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1

Co-authoring, Corroborating, Criticizing: Collaborative Storytelling between Virtual and Real Children  

Microsoft Academic Search

When children tell stories with their peers, they naturally collaborate: co-authoring, corroborating, criticizing, in essence, acting as active listeners. And, their reliance on one another, as well as the creative collaboration itself, benefits their literacy development. An interactive system that engages children in collaborative narrative might be able to have a similarly positive effect on children's development. However, due to

Austin Wang; Justine Cassell

2

Co-authoring an Adaptive Educational Hypermedia  

Microsoft Academic Search

Adaptive hypermedia is a relatively new direction of research on the crossroads of hypermedia and user modeling. Until very recently, little attention has been given to the complex task of authoring materials for Adaptive Educational Hypermedia (AEH). An author faces a multitude of problems when creating a personalized, rich learning experience for each user. In this paper, we present an

Said Talhi; Salima Ouadfel; Amel Behaz; Mahieddine Djoudi

2010-01-01

3

Perceptions and Evaluation of Single and Co-authored Publications.  

ERIC Educational Resources Information Center

Business faculty/administrators (n=238) rated single-author publications higher than coauthored ones except for nonrefereed articles. Hypothetical tenure/financial reward decisions generally favored single authors. Of 790 articles in 4 journals, 37% were coauthored. (SK)

Lundgren, Carol A.

1995-01-01

4

Discussion about Possibility of Closer Collaboration or Co-authoring  

SciTech Connect

This slide-show presents the status of a fireside corrosion collaboration, including laboratory fireside tests, callide oxy-fuel field exposures, DTA and TGA of SCM ash, and deposit related bell-shaped boiler corrosion and DTA results.

Holcomb, Gordon R. [NETL; Matsunaga, Y.

2012-12-04

5

To Co-Author or Not to Co-Author: How to Write, Publish, and Negotiate Issues of Authorship with Undergraduate Research Students  

NSDL National Science Digital Library

This Teaching Resource emphasizes the value of publishing with undergraduates and may be particularly helpful to incoming faculty who are new to the process of working with students. Beyond simply extolling the virtues of undergraduate research, we examine how such deep learning experiences for students can translate into unique opportunities for the faculty to demonstrate devotion to both teaching and scholarship. Along with highlighting the reasons faculty should consider publishing with undergraduates, we identify the particular challenges that accompany this suggestion and discuss strategies for overcoming them. Our resource includes two decision trees for helping faculty determine whether publishing with undergraduates represents a reasonable and attainable goal and whether an undergraduate has earned authorship. Based on our experience at primarily undergraduate institutions, we provide a list of strategies that may facilitate writing with undergraduates and lead to certain milestones in the careers of both students and faculty.

Romi L. Burks (Southwestern University;Associate Professor of Biology REV); Matthew M. Chumchal (Texas Christian University;Assistant Professor of Biology REV)

2009-10-27

6

To Co-Author or Not to Co-Author: How to Write, Publish, and Negotiate Issues of Authorship with Undergraduate Research Students  

NSDL National Science Digital Library

Beyond simply extolling the virtues of undergraduate research, we examine how such deep learning experiences for students can translate into unique opportunities for the faculty to demonstrate devotion to both teaching and scholarship. Along with highlighting the reasons faculty should consider publishing with undergraduates, we identify the particular challenges that accompany this suggestion and discuss strategies for overcoming them. Our resource includes two decision trees for helping faculty determine whether publishing with undergraduates represents a reasonable and attainable goal and whether an undergraduate has earned authorship. Based on our experience at primarily undergraduate institutions, we provide a list of strategies that may facilitate writing with undergraduates and lead to certain milestones in the careers of both students and faculty.

Romi Burks (Southwestern University;); Matthew Chumchal (Texas Christian University;)

2009-10-27

7

Co-Authoring Gender-Queer Youth Identities: Discursive Tellings and Retellings  

Microsoft Academic Search

For youth who challenge the culturally fixed gender dichotomy through nonconventional gender expression, societal reaction can be harsh. Uncovering these youth voices as they pioneer new gender frontiers through pathways of language and social dialogue provides the focus for this manuscript. Drawing from discursive, narrative practices, we sat in on a transgender youth conversation group and positioned ourselves as outsider

Susan Saltzburg; Tamara S. Davis

2010-01-01

8

Multiple narratives: How underserved urban girls engage in co-authoring life stories and scientific stories  

NASA Astrophysics Data System (ADS)

Contemporary critics of science education have noted that girls often fail to engage in learning because they cannot "see themselves" in science. Yet theory on identity, engagement, and the appropriation of scientific discourse remains underdeveloped. Using identity as a lens, I constructed 2-two week lunchtime science sessions for 17 ethnic-minority high school girls who were failing their science classes. The units of instruction were informed by a pilot study and based on principles from literature on engagement in identity work and engagement in productive disciplinary discourse. Primary data sources included 19 hours of videotaped lunchtime sessions, 88 hours of audio-taped individual student interviews (over the course of 3--4 years), and 10 hours of audio-taped small group interviews. Secondary data sources included student journals, 48 hours of observations of science classes, teacher surveys about student participation, and academic school records. I used a case-study approach with narrative and discourse analysis. Not only were the girls individually involved in negotiating ideas about their narratives about themselves and their future selves, but collectively some of the girls productively negotiated multiple identities, appropriated scientific and epistemological discourse and learned science content. This was accomplished through the use of a hybrid discourse that blended identity talk with science talk. The use of this talk supported these girls in taking ownership for or becoming advocates for certain scientific ideas.

Thompson, Jessica Jane

9

Co-Authoring Gender-Queer Youth Identities: Discursive "Tellings" and "Retellings"  

ERIC Educational Resources Information Center

|For youth who challenge the culturally fixed gender dichotomy through nonconventional gender expression, societal reaction can be harsh. Uncovering these youth voices as they pioneer new gender frontiers through pathways of language and social dialogue provides the focus for this manuscript. Drawing from discursive, narrative practices, we sat in…

Saltzburg, Susan; Davis, Tamara S.

2010-01-01

10

Using Co-Authoring and Cross-Referencing Information for MEDLINE Indexing  

PubMed Central

Due to the large amount of new papers regularly entering the MEDLINE database, there is an ongoing effort to design tools that help indexing this new material. Here we investigate the hypothesis that past indexing information coming from referencing and authoring links can be used for this purpose. Using a JAMA-based subset of MEDLINE, we designed ranking scores which rely on this information; given a new article, the aim of these scores is to build an ordered list of MeSH terms that should be used to index this article. Evaluation measures on an independent, 1000-document data set are given. Comparison with equivalent works shows benefits in recall, F-measure and mean average precision. Moreover, cited articles and authors’ past articles contribute to seven of the top ten ranking features, supporting our hypothesis. Further improvements and extensions to this work are exposed in the conclusion.

Delbecque, Thierry; Zweigenbaum, Pierre

2010-01-01

11

Seismic Imaging and Inversion: Application of Linear Theory (2012), Cambridge University Press, co-authored with Bob Stolt  

SciTech Connect

Extracting information from seismic data requires knowledge of seismic wave propagation and reflection. The commonly used method involves solving linearly for a reflectivity at every point within the Earth, but this book follows an alternative approach which invokes inverse scattering theory. By developing the theory of seismic imaging from basic principles, the authors relate the different models of seismic propagation, reflection and imaging - thus providing links to reflectivity-based imaging on the one hand and to nonlinear seismic inversion on the other. The comprehensive and physically complete linear imaging foundation developed presents new results at the leading edge of seismic processing for target location and identification. This book serves as a fundamental guide to seismic imaging principles and algorithms and their foundation in inverse scattering theory and is a valuable resource for working geoscientists, scientific programmers and theoretical physicists.

Weglein, Arthur B.; Stolt, Bob H.

2012-03-01

12

The Role of Postgraduate Students in Co-Authoring Open Educational Resources to Promote Social Inclusion: A Case Study at the University of Cape Town  

ERIC Educational Resources Information Center

|Like many universities worldwide, the University of Cape Town (UCT) in South Africa has joined the open educational resources (OER) movement, making a selection of teaching and learning materials available through its OER directory, UCT OpenContent. However, persuading and then supporting busy academics to share their teaching materials as OER…

Hodgkinson-Williams, Cheryl; Paskevicius, Michael

2012-01-01

13

Citation Advantage For OA Self-Archiving Is Independent of Journal Impact Factor, Article Age, and Number of Co-Authors  

Microsoft Academic Search

Eysenbach has suggested that the OA (Green) self-archiving advantage might\\u000ajust be an artifact of potential uncontrolled confounding factors such as\\u000aarticle age (older articles may be both more cited and more likely to be\\u000aself-archived), number of authors (articles with more authors might be more\\u000acited and more self-archived), subject matter (the subjects that are cited\\u000amore, self-archive more),

Chawki Hajjem; Stevan Harnad

2007-01-01

14

Neurolinguistic Papers: Proceedings of the Finnish Conference of Neurolinguistics (2nd, Joensuu, Finland, May 31-June 1, 1985). AFinLA Series No. 40.  

ERIC Educational Resources Information Center

|A collection of papers on neurolinguistics includes: "Communication Strategies in Aphasia" (Elisabeth Ahlsen); "Speech Planning in the Light of Stuttering" (Ann-Marie Alme); "L. S. Tsvetkova's Aphasia Rehabilitation Method and Its Applications" (Ritva Hanninen); "Semantic Aphasia and Luria's Neurolinguistic Model" (Birgitta Johnsen); "Aphasic…

Niemi, Jussi, Ed.; Koivuselka-Sallinen, Paivi, Ed.

16

[On the role of army physicians in the creation of Ukrainian medical terminology].  

PubMed

Tha article is devoted to the analysis of the role army surgeons had in creation of Ukrainean medical terminology. In the article, medical dictionaries are briefly analyzed, of which Ukrainean army surgeons are authors or co-authors. PMID:12442539

Radysh, Ia F; Holyk, L A

17

Mom's Genes May Play Part in How Children Age  

MedlinePLUS

... in Sweden and the Max Planck Institute for Biology of Aging in Germany appears in the Aug. ... principal investigator at the Max Planck Institute for Biology of Aging. Study co-author Dr. Barry Hoffer ...

18

ERRATUM: A theoretical and experimental study of a Ne - H2 Penning recombination laser operating in a hollow cathode discharge  

NASA Astrophysics Data System (ADS)

Dr P Pramatarov and Dr M Stefanova, of the Bulgarian Academy of Sciences, Institute of Solid State Physics, 72 Tzarigradsko Chaussee blvd, 1784 Sofia, Bulgaria, should have been acknowledged as co-authors of the above paper.

Petrov, G. M.

1997-05-01

19

Fossils and human origins, Mark StonekingSite: DNA Interactive (www.dnai.org)  

NSDL National Science Digital Library

Interviewee: Mark Stoneking DNAi Location:Applications>Human origins>migrations Geneticist Mark Stoneking, co-author of an early mitochondrial DNA paper, talks about the competing theories of human origins.

2008-10-06

20

April 12: What is FDA's policy on testing multiple ...  

Center for Drug Evaluation (CDER)

... therapy provides significant therapeutic advantages, there is growing interest in the ... I co-authored a New England Journal of Medicine article titled ... More results from www.fda.gov/drugs/newsevents

21

Scientists Rewrite Germ's Genetic Code  

MedlinePLUS

... this page, please enable JavaScript. Scientists Rewrite Germ's Genetic Code Aim is to redesign natural biological systems for ... researchers say. "This is the first time the genetic code has been fundamentally changed," study co-author Farren ...

22

Nosebleeds Common But Seldom Serious, Study Finds  

MedlinePLUS

... nosebleed patients either by stuffing the nose with cotton or by cauterizing a broken blood vessel using ... who were treated by packing their nose with cotton. Study co-author Dr. Jennifer Villwock said the ...

23

Pictures May Help Encourage Skin Cancer Self-Exams  

MedlinePLUS

... 9 (HealthDay News) -- Pictures can make a strong impression: People who see images of skin cancer are ... detecting melanoma early. Many cases of melanoma are first detected by patients themselves," study co-author Jennifer ...

24

GLEN PAUL FREIBERG, RAC  

Center for Biologics Evaluation and Research (CBER)

Text Version... the first amplified nucleic acid tests for HIV ... BTA stat® bladder cancer monitoring test included an ... Co-Author – FDA Warning Letter Pilot Program (in ... More results from www.fda.gov/downloads/advisorycommittees/committeesmeetingmaterials

25

Taller Women May Face Higher Cancer Odds After Menopause, Study Suggests  

MedlinePLUS

... with increasing height," said study co-author Dr. Thomas Rohan, chairman of the department of epidemiology and ... how and why cancer develops," she said. SOURCES: Thomas Rohan, M.D., Ph.D., chairman and professor ...

26

Depression Research - The STAR*D Study - Relief in Hours?  

MedlinePLUS

... of this page please turn Javascript on. The STAR*D Study New research reveals that, by working ... Southwestern Medical Center and co-authors of the STAR*D study. Photo courtesy of University of Texas ...

27

Studies of Computer Supported Collaborative Writing. Implications for System Design  

Microsoft Academic Search

This paper analyses transformations in collaborative activities that a computer- supported collaborative writing system introduces into co-authors' practices, and, discusses implications for the design of collaborative tools for writing. The analysis is grounded in user studies of four different groups of co-authors writing an academic report during two different collaborative situations. Two groups collaborate face-to-face using a word processor and

Teresa Cerratto; Henrry Rodriguez

2002-01-01

28

Collaborating with writing tools: An instrumental perspective on the problem of computer-supported collaborative activities  

Microsoft Academic Search

This paper presents an analysis of the modifications that a synchronous computer support for collaborative writing introduces into the organization of the co-authors' writing. The analysis is grounded in case studies of different groups of co-authors writing a report together face-to- face and at a distance through a collaborative writing computer system. Drawing from these studies I suggest that the

Teresa Cerratto Pargman

2003-01-01

29

Coauthor pairs' frequencies distribution in journals of gender studies  

Microsoft Academic Search

Previous studies have presented well-ordered collaboration structures of co-author pairs. Kretschmer and Kretschmer have shown that, for high impact SCI journals, the distributions of co-author pairs' frequencies can be considered to be a reflection of a social Gestalt. This study is an extension of that work to the social sciences, namely eleven journals in women's and gender studies. After overlapping

Ramesh Kundra; Hildrun Kretschmer; Theo Kretschmer

30

A Small World of Citations? The Influence of Collaboration Networks on Citation Practices  

PubMed Central

This paper examines the proximity of authors to those they cite using degrees of separation in a co-author network, essentially using collaboration networks to expand on the notion of self-citations. While the proportion of direct self-citations (including co-authors of both citing and cited papers) is relatively constant in time and across specialties in the natural sciences (10% of references) and the social sciences (20%), the same cannot be said for citations to authors who are members of the co-author network. Differences between fields and trends over time lie not only in the degree of co-authorship which defines the large-scale topology of the collaboration network, but also in the referencing practices within a given discipline, computed by defining a propensity to cite at a given distance within the collaboration network. Overall, there is little tendency to cite those nearby in the collaboration network, excluding direct self-citations. These results are interpreted in terms of small-scale structure, field-specific citation practices, and the value of local co-author networks for the production of knowledge and for the accumulation of symbolic capital. Given the various levels of integration between co-authors, our findings shed light on the question of the availability of ‘arm's length’ expert reviewers of grant applications and manuscripts.

Wallace, Matthew L.; Lariviere, Vincent; Gingras, Yves

2012-01-01

31

A small world of citations? The influence of collaboration networks on citation practices.  

PubMed

This paper examines the proximity of authors to those they cite using degrees of separation in a co-author network, essentially using collaboration networks to expand on the notion of self-citations. While the proportion of direct self-citations (including co-authors of both citing and cited papers) is relatively constant in time and across specialties in the natural sciences (10% of references) and the social sciences (20%), the same cannot be said for citations to authors who are members of the co-author network. Differences between fields and trends over time lie not only in the degree of co-authorship which defines the large-scale topology of the collaboration network, but also in the referencing practices within a given discipline, computed by defining a propensity to cite at a given distance within the collaboration network. Overall, there is little tendency to cite those nearby in the collaboration network, excluding direct self-citations. These results are interpreted in terms of small-scale structure, field-specific citation practices, and the value of local co-author networks for the production of knowledge and for the accumulation of symbolic capital. Given the various levels of integration between co-authors, our findings shed light on the question of the availability of 'arm's length' expert reviewers of grant applications and manuscripts. PMID:22413016

Wallace, Matthew L; Larivière, Vincent; Gingras, Yves

2012-03-07

32

Publications of Australian LIS Academics in Databases  

ERIC Educational Resources Information Center

|This paper examines aspects of journal articles published from 1967 to 2008, located in eight databases, and authored or co-authored by academics serving for at least two years in Australian LIS programs from 1959 to 2008. These aspects are: inclusion of publications in databases, publications in journals, authorship characteristics of…

Wilson, Concepcion S.; Boell, Sebastian K.; Kennan, Mary Anne; Willard, Patricia

2011-01-01

33

At the Schoolhouse Gate: Lessons in Intellectual Freedom.  

ERIC Educational Resources Information Center

|Over the last two decades, the co-authors of this book have worked together to build a tradition of intellectual freedom within public schools. The book describes their struggles as cultural workers, the pedagogical and legal strategies they employed, the resistance they encountered, the lessons they learned, and the impact that they have seen on…

Pipkin, Gloria; Lent, ReLeah Cossett

34

Programming Challenges for the Implementation of Numerical Quadrature in Atomic Physics on FPGA and GPU Accelerators  

Microsoft Academic Search

Although the need for heterogeneous chips in high performance numerical computing was identified by Chillemi and co-authors in 2001 it is only over the past five years that it has emerged as the new frontier for HPC. In this environment one or more accelerators works symbiotically, on each node, with a multi-core CPU. Two such accelerator technologies are FPGA and

Charles J. Gillan; T. Steinke; J. Bock; S. Borchert; Ivor T. A. Spence; N. S. Scott

2010-01-01

35

The doubt fighter  

NASA Astrophysics Data System (ADS)

Science historian and 2011 Climate Change Communicator of the Year award-winner Naomi Oreskes talks to Nicola Jones about her latest book Merchants of Doubt (co-authored with Erik Conway), which documents how scientists obscured the truth on global warming.

2011-08-01

36

Situated Consumer Behavior: The Impact of Bodily Influences on Consumer Behavior  

Microsoft Academic Search

Ample scientific evidence points to the fact that people are influenced by contextual factors when making decisions. In the studies presented in this dissertation, I demonstrate how body feedback affects product evaluations and choices, and feelings of power. The underlying assumption is that the environment and bodily states are incorporated in consumer decision making. In the first essay, my co-authors

Jiska Eelen

2011-01-01

37

The National Mapping of Teacher Professional Learning Project: A Multi-Dimensional Space?  

ERIC Educational Resources Information Center

|This essay focuses on the "National Mapping of Teacher Professional Learning" (2008), a report that we co-authored along with a number of other researchers on the basis of extensive surveys and interviews relating to the policies and practices of teacher professional learning in Australia. The report is an update of an earlier survey conducted by…

Doecke, Brenton; Parr, Graham

2011-01-01

38

The Formation and Development of Co-Operations among South African Universities  

ERIC Educational Resources Information Center

Organizational collaboration is "en vogue", especially in higher education. So far, little is known about the mechanisms that explain co-operation formation and their impact on the social structure of the research systems. By examining co-authored research papers written at South African universities between 1966 and 2006, co-operation structures…

Roebken, Heinke

2008-01-01

39

The New Parenatge: Of Families, Sex and Asexual Choices  

Microsoft Academic Search

THE NEW PARENTAGE: OF FAMILIES, SEX AND ASEXUAL CHOICES. A work in progress, by Charles Kindregan, Jr., Distinguished Professor of Law, Suffolk University Law School, Boston. He is the co-author of a book on assisted reproduction (ABA 2006) and the chair of the ABA Committee on Assisted Reproduction and Genetics. Until a generation ago when collaborative reproductive technology came into

Kindregan Charles P. Jr

2006-01-01

40

Intercom, 77. Explorations in the Emergent Present.  

ERIC Educational Resources Information Center

|The issue of Intercom promotes an awareness of the world as a system that poses new possibilities and obligations for educators as well as policy makers. The first part includes interviews with and excerpts from the works of Denis Meadows, joint author of Limits to Growth; Mihajlo Mesarovic, co-author of Mankind at the Turning Point; Robert…

Hanvey, Robert

41

The First-Year Urban High School Teacher: Holding the Torch, Lighting the Fire  

ERIC Educational Resources Information Center

|The book tracks co-author Paul Weinberg during his first year of teaching as he is introduced to the daily tribulations of an urban Los Angeles high school. Paul's father Carl Weinberg, who fifty years earlier himself began his career in education an urban secondary school teacher, shares his experiences side-by-side with those of his son.…

Weinberg, Paul J.; Weinberg, Carl

2008-01-01

42

Don't Close the Golden Door: Our Noisy Debate on Immigration and Its Deathly Silence on Development  

Microsoft Academic Search

Throughout history, international migration has been a central tool in the battle against global poverty and inequality, but the recent heated political debate over immigration reform has largely failed to capture the important ways in which the international movement of people shapes the development process. In this essay, research fellow Michael Clemens and co-author Sami Bazzi outline five major reasons

Michael Clemens; Sami Bazzi

43

Opening Windows  

ERIC Educational Resources Information Center

|Beth Kanter is working hard to get the word out about how best to get the word out. Kanter is CEO of Zoetica, which provides word-of-mouth communication services to nonprofits and socially conscious companies; a decade-long blogger on the topic of social media and nonprofits; and a popular conference speaker and trainer. She is also co-author of…

Bennett, Gayle

2011-01-01

44

The Interaction and M ¤ obius Representations of Fuzzy Measures on Finite Spaces, Additive Measures: A Survey  

Microsoft Academic Search

This paper presents a synthesis of results on the concept of -additive measures and the notion of representation of a fuzzy measure, since their introduction by the author in 1996. The collection of results will limit itself to results which are not connected with multicriteria deci- sion making, since those are presented in a companion paper in this book, co-authored

Michel GRABISCH

45

What does international co-authorship measure?  

Microsoft Academic Search

We argue that while researchers note that co­ authorship is an insufficient metric for international research collaboration there is little understanding about what else international co-authorship represents. Rather than focus on co­ authorship solely as an output of research, we focus on the interaction between researchers involved in a co-authored paper. We therefore interview a range of researchers who had

Dhanaraj Thakur; Jian Wang; Susan Cozzens

2011-01-01

46

Research Ideas for the Classroom: High School Mathematics.  

ERIC Educational Resources Information Center

|Research Ideas for the Classroom is a three-volume series of research interpretations for early childhood, middle grades, and high school mathematics classrooms. Each volume looks at research from the perspective of the learner, the content, and the teacher, and chapters are co-authored by a researcher and a teacher. Chapter titles in the high…

Wilson, Patricia S., Ed.

47

Children's Services: Partnerships for Success  

ERIC Educational Resources Information Center

|Co-author of the popular titles "Booktalking Bonanza" and "The Early Literacy Kit", Betsy Diamant-Cohen brings together 18 examples of successful outreach partnerships that children's librarians and administrators can adapt to their own situations. Contributors from the U.S and Canada explain how they partnered with schools, community…

Diamant-Cohen, Betsy, Ed.

2010-01-01

48

What might the Soviet Union learn from the OECD countries in economics and politics ? An article from 1991 with some comments from 2005  

Microsoft Academic Search

When cleaning up my archives I came across a short article of April 1991 co-authored with Jan Tinbergen, on what the Soviet Union might learn from OECD countries in economics and politics. The article apparently never got published, partly since the Soviet Union collapsed in December 1991. Jan Tinbergen died in 1994. Reading the article again in 2005 shows that

Thomas Cool; Jan Tinbergen; Thomas Colignatus

2005-01-01

49

The First-Year Urban High School Teacher: Holding the Torch, Lighting the Fire  

ERIC Educational Resources Information Center

The book tracks co-author Paul Weinberg during his first year of teaching as he is introduced to the daily tribulations of an urban Los Angeles high school. Paul's father Carl Weinberg, who fifty years earlier himself began his career in education an urban secondary school teacher, shares his experiences side-by-side with those of his son.…

Weinberg, Paul J.; Weinberg, Carl

2008-01-01

50

Nuclear Fusion Award 2009 speech Nuclear Fusion Award 2009 speech  

Microsoft Academic Search

This is an exceptional moment in my career, and so I want to thank all of my teachers, colleagues and mentors who have made this possible. From my co-authors and myself, many thanks to the International Atomic Energy Agency, IOP Publishing, the Nuclear Fusion journal team, and the selection committee for the great honor of receiving this award. Also gratitude

Steven Anthony Sabbagh

2011-01-01

51

Exercise Physiology and the Academy: Contributions to Physiological Concepts and Biological Systems during the Commemorative Years  

ERIC Educational Resources Information Center

|To determine the contributions made by Academy Fellows during the past 75 years to concepts within the body of knowledge associated with exercise physiology, a literature search was undertaken. Of the charter Fellows, Hetherington and eight others (34%) were identified. Schneider in 1933 was the first of 18 Fellows who became authors, co-authors,…

Tipton, Charles M.

2006-01-01

52

The Future of the American Faculty: An Interview with Martin J. Finkelstein and Jack H. Schuster  

ERIC Educational Resources Information Center

|Martin J. Finkelstein and Jack H. Schuster have teamed up to continue tracing the changes taking place in faculty work with their Project on the American Faculty. They have published The New Academic Generation: A Profession in Transformation (1998), co-authored with Robert Seal, and are preparing a new manuscript to appear in 2004 with a working…

Rice, R. Eugene

2004-01-01

53

Keeping Students and Schools Safe  

ERIC Educational Resources Information Center

This article is based on an interview with a noted expert on school violence who recently co-authored the book Targeting Innocence--When Terrorism Comes to School. Central to school safety are supportive bonds with adults who help create school climates free of bullying. The expert interviewed is Michael Dorn. He recommends that in regard to…

Dufresne, Jerilyn

2005-01-01

54

Spiritually Sensitive Social Work: An Overview of American and International Trends Plenary Address for International Conference on Social Work and Counseling  

Microsoft Academic Search

Acknowledgment: The author thanks Oxford University Press for permission to excerpt and adapt portions of the book, Spiritual Diversity in Social Work: The Heart of Helping, second edition (2009). The author also thanks Dr. Leola Dyrud Furman, co-author of the book, especially for her leadership in the surveys mentioned in this article. Abstract This article presents an overview of the

Edward R. Canda

55

Using Rituals and Traditions to Create Classroom Community for Children, Teachers, and Parents  

ERIC Educational Resources Information Center

|This article addresses the value of teachers establishing rituals and traditions in early childhood classrooms. Using the lens of a particular preschool classroom, where one of the co-authors taught for many years, the article describes specific traditions that have been established over the years and how these rituals, activities, and events…

Scully, Patricia; Howell, Jacqueline

2008-01-01

56

Analysis of electromagnetic problems involving chiral, bi-isotropic, and uniaxial bianisotropic media  

NASA Astrophysics Data System (ADS)

The following topics are included: introduction to the subject; constitutive relations; electromagnetic fields; bi-isotropic waveguides; uniaxial bianisotropic medium; image methods; and a summary of 8 papers in which the author of this thesis (P. Koivisto) was the author, or a co-author.

Koivisto, Paeivi K.

1994-11-01

57

International Standards for College and University Technology Units: How Effective Could They Be?  

Microsoft Academic Search

In the summer of 1989, AECT (the Association for Educational Communications and Technology) published the second edition of a document which provides American colleges and universities with definitive standards to be applied to their learning resources programmes and centres. The author, who is also one of the co?authors of the document, raises the question of applicability of the standards to

Richard Cornell

1991-01-01

58

Activating Space: piloting cross-disciplinary learning within a higher-education institution  

Microsoft Academic Search

University College Falmouth (UCF) UK is a specialist Higher Education Institution (HEI) with 2800 students within the Schools of Art and Performance, Media and Design. The School of Design has been piloting projects which draw on the co-authors recent experience of implementing a collaborative learning experience that explores the distinctions between multidisciplinary, interdisciplinary and transdisciplinary learning. Recent British perspectives in

Simon Thompson; Jean Whitehead

59

Money and Schools. Fourth Edition  

ERIC Educational Resources Information Center

|For future principals and others enrolled in courses on School Finance, this book explains and demonstrates the relationship between money and student achievement. New to this edition: (1) Includes updated information on the ever-changing landscape of school finance; (2) Co-author Faith E. Crampton has joined the author team, applying the…

Thompson, David C.; Wood, R. Craig; Crampton, Faith E.

2008-01-01

60

Global sourcing trends in 2008  

Microsoft Academic Search

Purpose – The purpose of this paper is to collate Morrison & Foerster's view on the state of the global outsourcing market and their lawyers' experience with a wide range of sourcing projects in a number of geographic and sectoral markets. Design\\/methodology\\/approach – The global sourcing trends 2008 report is co-authored by Morrison & Foerster partners based in Europe, the

Jon Edgell; Gabriel E. Meister; Nigel Stamp

2008-01-01

61

Wave collapse in plasmas and fluids  

Microsoft Academic Search

This lecture is a review of recent results (obtained mainly by the author and his co-authors) in the wave collapse theory with applications to plasma physics, fluid dynamics and nonlinear optics as well. The main attention in the review is paid to the qualitative reasons of the wave collapse and to the exact methods based on the integral estimations. Both

E. A. Kuznetsov

1996-01-01

62

Wave collapse in plasmas and fluids  

Microsoft Academic Search

This lecture is a review of recent results ~obtained mainly by the author and his co-authors! in the wave collapse theory with applications to plasma physics, fluid dynamics and nonlinear optics as well. The main attention in the review is paid to the qualitative reasons of the wave collapse and to the exact methods based on the integral estimations. Both

E. A. Kuznetsov

63

Seeing Organizational Learning: A 'Cultural' View  

Microsoft Academic Search

What sight does a 'cultural' approach to organizational learn- ing enable? In an earlier essay my co-author and I argued that such an approach made it possible to bypass certain conceptual problems inher- ent in treating organizational learning as an attribute of individuals. In this essay I reflect on the metaphoric process that enabled that argument, which was implicitly as

Dvora Yanow

64

Recent developments in China's export controls: New regulations and new challenges  

Microsoft Academic Search

Dr. Jing-dong Yuan is a Senior Research Associate in the East Asia Nonproliferation Program (EANP) at the Center for Nonproliferation Studies of the Monterey Institute of International Studies. He is co-author of the forthcoming study, China- India Relations: Cooperation or Conflict? (Lynne Rienner, 2003). Dr. Phillip C. Saunders is Director of EANP. He has worked on Asian security issues for

Phillip C. Saunders; Stephanie Lieggi

2002-01-01

65

Comments to the article by Verner et al.: Magmatic history and geophysical signature of a post-collisional intrusive center  

NASA Astrophysics Data System (ADS)

Verner and co-authors (Int J Earth Sci (2009) 98:517-532) published geological and structural model of evolution and emplacement of the Plöckenstein pluton in the border area of Austria, Germany and Czech Republic. They used data of other authors, giving no reference as to their source, for interpretations without any discussion of the already published results.

Breiter, Karel

2011-06-01

66

Return of the Google Game: More Fun Ideas to Transform Students into Skilled Researchers  

ERIC Educational Resources Information Center

|Teens are impatient and unsophisticated online researchers who are often limited by their poor reading skills. Because they are attracted to clean and simple Web interfaces, they often turn to Google--and now Wikipedia--to help meet their research needs. The Google Game, co-authored by this author, teaches kids that there is a well-thought-out…

Watkins, Katrine

2008-01-01

67

Identity Matters in a Short-Term, International Service-Learning Program  

ERIC Educational Resources Information Center

|This study explores the role that identity and the identity development process play in a short-term, international service-learning experience. Employing narrative inquiry, two of the co-authors, student participants in a 2-week service-learning program in Honduras, describe and interpret their service-learning experience in the context of life…

Mather, Peter C.; Karbley, Megan; Yamamoto, Makiko

2012-01-01

68

WORLD-WIDE DIRECT USES OF GEOTHERMAL ENERGY 2000  

Microsoft Academic Search

The worldwide application of geothermal energy for direct utilization is reviewed. This paper attempts to update the previous survey carried out in 1995 by one of the co-authors (Freeston) and presented at the World Geothermal Congress in Florence, Italy. For each of these updates since 1975, the recording of data has been similar, but not exactly the same. As in

John W. Lund; Derek H. Freeston

2000-01-01

69

Leaders in American Medicine - Paul B Beeson, MD, and Eugene A Stead, Jr, MD.  

National Technical Information Service (NTIS)

Doctors stead and beeson began their joint work at grady hospital in atlanta. Beeson used penicillin to prevent fatal diseases. Later, studying shock and heart failure, stead co-authored a paper of lasting significance in this field. Each doctor discusses...

1994-01-01

70

Leaders in American Medicine - Paul B Beeson, MD, and Eugene A Stead, Jr, MD.  

National Technical Information Service (NTIS)

Doctors Stead and Beeson began their joint work at Grady Hospital in Atlanta. Beeson used pencillin to prevent fatal diseases. Later, studying shock and heart failure, Stead co-authored a paper of lasting significance in this field. Each doctor discusses ...

1994-01-01

71

Advance Acclaim for The Thought That Counts  

Microsoft Academic Search

''What a remarkable book! Jared Kant and his co-authors have produced a re- vealing, first-hand look at OCD that manages to be brutally honest, yet at the same time tremendously supportive and reassuring. I admire Jared's bravery and his willingness to let the world see his descent into this terrible illness as well as his eventual recovery. Young people with

David F. Tolin

72

Children's Services: Partnerships for Success  

ERIC Educational Resources Information Center

Co-author of the popular titles "Booktalking Bonanza" and "The Early Literacy Kit", Betsy Diamant-Cohen brings together 18 examples of successful outreach partnerships that children's librarians and administrators can adapt to their own situations. Contributors from the U.S and Canada explain how they partnered with schools, community…

Diamant-Cohen, Betsy, Ed.

2010-01-01

73

The Freakonomics of Tenure  

ERIC Educational Resources Information Center

|The ever-simmering question of whether the tenure system should be reformed lit up the blogosphere, ignited by an online essay from the (tenured) professor Steven D. Levitt, co-author of the publishing phenomenon "Freakonomics: A Rogue Economist Explores the Hidden Side of Everything" and the popular blog Freakonomics. When Levitt posted "Let's…

Chronicle of Higher Education, 2007

2007-01-01

74

From Collaboration to Publication  

ERIC Educational Resources Information Center

As co-authors of a recent publication in "Physical Review Special Topics-Physics Education Research", we have received inquiries about the publication process. We will describe the process of creating an article based on team work, in our case the work of the Texas Physics Assessment Team. Many physics teachers have opportunities to participate in…

O'Connor, Jerry; Marshall, Jill

2010-01-01

75

A Dialogue on Reclaiming Troubled Youth  

ERIC Educational Resources Information Center

|This discussion is drawn from the writings of two eminent founders of strength-based approaches to troubled children and adolescents. August Aichhorn is best known for his classic book, "Wayward Youth," and Fritz Redl as co-author of "Children Who Hate". August Aichhorn and Anna Freud mentored a young educational psychologist, Fritz Redl…

Aichhorn, August; Redl, Fritz

2012-01-01

76

External Resource: Real time Geochron  

NSDL National Science Digital Library

This site is developed and maintained by John Walker, founder of Autodesk, Inc. and co-author of AutoCAD. A variety of documents, images, software for various machines, and interactive Web resources are available here. Specifically, for this interactive r

1900-01-01

77

Co-authorship in the academic library literature: A survey of attitudes and behaviors  

Microsoft Academic Search

A survey of co-authors in the literature of academic librarianship was conducted to get a better understanding of how and why these authors work together. Findings examine the benefits of collaboration, working relationships, the division of labor, and name order assignment on the article.

Richard L Hart

2000-01-01

78

A Social Studies Teacher's Sense Making of Controversial Issues Discussions of Race in a Predominantly White, Rural High School Classroom  

ERIC Educational Resources Information Center

In this qualitative study, the authors first explore the "sense making" of Emma, a former high school teacher (and co-author of this study), with regard to discussion of issues around race that became controversial in her social studies classroom. Her student population comprised predominantly white, rural, socioeconomically disadvantaged…

Washington, Elizabeth Yeager; Humphries, Emma K.

2011-01-01

79

A Dialogue on Reclaiming Troubled Youth  

ERIC Educational Resources Information Center

This discussion is drawn from the writings of two eminent founders of strength-based approaches to troubled children and adolescents. August Aichhorn is best known for his classic book, "Wayward Youth," and Fritz Redl as co-author of "Children Who Hate". August Aichhorn and Anna Freud mentored a young educational psychologist, Fritz Redl…

Aichhorn, August; Redl, Fritz

2012-01-01

80

How to kill a mandate. Hospital lobby persuades Scully, CMS to scuttle proposal that would have required hospitals to measure patient satisfaction.  

PubMed

The Centers for Medicare and Medicaid Services has backed off its plan to require all Medicare-certified hospitals to publicly report mandatory patient surveys, Modern Healthcare has learned. Instead, no regulations will be written and hospitals will be asked to voluntarily use surveys. American Hospital Association President Richard Davidson, left, co-authored a letter urging hospitals to participate. PMID:12884717

Tieman, Jeff

2003-07-01

81

Working on Mincemeat  

Microsoft Academic Search

Farhana Sheikh is co?author of Mincemeat, a play about a World War Two intelligence operation, and its connection to the world of the homeless. In this article, she reflects on some themes of the play, in the context of the continuing British preoccupation with the war, and discusses the play’s attempt to represent the upper echelons of society and its

Farhana Sheikh

2010-01-01

82

Unleashing Deep Smarts: The Most Valuable Untapped Source of Knowledge Lies within the District's Own Personnel  

ERIC Educational Resources Information Center

|A widely applied premise in the field of business asserts that the key to an organization's success in today's changing environment is a world-class knowledge management system. The most critical value-added piece of this puzzle lies in what co-authors Dorothy Leonard and Walter Swap in their book Deep Smarts: How to Cultivate and Transfer…

Burbach, Harold J.; Butler, Alfred R., IV

2005-01-01

83

The Quagmire Called Lebanon  

Microsoft Academic Search

Dr. David Kimche is the president of the Israel Council on Foreign Relations and served as the director general of the Israeli Ministry of Foreign Affairs from 1980-1987. He is the author and co-author of a number of books on Israel and international affairs, including The Last Option: After Nasser, Arafat & Saddam Hussein. Of all the countries in the

David Kimche

84

Reflection on the Role of Artists: A Case Study on the Hidden Visual Curriculum of the School of the Art Institute of Chicago  

ERIC Educational Resources Information Center

In 2005, Maria Acaso, professor in Art Education at the Universidad Complutense Madrid in Spain and a co-author of this article, conducted a comparative research project on visual configurations at different art schools in Europe and the United States. The study of hidden visual curriculum examines how knowledge and cultural/political/social…

Baker, Marissa H.; Ng-He, Carol; Lopez-Bosch, Maria Acaso

2008-01-01

85

COEO's Landmark Research Summary: "Reconnecting Children through Outdoor Education"  

ERIC Educational Resources Information Center

Over the past year, Andrea Foster reviewed a wide array of current and international research into the multiple, powerful and lasting outcomes produced through utilizing outdoor and experiential education (OEE) as a key learning methodology. As co-authors, Foster and Linney produced an 80-page document that reports the findings according to the…

Linney, Grant

2007-01-01

86

Epilogue: the struggles must continue  

Microsoft Academic Search

In the epilogue to this special issue, the co-author reflects upon recent efforts to bring about social change in and through sport, the contributions of scholarship to those efforts and the current terrain. He argues that while sport has power to effect progressive change, we should not exaggerate the extent of that power. Moreover, sport activists rarely make effective coalitions

Bruce Kidd

2010-01-01

87

Collaborative Learning: Cognitive and Computational Approaches. Advances in Learning and Instruction Series.  

ERIC Educational Resources Information Center

|Intended to illustrate the benefits of collaboration between scientists from psychology and computer science, namely machine learning, this book contains the following chapters, most of which are co-authored by scholars from both sides: (1) "Introduction: What Do You Mean by 'Collaborative Learning'?" (Pierre Dillenbourg); (2) "Learning Together:…

Dillenbourg, Pierre, Ed.

88

Lipid Analysis: Isolation, separation, identification and lipidomic analysis - Fourth Edition  

Technology Transfer Automated Retrieval System (TEKTRAN)

Review of book, Lipid Analysis, Isolation, separation, identification and lipidomic analysis - Fourth Edition, by W.W. Chrisitie and X. Han, 2010. William W. Christie is considered by many to be the most prominent international authority on lipid analysis. The co-author, Dr. Xianlin Han, is a pion...

89

Molecular theory of homogeneous nucleation using a more sophisticated kinetic  

NASA Astrophysics Data System (ADS)

We use a recent non ad hoc model of microcluster (MM) proposed by Prof. Howard Reiss and co-authors [1,2] together with a more rigorous theory of the nucleation kinetic equation. It is shown that this model satisfactory predicts at least qualitative features of nucleation and the nucleation rate is insensitive to the connectivity distance dc. .

Itkin, Andrey L.

2000-08-01

90

Advances in Thermal Infrared Remote Sensing for Land Surface Modeling  

Technology Transfer Automated Retrieval System (TEKTRAN)

Over 10 years ago, John Norman and co-authors proposed a thermal-based land surface modeling strategy that treated the energy exchange and kinetic temperatures of the soil and vegetated components in a unique “Two-Source Model” (TSM) approach. The TSM formulation addresses key factors affecting the...

91

Producing a Documentary in the Third Grade: Reaching All Students through Movie Making  

ERIC Educational Resources Information Center

This article details the work of third grade teacher, co-author Kim Heckart, as she engaged her students in making historical documentaries: a project that succeeded in reaching all of her third-grade students. For the last five years, Kim has required students to make historical documentaries. As her students produced these works, Kim conversed…

Fehn, Bruce; Heckart, Kimberly

2013-01-01

92

Exploring the Educational Experience of a Social Work Student with a Disability: A Narrative  

Microsoft Academic Search

This article describes the experience of Lisa, one of the co-authors, as a student with a disability completing a Bachelor of Social Work degree in Western Canada. This personal narrative of the physical, relational, attitudinal, curricular and resource aspects of Lisa's education identifies barriers experienced in the educational and practice environments, and highlights strategies that assisted in addressing these barriers.

Lisa Coriale; Grant Larson; Jeanette Robertson

2011-01-01

93

Exploring the Educational Experience of a Social Work Student with a Disability: A Narrative  

Microsoft Academic Search

This article describes the experience of Lisa, one of the co-authors, as a student with a disability completing a Bachelor of Social Work degree in Western Canada. This personal narrative of the physical, relational, attitudinal, curricular and resource aspects of Lisa's education identifies barriers experienced in the educational and practice environments, and highlights strategies that assisted in addressing these barriers.

Lisa Coriale; Grant Larson; Jeanette Robertson

2012-01-01

94

ISS Update: Nutrition Manager Talks About Children's Book “Space Nutrition”  

NASA Video Gallery

NASA Public Affairs Officer Brandi Dean interviews Scott Smith, Manager of Nutritional Biochemistry at Johnson Space Center, about the children’s book he co-authored called “Space Nutrition.” The book talks about the history of space flight, the various space programs and of course space food.

Mark Garcia

2012-12-14

95

USGS Oceanographer Named to IPCC Report  

USGS Multimedia Gallery

Asbury (Abby) H. Sallenger has been named one of the authors of a chapter in the next IPCC report, due to be published in 2014. Sallenger has been assigned to co-author Chapter 5 of the Fifth Assessment Report, entitled Coastal Systems and Low-Lying Areas. This chapter will contain an international ...

2010-06-23

96

NASA Now Minute: Earth and Space Science: 100 Billion Planets  

NASA Video Gallery

Stephen Kane, co-author of the article, “Study Shows Our Galaxy has 100 Billion Planets” reveals details about this incredible study explains just how common planets are in our Milky Way galaxy. NASA Now Minutes are excerpts from a weekly current events program available for classroom use at the NASA Explorer Schools Virtual Campus located at: › http://explorerschools.nasa.gov.

Heather Deiss

2012-02-10

97

Shakespeare in Japan: A Multimedia Teaching Resource.  

ERIC Educational Resources Information Center

|Describes a CD ROM created by three co-authors which presents a multimedia exposition and comparison of three parallel productions of Shakespeare's "A Midsummer Night's Dream" by a single director staged sequentially at the Tokyo Globe in 1994. Provides specific suggestions as to how secondary English teachers could use this material. (NH)|

Gillies, John

1999-01-01

98

Pragmatic uses of metaphor: Models and metaphor in the nuclear winter scenario  

Microsoft Academic Search

The scientific work of Carl Sagan and his co?authors has been instrumental in bringing before the public the potentially catastrophic effects of even a limited nuclear war. Sagan has presented these findings in scientific discourse centered in the pragmatic use of a novel metaphor. This article examines and describes the pragmatic uses of the “nuclear winter” metaphor in two separate

William A. Ausmus

1998-01-01

99

What's in a name? Ask yahoo!  

Microsoft Academic Search

A company's brand is one of its most valuable assets, one that few high tech companies -- most recently HP and Compaq -- understand how to leverage, according to Sam Hill. Hill is co-author (with Chris Lederer) of the new book, The Infinite Asset: Managing Brands to Build New Value. He is the former chief marketing officer at Booz Allen

2001-01-01

100

Using GIS to Answer the "Whys" of "Where" in Social Studies  

ERIC Educational Resources Information Center

In this article, the authors build upon the use of GIS (Geographic Information Systems) in U.S. history and in current demographic studies, using examples from co-author Herschel Sarnoff's classroom in the Watts section of Los Angeles. They discuss theoretical and conceptual approaches that support student learning with GIS and provide resources…

Alibrandi, Marsha; Sarnoff, Herschel M.

2006-01-01

101

Essie's Story: The Life and Legacy of a Shoshone Teacher. American Indian Lives.  

ERIC Educational Resources Information Center

|The life story of Esther Burnett Horne records the memories and experiences of a Native woman born in 1909, who was both pupil and teacher in Bureau of Indian Affairs boarding schools. An introduction by Sally McBeth examines methodological and cultural concerns of collecting and co-authoring a life history. In Chapter 1, Essie begins with oral…

Horne, Esther Burnett; McBeth, Sally

102

Realpolitiks vs the Long(er) Duree of Cultural and Epistemological Shifts  

Microsoft Academic Search

Michal Osterweil is Lecturer and Director of internships at the University of North Carolina Chapel Hill. Her research focuses on contemporary social movements and their knowledge production. She is currently co-authoring a textbook on Social Movements to be published by Routledge in 2011. Osterweil lives in Carrboro, where she is involved in various community projects including the Carrboro Greenspace and

Michal Osterweil

2011-01-01

103

Positioning New Patterns of Privilege in Learning: A Response to Ware  

ERIC Educational Resources Information Center

This special series represents collective courage because what is willing to be risked may be profound. At center is a willingness to reach out and cultivate new conversations on disability. Indeed, the artists who contribute to Ware's article are key co-authors; their art ushers us into a new disability literacy that extends and challenges…

Paxton-Buursma, Debra J.; Mariage, Troy V.

2011-01-01

104

Journal of Geophysical Research Publications: Community Characteristics  

NASA Astrophysics Data System (ADS)

Do earth science publications differ by subfield or gender? To figure this out we analyzed publications in JGR Atmosphere, Oceans, and Solid Earth for the year 2000. We assumed that the first author exerted controlling influence over publication characteristics and then we looked at the number of co-authors, number of institutions represented by co-author affiliations, page length of the article, number of references cited, number of subject categories represented in the cited references, number of times the article was cited, and the time between the date the article was submitted and the date when it was accepted for publication. We found that, within each field, there was remarkable similarity between the publications led by women and those led by men. Interesting differences showed up between subfields: for example, Solid Earth authors use more references than do authors publishing in Atmosphere or Oceans.

Pfirman, S. L.; Porter, A.

2009-12-01

105

Asian Wave in Travel and Tourism Research  

Microsoft Academic Search

Although numerous tourism-related articles have been published by authors affiliated with Asian universities, operationalized here as the “Asian Wave,” little research effort has focused on examining such authorship. Adopting a publication counting method, this study analyzes articles published in four top tourism journals from 1999–2008 that are either Asia-focused or co-authored by researchers from Asian universities. The results reveal that

Daniel Leung; Rosanna Leung; Billy Bai; Rob Law

2011-01-01

106

Dynamically mapping screen real estate optimality  

Microsoft Academic Search

This research paper brings together the fields of systems engineering and media studies to investigate the cinema\\/television\\/computer\\/mobile device screen as a dynamic interface through which points of engagement or how the aesthetics and narrative structures presented on the screen engage the user and create meaning. The co-authors work towards the development of a “screen real estate grammar” or ontology by

Luigi Benedicenti; Sheila Petty

2010-01-01

107

Science and religion in a high school physics class: revisiting the source materials of ``The interaction of scientific and religious discourses''  

NASA Astrophysics Data System (ADS)

In and with this text, I introduce the Forum that centers around a series of essays written by a high school student and an interview with his teacher all collected as part of a larger study about students' discourses with respect to (nature of) science, learning, and knowing. I provide a brief review of the original findings, which had been published in a study co-authored by the student and myself, his physics teacher.

Roth, Wolff-Michael

2010-03-01

108

Critical Mathematics Pedagogy: Transforming Teachers' Practices  

Microsoft Academic Search

This study reports the effects of a graduate-level mathematics education course that focused on critical theory and teaching for social justice on the pedagogical philosophies and practices of three mathematics teachers (middle, high school, and 2-year college). The study employed Freirian participatory research methodology; in fact, the participants were not only co- researchers, but also co-authors of the study. Data

David W. Stinson; Carla R. Bidwell; Christopher C. Jett; Ginny C. Powell; Mary M. Thurman

109

The Implications Of State Farm v. Campbell For The Future Of Punitive Damages In Bad Faith Litigation  

Microsoft Academic Search

(Editor's Note: Evan Tager is a partner in the Washington, D.C., office of Mayer, Brown, Rowe & Maw, and is co-chair of the firm's appellate practice group. Mr. Tager has long been involved in litigating punitive damages cases in state and federal appellate courts and in the United States Supreme Court. He co-authored a brief for the Chamber of Commerce

Evan M. Tager

110

Product Development for Successive Generations: Creating Decision Support Graphic Information by the Modeling Approach  

Microsoft Academic Search

This study adopts the modeling approach described by Kusaka and co-authors. It aims at specifying fundamental approaches for product development (PD) in order to gain long-range competitive advantages and to create decision support information. Two approaches are introduced: the long-range approach introduces product functions and technologies over successive generations of products as and when they become appropriate; the short-range approach

Y. Kusaka; Y. Nakamura; J. Brogan

2007-01-01

111

Using Rituals and Traditions to Create Classroom Community for Children, Teachers, and Parents  

Microsoft Academic Search

This article addresses the value of teachers establishing rituals and traditions in early childhood classrooms. Using the\\u000a lens of a particular preschool classroom, where one of the co-authors taught for many years, the article describes specific\\u000a traditions that have been established over the years and how these rituals, activities, and events helped to create community\\u000a among the teachers, parents, and

Patricia Scully; Jacqueline Howell

2008-01-01

112

Visualisation of Palaeomagnetic Databases: Progress and Perspectives  

Microsoft Academic Search

A set of Palaeomagnetic Databases (GPMDB, TRANS, SECVR, SECVRL, PALIN, MAGST) created and developed by Michael McElhinny and his co-authors in nineties are used by researchers all over the world. Their user-riendly interfaces make it unnecessary for users to learn about details of the Microsoft Access software. The next step in the development of these databases lies in the visualisation

S. A. Pisarevsky

2003-01-01

113

Nucleoside diphosphate kinase (NDPK, NM23, AWD): recent regulatory advances in endocytosis, metastasis, psoriasis, insulin release, fetal erythroid lineage and heart failure; translational medicine exemplified  

Microsoft Academic Search

The guest editor (AM) provides his perspective on the most recent advances on nucleoside diphosphate kinase (NDPK, otherwise\\u000a known as AWD or NM23) showcasing phospho-histidine biochemistry and its impact on diverse pathology when disordered. His co-author\\u000a (SO) provides state-of-the-art analyses from the European institute of Bioinformatics in an appendix to support the most recent\\u000a advances made by the NDPK community.

Anil Mehta; Sandra Orchard

2009-01-01

114

On Being Called an Anti-Semite in Montana  

ERIC Educational Resources Information Center

|As the coordinator of a university lecture series, the author is always on the lookout for good speakers. He thought that he had found one in Stephen Walt, a political scientist at Harvard University and the co-author of an article about the influence of the pro-Israel lobby on U.S. foreign policy in the Middle East. In this article, the author…

Drake, Richard

2007-01-01

115

Double-Level Languages and CoOperative Working  

Microsoft Academic Search

Four criteria are discussed as important conditions of successful applications in Computer Supported Co-operative Work (CSCW). They are equality, mutual influence, new competence, and double-level language. The criteria originate in the experience of the International Co-operative Movement. They are examined and illustrated withreference to eight contemporary CSCW applications: meeting scheduling and support; bargaining; co-authoring; co-ordination; planning; design support and collaborative

Mike Robinson

1991-01-01

116

A study of interdisciplinarity in information science: using direct citation and co-authorship analysis  

Microsoft Academic Search

This study uses two bibliometric methods, direct citation and co-authorship, to investigate the interdisciplinary changes in information sciences during 1978—2007. The disciplines of references and co-authors from five information science journals were analysed. Furthermore, Brillouin’s Index was adopted to measure the degree of interdisciplinarity. The study revealed that information science researchers have cited the publications of library and information science

Mu-Hsuan Huang; Yu-Wei Chang

2011-01-01

117

Critical Error: Tom Daschle's Blurred Health Care Vision  

Microsoft Academic Search

Tom Daschle's new book, Critical: What Can We Do About the Health-Care Crisis, confirms that advocates for a complete government takeover of American health care have learned an important lesson: Don't try it in one big bite. Here Daschle and co-author Jeanne Lambrew have direct experience. Mr. Daschle was a Democratic leader in the Senate during the push for \\

John R. Graham

118

(Quantitative structure-activity relationships in environmental toxicology)  

SciTech Connect

The traveler attended the Fourth International Workshop on QSAR (Quantitative Structure-Activity Relationships) in Environmental Toxicology. He was an author or co-author on one platform and two poster presentations. The subject of the workshop offers a framework for analyzing and predicting the fate of chemical pollutants in organisms and the environment. QSAR is highly relevant to the ORNL program on the physicochemical characterization of chemical pollutants for health protection.

Turner, J.E.

1990-10-04

119

Library And Information Science Research in Developing Countries and Eastern European Countries: A Brief Bibliometric Perspective  

Microsoft Academic Search

We examined a set of 21 core journals in the field of library and information science (LIS) from 1980–1999 for articles with either principal or co-authors from developing countries (DCs) and the formerly socialist Eastern European countries (EECs). We found that only 826 (7·9%) of a total of 10 400 articles published in 21 journals are from DCs or EECs.

