Science.gov

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. 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…

  3. 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.

  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. 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…

  6. Qualitative and quantitative immunohistochemical evaluation of iNOS expression in the spleen of dogs naturally infected with Leishmania chagasi.

    PubMed

    dos Santos, Fernando Rocha; Vieira, Paula Melo Abreu; Correa-Oliveira, Rodrigo; Giunchetti, Rodolfo Cordeiro; Carneiro, Claudia Martins; Reis, Alexandre Barbosa; Malaquias, Luiz Cosme Cotta

    2011-06-01

    Nitric oxide (NO), the product of the nitric oxide synthase enzymes has been detected in Leishmania-infected animals. Besides its role on the immunity to infection, the role of NO and the inducible nitric oxide synthase (iNOS) in the pathogenesis of canine visceral leishmaniasis (CVL) is not well understood. This study aimed at evaluating immunohistochemically the iNOS expression in the spleen of dogs naturally infected (ID) with Leishmania (L.) chagasi compared with non-infected dogs (NID). The ID was grouped according to the clinical form and the parasite load. Symptomatic dogs (SD) presented higher parasite load in relation to oligosymptomatic (OD) and asymptomatic (AD). The qualitative expression of iNOS was observed only in ID. SD presented strong and prominent labeling of iNOS, followed by OD and AD. Quantitatively, the results showed that the median expression of iNOS was higher in SD and OD compared to NID. Also, dog spleens with high parasitism load showed marked iNOS expression. Taken together, the results suggest that the expression of iNOS in the spleen of infected dogs with CVL was associated with clinical worsening of the disease and with high parasitism.

  7. Discovery of a Natural Product-Like iNOS Inhibitor by Molecular Docking with Potential Neuroprotective Effects In Vivo

    PubMed Central

    Chong, Cheong-Meng; Lu, Lihua; Wang, Modi; Chan, Daniel Shiu-Hin; Chan, Philip Wai Hong; Lee, Simon Ming-Yuen; Ma, Dik-Lung; Leung, Chung-Hang

    2014-01-01

    In this study, we applied structure-based virtual screening techniques to identify natural product or natural product-like inhibitors of iNOS. The iNOS inhibitory activity of the hit compounds was characterized using cellular assays and an in vivo zebrafish larvae model. The natural product-like compound 1 inhibited NO production in LPS-stimulated Raw264.7 macrophages, without exerting cytotoxic effects on the cells. Significantly, compound 1 was able to reverse MPTP-induced locomotion deficiency and neurotoxicity in an in vivo zebrafish larval model. Hence, compound 1 could be considered as a scaffold for the further development of iNOS inhibitors for potential anti-inflammatory or anti-neurodegenerative applications. PMID:24690920

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

    NASA Astrophysics Data System (ADS)

    Faikhamta, Chatree

    2013-04-01

    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' understanding and learning of NOS, and their orientations towards teaching it. A qualitative research approach was employed as a research methodology, drawing upon pre- and post-instruction NOS questionnaires, field notes, and in-service teachers' weekly journal entries and assignments. Open-ended NOS questionnaires, used to assess participants' understandings of NOS, were analysed and categorized as either informed, partially informed and naive. Other qualitative data were analysed through an inductive process to identify ways in-service teachers engaged and learned in the NOSC. The results indicate that at the beginning of the course, a majority of the in-service science teachers held naive understandings of NOS, particularly with respect to the definition of science, scientific inquiry, and differences between laws and theories. They viewed implicit project-based science and science process skills as goals of NOS instruction. By engaging in the course, the in-service science teachers developed an understanding of NOS and orientations to teaching NOS based on various elements, especially reflective and explicit instruction, role modelling, and content- and non-content embedded instruction. The aim of this study is to help science teacher educators, consider how to support and develop science teachers' understandings of NOS while being mindful of PCK for NOS, and develop methods for teaching NOS frameworks.

  9. Improving Chilean In-service Elementary Teachers' Understanding of Nature of Science Using Self-contained NOS and Content-Embedded Mini-Courses

    NASA Astrophysics Data System (ADS)

    Cofré, Hernán; Vergara, Claudia; Lederman, Norman G.; Lederman, Judith S.; Santibáñez, David; Jiménez, Javier; Yancovic, Macarena

    2014-11-01

    Understanding nature of science (NOS) is considered critical to the development of students' scientific literacy. However, various studies have shown that a large number of elementary and secondary science teachers do not possess an adequate understanding of NOS. This study investigated how elementary teachers' understanding of NOS was impacted through a 1-year professional development program in Chile that included NOS instruction as a theme throughout two types of mini-courses in the program. Twelve teachers attended a 1-year development program focused on improving teacher content knowledge and included the instruction of NOS embedded in two self-contained NOS mini-courses (36 h) and two lessons (3 h each) within five science content mini-courses (30 h). The Views of NOS (version D+) questionnaire and interviews were used to assess teachers' understanding of NOS at the beginning (January) and end of the program (December). Elementary teachers' understanding of the creative, inferential, and tentative aspect of NOS showed improvement. According to the teachers' perceptions, the most significant activities for improving their NOS understanding were decontextualized activities in both types of mini-courses (self-contained NOS and science content mini-courses). The implications for professional development programs are also discussed.

  10. 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,…

  11. 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

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

    SciTech Connect

    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 ilustran 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.

  13. Proposed natural gas protection program for Naval Oil Shale Reserves Nos. 1 and 3, Garfield County, Colorado

    SciTech Connect

    Not Available

    1991-08-01

    As a result of US Department of Energy (DOE) monitoring activities, it was determined in 1983 that the potential existed for natural gas resources underlying the Naval Oil Shales Reserves Nos. 1 and 3 (NOSrs-1 3) to be drained by privately-owned gas wells that were being drilled along the Reserves borders. In 1985, DOE initiated a limited number of projects to protect the Government's interest in the gas resources by drilling its own offset production'' wells just inside the boundaries, and by formally sharing in the production, revenues and costs of private wells that are drilled near the boundaries ( communitize'' the privately-drilled wells). The scope of these protection efforts must be expanded. DOE is therefore proposing a Natural Gas Protection Program for NOSRs-1 3 which would be implemented over a five-year period that would encompass a total of 200 wells (including the wells drilled and/or communitized since 1985). Of these, 111 would be offset wells drilled by DOE on Government land inside the NOSRs' boundaries and would be owned either entirely by the Government or communitized with adjacent private land owners or lessees. The remainder would be wells drilled by private operators in an area one half-mile wide extending around the NOSRs boundaries and communitized with the Government. 23 refs., 2 figs., 6 tabs.

  14. What Do Scientists Know about the Nature of Science? A Case Study of Novice Scientists' Views of NOS

    ERIC Educational Resources Information Center

    Aydeniz, Mehmet; Bilican, Kader

    2014-01-01

    The purpose of this study was to explore 15 graduate research assistants' understanding of the nature of science. Data were collected through administration of a modified version of the Views of Nature of Science Questionnaire (VNOS-C). The findings suggest that graduate research assistants held underdeveloped views related to several nature…

  15. The NOS Challenge

    ERIC Educational Resources Information Center

    Quigley, Cassie; Buck, Gayle; Akerson, Valarie

    2011-01-01

    "The picture of a scientist is me!" exclaims first grader Kendra during a nature of science (NOS) lesson. She drew a picture of a scientist and explained that she was going to be a scientist when she grew up because she "loved to observe like a scientist." Kendra's experience was a part of a 30-day unit designed specifically for first graders.…

  16. The dual role of iNOS in cancer☆

    PubMed Central

    Vanini, Frederica; Kashfi, Khosrow; Nath, Niharika

    2015-01-01

    Nitric oxide (NO) is one of the 10 smallest molecules found in nature. It is a simple gaseous free radical whose predominant functions is that of a messenger through cGMP. In mammals, NO is synthesized by the enzyme nitric oxide synthase (NOS) of which there are three isoforms. Neuronal (nNOS, NOS1) and endothelial (eNOS, NOS3) are constitutive calcium-dependent forms of the enzyme that regulate neural and vascular function respectively. The third isoform (iNOS, NOS2), is calcium-independent and is inducible. In many tumors, iNOS expression is high, however, the role of iNOS during tumor development is very complex and quite perplexing, with both promoting and inhibiting actions having been described. This review will aim to summarize the dual actions of iNOS-derived NO showing that the microenvironment of the tumor is a contributing factor to these observations and ultimately to cellular outcomes. PMID:26335399

  17. 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.

    2015-10-01

    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.

  18. 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.

  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. 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…

  1. A Comparative Study of Clam and Squid. Biting Flies of the Coastal Region. Diatoms: Nature's Aquatic Gems. Learning Experiences for Coastal and Oceanic Awareness Studies, Nos. 227, 231, 232. [Project COAST].

    ERIC Educational Resources Information Center

    Delaware Univ., Newark. Coll. of Education.

    Included are three units related to coastal and oceanic awareness. The units are: (1) A Comparative Study of Clam and Squid; (2) Biting Flies of the Coastal Region; and (3) Diatoms: Nature's Aquatic Gems. All three units were designed for secondary school students. Each unit contains teacher background materials, student activity materials,…

  2. 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…

  3. 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…

  4. 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…

  5. Teachers' Longitudinal NOS Understanding after Having Completed a Science Teacher Education Program

    ERIC Educational Resources Information Center

    Herman, Benjamin C.; Clough, Michael P.

    2016-01-01

    The study reported here investigated experienced teachers' views on several nature of science (NOS) issues 2 to 5 years after they completed a demanding secondary science teacher education program in which the NOS was an extensive and recurring component. Both quantitative and qualitative data were collected and analyzed to determine study…

  6. NOS1 — EDRN Public Portal

    Cancer.gov

    NOS1, or nitric oxide synthase 1 (neuronal), along with inducible nitric oxide synthase (NOS2) and endothelial nitric oxide synthase (NOS3), catalyze the generation of nitric oxide and L-citrulline from L-arginine and molecular oxygen. Nitric oxide is a messenger molecule with diverse functions throughout the body. In the brain and peripheral nervous system, nitric oxide displays many properties of a neurotransmitter. NOS1 also displays antimicrobial and antitumoral activities.

  7. 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…

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

    NASA Astrophysics Data System (ADS)

    Tala, Suvi; Vesterinen, Veli-Matti

    2015-05-01

    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, a worldwide consensus about the content of NOS teaching is said to be reached. This consensus content is listed as a general statement of science, which students are supposed to understand during their education. Unfortunately, decades of research has demonstrated that teachers and students alike do not possess an appropriate understanding of NOS, at least as far as it is defined at the general level. One reason for such failure might be that formal statements about the NOS and scientific knowledge can really be understood after having been contextualized in the actual cases. Typically NOS is studied as contextualized in the reconstructed historical case stories. When the objective is to educate scientifically and technologically literate citizens, as well as scientists of the near future, studying NOS in the contexts of contemporary science is encouraged. Such contextualizations call for revision of the characterization of NOS and the goals of teaching about NOS. As a consequence, this article gives two examples for studying NOS in the contexts of scientific practices with practicing scientists: an interview study with nanomodellers considering NOS in the context of their actual practices and a course on nature of scientific modelling for science teachers employing the same interview method as a studying method. Such scrutinization opens rarely discussed areas and viewpoints to NOS as well as aspects that practising scientists consider as important.

  9. 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…

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

    NASA Astrophysics Data System (ADS)

    Bayir, Eylem; Cakici, Yilmaz; Ertas, Ozge

    2014-05-01

    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 the literature generally took into consideration NOS views of only natural scientists. This study primarily proposes to explore the views of scientists in both the natural and social sciences regarding the seven target aspects of NOS. The second aim of the study is to find out the similarities and dissimilarities between the views of scientists who majored in social sciences and those who majored in natural sciences in terms of the target aspects of NOS. The sample was 69 scientists representing 5 scientific disciplines from natural and social sciences. Interviews were employed for obtaining data. The data were analyzed by means of cognitive maps. This study revealed that the scientists in the sample have neither completely informed views nor completely naïve views according to contemporary scientific understanding. Their views were a blend of the two in terms of almost all the target aspects of NOS. The views of the scientists in natural science and in social science were not substantially different. The scientists from both groups generally had similar viewpoints. This situation suggested that the scientists' views about NOS are not related to their scientific disciplines.

  12. 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,…

  13. 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…

  14. Comparison of oxygen-induced radical intermediates in iNOS oxygenase domain with those from nNOS and eNOS.

    PubMed

    Berka, Vladimír; Liu, Wen; Wu, Gang; Tsai, Ah-Lim

    2014-10-01

    Inducible nitric-oxide synthase (iNOS) produces the reactive oxygen and nitrogen species (ROS/RNS) involved in bacteria killing and is crucial in the host defense mechanism. However, high level ROS/RNS can also be detrimental to normal cells and thus their production has to be tightly controlled. Availability or deficiency of tetrahydrobiopterin (BH4) cofactor and l-arginine substrate controls coupling or uncoupling of NOS catalysis. Fully coupled reaction, with abundant BH4 and l-arginine, produces NO whereas the uncoupled NOS (in the absence of BH4 and/or l-arginine) generates ROS/RNS. In the current work we focus on direct rapid freeze EPR to characterize the structure and kinetics of oxygen-induced radical intermediates produced by ferrous inducible NOS oxygenase domain (iNOSox) in the presence or absence of BH4 and/or l-arginine. Fully reconstituted iNOSox (+BH4, +L-Arg) forms a dimer and yields a typical BH4 radical that indicates coupled reaction. iNOSox (-BH4) remains mainly monomeric and produces exclusively superoxide, that is only marginally affected by the presence of l-arginine. iNOSox (+BH4, -L-Arg) exists as a monomer/dimer mixture and yields both BH4 radical and superoxide. Present study is a natural extension of our previous work on the ferrous endothelial NOSox (eNOSox) [V. Berka, G. Wu, H.C. Yeh, G. Palmer, A.L. Tsai, J. Biol. Chem. 279 (2004) 32243-32251] and ferrous neuronal NOSox (nNOSox) [V. Berka, L.H. Wang, A.L. Tsai, Biochemistry 47 (2008) 405-420]. Overall, our data suggests different regulatory roles of l-arginine and BH4 in the production of oxygen-induced radical intermediates in NOS isoforms which nicely serve individual functional role.

  15. Expression profiles of NOS isoforms in gingiva of nNOS knockout mice.

    PubMed

    Ishioka, M; Ishizuka, Y; Shintani, S; Yanagisawa, T; Inoue, T; Sasaki, J; Watanabe, H

    2014-04-01

    Nitric oxide is a gaseous molecule associated with many distinct physiological functions, and is derived from L-arginine catalyzed by nitric oxide synthase (NOS). Nitric oxide synthase has 3 isoforms: nNOS, iNOS and eNOS. Although these NOS isoforms are believed to play an important role in gingival tissue, little information is available on their morphological dynamics. The aim of this study was to investigate the profiles of NOS isoforms in deficiency of nNOS in gingiva of mice. Twelve male (6 normal (C57BL/6) and 6 nNOS knockout) mice were used. All mice were 5-week-old, weighing approximately 20-25 g each. After sacrifice, the jaws of the mice were removed by mechanical means and specimens analyzed by histology, in situ hybridization and immunohistochemistry. Immunohistochemical observation revealed positive staining for iNOS and eNOS, especially in lamina propria. Similar results in the mRNA expression levels were shown by in situ hybridization analysis. It may suggest that iNOS and eNOS compensated nNOS deficiency in the gingiva of nNOS knockout mice.

  16. Vascular and Perivascular NO Release and Transport: Biochemical Pathways of NOS1 and NOS3

    PubMed Central

    Chen, Kejing; Popel, Aleksander S.

    2007-01-01

    Nitric oxide (NO) derived from nitric oxide synthase (NOS) is an important paracrine effector that maintains vascular tone. The release of NO mediated by NOS isozymes under various O2 conditions critically determines the NO bioavailability in tissues. Because of experimental difficulties, there has been no direct information on how enzymatic NO production and distribution change around arterioles under various oxygen conditions. In this study, we used computational models based on the analysis of biochemical pathways of enzymatic NO synthesis and the availability of NOS isozymes to quantify the NO production by neuronal NOS (NOS1) and endothelial NOS (NOS3). We compared the catalytic activities of NOS1 and NOS3 and their sensitivities to the concentration of substrate O2. Based on the NO release rates predicted from kinetic models, the geometric distribution of NO sources and mass balance analysis, we predicted the NO concentration profiles around an arteriole under various O2 conditions. The results indicated that NOS1-catalyzed NO production was significantly more sensitive to ambient O2 concentration than that catalyzed by NOS3. Also, the high sensitivity of NOS1 catalytic activity to O2 was associated with significantly reduced NO production and therefore NO concentrations, upon hypoxia. Moreover, the major source determining the distribution of NO was NOS1, which was abundantly expressed in the nerve fibers and mast cells close to arterioles, rather than NOS3, which was expressed in the endothelium. Finally, the perivascular NO concentration predicted by the models under conditions of normoxia was paradoxically at least an order of magnitude lower than a number of experimental measurements, suggesting a higher abundance of NOS1 or NOS3 and/or the existence of other enzymatic or non-enzymatic sources of NO in the microvasculature. PMID:17320763

  17. 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.

  18. 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…

  19. 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…

  20. 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…

  1. 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…

  2. An Initial Examination of Singaporean Seventh and Eighth Graders' Views of Nature of science

    ERIC Educational Resources Information Center

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

    2013-01-01

    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…

  3. mNos2 Deletion and Human NOS2 Replacement in Alzheimer Disease Models

    PubMed Central

    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.

    2014-01-01

    Abstract 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+/−/HuNOS2tg+/+/mNos2−/−) mimicked the pathologic phenotypes found in the CVN-AD strain. PMID:25003233

  4. 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.

  5. It's the nature of the beast: The influence of knowledge and intentions on learning and teaching nature of science

    NASA Astrophysics Data System (ADS)

    Schwartz, Reneé S.; Lederman, Norman G.

    2002-03-01

    This study examined the knowledge, intentions, and instructional practices of two beginning secondary science teachers as they learned the subject matter of nature of science (NOS) and attempted to teach NOS during their student teaching experience and during their first year of full-time teaching. This is a case study comparison of two success stories. However, the reasons for and levels of success are as varied as the factors that influence teaching practice. Details of the participants' progression, along with descriptions of the challenges they faced in the learning and teaching of NOS offer insight into the complexity of the fulfillment of one's instructional intentions. The results of the study suggest that depth of NOS understanding, subject-matter knowledge, and the perceived relationship between NOS and science subject matter affected the participants' learning and teaching of NOS. The views of NOS as an inherent part of all science content or as the nature of the beast facilitated the inclusion of NOS within traditional science content lessons. The participant with the more extensive science background, who also held well-developed NOS views, was better able to address NOS throughout his teaching. His subject-matter knowledge enabled him to use a variety of examples to enhance NOS instruction. The other participant's more limited subject-matter knowledge and compartmentalized view of NOS seemed to inhibit her incorporation of relevant NOS topics within a traditional science content. The importance of subject-matter knowledge, NOS knowledge, and NOS instruction intentions to the development of pedagogical content knowledge for NOS and the actualization of intentions in the classroom are discussed.

  6. 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…

  7. 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…

  8. 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,…

  9. The Relationship between Students' Views of the Nature of Science and Their Views of the Nature of Scientific Measurement

    ERIC Educational Resources Information Center

    Buffler, Andy; Lubben, Fred; Ibrahim, Bashirah

    2009-01-01

    The present study explores the relationship between students' views of the nature of science (NOS) and their views of the nature of scientific measurement. A questionnaire with two-tier diagnostic multiple-choice items on both the NOS and measurement was administered to 179 first-year physics students with diverse school experiences. Students'…

  10. 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…

  11. Professional Journals as a Source of Information about Teaching NOS: An Examination of Articles Published in Science & Children, 1996-2010

    ERIC Educational Resources Information Center

    Cite, S.; Hanuscin, D. L.

    2014-01-01

    Articles in the National Association for Science Teachers [NSTA] elementary journal "Science and Children" that describe an activity related to teaching nature of science [NOS] were analysed to ascertain the extent to which those activities align with research based suggestions for teaching NOS and the extent to which articles have…

  12. 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.

  13. 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

  14. Teaching Nature of Science to Pre-Service Early Childhood Teachers through an Explicit Reflective Approach

    ERIC Educational Resources Information Center

    Cil, Emine

    2014-01-01

    In this study, fifteen pre-service early childhood teachers' views of nature of science (NOS) were analysed. The student teachers took a course where NOS was taught via explicit reflective approach. The explicit reflective approach advocates that goal of improving students' NOS views should be planned for instead of being anticipated as…

  15. 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…

  16. 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…

  17. 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…

  18. Comparing Models of Nature of Science Dimensionality Based on the Next Generation Science Standards

    ERIC Educational Resources Information Center

    Harrison, George M.; Duncan Seraphin, Kanesa; Philippoff, Joanna; Vallin, Lisa M.; Brandon, Paul R.

    2015-01-01

    Instruments measuring understanding of the nature of science (NOS) are required if educational institutions intend to use benchmarks or examine the effects of interventions targeting students' NOS development. Compared to other constructs, NOS understanding is complex, having been the subject of debate among scholars in both its substance and its…

  19. 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,…

  20. 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…

  1. Developing a Community of Practice to Support Preservice Elementary Teachers' Nature of Science Instruction

    ERIC Educational Resources Information Center

    Akerson, Valarie L.; Donnelly, Lisa A.; Riggs, Morgan L.; Eastwood, Jennifer L.

    2012-01-01

    This study explored "To what extent will preservice teachers with adequate nature of science (NOS) conceptions and who participate in a community supporting NOS instruction teach NOS in their internship settings?" Using a combination of focus group discussions and peer feedback, five preservice teachers met with university personnel bi-monthly…

  2. 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…

  3. 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…

  4. Comparing Models of Nature of Science Dimensionality Based on the Next Generation Science Standards

    NASA Astrophysics Data System (ADS)

    Harrison, George M.; Seraphin, Kanesa Duncan; Philippoff, Joanna; Vallin, Lisa M.; Brandon, Paul R.

    2015-05-01

    Instruments measuring understanding of the nature of science (NOS) are required if educational institutions intend to use benchmarks or examine the effects of interventions targeting students' NOS development. Compared to other constructs, NOS understanding is complex, having been the subject of debate among scholars in both its substance and its dimensionality. This complexity invites challenges in defining what is to be measured. Drawing from the perspective that policy reform documents provide pragmatic consensus-based definitions of NOS, this study investigated how well the dimensionality described in the NOS component of the Next Generation Science Standards (NGSS) framework matched the empirical structure of data collected from a set of secondary-school students' responses to an NOS instrument comprising multiple-choice and Likert-scale items. Using multidimensional item response modeling to compare structures of NOS dimensionality, we found that treating NOS as comprising multiple dimensions-as defined by the themes in the NGSS NOS framework-resulted in a better fitting model than when treating NOS as a single dimension. The multidimensional model also had fewer poorly functioning items and revealed NOS profiles that otherwise would have been masked in a model treating NOS as a single dimension. These results provide support for the NOS NGSS framework and contribute to the ongoing discussion about the dimensionality of NOS.

  5. 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…

  6. 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…

  7. On the Nature of Teaching Nature of Science: Preservice Early Childhood Teachers' Instruction in Preschool and Elementary Settings

    ERIC Educational Resources Information Center

    Akerson, Valarie L.; Buzzelli, Cary A.; Donnelly, Lisa A.

    2010-01-01

    This study explored whether early childhood preservice teachers' concerns about teaching nature of science (NOS) and their intellectual levels influenced whether and how they taught NOS at the preschool and primary (K-3) levels. We used videotaped classroom observations and lesson plans to determine the science instructional practices at the…

  8. 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.

  9. 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

  10. 78 FR 19696 - Orders Granting Authority To Import and Export Natural Gas, To Import Liquefied Natural Gas, To...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-02

    ... Granting Authority To Import and Export Natural Gas, To Import Liquefied Natural Gas, To Export Liquefied Natural Gas and Vacating Prior Authority During December 2012 FE Docket Nos. DIAMOND CAPITAL INTERNATIONAL... during December 2012, it issued orders granting authority to import and export natural gas and......

  11. Characterization of iNOS+ Neutrophil-like ring cell in tumor-bearing mice

    PubMed Central

    2012-01-01

    Background Myeloid-derived Suppressor Cells (MDSC) have been identified as tumor-induced immature myeloid cells (IMC) with potent immune suppressive activity in cancer. Whereas strict phenotypic classification of MDSC has been challenging due to the highly heterogeneous nature of cell surface marker expression, use of functional markers such as Arginase and inducible nitric oxide synthase (iNOS) may represent a better categorization strategy. In this study we investigated whether iNOS could be utilized as a specific marker for the identification of a more informative homogenous MDSC subset. Methods Single-cell suspensions from tumors and other organs were prepared essentially by enzymatic digestion. Flow cytometric analysis was performed on a four-color flow cytometer. Morphology, intracellular structure and localization of iNOS+ ring cells in the tumor were determined by cytospin analysis, immunofluorescence microscopy and immunohistochemistry, respectively. For functional analysis, iNOS+ ring subset were sorted and tested in vitro cell culture experiments. Pharmacologic inhibition of iNOS was performed both in vivo and in vitro. Results The results showed that intracellular iNOS staining distinguished a granular iNOS+ SSChi CD11b+ Gr-1dim F4/80+ subset with ring-shaped nuclei (ring cells) among the CD11b+ Gr-1+ cell populations found in tumors. The intensity of the ring cell infiltrate correlated with tumor size and these cells constituted the second major tumor-infiltrating leukocyte subset found in established tumors. Although phenotypic analysis demonstrated that ring cells shared characteristics with tumor-associated macrophages (TAM), morphological analysis revealed a neutrophil-like appearance as detected by cytospin and immunofluorescence microscopy analysis. The presence of distinct iNOS filled granule-like structures located next to the cell membrane suggested that iNOS was stored in pre-formed vesicles and available for rapid release upon activation

  12. 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…

  13. 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…

  14. 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.

  15. A Scallop Nitric Oxide Synthase (NOS) with Structure Similar to Neuronal NOS and Its Involvement in the Immune Defense

    PubMed Central

    Jiang, Qiufen; Zhou, Zhi; Wang, Leilei; Wang, Lingling; Yue, Feng; Wang, Jingjing; Song, Linsheng

    2013-01-01

    Background Nitric oxide synthase (NOS) is responsible for synthesizing nitric oxide (NO) from L-arginine, and involved in multiple physiological functions. However, its immunological role in mollusc was seldom reported. Methodology In the present study, an NOS (CfNOS) gene was identified from the scallop Chlamys farreri encoding a polypeptide of 1486 amino acids. Its amino acid sequence shared 50.0~54.7, 40.7~47.0 and 42.5~44.5% similarities with vertebrate neuronal (n), endothelial (e) and inducible (i) NOSs, respectively. CfNOS contained PDZ, oxygenase and reductase domains, which resembled those in nNOS. The CfNOS mRNA transcripts expressed in all embryos and larvae after the 2-cell embryo stage, and were detectable in all tested tissues with the highest level in the gonad, and with the immune tissues hepatopancreas and haemocytes included. Moreover, the immunoreactive area of CfNOS distributed over the haemocyte cytoplasm and cell membrane. After LPS, β-glucan and PGN stimulation, the expression level of CfNOS mRNA in haemocytes increased significantly at 3 h (4.0-, 4.8- and 2.7-fold, respectively, P < 0.01), and reached the peak at 12 h (15.3- and 27.6-fold for LPS and β-glucan respectively, P < 0.01) and 24 h (17.3-fold for PGN, P < 0.01). In addition, TNF-α also induced the expression of CfNOS, which started to increase at 1 h (5.2-fold, P < 0.05) and peaked at 6 h (19.9-fold, P < 0.01). The catalytic activity of the native CfNOS protein was 30.3 ± 0.3 U mgprot-1, and it decreased significantly after the addition of the selective inhibitors of nNOS and iNOS (26.9 ± 0.4 and 29.3 ± 0.1 U mgprot-1, respectively, P < 0.01). Conclusions These results suggested that CfNOS, with identical structure with nNOS and similar enzymatic characteristics to nNOS and iNOS, played the immunological role of iNOS to be involved in the scallop immune defense against PAMPs and TNF-α. PMID:23922688

  16. Teachers' Ways of Talking About Nature of Science and Its Teaching

    NASA Astrophysics Data System (ADS)

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

    2015-11-01

    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 they talk about as possible and valuable to address in the science classroom, in Swedish compulsory school. These teachers ( N = 12) are, according to the national curriculum, expected to teach NOS, but have no specific NOS training. The analytical framework described in this article consists of five themes that include multiple perspectives on NOS. The results show that teachers have less to say when they talk about NOS teaching than when they talk about NOS in general. This difference is most obvious for issues related to different sociocultural aspects of science. Difficulties in—and advantages of—NOS teaching, as put forth by the teachers, are discussed in relation to traditional science teaching, and in relation to teachers' perspectives on for which students science teaching will be perceived as meaningful and comprehensible. The results add to understanding teachers' reasoning when confronted with the idea that NOS should be part of science teaching. This in turn provides useful information that can support the development of NOS courses for teachers.

  17. 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

  18. Regulation of eNOS-derived superoxide by endogenous methylarginines.

    PubMed

    Druhan, Lawrence J; Forbes, Scott P; Pope, Arthur J; Chen, Chun-An; Zweier, Jay L; Cardounel, Arturo J

    2008-07-08

    The endogenous methylarginines, asymmetric dimethylarginine (ADMA) and N (G)-monomethyl- l-arginine (L-NMMA) regulate nitric oxide (NO) production from endothelial NO synthase (eNOS). Under conditions of tetrahydrobiopterin (BH 4) depletion eNOS also generates (*)O 2 (-); however, the effects of methylarginines on eNOS-derived (*)O 2 (-) generation are poorly understood. Therefore, using electron paramagnetic resonance spin trapping techniques we measured the dose-dependent effects of ADMA and L-NMMA on (*)O 2 (-) production from eNOS under conditions of BH 4 depletion. In the absence of BH 4, ADMA dose-dependently increased NOS-derived (*)O 2 (-) generation, with a maximal increase of 151% at 100 microM ADMA. L-NMMA also dose-dependently increased NOS-derived (*)O 2 (-), but to a lesser extent, demonstrating a 102% increase at 100 microM L-NMMA. Moreover, the native substrate l-arginine also increased eNOS-derived (*)O 2 (-), exhibiting a similar degree of enhancement as that observed with ADMA. Measurements of NADPH consumption from eNOS demonstrated that binding of either l-arginine or methylarginines increased the rate of NADPH oxidation. Spectrophotometric studies suggest, just as for l-arginine and L-NMMA, the binding of ADMA shifts the eNOS heme to the high-spin state, indicative of a more positive heme redox potential, enabling enhanced electron transfer from the reductase to the oxygenase site. These results demonstrate that the methylarginines can profoundly shift the balance of NO and (*)O 2 (-) generation from eNOS. These observations have important implications with regard to the therapeutic use of l-arginine and the methylarginine-NOS inhibitors in the treatment of disease.

  19. Student Teachers' Attitudes Concerning Understanding the Nature of Science in Turkey

    ERIC Educational Resources Information Center

    Sahin, Nurettin; Deniz, Sabahattin; Gorgen, Izzet

    2006-01-01

    Nature of science is defined as one of the directions of scientific literacy. The main aim of this study was to investigate both secondary school social and science branch post-graduate (non-thesis master) teacher candidates attitudes about the Nature of Science (NOS) and compare their attitudes towards NOS. A 12-item Likert type scale for teacher…

  20. 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…

  1. 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 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 AND...

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

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 15 Commerce and Foreign Trade 2 2014-01-01 2014-01-01 false 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 AND...

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

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 15 Commerce and Foreign Trade 2 2013-01-01 2013-01-01 false 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 AND...

  4. 15 CFR Supplement Nos. 2-3 to Part... - [Reserved

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 15 Commerce and Foreign Trade 2 2012-01-01 2012-01-01 false 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 AND...

  5. 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 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 AND...

  6. 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…

  7. Expression of nNOS in the human larynx.

    PubMed

    Şelaru, Mircea; Rusu, Mugurel Constantin; Jianu, Adelina Maria

    2015-09-01

    Although intrinsic laryngeal neurons and ganglia have been studied in various species, they have been overlooked in humans. We aimed to investigate the presence of intrinsic laryngeal neurons in humans and, if present, to analyze their neuronal nitric oxide synthase (nNOS) expression. An immunohistochemical study using anti-nNOS antibodies was performed on samples obtained from four cadavers. Intrinsic laryngeal nNOS+ neurons were assessed in the submucosal layer, but nNOS+ nerves were found in all histological layers of the larynx. nNOS expression was also found in striated muscle fibers of larynx. This might reveal the anatomical basis of an upwards extension of the nonadrenergic noncholinergic system in human airways, but further experiments are needed to assess an exact role of NO influence on neural transmission and muscular functions of human larynx.

  8. 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

  9. DISTRIBUTION OF NOS ISOFORMS IN A PORCINE ENDOTOXIN SHOCK MODEL

    PubMed Central

    Doursout, Marie-Francoise; Oguchi, Takeshi; Fischer, Uwe M.; Liang, YangYan; Chelly, Brice; Hartley, Craig J.; Chelly, Jacques E.

    2012-01-01

    Sepsis is a major cause of morbidity and mortality. NO, an endogenous vasodilator, has been associated with the hypotension, catecholamine hyporesponsiveness, and myocardial depression of septic shock. Although iNOS is thought to be responsible for the hypotension and loss of vascular tone occurring several hours after endotoxin administration, little is known on the effects of constitutive eNOS on LPS-induced organ dysfunction. This study assessed the distribution of eNOS and iNOS in various vascular beds in conscious pigs challenged with LPS. Cardiac and regional hemodynamic parameters were recorded over 8 h in the presence and absence of aminoguanidine, a rather selective inhibitor of iNOS activity, and N-methyl-L-arginine, a nonspecific NOS inhibitor. Our data show that LPS-induced cardiac depression was associated with coronary, renal, and mesenteric vasoconstrictions and a hepatic vasodilatation. LPS also induced increases in eNOS in the heart and lungs, whereas iNOS was mostly detected in the liver. Nitrotyrosine formation was mainly detected in the lungs, with traces in the kidney, liver, and gut. Accordingly, our results suggest that the early decrease in blood pressure and cardiac depression are likely due to activated eNOS, whereas both isoforms are involved in the hepatic vasodilation. In contrast, carotid, coronary, mesenteric, and renal vasoconstrictions were significant at 5 and/or 6 h after LPS infusion, suggesting that NO is not the primary mediator, facilitating and/or unmasking the release of vasoconstrictor mediators. Consequently, developing newer tissue- or isoform-specific NOS inhibitors can lead to novel therapeutic agents in septic shock. PMID:17909454

  10. Vascular nitric oxide: Beyond eNOS.

    PubMed

    Zhao, Yingzi; Vanhoutte, Paul M; Leung, Susan W S

    2015-10-01

    As the first discovered gaseous signaling molecule, nitric oxide (NO) affects a number of cellular processes, including those involving vascular cells. This brief review summarizes the contribution of NO to the regulation of vascular tone and its sources in the blood vessel wall. NO regulates the degree of contraction of vascular smooth muscle cells mainly by stimulating soluble guanylyl cyclase (sGC) to produce cyclic guanosine monophosphate (cGMP), although cGMP-independent signaling [S-nitrosylation of target proteins, activation of sarco/endoplasmic reticulum calcium ATPase (SERCA) or production of cyclic inosine monophosphate (cIMP)] also can be involved. In the blood vessel wall, NO is produced mainly from l-arginine by the enzyme endothelial nitric oxide synthase (eNOS) but it can also be released non-enzymatically from S-nitrosothiols or from nitrate/nitrite. Dysfunction in the production and/or the bioavailability of NO characterizes endothelial dysfunction, which is associated with cardiovascular diseases such as hypertension and atherosclerosis.

  11. 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…

  12. Teaching Nature of Science to Preservice Science Teachers: A Phenomenographic Study of Chinese Teacher Educators' Conceptions

    NASA Astrophysics Data System (ADS)

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

    2013-10-01

    Drawing from the phenomenographic perspective, this study investigated Chinese science teacher educators' conceptions of teaching nature of science (NOS) to preservice science teachers through two semi-structured interviews. The subjects were twenty-four science teacher educators in the developed regions in China. Five key dimensions emerged from the data on the conceptions of teaching NOS, including value of teaching NOS, NOS content to be taught, incorporation of NOS instruction in courses, learning of NOS, and role of the teacher. While some of these dimensions share much similarity with those reported in the studies of conceptions of teaching in general, some are distinctively different, which is embedded in some unique features of teaching NOS to preservice science teachers. These key dimensions can constitute the valuable components of the module or course to train science teachers or teacher educators to teach NOS, provide a framework to interpret the practice of teaching NOS, as well as lay a foundation for probing the conceptions of teaching NOS of other groups of subjects (e.g., school teachers' conceptions of teaching NOS) or in other contexts (e.g., teaching NOS to in-service teacher).

  13. Regulation of eNOS enzyme activity by posttranslational modification.

    PubMed

    Heiss, Elke H; Dirsch, Verena M

    2014-01-01

    The regulation of endothelial NO synthase (eNOS) employs multiple different cellular control mechanisms impinging on level and activity of the enzyme. This review aims at summarizing the current knowledge on the posttranslational modifications of eNOS, including acylation, nitrosylation, phosphorylation, acetylation, glycosylation and glutathionylation. Sites, mediators and impact on enzyme localization and activity of the single modifications will be discussed. Moreover, interdependence, cooperativity and competition between the different posttranslational modifications will be elaborated with special emphasis on the susceptibility of eNOS to metabolic cues.

