at different levels. The aim of this article is to examine NOS progression in the light of teachers' suggestions and rationales. In order to obtain teachers' informed perspectives, we chose to involve six teachers (teaching grades 1-9) in a 3-year research project. They took part in focus group discussions about NOS and NOS teaching as well as implemented jointly planned NOS teaching sessions. Data that this article builds on was collected at the end of the project. The teachers' suggestions for NOS progression often relied on adding more NOS issues at every stage, thereby creating the foundations of a broader but not necessarily deeper understanding of NOS. Five rationales, for if/when specific NOS issues are appropriate to introduce, emerged from the analysis of the teacher discussions. Some of these rationales, including practice makes perfect and increasing levels of depth can potentially accommodate room for many NOS issues in the science classroom, while maturity and experience instead has a restricting effect on NOS teaching. Also, choice of context and teaching approaches play an important role in teachers' rationales for whether specific NOS issues should be included or not at different stages. The article discusses the implications for teacher education and professional development.

  5. Mendelian Genetics as a Platform for Teaching about Nature of Science and Scientific Inquiry: The Value of Textbooks

    ERIC Educational Resources Information Center

    Campanile, Megan F.; Lederman, Norman G.; Kampourakis, Kostas

    2015-01-01

    The purpose of this study was to analyze seven widely used high school biology textbooks in order to assess the nature of science knowledge (NOS) and scientific inquiry (SI) aspects they, explicitly or implicitly, conveyed in the Mendelian genetics sections. Textbook excerpts that directly and/or fully matched our statements about NOS and SI were…

  6. Exposure to diesel exhaust up-regulates iNOS expression in ApoE knockout mice

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bai Ni; James Hogg Research Centre, Providence Heart and Lung Institute, St. Paul's Hospital, University of British Columbia, Vancouver, BC; Kido, Takashi

    Traffic related particulate matter air pollution is a risk factor for cardiovascular events; however, the biological mechanisms are unclear. We hypothesize that diesel exhaust (DE) inhalation induces up-regulation of inducible nitric oxide synthase (iNOS), which is known to contribute to vascular dysfunction, progression of atherosclerosis and ultimately cardiovascular morbidity and mortality. Methods: ApoE knockout mice (30-week) were exposed to DE (at 200 {mu}g/m{sup 3} of particulate matter) or filtered-air (control) for 7 weeks (6 h/day, 5 days/week). iNOS expression in the blood vessels and heart was evaluated by immunohistochemistry and western blotting analysis. To examine iNOS activity, thoracic aortae weremore » mounted in a wire myograph, and vasoconstriction stimulated by phenylephrine (PE) was measured with and without the presence of the specific inhibitor for iNOS (1400 W). NF-{kappa}B (p65) activity was examined by ELISA. The mRNA expression of iNOS and NF-{kappa}B (p65) was determined by real-time PCR. Results: DE exposure significantly enhanced iNOS expression in the thoracic aorta (4-fold) and heart (1.5 fold). DE exposure significantly attenuated PE-stimulated vasoconstriction by {approx} 20%, which was partly reversed by 1400 W. The mRNA expression of iNOS and NF-{kappa}B was significantly augmented after DE exposure. NF-{kappa}B activity was enhanced 2-fold after DE inhalation, and the augmented NF-{kappa}B activity was positively correlated with iNOS expression (R{sup 2} = 0.5998). Conclusions: We show that exposure to DE increases iNOS expression and activity possibly via NF-{kappa}B-mediated pathway. We suspect that DE exposure-caused up-regulation of iNOS contributes to vascular dysfunction and atherogenesis, which could ultimately lead to urban air pollution-associated cardiovascular morbidity and mortality. - Highlights: > Exposed ApoE knockout mice (30-week) to diesel exhaust (DE) for 7 weeks. > Examine iNOS expression and activity in

  7. Urinary tract infection in iNOS-deficient mice with focus on bacterial sensitivity to nitric oxide.

    PubMed

    Poljakovic, Mirjana; Persson, Katarina

    2003-01-01

    Inducible nitric oxide synthase (iNOS)-deficient mice were used to examine the role of iNOS in Escherichia coli-induced urinary tract infection (UTI). The toxicity of nitric oxide (NO)/peroxynitrite to bacteria and host was also investigated. The nitrite levels in urine of iNOS+/+ but not iNOS/ mice increased after infection. No differences in bacterial clearance or persistence were noted between the genotypes. In vitro, the uropathogenic E. coli 1177 was sensitive to 3-morpholinosydnonimine, whereas the avirulent E. coli HB101 was sensitive to both NO and 3-morpholinosydnonimine. E. coli HB101 was statistically (P < 0.05) more sensitive to peroxynitrite than E. coli 1177. Nitrotyrosine immunoreactivity was observed in infected bladders of both genotypes and in infected kidneys of iNOS+/+ mice. Myeloperoxidase, neuronal (n)NOS, and endothelial (e)NOS immunoreactivity was observed in inflammatory cells of both genotypes. Our results indicate that iNOS/ and iNOS+/+ mice are equally susceptible to E. coli-induced UTI and that the toxicity of NO to E. coli depends on bacterial virulence. Furthermore, myeloperoxidase and nNOS/eNOS may contribute to nitrotyrosine formation in the absence of iNOS.

  8. Post-translational regulation of endothelial nitric oxide synthase (eNOS) by estrogens in the rat vagina.

    PubMed

    Musicki, Biljana; Liu, Tongyun; Strong, Travis D; Lagoda, Gwen A; Bivalacqua, Trinity J; Burnett, Arthur L

    2010-05-01

    Estrogens control vaginal blood flow during female sexual arousal mostly through nitric oxide (NO). Although vascular effects of estrogens are attributed to an increase in endothelial NO production, the mechanisms of endothelial NO synthase (eNOS) regulation by estrogens in the vagina are largely unknown. Our hypothesis was that estrogens regulate eNOS post-translationally in the vagina, providing a mechanism to affect NO bioavailability without changes in eNOS protein expression. We measured eNOS phosphorylation and eNOS interaction with caveolin-1 and heat shock protein 90 (HSP90) in the distal and proximal vagina of female rats at diestrus, 7 days after ovariectomy and 2 days after replacement of ovariectomized rats with estradiol-17beta (15 microg). Molecular mechanisms of eNOS regulation by estrogen in the rat vagina. We localized phospho-eNOS (Ser-1177) immunohistochemically to the endothelium lining blood vessels and vaginal sinusoids. Estrogen withdrawal decreased phosphorylation of eNOS on its positive regulatory site (Ser-1177) and increased eNOS binding to its negative regulator caveolin-1 (without affecting eNOS/HSP90 interaction), and they were both normalized by estradiol replacement. Protein expressions of phosphorylated Akt (protein kinase B) and extracellular signal-regulated protein kinase 1/2 (ERK1/2) were not affected by estrogen status, suggesting that the effect of estrogens on eNOS (Ser-1177) phosphorylation was not mediated by activated AKT or ERK1/2. eNOS phosphorylation on its negative regulatory site (Ser-114) was increased in the vagina by estrogen withdrawal and normalized by estradiol replacement, implying that the maintenance of low phosphorylation of eNOS on this site by estradiol may limit eNOS interaction with caveolin-1 and preserve the enzyme's activity. Total eNOS, inducible NOS, caveolin-1, and HSP90 protein expressions were not affected by ovariectomy or estradiol replacement in the distal or proximal vagina. These results

  9. The Inclusion of the Nature of Science and Its Elements in Recent Popular Science Writing for Adults and Young Adults

    ERIC Educational Resources Information Center

    Jiang, Feng

    2012-01-01

    This study was conducted to examine the inclusion of nature of science (NOS) in popular science writing to determine whether it could serve supplementary resource for teaching NOS. Four groups of documents published from 2001 to 2010 were included in the analysis: "Scientific American," "Discover" magazine, winners of the…

  10. 15 CFR Supplement Nos.1-3 to Part 746 - [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 2 2010-01-01 2010-01-01 false [Reserved] Nos.1 Supplement Nos.1-3 to Part 746 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE EXPORT ADMINISTRATION REGULATIONS EMBARGOES AND...

  11. Voltage-dependent calcium channel involvement in NMDA-induced activation of NOS.

    PubMed

    Alagarsamy, S; Johnson, K M

    1995-11-13

    We have previously shown that N-methyl-D-aspartate (NMDA) increases nitric oxide synthase (NOS) activity in rat frontal cortex; however, the actual mechanism of this activation has not been addressed. Tetrodotoxin (TTX; 0.05 microM) inhibited NMDA-activated NOS, suggesting that TTX-sensitive Na+ channels are interposed between the NMDA receptors and the NOS cellular compartment. The NMDA response was also blocked by voltage-dependent Ca2+ channel (VDCC) blockers including Cd2+, Co2+, funnel web spider toxin (FTX) and omega-Aga IVa, but not by nifedipine or omega-conotoxin. These data suggest that Ca2+ flux through P- and/or Q-type VDCC subsequent to NMDA-induced depolarization may be at least as important for NOS activation as Ca2+ entry through the NMDA receptor.

  12. Circulating Blood eNOS Contributes to the Regulation of Systemic Blood Pressure and Nitrite Homeostasis

    PubMed Central

    Wood, Katherine C.; Cortese-Krott, Miriam M.; Kovacic, Jason C.; Noguchi, Audrey; Liu, Virginia B.; Wang, Xunde; Raghavachari, Nalini; Boehm, Manfred; Kato, Gregory J.; Kelm, Malte; Gladwin, Mark T.

    2013-01-01

    Objective Mice genetically deficient in endothelial nitric oxide synthase (eNOS−/−) are hypertensive with lower circulating nitrite levels, indicating the importance of constitutively produced nitric oxide (NO•) to blood pressure regulation and vascular homeostasis. While the current paradigm holds that this bioactivity derives specifically from expression of eNOS in endothelium, circulating blood cells also express eNOS protein. A functional red cell eNOS that modulates vascular NO• signaling has been proposed. Approach and Results To test the hypothesis that blood cells contribute to mammalian blood pressure regulation via eNOS-dependent NO• generation, we cross-transplanted WT and eNOS−/− mice, producing chimeras competent or deficient for eNOS expression in circulating blood cells. Surprisingly, we observed a significant contribution of both endothelial and circulating blood cell eNOS to blood pressure and systemic nitrite levels, the latter being a major component of the circulating NO• reservoir. These effects were abolished by the NOS inhibitor L-NAME and repristinated by the NOS substrate L-Arginine, and were independent of platelet or leukocyte depletion. Mouse erythrocytes were also found to carry an eNOS protein and convert 14C-Arginine into 14C-Citrulline in a NOS-dependent fashion. Conclusions These are the first studies to definitively establish a role for a blood borne eNOS, using cross transplant chimera models, that contributes to the regulation of blood pressure and nitrite homeostasis. This work provides evidence suggesting that erythrocyte eNOS may mediate this effect. PMID:23702660

  13. Teaching the Nature of Science with Scientific Narratives

    ERIC Educational Resources Information Center

    Adúriz-Bravo, Agustín

    2014-01-01

    The aim of this paper is to discuss the use of short science stories based on the history of science for science teacher education. Such stories are implemented to acquaint prospective and practicing science teachers in all educational levels with a conceptualisation of the nature of science (NOS) drawing from recent and contemporary developments…

  14. Introducing Taiwanese Undergraduate Students to the Nature of Science through Nobel Prize Stories

    ERIC Educational Resources Information Center

    Eshach, Haim; Hwang, Fu-Kwun; Wu, Hsin-Kai; Hsu, Ying-Shao

    2013-01-01

    Although there is a broad agreement among scientists and science educators that students should not only learn science, but also acquire some sense of its nature, it has been reported that undergraduate students possess an inadequate grasp of the nature of science (NOS). The study presented here examined the potential and effectiveness of Nobel…

  15. Emphasizing the History of Genetics in an Explicit and Reflective Approach to Teaching the Nature of Science: A Pilot Study

    ERIC Educational Resources Information Center

    Williams, Cody Tyler; Rudge, David Wÿss

    2016-01-01

    Science education researchers have long advocated the central role of the nature of science (NOS) for our understanding of scientific literacy. NOS is often interpreted narrowly to refer to a host of epistemological issues associated with the process of science and the limitations of scientific knowledge. Despite its importance, practitioners and…

  16. Decreased production of neuronal NOS-derived hydrogen peroxide contributes to endothelial dysfunction in atherosclerosis

    PubMed Central

    Capettini, LSA; Cortes, SF; Silva, JF; Alvarez-Leite, JI; Lemos, VS

    2011-01-01

    BACKGROUND AND PURPOSE Reduced NO availability has been described as a key mechanism responsible for endothelial dysfunction in atherosclerosis. We previously reported that neuronal NOS (nNOS)-derived H2O2 is an important endothelium-derived relaxant factor in the mouse aorta. The role of H2O2 and nNOS in endothelial dysfunction in atherosclerosis remains undetermined. We hypothesized that a decrease in nNOS-derived H2O2 contributes to the impaired vasodilatation in apolipoprotein E-deficient mice (ApoE−/−). EXPERIMENTAL APPROACH Changes in isometric tension were recorded on a myograph; simultaneously, NO and H2O2 were measured using carbon microsensors. Antisense oligodeoxynucleotides were used to knockdown eNOS and nNOS in vivo. Western blot and confocal microscopy were used to analyse the expression and localization of NOS isoforms. KEY RESULTS Aortas from ApoE−/− mice showed impaired vasodilatation paralleled by decreased NO and H2O2 production. Inhibition of nNOS with L-ArgNO2-L-Dbu, knockdown of nNOS and catalase, which decomposes H2O2 into oxygen and water, decreased ACh-induced relaxation by half, produced a small diminution of NO production and abolished H2O2 in wild-type animals, but had no effect in ApoE−/− mice. Confocal microscopy showed increased nNOS immunostaining in endothelial cells of ApoE−/− mice. However, ACh stimulation of vessels resulted in less phosphorylation on Ser852 in ApoE−/− mice. CONCLUSIONS AND IMPLICATIONS Our data show that endothelial nNOS-derived H2O2 production is impaired and contributes to endothelial dysfunction in ApoE−/− aorta. The present study provides a new mechanism for endothelial dysfunction in atherosclerosis and may represent a novel target to elaborate the therapeutic strategy for vascular atherosclerosis. PMID:21615722

  17. Views from the Chalkface. Values of Teaching Nature of Science in Hong Kong

    NASA Astrophysics Data System (ADS)

    Wan, Zhi Hong; Wong, Siu Ling

    2016-12-01

    Although the goal of developing school students' understanding of nature of science (NOS) has long been advocated, there is still a lack of research that focuses on probing how science teachers, a kind of major stakeholder in NOS instruction, perceive the values of teaching NOS. Through semi-structured interviews, this study investigated the views of 15 Hong Kong in-service senior secondary science teachers about the values of teaching NOS. These values as perceived by the teachers fall into two types. The first type is related to students' learning of science in the classroom and involves: (i) facilitating the study of subject knowledge, (ii) increasing the interest in learning science, (iii) supporting the conduct of scientific inquiry, (iv) meeting the needs of public examinations, and (v) fulfilling the requirement of learning science. The second type goes beyond learning science and includes (i) developing thinking skills, (ii) cultivating scientific ethics in students, and (iii) supporting the participation in public decisions on socioscientific issues. Although rich relationships were perceived by these teachers between NOS instruction and students' learning of science, few values were stated from broad social and cultural perspectives. Suggestions are made about developing teachers' views of the values of teaching NOS so as to influence their intention of teaching it.

  18. Development of an Empirically Based Questionnaire to Investigate Young Students' Ideas about Nature of Science

    ERIC Educational Resources Information Center

    Chen, Sufen; Chang, Wen-Hua; Lieu, Sang-Chong; Kao, Huey-Lien; Huang, Mao-Tsai; Lin, Shu-Fen

    2013-01-01

    This study developed an empirically based questionnaire to monitor young learners' conceptions of nature of science (NOS). The questionnaire, entitled Students' Ideas about Nature of Science (SINOS), measured views on theory-ladenness, use of creativity and imagination, tentativeness of scientific knowledge, durability of scientific knowledge,…

  19. Supporting Teachers' Understanding of Nature of Science and Inquiry Through Personal Experience and Perception of Inquiry as a Dynamic Process

    NASA Astrophysics Data System (ADS)

    Zion, Michal; Schwartz, Renee S.; Rimerman-Shmueli, Esther; Adler, Idit

    2018-05-01

    One of today's challenges in science education involves the development of appropriate conceptions of inquiry teaching and realizing how these experiences can support students' understanding of the nature of science and inquiry (NOS and NOSI). To meet this challenge, we developed a course for in-service science teachers, in which explicit-reflective instruction of NOS was coupled with an open inquiry process. This process included documentation tools adjusted to emphasize the dynamic, logical, and reflective aspects of scientific inquiry. Teachers' documentations, reflections, and questionnaires were examined for indications of perceptual connection between comprehending the essence of dynamic open inquiry and understanding certain NOS tenets. The results indicated that the in-service teachers experienced all criteria of dynamic open inquiry, however not to the same extent. By focusing on four teachers who clearly addressed changes in their perspective of NOS and NOSI, we were able to examine the nature of those changes, and relate them to the teachers' personal experiences and perceptions of the characteristics of dynamic open inquiry. Our results suggest that the participants' personal experiences and perceptions of the dynamic characteristics of open inquiry play a crucial role in shaping their understanding of NOS and NOSI. The findings of this research underscore the importance of enhancing teachers' personal experiences and perceptions of the dynamic characteristics of open inquiry, as a vehicle to improve their understanding of NOS and NOSI.

  20. The mTOR kinase inhibitor rapamycin decreases iNOS mRNA stability in astrocytes

    PubMed Central

    2011-01-01

    Background Reactive astrocytes are capable of producing a variety of pro-inflammatory mediators and potentially neurotoxic compounds, including nitric oxide (NO). High amounts of NO are synthesized following up-regulation of inducible NO synthase (iNOS). The expression of iNOS is tightly regulated by complex molecular mechanisms, involving both transcriptional and post-transcriptional processes. The mammalian target of rapamycin (mTOR) kinase modulates the activity of some proteins directly involved in post-transcriptional processes of mRNA degradation. mTOR is a serine-threonine kinase that plays an evolutionarily conserved role in the regulation of cell growth, proliferation, survival, and metabolism. It is also a key regulator of intracellular processes in glial cells. However, with respect to iNOS expression, both stimulatory and inhibitory actions involving the mTOR pathway have been described. In this study the effects of mTOR inhibition on iNOS regulation were evaluated in astrocytes. Methods Primary cultures of rat cortical astrocytes were activated with different proinflammatory stimuli, namely a mixture of cytokines (TNFα, IFNγ, and IL-1β) or by LPS plus IFNγ. Rapamycin was used at nM concentrations to block mTOR activity and under these conditions we measured its effects on the iNOS promoter, mRNA and protein levels. Functional experiments to evaluate iNOS activity were also included. Results In this experimental paradigm mTOR activation did not significantly affect astrocyte iNOS activity, but mTOR pathway was involved in the regulation of iNOS expression. Rapamycin did not display any significant effects under basal conditions, on either iNOS activity or its expression. However, the drug significantly increased iNOS mRNA levels after 4 h incubation in presence of pro-inflammatory stimuli. This stimulatory effect was transient, since no differences in either iNOS mRNA or protein levels were detected after 24 h. Interestingly, reduced levels of iNOS

  1. A conceptual change analysis of nature of science conceptions: The deep roots and entangled vines of a conceptual ecology

    NASA Astrophysics Data System (ADS)

    Johnston, Adam Thomas

    This research used theories of conceptual change to analyze learners' understandings of the nature of science (NOS). Ideas regarding the NOS have been advocated as vital aspects of science literacy, yet learners at many levels (students and teachers) have difficulty in understanding these aspects in the way that science literacy reforms advocate. Although previous research has shown the inadequacies in learners' NOS understandings and have documented ways by which to improve some of these understandings, little has been done to show how these ideas develop and why learners' preexisting conceptions of NOS are so resistant to conceptual change. The premise of this study, then, was to describe the nature of NOS conceptions and of the conceptual change process itself by deeply analyzing the conceptions of individual learners. Toward this end, 4 individuals enrolled in a physical science course designed for preservice elementary teachers were selected to participate in a qualitative research study. These individuals answered questionnaires, surveys, direct interview questions, and a variety of interview probes (e.g., critical incidents, responses to readings/videos, reflections on coursework, card sorting tasks, etc.) which were administered throughout the duration of a semester. By utilizing these in-depth, qualitative probes, learners' conceptions were not only assessed but also described in great detail, revealing the source of their conceptions as well as identifying many instances in which a learner's directly stated conception was contradictory to that which was reflected by more indirect probes. As a result of this research, implications regarding NOS conceptions and their development have been described. In addition, various descriptions of conceptual change have been further refined and informed. Especially notable, the influence of a learner's conceptual ecology and its extrarational influences on conceptual change have been highlighted. It is argued that

  2. Post-translational Regulation of Endothelial Nitric Oxide Synthase (eNOS) by Estrogens in the Rat Vagina

    PubMed Central

    Musicki, Biljana; Liu, Tongyun; Strong, Travis D.; Lagoda, Gwen A.; Bivalacqua, Trinity J.; Burnett, Arthur L.

    2010-01-01

    Introduction Estrogens control vaginal blood flow during female sexual arousal mostly through nitric oxide (NO). Although vascular effects of estrogens are attributed to an increase in endothelial NO production, the mechanisms of endothelial NO synthase (eNOS) regulation by estrogens in the vagina are largely unknown. Aims Our hypothesis was that estrogens regulate eNOS post-translationally in the vagina, providing a mechanism to affect NO bioavailability without changes in eNOS protein expression. Methods We measured eNOS phosphorylation and eNOS interaction with caveolin-1 and heat shock protein 90 (HSP90) in the distal and proximal vagina of female rats at diestrus, 7 days after ovariectomy and 2 days after replacement of ovariectomized rats with estradiol-17β (15 μg). Main Outcome Measures Molecular mechanisms of eNOS regulation by estrogen in the rat vagina. Results We localized phospho-eNOS (Ser-1177) immunohistochemically to the endothelium lining blood vessels and vaginal sinusoids. Estrogen withdrawal decreased phosphorylation of eNOS on its positive regulatory site (Ser-1177) and increased eNOS binding to its negative regulator caveolin-1 (without affecting eNOS/HSP90 interaction), and they were both normalized by estradiol replacement. Protein expressions of phosphorylated Akt (protein kinase B) and extracellular signal-regulated protein kinase 1/2 (ERK1/2) were not affected by estrogen status, suggesting that the effect of estrogens on eNOS (Ser-1177) phosphorylation was not mediated by activated AKT or ERK1/2. eNOS phosphorylation on its negative regulatory site (Ser-114) was increased in the vagina by estrogen withdrawal and normalized by estradiol replacement, implying that the maintenance of low phosphorylation of eNOS on this site by estradiol may limit eNOS interaction with caveolin-1 and preserve the enzyme's activity. Total eNOS, inducible NOS, caveolin-1, and HSP90 protein expressions were not affected by ovariectomy or estradiol replacement

  3. Explicit Reflective Nature of Science Instruction: Evolution, Intelligent Design, and Umbrellaology

    NASA Astrophysics Data System (ADS)

    Scharmann, Lawrence C.; Smith, Mike U.; James, Mark C.; Jensen, Murray

    2005-02-01

    The investigators sought to design an instructional unit to enhance an understanding of the nature of science (NOS) by taking into account both instructional best practices and suggestions made by noted science philosopher Thomas Kuhn. Preservice secondary science teachers enrolled in a course, Laboratory Techniques in the Teaching of Science, served as participants in action research. Sources of data used to inform instructional decisions included students written reaction papers to the assigned readings, transcribed verbal comments made during class discussions and other in-class activities, and final reflection essays. Three iterative implementations of the instructional unit were attempted. The objectives of the study were essentially met. The instructional unit was able to provoke preservice teachers into wrestling with many substantive issues associated with the NOS. Implications concerning the design of explicit reflective NOS instruction are included.

  4. A Critical Review: Connecting Nature of Science and Argumentation

    ERIC Educational Resources Information Center

    Soysal, Y.

    2015-01-01

    The purpose of this critical review is to examine studies incorporating interconnectedness between Nature of Science (NOS) and Argumentation. This in-depth critical review seeks to illuminate insights and direction of the linkage between these two eminent research fields in science education. It involves a computerized, web-based search to provide…

  5. NOS2 deficiency has no influence on the radiosensitivity of the hematopoietic system.

    PubMed

    Li, Chengcheng; Luo, Yi; Shao, Lijian; Meng, Aimin; Zhou, Daohong

    2018-01-01

    Previous studies have shown that inhibition of inducible NO synthase (NOS2 or iNOS) with an inhibitor can selectively protect several normal tissues against radiation during radiotherapy. However, the role of NOS2 in ionizing radiation (IR)-induced bone marrow (BM) suppression is unknown and thus was investigated in the present study using NOS2 - / - and wild-type mice 14 days after they were exposed to a sublethal dose of total body irradiation (TBI). The effects of different doses of IR (1, 2 and 4 Gy) on the apoptosis and colony-forming ability of bone marrow cells from wild-type (WT) and NOS2 - / - mice were investigated in vitro. In addition, we exposed NOS2 - / - mice and WT mice to 6-Gy TBI or sham irradiation. They were euthanized 14 days after TBI for analysis of peripheral blood cell counts and bone marrow cellularity. Colony-forming unit-granulocyte and macrophage, burst-forming unit-erythroid and CFU-granulocyte, erythroid, macrophage in bone marrow cells from the mice were determined to evaluate the function of hematopoietic progenitor cells (HPCs), and the ability of hematopoietic stem cells (HSCs) to self-renew was analysed by the cobblestone area forming cell assay. The cell cycling of HPCs and HSCs were measured by flow cytometry. Exposure to 2 and 4 Gy IR induced bone marrow cell apoptosis and inhibited the proliferation of HPCs in vitro. However, there was no difference between the cells from WT mice and NOS2 - / - mice in response to IR exposure in vitro. Exposure of WT mice and NOS2 - / - mice to 6 Gy TBI decreased the white blood cell, red blood cell, and platelet counts in the peripheral blood and bone marrow mononuclear cells, and reduced the colony-forming ability of HPCs (P < 0.05), damaged the clonogenic function of HSCs. However, these changes were not significantly different in WT and NOS2 - / - mice. These data suggest that IR induces BM suppression in a NOS2-independent manner.

  6. Transfer of Nature of Science Understandings into Similar Contexts: Promises and Possibilities of an Explicit Reflective Approach

    NASA Astrophysics Data System (ADS)

    Khishfe, Rola

    2013-11-01

    The purpose of this study was to (a) investigate the effectiveness of explicit nature of science (NOS) instruction in the context of controversial socioscientific issues and (b) explore whether the transfer of acquired NOS understandings, which were explicitly taught in the context of one socioscientific context, into other similar contexts (familiar and unfamiliar) was possible. Participants were 10th grade students in two intact sections at one high school. The treatment involved teaching a six-week unit about genetic engineering. For one group (non-NOS group), there was no explicit instruction about NOS. For the other group (NOS group), explicit instruction about three NOS aspects (subjective, empirical, and tentative) was dispersed across the genetic engineering unit. A questionnaire including two open-ended scenarios, in conjunction with semi-structured interviews, was used to assess the change in participants' understandings of NOS and their ability to transfer their acquired understandings into similar contexts. The first scenario involved a familiar context about genetically modified food and the second one focused on an unfamiliar context about water fluoridation. Results showed no improvement in NOS understandings of participants in the non-NOS group in relation to the familiar and unfamiliar contexts. On the other hand, there was a general improvement in the NOS understandings of participants in the NOS group in relation to both the familiar and unfamiliar contexts. Implications about the transfer of participants' acquired NOS understandings on the basis of the distance between the context of learning and that of application are highlighted and discussed in link with the classroom learning environment.

  7. The Cultural Argument for Understanding Nature of Science: A Chance to Reflect on Similarities and Differences Between Science and Humanities

    ERIC Educational Resources Information Center

    Reiners, Christiane S.; Bliersbach, Markus; Marniok, Karl

    2017-01-01

    Understanding Nature of Science (NOS) is a central component of scientific literacy, which is agreed upon internationally, and consequently has been a major educational goal for many years all over the globe. In order to justify the promotion of an adequate understanding of NOS, educators have developed several arguments, among them the cultural…

  8. Exploring Elementary Teachers' Perceptions about the Developmental Appropriateness and Importance of Nature of Science Aspects

    ERIC Educational Resources Information Center

    Sahin, Elif Adibelli; Deniz, Hasan

    2016-01-01

    This study explored how four elementary teachers assessed the developmental appropriateness and importance of nine nature of science (NOS) aspects after participating in a yearlong professional development program. A multiple-embedded case study design was employed. The primary data sources included (a) Views of Nature of Science Elementary School…

  9. Using the History of Research on Sickle Cell Anemia to Affect Preservice Teachers' Conceptions of the Nature of Science.

    ERIC Educational Resources Information Center

    Howe, Eric M.

    This paper examines how using a series of lessons developed from the history of research on sickle cell anemia affects preservice teacher conceptions of the nature of science (NOS). The importance of a pedagogy that has students do science through an integral use of the history of science is effective at enriching students' NOS views is presented.…

  10. Folic acid modulates eNOS activity via effects on posttranslational modifications and protein–protein interactions☆

    PubMed Central

    Taylor, Sarah Y.; Dixon, Hannah M.; Yoganayagam, Shobana; Price, Natalie; Lang, Derek

    2013-01-01

    Folic acid enhances endothelial function and improves outcome in primary prevention of cardiovascular disease. The exact intracellular signalling mechanisms involved remain elusive and were therefore the subject of this study. Particular focus was placed on folic acid-induced changes in posttranslational modifications of endothelial nitric oxide synthase (eNOS). Cultured endothelial cells were exposed to folic acid in the absence or presence of phosphatidylinositol-3' kinase/Akt (PI3K/Akt) inhibitors. The phosphorylation status of eNOS was determined via western blotting. The activities of eNOS and PI3K/Akt were evaluated. The interaction of eNOS with caveolin-1, Heat-Shock Protein 90 and calmodulin was studied using co-immunoprecipitation. Intracellular localisation of eNOS was investigated using sucrose gradient centrifugation and confocal microscopy. Folic acid promoted eNOS dephosphorylation at negative regulatory sites, and increased phosphorylation at positive regulatory sites. Modulation of phosphorylation status was concomitant with increased cGMP concentrations, and PI3K/Akt activity. Inhibition of PI3K/Akt revealed specific roles for this kinase pathway in folic acid-mediated eNOS phosphorylation. Regulatory protein and eNOS protein associations were altered in favour of a positive regulatory effect in the absence of bulk changes in intracellular eNOS localisation. Folic acid-mediated eNOS activation involves the modulation of eNOS phosphorylation status at multiple residues and positive changes in important protein–protein interactions. Such intracellular mechanisms may in part explain improvements in clinical vascular outcome following folic acid treatment. PMID:23796957

  11. The `Nature of Science' and the Perils of Epistemic Relativism

    NASA Astrophysics Data System (ADS)

    Romero-Maltrana, Diego; Benitez, Federico; Vera, Francisco; Rivera, Rodrigo

    2017-11-01

    There is an increasing demand in the field of science education for the incorporation of philosophical and sociological aspects that are related to the scientific enterprise in school curricula, to the extent that the incorporation of these aspects is now considered a necessity. Several of these aspects can be categorised within the framework of the nature of science, or NOS. We warn that a possible misinterpretation of the common view of NOS tenets can lead to epistemic relativism. We pay special attention to the empirical and objective nature of science because these important features, properly understood, can help eliminate subjective flaws and protect against relativism. Some of the epistemological concepts that are relevant to this discussion are disambiguated in an attempt to prevent the temptation to take views to an extreme, as has occurred in some cases. We expect this analysis to contribute to the extant literature by improving how science is presented in the classroom without oversimplifying scientific practice.

  12. Many-body calculations with deuteron based single-particle bases and their associated natural orbits

    NASA Astrophysics Data System (ADS)

    Puddu, G.

    2018-06-01

    We use the recently introduced single-particle states obtained from localized deuteron wave-functions as a basis for nuclear many-body calculations. We show that energies can be substantially lowered if the natural orbits (NOs) obtained from this basis are used. We use this modified basis for {}10{{B}}, {}16{{O}} and {}24{{Mg}} employing the bare NNLOopt nucleon–nucleon interaction. The lowering of the energies increases with the mass. Although in principle NOs require a full scale preliminary many-body calculation, we found that an approximate preliminary many-body calculation, with a marginal increase in the computational cost, is sufficient. The use of natural orbits based on an harmonic oscillator basis leads to a much smaller lowering of the energies for a comparable computational cost.

  13. Differences in microbial community structure and nitrogen cycling in natural and drained tropical peatland soils.

    PubMed

    Espenberg, Mikk; Truu, Marika; Mander, Ülo; Kasak, Kuno; Nõlvak, Hiie; Ligi, Teele; Oopkaup, Kristjan; Maddison, Martin; Truu, Jaak

    2018-03-16

    Tropical peatlands, which play a crucial role in the maintenance of different ecosystem services, are increasingly drained for agriculture, forestry, peat extraction and human settlement purposes. The present study investigated the differences between natural and drained sites of a tropical peatland in the community structure of soil bacteria and archaea and their potential to perform nitrogen transformation processes. The results indicate significant dissimilarities in the structure of soil bacterial and archaeal communities as well as nirK, nirS, nosZ, nifH and archaeal amoA gene-possessing microbial communities. The reduced denitrification and N 2 -fixing potential was detected in the drained tropical peatland soil. In undisturbed peatland soil, the N 2 O emission was primarily related to nirS-type denitrifiers and dissimilatory nitrate reduction to ammonium, while the conversion of N 2 O to N 2 was controlled by microbes possessing nosZ clade I genes. The denitrifying microbial community of the drained site differed significantly from the natural site community. The main reducers of N 2 O were microbes harbouring nosZ clade II genes in the drained site. Additionally, the importance of DNRA process as one of the controlling mechanisms of N 2 O fluxes in the natural peatlands of the tropics revealed from the results of the study.

  14. From FRA to RFN, or How the Family Resemblance Approach Can Be Transformed for Science Curriculum Analysis on Nature of Science

    ERIC Educational Resources Information Center

    Kaya, Ebru; Erduran, Sibel

    2016-01-01

    The inclusion of Nature of Science (NOS) in the science curriculum has been advocated around the world for several decades. One way of defining NOS is related to the family resemblance approach (FRA). The family resemblance idea was originally described by Wittgenstein. Subsequently, philosophers and educators have applied Wittgenstein's idea to…

  15. Quantitative Detection of the nosZ Gene, Encoding Nitrous Oxide Reductase, and Comparison of the Abundances of 16S rRNA, narG, nirK, and nosZ Genes in Soils

    PubMed Central

    Henry, S.; Bru, D.; Stres, B.; Hallet, S.; Philippot, L.

    2006-01-01

    Nitrous oxide (N2O) is an important greenhouse gas in the troposphere controlling ozone concentration in the stratosphere through nitric oxide production. In order to quantify bacteria capable of N2O reduction, we developed a SYBR green quantitative real-time PCR assay targeting the nosZ gene encoding the catalytic subunit of the nitrous oxide reductase. Two independent sets of nosZ primers flanking the nosZ fragment previously used in diversity studies were designed and tested (K. Kloos, A. Mergel, C. Rösch, and H. Bothe, Aust. J. Plant Physiol. 28:991-998, 2001). The utility of these real-time PCR assays was demonstrated by quantifying the nosZ gene present in six different soils. Detection limits were between 101 and 102 target molecules per reaction for all assays. Sequence analysis of 128 cloned quantitative PCR products confirmed the specificity of the designed primers. The abundance of nosZ genes ranged from 105 to 107 target copies g−1 of dry soil, whereas genes for 16S rRNA were found at 108 to 109 target copies g−1 of dry soil. The abundance of narG and nirK genes was within the upper and lower limits of the 16S rRNA and nosZ gene copy numbers. The two sets of nosZ primers gave similar gene copy numbers for all tested soils. The maximum abundance of nosZ and nirK relative to 16S rRNA was 5 to 6%, confirming the low proportion of denitrifiers to total bacteria in soils. PMID:16885263

  16. Expression of iNOS and NF-κB in melasma: an immunohistochemical study.

    PubMed

    Samaka, Rehab Monir; Bakry, Ola Ahmed; Shoeib, Mohamed Abd El Monaem; Zaaza, Marwa M

    2014-10-01

    To investigate the role of inducible nitric oxide synthases (iNOS) and nuclear factor-kappa B (NF-κB) in the pathogenesis of melasma through their immunohistochemical (IHC) co-localization in skin of melasma and to correlate their expression with the clinical and the histopathological data. This prospective case-control study was conducted on 34 female patients with melasma and 30 age- and gender-matched healthy subjects as a control group for evaluation of IHC expression of iNOS and NF-κB in melasma. There were significant differences between lesional and perilesional skin regarding iNOS intensity, iNOS histo-score (H-score), NF-κB intensity, and NF-κB H-score (p < 0.001 for all). There were significant associations between the higher values of H-scores for both iNOS and NF-κB and positive family history (p = 0.002 and p = 0.001, respectively) and very severe melasma areas and severity index score (p < 0.001 and p = 0.001, respectively). There was a positive correlation between H-score values of both iNOS and NF-κB (r = +0.604 and p < 0.001). The IHC co-localization and direct correlation of both iNOS and NF-κB in melasma could provide evidence about their role as co-players in melanogenesis and might provide new targets for a more efficient treatment for melasma.

  17. Deficiency of eNOS exacerbates early-stage NAFLD pathogenesis by changing the fat distribution.

    PubMed

    Nozaki, Yuichi; Fujita, Koji; Wada, Koichiro; Yoneda, Masato; Shinohara, Yoshiyasu; Imajo, Kento; Ogawa, Yuji; Kessoku, Takaomi; Nakamuta, Makoto; Saito, Satoru; Masaki, Naohiko; Nagashima, Yoji; Terauchi, Yasuo; Nakajima, Atsushi

    2015-12-17

    Although many factors and molecules that are closely associated with non-alcoholic fatty liver disease (NAFLD)/non-alcoholic steatohepatitis (NASH) have been reported, the role of endothelial nitric oxide synthase (eNOS)-derived nitric oxide (NO) in the pathogenesis of NAFLD/NASH remains unclear. We therefore investigated the role of eNOS-derived NO in NAFLD pathogenesis using systemic eNOS-knockout mice fed a high-fat diet. eNOS-knockout and wild-type mice were fed a basal diet or a high-fat diet for 12 weeks. Lipid accumulation and inflammation were evaluated in the liver, and various factors that are closely associated with NAFLD/NASH and hepatic tissue blood flow were analyzed. Lipid accumulation and inflammation were more extensive in the liver and lipid accumulation was less extensive in the visceral fat tissue in eNOS-knockout mice, compared with wild-type mice, after 12 weeks of being fed a high-fat diet. While systemic insulin resistance was comparable between the eNOS-knockout and wild-type mice fed a high-fat diet, hepatic tissue blood flow was significantly suppressed in the eNOS-knockout mice, compared with the wild-type mice, in mice fed a high-fat diet. The microsomal triglyceride transfer protein activity was down-regulated in eNOS-knockout mice, compared with wild-type mice, in mice fed a high-fat diet. A deficiency of eNOS-derived NO may exacerbate the early-stage of NASH pathogenesis by changing the fat distribution in a mouse model via the regulation of hepatic tissue blood flow.

  18. The Effects of Case-Based Instruction on Undergraduate Biology Students' Understanding of the Nature of Science

    NASA Astrophysics Data System (ADS)

    Burniston, Amy Lucinda

    Undergraduate science education is currently seeing a dramatic pedagogical push towards teaching the philosophies underpinning science as well as an increase in strategies that employ active learning. Many active learning strategies stem from constructivist ideals and have been shown to affect a student's understanding of how science operates and its impact on society- commonly referred to as the nature of science (NOS). One particular constructivist teaching strategy, case-based instruction (CBI), has been recommended by researchers and science education reformists as an effective instructional strategy for teaching NOS. Furthermore, when coupled with explicit-reflective instruction, CBI has been found to significantly increasing understanding of NOS in elementary and secondary students. However, few studies aimed their research on CBI and NOS towards higher education. Thus, this study uses a quasi-experimental, nonequivalent group design to study the effects of CBI on undergraduate science students understandings of NOS. Undergraduate biology student's understanding of NOS were assessed using the Views of Science Education (VOSE) instrument pre and post CBI intervention in Cellular and Molecular Biology and Human Anatomy and Physiology II. Data analysis indicated statistically significant differences between students NOS scores in experimental versus control sections for both courses, with experimental groups obtaining higher posttest scores. The results of this study indicate that undergraduate male and female students have similarly poor understandings of NOS and the use of historical case based instruction can be used as a means to increase undergraduate understanding of NOS.