ALI UZUN

2002-01-01

120

TheWriting Fellow\\/Faculty Collaboration in a Community College: Paradigms of Teaching and Learning Across the Curriculum  

Microsoft Academic Search

\\u000a This chapter describes the transformative effects of the collaboration between a graduate student Writing Fellow and two faculty\\u000a members in the development of two Writing Intensive (WI) sections of a history course at Hostos Community College, an urban,\\u000a bilingual college in the south Bronx. The co-authors, formerly WAC Coordinator and Fellow, and now WAC Co-Coordinators draw\\u000a on their unique perspectives

Linda Hirsch; Andrea Fabrizio

121

Quantum Theta Functions and Gabor Frames for Modulation Spaces  

Microsoft Academic Search

Representations of the celebrated Heisenberg commutation relations in quantum mechanics (and their exponentiated versions)\\u000a form the starting point for a number of basic constructions, both in mathematics and mathematical physics (geometric quantization,\\u000a quantum tori, classical and quantum theta functions) and signal analysis (Gabor analysis). In this paper we will try to bridge\\u000a the two communities, represented by the two co-authors:

Franz Luef; Yuri I. Manin

2009-01-01

122

Public Service, Governance and Web 2.0 Technologies : Future Trends in Social Media  

Microsoft Academic Search

Edited by Ed Downey and Matt Jones.Imncludes a chapter co-authored by two College at Brockport faculty members: Melchor De Guzman and Korni Swaroop Kumar: Using Web 2.0 as a Community Policing Strategy: An Examination of the United States Municipal Police Departments.Web 2.0 can create value for political processes by decreasing costs and increasing opportunities for civic engagement, and, as a

Edward H. Downey; Matthew A. Jones; Melchor De Guzman; Korni Swaroop Kumar

2012-01-01

123

Wisdom, goodness and power: Elizabeth Cady Stanton and the history of woman suffrage  

Microsoft Academic Search

In the first three volumes of the History of Woman Suffrage, Elizabeth Cady Stanton and her co-authors crafted a rhetorical history that not only celebrated Stanton's role in the suffrage\\u000a movement, but also promoted her broader, more radical vision of complete gender equality. In the context of a movement divided\\u000a over strategy, Stanton and her editors made the case not

Lisa Shawn Hogan

2006-01-01

124

Multidisciplinarity, interdisciplinarity, and patterns of research collaboration in nanoscience and nanotechnology  

Microsoft Academic Search

This paper first describes the recent development that scientists and engineers of many disciplines, countries, and institutions\\u000a increasingly engage in nanoscale research at breathtaking speed. By co-author analysis of over 600 papers published in “nano\\u000a journals” in 2002 and 2003, I investigate if this apparent concurrence is accompanied by new forms and degrees of multi- and\\u000a interdisciplinarity as well as

Joachim Schummer

2004-01-01

125

Paraeducators in Physical Education : A Training Guide to Roles and Responsibilities  

Microsoft Academic Search

Edited by College at Brockport faculty member Lauren J. Lieberman.Also includes a chapter by College at Brockport faculty member Douglas Collier: Positive methods for dealing with difficult behavior, and chaopters co-authored by College at Brockport alumni Rocco Aiello: Instruction strategies; and Carin Mulawka: Assessment.Paraeducators work in virtually every school—but until now, no systematic training program has existed to teach them

Lauren J. Lieberman; Douglas Collier; Carin Mulawka; Rocco Aiello

2007-01-01

126

Re?imagining Infrastructure  

Microsoft Academic Search

A senior executive of Booz Allen Hamilton and co?author of a business bestseller called Megacommunities argues that the United States is locked into an obsolete pattern of dealing with infrastructure investment, even as the country's population growth and technology have raced ahead. Three of America's basic “lifeline” infrastructures—energy, transportation, and water—are nearing the end of their useful operating lives and

Mark Gerencser

127

Re?imagining Infrastructure  

Microsoft Academic Search

A senior executive of Booz Allen Hamilton and co?author of a business bestseller called Megacommunities argues that the United States is locked into an obsolete pattern of dealing with infrastructure investment, even as the country's population growth and technology have raced ahead. Three of America's basic “lifeline” infrastructures—energy, transportation, and water—are nearing the end of their useful operating lives and

Mark Gerencser

2011-01-01

128

Obituary: Peter Robert Wilson, 1929-2007  

Microsoft Academic Search

It is with great sadness that I report the passing of Peter Robert Wilson, a well-known and well-loved figure in the solar physics community. Peter was on the faculty of the Department of Applied Mathematics at the University of Sydney for 39 years, and Chair of the department for 24 of these years. He was the author or co-author of

Herschel B. Snodgrass

2009-01-01

129

Some methodological problems in ranking scientists by citation analysis  

Microsoft Academic Search

A sample of 80 Hungarian scientists, authors or co-authors of a total number of 6273 papers—published between 1930–1976—has been analysed. Citation data to eachpaper were collected form the 1964–76 SCI's by manual search. Citation counts were distinguished with respect to the following categories: (I) the set of cited authors has element(s) common with the set of citing authors (self citation),

G. Folly; B. Hajtman; J. I. Nagy; I. Ruff

1981-01-01

130

Techniques of Flavonoid Identification  

Microsoft Academic Search

As a follow-up to Dr Markham's highly successful publication, The Systematic Identification of Flavonoids (1970) co-authored with T.J. Mabry and M.B. Thomas, this book presents a more extensive, up-to-date and thorough guide to techniques used in flavonoid research. The techniques are discussed in the approximate order in which they are normally needed by the researcher and extensive cross-referencing is used

K. R. Markham

1982-01-01

131

Towards Semantic Social Networks  

Microsoft Academic Search

Computer manipulated social networks are usually built from the explicit assertion by users that they have some relation with\\u000a other users or by the implicit evidence of such relations (e.g., co-authoring). However, since the goal of social network\\u000a analysis is to help users to take advantage of these networks, it would be convenient to take more information into account.\\u000a We

Jason J. Jung; Jérôme Euzenat

2007-01-01

132

Food and Gender in Bagdad Cafe  

Microsoft Academic Search

The 1988 West German film, Bagdad Cafe (Out of Rosenheim), was based on a screenplay co-authored by director Percy Adlon, producer Eleanor Adlon, and screenwriter Christopher Doherty.1 Given the primary craftspeople involved, when Bagdad Cafe was released in the U.S., it was considered a European film, even though the international co-production was in English, had a predominately American cast, and

Cynthia Baron

2003-01-01

133

Kunio Kawamata on Hugo F. Sonnenschein  

Microsoft Academic Search

The basic idea of the paper is contained in my Ph.D. thesis submitted to the University of Minnesota in 1972. I would like\\u000a to mention the names of the three professors who helped me to complete the Ph.D. thesis. One is Ed Foster, who was then the\\u000a chief adviser to the graduate students, and was also the co-author of the

Kunio Kawamata

134

Mentoring Interns and Postdoctoral Residents in Academic Health Sciences Center  

Microsoft Academic Search

This article was co-authored by a senior mentor and one of her students who worked with her as both an intern and a postdoctoral\\u000a fellow. It is an expanded version of a presentation given by the first author after receiving the Association of Psychologists\\u000a in Academic Health Centers (APAHC) Distinguished Achievement in Teaching Award. The article offers a historical view

Nadine J. Kaslow; Nathan A. Mascaro

2007-01-01

135

Awareness, Planning and Joint Attention in Collaborative Writing: From Fieldwork to Design  

Microsoft Academic Search

This paper reports on a qualitative study of collaboration in the construction and editing of complex documents. Using the theory of distributed cognition, we describe how co-authors edit a document in both co-located and remote settings. To account for higher-level awareness and planning processes, we extend the theory of distributed cognition to include the notion of meta-representations. We show how

Andrew L. Cohen; Debra Cash; Michael J. Muller

1999-01-01

136

Network Effects on Scientific Collaborations  

PubMed Central

Background The analysis of co-authorship network aims at exploring the impact of network structure on the outcome of scientific collaborations and research publications. However, little is known about what network properties are associated with authors who have increased number of joint publications and are being cited highly. Methodology/Principal Findings Measures of social network analysis, for example network centrality and tie strength, have been utilized extensively in current co-authorship literature to explore different behavioural patterns of co-authorship networks. Using three SNA measures (i.e., degree centrality, closeness centrality and betweenness centrality), we explore scientific collaboration networks to understand factors influencing performance (i.e., citation count) and formation (tie strength between authors) of such networks. A citation count is the number of times an article is cited by other articles. We use co-authorship dataset of the research field of ‘steel structure’ for the year 2005 to 2009. To measure the strength of scientific collaboration between two authors, we consider the number of articles co-authored by them. In this study, we examine how citation count of a scientific publication is influenced by different centrality measures of its co-author(s) in a co-authorship network. We further analyze the impact of the network positions of authors on the strength of their scientific collaborations. We use both correlation and regression methods for data analysis leading to statistical validation. We identify that citation count of a research article is positively correlated with the degree centrality and betweenness centrality values of its co-author(s). Also, we reveal that degree centrality and betweenness centrality values of authors in a co-authorship network are positively correlated with the strength of their scientific collaborations. Conclusions/Significance Authors’ network positions in co-authorship networks influence the performance (i.e., citation count) and formation (i.e., tie strength) of scientific collaborations.

Uddin, Shahadat; Hossain, Liaquat; Rasmussen, Kim

2013-01-01

137

Iatrogenic delirium and coma: a "near miss".  

PubMed

A 66-year-old woman was cared for at two referral institutions following a witnessed cardiac arrest in a local emergency department. Despite aggressive initial care, she failed to regain consciousness during a 28-day course. Based on an erroneous neurologic diagnosis of anoxic encephalopathy, pessimism regarding likelihood of improvement existed, prompting clinical consideration of withdrawal of care. The correct diagnosis of iatrogenic drug-induced coma alternating with drug-induced delirium only became apparent after the IV administration of repeated doses of a benzodiazepine antagonist. The patient and husband (co-authors) provide insights often unheard within care circles. PMID:18460520

Dunn, William F; Adams, Shirley C; Adams, Robert W

2008-05-01

138

Looking for Daisy: constructing teacher identities  

NASA Astrophysics Data System (ADS)

Research on teacher identities is both important and increasing. In this forum contribution I re-interpret assertions about an African American science teacher's identities in terms of Jonathon Turner's (2002) constructs of role identity and sub-identity. I contest the notion of renegotiation of identities, suggesting that particular role identities can be brought to the foreground and then backgrounded depending on the situation and the need to confirm a sub-identity. Finally, I recommend the inclusion of teachers' voices in identity research through greater use of co-authoring roles for teachers.

Ritchie, Stephen M.

2009-09-01

139

International Soil Reference and Information Centre  

NSDL National Science Digital Library

The International Soil Reference and Information Centre (ISRIC), which is associated with the Centre for Development and Environment, University of Berne, Switzerland, aims to "provide a better understanding of soils and to promote sustainable use of the land." The ISRIC Web site gives visitors several areas to explore, but of special note are the reports and publications link within the publications page, which contains downloadable annual and biannual reports, conference proceedings, soil briefs, technical papers, and more. These publications have been authored or co-authored by staff members, and guest researchers of ISRIC or the former International Soil Museum.

2008-01-01

140

International Soil Reference and Information Centre  

NSDL National Science Digital Library

The International Soil Reference and Information Centre (ISRIC), which is associated with the Centre for Development and Environment, University of Berne, Switzerland, aims to "provide a better understanding of soils and to promote sustainable use of the land." The ISRIC Web site gives visitors several areas to explore, but of special note are the reports and publications link within the publications page, which contains downloadable annual and biannual reports, conference proceedings, soil briefs, technical papers, and more. These publications have been authored or co-authored by staff members, and guest researchers of ISRIC or the former International Soil Museum.

2001-01-01

141

Internet Research News/ ResearchBuzz  

NSDL National Science Digital Library

A companion site to the book Official Netscape Guide to Internet Research (2nd edition), this current awareness resource features a selection of Internet finds on a variety of topics, with a primary focus on tools for research and more efficient searching online. Updated several times a week, the site and its weekly email newsletter, ResearchBuzz, are maintained by Tara Calishain, the book's co-author. Additional resources at the site include a periodic series of articles on Internet research, Quick Tips for searching online, and an internal search engine.

142

Integrated Access to Solar Observations With EGSO  

Microsoft Academic Search

{\\\\b Co-Authors}: J.Aboudarham (2), E.Antonucci (3), R.D.Bentely (4), L.Ciminiera (5), A.Finkelstein (4), J.B.Gurman(6), F.Hill (7), D.Pike (8), I.Scholl (9), V.Zharkova and the EGSO development team {\\\\b Institutions}: (2) Observatoire de Paris-Meudon (France); (3) INAF - Istituto Nazionale di Astrofisica (Italy); (4) University College London (U.K.); (5) Politecnico di Torino (Italy), (6) NASA Goddard Space Flight Center (USA); (7) National Solar

A. Csillaghy

2003-01-01

143

The case for creating a model insurance policy: payer coverage of breastfeeding counseling services, pumps, and supplies.  

PubMed

Abstract With the implementation of the Health Resources and Services Administration Women's Preventive Services Guidelines, which went into effective August 1, 2012, under the Affordable Care Act, healthcare insurance companies across the country have interpreted the breastfeeding support provision in a variety of ways. In order to improve benefit design and promote transparency and accountability, the National Breastfeeding Center and the United States Breastfeeding Committee co-authored a model insurance policy that seeks to educate insurance executives about appropriately supporting breastfeeding medicine for purposes of improving population health. PMID:24112064

Madden, Susanne; Curtis, Beverly

2013-10-01

144

Retraction: Wettability-gradient-driven micropump for transporting discrete liquid drops  

NASA Astrophysics Data System (ADS)

This is a Retraction for the article 2013 J. Micromech. Microeng. 23 035036. The science reported in this article is not incorrect. This article does not include all co-authors who contributed to the work. The article incorrectly attributes work performed at the University of California to the University of Jordan, and fails to acknowledge contributions from Georgia Institute of Technology. This article does not acknowledge the sources of funding for the work and the reference list is incomplete. This article was submitted by Hamzeh K Bardaweel without the knowledge of the other authors.

Bardaweel, Hamzeh K.; Zamuruyev, Konstantin; Delplanque, Jean-Pierre; Davis, Cristina E.

2013-06-01

145

Journey of change and back: a case study of a reconstituted social work service.  

PubMed

As a result of Total Quality Management and Reengineering principles during the VA's "Journey of Change" in the mid-1990s many hospital social work departments were re-organized under umbrella-care lines. Outcome studies of this movement have focused primarily on patient services. This study focused on the service providers' (including social workers) point of view and their satisfaction with the change in service structure. Data gathering consisted of a master thesis project by one of the co-authors, an administrative in-house survey of staff satisfaction, a qualitative presentation of staff concerns, and the perspective of the administrator who took the decision. PMID:18956511

Alvelo, Jaime; Garcia, Jerika; Rosario, David

2008-01-01

146

[Health: this is what women have said...].  

PubMed

Co-authored by a number of prominent Québec women, including former federal health minister Monique Bégin, this award-winning anthology examines a number of issues from a feminist perspective. Among them: violence against women; nutrition; the reconciliation of motherhood with the world of work; infertility and new reproductive technologies; and the politics underlying the debate over midwives. The book should help women to grasp the important notion of autonomy in dealing with their state of health and at the same time touch all nurses, say the authors of the article. PMID:2039982

Gendron, C; Beauregard, M

1991-03-01

147

Have We Hatched the Addiction Egg: Reward Deficiency Syndrome Solution System(TM)  

PubMed Central

This article co-authored by a number of scientists, ASAM physicians, clinicians, treatment center owners, geneticists, neurobiologists, psychologists, social workers, criminologists, nurses, nutritionist, and students, is dedicated to all the people who have lost loved ones in substance-abuse and “reward deficiency syndrome” related tragedies. Why are we failing at reducing the incidence of ‘Bad Behaviors’? Are we aiming at the wrong treatment targets for behavioral disorders? We are proposing a paradigm shift and calling it “Reward Deficiency Solution System” providing evidence for its adoption.

Downs, BW; Oscar-Berman, M; Waite, RL; Madigan, MA; Giordano, J; Beley, T; Jones, S; Simpatico, T; Hauser, M; Borsten, J; Marcelo, F; Braverman, ER; Lohmann, R; Dushaj, K; Helman, M; Barh, D; Schoenthaler, ST; Han, D; Blum, K

2013-01-01

148

Resolving dilemmas through bodywork.  

PubMed

Pamela Ellen Ferguson and Debra Persinger, co-authors and co-editors of Sand to Sky-Conversations with Teachers of Asian Medicine (Bloomington, IN: iUniverse; 2008), interview Marianne Steele in Germany on her shiatsu and massage therapy work in various forms of trauma and posttraumatic stress disorder. The interview was conducted in a series of e-mail exchanges and telephone calls during late 2009 and early 2010 and is intended for a future German edition of Sand to Sky. PMID:21589702

Ferguson, Pamela Ellen; Persinger, Debra; Steele, Marianne

2010-03-17

149

Olgierd (Olek) Cecil Zienkiewicz (1921-2009): A Biographical Tribute  

NASA Astrophysics Data System (ADS)

In this tribute the authors present a personal and academic biography of O. C. Zienkiewicz.(1921-2009) who is recognized as having been one of the pioneers of the Finite Element Method. O. C. Zienkiewicz co-authored the first text book on the method which was largely responsible for the introduction of the concept to a worldwide audience. His contribution to the computational mechanics community encompasses structural, geotechnical and fluid flow analysis as well as numerous fundamental finite element developments. This paper presents these achievements within the context of his life and includes personal recollections by the authors who were his colleagues.

Roger, D.; Owen, J.; Wood, Richard D.

2010-06-01

150

Riley Guide: Employment Opportunities and Job Resources on the Internet  

NSDL National Science Digital Library

The Riley Guide was one of the earliest Web sites dedicated to job resources. The site contains introductions and annotated pointers to resources by career field, employer type, and location. There are also sections on resume preparation, and recruiting online, as well as handouts for libraries to use with patrons wanting to use the Internet for job hunting. Margaret Riley is a columnist for the National Business Employment Weekly and is one of the co-authors of the 1996 book, The Guide to Internet Job Searching.

1998-01-01

151

Distribution of electron density in charged Li@C60 complexes  

NASA Astrophysics Data System (ADS)

The Letter is an expanded commentary to the paper 'Fullerene as an electron buffer: charge transfer in Li@C60', by Pavanello and co-authors [8]. We calculated the electron density distribution in the space inside and outside the fullerene cage in Li@C60 complexes differing in total charge, based on Gauss's law. It allowed us to determine the charges contained inside surfaces isomorphic with the fullerene cage and contracted or enlarged with respect to the latter. For every complex, a surface was found in the vicinity of the central Li atom such that the charge enclosed within it was equal to +1.

Sadlej-Sosnowska, Nina; Mazurek, Aleksander P.

2013-08-01

152

Scientific and Technical Information (STI)....what`s the status?  

SciTech Connect

In 1982, the Pacific Northwest Laboratory (PNL) developed an electronic Publications and Presentations Registry designed to track Scientific and Technical Information (STI) products through PNL and Department of Energy (DOE) programmatic reviews. All information forwarded to the Office of Scientific and Technical Information (OSTI) for release (e.g., public, UCNI, Export Control) is included in the database. The database contains client and programmatic information for all STI generated by PNL. This electronic format is currently one of the most comprehensive resources for PNL authored and co-authored documents on the Hanford Site.

Varley, D.A.

1993-12-01

153

Final Report to the Subsurface Science Program - Impact of Measurement Instrument and Conceptual Model on Analysis of Subsurface Heterogeneity  

SciTech Connect

This final report covers results of research initially focused on particle transport and then extended to study of measurement scale and scaling. Experimental, numerical, and theoretical findings were published in the areas of hydraulics in heterogeneous media, particle-chemical-microbial transport in heterogeneous media, sampling design, stochastics and wellhead protection. This work has resulted in 17 journal publications, a number of conference presentations, two Ph.D. dissertations, two Master's theses, and two manuscripts upon which undergraduate students have been co-authors.

Silliman, Stephen E.

2003-01-10

154

Add your voice to the history of bygone psychiatric institutions.  

PubMed

LECTURER IN mental health at King's College London Niall McCrae wants to hear from nurses who worked at any of the large British psychiatric institutions before their closure. Dr McCrae, a Nursing Management editorial advisory board member, is writing a history of nursing in the former asylums. Echoes from the Corridors: The Story of Nursing in the Mental Hospitals in Britain, co-authored with Peter Nolan, will be published in 2015. Email n.mccrae@kcl.ac.uk or call 020 7848 3619. PMID:24164065

2013-11-01

155

Boston University Digital Common  

NSDL National Science Digital Library

Boston University has a range of scholars, from those who research the hospitality field to others who are fascinated by the world of photonics. The University's Digital Common Repository contains thousands of documents and publications that span this wide range, authored or co-authored by BU faculty, students, and staff. The different communities here are divided into sections that include College of Arts and Sciences, Centers & Institutes, and Metropolitan College. Visitors will find religious sermons, pieces of music, working economics papers, and a vast cornucopia of other materials. Also, visitors are encouraged to use the Browse feature to look for documents by title, subject, author, or date.

156

Reflections on a scientific paper of 1926 by the medical 'Inkling' Robert Emlyn 'Humphrey' Havard (1901-1985).  

PubMed

Robert Emlyn Havard (1901-1985; general practitioner and sometimes medical scientist) was the only non-literary member of the Inklings - a 1930 s and 1940s Oxford University club which included Lewis and Tolkien. Despite spending most of his time in family medicine, Havard was a productive medical scientist. While still a student at Cambridge University, Havard co-authored an influential study published in the Journal of Physiology of 1926 entitled 'The influence of exercise on the inorganic phosphates in the blood and urine'. The style and structure of this paper provides a charming window into the elite medical science of the 1920s. PMID:19297104

Charlton, Bruce G

2009-03-17

157

What can we learn from the Hwang and Sudbø affairs?  

PubMed

The recent publication, in prestigious scientific journals, of two major studies that were subsequently shown to contain fabricated data may compel reviewers and editors to adopt a more rigorous policy in accepting articles for publication. The current manner of peer reviewing research articles provides no assurance that the proffered work is not the result of fraud. The present guidelines for contributors in large team investigations may need to be updated to avoid giving credit to co-authors who may have made little, if any, contribution to the work. PMID:16803444

Gerber, Paul

2006-06-19

158

Revised Views of Classroom Assessment  

NSDL National Science Digital Library

The Classroom Assessment Project to Improve Teaching and Learning (CAPITAL), a collaborative research initiative between Stanford University and middle school science teachers in nearby school districts, examined classroom-based assessment in science. The teachers shared ideas with one another, and the university staff introduced research findings and ideas into the conversations. The CAPITAL teachers co-authoring this chapter described themselves as moving away from the role of teacher as giver of grades to teacher as conductor of learning. They increased their interactions with students during class time and better assisted students toward achieving the learning goals.

Fong, Elaine; Gilbertson, Joni; Sato, Mistilina; Schwartzfarb, Neil; Liebig, Tracey; Baker, Vicki

2006-01-01

159

Final Technical Report-Grant # DE-FG02-97ER45628 ?Structural Diorder in Materials?  

SciTech Connect

Since the grant was renewed in 2000 and 2003 final technical reports of the grant have been previously submitted for those years. For that reason this final technical report covers the last four years of the grant. We had an exceptionally successful and productive last four years under the support of the grant. Our progress takes three different aspects, described in more detail below: 1.1 instrumentation, infrastructure, and other research support at Sector 20 of the Advanced Photon Source (APS); 1.2 research on which Profs. Stern or Seidler were PI?s; and 1.3 research on which Profs. Stern or Seidler were co-PI?s or where Drs. Dale Brewe or Julie Cross were authors or co-authors. Drs. Brewe and Cross are the two research scientists (permanently stationed at sector 20) who are supported by the grant. They provide support to the scientific goals of the grant and more broadly provide research support for many general users at Sector 20. Finally, in section 1.4 we provide a complete list of publications resulting from funding in the grant on which at least one of Stern, Seidler, Cross, or Brewe were co-authors. Given the inclusion of operations funding in the grant, this is of course a subset of the full scientific impact of the grant.

Stern, Edward A

2009-02-23

160

Elective Clinical Target Volumes for Conformal Therapy in Anorectal Cancer: A Radiation Therapy Oncology Group Consensus Panel Contouring Atlas  

SciTech Connect

Purpose: To develop a Radiation Therapy Oncology Group (RTOG) atlas of the elective clinical target volume (CTV) definitions to be used for planning pelvic intensity-modulated radiotherapy (IMRT) for anal and rectal cancers. Methods and Materials: The Gastrointestinal Committee of the RTOG established a task group (the nine physician co-authors) to develop this atlas. They responded to a questionnaire concerning three elective CTVs (CTVA: internal iliac, presacral, and perirectal nodal regions for both anal and rectal case planning; CTVB: external iliac nodal region for anal case planning and for selected rectal cases; CTVC: inguinal nodal region for anal case planning and for select rectal cases), and to outline these areas on individual computed tomographic images. The imaging files were shared via the Advanced Technology Consortium. A program developed by one of the co-authors (I.E.N.) used binomial maximum-likelihood estimates to generate a 95% group consensus contour. The computer-estimated consensus contours were then reviewed by the group and modified to provide a final contouring consensus atlas. Results: The panel achieved consensus CTV definitions to be used as guidelines for the adjuvant therapy of rectal cancer and definitive therapy for anal cancer. The most important difference from similar atlases for gynecologic or genitourinary cancer is mesorectal coverage. Detailed target volume contouring guidelines and images are discussed. Conclusion: This report serves as a template for the definition of the elective CTVs to be used in IMRT planning for anal and rectal cancers, as part of prospective RTOG trials.

Myerson, Robert J. [Department of Radiation Oncology, Washington University, St. Louis, MO (United States)], E-mail: myerson@radonc.wustl.edu; Garofalo, Michael C. [Department of Radiation Oncology, University of Maryland Medical Center, Baltimore, MD (United States); El Naqa, Issam [Department of Radiation Oncology, Washington University, St. Louis, MO (United States); Abrams, Ross A. [Department of Radiation Oncology, Rush University Medical Center, Chicago, IL (United States); Apte, Aditya; Bosch, Walter R. [Department of Radiation Oncology, Washington University, St. Louis, MO (United States); Das, Prajnan [Department of Radiation Oncology, University of Texas, MD Anderson Cancer Center, Houston, TX (United States); Gunderson, Leonard L. [Department of Radiation Oncology, Mayo Clinic, Scottsdale AZ (United States); Hong, Theodore S. [Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA (United States); Kim, J.J. John [Department of Radiation Oncology, Princess Margaret Hospital, University of Toronto, Toronto, ON (Canada); Willett, Christopher G. [Department of Radiation Oncology, Duke University, Durham, NC (United States); Kachnic, Lisa A. [Department of Radiation Oncology, Boston University Medical Center, Boston, MA (United States)

2009-07-01

161

New Study Documents the Dramatic Effect of Industrial Fishing across the World's Oceans  

NSDL National Science Digital Library

In a study published in the journal _Nature_, co-authors Ramsom Myers and Boris Worm concluded that 90 percent of the world's large fishes have disappeared from the world's oceans over the past fifty years, attributing this phenomenon to industrial fishing. Utilizing data from the past 47 years, Myers and Worm looked at the precipitous decline in the populations of species such as tuna, marlin, and swordfish. The report noted that the largest population decline began when industrial fishing became increasingly ubiquitous in the early 1950s around the world. As Myers noted in a recent interview, "Humans have always been very good at killing big animals. Ten thousand years ago, with just some pointed sticks, humans managed to wipe out the wooly mammoth, saber tooth tigers, mastodons and giant vampire bats." While several individuals in the fishing industry took exception to the tone of the report, co-author Worm noted that there were potential solutions to the problem, including declaring certain fishing areas as "off-limits." Other experts have commented that it also makes sense for the fishing industry to investigate the expansion of aquaculture, along with a more strict adherence to conservation policies.The first link will take visitors to an online news article from CNN.com about this recent study that contains comments from the co-authors and representatives of the fishing industry. The second link leads to the report by Myers and Worm in the most recent issue of the journal _Nature_. The third link will take visitors to a site maintained by the United Nations Division for Sustainable Development that highlights partnerships and programs developed by various countries to effectively maintain the productivity and viability of their coastlines and surrounding oceans. The fourth link leads to a nice compendium of international fishing treaties and agreements that stretches back to the 1923 Convention for the Preservation of the Halibut Treaty. The fifth link leads to the homepage of the Global Aquaculture Alliance, and contains information about ongoing projects in aquaculture around the world. The final link leads to a site devoted to providing "complete background information on every species of whale, dolphin, and porpoise," along with offering details about whale watching and the evolution of cetaceans. [KMG

Grinnell, Max

162

People Make Places: Growing the Public Life of Cities  

NSDL National Science Digital Library

Demos is a public policy and advocacy think-tank based in Britain that is well-regarded for its diverse studies on such timely issues as urban governance, the public and the media, and a number of other topics. This latest report from co-authors Melissa Mean and Charlie Tims takes on the always-timely theme of how cities might create more effective public spaces in cities that will work well for a wide host of constituencies. The 41-page report is based on intensive qualitative research done in the British towns of Cardiff, Preston, and Swindon. The report has a broad agenda, as it offers a number of suggestions and policy initiatives for how effective public spaces might boost peopleÂs participation in public space and Âthe wider public life of their town or cityÂ.

2005-01-01

163

Vascular smooth muscle function: defining the diabetic vascular phenotype.  

PubMed

In this issue of Diabetologia, a meta-analysis performed by Montero and co-authors (Diabetologia doi 10.1007/s00125-013-2974-1 ) demonstrates a significant impairment of vascular smooth muscle (VSM) function in type 2 diabetic patients. Endothelial function and VSM function between type 2 diabetic and healthy individuals were associated, especially in the microcirculation, confirming the hypothesis that unresponsiveness of VSM cells to NO may amplify the consequences of reduced NO availability. This study suggests a novel interpretation for endothelial dysfunction in diabetic patients, indicating VSM cells as key players. Causative mechanisms of VSM dysfunction, which seems to be a feature of the vascular phenotype of type 2 diabetes mellitus, are largely unexplored in humans. Future studies should also address the crucial issue of the prognostic significance of VSM dysfunction in diabetic patients, and possibly in other conditions characterised by high cardiovascular risk. PMID:23907382

Bruno, Rosa Maria; Ghiadoni, Lorenzo

2013-08-02

164

Bridging the Gap Between Atomistics and Structural Engineering  

NASA Astrophysics Data System (ADS)

When Sid Yip asked me to write a commentary for this section of the handbook, I promptly reminded him that I am a co-author of a longer article in the section on mathematical methods. I told him that my article on amorphous plasticity, written with Michael Falk and Leonid Pechenik, already is more of a departure from conventional ideas than may be appropriate for a book like this one, which should serve as a reliable reference for years into the future; and I asked whether I really ought to be given yet more space for expressing my opinions. Sid insisted that I should write the commentary anyway. So here are some remarks about one of the topics of interest in this book, the search for predictive models of deformation and failure of solids, and the role of nonequilibrium physics in this effort.

Langer, J. S.

165

1988 DOE model conference proceedings: Volume 1  

SciTech Connect

These Proceedings of the October 3-7, 1988, DOE Model Conference are a compilation of the papers that were presented in the technical or poster sessions at the conference. Papers and posters not submitted for publication are not included in the Proceedings. The Table of Contents lists the titles of papers as well as the names of the presenters. These individuals are not, in all cases, the primary authors of the papers published. The actual title pages, appearing later with the papers, show the primary author(s) and all co-authors. The papers in all three volumes of the Proceedings appear as they were originally submitted for publication and have not been edited or changed in any way. Topics included in Volume 1 are Environmental Data Management, Site characterization technology, Wastewater treatment, Waste management in foreign countries, Transuranic waste management, and Groundwater characterization and treatment.

Not Available

1988-01-01

166

1988 DOE model conference proceedings: Volume 4  

SciTech Connect

These Proceedings of the October 3-7, 1988, DOE Model Conference are a compilation of the papers that were presented in the technical or poster sessions at the conference. Papers and posters not submitted for publication are not included in the Proceedings. The Table of Contents lists the titles of papers as well as the names of the presenters. These individuals are not, in all cases, the primary authors of the papers published. The actual title pages, appearing later with the papers, show the primary author(s) and all co-authors. The papers in all three volumes of the Proceedings appear as they were originally submitted for publication and have not been edited or changed in any way. Topics discussed in Volume 4 include site characterization and remediation projects, environmental monitoring and modeling; disposal site selection and facility design, risk assessment, safety and health issues, and site remediation technology.

Not Available

1988-01-01

167

Promoting Interdisciplinary Research in Departments of Medicine: Results from Two Models at Boston University School of Medicine  

PubMed Central

We have sought to broaden our department's research capacity using two different interdisciplinary approaches. First, we created the Evans Center for Interdisciplinary Biomedical Research (ECIBR) — a virtual center that promotes and funds Affinity Research Collaboratives (ARCs) initiated by faculty from within and outside Boston University (BU). Of the 11 funded ARCs, the 4 ARCs in existence for a minimum of 3 years have a total of 37 participants, 93 co-authored publications, and 33 new grants. Second, the Department of Medicine (DOM) created a Section of Computational Biomedicine in 2009 to enhance analytical and computational expertise in the DOM. After 3 years, the section is comprised of 10 faculty members and 21 trainees. The faculty members have collaborated with 20 faculty members in other sections or departments and secured 12 extramural grants (totaling ?$20 million in direct costs). The ECIBR and the Section of Computational Biomedicine represent new organizational approaches to stimulating innovation in research in a DOM.

Coleman, David L.; Spira, Avrum; Ravid, Katya

2013-01-01

168

INTERNATIONAL COLLABORATION ON CO2 SEQUESTRATION  

SciTech Connect

The specific objective of our project on CO{sub 2} ocean sequestration is to investigate its technical feasibility and to improve the understanding of any associated environmental impacts. Our ultimate goal is to minimize any impacts associated with the eventual use of ocean carbon sequestration to reduce greenhouse gas concentrations in the atmosphere. The project will continue through March 31, 2002, with a field experiment to take place in the summer of 2001 off the Kona Coast of Hawaii. At GHGT-4 in Interlaken, we presented a paper detailing our plans. The purpose of this paper is to present an update on our progress to date and our plans to complete the project. The co-authors of this paper are members of the project's Technical Committee, which has been formed to supervise the technical aspects and execution of this project.

H.J. Herzog; E.E. Adams

2000-08-23

169

A Journal Paper Filtering Using the Multiple Information  

NASA Astrophysics Data System (ADS)

A paper filtering system that supports the effective collection of related journal papers is becoming important as the technological progress has been rapid. However, previous systems realized insufficient filtering effectiveness, because of lack of available information in abstract part of journal papers that is available to the public. In this paper, we propose a paper filtering method using the multiple information such as structure, co-author, subject category, terminology, and terms in patent document. By the evaluation for 15 examinees using 4,875 journal papers, it became clear that for all examinees the effectiveness of proposed method exceeds the conventional method, when the all information above are used, which became closer to practical use.

Yamamoto, Masao; Kinukawa, Hiroshi

170

Becoming one person: living with dissociative identity disorder.  

PubMed

Dissociative identity disorder is a rare diagnosis, although people currently with a diagnosis of psychosis may in fact be experiencing what is associated with the disorder. This article is co-authored by a nurse and a person who has lived with alters (multiple personalities) for nearly all of her life. Because of the rarity of the diagnosis, there is much misunderstanding and ignorance among lay people and mental health professionals. This article therefore clarifies historical and contemporary issues surrounding this particular mental health problem both through examining the literature and through narrative of the person's experience. Special attention is given to the reality of coping with the difficulties that dissociative identity disorder create. PMID:16608473

Stickley, T; Nickeas, R

2006-04-01

171

Theory of BCS-BEC Crossover in Ultracold Fermi Gases: Insights into Thermodynamical and Spectroscopic Experiments  

NASA Astrophysics Data System (ADS)

In this talk we summarize our theoretical understanding of the atomic Fermi superfluids with an emphasis on understanding current experiments. We compare and contrast different theoretical approaches for dealing with finite temperature, and discuss their respective implications for these trapped gases. Armed with a basic picture of the thermodynamics we turn to a variety of different measurements based on radio frequency spectroscopy, including both momentum integrated and momentum resolved experiments. As recently reviewed in arXiv 0810.1940 and 0810.1938, we show how a broad range of experimental phenomena can be accomodated within our natural extension of the BCS-Leggett ground state to finite temperature, and briefly touch on the applicability of BCS-BEC crossover theory to the high temperature superconductors. Co-authors: Qijin Chen, Yan He and Chih-Chun Chien

Levin, Kathryn

2009-05-01

172

1988 DOE model conference proceedings: Volume 5  

SciTech Connect

These Proceedings of the October 3--7, 1988 DOE Model Conference are a compilation of the papers that were presented in the technical or poster sessions at the conference papers and posters not submitted for publication are not included in the Proceedings. The Table of Contents lists the titles of papers as well as the names of the presenters. These individuals are not, in all cases, the primary authors of the papers published. The actual title pages, appearing later with the papers, show the primary author(s) and all co-authors. The papers in all three volumes of the Proceedings appear as they were originally submitted for publication and have not been edited or changed in any way. Topics discussed in Volume 5 include environmental assessments and program strategies, waste treatment technologies, and regulations and compliance studies.

Not Available

1988-01-01

173

Lanzerotti to Head New AGU Journal on Space Weather  

NASA Astrophysics Data System (ADS)

Louis J. Lanzerotti has been named editor of a new AGU online publication devoted to the emerging field of near-Earth space conditions and their effects on technical systems. Space Weather: The International Journal of Research and Applications, will be the first journal dedicated solely to the subject, and will include peer-reviewed research, as well as news, features, and opinion articles. A quarterly magazine digest will also be published from the online edition and distributed free of charge to space weather professionals. Lanzerotti, a longtime AGU member who was elected an AGU Fellow in 1985, is currently a consulting physicist at Lucent Technologies Bell Laboratories, and a distinguished research professor at the New Jersey Institute of Technology. He also serves on the governing board of the American Institute of Physics. He is author or co-author of more than 500 publications, including many related to space weather and its effects on communications.

Lifland, Jonathan

174

The development of boronic acids as sensors and separation tools.  

PubMed

Synthetic receptors for diols that incorporate boronic acid motifs have been developed as new sensors and separation tools. Utilizing the reversible interactions of diols with boronic acids to form boronic esters under new binding regimes has provided new hydrogel constructs that have found use as dye-displacement sensors and electrophoretic separation tools; similarly, molecular boronic-acid-containing chemosensors were constructed that offer applications in the sensing of diols. This review provides a somewhat-personal perspective of developments in boronic-acid-mediated sensing and separation, placed in the context of the seminal works of others in the area, as well as offering a concise summary of the contributions of the co-authors in the area. PMID:22791631

Fossey, John S; D'Hooge, Francois; van den Elsen, Jean M H; Pereira Morais, Marta P; Pascu, Sofia I; Bull, Steven D; Marken, Frank; Jenkins, A Toby A; Jiang, Yun-Bao; James, Tony D

2012-07-13

175

Trying differently: A relationship-centered approach to representing clients with cognitive challenges.  

PubMed

This article demonstrates the usefulness of an innovative framework called "Relationship-Centered Lawyering" to enhancing real world legal practice. It uses the example of lawyers, particularly criminal defense lawyers, who often deal with clients with cognitive challenges. The article developed out of a series of workshops conducted jointly by the co-authors, an American law professor with a social work background, and a Canadian criminal defense lawyer and family mediator who is an international expert on Fetal Alcohol Spectrum Disorder and other Neuro-Behavioral Disorders (FA/NB). The paper describes the relational theory Brooks developed (along with Robert Madden), along with the science of cognitive impairments, with a specific focus on FA/NB. The paper provides two illustrations of the relational framework by explaining Boulding's strategy of creating what is called the "external brain" and his techniques of relational interviewing. PMID:20888044

Boulding, David M; Brooks, Susan L

176

Comment on "Soil CO2, CH4 and N2O fluxes from an afforested lowland raised peatbog in Scotland: implications for drainage and restoration" by Yamulki et al. (2013)  

NASA Astrophysics Data System (ADS)

Yamulki and co-authors address in their recent publication the important issue of net emissions of greenhouse gases (GHGs) from peatlands where land use conversion has taken place. In their case, they studied conversion to forestry versus peatland restoration after a first rotation of plantation forestry. They monitored soil-derived fluxes of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) using chamber measurements on planted and unplanted control treatments (with or without drainage), and an unplanted plot within a restored (felled) block on former lowland raised bog. They propose that their measurements of greenhouse gas (GHG) emissions at these sites suggest that the total net GHG emissions, in 100 yr carbon dioxide equivalents, of the restored peatbog would be higher than that of the peatbog with trees. We believe there are a number of issues with the measurement, calculation and comparison of these greenhouse budgets that may invalidate this conclusion.

Artz, R. R. E.; Chapman, S. J.; Saunders, M.; Evans, C.; Matthews, R.

2013-06-01

177

The IEEE Grid Interconnection Standard: How Will it Affect Wind Power?  

SciTech Connect

In December 1998, the Institute of Electrical and Electronic Engineers (IEEE) began writing a standard for the interconnection of distributed resources with electric power systems. This standard will prescribe technical requirements for the interconnection of distributed resources that are connected to primary or secondary voltages in electric distribution systems. It is expected to play a significant role in facilitating a new, emerging market for small, distributed, primarily gas-fired electric generators, including new technologies such as fuel cells and micro-turbines. Once published, this new standard will be enforced for the interconnection of distributed wind power applications, as well. The co-authors of this paper have been active with this standard from the beginning, focusing on issues most likely to affect interconnection of wind power. This paper describes the standard-writing process and highlights technical issues critical to wind power, with the intent of soliciting feedback from an encouraging broader participation by the wind industry.

Green, H.J.; Wind, T.

2000-08-30

178

Relationship Education Research: Current Status and Future Directions  

PubMed Central

The overarching aim of this paper is to review research on relationship education programs and approaches that have been published or accepted for publication since the last review article in 2002. This paper provides a critical overview of the relationship education field and sets an agenda for research and practice for the next decade. A theme weaved throughout the paper are the ways in which relationship education is similar and different from couples therapy and we conclude that there can be a synergistic, healthy marriage between the two. We then provide recommendations for future directions for research in the relationship education field. Finally, the co-authors comment on our experiences in both the relationship education field and couples therapy field as both researchers and interventionists.

Markman, Howard J.; Rhoades, Galena K.

2011-01-01

179

Pierre Curie, 1859-1906  

PubMed Central

The year 2006 marked 100 years since the death of Pierre Curie. It is therefore appropriate that we remember his life and his work, which was cut short by his untimely death from an accident on the Pont Neuf, Paris, on April 19, 1906. He had already accomplished much during his life, both before the discovery of radium with Marie Curie, in work co-authored with his brother Jacques on piezoelectricity, and afterwards, when he published the results of several experimental studies with radium and radon. He came from a medical family, and his grandfather Pierre Curie was a famous homeopathic physician. He has, in print, unfairly been relegated to the background—his own scientific contributions having been overtaken by the fame of Marie Curie, probably because she outlived him by 28 years.

Mould, R.F.

2007-01-01

180

Diagnosing a daily index of tornado variability with global reanalysis  

NASA Astrophysics Data System (ADS)

The recent record setting tornado outbreaks in April 2011 has spurred a lot of discussion and debate of the causes of this record setting month. Global warming and the decaying La Niña were both common causes suggested as the reason behind such a destructive tornado season. Due to the inhomogeneity of the observed tornado record, there are few published studies that relate climate variability to occurrences of tornados. We employ a method developed by Harold Brooks and co-authors in 2003 that discriminates tornadic and severe weather soundings from everyday convection to circumvent the problems with the observed tornado record. We will show how this index, derived from the CFS-R, realistically reproduces the observed variability in tornadoes, and the relative impacts of different modes of climate variability on tornadoes over the United States. This analysis will provide a baseline that will be expanded to climate model simulations of the 20th Century and future projections.

Pegion, P. J.; Hoerling, M. P.

2011-12-01

181

Regularization in Hilbert space under unbounded operators and general source conditions  

NASA Astrophysics Data System (ADS)

The authors study ill-posed equations with unbounded operators in Hilbert space. This setup has important applications, but only a few theoretical studies are available. First, the question is addressed and answered whether every element satisfies some general source condition with respect to a given self-adjoint unbounded operator. This generalizes a previous result from Mathé and Hofmann (2008 Inverse Problems 24 015009). The analysis then proceeds to error bounds for regularization, emphasizing some specific points for regularization under unbounded operators. The study finally reviews two examples within the light of the present study, as these are fractional differentiation and some Cauchy problems for the Helmholtz equation, both studied previously and in more detail by U Tautenhahn and co-authors. To Eberhard Schock on the occasion of his 70th birthday.

Hofmann, Bernd; Mathé, Peter; von Weizsäcker, Heinrich

2009-11-01

182

Effects of Summer Flow Augmentation on the Migratory Behavior and Survival of Juvenile Snake River Fall Chinook Salmon; 2004-2005 Annual Report.  

SciTech Connect

This report summarizes results of research activities conducted in 2004 and years previous to aid in the management and recovery of fall Chinook salmon Oncorhynchus tshawytscha in the Columbia River basin. For detailed summaries, we refer the reader to the abstracts given on the second page of each chapter. The Annual Reporting section includes information provided to fishery managers in-season and post-season, and it contains a detailed summary of life history and survival statistics on wild Snake River fall Chinook salmon juveniles for the years 1992-2004. Publication is a high priority of our staff. Publication provides our results to a wide audience, and it insures that our work meets high scientific standards. The Bibliography of Published Journal Articles section provides citations for peer-reviewed papers co-authored by personnel of project 1991-02900 that were written or published from 1998 to 2005.

Tiffan, Kenneth F. (US Geological Survey, Western Fisheries Research Center, Columbia River Research Laboratory, Cook, WA); Connor, William P. (US Fish and Wildlife Service, Idaho Fishery Resource Office, Ahsahka, ID)

2006-03-01

183

CEOs for Cities  

NSDL National Science Digital Library

The past few years have seen a growing number of organizations, institutions, and national think tanks express an increasing concern for sustaining the competitive economic advantage of major urban areas. One such group is CEOS for Cities, which is a national bipartisan alliance of mayors, corporate executives, university presidents, and other nonprofit leaders whose primary directive is to advance the economic competitiveness of cities. The group's executive committee includes such powerful leaders as Mayor Richard M. Daley of Chicago and Paul S. Grogan, the CEO of the Boston Foundation. One of the site's best features is the Trends and Data Analysis Reports, coupled with the Best Practice reports. Many of these documents are co-authored with other like-minded institutions, such as the Brookings Institution, and delve into such topics as What the IT Revolution Means for Regional Economic Development and Leveraging Colleges and Universities for Urban Economic Revitalization: An Action Agenda.

184

Coldwater fish in wadeable streams  

USGS Publications Warehouse

Standardizing sampling methods for fish populations across large regions is important for consistent measurement of large-scale effects of climate or geography. In addition, pooling samples creates larger sample sizes and can facilitate data sharing among scientists and land managers. Sampling freshwater fish has largely not been standardized due to the diversity of fish and habitats. USGS aquatic ecologist Jason Dunham and co-authors contributed a chapter about sampling coldwater fish in wadeable streams to a new book that details common methods, protocols, and guidelines for sampling fish across North America. Topics include three common sampling methods: electrofishing, snorkeling, and nest counts. Each method provides complementary information about different species and life stages. The information will be useful for initiating new or fine-tuning ongoing sampling programs.

Dunham, Jason B.; Rosenberger, Amanda E.; Thurow, Russell F.; Dolloff, C. Andrew; Howell, Philip J.

2009-01-01

185

Narratives, choices, alienation, and identity: learning from an elementary science teacher  

NASA Astrophysics Data System (ADS)

As we contemplate on teacher identity research, there is a need to place a teacher's narratives or story-lines at the center of that work. In this forum, in response to the insightful commentary from Stephen Ritchie and Maria Iñez Mafra Goulart and Eduardo Soares, I place a greater emphasis on understanding Daisy's narratives from an existing social identity framework. Narratives tell us intricate and complex actions that a teacher has taken both personally and professionally. Additionally, narratives help us see implicit nature of identity explicitly. Therefore, a greater focus has to be placed on interactions and utterances of a teacher to make sense of who they are and what they do as expressed by their own words (identity and action). Finally, I join with Ritchie and Goulart and Soares to advocate that identity research needs to include participants as co-researchers and co-authors as identities are very personal and complex to be fully understood by the outsiders (researchers).

Upadhyay, Bhaskar

2009-09-01

186

PKM2, STAT3 and HIF-1?: The Warburg's vicious circle.  

PubMed

The M2 isoform of pyruvate kinase, highly expressed in tumor cells, is known to engage a feed forward loop with the glycolysis master transcription factor HIF-1?. Gao and co-authors recently showed that dimeric PKM2 localizes to the nucleus in highly proliferating cancer cells, where it regulates in vivo growth by acting as a protein kinase and directly activating STAT3. STAT3 is therefore a novel player of the PKM2/HIF-1? feedback loop, since HIF-induced PKM2 activates STAT3 that in turn induces HIF-1? expression. These findings have profound implications for understanding the complex connections between gene regulation, metabolism, survival and proliferation in cancer. PMID:24058770

Demaria, Marco; Poli, Valeria

2012-07-01

187

Alexander Hamilton: The Man Who Made Modern America  

NSDL National Science Digital Library

Alexander Hamilton was not only a member of the First Continental Congress but was also a co-author of the Federalist Papers and a vital force behind the ratification of the U.S. Constitution. To honor Hamilton the New York Historical Society has created a special museum exhibit that is due to open in September 2004 at its building in New York City. The actual exhibit is complemented nicely by this online exhibit that offers a timeline of events during (and after) his life, the Hamilton Log which offers highlights from his writings, and a biographical gallery of his peers, such as DeWitt Clinton and Robert Morris. The site is rounded out by a twenty-question quiz that tests visitor's knowledge of Alexander Hamilton and his various accomplishments.

188

Selected literature on water-resources investigations in New Jersey by the U.S. Geological Survey, through 1986  

USGS Publications Warehouse

Because of the importance and complexity of the water resources of New Jersey today, there is a need for a current bibliography to serve as a basis for future water resources studies. This report lists about 400 book reports, map reports, and articles that deal with the water resources of New Jersey published through 1986. The publications are grouped under three major headings: (1) publications of the U.S. Geological Survey, (2) publications of State agencies prepared by or in cooperation with the U.S. Geological Survey, and (3) other publications, such as technical journals prepared by or co-authored by U.S. Geological Survey personnel. Most of the publications are available for inspection at the West Trenton office of the U.S. Geologic Survey and at large public and university libraries. Ordering information is given for those publications that are for sale. (USGS)

compiled by Schaefer, F. L.

1987-01-01

189

Museum of Southwestern Biology: Division of Birds-Publications  

NSDL National Science Digital Library

From the Division of Birds at the University of New Mexico's Museum of Southwestern Biology, this website contains a collection of downloadable publications regarding a number of bird species. The publications are all authored (or co-authored) by Robert W. Dickerman, a Research Associate Professor and Acting Curator for the Division of Birds. Professor Dickerman's articles have appeared in such publications as _Journal of Raptor Research_, _Western Birds_, _Proceedings of the Biological Society of Washington_, _The Southwestern Naturalist_, and _The AUK_ between the years 1991 and 2004. Titles found at this site include "A review of the North American subspecies of the Great Blue Heron (Ardea herodias)," "Talon-Locking in the Red-Tailed Hawk," "An Extinct Subspecies of Sharp-Tailed Grouse," and "On the Validity of Bubo virginianus occidentalis Stone," to name a few.

190

US Environmental Protection Agency Watershed Academy Web: Online Training in Watershed Management  

NSDL National Science Digital Library

The Environmental Protection Agency (EPA)'s Watershed Academy offers training opportunities for ecologists, managers, and others interested in watersheds. Additionally, 20 Academy 2000 Distance Learning Modules are now available online to highlight key watershed management topics. While some modules are under construction, those currently available provide a solid backbone in many important areas such as Principles of Watershed Management, Human Alteration of the Global Nitrogen Cycle, Watershed Modeling, Economics of Sustainability, and Stream Corridor Restoration. Modules vary in depth (and intended audience), but all are (co)-authored by prominent scientists in the field of watershed ecology. Designed to reach a broad audience, many modules are provided in slide format (navigable by clicking on arrows) and could be supplemented with more technical readings; others are given in .pdf format. The inclusion of color photographs throughout, such as in the Ohio's Virtual Watershed Tour module, supplements the learning experience by providing illustrations and examples of important concepts.

191

International experiences in nursing education: a review of the literature.  

PubMed

Service learning and study abroad opportunities have become increasingly popular in nursing education in the past decade. The purpose of this systematic review was to explore existing literature concerning global health experiences in nursing education. Twenty-three empirical articles from 2003 to 2010 were reviewed, building upon existing reviews of international nursing education literature. Research on two-way exchange experiences and models for best practice were found to be lacking. While an array of countries were represented as the visiting or hosting side of the experience, few co-authors from host countries were found, particularly in literature originating from the U.S. The authors recommend that two-way exchange programs be evaluated to identify successful strategies and barriers to success. Ongoing evaluation of exchanges is necessary to ensure continued sustainable partnership and exchange in immersion experiences for nursing students. PMID:22628353

Kulbok, Pamela A; Mitchell, Emma M; Glick, Doris F; Greiner, Doris

2012-04-24

192

Sudden death at the end of the Mesozoic  

USGS Publications Warehouse

A paleoecological analysis of the fossil record before and after the Cretaceous/Tertiary boundary indicates that the widespread extinctions and biological stresses around the boundary are best explained in terms of a sudden, significant, but short temperature rise. L. Alvarez and co-authors, having found an enrichment in iridium at the same boundary, postulated that it was associated with the impact of an extraterrestrial body. If this body struck the ocean, the water injected into the atmosphere may have led to a transient increase in the global surface temperature. This temperature pulse may have been primarily responsible for the effects observed in the biosphere. The pattern of extinction of higher plant species suggests that splash down occurred in the northern Pacific-Bering Sea area. ?? 1981.

Emiliani, C.; Kraus, E. B.; Shoemaker, E. M.

1981-01-01

193

Palm & Cycad Societies of Florida: Virtual Cycad Encyclopedia  

NSDL National Science Digital Library

From the Palm & Cycad Societies of Florida, the Virtual Cycad Encyclopedia is great resource for information and stories about the ancient cycads. The Encyclopedia comprises numerous articles organized under such topics as Cycad Taxonomy, Biology, Evolution, Horticulture, Conservation, and more. Examples of encyclopedia articles include: a 59-frame slide show on Growing and Collecting Cycads; an interactive Key to Cycad Genera; an older article on Pollination Biology of Cycads co-authored by staff at the New York Botanical Garden and the Fairchild Tropical Garden; and a Compiled List of Cycad Genera. The site also contains a Photo Gallery with many good-quality cycad images listed by scientific name. Site visitors will also find a collection of related links, and a list of reference books.

194

1988 DOE model conference proceedings: Volume 3  

SciTech Connect

These Proceedings of the October 3 - 7, 1988, DOE Model Conference are a compilation of the papers that were presented in the technical or poster sessions at the conference. Papers and posters not submitted for publication are not included in the Proceedings. The Table of Contents lists the titles of papers as well as the names of the presenters. These individuals are not, in all cases, the primary authors of the papers published. The actual title pages, appearing later with the papers, show the primary author(s) and all co-authors. The papers in all three volumes of the proceedings appear as they were originally submitted for publication and have not been edited or changed in any way. Topics included in Volume 3 include treatment of soils, waste characterization and certification, waste minimization site remediation management plans and programs, and training programs.

Not Available

1988-01-01

195

The Annotated Grateful Dead Lyrics: a Web Site  

NSDL National Science Digital Library

Forgotten the third verse of "Eyes of the World?" Wondering just what Jerry mumbled after "Eight sided whispering hallelujah hatrack" on your copy of "The Eleven?" from Las Vegas in 1968? Or would you like to know what Robert Hunter meant by the "the transitive nightfall of diamonds?" Look no further than this site, created and maintained by David Dodd, Branch Manager of the Civic Center Branch of the Marin County Free Library, and co-author of The Grateful Dead and the Deadheads: An Annotated Bibliography. Clearly a labor of love, the site offers the full text of songs by Robert Hunter and John Perry Barlow, the Dead's principal lyricists, accompanied by footnotes and possible explanations of various passages by Dodd and others. In addition, the site includes discographies, bibliographies, and thematic essays. Grateful Dead enthusiasts and tape collectors will undoubtedly enjoy this site.

Hunter, Robert.; Barlow, John P. (John Perry).; Garcia, Jerry, 1942-.

196

Leg 124 of the Ocean Drilling Program  

NASA Astrophysics Data System (ADS)

Leg 124 of the Ocean Drilling Program drilled five sites in the Sulu and Celebes Seas (Figure 1). The papers presented in this issue provide an overview of some of the preliminary results of the shipboard science. They represent a team effort, and all are co-authored by the entire scientific party. Our objectives were to determine the age and origin of these basins, and their stratigraphic histories, as indicators of the complex tectonic and paleoceanographic events that have affected the western Pacific region during the Cenozoic. Numerous competing hypotheses have been put forward to explain the array of marginal basins and island arcs in the western Pacific, and these basins are all potential recorders of the complex history of the western Pacific history.

Silver, Eli A.; Rangin, Claude

197

FROM THE HISTORY OF PHYSICS: George Gamow: World line 1904-1933 (On the ninetieth anniversary of G A Gamov's birth)  

NASA Astrophysics Data System (ADS)

One of his articles written with a co-author Gamov called 'My half-article'. Here his 'half-biography' is presented. It covers the first very important part of his life, starting from his youth in Odessa, his student years in Petrograd-Leningrad and several of his visits to Germany, Denmark, and England in connection with his scientific work. Special attention is devoted to his first scientific researches (1926-1928) at the Leningrad State University and to his relations with fellow students—M P Bronstein, D D Ivanenko, and L D Landau. His research into ?-decay—its genesis and subsequent fate—is analysed. This article is in many respects based on new archive material.

Frenkel', Viktor Ya

1994-08-01

198

The Initial Nine Space Settlements  

NASA Astrophysics Data System (ADS)

The co-authors describe a chronology of space infrastructure development illustrating how each element of infrastructure enables development of subsequent more ambitious infrastructure. This is likened to the ``Southern California freeway phenomenon'', wherein a new freeway built in a remote area promotes establishment of gas stations, restaurants, hotels, housing, and eventually entire new communities. The chronology includes new launch vehicles, inter-orbit vehicles, multiple LEO space stations, lunar mining, on-orbit manufacturing, tourist destinations, and supporting technologies required to make it all happen. The space settlements encompassed by the chronology are in Earth orbit (L5 and L4), on the lunar surface, in Mars orbit, on the Martian surface, and in the asteroid belt. Each space settlement is justified with a business rationale for construction. This paper is based on materials developed for Space Settlement Design Competitions that enable high school students to experience the technical and management challenges of working on an industry proposal team.

Gale, Anita E.; Edwards, Richard P.

2003-01-01

199

A consensus statement for safety monitoring guidelines of treatments for major depressive disorder  

PubMed Central

Objective This paper aims to present an overview of screening and safety considerations for the treatment of clinical depressive disorders and make recommendations for safety monitoring. Method Data were sourced by a literature search using MEDLINE and a manual search of scientific journals to identify relevant articles. Draft guidelines were prepared and serially revised in an iterative manner until all co-authors gave final approval of content. Results Screening and monitoring can detect medical causes of depression. Specific adverse effects associated with antidepressant treatments may be reduced or identified earlier by baseline screening and agent-specific monitoring after commencing treatment. Conclusion The adoption of safety monitoring guidelines when treating clinical depression is likely to improve overall physical health status and treatment outcome. It is important to implement these guidelines in the routine management of clinical depression.

Dodd, Seetal; Malhi, Gin S; Tiller, John; Schweitzer, Isaac; Hickie, Ian; Khoo, Jon Paul; Bassett, Darryl L; Lyndon, Bill; Mitchell, Philip B; Parker, Gordon; Fitzgerald, Paul B; Udina, Marc; Singh, Ajeet; Moylan, Steven; Giorlando, Francesco; Doughty, Carolyn; Davey, Christopher G; Theodoras, Michael; Berk, Michael

2011-01-01

200

Fabrication of Si nanowires on Si (100) using a scanning probe tip  

NASA Astrophysics Data System (ADS)

Reliable fabrication on the nanoscale is becoming increasingly important. The co-author team is investigating a nanolithography technique for the deposition of nanoscale features entitled ``Tip-directed, field-emission assisted nanomanufacturing'' (TFAN). The TFAN process involves the adsorption of a layer of silicon-containing gas, such as disilane, to a substrate and the selective patterning of the surface with field-emitted electrons from a scanning probe tip. The electrons crack the Si containing molecules, which results in the deposition of Si on the substrate. The adsorption of the Si-containing molecules to the substrate surface is critical to the success of this approach. The investigation involves the determination of the coverage, sticking coefficient, and time constant of disilane on the Si(100) surface using temperature programmed desorption and scanning tunneling microscopy.

