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

    ERIC Educational Resources Information Center

    Aflalo, Ester

    2014-01-01

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

  4. 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.

  5. 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…

  6. 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…

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

    ERIC Educational Resources Information Center

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

    2016-01-01

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

  8. 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…

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

    ERIC Educational Resources Information Center

    Bazzul, Jesse

    2017-01-01

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

  10. Expression of NRAMP1 and iNOS in Mycobacterium avium subsp. paratuberculosis naturally infected cattle.

    PubMed

    Delgado, F; Estrada-Chávez, C; Romano, M; Paolicchi, F; Blanco-Viera, F; Capellino, F; Chavez-Gris, G; Pereira-Suárez, A L

    2010-09-01

    Paratuberculosis (PTB) is a chronic disease caused by M. avium subsp. paratuberculosis (MAP) that affects several animal species, and some studies have suggested that there may be a relationship between Crohn's disease and PTB. Significant aspects of PTB pathogenesis are not yet completely understood, such as the role of macrophages. Natural resistance-associated macrophage protein 1 (NRAMP1) and the inducible nitric oxide synthase (iNOS) molecules have shown nonspecific effects against several intracellular pathogens residing within macrophages. However, these molecules have been scarcely studied during natural infection with MAP. In this work, changes in NRAMP1 and iNOS expression were surveyed by immunohistochemistry in tissue samples from MAP-infected cattle and healthy controls. Our findings show strong specific immunolabeling against both NRAMP1 and iNOS molecules, throughout granulomatous PTB-compatible lesions in ileum and ileocaecal lymph nodes from paratuberculous cattle compared with uninfected controls, suggesting a relationship between the expression of these molecules and the pathogenesis of PTB disease. Copyright 2009 Elsevier Ltd. All rights reserved.

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

    NASA Astrophysics Data System (ADS)

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

    2017-08-01

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

  12. Integrating nature of science instruction into a physical science content course for preservice elementary teachers: NOS views of teaching assistants

    NASA Astrophysics Data System (ADS)

    Hanuscin, Deborah L.; Akerson, Valarie L.; Phillipson-Mower, Teddie

    2006-09-01

    Teacher education programs have met with limited success in improving teachers' understanding of the nature of science (NOS). Research suggests that such efforts could be enhanced by addressing NOS in preservice teachers' science courses. We planned NOS instruction in a physical science content course for preservice elementary teachers. Our first concern was the NOS views of the instructors for the course, which included undergraduate teaching assistants (UTAs). We examined the NOS views of nine UTAs, and the impact of job-embedded professional development on their views. Although initially UTAs held a number of views inconsistent with science education reforms, four modes of explicit-and-reflective interventions, including analysis of NOS views of preservice teachers, resulted in favorable changes in UTAs' views.

  13. 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.

  14. 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

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

    ERIC Educational Resources Information Center

    Faikhamta, Chatree

    2013-01-01

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

  16. 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.

  17. 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.

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

    ERIC Educational Resources Information Center

    Karaman, Ayhan

    2017-01-01

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

  19. 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,…

  20. 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,…

  1. 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

  2. [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.

  3. 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.

  4. GNB3, eNOS, and mitochondrial DNA polymorphisms correlate to natural longevity in a Xinjiang Uygur population.

    PubMed

    Nijiati, Muyesai; Saidaming, Abulajiang; Qiao, Jun; Cheng, Zuheng; Qiu, Changchun; Sun, Yujing

    2013-01-01

    In centenarian populations, application of the positive biology approach (examination of positive phenotypes in aging) has revealed that mitochondrial DNA (mtDNA) mutation accumulation may be linked to human longevity; however, the role of guanine nucleotide-binding protein (G protein) abnormalities modulated by G-protein beta-3 (GNB3) and nitrate (NO2) production associated with endothelial nitric oxide synthase (eNOS), commonly appearing in age-related diseases, remains undetermined. The association between the mtDNA 5178A/C, mtDNA 10398A/G, GNB3 C825T, and eNOS polymorphisms and longevity in a Uygur population (Xinjiang region, China) were investigated. A total of 275 experimental subjects aged ≥ 100 or with 4 generations currently living were screened for inclusion in the centenarian (>100 years) and nonagenarian groups (90-100 years), and 112 65-70 year old control subjects were selected. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to examine mtDNA 5178A/C, mtDNA 10398A/G, GNB3 C825T, and eNOS. Associations between polymorphic loci, genotypes, and longevity were analyzed. 165 included subjects (M∶F = 107∶58; mean age = 97 ± 3 years; mean age 100-113 years) were assigned to the centenarian (M∶F = 46/19; n = 65) and nonagenarian groups (M∶F = 61/39; n = 100). Associations between mtDNA C5178A and A10398G polymorphisms with longevity in the centenarian group with mtDNA genotype frequencies 5178A and 10398G were 66.79% and 36.8%. Applying the overwhelming longevity observed in Uygur populations, these findings demonstrate that mtDNA 5178A/C and 10398A/G, GNB3 C825T, and eNOS polymorphisms are useful as a genetic basis for longevity.

  5. A crucial role of fractional occupation numbers of natural orbitals (NOs) in the description of double excitations in response time-dependent NO functional theory

    NASA Astrophysics Data System (ADS)

    Gritsenko, O. V.

    2017-09-01

    We demonstrate a crucial role of fractional occupation numbers (FONs) of natural orbitals (NOs) in the description of double excitations in time-dependent NO functional theory (TDNOFT). An analytical dependence of the double excitation energy ωα on the ratio of the FONs is derived in a model from the matrix diagonalization problem. In the large ratio Heitler-London limit the derived formula reproduces the correct asymptotics of ωα of the ionic state of double excitation character. In the small ratio Møller-Plesset, MP limit the reverse relation of static MP perturbation theory emerges in the dynamical response theory to provide ωα .

  6. 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…

  7. 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…

  8. 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.…

  9. 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.…

  10. Value-added beef products (Productos Carnicos con Valor Agregado)

    Treesearch

    Mac Donaldson; Will Holder; Jan Holder

    2006-01-01

    I'm speaking for Will and Jan Holder, who couldn't be here. I happen to be familiar with Will and Jan's company, Ervin's Natural Beef, and its program because I've sold them cattle. Will and Jan's value-added beef program is based on their family ranch in the area known as The Blue, in the mountains of eastern Arizona.

  11. 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

  12. 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.

  13. 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.

  14. Natural product extract of Dicksonia sellowiana induces endothelium-dependent relaxations by a redox-sensitive Src- and Akt-dependent activation of eNOS in porcine coronary arteries.

    PubMed

    Rattmann, Yanna D; Anselm, Eric; Kim, Jong-Hun; Dal-Ros, Stéphanie; Auger, Cyril; Miguel, Obdulio G; Santos, Adair R S; Chataigneau, Thierry; Schini-Kerth, Valérie B

    2012-01-01

    The consumption of polyphenol-rich food is associated with a decreased mortality from coronary diseases. This study examined whether a standardized hydroalcoholic extract of Dicksonia sellowiana (HEDS) triggered endothelium-dependent relaxations in porcine coronary artery rings and characterized the underlying mechanism. The phosphorylation level of Src, Akt and eNOS was assessed by Western blot analysis, the formation of reactive oxygen species by dihydroethidine staining and the level of eNOS Ser1177 phosphorylation by immunohistochemical staining in sections of coronary arteries. HEDS-induced endothelium-dependent relaxations were strongly reduced by Nω-nitro-L-arginine, an eNOS inhibitor, and by its combination with charybdotoxin plus apamin, inhibitors of endothelium-derived hyperpolarizing factor-mediated responses. These relaxations were markedly reduced by MnTMPyP (a membrane-permeant mimetic of superoxide dismutase), polyethylene glycol catalase (PEG-catalase; a membrane-permeant analog of catalase), and by wortmannin (an inhibitor of PI3-kinase). HEDS-induced sustained phosphorylation of Akt and eNOS in endothelial cells was abolished by MnTMPyP, PEG-catalase and wortmannin. Oral administration of HEDS induced a significant decrease of mean arterial pressure in spontaneously hypertensive rats. These findings indicate that HEDS caused endothelium-dependent relaxations of coronary artery rings through the redox-sensitive activation of the endothelial PI3-kinase/Akt pathway leading to the subsequent activation of eNOS by phosphorylation. HEDS also has antihypertensive properties. Copyright © 2012 S. Karger AG, Basel.

  15. Nature

    NASA Astrophysics Data System (ADS)

    Heinhorst, Sabine; Cannon, Gordon

    1997-01-01

    The fact that two of the original articles by this year's Nobel laureates were published in Nature bears witness to the pivotal role of this journal in documenting pioneering discoveries in all areas of science. The prize for Physiology or Medicine was awarded to immunologists Peter C. Doherty (University of Tennessee) and Rolf M. Zinkernagel (University of Zurich, Switzerland), honoring work that, in the 1970s, laid the foundation for our current understanding of the way in which our immune system differentiates between healthy cells and virus-infected ones that are targeted for destruction (p 465 in the October 10 issue of vol. 383). Three researchers share the Chemistry award for their discovery of C60 buckminsterfullerenes. The work by Robert Curl, Richard Smalley (both at Rice University), and Harry Kroto (University of Sussex, UK) has led to a burst of new approaches to materials development and in carbon chemistry (p 561 of the October 17 issue of vol. 383). This year's Nobel prize in physics went to three U.S. researchers, Douglas Osheroff (Stanford University) and David M. Lee and Robert C. Richardson (Cornell University), who were honored for their work on superfluidity, a frictionless liquid state, of supercooled 3He (p 562 of the October 17 issue of vol. 383).

  16. Endothelial NOS (NOS3) impairs myocardial function in developing sepsis.

    PubMed

    van de Sandt, Annette M; Windler, Rainer; Gödecke, Axel; Ohlig, Jan; Zander, Simone; Reinartz, Michael; Graf, Jürgen; van Faassen, Ernst E; Rassaf, Tienush; Schrader, Jürgen; Kelm, Malte; Merx, Marc W

    2013-03-01

    Endothelial nitric oxide synthase (NOS)3-derived nitric oxide (NO) modulates inotropic response and diastolic interval for optimal cardiac performance under non-inflammatory conditions. In sepsis, excessive NO production plays a key role in severe hypotension and myocardial dysfunction. We aimed to determine the role of NOS3 on myocardial performance, NO production, and time course of sepsis development. NOS3(-/-) and C57BL/6 wildtype mice were rendered septic by cecum ligation and puncture (CLP). Cardiac function was analyzed by serial echocardiography, in vivo pressure and isolated heart measurements. Cardiac output (CO) increased to 160 % of baseline at 10 h after sepsis induction followed by a decline to 63 % of baseline after 18 h in wildtype mice. CO was unaltered in septic NOS3(-/-) mice. Despite the hyperdynamic state, cardiac function and mean arterial pressure were impaired in septic wildtype as early as 6 h post CLP. At 12 h, cardiac function in septic wildtype was refractory to catecholamines in vivo and respective isolated hearts showed impaired pressure development and limited coronary flow reserve. Hemodynamics remained stable in NOS3(-/-) mice leading to significant survival benefit. Unselective NOS inhibition in septic NOS3(-/-) mice diminished this survival benefit. Plasma NO( x )- and local myocardial NO( x )- and NO levels (via NO spin trapping) demonstrated enhanced NO( x )- and bioactive NO levels in septic wildtype as compared to NOS3(-/-) mice. Significant contribution by inducible NOS (NOS2) during this early phase of sepsis was excluded. Our data suggest that NOS3 relevantly contributes to bioactive NO pool in developing sepsis resulting in impaired cardiac contractility.

  17. 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,…

  18. 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,…

  19. 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…

  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. Association analysis of nitric oxide synthases: NOS1, NOS2A and NOS3 genes, with multiple sclerosis.

    PubMed

    AlFadhli, Suad; Mohammed, Eiman M A; Al Shubaili, Asmahan

    2013-07-01

    Multiple sclerosis (MS) is a chronic inflammatory autoimmune disorder of the central nervous system. To explore the genetic basis of three nitric oxide synthase (NOS) genes: NOS1, NOS2A and NOS3, with susceptibility to MS. A total of 122 MS patients and 118 healthy controls screened for NOS1 (rs2682826, rs41279104), NOS2A (CCTTT)n/(TAAA)n and NOS3 (rs1800783, rs1800779, rs2070744, 27bpVNTR) markers, using TaqMan®SNP Genotyping Assays and fragment analysis were enrolled in this study. QRT-PCR and ELISA were used to analyse the expression of NOS3 mRNA and Nitric Oxide (NO) levels. Two NOS3 markers were associated with susceptibility to MS and early disease development. The NOS3 rs1800779 G-allele (p = 0.04) and GG-genotype (p = 0.02) showed association with susceptibility to MS. Short NOS2 (CCTTT)n (p = 0.03) and short/long repeat (p = 0.04) genotypes also showed associations with MS. These associations were intensified by sub-division of patients into Kuwaiti Arabs and Persians (p < 0.05). The NOS3-27 bp-VNTR a-allele was associated with early MS disease onset ≤26 years (p = 0.04). The NOS3-27 bp-VNTR a/b-genotype resulted in 23% lower NO production and the NOS3-rs1800779 AA-genotype resulted in lower NOS3 expression. Haplotypes obtained from NOS2A and NOS3 showed increased susceptibility to MS. NOS1 showed no significant association with MS. This study provides evidence for the association between selected NOS2 and NOS3 markers and MS susceptibility.

  2. 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…

  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. 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…

  5. 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…

  6. 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…

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

    ERIC Educational Resources Information Center

    Hodson, Derek; Wong, Siu Ling

    2017-01-01

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

  8. 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…

  9. 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…

  10. 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,…

  11. 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,…

  12. 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.

  13. 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…

  14. 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…

  15. 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.

  16. 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…

  17. 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…

  18. 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…

  19. 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…

  20. 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.

  1. 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…

  2. 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…

  3. 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,…

  4. 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,…

  5. COMPARISON OF OXYGEN–INDUCED RADICAL INTERMEDIATES IN iNOS OXYGENASE DOMAIN WITH THOSE FROM nNOS and eNOS

    PubMed Central

    Berka, Vladimir; Liu, Wen; Wu, Gang; Tsai, Ah-lim

    2014-01-01

    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 control 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. PMID:25016313

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. 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…

  11. 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…

  12. Developing Understanding of the Nature of Science Within a Professional Development Program for Inservice Elementary Teachers: Project Nature of Elementary Science Teaching

    NASA Astrophysics Data System (ADS)

    Posnanski, Tracy J.

    2010-08-01

    Establishing literacy in science is often linked to building knowledge about the Nature of Science (NOS). This paper describes and evaluates an inservice program designed to build elementary teachers’ understanding of NOS and an awareness of how NOS impacts science classroom instruction. Data sources consisted of surveys, action research plan documentation and classroom observations. Program participants tended to demonstrate some gains in understanding more about NOS and they linked positive experiences in the program to the explicit and activity-based NOS instruction provided. Yet, participation in the professional development project might not have been equally beneficial for all teachers. The understanding of NOS may have been restricted to certain NOS aspects, and the demonstration of the participants’ understanding of NOS may have been short-lived with a somewhat limited impact on sustainable, long-term NOS-based classroom instruction. Implications for designing NOS related professional development programs and suggestions for improvements to further develop teacher understanding of NOS are discussed.

  13. 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…

  14. 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…

  15. 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…

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

    ERIC Educational Resources Information Center

    Buaraphan, Khajornsak

    2011-01-01

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

  17. 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…

  18. "It's the Nature of the Beast": The Influence of Knowledge and Intentions on Learning and Teaching Nature of Science.