  14. Association of common eNOS/NOS3 polymorphisms with preeclampsia in Tunisian Arabs.

    PubMed

    Ben Ali Gannoun, Marwa; Zitouni, Hedia; Raguema, Nozha; Maleh, Wided; Gris, Jean-Christophe; Almawi, Wassim; Mahjoub, Touhami

    2015-09-15

    We investigated the association of endothelial nitric oxide synthase (NOS3) polymorphisms -786T>C, 27-bp repeat 4b/4a, and Glu298Asp with preeclampsia (PE). This was a case-control study involving 345 unrelated Tunisian women with PE and 289 unrelated age- and ethnically matched control women. The -786C allele was significantly increased in PA patients when compared to healthy controls (P=0.015). In contrast, MAF of Glu298Asp (P=0.103) and 4b/4a (P=0.168) were not significantly different between the study groups. Higher frequencies of heterozygous Glu298/298Asp and homozygous -786T/-786T genotypes were seen in PE cases compared to healthy subjects. The combination of genotypes 221 (-786T>C, Glu298Asp, 4a/4a) was more in PE cases compared with control women (17.68% vs. 8.36%; P=0.029). Multivariate regression analysis confirmed this association. Genetic variation at the NOS3 locus represents a genetic risk factor for increased susceptibility to PE.

  15. Molecular characterization of nosRZDFYLX genes coding for denitrifying nitrous oxide reductase of Bradyrhizobium japonicum.

    PubMed

    Velasco, Leonardo; Mesa, Socorro; Xu, Chang-Ai; Delgado, María J; Bedmar, Eulogio J

    2004-04-01

    The nosRZDFYLX gene cluster for the respiratory nitrous oxide reductase from Bradyrhizobium japonicum strain USDA110 has been cloned and sequenced. Seven protein coding regions corresponding to nosR, nosZ, the structural gene, nosD, nosF, nosY, nosL, and nosX were detected. The deduced amino acid sequence exhibited a high degree of similarity to other nitrous oxide reductases from various sources. The NosZ protein included a signal peptide for protein export. Mutant strains carrying either a nosZ or a nosR mutation accumulated nitrous oxide when cultured microaerobically in the presence of nitrate. Maximal expression of a P nosZ-lacZ fusion in strain USDA110 required simultaneously both low level oxygen conditions and the presence of nitrate. Microaerobic activation of the fusion required FixLJ and FixK(2).

  16. Developing Deeper Understandings of Nature of Science: The Impact of a Philosophy of Science Course on Preservice Science Teachers' Views and Instructional Planning

    ERIC Educational Resources Information Center

    Abd-El-Khalick, Fouad

    2005-01-01

    This study aimed to assess the influence of a philosophy of science (POS) course on science teachers' views of nature of science (NOS), perceptions of teaching about NOS, and instructional planning related to NOS. Participants were 56 undergraduate and graduate preservice secondary science teachers enrolled in a two science-methods course…

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

    ERIC Educational Resources Information Center

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

    2013-01-01

    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…

  18. 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…

  19. 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.

  20. eNOS/iNOS and endoplasmic reticulum stress-induced apoptosis in the placentas of patients with preeclampsia

    PubMed Central

    Du, L; He, F; Kuang, L; Tang, W; Li, Y; Chen, D

    2017-01-01

    Disruption of nitric oxide pathway and endoplasmic reticulum (ER) stress had been observed in preeclampsia (PE). However, the correlation and overall detailed expression profiles of ER stress-related markers and endothelial nitric oxide synthase/inducible nitric oxide synthase (eNOS/iNOS) in patients with PE were poorly understood. In this study, placental protein expression of ER stress-related markers as well as eNOS/iNOS in normotensive control (n=32) and PE pregnancies (n=32) was examined by western blot. In addition, apoptosis was detected by terminal deoxynucleotidyl transferase-mediated nick-end labelling (TUNEL) staining in placentas. Compared with control, we found elevated ER stress response was agreeable with iNOS upregulation in placenta tissue of PE patients. Placental protein expression of ER stress-related markers, including GRP78, GRP94, p-PERK, eIF2a, p-eIF2a, XBP1, CHOP, Ire1, p-Ire1 and iNOS, was higher, and eNOS expression was lower in PE (P<0.05 for all); however, the expression of ATF6 and PERK was similar in the PE and control groups. Upregulation of CHOP and iNOS was consistent of apoptosis increasing indicated by TUNEL staining and caspase 4 expression upregulation in PE placenta. Our datas suggest that the exaggerated ER stress response and upregulated iNOS are probably associated with increased apoptosis in placenta of PE patients and may contribute to the pathophysiology of PE. PMID:27030287

  1. Differential roles of iNOS and nNOS at rostral ventrolateral medulla during experimental endotoxemia in the rat.

    PubMed

    Chan, J Y; Wang, S H; Chan, S H

    2001-01-01

    We investigated the differential contribution of inducible and neuronal nitric oxide synthase (iNOS and nNOS) at the rostral ventrolateral medulla (RVLM) to endotoxemia induced by E. coli lipopolysaccharide (LPS). In Sprague-Dawley rats maintained under propofol anesthesia, i.v. administration of LPS (15, 30, or 45 mg/kg) induced a reduction (phase I), followed by an augmentation (phase II) and a secondary decrease (phase III) in the power density of the vasomotor components (0-0.8 Hz) in systemic arterial pressure (SAP) signals. LPS also induced an immediate hypotension, followed by a rebound increase and a secondary decrease in SAP. In addition, the level of iNOS mRNA exhibited a significant surge that began with phase I endotoxemia, reaching progressively its peak at phase III. Discernible down-regulation of nNOS mRNA was not detected until the last phase of endotoxemia. Pretreatment with microinjection of the selective iNOS inhibitor, aminoguanidine (250 pmol), into the bilateral RVLM significantly prolonged phases II and III endotoxemia, blunted the initial and secondary hypotension, and antagonized the upregulation of iNOS mRNA. Similar pretreatment with the selective nNOS inhibitor, 7-nitroindazole (1 pmol), on the other hand, discernibly shortened phase II and prolonged phase III endotoxemia, and induced progressive hypotension by antagonizing the rebound increase in SAP. We conclude that the relative prevalence of functional expression and molecular synthesis of iNOS over nNOS in the RVLM may be a crucial determinant for the reduction or loss in power density of the vasomotor components of SAP signals during experimental endotoxemia.

  2. Immunohistochemical study of constitutive neuronal and inducible nitric oxide synthase in the central nervous system of goat with natural listeriosis.

    PubMed

    Shin, T; Weinstock, D; Castro, M D; Acland, H; Walter, M; Kim, H Y; Purchase, H G

    2000-12-01

    The expression of both constitutive and inducible forms of nitric oxide synthase (NOS) was investigated by immunohistochemical staining of formalin-fixed paraffin-embedded sections in normal and Listeria monocytogenes-infected brains of goats. In normal control goats, a small number of neurons showed immunoreactivity of both iNOS and nNOS, and the number of iNOS-positive neurons was higher than the number of nNOS-positive neurons. In natural listeriosis, listeria antigens were easily immunostained in the inflammatory cells of microabscesses. In this lesion, the immunoreactivity of iNOS in neurons was more intense than the control, but nNOS was not. In microabscesses, nNOS was weakly visualized in macrophages and neutrophils, while iNOS was expressed in macrophages, but not in neutrophils. These findings suggest that normal caprine brain cells, including neurons, constitutively express iNOS and nNOS, and the expressions of these molecules is increased in Listeria monocytogenes infections. Furthermore, inflammatory cells, including macrophages, expressing both nNOS and iNOS may play important roles in the pathogenesis of bacterial meningoencephalitis in goat.

  3. Interior view of connector between Building Nos. 608 & 609 ...

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

    Interior view of connector between Building Nos. 608 & 609 (HABS CO-172-DS) facing north - Fitzsimons General Hospital, Neuropsychiatric Ward, Southeast Corner of East Nineteenth Avenue & Wheeling Street (formerly South Van Valzuh Street), Aurora, Adams County, CO

  4. 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

  5. 5. VIEW OF NORTH SECTION OF STRUCTURE SHOWING BRIDGE NOS. ...

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

    5. VIEW OF NORTH SECTION OF STRUCTURE SHOWING BRIDGE NOS. 10 AND 9 FROM CENTRAL STAIRWAY. LOOKING NORTH. - Greenville Yard, Transfer Bridge System, Port of New York/New Jersey, Upper New York Bay, Jersey City, Hudson County, NJ

  6. 6. VIEW OF SOUTH SECTION OF STRUCTURE SHOWING BRIDGE NOS. ...

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

    6. VIEW OF SOUTH SECTION OF STRUCTURE SHOWING BRIDGE NOS. 12, 13, AND 14 FROM CENTRAL STAIRWAY. LOOKING SOUTH. - Greenville Yard, Transfer Bridge System, Port of New York/New Jersey, Upper New York Bay, Jersey City, Hudson County, NJ

  7. 9. DETAIL OF BENTS NOS 3 AND 4. VIEW TO ...

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

    9. DETAIL OF BENTS NOS 3 AND 4. VIEW TO NORTH-NORTHEAST - Milwaukee Road Railroad Overpass, Spanning Chicago, Milwaukee, St. Paul, & Pacific Railroad Grade (Milwaukee Road) at Orange Street, Missoula, Missoula County, MT

  8. 11. BENTS NOS. 3 AND 2. VIEW TO SOUTHSOUTHWEST ...

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

    11. BENTS NOS. 3 AND 2. VIEW TO SOUTH-SOUTHWEST - Milwaukee Road Railroad Overpass, Spanning Chicago, Milwaukee, St. Paul, & Pacific Railroad Grade (Milwaukee Road) at Orange Street, Missoula, Missoula County, MT

  9. 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

  10. 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

  11. 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

  12. 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…

  13. 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…

  14. 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…

  15. 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…

  16. 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.

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

    ERIC Educational Resources Information Center

    Deniz, Hasan; Adibelli, Elif

    2015-01-01

    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…

  18. 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.

  19. 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.

  20. 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.

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

    NASA Astrophysics Data System (ADS)

    Thao-Do, Thi Phuong; Yuenyong, Chokchai

    2015-12-01

    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.

  2. The beneficial effects of melatonin against heart mitochondrial impairment during sepsis: inhibition of iNOS and preservation of nNOS.

    PubMed

    Ortiz, Francisco; García, José A; Acuña-Castroviejo, Darío; Doerrier, Carolina; López, Ana; Venegas, Carmen; Volt, Huayqui; Luna-Sánchez, Marta; López, Luis C; Escames, Germaine

    2014-01-01

    While it is accepted that the high production of nitric oxide (NO˙) by the inducible nitric oxide synthase (iNOS) impairs cardiac mitochondrial function during sepsis, the role of neuronal nitric oxide synthase (nNOS) may be protective. During sepsis, there is a significantly increase in the expression and activity of mitochondrial iNOS (i-mtNOS), which parallels the changes in cytosolic iNOS. The existence of a constitutive NOS form (c-mtNOS) in heart mitochondria has been also described, but its role in the heart failure during sepsis remains unclear. Herein, we analyzed the changes in mitochondrial oxidative stress and bioenergetics in wild-type and nNOS-deficient mice during sepsis, and the role of melatonin, a known antioxidant, in these changes. Sepsis was induced by cecal ligation and puncture, and heart mitochondria were analyzed for NOS expression and activity, nitrites, lipid peroxidation, glutathione and glutathione redox enzymes, oxidized proteins, and respiratory chain activity in vehicle- and melatonin-treated mice. Our data show that sepsis produced a similar induction of iNOS/i-mtNOS and comparable inhibition of the respiratory chain activity in wild-type and in nNOS-deficient mice. Sepsis also increased mitochondrial oxidative/nitrosative stress to a similar extent in both mice strains. Melatonin administration inhibited iNOS/i-mtNOS induction, restored mitochondrial homeostasis in septic mice, and preserved the activity of nNOS/c-mtNOS. The effects of melatonin were unrelated to the presence or the absence of nNOS. Our observations show a lack of effect of nNOS on heart bioenergetic impairment during sepsis and further support the beneficial actions of melatonin in sepsis.

  3. The Nature of Science in Science Education: An Introduction

    NASA Astrophysics Data System (ADS)

    McComas, William F.; Almazroa, Hiya; Clough, Michael P.

    After providing a definition of the nature of science (NOS) for science education, we argue that a pragmatic consensus exists regarding NOS topics most important for a scientifically literate society. Hence, NOS instruction should take a more prominent role in the science curriculum. While the relationship between a teacher's NOS knowledge and their pedagogical decision-making is not straight- forward, we maintain that a complex interplay does exist. While more science coursework and research experience have been suggested to improve science teachers' understanding of NOS, neither approach is empirically supported. However, explicit attempts at NOS instruction in science teacher education have been effective. This article, which is an abridged version of one appearing in McComas (1998), concludes with the suggestion of a desired state for NOS instruction.Hence, it is vital that science teachers and their students gain an understanding of the nature of science, a hybrid field blending aspects of various social studies of science such as the history, sociology and philosophy of science with research from the cognitive science into a rich and useful description of what science is and how it functions.

  4. In vitro and in vivo induction and activation of nNOS by LPS in oligodendrocytes

    PubMed Central

    Yao, SY.; Ljunggren-Rose, A.; Chandramohan, N.; Whetsell, W.O.; Sriram, S.

    2014-01-01

    There are currently four known isoforms of nitric oxide synthase (NOS). Of these, neuronal NOS (nNOS) is known to be present exclusively in neurons, endothelial NOS (eNOS) in vascular endothelium, while the inducible form of NOS (iNOS) is known to be activated in oligodendrocytes, astrocytes and microglia. The fourth isoform, mitochondrial NOS (mtNOS), represents a post translational modification of nNOS. Using western blotting and real time-PCR, we show induction and activation of nNOS following culture of oligodendrocyte progenitor cells (OPC) with lipopolysaccharide (LPS). Activation of nNOS results in accumulation of peroxynitrite and tyrosine nitration of proteins in oligodendrocytes resulting in reduced cell viability. Injection of LPS in vivo into the corpus callosum of rats leads to the development of extensive demyelination of the white matter tracts. Immunostaining of regions close to the injection site shows the presence of nNOS, but not iNOS, in oligodendrocytes. Neither iNOS nor nNOS was seen in astrocytes in areas of demyelination. These studies suggest that activation of nNOS in oligodendrocytes leads to oligodendrocyte injury resulting in demyelination. PMID:20724006

  5. 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.

  6. Nitrous Oxide Reduction Kinetics Distinguish Bacteria Harboring Clade I NosZ from Those Harboring Clade II NosZ

    PubMed Central

    Nissen, Silke; Park, Doyoung; Sanford, Robert A.

    2016-01-01

    ABSTRACT Bacteria capable of reduction of nitrous oxide (N2O) to N2 separate into clade I and clade II organisms on the basis of nos operon structures and nosZ sequence features. To explore the possible ecological consequences of distinct nos clusters, the growth of bacterial isolates with either clade I (Pseudomonas stutzeri strain DCP-Ps1, Shewanella loihica strain PV-4) or clade II (Dechloromonas aromatica strain RCB, Anaeromyxobacter dehalogenans strain 2CP-C) nosZ with N2O was examined. Growth curves did not reveal trends distinguishing the clade I and clade II organisms tested; however, the growth yields of clade II organisms exceeded those of clade I organisms by 1.5- to 1.8-fold. Further, whole-cell half-saturation constants (Kss) for N2O distinguished clade I from clade II organisms. The apparent Ks values of 0.324 ± 0.078 μM for D. aromatica and 1.34 ± 0.35 μM for A. dehalogenans were significantly lower than the values measured for P. stutzeri (35.5 ± 9.3 μM) and S. loihica (7.07 ± 1.13 μM). Genome sequencing demonstrated that Dechloromonas denitrificans possessed a clade II nosZ gene, and a measured Ks of 1.01 ± 0.18 μM for N2O was consistent with the values determined for the other clade II organisms tested. These observations provide a plausible mechanistic basis for why the relative activity of bacteria with clade I nos operons compared to that of bacteria with clade II nos operons may control N2O emissions and determine a soil's N2O sink capacity. IMPORTANCE Anthropogenic activities, in particular fertilizer application for agricultural production, increase N2O emissions to the atmosphere. N2O is a strong greenhouse gas with ozone destruction potential, and there is concern that nitrogen may become the major driver of climate change. Microbial N2O reductase (NosZ) catalyzes N2O reduction to environmentally benign dinitrogen gas and represents the major N2O sink process. The observation that bacterial groups with clade I nosZ versus those

  7. 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…

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

    ERIC Educational Resources Information Center

    McComas, William F.; Nouri, Noushin

    2016-01-01

    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…

  9. 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…

  10. 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…

  11. 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…

  12. 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…

  13. 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…

  14. 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…

  15. 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…

  16. 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…

  17. 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…

  18. 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…

  19. 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…

  20. 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…

  1. 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…

  2. 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…

  3. 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…

  4. 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…

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

    NASA Astrophysics Data System (ADS)

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

    2011-10-01

    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 students, not capable of learning NOS due to developmental unreadiness? Or would young children be capable of learning about NOS through appropriate instruction? Young children (Kindergarten through third grade) were interviewed and taught about NOS in a variety of contexts (informal, suburban, and urban) using similar teaching strategies that have been found effective at teaching about NOS with older students. These teaching strategies included explicit decontextualized and contextualized NOS instruction, through the use of children's literature, debriefings of science lessons, embedded written NOS assessments, and guided inquiries. In each context the researchers interviewed students prior to and after instruction, videotaped science instruction and maintained researcher logs and field notes, collected lesson plans, and copies of student work. The researchers found that in each setting young children did improve their understandings of NOS. Across contexts there were similar understandings of NOS aspects prior to instruction, as well as after instruction. There were also several differences evident across contexts, and across grade levels. However, it is clear that students as young as kindergarten are developmentally capable of conceptualizing NOS when it is taught to them. The authors make recommendations for teaching NOS to young children, and for future studies that explore learning progressions of NOS aspects as students proceed through school.

  6. Modulating DDAH/NOS Pathway to Discover Vasoprotective Insulin Sensitizers

    PubMed Central

    Lai, Li; Ghebremariam, Yohannes T.

    2016-01-01

    Insulin resistance syndrome (IRS) is a configuration of cardiovascular risk factors involved in the development of metabolic disorders including type 2 diabetes mellitus. In addition to diet, age, socioeconomic, and environmental factors, genetic factors that impair insulin signaling are centrally involved in the development and exacerbation of IRS. Genetic and pharmacological studies have demonstrated that the nitric oxide (NO) synthase (NOS) genes are critically involved in the regulation of insulin-mediated glucose disposal. The generation of NO by the NOS enzymes is known to contribute to vascular homeostasis including insulin-mediated skeletal muscle vasodilation and insulin sensitivity. By contrast, excessive inhibition of NOS enzymes by exogenous or endogenous factors is associated with insulin resistance (IR). Asymmetric dimethylarginine (ADMA) is an endogenous molecule that competitively inhibits all the NOS enzymes and contributes to metabolic perturbations including IR. The concentration of ADMA in plasma and tissue is enzymatically regulated by dimethylarginine dimethylaminohydrolase (DDAH), a widely expressed enzyme in the cardiovascular system. In preclinical studies, overexpression of DDAH has been shown to reduce ADMA levels, improve vascular compliance, and increase insulin sensitivity. This review discusses the feasibility of the NOS/DDAH pathway as a novel target to develop vasoprotective insulin sensitizers. PMID:26770984

  7. 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.

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

    PubMed

    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.

  9. 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,…

  10. 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…

  11. Brown Norway rats show impaired nNOS-mediated information transfer in renal autoregulation.

    PubMed

    Wang, Xuemei; Cupples, William A

    2009-01-01

    Nonselective inhibition of NO synthase (NOS) augments myogenic autoregulation of renal blood flow (RBF) and profoundly reduces RBF. Previously in Wistar rats, we showed that augmented autoregulation, but not vasoconstriction, is duplicated by intrarenal inhibition of neuronal NOS (nNOS), whereas intrarenal inhibition of inducible NOS (iNOS) has no effect on RBF or on RBF dynamics. Thus macula densa nNOS transfers information from tubuloglomerular feedback to the afferent arteriole. This information flow requires that macula densa nNOS can sufficiently alter ambient NO concentration, that is, that endothelial NOS (eNOS) and iNOS do not alter local NO concentration. Because the Brown Norway rat often shows exaggerated responses to NOS inhibition and has peculiarities of renal autoregulation that are related to NO, we used this strain to study systemic and renal vascular responses to NOS inhibition. The first experiment showed transient blood pressure reduction by bolus i.v. acetylcholine that was dose-dependent in both strains and substantially prolonged in Brown Norway rats. The depressor response decayed more rapidly after nonselective NOS inhibition and the difference between strains was lost, indicating a greater activity of eNOS in Brown Norway rats. In Brown Norway rats, selective inhibition of iNOS reduced RBF (-16% +/- 7%) and augmented myogenic autoregulation, whereas nNOS inhibition reduced RBF (-25% +/- 4%) and did not augment myogenic autoregulation. The significant responses to intrarenal iNOS inhibition, the reduced modulation of autoregulation by nNOS inhibition, and the enhanced endothelial depressor response suggest that physiological signalling by NO within the kidney is impaired in Brown Norway rats because of irrelevant or inappropriate input of NO by eNOS and iNOS.

  12. 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

  13. Natural Xanthones

    NASA Astrophysics Data System (ADS)

    Denisova-Dyatlova, O. A.; Glyzin, V. I.

    1982-10-01

    The available information on the abundance of natural xanthones in nature and the methods for the determination of their structure, biogenesis, and pharmacological properties is surveyed and described systematically. The bibliography includes 151 references.

  14. 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

  15. 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…

  16. 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.

  17. 78 FR 44940 - Orders Granting Authority To Import and Export Natural Gas, and To Import and Export Liquefied...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-25

    ... Granting Authority To Import and Export Natural Gas, and To Import and Export Liquefied Natural Gas During May 2013 FE DOCKET NOS. CASCADE NATURAL GAS CORPORATION........ 12-179-NG CASCADE NATURAL GAS... orders granting authority to import and export natural gas and to import and export liquefied......

  18. 77 FR 4028 - Orders Granting, Amending and Vacating Authority To Import and Export Natural Gas and Liquefied...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-26

    ... Granting, Amending and Vacating Authority To Import and Export Natural Gas and Liquefied Natural Gas FE Docket Nos. Gas Natural Caxitlan, S. DE R.L 11-147-NG Jordan Cove Energy Project, L.P 11-127-LNG Irving..., amending and vacating authority to import and export natural gas and liquefied natural gas. These......

  19. 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…

  20. 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.

  1. 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

  2. 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

    2017-01-01

    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 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.

  3. 78 FR 32622 - Endangered Species; File Nos. 17557 and 17273

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-31

    ...Notice is hereby given that the National Ocean Service Marine Forensic Lab (NOS Lab) [Responsible Party: M. Katherine Moore], 219 Fort Johnson Road, Charleston, SC 29412 (File No. 17557), and the NOAA Fisheries Northeast Region, Protected Resources Division [Responsible Party: Mary Colligan], 1 Blackburn Drive, Gloucester, MA 01930 (File No. 17273), have applied in due form for permits to take......

  4. 78 FR 50395 - Endangered Species; File Nos. 17557 and 17273

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-19

    ...Notice is hereby given that the National Ocean Service Marine Forensic Lab (NOS Lab) [Responsible Party: M. Katherine Moore], 219 Fort Johnson Road, Charleston, SC 29412 (File No. 17557), and the NOAA Fisheries Northeast Region, Protected Resources Division [Responsible Party: Mary Colligan], 1 Blackburn Drive, Gloucester, MA 01930 (File No. 17273), have been issued permits to take marine......

  5. First light of the NIRISS Optical Simulator (NOS)

    NASA Astrophysics Data System (ADS)

    St-Antoine, Jonathan; Albert, Loïc.; Doyon, René; Vallée, Philippe; Artigau, Étienne; Hernandez, Olivier; Thibault, Simon; Brousseau, Denis

    2016-07-01

    The Near Infrared Imager and Slitless Spectrograph (NIRISS) Optical Simulator (NOS) is a laboratory simulation of the single-object slitless spectroscopy and aperture masking interferometry modes of the NIRISS instrument onboard the James Webb Space Telescope (JWST). A transiting exoplanet can be simulated by periodically eclipsing a small portion (1% - 10ppm) of a super continuum laser source (0.4 μm - 2.4 μm) with a dichloromethane filled cell. Dichloromethane exhibits multiple absorption features in the near infrared domain hence the net effect is analogous to the atmospheric absorption features of an exoplanet transiting in front of its host star. The NOS uses an HAWAII-2RG and an ASIC controller cooled to cryogenic temperatures. A separate photometric beacon provides a flux reference to monitor laser variations. The telescope jitter can be simulated using a high-resolution motorized pinhole placed along the optical path. Laboratory transiting spectroscopy data produced by the NOS will be used to refine analysis methods, characterize the noise due to the jitter, characterize the noise floor and to develop better observation strategies. We report in this paper the first exoplanet transit event simulated by the NOS. The performance is currently limited by relatively high thermal background in the system and high frequency temporal variations of the continuum source.

  6. 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."…

  7. 4. Southwest fronts, dock nos. 491 and 492. Southeast end, ...

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

    4. Southwest fronts, dock nos. 491 and 492. Southeast end, dock no. 492. View to north. - Offutt Air Force Base, Looking Glass Airborne Command Post, Nose Docks, On either side of Hangar Access Apron at Northwest end of Project Looking Glass Historic District, Bellevue, Sarpy County, NE

  8. Airfield setting of Facility Nos. 175 and 176, taken from ...

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

    Airfield setting of Facility Nos. 175 and 176, taken from north end of Ford Island Runway, with landplane hangars on the right - U.S. Naval Base, Pearl Harbor, Landplane Hangar Type, Wasp Boulevard and Gambier Bay Street, Pearl City, Honolulu County, HI

  9. Building Nos. 92, 381, and 392, view into common courtyard ...

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

    Building Nos. 92, 381, and 392, view into common courtyard between 92 (right), 391 (center deep), and 392 (left), view facing west-northwest - U.S. Naval Base, Pearl Harbor, Marine Railway No. 1 Accessories House & Apprentice Welding School, Additions, Intersection of Avenue B & Sixth Street, Pearl City, Honolulu County, HI

  10. 50. INTERIOR OF BRIDGE SUSPENSION STRUCTURE ABOVE BRIDGE NOS. 10 ...

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

    50. INTERIOR OF BRIDGE SUSPENSION STRUCTURE ABOVE BRIDGE NOS. 10 AND 9 SHOWING CABLE COUNTERWEIGHT SYSTEM AND SCREW-TYPE VERTICAL ADJUSTMENT MACHINERY (LIFTING SCREWS). LOOKING NORTH. - Greenville Yard, Transfer Bridge System, Port of New York/New Jersey, Upper New York Bay, Jersey City, Hudson County, NJ

  11. 7. VIEW OF NORTH SECTION OF STRUCTURE SHOWING BRIDGE NOS. ...

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

    7. VIEW OF NORTH SECTION OF STRUCTURE SHOWING BRIDGE NOS. 10 AND 9 FROM BRIDGE NO. 11 APRON. LOOKING NORTH. - Greenville Yard, Transfer Bridge System, Port of New York/New Jersey, Upper New York Bay, Jersey City, Hudson County, NJ

  12. AIRMEN'S BARRACKS (FACILITY Nos. 422, 442, AND 420) IN MIDDLE ...

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

    AIRMEN'S BARRACKS (FACILITY Nos. 422, 442, AND 420) IN MIDDLE DISTANCE, ALSO SHOWING ESCOLTA AVENUE AT RIGHT, LOOKING SOUTHEAST FROM RESERVOIR HILL. (Part 2 of a 3 view panorama; see also CA-2398-4 and CA-2398-6.) - Hamilton Field, East of Nave Drive, Novato, Marin County, CA

  13. 16. Dry Dock No. 4. Longitudinal Section. Subdivision Nos. III ...

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

    16. Dry Dock No. 4. Longitudinal Section. Subdivision Nos. III and IV (Frederic R. Harris, Inc., January 10, 1941). In Files of Cushman & Wakefield, Building no. 501, Philadelphia Naval Business Center. - Naval Base Philadelphia-Philadelphia Naval Shipyard, Dry Dock No. 4, Broad Street south of Government Avenue, Philadelphia, Philadelphia County, PA

  14. 15. Dry Dock No. 4. Longitudinal Section. Subdivision Nos. I ...

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

    15. Dry Dock No. 4. Longitudinal Section. Subdivision Nos. I and II (Frederic R. Harris, Inc., January 10, 1941). In Files of Cushman & Wakefield, Building no. 501, Philadelphia Naval Business Center. - Naval Base Philadelphia-Philadelphia Naval Shipyard, Dry Dock No. 4, Broad Street south of Government Avenue, Philadelphia, Philadelphia County, PA

  15. Langley VEDIT for NOS/VE usage manual

    NASA Technical Reports Server (NTRS)

    Heaney, Margaret A.

    1987-01-01

    The use of the VEDIT editor on the CDC Network Operating System/Virtual Environment (NOS/VE) is discussed. The VEDIT, a utility, allows a user to edit files line by line (line mode). How to access and the use of VEDIT are explained. The parameters and the format of the individual commands are defined. Examples are included.

  16. Overall contextual view of Building Nos. 92, 391, and 392, ...

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

    Overall contextual view of Building Nos. 92, 391, and 392, taken from pier side, crane rails along bravo piers in foreground, palm tree and street light at right center, view facing east-northeast - U.S. Naval Base, Pearl Harbor, Marine Railway No. 1 Accessories House & Apprentice Welding School, Additions, Intersection of Avenue B & Sixth Street, Pearl City, Honolulu County, HI

  17. 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

  18. Sildenafil Ameliorates Gentamicin-Induced Nephrotoxicity in Rats: Role of iNOS and eNOS

    PubMed Central

    Morsy, Mohamed A.; Ibrahim, Salwa A.; Amin, Entesar F.; Kamel, Maha Y.; Rifaai, Rehab A.; Hassan, Magdy K.

    2014-01-01

    Gentamicin, an aminoglycoside antibiotic, is used for the treatment of serious Gram-negative infections. However, its usefulness is limited by its nephrotoxicity. Sildenafil, a selective phosphodiesterase-5 inhibitor, was reported to prevent or decrease tissue injury. The aim of this study is to evaluate the potential protective effects of sildenafil on gentamicin-induced nephrotoxicity in rats. Male Wistar rats were injected with gentamicin (100 mg/kg/day, i.p.) for 6 days with and without sildenafil. Sildenafil administration resulted in nephroprotective effect in gentamicin-intoxicated rats as it significantly decreased serum creatinine and urea, urinary albumin, and renal malondialdehyde and nitrite/nitrate levels, with a concomitant increase in renal catalase and superoxide dismutase activities compared to gentamicin-treated rats. Moreover, immunohistochemical examination revealed that sildenafil treatment markedly reduced inducible nitric oxide synthase (iNOS) expression, while expression of endothelial nitric oxide synthase (eNOS) was markedly enhanced. The protective effects of sildenafil were verified histopathologically. In conclusion, sildenafil protects rats against gentamicin-induced nephrotoxicity possibly, in part, through its antioxidant activity, inhibition of iNOS expression, and induction of eNOS production. PMID:25120567

  19. The portrayal of the nature of science in early childhood instructional materials

    NASA Astrophysics Data System (ADS)

    Schrauth, Brandon Alan

    One issue plaguing science education and science teaching is the way in which the nature of science is portrayed in science classrooms. The purpose of this study was to examine the extent to which the nature of science is presented in early childhood instructional materials and the accuracy of those NOS portrayals. This study demonstrates that the current representation of NOS is accurate but implicit in most instances. The researcher describes several implications and suggestions for further research in this area.

  20. 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.

  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. Natural occupation numbers in two-electron quantum rings

    SciTech Connect

    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.

  3. 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.

  4. Natural occupation numbers in two-electron quantum rings

    NASA Astrophysics Data System (ADS)

    Tognetti, Vincent; Loos, Pierre-François

    2016-02-01

    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.

  5. Matematica Natural.

    ERIC Educational Resources Information Center

    Lozano, Patricia; Medearis, Linda

    Matematica Natural (Natural Mathematics) is a mathematics curriculum for young children based on the assumption that they learn mathematics through concrete, real life, relevant experiences and that educational differences rather than cultural differences influence math achievement. The curriculum uses hands-on materials and activities to teach…

  6. Natural Beauty

    ERIC Educational Resources Information Center

    Coy, Mary

    2006-01-01

    In this article, the author describes how her art class students were able to create, in just four class periods, clay relief plaques depicting nature. A lesson on texture speeds up the completion of such a project. Seeing that clay is a natural material with its own unique texture, it seemed fitting that the final product should depict a variety…

  7. Firsthand Nature

    ERIC Educational Resources Information Center

    Gostev, Moses; Weiss, Francesca Michaelides

    2007-01-01

    It's no secret that many school programs don't give children enough opportunity to explore the natural world--i.e., to "mess about" and to have firsthand experience with nature and animals. Not so at the Muscota New School in New York City! This innovative public elementary school actively promotes inquiry-based learning and encourages…

  8. Nature Detectives

    ERIC Educational Resources Information Center

    Harr, Natalie; Lee, Richard E.; Jr.

    2010-01-01

    Richard Louv's "Last Child in the Woods" (2008) added to a growing consensus to get children outside and experiencing nature. Using ideas from place-based education, the authors present a simple year-long project that brings science, nature, and other curriculum standards to life right in your school yard. With a focus on journaling, this project…

  9. Characterization of the Proximal Ligand in the P420 Form of iNOS

    PubMed Central

    Sabat, Joseph; Stuehr, Dennis J.; Yeh, Syun-Ru; Rousseau, Denis L.

    2010-01-01

    The nitric oxide (NO) produced by inducible Nitric Oxide Synthase (iNOS) up-regulates the expression of heme oxygenase (HO), which in turn produces carbon monoxide (CO) that down-regulates iNOS activity by reducing its expression level or by inhibiting its activity by converting it to an inactive P420 form (iNOSP420). Accordingly, CO has been considered as a potentially important attenuator of inflammation. Despite its importance, the nature of the proximal heme ligand of the iNOSP420 species remains elusive. Here we show that the 221 cm−1 mode of the photoproduct of iNOSP420 does not exhibit any H2O-D2O solvent isotope shift such as that found in the iron-histidine stretching mode of myoglobin, indicating that the proximal ligand of iNOSP420 is not a histidine. The νFe-CO and νC-O data reveal that the proximal heme ligand of iNOSP420 is consistent with a protonated thiol, instead of a thiolate anion. Furthermore, the optical absorption properties of iNOSP420 are similar to those of a neutral thiol-heme model complex, but not myoglobin. Together the data support the scenario that iNOSP420 is inactivated by protonation of the native proximal thiolate ligand to a neutral thiol, instead of by ligand switching to a histidine, as prior studies have suggested. PMID:19658411

  10. Association of NOS2 and NOS3 gene polymorphisms with susceptibility to type 2 diabetes mellitus and diabetic nephropathy in the Chinese Han population.

    PubMed

    Chen, Feng; Li, Yu-Mei; Yang, Lin-Qing; Zhong, Cai-Gao; Zhuang, Zhi-Xiong

    2016-07-01

    Inducible nitric oxide synthase (NOS2) and endothelial nitric oxide synthase (NOS3) gene play important roles in the susceptibility to type 2 diabetes mellitus (T2DM). The present study aims to detect the potential association of NOS2 and NOS3 gene polymorphisms with the susceptibility toT2DM and diabetic nephropathy (DN) in the Chinese Han population. Four hundred and ninety T2DM patients and 485 healthy controls were enrolled in this case-control study. The genotypes of NOS2 and NOS3 gene polymorphisms were analyzed by the polymerase chain reaction (PCR)-ligase detection reaction (LDR) method. Our data demonstrated that the NOS2 rs2779248 and NOS2 rs1137933 genetic polymorphisms were significantly associated with the increased susceptibility to T2DM in the heterozygote comparison, dominant model, and allele contrast; and NOS3 rs3918188 genetic polymorphism was significantly associated with the increased susceptibility to T2DM in the homozygote comparison and recessive model. The allele-C and genotype-TC of NOS2 rs2779248, allele-A and genotype-GA of NOS2 rs1137933 and genotype-AA of NOS3 rs3918188 genetic polymorphisms might be the risk factors for increasing the susceptibility to T2DM. And a significant haplotype effect of NOS2 rs10459953/C- rs1137933/G- rs2779248/T was found between T2DM cases and controls. Moreover, NOS3 rs1800783 polymorphism was significantly associated with the increased susceptibility to DN in the heterozygote comparison, recessive model and allele contrast. At last, a positive correlation of family history of diabetes with NOS3 rs11771443 polymorphism was found in DN. These preliminary findings indicate that the NOS2 rs2779248, NOS2 rs1137933, and NOS3 rs3918188 genetic polymorphisms are potentially related to the susceptibility to T2DM, and the rs1800783 polymorphism might be considered as genetic risk factors for diabetic nephropathy, and family history of diabetes was closely associated with rs11771443 polymorphism in DN, and the

  11. Endothelial nitric oxide synthase: From biochemistry and gene structure to clinical implications of NOS3 polymorphisms.