  19. Investigating the Role of NOS2 in Breast Cancer | Center for Cancer Research

    Cancer.gov

    Inducible nitric oxide synthase (NOS2) is often elevated in breast tumors that lack expression of the estrogen receptor (ER) and predicts a poor prognosis for patients with these tumors. However, it is unclear whether NOS2 directly contributes to ER-negative breast cancer aggressiveness or how NOS2 expression is controlled within the tumor microenvironment. To tease apart the

  20. Common Interest, Common Visions? Chinese Science Teacher Educators' Views about the Values of Teaching Nature of Science to Prospective Science Teachers

    ERIC Educational Resources Information Center

    Wan, Zhi Hong; Wong, Siu Ling; Yung, Benny Hin Wai

    2011-01-01

    Teaching nature of science (NOS) is beginning to take root in science education in China. This exploratory study interviewed 24 science teacher educators from economically developed parts of China about their conceptions of teaching NOS to prospective science teachers. Five key dimensions emerged from the data. This paper focuses on the dimension…

  1. NOS1 mediates AP1 nuclear translocation and inflammatory response.

    PubMed

    Srivastava, Mansi; Baig, Mirza S

    2018-06-01

    A hallmark of the AP1 functioning is its nuclear translocation, which induces proinflammatory cytokine expression and hence the inflammatory response. After endotoxin shock AP1 transcription factor, which comprises Jun, ATF2, and Fos family of proteins, translocates into the nucleus and induces proinflammatory cytokine expression. In the current study, we found, NOS1 inhibition prevents nuclear translocation of the AP1 transcription factor subunits. Pharmacological inhibition of NOS1 impedes translocation of subunits into the nucleus, suppressing the transcription of inflammatory genes causing a diminished inflammatory response. In conclusion, the study shows the novel mechanism of NOS1- mediated AP1 nuclear translocation, which needs to be further explored. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  2. 77 FR 12010 - Marine Mammals; File Nos. 1076-1789 and 14502

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-28

    ... Mammals; File Nos. 1076-1789 and 14502 AGENCY: National Marine Fisheries Service (NMFS), National Oceanic... 80208, have been issued minor amendments to Scientific Research Permit Nos. 1076-1789 and 14502.... 1076-1789: This permit, issued on March 13, 2007 (72 FR 13092), authorized the receipt, import and...

  3. microRNAs regulate nitric oxide release from endothelial cells by targeting NOS3.

    PubMed

    Qin, Ji-Zheng; Wang, Shao-Jie; Xia, Chun

    2018-06-13

    Endothelial nitric oxide synthase (eNOS) encoded by nitric oxide synthase 3 (NOS3), can generate nitric oxide (NO) which serves as an important deterrent to the pathogenesis of thrombosis by modulating the activation, adhesion and aggregate formation of platelets. Three serum miRNAs (miR-195, miR-532 and miR-582) have been suggested as biomarkers for the diagnosis of deep vein thrombosis (DVT), however their potential roles in DVT is not clear. The effect of miRNAs inhibiting the expression of NOS3 was evaluated in vitro. miR-195, miR-532 and miR-582 mimic, inhibitor, and control miRNAs were transfected into endothelial cells. The roles of miR-195, miR-532 and miR-582 regulating the expression of eNOS were evaluated by real-time quantitative PCR, Western Blotting and luciferase reporter assays. NO release was measured by Griess method. We confirmed NOS3 as a direct target of miR-195 and miR-582, which binds to the 3'-UTR of NOS3 mRNA in endothelial cells. A significantly inverse correlation between these two miRNAs and eNOS expression was detected. NO release from endothelial cells was decreased when the expression level of miR-195 and miR-582 was up-regulated. These findings indicated that miR-195 and miR-582 regulated NO release by targeting 3'-UTR of NOS3 post-transcriptionally in endothelial cells. Therefore, miR-195 and miR-582 might play an important role in maintaining endothelial NO bioavailability and could be a novel target for treatment of thrombotic diseases.

  4. The Nature of Science as Viewed by Science Teachers in Najran District, Saudi Arabia

    ERIC Educational Resources Information Center

    Saif, Abdulsalam Dale Amer

    2016-01-01

    This study aims to investigate the views of Saudi Science Teachers in Najran district about the nature of science (NOS). A questionnaire of fourteen items was developed and administered to a sample of 83 science teachers. The questionnaire covers five aspects of the nature of science which are: scientific theories and models; role of scientists;…

  5. A historical examination of the nature of science and its consensus as presented in the Benchmarks for Science Literacy and National Science Education Standards

    NASA Astrophysics Data System (ADS)

    Felske, Daniel D.

    Developing a scientific literate citizenry has fueled science education reforms for the past 40 years. A review of the literature reveals that definitions of scientific literacy during this period were greatly influenced by the goals, directions, and political agendas of the day. This approach has resulted in programs emphasizing certain aspects of scientific literacy while neglecting others. Additionally, consensus on what scientific literacy means or how to develop it has not been achieved. One aspect of scientific literacy that is agreed upon is the essential role that the nature of science (NOS) plays in its development. For this reason, an extensive review of the literature was conducted to develop a comprehensive background of this topic. The component structure of the NOS revealed in the literature was then synthesized into a NOS framework. The NOS framework served to guide the construction of a 21 item questionnaire taken from statements embedded in the consensual documents Benchmarks for Science Literacy (AAAS, 1993) and National Science Education Standards (NRC, 1996). A panel of five experts who have written extensively on the nature of science was then assembled and the degree of NOS consensus measured using a modified Delphi technique. The results of the survey indicated a high level of consensus (95%) at the ≥80% level. The panelists concurred positively on 19 of 21 NOS items, concurred negatively on one of 21 NOS items (item 10), and could not reach consensus on one of 21 NOS items (item 16). These findings, as well as, the NOS framework, are important first steps toward developing programs that foster the development of scientific literacy.

  6. Inducible nitric oxide synthase (NOS-2) in subarachnoid hemorrhage: Regulatory mechanisms and therapeutic implications.

    PubMed

    Iqbal, Sana; Hayman, Erik G; Hong, Caron; Stokum, Jesse A; Kurland, David B; Gerzanich, Volodymyr; Simard, J Marc

    2016-01-01

    Aneurysmal subarachnoid hemorrhage (SAH) typically carries a poor prognosis. Growing evidence indicates that overabundant production of nitric oxide (NO) may be responsible for a large part of the secondary injury that follows SAH. Although SAH modulates the activity of all three isoforms of nitric oxide synthase (NOS), the inducible isoform, NOS-2, accounts for a majority of NO-mediated secondary injuries after SAH. Here, we review the indispensable physiological roles of NO that must be preserved, even while attempting to downmodulate the pathophysiologic effects of NO that are induced by SAH. We examine the effects of SAH on the function of the various NOS isoforms, with a particular focus on the pathological effects of NOS-2 and on the mechanisms responsible for its transcriptional upregulation. Finally, we review interventions to block NOS-2 upregulation or to counteract its effects, with an emphasis on the potential therapeutic strategies to improve outcomes in patients afflicted with SAH. There is still much to be learned regarding the apparently maladaptive response of NOS-2 and its harmful product NO in SAH. However, the available evidence points to crucial effects that, on balance, are adverse, making the NOS-2/NO/peroxynitrite axis an attractive therapeutic target in SAH.

  7. Up-regulation of the RhoA/Rho-kinase signaling pathway in corpus cavernosum from endothelial nitric-oxide synthase (NOS), but not neuronal NOS, null mice.

    PubMed

    Priviero, Fernanda B M; Jin, Li-Ming; Ying, Zhekang; Teixeira, Cleber E; Webb, R Clinton

    2010-04-01

    We tested the hypothesis that the basal release of nitric oxide (NO) from endothelial cells modulates contractile activity in the corpus cavernosum (CC) via inhibition of the RhoA/Rho-kinase signaling pathway. Cavernosal strips from wild-type (WT), endothelial nitric-oxide synthase knockout [eNOS(-/-)], and neuronal nitric-oxide synthase knockout [nNOS(-/-)] mice were mounted in myographs, and isometric force was recorded. mRNA and protein expression of key molecules in the RhoA/Rho-kinase pathway were analyzed by real-time polymerase chain reaction and Western blot, respectively. The cGMP levels were determined. The Rho-kinase inhibitors (R)-(+)-trans-N-(4-pyridyl)-4-(1-aminoethyl)-cyclohexanecarboxamide (Y-27632) and (S)-(+)-2-methyl-1-[(4-methyl-5-isoquinolinyl)sulfonyl] homopiperazine (H-1152) reduced cavernosal contractions evoked by phenylephrine or electrical field stimulation (EFS) in a concentration-dependent manner, although this inhibition was less effective in tissues from eNOS(-/-) mice. Y-27632 enhanced relaxations induced by sodium nitroprusside, EFS, and NO (administered as acidified NaNO2) without affecting the cGMP content of the cavernosal strips. This enhancement was less prominent in CC from eNOS(-/-). The protein expression of RhoA, Rho-guanine dissociation inhibitor, and Rho-kinase beta did not differ among the strains. However, in eNOS(-/-) CC, the protein expression of Rho-kinase alpha and both mRNA and protein expression of p115-Rho-associated guanine exchange factor (RhoGEF), PDZ-RhoGEF, and leukemia-associated RhoGEF were up-regulated. Phosphorylation of MYPT1 at Thr696 was higher in tissues from eNOS(-/-) mice. A high concentration of Y-27632 significantly enhanced NO release in CC stimulated by EFS. These results suggest a basal release of NO from endothelial cells, which inhibits contractions mediated by the RhoA/Rho-kinase pathway and modulates the expression of proteins related to this pathway in mouse CC. It indicates that

  8. Investigating the Role of NOS2 in Breast Cancer | Center for Cancer Research

    Cancer.gov

    Inducible nitric oxide synthase (NOS2) is often elevated in breast tumors that lack expression of the estrogen receptor (ER) and predicts a poor prognosis for patients with these tumors. However, it is unclear whether NOS2 directly contributes to ER-negative breast cancer aggressiveness or how NOS2 expression is controlled within the tumor microenvironment. To tease apart the regulatory pathways upstream and downstream of NOS2, David Wink, Jr., Ph.D., Senior Investigator in CCR’s Radiation Biology Branch, along with colleagues from CCR’s Pediatric Oncology Branch, Laboratory of Human Carcinogenesis, and Laboratory of Experimental Immunology and from the Prostate Cancer Institute in Ireland, carried out studies in cell culture and mouse models.

  9. SOD1 suppresses maternal hyperglycemia-increased iNOS expression and consequent nitrosative stress in diabetic embryopathy

    PubMed Central

    Weng, Hongbo; Li, Xuezheng; Reece, E. Albert; Yang, Peixin

    2012-01-01

    Objectives Hyperglycemia induces oxidative stress and increases inducible nitric oxide synthase (iNOS) expression. We hypothesized that oxidative stress is responsible for hyperglycemia-induced iNOS expression. Study Design iNOS-luciferase activities, nitrosylated protein, lipidperoxidation markers 4-HNE and MDA were determined in PYS-2 cells exposed to 5 mM glucose or high glucose (25 mM) with or without SOD1 (copper zinc superoxide dismutase 1) treatment. Levels of iNOS protein and mRNA, nitrosylated protein, and cleaved caspase-3 and -8 were assessed in wild-type embryos and SOD1 overexpressing embryos from non-diabetic and diabetic dams. Results SOD1 treatment diminished high glucose-induced oxidative stress, as evidenced by 4-HNE and MDA reductions, and it blocked high glucose-increased iNOS expression, iNOS-luciferase activities, and nitrosylated protein. in vivo SOD1 overexpression suppressed hyperglycemia-increased iNOS expression and nitrosylated protein, and it blocked caspase-3 and -8 cleavage. Conclusions We conclude that oxidative stress induces iNOS expression, nitrosative stress, and apoptosis in diabetic embryopathy. PMID:22425406

  10. SOD1 suppresses maternal hyperglycemia-increased iNOS expression and consequent nitrosative stress in diabetic embryopathy.

    PubMed

    Weng, Hongbo; Li, Xuezheng; Reece, E Albert; Yang, Peixin

    2012-05-01

    Hyperglycemia induces oxidative stress and increases inducible nitric oxide synthase (iNOS) expression. We hypothesized that oxidative stress is responsible for hyperglycemia-induced iNOS expression. iNOS-luciferase activities, nitrosylated protein, and lipid peroxidation markers 4-hydroxynonenal and malondialdehyde were determined in parietal yolk sac-2 cells exposed to 5 mmol/L glucose or high glucose (25 mmol/L) with or without copper zinc superoxide dismutase 1 (SOD1) treatment. Levels of iNOS protein and messenger RNA, nitrosylated protein, and cleaved caspase-3 and -8 were assessed in wild-type embryos and SOD1-overexpressing embryos from nondiabetic and diabetic dams. SOD1 treatment diminished high glucose-induced oxidative stress, as evidenced by 4-hydroxynonenal and malondialdehyde reductions, and it blocked high glucose-increased iNOS expression, iNOS-luciferase activities, and nitrosylated protein. In vivo SOD1 overexpression suppressed hyperglycemia-increased iNOS expression and nitrosylated protein, and it blocked caspase-3 and -8 cleavage. We conclude that oxidative stress induces iNOS expression, nitrosative stress, and apoptosis in diabetic embryopathy. Copyright © 2012 Mosby, Inc. All rights reserved.

  11. Students' understandings of nature of science and their arguments in the context of four socio-scientific issues

    NASA Astrophysics Data System (ADS)

    Khishfe, Rola; Alshaya, Fahad S.; BouJaoude, Saouma; Mansour, Nasser; Alrudiyan, Khalid I.

    2017-02-01

    The purpose of this study was to examine students understandings about nature of science (NOS) and their arguments in context of controversial socio-scientific issue (SSI). A total of 74 11th graders in six schools in Saudi Arabia participated in the study. The instrument used was a questionnaire consisting of four scenarios addressing SSI about global warming, genetically modified food, acid rain, and human cloning. The scenarios were followed by questions relating to argumentation and NOS. Quantitative and qualitative measures were employed to analyze the data related to participants understandings of three NOS aspects (subjective, tentative, and empirical) and their arguments components (argument, counterargument, and rebuttal). Results showed no significant correlations between argument components and the NOS aspects. On the other hand, qualitative data showed that participants who generated well-developed arguments across the four SSI also exhibited more informed understandings of the NOS aspects, especially for female participants. Further, the chi-square analyses did not show significant differences in participants arguments and NOS understandings across the four scenarios. Again, the qualitative data from questionnaires showed differences in participants responses to the different scenarios. The results were interpreted along contextual factors, emotional factors, and cultural factors. Implications for the teaching of NOS and arguments were discussed.

  12. Quantitative Analysis of Representations of Nature of Science in Nordic Upper Secondary School Textbooks Using Framework of Analysis Based on Philosophy of Chemistry

    NASA Astrophysics Data System (ADS)

    Vesterinen, Veli-Matti; Aksela, Maija; Lavonen, Jari

    2013-07-01

    The aim of this study was to assess how the different aspects of nature of science (NOS) were represented in Finnish and Swedish upper secondary school chemistry textbooks. The dimensions of NOS were analyzed from five popular chemistry textbook series. The study provides a quantitative method for analysis of representations of NOS in chemistry textbooks informed by domain-specific research on the philosophy of chemistry and chemical education. The selection of sections analyzed was based on the four themes of scientific literacy: knowledge of science, investigate nature of science, science as a way of thinking, and interaction of science, technology and society. For the second round of analysis the theme of science as a way of thinking was chosen for a closer inspection. The units of analysis in this theme were analyzed using seven domain specific dimensions of NOS: tentative, empirical, model-based, inferential, technological products, instrumentation, and social and societal dimensions. Based on the inter-rater agreement, the procedure and frameworks of analysis presented in this study was a reliable way of assessing the emphasis given to the domain specific aspects of NOS. All textbooks have little emphasis on the theme science as a way of thinking on a whole. In line with the differences of curricula, Swedish textbooks emphasize the tentative dimension of NOS more than Finnish textbooks. To provide teachers with a sufficiently wide variety of examples to discuss the different dimensions of NOS changes to the national core curricula are needed. Although changing the emphasis of the curricula would be the most obvious way to affect the emphasis of the textbooks, other efforts such as pre- and in-service courses for developing teachers understanding of NOS and pedagogic approaches for NOS instruction to their classroom practice might also be needed.

  13. Challenges and Changes: Developing Teachers' and Initial Teacher Education Students' Understandings of the Nature of Science

    NASA Astrophysics Data System (ADS)

    Ward, Gillian; Haigh, Mavis

    2017-12-01

    Teachers need an understanding of the nature of science (NOS) to enable them to incorporate NOS into their teaching of science. The current study examines the usefulness of a strategy for challenging or changing teachers' understandings of NOS. The teachers who participated in this study were 10 initial teacher education chemistry students and six experienced teachers from secondary and primary schools who were introduced to an explicit and reflective activity, a dramatic reading about a historical scientific development. Concept maps were used before and after the activity to assess teachers' knowledge of NOS. The participants also took part in a focus group interview to establish whether they perceived the activity as useful in developing their own understanding of NOS. Initial analysis led us to ask another group, comprising seven initial teacher education chemistry students, to take part in a modified study. These participants not only completed the same tasks as the previous participants but also completed a written reflection commenting on whether the activity and focus group discussion enhanced their understanding of NOS. Both Lederman et al.'s (Journal of Research in Science Teaching, 39(6), 497-521, 2002) concepts of NOS and notions of "naive" and "informed" understandings of NOS and Hay's (Studies in Higher Education, 32(1), 39-57, 2007) notions of "surface" and "deep" learning were used as frameworks to examine the participants' specific understandings of NOS and the depth of their learning. The ways in which participants' understandings of NOS were broadened or changed by taking part in the dramatic reading are presented. The impact of the data-gathering tools on the participants' professional learning is also discussed.

  14. The effectiveness of conceptual change texts and concept clipboards in learning the nature of science

    NASA Astrophysics Data System (ADS)

    Çil, Emine; Çepni, Salih

    2016-01-01

    Background: One of the most important goals of science education is to enable students to understand the nature of science (NOS). However, generally regular science teaching in classrooms does not help students improve informed NOS views. Purpose: This study investigated the influence of an explicit reflective conceptual change approach compared with an explicit reflective inquiry-oriented approach on seventh graders' understanding of NOS. Sample: The research was conducted with seventh grade students. A total of 44 students participated in the study. Design and method: The study was an interpretive study because this study focused on the meanings that students attach to target aspects of NOS. Participants were divided into two groups, each consisting of 22 students. One of the groups learned NOS with an explicit reflective conceptual change approach. The requirements of conceptual change were provided through the use of conceptual change texts and concept cartoons. The other group learned NOS with an explicit reflective inquiry-oriented approach. The data were collected through open-ended questionnaires and semi-structured interviews. These instruments were employed in a pre-test, a post-test and a delayed test. Students' views of the aspects of NOS were categorized as naive, transitional and informed. Results: The result of this study indicated that before receiving instruction, most of the participants had transitional views of the tentative, empirical and imaginative and creative aspects of the NOS, and they had naive understandings of the distinction between observation and inference. The instruction in the experimental group led to a 60% - a 25% increase in the number of students who possessed an informed understanding of the tentative, empirical, creative and observation and inference aspect of the NOS. The instruction in the control group led to a 30% - a 15% increase in the informed NOS views. Conclusion: The explicit reflective conceptual change approach

  15. Focusing on the Classical or Contemporary? Chinese Science Teacher Educators' Conceptions of Nature of Science Content to Be Taught to Pre-Service Science Teachers

    ERIC Educational Resources Information Center

    Wan, Zhi Hong; Wong, Siu Ling; Wei, Bing; Zhan, Ying

    2013-01-01

    Drawing from the phenomenographic perspective, an exploratory study investigated Chinese teacher educators' conceptions of teaching Nature of Science (NOS) to pre-service science teachers through semi-structured interviews. Five key dimensions emerged from the data. This paper focuses on the dimension, "NOS content to be taught to pre-service…

  16. Fluorination Effects on NOS Inhibitory Activity of Pyrazoles Related to Curcumin.

    PubMed

    Nieto, Carla I; Cabildo, María Pilar; Cornago, María Pilar; Sanz, Dionisia; Claramunt, Rosa M; Torralba, María Carmen; Torres, María Rosario; Elguero, José; García, José A; López, Ana; Acuña-Castroviejo, Darío

    2015-08-28

    A series of new (E)-3(5)-[β-(aryl)-ethenyl]-5(3)-phenyl-1H-pyrazoles bearing fluorine atoms at different positions of the aryl group have been synthesized starting from the corresponding β-diketones. All compounds have been characterized by elemental analysis, DSC as well as NMR (¹H, (13)C, (19)F and (15)N) spectroscopy in solution and in solid state. Three structures have been solved by X-ray diffraction analysis, confirming the tautomeric forms detected by solid state NMR. The in vitro study of their inhibitory potency and selectivity on the activity of nNOS and eNOS (calcium-calmodulin dependent) as well as iNOS (calcium-calmodulin independent) isoenzymes is presented. A qualitative structure-activity analysis allowed the establishment of a correlation between the presence/ absence of different substituents with the inhibition data proving that fluorine groups enhance the biological activity. (E)-3(5)-[β-(3-Fluoro-4-hydroxyphenyl)-ethenyl]-5(3)-phenyl-1H-pyrazole (13), is the best inhibitor of iNOS, being also more selective towards the other two isoforms.

  17. The Context of Demarcation in Nature of Science Teaching: The Case of Astrology

    NASA Astrophysics Data System (ADS)

    Turgut, Halil

    2011-05-01

    The aim of developing students' understanding of the nature of science [NOS] has been considered an important aspect of science education. However, the results of previous research indicate that students of various ages and even teachers possess both inaccurate and inappropriate views of the NOS. Such a failure has been explained by the view that perceptions about the NOS are well assimilated into mental structures and resistant to change. Further, the popularization of pseudoscience by the media and the assimilation of pseudoscience into previously established scientific fields have been presented as possible reasons for erroneous popular perceptions of science. Any teaching intervention designed to teach the NOS should first provoke individuals to expose their current ideas in order to provide them the chance to revise or replace these conceptual frameworks. Based on these assumptions, the aim of this study was to determine whether a teaching context based on the issue of demarcation would provide a suitable opportunity for exposing and further developing the NOS understandings of individuals enrolled in a teacher education course. Results indicate that a learning intervention based on the issue of demarcation of science from pseudoscience (in the specific case of astrology) proved an effective instructional strategy, which a majority of teacher candidates claimed to plan to use in their future teachings.

  18. Professional Journals as a Source of PCK for Teaching Nature of Science: An Examination of Articles Published in The Science Teacher (TST) (an NSTA Journal), 1995-2010

    NASA Astrophysics Data System (ADS)

    Aydın, Sevgi; Demirdöğen, Betül; Muslu, Nilay; Hanuscin, Deborah L.

    2013-10-01

    A number of science education policy documents recommend that students develop an understanding of the enterprise of science and the nature of science (NOS). Despite this emphasis, there is still a gap between policy and practice. Teacher professional literature provides one potential venue for bridging this gap, by providing “activities that work” (Appleton in elementary science teacher education: International perspectives on contemporary issues and practice. Lawrence Erlbaum Associates, Mahwah, NJ, 2006) that can scaffold teachers’ developing pedagogical content knowledge (PCK) for teaching NOS. We analyzed articles published in the NSTA journal The Science Teacher (1995-2010) in terms of the degree to which they provide appropriate model activities and specific information that can support the development of teachers’ PCK for teaching NOS. Our analysis revealed a diversity of NOS aspects addressed by the authors and a wide range of variation in the percent of articles focused on each aspect. Additionally, we found that few articles provided robust information related to all the component knowledge bases of PCK for NOS. In particular, within the extant practitioner literature, there are few models for teaching the aspects of NOS, such as the function and nature of scientific theory. Furthermore, though articles provided information relevant to informing teachers’ knowledge of instructional strategies for NOS, relevant information to inform teachers’ knowledge of assessment in this regard was lacking. We provide recommendations for ways in which the practitioner literature may support teachers’ teaching of NOS through more robust attention to the types of knowledge research indicates are needed in order to teaching NOS effectively.

  19. Enhanced XOR activity in eNOS-deficient mice: Effects on the nitrate-nitrite-NO pathway and ROS homeostasis.

    PubMed

    Peleli, Maria; Zollbrecht, Christa; Montenegro, Marcelo F; Hezel, Michael; Zhong, Jianghong; Persson, Erik G; Holmdahl, Rikard; Weitzberg, Eddie; Lundberg, Jon O; Carlström, Mattias

    2016-10-01

    Xanthine oxidoreductase (XOR) is generally known as the final enzyme in purine metabolism and as a source of reactive oxygen species (ROS). In addition, this enzyme has been suggested to mediate nitric oxide (NO) formation via reduction of inorganic nitrate and nitrite. This NO synthase (NOS)-independent pathway for NO generation is of particular importance during certain conditions when NO bioavailability is diminished due to reduced activity of endothelial NOS (eNOS) or increased oxidative stress, including aging and cardiovascular disease. The exact interplay between NOS- and XOR-derived NO generation is not fully elucidated yet. The aim of the present study was to investigate if eNOS deficiency is associated with changes in XOR expression and activity and the possible impact on nitrite, NO and ROS homeostasis. Plasma levels of nitrate and nitrite were similar between eNOS deficient (eNOS -/- ) and wildtype (wt) mice. XOR activity was upregulated in eNOS -/- compared with wt, but not in nNOS -/- , iNOS -/- or wt mice treated with the non-selective NOS inhibitor L-NAME. Following an acute dose of nitrate, plasma nitrite increased more in eNOS -/- compared with wt, and this augmented response was abolished by the selective XOR inhibitor febuxostat. Livers from eNOS -/- displayed higher nitrite reducing capacity compared with wt, and this effect was attenuated by febuxostat. Dietary supplementation with nitrate increased XOR expression and activity, but concomitantly reduced superoxide generation. The latter effect was also seen in vitro after nitrite administration. Treatment with febuxostat elevated blood pressure in eNOS -/- , but not in wt mice. A high dose of dietary nitrate reduced blood pressure in naïve eNOS -/- mice, and again this effect was abolished by febuxostat. In conclusion, eNOS deficiency is associated with an upregulation of XOR facilitating the nitrate-nitrite-NO pathway and decreasing the generation of ROS. This interplay between XOR and eNOS

  20. NOS-based biopolymers; towards novel thromboresistant NO-release materials

    NASA Astrophysics Data System (ADS)

    Abou Diwan, Charbel

    Nitric Oxide releasing biopolymers have the potential to prolong vascular graft and stent potency without adverse systemic vasodilation. It was reported in literature that eNOS-overexpressing endothelial cell seeding of synthetic small diameter vascular grafts decreased human platelet aggregation by 46% and bovine aortic smooth muscle cell proliferation by 67.2% in vitro. We hypothesized that incorporating the enzyme nitric oxide synthase (NOS) in biocompatible polymeric matrix will provide a source of NO that utilizes endogenous compounds to maintain an unlimited supply of NO. To test this hypothesis, we have incorporated the enzyme nitric oxide synthase into a polyethyleneimine film using a layer-by-layer electrostatic deposition. This approach will provide a source of NO that utilizes endogenous compounds available in the blood matrix to maintain a constant supply of NO at the blood/device interface. When coated onto the surface of various blood-contacting implantable medical devices, it will provide NO fluxes at levels equal or greater than the normal endothelial cells, and for extended time periods. This configuration will help solve the issues of both thrombosis and stenosis that occur as side effects for several types of biomedical implants. Our results indicate a proof of principle of a new approach for making antithrombotic coatings for medical devices and implants based on NO release. We have demonstrated that NOS-based polymetric films successfully generate NO under physiologic conditions at small levels equal to and higher than those observed for endothelial cells. The level of NO release can be fine-tuned through varying the number of NOS layers in the film buildup. We have shown that NO fluxes from our NOS-based PEI films are sustained for prolonged periods of time, which has the potential of producing efficient, short and long-term, antithrombotic coatings for medical devices and blood-contacting tools such as stents and catheters. We also show that

  1. Changes in Pre-Service Science Teachers' Understandings After Being Involved in Explicit Nature of Science and Socioscientific Argumentation Processes

    ERIC Educational Resources Information Center

    Kutluca, A. Y.; Aydin, A.

    2017-01-01

    The study explored the changes in pre-service science teachers' understanding of the nature of science and their opinions about the nature of science, science teaching and argumentation after their participation in explicit nature of science (NOS) and socioscientific argumentation processes. The participants were 56 third-grade pre-service science…

  2. Advanced Science Students' Understanding on Nature of Science in Turkey

    ERIC Educational Resources Information Center

    Köksal, Mustafa Serdar; Sormunen, Kari

    2014-01-01

    Nature of science (NOS), as an aspect of informed decision making about science related issues in daily life, is frequently emphasised when reform and the curriculum are in question. When reflecting on studies done on the subject, it comes apparent that the majority of them comprise of determination or assessment studies conducted with traditional…

  3. Nitrous Oxide Reductase (nosZ) Gene Fragments Differ between Native and Cultivated Michigan Soils

    PubMed Central

    Stres, Blaž; Mahne, Ivan; Avguštin, Gorazd; Tiedje, James M.

    2004-01-01

    The effect of standard agricultural management on the genetic heterogeneity of nitrous oxide reductase (nosZ) fragments from denitrifying prokaryotes in native and cultivated soil was explored. Thirty-six soil cores were composited from each of the two soil management conditions. nosZ gene fragments were amplified from triplicate samples, and PCR products were cloned and screened by restriction fragment length polymorphism (RFLP). The total nosZ RFLP profiles increased in similarity with soil sample size until triplicate 3-g samples produced visually identical RFLP profiles for each treatment. Large differences in total nosZ profiles were observed between the native and cultivated soils. The fragments representing major groups of clones encountered at least twice and four randomly selected clones with unique RFLP patterns were sequenced to verify nosZ identity. The sequence diversity of nosZ clones from the cultivated field was higher, and only eight patterns were found in clone libraries from both soils among the 182 distinct nosZ RFLP patterns identified from the two soils. A group of clones that comprised 32% of all clones dominated the gene library of native soil, whereas many minor groups were observed in the gene library of cultivated soil. The 95% confidence intervals of the Chao1 nonparametric richness estimator for nosZ RFLP data did not overlap, indicating that the levels of species richness are significantly different in the two soils, the cultivated soil having higher diversity. Phylogenetic analysis of deduced amino acid sequences grouped the majority of nosZ clones into an interleaved Michigan soil cluster whose cultured members are α-Proteobacteria. Only four nosZ sequences from cultivated soil and one from the native soil were related to sequences found in γ-Proteobacteria. Sequences from the native field formed a distinct, closely related cluster (Dmean = 0.16) containing 91.6% of the native clones. Clones from the cultivated field were more

  4. De Novo Lipogenesis Maintains Vascular Homeostasis through Endothelial Nitric-oxide Synthase (eNOS) Palmitoylation*♦

    PubMed Central

    Wei, Xiaochao; Schneider, Jochen G.; Shenouda, Sherene M.; Lee, Ada; Towler, Dwight A.; Chakravarthy, Manu V.; Vita, Joseph A.; Semenkovich, Clay F.

    2011-01-01

    Endothelial dysfunction leads to lethal vascular complications in diabetes and related metabolic disorders. Here, we demonstrate that de novo lipogenesis, an insulin-dependent process driven by the multifunctional enzyme fatty-acid synthase (FAS), maintains endothelial function by targeting endothelial nitric-oxide synthase (eNOS) to the plasma membrane. In mice with endothelial inactivation of FAS (FASTie mice), eNOS membrane content and activity were decreased. eNOS and FAS were physically associated; eNOS palmitoylation was decreased in FAS-deficient cells, and incorporation of labeled carbon into eNOS-associated palmitate was FAS-dependent. FASTie mice manifested a proinflammatory state reflected as increases in vascular permeability, endothelial inflammatory markers, leukocyte migration, and susceptibility to LPS-induced death that was reversed with an NO donor. FAS-deficient endothelial cells showed deficient migratory capacity, and angiogenesis was decreased in FASTie mice subjected to hindlimb ischemia. Insulin induced FAS in endothelial cells freshly isolated from humans, and eNOS palmitoylation was decreased in mice with insulin-deficient or insulin-resistant diabetes. Thus, disrupting eNOS bioavailability through impaired lipogenesis identifies a novel mechanism coordinating nutritional status and tissue repair that may contribute to diabetic vascular disease. PMID:21098489

  5. PGC-1α dictates endothelial function through regulation of eNOS expression

    PubMed Central

    Craige, Siobhan M.; Kröller-Schön, Swenja; Li, Chunying; Kant, Shashi; Cai, Shenghe; Chen, Kai; Contractor, Mayur M.; Pei, Yongmei; Schulz, Eberhard; Keaney, John F.

    2016-01-01

    Endothelial dysfunction is a characteristic of many vascular related diseases such as hypertension. Peroxisome proliferator activated receptor gamma, coactivator 1α (PGC-1α) is a unique stress sensor that largely acts to promote adaptive responses. Therefore, we sought to define the role of endothelial PGC-1α in vascular function using mice with endothelial specific loss of function (PGC-1α EC KO) and endothelial specific gain of function (PGC-1α EC TG). Here we report that endothelial PGC-1α is suppressed in angiotensin-II (ATII)-induced hypertension. Deletion of endothelial PGC-1α sensitized mice to endothelial dysfunction and hypertension in response to ATII, whereas PGC-1α EC TG mice were protected. Mechanistically, PGC-1α promotes eNOS expression and activity, which is necessary for protection from ATII-induced dysfunction as mice either treated with an eNOS inhibitor (LNAME) or lacking eNOS were no longer responsive to transgenic endothelial PGC-1α expression. Finally, we determined that the orphan nuclear receptor, estrogen related receptor α (ERRα) is required to coordinate the PGC-1α -induced eNOS expression. In conclusion, endothelial PGC-1α expression protects from vascular dysfunction by promoting NO• bioactivity through ERRα induced expression of eNOS. PMID:27910955

  6. Thai Pre-Service Science Teachers' Conceptions of the Nature of Science

    ERIC Educational Resources Information Center

    Buaraphan, Khajornsak; Sung-ong, Sunun

    2009-01-01

    The conceptions of the nature of science (NOS), particularly scientific knowledge, scientific method, scientists' work, and scientific enterprise, of 113 Thai pre-service science teachers were was captured by the Myths of Science Questionnaire (MOSQ) in the first semester of the 2008 academic year. The data was quantitatively and qualitatively…

  7. Teaching Nature of Science within a Controversial Topic: Integrated versus Nonintegrated

    ERIC Educational Resources Information Center

    Khishfe, Rola; Lederman, Norman

    2006-01-01

    This study investigated the influence of two different explicit instructional approaches in promoting more informed understandings of nature of science (NOS) among students. Participants, a total of 42 students, comprised two groups in two intact sections of ninth grade. Participants in the two groups were taught environmental science by their…

  8. Assessing the Nature of Science Views of Singaporean Pre-Service Teachers

    ERIC Educational Resources Information Center

    Thye, Tan Lip; Kwen, Boo Hong

    2004-01-01

    Despite the many developments in the teaching of science, an aspect that continues to be neglected appears to be the character and nature of science (NOS). This is becoming especially important in the light of recent developments in pedagogy, as, for example, more teachers adopt constructivist methodologies and computing technology enables…

  9. Explicit Reflective Nature of Science Instruction: Evolution, Intelligent Design, and Umbrellaology

    ERIC Educational Resources Information Center

    Scharmann, Lawrence C.; Smith, Mike U.; James, Mark C.; Jensen, Murray

    2005-01-01

    The investigators sought to design an instructional unit to enhance an understanding of the nature of science (NOS) by taking into account both instructional best practices and suggestions made by noted science philosopher Thomas Kuhn. Preservice secondary science teachers enrolled in a course, "Laboratory Techniques in the Teaching of Science,"…

  10. Consistency of the Health of the Nation Outcome Scales (HoNOS) at inpatient-to-community transition.

    PubMed

    Luo, Wei; Harvey, Richard; Tran, Truyen; Phung, Dinh; Venkatesh, Svetha; Connor, Jason P

    2016-04-27

    The Health of the Nation Outcome Scales (HoNOS) are mandated outcome-measures in many mental-health jurisdictions. When HoNOS are used in different care settings, it is important to assess if setting specific bias exists. This article examines the consistency of HoNOS in a sample of psychiatric patients transitioned from acute inpatient care and community centres. A regional mental health service with both acute and community facilities. 111 psychiatric patients were transferred from inpatient care to community care from 2012 to 2014. Their HoNOS scores were extracted from a clinical database; Each inpatient-discharge assessment was followed by a community-intake assessment, with the median period between assessments being 4 days (range 0-14). Assessor experience and professional background were recorded. The difference of HoNOS at inpatient-discharge and community-intake were assessed with Pearson correlation, Cohen's κ and effect size. Inpatient-discharge HoNOS was on average lower than community-intake HoNOS. The average HoNOS was 8.05 at discharge (median 7, range 1-22), and 12.16 at intake (median 12, range 1-25), an average increase of 4.11 (SD 6.97). Pearson correlation between two total scores was 0.073 (95% CI -0.095 to 0.238) and Cohen's κ was 0.02 (95% CI -0.02 to 0.06). Differences did not appear to depend on assessor experience or professional background. Systematic change in the HoNOS occurs at inpatient-to-community transition. Some caution should be exercised in making direct comparisons between inpatient HoNOS and community HoNOS scores. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  11. Aspirin prevents TNF-α-induced endothelial cell dysfunction by regulating the NF-κB-dependent miR-155/eNOS pathway: Role of a miR-155/eNOS axis in preeclampsia.

    PubMed

    Kim, Joohwan; Lee, Kyu-Sun; Kim, Ji-Hee; Lee, Dong-Keon; Park, Minsik; Choi, Seunghwan; Park, Wonjin; Kim, Suji; Choi, Yoon Kyung; Hwang, Jong Yun; Choe, Jongseon; Won, Moo-Ho; Jeoung, Dooil; Lee, Hansoo; Ryoo, Sungwoo; Ha, Kwon-Soo; Kwon, Young-Guen; Kim, Young-Myeong

    2017-03-01

    Preeclampsia is an inflammatory disease with endothelial cell dysfunction that occurs via decreased endothelial nitric oxide synthase/nitric oxide (eNOS/NO) activity. Aspirin reduces the incidence of hypertensive pregnancy complications. However, the underlying mechanism has not been clearly explained. Here, we found that tumor necrosis factor (TNF)-α, microRNA (miR)-155, and eNOS levels as well as endothelial redox phenotype were differentially regulated in preeclamptic patients, implying the involvement of TNF-α- and redox signal-mediated miR-155 biogenesis and eNOS downregulation in the pathogenesis of preeclampsia. Aspirin prevented the TNF-α-mediated increase in miR-155 biogenesis and decreases in eNOS expression and NO/cGMP production in cultured human umbilical vein endothelial cells (HUVECs). Similar effects of aspirin were also observed in HUVECs treated with H 2 O 2 . The preventive effects of aspirin was associated with the inhibition of nuclear factor-κB (NF-κB)-dependent MIR155HG (miR-155 host gene) expression. Aspirin recovered the TNF-α-mediated decrease in wild-type, but not mutant, eNOS 3'-untranslated region reporter activity, whose effect was blocked by miR-155 mimic. Moreover, aspirin prevented TNF-α-mediated endothelial cell dysfunction associated with impaired vasorelaxation, angiogenesis, and trophoblast invasion, and the preventive effects were blocked by miR-155 mimic or an eNOS inhibitor. Aspirin rescued TNF-α-mediated eNOS downregulation coupled with endothelial dysfunction by inhibiting NF-κB-dependent transcriptional miR-155 biogenesis. Thus, the redox-sensitive NF-κB/miR-155/eNOS axis may be crucial in the pathogenesis of vascular disorders including preeclampsia. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Developing a Professional Identity as an Elementary Teacher of Nature of Science: A self-study of becoming an elementary teacher

    NASA Astrophysics Data System (ADS)

    Akerson, Valarie L.; Pongsanon, Khemmawadee; Weiland, Ingrid S.; Nargund-Joshi, Vanashri

    2014-08-01

    This study explores the development of professional identity as a teacher of nature of science (NOS). Our research question was 'How can a teacher develop a professional identity as an elementary teacher of NOS?' Through a researcher log, videotaped lessons, and collection of student work, we were able to track efforts in teaching NOS as part of regular classroom practice. A team of four researchers interpreted the data through the Beijaard et al. professional identity framework and found that it was not as simple and straightforward to teach NOS as we predicted. Development of professional identity as a teacher of NOS was influenced by contextual factors such as students, administration, and time, as well as personal struggles that were fraught with emotion. Development took place through an interpretation and reinterpretation of self through external factors and others' perceptions, as well as the influence of sub-identities.

