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Sample records for agregado natural nos

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

    ERIC Educational Resources Information Center

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

    2015-01-01

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

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

    ERIC Educational Resources Information Center

    Aflalo, Ester

    2014-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2016-05-01

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

  4. 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…

  5. 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.

  6. Improving Chilean In-Service Elementary Teachers' Understanding of Nature of Science Using Self-Contained NOS and Content-Embedded Mini-Courses

    ERIC Educational Resources Information Center

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

    2014-01-01

    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…

  7. 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'…

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

    NASA Astrophysics Data System (ADS)

    Faikhamta, Chatree

    2013-04-01

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

  9. 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,…

  10. 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

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

    NASA Astrophysics Data System (ADS)

    Al-Saidi, Ahmed Mohammad

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

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

    SciTech Connect

    Lopez, M.J.; Jellinek, J.

    1995-12-31

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

  13. Natural Orifice Surgery (NOS) Using StomaphyX™ for Repair of Gastric Leaks after Bariatric Revisions

    PubMed Central

    2008-01-01

    Gastric leaks represent serious complications of bariatric surgery. With the increasing popularity and performance of bariatric procedures, the incidence of leaks and associated complications are expected to increase. Minimally invasive natural orifice surgery represents a novel and promising approach to gastric leak management, especially for morbidly obese patients who are at much higher risk from open or laparoscopic surgical procedures. The present article reports two cases of the safe and successful use of the EndoGastric Solutions StomaphyX™ device to alter the flow of gastric contents and repair gastric leaks resulting from bariatric revision surgery. Both patients were at a high risk and could not undergo another open or laparoscopic surgery to correct the leaks that were not healing. The StomaphyX procedures lasted approximately 30 min, were performed without any complications, and resulted in the resolution of the gastric leaks in both patients. PMID:18438622

  14. 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.

  15. The NOS Challenge

    ERIC Educational Resources Information Center

    Quigley, Cassie; Buck, Gayle; Akerson, Valarie

    2011-01-01

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

  16. 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…

  17. The naturally occurring biflavonoid, ochnaflavone, inhibits LPS-induced iNOS expression, which is mediated by ERK1/2 via NF-kappaB regulation, in RAW264.7 cells.

    PubMed

    Suh, Seok-Jong; Chung, Tae-Wook; Son, Min-Jung; Kim, Sung-Hoon; Moon, Tae Chul; Son, Kun Ho; Kim, Hyun Pyo; Chang, Hyeun Wook; Kim, Cheorl-Ho

    2006-03-15

    Ochnaflavone (OC), a naturally occurring biflavonoid with anti-inflammatory activity [S.J. Lee, J.H. Choi, H.W. Chang, S.S. Kang, H.P. Kim. Life Sci. 57(6), 1995, 551-558], was isolated from Lonicera japonica and its effects on inducible nitric oxide synthase (iNOS) gene expression was examined in RAW264.7 cells. U0126, an inhibitor of the extracellular signal-regulated kinase (ERK), significantly down-regulated lipopolysaccharide (LPS)-induced iNOS expression and promoter activity. Transactivation of LPS-stimulated NF-kappaB was inhibited by U0126. These results suggest that the transcription factor NF-kappaB is involved in ERK-mediated iNOS regulation and that activation of the Ras/ERK pathway contributes to the induction of iNOS expression in RAW264.7 cells in response to LPS. OC treatment inhibited the production of nitric oxide in a concentration-dependent manner and also blocked the LPS-induced expression of iNOS. These inhibitory effects were associated with reduced ERK1/2 activity. OC inhibited the phosphorylation of c-Jun NH2-terminal kinase (JNK) and p38 mitogen-activated protein kinase. The findings herein show that the inhibition of LPS-induced ERK1/2 activation may be a contributing factor to the main mechanisms by which OC inhibits RAW264.7. To clarify the mechanistic basis for its ability to inhibit iNOS induction, we examined the effect of OC on the transactivation of the iNOS gene by luciferase reporter activity using the -1588 flanking region. OC potently suppressed reporter gene activity. We also report here, for the first time, that LPS-induced iNOS expression was abolished by OC in RAW264.7 cells through by blocking the inhibition of transcription factor NF-kappaB binding activities. These activities are associated with the down-regulation of inhibitor kappaB (IkappaB) kinase (IKK) activity by OC (6 microM), thus inhibiting LPS-induced phosphorylation as well as the degradation of IkappaBalpha. These findings suggest that the inhibition of LPS

  18. The dual role of iNOS in cancer.

    PubMed

    Vannini, Federica; Kashfi, Khosrow; Nath, Niharika

    2015-12-01

    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

  19. 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

  20. 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.

  1. Cytokine and iNOS profiles in lymph nodes of dogs naturally infected with Leishmania infantum and their association with the parasitic DNA load and clinical and histopathological features.

    PubMed

    de Vasconcelos, Tassia Cristina Bello; Doyen, Noelle; Cavaillon, Jean-Marc; Bruno, Sávio Freire; de Campos, Monique Paiva; de Miranda, Luisa Helena Monteiro; Madeira, Maria de Fátima; Belo, Vinícius Silva; Figueiredo, Fabiano Borges

    2016-08-30

    In South America, visceral leishmaniasis is a zoonotic disease with severe evolution characteristics in humans, and dogs are its main reservoir. In this context, this study aimed to evaluate the clinical status of dogs from a Brazilian endemic area naturally, at Barra Mansa municipality, infected with Leishmania infantum, in conjunction with their histopathological profile and, in order to determine possible markers of susceptibility or resistance to the disease, parasitic DNA load, cytokine and iNOS mRNA expression profiles were investigated in lymph nodes. High levels of IFN-ɣ and IL-6 mRNA were detected. Both IFN-ɣ and IL-6 mRNA were associated with disorganization of the corticomedullary region. IFN-ɣ and TNF-α mRNA were associated with the absence of follicular hyperplasia. The regulatory pathway was remarkable with IL-10 mRNA detection and its significant association with the severity of the disease. Plasmacytosis and sinus histiocytosis were associated with high loads of parasitic DNA, but there was no significant association between the parasite DNA load and animal clinical alterations. Since high parasitic loads were found in animals with or without symptoms, clinical examination cannot be considered as a criterion for disease susceptibility assessment. PMID:27523930

  2. 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,…

  3. 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…

  4. Sustained hypertension despite endothelial-specific eNOS rescue in eNOS-deficient mice.

    PubMed

    Suvorava, Tatsiana; Stegbauer, Johannes; Thieme, Manuel; Pick, Stephanie; Friedrich, Sebastian; Rump, Lars C; Hohlfeld, Thomas; Kojda, Georg

    2015-03-13

    The aim of the study was to evaluate the possible contribution of non-endothelial eNOS to the regulation of blood pressure (BP). To accomplish this, a double transgenic strain expressing eNOS exclusively in the vascular endothelium (eNOS-Tg/KO) has been generated by endothelial-specific targeting of bovine eNOS in eNOS-deficient mice (eNOS-KO). Expression of eNOS was evaluated in aorta, myocardium, kidney, brain stem and skeletal muscle. Organ bath studies revealed a complete normalization of aortic reactivity to acetylcholine, phenylephrine and the NO-donors in eNOS-Tg/KO. Function of eNOS in resistance arteries was demonstrated by acute i.v. infusion of acetylcholine and the NOS-inhibitor L-NAME. Acetylcholine decreased mean arterial pressure in all strains but eNOS-KO responded significantly less sensitive as compared eNOS-Tg/KO and C57BL/6. Likewise, acute i.v. L-NAME application elevated mean arterial pressure in C57BL/6 and eNOS-Tg/KO, but not in eNOS-KO. In striking contrast to these findings, mean, systolic and diastolic BP in eNOS-Tg/KO remained significantly elevated and was similar to values of eNOS-KO. Chronic oral treatment with L-NAME increased BP to the level of eNOS-KO only in C57BL/6, but had no effect on hypertension in eNOS-KO and eNOS-Tg/KO. Taken together, functional reconstitution of eNOS in the vasculature of eNOS-KO not even partially lowered BP. These data suggest that the activity of eNOS expressed in non-vascular tissue might play a role in physiologic BP regulation. PMID:25680465

  5. Particle Physics Masterclass as a Context for Learning about NOS

    NASA Astrophysics Data System (ADS)

    Wadness, Michael

    2011-04-01

    This research addresses the question: Do secondary school science students attending the U.S. Particle Physics Masterclass change their view of the nature of science (NOS)? The U.S. Particle Physics Masterclass is a national physics outreach program run by QuarkNet, in which high school physics students gather at a local research institution for one day to learn about particle physics and the scientific enterprise. Student activities include introductory lectures in particle physics, laboratory tours, analysis of actual data from CERN, and the discussion of their findings in a conference-like atmosphere. Although there are a number of outreach programs involving scientists in K-12 education, very few of them have been formally evaluated to determine if they provide adequate learning of NOS. Therefore, the significance of this study is that it investigates the claim that science outreach programs may be designed to address science literacy, specifically as a context for explicit NOS instruction.

  6. 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…

  7. 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…

  8. Association Between Experienced Teachers' NOS Implementation and Reform-Based Practices

    NASA Astrophysics Data System (ADS)

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

    2013-11-01

    The assertion that general reform-based science teaching practices (GRBSTPs) can facilitate nature of science (NOS) instruction has been mentioned in the literature, but rigorous and transparent empirical substantiation for this claim has not been made. This investigation empirically demonstrates an association between thirteen experienced teachers' NOS implementation practices and their GRBSTPs. While effectively implementing GRBSTPs does not ensure the NOS will be taught, the findings show that these practices are associated with high levels of NOS instruction. In this study, teachers who implemented higher levels of reform-based practices were also observed to enact more instances of planned and spontaneous effective NOS instruction. Furthermore, these teachers were more likely to recognize and capitalize on NOS teaching opportunities when they unexpectedly arose in the context of their GRBSTPs. Just as NOS understanding must be assessed when determining factors associated with teachers' NOS implementation, teachers' GRBSTPs should also be empirically and transparently established to ensure they do not mask or confound other factors associated with NOS implementation.

  9. 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…

  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 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…

  12. 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.

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

    ERIC Educational Resources Information Center

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

    2010-01-01

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

  14. 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…

  15. 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,…

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

    ERIC Educational Resources Information Center

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

    2015-01-01

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

  17. 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.

  18. 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

  19. 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…

  20. 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…

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

    ERIC Educational Resources Information Center

    Hansson, Lena; Leden, Lotta

    2016-01-01

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

  2. 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…

  3. 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…

  4. Changing Elementary Teachers' Views of the NOS: Effective Strategies for Science Methods Courses.

    ERIC Educational Resources Information Center

    Dickinson, Valarie L.; Abd-El-Khalick, Fouad S.; Lederman, Norman G.

    This study assesses the influence of a set of activities developed based on preservice elementary science teachers' conceptions of the nature of science (NOS). It also compares the effectiveness of these activities when implemented using two approaches. The first approach was a direct explicit approach while the second featured additional…

  5. 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…

  6. 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 scientists to…

  7. 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,…

  8. Preservice Elementary Science Teachers' Connections among Aspects of NOS: Toward a Consistent, Overarching Framework

    ERIC Educational Resources Information Center

    Ozgelen, Sinan; Hanuscin, Deborah L.; Yilmaz-Tuzun, Ozgul

    2013-01-01

    This study examined the connections elementary preservice science teachers made among various aspects of nature of science (NOS). Totally, 45 preservice science teachers who were enrolled in the Laboratory Application in Science II course participated in the study. The course provided meaningful and practical inquiry-based experiences, as well as…

  9. Association between Experienced Teachers' NOS Implementation and Reform-Based Practices

    ERIC Educational Resources Information Center

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

    2013-01-01

    The assertion that general reform-based science teaching practices (GRBSTPs) can facilitate nature of science (NOS) instruction has been mentioned in the literature, but rigorous and transparent empirical substantiation for this claim has not been made. This investigation empirically demonstrates an association between thirteen experienced…

  10. 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…

  11. Revisiting the Translation of Nature of Science Understandings into Instructional Practice: Teachers' nature of science pedagogical content knowledge

    NASA Astrophysics Data System (ADS)

    Wahbeh, Nader; Abd-El-Khalick, Fouad

    2014-02-01

    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 practice. Nineteen teachers participated in an intensive, 6-week NOS course, which concluded with teachers developing plans to address NOS in their classrooms. Next, 6 participants were observed as they implemented their instructional plans. Data sources included pretest, posttest, and delayed-test NOS assessments, classroom observations, and several teacher-generated artifacts. The NOS course was effective in helping teachers develop informed NOS conceptions and retain those understandings 5 months after its conclusion. Teachers met with challenges and successes as they attempted to address NOS instructionally. The translation of NOS conceptions into practice was primarily mediated by the very nature of teachers' newly acquired NOS understandings, which were situated within the science contents, contexts, and experiences in which they were developed (i.e. the NOS course); thus, limiting participants' abilities to transfer their understandings into novel contexts and contents. The results helped build a model of the sources of science teachers' pedagogical content knowledge for teaching about NOS in content-rich contexts.

  12. 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…

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

    ERIC Educational Resources Information Center

    Sahin, Canan Tunc; Koksal, Mustafa Serdar

    2010-01-01

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

  14. 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…

  15. An evolutionarily ancient NO synthase (NOS) in shrimp.

    PubMed

    Wu, Chun-Hung; Siva, Vinu S; Song, Yen-Ling

    2013-11-01

    Nitric oxide (NO) is a well known essential molecule that is involved in multiple functions such as neuron transduction, cardiac disease, immune responses, etc.; nitric oxide synthase (NOS) is a critical enzyme that catalyzes the synthesis of it. A very few crustacean NOS molecules were biochemically characterized so far. In the present study, we cloned and characterized a NOS cDNA from haemocytes of tiger shrimp (Penaeus monodon) (PmNOS). The full-length of PmNOS cDNA contained 3997 bp, including a 5'UTR of 249 bp, ORF of 3582 bp and a 3'UTR of 166 bp. The putative peptide was 1193 amino acid residues in length, with an estimated molecular weight of 134.7 kDa and pI 6.7. Structurally, PmNOS contained oxygenase and reductase domains at N-terminal and C-terminal, respectively, and connected with a calmodulin binding motif. The deduced amino acid sequence of PmNOS shared 98% identical to the Chinese shrimp (Fenneropenaeus chinensis) NOS. Phylogenetically, PmNOS clustered with invertebrate NOS, but not clustered with iNOS, eNOS or nNOS found in vertebrates. PmNOS mRNA was expressed in many tissues or organs including thoracic and ventral nerves, midgut, gill, eyestalk, haemocytes, subcuticular epithelium and heart, but not found in hepatopancreas, muscle and lymphoid organ. But there was no significant difference in PmNOS mRNA expression after stimulation with LPS either by different concentration or time course or against CpG-ODN 2006. The enzyme activities of rPmNOS or crude homogenates from different tissues were detected, and were shown its highest activity in thoracic and ventral nerves, moderate in midgut and haemocytes but the lowest activity were seen in muscle. The addition of NOS antibody against NADPH binding domain leads to less activity which suggested that NADPH was an essential cofactor for PmNOS catalytic activity. The calcium dependency of PmNOS was ascertained using calmodulin inhibitor, Trifluroperazine. To confirm the population of haemocyte which

  16. 15 CFR Supplement Nos. 3-4 to Part... - [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-01-01

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  17. 15 CFR Supplement Nos. 3-4 to Part... - [Reserved

    Code of Federal Regulations, 2013 CFR

    2013-01-01

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  18. 15 CFR Supplement Nos. 3-4 to Part... - [Reserved

    Code of Federal Regulations, 2012 CFR

    2012-01-01

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  19. 15 CFR Supplement Nos. 3-4 to Part... - [Reserved

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    2014-01-01

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  20. 15 CFR Supplement Nos. 3-4 to Part... - [Reserved

    Code of Federal Regulations, 2011 CFR

    2011-01-01

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  1. 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.

  2. Mechanisms and Consequences of eNOS Dysfunction in Hypertension

    PubMed Central

    Li, Qiang; Yon, Ji-Youn; Cai, Hua

    2016-01-01

    Reduced nitric oxide (NO) bioavailability contributes to endothelial dysfunction and hypertension. The endothelial isoform of NO synthase (eNOS) is responsible for the production of NO within endothelium. Loss of eNOS cofactor tetrahydrobiopterin to initial increase in oxidative stress leads to uncoupling of eNOS, in which the enzyme produces superoxide anion rather than NO, further substantiating oxidative stress to induce vascular pathogenesis. The current review focuses on recent advances on the molecular mechanisms and consequences of eNOS dysfunction in hypertension, and potential novel therapeutic strategies restoring eNOS function to treat hypertension. PMID:25882860

  3. 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.

  4. NOS knockout or inhibition but not disrupting PSD-95-NOS interaction protect against ischemic brain damage.

    PubMed

    Kleinschnitz, Christoph; Mencl, Stine; Kleikers, Pamela Wm; Schuhmann, Michael K; G López, Manuela; Casas, Ana I; Sürün, Bilge; Reif, Andreas; Schmidt, Harald Hhw

    2016-09-01

    Promising results have been reported in preclinical stroke target validation for pharmacological principles that disrupt the N-methyl-D-aspartate receptor-post-synaptic density protein-95-neuronal nitric oxide synthase complex. However, post-synaptic density protein-95 is also coupled to potentially neuroprotective mechanisms. As post-synaptic density protein-95 inhibitors may interfere with potentially neuroprotective mechanisms and sufficient validation has often been an issue in translating basic stroke research, we wanted to close that gap by comparing post-synaptic density protein-95 inhibitors with NOS1(-/-) mice and a NOS inhibitor. We confirm the deleterious role of NOS1 in stroke both in vivo and in vitro, but find three pharmacological post-synaptic density protein-95 inhibitors to be therapeutically ineffective. PMID:27354091

  5. 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 to be…

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

    ERIC Educational Resources Information Center

    Posnanski, Tracy J.

    2010-01-01

    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…

  7. 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'…

  8. 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…

  9. Specifying PDD-NOS: A Comparison of PDD-NOS, Asperger Syndrome, and Autism

    ERIC Educational Resources Information Center

    Walker, Darlene R.; Thompson, Ann; Zwaigenbaum, Lonnie; Goldberg, Jeremy; Bryson, Susan E.; Mahoney, William J.; Strawbridge, Christina P.; Szatmari, Peter

    2004-01-01

    Objective: To describe the clinical characteristics of children given a diagnosis of pervasive developmental disorder-not otherwise specified (PDD-NOS) by expert clinicians and to compare these to the clinical characteristics of children given a diagnosis of autism and Asperger syndrome (AS). Method: Two hundred sixteen children with autism, 33…

  10. 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.

  11. 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.

  12. 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…

  13. 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,…

  14. 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…

  15. 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…

  16. 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…

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

    ERIC Educational Resources Information Center

    Bilica, Kimberly

    2012-01-01

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

  18. 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…

  19. 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…

  20. 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…

  1. How the Nature of Science Is Presented to Elementary Students in Science Read-Alouds

    ERIC Educational Resources Information Center

    Rivera, Seema

    2013-01-01

    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…

  2. Elementary Teachers' Pedagogical Content Knowledge for Teaching the Nature of Science

    ERIC Educational Resources Information Center

    Hanuscin, Deborah L.; Lee, Michele H.; Akerson, Valarie L.

    2011-01-01

    Although teacher educators have achieved some success in improving teachers' understanding of the nature of science (NOS), helping teachers teach NOS has proved a much greater challenge. Currently, there are few examples in the literature of teachers who effectively teach NOS, and fewer still that rely on student outcomes as a measure of teachers'…

  3. Effects of Luteolin on Liver, Kidney and Brain in Pentylentetrazol-Induced Seizures: Involvement of Metalloproteinases and NOS Activities

    PubMed Central

    Birman, Hüsniye; Dar, Kadriye Akgün; Kapucu, Ayşegül; Acar, Samet; Üzüm, Gülay

    2012-01-01

    Objective: Flavonoids are an important group of recognized antioxidants in plants. Luteolin (LUT) is a natural flavonoid in the plant kingdom. This study was aimed to investigate the effects of the LUT in the liver, kidney and brain of pentylentetrazol (PTZ)-induced seizure and the relationship between nitric oxide synthases (iNOS, eNOS) and matrix metalloproteinases (MMP2, MMP9). Materials and Methods: LUT (10 mg/kg) was given intraperitoneally during two weeks prior to seizure induction. A single dose PTZ 80 mg/kg i.p. was administered and seizures were observed and evaluated with regard to latency, frequency and stage for one hour. Results: Seizure frequen cy after PTZ administration was significantly decreased in LUT pretreated rats (p<0.05). An increase of immunhistochemical reactions of iNOS and MMP2, but a decrease of eNOS activity, were observed in rat hippocampus and peripheral tissues during the PTZ induced seizures. LUT pretreatment reversed the iNOS and MMP2 activity to the control levels and significantly increased the eNOS activity (p<0.001). Conclusion: LUT seems to have an effective role in reducing the seizure frequency and a protective role on peripheral organ injury in animal models of seizure. The protective effect of LUT in seizures and the seizure induced peripheral tissue damage warrant further investigations. PMID:25206993

  4. Expression of zebrafish nos2b surrounds oral cavity.

    PubMed

    Poon, Kar-Lai; Richardson, Michael; Korzh, Vladimir

    2008-06-01

    Inducible nitric oxide synthase (NOS2) catalyzes the production of nitric oxide (NO), and is one of the factors establishing innate immunity. In zebrafish, Nos2 is represented by nos2a and nos2b. Here, we report the cloning and expression pattern of the zebrafish nos2b gene, which does not seem to participate in induced immune response. nos2b was mapped to zebrafish linkage group 15. The spatial and temporal expression pattern of nos2b in embryonic zebrafish was analyzed by whole-mount in situ hybridization. nos2b is expressed constitutively in two primordia located along the ventral midline. The first group of cells contributes to the neurohypophysis. Initially at the level of the ventral hindbrain, the second group of cells migrates closely with the thyroid primordium to its final position at the basihyal by 3 dpf. Thus, the analysis of expression pattern of nos2b reveals complex morphogenetic movements resulting in its expression surrounding the oral cavity.

  5. Simple reversible molecular dynamics algorithms for Nosé-Hoover chain dynamics

    NASA Astrophysics Data System (ADS)

    Jang, Seogjoo; Voth, Gregory A.

    1997-12-01

    Reversible algorithms for Nosé-Hoover chain (NHC) dynamics are developed by simple extensions of Verlet-type algorithms: leap frog, position Verlet, and velocity Verlet. Tests for a model one dimensional harmonic oscillator show that they generate proper canonical distributions and are stable even with a large time step. Using these algorithms, the effects of the Nosé mass and chain length are examined. For a chain length of two, the sampling efficiency is much more sensitive to the Nosé mass than for a longer chain of length four. This indicates that the chain length in general should be longer than two. The noniterative nature of the algorithms allows them to be easily adapted for constraint dynamics. For the most general case where multiple NHC's are coupled to a system with constraints, a correction of the first Nosé acceleration is required, which is derived from the continuity equation on a constrained hypersurface of the phase space. Tests for model systems of two and three coupled harmonic oscillators with one normal mode constrained show that these algorithms, in combination with the corrected dynamical equations, sample the canonical distributions for the unconstrained degrees of freedom.

  6. 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

  7. 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.

  8. 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…

  9. 78 FR 32622 - Endangered Species; File Nos. 17557 and 17273

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-31

    ... National Ocean Service Marine Forensic Lab (NOS Lab) , 219 Fort Johnson Road, Charleston, SC 29412 (File No... to take marine mammal and endangered species parts for purposes of scientific research. DATES... taking, importing, and exporting of endangered and threatened species (50 CFR parts 222-226). The NOS...

  10. 15 CFR Supplement Nos. 2-3 to Part... - [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-01-01

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

  11. 15 CFR Supplement Nos. 2-3 to Part... - [Reserved

    Code of Federal Regulations, 2011 CFR

    2011-01-01

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

  12. 15 CFR Supplement Nos. 2-3 to Part... - [Reserved

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 15 Commerce and Foreign Trade 2 2012-01-01 2012-01-01 false Nos. Supplement Nos. 2-3 to Part 716 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS INITIAL AND...

  13. 15 CFR Supplement Nos. 2-3 to Part... - [Reserved

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 15 Commerce and Foreign Trade 2 2013-01-01 2013-01-01 false Nos. Supplement Nos. 2-3 to Part 716 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS INITIAL AND...

  14. 15 CFR Supplement Nos. 2-3 to Part... - [Reserved

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 15 Commerce and Foreign Trade 2 2014-01-01 2014-01-01 false Nos. Supplement Nos. 2-3 to Part 716 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS INITIAL AND...

  15. Magnetic circular dichroism spectroscopic characterization of the NOS-like protein from Geobacillus stearothermophilus (gsNOS).

    PubMed

    Kinloch, Ryan D; Sono, Masanori; Sudhamsu, Jawahar; Crane, Brian R; Dawson, John H

    2010-03-01

    Nitric oxide synthase (NOS) catalyzes the NADPH- and O(2)-dependent oxidation of l-arginine (l-Arg) to nitric oxide (NO) and citrulline via an N(G)-hydroxy-l-arginine (NHA) intermediate. Mammalian NOSs have been studied quite extensively; other eukaryotes and some prokaryotes appear to express NOS-like proteins comparable to the oxygenase domain of mammalian NOSs. In this study, a recombinant NOS-like protein from the thermostable bacterium Geobacillus stearothermophilus (gsNOS) has been characterized using magnetic circular dichroism (MCD) and UV-Vis absorption spectroscopic techniques. Spectral comparisons of ligand complexes (with O(2), NO and CO) of substrate-bound (l-Arg or NHA) gsNOS, including the key oxyferrous complex studied at -50 degrees C in cryogenic mixed solvents, with analogous mammalian NOS complexes indicate overall spectroscopic similarities between gsNOS and mammalian NOSs. However, more detailed spectral comparisons reflect subtle structural differences between gsNOS and mammalian NOSs. This may be due to an incomplete tetrahydrobiopterin (BH(4))-binding site and low BH(4)-binding affinity, which may become even lower in the presence of cryosolvent in gsNOS. Although BH(4)-binding may be altered, gsNOS appears to require the pterin for NO production since formation of the stable ferric-NO product complex was only observed when excess BH(4) (>150muM) over gsNOS was present upon single turnover reaction in which O(2) was bubbled into dithionite-reduced NHA-bound protein solution at -35 degrees C or -50 degrees C. PMID:20110129

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

    ERIC Educational Resources Information Center

    Hanuscin, Deborah L.

    2013-01-01

    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…

  17. 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. PMID:26499181

  18. Protein Inhibitor of NOS1 Plays a Central Role in the Regulation of NOS1 Activity in Human Dilated Hearts

    PubMed Central

    Roselló-Lletí, Esther; Tarazón, Estefanía; Ortega, Ana; Gil-Cayuela, Carolina; Carnicer, Ricardo; Lago, Francisca; González-Juanatey, Jose Ramón; Portolés, Manuel; Rivera, Miguel

    2016-01-01

    An essential factor for the production of nitric oxide by nitric oxide synthase 1 (NOS1), major modulator of cardiac function, is the cofactor tetrahydrobiopterin (BH4). BH4 is regulated by GTP cyclohydrolase 1, the rate-limiting enzyme in BH4 biosynthesis which catalyses the formation of dihydroneopterin 3′triphosfate from GTP, producing BH4 after two further steps catalyzed by 6-pyruvoyltetrahydropterin synthase and sepiapterin reductase. However, there are other essential factors involved in the regulation of NOS1 activity, such as protein inhibitor of NOS1 (PIN), calmodulin, heat shock protein 90, and NOS interacting protein. All these molecules have never been analysed in human non-ischemic dilated hearts (DCM). In this study we demonstrated that the upregulation of cardiac NOS1 is not accompanied by increased NOS1 activity in DCM, partly due to the elevated PIN levels and not because of alterations in biopterin biosynthesis. Notably, the PIN concentration was significantly associated with impaired ventricular function, highlighting the importance of this NOS1 activity inhibitor in Ca2+ homeostasis. These results take a central role in the current list of targets for future studies focused on the complex cardiac dysfunction processes through more efficient harnessing of NOS1 signalling. PMID:27481317

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

    ERIC Educational Resources Information Center

    Khishfe, Rola

    2014-01-01

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

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

    ERIC Educational Resources Information Center

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

    2013-01-01

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

  1. 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…

  2. Development of Nature of Science Ideas through Authentic Scientific Research

    ERIC Educational Resources Information Center

    Burgin, Stephen Randall

    2012-01-01

    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…

  3. 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…

  4. Evaluating Knowledge of the Nature of (Whole) Science

    ERIC Educational Resources Information Center

    Allchin, Douglas

    2011-01-01

    I profile here a prospective method for assessing nature of science (NOS) knowledge, as an alternative to VNOS and similar approaches. Questions about cases in contemporary news and from history probe scientific literacy in context. Scoring targets how "well informed" the analysis is, based on identifying relevant NOS information and interpreting…

  5. Two Views about Explicitly Teaching Nature of Science

    ERIC Educational Resources Information Center

    Duschl, Richard A.; Grandy, Richard

    2013-01-01

    Our focus is on the effects that dated ideas about the nature of science (NOS) have on curriculum, instruction and assessments. First we examine historical developments in teaching about NOS, beginning with the seminal ideas of James Conant. Next we provide an overview of recent developments in philosophy and cognitive sciences that have shifted…

  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. β3-Adrenoreceptor stimulation protects against myocardial infarction injury via eNOS and nNOS activation.