    PubMed

    Oliveira-Paula, Gustavo H; Lacchini, Riccardo; Tanus-Santos, Jose E

    2016-01-10

    Nitric oxide (NO) is an important vasodilator with a well-established role in cardiovascular homeostasis. While mediator is synthesized from L-arginine by neuronal, endothelial, and inducible nitric oxide synthases (NOS1,NOS3 and NOS2 respectively), NOS3 is the most important isoform for NO formation in the cardiovascular system. NOS3 is a dimeric enzyme whose expression and activity are regulated at transcriptional, posttranscriptional,and posttranslational levels. The NOS3 gene, which encodes NOS3, exhibits a number of polymorphic sites including single nucleotide polymorphisms (SNPs), variable number of tandem repeats (VNTRs), microsatellites, and insertions/deletions. Some NOS3 polymorphisms show functional effects on NOS3 expression or activity, thereby affecting NO formation. Interestingly, many studies have evaluated the effects of functional NOS3 polymorphisms on disease susceptibility and drug responses. Moreover, some studies have investigated how NOS3 haplotypes may impact endogenous NO formation and disease susceptibility. In this article,we carried out a comprehensive review to provide a basic understanding of biochemical mechanisms involved in NOS3 regulation and how genetic variations in NOS3 may translate into relevant clinical and pharmacogenetic implications.

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. The Nature of Natural Languages.

    ERIC Educational Resources Information Center

    Pierce, Joe E.

    A variety of types of evidence are examined to help determine the true nature of "deep structure" and what, if any, implications this has for linguistic theory as well as culture theory generally. The evidence accumulated over the past century on the nature of phonetic and phonemic systems is briefly discussed, and the following areas of…

  17. 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…

  18. 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…

  19. 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…

  20. 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…

  1. 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…

  2. 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…

  3. 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…

  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. 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…

  6. 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.…

  7. 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…

  8. 1. Streetscape of north ends of Detention Wards, Building Nos. ...

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

    1. Streetscape of north ends of Detention Wards, Building Nos. 9946-B (left) and 9945-B (middle). Walled-in courtyard adjoins Building No. 9944-B at extreme right edge. Steam plant is in distance. This photo makes a panorama with photo WA-202-10-2. - Madigan Hospital, Detention Wards, Bounded by Wilson & McKinley Avenues & Garfield & Lincoln Streets, Tacoma, Pierce County, WA

  9. 38. View of DRS 1, 2, and 3 (structure nos. ...

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

    38. View of DRS 1, 2, and 3 (structure nos. 735, 736, and 737) console fault locator for beam power status, radio frequency (RF) and intermediate frequency (IF) fault conditions, RF switches status and TR status. - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

  10. TNFα antagonization alters NOS2 dependent nasopharyngeal carcinoma tumor growth.

    PubMed

    Bourouba, Mehdi; Zergoun, Ahmed-Amine; Maffei, Joseph S; Chila, Dalia; Djennaoui, Djamel; Asselah, Fatima; Amir-Tidadini, Zine-Charef; Touil-Boukoffa, Chafia; Zaman, Muhammad H

    2015-07-01

    Tumor necrosis factor (TNFα) is a pro-inflammatory cytokine which mediates via nitric oxide (NO) several carcinogenic processes. Increasing evidences suggest that NO promotes inflammation induced growth of nasopharyngeal carcinoma (NPC). In patients, TNFα synthesis associates with poor survival. To explore the effect of the cytokine on NO production and NOS2 dependent NPC growth, NO2(-) (nitrite) producing cells in patients were analyzed in vitro. We observed that patients' monocytes/macrophages (Mo/Ma) and primary tumor biopsies synthesized significant amounts of NO2(-). Interestingly, tumor explants derived NO2(-) levels were more important in elderly patients in comparison with juveniles. Endogenous TNFα neutralization with an anti-TNFα monoclonal antibody (mAb) successfully inhibited NO2(-) synthesis by blood mononuclear cells and tumor explants. Recombinant TNFα (rTNFα) enhanced NO2(-) synthesis and C666-1 NPC cell proliferation. NOS2 selective inhibition (1400W) and TNFα antagonization with an anti-TNFα mAb potently inhibited rTNFα induced C666-1 proliferation and NO2(-) production. Importantly, primary tumors treated with the anti-TNFα mAb also displayed reduced proliferation index (Ki67). Altogether, our results define monocytes/macrophages and the primary tumor as major sources of circulating NO2(-) in NPC patients and support the idea that antibody dependent inhibition of the TNFα/NOS2 pathway may alter NPC tumor growth.

  11. Natural disasters.

    PubMed

    Cullen, J M

    1980-09-01

    This presentation covers the various types of natural disasters which are faced by investigators throughout the world. Each geophysical substance is discussed, including earth, air and water, and secondary effects including fire. Additionally, four myths associated with disasters are reviewed.

  12. [Natural disasters].

    PubMed

    Smolka, A

    1988-07-01

    The attempt is made to illustrate the role played by natural disasters in the history of the earth and mankind by examples of past catastrophes. Subsequently, the earthquake of Tangshan/China in 1976 and the hypothetical scenario of a repeat of the 1906 San Francisco earthquake in a modern setting serve as a basis for discussion of the significance of natural disasters in modern times.

  13. 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.

  14. High Rates of Psychiatric Co-Morbidity in PDD-NOS

    ERIC Educational Resources Information Center

    de Bruin, Esther I.; Ferdinand, Robert F.; Meester, Sjifra; de Nijs, Pieter F. A.; Verheij, Fop

    2007-01-01

    Rates of co-morbid psychiatric conditions in children with Pervasive Developmental Disorder-Not Otherwise Specified (PDD-NOS) are hardly available, although these conditions are often considered as more responsive to treatment than the core symptoms of PDD-NOS. Ninety-four children with PDD-NOS, aged 6-12 years were included. The DISC-IV-P was…

  15. 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.

  16. 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...

  17. 49 CFR 173.187 - Pyrophoric solids, metals or alloys, n.o.s.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 2 2014-10-01 2014-10-01 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...

  18. 49 CFR 173.187 - Pyrophoric solids, metals or alloys, n.o.s.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 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...

  19. 49 CFR 173.187 - Pyrophoric solids, metals or alloys, n.o.s.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 2 2012-10-01 2012-10-01 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...

  20. 49 CFR 173.187 - Pyrophoric solids, metals or alloys, n.o.s.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 2 2013-10-01 2013-10-01 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...

  1. Exercise does not activate the β3 adrenergic receptor-eNOS pathway, but reduces inducible NOS expression to protect the heart of obese diabetic mice.

    PubMed

    Kleindienst, Adrien; Battault, Sylvain; Belaidi, Elise; Tanguy, Stephane; Rosselin, Marie; Boulghobra, Doria; Meyer, Gregory; Gayrard, Sandrine; Walther, Guillaume; Geny, Bernard; Durand, Gregory; Cazorla, Olivier; Reboul, Cyril

    2016-07-01

    Obesity and diabetes are associated with higher cardiac vulnerability to ischemia-reperfusion (IR). The cardioprotective effect of regular exercise has been attributed to β3-adrenergic receptor (β3AR) stimulation and increased endothelial nitric oxide synthase (eNOS) activation. Here, we evaluated the role of the β3AR-eNOS pathway and NOS isoforms in exercise-induced cardioprotection of C57Bl6 mice fed with high fat and sucrose diet (HFS) for 12 weeks and subjected or not to exercise training during the last 4 weeks (HFS-Ex). HFS animals were more sensitive to in vivo and ex vivo IR injuries than control (normal diet) and HFS-Ex mice. Cardioprotection in HFS-Ex mice was not associated with increased myocardial eNOS activation and NO metabolites storage, possibly due to the β3AR-eNOS pathway functional loss in their heart. Indeed, a selective β3AR agonist (BRL37344) increased eNOS activation and had a protective effect against IR in control, but not in HFS hearts. Moreover, iNOS expression, nitro-oxidative stress (protein s-nitrosylation and nitrotyrosination) and ROS production during early reperfusion were increased in HFS, but not in control mice. Exercise normalized iNOS level and reduced protein s-nitrosylation, nitrotyrosination and ROS production in HFS-Ex hearts during early reperfusion. The iNOS inhibitor 1400 W reduced in vivo infarct size in HFS mice to control levels, supporting the potential role of iNOS normalization in the cardioprotective effects of exercise training in HFS-Ex mice. Although the β3AR-eNOS pathway is defective in the heart of HFS mice, regular exercise can protect their heart against IR by reducing iNOS expression and nitro-oxidative stress.

  2. Transcriptional regulation of human inducible nitric oxide synthase (NOS2) gene by cytokines: initial analysis of the human NOS2 promoter.

    PubMed Central

    de Vera, M E; Shapiro, R A; Nussler, A K; Mudgett, J S; Simmons, R L; Morris, S M; Billiar, T R; Geller, D A

    1996-01-01

    The expression of inducible nitric oxide synthase (NOS2) is complex and is regulated in part by gene transcription. In this investigation we studied the regulation of NOS2 in a human liver epithelial cell line (AKN-1) which expresses high levels of NOS2 mRNA and protein in response to tumor necrosis factor alpha, interleukin 1 beta, and interferon gamma (cytokine mix, CM). Nuclear run-on analysis revealed that CM transcriptionally activated the human NOS2 gene. To delineate the cytokine-responsive regions of the human NOS2 promoter, we stimulated AKN-1 cells with CM following transfection of NOS2 luciferase constructs. Analysis of the first 3.8 kb upstream of the NOS2 gene demonstrated basal promoter activity but failed to show any cytokine-inducible activity. However, 3- to 5-fold inductions of luciferase activity were seen in constructs extending up to -5.8 and -7.0 kg, and a 10-fold increase was seen upon transfection of a -16 kb construct. Further analysis of various NOS2 luciferase constructs ligated upstream of the thymidine kinase promoter identified three regions containing cytokine-responsive elements in the human NOS2 gene: -3.8 to -5.8, -5.8 to -7.0, and -7.0 to -16 kb. These results are in marked contrast with the murine macrophage NOS2 promoter in which only 1 kb of the proximal 5' flanking region is necessary to confer inducibility to lipopolysaccharide and interferon gamma. These data demonstrate that the human NOS2 gene is transcriptionally regulated by cytokines and identify multiple cytokine-responsive regions in the 5' flanking region of the human NOS2 gene. Images Fig. 1 Fig. 2 PMID:8577713

  3. 75 FR 37389 - Marine Mammals; File Nos. 14628 and 15471

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-29

    ... purposes:National Museum of Natural History, Smithsonian Institution (Charles W. Potter, Responsible Party... Museum of Natural History (NMNH) is requesting authorization to collect, import, export, possess,...

  4. Fluorinated indazoles as novel selective inhibitors of nitric oxide synthase (NOS): synthesis and biological evaluation.

    PubMed

    Claramunt, Rosa M; López, Concepción; Pérez-Medina, Carlos; Pérez-Torralba, Marta; Elguero, José; Escames, Germaine; Acuña-Castroviejo, Darío

    2009-09-01

    In order to find new compounds with neuroprotective activity and NOS-I/NOS-II selectivity, we have designed, synthesized, and characterized 14 new NOS inhibitors with an indazole structure. The first group corresponds to 4,5,6,7-tetrahydroindazoles (4-8), the second to the N-methyl derivatives (9-12) of 7-nitro-1H-indazole (1) and 3-bromo-7-nitro-1H-indazole (2), and the latter to 4,5,6,7-tetrafluoroindazoles (13-17). Compound 13 (4,5,6,7-tetrafluoro-3-methyl-1H-indazole) inhibited NOS-I by 63% and NOS-II by 83%. Interestingly, compound 16 (4,5,6,7-tetrafluoro-3-perfluorophenyl-1H-indazole) inhibited NOS-II activity by 80%, but it did not affect to NOS-I activity. Structural comparison between these new indazoles further supports the importance of the aromatic indazole skeleton for NOS inhibition and indicate that bulky groups or N-methylation of 1 and 2 diminish their effect on NOS activity. The fluorination of the aromatic ring increased the inhibitory potency and NOS-II selectivity, suggesting that this is a promising strategy for NOS selective inhibitors.

  5. Expression of the nos operon proteins from Pseudomonas stutzeri in transgenic plants to assemble nitrous oxide reductase.

    PubMed

    Wan, Shen; Mottiar, Yaseen; Johnson, Amanda M; Goto, Kagami; Altosaar, Illimar

    2012-06-01

    Nitrous oxide (N(2)O) is a stable greenhouse gas that plays a significant role in the destruction of the ozone layer. Soils are a significant source of atmospheric N(2)O. It is important to explore some innovative and effective biology-based strategies for N(2)O mitigation. The enzyme nitrous oxide reductase (N(2)OR), naturally found in soil bacteria, is responsible for catalysing the final step of the denitrification pathway, conversion of N(2)O to dintrogen gas (N(2)). To transfer this catalytic pathway from soil into plants and amplify the abundance of this essential mechanism (to reduce global warming), a mega-cassette of five coding sequences was assembled to produce transgenic plants heterologously expressing the bacterial nos operon in plant leaves. Both the single-gene transformants (nosZ) and the multi-gene transformants (nosFLZDY) produced active recombinant N(2)OR. Enzymatic activity was detected using the methyl viologen-linked enzyme assay, showing that extracts from both types of transgenic plants exhibited N(2)O-reducing activity. Remarkably, the single-gene strategy produced higher reductase capability than the whole-operon approach. The data indicate that bacterial N(2)OR expressed in plants could convert N(2)O into inert N(2) without involvement of other Nos proteins. Silencing by homologous signal sequences, or cryptic intracellular targeting are possible explanations for the low activities obtained. Expressing N(2)OR from Pseudomonas stutzeri in single-gene transgenic plants indicated that such ag-biotech solutions to climate change have the potential to be easily incorporated into existing genetically modified organism seed germplasm.

  6. 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…

  7. 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…

  8. Science Instructors' Views of Science and Nature of Science

    ERIC Educational Resources Information Center

    Karakas, Mehmet

    2011-01-01

    This qualitative study examined how college science faculty who teach introductory level undergraduate science courses including the fields of chemistry, biology, physics, and earth science, understand and define science and nature of science (NOS). Participants were seventeen science instructors from five different institutions in the…

  9. 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…

  10. Nature's Palette

    ERIC Educational Resources Information Center

    McBride, Brooke B.; Brewer, Carol A.

    2010-01-01

    Flower petals, acorn hats, exoskeletons of beetles, and lichens are just a few of the objects students may find in a surprising array of vivid colors. These tiny examples from nature's palette can be discovered in a school yard, a park, or even along the edges of a paved sidewalk...it simply takes careful observation! This article describes a…

  11. Natural restoration

    SciTech Connect

    Kamlet, K.S.

    1993-02-01

    After a company pays millions of dollars to clean up contaminated site, its liability may not be over. It may have to spend tens of millions more to restore damaged natural resources under an oft-overlooked Superfund program. Examples of liability are cited in this report from the Exxon Valdez oil spill and a pcb leak which contaminated a harbor.

  12. Uranium, natural

    Integrated Risk Information System (IRIS)

    Uranium , natural ; CASRN 7440 - 61 - 1 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogeni

  13. Natural ecosystems

    USGS Publications Warehouse

    Fleishman, Erica; Belnap, Jayne; Cobb, Neil; Enquist, Carolyn A.F.; Ford, Karl; MacDonald, Glen; Pellant, Mike; Schoennagel, Tania; Schmit, Lara M.; Schwartz, Mark; van Drunick, Suzanne; Westerling, Anthony LeRoy; Keyser, Alisa; Lucas, Ryan

    2013-01-01

    Natural Ecosystems analyzes the association of observed changes in climate with changes in the geographic distributions and phenology (the timing of blossoms or migrations of birds) for Southwestern ecosystems and their species, portraying ecosystem disturbances—such as wildfires and outbreaks of forest pathogens—and carbon storage and release, in relation to climate change.

  14. Nature Watch

    ERIC Educational Resources Information Center

    Sterling, Donna R.

    2010-01-01

    Children are naturally curious about the world in which they live. To focus this sense of wonder, have your students investigate their local habitat as it changes over the year. This multiseason study will build connections and add relevance to the habitats that children learn about. This series of activities for grades 4-6 explores the changing…

  15. 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

  16. Isolation and chromosomal localization of the human endothelial nitric oxide synthase (NOS3) gene

    SciTech Connect

    Robinson, L.J.; Michel, T.; Weremowicz, S.; Morton, C.C. )

    1994-01-15

    Endothelial NOS activity is a major determinant of vascular tone and blood pressure, and in several important (and sometimes hereditary) disease states, such as hypertension, diabetes, and atherosclerosis, the endothelial NO signaling system appears to be abnormal. To explore the relationship of the endothelial NOS activity, the authors isolated the human gene encoding the endothelial NOS. Genomic clones containing the 5[prime] end of this gene were identified in a human genomic library by applying a polymerase chain reaction (PCR)-based approach. Identification of the human gene for endothelial NOS (NOS3) was confirmed by nucleotide sequence analysis of the first coding exon, which was found to be identical to its cognate cDNA. The NOS3 gene spans at least 20 kb and appears to contain multiple introns. The transcription start site and promoter region of the NOS3 gene were identified by primer extension and ribonuclease protection assays. Sequencing of the putative promoter revealed consensus sequences for the shear stress-response element, as well as cytokine-responsive cis regulatory sequences, both possible important to the roles played by NOS3 in the normal and the diseased cardiovascular system. The authors also mapped the chromosomal location of the NOS3 gene. First, a chromosomal panel of human-rodent somatic cell hybrids was screened using PCR with oligonucleotide primers derived from the NOS3 genomic clone. The specificity of the amplified PCR product was confirmed by human and hamster genomic DNA controls, as well as by Southern blot analysis, using the NOS3 cDNA as probe. Definitive chromosomal assignment of the NOS3 gene to human chromosome 7 was based upon 0% discordancy; fluorescence in situ hybridization sublocalized the NOS3 gene to 7q36. The identification and characterization of the NOS3 gene may lead to further insights into heritable disease states associated with this gene product. 41 refs., 3 figs., 1 tab.

  17. 14. "TEST STANDS NOS. 11, 13, & 15; MISCELLANEOUS DETAILS." ...

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

    14. "TEST STANDS NOS. 1-1, 1-3, & 1-5; MISCELLANEOUS DETAILS." Specifications No. OC12-50-10; Drawing No. 60-09-04; no sheet number within title block. D.O. SERIES 1109/22, Rev. D. Stamped: RECORD DRAWING - AS CONSTRUCTED. Below stamp: Contract DA-04-353 Eng. 177, Rev. D, no change; Date: 17 Dec. 1951. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Test Stand 1-5, Test Area 1-115, northwest end of Saturn Boulevard, Boron, Kern County, CA

  18. 11. "TEST STANDS NOS. 11, 13, & 15; CONCRETE STRUCTURAL ...

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

    11. "TEST STANDS NOS. 1-1, 1-3, & 1-5; CONCRETE STRUCTURAL SECTIONS AND DETAILS." Specifications No. OC12-50-10; Drawing No. 60-09-04; no sheet number within title block. D.O. SERIES 1109/15, Rev. E. Stamped: RECORD DRAWING - AS CONSTRUCTED. Below stamp: Contract DA-04353 Eng. 177, Rev. E; Date: 21 Dec. 1951. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Test Stand 1-5, Test Area 1-115, northwest end of Saturn Boulevard, Boron, Kern County, CA

  19. 15. "TEST STANDS NOS. 11, 13, & 15; STRUCTURAL STEEL; ...

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

    15. "TEST STANDS NOS. 1-1, 1-3, & 1-5; STRUCTURAL STEEL; PLAN & DETAILS." Specifications No. ENG 04-353-50-10; Drawing No. 60-09-04; no sheet number within title block. D.O. SERIES 1109/34, Rev. A. Stamped: RECORD DRAWING - AS CONSTRUCTED. Below stamp: Contract DA-04353 Eng. 177, Rev. A, no change; Date: 21 Dec. 1951. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Test Stand 1-5, Test Area 1-115, northwest end of Saturn Boulevard, Boron, Kern County, CA

  20. 13. "TEST STANDS NOS. 11, 13, & 15; CONCRETE STRUCTURAL ...

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

    13. "TEST STANDS NOS. 1-1, 1-3, & 1-5; CONCRETE STRUCTURAL SECTIONS AND DETAILS." Specifications No. OC12-50-10; Drawing No. 60-09-04; no sheet number within title block. D.O. SERIES 1109/18, Rev. D. Stamped: RECORD DRAWING - AS CONSTRUCTED. Below stamp: Contract DA-04353 Eng. 177, Rev. D, no change; Date: 18 Dec. 1951. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Test Stand 1-5, Test Area 1-115, northwest end of Saturn Boulevard, Boron, Kern County, CA

  1. 10. "TEST STANDS NOS. 11, 13, & 15; CONCRETE STRUCTURAL ...

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

    10. "TEST STANDS NOS. 1-1, 1-3, & 1-5; CONCRETE STRUCTURAL SECTIONS AND DETAILS." Specifications No. OC12-50-10; Drawing No. 60-09-04; no sheet number within title block. D.O. SERIES 1109/14, Rev. B. Stamped: RECORD DRAWING - AS CONSTRUCTED. Below stamp: Contract DA-04353 Eng. 177, Rev. B; Date: 21 Dec. 1951. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Test Stand 1-5, Test Area 1-115, northwest end of Saturn Boulevard, Boron, Kern County, CA

  2. 12. "TEST STANDS NOS. 11, 13, & 15; CONCRETE STRUCTURAL ...

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

    12. "TEST STANDS NOS. 1-1, 1-3, & 1-5; CONCRETE STRUCTURAL SECTIONS AND DETAILS." Specifications No. OC12-50-10; Drawing No. 60-09-06; no sheet number within title block. D.O. SERIES 1109/16, Rev. E. Stamped: RECORD DRAWING - AS CONSTRUCTED. Below stamp: Contract DA-04353 Eng. 177, Rev. E; Date: 26 Dec. 1951. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Test Stand 1-5, Test Area 1-115, northwest end of Saturn Boulevard, Boron, Kern County, CA

  3. 9. "TEST STANDS NOS. 11, 13, & 15; CONCRETE STRUCTURAL ...

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

    9. "TEST STANDS NOS. 1-1, 1-3, & 1-5; CONCRETE STRUCTURAL SECTIONS AND DETAILS." Specifications No. ENG 04-35350-10; Drawing No. 60-09-04; no sheet number within title block. D.O. SERIES 1109/13. Stamped: RECORD DRAWING - AS CONSTRUCTED. Below stamp: Contract DA-04353 Eng. 177, no change; Date: 17 Dec. 1951. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Test Stand 1-5, Test Area 1-115, northwest end of Saturn Boulevard, Boron, Kern County, CA

  4. 16. "TEST STANDS NOS. 11, 13, & 15; STRUCTURAL STEEL; ...

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

    16. "TEST STANDS NOS. 1-1, 1-3, & 1-5; STRUCTURAL STEEL; ELEVATIONS AND SECTIONS." Specifications No. ENG 04353-50-10; Drawing No. 60-09-04; no sheet number within title block. D.O. SERIES 1109/35, Rev. A. Stamped: RECORD DRAWING - AS CONSTRUCTED. Below stamp: Contract DA-04-353 Eng. 177, Rev. A; Date: 29 Dec. 1951. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Test Stand 1-5, Test Area 1-115, northwest end of Saturn Boulevard, Boron, Kern County, CA

  5. 102. Interior view of utilidor passageway link between building nos. ...

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

    102. Interior view of utilidor passageway link between building nos. 101 and 102 showing waveguides on left and cable tray system on right sides. Note fire suppression water supply piping (upper center). Small maintenance 3-wheel vehicle at center (Note: similar vehicles still in use in 2001.) Official photograph BMEWS Project by Hansen, Photographic Services, Riverton, NJ, BMEWS, clear as negative no. A-101123. - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    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 science teachers. A total of 20 NOS elements were considered by the Chinese science teacher educators to be important ideas to be taught. It was also found that among these educators, whether focusing on the classical or contemporary NOS elements in NOS instruction was a prominent controversy. After explaining the criteria for differentiating between classical and contemporary NOS elements, this paper reports the specific NOS elements suggested by Chinese science teacher educators in this study. Afterward, it describes how all educators in this study were categorized in term of NOS content taught by them to pre-service science teachers. In the end, it discusses three factors influencing the decision on NOS content to be taught, i.e., view of the concept of NOS itself, vision of teaching NOS, and belief in general philosophy.

  7. Adaptive Runge-Kutta integration for stiff systems: Comparing Nosé and Nosé-Hoover dynamics for the harmonic oscillator

    NASA Astrophysics Data System (ADS)

    Graham Hoover, William; Clinton Sprott, Julien; Griswold Hoover, Carol

    2016-10-01

    We describe the application of adaptive (variable time step) integrators to stiff differential equations encountered in many applications. Linear harmonic oscillators subject to nonlinear thermal constraints can exhibit either stiff or smooth dynamics. Two closely related examples, Nosé's dynamics and Nosé-Hoover dynamics, are both based on Hamiltonian mechanics and generate microstates consistent with Gibbs' canonical ensemble. Nosé's dynamics is stiff and can present severe numerical difficulties. Nosé-Hoover dynamics, although it follows exactly the same trajectory, is smooth and relatively trouble-free. We emphasize the power of adaptive integrators to resolve stiff problems such as the Nosé dynamics for the harmonic oscillator. The solutions also illustrate the power of computer graphics to enrich numerical solutions.

  8. 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

  9. 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.

  10. 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

  11. Nature's pumps

    NASA Astrophysics Data System (ADS)

    Vogel, Steven

    1994-10-01

    Although diverse in both form and function, the fluid-forcing devices in organisms have many of the capabilities and limitations of pumps of human design. Nature's pumps certainly look quite different from those of our technology, but all of them perform the same task. The author examines a few of these with an eye toward technological parallels and the two functional classes -- positive-displacement pumps and fluid-dynamic pumps.

  12. Satellite (Natural)

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    In its most general sense, any celestial object in orbit around a similar larger object. Thus, for example, the Magellanic Clouds are satellite galaxies of our own Milky Way galaxy. Without qualification, the term is used to mean a body in orbit around a planet; an alternative term is moon. The term natural satellite distinguishes these bodies from artificial satellites—spacecraft placed in orbi...

  13. Reversal of SIN-1-induced eNOS dysfunction by the spin trap, DMPO, in bovine aortic endothelial cells via eNOS phosphorylation

    PubMed Central

    Das, Amlan; Gopalakrishnan, Bhavani; Druhan, Lawrence J; Wang, Tse-Yao; De Pascali, Francesco; Rockenbauer, Antal; Racoma, Ira; Varadharaj, Saradhadevi; Zweier, Jay L; Cardounel, Arturo J; Villamena, Frederick A

    2014-01-01

    Background and Purpose Nitric oxide (NO) derived from eNOS is mostly responsible for the maintenance of vascular homeostasis and its decreased bioavailability is characteristic of reactive oxygen species (ROS)-induced endothelial dysfunction (ED). Because 5,5-dimethyl-1-pyrroline-N-oxide (DMPO), a commonly used spin trap, can control intracellular nitroso-redox balance by scavenging ROS and donating NO, it was employed as a cardioprotective agent against ED but the mechanism of its protection is still not clear. This study elucidated the mechanism of protection by DMPO against SIN-1-induced oxidative injury to bovine aortic endothelial cells (BAEC). Experimental Approach BAEC were treated with SIN-1, as a source of peroxynitrite anion (ONOO−), and then incubated with DMPO. Cytotoxicity following SIN-1 alone and cytoprotection by adding DMPO was assessed by MTT assay. Levels of ROS and NO generation from HEK293 cells transfected with wild-type and mutant eNOS cDNAs, tetrahydrobiopterin bioavailability, eNOS activity, eNOS and Akt kinase phosphorylation were measured. Key Results Post-treatment of cells with DMPO attenuated SIN-1-mediated cytotoxicity and ROS generation, restoration of NO levels via increased in eNOS activity and phospho-eNOS levels. Treatment with DMPO alone significantly increased NO levels and induced phosphorylation of eNOS Ser1179 via Akt kinase. Transfection studies with wild-type and mutant human eNOS confirmed the dual role of eNOS as a producer of superoxide anion (O2−) with SIN-1 treatment, and a producer of NO in the presence of DMPO. Conclusion and Implications Post-treatment with DMPO of oxidatively challenged cells reversed eNOS dysfunction and could have pharmacological implications in the treatment of cardiovascular diseases. PMID:24405159

  14. 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.

  15. On the configurational temperature Nosè-Hoover thermostat

    NASA Astrophysics Data System (ADS)

    Beckedahl, Derrick; Obaga, Emmanuel O.; Uken, Daniel A.; Sergi, Alessandro; Ferrario, Mauro

    2016-11-01

    In this paper we reformulate the configurational temperature Nosé-Hoover thermostat of Braga and Travis (2005) by means of a quasi-Hamiltonian theory in phase space Sergi and Ferrario (2001). The quasi-Hamiltonian structure is exploited to introduce a hybrid configurational-kinetic temperature Nosé-Hoover chain thermostat that can achieve a uniform sampling of phase space (also for stiff harmonic systems), as illustrated by simulating the dynamics of one-dimensional harmonic and quartic oscillators. An integration algorithm, based on the symmetric Trotter decomposition of the propagator, is presented and tested against implicit geometric algorithms with a structure similar to the velocity and position Verlet. In order to obtain an explicit form for the symmetric Trotter propagator algorithm, in the case of non-harmonic and non-linear interaction potentials, a position-dependent harmonically approximated propagator is introduced. Such a propagator approximates the dynamics of the configurational degrees of freedom as if they were locally moving in a harmonic potential. The resulting approximated locally harmonic dynamics is tested with good results in the case of a one-dimensional quartic oscillator: The integration is stable and locally time-reversible. Instead, the implicit geometric integrator is stable and time-reversible globally (when convergence is achieved). We also verify the stability of the approximated explicit integrator for a three-dimensional N-particle system interacting through a soft Weeks-Chandler-Andersen potential.

  16. Scanning capacitance detection and charge trapping in NOS

    NASA Astrophysics Data System (ADS)

    Terris, Bruce D.; Barrett, Rick; Mamin, H. Jonathon

    1993-06-01

    Charge trapping in thin films of silicon nitride has long been studied for use as a non-volatile semiconductor memory. Recently, this technology has been combined with scanned probe technologies with the sharp probe tip serving as the upper electrode in a Si3N4- SiO2Si (NOS) structure. By applying a voltage pulse between the tip and silicon substrate, charge carriers can be made to tunnel through the oxide and be trapped in the nitride. This trapped charge causes a shift in the capacitance-voltage curve along the voltage axis; the voltage at which depletion occurs is increased. It has been proposed that such a system could be used as a high density data storage device. We have begun to explore some of the issues related to such an application, including data lifetime and data rates. In thermally accelerated life tests, no sign of charge spreading was seen after 100 days at 150 degree(s)C and from the rate of charge decay we would predict room temperature lifetimes in excess of 1 million years. We have also used an air-bearing spindle to conduct high speed measurements on a spinning NOS sample and obtained data rates as high as 500 kHz with carrier-to-noise ratios of approximately 60 dB in a 3 kHz bandwidth.

  17. A configurational temperature Nosé-Hoover thermostat.

    PubMed

    Braga, Carlos; Travis, Karl P

    2005-10-01

    We propose two new thermostats which can be employed in computer simulations to ensure that two different variants of the configurational temperature fluctuate around their equilibrium values. These new thermostats differ from one previously introduced by Delhommelle and Evans [Mol. Phys. 99, 1825 (2001)] in several important ways. First, our thermostats are derived in the same spirit as the Nosé-Hoover thermostat and therefore generate the canonical phase-space distribution. Second, our thermostats involve simpler equations of motion, which do not involve spatial gradients of the configurational temperature. They do not suffer from problems stemming from stiff equations of motion and furthermore, in large temperature perturbation simulations, the measured temperature follows the set-point temperature without any overshoot, and with good damping of oscillations. We show that both of our configurational thermostats are special cases of a more general set of Nosé-Hoover equations proposed by Kusnezov et al. [Ann. Phys. 204, 155 (1990)]. The new thermostats are expected to be highly useful in nonequilibrium simulations, particularly those characterized by spatial inhomogeneities. They should also find applicability in simulations involving large changes in temperature over small time scales, such as temperature quench molecular dynamics and radiation damage modeling.

  18. 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.

  19. Coupled Nosé-Hoover lattice: A set of the Nosé-Hoover equations with different temperatures

    NASA Astrophysics Data System (ADS)

    Fukuda, Ikuo

    2016-07-01

    A simple scheme was presented to couple any number of the Nosé-Hoover equations with different heat-bath temperatures. In general, several practical procedures can be considered to realize such a coupling, where the system is under nonequilibrium. However, the current scheme provides an equilibrium distribution, namely, a smooth invariant measure for the present system. This is attained by a very simple idea, that is, a force scaling. The current scheme realizes coupled differential equations, analogous to coupled maps. Its theoretical possibilities, mathematical framework, and practical utilities are discussed. Numerical validations applying the method to a simple two-oscillator system are provided.

  20. Acacia ferruginea inhibits inflammation by regulating inflammatory iNOS and COX-2.

    PubMed

    Sakthivel, Kunnathur Murugesan; Guruvayoorappan, Chandrasekaran

    2016-01-01

    Inflammation is a local defensive reaction of a host to cellular injury or infection. Prolonged inflammation can contribute to pathogenesis of many disorders. Identification of naturally occurring phytoconstituents that can suppress inflammatory mediators can lead to the discovery of anti-inflammatory therapeutics. Acacia ferruginea is used traditionally to treat numerous ailments including hemorrhage, irritable bowel syndrome and leprosy. The present study evaluated the anti-inflammatory activity of A. ferruginea extract against acute (carrageenan) and chronic (formaldehyde) inflammation in Balb/c mice. Pre-treatment with A. ferruginea extract (10 mg/kg BW) for 5 consecutive days via intraperitonial (IP) administration significantly inhibited subsequent induction of paw edema in both models; the effects were comparable to that of the standard drug indomethacin. The results also showed the A. ferruginea extract significantly inhibited nitric oxide (NO) synthesis and iNOS expression (as measured in serum), diminished inflammation in - and neutrophil infiltration to - the paw tissues and led to a reduction in the number of COX-2(+) immunoreative cells (as evidenced by histologic and immunohistochemical analyses) in the paws relative to those in paws of mice that received the irritants only. Further, in vitro studies showed the extract could significantly scavenge free radicals generated as in DPPH and NO radical generating assays. Taken together, the results showed that A. ferruginea extract imparted potent anti-oxidant and -inflammatory effects, in part by maintaining oxidative homeostasis, inhibiting NO synthesis and suppressing iNOS and COX-2 expression and so could potentially be exploited as a potential plant-based medication against inflammatory disorders.

  1. iNOS signaling interacts with COX-2 pathway in colonic fibroblasts.

    PubMed

    Zhu, Yingting; Zhu, Min; Lance, Peter

    2012-10-01

    COX-2 and iNOS are two major inflammatory mediators implicated in colorectal inflammation and cancer. Previously, the role of colorectal fibroblasts involved in regulation of COX-2 and iNOS expression was largely ignored. In addition, the combined interaction of COX-2 and iNOS signalings and their significance in the progression of colorectal inflammation and cancer within the fibroblasts have received little investigation. To address those issues, we investigated the role of colonic fibroblasts in the regulation of COX-2 and iNOS gene expression, and explored possible mechanisms of interaction between COX-2 and iNOS signalings using a colonic CCD-18Co fibroblast line and LPS, a potential stimulator of COX-2 and iNOS. Our results clearly demonstrated that LPS activated COX-2 gene expression and enhanced PGE(2) production, stimulated iNOS gene expression and promoted NO production in the fibroblasts. Interestingly, activation of COX-2 signaling by LPS was not involved in activation of iNOS signaling, while activation of iNOS signaling by LPS contributed in part to activation of COX-2 signaling. Further analysis indicated that PKC plays a major role in the activation and interaction of COX-2 and iNOS signalings induced by LPS in the fibroblasts.