  13. Endothelial NOS-deficient mice reveal dual roles for nitric oxide during experimental autoimmune encephalomyelitis.

    PubMed

    Wu, Muzhou; Tsirka, Stella E

    2009-08-15

    Multiple sclerosis (MS) is a demyelinating autoimmune disease characterized by infiltration of T cells into the central nervous system (CNS) after compromise of the blood-brain barrier. A model used to mimic the disease in mice is experimental autoimmune encephalomyelitis (EAE). In this report, we examine the clinical and histopathological course of EAE in eNOS-deficient (eNOS-/-) mice to determine the role of nitric oxide (NO) derived from this enzyme in the disease progression. We find that eNOS-/- mice exhibit a delayed onset of EAE that correlates with delayed BBB breakdown, thus suggesting that NO production by eNOS underlies the T cell infiltration into the CNS. However, the eNOS-/- mice also eventually exhibit more severe EAE and delayed recovery, indicating that NO undertakes dual roles in MS/EAE, one proinflammatory that triggers disease onset, and the other neuroprotective that promotes recovery from disease exacerbation events.

  14. Teaching "With" and "About" Nature of Science, and Science Teacher Knowledge Domains

    ERIC Educational Resources Information Center

    Abd-El-Khalick, Fouad

    2013-01-01

    The ubiquitous goals of helping precollege students develop informed conceptions of nature of science (NOS) and experience inquiry learning environments that progressively approximate authentic scientific practice have been long-standing and central aims of science education reforms around the globe. However, the realization of these goals…

  15. Control of food intake and energy expenditure by Nos1 neurons of the paraventricular hypothalamus.

    PubMed

    Sutton, Amy K; Pei, Hongjuan; Burnett, Korri H; Myers, Martin G; Rhodes, Christopher J; Olson, David P

    2014-11-12

    The paraventricular nucleus of the hypothalamus (PVH) contains a heterogeneous cluster of Sim1-expressing cell types that comprise a major autonomic output nucleus and play critical roles in the control of food intake and energy homeostasis. The roles of specific PVH neuronal subtypes in energy balance have yet to be defined, however. The PVH contains nitric oxide synthase-1 (Nos1)-expressing (Nos1(PVH)) neurons of unknown function; these represent a subset of the larger population of Sim1-expressing PVH (Sim1(PVH)) neurons. To determine the role of Nos1(PVH) neurons in energy balance, we used Cre-dependent viral vectors to both map their efferent projections and test their functional output in mice. Here we show that Nos1(PVH) neurons project to hindbrain and spinal cord regions important for food intake and energy expenditure control. Moreover, pharmacogenetic activation of Nos1(PVH) neurons suppresses feeding to a similar extent as Sim1(PVH) neurons, and increases energy expenditure and activity. Furthermore, we found that oxytocin-expressing PVH neurons (OXT(PVH)) are a subset of Nos1(PVH) neurons. OXT(PVH) cells project to preganglionic, sympathetic neurons in the thoracic spinal cord and increase energy expenditure upon activation, though not to the same extent as Nos1(PVH) neurons; their activation fails to alter feeding, however. Thus, Nos1(PVH) neurons promote negative energy balance through changes in feeding and energy expenditure, whereas OXT(PVH) neurons regulate energy expenditure alone, suggesting a crucial role for non-OXT Nos1(PVH) neurons in feeding regulation. Copyright © 2014 the authors 0270-6474/14/3415306-13$15.00/0.

  16. Constitutive NOS uncoupling and NADPH oxidase upregulation in the penis of type 2 diabetic men with erectile dysfunction

    PubMed Central

    Musicki, Biljana; Burnett, Arthur L.

    2016-01-01

    Erectile dysfunction (ED) associated with type 2 diabetes mellitus (T2DM) involves dysfunctional nitric oxide (NO) signaling and increased oxidative stress in the penis. However, the mechanisms of endothelial NO synthase (eNOS) and neuronal NO synthase (nNOS) dysregulation, and the sources of oxidative stress, are not well defined, particularly at the human level. The objective of this study was to define whether uncoupled eNOS and nNOS, and NADPH oxidase upregulation, contribute to the pathogenesis of ED in T2DM men. Penile erectile tissue was obtained from 9 T2DM patients with ED who underwent penile prosthesis surgery for ED, and from 6 control patients without T2DM or ED who underwent penectomy for penile cancer. The dimer-to-monomer protein expression ratio, an indicator of uncoupling for both eNOS and nNOS, total protein expressions of eNOS and nNOS, as well as protein expressions of NADPH oxidase catalytic subunit gp91phox (an enzymatic source of oxidative stress) and 4-hydroxy-2-nonenal [4-HNE] and nitrotyrosine (markers of oxidative stress) were measured by Western blot in this tissue. In the erectile tissue of T2DM men, eNOS and nNOS uncoupling and protein expressions of NADPH oxidase subunit gp91phox, 4-HNE- and nitrotyrosine-modified proteins were significantly (p<0.05) increased compared to control values. Total eNOS and nNOS protein expressions were not significantly different between the groups. In conclusion, mechanisms of T2DM-associated ED in the human penis may involve uncoupled eNOS and nNOS and NADPH oxidase upregulation. Our description of molecular factors contributing to the pathogenesis of T2DM-associated ED at the human level is relevant for advancing clinically therapeutic approaches to restore erectile function in T2DM patients. PMID:28076881

  17. A review and update of the Health of the Nation Outcome Scales (HoNOS).

    PubMed

    James, Mick; Painter, Jon; Buckingham, Bill; Stewart, Malcolm W

    2018-04-01

    Aims and method The Health of the Nation Outcome Scales (HoNOS) and its older adults' version (HoNOS 65+) have been used widely for 20 years, but their glossaries have not been revised to reflect clinicians' experiences or changes in service delivery. The Royal College of Psychiatrists convened an international advisory board, with UK, Australian and New Zealand expertise, to identify desirable amendments. The aim was to improve rater experience by removing ambiguity and inconsistency in the glossary rather than more radical revision. Changes proposed to the HoNOS are reported. HoNOS 65+ changes will be reported separately. Based on the views and experience of the countries involved, a series of amendments were identified. Clinical implications While effective clinician training remains critically important, these revisions aim to improve intra- and interrater reliability and improve validity. Next steps will depend on feedback from HoNOS users. Reliability and validity testing will depend on funding. Declaration of interest None.

  18. Emphasizing the History of Genetics in an Explicit and Reflective Approach to Teaching the Nature of Science

    NASA Astrophysics Data System (ADS)

    Williams, Cody Tyler; Rudge, David Wÿss

    2016-05-01

    Science education researchers have long advocated the central role of the nature of science (NOS) for our understanding of scientific literacy. NOS is often interpreted narrowly to refer to a host of epistemological issues associated with the process of science and the limitations of scientific knowledge. Despite its importance, practitioners and researchers alike acknowledge that students have difficulty learning NOS and that this in part reflects how difficult it is to teach. One particularly promising method for teaching NOS involves an explicit and reflective approach using the history of science. The purpose of this study was to determine the influence of a historically based genetics unit on undergraduates' understanding of NOS. The three-class unit developed for this study introduces students to Mendelian genetics using the story of Gregor Mendel's work. NOS learning objectives were emphasized through discussion questions and investigations. The unit was administered to undergraduates in an introductory biology course for pre-service elementary teachers. The influence of the unit was determined by students' responses to the SUSSI instrument, which was administered pre- and post-intervention. In addition, semi-structured interviews were conducted that focused on changes in students' responses from pre- to post-test. Data collected indicated that students showed improved NOS understanding related to observations, inferences, and the influence of culture on science.

  19. Science Teachers' Thinking About the Nature of Science: A New Methodological Approach to Its Assessment

    NASA Astrophysics Data System (ADS)

    Vázquez-Alonso, Ángel; García-Carmona, Antonio; Manassero-Mas, María Antonia; Bennàssar-Roig, Antoni

    2013-04-01

    This paper describes Spanish science teachers' thinking about issues concerning the nature of science (NOS) and the relationships connecting science, technology, and society (STS). The sample consisted of 774 in-service and pre-service teachers. The participants responded to a selection of items from the Questionnaire of Opinions on Science, Technology & Society in a multiple response model. These data were processed to generate the invariant indices that are used as the bases for subsequent quantitative and qualitative analyses. The overall results reflect moderately informed conceptions, and a detailed analysis by items, categories, and positions reveals a range of positive and negative conceptions about the topics of NOS dealt with in the questionnaire items. The implications of the findings for teaching and teacher training on the themes of NOS are discussed.

  20. Conceptions of the Nature of Science and Technology: a Study with Children and Youths in a Non-Formal Science and Technology Education Setting

    NASA Astrophysics Data System (ADS)

    Rocha Fernandes, Geraldo W.; Rodrigues, António M.; Ferreira, Carlos Alberto

    2017-05-01

    This study investigated some of the aspects that characterise the understanding of the Nature of Science (NOS) and Nature of Technology (NOT) of 20 children and youths from different countries who perform scientific and technological activities in a non-formal teaching and learning setting. Data were collected using a questionnaire and semistructured interviews. A categorical instrument was developed to analyse the participants' conceptions of the following subjects: (1) the role of the scientist, (2) NOS and (3) NOT. The results suggest that the participants had naïve conceptions of NOS that are marked by empirical and technical-instrumental views. They characterised NOT primarily as an instrumental apparatus, an application of knowledge and something important that is part of their lives. They exhibited a stereotypical understanding of the role of the scientist (development of methods, demonstration of facts, relationship with technological devices, etc.).

  1. How to Use Historical Approach to Teach Nature of Science in Chemistry Education?

    ERIC Educational Resources Information Center

    Tolvanen, Simo; Jansson, Jan; Vesterinen, Veli-Matti; Aksela, Maija

    2014-01-01

    Successful implementation of historical approach to teach nature of science (NOS) requires suitable curriculum material. Several research and development projects have produced lesson plans for science teachers. 25 lesson plans from four different projects involved in creating curriculum material utilizing historical approach in chemistry…

  2. Student conceptualizations of the nature of science in response to a socioscientific issue

    NASA Astrophysics Data System (ADS)

    Sadler, Troy D.; Chambers, William F.; Zeidler, Dana L.

    2004-04-01

    This study investigates student conceptualizations of the nature of science (NOS) and how students interpret and evaluate conflicting evidence regarding a socioscientific issue. Eighty-four high school students participated in the study by reading contradictory reports about the status of global warming and responding to questions designed to elicit ideas pertinent to the research goals. A subsample of 30 students was interviewed in order to triangulate data from the written responses. Data were analyzed using a qualitative methodological approach. The participants displayed a range of views on three distinct aspects of NOS: empiricism, tentativeness, and social embeddedness. Findings indicate that interpretation and evaluation of conflicting evidence in a socioscientific context is influenced by a variety of factors related to NOS such as data interpretation and social interactions including individuals' own articulation of personal beliefs and scientific knowledge. Implications for science teaching and learning are discussed.

  3. The Akt1-eNOS axis illustrates the specificity of kinase-substrate relationships in vivo.

    PubMed

    Schleicher, Michael; Yu, Jun; Murata, Takahisa; Derakhshan, Berhad; Atochin, Dimitriy; Qian, Li; Kashiwagi, Satoshi; Di Lorenzo, Annarita; Harrison, Kenneth D; Huang, Paul L; Sessa, William C

    2009-08-04

    Akt1 is critical for many in vivo functions; however, the cell-specific substrates responsible remain to be defined. Here, we examine the importance of endothelial nitric oxide synthase (eNOS) as an Akt1 substrate by generating Akt1-deficient mice (Akt1(-/-) mice) carrying knock-in mutations (serine to aspartate or serine to alanine substitutions) of the critical Akt1 phosphorylation site on eNOS (serine 1176) that render the enzyme "constitutively active" or "less active." The eNOS mutations did not influence several phenotypes in Akt1(-/-) mice; however, the defective postnatal angiogenesis characteristic of Akt1(-/-) mice was rescued by crossing the Akt1(-/-) mice with mice carrying the constitutively active form of eNOS, but not by crossing with mice carrying the less active eNOS mutant. This genetic rescue resulted in the stabilization of hypoxia-inducible factor 1alpha (HIF-1alpha) and increased production of HIF-1alpha-responsive genes in vivo and in vitro. Thus, Akt1 regulates angiogenesis largely through phosphorylation of eNOS and NO-dependent signaling.

  4. Interaction of nNOS with PSD-95 negatively controls regenerative repair after stroke.

    PubMed

    Luo, Chun-Xia; Lin, Yu-Hui; Qian, Xiao-Dan; Tang, Ying; Zhou, Hai-Hui; Jin, Xing; Ni, Huan-Yu; Zhang, Feng-Yun; Qin, Cheng; Li, Fei; Zhang, Yu; Wu, Hai-Yin; Chang, Lei; Zhu, Dong-Ya

    2014-10-01

    Stroke is a major public health concern. The lack of effective therapies heightens the need for new therapeutic targets. Mammalian brain has the ability to rewire itself to restore lost functionalities. Promoting regenerative repair, including neurogenesis and dendritic remodeling, may offer a new therapeutic strategy for the treatment of stroke. Here, we report that interaction of neuronal nitric oxide synthase (nNOS) with the protein postsynaptic density-95 (PSD-95) negatively controls regenerative repair after stroke in rats. Dissociating nNOS-PSD-95 coupling in neurons promotes neuronal differentiation of neural stem cells (NSCs), facilitates the migration of newborn cells into the injured area, and enhances neurite growth of newborn neurons and dendritic spine formation of mature neurons in the ischemic brain of rats. More importantly, blocking nNOS-PSD-95 binding during the recovery stage improves stroke outcome via the promotion of regenerative repair in rats. Histone deacetylase 2 in NSCs may mediate the role of nNOS-PSD-95 association. Thus, nNOS-PSD-95 can serve as a target for regenerative repair after stroke. Copyright © 2014 the authors 0270-6474/14/3413535-14$15.00/0.

  5. Reliability and Validity of the HoNOS-LD and HoNOS in a Sample of Individuals with Mild to Borderline Intellectual Disability and Severe Emotional and Behavior Disorders

    ERIC Educational Resources Information Center

    Tenneij, Nienke; Didden, Robert; Veltkamp, Eline; Koot, Hans M.

    2009-01-01

    In this study, psychometric properties of the Health of the Nation Outcome scales (HoNOS) and Health of the Nation Outcome Scales for People with Learning Disabilities (HoNOS-LD) were investigated in a sample (n = 79) of (young) adults with mild to borderline intellectual disability (ID) and severe behavior and mental health problems who were…

  6. Insights into the arginine paradox: evidence against the importance of subcellular location of arginase and eNOS

    PubMed Central

    Elms, Shawn; Chen, Feng; Wang, Yusi; Qian, Jin; Askari, Bardia; Yu, Yanfang; Pandey, Deepesh; Iddings, Jennifer; Caldwell, Ruth B.

    2013-01-01

    Reduced production of nitric oxide (NO) is one of the first indications of endothelial dysfunction and precedes overt cardiovascular disease. Increased expression of Arginase has been proposed as a mechanism to account for diminished NO production. Arginases consume l-arginine, the substrate for endothelial nitric oxide synthase (eNOS), and l-arginine depletion is thought to competitively reduce eNOS-derived NO. However, this simple relationship is complicated by the paradox that l-arginine concentrations in endothelial cells remain sufficiently high to support NO synthesis. One mechanism proposed to explain this is compartmentalization of intracellular l-arginine into distinct, poorly interchangeable pools. In the current study, we investigated this concept by targeting eNOS and Arginase to different intracellular locations within COS-7 cells and also BAEC. We found that supplemental l-arginine and l-citrulline dose-dependently increased NO production in a manner independent of the intracellular location of eNOS. Cytosolic arginase I and mitochondrial arginase II reduced eNOS activity equally regardless of where in the cell eNOS was expressed. Similarly, targeting arginase I to disparate regions of the cell did not differentially modify eNOS activity. Arginase-dependent suppression of eNOS activity was reversed by pharmacological inhibitors and absent in a catalytically inactive mutant. Arginase did not directly interact with eNOS, and the metabolic products of arginase or downstream enzymes did not contribute to eNOS inhibition. Cells expressing arginase had significantly lower levels of intracellular l-arginine and higher levels of ornithine. These results suggest that arginases inhibit eNOS activity by depletion of substrate and that the compartmentalization of l-arginine does not play a major role. PMID:23792682

  7. Modeling the Nature of Science with the Mystery Tube

    NASA Astrophysics Data System (ADS)

    Miller, Scott

    2014-12-01

    Oftentimes physics is portrayed as merely a list of facts that we know about the world around us, when in fact it is a way of knowing about that world. At times physics claims to understand the inner working of objects that cannot be directly observed, such as the core of the planets and Sun, or the structure of an atom. It is important for students to learn not only the facts of what we know about science, but also how we know what we know about science, even if we cannot directly observe it. This article describes a new take on a black box activity that has been around for years, the mystery tube.1 It is simple to construct but effective at demonstrating the nature of science (NOS). It illustrates the difference between observation and inference, and steps students through the scientific process. Beginning with a scientific question, students make observations, form a hypothesis, predict further observations, and test them before revising or strengthening their hypothesis. This activity provides a fantastic introduction to NOS, either as an alternative to other NOS activities2 or as a lead-in to a discussion of NOS.3 It can be used as an in-class activity, starting off a discussion of how scientists can claim to know what we know, or it can be used as an introductory lab, setting the foundation for how all subsequent activities should be conducted.

  8. Hindlimb unweighting decreases endothelium-dependent dilation and eNOS expression in soleus not gastrocnemius

    NASA Technical Reports Server (NTRS)

    Woodman, C. R.; Schrage, W. G.; Rush, J. W.; Ray, C. A.; Price, E. M.; Hasser, E. M.; Laughlin, M. H.

    2001-01-01

    We tested the hypothesis that hindlimb unweighting (HLU) decreases endothelium-dependent vasodilation and expression of endothelial nitric oxide synthase (eNOS) and superoxide dismutase-1 (SOD-1) in arteries of skeletal muscle with reduced blood flow during HLU. Sprague-Dawley rats (300-350 g) were exposed to HLU (n = 15) or control (n = 15) conditions for 14 days. ACh-induced dilation was assessed in muscle with reduced [soleus (Sol)] or unchanged [gastrocnemius (Gast)] blood flow during HLU. eNOS and SOD-1 expression were measured in feed arteries (FA) and in first-order (1A), second-order (2A), and third-order (3A) arterioles. Dilation to infusion of ACh in vivo was blunted in Sol but not Gast. In arteries of Sol muscle, HLU decreased eNOS mRNA and protein content. eNOS mRNA content was significantly less in Sol FA (35%), 1A arterioles (25%) and 2A arterioles (18%). eNOS protein content was less in Sol FA (64%) and 1A arterioles (65%) from HLU rats. In arteries of Gast, HLU did not decrease eNOS mRNA or protein. SOD-1 mRNA expression was less in Sol 2A arterioles (31%) and 3A arterioles (29%) of HLU rats. SOD-1 protein content was less in Sol FA (67%) but not arterioles. SOD-1 mRNA and protein content were not decreased in arteries from Gast. These data indicate that HLU decreases endothelium-dependent vasodilation, eNOS expression, and SOD-1 expression primarily in arteries of Sol muscle where blood flow is reduced during HLU.

  9. Upregulation of endothelial nitric oxide synthase (eNOS) and its upstream regulators in Opisthorchis viverrini associated cholangiocarcinoma and its clinical significance.

    PubMed

    Suksawat, Manida; Techasen, Anchalee; Namwat, Nisana; Yongvanit, Puangrat; Khuntikeo, Narong; Titapun, Attapon; Koonmee, Supinda; Loilome, Watcharin

    2017-08-01

    Endothelial nitric oxide synthase (eNOS) is an isoform of the enzyme nitric oxide synthase (NOS) which is constitutively expressed in endothelial cells and plays important roles in vasodilation. We previously reported the importance of eNOS activation in cholangiocarcinoma (CCA) tissues and cell lines. The present study aims to investigate the relative abundance of eNOS and phosphorylated eNOS (P-eNOS) and their upstream regulators VEGFR3, VEGFC, EphA3 and ephrin-A1, in the Opisthorchis viverrini (Ov)/N-nitrosodimethylamine (NDMA)-induced hamster CCA model and in human CCA by semiquantitative immunohistochemical analysis of the relevant tissues. Results from the hamster model suggested an increase in eNOS and P-eNOS and upstream regulators during CCA genesis. In human CCA, high immunohistochemical staining intensity of all investigated proteins was associated with the presence of metastasis. A pairwise analysis of the staining data for eNOS and its upstream regulators showed that a concurrent increase in eNOS/VEGFR3, eNOS/ephrin-A1, eNOS/VEGFC and eNOS/EphA3 was significantly associated with metastasis. An increase in eNOS/VEGFR3, eNOS/ephrin-A1 was also associated with non-papillary type CCA. Additionally, an increase in eNOS and P-eNOS was significantly correlated with a high micro-vessel level (P=0.04). Our results indicate that the development of CCA involves upregulation of eNOS and P-eNOS and their regulators. This may drive angiogenesis and metastasis in CCA. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  10. Activation of eNOS in endothelial cells exposed to ionizing radiation involves components of the DNA damage response pathway

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Nagane, Masaki; Yasui, Hironobu; Sakai, Yuri

    2015-01-02

    Highlights: • eNOS activity is increased in BAECs exposed to X-rays. • ATM is involved in this increased eNOS activity. • HSP90 modulates the radiation-induced activation of ATM and eNOS. - Abstract: In this study, the involvement of ataxia telangiectasia mutated (ATM) kinase and heat shock protein 90 (HSP90) in endothelial nitric oxide synthase (eNOS) activation was investigated in X-irradiated bovine aortic endothelial cells. The activity of nitric oxide synthase (NOS) and the phosphorylation of serine 1179 of eNOS (eNOS-Ser1179) were significantly increased in irradiated cells. The radiation-induced increases in NOS activity and eNOS-Ser1179 phosphorylation levels were significantly reduced bymore » treatment with either an ATM inhibitor (Ku-60019) or an HSP90 inhibitor (geldanamycin). Geldanamycin was furthermore found to suppress the radiation-induced phosphorylation of ATM-Ser1181. Our results indicate that the radiation-induced eNOS activation in bovine aortic endothelial cells is regulated by ATM and HSP90.« less

  11. An evaluation of the particle physics Masterclass as a context for student learning about the nature of science

    NASA Astrophysics Data System (ADS)

    Wadness, Michael J.

    This dissertation addresses the research question: To what extent do secondary school science students attending the U.S. Particle Physics Masterclass change their view of the nature of science (NOS)? The U.S. Particle Physics Masterclass is a physics outreach program run by QuarkNet, a national organization of secondary school physics teachers and particle physicists partially funded by the National Science Foundation and the Department of Energy. The Masterclass is a one-day event in which high school physics students gather at a local research institution to learn about particle physics and the scientific enterprise. Student activities include introductory lectures in particle physics, laboratory tours, data analysis, and the discussion of their findings in a conference-like atmosphere. Although the Masterclass has been previously evaluated for students' learning of particle physics content, it was unknown if students' understanding of NOS changed after attending the Masterclass. This research concerns the problem of science literacy, specifically students' understanding of the nature of science (NOS). Previous research suggests that students do not implicitly acquire a sufficient understanding of NOS through the instruction of science content or through inquiry investigations. The literature suggests that sufficient understanding of NOS will only be successful if it is explicitly taught within a context. Unfortunately, research also suggests that many teachers do not include explicit instruction of NOS due various reasons that include a lack of time, understanding, and resources. Therefore, a need presents itself for curriculum extension programs in which explicit learning of NOS may occur. Due to the Masterclass explicitly including NOS within its introductory presentations, it was hypothesized that the remaining Masterclass activities may provide a context for student learning of NOS. The design of this study was a mixed methodology utilizing repeated

  12. Identification and molecular characterization of nitric oxide synthase (NOS) gene in the intertidal copepod Tigriopus japonicus.

    PubMed

    Jeong, Chang-Bum; Kang, Hye-Min; Seo, Jung Soo; Park, Heum Gi; Rhee, Jae-Sung; Lee, Jae-Seong

    2016-02-10

    In copepods, no information has been reported on the structure or molecular characterization of the nitric oxide synthase (NOS) gene. In the intertidal copepod Tigriopus japonicus, we identified a NOS gene that is involved in immune responses of vertebrates and invertebrates. In silico analyses revealed that nitric oxide (NO) synthase domains, such as the oxygenase and reductase domains, are highly conserved in the T. japonicus NOS gene. The T. japonicus NOS gene was highly transcribed in the nauplii stages, implying that it plays a role in protecting the host during the early developmental stages. To examine the involvement of the T. japonicus NOS gene in the innate immune response, the copepods were exposed to lipopolysaccharide (LPS) and two Vibrio sp. After exposure to different concentrations of LPS and Vibrio sp., T. japonicus NOS transcription was significantly increased over time in a dose-dependent manner, and the NO/nitrite concentration increased as well. Taken together, our findings suggest that T. japonicus NOS transcription is induced in response to an immune challenge as part of the conserved innate immunity. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Nosé-Thermostated Mechanical Systems on the n-Torus

    NASA Astrophysics Data System (ADS)

    Butler, Leo T.

    2018-02-01

    Let {H(q,p) = 1/2{allel p allel}^2 + V(q)} be an n-degree of freedom C r mechanical Hamiltonian on {T^{*}{T}^n} where {r > 2n+2}. When the metric {{allel \\cdot allel}} is flat, the Nosé-thermostated system associated to H is shown to have a positive-measure set of invariant tori near the infinite temperature limit. This is shown to be true for all variable mass thermostats similar to Nosé's, too. These results complement results of Bulter (Nonlinearity 11(29):3454-3463, 2016), Legoll et al. (Arch Ration Mech Anal 184(3):449-463, 2007, Nonlinearity 22(7):1673-1694, 2009).

  14. Morus alba extract modulates blood pressure homeostasis through eNOS signaling.

    PubMed

    Carrizzo, Albino; Ambrosio, Mariateresa; Damato, Antonio; Madonna, Michele; Storto, Marianna; Capocci, Luca; Campiglia, Pietro; Sommella, Eduardo; Trimarco, Valentina; Rozza, Francesco; Izzo, Raffaele; Puca, Annibale A; Vecchione, Carmine

    2016-10-01

    Morus alba is a promising phytomedicine cultivated in oriental countries that is extensively used to prevent and treat various cardiovascular problems. To date, despite its beneficial effects, the molecular mechanisms involved remain unclear. Thus, we investigate the vascular and haemodynamic effects of Morus alba extract in an experimental model focusing our attention on the molecular mechanisms involved. Through vascular reactivity studies, we demonstrate that Morus alba extract evokes endothelial vasorelaxation through a nitric oxide-dependent pathway. Our molecular analysis highlights an increase in endothelial nitric oxide synthase (eNOS) phosphorylation. In vivo administration of Morus alba extract reduces blood pressure levels exclusively in wild-type mice, whereas it fails to evoke any haemodynamic effects in eNOS-deficient mice. Molecular analyses revealed that its beneficial action on vasculature is mediated by the activation of two important proteins that act as stress sensors and chaperones: PERK and heat shock protein 90. Finally, Morus alba extract exerts antihypertensive action in an experimental model of arterial hypertension. Through its action on eNOS signaling, Morus alba extract could act as a food supplement for the regulation of cardiovascular system, mainly in clinical conditions characterized by eNOS dysfunction, such as arterial hypertension. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Light responses and morphology of bNOS-immunoreactive neurons in the mouse retina

    PubMed Central

    Pang, Ji-Jie; Gao, Fan; Wu, Samuel M.

    2010-01-01

    Nitric oxide (NO), produced by NO synthase (NOS), modulates the function of all retinal neurons and ocular blood vessels and participates in the pathogenesis of ocular diseases. To further understand the regulation of ocular NO release, we systematically studied the morphology, topography and light responses of NOS-containing amacrine cells (NOACs) in dark-adapted mouse retina. Immunohistological staining for neuronal NOS (bNOS), combined with retrograde labeling of ganglion cells (GCs) with Neurobiotin (NB, a gap junction permeable dye) and Lucifer yellow (LY, a less permeable dye), was used to identify NOACs. The light responses of ACs were recorded under whole-cell voltage clamp conditions and cell morphology was examined with a confocal microscope. We found that in dark-adapted conditions bNOS-immunoreactivity (IR) was present primarily in the inner nuclear layer and the ganglion cell layer. bNOS-IR somas were negative for LY, thus they were identified as ACs; nearly 6 % of the cells were labeled by NB but not by LY, indicating that they were dye-coupled with GCs. Three morphological subtypes of NOACs (NI, NII and displaced) were identified. The cell density, inter-cellular distance and the distribution of NOACs were studied in whole retinas. Light evoked depolarizing highly sensitive ON-OFF responses in NI cells and less sensitive OFF responses in NII cells. Frequent (1 to 2 Hz) or abrupt change of light-intensity evoked larger peak responses. The possibility for light to modify NO release from NOACs is discussed. PMID:20503422

  16. The Akt1-eNOS Axis Illustrates the Specificity of Kinase-Substrate Relationships in Vivo

    PubMed Central

    Schleicher, Michael; Yu, Jun; Murata, Takahisa; Derakhshan, Berhad; Atochin, Dimitriy; Qian, Li; Kashiwagi, Satoshi; Lorenzo, Annarita Di; Harrison, Kenneth D.; Huang, Paul L.; Sessa, William C.

    2016-01-01

    Akt1 is critical for many in vivo functions; however, the cell-specific substrates responsible remain to be defined. Here, we examine the importance of endothelial nitric oxide synthase (eNOS) as an Akt1 substrate by generating Akt1-deficient mice (Akt1−/− mice) carrying knock-in mutations (serine to aspartate or serine to alanine substitutions) of the critical Akt1 phosphorylation site on eNOS (serine 1176) that render the enzyme “constitutively active” or “less active.” The eNOS mutations did not influence several phenotypes in Akt1−/− mice; however, the defective postnatal angiogenesis characteristic of Akt1−/− mice was rescued by crossing the Akt1−/− mice with mice carrying the constitutively active form of eNOS, but not by crossing with mice carrying the less active eNOS mutant. This genetic rescue resulted in the stabilization of hypoxia-inducible factor 1α (HIF-1α) and increased production of HIF-1α–responsive genes in vivo and in vitro. Thus, Akt1 regulates angiogenesis largely through phosphorylation of eNOS and NO-dependent signaling. PMID:19654415

  17. Explicit Nature of Science and Argumentation Instruction in the Context of Socioscientific Issues: An effect on student learning and transfer

    NASA Astrophysics Data System (ADS)

    Khishfe, Rola

    2014-04-01

    The purpose of the study was two-fold: to (a) investigate the influence of explicit nature of science (NOS) and explicit argumentation instruction in the context of a socioscientific issue on the argumentation skills and NOS understandings of students, and (b) explore the transfer of students' NOS understandings and argumentation skills learned in one socioscientific context into other similar contexts (familiar and unfamiliar). Participants were a total of 121 seventh grade students from two schools. The treatment involved an eight-week unit about the water usage and safety, which was taught by two teachers for two intact groups (Treatments I and II). Explicit NOS instruction was integrated for all groups. However, only the Treatment I groups had the additional explicit argumentation instruction. Participants were pre- and post-tested using an open-ended questionnaire and interviews about two socioscientific issues to assess their learning and transfer of argumentation skills and NOS understandings. Results showed improvements in the learning of argumentation practice and NOS understandings for Treatment I group participants. Similarly, there were improvements in the learning and transfer of NOS understandings for Treatment II group participants with only some improvements for the argumentation practice. Further, some of the Treatment I group participants made connections to argumentation when explicating their NOS understandings by the end of the study. Findings were discussed in light of classroom practice that utilizes an explicit approach, contextual approach, as well as an approach that integrates NOS and argumentation simultaneously.

  18. As an Infused or a Separated Theme? Chinese Science Teacher Educators' Conceptions of Incorporating Nature of Science Instruction in the Courses of Training Pre-Service Science Teachers

    ERIC Educational Resources Information Center

    Wan, Zhi Hong; Wong, Siu Ling

    2013-01-01

    Teaching nature of science (NOS) is beginning to find its place in science education in China. This exploratory study interviewed twenty-four Chinese science teacher educators about their conceptions of teaching NOS to pre-service science teachers. Although five dimensions emerged, this paper mainly focuses on reporting the findings relevant to…

  19. Heat Shock Protein-70 Inducers and iNOS Inhibitors as Therapeutics to Ameliorate Hemorrhagic Shock

    DTIC Science & Technology

    2004-09-01

    downregulation of iNOS can limit tissue injury caused by ischemia / reperfusion or hemorrhage/resuscitation. In our laboratory, geldanamycin, a member of... ischemia / reperfusion [Charier 1999]. Mice deficient in inducible NO synthase (iNOS) also demonstrate limited hemorrhage/resuscitation-induced injury ...tissues and leukotriene B4 (LTB4) generation increases. In a hemorrhage/resuscitation-induced injury model, iNOS, cyclooxygenase- 2 , and CD14 are all

  20. Learning about the Nature of Science Using Newspaper Articles with Scientific Content

    ERIC Educational Resources Information Center

    García-Carmona, Antonio; Acevedo Díaz, José Antonio

    2016-01-01

    This article presents a study aiming at assessing the efficacy of reading newspaper articles with scientific content in order to incorporate nature of science (NOS) aspects in initial primary teacher education. To this aim, a short teaching intervention based on newspaper articles was planned and performed under regular class conditions. First,…

  1. Beyond Nature of Science: The Case for Reconceptualising "Science" for Science Education

    ERIC Educational Resources Information Center

    Erduran, Sibel

    2014-01-01

    In this paper, I argue that contemporary accounts of nature of science (NoS) are limited in their depiction of "science" and that new perspectives are needed to broaden their characterisation and appeal for science education. In particular, I refer to the role of interdisciplinary characterisations of science in informing the theory and…

  2. Inquiry-Based Instruction and Teaching about Nature of Science: Are They Happening?

    ERIC Educational Resources Information Center

    Capps, Daniel K.; Crawford, Barbara A.

    2013-01-01

    Anecdotal accounts from science educators suggest that few teachers are teaching science as inquiry. However, there is little empirical evidence to support this claim. This study aimed to provide evidence-based documentation of the state-of-use of inquiry-based instruction and explicit instruction about nature of science (NOS). We examined the…

  3. Investigating and Promoting Trainee Science Teachers' Conceptual Change of the Nature of Science with Digital Dialogue Games `InterLoc'

    NASA Astrophysics Data System (ADS)

    Mansour, Nasser; Wegerif, Rupert; Skinner, Nigel; Postlethwaite, Keith; Hetherington, Lindsay

    2016-10-01

    The purpose of this study is to explore how an online-structured dialogue environment supported (OSDE) collaborative learning about the nature of science among a group of trainee science teachers in the UK. The software used (InterLoc) is a linear text-based tool, designed to support structured argumentation with openers and `dialogue moves'. A design-based research approach was used to investigate multiple sessions using InterLoc with 65 trainee science teachers. Five participants who showed differential conceptual change in terms of their Nature of Science (NOS) views were purposively selected and closely followed throughout the study by using key event recall interviews. Initially, the majority of participants held naïve views of NOS. Substantial and favourable changes in these views were evident as a result of the OSDE. An examination of the development of the five participants' NOS views indicated that the effectiveness of the InterLoc discussions was mediated by cultural, cognitive, and experiential factors. The findings suggest that InterLoc can be effective in promoting reflection and conceptual change.

  4. Neuroanatomical Relationship of nNOS to GnRH and Kisspeptin Neurons in Adult Female Sheep and Primates.

    PubMed

    Bedenbaugh, Michelle; McCosh, Rick; Lopez, Justin; Connors, John; Goodman, Robert L; Hileman, Stan

    2018-06-21


    Background: Neuronal intermediates that communicate estrogen and progesterone feedback to gonadotropin-releasing hormone (GnRH) neurons are essential for modulating reproductive cyclicity. Individually, kisspeptin and nitric oxide (NO) influence GnRH secretion. However, it is possible these two neuronal intermediates interact with one another to affect reproductive cyclicity. We investigated the neuroanatomical relationship of one isoform of the enzyme that synthesizes NO, neuronal nitric oxide synthase (nNOS), to kisspeptin and GnRH in adult female rhesus monkeys and sheep using dual-label immunofluorescence. Additionally, we evaluated if the phase of the reproductive cycle would affect these relationships. Overall, no effect of stage of cycle was observed for any variable in this study. In the arcuate nucleus (ARC) of sheep, 98.8±3.5% of kisspeptin neurons colocalized with nNOS, and kisspeptin close-contacts were observed onto nNOS neurons. In contrast to ewes, no colocalization was observed between kisspeptin and nNOS in the infundibular arcuate nucleus (INF ARC) of primates, but kisspeptin fibers were apposed to nNOS neurons. In the preoptic area (POA) of ewes, 15.0±4.2% of GnRH neurons colocalized with nNOS. In primates, 38.8±10.1% of GnRH neurons in the mediobasal hypothalamus (MBH) colocalized with nNOS, and GnRH close-contacts were observed onto nNOS neurons in both sheep and primates. Although species differences were observed, this work establishes a neuroanatomical framework between nNOS and kisspeptin and nNOS and GnRH in adult female nonhuman primates and sheep.
    . ©2018S. Karger AG, Basel.

  5. Beer elicits vasculoprotective effects through Akt/eNOS activation.

    PubMed

    Vilahur, Gemma; Casani, Laura; Mendieta, Guiomar; Lamuela-Raventos, Rosa M; Estruch, Ramon; Badimon, Lina

    2014-12-01

    There is controversy regarding the effect of alcohol beverage intake in vascular vasodilatory function in peripheral arteries. The effects of beer intake in coronary vasodilation remain unknown. We investigated whether regular beer intake (alcohol and alcohol-free) protects against hypercholesterolaemia-induced coronary endothelial dysfunction and the mechanisms behind this effect. Pigs were fed 10 days: (i) a Western-type hypercholesterolaemic diet (WD); (ii) WD+low-dose beer (12·5 g alcohol/day); (iii) WD+moderate-dose beer (25 g alcohol/day); or (iv) WD+moderate-dose alcohol-free-beer (0·0 g alcohol/day). Coronary responses to endothelium-dependent vasoactive drugs (acetylcholine: receptor mediated; calcium ionophore-A23189: nonreceptor mediated), endothelium-independent vasoactive drug (SNP) and L-NMMA (NOS-antagonist) were evaluated in the LAD coronary artery by flow Doppler. Coronary Akt/eNOS activation, MCP-1 expression, oxidative DNA damage and superoxide production were assessed. Lipid profile, lipoproteins resistance to oxidation and urinary isoxanthohumol concentration were evaluated. Alcoholic and nonalcoholic beer intake prevented WD-induced impairment of receptor- and non-receptor-operated endothelial-dependent coronary vasodilation. All animals displayed a similar vasodilatory response to SNP and L-NMMA blunted all endothelial-dependent vasorelaxation responses. Haemodynamic parameters remained unchanged. Coronary arteries showed lower DNA damage and increased Akt/eNOS axis activation in beer-fed animals. Animals taking beer showed HDL with higher antioxidant capacity, higher LDL resistance to oxidation and increased isoxanthohumol levels. Weight, lipids levels, liver enzymes and MCP-1 expression were not affected by beer intake. Non-alcoholic-related beer components protect against hyperlipemia-induced coronary endothelial dysfunction by counteracting vascular oxidative damage and preserving the Akt/eNOS pathway. Light-to-moderate beer

  6. Enhancing eNOS activity with simultaneous inhibition of IKKβ restores vascular function in Ins2(Akita+/-) type-1 diabetic mice.

    PubMed

    Krishnan, Manickam; Janardhanan, Preethi; Roman, Linda; Reddick, Robert L; Natarajan, Mohan; van Haperen, Rien; Habib, Samy L; de Crom, Rini; Mohan, Sumathy

    2015-10-01

    The balance of nitric oxide (NO) versus superoxide generation has a major role in the initiation and progression of endothelial dysfunction. Under conditions of high glucose, endothelial nitric oxide synthase (eNOS) functions as a chief source of superoxide rather than NO. In order to improve NO bioavailability within the vessel wall in type-1 diabetes, we investigated treatment strategies that improve eNOS phosphorylation and NO-dependent vasorelaxation. We evaluated methods to increase the eNOS activity by (1) feeding Ins2(Akita) spontaneously diabetic (type-1) mice with l-arginine in the presence of sepiapterin, a precursor of tetrahydrobiopterin; (2) preventing eNOS/NO deregulation by the inclusion of inhibitor kappa B kinase beta (IKKβ) inhibitor, salsalate, in the diet regimen in combination with l-arginine and sepiapterin; and (3) independently increasing eNOS expression to improve eNOS activity and associated NO production through generating Ins2(Akita) diabetic mice that overexpress human eNOS predominantly in vascular endothelial cells. Our results clearly demonstrated that diet supplementation with l-arginine, sepiapterin along with salsalate improved phosphorylation of eNOS and enhanced vasorelaxation of thoracic/abdominal aorta in type-1 diabetic mice. More interestingly, despite the overexpression of eNOS, the in-house generated transgenic eNOS-GFP (TgeNOS-GFP)-Ins2(Akita) cross mice showed an unanticipated effect of reduced eNOS phosphorylation and enhanced superoxide production. Our results demonstrate that enhancement of endogenous eNOS activity by nutritional modulation is more beneficial than increasing the endogenous expression of eNOS by gene therapy modalities.