    PubMed

    Niu, Xiaolin; Zhao, Lianyou; Li, Xue; Xue, Yusheng; Wang, Bin; Lv, Zongqiang; Chen, Jianghong; Sun, Dongdong; Zheng, Qiangsun

    2014-01-01

    β3-adrenergic receptor (AR) and the downstream signaling, nitric oxide synthase (NOS) isoforms, have been emerged as novel modulators of heart function and even potential therapeutic targets for cardiovascular diseases. However, it is not known whether β3-AR plays cardioprotective effects against myocardial infarction (MI) injury. Therefore, the present study was designed to determine the effects of β3-AR on MI injury and to elucidate the underlying mechanism. MI model was constructed by left anterior descending (LAD) artery ligation. Animals were administrated with β3-AR agonist BRL37344 (BRL) or β3-AR inhibitor SR59230A (SR) respectively at 0.1 mg/kg/hour one day after MI operation. The scar area, cardiac function and the apoptosis of myocardial were assessed by Masson's trichrome stain, echocardiography and TUNEL assay respectively. Western blot analysis was performed to elucidate the expressions of target proteins. β3-AR activation with BRL administration significantly attenuated fibrosis and decreased scar area after MI. Moreover, BRL also preserved heart function, and reduced the apoptosis of cardiomyocyte induced by MI. Furthermore, BRL treatment altered the phosphorylation status of endothelial NOS (eNOS) and increased the expression of neuronal NOS (nNOS). These results suggested that β3-AR stimulation has a substantial effect on recovery of heart function. In addition, the activations of both eNOS and nNOS may be associated with the cardiac protective effects of β3-AR.

  8. 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…

  9. 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

  10. FRONT ELEVATIONS, NOS. 2122 AND 2124 ON THE WEST SIDE ...

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

    FRONT ELEVATIONS, NOS. 2122 AND 2124 ON THE WEST SIDE OF UBER STREET, LOOKING WEST. - 2100 Block North Uber Street (Houses), East & west sides between Diamond Street & Susquehanna Avenue, Philadelphia, Philadelphia County, PA

  11. FRONT ELEVATIONS, NOS. 2123 AND 2125 ON THE EAST SIDE ...

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

    FRONT ELEVATIONS, NOS. 2123 AND 2125 ON THE EAST SIDE OF UBER STREET, LOOKING EAST. - 2100 Block North Uber Street (Houses), East & west sides between Diamond Street & Susquehanna Avenue, Philadelphia, Philadelphia County, PA

  12. Face and emotion recognition in MCDD versus PDD-NOS.

    PubMed

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

    2008-04-01

    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 expressions. Few significant group differences emerged. Children with PDD-NOS demonstrated a more attention-demanding strategy of face processing, and processed neutral faces more similarly to complex patterns whereas children with MCDD showed an advantage for face recognition compared to complex patterns. Results further suggested that any disadvantage in face recognition was related more to the autistic features of the PDD-NOS group rather than characteristics specific to MCDD. No significant group differences emerged for identifying facial expressions.

  13. 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

  14. 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

  15. 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

  16. eNOS Genetic Polymorphisms and Cancer Risk

    PubMed Central

    Gao, Xueren; Wang, Jie; Wang, Wenjun; Wang, Mingxi; Zhang, Jianqiong

    2015-01-01

    Abstract The association between endothelial nitric oxide synthase (eNOS) polymorphisms (intron 4a/b, -786T>C and 894G>T) and cancer risk remains elusive. In addition, no studies focused on their associations with the risk of breast cancer in Chinese Han population. Thus, a meta-analysis was conducted to determine the relationship between eNOS polymorphisms and cancer risk, and then a case–control study in Chinese Han population was performed to assess their associations with breast cancer susceptibility. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of association. The pooled analysis indicated that eNOS intron 4a/b and -786T>C polymorphisms were significantly associated with an increased risk of overall cancer. In subgroup analyses based on cancer type, the significant association was found between eNOS intron 4a/b polymorphism and prostate cancer risk, eNOS -786T>C polymorphism and risk of prostate, bladder and breast cancers, and eNOS 894G>T polymorphism and breast cancer risk. In subgroup analyses based on ethnicity, eNOS intron 4a/b and -786T>C polymorphisms were associated with an increased risk of cancer in Caucasians. In consistent with our meta-analysis results, a case–control study in Chinese Han population showed significant associations of eNOS -786T>C and 894G>T polymorphisms with the increased risk of breast cancer. In addition, stratified analyses based on pathological type showed that eNOS 894G>T polymorphism was only associated with the risk of infiltrative ductal carcinoma. Stratified analyses by tumor stage showed that eNOS -786T>C polymorphism was only associated with the risk of tumor stage III and IV. In conclusion, our meta-analysis and case–control study suggest that eNOS -786T>C and 894G>T polymorphisms are associated with the increased risk of breast cancer. PMID:26131841

  17. 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.

  18. 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.

  19. eNOS-uncoupling in age-related erectile dysfunction.

    PubMed

    Johnson, J M; Bivalacqua, T J; Lagoda, G A; Burnett, A L; 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 (BH(4)) on erectile function in the aged rats. Male Fischer 344 'young' (4-month-old) and 'aged' (19-month-old) rats were treated with a BH(4) 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

  20. 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

  1. 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.

  2. 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.

  3. 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. PMID:20194807

  4. 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…

  5. 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…

  6. 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…

  7. 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

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

    NASA Astrophysics Data System (ADS)

    Yacoubian, Hagop Azad

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

  9. 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.

  10. 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

  11. 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…

  12. 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…

  13. 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…

  14. 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…

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

    ERIC Educational Resources Information Center

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

    2014-01-01

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

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

    PubMed

    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

  17. 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

  18. Developing deeper understandings of nature of science: the impact of a philosophy of science course on preservice science teachers' views and instructional planning

    NASA Astrophysics Data System (ADS)

    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 sequence, in which participants received explicit, reflective NOS instruction. Ten of these participants were also enrolled in a graduate survey POS course. The Views of Nature of Science Questionnaire -- Form C coupled with individual interviews was used to assess participants' NOS views at the beginning and conclusion of the study. Participants' lesson plans and NOS-specific reflection papers were analysed to assess the impact of the POS course on their instructional planning related to, and perceptions of teaching about, NOS. Results indicated that, compared with participants enrolled in the methods courses, the POS course participants developed deeper, more coherent understandings of NOS. Substantially more of these latter participants planned explicit instructional sequences to teach about NOS. Additionally, the POS course participants' discourse regarding NOS progressed from a preoccupation with the technical, to a concern with the practical, and, finally, to a focus on the emancipatory. Their views of teaching about NOS in their future classrooms went beyond the customary discourse of whether pre-college students should or could be taught about NOS, to contemplating changes they needed to bring about in their own teaching behaviour and language to achieve consistency with their newly acquired NOS understandings.

  19. 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.

  20. 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

  1. 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

  2. 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

  3. 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

  4. 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

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

    NASA Astrophysics Data System (ADS)

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

    2016-07-01

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

  6. 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

  7. 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

  8. 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."…

  9. 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

  10. Oblique view of east sides of Facility Nos. 393 and ...

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

    Oblique view of east sides of Facility Nos. 393 and 394, seen from South Avenue looking down Port Royal Street - U.S. Naval Base, Pearl Harbor, Two-Story Storehouses with Ramps, Port Royal Street between Central and South Avenues, Pearl City, Honolulu County, HI

  11. 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

  12. 76 FR 15300 - Endangered Species; File Nos. 16266 and 16291

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-21

    ... National Oceanic and Atmospheric Administration RIN 0648-XA306 Endangered Species; File Nos. 16266 and 16291 AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration... educating the public on shortnose sturgeon life history and the reasons for the species decline....

  13. 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…

  14. 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…

  15. Early Childhood Teachers' Views of Nature of Science: The Influence of Intellectual Levels, Cultural Values, and Explicit Reflective Teaching

    ERIC Educational Resources Information Center

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

    2008-01-01

    This study tracked the influence of explicit reflective instructional methods on cultural values, ethical and intellectual development, and the relationship of these with preservice teachers' views of nature of science (NOS). The researchers used the Views of Nature of Science Form B (VNOS B) to describe NOS views, the Learning Context…

  16. Relationships of Preservice Early Childhood Teachers' Cultural Values, Ethical and Cognitive Developmental Levels, and Views of Nature of Science

    ERIC Educational Resources Information Center

    Akerson, Valarie L.; Buzzelli, Cary A.

    2007-01-01

    This study explored relationships between preservice early childhood teachers' views of nature of science (NOS), cognitive developmental levels, and their cultural values. Using the Views of Nature of Science Questionnaire (VNOS-B) and interviews, we assessed views of NOS. The Learning Context Questionnaire (LCQ) was used to determine the…

  17. 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.

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

    NASA Astrophysics Data System (ADS)

    Deniz, Hasan; Adibelli, Elif

    2015-12-01

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

  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. Contribution of the nos-pdt Operon to Virulence Phenotypes in Methicillin-Sensitive Staphylococcus aureus

    PubMed Central

    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

  1. 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

  2. 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. PMID:26428312

  3. 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.

  4. 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

  5. Formation of nNOS/PSD-95 PDZ dimer requires a preformed beta-finger structure from the nNOS PDZ domain.

    PubMed

    Tochio, H; Mok, Y K; Zhang, Q; Kan, H M; Bredt, D S; Zhang, M

    2000-10-27

    PDZ domains are modular protein units that play important roles in organizing signal transduction complexes. PDZ domains mediate interactions with both C-terminal peptide ligands and other PDZ domains. Here, we used PDZ domains from neuronal nitric oxide synthase (nNOS) and postsynaptic density protein-95 (PSD-95) to explore the mechanism for PDZ-dimer formation. The nNOS PDZ domain terminates with a approximately 30 residue amino acid beta-finger peptide that is shown to be required for nNOS/PSD-95 PDZ dimer formation. In addition, formation of the PDZ dimer requires this beta-finger peptide to be physically anchored to the main body of the canonical nNOS PDZ domain. A buried salt bridge between the beta-finger and the PDZ domain induces and stabilizes the beta-hairpin structure of the nNOS PDZ domain. In apo-nNOS, the beta-finger peptide is partially flexible and adopts a transient beta-strand like structure that is stabilized upon PDZ dimer formation. The flexibility of the NOS PDZ beta-finger is likely to play a critical role in supporting the formation of nNOS/PSD-95 complex. The experimental data also suggest that nNOS PDZ and the second PDZ domain of PSD-95 form a "head-to-tail" dimer similar to the nNOS/syntrophin complex characterized by X-ray crystallography.

  6. 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

  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. Developing views of nature of science in an authentic context: An explicit approach to bridging the gap between nature of science and scientific inquiry

    NASA Astrophysics Data System (ADS)

    Schwartz, Reneé S.; Lederman, Norman G.; Crawford, Barbara A.

    2004-07-01

    Reform efforts emphasize teaching science to promote contemporary views of the nature of science (NOS) and scientific inquiry. Within the framework of situated cognition, the assertion is that engagement in inquiry activities similar to those of scientists provides a learning context conducive to developing knowledge about the methods and activities through which science progresses, and, in turn, to developing desired views of NOS. The inclusion of a scientific inquiry context to teach about NOS has intuitive appeal. Yet, whether the learners are students, teachers, or scientists, the empirical research does not generally support the claim that engaging in scientific inquiry alone enhances conceptions of NOS. We studied developments in NOS conceptions during a science research internship course for preservice secondary science teachers. In addition to the research component, the course included seminars and journal assignments. Interns' NOS views were assessed in a pre/post format using the Views of Nature of Science questionnaire, [VNOS-C] and interviews. Results indicate most interns showed substantial developments in NOS knowledge. Three factors were identified as important for NOS developments during the internship: (1) reflection, (2) context, and (3) perspective. Reflective journal writing and seminars had the greatest impact on NOS views. The science research component provided a context for reflection. The interns' role perspective appeared to impact their abilities to effectively reflect. Interns who assumed a reflective stance were more successful in deepening their NOS conceptions. Those who maintained a scientist's identity were less successful in advancing their NOS views through reflection. In light of these results, we discuss the significance and challenges to teaching about NOS within inquiry contexts.

  9. 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…

  10. 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…

  11. 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…

  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. 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…

  14. Focusing Labs on the Nature of Science

    ERIC Educational Resources Information Center

    Colburn, Alan

    2004-01-01

    Scientific knowledge is tentative and open to revision. This sense of tentativeness, or changeability, is missing in the way textbooks and teachers often portray the nature of science (NOS). Instead, students are left with the impression that the scientific method produces sure knowledge and that they can uncritically accept the knowledge because…

  15. 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…

  16. 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…

  17. 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…

  18. 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…

  19. 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…

  20. 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…

  1. 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…

  2. Teaching Nature of Science Explicitly in a First-Grade Internship Setting

    ERIC Educational Resources Information Center

    Akerson, Valarie L.; Volrich, Morgan L.

    2006-01-01

    This case study focused on a preservice teachers' (Morgan) efforts to explicitly emphasize nature of science (NOS) elements in her first-grade internship classroom. The study assessed the change in first grade students' views of the inferential, tentative, and creative NOS as a result of the explicit instruction. Morgan held appropriate views of…

  3. 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,…

  4. 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…

  5. 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…

  6. Promoting Pre-Service Teachers' Ideas about Nature of Science through Educational Research Apprenticeship

    ERIC Educational Resources Information Center

    Cakmakci, Gultekin

    2012-01-01

    This study suggests a novel approach, which integrates an explicit-reflective nature of science (NOS) instruction into the teachers-as-researchers approach to improve pre-service science teachers' conceptions of NOS. Participants were 48 university fourth-year students in a four-year pre-service science teacher-training program in Turkey. The…

  7. 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…

  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. 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…

  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. 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. Teachers' Willingness to Adopt Nature of Science Activities Following a Physical Science Professional Development

    ERIC Educational Resources Information Center

    Donnelly, Lisa A.; Argyle, Sean

    2011-01-01

    The major science education reform documents emphasize the need for K-12 students to have a robust understanding of nature of science (NOS), and inservice teachers consequently need to develop their NOS teaching repertoires. This study investigated the extent to which science teachers were willing to adopt new strategies and activities for…

  13. 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…

  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. 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

  16. 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

  17. 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

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

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Pyrophoric solids, metals or alloys, n.o.s. 173... Class 1 and Class 7 § 173.187 Pyrophoric solids, metals or alloys, n.o.s. Packagings for pyrophoric solids, metals, or alloys, n.o.s. must conform to the requirements of part 178 of this subchapter at...

  19. 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...

  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. Expression, localization, and regulation of NOS in human mast cell lines: effects on leukotriene production.

    PubMed

    Gilchrist, Mark; McCauley, Scott D; Befus, A Dean

    2004-07-15

    Nitric oxide (NO) is a potent radical produced by nitric oxide synthase (NOS) and has pleiotrophic activities in health and disease. As mast cells (MCs) play a central role in both homeostasis and pathology, we investigated NOS expression and NO production in human MC populations. Endothelial NOS (eNOS) was ubiquitously expressed in both human MC lines and skin-derived MCs, while neuronal NOS (nNOS) was variably expressed in the MC populations studied. The inducible (iNOS) isoform was not detected in human MCs. Both growth factor-independent (HMC-1) and -dependent (LAD 2) MC lines showed predominant nuclear eNOS protein localization, with weaker cytoplasmic expression. nNOS showed exclusive cytoplasmic localization in HMC-1. Activation with Ca(2+) ionophore (A23187) or IgE-anti-IgE induced eNOS phosphorylation and translocation to the nucleus and nuclear and cytoplasmic NO formation. eNOS colocalizes with the leukotriene (LT)-initiating enzyme 5-lipoxygenase (5-LO) in the MC nucleus. The NO donor, S-nitrosoglutathione (SNOG), inhibited, whereas the NOS inhibitor, N(G)-nitro-l-arginine methyl ester (L-NAME), potentiated LT release in a dose-dependent manner. Thus, human MC lines produce NO in both cytoplasmic and nuclear compartments, and endogenously produced NO can regulate LT production by MCs. PMID:15044250

  2. Growth Hormone Effects in Immune Stress: AKT/eNOS Signaling Module in the Cellular Response

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The activation of the constitutive endothelial nitric-oxide synthase (eNOS) and expression of inducible NOS (iNOS) with subsequent nitric oxide production are among the early cellular responses that follow in a systemic exposure of animals to lipopolysaccharide (LPS). Growth hormone (GH) has been sh...

  3. 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. PMID:27164904

  4. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2012-06-01

    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 during their internships to share NOS teaching and assessment ideas and ask questions. Field notes and voice recordings were used to track conversations at focus group settings and videotapes were made of science instruction in each internship setting. None of the preservice teachers had cooperating teachers who taught NOS, yet results showed that all five preservice teachers were able to explicitly teach NOS in their science lessons, albeit in different ways and to different degrees.

  6. 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

  7. 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. PMID:26286023

  8. 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

  9. 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.

  10. Fostering a Community of Practice through a Professional Development Program to Improve Elementary Teachers' Views of Nature of Science and Teaching Practice

    ERIC Educational Resources Information Center

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

    2009-01-01

    This study explored the development of a community of learners through a professional development program to improve teachers' views of nature of science (NOS) and teaching practice. The "Views of Nature of Science" questionnaire and interviews were used to assess teachers' conceptions of NOS three times over the course of the study. Notes and…

  11. 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.

  12. Scientific Communication and the Nature of Science

    NASA Astrophysics Data System (ADS)

    Nielsen, Kristian H.

    2013-09-01

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

  13. 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,…

  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. 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

  16. 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

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

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

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

  18. 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

  19. 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

  20. 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

  1. 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

  2. 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

  3. 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

  4. 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.

  5. Operational results of shaft repair by installing stave type cooler at Kimitsu Nos. 3 and 4 blast furnaces

    SciTech Connect

    Oda, Hiroshi; Amano, Shigeru; Sakamoto, Aiichiro; Anzai, Osamu; Nakagome, Michiru; Kuze, Toshisuke; Imuta, Akira

    1997-12-31

    Nos. 3 and 4 blast furnaces in Nippon Steel Corporation Kimitsu Works were both initially fitted with cooling plate systems. With the aging of each furnace, the damage to their respective inner-shaft profiles had become serious. Thus, in order to prevent operational change and prolong the furnace life, the inner-shaft profile of each furnace was repaired by replacing the former cooling plate system with the stave type cooler during the two-week-shutdowns. With this repair, stability of burden descent and gas flow near the wall part of the furnace have been achieved. Thus the prolongation of the furnace life is naturally expected.

  6. 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.

  7. 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

    Wheatley, Carmen

    2007-09-01

    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, BH(4) 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 O(2) (-), H(2)O(2), 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

  8. 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

  9. 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

  10. 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

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

    PubMed

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

    2014-01-01

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

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

    PubMed

    Zhu, Yingting; Zhu, Min; Lance, Peter

    2012-10-01

    COX-2 and iNOS are two major inflammatory mediators implicated in colorectal inflammation and cancer. Previously, the role of colorectal fibroblasts involved in regulation of COX-2 and iNOS expression was largely ignored. In addition, the combined interaction of COX-2 and iNOS signalings and their significance in the progression of colorectal inflammation and cancer within the fibroblasts have received little investigation. To address those issues, we investigated the role of colonic fibroblasts in the regulation of COX-2 and iNOS gene expression, and explored possible mechanisms of interaction between COX-2 and iNOS signalings using a colonic CCD-18Co fibroblast line and LPS, a potential stimulator of COX-2 and iNOS. Our results clearly demonstrated that LPS activated COX-2 gene expression and enhanced PGE(2) production, stimulated iNOS gene expression and promoted NO production in the fibroblasts. Interestingly, activation of COX-2 signaling by LPS was not involved in activation of iNOS signaling, while activation of iNOS signaling by LPS contributed in part to activation of COX-2 signaling. Further analysis indicated that PKC plays a major role in the activation and interaction of COX-2 and iNOS signalings induced by LPS in the fibroblasts. PMID:22683859

  13. Generation of a cre recombinase-conditional Nos1ap over-expression transgenic mouse

    PubMed Central

    Auer, Dallas R.; Sysa-Shah, Polina; Bedja, Djahida; Simmers, Jessica L.; Pak, Evgenia; Dutra, Amalia; Cohn, Ronald; Gabrielson, Kathleen L.

    2016-01-01

    Polymorphic non-coding variants at the NOS1AP locus have been associated with the common cardiac, metabolic and neurological traits and diseases. Although, in vitro gene targeting-based cellular and biochemical studies have shed some light on NOS1AP function in cardiac and neuronal tissue, to enhance our understanding of NOS1AP function in mammalian physiology and disease, we report the generation of cre recombinase-conditional Nos1ap over-expression transgenic mice (Nos1apTg). Conditional transgenic mice were generated by the pronuclear injection method and three independent, single-site, multiple copies integration event-based founder lines were selected. For heart-restricted over-expression, Nos1apTg mice were crossed with Mlc2v-cre and Nos1ap transcript over-expression was observed in left ventricles from Nos1apTg; Mlc2v-cre F1 mice. We believe that with the potential of conditional over-expression, Nos1apTg mice will be a useful resource in studying NOS1AP function in various tissues under physiological and disease states. PMID:24563304

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Science Olympiad students' nature of science understandings

    NASA Astrophysics Data System (ADS)

    Philpot, Cindy J.

    2007-12-01

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

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

    PubMed

    Sakthivel, Kunnathur Murugesan; Guruvayoorappan, Chandrasekaran

    2016-01-01

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

  1. Teaching nature of science within a controversial topic: Integrated versus nonintegrated

    NASA Astrophysics Data System (ADS)

    Khishfe, Rola; Lederman, Norman

    2006-04-01

    This study investigated the influence of two different explicit instructional approaches in promoting more informed understandings of nature of science (NOS) among students. Participants, a total of 42 students, comprised two groups in two intact sections of ninth grade. Participants in the two groups were taught environmental science by their regular classroom teacher, with the difference being the context in which NOS was explicitly taught. For the integrated group, NOS instruction was related to the science content about global warming. For the nonintegrated group, NOS was taught through a set of activities that specifically addressed NOS issues and were dispersed across the content about global warming. The treatment for both groups spanned 6 weeks and addressed a unit about global warming and NOS. An open-ended questionnaire, in conjunction with semistructured interviews, was used to assess students' views before and after instruction. Results showed improvements in participants' views of NOS regardless of whether NOS was integrated within the regular content about global warming. Comparison of differences between the two groups showed slightly greater improvement in the informed views of the integrated group participants. On the other hand, there was greater improvement in the transitional views of the nonintegrated group participants. Therefore, the overall results did not provide any conclusive evidence in favor of one approach over the other. Implications on the teaching and learning of NOS are discussed.

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

    ERIC Educational Resources Information Center

    Pekbay, Canay; Yilmaz, Serkan

    2015-01-01

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

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

    ERIC Educational Resources Information Center

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

    2016-01-01

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

  6. 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…

  7. 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…

  8. 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.…

  9. 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…

  10. 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…

  11. 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…

  12. 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…

  13. 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…

  14. 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…

  15. 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…

  16. 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…

  17. 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…

  18. 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.

  19. 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

  20. 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. PMID:23463231

  1. 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. PMID:27486092

  2. Rapid NOS-1-derived nitric oxide and peroxynitrite formation act as signaling agents for inducible NOS-2 expression in vascular smooth muscle cells.

    PubMed

    Scheschowitsch, Karin; de Moraes, João Alfredo; Sordi, Regina; Barja-Fidalgo, Christina; Assreuy, Jamil

    2015-10-01

    Septic vascular dysfunction is characterized by hypotension and hyporeactivity to vasoconstrictors and nitric oxide (NO), reactive oxygen species and peroxynitrite have a prominent role in this condition. However, the mechanism whereby the vascular dysfunction is initiated is poorly understood. Based on previous studies of our group and the literature,we hypothesize that constitutive nitric oxide synthases (c-NOS) and peroxynitrite may play a role in the development of septic vascular dysfunction. Bacterial lipopolysaccharide (LPS) and interferon-γ (IFN) were used to stimulate rat aorta smooth muscle cells (A7r5) and rat aorta slices. This stimulation led to a rapid (within minutes) production of NO and superoxide anion, which led to peroxynitrite formation. When this rapid initial burst was reduced, through the inhibition of c-NOS and NADPH oxidases (NOX) or the scavenging of NO and superoxide the NF-κB activation, NOS-2 expression and nitrite production were significantly attenuated. Although vascular smooth muscle cells express both c-NOS isoforms, gene knockdown revealed that only NOS-1-dependent NO and peroxynitrite formation are important for the later NOS-2 expression. Similar findings were obtained by knockdown NOX-1 gene, one source of superoxide for peroxynitrite formation. Taking together, we show that smooth muscle cell activation by LPS/IFN leads to a rapid formation of NOS-1-derived NO and NOX-1-derived superoxide, forming peroxynitrite; and that this species act as a trigger for NOS-2 expression through NF-κB activation. Therefore, our findings suggest a critical role for NOS-1 and NOX-1 in the initiation of the vascular dysfunction associated with sepsis and septic shock.

  3. Expression of nitric oxide synthase (NOS) genes in channel catfish is highly regulated and time dependent after bacterial challenges.

    PubMed

    Yao, Jun; Li, Chao; Zhang, Jiaren; Liu, Shikai; Feng, Jianbin; Wang, Ruijia; Li, Yun; Jiang, Chen; Song, Lin; Chen, Ailu; Liu, Zhanjiang

    2014-07-01

    Nitric oxide is well known for its roles in immune responses. As such, its synthesizing enzymes have been extensively studied from various species including some teleost fish species. However, the NOS genes have not been characterized in channel catfish (Ictalurus punctatus). In this study, we identified and characterized three NOS genes including one NOS1 and two NOS2 genes in channel catfish. Comparing with the NOS genes from other fish species, the catfish NOS genes are highly conserved in their structural features. Phylogenetic and syntenic analyses allowed determination of NOS1 and NOS2 genes of channel catfish and their orthology relationships. Syntenic analysis, as well as the phylogenetic analysis, indicated that the two NOS2 genes of catfish were lineage-specific duplication. The NOS genes were broadly expressed in most tested tissues, with NOS1 being expressed at the highest levels in the brain, NOS2b1 highly expressed in the skin and gill, and NOS2b2 lowly expressed in most of the tested tissues. The most striking findings of this study was that the expression of the NOS genes are highly regulated after bacterial infection, with time-dependent expression patterns that parallel the migration of macrophages. After Edwardsiella ictaluri challenge, dramatically different responses among the three NOS genes were observed. NOS1 was only significantly in the skin early after infection, while NOS2b1 was rapidly upregulated in gill, but more up-regulated in trunk kidney with the progression of the disease, suggesting such differences in gene expression may be reflective of the migration of macrophages among various tissues of the infected fish. In contrast to NOS1 and NOS2b1, NOS2b2 was normally expressed at very low levels, but it is induced in the brain and liver while significantly down-regulated in most other tissues.