Smith, Joshua; Davis, Robert; Dang, Ying Yi; Fedder, Gary; Bain, Jim; Ricketts, David

2009-03-01

201

Manuscript Architect: a Web application for scientific writing in virtual interdisciplinary groups  

PubMed Central

Background Although scientific writing plays a central role in the communication of clinical research findings and consumes a significant amount of time from clinical researchers, few Web applications have been designed to systematically improve the writing process. This application had as its main objective the separation of the multiple tasks associated with scientific writing into smaller components. It was also aimed at providing a mechanism where sections of the manuscript (text blocks) could be assigned to different specialists. Manuscript Architect was built using Java language in conjunction with the classic lifecycle development method. The interface was designed for simplicity and economy of movements. Manuscripts are divided into multiple text blocks that can be assigned to different co-authors by the first author. Each text block contains notes to guide co-authors regarding the central focus of each text block, previous examples, and an additional field for translation when the initial text is written in a language different from the one used by the target journal. Usability was evaluated using formal usability tests and field observations. Results The application presented excellent usability and integration with the regular writing habits of experienced researchers. Workshops were developed to train novice researchers, presenting an accelerated learning curve. The application has been used in over 20 different scientific articles and grant proposals. Conclusion The current version of Manuscript Architect has proven to be very useful in the writing of multiple scientific texts, suggesting that virtual writing by interdisciplinary groups is an effective manner of scientific writing when interdisciplinary work is required.

Pietrobon, Ricardo; Nielsen, Karen C; Steele, Susan M; Menezes, Andreia P; Martins, Henrique; Jacobs, Danny O

2005-01-01

202

Bridging the gap between data acquisition and inference ontologies: toward ontology-based link discovery  

NASA Astrophysics Data System (ADS)

Bridging the gap between low level ontologies used for data acquisition and high level ontologies used for inference is essential to enable the discovery of high-level links between low-level entities. This is of utmost importance in many applications, where the semantic distance between the observable evidence and the target relations is large. Examples of these applications would be detection of terrorist activity, crime analysis, and technology monitoring, among others. Currently this inference gap has been filled by expert knowledge. However, with the increase of the data and system size, it has become too costly to perform such manual inference. This paper proposes a semi-automatic system to bridge the inference gap using network correlation methods, similar to Bayesian Belief Networks, combined with hierarchical clustering, to group and organize data so that experts can observe and build the inference gap ontologies quickly and efficiently, decreasing the cost of this labor-intensive process. A simple application of this method is shown here, where the co-author collaboration structure ontology is inferred from the analysis of a collection of journal publications on the subject of anthrax. This example uncovers a co-author collaboration structures (a well defined ontology) from a scientific publication dataset (also a well defined ontology). Nevertheless, the evidence of author collaboration is poorly defined, requiring the use of evidence from keywords, citations, publication dates, and paper co-authorship. The proposed system automatically suggests candidate collaboration group patterns for evaluation by experts. Using an intuitive graphic user interface, these experts identify, confirm and refine the proposed ontologies and add them to the ontology database to be used in subsequent processes.

Goldstein, Michel L.; Morris, Steven A.; Yen, Gary G.

2003-09-01

203

Results from PIXON-Processed HRC Images of Pluto  

NASA Astrophysics Data System (ADS)

We examine the 384 dithered images of Pluto and Charon taken with the Hubble Space Telescope's High Resolution Camera (HRC) under program GO-9391. We have deconvolved the individual images with synthetic point spread functions (PSF) generated with TinyTim v6.3 using PIXON processing (Puetter and Yahil 1999). We reconstruct a surface albedo map of Pluto using a backprojection algorithm. At present, this algorithm does not include Hapke phase function or backscattering parameters. We compare this albedo map to earlier maps based on HST and mutual event observations (e.g., Stern et al. 1997, Young et al. 2001), looking for changes in albedo distribution and B-V color distribution. Pluto's volatile surface ices are closely tied to its atmospheric column abundance, which has doubled in the interval between 1989 and 2002 (Sicardy et al. 2003, Elliot et al. 2003). A slight rise (1.5 K) in the temperature of nitrogen ice would support the thicker atmosphere. We examine the albedo distribution in the context of Pluto's changing atmosphere. Finally, a side effect of the PIXON processing is that we are better able to search for additional satellites in the Pluto-Charon system. We find no satellites within a 12 arcsec radius of Pluto brighter than a 5-sigma upper limit of B=25.9. In between Pluto and Charon this upper limit is degraded to B=22.8 within one Rp of Pluto's surface, improving to B=25.1 at 10 Rp (Charon's semimajor axis). This research was supported by a grant from NASA's Planetary Astronomy Program (NAG5-12516) and STScI grant GO-9391. Elliot, J.L., and 28 co-authors (2003), ``The recent expansion of Pluto's atmosphere," Nature 424, 165-168. R. C. Puetter and A. Yahil (1999), ``The Pixon Method of Image Reconstruction" in Astronomical Data Analysis Software and Systems VIII, D. M. Mehringer, R. L. Plante & D. A. Roberts, eds., ASP Conference Series, 172, pp. 307-316. Sicardy, B. and 40 co-authors (2003), ``Large changes in Pluto's atmosphere as revealed by recent stellar occultations," Nature 424, 168-170. Stern, S.A., Buie, M.W., and Trafton, L.M. (1997), ``HST High-Resolution Images and Maps of Pluto," AJ 113, 827. Young, E.F., Binzel, R.P., and Crane, K. (2001), ``A Two-Color Map of Pluto's Sub-Charon Hemisphere," AJ 121, 552.

Young, E. F.; Buie, M. W.; Young, L. A.

2005-08-01

204

Pullback attractors in nonautonomous dynamical systems with delay: Applications to an ENSO model with seasonal forcing  

NASA Astrophysics Data System (ADS)

Recent work by two of the co-authors (MDC and MG) on random dynamical systems and their attractors has motivated us to consider also a closely related problem, namely the pullback attractors (PBAs) of deterministic dynamical systems driven by time-dependent forcing. Two obvious examples of such forcing in climate dynamics are: (i) periodic forcing by the seasonal cycle; and (ii) slow forcing by an interdecadal warming trend. We illustrate these two types of forcing in a highly idealized model for El Nino/Southern Oscillation (ENSO) variability, previously studied by two of the co-authors (MG and IZ). The model is governed by a delay differential equation (DDE) for sea surface temperature T in the Tropical Pacific, and it combines two key mechanisms that participate in ENSO dynamics: delayed negative feedback and seasonal forcing. We perform a theoretical and numerical study of the model in the three-dimensional space of its physically relevant parameters: strength of seasonal forcing, atmosphere-ocean coupling, and propagation period of oceanic waves across the Tropical Pacific. We report several findings that are consistent with the observed dynamics of ENSO, as well as with more detailed and realistic models: quasi-periodic behavior with the correct "period" values, phase locking, and sensitive dependence on model parameters. We demonstrate, furthermore, that the transition from smooth period-1 behavior to more realistic --- quasi-periodic or chaotic --- behavior occurs in a sequence of bifurcations similar to those observed in classical chaotic systems. We study next a multi-dimensional manifold of solutions, given by constant or piecewise constant initial histories, e.g. a constant, year-long warm (El Nino) or cold (La Nina) state. To do so, we apply the PBA concept in order to study the model dynamics in the model-parameter region where sensitivity to parameter values is high, as well as in the transition region from smooth to sensitive behavior. Computation of the model's PBAs clearly demonstrates that its dynamics --- whether periodic (smooth) or quasi-periodic (sensitive) --- occurs on a two-dimensional torus. This behavior reflects the competition between two oscillatory mechanisms: an external one due to the seasonal forcing and an internal one due to the delayed feedbacks. Such an interpretation is much harder to obtain from the complex, parameter-sensitive dynamics of the model using more traditional approaches for autonomous systems. Finally, we study the model dynamics subject to long-tem global warming scenarios and interpret the results in the context of the ongoing research on long-term climate projections.

Chekroun, Mickaël.; Zaliapin, Ilya; Ghil, Michael

2010-05-01

205

Towards the determination of the equation of state of hydrogen and helium at extreme densities: Laser induced shocks on pre-compressed samples.  

NASA Astrophysics Data System (ADS)

The determination of the equation of state of helium and hydrogen at very high density is an important problem at the frontier between condensed matter physics and plasma physics. It is also an important issue in planetary physics for understanding the formation of giant and extrasolar planets. However, the extreme densities relevant to most of the interior of Jupiter are unreachable by either static or single-shock compression techniques alone. Recently, a laser-driven shock-wave in a hydrogen sample, pre-compressed in a diamond anvil cell, has been demonstrated [1]. Consequently, the compression factors of the dynamic and static techniques can now be multiplied. We will present our current effort with the Omega laser at LLE to measure accurately the Hugoniot curves of hydrogen and helium pre-compressed up to 1.5 GPa. The metrology and error bars of the measurements will be discussed. The Hugoniot data points will be compared to published calculations, and an interesting difference in the insulator-metal transition of hydrogen and helium will be discussed. Co-authors are Stephanie Brygoo, CEA, France; Jon Eggert, Peter Celliers, Guilbert Collins, LLNL, Livermore CA 94551 USA; Ryan McWilliam, Raymond Jeanloz, University of California, CA 94720 USA; and Tom Boehly, LLE, New-York 14623 USA. [1] P. Loubeyre et al., High Pressure Research 24, 25- 31 (2004).

Loubeyre, Paul

2005-03-01

206

Optimization of ultra-fast interactions using laser pulse temporal shaping controlled by a deterministic algorithm  

NASA Astrophysics Data System (ADS)

Femtosecond laser pulse temporal shaping techniques have led to important advances in different research fields like photochemistry, laser physics, non-linear optics, biology, or materials processing. This success is partly related to the use of optimal control algorithms. Due to the high dimensionality of the solution and control spaces, evolutionary algorithms are extensively applied and, among them, genetic ones have reached the status of a standard adaptive strategy. Still, their use is normally accompanied by a reduction of the problem complexity by different modalities of parameterization of the spectral phase. Exploiting Rabitz and co-authors' ideas about the topology of quantum landscapes, in this work we analyze the optimization of two different problems under a deterministic approach, using a multiple one-dimensional search (MODS) algorithm. In the first case we explore the determination of the optimal phase mask required for generating arbitrary temporal pulse shapes and compare the performance of the MODS algorithm to the standard iterative Gerchberg-Saxton algorithm. Based on the good performance achieved, the same method has been applied for optimizing two-photon absorption starting from temporally broadened laser pulses, or from laser pulses temporally and spectrally distorted by non-linear absorption in air, obtaining similarly good results which confirm the validity of the deterministic search approach.

Galvan-Sosa, M.; Portilla, J.; Hernandez-Rueda, J.; Siegel, J.; Moreno, L.; Ruiz de la Cruz, A.; Solis, J.

2013-04-01

207

Comment on "A Comparison of Buprenorphine + Naloxone to Buprenorphine and Methadone in the Treatment of Opioid Dependence During Pregnancy: Maternal and Neonatal Outcomes"  

PubMed Central

In a recent article, Lund et al sought to compare maternal and neonatal outcomes of various treatment regimens for opioid dependence during pregnancy.1 In their background, discussion the authors state that “In the United States buprenorphine plus naloxone [Suboxone®] … has been the preferred form of prescribed buprenorphine due to its reduced abuse liability relative to buprenorphine alone [Subutex®].” This claim is certainly consistent with the view of the firm that has manufactured and sold both products, Reckitt Benckiser. In September of 2011, the company announced that it was “… discontinuing distribution and sale of Subutex® tablets as we believe that mono product (product containing buprenorphine alone with no naloxone) creates a greater risk of misuse, abuse and diversion …”.2 Supporting evidence for the alleged “reduced abuse liability” appears to be lacking, however, and evidence cannot be located in the two references cited by Dr. Lund and his co-authors, which in fact are silent on the subject of abuse potential.3,4 In contrast, it has been reported that the transition to buprenorphine/naloxone from the mono formulation has been associated with “… no reduction in injection risk behaviors among IDUs.”5

Newman, Robert G.; Gevertz, Susan G.

2013-01-01

208

Comment on "a comparison of buprenorphine + naloxone to buprenorphine and methadone in the treatment of opioid dependence during pregnancy: maternal and neonatal outcomes".  

PubMed

In a recent article, Lund et al sought to compare maternal and neonatal outcomes of various treatment regimens for opioid dependence during pregnancy.1 In their background, discussion the authors state that "In the United States buprenorphine plus naloxone [Suboxone(®)] … has been the preferred form of prescribed buprenorphine due to its reduced abuse liability relative to buprenorphine alone [Subutex(®)]." This claim is certainly consistent with the view of the firm that has manufactured and sold both products, Reckitt Benckiser. In September of 2011, the company announced that it was "… discontinuing distribution and sale of Subutex(®) tablets as we believe that mono product (product containing buprenorphine alone with no naloxone) creates a greater risk of misuse, abuse and diversion …".2 Supporting evidence for the alleged "reduced abuse liability" appears to be lacking, however, and evidence cannot be located in the two references cited by Dr. Lund and his co-authors, which in fact are silent on the subject of abuse potential.3,4 In contrast, it has been reported that the transition to buprenorphine/naloxone from the mono formulation has been associated with "… no reduction in injection risk behaviors among IDUs."5. PMID:23772177

Newman, Robert G; Gevertz, Susan G

2013-05-26

209

Lectures of Fermi liquid theory  

SciTech Connect

The Fermi liquid theory was first introduced by Landau in 1956 to provide a theoretical basis for the properties of strongly correlated Fermi systems. This theory has proven to be crucial for our understanding of a broad range of materials. These include liquid [sup 3]He, [sup 3]He-[sup 4]He mixtures, simple metals, heavy-fermions, and nuclear matter to name a few. In the high temperature superconductors questions have been raised regarding the applicability of Fermi liquid theory to the normal state behavior of these materials. I will not address this issue in these lectures. My focus will be to summarize the foundations of this theory and to explore the consequences. These lectures are in part a summary of the excellent review article by Baym and Pethick and the books by Pines and Nozieres and Baym and Pethick. They include as well a summary of some articles that I have authored and co-authored. In the main body of the lectures I will not make any additional references to the books or articles. In the absence of reading the original materials, my lectures should provide the essentials of a mini-course in Fermi liquid theory.

Bedell, K.S.

1993-01-01

210

Lectures of Fermi liquid theory  

SciTech Connect

The Fermi liquid theory was first introduced by Landau in 1956 to provide a theoretical basis for the properties of strongly correlated Fermi systems. This theory has proven to be crucial for our understanding of a broad range of materials. These include liquid {sup 3}He, {sup 3}He-{sup 4}He mixtures, simple metals, heavy-fermions, and nuclear matter to name a few. In the high temperature superconductors questions have been raised regarding the applicability of Fermi liquid theory to the normal state behavior of these materials. I will not address this issue in these lectures. My focus will be to summarize the foundations of this theory and to explore the consequences. These lectures are in part a summary of the excellent review article by Baym and Pethick and the books by Pines and Nozieres and Baym and Pethick. They include as well a summary of some articles that I have authored and co-authored. In the main body of the lectures I will not make any additional references to the books or articles. In the absence of reading the original materials, my lectures should provide the essentials of a mini-course in Fermi liquid theory.

Bedell, K.S.

1993-07-01

211

The effects of downwelling radiance on MER surface spectra: the evil that atmospheres do  

NASA Astrophysics Data System (ADS)

While it may not be surprising to some that downwelling radiation in the martian atmosphere may contribute a non-negligible fraction of the radiance for a given surface scene, others remain shocked and surprised (and often dismayed) to discover this fact; particularly with regard to mini-TES observations. Naturally, the relative amplitude of this sky ``contamination'' is often a complicated function of meteorological conditions, viewing geometry, surface properties, and (for the IR) surface temperature. Ideally, one would use a specialized observations to mimic the actual hemispherical-directional nature of the problem. Despite repeated attempts to obtain Pancam complete sky observations and mini-TES sky octants, such observations are not available in the MER observational database. As a result, one is left with the less-enviable, though certainly more computationally intensive, task of connecting point observations (radiance and derived meteorological parameters) to a hemispherical integral of downwelling radiance. Naturally, one must turn to a radiative transfer analysis, despite oft-repeated attempts to assert otherwise. In our presentation, we offer insight into the conditions under which one must worry about atmospheric removal, as well as semi-empirical approaches (based upon said radiative transfer efforts) for producing the correction factors from the available MER atmospheric observations. This work is proudly supported by the MER program through NASA/JPL Contract No. 1242889 (MJW), as well as the contracts for the co-authors.

Wolff, M.; Ghosh, A.; Arvidson, R.; Christensen, P.; Guinness, E.; Ruff, S.; Seelos, F.; Smith, M.; Athena Science

2004-11-01

212

Poisoned social climate, collective responsibility, and the abuse at Abu Ghraib--Or, the establishment of "rule that is lack of rule".  

PubMed

The authors draw upon the experiences of one of the co-authors as an expert witness in sociology for mitigation at three of the courts-martial pertaining to the abuse at Abu Ghraib that were held at Ft. Hood, Texas in the year 2005 (for Javal Davis, Sabrina Harman, and Lynndie England). In addition, this paper is based upon the thousands of pages of affidavits, testimony, and U.S. Government reports concerning Abu Ghraib. These internal government reports, as well as the Levin-McCain report, point to collective responsibility and the responsibility of individuals high in the chain of command for establishing unlawful techniques. We review the shortcomings of a purely psychological approach for understanding the abuse, and turn to Durkheim's original understanding of anomie as a state of social derangement or rule by lack of rule to introduce the ideas of the social origins of and social responsibility for the abuse. We conclude with sociological suggestions for reforming some of the legal, medical, psychiatric, and other professional complicity in the abuse at Abu Ghraib. PMID:22153587

Mestrovic, Stjepan G; Romero, Rachel

2011-12-05

213

The best medicine. Interview by Jim Montague.  

PubMed

Laughter can be crucial to patient care, but physician and clown Patch Adams, M.D., sees nothing funny about the greed he finds in the nation's health care system and in current reform plans. Adams has spent almost 25 years infusing practitioners with a sense of humor. This philosophy extends into his work as founder of the not-for-profit Gesundheit Institute, which is trying to build an "ultimate fantasy" hospital on 310 acres in rural West Virginia. So far, he's raised $1.1 million, built one of three main buildings, and broken ground on a second. However, millions of dollars still need to be raised. Adams sees the very notion of his dream hospital as a necessary pie in the face of the traditional health care system. Besides speaking and performing, Adams takes groups of clowns to Russia, where they perform in hospitals, orphanages, prisons and on the street. Adams has co-authored a book about his philosophies, Gesundheit, and sold the rights to a Hollywood studio. He spoke recently with staff editor Jim Montague. PMID:8025607

Adams, P

1994-07-20

214

On branching streamers and sprites: channel head dynamics in laboratory and high atmosphere  

NASA Astrophysics Data System (ADS)

Streamers are weakly ionized channels appearing in the initial electric breakdown of long gaps; they form corona discharges and play a role in sparks and lightning. Their growth and branching is determined at their rapidly propagating heads where the electric field is strongly enhanced due to dynamical self-focussing; this creates exotic nonequilibrium plasma in the heads. Streamer-like processes also occur in gigantic high altitude lightning when sprite discharges at heights of 40 to 90 km break up into tenthousands of propagating channels. I will review recent observations and then elaborate computations and theoretical concepts. Basically, already a single discharge channel has a multiscale structure with a thin ionization front surrounding a rather inert body. This structure has been observed in computations in the past decades, but it was recognized only recently that this structure also leads to spontaneous branching. The mechanism is a Laplacian instability that can occur similarly at other phase boundaries like liquid-fluid interfaces, solidification fronts etc. I will present computational results with adaptive grids and analytical approximations and solutions; and I will confront the new concepts with older phenomenological concepts for streamer and spark propagation and branching. For papers and co-authors, see http://homepages.cwi.nl/ ebert

Ebert, Ute

2004-09-01

215

Accelerated and Adaptive Evolution of Yeast Sexual Adhesins  

PubMed Central

There is a recent emergence of interest in the genes involved in gametic recognition as drivers of reproductive isolation. The recent population genomic sequencing of two species of sexually primitive yeasts (Liti G, Carter DM, Moses AM, Warringer J, Parts L, James SA, Davey RP, Roberts IN, Burt A, Koufopanou V et al. [23 co-authors]. 2009. Population genomics of domestic and wild yeasts. Nature 458:337–341.) has provided data for systematic study of the roles these genes play in the early evolution of sex and speciation. Here, we discovered that among genes encoding cell surface proteins, the sexual adhesin genes have evolved significantly more rapidly than others, both within and between Saccharomyces cerevisiae and its closest relative S. paradoxus. This result was supported by analyses using the PAML pairwise model, a modified McDonald–Kreitman test, and the PAML branch model. Moreover, using a combination of a new statistic of neutrality, an information theory–based measure of evolutionary variability, and functional characterization of amino acid changes, we found that a higher proportion of amino acid changes are fixed in the sexual adhesins than in other proteins and a greater proportion of the fixed amino acid changes either between the two species or the two subgroups of S. paradoxus are functionally dissimilar or radically different. These results suggest that the accelerated evolution of sexual adhesin genes may facilitate speciation, or incipient speciation, and promote sexual selection in general.

Xie, Xianfa; Qiu, Wei-Gang; Lipke, Peter N.

2011-01-01

216

Analysis of Data from the Energetic Gamma-ray Experiment on the Gamma Ray Observatory  

NASA Astrophysics Data System (ADS)

The work under the Grant has involved participation with the Compton Gamma Ray Observatory Energetic Gamma-Ray Experiment Telescope (EGRET) Team in the analysis of data obtained during instrument operations and the preparation of scientific papers and proposals for future observations. The Principal Investigator (PI) has been a co-author on a total of 90 papers published in refereed professional journals since the beginning of 1991, plus many other non-refereed publications, and contributed and invited papers at professional meetings and IAU telegrams. On seven of these papers he was the lead author. The EGRET team continues to submit IAU Astronomical telegrams and present many papers at scientific meetings. The effort by the PI has involved working remotely by internet connection on the Goddard Space Flight Center Computers where the EGRET data are archived. Students have monitored instrument performance, performed Viewing Period Analyses and analyzed data remotely. The PI has completed the detailed analysis of over 20 viewing periods to search for point sources and this work has been used in developing the first and second EGRET catalog of sources, published in Supplements to the Astrophysical Journal.

Kniffen, Donald A.

1996-08-01

217

Accelerated and adaptive evolution of yeast sexual adhesins.  

PubMed

There is a recent emergence of interest in the genes involved in gametic recognition as drivers of reproductive isolation. The recent population genomic sequencing of two species of sexually primitive yeasts (Liti G, Carter DM, Moses AM, Warringer J, Parts L, James SA, Davey RP, Roberts IN, Burt A, Koufopanou V et al. [23 co-authors]. 2009. Population genomics of domestic and wild yeasts. Nature 458:337-341.) has provided data for systematic study of the roles these genes play in the early evolution of sex and speciation. Here, we discovered that among genes encoding cell surface proteins, the sexual adhesin genes have evolved significantly more rapidly than others, both within and between Saccharomyces cerevisiae and its closest relative S. paradoxus. This result was supported by analyses using the PAML pairwise model, a modified McDonald-Kreitman test, and the PAML branch model. Moreover, using a combination of a new statistic of neutrality, an information theory-based measure of evolutionary variability, and functional characterization of amino acid changes, we found that a higher proportion of amino acid changes are fixed in the sexual adhesins than in other proteins and a greater proportion of the fixed amino acid changes either between the two species or the two subgroups of S. paradoxus are functionally dissimilar or radically different. These results suggest that the accelerated evolution of sexual adhesin genes may facilitate speciation, or incipient speciation, and promote sexual selection in general. PMID:21633112

Xie, Xianfa; Qiu, Wei-Gang; Lipke, Peter N

2011-06-01

218

E-portfolios and personalized learning: research in practice with two dyslexic learners in UK higher education.  

PubMed

This paper analyses the use of an e-portfolio system in contributing to the personalized learning of two dyslexic learners at the University of Wolverhampton, UK. The rationale for this research rests at the intersection of generic findings from e-portfolio (and wider e-learning) research and the still challenging project in higher education (HE) of creating inclusive curricula. A qualitative, ethnographic approach was employed in a piece of collaborative research between academic staff and dyslexic learners. Two retrospective learner narratives were constructed and then reviewed by all co-authors in terms of the 'personalized fit' which they allowed with dyslexic thinking, learning and writing experience. The findings suggest a potential refinement of the general pedagogical claims about e-portfolio-based learning when considering dyslexic learners and thence the value of an enhanced prioritization of e-portfolio learning practices within inclusive HE curricula. The review and analysis also allow a 'critical' discussion of the practical and theoretical issues arising within this work. PMID:20865707

Hughes, Julie; Herrington, Margaret; McDonald, Tess; Rhodes, Amy

2010-09-22

219

Research and Education in Physics and Astronomy at Haverford College  

NASA Astrophysics Data System (ADS)

This talk focuses on special features of research and education in physics and astronomy at Haverford. These include: (a) The involvement of students in research for many decades, both locally and at national facilities. At least 60 students have been co-authors of scientific papers in the last 30 years, of which many contain significant new science. (b) A noteworthy Astronomy program that has produced a surprising number of active astronomers, many of whom have been recognized by national awards. (c) A physics senior seminar that helps students to make the transition from an undergraduate education to the world of graduate education or work. (d) A network of interdisciplinary interactions and concentrations that enables the physics program to appeal to students with broad interests, e.g. in biology, computer science, education, or engineering. (e) A tradition of outreach courses to students not majoring in science. (f) Curricular coordination with neighboring Bryn Mawr College. (g) Notable laboratory courses that prepare students for research and independent learning. )

Gollub, Jerry

2010-02-01

220

Solar and Fusion Plasmas  

SciTech Connect

The poster describes work I have published with co-authors in theoretical and experimental studies of plasmas: both in the laboratory, with relevance to magnetically confined fusion, and naturally occurring, in the Sun's atmosphere (the corona). In the case of fusion plasmas, recent work on recombining plasmas in a linear plasma device, the ULS, is described, which develops understanding of the processes by which detachment is obtained in a tokamak divertor. Results of experimental studies of recombining plasmas are presented, interpreted through 1D plasma models and collisional-radiative models. In the case of the solar corona, we discuss coronal heating by magnetic reconnection. The question of how the solar corona is heated to temperatures of millions of degrees is a major outstanding problem in astrophysics. Some recent results of numerical simulation of forced magnetic reconnection are presented, focusing on the energy release, and we describe how relaxation theory can be used to calculate heating by multiple reconnection events. The presence of high-energy charged particles is an important diagnostic of magnetic reconnection, and models of particle acceleration by reconnecting fields are also presented.

Browning, Philippa [School of Physics and Astronomy, University of Manchester (United Kingdom)

2005-10-17

221

2009 AMCA Memorial Lecture Honoree: Dr. Chester Lamar Meek.  

PubMed

Chester Lamar Meek (1944-2000), 2009 AMCA Memorial Lecture Honoree, was husband to Sharon Kay Meek, father of Bradley Lamar and Jody Keith, and a member of the faculty of Louisiana State University for 25 years when he passed away on June 27, 2000, while conducting field research on mosquitoes in Cleveland, Mississippi. Dr. Meek was born in Monticello, Arkansas, and attended Ouachita Baptist University, University of Arkansas, and Texas A&M University, where he took his B.S., M.S., and Ph.D., respectively. He was an expert in the biology and control of rice-field mosquitoes and in forensic entomology. He served in the medical service corps of the US Army, authored or co-authored over 65 scientific publications, and was mentor to graduate students in medical and forensic entomology. Dr. Meek was a member of the Louisiana Mosquito Control Association, the Texas Mosquito Control Association, the American Mosquito Control Association, the Entomological Society of America, the American Registry of Professional Entomologists, and the Society for Vector Ecology. He received the American Mosquito Control Association's awards for Meritorious Service (1986) and the Memorial Lectureship Award (1991) and was recognized for his service by the Louisiana Mosquito Control Association with the 1989 Hathaway-Ritter Distinguished Achievement award. PMID:19852210

Connelly, C Roxanne

2009-09-01

222

Improved Phylogenomic Taxon Sampling Noticeably Affects Nonbilaterian Relationships  

PubMed Central

Despite expanding data sets and advances in phylogenomic methods, deep-level metazoan relationships remain highly controversial. Recent phylogenomic analyses depart from classical concepts in recovering ctenophores as the earliest branching metazoan taxon and propose a sister-group relationship between sponges and cnidarians (e.g., Dunn CW, Hejnol A, Matus DQ, et al. (18 co-authors). 2008. Broad phylogenomic sampling improves resolution of the animal tree of life. Nature 452:745–749). Here, we argue that these results are artifacts stemming from insufficient taxon sampling and long-branch attraction (LBA). By increasing taxon sampling from previously unsampled nonbilaterians and using an identical gene set to that reported by Dunn et al., we recover monophyletic Porifera as the sister group to all other Metazoa. This suggests that the basal position of the fast-evolving Ctenophora proposed by Dunn et al. was due to LBA and that broad taxon sampling is of fundamental importance to metazoan phylogenomic analyses. Additionally, saturation in the Dunn et al. character set is comparatively high, possibly contributing to the poor support for some nonbilaterian nodes.

Pick, K.S.; Philippe, H.; Schreiber, F.; Erpenbeck, D.; Jackson, D.J.; Wrede, P.; Wiens, M.; Alie, A.; Morgenstern, B.; Manuel, M.; Worheide, G.

2010-01-01

223

Recent Advances In Structural Vibration And Failure Mode Control In Mainland China: Theory, Experiments And Applications  

NASA Astrophysics Data System (ADS)

A number of researchers have been focused on structural vibration control in the past three decades over the world and fruit achievements have been made. This paper introduces the recent advances in structural vibration control including passive, active and semiactive control in mainland China. Additionally, the co-author extends the structural vibration control to failure mode control. The research on the failure mode control is also involved in this paper. For passive control, this paper introduces full scale tests of buckling-restrained braces conducted to investigate the performance of the dampers and the second-editor of the Code of Seismic Design for Buildings. For active control, this paper introduces the HMD system for wind-induced vibration control of the Guangzhou TV tower. For semiactive control, the smart damping devices, algorithms for semi-active control, design methods and applications of semi-active control for structures are introduced in this paper. The failure mode control for bridges is also introduced.

Li, Hui; Ou, Jinping

2008-07-01

224

Asymmetric tensor field visualization for surfaces.  

PubMed

Asymmetric tensor field visualization can provide important insight into fluid flows and solid deformations. Existing techniques for asymmetric tensor fields focus on the analysis, and simply use evenly-spaced hyperstreamlines on surfaces following eigenvectors and dual-eigenvectors in the tensor field. In this paper, we describe a hybrid visualization technique in which hyperstreamlines and elliptical glyphs are used in real and complex domains, respectively. This enables a more faithful representation of flow behaviors inside complex domains. In addition, we encode tensor magnitude, an important quantity in tensor field analysis, using the density of hyperstreamlines and sizes of glyphs. This allows colors to be used to encode other important tensor quantities. To facilitate quick visual exploration of the data from different viewpoints and at different resolutions, we employ an efficient image-space approach in which hyperstreamlines and glyphs are generated quickly in the image plane. The combination of these techniques leads to an efficient tensor field visualization system for domain scientists. We demonstrate the effectiveness of our visualization technique through applications to complex simulated engine fluid flow and earthquake deformation data. Feedback from domain expert scientists, who are also co-authors, is provided. PMID:22034315

Chen, Guoning; Palke, Darrel; Zhongzang, Lin; Yeh, Harry; Vincent, Paul; Laramee, Robert S; Zhang, Eugene

2011-12-01

225

Gas Phase Diagnostics in LAPPS  

NASA Astrophysics Data System (ADS)

NRL is developing a scalable Large Area Plasma Processing System for materials processing applications.^a Using a magnetically collimated sheet of high energy electrons (2-5kV, 10 mA/cm^2) to ionize a neutral background gas, a high density plasma of comparable size with cold electrons and ions is produced independent of chamber configuration. This beam ionization process is readily scalable (to meters^2) with the limiting factor being the range of the electron beam in the background gas ( ~ 10 eV/cm). Presently, operating pressures range from 10-500 mtorr with 0-300 Gauss magnetic fields, using a hollow cathode as an electron beam source. Temporally and spatially resolved data from Langmuir probes, optical emission, microwave absorption/transmission and electron beam analysis of the plasma sheet in recent pulsed operation studies (10-1000 ?s pulse length, < 10 kHz pulse repetition frequency) will be presented for various gas mixtures. Ion densities from 10^9 to 5x10^12 cm-3 are obtained in plasma volumes of 1x30x30cm^3 in mixtures of oxygen, nitrogen, argon and neon. Overviews and additional details of the LAPPS process will be presented by co-authors.footnote See presentations by R. A. Meger, R. F. Fernsler, S. G. Walton and D. P. Murphy at this conference.

Leonhardt, D.; Walton, S. G.; Murphy, D. P.; Amatucci, W. E.; Meger, R. A.; Fernsler, R. F.

1999-10-01

226

Electron acceleration by laser fields in a gas. Final report  

SciTech Connect

The purpose of the project is an investigation of topics related to the high-energy acceleration of electrons by means of suitably shaped laser beams in an inert gaseous medium. By slowing down the phase velocity of the fields by its index of refraction, the gas allows a cumulative interaction with the electrons resulting in net acceleration and also focusing. The objectives of the work reported here were twofold: (1) to participate as a consultant in the design and analysis of demonstration experiments performed at the Brookhaven National Laboratory by STI Optronics, a Belleview, WA company, under a separate DOE funded contract; (2) to perform further analytic and design work on the laser acceleration scheme originally proposed and explore a possible extension of the method to acceleration in vacuum using the same field configuration and analogous interaction process as with a gas. This report thus comprises an account of both activities. Section 2 is an overview of the various laser acceleration methods that have been proposed, in order to provide a framework to the work reported. Section 3 contains a list of meetings attended by the Principal Investigator to present his work and interact with research community colleagues and STI staff, and a list of publications containing work he co-authored or was acknowledged for. Section 4 summarizes the work performed by STI to which he contributed. Section 5 consists of the technical reports the Principal Investigator wrote describing his independent theoretical work elaborating and extending the scope of the original project.

Fontana, J.R.

1997-08-01

227

Paul holland: contributions to transfusion medicine.  

PubMed

Paul Holland began his career in transfusion medicine in 1963 as an assistant to Dr. Paul Schmidt in the Blood Bank at the National Institutes of Health (NIH). He served at the NIH for 20 years and retired in 1983 with the rank of Captain in the Public Health Service. He subsequently became the Medical Director/CEO of the Sacramento Medical Foundation Blood Center, now Blood Source, a position he held for the next 21 years. Paul Holland has authored/co-authored 265 articles, chapters and monographs, mostly concerning issues relating to either viral hepatitis or HIV. In addition to his research career, Paul was a very active educator, having contributed importantly to the development of many current thought leaders in transfusion medicine. His distinguished career also included important administrative roles in national and international organizations relevant to transfusion medicine. He also was the recipient of many honors and awards which has won him wide-spread renown and the respect of his many colleagues. PMID:23831199

McCarthy, Leo J

2013-07-04

228

The experience of critiquing published research: learning from the student and researcher perspective.  

PubMed

This paper commences with affirmation of the importance of research critique within academic programmes of study, and the context of this skill within the nursing profession. Judie (student) shares an experience from a Professional Doctorate in Education (EdD) assignment that involved selecting and critiquing a piece of published research. "The qualities of an effective mentor" (Gray and Smith, 2000) was critiqued using the Critical Appraisal Skills Programme (CASP, 2006) framework. Morag was the researcher and co-author (Gray and Smith, 2000) and was subsequently contacted by Judie for the purposes of validating her critique assignment. On the tenth anniversary since publication of her PhD research findings Morag reflects on the original article in the light of Judie's critique and shares evaluative comments. Some of the assignment critique is validated by Morag, whilst some of the evaluation demonstrates unreliability of critique shown by Judie. Discussion surrounding sufficiency of research critique through systematic examination of a published article, versus an original research report such as a thesis ensues. The student and researcher/author reveal their learning from this collaborative experience and conclude with recommendations for; setting critique assignments; authors publishing their research findings; and students undertaking critique assignments. PMID:21514888

Knowles, Judie M; Gray, Morag A

2011-04-22

229

The most-cited works in Geomorphology  

NASA Astrophysics Data System (ADS)

We conducted a review and analysis of the references cited in articles published (1995-2004) in the journal Geomorphology and also solicited comments from the authors of the most-cited works on their major influences. Of the 31,696 unique works cited in the journal, only 22 were referenced at least 20 times, with the vast majority (92%) cited only once or twice. We divided the citations into the 10 most-cited books (i.e., complete volumes) and 10 most-cited papers (i.e., journal articles, book chapters, reports). A total of 23 different researchers were responsible for the 20 works, with one (Wolman) being an author or co-author of a quarter of them. Seven of the ten most-cited papers were based on work in the USGS in the mid-twentieth century, indicating a particularly fruitful time of geomorphic research and a particularly important cohort of scientists. Based on our citation analysis and author commentaries, we suggest that classic works in geomorphology are most likely to be those that provide useful knowledge and those that incorporate interdisciplinary perspectives.

Doyle, Martin W.; Julian, Jason P.

2005-12-01

230

Object Ranking in Evolutional Networks via Link Prediction  

NASA Astrophysics Data System (ADS)

This paper proposes a framework to predict future significance or importance of nodes of a network through link prediction. The network can be of any kind, such as a co-authorship network where nodes are authors and co-authors are linked by edges. In this example, predicting significant nodes means to discover influential authors in the future. There are existing approaches to predicting such significant nodes in a future network and they typically rely on existing relationships between nodes. However, since such relationships are dynamic and would naturally change over time (e.g., new co-authorship continues to emerge), approaches based only on the current status of the network would have limited potentiality to predict the future. In contrast, our proposed approach first predicts future links between nodes by multiple supervised classifiers and applies the RankBoost algorithm for combining the predictions such that the links would lead to more precise predictions of a centrality (significance) measure of our choice. To demonstrate the effectiveness of our proposed approach, a series of experiments are carried out on the arXiv (HEP-Th) citation data set.

Miyanishi, Taiki; Seki, Kazuhiro; Uehara, Kuniaki

231

Citations Prize 2010 Citations Prize 2010  

NASA Astrophysics Data System (ADS)

Physics in Medicine & Biology (PMB) awards its 'Citations Prize' to the authors of the original research paper that has received the most citations in the preceding five years (according to the Institute for Scientific Information (ISI)). The lead author of the winning paper is presented with the Rotblat Medal (named in honour of Professor Sir Joseph Rotblat who was the second—and longest serving—Editor of PMB, from 1961-1972). The winning co-authors each receive a certificate. Photograph of the 2010 Citations Prize winners The winning authors Fernando Rannou (left), George Alexandrakis (holding the Rotblat Medal) and Arion Chatziioannou (right). The winner of the 2010 Citations Prize for the paper which has received the most citations in the previous 5 years (2005-2009) is Tomographic bioluminescence imaging by use of a combined optical-PET (OPET) system: a computer simulation feasibility study Authors: George Alexandrakis, Fernando R Rannou and Arion F Chatziioannou Reference: George Alexandrakis et al 2005 Phys. Med. Biol. 50 4225-41 Discussion of the significance of the winning paper can be found on medicalphysicsweb (medicalphysicsweb.org/cws/article/research/44334). Our congratulations go to the winning authors. Steve Webb Editor-in-Chief Simon Harris Publisher

Webb, Steve; Harris, Simon

2010-12-01

232

Citations Prize 2011 Citations Prize 2011  

NASA Astrophysics Data System (ADS)

Physics in Medicine & Biology (PMB) awards its 'Citations Prize' to the authors of the original research paper that has received the most citations in the preceding five years (according to the Institute for Scientific Information (ISI)). The lead author of the winning paper is presented with the Rotblat Medal (named in honour of Professor Sir Joseph Rotblat who was the second—and longest serving—Editor of PMB, from 1961-1972). The winning co-authors each receive a certificate. Susan Hagness (left) receiving the Rotblat Medal from Robert Jeraj of PMB's Editorial Board (right) on behalf of Mariya Lazebnik. The winner of the 2011 Citations Prize for the paper which has received the most citations in the previous 5 years (2006-2010) is A large-scale study of the ultrawideband microwave dielectric properties of normal, benign and malignant breast tissues obtained from cancer surgeries Authors: Mariya Lazebnik, Dijana Popovic, Leah McCartney, Cynthia B Watkins, Mary J Lindstrom, Josephine Harter, Sarah Sewall, Travis Ogilvie, Anthony Magliocco, Tara M Breslin, Walley Temple, Daphne Mew, John H Booske, Michal Okoniewski and Susan C Hagness Reference: Mariya Lazebnik et al 2007 Phys. Med. Biol. 52 6093-115 Discussion of the significance of the winning paper can be found on medicalphysicsweb (medicalphysicsweb.org/cws/article/research/47814). Our congratulations go to the winning authors. Steve Webb Editor-in-Chief Simon Harris Publisher

Webb, Steve; Harris, Simon

2011-12-01

233

Visible and Infrared Optical Design for the ITER Upper Ports  

SciTech Connect

This document contains the results of an optical design scoping study of visible-light and infrared optics for the ITER upper ports, performed by LLNL under contract for the US ITER Project Office. ITER is an international collaboration to build a large fusion energy tokamak with a goal of demonstrating net fusion power for pulses much longer than the energy confinement time. At the time of this report, six of the ITER upper ports are planned to each to contain a camera system for recording visible and infrared light, as well as other diagnostics. the performance specifications for the temporal and spatial resolution of this system are shown in the Section II, Functional Specifications. They acknowledge a debt to Y. Corre and co-authors of the CEA Cadarache report ''ITER wide-angle viewing and thermographic and visible system''. Several of the concepts used in this design are derived from that CEA report. The infrared spatial resolution for optics of this design is diffraction-limited by the size of the entrance aperture, at lower resolution than listed in the ITER diagnostic specifications. The size of the entrance aperture is a trade-off between spatial resolution, optics size in the port, and the location of relay optics. The signal-to-noise ratio allows operation at the specified time resolutions.

Lasnier, C; Seppala, L; Morris, K; Groth, M; Fenstermacher, M; Allen, S; Synakowski, E; Ortiz, J

2007-03-01

234

The Price of Paying Taxes: How Tax Preparation and Refund Loan Fees Erode the Benefits of the EITC  

NSDL National Science Digital Library

For the first time scholars and researchers have gotten together and prepared an analytical survey on the relationship between Earned Income Tax Credit (EITC) recipients and the location of tax preparation services (such as H&R Block and Jackson Hewitt) that offer e-filing and tax returns. Available in Adobe Acrobat (.pdf), and co-authored by the Brookings Urban Center and the Progressive Policy Institute, this report "analyzes information on the commercial tax preparation industry and the spatial distribution of its firms." The report also contains information regarding the concentration of "fast cash" refund loan facilities within low-income communities throughout the nationÂs 100 largest metropolitan areas, and provides an estimate of the total amount spent on tax preparation and loans by EITC recipients. According to the report, EITC recipients dished-out approximately $2 billion for tax preparation services and products in 1999, with more than half of all low-income families purchasing refund loans in some of the nation's largest cities and suburbs. To help decrease the amount of money spent on these types of services, the authors of the report outlined a policy agenda that would help EITC recipients maintain the full value of their return. Some of the agenda recommendations include simplifying tax credits for low-income families; broadening the availability of free and affordable tax preparation assistance and electronic filing of returns; and expanding access to low-cost bank accounts to promote direct deposit of EITC refunds.

Burns, Megan.; Forman, Benjamin.; Kim, Anne.; Berube, Alan.

2002-01-01

235

Beyond the City: The Rural Contribution to Development  

NSDL National Science Digital Library

The situation of rural communities in Latin America and the Caribbean is in some cases quite dire, and this report from the World Bank offers some timely commentary on the economic opportunities in these areas of the world. Released in February 2005, this 352-page report prepared by a team of researchers led by Guillermo Perry evaluates the effect of the rural sector on national growth, poverty reduction, and environmental degradation. The casual visitor may want to peruse some highlights from the report, browse through a presentation, or listen to an audio interview with co-author Daniel Lederman. In the report, Lederman remarks that "The rural contribution to development in the region has been hampered by insufficient investment in public services". The report offers a number of policy recommendations, including the suggestion that "success in reducing poverty in marginalized regions will depend on the ability of both central and local governments to work with local communities to identify economic opportunities and constraints and to balance local needs with national interests."

236

On advanced estimation techniques for exoplanet detection and characterization using ground-based coronagraphs  

NASA Astrophysics Data System (ADS)

The direct imaging of planets around nearby stars is exceedingly difficult. Only about 14 exoplanets have been imaged to date that have masses less than 13 times that of Jupiter. The next generation of planet-finding coronagraphs, including VLT-SPHERE, the Gemini Planet Imager, Palomar P1640, and Subaru HiCIAO have predicted contrast performance of roughly a thousand times less than would be needed to detect Earth-like planets. In this paper we review the state of the art in exoplanet imaging, most notably the method of Locally Optimized Combination of Images (LOCI), and we investigate the potential of improving the detectability of faint exoplanets through the use of advanced statistical methods based on the concepts of the ideal observer and the Hotelling observer. We propose a formal comparison of techniques using a blind data challenge with an evaluation of performance using the Receiver Operating Characteristic (ROC) and Localization ROC (LROC) curves. We place particular emphasis on the understanding and modeling of realistic sources of measurement noise in ground-based AO-corrected coronagraphs. The work reported in this paper is the result of interactions between the co-authors during a week-long workshop on exoplanet imaging that was held in Squaw Valley, California, in March of 2012.

Lawson, Peter R.; Poyneer, Lisa; Barrett, Harrison; Frazin, Richard; Caucci, Luca; Devaney, Nicholas; Furenlid, Lars; G?adysz, Szymon; Guyon, Olivier; Krist, John; Maire, Jérôme; Marois, Christian; Mawet, Dimitri; Mouillet, David; Mugnier, Laurent; Pearson, Iain; Perrin, Marshall; Pueyo, Laurent; Savransky, Dmitry

2012-07-01

237

Wave propagation in materials with non convex equation of state  

NASA Astrophysics Data System (ADS)

Exhaustive studies have described the behaviour of materials and wave propagation across them when they obey to Bethe's first condition. This means that the equations of state and the isentropes in the (P,V) plane are convex and that the sound speed is an increasing function of the density. In that case, steady dynamic pressure waves are compression shock waves or expansion fans. But materials can often reach states where this condition is violated. This happens for instance with phase transitions, dissociations, near the critical point, and in BZT fluids. Across these thermodynamic states, wave propagation has been studied only in a few specific cases by Zel'dovitch, Duvall, Plohr, Menikoff, Brun and their co-authors, but the general case remained to be explained. Our purpose is to provide the explanation of the successive waves which can occur in the general case when a wave propagates through a material with a non convex equation of state. We show that decrease of the sound speed introduces isentropic compression waves in the middle of shock waves and released shocks in the middle of expansion fans. After basic phenomena explanations, we illustrate them on the example of a virtual material which gathers all these cases. Hydrocode calculations based on this material show the difficulties of numerical schemes to reproduce the physical features.

Heuze, Olivier; Jaouen, Stephane; Jourdren, Herve

2007-06-01

238

A "reader's theater" intervention to managing grief: posttherapy reflections by a family and clinical team.  

PubMed

The sudden and accidental death of a child can be one of the most devastating events in the life of a family. This paper describes one couple's reflections of their grief and mourning following the death of their adolescent son as well as the clinical team's reflections of therapy. The uniqueness of this paper is that it offers a "reader's theater" intervention that enabled further change to occur. The clinical team used a belief model, emphasizing that altering constraining beliefs is at the heart of healing from such tragedies as sudden death (Wright, Watson, & Bell, 1996). This approach is operationalized through therapeutic conversations between family members, clinician, and clinical team. Interventions such as reflecting teams, therapeutic letters, and "homework tasks" were used to modify or challenge constraining beliefs of both the family members and the clinical team members. However, the intent to co-author a paper with this couple provided the serendipity intervention of a "reader's theater" that further served to identify, affirm, and solidify facilitating beliefs. PMID:9474525

Levac, A M; McLean, S; Wright, L M; Bell, J M

1998-01-01

239

Bibliometric data in clinical cardiology revisited. The case of 37 Dutch professors.  

PubMed

In this paper, we assess the bibliometric parameters of 37 Dutch professors in clinical cardiology. Those are the Hirsch index (h-index) based on all papers, the h-index based on first authored papers, the number of papers, the number of citations and the citations per paper. A top 10 for each of the five parameters was compiled. In theory, the same 10 professors might appear in each of these top 10s. Alternatively, each of the 37 professors under assessment could appear one or more times. In practice, we found 22 out of these 37 professors in the 5 top 10s. Thus, there is no golden parameter. In addition, there is too much inhomogeneity in citation characteristics even within a relatively homogeneous group of clinical cardiologists. Therefore, citation analysis should be applied with great care in science policy. This is even more important when different fields of medicine are compared in university medical centres. It may be possible to develop better parameters in the future, but the present ones are simply not good enough. Also, we observed a quite remarkable explosion of publications per author which can, paradoxical as it may sound, probably not be interpreted as an increase in productivity of scientists, but as the effect of an increase in the number of co-authors and the strategic effect of networks. PMID:21526387

Opthof, T; Wilde, A A M

2011-05-01

240

Long-term outcome of idiopathic hypertrophic thoracic pachymeningitis.  

PubMed

Idiopathic hypertrophic spinal pachymeningitis (IHSP) is a comparatively rare disease characterized by hypertrophic inflammation of the dura mater and clinical symptoms that progress from local pain to myelopathy. We report a case of IHSP followed up for 20 years in a 46-year-old man. Expansive laminoplasty was performed in 1991, and this case has been previously reported by a co-author. After 17 years, the patient's gait disturbance returned. Physical examination and imaging confirmed IHSP that had developed into syringomyelia at the T2-L1 conus level. This case was diagnosed as adhesive spinal arachnoiditis due to pachymeningitis caused by syringomyelia. T1-T4 laminectomy, a syringo-subarachnoid shunt (S-S shunt), and L2-L3 laminectomy were performed. The patient again developed dysesthesia and gait disturbance 3 years after the second operation. Most reports of IHSP have limited their focus to short-term follow-up after initial treatment with no long-term results. At present, there are only five reports referring to long-term results of greater than 5 years. All but one case needed additional surgery. To the best of our knowledge, this is the first case in which syringomyelia occurred in a patient with IHSP. It is important to note that syringomyelia may be a cause of symptom recrudescence during long-term follow-up in IHSP patients. PMID:21594749

Tsutsui, Mio; Yasuda, Taketoshi; Kanamori, Masahiko; Hori, Takeshi; Kimura, Tomoatsu

2011-05-19

241

Research ethics capacity development in Africa: exploring a model for individual success.  

PubMed

The Johns Hopkins-Fogarty African Bioethics Training Program (FABTP) has offered a fully-funded, one-year, non-degree training opportunity in research ethics to health professionals, ethics committee members, scholars, journalists and scientists from countries across sub-Saharan Africa. In the first 9 years of operation, 28 trainees from 13 African countries have trained with FABTP. Any capacity building investment requires periodic critical evaluation of the impact that training dollars produce. In this paper we describe and evaluate FABTP and the efforts of its trainees. Our data show that since 2001, the 28 former FABTP trainees have authored or co-authored 105 new bioethics-related publications; were awarded 33 bioethics-related grants; played key roles on 78 bioethics-related research studies; and participated in 198 bioethics workshops or conferences. Over the past nine years, trainees have collectively taught 48 separate courses related to bioethics and have given 170 presentations on various topics in the field. Many former trainees have pursued and completed doctoral degrees in bioethics; some have become editorial board members for bioethics journals. Female trainees were, on average, less experienced at matriculation and produced fewer post-training outputs than their male counterparts. More comprehensive studies are needed to determine the relationships between age, sex, previous experience and training program outputs. PMID:22708713

Ali, Joseph; Hyder, Adnan A; Kass, Nancy E

2012-06-18

242

Almost famous: E. Clark Noble, the common thread in the discovery of insulin and vinblastine  

PubMed Central

CLARK NOBLE WAS ONE OF THE FIRST members of the University of Toronto insulin team and came within a coin toss of replacing Charles Best as Frederick Banting's assistant during the summer of 1921. Noble performed important early studies helping to characterize insulin's action, and he co-authored many of the original papers describing insulin. Because mass production of insulin from livestock pancreata had proved elusive throughout 1922, J.J.R. Macleod hired Noble during the summer of 1923 to help him test and develop a new method for producing commercial quantities of insulin that Macleod believed would revolutionize insulin production. However, commercial production of insulin from fish proved impractical and was dropped by 1924, as methods to produce large quantities of mammalian insulin had improved very rapidly. Noble later played a small but critical role in the most important Canadian contribution to cancer chemotherapy research: the discovery of vinca alkaloids by his brother Robert Laing Noble. Although one might expect that a physician involved in 2 of Canada's most important medical discoveries during the 20th century must be famous, such was not Clark Noble's fate. He died without so much as an obituary in CMAJ.

Wright, James R.

2002-01-01

243

Global partnerships for international fieldwork in occupational therapy: reflection and innovation.  

PubMed

International fieldwork placements (IFPs) have become very popular among healthcare students including those in occupational therapy programmes. There are many potential benefits that can accrue to the students; however, there are critiques of international placements especially for students going to underserviced areas. The purpose of this paper is to provide a case study/model programme description that critically reflects on six partnerships in three underserviced countries that provide IFPs to students from one Canadian university. The personal opinions of each partner were collected verbally, by email and by a qualitative review of the past 10?years of partnership interaction. Some of the benefits reported by partners include the development of an increased number of sustainable long-term quality placements, orientation materials, student supports and the involvement of university faculty in research and capacity building projects in partner countries. A number of challenges were identified including the need for an expanded formal agreement, more bilateral feedback and examination of supervision models. This paper examines a limited number of partnerships with only one Canadian partner. Direct input of students is not utilized, although feedback given to co-authors by students is reflected. More research is needed on perspectives of partners in IFPs, impact of IFPs on clinical practice in student's home countries, impact of IFPS on underserviced areas and effective strategies for debriefing. PMID:23661362

Cameron, Debra; Cockburn, Lynn; Nixon, Stephanie; Parnes, Penny; Garcia, Lesley; Leotaud, Jacqui; MacPherson, Kristina; Mashaka, Peter A; Mlay, Ruth; Wango, Julius; Williams, Trish

2013-06-01

244

Resource Economics  

NASA Astrophysics Data System (ADS)

Resource Economics is a text for students with a background in calculus, intermediate microeconomics, and a familiarity with the spreadsheet software Excel. The book covers basic concepts, shows how to set up spreadsheets to solve dynamic allocation problems, and presents economic models for fisheries, forestry, nonrenewable resources, stock pollutants, option value, and sustainable development. Within the text, numerical examples are posed and solved using Excel's Solver. These problems help make concepts operational, develop economic intuition, and serve as a bridge to the study of real-world problems of resource management. Through these examples and additional exercises at the end of Chapters 1 to 8, students can make dynamic models operational, develop their economic intuition, and learn how to set up spreadsheets for the simulation of optimization of resource and environmental systems. Book is unique in its use of spreadsheet software (Excel) to solve dynamic allocation problems Conrad is co-author of a previous book for the Press on the subject for graduate students Approach is extremely student-friendly; gives students the tools to apply research results to actual environmental issues

Conrad, Jon M.

2000-01-01

245

Young Voices on Climate Change: The Paul F-Brandwein 2010 NSTA Lecture  

NASA Astrophysics Data System (ADS)

Lynne Cherry Brandwein Lecture March 2010 National Science Teachers Association (NSTA) Conference, Philadelphia, PA. Young Voices on Climate Change: Inspired and Empowered Youth Tackle Climate Science and Find Climate Solutions. As a child, Lynne Cherry was profoundly connected to the natural world and a special place. She watched the destruction of her world. Now, through her Young Voices on Climate Change project, she is trying to give teachers and young people the tools to prevent planetary meltdown on a greater scale. Global climate change is upon us and the need for education and action is immediate. Outreach, visual storytelling, and scientific understanding are especially necessary in light of the recent polls that show that the public is becoming more confused and less concerned about climate change. Cherry's climate book, co-authored with photojournalist Gary Braasch, and her Young Voices on Climate Change films feature climate solutions. They're about win-win—save the environment, protect human health, reduce global warming gases, demonstrate youth making a difference with practical tools, motivate engagement in climate science, take pride in increased science literacy, reach young people through their hearts as well as their minds, and save money. Although young people can help their parents, peers and communities understand climate science, they can also show them that reducing CO2 is in their economic interest, and spur them to take action. School carbon reduction initiatives are spilling over into communities yielding measurable results in both global warming gas reductions and significant monetary savings.

Cherry, Lynne

2011-04-01

246

Statistical physics applied to ecology  

NASA Astrophysics Data System (ADS)

Understanding an ecosystem is a formidable many-body problem. One has an interacting system, made up of individuals of various species with imperfectly known interactions, mainly governed by chance and characterized by a wide range of spatial and temporal scales. For example, in tropical forests across the globe, ecologists have been able to measure certain quantities such as the relative species abundance distribution, the species area relationship, and beta diversity, the probability that two trees separated by a given distance belong to the same species. In order to make progress, it is important to distill what one hopes are the essential ingredients of an ecosystem and incorporate them in tractable models whose predictions can then be compared with the observed data. Such an interplay between empirical data and theory is useful for the formulation of realistic models of ecosystems. A summary of recent work along these lines will be presented. Co-author: Amos Maritan Collaborators: John Damuth, Fangliang He, Steve Hubbell, Andrea Rinaldo, Igor Volkov and Tommaso Zillio

Banavar, Jayanth

2005-03-01

247

Energy justice and foundations for a sustainable sociology of energy  

NASA Astrophysics Data System (ADS)

This dissertation proposes an approach to energy that transcends the focus on energy as a mere technical economic or engineering problem, is connected to sociological theory as a whole, and takes issues of equality and ecology as theoretical starting points. In doing so, the work presented here puts ecological and environmental sociological theory, and the work of environmental justice scholars, feminist ecologists, and energy scholars, in a context in which they may complement one another to broaden the theoretical basis of the current sociology of energy. This theoretical integration provides an approach to energy focused on energy justice. Understanding energy and society in the terms outlined here makes visible energy injustice, or the interface between social inequalities and ecological depredations accumulating as the social and ecological debts of the modern energy regime. Systems ecology is brought into this framework as a means for understanding unequal exchange, energy injustice more generally, and the requirements for long-term social and ecological reproduction in ecological terms. Energy developments in Ecuador and Cuba are used here as case studies in order to further develop the idea of energy justice and the theory of unequal ecological exchange. The point is to broaden the framework of the contemporary critical sociology of energy, putting energy justice at its heart. This dissertation contains previously published and unpublished co-authored material.