  7. Imbalance of caveolin-1 and eNOS expression in the pulmonary vasculature of experimental diaphragmatic hernia.

    PubMed

    Hofmann, Alejandro; Gosemann, Jan-Hendrik; Takahashi, Toshiaki; Friedmacher, Florian; Duess, Johannes W; Puri, Prem

    2014-08-01

    Caveolin-1 (Cav-1) exerts major regulatory functions on intracellular signaling pathways originating at the plasma membrane. Cav-1 is a key regulator in adverse lung remodeling and the development of pulmonary hypertension (PH) regulating vasomotor tone through its ability to reduce nitric oxide (NO) production. This low-output endothelial NO synthase (eNOS) derived NO maintains normal pulmonary vascular homeostasis. Cav-1 deficiency leads to increased bioavailability of NO, which has been linked to increased nitrosative stress. Inhibition of eNOS reduced oxidant production and reversed PH, supporting the concept that Cav-1 regulation of eNOS activity is crucial to endothelial homeostasis in lungs. We designed this study to investigate the hypothesis that expression of Cav-1 is downregulated while eNOS expression is upregulated by the pulmonary endothelium in the nitrofen-induced congenital diaphragmatic hernia (CDH). Pregnant rats were exposed to nitrofen or vehicle on day 9.5 (D9.5). Fetuses were sacrificed on D21 and divided into nitrofen and control groups. Quantitative real-time polymerase chain reaction, Western blotting, and confocal immunofluorescence were performed to determine pulmonary gene expression levels and protein expression of Cav-1 and eNOS. Pulmonary Cav-1 gene expression levels were significantly decreased, while eNOS gene expression was significantly increased in nitrofen-induced CDH(+). Western blotting and confocal microscopy revealed decreased pulmonary Cav-1 protein expression, while eNOS protein expression was increased in CDH(+) compared to controls. The striking evidence of markedly decreased gene and protein expression of Cav-1 with concurrently increased eNOS gene and protein expression in the pulmonary vasculature suggests that activation of eNOS secondary to Cav-1 deficiency may play an important role in the pathogenesis of PH in the nitrofen-induced CDH. © 2014 Wiley Periodicals, Inc.

  8. p38 mitogen-activated protein kinase is involved in arginase-II-mediated eNOS-Uncoupling in Obesity

    PubMed Central

    2014-01-01

    Background Endothelial nitric oxide synthase (eNOS)-uncoupling links obesity-associated insulin resistance and type-II diabetes to the increased incidence of cardiovascular disease. Studies have indicated that increased arginase is involved in eNOS-uncoupling through competing with the substrate L-arginine. Given that arginase-II (Arg-II) exerts some of its biological functions through crosstalk with signal transduction pathways, and that p38 mitogen-activated protein kinase (p38mapk) is involved in eNOS-uncoupling, we investigated here whether p38mapk is involved in Arg-II-mediated eNOS-uncoupling in a high fat diet (HFD)-induced obesity mouse model. Methods Obesity was induced in wild type (WT) and Arg-II-deficient (Arg-II-/-) mice on C57BL/6 J background by high-fat diet (HFD, 55% fat) for 14 weeks starting from age of 7 weeks. The entire aortas were isolated and subjected to 1) immunoblotting analysis of the protein level of eNOS, Arg-II and p38mapk activation; 2) arginase activity assay; 3) endothelium-dependent and independent vasomotor responses; 4) en face staining of superoxide anion and NO production with Dihydroethidium and 4,5-Diaminofluorescein Diacetate, respectively, to assess eNOS-uncoupling. To evaluate the role of p38mapk, isolated aortas were treated with p38mapk inhibitor SB203580 (10 μmol/L, 1 h) prior to the analysis. In addition, the role of p38mapk in Arg-II-induced eNOS-uncoupling was investigated in cultured human endothelial cells overexpressing Arg-II in the absence or presence of shRNA against p38mapk. Results HFD enhanced Arg-II expression/activity and p38mapk activity, which was associated with eNOS-uncoupling as revealed by decreased NO and enhanced L-NAME-inhibitable superoxide in aortas of WT obese mice. In accordance, WT obese mice revealed decreased endothelium-dependent relaxations to acetylcholine despite of higher eNOS protein level, whereas Arg-II-/- obese mice were protected from HFD-induced eNOS-uncoupling and

  9. Argumentation, critical thinking, nature of science and socioscientific issues: a dialogue between two researchers

    NASA Astrophysics Data System (ADS)

    Yacoubian, Hagop A.; Khishfe, Rola

    2018-05-01

    The purpose of this paper is to compare and contrast between two theoretical frameworks for addressing nature of science (NOS) and socioscientific issues (SSI) in school science. These frameworks are critical thinking (CT) and argumentation (AR). For the past years, the first and second authors of this paper have pursued research in this area using CT and AR as theoretical frameworks, respectively. Yacoubian argues that future citizens need to develop a critical mindset as they are guided to (1) practice making judgments on what views of NOS to acquire and (2) practice making decisions on SSI through applying their NOS understandings. Khishfe asserts that AR is an important component of decision making when dealing with SSI and the practice in AR in relation to controversial issues is needed for informed decision making. She argues that AR as a framework may assist in the development of more informed understandings of NOS. In this paper, the authors delve into a dialogue for (1) elucidating strengths and potential of each framework, (2) highlighting challenges that they face in their research using the frameworks in question, (3) exploring the extent to which the frameworks can overlap, and (4) proposing directions for future research.

  10. Student Teachers' Understanding and Acceptance of Evolution and the Nature of Science

    ERIC Educational Resources Information Center

    Coleman, Joy; Stears, Michèle; Dempster, Edith

    2015-01-01

    The focus of this study was student teachers at a South African university enrolled in a Bachelor of Education (B.Ed.) programme and a Postgraduate Certificate in Education (PGCE), respectively. The purpose of this study was to explore students' understanding and acceptance of evolution and beliefs about the nature of science (NOS), and to…

  11. Endothelial CaMKII as a regulator of eNOS activity and NO-mediated vasoreactivity

    PubMed Central

    Murthy, Shubha; Koval, Olha M.; Ramiro Diaz, Juan M.; Kumar, Santosh; Nuno, Daniel; Scott, Jason A.; Allamargot, Chantal; Zhu, Linda J.; Broadhurst, Kim; Santhana, Velarchana; Kutschke, William J.; Irani, Kaikobad; Lamping, Kathryn G.; Grumbach, Isabella M.

    2017-01-01

    The multifunctional Ca2+/calmodulin-dependent protein kinase II (CaMKII) is a serine/threonine kinase important in transducing intracellular Ca2+ signals. While in vitro data regarding the role of CaMKII in the regulation of endothelial nitric oxide synthase (eNOS) are contradictory, its role in endothelial function in vivo remains unknown. Using two novel transgenic models to express CaMKII inhibitor peptides selectively in endothelium, we examined the effect of CaMKII on eNOS activation, NO production, vasomotor tone and blood pressure. Under baseline conditions, CaMKII activation was low in the aortic wall. Consistently, systolic and diastolic blood pressure, heart rate and plasma NO levels were unaltered by endothelial CaMKII inhibition. Moreover, endothelial CaMKII inhibition had no significant effect on NO-dependent vasodilation. These results were confirmed in studies of aortic rings transduced with adenovirus expressing a CaMKII inhibitor peptide. In cultured endothelial cells, bradykinin treatment produced the anticipated rapid influx of Ca2+ and transient CaMKII and eNOS activation, whereas CaMKII inhibition blocked eNOS phosphorylation on Ser-1179 and dephosphorylation at Thr-497. Ca2+/CaM binding to eNOS and resultant NO production in vitro were decreased under CaMKII inhibition. Our results demonstrate that CaMKII plays an important role in transient bradykinin-driven eNOS activation in vitro, but does not regulate NO production, vasorelaxation or blood pressure in vivo under baseline conditions. PMID:29059213

  12. Modulation of liver mitochondrial NOS is implicated in thyroid-dependent regulation of O(2) uptake.

    PubMed

    Carreras, M C; Peralta, J G; Converso, D P; Finocchietto, P V; Rebagliati, I; Zaninovich, A A; Poderoso, J J

    2001-12-01

    Changes in O(2) uptake at different thyroid status have been explained on the basis of the modulation of mitochondrial enzymes and membrane biophysical properties. Regarding the nitric oxide (NO) effects, we tested whether liver mitochondrial nitric oxide synthase (mtNOS) participates in the modulation of O(2) uptake in thyroid disorders. Wistar rats were inoculated with 400 microCi (131)I (hypothyroid group), 20 microg thyroxine (T(4))/100 g body wt administered daily for 2 wk (hyperthyroid group) or vehicle (control). Basal metabolic rate, mitochondrial function, and mtNOS activity were analyzed. Systemic and liver mitochondrial O(2) uptake and cytochrome oxidase activity were lower in hypothyroid rats with respect to controls; mitochondrial parameters were further decreased by L-arginine (-42 and -34%, P < 0.05), consistent with 5- to 10-fold increases in matrix NO concentration. Accordingly, mtNOS expression (75%) and activity (260%) were selectively increased in hypothyroidism and reverted by hormone replacement without changes in other nitric oxide isoforms. Moreover, mtNOS activity correlated with serum 3,5,3'-triiodothyronine (T(3)) and O(2) uptake. Increased mtNOS activity was also observed in skeletal muscle mitochondria from hypothyroid rats. Therefore, we suggest that modulation of mtNOS is a substantial part of thyroid effects on mitochondrial O(2) uptake.

  13. Feasibility and dosimetry studies for 18F-NOS as a potential PET radiopharmaceutical for inducible nitric oxide synthase in humans.

    PubMed

    Herrero, Pilar; Laforest, Richard; Shoghi, Kooresh; Zhou, Dong; Ewald, Gregory; Pfeifer, John; Duncavage, Eric; Krupp, Kitty; Mach, Robert; Gropler, Robert

    2012-06-01

    Nitric oxide (NO), the end product of the inducible form of NO synthase (iNOS), is an important mediator of a variety of inflammatory diseases. Therefore, a radiolabeled iNOS radiopharmaceutical for assessing iNOS protein concentration as a marker for its activity would be of value to the study and treatment of NO-related diseases. We recently synthesized an (18)F-radiolabeled analog of the reversible NOS inhibitor, 2-amino-4-methylpyridine ((18)F-NOS), and confirmed its utility in a murine model of lung inflammation. To determine its potential for use in humans, we measured (18)F-NOS myocardial activity in patients after orthotopic heart transplantation (OHT) and correlated it with pathologic allograft rejection, tissue iNOS levels, and calculated human radiation dosimetry. Two groups were studied-a kinetic analysis group and a dosimetry group. In the kinetic analysis group, 10 OHT patients underwent dynamic myocardial (18)F-NOS PET/CT, followed by endomyocardial biopsy. Myocardial (18)F-NOS PET was assessed using volume of distribution; standardized uptake values at 10 min; area under the myocardial moment curve (AUMC); and mean resident time at 5, 10, and 30 min after tracer injection. Tissue iNOS levels were measured by immunohistochemistry. In the dosimetry group, the biodistribution and radiation dosimetry were calculated using whole-body PET/CT in 4 healthy volunteers and 12 OHT patients. The combined time-activity curves were used for residence time calculation, and organ doses were calculated with OLINDA. Both AUMC at 10 min (P < 0.05) and tissue iNOS (P < 0.0001) were higher in patients exhibiting rejection than in those without rejection. Moreover, the (18)F-NOS AUMC at 10 min correlated positively with tissue iNOS at 10 min (R(2) = 0.42, P < 0.05). (18)F-NOS activity was cleared by the hepatobiliary system. The critical organ was the bladder wall, with a dose of 95.3 μGy/MBq, and an effective dose of 15.9 μSv/MBq was calculated. Myocardial (18)F-NOS

  14. Deficiency of iNOS-derived NO accelerates lipid accumulation-independent liver fibrosis in non-alcoholic steatohepatitis mouse model.

    PubMed

    Nozaki, Yuichi; Fujita, Koji; Wada, Koichiro; Yoneda, Masato; Kessoku, Takaomi; Shinohara, Yoshiyasu; Imajo, Kento; Ogawa, Yuji; Nakamuta, Makoto; Saito, Satoru; Masaki, Naohiko; Nagashima, Yoji; Terauchi, Yasuo; Nakajima, Atsushi

    2015-04-01

    Although many of the factors and molecules closely associated with non-alcoholic steatohepatitis (NASH) have been reported, the role of inducible nitric oxide synthase (iNOS)-derived nitric oxide (NO) on the progression of NASH remains unclear. We therefore investigated the role of iNOS-derived NO in NASH pathogenesis with a long-term follow-up study using systemic iNOS-knockout mice under high-fat diet (HFD) conditions. iNOS-knockout and wild-type mice were fed a basal or HFD for 10 or 48 weeks. Lipid accumulation, fibrosis, and inflammation were evaluated, and various factors and molecules closely associated with NASH were analyzed. Marked fibrosis and inflammation (indicators of NASH) were observed in the livers of iNOS-knockout mice compared to wild-type mice after 48 weeks of a HFD; however, lipid accumulation in iNOS-knockout mice livers was less than in the wild-type. Increased expressions of various cytokines that are transcriptionally controlled by NF-kB in iNOS-deficient mice livers were observed during HFD conditions. iNOS-derived NO may play a protective role against the progression to NASH during an HFD by preventing fibrosis and inflammation, which are mediated by NF-kB activation in Kupffer cells. A lack of iNOS-derived NO accelerates progression to NASH without excessive lipid accumulation.

  15. nNOS expression in the brain of rats after burn and the effect of the ACE inhibitor captopril.

    PubMed

    Demiralay, Ebru; Saglam, Ibrahim Yaman; Ozdamar, Emine Nur; Sehirli, Ahmet Ozer; Sener, Goksel; Saglam, Esra

    2013-08-01

    To investigate the role of endogenous neuronal nitric oxide synthase (nNOS) on brain injury after burn and the effects of the captopril. Wistar albino rats (200-250 g) were exposed on the dorsal surface to 90°C (burn) or 25°C (sham) water for 10 s. The ACE group was treated with intraperitoneal 10 mg/kg captopril immediately after burn and this treatment was repeated twice daily. At the end of the 24 h brain samples were taken. nNOS was studied in brain areas by immunohistochemistry. There was no difference between the cerebellar and hypothalamic areas the nNOS expression of all groups. nNOS expression increased in the frontal cortex, striatum and midbrain in the burn group compared to the control group. In the frontal cortex, nNOS expression significantly decreased after ACE inhibitor treatment (p<0.05). The striatal nNOS of the ACE group significantly increased when compared to the control group (p=0.001). In the midbrain of the animals, nNOS decreased in the ACE group. Hippocampal nNOS expression did not change after burn and significantly increased after ACE inhibitor therapy (p<0.05). Our data showed that the pathophysiological events following burn appear to be related to an acute inflammatory reaction which is associated with nNOS in the frontal cortex, striatum and midbrain, and captopril treatment abrogates the nNOS response in the frontal cortex and midbrain. Copyright © 2012 Elsevier Ltd and ISBI. All rights reserved.

  16. Value-added beef products (Productos Carnicos con Valor Agregado)

    Treesearch

    Mac Donaldson; Will Holder; Jan Holder

    2006-01-01

    I'm speaking for Will and Jan Holder, who couldn't be here. I happen to be familiar with Will and Jan's company, Ervin's Natural Beef, and its program because I've sold them cattle. Will and Jan's value-added beef program is based on their family ranch in the area known as The Blue, in the mountains of eastern Arizona.

  17. Effects of Paracetamol on NOS, COX, and CYP Activity and on Oxidative Stress in Healthy Male Subjects, Rat Hepatocytes, and Recombinant NOS

    PubMed Central

    Trettin, Arne; Böhmer, Anke; Suchy, Maria-Theresia; Probst, Irmelin; Staerk, Ulrich; Stichtenoth, Dirk O.; Frölich, Jürgen C.

    2014-01-01

    Paracetamol (acetaminophen) is a widely used analgesic drug. It interacts with various enzyme families including cytochrome P450 (CYP), cyclooxygenase (COX), and nitric oxide synthase (NOS), and this interplay may produce reactive oxygen species (ROS). We investigated the effects of paracetamol on prostacyclin, thromboxane, nitric oxide (NO), and oxidative stress in four male subjects who received a single 3 g oral dose of paracetamol. Thromboxane and prostacyclin synthesis was assessed by measuring their major urinary metabolites 2,3-dinor-thromboxane B2 and 2,3-dinor-6-ketoprostaglandin F1α, respectively. Endothelial NO synthesis was assessed by measuring nitrite in plasma. Urinary 15(S)-8-iso-prostaglanding F2α was measured to assess oxidative stress. Plasma oleic acid oxide (cis-EpOA) was measured as a marker of cytochrome P450 activity. Upon paracetamol administration, prostacyclin synthesis was strongly inhibited, while NO synthesis increased and thromboxane synthesis remained almost unchanged. Paracetamol may shift the COX-dependent vasodilatation/vasoconstriction balance at the cost of vasodilatation. This effect may be antagonized by increasing endothelial NO synthesis. High-dosed paracetamol did not increase oxidative stress. At pharmacologically relevant concentrations, paracetamol did not affect NO synthesis/bioavailability by recombinant human endothelial NOS or inducible NOS in rat hepatocytes. We conclude that paracetamol does not increase oxidative stress in humans. PMID:24799980

  18. 75 FR 58445 - Exelon Generation Company, LLC; Peach Bottom Atomic Power Station Unit Nos. 2 and 3...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-24

    ... NUCLEAR REGULATORY COMMISSION [Docket Nos. 50-277 AND 50-278; NRC-2010-0303] Exelon Generation Company, LLC; Peach Bottom Atomic Power Station Unit Nos. 2 and 3; Environmental Assessment and Finding of... Bottom Atomic Power Station (PBAPS), Unit Nos. 2 and 3, located in York and Lancaster Counties...

  19. Elementary Teachers' Perceptions about the Effective Features of Explicit-Reflective Nature of Science Instruction

    ERIC Educational Resources Information Center

    Adibelli-Sahin, Elif; Deniz, Hasan

    2017-01-01

    This qualitative study explored elementary teachers' perceptions about the effective features of explicit-reflective nature of science (NOS) instruction. Our participants were four elementary teachers from a public charter school located in the Southwestern U.S.A. The four elementary teachers participated in an academic year-long professional…

  20. nNOS inhibitors attenuate methamphetamine-induced dopaminergic neurotoxicity but not hyperthermia in mice.

    PubMed

    Itzhak, Y; Martin, J L; Ail, S F

    2000-09-11

    Methamphetamine (METH)-induced dopaminergic neurotoxicity is associated with hyperthermia. We investigated the effect of several neuronal nitric oxide synthase (nNOS) inhibitors on METH-induced hyperthermia and striatal dopaminergic neurotoxicity. Administration of METH (5 mg/kg; q. 3 h x 3) to Swiss Webster mice produced marked hyperthermia and 50-60% depletion of striatal dopaminergic markers 72 h after METH administration. Pretreatment with the nNOS inhibitors S-methylthiocitrulline (SMTC; 10 mg/kg) or 3-bromo-7-nitroindazole (3-Br-7-NI; 20 mg/kg) before each METH injection did not affect the persistent hyperthermia produced by METH, but afforded protection against the depletion of dopaminergic markers. A low dose (25 mg/kg) of the nNOS inhibitor 7-nitroindazole (7-NI) did not affect METH-induced hyperthermia, but a high dose (50 mg/kg) produced significant hypothermia. These findings indicate that low dose of selective nNOS inhibitors protect against METH-induced neurotoxicity with no effect on body temperature and support the hypothesis that nitric oxide (NO) and peroxynitrite have a major role in METH-induced dopaminergic neurotoxicity.

  1. NOS2A, TLR4, and IFNGR1 interactions influence pulmonary tuberculosis susceptibility in African-Americans

    PubMed Central

    Velez, Digna Rosa; Hulme, William F.; Myers, Jamie L.; Weinberg, J. Brice; Levesque, Marc C.; Stryjewski, Martin E.; Abbate, Eduardo; Estevan, Rosa; Patillo, Sara G.; Gilbert, John R; Hamilton, Carol D.; Scott, William K.

    2010-01-01

    Tuberculosis (TB) has substantial mortality worldwide with 5-10% of those exposed progressing to active TB disease. Studies in mice and humans indicate that the inducible nitric oxide synthase (iNOS) molecule plays an important role in immune response to TB. A mixed case-control association study of individuals with TB, relatives, or close contact controls was performed in 726 individuals (279 case and 166 control African-Americans; 198 case and 123 control Caucasians). Thirty-nine single nucleotide polymorphisms (SNPs) were selected from the NOS2A gene for single SNP, haplotype, and multilocus interaction analyses with other typed candidate genes using generalized estimating equations. In African-Americans, ten NOS2A SNPs were associated with TB. The strongest associations were observed at rs2274894 (odds ratio (OR) = 1.84, 95% confidence interval (CI) [1.23-2.77], p = 0.003) and rs7215373 (OR 1.67, 95% CI [1.17-2.37], p = 0.004), both of which passed a false discovery rate (FDR) correction for multiple comparisons (q*=0.20). The strongest gene-gene interactions were observed between NOS2A rs2248814 and IFNGR1 rs1327474 (p = 0.0004) and NOS2A rs944722 and IFNGR1 rs1327474 (p = 0.0006). Three other SNPs in NOS2A interacted with TLR4 rs5030729 and five other NOS2A SNPs interacted with IFNGR1 rs1327474. No significant associations were observed in Caucasians. These results suggest that NOS2A variants may contribute to TB susceptibility, particularly in individuals of African descent, and may act synergistically with SNPs in TLR4 and IFNGR1. PMID:19575238

  2. Hemozoin Regulates iNOS Expression by Modulating the Transcription Factor NF-κB in Macrophages.

    PubMed

    Ranjan, Ravi; Karpurapu, Manjula; Rani, Asha; Chishti, Athar H; Christman, John W

    2016-01-01

    Hemozoin (Hz) is released from ruptured erythrocytes during malaria infection caused by Plasmodium sp., in addition the malaria infected individuals are prone to bacterial sepsis. The molecular interactions between Hz, bacterial components and macrophages remains poorly investigated. In this report, we investigated the combinatorial immune-modulatory effects of phagocytosed Hz, Interferon gamma (IFNγ) or lipopolysaccharide (LPS) in macrophages. Macrophages were treated with various concentrations of commercial synthetic Hz, and surprisingly it did not result in inducible nitric oxide synthase (iNOS) expression. However, when macrophages were pretreated with Hz and then challenged with IFNγ or LPS, there was a differential impact on iNOS expression. There was an increase in iNOS expression when macrophages were pre-treated with Hz and subsequently treated with IFNγ when compared to IFNγ alone. Whereas iNOS expression was reduced when Hz phagocytosed macrophages were stimulated with LPS compared to LPS alone. Furthermore, there was an increased activation of NF-κB in Hz phagocytosed macrophages that were challenged with IFNγ. The interaction between Hz and macrophages has an impact on iNOS expression.

  3. 75 FR 13600 - Virginia Electric and Power Company, North Anna Power Station, Unit Nos. 1 and 2, Surry Power...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-22

    ...- 2010-0116] Virginia Electric and Power Company, North Anna Power Station, Unit Nos. 1 and 2, Surry Power Station, Unit Nos. 1 and 2; Environmental Assessment and Finding of No Significant Impact The U.S... Anna Power Station, Unit Nos. 1 and 2 (NAPS), and Surry Power Station, Unit Nos. 1 and 2 (SPS), located...

  4. 75 FR 53984 - Virginia Electric and Power Company North Anna Power Station, Unit Nos. 1 and 2 Surry Power...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-02

    ...- 2010-0283] Virginia Electric and Power Company North Anna Power Station, Unit Nos. 1 and 2 Surry Power Station, Unit Nos. 1 and 2 Environmental Assessment and Finding of No Significant Impact The U.S. Nuclear... applications for North Anna Power Station, Unit Nos. 1 and 2 (NAPS), for Renewed Facility Operating License Nos...

  5. Reduced-cost linear-response CC2 method based on natural orbitals and natural auxiliary functions

    PubMed Central

    Mester, Dávid

    2017-01-01

    A reduced-cost density fitting (DF) linear-response second-order coupled-cluster (CC2) method has been developed for the evaluation of excitation energies. The method is based on the simultaneous truncation of the molecular orbital (MO) basis and the auxiliary basis set used for the DF approximation. For the reduction of the size of the MO basis, state-specific natural orbitals (NOs) are constructed for each excited state using the average of the second-order Møller–Plesset (MP2) and the corresponding configuration interaction singles with perturbative doubles [CIS(D)] density matrices. After removing the NOs of low occupation number, natural auxiliary functions (NAFs) are constructed [M. Kállay, J. Chem. Phys. 141, 244113 (2014)], and the NAF basis is also truncated. Our results show that, for a triple-zeta basis set, about 60% of the virtual MOs can be dropped, while the size of the fitting basis can be reduced by a factor of five. This results in a dramatic reduction of the computational costs of the solution of the CC2 equations, which are in our approach about as expensive as the evaluation of the MP2 and CIS(D) density matrices. All in all, an average speedup of more than an order of magnitude can be achieved at the expense of a mean absolute error of 0.02 eV in the calculated excitation energies compared to the canonical CC2 results. Our benchmark calculations demonstrate that the new approach enables the efficient computation of CC2 excitation energies for excited states of all types of medium-sized molecules composed of up to 100 atoms with triple-zeta quality basis sets. PMID:28527453

  6. Converging evidence for an impact of a functional NOS gene variation on anxiety-related processes

    PubMed Central

    Haaker, Jan; Glotzbach-Schoon, Evelyn; Schümann, Dirk; Andreatta, Marta; Mechias, Marie-Luise; Raczka, Karolina; Gartmann, Nina; Büchel, Christian; Mühlberger, Andreas; Pauli, Paul; Reif, Andreas; Kalisch, Raffael; Lonsdorf, Tina B.

    2016-01-01

    Abstract Being a complex phenotype with substantial heritability, anxiety and related phenotypes are characterized by a complex polygenic basis. Thereby, one candidate pathway is neuronal nitric oxide (NO) signaling, and accordingly, rodent studies have identified NO synthase (NOS-I), encoded by NOS1, as a strong molecular candidate for modulating anxiety and hippocampus-dependent learning processes. Using a multi-dimensional and -methodological replication approach, we investigated the impact of a functional promoter polymorphism (NOS1-ex1f-VNTR) on human anxiety-related phenotypes in a total of 1019 healthy controls in five different studies. Homozygous carriers of the NOS1-ex1f short-allele displayed enhanced trait anxiety, worrying and depression scores. Furthermore, short-allele carriers were characterized by increased anxious apprehension during contextual fear conditioning. While autonomous measures (fear-potentiated startle) provided only suggestive evidence for a modulatory role of NOS1-ex1f-VNTR on (contextual) fear conditioning processes, neural activation at the amygdala/anterior hippocampus junction was significantly increased in short-allele carriers during context conditioning. Notably, this could not be attributed to morphological differences. In accordance with data from a plethora of rodent studies, we here provide converging evidence from behavioral, subjective, psychophysiological and neuroimaging studies in large human cohorts that NOS-I plays an important role in anxious apprehension but provide only limited evidence for a role in (contextual) fear conditioning. PMID:26746182

  7. Turning Crisis into Opportunity: Nature of Science and Scientific Inquiry as Illustrated in the Scientific Research on Severe Acute Respiratory Syndrome

    NASA Astrophysics Data System (ADS)

    Wong, Siu Ling; Kwan, Jenny; Hodson, Derek; Yung, Benny Hin Wai

    2009-01-01

    Interviews with key scientists who had conducted research on Severe Acute Respiratory Syndrome (SARS), together with analysis of media reports, documentaries and other literature published during and after the SARS epidemic, revealed many interesting aspects of the nature of science (NOS) and scientific inquiry in contemporary scientific research in the rapidly growing field of molecular biology. The story of SARS illustrates vividly some NOS features advocated in the school science curriculum, including the tentative nature of scientific knowledge, theory-laden observation and interpretation, multiplicity of approaches adopted in scientific inquiry, the inter-relationship between science and technology, and the nexus of science, politics, social and cultural practices. The story also provided some insights into a number of NOS features less emphasised in the school curriculum—for example, the need to combine and coordinate expertise in a number of scientific fields, the intense competition between research groups (suspended during the SARS crisis), the significance of affective issues relating to intellectual honesty and the courage to challenge authority, the pressure of funding issues on the conduct of research and the ‘peace of mind’ of researchers, These less emphasised elements provided empirical evidence that NOS knowledge, like scientific knowledge itself, changes over time. They reflected the need for teachers and curriculum planners to revisit and reconsider whether the features of NOS currently included in the school science curriculum are fully reflective of the practice of science in the 21st century. In this paper, we also report on how we made use of extracts from the news reports and documentaries on SARS, together with episodes from the scientists’ interviews, to develop a multimedia instructional package for explicitly teaching the prominent features of NOS and scientific inquiry identified in the SARS research.

  8. iNOS Activity Modulates Inflammation, Angiogenesis, and Tissue Fibrosis in Polyether-Polyurethane Synthetic Implants

    PubMed Central

    Cassini-Vieira, Puebla; Araújo, Fernanda Assis; da Costa Dias, Filipi Leles; Russo, Remo Castro; Andrade, Silvia Passos; Teixeira, Mauro Martins; Barcelos, Luciola Silva

    2015-01-01

    There is considerable interest in implantation techniques and scaffolds for tissue engineering and, for safety and biocompatibility reasons, inflammation, angiogenesis, and fibrosis need to be determined. The contribution of inducible nitric oxide synthase (iNOS) in the regulation of the foreign body reaction induced by subcutaneous implantation of a synthetic matrix was never investigated. Here, we examined the role of iNOS in angiogenesis, inflammation, and collagen deposition induced by polyether-polyurethane synthetic implants, using mice with targeted disruption of the iNOS gene (iNOS−/−) and wild-type (WT) mice. The hemoglobin content and number of vessels were decreased in the implants of iNOS−/− mice compared to WT mice 14 days after implantation. VEGF levels were also reduced in the implants of iNOS−/− mice. In contrast, the iNOS−/− implants exhibited an increased neutrophil and macrophage infiltration. However, no alterations were observed in levels of CXCL1 and CCL2, chemokines related to neutrophil and macrophage migration, respectively. Furthermore, the implants of iNOS−/− mice showed boosted collagen deposition. These data suggest that iNOS activity controls inflammation, angiogenesis, and fibrogenesis in polyether-polyurethane synthetic implants and that lack of iNOS expression increases foreign body reaction to implants in mice. PMID:26106257

  9. A central role of eNOS in the protective effect of wine against metabolic syndrome.

    PubMed

    Leighton, Federico; Miranda-Rottmann, Soledad; Urquiaga, Inés

    2006-01-01

    The positive health effects derived from moderate wine consumption are pleiotropic. They appear as improvements in cardiovascular risk factors such as plasma lipids, haemostatic mechanisms, endothelial function and antioxidant defences. The active principles would be ethanol and mainly polyphenols. Results from our and other laboratories support the unifying hypothesis that the improvements in risk factors after red wine consumption are mediated by endothelial nitric oxide synthase (eNOS). Many genes are involved, but the participation of eNOS would be a constant feature. The metabolic syndrome is a cluster of metabolic risk factors associated with high risk of cardiovascular disease (CVD). The National Cholesterol Education Programmmes Adult Treatment Panel III (NCEPATP III) clinical definition of the metabolic syndrome requires the presence of at least three risk factors, from among abdominal obesity, high plasma triacylglycerols, low plasma HDL, high blood pressure and high fasting plasma glucose. The molecular mechanisms responsible for the metabolic syndrome are not known. Since metabolic syndrome apparently affects 10-30% of the population in the world, research on its pathogenesis and control is needed. The recent finding that eNOS knockout mice present a cluster of cardiovascular risk factors comparable to those of the metabolic syndrome suggests that defects in eNOS function may cause human metabolic syndrome. These mice are hypertensive, insulin resistant and dyslipidemic. Further support for a pathogenic role of eNOS comes from the finding in humans that eNOS polymorphisms associate with insulin resistance and diabetes, with hypertension, with inflammatory and oxidative stress markers and with albuminuria. So, the data sustain the hypothesis that eNOS enhancement should reduce metabolic syndrome incidence and its consequences. Therefore red wine, since it enhances eNOS function, should be considered as a potential tool for the control of metabolic

  10. A meta-analysis of eNOS and ACE gene polymorphisms and risk of pre-eclampsia in women.

    PubMed

    Shaik, A P; Sultana, A; Bammidi, V K; Sampathirao, K; Jamil, K

    2011-10-01

    A meta-analyses of endothelial nitric oxide synthase (eNOS) and angiotensin-converting enzyme (ACE) gene polymorphisms in pre-eclampsia was performed. We shortlisted 33 studies (17 for ACE; 16 for eNOS gene polymorphisms), of which 29 articles (16 for ACE and 15 for eNOS) were analysed. Overall, 1,620 cases with pre-eclampsia and 2,158 controls were analysed for intron 16 insertion-deletion polymorphism in ACE gene. A total of 1,610 subjects with pre-eclampsia and 2,875 controls were analysed for the Glu298Asp in eNOS gene. Overall, the random-effects odds ratio (OR) with Glu298Asp in eNOS gene was 0.958 (95% confidence intervals, CI 0.747-1.228, p > 0.05), and for the insertion-deletion/ACE polymorphism was 0.987 (95% CI 0.698-1.395, p > 0.05). Significant heterogeneity was observed in the studies that evaluated polymorphisms in ACE (Q value = 55.6; I(2) = 73; p value = 0.000); and eNOS (Q value = 37.2; I(2) = 62.4; p value = 0.001) polymorphisms. No significant risk of pre-eclampsia was observed in both eNOS and ACE genes with these polymorphisms.

  11. Los Angeles County Poor Farm, Patient Ward Nos. 210 & ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Los Angeles County Poor Farm, Patient Ward Nos. 210 & 211 - Type B Plan, 7601 Imperial Highway; bounded by Esperanza Street, Laurel Street, Flores Street, and Descanso Street, Downey, Los Angeles County, CA

  12. Inducible NOS inhibitor 1400W reduces hypoxia/re-oxygenation injury in rat lung.

    PubMed

    Rus, Alma; Castro, Lourdes; Del Moral, Maria Luisa; Peinado, Angeles

    2010-01-01

    Nitric oxide (NO(*)) from inducible NO(*) synthase (iNOS) has been reported to either protect against, or contribute to, hypoxia/re-oxygenation lung injury. The present work aimed to clarify this double role in the hypoxic lung. With this objective, a follow-up study was made in Wistar rats submitted to hypoxia/re-oxygenation (hypoxia for 30 min; re-oxygenation of 0 h, 48 h, and 5 days), with or without prior treatment with the selective iNOS inhibitor 1400W (10 mg/kg). NO(*) levels (NOx), lipid peroxidation, apoptosis, and protein nitration were analysed. This is the first time-course study which investigates the effects of 1400W during hypoxia/re-oxygenation in the rat lung. The results showed that the administration of 1400W lowered NOx levels in all the experimental groups. In addition, lipid peroxidation, the percentage of apoptotic cells, and nitrated protein expression fell in the late post-hypoxia period (48 h and 5 days). Our results reveal that the inhibition of iNOS in the hypoxic lung reduced the damage observed before the treatment with 1400W, suggesting that iNOS-derived NO(*) may exert a negative effect on this organ during hypoxia/re-oxygenation. These findings are notable, since they indicate that any therapeutic strategy aimed at controlling excess generation of NO(*) from iNOS may be useful in alleviating NO(*)-mediated adverse effects in hypoxic lungs.

  13. Cytokine and iNOS profiles in lymph nodes of dogs naturally infected with Leishmania infantum and their association with the parasitic DNA load and clinical and histopathological features.

    PubMed

    de Vasconcelos, Tassia Cristina Bello; Doyen, Noelle; Cavaillon, Jean-Marc; Bruno, Sávio Freire; de Campos, Monique Paiva; de Miranda, Luisa Helena Monteiro; Madeira, Maria de Fátima; Belo, Vinícius Silva; Figueiredo, Fabiano Borges

    2016-08-30

    In South America, visceral leishmaniasis is a zoonotic disease with severe evolution characteristics in humans, and dogs are its main reservoir. In this context, this study aimed to evaluate the clinical status of dogs from a Brazilian endemic area naturally, at Barra Mansa municipality, infected with Leishmania infantum, in conjunction with their histopathological profile and, in order to determine possible markers of susceptibility or resistance to the disease, parasitic DNA load, cytokine and iNOS mRNA expression profiles were investigated in lymph nodes. High levels of IFN-ɣ and IL-6 mRNA were detected. Both IFN-ɣ and IL-6 mRNA were associated with disorganization of the corticomedullary region. IFN-ɣ and TNF-α mRNA were associated with the absence of follicular hyperplasia. The regulatory pathway was remarkable with IL-10 mRNA detection and its significant association with the severity of the disease. Plasmacytosis and sinus histiocytosis were associated with high loads of parasitic DNA, but there was no significant association between the parasite DNA load and animal clinical alterations. Since high parasitic loads were found in animals with or without symptoms, clinical examination cannot be considered as a criterion for disease susceptibility assessment. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Detecting nitrous oxide reductase (NosZ) genes in soil metagenomes: method development and implications for the nitrogen cycle.

    PubMed

    Orellana, L H; Rodriguez-R, L M; Higgins, S; Chee-Sanford, J C; Sanford, R A; Ritalahti, K M; Löffler, F E; Konstantinidis, K T

    2014-06-03

    Microbial activities in soils, such as (incomplete) denitrification, represent major sources of nitrous oxide (N2O), a potent greenhouse gas. The key enzyme for mitigating N2O emissions is NosZ, which catalyzes N2O reduction to N2. We recently described "atypical" functional NosZ proteins encoded by both denitrifiers and nondenitrifiers, which were missed in previous environmental surveys (R. A. Sanford et al., Proc. Natl. Acad. Sci. U. S. A. 109:19709-19714, 2012, doi:10.1073/pnas.1211238109). Here, we analyzed the abundance and diversity of both nosZ types in whole-genome shotgun metagenomes from sandy and silty loam agricultural soils that typify the U.S. Midwest corn belt. First, different search algorithms and parameters for detecting nosZ metagenomic reads were evaluated based on in silico-generated (mock) metagenomes. Using the derived cutoffs, 71 distinct alleles (95% amino acid identity level) encoding typical or atypical NosZ proteins were detected in both soil types. Remarkably, more than 70% of the total nosZ reads in both soils were classified as atypical, emphasizing that prior surveys underestimated nosZ abundance. Approximately 15% of the total nosZ reads were taxonomically related to Anaeromyxobacter, which was the most abundant genus encoding atypical NosZ-type proteins in both soil types. Further analyses revealed that atypical nosZ genes outnumbered typical nosZ genes in most publicly available soil metagenomes, underscoring their potential role in mediating N2O consumption in soils. Therefore, this study provides a bioinformatics strategy to reliably detect target genes in complex short-read metagenomes and suggests that the analysis of both typical and atypical nosZ sequences is required to understand and predict N2O flux in soils. Nitrous oxide (N2O) is a potent greenhouse gas with ozone layer destruction potential. Microbial activities control both the production and the consumption of N2O, i.e., its conversion to innocuous dinitrogen gas (N

  15. The effect of 5E-SWH learning model on students' view of nature of science

    NASA Astrophysics Data System (ADS)

    Sinthuwa, Waralee; Sangpradit, Theerapong

    2018-01-01

    View of Nature of Science (NOS) is one of key factors to support students' scientific literacy. So, it includes in scientific learning goals internationally. As in the literature, the many potential benefits associated with appropriate view of NOS. For instance, it influences students' learning achievement in science and lets students see how science connected to their real world. The aim of this study was to develop the 5E-SWH learning model to enhance 12th grade students' view of NOS. Eighty-eight students participated in this study. They were separated into two groups. Forty-four students had learnt biology by using 5E-SWH learning unit, but another group had learnt by using traditional 5E. View of NOS questionnaire that was adapted from the Views of NOS Questionnaire (VNOS-C) was applied with the both groups as pretest and posttest. The questionnaire consisted of ten open-ended items. The semi-structured interview protocol was also used with thirty students and feedback on the lesson record was provided in order to triangulate students' view of NOS. The analyzed results were approved by peer review. In addition, the during the implementation, data from voice recorder was transcribed and used discourse analysis to show students' NOS views. There were three aspects that relate to genetics technology content. These aspects included the subjective, empirical, and social and culture. Students' responses were categorized into 3 groups including informed, adequate and inadequate view. The results showed that the majority of participants held inadequate views of the subjective and empirical aspect at the beginning of the study. In addition, almost student as well as held adequate view of the social and culture aspect and they had misconception in some target NOS aspects. After that, they had learnt genetics technology content by using 5E-SWH learning model for 15 periods (50 min/ period). Both student groups' view of NOS was compared with each other. The study showed

  16. Teaching Explicitly and Reflecting on Elements of Nature of Science: a Discourse-Focused Professional Development Program with Four Fifth-Grade Teachers

    NASA Astrophysics Data System (ADS)

    Piliouras, Panagiotis; Plakitsi, Katerina; Seroglou, Fanny; Papantoniou, Georgia

    2017-06-01

    The nature of science (NOS) has become a central goal of science education in many countries. This study refers to a developmental work research program, in which four fifth-grade elementary in-service teachers participated. It aimed to improve their understandings of NOS and their abilities to teach it effectively to their students. The 1-year-long, 2012-2013, program consisted of a series of activities to support teachers to develop their pedagogical content knowledge of NOS. In order to accomplish our goal, we enabled teacher-researchers to analyze their own discourse practices and to trace evidence of effective NOS teaching. Many studies indicate the importance of examining teachers' discussions about science in the classroom, since it is teachers' understanding of NOS reflected in these discussions that will have a vital impact on students' learning. Our proposal is based on the assumption that reflecting on the ways people form meanings enables us to examine and seek alternative ways to communicate aspects of NOS during science lessons. The analysis of discourse data, which has been carried out with the teacher-researchers' active participation, indicated that initially only a few aspects of NOS were implicitly incorporated in teacher-researchers' instruction. As the program evolved, all teacher-researchers presented more informed views on targeted NOS aspects. On the whole, our discourse-focused professional development program with its participatory, explicit, and reflective character indicated the importance of involving teacher-researchers in analyzing their own talk. It is this involvement that results in obtaining a valuable awareness of aspects concerning pedagogical content knowledge of NOS teaching.