  4. Acute inhibition of myoglobin impairs contractility and energy state of iNOS-overexpressing hearts.

    PubMed

    Wunderlich, Carsten; Flögel, Ulrich; Gödecke, Axel; Heger, Jacqueline; Schrader, Jürgen

    2003-06-27

    Elevated cardiac levels of nitric oxide (NO) generated by inducible nitric oxide synthase (iNOS) have been implicated in the development of heart failure. The surprisingly benign phenotype of recently generated mice with cardiac-specific iNOS overexpression (TGiNOS) provided the rationale to investigate whether NO scavenging by oxymyoglobin (MbO2) yielding nitrate and metmyoglobin (metMb) is involved in preservation of myocardial function in TGiNOS mice. 1H nuclear magnetic resonance (NMR) spectroscopy was used to monitor changes of cardiac myoglobin (Mb) metabolism in isolated hearts of wild-type (WT) and TGiNOS mice. NO formation by iNOS resulted in a significant decrease of the MbO2 signal and a concomitantly emerging metMb signal in spectra of TGiNOS hearts only (DeltaMbO2: -46.3+/-38.4 micromol/kg, DeltametMb: +41.4+/-17.6 micromol/kg, n=6; P<0.05) leaving contractility and energetics unaffected. Inhibition of the Mb-mediated NO degradation by carbon monoxide (20%) led to a deterioration of myocardial contractility in TGiNOS hearts (left ventricular developed pressure: 78.2+/-8.2% versus 96.7+/-4.6% of baseline, n=6; P<0.005), which was associated with a profound pertubation of cardiac energy state as assessed by 31P NMR spectroscopy (eg, phosphocreatine: 13.3+/-1.3 mmol/L (TGiNOS) versus 15.9+/-0.7 mmol/L (WT), n=6; P<0.005). These alterations could be fully antagonized by the NOS inhibitor S-ethylisothiourea. Our findings demonstrate that myoglobin serves as an important cytoplasmic buffer of iNOS-derived NO, which determines the functional consequences of iNOS overexpression. PMID:12775582

  5. Acute inhibition of myoglobin impairs contractility and energy state of iNOS-overexpressing hearts.

    PubMed

    Wunderlich, Carsten; Flögel, Ulrich; Gödecke, Axel; Heger, Jacqueline; Schrader, Jürgen

    2003-06-27

    Elevated cardiac levels of nitric oxide (NO) generated by inducible nitric oxide synthase (iNOS) have been implicated in the development of heart failure. The surprisingly benign phenotype of recently generated mice with cardiac-specific iNOS overexpression (TGiNOS) provided the rationale to investigate whether NO scavenging by oxymyoglobin (MbO2) yielding nitrate and metmyoglobin (metMb) is involved in preservation of myocardial function in TGiNOS mice. 1H nuclear magnetic resonance (NMR) spectroscopy was used to monitor changes of cardiac myoglobin (Mb) metabolism in isolated hearts of wild-type (WT) and TGiNOS mice. NO formation by iNOS resulted in a significant decrease of the MbO2 signal and a concomitantly emerging metMb signal in spectra of TGiNOS hearts only (DeltaMbO2: -46.3+/-38.4 micromol/kg, DeltametMb: +41.4+/-17.6 micromol/kg, n=6; P<0.05) leaving contractility and energetics unaffected. Inhibition of the Mb-mediated NO degradation by carbon monoxide (20%) led to a deterioration of myocardial contractility in TGiNOS hearts (left ventricular developed pressure: 78.2+/-8.2% versus 96.7+/-4.6% of baseline, n=6; P<0.005), which was associated with a profound pertubation of cardiac energy state as assessed by 31P NMR spectroscopy (eg, phosphocreatine: 13.3+/-1.3 mmol/L (TGiNOS) versus 15.9+/-0.7 mmol/L (WT), n=6; P<0.005). These alterations could be fully antagonized by the NOS inhibitor S-ethylisothiourea. Our findings demonstrate that myoglobin serves as an important cytoplasmic buffer of iNOS-derived NO, which determines the functional consequences of iNOS overexpression.

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

    PubMed

    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.

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

    PubMed

    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. PMID:26851909

  8. A Maillard reaction product enhances eNOS activity in human endothelial cells.

    PubMed

    Schmitt, Christoph A; Heiss, Elke H; Schachner, Daniel; Aristei, Yasmin; Severin, Theodor; Dirsch, Verena M

    2010-07-01

    Nitric oxide (NO) produced by the endothelial nitric oxide synthase (eNOS) is an important signaling molecule in the cardiovascular system. Although dietary factors can modulate eNOS activity, putative effects of processed food are barely investigated. We aimed to examine whether the model Maillard reaction product 3-hydroxy-2-methyl-1-propyl-4(1H)-pyridone (HMPP), formed from maltol or starch and propylamine, affects the eNOS system. Incubation of EA.hy926 endothelial cells with 30-300 microM HMPP for 18 h enhanced endothelial NO release measured with the fluorescent probe diaminofluorescein-2 and eNOS activity determined by the [14C]L-arginine-[14C]L-citrulline conversion assay. HMPP increased NO production also in two different types of primary human endothelial cells. Protein levels of eNOS and inducible NO synthase remained unaltered by HMPP. HMPP inhibited eNOS activity within the first 2-4 h, whereas it potently increased eNOS activity after 12-24 h. Levels of eNOS phosphorylation, expression of heat-shock protein 90, caveolin-1 and various antioxidant enzymes were not affected. Intracellular reactive oxygen species remained unchanged by HMPP. This is the first study to demonstrate positive effects of a Maillard reaction product on eNOS activity and endothelial NO production, which is considered favourable for cardiovascular protection. PMID:20112298

  9. PEX7 and EBP50 target iNOS to the peroxisome in hepatocytes.

    PubMed

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

    2013-05-31

    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 8h 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.

  10. 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

  11. [János Bolyai's health according to his military files].

    PubMed

    Acs, Tibor

    2002-01-01

    nos Bolyai (1802-1860) one of the greatest mathematicians of the 19th century, the founder and inventor of non-Euclidean geometry, was born in Transylvania, as son of a Hungarian nobleman and scientist, Farkas Bolyai. Having finished his studies at the Academy for Engineering Corps in Vienna, he joined the army. From 1823 to 1833 he served at different places all over the the Empire. Being however physically and mentally unbalanced, he underwent several medical examinations during his military service. Based on archival documents and files of medical examinations and on those of the following resolutions, the author of the present article gives a comprehensive and very detailed account of the young genius's military career and on the circumstances determining his mental activities while creating the most admirable mathematical theory of the age.

  12. 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.

  13. 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

  14. Functional Domains of NosR, a Novel Transmembrane Iron-Sulfur Flavoprotein Necessary for Nitrous Oxide Respiration

    PubMed Central

    Wunsch, Patrick; Zumft, Walter G.

    2005-01-01

    Bacterial nitrous oxide (N2O) respiration depends on the polytopic membrane protein NosR for the expression of N2O reductase from the nosZ gene. We constructed His-tagged NosR and purified it from detergent-solubilized membranes of Pseudomonas stutzeri ATCC 14405. NosR is an iron-sulfur flavoprotein with redox centers positioned at opposite sides of the cytoplasmic membrane. The flavin cofactor is presumably bound covalently to an invariant threonine residue of the periplasmic domain. NosR also features conserved CX3CP motifs, located C-terminally of the transmembrane helices TM4 and TM6. We genetically manipulated nosR with respect to these different domains and putative functional centers and expressed recombinant derivatives in a nosR null mutant, MK418nosR::Tn5. NosR's function was studied by its effects on N2O respiration, NosZ synthesis, and the properties of purified NosZ proteins. Although all recombinant NosR proteins allowed the synthesis of NosZ, a loss of N2O respiration was observed upon deletion of most of the periplasmic domain or of the C-terminal parts beyond TM2 or upon modification of the cysteine residues in a highly conserved motif, CGWLCP, following TM4. Nonetheless, NosZ purified from the recombinant NosR background exhibited in vitro catalytic activity. Certain NosR derivatives caused an increase in NosZ of the spectral contribution from a modified catalytic Cu site. In addition to its role in nosZ expression, NosR supports in vivo N2O respiration. We also discuss its putative functions in electron donation and redox activation. PMID:15743947

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

    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.

  16. 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

  17. Citrulline immunohistochemistry for demonstration of NOS activity in vivo and in vitro.

    PubMed

    Keilhoff, G; Reiser, M; Stanarius, A; Aoki, E; Wolf, G

    2000-08-01

    Nitric oxide (NO), a biomolecule with major cytotoxic potency, is generated by NO synthases (NOS) utilizing l-arginine as substrate and citrulline is formed as a "side product." In brain tissue, citrulline is considered to be produced exclusively by NOS, due to the incomplete urea cycle in the brain. We aimed to characterize NOS activity by citrulline immunostaining in different cell types of the brain under in situ conditions and in slice and culture experiments. NOS-positive neurons and activated microglial cells were the most prominent citrulline-positive structures. Lack of citrulline immunoreaction in neurons of nNOS knockout mice emphasizes the dependency of citrulline positivity on NOS activity, and likewise there was no citrulline staining after application of the NOS inhibitors 7-nitroindazole and NIL. Interestingly, only a portion of NOS-containing neurons costained for citrulline. The inhibition of argininosuccinate synthetase by alpha-methyl-dl-aspartate increased the number of citrulline-positive cells, apparently due to reduction of the turnover rate of citrulline. Cells positive for NOS but negative for citrulline may indicate that the enzyme is either not activated or inhibited by cellular control mechanisms. The fact that not all citrulline-positive cells were NOS positive may be explained by an insufficient detection sensitivity or by disparate sites of citrulline production and recycling. The present results show that citrulline immunocytochemistry offers a viable and convenient means for studying NOS activity at the single-cell level to elicit its posttranslational control under physiological and pathophysiological conditions. PMID:10944418

  18. Role of SIRT1 and FOXO factors in eNOS transcriptional activation by resveratrol.

    PubMed

    Xia, Ning; Strand, Susanne; Schlufter, Frank; Siuda, Daniel; Reifenberg, Gisela; Kleinert, Hartmut; Förstermann, Ulrich; Li, Huige

    2013-08-01

    Many of the cardiovascular protective effects of resveratrol are attributable to an enhanced production of nitric oxide (NO) by the endothelial NO synthase (eNOS). Resveratrol has been shown to enhance eNOS gene expression as well as eNOS enzymatic activity. The aim of the present study was to analyze the molecular mechanisms of eNOS transcriptional activation by resveratrol. Treatment of human EA.hy 926 endothelial cells with resveratrol led to a concentration-dependent upregulation of eNOS expression. In luciferase reporter gene assay, resveratrol enhanced the activity of human eNOS promoter fragments (3500, 1600, 633 and 263bp in length, respectively), indicating that the proximal promoter region is required for resveratrol-induced eNOS transcriptional activation. Knockdown of the NAD(+)-dependent protein deacetylase sirtuin 1 (SIRT1) by siRNA prevented the upregulation of eNOS mRNA and protein by resveratrol. Forkhead box O (FOXO) transcription factors are established downstream targets of SIRT1. siRNA-mediated knockdown of FOXO1 and FOXO3a abolished the effect of resveratrol on eNOS expression, indicating the involvement of these factors. Resveratrol treatment enhanced the expression of FOXO1 and FOXO3a in EA.hy 926 cells. Reporter gene assay using promoter containing forkhead response elements showed increased FOXO factor activity by resveratrol. In electrophoretic mobility shift assay, the enhanced binding of nuclear proteins to the eNOS promoter regions by resveratrol could be blocked by antibodies against FOXO1 and FOXO3a. In conclusion, resveratrol enhances the expression and activity of FOXO transcription factors. The SIRT1/FOXO factor axis is involved in resveratrol-induced eNOS transcriptional activation.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  20. Oxidative stress increases hepatocyte iNOS gene transcription and promoter activity.

    PubMed

    Kuo, P C; Abe, K Y; Schroeder, R A

    1997-05-19

    Hepatocyte expression of inducible nitric oxide synthase (iNOS) is initiated by the presence of pro-inflammatory cytokines, such as interleukin-1beta (IL-1). In the presence of oxidative stress, IL-1beta mediated hepatocyte iNOS expression and NO synthesis are significantly increased. To determine the underlying molecular mechanism responsible for oxidative stress augmentation of hepatocyte iNOS expression, rat hepatocytes in primary culture were stimulated with IL-1beta (250 U/mL) in the presence and absence of benzenetriol (BZT, 0-100 microM), an autocatalytic source of superoxide at physiologic pH. Nuclear runon analysis demonstrated that BZT was associated with increased iNOS gene transcription in the setting of IL-1 stimulation. Transient transfection of a plasmid construct composed of the rat hepatocyte iNOS promoter and a chloramphenicol transferase reporter gene demonstrated that the combination of BZT and IL-1 significantly increased iNOS promoter activity in comparison to that of IL-1beta alone. These data indicate that BZT-mediated oxidative stress increases IL-1beta induced iNOS gene transcription and iNOS promoter activity.

  1. Prunella vulgaris L. Upregulates eNOS expression in human endothelial cells.

    PubMed

    Xia, Ning; Bollinger, Larissa; Steinkamp-Fenske, Katja; Förstermann, Ulrich; Li, Huige

    2010-01-01

    The purported effects of "circulation-improving" herbs used in traditional Chinese medicine (TCM) show striking similarities with the vascular actions of nitric oxide (NO) produced by the endothelial NO synthase (eNOS). We have previously reported that Salviae miltiorrhizae radix and Zizyphi spinosae semen upregulate eNOS expression. In the present study, we studied the effect on eNOS gene expression of 15 Chinese herbs with potential effects on the vasculature, and identified Prunella vulgaris L. (PVL) (flowering spike) as a potent eNOS-upregulating agent. In EA.hy 926 cells, a cell line derived from human umbilical vein endothelial cells (HUVEC), an aqueous extract of PVL increased eNOS promoter activity, eNOS mRNA and protein expressions, as well as NO production in concentration- and time-dependent manners. We have previously shown that ursolic acid (a constituent of Salviae miltiorrhizae radix), betulinic acid (a compound present in Zizyphi spinosae semen), luteolin and cynaroside (ingredients of artichoke, Cynara scolymus L.) are capable of enhancing eNOS gene expression. These compounds are also present in significant quantities in PVL. Thus, PVL contains active principles that stimulate human eNOS gene expression, and such compounds may have therapeutic potential against cardiovascular diseases. PMID:20503475

  2. S-glutathionylation uncouples eNOS and regulates its cellular and vascular function

    PubMed Central

    Chen, Chun-An; Wang, Tse-Yao; Varadharaj, Saradhadevi; Reyes, Levy A.; Hemann, Craig; Hassan Talukder, M. A.; Chen, Yeong-Renn; Druhan, Lawrence J.; Zweier, Jay L.

    2012-01-01

    Endothelial nitric oxide synthase (eNOS) is critical in the regulation of vascular function, and can generate both nitric oxide (NO) and superoxide (O2•−), which are key mediators of cellular signalling. In the presence of Ca2+/calmodulin, eNOS produces NO, endothelial-derived relaxing factor, from L-arginine (L-Arg) by means of electron transfer from NADPH through a flavin containing reductase domain to oxygen bound at the haem of an oxygenase domain, which also contains binding sites for tetrahydrobiopterin (BH4) and L-Arg1–3. In the absence of BH4, NO synthesis is abrogated and instead O2•− is generated4–7. While NOS dysfunction occurs in diseases with redox stress, BH4 repletion only partly restores NOS activity and NOS-dependent vasodilation7. This suggests that there is an as yet unidentified redox-regulated mechanism controlling NOS function. Protein thiols can undergo S-glutathionylation, a reversible protein modification involved in cellular signalling and adaptation8,9. Under oxidative stress, S-glutathionylation occurs through thiol–disulphide exchange with oxidized glutathione or reaction of oxidant-induced protein thiyl radicals with reduced glutathione10,11. Cysteine residues are critical for the maintenance of eNOS function12,13; we therefore speculated that oxidative stress could alter eNOS activity through S-glutathionylation. Here we show that S-glutathionylation of eNOS reversibly decreases NOS activity with an increase in O2•− generation primarily from the reductase, in which two highly conserved cysteine residues are identified as sites of S-glutathionylation and found to be critical for redox-regulation of eNOS function. We show that eNOS S-glutathionylation in endothelial cells, with loss of NO and gain of O2•− generation, is associated with impaired endothelium-dependent vasodilation. In hypertensive vessels, eNOS S-glutathionylation is increased with impaired endothelium-dependent vasodilation that is restored by thiol

  3. [Research Progress of NOS3 Participation in Regulatory Mechanisms of Cardiovascular Diseases].

    PubMed

    Sun, Ting; Chi, Qingjia; Wang, Guixue

    2016-02-01

    Cardiovascular disease has been a major threat to human's health and lives for many years. It is of great importance to explore the mechanisms and develop strategies to prevent the pathogenesis. Generally, cardiovascular disease is associated with endothelial dysfunction, which is closely related to the nitric oxide (NO)-mediated vasodilatation. The release of NO is regulated by NOS3 gene in mammals' vascular system. A great deal of evidences have shown that the polymorphism and epigenetic of NOS3 gene play vital roles in the pathological process of cardiovascular disease. To gain insights into the role of NOS3 in the cardiovascular diseases, we reviewed the molecular mechanisms underlying the development of cardiovascular diseases in this paper, including the uncoupling of NOS3 protein, epigenetic and polymorphism of NOS3 gene. The review can also offer possible strategies to prevent and treat cardiovascular diseases. PMID:27382763

  4. Redox-stable cyclic peptide inhibitors of the SPSB2-iNOS interaction.

    PubMed

    Yap, Beow Keat; Harjani, Jitendra R; Leung, Eleanor W W; Nicholson, Sandra E; Scanlon, Martin J; Chalmers, David K; Thompson, Philip E; Baell, Jonathan B; Norton, Raymond S

    2016-03-01

    SPSB2 mediates the proteasomal degradation of iNOS. Inhibitors of SPSB2-iNOS interaction are expected to prolong iNOS lifetime and thereby enhance killing of persistent pathogens. Here, we describe the synthesis and characterization of two redox-stable cyclized peptides containing the DINNN motif required for SPSB2 binding. Both analogues bind with low nanomolar affinity to the iNOS binding site on SPSB, as determined by SPR and (19)F NMR, and efficiently displace full-length iNOS from binding to SPSB2 in macrophage cell lysates. These peptides provide a foundation for future development of redox-stable, potent ligands for SPSB proteins as a potential novel class of anti-infectives. PMID:26921848

  5. Redox-stable cyclic peptide inhibitors of the SPSB2-iNOS interaction.

    PubMed

    Yap, Beow Keat; Harjani, Jitendra R; Leung, Eleanor W W; Nicholson, Sandra E; Scanlon, Martin J; Chalmers, David K; Thompson, Philip E; Baell, Jonathan B; Norton, Raymond S

    2016-03-01

    SPSB2 mediates the proteasomal degradation of iNOS. Inhibitors of SPSB2-iNOS interaction are expected to prolong iNOS lifetime and thereby enhance killing of persistent pathogens. Here, we describe the synthesis and characterization of two redox-stable cyclized peptides containing the DINNN motif required for SPSB2 binding. Both analogues bind with low nanomolar affinity to the iNOS binding site on SPSB, as determined by SPR and (19)F NMR, and efficiently displace full-length iNOS from binding to SPSB2 in macrophage cell lysates. These peptides provide a foundation for future development of redox-stable, potent ligands for SPSB proteins as a potential novel class of anti-infectives.

  6. Screening of NOS activity and selectivity of newly synthesized acetamidines using RP-HPLC.

    PubMed

    Fantacuzzi, Marialuigia; Maccallini, Cristina; Di Matteo, Mauro; Ammazzalorso, Alessandra; Bruno, Isabella; De Filippis, Barbara; Giampietro, Letizia; Mollica, Adriano; Amoroso, Rosa

    2016-02-20

    Nitric Oxide Synthase (NOS) inhibitors could play a powerful role in inflammatory and neurodegenerative diseases. In this work, novel acetamidine derivatives of NOS were synthesized and the inhibitor activity was evalued. To screen the activity and selectivity, the l-citrulline residue, after the enzymatic NOS assay, was derivatized with o-phthaldialdehyde/N-acetyl cysteine (OPA/NAC) and then evaluated by RP-HPLC method with fluorescence detection. All compounds did not affect the activity of endothelial and neuronal isoforms, while nine of them possessed a percentage of iNOS activity at 10μM lower than 50%, and were selected for IC50 evaluation. Among them, a compound emerged as a very potent (IC50 of 53nM) and selective iNOS inhibitor. PMID:26689740

  7. 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.

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

    NASA Astrophysics Data System (ADS)

    Rivas, Michael Gerald

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

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

    NASA Astrophysics Data System (ADS)

    Khishfe, Rola

    2015-07-01

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

  10. Malaria severity and human nitric oxide synthase type 2 (NOS2) promoter haplotypes

    PubMed Central

    Levesque, Marc C.; Hobbs, Maurine R.; O’Loughlin, Charles W.; Chancellor, Jennifer A.; Chen, Youwei; Tkachuk, Ariana N.; Booth, Jennifer; Patch, Kistie B.; Allgood, Sallie; Pole, Ann R.; Fernandez, Carolyn A.; Mwaikambo, Esther D.; Mutabingwa, Theonest K.; Fried, Michal; Sorensen, Bess; Duffy, Patrick E.; Granger, Donald L.; Anstey, Nicholas M.; Weinberg, J. Brice

    2010-01-01

    Nitric oxide (NO) mediates host resistance to severe malaria and other infectious diseases. NO production and mononuclear cell expression of the NO producing enzyme-inducible nitric oxide synthase (NOS2) have been associated with protection from severe falciparum malaria. The purpose of this study was to identify single nucleotide polymorphisms (SNPs) and haplotypes in the NOS2 promoter, to identify associations of these haplotypes with malaria severity and to test the effects of these polymorphisms on promoter activity. We identified 34 SNPs in the proximal 7.3 kb region of the NOS2 promoter and inferred NOS2 promoter haplotypes based on genotyping 24 of these SNPs in a population of Tanzanian children with and without cerebral malaria. We identified 71 haplotypes; 24 of these haplotypes comprised 82% of the alleles. We determined whether NOS2 promoter haplotypes were associated with malaria severity in two groups of subjects from Dar es Salaam (N = 185 and N = 250) and in an inception cohort of children from Muheza-Tanga, Tanzania (N = 883). We did not find consistent associations of NOS2 promoter haplotypes with malaria severity or malarial anemia, although interpretation of these results was potentially limited by the sample size of each group. Furthermore, cytokine-induced NOS2 promoter activity determined using luciferase reporter constructs containing the proximal 7.3 kb region of the NOS2 promoter and the G-954C or C-1173T SNPs did not differ from NOS2 promoter constructs that lacked these polymorphisms. Taken together, these studies suggest that the relationship between NOS2 promoter polymorphisms and malaria severity is more complex than previously described. PMID:19859740

  11. NASA Operational Simulator for Small Satellites (NOS3)

    NASA Technical Reports Server (NTRS)

    Zemerick, Scott

    2015-01-01

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

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

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

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

  13. 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…

  14. 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…

  15. 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…

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

    NASA Astrophysics Data System (ADS)

    Kits, Kara M.

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

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed Central

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

    2016-01-01

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

  19. 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.

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

    ERIC Educational Resources Information Center

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

    2011-01-01

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

  1. Improving Preservice Elementary Teachers' Views of the Nature of Science Using Explicit-Reflective Teaching in a Science, Technology and Society Course

    ERIC Educational Resources Information Center

    Küçük, Mehmet

    2008-01-01

    This study examined twelve preservice elementary teachers' views on the nature of science (NOS). The student teachers participated in a cohort group as they took a science, technology and society course during which the target NOS aspects were taught through an explicit/reflective approach. The main goals were to that (1) improve preservice…

  2. The Influence of an Activity-Based Explicit Approach on the Turkish Prospective Science Teachers' Conceptions of the Nature of Science

    ERIC Educational Resources Information Center

    Celik, Suat; Bayrakceken, Samih

    2012-01-01

    The aim of this study was to investigate the effect of an activity-based explicit nature of science (NOS) instruction undertaken in the context of a "Science, Technology and Society" course on the prospective science teachers' (PSTs') understandings of NOS. In this course, social science based inquiry activities were used to as a context to lead…

  3. 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…

  4. 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…

  5. Trainee Teachers' Perceptions of the Nature of Science and Implications For ... Pre-Service Teacher Training in the UK Context: A Reflective Narrative

    ERIC Educational Resources Information Center

    Golabek, Charles; Amrane-Cooper, Linda

    2013-01-01

    This article highlights the importance of developing trainee teachers' knowledge and understanding with respect to the Nature of Science (NoS), as this has long been considered an area of concern. The breadth of understanding of NoS can influence a teacher's ability to engage with enquiry and can determine their ability to teach effectively.…

  6. 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.

  7. C. pneumoniae disrupts eNOS trafficking and impairs NO production in human aortic endothelial cells.

    PubMed

    Mueller, Konrad E; Wolf, Katerina

    2015-01-01

    Endothelial nitric oxide synthase (eNOS) generated NO plays a crucial physiological role in the regulation of vascular tone. eNOS is a constitutively expressed synthase whose enzymatic function is regulated by dual acylation, phosphorylation, protein-protein interaction and subcellular localization. In endothelial cells, the enzyme is primarily localized to the Golgi apparatus (GA) and the plasma membrane where it binds to caveolin-1. Upon stimulation, the enzyme is translocated from the plasma membrane to the cytoplasm where it generates NO. When activation of eNOS ceases, the majority of the enzyme is recycled back to the membrane fraction. An inability of eNOS to cycle between the cytosol and the membrane leads to impaired NO production and vascular dysfunction. Chlamydia pneumoniae is a Gram-negative obligate intracellular bacterium that primarily infects epithelial cells of the human respiratory tract, but unlike any other chlamydial species, C. pneumoniae displays tropism toward atherosclerotic tissues. In this study, we demonstrate that C. pneumoniae inclusions colocalize with eNOS, and the microorganism interferes with trafficking of the enzyme from the GA to the plasma membrane in primary human aortic endothelial cells. This mislocation of eNOS results in significant inhibition of NO release by C. pneumoniae-infected cells. Furthermore, we show that the distribution of eNOS in C. pneumoniae-infected cells is altered due to an intimate association of the Golgi complex with chlamydial inclusions rather than by direct interaction of the enzyme with the chlamydial inclusion membrane.