  2. Expression of inducible nitric oxide synthase (iNOS) in microglia of the developing quail retina.

    PubMed

    Sierra, Ana; Navascués, Julio; Cuadros, Miguel A; Calvente, Ruth; Martín-Oliva, David; Ferrer-Martín, Rosa M; Martín-Estebané, María; Carrasco, María-Carmen; Marín-Teva, José L

    2014-01-01

    Inducible nitric oxide synthase (iNOS), which produce large amounts of nitric oxide (NO), is induced in macrophages and microglia in response to inflammatory mediators such as LPS and cytokines. Although iNOS is mainly expressed by microglia that become activated in different pathological and experimental situations, it was recently reported that undifferentiated amoeboid microglia can also express iNOS during normal development. The aim of this study was to investigate the pattern of iNOS expression in microglial cells during normal development and after their activation with LPS by using the quail retina as model. iNOS expression was analyzed by iNOS immunolabeling, western-blot, and RT-PCR. NO production was determined by using DAR-4M AM, a reliable fluorescent indicator of subcellular NO production by iNOS. Embryonic, postnatal, and adult in situ quail retinas were used to analyze the pattern of iNOS expression in microglial cells during normal development. iNOS expression and NO production in LPS-treated microglial cells were investigated by an in vitro approach based on organotypic cultures of E8 retinas, in which microglial cell behavior is similar to that of the in situ retina, as previously demonstrated in our laboratory. We show here that amoeboid microglia in the quail retina express iNOS during normal development. This expression is stronger in microglial cells migrating tangentially in the vitreal part of the retina and is downregulated, albeit maintained, when microglia differentiate and become ramified. LPS treatment of retina explants also induces changes in the morphology of amoeboid microglia compatible with their activation, increasing their lysosomal compartment and upregulating iNOS expression with a concomitant production of NO. Taken together, our findings demonstrate that immature microglial cells express iNOS during normal development, suggesting a certain degree of activation. Furthermore, LPS treatment induces overactivation of amoeboid

  3. Exercise-induced cardioprotection: a role for eNOS uncoupling and NO metabolites.

    PubMed

    Farah, C; Kleindienst, A; Bolea, G; Meyer, G; Gayrard, S; Geny, B; Obert, P; Cazorla, O; Tanguy, S; Reboul, Cyril

    2013-11-01

    Exercise is an efficient strategy for myocardial protection against ischemia-reperfusion (IR) injury. Although endothelial nitric oxide synthase (eNOS) is phosphorylated and activated during exercise, its role in exercise-induced cardioprotection remains unknown. This study investigated whether modulation of eNOS activation during IR could participate in the exercise-induced cardioprotection against IR injury. Hearts isolated from sedentary or exercised rats (5 weeks training) were perfused with a Langendorff apparatus and IR performed in the presence or absence of NOS inhibitors [N-nitro-L-arginine methyl ester, L-NAME or N5-(1-iminoethyl)-L-ornithine, L-NIO] or tetrahydrobiopterin (BH₄). Exercise training protected hearts against IR injury and this effect was abolished by L-NAME or by L-NIO treatment, indicating that exercise-induced cardioprotection is eNOS dependent. However, a strong reduction of eNOS phosphorylation at Ser1177 (eNOS-PSer1177) and of eNOS coupling during early reperfusion was observed in hearts from exercised rats (which showed higher eNOS-PSer1177 and eNOS dimerization at baseline) in comparison to sedentary rats. Despite eNOS uncoupling, exercised hearts had more S-nitrosylated proteins after early reperfusion and also less nitro-oxidative stress, indexed by lower malondialdehyde content and protein nitrotyrosination compared to sedentary hearts. Moreover, in exercised hearts, stabilization of eNOS dimers by BH4 treatment increased nitro-oxidative stress and then abolished the exercise-induced cardioprotection, indicating that eNOS uncoupling during IR is required for exercise-induced myocardial cardioprotection. Based on these results, we hypothesize that in the hearts of exercised animals, eNOS uncoupling associated with the improved myocardial antioxidant capacity prevents excessive NO synthesis and limits the reaction between NO and O₂·- to form peroxynitrite (ONOO⁻), which is cytotoxic.

  4. Critical Incidents in the Development of Pedagogical Content Knowledge for Teaching the Nature of Science: A Prospective Elementary Teacher's Journey

    NASA Astrophysics Data System (ADS)

    Hanuscin, Deborah L.

    2013-10-01

    While teacher educators have had some success in helping prospective teachers understand the nature of science (NOS), they have been less effective in helping prospective teachers teach NOS. Though several studies have alluded to impacts of various interventions on developing pedagogical content knowledge (PCK) for NOS, the nature, source, and development of PCK for NOS has not yet been investigated in any systematic way. This study addresses that gap by identifying critical incidents in the development of PCK for NOS of a prospective elementary teacher as she transitions from her methods course to student teaching. Analysis of data collected over a 2-year period illuminates pedagogical dilemmas faced by the prospective teacher in enacting NOS instruction within a school culture of primarily “traditional” science teaching. Through construction of critical incident vignettes, narrative inquiry is employed to illustrate the changes in her PCK for NOS over time, and the experiences that facilitated these changes. Implications for supporting the development of PCK for NOS within teacher education are discussed.

  5. Nitric oxide synthase (NOS) in the Japanese fireflies Luciola lateralis and Luciola cruciata.

    PubMed

    Ohtsuki, Hajime; Yokoyama, Jun; Ohba, Nobuyoshi; Ohmiya, Yoshihiro; Kawata, Masakado

    2008-12-01

    Species-specific flash patterns in firefly species are important for the investigation of the evolution of Lampyridae. Since nitric oxide synthase (NOS) is one of the key enzymes controlling flash patterns, we determined the cDNA sequences of NOS in the Japanese fireflies Luciola lateralis and L. cruciata. The identity of the NOS sequences was very high between these 2 species. Firefly NOS also exhibited a high identity with those of other insect species, and the cofactor-binding domains were particularly well conserved. Many negatively selected sites were detected throughout the NOS sequences; however, no positive selection was detected. The phylogenetic relationship of insect NOS was different from that of the general classification system, although the lineages corresponded to the major recognized taxonomic groups.

  6. Methylene Blue Attenuates iNOS Induction Through Suppression of Transcriptional Factor Binding Amid iNOS mRNA Transcription.

    PubMed

    Huang, Chao; Tong, Lijuan; Lu, Xu; Wang, Jia; Yao, Wenjuan; Jiang, Bo; Zhang, Wei

    2015-08-01

    Inducible nitric oxide synthase (iNOS) critically contributes to the development of endotoxin-mediated inflammation. It can be induced by cytokines or endotoxins via distinct signaling pathways. Lipopolysaccharide (LPS) triggers iNOS expression through activation of the inhibitor of κB-α (IκB-α)-nuclear factor κB (NF-κB) cascade, whereas interferon-γ (IFN-γ) acts primarily through Janus kinase (JAK)-signal transducer and activator of transcription 1 (STAT1). Methylene blue (MB), an agent used clinically to treat numerous ailments, has been shown to reduce NO accumulation through suppression of iNOS activity. But it remains unclear whether MB affects iNOS induction. This knowledge gap is addressed in the present study using cultured cells and endotoxemic mice. With mouse macrophages, MB treatment prevented the LPS- and/or IFN-γ-stimulated iNOS protein expression. Real-time PCR experiments showed that iNOS mRNA transcription was robustly blocked by MB treatment. The inhibitory effect of MB on iNOS expression was confirmed in vivo in endotoxemic mice. Further analysis showed that MB had no significant effect on IκB-α degradation and NF-κB or STAT1 phosphorylation in LPS/IFN-γ-stimulated cells. The nuclear transport of active NF-κB or STAT1 was also not affected by MB treatment. But MB treatment markedly reduced the binding of NF-κB and STAT1 to their DNA elements. Chromatin immunoprecipitation assays confirmed that MB reduced NF-κB and STAT1 bindings to iNOS promoter inside the cell. These studies show that MB attenuates transcriptional factor binding amid iNOS mRNA transcription, providing further insight into the molecular mechanism of MB in disease therapy.

  7. Examining the Sources for Our Understandings about Science: Enduring Conflations and Critical Issues in Research on Nature of Science in Science Education

    ERIC Educational Resources Information Center

    Abd-El-Khalick, Fouad

    2012-01-01

    This position paper addresses some enduring, as well as emerging issues, associated with the crucial question of benchmarking understandings about nature of science (NOS) for precollege science education. The question of benchmarking NOS understandings is revisited in light of the often cited, continuing debates among historians, philosophers, and…

  8. Exploring Impacts of the EED 420 Science Methods Course on Pre-Service Elementary Teachers' Views Regarding the Nature of Science

    ERIC Educational Resources Information Center

    Bang, EunJin

    2013-01-01

    This study explores the impact of a semester-long science methods course examining pre-service elementary teachers' views on the nature of science (NOS). Also examined were NOS characteristics that pre-service teachers incorporated into their science lesson plans and peer teachings, during the course. Data used for this study were obtained from 21…

  9. The Analysis of the Changes in Integration of Nature of Science into Turkish High School Chemistry Textbooks: Is There Any Development?

    ERIC Educational Resources Information Center

    Aydin, Sevgi; Tortumlu, Selma

    2015-01-01

    To attain the goal of scientific literacy, the nature of science (NOS) is one of the areas that should be addressed. In many countries, the training of scientifically literate generations is a fundamental aim of science education, as a result there is an emphasis on NOS in science curricula and curricular materials. Textbooks prepared to teach…

  10. 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…

  11. 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.

  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. 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…

  14. Conceptions of the Nature of Science--Are They General or Context Specific?

    ERIC Educational Resources Information Center

    Urhahne, Detlef; Kremer, Kerstin; Mayer, Juergen

    2011-01-01

    The study investigates the relationship between general and context-specific conceptions of the nature of science (NOS). The categorization scheme by Osborne et al. (J Res Sci Teach 40:692-720, "2003") served as the theoretical framework of the study. In the category "nature of scientific knowledge", the certainty, development, simplicity,…

  15. 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…

  16. 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;…

  17. [Genetics of the neuronal NO synthase (NOS1) in the etiology of bronchial asthma].

    PubMed

    Grasemann, H

    2001-08-01

    The free radical nitric oxide (NO) is endogenously produced by enzymes known as NO synthases. NO in the airways is involved in a number of pathophysiological processes, such as airway inflammation, allergic reactions, and asthma. Asthma is a multifactorial disease that is caused by environmental and genetic factors. Genome wide screening approaches in families revealed evidence for linkage between chromosomal region 12q and allergic diseases, increased serum IgE levels as well as the development of asthma. The gene encoding for neuronal NOS (NOS1) is an attractive candidate gene for asthma, not only because it is localized in chromosomal region 12q24. Experimental studies in animals and humans suggest that NOS1 plays an important role in asthma. For instance, in a murine model of allergic asthma, NOS1 has been shown to be important for the development of bronchial hyperresponsiveness, since mice deficient for the nos1 gene were less responsive to airway challenge than both wild-type mice and mice deficient for the nos2 gene. Case-control studies in humans revealed allelic associations between polymorphic markers in the NOS1 gene and the diagnosis of asthma. Furthermore, increased concentrations of NO in the airways of asthmatics are closely related to the size of an intronic (AAT)(n)-repeat polymorphism in the NOS1 gene. The purpose of this review is to summarize studies that provide evidence for an involvement of NOS1 in the genetics of asthma.

  18. Inhibition of Rho protein stimulates iNOS expression in rat vascular smooth muscle cells.

    PubMed

    Muniyappa, R; Xu, R; Ram, J L; Sowers, J R

    2000-06-01

    Inducible nitric oxide synthase (iNOS) in vascular smooth muscle cells (VSMCs) is upregulated in arterial injury and plays a role in regulating VSMC proliferation and restenosis. Inflammatory cytokines [e.g., interleukin-1beta (IL-1beta)] released during vascular injury induce iNOS. Small GTP-binding proteins of the Ras superfamily play a major role in IL-1beta-dependent signaling pathways. In this study, we examined the role of Rho GTPases in regulating iNOS expression in VSMCs. Treatment of VSMCs with mevastatin, which inhibits isoprenylation of Rho and other small GTP-binding proteins, produced significantly higher amounts of IL-1beta-evoked NO and iNOS protein compared with control. Similarly, bacterial toxins [Toxin B from Clostridium difficile and C3 ADP-ribosyl transferase (C3) toxin from Clostridium botulinium] that specifically inactivate Rho proteins increased NOS products (NO and citrulline) and iNOS expression. Toxin B increased the activity of iNOS promoter-reporter construct in VSMCs. Both toxins enhanced IL-1beta-stimulated iNOS expression and NO production. These data demonstrate for the first time that inhibition of Rho induces iNOS and suggest a role for Rho protein in IL-1beta-stimulated NO production in VSMCs.

  19. Evaluation of a multi-functional nanocarrier for targeted breast cancer iNOS gene therapy.

    PubMed

    McCarthy, Helen O; Zholobenko, Alek V; Wang, Yuhua; Canine, Brenda; Robson, Tracy; Hirst, David G; Hatefi, Arash

    2011-02-28

    The present study determines whether the novel designer biomimetic vector (DBV) can condense and deliver the cytotoxic iNOS gene to breast cancer cells to achieve a therapeutic effect. We have previously shown the benefits of iNOS for cancer gene therapy but the stumbling block to future development has been the delivery system. The DBV was expressed, purified and complexed with the iNOS gene. The particle size and charge were determined via dynamic light scattering techniques. The toxicity of the DBV/iNOS nanoparticles was quantified using the cell toxicity and clonogenic assays. Over expression of iNOS was confirmed via Western blotting and Griess test. The DBV delivery system fully condensed the iNOS gene with nanoparticles less than 100nm. Transfection with the DBV/iNOS nanoparticles resulted in a maximum of 62% cell killing and less than 20% clonogenicity. INOS overexpression was confirmed and total nitrite levels were in the range of 18μM. We report for the first time that the DBV can successfully deliver iNOS and achieve a therapeutic effect. There is significant cytotoxicity coupled with evidence of a bystander effect. We conclude that the success of the DBV fusion protein in the delivery of iNOS in vitro is worthy of future in vivo experiments.

  20. PEX7 and EBP50 Target iNOS to the Peroxisome in Hepatocytes

    PubMed Central

    Loughran, Patricia A.; Stolz, Donna B.; Barrick, Stacey R.; Wheeler, David S.; Friedman, Peter A.; Rachubinski, Richard A.; Watkins, Simon C.; Billiar, Timothy R.

    2013-01-01

    iNOS localizes to both the cytosol and peroxisomes in hepatocytes in vitro and in vivo. The structural determinants for iNOS localization are not known. One plausible mechanism for iNOS localization to the peroxisome is through the interaction with peroxisomal import proteins PEX5 or PEX7. siRNA knockdown of PEX7 reduced iNOS colocalization with the peroxisomal protein PMP70. Proteomic studies using MALDI-MS identified iNOS association with the 50-kD ezrin binding PDZ protein (EBP50). Confocal microscopy studies and immunoelectron microscopy confirmed iNOS association with EBP50, with greatest colocalization occurring at 8 hours of cytokine exposure. EBP50 associated with peroxisomes in a PEX5 and PEX7-dependent manner. iNOS localization to peroxisomes was contingent on EBP50 expression in LPS-treated mice. Thus, iNOS targeting to peroxisomes in hepatocytes involves interaction with PEX7 and EBP50. The targeting of iNOS protein to the peroxisome may shift the balance of metabolic processes that rely on heme proteins susceptible to modification by radical oxygen and nitrogen radicals. PMID:23474170

  1. Natural inflation

    SciTech Connect

    Frieman, J.A.

    1991-02-01

    A pseduo-Nambu-Goldstone boson, with a potential of the form V({phi}) = {Lambda}{sup 4}(1 {plus minus} cos({phi}/f)), can naturally give rise to an epoch of inflation in the early universe. Successful inflation can be achieved if f {approximately} m{sub pl} and {Lambda} {approximately} m{sub GUT}. Such mass scales arise in particle physics models with a gauge group that becomes strongly interacting a the GUT scale, e.g., as is expected to happen in the hidden sector of superstring theories. The density fluctuation spectrum is a non-scale-invariant power law, with extra power on large scales. 12 refs., 3 figs.

  2. Natural Strain

    NASA Technical Reports Server (NTRS)

    Freed, Alan D.

    1995-01-01

    The purpose of this paper is to present a consistent and thorough development of the strain and strain-rate measures affiliated with Hencky. Natural measures for strain and strain-rate, as I refer to them, are first expressed in terms of of the fundamental body-metric tensors of Lodge. These strain and strain-rate measures are mixed tensor fields. They are mapped from the body to space in both the Eulerian and Lagrangian configurations, and then transformed from general to Cartesian fields. There they are compared with the various strain and strain-rate measures found in the literature. A simple Cartesian description for Hencky strain-rate in the Lagrangian state is obtained.

  3. Natural relaxation

    NASA Astrophysics Data System (ADS)

    Marzola, Luca; Raidal, Martti

    2016-11-01

    Motivated by natural inflation, we propose a relaxation mechanism consistent with inflationary cosmology that explains the hierarchy between the electroweak scale and Planck scale. This scenario is based on a selection mechanism that identifies the low-scale dynamics as the one that is screened from UV physics. The scenario also predicts the near-criticality and metastability of the Standard Model (SM) vacuum state, explaining the Higgs boson mass observed at the Large Hadron Collider (LHC). Once Majorana right-handed neutrinos are introduced to provide a viable reheating channel, our framework yields a corresponding mass scale that allows for the seesaw mechanism as well as for standard thermal leptogenesis. We argue that considering singlet scalar dark matter extensions of the proposed scenario could solve the vacuum stability problem and discuss how the cosmological constant problem is possibly addressed.

  4. 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

    2016-12-01

    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.

  5. Depletion of arginine by recombinant arginine deiminase induces nNOS-activated neurotoxicity in neuroblastoma cells.

    PubMed

    Lin, Shan-Erh; Wu, Fe-Lin Lin; Wei, Ming-Feng; Shen, Li-Jiuan

    2014-01-01

    The abnormal regulation of inducible nitric oxide synthase (iNOS) and neuronal nitric oxide synthase (nNOS) is associated with neurodegenerative disorders. Recombinant arginine deiminase (rADI) is a selective NO modulator of iNOS and eNOS in endothelial cells, and it also exhibits neuroprotective activity in an iNOS-induced neuron-microglia coculture system. However, the effect of rADI on nNOS remains unknown. Addressing this issue is important for evaluating the potential application of rADI in neurodegenerative diseases. SH-SY5Y cells were treated with N-methyl-D-aspartic acid (NMDA) to activate nNOS. NMDA increased NO production by 39.7 ± 3.9% via nNOS under arginine-containing conditions, but there was no significant increase in both arginine-free and rADI pretreated arginine-containing (citrulline) buffer. Subsequently, neither NMDA nor rADI alone caused cytotoxicity, whereas cotreatment with NMDA and rADI resulted in dissipation of the cell mitochondrial membrane potential and decreased cell viability. The mechanism of rADI cytotoxicity in the presence of NMDA is caused by the inhibition of NO production via nNOS mediated by the NMDA receptor, which was abolished when extracellular arginine was absent, even in the presence of citrulline. rADI not only reduced NO production but also caused cellular toxicity in nNOS-activated SH-SY5Y cells, suggesting a dual role for rADI in NOS-mediated neurotoxicity.

  6. Differential NOS expression in freshwater and aestivating Protopterus dolloi (lungfish): heart vs kidney readjustments.

    PubMed

    Amelio, Daniela; Garofalo, Filippo; Brunelli, Elvira; Loong, Ai May; Wong, Wai Peng; Ip, Yuen Kwong; Tota, Bruno; Cerra, Maria Carmela

    2008-02-01

    African lungfish Protopterus dolloi is an obligatory air-breather, which aestivates in a cocoon during the dry season. Aestivation associates with functional modifications in many tissues and organs, including heart and kidney. Due to its pleiotropic modulatory effects, nitric oxide (NO), generated by nitric oxide synthases (NOSs), may coordinate organ rearrangement, allowing adaptive adjustments under stressful environmental conditions. By immunofluorescence, Western blotting and NADPH-diaphorase, we examined cardiac and renal localization and activity of NOSs isoforms in both freshwater (FW) and aestivating [6 days (6DA) and 40 days (40DA) of estivation] P. dolloi. In heart and kidney endothelial NOS (eNOS) is the major isoform with respect to inducible and neuronal NOS (iNOS and nNOS, respectively). Cardiac eNOS locates in the epicardium, the trabecular endothelial endocardium, and myocardiocytes of both FW and aestivating fish. Western blotting revealed that cardiac eNOS expression increases in 6DA, but decreases in 40DA fish. In FW fish kidney eNOS is present in vascular endothelial cells and in podocytes of renal corpuscles. In tubular epithelial cells it is restricted to the apical pole. With aestivation, both renal localization and expression of eNOS increase. NADPH-diaphorase revealed an enhancement of cardiac and renal NOS activities during aestivation. Results suggest that in P. dolloi NO contributes, in an autocrine-paracrine fashion, to cardiac and renal readjustments during aestivation. Our findings are of evolutionary interest, since they document for the first time the presence of a NOS system in a ancestral fish, indicative of deep phylogenetic roots of NO bio-synthesis.

  7. Diesel Particulate Exposed Macrophages Alter Endothelial Cell Expression of eNOS, iNOS, MCP1, and Glutathione Synthesis Genes

    PubMed Central

    Weldy, Chad S.; Wilkerson, Hui-Wen; Larson, Timothy V.; Stewart, James A.; Kavanagh, Terrance J.

    2011-01-01

    There is considerable debate regarding inhaled diesel exhaust particulate (DEP) causing impairments in vascular reactivity. Although there is evidence that inhaled particles can translocate from the lung into the systemic circulation, it has been suggested that inflammatory factors produced in the lung following macrophage particle engulfment also pass into the circulation. To investigate these differing hypotheses, we used in vitro systems to model each exposure. By using a direct exposure system and a macrophage-endothelial cell co-culture model, we compared the effects of direct DEP exposure and exposure to inflammatory factors produced by DEP-treated macrophages, on endothelial cell mRNA levels for eNOS, iNOS, endothelin-1, and endothelin-converting-enzyme-1. As markers of oxidative stress, we measured the effects of DEP treatment on glutathione (GSH) synthesis genes and on total GSH. In addition, we analyzed the effect of DEP treatment on monocyte chemo-attractant protein-1. Direct DEP exposure increased endothelial GCLC and GCLM as well as total GSH in addition to increased eNOS, iNOS and Mcp1 mRNA. Alternatively, inflammatory factors released from DEP-exposed macrophages markedly up-regulated endothelial iNOS and Mcp1 while modestly down-regulating eNOS. These data support both direct exposure to DEP and the release of inflammatory cytokines as explanations for DEP-induced impairments in vascular reactivity. PMID:21920430

  8. 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.

  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. 76 FR 24062 - Florida Power and Light Company, St. Lucie, Unit Nos. 1 and 2; Exemption

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-29

    ... COMMISSION Florida Power and Light Company, St. Lucie, Unit Nos. 1 and 2; Exemption 1.0 Background Florida Power & Light Company, et al. (FPL, the licensee), is the holder of Facility Operating License Nos. DPR... Commission hereby grants Florida Power & Light Company an exemption from the requirements of 10 CFR...

  11. The RNA binding protein TIAR is involved in the regulation of human iNOS expression.

    PubMed

    Fechir, M; Linker, K; Pautz, A; Hubrich, T; Kleinert, H

    2005-09-05

    Human inducible NO synthase (iNOS) expression is regulated by post-transcriptional mechanisms. The 3'-untranslated region (3'-UTR) of the human iNOS mRNA contains AU-rich elements (ARE), which are known to be important for the regulation of mRNA stability. The 3'-UTR of the human iNOS mRNA has been shown to regulate human iNOS mRNA expression post-transcriptionally. One RNA-binding protein known to interact with AREs and to regulate mRNA stability is the T cell intracellular antigen-1-related protein (TIAR). In RNA binding studies TIAR displayed high affinity binding to the human iNOS 3'-UTR sequence. In RNase protection experiments, the cytokine incubation needed for iNOS expression did not change TIAR expression in DLD-1 cells. However, overexpression of TIAR in human DLD-1 colon carcinoma cells resulted in enhanced cytokine-induced iNOS expression. In conclusion, TIAR seems to be involved in the post-transcriptional regulation of human iNOS expression.

  12. 48 CFR Appendix to Part 6101 - Form Nos. 1-5

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 7 2010-10-01 2010-10-01 false Form Nos. 1-5 Appendix to Part 6101 Federal Acquisition Regulations System CIVILIAN BOARD OF CONTRACT APPEALS, GENERAL SERVICES ADMINISTRATION CONTRACT DISPUTE CASES Pt. 6101, App. Appendix to Part 6101—Form Nos. 1-5 Form 1, GSA Form...

  13. Inducible nitric oxide synthase (NOS II) is constitutive in human neutrophils.

    PubMed

    Cedergren, Jan; Follin, Per; Forslund, Tony; Lindmark, Maria; Sundqvist, Tommy; Skogh, Thomas

    2003-10-01

    The objective was to study the expression of inducible nitric oxide synthase (NOS II) in and NO production by human blood neutrophils and in in vivo exudated neutrophils. Cellular expression of NOS II was evaluated by flow cytometry in whole blood, in isolated blood neutrophils, and in neutrophils obtained by exudation in vivo into skin chambers. Neutrophil NOS II was also demonstrated by Western blotting. Uptake of 3H-labelled L-arginine was studied in vitro and NOS activity measured in a whole cell assay by the conversion of 3H-arginine to 3H-citrulline. In contrast to unseparated blood cells, NOS II was demonstrable both in isolated blood neutrophils and exudated cells. The failure to detect NOS II by flow cytometry in whole blood cells thus proved to be due to the quenching effect of hemoglobin. Western blotting revealed a 130 kD band corresponding to NOS II in isolated blood neutrophils, but detection was dependent on diisopropylfluorophosphate for proteinase inhibition. L-arginine was taken up by neutrophils, but enzymatic activity could not be demonstrated. We conclude that human neutrophils constitutively express NOS II, but that its demonstration by FITC-labelling is inhibited by hemoglobin-mediated quenching in whole blood samples.

  14. 77 FR 12010 - Marine Mammals; File Nos. 1076-1789 and 14502

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-28

    ... National Oceanic and Atmospheric Administration RIN 0648-XB040 Marine Mammals; File Nos. 1076-1789 and... to Scientific Research Permit Nos. 1076-1789 and 14502. ADDRESSES: The amendment and related... importing of marine mammals (50 CFR part 216). Permit No. 1076-1789: This permit, issued on March 13,...

  15. NOS3 polymorphisms, cigarette smoking, and cardiovascular disease risk: The Atherosclerosis Risk in Communities study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Endothelial nitric oxide synthase (NOS3) activity and cigarette smoking significantly influence endothelial function. We sought to determine whether cigarette smoking modified the association between NOS3 polymorphisms and risk of coronary heart disease or stroke. All 1085 incident coronary heart di...

  16. 49 CFR 173.335 - Chemical under pressure n.o.s.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 2 2013-10-01 2013-10-01 false Chemical under pressure n.o.s. 173.335 Section 173... REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS Gases; Preparation and Packaging § 173.335 Chemical under pressure n.o.s. (a) General requirements. A cylinder filled with a chemical under pressure must be offered...

  17. Explicit Teaching of the Nature of Science: A Study of the Impact of Two Variations of Explicit Instruction on Student Learning

    NASA Astrophysics Data System (ADS)

    Melville, Melissa

    The nature of science (NOS) is included in the National Science Education Standards and is described as a critical component in the development of scientifically literate students. Despite the significance of NOS in science education reform, research shows that many students continue to possess naive views of NOS. Explicit and reflective discussion as an instructional approach is relatively new in the field of research in NOS. When compared to other approaches, explicit instruction has been identified as more effective in promoting informed views of NOS, but gaps in student understanding still exist. The purpose of this study was to deepen the understanding of student learning of NOS through the investigation of two variations of explicit instruction. The subjects of the study were two seventh grade classes taught by the same classroom teacher. One class received explicit instruction of NOS within a plate tectonics unit and the second class received explicit instruction of NOS within a plate tectonics unit plus supporting activities focused on specific aspects of NOS. The instruction time for both classes was equalized and took place over a three week time period. The intention of this study was to see if the additional NOS activities helped students build a deeper understanding of NOS, or if a deep understanding could be formed solely through explicit and reflective discussion within content instruction. The results of the study showed that both classes progressed in their understanding of NOS. When the results of the two groups were compared, the group with the additional activities showed statistically significant gains on two of the four aspects of NOS assessed. These results suggest that the activities may have been valuable in promoting informed views, but more research is needed in this area.

  18. Factors affecting early elementary (K--4) teachers' introduction of the nature of science: A national survey

    NASA Astrophysics Data System (ADS)

    Sweeney, Sophia Jean

    A researcher-developed questionnaire regarding the importance and developmental appropriateness of 12 specific elements of the nature of science (Alshamrani, 2008) for early elementary (kindergarten through fourth grade [K-4]) science instruction was mailed to a random sample of U.S. K-4 teachers. At least half (N = 377) of the respondents reported introducing the inferential, empirical, creative, collaborative, tentative, and cultural aspects of the nature of science (NOS) during the current school year, as well as the idea that no single step-by-step scientific method exists. Over 90% of respondents identified the inferential, empirical, and creative aspects of the NOS as developmentally appropriate for the grade level taught. Based on a 5 point scale (0=not at all important and 4 =very important), the mean scores of eight NOS elements were above a value of three, which corresponded with the descriptor somewhat important to include in K-4 science instruction: the inferential, empirical, creative, collaborative, cultural, and tentative NOS, along with the ideas that replication is an important aspect of experimental research and that no single stepwise scientific method exists. A series of binary logistic regression analyses were used to explore the impact of three predictor variables (developmental appropriateness, importance, and presence in state standards) on teachers' self-reported introduction of each of the NOS elements during the 2009-2010 school year. The data for the presence of the NOS elements in state standards were extracted from a previous study (McComas, Lee, & Sweeney, 2009). Developmental appropriateness was a significant predictor of teachers' introduction of the NOS element for all except the collaborative, empirical and inferential aspects of NOS. Importance was a significant predictor for all 12 NOS elements of interest. A NOS element's presence in the state standards significantly predicted teachers' introduction of that NOS element for only

  19. NASA Operational Simulator (NOS) for V&V of complex systems

    NASA Astrophysics Data System (ADS)

    Zemerick, Scott A.; Morris, Justin R.; Bailey, Brandon T.

    2013-05-01

    This paper describes the development, capabilities and utility of the NASA Operational Simulator (NOS), a generic software-only simulation architecture developed for NASA missions. NOS was developed by the NASA's Independent Verification and Validation (IV&V) Independent Test Capability (ITC) team and is primarily utilized by software developers and (independent) testers to verify the functionality of a spacecraft's flight software from a system-wide perspective. NOS was initially developed in support of a software-only simulator for the Global Precipitation Measurement (GPM) mission to support verification and validation activities for NASA's IV&V Program. Due to the successes of the GPM simulator (GO-SIM), the NOS architecture is being reused to develop a simulation environment in support of the James Webb Space Telescope (JWST). While NOS has primarily been utilized on NASA missions, its generic architecture can be easily applied across domains to support V&V of complex systems.

  20. 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.

  1. Outcomes of nature of science instruction along a context continuum: preservice secondary science teachers' conceptions and instructional intentions

    NASA Astrophysics Data System (ADS)

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

    2016-02-01

    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 teacher cohorts (n = 70) enrolled in a two-year Master of Teaching program. Participants were explicitly taught current NOS conceptions using activities that incorporated varied degrees of contextualization and were informed by conceptual change principles during the first program year. Participants' pre- and post-instruction conceptions were assessed using VNOS-C questionnaire written responses and follow-up interviews. Participants' views were classified by degree of alignment (non, partially, or fully aligned) with current NOS conceptions. Interview transcripts were analyzed using analytic induction to verify/refine VNOS responses and to identify patterns in NOS instructional plans and rationales. Wilcoxon signed ranks tests were run to assess possible statistical significance of pre- to post-instruction changes. Participants' responses shifted markedly toward more aligned NOS conceptions post-instruction, with substantial and statistically significant gains for each assessed tenet (all p-values <.001). All participants planned future NOS instruction and most expressed a sophisticated rationale for this choice, including that NOS supported the teaching of key concepts such as evolution. These results indicate that teaching and scaffolding NOS lessons along a context continuum can be effective in eliciting desired changes in preservice teachers' NOS conceptions and instructional intentions within the confines of the science methods course. Future research will examine post-methods course and post-program NOS instruction.

  2. ChAT and NOS in human myenteric neurons: co-existence and co-absence.

    PubMed

    Beck, Martin; Schlabrakowski, Anne; Schrödl, Falk; Neuhuber, Winfried; Brehmer, Axel

    2009-10-01

    Most myenteric neurons contain one of the two generating enzymes for major excitatory and inhibitory neurotransmitters: choline acetyltransferase (ChAT) or neuronal nitric oxide synthase (NOS). Two minor groups of myenteric neurons contain either both enzymes or neither. Our study had two aims: (1) to compare the proportions of neurons stained for ChAT and/or NOS in human small and large intestinal whole-mounts by co-staining with an antibody against the human neuronal protein Hu C/D (HU); (2) to characterize these neurons morphologically by co-staining with a neurofilament (NF) antibody. In small intestinal whole-mounts co-stained with HU, we counted more ChAT-positive (ChAT+) than NOS+ neurons (52% vs. 38%), whereas the large intestine exhibited fewer ChAT+ than NOS+ neurons (38% vs. 50%). Neurons co-reactive for both ChAT and NOS accounted for about 3% in both regions, whereas neurons negative for both enzymes accounted for 7% in the small intestine and 8% in the large intestine. Co-staining with NF revealed that, in both small and large intestine, ChAT+/NOS+ neurons were either spiny (type I) neurons or displayed smaller perikarya that were weakly or not NF-stained. Of all spiny neurons, almost one third was co-reactive for ChAT and NOS, whereas nearly two thirds were positive only for NOS. Neurons negative for both ChAT and NOS were heterogeneous in size and NF reactivity. Thus, neither the co-existence nor the co-absence of ChAT and NOS in human myenteric neurons is indicative for particular neuron types, with several qualitative and quantitative parameters showing a wide range of interindividual variability.

  3. 3-Methylcholanthrene/Aryl-Hydrocarbon Receptor-Mediated Hypertension Through eNOS Inactivation.

    PubMed

    Chang, Chih-Cheng; Hsu, Yung-Ho; Chou, Hsiu-Chu; Lee, Yuan-Chii G; Juan, Shu-Hui

    2017-05-01

    Endothelial nitric oxide synthase (eNOS) modulates vascular blood pressure and is predominantly expressed in endothelial cells and activated through the protein kinase B (Akt/PKB)-dependent pathway. We previously reported that 3-methylcholanthrene (3MC) activates the aryl hydrocarbon receptor (AhR) and reduces PI3K/Akt phosphorylation. This study investigated the mechanism underlying the downregulatory effects of 3-MC on nitric oxide (NO) production occurring through the AhR/RhoA/Akt-mediated mechanism. The mechanism underlying the effects of 3-MC on eNOS activity and blood pressure was examined in vitro and in vivo through genetic and pharmacological approaches. Results indicated that 3-MC modified heat shock protein 90 (HSP90), caveolin-1, dynein, and eNOS mRNA and protein expression through the AhR/RhoA-dependent mechanism in mouse cerebral vascular endothelial cells (MCVECs) and that 3-MC reduced eNOS phosphorylation through the AhR/RhoA-mediated inactivation of Akt1. The upregulation of dynein expression was associated with decreased eNOS dimer formation (eNOS dimer; an activated form of the enzyme). Coimmunoprecipitation assay results indicated that 3-MC significantly reduced the interaction between eNOS and its regulatory proteins, including Akt1 and HSP90, but increased the interaction between eNOS and caveolin-1. Immunofluorescence and Western blot analysis revealed that 3-MC reduced the amount of membrane-bound activated eNOS, and a modified Griess assay revealed that 3-MC concomitantly reduced NO production. However, simvastatin reduced 3-MC-mediated murine hypertension. Our study results indicate that AhR, RhoA, and eNOS have major roles in blood pressure regulation. Statin intervention might provide a potential therapeutic approach for reducing hypertension caused by 3-MC. J. Cell. Physiol. 232: 1020-1029, 2017. © 2016 Wiley Periodicals, Inc.

  4. PERSPECTIVE VIEW, CORNER UNIT AND REPRESENTATIVE INTERIOR HOUSE (NOS. 1921 ...

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

    PERSPECTIVE VIEW, CORNER UNIT AND REPRESENTATIVE INTERIOR HOUSE (NOS. 1921 AND 1923). THE TWO ATTACHED STRUCTURES WERE ONCE PART OF AN EIGHT-UNIT ROW EXTENDING FOR ONE-HALF A BLOCK ON THE NORTH SIDE OF DIAMOND STREET WEST FROM NINETEENTH STREET. THIS DEVELOPMENT LIKELY ALSO INCLUDED FOUR DWELLINGS IMMEDIATELY BEHIND THESE HOUSES TO THE NORTH, FRONTING ON NINETEENTH STREET. A NOTICE FROM THE MAY 28, 1890 ISSUE OF PHILADELPHIA REAL ESTATE RECORD AND BUILDERS’ GUIDE ANNOUNCED THE DEVELOPMENT’S ANTICIPATED CONSTRUCTION BY PROLIFIC LOCAL REAL ESTATE AGENT/BUILDER THOMAS H. PARKS, WHO LIVED ONLY ONE BLOCK AWAY AT THE CORNER OF GRATZ AND DIAMOND STREETS (IN NO. 1821, NOW LOST). THOMAS PARKS HAD USED ARCHITECT ANGUS S. WADE FOR THE 1800 BLOCK OF DIAMOND STREET, BUT IT APPEARS THAT HE MAY HAVE EMPLOYED ANOTHER OF POPULAR ARCHITECT WILLIS G. HALE’S PROTÉGÉS, ROBERT W. MARPLE, FOR THIS BLOCK, AT LEAST FOR THE SUPERINTENDENCE OF ITS CONSTRUCTION. THE HOUSES’ EBULLIENCE AND EXOTICISM SUGGESTS HALE’S WORK OR THAT OF HISO FFICE; THEY BEAR NOTABLE SIMILARITY TO HOUSES DESIGNED BY HALE A YEAR EARLIER IN THE 1800 BLOCK OF W. GIRARD AVENUE. SEE HABS PA-6677 FOR MORE ON THOMAS PARKS AND THE 1800 BLOCK OF DIAMOND STREET, AND HABS PA-6678, FOR ADDITIONAL INFORMATION ABOUT WILLIS HALE AND THE 1800 BLOCK OF W. GIRARD AVENUE. - 1900 Block Diamond Street (Houses), Northwest corner of Diamond & Uber Streets, Philadelphia, Philadelphia County, PA

  5. NASA Operational Simulator for Small Satellites (NOS3)

    NASA Technical Reports Server (NTRS)

    Zemerick, Scott

    2015-01-01

    The Simulation-to-Flight 1 (STF-1) CubeSat mission aims to demonstrate how legacy simulation technologies may be adapted for flexible and effective use on missions using the CubeSat platform. These technologies, named NASA Operational Simulator (NOS), have demonstrated significant value on several missions such as James Webb Space Telescope, Global Precipitation Measurement, Juno, and Deep Space Climate Observatory in the areas of software development, mission operationstraining, verification and validation (VV), test procedure development and software systems check-out. STF-1 will demonstrate a highly portable simulation and test platform that allows seamless transition of mission development artifacts to flight products. This environment will decrease development time of future CubeSat missions by lessening the dependency on hardware resources. In addition, through a partnership between NASA GSFC, the West Virginia Space Grant Consortium and West Virginia University, the STF-1 CubeSat will hosts payloads for three secondary objectives that aim to advance engineering and physical-science research in the areas of navigation systems of small satellites, provide useful data for understanding magnetosphere-ionosphere coupling and space weather, and verify the performance and durability of III-V Nitride-based materials.