  17. Differential response of nNOS knockout mice to MDMA ("ecstasy")- and methamphetamine-induced psychomotor sensitization and neurotoxicity.

    PubMed

    Itzhak, Yossef; Anderson, Karen L; Ali, Syed F

    2004-10-01

    It has been shown that mice deficient in neuronal nitric oxide synthase (nNOS) gene are resistant to cocaine-induced psychomotor sensitization and methamphetamine (METH)-induced dopaminergic neurotoxicity. The present study was undertaken to investigate the hypothesis that nNOS has a major role in dopamine (DA)- but not serotonin (5-hydroxytryptamine; 5-HT)-mediated effects of psychostimulants. The response of nNOS knockout (KO) and wild-type (WT) mice to the psychomotor-stimulating and neurotoxic effects of 3,4-methylenedioxymethamphetamine (MDMA; "Ecstasy") and METH were investigated. Repeated administration of MDMA for 5 days resulted in psychomotor sensitization in both WT and nNOS KO mice, while repeated administration of METH caused psychomotor sensitization in WT but not in KO mice. Sensitization to both MDMA and METH was persistent for 40 days in WT mice, but not in nNOS KO mice. These findings suggest that the induction of psychomotor sensitization to MDMA and METH is NO independent and NO dependent, respectively, while the persistence of sensitization to both drugs is NO dependent. For the neurochemical studies, a high dose of MDMA caused marked depletion of 5-HT in several brain regions of both WT and KO mice, suggesting that the absence of the nNOS gene did not afford protection against MDMA-induced depletion of 5-HT. Striatal dopaminergic neurotoxicity caused by high doses of MDMA and METH in WT mice was partially prevented in KO mice administered with MDMA, but it was fully precluded in KO mice administered with METH. The differential response of nNOS KO mice to the behavioral and neurotoxic effects of MDMA and METH suggests that the nNOS gene is required for the expression and persistence of DA-mediated effects of METH and MDMA, while 5-HT-mediated effects of MDMA (induction of sensitization and 5-HT depletion) are not dependent on nNOS.

  18. Sildenafil Promotes eNOS Activation and Inhibits NADPH Oxidase in the Transgenic Sickle Cell Mouse Penis

    PubMed Central

    Musicki, Biljana; Bivalacqua, Trinity J.; Champion, Hunter C.; Burnett, Arthur L.

    2014-01-01

    Introduction Sickle cell disease (SCD)-associated vasculopathy in the penis is characterized by aberrant nitric oxide and phosphodiesterase (PDE) 5 signaling, and by increased oxidative stress. Preliminary clinical trials show that continuous treatment with PDE5 inhibitor sildenafil unassociated with sexual activity decreases priapic activity in patients with SCD. However, the mechanism of its vasculoprotective effect in the penis remains unclear. Aims We evaluated whether continuous administration of PDE5 inhibitor sildenafil promotes eNOS function at posttranslational levels and decreases superoxide-producing enzyme NADPH oxidase activity in the sickle cell mouse penis. Methods SCD transgenic mice were used as an animal model of SCD. WT mice served as controls. Mice received treatment with the PDE5 inhibitor sildenafil (100 mg/kg/day) or vehicle for 3 weeks. eNOS phosphorylation on Ser-1177 (positive regulatory site), eNOS interactions with heat-shock protein 90 (HSP90) (positive regulator), phosphorylated AKT (upstream mediator of eNOS phosphorylation on Ser-1177), an NADPH oxidase catalytic subunit gp91(phox), and a marker of oxidative stress (4-hydroxy-2-nonenal [HNE]) were measured by Western blot. Main Outcome Measures Effect of continuous sildenafil treatment on eNOS posttranslational activation, NADPH oxidase catalytic subunit, and oxidative stress in the penis of the sickle cell mouse. Results Continuous treatment with sildenafil reversed (P < 0.05) the abnormalities in protein expressions of P-eNOS (Ser-1177), eNOS/HSP90 interaction, P-AKT, protein expression of gp91(phox), and 4-HNE, in the sickle cell mouse penis. Sildenafil treatment of WT mice did not affect any of these parameters. Conclusion Our findings that sildenafil enhances eNOS activation and inhibits NADPH oxidase function in the sickle cell mouse penis offers a vasculoprotective molecular basis for the therapeutic effect of sildenafil in the penis in association with SCD. PMID:24251665

  19. Sildenafil promotes eNOS activation and inhibits NADPH oxidase in the transgenic sickle cell mouse penis.

    PubMed

    Musicki, Biljana; Bivalacqua, Trinity J; Champion, Hunter C; Burnett, Arthur L

    2014-02-01

    Sickle cell disease (SCD)-associated vasculopathy in the penis is characterized by aberrant nitric oxide and phosphodiesterase (PDE) 5 signaling, and by increased oxidative stress. Preliminary clinical trials show that continuous treatment with PDE5 inhibitor sildenafil unassociated with sexual activity decreases priapic activity in patients with SCD. However, the mechanism of its vasculoprotective effect in the penis remains unclear. We evaluated whether continuous administration of PDE5 inhibitor sildenafil promotes eNOS function at posttranslational levels and decreases superoxide-producing enzyme NADPH oxidase activity in the sickle cell mouse penis. SCD transgenic mice were used as an animal model of SCD. WT mice served as controls. Mice received treatment with the PDE5 inhibitor sildenafil (100 mg/kg/day) or vehicle for 3 weeks. eNOS phosphorylation on Ser-1177 (positive regulatory site), eNOS interactions with heat-shock protein 90 (HSP90) (positive regulator), phosphorylated AKT (upstream mediator of eNOS phosphorylation on Ser-1177), an NADPH oxidase catalytic subunit gp91(phox), and a marker of oxidative stress (4-hydroxy-2-nonenal [HNE]) were measured by Western blot. Effect of continuous sildenafil treatment on eNOS posttranslational activation, NADPH oxidase catalytic subunit, and oxidative stress in the penis of the sickle cell mouse. Continuous treatment with sildenafil reversed (P < 0.05) the abnormalities in protein expressions of P-eNOS (Ser-1177), eNOS/HSP90 interaction, P-AKT, protein expression of gp91(phox), and 4-HNE, in the sickle cell mouse penis. Sildenafil treatment of WT mice did not affect any of these parameters. Our findings that sildenafil enhances eNOS activation and inhibits NADPH oxidase function in the sickle cell mouse penis offers a vasculoprotective molecular basis for the therapeutic effect of sildenafil in the penis in association with SCD. © 2013 International Society for Sexual Medicine.

  20. Interaction of AR and iNOS in lens epithelial cell: A new pathogenesis and potential therapeutic targets of diabetic cataract.

    PubMed

    Li, Xue; Liu, Wenping; Huang, Xinduo; Xiong, Jianping; Wei, Xiaoyong

    2017-02-01

    Although there is significant interest in revealing the role of aldose reductase (AR) and inducible nitric oxide synthase (iNOS) in diabetic cataract (DC), the interaction of AR and iNOS remains unknown. The aim of this study is to investigate the pathogenesis mechanisms and explore as a new potential therapeutic targets for DC. This study investigated the interaction of AR-iNOS through the methods of enzyme kinetics, molecular docking and molecular dynamics simulation, co-immunoprecipitation and fluorescence resonance energy transfer (FRET). The IC50 of AR for inhibition of iNOS activity is 0.04 μM, and the IC50 of iNOS for inhibition of AR activity is 0.042 μM through enzyme kinetics; the interface showed that ARG99 on AR and GLU317 on iNOS played the key roles in the interaction of AR-iNOS predicted by molecular docking and molecular dynamics simulation. Co-immunoprecipitation of protein complexes in human lens epithelial cell (HLEC) demonstrated that AR could association with iNOS in cell; and the interaction distance of AR-iNOS was 6.50 ± 0.22 nm detected by FRET. This study exhibited a direct inhibition interaction between AR and iNOS in HLECs. It is the first report of inhibition interaction between AR and iNOS, suggesting a new pathophysiological mechanism and providing a new insight into the therapeutic mechanism of DC. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. l-Arginine normalizes NOS activity and zinc-MT homeostasis in the kidney of mice chronically exposed to inorganic mercury.

    PubMed

    Piacenza, Francesco; Malavolta, Marco; Cipriano, Catia; Costarelli, Laura; Giacconi, Robertina; Muti, Elisa; Tesei, Silvia; Pierpaoli, Sara; Basso, Andrea; Bracci, Massimo; Bonacucina, Viviana; Santarelli, Lory; Mocchegiani, Eugenio

    2009-09-28

    Inorganic mercury (HgCl2) exposure provokes damage in many organs, especially kidney. Inducible nitric oxide synthase (iNOS) expression, total NOS activity and the profiles of zinc (Zn), copper (Cu) and Hg as well as their distribution when bound to specific intracellular proteins, including metallothioneins (MT), were studied during HgCl2 exposure and after l-arginine treatment in C57BL/6 mouse kidney. HgCl2 exposure modulates differently iNOS expression and NOS activity, increasing iNOS expression but, conversely, decreasing total NOS activity in the mouse kidney. Moreover, during Hg exposure an increased MT production occurs. The kidney damage leads to a loss of urinary proteins, increased plasma creatinine and high Zn mobilization with consequent increased urinary Zn excretion. l-arginine treatment recovers NOS activity and induces a normalization of MT induction, plasma creatinine values and urinary proteins excretion, suggesting that l-arginine may limit kidney damages by Hg exposure.

  2. 75 FR 5061 - Commission Information Collection Activities (FERC Form Nos. 6 and 6-Q); Comment Request; Extensions

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-01

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket Nos. IC10-6-000 and IC10-6Q-000] Commission Information Collection Activities (FERC Form Nos. 6 and 6-Q); Comment Request; Extensions January... to Docket Nos. IC10-6-000 and IC10-6Q-000. For comments that only pertain to one of the collections...

  3. Nitric oxide synthase 2 (NOS2) expression in histologically normal margins of oral squamous cell carcinoma

    PubMed Central

    Itoiz, María E.; Guiñazú, Natalia; Piccini, Daniel; Gea, Susana; López-de Blanc, Silvia

    2014-01-01

    The activity of Nitric Oxide Synthase 2 (NOS2) was found in oral squamous cell carcinomas (OSCC) but not in normal mucosa. Molecular changes associated to early carcinogenesis have been found in mucosa near carcinomas, which is considered a model to study field cancerization. The aim of the present study is to analyze NOS2 expression at the histologically normal margins of OSCC. Study Design: Eleven biopsy specimens of OSCC containing histologically normal margins (HNM) were analyzed. Ten biopsies of normal oral mucosa were used as controls. The activity of NOS2 was determined by immunohistochemistry. Salivary nitrate and nitrite as well as tobacco and alcohol consumption were also analyzed. The Chi-squared test was applied. Results: Six out of the eleven HNM from carcinoma samples showed positive NOS2 activity whereas all the control group samples yielded negative (p=0.005). No statistically significant association between enzyme expression and tobacco and/or alcohol consumption and salivary nitrate and nitrite was found. Conclusions: NOS2 expression would be an additional evidence of alterations that may occur in a state of field cancerization before the appearance of potentially malignant morphological changes. Key words:Field cancerization, oral squamous cell carcinoma, Nitric Oxide Synthase 2 (NOS2), malignity markers. PMID:24316703

  4. Converging evidence for an impact of a functional NOS gene variation on anxiety-related processes.

    PubMed

    Kuhn, Manuel; Haaker, Jan; Glotzbach-Schoon, Evelyn; Schümann, Dirk; Andreatta, Marta; Mechias, Marie-Luise; Raczka, Karolina; Gartmann, Nina; Büchel, Christian; Mühlberger, Andreas; Pauli, Paul; Reif, Andreas; Kalisch, Raffael; Lonsdorf, Tina B

    2016-05-01

    Being a complex phenotype with substantial heritability, anxiety and related phenotypes are characterized by a complex polygenic basis. Thereby, one candidate pathway is neuronal nitric oxide (NO) signaling, and accordingly, rodent studies have identified NO synthase (NOS-I), encoded by NOS1, as a strong molecular candidate for modulating anxiety and hippocampus-dependent learning processes. Using a multi-dimensional and -methodological replication approach, we investigated the impact of a functional promoter polymorphism (NOS1-ex1f-VNTR) on human anxiety-related phenotypes in a total of 1019 healthy controls in five different studies. Homozygous carriers of the NOS1-ex1f short-allele displayed enhanced trait anxiety, worrying and depression scores. Furthermore, short-allele carriers were characterized by increased anxious apprehension during contextual fear conditioning. While autonomous measures (fear-potentiated startle) provided only suggestive evidence for a modulatory role of NOS1-ex1f-VNTR on (contextual) fear conditioning processes, neural activation at the amygdala/anterior hippocampus junction was significantly increased in short-allele carriers during context conditioning. Notably, this could not be attributed to morphological differences. In accordance with data from a plethora of rodent studies, we here provide converging evidence from behavioral, subjective, psychophysiological and neuroimaging studies in large human cohorts that NOS-I plays an important role in anxious apprehension but provide only limited evidence for a role in (contextual) fear conditioning. © The Author (2016). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  5. Changes Observed in Views of Nature of Science During a Historically Based Unit

    NASA Astrophysics Data System (ADS)

    Rudge, David Wÿss; Cassidy, David Paul; Fulford, Janice Marie; Howe, Eric Michael

    2014-09-01

    Numerous empirical studies have provided evidence of the effectiveness of an explicit and reflective approach to the learning of issues associated with the nature of science (NOS) (c.f. Abd-El-Khalick and Lederman in J Res Sci Teach 37(10):1057-1095, 2000). This essay reports the results of a mixed-methods association study involving 130 preservice teachers during the course of a three class unit based upon the history of science using such an approach. Within the unit the phenomenon of industrial melanism was presented as a puzzle for students to solve. Students were explicitly asked to reflect upon several NOS issues as they developed and tested their own explanations for the "mystery phenomenon". NOS views of all participants were characterized by means of surveys and follow-up interviews with a subsample of 17 participants, using a modified version of the VNOS protocol (c.f. Lederman et al. in J Res Sci Teach 39(6):497-521, 2002). An analysis of the survey results informed by the interview data suggests NOS views became more sophisticated for some issues, e.g., whether scientific knowledge requires experimentation; but not others, e.g., why scientists experiment. An examination of the interview data informed by our experiences with the unit provides insight into why the unit may have been more effective with regard to some issues than others. This includes evidence that greater sophistication of some NOS issues was fostered by the use of multiple, contextualized examples. The essay concludes with a discussion of limitations, pedagogical implications, and avenues for further research.

  6. Nitrous oxide discretely up-regulates nNOS and p53 in neonatal rat brain.

    PubMed

    Cattano, D; Valleggi, S; Abramo, A; Forfori, F; Maze, M; Giunta, F

    2010-06-01

    Animal studies suggest that neuronal cell death often results from anesthetic administration during synaptogenesis. Volatile anesthetics are strongly involved in triggering neuronal apoptosis, whereas other inhalational agents (xenon) demonstrate protective effects. Nitrous oxide (N2O) has modest pro-apoptotic effects on its own and potent, synergistic toxic effects when combined with volatile agents. Recent findings suggest that, during periods of rapid brain development, the enhanced neurodegeneration triggered by anesthetic drugs may be caused by a compensatory increase in intracellular free calcium, a potent activator of neuronal nitric oxide synthase (nNOS). Anesthesia-induced neuro-apoptosis is also activated via the intrinsic and the extrinsic apoptotic pathways because both pathways involve p53, a key regulatory gene. The molecular events related to neuronal cell apoptosis are not completely understood. To gain further insight into the events underlying neuro-apoptosis, we analyzed the transcriptional consequences of N2O exposure on nNOS, iNOS and p53 mRNA levels. The study used 2 groups of postnatal day seven Sprague/Dawley rats (N=6 each) that were exposed for 120 minutes to air (75% N2, 25% O2) or N2O (75% N2O, 25% O2; this N2O concentration is commonly used to induce anesthesia and has been demonstrated to trigger neurodegeneration in postnatal day seven rats). Total RNA was isolated from each brain and expression analyses on iNOS and nNOS transcripts were performed using relative Real-Time C-reactive protein PCR (using G3PDH as a housekeeping gene). A semi-quantitative RT-PCR analysis was performed on the p53 transcript (using Ciclophylin A as a housekeeping gene). Statistical analysis (REST 2005) revealed a significant, 11-fold up-regulation (P=0.026) of the nNOS transcript but no significant changes in iNOS transcription. The p53 mRNA was up-regulated almost 2-fold (P=0.0002; Student's t-Test; GraphPad Prism 4.00) in N2O-treated samples relative to

  7. History of Science as an Instructional Context: Student Learning in Genetics and Nature of Science

    NASA Astrophysics Data System (ADS)

    Kim, Sun Young; Irving, Karen E.

    2010-02-01

    This study (1) explores the effectiveness of the contextualized history of science on student learning of nature of science (NOS) and genetics content knowledge (GCK), especially interrelationships among various genetics concepts, in high school biology classrooms; (2) provides an exemplar for teachers on how to utilize history of science in genetics instruction; and (3) suggests a modified concept mapping assessment tool for both NOS and GCK. A quasi-experimental control group research design was utilized with pretests, posttests, and delayed posttests, combining qualitative data and quantitative data. The experimental group was taught with historical curricular lessons, while the control group was taught with non-historical curricular lessons. The results indicated that students in the experimental group developed better understanding in targeted aspects of NOS immediately after the intervention and retained their learning 2 months after the intervention. Both groups developed similar genetics knowledge in the posttest, and revealed a slight decay in their understanding in the delayed posttest.

  8. Student Conceptualizations of the Nature of Science in Response to a Socioscientific Issue. Research Report

    ERIC Educational Resources Information Center

    Sadler, Troy D.; Chambers, William F.; Zeidler, Dana L.

    2004-01-01

    This study investigates student conceptualizations of the nature of science (NOS) and how students interpret and evaluate conflicting evidence regarding a socioscientific issue. Eighty-four high school students participated in the study by reading contradictory reports about the status of global warming and responding to questions designed to…

  9. Turkish Grade 10 Students' and Science Teachers' Conceptions of Nature of Science: A National Study

    ERIC Educational Resources Information Center

    Dogan, Nihal; Abd-El-Khalick, Fouad

    2008-01-01

    This study aimed to assess grade 10 Turkish students' and science teachers' conceptions of nature of science (NOS) and whether these conceptions were related to selected variables. These variables included participants' gender, geographical region, and the socioeconomic status (SES) of their city and region; teacher disciplinary background, years…

  10. Induction of expression of iNOS by N-nitrosodimethylamine (NDMA) in human leukocytes.

    PubMed

    Ratajczak-Wrona, Wioletta; Jablonska, Ewa; Jablonski, Jakub; Marcinczyk, Magdalena

    2009-01-01

    The aim of this study was to assess the influence of N-nitrosodimethylamine (NDMA) on expression of inducible nitric oxide synthase (iNOS), as well as production of nitric oxide (NO) and cyclic guanosine monophosphate (cGMP) by human neutrophils (PMN) and peripheral blood mononuclear cells (PBMC), and the participation of the p38 MAPK kinase in this process. Furthermore, the ability of neutrophils to release superoxide anion was determined. The influence of N-nitrosodimethylamine on iNOS expression was determined in isolated PMN and PBMC cells from peripheral blood of healthy individuals. The mononuclear cells showed higher sensitivity to NDMA. Moreover, cytotoxic effect of NDMA can be influenced in some way by the impact of this xenobiotic on nitric oxide and superoxide anion release from human leukocytes. Furthermore, increased generation of these radicals by human leukocytes suggest that neutrophils and mononuclear cells that are exposed to NDMA activity can play a key role in endogenous NDMA generation. However the relationship between iNOS expression and phospho-p38 MAPK in neutrophils and mononuclear cells shows that p38 MAPK pathway participates in induction of iNOS expression in the presence of NDMA.

  11. Changes Observed in Views of Nature of Science during a Historically Based Unit

    ERIC Educational Resources Information Center

    Rudge, David Wÿss; Cassidy, David Paul; Fulford, Janice Marie; Howe, Eric Michael

    2014-01-01

    Numerous empirical studies have provided evidence of the effectiveness of an explicit and reflective approach to the learning of issues associated with the nature of science (NOS) (c.f. Abd-El-Khalick and Lederman in "J Res Sci Teach" 37(10):1057-1095, 2000). This essay reports the results of a mixed-methods association study involving…

  12. Discrimination between cocaine-associated context and cue in a modified conditioned place preference paradigm: role of the nNOS gene in cue conditioning.

    PubMed

    Itzhak, Yossef; Roger-Sánchez, Concepción; Kelley, Jonathan B; Anderson, Karen L

    2010-03-01

    The conditioned place preference (CPP) paradigm entails appetitive learning and is utilized to investigate the motivational effects of drug and natural reward in rodents. However, a typical CPP design does not allow dissociation between cue- and context-dependent appetitive learning. In humans, context and cues that had been associated with drug reward can elicit conditioned response and drug craving. Therefore, we investigated (a) methods by which to discriminate between cue- and context-dependent appetitive learning, and (b) the role of the neuronal nitric oxide synthase (nNOS) gene in appetitive learning. Wild-type (WT) and nNOS knockout (KO) mice were trained by cocaine (20 mg/kg) in a discrete context paired with a light cue (a compound context-cue stimulus). In test 1, approach behaviour to either the training context or to the cue in a novel context was determined. WT mice showed robust preference for both cocaine-associated context and cue. nNOS KO mice acquired approach behaviour for the cocaine-associated context but not cue. This finding suggests that the nNOS gene is required for cue-dependent appetitive learning. On the following day (test 2), mice were tested for approach behaviour to the compound context-cue stimulus. Context but not cue exposure in test 1 reduced approach behaviour to the compound context-cue stimulus in test 2, suggesting that repeated context but not cue exposures diminished the conditioned response. Hence, this modified CPP paradigm is useful for the investigation of approach behaviour for both drug-associated context and cue, and allows further investigation of mechanisms underlying cue- and context-dependent appetitive learning.

  13. Genetic polymorphisms of eNOS, hormone receptor status, and survival of breast cancer.

    PubMed

    Choi, Ji-Yeob; Lee, Kyoung-Mu; Noh, Dong-Young; Ahn, Sei-Hyun; Lee, Jong-Eun; Han, Wonshik; Jang, In-Jin; Shin, Sang-Goo; Yoo, Keun-Young; Hayes, Richard B; Kang, Daehee

    2006-11-01

    The endothelial cell-specific form of nitric oxide synthase (eNOS) may play an important role in tumor progression via angiogenesis or apoptosis. We studied eNOS -786T > C and 894G > T (Glu298Asp), two functionally significant SNPs, in relation to hazard of breast cancer recurrence or death in 873 women with incident, non-metastatic breast cancer, recruited from two teaching hospitals in Seoul, Korea, 1995-2002. Hazards were estimated by Cox proportional hazard models, in relation to genotype, adjusting for hormone receptor status, lymph node involvement, and tumor size. Women carriers of the eNOS -786C allele had significantly increased hazards of breast cancer recurrence or death, compared with women having the TT genotype (HR = 2.1, 95% CI = 1.03-4.33); risks increased up to 3-fold in ER positive cases (HR = 3.2, 95% CI = 0.95-10.50). The hazard was also increased in eNOS 894T carriers, however, it did not reach statistical significance (HR = 1.8, 95% CI = 0.85-3.93). The combined genotypes containing -786C or 894T was associated with a 2.5-fold risk, compared to the TT-GG genotypes, the most dominant genotype combination (95% CI = 1.29-4.68), with the greatest risks in ER positive cases (HR = 4.9, 95% CI = 1.31-18.36). These results indicate that the eNOS -786C polymorphism, and possibly the 894T polymorphism, are associated with breast cancer recurrence and death, particularly in women with ER positive tumors.

  14. Changes in Students' Views about Nature of Scientific Inquiry at a Science Camp

    NASA Astrophysics Data System (ADS)

    Leblebicioglu, G.; Metin, D.; Capkinoglu, E.; Cetin, P. S.; Eroglu Dogan, E.; Schwartz, R.

    2017-12-01

    Although nature of science (NOS) and nature of scientific inquiry (NOSI) are related to each other, they are differentiated as NOS is being more related to the product of scientific inquiry (SI) which is scientific knowledge whereas NOSI is more related to the process of SI (Schwartz et al. 2008). Lederman et al. (Journal of Research in Science Teaching, 51, 65-8, 2014) determined eight NOSI aspects for K-16 context. In this study, a science camp was conducted to teach scientific inquiry (SI) and NOSI to 24 6th and 7th graders (16 girls and 8 boys). The core of the program was guided inquiry in nature. The children working in small groups under guidance of science advisors conducted four guided-inquiries in the nature in morning sessions on nearby plants, animals, water, and soil. NOSI aspects were made explicit during and at the end of each inquiry session. Views about scientific inquiry (VASI) (Lederman et al. Journal of Research in Science Teaching, 51, 65-8, 2014) questionnaire was applied as pre- and post-test. The results of the study showed that children developed in all eight NOSI aspects, but higher developments were observed in "scientific investigations all begin with a question" and "there is no single scientific method," and "explanations are developed from data and what is already known" aspects. It was concluded that the science camp program was effective in teaching NOSI.

  15. Changes in Students' Views about Nature of Scientific Inquiry at a Science Camp

    NASA Astrophysics Data System (ADS)

    Leblebicioglu, G.; Metin, D.; Capkinoglu, E.; Cetin, P. S.; Eroglu Dogan, E.; Schwartz, R.

    2017-11-01

    Although nature of science (NOS) and nature of scientific inquiry (NOSI) are related to each other, they are differentiated as NOS is being more related to the product of scientific inquiry (SI) which is scientific knowledge whereas NOSI is more related to the process of SI (Schwartz et al. 2008). Lederman et al. ( Journal of Research in Science Teaching, 51, 65-8, 2014) determined eight NOSI aspects for K-16 context. In this study, a science camp was conducted to teach scientific inquiry (SI) and NOSI to 24 6th and 7th graders (16 girls and 8 boys). The core of the program was guided inquiry in nature. The children working in small groups under guidance of science advisors conducted four guided-inquiries in the nature in morning sessions on nearby plants, animals, water, and soil. NOSI aspects were made explicit during and at the end of each inquiry session. Views about scientific inquiry (VASI) (Lederman et al. Journal of Research in Science Teaching, 51, 65-8, 2014) questionnaire was applied as pre- and post-test. The results of the study showed that children developed in all eight NOSI aspects, but higher developments were observed in "scientific investigations all begin with a question" and "there is no single scientific method," and "explanations are developed from data and what is already known" aspects. It was concluded that the science camp program was effective in teaching NOSI.

  16. Induction of iNOS in human monocytes infected with different Legionella species.

    PubMed

    Neumeister, B; Bach, V; Faigle, M; Northoff, H

    2001-08-07

    The contribution of nitric oxide (NO) radicals to the suppression of intracellular replication of Legionella has been well established in rodents but remained questionable in humans. Considering the fact that human monocytes do not exhibit a high-output NO production, we used sensitive methods such as detection of inducible NO synthase (iNOS) mRNA by reverse transcription-PCR and demonstration of iNOS protein expression by means of flow cytometry and Western blot to compare the levels of iNOS induced by Legionella species which, in accordance to their human prevalence, show different multiplication rates within human monocytic cells. The expression of iNOS in Mono Mac 6 (MM6) cells showed an only moderate inverse correlation to the intracellular replication rate of a given Legionella species in the protein expression assays. However, stimulation of host cells with 1,25-dihydroxyvitamin D(3) to enhance NO production and inhibition of NO production by treatment of host cells with N(G)-methyl-L-arginine were not able to modify the intracellular multiplication of legionellae within MM6 cells. Therefore, NO production does not seem to play a crucial role for the restriction of intracellular replication of Legionella bacteria within human monocytic cells. Rodent models in investigations which are supposed to clarify the involvement of NO radicals in defense mechanisms against Legionella infections in humans are of doubtful significance.

  17. NOS3 genotype-dependent correlation between blood pressure and physical activity.

    PubMed

    Kimura, Tomomi; Yokoyama, Tetsuji; Matsumura, Yasuhiro; Yoshiike, Nobuo; Date, Chigusa; Muramatsu, Masaaki; Tanaka, Heizo

    2003-02-01

    Endothelium-dependent vasorelaxation plays an important role in reduction of blood pressure and is mediated through release of nitric oxide (NO), which is generated by constitutively expressed endothelial nitric oxide synthase (NOS3). Exercise also augments NO release and has been recommended for primary prevention and improvement of hypertension, but individual responses are highly variable. We therefore postulated that genetic polymorphisms of NOS3 might interact with physical activity level to differentially influence blood pressure level. We genotyped 832 healthy Japanese (mean age of 54.4+/-8.6 years, 372 men and 460 women) for a polymorphism of NOS3 in intron 4 (ecNOS4a/b), using the polymerase chain reaction method, and scored their habitual physical activity level by using the rate of energy expenditure per resting metabolic rate through an interview according to a semiquantitative assessment method. Only in the subjects who had the rarer a allele (aa+ba type), systolic blood pressure was found to be inversely correlated with physical activity level (P for linear trend=0.0496, for interaction=0.0071). Eventually, this polymorphism was significantly associated with the prevalence of systolic hypertension only in the subjects who were in the lowest tertile of physical activity level (OR=2.4, 95% CI, 1.1 to 5.6, P for interaction=0.0474). In the present study, we found a significant interaction between the genotype and physical activity level on systolic blood pressure. These results might allow a better understanding of the mechanism to improve hypertension by exercise and to thereby reduce the risk of cardiovascular disease.

  18. The NosX and NirX Proteins of Paracoccus denitrificans Are Functional Homologues: Their Role in Maturation of Nitrous Oxide Reductase

    PubMed Central

    Saunders, Neil F. W.; Hornberg, Jorrit J.; Reijnders, Willem N. M.; Westerhoff, Hans V.; de Vries, Simon; van Spanning, Rob J. M.

    2000-01-01

    The nos (nitrous oxide reductase) operon of Paracoccus denitrificans contains a nosX gene homologous to those found in the nos operons of other denitrifiers. NosX is also homologous to NirX, which is so far unique to P. denitrificans. Single mutations of these genes did not result in any apparent phenotype, but a double nosX nirX mutant was unable to reduce nitrous oxide. Promoter-lacZ assays and immunoblotting against nitrous oxide reductase showed that the defect was not due to failure of expression of nosZ, the structural gene for nitrous oxide reductase. Electron paramagnetic resonance spectroscopy showed that nitrous oxide reductase in cells of the double mutant lacked the CuA center. A twin-arginine motif in both NosX and NirX suggests that the NosX proteins are exported to the periplasm via the TAT translocon. PMID:10960107

  19. NOS1-derived nitric oxide promotes NF-κB transcriptional activity through inhibition of suppressor of cytokine signaling-1

    PubMed Central

    Baig, Mirza Saqib; Zaichick, Sofia V.; Mao, Mao; de Abreu, Andre L.; Bakhshi, Farnaz R.; Hart, Peter C.; Saqib, Uzma; Deng, Jing; Chatterjee, Saurabh; Block, Michelle L.; Vogel, Stephen M.; Malik, Asrar B.; Consolaro, Marcia E.L.; Christman, John W.; Minshall, Richard D.

    2015-01-01

    The NF-κB pathway is central to the regulation of inflammation. Here, we demonstrate that the low-output nitric oxide (NO) synthase 1 (NOS1 or nNOS) plays a critical role in the inflammatory response by promoting the activity of NF-κB. Specifically, NOS1-derived NO production in macrophages leads to proteolysis of suppressor of cytokine signaling 1 (SOCS1), alleviating its repression of NF-κB transcriptional activity. As a result, NOS1−/− mice demonstrate reduced cytokine production, lung injury, and mortality when subjected to two different models of sepsis. Isolated NOS1−/− macrophages demonstrate similar defects in proinflammatory transcription on challenge with Gram-negative bacterial LPS. Consistently, we found that activated NOS1−/− macrophages contain increased SOCS1 protein and decreased levels of p65 protein compared with wild-type cells. NOS1-dependent S-nitrosation of SOCS1 impairs its binding to p65 and targets SOCS1 for proteolysis. Treatment of NOS1−/− cells with exogenous NO rescues both SOCS1 degradation and stabilization of p65 protein. Point mutation analysis demonstrated that both Cys147 and Cys179 on SOCS1 are required for its NO-dependent degradation. These findings demonstrate a fundamental role for NOS1-derived NO in regulating TLR4-mediated inflammatory gene transcription, as well as the intensity and duration of the resulting host immune response. PMID:26324446

  20. A noninhibitory mutant of the caveolin-1 scaffolding domain enhances eNOS-derived NO synthesis and vasodilation in mice

    PubMed Central

    Bernatchez, Pascal; Sharma, Arpeeta; Bauer, Philip M.; Marin, Ethan; Sessa, William C.

    2011-01-01

    Aberrant regulation of eNOS and associated NO release are directly linked with various vascular diseases. Caveolin-1 (Cav-1), the main coat protein of caveolae, is highly expressed in endothelial cells. Its scaffolding domain serves as an endogenous negative regulator of eNOS function. Structure-function analysis of Cav-1 has shown that phenylalanine 92 (F92) is critical for the inhibitory actions of Cav-1 toward eNOS. Herein, we show that F92A–Cav-1 and a mutant cell–permeable scaffolding domain peptide called Cavnoxin can increase basal NO release in eNOS-expressing cells. Cavnoxin reduced vascular tone ex vivo and lowered blood pressure in normal mice. In contrast, similar experiments performed with eNOS- or Cav-1–deficient mice showed that the vasodilatory effect of Cavnoxin is abolished in the absence of these gene products, which indicates a high level of eNOS/Cav-1 specificity. Mechanistically, biochemical assays indicated that noninhibitory F92A–Cav-1 and Cavnoxin specifically disrupted the inhibitory actions of endogenous Cav-1 toward eNOS and thereby enhanced basal NO release. Collectively, these data raise the possibility of studying the inhibitory influence of Cav-1 on eNOS without interfering with the other actions of endogenous Cav-1. They also suggest a therapeutic application for regulating the eNOS/Cav-1 interaction in diseases characterized by decreased NO release. PMID:21804187

  1. Phospho-eNOS Ser-1176 is associated with the nucleoli and the Golgi complex in C6 rat glioma cells.

    PubMed

    Klinz, Franz-Josef; Herberg, Natalie; Arnhold, Stefan; Addicks, Klaus; Bloch, Wilhelm

    2007-06-29

    Enzymatic activity of endothelial nitric oxide synthase (eNOS) is controlled by posttranslational modifications, protein-protein interactions, and subcellular localization. For example, N-terminal fatty acid modifications target eNOS to the Golgi complex where it becomes phosphorylated. We show here by immunofluorescence analysis that phospho-eNOS Ser-1176 is enriched in the perinuclear region of interphase C6 rat glioma cells. Confocal double immunofluorescence microscopy with the Golgi marker protein 58K revealed that phospho-eNOS Ser-1176 is associated with the Golgi complex. Surprisingly, we observed several spots in the nucleus of C6 cells that were positive for phospho-eNOS Ser-1176. Confocal double immunofluorescence analysis with the nucleolus marker protein fibrillarin revealed that within the nucleus phospho-eNOS Ser-1176 is exclusively associated with the nucleoli. It is known that in mitotic cells nucleoli are lost during prophase and rebuild during telophase. In agreement with this, we find no nucleoli-like distribution of phospho-eNOS Ser-1176 in metaphase and anaphase C6 glioma cells. Our finding that phospho-eNOS Ser-1176 is selectively associated with the nucleoli points to a so far unknown role for eNOS in interphase glioma cells.

  2. Ellagic acid protects endothelial cells from oxidized low-density lipoprotein-induced apoptosis by modulating the PI3K/Akt/eNOS pathway

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ou, Hsiu-Chung; Lee, Wen-Jane; Tunghai University, Taichung, Taiwan

    Endothelial apoptosis is a driving force in atherosclerosis development. Oxidized low-density lipoprotein (oxLDL) promotes inflammatory and thrombotic processes and is highly atherogenic, as it stimulates macrophage cholesterol accumulation and foam cell formation. Previous studies have shown that the phosphatidylinositol 3-kinase/Akt/endothelial nitric oxide synthase/nitric oxide (PI3K/Akt/eNOS/NO) pathway is involved in oxLDL-induced endothelial apoptosis. Ellagic acid, a natural polyphenol found in berries and nuts, has in recent years been the subject of intense research within the fields of cancer and inflammation. However, its protective effects against oxLDL-induced injury in vascular endothelial cells have not been clarified. In the present study, we investigatedmore » the anti-apoptotic effect of ellagic acid in human umbilical vein endothelial cells (HUVECs) exposed to oxLDL and explored the possible mechanisms. Our results showed that pretreatment with ellagic acid (5-20 {mu}M) significantly attenuated oxLDL-induced cytotoxicity, apoptotic features, and generation of reactive oxygen species (ROS). In addition, the anti-apoptotic effect of ellagic acid was partially inhibited by a PI3K inhibitor (wortmannin) and a specific eNOS inhibitor (cavtratin) but not by an ERK inhibitor (PD98059). In exploring the underlying mechanisms of ellagic acid action, we found that oxLDL decreased Akt and eNOS phosphorylation, which in turn activated NF-{kappa}B and downstream pro-apoptotic signaling events including calcium accumulation, destabilization of mitochondrial permeability, and disruption of the balance between pro- and anti-apoptotic Bcl-2 proteins. Those alterations induced by oxLDL, however, were attenuated by pretreatment with ellagic acid. The inhibition of oxLDL-induced endothelial apoptosis by ellagic acid is due at least in part to its anti-oxidant activity and its ability to modulate the PI3K/Akt/eNOS signaling pathway.« less

  3. Changes in eNOS phosphorylation contribute to increased arteriolar NO release during juvenile growth

    PubMed Central

    Kang, Lori S.; Nurkiewicz, Timothy R.; Wu, Guoyao

    2012-01-01

    Nitric oxide (NO) mediates a major portion of arteriolar endothelium-dependent dilation in adults, but indirect evidence has suggested that NO contributes minimally to these responses in the young. Isolated segments of arterioles were studied in vitro to verify this age-related increase in NO release and investigate the mechanism by which it occurs. Directly measured NO release induced by ACh or the Ca2+ ionophore A-23187 was five- to sixfold higher in gracilis muscle arterioles from 42- to 46-day-old (juvenile) rats than in those from 25- to 28-day-old (weanling) rats. There were no differences between groups in arteriolar endothelial NO synthase (eNOS) expression or tetrahydrobiopterin levels, and arteriolar l-arginine levels were lower in juvenile vessels than in weanling vessels (104 ± 6 vs.126 ± 3 pmol/mg). In contrast, agonist-induced eNOS Thr495 dephosphorylation and eNOS Ser1177 phosphorylation (events required for maximal activity) were up to 30% and 65% greater, respectively, in juvenile vessels. Juvenile vessels did not show increased expression of enzymes that mediate these events [protein phosphatases 1 and 2A and PKA and PKB (Akt)] or heat shock protein 90, which facilitates Ser1177 phosphorylation. However, agonist-induced colocalization of heat shock protein 90 with eNOS was 34–66% greater in juvenile vessels than in weanling vessels, and abolition of this difference with geldanamycin also abolished the difference in Ser1177 phosphorylation between groups. These findings suggest that growth-related increases in arteriolar NO bioavailability may be due at least partially to changes in the regulation of eNOS phosphorylation and increased signaling activity, with no change in the abundance of eNOS signaling proteins. PMID:22140037

  4. Changing epistemological beliefs with nature of science implementations

    NASA Astrophysics Data System (ADS)

    Johnson, Keith; Willoughby, Shannon

    2018-06-01

    This article discusses our investigation regarding nature of science (NOS) implementations and epistemological beliefs within an undergraduate introductory astronomy course. The five year study consists of two years of baseline data in which no explicit use of NOS material was implemented, then three years of subsequent data in which specific NOS material was integrated into the classroom. Our original study covered two years of baseline data and one year of treatment data. Two additional years of treatment course data have revealed intriguing new insights into our students' epistemic belief structure. To monitor the evolution of belief structures across each semester we used student pre-post data on the Epistemological Beliefs About the Physical Sciences (EBAPS) assessment. The collected data were also partitioned and analyzed according to the following variables: college (Letters of Science, Business, Education, etc.), degree (BA or BS), status (freshman, sophomore, etc.), and gender (male or female). We find that the treatment course no longer undergoes significant overall epistemic deterioration after a semester of instruction. We also acquire a more detailed analysis of these findings utilizing the aforementioned variables. Most notably, we see that this intervention had a pronounced positive impact on males and on students within the college of Education, Arts & Architecture, and those with no concentration. Lastly, whether or not students believe their ability to learn science is innate or malleable did not seem to change, remaining a rigid construct with student epistemologies.