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

    PubMed Central

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

    2016-01-01

    Aneurysmal subarachnoid hemorrhage (SAH) typically carries a poor prognosis. Growing evidence indicates that overabundant production of nitric oxide (NO) may be responsible for a large part of the secondary injury that follows SAH. Although SAH modulates the activity of all three isoforms of nitric oxide synthase (NOS), the inducible isoform, NOS-2, accounts for a majority of NO-mediated secondary injuries after SAH. Here, we review the indispensable physiological roles of NO that must be preserved, even while attempting to downmodulate the pathophysiologic effects of NO that are induced by SAH. We examine the effects of SAH on the function of the various NOS isoforms, with a particular focus on the pathological effects of NOS-2 and on the mechanisms responsible for its transcriptional upregulation. Finally, we review interventions to block NOS-2 upregulation or to counteract its effects, with an emphasis on the potential therapeutic strategies to improve outcomes in patients afflicted with SAH. There is still much to be learned regarding the apparently maladaptive response of NOS-2 and its harmful product NO in SAH. However, the available evidence points to crucial effects that, on balance, are adverse, making the NOS-2/NO/peroxynitrite axis an attractive therapeutic target in SAH. PMID:27774520

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

    SciTech Connect

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

    1999-04-01

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

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

    PubMed

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

    2016-02-10

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

  11. Insulin inhibits hepatocyte iNOS expression induced by cytokines by an Akt-dependent mechanism.

    PubMed

    Harbrecht, Brian G; Nweze, Ikenna; Smith, Jason W; Zhang, Baochun

    2012-01-01

    Hepatocyte inducible nitric oxide synthese (iNOS) expression is a tightly controlled pathway that mediates hepatic inflammation and hepatocyte injury in a variety of disease states. We have shown that cyclic adenosine monophosphate (cAMP) regulates cytokine-induced hepatocyte iNOS expression through mechanisms that involve protein kinase B/Akt. We hypothesized that insulin, which activates Akt signaling in hepatocytes, as well as signaling through p38 and MAPK p42/p44, would regulate iNOS expression during inflammation. In primary rat hepatocytes, insulin inhibited cytokine-stimulated nitrite accumulation and iNOS expression in a dose-dependent manner. Inhibition of MAPK p42/p44 with PD98059 had no effect on iNOS activation, whereas SB203580 to block p38 reversed insulin's inhibitory effect. However, insulin did not increase p38 activation and inhibition of p38 signaling with a dominant negative p38 plasmid had no effect on cytokine- or insulin-mediated effects on iNOS. We found that SB203580 blocked insulin-induced Akt activation. Inhibition of Akt signaling with LY294002 or a dominant negative Akt plasmid increased cytokine-stimulated nitrite production and iNOS protein expression and blocked the inhibitory effects of insulin. NF-κB induces iNOS expression and can be regulated by Akt, but insulin had no effect on cytokine-mediated IκBα levels or NF-κB p65 translocation. Our data demonstrate that insulin inhibits cytokine-stimulated hepatocyte iNOS expression and does so through effects on Akt-mediated signaling. PMID:22038823

  12. Control of Food Intake and Energy Expenditure by Nos1 Neurons of the Paraventricular Hypothalamus

    PubMed Central

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

    2014-01-01

    The paraventricular nucleus of the hypothalamus (PVH) contains a heterogeneous cluster of Sim1-expressing cell types that comprise a major autonomic output nucleus and play critical roles in the control of food intake and energy homeostasis. The roles of specific PVH neuronal subtypes in energy balance have yet to be defined, however. The PVH contains nitric oxide synthase-1 (Nos1)-expressing (Nos1PVH) neurons of unknown function; these represent a subset of the larger population of Sim1-expressing PVH (Sim1PVH) neurons. To determine the role of Nos1PVH neurons in energy balance, we used Cre-dependent viral vectors to both map their efferent projections and test their functional output in mice. Here we show that Nos1PVH neurons project to hindbrain and spinal cord regions important for food intake and energy expenditure control. Moreover, pharmacogenetic activation of Nos1PVH neurons suppresses feeding to a similar extent as Sim1PVH neurons, and increases energy expenditure and activity. Furthermore, we found that oxytocin-expressing PVH neurons (OXTPVH) are a subset of Nos1PVH neurons. OXTPVH cells project to preganglionic, sympathetic neurons in the thoracic spinal cord and increase energy expenditure upon activation, though not to the same extent as Nos1PVH neurons; their activation fails to alter feeding, however. Thus, Nos1PVH neurons promote negative energy balance through changes in feeding and energy expenditure, whereas OXTPVH neurons regulate energy expenditure alone, suggesting a crucial role for non-OXT Nos1PVH neurons in feeding regulation. PMID:25392498

  13. Smooth muscle NOS, colocalized with caveolin-1, modulates contraction in mouse small intestine

    PubMed Central

    El-Yazbi, Ahmed F; Cho, Woo Jung; Cena, Jonathan; Schulz, Richard; Daniel, Edwin E

    2008-01-01

    Neuronal nitric oxide synthase (nNOS) in myenteric neurons is activated during peristalsis to produce nitric oxide which relaxes intestinal smooth muscle. A putative nNOS is also found in the membrane of intestinal smooth muscle cells in mouse and dog. In this study we studied the possible functions of this nNOS expressed in mouse small intestinal smooth muscle colocalized with caveolin-1(Cav-1). Cav-1 knockout mice lacked nNOS in smooth muscle and provided control tissues. 60 mM KCl was used to increase intracellular [Ca2+] through L-type Ca2+ channel opening and stimulate smooth muscle NOS activity in intestinal tissue segments. An additional contractile response to LNNA (100 μM, NOS inhibitor) was observed in KCl-contracted tissues from control mice and was almost absent in tissues from Cav-1 knockout mice. Disruption of caveolae with 40 mM methyl-β cyclodextrin in tissues from control mice led to the loss of Cav-1 and nNOS immunoreactivity from smooth muscle as shown by immunohistochemistry and a reduction in the response of these tissues to N-ω-nitro-L-arginine (LNNA). Reconstitution of membrane cholesterol using water soluble cholesterol in the depleted segments restored the immunoreactivity and the response to LNNA added after KCl. Nicardipine (1 μM) blocked the responses to KCl and LNNA confirming the role of L-type Ca2+ channels. ODQ (1 μM, soluble guanylate cyclase inhibitor) had the same effect as inhibition of NOS following KCl. We conclude that the activation of nNOS, localized in smooth muscle caveolae, by calcium entering through L-type calcium channels triggers nitric oxide production which modulates muscle contraction by a cGMP-dependent mechanism. PMID:18400048

  14. 75 FR 80546 - Virginia Electric and Power Company; Surry Power Station Unit Nos. 1 and 2; Exemption

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-22

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

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

    PubMed

    Poljakovic, Mirjana; Persson, Katarina

    2003-01-01

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

  16. 75 FR 75706 - Dresden Nuclear Power Station, Units 2 and 3 and Quad Cities Nuclear Power Station, Unit Nos. 1...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-06

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

  17. 75 FR 66802 - Calvert Cliffs Nuclear Power Plant, LLC; Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and 2...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-29

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

  18. Red wine extract decreases pro-inflammatory markers, nuclear factor-κB and inducible NOS, in experimental metabolic syndrome.

    PubMed

    Janega, Pavol; Klimentová, Jana; Barta, Andrej; Kovácsová, Mária; Vranková, Stanislava; Cebová, Martina; Čierna, Zuzana; Matúsková, Zuzana; Jakovljevic, Vladimir; Pechánová, Olga

    2014-09-01

    We aimed to analyse the effects of alcohol-free Alibernet red wine extract (AWE) on nitric oxide synthase (NOS) activity and pro-inflammatory markers such as nuclear factor-κB (NFκB) and inducible NOS (iNOS) protein expression in experimental metabolic syndrome. Young 6 week-old male Wistar Kyoto (WKY) and obese, spontaneously hypertensive rats (SHR/N-cp) were divided into control groups and groups treated with AWE (24.2 mg per kg per day) for 3 weeks (n = 6 in each group). Total NOS activity and endothelial NOS (eNOS), iNOS and NFκB (p65) protein expressions were determined in the heart left ventricle and aorta by Western blot and immunohistochemical analysis. All parameters investigated significantly increased in the aorta of SHR/N-cp rats. Pro-inflammatory markers such as NFκB and iNOS were increased in the left ventricle as well. AWE treatment did not affect total NOS activity and eNOS expression in the aorta; however, it was able to decrease NFκB and iNOS protein expression in both the left ventricle and aorta. In conclusion, in the cardiovascular system, Alibernet red wine extract decreased NFκB and iNOS protein expressions elevated as a consequence of developed metabolic syndrome. This effect may represent one of the protective, anti-inflammatory properties of Alibernet red wine polyphenols on cardiovascular risk factors related to metabolic syndrome.

  19. Placental expression of eNOS, iNOS and the major protein components of caveolae in women with pre-eclampsia.

    PubMed

    Smith-Jackson, K; Hentschke, M R; Poli-de-Figueiredo, C E; Pinheiro da Costa, B E; Kurlak, L O; Broughton Pipkin, F; Czajka, A; Mistry, H D

    2015-05-01

    Caveolae regulate many cardiovascular functions and thus could be of interest in relation to pre-eclampsia, a pregnancy specific disorder characterised by hypertension and proteinuria. We examined placental mRNA and protein expression/localisation of the caveolae components Caveolin 1-3, Cavin 1-4 as well as eNOS/iNOS in normotensive control (n = 24) and pre-eclamptic pregnancies (n = 19). Placental mRNA expression of caveolin-1, cavin 1-3, was lower and eNOS expression was increased in pre-eclampsia (P < 0.05 for all). Additionally Caveolin-1 protein expression was also reduced in pre-eclampsia (P = 0.007); this could be an adaptive response in pre-eclampsia, possibly to attenuate the oxidative stress/inflammation. PMID:25707739

  20. Temporal naturalism

    NASA Astrophysics Data System (ADS)

    Smolin, Lee

    2015-11-01

    Two people may claim both to be naturalists, but have divergent conceptions of basic elements of the natural world which lead them to mean different things when they talk about laws of nature, or states, or the role of mathematics in physics. These disagreements do not much affect the ordinary practice of science which is about small subsystems of the universe, described or explained against a background, idealized to be fixed. But these issues become crucial when we consider including the whole universe within our system, for then there is no fixed background to reference observables to. I argue here that the key issue responsible for divergent versions of naturalism and divergent approaches to cosmology is the conception of time. One version, which I call temporal naturalism, holds that time, in the sense of the succession of present moments, is real, and that laws of nature evolve in that time. This is contrasted with timeless naturalism, which holds that laws are immutable and the present moment and its passage are illusions. I argue that temporal naturalism is empirically more adequate than the alternatives, because it offers testable explanations for puzzles its rivals cannot address, and is likely a better basis for solving major puzzles that presently face cosmology and physics. This essay also addresses the problem of qualia and experience within naturalism and argues that only temporal naturalism can make a place for qualia as intrinsic qualities of matter.

  1. 5. Walled courtyard with basketball hoop between Buildings Nos. 9944B ...

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

    5. Walled courtyard with basketball hoop between Buildings Nos. 9944-B (left) and 9945-B (right). - Madigan Hospital, Detention Wards, Bounded by Wilson & McKinley Avenues & Garfield & Lincoln Streets, Tacoma, Pierce County, WA

  2. The evolutionary functions of cardiac NOS/NO in vertebrates tracked by fish and amphibian paradigms.

    PubMed

    Imbrogno, Sandra; Tota, Bruno; Gattuso, Alfonsina

    2011-06-30

    During early ectotherm vertebrate evolution the heart was redesigned as a high pressure pump adapted to perfuse larger body sizes. To compensate the consequent higher organ complexity and heterogeneity (ventricular myoarchitecture and blood supply), conceivably the three principal cardiac cell components, the endocardium, the contractile myocardium and the epicardium recruited and diversified the cardiac NOS system for functioning not only as a major modulator, but also as a spatio-temporal integrator of heart function. In the context of NOS isoform evolution, we will use fish and amphibian paradigms to illustrate major aspects of cardiac spatial and temporal integration achieved by the NOS/NO systems. This may reveal a primordial cardiac NOS/NO function, allocating it in a wider biological framework than so far envisioned.

  3. Myoglobin protects the heart from inducible nitric-oxide synthase (iNOS)-mediated nitrosative stress.

    PubMed

    Gödecke, Axel; Molojavyi, Andre; Heger, Jacqueline; Flögel, Ulrich; Ding, Zhaoping; Jacoby, Christoph; Schrader, Jürgen

    2003-06-13

    The role of inducible nitric-oxide synthase (iNOS) in the pathogenesis of heart failure is still a matter of controversy. In contrast to early reports favoring a contribution of iNOS because of the negative inotropic and apoptotic potential of NO, more recent clinical and experimental data question a causative role. Here we report that transgenic mice with cardiac specific iNOS-overexpression and concomitant myoglobin-deficiency (tg-iNOS+/myo-/-) develop signs of heart failure with cardiac hypertrophy, ventricular dilatation, and interstitial fibrosis. In addition, reactivation of the fetal gene expression program typical for heart failure occurs. The structural and molecular changes are accompanied by functional depression such as reduced contractility, ejection fraction, and cardiac energetics. Our findings indicate that excessive cardiac NO formation can cause heart failure; however, under normal circumstances myoglobin constitutes the important barrier that efficiently protects the heart from nitrosative stress. PMID:12665503

  4. Myoglobin protects the heart from inducible nitric-oxide synthase (iNOS)-mediated nitrosative stress.

    PubMed

    Gödecke, Axel; Molojavyi, Andre; Heger, Jacqueline; Flögel, Ulrich; Ding, Zhaoping; Jacoby, Christoph; Schrader, Jürgen

    2003-06-13

    The role of inducible nitric-oxide synthase (iNOS) in the pathogenesis of heart failure is still a matter of controversy. In contrast to early reports favoring a contribution of iNOS because of the negative inotropic and apoptotic potential of NO, more recent clinical and experimental data question a causative role. Here we report that transgenic mice with cardiac specific iNOS-overexpression and concomitant myoglobin-deficiency (tg-iNOS+/myo-/-) develop signs of heart failure with cardiac hypertrophy, ventricular dilatation, and interstitial fibrosis. In addition, reactivation of the fetal gene expression program typical for heart failure occurs. The structural and molecular changes are accompanied by functional depression such as reduced contractility, ejection fraction, and cardiac energetics. Our findings indicate that excessive cardiac NO formation can cause heart failure; however, under normal circumstances myoglobin constitutes the important barrier that efficiently protects the heart from nitrosative stress.

  5. 78 FR 39018 - Entergy Nuclear Operations, Inc.; Indian Point Nuclear Generating Unit Nos. 2 and 3

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-28

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

  6. Discovery of inducible nitric oxide synthase (iNOS) inhibitor development candidate KD7332, part 1: Identification of a novel, potent, and selective series of quinolinone iNOS dimerization inhibitors that are orally active in rodent pain models.

    PubMed

    Bonnefous, Céline; Payne, Joseph E; Roppe, Jeffrey; Zhuang, Hui; Chen, Xiaohong; Symons, Kent T; Nguyen, Phan M; Sablad, Marciano; Rozenkrants, Natasha; Zhang, Yan; Wang, Li; Severance, Daniel; Walsh, John P; Yazdani, Nahid; Shiau, Andrew K; Noble, Stewart A; Rix, Peter; Rao, Tadimeti S; Hassig, Christian A; Smith, Nicholas D

    2009-05-14

    There are three isoforms of dimeric nitric oxide synthases (NOS) that convert arginine to citrulline and nitric oxide. Inducible NOS is implicated in numerous inflammatory diseases and, more recently, in neuropathic pain states. The majority of existing NOS inhibitors are either based on the structure of arginine or are substrate competitive. We describe the identification from an ultra high-throughput screen of a novel series of quinolinone small molecule, nonarginine iNOS dimerization inhibitors. SAR studies on the screening hit, coupled with an in vivo lipopolysaccharide (LPS) challenge assay measuring plasma nitrates and drug levels, rapidly led to the identification of compounds 12 and 42--potent inhibitors of the human and mouse iNOS enzyme that were highly selective over endothelial NOS (eNOS). Following oral dosing, compounds 12 and 42 gave a statistical reduction in pain behaviors in the mouse formalin model, while 12 also statistically reduced neuropathic pain behaviors in the chronic constriction injury (Bennett) model.

  7. Agricultural Education Science Activity--Nos. GGEB 1-2.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. Agricultural Curriculum Materials Service.

    This packet contains two science learning activities that can be used in agricultural education courses. The first activity, "Using Ethanol as a Solvent," is intended to help students describe the characteristics of a solvent, to enhance student observational skills dealing with physical changes, and to demonstrate the acid or alkaline nature of…

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

    PubMed Central

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

    2010-01-01

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

  9. Development of nNOS-positive neurons in the rat sensory ganglia after capsaicin treatment.

    PubMed

    Masliukov, Petr M; Moiseev, Konstantin Y; Korzina, Marina B; Porseva, Valentina V

    2015-08-27

    To gain a better understanding of the neuroplasticity of afferent neurons during postnatal ontogenesis, the distribution of neuronal nitric oxide synthase (nNOS) immunoreactivity was studied in the nodose ganglion (NG) and Th2 and L4 dorsal root ganglia (DRG) from vehicle-treated and capsaicin-treated female Wistar rats at different ages (10-day-old, 20-day-old, 30-day-old, and two-month-old). The percentage of nNOS-immunoreactive (IR) neurons decreased after capsaicin treatment in all studied ganglia in first 20 days of life, from 55.4% to 36.9% in the Th2 DRG, from 54.6% to 26.1% in the L4 DRG and from 37.1% to 15.0% in the NG. However, in the NG, the proportion of nNOS-IR neurons increased after day 20, from 11.8% to 23.9%. In the sensory ganglia of all studied rats, a high proportion of nNOS-IR neurons bound isolectin B4. Approximately 90% of the sensory nNOS-IR neurons bound to IB4 in the DRG and approximately 80% in the NG in capsaicin-treated and vehicle-treated rats. In 10-day-old rats, a large number of nNOS-IR neurons also expressed TrkA, and the proportion of nNOS(+)/TrkA(+) neurons was larger in the capsaicin-treated rats compared with the vehicle-treated animals. During development, the percentage of nNOS(+)/TrkA(+) cells decreased in the first month of life in both groups. The information provided here will also serve as a basis for future studies investigating mechanisms of sensory neuron development.

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

    PubMed

    Lu, Wei; Wu, Shiyong

    2013-08-01

    Ultraviolet B (UVB) induces an immediate activation of cNOSs, which contributes to the early release of nitric oxide after irradiation. UVB also induces the expression of iNOS, which peaks at both the mRNA and protein level near 24 h post-irradiation. The induced expression of iNOS contributes largely to the late elevation of nitric oxide after UVB irradiation. However, the regulation of iNOS expression in the early stages of UVB irradiation is not well studied. We previously reported that the UVB-induced early release of nitric oxide leads to the activation of PERK and GCN2, which phosphorylate the alpha-subunit of eIF2 and inhibit protein synthesis. In this report, we demonstrate that eIF2 phosphorylation plays a critical role in regulation of iNOS expression in the early-phase (with in 12 h) of UVB irradiation. Our data shows that with an increased phosphorylation of eIF2, the iNOS protein expression was reduced even though the iNOS mRNA expression was linearly increased in HaCaT and MEF cells after UVB irradiation. The UVB-induced dynamic up- and down-regulation of iNOS expression was almost completely lost in MEF(A/A) cells, which contain a nonphosphorylatable S51A mutation on eIF2. Our results suggest that the UVB-induced eIF2 phosphorylation does not only regulate iNOS expression at the translational level, but at the transcriptional level as well. PMID:22430947

  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. 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.

  13. 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…

  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. 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…

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

    ERIC Educational Resources Information Center

    Saif, Abdulsalam Dale Amer

    2016-01-01

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

  17. 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…

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

    ERIC Educational Resources Information Center

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

    2013-01-01

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

  19. 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,…

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

    ERIC Educational Resources Information Center

    Oehrtman, Michael; Lawson, Anton E.

    2008-01-01

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

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

    PubMed

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

    2016-01-01

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

  2. Nitric oxide synthase 2 (NOS2) expression in histologically normal margins of oral squamous cell carcinoma

    PubMed Central

    Itoiz, María E.; Guiñazú, Natalia; Piccini, Daniel; Gea, Susana; López-de Blanc, Silvia

    2014-01-01

    The activity of Nitric Oxide Synthase 2 (NOS2) was found in oral squamous cell carcinomas (OSCC) but not in normal mucosa. Molecular changes associated to early carcinogenesis have been found in mucosa near carcinomas, which is considered a model to study field cancerization. The aim of the present study is to analyze NOS2 expression at the histologically normal margins of OSCC. Study Design: Eleven biopsy specimens of OSCC containing histologically normal margins (HNM) were analyzed. Ten biopsies of normal oral mucosa were used as controls. The activity of NOS2 was determined by immunohistochemistry. Salivary nitrate and nitrite as well as tobacco and alcohol consumption were also analyzed. The Chi-squared test was applied. Results: Six out of the eleven HNM from carcinoma samples showed positive NOS2 activity whereas all the control group samples yielded negative (p=0.005). No statistically significant association between enzyme expression and tobacco and/or alcohol consumption and salivary nitrate and nitrite was found. Conclusions: NOS2 expression would be an additional evidence of alterations that may occur in a state of field cancerization before the appearance of potentially malignant morphological changes. Key words:Field cancerization, oral squamous cell carcinoma, Nitric Oxide Synthase 2 (NOS2), malignity markers. PMID:24316703

  3. Converging evidence for an impact of a functional NOS gene variation on anxiety-related processes.

    PubMed

    Kuhn, Manuel; Haaker, Jan; Glotzbach-Schoon, Evelyn; Schümann, Dirk; Andreatta, Marta; Mechias, Marie-Luise; Raczka, Karolina; Gartmann, Nina; Büchel, Christian; Mühlberger, Andreas; Pauli, Paul; Reif, Andreas; Kalisch, Raffael; Lonsdorf, Tina B

    2016-05-01

    Being a complex phenotype with substantial heritability, anxiety and related phenotypes are characterized by a complex polygenic basis. Thereby, one candidate pathway is neuronal nitric oxide (NO) signaling, and accordingly, rodent studies have identified NO synthase (NOS-I), encoded by NOS1, as a strong molecular candidate for modulating anxiety and hippocampus-dependent learning processes. Using a multi-dimensional and -methodological replication approach, we investigated the impact of a functional promoter polymorphism (NOS1-ex1f-VNTR) on human anxiety-related phenotypes in a total of 1019 healthy controls in five different studies. Homozygous carriers of the NOS1-ex1f short-allele displayed enhanced trait anxiety, worrying and depression scores. Furthermore, short-allele carriers were characterized by increased anxious apprehension during contextual fear conditioning. While autonomous measures (fear-potentiated startle) provided only suggestive evidence for a modulatory role of NOS1-ex1f-VNTR on (contextual) fear conditioning processes, neural activation at the amygdala/anterior hippocampus junction was significantly increased in short-allele carriers during context conditioning. Notably, this could not be attributed to morphological differences. In accordance with data from a plethora of rodent studies, we here provide converging evidence from behavioral, subjective, psychophysiological and neuroimaging studies in large human cohorts that NOS-I plays an important role in anxious apprehension but provide only limited evidence for a role in (contextual) fear conditioning. PMID:26746182

  4. Converging evidence for an impact of a functional NOS gene variation on anxiety-related processes.

    PubMed

    Kuhn, Manuel; Haaker, Jan; Glotzbach-Schoon, Evelyn; Schümann, Dirk; Andreatta, Marta; Mechias, Marie-Luise; Raczka, Karolina; Gartmann, Nina; Büchel, Christian; Mühlberger, Andreas; Pauli, Paul; Reif, Andreas; Kalisch, Raffael; Lonsdorf, Tina B

    2016-05-01

    Being a complex phenotype with substantial heritability, anxiety and related phenotypes are characterized by a complex polygenic basis. Thereby, one candidate pathway is neuronal nitric oxide (NO) signaling, and accordingly, rodent studies have identified NO synthase (NOS-I), encoded by NOS1, as a strong molecular candidate for modulating anxiety and hippocampus-dependent learning processes. Using a multi-dimensional and -methodological replication approach, we investigated the impact of a functional promoter polymorphism (NOS1-ex1f-VNTR) on human anxiety-related phenotypes in a total of 1019 healthy controls in five different studies. Homozygous carriers of the NOS1-ex1f short-allele displayed enhanced trait anxiety, worrying and depression scores. Furthermore, short-allele carriers were characterized by increased anxious apprehension during contextual fear conditioning. While autonomous measures (fear-potentiated startle) provided only suggestive evidence for a modulatory role of NOS1-ex1f-VNTR on (contextual) fear conditioning processes, neural activation at the amygdala/anterior hippocampus junction was significantly increased in short-allele carriers during context conditioning. Notably, this could not be attributed to morphological differences. In accordance with data from a plethora of rodent studies, we here provide converging evidence from behavioral, subjective, psychophysiological and neuroimaging studies in large human cohorts that NOS-I plays an important role in anxious apprehension but provide only limited evidence for a role in (contextual) fear conditioning.

  5. The role of eNOS phosphorylation in causing drug-induced vascular injury.

    PubMed

    Tobin, Grainne A McMahon; Zhang, Jun; Goodwin, David; Stewart, Sharron; Xu, Lin; Knapton, Alan; González, Carlos; Bancos, Simona; Zhang, Leshuai; Lawton, Michael P; Enerson, Bradley E; Weaver, James L

    2014-06-01

    Previously we found that regulation of eNOS is an important part of the pathogenic process of Drug-induced vascular injury (DIVI) for PDE4i. The aims of the current study were to examine the phosphorylation of eNOS in mesentery versus aorta at known regulatory sites across DIVI-inducing drug classes and to compare changes across species. We found that phosphorylation at S615 in rats was elevated 35-fold 2 hr after the last dose of CI-1044 in mesentery versus 3-fold in aorta. Immunoprecipitation studies revealed that many of the upstream regulators of eNOS activation were associated with eNOS in 1 or more signalosome complexes. Next rats were treated with drugs from 4 other classes known to cause DIVI. Each drug was given alone and in combination with SIN-1 (NO donor) or L-NAME (eNOS inhibitor), and the level of eNOS phosphorylation in mesentery and aorta tissue was correlated with the extent of vascular injury and measured serum nitrite. Drugs or combinations produced altered serum nitrite levels as well as vascular injury score in the mesentery. The results suggested that phosphorylation of S615 may be associated with DIVI activity. Studies with the species-specific A2A adenosine agonist CI-947 in rats versus primates showed a similar pattern.

  6. Fenofibrate activates AMPK and increases eNOS phosphorylation in HUVEC

    SciTech Connect

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

    2006-03-24

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

  7. Effects of simvastatin on the expression of inducible NOS in acute lung injury in septic rats

    PubMed Central

    Li, Wei-Chao; Zou, Zi-Jun; Zhou, Ming-Gen; Chen, Liang; Zhou, Lin; Zheng, Yu-Kai; He, Zhi-Jie

    2015-01-01

    Background: The available evidence suggests that simvastatin plays a beneficial role in lung injury. In addition, statins have been shown to inhibit the activity of inducible nitric oxide synthase (iNOS). The aim of the present study was to investigate the effects of simvastatin on iNOS expression based on a lipopolysaccharide (LPS)-induced septic rat model. Methods: Thirty-six rats were randomly divided into 3 groups (control group, sepsis group and simvastatin group). A rat model of sepsis was established with LPS. The simvastatin group was pre-treated with simvastatin, whereas the control and sepsis groups were treated with saline before LPS treatment. LPS was injected into the rats in the simvastatin and sepsis groups, while as a negative control, the control group received saline alone. The oxygenation index, expression levels of iNOS and IL-6, and pathological integral of lung injury were analyzed to evaluate the effect of simvastatin on septic rats. Results: Compared with the septic group, significant decreases in the oxygenation index and expression level of iNOS were observed in the simvastatin group. Furthermore, simvastatin treatment resulted in a significant decrease in iNOS levels and the pathological integral of lung injury score in septic rats. Conclusion: Simvastatin can relieve acute lung injury induced by sepsis in rats. Decreasing iNOS levels may contribute to the protective role of simvastatin in lung injury. PMID:26823851

  8. Disrupted NOS signaling in lymphatic endothelial cells exposed to chronically increased pulmonary lymph flow.

    PubMed

    Datar, Sanjeev A; Gong, Wenhui; He, Youping; Johengen, Michael; Kameny, Rebecca J; Raff, Gary W; Maltepe, Emin; Oishi, Peter E; Fineman, Jeffrey R

    2016-07-01

    Associated abnormalities of the lymphatic circulation are well described in congenital heart disease. However, their mechanisms remain poorly elucidated. Using a clinically relevant ovine model of a congenital cardiac defect with chronically increased pulmonary blood flow (shunt), we previously demonstrated that exposure to chronically elevated pulmonary lymph flow is associated with: 1) decreased bioavailable nitric oxide (NO) in pulmonary lymph; and 2) attenuated endothelium-dependent relaxation of thoracic duct rings, suggesting disrupted lymphatic endothelial NO signaling in shunt lambs. To further elucidate the mechanisms responsible for this altered NO signaling, primary lymphatic endothelial cells (LECs) were isolated from the efferent lymphatic of the caudal mediastinal node in 4-wk-old control and shunt lambs. We found that shunt LECs (n = 3) had decreased bioavailable NO and decreased endothelial nitric oxide synthase (eNOS) mRNA and protein expression compared with control LECs (n = 3). eNOS activity was also low in shunt LECs, but, interestingly, inducible nitric oxide synthase (iNOS) expression and activity were increased in shunt LECs, as were total cellular nitration, including eNOS-specific nitration, and accumulation of reactive oxygen species (ROS). Pharmacological inhibition of iNOS reduced ROS in shunt LECs to levels measured in control LECs. These data support the conclusion that NOS signaling is disrupted in the lymphatic endothelium of lambs exposed to chronically increased pulmonary blood and lymph flow and may contribute to decreased pulmonary lymphatic bioavailable NO.

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

    PubMed

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

    2016-01-01

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

  10. The Complex Role of iNOS in Acutely-Rejecting Cardiac Transplants

    PubMed Central

    Pieper, Galen M.; Roza, Allan M.