  6. Correlated NOS-Imu and myf5 expression by satellite cells in mdx mouse muscle regeneration during NOS manipulation and deflazacort treatment.

    PubMed

    Anderson, Judy E; Vargas, Cinthya

    2003-06-01

    Satellite cells, muscle precursor cells in skeletal muscle, are normally quiescent and become activated by disease or injury. A lack of dystrophin and changes in the expression or activity of neuronal nitric oxide synthase (NOS-I) affect the timing of activation in vivo. Nitric oxide synthase inhibition delays muscle repair in normal mice, and worsens muscular dystrophy in the mdx mouse, a genetic homologue of Duchenne muscular dystrophy. However, the potential role of activation and repair events mediated by nitric oxide in determining the outcome of steroid or other treatments for muscular dystrophy is not clear. We tested the hypothesis that the extent of repair in dystrophic muscles of mdx mice is partly dependent on NOS-Imu expression and activity. Myotube formation in regenerating muscle was promoted by deflazacort treatment of mdx dystrophic mice (P<0.05), and improved by combination with the nitric oxide synthase substrate, L-arginine, especially in the diaphragm. NOS-Imu mRNA expression and activity were present in satellite cells and very new myotubes of regenerating and dystrophic muscle. Deflazacort treatment resulted in increased NOS-Imu expression in regenerating muscles in a strong and specific correlation with myf5 expression (r=0.95, P<0.01), a marker for muscle repair. Nitric oxide synthase inhibition prevented the deflazacort-induced rise in NOS-Imu and myf5 expression in the diaphragm without affecting the diameter of non-regenerating fibres. These in vivo studies suggest that gains in NOS-Imu expression and nitric oxide synthase activity in satellite cells can increase the extent and speed of repair, even in the absence of dystrophin in muscle fibres. NOS-Imu may be a useful therapeutic target to augment the effects of steroidal or other treatments of muscular dystrophy.

  7. 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.

  8. Synthesis and biological evaluation of 4,5-dihydro-1H-pyrazole derivatives as potential nNOS/iNOS selective inhibitors. Part 2: Influence of diverse substituents in both the phenyl moiety and the acyl group.

    PubMed

    Carrión, M Dora; Chayah, Mariem; Entrena, Antonio; López, Ana; Gallo, Miguel A; Acuña-Castroviejo, Darío; Camacho, M Encarnación

    2013-07-15

    In a preliminary article, we reported a series of 4,5-dihydro-1H-pyrazole derivatives as neuronal nitric oxide synthase (nNOS) inhibitors. Here we present the data about the inhibition of inducible nitric oxide synthase (iNOS) of these compounds. In general, we can confirm that these pyrazoles are nNOS selective inhibitors. In addition, taking these compounds as a reference, we have designed and synthesized a series of new derivatives by modification of the heterocycle in 1-position, and by introduction of electron-donating or electron-withdrawing substituents in the aromatic ring. These derivatives have been evaluated as nNOS and iNOS inhibitors in order to identify new compounds with improved activity and selectivity. Compound 3r, with three methoxy electron-donating groups in the phenyl moiety, is the most potent nNOS inhibitor, showing good selectivity nNOS/iNOS.

  9. 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.

    2016-02-01

    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.

  10. Obesity, Inflammation, and Exercise Training: Relative Contribution of iNOS and eNOS in the Modulation of Vascular Function in the Mouse Aorta

    PubMed Central

    Silva, Josiane F.; Correa, Izabella C.; Diniz, Thiago F.; Lima, Paulo M.; Santos, Roger L.; Cortes, Steyner F.; Coimbra, Cândido C.; Lemos, Virginia S.

    2016-01-01

    Background: The understanding of obsesity-related vascular dysfunction remains controversial mainly because of the diseases associated with vascular injury. Exercise training is known to prevent vascular dysfunction. Using an obesity model without comorbidities, we aimed at investigating the underlying mechanism of vascular dysfunction and how exercise interferes with this process. Methods: High-sugar diet was used to induce obesity in mice. Exercise training was performed 5 days/week. Body weight, energy intake, and adipose tissues were assessed; blood metabolic and hormonal parameters were determined; and serum TNFα was measured. Blood pressure and heart rate were assessed by plethysmography. Changes in aortic isometric tension were recorded on myograph. Western blot was used to analyze protein expression. Nitric oxide (NO) was evaluated using fluorescence microscopy. Antisense oligodeoxynucleotides were used for inducible nitric oxide synthase isoform (iNOS) knockdown. Results: Body weight, fat mass, total cholesterol, low-density lipoprotein cholesterol fraction, insulin, and leptin were higher in the sedentary obese group (SD) than in the sedentary control animals (SS). Exercise training prevented these changes. No difference in glucose tolerance, insulin sensitivity, blood pressure, and heart rate was found. Decreased vascular relaxation and reduced endothelial nitric oxide synthase (eNOS) functioning in the SD group were prevented by exercise. Contractile response to phenylephrine was decreased in the aortas of the wild SD mice, compared with that of the SS group; however, no alteration was noted in the SD iNOS−/− animals. The decreased contractility was endothelium-dependent, and was reverted by iNOS inhibition or iNOS silencing. The aortas from the SD group showed increased basal NO production, serum TNFα, TNF receptor-1, and phospho-IκB. Exercise training attenuated iNOS-dependent reduction in contractile response in high-sugar diet–fed animals

  11. 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

  12. Molecular and biochemical characterization of dNOS: a Drosophila Ca2+/calmodulin-dependent nitric oxide synthase.

    PubMed Central

    Regulski, M; Tully, T

    1995-01-01

    Nitric oxide (NO) is an intercellular messenger involved with various aspects of mammalian physiology ranging from vasodilation and macrophage cytotoxicity to neuronal transmission. NO is synthesized from L-arginine by NO synthase (NOS). Here, we report the cloning of a Drosophila NOS gene, dNOS, located at cytological position 32B. The dNOS cDNA encodes a protein of 152 kDa, with 43% amino acid sequence identity to rat neuronal NOS. Like mammalian NOSs, DNOS protein contains putative binding sites for calmodulin, FMN, FAD, and NADPH. DNOS activity is Ca2+/calmodulin dependent when expressed in cell culture. An alternative RNA splicing pattern also exists for dNOS, which is identical to that for vertebrate neuronal NOS. These structural and functional observations demonstrate remarkable conservation of NOS between vertebrates and invertebrates. Images Fig. 2 Fig. 3 PMID:7568075

  13. 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.

  14. 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.

  15. NOS1 S-nitrosylates PTEN and inhibits autophagy in nasopharyngeal carcinoma cells

    PubMed Central

    Zhu, Lingqun; Li, Linlin; Zhang, Qianbing; Yang, Xiao; Zou, Zhiwei; Hao, Bingtao; Marincola, Francesco M; Liu, Zhengjun; Zhong, Zhuo; Wang, Meng; Li, Xiaoxuan; Wang, Qianli; Li, Keyi; Gao, Wenwen; Yao, Kaitai; Liu, Qiuzhen

    2017-01-01

    Autophagy is a cellular survival mechanism that involves the catabolic degradation of damaged proteins and organelles during periods of metabolic stress, and when overly stimulated, commonly contributes to cell death. Nitric oxide (NO), a potent cellular messenger, participates in a complex mechanism which assists in controlling autophagy. However, the mechanism by which endogenous NO formed by distinct isoforms of nitric oxide synthase (NOS) helps to regulate autophagy in cancer cells remains unclear. Here we report that NOS1 reduces excessive levels of autophagy and promotes the survival of nasopharyngeal carcinoma cells. We found that inhibition of NOS1 increased cell death resulting from siRNA or the use of pharmacologic agents; and this effect was reversed by the autophagy inhibitor, chloroquine. The role of NOS1 in the autophagy process depended on the activation of AKT/mTOR signaling by S-nitrosylation of phosphatase and tensin homolog (PTEN) proteins. The mechanism by which NOS1 modifies PTEN protein might involve a direct interaction between these two molecules. Moreover, in an in vivo study, the NOS1 inhibitor N(G)-nitro-L-arginine methyl ester activated AKT/mTOR signaling and promoted autophagy in xenograph tumors. Our studies demonstrated that NOS1 prevents excessive autophagy via S-nitrosylation of PTEN, and activation of the AKT/mTOR signaling pathway. PTEN and the AKT/mTOR signaling pathway are promising targets for improving the chemotherapeutic treatment of cancer. PMID:28243469

  16. PGE1 analog alprostadil induces VEGF and eNOS expression in endothelial cells.

    PubMed

    Haider, Dominik G; Bucek, Robert A; Giurgea, Aura G; Maurer, Gerald; Glogar, Helmut; Minar, Erich; Wolzt, Michael; Mehrabi, Mohammad R; Baghestanian, Mehrdad

    2005-11-01

    Endothelial nitric oxide synthase (eNOS), VEGF, and hypoxia-inducible factor 1-alpha (HIF-1alpha) are important regulators of endothelial function, which plays a role in the pathophysiology of heart failure (HF). PGE1 analog treatment in patients with HF elicits beneficial hemodynamic effects, but the precise mechanisms have not been investigated. We have investigated the effects of the PGE1 analog alprostadil on eNOS, VEGF, and HIF-1alpha expression in human umbilical vein endothelial cells (HUVEC) using RT-PCR and immunoblotting under normoxic and hypoxic conditions. In addition, we studied protein expression by immunohistochemical staining in explanted hearts from patients with end-stage HF, treated or untreated with systemic alprostadil. Alprostadil causes an upregulation of eNOS and VEGF protein and mRNA expression in HUVEC and decreases HIF-1alpha. Hypoxia potently increased eNOS, VEGF, and HIF-1alpha synthesis. The alprostadil-induced upregulation of eNOS and VEGF was prevented by inhibition of MAPKs with PD-98056 or U-0126. Consistently, the expression of eNOS and VEGF was increased, and HIF-1alpha was reduced in failing hearts treated with alprostadil. The potent effects of alprostadil on endothelial VEGF and eNOS synthesis may be useful for patients with HF where endothelial dysfunction is involved in the disease process.

  17. Localization of NGF and nNOS in varicocele-induced rat testis.

    PubMed

    Celik-Ozenci, Ciler; Bayram, Zubeyde; Akkoyunlu, Gokhan; Korgun, Emin Turkay; Erdogru, Tibet; Seval, Yasemin; Ustunel, Ismail; Baykara, Mehmet; Demir, Ramazan

    2006-01-01

    Nerve growth factor (NGF) is synthesized in male germ cells. The presence of neuronal nitric oxide synthase (nNOS) in Leydig cells is related to its role in the regulation of testosterone release. Varicocele is often characterized by abnormal sperm quality and influences the fertilizing capacity of the haploid gamete. We investigated the localization of NGF and nNOS in testes of adult Wistar rats with experimentally induced varicocele after 9, 11, and 13 weeks, as well as in sham-operated controls by immunohistochemistry and Western blot. In control testis, we detected NGF in nuclei of Sertoli cells and also as small vesicular-like structures in the cytoplasm of primary spermatocytes, and in round and elongating spermatids. Varicocele-induction revealed a slight decrease of NGF at 13 weeks, especially in Sertoli cells. In control tissue, nNOS protein was present mainly in Leydig cells and in Sertoli cell cytoplasm. Additionally, nNOS immunoreactivity was present in the heads of elongated spermatids. Western blot results revealed that the decrease of NGF was not significant in the 13-week varicocele group, moreover, the amount of nNOS was not altered in any of the varicocele groups. In conclusion, NGF and nNOS have important roles for normal gametogenesis and our data for the first time indicates that varicocele induction does not necessarily affect the expression of NGF and nNOS. Thus, these two molecules do not appear to be related to varicocele induction.

  18. Diversity of nitrous oxide reductase (nosZ) genes in continental shelf sediments

    SciTech Connect

    Scala, D.J.; Kerkhof, L.J.

    1999-04-01

    Diversity of the nitrous oxide reductase (nosZ) gene was examined in sediments obtained from the Atlantic Ocean and Pacific Ocean continental shelves. Approximately 1,100 bp of the nosZ gene were amplified via PCR, using nosZ gene-specific primers. Thirty-seven unique copies of the nosZ gene from these marine environments were characterized, increasing the nosZ sequence database fourfold. The average DNA similarity for comparisons between all 49 variants of the nosZ gene was 64% {+-} 10%. Alignment of the derived amino acid sequences confirmed the conservation of important structural motifs. A highly conserved region is proposed as the copper binding, catalytic site (Cu{sub z}) of the mature protein. Phylogenetic analysis demonstrated three major clusters of nosZ genes, with little overlap between environmental and culture-based groups. Finally, the two non-culture-based gene clusters generally corresponded to sampling location, implying that denitrifier communities may be restricted geographically.

  19. Efficient Binding of the NOS1AP C-Terminus to the nNOS PDZ Pocket Requires the Concerted Action of the PDZ Ligand Motif, the Internal ExF Site and Structural Integrity of an Independent Element

    PubMed Central

    Li, Li-Li; Cisek, Katryna; Courtney, Michael J.

    2017-01-01

    Neuronal nitric oxide synthase is widely regarded as an important contributor to a number of disorders of excitable tissues. Recently the adaptor protein NOS1AP has emerged as a contributor to several nNOS-linked conditions. As a consequence, the unexpectedly complex mechanisms of interaction between nNOS and its effector NOS1AP have become a particularly interesting topic from the point of view of both basic research and the potential for therapeutic applications. Here we demonstrate that the concerted action of two previously described motif regions contributing to the interaction of nNOS with NOS1AP, the ExF region and the PDZ ligand motif, efficiently excludes an alternate ligand from the nNOS-PDZ ligand-binding pocket. Moreover, we identify an additional element with a denaturable structure that contributes to interaction of NOS1AP with nNOS. Denaturation does not affect the functions of the individual motifs and results in a relatively mild drop, ∼3-fold, of overall binding affinity of the C-terminal region of NOS1AP for nNOS. However, denaturation selectively prevents the concerted action of the two motifs that normally results in efficient occlusion of the PDZ ligand-binding pocket, and results in 30-fold reduction of competition between NOS1AP and an alternate PDZ ligand. PMID:28360833

  20. The social nature of natural childbirth.

    PubMed

    Mansfield, Becky

    2008-03-01

    This paper aims to develop a better understanding of what proponents of natural childbirth mean by "natural." Using a biosocial approach to birth that posits that all birth is both social and natural, the paper investigates how proponents represent the relationship between nature and society. The study asks about what kinds of nature-society relationships are expressed in proponents' representations of natural childbirth. The study examines how natural childbirth is represented by proponents in popular non-fictional English language books written for pregnant women. Claims in these books are not taken as reality, but are analyzed as ideas about nature-society relations. The central finding is that these authors simultaneously emphasize the naturalness of birth and showcase three types of social practices that they describe as being integral to natural childbirth: (1) activity during birth, (2) preparation before birth, and (3) social support, both in an individual and in a broader socio-cultural sense. At least for these authors, it is these social practices that allow natural childbirth to be natural. These findings on the social nature of natural childbirth challenge current social science scholarship, in which natural childbirth is characterized as an essentializing and nostalgic attempt to return to nature.

  1. iNOS expression in dystrophinopathies can be reduced by somatic gene transfer of dystrophin or utrophin.

    PubMed Central

    Louboutin, J. P.; Rouger, K.; Tinsley, J. M.; Halldorson, J.; Wilson, J. M.

    2001-01-01

    BACKGROUND: Nitric oxide (NO) is an inorganic gas produced by a family of NO synthase (NOS) proteins. The presence and the distribution of inducible-NOS (NOS II or iNOS), and NADPH-diaphorase (NADPH-d), a marker for NOS catalytic activity, were determined in muscle sections from control, DMD, and BMD patients. MATERIALS AND METHODS: NADPH-d reactivity, iNOS- and nNOS (NOS I)-immunolocalization were studied in muscles from mdx mice before and after somatic gene transfer of dystrophin or utrophin. RESULTS: In control patients, few fibers (<2%) demonstrated focal accumulation of iNOS in sarcolemma. In DMD patients, a strong iNOS immunoreactivity was observed in some necrotic muscle fibers as well as in some mononuclear cells, and regenerating muscle fibers had diffusely positive iNOS immunoreactivity. In DMD patients, NADPH-d reactivity was increased and mainly localized in regenerating muscle fibers. In mdx mice quadriceps, iNOS expression was mainly observed in regenerating muscle fibers, but not prior to 4 weeks postnatal, and was still present 8 weeks after birth. The expression of dystrophin and the overexpression of utrophin using adenovirus-mediated constructs reduced the number of iNOS-positive fibers in mdx quadriceps muscles. The correction of some pathology in mdx by dystrophin expression or utrophin overexpression was independent of the presence of nNOS. CONCLUSIONS: These results suggest that iNOS could play a role in the physiopathology of DMD and that the abnormal expression of iNOS could be corrected by gene therapy. PMID:11474581

  2. 75 FR 16521 - Virginia Electric and Power Company Surry Power Station, Unit Nos. 1 and 2; Exemption

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-01

    ... COMMISSION Virginia Electric and Power Company Surry Power Station, Unit Nos. 1 and 2; Exemption 1.0 Background The Virginia Electric and Power Company, (the licensee) is the holder of Facility Operating License Nos. DPR-32 and DPR-37, which authorize operation of the Surry Power Station, Unit Nos. 1 and...

  3. 75 FR 75706 - Dresden Nuclear Power Station, Units 2 and 3 and Quad Cities Nuclear Power Station, Unit Nos. 1...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-06

    ... Power Station, Units 2 and 3 and Quad Cities Nuclear Power Station, Unit Nos. 1 and 2; Notice of... Nuclear Power Station, Units 2 and 3, respectively, located in Grundy County, Illinois, and to Renewed Facility Operating License Nos. DPR-29 and DPR-30 for Quad Cities Nuclear Power Station, Unit Nos. 1 and...

  4. 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

    ... COMMISSION Exelon Generation Company, LLC; Peach Bottom Atomic Power Station Unit Nos. 2 and 3; Environmental... operation of Peach Bottom Atomic Power Station (PBAPS), Unit Nos. 2 and 3, located in York and Lancaster... PBAPS, Unit Nos. 2 and 3, demonstrates the feasibility and reliability of the identified OMAs....

  5. 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

  6. Two Views About Explicitly Teaching Nature of Science

    NASA Astrophysics Data System (ADS)

    Duschl, Richard A.; Grandy, Richard

    2013-09-01

    Our focus is on the effects that dated ideas about the nature of science (NOS) have on curriculum, instruction and assessments. First we examine historical developments in teaching about NOS, beginning with the seminal ideas of James Conant. Next we provide an overview of recent developments in philosophy and cognitive sciences that have shifted NOS characterizations away from general heuristic principles toward cognitive and social elements. Next, we analyze two alternative views regarding `explicitly teaching' NOS in pre-college programs. Version 1 is grounded in teachers presenting `Consensus-based Heuristic Principles' in science lessons and activities. Version 2 is grounded in learners experience of `Building and Refining Model-Based Scientific Practices' in critique and communication enactments that occur in longer immersion units and learning progressions. We argue that Version 2 is to be preferred over Version 1 because it develops the critical epistemic cognitive and social practices that scientists and science learners use when (1) developing and evaluating scientific evidence, explanations and knowledge and (2) critiquing and communicating scientific ideas and information; thereby promoting science literacy.

  7. Nox2-dependent glutathionylation of endothelial NOS leads to uncoupled superoxide production and endothelial barrier dysfunction in acute lung injury.

    PubMed

    Wu, Feng; Szczepaniak, William S; Shiva, Sruti; Liu, Huanbo; Wang, Yinna; Wang, Ling; Wang, Ying; Kelley, Eric E; Chen, Alex F; Gladwin, Mark T; McVerry, Bryan J

    2014-12-15

    Microvascular barrier integrity is dependent on bioavailable nitric oxide (NO) produced locally by endothelial NO synthase (eNOS). Under conditions of limited substrate or cofactor availability or by enzymatic modification, eNOS may become uncoupled, producing superoxide in lieu of NO. This study was designed to investigate how eNOS-dependent superoxide production contributes to endothelial barrier dysfunction in inflammatory lung injury and its regulation. C57BL/6J mice were challenged with intratracheal LPS. Bronchoalveolar lavage fluid was analyzed for protein accumulation, and lung tissue homogenate was assayed for endothelial NOS content and function. Human lung microvascular endothelial cell (HLMVEC) monolayers were exposed to LPS in vitro, and barrier integrity and superoxide production were measured. Biopterin species were quantified, and coimmunoprecipitation (Co-IP) assays were performed to identify protein interactions with eNOS that putatively drive uncoupling. Mice exposed to LPS demonstrated eNOS-dependent increased alveolar permeability without evidence for altered canonical NO signaling. LPS-induced superoxide production and permeability in HLMVEC were inhibited by the NOS inhibitor nitro-l-arginine methyl ester, eNOS-targeted siRNA, the eNOS cofactor tetrahydrobiopterin, and superoxide dismutase. Co-IP indicated that LPS stimulated the association of eNOS with NADPH oxidase 2 (Nox2), which correlated with augmented eNOS S-glutathionylation both in vitro and in vivo. In vitro, Nox2-specific inhibition prevented LPS-induced eNOS modification and increases in both superoxide production and permeability. These data indicate that eNOS uncoupling contributes to superoxide production and barrier dysfunction in the lung microvasculature after exposure to LPS. Furthermore, the results implicate Nox2-mediated eNOS-S-glutathionylation as a mechanism underlying LPS-induced eNOS uncoupling in the lung microvasculature.

  8. Context, accuracy, and level of inclusion of nature of science concepts in current high school physics textbooks

    NASA Astrophysics Data System (ADS)

    Alshamrani, Saeed Mohammed

    To improve K-12 students' images of the nature of science (NOS) through science textbooks, two issues must be addressed: (a) the level of NOS that ought to be included in science textbooks and (b) the treatment of this level in those textbooks. Science educators achieved a consensus level of agreement regarding what NOS aspects should be taught for K-12 science learners; however, there is a need for more clarification regarding the actual treatment of NOS in science textbooks. The purpose of this study is to investigate the NOS inclusion in high school physics textbooks. To be specific, this study examines the included NOS aspects, the frequency of NOS inclusion, the contexts exist for NOS inclusion, and the accuracy of NOS inclusion. This study utilized 12 science education studies to develop the Master Aspects of Nature of Science [MA-NOS] which includes 12 NOS aspects that ought to be included in K-12 science curriculum. The analyzed textbooks in this study are seven textbooks identified by The American Institute of Physics as the most widely used high school physics textbooks in the United States in 2005. These textbooks were used in teaching five academic levels: (a) Regular First-Year Physics, (b) Physics for Non-Science Students, (c) Honors Physics, (d) AP-B Physics, and (e) AP-C Physics. The researcher selected exclusively physics textbooks because physics is his main interest. To facilitate the content analysis of the selected textbooks, the study developed The Collection Data Coding Guide which includes six parts describing the MA-NOS aspects and the process of identifying and collecting data. For each NOS aspect, a description and one or more selected ideal indicators were provided to facilitate data collecting and judging the accuracy of NOS inclusion. This coding guide was reviewed for its content validity by two science educators who specialize in NOS. However, two types of reliability were conducted to identify the consistency of selecting NOS units

  9. 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

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Entergy Nuclear Operations, Inc.; Indian Point Nuclear Generating Unit Nos. 2 and 3 AGENCY: Nuclear Regulatory Commission. ACTION: Supplement to Final Supplement 38 to the Generic...

  10. Mitochondrial NOS upregulation during renal I/R causes apoptosis in a peroxynitrite-dependent manner.

    PubMed

    Viñas, J L; Sola, A; Hotter, G

    2006-04-01

    In the last decade, various groups have found evidence of nitric oxide production by mitochondrial nitric oxide synthase (mNOS) in a range of experimental models. However, little is known about the role of mNOS in renal ischemia-reperfusion (I/R) injury and its possible involvement in the apoptotic pathway. We analyzed the role of mNOS in apoptosis promotion in rat kidney I/R and its direct implication through experiments in which isolated kidney mitochondria were subjected to hypoxia/reoxygenation. Results showed that neuronal NOS located in the inner mitochondrial membrane is upregulated during renal I/R and that this upregulation, together with the increase in nitric oxide production, is involved in the generation of intramitochondrial peroxynitrite, which in turn leads to cytochrome c release and apoptosis induction in renal I/R.

  11. Use of natural raw material for the production of photochromic glasses

    SciTech Connect

    Kiyan, V.I.; Artamonova, M.V.; Solinov, V.F.

    1986-07-01

    The authors investigated the possibility of using natural raw materials as replacements for soda and alumina for obtaining photochromic glasses and to determine their properties. Glasses of the sodium aluminoborosilicate system were studied. The characteristics of the batches and some of the properties of the glasses are given in a table. Sodium oxide was added to batches Nos. 1 and 2 as soda or borax. Composition Nos. 3, 4, and 5 were prepared using acid, basic, and neutral rocks by means of which the oxides of sodium and aluminum were added. The glasses were synthesized in SiC-heater furnaces. The differential thermal analysis of compositions Nos. 1 and 5 showed that the presence of natural materials leads to the formation of a liquid phase at lower temperatures which helps to intensify the processes of silicate- and glass-formation.

  12. (−)-Epicatechin activation of endothelial cell eNOS, NO and related signaling pathways

    PubMed Central

    Ramirez-Sanchez, Israel; Maya, Lisandro; Ceballos, Guillermo; Villarreal, Francisco

    2010-01-01

    Recent reports indicate that (−)-epicatechin can exert cardioprotective actions, which may involve eNOS-mediated nitric oxide production in endothelial cells. However, the mechanism by which (−)-epicatechin activates eNOS remains unclear. In this study, we proposed to identify the intracellular pathways involved in (−)-epicatechin-induced effects on eNOS, utilizing human coronary artery endothelial cells in culture. Treatment of cells with (−)-epicatechin leads to time- and dose-dependent effects, which peaked at 10 min at 1 μmol/L. (−)-Epicatechin treatment activates eNOS via serine-633 and serine-1177 phosphorylation and threonine-495 dephosphorylation. Using specific inhibitors, we have established the participation of the PI3K pathway in eNOS activation. (−)-Epicatechin induces eNOS uncoupling from caveolin-1 and its association with calmodulin-1, suggesting the involvement of intracellular calcium. These results allowed us to propose that (−) epicatechin effects may be dependent on actions exerted at the cell membrane level. To test this hypothesis, cells were treated with the phospholipase C inhibitor U73122, which blocked (−)-epicatechin-induced eNOS activation. We also demonstrated inositol phosphate accumulation in (−)-epicatechin-treated cells. The inhibitory effects of the pre-incubation of cells with the CaMKII inhibitor KN-93 indicate that (−)-epicatechin-induced eNOS activation is at least partially mediated via the Ca2+/CaMKII pathway. The (−)-epicatechin stereoisomer catechin was only able to partially stimulate nitric oxide production in cells. Altogether, these results strongly suggest the presence of a cell surface acceptor-effector for the cacao flavanol (−)-epicatechin, which may mediate its cardiovascular effects. PMID:20404222

  13. Mechanism for dynamic regulation of iNOS expression after UVB-irradiation.

    PubMed

    Lu, Wei; Wu, Shiyong

    2013-08-01

    Ultraviolet B (UVB) induces an immediate activation of cNOSs, which contributes to the early release of nitric oxide after irradiation. UVB also induces the expression of iNOS, which peaks at both the mRNA and protein level near 24 h post-irradiation. The induced expression of iNOS contributes largely to the late elevation of nitric oxide after UVB irradiation. However, the regulation of iNOS expression in the early stages of UVB irradiation is not well studied. We previously reported that the UVB-induced early release of nitric oxide leads to the activation of PERK and GCN2, which phosphorylate the alpha-subunit of eIF2 and inhibit protein synthesis. In this report, we demonstrate that eIF2 phosphorylation plays a critical role in regulation of iNOS expression in the early-phase (with in 12 h) of UVB irradiation. Our data shows that with an increased phosphorylation of eIF2, the iNOS protein expression was reduced even though the iNOS mRNA expression was linearly increased in HaCaT and MEF cells after UVB irradiation. The UVB-induced dynamic up- and down-regulation of iNOS expression was almost completely lost in MEF(A/A) cells, which contain a nonphosphorylatable S51A mutation on eIF2. Our results suggest that the UVB-induced eIF2 phosphorylation does not only regulate iNOS expression at the translational level, but at the transcriptional level as well.

  14. 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

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

    NASA Astrophysics Data System (ADS)

    Wan, Zhi Hong; Wong, Siu Ling

    2017-02-01

    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.

  16. 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.

  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. Cloning of iNOS in the small spotted catshark (Scyliorhinus canicula).

    PubMed

    Reddick, Jennifer I; Goostrey, Anna; Secombes, Chris J

    2006-01-01

    The first cartilaginous fish iNOS gene has been cloned in the small spotted catshark, Scyliorhinus canicula. The cDNA was 4568 bp long, with a 3375 bp open reading frame encoding a protein of 1125 amino acids and a predicted molecular mass of 127.8 kDa. The catshark translation had 77% amino acid similarity with chicken iNOS and 70-73% similarity with known teleost i NOS molecules. The various co-factor binding sites were well conserved, with the calmodulin site hydrophobicity profile noticeable more similar to tetrapod molecules than teleost molecules. The catshark iNOS transcript was not typically expressed constitutively, with the exception of the gills. Clear induction of the gene was seen in splenocytes after exposure to Vibrio anguillarum in vivo, and after stimulation with LPS in vitro. iNOS message was first seen 2 h after stimulation, and was still apparent 24 h post-stimulation, the last timing studies. Poly I:C was also able to induce iNOS transcript expression in splenocytes, albeit at a later timing (i.e.24 h). Such findings suggest a role for this molecule in the non-specific defences of cartilaginous fish as seen in other vertebrate groups.

  19. Activation of Endothelial Nitric Oxide (eNOS) Occurs through Different Membrane Domains in Endothelial Cells

    PubMed Central

    Tran, Jason; Magenau, Astrid; Rodriguez, Macarena; Rentero, Carles; Royo, Teresa; Enrich, Carlos; Thomas, Shane R.; Grewal, Thomas; Gaus, Katharina

    2016-01-01

    Endothelial cells respond to a large range of stimuli including circulating lipoproteins, growth factors and changes in haemodynamic mechanical forces to regulate the activity of endothelial nitric oxide synthase (eNOS) and maintain blood pressure. While many signalling pathways have been mapped, the identities of membrane domains through which these signals are transmitted are less well characterized. Here, we manipulated bovine aortic endothelial cells (BAEC) with cholesterol and the oxysterol 7-ketocholesterol (7KC). Using a range of microscopy techniques including confocal, 2-photon, super-resolution and electron microscopy, we found that sterol enrichment had differential effects on eNOS and caveolin-1 (Cav1) colocalisation, membrane order of the plasma membrane, caveolae numbers and Cav1 clustering. We found a correlation between cholesterol-induced condensation of the plasma membrane and enhanced high density lipoprotein (HDL)-induced eNOS activity and phosphorylation suggesting that cholesterol domains, but not individual caveolae, mediate HDL stimulation of eNOS. Vascular endothelial growth factor (VEGF)-induced and shear stress-induced eNOS activity was relatively independent of membrane order and may be predominantly controlled by the number of caveolae on the cell surface. Taken together, our data suggest that signals that activate and phosphorylate eNOS are transmitted through distinct membrane domains in endothelial cells. PMID:26977592

  20. Activation of Endothelial Nitric Oxide (eNOS) Occurs through Different Membrane Domains in Endothelial Cells.

    PubMed

    Tran, Jason; Magenau, Astrid; Rodriguez, Macarena; Rentero, Carles; Royo, Teresa; Enrich, Carlos; Thomas, Shane R; Grewal, Thomas; Gaus, Katharina

    2016-01-01

    Endothelial cells respond to a large range of stimuli including circulating lipoproteins, growth factors and changes in haemodynamic mechanical forces to regulate the activity of endothelial nitric oxide synthase (eNOS) and maintain blood pressure. While many signalling pathways have been mapped, the identities of membrane domains through which these signals are transmitted are less well characterized. Here, we manipulated bovine aortic endothelial cells (BAEC) with cholesterol and the oxysterol 7-ketocholesterol (7KC). Using a range of microscopy techniques including confocal, 2-photon, super-resolution and electron microscopy, we found that sterol enrichment had differential effects on eNOS and caveolin-1 (Cav1) colocalisation, membrane order of the plasma membrane, caveolae numbers and Cav1 clustering. We found a correlation between cholesterol-induced condensation of the plasma membrane and enhanced high density lipoprotein (HDL)-induced eNOS activity and phosphorylation suggesting that cholesterol domains, but not individual caveolae, mediate HDL stimulation of eNOS. Vascular endothelial growth factor (VEGF)-induced and shear stress-induced eNOS activity was relatively independent of membrane order and may be predominantly controlled by the number of caveolae on the cell surface. Taken together, our data suggest that signals that activate and phosphorylate eNOS are transmitted through distinct membrane domains in endothelial cells.

  1. Role of glypican-1 in endothelial NOS activation under various steady shear stress magnitudes.

    PubMed

    Zeng, Ye; Liu, Jingxia

    2016-11-01

    Blood flow patterns in proatherogenic and antiatherogenic regions are rather different. We hypothesize that the laminar flow with steady shear stress increased nitric oxide (NO) bioavailability while disturbed flow with low shear stress reduced it, which is mediating by glypican-1. Thus, we detected the expression of glypican-1 under different shear stress magnitudes, and tested whether the magnitude of shear stress determines the level of endothelial NO synthase (eNOS) via glypican-1 by using phosphatidylinositol phospholipase C (PI-PLC). Results revealed that the expression of glypican-1 depends on the magnitude and duration of shear stress loading. Activation of eNOS in HUVECs is downregulated by 4dyn/cm(2) of shear stress, but is upregulated by 15dyn/cm(2). Removal of glypican-1 significantly suppressed the 15dyn/cm(2) shear stress-induced eNOS activity, and further reduced the 4dyn/cm(2)-inhibited eNOS activity. Therefore, eNOS activation depends on shear stress magnitudes and is mediated by glypican-1. The role of glypican-1 in mediating the eNOS activation under shear stress might involve in protecting the endothelial function against disturbed flow and enhancing the sensitive of the endothelial cell to laminar flow, supporting a potential role of glypican-1 against atherosclerosis.

  2. 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

  3. Fenofibrate activates AMPK and increases eNOS phosphorylation in HUVEC

    SciTech Connect

    Murakami, Hisashi; Murakami, Ryuichiro . E-mail: ryuichi@med.nagoya-u.ac.jp; Kambe, Fukushi; Cao, Xia; Takahashi, Ryotaro; Asai, Toru; Hirai, Toshihisa; Numaguchi, Yasushi; Okumura, Kenji; Seo, Hisao; Murohara, Toyoaki

    2006-03-24

    Fenofibrate improves endothelial function by lipid-lowering and anti-inflammatory effects. Additionally, fenofibrate has been demonstrated to upregulate endothelial nitric oxide synthase (eNOS). AMP-activated protein kinase (AMPK) has been reported to phosphorylate eNOS at Ser-1177 and stimulate vascular endothelium-derived nitric oxide (NO) production. We report here that fenofibrate activates AMPK and increases eNOS phosphorylation and NO production in human umbilical vein endothelial cells (HUVEC). Incubation of HUVEC with fenofibrate increased the phosphorylation of AMPK and acetyl-CoA carboxylase. Fenofibrate simultaneously increased eNOS phosphorylation and NO production. Inhibitors of protein kinase A and phosphatidylinositol 3-kinase failed to suppress the fenofibrate-induced eNOS phosphorylation. Neither bezafibrate nor WY-14643 activated AMPK in HUVEC. Furthermore, fenofibrate activated AMPK without requiring any transcriptional activities. These results indicate that fenofibrate stimulates eNOS phosphorylation and NO production through AMPK activation, which is suggested to be a novel characteristic of this agonist and unrelated to its effects on peroxisome proliferator-activated receptor {alpha}.