    ERIC Educational Resources Information Center

    Schwartz, Renee S.; Lederman, Norman G.

    2002-01-01

    Examines the knowledge, intentions, and instructional practices of two beginning secondary science teachers as they learned the subject matter of the nature of science (NOS) and attempted to teach NOS during their student teaching experience and their first year of full-time teaching. Suggests that the relationship between NOS and science subject…

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

    ERIC Educational Resources Information Center

    Hansson, Lena; Leden, Lotta

    2016-01-01

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

  20. The Influence of Explicit Nature of Science and Argumentation Instruction on Preservice Primary Teachers' Views of Nature of Science

    ERIC Educational Resources Information Center

    McDonald, Christine V.

    2010-01-01

    There exists a general consensus in the science education literature around the goal of enhancing learners' views of nature of science (NOS). An extensive body of research in the field has highlighted the effectiveness of explicit NOS instructional approaches in improving learners' NOS views. Emerging research has suggested that engaging learners…

  1. Revisiting the Translation of Nature of Science Understandings into Instructional Practice: Teachers' Nature of Science Pedagogical Content Knowledge

    ERIC Educational Resources Information Center

    Wahbeh, Nader; Abd-El-Khalick, Fouad

    2014-01-01

    This study (a) assessed the influence of an integrated nature of science (NOS) instructional intervention on inservice secondary science teachers' understandings, retention of those understandings, and their NOS instructional planning and practices; and (b) examined factors that mediated the translation of teachers' NOS understandings into…

  2. Nitric oxide synthase enzymes in the airways of mice exposed to ovalbumin: NOS2 expression is NOS3 dependent.

    PubMed

    Bratt, Jennifer M; Williams, Keisha; Rabowsky, Michelle F; Last, Michael S; Franzi, Lisa M; Last, Jerold A; Kenyon, Nicholas J

    2010-01-01

    The function of the airway nitric oxide synthase (NOS) isoforms and the lung cell types responsible for its production are not fully understood. We hypothesized that NO homeostasis in the airway is important to control inflammation, which requires upregulation, of NOS2 protein expression by an NOS3-dependent mechanism. Mice from a C57BL/6 wild-type, NOS1(-/-), NOS2(-/-), and NOS3(-/-) genotypes were used. All mice strains were systemically sensitized and exposed to filtered air or ovalbumin (OVA) aerosol for two weeks to create a subchronic model of allergen-induced airway inflammation. We measured lung function, lung lavage inflammatory and airway epithelial goblet cell count, exhaled NO, nitrate and nitrite concentration, and airway NOS1, NOS2, and NOS3 protein content. Deletion of NOS1 or NOS3 increases NOS2 protein present in the airway epithelium and smooth muscle of air-exposed animals. Exposure to allergen significantly reduced the expression of NOS2 protein in the airway epithelium and smooth muscle of the NOS3(-/-) strain only. This reduction in NOS2 expression was not due to the replacement of epithelial cells with goblet cells as remaining epithelial cells did not express NOS2. NOS1(-/-) animals had significantly reduced goblet cell metaplasia compared to C57Bl/6 wt, NOS2(-/-), and NOS3(-/-) allergen-exposed mice. The airway epithelial and smooth muscle cells maintain a stable airway NO concentration under noninflammatory conditions. This "homeostatic" mechanism is unable to distinguish between NOS derived from the different constitutive NOS isoforms. NOS3 is essential for the expression of NOS2 under inflammatory conditions, while NOS1 expression contributes to allergen-induced goblet cell metaplasia.

  3. Nitric Oxide Synthase Enzymes in the Airways of Mice Exposed to Ovalbumin: NOS2 Expression Is NOS3 Dependent

    PubMed Central

    Bratt, Jennifer M.; Williams, Keisha; Rabowsky, Michelle F.; Last, Michael S.; Franzi, Lisa M.; Last, Jerold A.; Kenyon, Nicholas J.

    2010-01-01

    Objectives and Design. The function of the airway nitric oxide synthase (NOS) isoforms and the lung cell types responsible for its production are not fully understood. We hypothesized that NO homeostasis in the airway is important to control inflammation, which requires upregulation, of NOS2 protein expression by an NOS3-dependent mechanism. Materials or Subjects. Mice from a C57BL/6 wild-type, NOS1−/−, NOS2−/−, and NOS3−/− genotypes were used. All mice strains were systemically sensitized and exposed to filtered air or ovalbumin (OVA) aerosol for two weeks to create a subchronic model of allergen-induced airway inflammation. Methods. We measured lung function, lung lavage inflammatory and airway epithelial goblet cell count, exhaled NO, nitrate and nitrite concentration, and airway NOS1, NOS2, and NOS3 protein content. Results. Deletion of NOS1 or NOS3 increases NOS2 protein present in the airway epithelium and smooth muscle of air-exposed animals. Exposure to allergen significantly reduced the expression of NOS2 protein in the airway epithelium and smooth muscle of the NOS3−/− strain only. This reduction in NOS2 expression was not due to the replacement of epithelial cells with goblet cells as remaining epithelial cells did not express NOS2. NOS1−/− animals had significantly reduced goblet cell metaplasia compared to C57Bl/6 wt, NOS2−/−, and NOS3−/− allergen-exposed mice. Conclusion. The airway epithelial and smooth muscle cells maintain a stable airway NO concentration under noninflammatory conditions. This “homeostatic” mechanism is unable to distinguish between NOS derived from the different constitutive NOS isoforms. NOS3 is essential for the expression of NOS2 under inflammatory conditions, while NOS1 expression contributes to allergen-induced goblet cell metaplasia. PMID:20953358

  4. Seeking Historical Examples to Illustrate Key Aspects of the Nature of Science

    ERIC Educational Resources Information Center

    McComas, William F.

    2008-01-01

    Increasingly widespread agreement exists that the nature of science (NOS) must be an integral element of the K-12 science curriculum with emerging consensus on what specific NOS elements should be the focus of such instruction. In this study reported, eight recent trade books written by NOS experts addressing the nature of science for the general…

  5. 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…

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

    ERIC Educational Resources Information Center

    Kampourakis, Kostas

    2016-01-01

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

  7. Characterization of iNOS(+) Neutrophil-like ring cell in tumor-bearing mice.

    PubMed

    Virtuoso, Lauren P; Harden, Jamie L; Sotomayor, Paula; Sigurdson, Wade J; Yoshimura, Fuminobu; Egilmez, Nejat K; Minev, Boris; Kilinc, Mehmet O

    2012-07-30

    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. 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. The results showed that intracellular iNOS staining distinguished a granular iNOS(+) SSC(hi) CD11b(+) Gr-1(dim) 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. Tumor

  8. 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

  9. 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.

  10. 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.

  11. 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…

  12. 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…

  13. 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…

  14. 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,…

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

    ERIC Educational Resources Information Center

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

    2014-01-01

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

  16. 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,…

  17. 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…

  18. 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'…

  19. 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…

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

    ERIC Educational Resources Information Center

    Alsop, Steve; Gardner, Sam

    2017-01-01

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

  1. 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…

  2. 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…

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

    NASA Astrophysics Data System (ADS)

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

    2016-08-01

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

  4. 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

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

    NASA Astrophysics Data System (ADS)

    Hall, Garrett

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

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

    ERIC Educational Resources Information Center

    Wan, Zhi Hong; Wong, Siu Ling

    2016-01-01

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

  7. 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…

  8. 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…

  9. 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…

  10. 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…

  11. 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…

  12. 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…

  13. 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…

  14. 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…

  15. 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…

  16. 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…

  17. 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…

  18. 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…

  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. 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…

  1. 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…

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

    Code of Federal Regulations, 2011 CFR

    2011-01-01

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

    Code of Federal Regulations, 2013 CFR

    2013-01-01

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  4. 15 CFR Supplement Nos. 3-4 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. 3-4 to Part 742 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade (Continued) BUREAU OF... CONTROLS Supplement Nos. 3-4 to Part 742 ...

  5. 15 CFR Supplement Nos. 3-4 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. 3-4 to Part 742 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade (Continued) BUREAU OF... CONTROLS Supplement Nos. 3-4 to Part 742 ...

  6. 15 CFR Supplement Nos. 3-4 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. 3-4 to Part 742 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade (Continued) BUREAU OF... CONTROLS Supplement Nos. 3-4 to Part 742 ...

  7. Functional significance of differential eNOS translocation

    PubMed Central

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

    2006-01-01

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

  8. Regulation of iNOS-Derived ROS Generation by HSP90 and Cav-1 in Porcine Reproductive and Respiratory Syndrome Virus-Infected Swine Lung Injury.

    PubMed

    Yan, Meiping; Hou, Make; Liu, Jie; Zhang, Songlin; Liu, Bang; Wu, Xiaoxiong; Liu, Guoquan

    2017-08-01

    In the lungs, endothelial nitric oxide synthase (eNOS) is usually expressed in endothelial cells and inducible nitric oxide synthase (iNOS) is mainly expressed in alveolar macrophages and epithelial cells. Both eNOS and iNOS are involved in lung inflammation. While they play several roles in lung inflammation formation and resolution, their expression and activity are also regulated by inflammatory factors. Their expression relationship in virus infection-induced lung injury is not well addressed. In this report, we analyzed expression of both eNOS and iNOS, the production of nitric oxide (NO) and reactive oxygen species (ROS), and expression of their associated regulatory proteins, heat shock protein 90 (HSP90) and caveolin-1 (Cav-1), in a swine lung injury model induced by porcine reproductive and respiratory syndrome virus (PRRSV) infection. The combination of upregulation of iNOS and downregulation of eNOS was observed in both natural and experimental PRRSV-infected lungs, while the combination is much enhanced in natural infected lungs. While NO production is much reduced in both infections, ROS was enhanced only in natural infected lungs. Moreover, HSP90 is increased in both natural and experimental infection and less Cav-1 expressed was observed only in the natural PRRSV-infected lungs. Therefore, the increased ROS generation is likely due to the increased iNOS and its unbalanced regulation by HSP90 and Cav-1, and it also likely causes higher endothelial dysfunction in clinical PRRSV-infected lungs.

  9. 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.

  10. Nitric oxide pathway genes (NOS1AP and NOS1) are involved in PTSD severity, depression, anxiety, stress and resilience.

    PubMed

    Bruenig, Dagmar; Morris, Charles P; Mehta, Divya; Harvey, Wendy; Lawford, Bruce; Young, Ross McD; Voisey, Joanne

    2017-08-20

    The nitric oxide pathway in the hippocampus is involved in the biological stress response with detrimental consequences to cells and HPA axis feedback. Hippocampal atrophy and HPA axis feedback dysfunction are associated with posttraumatic stress disorder (PTSD). This study systematically investigates two genes of the nitric oxide pathway NOS1AP and NOS1 for a potential involvement in PTSD, comorbidities and resilience. A cohort of age and gender matched Vietnam veterans including trauma-exposed cases and controls was recruited and comprehensively assessed (n=299). A total of 49 NOS1AP and 16 NOS1 polymorphisms were analysed and genotypes correlated with gold standard clinical measures to assess PTSD severity and related phenotypes (depression, anxiety, stress, resilience) based on diagnostic status. Multiple NOS1AP polymorphisms were associated across all measures, and NOS1 polymorphisms were associated with PTSD severity, stress and resilience. The GG genotype of NOS1 polymorphism rs10744891 was associated with PTSD severity (surviving multiple correction) while the combined TT-TG genotypes were associated with resilience (p=0.005; p=0.033, respectively). This study indicates that NOS1AP and NOS1 from the nitric oxide pathway are likely to play a key role in PTSD, its comorbidities and resilience. Given the essential role of NOS1AP and NOS1 in stress response they may be reliable targets for screening and intervention strategies. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

  11. Single nucleotide polymorphisms in the NOS2 and NOS3 genes are associated with exhaled nitric oxide.

    PubMed

    Dahgam, Santosh; Nyberg, Fredrik; Modig, Lars; Naluai, Asa Torinsson; Olin, Anna-Carin

    2012-03-01

    Polymorphisms in nitric oxide synthase genes (NOS1, NOS2, and NOS3) have been suggested to have a major impact on fraction of exhaled nitric oxide (FENO), a biomarker of airway inflammation. However, the genetic contribution of NOS polymorphisms to FENO is not fully understood. The aim of this study was to investigate comprehensively the association between single nucleotide polymorphisms (SNPs) in all three NOS genes and FENO in an adult population, and to assess whether such associations are modified by asthma or atopy. In 1737 adults from a Swedish general population sample, FENO was measured and genetic variation in the NOS genes was assessed using 49 SNPs. The genetic effect of NOS polymorphisms on FENO, asthma, and atopy was estimated using multiple regression methods. In a multi-SNP model based on stepwise regression analysis, two SNPs in NOS2 and one in NOS3 showed independent associations with levels of FENO. For NOS2 SNP rs9901734, subjects had 5.3% (95% CI 1.0% to 9.7%) higher levels of FENO per G allele, and for rs3729508, subjects with CC or CT genotypes had 9.4% (95% CI 3.1% to 15.2%) higher levels compared with TT. For NOS3 SNP rs7830, subjects with GT or TT had 5.6% (95% CI 0.4% to 11.1%) higher levels than GG; the genetic effect of this SNP was stronger in asthmatics (21.9%, 95% CI 4.6% to 42.0%). These results suggest that NOS2 is the major NOS gene determining variability in exhaled nitric oxide in the healthy adult population, while NOS3 may play a more important role in asthmatic adults.

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

    PubMed

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

    2016-02-01

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

  13. 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

  14. 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…

  15. 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…

  16. 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…

  17. 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…

  18. 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

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

    NASA Astrophysics Data System (ADS)

    Akerson, Valarie; Donnelly, Lisa A.

    2010-01-01

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

  20. 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…

  1. 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…

  2. 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…

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

    ERIC Educational Resources Information Center

    Mesci, Gunkut; Schwartz, Renee' S.

    2017-01-01

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

  4. 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

  5. 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

  6. 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.

  7. The Relationship Between Endothelial Nitric Oxide Synthase Gene (NOS3) Polymorphisms, NOS3 Expression, and Varicocele.

    PubMed

    Kahraman, Cigdem Yuce; Tasdemir, Sener; Sahin, Ibrahim; Marzioglu Ozdemir, Ebru; Yaralı, Oguzhan; Ziypak, Tevfik; Adanur, Senol; Kahraman, Mustafa; Tatar, Abdulgani

    2016-04-01

    Varicocele is an abnormal enlargement of the pampiniform venous plexus in the scrotum. Varicocele is the most common cause of secondary male infertility. Nitric oxide (NO), which has a role on varicocele pathophysiology, is synthesized by endothelial nitric oxide synthase gene (NOS3). In our study, we aimed to explain the relationship between varicocele, three common NOS3 polymorphisms (T-786C, G894T, 4b/a), and NOS3 mRNA expression levels. We investigated NOS3 T-786C, G894T, and 4b/a polymorphisms in 102 patients with varicocele and 100 healthy controls. Twenty-four patients and 17 controls were chosen for expression studies based on polymorphism subgroupings. Subgroup 1 includes patients who have no minor allele polymorphisms, and subgroups 2, 3, and 4 have T-786C, G894T, and 4b/a polymorphisms, respectively. The 4b/a polymorphism demonstrated significantly elevated levels in both allele and genotype analysis in the control group compared to the patient group. The G894T polymorphism was statistically elevated for genotypic frequencies in the patient group compared to the control group, but this finding did not extend to allelic frequencies. There were no statistically significant differences in either the allelic or genotypic frequencies between patients and control groups for the T-786C polymorphism. When patient and control expression levels were compared without considering the subgroups, the NOS3 expression level was found to be statistically higher in the patient group. There were no statistically significant differences in the patient and control group expression levels when stratified by subgroup, nor was there any effect of the polymorphisms under study on expression levels. The 4b/a polymorphism may have a protective effect for varicocelem and G894T polymorphism may contribute to varicocele occurrence by lowering the level of NO. The higher NOS3 expression levels in the patient group may be a kind of dilator compensatory mechanism to protect vascular

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

    PubMed Central

    Miller, Marie C. Desaulniers; 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. PMID:20194807

  9. 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.