    2008-01-01

    This review summarizes the evidence for a detrimental role of nitric oxide (NO) derived from inducible NO synthase (iNOS) and/or reactive nitrogen species such as peroxynitrite in acutely-rejecting cardiac transplants. In chronic cardiac transplant rejection, iNOS may have an opposing beneficial component. The purpose of this review is primarily to address issues related to acute rejection which is a recognized risk factor for chronic rejection. The evidence for a detrimental role is based upon strategies involving non-selective NOS inhibitors, NO neutralizers, selective iNOS inhibitors and iNOS gene deletion in rodent models of cardiac rejection. The review is discussed in the context of the impact on various components including graft survival, histological rejection and cardiac function which may contribute in toto to the process of graft rejection. Possible limitations of each strategy are discussed in order to understand better the variance in published findings including issues related to the potential importance of cell localization of iNOS expression. Finally, the concept of a dual role of NO and its down-stream product, peroxynitrite, in rejection vs. immune regulation is discussed. PMID:18291116

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

    NASA Astrophysics Data System (ADS)

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

    2016-02-01

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

  12. 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).

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

    SciTech Connect

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

    2010-10-15

    Endothelial apoptosis is a driving force in atherosclerosis development. Oxidized low-density lipoprotein (oxLDL) promotes inflammatory and thrombotic processes and is highly atherogenic, as it stimulates macrophage cholesterol accumulation and foam cell formation. Previous studies have shown that the phosphatidylinositol 3-kinase/Akt/endothelial nitric oxide synthase/nitric oxide (PI3K/Akt/eNOS/NO) pathway is involved in oxLDL-induced endothelial apoptosis. Ellagic acid, a natural polyphenol found in berries and nuts, has in recent years been the subject of intense research within the fields of cancer and inflammation. However, its protective effects against oxLDL-induced injury in vascular endothelial cells have not been clarified. In the present study, we investigated the anti-apoptotic effect of ellagic acid in human umbilical vein endothelial cells (HUVECs) exposed to oxLDL and explored the possible mechanisms. Our results showed that pretreatment with ellagic acid (5-20 {mu}M) significantly attenuated oxLDL-induced cytotoxicity, apoptotic features, and generation of reactive oxygen species (ROS). In addition, the anti-apoptotic effect of ellagic acid was partially inhibited by a PI3K inhibitor (wortmannin) and a specific eNOS inhibitor (cavtratin) but not by an ERK inhibitor (PD98059). In exploring the underlying mechanisms of ellagic acid action, we found that oxLDL decreased Akt and eNOS phosphorylation, which in turn activated NF-{kappa}B and downstream pro-apoptotic signaling events including calcium accumulation, destabilization of mitochondrial permeability, and disruption of the balance between pro- and anti-apoptotic Bcl-2 proteins. Those alterations induced by oxLDL, however, were attenuated by pretreatment with ellagic acid. The inhibition of oxLDL-induced endothelial apoptosis by ellagic acid is due at least in part to its anti-oxidant activity and its ability to modulate the PI3K/Akt/eNOS signaling pathway.

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

    NASA Astrophysics Data System (ADS)

    Sweeney, Sophia Jean

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

  15. Learning to teach the nature of science: A study of preservice teachers

    NASA Astrophysics Data System (ADS)

    Ochanji, Moses Keya

    Based on Shulman's (1986) theory that teaching requires specialized knowledge referred to as pedagogical content knowledge (PCK), this study sought to explore factors that mediate between the translation of their understanding of nature of science (NOS) and its teaching, and the nature of the knowledge required to teach the NOS. Participants were 17 preservice science teachers enrolled at three different universities in similar science education programs and undergoing student teaching experiences. They were observed teaching, and also interviewed during and after student teaching experiences. Artifacts used by in teaching were also collected as data sources. An open-ended questionnaire designed to assess their conceptions of the NOS was also used. Results indicated that beyond the struggles of classroom management, working under the controlled environment of a host teacher and unfamiliar school circumstances, the PCK necessary for teaching NOS was not sufficiently developed among these teachers. They exhibited significant content knowledge of NOS and teaching methodology. However, the pedagogical knowledge necessary for teaching NOS was either misconceptualized or lacking. An assumption that NOS is learned implicitly through inquiry activities dominated their understanding of how to teach NOS. Thus most incidences where NOS was taught were through inquiry learning with lack of reflection on the implications of the inquiry process to the generation of scientific knowledge. In order to help the preservice teachers cross the bridge between preservice and in-service teaching, education programs need to offer more than a rudimentary or superficial knowledge and understanding of various aspects of NOS. For instance, it is not enough for preservice teachers to "know" that scientific knowledge is socially and culturally embedded. They should be able to use examples and/or simplified case histories from scientific practice to substantiate this claim and make it accessible

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

    NASA Astrophysics Data System (ADS)

    McDowell, Amy Virginia

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-10-01

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

  18. Influence of coronary artery diameter on eNOS protein content

    NASA Technical Reports Server (NTRS)

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

    2003-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    2001-01-01

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

  20. Daily exercise normalizes the number of diaphorase (NOS) positive neurons in the hypothalamus of hypertensive rats.

    PubMed

    DiCarlo, Stephen E; Zheng, H; Collins, Heidi L; Rodenbaugh, David W; Patel, Kaushik P

    2002-11-15

    It is well known that nitric oxide (NO), within the paraventricular nucleus (PVN) of the hypothalamus, mediates sympatho-inhibition via an inhibitory GABA-ergic mechanism. Furthermore, the inhibitory GABA-ergic mechanism is impaired in the spontaneously hypertensive rat (SHR). These data suggest that the NO system, within the PVN, may also be impaired in the SHR. In addition, previous studies have documented that daily exercise attenuates the development of tachycardia, hypertension and blood pressure related cardiovascular disease risk factors in SHR. These data suggest that daily exercise enhances the inhibitory GABA-ergic and/or NO systems. Therefore, this study was designed to test the hypothesis that hypertension, in the SHR, is associated with a lower number of NADPH-diaphorase (a commonly used marker for neuronal NOS activity) positive neurons within the PVN and that daily exercise increases the number of NOS positive neurons. Using a standard histochemical protocol, NOS positive neurons were measured in the PVN, supraoptic nucleus, median preoptic area, lateral hypothalamus, nucleus of the tractus solitarius and rostral ventrolateral medulla. Results document that SHR have significantly fewer NOS-positive neurons in the PVN than their genetic control, the Wistar-Kyoto (WKY) rats (110+/-11 versus 139+/-17). Furthermore, daily exercise increased the number of NOS positive neurons in the SHR to levels seen in the WKY rats. These data demonstrate that hypertension, in the SHR, is associated with a lower number of NOS positive neurons within the PVN and that daily exercise increases the number of NOS positive neurons within the PVN.

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

    SciTech Connect

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

    2015-01-02

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

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

    NASA Astrophysics Data System (ADS)

    Mesci, Gunkut; Schwartz, Renee'S.

    2016-02-01

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

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

    SciTech Connect

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

    2012-02-01

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

  4. Outcome after BCG treatment for urinary bladder cancer may be influenced by polymorphisms in the NOS2 and NOS3 genes☆

    PubMed Central

    Ryk, Charlotta; Koskela, Lotta Renström; Thiel, Tomas; Wiklund, N. Peter; Steineck, Gunnar; Schumacher, Martin C.; de Verdier, Petra J.

    2015-01-01

    Purpose Bacillus Calmette-Guérin (BCG)-treatment is an established treatment for bladder cancer, but its mechanisms of action are not fully understood. High-risk non-muscle invasive bladder-cancer (NMIBC)-patients failing to respond to BCG-treatment have worse prognosis than those undergoing immediate radical cystectomy and identification of patients at risk for BCG-failure is of high priority. Several studies indicate a role for nitric oxide (NO) in the cytotoxic effect that BCG exerts on bladder cancer cells. In this study we investigated whether NO-synthase (NOS)-gene polymorphisms, NOS2-promoter microsatellite (CCTTT)n, and the NOS3-polymorphisms-786T>C (rs2070744) and Glu298Asp (rs1799983), can serve as possible molecular markers for outcome after BCG-treatment for NMIBC. Materials and methods All NMIBC-patients from a well-characterized population based cohort were analyzed (n=88). Polymorphism data were combined with information from 15-years of clinical follow-up. The effect of BCG-treatment on cancer-specific death (CSD), recurrence and progression in patients with varying NOS-genotypes were studied using Cox proportional hazard-models and log rank tests. Results BCG-treatment resulted in significantly better survival in patients without (Log rank: p=0.006; HR: 0.12, p=0.048), but not in patients with a long version ((CCTTT)n ≧13 repeats) of the NOS2-promoter microsatellite. The NOS3-rs2070744(TT) and rs1799983(GG)-genotypes showed decreased risk for CSD (Log rank(TT): p=0.001; Log rank(GG): p=0.010, HR(GG): 0.16, p=0.030) and progression (Log rank(TT): p<0.001, HR(TT): 0.05, p=0.005; Log rank(GG): p<0.001, HR(GG): 0.10, p=0.003) after BCG-therapy compared to the other genotypes. There was also a reduction in recurrence in BCG-treated patients that was mostly genotype independent. Analysis of combined genotypes identified a subgroup of 30% of the BCG-treated patients that did not benefit from BCG-treatment. Conclusions Our results suggest that the

  5. Transcriptional regulation of the human iNOS gene by IL-1beta in endothelial cells.

    PubMed Central

    Kolyada, A. Y.; Madias, N. E.

    2001-01-01

    BACKGROUND: Vascular endothelium participates in the control of vascular tone and function via the release of nitric oxide (NO) by the endothelial-type NO synthase (eNOS). Inducible NO synthase (iNOS) expression in endothelial cells occurs in many clinical conditions following induction by lipopolysaccharide or cytokines and generates large quantities of NO that result in endothelial cell activation and dysfunction. No information exists on the transcriptional regulation of the human iNOS gene (or that of other species) in endothelial cells. MATERIALS AND METHODS: We examined the transcriptional regulation of the human iNOS gene by interleukin-1beta (IL-1beta) in rat pulmonary microvascular endothelial cells (PVEC) by transient cotransfections of different iNOS-promoter constructs and cDNA of different transcription factors and regulatory proteins. RESULTS: The -1034/+88 bp iNOS promoter was strongly induced by IL-1beta, the regulatory elements for such induction being localized downstream of -205 bp. Cotransfection experiments with NF-kappaB isoforms, IkappaB isoforms, and IKK mutants suggested that the NF-kappaB site at -115/-106 bp is important, but not sufficient, for induction of iNOS promoter and that the role of NF-kappaB is partially independent of its binding site. C/EBP sites within the -205/+88 bp region were shown to be responsible, along with NF-kappaB site, for induction of iNOS promoter by IL-1beta. Overexpression of C/EBPalpha, C/EBPdelta, and liver-enriched activator protein (LAP) activated the promoter, whereas overexpression of liver-enriched inhibitory protein (LIP) strongly suppressed it. C/EBPbeta (LAP and LIP isoforms) was constitutively present in PVEC and was induced (approximately 2-fold) by IL-1beta, whereas C/EBPdelta was not constitutively expressed but was strongly induced by IL-1beta. Both C/EBPbeta and C/EBPdelta participated in DNA-protein complex formation. CONCLUSION: Both NF-kappaB and C/EBP pathways are important for the

  6. Beneficial effect of Sparassis crispa on stroke through activation of Akt/eNOS pathway in brain of SHRSP

    PubMed Central

    Yoshitomi, Hisae; Iwaoka, Emiko; Kubo, Masahide; Shibata, Masaru

    2010-01-01

    Sparassis crispa (S. crispa) is a mushroom used as a natural medicine that recently became cultivatable in Japan. In this study, we investigated not only the preventive effects of S. crispa against stroke and hypertension in stroke-prone spontaneously hypertensive rats (SHRSP) but also the mechanism involved by using studies of the cerebral cortex at a young age. Six-week-old male SHRSP were divided into 2 groups, a control group and an S. crispa group administered 1.5% S. crispa in feed, and we then observed their survival. In addition, rats of the same age were treated with 1.5% S. crispa for 4 weeks and we measured body weight, blood pressure, blood flow from the tail, NOx production, and the levels of expression of several proteins in the cerebral cortex by western blot analysis. Our results showed that the S. crispa group had a delayed incidence of stroke and death and significantly decreased blood pressure and increased blood flow after the administration. Moreover, the quantity of urinary excretion and the nitrate/nitrite concentration in cerebral tissue were higher than those of control SHRSP rats. In the cerebral cortex, phosphor-eNOS (Ser1177) and phosphor-Akt (Ser473) in S. crispa-treated SHRSP were increased compared with those of control SHRSP rats. In conclusion, S. crispa could ameliorate cerebrovascular endothelial dysfunction by promoting recovery of Akt-dependent eNOS phosphorylation and increasing NO production in the cerebral cortex. S. crispa may be useful for preventing stroke and hypertension. PMID:21076883

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

    PubMed Central

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

    2012-01-01

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

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

    SciTech Connect

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

    2015-08-07

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

  9. As an Infused or a Separated Theme? Chinese Science Teacher Educators' Conceptions of Incorporating Nature of Science Instruction in the Courses of Training Pre-Service Science Teachers

    ERIC Educational Resources Information Center

    Wan, Zhi Hong; Wong, Siu Ling

    2013-01-01

    Teaching nature of science (NOS) is beginning to find its place in science education in China. This exploratory study interviewed twenty-four Chinese science teacher educators about their conceptions of teaching NOS to pre-service science teachers. Although five dimensions emerged, this paper mainly focuses on reporting the findings relevant to…

  10. Induction of endothelial iNOS by 4-hydroxyhexenal through NF-kappaB activation.

    PubMed

    Lee, J Y; Je, J H; Jung, K J; Yu, B P; Chung, H Y

    2004-08-15

    Lipid peroxidation and its end-product, 4-hydroxyhexenal (HHE), are known to affect redox balance during aging, which causes various degenerative processes including vascular alterations from endothelial cell deterioration. To better understand the molecular action of HHE in the development of vascular abnormalities during the aging process, we investigated whether the upregulation of inducible endothelial nitric oxide synthase (iNOS) by HHE is mediated through nuclear factor kappaB (NF-kappaB) activation. Results indicate that HHE stimulates iNOS by the transcriptional regulation of NF-kappaB activation through cytosolic kappaB degradation inhibitors (IkappaB). Pretreatment with NF-kappaB inhibitors Bay 11-7082 and N-acetyl cysteine (NAC) suppressed the upregulation of iNOS by blunting IkappaB degradation and NF-kappaB binding activity. Because inflammatory stimuli induce iNOS to generate large amounts of nitric oxide (NO), intracellular NO levels in the presence of Bay 11-7082, NAC, and caffeic acid methyl ester were estimated. These inhibitors significantly suppressed the HHE-induced NO levels to a basal level. These findings strongly suggest that in endothelial cells, HHE induces iNOS gene expression through NF-kappaB activation, which can lead to vascular dysfunction by the activation of various proinflammatory genes.

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

    PubMed Central

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

    2015-01-01

    There is considerable interest in implantation techniques and scaffolds for tissue engineering and, for safety and biocompatibility reasons, inflammation, angiogenesis, and fibrosis need to be determined. The contribution of inducible nitric oxide synthase (iNOS) in the regulation of the foreign body reaction induced by subcutaneous implantation of a synthetic matrix was never investigated. Here, we examined the role of iNOS in angiogenesis, inflammation, and collagen deposition induced by polyether-polyurethane synthetic implants, using mice with targeted disruption of the iNOS gene (iNOS−/−) and wild-type (WT) mice. The hemoglobin content and number of vessels were decreased in the implants of iNOS−/− mice compared to WT mice 14 days after implantation. VEGF levels were also reduced in the implants of iNOS−/− mice. In contrast, the iNOS−/− implants exhibited an increased neutrophil and macrophage infiltration. However, no alterations were observed in levels of CXCL1 and CCL2, chemokines related to neutrophil and macrophage migration, respectively. Furthermore, the implants of iNOS−/− mice showed boosted collagen deposition. These data suggest that iNOS activity controls inflammation, angiogenesis, and fibrogenesis in polyether-polyurethane synthetic implants and that lack of iNOS expression increases foreign body reaction to implants in mice. PMID:26106257

  12. Sociodemographic, neuropsychiatric and cognitive characteristics of pathological gambling and impulse control disorders NOS in Parkinson's disease.

    PubMed

    Pontieri, Francesco E; Assogna, Francesca; Pellicano, Clelia; Cacciari, Claudia; Pannunzi, Sara; Morrone, Annalucia; Danese, Emanuela; Caltagirone, Carlo; Spalletta, Gianfranco

    2015-01-01

    Despite of previous evidence supporting the association between impulse control disorder (ICD) and several demographic, clinical and therapeutic features in Parkinson's disease (PD), the relationships between pathological gambling (PG) or other variants of ICD (ICD-NOS) and specific neuropsychiatric or cognitive domains are not entirely defined. In this study, 155 PD patients without dementia or cognitive impairment underwent: i. the ICD diagnoses, using the Questionnaire for Impulsive-Compulsive Disorders, ii. the mood and anxiety disorders diagnoses, according to the DSM-IV-TR criteria, and iii. a comprehensive battery for measuring severity of psychopathology and neuropsychology domains. Patients were divided in those with pathological gambling (PG), ICDs not otherwise specified (ICD-NOS), or the lack of ICD (No-ICD). There was a progression in age and age at onset from the younger PG subjects throughout ICD-NOS to No-ICD. PG and ICD-NOS subjects had longer disease duration and were taking significantly higher dosages of antiparkinsonian drugs than No-ICD ones. PG subjects had significantly higher severity of depressive and anxious symptoms with respect to the other 2 groups. Both PG and ICD-NOS subjects suffer from increased severity of psychotic symptoms than No-ICD ones. The 3 groups did not differ in any cognitive measure. Our results support the concept that the different sociodemographic and neuropsychiatric profiles of PD patients are associated with different ICDs. Moreover, we clearly demonstrate the lack of relationship between ICD and cognitive performances in undemented PD patients.

  13. Innervation of vasculature and microvasculature of the human vagina by NOS and neuropeptide-containing nerves.

    PubMed Central

    Hoyle, C H; Stones, R W; Robson, T; Whitley, K; Burnstock, G

    1996-01-01

    The aims of the present study were to determine whether nerves that contain nitric oxide synthase (NOS), calcitonin gene-related peptide (CGRP) or substance P (SP) are present in the human vagina and, if so, to determine the pattern of innervation relative to that of other neurotransmitters, particularly vasoactive intestinal polypeptide (VIP) and neuropeptide Y (NPY). Surgical specimens of vaginal tissue (n = 10) from pre- and postmenopausal women were fixed and processed for immunohistochemistry of peptides and NOS and for histochemistry of NADPH-diaphorase. SP-immunoreactive nerves were very sparse, being absent from 9 of the 10 tissue samples. For other peptides and NOS, the innervation of the deep arteries and veins was greater than that of blood vessels in the propria. Capillaries in the epithelial papillae also appeared to be innervated by nerves containing NOS, CGRP, NPY and VIP. Beneath the epithelium nerve fibres formed a subepithelial plexus; no nerve cell bodies were seen. The relative density of innervation by immunoreactive fibres was PGP-9.5 > NPY > VIP >> NOS > CGRP > SP. These results imply that nerves that utilise nitric oxide or NPY, VIP or CGRP as a neurotransmitter may play a role in controlling blood flow and capillary permeability in the human vagina. The origin and function of all these nerves is discussed. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 PMID:8763480

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

    NASA Astrophysics Data System (ADS)

    Dewnarain Ramnarain, Umesh; Chanetsa, Tarisai

    2016-04-01

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

  15. [Natural selection].

    PubMed

    Mayr, E

    1985-05-01

    Much of the resistance against Darwin's theory of natural selection has been due to misunderstandings. It is shown that natural selection is not a tautology and that it is a two-step process. The first step, the production of variation, is under the control of chance; the second step, selection proper, is an anti-chance process, but subject to many constraints. The target of selection is the individual as a whole, and many neutral mutations can be retained as hitchhikers of successful genotypes. Sexual selection results from selection for pure reproductive success.

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

    PubMed Central

    Cutucache, Christine E.; Herek, Tyler A.

    2016-01-01

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

  17. [NOS UNCOUPLING IS ACCOMPANIED WITH INDUCTION OF THE OXIDATIVE STRESS AND THE CARDIOHEMODYNAMICS DISTURBANCES IN HYPERTENSION].

    PubMed

    Kotsuruba, A V; Dorofeyeva, N A; Sagach, V F

    2015-01-01

    We compared the performance of cardiaohemodynamics and indicators of oxidative and nitrosative stress in the heart and aorta in normotensive Wistar rats (WKR) and spontaneously hypertensive rats (SHR). On the basis of experimentally determined parameters to calculate cNOS uncoupling index and biochemical index of function (BIF) in these organs of the cardiovascular system. In the heart, and especially in the aorta of SHR develop a combined oxidative and nitrosative stress that leads to cNOS uncoupling, BIF lowering that correlate with lowering of systolic and diastolic functions, inhibition of the efficiency Frank-Starling mechanism, oxygen consumption of the heart and increasing arterial stiffness. We made the assumption of the existence of the vicious circle of enhancing oxidative stress in organs of the cardiovascular system due to additional superoxide generation by uncoupling cNOS. PMID:26495730

  18. Two functionally distinct pools of eNOS in endothelium are facilitated by myoendothelial junction lipid composition.

    PubMed

    Biwer, Lauren A; Taddeo, Evan P; Kenwood, Brandon M; Hoehn, Kyle L; Straub, Adam C; Isakson, Brant E

    2016-07-01

    In resistance arteries, endothelial cells (EC) make contact with smooth muscle cells (SMC), forming myoendothelial junctions (MEJ). Endothelial nitric oxide synthase (eNOS) is present in the luminal side of the EC (apical EC) and the basal side of the EC (MEJ). To test if these eNOS pools acted in sync or separately, we co-cultured ECs and SMCs, then stimulated SMCs with phenylephrine (PE). Adrenergic activation causes inositol [1,4,5] triphosphate (IP3) to move from SMC to EC through gap junctions at the MEJ. PE increases MEJ eNOS phosphorylation (eNOS-P) at S1177, but not in EC. Conversely, we used bradykinin (BK) to increase EC calcium; this increased EC eNOS-P but did not affect MEJ eNOS-P. Inhibiting gap junctions abrogated the MEJ eNOS-P after PE, but had no effect on BK eNOS-P. Differential lipid composition between apical EC and MEJ may account for the compartmentalized eNOS-P response. Indeed, DAG and phosphatidylserine are both enriched in MEJ. These lipids are cofactors for PKC activity, which was significantly increased at the MEJ after PE. Because PKC activity also relies on endoplasmic reticulum (ER) calcium release, we used thapsigargin and xestospongin C, BAPTA, and PKC inhibitors, which caused significant decreases in MEJ eNOS-P after PE. Functionally, BK inhibited leukocyte adhesion and PE caused an increase in SMC cGMP. We hypothesize that local lipid composition of the MEJ primes PKC and eNOS-P for stimulation by PE, allowing for compartmentalized function of eNOS in the blood vessel wall. PMID:27106139

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

    PubMed Central

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

    2014-01-01

    ABSTRACT Microbial activities in soils, such as (incomplete) denitrification, represent major sources of nitrous oxide (N2O), a potent greenhouse gas. The key enzyme for mitigating N2O emissions is NosZ, which catalyzes N2O reduction to N2. We recently described “atypical” functional NosZ proteins encoded by both denitrifiers and nondenitrifiers, which were missed in previous environmental surveys (R. A. Sanford et al., Proc. Natl. Acad. Sci. U. S. A. 109:19709–19714, 2012, doi:10.1073/pnas.1211238109). Here, we analyzed the abundance and diversity of both nosZ types in whole-genome shotgun metagenomes from sandy and silty loam agricultural soils that typify the U.S. Midwest corn belt. First, different search algorithms and parameters for detecting nosZ metagenomic reads were evaluated based on in silico-generated (mock) metagenomes. Using the derived cutoffs, 71 distinct alleles (95% amino acid identity level) encoding typical or atypical NosZ proteins were detected in both soil types. Remarkably, more than 70% of the total nosZ reads in both soils were classified as atypical, emphasizing that prior surveys underestimated nosZ abundance. Approximately 15% of the total nosZ reads were taxonomically related to Anaeromyxobacter, which was the most abundant genus encoding atypical NosZ-type proteins in both soil types. Further analyses revealed that atypical nosZ genes outnumbered typical nosZ genes in most publicly available soil metagenomes, underscoring their potential role in mediating N2O consumption in soils. Therefore, this study provides a bioinformatics strategy to reliably detect target genes in complex short-read metagenomes and suggests that the analysis of both typical and atypical nosZ sequences is required to understand and predict N2O flux in soils. PMID:24895307

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

    PubMed Central

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

    2016-01-01

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

  1. Dynamin-2 is a novel NOS1β interacting protein and negative regulator in the collecting duct.

    PubMed

    Hyndman, Kelly A; Arguello, Alexandra M; Morsing, Sofia K H; Pollock, Jennifer S

    2016-04-01

    Nitric oxide synthase 1 (NOS1)-derived nitric oxide (NO) production in collecting ducts is critical for maintaining fluid-electrolyte balance. Rat collecting ducts express both the full-length NOS1α and its truncated variant NOS1β, while NOS1β predominates in mouse collecting ducts. We reported that dynamin-2 (DNM2), a protein involved in excising vesicles from the plasma membrane, and NOS1α form a protein-protein interaction that promotes NO production in rat collecting ducts. NOS1β was found to be highly expressed in human renal cortical/medullary samples; hence, we tested the hypothesis that DNM2 is a positive regulator of NOS1β-derived NO production. COS7 and mouse inner medullary collecting duct-3 (mIMCD3) cells were transfected with NOS1β and/or DNM2. Coimmunoprecipitation experiments show that NOS1β and DNM2 formed a protein-protein interaction. DNM2 overexpression decreased nitrite production (index of NO) in both COS7 and mIMCD-3 cells by 50-75%. mIMCD-3 cells treated with a panel of dynamin inhibitors or DNM2 siRNA displayed increased nitrite production. To elucidate the physiological significance of IMCD DNM2/NOS1β regulation in vivo, flox control and CDNOS1 knockout mice were placed on a high-salt diet, and freshly isolated IMCDs were treated acutely with a dynamin inhibitor. Dynamin inhibition increased nitrite production by IMCDs from flox mice. This response was blunted (but not abolished) in collecting duct-specific NOS1 knockout mice, suggesting that DNM2 also negatively regulates NOS3 in the mouse IMCD. We conclude that DNM2 is a novel negative regulator of NO production in mouse collecting ducts. We propose that DNM2 acts as a "break" to prevent excess or potentially toxic NO levels under high-salt conditions. PMID:26791826

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

    PubMed Central

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

    2016-01-01

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

  3. 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

  4. 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…

  5. 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…

  6. 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.

  7. 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.

  8. Different expression of NOS isoforms in early endothelial progenitor cells derived from peripheral and cord blood.

    PubMed

    Muscari, Claudio; Gamberini, Chiara; Carboni, Marco; Basile, Ilaria; Farruggia, Giovanna; Bonafè, Francesca; Giordano, Emanuele; Caldarera, Claudio Marcello; Guarnieri, Carlo

    2007-11-01

    Cord blood and peripheral-adult blood were compared as different sources of early endothelial precursor cells (eEPCs). Total mononuclear cells (MNCs) were obtained from both blood types and committed to eEPCs by exposure to fibronectin, VEGF, IGF-I, and bFGF. Under this condition, MNCs seeded at the density of 3 x 10(5) cells/cm(2) assumed a spindle shape, which was indicative of developing eEPCs, and expanded in a similar manner irrespective to the blood sources. Ulex europaeus agglutinin (UEA-1) and acetylated low density lipoprotein (acLDL) double staining was present in 90% in both peripheral- and cord-blood eEPCs after 2-week expansion. Also, the ability of eEPCs to form tubule-like structures in Matrigel was independent of their blood source, but dependent on the presence of human umbilical vein endothelial cells (HUVECs). eNOS and nNOS were not detectable by Western blotting in both peripheral and cord-blood eEPCs upon 3 weeks and their mRNA levels were lower than 2% relative to those present in HUVECs. On the contrary, iNOS protein was detectable in peripheral-blood eEPCs, but not in cord-blood eEPCs and HUVECs, as well as iNOS mRNA was more concentrated in peripheral-blood eEPCs than in cord-blood eEPCs and HUVECs. These data suggest that: (a) peripheral and cord blood can be considered comparable sources of eEPCs when they are expanded and differentiated in a short-term period; (b) the extremely low expression of constitutive NOS isoforms in the eEPCs of both blood types should markedly reduce their ability to regulate NO-dependent vasorelaxation; (c) the presence of iNOS in peripheral-blood eEPCs could improve the process of vasculogenesis.