Holleman, Hannah Ann

248

Double-beta decay: Some recent results and developments  

NASA Astrophysics Data System (ADS)

A brief review and status of theoretical issues associated with double-beta decay (??-decay) is given. The final results of the measurement of 2? ??-decay of 100Mo to the first excited 0+ state in 100Ru are presented prior to publication. Corrections to the earlier PNL/USC/ITEP/YPI measurement of 2? ??-decay of 76Ge are also given prior to publication. Finally, a status report and first results of the phase-I of the International Germanium Experiment (IGEX) are presented. The impublished data presented here resulted from collaborative research with the following co-authors, and will be published in the open literature: R. J. Arthur, A. S. Barabash, R. L. Brodzinski, J. I. Collar, H. Courant, E. García, C. K. Guerard, W. K. Hensley, I. V. Kirpichnikov, J. R. Meier, H. S. Miley, A. Morales, J. Morales, R. Nún~ez-Lagos, S. B. Osetrov, V. S. Pogosov, A. A. Pomansky, J. Puimedón, J. H. Reeves, K. Rudick, C. Sáenz, A. Salinas, M. L. Sarsa, A. A. Smolnikov, A. S. Starostin, A. G. Tamanyan, S. I. Vasiliev, J. A. Villar, and V. I. Umatov

Avignone, F. T.

249

Opposition effect of Saturn's rings: relevant hints of ring physical properties  

NASA Astrophysics Data System (ADS)

We present here a summary of our previous modeling of the Saturn's rings opposition effect using Cassini/ISS data [1]. The opposition effect is characterized by a surge in the intensity of any grainy surface, when the phase angle approaches zero degree. This effect can be used to constrain the nature of the regolith and the filling factor of the ring layer. We have used several opposition effect models to derive the physical properties of the rings [1], and we are about to publish the results of this work [2]. A recent work of Degiorgio et al. 2011 (EPSC-DPS meeting #7320), hereafter [3], was drawn to our attention. This work uses some methods (data processing, and physical modeling) similar to [1], and found similar results to [1], without citing [1]. One of the co-authors of [3] being the PhD advisor of [1], it seems unlikely that the works of [1] were unknown to [3]. Moreover, [3] failed to acknowledge the reference works on the Saturn's rings like [4,5,6,7]. This is particularly concerning since the results of [4,5,6,7] explicitly disprove the conclusions of [3]. The present communication dispels the misconceptions and inaccuracies exposed in [3].

Deau, E.

2012-09-01

250

Scientific discrimination and the activist scientist: L.C. Dunn and the professionalization of genetics and human genetics in the United States.  

PubMed

During the 1920s and 1930s geneticist L.C. Dunn of Columbia University cautioned Americans against endorsing eugenic policies and called attention to eugenicists' less than rigorous practices. Then, from the mid-1940s to early 1950s he attacked scientific racism and Nazi Rassenhygiene by co-authoring Heredity, Race and Society with Theodosius Dobzhansky and collaborating with members of UNESCO (United Nations Educational, Scientific, and Cultural Organization) on their international campaign against racism. Even though shaking the foundations of scientific discrimination was Dunn's primary concern during the interwar and post-World War II years, his campaigns had ancillary consequences for the discipline. He contributed to the professionalization of genetics during the 1920s and 1930s and sought respectability for human genetics in the 1940s and 1950s. My article aims to elucidate the activist scientist's role in undermining scientific discrimination by exploring aspects of Dunn's scientific work and political activism from the 1920s to 1950s. Definitions are provided for scientific discrimination and activist scientist. PMID:19831201

Gormley, Melinda

2009-01-01

251

The "useful questions of heredity" before Mendel.  

PubMed

Now Emeritus Head of the Mendelianum (Mendel Museum) in Brno, Czech Republic, Vítezslav Orel began his academic career as a student at the Brno Agriculture University. His work was interrupted first by the Nazi invasion and then by the communist revolution, when the science of genetics was denounced and replaced by Lysenko pseudogenetics. V. O. was dismissed from his position at the Poultry Research Institute and assigned to work at a small duck farm outside Brno. When the "Lysenkoist madness" subsided, Professor Jaroslav Krizenecky (1896-1964), teacher of V. O., was allowed to develop the museum in recognition of Mendel's contributions. V. O. assisted him by conducting research on the history of Mendel and of genetics. On Jaroslav Krizenecky's death, V. O. became head of the Mendelianum. V. O. has become an internationally recognized figure in the study of the history of science, having published nearly 200 papers in Czech and 10 other languages. Orel's most recent books, published by Oxford University Press, make use of the rich archives of the Mendelianum that he helped create. Gregor Mendel-The First Geneticist (Orel 1996) is the definitive biography of Mendel, and in 2001, V. O. and co-author R. J. Wood published Genetic Prehistory in Selective Breeding: A Prelude to Mendel. (Biography from Margaret H. Peaslee). PMID:19494029

Orel, Vítezslav

2009-06-03

252

INTERNATIONAL COLLABORATION ON CO2 SEQUESTRATION  

SciTech Connect

The ocean represents the largest potential sink for anthropogenic CO{sub 2}. In order to better understand this potential, Japan, Norway, and the United States signed a Project Agreement for International Collaboration on CO{sub 2} Ocean Sequestration in December 1997; since that time, Canada and ABB (Switzerland) have joined the project. The objective of the project is to investigate the technical feasibility of, and improve understanding of the environmental impacts from, CO{sub 2} ocean sequestration in order to minimize the impacts associated with the eventual use of this technique to reduce greenhouse gas concentrations in the atmosphere. The project will continue through March 31, 2002, with a field experiment to take place in the summer of 2000 off the Kona Coast of Hawaii. The implementing research organizations are the Research Institute of Innovative Technology for the Earth (Japan), the Norwegian Institute for Water Research (Norway), and the Massachusetts Institute of Technology (USA). The general contractor for the project will be the Pacific International Center for High Technology Research in Hawaii. A Technical Committee has been formed to supervise the technical aspects and execution of this project. The members of this committee are the co-authors of this paper. In this paper we discuss key issues involved with the design, ocean engineering, measurements, siting, and costs of this experiment.

H.J. Herzog; E.E. Adams

1999-08-23

253

X-ray Emissions Detected From Elusive Cosmic Objects  

NASA Astrophysics Data System (ADS)

A type of celestial object that has long stumped astronomers has been found to emit X-rays, thus proving a theory of how the objects form. Dr. Steven Pravdo of NASA's Jet Propulsion Laboratory, Pasadena, Calif., and other scientists have concluded that these objects, called Herbig Haro objects, are produced by high velocity shocks. Pravdo is the lead author of a paper published in the Oct. 18 issue of the journal Nature. Herbig Haro objects are found in regions where new stars are forming. They are nebulas, or dust and gas clouds. They form when high-velocity gas emitted from young stars collides with clouds of interstellar material. The collision heats the gas in the surrounding nebula to sufficiently high temperatures to produce X-rays. Observations for the past 20 years showed no evidence of X-ray emission from these objects, which are named for astronomers George Herbig and Guillermo Haro. Previous instruments lacked the resolution and sensitivity necessary to 'see' these X-rays. The discovery of the X-ray emissions was possible through the very powerful Advanced CCD Imaging Spectrometer on NASA's Chandra X-ray Observatory, which has been in orbit since 1999. On Oct. 8, 2000, astrophysicists used the instrument to study HH2, one of the brightest and closest Herbig Haro objects in the Orion Nebula. They determined that HH2 contains shock-heated material with a temperature of about 1 million degrees Kelvin. Pravdo and his team used three criteria to rule out the possibility that the emissions came from any other source. First, Chandra's high spatial resolution pinpointed the location of the X-rays at HH2. Second, the X-rays appeared to be covering a region bigger than a star. Third, the temperature of the X-rays was about 1 million degrees, cooler than nearby X-ray stars. One million degrees is about the temperature expected if material moving at about 300 kilometers per second (about 600,000 miles per hour) collides. At this speed, you could go from Los Angeles to San Diego and back in one second. The principal investigator of the Advanced CCD Imaging Spectrometer, Dr. Gordon Garmire of Pennsylvania State University, University Park, is a co-author of the paper. Other co-authors include Drs. Yohko Tsuboi, Yoshitomo Maeda and Eric Feigelson, all from Pennsylvania State University, and Dr. John Bally from the University of Colorado, Boulder. The Advanced CCD Imaging Spectrometer X-ray camera was developed for NASA by Pennsylvania State University and the Massachusetts Institute of Technology, Cambridge, Mass. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program. TRW, Inc., Redondo Beach, Calif., is the prime contractor for the spacecraft. The Smithsonian's Chandra X-ray Center controls science and flight operations from Cambridge, Mass. Images associated with this release are available on the World Wide Web at: http://chandra.harvard.edu AND http://chandra.nasa.gov The Chandra X-ray Observatory is managed for NASA by the Smithsonian Astrophysical Observatory, Cambridge, Mass. JPL is managed for NASA by the California Institute of Technology in Pasadena.

2001-10-01

254

Stellar family in crowded, violent neighbourhood proves to be surprisingly normal  

NASA Astrophysics Data System (ADS)

Using ESO's Very Large Telescope, astronomers have obtained one of the sharpest views ever of the Arches Cluster -- an extraordinary dense cluster of young stars near the supermassive black hole at the heart of the Milky Way. Despite the extreme conditions astronomers were surprised to find the same proportions of low- and high-mass young stars in the cluster as are found in more tranquil locations in our Milky Way. ESO PR Photo 21a/09 The Arches Cluster ESO PR Photo 21b/09 The Centre of the Milky Way ESO PR Photo 21c/09 Around the Arches Cluster ESO PR Video 21a/09 A voyage to the heart of the Milky Way The massive Arches Cluster is a rather peculiar star cluster. It is located 25 000 light-years away towards the constellation of Sagittarius (the Archer), and contains about a thousand young, massive stars, less than 2.5 million years old [1]. It is an ideal laboratory to study how massive stars are born in extreme conditions as it is close to the centre of our Milky Way, where it experiences huge opposing forces from the stars, gas and the supermassive black hole that reside there. The Arches Cluster is ten times heavier than typical young star clusters scattered throughout our Milky Way and is enriched with chemical elements heavier than helium. Using the NACO adaptive optics instrument on ESO's Very Large Telescope, located in Chile, astronomers scrutinised the cluster in detail. Thanks to adaptive optics, astronomers can remove most of the blurring effect of the atmosphere, and so the new NACO images of the Arches Cluster are even crisper than those obtained with telescopes in space. Observing the Arches Cluster is very challenging because of the huge quantities of absorbing dust between Earth and the Galactic Centre, which visible light cannot penetrate. This is why NACO was used to observe the region in near-infrared light. The new study confirms the Arches Cluster to be the densest cluster of massive young stars known. It is about three light-years across with more than a thousand stars packed into each cubic light-year -- an extreme density a million times greater than in the Sun's neighbourhood. Astronomers studying clusters of stars have found that higher mass stars are rarer than their less massive brethren, and their relative numbers are the same everywhere, following a universal law. For many years, the Arches Cluster seemed to be a striking exception. "With the extreme conditions in the Arches Cluster, one might indeed imagine that stars won't form in the same way as in our quiet solar neighbourhood," says Pablo Espinoza, the lead author of the paper reporting the new results. "However, our new observations showed that the masses of stars in this cluster actually do follow the same universal law". In this image the astronomers could also study the brightest stars in the cluster. "The most massive star we found has a mass of about 120 times that of the Sun," says co-author Fernando Selman. "We conclude from this that if stars more massive than 130 solar masses exist, they must live for less than 2.5 million years and end their lives without exploding as supernovae, as massive stars usually do." The total mass of the cluster seems to be about 30 000 times that of the Sun, much more than was previously thought. "That we can see so much more is due to the exquisite NACO images," says co-author Jorge Melnick. Note [1] The name "Arches" does not come from the constellation the cluster is located in (Sagittarius, i.e., the Archer), but because it is located next to arched filaments detected in radio maps of the centre of the Milky Way.

2009-06-01

255

A tribute to Dr. Robert C. Allen, an inspirational teacher, humanitarian, and friend (Nov. 18, 1950-Mar. 24, 2005).  

PubMed

Dr. Robert C. Allen was a gifted educator, as well as experienced ophthalmologist, who was a close personal friend of Dr. Edlich at the University of Virginia Health System. While serving on the faculty at the University of Virginia Health System, Dr. Allen proved to be a compassionate physician, who developed close personal relationships with the residents, faculty, and his patients. Dr. Allen was invited by Dr Edlich to be a member of the Editorial Board of the Journal of Long-Term Effects of Medical Implants. When Dr. Allen told Dr. Edlich that he had ocular melanoma in 2000, this news was a wake-up call to Dr. Edlich on the need to prevent skin cancer, as well as ocular melanoma. Empowered by this news, Dr. Edlich was honored to co-author four articles on skin cancer prevention, as well as the latest article focusing on prevention of ocular melanoma. The Ocular Melanoma Foundation (Richmond, VA (USA)) was founded in 2003 by Dr. Robert C. Allen to increase awareness, enhance education, and provide advocacy among both patients and health care professionals regarding this rare, but potentially lethal cancer. It has a website that provides patient information, up-to-date information and enables communication/ discourse between and among patients and practitioners (admin@ocularmelanoma.org). Dr. Allen died on March 24, 2005, at his home surrounded by family and loved ones. When surgeons are faced with challenging healthcare diseases, Dr. Edlich's mentor, Dr. Owen Wangensteen, advised Dr. Edlich that he should seek the advice and guidance of skilled basic scientists, who are familiar with the problem. Dr. Wangensteen is recognized as the greatest surgical teacher during the 20th century. Consequently, Dr. Edlich enlisted the advice and guidance from the two co-authors of the next article regarding the scientific basis for the selection of sunglasses to prevent the development of cataracts, pterygia, skin cancer, as well as ocular melanoma. Dr. Reichow is a Professor of Optometry at Pacific University College of Optometry (Forest Grove, OR (USA)). Dr. Citek is Associate Professor of Optometry at Pacific University College of Optometry (Forest Grove (USA)). In their comprehensive evaluation of sunglasses, they found some disturbing results. Despite being endorsed by The Skin Cancer Foundation, the Walgreens eyewear samples offer only partial protection to the potential hazards of sunlight exposure. Those individuals who spend considerable time outdoors should seek sun filter eyewear with impact resistant polycarbonate lenses that provide 100% ultraviolet filtration, high levels of blue light filtration, and full visual field lens/frame coverage as provided by high wrap eyewear. There are several brands that offer products with such protective characteristics. Performance sun eyewear by Nike Vision (Nike Inc., Portland OR [USA]), available in both corrective and plano (nonprescription) forms, is one such brand incorporating these protective features, as well as patented optical and tint designs. Numerous Nike styles offer interchangeable lens options to meet the changing environmental conditions encountered outdoors. These technologies are incorporated into performance-driven frame designs inspired by feedback from some of the world's best athletes. Nonprescription Nike eyewear are available on-line at http://www.nike.com/nikevision, as well as at various well-known retail outlets. Nonprescription and prescription Nike eyewear are also available at the offices of many eye care professionals. Even though our latest report did not include soft contact lens, it is important to emphasize that Dr. Reichow and Dr. Citek have played a leadership role in coordinating the development of the Nike MAXSIGHT, an innovative fully tinted soft contact lens. This contact lens provides distortion-free optics, whether or not you wear prescription contacts. They filter out more than 90% of harmful blue light and 95% of UVA and UVB. For the contact lens, you should go to the website for more information http://www.nike.com/nikevision/content.html

Edlich, Richard F; Greene, Jill A; Long, William B

2006-01-01

256

What measured blood loss tells us about postpartum bleeding: a systematic review  

PubMed Central

Background Meta-analyses of postpartum blood loss and the effect of uterotonics are biased by visually estimated blood loss. Objectives To conduct a systematic review of measured postpartum blood loss with and without prophylactic uterotonics for prevention of postpartum haemorrhage (PPH). Search strategy We searched Medline and PubMed terms (labour stage, third) AND (ergonovine, ergonovine tartrate, methylergonovine, oxytocin, oxytocics or misoprostol) AND (postpartum haemorrhage or haemorrhage) and Cochrane reviews without any language restriction. Selection criteria Refereed publications in the period 1988–2007 reporting mean postpartum blood loss, PPH (?500 ml) or severe PPH (?1000 ml) following vaginal births. Data collection and analysis Raw data were abstracted into Excel by one author and then reviewed by a co-author. Data were transferred to SPSS 17.0, and copied into RevMan 5.0 to perform random effects meta-analysis. Main results The distribution of average blood loss (29 studies) is similar with any prophylactic uterotonic, and is lower than without prophylaxis. Compared with no uterotonic, oxytocin and misoprostol have lower PPH (OR 0.43, 95% CI 0.23–0.81; OR 0.73, 95% CI 0.50–1.08, respectively) and severe PPH rates (OR 0.61, 95% CI 0.29–1.29; OR 0.74, 95% CI 0.52–1.04, respectively). Oxytocin has lower PPH (OR 0.65, 95% CI 0.60–0.70) and severe PPH (OR 0.71, 95% CI 0.56–0.91) rates than misoprostol, but not in developing countries. Conclusion Oxytocin is superior to misoprostol in hospitals. Misoprostol substantially lowers PPH and severe PPH. A sound assessment of the relative merits of the two drugs is needed in rural areas of developing countries, where most PPH deaths occur.

Sloan, NL; Durocher, J; Aldrich, T; Blum, J; Winikoff, B

2010-01-01

257

Interventions provided in the acute phase for mild traumatic brain injury: a systematic review  

PubMed Central

Background Most patients who sustain mild traumatic brain injury (mTBI) have persistent symptoms at 1 week and 1 month after injury. This systematic review investigated the effectiveness of interventions initiated in acute settings for patients who experience mTBI. Methods We performed a systematic review of all randomized clinical trials evaluating any intervention initiated in an acute setting for patients experiencing acute mTBI. All possible outcomes were included. The primary sources of identification were MEDLINE, Embase, PsycINFO, CINAHL, and the Cochrane Central register of Controlled Trials, from 1980 to August 2012. Hand searching of proceedings from five meetings related to mTBI was also performed. Study selection was conducted by two co-authors, and data abstraction was completed by a research assistant specialized in conducting systematic reviews. Study quality was evaluated using Cochrane’s Risk of Bias assessment tool. Results From a potential 15,156 studies, 1,268 abstracts were evaluated and 120 articles were read completely. Of these, 15 studies fulfilled the inclusion/exclusion criteria. One study evaluated a pharmacological intervention, two evaluated activity restriction, one evaluated head computed tomography scan versus admission, four evaluated information interventions, and seven evaluated different follow-up interventions. Use of different outcome measures limited the possibilities for analysis. However, a meta-analysis of three studies evaluating various follow-up strategies versus routine follow-up or no follow-up failed to show any effect on three outcomes at 6 to 12 months post-trauma. In addition, a meta-analysis of two studies found no effect of an information intervention on headache at 3 months post-injury. Conclusions There is a paucity of well-designed clinical studies for patients who sustain mTBI. The large variability in outcomes measured in studies limits comparison between them.

2013-01-01

258

A taxonomy for community-based care programs focused on HIV/AIDS prevention, treatment, and care in resource-poor settings  

PubMed Central

Community-based care (CBC) can increase access to key services for people affected by HIV/AIDS through the mobilization of community interests and resources and their integration with formal health structures. Yet, the lack of a systematic framework for analysis of CBC focused on HIV/AIDS impedes our ability to understand and study CBC programs. We sought to develop taxonomy of CBC programs focused on HIV/AIDS in resource-limited settings in an effort to understand their key characteristics, uncover any gaps in programming, and highlight the potential roles they play. Our review aimed to systematically identify key CBC programs focused on HIV/AIDS in resource-limited settings. We used both bibliographic database searches (Medline, CINAHL, and EMBASE) for peer-reviewed literature and internet-based searches for gray literature. Our search terms were ‘HIV’ or ‘AIDS’ and ‘community-based care’ or ‘CBC’. Two co-authors developed a descriptive taxonomy through an iterative, inductive process using the retrieved program information. We identified 21 CBC programs useful for developing taxonomy. Extensive variation was observed within each of the nine categories identified: region, vision, characteristics of target populations, program scope, program operations, funding models, human resources, sustainability, and monitoring and evaluation strategies. While additional research may still be needed to identify the conditions that lead to overall program success, our findings can help to inform our understanding of the various aspects of CBC programs and inform potential logic models for CBC programming in the context of HIV/AIDS in resource-limited settings. Importantly, the findings of the present study can be used to develop sustainable HIV/AIDS-service delivery programs in regions with health resource shortages.

Rachlis, Beth; Sodhi, Sumeet; Burciul, Barry; Orbinski, James; Cheng, Amy H.Y.; Cole, Donald

2013-01-01

259

The Evolution and Extinction of the Dinosaurs  

NASA Astrophysics Data System (ADS)

Written for non-specialists, this detailed survey of dinosaur origins, diversity, and extinction is designed as a series of successive essays covering important and timely topics in dinosaur paleobiology, such as "warm-bloodedness," birds as living dinosaurs, the new, non-flying feathered dinosaurs, dinosaur functional morphology, and cladistic methods in systematics. Its explicitly phylogenetic approach to the group is that taken by dinosaur specialists. The book is not an edited compilation of the works of many individuals, but a unique, cohesive perspective on Dinosauria. Lavishly illustrated with hundreds of new, specially commissioned illustrations by John Sibbick, world-famous illustrator of dinosaurs, the volume includes multi-page drawings as well as sketches and diagrams. First edition Hb (1996): 0-521-44496-9 David E. Fastovsky is Professor of Geosciences at the University of Rhode Island. Fastovsky, the author of numerous scientific publications dealing with Mesozoic vertebrate faunas and their ancient environments, is also scientific co-Editor of Geology. He has undertaken extensive fieldwork studying dinosaurs and their environments in Montana, North Dakota, Arizona, Mexico, and Mongolia. David B. Weishampel is a professor at the Center for Functional Anatomy and Evolution at Johns Hopkins University, School of Medicine. Weishampel is best known for discovering, researching, and naming several rare European dinosaur species. During the 1980s Weishampel gained fame for his work with American paleontologist Jack Horner and later named the famous plant-eating, egg-laying Orodromeus, Horner. Now, a decade after his pioneering studies with Horner, Weishampel is most widely known for his current work on the Romanian dinosaur fauna. He is the author and co-author of many titles, including The Dinosaur Papers, 1676-1906 (Norton, 2003); The Dinosauria, (University of California, 1990); and Dinosaurs of the East Coast, (Johns Hopkins University Press, 1996).

Fastovsky, David E.; Weishampel, David B.

2005-02-01

260

Surface modification and multiple exciton generation studies of lead(II) sulfide nanoparticles  

NASA Astrophysics Data System (ADS)

Solar energy is a green alternative to fossil fuels but solar technologies to date have been plagued by low conversion efficiencies and high input costs making solar power inaccessible to much of the developing world. Semiconductor nanoparticles (NPs) may provide a route to efficient, economical solar devices through a phenomenon called multiple exciton generation (MEG). Through MEG, semiconductor NPs use a high-energy input photon to create more than one exciton (electron-hole pair) per photon absorbed, thereby exhibiting large photoconversion efficiencies. While MEG has been studied in many NP systems, and we understand some of the factors that affect MEG, a rigorous analysis of the NP-ligand interface with respect to MEG is missing. This dissertation describes how the NP ligand shell directly affects MEG and subsequent charge carrier recombination. Chapter I describes the motivation for studying MEG with respect to NP surface chemistry. Chapter II provides an in-depth overview of the transient absorption experiment used to measure MEG in the NP samples. Chapter III highlights the effect of oleic acid and sodium 2, 3-dimercaptopropane sulfonate on MEG in PbS NPs. The differences in carrier recombination were accounted for by two differences between these ligands: the coordinating atom and/or the secondary structure of the ligand. Because of these hypotheses, experiments were designed to elucidate the origin of these effects by controlling the NP ligand shell. Chapter IV details a viable synthetic route to thiol and amine-capped PbS NPs using sodium 3-mercaptopropane sulfonate as an intermediate ligand. With the versatile ligand exchange described in Chapter IV, the MEG yield and carrier recombination was investigated for ligands with varying headgroups but the same secondary structure. The correlation of ligand donor atom to MEG is outlined in Chapter V. Finally, Chapter VI discusses the conclusions and future outlook of the research reported in this dissertation. This dissertation includes previously published and unpublished co-authored material.

Zemke, Jennifer M.

261

3min. poster presentations of B01  

NASA Astrophysics Data System (ADS)

We give a report on recommendations from ILEWG International conferences held at Cape Canaveral in 2008 (ICEUM10), and in Beijing in May 2010 with IAF (GLUC -ICEUM11). We discuss the different rationale for Moon exploration. Priorities for scientific investigations include: clues on the formation and evolution of rocky planets, accretion and bombardment in the inner solar system, comparative planetology processes (tectonic, volcanic, impact cratering, volatile delivery), historical records, astrobiology, survival of organics; past, present and future life. The ILEWG technology task group set priorities for the advancement of instrumenta-tion: Remote sensing miniaturised instruments; Surface geophysical and geochemistry package; Instrument deployment and robotic arm, nano-rover, sampling, drilling; Sample finder and collector. Regional mobility rover; Autonomy and Navigation; Artificially intelligent robots, Complex systems. The ILEWG ExogeoLab pilot project was developed as support for instru-ments, landers, rovers,and preparation for cooperative robotic village. The ILEWG lunar base task group looked at minimal design concepts, technologies in robotic and human exploration with Tele control, telepresence, virtual reality; Man-Machine interface and performances. The ILEWG ExoHab pilot project has been started with support from agencies and partners. We discuss ILEWG terrestrial Moon-Mars campaigns for validation of technologies, research and human operations. We indicate how Moon-Mars Exploration can inspire solutions to global Earth sustained development: In-Situ Utilisation of resources; Establishment of permanent robotic infrastructures, Environmental protection aspects; Life sciences laboratories; Support to human exploration. Co-Authors: ILEWG Task Groups on: Science, Technology, Robotic village, Lunar Bases , Commercial and Societal aspects, Roadmap synergies with other programmes, Public en-gagemnet and Outreach, Young Lunar Explorers.

Foing, Bernard H.

262

Closure of computational fluid models with evolving-background ?f kinetics  

NASA Astrophysics Data System (ADS)

A new method of applying simulation particles to close implicit time-dependent nonlinear extended-MHD modeling has been formulated, analyzed, and tested. The new method has three important features that will likely prove useful for any evolving-background ?f simulation. First, the fluid equations should be closed with particle information at the momentum-density level to minimize statistical noise from closure terms. Second, the particle motion is described by a particular velocity that represents dynamics without thermal forces, separating the kinetic dynamics from the fluid dynamics. With the use of this particular velocity, there exists symmetry between the ?f weight evolution equation and the fluid closure. Third, an optimal prescription for particle shape in velocity space can be derived using Hermite polynomials. The symmetry and optimal shaping together ensure that the numerical kinetic distortion acquires no low-order moments, analogous to the analytical Chapman-Enskog-like approach. They also lead to a conserved energy integral for the discrete nonlinear system, and the r.m.s. particle weight is bounded. With this advance in computation, combined particle-fluid simulation of low-frequency extended-MHD dynamics with majority ion kinetics is now possible. The new method has been implemented for kinetic ion dynamics with fluid electron modeling in the 2D code IMP2. The method successfully reproduces dynamics where the electric field is perpendicular to the magnetic field, including kinetic stabilization of the isothermal g-mode in a slab. Extensions to include temperature gradient and arbitrary polarization are described. Co-author: W. D. Nystrom, Coronado Consulting, Lamy, NM

Barnes, D. C.

2007-11-01

263

Effect of Zinc Supplementation on Pregnancy and Infant Outcomes: A Systematic Review  

PubMed Central

Poor maternal zinc status has been associated with foetal loss, congenital malformations, intrauterine growth retardation, reduced birth weight, prolonged labour and preterm or post-term deliveries. A meta-analysis completed in 2007 showed that maternal zinc supplementation resulted in a small but significant reduction in preterm birth. The purposes of this analysis are to update that previous review and expand the scope of assessment to include maternal, infant and child health outcomes. Electronic searches were carried out to identify peer-reviewed, randomised controlled trials where daily zinc supplementation was given for at least one trimester of pregnancy. The co-authors applied the study selection criteria, assessed trial quality and abstracted data. A total of 20 independent intervention trials involving more than 11 000 births were identified. The 20 trials took place across five continents between 1977 and 2008. Most studies assessed the zinc effect against a background of other micronutrient supplements, but five were placebo-controlled trials of zinc alone. The provided dose of supplemental zinc ranged from 5 to 50 mg/day. Only the risk of preterm birth reached statistical significance (summary relative risk 0.86 [95% confidence interval 0.75, 0.99]). There was no evidence that supplemental zinc affected any parameter of foetal growth (risk of low birth weight, birth weight, length at birth or head circumference at birth). Six of the 20 trials were graded as high quality. The evidence that maternal zinc supplementation lowers the risk of preterm birth was graded low; evidence for a positive effect on other foetal outcomes was graded as very low. The effect of zinc supplementation on preterm birth, if causal, might reflect a reduction in maternal infection, a primary cause of prematurity. While further study would be needed to explore this possibility in detail, the overall public health benefit of zinc supplementation in pregnancy appears limited.

Chaffee, Benjamin W.; King, Janet C.

2013-01-01

264

Proceedings of the U.S. Geological Survey Seventh Biennial Geographic Information Science Workshop, Denver, Colorado, May 12-16, 2008  

USGS Publications Warehouse

The U.S. Geological Survey (USGS) Seventh Biennial Geographic Information Science (GIS) Workshop (USGS-GIS 2008) on May 12 through 16, 2008, at the Denver Federal Center in Denver, Colorado, is unique in that it brings together GIS professionals from all of the USGS disciplines across all regions, and focuses primarily on the needs and accomplishments of the USGS. The theme for the 2008 workshop, ?GIS for Tomorrow?s Challenges,? provides an opportunity for USGS GIS professionals to demonstrate how they have responded to the challenges set forth in the USGS Science Strategy. During this workshop, attendees will have an opportunity to present or demonstrate their work; develop their knowledge by attending hands-on workshops and presentations given by professionals from the USGS and other Federal agencies, GIS-related companies, and academia; and to network with other professionals to develop collaborative opportunities. In addition to participation in numerous workshops and presentations, attendees will have opportunities to listen to top-level managers from the USGS present updates and goals concerning the future of several USGS programs. Monday evening?s Star Guest presentation by Thomas Wagner, NSF Office of Polar Programs, and Paul Morin, Antarctic Geospatial Information Center, entitled ?Mapping all that is White: Antarctic Science and Operations Viewed Though Geospatial Data,? will be one of many valuable presentations. This Proceedings volume will serve as an activity reference for workshop attendees, as well as an archive of technical abstracts presented at the workshop. Author, co-author, and presenter names, affiliations, and contact information are listed with presentation titles with the abstracts. Some hands-on sessions are offered twice; in these instances, abstracts submitted for publication are presented in the proceedings on both days on which they are offered. All acronyms used in these proceedings are explained in the text of each abstract.

Edited by Helterbrand, Wm. Steve; Sieverling, Jennifer B.

2008-01-01

265

25 years of telepathology research: a bibliometric analysis  

PubMed Central

Background The first appearance of the word “telepathology” in a scientific paper can be tracked down to 1986, in a famous editorial of Ronald Weinstein. Since that paper, research in telepathology grew up developing different subfields, including static and dynamic telepathology and more recently virtual microscopy. The present work attempts an analysis of research in telepathology, starting from the tools provided by bibliometrics. Methods A query has been developed to extract papers related to telepathology and virtual microscopy, and it has been then submitted to Pubmed by means of Entrez Utilities functions. Results obtained in XML have been processed through ad-hoc developed PHP scripts, in order to extract data on Authors, countries, and keywords. Results On PubMed, 967 papers related to telepathology and virtual microscopy have been retrieved, which involved 2904 Authors; corresponding authors were from 37 countries. Of those authors, 2213 co-authored just one paper. Papers were published on 344 different journals, of which only 52 from the Pathology field. An analysis of papers per year has been also attempted, that demonstrates variable research output in time. Conclusions From the proposed analysis, telepathology seems to have been consistently studied, in time, by about 400 researchers, with occasional participation of many other people. Telepathology research seems also to have varied in time, although some peaks in paper publishing are certainly related to the proceedings of the European congress on telepathology series, when they have been published on journals. However, some clear sign appears that suggests research in traditional telepathology, after a peak in 2000, showed some decline until virtual microscopy became mainstream, topic that currently pushes research again. The low number of clinical trials calls for more randomized studies in telepathology, to enable evidence-based application.

2011-01-01

266

Cochrane Systematic Reviews of Chinese Herbal Medicines: An Overview  

PubMed Central

Objectives Our study had two objectives: a) to systematically identify all existing systematic reviews of Chinese herbal medicines (CHM) published in Cochrane Library; b) to assess the methodological quality of included reviews. Methodology/Principal Findings We performed a systematic search of the Cochrane Database of Systematic Reviews (CDSR, Issue 5, 2010) to identify all reviews of CHM. A total of fifty-eight reviews were eligible for our study. Twenty-one of the included reviews had at least one Traditional Chinese Medicine (TCM) practitioner as its co-author. 7 reviews didn't include any primary study, the remaining reviews (n?=?51) included a median of 9 studies and 936 participants. 50% of reviews were last assessed as up-to-date prior to 2008. The questions addressed by 39 reviews were broad in scope, in which 9 reviews combined studies with different herbal medicines. For OQAQ, the mean of overall quality score (item 10) was 5.05 (95% CI; 4.58-5.52). All reviews assessed the methodological quality of primary studies, 16% of included primary studies used adequate sequence generation and 7% used adequate allocation concealment. Of the 51 nonempty reviews, 23 reviews were reported as being inconclusive, while 27 concluded that there might be benefit of CHM, which was limited by the poor quality or inadequate quantity of included studies. 58 reviews reported searching a median of seven electronic databases, while 10 reviews did not search any Chinese database. Conclusions Now CDSR has included large numbers of CHM reviews, our study identified some areas which could be improved, such as almost half of included reviews did not have the participation of TCM practitioners and were not up-to-date according to Cochrane criteria, some reviews pooled the results of different herbal medicines and ignored the searching of Chinese databases.

Hu, Jing; Zhang, Junhua; Zhao, Wei; Zhang, Yongling; Zhang, Li; Shang, Hongcai

2011-01-01

267

A Dedicated Space Observatory For Time-domain Solar System Science  

NASA Astrophysics Data System (ADS)

Time-variable phenomena with scales ranging from minutes to decades have led to a large fraction of recent advances in many aspects of solar system science. We present the scientific motivation for a dedicated space observatory for solar system science. This facility will ideally conduct repeated imaging and spectroscopic observations over a period of 10 years or more. It will execute a selection of long-term projects with interleaved scheduling, resulting in the acquisition of data sets with consistent calibration, long baselines, and optimized sampling intervals. A sparse aperture telescope would be an ideal configuration for the mission, trading decreased sensitivity for reduced payload mass, while preserving spatial resolution. Ultraviolet capability is essential, especially once the Hubble Space Telescope retires. Specific investigations will include volcanism and cryovolcanism (on targets including Io, Titan, Venus, Mars, and Enceladus); zonal flow, vortices, and storm evolution on the giant planets; seasonal cycles in planetary atmospheres; mutual events and orbit determination of multiple small solar system bodies; auroral activity and solar wind interactions; and cometary evolution. The mission will produce a wealth of data products--such as multi-year time-lapse movies of planetary atmospheres--with significant education and public outreach potential. Existing and planned ground- and space-based facilities are not suitable for these time-domain optimized planetary dynamics studies for numerous reasons, including: oversubscription by astrophysical users, field-of-regard limitations, sensitive detector saturation limits that preclude bright planetary targets, and limited mission duration. The abstract author list is a preliminary group of scientists who have shown interest in prior presentations on this topic; interested parties may contact the lead author by 1 September to sign the associated Planetary Science Decadal Survey white paper or by 1 October to co-author the printed DPS poster.

Wong, Michael H.; Ádámkovics, M.; Benecchi, S.; Bjoraker, G.; Clarke, J. T.; de Pater, I.; Hendrix, A. R.; Marchis, F.; McGrath, M.; Noll, K.; Rages, K. A.; Retherford, K.; Smith, E. H.; Strange, N. J.

2009-09-01

268

The thermal structure of Tibetan crust and upper mantle (Invited)  

NASA Astrophysics Data System (ADS)

Almost 30 years ago I was a co-author of a paper that suggested the mantle lithosphere beneath Tibet had been removed by a convective instability caused by shortening. Surface wave tomography carried out by a number of groups now clearly shows that this proposal is wrong, and that cold lithosphere is still present everywhere beneath the plateau. It has not been removed by delamination, and, at least in the northern part, the mantle beneath the Moho is hotter than that at greater depths. Furthermore the thickness of the lithosphere, of ~300 km, is greater than that beneath any other continental region and strongly suggests that the lithosphere has been shortened. The Iranian plateau shows similar features on a smaller scale. This unexpected behaviour can be understtod if the density of the lithosphere is a function of both its temperature and its composition. Mantle nodules brought up by melts show that much of the continental lithosphere has been depleted by melt removal, leaving a harzburgite whose density is substantially less than that of the fertile mantle. The trace element composition of basaltic rocks from northern Tibet shows that their source rocks were harzburgites that had been enriched by a few percent of metasomatic melt. The melting is probably occurring in the shallow mantle beneath the Moho, where the shear wave velocity is low and where the temperature is increasing because of downward conduction of heat generated by radioactive decay within the crust. This behaviour will occur wherever the thickness of the crust and lithosphere have been increased by shortening, and is likely to have been even more important than it is now at earlier times in the Earth's history.

McKenzie, D. P.; Priestley, K. F.

2010-12-01

269

Validation study of villous atrophy and small intestinal inflammation in Swedish biopsy registers  

PubMed Central

Background Small intestinal biopsy with villous atrophy (VA) is the gold standard for the diagnosis of celiac disease (CD). We validated VA (Marsh 3) and small intestinal inflammation without VA (Marsh 1+2) in Swedish regional biopsy registers. Methods All pathology departments in Sweden (n = 28) were searched to identify individuals with VA or duodenal/jejunal inflammation. The validation consisted of blinded examination of biopsy samples, manual review of biopsy reports, web surveys, and patient chart reviews of 121 individuals with VA and 39 with inflammation. Results We identified 29,148 individuals with VA and 13,446 individuals with inflammation. In a blinded examination, Swedish pathologists correctly classified 90% of biopsies with VA. Manual screening of 1,534 biopsy reports (performed by co-author JFL and a research assistant) found that comorbidity other than CD was rare. IBD was the most common comorbidity and occurred in 0.3% of biopsies with VA (1.6% in inflammation). Among 114 patients with VA and available data, 108 (95%) had a clinical diagnosis of CD. 79% of the validated individuals with VA and 64% of those with inflammation had documented gastrointestinal symptoms prior to biopsy. 88% of the validated individuals with VA had positive CD serology before their first biopsy. 172/180 (96%) of Swedish gastroenterologists and 68/68 (100%) of pediatricians perform a small intestinal biopsy in at least 9 out of 10 individuals prior to diagnosis of CD. Conclusion Regional biopsy data are feasible to identify individuals with CD and small-intestinal inflammation. The specificity of CD is high in villous atrophy.

2009-01-01

270

In situ analysis of aqueous structure and adsorption at fluorocarbon, hydrocarbon and mineral surfaces  

NASA Astrophysics Data System (ADS)

Altering and controlling the properties of solid surfaces in aqueous or other liquid phase environments has been a sought after objective for decades. With the discovery of chemisorbed self-assembled monolayers, this dream has become a reality. Oxide and metal surfaces can now be readily coated with an array of commercially available products to produce a desired fnctionality. The presence of these coatings on solid surfaces affects properties of the interfacial region by altering interfacial electrostatic fields, changing the structure of interfacial water molecules and altering the interactions of adsorbed species. This dissertation reports on in situ studies of adsorption at several solid/aqueous interfaces using vibrational sum-frequency spectroscopy, a surface specific technique. These studies are augmented by the use of atomic force microscopy and contact angle goniometry to characterize the prepared surfaces and their interactions with adsorbates. The studies investigate how changes in the surface structure and chemistry, as well as the bulk aqueous phase, affect interfacial structure. The studies within are primarily focused on the interactions of water with bare and functionalized fused silica and the relationship between the aqueous phase composition and the structure of fluorocarbon and hydrocarbon self-assembled monolayers. The variations in aqueous structure are then examined in detail using ionic strength controlled experiments to understand the direct interactions of water hydrophobically coated silica. This analysis is followed by an investigation of the competitive adsorption of methanol and water at fluorocarbon and hydrocarbon monolayers which show spectroscopic signatures of the interaction strength between fluorocarbons and hydrocarbons. Further studies are performed using butylammonium chloride to verify these spectroscopic signatures and reveal different molecular structures of adsorbed species at chemically different hydrophobic surfaces. Lastly, specific ion effects on the CaF2/water interface are shown using equilibrium and time-resolved sum-frequency spectroscopy. The results of all these studies have implications for an array of surface chemical applications from mineral flotation to biocompatibility. This dissertation includes previously published co-authored material.

Hopkins, Adam Justin

271

New directions for Rayleigh-Taylor mixing.  

PubMed

We study the Rayleigh-Taylor (RT) mixing layer, presenting simulations in agreement with experimental data. This problem is an idealized subproblem of important scientific and engineering problems, such as gravitationally induced mixing in oceanography and performance assessment for inertial confinement fusion. Engineering codes commonly achieve correct simulations through the calibration of adjustable parameters. In this sense, they are interpolative and not predictive. As computational science moves from the interpolative to the predictive and reduces the reliance on experiment, the quality of decision making improves. The diagnosis of errors in a multi-parameter, multi-physics setting is daunting, so we address this issue in the proposed idealized setting. The validation tests presented are thus a test for engineering codes, when used for complex problems containing RT features. The RT growth rate, characterized by a dimensionless but non-universal parameter ?, describes the outer edge of the mixing zone. Increasingly accurate front tracking/large eddy simulations reveal the non-universality of the growth rate and agreement with experimental data. Increased mesh resolution allows reduction in the role of key subgrid models. We study the effect of long-wavelength perturbations on the mixing growth rate. A self-similar power law for the initial perturbation amplitudes is here inferred from experimental data. We show a maximum ±5% effect on the growth rate. Large (factors of 2) effects, as predicted in some models and many simulations, are inconsistent with the experimental data of Youngs and co-authors. The inconsistency of the model lies in the treatment of the dynamics of bubbles, which are the shortest-wavelength modes for this problem. An alternative theory for this shortest wavelength, based on the bubble merger model, was previously shown to be consistent with experimental data. PMID:24146006

Glimm, James; Sharp, David H; Kaman, Tulin; Lim, Hyunkyung

2013-10-21

272

Resorption Rate Tunable Bioceramic: Si, Zn-Modified Tricalcium Phosphate  

SciTech Connect

This dissertation is organized in an alternate format. Several manuscripts which have already been published or are to be submitted for publication have been included as separate chapters. Chapter 1 is a general introduction which describes the dissertation organization and introduces the human bone and ceramic materials as bone substitute. Chapter 2 is the background and literature review on dissolution behavior of calcium phosphate, and discussion of motivation for this research. Chapter 3 is a manuscript entitled ''Si,Zn-modified tricalcium phosphate: a phase composition and crystal structure study'', which was published in ''Key Engineering Materials'' [1]. Chapter 4 gives more crystal structure details by neutron powder diffraction, which identifies the position for Si and Zn substitution and explains the stabilization mechanism of the structure. A manuscript entitled ''Crystal structure analysis of Si, Zn-modified Tricalcium phosphate by Neutron Powder Diffraction'' will be submitted to Biomaterials [2]. Chapter 5 is a manuscript, entitled ''Dissolution behavior and cytotoxicity test of Si, Zn-modified tricalcium phosphate'', which is to be submitted to Biomaterials [3]. This paper discusses the additives effect on the dissolution behavior of TCP, and cytotoxicity test result is also included. Chapter 6 is the study of hydrolysis process of {alpha}-tricalcium phosphate in the simulated body fluid, and the phase development during drying process is discussed. A manuscript entitled ''Hydrolysis of {alpha}-tricalcium phosphate in simulated body fluid and phase transformation during drying process'' is to be submitted to Biomaterials [4]. Ozan Ugurlu is included as co-authors in these two papers due to his TEM contributions. Appendix A is the general introduction of the materials synthesis, crystal structure and preliminary dissolution result. A manuscript entitled ''Resorption rate tunable bioceramic: Si and Zn-modified tricalcium phosphate'' was published in Ceramic Engineering and Science Proceedings (the 29th International Conference on Advanced Ceramics and Composites - Advances in Bioceramics and Biocomposites) [5].

Xiang Wei

2006-08-09

273

Doped Cobaltites: Phase Separation, Intergranular Giant Magnetoresistance, and Glassy Transport  

NASA Astrophysics Data System (ADS)

We have used magnetometry, transport, Nuclear Magnetic Resonance (NMR), Small Angle Neutron Scattering (SANS), and Transmission Electron Microscopy (TEM) to investigate magnetoelectronic phase separation in La1-xSrxCoO3. This material shows a crossover from a glassy phase at low doping to ferromagnetism (F) above x = 0.18, as well as a simultaneous transition from insulator to metal. NMR confirms magnetic phase inhomogeneity with low spin non-magnetic, glassy, and F regions coexisting spatially. SANS reveals 25 å F clusters forming in a matrix of non-F insulator at low doping, eventually leading to a percolation transition to long-range F order at x > 0.18. In single crystals, this formation of isolated clusters leads to a hysteretic negative MagnetoResistance (MR) at low temperatures, which has field, temperature, and doping dependencies consistent with an intergranular Giant MagnetoResistance (GMR) effect. We argue that this system is a naturally forming analog to the artificial structures fabricated by depositing nanoscale F particles in a metallic or insulating matrix, i.e. this material displays an intergranular GMR effect without the deliberate introduction of chemical interfaces. The formation of nanoscopic F clusters also gives rise to glassy transport phenomena that are reminiscent of relaxor ferroelectrics. The transport properties show a bifurcation of field cooled and zero field cooled temperature traces, slow response to changes in magnetic fields, and, most notably, a ``waiting time'' effect that can be observed directly in the resistivity. Acknowledgements: ACS Petroleum Research Fund, UMN NSF MRSEC. Co-Authors: J. Wu, J. Lynn, C. Glinka, J. Burley, H. Zheng, J. Mitchell, W. Moulton, M. Hoch, P. Kuhns, A. Reyes, C. Perrey, N. Munoz, R. Thompson and B. Carter.

Leighton, Chris

2005-03-01

274

Mollie stevens smart (1916-2012).  

PubMed

Presents an obituary for Mollie Stevens Smart (1916-2012). Mollie attended the University of Toronto, from which she graduated with honors in psychology at age 20 in 1936. She studied and worked at the Merrill-Palmer Institute in Detroit, earning a master's degree in child development from the University of Michigan in 1941. She earned her doctorate in educational psychology at the University of Delhi in 1969. An author, teacher, and mentor, Mollie won Fulbright research grants to India and New Zealand and lectured in the United States, India, New Zealand, Canada, and China. She wrote 26 books, most co-authored with her husband, Russell (Rus) C. Smart. Beginning in the 1940s, when Freudian theory had a strong grip on the popular view of child development, the books placed the developing child in the context of family and community systems. The Smarts' best-selling college textbook Children: Development and Relationships (1967, 1973, 1977, 1982) was based on the theories of Erik Erikson and Jean Piaget. Mollie was a member of the American Psychological Association throughout her professional career and held memberships also in the Society for Research in Child Development, the National Council on Family Relations, the Groves Conference on Marriage and Family, and the Fulbright Association. After moving to Ridgefield, Washington, in 2003 with her daughter Ellen following Rus's death in 1996, she applied her great knowledge to advise a community-based organization that serves the needs of new babies born into destitute families. Mollie died at home in Ridgefield on October 22, 2012, at age 96. (PsycINFO Database Record (c) 2013 APA, all rights reserved). PMID:24016121

Smart, Laura S; Prochaska, James O

2013-09-01

275

Magma generation and differentiation in the terrestrial planets - a review of the contributions of Michael J. O'Hara  

NASA Astrophysics Data System (ADS)

During the course of the 20th century Earth Scientists argued, seemingly incessantly, about the processes of magma generation and differentiation within the Earth, Moon and other planetary bodies. Whilst N.L. Bowen's (1928) classic publication "The evolution of the Igneous Rocks " undoubtedly represents a benchmark in our understanding, it was not until the mid 1960s that the complexity of these processes was appreciated fully. The fact that we are still debating many of the key issues, forty years later, reflects the scale of the problem; each new step in our understanding seems to generate more questions! 2003 marks the 70th birthday of Michael J. O'Hara, and the 35th anniversary of the publication of two of his classic papers, which influenced the thinking of a generation of petrologists: (1) "The bearing of phase equilibria studies in synthetic and natural systems on the origin of basic and ultrabasic rocks" [Earth Sci. Rev., 4, 69-133; 1968]; (2) "Are ocean floor basalts primary magmas?" [Nature, 220, 683-686; 1968]. Since 1960, Mike has been the first, sole or joint co-author on over 120 publications, directly or indirectly related to magma generation and differentiation. His contributions have encompassed a diverse range of topics including: high P-T experimental petrology, the CMAS projection, the origin and evolution of basic and ultrabasic magmas, upper mantle petrology and dynamics, geothermometry-geobarometry of mantle rocks, RTF magma chambers and the mechanisms of dyke intrusion. Mike played a leading role in the Lunar Science Programme in the early 1970s and is still "stirring the lunar pot" [3]. (3) "Flood Basalts, Basalt Floods or Topless Bushvelds? Lunar Petrogenesis Revisited" [J.Petrology 41, 1545-1651; 2000].

Wilson, M.

2003-04-01

276

Bibliography of NASA-related publications on wind turbine technology 1973-1995  

NASA Astrophysics Data System (ADS)

A major program of research and development projects on wind turbines for generating electricity was conducted at the NASA Lewis Research Center from 1973 to 1988. Most of these projects were sponsored by the U.S. Department of Energy (DOE), as a major element of its Federal Wind Energy Program. One other large-scale wind turbine project was sponsored by the Bureau of Reclamation of the Department of Interior (DOI). The peak years for wind energy work at Lewis were 1979-80, when almost 100 engineers, technicians, and administrative personnel were involved. From 1988 their conclusion in 1995, NASA wind energy activities have been directed toward the transfer of technology to commercial and academic organizations. Wind energy activities at NASA can be divided into two broad categories which are closely related and often overlapping: (1) Designing, building, and testing a series of 12 large-scale, experimental, horizontal-axis wind turbines (HAWT's); and (2) conducting supporting research and technology (SR&T) projects. The purpose of this bibliography is to assist those active in the field of wind energy in locating the technical information they need on wind power planning, wind loads, turbine design and analysis, fabrication and installation, laboratory and field testing, and operations and maintenance. This bibliography contains approximately 620 citations of publications by over 520 authors and co-authors. Sources are: (1) NASA reports authored by government grantee, and contractor personnel, (2) papers presented by attendees at NASA-sponsored workshops and conferences, (3) papers presented by NASA personnel at outside workshops and conferences, and (4) outside publications related to research performed at NASA/ DOE wind turbine sites.

Spera, David A.

1995-04-01

277

The interlayer exchange interaction in multilayer magnetic systems Fe/Cr/Fe (Review Article)  

NASA Astrophysics Data System (ADS)

Upsurge of interest in the study of magnetic multilayer structures began in the mid-80s of the twentieth century and was caused by significant progress in the technology of ultrathin metallic films. For a few years, phenomena extremely interesting from both fundamental and applied point of view have been found in these structures: the antiparallel arrangement of the ferromagnetic layers, giant magnetoresistance, alternating oscillations of the interlayer exchange, noncollinear interlayer ordering of magnetic moments. All this and the closeness of technologies, used for the sample preparation to those traditionally applied in microelectronics, promised great potentials for developing compact magnetic field sensors, non-volatile memory for electronic devices, etc. To date, some of these features are already implemented in the mass commercial products (e.g., read heads of hard drives), and others still wait in the wings. The Nobel Prize, awarded in 2007 to A. Fert and P. Grünberg with the words ``For the discovery of the giant magnetoresistance effect'' can be considered as recognition of the importance of the discoveries made in this area. A special place in these works was given to the Fe/Cr/Fe system. It is there for the first time almost all of the most interesting phenomena were observed that caused a boom in the physics of magnetic films. However, until recently the nature of the exchange interaction in this system aroused great debates. First of all, it was due to a complex phase diagram of chromium spacer and strong influence on the sample properties of technological perfection of its structure. Here we made a brief review of the main experimental and theoretical studies on the multilayer systems Fe/Cr/Fe, as well as recounted the results of our own studies (performed with a group of co-authors), which greatly clarify the mechanism of the interlayer interaction in this system.

Kreines, N. M.; Kholin, D. I.; Demokritov, S. O.

2012-09-01

278

Real-time Science and Educational Collaboration Online from the Indian Ocean  

NASA Astrophysics Data System (ADS)

During Summer of 2007, scientists and students (via the web) jointly participated in research during the Ninety East Ridge Expedition (cruise KNOX06RR) . Staff organizers from Joint Oceanographic Institutions" JOI Learning and the Integrated Ocean Drilling Program planned and implemented an interactive website to allow students to directly participate with scientists during the site survey aboard the R/V Roger Revelle. Dr. Will Sager and middle school teacher Rory Wilson collaborated daily during the scientific expedition with science team, ship crew and students. From the outset, students were involved and helped to guide the program; this included coming up with the website name and initial design work. Communication with students included the website, individual and group emails and video conferences with student groups. Seven secondary schools from the USA, Europe, India and Thailand participated actively in the project from June to August. Students viewed daily updates on the website, sent in answers for weekly science challenge questions, and interacted with scientists and crew. Student participants learned about navigation, geophysics and petrology, as well as ship operations and technology. Students and educators tracked the expedition's progress in a multi-media environment. Website statistics were recorded; participation began well and increased during the expedition as more people became engaged with the website. All of the crew and scientists wrote self-profiles to help students learn about the range of ocean careers; several of the scientists and graduate students on board wrote or co- authored website articles for students. During this presentation, we will explore and review the major features of the outreach program using the Sea90e website to demonstrate how this real-time interaction engages students in science learning. We will discuss the benefits of collaboration for science and education in our "classroom at sea."

Wilson, R. H.; Sager, W. W.

2007-12-01

279

Titan's Mid-latitude Clouds  

NASA Astrophysics Data System (ADS)

In the first few years of spatially resolved observations of Titan's tropospheric methane clouds (2001-2003) all of the clouds were clustered in the south polar region. This time period coincided with the southern summer solstice (October 2002) and these south polar clouds are almost certainly a seasonal phenomenon. Starting in December 2003 we began seeing clouds in a narrow latitude range centered at 40°S latitude. In Roe et al. (2005a) we published this initial discovery and speculated that the clouds might be due either to changes in the seasonal circulation pattern or a process linked to surface geography. Further observations soon revealed that the clouds were significantly clustered over one region of longitude (near 350°W), strongly suggesting a geographically controlled origin (Roe et al. 2005b), although Cassini observations suggest a circulation-induced convergence origin (Griffith et al. 2005). The actual answer is most likely a combination of geographic surface effects with the atmospheric circulation. We report here on our continuing ground-based observation campaign, including observations on 65 nights in the 2006-2007 apparition with the Gemini 8-m telescope. With two more years of observations since the data shown in Roe et al. (2005b) we now have much firmer conclusions with respect to the spatial distribution and temporal characteristics of the mid-latitude clouds. We will present our latest understanding of Titan's mid-latitude clouds given the entire dataset now available to us. References Griffith, C.A., & 26 co-authors 2005. Science, 310, 474. Roe, H.G., A.H. Bouchez, C.A. Trujillo, E.L. Schaller, & M.E. Brown 2005a. ApJL, 618, 49. Roe, H.G., M.E. Brown, E.L. Schaller, A.H. Bouchez, & C.A. Trujillo 2005b. Science, 310, 477. This work is supported by NASA under Grant #NNX07AK74G issued through the Planetary Astronomy Program.

Roe, Henry G.; Schaller, E. L.; Trujillo, C. A.; Brown, M. E.

2007-10-01

280

Countermeasures to the US National Missile Defense  

NASA Astrophysics Data System (ADS)

One of the key technical questions about national missile defenses is whether they can be expected to work under real-world conditions if the attacker takes steps to defeat the defense. This talk will discuss steps that an emerging missile state could take to confuse, overwhelm, or otherwise defeat the planned US NMD system developed by the Clinton administration. It will consider three such ``countermeasures" that would be within the technical capability of a state that could develop and deploy a long-range missile capable of reaching the United States, which is the threat the NMD system is intended to defend against. The talk will be based on the April 2000 report ``Countermeasures: A Technical Evaluation of the Operational Effectiveness of the Planned US National Missile Defense System," which was co-authored by the speaker and 10 other physicists and engineers. Although the talk will refer to the ground-based NMD system under development, the conclusions are applicable to any mid-course NMD system using hit-to-kill infrared-homing interceptors, regardless of their basing mode. The three countermeasures considered are: (1) biological weapons deployed on 100 or more small bomblets, or submunitions, that would be released shortly after the boost phase; (2) nuclear warheads with anti-simulation balloon decoys, in which the attacker disguises the warhead by enclosing it in an aluminum-coated mylar balloon and releasing it along with a large number of otherwise similar but empty balloons; and (3) nuclear warheads with cooled shrouds, in which the attacker foils the kill vehicle's homing process by covering each nuclear warhead with a double-walled cone containing liquid nitrogen.