  4. Mutation screening of NOS1AP gene in a large sample of psychiatric patients and controls

    PubMed Central

    2010-01-01

    Background The gene encoding carboxyl-terminal PDZ ligand of neuronal nitric oxide synthase (NOS1AP) is located on chromosome 1q23.3, a candidate region for schizophrenia, autism spectrum disorders (ASD) and obsessive-compulsive disorder (OCD). Previous genetic and functional studies explored the role of NOS1AP in these psychiatric conditions, but only a limited number explored the sequence variability of NOS1AP. Methods We analyzed the coding sequence of NOS1AP in a large population (n = 280), including patients with schizophrenia (n = 72), ASD (n = 81) or OCD (n = 34), and in healthy volunteers controlled for the absence of personal or familial history of psychiatric disorders (n = 93). Results Two non-synonymous variations, V37I and D423N were identified in two families, one with two siblings with OCD and the other with two brothers with ASD. These rare variations apparently segregate with the presence of psychiatric conditions. Conclusions Coding variations of NOS1AP are relatively rare in patients and controls. Nevertheless, we report the first non-synonymous variations within the human NOS1AP gene that warrant further genetic and functional investigations to ascertain their roles in the susceptibility to psychiatric disorders. PMID:20602773

  5. Resolution of experimental lung injury by Monocyte-derived inducible nitric oxide synthase (iNOS)

    PubMed Central

    D’Alessio, Franco R.; Tsushima, Kenji; Aggarwal, Neil R.; Mock, Jason R.; Eto, Yoshiki; Garibaldi, Brian T.; Files, Daniel C.; Avalos, Claudia R.; Rodriguez, Jackie V.; Waickman, Adam T.; Reddy, Sekhar P.; Pearse, David B.; Sidhaye, Venkataramana K.; Hassoun, Paul M.; Crow, Michael T.; King, Landon S.

    2012-01-01

    While early events in the pathogenesis of acute lung injury (ALI) have been defined, little is known about mechanisms mediating resolution. To search for determinants of resolution, we exposed wild type (WT) mice to intratracheal lipopolysacaccharide (i.t. LPS) and assessed the response at intervals to day 10, when injury had resolved. Inducible nitric oxide synthase (iNOS) was significantly upregulated in the lung at day 4 after LPS. When iNOS−/− mice were exposed to i.t. LPS, early lung injury was attenuated, however recovery was markedly impaired compared to wild type (WT) mice. iNOS−/− mice had increased mortality and sustained increases in markers of lung injury. Adoptive transfer of WT (iNOS+/+) bone marrow-derived monocytes or direct adenoviral gene delivery of iNOS into injured iNOS−/− mice restored resolution of ALI. Irradiated bone marrow chimeras confirmed the protective effects of myeloid-derived iNOS, but not of epithelial iNOS. Alveolar macrophages exhibited sustained expression of co-signalling molecule CD86 in iNOS−/− mice compared to WT mice. Antibody-mediated blockade of CD86 in iNOS−/− mice improved survival and enhanced resolution of lung inflammation. Our findings show that monocyte-derived iNOS plays a pivotal role in mediating resolution of ALI by modulating lung immune responses, thus facilitating clearance of alveolar inflammation and promoting lung repair. PMID:22844117

  6. iNOS inhibition improves autonomic dysfunction and oxidative status in hypertensive obese rats.

    PubMed

    da Cunha, Natalia Veronez; Lopes, Fernanda Novi Cortegoso; Panis, Carolina; Cecchini, Rubens; Pinge-Filho, Phileno; Martins-Pinge, Marli Cardoso

    2017-01-01

    It has been suggested that nitric oxide (NO) from iNOS source is involved in inflammation and oxidative stress, and hypertension in obese subjects involves an inflammatory process. However, no study evaluated the participation of iNOS inhibition on cardiovascular, autonomic, and inflammatory parameters in obese rats. Obesity was induced by the administration of 4 mg/g body weight of monosodium glutamate (MSG) or equimolar saline (CTR) in newborn rats. On the 60th day, treatment with aminoguanidine (Amino, 50 mg/kg), an iNOS inhibitor, or 0.9% saline, was started. On the 90th day, mean arterial pressure (MAP) and heart rate (HR) were recorded in conscious rats and autonomic modulation was conducted with the CardioSeries software. Plasma samples were collected to assess lipid peroxidation and prostaglandins (PGE2). In addition, iNOS immunohistochemistry in cardiac tissue was evaluated. MSG rats showed hypertension compared to CTR, and Amino treatment did not reverse it. Obese rats presented increased sympathetic and decreased parasympathetic modulation to the heart, reverted by Amino treatment. Plasma PGE2 was increased in obese rats, and Amino treatment decreased. Obese rats presented increased plasma lipoperoxidation, which was decreased after Amino treatment. Also, cardiac iNOS immunohistochemistry was decreased after Amino treatment. Our data suggest that iNOS activation is involved in the systemic and cardiac mechanisms of oxidative stress, inflammation, and autonomic dysfunction derived from obesity.

  7. 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

  8. Epigenetic regulation of nitric oxide synthase 2, inducible (Nos2) by NLRC4 inflammasomes involves PARP1 cleavage.

    PubMed

    Buzzo, Carina de Lima; Medina, Tiago; Branco, Laura M; Lage, Silvia L; Ferreira, Luís Carlos de Souza; Amarante-Mendes, Gustavo P; Hottiger, Michael O; De Carvalho, Daniel D; Bortoluci, Karina R

    2017-02-02

    Nitric oxide synthase 2, inducible (Nos2) expression is necessary for the microbicidal activity of macrophages. However, NOS2 over-activation causes multiple inflammatory disorders, suggesting a tight gene regulation is necessary. Using cytosolic flagellin as a model for inflammasome-dependent NOS2 activation, we discovered a surprising new role for NLRC4/caspase-1 axis in regulating chromatin accessibility of the Nos2 promoter. We found that activation of two independent mechanisms is necessary for NOS2 expression by cytosolic flagellin: caspase-1 and NF-κB activation. NF-κB activation was necessary, but not sufficient, for NOS2 expression. Conversely, caspase-1 was necessary for NOS2 expression, but dispensable for NF-κB activation, indicating that this protease acts downstream NF-κB activation. We demonstrated that epigenetic regulation of Nos2 by caspase-1 involves cleavage of the chromatin regulator PARP1 (also known as ARTD1) and chromatin accessibility of the NF-κB binding sites located at the Nos2 promoter. Remarkably, caspase-1-mediated Nos2 transcription and NO production contribute to the resistance of macrophages to Salmonella typhimurium infection. Our results uncover the molecular mechanism behind the constricted regulation of Nos2 expression and open new therapeutic opportunities based on epigenetic activities of caspase-1 against infectious and inflammatory diseases.

  9. Epigenetic regulation of nitric oxide synthase 2, inducible (Nos2) by NLRC4 inflammasomes involves PARP1 cleavage

    PubMed Central

    Buzzo, Carina de Lima; Medina, Tiago; Branco, Laura M.; Lage, Silvia L.; Ferreira, Luís Carlos de Souza; Amarante-Mendes, Gustavo P.; Hottiger, Michael O.; De Carvalho, Daniel D.; Bortoluci, Karina R.

    2017-01-01

    Nitric oxide synthase 2, inducible (Nos2) expression is necessary for the microbicidal activity of macrophages. However, NOS2 over-activation causes multiple inflammatory disorders, suggesting a tight gene regulation is necessary. Using cytosolic flagellin as a model for inflammasome-dependent NOS2 activation, we discovered a surprising new role for NLRC4/caspase-1 axis in regulating chromatin accessibility of the Nos2 promoter. We found that activation of two independent mechanisms is necessary for NOS2 expression by cytosolic flagellin: caspase-1 and NF-κB activation. NF-κB activation was necessary, but not sufficient, for NOS2 expression. Conversely, caspase-1 was necessary for NOS2 expression, but dispensable for NF-κB activation, indicating that this protease acts downstream NF-κB activation. We demonstrated that epigenetic regulation of Nos2 by caspase-1 involves cleavage of the chromatin regulator PARP1 (also known as ARTD1) and chromatin accessibility of the NF-κB binding sites located at the Nos2 promoter. Remarkably, caspase-1-mediated Nos2 transcription and NO production contribute to the resistance of macrophages to Salmonella typhimurium infection. Our results uncover the molecular mechanism behind the constricted regulation of Nos2 expression and open new therapeutic opportunities based on epigenetic activities of caspase-1 against infectious and inflammatory diseases. PMID:28150715

  10. Ellagic acid protects endothelial cells from oxidized low-density lipoprotein-induced apoptosis by modulating the PI3K/Akt/eNOS pathway

    SciTech Connect

    Ou, Hsiu-Chung; Lee, Wen-Jane; Lee, Shin-Da; Huang, Chih-Yang; Chiu, Tsan-Hung; Tsai, Kun-Ling; Hsu, Wen-Cheng; Sheu, Wayne Huey-Herng

    2010-10-15

    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 investigated 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.

  11. Apoptosis in testicular tissue of rats after vasectomy: evaluation of eNOS, iNOS immunoreactivities and the effects of ozone therapy

    PubMed Central

    Alpcan, Serhan; Başar, Halil; Aydos, Tolga Reşat; Kul, Oğuz; Kısa, Üçler; Başar, Murad Mehmet

    2014-01-01

    Objective: We aimed to investigate the changes in endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (iNOS) expression and apoptotic index in rat testicular tissue, as well as serum and seminal plasma sex hormone levels after vasectomy, and the effect of ozone therapy (OT). Material and methods: Adult male Wistar rats were used (n=6 per group). Control (G1), sham for 4 weeks (G2) or 6 weeks (G3), orchiectomy at the 4th (G4) or 6th (G5) week after left vasectomy, orchiectomy at the 4th (G6) or 6th (G7) week after bilateral vasectomy, orchiectomy after 6 weeks OT following left (G8) or bilateral (G9) vasectomy, orchiectomy after 6 weeks OT (G10). Results: In the left testes, while there were increases in eNOS and iNOS immunoreactivity and apoptotic indexes in G4 and G5, no changes were observed in contralateral testis. These values increased in G6 and G7, while OT inhibited these parameters in the left testis of G8 and both testes of G9. Sex hormone levels did not show any changes after vasectomy and ozone therapy. Conclusion: While OT was found to be protective against some parameters mentioned above under stress conditions, it seemed to cause some harmful effects when used in healthy conditions. PMID:26328178

  12. 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.

  13. Coexpression of COX-2 and iNOS in Angiogenesis of Superficial Esophageal Squamous Cell Carcinoma.

    PubMed

    Kumagai, Youichi; Sobajima, Jun; Higashi, Morihiro; Ishiguro, Toru; Fukuchi, Minoru; Ishibashi, Keiichiro; Mochiki, Erito; Yakabi, Koji; Kawano, Tatsuyuki; Tamaru, Jun-ichi; Ishida, Hideyuki

    2015-04-01

    Using immunohistochemical staining, the present study was conducted to examine whether cyclooxygenase (COX)-2 and inducible nitric oxide synthase (iNOS) affect angiogenesis in early-stage esophageal squamous cell carcinoma (ESCC). We also analyzed the correlation between these two factors. Cyclooxygenase 2, iNOS, and angiogenesis in early-stage ESCC are unclear. Using 10 samples of normal squamous epithelium, 7 samples of low-grade intraepithelial neoplasia (LGIN), and 45 samples of superficial esophageal cancer, we observed the expression of COX-2 and iNOS. We then investigated the COX-2 and iNOS immunoreactivity scores and the correlation between COX-2 or iNOS scores and microvessel density (MVD) using CD34 or CD105. The intensity of COX-2 or iNOS expression differed significantly according to histological type (P < 0.001). The scores of COX-2 and iNOS were lowest for normal squamous epithelium, followed in ascending order by LGIN, carcinoma in situ and tumor invading the lamina propria mucosae (M1-M2 cancer); and tumor invading the muscularis mucosa (M3) or deeper cancer. The differences were significant (P < 0.001). Cancers classified M1-M2 (P < 0.01 and P < 0.05, respectively); M3; or deeper cancer (P < 0.01) had significantly higher COX-2 and iNOS scores than normal squamous epithelium. There was a significant correlation between COX-2 and iNOS scores (P < 0.001, rs = 0.51). Correlations between COX-2 score and CD34-positive MVD or CD105-positive MVD were significant (rs = 0.53, P < 0.001; rs = 0.62, P < 0.001, respectively). Inducible nitric oxide synthase score was also significantly correlated with CD34 MVD and CD105 MVD (rs = 0.45, P < 0.001; rs = 0.60, P < 0.001, respectively). Chemoprevention of COX-2 or iNOS activity may blunt the development of ESCC from precancerous lesions.

  14. 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.

  15. Epistemology and the nature of science: Implications for preservice elementary science programs

    NASA Astrophysics Data System (ADS)

    Stockton, Jamie D.

    The purpose of this study was to look at the possible interface between college students' epistemological orientation (ways of knowing) and their views on the nature of science (NOS). Eighty-one undergraduate participants were asked to engage in both an interview that focused on their views of the nature of science (VNOS-C, Abd-El-Khalick, 1998) and the RCI (Reasoning about Current Issues) questionnaire based upon Patricia King and Karen Strohm Kitchener's (1994) Reflective Judgment Model (RJM). Three groups of students were used: science majors, elementary education majors, and nonscience non-education majors. The VNOS interviews were assessed using a five point likert scale, also designed by Abd-El-Khalick (but modified for this study), while the RCI was rated in terms of comparisons of responses to the seven stages of the RJM. Results indicated a significant difference for views of NOS between science majors and the other two groupings. Trends for educational level and major discipline were the same across instruments. Furthermore, the statistical analyses conducted on the various groups supported in part the author's hypotheses of a developmental component to NOS. The strongest implication for preservice elementary science programs is the need for direct, interactive instruction on NOS so that misconceptions on NOS will not be perpetuated in the cycle of learning in future elementary classrooms.

  16. Analysis of Saudi Arabian middle and high school science teachers' conceptions of the nature of science

    NASA Astrophysics Data System (ADS)

    Almazroa, Hiya Mohammed

    This study was conducted to explore Saudi middle and high school science teachers' conceptions of the Nature of Science (NOS). It also detected the effects of gender, science content major, and years of teaching experience on teachers' conceptions of the NOS. The study included a sample of 786 science teachers (137 male and 649 female) who were teaching in middle and high schools in Riyadh, Saudi Arabia in the 1995-1996 academic year. The study was conducted using a translated version of the Nature of Science Scale (NOSS) developed by Kimball (1967). The scale contains 29 items ranging from "agree" to "disagree", and the scoring of the items ranged from 29 to 87. The lowest score is 29 (1 x 29) and the highest score possible on the test is 87 (3 x 29 items). The data collected was statistically analyzed using descriptive statistics and Analysis of Variance (ANOVA). The study revealed that Saudi science teachers as a group hold numerous misconceptions about the NOS with a significant difference in understanding the NOS between the male and female teachers. The study also showed that teachers with a major in physics held more adequate views than did teachers with other majors. In addition, novice teachers were found to have more adequate conceptions of the NOS than did experienced teachers.

  17. Teachers' Knowledge Structures for Nature of Science and Scientific Inquiry and Their Classroom Practice

    ERIC Educational Resources Information Center

    Bartos, Stephen A.

    2013-01-01

    Research on nature of science (NOS) and scientific inquiry (SI) has indicated that a teacher's knowledge of each, however well developed, is not sufficient to ensure that these views necessarily manifest themselves in classroom practice (Lederman & Druger, 1985; Lederman, 2007). In light of the considerable research that has examined teachers'…

  18. Teachers' Knowledge Structures for Nature of Science and Scientific Inquiry: Conceptions and Classroom Practice

    ERIC Educational Resources Information Center

    Bartos, Stephen A.; Lederman, Norman G.

    2014-01-01

    Research on nature of science (NOS) and scientific inquiry (SI) has indicated that a teacher's knowledge of each, however well developed, is not sufficient to ensure that these conceptions necessarily manifest themselves in classroom practice (Lederman & Druger, 1985; Lederman, 2007). In light of considerable research that has examined…

  19. 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…

  20. 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…

  1. 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…

  2. Exploring the Relationships among Epistemological Beliefs, Metacognitive Awareness and Nature of Science

    ERIC Educational Resources Information Center

    Ozgelen, Sinan

    2012-01-01

    This study aims to investigate the relationships among epistemological beliefs, metacognitive awareness, and nature of science (NOS). Participants were 45 preservice science teachers (PSTs) enrolled in two sections of Laboratory Application in Science II course in a university in Turkey. All of the participants were juniors with the same science…

  3. 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…

  4. 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.…

  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. 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…

  7. Students and School Characteristics Related to Elementary School Students' Views of the Nature of Science

    ERIC Educational Resources Information Center

    Hacieminoglu, Esme; Ertepinar, Hamide; Yilmaz-Tüzün, Özgul; Çakir, Hasan

    2015-01-01

    The purpose of this study is to investigate student- and school-level factors that help to explain the difference in the nature of science (NOS) views. Overall, the design of this study is correlational. The sample consisted of 3062 students enrolled in the sixth, seventh, and eighth grades of elementary schools in Turkey. A hierarchical linear…

  8. 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…

  9. 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…

  10. Teaching the Nature of Science through the Millikan-Ehrenhaft Dispute

    ERIC Educational Resources Information Center

    Paraskevopoulou, Eleni; Koliopoulos, Dimitris

    2011-01-01

    This article presents the results of a research project that investigated the extent to which the use of the historical episode of the Millikan-Ehrenhaft dispute over the existence of the elementary electric charge can improve students' conceptions of specific aspects of the Nature of Science (NOS). A teaching programme containing seven hourly…

  11. 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,"…

  12. 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,…

  13. 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…

  14. 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…

  15. 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,…

  16. A Critical Hermeneutic Study: Third Grade Elementary African American Students' Views of the Nature of Science

    ERIC Educational Resources Information Center

    Walls, Leon

    2009-01-01

    Nature of Science is one of the most fundamental aspects of understanding science. How different cultures, races and ethnicities see and interpret science differently is critical. However, the NOS views specific to African American teachers and learners have gone largely unresearched. The views of a purposeful sample of African American third…

  17. 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.

  18. 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…

  19. What Can Inservice Taiwanese Science Teachers Learn and Teach about the Nature of Science?

    ERIC Educational Resources Information Center

    Tuan, Hsiao-lin; Chin, Chi-Chin

    The purpose of this study was to investigate aspects of the Nature of Science (NOS) concepts and teaching practices acquired by inservice teachers who participated in a teacher education program at the National Changhua University of Education in Taiwan. Two instructors used both case-history and demonstration approaches to help science teachers…

  20. 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…

  1. 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…

  2. 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,…

  3. 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…

  4. 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…

  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. Striatal NOS1 has dimorphic expression and activity under stress and nicotine sensitization.

    PubMed

    Díaz, David; Murias, Azucena Rodrigo; Ávila-Zarza, Carmelo Antonio; Muñoz-Castañeda, Rodrigo; Aijón, José; Alonso, José Ramón; Weruaga, Eduardo

    2015-10-01

    Nicotine exerts its addictive influence through the meso-cortico-limbic reward system, where the striatum is essential. Nicotine addiction involves different neurotransmitters, nitric oxide (NO) being especially important, since it triggers the release of the others by positive feedback. In the nervous system, NO is mainly produced by nitric oxide synthase 1 (NOS1). However, other subtypes of synthases can also synthesize NO, and little is known about the specific role of each isoform in the process of addiction. In parallel, NOS activity and nicotine addiction are also affected by stress and sexual dimorphism. To determine the specific role of this enzyme, we analyzed both NOS expression and NO synthesis in the striatum of wild-type and NOS1-knocked out (KO) mice of both sexes in situations of nicotine sensitization and stress. Our results demonstrated differences between the caudate-putamen (CP) and nucleus accumbens (NA). With respect to NOS1 expression, the CP is a dimorphic region (27.5% lower cell density in males), but with a stable production of NO, exclusively due to this isoform. Thus, the nitrergic system of CP may not be involved in stress or nicotine addiction. Conversely, the NA is much more variable and strongly involved in both situations: its NO synthesis displays dimorphic variations at both basal (68.5% reduction in females) and stress levels (65.9% reduction in males), which disappear when nicotine is infused. Thus, the KO animals showed an increase in NO production (21.7%) in the NA, probably by NOS3, in an attempt to compensate the lack of NOS1.

  7. 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.

  8. Puerarin protects rat kidney from lead-induced apoptosis by modulating the PI3K/Akt/eNOS pathway

    SciTech Connect

    Liu, Chan-Min; Ma, Jie-Qiong; Sun, Yun-Zhi

    2012-02-01

    Puerarin (PU), a natural flavonoid, has been reported to have many benefits and medicinal properties. However, its protective effects against lead (Pb) induced injury in kidney have not been clarified. The aim of the present study was to investigate the effects of puerarin on renal oxidative stress and apoptosis in rats exposed to Pb. Wistar rats were exposed to lead acetate in the drinking water (500 mg Pb/l) with or without puerarin co-administration (100, 200, 300 and 400 mg PU/kg intragastrically once daily) for 75 days. Our data showed that puerarin significantly prevented Pb-induced nephrotoxicity in a dose-dependent manner, indicated by both diagnostic indicators of kidney damage (serum urea, uric acid and creatinine) and histopathological analysis. Moreover, Pb-induced profound elevation of reactive oxygen species (ROS) production and oxidative stress, as evidenced by increasing of lipid peroxidation level and depleting of intracellular reduced glutathione (GSH) level in kidney, were suppressed by treatment with puerarin. Furthermore, TUNEL assay showed that Pb-induced apoptosis in rat kidney was significantly inhibited by puerarin. In exploring the underlying mechanisms of puerarin action, we found that activities of caspase-3 were markedly inhibited by the treatment of puerarin in the kidney of Pb-treated rats. Puerarin increased phosphorylated Akt, phosphorylated eNOS and NO levels in kidney, which in turn inactivated pro-apoptotic signaling events including inhibition of mitochondria cytochrome c release and restoration of the balance between pro- and anti-apoptotic Bcl-2 proteins in kidney of Pb-treated rats. In conclusion, these results suggested that the inhibition of Pb-induced apoptosis by puerarin is due at least in part to its antioxidant activity and its ability to modulate the PI3K/Akt/eNOS signaling pathway. Highlights: ► Puerarin prevented lead-induced nephrototoxicity. ► Puerarin reduced lead-induced increase in ROS and TBARS production

  9. Natural Language Processing.

    ERIC Educational Resources Information Center

    Chowdhury, Gobinda G.

    2003-01-01

    Discusses issues related to natural language processing, including theoretical developments; natural language understanding; tools and techniques; natural language text processing systems; abstracting; information extraction; information retrieval; interfaces; software; Internet, Web, and digital library applications; machine translation for…

  10. Ginsenoside Rg3 regulates S-nitrosylation of the NLRP3 inflammasome via suppression of iNOS

    SciTech Connect

    Yoon, Sung-Jin; Park, Jun-Young; Choi, Song; Lee, Jin-Bong; Jung, Haiyoung; Kim, Tae-Don; Yoon, Suk Ran; Choi, Inpyo; Shim, Sungbo; Park, Young-Jun

    2015-08-07

    Ginsenoside Rg3, a specific biological effector, is well-known as a major bioactive ingredient of Panax ginseng. However, its role in the inflammasome activation process remains unclear. In this report, we demonstrate that ginsenosides 20(R)-Rg3 and 20(S)-Rg3 are capable of suppressing both lethal endotoxic shock and the S-nitrosylation of the NLRP3 inflammasome by inhibiting nitric oxide (NO) production through the regulation of inducible nitric oxide synthase (iNOS) expression. In response to lipopolysaccharide (LPS), the reducing effect of 20(S)-Rg3 and 20(R)-Rg3 on nitric oxide led to an increase in the survival time of mice after lethal endotoxin-induced shock, and excess levels of NO inhibited IL-1β production via the S-nitrosylation of the NLRP3 inflammasome. In addition, ginsenosides 20(R)-Rg3 and 20(S)-Rg3 had suppressive effects on the LPS- or UV-irradiation-induced reactive oxygen species (ROS) levels in macrophage and HaCaT cells and thereby prevented apoptosis of spleen cells in mice. Altogether, these results demonstrate that ginsenoside 20(R)-Rg3 and 20(S)-Rg3, a naturally occurring compound, might act as a dual therapeutic regulator for the treatment of inflammatory and oxidative stress-related diseases. - Highlights: • Ginsenosides Rg3 inhibits NO production through the regulation of iNOS expression. • Ginsenosides Rg3 inhibits the S-nitrosylation of the NLRP3 inflammasome. • Ginsenosides Rg3 suppress on the LPS- or UV-irradiation-induced ROS levels in cells.

  11. Arginine induces GH gene expression by activating NOS/NO signaling in rat isolated hemi-pituitaries

    PubMed Central

    Olinto, S.C.F.; Adrião, M.G.; Castro-Barbosa, T.; Goulart-Silva, F.; Nunes, M.T.

    2012-01-01

    The amino acid arginine (Arg) is a recognized secretagogue of growth hormone (GH), and has been shown to induce GH gene expression. Arg is the natural precursor of nitric oxide (NO), which is known to mediate many of the effects of Arg, such as GH secretion. Arg was also shown to increase calcium influx in pituitary cells, which might contribute to its effects on GH secretion. Although the mechanisms involved in the effects of Arg on GH secretion are well established, little is known about them regarding the control of GH gene expression. We investigated whether the NO pathway and/or calcium are involved in the effects of Arg on GH gene expression in rat isolated pituitaries. To this end, pituitaries from approximately 170 male Wistar rats (∼250 g) were removed, divided into two halves, pooled (three hemi-pituitaries) and incubated or not with Arg, as well as with different pharmacological agents. Arg (71 mM), the NO donor sodium nitroprusside (SNP, 1 and 0.1 mM) and a cyclic guanosine monophosphate (cGMP) analogue (8-Br-cGMP, 1 mM) increased GH mRNA expression 60 min later. The NO acceptor hemoglobin (0.3 µM) blunted the effect of SNP, and the combined treatment with Arg and L-NAME (an NO synthase (NOS) inhibitor, 55 mM) abolished the stimulatory effect of Arg on GH gene expression. The calcium channel inhibitor nifedipine (3 µM) also abolished Arg-induced GH gene expression. The present study shows that Arg directly induces GH gene expression in hemi-pituitaries isolated from rats, excluding interference from somatostatinergic neurons, which are supposed to be inhibited by Arg. Moreover, the data demonstrate that the NOS/NO signaling pathway and calcium mediate the Arg effects on GH gene expression. PMID:22641416

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

    SciTech Connect

    Nagane, Masaki; Yasui, Hironobu; Sakai, Yuri; Yamamori, Tohru; Niwa, Koichi; Hattori, Yuichi; Kondo, Takashi; Inanami, Osamu

    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 by 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.

  13. The nature and ethics of natural experiments.

    PubMed

    Dawson, Angus; Sim, Julius

    2015-10-01

    Natural experiments are an important methodology often used to answer research questions that would, otherwise, be impossible to address, or employed because of ethical concerns about the use of randomisation to interventions that carry known risks. The UK Medical Research Council (MRC) recently produced an extremely useful document discussing the nature and significance of natural experiments within medical and public health research. In this paper, however, we suggest that the MRC document's definition of the term 'natural experiment' is insufficiently precise. In response, we offer a taxonomy of different types of natural experiments and related methods, and explore the ethical implications of these different types. We argue that while the ethical issues that may arise within natural experiments in relation to risks of harm or informed consent may differ from those within the randomised controlled trial, they are not thereby less pressing. The implications of the argument are explored and recommendations made for those involved in research governance.

  14. Role of endothelial nitric oxide synthase (eNOS) in chronic stress-promoted tumour growth

    PubMed Central

    Barbieri, Antonio; Palma, Giuseppe; Rosati, Alessandra; Giudice, Aldo; Falco, Antonia; Petrillo, Antonella; Petrillo, Mario; Bimonte, Sabrina; Benedetto, Maria Di; Esposito, Giuseppe; Stiuso, Paola; Abbruzzese, Alberto; Caraglia, Michele; Arra, Claudio

    2012-01-01

    Abstract Accumulating evidence suggests that chronic stress can be a cofactor for the initiation and progression of cancer. Here we evaluated the role of endothelial nitric oxide synthase (eNOS) in stress-promoted tumour growth of murine B16F10 melanoma cell line in C57BL/6 mice. Animals subjected to restraint stress showed increased levels adrenocorticotropic hormone, enlarged adrenal glands, reduced thymus weight and a 3.61-fold increase in tumour growth in respect to no-stressed animals. Tumour growth was significantly reduced in mice treated with the β-antagonist propranolol. Tumour samples obtained from stressed mice displayed high levels of vascular endothelial growth factor (VEGF) protein in immunohistochemistry. Because VEGF can induce eNOS increase, and nitric oxide is a relevant factor in angiogenesis, we assessed the levels of eNOS protein by Western blot analysis. We found a significant increase in eNOS levels in tumour samples from stressed mice, indicating an involvement of this enzyme in stress-induced tumour growth. Accordingly, chronic stress did not promote tumour growth in eNOS−/− mice. These results disclose for the first time a pivotal role for eNOS in chronic stress-induced initiation and promotion of tumour growth. PMID:21722303

  15. The Neurological Outcome Scale for Traumatic Brain Injury (NOS-TBI): I. Construct validity.

    PubMed

    Wilde, Elisabeth A; McCauley, Stephen R; Kelly, Tara M; Weyand, Annie M; Pedroza, Claudia; Levin, Harvey S; Clifton, Guy L; Schnelle, Kathleen P; Shah, Monika V; Moretti, Paolo

    2010-06-01

    The Neurological Outcome Scale for Traumatic Brain Injury (NOS-TBI) is a measure adapted from the National Institutes of Health Stroke Scale (NIHSS), and is intended to capture essential neurological deficits impacting individuals with traumatic brain injury (TBI) (see Wilde et al., 2010 ). In the present study we evaluate the measure's construct validity via comparison with a quantified neurological examination performed by a neurologist. Spearman rank-order correlation between the NOS-TBI and the neurological examination was rho = 0.76, p < 0.0001, suggesting a high degree of correspondence (construct validity) between these two measures of neurological function. Additionally, items from the NOS-TBI compared favorably to the neurological examination items, with correlations ranging from 0.60 to 0.99 (all p < 0.0001). On formal neurological examination, some degree of neurological impairment was observed in every participant in this cohort of individuals undergoing rehabilitation for TBI, and on the NOS-TBI neurological impairment was evident in all but one participant. This study documents the presence of measurable neurological sequelae in a sample of patients with TBI in a post-acute rehabilitation setting, underscoring the need for formal measurement of the frequency and severity of neurological deficits in this population. The results suggest that the NOS-TBI is a valid measure of neurological functioning in patients with TBI.

  16. 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

  17. 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

  18. L-theanine promotes nitric oxide production in endothelial cells through eNOS phosphorylation.

    PubMed

    Siamwala, Jamila H; Dias, Paul M; Majumder, Syamantak; Joshi, Manoj K; Sinkar, Vilas P; Banerjee, Gautam; Chatterjee, Suvro

    2013-03-01

    Consumption of tea (Camellia sinensis) improves vascular function and is linked to lowering the risk of cardiovascular disease. Endothelial nitric oxide is the key regulator of vascular functions in endothelium. In this study, we establish that l-theanine, a non-protein amino-acid found in tea, promotes nitric oxide (NO) production in endothelial cells. l-theanine potentiated NO production in endothelial cells was evaluated using Griess reaction, NO sensitive electrode and a NO specific fluorescent probe (4-amino-5-methylamino-2',7'-difluororescein diacetate). l-Theanine induced NO production was partially attenuated in presence of l-NAME or l-NIO and completely abolished using eNOS siRNA. eNOS activation was Ca(2+) and Akt independent, as assessed by fluo-4AM and immunoblotting experiments, respectively and was associated with phosphorylation of eNOS Ser 1177. eNOS phosphorylation was inhibited in the presence of ERK1/2 inhibitor, PD-98059 and partially inhibited by PI3K inhibitor, LY-294002 and Wortmanin suggesting PI3K-ERK1/2 dependent pathway. Increased NO production was associated with vasodilation in ex ovo (chorioallantoic membrane) model. These results demonstrated that l-theanine administration in vitro activated ERK/eNOS resulting in enhanced NO production and thereby vasodilation in the artery. The results of our experiments are suggestive of l-theanine mediated vascular health benefits of tea.

  19. Extensive Ethnogenomic Diversity of Endothelial Nitric Oxide Synthase (eNOS) Polymorphisms

    PubMed Central

    Thomas, Bolaji N.; Thakur, Tanya J.; Yi, Li; Guindo, Aldiouma; Diallo, Dapa A.; Ott, Jurg

    2013-01-01

    Nitric oxide (NO) is highly reactive, produced in endothelial cells by endothelial NO synthase (eNOS) and has been implicated in sickle cell pathophysiology. We evaluated the distribution of functionally significant eNOS variants (the T786C variant in the promoter region, the Glu298Asp variant in exon 7, and the variable number of tandem repeats (VNTR) in intron 4) in Africans, African Americans and Caucasians. The C-786 variant was more common in Caucasians than in Africans and African Americans. Consistent with other findings, the Asp-298 variant had the highest frequency in Caucasians followed by African Americans, but was completely absent in Africans. The very rare intron 4 allele, eNOS 4c, was found in some Africans and African Americans, but not in Caucasians. eNOS 4d allele was present in 2 Africans. These findings suggest a consistent and widespread genomic diversity in the distribution of eNOS variants in Africans, comparative to African Americans and Caucasians. PMID:23400313

  20. Inhibition of nNOS and iNOS following hypoxia-ischaemia improves long-term outcome but does not influence the inflammatory response in the neonatal rat brain.

    PubMed

    van den Tweel, Evelyn R W; Peeters-Scholte, Cacha M P C D; van Bel, Frank; Heijnen, Cobi J; Groenendaal, Floris

    2002-01-01

    In this study, we tested the hypothesis that combined inhibition of nNOS and iNOS will reduce neuronal damage and the inflammatory response induced by perinatal hypoxia-ischaemia (HI). In 12-day-old rats, HI was induced by right carotid artery occlusion followed by 90 min of 8% O2. Immediately upon reoxygenation, the rats were treated with NOS inhibitors (n = 24) or placebo (n = 24). Neuropathology was scored at 6 weeks after HI on a 4-point scale (n = 12 per group). The expression of heat shock protein 70 (HSP70) and mRNA expression for cytokines were measured 12 h after HI (n = 12 per group). Histopathological analysis showed that the ipsilateral hemisphere in the NOS inhibition group was less damaged than in the placebo group (p < 0.05). HI induced a significant increase in HSP70 levels (p < 0.05) in the ipsilateral hemispheres, which tended to be lower in the NOS inhibition group (p = 0.07). HI induced an increase in mRNA expression for IL-1beta, TNF-alpha and TNF-beta, but there was no difference between the ipsi- and contralateral hemispheres. Combined inhibition of nNOS and iNOS did not induce any change in cytokine expression. We conclude that the long-term neuroprotective effects of combined nNOS and iNOS inhibition were not achieved by an altered cytokine response.

  1. Increased intracellular Ca(2+) decreases cisplatin resistance by regulating iNOS expression in human ovarian cancer cells.

    PubMed

    Yu, Yang; Xie, Qi; Liu, Weimin; Guo, Yuting; Xu, Na; Xu, Lu; Liu, Shibing; Li, Songyan; Xu, Ye; Sun, Liankun

    2017-02-01

    Previous studies have reported that intracellular Ca(2+) signals and inducible nitric oxide synthase (iNOS) are involved in cell apoptosis. However, the role of iNOS in cisplatin resistance in ovarian cancer remains unclear. Here, we demonstrate that SKOV3/DDP ovarian cancer cells were more resistant to cisplatin than were SKOV3 ovarian cancer cells. The expression of intracellular Ca(2+) and iNOS was more strongly induced by cisplatin in SKOV3 cells than in SKOV3/DDP cells. TAT-conjugated IP3R-derived peptide (TAT-IDP(S)) increased cisplatin-induced iNOS expression and apoptosis in SKOV3/DDP cells. 2-Aminoethoxydiphenyl borate (2-APB) decreased cisplatin-induced iNOS expression and apoptosis in SKOV3 cells. Thus, iNOS induction may be a valuable strategy for improving the anti-tumor efficacy of cisplatin in ovarian cancer.

  2. Naturally occurring chemical carcinogens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Natural products are chemicals found in nature which have unique pharmacological effects. Humans are exposed to many of these bioactive naturally occurring chemicals via the air breathed, the water drunk and the food eaten. Exposure also occurs in clinical settings. Naturally occurring chemicals ...

  3. Engaging Nature Aesthetically

    ERIC Educational Resources Information Center

    Kupfer, Joseph H.

    2003-01-01

    For the most part, most people appreciate nature as spectators. Some portion of a natural scene is viewed as if it were a painting or photograph. However, thinking of nature solely or chiefly as an aesthetic scene to be observed is unnecessarily limiting. Regarding natural phenomena as material for detached, pictorial observation overlooks the…

  4. Burrowing through the Heterogeneity: Review of Mouse Models of PTCL-NOS

    PubMed Central

    Cutucache, Christine E.; Herek, Tyler A.