  10. 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.

  11. 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…

  12. 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…

  13. 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…

  14. 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…

  15. 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…

  16. 15 CFR Supplement Nos. 2-3 to Part... - [Reserved

    Code of Federal Regulations, 2011 CFR

    2011-01-01

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

    Code of Federal Regulations, 2014 CFR

    2014-01-01

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

    Code of Federal Regulations, 2012 CFR

    2012-01-01

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  19. 15 CFR Supplement Nos. 2-3 to Part... - [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-01-01

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  20. 15 CFR Supplement Nos. 2-3 to Part... - [Reserved

    Code of Federal Regulations, 2013 CFR

    2013-01-01

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  1. Experienced Teachers' Strategies for Assessing Nature of Science Conceptions in the Elementary Classroom

    NASA Astrophysics Data System (ADS)

    Akerson, Valarie L.; Cullen, Theresa A.; Hanson, Deborah L.

    2010-10-01

    This study explored the nature of science (NOS) assessments K-4 classroom teachers developed for measuring students’ understandings of NOS elements. We used the Views of Nature of Science Questionnaire-Form VNOS-D2 (Views of Nature of Science Elementary School Version 2) and interviews to verify that teachers’ conceptions of NOS were sufficient to enable them to teach and assess NOS. We collected copies of teachers’ action research designs, lesson plans, and assessment tools, conducted classroom observations and made field notes of their science instruction and assessments. We videotaped conversations at monthly workshops to note discussion surrounding teaching and assessing NOS in K-4 classrooms. We found that experienced teachers designed a variety of strategies for assessing NOS conceptions that differed by grade level.

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

    NASA Astrophysics Data System (ADS)

    Leden, Lotta; Hansson, Lena

    2017-07-01

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

  3. 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.

  4. 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

  5. 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

  6. 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.

  7. Taiwanese Preservice Teachers' Conceptions of Nature and the Nature of Science.

    ERIC Educational Resources Information Center

    Liu, Shiang-Yao; Lederman, Norman G.

    This study examined views of the human relationship with the natural world and understandings about the nature of science (NOS) held by preservice elementary teachers in the context of Taiwan. The participants included 54 third-year students enrolled in the departments of science education and mathematics education at a teacher college. Data were…

  8. 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…

  9. 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…

  10. 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).

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

    PubMed Central

    Förstermann, Ulrich; Li, Huige

    2011-01-01

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

  12. NOS-2 Inhibition in Phosgene-Induced Acute Lung Injury.

    PubMed

    Filipczak, Piotr T; Senft, Albert P; Seagrave, JeanClare; Weber, Waylon; Kuehl, Philip J; Fredenburgh, Laura E; McDonald, Jacob D; Baron, Rebecca M

    2015-07-01

    Phosgene exposure via an industrial or warfare release produces severe acute lung injury (ALI) with high mortality, characterized by massive pulmonary edema, disruption of epithelial tight junctions, surfactant dysfunction, and oxidative stress. There are no targeted treatments for phosgene-induced ALI. Previous studies demonstrated that nitric oxide synthase 2 (NOS-2) is upregulated in the lungs after phosgene exposure; however, the role of NOS-2 in the pathogenesis of phosgene-induced ALI remains unknown. We previously demonstrated that NOS-2 expression in lung epithelium exacerbates inhaled endotoxin-induced ALI in mice, mediated partially through downregulation of surfactant protein B (SP-B) expression. Therefore, we hypothesized that a selective NOS-2 inhibitor delivered to the lung epithelium by inhalation would mitigate phosgene-induced ALI. Inhaled phosgene produced increases in bronchoalveolar lavage fluid protein, histologic lung injury, and lung NOS-2 expression at 24 h. Administration of the selective NOS-2 inhibitor 1400 W via inhalation, but not via systemic delivery, significantly attenuated phosgene-induced ALI and preserved epithelial barrier integrity. Furthermore, aerosolized 1400 W augmented expression of SP-B and prevented downregulation of tight junction protein zonula occludens 1 (ZO-1), both critical for maintenance of normal lung physiology and barrier integrity. We also demonstrate for the first time that NOS-2-derived nitric oxide downregulates the ZO-1 expression at the transcriptional level in human lung epithelial cells, providing a novel target for ameliorating vascular leak in ALI. Our data demonstrate that lung NOS-2 plays a critical role in the development of phosgene-induced ALI and suggest that aerosolized NOS-2 inhibitors offer a novel therapeutic strategy for its treatment. © The Author 2015. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e

  13. NOS-2 Inhibition in Phosgene-Induced Acute Lung Injury

    PubMed Central

    Filipczak, Piotr T.; Senft, Albert P.; Seagrave, JeanClare; Weber, Waylon; Kuehl, Philip J.; Fredenburgh, Laura E.; McDonald, Jacob D.; Baron, Rebecca M.

    2015-01-01

    Phosgene exposure via an industrial or warfare release produces severe acute lung injury (ALI) with high mortality, characterized by massive pulmonary edema, disruption of epithelial tight junctions, surfactant dysfunction, and oxidative stress. There are no targeted treatments for phosgene-induced ALI. Previous studies demonstrated that nitric oxide synthase 2 (NOS-2) is upregulated in the lungs after phosgene exposure; however, the role of NOS-2 in the pathogenesis of phosgene-induced ALI remains unknown. We previously demonstrated that NOS-2 expression in lung epithelium exacerbates inhaled endotoxin-induced ALI in mice, mediated partially through downregulation of surfactant protein B (SP-B) expression. Therefore, we hypothesized that a selective NOS-2 inhibitor delivered to the lung epithelium by inhalation would mitigate phosgene-induced ALI. Inhaled phosgene produced increases in bronchoalveolar lavage fluid protein, histologic lung injury, and lung NOS-2 expression at 24 h. Administration of the selective NOS-2 inhibitor 1400 W via inhalation, but not via systemic delivery, significantly attenuated phosgene-induced ALI and preserved epithelial barrier integrity. Furthermore, aerosolized 1400 W augmented expression of SP-B and prevented downregulation of tight junction protein zonula occludens 1 (ZO-1), both critical for maintenance of normal lung physiology and barrier integrity. We also demonstrate for the first time that NOS-2-derived nitric oxide downregulates the ZO-1 expression at the transcriptional level in human lung epithelial cells, providing a novel target for ameliorating vascular leak in ALI. Our data demonstrate that lung NOS-2 plays a critical role in the development of phosgene-induced ALI and suggest that aerosolized NOS-2 inhibitors offer a novel therapeutic strategy for its treatment. PMID:25870319

  14. 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.

  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. The canonical ensemble via symplectic integrators using Nosé and Nosé-Poincaré chains.

    PubMed

    Leimkuhler, Benedict J; Sweet, Christopher R

    2004-07-01

    Simulations that sample from the canonical ensemble can be generated by the addition of a single degree of freedom, provided that the system is ergodic, as described by Nosé with subsequent modifications by Hoover to allow sampling in real time. Nosé-Hoover dynamics is not ergodic for small or stiff systems and the addition of auxiliary thermostats is needed to overcome this deficiency. Nosé-Hoover dynamics, like its derivatives, does not have a Hamiltonian structure, precluding the use of symplectic integrators which are noted for their long term stability and structure preservation. As an alternative to Nosé-Hoover, the Hamiltonian Nosé-Poincaré method was proposed by Bond, Laird, and Leimkuhler [J. Comput. Phys. 151, 114 (1999)], but the straightforward addition of thermostatting chains does not sample from the canonical ensemble. In this paper a method is proposed whereby additional thermostats can be applied to a Hamiltonian system while retaining sampling from the canonical ensemble. This technique has been used to construct thermostatting chains for the Nosé and Nosé-Poincaré methods. (c) 2004 American Institute of Physics.

  17. 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.

  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. 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…

  20. 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…

  1. 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…

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

    ERIC Educational Resources Information Center

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

    2014-01-01

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

  3. 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…

  4. 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.

  5. 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.

  6. 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

  7. 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.

  8. 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

  9. 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

  10. 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

  11. Interior of Left Powerhouse showing generator Nos. 14. This view ...

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

    Interior of Left Powerhouse showing generator Nos. 1-4. This view is from the catwalk at the level of the overhead crane, looking west. - Columbia Basin Project, Grand Coulee Dam Powerplant Complex, Grand Coulee, Grant County, WA

  12. 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

  13. 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

  14. 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

  15. 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

  16. Vault Area (original section), east corridor, looking north (Vault Nos. ...

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

    Vault Area (original section), east corridor, looking north (Vault Nos. 1-9 - Fort McNair, Film Store House, Fort Lesley J. McNair, P Street between Third & Fourth Streets, Southwest, Washington, District of Columbia, DC

  17. 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

  18. 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.

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

    NASA Astrophysics Data System (ADS)

    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 data measured 26 undergraduates' distal and proximal knowledge of the NOS with respect to their ability to reason. The instruments used in this case study yielded qualitative data, which were coded using NVivo7 and inductively analyzed. All data analyses were subject to instrumental triangulation, inter-rater reliability, and member-checking. These analyses determined that undergraduates' formal epistemological knowledge of professional science matured. These changes accompanied improved reasoning skills and matured beliefs about the NOS. In particular, students' reasoning changed as they realized that scientific knowledge is never absolute or certain but tentative and subject to change. In general, the findings suggest that this SSI-based curriculum enhanced collegiate students' understanding of social issues that affect their lives. Implications of this research are discussed.

  20. 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.

  1. eNOS-uncoupling in age-related erectile dysfunction

    PubMed Central

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

    2011-01-01

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

  2. 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…

  3. 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…

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

    ERIC Educational Resources Information Center

    Michel, Hanno; Neumann, Irene

    2016-01-01

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

  5. 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.

  6. 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.

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

    NASA Astrophysics Data System (ADS)

    DiGiuseppe, Maurice

    2014-05-01

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

  8. 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…

  9. 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…

  10. Revising Instruction to Teach Nature of Science

    ERIC Educational Resources Information Center

    Lederman, Norman G.; Lederman, Judith S.

    2004-01-01

    Current reform documents place a strong emphasis on students' understandings of the nature of science (NOS). Interestingly, the importance of this educational outcome is not new and has been agreed upon as important by most scientists and science educators for the past 100 years. Despite numerous attempts, including the major curricular reform…

  11. 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…

  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. Scientific Communication and the Nature of Science

    ERIC Educational Resources Information Center

    Nielsen, Kristian H.

    2013-01-01

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

  15. 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…

  16. 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…

  17. 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.

  18. 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

  19. 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.

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

    NASA Astrophysics Data System (ADS)

    Thao-Do, Thi Phuong; Yuenyong, Chokchai

    2017-06-01

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

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. 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.

  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. 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.

  8. 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…

  9. 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…

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

    ERIC Educational Resources Information Center

    Aglarci, Oya; Sariçayir, Hakan; Sahin, Musa

    2016-01-01

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

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

    ERIC Educational Resources Information Center

    Çil, Emine; Çepni, Salih

    2016-01-01

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

  12. 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…

  13. 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…

  14. 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…

  15. 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…

  16. 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…

  17. 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…

  18. 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…

  19. 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…

  20. 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…

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

    ERIC Educational Resources Information Center

    Buaraphan, Khajornsak

    2009-01-01

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

  2. 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…

  3. 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…

  4. The "Nature of Science" in the School Curriculum: The Great Survivor

    ERIC Educational Resources Information Center

    Jenkins, Edgar W.

    2013-01-01

    This paper explores the ways in which the "nature of science" (NoS) has been interpreted, accommodated and justified within school curricula since science was first schooled in the mid-nineteenth century. It explores how different interpretations of "the NoS" have been invoked by those seeking to reform school science education…

  5. 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…

  6. 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…

  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. 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…

  9. 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…

  10. 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…

  11. 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…

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

    ERIC Educational Resources Information Center

    Akerson, Valarie; Donnelly, Lisa A.

    2010-01-01

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

  13. 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…

  14. 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…

  15. 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…

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

    ERIC Educational Resources Information Center

    Buaraphan, Khajornsak; Abedin Forhad, Ziaul

    2014-01-01

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

  17. 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…

  18. 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…

  19. 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…

  20. 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…

  1. 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…

  2. The Relationship between Science Teachers' Understandings of the Nature of Science and Their Classroom Practices

    ERIC Educational Resources Information Center

    Kurup, Raj

    2014-01-01

    An adequate understanding of the Nature of Science (NOS) has become increasingly important for science teachers in the context of the recent curriculum revisions being implemented in Grades R-9 in South African schools. This study explored the NOS conceptions and the influence of these conceptions on the classroom practice of two groups of…

  3. 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…

  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. 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…

  6. 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.

  7. 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

  8. 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…

  9. 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…

  10. National Plan to Expand NOS' Operational Modeling Capabilities

    NASA Astrophysics Data System (ADS)

    Zhang, A.; Burke, P.

    2016-02-01

    Real-time marine forecast products based on numerical ocean models are a powerful tool serving a variety of uses, such as marine navigation planning for commercial port operations, harmful algal bloom formation and tracking, hazard response, and emergency search and rescue. Advances in data acquisition technology, ocean dynamics, numerical schemes and visualization tools have made marine forecasting products more accurate and reliable, and the dissemination of operational model products more timely and user friendly. NOAA's National Ocean Service (NOS) has been developing and maintaining a national network of hydrodynamic operational oceanographic nowcast and forecast modeling systems to support navigational and environmental applications in U.S. coastal and estuarine waters, and the Great Lakes. These operational forecast systems (OFS) provide the maritime community with nowcast and forecast guidance of water levels, currents, water temperature, and salinity for 48 to 120 hours. NOS has collaborated with the National Weather Service (NWS) and the Office of Oceanic and Atmospheric Research (OAR) and extramural partners from academia and the local maritime community to develop and implement the current suite of NOS OFS. NOS currently operates and maintains 15 OFS for the U.S. East and West coasts, the Gulf of Mexico, and the Great Lakes, to cover approximately 35% of the CONUS coast. Over the next 8 to 10 years, NOS intends to provide complete coverage of the continental U.S and establish the necessary national infrastructure to enable other types of forecasts. This presentation will provide an overview of NOS' new regional approach to expand its OFS capabilities and services nationally, a pathway to transition research models and applications to operations, and anticipated challenges to implement this plan.

  11. 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

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

    NASA Astrophysics Data System (ADS)

    Jiang, Feng; McComas, William F.