  9. Relationship of bovine NOS2 gene polymorphisms to the risk of bovine tuberculosis in Holstein cattle.

    PubMed

    Cheng, Yafen; Huang, ChenShen; Tsai, Hsiang-Jung

    2016-02-01

    Many studies suggest significant genetic variation in the resistance of cattle and humans to infection with Mycobacterium bovis, the causative agent of zoonotic tuberculosis. The inducible nitric oxide synthase (iNOS which is encoded by the NOS2 gene) plays a key role in the immunological control of a broad spectrum of infectious agents. This study aimed to investigate the influence of genetic variations in the promoter of the NOS2 gene on bovine tuberculosis (bTB) susceptibility. In this study, the NOS2 genes of 74 bTB-infected Holstein cows and 90 healthy controls were genotyped using PCR followed by nucleotide sequencing. Polymorphisms at rs207692718, rs109279434, rs209895548, rs385993919, rs433717754, rs383366213, rs466730386, rs715225976, rs525673647, rs720757654 and g.19958101T>G in the promoter region of the NOS2 gene were detected. The g.19958101T>G SNP produced two different conformation patterns (TT and TG) and the TG genotype was over-represented in the bTB group (20.27%) compared with the control group (2.22%). The TG genotype frequency of the g.19958101T>G variant was significantly higher in bTB cattle than in healthy controls (OR, 11.19; 95% CI, 2.47-50.73; P=0.0002). The G allele of the g.19958101T>G polymorphism was more frequent in bTB group when compared to control group (10.14% versus 1.11%). Furthermore, the G allele was a risk factor for bTB susceptibility (OR, 10.04; 95% CI, 2.26-44.65; P=0.0002). In conclusion, the g.19958101T>G polymorphism of the NOS2 gene may contribute to the susceptibility of Holstein cattle to bTB. PMID:26468216

  10. Association between NOS3 genetic variants and coronary artery disease in the Han population.

    PubMed

    Zhao, G L; Li, Q J; Lu, H Y

    2016-01-01

    The enzyme endothelial nitric oxide synthase (NOS3) is an important mediator of atherosclerotic disease and is associated with coronary artery disease (CAD). There is growing evidence that polymorphisms in NOS3 influence the progression of CAD; however, there is also a controversy regarding the association of polymorphisms in the gene encoding NOS3 and CAD. To determine if the NOS3 genetic variants are associated with CAD in the Han Chinese, we examined the potential association between CAD and eight single nucleotide polymorphisms (rs1799983, rs2070744, rs11771443, rs3918188, rs2853796, rs7830, rs1541861, and rs2853792) of the NOS3 using the MassARRAY system. The allelic and genotypic frequencies of the rs1799983 (promoter regions) and rs2070744 (intron 1) polymorphisms in patients with CAD were significantly different from those in healthy controls. These patients had significantly higher frequencies of the rs1799983 T allele (χ2 = 7.717, P = 0.007, OR = 1.649, 95%CI = 1.41-2.382) and the rs2070744 G allele (χ2 = 4.548, P = 0.033, OR = 1.490, 95%CI = 1.031-2.153). Strong linkage disequilibrium was observed in three blocks (D' > 0.9). In block 1, significantly more T-T-C haplotypes (χ2 = 5.537, P = 0.019, OR = 0.632, 95%CI = 0.430-0.927) were found in controls. These findings point to a role for NOS3 polymorphisms in CAD in the Chinese Han population, and may be useful for future investigations on the pathogenesis of CAD. PMID:27323132

  11. Changes in eNOS phosphorylation contribute to increased arteriolar NO release during juvenile growth

    PubMed Central

    Kang, Lori S.; Nurkiewicz, Timothy R.; Wu, Guoyao

    2012-01-01

    Nitric oxide (NO) mediates a major portion of arteriolar endothelium-dependent dilation in adults, but indirect evidence has suggested that NO contributes minimally to these responses in the young. Isolated segments of arterioles were studied in vitro to verify this age-related increase in NO release and investigate the mechanism by which it occurs. Directly measured NO release induced by ACh or the Ca2+ ionophore A-23187 was five- to sixfold higher in gracilis muscle arterioles from 42- to 46-day-old (juvenile) rats than in those from 25- to 28-day-old (weanling) rats. There were no differences between groups in arteriolar endothelial NO synthase (eNOS) expression or tetrahydrobiopterin levels, and arteriolar l-arginine levels were lower in juvenile vessels than in weanling vessels (104 ± 6 vs.126 ± 3 pmol/mg). In contrast, agonist-induced eNOS Thr495 dephosphorylation and eNOS Ser1177 phosphorylation (events required for maximal activity) were up to 30% and 65% greater, respectively, in juvenile vessels. Juvenile vessels did not show increased expression of enzymes that mediate these events [protein phosphatases 1 and 2A and PKA and PKB (Akt)] or heat shock protein 90, which facilitates Ser1177 phosphorylation. However, agonist-induced colocalization of heat shock protein 90 with eNOS was 34–66% greater in juvenile vessels than in weanling vessels, and abolition of this difference with geldanamycin also abolished the difference in Ser1177 phosphorylation between groups. These findings suggest that growth-related increases in arteriolar NO bioavailability may be due at least partially to changes in the regulation of eNOS phosphorylation and increased signaling activity, with no change in the abundance of eNOS signaling proteins. PMID:22140037

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

    NASA Astrophysics Data System (ADS)

    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 labeled as explicit and excerpts that partially and/or indirectly matched our statements about NOS and SI were labeled as implicit. There was a running count of each NOS and SI aspect that was identified in the textbooks and the instances were noted to be either implicit or explicit. There were 365 instances of NOS and SI aspects counted in 140 textbook excerpts. Of the 365 instances, 237 (65 %) were NOS aspects and 128 (35 %) were SI aspects. The analysis also revealed far more implicit than explicit instances of NOS and SI. Of the 365 instances, 362 (99 %) were implicit and three (1.0 %) were explicit. The three explicit instances were all SI aspects. In conclusion, the Mendelian genetics sections demonstrated a multitude of opportunities to teach NOS and SI explicitly, although what was included in textbooks was virtually all implicit. This study demonstrates the importance and value for science educators to examine how teachers use instances of NOS and SI in textbooks. Understanding how teachers use instances of NOS and SI would provide information that could be immediately implemented into professional development programs. Lastly, this research would provide textbook developers with compelling information to update the supplemental instruction materials provided to teachers.

  13. Non-viral eNOS gene delivery and transfection with stents for the treatment of restenosis

    PubMed Central

    2010-01-01

    Background In this study, we have examined local non-viral gene delivery, transfection, and therapeutic efficacy of endothelial nitric oxide synthase (eNOS) encoding plasmid DNA administered using coated stents in a rabbit iliac artery restenosis model. Methods Lipopolyplexes (LPPs) with eNOS expressing plasmid DNA were immobilized on stainless steel stents using poly(D,L-lactide-co-glycolide) (PLGA) and type B gelatin coatings. The gene-eluting stents were implanted bilaterally in the denuded iliac arteries and eNOS transfection and therapeutic efficacy were examined 14 days after implantation. Results The results show that non-viral lipopolyplex-coated stents can efficiently tranfect eNOS locally in the arterial lumen assessed by PCR and ELISA. Human eNOS ELISA levels were significantly raised 24 hours after transfection compared to controls (125 pg eNOS compared to <50 pg for all controls including naked DNA). Local eNOS production suppressed smooth muscle cell proliferation and promoted re-endothelialization of the artery showing a significant reduction in restenosis of 1.75 neointima/media ratio for stents with lipoplexes encoding eNOS compared with 2.3 neointima/media ratio for stents with lipoplexes encosing an empty vector. Conclusions These results support the hypothesis that a potent non-viral gene vector encoding for eNOS coated onto a stent can inhibit restenosis through inhibition of smooth muscle cell growth and promotion of a healthy endothelium. PMID:20875110

  14. NOS1-derived nitric oxide promotes NF-κB transcriptional activity through inhibition of suppressor of cytokine signaling-1

    PubMed Central

    Baig, Mirza Saqib; Zaichick, Sofia V.; Mao, Mao; de Abreu, Andre L.; Bakhshi, Farnaz R.; Hart, Peter C.; Saqib, Uzma; Deng, Jing; Chatterjee, Saurabh; Block, Michelle L.; Vogel, Stephen M.; Malik, Asrar B.; Consolaro, Marcia E.L.; Christman, John W.; Minshall, Richard D.

    2015-01-01

    The NF-κB pathway is central to the regulation of inflammation. Here, we demonstrate that the low-output nitric oxide (NO) synthase 1 (NOS1 or nNOS) plays a critical role in the inflammatory response by promoting the activity of NF-κB. Specifically, NOS1-derived NO production in macrophages leads to proteolysis of suppressor of cytokine signaling 1 (SOCS1), alleviating its repression of NF-κB transcriptional activity. As a result, NOS1−/− mice demonstrate reduced cytokine production, lung injury, and mortality when subjected to two different models of sepsis. Isolated NOS1−/− macrophages demonstrate similar defects in proinflammatory transcription on challenge with Gram-negative bacterial LPS. Consistently, we found that activated NOS1−/− macrophages contain increased SOCS1 protein and decreased levels of p65 protein compared with wild-type cells. NOS1-dependent S-nitrosation of SOCS1 impairs its binding to p65 and targets SOCS1 for proteolysis. Treatment of NOS1−/− cells with exogenous NO rescues both SOCS1 degradation and stabilization of p65 protein. Point mutation analysis demonstrated that both Cys147 and Cys179 on SOCS1 are required for its NO-dependent degradation. These findings demonstrate a fundamental role for NOS1-derived NO in regulating TLR4-mediated inflammatory gene transcription, as well as the intensity and duration of the resulting host immune response. PMID:26324446

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

    NASA Astrophysics Data System (ADS)

    Çil, Emine; Çepni, Salih

    2016-01-01

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

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

    PubMed

    Wang, Lei; Yang, Xiao-Song

    2015-12-01

    This letter restudies the Nosé-Hoover oscillator. Some new averagely conservative regions are found, each of which is filled with different sequences of nested tori with various knot types. Especially, the dynamical behaviors near the border of "chaotic region" and conservative regions are studied showing that there exist more complicated and thinner invariant tori around the boundaries of conservative regions bounded by tori. Our results suggest an infinite number of island chains in a "chaotic sea" for the Nosé-Hoover oscillator.

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

    PubMed Central

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

    2016-01-01

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

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

    SciTech Connect

    Wang, Lei; Yang, Xiao-Song

    2015-12-15

    This letter restudies the Nosé-Hoover oscillator. Some new averagely conservative regions are found, each of which is filled with different sequences of nested tori with various knot types. Especially, the dynamical behaviors near the border of “chaotic region” and conservative regions are studied showing that there exist more complicated and thinner invariant tori around the boundaries of conservative regions bounded by tori. Our results suggest an infinite number of island chains in a “chaotic sea” for the Nosé-Hoover oscillator.

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

    NASA Astrophysics Data System (ADS)

    Wang, Lei; Yang, Xiao-Song

    2015-12-01

    This letter restudies the Nosé-Hoover oscillator. Some new averagely conservative regions are found, each of which is filled with different sequences of nested tori with various knot types. Especially, the dynamical behaviors near the border of "chaotic region" and conservative regions are studied showing that there exist more complicated and thinner invariant tori around the boundaries of conservative regions bounded by tori. Our results suggest an infinite number of island chains in a "chaotic sea" for the Nosé-Hoover oscillator.

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

    NASA Astrophysics Data System (ADS)

    Jones, William I.

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

  1. Tetrahydrobiopterin (BH4), a cofactor for nNOS, restores gastric emptying and nNOS expression in female diabetic rats.

    PubMed

    Gangula, Pandu R R; Mukhopadhyay, Sutapa; Ravella, Kalpana; Cai, Shijie; Channon, Keith M; Garfield, Robert E; Pasricha, Pankaj J

    2010-05-01

    Gastroparesis is a debilitating disease predominantly affecting young women. Recently, dysregulation of neuronal nitric oxide synthase (nNOS) in myenteric plexus neurons has been implicated for delayed solid gastric emptying/gastroparesis in diabetic patients. In this study, we have explored the role of tetrahydrobiopterin (BH4), a major cofactor for nNOS activity and NO synthesis in diabetic gastroparesis. Diabetes was induced with single injection of streptozotocin (55 mg/kg body wt, ip) in female rats, with experiments performed on week 3 or 9 following induction, with or without 3-wk BH4 supplementation. Gastric pyloric BH4 levels were significantly decreased in diabetic female rats compared with control (18.6 +/- 1.45 vs. 31.0 +/- 2.31 pmol/mg protein). In vitro studies showed that 2,4-diamino-6-hydroxypyrimidine (DAHP), an inhibitor of BH4 synthesis, significantly decreased gastric NO release and nitrergic relaxation. Three-week dietary supplementation of BH4 either from day 1 or week 6 significantly attenuated diabetes-induced delayed gastric emptying for solids (3 wk: BH4, 67 +/- 6.7 vs. diabetic, 36.05 +/- 7.09; 9 wk: BH4, 57 +/- 8.45 vs. diabetic, 33 +/- 9.91) and diabetes-induced reduction in pyloric nNOS-alpha protein expression in female rats. Supplementation of BH4 significantly restored gastric nNOS-alpha dimerization in 9-wk-old diabetic female rats. In addition, BH4 treatment reversed (17.23 +/- 5.81 vs. 42.0 +/- 2.70 mmHg x s) the diabetes-induced changes in intragastric pressures (IGP) and gastric pyloric nitrergic relaxation (-0.62 +/- 0.01 vs. -0.22 +/- 0.07). BH4 deficiency plays a critical role in diabetes-induced alterations including delayed solid gastric emptying, increased IGP, reduced pyloric nitrergic relaxation, and nNOS-alpha expression in female rats. Supplementation of BH4 accelerates gastric emptying by restoring nitrergic system in diabetic female rats. Therefore, BH4 supplementation is a potential therapeutic option for female

  2. NIDD, a novel DHHC-containing protein, targets neuronal nitric-oxide synthase (nNOS) to the synaptic membrane through a PDZ-dependent interaction and regulates nNOS activity.

    PubMed

    Saitoh, Fuminori; Tian, Qing Bao; Okano, Akira; Sakagami, Hiroyuki; Kondo, Hisatake; Suzuki, Tatsuo

    2004-07-01

    Targeting of neuronal nitric-oxide synthase (nNOS) to appropriate sites in a cell is mediated by interactions with its PDZ domain and plays an important role in specifying the sites of reaction of nitric oxide (NO) in the central nervous system. Here we report the identification and characterization of a novel nNOS-interacting DHHC domain-containing protein with dendritic mRNA (NIDD) (GenBank accession number AB098078), which increases nNOS enzyme activity by targeting the nNOS to the synaptic plasma membrane in a PDZ domain-dependent manner. The deduced NIDD protein consisted of 392 amino acid residues and possessed five transmembrane segments, a zinc finger DHHC domain, and a PDZ-binding motif (-EDIV) at its C-terminal tail. In vitro pull-down assays suggested that the C-terminal tail region of NIDD specifically interacted with the PDZ domain of nNOS. The PDZ dependence was confirmed by an experiment using a deletion mutant, and the interaction was further confirmed by co-sedimentation assays using COS-7 cells transfected with NIDD and nNOS. Both NIDD and nNOS were enriched in synaptosome and synaptic plasma membrane fractions and were present in the lipid raft and postsynaptic density fractions in the rat brain. Co-localization of these proteins was also observed by double staining of the proteins in cultured cortical neurons. Thus, NIDD and nNOS were co-localized in the brain, although the colocalizing regions were restricted, as indicated by the distribution of their mRNA expression. Most important, co-transfection of NIDD and nNOS increased NO-producing nNOS activity. These results suggested that NIDD plays an important role in the regulation of the NO signaling pathway at postsynaptic sites through targeting of nNOS to the postsynaptic membrane. PMID:15105416

  3. 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.

  4. Developing Views of Nature of Science in an Authentic Context: An Explicit Approach to Bridging the Gap between Nature of Science and Scientific Inquiry

    ERIC Educational Resources Information Center

    Schwartz, Renee S.; Lederman, Norman G.; Crawford, Barbara A.

    2004-01-01

    Reform efforts emphasize teaching science to promote contemporary views of the nature of science (NOS) and scientific inquiry. Within the framework of situated cognition, the assertion is that engagement in inquiry activities similar to those of scientists provides a learning context conducive to developing knowledge about the methods and…

  5. An Exploration of Worldview and Conceptions of Nature of Science among Science Teachers at a Private Christian High School

    ERIC Educational Resources Information Center

    Kits, Kara M.

    2011-01-01

    Both worldview and conceptions of nature of science (NOS) are important components in teaching and learning science. However, few empirical studies have examined the interplay between both of these components for teachers or students. Therefore, this study examines the possible relationship between worldview and conceptions of nature of science…

  6. NOS1AP modulates intracellular Ca2+ in cardiac myocytes and is up-regulated in dystrophic cardiomyopathy

    PubMed Central

    Treuer, Adriana V; Gonzalez, Daniel R

    2014-01-01

    NOS1AP gene (nitric oxide synthase 1-adaptor protein) is strongly associated with abnormalities in the QT interval of the electrocardiogram and with sudden cardiac death. To determine the role of NOS1AP in the physiology of the cardiac myocyte, we assessed the impact of silencing NOS1AP, using siRNA, on [Ca2+]i transients in neonatal cardiomyocytes. In addition, we examined the co-localization of NOS1AP with cardiac ion channels, and finally, evaluated the expression of NOS1AP in a mouse model of dystrophic cardiomyopathy. Using siRNA, NOS1AP levels were reduced to ~30% of the control levels (p<0.05). NOS1AP silencing in cardiac myocytes reduced significantly the amplitude of electrically evoked calcium transients (p<0.05) and the degree of S-nitrosylation of the cells (p<0.05). Using confocal microscopy, we evaluated NOS1AP subcellular location and interactions with other proteins by co-localization analysis. NOS1AP showed a high degree of co-localization with the L-type calcium channel and the inwardly rectifying potassium channel Kir3.1, a low degree of co-localization with the ryanodine receptor (RyR2) and alfa-sarcomeric actin and no co-localization with connexin 43, suggesting functionally relevant interactions with the ion channels that regulate the action potential duration. Finally, using immunofluorescence and Western blotting, we observed that in mice with dystrophic cardiomyopathy, NOS1AP was significantly up-regulated (p<0.05). These results suggest for a role of NOS1AP on cardiac arrhythmias, acting on the L-type calcium channel, and potassium channels, probably through S-nitrosylation. PMID:24665357

  7. Anti-Inflammatory Effects of Flavonoids: Genistein, Kaempferol, Quercetin, and Daidzein Inhibit STAT-1 and NF-κB Activations, Whereas Flavone, Isorhamnetin, Naringenin, and Pelargonidin Inhibit only NF-κB Activation along with Their Inhibitory Effect on iNOS Expression and NO Production in Activated Macrophages

    PubMed Central

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

    2007-01-01

    In inflammation, bacterial products and proinflammatory cytokines induce the formation of large amounts of nitric oxide (NO) by inducible nitric oxide synthase (iNOS), and compounds that inhibit NO production have anti-inflammatory effects. In the present study, we systematically investigated the effects of 36 naturally occurring flavonoids and related compounds on NO production in macrophages exposed to an inflammatory stimulus (lipopolysaccharide, LPS), and evaluated the mechanisms of action of the effective compounds. Flavone, the isoflavones daidzein and genistein, the flavonols isorhamnetin, kaempferol and quercetin, the flavanone naringenin, and the anthocyanin pelargonidin inhibited iNOS protein and mRNA expression and also NO production in a dose-dependent manner. All eight active compounds inhibited the activation of nuclear factor-κB (NF-κB), which is a significant transcription factor for iNOS. Genistein, kaempferol, quercetin, and daidzein also inhibited the activation of the signal transducer and activator of transcription 1 (STAT-1), another important transcription factor for iNOS. The present study characterises the effects and mechanisms of naturally occurring phenolic compounds on iNOS expression and NO production in activated macrophages. The results partially explain the pharmacological efficacy of flavonoids as anti-inflammatory compounds. PMID:18274639

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

    ERIC Educational Resources Information Center

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

    2009-01-01

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

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

    PubMed

    Koerber, Susanne; Osterhaus, Christopher; Sodian, Beate

    2015-03-01

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

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

    SciTech Connect

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

    1986-07-01

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

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

    PubMed

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

    2015-01-01

    A series of new (E)-3(5)-[β-(aryl)-ethenyl]-5(3)-phenyl-1H-pyrazoles bearing fluorine atoms at different positions of the aryl group have been synthesized starting from the corresponding β-diketones. All compounds have been characterized by elemental analysis, DSC as well as NMR (¹H, (13)C, (19)F and (15)N) spectroscopy in solution and in solid state. Three structures have been solved by X-ray diffraction analysis, confirming the tautomeric forms detected by solid state NMR. The in vitro study of their inhibitory potency and selectivity on the activity of nNOS and eNOS (calcium-calmodulin dependent) as well as iNOS (calcium-calmodulin independent) isoenzymes is presented. A qualitative structure-activity analysis allowed the establishment of a correlation between the presence/ absence of different substituents with the inhibition data proving that fluorine groups enhance the biological activity. (E)-3(5)-[β-(3-Fluoro-4-hydroxyphenyl)-ethenyl]-5(3)-phenyl-1H-pyrazole (13), is the best inhibitor of iNOS, being also more selective towards the other two isoforms. PMID:26343623

  12. nNOS inhibitors attenuate methamphetamine-induced dopaminergic neurotoxicity but not hyperthermia in mice.

    PubMed

    Itzhak, Y; Martin, J L; Ail, S F

    2000-09-11

    Methamphetamine (METH)-induced dopaminergic neurotoxicity is associated with hyperthermia. We investigated the effect of several neuronal nitric oxide synthase (nNOS) inhibitors on METH-induced hyperthermia and striatal dopaminergic neurotoxicity. Administration of METH (5 mg/kg; q. 3 h x 3) to Swiss Webster mice produced marked hyperthermia and 50-60% depletion of striatal dopaminergic markers 72 h after METH administration. Pretreatment with the nNOS inhibitors S-methylthiocitrulline (SMTC; 10 mg/kg) or 3-bromo-7-nitroindazole (3-Br-7-NI; 20 mg/kg) before each METH injection did not affect the persistent hyperthermia produced by METH, but afforded protection against the depletion of dopaminergic markers. A low dose (25 mg/kg) of the nNOS inhibitor 7-nitroindazole (7-NI) did not affect METH-induced hyperthermia, but a high dose (50 mg/kg) produced significant hypothermia. These findings indicate that low dose of selective nNOS inhibitors protect against METH-induced neurotoxicity with no effect on body temperature and support the hypothesis that nitric oxide (NO) and peroxynitrite have a major role in METH-induced dopaminergic neurotoxicity.

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

    ERIC Educational Resources Information Center

    Axe, Judah B.; Evans, Christine J.

    2012-01-01

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

  14. Nafamostat mesilate promotes endothelium-dependent vasorelaxation via the Akt-eNOS dependent pathway.

    PubMed

    Choi, Sujeong; Kwon, Hyon-Jo; Song, Hee-Jung; Choi, Si Wan; Nagar, Harsha; Piao, Shuyu; Jung, Saet-Byel; Jeon, Byeong Hwa; Kim, Dong Woon; Kim, Cuk-Seong

    2016-09-01

    Nafamostat mesilate (NM), a synthetic serine protease inhibitor, has anticoagulant and anti-inflammatory properties. The intracellular mediator and external anti-inflammatory external signal in the vascular wall have been reported to protect endothelial cells, in part due to nitric oxide (NO) production. This study was designed to examine whether NM exhibit endothelium dependent vascular relaxation through Akt/endothelial nitric oxide synthase (eNOS) activation and generation of NO. NM enhanced Akt/eNOS phosphorylation and NO production in a dose- and time-dependent manner in human umbilical vein endothelial cells (HUVECs) and aorta tissues obtained from rats treated with various concentrations of NM. NM concomitantly decreased arginase activity, which could increase the available arginine substrate for NO production. Moreover, we investigated whether NM increased NO bioavailability and decreased aortic relaxation response to an eNOS inhibitor in the aorta. These results suggest that NM increases NO generation via the Akt/eNOS signaling pathway, leading to endothelium-dependent vascular relaxation. Therefore, the vasorelaxing action of NM may contribute to the regulation of cardiovascular function. PMID:27610041

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

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

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

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

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

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

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

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

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

  18. 75 FR 39707 - Application Nos. and Proposed Exemptions; D-11489, Morgan Stanley & Co., Incorporated; L-11609...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-12

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF LABOR Employee Benefits Security Administration Application Nos. and Proposed Exemptions; D-11489, Morgan Stanley & Co... following corrections: 1. On page 38557, in the third column, insert: ``Morgan Stanley & Co....

  19. ASK1 Inhibitor Halts Progression of Diabetic Nephropathy in Nos3-Deficient Mice.

    PubMed

    Tesch, Greg H; Ma, Frank Y; Han, Yingjie; Liles, John T; Breckenridge, David G; Nikolic-Paterson, David J

    2015-11-01

    p38 mitogen-activated protein kinase (MAPK) signaling promotes diabetic kidney injury. Apoptosis signal-regulating kinase (ASK)1 is one of the upstream kinases in the p38 MAPK-signaling pathway, which is activated by inflammation and oxidative stress, suggesting a possible role for ASK1 in diabetic nephropathy. In this study, we examined whether a selective ASK1 inhibitor can prevent the induction and progression of diabetic nephropathy in mice. Diabetes was induced in hypertensive endothelial nitric oxide synthase (Nos3)-deficient mice by five low-dose streptozotocin (STZ) injections. Groups of diabetic Nos3(-/-) mice received ASK1 inhibitor (GS-444217 delivered in chow) as an early intervention (2-8 weeks after STZ) or late intervention (weeks 8-15 after STZ). Control diabetic and nondiabetic Nos3(-/-) mice received normal chow. Treatment with GS-444217 abrogated p38 MAPK activation in diabetic kidneys but had no effect upon hypertension in Nos3(-/-) mice. Early intervention with GS-444217 significantly inhibited diabetic glomerulosclerosis and reduced renal dysfunction but had no effect on the development of albuminuria. Late intervention with GS-444217 improved renal function and halted the progression of glomerulosclerosis, renal inflammation, and tubular injury despite having no effect on established albuminuria. In conclusion, this study identifies ASK1 as a new therapeutic target in diabetic nephropathy to reduce renal inflammation and fibrosis independent of blood pressure control. PMID:26180085

  20. 13. LONGITUDINAL VIEW OF THE SIX TURBINEGENERATOR UNITS (NO.'S 15 ...

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

    13. LONGITUDINAL VIEW OF THE SIX TURBINE-GENERATOR UNITS (NO.'S 1-5 ARE ORIGINAL). TURBINE-GENERATOR NO.1 IS IN THE FOREGROUND, LOOKING WEST. - Washington Water Power Company Post Falls Power Plant, Middle Channel Powerhouse & Dam, West of intersection of Spokane & Fourth Streets, Post Falls, Kootenai County, ID

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

    PubMed

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

    2016-08-01

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

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

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

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

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

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

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

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

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

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

  5. 49 CFR 173.335 - Chemical under pressure n.o.s.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

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

  6. 49 CFR 173.335 - Chemical under pressure n.o.s.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... internal pressure at 65 °C (149 °F) must not exceed the test pressure of the cylinder. The vapor pressures... 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...