Gronlund, Lisbeth

2001-04-01

281

Quantifying Air Quality Co-Benefits from Lower-Carbon Electricity Production  

NASA Astrophysics Data System (ADS)

Over the past few years, many U.S. states have developed climate policies aimed at reducing carbon emissions. Depending on how such policies are designed, significant co-benefits to local and regional air quality may also result. Our work uses Wisconsin as a case study to evaluate two climate policies put forward by an official state task force. We develop an advanced methodology to quantify electricity emissions from a multi-pollutant perspective and compare the air quality impacts of each policy option. We present results from the MyPower electricity dispatch model, developed by co-author Paul Meier, which are then used to assess spatial emission changes for evaluation with the EPA Community Multiscale Air Quality (CMAQ) model. We focus on potential changes to ozone (O3), sulfate aerosol (SO4), and nitrate aerosol (NO3) concentrations associated with future changes in nitrogen oxide (NOx) and sulfur dioxide (SO2) emissions from electricity generating units (EGUs). Because each power plant has significant and site-specific air quality impacts, we evaluate emission changes on a unit-by-unit basis. Wisconsin EGU emissions from each scenario are merged with non-EGU source emissions from the EPA 2002 National Emissions Inventory (2002 NEI) to produce the total emission values for all anthropogenic and biogenic sources. For each scenario, CMAQ was run for July 2003 with a 12 x 12 km horizontal resolution over the Great Lakes region and was driven with meteorology from the Weather Research and Forecasting (WRF) model. Analysis of model output quantifies the relative changes in health-relevant criteria pollutants from each emission scenario. Air pollution concentrations and baseline MyPower emission estimates are also evaluated against observations for quality control and model evaluation purposes. We find that local changes in Wisconsin EGU emissions produce a regional change in air quality extending across states downwind, with sulfate aerosol exhibiting the greatest response.

Plachinski, S. D.; Holloway, T.; Meier, P.; Oberman, J.

2010-12-01

282

A taxonomy for community-based care programs focused on HIV/AIDS prevention, treatment, and care in resource-poor settings.  

PubMed

Community-based care (CBC) can increase access to key services for people affected by HIV/AIDS through the mobilization of community interests and resources and their integration with formal health structures. Yet, the lack of a systematic framework for analysis of CBC focused on HIV/AIDS impedes our ability to understand and study CBC programs. We sought to develop taxonomy of CBC programs focused on HIV/AIDS in resource-limited settings in an effort to understand their key characteristics, uncover any gaps in programming, and highlight the potential roles they play. Our review aimed to systematically identify key CBC programs focused on HIV/AIDS in resource-limited settings. We used both bibliographic database searches (Medline, CINAHL, and EMBASE) for peer-reviewed literature and internet-based searches for gray literature. Our search terms were 'HIV' or 'AIDS' and 'community-based care' or 'CBC'. Two co-authors developed a descriptive taxonomy through an iterative, inductive process using the retrieved program information. We identified 21 CBC programs useful for developing taxonomy. Extensive variation was observed within each of the nine categories identified: region, vision, characteristics of target populations, program scope, program operations, funding models, human resources, sustainability, and monitoring and evaluation strategies. While additional research may still be needed to identify the conditions that lead to overall program success, our findings can help to inform our understanding of the various aspects of CBC programs and inform potential logic models for CBC programming in the context of HIV/AIDS in resource-limited settings. Importantly, the findings of the present study can be used to develop sustainable HIV/AIDS-service delivery programs in regions with health resource shortages. PMID:23594416

Rachlis, Beth; Sodhi, Sumeet; Burciul, Barry; Orbinski, James; Cheng, Amy H Y; Cole, Donald

2013-04-16

283

Amaranth oil application for coronary heart disease and hypertension.  

PubMed

Cardiovascular disease (CVD) is the Nation's leading killer for both men and women among all racial and ethnic groups. Development and progression of CVD is linked to the presence of risk factors such as hyperlipidemia, hypertension, obesity, and diabetes mellitus. It is known that cholesterol is an indicator of increased risk of heart attack and stroke. Low-density cholesterol (LDL) above 130 mg/dl high-density cholesterol (HDL) cholesterol below 35 mg/dl and total blood cholesterol above 200 mg/dl are indicators of problematic cholesterol. Proper ranges of cholesterol are important in the prevention of CVD. It has been suggested that a reduction in the consumption of saturated and an increase in unsaturated fatty acids is beneficial and prevents CVD. Amaranth grain contains tocotrienols and squalene compounds, which are known to affect cholesterol biosynthesis. The cholesterol precursors squalene, lanosterol and other methyl sterols, reflect cholesterol synthesis 123, whereas plant sterols and cholestanol, a metabolite of cholesterol, reflect the efficiency of cholesterol absorption in normal and hyperlipidemic populations 456. Qureshi with co-authors 7 showed that feeding of chickens with amaranth oil decreases blood cholesterol levels, which are supported by the work of others 8. Previously, we have shown that Amaranth oil modulates the cell membrane fluidity 9 and stabilized membranes that could be one reason as to why it is beneficial to those who consume it. It is known that in hypertension, the cell membrane is defective and hence, the movement of the Na and K ions across the cell membranes could defective that could contribute to the development of increase in blood pressure. Based on these properties of amaranth oil we hypothesize that it could be of significant benefit for patients with CVD. PMID:17207282

Martirosyan, Danik M; Miroshnichenko, Lidia A; Kulakova, Svetlana N; Pogojeva, Ala V; Zoloedov, Vladimir I

2007-01-05

284

Amaranth oil application for coronary heart disease and hypertension  

PubMed Central

Cardiovascular disease (CVD) is the Nation's leading killer for both men and women among all racial and ethnic groups. Development and progression of CVD is linked to the presence of risk factors such as hyperlipidemia, hypertension, obesity, and diabetes mellitus. It is known that cholesterol is an indicator of increased risk of heart attack and stroke. Low-density cholesterol (LDL) above 130 mg/dl high-density cholesterol (HDL) cholesterol below 35 mg/dl and total blood cholesterol above 200 mg/dl are indicators of problematic cholesterol. Proper ranges of cholesterol are important in the prevention of CVD. It has been suggested that a reduction in the consumption of saturated and an increase in unsaturated fatty acids is beneficial and prevents CVD. Amaranth grain contains tocotrienols and squalene compounds, which are known to affect cholesterol biosynthesis. The cholesterol precursors squalene, lanosterol and other methyl sterols, reflect cholesterol synthesis [1-3], whereas plant sterols and cholestanol, a metabolite of cholesterol, reflect the efficiency of cholesterol absorption in normal and hyperlipidemic populations [4-6]. Qureshi with co-authors [7] showed that feeding of chickens with amaranth oil decreases blood cholesterol levels, which are supported by the work of others [8]. Previously, we have shown that Amaranth oil modulates the cell membrane fluidity [9] and stabilized membranes that could be one reason as to why it is beneficial to those who consume it. It is known that in hypertension, the cell membrane is defective and hence, the movement of the Na and K ions across the cell membranes could defective that could contribute to the development of increase in blood pressure. Based on these properties of amaranth oil we hypothesize that it could be of significant benefit for patients with CVD.

Martirosyan, Danik M; Miroshnichenko, Lidia A; Kulakova, Svetlana N; Pogojeva, Ala V; Zoloedov, Vladimir I

2007-01-01

285

The CloudSat Education Network: Significant Collaborative Research Between Students and Scientists  

NASA Astrophysics Data System (ADS)

The CloudSat Education Network (CEN) is the primary education and public outreach component of the CloudSat mission. Approximately 116 schools in 16 countries around the world participate in the CEN, and are recruited from schools in the GLOBE program. Students and teachers in the CEN make atmospheric observations of temperature, precipitation, and crucially, of cloud type and cloud cover amount (including photographs of cloud observations), using a modified GLOBE Atmosphere protocol as a guide for observations. CEN observations are taken coincident with CloudSat overpasses, providing coincident spaceborne- and student surface observations. This puts students and teachers participating in the CEN at the forefront of scientific research as directly contributing partners in a collaborative research endeavor. CEN participants make extensive use of the CloudSat/CEN webpage, which is the primary data entry portal for the CEN. Data collected from CEN students is analyzed by CloudSat scientists for quality control purposes, as well as for use in CloudSat-related research. The webpage also provides students with CloudSat overpass dates and times, as well as CEN-specific updates, and articles about CEN projects distributed through a quarterly newsletter. Besides the newsletter, active CEN schools receive periodic visits from CloudSat scientists, providing an opportunity for students and teachers to interact directly with the scientific community. Results from completed student research include an investigation of the effect of different amounts of cloud cover on locally-grown mushroom crops in Thailand, while CloudSat-directed research using student data includes an analysis of the CloudSat cloud classification algorithm using student-collected data as a ground-truth dataset. The results of this latter study are in the process of publication with participating students and teachers listed as co-authors.

Rogers, M. A.; Vane, D.

2009-12-01

286

nanoHUB.org - Towards On-Line Simulation for Materials and Nanodevices by Design  

NASA Astrophysics Data System (ADS)

Challenges in nanoelectronics are the merging notions of material and device. Device lengths have reached the nanometer scale, where material properties are defined. Detailed atomic composition such as strain, interface, doping, and size fluctuations need to be treated. Here the material science and device engineering communities meet on the common ground of quantum mechanics. Success will depend on bridging language and approach barriers between communities. The development of accepted community software will be a significant step.One element of such codes is the NanoElectronic MOdeling Tool. NEMO 3-D enables the computation of strain and electronic structure in an atomistic basis for over 60 and 23 million atoms, corresponding to volumes of (107nm)^3 and (77nm)^3, respectively. NEMO 3-D runs on a serial and parallel platforms, local cluster computers as well as the NSF Teragrid. About 400,000 atoms are treated efficiently on a single 32bit CPU. NEMO uses an atomistic valence force field method (strain) and the empirical tight binding method (electronic structure). Quantitative simulations for quantum dots in the InAs/GaAs and Si/SiGe material systems have been performed. The Network for Computational Nanotechnology (NCN) is in the process of developing new community and research codes for the analysis of nano-(electronic/mechanical/bio) devices. These tools are hosted on http://nanohub.org for on-line simulation use free-of-charge. Last year over 1,000 people performed about 64,000 simulations. 2,200 others viewed seminars and nanotechnology curriculum items. nanoHUB is being developed as a community resource that encourages on-line simulation, collaborations and nanotechnology education. Co-author: Mark S. Lundstrom

Klimeck, Gerhard; Lundstrom, Mark

2005-03-01

287

Probing local conformation and dynamics of molecular complexes using phase-selective fluorescence correlation and coherence spectroscopy  

NASA Astrophysics Data System (ADS)

When two or more fluorescent chromophores are closely spaced in a macromolecular complex, dipolar coupling leads to delocalization of the excited states, forming excitons. The relative transition frequencies and magnitudes are sensitive to conformation, which can then be studied with optical spectroscopy. Non-invasive fluorescence spectroscopy techniques are useful tools for the study of dilute concentrations of such naturally fluorescent or fluorescently labeled biological systems. This dissertation presents two phase-selective fluorescence spectroscopy techniques for the study of dynamical processes in bio-molecular systems across a wide range of timescales. Polarization-modulated Fourier imaging correlation spectroscopy (PM-FICS) is a novel phase-selective fluorescence spectroscopy for simultaneous study of translational and conformational dynamics. We utilize modulated polarization and intensity gratings with phase-sensitive signal collection to monitor the collective fluctuations of an ensemble of fluorescent molecules. The translational and conformational dynamics can be separated and analyzed separately to generate 2D spectral densities and joint probability distributions. We present results of PM-FICS experiments on DsRed, a fluorescent protein complex. Detailed information on thermally driven dipole-coupled optical switching pathways is found, for which we propose a conformation transition mechanism. 2D phase-modulation electronic coherence spectroscopy is a third-order nonlinear spectroscopy that uses collinear pulse geometry and acousto-optic phase modulation to isolate rephasing and nonrephasing contributions to the collected fluorescence signal. We generate 2D spectra, from which we are able to determine relative dipole orientations, and therefore structural conformation, in addition to detailed coupling information. We present results of experiments on magnesium tetraphenylporphyrin dimers in lipid vesicle bilayers. The 2D spectra show clearly resolved diagonal and off-diagonal features, evidence of exciton behavior. The amplitudes of the distinct spectral features change on a femtosecond timescale, revealing information on time-dependent energy transfer dynamics. This dissertation includes co-authored and previously published material.

Lott, Geoffrey Adam

288

Science of Global Climate Modeling: Confirmation from Discoveries on Mars  

NASA Astrophysics Data System (ADS)

As early as 1993, analysis of obliquity changes on Mars revealed irregular cycles of high excursion, over 45°1. Further obliquity analyses indicated that insolation and climatic conditions vary with time, with the four most recent episodes of obliquity >45° occurring about 5.5, 8, 9, and 15 My.2 Various researchers applied global climate models, using Martian parameters and obliquity changes. The models (independent of Martian geomorphological observations) indicate exceptional climate conditions during the high-obliquity episodes at >45°3,4, with localized massive ice deposition effects east of Hellas and on the west slopes of Tharsis.5 At last year’s DPS my co-authors and I detailed evidence of unusual active glaciation in Greg crater, near the center of the predicted area of ice accumulation during high obliquity.6 We found that the timescale of glacial surface layer activity matches the general 5-15 My timescale of the last episodes of high obliquity and ice deposition. Radar results confirm ice deposits in debris aprons concentrated in the same area.7 Less direct evidence has also been found for glacial ice deposits in the west Tharsis region.8 Here I emphasize that if the models can be adjusted to Mars and then successfully indicate unusual, specific features that we see there, it is an argument for the robustness of climate modeling in general. In recent years we have see various public figures casting doubt on the validity of terrestrial global modeling. The successful match of Martian climate modeling with direct Martian geological and chronometric observations provides an interesting and teachable refutation of the attacks on climate science. References: 1. Science 259:1294-1297; 2. LPSC XXXV, Abs. 1600; 3. Nature 412:411-413; 4. Science 295:110-113; 5. Science 311:368-371; 6. EPSC-DPS Abs. 1394; 7. Science 322:1235-1238; 8. Nature 434:346-351.

Hartmann, William K.

2012-10-01

289

How Are Academic Age, Productivity and Collaboration Related to Citing Behavior of Researchers?  

PubMed Central

References are an essential component of research articles and therefore of scientific communication. In this study we investigate referencing (citing) behavior in five diverse fields (astronomy, mathematics, robotics, ecology and economics) based on 213,756 core journal articles. At the macro level we find: (a) a steady increase in the number of references per article over the period studied (50 years), which in some fields is due to a higher rate of usage, while in others reflects longer articles and (b) an increase in all fields in the fraction of older, foundational references since the 1980s, with no obvious change in citing patterns associated with the introduction of the Internet. At the meso level we explore current (2006–2010) referencing behavior of different categories of authors (21,562 total) within each field, based on their academic age, productivity and collaborative practices. Contrary to some previous findings and expectations we find that senior researchers use references at the same rate as their junior colleagues, with similar rates of re-citation (use of same references in multiple papers). High Modified Price Index (MPI, which measures the speed of the research front more accurately than the traditional Price Index) of senior authors indicates that their research has the similar cutting-edge aspect as that of their younger colleagues. In all fields both the productive researchers and especially those who collaborate more use a significantly lower fraction of foundational references and have much higher MPI and lower re-citation rates, i.e., they are the ones pushing the research front regardless of researcher age. This paper introduces improved bibliometric methods to measure the speed of the research front, disambiguate lead authors in co-authored papers and decouple measures of productivity and collaboration.

Milojevic, Stasa

2012-01-01

290

Different Views of the Grand Canyon  

NASA Astrophysics Data System (ADS)

Each year the spectacular scenery of the Grand Canyon of Arizona awes its more than 4,000,000 visitors. Just as its enormous scale dwarfs our human sense of space, its geology also dwarfs our human sense of time. Perhaps here, more than anywhere else on the planet, we can experience a sense of ``Deep Time.'' The colorful rocks exposed in the vertical walls of the canyon display a span of 1.8 billion years of Earth's history [Beus and Morales, 2003]. But wait! There is a different view! According to Vail [2003], this time span is only 6,000 years and the Grand Canyon and its rocks are a record of the Biblical 6 days of creation and Noah's flood. During a visit to Grand Canyon, in August 2003, I learned that Vail's book, Grand Canyon: A Different View, is being sold within the National Park. The author and compiler of Grand Canyon: A Different View is a Colorado River guide who is well acquainted with the Grand Canyon at river level. He has produced a book with an attractive layout and beautiful photographs. The book is remarkable because it has 23 co-authors, all male, who comprise a veritable ``Who's Who'' in creationism. For example, Henry Morris and John Whitcomb, the authors of the seminal young Earth creationist text, The Genesis Flood [Whitcomb and Morris, 1961], each contribute a brief introduction. Each chapter of Grand Canyon: A Different View begins with an overview by Vail, followed by brief comments by several contributors that ``have been peer reviewed to ensure a consistent and Biblical perspective.'' This perspective is strict Biblical literalism.

Elders, Wilfred A.

291

Interview with the expert: William E. Collins, Ph.D. Interviewed by Vicki Glaser.  

PubMed

William Collins, Ph.D., received his B.S. and M.Sc. degrees in entomology from Michigan State University. He completed his Ph.D. at Rutgers University in two years, just before being inducted into the Army to serve in the Korean War. He was assigned to Fort Detrick at the Biological Warfare Research Laboratories and after three years returned to Rutgers as an extension entomologist. He accepted a position in 1959 with the U.S. Public Health Service, with which he has worked for the last 50 years. In 1963, the Public Health Service laboratory moved to Atlanta and Dr. Collins' group began working with non-human primates following the discovery that monkey malarias were transmissible to humans. Parasites from monkeys or apes isolated in Asia, South America, and Africa were sent to the laboratory in Chamblee, Georgia, where they were adapted and transmitted to laboratory-maintained primates and their life cycles described and characterized. Transmissions to human volunteers were also attempted. In 1973, the laboratory operation was transferred to the CDC, and the emphasis changed from the study of monkey malaria in monkeys to that of human malaria in monkeys. During the last 25 to 30 years, different isolates of human malaria parasites have been adapted to New World monkeys to characterize the isolates for the development and testing of drugs and vaccines. Dr. Collins' task has been to identify and choose the best combination of vector-parasite-host combinations for testing each vaccine candidate. He has co-authored more than 450 manuscripts and has been awarded the U.S. Public Health Service Superior Service Award, The Joseph A. LaPrince Medal for Malariology from the American Society of Tropical Medicine and Hygiene, The Distinguished Service Award of the Department of Health and Human Services, the William Watson Medal of Excellence from the Centers for Disease Control and Prevention, and the Hoogstraal Medal from the American Committee of Medical Entomology. PMID:19835479

Collins, William E

2009-10-01

292

Integration of DNA barcoding into an ongoing inventory of complex tropical biodiversity.  

PubMed

Inventory of the caterpillars, their food plants and parasitoids began in 1978 for today's Area de Conservacion Guanacaste (ACG), in northwestern Costa Rica. This complex mosaic of 120 000 ha of conserved and regenerating dry, cloud and rain forest over 0-2000 m elevation contains at least 10 000 species of non-leaf-mining caterpillars used by more than 5000 species of parasitoids. Several hundred thousand specimens of ACG-reared adult Lepidoptera and parasitoids have been intensively and extensively studied morphologically by many taxonomists, including most of the co-authors. DNA barcoding - the use of a standardized short mitochondrial DNA sequence to identify specimens and flush out undisclosed species - was added to the taxonomic identification process in 2003. Barcoding has been found to be extremely accurate during the identification of about 100 000 specimens of about 3500 morphologically defined species of adult moths, butterflies, tachinid flies, and parasitoid wasps. Less than 1% of the species have such similar barcodes that a molecularly based taxonomic identification is impossible. No specimen with a full barcode was misidentified when its barcode was compared with the barcode library. Also as expected from early trials, barcoding a series from all morphologically defined species, and correlating the morphological, ecological and barcode traits, has revealed many hundreds of overlooked presumptive species. Many but not all of these cryptic species can now be distinguished by subtle morphological and/or ecological traits previously ascribed to 'variation' or thought to be insignificant for species-level recognition. Adding DNA barcoding to the inventory has substantially improved the quality and depth of the inventory, and greatly multiplied the number of situations requiring further taxonomic work for resolution. PMID:21564960

Janzen, Daniel H; Hallwachs, Winnie; Blandin, Patrick; Burns, John M; Cadiou, Jean-Marie; Chacon, Isidro; Dapkey, Tanya; Deans, Andrew R; Epstein, Marc E; Espinoza, Bernardo; Franclemont, John G; Haber, William A; Hajibabaei, Mehrdad; Hall, Jason P W; Hebert, Paul D N; Gauld, Ian D; Harvey, Donald J; Hausmann, Axel; Kitching, Ian J; Lafontaine, Don; Landry, Jean-François; Lemaire, Claude; Miller, Jacqueline Y; Miller, James S; Miller, Lee; Miller, Scott E; Montero, Jose; Munroe, Eugene; Green, Suzanne Rab; Ratnasingham, Sujeevan; Rawlins, John E; Robbins, Robert K; Rodriguez, Josephine J; Rougerie, Rodolphe; Sharkey, Michael J; Smith, M Alex; Solis, M Alma; Sullivan, J Bolling; Thiaucourt, Paul; Wahl, David B; Weller, Susan J; Whitfield, James B; Willmott, Keith R; Wood, D Monty; Woodley, Norman E; Wilson, John J

2009-05-01

293

Self-Selected or Mandated, Open Access Increases Citation Impact for Higher Quality Research  

PubMed Central

Background Articles whose authors have supplemented subscription-based access to the publisher's version by self-archiving their own final draft to make it accessible free for all on the web (“Open Access”, OA) are cited significantly more than articles in the same journal and year that have not been made OA. Some have suggested that this “OA Advantage” may not be causal but just a self-selection bias, because authors preferentially make higher-quality articles OA. To test this we compared self-selective self-archiving with mandatory self-archiving for a sample of 27,197 articles published 2002–2006 in 1,984 journals. Methdology/Principal Findings The OA Advantage proved just as high for both. Logistic regression analysis showed that the advantage is independent of other correlates of citations (article age; journal impact factor; number of co-authors, references or pages; field; article type; or country) and highest for the most highly cited articles. The OA Advantage is real, independent and causal, but skewed. Its size is indeed correlated with quality, just as citations themselves are (the top 20% of articles receive about 80% of all citations). Conclusions/Significance The OA advantage is greater for the more citable articles, not because of a quality bias from authors self-selecting what to make OA, but because of a quality advantage, from users self-selecting what to use and cite, freed by OA from the constraints of selective accessibility to subscribers only. It is hoped that these findings will help motivate the adoption of OA self-archiving mandates by universities, research institutions and research funders.

Gargouri, Yassine; Hajjem, Chawki; Lariviere, Vincent; Gingras, Yves; Carr, Les; Brody, Tim; Harnad, Stevan

2010-01-01

294

Nucleoside diphosphate kinase (NDPK, NM23, AWD): recent regulatory advances in endocytosis, metastasis, psoriasis, insulin release, fetal erythroid lineage and heart failure; translational medicine exemplified.  

PubMed

The guest editor (AM) provides his perspective on the most recent advances on nucleoside diphosphate kinase (NDPK, otherwise known as AWD or NM23) showcasing phospho-histidine biochemistry and its impact on diverse pathology when disordered. His co-author (SO) provides state-of-the-art analyses from the European institute of Bioinformatics in an appendix to support the most recent advances made by the NDPK community. Unfortunately, to those outside the field, NDPK is often dismissed as a tiny 'ancient housekeeper' protein found in marine sponges, social amoebae, worms, fruit flies, rodents and humans but the state-of-the-art papers overviewed here show that NDPK does not act simply in mindless rote, inter-converting cellular 'energy currencies'. That two NDPK isoforms regulate fetal erythroid lineage is a developmental case in point. Seminal Cancer Research UK support is gratefully acknowledged that generated additional resources to enable the NDPK community to meet in Dundee in 2007 ( www.dundee.ac.uk/mchs/ndpk ; next meeting is planned: 2010/Mannheim-Heidelberg). The presented papers illustrate the point that when scientists are left alone 'shut up in the narrow cell of their laboratory' (as the philosopher Ortega once said, a sentiment echoed by Erwin Schrödinger), then progress will ultimately occur bridging the gap between specialization and translation for human benefit. To aid translation, this overview initially introduces the NDPK family to the non-specialist, who serendipitously finds these proteins in their biology. This is immediately followed by examples of the diverse biology generated by this self-aggregating group of multi-functional proteins and finally capped by an emerging idea explaining how this diversity might arise. PMID:19415463

Mehta, Anil; Orchard, Sandra

2009-05-05

295

University of Rochester, Laboratory for Laser Energetics: Annual report, 1 October 1985-30 September 1986  

SciTech Connect

In FY86 the Laboratory has produced a list of accomplishments in which it takes pride. LLE has met every laser-fusion program milestone to date in a program of research for direct-drive ultraviolet laser fusion originally formulated in 1981. LLE scientists authored or co-authored 135 scientific papers during 1985-86. The collaborative experiments with NRL, LANL, and LLNL have led to a number of important ICF results. The cryogenic target system developed by KMS Fusion for LLE will be used in future high-density experiments on OMEGA to demonstrate the compression of thermonuclear fuel to 100 to 200 times that of solid (20 to 40 g/cm/sup 3/) in a test of the direct-drive concept, as noted in the National Academy of Sciences' report. The excellence of the advanced technology efforts at LLE is illustrated by the establishment of the Ultrafast Science Center by the Department of Defense through the Air Force Office of Scientific Research. Research in the Center will concentrate on bridging the gap between high-speed electronics and ultrafast optics by providing education, research, and development in areas critical to future communications and high-speed computer systems. The Laboratory for Laser Energetics continues its pioneering work on the interaction of intense radiation with matter. This includes inertial-fusion and advanced optical and optical electronics research; training people in the technology and applications of high-power, short-pulse lasers; and interacting with the scientific community, business, industry, and government to promote the growth of laser technology.

Not Available

1987-01-01

296

Cost of treating diabetic foot ulcers in five different countries.  

PubMed

Most estimates in the literature for the economic cost of treating a diabetic foot ulcer (DFU) are from industrialized countries. There is also marked heterogeneity between the complexity of cases considered in the different studies. The goal of the present article was to estimate treatment costs and costs to patients in five different countries (Chile, China, India, Tanzania, and the United States) for two hypothetical, but well-defined, DFUs at the extreme ends of the complexity spectrum. A co-author, who is a treating physician in the relevant country, was asked to choose treatment plans that represented the typical application of local resources to the DFU. The outcomes were pre-defined as complete healing in case 1 and trans-tibial amputation in case 2, but the time course of treatment was determined by each investigator in a manner that would be typical for their clinic. The costs, in local currencies, for each course of treatment were estimated with the assistance of local hospital administrators. Typical reimbursement scenarios in each country were used to estimate the cost burden to the patient, which was then expressed as a percentage of the annual per capita purchasing power parity-adjusted gross domestic product. There were marked differences in the treatment plans between countries based on the availability of resources and the realities of local conditions. The costs of treatment for case 1 ranged from Int$102 to Int$3959 in Tanzania and in the United States, respectively. The cost for case 2 ranged from Int$3060 to Int$188,645 in Tanzania and in the United States, respectively. The cost burden to the patient varied from the equivalent of 6 days of average income in the United States for case 1 to 5.7 years of average annual income for case 2 in India. Although these findings do not take cost-effectiveness into account, they highlight the dramatic economic burden of a DFU for patients in some countries. PMID:22271734

Cavanagh, Peter; Attinger, Christopher; Abbas, Zulfiqarali; Bal, Arun; Rojas, Nina; Xu, Zhang-Rong

2012-02-01

297

Evidence of a suffocation alarm system within the periaqueductal gray matter of the rat.  

PubMed

Dyspnea, hunger for air, and urge to flee are the cardinal symptoms of panic attacks. Patients also show baseline respiratory abnormalities and a higher rate of comorbid and antecedent respiratory diseases. Panic attacks are also precipitated by infusion of sodium lactate and inhalation of 5% CO? in predisposed patients but not in healthy volunteers or patients without panic disorder. Accordingly, Klein [Klein (1993) Arch Gen Psychiatry 50:306-317] suggested that clinical panic is the misfiring of an as-yet-unidentified suffocation alarm system. In rats, selective anoxia of chemoreceptor cells by potassium cyanide (KCN) and electrical and chemical stimulations of periaqueductal gray matter (PAG) produce defensive behaviors, which resemble panic attacks. Thus, here we examined the effects of single or combined administrations of CO? (8% and 13%) and KCN (10-80 ?g, i.v.) on spontaneous and PAG-evoked behaviors of rats either intact or bearing electrolytic lesions of PAG. Exposure to CO? alone reduced grooming while increased exophthalmus, suggesting an arousal response to non-visual cues of environment. Unexpectedly, however, CO? attenuated PAG-evoked immobility, trotting, and galloping while facilitated defecation and micturition. Conversely, KCN produced all defensive behaviors of the rat and facilitated PAG-evoked trotting, galloping, and defecation. There were also facilitatory trends in PAG-evoked exophthalmus, immobility, and jumping. Moreover, whereas the KCN-evoked defensive behaviors were attenuated or even suppressed by discrete lesions of PAG, they were markedly facilitated by CO?. Authors suggest that the PAG harbors an anoxia-sensitive suffocation alarm system which activation precipitates panic attacks and potentiates the subject responses to hypercapnia. PMID:22062132

Schimitel, F G; de Almeida, G M; Pitol, D N; Armini, R S; Tufik, S; Schenberg, L C

2011-10-25

298

How Much Mass Makes a Black Hole? - Astronomers Challenge Current Theories  

NASA Astrophysics Data System (ADS)

Using ESO's Very Large Telescope, European astronomers have for the first time demonstrated that a magnetar - an unusual type of neutron star - was formed from a star with at least 40 times as much mass as the Sun. The result presents great challenges to current theories of how stars evolve, as a star as massive as this was expected to become a black hole, not a magnetar. This now raises a fundamental question: just how massive does a star really have to be to become a black hole? To reach their conclusions, the astronomers looked in detail at the extraordinary star cluster Westerlund 1 [1], located 16 000 light-years away in the southern constellation of Ara (the Altar). From previous studies (eso0510), the astronomers knew that Westerlund 1 was the closest super star cluster known, containing hundreds of very massive stars, some shining with a brilliance of almost one million suns and some two thousand times the diameter of the Sun (as large as the orbit of Saturn). "If the Sun were located at the heart of this remarkable cluster, our night sky would be full of hundreds of stars as bright as the full Moon," says Ben Ritchie, lead author of the paper reporting these results. Westerlund 1 is a fantastic stellar zoo, with a diverse and exotic population of stars. The stars in the cluster share one thing: they all have the same age, estimated at between 3.5 and 5 million years, as the cluster was formed in a single star-formation event. A magnetar (eso0831) is a type of neutron star with an incredibly strong magnetic field - a million billion times stronger than that of the Earth, which is formed when certain stars undergo supernova explosions. The Westerlund 1 cluster hosts one of the few magnetars known in the Milky Way. Thanks to its home in the cluster, the astronomers were able to make the remarkable deduction that this magnetar must have formed from a star at least 40 times as massive as the Sun. As all the stars in Westerlund 1 have the same age, the star that exploded and left a magnetar remnant must have had a shorter life than the surviving stars in the cluster. "Because the lifespan of a star is directly linked to its mass - the heavier a star, the shorter its life - if we can measure the mass of any one surviving star, we know for sure that the shorter-lived star that became the magnetar must have been even more massive," says co-author and team leader Simon Clark. "This is of great significance since there is no accepted theory for how such extremely magnetic objects are formed." The astronomers therefore studied the stars that belong to the eclipsing double system W13 in Westerlund 1 using the fact that, in such a system, masses can be directly determined from the motions of the stars. By comparison with these stars, they found that the star that became the magnetar must have been at least 40 times the mass of the Sun. This proves for the first time that magnetars can evolve from stars so massive we would normally expect them to form black holes. The previous assumption was that stars with initial masses between about 10 and 25 solar masses would form neutron stars and those above 25 solar masses would produce black holes. "These stars must get rid of more than nine tenths of their mass before exploding as a supernova, or they would otherwise have created a black hole instead," says co-author Ignacio Negueruela. "Such huge mass losses before the explosion present great challenges to current theories of stellar evolution." "This therefore raises the thorny question of just how massive a star has to be to collapse to form a black hole if stars over 40 times as heavy as our Sun cannot manage this feat," concludes co-author Norbert Langer. The formation mechanism preferred by the astronomers postulates that the star that became the magnetar - the progenitor - was born with a stellar companion. As both stars evolved they would begin to interact, with energy derived from their orbital motion expended in ejecting the requisite huge quantities of mass from t

2010-08-01

299

Chandra Finds Evidence for Stellar Cannibalism  

NASA Astrophysics Data System (ADS)

Evidence that a star has recently engulfed a companion star or a giant planet has been found using NASA's Chandra X-ray Observatory. The likely existence of such a "cannibal" star provides new insight into how stars and the planets around them may interact as they age. The star in question, known as BP Piscium (BP Psc), appears to be a more evolved version of our Sun, but with a dusty and gaseous disk surrounding it. A pair of jets several light years long blasting out of the system in opposite directions has also been seen in optical data. While the disk and jets are characteristics of a very young star, several clues -- including the new results from Chandra -- suggest that BP Psc is not what it originally appeared to be. Instead, astronomers have suggested that BP Psc is an old star in its so-called red giant phase. And, rather than being hallmarks of its youth, the disk and jets are, in fact, remnants of a recent and catastrophic interaction whereby a nearby star or giant planet was consumed by BP Psc. When stars like the Sun begin to run out of nuclear fuel, they expand and shed their outer layers. Our Sun, for example, is expected to swell so that it nearly reaches or possibly engulfs Earth, as it becomes a red giant star. "It appears that BP Psc represents a star-eat-star Universe, or maybe a star-eat-planet one," said Joel Kastner of the Rochester Institute of Technology, who led the Chandra study. "Either way, it just shows it's not always friendly out there." Several pieces of information have led astronomers to rethink how old BP Psc might be. First, BP Psc is not located near any star-forming cloud, and there are no other known young stars in its immediate vicinity. Secondly, in common with most elderly stars, its atmosphere contains only a small amount of lithium. Thirdly, its surface gravity appears to be too weak for a young star and instead matches up with one of an old red giant. Chandra adds to this story. Young, low-mass stars are brighter than most other stars in X-rays, and so X-ray observations can be used as a sign of how old a star may be. Chandra does detect X-rays from BP Psc, but at a rate that is too low to be from a young star. Instead, the X-ray emission rate measured for BP Psc is consistent with that of rapidly rotating giant stars. The spectrum of the X-ray emission -- that is how the amount of X-rays changes with wavelength -- is consistent with flares occurring on the surface of the star, or with interactions between the star and the disk surrounding it. The magnetic activity of the star itself might be generated by a dynamo caused by its rapid rotation. This rapid rotation can be caused by the engulfment process. "It seems that BP Psc has been energized by its meal," said co-author Rodolfo (Rudy) Montez Jr., also from the Rochester Institute of Technology. The star's surface is obscured throughout the visible and near-infrared bands, so the Chandra observation represents the first detection at any wavelength of BP Psc itself. "BP Psc shows us that stars like our Sun may live quietly for billions of years," said co-author David Rodriguez from UCLA, "but when they go, they just might take a star or planet or two with them." Although any close-in planets were presumably devastated when BP Psc turned into a giant star, a second round of planet formation might be occurring in the surrounding disk, hundreds of millions of years after the first round. A new paper using observations with the Spitzer Space Telescope has reported possible evidence for a giant planet in the disk surrounding BP Psc. This might be a newly formed planet or one that was part of the original planetary system. "Exactly how stars might engulf other stars or planets is a hot topic in astrophysics today," said Kastner. "We have many important details that we still need to work out, so objects like BP Psc are really exciting to find." These results appeared in The Astrophysical Journal Letters. Other co-authors on the study were Nicolas Grosso

2010-09-01

300

GOODS Missing Black Hole Report: Hundreds Found!  

NASA Astrophysics Data System (ADS)

Astronomers have unmasked hundreds of black holes hiding deep inside dusty galaxies billions of light-years away Normal Galaxies Normal Galaxies The massive, growing black holes, discovered by NASA's Spitzer and Chandra space telescopes, represent a large fraction of a long-sought missing population. Their discovery implies there are hundreds of millions of additional black holes growing in our young universe, more than doubling the total amount known at that distance. "Active, supermassive black holes are everywhere in the early universe," said Mark Dickinson of the National Optical Astronomy Observatory in Tucson, Ariz. "We had seen the tip of the iceberg before in our search for these objects. Now, we can see the iceberg itself." Dickinson is a co-author of two new papers appearing in the Nov. 10 issue of the Astrophysical Journal. Emanuele Daddi of the Commissariat a l'Energie Atomique in France led the research. The findings are also the first direct evidence that most, if not all, massive galaxies in the distant universe spend their youths building monstrous black holes at their cores. For decades, large populations of active black holes have been considered missing. These highly energetic structures, also called quasars, consist of a dusty, doughnut-shaped cloud that surrounds and feeds a growing supermassive black hole. They give off a lot of X-rays that can be detected as a general glow in space, but sometimes the quasars themselves can't be seen because dust and gas blocks their X-rays from our point of view. "We knew from other studies from about 30 years ago that there must be more quasars in the universe, but we didn't know where to find them until now," said Daddi. Daddi and his team initially set out to study 1,000 dusty, massive galaxies that are busy making stars, and were thought to lack quasars. The galaxies are about the same mass as our own spiral Milky Way galaxy, but irregular in shape. At 9 to 11 billion light-years away, they exist at a time when the universe was in its infancy, between 2.5 and 4.5 billion years old. When the astronomers peered more closely at the galaxies with Spitzer's infrared eyes, they noticed that about 200 of the galaxies gave off an unusual amount of infrared light. X-ray data from Chandra, and a technique called "stacking," revealed the galaxies were in fact hiding plump quasars inside. The scientists now think that the quasars heat the dust in their surrounding doughnut clouds, releasing the excess infrared light. "We found most of the population of hidden quasars in the early universe," said Daddi. Previously, only the rarest and most energetic of these hidden black holes had been seen at this early epoch. For decades, large populations of active black holes have been considered missing. These highly energetic structures, also called quasars, consist of a dusty, doughnut-shaped cloud that surrounds and feeds a growing supermassive black hole. They give off a lot of X-rays that can be detected as a general glow in space, but sometimes the quasars themselves can't be seen because dust and gas blocks their X-rays from our point of view. The newfound quasars are helping answer fundamental questions about how massive galaxies evolve. For instance, astronomers have learned that most massive galaxies steadily build up their stars and black holes simultaneously until they get too big and their black holes suppress star formation. The observations also suggest that collisions between galaxies might not play as large a role in galaxy evolution as previously believed. "Theorists thought that mergers between galaxies were required to initiate this quasar activity, but we now see that quasars can be active in unharrassed galaxies," said co-author David Alexander of Durham University, United Kingdom. "It's as if we were blind-folded studying the elephant before, and we weren't sure what kind of animal we had," added co-author David Elbaz of the Commissariat a l'Energie Atomique. "Now, we can see the elephant

2007-10-01

301

Orbiting observatory SOHO finds source of high-speed "wind" blowing from the Sun  

NASA Astrophysics Data System (ADS)

"The search for the source of the solar wind has been like the hunt for the source of the Nile," said Dr. Don Hassler of the Southwest Research Institute, Boulder, Colorado, lead author of the paper in Science. "For 30 years, scientists have observed high-speed solar wind coming from regions in the solar atmosphere with open magnetic field lines, called coronal holes. However, only recently, with the observations from SOHO, have we been able to measure the detailed structure of this source region". The solar wind comes in two varieties : high-speed and low-speed. The low-speed solar wind moves at "only" 1.5 million kilometres per hour, while the high-speed wind is even faster, moving at speeds as high as 3 million kilometres per hour. As it flows past Earth, the solar wind changes the shape and structure of the Earth's magnetic field. In the past, the solar wind didn't affect us directly, but as we become increasingly dependent on advanced technology, we become more susceptible to its effects. Researchers are learning that variations in the solar wind flow can cause dramatic changes in the shape of the Earth's magnetic field, which can damage satellites and disrupt communications and electrical power systems. The nature and origin of the solar wind is one of the main mysteries ESA's solar observatory SOHO was designed to solve. It has long been thought that the solar wind flows from coronal holes; what is new is the discovery that these outflows are concentrated in specific patches at the edges of the honeycomb-shaped magnetic fields. Just below the surface of the Sun there are large convection cells, and each cell has a magnetic field associated with it. "If one thinks of these cells as paving stones in a patio, then the solar wind is breaking through like grass around the edges, concentrated in the corners where the paving stones meet", said Dr. Helen Mason, University of Cambridge, England, and co-author of the paper to appear in Science. "However, at speeds ranging from 30,000 km/h at the surface to over 3 million km/h, the solar wind "grows" much faster than grass". "Looking at the spot where the solar wind actually appears is extremely important", says co-author Dr. Philippe Lemaire of the Institut d'Astrophysique Spatiale in Orsay, France. The Solar Ultraviolet Measurements of Emitted Radiation (SUMER) spectrometer on SOHO detected the solar wind by observing the ultraviolet spectrum over a large area of the solar north polar region. The SUMER instrument was built under the leadership of Dr. Klaus Wilhelm at the Max-Planck-Institut für Aeronomie in Lindau, Germany, with key contributions from the Institut d'Astrophysique Spatiale in Orsay, France, the NASA Goddard Space Flight Center in Greenbelt, Maryland, and the University of California at Berkeley, with financial support from German, French, US and Swiss national agencies. "Identification of the detailed structure of the source region of the fast solar wind is an important step in solving the solar wind acceleration problem. We can now focus our attention on the plasma conditions and the dynamic processes seen in the corners of the magnetic field structures", says Dr. Wilhelm, also co-author of the Science paper. A spectrum results from the separation of light into its component colours, which correspond to different wavelengths. Blue light has a shorter wavelength and is more energetic than red. A spectrum is similar to what is seen when a prism separates white light into a rainbow of distinct colours. By analysing light this way, astronomers learn a great deal about the object emitting the light, such as its temperature, chemical composition, and motion. The ultraviolet light observed by SUMER is actually invisible to the human eye and cannot penetrate the Earth's atmosphere. The hot gas in the solar wind source region emits light at certain ultraviolet wavelengths. When the hot gas flows towards Earth, as it does in the solar wind, the wavelengths of the ultraviolet light emitt

1999-02-01

302

Final Report for Phase I Northern California CO2 Reduction Project  

SciTech Connect

On June 8, 2009, the U. S. Department of Energy's National Energy Technology Laboratory released a Funding Opportunity Announcement (DE-FOA 0000015) with the title, Recovery Act: Carbon Capture and Sequestration from Industrial Sources and Innovative Concepts for Beneficial CO{sub 2} Use. C6 Resources (C6), an affiliate of Shell Oil Company, responded with a proposal for Technology Area 1: Large-scale industrial carbon capture and sequestration (CCS) projects from industrial sources. As DOE Federally Funded Research and Development Center (FFRDC) Contractors, Lawrence Livermore National Laboratory (LBNL) and Lawrence Berkeley National Laboratory (LLNL) proposed to collaborate with C6 and perform technical tasks, which C6 included in the C6 proposal, titled the Northern California CO{sub 2} Reduction Project. The proposal was accepted for Phase I funding and C6 received DOE Award DEFE0002042. LLNL and LBNL each received Phase I funding of $200,000, directly from DOE. The essential task of Phase I was to prepare a proposal for Phase II, which would be a five-year, detailed technical proposal, budget, and schedule for a complete carbon capture, transportation, and geologic storage project, with the objective of starting the injection of 1 million tons per year of industrial CO2 by the end of FY2015. LLNL and LBNL developed technical proposals (and DOE Field Work Proposals [FWPs]) for many aspects of the geologic testing and CO{sub 2} monitoring that were included in the C6 Phase II proposal, which C6 submitted by the deadline of April 16, 2010. This document is the Final Report for LLNL's Phase I efforts and is presented in two parts. Part 1 is the complete text of the technical proposal provided to C6 by LLNL and LBNL for inclusion in the C6 Phase II proposal. Because of space limitations, however, C6 may not have included all of this information in their proposal. In addition to developing the proposal presented below, LLNL's Bill Foxall and Laura Chiarmonte, in collaboration with LBNL, undertook preliminary technical work evaluating the potential for induced seismicity in Solano County. Part 2 presents technical work preformed during Phase I in the development of a preliminary Certification Framework: Leakage Risk Assessment for CO{sub 2} Injection at the Montezuma Hills Site, Solano County, California, co-authored by LLNL and LBNL collaborators.

Wagoner, J

2010-10-26

303

Geophysical and hydrogeologic investigations of two primary alluvial aquifers embedded in the southern San Andreas fault system: San Bernardino basin and upper Coachella Valley  

NASA Astrophysics Data System (ADS)

This study of alluvial aquifer basins in southern California is centered on observations of differential surface displacement and the search for the mechanisms of deformation. The San Bernardino basin and the Upper Coachella Valley aquifers are bound by range fronts and fault segments of the southern San Andreas fault system. I have worked to quantify long-term compaction in these groundwater dependent population centers with a unique synthesis of data and methodologies using Interferometric Synthetic Aperture Radar (InSAR) and groundwater data. My dissertation contributes to the understanding of alluvial aquifer heterogeneity and partitioning. I model hydrogeologic and tectonic interpretations of deformation where decades of overdraft conditions and ongoing aquifer development contribute to extreme rapid subsidence. I develop the Hydrogeologic InSAR Integration (HII) method for the characterization of surface deformation in aquifer basins. The method allows for the separation of superimposed hydraulic and/or tectonic processes in operation. This formalization of InSAR and groundwater level integration provides opportunities for application in other aquifer basins where overdraft conditions may be causing permanent loss of aquifer storage capacity through compaction. Sixteen years of SAR data for the Upper Coachella Valley exhibit rapid vertical surface displacement (? 48mm/a) in sharply bound areas of the western basin margin. Using well driller logs, I categorize a generalized facies analysis of the western basin margin, describing heterogeneity of the aquifer. This allowed for assessment of the relationships between observed surface deformation and sub-surface material properties. Providing the setting and context for the hydrogeologic evolution of California's primary aquifers, the mature San Andreas transform fault is studied extensively by a broad range of geoscientists. I present a compilation of observations of creep, line integrals across the Pacific-North America Plate Boundary, and strain tensor volumes for comparison to the Working Group 2007 (UCERF 2) seismicity-based deformation model. I find that the moment accumulation across the plate boundary is consistent with the deformation model, suggesting fault displacement observations within the plate boundary zone accurately capture the strain across the plate boundary. This dissertation includes co-authored materials previously published, and also includes unpublished work currently under revisions for submission to a technical journal.

Wisely, Beth Ann

304

Nonlinear surface plasmon polaritons: Analytical and numerical studies  

NASA Astrophysics Data System (ADS)

This dissertation contains analytical and numerical studies of nonlinear surface plasmon polaritons (SPPs). In our studies, we consider SPP propagation at the interface between a noble metal with a cubic optical nonlinearity and an optically linear dielectric. We first consider a sum frequency generation process during the nonlinear interaction, where a nonlinear polarization with tripled frequency is generated from the incident fundamental SPP. Using the non-depletion approximation, the solution of the nonlinear wave equation shows a third harmonic generation process from the incident SPP wave. The solution is bound in the dielectric while freely propagating in the metal. For realistic noble metals with absorption, we use silver for its transparency window around the plasma frequency. In this window, absorption losses are reduced and the resultant signal has a good transmittance within the metal. The energy conversion efficiency from the incident SPP wave to the THG signal is about 0.1% for excitation using a standard continuous wave laser with visible light intensity I = 103W/cm2. Once generated, the propagation angle of the signal is fully determined by the optical properties of the dielectric and the metal layers. We next consider a nonlinear polarization with the same frequency as the incident light. In this process the third order nonlinearity of the metal is described by a nonlinear optical refractive index. After applying the slowly varying amplitude approximation, the nonlinear wave equation takes the form of a nonlinear temporal Schrodinger (NLS) equation. The solution to the NLS equation for the nonlinear SPP is a temporal dark soliton. In addition to analytical studies, computational methods are also used. With no metal loss, the numerical solution shows stable propagation of a temporal dark soliton, when the initial pulse has a tanh envelope satisfying the threshold peak amplitude. For an arbitrary input pulse, instabilities such as background oscillations and multi-peak breakups occur. With metal loss, the initial input optical pulse decays while maintaining a single pulse shape when the initial amplitude satisfies the same tanh envelope condition as in the lossless case. For an arbitrary initial, background oscillations or pulse breakups occur after a short time of propagation. This dissertation includes previously published and unpublished co-authored material.

Guo, Yan

305

Inertial Confinement Fusion Annual Report 1997  

SciTech Connect

The ICF Annual Report provides documentation of the achievements of the LLNL ICF Program during the fiscal year by the use of two formats: (1) an Overview that is a narrative summary of important results for the fiscal year and (2) a compilation of the articles that previously appeared in the ICF Quarterly Report that year. Both the Overview and Quarterly Report are also on the Web at http://lasers.llnl.gov/lasers/pubs/icfq.html. Beginning in Fiscal Year 1997, the fourth quarter issue of the ICF Quarterly was no longer printed as a separate document but rather included in the ICF Annual. This change provided a more efficient process of documenting our accomplishments with-out unnecessary duplication of printing. In addition we introduced a new document, the ICF Program Monthly Highlights. Starting with the September 1997 issue and each month following, the Monthly Highlights will provide a brief description of noteworthy activities of interest to our DOE sponsors and our stakeholders. The underlying theme for LLNL's ICF Program research continues to be defined within DOE's Defense Programs missions and goals. In support of these missions and goals, the ICF Program advances research and technology development in major interrelated areas that include fusion target theory and design, target fabrication, target experiments, and laser and optical science and technology. While in pursuit of its goal of demonstrating thermonuclear fusion ignition and energy gain in the laboratory, the ICF Program provides research and development opportunities in fundamental high-energy-density physics and supports the necessary research base for the possible long-term application of inertial fusion energy for civilian power production. ICF technologies continue to have spin-off applications for additional government and industrial use. In addition to these topics, the ICF Annual Report covers non-ICF funded, but related, laser research and development and associated applications. We also provide a short summary of the quarterly activities within Nova laser operations, Beamlet laser operations, and National Ignition Facility laser design. LLNL's ICF Program falls within DOE's national ICF program, which includes the Nova and Beamlet (LLNL), OMEGA (University of Rochester Laboratory for Laser Energetics), Nike (Naval Research Laboratory), and Trident (Los Alamos National Laboratory) laser facilities. The Particle Beam Fusion Accelerator (Z) and Saturn pulsed-power facilities are at Sandia National Laboratories. General Atomics, Inc., develops and provides many of the targets for the above experimental facilities. Many of the ICF Annual Report articles are co-authored with our colleagues from these other ICF institutions.

Correll, D

1998-06-01

306

Comparative biomass structure and estimated carbon flow in food webs in the deep Gulf of Mexico  

NASA Astrophysics Data System (ADS)

A budget of the standing stocks and cycling of organic carbon associated with the sea floor has been generated for seven sites across a 3-km depth gradient in the NE Gulf of Mexico, based on a series of reports by co-authors on specific biotic groups or processes. The standing stocks measured at each site were bacteria, Foraminifera, metazoan meiofauna, macrofauna, invertebrate megafauna, and demersal fishes. Sediment community oxygen consumption (SCOC) by the sediment-dwelling organisms was measured at each site using a remotely deployed benthic lander, profiles of oxygen concentration in the sediment pore water of recovered cores and ship-board core incubations. The long-term incorporation and burial of organic carbon into the sediments has been estimated using profiles of a combination of stable and radiocarbon isotopes. The total stock estimates, carbon burial, and the SCOC allowed estimates of living and detrital carbon residence time within the sediments, illustrating that the total biota turns over on time scales of months on the upper continental slope but this is extended to years on the abyssal plain at 3.6 km depth. The detrital carbon turnover is many times longer, however, over the same depths. A composite carbon budget illustrates that total carbon biomass and associated fluxes declined precipitously with increasing depth. Imbalances in the carbon budgets suggest that organic detritus is exported from the upper continental slope to greater depths offshore. The respiration of each individual "size" or functional group within the community has been estimated from allometric models, supplemented by direct measurements in the laboratory. The respiration and standing stocks were incorporated into budgets of carbon flow through and between the different size groups in hypothetical food webs. The decline in stocks and respiration with depth were more abrupt in the larger forms (fishes and megafauna), resulting in an increase in the relative predominance of smaller sizes (bacteria and meiofauna) at depth. Rates and stocks in the deep northern GoM appeared to be comparable to other continental margins where similar comparisons have been made.

Rowe, Gilbert T.; Wei, Chihlin; Nunnally, Clifton; Haedrich, Richard; Montagna, Paul; Baguley, Jeffrey G.; Bernhard, Joan M.; Wicksten, Mary; Ammons, Archie; Briones, Elva Escobar; Soliman, Yousra; Deming, Jody W.

2008-12-01

307

Surface science experiments involving the atomic force microscope  

NASA Astrophysics Data System (ADS)

Three diverse first author surfaces science experiments conducted by Sean P. McBride1-3 will be discussed in detail and supplemented by secondary co-author projects by Sean P. McBride,4-7 all of which rely heavily on the use of an atomic force microscope (AFM). First, the slip length parameter, b of liquids is investigated using colloidal probe AFM. The slip length describes how easily a fluid flows over an interface. The slip length, with its exact origin unknown and dependencies not overwhelming decided upon by the scientific community, remains a controversial topic. Colloidal probe AFM uses a spherical probe attached to a standard AFM imaging tip driven through a liquid. With the force on this colloidal AFM probe known, and using the simplest homologous series of test liquids, many of the suspected causes and dependencies of the slip length demonstrated in the literature can be suppressed or eliminated. This leaves the measurable trends in the slip length attributed only to the systematically varying physical properties of the different liquids. When conducting these experiments, it was realized that the spring constant, k, of the system depends upon the cantilever geometry of the experiment and therefore should be measured in-situ. This means that the k calibration needs to be performed in the same viscous liquid in which the slip experiments are performed. Current in-situ calibrations in viscous fluids are very limited, thus a new in-situ k calibration method was developed for use in viscous fluids. This new method is based upon the residuals, namely, the difference between experimental force-distance data and Vinogradova slip theory. Next, the AFM's ability to acquire accurate sub nanometer height profiles of structures on interfaces was used to develop a novel experimental technique to measure the line tension parameter, tau, of isolated nanoparticles at the three phase interface in a solid-liquid-vapor system. The tau parameter is a result of excess energy caused by the imbalance of the complex intermolecular forces experienced at the three phase contact line. Many differences in the sign and magnitude of the tau parameter exist in the current literature, resulting in tau being a controversial topic.

McBride, Sean P.

308

Recent Neutron Studies of the Iron-based Magnetic Superconductors  

NASA Astrophysics Data System (ADS)

We present results of recent neutron scattering investigations at the NCNR of the crystal structures, magnetic structures, and spin dynamics of the iron-based ROFe(As,P) (R=La, Ce, Pr, Nd), (Ba,Sr,Ca)Fe2As2, and Fe1-x(Se-Te) superconductors [1]. All the undoped materials exhibit universal behavior, where a tetragonal-to-orthorhombic structural transition occurs between ˜140-220 K, at or below which the systems order antiferromagnetically. The magnetic structure within the a-b plane consists of chains of parallel Fe spins that are coupled antiferromagnetically in the orthogonal direction, with an ordered moment typically less than 1 ?B. Hence these are itinerant electron magnets, with a spin structure that is consistent with Fermi-surface nesting. The exchange interactions are strong, with spin-wave bandwidths ˜200 meV. The rare-earth moments order antiferromagnetically at low T like ``conventional'' magnetic-superconductors, while the crystal field excitations can be employed to study the properties of the superconducting state. With doping in CeFeAsO1-xFx, LaFeAsO1-xFx, and SrFe2-yNiyAs2 [2] the structural and magnetic transitions are suppressed in favor of superconductivity. The application of pressure in CaFe2As2 transforms the system from a magnetically ordered orthorhombic material to a ``collapsed'' non-magnetic tetragonal system. In the superconducting doping regime, well defined spin correlations and a clear magnetic resonance in the magnetic excitation spectrum that tracks the superconducting order parameter are observed, reminiscent of the cuprate superconductors [3]. The overall results clearly indicate that the magnetic properties are a key element in these iron-based superconductors. Further information and references can be found at http://www.ncnr.nist.gov/staff/jeff [4pt] [1] For a recent neutron review see J. W. Lynn and P. Dai, Physica C 469, 469 (2009). [0pt] [2] N. Kumar, et al., Phys. Rev. B 80, 144524 (2009). [0pt] [3] S. Li, et al., Phys. Rev. B 79, 174527 (2009). [4pt] It is a pleasure to acknowledge my collaborators at the NCNR and the many collaborators with the following groups: P. Dai (U. Tennessee/ORNL), N. L. Wang (Beijing), R. J. Cava (Princeton U.), A. Goldman (Ames Lab), W. Bao (LANL), S. Dhar (TIFR), J. P. Paglione (U. Maryland). Please see [1] for a complete list of co-authors.