  5. Comparing Scientists' Views of Nature of Science within and across Disciplines, and Levels of Expertise

    ERIC Educational Resources Information Center

    Tira, Praweena

    2009-01-01

    The purpose of this study was to understand how Thai scientists from four disciplines viewed nature of science (NOS). The sixteen participating scientists were chosen from the areas of chemistry, physics, biology/life sciences, and geology/earth sciences and were separated into novice and expert groups. The scientists' understandings about NOS…

  6. History of Science as an Instructional Context: Student Learning in Genetics and Nature of Science

    ERIC Educational Resources Information Center

    Kim, Sun Young; Irving, Karen E.

    2010-01-01

    This study (1) explores the effectiveness of the contextualized history of science on student learning of nature of science (NOS) and genetics content knowledge (GCK), especially interrelationships among various genetics concepts, in high school biology classrooms; (2) provides an exemplar for teachers on how to utilize history of science in…

  7. Science Teachers' Thinking about the Nature of Science: A New Methodological Approach to Its Assessment

    ERIC Educational Resources Information Center

    Vazquez-Alonso, Angel; Garcia-Carmona, Antonio; Manassero-Mas, Maria Antonia; Bennassar-Roig, Antoni

    2013-01-01

    This paper describes Spanish science teachers' thinking about issues concerning the nature of science (NOS) and the relationships connecting science, technology, and society (STS). The sample consisted of 774 in-service and pre-service teachers. The participants responded to a selection of items from the Questionnaire of Opinions on Science,…

  8. Investigating the Relationship between Teachers' Nature of Science Conceptions and Their Practice of Inquiry Science

    ERIC Educational Resources Information Center

    Atar, Hakan Yavuz; Gallard, Alejandro

    2011-01-01

    In addition to recommending inquiry as the primary approach to teaching science, developers of recent reform efforts in science education have also strongly suggested that teachers develop a sound understanding of the nature of science. Most studies on teachers' NOS conceptions and inquiry beliefs investigated these concepts of teachers' NOS…

  9. How Elementary Teachers' Beliefs About the Nature of Science Mediate Implementing Prescribed Science Curricula in Their Classrooms

    NASA Astrophysics Data System (ADS)

    Giglio, Kathleen Rose Fitzgerald

    This is an in depth study of two elementary school teachers, who are generalists because they teach multiple subjects to their classes, in addition to science, respectively in grade 3 and grade 6. The teachers taught and their students learned using a contemporary understanding of the nature of science (NOS), which they learned by actually doing science investigations, rather than being explicitly told about NOS (contrary to what some scholars claim). Neither teacher completed any formal/informal science training/experiences, especially connected to the construct NOS. Even though the teachers did not explicitly reference NOS in the classroom, their teaching about NOS was made possible through their implementation of the FOSS ( Full Option Science System) curriculum. Although their students enthusiastically demonstrated competence in both science process and content, as prescribed by the FOSS curriculum, the teachers' felt undermined by the state mandated assessments and the inclusion of student performance as a criterion for the state teacher evaluation system. This research was designed to answer the following questions: (1) What are elementary teachers' conceptions about NOS? (2) How are the teachers' NOS views manifested in their implementation of the FOSS program and their choices of instructional methods/materials? (3) What factors may have enhanced or hindered how the teachers sustained their NOS conceptions as they implemented the FOSS program? To explicate the relationship between teachers' views of NOS and the extent to which constructivist practices were employed in their science instruction, a multiple research methodology using grounded theory as the foundation and employing both quantitative and qualitative measures, was needed. Sources of quantitative data were written survey results using the Student Understanding of Science and Scientific Inquiry Questionnaire (SUSSI; Liang et al., 2008) Likert scale responses and constructed responses. Face

  10. Cooperative Learning about Nature of Science with a Case from the History of Science

    ERIC Educational Resources Information Center

    Wolfensberger, Balz; Canella, Claudia

    2015-01-01

    This paper reports a predominantly qualitative classroom study on cooperative learning about nature of science (NOS) using a case from the history of science. The purpose of the research was to gain insight into how students worked with the historical case study during cooperative group work, how students and teachers assessed the teaching unit,…

  11. Argumentation, Critical Thinking, Nature of Science and Socioscientific Issues: A Dialogue between Two Researchers

    ERIC Educational Resources Information Center

    Yacoubian, Hagop A.; Khishfe, Rola

    2018-01-01

    The purpose of this paper is to compare and contrast between two theoretical frameworks for addressing nature of science (NOS) and socioscientific issues (SSI) in school science. These frameworks are critical thinking (CT) and argumentation (AR). For the past years, the first and second authors of this paper have pursued research in this area…

  12. VIEW OF NOS. 217 AND 219 WASHINGTON AVENUE LOOKING NORTHEAST, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF NOS. 217 AND 219 WASHINGTON AVENUE LOOKING NORTHEAST, SHOWING WEST FACADES - Apollo Iron & Steel Works, Company Housing, West of Washington & Lincoln Avenues, Vandergrift, Westmoreland County, PA

  13. Evaluating Instrument Quality in Science Education: Rasch-based analyses of a Nature of Science test

    NASA Astrophysics Data System (ADS)

    Neumann, Irene; Neumann, Knut; Nehm, Ross

    2011-07-01

    Given the central importance of the Nature of Science (NOS) and Scientific Inquiry (SI) in national and international science standards and science learning, empirical support for the theoretical delineation of these constructs is of considerable significance. Furthermore, tests of the effects of varying magnitudes of NOS knowledge on domain-specific science understanding and belief require the application of instruments validated in accordance with AERA, APA, and NCME assessment standards. Our study explores three interrelated aspects of a recently developed NOS instrument: (1) validity and reliability; (2) instrument dimensionality; and (3) item scales, properties, and qualities within the context of Classical Test Theory and Item Response Theory (Rasch modeling). A construct analysis revealed that the instrument did not match published operationalizations of NOS concepts. Rasch analysis of the original instrument-as well as a reduced item set-indicated that a two-dimensional Rasch model fit significantly better than a one-dimensional model in both cases. Thus, our study revealed that NOS and SI are supported as two separate dimensions, corroborating theoretical distinctions in the literature. To identify items with unacceptable fit values, item quality analyses were used. A Wright Map revealed that few items sufficiently distinguished high performers in the sample and excessive numbers of items were present at the low end of the performance scale. Overall, our study outlines an approach for how Rasch modeling may be used to evaluate and improve Likert-type instruments in science education.

  14. Influence of Nature and History of Science Courses on Value Perceptions of Elementary Science Teacher Candidates in Conceptual Dimension in Turkey

    ERIC Educational Resources Information Center

    Aktamis, Hilal; Higde, Emrah

    2018-01-01

    This study aimed to determine the changes in understanding about the nature of science (NOS) and conceptual values of 28 elementary science teacher candidates who engaged in the instruction of the nature and history of science (NHOS). A values scale was used to determine the values of science teacher candidates in six areas of the conceptual…

  15. Association of a NOS3 gene polymorphism with Behçet's disease but not with Vogt-Koyanagi-Harada syndrome in Han Chinese.

    PubMed

    Zhou, Yan; Yu, Hongsong; Hou, Shengping; Fang, Jing; Qin, Jieying; Yuan, Gangxiang; Kijlstra, Aize; Yang, Peizeng

    2016-01-01

    Previous studies have identified that nitric oxide synthase (NOS) genes are associated with several immune-mediated diseases. This study aimed to investigate whether NOS2 and NOS3 gene polymorphisms are associated with Behçet's disease (BD) and Vogt-Koyanagi-Harada (VKH) syndrome in a Han Chinese population. An association analysis of NOS2/rs4795067, NOS3/rs1799983 and NOS3/rs1800779 was performed in 733 patients with BD, 800 patients with VKH syndrome, and 1,359 controls using PCR restriction fragment length polymorphism (PCR-RFLP) assay. Statistical analysis was performed with the chi-square test followed by the Bonferroni correction. The result showed a decreased frequency of the NOS3/rs1799983 GG genotype and an increased frequency of NOS3/rs1799983 GT genotype in the patients with BD (Bonferroni correction test [Pc]=0.02, odds ratio [OR]=0.74; Pc=2.1×10(-3), OR=1.57, respectively). No significant association was found between rs1799983 and VKH syndrome. NOS2/ rs4795067 and NOS3/rs1800779 were not associated with either BD or VKH syndrome. Our findings suggest that a NOS3/rs1799983polymorphism is associated with susceptibility to BD in Han Chinese.

  16. Korean Students' Perceptions of Scientific Practices and Understanding of Nature of Science

    NASA Astrophysics Data System (ADS)

    Yoon, Sae Yeol; Suh, Jee Kyung; Park, Soonhye

    2014-11-01

    Korean students have shown relatively little interest and confidence in learning science, despite being ranked in the top percentile in international evaluations of academic achievement in science such as the Trends in International Mathematics and Science Study. Although research indicates a positive relationship between student perceptions of science and their science learning, this area has not been sufficiently explored in Korea. Particularly, even though both students' perceptions of scientific practice and their understanding of the nature of science (NOS) are influenced by their science learning experiences at schools, little research examines how this perception, understanding, and experience are related to one another. This study aimed to uncover Korean students' perceptions of school scientific practice through exploring their drawings, writings, and responses to questionnaires. Participants were 500 Korean students in 3rd, 7th, and 10th grades who were asked to complete an open-ended questionnaire. The results indicated that Korean students typically viewed school scientific practices as experimental activities or listening to lecture; and that most participants held an insufficient understanding of the NOS. Overall, no significant relationship emerged between students' perceptions of school scientific practice and their understanding of the NOS. Our findings highlight the need to help both teachers and students understand the potential breadth of school scientific practices, beyond simple 'activity mania.' This study also suggests that teachers must balance implicit and explicit instructional approaches to teaching about the NOS through scientific practices in school science contexts.

  17. Interaction Between Neuronal NOS Signaling and Temperature Influences SR Ca2+ Leak:Role of Nitroso-Redox Balance

    PubMed Central

    Dulce, Raul A.; Mayo, Vera; Rangel, Erika B.; Balkan, Wayne; Hare, Joshua M.

    2014-01-01

    Rationale While nitric oxide (NO) signaling modulates cardiac function and excitation-contraction coupling, opposing results due to inconsistent experimental conditions, particularly with respect to temperature, confound the ability to elucidate NO signaling pathways. Here we show that temperature significantly modulates NO effects. Objective Test the hypothesis that temperature profoundly impacts nitroso-redox equilibrium, thereby affecting sarcomeric reticulum (SR) Ca2+ leak. Methods and Results We measured SR Ca2+ leak in cardiomyocytes from wild-type (WT), NO/redox imbalance (NOS1−/−), and hyper S-nitrosylation (GSNOR−/−) mice. In WT cardiomyocytes, SR Ca2+ leak increased as temperature decreased from 37°C to 23°C, whereas, in NOS1−/ −cells, the leak suddenly increased when the temperature surpassed 30°C. GSNOR−/ − cardiomyocytes exhibited low leak throughout the temperature range. Exogenously added NO had a biphasic effect on NOS1−/− cardiomyocytes; reducing leak at 37°C but increasing it at sub-physiologic temperatures. Oxypurinol and Tempol diminished the leak in NOS1−/ − cardiomyocytes. Cooling from 37° to 23°C increased ROS generation in WT but decreased it in NOS1−/− cardiomyocytes. Oxypurinol further reduced ROS generation. At 23°C in WT cells, leak was decreased by tetrahydrobiopterin, an essential NOS cofactor. Cooling significantly increased SR Ca2+ content in NOS1−/− cells but had no effect in WT or GSNOR−/−. Conclusions Ca2+ leak and temperature are normally inversely proportional, whereas NOS1 deficiency reverses this effect, increasing leak and elevating ROS production as temperature increases. Reduced denitrosylation (GSNOR deficiency) eliminates the temperature dependence of leak. Thus, temperature regulates the balance between NO and ROS which in turn has a major impact on SR Ca2+. PMID:25326127

  18. The Mismatch among Students' Views about Nature of Science, Acceptance of Evolution, and Evolutionary Science Understandings

    ERIC Educational Resources Information Center

    Cavallo, Ann M. L.; White, Kevin J.; McCall, David

    2011-01-01

    This study explored interrelationships among high school students' views about nature of science (NOS), acceptance of evolution, and conceptual understanding of evolution, and the extent to which these may have shifted from pre- to post-instruction on evolutionary theory. Eighty-one students enrolled in ninth-grade Biology responded to…

  19. Relationship between Nature of Science Understandings and Argumentation Skills: A Role for Counterargument and Contextual Factors

    ERIC Educational Resources Information Center

    Khishfe, Rola

    2012-01-01

    The study investigated the relationship of high school students' understandings about nature of science (NOS) aspects and their argumentation skills in relation to two controversial socioscientific issues. The study was conducted in five schools selected from different geographical areas in Beirut, Lebanon. Participants were 219 grade 11 students.…

  20. Does inducible NOS have a protective role against hypoxia/reoxygenation injury in rat heart?

    PubMed

    Rus, Alma; del Moral, Maria Luisa; Molina, Francisco; Peinado, Maria Angeles

    2011-01-01

    The present study analyzes the role of the nitric oxide (NO) derived from inducible NO synthase (iNOS) under cardiac hypoxia/reoxygenation situations. For this, we have designed a follow-up study of different parameters of cell and tissue damage in the heart of Wistar rats submitted for 30 min to acute hypobaric hypoxia, with or without prior treatment with the selective iNOS inhibitor N-(3-(aminomethyl)benzyl) acetamidine or 1400W (10 mg/kg). The rats were studied at 0 h, 12 h, and 5 days of reoxygenation, analyzing NO production (NOx), lipid peroxidation, apoptosis, and protein nitration expression and location. This is the first time-course study which analyzes the effects of the iNOS inhibition by 1400W during hypoxia/reoxygenation in the adult rat heart. The results show that when 1400W was administered before the hypoxic episode, NOx levels fell, while both the lipid peroxidation level and the percentage of apoptotic cells rose throughout the reoxygenation period. Levels of nitrated proteins expression fell only at 12 h post-hypoxia. The inhibition of iNOS raises the peroxidative and apoptotic level in the hypoxic heart indicating that this isoform may have a protective effect on this organ against hypoxia/reoxygenation injuries, and challenging the conventional wisdom that iNOS is deleterious under these conditions. These findings could help in the design of new treatments based on NO pharmacology against hypoxia/reoxygenation dysfunctions. Copyright © 2011 Elsevier Inc. All rights reserved.

  1. The role of nNOS and PGC-1α in skeletal muscle cells.

    PubMed

    Baldelli, Sara; Lettieri Barbato, Daniele; Tatulli, Giuseppe; Aquilano, Katia; Ciriolo, Maria Rosa

    2014-11-15

    Neuronal nitric oxide synthase (nNOS) and peroxisome proliferator activated receptor γ co-activator 1α (PGC-1α) are two fundamental factors involved in the regulation of skeletal muscle cell metabolism. nNOS exists as several alternatively spliced variants, each having a specific pattern of subcellular localisation. Nitric oxide (NO) functions as a second messenger in signal transduction pathways that lead to the expression of metabolic genes involved in oxidative metabolism, vasodilatation and skeletal muscle contraction. PGC-1α is a transcriptional coactivator and represents a master regulator of mitochondrial biogenesis by promoting the transcription of mitochondrial genes. PGC-1α can be induced during physical exercise, and it plays a key role in coordinating the oxidation of intracellular fatty acids with mitochondrial remodelling. Several lines of evidence demonstrate that NO could act as a key regulator of PGC-1α expression; however, the link between nNOS and PGC-1α in skeletal muscle remains only poorly understood. In this Commentary, we review important metabolic pathways that are governed by nNOS and PGC-1α, and aim to highlight how they might intersect and cooperatively regulate skeletal muscle mitochondrial and lipid energetic metabolism and contraction. © 2014. Published by The Company of Biologists Ltd.

  2. Ischemic postconditioning provides cardioprotective and antiapoptotic effects against ischemia-reperfusion injury through iNOS inhibition in hyperthyroid rats.

    PubMed

    Zaman, Jalal; Jeddi, Sajad; Daneshpour, Maryam Sadat; Zarkesh, Maryam; Daneshian, Zahra; Ghasemi, Asghar

    2015-10-10

    Ischemic postconditioning (IPost) is a strategy to provide protection against ischemia-reperfusion (IR) injury. The cardioprotective effects of IPost in cases of ischemic heart disease along with co-morbidities like hyperthyroidism remain unknown. The aim of this study was to investigate the effects of IPost on expression of eNOS, iNOS, Bax, and Bcl-2 genes in hyperthyroid male rats, subjected to myocardial IR. Hyperthyroidism was induced by adding thyroxine to drinking water for a period of 21 days. Using the Langendorff device hearts were perfused, then subjected to a 30-minute global ischemia which was followed by 120 min of reperfusion; subsequently IPost was induced immediately after ischemia. Results indicated that following IR, expression of eNOS and Bcl-2 decreased, whereas expression of iNOS and Bax increased in both the control and hyperthyroid groups. In hyperthyroid animals, IPost significantly increased expression of eNOS by 3.19 fold and Bcl-2 by 3.66 fold; it also decreased expression of Bax by 51%, and reduced IR-induced DNA laddering pattern and infarct size (45.7 ± 1.82% vs. 59.3 ± 1.83%, p<0.05) in the presence of aminoguanidine (AG), a selective iNOS inhibitor. In conclusion, IPost per se could not provide cardioprotection against myocardial ischemia in hyperthyroid rats, a loss of which however was restored by the combination of IPost and iNOS inhibition that acts by a decrease in Bax and an increase in both eNOS and Bcl-2 expression. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Expression dynamics of HSP90 and nitric oxide synthase (NOS) isoforms during heat stress acclimation in Tharparkar cattle

    NASA Astrophysics Data System (ADS)

    Bharati, Jaya; Dangi, S. S.; Bag, S.; Maurya, V. P.; Singh, G.; Kumar, P.; Sarkar, M.

    2017-08-01

    Six male Tharparkar cattle of 2-3 years old were selected for the study. After 15-day acclimation at thermoneutral zone (TNZ) in psychrometric chamber, animals were exposed at 42 °C for 6 h up to 23 days followed by 12 days of recovery period. Blood samples were collected during control period at TNZ (days 1, 5, and 12), after heat stress exposure (day 1, immediate heat stress acclimation (IHSA); days 2 to 10, short-term heat stress acclimation (STHSA); days 15 to 23, long-term heat stress acclimation (LTHSA); days 7 and 12, recovery period), and peripheral blood mononuclear cells (PBMCs) were isolated for RNA and protein extraction. The messenger RNA (mRNA) and protein expression in PBMCs were determined by qPCR and western blot, respectively. Samples at TNZ were taken as control. The mRNA expression of HSP90, iNOS, and eNOS was significantly upregulated ( P < 0.05) on day 1 (ISHA) as compared to control, remained consistent during STHSA, again increased during LTHSA, and finally reduced to basal level during recovery period. The protein expression of HSP90, iNOS, and eNOS were akin to their transcript pattern. PBMC culture study was conducted to study transcriptional abundance of HSP90, iNOS, and eNOS at different temperature-time combinations. The present findings indicate that HSP90, iNOS, and eNOS could possibly play an important role in mitigating thermal insults and confer thermotolerance during long-term heat stress exposure in Tharparkar cattle.

  4. Novel cellular targets of AhR underlie alterations in neutrophilic inflammation and iNOS expression during influenza virus infection

    PubMed Central

    Head Wheeler, Jennifer L.; Martin, Kyle C.; Lawrence, B. Paige

    2012-01-01

    The underlying reasons for variable clinical outcomes from respiratory viral infections remain uncertain. Several studies suggest that environmental factors contribute to this variation, but limited knowledge of cellular and molecular targets of these agents hampers our ability to quantify or modify their contribution to disease and improve public health. The aryl hydrocarbon receptor (AhR) is an environment sensing transcription factor that binds many anthropogenic and natural chemicals. The immunomodulatory properties of AhR ligands are best characterized with extensive studies of changes in CD4+ T cell responses. Yet, AhR modulates other aspects of immune function. We previously showed that during influenza virus infection, AhR activation modulates neutrophil accumulation in the lung, and this contributes to increased mortality in mice. Enhanced levels of inducible nitric oxide synthase (iNOS) in infected lungs are observed during the same timeframe as AhR-mediated increased pulmonary neutrophilia. In this study, we evaluated whether these two consequences of AhR activation are causally linked. Reciprocal inhibition of AhR-mediated elevations in iNOS and pulmonary neutrophilia reveal that, although they are contemporaneous, they are not causally related. We show using Cre/loxP technology that elevated iNOS levels and neutrophil number in the infected lung result from separate, AhR-dependent signaling in endothelial and respiratory epithelial cells, respectively. Studies using mutant mice further reveal that AhR-mediated alterations in these innate responses to infection require a functional nuclear localization signal and DNA binding domain. Thus, gene targets of AhR in non-hematopoietic cells are important new considerations for understanding AhR-mediated changes in innate anti-viral immunity. PMID:23233726

  5. Educational Background, Teaching Experience and Teachers' Views on the Inclusion of Nature of Science in the Science Curriculum

    NASA Astrophysics Data System (ADS)

    Martín-Díaz, M. J.

    2006-08-01

    The aim of this research is to ascertain teachers’ opinions on what elements of nature of science (NOS) and science technology society relationships (STS) should be taught in school science. To this end an adapted version of the questionnaire developed by Osborne et al. is used. Our results show that experts consulted by Osborne et al. and Spanish teachers confer similar importance on the provisional, experimental, and predictive nature of scientific knowledge based on some of the procedures used such as the drawing up of hypotheses and the analysis and interpretation of data. We also look into the relationship between the teachers’ views and their educational background.1 Results suggest that philosophy teachers are more concerned with the inclusion of NOS and STS topics in science curricula than science teachers, although further studies will be necessary. Some suggestions concerning the university training of science teachers are also discussed.

  6. Differential HIF and NOS responses to acute anemia: defining organ-specific hemoglobin thresholds for tissue hypoxia.

    PubMed

    Tsui, Albert K Y; Marsden, Philip A; Mazer, C David; Sled, John G; Lee, Keith M; Henkelman, R Mark; Cahill, Lindsay S; Zhou, Yu-Qing; Chan, Neville; Liu, Elaine; Hare, Gregory M T

    2014-07-01

    Tissue hypoxia likely contributes to anemia-induced organ injury and mortality. Severe anemia activates hypoxia-inducible factor (HIF) signaling by hypoxic- and neuronal nitric oxide (NO) synthase- (nNOS) dependent mechanisms. However, organ-specific hemoglobin (Hb) thresholds for increased HIF expression have not been defined. To assess organ-specific Hb thresholds for tissue hypoxia, HIF-α (oxygen-dependent degradation domain, ODD) luciferase mice were hemodiluted to mild, moderate, or severe anemia corresponding to Hb levels of 90, 70, and 50 g/l, respectively. HIF luciferase reporter activity, HIF protein, and HIF-dependent RNA levels were assessed. In the brain, HIF-1α was paradoxically decreased at mild anemia, returned to baseline at moderate anemia, and then increased at severe anemia. Brain HIF-2α remained unchanged at all Hb levels. Both kidney HIF-1α and HIF-2α increased earlier (Hb ∼70-90 g/l) in response to anemia. Liver also exhibited an early HIF-α response. Carotid blood flow was increased early (Hb ∼70, g/l), but renal blood flow remained relatively constant, only increased at Hb of 50 g/l. Anemia increased nNOS (brain and kidney) and endothelia NOS (eNOS) (kidney) levels. Whereas anemia-induced increases in brain HIFα were nNOS-dependent, our current data demonstrate that increased renal HIFα was nNOS independent. HIF-dependent RNA levels increased linearly (∼10-fold) in the brain. However, renal HIF-RNA responses (MCT4, EPO) increased exponentially (∼100-fold). Plasma EPO levels increased near Hb threshold of 90 g/l, suggesting that the EPO response is sensitive. Collectively, these observations suggest that each organ expresses a different threshold for cellular HIF/NOS hypoxia responses. This knowledge may help define the mechanism(s) by which the brain and kidney maintain oxygen homeostasis during anemia. Copyright © 2014 the American Physiological Society.

  7. iNOS-derived nitric oxide promotes glycolysis by inducing pyruvate kinase M2 nuclear translocation in ovarian cancer.

    PubMed

    Li, Linlin; Zhu, Lingqun; Hao, Bingtao; Gao, Wenwen; Wang, Qianli; Li, Keyi; Wang, Meng; Huang, Mengqiu; Liu, Zhengjun; Yang, Qiaohong; Li, Xiqing; Zhong, Zhuo; Huang, Wenhua; Xiao, Guanghui; Xu, Yang; Yao, Kaitai; Liu, Qiuzhen

    2017-05-16

    Aerobic glycolysis is essential for tumor growth and survival. Activation of multiple carcinogenic signals contributes to metabolism reprogramming during malignant transformation of cancer. Recently nitric oxide has been noted to promote glycolysis but the mechanism remains elusive. We report here the dual role of nitric oxide in glycolysis: low/physiological nitric oxide (≤ 100 nM) promotes glycolysis for ATP production, oxidative defense and cell proliferation of ovary cancer cells, whereas excess nitric oxide (≥ 500 nM) inhibits it. Nitric oxide has a positive effect on glycolysis by inducing PKM2 nuclear translocation in an EGFR/ERK2 signaling-dependent manner. Moreover, iNOS induced by mild inflammatory stimulation increased glycolysis and cell proliferation by producing low doses of nitric oxide, while hyper inflammation induced iNOS inhibited it by producing excess nitric oxide. Finally, iNOS expression is abnormally increased in ovarian cancer tissues and is correlated with PKM2 expression. Overexpression of iNOS is associated with aggressive phenotype and poor survival outcome in ovarian cancer patients. Our study indicated that iNOS/NO play a dual role of in tumor glycolysis and progression, and established a bridge between iNOS/NO signaling pathway and EGFR/ERK2/PKM2 signaling pathway, suggesting that interfering glycolysis by targeting the iNOS/NO/PKM2 axis may be a valuable new therapeutic approach of treating ovarian cancer.

  8. iNOS-derived nitric oxide promotes glycolysis by inducing pyruvate kinase M2 nuclear translocation in ovarian cancer

    PubMed Central

    Hao, Bingtao; Gao, Wenwen; Wang, Qianli; Li, Keyi; Wang, Meng; Huang, Mengqiu; Liu, Zhengjun; Yang, Qiaohong; Li, Xiqing; Zhong, Zhuo; Huang, Wenhua; Xiao, Guanghui; Xu, Yang; Yao, Kaitai; Liu, Qiuzhen

    2017-01-01

    Aerobic glycolysis is essential for tumor growth and survival. Activation of multiple carcinogenic signals contributes to metabolism reprogramming during malignant transformation of cancer. Recently nitric oxide has been noted to promote glycolysis but the mechanism remains elusive. We report here the dual role of nitric oxide in glycolysis: low/physiological nitric oxide (≤ 100 nM) promotes glycolysis for ATP production, oxidative defense and cell proliferation of ovary cancer cells, whereas excess nitric oxide (≥ 500 nM) inhibits it. Nitric oxide has a positive effect on glycolysis by inducing PKM2 nuclear translocation in an EGFR/ERK2 signaling-dependent manner. Moreover, iNOS induced by mild inflammatory stimulation increased glycolysis and cell proliferation by producing low doses of nitric oxide, while hyper inflammation induced iNOS inhibited it by producing excess nitric oxide. Finally, iNOS expression is abnormally increased in ovarian cancer tissues and is correlated with PKM2 expression. Overexpression of iNOS is associated with aggressive phenotype and poor survival outcome in ovarian cancer patients. Our study indicated that iNOS/NO play a dual role of in tumor glycolysis and progression, and established a bridge between iNOS/NO signaling pathway and EGFR/ERK2/PKM2 signaling pathway, suggesting that interfering glycolysis by targeting the iNOS/NO/PKM2 axis may be a valuable new therapeutic approach of treating ovarian cancer. PMID:28380434

  9. Gallic Acid Enriched Fraction of Phyllanthus emblica Potentiates Indomethacin-Induced Gastric Ulcer Healing via e-NOS-Dependent Pathway

    PubMed Central

    Chatterjee, Ananya; Chatterjee, Sirshendu; Biswas, Angshuman; Bhattacharya, Sayanti; Chattopadhyay, Subrata; Bandyopadhyay, Sandip K.

    2012-01-01

    The healing activity of gallic acid enriched ethanolic extract (GAE) of Phyllanthus emblica fruits (amla) against the indomethacin-induced gastric ulceration in mice was investigated. The activity was correlated with the ability of GAE to alter the cyclooxygenase- (COX-) dependent healing pathways. Histology of the stomach tissues revealed maximum ulceration on the 3rd day after indomethacin (18 mg/kg, single dose) administration that was associated with significant increase in inflammatory factors, namely, mucosal myeloperoxidase (MPO) activity and inducible nitric oxide synthase (i-NOS) expression. Proangiogenic parameters such as the levels of prostaglandin (PG) E2, vascular endothelial growth factor (VEGF), hepatocyte growth factor (HGF), von Willebrand Factor VIII, and endothelial NOS (e-NOS) were downregulated by indomethacin. Treatment with GAE (5 mg/kg/day) and omeprazole (3 mg/kg/day) for 3 days led to effective healing of the acute ulceration, while GAE could reverse the indomethacin-induced proinflammatory changes of the designated biochemical parameters. The ulcer healing activity of GAE was, however, compromised by coadministration of the nonspecific NOS inhibitor, N-nitro-L-arginine methyl ester (L-NAME), but not the i-NOS-specific inhibitor, L-N6-(1-iminoethyl) lysine hydrochloride (L-NIL). Taken together, these results suggested that the GAE treatment accelerates ulcer healing by inducing PGE2 synthesis and augmenting e-NOS/i-NOS ratio. PMID:22966242

  10. NF-kappaB mediates mitogen-activated protein kinase pathway-dependent iNOS expression in human melanoma.

    PubMed

    Uffort, Deon G; Grimm, Elizabeth A; Ellerhorst, Julie A

    2009-01-01

    Tumor expression of inducible nitric oxide synthase (iNOS) predicts poor outcomes for melanoma patients. We have reported the regulation of melanoma iNOS by the mitogen-activated protein kinase (MAPK) pathway. In this study, we test the hypothesis that NF-kappaB mediates this regulation. Western blotting of melanoma cell lysates confirmed the constitutive expression of iNOS. Western blot detected baseline levels of activated nuclear extracellular signal-regulated kinase and NF-kappaB. Indirect immunofluorescence confirmed the presence of NF-kappaB p50 and p65 in melanoma cell nuclei, with p50 being more prevalent. Electrophoretic mobility shift assay demonstrated baseline NF-kappaB activity, the findings confirmed by supershift analysis. Treatment of melanoma cells with the MEK inhibitor U0126 decreased NF-kappaB binding to its DNA recognition sequence, implicating the MAPK pathway in NF-kappaB activation. Two specific NF-kappaB inhibitors suppressed iNOS expression, demonstrating regulation of iNOS by NF-kappaB. Several experiments indicated the presence of p50 homodimers, which lack a transactivation domain and rely on the transcriptional coactivator Bcl-3 to carry out this function. Bcl-3 was detected in melanoma cells and co-immunoprecipitated with p50. These data suggest that the constitutively activated melanoma MAPK pathway stimulates activation of NF-kappaB hetero- and homodimers, which, in turn, drive iNOS expression and support melanoma tumorigenesis.

  11. Learning as Conceptual Change: Factors Mediating the Development of Preservice Elementary Teachers' Views of Nature of Science

    ERIC Educational Resources Information Center

    Abd-El-Khalick, Fouad; Akerson, Valarie L.

    2004-01-01

    This study assessed, and identified factors in participants' learning ecologies that mediated, the effectiveness of an explicit reflective instructional approach that satisfied conditions for learning as conceptual change on preservice elementary teachers' views of nature of science (NOS). Participants were 28 undergraduate students enrolled in an…

  12. Nature of science in instruction materials of science through the model of educational reconstruction

    NASA Astrophysics Data System (ADS)

    Azizah, Nur; Mudzakir, Ahmad

    2016-02-01

    The study was carried out to reconstruct the science teaching materials charged view of the nature of science (VNOS). This reconstruction process using the Model of Educational Reconstruction (MER), which is the framework for research and development of science education as well as a guide for planning the teaching of science in the schools is limited in two stages, namely: content structure analysis, and empirical studies of learners. The purpose of this study is to obtain a pre-conception of learners and prospective scientists to the topic of the nature of the material and utilization. The method used to descriptive with the instruments is guidelines for interviews for 15 students of class VIII, text analysis sheet, sheet analysis of the concept, and the validation sheet indicators and learning objectives NOS charged on cognitive and affective aspects. The results obtained in the form of pre-conceptions of learners who demonstrate almost 100% of students know the types of materials and some of its nature, the results of the scientist's perspective on the topic of the nature of the material and its use, as well as the results of the validation indicators and learning objectives charged NOS and competencies PISA 2015 cognitive and affective aspects with CVI value of 0.99 and 1.0 after being validated by five experts. This suggests that the indicators and the resulting learning objectives feasible and can proceed to the reconstruction of teaching materials on the topic of material properties and utilization.

  13. Nitric oxide synthase 2 (NOS2) expression in histologically normal margins of oral squamous cell carcinoma.

    PubMed

    Morelatto, Rosana; Itoiz, María-Elina; Guiñazú, Natalia; Piccini, Daniel; Gea, Susana; López-de Blanc, Silvia

    2014-05-01

    The activity of Nitric Oxide Synthase 2 (NOS2) was found in oral squamous cell carcinomas (OSCC) but not in normal mucosa. Molecular changes associated to early carcinogenesis have been found in mucosa near carcinomas, which is considered a model to study field cancerization. The aim of the present study is to analyze NOS2 expression at the histologically normal margins of OSCC. Eleven biopsy specimens of OSCC containing histologically normal margins (HNM) were analyzed. Ten biopsies of normal oral mucosa were used as controls. The activity of NOS2 was determined by immunohistochemistry. Salivary nitrate and nitrite as well as tobacco and alcohol consumption were also analyzed. The Chi-squared test was applied. Six out of the eleven HNM from carcinoma samples showed positive NOS2 activity whereas all the control group samples yielded negative (p=0.005). No statistically significant association between enzyme expression and tobacco and/or alcohol consumption and salivary nitrate and nitrite was found. NOS2 expression would be an additional evidence of alterations that may occur in a state of field cancerization before the appearance of potentially malignant morphological changes.

  14. Endothelial NOS-dependent activation of c-Jun NH(2)- terminal kinase by oxidized low-density lipoprotein

    NASA Technical Reports Server (NTRS)

    Go, Y. M.; Levonen, A. L.; Moellering, D.; Ramachandran, A.; Patel, R. P.; Jo, H.; Darley-Usmar, V. M.

    2001-01-01

    Oxidized low-density lipoprotein (oxLDL) is known to activate a number of signal transduction pathways in endothelial cells. Among these are the c-Jun NH(2)-terminal kinase (JNK), also known as stress-activated protein kinase, and extracellular signal-regulated kinase (ERK). These mitogen-activated protein kinases (MAP kinase) determine cell survival in response to environmental stress. Interestingly, JNK signaling involves redox-sensitive mechanisms and is activated by reactive oxygen and nitrogen species derived from both NADPH oxidases, nitric oxide synthases (NOS), peroxides, and oxidized low-density lipoprotein (oxLDL). The role of endothelial NOS (eNOS) in the activation of JNK in response to oxLDL has not been examined. Herein, we show that on exposure of endothelial cells to oxLDL, both ERK and JNK are activated through independent signal transduction pathways. A key role of eNOS activation through a phosphatidylinositol-3-kinase-dependent mechanism leading to phosphorylation of eNOS is demonstrated for oxLDL-dependent activation of JNK. Moreover, we show that activation of ERK by oxLDL is critical in protection against the cytotoxicity of oxLDL.

  15. Cardiovascular responses and neurotransmitter changes during static muscle contraction following blockade of inducible nitric oxide synthase (iNOS) within the ventrolateral medulla.

    PubMed

    Ally, Ahmmed; Phattanarudee, Siripan; Kabadi, Shruti; Patel, Maitreyee; Maher, Timothy J

    2006-05-23

    The enzyme nitric oxide synthase (NOS) which is necessary for the production of nitric oxide from L-arginine exists in three isoforms: neuronal NOS (nNOS), endothelial NOS (eNOS), and inducible NOS (iNOS). Our previous studies have demonstrated the roles of nNOS and eNOS within the rostral (RVLM) and caudal ventrolateral medulla (CVLM) in modulating cardiovascular responses during static skeletal muscle contraction via altering localized glutamate and GABA levels (Brain Res. 977 (2003) 80-89; Neuroscience Res. 52 (2005) 21-30). In this study, we investigated the role of iNOS within the RVLM and CVLM on cardiovascular responses and glutamatergic/GABAergic neurotransmission during the exercise pressor reflex. Bilateral microdialysis of a selective iNOS antagonist, aminoguanidine (AGN; 1.0 microM), for 60 min into the RVLM attenuated increases in mean arterial pressure (MAP), heart rate (HR), and extracellular glutamate levels during a static muscle contraction. Levels of GABA within the RVLM were increased. After 120 min of discontinuation of the drug, MAP and HR responses and glutamate/GABA concentrations recovered to baseline values during a subsequent muscle contraction. In contrast, bilateral application of AGN (1.0 microM) into CVLM potentiated cardiovascular responses and glutamate concentration while attenuating levels of GABA during a static muscle contraction. All values recovered after 120 min of discontinuation of the drug. These results demonstrate that iNOS within the ventrolateral medulla plays an important role in modulating cardiovascular responses and glutamatergic/GABAergic neurotransmission that regulates the exercise pressor reflex.

  16. Rosmanol potently inhibits lipopolysaccharide-induced iNOS and COX-2 expression through downregulating MAPK, NF-kappaB, STAT3 and C/EBP signaling pathways.

    PubMed

    Lai, Ching-Shu; Lee, Jong Hun; Ho, Chi-Tang; Liu, Cheng Bin; Wang, Ju-Ming; Wang, Ying-Jan; Pan, Min-Hsiung

    2009-11-25

    Rosmanol is a natural polyphenol from the herb rosemary (Rosmarinus officinalis L.) with high antioxidant activity. In this study, we investigated the inhibitory effects of rosmanol on the induction of NO synthase (NOS) and COX-2 in RAW 264.7 cells induced by lipopolysaccharide (LPS). Rosmanol markedly inhibited LPS-stimulated iNOS and COX-2 protein and gene expression, as well as the downstream products, NO and PGE2. Treatment with rosmanol also reduced translocation of the nuclear factor-kappaB (NF-kappaB) subunits by prevention of the degradation and phosphorylation of inhibitor kappaB (IkappaB). Western blot analysis showed that rosmanol significantly inhibited translocation and phosphorylation of NF-kappaB, signal transducer and activator of transcription-3 (STAT3), and the protein expression of C/EBPbeta and C/EBPdelta. We also found that rosmanol suppressed LPS-induced phosphorylation of ERK1/2, p38 mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3-kinase (PI3K)/Akt signaling. Our results demonstrate that rosmanol downregulates inflammatory iNOS and COX-2 gene expression by inhibiting the activation of NF-kappaB and STAT3 through interfering with the activation of PI3K/Akt and MAPK signaling. Taken together, rosmanol might contribute to the potent anti-inflammatory effect of rosemary and may have potential to be developed into an effective anti-inflammatory agent.