    2014-09-01

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

  13. 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…

  14. 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…

  15. 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,…

  16. 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,…

  17. 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…

  18. 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…

  19. Differential cardiovascular responses to blockade of nNOS or iNOS in rostral ventrolateral medulla of the rat

    PubMed Central

    Chan, Samuel H H; Wang, Ling-Lin; Wang, Shu-Huei; Chan, Julie Y H

    2001-01-01

    We investigated the contribution of neuronal or inducible nitric oxide synthase (nNOS or iNOS) at the rostral ventrolateral medulla (RVLM) to central cardiovascular regulation by endogenous nitric oxide (NO), using Sprague-Dawley rats anaesthetized and maintained with propofol.Microinjection bilaterally into the RVLM of a NO trapping agent, carboxy-2-phenyl-4,4,5,5-tetramethylimidazoline-l-oxy-l-3-oxide (10, 50 or 100 nmoles) resulted in significant hypotension and bradycardia.Similar application of a selective antagonist of nNOS, 7-nitroindazole (1, 2.5 or 5 pmoles), or selective antagonists of iNOS, aminoguanidine (125, 250 or 500 pmoles), N6-(l-iminoethyl)-L-lysine (250 pmoles) or S-methylisothiourea (250 pmoles), induced respectively a reduction or an enhancement in systemic arterial pressure, heart rate and power density of the vasomotor components in the spectrum of arterial blood pressure signals, the experimental index for sympathetic neurogenic vasomotor tone.Both hypotension and bradycardia induced by the NO precursor, L-arginine (100 nmoles), were significantly blunted when aminoguanidine (250 pmoles) was co-microinjected bilaterally into the RVLM. On the other hand, co-administered 7-nitroindazole (2.5 pmoles) was ineffective.Whereas low doses of S-nitro-N-acetylpenicillamine (0.25 or 0.5 nmoles) elicited hypertension and tachycardia, high doses of this non-nitrate NO donor (5 nmoles) induced hypotension and bradycardia.Reverse transcription – polymerase chain reaction analysis revealed that both iNOS and nNOS mRNA were expressed in the ventrolateral medulla.We conclude that the prevalence of nNOS over iNOS activity at the RVLM and the associated dominance of sympathoexcitation over sympathoinhibition may underlie the maintenance of sympathetic vasomotor outflow and stable systemic arterial pressure by the endogenous NO. PMID:11399678

  20. 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

  1. 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.

  2. Las Rocas Nos Cuentan (Rocks Tell Their Stories)

    ERIC Educational Resources Information Center

    Llerandi-Roman, Pablo A.

    2012-01-01

    Many Earth science lessons today still focus on memorizing the names of rocks and minerals. This led the author to develop a lesson that reveals the fascinating stories told by rocks through the study of their physical properties. He first designed the lesson for Puerto Rican teachers, hence its Spanish title: "Las Rocas Nos Cuentan Su Historia."…

  3. 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. 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

  5. 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

  6. 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

  7. 77 FR 1061 - Endangered Species; File Nos. 16229 and 16548

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-09

    ... National Oceanic and Atmospheric Administration RIN 0648-XA881 Endangered Species; File Nos. 16229 and... issued under the authority of the Endangered Species Act of 1973, as amended (ESA; 16 U.S.C. 1531 et seq... Zoo, 4401 Zoo ] Parkway, Asheboro, NC 27203 , and the Springfield Science Museum, 21 Edwards Street...

  8. 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

  9. 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

  10. 78 FR 21112 - Marine Mammals; File Nos. 16992 and 14535

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-09

    ..., Ph.D., Hawaii Institute of Marine Biology, University of Hawaii, P.O. Box 1106, Kailua, HI 96734, has... of Marine Biology in Kaneohe, HI. Researchers would conduct hearing measurements using suction cup... National Oceanic and Atmospheric Administration RIN 0648-XB161 Marine Mammals; File Nos. 16992 and...

  11. Context view, Building Nos. 2728, looking north from a spot ...

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

    Context view, Building Nos. 27-28, looking north from a spot south of Building No. 28 - U.S. Veterans Hospital, Jefferson Barracks, Medical Officer in Charge Residence, VA Medical Center, Jefferson Barracks Division 1 Jefferson Barracks Drive, Saint Louis, Independent City, MO

  12. Context view, Building Nos. 2729, with Building No. 28 in ...

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

    Context view, Building Nos. 27-29, with Building No. 28 in the center, looking west at front of buildings, from a spot south of Building No. 29 - U.S. Veterans Hospital, Jefferson Barracks, Medical Officer in Charge Residence, VA Medical Center, Jefferson Barracks Division 1 Jefferson Barracks Drive, Saint Louis, Independent City, MO

  13. 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

  14. 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."…

  15. 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.

  16. 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.

  17. 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

  18. 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

  19. Service building. Cross section thru dry dock nos. 4 & ...

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

    Service building. Cross section thru dry dock nos. 4 & 5 showing service bldg & 20-75-150 ton cranes (dry dock associates, May 23, 1941). In files of Cushman & Wakefield, building no. 501, Philadelphia Naval Business Center. - Naval Base Philadelphia-Philadelphia Naval Shipyard, Service Building, Dry Docks No. 4 & 5, League Island, Philadelphia, Philadelphia County, PA

  20. 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

  1. 78 FR 50395 - Endangered Species; File Nos. 17557 and 17273

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-19

    ...: Permits and Conservation Division, Office of Protected Resources, NMFS, 1315 East-West Highway, Room 13705... NOS Lab and used to support law enforcement actions, research studies (primarily genetics), and... parts and samples would be used to support law enforcement actions, research studies (primarily genetics...

  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

    2016-12-01

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

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

    NASA Astrophysics Data System (ADS)

    Michel, Hanno; Neumann, Irene

    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.

  4. 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.

  5. 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

  6. 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

  7. Explanation and the Nature of Scientific Knowledge

    NASA Astrophysics Data System (ADS)

    McCain, Kevin

    2015-10-01

    Explaining phenomena is a primary goal of science. Consequently, it is unsurprising that gaining a proper understanding of the nature of explanation is an important goal of science education. In order to properly understand explanation, however, it is not enough to simply consider theories of the nature of explanation. Properly understanding explanation requires grasping the relation between explanation and understanding, as well as how explanations can lead to scientific knowledge. This article examines the nature of explanation, its relation to understanding, and how explanations are used to generate scientific knowledge via inferences to the best explanation. Studying these features and applications of explanation not only provides insight into a concept that is important for science education in its own right, but also sheds light on an aspect of recent debates concerning the so-called consensus view of nature of science (NOS). Once the relation between explanation, understanding, and knowledge is clear, it becomes apparent that science is unified in important ways. Seeing this unification provides some support for thinking that there are general features of NOS of the sort proposed by the consensus view and that teaching about these general features of NOS should be a goal of science education.

  8. 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.

  9. Contribution of the nos-pdt operon to virulence phenotypes in methicillin-sensitive Staphylococcus aureus.

    PubMed

    Sapp, April M; Mogen, Austin B; Almand, Erin A; Rivera, Frances E; Shaw, Lindsey N; Richardson, Anthony R; Rice, Kelly C

    2014-01-01

    Nitric oxide (NO) is emerging as an important regulator of bacterial stress resistance, biofilm development, and virulence. One potential source of endogenous NO production in the pathogen Staphylococcus aureus is its NO-synthase (saNOS) enzyme, encoded by the nos gene. Although a role for saNOS in oxidative stress resistance, antibiotic resistance, and virulence has been recently-described, insights into the regulation of nos expression and saNOS enzyme activity remain elusive. To this end, transcriptional analysis of the nos gene in S. aureus strain UAMS-1 was performed, which revealed that nos expression increases during low-oxygen growth and is growth-phase dependent. Furthermore, nos is co-transcribed with a downstream gene, designated pdt, which encodes a prephenate dehydratase (PDT) enzyme involved in phenylalanine biosynthesis. Deletion of pdt significantly impaired the ability of UAMS-1 to grow in chemically-defined media lacking phenylalanine, confirming the function of this enzyme. Bioinformatics analysis revealed that the operon organization of nos-pdt appears to be unique to the staphylococci. As described for other S. aureus nos mutants, inactivation of nos in UAMS-1 conferred sensitivity to oxidative stress, while deletion of pdt did not affect this phenotype. The nos mutant also displayed reduced virulence in a murine sepsis infection model, and increased carotenoid pigmentation when cultured on agar plates, both previously-undescribed nos mutant phenotypes. Utilizing the fluorescent stain 4-Amino-5-Methylamino-2',7'-Difluorofluorescein (DAF-FM) diacetate, decreased levels of intracellular NO/reactive nitrogen species (RNS) were detected in the nos mutant on agar plates. These results reinforce the important role of saNOS in S. aureus physiology and virulence, and have identified an in vitro growth condition under which saNOS activity appears to be upregulated. However, the significance of the operon organization of nos-pdt and potential

  10. 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.

  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. 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

  13. 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

  14. 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

  15. Influence of intravascular low level He-Ne laser irradiation on iNOS, total-NOS, and ET-1 in acute spinal cord-injured rabbits

    NASA Astrophysics Data System (ADS)

    Yin, Zhenchun; Dong, Yinghai; Zhu, Jing

    2005-07-01

    Objective To research the influence of intravascular low level Laser irradiation (ILLLI) on total NOS, iNOS, and ET-1 in spinal cord following acute spinal cord injury (ASCI), and discuss the protective effects of ILLLI on neurons .Methods 72 rabbits were randomly divided into 3 groups: treatment group, injury group and control group. In treatment group and injury group, after laminectomy at the level of T-13, ASCI was performed by using Allen"s method with slight modification (6g×10cm) on rabbits. After injury, rabbits were treated immediately with He-Ne laser (power 5 mW, 1 hour per day for 10 days). At the day of 10th after treatment, total-NOS, iNOS, and ET-1 in spinal cord tissues were measured. Results The expression level of total-NOS, iNOS, and ET-1 in spinal cord in injury group were significantly higher than those in control group (P<0.05), while after ILLLI the level of these index in treatment group decreased statistically significantly compared with those in injury group (P<0.05). Conclusion ILLLI can significantly decrease the expression level of total-NOS, iNOS, and ET-1 in spinal cord. It indicates that ILLLI can relieve the overexpression of total-NOS, iNOS, and ET-1 ,and thus can perform protective effects on neurons in the course of secondary spinal cord injury (SSCI) following ASCI

  16. Accumbens nNOS Interneurons Regulate Cocaine Relapse

    PubMed Central

    Smith, Alexander C.W.; Scofield, Michael D.; Heinsbroek, Jasper A.; Gipson, Cassandra D.; Neuhofer, Daniela; Roberts-Wolfe, Doug J.; Spencer, Sade; Garcia-Keller, Constanza; Stankeviciute, Neringa M.; Smith, Rachel J.; Allen, Nicholas P.; Lorang, Melissa R.; Griffin, William C.; Boger, Heather A.

    2017-01-01

    Relapse to drug use can be initiated by drug-associated cues. The intensity of cue-induced relapse is correlated with the induction of transient synaptic potentiation (t-SP) at glutamatergic synapses on medium spiny neurons (MSNs) in the nucleus accumbens core (NAcore) and requires spillover of glutamate from prefrontal cortical afferents. We used a rodent self-administration/reinstatement model of relapse to show that cue-induced t-SP and reinstated cocaine seeking result from glutamate spillover, initiating a metabotropic glutamate receptor 5 (mGluR5)-dependent increase in nitric oxide (NO) production. Pharmacological stimulation of mGluR5 in NAcore recapitulated cue-induced reinstatement in the absence of drug-associated cues. Using NO-sensitive electrodes, mGluR5 activation by glutamate was shown to stimulate NO production that depended on activation of neuronal nitric oxide synthase (nNOS). nNOS is expressed in ∼1% of NAcore neurons. Using a transgene strategy to express and stimulate designer receptors that mimicked mGluR5 signaling through Gq in nNOS interneurons, we recapitulated cue-induced reinstatement in the absence of cues. Conversely, using a transgenic caspase strategy, the intensity of cue-induced reinstatement was correlated with the extent of selective elimination of nNOS interneurons. The induction of t-SP during cued reinstatement depends on activating matrix metalloproteinases (MMPs) and selective chemogenetic stimulation of nNOS interneurons recapitulated MMP activation and t-SP induction (increase in AMPA currents in MSNs). These data demonstrate critical involvement of a sparse population of nNOS-expressing interneurons in cue-induced cocaine seeking, revealing a bottleneck in brain processing of drug-associated cues where therapeutic interventions could be effective in treating drug addiction. SIGNIFICANCE STATEMENT Relapse to cocaine use in a rat model is associated with transient increases in synaptic strength at prefrontal cortex

  17. Endothelial (NOS3 E298D) and inducible (NOS2 exon 22) nitric oxide synthase polymorphisms, as well as plasma NOx, influence sepsis development.

    PubMed

    Martin, Guadalupe; Asensi, Víctor; Montes, A Hugo; Collazos, Julio; Alvarez, Victoria; Pérez-Is, Laura; Carton, José A; Taboada, Francisco; Valle-Garay, Eulalia

    2014-11-15

    Nitric oxide (NO) influences susceptibility to infection and hemodynamic failure (HF) in sepsis. NOS3 and NOS2 SNPs might modify plasma nitrite/nitrate (NOx) levels, sepsis development, hemodynamics and survival. 90 severely septic and 91 non-infected ICU patients were prospectively studied. NOS3 (E298D), NOS3 (-786 T/C), NOS3 (27 bp-VNTR), and NOS2A (exon 22) SNPs and plasma NOx levels were assessed. 21 patients (11.6%) died, 7 with sepsis. TT homozygotes and T allele carriers of NOS3 (E298D) and AG carriers of the NOS2A (exon 22) SNPs were more frequent among septic compared to non-infected ICU patients (p < 0.05). Plasma NOx was higher in septic, especially in septic with hemodynamic failure (HF) or fatal outcome (p < 0.006). Plasma NOx was higher in carriers of the T allele of the NOS3 (E298D) SNP (p = 0.006). Sepsis independently associated with HF, increased NOx, peripheral neutrophils, and fibrinogen levels, decreased prothrombin and the presence of the NOS3 (E298D) and NOS2A (exon 22) SNPs. A low APACHE II score was the only variable associated with sepsis survival. NOx was independently associated with sepsis, HF, decreased neutrophils and higher APACHE. NOS3 (E298D) and NOS2A (exon 22) SNPs, individually and in combination, and plasma NOx, associated with sepsis development. NOx associated with HF and fatal outcome. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. 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.

  19. 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.

  20. 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.

  1. Teaching elements of nature of science: A yearlong case study of a fourth-grade teacher

    NASA Astrophysics Data System (ADS)

    Akerson, Valarie L.; Abd-El-Khalick, Fouad

    2003-12-01

    This study examined and supported the efforts of Tina, an experienced elementary teacher, in helping her fourth graders internalize informed views of the inferential, tentative, and creative nature of science (NOS). Tina held informed views of, and was motivated to teach about, NOS. The study aimed to answer the following question: What specific supports were needed to enable Tina to make the target NOS elements explicit in her teaching? The lead researcher visited Tina's classroom every week and interacted with her on a continuous basis. Data sources included classroom observations and videotapes, teacher NOS questionnaires and associated interviews, teacher-researcher communications, and teacher and researcher logs. Although Tina's understandings and intentions were necessary to enable her to teach about NOS, they were not sufficient. Tina needed support to translate her NOS views and intentions into pedagogically appropriate instructional activities that would make the target NOS aspects accessible to her students. Socially mediated support was needed at the personal level in terms of helping Tina activate her tacit NOS understandings, and at the professional level in terms of modeling explicit NOS instruction in Tina's own classroom by the lead researcher.

  2. 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.

  3. 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.

  4. 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.