Lynn, Jeffrey

2010-03-01

309

The Tropical Tropopause Layer: ERA-40 versus ERA-Interim reanalyses  

NASA Astrophysics Data System (ADS)

The Tropical Tropopause Layer (TTL) is currently a region of interest in climate studies, not only because it represents the interface between two different dynamical regimes, but also because it is the "gate" from the troposphere to the stratosphere for many atmospheric tracers. Although great progress has been recently made in understanding the TTL, there are still some aspects that need to be studied. It is well known that reanalyses are powerful tools widely used in climate studies, and many efforts are made to reach a realistic representation of the atmospheric circulation. In the framework of the SPARC Project, an intercomparison of middle-atmosphere climatologies identified ERA-40 as the dataset that better reproduced tropical processes in the stratosphere among other ten climatologies (Randel et al., 2004). Many key aspects affecting the stratospheric circulation were improved in the latest ECMWF reanalysis, i.e. ERA-Interim, respect to ERA-40. In the present work we analyze how the TTL is represented in both reanalyses. Our analysis of the TTL shows that ERA-Interim reproduces better the properties of this peculiar region: several deficiencies observed in ERA-40 have been eliminated in the new reanalyisis. Recent studies showed that the stratospheric residual circulation, excessive in ERA-40, was much improved in ERA-Interim. In agreement with this result, we have identified too intense upwelling in the TTL region using ERA-40 data. This enhanced upward mass flux in ERA-40 changes the static stability and thus the vertical structure of the TTL, extending the tropopause-like properties to upper levels. The unreal tropical upwelling in ERA-40 also affects tracer concentration in the stratosphere outside the tropical regions. In particular, we have found relevant differences between both databases when analyzing the distribution and transport of water vapor and ozone. In order to understand the origin of the differences in tropical upwelling between both ECMWF reanalyses, we have evaluated the wave activity. We have seen relevant discrepancies in the Eliassen-Palm flux divergence, both in the extratropical and the subtropical region. Our results suggest that the improved wave activity observed in ERA-Interim contributes to reach a more realistic representation of the tropical upwelling. In turn, this better representation of the TTL in ERA-Interim could be of great help in solving the current controversy on what processes are driving tropical upwelling. Randel, W. J. and 17 co-authors (2004): "The SPARC Intercomparison of Middle-Atmosphere Climatologies", J. Climate, 17, 986-1003.

Abalos, Marta; Serrano, Encarna

2010-05-01

310

Nonlinear wave packet interferometry and molecular state reconstruction  

NASA Astrophysics Data System (ADS)

Nonlinear wave packet interferometry (WPI) uses two phase-locked pulse-pairs to excite a molecular electronic population and measures those contributions arising from a one-pulse nuclear wave packet overlapping with a three-pulse nuclear wave packet. The interferogram quantifies the wave-packet interference at the probability-amplitude level and, with knowledge of the three-pulse (reference) wave packets, enables reconstruction of the one-pulse (target) wave packet. In one-color nonlinear WPI, both pulse-pairs resonate with the same electronic transition and the interferogram measures a sum of wave-packet overlaps. Experimental conditions often minimize mixing of these overlaps and hence permit molecular state reconstruction, as demonstrated by numerical calculations for model harmonic and photodissociative systems. Yet, a one-color reconstruction technique requires information about the Hamiltonian under which the target and reference states propagate. The latter knowledge obviates the practical need for experimental state determination, since computational methods are then a viable, alternative solution. Two-color nonlinear WPI, in which the pulse-pairs drive different electronic transitions, circumvents the need for information about the target-state Hamiltonian by using an auxiliary electronic level for preparing the reference states. Furthermore, in a two-color experiment, the interferogram measures a single wave-packet overlap, definitely identifying the information necessary for molecular state reconstruction. These features suggest two-color nonlinear WPI could serve as a diagnostic tool for identifying optically-controlled, yet unknown, molecular dynamics. Simulations for model systems and the lithium dimer demonstrate that target states can be reconstructed in the presence of signal noise, thermal mixtures, and rovibrational coupling and in the absence of information about the target-state Hamiltonian. In the presence of electronic-energy transfer, the interferogram reveals changes in the probability amplitude first-order in the inter-chromophore scalar coupling J. Controlling the polarization of the pulse-pairs enables selective excitation of the components in a model dimer complex and isolation of the overlap between a three-pulse reference wave packet, independent of J, and a one-pulse target wave packet, whose electronic and nuclear degrees of freedom are entangled. The processes underlying coherent energy transfer are identified by interpreting the interferogram with the help of quasi-classical phase-space diagrams. This dissertation includes both my previously published and my co-authored materials.

Humble, Travis Selby

311

Water: Where, What, Why, How?  

NSDL National Science Digital Library

Students in groups of 2-3 are charged with making posters that explain the role of water in key processes within selected Earth environments. Each group will be given a poster board. Student groups will chose from a list of possible environments: 1) upper mantle; 2) role of water in the asthenosphere; 3) hydrothermal systems at spreading centers; 4) water in subducting slabs to ~100 km; 5) arc magma generation; 6) water in subducting deep slabs; 7) water in the lower mantle (reactions with metallic iron to form hydrous phases); 8) water in the mantle transition zone; 9) continental basins; 10) upper crust/ground water; 11) mid-continental crust; 12) water in fault zones; 13) interaction of climate and tectonics; 14) origin of Earth's water. [By the end of the semester I should know student well enough that I can help guide students toward topics of appropriate interest/difficulty as necessary]. Posters will include: a) a concise statement of: the environment, and the key process(es) in which water plays a role (I prefer that the students stick to one major process if possible); b) concept maps/logic diagrams as a means to organize the key questions, processes, information, 'knowns', and unknowns; c) figures/illustrations to elucidate key concepts; d) concise text to guide the reader through the poster; e) unanswered questions/concerns; f) one or two key references; g) a complete list of references. Posters will be displayed on a public location in on campus. (We have a wonderful extra-wide hallway/alcove the Department of Geological Sciences that serves this purpose). Each student will view each of the class posters and submit a written evaluation of each poster. Evaluation will follow specific items including content, clarity, value of visuals, and creativity. To focus students' evaluation we will have an evaluation form that is consistent throughout the semester, used for all poster project activities. (past experience tells me the form will evolve). Evaluations will be signed, and all evaluations will be shared with the co-authors of the appropriate poster. As a class we will have a guided group discussion of the individual environments and the connections between environments. Poster authors will help guide discussion/answer questions during the discussion of their environment. The discussion will take place instead of a final exam, but during the scheduled exam time (2 hours). Beginning reference materials: I am in the process of gathering appropriate reference material to get students started. A preliminary list follows:

Hansen, Vicki

312

Rtop - an R package for interpolation along the stream network  

NASA Astrophysics Data System (ADS)

Geostatistical methods have a long tradition within analysis of data that can be conceptualized as simple point data, such as soil properties, or for regular blocks, such as mining data. However, these methods have been used to a limited extent for estimation along stream networks. A few exceptions are given by (Gottschalk 1993, Sauquet et al. 2000, Gottschalk et al. 2006, Skøien et al. 2006), and an overview by Laaha and Blöschl (2011). Interpolation of runoff characteristics are more complicated than the traditional random variables estimated by geostatistical methods, as the measurements have a more complicated support, and many catchments are nested. Skøien et al. (2006) presented the model Top-kriging which takes these effects into account for interpolation of stream flow characteristics (exemplified by the 100 year flood). The method has here been implemented as a package in the open source statistical environment R (R Development Core Team 2011). Taking advantage of the existing methods in R for working with spatial objects, and the extensive possibilities for visualizing the result, this makes it considerably easier to apply the method on new data sets, in comparison to earlier implementation of the method. In addition to user feedback, the package has also been tested by colleagues whose only responsibility has been to search for bugs, inconsistencies and shortcomings of the documentation. The last part is often the part that gets the least attention in small open source projects, and we have solved this by acknowledging their effects as co-authors. The model will soon be uploaded to CRAN, but is in the meantime also available from R-forge and can be installed by: > install.packages("rtop", repos="http://R-Forge.R-project.org") Gottschalk, L., 1993. Interpolation of runoff applying objective methods. Stochastic Hydrology and Hydraulics, 7, 269-281. Gottschalk, L., Krasovskaia, I., Leblois, E. & Sauquet, E., 2006. Mapping mean and variance of runoff in a river basin. Hydrology and Earth System Sciences, 10, 469-484. Laaha, G. & Blöschl, G. 2011. Geostatistics on river networks - a reviewed. EGU General Assembly, Vienna, Austria. R Development Core Team, 2011. R: A language and environment for statistical computing. Vienna, Austria, ISBN 3-900051-07-0. Sauquet, E., Gottschalk, L. & Leblois, E., 2000. Mapping average annual runoff: A hierarchical approach applying a stochastic interpolation scheme. Hydrological Sciences Journal, 45 (6), 799-815. Skøien, J.O., Merz, R. & Blöschl, G., 2006. Top-kriging - geostatistics on stream networks. Hydrology and Earth System Sciences, 10, 277-287.

Skøien, J. O.; Laaha, G.; Koffler, D.; Blöschl, G.; Pebesma, E.; Parajka, J.; Viglione, A.

2012-04-01

313

EDITORIAL: The interaction of radio-frequency fields with fusion plasmas: the JET experience The interaction of radio-frequency fields with fusion plasmas: the JET experience  

NASA Astrophysics Data System (ADS)

The JET Task Force Heating is proud to present this special issue. It is the result of hard and dedicated work by everybody participating in the Task Force over the last four years and gives an overview of the experimental and theoretical results obtained in the period 2008-2010 with radio frequency heating of JET fusion plasmas. Topics studied and reported in this issue are: investigations into the operation of lower hybrid heating accompanied by new modeling results; new experimental results and insights into the physics of various ion cyclotron range of frequencies (ICRF) heating scenarios; progress in studies of intrinsic and ion cyclotron wave-induced plasma rotation and flows; a summary of the developments over the last years in designing an ion cyclotron radiofrequency heating (ICRH) system that can cope with the presence of fast load variations in the edge, as e.g. caused by pellets or edge localized modes (ELMs) during H-Mode operation; an overview of the results obtained with the ITER-like antenna operating in H-Mode with a packed array of straps and power densities close to those of the projected ITER ICRH antenna; and, finally, a summary of the results obtained in applying ion cyclotron waves for wall conditioning of the tokamak. This issue would not have been possible without the strong motivation and efforts (sometimes truly heroic) of all colleagues of the JET Task Force Heating. A sincere word of thanks, therefore, to all authors and co-authors involved in the experiments, analysis and compilation of the papers. It was a special privilege to work with all of them during the past very intense years. Thanks also to all other European and non-European scientists who contributed to the JET scientific programme, the operations team of JET and the colleagues of the Close Support Unit in Culham. Thanks also to the editors, Editorial Board and referees of Plasma Physics and Controlled Fusion, together with the publishing staff of IOPP, who have not only supported but also contributed very substantially to this initiative. Without their dedication this issue would not have been possible in its present form. A special word of thanks to Marie-Line Mayoral and Joelle Mailloux for their precious help and very active support in running the JET Task Force Heating over the last years. Without Joelle and Marie-Line itwould have been a much more daunting task to prepare JET operations, monitor progress during the experiments and edit the papers that are compiled here.

Ongena, Jef

2012-07-01

314

Basaltic lava flow surface morphology: Genesis, evolution and impact on flow dynamics  

NASA Astrophysics Data System (ADS)

The emplacement of basaltic lava flows is impacted by a number of interdependent parameters. For the purposes of predictive modeling and hazard assessment, it is necessary to obtain ranges for these parameters and to understand how they are dependent on each other. This dissertation includes several studies to infer lava flow emplacement parameters and their relationships to one another from the surface morphology preserved on solidified flows. Surface morphology maps of a number of Kilauean lava flows reveal a characteristic lava flow facies evolution that results in a sigmoidal surface morphology evolution with distance. I find that differences in the length scale of the transition relate to the eruption temperature and effusion rate of the lava for the transition onset, and interaction with local topography and resulting enhanced thermal efficiency for the transition length. In addition to examining the flow-scale surface morphology transition, I use a corn syrup-rice suspension to investigate the transition at the local-scale. I find several distinct styles of deformation including clumping, shear zones, and detachment whose onsets follow an inverse relationship between particle concentration and shear rate. Each style of deformation shows progressively enhanced shear localization and any or all of these processes may be responsible for the transition from pahoehoe- to `a`a-type deformation. Lava flow surfaces can also impact flow dynamics, with progressively thickening crusts providing increased resistance to flow as illustrated qualitatively by experiments using polyethylene glycol (PEG) 600 wax. I conduct a series of experiments to characterize the mechanical properties of solidified PEG and find that its strength is 104 times stronger than predicted from flow simulations, suggesting that a sub-surface visco-elastic layer, rather than the solidified crust, provides the primary resistance to PEG, and by analog, lava flows. Finally, I develop a computational code to identify alignments of volcanic vents, which act as an indicator of the tectonic stress field at the time of emplacement. The code includes several filtering criteria to limit the detection of spurious alignments. I apply the code to a data set of Pacific Northwest vents and find a slight progressive clockwise rotation of the Cascade trend and westward impingement of the Brothers trend over the last 1 Ma. This dissertation includes published, co-authored materials.

Soule, Samuel Adam

315

Performance Engineering Technology for Scientific Component Software  

SciTech Connect

Large-scale, complex scientific applications are beginning to benefit from the use of component software design methodology and technology for software development. Integral to the success of component-based applications is the ability to achieve high-performing code solutions through the use of performance engineering tools for both intra-component and inter-component analysis and optimization. Our work on this project aimed to develop performance engineering technology for scientific component software in association with the DOE CCTTSS SciDAC project (active during the contract period) and the broader Common Component Architecture (CCA) community. Our specific implementation objectives were to extend the TAU performance system and Program Database Toolkit (PDT) to support performance instrumentation, measurement, and analysis of CCA components and frameworks, and to develop performance measurement and monitoring infrastructure that could be integrated in CCA applications. These objectives have been met in the completion of all project milestones and in the transfer of the technology into the continuing CCA activities as part of the DOE TASCS SciDAC2 effort. In addition to these achievements, over the past three years, we have been an active member of the CCA Forum, attending all meetings and serving in several working groups, such as the CCA Toolkit working group, the CQoS working group, and the Tutorial working group. We have contributed significantly to CCA tutorials since SC'04, hosted two CCA meetings, participated in the annual ACTS workshops, and were co-authors on the recent CCA journal paper [24]. There are four main areas where our project has delivered results: component performance instrumentation and measurement, component performance modeling and optimization, performance database and data mining, and online performance monitoring. This final report outlines the achievements in these areas for the entire project period. The submitted progress reports for the first two years describe those year's achievements in detail. We discuss progress in the last project period in this document. Deployment of our work in CCA components, frameworks, and applications is an important metric of success. We also summarize the project's accomplishments in this regard at the end of the report. A list of project publications is also given.

Malony, Allen D.

2007-05-08

316

Experimental dynamic metamorphism of mineral single crystals  

USGS Publications Warehouse

This paper is a review of some of the rich and varied interactions between non-hydrostatic stress and phase transformations or mineral reactions, drawn mainly from results of experiments done on mineral single crystals in our laboratory or our co-authors. The state of stress and inelastic deformation can enter explicitly into the equilibrium phase relations and kinetics of mineral reactions. Alternatively, phase transformations can have prominent effects on theology and on the nature of inelastic deformation. Our examples represent five types of structural phase changes, each of which is distinguished by particular mechanical effects. In increasing structural complexity, these include: (1) displacive phase transformations involving no bond-breaking, which may produce anomalous brittle behavior. A primary example is the a-?? quartz transition which shows anomalously low fracture strength and tertiary creep behavior near the transition temperature; (2) martensitic-like transformations involving transformation strains dominated by shear deformation. Examples include the orthoenstatite ??? clinoenstatite and w u ??rtzite ??? sphalerite transformations; (3) coherent exsolution or precipitation of a mineral solute from a supersaturated solid-solution, with anisotropy of precipitation and creep rates produced under nonhydrostatic stress. Examples include exsolution of corundum from MgO ?? nAl2O3 spinels and Ca-clinopyroxene from orthopyroxene; (4) order-disorder transformations that are believed to cause anomalous plastic yield strengthening, such as MgO - nAl2O3 spinels; and (5) near-surface devolatilization of hydrous silicate single-crystals that produces a fundamental brittleness thought to be connected with dehydration at microcracks at temperatures well below nominal macroscopic dehydration temperatures. As none of these interactions between single-crystal phase transformations and non-hydrostatic stress is understood in detail, this paper serves as a challenge to field structural geologists to test whether interactions of these types occur in nature, and to theoreticians to reach a deeper understanding of the complex relations between phase transformations, the local state of stress and associated deformation and deformation rates. ?? 1993.

Kirby, S. H.; Stern, L. A.

1993-01-01

317

Ultrafast coherent electron spin control and correlated tunneling dynamics of two-dimensional electron gases  

NASA Astrophysics Data System (ADS)

Electron spins form a two-level quantum system in which the remarkable properties of quantum mechanics can be probed and utilized for many applications. By learning to manipulate these spins, it may be possible to construct a completely new form of technology based on the electron spin degree of freedom, known as spintronics. The most ambitious goal of spintronics is the development of quantum computing, in which electron spins are utilized as quantum bits, or qubits, with properties that are not possible with classical bits. Before these ideas can become reality, a system must be found in which spin lifetimes are long enough and in which spins can be completely controlled. Semiconductors are an excellent candidate for electron spin control since they can be integrated into on-chip devices and produced on a scalable level. The focus of this dissertation is on electron spin control in two different semiconductor systems, namely a two-dimensional electron gas in a modulation-doped quantum well and donor-bound electrons in bulk semiconductors. Both systems have been studied extensively for a variety of purposes. However, the ability to manipulate spins has been elusive. In this dissertation, the first experimentally successful demonstration of electron spin control in a two-dimensional electron gas is presented, in which ultrafast optical pulses induce spin rotations via the optical Stark effect. Donor-bound electron spin manipulation in bulk semiconductors is also investigated in this dissertation. Important information was obtained on the limiting factors that serve to prohibit spin control in this system. By taking these new factors into account, it is our hope that full electron spin control can eventually be accomplished in this system. Finally, through the course of investigating electron spin dynamics, a strange nonlinear optical behavior was observed in a bilayer system, which was determined to result from a coupling of optical interactions with tunneling rates between layers. The data suggest that there is a strong interplay between interlayer and intralayer correlations in this system. Investigations into the nature of this interaction were undertaken and are presented in the last part of this dissertation. This dissertation includes previously published and unpublished co-authored material.

Phelps, Carey E.

318

SMART-1 New Results from 2009-2010  

NASA Astrophysics Data System (ADS)

We present highlights and new SMART-1 results published or obtained in 2009-2010 that are relevant for lunar science and future exploration, in relation with subsequent missions and future landers. SMART-1 is the first of ESA's Small Missions for Advanced Research and Technology [1,2,3]. Its prime objective has been achieved to demonstrate Solar Electric missions (such as Bepi-Colombo) and to test new technologies for spacecraft and instruments. The SMART-1 spacecraft was launched in 2003, as Ariane-5 auxiliary passenger, and reached on 15 March 2005 a lunar orbit 400-3000 km for a nominal science period of six months, with 1 year extension until impact on 3 September 2006. New SMART-1 lunar science and exploration results since 2009 include: - Multiangular photometry of Mare regions allowing to model scattering in planetary regoliths - The study of specific regions at different phase angles allowed to detect variations in regolith roughness - Lunar North and South polar maps and repeated high resolution images have been obtained, giving a monitoring of illumination to study potential sites relevant for future exploration. This permitted to identify SMART-1 peaks of quasi-eternal light and to derive their topography. - The SMART-1 archive observations have been used to support Kaguya, Chandrayaan-1, Chang'E 1, the US Lunar Reconnaissance Orbiter, the LCROSS impact, and to prepare subsequent landers and future human activities and lunar bases. References: [1] Foing, B. et al (2001) Earth Moon Planets, 85, 523 . [2] Racca, G.D. et al. (2002) Earth Moon Planets, 85, 379. [3] Racca, G.D. et al. (2002) PSS, 50, 1323. [4] Grande, M. et al. (2003) PSS, 51, 427. [5] Dunkin, S. et al. (2003) PSS, 51, 435. [6] Huovelin, J. et al. (2002) PSS, 50, 1345. [7] Shkuratov, Y. et al (2003) JGRE 108, E4, 1. [8] Foing, B.H. et al (2003) Adv. Space Res., 31, 2323. [9] Grande, M. et al (2007) PSS 55, 494. [10] Pinet, P. et al (2005) PSS, 53, 1309. [11] Josset J.L. et al (2006) Adv Space Res, 37, 14. [12] Foing B.H. et al (2006) Adv Space Res, 37, 6. Co-authors: B.H. Foing, B. Grieger, D. Koschny, J.-L. Josset, S. Beauvivre, V. Kaydash, Y. Shkuratov, K. Muinonen, U. Mall, A. Nathues, B. Kellett, P. Pinet, S. Chevrel, P. Cerroni, M.C. de Sanctis, M.A. Barucci, S. Erard, D. Despan, V. Shevchenko, S. Peters, A. Borst, F. Bexkens, M. Almeida, D. Frew, J.Volp, D. Heather, SMART1 Science Technology Working Team, ESTEC/SRE-S, postbus 299, 2200 AG Noordwijk, NL, Europe

Foing, Bernard

2010-05-01

319

Visualisation of Palaeomagnetic Databases: Progress and Perspectives  

NASA Astrophysics Data System (ADS)

A set of Palaeomagnetic Databases (GPMDB, TRANS, SECVR, SECVRL, PALIN, MAGST) created and developed by Michael McElhinny and his co-authors in nineties are used by researchers all over the world. Their user-riendly interfaces make it unnecessary for users to learn about details of the Microsoft Access software. The next step in the development of these databases lies in the visualisation of data and in the integration of the palaeomagnetic data with Geographical Information Systems (GIS). One of the most popular GIS software among Earth scientists is ArcView. Due to the relative simplicity of the structure of the GPMDB and other databases it quite easy to integrate palaeomagnetic data into GIS. It is just necessary to prepare a database file in DBASE format (using the export option of the Microsoft Access, for example) and then to create a subsequent graphic theme (layer) in ArcView. The wide variety of ArcView options enable the use of graduated colours, labels, and different symbols to emphasise ages, palaeomagnetic directions, or other data features. Palaeomagnetic data may be combined with the geological, tectonic, and other maps using a variety of spherical projections. Palaeomagnetic data may be easily integrated into other GIS-oriented databases, such as geochronological databases. In addition to all traditional services, such as queries, ArcView and supplementary Avenue scripts and Visual Basic programs provide many new possibilities. For example, it is very easy now to choose data from a particular polygon (e.g. craton, terrane, orogenic belt etc.). Users of the new visual database also can instantly create a stereoplot for any selected data subset and to calculate mean directions and palaeopoles. It is also possible to display palaeopoles for the selected group of data and to reconstruct a palaeoposition of the continental block using these poles, or Euler pole of rotation. There are obvious advantages of using the visual database. For example, if there are some errors in the geographical position of some data, in many cases it is easy to find them. It is much easier now to test tectonic hypotheses. For instance, it is possible to compare data from two adjacent terranes to decide the time of their collision. Visual versions of magnetostratigraphy, secular variations and other palaeomagnetic databases will have similar advantages. Working version of visual GPMDB is available from the author by request.

Pisarevsky, S. A.

2003-04-01

320

Evaluation of SMOS L2 soil moisture data over the Eastern Poland using ground measurements  

NASA Astrophysics Data System (ADS)

Validation of SMOS products is vital for their further use in the study of climate and hydrology. Several authors [1,2] have recently evaluated SMOS soil moisture data with an aid of in-situ observations of soil moisture. Collow and Robock have reported a dry bias as compared to in situ observations. Since their results are not much conclusive, they call for further studies using more data. Bircher and co-authors have also noted significant discrepancies between Danish network and SMOS soil moisture. SWEX_POLAND soil moisture network consists of 9 stations located in Eastern Poland. These stations are located on the areas representing variety types of land use: meadows, cultivated fields, wetlands and forests. We have expanded our analysis, as presented in the EGU 2012, using data from all network stations. Similarly as before, we have used three methods in our comparison studies: the Bland-Altman method, concordance correlation coefficient and total deviation index. Using these methods we have confirmed a fair/moderate agreement of SMOS L2 SM data and network observations. Like the other authors we have also noted the significant biases in SMOS soil moisture. However, the general trends in dynamics of soil moisture revealed by SMOS, the SWEX_POLAND network and referred to GLDAS, are in a considerable relevancy. We have shown that the SMOS satellite measurements are reliable, so can be used to detect areas of dry and moist soil. In Poland the trends indicating the growth of agricultural droughts are depicted by SMOS L2 very well, even better than national drought services for the agriculture. It is worth to note that the year 2011 was more variable and drier than the 2010 for Poland. Moreover, SMOS data prove the well-known property of central Poland to be drier than the rest of the country. It is expected that further mitigation of RFI contamination in Poland will be available due to the cooperation of ESA SMOS to the national spectrum control services (UKE). Therefore, we confirm that SMOS is a very valuable source of data, which is going to be used on regional studies related to the climate in Poland. 1. Collow, T.W., A. Robock, J. B. Basara, and B. G. Illston (2012), Evaluation of SMOS retrievals of soil moisture over the central United States with currently available in situ observations, J. Geophys. Res., 117, D09113, doi:10.1029/2011JD017095. 2. Bircher, S., Skou, N., Jensen, K. H.,. Walker, J. P and Rasmussen L. (2012), A soil moisture and temperature network for SMOS validation in Western Denmark, Hydrol. Earth Syst. Sci., 16, 1445-1463, doi:10.5194/hess-16-1445-2012

Usowicz, Jerzy; ?ukowski, Mateusz; S?omi?ski, Jan; Stankiewicz, Krystyna; Usowicz, Bogus?aw; Lipiec, Jerzy; Marczewski, Wojciech

2013-04-01

321

Obituary  

NASA Astrophysics Data System (ADS)

The fusion research community and the Nuclear Fusion Board of Editors have recently lost two of their brightest lights. Dr Derek Robinson passed away on 2 December 2002 and Professor Masahiro Wakatani on 9 January 2003. The career of Dr Robinson spanned forty years. In the first decade thereof, Dr Robinson and his UK colleagues made measurements of Russian tokamaks confirming the good confinement of that system. These historic results led to the enthusiastic development of tokamaks worldwide but also set the example of truly international collaboration that made fusion research unique. In the last decade of his career, Dr Robinson became Director of the United Kingdom fusion energy research programme, actively supporting JET and other European programmes. He was a profound and articulate member of the ITER Technical Advisory Committee. He actively pursued collaboration around the globe, which he started 35 years ago. He thereby strongly promoted plasma physics research on small devices outside the industrialized countries. We appreciate the sound judgment and common sense he brought to the Nuclear Fusion Editorial Board. For a large part of his life as a theoretician, Professor Wakatani was a member of the Faculty of Energy Science at Kyoto University. Like Dr Robinson, he was also closely involved with ITER both as Chair of its Confinement and Transport Expert Group and as a member of the ITER Physics Basis Editors. This group edited the landmark 1999 publication by Nuclear Fusion. Professor Wakatani authored many insightful papers on tokamak and helical toroidal plasmas. He was highly regarded as an inventive theorist and frequently called upon to participate in international workshops. Only a few weeks before his death he submitted, together with five co-authors from three ITER-parties, an extensive and in-depth review article on turbulent transport in toroidal devices to Nuclear Fusion. This manuscript promises to become a salute to the scientific excellence of a great physicist. Dr Robinson and Professor Wakatani have made major contributions to the archive literature and set high standards of excellence. The Nuclear Fusion Board of Editors will strive to assure that the journal will continue to meet and maintain these standards as fusion energy research moves ahead. We, the staff and Editorial Board members of Nuclear Fusion, will miss their help in pursuing this task. F W Perkins, Chairman of the Board of Editors F C Schüller, Editor, also on behalf of the Editors Emeriti and the Editorial Office staff members

2003-02-01

322

The effect of geometry and surface morphology on the optical properties of metal-dielectric systems  

NASA Astrophysics Data System (ADS)

We analyze the effect of geometry and surface morphology on the optical properties of metal-dielectric systems. Using both analytical and numerical modeling, we study how surface curvature affects the propagation of surface plasmon polaritons (SPPs) along a metal-dielectric interface. We provide an intuitive explanation for how the curvature causes the phase front to distort, causing the SPPs to radiate their energy away from the metal-dielectric interface. We quantify the propagation efficiency as functions of the radius of curvature, and show that it depends nonmonotonically on the bend radius. We also show how the surface morphology influences the transmittance and the reflectance of light from disordered metal-dielectric nanocomposite films. The films consist of semicontinuous silver films of various surface coverage that are chemically deposited onto glass substrates. They exhibit a large and broadband reflection asymmetry in the visible spectral range. In order to investigate how the surface morphology affects the asymmetry, we anneal the samples at various temperatures to induce changes in the morphology, and observe changes in the reflection spectra. Our study indicates that the surface roughness and the metal surface coverage are the key geometric parameters affecting the reflection spectra, and reveals that the large asymmetry is due to the different surface roughness light encounters when incident from different side of the film. Additionally, we analyze how thin metal and dielectric layers affect the optical properties of metal-dielectric systems. Using the concept of dispersion engineering, we show that a metal-dielectric-metal microsphere---a metal sphere coated with a thin dielectric shell, followed by a metal shell---support a band of surface plasmon resonances (SPRs) with nearly identical frequencies. A large number of modes belonging to this band can be excited simultaneously by a plane wave, and hence enhancing the absorption cross-section. We also find that the enhanced absorption is accompanied by a plasmon assisted transparency due to an avoided crossing of dominant SPR bands. We demonstrate numerically that both the enhanced absorption and the plasmon assisted transparency are tunable over the entire visible range. We also present an experimental study of light scattering from silica spheres coated with thin semicontinuous silver shells, and attempt to describe their optical response using a modified scaling theory. This dissertation includes previously published co-authored materials.

Hasegawa, Keisuke

323

A system analysis of a suboptimal surgical experience  

PubMed Central

Background System analyses of incidents that occur in the process of health care delivery are rare. A case study of a series of incidents that one of the authors experienced after routine urologic surgery is presented. We interpret the sequence of events as a case of cascading incidents that resulted in outcomes that were suboptimal, although fortunately not fatal. Methods A system dynamics approach was employed to develop illustrative models (flow diagrams) of the dynamics of the patient's interaction with surgery and emergency departments. The flow diagrams were constructed based upon the experience of the patient, chart review, discussion with the involved physicians as well as several physician colleagues, comparison of our diagrams with those developed by the hospital of interest for internal planning purposes, and an iterative process with one of the co-authors who is a system dynamics expert. A dynamic hypothesis was developed using insights gained by building the flow diagrams. Results The incidents originated in design flaws and many small innocuous system changes that have occurred incrementally over time, which by themselves may have no consequence but in conjunction with some system randomness can have serious consequences. In the patient's case, the incidents that occurred in preoperative assessment and surgery originated in communication and procedural failures. System delays, communication failures, and capacity issues contributed largely to the subsequent incidents. Some of these issues were controllable by the physicians and staff of the institution, whereas others were less controllable. To the system's credit, some of the more controllable issues were addressed, but systemic problems like overcrowding are unlikely to be addressed in the near future. Conclusion This is first instance that we are aware of in the literature where a system dynamics approach has been used to analyze a patient safety experience. The qualitative system dynamics analysis was useful in understanding the system, and contributed to learning on the part of some components of the system. We suggest that further data collection and quantitative analysis would be highly informative for identification of system changes to improve quality and safety.

Lee, Robert C; Cooke, David L; Richards, Michael

2009-01-01

324

Response to ?A Madden-Julian Oscillation Event Realistically Simulated by a Global Cloud-Resolving Model?  

SciTech Connect

I agree with the authors that forecasting the Madden-Julian Oscillation (MJO) in a high resolution global model is important for numerous reasons, including improved weather forecast skill beyond 10 days, and resolving small scale features embedded in the MJO that coarse resolution ({approx}100-300km horizontal grid spacing) climate models do not (e.g., tropical cyclones). Unfortunately, the authors promote the (incorrect) overall impression that coarse resolution climate models cannot simulate the MJO by (a) only discussing aspects of works that indicate the poor ability of coarse resolution climate models to simulate the MJO, and (b) by promoting the use of higher resolution models, and the use of embedded two-dimensional cloud resolving models embedded in coarse resolution climate models as the principal methods for realistically representing the MJO because of the difficulty of coarse resolution models 'to estimate the vertical redistribution of heat and moisture by unresolved convective clouds'. Regarding items (a) and (b), I have co-authored two of the works cited by Miura et al. that bemoan the poor ability of coarse resolution climate models to simulate the MJO, and indeed simulating the MJO in coarse resolution climate models is a grand challenge. However, I would like to draw to their attention to work that has demonstrated that two different coarse resolution climate models, using conventional parameterizations of convection and clouds, can represent the MJO with high fidelity. In the later study, where more complete model diagnostics were available, important aspects of the MJO that were realistically represented included the relationship between convection and low-level moisture convergence, surface fluxes, the vertical structure of winds and divergence, and important air-sea interactions. Additionally, regarding item (b), convection is certainly of central importance in representing the MJO, but it is the interaction of convection (parameterized or otherwise) with other aspects of the model physics that is important. Thus, it is the implementation of the full physics package that is relevant, not simply the manner in which convection is represented. The issue at hand is to determine what aspects of the physics present in the high resolution (and embedded 2-dimensional cloud resolving model) simulations are essential for incorporation into coarse resolution climate model parameterizations in order for them to adequately represent the MJO. In the foreseeable future, models used for climate and climate change studies will continue to require convective parameterization in order to produce simulations that span decadal to centennial time scales to estimate the impact of anthropogenic influences on the statistics of weather variability and extremes. As such, intercomparison across different classes of modeling is essential to better understand the physics relevant to the climate system.

Sperber, K R

2007-12-18

325

The decrease of dopamine D?/D? receptor densities in the putamen and nucleus caudatus goes parallel with maintained levels of CB? cannabinoid receptors in Parkinson's disease: a preliminary autoradiographic study with the selective dopamine D?/D? antagonist [³H]raclopride and the novel CB? inverse agonist [¹²?I]SD7015.  

PubMed

Cannabinoid type-1 receptors (CB?Rs) modulate synaptic neurotransmission by participating in retrograde signaling in the adult brain. Increasing evidence suggests that cannabinoids through CB?Rs play an important role in the regulation of motor activities in the striatum. In the present study, we used human brain samples to examine the relationship between CB?R and dopamine receptor density in case of Parkinson's disease (PD). Post mortem putamen, nucleus caudatus and medial frontal gyrus samples obtained from PD patients were used for CB?R and dopamine D?/D? receptor autoradiography. [¹²?I]SD7015, a novel selective CB?R inverse agonist, developed by a number of the present co-authors, and [³H]raclopride, a dopamine D?/D? antagonist, were used as radioligands. Our results demonstrate unchanged CB?R density in the putamen and nucleus caudatus of deceased PD patients, treated with levodopa (L-DOPA). At the same time dopamine D?/D? receptors displayed significantly decreased density levels in case of PD putamen (control: 47.97 ± 10.00 fmol/g, PD: 3.73 ± 0.07 fmol/g (mean ± SEM), p<0.05) and nucleus caudatus (control: 30.26 ± 2.48 fmol/g, PD: 12.84 ± 5.49 fmol/g, p<0.0005) samples. In contrast to the putamen and the nucleus caudatus, in the medial frontal gyrus neither receptor densities were affected. Our data suggest the presence of an unaltered CB?R population even in late stages of levodopa treated PD. This further supports the presence of an intact CB?R population which, in line with the conclusion of earlier publications, may be utilized as a pharmacological target in the treatment of PD. Furthermore we found discrepancy between a maintained CB?R population and a decreased dopamine D?/D? receptor population in PD striatum. The precise explanation of this conundrum requires further studies with simultaneous examination of the central cannabinoid and dopaminergic systems in PD using higher sample size. PMID:22421165

Farkas, Szabolcs; Nagy, Katalin; Jia, Zhisheng; Harkany, Tibor; Palkovits, Miklós; Donohou, Sean R; Pike, Victor W; Halldin, Christer; Máthé, Domokos; Csiba, László; Gulyás, Balázs

2012-03-07

326

Seismic structure of the western U.S. mantle and its relation to regional tectonic and magmatic activity  

NASA Astrophysics Data System (ADS)

Vigorous convective activity in the western U.S. mantle has long been inferred from the region's widespread intra-plate crustal deformation, volcanism, and high elevations, but the specific form of convective activity and the degree and nature of lithospheric involvement have been strongly debated. I design a seismic travel-time tomography method and implement it with seismic data from the EarthScope Transportable Array and complementary arrays to constrain three-dimensional seismic structure beneath the western U.S. Tomographic images of variations in compressional velocity, shear velocity, and the ratio of shear to compressional velocity in the western U.S. mantle to a depth of 1000 km are produced. Using these results I investigate mantle physical properties, Cenozoic subduction history, and the influence of small-scale lithospheric convection on regional tectonic and magmatic activity, with particular focus on southern California and the Pacific Northwest. This dissertation includes previously published co-authored material. Chapter II presents a travel-time tomography method I designed and first implemented with data from southern California and the surrounding southwestern U.S. The resulting images provide a new level of constraint on upper mantle seismic anomalies beneath the Transverse Ranges, southern Great Valley, Salton Trough, and southwestern Nevada volcanic field. Chapter III presents tomographic images of the western U.S. mantle, identifies upper mantle volumes where partial melt is probable, and discusses implications of the apparently widespread occurrence of gravitational instabilities of continental lithsophere and the complex geometry and buoyancy of subducted ocean lithosphere imaged beneath the western U.S. In Chapter IV, tomography images are used in conjunction with geologic constraints on major transitions in crustal deformation and magmatism to construct a model for Pacific Northwest evolution since the Cretaceous. Accretion in the Pacific Northwest at 55-50 Ma is suggested to stimulate roll-back of the flat subducting Farallon slab. This change in convergent margin structure is further suggested to drive the short-lived Challis magmatic trend and trigger the southward propagating Eocene-Oligocene transition from the Laramide orogeny to widespread crustal extension and ignimbrite magmatism.

Schmandt, Brandon

327

Ecologies of parental engagement and preservice teacher education in science. The design, development, and implementation of a multimedia case-based environment: "PARENTS"  

NASA Astrophysics Data System (ADS)

This study discusses the design, development, and implementation of the PARENTS multimedia case-based environment, which was developed as a response to the challenging lack of research studies that address parental engagement in (science) education, in high poverty urban areas, in relation to the preservice teacher education in science. Its main purpose is to help preservice science teachers explore and reflect on the themes of parental engagement in those settings. The design process of PARENTS relied upon two frameworks: (a) development research and (b) constructivist case-based environments, from which a design conceptual framework was derived, consisted of a set of six interrelated principles: (1) Authenticity, (2) Interpretation and Argumentation Construction, (3) Multiple Perspectives, (4) Rich, Multi-modal, Non-Linear Information Resources, (5) Scaffolding and Support, and (6) Multimedia Case-Based Learning and Instruction. The first implementation of PARENTS occurred in a preservice science teacher education course and it addressed two research questions: (a) how are preservice science teachers' beliefs and ideas about parental engagement in high poverty urban school settings crafted, mediated, or expressed within a graduate course that draws upon the PARENTS environment? (b) what are the design features and/or content parts of PARENTS that enable or enhance student's thinking about parental engagement in high poverty urban school settings? The exploratory and descriptive character of the study directed us towards the use qualitative methods of data collection and analysis (embedded case study). The data analysis revealed three emerging cross-cutting themes in the evolvement of the preservice teachers' beliefs around parental engagement: (a) less deficit model thinking, (b) shared responsibility for participation, and (c) redefining and co-authoring a new space of science education for parental engagement. Also, the analysis of the user-interface interaction and the users' feedback revealed comments and suggestions in three areas: (1) the system navigation, familiarity and technical difficulties, (2) the key dimensions of the PARENTS multimedia design, and (3) the integration of PARENTS into a teacher education course. The conclusions, implications and future directions are discussed in regard to the two major fields interweaved in PARENTS and this research study: (a) the design and implementation of multimedia case-based learning environments, and (b) the research area of preservice (science) teacher education and parental engagement.

Roushias, Christakis

328

Wilhelm Winkler (1842-1910) - a Thuringian private astronomer and maecenas  

NASA Astrophysics Data System (ADS)

Wilhelm Winkler was born in 1842 in Eisenberg, Thuringia, as the son of a lawyer. After attending the trading high school in Gera, Winkler worked as a merchant in Eisenberg, following in the footsteps of his grandfather. In 1875 he gave up this trade and devoted his time entirely to astronomy. Advised by Carl Bruhns, director of the Leipzig University Observatory, he established an observatory on his estate in Gohlis near Leipzig. From 1878 Winkler regularly observed sunspots; other fields of his observational interests were comets, occultations of stars by the Moon, and Jupiter's satellites. In 1887 he went to Jena, where he contacted Ernst Abbe, who was the head of the Jena observatory, too. For some years, Winkler's instruments were used in the new observatory erected by Abbe, which replaced the old Ducal Observatory of the Goethe era. Winkler donated the precision pendulum clock and some other instruments to this observatory. He also offered his observational assistance whenever it was wanted. In 1893 Winkler built up his own observatory in Jena and published annual reports on his work in the Vierteljahrsschrift of the Astronomische Gesellschaft. His observational results mainly appeared in the journal Astronomische Nachrichten. In 1902 he was awarded an honorary doctor's degree by the Philosophical Faculty of Jena University. However, at that time his physical constitution began gradually to fade. He lost his left eye due to a sarcoma, and finally he died at the age of 68. In his will, he left 100 000 Mark in form of securities to Jena University (Winkler Foundation). The University Observatory got his 4.5 m dome, the transport of which from his residence to the final site was also paid for by him, several instruments, and a lot of books. In 1936 Winkler's dome was closed by the University. The observatory was transferred from the University to the Zeiss works in exchange for the observatory in the Jena Forst. Zeiss sponsored the reconstruction of the old dome and its equipment with a telescope and, thus, laid the base for the modern Urania Popular Observatory. Please note: The printed version contains an error: Unfortunately, Reinhard E. Schielicke was not indicated as co-author of this paper.

Weise, Wilfried; Dorschner, Johann; Schielicke, Reinhardt E.

329

Homicide or suicide: the killing of suicidal persons by law enforcement officers.  

PubMed

This paper presents 15 deaths of suicidal persons in Oregon and Florida who, by their behavior, sufficiently provoked law enforcement officers into killing them. Four deaths were certified as suicide, one as undetermined and ten as homicide. All of the deaths are individually described in detail and their case characteristics are presented in a table. The method of study is a descriptive analysis of the case characteristics, including 21 variables which are determined to be relevant to the classification of death. The variables were grouped into six categories: (a) personal information; (b) criminal behavior during the fatal incident; (c) dangerous behavior during the fatal incident; (d) toxicological data; (e) mental illness information; and (f) certification data. From the analysis, reasons for the opinions on manner of death classification are presented. All incidents were perceived as life-threatening to law officers, family members, or hostages. All victims were male except one, and all were Caucasian except two. All victims resisted arrest and verbally threatened homicide during the fatal incident. Two-thirds of the victims took hostages. All victims possessed an apparent handgun or other weapon (knife, iron bar). All victims posed their weapon and threatened others during the incident, 60% of victims actually used the weapon with apparent intent to inflict damage to others. 40% of victims were intoxicated with alcohol but other drug-involvement was uncommon. Seven of 15 had previous suicide attempts, 40% had medically documented psychiatric diagnoses and 60% had reasonable historical evidence of psychiatric diagnoses, most commonly depression or substance abuse. One of the co-authors presents the case for some of the deaths to be certified as suicides, whereas two present the case for all to be certified as homicide. A brief discussion of psychiatric issues is also presented concerning individuals who use others to commit suicide and who may engage in dangerous and/or criminal behavior to do so. A major conclusion is that there is lack of a unified opinion on death certification procedures for individuals who have provoked law enforcement officers to kill them. For such cases, it is recommended that professional organizations of medical examiners/coroners develop guidelines to promote consistency in death certification practices including manner of death classification and selection of death certificate wording so that "police-assisted suicide" may be appropriately reported and studied. PMID:9456524

Wilson, E F; Davis, J H; Bloom, J D; Batten, P J; Kamara, S G

1998-01-01

330

Thermoremanent magnetization (TRM) and Thellier laws in single-domain particles with mixed anisotropy  

NASA Astrophysics Data System (ADS)

Thermoremanent magnetization (TRM) and viscous remanent magnetization (VRM) are two of the main components of remanence in rocks, and an understanding of their origins is essential for paleomagnetism. David Dunlop has made important experimental and theoretical contributions to almost every aspect of these phenomena. On the theoretical side he and his co-authors have applied Néel's single-domain (SD) theory to thermoviscous overprints and thermal fluctuation analysis; made numerous extensions to multidomain theories of TRM; and done micromagnetic modeling of TRM. Micromagnetic models of TRM face several challenges because of the inherent complexity of nonuniform magnetization. A lot of attention has been focussed on finding the height of the energy barrier between states, and significant progress has been made in this area. However, two other problems have mostly been overlooked. First, in Néel theory the energy barrier is a one-dimensional maximum, but in general it is a multidimensional saddle point. The shape of this saddle point affects relaxation rates between states. Second, there are several states and each state is connected to more than one other state. The combined effects of all these transitions must be determined somehow. These challenges are explored in a comparatively simple system, an SD particle with both cubic and uniaxial anisotropy. In such a particle there are up to eight remanent states and each state is connected to as many as four other states. Relaxation rates are calculated for saddle points using Kramers theory for high damping. The multiple connections are represented by a master equation. This equation is very difficult to solve for nonzero field. For small fields the master equation is reformulated using projection matrices and linear perturbation theory is used. The following results were obtained. In zero field there are two or three blocking temperatures depending on the geometry. A large field splits these blocking temperatures into as many as eight. Fortunately, to first order a small field has no effect on the blocking temperature. An important consequence is that the particle satisfies the Thellier laws for paleointensity.

Newell, A. J.

2005-12-01

331

Northern Eurasia Earth Science Partnership Initiative (NEESPI) during the past 12 months: An Overview of the Current Status  

NASA Astrophysics Data System (ADS)

Four years ago NEESPI was launched with the release of its Science Plan (http://neespi.org). Gradually, the Initiative was joined by numerous international projects launched in EU, Russia, the United States, Canada, Japan, and China. Currently, serving as an umbrella for more than 130 individual research projects (always with an international participation) with a budget close to 15M US dollars annually, the Initiative is in full swing. Several NEESPI Workshops and Sessions at the International Meetings were held since April 2008 when we presented our Status Report to the Assembly the last time. The Workshops strengthen the NEESPI grasp on climatic and hydrological modeling and regional NEESPI components in the Arctic and Eastern Europe. Two volumes of the NEESPI Workshop Proceedings have been published recently (Groisman and Reissell 2009; Groisman and Ivanov 2009), one book (Gutman 2009) is currently in press, and the Initiative progress overview paper is scheduled to appear in the May issue of The Bulletin of the American Meteorological Society. Following the recommendations of the Aspen Global Change Institute Workshop (http://neespi.org/meetings/Aspen2007_Workshop_Report_web.pdf), the NEESPI research focus has begun to shift from organizing improved environmental monitoring of the region and studying of individual environmental processes towards modeling and its ability to project the future state of climate, environment, and societies in the NEESPI domain. Soon after the past EGU Meeting in April 2008, this focus within NEESPI, received an intergovernmental level of support being included in a Memorandum of Understanding for Collaboration in the Fields of Meteorology, Hydrology, and Oceanography between the U.S. National Oceanic and Atmospheric Administration and the Russian Federal Service for Hydrometeorology and Environmental Monitoring. The new focus will require a higher level of integration of observation programs, process studies, and modeling, and across disciplines. References: Groisman P.Ya. and S.V. Ivanov (eds.) 2009: Regional Aspects of Climate-Terrestrial-Hydrologic Interactions in Non-boreal Eastern Europe. Springer, Amsterdam, The Netherlands, 251 pp. Groisman, P.Ya. and A. Reissell (eds.) 2009: Proceedings of the Northern Eurasia Earth Science Partnership Initiative (NEESPI) Regional Science Team Meeting devoted to the High Latitudes, 2-6 June, Helsinki,Finland. iLEAPS Science Report Series No 1, University of Helsinki Press, Helsinki, Finland [Available also at http://www.iLEAPS.org]. Groisman, P.Ya., and 27 Co-Authors, 2009: The Northern Eurasia Earth Science Partnership: An Example of Science Applied To Societal Needs. Bull. Amer. Meteorol. Soc. (in press). Gutman, G. (ed.) 2009: Arctic land cover and land use in a changing climate: Focus on Eurasia. Springer, Amsterdam, The Netherlands (in press).

Groisman, P. Ya.; Kattsov, V. M.; Lawford, R. G.

2009-04-01

332

SIOExplorer: Overview, Initial Results and Next Steps  

NASA Astrophysics Data System (ADS)

Data, documents and images from 795 expeditions by the Scripps Institution of Oceanography (SIO) since 1903 are becoming web-accessible for both education and research through the new SIOExplorer project (http://SIOExplorer.ucsd.edu), which is a collection in the overall NSF-funded National Science Digital Library (www.nsdl.org). The collaborative effort includes researchers at SIO, computer scientists from the San Diego Supercomputer Center (SDSC), and archivists and librarians from the UCSD Library. The co-authors of this paper tested a shipboard prototype during a Floating Digital Library Workshop from New Zealand to Samoa on R/V Melville in March, 2002. General purpose tools have been developed to automate collection development, manage metadata, and geographically search the library, as discussed in other presentations in this session. In the initial year of operation, the biggest challenge has been wrestling with the volume and variability of data and documents. Shipboard sensors, data volumes, and organizational structures have evolved greatly over the decades, particularly with 244 multibeam expeditions since 1982. Considerable success came after introducing the concept of a Canonical Cruise Data Structure (CCDS) with nine basic categories that seem to capture the essential characteristics of data practices since the 1960's. Automatic software pulls data into the CCDS from diverse source directories and media, guided by a template with rules for priority and filenames. Almost all metadata are harvested automatically into simple "metadata interchange format" (.mif) files, one for each "arbitrary digital object" (ADO) in the CCDS. The metadata are placed in an Oracle database, and the associated data are managed by the SDSC Storage Resource Broker on various disk and automatic tape silo systems. The system is extensible to various domains and data types, including geochemistry, image archives, multibeam bathymetry, reports and publications. A Java Metadata Object Browser and Editor (MOBE) expands or hides the complexity for each domain, as needed. A prototype interactive CruiseViewer with both Java and html approaches will be demonstrated. As the second year of the project begins, greater emphasis will be placed on search and display tools. At-risk data on shipboard magnetic tapes will be migrated to RAID systems and tape silos. Public outreach will begin at the Birch Aquarium and other locations. A workshop will be held at Scripps in September 2003, coinciding with the hosting of the Oceans 2003 meeting and the 100th Anniversary of SIO. These efforts are supported by the NSF NSDL and ITR programs and by SIO institutional funds.

Miller, S. P.; Helly, J. J.; Africa, M.; Peckman, U.; Day, D.; Clark, D.

2002-12-01

333

WRF simulations of the atmospheric boundary layer evening transitions during the BLLAST field campaign  

NASA Astrophysics Data System (ADS)

The Planetary Boundary Layer (PBL) is mainly ruled by both mechanical and thermal turbulence, and shows an evident diurnal cycle. In the evening transitional period, decay in turbulent kinetic energy occurs, but all the mechanisms behind this decay are still not well understood. In this framework, the BLLAST (Boundary Layer Late Afternoon and Sunset Turbulence) project aims to improve the knowledge on the physical processes taking place during the late afternoon and evening transition in the lower troposphere. The BLLAST field campaign was organized in Lannemezan (France) from 14th June to 8th July 2011 [1]. Both in situ measurements (i.e., with meteorological towers, surface based instruments, tethered balloons…) and remote sensors (i.e., SODAR, scintillometer…) were used for this purpose, and two different approaches were developed: vertical structure of the boundary layer and spatial heterogeneity. Besides, Numerical Weather Prediction (NWP) models have exhibited substantial difficulties to properly simulate the diurnal cycle in the atmosphere and also the PBL afternoon and evening transition. Typically, some errors are found in air temperature and wind speed close to the surface. Regarding this fact, the main goal of this work is to study how the mesoscale model WRF (Weather Research and Forecast) performs simulations of the evening transition during the BLLAST field campaign. In particular, it is tested for permutations of different PBL and Land Surface Model (LSM) schemes. We try to understand why some differences in model results appear. A comparison between observations and combinations of PBL and LSM parameterizations is shown, testing the sensitivity to these options. We specifically evaluate the surface radiation budget (out- and incoming long- and shortwave radiation), and the surface energy budget variables (latent and sensible heat fluxes, as well as soil heat flux). Furthermore, the vertical profiles of some key variables (such as potential temperature or wind velocity) are investigated and connected to surface variables values. [1] Lothon, M. and co-authors (2012): The Boundary-Layer Late Afternoon and Sunset Turbulence field experiment. Paper 14B.1, 20th Symposium on Boundary-Layers and Turbulence, Boston, MA, Amer. Meteor. Soc., 12 pp.

Sastre Marugán, Mariano; Steeneveld, Gert-Jan; Yagüe, Carlos; Román-Cascón, Carlos; Maqueda, Gregorio; van de Boer, Anneke

2013-04-01

334

Topics in supersymmetry breaking and gauge/gravity dualities  

NASA Astrophysics Data System (ADS)

This design-based study was the first empirical investigation of a new model of learning and instruction called Knowledge Community and Inquiry (KCI). In KCI, students are engaged as a learning community as they work on scaffolded inquiry activities that target specific science learning objectives. Although community-oriented approaches have been successful at the elementary level, there has been relatively little uptake of such methods at the secondary school level -- particularly in science. The pedagogical framework of KCI addresses the challenges of community models by blending established inquiry based approaches with community-oriented pedagogy. This dissertation tested the validity of KCI by designing, implementing, and empirically evaluating a curriculum based on the KCI model. This was achieved through curriculum trials involving two separate cohorts of grade-ten biology students (n = 102; n = 112). The first implementation consisted of a two-week physiology lesson that engaged students in co-authoring wiki artifacts about human system diseases, which students then used as a resource for solving medical case studies. The second implementation, an eight-week lesson on Canada's biodiversity, was a deeper application of the model, and focused on students' collaborative processes during the construction of their wiki-based knowledge repository. In both cases, the curriculum was evaluated according to its design, enactment, and learning outputs, as evidenced by students' knowledge artifacts and performance on the final exam. Technology scaffolds ensured that students focused on the physiology and biodiversity science curriculum expectations. Analyses of the data revealed that KCI engaged students in collaborative learning processes that were characteristic of a knowledge community. Additionally, final exam scores demonstrated increased learning performance when compared to those from previous years where students did not participate in KCI. The findings from this research provide the first empirical support for KCI, and demonstrate its potential for engaging secondary science students in the kinds of collaborative inquiry processes of authentic knowledge communities. This dissertation provides insight into the conditions necessary for such engagement, and contributes design recommendations for blending knowledge community and inquiry in secondary school science curriculum.

Peters, Vanessa Lynn

335

Satellite Altimetry, Software, Fracture Zones and Seamounts  

NASA Astrophysics Data System (ADS)

William F. Haxby was one of the pioneers in using satellite altimetry to characterize the ocean floor. His early work culminated in the release of his famous 1987 "Gravity map of the World's Oceans" which was based on the 3-month long Seasat mission. This map revolutionized our knowledge of seafloor tectonic fabric and spawned numerous seagoing expeditions to map in further detail the many features, such as the Louisville and Foundation seamount chains, which Bill had imaged from the comfort of his office chair in the early 1980s. It was truly inspiring to experience him programming his computer to do all kinds of tasks. His unique expertise greatly influenced how many of us approach not just science but all undertakings that can conceivably be automated on a computer. For instance, Bill's mapping tools inspired GMT (Wessel and Smith, 1991); the early version even borrowed a few low-level projection routines translated to C from his Fortran library. Bill would go on to become a master of Java programming, developing such items as the GeoMapApp tool. Because of the great spacing between Seasat profiles, Bill developed gridding software that could be made aware of lineated features and thus produce grids that retained the continuity of such features across the data gaps. One benefit of this approach was the complete and improved mapping of linear features such as fracture zones and the subtle gravity undulations that now bears his name. Bill dedicated much of his work to study and characterize the large-offset Pacific fracture zones and with co-authors made long-lasting contributions to the understanding of their evolution, including the importance of thermal stresses. On the other hand, the track spacing made studies of seamounts more challenging, as many seamounts would fit entirely within the diamond-shaped data gaps. Nevertheless, Bill identified several large seamounts in the southern oceans that were unknown at the time. Data from the Geosat and ERS missions would later simplify seamount detection considerably by providing much denser coverage. This talk will review our knowledge of the global seamount distribution and present new results using the improved retracked data from Sandwell and Smith.

Wessel, P.; Kim, S.

2006-12-01

336

Selective preparation of nickel silicides and nickel germanides from multilayer reactants  

NASA Astrophysics Data System (ADS)

This dissertation investigates the application of a multilayer-based synthetic technique to the phase selective preparation of nickel silicides and nickel germanides. This preparative technique employs modulated elemental multilayers with ultrathin repeating subunits as initial reactants. Complete interdiffusion is effected with moderate annealing, producing an amorphous intermediate state prior to nucleation of a crystalline phase. This technique enables the direct preparation of a variety of nickel silicide and nickel germanide phases without the formation of unwanted crystalline intermediates. The success of this preparative strategy requires that the repeating subunit of the multilayer reactant be below some critical thickness, such that complete mixing precedes first phase formation. The variation in the product of equiatomic nickel-silicon multilayer reactions near the critical thickness is investigated. Using x-ray reflectivity (XRR) and x-ray diffraction (XRD), two reaction mechanisms intermediate between conventional interfacial reaction and the sub-critical thickness reaction are identified. By varying multilayer composition while maintaining the repeating subunit below the critical thickness, the selective formation of Ni31 Si12, delta-Ni2Si, theta-Ni2Si, NiSi, and NiSi2 is demonstrated. Of particular note is the preparation of theta-Ni2Si, which forms in conditions under which it is metastable with respect to a low temperature phase. Comparison with first phase nucleation in non-layered amorphous precursors suggests that the multilayer preparative method has a high propensity towards homogeneous phase formation. The application of this synthetic strategy to nickel germanides enables the preparation of a number of high temperature nickel germanides at temperatures below 200°C. This preparative technique favors the formation of NiAs-type nickel germanides, suggesting that the ordering in the amorphous phase may closely reflect the NiAs structure. Preliminary results on the preparation of ternary nickel-silicon-germanium compounds are discussed. The critical length scales in silicon-germanium multilayers are determined. The preparation of NiAs-type compounds of the form NiSi 1-xGex is reported. This dissertation includes my previously published and co-authored materials.