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

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

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

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

    PubMed Central

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

    2016-01-01

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

  9. View from corner of Facility Nos. S358 and S359 (Seaplane ...

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

    View from corner of Facility Nos. S358 and S359 (Seaplane Ramps 2 and 3), looking down Facility No. S359 (Seaplane Ramp 3) towards entrance channel - U.S. Naval Base, Pearl Harbor, Seaplane Runways-1933 Type, South shore of Ford Island, near Lexington Boulevard, Pearl City, Honolulu County, HI

  10. Antioxidative effects of cinnamomi cortex: A potential role of iNOS and COX-II

    PubMed Central

    Chung, Jin-Won; Kim, Jeong-Jun; Kim, Sung-Jin

    2011-01-01

    Background: Cinnamomi cortex has wide varieties of pharmacological actions such as anti-inflammatory action, anti-platelet aggregation, and improving blood circulation. In this study, we tested to determine whether the Cinnamomi cortex extract has antioxidant activities. Materials and Methods: Antioxidative actions were explored by measuring free radical scavenging activity, NO levels, and reducing power. The mechanism of antioxidative action of Cinnamomi cortex was determined by measuring iNOS and COX-II expression in lipopolysaccharide (LPS) stimulated Raw cells. Results: Seventy percent methanolic extract of Cinnamomi cortex exerted significant 1,1-diphenyl--2--picrylhydrazyl (DPPH) free radicals and NO scavenging activities in a dose-dependent manner. More strikingly, the Cinnamomi cortex extract exerted dramatic reducing power activity (13-fold over control). Production of iNOS induced by LPS was significantly inhibited by the Cinnamomi cortex extract, suggesting that it inhibits NO production by suppressing iNOS expression. Additionally, COX-2 induced by LPS was dramatically inhibited by the Cinnamomi cortex extract. Conclusion: These results suggest that 70% methanolic extract of Cinnamomi cortex exerts significant antioxidant activity via inhibiting iNOS and COX-II induction. PMID:22262934

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

    ERIC Educational Resources Information Center

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

    2009-01-01

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

  12. 77 FR 12010 - Marine Mammals; File Nos. 1076-1789 and 14502

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-28

    ... (72 FR 13092), authorized the receipt, import and export of marine mammal specimens (cetaceans and... June 17, 2011 (72 FR 13092), authorized the importation of samples from Risso's (Grampus griseus... National Oceanic and Atmospheric Administration RIN 0648-XB040 Marine Mammals; File Nos. 1076-1789...

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

    PubMed

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

    2015-08-28

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

  14. Nafamostat mesilate promotes endothelium-dependent vasorelaxation via the Akt-eNOS dependent pathway

    PubMed Central

    Choi, Sujeong; Kwon, Hyon-Jo; Song, Hee-Jung; Choi, Si Wan; Nagar, Harsha; Piao, Shuyu; Jung, Saet-byel; Jeon, Byeong Hwa

    2016-01-01

    Nafamostat mesilate (NM), a synthetic serine protease inhibitor, has anticoagulant and anti-inflammatory properties. The intracellular mediator and external anti-inflammatory external signal in the vascular wall have been reported to protect endothelial cells, in part due to nitric oxide (NO) production. This study was designed to examine whether NM exhibit endothelium dependent vascular relaxation through Akt/endothelial nitric oxide synthase (eNOS) activation and generation of NO. NM enhanced Akt/eNOS phosphorylation and NO production in a dose- and time-dependent manner in human umbilical vein endothelial cells (HUVECs) and aorta tissues obtained from rats treated with various concentrations of NM. NM concomitantly decreased arginase activity, which could increase the available arginine substrate for NO production. Moreover, we investigated whether NM increased NO bioavailability and decreased aortic relaxation response to an eNOS inhibitor in the aorta. These results suggest that NM increases NO generation via the Akt/eNOS signaling pathway, leading to endothelium-dependent vascular relaxation. Therefore, the vasorelaxing action of NM may contribute to the regulation of cardiovascular function. PMID:27610041

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

    SciTech Connect

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

    2008-12-01

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

  16. Nafamostat mesilate promotes endothelium-dependent vasorelaxation via the Akt-eNOS dependent pathway

    PubMed Central

    Choi, Sujeong; Kwon, Hyon-Jo; Song, Hee-Jung; Choi, Si Wan; Nagar, Harsha; Piao, Shuyu; Jung, Saet-byel; Jeon, Byeong Hwa

    2016-01-01

    Nafamostat mesilate (NM), a synthetic serine protease inhibitor, has anticoagulant and anti-inflammatory properties. The intracellular mediator and external anti-inflammatory external signal in the vascular wall have been reported to protect endothelial cells, in part due to nitric oxide (NO) production. This study was designed to examine whether NM exhibit endothelium dependent vascular relaxation through Akt/endothelial nitric oxide synthase (eNOS) activation and generation of NO. NM enhanced Akt/eNOS phosphorylation and NO production in a dose- and time-dependent manner in human umbilical vein endothelial cells (HUVECs) and aorta tissues obtained from rats treated with various concentrations of NM. NM concomitantly decreased arginase activity, which could increase the available arginine substrate for NO production. Moreover, we investigated whether NM increased NO bioavailability and decreased aortic relaxation response to an eNOS inhibitor in the aorta. These results suggest that NM increases NO generation via the Akt/eNOS signaling pathway, leading to endothelium-dependent vascular relaxation. Therefore, the vasorelaxing action of NM may contribute to the regulation of cardiovascular function.

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

    NASA Astrophysics Data System (ADS)

    Williams, Cody Tyler; Rudge, David Wÿss

    2016-05-01

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

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

    NASA Astrophysics Data System (ADS)

    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 growth in understanding over time. The Young Children's Views of Science was used to describe how students conversed about NOS among themselves. All science lessons were videotaped, student work collected, and a researcher log was maintained. Data were analyzed by a team of researchers who sorted the students into low-, medium-, and high-achieving levels of NOS understandings based on VNOS-D scores and classwork. Three representative students were selected as case studies to provide an in-depth picture of how instruction worked differentially and how understandings changed for the three levels of students. Three different learning trajectories were developed from the data describing the differences among understandings for the low-, medium-, and high-achieving students. The low-achieving student could discuss NOS ideas, the medium-achieving student discussed and wrote about NOS ideas, the high-achieving student discussed, wrote, and raised questions about NOS ideas.

  19. Upregulated iNOS and oxidative damage to the cochlear stria vascularis due to noise stress.

    PubMed

    Shi, Xiaorui; Nuttall, Alfred L

    2003-03-28

    Our previous work has revealed increased nitric oxide (NO) production in the cochlear perilymph following noise stress. However, it is not clear if the increase of NO is related to iNOS and whether NO-related oxidative stress can cause vascular tissue damage. In this study, iNOS immunoreactivity, NO production, and reactive oxygen species (ROS) in the lateral wall were examined in normal mice and compared with similar animals exposed to 120 dBA broadband noise, 3 h/day, for 2 consecutive days. In the normal animals, iNOS expression was not observed in the vascular endothelium of the stria vascularis and only weak iNOS immunoactivity was detected in the marginal cells. However, expression of iNOS in the wall of the blood vessels of stria vascularis and marginal cells was observed after loud sound stress (LSS). Relatively low levels of NO production and low ROS activity were detected in the stria vascularis in the unstimulated condition. In contrast, NO production was increased and ROS activity was elevated in the stria vascularis after LSS. These changes were attenuated by the iNOS inhibitor, GW 274150. To explore whether noise induces apoptotic processes in the stria vascularis, we examined morphological changes in endothelial- and marginal-cells. In vitro, annexin-V phosphatidylserine (PS) (to label and detect early evidence of apoptosis) was combined with propidium iodide (PI) (to probe plasma membrane integrity). PI alone was used in fixed tissues to detect later stage apoptotic cells by morphology of the nuclei. Following LSS, PS was expressed on cell surfaces of endothelial cells of blood vessels and marginal cells of the stria vascularis. Later stage apoptosis, characterized by irregular nuclei and condensation of nuclei, was also observed in these cells. The data indicate that increased iNOS expression and production of both NO and ROS following noise stress may lead to marginal cell pathology, and the dysfunction of cochlear microcirculation by inducing

  20. Natural Strain

    NASA Technical Reports Server (NTRS)

    Freed, Alan D.

    1997-01-01

    Logarithmic strain is the preferred measure of strain used by materials scientists, who typically refer to it as the "true strain." It was Nadai who gave it the name "natural strain," which seems more appropriate. This strain measure was proposed by Ludwik for the one-dimensional extension of a rod with length l. It was defined via the integral of dl/l to which Ludwik gave the name "effective specific strain." Today, it is after Hencky, who extended Ludwik's measure to three-dimensional analysis by defining logarithmic strains for the three principal directions.

  1. (−)-Epicatechin induces calcium and translocation independent eNOS activation in arterial endothelial cells

    PubMed Central

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

    2011-01-01

    The consumption of cacao-derived (i.e., cocoa) products provides beneficial cardiovascular effects in healthy subjects as well as individuals with endothelial dysfunction such as smokers, diabetics, and postmenopausal women. The vascular actions of cocoa are related to enhanced nitric oxide (NO) production. These actions can be reproduced by the administration of the cacao flavanol (−)-epicatechin (EPI). To further understand the mechanisms behind the vascular action of EPI, we investigated the effects of Ca2+ depletion on endothelial nitric oxide (NO) synthase (eNOS) activation/phosphorylation and translocation. Human coronary artery endothelial cells were treated with EPI or with bradykinin (BK), a well-known Ca2+-dependent eNOS activator. Results demonstrate that both EPI and BK induce increases in intracellular calcium and NO levels. However, under Ca2+-free conditions, EPI (but not BK) is still capable of inducing NO production through eNOS phosphorylation at serine 615, 633, and 1177. Interestingly, EPI-induced translocation of eNOS from the plasmalemma was abolished upon Ca2+ depletion. Thus, under Ca2+-free conditions, EPI can stimulate NO synthesis independent of calmodulin binding to eNOS and of its translocation into the cytoplasm. We also examined the effect of EPI on the NO/cGMP/vasodilator-stimulated phosphoprotein (VASP) pathway activation in isolated Ca2+-deprived canine mesenteric arteries. Results demonstrate that under these conditions, EPI induces the activation of this vasorelaxation-related pathway and that this effect is inhibited by pretreatment with nitro-l-arginine methyl ester, suggesting a functional relevance for this phenomenon. PMID:21209365

  2. Alpha(1)-adrenergic-mediated eNOS phosphorylation in intact arteries.

    PubMed

    Looft-Wilson, Robin C; Todd, Sarah E; Araj, Christina A; Mutchler, Stephanie M; Goodell, Cara A Raphael

    2013-01-01

    Activation of arterial smooth muscle alpha(1)-adrenergic receptors results in vasoconstriction, as well as a secondary release of nitric oxide and slow vasodilation, presumably through gap junction communication from smooth muscle to endothelium. We hypothesized that this slow vasodilation is due to activation of eNOS through phosphorylation at Ser1179 and dephosphorylation at Thr495. Phosphorylation was measured by western blot using mouse mesenteric arteries that were cannulated and pressurized (75 mm Hg) and treated either by 1) 5 min of phenylephrine superfusion (10(-5)M) (PE5), 2) 15 min of phenylephrine (PE15), 3) 15 min phenylephrine followed by acetylcholine (10(-4)M) (PE+ACh), or 4) 20 min time control with no treatment (NT) [4-5 arteries pooled per treatment per blot; 5 blots performed]. These treatments allowed correlation between vasomotor changes, namely maximal constriction (PE5), slow vasodilation (PE15), and maximal dilation (PE+ACh), and relative phosphorylation changes. Phosphorylation of eNOS at Ser1179 was increased relative to NT by more than 2-fold at PE5 and remained similarly increased at PE15 and PE+ACh. Phosphorylation of eNOS at Thr495 was less in all treatments relative to NT, but not significantly. Treatment with L-NAME (10(-4)M) or endothelial denudation indicated that the slow dilation in response to phenylephrine was completely due to nitric oxide synthase and was endothelial dependent. These results indicate that eNOS phosphorylation at Ser1179 occurs before the slow dilation and is not actively involved in this vasodilation or dilation to acetylcholine, but may play a permissive role in eNOS activation by other mechanisms. It is not yet known what mechanism is responsible for Ser1179 phosphorylation with phenylephrine stimulation.

  3. Spinal Neuronal NOS Signaling Contributes to Morphine Cardioprotection in Ischemia Reperfusion Injury in Rats.

    PubMed

    Jiang, Lingling; Hu, Jun; He, Shufang; Zhang, Li; Zhang, Ye

    2016-09-01

    Morphine has been widely used as rescue treatment for heart attack and failure in humans for many decades. Relatively little has been known about the role of spinal opioid receptors in morphine cardioprotection. Recent studies have shown that intrathecal injection of morphine can reduce the heart injury caused by ischemia (I)/reperfusion (R) in rats. However, the molecular and cellular mechanisms underlying intrathecal morphine cardioprotection has not been determined. Here, we report that intrathecal morphine postconditioning (IMPOC) rescued mean artery pressure (MAP) and reduced myocardial injury in I/R. Pretreatment with either naloxone (NAL), a selective mu-opioid receptor antagonist, or nitric oxide synthase (NOS) inhibitors via intrathecal delivery completely abolished IMPOC cardioprotection, suggesting that the spinal mu-opioid receptor and its downstream NOS signaling pathway are involved in the mechanism of the morphine-induced effect. Consistent with this, IMPOC significantly enhanced spinal neural NOS phosphorylation, nitric oxide, and cGMP content in a similar time course. Intrathecal application of 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one, a specific inhibitor of guanylate cyclase, completely ablated IMPOC-induced enhancement of cardioprotection and spinal cGMP content. IMPOC rescue of MAP and ischemic injury is correlated with IMPOC enhancement of NOS signaling. Collectively, these findings strengthen the concept of spinal mu-opioid receptors as a therapeutic target that mediates morphine-induced cardioprotection. We also provide evidence suggesting that the activation of spinal NOS signaling is essential for morphine cardioprotection. PMID:27358482

  4. Ablation of eNOS does not promote adipose tissue inflammation.

    PubMed

    Jurrissen, Thomas J; Sheldon, Ryan D; Gastecki, Michelle L; Woodford, Makenzie L; Zidon, Terese M; Rector, R Scott; Vieira-Potter, Victoria J; Padilla, Jaume

    2016-04-15

    Adipose tissue (AT) inflammation is a hallmark characteristic of obesity and an important determinant of insulin resistance and cardiovascular disease; therefore, a better understanding of factors regulating AT inflammation is critical. It is well established that reduced vascular endothelial nitric oxide (NO) bioavailability promotes arterial inflammation; however, the role of NO in modulating inflammation in AT remains disputed. In the present study, 10-wk-old C57BL6 wild-type and endothelial nitric oxide synthase (eNOS) knockout male mice were randomized to either a control diet (10% kcal from fat) or a Western diet (44.9% kcal from fat, 17% sucrose, and 1% cholesterol) for 18 wk (n= 7 or 8/group). In wild-type mice, Western diet-induced obesity led to increased visceral white AT expression of inflammatory genes (e.g., MCP1, TNF-α, and CCL5 mRNAs) and markers of macrophage infiltration (e.g., CD68, ITGAM, EMR1, CD11C mRNAs, and Mac-2 protein), as well as reduced markers of mitochondrial content (e.g., OXPHOS complex I and IV protein). Unexpectedly, these effects of Western diet on visceral white AT were not accompanied by decreases in eNOS phosphorylation at Ser-1177 or increases in eNOS phosphorylation at Thr-495. Also counter to expectations, eNOS knockout mice, independent of the diet, were leaner and did not exhibit greater white or brown AT inflammation compared with wild-type mice. Collectively, these findings do not support the hypothesis that reduced NO production from eNOS contributes to obesity-related AT inflammation. PMID:26864812

  5. Neuronal NOS and cyclooxygenase-2 contribute to DNA damage in a mouse model of Parkinson disease.

    PubMed

    Hoang, Tuan; Choi, Dong-Kug; Nagai, Makiko; Wu, Du-Chu; Nagata, Tetsuya; Prou, Delphine; Wilson, Glenn L; Vila, Miquel; Jackson-Lewis, Vernice; Dawson, Valina L; Dawson, Ted M; Chesselet, Marie-Françoise; Przedborski, Serge

    2009-10-01

    DNA damage is a proposed pathogenic factor in neurodegenerative disorders such as Parkinson disease. To probe the underpinning mechanism of such neuronal perturbation, we sought to produce an experimental model of DNA damage. We thus first assessed DNA damage by in situ nick translation and emulsion autoradiography in the mouse brain after administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP; 4 x 20 mg/kg, ip, every 2 h), a neurotoxin known to produce a model of Parkinson disease. Here we show that DNA strand breaks occur in vivo in this mouse model of Parkinson disease with kinetics and a topography that parallel the degeneration of substantia nigra neurons, as assessed by FluoroJade labeling. Previously, nitric oxide synthase and cyclooxygenase-2 (Cox-2) were found to modulate MPTP-induced dopaminergic neuronal death. We thus assessed the contribution of these enzymes to DNA damage in mice lacking neuronal nitric oxide synthase (nNOS), inducible nitric oxide synthase (iNOS), or Cox-2. We found that the lack of Cox-2 and nNOS activities but not of iNOS activity attenuated MPTP-related DNA damage. We also found that not only nuclear, but also mitochondrial, DNA is a target for the MPTP insult. These results suggest that the loss of genomic integrity can be triggered by the concerted actions of nNOS and Cox-2 and provide further support to the view that DNA damage may contribute to the neurodegenerative process in Parkinson disease. PMID:19616617

  6. Increased iNOS activity is essential for intestinal epithelial tight junction dysfunction in endotoxemic mice.

    PubMed

    Han, Xiaonan; Fink, Mitchell P; Yang, Runkuan; Delude, Russell L

    2004-03-01

    We tested the hypothesis that increased production of nitric oxide (NO.) associated with lipopolysaccharide (LPS)-induced systemic inflammation leads to functionally significant alterations in the expression and/or targeting of key tight junction (TJ) proteins in ileal and colonic epithelium. Wild-type or inducible NO. synthase (iNOS) knockout male C57B1/6J mice were injected intraperitoneally with 2 mg/kg Escherichia coli O111:B4 LPS. iNOS was inhibited using intraperitoneal L-N(6)-(1-iminoethyl)lysine (L-NIL; 5 mg/kg). Immunoblotting of total protein and NP-40 insoluble proteins revealed decreased expression and decreased TJ localization, respectively, of the TJ proteins, zonula occludens (ZO)-1, ZO-2, ZO-3, and/or occludin in ileal mucosa and colonic mucosa (total protein only) after injection of C57B1/6J mice with LPS. Immunohistochemistry showed deranged distribution of ZO-1 and occludin in both tissues from endotoxemic mice. Endotoxemia was associated with evidence of gut epithelial barrier dysfunction evidenced by increased ileal mucosal permeability to fluorescein isothiocyanate-dextran (Mr=4 kDa) and increased bacterial translocation to mesenteric lymph nodes. Pharmacologic inhibition of iNOS activity using L-NIL or genetic ablation of the iNOS gene ameliorated LPS-induced changes in TJ protein expression and gut mucosal barrier function. These results support the view that at least one mechanism contributing to the pathogenesis of gastrointestinal epithelial dysfunction secondary to systemic inflammation is increased iNOS-dependent NO. production leading to altered expression and localization of key TJ proteins.

  7. eNOS uncoupling in the cerebellum after BBB disruption by exposure to Phoneutria nigriventer spider venom.

    PubMed

    Soares, Edilene Siqueira; Mendonça, Monique Culturato Padilha; da Cruz-Höfling, Maria Alice

    2015-09-15

    Numerous studies have shown that the venom of Phoneutria nigriventer (PNV) armed-spider causes excitotoxic signals and blood-brain barrier breakdown (BBBb) in rats. Nitric oxide (NO) is a signaling molecule which has a role in endothelium homeostasis and vascular health. The present study investigated the relevance of endothelial NO synthase (eNOS) uncoupling to clinical neurotoxic evolution induced by PNV. eNOS immunoblotting of cerebellum lysates processed through low-temperature SDS-PAGE revealed significant increased monomerization of the enzyme at critical periods of severe envenoming (1-2 h), whereas eNOS dimerization reversal paralleled to amelioration of animals condition (5-72 h). Moreover, eNOS uncoupling was accompanied by increased expression in calcium-sensing calmodulin protein and calcium-binding calbindin-D28 protein in cerebellar neurons. It is known that greater eNOS monomers than dimers implies the inability of eNOS to produce NO leading to superoxide production and endothelial/vascular barrier dysfunction. We suggest that transient eNOS deactivation and disturbances in calcium handling reduce NO production and enhance production of free radicals thus contributing to endothelial dysfunction in the cerebellum of envenomed rats. In addition, eNOS uncoupling compromises the enzyme capacity to respond to shear stress contributing to perivascular edema and it is one of the mechanisms involved in the BBBb promoted by PNV.

  8. Human Ischemic Cardiomyopathy Shows Cardiac Nos1 Translocation and its Increased Levels are Related to Left Ventricular Performance

    PubMed Central

    Roselló-Lletí, Esther; Carnicer, Ricardo; Tarazón, Estefanía; Ortega, Ana; Gil-Cayuela, Carolina; Lago, Francisca; González-Juanatey, Jose Ramón; Portolés, Manuel; Rivera, Miguel

    2016-01-01

    The role of nitric oxide synthase 1 (NOS1) as a major modulator of cardiac function has been extensively studied in experimental models; however, its role in human ischemic cardiomyopathy (ICM) has never been analysed. Thus, the objectives of this work are to study NOS1 and NOS-related counterparts involved in regulating physiological function of myocyte, to analyze NOS1 localisation, activity, dimerisation, and its relationship with systolic function in ICM. The study has been carried out on left ventricular tissue obtained from explanted human hearts. Here we demonstrate that the upregulation of cardiac NOS1 is not accompanied by an increase in NOS activity, due in part to the alterations found in molecules involved in the regulation of its activity. We observed partial translocation of NOS1 to the sarcolemma in ischemic hearts, and a direct relationship between its protein levels and systolic ventricular function. Our findings indicate that NOS1 may be significant in the pathophysiology of human ischemic heart disease with a preservative role in maintaining myocardial homeostasis. PMID:27041589

  9. Protection against lipopolysaccharide-induced endothelial dysfunction in resistance and conduit vasculature of iNOS knockout mice.

    PubMed

    Chauhan, S D; Seggara, G; Vo, P A; Macallister, R J; Hobbs, A J; Ahluwalia, A

    2003-04-01

    Endothelial dysfunction is a characteristic of, and may be pathogenic in, inflammatory cardiovascular diseases, including sepsis. The mechanism underlying inflammation-induced endothelial dysfunction may be related to the expression and activity of inducible nitric oxide synthase (iNOS). This possibility was investigated in isolated resistance (mesenteric) and conduit (aorta) arteries taken from lipopolysaccharide (LPS)-treated (12.5 mg/kg i.v.) or saline-treated iNOS knockout (KO) and wild-type (WT) mice. LPS pretreatment (for 15 h, but not 4 h) profoundly suppressed responses to acetylcholine (ACh) and significantly reduced sensitivity to the NO donor spermine-NONOate (SPER-NO) in aorta and mesenteric arteries of WT mice. This effect was temporally associated with iNOS protein expression in both conduit and resistance arteries and with a 10-fold increase in plasma NOx levels. In contrast, no elevation of plasma NOx was observed in LPS-treated iNOS KO animals, and arteries dissected from these animals did not express iNOS or display hyporeactivity to ACh or SPER-NO. The mechanism underlying this phenomenon may be suppression of eNOS expression, as observed in arteries of WT animals, that was absent in arteries of iNOS KO animals. These results clearly demonstrate that iNOS induction plays an integral role in mediation of the endothelial dysfunction associated with sepsis in both resistance and conduit arteries.

  10. 75 FR 58445 - Exelon Generation Company, LLC; Peach Bottom Atomic Power Station Unit Nos. 2 and 3...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-24

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Exelon Generation Company, LLC; Peach Bottom Atomic Power Station Unit Nos. 2 and 3; Environmental... operation of Peach Bottom Atomic Power Station (PBAPS), Unit Nos. 2 and 3, located in York and...

  11. 76 FR 39908 - Calvert Cliffs Nuclear Power Plant, LLC; Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and 2...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-07

    ... COMMISSION Calvert Cliffs Nuclear Power Plant, LLC; Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and 2.... DPR-53 and DPR-69, for the Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and 2 (CCNPP), respectively... (ISFSI), currently held by Calvert Cliffs Nuclear Power Plant, LLC as owner and licensed...

  12. Executive Function in MCDD and PDD-NOS: A Study of Inhibitory Control, Attention Regulation and Behavioral Adaptivity

    ERIC Educational Resources Information Center

    van Rijn, Sophie; de Sonneville, Leo; Lahuis, Bertine; Pieterse, Jolijn; van Engeland, Herman; Swaab, Hanna

    2013-01-01

    A proportion of children within the autism spectrum is at risk for severe deregulation of thought, emotion and behaviour resulting in (symptoms of) psychotic disorders over the course of development. In an attempt to identify this subgroup, children with PDD-NOS, subtype MCDD (n = 24) were compared to children with PDD-NOS (n = 23) on executive…

  13. 75 FR 17159 - Notice of Availability of the Proposed Notice of Sale (NOS) for Outer Continental Shelf (OCS) Oil...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-05

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

  14. Plac8-dependent and iNOS-dependent mechanisms clear Chlamydia muridarum infections from the genital tract1

    PubMed Central

    Johnson, Raymond M.; Kerr, Micah S.; Slaven, James E.

    2011-01-01

    Chlamydia trachomatis urogenital serovars replicate predominately in genital tract epithelium. This tissue tropism poses a unique challenge for host defense and vaccine development. Studies utilizing the Chlamydia muridarum mouse model have shown that CD4 T cells are critical for clearing genital tract infections. In vitro studies have shown that CD4 T cells terminate infection by up regulating epithelial iNOS transcription and nitric oxide production. However, this mechanism is not critical as iNOS-deficient mice clear infections normally. We recently showed that a subset of Chlamydia-specific CD4 T cell clones could terminate replication in epithelial cells using an iNOS-independent mechanism requiring T cell degranulation. We advance that work using microarrays to compare iNOS-dependent and iNOS-independent CD4 T cell clones. Plac8 was differentially expressed by clones having the iNOS-independent mechanism. Plac8-deficient mice had delayed clearance of infection, and Plac8-deficient mice treated with the iNOS-inhibitor N-monomethyl-L-arginine were largely unable to resolve genital tract infections over 8 weeks. These results demonstrate that there are two independent and redundant T cell mechanisms for clearing C. muridarum genital tract infections; one dependent on iNOS, the other dependent on Plac8. While T cells subsets are routinely defined by cytokine profiles, there may be important subdivisions by effector function, in this case CD4Plac8. PMID:22238459

  15. Two Views About Explicitly Teaching Nature of Science

    NASA Astrophysics Data System (ADS)

    Duschl, Richard A.; Grandy, Richard

    2013-09-01

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

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

    NASA Astrophysics Data System (ADS)

    Wallace, Michael L.

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

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

    SciTech Connect

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

    2011-09-01

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

  18. Platelet activating factor (PAF) antagonists on cytokine induction of iNOS and sPLA2 in immortalized astrocytes (DITNC).

    PubMed

    Wang, J H; Sun, G Y

    2000-05-01

    Platelet-activating factor (PAF, 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine) and its receptor are known to play important roles in modulating neuronal plasticity and inflammatory responses, particularly during neuronal injury. PAF receptors are widespread in different brain regions and are present on the cell surface as well as in intracellular membrane compartments. Astrocytes are immune active cells and are responsive to cytokines, which stimulate signaling cascades leading to transcriptional activation of genes and protein synthesis. Our recent studies indicate the ability of cytokines, e.g., tumor necrosis factor-alpha (TNFalpha), interleukin-1beta (IL-1beta) and interferon-gamma (IFNgamma), to induce the inducible nitric oxide (iNOS) and secretory phospholipase A2 (sPLA2) genes in immortalized astrocytes (DITNC) (Li et al., J. Interferon and Cytokine Res. 19: 121-127. 1999). The main objective for this study is to examine the effects of PAF antagonists on cytokine induction of iNOS and sPLA2 in these cells. Results show that BN50730, a synthetic PAF antagonist, but not BN52021, a natural PAF antagonist (ginkolide B) can dose-dependently inhibit cytokine induction of NO production and sPLA2 release. Inhibition of NO production by BN50730 corroborated well with the decrease in iNOS protein and mRNA levels as well as binding of NF-kappaB STAT- 1 to DNA, suggesting that BN50730 action is upstream of the transcriptional process. These results are in agreement with the role of intracellular PAF in regulating the cytokine signaling cascade in astrocytes and further suggest the possible use of BN50730 as a therapeutic agent for suppressing the inflammatory pathways elicited by cytokines. PMID:10905622

  19. D-limonene suppresses doxorubicin-induced oxidative stress and inflammation via repression of COX-2, iNOS, and NFκB in kidneys of Wistar rats.