    2016-01-01

    Currently, there are 19 different peripheral T-cell lymphoma (PTCL) entities recognized by the World Health Organization; however, ~70% of PTCL diagnoses fall within one of three subtypes [i.e., peripheral T-cell lymphoma not otherwise specified (PTCL-NOS), anaplastic large-cell lymphoma, and angioimmunoblastic T-cell lymphoma]. PTCL-NOS is a grouping of extra-thymic neoplasms that represent a challenging and heterogeneous subset of non-Hodgkin’s lymphomas. Research into peripheral T-cell lymphomas has been cumbersome as the lack of defining cytogenetic, histological, and molecular features has stymied diagnosis and treatment of these diseases. Similarly, the lacks of genetically manipulated murine models that faithfully recapitulate disease characteristics were absent prior to the turn of the century. Herein, we review the literature concerning existing mouse models for PTLC-NOS, while paying particular attention to the etiology of this heterogeneous disease. PMID:27725924

  5. Are Temporal Differences in GDNF and NOS Isoform Induction Contributors to Neurodegeneration? A Fluorescence Microscopy-Based Study

    PubMed Central

    Doursout, Marie-Francoise; Liang, Yangyan; Schiess, Mya C.; Padilla, Angelica; Poindexter, Brian J.; Hickson-Bick, Diane L. M.; Bick, Roger J.

    2016-01-01

    Background: Specific factors in Parkinson’s disease have become targets as to their protective and degenerative effects. We have demonstrated that cytokines and PD-CSF detrimentally affect microglia and astrocyte growth. While glial cell-derived neurotrophic factor (GDNF) has been recognized as a possible neuron-rescue agent, nitric oxide synthase (NOS) has been implicated in neurodegenerative processes. Objective: To demonstrate that glial cell activation, cytokine production, and NOS induction, play an intimate role in the loss of dopaminergic signaling, via mechanisms that are a result of inflammation and inflammatory stimuli. Methods: Study animals were sacrificed following endotoxin treatment and tissue sections were harvested and probed for GDNF and NOS isomers by fluorescence deconvolution microscopy. Fluorescence was mapped and quantified for each probe Results: An immune cell influx into ‘vulnerable’ areas of the brain was seen, and three NOS isomers, inducible (iNOS), neuronal (nNOS) and endothelial (eNOS), were synthesized in the brains, a finding which suggests that each isomer has a role in neurodegeneration. eNOS was found associated with blood vessels, while iNOS was associated with glial and matrix cells and nNOS was located with both glia and neurons. Following endotoxin treatment, serum levels of nitric oxide were higher at 6-8 hours, while tissue levels of NOS were elevated for much longer. Thus, induction of NOS occurred earlier than the induction of GDNF. Conclusion: Our findings suggest that the protective abilities of GDNF to combat neural destruction are not available rapidly enough, and do not remain at sufficiently high levels long enough to assert its protective effects. (250). PMID:27651844

  6. NOS2 Is Critical to the Development of Emphysema in Sftpd Deficient Mice but Does Not Affect Surfactant Homeostasis

    PubMed Central

    Guo, Chang-Jiang; Scott, Pamela A.; Haenni, Beat; Beers, Michael F.; Ochs, Matthias; Gow, Andrew J.

    2014-01-01

    Rationale Surfactant protein D (SP-D) has important immuno-modulatory properties. The absence of SP-D results in an inducible NO synthase (iNOS, coded by NOS2 gene) related chronic inflammation, development of emphysema-like pathophysiology and alterations of surfactant homeostasis. Objective In order to test the hypothesis that SP-D deficiency related abnormalities in pulmonary structure and function are a consequence of iNOS induced inflammation, we generated SP-D and iNOS double knockout mice (DiNOS). Methods Structural data obtained by design-based stereology to quantify the emphysema-like phenotype and disturbances of the intracellular surfactant were correlated to invasive pulmonary function tests and inflammatory markers including activation markers of alveolar macrophages and compared to SP-D (Sftpd−/−) and iNOS single knockout mice (NOS2−/−) as well as wild type (WT) littermates. Measurements and Results DiNOS mice had reduced inflammatory cells in BAL and BAL-derived alveolar macrophages showed an increased expression of markers of an alternative activation as well as reduced inflammation. As evidenced by increased alveolar numbers and surface area, emphysematous changes were attenuated in DiNOS while disturbances of the surfactant system remained virtually unchanged. Sftpd−/− demonstrated alterations of intrinsic mechanical properties of lung parenchyma as shown by reduced stiffness and resistance at its static limits, which could be corrected by additional ablation of NOS2 gene in DiNOS. Conclusion iNOS related inflammation in the absence of SP-D is involved in the emphysematous remodeling leading to a loss of alveoli and associated alterations of elastic properties of lung parenchyma while disturbances of surfactant homeostasis are mediated by different mechanisms. PMID:24465666

  7. Detecting Nitrous Oxide Reductase (nosZ) Genes in Soil Metagenomes: Method Development and Implications for the Nitrogen Cycle

    PubMed Central

    Orellana, L. H.; Rodriguez-R, L. M.; Higgins, S.; Chee-Sanford, J. C.; Sanford, R. A.; Ritalahti, K. M.; Löffler, F. E.

    2014-01-01

    ABSTRACT 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. PMID:24895307

  8. Morphology of VIP/nNOS-immunoreactive myenteric neurons in the human gut.

    PubMed

    Brehmer, A; Schrödl, F; Neuhuber, W

    2006-05-01

    In this study, we characterized human myenteric neurons co-immunoreactive for neuronal nitric oxide synthase (nNOS) and vasoactive intestinal peptide (VIP) by their morphology and their proportion as related to the putative entire myenteric neuronal population. Nine wholemounts (small and large intestinal samples) from nine patients were triple-stained for VIP, neurofilaments (NF) and nNOS. Most neurons immunoreactive for all three markers displayed radially emanating, partly branching dendrites with spiny endings. These neurons were called spiny neurons. The spiny character of their dendrites was more pronounced in the small intestinal specimens and differed markedly from enkephalinergic stubby neurons described earlier. Exclusively in the duodenum, some neurons displayed prominent main dendrites with spiny side branches. Of the axons which could be followed from the ganglion of origin within primary strands of the myenteric plexus beyond the next ganglion (70 out of 140 traced neurons), 94.3% run anally and 5.7% orally. Very few neurons reactive for both VIP and nNOS could not be morphologically classified due to weak or absent NF-immunoreactivity. Another six wholemounts were triple-stained for VIP, nNOS and Hu proteins (HU). The proportion of VIP/nNOS-coreactive neurons in relation to the number of HU-reactive neurons was between 5.8 and 11.5% in the small and between 10.6 and 17.5% in the large intestinal specimens. We conclude that human myenteric spiny neurons co-immunoreactive for VIP and nNOS represent either inhibitory motor or descending interneurons.

  9. Key role of endothelium in the eNOS-dependent cardioprotection with exercise training.

    PubMed

    Farah, C; Nascimento, A; Bolea, G; Meyer, G; Gayrard, S; Lacampagne, A; Cazorla, O; Reboul, C

    2017-01-01

    Modulation of endothelial nitric oxide synthase (eNOS) activation is recognized as a main trigger of the cardioprotective effects of exercise training on heart vulnerability to ischemia-reperfusion (IR). However, this enzyme is expressed both in coronary endothelial cells and cardiomyocytes and the contribution of each one to such cardioprotection has never been challenged. The aim of this study was to investigate the role of eNOS from the cardiomyocytes vs. the endothelium in the exercise cardioprotection. Male Wistar rats were assigned to a chronic aerobic training (Ex) (vs. sedentary group; Sed) and we investigated the role of eNOS in the effects of exercise on sensitivity to IR or anoxia-reoxygenation (A/R) at whole heart, isolated cardiomyocytes and left coronary artery (LCA) levels. We observed that exercise increased eNOS activation (Ser1177 phosphorylation) and protein S-nitrosylation in whole heart but not at cardiomyocyte level, suggesting the specific target of endothelial cells by exercise. Consistently, in isolated cardiomyocytes submitted to the A/R procedure, exercise reduced cell death and improved cells contractility, but independently of the eNOS pathway. Next, to evaluate the contribution of endothelial cells in exercise cardioprotection, LCA were isolated before and after an IR procedure performed on Langendorff hearts. Exercise improved basal relaxation sensitivity to acetylcholine and markedly reduced the alteration of endothelium-dependent coronary relaxation induced by IR. Furthermore, inactivation of coronary endothelial cells activity just before IR, obtained with a bolus of Triton X-100, totally suppressed cardioprotective effects of exercise on both left ventricular functional recovery after IR and infarct size, whereas no effect of Triton X-100 was observed in Sed group. In conclusion, these results show that coronary endothelial cells rather than cardiomyocytes play a key role in the eNOS-dependent cardioprotection of exercise.

  10. Is targeting eNOS a key mechanistic insight of cardiovascular defensive potentials of statins?

    PubMed

    Balakumar, Pitchai; Kathuria, Sonam; Taneja, Gaurav; Kalra, Sanjeev; Mahadevan, Nanjaian

    2012-01-01

    Statins are widely used in the treatment of dyslipidemia and associated cardiovascular abnormalities including atherosclerosis, hypertension and coronary heart disease. Needless to mention, statins have cholesterol-lowering effects by means of inhibiting 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase, a rate-limiting enzyme of cholesterol biosynthesis. Besides cholesterol-lowering effects, statins possess pleiotropic anti-inflammatory, anti-oxidant, anti-platelet and anti-fibrotic properties, which may additionally play imperative roles in statins-mediated cardiovascular protection. However, the precise mechanisms involved in the cardiovascular defensive potential of statins have not completely been elucidated. Intriguingly, a considerable number of studies demonstrated the potential modulatory role of statins on endothelial nitric oxide synthase (eNOS), a key enzyme involved in the regulation of cardiovascular function by generating endothelium-derived relaxing factor (often represented 'nitric oxide'). Worthy of note is that vascular generation of nitric oxide has beneficial anti-inflammatory, anti-platelet and vasodilatory actions. The upregulation of eNOS by statins is mediated through inhibition of synthesis of isoprenoids and subsequent prevention of isoprenylation of small GTPase Rho, whereas statin-induced activation of eNOS is mediated through activation of phosphotidylinositol-3-kinase (PI3K)/protein kinase B (PKB/Akt) signals. Additionally, statins enhance eNOS activation by abrogating caveolin-1 expression in vascular endothelium. In light of this view-point, we suggest in this review that eNOS upregulation and activation, in part, could play a fundamental role in the cardiovascular defensive potential of statins. The eNOS modulatory role of statins may have an imperative influence on the functional regulation of cardiovascular system and may offer new perspectives for the better use of statins in ameliorating cardiovascular disorders.

  11. Irisin improves endothelial function in obese mice through the AMPK-eNOS pathway.

    PubMed

    Han, Fang; Zhang, Shuxian; Hou, Ningning; Wang, Di; Sun, Xiaodong

    2015-11-01

    Irisin is a novel hormone secreted by myocytes. Lower levels of irisin are independently associated with endothelial dysfunction in obese subjects. The objective of this study was to explore whether irisin exerts a direct vascular protective effect on endothelial function in high-fat-diet-induced obese mice. Male C57BL/6 mice were given chow or a high-fat diet with or without treatment with irisin. Aortic endothelial function was determined by measuring endothelium-dependent vasodilatation (EDV). Nitric oxide (NO) in the aorta was determined. The effect of irisin on the levels of AMP-activated protein kinase (AMPK), Akt, and endothelial NO synthase (eNOS) phosphorylation in endothelial cells was determined. Human umbilical vein endothelial cells were used to study the role of irisin in the AMPK-eNOS pathway. Acetylcholine-stimulated EDV was significantly lower in obese mice compared with control mice. Treatment of obese mice with irisin significantly enhanced EDV and improved endothelial function. This beneficial effect of irisin was partly attenuated in the presence of inhibitors of AMPK, Akt, and eNOS. Treatment of obese mice with irisin enhanced NO production and phosphorylation of AMPK, Akt, and eNOS in endothelial cells. These factors were also enhanced by irisin in human umbilical vein endothelial cells in vitro. Suppression of AMPK expression by small interfering RNA blocked irisin-induced eNOS and Akt phosphorylation and NO production. We have provided the first evidence that irisin improves endothelial function in aortas of high-fat-diet-induced obese mice. The mechanism for this protective effect is related to the activation of the AMPK-eNOS signaling pathway.

  12. Ischemic preconditioning protects the brain against injury via inhibiting CaMKII-nNOS signaling pathway.

    PubMed

    Wang, Mei; Qi, Da-Shi; Zhou, Cui; Han, Dong; Li, Pei-Pei; Zhang, Fang; Zhou, Xiao-Yan; Han, Meng; Di, Jie-Hui; Ye, Jun-Song; Yu, Hong-Min; Song, Yuan-Jian; Zhang, Guang-Yi

    2016-03-01

    Although studies have shown that cerebral ischemic preconditioning (IPC) can ameliorate ischemia/reperfusion (I/R) induced brain damage, but its precise mechanisms remain unknown. Therefore, the aim of this study was to investigate the neuroprotective mechanisms of IPC against ischemic brain damage induced by cerebral I/R and to explore whether the Calcium/calmodulin-dependent protein kinase II (CaMKII)-mediated up-regulation of nNOS ser847-phosphorylation signaling pathway contributed to the protection provided by IPC. Transient global brain ischemia was induced by 4-vessel occlusion in adult male Sprague-Dawley rats. The rats were pretreated with 3 min of IPC alone or KN62 (selective antagonist of CaMKII) treatment before IPC, after reperfusion for 3 days, 6 min ischemia was induced. Cresyl violet staining was used to examine the survival of hippocampal CA1 pyramidal neurons. Immunoblotting was performed to measure the phosphorylation of CaMKII, nNOS, c-Jun and the expression of FasL. Immunoprecipitation was used to examine the binding between PSD95 and nNOS. The results showed that IPC could significantly protect neurons against cerebral I/R injury, furthermore, the combination of PSD95 and nNOS was increased, coinstantaneously the phosphorylation of CaMKII and nNOS (ser847) were up-regulated, however the activation of c-Jun and FasL were reduced. Conversely, KN62 treatment before IPC reversed all these effects of IPC. Taken together, the results suggest that IPC could diminish ischemic brain injury through CaMKII-mediated up-regulation of nNOS ser847-phosphorylation signaling pathway.

  13. Pregnancy increases myometrial artery myogenic tone via NOS- or COX-independent mechanisms.

    PubMed

    Eckman, Delrae M; Gupta, Ridhima; Rosenfeld, Charles R; Morgan, Timothy M; Charles, Shelton M; Mertz, Heather; Moore, Lorna G

    2012-08-15

    Myogenic tone (MT) is a primary modulator of blood flow in the resistance vasculature of the brain, kidney, skeletal muscle, and perhaps in other high-flow organs such as the pregnant uterus. MT is known to be regulated by endothelium-derived factors, including products of the nitric oxide synthase (NOS) and/or the cyclooxygenase (COX) pathways. We asked whether pregnancy influenced MT in myometrial arteries (MA), and if so, whether such an effect could be attributed to alterations in NOS and/or COX. MA (200-300 μm internal diameter, 2-3 mm length) were isolated from 10 nonpregnant and 12 pregnant women undergoing elective hysterectomy or cesarean section, respectively. In the absence of NOS and/or COX inhibition, pregnancy was associated with increased MT in endothelium-intact MA compared with MA from nonpregnant women (P < 0.01). The increase in MT was not due to increased Ca(2+) entry via voltage-dependent channels since both groups of MA exhibited similar levels of constriction when exposed to 50 mM KCl. NOS inhibition (N(ω)-nitro-L-arginine methyl ester, L-NAME) or combined NOS/COX inhibition (L-NAME/indomethacin) increased MT in MA from pregnant women (P = 0.001 and P = 0.042, respectively) but was without effect in arteries from nonpregnant women. Indomethacin alone was without effect on MT in MA from either nonpregnant or pregnant women. We concluded that MT increases in MA during human pregnancy and that this effect was partially opposed by enhanced NOS activity.

  14. Determining the chronology and components of psychosis onset: The Nottingham Onset Schedule (NOS).

    PubMed

    Singh, Swaran P; Cooper, John E; Fisher, Helen L; Tarrant, C Jane; Lloyd, Tuhina; Banjo, Jumi; Corfe, Sarah; Jones, Peter

    2005-12-01

    The Nottingham Onset Schedule (NOS) is a short, guided interview and rating schedule to measure onset in psychosis. Onset is defined as the time between the first reported/observed change in mental state/behaviour to the development of psychotic symptoms. Onset is conceptualised as comprising of (i) a prodrome of two parts: a period of 'unease' followed by 'non-diagnostic' symptoms; (ii) appearance of psychotic symptoms; and (iii) a build-up of diagnostic symptoms leading to a definite diagnosis. Twenty consecutive cases of first-episode psychosis were administered the NOS schedule to determine its psychometric properties including inter-rater and test-retest reliability. Its clinical and research potential as a reliable measure of duration of untreated psychosis (DUP) was assessed in a cohort of 99 cases of first-episode psychosis (56 schizophrenia, 43 affective psychoses). NOS identified all prodromal symptoms previously reported in other studies. There was high degree of inter-rater and test-retest reliability for all components of NOS. Duration of untreated psychosis was significantly longer (p<0.05) in schizophrenia (mean 179 days, S.D. 344; median 52 days) than in affective psychosis (mean 15 days, S.D. 116; median 12 days) but there were no gender differences between lengths of prodrome or treatment delays. The NOS provides a standardised and reliable way of recording early changes in psychosis and identifying relatively precise time points for measuring several durations in emerging psychosis. The scale is easy to use and is not time-consuming or labour intensive. Onset, as measured by NOS, is significantly longer in schizophrenic disorders than in affective psychosis. A small proportion of schizophrenia cases have very long DUP. Some cases with schizophrenia receive anti-psychotics in the prodromal phase, prior to the emergence of frank psychotic symptoms.

  15. Angiotensin II dependent cardiac remodeling in the eel Anguilla anguilla involves the NOS/NO system.

    PubMed

    Filice, Mariacristina; Amelio, Daniela; Garofalo, Filippo; David, Sabrina; Fucarino, Alberto; Jensen, Frank Bo; Imbrogno, Sandra; Cerra, Maria Carmela

    2017-05-01

    Angiotensin II (AngII), the principal effector of the Renin-Angiotensin System (RAS), plays an important role in controlling mammalian cardiac morpho-functional remodelling. In the eel Anguilla anguilla, one month administration of AngII improves cardiac performance and influences the expression and localization of molecules which regulate cell growth. To deeper investigate the morpho-functional chronic influences of AngII on the eel heart and the molecular mechanisms involved, freshwater eels (A. anguilla) were intraperitoneally injected for 2 months with AngII (1 nmol g BW(-1)). Then the isolated hearts were subjected to morphological and western blotting analyses, and nitrite measurements. If compared to control animals, the ventricle of AngII-treated hearts showed an increase in compacta thickness, vascularization, muscle mass and fibrosis. Structural changes were paralleled by a higher expression of AT2 receptor and a negative modulation of the ERK1-2 pathway, together with a decrease in nitrite concentration, indicative of a reduced Nitric Oxide Synthase (NOS)-dependent NO production. Moreover, immunolocalization revealed, particularly on the endocardial endothelium (EE) of AngII-treated hearts, a significant reduction of phosphorylated NOS detected by peNOS antibody accompanied by an increased expression of the eNOS disabling protein NOSTRIN, and a decreased expression of the positive regulators of NOS activity, pAkt and Hsp90. On the whole, results suggest that, in the eel, AngII modulates cardiac morpho-functional plasticity by influencing the molecular mechanisms that control NOS activity and the ERK1-2 pathway.

  16. Genetic variants of eNOS gene may modify the susceptibility to idiopathic male infertility.

    PubMed

    Ying, Hou-Qun; Pu, Xiao-Ying; Liu, Shuo-Ran; A, Zhou-Cun

    2013-08-01

    In testis, eNOS is responsible for synthesis of nitric oxide (NO) which is an essential gas message regulator in spermatogenesis, suggesting that eNOS gene plays a role in normal spermatogenesis and the genetic variants of eNOS gene may be potential genetic risk factors of spermatogenesis impairment. In this study, the polymorphic distributions of three common polymorphism loci including T-786C, 4A4B and G894T in eNOS gene were investigated in 355 Chinese infertile patients with azoospermia or oligozoospermia and 246 healthy fertile men and a meta-analysis was carried in order to explore the possible relationship between the three loci of eNOS gene and male infertility with spermatogenesis impairment. As a result, allele -786C of T-786C (11.4% versus 6.5%, p = 0.004) and 4A of 4A4B (11.0% versus 6.3%, p = 0.005) as well as genotype TC of T-786C (22.8% versus 13.0%, p = 0.002) and AB of 4A4B (18% versus 11%, p = 0.015) were significantly associated with idiopathic male infertility. The haplotypes T-4A-G (7.4% versus 4.1%, p = 0.015) and C-4B-G (7.6% versus 4.4%, p = 0.028) could increase the susceptibility to male infertility, whereas haplotype T-4B-G (67.0% versus 75.2%, p = 0.002) might be a protective factor for male infertility. The results of meta-analysis revealed that the polymorphism of T-786C was associated with male infertility. These findings suggested that the variants of eNOS gene may modify the susceptibility to male infertility with impaired spermatogenesis.

  17. The Nature of Natural Hazards Communication (Invited)

    NASA Astrophysics Data System (ADS)

    Kontar, Y. Y.

    2013-12-01

    Some of the many issues of interest to natural hazards professionals include the analysis of proactive approaches to the governance of risk from natural hazards and approaches to broaden the scope of public policies related to the management of risks from natural hazards, as well as including emergency and environmental management, community development and spatial planning related to natural hazards. During the talk we will present results of scientific review, analysis and synthesis, which emphasize same new trends in communication of the natural hazards theories and practices within an up-to-the-minute context of new environmental and climate change issues, new technologies, and a new focus on resiliency. The presentation is divided into five sections that focus on natural hazards communication in terms of education, risk management, public discourse, engaging the public, theoretical perspectives, and new media. It includes results of case studies and best practices. It delves into natural hazards communication theories, including diffusion, argumentation, and constructivism, to name a few. The presentation will provide information about: (1) A manual of natural hazards communication for scientists, policymakers, and media; (2) An up-to-the-minute context of environmental hazards, new technologies & political landscape; (3) A work by natural hazards scientists for geoscientists working with social scientists and communication principles; (4) A work underpinned by key natural hazards communication theories and interspersed with pragmatic solutions; (5) A work that crosses traditional natural hazards boundaries: international, interdisciplinary, theoretical/applied. We will further explore how spatial planning can contribute to risk governance by influencing the occupation of natural hazard-prone areas, and review the central role of emergency management in risk policy. The goal of this presentation is to contribute to the augmentation of the conceptual framework

  18. Small molecule inhibitors of PSD95-nNOS protein-protein interactions as novel analgesics

    PubMed Central

    Lee, Wan-Hung; Xu, Zhili; Ashpole, Nicole M.; Hudmon, Andy; Kulkarni, Pushkar M.; Thakur, Ganesh A.; Lai, Yvonne Y.; Hohmann, Andrea G.

    2015-01-01

    Aberrant increases in NMDA receptor (NMDAR) signaling contributes to central nervous system sensitization and chronic pain by activating neuronal nitric oxide synthase (nNOS) and generating nitric oxide (NO). Because the scaffolding protein postsynaptic density 95kDA (PSD95) tethers nNOS to NMDARs, the PSD95-nNOS complex represents a therapeutic target. Small molecule inhibitors IC87201 (EC5O: 23.94 µM) and ZL006 (EC50: 12.88 µM) directly inhibited binding of purified PSD95 and nNOS proteins in AlphaScreen without altering binding of PSD95 to ErbB4. Both PSD95-nNOS inhibitors suppressed glutamate-induced cell death with efficacy comparable to MK-801. IC87201 and ZL006 preferentially suppressed phase 2A pain behavior in the formalin test and suppressed allodynia induced by intraplantar complete Freund’s adjuvant administration. IC87201 and ZL006 suppressed mechanical and cold allodynia induced by the chemotherapeutic agent paclitaxel (ED50s: 2.47 and 0.93 mg/kg i.p. for IC87201 and ZL006, respectively). Efficacy of PSD95-nNOS disruptors was similar to MK-801. Motor ataxic effects were induced by MK-801 but not by ZL006 or IC87201. Finally, MK-801 produced hyperalgesia in the tail-flick test whereas IC87201 and ZL006 did not alter basal nociceptive thresholds. Our studies establish the utility of using AlphaScreen and purified protein pairs to establish and quantify disruption of protein-protein interactions. Our results demonstrate previously unrecognized antinociceptive efficacy of ZL006 and establish, using two small molecules, a broad application for PSD95-nNOS inhibitors in treating neuropathic and inflammatory pain. Collectively, our results demonstrate that disrupting PSD95-nNOS protein-protein interactions is effective in attenuating pathological pain without producing unwanted side effects (i.e. motor ataxia) associated with NMDAR antagonists. PMID:26071110

  19. Catalytic Promiscuity of the Radical S-adenosyl-L-methionine Enzyme NosL

    PubMed Central

    Ding, Wei; Ji, Xinjian; Li, Yongzhen; Zhang, Qi

    2016-01-01

    Catalytic promiscuity plays a key role in enzyme evolution and the acquisition of novel biological functions. Because of the high reactivity of radical species, in our view enzymes involving radical-mediated mechanisms could intrinsically be more prone to catalytic promiscuity. This mini-review summarizes the recent advances in the study of NosL, a radical S-adenosyl-L-methionine (SAM)-dependent L-tryptophan (L-Trp) lyase. We demonstrate here the interesting chemistry and remarkable catalytic promiscuity of NosL, and attempt to highlight the high evolvability of radical SAM enzymes and the potential to engineer these enzymes for novel and improved activities. PMID:27446906

  20. A vast amount of various invariant tori in the Nosé-Hoover oscillator

    SciTech Connect

    Wang, Lei; Yang, Xiao-Song

    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.

  1. Increased activity and expression of Ca2+-dependent NOS in renal cortex of ANG II-infused hypertensive rats

    PubMed Central

    CHIN, SO YEON; PANDEY, KAILASH N.; SHI, SHANG-JIN; KOBORI, HIROYUKI; MORENO, CAROL; NAVAR, L. GABRIEL

    2008-01-01

    We have previously demonstrated that nitric oxide (NO) exerts a greater modulatory influence on renal cortical blood flow in ANG II-infused hypertensive rats compared with normotensive rats. In the present study, we determined nitric oxide synthase (NOS) activities and protein levels in the renal cortex and medulla of normotensive and ANG II-infused hypertensive rats. Enzyme activity was determined by measuring the rate of formation of l-[14C]citrulline from l-[14C]arginine. Western blot analysis was performed to determine the regional expression of endothelial (eNOS), neuronal (nNOS), and inducible (iNOS) isoforms in the renal cortex and medulla of control and ANG II-infused rats. Male Sprague-Dawley rats were prepared by the infusion of ANG II at a rate of 65 ng/min via osmotic minipumps implanted subcutaneously for 13 days and compared with sham-operated rats. Systolic arterial pressures were 127 ± 2 and 182 ± 3 mmHg in control (n = 13) and ANG II-infused rats (n = 13), respectively. The Ca2+-dependent NOS activity, expressed as picomoles of citrulline formed per minute per gram wet weight, was higher in the renal cortex of ANG II-infused rats (91 ± 11) than in control rats (42 ± 12). Likewise, both eNOS and nNOS were markedly elevated in the renal cortex of the ANG II-treated rats. In both groups of rats, Ca2+-dependent NOS activity was higher in the renal medulla than in the cortex; however, no differences in medullary NOS activity were observed between the groups. Also, no differences in medullary eNOS levels were observed between the groups; however, medullary nNOS was decreased by 45% in the ANG II-infused rats. For the Ca2+-independent NOS activities, the renal cortex exhibited a greater activity in the control rats (174 ± 23) than in ANG II-infused rats (101 ± 10). Similarly, cortical iNOS was greater by 47% in the control rats than in ANG II-treated rats. No differences in the activity were found for the renal medulla between the groups. There was

  2. Co-expression of GAP-43 and nNOS in avulsed motoneurons and their potential role for motoneuron regeneration.

    PubMed

    Yuan, Qiuju; Hu, Bing; Chu, Tak-Ho; Su, Huanxing; Zhang, Wenming; So, Kwok-Fai; Lin, Zhixiu; Wu, Wutian

    2010-12-15

    Neuronal nitric oxide synthase (nNOS) is induced after axonal injury. The role of induced nNOS in injured neurons is not well established. In the present study, we investigated the co-expression of nNOS with GAP-43 in spinal motoneurons following axonal injury. The role of induced nNOS was discussed and evaluated. In normal rats, spinal motoneurons do not express nNOS or GAP-43. Following spinal root avulsion, expression of nNOS and GAP-43 were induced and colocalized in avulsed motoneurons. Reimplantation of avulsed roots resulted in a remarkable decrease of GAP-43- and nNOS-IR in the soma of the injured motoneurons. A number of GAP-43-IR regenerating motor axons were found in the reimplanted nerve. In contrast, the nNOS-IR was absent in reimplanted nerve. These results suggest that expression of GAP-43 in avulsed motoneurons is related to axonal regeneration whereas nNOS is not.

  3. 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

  4. 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.

  5. Teaching the Nature of Science Through the Millikan-Ehrenhaft Dispute

    NASA Astrophysics Data System (ADS)

    Paraskevopoulou, Eleni; Koliopoulos, Dimitris

    2011-10-01

    This article presents the results of a research project that investigated the extent to which the use of the historical episode of the Millikan-Ehrenhaft dispute over the existence of the elementary electric charge can improve students' conceptions of specific aspects of the Nature of Science (NOS). A teaching programme containing seven hourly teaching units was designed and implemented. The teaching intervention was designed on the basis of an explicit form of teaching that was integrated into the scientific content and through the use of short stories. Students' conceptions of specific aspects of NOS were documented in a questionnaire distributed before and after the class. The results showed that there was a significant statistical improvement in students' conceptions of the aspects of NOS that had been selected for teaching.

  6. Putting Sociology First—Reconsidering the Role of the Social in `Nature of Science' Education

    NASA Astrophysics Data System (ADS)

    Zemplén, Gábor Á.

    2009-05-01

    Contrasting two examples from 2005, a creationism-trial and a recent textbook, the article shows two different ways of employing social considerations to demarcate science from non-science. Drawing conclusions from the comparison, and citing some of the leading proponents of science studies, the paper argues for a novel perspective in teaching nature of science (NOS) issues, one that grows out of sociological and anthropological considerations of (scientific) expertise. In contrast to currently dominant epistemic approaches to teach NOS, this view makes it possible to incorporate epistemic and social norms in a unified framework that can alleviate presently problematic aspects of NOS modules, and can help students appreciate science as a privileged form of knowledge-production without becoming scientistic. A pilot module to carry out the above is presented and assessed, showing that a broad sociological starting point is closer to the lifeworld of students, and that traditional epistemic considerations need not be compromised.

  7. 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.

  8. 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

  9. Anti-inflammatory effects of flavonoids: genistein, kaempferol, quercetin, and daidzein inhibit STAT-1 and NF-kappaB activations, whereas flavone, isorhamnetin, naringenin, and pelargonidin inhibit only NF-kappaB activation along with their inhibitory effect on iNOS expression and NO production in activated macrophages.

    PubMed

    Hämäläinen, Mari; Nieminen, Riina; Vuorela, Pia; Heinonen, Marina; Moilanen, Eeva

    2007-01-01

    In inflammation, bacterial products and proinflammatory cytokines induce the formation of large amounts of nitric oxide (NO) by inducible nitric oxide synthase (iNOS), and compounds that inhibit NO production have anti-inflammatory effects. In the present study, we systematically investigated the effects of 36 naturally occurring flavonoids and related compounds on NO production in macrophages exposed to an inflammatory stimulus (lipopolysaccharide, LPS), and evaluated the mechanisms of action of the effective compounds. Flavone, the isoflavones daidzein and genistein, the flavonols isorhamnetin, kaempferol and quercetin, the flavanone naringenin, and the anthocyanin pelargonidin inhibited iNOS protein and mRNA expression and also NO production in a dose-dependent manner. All eight active compounds inhibited the activation of nuclear factor-kappaB (NF-kappaB), which is a significant transcription factor for iNOS. Genistein, kaempferol, quercetin, and daidzein also inhibited the activation of the signal transducer and activator of transcription 1 (STAT-1), another important transcription factor for iNOS. The present study characterises the effects and mechanisms of naturally occurring phenolic compounds on iNOS expression and NO production in activated macrophages. The results partially explain the pharmacological efficacy of flavonoids as anti-inflammatory compounds.

  10. 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

  11. A Natural Love of Natural Products

    PubMed Central

    2008-01-01

    Recent research on the chemistry of natural products from the author’s group that led to the receipt of the ACS Ernest Guenther Award in the Chemistry of Natural Products is reviewed. REDOR NMR and synthetic studies established the T-taxol conformation as the bioactive tubulin-binding conformation, and these results were confirmed by the synthesis of compounds which clearly owed their activity or lack of activity to whether or not they could adopt the T-taxol conformation. Similar studies with the epothilones suggest that the current tubulin-binding model needs to be modified. Examples of natural products discovery and biodiversity conservation in Suriname and Madagascar are also presented, and it is concluded that natural products chemistry will continue to make significant contributions to drug discovery. PMID:18459734

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

    NASA Astrophysics Data System (ADS)

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

    2014-08-01

    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 education were analyzed to describe NOS content included as well as the historical experiments and narratives used. Based on the results of descriptive content analysis of existing curriculum materials, several suggestions on the successful design of lesson plans utilizing historical approach are made. To increase the coherence and clarity of learning objectives and instruction, each lesson plan should focus on the limited amount of specific NOS issues instead of several overtly general NOS aspects. To support explicit classroom discussion on the selected NOS issues, historical narratives used in the lesson plans should illustrate these issues. The lesson plans should also include instructions on how to facilitate classroom discussion, such as questions for students to discuss and reflect. Recommendations are also made concerning the appropriate use of historical experiments and narrative elements such as viewpoint characters and conflicts.

  13. 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.

  14. 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.

  15. 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.

  16. Protective effect of eNOS overexpression against ischemia/reperfusion injury in small-for-size liver transplantation

    PubMed Central

    Zhang, Bo; Liu, Qiu-Hua; Zhou, Cui-Jie; Hu, Ming-Zheng; Qian, Hai-Xin

    2016-01-01

    Ischemia/reperfusion (I/R) injury can occur during small-for-size liver transplantation, resulting in delayed graft function and decreased long-term graft survival. The aim of the present study was to evaluate the effects of genetic overexpression of endothelial nitric oxide synthase (eNOS) in protecting hepatocytes against I/R injury in a rat model of small-for-size liver transplantation. L02 liver cells were transfected with the eNOS gene using an adenovirus (Ad-eNOS). eNOS expression was detected using quantitative polymerase chain reaction and western blot analysis. To evaluate the effect of eNOS overexpression, L02 cells were placed in a hypoxic environment for 12 h and immediately transferred to an oxygen-enriched atmosphere. For in vivo testing, rats pretreated with Ad-eNOS or control underwent small-for-size liver transplantation. At 6 h after reperfusion, the bile quantity, serum transaminase and nitric oxide (NO) levels, and histological outcomes were evaluated. Cell apoptosis was assessed by flow cytometry or TUNEL assay. In vitro, Ad-eNOS prevented apoptosis in L02 cells with an increase in the level of NO in culture supernatant. In vivo, Ad-eNOS pre-treatment significantly increased bile production, improved abnormal transaminase levels, diminished apoptosis among liver cells, and decreased hepatocellular damage at 6 h after I/R injury. The eNOS-mediated renal protective effects might be associated with the downregulation of tumor necrosis factor-α and a reduction in macrophage activation in the early stage of reperfusion in small-for-size liver allografts. eNOS-derived NO production significantly attenuates hepatic I/R injury. Thus, eNOS overexpression constitutes a promising therapeutic approach to prevent liver I/R injury following small-for-size liver transplantation. PMID:27882135

  17. Carbon monoxide increases inducible NOS expression that mediates CO-induced myocardial damage during ischemia-reperfusion.

    PubMed

    Meyer, Grégory; André, Lucas; Kleindienst, Adrien; Singh, François; Tanguy, Stéphane; Richard, Sylvain; Obert, Philippe; Boucher, François; Jover, Bernard; Cazorla, Olivier; Reboul, Cyril

    2015-04-01

    We investigated the role of inducible nitric oxide (NO) synthase (iNOS) on ischemic myocardial damage in rats exposed to daily low nontoxic levels of carbon monoxide (CO). CO is a ubiquitous environmental pollutant that impacts on mortality and morbidity from cardiovascular diseases. We have previously shown that CO exposure aggravates myocardial ischemia-reperfusion (I/R) injury partly because of increased oxidative stress. Nevertheless, cellular mechanisms underlying cardiac CO toxicity remain hypothetical. Wistar rats were exposed to simulated urban CO pollution for 4 wk. First, the effects of CO exposure on NO production and NO synthase (NOS) expression were evaluated. Myocardial I/R was performed on isolated perfused hearts in the presence or absence of S-methyl-isothiourea (1 μM), a NOS inhibitor highly specific for iNOS. Finally, Ca(2+) handling was evaluated in isolated myocytes before and after an anoxia-reoxygenation performed with or without S-methyl-isothiourea or N-acetylcystein (20 μM), a nonspecific antioxidant. Our main results revealed that 1) CO exposure altered the pattern of NOS expression, which is characterized by increased neuronal NOS and iNOS expression; 2) cardiac NO production increased in CO rats because of its overexpression of iNOS; and 3) the use of a specific inhibitor of iNOS reduced myocardial hypersensitivity to I/R (infarct size, 29 vs. 51% of risk zone) in CO rat hearts. These last results are explained by the deleterious effects of NO and reactive oxygen species overproduction by iNOS on diastolic Ca(2+) overload and myofilaments Ca(2+) sensitivity. In conclusion, this study highlights the involvement of iNOS overexpression in the pathogenesis of simulated urban CO air pollution exposure.