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

    PubMed Central

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

    2013-01-01

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

  6. 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

  7. 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

  8. 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…

  9. Historical Short Stories as Nature of Science Instruction in Secondary Science Classrooms: Science Teachers' Implementation and Students' Reactions

    ERIC Educational Resources Information Center

    Reid-Smith, Jennifer Ann

    2013-01-01

    This study explores the use of historical short stories as nature of science (NOS) instruction in thirteen secondary science classes. The stories focus on the development of science ideas and include statements and questions to draw students' and teachers' attention to key NOS ideas and misconceptions. This study used mixed methods to examine how…

  10. 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…

  11. 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…

  12. 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…

  13. 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…

  14. 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…

  15. 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…

  16. 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…

  17. 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…

  18. What Third-Grade Students of Differing Ability Levels Learn about Nature of Science after a Year of Instruction

    ERIC Educational Resources Information Center

    Akerson, Valarie; Nargund-Joshi, Vanashri; Weiland, Ingrid; Pongsanon, Khemmawadee; Avsar, Banu

    2014-01-01

    This study explored third-grade elementary students' conceptions of nature of science (NOS) over the course of an entire school year as they participated in explicit-reflective science instruction. The "Views of" NOS-D (VNOS-D) was administered pre instruction, during mid-school year, and at the end of the school year to track…

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

    ERIC Educational Resources Information Center

    Mulvey, Bridget K.; Bell, Randy L.

    2017-01-01

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

  20. 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…

  1. 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…

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

    ERIC Educational Resources Information Center

    Berkovitz, Joseph

    2017-01-01

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

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

    ERIC Educational Resources Information Center

    Cakmakci, Gultekin

    2017-01-01

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

  4. 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…

  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. 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…

  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. 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…

  9. 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…

  10. 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.…

  11. 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.

  12. [Malignant fibrous histiocytoma: pleomorphic sarcoma NOS or pleomorphic fibrosarcoma].

    PubMed

    Meister, P

    2005-03-01

    The entity and nosology of pleomorphic malignant fibrous histiocytoma (MFH) is still ambiguous. The actual WHO-Classification uses pleomorphic malignant fibrous histiocytoma (MFH) and pleomorphic sarcoma NOS (not otherwise specified) synonymously. On the other hand text and illustrations convey the impression, that these tumors also could be pleomorphic lipo-, leio- or rhabdomyosarcomas etc. It would have been more informative to emphasize, that with the above mentioned specific sarcoma types MFH-like appearance may occur. Furthermore it would have been more up to date to consider pleomorphic sarcomas NOS as pleomorphic fibrosarcomas and include them in the chapter of fibroblastic and myofibroblastic tumors. This concept already has been carried out for the former myxoid variant of MFH, nowadays preferentially called myxofibrosarcoma. There is controversial discussion about the clinical significance of exact typing of pleomorphic sarcomas. Problems may also occur due to the lack of standards, which degree of desmin expression signifies leiomyosarcoma or just indicates myofibroblasts in MFH. The requirement of exclusion of other tumor-types before diagnosing pleomorphic fibrosarcoma still remains obligatory. After verification of the diagnosis pleomorphic sarcoma NOS or pleomorphic fibrosarcoma, grading e.g. according to criteria of the FFCCS can be carried out. Most cases of pleomorphic fibrosarcoma will qualify as high grade malignant.

  13. Significant negative correlations between capillary expressed eNOS and Alzheimer lesion burden.

    PubMed

    Jeynes, Brian; Provias, John

    2009-10-09

    Nitric oxide [NO] is known to have vasoregulatory, neuroprotective and blood-brain barrier (BBB) related transport functions in the human CNS. Altered NO levels are suspected of contributing to neurodegenerative disorders, including Alzheimer's disease (AD). NO is produced as a result of the activity of one or more of three isoforms of nitrogen oxide synthase (NOS). In this study we compared Alzheimer and normative comparison brain samples, from temporal and calcarine cortices, with respect to the interactive correlation between eNOS, iNOS and nNOS isoform positive capillaries and the presence of neurofibrillary tangles (NFTs) and senile plaques (SPs). Cortical samples were taken from the superior temporal and calcarine cortices of 10 confirmed AD and 10 non-demented comparison group (CG) brains. Contiguous coronal sections were stained using immunohistochemistry techniques to stain for tau protein, beta amyloid (A beta) n-termini ([40 and 42]), eNOS, iNOS and nNOS. The densities of NFTs, SPs, and eNOS, iNOS and nNOS positive capillaries were recorded. Non-parametric statistical analyses were applied to the data. Our results demonstrate a significant negative correlation between the presence of eNOS positive capillaries and NFTs and SPs in both cortices in AD brains. Our results support the view that eNOS activity should be targeted for further investigation, and that factors involved in the regulation of NO production may be amenable to therapeutic intervention.

  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. 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...

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. 15 CFR Supplement Nos.1-3 to Part 746 - [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 2 2010-01-01 2010-01-01 false Nos.1 Supplement Nos.1-3 to Part 746 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade (Continued) BUREAU OF... CONTROLS Supplement Nos.1-3 to Part 746 ...

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

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 15 Commerce and Foreign Trade 2 2011-01-01 2011-01-01 false Nos.1 Supplement Nos.1-3 to Part 746 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade (Continued) BUREAU OF... CONTROLS Supplement Nos.1-3 to Part 746 ...

  2. 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.

  3. Development of nature of science ideas through authentic scientific research

    NASA Astrophysics Data System (ADS)

    Burgin, Stephen Randall

    Understanding the ways in which scientific knowledge develops, or the epistemology of science, is believed to be a crucial component of scientific literacy. This construct is more formally known as Nature of Science (NOS) within the science education community. The merits of three different approaches to NOS teaching and learning in the context of authentic scientific research on high school student participants' NOS ideas were explored in this study. These approaches were an explicit/reflective approach, a reflective approach and an implicit approach. The effectiveness of explicit approaches over implicit approaches has been demonstrated in school contexts, but little is known regarding the merits of these approaches when the practices that learners engage in are highly authentic in the ways in which they model the work of professional scientists. If an implicit approach yields positive impacts in authentic contexts, then which specific factors within those contexts are influential in doing so? The Authentic Experiences in Science Program (AESP), a summer program designed for high school students offered at a major research university, offered a wonderful context for an investigation of these issues. In this program, high school students worked for an extended period of time in a research scientist's laboratory on an authentic research project. Additionally, seminars offered through the program provided a venue for the implementation of the three aforementioned NOS teaching and learning approaches. An open-ended questionnaire designed to assess respondent NOS ideas was administered to 30 participants of the AESP both at the beginning and again at the end of the program. From those thirty, six case study participants were selected, and through a series of observations and interviews, influential factors impacting their NOS ideas within their specific laboratory placements were identified. Results of categorical data analysis of the questionnaires revealed that the

  4. 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

  5. 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.

  6. Aqueous Humor Outflow Physiology in NOS3 Knockout Mice.

    PubMed

    Lei, Yuan; Zhang, Xuejin; Song, Maomao; Wu, Jihong; Sun, Xinghuai

    2015-07-01

    To investigate the role of endothelial nitric oxide synthase (eNOS) on conventional outflow function using NOS3 knockout (KO) mice. Intraocular pressure was measured in both NOS3 KO and wild type (WT) by rebound tonometry. Outflow facility was measured by perfusing enucleated mouse eyes at multiple pressure steps. A subset of eyes was sectioned and stained for histology. Mock aqueous humor ± the nitric oxide (NO) donors nitroprusside dihydrate (SNP) or S-Nitroso-N-Acetyl-D,L-Penicillamine (SNAP) was perfused into enucleated eyes. SNP and SNAP was administered topically at 0, 1, 2, and 3 hours while the contralateral eyes served as vehicle controls. Intraocular pressure was measured in both eyes before and after the last drug treatment. Intraocular pressure was higher in KO mice (18.2 ± 0.7 mm Hg vs. 13.9 ± 0.5 mm Hg, mean ± SEM, n = 30, P < 0.05), and pressure-dependent conventional drainage was significantly lower (0.0058 ± 0.0005 μL/min/mm Hg, mean ± SEM, n = 21) compared with WT mice (0.0082 ± 0.0013 μL/min/mm Hg, n = 23, P < 0.05). No obvious morphological differences in iridiocorneal angle tissues were observed in hematoxylin and eosin (H&E)-stained sections. SNP and SNAP significantly increased pressure-dependent drainage in KO animals (n = 12, P < 0.05). In WT mice, SNP and SNAP caused a significant increase in pressure dependent drainage (n = 12, P < 0.05) to a similar degree as in KO mice. Topical application of SNP significantly reduced IOP in WT and KO mice (n = 12, P < 0.05), but SNAP did not change IOP significantly (n = 19). NOS3 KO mice have elevated IOP, which is likely the result of reduced pressure-dependent drainage. These findings are consistent with human data showing polymorphisms in the NOS3 gene associate with ocular hypertension and the development of glaucoma.

  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 plants.

    PubMed

    2014-06-01

    We welcome our new sister journal Nature Plants and the increased commitment to the plant science community that it represents. This is an opportunity for Nature Genetics to emphasize the use of genetic and genomic tools and resources in discovering new plant biology and solving major agricultural challenges.

  9. Natural death.

    PubMed

    Oehmichen, M; Meissner, C

    2000-01-01

    The increasing age of every human being is the beginning of the end of life, an obviously natural process, but any attempt to define the term 'natural death' soon encounters difficulties in defining what is meant by 'natural'. In the industrialized countries of the West, for example 'natural death' is thought of as the opposite of non-natural types of death such as accidental death, suicide, and homicide. The aim of our present survey is to discuss the meaning of the term 'natural death' under a clinical, a forensic and a scientific point of view with regard to recent developments especially in molecular biology. If there are 'external' physical influences, a medical-technical manipulation, a therapeutic or molecular biological intervention cannot be definitely ruled out as the cause of death, then use of the term 'natural death' in general is open to question. It will only remain meaningful if it can be applied with a specific meaning in definite practical situations. Current research and medical technology, however, do not allow use of the term 'natural death' in its conventional sense: it can thus be stricken from the medical vocabulary. Copyright 2000 S. Karger AG, Basel

  10. 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…

  11. 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…

  12. 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…

  13. 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…

  14. 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…

  15. 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…

  16. 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…

  17. Comparison of iNOS inhibition by antisense and pharmacological inhibitors after spinal cord injury.

    PubMed

    Pearse, D D; Chatzipanteli, K; Marcillo, A E; Bunge, M B; Dietrich, W D

    2003-11-01

    Inducible nitric oxide synthase (iNOS) is a key mediator of inflammation during pathological conditions. We examined, through the use of selective iNOS inhibitors, the role of iNOS in specific pathophysiological processes after spinal cord injury (SCI), including astrogliosis, blood-spinal cord barrier (BSCB) permeability, polymorphonuclear leukocyte infiltration, and neuronal cell death. Administration of iNOS antisense oligonucleotides (ASOs) (intraspinally at 3 h) or the pharmacological inhibitors, N-[3(Aminomethyl) benzyl] acetamidine (1400 W) (i.v./i.p. 3 and 9 h) or aminoguanidine (i.p. at 3 and 9 h) after moderate contusive injury decreased the number of iNOS immunoreactive cells at the injury site by 65.6% (iNOS ASOs), 62.1% (1400 W), or 59% (aminoguanidine) 24 h postinjury. iNOS activity was reduced 81.8% (iNOS ASOs), 56.7% (1400 W), or 67.9% (aminoguanidine) at this time. All iNOS inhibitors reduced the degree of BSCB disruption (plasma leakage of rat immunoglobulins), with iNOS ASO inhibition being more effective (reduced by 58%). Neutrophil accumulation within the injury site was significantly reduced by iNOS ASOs and 1400 W by 78.8% and 20.9%, respectively. Increased astrogliosis was diminished with iNOS ASOs but enhanced following aminoguanidine. Detection of necrotic and apoptotic neuronal cell death by propidium iodide and an FITC-conjugated Annexin V antibody showed that iNOS inhibition could significantly retard neuronal cell death rostral and caudal to the injury site. These novel findings indicate that acute inhibition of iNOS is beneficial in reducing several pathophysiological processes after SCI. Furthermore, we demonstrate that the antisense inhibition of iNOS is more efficacious than currently available pharmacological agents.

  18. 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,...

  19. 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.

  20. 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…

  1. 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.

  2. [The effects of pronuciferine on NO and NOS production in cultured human umbilical vein endothelium cells].

    PubMed

    Xiao, Hua; Chen, Aihua; Ji, Aimin; Li, Zhiliang

    2005-06-01

    To investigate the effects of Pronuciferine on nitric oxide (NO), total nitric oxide synthase (tNOS) and inducible nitric oxide synthase (iNOS) production in cultured Human Umbilical Vein Endothelium Cells (HUVECs). Pronuciferine was extracted from plumula nelumbinis. The experiments were performed in HUVECs in vitro. Cell-morphology was observed by light microscope. Cells viability was assessed by MTT assay. NO, tNOS and iNOS were measured by Colorimetry. Cell- morphology and viability weren't affected by Pronuciferine. Pronuciferine significantly increased the level of NO and the activity of tNOS, but had no effect on the activity of iNOS. Pronuciferine increases the level of NO by the enhancement of the activity of tNOS. It may have the protection on endothelial function.

  3. 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.

  4. 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.

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

    NASA Astrophysics Data System (ADS)

    Kutluca, A. Y.; Aydın, A.

    2017-09-01

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

  6. Natural aphrodisiacs.

    PubMed

    Shamloul, Rany

    2010-01-01

    The search for a remedy or a prescription that can enhance sexual function and/or treat male erectile dysfunction has been an obsession throughout known history. Whether it was an Eastern civilization or a Western one, religious or atheist, man's aspiration for a better or best "manhood" has been a history-time goal. This review will discuss the current research done on the most popular natural aphrodisiacs and examine the weight of evidence to support or discourage the use of any of these substances to enhance sexual desire and/or function. Review of the current evidence on the use of natural substances as aphrodisiacs. Efficacy of natural aphrodisiacs in enhancing sexual function in men and women. There is little evidence from literature to recommend the usage of natural aphrodisiacs for the enhancement of sexual desire and/or performance. Data on yohimbine's efficacy does not support the wide use of the drug, which has only mild effects in the treatment of psychogenic ED. Although there's a positive trend towards recommending ginseng as an effective aphrodisiac, however, more in depth studies involving large number of subjects and its mechanism of action are needed before definite conclusions could be reached. Data on the use of natural aphrodisiacs in women is limited. The current body of objective evidence does not support the use of any natural aphrodisiac as an effective treatment for male or female sexual dysfunctions. Potent men and men with ED will continue the search for natural aphrodisiacs despite the current disappointing data on their effectiveness. Care should be taken regarding the fraud addition of sildenafil analogues to natural aphrodisiacs.

  7. 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

  8. 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.