    PubMed

    Rehman, Muneeb U; Tahir, Mir; Khan, Abdul Quaiyoom; Khan, Rehan; Oday-O-Hamiza; Lateef, Abdul; Hassan, Syed Kazim; Rashid, Sumaya; Ali, Nemat; Zeeshan, Mirza; Sultana, Sarwat

    2014-04-01

    D-limonene is a naturally occurring monoterpene and has been found to posses numerous therapeutic properties. In this study, we used D-limonene as a protective agent against the nephrotoxic effects of anticancer drug doxorubicin (Dox). Rats were given D-limonene at doses of 5% and 10% mixed with diet for 20 consecutive days. Dox was give at the dose of 20 mg/kg body weight intraperitoneally. The protective effects of D-limonene on Dox-induced oxidative stress and inflammation were investigated by assaying oxidative stress biomarkers, lipid peroxidation, serum toxicity markers, proinflammatory cytokines, and expression of nuclear factor kappa B (NFκB), cyclo-oxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS) and Nitrite levels. Administration of Dox (20 mg/kg body weight) in rats enhanced renal lipid peroxidation; depleted glutathione content and anti-oxidant enzymes; elevated levels of kidney toxicity markers viz. kidney injury molecule-1 (KIM-1), blood urea nitrogen (BUN), and creatinine; enhanced expression of NFκB, COX-2, and iNOS and nitric oxide. Treatment with D-limonene prevented oxidative stress by restoring the levels of antioxidant enzymes, further both doses of 5% and 10% showed significant decrease in inflammatory response. Both the doses of D-limonene significantly decreased the levels of kidney toxicity markers KIM-1, BUN, and creatinine. D-limonene also effectively decreased the Dox induced overexpression of NF-κB, COX-2, and iNOS and nitric oxide. Data from the present study indicate the protective role of D-limonene against Dox-induced renal damage.

  20. Tumor necrosis factor-alpha and nerve growth factor synergistically induce iNOS in pheochromocytoma cells.

    PubMed

    Macdonald, N J; Taglialatela, G

    2000-11-01

    Inducible nitric oxide synthase (iNOS) has been reported in tangle-bearing neurons of patients with Alzheimer's disease (AD), and can be induced by tumor necrosis factor-alpha (TNFalpha). High CNS levels of TNFalpha are associated with neurodegenerative diseases such as AD, where neurons dependent on neurotrophins such as nerve growth factor (NGF) are particularly affected. In this study we determined the effect of TNFalpha on iNOS in NGF-responsive pheochromocytoma (PC12) cells. We found that while TNFalpha and NGF alone were unable to induce iNOS, their simultaneous addition resulted in iNOS induction and the release of nitric oxide. Our results suggest that synergistic iNOS induction by TNFalpha and NGF may occur in selective population of NGF-responsive neurons in the presence of elevated CNS levels of TNFalpha.

  1. Expression of the calcium-independent cytokine-inducible (iNOS) isoform of nitric oxide synthase in rat placenta.

    PubMed Central

    Casado, M; D-iaz-Guerra, M J; Rodrigo, J; Fernández, A P; Boscá, L; Martín-Sanz, P

    1997-01-01

    The presence of the calcium-independent cytokine-inducible nitric oxide synthase (iNOS) has been investigated in rat placenta from day 19 of gestation till delivery. iNOS has been detected at the mRNA, enzyme activity and protein levels in complete placenta. Immunocytochemical detection of iNOS was heterogeneously distributed in control placenta. Intraperitoneal injection of pregnant rats at 21 days of gestation with lipopolysaccharide (LPS) increased the iNOS immunoreactivity in the decidua basalis of the placenta, and, when the mRNA levels and enzyme activity were measured in total tissue, a moderate increase (approx. 160%) was observed. A constitutive nuclear factor kappaB activity was observed in placenta from both control and LPS-treated animals. These results indicate constitutive expression of iNOS in rat placenta. PMID:9164857

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

    PubMed

    Peoples, Shelagh M; O'Dwyer, Laura M

    2014-01-01

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

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

    NASA Astrophysics Data System (ADS)

    Peoples, Shelagh

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

  4. Exposure to Diesel Exhaust Up-regulates iNOS Expression in ApoE Knockout Mice

    PubMed Central

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

    2012-01-01

    Traffic related particulate matter air pollution is a risk factor for cardiovascular events; however, the biological mechanisms are unclear. We hypothesize that diesel exhaust (DE) inhalation induces up-regulation of inducible nitric oxide synthase (iNOS), which is known to contribute to vascular dysfunction, progression of atherosclerosis and ultimately cardiovascular morbidity and mortality. Methods ApoE knockout mice (30-week) were exposed to DE (at 200µg/m3 of particulate matter) or filtered-air (control) for 7 weeks (6h/day, 5days/week). iNOS expression in the blood vessels and heart was evaluated by immunohistochemistry and western blotting analysis. To examine iNOS activity, thoracic aortae were mounted in a wire myograph, and vasoconstriction stimulated by phenylephrine (PE) was measured with and without the presence of the specific inhibitor for iNOS (1400W). NF-κB (p65) activity was examined by ELISA. The mRNA expression of iNOS and NF-κB (p65) was determined by real-time PCR. Results DE exposure significantly enhanced iNOS expression in the thoracic aorta (4-fold) and heart (1.5 fold). DE exposure significantly attenuated PE-stimulated vasoconstriction by ~20%, which was partly reversed by 1400W. The mRNA expression of iNOS and NF-κB was significantly augmented after DE exposure. NF-κB activity was enhanced 2-fold after DE inhalation, and the augmented NF-κB activity was positively correlated with iNOS expression (R2= 0.5998). Conclusions We show that exposure to DE increases iNOS expression and activity possibly via NF-κB-mediated pathway. We suspect that DE exposure-caused up-regulation of iNOS contributes to vascular dysfunction and atherogenesis, which could ultimately lead to urban air pollution-associated cardiovascular morbidity and mortality. PMID:21722660

  5. Glutathionylation Mediates Angiotensin II–Induced eNOS Uncoupling, Amplifying NADPH Oxidase‐Dependent Endothelial Dysfunction

    PubMed Central

    Galougahi, Keyvan Karimi; Liu, Chia‐Chi; Gentile, Carmine; Kok, Cindy; Nunez, Andrea; Garcia, Alvaro; Fry, Natasha A. S.; Davies, Michael J.; Hawkins, Clare L.; Rasmussen, Helge H.; Figtree, Gemma A.

    2014-01-01

    Background Glutathionylation of endothelial nitric oxide synthase (eNOS) “uncouples” the enzyme, switching its function from nitric oxide (NO) to O2•− generation. We examined whether this reversible redox modification plays a role in angiotensin II (Ang II)‐induced endothelial dysfunction. Methods and Results Ang II increased eNOS glutathionylation in cultured human umbilical vein endothelial cells (HUVECs), rabbit aorta, and human arteries in vitro. This was associated with decreased NO bioavailability and eNOS activity as well as increased O2•− generation. Ang II‐induced decrease in eNOS activity was mediated by glutathionylation, as shown by restoration of function by glutaredoxin‐1. Moreover, Ang II‐induced increase in O2•− and decrease in NO were abolished in HUVECs transiently transfected, with mutant eNOS rendered resistant to glutathionylation. Ang II effects were nicotinamide adenine dinucleotide phosphate (NADPH) oxidase dependent because preincubation with gp 91ds‐tat, an inhibitor of NADPH oxidase, abolished the increase in eNOS glutathionylation and loss of eNOS activity. Functional significance of glutathionylation in intact vessels was supported by Ang II‐induced impairment of endothelium‐dependent vasorelaxation that was abolished by the disulfide reducing agent, dithiothreitol. Furthermore, attenuation of Ang II signaling in vivo by administration of an angiotensin converting enzyme (ACE) inhibitor reduced eNOS glutathionylation, increased NO, diminished O2•−, improved endothelium‐dependent vasorelaxation and reduced blood pressure. Conclusions Uncoupling of eNOS by glutathionylation is a key mediator of Ang II‐induced endothelial dysfunction, and its reversal is a mechanism for cardiovascular protection by ACE inhibition. We suggest that Ang II‐induced O2•− generation in endothelial cells, although dependent on NADPH oxidase, is amplified by glutathionylation‐dependent eNOS uncoupling. PMID:24755153

  6. Natural inflation

    SciTech Connect

    Frieman, J.A.

    1991-02-01

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

  7. Natural Strain

    NASA Technical Reports Server (NTRS)

    Freed, Alan D.

    1995-01-01

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

  8. [Naturalizing empathy].

    PubMed

    Decety, J

    2002-01-01

    Empathy is the ability to share emotions with others. It is acknowledged to be a powerful means of tacit communication, a key ingredient in any therapeutic relationship as well as in psychotherapy. Empathy is the cornerstone in the humanist perspective (Ego-psychology) in clinical psychology. This approach is often considered as poorly grounded on scientific and objective evidence. It is however acknowledged that empathetic therapists are more effective than less empathetic therapists. I shall argue that this paradox, i.e. it is the least scientific and the less validated psychotherapeutic approach that is the most efficient, can be eliminated if one considers the nature of empathy, its biological foundation, its evolutionary origin and its cognitive architecture. In this paper I will suggest that empathy is based on specific information processing modules which have been designed by natural selection to cope with social regularities in expressing and reading emotional states. This has provided adaptive benefits to individuals living in large groups bestowing them with mechanisms for cooperativity, altruism and more generally various aspects of prosocial behaviour. The capacity to express emotions, and to read and understand emotions of others also ensures implicit communication with others and may be at the root of intersubjectivity. This perspective on empathy is then articulated with two concurrent hypotheses regarding theory of mind (the simulation and the theory-theory) which aim to explain the human capacity to understand that the behaviors of other intelligent agents are caused by intentions, desires and beliefs. In this context, empathy can be considered as a simulation (or analogical) process that is necessary to understand but not sufficient to interpret other people. This last issue is relevant to clinical practice. PMID:11963348

  9. Inhibition of spinal constitutive NOS-2 by 1400W attenuates tissue injury and inflammation-induced hyperalgesia and spinal p38 activation.

    PubMed

    Tang, Qingbo; Svensson, Camilla I; Fitzsimmons, Bethany; Webb, Michael; Yaksh, Tony L; Hua, Xiao-Ying

    2007-05-01

    Nitric oxide (NO) and its synthesizing enzymes, including NO synthase-2 (NOS-2, also called inducible NOS, iNOS), have been implicated in spinal nociception. 1400W is a highly selective NOS-2 inhibitor, as compared with either NOS-1 (neuronal NOS, nNOS) or NOS-3 (endothelial NOS). Here we examined the anti-nociceptive effects of intrathecal (IT) administration of 1400W in two experimental models of hyperalgesia (formalin and carrageenan models), in addition to the effect of 1400W on stimulation-induced activation of spinal p38 mitogen-activated protein kinase (p38). IT treatment of rats with 1400W produced a dose-dependent inhibition of paw formalin-induced phase II flinches, and attenuated carrageenan-induced thermal hyperalgesia. In contrast, IT injection of a selective inhibitor of NOS-1, nNOS inhibitor-I, had no effect in either model. Furthermore, 1400W at a dose that suppressed formalin-induced flinching behavior also blocked formalin-evoked p38 phosphorylation (activation) in the spinal cord, while nNOS inhibitor-I displayed no activity. The prompt effects of IT 1400W suggest involvement of constitutively expressed NOS-2 in spinal nociception. The NOS-2 protein in rat spinal cords was undetectable by Western blotting. However, when the protein was immunoprecipitated prior to Western blotting, NOS-2-immunoreactive bands were detected in the tissues, including naïve spinal cords. The presence of constitutive spinal NOS-2 was further confirmed by reverse transcriptase-polymerase chain reaction. Taken together, the present studies suggest that constitutively expressed spinal NOS-2 mediates tissue injury and inflammation-induced hyperalgesia, and that activation of p38 is one of the downstream factors in NO-mediated signaling in the initial processing of spinal nociception.

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

    PubMed

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

    2015-08-01

    Ginsenoside Rg3, a specific biological effector, is well-known as a major bioactive ingredient of Panax ginseng. However, its role in the inflammasome activation process remains unclear. In this report, we demonstrate that ginsenosides 20(R)-Rg3 and 20(S)-Rg3 are capable of suppressing both lethal endotoxic shock and the S-nitrosylation of the NLRP3 inflammasome by inhibiting nitric oxide (NO) production through the regulation of inducible nitric oxide synthase (iNOS) expression. In response to lipopolysaccharide (LPS), the reducing effect of 20(S)-Rg3 and 20(R)-Rg3 on nitric oxide led to an increase in the survival time of mice after lethal endotoxin-induced shock, and excess levels of NO inhibited IL-1β production via the S-nitrosylation of the NLRP3 inflammasome. In addition, ginsenosides 20(R)-Rg3 and 20(S)-Rg3 had suppressive effects on the LPS- or UV-irradiation-induced reactive oxygen species (ROS) levels in macrophage and HaCaT cells and thereby prevented apoptosis of spleen cells in mice. Altogether, these results demonstrate that ginsenoside 20(R)-Rg3 and 20(S)-Rg3, a naturally occurring compound, might act as a dual therapeutic regulator for the treatment of inflammatory and oxidative stress-related diseases. PMID:26086107

  11. Glutathione S-transferase P1 suppresses iNOS protein stability in RAW264.7 macrophage-like cells after LPS stimulation.

    PubMed

    Cao, Xiang; Kong, Xiuqin; Zhou, Yi; Lan, Lei; Luo, Lan; Yin, Zhimin

    2015-01-01

    Glutathione S-transferase P1 (GSTP1) is a ubiquitous expressed protein which plays an important role in the detoxification and xenobiotics metabolism. Previous studies showed that GSTP1 was upregulated by the LPS stimulation in RAW264.7 macrophage-like cells and GSTP1 overexpression downregulated lipopolysaccharide (LPS) induced inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression. Here we show that GSTP1 physically associates with the oxygenase domain of iNOS by the G-site domain and decreases the protein level of iNOS dimer. Both overexpression and RNA interference (RNAi) experiments indicate that GSTP1 downregulates iNOS protein level and increases S-nitrosylation and ubiquitination of iNOS. The Y7F mutant type of GSTP1 physically associates with iNOS, but shows no effect on iNOS protein content, iNOS S-nitrosylation, and changes in iNOS from dimer to monomer, suggesting the importance of enzyme activity of GSTP1 in regulating iNOS S-nitrosylation and stability. GSTM1, another member of GSTs shows no significant effect on regulation of iNOS. In conclusion, our study reveals the novel role of GSTP1 in regulation of iNOS by affecting S-nitrosylation, dimerization, and stability, which provides a new insight for analyzing the regulation of iNOS and the anti-inflammatory effects of GSTP1. PMID:26361746

  12. History of Science as an Instructional Context: Student Learning in Genetics and Nature of Science

    ERIC Educational Resources Information Center

    Kim, Sun Young; Irving, Karen E.

    2010-01-01

    This study (1) explores the effectiveness of the contextualized history of science on student learning of nature of science (NOS) and genetics content knowledge (GCK), especially interrelationships among various genetics concepts, in high school biology classrooms; (2) provides an exemplar for teachers on how to utilize history of science in…

  13. Cooperative Learning about Nature of Science with a Case from the History of Science

    ERIC Educational Resources Information Center

    Wolfensberger, Balz; Canella, Claudia

    2015-01-01

    This paper reports a predominantly qualitative classroom study on cooperative learning about nature of science (NOS) using a case from the history of science. The purpose of the research was to gain insight into how students worked with the historical case study during cooperative group work, how students and teachers assessed the teaching unit,…

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

    ERIC Educational Resources Information Center

    Paraskevopoulou, Eleni; Koliopoulos, Dimitris

    2011-01-01

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

  15. Tracking the Footprints of Nature of Science in the Path of Learning How to Teach It

    ERIC Educational Resources Information Center

    Bilican, Kader; Ozdem-Yilmaz, Yasemin; Oztekin, Ceren

    2014-01-01

    The present article aimed at understanding those unvoiced biases pre-service teachers may have that conflicts with their integration of nature of science in their science lessons. Three senior pre-service science teachers' views on NOS with regard to their decision making on critical incidents and their reflections about how they…

  16. Learning about the Nature of Science Using Newspaper Articles with Scientific Content

    ERIC Educational Resources Information Center

    García-Carmona, Antonio; Acevedo Díaz, José Antonio

    2016-01-01

    This article presents a study aiming at assessing the efficacy of reading newspaper articles with scientific content in order to incorporate nature of science (NOS) aspects in initial primary teacher education. To this aim, a short teaching intervention based on newspaper articles was planned and performed under regular class conditions. First,…

  17. Relationships among Learner Characteristics and Preservice Elementary Teachers' Views of Nature of Science

    ERIC Educational Resources Information Center

    Akerson, Valarie L.; Donnelly, Lisa A.

    2008-01-01

    The purpose of this study was to explore the relationship of learner characteristics and preservice teachers' views of nature of science (NOS) prior to formal instruction. Learner characteristics investigated included metacognitive awareness, self-efficacy, attitudes toward science teaching, Perry's intellectual and ethical developmental levels,…

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

    ERIC Educational Resources Information Center

    Walls, Leon

    2009-01-01

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

  19. Relationship between Nature of Science Understandings and Argumentation Skills: A Role for Counterargument and Contextual Factors

    ERIC Educational Resources Information Center

    Khishfe, Rola

    2012-01-01

    The study investigated the relationship of high school students' understandings about nature of science (NOS) aspects and their argumentation skills in relation to two controversial socioscientific issues. The study was conducted in five schools selected from different geographical areas in Beirut, Lebanon. Participants were 219 grade 11 students.…

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

    ERIC Educational Resources Information Center

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

    2015-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2013-06-01

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

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

    ERIC Educational Resources Information Center

    Bartos, Stephen A.

    2013-01-01

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

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

    ERIC Educational Resources Information Center

    Khishfe, Rola; Lederman, Norman

    2006-01-01

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

  4. Student Conceptualizations of the Nature of Science in Response to a Socioscientific Issue. Research Report

    ERIC Educational Resources Information Center

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

    2004-01-01

    This study investigates student conceptualizations of the nature of science (NOS) and how students interpret and evaluate conflicting evidence regarding a socioscientific issue. Eighty-four high school students participated in the study by reading contradictory reports about the status of global warming and responding to questions designed to…

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

    ERIC Educational Resources Information Center

    Buaraphan, Khajornsak; Sung-ong, Sunun

    2009-01-01

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

  6. 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…

  7. Comparing Scientists' Views of Nature of Science within and across Disciplines, and Levels of Expertise

    ERIC Educational Resources Information Center

    Tira, Praweena

    2009-01-01

    The purpose of this study was to understand how Thai scientists from four disciplines viewed nature of science (NOS). The sixteen participating scientists were chosen from the areas of chemistry, physics, biology/life sciences, and geology/earth sciences and were separated into novice and expert groups. The scientists' understandings about NOS…

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

    ERIC Educational Resources Information Center

    Vazquez-Alonso, Angel; Garcia-Carmona, Antonio; Manassero-Mas, Maria Antonia; Bennassar-Roig, Antoni

    2013-01-01

    This paper describes Spanish science teachers' thinking about issues concerning the nature of science (NOS) and the relationships connecting science, technology, and society (STS). The sample consisted of 774 in-service and pre-service teachers. The participants responded to a selection of items from the Questionnaire of Opinions on Science,…

  9. The Mismatch among Students' Views about Nature of Science, Acceptance of Evolution, and Evolutionary Science Understandings

    ERIC Educational Resources Information Center

    Cavallo, Ann M. L.; White, Kevin J.; McCall, David

    2011-01-01

    This study explored interrelationships among high school students' views about nature of science (NOS), acceptance of evolution, and conceptual understanding of evolution, and the extent to which these may have shifted from pre- to post-instruction on evolutionary theory. Eighty-one students enrolled in ninth-grade Biology responded to…

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

    ERIC Educational Resources Information Center

    Bartos, Stephen A.; Lederman, Norman G.

    2014-01-01

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

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

    ERIC Educational Resources Information Center

    Abd-El-Khalick, Fouad

    2013-01-01

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

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

    ERIC Educational Resources Information Center

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

    2014-01-01

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

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

    ERIC Educational Resources Information Center

    Tuan, Hsiao-lin; Chin, Chi-Chin

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

  14. Third Grade African American Students' Views of the Nature of Science

    ERIC Educational Resources Information Center

    Walls, Leon

    2012-01-01

    This study examined the nature of science (NOS) views of lower elementary grade level students, including their views of scientists. Participants were 23 third-grade African American students from two Midwest urban settings. A multiple instrument approach using an open-ended questionnaire, semi-structured interviews, a modified version of the…

  15. Beyond Nature of Science: The Case for Reconceptualising "Science" for Science Education

    ERIC Educational Resources Information Center

    Erduran, Sibel

    2014-01-01

    In this paper, I argue that contemporary accounts of nature of science (NoS) are limited in their depiction of "science" and that new perspectives are needed to broaden their characterisation and appeal for science education. In particular, I refer to the role of interdisciplinary characterisations of science in informing the theory and…

  16. The SPRY domain–containing SOCS box protein SPSB2 targets iNOS for proteasomal degradation

    PubMed Central

    Kuang, Zhihe; Lewis, Rowena S.; Curtis, Joan M.; Zhan, Yifan; Saunders, Bernadette M.; Babon, Jeffrey J.; Kolesnik, Tatiana B.; Low, Andrew; Masters, Seth L.; Willson, Tracy A.; Kedzierski, Lukasz; Yao, Shenggen; Handman, Emanuela

    2010-01-01

    Inducible nitric oxide (NO) synthase (iNOS; NOS2) produces NO and related reactive nitrogen species, which are critical effectors of the innate host response and are required for the intracellular killing of pathogens such as Mycobacterium tuberculosis and Leishmania major. We have identified SPRY domain–containing SOCS (suppressor of cytokine signaling) box protein 2 (SPSB2) as a novel negative regulator that recruits an E3 ubiquitin ligase complex to polyubiquitinate iNOS, resulting in its proteasomal degradation. SPSB2 interacts with the N-terminal region of iNOS via a binding interface on SPSB2 that has been mapped by nuclear magnetic resonance spectroscopy and mutational analyses. SPSB2-deficient macrophages showed prolonged iNOS expression, resulting in a corresponding increase in NO production and enhanced killing of L. major parasites. These results lay the foundation for the development of small molecule inhibitors that could disrupt the SPSB–iNOS interaction and thus prolong the intracellular lifetime of iNOS, which may be beneficial in chronic and persistent infections. PMID:20603330

  17. Invariant tori for the Nosé thermostat near the high-temperature limit

    NASA Astrophysics Data System (ADS)

    Butler, Leo T.

    2016-11-01

    Let H(q,p)=\\frac{1}{2}{{p}2}+V(q) be a 1-degree of freedom mechanical Hamiltonian with a C r periodic potential V where r  >  4. The Nosé-thermostated system associated to H is shown to have invariant tori near the infinite temperature limit. This is shown to be true for all thermostats similar to Nosé’s. These results complement the result of Legoll, Luskin and Moeckel who proved the existence of such tori near the decoupling limit (Frederic et al 2007 Arch. Ration. Mech. Anal. 184 449-63, Frederic L et al 2009 Nonlinearity 22 1673-94).

  18. Resveratrol Prevented Lipopolysaccharide-Induced Endothelial Dysfunction in Rat Thoracic Aorta Through Increased eNOS Expression

    PubMed Central

    Uğurel, Seda Sultan; Kuşçu, Nilay; Özenci, Çiler Çelik; Dalaklıoğlu, Selvinaz; Taşatargil, Arda

    2016-01-01

    Background: The cardiovascular benefits of Resveratrol (RVT) have been well established by previous experimental and clinical studies. Aims: The goal of this study was to test the effectiveness of RVT administration on the impaired endothelial function induced by lipopolysaccharide (LPS), and to elucidate the role of endothelial nitric oxide synthase (eNOS)/Sirtuin 1 (SIRT1) pathway. Study Design: Animal experiment. Methods: Endotoxemia was induced by intraperitoneal injection of 10 mg/kg LPS, and the thoracic aorta was isolated six hours later. RVT was injected intraperitoneally 15 minutes before LPS administration. Six hours after LPS injection, potassium chloride (KCl), phenylephrine (Phe), acetylcholine (ACh), and sodium nitroprusside (SNP) were used to examine to vascular reactivity and endothelial function. eNOS, phospho-eNOS (p-eNOS) (Ser 1177), and SIRT1 expressions in thoracic aorta were evaluated by Western blot. Results: LPS administration significantly inhibited the relaxation response induced by ACh, while the relaxation to SNP was not significantly altered. Phe- and KCl-induced contractile responses in the thoracic aorta significantly decreased in LPS-injected group. eNOS and p-eNOS expression decreased significantly in arteries obtained from LPS group rats. The impaired vasoreactivity as well as decreased expressions of eNOS, p-eNOS, and SIRT1 in vessels from LPS-injected rats were improved by RVT treatment. Conclusion: The endothelium-dependent vasodilatation of the thoracic aorta was significantly inhibited by LPS administration, and RVT treatment may improve vascular endothelial function. The protective effect of RVT might be associated with increased eNOS expression and activity. PMID:27403381

  19. NOS1-dependent negative feedback regulation of the epithelial sodium channel in the collecting duct.

    PubMed

    Hyndman, Kelly A; Bugaj, Vladislav; Mironova, Elena; Stockand, James D; Pollock, Jennifer S

    2015-02-01

    With an increase in urine flow there is a significant increase in shear stress against the renal epithelium including the inner medullary collecting duct, resulting in an increase in nitric oxide (NO) production. The mechanisms of the shear stress-mediated increases in NO are undetermined. Previous studies found that shear stress increases epithelial sodium channel (ENaC) open probability and endothelin (ET)-1 production in an ENaC-dependent mechanism in the collecting duct (CD). Given that ET-1 stimulates NO production in the CD, we hypothesized that shear stress-induced NO production is downstream of shear stress-induced ENaC activation and ET-1 production in a negative feedback loop. We determined that nitric oxide synthase 1 (NOS1) and NOS3 contribute to shear stress-mediated NO production in the CD, that is attenuated by low doses of the ENaC inhibitors amiloride and benzamil. Moreover, ETB receptor blockade significantly blunted the shear stress-mediated NO production. We further elucidated whether mice lacking NOS1 in the collecting duct (CDNOS1KO) have an impaired renal ET-1 system in the CD. Although urinary ET-1 production and inner medullary ET receptor expression were similar between flox control and CDNOS1KO mice, acute ET-1 treatment significantly reduced ENaC open probability in CDs from flox mice but not CDNOS1KO mice compared with basal. Basal ENaC activity in CDs was similar between the genotypes. We conclude that during acute shear stress across the CD, ENaC acts in a negative feedback loop to stimulate NO production in an ETB/NOS1-dependent manner resulting in a decrease in ENaC open probability and promoting natriuresis.

  20. Correlation of interactions between NOS3 polymorphisms and oxygen therapy with retinopathy of prematurity susceptibility

    PubMed Central

    Yu, Chunhong; Yi, Jinglin; Yin, Xiaolong; Deng, Yan; Liao, Yujun; Li, Xiaobing

    2015-01-01

    Aim: This study was aimed to detect the correlation of nitric oxide synthase 3 (NOS3) gene polymorphisms (T-786C and G894T) and retinopathy of prematurity (ROP) susceptibility. Interaction between NOS3 gene polymorphisms and the duration of oxygen therapy was also explored in ROP babies. Methods: Genotypes of NOS3 gene polymorphisms were genotyped by MassArray method. Hardy-Weinberg equilibrium (HWE) was used to calculate the representativeness of the cases and controls. Crossover analysis was utilized to explore the gene environment interactions. Relative risk of ROP was presented by odds ratios (ORs) with corresponding 95% confidence intervals (95% CIs). Results: Among the subject features, oxygen therapy had obvious difference between case and control groups (P<0.05). There existed significant association between-786C allele and ROP susceptibility (P=0.049, OR=0.669, 95% CI=0.447-0.999). Genotypes of T-786C polymorphism and genotypes and alleles of G894T polymorphism did not related to the susceptibility of ROP. Interactions were existed between NOS3 gene polymorphisms and oxygen therapy duration. When the duration of oxygen therapy was less than 17 days, both -786CC genotype and 894GT genotype were correlated with ROP susceptibility (P=0.020, OR=0.115, 95% CI=0.014-0.960; P=0.011, OR=0.294, 95% CI=0.100-0.784). Conclusion: -786C allele might have a protective effect for ROP. Interactions of -786CC and 894GT genotype with oxygen therapy duration (less than 17 days) were both protection factors of ROP. PMID:26823875