Jensen, Jacob Michael

337

Crustal and upper mantle structure beneath the Galapagos arechipelago from seismic tomography  

NASA Astrophysics Data System (ADS)

To explain the origin of several distinct aspects of the Galapagos volcanic hotspot, such as the broad geographical extent of recent volcanism and the unusual pattern of geochemical anomalies, we conducted seismic tomography studies of the upper mantle and crust beneath the Galapagos Archipelago. The studies combine measurements of group and phase velocities of surface waves and delay times of body waves. We find that upper mantle seismic velocities are lower than those beneath other regions of comparable age in the Pacific and consistent with an excess temperature of 30 to 150°C and ˜0.5% melt. We attribute the excess temperature and presence of melt to an upwelling thermal mantle plume. Crustal seismic velocity is up to 25% lower than that of very young crust at the East Pacific Rise (EPR) and is comparable to that of Hawaii, which we attribute to heating by increased intrusive activity above the Galapagos plume and the construction of a highly porous volcanic platform. In addition, we find that the Galapagos hotspot is underlain by a high-velocity region whose thickness varies from 40 to 100 km. The tomographic images reveal that the upwelling mantle plume tilts northward (towards the nearby Galapagos Spreading Center) as it rises and then spreads laterally when it reaches the bottom the lid. The lid, which we attribute to residuum from melting, is thickest where it is farthest from the spreading center, suggesting that ridge processes may affect the generation and amount of thinning of the residuum layer. In addition, the thickness of the lid correlates well with the geographical pattern of geochemical anomalies of erupted lavas, suggesting that the lid may control the final depth of decompression melting. We conclude that many of the distinct characteristics of the Galapagos can be attributed to the interaction of the upwelling plume with the lid and the nearby ridge. We further suggest that the ridge affects the geometry of plume upwelling in the upper mantle and also the pattern of lateral spreading of the plume due to its effect on the thickness of the residuum layer. This dissertation includes previously published co-authored material.

Villagomez Diaz, Darwin R.

338

The National Adult Inpatient Survey conducted in the English National Health Service from 2002 to 2009: how have the data been used and what do we know as a result?  

PubMed Central

Background When it was initiated in 2001, England's national patient survey programme was one of the first in the world and has now been widely emulated in other healthcare systems. The aim of the survey programme was to make the National Health Service (NHS) more "patient centred" and more responsive to patient feedback. The national inpatient survey has now been running in England annually since 2002 gathering data from over 600,000 patients. The aim of this study is to investigate how the data have been used and to summarise what has been learned about patients' evaluation of care as a result. Methods Two independent researchers systematically gathered all research that included analyses of the English national adult inpatient survey data. Journals, databases and relevant websites were searched. Publications prior to 2002 were excluded. Articles were also identified following consultation with experts. All documents were then critically appraised by two co-authors both of whom have a background in statistical analysis. Results We found that the majority of the studies identified were reports produced by organisations contracted to gather the data or co-ordinate the data collection and used mainly descriptive statistics. A few articles used the survey data for evidence based reporting or linked the survey to other healthcare data. The patient's socio-demographic characteristics appeared to influence their evaluation of their care but characteristics of the workforce and the. At a national level, the results of the survey have been remarkably stable over time. Only in those areas where there have been co-ordinated government-led campaigns, targets and incentives, have improvements been shown. The main findings of the review are that while the survey data have been used for different purposes they seem to have incited little academic interest. Conclusions The national inpatient survey has been a useful resource for many authors and organisations but the full potential inherent in this large, longitudinal publicly available dataset about patients' experiences has not as yet been fully exploited. This review suggests that the presence of survey results alone is not enough to improve patients' experiences and further research is required to understand whether and how the survey can be best used to improve standards of care in the NHS.

2012-01-01

339

Remote measurement of gravel-bed river depths and analysis of the geomorphic response of rivers to canals and small dams  

NASA Astrophysics Data System (ADS)

This dissertation investigates the potential impacts of canals and small dams on gravel-bed rivers and methods for documenting those impacts. First, I evaluate the potential for mapping channel depths along the McKenzie River, OR, using 10 cm resolution optical aerial imagery with a hydraulically-assisted bathymetry (HAB-2) model. Results demonstrate that channel depths can be accurately mapped in many areas, with some imagery limitations. The HAB-2 model works well in the majority of the river (R2=0.89) when comparing modeled to observed depths, but not in areas of shadow, surface turbulence, or depths >1.5 m. Next, I analyze the relative effects of a small dam and two diversion canals on sediment distribution along bars of the lower McKenzie River. The typical pattern of downstream fining is disrupted at each feature and several tributaries, particularly in the "reduced water reaches" below canal outtakes. Most modeled discharge values necessary to mobilize bar sediments fall at or below the 2-year flood return interval, with the remaining at or below the 5-year flood return interval, generally reflecting the D50 values at each bar (20-115 mm). The third analysis investigates the potential to document geomorphic impacts of small dams in Oregon at ecoregion extents using air photos and publically available data sets. This analysis highlights data disparity with respect to the collecting agency's mission and the difficulty of using remote sensing for small dams. Though the imagery was not useful in evaluating small dam impacts due to resolution and feature size, the data were useful in mapping the small dam distribution across Oregon and each ecoregion. Sixty-one percent of Oregon land is located in the catchment of at least one small dam and the greatest number of dams per area is in the Willamette Valley ecoregion. Overall, this research suggests that, while the application of these techniques must be improved, our ability to observe, study, and understand rivers is enhanced by remote sensing advancements and the combined use of these methods in river restoration and management. This dissertation includes previously published and co-authored material.

Walther, Suzanne Corinna

340

Mitochondrial dynamics and optical conformation changes in DsRed as studied by Fourier imaging correlation spectroscopy  

NASA Astrophysics Data System (ADS)

Novel experiments that probe the dynamics of intracellular species, including the center-of-mass displacements and internal conformational transitions of biological macromolecules, have the potential to reveal the complex biochemical mechanisms operating within the cell. This work presents the implementation and development of Fourier imaging correlation spectroscopy (FICS), a phase-selective approach to fluorescence spectroscopy that measures the collective coordinate fluctuations of fluorescently labeled microscopic particles. In FICS experiments, a spatially modulated optical grating excites a fluorescently labeled sample. Phase-synchronous detection of the fluorescence, with respect to the phase of the exciting optical grating, can be used to monitor the fluctuations of partially averaged spatial coordinates. These data are then analyzed by two-point and four-point time correlation functions to provide a statistically meaningful understanding of the dynamics under observation. FICS represents a unique route to elevate signal levels, while acquiring detailed information about molecular coordinate trajectories. Mitochondria of mammalian cells are known to associate with cytoskeletal proteins, and their motions are affected by the stability of microtubules and microfilaments. Within the cell it is possible to fluorescently label the mitochondria and study its dynamic behavior with FICS. The dynamics of S. cerevisiae yeast mitochondria are characterized at four discrete length scales (ranging from 0.6--1.19 mum) and provide detailed information about the influence of specific cytoskeletal elements. Using the microtubule and microfilament destabilizing agents, Nocodazole and Latrunculin A, it is determined that microfilaments are required for normal yeast mitochondrial motion while microtubules have no effect. Experiments with specific actin mutants revealed that actin is responsible for enhanced mobility on length scales greater than 0.6 mum. The versatility of FICS expands when individual molecules are labeled with fluorescent chromophores. In recent experiments on the tetrameric fluorescent protein DsRed, polarization-modulated FICS (PM-FICS) is demonstrated to separate conformational dynamics from molecular translational dynamics. The optical switching pathways of DsRed, a tetrameric complex of fluorescent protein subunits, are examined. An analysis of PM-FICS coordinate trajectories, in terms of 2D spectra and joint probability distributions, provides detailed information about the transition pathways between distinct dipole-coupled DsRed conformations. This dissertation includes co-authored and previously published material.

Senning, Eric Nicolas

341

On the wavelength of self-organized shoreline sand waves  

NASA Astrophysics Data System (ADS)

Shoreline sand waves are undulations of the shoreline that extend into the bathymetry up to a certain depth. Here we will focus on self-organized sand waves that form due to shoreline instability in case of very oblique wave incidence (Ashton et al., 2001). The model of Ashton and co-authors did not predict any wavelength selection for the emerging sand waves whereas Falqués and Calvete (2005) predicted a wavelength selection in the range 4-15 km. This difference is attributable to that Falqués and Calvete (2005) computed wave refraction and shoaling over the actual curvilinear depth contours while Ashton et al. (2001) assumed locally rectilinear and parallel contours. Although there exist shoreline features at a larger scale (Ashton et al. 2001; Falqués et al. 2011) sand waves at a few km scale are more common (Ruessink and Jeuken, 2002; Davidson-Arnott and van Heyningen, 2003; Falqués et al., 2011; Medellin et al., 2008) . While their characteristic wavelength is a robust model output (Falqués and Calvete, 2005; Uguccioni et al., 2006; van den Berg et al., 2011) the physical reasons for the existence of a wavelength selection are still unknown. Furthermore, the parameter dependence of the dominant wavelength, Lm, is largely unexplored. In particular, the disparity between the large length scale of sand waves and the relevant length scales of the problem: width of the surf zone, water wave wavelength, etc. is intriguing. The aim of the present contribution is to gain insight into those physical reasons and the dependence of Lm on beach profile and water wave properties. The essence of sandwave behaviour can be captured with the simple one-line shoreline modelling concept by looking at the alongshore position of the maximum in total transport rate Q, which is here investigated with both the linearized model of Falqués and Calvete (2005) and the nonlinear model of van den Berg et al. (2011) . It is found that the position of that maximum is largely controlled by the alongshore distribution of wave energy associated to the sand wave, mainly affected in turn by : A) refractive wave energy spreading and B) refractive energy focusing by the crest. Furthermore, for large L the growthrate decreases to 0 since the gradients in wave energy and hence the gradients in Q decrease. As a result, there is a minimum wavelength, Lc, for growth and an optimum wavelength Lm > Lcof maximum growth. Experiments with different bathymetric profiles and different wave conditions are made to investigate the sensitivity of Lm . It is found that Lm scales with ?0/? where ?0 is the water wave wavelength in deep water and ? the beach slope.

Falqués, A.; van den Berg, N.; Ribas, F.; Caballeria, M.; Calvete, D.

2012-04-01

342

The Jocotán Ophiolite: A new ophiolite along the Jocotán fault, eastern Guatemala  

NASA Astrophysics Data System (ADS)

The North American - Caribbean plate boundary traverses central Guatemala and northern Honduras, dispersed along three left lateral faults systems, which from north to south are the Chixoy-Polochic, the Motagua, and the Jocotán-Camelecón faults, with the Motagua as the present active strand. The Motagua Suture Zone (MSZ), which encompasses this area, consists of multiple paleo-convergent boundaries. It includes slices of ultramafic-mafic complexes including both antigorite (Atg) serpentinite mélanges containing high-pressure / low-temperature (HP/LT) blocks, and lizardite-chrysotile (Lzd-Ctl) serpentinites with associated pillow lavas, radiolarian chert, and marine sediments, typically labeled as ophiolites. Guatemala Suture Zone would be a preferable term to MSZ because the area extends over all three faults, not just the Motagua. The MSZ includes the Sierra de Santa Cruz ophiolite north of the east end of the Polochic fault, the Baja Verapaz ultramafic complex (considered an ophiolite in most of the literature) lies just south of the western portion of the Polochic fault and a series of Atg-serpentinite-dominant mélanges (with HP/LT blocks) that decorate both sides of the Motagua fault. In addition, there is the El Tambor Formation, south of the Motagua fault (but west of the known limit of the Jocotán fault), which contains mafic & sedimentary units and has been called an ophiolite. However, no mafic-ultramafic bodies appear on maps that cover the Jocotán fault in eastern Guatemala. Geologic mapping by one of the co-authors located a small suite of ultramafic rocks sandwiched between the Jocotán and Camotán faults in eastern Guatemala, a short distance from the town of Camotán. Outcrops exposed for 3 km along a road and in a small river consist of sheared Lzd-Ctl serpentinite, metagabbro, overturned altered pillow lavas, listwaenite and rodingite dikes, cherts and pelagic metasediments. These units represent fault slivers subparallel to the steeply dipping local faults sandwiched between mostly phyllites, schists, limestones and metabasites. The latter are similar to the Las Ovejas Complex and/or the San Diego Phyllite which bound the El Tambor Formation and mélanges further west. The newly observed lithologic package, although small in areal extent, has clear affinities with an ophiolite. No HP/LT metamorphic blocks, or even true amphibolites were observed, so consistent with the presence of Lzd-Ctl in the serpentinite, the unit is not a subduction related mélange. The potential relationship with the El Tambor Formation to the west requires further analysis and comparison.

Harlow, G. E.; Flores-Reyes, K.; Sisson, V. B.; Nelson, C.; Cacao, A.

2011-12-01

343

Will Titan lose its veil?  

NASA Astrophysics Data System (ADS)

Methane CH4 is the only highly reactive and short-lived background component in Titan's atmosphere, so its overall reserve predetermines both features and duration of atmospheric chemical activity. Titan's global chemical activity is considered in terms of methane cycle. One cycle is defined as a period T0=7.0.1014s of complete photochemical destruction of methane's observable atmospheric content CH04 = 2.33.1017 kg. Cycle duration T0, number of the past NP =200±20, future NF =500±50 and total Nmax=NP+NF =700±70 cycles are the main quantitative indices of the global chemical activity [2]. The fact that the period T0 is much less than Titan's lifetime TT =1.42*1017s implies that the current content CH04 is continuously replenishing by methane global circulation. There are two sources of this replenishment, i.e. the outgassing of primordial methane reserve trapped in Titan's interior as the clathrate, and the (sub)ground liquidphase reduction of non-saturated final products of the atmospheric photochemical process. Internal reserve provides the dominant portion (>95%) of general recycling, while reducing reconversion is the minor constituent of the global balance. Yet, there is the problem of the availability of the off-the-shelf trapped methane. Overall admissible stock of the trapped methane depends on its internal allocation and falls in the range (CH4)max1,2=(15.3÷33.3).1020 kg, while continuous atmospheric activity during the whole Titan's life TSun 5.0.1017s needs only (CH4)crit=(CH04 ).Nmax = .(CH4)max 1.65.1020 kg. In turn, this bulk (CH4)crit depends on the clathrate cage-filling efficiency (molecular packing index) {kg CH4/kg clathrate} and can be provided if equals respectively to [1] crit1= (TSun/T0).[(CH4)0/[(CH4)max1] = 5.45.10-3 crit2= (TSun/T0).[(CH4)0/[(CH4)max2] = 2.51.10-3 Thus, the interrelation of overall trapped stock (CH4)max and crucial -values assigns the critical value (CH4)crit that in turn predetermines the very fate of Titan's veil. If the real stock (CH4)real (CH4)crit=1.65.1020 kg, than Titan will lose its veil inevitably (scenario of the "mosaic history"), otherwise (CH4)real (CH4)crit the veil survives down to Titan's dying day ("continuous history"). References [1] H. B. Niemann and 17-co-authors, Nature, 438, 779, (2005). [2] V. Dimitrov, Prog. React. Kin. Mech. 30, N4, 227, (2006).

Dimitrov, V.

2007-08-01

344

Citations Prize 2009 Citations Prize 2009  

NASA Astrophysics Data System (ADS)

Physics in Medicine & Biology (PMB) awards its 'Citations Prize' to the authors of the original research paper that has received the most citations in the preceding five years (according to the Institute for Scientific Information (ISI)). The lead author of the winning paper is presented with the Rotblat Medal (named in honour of Professor Sir Joseph Rotblat who was the second—and longest serving—Editor of PMB, from 1961-1972). The winning co-authors each receive a certificate. Photograph of the 2009 Citations Prize winners Some of the winning authors with their certificates, and Christian Morel with the Rotblat Medal, at the award ceremony in Orsay, near Paris. From left to right are Corinne Groiselle, Lydia Maigne, David Brasse, Irène Buvat, Dimitris Visvikis, Giovanni Santin, Uwe Pietrzyk, Pierre-François Honore, Christian Morel, Sébastien Jan and Arion Chatziioannou. The winner of the 2009 Citations Prize for the paper which has received the most citations in the previous 5 years (2004-2008) is GATE: a simulation toolkit for PET and SPECT Authors: S Jan, G Santin, D Strul, S Staelens, K Assié, D Autret, S Avner, R Barbier, M Bardiès, P M Bloomfield, D Brasse, V Breton, P Bruyndonckx, I Buvat, A F Chatziioannou, Y Choi, Y H Chung, C Comtat, D Donnarieix, L Ferrer, S J Glick, C J Groiselle, D Guez, P-F Honore, S Kerhoas-Cavata, A S Kirov, V Kohli, M Koole, M Krieguer, D J van der Laan, F Lamare, G Largeron, C Lartizien, D Lazaro, M C Maas, L Maigne, F Mayet, F Melot, C Merheb, E Pennacchio, J Perez, U Pietrzyk, F R Rannou, M Rey, D R Schaart, C R Schmidtlein, L~Simon, T Y Song, J-M Vieira, D Visvikis, R Van de Walle, E Wieörs and C Morel Reference: S Jan et al 2004 Phys. Med. Biol. 49 4543-61 Since its publication in 2004 this article has received over 200 citations. This extremely high figure is a testament to the great influence and usefulness of the work to the nuclear medicine community. More discussion of the winning paper can be found on medicalphysicsweb. Steve Webb Editor-in-Chief Simon Harris Publisher

Webb, Steve; Harris, Simon

2009-12-01

345

Dynamics and imaging of subduction  

NASA Astrophysics Data System (ADS)

Convergent plate boundaries evolve through the dynamic interaction between subducting oceanic lithosphere, overriding lithosphere, and adjacent flow of the convective mantle. These lithospheric plates contain remarkable heterogeneity in thickness, strength, and observable seismic character. I investigate the role of variable thickness of continental lithosphere with respect to mantle flow dynamics and develop a relationship of this subduction configuration with the construction of the Andes Mountains. By inclusion of this geodynamic model into the Andean Orogeny, numerous irreconcilable observations in the Eocene and Oligocene can be related with a comprehensive tectonic model. Lithospheric heterogeneity can be imaged with the inversion of seismic travel time data. I develop an analysis of a potential source of non-unique modeling of seismic velocity structure and then develop a case study of a currently subducting oceanic lithosphere using an iterative ray tracing approach. First, I consider the impact of the assumption of isotropic wave propagation implicit in a common methodology of data inversion. First-order structure is shown to be well resolved, but higher-order structure can be significantly different in regions of observed high-amplitude or null SKS splitting observations. The southern edge of the Juan de Fuca plate is imaged by traditional methods and an iterative ray tracing approach. The inclusion of ray tracing allows modeling of a more realistic velocity model by minimizing the error in source to receiver sensitivity. Compared to the standard imaging procedure, the resolved structure with this updated method contains smaller, more confined anomalies that represent the subducted oceanic lithosphere. Velocity perturbation amplitudes generally are decreased for slow structure and increase for fast structures. These changes in velocity structure provide an explanation for the decreased root mean square residual of the data that remain after inversion. I find that the high amplitude fast velocity of the Juan de Fuca is a robust feature and the currently subducting slab does not penetrate the mantle transition zone. I attribute the locus of very fast Juan de Fuca sub-continental lithosphere to be related to deformation of the plate prior to and during subduction. This dissertation includes previously published co-authored material.

O'Driscoll, Leland

346

Effects of noise on teleseismic T* estimation and attenuation tomography of the Yellowstone region  

NASA Astrophysics Data System (ADS)

Studies on seismic attenuation are an important complement to those on seismic velocity, especially when interpreting results in terms of temperature. But estimation of attenuation (t*) is more computationally involved and prone to contamination by noise, especially signal-generated noise. We have examined the effects of various forms of synthetic noise on t* estimation using time and frequency domain methods with varying window lengths and data frames of reference. We find that for S-waves, error due to noise can be reduced by rotating the data into the estimated polarization direction of the signal, but unless the exact nature of the noise is known, no method or window size is clearly preferable. We recommend the use of multiple estimation methods including a careful assessment of the uncertainty associated with each estimate, which is used as a weight during inversion for 1/Q. Our synthetic tests demonstrate that the misfit between actual and estimate-predicted traces or spectra correlates with t* error, and a similar relationship is suggested for real data. Applying this approach to data from the Yellowstone Intermountain Seismic Array, we employ two important constraints during inversion. First, we scale the misfit values so that the resulting weights are comparable in magnitude to the squares of the eventual data residuals. Second, we smooth the model so that the maximum attenuation (1/Q) does not exceed a value which would totally explain the observed velocity anomaly. The tomographic models from all the estimation methods are similar, but in the vicinity of the Yellowstone mantle plume, S-wave models show greater attenuation than do P-wave models. We attribute this difference to greater focusing by the plume of S-waves. All models show relatively high attenuation for the plume at depth, but above 250 km attenuation in the plume drops rapidly to values less than those of the surrounding mantle. We attribute this drop to the onset of partial melting, which dehydrates the olivine crystals, suppressing dislocation mobility and thereby attenuation. These attenuation models suggest excess plume temperatures at depth which are too low to support a plume origin in the lower mantle. This dissertation includes unpublished co-authored material.

Adams, David C.

347

Impact factors of forensic science and toxicology journals: what do the numbers really mean?  

PubMed

This article presents review and opinion about the use and abuse of journal impact factors for judging the importance and prestige of scientific journals in the field of forensic science and toxicology. The application of impact factors for evaluating the published work of individual scientists is also discussed. The impact factor of a particular journal is calculated by dividing the number of current year citations to a journal's articles that were published in the previous 2 years by the total number of citable items (articles and reviews) published in the same 2-year period. Journal impact factors differ from discipline to discipline and range from 0 for a journal whose articles are not cited in the previous 2 years to 46 for a journal where the average recent article is cited 46 times per year. The impact factor reflects the citation rate of the average article in a journal and not a specific article. Many parameters influence the citation rate of a particular journal's articles and, therefore, its impact factor. These include the visibility and size of the circulation of the journal including availability of electronic formats and options for on-line search and retrieval. Other things to consider are editorial standards especially rapid and effective peer-reviewing and a short time lag between acceptance and appearance in print. The number of self-citations and citation density (the ratio of references to articles) and also the inclusion of many review articles containing hundreds of references to recently published articles will boost the impact factor. Judging the importance of a scientist's work based on the average or median impact factor of the journals used to publish articles is not recommended. Instead an article-by-article citation count should be done, but this involves much more time and effort. Moreover, some weighting factor is necessary to allow for the number of co-authors on each article and the relative positioning of the individual names should also be considered. Authors should submit their research results and manuscripts to journals that are easily available and are read by their peers (the most interested audience) and pay less attention to journal impact factors. To assess the true usefulness of a person's contributions to forensic science and toxicology one needs to look beyond impact factor and citation counts. For example, one might consider whether the articles contained new ideas or innovations that proved useful in routine forensic casework or are widely relied upon in courts of law as proof source. PMID:12742682

Jones, A W

2003-04-23

348

The Los Angeles International Airport as a source of ultrafine particles and other pollutants to nearby communities  

NASA Astrophysics Data System (ADS)

Air monitoring was performed in the vicinity of the Los Angeles International Airport (LAX) during the spring of 2003. The purpose of this monitoring was to determine the extent of airport emissions on downwind ambient air in a mixed use neighborhood that includes residences. A mobile air monitoring platform was developed and deployed to measure ultrafine particle numbers (UFP), size distributions, particle length, black carbon (BC), oxides of nitrogen (NO x), and particle-phase polycyclic aromatic hydrocarbons (PM-PAH). Pollutant levels were low at a coastal site upwind of the airport, with UFP ranging between 580 and 3800 counts cm -3, oxides of nitrogen (NO x) from 4 to 22 ppb, black carbon from 0.2 to 0.6 ?g m -3, and PM-PAH ranged from 18 to 36 ng m -3. Markedly higher UFP counts, with average counts of approximately 50,000 cm -3, were observed at a site 500 m downwind of the airport, which was strongly influenced by aircraft landings and where the community interfaced with airport facilities. Black carbon, PM-PAH, and NO x levels were elevated to a lesser extent at downwind locations. Transient peaks in UFP corresponding to aircraft landings and takeoffs were evident. A maximum UFP count reached 4.8 million particles cm -3 downwind of a runway used by jet aircraft for takeoffs. Particle size distributions differed substantially between upwind and downwind locations. The particle numbers at the upwind site were dominated by particles of approximately 90 nm diameter while downwind sites were dominated by particles peaking at approximately 10-15 nm. Additional data obtained from a study of UFP levels conducted subsequently by a co-author indicates that aircraft-generated UFP persist up to 900 m from an LAX runway [Biswas, S., Fine, P.M., Geller, M.D., Hering, S.V., Sioutas, C., 2005. Performance evaluation of a recently developed water-based condensation particle counter. Aerosol Science and Technology 39, 419-427]. Considered together, these observations suggest that airport operations are associated with elevated levels of UFP much further downwind in the neighboring community than would have been predicted by prior studies of UFP from roadway-traffic.

Westerdahl, Dane; Fruin, Scott A.; Fine, Phillip L.; Sioutas, Constantinos

349

The Ultraviolet Albedo of Ganymede  

NASA Astrophysics Data System (ADS)

A large set of ultraviolet images of Ganymede have been acquired with the Hubble Space Telescope over the last 15 years. These images have been used almost exclusively to study Ganymede’s stunning auroral emissions (Feldman et al. 2000; Eviatar et al. 2001; McGrath et al. 2004; Saur et al. 2011; McGrath et al. 2013), and even the most basic information about Ganymede’s UV albedo has yet to be gleaned from these data. We will present a first-cut analysis of both disk-averaged and spatially-resolved UV albedos of Ganymede, with focus on the spatially-resolved Lyman-alpha albedo, which has never been considered previously for this satellite. Ganymede's visibly bright regions are known to be rich in water ice, while the visibly dark regions seem to be more carbonaceous (Carlson et al., 1996). At Lyman-alpha, these two species should also have very different albedo values. References Carlson, R. and 39 co-authors, Near-infrared spectroscopy and spectral mapping of Jupiter and the Galilean satellites: Results from Galileo’s initial orbit, Science, 274, 385-388, 1996. Eviatar, A., D. F. Strobel, B. C. Wolven, P. D. Feldman, M. A. McGrath, and D. J. Williams, Excitation of the Ganymede ultraviolet aurora, Astrophys. J, 555, 1013-1019, 2001. Feldman, P. D., M. A. McGrath, D. F. Strobel, H. W. Moos, K. D. Retherford, and B. C. Wolven, HST/STIS imaging of ultraviolet aurora on Ganymede, Astrophys. J, 535, 1085-1090, 2000. McGrath M. A., Lellouch E., Strobel D. F., Feldman P. D., Johnson R. E., Satellite Atmospheres, Chapter 19 in Jupiter: The Planet, Satellites and Magnetosphere, ed. F. Bagenal, T. Dowling, W. McKinnon, Cambridge University Press, 2004. McGrath M. A., Jia, Xianzhe; Retherford, Kurt; Feldman, Paul D.; Strobel, Darrell F.; Saur, Joachim, Aurora on Ganymede, J. Geophys. Res., doi: 10.1002/jgra.50122, 2013. Saur, J., S. Duling, S., L. Roth, P. D. Feldman, D. F. Strobel, K. D. Retherford, M. A. McGrath, A. Wennmacher, American Geophysical Union, Fall Meeting 2011, abstract #SM23D-08, 2011.

McGrath, Melissa; Hendrix, A.

2013-10-01

350

Evaluation of qPCR curve analysis methods for reliable biomarker discovery: bias, resolution, precision, and implications.  

PubMed

RNA transcripts such as mRNA or microRNA are frequently used as biomarkers to determine disease state or response to therapy. Reverse transcription (RT) in combination with quantitative PCR (qPCR) has become the method of choice to quantify small amounts of such RNA molecules. In parallel with the democratization of RT-qPCR and its increasing use in biomedical research or biomarker discovery, we witnessed a growth in the number of gene expression data analysis methods. Most of these methods are based on the principle that the position of the amplification curve with respect to the cycle-axis is a measure for the initial target quantity: the later the curve, the lower the target quantity. However, most methods differ in the mathematical algorithms used to determine this position, as well as in the way the efficiency of the PCR reaction (the fold increase of product per cycle) is determined and applied in the calculations. Moreover, there is dispute about whether the PCR efficiency is constant or continuously decreasing. Together this has lead to the development of different methods to analyze amplification curves. In published comparisons of these methods, available algorithms were typically applied in a restricted or outdated way, which does not do them justice. Therefore, we aimed at development of a framework for robust and unbiased assessment of curve analysis performance whereby various publicly available curve analysis methods were thoroughly compared using a previously published large clinical data set (Vermeulen et al., 2009) [11]. The original developers of these methods applied their algorithms and are co-author on this study. We assessed the curve analysis methods' impact on transcriptional biomarker identification in terms of expression level, statistical significance, and patient-classification accuracy. The concentration series per gene, together with data sets from unpublished technical performance experiments, were analyzed in order to assess the algorithms' precision, bias, and resolution. While large differences exist between methods when considering the technical performance experiments, most methods perform relatively well on the biomarker data. The data and the analysis results per method are made available to serve as benchmark for further development and evaluation of qPCR curve analysis methods (http://qPCRDataMethods.hfrc.nl). PMID:22975077

Ruijter, Jan M; Pfaffl, Michael W; Zhao, Sheng; Spiess, Andrej N; Boggy, Gregory; Blom, Jochen; Rutledge, Robert G; Sisti, Davide; Lievens, Antoon; De Preter, Katleen; Derveaux, Stefaan; Hellemans, Jan; Vandesompele, Jo

2012-09-03

351

The First Paleomagnetic Polar Wander Path  

NASA Astrophysics Data System (ADS)

At the end of 1952, having completed my work on the Cambridge astatic magnetometer, I was motivated to embark on a "Preliminary Paleomagnetic Survey of Rocks from the British Isles" by exciting results obtained by two fellow research students:- Jan Hospers' proposal of the axial dipole hypothesis and Ted Irving's discovery of strongly oblique Pre-Cambrian paleomagnetic directions, substantiated by the oblique Triassic directions obtained by John Clegg's group. Geologists advised me to collect from palaeontologically well dated rock formations. But these turned out to be very weakly magnetized and thereafter I concentrated on purple and dark red coloured rock formations. By the end of July 1954 I had compiled a table of nine Period-mean paleomagnetic directions spanning the last 600 Myr. I passed a copy to Keith Runcorn to include in a talk (co-authors Creer and Irving) scheduled for the August 1954 Rome Assembly of IAGA. Meanwhile, background reading took me to Gutenberg's "Internal Constitution of the Earth (1951)" where I came across (Fig 12) paths of the north pole proposed by Kreichgauer (1902) and by Koppen and Wegener (1924). This prompted me to calculate a paleomagnetic polar wander path. I presented this at the Annual Meeting of the British Association for the Advancement of Science held at Oxford on September 8th. An artist's representation of it was published in Time Magazine of September 24th 1954 where the accompanying text records that I stressed that similar work on other continents would be necessary to distinguish whether the continents had drifted independently or whether the sole mechanism had been polar wander. On my return to Cambridge, Maurice Hill informally suggested that I should indicate precision, so for each pole I calculated semi-major and minor axes of the ellipse of confidence corresponding to the radius of confidence of each mean direction. These were shown in my Ph.D. thesis, where also I calculated a paleomagnetic pole for John Graham's North American Silurian Rose Hill Formation and argued tentatively that it's location, somewhat to the east of the British Silurian pole, is qualitatively consistent withWegnerian drift.

Creer, K. M.

2004-12-01

352

Most Powerful Eruption in the Universe Discovered  

NASA Astrophysics Data System (ADS)

Astronomers have found the most powerful eruption seen in the Universe using NASA's Chandra X-ray Observatory. A supermassive black hole generated this eruption by growing at a remarkable rate. This discovery shows the enormous appetite of large black holes, and the profound impact they have on their surroundings. The huge eruption is seen in a Chandra image of the hot, X-ray emitting gas of a galaxy cluster called MS 0735.6+7421. Two vast cavities extend away from the supermassive black hole in the cluster's central galaxy. The eruption - which has lasted for 100 million years and is still going - has generated the energy equivalent to hundreds of millions of gamma-ray bursts. Animation of Eruption from Supermassive Black Hole Animation of Eruption from Supermassive Black Hole This event was caused by gravitational energy release as enormous amounts of matter fell toward a black hole. Most of the matter was swallowed, but some of it was violently ejected before being captured by the black hole. "I was stunned to find that a mass of about 300 million Suns was swallowed," said Brian McNamara of Ohio University in Athens, lead author of the study that appears in the January 6, 2005 issue of Nature. "This is almost as massive as the supermassive black hole that swallowed it." Astronomers are not sure where such large amounts of matter came from. One theory is that gas from the host galaxy catastrophically cooled and was then swallowed by the black hole. Illustration of MS 0735.6+742 Illustration of MS 0735.6+742 The energy released shows that the black hole in MS 0735 has grown very dramatically during this eruption. Previous studies suggest that other large black holes have grown very little in the recent past, and that only smaller black holes are still growing quickly. "This new result is as surprising as it is exciting", said co-author Paul Nulsen of the Harvard-Smithsonian Center of Astrophysics. "This black hole is feasting when it should be fasting." Radio emission within the cavities shows that jets from the black hole erupted to create the cavities. Gas is being pushed away from the black hole at supersonic speeds over a distance of about a million light years. The mass of the displaced gas equals about a trillion Suns, more than the mass of all the stars in the Milky Way. LA Radio & Chandra X-ray Composite of MS 0735.6+7421 VLA Radio & Chandra X-ray Composite of MS 0735.6+7421 The rapid growth of supermassive black holes is usually detected by observing very bright radiation from the centers of galaxies in the optical and X-ray wavebands, or luminous radio jets. In MS 0735 no bright central radiation is found and the radio jets are faint. Therefore, the true nature of MS 0735 is only revealed through X-ray observations of the hot cluster gas. "Until now we had no idea that this black hole was gorging itself", said co-author Michael Wise of the Massachusetts Institute of Technology. "The discovery of this eruption shows that X-ray telescopes are necessary to understand some of the most violent events in the Universe." The astronomers estimated how much energy was needed to create the cavities by calculating the density, temperature and pressure of the hot gas. By making a standard assumption, that 10% of the gravitational energy goes into launching the jets, they estimated how much material the black hole swallowed. Size Comparison of MS 0735.6+7421 & Perseus Cluster Size Comparison of MS 0735.6+7421 & Perseus Cluster Besides generating the cavities, some of the energy from this eruption should keep the hot gas around the black hole from cooling, and some of it may also generate large-scale magnetic fields in the galaxy cluster. Chandra observers have discovered other cavities in galaxy clusters, but this one is easily the largest and the most powerful. For example, the energy content here exceeds that of the Perseus cavities by 250 times, and dwarfs the cavities in M87 by a factor of 10,000. NASA's Marshall Space Flight Center, Huntsville,

2005-01-01

353

Ghost Remains After Black Hole Eruption  

NASA Astrophysics Data System (ADS)

NASA's Chandra X-ray Observatory has found a cosmic "ghost" lurking around a distant supermassive black hole. This is the first detection of such a high-energy apparition, and scientists think it is evidence of a huge eruption produced by the black hole. This discovery presents astronomers with a valuable opportunity to observe phenomena that occurred when the Universe was very young. The X-ray ghost, so-called because a diffuse X-ray source has remained after other radiation from the outburst has died away, is in the Chandra Deep Field-North, one of the deepest X-ray images ever taken. The source, a.k.a. HDF 130, is over 10 billion light years away and existed at a time 3 billion years after the Big Bang, when galaxies and black holes were forming at a high rate. "We'd seen this fuzzy object a few years ago, but didn't realize until now that we were seeing a ghost", said Andy Fabian of the Cambridge University in the United Kingdom. "It's not out there to haunt us, rather it's telling us something - in this case what was happening in this galaxy billions of year ago." Fabian and colleagues think the X-ray glow from HDF 130 is evidence for a powerful outburst from its central black hole in the form of jets of energetic particles traveling at almost the speed of light. When the eruption was ongoing, it produced prodigious amounts of radio and X-radiation, but after several million years, the radio signal faded from view as the electrons radiated away their energy. HDF 130 Chandra X-ray Image of HDF 130 However, less energetic electrons can still produce X-rays by interacting with the pervasive sea of photons remaining from the Big Bang - the cosmic background radiation. Collisions between these electrons and the background photons can impart enough energy to the photons to boost them into the X-ray energy band. This process produces an extended X-ray source that lasts for another 30 million years or so. "This ghost tells us about the black hole's eruption long after it has died," said co-author Scott Chapman, also of Cambridge University. "This means we don't have to catch the black holes in the act to witness the big impact they have." This is the first X-ray ghost ever seen after the demise of radio-bright jets. Astronomers have observed extensive X-ray emission with a similar origin, but only from galaxies with radio emission on large scales, signifying continued eruptions. In HDF 130, only a point source is detected in radio images, coinciding with the massive elliptical galaxy seen in its optical image. This radio source indicates the presence of a growing supermassive black hole. People Who Read This Also Read... Milky Way's Super-efficient Particle Accelerators Caught in The Act NASA Joins "Around the World in 80 Telescopes" Celebrate the International Year of Astronomy Galaxies Coming of Age in Cosmic Blobs "This result hints that the X-ray sky should be littered with such ghosts," said co-author Caitlin Casey, also of Cambridge, "especially if black hole eruptions are as common as we think they are in the early Universe." The power contained in the black hole eruption was likely to be considerable, equivalent to about a billion supernovas. The energy is dumped into the surroundings and transports and heats the gas. "Even after the ghost disappears, most of the energy from the black hole's eruption remains", said Fabian. "Because they're so powerful, these eruptions can have profound effects lasting for billions of years." The details of Chandra's data of HDF 130 helped secure its true nature. For example, in X-rays, HDF 130 has a cigar-like shape that extends for some 2.2 million light years. The linear shape of the X-ray source is consistent with the shape of radio jets and not with that of a galaxy cluster, which is expected to be circular. The energy distribution of the X-rays is also consistent with the interpretation of an X-ray ghost. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandr

2009-05-01

354

A Molecular Thermometer for the Distant Universe  

NASA Astrophysics Data System (ADS)

Astronomers have made use of ESO's Very Large Telescope to detect for the first time in the ultraviolet the carbon monoxide molecule in a galaxy located almost 11 billion light-years away, a feat that had remained elusive for 25 years. This detection allows them to obtain the most precise measurement of the cosmic temperature at such a remote epoch. Green Flash at Paranal ESO PR Photo 13a/08 Finding well-hidden galaxies The team of astronomers [1] aimed the UVES spectrograph on ESO's VLT for more than 8 hours at a well-hidden galaxy whose light has taken almost 11 billion years to reach us, that is about 80% of the age of the Universe. The only way this galaxy can be seen is through the imprint its interstellar gas leaves on the spectrum of an even more remote quasar [2]. "Quasars are here only used as a beacon in the very distant Universe. Interstellar clouds of gas in galaxies, located between the quasars and us on the same line of sight, absorb parts of the light emitted by the quasars. The resulting spectrum consequently presents dark 'valleys' that can be attributed to well-known elements and possibly molecules," explains Raghunathan Srianand (Pune, India), who led the team making the observations. Thanks to the power of the VLT and a very careful selection of the target - the target was selected among about ten thousands quasars - the team was able to discover the presence of normal and deuterated molecular hydrogen (H2, HD) and carbon monoxide (CO) molecules in the interstellar medium of this remote galaxy. "This is the first time that these three molecules have been detected in absorption in front of a quasar, a detection that has remained elusive for more than a quarter century," says Cédric Ledoux (ESO), member of the team. The same team had already broken the record for the most distant detection of molecular hydrogen in a galaxy that we see as it was when the Universe was less than 1.5 billion years old (see ESO 16/06). The interstellar gas is the reservoir from which stars form and, as such, is an important component of galaxies. Furthermore, because the formation and the state of molecules are very sensitive to the physical conditions of the gas, which in turn depend on the rate at which stars are formed, the detailed study of the chemistry of the interstellar medium is an important tool to understand how galaxies form. Based on their observations, the astronomers showed that the physical conditions prevailing in the interstellar gas in this remote galaxy are similar to what is seen in our Galaxy, the Milky Way. Blue Flash at Paranal ESO PR Photo 13b/08 Discovering the CO molecule in a remote galaxy But most importantly, the team was able to measure with the best ever precision the temperature of the cosmic background radiation in the remote Universe [3]. "Unlike other methods, measuring the temperature of the cosmic background using the CO molecule involves very few assumptions," declares co-author Pasquier Noterdaeme. If the Universe was formed in a 'Big Bang', as most astrophysicists infer, the glow of this primeval fireball should have been warmer in the past. This is exactly what is found by the new measurements. "Given the current measured temperature of 2.725 K, one would expect that the temperature 11 billion years ago was about 9.3 K," says co-author Patrick Petitjean. "Our unique set of VLT observations allows us to deduce a temperature of 9.15 K, plus or minus 0.7 K, in excellent agreement with the theory." "We believe our analysis pioneers interstellar chemistry studies at high redshift and demonstrates that it is possible, together with the detection of other molecules such as HD or CH, to use interstellar chemistry to tackle important cosmological issues," adds Srianand. The results described here have been presented in a Letter to the Editor in Astronomy and Astrophysics ("First detection of CO in a high-redshift damped Lyman-alpha system", by R. Srianand et al.).

2008-05-01

355

Watching a 'New Star' Make the Universe Dusty  

NASA Astrophysics Data System (ADS)

Using ESO's Very Large Telescope Interferometer, and its remarkable acuity, astronomers were able for the first time to witness the appearance of a shell of dusty gas around a star that had just erupted, and follow its evolution for more than 100 days. This provides the astronomers with a new way to estimate the distance of this object and obtain invaluable information on the operating mode of stellar vampires, dense stars that suck material from a companion. Uncovering the disc ESO PR Photo 22/08 Dust shells around a nova Although novae were first thought to be new stars appearing in the sky, hence their Latin name, they are now understood as signaling the brightening of a small, dense star. Novae occur in double star systems comprising a white dwarf - the end product of a solar-like star - and, generally, a low-mass normal star - a red dwarf. The two stars are so close together that the red dwarf cannot hold itself together and loses mass to its companion. Occasionally, the shell of matter that has fallen onto the ingesting star becomes unstable, leading to a thermonuclear explosion which makes the system brighter. Nova Scorpii 2007a (or V1280 Scorpii), was discovered by Japanese amateur astronomers on 4 February 2007 towards the constellation Scorpius ("the Scorpion"). For a few days, it became brighter and brighter, reaching its maximum on 17 February, to become one of the brightest novae of the last 35 years. At that time, it was easily visible with the unaided eye. Eleven days after reaching its maximum, astronomers witnessed the formation of dust around the object. Dust was present for more than 200 days, as the nova only slowly emerged from the smoke between October and November 2007. During these 200 days, the erupting source was screened out efficiently, becoming more than 10,000 times dimmer in the visual. An unprecedented high spatial resolution monitoring of the dust formation event was carried out with the Very Large Telescope Interferometer (VLTI), extending over more than 5 months following the discovery. The astronomers first used the AMBER near-infrared instrument, then, as the nova continued to produce dust at a high rate, they moved to using the MIDI mid-infrared instrument, that is more sensitive to the radiation of the hot dust. Similarly, as the nova became fainter, the astronomers switched from the 1.8-m Auxiliary Telescopes to their larger brethren, the 8.2-m Unit Telescopes. With the interferometry mode, the resolution obtained is equivalent to using a telescope with a size between 35 and 71 metres (the distance between the 2 telescopes used). The first observations, secured 23 days after the discovery, showed that the source was very compact, less than 1 thousandth of an arcsecond (1 milli-arcsecond or mas), which is a size comparable to viewing one grain of sand from about 100 kilometres away. A few days later, after the detection of the major dust formation event, the source measured 13 mas. "It is most likely that the latter size corresponds to the diameter of the dust shell in expansion, while the size previously measured was an upper limit of the erupting source," explains lead author Olivier Chesneau. Over the following months the dusty shell expanded regularly, at a rate close to 2 million km/h. "This is the first time that the dust shell of a nova is spatially resolved and its evolution traced starting from the onset of its formation up to the point that it becomes too diluted to be seen", says co-author Dipankar Banerjee, from India. The measurement of the angular expansion rate, together with the knowledge of the expansion velocity, enables the astronomer to derive the distance of the object, in this case about 5500 light-years. "This is a new and promising technique for providing distances of close novae. This was made possible because the state of the art facility of the VLTI, both in terms of infrastructure and management of the observations, allows one to schedule such observations," says co-author Markus Wittkowski from ESO. Moreover, the q

2008-07-01

356

All In The Family: Chandra Finds Evidence That Massive Stars Are More Like The Sun Than Previously Believed  

NASA Astrophysics Data System (ADS)

NASA's Chandra X-ray Observatory has found evidence that massive stars may be much more like the Sun than previously thought. Astronomers determined that magnetic loop structures, similar to those on the Sun, may exist on the surface of so-called O-type stars, some of the most luminous stars in the universe. "This result is quite surprising," says Wayne Waldron of Emergent Information Technologies, Inc., and co-author of a paper submitted to the Astrophysical Journal Letters. "This bucks conventional wisdom to find that these stars may really resemble our Sun." Zeta Orionis Press Image and Caption Using Chandra's High-Energy Transmission Grating Spectrometer (HETGS) in conjunction with a CCD X-ray camera, astronomers observed the star Zeta Orionis (one of the three belt stars in the constellation of Orion) and found strong X-ray line emission from ions of iron, oxygen, and other elements. The high-resolution X-ray spectrum enabled astronomers to determine that the X-ray emitting gas has a density 1000 times larger than predicted by current models, an amount comparable to the atmospheric density just above the surface of the star. For many years, solar astronomers have derived densities of X-ray producing plasmas on the Sun using emission lines of ions like helium, those with just two bound electrons remaining. Chandra allows this approach to be used for other stars and it has detected X-rays from silicon ions that have been stripped of 12 of their usual complement of 14 electrons. This ion is an especially useful diagnostic of plasma densities in the extremely ultraviolet-bright environment surrounding O-stars. Following the discovery of X-ray emission from O-class stars some 20 years ago, astronomers assumed that the X-rays were created in a hot corona near the star, similar to the Sun's corona. Those models were then abandoned in favor of the currently preferred explanation: the X-ray radiation is created by energetic shocks in the stellar winds (steady streams of matter ejected from many stars, including the Sun). However, these new Chandra spectral data reveal a much higher density for the hot, X-ray producing gas than predicted if such shock models were correct. The Chandra observations also contradict current understanding since the team of researchers found no evidence of expansion in the emission lines - a fundamental prediction for shock models. According to Waldron and co-author Joseph Cassinelli of the University of Wisconsin, Madison, their observations are best explained if the high density X-ray emission comes from confined structures of very hot plasma, similar to the magnetic loops found on the Sun. [For recent results on the Sun's magnetic loops, see the NASA HQ press release, "Fountains of Fire Illuminate Solar Mystery," issued September 26, 2000.] A challenge for scientists will be to explain how these magnetic loops are generated and maintained. Although O-type stars have inner convection zones in their core, they are believed to lack outer convection zones, an ingredient scientists considered necessary to create such hot and energetic plasmas confined in magnetic loops. Convection zones are regions where most of the energy is transported by fluid motions from hotter regions to cooler ones. Without these zones being located near the stellar surface, astronomers are currently unable to explain how such high-densities knots of X-rays could exist. O-type stars, often found in groups of similar stars known as "OB associations," are massive objects, which are typically 10 or more times the Sun's mass. These stars are known to have relatively short life spans, since they burn their nuclear fuel much faster than smaller stars. The star Waldron and Cassinelli observed with Chandra, Zeta Orionis, is classified as an O "supergiant," which is 30 times larger, 30 times more massive, and radiates one hundred thousand times more energy than the Sun. The binary system of Zeta Orionis can be seen with the unaided eye from both Hemispheres for much of the year. Viewing

2000-10-01

357

Obituary: Alan D. Fiala (1942-2010)  

NASA Astrophysics Data System (ADS)

Dr. Alan Dale Fiala, astronomer and expert on solar eclipses, died on May 26, 2010 in Arlington, Virginia, of respiratory failure after a brief illness. He was 67. Fiala had been a staff astronomer at the U.S. Naval Observatory in Washington, D.C., for his entire professional career, where he rose from a position as a summer intern to become the Chief of the Nautical Almanac Office, responsible for annual publications for astronomy and navigation that are used the world over. He retired from the observatory in 2000. Although a childhood case of polio affected his mobility for the rest of his life, he seldom let his physical constraints limit his activities, which were many and varied. Alan Fiala was born in Beatrice, Nebraska on November 9, 1942, the middle son of Emil A. ("John") and Lora Marie Fiala. Fiala's father was a postal clerk and Civil Service examiner. Fiala expressed interest in astronomy at a very young age. He contracted polio when he was 9. He graduated from Beatrice High School in 1960 with a straight-A average and went on to study at Carleton College. He received his B.A. summa cum laude after three years, in 1963, with a major in astronomy and minors in physics and mathematics. He was elected to Phi Beta Kappa, Sigma Xi, and Pi Mu Epsilon (mathematics). In 1962, Alan Fiala obtained a job as a summer intern at the Naval Observatory in Washington, working in the Nautical Almanac Office (NAO). He entered the graduate program at Yale University and continued to work summers at the observatory. He received his Ph.D. in 1968, under Gerald Clemence. His dissertation was titled "Determination of the Mass of Jupiter from a Study of the Motion of 57 Mnemosyne." After receiving his doctorate, Fiala became a permanent member of the Naval Observatory staff. Computers were just being introduced there and he participated in the automation of many procedures used to prepare the annual publications of the Nautical Almanac Office. One of his first assignments was to prepare a visual identification chart of the navigational stars to be used for backup navigation on Apollo 8 and several subsequent space missions. In 1973, Alan Fiala was assigned to take over and modernize the prediction of solar and lunar eclipses. He developed software for calculating eclipse phenomena and generating eclipse maps that is still the basis of the computations at the observatory almost four decades later. As one of the world's experts on eclipse calculations, he was the lead author of the chapter on eclipse calculations in the 1992 Explanatory Supplement to the Astronomical Almanac, and was also the co-author of Canon of Lunar Eclipses 1500 B.C-A.D. 3000 with Bao-Lin Liu, the foremost Chinese expert. In 1979, Alan Fiala began a collaborative effort with two other colleagues, supported by NSF and NASA, to observe solar eclipses in order to detect possible long-term variations in the solar diameter. Fiala pioneered the use of portable video cameras to record the disappearance and reappearance of the Sun from behind the Moon's limb during an eclipse, as viewed from the edges of the central eclipse paths. He was the leader or co-organizer of expeditions to ten solar eclipses around the world and was the co-author of several articles on this project. In 1996, Alan Fiala was appointed Chief of the Nautical Almanac Office. The office, which dates from 1849, is responsible for four annual publications that set the international standard for accuracy for positional astronomy and celestial navigation. Fiala made great progress in modernizing and standardizing the production process for the publications. He also began revision of the scientific basis of the books while adding complementary information on the Internet. Fiala was Chief of NAO during its sesquicentennial and, with Steven J. Dick, co-edited the Proceedings of the Nautical Almanac Office Sesquicentennial Symposium. Alan Fiala received numerous awards during his career at the Observatory, including the Captain James Melville Gilliss Award for service. Minor planet 3695 Fia

Kaplan, George

2011-12-01

358

Obituary: Ronald Eugene Pitts, 1949-2008  

NASA Astrophysics Data System (ADS)

Ronald Pitts, systems engineer in the Commanding Branch of the Space Telescope Science Institute and long-time Computer Sciences Corporation employee, died suddenly of a stroke on 4 May 2008 at his home in Laurel, Maryland. He was a dedicated scientist-engineer, husband, father, volunteer, and cherished friend to many. Ron was born on 19 January 1949 in Tucson, Arizona, and was raised, along with his sister Suzanne, on his parents' turkey farm outside Tucson. He picked up practical knowledge from his father, Vernon, and became a competent amateur electrician and plumber, skills he kept honed and used throughout his life. His mother, Ruth (Stephens), was a nurse and taught him compassion and patience and encouraged his inquisitive mind. Ron attended public schools and enrolled at the University of Arizona, graduating with a B. S. in Astronomy in 1971. Being from a family of modest means, he put himself through school working summers and part-time at a large copper mine south of town. Ron enrolled in the graduate astronomy program at the Ohio State University [OSU] in the fall of 1971 where he was a first-year fellowship student. During his second and third years, he was the Perkins Assistant, taking spectra for the very exacting but appreciative Philip Keenan who once remarked to another faculty member that Ron was the best observer he ever had. Later, in 1980, Ron was co-author with Keenan on "Revised MK Spectral Types for G, K, and M stars" and again in 1985 in a study of supergiants in open clusters. He met his future wife, Patricia Moore, also a graduate student in the department, and they were wed in 1973. Ron was also partially supported during his early OSU years by an NSF grant to Robert Wing, writing parts of Wing's photometric reduction code and observing on the program at Kitt Peak and Flagstaff in the summer of 1974. Wing remembers him as being very competent and pleasant to work with. Ron's thesis topic was "Oscillator Strengths for Neutral Iron and Silicon" under the direction of Gerald Newsom, and he was awarded the PhD in 1979. Newson recalls his facility with instrumentation, designing new circuitry to solve problems with the shock tube and ferreting out sources of systematic errors, and that it was enjoyable to work with him. In the fall of 1979, Ron went to Ball State University where he taught undergraduate astronomy classes for four years. In the summer of 1983, Ron left academia for the position of IUE Resident Astronomer with Computer Sciences Corporation [CSC] at the Goddard Space Flight Center where he joined a small contingent of other Ohio State graduates. For the next eleven years, he supported guest observers, implemented work-arounds as the IUE gyroscopes failed, improved calibrations, and had several proposals accepted to obtain spectra of spectrophotometric standards and to observe upper-main-sequence stars in the Pleiades, a Per, and NGC 2244, work that he did with Nancy Remage Evans. Ron worked diligently on the software to combine the best IUE calibration with ground-based data of the hot cluster stars and to fit the temperature and gravity. He also became interested in advanced technology for lunar remote telescopes and co-authored several studies with Peter Chen and others. After their children were of school age, Ron's wife Pat also worked for CSC/IUE for part of this period. In October 1994, Ron transferred to the Space Telescope Science Institute in Baltimore, Maryland, where he joined the science instrument commanding group under the direction of Vicki Balzano. His first task was helping to write the commanding software controlling the Space Telescope Imaging Spectrograph to be installed in HST in February 1997, and he became the in-house expert on the workings of this complex instrument, in particular on the details of the time-tag mode. In time, he became familiar with all the on-board instruments and oversaw the approval of the instrument commanding before the weekly HST command loads were distributed to the Goddard Space Flight Center for uploading to the te

MacConnell, D. Jack

2009-01-01

359

What if the power-law model did not apply for the prediction of very large rockfall events?  

NASA Astrophysics Data System (ADS)

Extreme events are of primary importance for risk management in a variety of natural phenomena, and more particularly for landslides and rockfalls, because they might be associated with huge losses. Numerous research works have addressed this problem based on the same paradigm: if events exhibit the same statistical properties across a broad range of sizes, the probability of extreme events can be evaluated by extrapolating the frequency-size distribution. Considering landslides' areas or rockfalls' volumes, the frequency distribution has been found to be heavy-tailed and the well-known power law distribution has been proposed to model it. Yet, the vision of very large extreme event (catastrophic) frequency being an extrapolation of the power laws fitted on small and intermediate events has been challenged in various contexts, in particular by Sornette and co-authors, who proposed viewing such catastrophic events as "outliers" from the power-law model, i.e. they deviate by an abnormal large distance from the extrapolated prediction. In this study, we address such an issue considering a rockfall inventory, containing >8500 events spanning 8 orders of magnitudes of volume and collated from 2.5 years of high-accuracy repeated terrestrial laser scanning (TLS) surveys on a coastal chalk cliff in Normandy (France). This inventory contains a particularly large event of 70,949 m3 which occurred some time between February 1 and 7 April 2008. It is the second largest cliff failure reported in Normandy, and is larger than those collated in historical cliff failure inventories across various geological and geomorphological coastal settings. Is this event an outlier of the power-law volume-frequency distribution ? And if so, why? This largest event recorded appears to stand out of the rest of the sample. We use it to revisit the techniques to fit power-law distribution with robust techniques (robust weighted maximum likelihood estimator), rarely used in rockfall studies, and presenting the appealing feature to be less sensitive to the presence of outliers by assigning a weight within [0 ; 1] to each observation according to its representativeness. Through a bootstrap-based technique, we demonstrate the statistical significance (with p-value <1 %, i.e. not arising by chance) of the low weight assigned to the largest rockfall event i.e. of the deviation from the fractal set of the smaller events. Excluding gross volumetric error on our observation since we used a high-accuracy TLS, we discuss possible mechanisms and their implications for prediction, focusing on two main issues: 1. normal faults bounding the largest rockfall and along which the rupture occurred, which may suggest the hypothesis of a "characteristic" rockfall, i.e. presenting a characteristic scale of the same order of the fault length, as suggested for earthquakes; 2. possible log-periodic signature that decorates the pure power law and linked with the concept of Discrete Scale Invariance. This concept means that scale invariance is kept, but only for specific scales organized in a discrete hierarchy and with some fixed preferred scaling ratio. Such scaling ratio may itself be linked to pre-existing fracture networks.

Rohmer, J.; Dewez, T.