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

    PubMed

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

    2015-08-18

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

  10. Accumbens nNOS Interneurons Regulate Cocaine Relapse.

    PubMed

    Smith, Alexander C W; Scofield, Michael D; Heinsbroek, Jasper A; Gipson, Cassandra D; Neuhofer, Daniela; Roberts-Wolfe, Doug J; Spencer, Sade; Garcia-Keller, Constanza; Stankeviciute, Neringa M; Smith, Rachel J; Allen, Nicholas P; Lorang, Melissa R; Griffin, William C; Boger, Heather A; Kalivas, Peter W

    2017-01-25

    Relapse to drug use can be initiated by drug-associated cues. The intensity of cue-induced relapse is correlated with the induction of transient synaptic potentiation (t-SP) at glutamatergic synapses on medium spiny neurons (MSNs) in the nucleus accumbens core (NAcore) and requires spillover of glutamate from prefrontal cortical afferents. We used a rodent self-administration/reinstatement model of relapse to show that cue-induced t-SP and reinstated cocaine seeking result from glutamate spillover, initiating a metabotropic glutamate receptor 5 (mGluR5)-dependent increase in nitric oxide (NO) production. Pharmacological stimulation of mGluR5 in NAcore recapitulated cue-induced reinstatement in the absence of drug-associated cues. Using NO-sensitive electrodes, mGluR5 activation by glutamate was shown to stimulate NO production that depended on activation of neuronal nitric oxide synthase (nNOS). nNOS is expressed in ∼1% of NAcore neurons. Using a transgene strategy to express and stimulate designer receptors that mimicked mGluR5 signaling through Gq in nNOS interneurons, we recapitulated cue-induced reinstatement in the absence of cues. Conversely, using a transgenic caspase strategy, the intensity of cue-induced reinstatement was correlated with the extent of selective elimination of nNOS interneurons. The induction of t-SP during cued reinstatement depends on activating matrix metalloproteinases (MMPs) and selective chemogenetic stimulation of nNOS interneurons recapitulated MMP activation and t-SP induction (increase in AMPA currents in MSNs). These data demonstrate critical involvement of a sparse population of nNOS-expressing interneurons in cue-induced cocaine seeking, revealing a bottleneck in brain processing of drug-associated cues where therapeutic interventions could be effective in treating drug addiction. Relapse to cocaine use in a rat model is associated with transient increases in synaptic strength at prefrontal cortex synapses in the nucleus

  11. 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

  12. 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

  13. 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

  14. 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

  15. 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

  16. 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

  17. 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

  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. Beer elicits vasculoprotective effects through Akt/eNOS activation.

    PubMed

    Vilahur, Gemma; Casani, Laura; Mendieta, Guiomar; Lamuela-Raventos, Rosa M; Estruch, Ramon; Badimon, Lina

    2014-12-01

    There is controversy regarding the effect of alcohol beverage intake in vascular vasodilatory function in peripheral arteries. The effects of beer intake in coronary vasodilation remain unknown. We investigated whether regular beer intake (alcohol and alcohol-free) protects against hypercholesterolaemia-induced coronary endothelial dysfunction and the mechanisms behind this effect. Pigs were fed 10 days: (i) a Western-type hypercholesterolaemic diet (WD); (ii) WD+low-dose beer (12·5 g alcohol/day); (iii) WD+moderate-dose beer (25 g alcohol/day); or (iv) WD+moderate-dose alcohol-free-beer (0·0 g alcohol/day). Coronary responses to endothelium-dependent vasoactive drugs (acetylcholine: receptor mediated; calcium ionophore-A23189: nonreceptor mediated), endothelium-independent vasoactive drug (SNP) and L-NMMA (NOS-antagonist) were evaluated in the LAD coronary artery by flow Doppler. Coronary Akt/eNOS activation, MCP-1 expression, oxidative DNA damage and superoxide production were assessed. Lipid profile, lipoproteins resistance to oxidation and urinary isoxanthohumol concentration were evaluated. Alcoholic and nonalcoholic beer intake prevented WD-induced impairment of receptor- and non-receptor-operated endothelial-dependent coronary vasodilation. All animals displayed a similar vasodilatory response to SNP and L-NMMA blunted all endothelial-dependent vasorelaxation responses. Haemodynamic parameters remained unchanged. Coronary arteries showed lower DNA damage and increased Akt/eNOS axis activation in beer-fed animals. Animals taking beer showed HDL with higher antioxidant capacity, higher LDL resistance to oxidation and increased isoxanthohumol levels. Weight, lipids levels, liver enzymes and MCP-1 expression were not affected by beer intake. Non-alcoholic-related beer components protect against hyperlipemia-induced coronary endothelial dysfunction by counteracting vascular oxidative damage and preserving the Akt/eNOS pathway. Light-to-moderate beer

  20. 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

  1. 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.

  2. 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…

  3. 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…

  4. 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…

  5. 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…

  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. 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…

  8. A modified citrulline assay of NOS activity in rat brain homogenates does not detect direct effects of halothane on the kinetics of NOS activity.

    PubMed

    Tagliente, T M; Craddock Royal, B; Beasley, J; Maayani, S

    1997-09-05

    An improved citrulline radioassay of nitric oxide synthase (NOS) activity was developed to study the direct effects of the volatile anesthetic (VA) halothane on the enzyme kinetics of neuronal NOS derived from different regions of the rat central nervous system (CNS). The Vmax of NOS in both soluble cytosolic and membrane bound particulate fractions varied across regions with greatest activity in the cerebellum and least in the spinal cord. In contrast, the Km was not different across regions or in the cytosolic and particulate fractions. Halothane at 0.5, 1, 2 or 3% delivered concentration had no effect on either kinetic parameter of NOS in any of the regions studied indicating that the VAs have no direct effects on NOS activity.

  9. 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.

  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. 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

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

    NASA Astrophysics Data System (ADS)

    Rivas, Michael Gerald

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

  13. Impact of eNOS-Dependent Oxidative Stress on Endothelial Function and Neointima Formation

    PubMed Central

    Suvorava, Tatsiana; Nagy, Nadine; Pick, Stephanie; Lieven, Oliver; Rüther, Ulrich; Dao, Vu Thao-Vi; Fischer, Jens W.; Weber, Martina

    2015-01-01

    Abstract Aims: Vascular oxidative stress generated by endothelial NO synthase (eNOS) was observed in experimental and clinical cardiovascular disease, but its relative importance for vascular pathologies is unclear. We investigated the impact of eNOS-dependent vascular oxidative stress on endothelial function and on neointimal hyperplasia. Results: A dimer-destabilized mutant of bovine eNOS where cysteine 101 was replaced by alanine was cloned and introduced into an eNOS-deficient mouse strain (eNOS-KO) in an endothelial-specific manner. Destabilization of mutant eNOS in cells and eNOS-KO was confirmed by the reduced dimer/monomer ratio. Purified mutant eNOS and transfected cells generated less citrulline and NO, respectively, while superoxide generation was enhanced. In eNOS-KO, introduction of mutant eNOS caused a 2.3–3.7-fold increase in superoxide and peroxynitrite formation in the aorta and myocardium. This was completely blunted by an NOS inhibitor. Nevertheless, expression of mutant eNOS in eNOS-KO completely restored maximal aortic endothelium-dependent relaxation to acetylcholine. Neointimal hyperplasia induced by carotid binding was much larger in eNOS-KO than in mutant eNOS-KO and C57BL/6, while the latter strains showed comparable hyperplasia. Likewise, vascular remodeling was blunted in eNOS-KO only. Innovation: Our results provide the first in vivo evidence that eNOS-dependent oxidative stress is unlikely to be an initial cause of impaired endothelium-dependent vasodilation and/or a pathologic factor promoting intimal hyperplasia. These findings highlight the importance of other sources of vascular oxidative stress in cardiovascular disease. Conclusion: eNOS-dependent oxidative stress is unlikely to induce functional vascular damage as long as concomitant generation of NO is preserved. This underlines the importance of current and new therapeutic strategies in improving endothelial NO generation. Antioxid. Redox Signal. 23, 711–723. PMID:25764009

  14. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2017-06-01

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

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed

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

    2015-01-01

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

  18. Nature's Code

    NASA Astrophysics Data System (ADS)

    Hill, Vanessa J.; Rowlands, Peter

    2008-10-01

    We propose that the mathematical structures related to the `universal rewrite system' define a universal process applicable to Nature, which we may describe as `Nature's code'. We draw attention here to such concepts as 4 basic units, 64- and 20-unit structures, symmetry-breaking and 5-fold symmetry, chirality, double 3-dimensionality, the double helix, the Van der Waals force and the harmonic oscillator mechanism, and our explanation of how they necessarily lead to self-aggregation, complexity and emergence in higher-order systems. Biological concepts, such as translation, transcription, replication, the genetic code and the grouping of amino acids appear to be driven by fundamental processes of this kind, and it would seem that the Platonic solids, pentagonal symmetry and Fibonacci numbers have significant roles in organizing `Nature's code'.

  19. Inducible NOS mediates CNP-induced relaxation of intestinal myofibroblasts

    PubMed Central

    Chen, Yishi; Chitapanarux, Taned; Wu, Jianfeng; Soon, Russell K.; Melton, Andrew C.

    2013-01-01

    Contraction of intestinal myofibroblasts (IMF) contributes to the development of strictures and fistulas seen in inflammatory bowel disease, but the mechanisms that regulate tension within these cells are poorly understood. In this study we investigated the role of nitric oxide (NO) signaling in C-type natriuretic peptide (CNP)-induced relaxation of IMF. We found that treatment with ODQ, a soluble guanylyl cyclase (sGC) inhibitor, or NG-nitro-l-arginine (l-NNA) or NG-monomethyl-l-arginine (l-NMMA), inhibitors of NO production, all impaired the relaxation of human and mouse IMF in response to CNP. ODQ, l-NNA, and l-NMMA also prevented CNP-induced elevations in cGMP concentrations, and l-NNA or l-NMMA blocked CNP-induced decreases in myosin light phosphorylation. IMF isolated from transgenic mice deficient in inducible nitric oxide synthase (iNOS) had reduced relaxation responses to CNP compared with IMF from control mice and were insensitive to the effects of ODQ, l-NNA, and l-NMMA on CNP treatment. Together these data indicate that stimulation of sGC though NO produced by iNOS activation is required for maximal CNP-induced relaxation in IMF. PMID:23348803

  20. 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.

  1. 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.

  2. Paraphilia NOS, nonconsent: not ready for the courtroom.

    PubMed

    Frances, Allen; First, Michael B

    2011-01-01

    Sexually violent predators (SVP) constitute a serious potential risk to public safety, especially when they are released after too short a prison sentence. Twenty states and the federal government have developed a seemingly convenient way to reduce this risk. They have passed statutes that allow for the involuntary (often lifetime) psychiatric commitment of mentally disordered sexual offenders after prison time is up. In three separate cases, the Supreme Court has accepted the constitutionality of this procedure, but only if the offender's dangerousness is caused by a mental disorder and is not a manifestation of simple criminality. The idea that paraphilic rape should be an official category in the psychiatric diagnostic manual has been explicitly rejected by Diagnostic and Statistical Manual of Mental Disorders (DSM)-III, DSM-III-R, DSM-IV, and, recently, DSM-5. Despite this, paraphilia NOS, nonconsent, is still frequently used by mental health evaluators in SVP cases to provide a mental disorder diagnosis that legitimizes psychiatric commitment and makes it appear constitutional. This commentary will show how the diagnosis paraphilia NOS, nonconsent, is based on a fundamental misreading of the original intent of the DSM-IV Paraphilia Workgroup and represents a misuse of psychiatry, all in the admittedly good cause of protecting public safety.

  3. eNOS Deficiency Predisposes Podocytes to Injury in Diabetes

    PubMed Central

    Yuen, Darren A.; Stead, Bailey E.; Zhang, Yanling; White, Kathryn E.; Kabir, M. Golam; Thai, Kerri; Advani, Suzanne L.; Connelly, Kim A.; Takano, Tomoko; Zhu, Lei; Cox, Alison J.; Kelly, Darren J.; Gibson, Ian W.; Takahashi, Takamune; Harris, Raymond C.

    2012-01-01

    Endothelial nitric oxide synthase (eNOS) deficiency may contribute to the pathogenesis of diabetic nephropathy in both experimental models and humans, but the underlying mechanism is not fully understood. Here, we studied two common sequelae of endothelial dysfunction in diabetes: glomerular capillary growth and effects on neighboring podocytes. Streptozotocin-induced diabetes increased glomerular capillary volume in both C57BL/6 and eNOS−/− mice. Inhibiting the vascular endothelial growth factor receptor attenuated albuminuria in diabetic C57BL/6 mice but not in diabetic eNOS−/− mice, even though it inhibited glomerular capillary enlargement in both. In eNOS−/− mice, an acute podocytopathy and heavy albuminuria occurred as early as 2 weeks after inducing diabetes, but treatment with either captopril or losartan prevented these effects. In vitro, serum derived from diabetic eNOS−/− mice augmented actin filament rearrangement in cultured podocytes. Furthermore, conditioned medium derived from eNOS−/− glomerular endothelial cells exposed to both high glucose and angiotensin II activated podocyte RhoA. Taken together, these results suggest that the combined effects of eNOS deficiency and hyperglycemia contribute to podocyte injury, highlighting the importance of communication between endothelial cells and podocytes in diabetes. Identifying mediators of this communication may lead to the future development of therapies targeting endothelial dysfunction in albuminuric individuals with diabetes. PMID:22997257

  4. 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.

  5. 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.

  6. Compensatory lung growth in NOS3 knockout mice suggests synthase isoform redundancy.

    PubMed

    Pokall, Stefan; Maldonado, Arturo R; Klanke, Charles A; Katayama, Shuichi; Morris, Lee M; Vuletin, Jose F; Lim, Foong-Yen; Crombleholme, Timothy M

    2012-04-01

    Nitric oxide synthase 3 (NOS3) produces nitric oxide (NO) in endothelial cells, which stimulates cyclic guanosine monophosphate (cGMP) production and thereby mediates pulmonary vasodilation. Inhibition of cGMP enzymatic cleavage by sildenafil might be involved in lung growth stimulating processes in pulmonary hypoplasia. The aim of this study was to discover insights into the transcriptional regulation of NOS3 in a mouse model of compensatory lung growth (CLG). CLG was studied in wild type animals (WT) and NOS3 knockout mice (NOS3-/-) by dry weight, DNA, and protein quantification as well as relative quantification of NOS mRNA. All assessments were done on adult female mice, 10 days after left pneumonectomy (PNX) or sham thoracotomy. Weight ratios of right NOS3-/- lungs were no different than controls. There was a compensatory increase in DNA and a noncompensating increase in protein ratios in NOS3-/- mice compared with controls. Pharmacological knockdown with the pan-NOS inhibitor l-NAME (nitro-arginine methyl ester) reduced CLG by only 8% compared with the d-NAME treated control mice. Relative quantification of lung mRNA revealed no up-regulation of NOS3 expression in WT lungs after PNX, but NOS3-/- lungs showed a 2.6-fold higher inducible NOS2 expression compared with shams. These data suggest that NOS3 loss of function alone does not impair CLG in mice, possibly because of redundancy mechanisms involving NOS2. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  7. 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.

  8. 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.

  9. 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

    .... DPR-32 and DPR-37, issued to Virginia Electric and Power Company (the licensee), for operation of NAPS... COMMISSION [Docket Nos. 50-338 and 50-339, Docket Nos. 50-280 and 50-281, NRC- 2010-0283] Virginia Electric and Power Company North Anna Power Station, Unit Nos. 1 and 2 Surry Power Station, Unit Nos. 1 and 2...

  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 fibers

    Treesearch

    Craig M. Clemons; Daniel F. Caulfield

    2005-01-01

    The term “natural fibers” covers a broad range of vegetable, animal, and mineral fibers. However, in the composites industry, it usually refers to wood fiber and agrobased bast, leaf, seed, and stem fibers. These fibers often contribute greatly to the structural performance of the plant and, when used in plastic composites, can provide significant reinforcement. Below...

  12. 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.

  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. 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

  16. 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…

  17. 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…

  18. 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.

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

    NASA Astrophysics Data System (ADS)

    Burniston, Amy Lucinda

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

  20. Timed and targeted differential regulation of nitric oxide synthase (NOS) and anti-NOS genes by reward conditioning leading to long-term memory formation.