  17. Religious Belief: The Main Impact on the Perception of the Nature of Science on Student Teachers

    ERIC Educational Resources Information Center

    Aflalo, Ester

    2013-01-01

    This study aims to examine the affect of the degree of religiosity of student teachers, and their nationalism and scientific background on their perception of the nature of science (NOS). First year Arab and Jewish religiously observant, traditional and secular students in Israel (101 in number) with different scientific backgrounds participated…

  18. Communicating the Nature of Science through "The Big Bang Theory": Evidence from a Focus Group Study

    ERIC Educational Resources Information Center

    Li, Rashel; Orthia, Lindy A.

    2016-01-01

    In this paper, we discuss a little-studied means of communicating about or teaching the nature of science (NOS)--through fiction television. We report some results of focus group research which suggest that the American sitcom "The Big Bang Theory" (2007-present), whose main characters are mostly working scientists, has influenced…

  19. The Effect of Explicit Embedded Reflective Instruction on Nature of Science Understandings in Advanced Science Students

    ERIC Educational Resources Information Center

    Koksal, Mustafa Serdar; Cakiroglu, Jale; Geban, Omer

    2013-01-01

    The purpose of this study is to investigate the effectiveness of explicit-embedded-reflective (EER) instruction in nature of science (NOS) understandings of ninth-grade advanced science students. This study was conducted with 71 students, who were divided into three groups, by using non-equivalent quasi-experimental design. In the treatment…

  20. Gender, exercise training, and eNOS expression in porcine skeletal muscle arteries.

    PubMed

    Laughlin, M Harold; Welshons, Wade V; Sturek, Michael; Rush, James W E; Turk, James R; Taylor, Julia A; Judy, Barbara M; Henderson, Kyle K; Ganjam, V K

    2003-07-01

    Our purpose was to determine the effects of gender and exercise training on endothelial nitric oxide synthase (eNOS) and superoxide dismutase (SOD) protein content of porcine skeletal muscle arteries and to evaluate the role of 17beta-estradiol (E2) in these effects. We measured eNOS and SOD content with immunoblots and immunohistochemistry in femoral and brachial arteries of trained and sedentary male and female pigs and measured estrogen receptor (ER) mRNA and alpha-ER and beta-ER protein in aortas of male and female pigs. Results indicate that female arteries contain more eNOS than male arteries and that exercise training increases eNOS content independent of gender. Male and female pigs expressed similar levels of alpha-ER mRNA and protein and similar amounts beta-ER protein in their arteries. E2 concentrations as measured by RIA were 180 +/- 34 pg/ml in male sera and approximately 5 pg/ml in female sera, and neither was changed by training. However, bioassay indicated that biologically active estrogen equivalent to only 35 +/- 5 pg/ml was present in male sera. E2 in female pigs, whether measured by RIA or bioassay, was approximately 24 pg/ml at peak estrous and 2 pg/ml on day 5 diestrus. The free fraction of E2 in sera did not explain the low measurements, relative to RIA, of E2. We conclude that 1). gender has significant influence on eNOS and SOD content of porcine skeletal muscle arteries; 2). the effects of gender and exercise training vary among arteries of different anatomic origin; 3). male sera contains compounds that cause RIA to overestimate circulating estrogenic activity; and 4). relative to human men, the male pig is not biologically estrogenized by high levels of E2 reported by RIA, whereas in female pigs E2 levels are lower than in the blood of human women.

  1. Characterization of Short Range DNA Looping in Endotoxin-mediated Transcription of the Murine Inducible Nitric-oxide Synthase (iNOS) Gene*

    PubMed Central

    Guo, Hongtao; Mi, Zhiyong; Kuo, Paul C.

    2008-01-01

    The local structural properties and spatial conformations of chromosomes are intimately associated with gene expression. The spatial associations of critical genomic elements in inducible nitric-oxide synthase (iNOS) transcription have not been previously examined. In this regard, the murine iNOS promoter contains 2 NF-κB binding sites (nt –86 and nt –972) that are essential for maximal transactivation of iNOS by LPS. Although AP-1 is commonly listed as an essential transcription factor for LPS-mediated iNOS transactivation, the relationship between AP-1 and NF-κB in this setting is not well studied. In this study using a model of LPS-stimulated ANA-1 murine macrophages, we demonstrate that short range DNA looping occurs at the iNOS promoter. This looping requires the presence of AP-1, c-Jun, NF-κB p65, and p300-associated acetyltransferase activity. The distal AP-1 binding site interacts via p300 with the proximal NF-κB binding site to create this DNA loop to participate in iNOS transcription. Other geographically distant AP-1 and NF-κB sites are certainly occupied, but selected sites are critical for iNOS transcription and the formation of the c-Jun, p65, and p300 transcriptional complex. In this “simplified” model of murine iNOS promoter, numerous transcription factors recognize and bind to various response elements, but these locales do not equally contribute to iNOS gene transcription. PMID:18596035

  2. Las Rocas Nos Cuentan (Rocks Tell Their Stories)

    ERIC Educational Resources Information Center

    Llerandi-Roman, Pablo A.

    2012-01-01

    Many Earth science lessons today still focus on memorizing the names of rocks and minerals. This led the author to develop a lesson that reveals the fascinating stories told by rocks through the study of their physical properties. He first designed the lesson for Puerto Rican teachers, hence its Spanish title: "Las Rocas Nos Cuentan Su Historia."…

  3. IL-10 and NOS2 Modulate Antigen-Specific Reactivity and Nerve Infiltration by T Cells in Experimental Leprosy

    PubMed Central

    Hagge, Deanna A.; Scollard, David M.; Ray, Nashone A.; Marks, Vilma T.; Deming, Angelina T.; Spencer, John S.; Adams, Linda B.

    2014-01-01

    Background Although immunopathology dictates clinical outcome in leprosy, the dynamics of early and chronic infection are poorly defined. In the tuberculoid region of the spectrum, Mycobacterium leprae growth is restricted yet a severe granulomatous lesion can occur. The evolution and maintenance of chronic inflammatory processes like those observed in the leprosy granuloma involve an ongoing network of communications via cytokines. IL-10 has immunosuppressive properties and IL-10 genetic variants have been associated with leprosy development and reactions. Methodology/Principal Findings The role of IL-10 in resistance and inflammation in leprosy was investigated using Mycobacterium leprae infection of mice deficient in IL-10 (IL-10−/−), as well as mice deficient in both inducible nitric oxide synthase (NOS2−/−) and IL-10 (10NOS2−/−). Although a lack of IL-10 did not affect M. leprae multiplication in the footpads (FP), inflammation increased from C57Bl/6 (B6)NOS2−/−<10NOS2−/−. While IL-10−/− mice exhibited modest FP induration compared to B6, NOS2−/− and 10NOS2−/− mice developed markedly enlarged FP marking distinct phases: early (1 month), peak (3–4 months), and chronic (8 months). IFN-γ-producing CD4+CD44+ cells responding to M. leprae cell wall, membrane, and cytosol antigens and ML2028 (Ag85B) were significantly increased in the evolved granuloma in NOS2−/− FP compared to B6 and IL-10−/− during early and peak phases. In 10NOS2−/− FP, CD4+CD44+ and especially CD8+CD44+ responses were augmented even further to these antigens as well as to ML0380 (GroES), ML2038 (bacterioferritin), and ML1877 (EF-Tu). Moreover, fragmented nerves containing CD4+ cells were present in 10NOS2−/− FP. Conclusions/Significance The 10NOS2−/− strain offers insight on the regulation of granuloma formation and maintenance by immune modulators in the resistant forms of leprosy and presents a new model for investigating the

  4. 36. ISLAND PLANT: Nos. 1 AND 2 TWENTYSIX INCH HORIZONTAL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    36. ISLAND PLANT: Nos. 1 AND 2 TWENTY-SIX INCH HORIZONTAL SAMSON TURBINES - American Falls Water, Power & Light Company, Island Power Plant, Snake River, below American Falls Dam, American Falls, Power County, ID

  5. Antioxidative effects of cinnamomi cortex: A potential role of iNOS and COX-II

    PubMed Central

    Chung, Jin-Won; Kim, Jeong-Jun; Kim, Sung-Jin

    2011-01-01

    Background: Cinnamomi cortex has wide varieties of pharmacological actions such as anti-inflammatory action, anti-platelet aggregation, and improving blood circulation. In this study, we tested to determine whether the Cinnamomi cortex extract has antioxidant activities. Materials and Methods: Antioxidative actions were explored by measuring free radical scavenging activity, NO levels, and reducing power. The mechanism of antioxidative action of Cinnamomi cortex was determined by measuring iNOS and COX-II expression in lipopolysaccharide (LPS) stimulated Raw cells. Results: Seventy percent methanolic extract of Cinnamomi cortex exerted significant 1,1-diphenyl--2--picrylhydrazyl (DPPH) free radicals and NO scavenging activities in a dose-dependent manner. More strikingly, the Cinnamomi cortex extract exerted dramatic reducing power activity (13-fold over control). Production of iNOS induced by LPS was significantly inhibited by the Cinnamomi cortex extract, suggesting that it inhibits NO production by suppressing iNOS expression. Additionally, COX-2 induced by LPS was dramatically inhibited by the Cinnamomi cortex extract. Conclusion: These results suggest that 70% methanolic extract of Cinnamomi cortex exerts significant antioxidant activity via inhibiting iNOS and COX-II induction. PMID:22262934

  6. Relationships between Scientific Process Skills and Scientific Creativity: Mediating Role of Nature of Science Knowledge

    ERIC Educational Resources Information Center

    Ozdemir, Gokhan; Dikici, Ayhan

    2017-01-01

    The purpose of this study is to explore the strength of relationships between 7th grade students' Scientific Process Skills (SPS), Nature of Science (NOS) beliefs, and Scientific Creativity (SC) through Structural Equation Modeling (SEM). For this purpose, data were collected from 332 students of two public middle school students in Turkey. SPS,…

  7. iNOS-Derived Nitric Oxide Stimulates Osteoclast Activity and Alveolar Bone Loss in Ligature-Induced Periodontitis in Rats

    PubMed Central

    Herrera, Bruno S.; Martins-Porto, Rodrigo; Maia-Dantas, Aline; Campi, Paula; Spolidorio, Luis C.; Costa, Soraia K.P.; Van Dyke, Thomas E.; Gyurko, Robert; Muscara, Marcelo N.

    2012-01-01

    Background Inflammatory stimuli activate inducible nitric oxide synthase (iNOS) in a variety of cell types, including osteoclasts (OC) and osteoblasts, resulting in sustained NO production. In this study, we evaluate the alveolar bone loss in rats with periodontitis under long-term iNOS inhibition, and the differentiation and activity of OC from iNOS-knockout (KO) mice in vitro. Methods Oral aminoguanidine (an iNOS inhibitor) or water treatment was started 2 weeks before induction of periodontitis. Rats were sacrificed 3, 7, or 14 days after ligature placement, and alveolar bone loss was evaluated. In vitro OC culture experiments were also performed to study the differentiation of freshly isolated bone marrow cells from both iNOS KO and wild-type C57BL/6 mice. OC were counted 6 days later after tartrate-resistant acid phosphatase staining (a marker of osteoclast identity), and bone resorption activity was assessed by counting the number of resorption pits on dentin disks. Results Rats with ligature showed progressive and significant alveolar bone loss compared to sham animals, and aminoguanidine treatment significantly inhibited ligature-induced bone loss at 7 and 14 days after the induction. In comparison to bone marrow cells from wild-type mice, cells from iNOS KO mice showed decreased OC growth and the resulting OC covered a smaller culture dish area and generated fewer resorption pit counts. Conclusion Our results demonstrate that iNOS inhibition prevents alveolar bone loss in a rat model of ligature-induced periodontitis, thus confirming that iNOS-derived NO plays a crucial role in the pathogenesis of periodontitis, probably by stimulating OC differentiation and activity. PMID:21417589

  8. Synthesis of a Potent Aminopyridine-Based nNOS-Inhibitor by Two Recent No-Carrier-Added (18)F-Labelling Methods.

    PubMed

    Drerup, Christian; Ermert, Johannes; Coenen, Heinz H

    2016-09-01

    Nitric oxide (NO), an important multifunctional signaling molecule, is produced by three isoforms of NO-synthase (NOS) and has been associated with neurodegenerative disorders. Selective inhibitors of the subtypes iNOS (inducible) or nNOS (neuronal) are of great interest for decoding neurodestructive key factors, and (18)F-labelled analogues would allow investigating the NOS-function by molecular imaging with positron emission tomography. Especially, the highly selective nNOS inhibitor 6-((3-((3-fluorophenethylamino)methyl)phenoxy)methyl)-4-methylpyridin-2-amine (10) lends itself as suitable compound to be (18)F-labelled in no-carrier-added (n.c.a.) form. For preparation of the (18)F-labelled nNOS-Inhibitor [(18)F]10 a "build-up" radiosynthesis was developed based on a corresponding iodonium ylide as labelling precursor. The such activated phenethyl group of the compound was efficiently and regioselectively labelled with n.c.a. [(18)F]fluoride in 79% radiochemical yield (RCY). After conversion by reductive amination and microwave assisted displacement of the protecting groups, the desired nNOS-inhibitor was obtained in about 15% total RCY. Alternatively, for a simplified "late-stage" (18)F-labelling procedure a corresponding boronic ester precursor was synthesized and successfully used in a newer, copper(II) mediated n.c.a. (18)F-fluoro-deboroniation reaction, achieving the same total RCY. Thus, both methods proved comparatively suited to provide the highly selective NOS-inhibitor [(18)F]10 as probe for preclinical in vivo studies.

  9. Assessing depression outcome in patients with moderate dementia: sensitivity of the HoNOS65+ scale.

    PubMed

    Canuto, Alessandra; Rudhard-Thomazic, Valérie; Herrmann, François R; Delaloye, Christophe; Giannakopoulos, Panteleimon; Weber, Kerstin

    2009-08-15

    To date, there is no widely accepted clinical scale to monitor the evolution of depressive symptoms in demented patients. We assessed the sensitivity to treatment of a validated French version of the Health of the Nation Outcome Scale (HoNOS) 65+ compared to five routinely used scales. Thirty elderly inpatients with ICD-10 diagnosis of dementia and depression were evaluated at admission and discharge using paired t-test. Using the Brief Psychiatric Rating Scale (BPRS) "depressive mood" item as gold standard, a receiver operating characteristic curve (ROC) analysis assessed the validity of HoNOS65+F "depressive symptoms" item score changes. Unlike Geriatric Depression Scale, Mini Mental State Examination and Activities of Daily Living scores, BPRS scores decreased and Global Assessment Functioning Scale score increased significantly from admission to discharge. Amongst HoNOS65+F items, "behavioural disturbance", "depressive symptoms", "activities of daily life" and "drug management" items showed highly significant changes between the first and last day of hospitalization. The ROC analysis revealed that changes in the HoNOS65+F "depressive symptoms" item correctly classified 93% of the cases with good sensitivity (0.95) and specificity (0.88) values. These data suggest that the HoNOS65+F "depressive symptoms" item may provide a valid assessment of the evolution of depressive symptoms in demented patients.

  10. (−)-Epicatechin induces calcium and translocation independent eNOS activation in arterial endothelial cells

    PubMed Central

    Ramirez-Sanchez, Israel; Maya, Lisandro; Ceballos, Guillermo

    2011-01-01

    The consumption of cacao-derived (i.e., cocoa) products provides beneficial cardiovascular effects in healthy subjects as well as individuals with endothelial dysfunction such as smokers, diabetics, and postmenopausal women. The vascular actions of cocoa are related to enhanced nitric oxide (NO) production. These actions can be reproduced by the administration of the cacao flavanol (−)-epicatechin (EPI). To further understand the mechanisms behind the vascular action of EPI, we investigated the effects of Ca2+ depletion on endothelial nitric oxide (NO) synthase (eNOS) activation/phosphorylation and translocation. Human coronary artery endothelial cells were treated with EPI or with bradykinin (BK), a well-known Ca2+-dependent eNOS activator. Results demonstrate that both EPI and BK induce increases in intracellular calcium and NO levels. However, under Ca2+-free conditions, EPI (but not BK) is still capable of inducing NO production through eNOS phosphorylation at serine 615, 633, and 1177. Interestingly, EPI-induced translocation of eNOS from the plasmalemma was abolished upon Ca2+ depletion. Thus, under Ca2+-free conditions, EPI can stimulate NO synthesis independent of calmodulin binding to eNOS and of its translocation into the cytoplasm. We also examined the effect of EPI on the NO/cGMP/vasodilator-stimulated phosphoprotein (VASP) pathway activation in isolated Ca2+-deprived canine mesenteric arteries. Results demonstrate that under these conditions, EPI induces the activation of this vasorelaxation-related pathway and that this effect is inhibited by pretreatment with nitro-l-arginine methyl ester, suggesting a functional relevance for this phenomenon. PMID:21209365

  11. Substrate-Tuned Catalysis of the Radical S-Adenosyl-L-Methionine Enzyme NosL Involved in Nosiheptide Biosynthesis.

    PubMed

    Ji, Xinjian; Li, Yongzhen; Ding, Wei; Zhang, Qi

    2015-07-27

    NosL is a radical S-adenosyl-L-methionine (SAM) enzyme that converts L-Trp to 3-methyl-2-indolic acid, a key intermediate in the biosynthesis of a thiopeptide antibiotic nosiheptide. In this work we investigated NosL catalysis by using a series of Trp analogues as the molecular probes. Using a benzofuran substrate 2-amino-3-(benzofuran-3-yl)propanoic acid (ABPA), we clearly demonstrated that the 5'-deoxyadenosyl (dAdo) radical-mediated hydrogen abstraction in NosL catalysis is not from the indole nitrogen but likely from the amino group of L-Trp. Unexpectedly, the major product of ABPA is a decarboxylated compound, indicating that NosL was transformed to a novel decarboxylase by an unnatural substrate. Furthermore, we showed that, for the first time to our knowledge, the dAdo radical-mediated hydrogen abstraction can occur from an alcohol hydroxy group. Our study demonstrates the intriguing promiscuity of NosL catalysis and highlights the potential of engineering radical SAM enzymes for novel activities. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. 5. POWERHOUSE, PELTONFRANCIS TURBINES (GENERATORS) UNITS NOS. 1 AND 2 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. POWERHOUSE, PELTON-FRANCIS TURBINES (GENERATORS) UNITS NOS. 1 AND 2 WITH REGULATOR PANEL AT LEFT AND GATE VALVE IN CENTER FOREGROUND - Yosemite Hydroelectric Power Plant, Highways 120 & 140, Yosemite Village, Mariposa County, CA

  13. The calcium channel blocker amlodipine promotes the unclamping of eNOS from caveolin in endothelial cells.

    PubMed

    Batova, Suzan; DeWever, Julie; Godfraind, Théophile; Balligand, Jean-Luc; Dessy, Chantal; Feron, Olivier

    2006-08-01

    Amlodipine is a calcium channel blocker (CCB) known to stimulate nitric oxide production from endothelial cells. Whether this ancillary property can be related to the capacity of amlodipine to concentrate and alter the structure of cholesterol-containing membrane bilayers is a matter of investigation. Here, we reasoned that since the endothelial nitric oxide synthase is, in part, expressed in cholesterol-rich plasmalemmal microdomains (e.g., caveolae and rafts), amlodipine could interfere with this specific locale of the enzyme and thereby modulate NO production in endothelial cells. Using a method combining lubrol-based extraction and subcellular fractionation on sucrose gradient, we found that amlodipine, but not verapamil or nifedipine, induced the segregation of endothelial NO synthase (eNOS) from caveolin-enriched low-density membranes (8+/-2% vs. 42+/-3% in untreated condition; P<0.01). We then performed co-immunoprecipitation experiments and found that amlodipine dose-dependently disrupted the caveolin/eNOS interaction contrary to other calcium channel blockers, and potentiated the stimulation of NO production by agonists such as bradykinin and vascular endothelial growth factor (VEGF) (+138+/-28% and +183+/-27% over values obtained with the agonist alone, respectively; P<0.01). Interestingly, we also documented that the dissociation of the caveolin/eNOS heterocomplex induced by amlodipine was not mediated by the traditional calcium-dependent calmodulin binding to eNOS and that recombinant caveolin expression could compete with the stimulatory effects of amlodipine on eNOS activity. Finally, we showed that the amlodipine-triggered, caveolin-dependent mechanism of eNOS activation was independent of other pleiotropic effects of the CCB such as superoxide anion scavenging and angiotensin-converting enzyme (ACE) inhibition. This study unravels the modulatory effects of amlodipine on caveolar integrity and the capacity of caveolin to maintain eNOS in its vicinity

  14. 76 FR 4391 - Calvert Cliffs Nuclear Power Plant, LLC, Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and 2...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-25

    ... Nuclear Power Plant, LLC, Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and 2; Exemption 1.0 Background Calvert Cliffs Nuclear Power Plant, LLC, the licensee, is the holder of Facility Operating License Nos. DPR-53 and DPR-69 which authorizes operation of the Calvert Cliffs Nuclear Power Plant, Unit Nos. 1...

  15. β-Adrenergic induced SR Ca2+ leak is mediated by an Epac-NOS pathway.

    PubMed

    Pereira, Laëtitia; Bare, Dan J; Galice, Samuel; Shannon, Thomas R; Bers, Donald M

    2017-07-01

    Cardiac β-adrenergic receptors (β-AR) and Ca 2+ -Calmodulin dependent protein kinase (CaMKII) regulate both physiological and pathophysiological Ca 2+ signaling. Elevated diastolic Ca 2+ leak from the sarcoplasmic reticulum (SR) contributes to contractile dysfunction in heart failure and to arrhythmogenesis. β-AR activation is known to increase SR Ca 2+ leak via CaMKII-dependent phosphorylation of the ryanodine receptor. Two independent and reportedly parallel pathways have been implicated in this β-AR-CaMKII cascade, one involving exchange protein directly activated by cAMP (Epac2) and another involving nitric oxide synthase 1 (NOS1). Here we tested whether Epac and NOS function in a single series pathway to increase β-AR induced and CaMKII-dependent SR Ca 2+ leak. Leak was measured as both Ca 2+ spark frequency and tetracaine-induced shifts in SR Ca 2+ , in mouse and rabbit ventricular myocytes. Direct Epac activation by 8-CPT (8-(4-chlorophenylthio)-2'-O-methyl-cAMP) mimicked β-AR-induced SR Ca 2+ leak, and both were blocked by NOS inhibition. The same was true for myocyte CaMKII activation (assessed via a FRET-based reporter) and ryanodine receptor phosphorylation. Inhibitor and phosphorylation studies also implicated phosphoinositide 3-kinase (PI3K) and protein kinase B (Akt) downstream of Epac and above NOS activation in this pathway. We conclude that these two independently characterized parallel pathways function mainly via a single series arrangement (β-AR-cAMP-Epac-PI3K-Akt-NOS1-CaMKII) to mediate increased SR Ca 2+ leak. Thus, for β-AR activation the cAMP-PKA branch effects inotropy and lusitropy (by effects on Ca 2+ current and SR Ca 2+ -ATPase), this cAMP-Epac-NOS pathway increases pathological diastolic SR Ca 2+ leak. This pathway distinction may allow novel SR Ca 2+ leak therapeutic targeting in treatment of arrhythmias in heart failure that spare the inotropic and lusitropic effects of the PKA branch. Copyright © 2017 Elsevier Ltd. All

  16. Vault Area (original section), east corridor, looking north (Vault Nos. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Vault Area (original section), east corridor, looking north (Vault Nos. 1-9 - Fort McNair, Film Store House, Fort Lesley J. McNair, P Street between Third & Fourth Streets, Southwest, Washington, District of Columbia, DC

  17. Post-translational modifications of eNOS augment nitric oxide availability and facilitates hypoxia adaptation in Ladakhi women.

    PubMed

    Pooja; Ghosh, Dishari; Bhargava, Kalpana; Sethy, Niroj Kumar

    2018-06-09

    The lower inhaled oxygen per volume at high altitude poses an intimidating challenge for humans to survive and reproduce. Indigenous populations of the Himalayas reportedly exhibit higher microcirculatory blood flow accompanied by higher orders of magnitude of nitric oxide (NO) products in lung, plasma and red blood cells as a vascular adaptation strategy for hypobaric hypoxia. The precise mechanism of such observed higher NO metabolites for hypoxia adaptation remains elusive. Studying high altitude native Ladakhi women, we observed significant higher eNOS mRNA and protein in blood/plasma as compared to lowland women. We also observed higher level of plasma l-citrulline and NOx (nitrates and nitrites) with concomitant lower levels of arginase mRNA and protein further suggesting higher eNOS activity and NO bioavailability. Interestingly, middle aged postmenopausal Ladakhi women exhibited significantly higher level of eNOS activity, NOx and cGMP as compared to age matched lowland women. Preferential phosphorylation of eNOS on stimulatory Ser1177 and Ser615 as well as dephosphorylation of inhibitory Thr495 site contributed to higher NO availability in Ladakhi women irrespective of age. We also observed higher levels of eNOS activating humoral factors like bradykinin and estrogen in both young and middle-aged Ladakhi women. These results suggest that an altered phosphorylation status, together with an enhanced expression of eNOS and potential humoral endothelial activators, are involved in enhanced activation of the eNOS-NO-cGMP pathway in Ladakhi women irrespective of age, reinforcing the hypothesis that NO metabolites play a major role in Himalayan pattern of hypoxia adaptation. Copyright © 2018 Elsevier Inc. All rights reserved.

  18. A non-synonymous SNP in the NOS2 associated with septic shock in patients with sepsis in Chinese populations.

    PubMed

    Wang, Zhifu; Feng, Kai; Yue, Maoxing; Lu, Xiaoguang; Zheng, Qihan; Zhang, Hongxing; Zhai, Yun; Li, Peiyao; Yu, Lixia; Cai, Mi; Zhang, Xiumei; Kang, Xin; Shi, Weihai; Xia, Xia; Chen, Xi; Cao, Pengbo; Li, Yuanfeng; Chen, Huipeng; Ling, Yan; Li, Yuxia; He, Fuchu; Zhou, Gangqiao

    2013-03-01

    Sepsis represents a systemic inflammatory response to infection and its sequelae include severe sepsis, septic shock, multiple organ dysfunction syndrome (MODS) and death. Studies in mice and humans indicate that the inducible nitric oxide synthase (iNOS, NOS2) plays an important role in the development of sepsis and its sequelae. It was reported that several single nucleotide polymorphisms (SNPs) within NOS2 could influence the production or activity of NOS2. In this study, we assessed whether SNPs within NOS2 gene were associated with severity of sepsis in Chinese populations. A case-control study was conducted, which included 299 and 280 unrelated patients with sepsis recruited from Liaoning and Jiangsu provinces in China, respectively. Six SNPs within NOS2 were genotyped using Sequenom MassARRAY system. The associations between the SNPs and risk of sepsis complications were estimated by a binary logistic regression model adjusted for confounding factors. Functional assay was performed to assess the biological significance. The GA + AA genotype of a non-synonymous SNP in the exon 16 of NOS2 (rs2297518: G>A) was significantly associated with increased susceptibility to septic shock compared with GG genotype in Liaoning population (OR = 3.29, 95% CI = 1.40-7.72, P = 0.0047). This association was confirmed in the Jiangsu population (OR = 3.49, 95% CI = 1.57-7.79, P = 0.0019). Furthermore, the functional assay performed in the immortalized lymphocyte cell lines indicated that the at-risk GA genotype had a tendency of higher NOS2 activity than the GG genotype (P = 0.32). Our findings suggest that the NOS2 rs2297518 may play a role in mediating the susceptibility to septic shock in patients with sepsis in Chinese populations.

  19. Students' Conceptions of the Nature of Science: Perspectives from Canadian and Korean Middle School Students

    NASA Astrophysics Data System (ADS)

    Park, Hyeran; Nielsen, Wendy; Woodruff, Earl

    2014-05-01

    This study examined and compared students' understanding of nature of science (NOS) with 521 Grade 8 Canadian and Korean students using a mixed methods approach. The concepts of NOS were measured using a survey that had both quantitative and qualitative elements. Descriptive statistics and one-way multivariate analysis of variances examined the quantitative data while a conceptually clustered matrix classified the open-ended responses. The country effect could explain 3-12 % of the variances of subjectivity, empirical testability and diverse methods, but it was not significant for the concepts of tentativeness and socio-cultural embeddedness of science. The open-ended responses showed that students believed scientific theories change due to errors or discoveries. Students regarded empirical evidence as undeniable and objective although they acknowledged experiments depend on theories or scientists' knowledge. The open responses revealed that national situations and curriculum content affected their views. For our future democratic citizens to gain scientific literacy, science curricula should include currently acknowledged NOS concepts and should be situated within societal and cultural perspectives.

  20. [Effects of electroacupuncture on hippocampal nNOS expression in rats of post-traumatic stress disorder model].

    PubMed

    Hou, Liang-Qin; Liu, Song; Xiong, Ke-Ren

    2013-07-01

    To explore the mechanism of electroacupuncture (EA) in the treatment of post-traumatic stress disorder (PTSD). Thirty male Sprague-Dawley rats were randomly divided into a normal group, a model group and an electroacupuncture group. The single prolonged stress (SPS) method was used to set up the PTSD models in latter two groups. After SPS Stimulation, EA group was treated with 2Hz electroacupuncture at Baihui (GV 20) and Zusanli (ST 36) for 30 min, once a day for a week. Reverse transcriptase polymerase chain reaction (RT-PCR) and immuno-histochemistry were used to detect the mRNA and protein expression of nNOS in the hippocampus of rats in the each group. (1) The nNOS mRNA expression in hippocampus in model group was higher than that in normal group (P < 0.05). But the expression in EA group was lower significantly than that in model group (P < 0.05). (2) The nNOS protein expression in hippocampus CA1 and CA3 in model group was higher than that in normal group (P < 0.05). But after electroacupuncture treatment, its expression in EA group was lower significantly than that in model group (P < 0.05). The nNOS protein expression in hippocampal CA2 had no difference among all three groups. The elevated nNOS expression in hippocampus may be involved in the pathological process of PTSD. Electroacupuncture play a down-regulation effects in the hippocampal nNOS expression, which may be one mechanism of electroacupuncture for treatment of PTSD.

  1. Preservice Elementary Teachers' Beliefs about Nature of Science and Constructivist Teaching in the Content-Specific Context

    ERIC Educational Resources Information Center

    Yoon, Hye-Gyoung; Kim, Byoung Sug

    2016-01-01

    The purpose of this study was to explore how Korean preservice elementary teachers' beliefs about nature of science (NOS) and their beliefs about constructivist teaching were structured and related and if any relation was prevalent in the content-specific contexts. As the same format, three versions of questionnaires were developed in three…

  2. Tracking the Footprints of Nature of Science in the Path of Learning How to Teach It

    ERIC Educational Resources Information Center

    Bilican, Kader; Ozdem-Yilmaz, Yasemin; Oztekin, Ceren

    2014-01-01

    The present article aimed at understanding those unvoiced biases pre-service teachers may have that conflicts with their integration of nature of science in their science lessons. Three senior pre-service science teachers' views on NOS with regard to their decision making on critical incidents and their reflections about how they…

  3. Effect of aminoguanidine and albendazole on inducible nitric oxide synthase (iNOS) activity in T. spiralis-infected mice muscles.

    PubMed

    Zeromski, Jan; Boczoń, Krystyna; Wandurska-Nowak, Elzbieta; Mozer-Lisewska, Iwona

    2005-01-01

    The aim of this study was to provide evidence for the expression of iNOS in the cells of inflammatory infiltrates around larvae in skeletal muscles of T. spiralis infected mice. The BALB/c mice (n = 8) divided into subgroups, received either aminoguanidine (AMG)--a specific iNOS inhibitor or albendazole (ALB)--an antiparasitic drug of choice in trichinellosis treatment. Control animals (n = 2 in each subgroup) were either uninfected and treated or uninfected and untreated. Frozen sections of hind leg muscles from mice sacrificed at various time intervals after infection were cut and subjected to immunohistochemistry, using monoclonal anti-iNOS antibody. The ALB-treated mice revealed stronger iNOS staining in the infiltrating cells around larvae than the infected and untreated animals. On the contrary, in the AMG-treated animals, the infiltrating cells did not show any specific iNOS reaction. These data confirm the specificity of iNOS staining in the cellular infiltrates around T. spiralis larvae and shed some light on the role of nitric oxide during ALB treatment in experimental trichinellosis.

  4. A vast amount of various invariant tori in the Nosé-Hoover oscillator.

    PubMed

    Wang, Lei; Yang, Xiao-Song

    2015-12-01

    This letter restudies the Nosé-Hoover oscillator. Some new averagely conservative regions are found, each of which is filled with different sequences of nested tori with various knot types. Especially, the dynamical behaviors near the border of "chaotic region" and conservative regions are studied showing that there exist more complicated and thinner invariant tori around the boundaries of conservative regions bounded by tori. Our results suggest an infinite number of island chains in a "chaotic sea" for the Nosé-Hoover oscillator.

  5. A vast amount of various invariant tori in the Nosé-Hoover oscillator

    NASA Astrophysics Data System (ADS)

    Wang, Lei; Yang, Xiao-Song

    2015-12-01

    This letter restudies the Nosé-Hoover oscillator. Some new averagely conservative regions are found, each of which is filled with different sequences of nested tori with various knot types. Especially, the dynamical behaviors near the border of "chaotic region" and conservative regions are studied showing that there exist more complicated and thinner invariant tori around the boundaries of conservative regions bounded by tori. Our results suggest an infinite number of island chains in a "chaotic sea" for the Nosé-Hoover oscillator.

  6. 10. VIEW OF GENERATING ROOM, POWERHOUSE, SHOWING ORIGINAL GENERATORS NOS. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. VIEW OF GENERATING ROOM, POWERHOUSE, SHOWING ORIGINAL GENERATORS NOS. 1 THROUGH 4, WITH NO. 4 GENERATOR IN FOREGROUND - Nine Mile Hydroelectric Development, Powerhouse, State Highway 291 along Spokane River, Nine Mile Falls, Spokane County, WA

  7. 37. ISLAND PLANT: Nos. 1 AND 2 TWENTYSIX INCH SPECIAL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    37. ISLAND PLANT: Nos. 1 AND 2 TWENTY-SIX INCH SPECIAL HORIZONTAL SAMSON TURBINE (RIVITED CASE) - American Falls Water, Power & Light Company, Island Power Plant, Snake River, below American Falls Dam, American Falls, Power County, ID

  8. miR-708-5p and miR-34c-5p are involved in nNOS regulation in dystrophic context.

    PubMed

    Guilbaud, Marine; Gentil, Christel; Peccate, Cécile; Gargaun, Elena; Holtzmann, Isabelle; Gruszczynski, Carole; Falcone, Sestina; Mamchaoui, Kamel; Ben Yaou, Rabah; Leturcq, France; Jeanson-Leh, Laurence; Piétri-Rouxel, France

    2018-04-27

    Duchenne (DMD) and Becker (BMD) muscular dystrophies are caused by mutations in the DMD gene coding for dystrophin, a protein being part of a large sarcolemmal protein scaffold that includes the neuronal nitric oxide synthase (nNOS). The nNOS was shown to play critical roles in a variety of muscle functions and alterations of its expression and location in dystrophic muscle fiber leads to an increase of the muscle fatigability. We previously revealed a decrease of nNOS expression in BMD patients all presenting a deletion of exons 45 to 55 in the DMD gene (BMDd45-55), impacting the nNOS binding site of dystrophin. Since several studies showed deregulation of microRNAs (miRNAs) in dystrophinopathies, we focused on miRNAs that could target nNOS in dystrophic context. By a screening of 617 miRNAs in BMDd45-55 muscular biopsies using TLDA and an in silico study to determine which one could target nNOS, we selected four miRNAs. In order to select those that targeted a sequence of 3'UTR of NOS1, we performed luciferase gene reporter assay in HEK393T cells. Finally, expression of candidate miRNAs was modulated in control and DMD human myoblasts (DMDd45-52) to study their ability to target nNOS. TLDA assay and the in silico study allowed us to select four miRNAs overexpressed in muscle biopsies of BMDd45-55 compared to controls. Among them, only the overexpression of miR-31, miR-708, and miR-34c led to a decrease of luciferase activity in an NOS1-3'UTR-luciferase assay, confirming their interaction with the NOS1-3'UTR. The effect of these three miRNAs was investigated on control and DMDd45-52 myoblasts. First, we showed a decrease of nNOS expression when miR-708 or miR-34c were overexpressed in control myoblasts. We then confirmed that DMDd45-52 cells displayed an endogenous increased of miR-31, miR-708, and miR-34c and a decreased of nNOS expression, the same characteristics observed in BMDd45-55 biopsies. In DMDd45-52 cells, we demonstrated that the inhibition of miR-708

  9. Natural chalcones as dual inhibitors of HDACs and NF-κB

    PubMed Central

    ORLIKOVA, B.; SCHNEKENBURGER, M.; ZLOH, M.; GOLAIS, F.; DIEDERICH, M.; TASDEMIR, D.

    2012-01-01

    Histone deacetylase enzymes (HDACs) are emerging as a promising biological target for cancer and inflammation. Using a fluorescence assay, we tested the in vitro HDAC inhibitory activity of twenty-one natural chalcones, a widespread group of natural products with well-known anti-inflammatory and antitumor effects. Since HDACs regulate the expression of the transcription factor NF-κB, we also evaluated the inhibitory potential of the compounds on NF-κB activation. Only four chalcones, isoliquiritigenin (no. 10), butein (no. 12), homobutein (no. 15) and the glycoside marein (no. 21) showed HDAC inhibitory activity with IC50 values of 60–190 μM, whereas a number of compounds inhibited TNFα-induced NF-κB activation with IC50 values in the range of 8–41 μM. Interestingly, three chalcones (nos. 10, 12 and 15) inhibited both TNFα-induced NF-κB activity and total HDAC activity of classes I, II and IV. Molecular modeling and docking studies were performed to shed light into dual activity and to draw structure-activity relationships among chalcones (nos. 1–21). To the best of our knowledge this is the first study that provides evidence for HDACs as potential drug targets for natural chalcones. The dual inhibitory potential of the selected chalcones on NF-κB and HDACs was investigated for the first time. This study demonstrates that chalcones can serve as lead compounds in the development of dual inhibitors against both targets in the treatment of inflammation and cancer. PMID:22710558

  10. Interaction between HSP 70 and iNOS in skeletal muscle injury and repair.

    PubMed

    Kim, Kijeong

    2015-10-01

    Muscle injuries are frequently occurred in various sports. The biological process and mechanism of muscle repair after injury are well known through the many studies. This study aimed at presenting heat shock protein and nitric oxide synthase are to respond to muscle damage and repair. This section discusses the results obtained through many articles. Heat shock proteins (HSPs) are considered to play an essential role in protecting cells from damage, preparing them to survive on new environmental challenges. In addition, exercise-induced changes such as heat shock, oxidative, metabolic, muscular, and cytokine stress seem to be responsible for the HSP response to exercise. Also, inducible nitric oxide synthase (iNOS) generates nitric oxide (NO) for prolonged period and causes pathophysiological effects. Furthermore, iNOS is involved in processes such as cell injury, wound repair, embryogenesis, tissue differentiation, and suppression of tumorigenesis. In conclusion, the inhibition of HSP 70 on caspase-3 and apoptosis is associated with its inhibition on iNOS that leads to less NO production.

  11. 78 FR 39018 - Entergy Nuclear Operations, Inc.; Indian Point Nuclear Generating Unit Nos. 2 and 3

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-28

    ... NUCLEAR REGULATORY COMMISSION [Docket Nos. 50-247 and 50-286; NRC-2008-0672] Entergy Nuclear Operations, Inc.; Indian Point Nuclear Generating Unit Nos. 2 and 3 AGENCY: Nuclear Regulatory Commission... Renewal of Nuclear Plants; issuance. SUMMARY: Notice is hereby given that the U.S. Nuclear Regulatory...