  18. Deficient eNOS phosphorylation is a mechanism for diabetic vascular dysfunction contributing to increased stroke size

    PubMed Central

    Li, Qian; Atochin, Dmitriy; Kashiwagi, Satoshi; Earle, John; Wang, Annie; Mandeville, Emiri; Hayakawa, Kazuhide; d'Uscio, Livius V.; Lo, Eng H.; Katusic, Zvonimir; Sessa, William; Huang, Paul

    2013-01-01

    Background and Purpose Phosphorylation of eNOS, an important post-translational modulator of its enzymatic activity, is reduced in diabetes. We hypothesized that modulation of eNOS phosphorylation could overcome diabetic vascular dysfunction and improves the outcome to stroke. Methods We used the db/db mouse model of type 2 diabetes. We mated db/db mice with eNOS knockin mice that carry single-amino acid mutations at the S1176 phosphorylation site; the phosphomimetic SD mutation shows increased eNOS enzymatic activity, while the unphosphorylatable SA mutation shows decreased eNOS activity. We characterized the vascular anatomy, baseline physiologic parameters and vascular reactivity. We used the middle cerebral artery occlusion model of stroke and measured infarct volume and neurological deficits. Results db/db mice showed diminished eNOS phosphorylation at S1176. eNOS SD and SA mutations do not change the vascular anatomy at the Circle of Willis, brain capillary density, heart rate, or arterial blood gases of db/db mice. The eNOS SD mutation, but not the SA mutation, lowers blood pressure and improves vascular reactivity to acetylcholine in db/db mice. The eNOS SD mutation reduces stroke size and neurologic deficit following middle cerebral artery occlusion. Conclusion Diminished eNOS phosphorylation is a mechanism of vascular dysfunction in db/db mice. We show here that modulation of the eNOS S1176 phosphorylation site in db/db mice is associated with improved vascular reactivity and improved outcome to stroke following middle cerebral artery occlusion. PMID:23988642

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

    PubMed Central

    Harvey, Richard; Phung, Dinh; Venkatesh, Svetha; Connor, Jason P

    2016-01-01

    Objectives 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. Setting A regional mental health service with both acute and community facilities. Participants 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. Primary and secondary outcome measures The difference of HoNOS at inpatient-discharge and community-intake were assessed with Pearson correlation, Cohen's κ and effect size. Results 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. Conclusions 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. PMID:27121703

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

    PubMed

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

    2013-09-01

    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.

  1. Nature's Nature: Ideas of Nature in Curricula for Environmental Education

    ERIC Educational Resources Information Center

    St Maurice, Henry

    2006-01-01

    Two contrasting sets of ideas about nature in environmental education are described. An analytical framework is developed from inter-disciplinary histories of ideas and used in evaluating a specific curriculum. In conclusion, some general implications are suggested for curricula in environmental education. [This article was reprinted from…

  2. Site overview. Part 2 of 3part panorama with nos. CA27021 ...

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

    Site overview. Part 2 of 3-part panorama with nos. CA-2702-1 and CA-2707-3. Hanger no. 2 at left rear. Hangar no. 1 at right rear. Hangar no. 1 landing pad road in center. Looking 232 SW. - Marine Corps Air Station Tustin, East of Red Hill Avenue between Edinger Avenue & Barranca Parkway, Tustin, Orange County, CA

  3. Site overview. Part 3 of 3part panorama with nos. CA27071 ...

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

    Site overview. Part 3 of 3-part panorama with nos. CA2707-1 and CA-2707-2. Hangar no. 1. Seen from roadway leading to hangar no. 1 landing pad. Looking 250 WSW. - Marine Corps Air Station Tustin, Northern Lighter Than Air Ship Hangar, Meffett Avenue & Maxfield Street, Tustin, Orange County, CA

  4. Site overview. Part 3 of 3part panorama with nos. CA27071 ...

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

    Site overview. Part 3 of 3-part panorama with nos. CA2707-1 and CA-2707-2. Hangar no. 1. Seen from roadway leading to hangar no. 1 landing pad. Looking 250 WSW. - Marine Corps Air Station Tustin, East of Red Hill Avenue between Edinger Avenue & Barranca Parkway, Tustin, Orange County, CA

  5. 4. PART 1 OF 3 PART PANORAMA WITH NOS. CA265J5 ...

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

    4. PART 1 OF 3 PART PANORAMA WITH NOS. CA-265-J-5 AND CA-265-J-6 OF FIGUEROA STREET AND LOS ANGELES RIVER VIADUCTS. NOTE TUNNEL NO.1 NORTH PORTAL AT LEFT REAR. LOOKING 268°W. - Arroyo Seco Parkway, Figueroa Street Viaduct, Spanning Los Angeles River, Los Angeles, Los Angeles County, CA

  6. Site overview. Part 2 of 3part panorama with nos. CA27021 ...

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

    Site overview. Part 2 of 3-part panorama with nos. CA-2702-1 and CA-2707-3. Hanger no. 2 at left rear. Hangar no. 1 at right rear. Hangar no. 1 landing pad road in center. Looking 232 SW. - Marine Corps Air Station Tustin, Northern Lighter Than Air Ship Hangar, Meffett Avenue & Maxfield Street, Tustin, Orange County, CA

  7. 5. PART 2 OF 3 PART PANORAMA WITH NOS. CA265J4 ...

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

    5. PART 2 OF 3 PART PANORAMA WITH NOS. CA-265-J-4 AND CA-265-J-6 OF FIGUEROA STREET AND LOS ANGELES RIVER VIADUCTS. LOOKING 308°W. - Arroyo Seco Parkway, Figueroa Street Viaduct, Spanning Los Angeles River, Los Angeles, Los Angeles County, CA

  8. 30. BUILDING NO.S 271K AND 271L, VIEW LOOKING SOUTH AT ...

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

    30. BUILDING NO.S 271-K AND 271-L, VIEW LOOKING SOUTH AT BACK OF BUILDING NO. 271-L (LEFT), 271-K (MIDDLE) AND ROOF OF BUILDING NO. 271-I (VISIBLE OVER WALKWAY ON RIGHT). - Picatinny Arsenal, 200 Area, Shell Component Loading, State Route 15 near I-80, Dover, Morris County, NJ

  9. 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.

  10. Neuronal nitric oxide synthase (NOS1) polymorphisms interact with financial hardship to affect depression risk.

    PubMed

    Sarginson, Jane E; Deakin, J F William; Anderson, Ian M; Downey, Darragh; Thomas, Emma; Elliott, Rebecca; Juhasz, Gabriella

    2014-11-01

    There is increasing evidence that genetic factors have a role in differential susceptibility to depression in response to severe or chronic adversity. Studies in animals suggest that nitric oxide (NO) signalling has a key role in depression-like behavioural responses to stress. This study investigated whether genetic variation in the brain-expressed nitric oxide synthase gene NOS1 modifies the relationship between psychosocial stress and current depression score. We recruited a population sample of 1222 individuals who provided DNA and questionnaire data on symptoms and stress. Scores on the List of Life-Threatening Experiences (LTE) questionnaire for the last year and self-rated current financial hardship were used as measures of recent/ongoing psychosocial stress. Twenty SNPs were genotyped. Significant associations between eight NOS1 SNPs, comprising two regional haplotypes, and current depression score were identified that survived correction for multiple testing when current financial hardship was used as the interaction term. A smaller three-SNP haplotypes (rs10507279, rs1004356 and rs3782218) located in a regulatory region of NOS1 showed one of the strongest effects, with the A-C-T haplotype associating with higher depression scores at low adversity levels but lower depression scores at higher adversity levels (p=2.3E-05). These results suggest that NOS1 SNPs interact with exposure to economic and psychosocial stressors to alter individual's susceptibility to depression.

  11. 6. PART 3 OF 3 PART PANORAMA WITH NOS. CA265J4 ...

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

    6. PART 3 OF 3 PART PANORAMA WITH NOS. CA-265-J-4 AND CA-265-J-5 OF FIGUEROA STREET AND LOS ANGELES RIVER VIADUCTS. NOTE ARROYO SECO CHANNEL ENTERING LOS ANGELES RIVER UNDER RAILROAD TRESTLE AT RIGHT. LOOKING 268°W. - Arroyo Seco Parkway, Figueroa Street Viaduct, Spanning Los Angeles River, Los Angeles, Los Angeles County, CA

  12. 32. LOOKING NORTHEAST DOWN WALKWAY CONNECTING BUILDING NO.S 271, 271G, ...

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

    32. LOOKING NORTHEAST DOWN WALKWAY CONNECTING BUILDING NO.S 271, 271-G, 271-I, 271-L, 271-K, ETC. MIRRORS IN UPPER RIGHT PERMIT WORKERS TO SEE AROUND CORNER TO CORRIDOR LEADING TO BUILDING NO. 271-H (LEAD AZIDE PREPARATION BUILDING). - Picatinny Arsenal, 200 Area, Shell Component Loading, State Route 15 near I-80, Dover, Morris County, NJ

  13. Fluctuation theorem applied to the Nosé-Hoover thermostated Lorentz gas.

    PubMed

    Gilbert, Thomas

    2006-03-01

    We present numerical evidence supporting the validity of the Gallavotti-Cohen fluctuation theorem applied to the driven Lorentz gas with Nosé-Hoover thermostating. It is moreover argued that the asymptotic form of the fluctuation formula is independent of the amplitude of the driving force in the limit where it is small.

  14. Fluctuation theorem applied to the Nosé-Hoover thermostated Lorentz gas

    NASA Astrophysics Data System (ADS)

    Gilbert, Thomas

    2006-03-01

    We present numerical evidence supporting the validity of the Gallavotti-Cohen fluctuation theorem applied to the driven Lorentz gas with Nosé-Hoover thermostating. It is moreover argued that the asymptotic form of the fluctuation formula is independent of the amplitude of the driving force in the limit where it is small.

  15. 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.

  16. Burkholderia pseudomallei rpoS mediates iNOS suppression in human hepatocyte (HC04) cells

    PubMed Central

    Sanongkiet, Sucharat; Ponnikorn, Saranyoo; Udomsangpetch, Rachanee; Tungpradabkul, Sumalee

    2016-01-01

    Burkholderia pseudomallei is an intracellular Gram-negative bacterial pathogen and the causative agent of melioidosis, a widespread disease in Southeast Asia. Reactive nitrogen, in an intermediate form of nitric oxide (NO), is one of the first lines of defense used by host cells to eliminate intracellular pathogens, through the stimulation of inducible nitric oxide synthase (iNOS). Studies in phagocytotic cells have shown that the iNOS response is muted in B. pseudomallei infection, and implicated the rpoS sigma factor as a key regulatory factor mediating suppression. The liver is a main visceral organ affected by B. pseudomallei, and there is little knowledge about the interaction of liver cells and B. pseudomallei. This study investigated the induction of iNOS, as well as autophagic flux and light-chain 3 (LC3) localization in human liver (HC04) cells in response to infection with B. pseudomallei and its rpoS deficient mutant. Results showed that the rpoS mutant was unable to suppress iNOS induction and that the mutant showed less induction of autophagy and lower co-localization with LC3, and this was coupled with a lower intracellular growth rate. Combining these results suggest that B. pseudomallei rpoS is an important factor in establishing infection in liver cells. PMID:27324398

  17. Role of iNOS in Bystander Signaling Between Macrophages and Lymphoma Cells

    SciTech Connect

    Ghosh, Somnath; Maurya, Dharmendra Kumar; Krishna, Malini

    2008-12-01

    Purpose: The present report describes the bystander effects of radiation between similar and dissimilar cells and the role of iNOS in such communication. Materials and Methods: EL-4 and RAW 264.7 cells were exposed to 5 Gy {gamma}-irradiation. The medium from irradiated cells was transferred to unirradiated cells. Results: Irradiated EL-4 cells as well as those cultured in the presence of medium from {gamma}-irradiated EL-4 cells showed an upregulation of NF-{kappa}B, iNOS, p53, and p21/waf1 genes. The directly irradiated and the bystander EL-4 cells showed an increase in DNA damage, apoptosis, and NO production. Bystander signaling was also found to exist between RAW 264.7 (macrophage) and EL-4 (lymphoma) cells. Unstimulated or irradiated RAW 264.7 cells did not induce bystander effect in unirradiated EL-4 cells, but LPS stimulated and irradiated RAW 264.7 cells induced an upregulation of NF-{kappa}B and iNOS genes and increased the DNA damage in bystander EL-4 cells. Treatment of EL-4 or RAW 264.7 cells with L-NAME significantly reduced the induction of gene expression and DNA damage in the bystander EL-4 cells, whereas treatment with cPTIO only partially reduced the induction of gene expression and DNA damage in the bystander EL-4 cells. Conclusions: It was concluded that active iNOS in the irradiated cells was essential for bystander response.

  18. Effects of PRRSV infection on TLR-dependent induction of NOS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Inducible nitric oxide synthase (iNOS) is an important effector enzyme in the macrophage arsenal against pathogens. This enzyme is produced in response to bacterial cell wall components such as lipopolysaccharide (LPS) and dsRNA--a by-product of viral replication, binding to Toll-like receptors (TL...

  19. eNOS-Dependent Antisenscence Effect of a Calcium Channel Blocker in Human Endothelial Cells

    PubMed Central

    Hayashi, Toshio; Yamaguchi, Tomoe; Sakakibara, Yasufumi; Taguchi, Kumiko; Maeda, Morihiko; Kuzuya, Masafumi; Hattori, Yuichi

    2014-01-01

    Senescence of vascular endothelial cells is an important contributor to the pathogenesis of age-associated vascular disorders such as atherosclerosis. We investigated the effects of antihypertensive agents on high glucose-induced cellular senescence in human umbilical venous endothelial cells (HUVECs). Exposure of HUVECs to high glucose (22 mM) for 3 days increased senescence-associated- β-galactosidase (SA-β-gal) activity, a senescence marker, and decreased telomerase activity, a replicative senescence marker. The calcium channel blocker nifedipine, but not the β1-adrenergic blocking agent atenolol or the angiotensin-converting enzyme inhibitor perindopril, reduced SA-β-gal positive cells and prevented a decrease in telomerase activity in a high-glucose environment. This beneficial effect of nifedipine was associated with reduced reactive oxygen species (ROS) and increased endothelial nitric oxide synthase (eNOS) activity. Thus, nifedipine prevented high glucose-induced ROS generation and increased basal eNOS phosphorylation level at Ser-1177. Treatment with NG-nitro-L-arginine (L-NAME) and transfection of small interfering RNA (siRNA) targeting eNOS eliminated the anti-senscence effect of nifedipine. These results demonstrate that nifedipine can prevent endothelial cell senescence in an eNOS-dependent manner. The anti-senescence action of nifedipine may represent a novel mechanism by which it protects against atherosclerosis. PMID:24520379

  20. 49 CFR 173.335 - Chemical under pressure n.o.s.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... internal pressure at 65 °C (149 °F) must not exceed the test pressure of the cylinder. The vapor pressures... 49 Transportation 2 2014-10-01 2014-10-01 false Chemical under pressure n.o.s. 173.335 Section 173... REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS Gases; Preparation and Packaging § 173.335 Chemical under pressure...

  1. Using Video Modeling to Teach Children with PDD-NOS to Respond to Facial Expressions

    ERIC Educational Resources Information Center

    Axe, Judah B.; Evans, Christine J.

    2012-01-01

    Children with autism spectrum disorders often exhibit delays in responding to facial expressions, and few studies have examined teaching responding to subtle facial expressions to this population. We used video modeling to train 3 participants with PDD-NOS (age 5) to respond to eight facial expressions: approval, bored, calming, disapproval,…

  2. Impairments in Fear Conditioning in Mice Lacking the nNOS Gene

    ERIC Educational Resources Information Center

    Kelley, Jonathan B.; Balda, Mara A.; Anderson, Karen L.; Itzhak, Yossef

    2009-01-01

    The fear conditioning paradigm is used to investigate the roles of various genes, neurotransmitters, and substrates in the formation of fear learning related to contextual and auditory cues. In the brain, nitric oxide (NO) produced by neuronal nitric oxide synthase (nNOS) functions as a retrograde neuronal messenger that facilitates synaptic…

  3. Current Status of Intensive Behavioral Interventions for Young Children with Autism and PDD-NOS

    ERIC Educational Resources Information Center

    Matson, Johnny L.; Smith, Kimberly R. M.

    2008-01-01

    The development of learning based interventions has proven to be an effective means of remediating symptoms of autism and PDD-NOS. The central focus of these effects in recent years has been on early intensive behavioral interventions (EIBI) with preschool children. We use the term EIBI since it is the most often used, and we assume, preferred…

  4. 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

  5. Demonstrating Natural Selection

    ERIC Educational Resources Information Center

    Hinds, David S.; Amundson, John C.

    1975-01-01

    Describes laboratory exercises with chickens selecting their food from dyed and natural corn kernels as a method of demonstrating natural selection. The procedure is based on the fact that organisms that blend into their surroundings escape predation. (BR)

  6. Natural Gas Monthly

    EIA Publications

    2017-01-01

    Highlights activities, events, and analyses associated with the natural gas industry. Volume and price data are presented each month for natural gas production, distribution, consumption, and interstate pipeline activities. Producer related activities and underground storage data are also reported.

  7. Natural gas annual 1996

    SciTech Connect

    1997-09-01

    This document provides information on the supply and disposition of natural gas to a wide audience. The 1996 data are presented in a sequence that follows natural gas from it`s production to it`s end use.

  8. Fine Arts through Nature.

    ERIC Educational Resources Information Center

    Gentry, Carol

    1986-01-01

    Describes how high school students are involved in using natural materials found in the local environment for art projects. The materials used include wood, clay, and natural fibers. Provides photographs of ten students' projects. (JDH)

  9. Colours From Nature

    ERIC Educational Resources Information Center

    Simon, Wilma

    1974-01-01

    In reference to American Indian ceremonial art, the importance of using natural pigments is emphasized, since the superior color values of natural dyes better reflect religious and philosophical depth and meaning. (JC)

  10. Natural gas annual 1994

    SciTech Connect

    1995-11-17

    The Natural Gas Annual provides information on the supply and disposition of natural gas to a wide audience including industry, consumers, Federal and State agencies, and educational institutions. The 1994 data are presented in a sequence that follows natural gas (including supplemental supplies) from its production to its end use. This is followed by tables summarizing natural gas supply and disposition from 1990 to 1994 for each Census Division and each State. Annual historical data are shown at the national level.

  11. Natural gas annual 1995

    SciTech Connect

    1996-11-01

    The Natural Gas Annual provides information on the supply and disposition of natural gas to a wide audience including industry, consumers, Federal and State agencies, and educational institutions. The 1995 data are presented in a sequence that follows natural gas (including supplemental supplies) from its production to its end use. This is followed by tables summarizing natural gas supply and disposition from 1991 to 1995 for each Census Division and each State. Annual historical data are shown at the national level.

  12. Natural Gas Basics

    SciTech Connect

    2016-06-01

    Natural gas powers about 150,000 vehicles in the United States and roughly 22 million vehicles worldwide. Natural gas vehicles (NGVs) are a good choice for high-mileage fleets -- such as buses, taxis, and refuse vehicles -- that are centrally fueled or operate within a limited area or along a route with natural gas fueling stations. This brochure highlights the advantages of natural gas as an alternative fuel, including its domestic availability, established distribution network, relatively low cost, and emissions benefits.

  13. Natural Gas Basics

    SciTech Connect

    2016-06-08

    Natural gas powers about 150,000 vehicles in the United States and roughly 22 million vehicles worldwide. Natural gas vehicles (NGVs) are a good choice for high-mileage fleets -- such as buses, taxis, and refuse vehicles -- that are centrally fueled or operate within a limited area or along a route with natural gas fueling stations. This brochure highlights the advantages of natural gas as an alternative fuel, including its domestic availability, established distribution network, relatively low cost, and emissions benefits.

  14. 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

    2017-02-01

    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.

  15. Learning in Nature

    ERIC Educational Resources Information Center

    Brody, Michael

    2005-01-01

    This paper traces the evolution of a theory of learning in nature in order to explain how people learn in natural settings. The intellectual roots of the theory in informal learning, cognition, affective development, experiential and meaningful learning are described and the synthesis into a comprehensive theory of learning in nature are…

  16. Nature in the City.

    ERIC Educational Resources Information Center

    Ferbert, Mary Lou

    1981-01-01

    Describes a science program developed by the Cleveland Museum of Natural History, "Nature in the City," in which students and teachers learn together about the natural community surrounding their school. Includes program's rationale, list of "adventures," and methods. Discusses strategies of Sherlock Holmes'"adventure" focusing on animal tracks…

  17. Phosphocreatine protects endothelial cells from oxidized low-density lipoprotein-induced apoptosis by modulating the PI3K/Akt/eNOS pathway.

    PubMed

    Ahsan, Anil; Han, Guozhu; Pan, Junfang; Liu, Shumin; Padhiar, Arshad Ahmed; Chu, Peng; Sun, Zhengwu; Zhang, Zonghui; Sun, Bin; Wu, Jingjun; Irshad, Aisha; Lin, Yuan; Peng, Jinyong; Tang, Zeyao

    2015-12-01

    Endothelial apoptosis triggered by oxidized low-density lipoprotein (oxLDL) can accelerate the progression of endothelial dysfunction atherosclerosis. Phosphocreatine (PCr) is a natural compound, which has been used in cardiac disease and cardiopulmonary resuscitation. However, its protective effects on atherosclerosis and its mechanism have not been clarified. In the present study, we investigated the anti-apoptotic effect of phosphocreatine in human umbilical vein endothelial cells (HUVECs) exposed to oxLDL and explored the possible mechanisms. HUVECs were pre-treated with 10-30 mM PCr and then stimulated with oxLDL. Cell morphology, cytotoxicity and apoptosis were evaluated by light microscopy, CCK assay, and flow cytometry respectively. Levels of Bax, Bcl-2, protein expression of protein kinase B (Akt), eNOS and caspase activities were assessed by Western blotting. Reactive oxygen species (ROS) and mitochondrial membrane potential (MMP) were measured with fluorescent probes. Lactate dehydrogenase (LDH), malondialdehyde (MDA), nitric oxide (NO) and superoxide dismutase (SOD) contents were determined by spectrophotometer. Our results showed that PCr dose-dependently prevented oxLDL associated HUVEC cytotoxicity and apoptotic biochemical changes such as loss of MMP, LDH and MDA leakage and loss of SOD, decrease of Bcl-2/Bax protein ratio, activation of caspase-3 and 9, and ROS generation. In addition, the antiapoptotic effect of PCr was partially inhibited by a PI3K inhibitor (LY294002) and also enhanced p-Akt/Akt protein ratio, eNOS activation and NO production. In conclusion, our data show that the inhibition of oxLDL-induced endothelial apoptosis by PCr is due, at least in part to its anti-oxidant activity and its ability to modulate the PI3K/Akt/eNOS signaling pathway.

  18. iNOS Activation Regulates β-catenin Association with Its Partners in Endothelial Cells

    PubMed Central

    Gonzalez, Deyarina; Rojas, Armando; Herrera, Maria Beatriz; Conlan, R. Steven

    2012-01-01

    Background Signals that disrupt β-catenin association to cadherins may influence the translocation of β-catenin to the nucleus to regulate transcription. Post-translational modification of proteins is a signalling event that may lead to changes in structural conformation, association or function of the target proteins. NO and its derivatives induce nitration of proteins during inflammation. It has been described that animals treated with NO donors showed increased permeability due to modulation of VE-cadherin/catenin complex. We, therefore, aim to evaluate the effect of iNOS activation on the expression, nuclear localisation and function of β-catenin in endothelial cells. Methodology/Principal Findings Expression, nuclear localisation, post-translational modifications and function of β-catenin was analysed by cell fractionation, immunoprecipitation, immunoblots, QRT-PCR and permeability assays in murine endothelial cells (H5V). Influence of macrophage activation on expression of VE-cadherin/p120-catenin/β-catenin complex in co-cultured H5V cells was also assessed. Activation of macrophages to produce NO provoked a decrease in VE-cadherin/p120-catenin/β-catenin expression in H5V cells. Phosphorylation of β-catenin, p120-catenin and VE-cadherin, and reduction in the barrier properties of the cell monolayer was associated with iNOS induction. Moreover, high NO levels provoked nitration of β-catenin, and induced its translocation to the nucleus. In the nucleus of NOS activated cells, nitration levels of β-catenin influenced its association with TCF4 and p65 proteins. High levels of NO altered β-catenin mediated gene expression of NFκB and Wnt target genes without affecting cell viability. Conclusions NOS activity modulates β-catenin post-translational modifications, function and its association with different partners to promote endothelial cell survival. Therapeutic manipulation of iNOS levels may remove a critical cytoprotective mechanism of importance in

  19. Natural Orifice Surgery: Transdouglas Surgery—a New Concept

    PubMed Central

    Stark, Michael

    2008-01-01

    Background: During the 20th century, laparoscopic procedures replaced most traditional abdominal operations and achieved high-quality standards. It seemed that the optimal surgical method had been achieved; however, a new concept, which might possibly become even safer and simpler is now being developed, the concept of Natural Orifice Surgery (NOS). The existing natural openings of the body started to be used for introduction of surgical instruments for diagnostic purposes and surgical procedures, avoiding penetrating the abdominal wall. Parallel to the American Natural Orifice Surgery Consortium for Assessment and Research (NOSCAR) group, is the New European Surgical Academy (NESA) established in Berlin on June 23, 2006. It is the first European-based NOS working group with participation of scientists and surgeons from different disciplines and countries. After the published experimental achievements had been presented and discussed, the working group decided to concentrate mainly on the transvaginal/transdouglas access in women. Database: A new surgical instrument, the Transdouglas Endoscopic Device (TED) has been designed. This is a flexible multichannel instrument enabling single-entry surgical, urological, and gynecological operations. TED respects the anatomy of the pelvis. To get to the upper abdomen, an S-shaped device was designed, bending first to the front, and then backwards. For the lower abdomen, the U-shaped mode of the instrument was designed. The wide diameter of the device (35 mm) and its multichannel design enables simultaneous use of different instruments, therefore avoiding hybrid procedures. Various surgical and gynecological procedures have been successfully simulated, and the manufacturing of the device is in progress. Preclinical studies will start soon. Conclusions: Transvaginal/transdouglas surgery is expected to be a valid alternative to traditional endoscopic procedures in women. It seems that NOS will create a spectrum of innovative

  20. 75 FR 66802 - Calvert Cliffs Nuclear Power Plant, LLC; Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and 2...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-29

    ... COMMISSION Calvert Cliffs Nuclear Power Plant, LLC; Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and 2... Regulatory Commission (the Commission) has granted the request of Calvert Cliffs Nuclear Power Plant, LLC... Operating License Nos. DPR-53 and DPR-69 for the Calvert Cliffs Nuclear Power Plant, Unit......

  1. 75 FR 6223 - PSEG Nuclear LLC; Hope Creek Generating Station and Salem Nuclear Generating Station, Unit Nos. 1...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-08

    ... COMMISSION PSEG Nuclear LLC; Hope Creek Generating Station and Salem Nuclear Generating Station, Unit Nos. 1... Hope Creek Generating Station (HCGS) and the Salem Nuclear Generating Station, Unit Nos. 1 and 2 (Salem), located in Salem County, New Jersey. In accordance with 10 CFR 51.21, the NRC prepared an...

  2. 75 FR 17159 - Notice of Availability of the Proposed Notice of Sale (NOS) for Outer Continental Shelf (OCS) Oil...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-05

    ... Minerals Management Service Notice of Availability of the Proposed Notice of Sale (NOS) for Outer... (GOM) AGENCY: Minerals Management Service, Interior. ACTION: Notice of availability of the proposed NOS... potential bidders may be obtained from the Public Information Unit, Gulf of Mexico Region,...

  3. 75 FR 76495 - Virginia Electric and Power Company North Anna Power Station, Unit Nos. 1 and 2 Surry Power...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-08

    ...), for North Anna Power Station, Unit Nos. 1 and 2 (NAPS), for Renewed Facility Operating License Nos... operation of NAPS and Surry located in Louisa County, Virginia, and Surry County, Virginia, respectively... completed its environmental assessment of the proposed EAL changes to NAPS and Surry. The staff...

  4. 75 FR 32516 - Virginia Electric and Power Company; North Anna Power Station, Unit Nos. 1 and 2; Surry Power...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-08

    ... Station, Unit Nos. 1 and 2 (NAPS) and Surry Power Station, Unit Nos. 1 and 2 (SPS) located in Lake Anna...% nitrogen at SPS and NAPS. The licensee's letter dated November 24, 2009, contains proprietary information... model Firehawk 7 Air Mask SCBA with a gas mixture of 35% oxygen and 65% nitrogen at SPS and NAPS,...

  5. 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

    ... Anna Power Station, Unit Nos. 1 and 2 (NAPS), for Renewed Facility Operating License Nos. NPF-4 and NPF.... DPR-32 and DPR-37, issued to Virginia Electric and Power Company (the licensee), for operation of NAPS... Continuation of Construction and the Operation,'' for NAPS dated April 1973, and Surry dated May 1972 and...

  6. 75 FR 57061 - Public Land Order No. 7749; Extension of Public Land Order Nos. 6801 and 6812; Arizona

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-17

    ... Bureau of Land Management Public Land Order No. 7749; Extension of Public Land Order Nos. 6801 and 6812; Arizona AGENCY: Bureau of Land Management, Interior. ACTION: Public land order. SUMMARY: This order extends the duration of two withdrawals created by Public Land Order Nos. 6801 and 6812 for an...

  7. Detecting nitrous oxide reductase (nosZ) genes in soil metagenomes: method development and implications for the nitrogen cycle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Incomplete denitrification in soils represents a major source of nitrous oxide (N2O), a potent greenhouse gas. The key enzyme for mitigating N2O emissions is NosZ, which catalyzes N2O reduction to N2 and is generally attributed to denitrifiers. We recently described an “atypical” functional NosZ enz...

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

    SciTech Connect

    Bai Ni; Kido, Takashi; Kavanagh, Terrance J.; Kaufman, Joel D.; Rosenfeld, Michael E.; Breemen, Cornelis van; Eeden, Stephan F. van

    2011-09-01

    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 were 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 the

  9. On nature and bioethics.

    PubMed

    Peterson, Paul Silas

    2010-01-01

    The account of nature and humanity's relationship to nature are of central importance for bioethics. The Scientific Revolution was a critical development in the history of this question and many contemporary accounts of nature find their beginnings here. While the innovative approach to nature going out of the seventeenth century was reliant upon accounts of nature from the early modern period, the Middle Ages, late-antiquity and antiquity, it also parted ways with some of the understandings of nature from these epochs. Here I analyze this development and suggests that some of the insights from older understandings of nature may be helpful for bioethics today, even if there can be no simple return to them.

  10. Examining the Sources for our Understandings about Science: Enduring conflations and critical issues in research on nature of science in science education

    NASA Astrophysics Data System (ADS)

    Abd-El-Khalick, Fouad

    2012-02-01

    This position paper addresses some enduring, as well as emerging issues, associated with the crucial question of benchmarking understandings about nature of science (NOS) for precollege science education. The question of benchmarking NOS understandings is revisited in light of the often cited, continuing debates among historians, philosophers, and sociologists of science, which are invoked to undermine the current widely accepted, domain-general, consensus-based, aspects approach to NOS. The paper explicates the underlying assumptions of, and argues for, this consensus approach. However, the paper calls for extending the current framework and advances a developmental perspective that allows for incorporating controversial NOS issues into this framework. The paper also examines recent calls to altogether abandon the domain-general approach to NOS research and development in science education in favor of a domain-specific approach. The paper argues that, contrary to what its advocates assume, a domain-specific approach is susceptible to the same criticisms often invoked against a domain-general approach. Instead, the paper argues for complementarity and reciprocity between the two approaches, and explicates how the latter can be achieved. Finally, the paper critiques current calls to privilege accounts of context-specific, day-to-day scientific practice and scientists' accounts of their enterprise as sources for deriving understandings about NOS in lieu of scholarship in history, philosophy, and sociology of science (HPSS). The paper argues that, while important, these can only supplement rather than replace HPSS scholarship as a major source for deriving understandings about NOS.

  11. Functional proteomic analysis of a three-tier PKCepsilon-Akt-eNOS signaling module in cardiac protection.

    PubMed

    Zhang, Jun; Baines, Christopher P; Zong, Chenggong; Cardwell, Ernest M; Wang, Guangwu; Vondriska, Thomas M; Ping, Peipei

    2005-02-01

    Cardiac protective signaling networks have been shown to involve PKCepsilon. However, the molecular mechanisms by which PKCepsilon interacts with other members of these networks to form task-specific modules remain unknown. Among 93 different PKCepsilon-associated proteins that have been identified, Akt and endothelial nitric oxide (NO) synthase (eNOS) are of importance because of their independent abilities to promote cell survival and prevent cell death. The simultaneous association of PKCepsilon, Akt, and eNOS has not been examined, and, in particular, the formation of a module containing these three proteins and the role of such a module in the regulation of NO production and cardiac protection are unknown. The present study was undertaken to determine whether these molecules form a signaling module and, thereby, play a collective role in cardiac signaling. Using recombinant proteins in vitro and PKCepsilon transgenic mouse hearts, we demonstrate the following: 1) PKCepsilon, Akt, and eNOS interact and form signaling modules in vitro and in the mouse heart. Activation of either PKCepsilon or Akt enhances the formation of PKCepsilon-Akt-eNOS signaling modules. 2) PKCepsilon directly phosphorylates and enhances activation of Akt in vitro, and PKCepsilon activation increases phosphorylation and activation of Akt in PKCepsilon transgenic mouse hearts. 3) PKCepsilon directly phosphorylates eNOS in vitro, and this phosphorylation enhances eNOS activity. Activation of PKCepsilon in vivo increased phosphorylation of eNOS at Ser(1177), indicating eNOS activation. This study characterizes, for the first time, the physical, as well as functional, coupling of PKCepsilon, Akt, and eNOS in the heart and implicates these PKCepsilon-Akt-eNOS signaling modules as critical signaling elements during PKCepsilon-induced cardiac protection.

  12. Exploring the Use of Lesson Study to Develop Elementary Preservice Teachers' Pedagogical Content Knowledge for Teaching Nature of Science

    ERIC Educational Resources Information Center

    Akerson, Valarie L.; Pongsanon, Khemmawadee; Park Rogers, Meredith A.; Carter, Ingrid; Galindo, Enrique

    2017-01-01

    This study explored a modified version of Japanese Lesson Study to determine whether and how it influenced preservice elementary teachers in their abilities to deliver science lessons that included nature of science (NOS) to their own students. We used a case study approach that focused on one subset of a cohort of preservice elementary teachers…

  13. The Effect of a "Science, Technology and Society" Course on Prospective Teachers' Conceptions of the Nature of Science

    ERIC Educational Resources Information Center

    Celik, Suat; Bayrakceken, Samih

    2006-01-01

    The aim of this study is to assess prospective teachers' views of some aspects of the nature of science (NOS) and the effects of a "Science, Technology and Society" (STS) course embedded with scientific investigation (SI) on these views. A questionnaire consisting of 13 items was given to 212 prospective teachers enrolled in a STS course…

  14. From the Horse's Mouth: Why Scientists' Views Are Crucial to Nature of Science Understanding

    ERIC Educational Resources Information Center

    Hodson, Derek; Wong, Siu Ling

    2014-01-01

    Written in response to criticism of our work by Fouad Abd-El-Khalick, this position paper reaffirms and reinforces our position about the need to broaden and enrich the scope of nature of science (NOS) oriented curricula by exposing students to the voices of practising scientists. While Abd-El-Khalick's motivation for promoting the so-called…

  15. 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…

  16. An Evaluation of the Particle Physics Masterclass as a Context for Student Learning about the Nature of Science

    ERIC Educational Resources Information Center

    Wadness, Michael J.

    2010-01-01

    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…

  17. Effectiveness of Science-Technology-Society (STS) Instruction on Student Understanding of the Nature of Science and Attitudes toward Science

    ERIC Educational Resources Information Center

    Akcay, Behiye; Akcay, Hakan

    2015-01-01

    The study reports on an investigation about the impact of science-technology-society (STS) instruction on middle school student understanding of the nature of science (NOS) and attitudes toward science compared to students taught by the same teacher using traditional textbook-oriented instruction. Eight lead teachers used STS instruction an…

  18. Developing a Science Teacher Education Course That Supports Student Teachers' Thinking and Teaching about the Nature of Science

    ERIC Educational Resources Information Center

    Sorensen, Pete; Newton, Len; McCarthy, Sue

    2012-01-01

    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…

  19. Addressing Nature of Science Core Tenets with the History of Science: An Example with Sickle-Cell Anemia & Malaria

    ERIC Educational Resources Information Center

    Howe, Erica M.

    2007-01-01

    The history of science (HOS) has proven to be a useful pedagogical tool to help students learn about what has come to be regarded as an agreed upon set of core nature of science (NOS) tenets. The following article illustrates an example of how teachers can instrumentally use the history of research on heterozygote protection in sickle-cell anemia…

  20. 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…