    PubMed

    Korneev, Sergei A; Straub, Volko; Kemenes, Ildikó; Korneeva, Elena I; Ott, Swidbert R; Benjamin, Paul R; O'Shea, Michael

    2005-02-02

    In a number of neuronal models of learning, signaling by the neurotransmitter nitric oxide (NO), synthesized by the enzyme neuronal NO synthase (nNOS), is essential for the formation of long-term memory (LTM). Using the molluscan model system Lymnaea, we investigate here whether LTM formation is associated with specific changes in the activity of members of the NOS gene family: Lym-nNOS1, Lym-nNOS2, and the antisense RNA-producing pseudogene (anti-NOS). We show that expression of the Lym-nNOS1 gene is transiently upregulated in cerebral ganglia after conditioning. The activation of the gene is precisely timed and occurs at the end of a critical period during which NO is required for memory consolidation. Moreover, we demonstrate that this induction of the Lym-nNOS1 gene is targeted to an identified modulatory neuron called the cerebral giant cell (CGC). This neuron gates the conditioned feeding response and is an essential part of the neural network involved in LTM formation. We also show that the expression of the anti-NOS gene, which functions as a negative regulator of nNOS expression, is downregulated in the CGC by training at 4 h after conditioning, during the critical period of NO requirement. This appears to be the first report of the timed and targeted differential regulation of the activity of a group of related genes involved in the production of a neurotransmitter that is necessary for learning, measured in an identified neuron of known function. We also provide the first example of the behavioral regulation of a pseudogene.

  1. 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.

  2. Role of muscular eNOS in skeletal arteries: Endothelium-independent hypoxic vasoconstriction of the femoral artery is impaired in eNOS-deficient mice.

    PubMed

    Kim, Hae Jin; Yoo, Hae Young; Lin, Hai Yue; Oh, Goo Taeg; Zhang, Yin Hua; Kim, Sung Joon

    2016-09-01

    We previously reported that hypoxia augments α-adrenergic contraction (hypoxic vasoconstriction, HVC) of skeletal arteries in rats. The underlying mechanism may involve hypoxic inhibition of endothelial nitric oxide synthase (eNOS) expressed in skeletal arterial myocytes (16). To further explore the novel role of muscular eNOS in the skeletal artery, we compared HVC in femoral arteries (FAs) from eNOS knockout (KO) mice with that from wild-type (WT) and heterozygous (HZ) mice. Immunohistochemical assays revealed that, in addition to endothelia, eNOS is also expressed in the medial layer of FAs, albeit at a much lower level. However, the medial eNOS signal was not evident in HZ FAs, despite strong expression in the endothelium; similar observations were made in WT carotid arteries (CAs). The amplitude of contraction induced by 1 μM phenylephrine (PhE) was greater in HZ than in WT FAs. Hypoxia (3% Po2) significantly augmented PhE-induced contraction in WT FAs but not in HZ or KO FAs. No HVC was observed in PhE-pretreated WT CAs. The NOS inhibitor nitro-l-arginine methyl ester (0.1 mM) also augmented PhE contraction in endothelium-denuded WT FAs but not in WT CAs. Inhibitors specific to neuronal NOS and inducible NOS did not augment PhE-induced contraction of WT FAs. NADPH oxidase 4 (NOX4) inhibitor (GKT137831, 5 μM), but not NOX2 inhibitor (apocynin, 100 μM), suppressed HVC. Consistent with the role of reactive oxygen species (ROS), HVC was also inhibited by pretreatment with tiron or polyethylene glycol-catalase. Taken together, these data suggest that the eNOS expressed in smooth muscle cells in FAs attenuates α-adrenergic vasoconstriction; this suppression is alleviated under hypoxia, which potentiates vasoconstriction in a NOX4/ROS-dependent mechanism. Copyright © 2016 the American Physiological Society.

  3. Haplotypes of NOS3 Gene Polymorphisms in Dilated Cardiomyopathy

    PubMed Central

    Matsa, Lova Satyanarayana; Rangaraju, Advithi; Vengaldas, Viswamitra; Latifi, Mona; Jahromi, Hossein Mehraban; Ananthapur, Venkateshwari; Nallari, Pratibha

    2013-01-01

    Dilated Cardiomyopathy (DCM) is characterized by systolic dysfunction, followed by heart failure necessitating cardiac transplantation. The genetic basis is well established by the identification of mutations in sarcomere and cytoskeleton gene/s. Modifier genes and environmental factors are also considered to play a significant role in the variable expression of the disease, hence various mechanisms are implicated and one such mechanism is oxidative stress. Nitric Oxide (NO), a primary physiological transmitter derived from endothelium seems to play a composite role with diverse anti-atherogenic effects as vasodilator. Three functional polymorphisms of endothelial nitric oxide synthase (NOS3) gene viz., T-786C of the 5′ flanking region, 27bp VNTR in intron4 and G894T of exon 7 were genotyped to identify their role in DCM. A total of 115 DCM samples and 454 controls were included. Genotyping was carried out by PCR -RFLP method. Allelic and genotypic frequencies were computed in both control & patient groups and appropriate statistical tests were employed. A significant association of TC genotype (T-786C) with an odds ratio of 1.74, (95% CI 1.14 - 2.67, p = 0.01) was observed in DCM. Likewise the GT genotypic frequency of G894T polymorphism was found to be statistically significant (OR 2.10, 95% CI 1.34–3.27, p = 0.0011), with the recessive allele T being significantly associated with DCM (OR 1.64, 95% CI 1.18 - 2.30, p = 0.003). The haplotype carrying the recessive alleles of G894T and T-786C, C4bT was found to exhibit 7 folds increased risk for DCM compared to the controls. Hence C4bT haplotype could be the risk haplotype for DCM. Our findings suggest the possible implication of NOS3 gene in the disease phenotype, wherein NOS3 may be synergistically functioning in DCM associated heart failure via the excessive production of NO in cardiomyocytes resulting in decreased myocardial contractility and systolic dysfunction, a common feature of DCM

  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. 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

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

    PubMed

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

    2015-06-24

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

  7. Heat Shock Protein-70 Inducers and iNOS Inhibitors as Therapeutics to Ameliorate Hemorrhagic Shock

    DTIC Science & Technology

    2004-09-01

    RTO-MP-HFM-109 P28 - 1 Heat Shock Protein-70 Inducers and iNOS Inhibitors as Therapeutics to Ameliorate Hemorrhagic Shock Juliann G. Kiang...mechanisms are still not fully understood, it has been shown that nitric oxide (NO) overproduction and inducible nitric oxide synthase (iNOS...tissues and leukotriene B4 (LTB4) generation increases. In a hemorrhage/resuscitation- induced injury model, iNOS, cyclooxygenase-2, and CD14 are all

  8. Nos3 protects against systemic inflammation and myocardial dysfunction in murine polymicrobial sepsis.

    PubMed

    Bougaki, Masahiko; Searles, Robert J; Kida, Kotaro; Yu, JiaDe; Buys, Emmanuel S; Ichinose, Fumito

    2010-09-01

    NO has been implicated in the pathogenesis of septic shock. However, the role of NO synthase 3 (NOS3) during sepsis remains incompletely understood. Here, we examined the impact of NOS3 deficiency on systemic inflammation and myocardial dysfunction during peritonitis-induced polymicrobial sepsis. Severe polymicrobial sepsis was induced by colon ascendens stent peritonitis (CASP) in wild-type (WT) and NOS3-deficient (NOS3KO) mice. NOS3KO mice exhibited shorter survival time than did WT mice after CASP. NOS3 deficiency worsened systemic inflammation assessed by the expression of inflammatory cytokines in the lung, liver, and heart. Colon ascendens stent peritonitis markedly increased the number of leukocyte infiltrating the liver and heart in NOS3KO but not in WT mice. The exaggerated systemic inflammation in septic NOS3KO mice was associated with more marked myocardial dysfunction than in WT mice 22 h after CASP. The detrimental effects of NOS3 deficiency on myocardial function after CASP seem to be caused by impaired Ca handling of cardiomyocytes. The impaired Ca handling of cardiomyocytes isolated from NOS3KO mice subjected to CASP was associated with depressed mitochondrial ATP production, a determinant of the Ca cycling capacity of sarcoplasmic reticulum Ca-ATPase. The NOS3 deficiency-induced impairment of the ability of mitochondria to produce ATP after CASP was at least in part attributable to reduction in mitochondrial respiratory chain complex I activity. These observations suggest that NOS3 protects against systemic inflammation and myocardial dysfunction after peritonitis-induced polymicrobial sepsis in mice.

  9. Genetic Deletion of NOS3 Increases Lethal Cardiac Dysfunction Following Mouse Cardiac Arrest

    PubMed Central

    Beiser, David G.; Orbelyan, Gerasim A.; Inouye, Brendan T.; Costakis, James G.; Hamann, Kimm J.; McNally, Elizabeth M.; Hoek, Terry L. Vanden

    2010-01-01

    Study Aims Cardiac arrest mortality is significantly affected by failure to obtain return of spontaneous circulation (ROSC) despite cardiopulmonary resuscitation (CPR). Severe myocardial dysfunction and cardiovascular collapse further affects mortality within hours of initial ROSC. Recent work suggests that enhancement of nitric oxide (NO) signaling within minutes of CPR can improve myocardial function and survival. We studied the role of NO signaling on cardiovascular outcomes following cardiac arrest and resuscitation using endothelial NO synthase knockout (NOS3-/-) mice. Methods Adult female wild-type (WT) and NOS3-/- mice were anesthetized, intubated, and instrumented with left-ventricular pressure-volume catheters. Cardiac arrest was induced with intravenous potassium chloride. CPR was performed after 8 min of untreated arrest. ROSC rate, cardiac function, whole-blood nitrosylhemoglobin (HbNO) concentrations, heart NOS3 content and phosphorylation (p-NOS3), cyclic guanosine monophosphate (cGMP), and phospho-troponin I (p-TnI) were measured. Results Despite equal quality CPR, NOS3-/- mice displayed lower rates of ROSC compared to WT (47.6% [10/21] vs. 82.4% [14/17], p<0.005). Among ROSC animals, NOS3-/- versus WT mice exhibited increased left-ventricular dysfunction and 120 min mortality. Prior to ROSC, myocardial effectors of NO signaling including cGMP and p-TnI were decreased in NOS3-/- vs. WT mice (p<0.05). Following ROSC in WT mice, significant NOS3-dependent increases in circulating HbNO were seen by 120 min. Significant increases in cardiac p-NOS3 occurred between end-arrest and 15 min post-ROSC, while total NOS3 content was increased by 120 min post-ROSC (p<0.05). Conclusions Genetic deletion of NOS3 decreases ROSC rate and worsens post-ROSC left-ventricular function. Poor cardiovascular outcomes are associated with differences in NOS3-dependent myocardial cGMP signaling and circulating NO metabolites. PMID:20951489

  10. NOS3 protects against systemic inflammation and myocardial dysfunction in murine polymicrobial sepsis

    PubMed Central

    Bougaki, Masahiko; Searles, Robert J.; Kida, Kotaro; De Yu, Jia; Buys, Emmanuel S.; Ichinose, Fumito

    2013-01-01

    Nitric oxide (NO) has been implicated in the pathogenesis of septic shock. However, the role of NO synthase 3 (NOS3) during sepsis remains incompletely understood. Here, we examined impact of NOS3 deficiency on systemic inflammation and myocardial dysfunction during peritonitis-induced polymicrobial sepsis. Severe polymicrobial sepsis was induced by colon ascendens stent peritonitis (CASP) in wild-type (WT) and NOS3-deficient (NOS3KO) mice. NOS3KO mice exhibited shorter survival time than did WT mice after CASP. NOS3 deficiency worsened systemic inflammation assessed by the expression of inflammatory cytokines in the lung, liver, and heart. CASP markedly increased the number of leukocyte infiltrating the liver and heart in NOS3KO but not in WT mice. The exaggerated systemic inflammation in septic NOS3KO mice was associated with more marked myocardial dysfunction than in WT mice 22h after CASP. The detrimental effects of NOS3-deficiency on myocardial function after CASP appear to be caused by impaired Ca2+ handling of cardiomyocytes. The impaired Ca2+ handling of cardiomyocytes isolated from NOS3KO mice subjected to CASP was associated with depressed mitochondrial ATP production, a determinant of the Ca2+ cycling capacity of sarcoplasmic reticulum (SR) Ca2+-ATPase. The NOS3-deficiency-induced impairment of the ability of mitochondria to produce ATP after CASP was at least in part attributable to reduction in mitochondrial respiratory chain complex I activity. These observations suggest that NOS3 protects against systemic inflammation and myocardial dysfunction after peritonitis-induced polymicrobial sepsis in mice. PMID:19997049

  11. 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…

  12. 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…

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

    ERIC Educational Resources Information Center

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

    2011-01-01

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

  14. 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…

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

    ERIC Educational Resources Information Center

    Kaya, Ebru; Erduran, Sibel

    2016-01-01

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

  16. 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…

  17. 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…

  18. 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…

  19. 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…

  20. 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.

  1. Natural thermodynamics

    NASA Astrophysics Data System (ADS)

    Annila, Arto

    2016-02-01

    The principle of increasing entropy is derived from statistical physics of open systems assuming that quanta of actions, as undividable basic build blocks, embody everything. According to this tenet, all systems evolve from one state to another either by acquiring quanta from their surroundings or by discarding quanta to the surroundings in order to attain energetic balance in least time. These natural processes result in ubiquitous scale-free patterns: skewed distributions that accumulate in a sigmoid manner and hence span log-log scales mostly as straight lines. Moreover, the equation for least-time motions reveals that evolution is by nature a non-deterministic process. Although the obtained insight in thermodynamics from the notion of quanta in motion yields nothing new, it accentuates that contemporary comprehension is impaired when modeling evolution as a computable process by imposing conservation of energy and thereby ignoring that quantum of actions are the carriers of energy from the system to its surroundings.

  2. [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.

  3. 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

  4. 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.

  5. 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.

  6. Natural fibers

    Treesearch

    Craig M. Clemons

    2010-01-01

    The term “natural fibers” covers a broad range of vegetable, animal, and mineral fibers. However, in the composites industry, it usually refers to wood fiber and plant-based bast, leaf, seed, and stem fibers. These fibers often contribute greatly to the structural performance of the plant and, when used in plastic composites, can provide significant reinforcement....

  7. 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.

  8. 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...

  9. 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.