  12. Understanding the Nature of Science Through a Critical and Reflective Analysis of the Controversy Between Pasteur and Liebig on Fermentation

    NASA Astrophysics Data System (ADS)

    García-Carmona, Antonio; Acevedo-Díaz, José Antonio

    2017-03-01

    This article presents a qualitative study, descriptive-interpretive in profile, of the effectiveness in learning about the nature of science (NOS) of an activity relating to the historical controversy between Pasteur and Liebig on fermentation. The activity was implemented during a course for pre-service secondary science teachers (PSSTs) specializing in physics and chemistry. The approach was explicit and reflective. Three research questions were posed: (1) What conceptions of NOS do the PSSTs show after a first reflective reading of the historical controversy?, (2) What role is played by the PSSTs' whole class critical discussion of their first reflections on the aspects of NOS dealt with in the controversy?, and (3) What changes are there in the PSSTs' conceptions of NOS after concluding the activity? The data for analysis was extracted from the PSSTs' group reports submitted at the end of the activity and the audio-recorded information from the whole class discussion. A rubric was prepared to assess this data by a process of inter-rater analysis. The results showed overall improvement in understanding the aspects of NOS involved, with there being a significant evolution in some cases (e.g., conception of scientific theory) and moderate in others (e.g., differences in scientific interpretations of the same phenomenon). This reveals that the activity has an educational utility for the education of PSSTs in NOS issues. The article concludes with an indication of some educational implications of the experience.

  13. The Effect of Reflective Discussions following Inquiry-Based Laboratory Activities on Students' Views of Nature of Science

    ERIC Educational Resources Information Center

    Yacoubian, Hagop A.; BouJaoude, Saouma

    2010-01-01

    This research investigated the effect of reflective discussions following inquiry-based laboratory activities on students' views of the tentative, empirical, subjective, and social aspects of nature of science (NOS). Thirty-eight grade six students from a Lebanese school participated in the study. The study used a pretest-posttest control-group…

  14. [Influence of hepatocyte growth factor on iNOS, NO and IL-1β in the cerebrum during cerebral ischemia/reperfusion in rats].

    PubMed

    He, Fang; Ye, Bei; Chen, Jianzhen; Sun, Xiaoyan; Li, Chang

    2014-01-01

    To explore the effect of hepatocyte growth factor (HGF) on inducible nitric oxide synthase (iNOS), NO and interleukin-1β (IL-1β) in the cerebrum of rats subjected to cerebral ischemia/reperfusion (I/R). Sprague-Dawley rats were randomly divided into 5 groups: a sham group, an I/R group,an HGF1 group, an HGF2 group, and an HGF3 group. The latter 3 groups were respectively injected 15, 30 and 60 μg/kg HGF. The focal cerebral I/R model was established by sutureoccluded method. After 1.5 h ischemia followed by 24 h reperfusion, the iNOS activity and NO content in the ischemic cerebral tissue were assessed. The expression of iNOS mRNA and IL-1β mRNA was detected. The level of iNOS protein and IL-1β content were determined. In addition, cultured cerebral cortical neurons in vitro were exposed to I/R. Then the expression of iNOS and IL-1β protein in the neurons was detected, and NO content was assessed. The iNOS activity and NO content in the ischemic cerebral tissue were increased. The expression of iNOS mRNA and IL-1β mRNA was upregulated. The level of iNOS protein and IL- 1β content were increased. Administration of HGF decreased the iNOS activity and NO content, and downregulated the expression of iNOS mRNA, IL-1β mRNA, iNOS protein and IL-1β content in the ischemic cerebral tissue. HGF decreased the expression of IL-1β, iNOS protein and NO content in the cortical neurons exposed to I/R in vitro. HGF can inhibit the expression of IL-1β and decrease the expression of iNOS and content of NO, which is probably one of the mechanisms mediating the protection of HGF against cerebral ischemia injury.

  15. A vast amount of various invariant tori in the Nosé-Hoover oscillator

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wang, Lei; Department of Mathematics and Physics, Hefei University, Hefei 230601; Yang, Xiao-Song, E-mail: yangxs@hust.edu.cn

    2015-12-15

    This letter restudies the Nosé-Hoover oscillator. Some new averagely conservative regions are found, each of which is filled with different sequences of nested tori with various knot types. Especially, the dynamical behaviors near the border of “chaotic region” and conservative regions are studied showing that there exist more complicated and thinner invariant tori around the boundaries of conservative regions bounded by tori. Our results suggest an infinite number of island chains in a “chaotic sea” for the Nosé-Hoover oscillator.

  16. Inducible nitric oxide synthase (iNOS) in gingival tissues of chronic periodontitis with and without diabetes: immunohistochemistry and RT-PCR study.

    PubMed

    Shaker, Olfat; Ghallab, Noha A; Hamdy, Ebtehal; Sayed, Safinaz

    2013-10-01

    There is few data concerning the pathogenesis and contribution of inducible nitric oxide synthase (iNOS) in the inflammatory reactions of the periodontium in the course of diabetes. This study evaluated the expression of iNOS in the gingival biopsies of periodontitis patients with and without type 2 diabetes. 80 subjects were evaluated in four groups: patients with chronic periodontitis and diabetes, patients with chronic periodontitis, periodontally healthy patients with diabetes, and systemically and periodontally healthy control subjects. Gingival biopsies were subjected to immunohistochemistry as well as reverse transcription polymerase chain reaction (RT-PCR) for determination of iNOS. All diseased gingival tissues had a significant increase in iNOS expression by immunohistochemistry (P<0.001) compared to controls. There was no significant difference observed between patients with both diabetes and periodontitis and diabetic patients regarding iNOS(+) cells. Meanwhile, these two groups had significantly increased iNOS(+) cells when compared to periodontitis patients (P<0.001). There are significantly higher levels of iNOS mRNA expression of all patient groups compared to controls (P<0.0001). In addition, samples from patients with diabetes and periodontitis showed significantly higher levels of iNOS mRNA expression compared to samples from periodontitis patients and diabetic patients (P<0.0001) yet, without noting statistically significant differences between the latter two groups. Although iNOS expression was prominent in the gingiva of patients with diabetes and periodontitis, periodontitis patients and diabetic patients, the higher mRNA for iNOS observed in diabetes and periodontitis may indicate a possible involvement of this mediator in the periodontal destruction of type 2 diabetes. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Inhibitory effect of baicalin on iNOS and NO expression in intestinal mucosa of rats with acute endotoxemia.

    PubMed

    Feng, Aiwen; Zhou, Guangrong; Yuan, Xiaoming; Huang, Xinli; Zhang, Zhengyuan; Zhang, Ti

    2013-01-01

    The mechanism by which baicalin modulated the expression of inducible nitric oxide synthase (iNOS) and nitric oxide (NO) in the mucosa of distal ileum was investigated in a rat model of acute endo-toxemia induced by intraperitoneal injection of bacterial lipopolysaccharide (LPS). The experiment demonstrated that LPS upregulated iNOS mRNA and protein expression as well as NO produc-tion (measured as the stable degradation production, nitrites). LPS not only increased toll-like receptor 4 (TLR4) and peroxisome proliferator-activated receptor gamma (PPARγ) content, but also activated p38 and activating transcription factor 2 (ATF2) and inactivated PPARγ via phosphorylation. Inhibition of p38 signalling pathway by chemical inhibitor SB202190 and small interfering RNA (siRNA) ameliorated LPS-induced iNOS generation, while suppression of PPARγ pathway by SR-202 boosted LPS-elicited iNOS expression. Baicalin treatment (I) attenuated LPS-induced iNOS mRNA and protein as well as nitrites generation, and (II) ameliorated LPS-elicited TLR4 and PPARγ production, and (III) inhibited p38/ATF2 phosphorylation leading to suppression of p38 signalling, and (IV) prevented PPARγ from phosphorylation contributing to maintainence of PPARγ bioactivity. However, SR-202 co-treatment (I) partially abrogated the inhibitory effect of baicalin on iNOS mRNA expression, and (II) partially reversed baicalin-inhibited p38 phosphorylation. In summary, baicalin could ameliorate LPS-induced iNOS and NO overproduction in mucosa of rat terminal ileum via inhibition of p38 signalling cascade and activation of PPARγ pathway. There existed a interplay between the two signalling pathways.

  18. Effect of Flooding and the nosZ Gene in Bradyrhizobia on Bradyrhizobial Community Structure in the Soil.

    PubMed

    Saeki, Yuichi; Nakamura, Misato; Mason, Maria Luisa T; Yano, Tsubasa; Shiro, Sokichi; Sameshima-Saito, Reiko; Itakura, Manabu; Minamisawa, Kiwamu; Yamamoto, Akihiro

    2017-06-24

    We investigated the effects of the water status (flooded or non-flooded) and presence of the nosZ gene in bradyrhizobia on the bradyrhizobial community structure in a factorial experiment that examined three temperature levels (20°C, 25°C, and 30°C) and two soil types (andosol and gray lowland soil) using microcosm incubations. All microcosms were inoculated with Bradyrhizobium japonicum USDA6 T , B. japonicum USDA123, and B. elkanii USDA76 T , which do not possess the nosZ gene, and then half received B. diazoefficiens USDA110 T wt (wt for the wild-type) and the other half received B. diazoefficiens USDA110ΔnosZ. USDA110 T wt possesses the nosZ gene, which encodes N 2 O reductase; 110ΔnosZ, a mutant variant, does not. Changes in the community structure after 30- and 60-d incubations were investigated by denaturing-gradient gel electrophoresis and an image analysis. USDA6 T and 76 T strains slightly increased in non-flooded soil regardless of which USDA110 T strain was present. In flooded microcosms with the USDA110 T wt strain, USDA110 T wt became dominant, whereas in microcosms with the USDA110ΔnosZ, a similar change in the community structure occurred to that in non-flooded microcosms. These results suggest that possession of the nosZ gene confers a competitive advantage to B. diazoefficiens USDA110 T in flooded soil. We herein demonstrated that the dominance of B. diazoefficiens USDA110 T wt within the soil bradyrhizobial population may be enhanced by periods of flooding or waterlogging systems such as paddy-soybean rotations because it appears to have the ability to thrive in moderately anaerobic soil.

  19. Bridging the Gap Between Preservice Early Childhood Teachers' Cultural Values, Perceptions of Values Held by Scientists, and the Relationships of These Values to Conceptions of Nature of Science

    NASA Astrophysics Data System (ADS)

    Akerson, Valarie L.; Buzzelli, Cary A.; Eastwood, Jennifer L.

    2012-02-01

    This study explored preservice teachers' views of their own cultural values, the cultural values they believed scientists hold, and the relationships of these views to their conceptions of nature of science (NOS). Parallel assignments in a foundations of early childhood education and a science methods course required preservice teachers to explore their own cultural backgrounds and their perceptions of the cultural backgrounds of scientists. The Schwartz Values Inventory was used to measure preservice teachers' personal cultural values and those they perceived of scientists. The Views of Nature of Science version B questionnaire and interviews assessed teachers' conceptions of NOS. Copies of student work were collected and sought for themes indicating how preservice teachers perceived scientists' cultural values and how those perceptions changed over time. We found that from the beginning to the end of the semester, preservice teachers perceived fewer differences between their own cultural values and those they perceived scientists held, though they did not change their own cultural values. We found that preservice teachers' NOS conceptions improved, and that they were related to both their cultural values and those they perceived scientists held. Preservice teachers who indicated the fewest differences between their own cultural values and those they perceived scientists held the most informed conceptions of NOS.

  20. [Association of Schizophrenia and its Clinical Implications with the NOS1AP Gene in the Colombian Population].

    PubMed

    Valencia, Jenny García; Duarte, Ana Victoria Valencia; Vila, Ana Lucía Páez; Kremeyer, Bárbara; Montoya, María Patricia Arbeláez; Linares, Andrés Ruiz; Acosta, Carlos Alberto Palacio; Duque, Jorge Ospina; Berrío, Gabriel Bedoya

    2012-06-01

    The nitric oxide synthase 1 adaptor protein (NOS1AP) gene is possibly implicated in schizophrenia etiopathogenesis. To determine the association of NOS1AP gene variants with schizophrenia and the relationship of variants with the clinical dimensions of the disorder in the Colombian population. It is a case-control study with 255 subjects per group. Markers within the NOS1AP gene were typified as well as other informative material of genetic origin so as to adjust by population stratification. A factorial analysis of the main components for each item in the Scales for Evaluating Negative Symptoms (SENS) together with the Scales for Evaluating Positive Symptoms (SEPS) to determine clinical dimensions. Association between the C/C genotype of the rs945713 marker with schizophrenia (OR = 1.79, 95% CI: 1.13 - 2.84) was found. The C/C genotype of the rs945713 was related to higher scores in the "affective flattening and alogia" dimension; and the A/A genotype of the rs4657181 marker was associated to lower scores in the same dimension. Significant associations of markers inside the NOS1AP gene with schizophrenia and the "affective flattening and alogia" clinical dimension were found. These results are consistent with previous studies and support the possibility that NOS1AP influences schizophrenia susceptibility. Furthermore, NOS1AP might be a modifier of schizophrenia clinical characteristics. Copyright © 2012 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

  1. New Findings in eNOS gene and Thalidomide Embryopathy Suggest pre-transcriptional effect variants as susceptibility factors

    PubMed Central

    Kowalski, Thayne Woycinck; Fraga, Lucas Rosa; Tovo-Rodrigues, Luciana; Sanseverino, Maria Teresa Vieira; Hutz, Mara Helena; Schuler-Faccini, Lavínia; Vianna, Fernanda Sales Luiz

    2016-01-01

    Antiangiogenic properties of thalidomide have created an interest in the use of the drug in treatment of cancer. However, thalidomide is responsible for thalidomide embryopathy (TE). A lack of knowledge regarding the mechanisms of thalidomide teratogenesis acts as a barrier in the aim to synthesize a safer analogue of thalidomide. Recently, our group detected a higher frequency of alleles that impair the pro-angiogenic mechanisms of endothelial nitric oxide synthase (eNOS), coded by the NOS3 gene. In this study we evaluated variable number tandem repeats (VNTR) functional polymorphism in intron 4 of NOS3 in individuals with TE (38) and Brazilians without congenital anomalies (136). Haplotypes were estimated for this VNTR with previously analyzed polymorphisms, rs2070744 (−786C > T) and rs1799983 (894T > G), in promoter region and exon 7, respectively. Haplotypic distribution was different between the groups (p = 0.007). Alleles −786C (rs2070744) and 4b (VNTR), associated with decreased NOS3 expression, presented in higher frequency in TE individuals (p = 0.018; OR = 2.57; IC = 1.2–5.8). This association was not identified with polymorphism 894T > G (p = 0.079), which influences eNOS enzymatic activity. These results suggest variants in NOS3, with pre-transcriptional effects as susceptibility factors, influencing the risk TE development. This finding generates insight for a new approach to research that pursues a safer analogue. PMID:27004986

  2. Zeb1-Hdac2-eNOS circuitry identifies early cardiovascular precursors in naive mouse embryonic stem cells.

    PubMed

    Cencioni, Chiara; Spallotta, Francesco; Savoia, Matteo; Kuenne, Carsten; Guenther, Stefan; Re, Agnese; Wingert, Susanne; Rehage, Maike; Sürün, Duran; Siragusa, Mauro; Smith, Jacob G; Schnütgen, Frank; von Melchner, Harald; Rieger, Michael A; Martelli, Fabio; Riccio, Antonella; Fleming, Ingrid; Braun, Thomas; Zeiher, Andreas M; Farsetti, Antonella; Gaetano, Carlo

    2018-03-29

    Nitric oxide (NO) synthesis is a late event during differentiation of mouse embryonic stem cells (mESC) and occurs after release from serum and leukemia inhibitory factor (LIF). Here we show that after release from pluripotency, a subpopulation of mESC, kept in the naive state by 2i/LIF, expresses endothelial nitric oxide synthase (eNOS) and endogenously synthesizes NO. This eNOS/NO-positive subpopulation (ESNO+) expresses mesendodermal markers and is more efficient in the generation of cardiovascular precursors than eNOS/NO-negative cells. Mechanistically, production of endogenous NO triggers rapid Hdac2 S-nitrosylation, which reduces association of Hdac2 with the transcriptional repression factor Zeb1, allowing mesendodermal gene expression. In conclusion, our results suggest that the interaction between Zeb1, Hdac2, and eNOS is required for early mesendodermal differentiation of naive mESC.

  3. Developing a science teacher education course that supports student teachers' thinking and teaching about the nature of science

    NASA Astrophysics Data System (ADS)

    Sorensen, Pete; Newton, Len; McCarthy, Sue

    2012-04-01

    Background and purpose . This paper reports on part of an ongoing research project in England concerning the Nature of Science (NOS). The particular focus is on the initial thinking of the graduate scientists starting a one-year, Postgraduate Certificate of Education (PGCE) course and the way the course approaches adopted influence their views and understanding of NOS and their teaching. The research is set against a wealth of literature indicating that teachers find it difficult to teach curricula that emphasise NOS. Thus a key impetus for research in this area has been to look for ways that beginning teachers might be better prepared to face such challenges. Sample The paper draws on data from three cohorts of secondary PGCE students in a university-schools partnership, involving a total of 169 students. Design and method The research lies within a design research tradition. It has used mixed methods, involving written tasks, interviews and focus groups, with an iterative approach where the outcomes from one cohort have been used to inform course developments in successive years. Results The results from these cohorts suggest that, while the students starting the course have a less restricted view of NOS than indicated by some other studies, in most cases there is a lack of breadth and depth to their understanding. There is some evidence that the use of specific tasks focusing on NOS in university-based sessions may be helping to develop and deepen understanding. However, the impact of current approaches remains fairly limited and attempts to develop teaching practices often face considerable barriers in the school-based practicum. Conclusions Graduate science students' understanding of NOS as they embark on the PGCE is not highly developed. Hence, the emphasis on aspects of NOS in the school curriculum presents a considerable challenge. This study suggests that there is a need to both further develop an explicit focus on NOS in university-based sessions and to

  4. Galilean-invariant Nosé-Hoover-type thermostats.

    PubMed

    Pieprzyk, S; Heyes, D M; Maćkowiak, Sz; Brańka, A C

    2015-03-01

    A new pairwise Nosé-Hoover type thermostat for molecular dynamics (MD) simulations which is similar in construction to the pair-velocity thermostat of Allen and Schmid, [Mol. Simul. 33, 21 (2007)] (AS) but is based on the configurational thermostat is proposed and tested. Both thermostats generate the canonical velocity distribution, are Galilean invariant, and conserve linear and angular momentum. The unique feature of the pairwise thermostats is an unconditional conservation of the total angular momentum, which is important for thermalizing isolated systems and those nonequilibrium bulk systems manifesting local rotating currents. These thermostats were benchmarked against the corresponding Nosé-Hoover (NH) and Braga-Travis prescriptions, being based on the kinetic and configurational definitions of temperature, respectively. Some differences between the shear-rate-dependent shear viscosity from Sllod nonequilibrium MD are observed at high shear rates using the different thermostats. The thermostats based on the configurational temperature produced very similar monotically decaying shear viscosity (shear thinning) with increasing shear rate, while the NH method showed discontinuous shear thinning into a string phase, and the AS method produced a continuous increase of viscosity (shear thickening), after a shear thinning region at lower shear rates. Both pairwise additive thermostats are neither purely kinetic nor configurational in definition, and possible directions for further improvement in certain aspects are discussed.

  5. Galilean-invariant Nosé-Hoover-type thermostats

    NASA Astrophysics Data System (ADS)

    Pieprzyk, S.; Heyes, D. M.; Maćkowiak, Sz.; Brańka, A. C.

    2015-03-01

    A new pairwise Nosé-Hoover type thermostat for molecular dynamics (MD) simulations which is similar in construction to the pair-velocity thermostat of Allen and Schmid, [Mol. Simul. 33, 21 (2007), 10.1080/08927020601052856] (AS) but is based on the configurational thermostat is proposed and tested. Both thermostats generate the canonical velocity distribution, are Galilean invariant, and conserve linear and angular momentum. The unique feature of the pairwise thermostats is an unconditional conservation of the total angular momentum, which is important for thermalizing isolated systems and those nonequilibrium bulk systems manifesting local rotating currents. These thermostats were benchmarked against the corresponding Nosé-Hoover (NH) and Braga-Travis prescriptions, being based on the kinetic and configurational definitions of temperature, respectively. Some differences between the shear-rate-dependent shear viscosity from Sllod nonequilibrium MD are observed at high shear rates using the different thermostats. The thermostats based on the configurational temperature produced very similar monotically decaying shear viscosity (shear thinning) with increasing shear rate, while the NH method showed discontinuous shear thinning into a string phase, and the AS method produced a continuous increase of viscosity (shear thickening), after a shear thinning region at lower shear rates. Both pairwise additive thermostats are neither purely kinetic nor configurational in definition, and possible directions for further improvement in certain aspects are discussed.

  6. eNOS uncoupling in cardiovascular diseases--the role of oxidative stress and inflammation.

    PubMed

    Karbach, Susanne; Wenzel, Philip; Waisman, Ari; Munzel, Thomas; Daiber, Andreas

    2014-01-01

    Many cardiovascular diseases and drug-induced complications are associated with - or even based on - an imbalance between the formation of reactive oxygen and nitrogen species (RONS) and antioxidant enzymes catalyzing the break-down of these harmful oxidants. According to the "kindling radical" hypothesis, the formation of RONS may trigger in certain conditions the activation of additional sources of RONS. According to recent reports, vascular dysfunction in general and cardiovascular complications such as hypertension, atherosclerosis and coronary artery diseases may be connected to inflammatory processes. The present review is focusing on the uncoupling of endothelial nitric oxide synthase (eNOS) by different mechanisms involving so-called "redox switches". The oxidative depletion of tetrahydrobiopterin (BH4), oxidative disruption of the dimeric eNOS complex, S-glutathionylation and adverse phosphorylation as well as RONS-triggered increases in levels of asymmetric dimethylarginine (ADMA) will be discussed. But also new concepts of eNOS uncoupling and state of the art detection of this process will be described. Another part of this review article will address pharmaceutical interventions preventing or reversing eNOS uncoupling and thereby normalize vascular function in a given disease setting. We finally turn our attention to the inflammatory mechanisms that are also involved in the development of endothelial dysfunction and cardiovascular disease. Inflammatory cell and cytokine profiles as well as their interactions, which are among the kindling mechanisms for the development of vascular dysfunction will be discussed on the basis of the current literature.

  7. Explicit-Reflective Teaching Nature of Science as Embedded within the Science Topic: Interactive Historical Vignettes Technique

    ERIC Educational Resources Information Center

    Nur, Erdogan Melek; Fitnat, Koseoglu

    2015-01-01

    It is obvious that more extensive work is needed in developing historical materials that address nature of science (NOS) concepts that will be implemented by teachers. Owing to the importance of meeting this need, research problem of this study is to design historical vignettes focused on the concept of chemical equilibrium which lies at the heart…

  8. Disrupting nNOS-PSD-95 coupling in the hippocampal dentate gyrus promotes extinction memory retrieval.

    PubMed

    Li, Jun; Han, Zhou; Cao, Bo; Cai, Cheng-Yun; Lin, Yu-Hui; Li, Fei; Wu, Hai-Ying; Chang, Lei; Luo, Chun-Xia; Zhu, Dong-Ya

    2017-11-04

    Granule cells in the dentate gyrus regenerate constantly in adult hippocampus and then integrate into neural circuits in the hippocampus thereby providing the neural basis for learning and memory. Promoting the neurogenesis in the hippocampus facilitates learning and memory such as spatial learning, object identification, and extinction learning. The interaction between neuronal nitric oxide synthase (nNOS) and postsynaptic density protein-95 (PSD-95) is reported to negatively regulate neurogenesis in brain, so we hypothesized that disrupting this interaction might facilitate the neurogenesis in the dentate gyrus (DG) and thus enhance the extinction memory retrieval of fear learning. We found that uncoupling the nNOS-PSD-95 complex in remote contextual fear condition promoted both neuronal proliferation and survival in the DG, contributing to an enhanced retrieval of the extinction memory. Moreover, the nNOS-PSD-95 uncoupling-induced neurogenesis may be mediated by the extracellular signal-regulated kinase (ERK) as the phosphorylation level of ERK1/2 was increased after uncoupling. These findings suggest that the nNOS-PSD-95 complex may serve as a novel target for the treatment of post-traumatic stress disorder (PTSD). Copyright © 2017 Elsevier Inc. All rights reserved.

  9. 75 FR 41237 - Public Land Order No. 7745; Partial Revocation of Power Site Reserve Nos. 510 and No. 515; Montana

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-15

    ... MTM 41534] Public Land Order No. 7745; Partial Revocation of Power Site Reserve Nos. 510 and No. 515... of public lands withdrawn for Power Site Reserve Nos. 510 and 515. This order also opens the lands to... INFORMATION: The Bureau of Land Management has determined that portions of Power Site Reserve Nos. 510 and 515...

  10. Evaluation of methylation status of the eNOS promoter at birth in relation to childhood bone mineral content

    PubMed Central

    Harvey, Nicholas C.; Lillycrop, Karen A.; Garratt, Emma; Sheppard, Allan; McLean, Cameron; Burdge, Graham; Slater-Jefferies, Jo; Rodford, Joanne; Crozier, Sarah; Inskip, Hazel; Emerald, Bright Starling; Gale, Catharine R; Hanson, Mark; Gluckman, Peter; Godfrey, Keith; Cooper, Cyrus

    2013-01-01

    Aim Our previous work has shown associations between childhood adiposity and perinatal methylation status of several genes in umbilical cord tissue, including endothelial nitric oxide synthase (eNOS). There is increasing evidence that eNOS is important in bone metabolism; we therefore related the methylation status of the eNOS gene promoter in stored umbilical cord to childhood bone size and density in a group of 9-year old children. Methods We used Sequenom MassARRAY to assess the methylation status of 2 CpGs in the eNOS promoter, identified from our previous study, in stored umbilical cords of 66 children who formed part of a Southampton birth cohort and who had measurements of bone size and density at age 9 years (Lunar DPXL DXA instrument). Results Percentage methylation varied greatly between subjects. For one of the two CpGs, eNOS chr7:150315553+, after taking account of age and sex there was a strong positive association between methylation status and the child’s whole body bone area (r=0.28,p=0.02), bone mineral content (r=0.34,p=0.005) and areal bone mineral density (r=0.34,p=0.005) at age 9 years. These associations were independent of previously documented maternal determinants of offspring bone mass. Conclusions Our findings suggest an association between methylation status at birth of a specific CpG within the eNOS promoter and bone mineral content in childhood. This supports a role for eNOS in bone growth and metabolism and implies that its contribution may at least in part occur during early skeletal development. PMID:22159788

  11. Inhibitory Effect of Baicalin on iNOS and NO Expression in Intestinal Mucosa of Rats with Acute Endotoxemia

    PubMed Central

    Yuan, Xiaoming; Huang, Xinli; Zhang, Zhengyuan; Zhang, Ti

    2013-01-01

    The mechanism by which baicalin modulated the expression of inducible nitric oxide synthase (iNOS) and nitric oxide (NO) in the mucosa of distal ileum was investigated in a rat model of acute endo-toxemia induced by intraperitoneal injection of bacterial lipopolysaccharide (LPS). The experiment demonstrated that LPS upregulated iNOS mRNA and protein expression as well as NO produc-tion (measured as the stable degradation production, nitrites). LPS not only increased toll-like receptor 4 (TLR4) and peroxisome proliferator-activated receptor gamma (PPARγ) content, but also activated p38 and activating transcription factor 2 (ATF2) and inactivated PPARγ via phosphorylation. Inhibition of p38 signalling pathway by chemical inhibitor SB202190 and small interfering RNA (siRNA) ameliorated LPS-induced iNOS generation, while suppression of PPARγ pathway by SR-202 boosted LPS-elicited iNOS expression. Baicalin treatment (I) attenuated LPS-induced iNOS mRNA and protein as well as nitrites generation, and (II) ameliorated LPS-elicited TLR4 and PPARγ production, and (III) inhibited p38/ATF2 phosphorylation leading to suppression of p38 signalling, and (IV) prevented PPARγ from phosphorylation contributing to maintainence of PPARγ bioactivity. However, SR-202 co-treatment (I) partially abrogated the inhibitory effect of baicalin on iNOS mRNA expression, and (II) partially reversed baicalin-inhibited p38 phosphorylation. In summary, baicalin could ameliorate LPS-induced iNOS and NO overproduction in mucosa of rat terminal ileum via inhibition of p38 signalling cascade and activation of PPARγ pathway. There existed a interplay between the two signalling pathways. PMID:24312512

  12. Habitual energy expenditure modifies the association between NOS3 gene polymorphisms and blood pressure.

    PubMed

    Vimaleswaran, Karani S; Franks, Paul W; Barroso, Inês; Brage, Soren; Ekelund, Ulf; Wareham, Nicholas J; Loos, Ruth J F

    2008-03-01

    The endothelial nitric-oxide synthase (NOS3) gene encodes the enzyme (eNOS) that synthesizes the molecule nitric oxide, which facilitates endothelium-dependent vasodilation in response to physical activity. Thus, energy expenditure may modify the association between the genetic variation at NOS3 and blood pressure. To test this hypothesis, we genotyped 11 NOS3 polymorphisms, capturing all common variations, in 726 men and women from the Medical Research Council (MRC) Ely Study (age (mean +/- s.d.): 55 +/- 10 years, body mass index: 26.4 +/- 4.1 kg/m(2)). Habitual/non-resting energy expenditure (NREE) was assessed via individually calibrated heart rate monitoring over 4 days. The intronic variant, IVS25+15 [G-->A], was significantly associated with blood pressure; GG homozygotes had significantly lower levels of diastolic blood pressure (DBP) (-2.8 mm Hg; P = 0.016) and systolic blood pressure (SBP) (-1.9 mm Hg; P = 0.018) than A-allele carriers. The interaction between NREE and IVS25+15 was also significant for both DBP (P = 0.006) and SBP (P = 0.026), in such a way that the effect of the GG-genotype on blood pressure was stronger in individuals with higher NREE (DBP: -4.9 mm Hg, P = 0.02. SBP: -3.8 mm Hg, P= 0.03 for the third tertile). Similar results were observed when the outcome was dichotomously defined as hypertension. In summary, the NOS3 IVS25+15 is directly associated with blood pressure and hypertension in white Europeans. However, the associations are most evident in the individuals with the highest NREE. These results need further replication and have to be ideally tested in a trial before being informative for targeted disease prevention. Eventually, the selection of individuals for lifestyle intervention programs could be guided by knowledge of genotype.

  13. Context view, Building Nos. 2728, looking north from a spot ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Context view, Building Nos. 27-28, looking north from a spot south of Building No. 28 - U.S. Veterans Hospital, Jefferson Barracks, Medical Officer in Charge Residence, VA Medical Center, Jefferson Barracks Division 1 Jefferson Barracks Drive, Saint Louis, Independent City, MO

  14. Donkey milk kefir induces apoptosis and suppresses proliferation of Ehrlich ascites carcinoma by decreasing iNOS in mice.

    PubMed

    Esener, Obb; Balkan, B M; Armutak, E I; Uvez, A; Yildiz, G; Hafizoglu, M; Yilmazer, N; Gurel-Gurevin, E

    2018-04-12

    Donkey milk and donkey milk kefir exhibit antiproliferative, antimutagenic and antibacterial effects. We investigated the effects of donkey milk and donkey milk kefir on oxidative stress, apoptosis and proliferation in Ehrlich ascites carcinoma (EAC) in mice. Thirty-four adult male Swiss albino mice were divided into four groups as follows: group 1, administered 0.5 ml water; group 2, administered 0.5 ml water + EAC cells; group 3, administered 0.5 ml donkey milk + EAC cells; group 4, administered 0.5 ml donkey milk kefir + EAC cells. We introduced 2.5 x 10 6 EAC cells into each animal by subcutaneous injection. Tap water, donkey milk and donkey milk kefir were administered by gavage for 10 days. Animals were sacrificed on day 11. After measuring the short and long diameters of the tumors, tissues were processed for histology. To determine oxidative stress, cell death and proliferation iNOS and eNOS, active caspase-3 and proliferating cell nuclear antigen were assessed using immunohistochemistry. A TUNEL assay also was used to detect apoptosis. Tumor volume decreased in the donkey milk kefir group compared to the control and donkey milk groups. Tumor volume increased in the donkey milk group compared to the control group. Proliferating cell nuclear antigen levels were higher in the donkey milk kefir group compared to the control and donkey milk groups. The number of apoptotic cells was less in the donkey milk group, compared to the control, whereas it was highest in the donkey milk kefir group. Donkey milk administration increased eNOS levels and decreased iNOS levels, compared to the control group. In the donkey milk kefir group, iNOS levels were significantly lower than those of the control and donkey milk groups, while eNOS levels were similar to the control group. Donkey milk kefir induced apoptosis, suppressed proliferation and decreased co-expression of iNOS and eNOS. Donkey milk promoted development of the tumors. Therefore, donkey milk kefir appears to

  15. NOS2 expression in glioma cell lines and glioma primary cell cultures: correlation with neurosphere generation and SOX-2 expression.

    PubMed

    Palumbo, Paola; Miconi, Gianfranca; Cinque, Benedetta; Lombardi, Francesca; La Torre, Cristina; Dehcordi, Soheila Raysi; Galzio, Renato; Cimini, Annamaria; Giordano, Antonio; Cifone, Maria Grazia

    2017-04-11

    Nitric oxide has been implicated in biology and progression of glioblastoma (GBM) being able to influence the cellular signal depending on the concentration and duration of cell exposure. NOS2 (inducible nitric oxide synthase) have been proposed as a component of molecular profile of several tumors, including glioma, one of the most aggressive primary brain tumor featuring local cancer stem cells responsible for enhanced resistance to therapies and for tumor recurrence. Here, we investigated the NOS2 mRNA expression by reverse transcription-PCR in human glioma primary cultures at several grade of malignancy and glioma stem cell (GSC) derived neurospheres. Glioma cell lines were used as positive controls both in terms of stemness marker expression that of capacity of generating neurospheres. NOS2 expression was detected at basal levels in cell lines and primary cultures and appeared significantly up-regulated in cultures kept in the specific medium for neurospheres. The immunofluorescence analysis of all cell cultures to evaluate the levels of SOX-2, a stemness marker aberrantly up-regulated in GBM, was also performed. The potential correlation between NOS2 expression and ability to generate neurospheres and between NOS2 and SOX-2 levels was also verified. The results show that the higher NOS2 expression is detected in all primary cultures able to arise neurosphere. A high and significant correlation between NOS2 expression and SOX-2 positive cells (%) in all cell cultures maintained in standard conditions has been observed. The results shed light on the potential relevance of NOS2 as a prognostic factor for glioma malignancy and recurrence.

  16. Characterization and gene expression analysis of pacu (Piaractus mesopotamicus) inducible nitric oxide synthase (iNOS) following Aeromonas dhakensis infection.

    PubMed

    Carriero, Mateus M; Henrique-Silva, Flávio; Caetano, Alexandre Rodrigues; Lobo, Francisco Pereira; Alves, Anderson Luis; Varela, Eduardo Sousa; Del Collado, Maite; Moreira, Gabriel S A; Maia, Antonio A M

    2018-03-01

    Nitric oxide (NO) is an important effector molecule which is involved in a myriad of biological processes, including immune responses against pathogens such as parasites, virus and bacteria. During the inflammatory processes in vertebrates, NO is produced by the inducible nitric oxide synthase (iNOS) enzyme in practically all nucleated cells to suppress or kill intracellular pathogens. The aim of the present study was to characterize the full coding region of the iNOS gene of pacu (Piaractus mesopotamicus), an economically and ecologically important South American fish species, and to analyze mRNA expression levels following intraperitoneal infection with the pathogenic bacterium Aeromonas dhakensis by means of quantitative real time PCR (qPCR). The results showed that the pacu iNOS transcript is 3237 bp in length, encoding a putative protein composed of 1078 amino acid residues. The amino acid sequence showed similarities ranging from 69.03% to 94.34% with other teleost fish and 57.70% with the human iNOS, with all characteristic domains and cofactor binding sites of the enzyme detected. Phylogenetic analysis showed that the iNOS from the red-bellied piranha, another South American characiform, was the closest related sequence to the pacu iNOS. iNOS transcripts were constitutively detected in the liver, spleen and head kidney, and there was a significant upregulation in the liver and spleen at 12, 24 and 48 h after infection with A. dhakensis. No significant variations were observed in the head kidney during the periods analyzed. These results show that iNOS expression was induced by A. dhakensis infection and suggest that this enzyme may be involved in the response to this bacterium in pacu. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Melatonin influences NO/NOS pathway and reduces oxidative and nitrosative stress in a model of hypoxic-ischemic brain damage.

    PubMed

    Blanco, Santos; Hernández, Raquel; Franchelli, Gustavo; Ramos-Álvarez, Manuel Miguel; Peinado, María Ángeles

    2017-01-30

    In this work, using a rat model combining ischemia and hypobaric hypoxia (IH), we evaluate the relationships between the antioxidant melatonin and the cerebral nitric oxide/nitric oxide synthase (NO/NOS) system seeking to ascertain whether melatonin exerts its antioxidant protective action by balancing this key pathway, which is highly involved in the cerebral oxidative and nitrosative damage underlying these pathologies. The application of the IH model increases the expression of the three nitric oxide synthase (NOS) isoforms, as well as nitrogen oxide (NOx) levels and nitrotyrosine (n-Tyr) impacts on the cerebral cortex. However, melatonin administration before IH makes nNOS expression response earlier and stronger, but diminishes iNOS and n-Tyr expression, while both eNOS and NOx remain unchanged. These results were corroborated by nicotine adenine dinucleotide phosphate diaphorase (NADPH-d) staining, as indicative of in situ NOS activity. In addition, the rats previously treated with melatonin exhibited a reduction in the oxidative impact evaluated by thiobarbituric acid reactive substances (TBARS). Finally, IH also intensified glial fibrillary acidic protein (GFAP) expression, reduced hypoxia-inducible factor-1alpha (HIF-1α), but did not change nuclear factor kappa B (NF-κB); meanwhile, melatonin did not significantly affect any of these patterns after the application of the IH model. The antioxidant melatonin acts on the NO/NOS system after IH injury balancing the release of NO, reducing peroxynitrite formation and protecting from nitrosative/oxidative damage. In addition, this paper raises questions concerning the classical role of some controversial molecules such as NO, which are of great consequence in the final fate of hypoxic neurons. We conclude that melatonin protects the brain from hypoxic/ischemic-derived damage in the first steps of the ischemic cascade, influencing the NO/NOS pathway and reducing oxidative and nitrosative stress. Copyright

  18. Service building. Cross section thru dry dock nos. 4 & ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Service building. Cross section thru dry dock nos. 4 & 5 showing service bldg & 20-75-150 ton cranes (dry dock associates, May 23, 1941). In files of Cushman & Wakefield, building no. 501, Philadelphia Naval Business Center. - Naval Base Philadelphia-Philadelphia Naval Shipyard, Service Building, Dry Docks No. 4 & 5, League Island, Philadelphia, Philadelphia County, PA

  19. Analysing Vee Diagram Reflections to Explore Pre-Service Science Teachers' Understanding the Nature of Science in Biology

    ERIC Educational Resources Information Center

    Savran-Gencer, Ayse

    2014-01-01

    Vee diagrams have been a metacognitive tool to help in learning the nature and structure of knowledge by reflecting on the scientific process and making knowledge much more explicit to learners during the practical work. This study aimed to assess pre-service science teachers' understanding some aspects of NOS by analyzing their reflections on the…

  20. Shear stress stimulates phosphorylation of eNOS at Ser(635) by a protein kinase A-dependent mechanism

    NASA Technical Reports Server (NTRS)

    Boo, Yong Chool; Hwang, Jinah; Sykes, Michelle; Michell, Belinda J.; Kemp, Bruce E.; Lum, Hazel; Jo, Hanjoong

    2002-01-01

    Shear stress stimulates nitric oxide (NO) production by phosphorylating endothelial NO synthase (eNOS) at Ser(1179) in a phosphoinositide-3-kinase (PI3K)- and protein kinase A (PKA)-dependent manner. The eNOS has additional potential phosphorylation sites, including Ser(116), Thr(497), and Ser(635). Here, we studied these potential phosphorylation sites in response to shear, vascular endothelial growth factor (VEGF), and 8-bromocAMP (8-BRcAMP) in bovine aortic endothelial cells (BAEC). All three stimuli induced phosphorylation of eNOS at Ser(635), which was consistently slower than that at Ser(1179). Thr(497) was rapidly dephosphorylated by 8-BRcAMP but not by shear and VEGF. None of the stimuli phosphorylated Ser(116). Whereas shear-stimulated Ser(635) phosphorylation was not affected by phosphoinositide-3-kinase inhibitors wortmannin and LY-294002, it was blocked by either treating the cells with a PKA inhibitor H89 or infecting them with a recombinant adenovirus-expressing PKA inhibitor. These results suggest that shear stress stimulates eNOS by two different mechanisms: 1) PKA- and PI3K-dependent and 2) PKA-dependent but PI3K-independent pathways. Phosphorylation of Ser(635) may play an important role in chronic regulation of eNOS in response to mechanical and humoral stimuli.