  10. 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;…

  11. 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…

  12. 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,…

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

    ERIC Educational Resources Information Center

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

    2013-01-01

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

  15. 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,…

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

    ERIC Educational Resources Information Center

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

    2013-01-01

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

  17. Addressing the Nature of Science in Preservice Science Teacher Preparation Programs: Science Educator Perceptions

    ERIC Educational Resources Information Center

    Backhus, DeWayne A.; Thompson, Kenneth Wayne

    2006-01-01

    The nature of science (NOS) has a prominent role among the national science education content standards at all grade levels, K-12. Results from a national survey of collegiate science educators indicate the perception that the greatest contributors to preservice teachers' understanding of the nature of science were science methods courses,…

  18. The role of endothelial nitric oxide synthase (eNOS) in the pathogenesis of sinonasal polyps.

    PubMed

    Muluk, N Bayar; Arikan, O K; Atasoy, P; Kiliç, R; Yalçinozan, E Tuna

    2014-01-01

    The pathogenesis of sinonasal polyps has not been known completely. We investigated the role of endothelial Nitric Oxide Synthase (eNOS) in the pathogenesis of sinonasal polyps. Study group (Groups 1-3) consisted of nasal polyp samples of patients with sinonasal polyps; and control group consisted of inferior turbinate samples of patients without nasal polyp. In Group 1: 14 specimens from ethmoid sinus; in Group 2: 10 specimens from nasal cavity; in Group 3: 10 specimens from maxillary sinus; and in Group 4 (Control): 9 specimens from inferior turbinate were included. By immunohistochemical staining technique, eNOS Positivity Index in mucosal layers; and in the inflammatory cells were assessed. eNOS Positivity Index was higher at apical layer of epithelium; and perivascular and glandular parts of subepithelial layer. As a rate of mononuclear cells increased, eNOS positivity increased at basal part of epithelium. In eNOS Positivity Index of mononuclear cells increased ones, eNOS values also increased at glands of subepithelial layer. In nasal cavity, eNOS positivity index of all cells was significantly higher than that of the control group. Increased eNOS all cells positivity index values were seen with decreased glandular and endothelial eNOS values. In all cells group, fibroblasts were seen beside the mononuclear cells. It was observed that eNOS was not expressed in PMNC (mainly neutrophils), growing more in acute inflammatory process; and was expressed in MNCs and all cells group with fibroblasts which were the cells of chronic inflammatory process. Especially MNCs and fibroblasts may play a role in the polyp formation process. In males and in patients with longer polyp duration, eNOS values decreased. We concluded that eNOS Positivity Index was higher at apical layer of epithelium; and perivascular and glandular parts of subepithelial layer. eNOS plays role in vascular dilatation, increases in vascular permeability; increases in nasal secretion due to glandular

  19. 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.

  20. Identification of chicken eNOS gene and differential expression in highland versus lowland chicken breeds.

    PubMed

    Peng, J F; Ling, Y; Gou, W Y; Zhang, H; Wu, C X

    2012-09-01

    Nitric oxide (NO), an endothelium-derived relaxing factor, is synthesized from l-arginine by endothelial nitric oxide synthase (eNOS) in the endothelium. The objective of the present study was to preliminarily illuminate the expression of the eNOS gene in hypoxic adaptation of chicken embryonic development. The eNOS expression profiles between the Tibet and Shouguang chickens incubated under both normoxic and hypoxic conditions were detected by TaqMan real-time PCR. In this study, the chicken eNOS gene was found by both in silico cloning and RACE approaches. From the eNOS gene, we obtained a 3,310-bp mRNA sequence and a 10,666-bp DNA sequence and discovered that it was located on chicken chromosome 2 and had 7 unique transcripts. eNOS mRNA was detected in abundant amounts in some chick embryo organs (i.e., heart, liver, chorio-allantoic membrane, and lung), and expressed stably with the lowest levels in the brain. We observed that when exposed to hypoxia (13% O(2)) different embryo organ tissues had various sensitivities to hypoxia as determined by their eNOS expression profiles. Compared with the Shouguang chicken, the eNOS expression in the Tibet chicken was higher in the lung and liver, lower in the heart, and similar in the brain. In chorio-allantoic membranes, eNOS expression was higher in the Shouguang chicken than the Tibet chicken under hypoxic conditions, but not markedly different under normoxic conditions. The differences of eNOS expression between the 2 breeds may be relative to the hypoxic adaptation ability in Tibet chickens during embryonic development. This work will provide reference for future studies on the role of eNOS in hypoxic adaptation and response.

  1. Changing standard chow diet promotes vascular NOS dysfunction in Dahl S rats

    PubMed Central

    Spradley, Frank T.; Ho, Dao H.; Kang, Kyu-Tae; Pollock, Jennifer S.

    2012-01-01

    We hypothesized that vascular nitric oxide synthase (NOS) function and expression is differentially regulated in adult Dahl salt-sensitive rats maintained on Teklad or American Institutes of Nutrition (AIN)-76A standard chow diets from 3 to 16 wk old. At 16 wk old, acetylcholine (ACh)-mediated vasorelaxation and phenylephrine (PE)-mediated vasoconstriction in the presence and absence of NOS inhibitor, Nω-nitro-l-arginine methyl ester (l-NAME), was assessed in small-resistance mesenteric arteries and aortas. Rats maintained on either diet throughout the study had similar responses to ACh and PE in the presence or absence of l-NAME in both vascular preparations. We reasoned that changing from one diet to another as adults may induce vascular NOS dysfunction. In the absence of l-NAME, small arteries from Teklad-fed rats switched to AIN-76 diet and vice versa had similar responses to ACh and PE. Small-arterial NOS function was maintained in rats switched to AIN-76A from Teklad diet, whereas NOS function in response to ACh and PE was lost in the small arteries from rats changed to Teklad from AIN-76A diet. This loss of NOS function was echoed by reduced expression of NOS3, as well as phosphorylated NOS3. The change in NOS phenotype in the small arteries was observed without changes in blood pressure. Aortic responses to ACh or PE in the presence or absence of l-NAME were similar in all diet groups. These data indicate that changing standard chow diets leads to small arterial NOS dysfunction and reduced NOS signaling, predisposing Dahl salt-sensitive rats to vascular disease. PMID:22031779

  2. Arginase inhibition restores NOS coupling and reverses endothelial dysfunction and vascular stiffness in old rats

    PubMed Central

    Kim, Jae Hyung; Bugaj, Lukasz J.; Oh, Young Jun; Bivalacqua, Trinity J.; Ryoo, Sungwoo; Soucy, Kevin G.; Santhanam, Lakshmi; Webb, Alanah; Camara, Andre; Sikka, Gautam; Nyhan, Daniel; Shoukas, Artin A.; Ilies, Monica; Christianson, David W.; Champion, Hunter C.

    2009-01-01

    There is increasing evidence that upregulation of arginase contributes to impaired endothelial function in aging. In this study, we demonstrate that arginase upregulation leads to endothelial nitric oxide synthase (eNOS) uncoupling and that in vivo chronic inhibition of arginase restores nitroso-redox balance, improves endothelial function, and increases vascular compliance in old rats. Arginase activity in old rats was significantly increased compared with that shown in young rats. Old rats had significantly lower nitric oxide (NO) and higher superoxide (O2−) production than young. Acute inhibition of both NOS, with NG-nitro-l-arginine methyl ester, and arginase, with 2(S)-amino- 6-boronohexanoic acid (ABH), significantly reduced O2− production in old rats but not in young. In addition, the ratio of eNOS dimer to monomer in old rats was significantly decreased compared with that shown in young rats. These results suggest that eNOS was uncoupled in old rats. Although the expression of arginase 1 and eNOS was similar in young and old rats, inducible NOS (iNOS) was significantly upregulated. Furthermore, S-nitrosylation of arginase 1 was significantly elevated in old rats. These findings support our previously published finding that iNOS nitrosylates and activates arginase 1 (Santhanam et al., Circ Res 101: 692–702, 2007). Chronic arginase inhibition in old rats preserved eNOS dimer-to-monomer ratio and significantly reduced O2− production and enhanced endothelial-dependent vasorelaxation to ACh. In addition, ABH significantly reduced vascular stiffness in old rats. These data indicate that iNOS-dependent S-nitrosylation of arginase 1 and the increase in arginase activity lead to eNOS uncoupling, contributing to the nitroso-redox imbalance, endothelial dysfunction, and vascular stiffness observed in vascular aging. We suggest that arginase is a viable target for therapy in age-dependent vascular stiffness. PMID:19661445

  3. 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.

  4. Coordinated induction of iNOS-VEGF-KDR-eNOS after resveratrol consumption: a potential mechanism for resveratrol preconditioning of the heart.

    PubMed

    Das, Samarjit; Alagappan, Vijay K T; Bagchi, Debasis; Sharma, Hari S; Maulik, Nilanjana; Das, Dipak K

    2005-01-01

    Existing evidence indicates that resveratrol, a red wine and grape-derived polyphenolic antioxidant, can pharmacologically precondition the heart in a nitric oxide (NO)-dependent manner. To further explore the role of NO in resveratrol-mediated cardioprotection, the induction for the expression of the potential molecular targets of NO including VEGF and KDR as well as iNOS and eNOS were examined by Western blot analysis and immunohistochemistry. Two groups of rats were studied, one group of animals was fed resveratrol for 7 days while the other group was given water only. After 1, 3, 5 and 7 days, the rats were sacrificed and the expression of the proteins was examined by Western blot analysis. Western blot detected an overexpression of iNOS and VEGF within 24 h of resveratrol treatment while the induction of KDR was not increased until after 3 days and eNOS expression after 5 days of resveratrol treatment. These expressions were further increased after 7 days of resveratrol treatment, when the rats were sacrificed for the isolated working heart preparation. Resveratrol provided cardioprotection as evidenced by superior post-ischemic ventricular recovery, reduced myocardial infarct size and decreased number of apoptotic cardiomyocytes. Immunohistochemistry was performed in the hearts at baseline, and at the end of 30-min ischemia/2-h reperfusion. The hearts obtained from resveratrol-treated rats revealed enhanced expression for iNOS, eNOS and VEGF and KDR compared to control hearts at the end of reperfusion. The results of this study demonstrate that resveratrol leads to a coordinated upregulation of iNOS-VEGF-KDR-eNOS, which is likely to play a role in resveratrol-mediated cardioprotection.

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

    NASA Astrophysics Data System (ADS)

    Kötter, Mario; Hammann, Marcus

    2017-08-01

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

  6. 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

  7. 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.

  8. 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...

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

    USDA-ARS?s Scientific Manuscript database

    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...

  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. 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.

  13. A downregulation of nNOS is associated to dysmotility evoked by lipopolysaccharide in rabbit duodenum.

    PubMed

    Grasa, L; Arruebo, M P; Plaza, M A; Murillo, M D

    2008-09-01

    Alterations in gastrointestinal motility have been reported in response to endotoxin. The effects of lipopolysaccharide (LPS) on motility have been attributed to several substances, including prostaglandins and nitric oxide. The aim of this study was to investigate the expression and the contribution of NOS and COX enzymes to the local effect of LPS on ACh-evoked contractions in rabbit duodenum. The ACh evoked contractions were inhibited by LPS in longitudinal and circular muscles of duodenum. L-NNA, aminoguanidine, ODQ, indomethacin, and NS-398 but not NPLA antagonized the inhibitory effect of LPS. Western blot analysis showed protein bands of 155, 130, 70 and 72 kDa for nNOS, iNOS, COX-1 and COX-2 respectively in rabbit duodenum. All of these isoforms were expressed constitutively and only the nNOS was reduced in the presence of LPS. Expression of nNOS, iNOS, COX-1 and COX-2 was detected by inmunohistochemistry in the smooth muscle layers and in the neurons of the myenteric ganglia of rabbit duodenum. In conclusion, LPS locally administered reduces the contractility of rabbit duodenum and a downregulation of nNOS is associated to this effect. The iNOS, COX-1 and COX-2 were expressed constitutively but their expression was not modified by LPS.

  14. Umbilical Cord Blood NOS1 as a Potential Biomarker of Neonatal Encephalopathy.

    PubMed

    Lei, Jun; Paules, Cristina; Nigrini, Elisabeth; Rosenzweig, Jason M; Bahabry, Rudhab; Farzin, Azadeh; Yang, Samuel; Northington, Frances J; Oros, Daniel; McKenney, Stephanie; Johnston, Michael V; Graham, Ernest M; Burd, Irina

    2017-01-01

    There are no definitive markers to aid in diagnosis of neonatal encephalopathy (NE). The purpose of our study was (1) to identify and evaluate the utility of neuronal nitric oxide synthase (NOS1) in umbilical cord blood as a NE biomarker and (2) to identify the source of NOS1 in umbilical cord blood. This was a nested case-control study of neonates >35 weeks of gestation. ELISA for NOS1 in umbilical cord blood was performed. Sources of NOS1 in umbilical cord were investigated by immunohistochemistry, western blot, ELISA, and quantitative PCR. Furthermore, umbilical cords of full-term neonates were subjected to 1% hypoxia ex vivo. NOS1 was present in umbilical cord blood and increased in NE cases compared with controls. NOS1 was expressed in endothelial cells of the umbilical cord vein, but not in artery or blood cells. In ex vivo experiments, hypoxia was associated with increased levels of NOS1 in venous endothelial cells of the umbilical cord as well as in ex vivo culture medium. This is the first study to investigate an early marker of NE. NOS1 is elevated with hypoxia, and further studies are needed to investigate it as a valuable tool for early diagnosis of neonatal brain injury.

  15. Relationships between caveolae and eNOS: everything in proximity and the proximity of everything.

    PubMed

    Goligorsky, Michael S; Li, Hong; Brodsky, Sergey; Chen, Jun

    2002-07-01

    Caveolae, flask-shaped invaginations of the plasma membrane occupying up to 30% of cell surface in capillaries, represent a predominant location of endothelial nitric oxide synthase (eNOS) in endothelial cells. The caveolar coat protein caveolin forms high-molecular-weight, Triton-insoluble complexes through oligomerization mediated by interactions between NH2-terminal residues 61-101. eNOS is targeted to caveolae by cotranslational N-myristoylation and posttranslational palmitoylation. Caveolin-1 coimmunoprecipitates with eNOS; interaction with eNOS occurs via the caveolin-1 scaffolding domain and appears to result in the inhibition of NOS activity. The inhibitory conformation of eNOS is reversed by the addition of excess Ca2+/calmodulin and by Akt-induced phosphorylation of eNOS. Here, we shall dissect the system using the classic paradigm of a reflex loop: 1) the action of afferent elements, such as fluid shear stress and its putative caveolar sensor, on caveolae; 2) the ways in which afferent signals may affect the central element, the activation of the eNOS-nitric oxide system; and 3) several resultant well-established and novel physiologically important effector mechanisms, i.e., vasorelaxation, angiogenesis, membrane fluidity, endothelial permeability, deterrance of inflammatory cells, and prevention of platelet aggregation.

  16. Anaphylactic shock depends on PI3K and eNOS-derived NO

    PubMed Central

    Cauwels, Anje; Janssen, Ben; Buys, Emmanuel; Sips, Patrick; Brouckaert, Peter

    2006-01-01

    Anaphylactic shock is a sudden, life-threatening allergic reaction associated with severe hypotension. Platelet-activating factor (PAF) is implicated in the cardiovascular dysfunctions occurring in various shock syndromes, including anaphylaxis. Excessive production of the vasodilator NO causes inflammatory hypotension and shock, and it is generally accepted that transcriptionally regulated inducible iNOS is responsible for this. Nevertheless, the contribution of NO to PAF-induced shock or anaphylactic shock is still ambiguous. We studied PAF and anaphylactic shock in conscious mice. Surprisingly, hyperacute PAF shock depended entirely on NO, produced not by inducible iNOS, but by constitutive eNOS, rapidly activated via the PI3K pathway. Soluble guanylate cyclase (sGC) is generally regarded as the principal vasorelaxing mediator of NO. Nevertheless, although methylene blue partially prevented PAF shock, neither 1H-[1,2,4]oxadiazole[4,3-a]quinoxalin-1-one (ODQ) nor sGCα1 deficiency did. Also, in 2 different models of active systemic anaphylaxis, inhibition of NOS, PI3K, or Akt or eNOS deficiency provided complete protection. In contrast to the unsubstantiated paradigm that only excessive iNOS-derived NO underlies cardiovascular collapse in shock, our data strongly support the unexpected concept that eNOS-derived NO is the principal vasodilator in anaphylactic shock and define eNOS and/or PI3K or Akt as new potential targets for treating anaphylaxis. PMID:16886062

  17. 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, 2007...

  18. 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...

  19. 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).

  20. 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.