2012-04-01

360

The Medical Geochemistry of Dusts, Soils, and Other Earth Materials  

NASA Astrophysics Data System (ADS)

"Town clenched in suffocating grip of asbestos"USA Today, article on Libby,Montana, February, 2000"Researchers find volcanoes are bad for your health… long after they finish erupting"University of WarwickPress Release, 1999"Toxic soils plague city - arsenic, lead in 5 neighborhoods could imperil 17,000 residents"Denver Post, 2002"Ill winds - dust storms ferry toxic agents between countries and even continents"Science News, 2002A quick scan of newspapers, television, science magazines, or the internet on any given day has a fairly high likelihood of encountering a story (usually accompanied by a creative headline such as those above) regarding human health concerns linked to dusts, soils, or other earth materials. Many such concerns have been recognized and studied for decades, but new concerns arise regularly.Earth scientists have played significant roles in helping the medical community understand some important links between earth materials and human health, such as the role of asbestos mineralogy in disease (Skinner et al., 1988; Ross, 1999; Holland and Smith, 2001), and the role of dusts generated by the 1994 Northridge, California, earthquake in an outbreak of Valley Fever ( Jibson et al., 1998; Schneider et al., 1997).Earth science activities tied to health issues are growing (Skinner and Berger, 2003), and are commonly classified under the emerging discipline of medical geology (Finkelman et al., 2001; Selinus and Frank, 2000; Selinus, in press).Medical geochemistry (also referred to as environmental geochemistry and health: Smith and Huyck (1999), Appleton et al. (1996)) can be considered as a diverse subdiscipline of medical geology that deals with human and animal health in the context of the Earth's geochemical cycle ( Figure 1). Many medical geochemistry studies have focused on how chemical elements in rocks, soils, and sediments are transmitted via water or vegetation into the food chain, and how regional geochemical variations can result in disease clusters either through dietary deficiency of essential elements or dietary excess of toxic elements. (28K)Figure 1. Potential human exposure routes within the earth's geochemical cycle can come from a wide variety of both natural and anthropogenic sources. This chapter focuses on a somewhat narrower area of medical geochemistry: the study of mechanisms of uptake of earth materials by humans and animals and their reactions to these materials. In order for earth materials to affect health, they must first interact with the body across key interfaces such as the respiratory tract, gastrointestinal tract, skin, and eyes. In some way, all of these interfaces require the earth materials to interact chemically with water-based body fluids such as lung fluids, gastrointestinal fluids, saliva, or blood plasma.The primary goal of this chapter, co-authored by a geochemist and a toxicologist, is to provide both geochemists and scientists from health disciplines with an overview of the potential geochemical mechanisms by which earth materials can influence human health. It is clear that significant opportunities for advancement in this arena will require continued and increased research collaborations between geochemists and their counterparts in the health disciplines.

Plumlee, G. S.; Ziegler, T. L.

2003-12-01

361

The Scientific Conferences Organized During War Time (1992-1995) in Sarajevo  

PubMed Central

Author of this paper spent 1479 days in the siege of Sarajevo, during the period of war time in Bosnia and Herzegovina (B&H). This siege, lasting from 1992 to 1995 (e.g. Dayton Piece agreement was signed in November, 1995) represents the longest siege in the history of the world. Besides usual daily work, as the associate professor of Health education, Medical deontology and Medical informatics for the students of the Faculty of medicine, Faculty of dental medicine, Faculty of Pharmacy and Nursing college of University of Sarajevo, the author organized by himself and contributors, 10 scientific conferences in a sieged Sarajevo. All presented papers at those conferences are published in Proceedings abstract books, as the proof of continuing scientific work, in Sarajevo and other cities in B&H. Additionally, the author continued to publish, in that time, unique PubMed/MedLine indexed journal, - Medical Archives, (i.e. established in 1947) and, in 1993 formed a new journal named - “Acta Informatica Medica” (AIM) , as the Journal of the Bosnian Society of Medical informatics. Bosnian Society of Medical Informatics, thus became the first scientific association from Bosnia and Herzegovina, included in 1994, in the European Federation of Medical Informatics (EFMI) and the International Medical Informatics Assiciation (IMIA) , which was “miracle” from the besieged Sarajevo and war time result of aggression on Bosnia and Herzegovina. It should be noted that the importance of maintaining these academic gatherings, in the circumstances of war, was multifaceted. First of all, thanks to these meetings, the continuity of scientific meetings and activities in the besieged city of Sarajevo was not broken, as well as the continuity of scientific publication, which was crucial for the maintenance of the teaching staff at the university and, finally, in the expansion of the “scientific truth” about what happened in Sarajevo and B&H in these difficult times. All of this was critical to the “survival” of B&H and its people. Some of the published articles, especially in the Medical Archives journal, which even in difficult war conditions did not break the continuity of its publication, and then it was the only scientific journal indexed in B&H, having been consequently cited in the major biomedical data bases in the world. Many scientists abroad have had the opportunity to learn about some of the wonders of Sarajevo “war medicine”, thanks to this journal. Finally, despite the fact that it is another way of expressing its resistance to the aggression on B&H, the organized symposia in the war represented the continuity of the scientific research activities. Bosnia and Herzegovina and Sarajevo under siege, in this way, kept in touch with the civilized world and modern achievements, despite the fact that they were victims of medieval barbarism. In addition, these meetings sent a powerful message to the world about the willingness to register and systematize all the war experiences, especially those related to medicine and medical practice, in terms of what Europe has not known, since the Second World War. Partially, we succeeded in that. The total number of 286 presentations were presented in seven war Conferences, as quantitative and qualitative contribution to the scientific activities, despite the inhuman conditions, in which these articles emerged. These presentations and Conferences testify to the enthusiasm of B&H community and academic institutions that have collaborated with it. Authors and co-authors presented the “war” articles that deserve to be mentioned in the monograph “1479 days of the siege of Sarajevo”. Unfortunately, many of these brave authors are not alive and cannot read this. The task for us remains to remember them by their own good. Old Persian proverb says; “The event which is not recorded is as like it had never happened”. Sapienti sat.

Masic, Izet

2011-01-01

362

PERSPECTIVE: Dust, fertilization and sources  

NASA Astrophysics Data System (ADS)

Aerosols, tiny suspended particles in the atmosphere, play an important role in modifying the Earth's energy balance and are essential for the formation of cloud droplets. Suspended dust particles lifted from the world's arid regions by strong winds contain essential minerals that can be transported great distances and deposited into the ocean or on other continents where productivity is limited by lack of usable minerals [1]. Dust can transport pathogens as well as minerals great distance, contributing to the spread of human and agricultural diseases, and a portion of dust can be attributed to human activity suggesting that dust radiative effects should be included in estimates of anthropogenic climate forcing. The greenish and brownish tints in figure 1 show the wide extent of monthly mean mineral dust transport, as viewed by the MODerate resolution Imaging Spectroradiometer (MODIS) satellite sensor. The monthly mean global aerosol system for February 2006 from the MODIS aboard the Terra satellite Figure 1. The monthly mean global aerosol system for February 2006 from the MODIS aboard the Terra satellite. The brighter the color, the greater the aerosol loading. Red and reddish tints indicate aerosol dominated by small particles created primarily from combustion processes. Green and brownish tints indicate larger particles created from wind-driven processes, usually transported desert dust. Note the bright green band at the southern edge of the Saharan desert, the reddish band it must cross if transported to the southwest and the long brownish transport path as it crosses the Atlantic to South America. Image courtesy of the NASA Earth Observatory (http://earthobservatory.nasa.gov). Even though qualitatively we recognize the extent and importance of dust transport and the role that it plays in fertilizing nutrient-limited regions, there is much that is still unknown. We are just now beginning to quantify the amount of dust that exits one continental region and the fraction that arrives at another continent [2]. At the deposition end of the chain, it is still unclear how the limited minerals in the dust such as iron are released for uptake by organisms either on land or in the ocean. Not all dust deposited into oceans results in a phytoplankton bloom. The process requires a chemical pathway that mobilizes a fraction of the iron into soluble form. Meskhidze et al [3] show that phytoplankton blooms following dust transport from the Gobi desert in Asia into the Pacific ocean result in a phytoplankton bloom only if the dust is accompanied by high initial SO2-to-dust ratios, suggesting that sulfuric acid coatings on the dust particle mobilize the embedded iron in the dust for phytoplankton uptake. Quantifying transport, deposition and nutrient availability are the latter ends of a puzzle that must begin by identifying and quantifying dust emission at the sources. The emission process is complex at the microscale requiring the right conditions for saltation and bombardment, which makes identification and inclusion of sources in global transport models very difficult. The result is that estimates of annual global dust emissions range from 1000 to 3000 Tg per year [4]. Even as global estimates of dust emissions are uncertain, localizing the sources brings even greater uncertainty. It has been recognized for several years that dust sources are not uniformly distributed over the arid regions of the Earth, but are regulated to topographic lows associated with dried lake deposits [5]. Using aerosol information from satellites, a comprehensive map of the world's source regions shows sources localized to specific areas of the Earth's arid regions [6]. Still these maps suggest broad emission sources covering several degrees of latitude and longitude. In the paper by Koren and co-authors [7] appearing in this issue, one particular dust source, the Bodélé depression in Chad, is analyzed in detail. They find that the specific topography of the depression combined with the prevailing wind direction in the winter provides perfect condition

Remer, Lorraine A.

2006-11-01

363

Light quark spectroscopy results from FOCUS and E687  

NASA Astrophysics Data System (ADS)

Using the FOCUS spectrometer (experiments 687 and 831 at Fermilab) we confirm the existence of a diffractively photoproduced enhancement in K+K- at 1750 MeV/c2 with nearly 100 times the statistics of previous experiments. We also observe a narrow dip structure at 1.9 GeV/c2 in a study of diffractive photoproduction of the 3?+3?- final state. Co-authors are P.L. Frabetti (INFN and Bologna), J.M. Link, V.S. Paolone, M. Reyes, P.M. Yager (UC DAVIS); J.C. Anjos, I. Bediaga, C. Göbel, J. Magnin, A. Massafferri, J.M. de Miranda, I.M. Pepe, A.C. dos Reis, F. Sima~o (CPBF, Rio de Janeiro); S. Carrillo, E. Casimiro, H. Mendez, A. Sánchez-Hernández, C. Uribe, F. Vasquez (CINVESTAV, México City); L. Agostino, L. Cinquini, J.P. Cumalat, C. Dallapiccola, J.F. Ginkel, J.E. Ramirez, B. O'Reilly, I. Segoni, E.W. Vaandering (CU Boulder); J.N. Butler, H.W.K. Cheung, G. Chiodini, S. Cihangir, I. Gaines, P.H. Garbincius, L.A. Garren, E. Gottschalk, S.A. Gourlay, D.J. Harding, P.H. Kasper, A.E. Kreymer, R. Kutschke, P. Lebrun, S. Shukla, M. Vittone (Fermilab); R. Baldini-Ferroli, L. Benussi, F.L. Fabbri, A. Zallo (INFN Frascati); C. Cawlfield, R. Culbertson, R. Greene, D.Y. Kim, K.S. Park, A. Rahimi, J. Wiss (UI Champaign); R. Gardner, A. Kryemadhi (Indiana); Y.S. Chung, J.S. Kang, B.R. Ko, J.W. Kwak, K.B. Lee, S.S. Myung (Korea University, Seoul); K. Cho, H. Park (Kyungpook National University, Taegu); G. Alimonti, S. Barberis, A. Cerutti, G. Bellini, M. Boschini, D. Brambilla, B. Caccianiga, A. Calandrino, L. Cinquini, P.D'Angelo, M. DiCorato, P. Dini, L. Edera, S. Erba, M. Giammarchi, P. Inzani, F. Leveraro, S. Malvezzi, D. Menasce, E. Meroni, M. Mezzadri. L. Milazzo, L. Moroni, D. Pedrini, L. Perasso, C. Pontoglio, F. Prelz, M. Rovere, A. Sala, S. Sala, D. Torretta (INFN and Milano); D. Buchholz, D. Claes, B. Gobbi (Nortwestern); J.M. Bishop, N.M. Cason, C.J. Kennedy, G.N. Kim, T.F. Lin, D.L. Puseljic, R.C. Ruchti, W.D. Shephard, J.A. Swiatek, Z.Y. Wu (Notre Dame); T.F. Davenport III (UNC Asheville); V. Arena, G. Boca, G. Bonomi, C. Castoldi, G. Gianini, G. Liguori, M. Merlo, D. Pantea, S.P. Ratti, C. Riccardi, P. Torre, L. Viola, P. Vitulo (INFN and Pavia); H. Hernandez, A.M. Lopez, L. Mendez, A. Mirles, E. Montiel, D. Olaya, J. Quinones, C. Rivera, Y. Zhang (Mayaguez, Puerto Rico); N. Copty, M. Purohit, J.R. Wilson (USC Columbia); K. Cho, T. Handler (UT Knoxville); D. Engh, W.E. Johns, M. Hosack, M.S. Nehring, M. Sales, P.D. Sheldon, K. Stenson, M.S. Webster (Vanderbilt); M. Sheaff (Wisconsin, Madison); Y. Kwon (Yonsei University, Korea).

Bianco, Stefano

2003-04-01

364

Obituary: James N. Kile, 1958-2007  

NASA Astrophysics Data System (ADS)

James N. Kile, of Needham Heights, Massachusetts, died on 17 August 2007, following a brave two-year battle with cancer. One of three children of David R. Kile and Betty Jane Kile, Jim was born in Niagara Falls, New York, on 20 April 1958 and lived in the nearby village of Lewiston before his family settled in Alden, an hour east of Niagara Falls, when Jim was nine. Jim's father worked for American Telephone and Telegraph for 37 years, and his mother was a homemaker. Jim earned his Bachelor's degree in Physics from Rensselaer Polytechnic Institute in 1980, a Master's degree from Northwestern University in 1982, and a Doctorate from Tufts University in 1996 under the direction of Robert Willson. His thesis involved comparison of radio data from the Very Large Array and the Russian RATAN 600 telescope with Yohkoh soft X-ray data, with an emphasis on understanding the relationship between solar noise storms and coronal magnetic fields. While working on his thesis, Jim collaborated with one of us (EWC) at the Air Force Research Laboratory on an investigation of the 154-day periodicity in solar flares. The resulting publication (ApJ 370, 442, 1991) is his most cited work. Jim co-authored four other papers in refereed journals. Jim's professional affiliations included the American Astronomical Society, the American Institute of Aeronautics and Astronautics, the American Geophysical Union, and the Astronomical Society of the Pacific. Jim worked as a contractor in the defense industry from 1982 until the time of his death, settling in the Boston area in the early 1980s. He worked for Calspan Corporation from 1982-1989, the Ultra Corporation from 1989-1994, and the Riverside Research Institute from 1994-2007. He was a highly-respected expert in radar systems, including radar data and systems analysis, systems engineering, and planning support for radar acquisition programs and technology development. The work entailed frequent extended travel to Norway for system testing. During the summer of 1997 Jim was an instructor for introductory physics laboratories at Simmons College, and in 2002 he developed and taught a synthetic aperture radar measurement and signature intelligence course for the Air Force Institute of Technology in Dayton, Ohio, where he was appointed Adjunct Assistant Professor of Physics in the Department of Engineering Physics, a position he held until 2005. On the local level, Jim assisted in astronomy education projects, such as nighttime telescope viewing, in the Needham public schools and stargazing/astronomy courses at several Massachusetts Audubon wildlife sanctuaries. Jim met the love of his life in the mid-1980s, and he and Elaine were married within the year, on 19 October 1985. They shared a passion for birding and a love for nature witnessed up close when hiking, kayaking, snowshoeing, and cross-country skiing. Jim had a wide range of interests. He was an accomplished folk musician, playing the guitar and ukulele. He was a devoted "Trekkie" who could quote every line from early Star Trek episodes and was a life member of the American Radio Relay League [ARRL]. Jim had the warm and open personality characteristic of those raised in the snow-belt. He was always good company. His courage as he was dying, much too soon, was a great source of strength for his family. Jim is survived by his wife Elaine C. (Smith) Kile, his father David R. Kile, his sister Diane Kile and her husband David Galson, his brother David M. Kile and his wife Susan Kile, and four nephews, one niece, and a great niece and nephew. He was predeceased by his mother Betty Jane Kile.

Cliver, Edward W.; Lang, Kenneth R.; Willson, Robert F.

2009-01-01

365

EDITORIAL: Plasmas and plasmons: links in nanosilver Plasmas and plasmons: links in nanosilver  

NASA Astrophysics Data System (ADS)

Silver has long been valued not just for its rarity but also for its broad ranging attractive properties as a conductor, catalyst and antimicrobial agent, among others. In nanoscale structures, silver takes on a number of additional attributes, as properties such as antimicrobial activity show size dependence. In addition plasmonic properties are exhibited, which enhance local electromagnetic fields and can be hugely beneficial in sensing and imaging applications. As a result silver nanoparticles are increasingly in demand. In this issue researchers describe a microplasma-assisted electrochemical synthesis that allows excellent control over the size and spacing of the resulting particles, which are important parameters for optimizing their performance in device applications [1]. Wet chemistry [2] and lithography [3] are common processes for silver nanoparticle synthesis. However, other methods are constantly in development. Biosynthesis approaches have been attracting increasing interest as more environmentally friendly alternatives. Takayuki Kuwabara and colleagues at Xiamen University in China used the sundried biomass of Cinnamomum camphora leaf to reduce silver nitrate [4], demonstrating a cost-efficient alternative to conventional methods which might also be suitable for large-scale production. At Zhejiang Normal University researchers noted that the abasic site (AP site) in the DNA duplex can act as a capping scaffold in the generation of fluorescent silver nanoclusters [5]. In addition the resulting fluorescence of the nanocrystals can be used for detecting DNA single-nucleotide polymorphism. Researchers in Malaysia have also noted the potential sensing applications of nanoparticles of another noble metal for swine DNA [6]. They observed that single-strand DNA was absorbed on gold nanoparticles and led to a colour shift from pinkish-red to grey-purple. The shift was the result of a reduction in the surface plasmon resonance peak at 530 nm and new features appearing in the 620-800 nm regions of the absorption spectra. A number of research groups have investigated the possibility of exploiting the plasmonic properties of silver and gold nanostructures for optoelectronic devices [7-9]. The advantages can be quite substantial. Researchers in Korea successfully used silver nanoparticles to obtain a 38% increase in performance of blue LEDs by using silver nanoparticles embedded in p-GaN [10]. The researchers attribute the improvement to an increase in the spontaneous emission rate through resonance coupling between the excitons in multiple quantum wells and localized surface plasmons in the silver nanoparticles. In their work reported in this issue Kostya Ostrikov and his co-authors bridge the link between microplasma-assisted electrochemical process parameters and the plasmonic response. As they point out, 'This is an important experimental step towards bringing together plasma chemistry and plasmonics' [1]. All-gas-phase plasma approaches have already been demonstrated for the synthesis of nanoparticles of other metals. X D Pi and colleagues from the University of Minnesota demonstrated how one simple gas-phase process could produce stable silicon nanocrystal emitters with tailored size and surface functionalization [11]. Previously silicon nanocrystals had been prone to emission instabilities in air. Now Ostrikov and colleagues at the University of Sydney, CSIRO Materials Science and Engineering in Australia and the Key Laboratory for Laser Plasmas in China have studied microplasma-assisted electrochemical synthesis of Ag nanoparticles for plasmonic applications [1]. The synthesis uses moderate temperatures and atmospheric pressures and does not involve any toxic reducing agents. In addition they demonstrate how it allows control over nanoparticle size and interparticle spacing to optimize performance in device applications. Despite the overlap in plasma physics and the origins of plasmonic phenomena, studies of the relationship between plasma electrochemical synthesis and the plasmonic properties of nanoparticles ha

Demming, Anna

2013-03-01

366

Recruiting and Retaining Geology Majors at CSUSB: Successes and Barriers  

NASA Astrophysics Data System (ADS)

Our efforts to build a strong geology department at CSUSB have focused on two main areas (1) increasing the number of geology majors, and (2) involving our majors more directly in the department through their involvement in scientific research and outreach activities. To increase the number of majors we have undertaken a three pronged approach: (a) by actively working with middle and high school teachers to better prepare them to teach Earth Sciences in their schools, by providing them with the necessary tools to accomplish this, and by developing a new course on Earth Sciences with emphasis on the California Earth Science Standards to be taken by students in the multi-subject credential program; (b) by showing middle school, high school, and college students that geology is interesting and exciting by involving them in geological activities such as field trips, hands on geological exercises, and in directed research projects; and (c) by conducting a public relations campaign to inform both potential students and the general public about activities being undertaken by the department. The latter has been accomplished by the use of a glossy color brochure designed to illustrate what geology is, and what kinds of careers are possible; by flyers sent to approximately 120 local schools outlining opportunities for field trips and for teachers to bring their students to our campus for various activities; by developing an outreach web site; and by various newspaper articles on departmental activities. We are also looking into the use of TV spots on geological subjects to be aired on public access television. Since the start of our efforts two years ago we have seen a positive response by local teachers, and an increase in the number of applications to study geology at CSUSB, including a significant increase in the number of minority applicants. A major barrier to recruitment has been the misconceived idea in local schools that a course in Earth Sciences does not count towards college entrance requirements. To better integrate our students into departmental activities, we have actively involved them in our outreach activities, and are currently strongly advising our majors to undertake directed research under the supervision of a faculty member. We are also discussing making a "research project" part of the graduation requirements. Representative projects involving our undergraduate students include GPS studies in the San Bernardino area, volcanological studies on the island of Dominica, West Indies, hydrological studies of the springs in the San Bernardino Mountains and studies of biostratigraphy and marine invertebrate paleoecology of the Death Valley region, California. Although a number of these projects have already resulted in students being co-authors on papers and abstracts, the extensive GE requirements and the fact that CSUSB is on the quarter system usually does not allow students sufficient time to develop a research project and take it to completion within an academic year.

Smith, A. L.; McGill, S. F.; Fryxell, J. E.; Leatham, W. B.; Melchiorre, E.; Brunkhorst, B.

2003-12-01

367

Decadal Changes in Surface Radiative Fluxes  

NASA Astrophysics Data System (ADS)

Recent evidence suggests that radiative fluxes incident at the Earth surface are not stable over time but undergo significant changes on decadal timescales. This is not only found in the thermal spectral range, where an increase in the downwelling flux is expected with the increasing greenhouse effect, but also in the solar range. Observations suggest that surface solar radiation, after decades of decline ("global dimming"), reversed into a "brightening" since the mid-1980s at widespread locations. This presentation gives an update on recent investigations related to the decadal variations in these fluxes, based on both observational and modeling approaches. Updated observational data, archived at the Global Energy Balance Archive (GEBA) at ETH Zurich, suggest a continuation of surface solar brightening beyond the year 2000 at numerous locations, yet less pronounced and coherent than during the 1990s, with more regions with no clear changes or declines. Current global climate models as used in the IPCC-AR4 report typically do not reproduce the observed decadal variations to their full extent. Modeling attempts to improve this situation are under way at ETH, based on a global climate model which includes a sophisticated interactive treatment of aerosol and cloud microphysics (ECHAM5-HAM). Further the impact of the decadal changes in surface radiative forcings on different aspects of the global climate system and climate change is discussed, such as 20th century day- and nighttime warming, evapotranspiration changes and the varying intensity of the hydrological cycle as well as the terrestrial carbon cycle. Selected related references: Wild, M., and Co-authors, 2005: From dimming to brightening: Decadal changes in solar radiation at the Earth's surface. Science, 308, 847-850 Wild, M., 2007: Decadal changes in surface radiative fluxes and their importance in the context of global climate change, in: Climate Variability and Extremes during the Past 100 years, Advances in Global Change Research, 140, Editors Stefan Brönnimann et al., p. 155-168. Wild, M., Ohmura A., Makowski, K., 2007: Impact of global dimming and brightening on global warming. Geophys. Res. Lett., 34, L04702, doi:10.1029/2006GL028031. Wild, M., Grieser, J. and Schär, C., 2008: Combined surface solar brightening and greenhouse effect support recent intensification of the global land-based hydrological cycle. Geophys. Res. Lett., 35, L17706, doi:10.1029/2008GL034842 Wild, M., 2009: How well do IPCC-AR4/CMIP3 climate models simulate global dimming/brightening and 20th century day- and night-time warming? To appear in J. Geophys. Res. Wild, M., Truessel, B., Ohmura, A., Long, C.N. König-Langlo G., Dutton, E.G., and Tsvetkov, A., 2009: Global Dimming and Brightening: an update beyond 2000. To appear in J. Geophys. Res. Wild, M., 2009: Global dimming and brightening: A review on decadal changes in surface solar radiation. To appear in J. Geophys. Res.

Wild, M.

2009-05-01

368

Global dimming and brightening studies at ETH  

NASA Astrophysics Data System (ADS)

Global dimming and brightening refers to the decadal variations in solar radiation received at the Earth surface. Measurements suggest that surface solar radiation declined at widespread observation sites ("global dimming") between the 1950s and 1980s, and then partially recovered between the 1980s and 2000 ("brightening", Wild et al. 2005). In this presentation, an overview is given over the global dimming/brightening-related work currently underway at ETH Zurich. These include the update of the Global Energy Balance Archive, a database for the worldwide measured surface energy fluxes, with data beyond 2000. Overall, the available data suggest continuation of surface solar brightening beyond the year 2000 at numerous locations, yet less pronounced and coherent than during the 1990s, with more regions with no clear changes or declines (Wild et al. 2009, Wild 2009a). Modelling attempts are under way at ETH to reproduce the observed dimming and brightening with a Global Climate Model. We run a special version of the ECHAM model series, which includes a sophisticated interactive treatment of aerosol and their emission histories (ECHAM5 HAM). This model is therefore particularly suited for the simulation of dimming and brightening. Further the impact of global dimming and brightening on the global climate system is investigated (Wild 2009a). The fade of global dimming in the 1980s had major consequences for climate change, as it enabled the greenhouse effect to become finally visible at its full dimension (Wild et al. 2007). Surface temperature rise accelerated over recent decades when the damping effect of global dimming was no longer present. This is also seen in diurnal temperature ranges which show, after decades of decline, a distinct tendency to level off since the mid 1980s (Wild et al. 2007, Makowski et al. 2008). This suggests that daytime solar dimming did no longer counteract nighttime thermal warming since the 1980s, thereby no longer diminishing the diurnal temperature range. These effects are not adequately reproduced in the current generation of global climate models used in IPCC AR4 and CMIP3 (Wild 2009b). Further, the increase in available surface energy from both increasing downwelling solar and thermal radiation may have been at the origin of the observed acceleration of the hydrological cycle during the 1990s (Wild et al. 2008). Selected related references: Wild, M., and Co-authors 2005: From dimming to brightening: Decadal changes in solar radiation at the Earth's surface. Science, 308, 847-850. Wild, M., Ohmura A., Makowski, K., 2007: Impact of global dimming and brightening on global warming. Geophys. Res. Lett., 34, L04702, doi:10.1029/2006GL028031. Wild, M., Grieser, J. and Schär, C., 2008: Combined surface solar brightening and greenhouse effect support recent intensification of the global land-based hydrological cycle. Geophys. Res. Lett., 35, L17706, doi:10.1029/2008GL034842. Makowski, K., Wild, M., and Ohmura, A., 2008: Diurnal temperature range over Europe between 1950 and 2005, Atmos. Chem. Phys., 8, 6483-6498, 2008. Wild, M., Trüssel, B., Ohmura, A., Long, C.N. König-Langlo G., Dutton, E.G., and Tsvetkov, A., 2009: Global Dimming and Brightening: an update beyond 2000. Submitted to J. Geophys. Res. Wild, M., 2009a: Global dimming and brightening: A review on decadal changes in surface solar radiation. Submitted to J. Geophys. Res. Wild, M., 2009b: How well do the IPCC AR4/CMIP3 simulate global dimmingIbrightening and 20th century daytime and nighttime warming? Submitted to J. Geophys. Res.

Wild, M.; Makowski, K.; Chiacchio, M.; Folini, D.

2009-04-01

369

Estimation of the spatial validity of local aerosol measurements in Europe using MODIS data  

NASA Astrophysics Data System (ADS)

The actual impact of atmospheric aerosols in the Earth's radiative budget is still associated to large uncertainties [IPCC, 2007]. Global monitoring of the aerosol properties and distribution in the atmosphere is needed to improve our knowledge of climate change. The instrumentation used for this purpose can be divided into two main groups: ground-based and satellite-based. Ground-based instruments, like lidars or Sun-photometers, are usually designed to measure accurate local properties of atmospheric aerosols throughout the day. However, the spatial validity of these measurements is conditioned by the aerosol variability within the atmosphere. Satellite-based sensors offer spatially resolved information about aerosols at a global scale, but generally with a worse temporal resolution and in a less detailed way. In this work, the aerosol optical depth (AOD) at 550nm from MODIS Aqua, product MYD04 [Remer, 2005], is used to estimate the area of validity of local measurements at different reference points, corresponding to the AERONET [Holben, 1998] stations during the 2011-2012 period in Europe. For each case, the local AOD (AODloc) at each reference point is calculated as the averaged MODIS data within a radius of 15 km. Then, the AODloc is compared to the AOD obtained when a larger averaging radius is used (AOD(r)), up to 500 km. Only those cases where more than 50% of the pixels in each averaging area contain valid data are used. Four factors that could affect the spatial variability of aerosols are studied: proximity to the sea, human activity, aerosol load and geographical location (latitude and longitude). For the 76 reference points studied, which are sited in different regions of Europe, we have determined that the root mean squared difference (RMSD) between AODloc and AOD(r) , averaged for all cases, increases in a logarithmic way with the averaging radius (RMSD ? log(r)), while the linear correlation coefficient (R) decreases following a logarithmic trend (R ? -log(r)). Among all the factors studied, the aerosol load is the most influential one in the aerosol spatial variability: for averaging radii smaller than 40 km, the RMSD increases with AODloc. Another important factor is the latitude and longitude: the variation of the RMSD in the AOD with regard to the averaging radius can differ up to a 60%, depending on the location. On the contray, the proximity to the sea and the amount of population surrounding each reference point do not have a noticeable influence compared to the above mentioned factors. Holben, B. N., Eck, T. F., Slutsker, I., Buis, J. P., Setzer, A., Vermote, E., Reagan, J. A., Kaufman, Y., Nakajima, T., Lavenu, F., and Smirnov, A.: AERONET - A federated instrument network and data archive for aerosol characterization, Remote Sens. Environ., 66, 1-16, 1998. IPCC (2007). S. Solomon, D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor, H.L. Miller (Eds.), Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, UK & New York, USA. Remer, L. A., y co-authors, 2005: The MODIS aerosol algorithm, products, and validation. J. Atmos. Sci., 62, 947-973. doi: http://dx.doi.org/10.1175/JAS3385.1

Marcos, Carlos; Gómez-Amo, J. Luis; Pedrós, Roberto; Utrillas, M. Pilar; Martínez-Lozano, J. Antonio

2013-04-01

370

Dynamic processes associated with the eastern Mediterranean 'bomb' of 2004  

NASA Astrophysics Data System (ADS)

The meteorological "bomb" of the 21st and 22nd of January 2004, that affected the eastern Aegean Sea with very strong winds reaching 80 kts, excessive rain and even snow, with accumulations of at least one (1) meter on Limnos island and mean sea-level pressure at the record level of 972 hPa on Ikaria island, is studied from the synoptic and mostly dynamic concept. Lagouvardos and co-authors have already proved that the upper tropospheric PV anomaly was a necessary ingredient of the explosive cyclogenesis and the latter was attributed to the merger of troughs coming from North Africa and Europe. The present study is mainly concerned with the dynamic processes that led to the explosive cyclogenesis of 21 - 22 January 2004. Relying upon the use of the original ECMWF data information, a serious attempt is made to investigate, verify and justify the space and time of the "bomb explosion", the accompanied characteristics and the reasons causing the cyclolysis. Upper and lower tropospheric level forcing mechanisms are identified and monitored and a quantitative dynamical picture is provided for the explosively (pre) cyclogenetic period. The explosive cyclogenesis begins in Gabes Sea, just off the Libyan coast, the low forming on a frontogenetically active occlusion of a Saharan depression, when a tropopause fold/upper level front system crosses aloft. The occlusion is traced back to the Sahara desert, as a low level convergence/frontal zone, along which Qs vectors indicate an anticyclonic rotation of the warm part of the front. Dynamic tropopause maps show significant cold air advection just upstream the area of surface cyclogenesis on the 21st of January 2004. Consequently, an upper level vortex forms, which perturbs the thermal field, maximizing Q vector convergence above the bomb. Gradually the role of the tropopause decreases, as the upper level front system weakens. During these initial stages, when the low level vortex of the bomb is not yet well defined, the tropical front plays a key role in the explosive cyclogenesis. The warm conveyor belt of a tropical Saharan depression to the south of the bomb, travelling eastward parallel to the latter, advects warm air northwards. High ?e air is channeled into the trough of warm air aloft (TROWAL) of the initial Saharan depression, contributing to large-scale moist ascent above the bomb area. The associated deep diabatic heating, calculated as a residual from the thermodynamic equation, enhances cyclogenesis. The vorticity budget shows that vortex stretching, due to upper level forcing (initial stages) and low level frontogenesis (mainly final stages), plays a key role in the explosively cyclogenetic process. Soon the bomb turns into a frontogenetically active frontal depression. As the polar front approaches the Aegean, low level frontogenesis speeds up. The latter maximizes when frontal merger takes place. However, low ?e cold continental air, ingested into the bomb updraft through the polar front zone, contributes to a more stable profile, checking cyclogenesis. What actually stops cyclogenesis, is that tropical air masses do not any more ascend into the bomb vortex, as the tropical front moves southeast, away from the bomb, at these final stages of cyclogenesis.

Karacostas, T. S.; Brikas, D.; Pytharoulis, I.

2010-09-01

371

Measurement of Differential Cross-Sections in the ttbar -> l+jets Channel  

SciTech Connect

The analysis presented in this thesis focuses on kinematic distributions in the t{bar t} system and studies in detail selected differential cross sections of top quarks as well as the reconstructed t{bar t} pair, namely the top quark transverse momentum and the t{bar t} system mass. The structure of the thesis is organized as follows: first the Standard Model of the particle physics is briefly introduced in Chapter 1, with relevant aspects of electroweak and strong interactions discussed. The physics of the top quark and its properties are then outlined in Chapter 2, together with the motivation for measuring the transverse top quark momentum and other kinematic-related variables of the t{bar t} system. The concepts of present-day high energy physics collider experiments and the explicit example of Fermilab Tevatron collider and the D0 detector in Chapters 3 and 4 are followed by the description of basic detector-level objects, i.e. tracks, leptons and jets, in Chapter 5; their identification and calibration following in next chapter with the emphasis on the jet energy scale in Chapter 6 and jet identification at the D0. The analysis itself is outlined in Chapter 7 and is structured so that first the data and simulation samples and the basic preselection are described in Chapter 8 and 9, followed by the kinematic reconstruction part in Chapter 10. Chapter 11 on background normalization and Chapter 12 with raw reconstructed spectra results (at the detector-smeared level) are followed by the purity-based background subtraction method and examples of signal-level corrected spectra in Chapter 13. Next, the procedure of correcting measured spectra for detector effects (unfolding) is described in Chapters 14-15, including migration matrix studies, acceptance correction determination as well as the regularized unfolding procedure itself. Final differential cross sections are presented in Chapter 16 with the main results in Figures 16.19-16.20. Summary and discussion close the main analysis part in Chapter 17, supplemented by appendices on the wealthy of analysis control plots of the t{bar t} {yields} {ell} + jets channel, selected D0 event displays and finally the list of publications and references. Preliminary results of this analysis have been documented in D0 internal notes [UnfoldTop], [p17Top], [p14Top]; as well as presented at conferences [APS08], [APS05]. The author has also been a co-author of more than 135 D0 collaboration publications since 2005. The author has taken part in the jet energy scale calibration efforts performing final closure tests and deriving a correction to jet energy offset due to the suppression of the calorimeter signal. The author has also co-performed the {phi}-intercalibration of the hadronic calorimeter and co-supervised the electromagnetic {phi}-intercalibration; recently has also been involved in maintaining the jet identification efficiencies measurement as a JetID convener. During the years in Fermilab, many events have taken place in the course of the analysis in persuasion, including more than 170 shifts served for the D0 detector with or without the beam, 168 talks presented with mixed results and reactions; and tens of thousands of code lines in C (and sometimes perhaps even really C++) written while terabytes of data were processed, analyzed, and sometimes also lost. It has been a long but profoundly enriching chapter of my life.

Kvita, J.; /Charles U.

2009-04-01

372

A "Genetic Study" of the Galaxy  

NASA Astrophysics Data System (ADS)

Looking in detail at the composition of stars with ESO's VLT, astronomers are providing a fresh look at the history of our home galaxy, the Milky Way. They reveal that the central part of our Galaxy formed not only very quickly but also independently of the rest. "For the first time, we have clearly established a 'genetic difference' between stars in the disc and the bulge of our Galaxy," said Manuela Zoccali, lead author of the paper presenting the results in the journal Astronomy and Astrophysics [1]. "We infer from this that the bulge must have formed more rapidly than the disc, probably in less than a billion years and when the Universe was still very young." ESO PR Photo 34a/06 ESO PR Photo 34a/06 The Field around Baade's Window The Milky Way is a spiral galaxy, having pinwheel-shaped arms of gas, dust, and stars lying in a flattened disc, and extending directly out from a spherical nucleus of stars in the central region. The spherical nucleus is called a bulge, because it bulges out from the disc. While the disc of our Galaxy is made up of stars of all ages, the bulge contains old stars dating from the time the galaxy formed, more than 10 billion years ago. Thus, studying the bulge allows astronomers to know more about how our Galaxy formed. To do this, an international team of astronomers [2] analysed in detail the chemical composition of 50 giant stars in four different areas of the sky towards the Galactic bulge. They made use of the FLAMES/UVES spectrograph on ESO's Very Large Telescope to obtain high-resolution spectra. The chemical composition of stars carries the signature of the enrichment processes undergone by the interstellar matter up to the moment of their formation. It depends on the previous history of star formation and can thus be used to infer whether there is a 'genetic link' between different stellar groups. In particular, comparison between the abundance of oxygen and iron in stars is very illustrative. Oxygen is predominantly produced in the explosion of massive, short-lived stars (so-called Type II supernovae), while iron instead originates mostly in Type Ia supernovae [3], which can take much longer to develop. Comparing oxygen with iron abundances therefore gives insight on the star birth rate in the Milky Way's past. ESO PR Photo 34b/06 ESO PR Photo 34b/06 The Oxygen Abundance in the Bulge "The larger size and iron-content coverage of our sample allows us to draw much more robust conclusions than were possible until now," said Aurelie Lecureur, from the Paris-Meudon Observatory (France) and co-author of the paper. The astronomers clearly established that, for a given iron content, stars in the bulge possess more oxygen than their disc counterparts. This highlights a systematic, hereditary difference between bulge and disc stars. "In other words, bulge stars did not originate in the disc and then migrate inward to build up the bulge but rather formed independently of the disc," said Zoccali. "Moreover, the chemical enrichment of the bulge, and hence its formation timescale, has been faster than that of the disc." Comparisons with theoretical models indicate that the Galactic bulge must have formed in less than a billion years, most likely through a series of starbursts when the Universe was still very young.

2006-09-01

373

Star Surface Polluted by Planetary Debris  

NASA Astrophysics Data System (ADS)

Looking at the chemical composition of stars that host planets, astronomers have found that while dwarf stars often show iron enrichment on their surface, giant stars do not. The astronomers think that the planetary debris falling onto the outer layer of the star produces a detectable effect in a dwarf star, but this pollution is diluted by the giant star and mixed into its interior. "It is a little bit like a Tiramisu or a Capuccino," says Luca Pasquini from ESO, lead-author of the paper reporting the results. "There is cocoa powder only on the top!' ESO PR Photo 29/07 ESO PR Photo 29/07 The Structure of Stars Just a few years after the discovery of the first exoplanet it became evident that planets are preferentially found around stars that are enriched in iron. Planet-hosting stars are on average almost twice as rich in metals than their counterparts with no planetary system. The immediate question is whether this richness in metals enhances planet formation, or whether it is caused by the presence of planets. The classic chicken and egg problem. In the first case, the stars would be metal-rich down to their centre. In the second case, debris from the planetary system would have polluted the star and only the external layers would be affected by this pollution. When observing stars and taking spectra, astronomers indeed only see the outer layers and can't make sure the whole star has the same composition. When planetary debris fall onto a star, the material will stay in the outer parts, polluting it and leaving traces in the spectra taken. A team of astronomers has decided to tackle this question by looking at a different kind of stars: red giants. These are stars that, as will the Sun in several billion years, have exhausted the hydrogen in their core. As a result, they have puffed up, becoming much larger and cooler. Looking at the distribution of metals in fourteen planet-hosting giants, the astronomers found that their distribution was rather different from normal planet-hosting stars. "We find that evolved stars are not enriched in metals, even when hosting planets," says Pasquini. "Thus, the anomalies found in planet-hosting stars seem to disappear when they get older and puff up!" Looking at the various options, the astronomers conclude that the most likely explanation lies in the difference in the structure between red giants and solar-like stars: the size of the convective zone, the region where all the gas is completely mixed. In the Sun, this convective zone comprises only 2% of the star's mass. But in red giants, the convective zone is huge, encompassing 35 times more mass. The polluting material would thus be 35 times more diluted in a red giant than in a solar-like star. "Although the interpretation of the data is not straightforward, the simplest explanation is that solar-like stars appear metal-rich because of the pollution of their atmospheres," says co-author Artie Hatzes, Director of the Thüringer Landessternwarte Tautenburg (Germany) where some of the data were obtained. When the star was still surrounded by a proto-planetary disc, material enriched in more heavy elements would fall onto the star, thereby polluting its surface. The metal excess produced by this pollution, while visible in the thin atmospheres of solar-like stars, is completely diluted in the extended, massive atmospheres of the giants.

2007-07-01

374

Editorial: A dedication to Professor Jan Evetts  

NASA Astrophysics Data System (ADS)

A few days before the beginning of the 7th European Conference on Applied Superconductivity we learned that Professor Jan Evetts, a pioneer of superconductor research, a brilliant scientist, a wonderful person and a great personal friend, had passed away. We therefore decided to dedicate the 7th European Conference on Applied Superconductivity to the memory of Jan Evetts. The following citation is based on material provided by his former supervisor (D Dew-Hughes) and his closest co-workers in Cambridge. Professor Jan Edgar Evetts (1939-2005) Professor Jan Edgar Evetts (1939-2005) Jan Evetts passed away after losing his second battle with cancer on 24th August 2005. He made an outstanding series of contributions to the science of superconductivity and to the understanding of superconducting materials and was an indefatigable champion of the development of applications of superconductivity. The loss to the superconductivity community is incalculable, as attested by the many communications received from colleagues throughout the world. Jan was born on 31 March 1939, and attended the Dragon School in Oxford, and later Haileybury. He was awarded an exhibition to read Natural Sciences at Pembroke College, Cambridge. He entered the college in 1958 and took his BA degree in 1961. He then undertook a Certificate of Postgraduate Study in Physics under the supervision of Professor Neville Mott. He was the first student to undertake this newly-instituted course; the title of his thesis was `The Resistance of Transition Metals'. In 1962 he joined David Dew-Hughes' superconducting materials research group, along with Archie Campbell and Anant Narlikar. In fact it was Jan's enthusiasm for the proposed course of research that helped convince David that he should follow Professor Alan Cottrell's suggestion to apply metallurgical methodology to the study of the factors that controlled critical current density in the type II superconductors that were then under development for applications in magnets. Competing theories for the critical current density at that time were fine filaments or `Mendelssohn Sponge' versus the pinning of Abrikosov quantized vortices. The results of the group's work, to which Jan made a major contribution, came down heavily in favour of the latter theory. Jan's outstanding characteristic was his meticulous and painstaking approach to every piece of work that he tackled. His attention to detail, and his ability to design elegant experiments, was unique. He was awarded a PhD for his thesis `The Magnetisation of Superconducting Lead Alloys'. The work on flux pinning culminated in the publication of `Critical Currents in Superconductors', a research monograph (co-authored with Archie Campbell) that rapidly became the standard reference work in the field. It has recently been reprinted in the Advances in Physics `Classic Articles' series as the 9th most cited article in the journal's history (2001 Adv. Phys. 50 1249-449). Jan was appointed to a research fellowship at Pembroke College and to a Science Research Council Research Fellowship in the Department of Metallurgy in 1965. After David Dew-Hughes left Cambridge, Jan inherited the superconducting materials research group and was appointed University Demonstrator in Metallurgy and a full Fellow in Pembroke College in 1966. He progressed steadily through the various levels of academic rank, finally being appointed Professor of Device Materials in 1998. Under his direction his research group grew until it comprised some 40 people, and expanded its research interests to thin films and magnetic materials. Jan's work on superconductivity was always paralleled by research on magnetic materials; the cross fertilization between disciplines has been very fruitful and led to him editing Pergamon's `Concise Encyclopedia of Magnetic and Superconducting Materials' in 1992. This work has been a major success with a world-wide readership. To give a more personal picture of Jan and his achievements one can do no better than to quote in full the eulogy delivered by Professor Archie Cam

Weber, Harald; Dew-Hughes, David; Campbell, Archie; Barber, Zoe; Somekh, Rob; Glowacki, Bartek

2006-03-01

375

OBITUARY: Professor Jan Evetts in memoriam  

NASA Astrophysics Data System (ADS)

It is with great sadness that we report the death of Jan Evetts, who lost his second battle with cancer on 18 August 2005. In 1988 he was appointed Founding Editor of this journal where his leadership created the foundation upon which its success rests today. He made an outstanding series of contributions to the science of superconductivity and to the understanding of superconducting materials, and was an indefatigable champion of the development of applications of superconductivity. The loss to the scientific community is incalculable, as is attested by the many communications received from colleagues throughout the world. Professor Jan Edgar Evetts (1939-2005) Professor Jan Edgar Evetts (1939-2005) Jan was born on 31 March 1939, and attended the Dragon School in Oxford, and later Haileybury. He was awarded an exhibition to read Natural Sciences at Pembroke College, Cambridge in 1958 and took his BA degree in 1961. He then undertook a Certificate of Postgraduate Study in Physics under the supervision of Professor Neville Mott. He was the first student to undertake this newly-instituted course; the title of his thesis was `The Resistance of Transition Metals'. In 1962 he joined David Dew-Hughes' embryonic superconducting materials research group, along with Archie Campbell and Anant Narlikar. In fact it was Jan's enthusiasm for the proposed course of research that helped convince David that he should follow Professor Alan Cottrell's suggestion to apply metallurgical methodology to the study of the factors that controlled critical current density in the type II superconductors that were then under development for applications in magnets. Competing theories for the critical current density at that time were fine filaments or `Mendelssohn Sponge' versus the pinning of Abrikosov quantized vortices. The results of the group's work, to which Jan made a major contribution, came down heavily in favour of the latter theory. Jan's outstanding characteristic was his meticulous and painstaking approach to every piece of work that he tackled. His attention to detail, and his ability to design elegant experiments, was unique. He was awarded a PhD for his thesis `The Magnetisation of Superconducting Lead Alloys'. The work on flux pinning culminated in the publication of `Critical Currents in Superconductors', a research monograph (co-authored with Archie Campbell) that rapidly became the standard reference work in the field. It has recently been reprinted in the Advances in Physics `Classic Articles' series as the 9th most cited article in the journal's history (2001 Adv. Phys. 50 1249-449). Jan was appointed to a research fellowship at Pembroke College and to a Science Research Council Research Fellowship in the Department of Metallurgy in 1965. After David Dew-Hughes left Cambridge, Jan inherited the superconducting materials research group and was appointed University Demonstrator in Metallurgy and a full Fellow in Pembroke College in 1966. He progressed steadily through the various levels of academic rank, finally being appointed Professor of Device Materials in 1998. Employing an astonishing combination of administrative skill, long term planning, manipulation of the University system and high quality research at the top international level, Jan built up the largest superconductivity group in the UK, comprising some 40 members. Five of his group obtained permanent positions in the Metallurgy Department, and there are many scientists all over the world, as well as many in Cambridge, who owe their careers to him. Jan served on many UK and European Committees, and in the organization of several international conferences. The major event of the 1980s was undoubtedly the discovery of high temperature superconductivity. Jan's group was well placed to move very rapidly into this area and the paper submitted to Nature in March 1987 was the first in the literature to report the deposition of a thin ceramic film with a 90 K superconducting transition temperature. During 1987 Jan helped co-ordinate the successful Cambridge University applica

Dew-Hughes, David; Campbell, Archie; Glowacki, Bartek

2005-11-01

376

A New Way To Weigh Giant Black Holes  

NASA Astrophysics Data System (ADS)

How do you weigh the biggest black holes in the universe? One answer now comes from a completely new and independent technique that astronomers have developed using data from NASA's Chandra X-ray Observatory. By measuring a peak in the temperature of hot gas in the center of the giant elliptical galaxy NGC 4649, scientists have determined the mass of the galaxy’s supermassive black hole. The method, applied for the first time, gives results that are consistent with a traditional technique. Astronomers have been seeking out different, independent ways of precisely weighing the largest supermassive black holes, that is, those that are billions of times more massive than the Sun. Until now, methods based on observations of the motions of stars or of gas in a disk near such large black holes had been used. "This is tremendously important work since black holes can be elusive, and there are only a couple of ways to weigh them accurately," said Philip Humphrey of the University of California at Irvine, who led the study. "It's reassuring that two very different ways to measure the mass of a big black hole give such similar answers." AnimationChandra X-ray Image NGC 4649 is now one of only a handful of galaxies for which the mass of a supermassive black hole has been measured with two different methods. In addition, this new X-ray technique confirms that the supermassive black hole in NGC 4649 is one of the largest in the local universe with a mass about 3.4 billion times that of the Sun, about a thousand times bigger than the black hole at the center of our galaxy. The new technique takes advantage of the gravitational influence the black hole has on the hot gas near the center of the galaxy. As gas slowly settles towards the black hole, it gets compressed and heated. This causes a peak in the temperature of the gas right near the center of the galaxy. The more massive the black hole, the bigger the temperature peak detected by Chandra. People Who Read This Also Read... Milky Way’s Giant Black Hole Awoke from Slumber 300 Years Ago Black Holes Are The Rhythm at The Heart of Galaxies Discovery of Most Recent Supernova in Our Galaxy Ghost Remains After Black Hole Eruption This effect was predicted by two of the co-authors -- Fabrizio Brighenti from the University of Bologna, Italy, and William Mathews from the University of California at Santa Cruz -- almost 10 years ago, but this is the first time it has been seen and used. "It was wonderful to finally see convincing evidence of the effects of the huge black hole that we expected," said Brighenti. "We were thrilled that our new technique worked just as well as the more traditional approach for weighing the black hole." The black hole in NGC 4649 is in a state where it does not appear to be rapidly pulling in material towards its event horizon, nor generating copious amounts of light as it grows. So, the presence and mass of the central black hole has to be studied more indirectly by tracking its effects on stars and gas surrounding it. This technique is well suited to black holes in this condition. "Monster black holes like this one power spectacular light shows in the distant, early universe, but not in the local universe," said Humphrey. "So, we can’t wait to apply our new method to other nearby galaxies harboring such inconspicuous black holes." These results will appear in an upcoming issue of The Astrophysical Journal. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the agency's Science Mission Directorate. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass.

2008-07-01

377

3-Bromopyruvate (3BP) a fast acting, promising, powerful, specific, and effective "small molecule" anti-cancer agent taken from labside to bedside: introduction to a special issue.  

PubMed

Although the "Warburg effect", i.e., elevated glucose metabolism to lactic acid (glycolysis) even in the presence of oxygen, has been recognized as the most common biochemical phenotype of cancer for over 80 years, its biochemical and genetic basis remained unknown for over 50 years. Work focused on elucidating the underlying mechanism(s) of the "Warburg effect" commenced in the author's laboratory in 1969. By 1985 among the novel findings made two related most directly to the basis of the "Warburg effect", the first that the mitochondrial content of tumors exhibiting this phenotype is markedly decreased relative to the tissue of origin, and the second that such mitochondria have markedly elevated amounts of the enzyme hexokinase-2 (HK2) bound to their outer membrane. HK2 is the first of a number of enzymes in cancer cells involved in metabolizing the sugar glucose to lactic acid. At its mitochondrial location HK2 binds at/near the protein VDAC (voltage dependent anion channel), escapes inhibition by its product glucose-6-phosphate, and gains access to mitochondrial produced ATP. As shown by others, it also helps immortalize cancer cells, i.e., prevents cell death. Based on these studies, the author's laboratory commenced experiments to elucidate the gene basis for the overexpression of HK2 in cancer. These studies led to both the discovery of a unique HK2 promoter region markedly activated by both hypoxic conditions and moderately activated by several metabolites (e.g., glucose), Also discovered was the promoter's regulation by epigenetic events (i.e., methylation, demethylation). Finally, the author's laboratory turned to the most important objective. Could they selectively and completely destroy cancerous tumors in animals? This led to the discovery in an experiment conceived, designed, and conducted by Young Ko that the small molecule 3-bromopyruvate (3BP), the subject of this mini-review series, is an incredibly powerful and swift acting anticancer agent. Significantly, in subsequent experiments with rodents (19 animals with advanced cancer) Ko led a project in which 3BP was shown in a short treatment period to eradicate all (100%). Ko's and co-author's findings once published attracted global attention leading world-wide to many other studies and publications related to 3BP and its potent anti-cancer effect. This Issue of the Journal of Bioenergetics and Biomembranes (JOBB 44-1) captures only a sampling of research conducted to date on 3BP as an anticancer agent, and includes also a Case Report on the first human patient known to the author to be treated with specially formulated 3BP. Suffice it to say in this bottom line, "3BP, a small molecule, results in a remarkable therapeutic effect when it comes to treating cancers exhibiting a "Warburg effect". This includes most cancer types. PMID:22382780

Pedersen, Peter L

2012-02-01

378

[Man and his fellow-creatures under ethical aspects].  

PubMed

It is for reasons of age I will have to terminate my work at the Literary Review in the form developed since 1995. The report is being reduced to a concentration of ethically relevant reviews as exemplified in the fourth-quarter issue of ALTEX. This is to ascertain that essential developments in this field will not be overlooked. Insofar, the Literary Review will be continued under the heading "New literature concerning topics of animal ethics". The more central topics of animal ethics are being "used up" the more new questions are being formulated. Thus it was that during the last few years the plant-world, long neglected, was rediscovered and received attention through the publication of important works. Another recent discovery concerns itself with "cognitive ethology" which developed out of the critique of behaviourism and which is dealt with in a separate chapter in this issue. But there is also a "classic" of ethics who has been reviewed and interpreted anew repeatedly. In her book "Albert Schweitzer, a prophet of medical ethics", Heike Baranzke describes Schweitzer's ethics as not sentimental or nostalgic but rather as a radically modern stance, committed to the enlightenment. Manuel Schneider, also, conveys a comprehensive view of Albert Schweitzer's ethics in "Life in the middle of life - the relevance of the ethics of Albert Schweitzer", a book edited by Altner, Frambach, Gottwald and himself in 2005. For this, in particular, he derives a possibility of a physiocentric ethics. By contrast, Beate Weinzierl approaches Schweitzer on a complete personal and human level in "Yearning for nature - access to inner and outer nature with Albert Schweitzer". Wolfgang Senz is undertaking a critical appreciation of Albert Schweitzer's concept of "life" and this, foremost, in the light of Schweitzer's rejection of the Cartesian "I am". In the end, Jean Claude Wolf cannot manage without citing Schweitzer either, referring to him in his not accepting the (western) world's excessive meat consumption as a "cruel necessity". Klaus Peter Joern also enters into Schweitzer's fundamental argumentation in his "A good bye to the disparagement of our fellow creatures". Quotation: "It just cannot go on that Christianity lets the validity of the commandment of love end at the behaviour towards humans, simply because that is the tradition. We rather have to, in this instance, deny the authority of the Bible it's due respect, as this has deemed Schweitzer already inevitable." The killing of animals, irrespective of the motives, remains a critical issue in the understanding (or the lack thereof) with regard to the dignity of all creation. Manuela Linnemann, Charles Patterson, Evelyn Ofensberger and the German Veterinary Association for the Protection of Animals have dealt with this issue extensively. As always, more space is taken up by publications dealing with legal questions and developments. In particular, the conference report of the Protestant Academy at Bad Boll should be mentioned "Animal protection on good constitution". Contributions to this report, edited by the academy, include Hans Georg Kluge's "The governmental aim 'animal protection' and it's implementation in jurisdiction" and Johannes Caspar's "effects of the governmental goal 'animal protection' in the protected area of unconditional fundamental rights". Regarding animal experiments, the last two position papers commissioned by the Foundation for animal-free research (FFVFF), dealing with perspectives of 3R research, have been published within the period of time covered by this report. Alternatives in basic research (with once again rising numbers of experimental animals) and in biomedical education are the themes dealt with by Franz P. Gruber and his co-authors Thomas Hartung and David Dewhurst. PMID:16344905

Teutsch, Gotthard M

2005-01-01

379

[Figures of first laureates of the Wiktor Dega medal (XXXVII Jubilee Congress of Polish Orthopaedic and Traumatologic Society, 10-13 September 2008)].  

PubMed

Figures of two outstanding orthopaedists Professor Stefan Malawski and Professor Jerzy Król rewarded with the medal of the name of Wiktor Degi were described. The medal is being granted by the Chapter of the Medal as regarding for outstanding achievements for the Polish and world orthopaedics and rehabilitation. Profesor Stefan Kazimierz Malawski was born 26. 12. 1920 in the Vilnius area. In Vilnius he stated his medical studies, which he continued in Lwow and graduated in 1946 at the Marie Curie Sk?odowska in Lublin. Professor Malawski's main field of interest were related to the problems related to tuberculosis of bones and joints and trauma of the lumbar and cervical spine. In the problems of bone tuberculosis he remains an unquestioned authority in Poland. His deep understanding of these clinical problems can be found in his text-book "Tuberculosis of bones and joints", which was printed in 1976. The information pertaining diagnosis and surgical treatment remain extremely valuable today. Another field of interest of Professor Malawski are pathologies of the spine. Disc disease, neoplasms of the spine, spinal stenosis and infections of the spine, spondylolisthesis are among many of his interests. This very wide field of interest can be dound in his 3 tome publication Spondyloorthopedics. His 166 papars printed in Poland and abroad bear proof of the Professors wide field of interest and deep knowledge. Professor Malawski was the first surgeon in Poland to perform surgery on the front elements of the spine in tuberculotic paraplegia. In 1958 he implemented surgical treatment of spine tumor--both primary and metastatic, by resecting them and stabilizing the spine with grafts. In the early 70's he focused on spinal stenosis. In the years 1982-1986 he was the Chairman of the Board of the Polish Orthopedic and Trauma Society. Professor Malawski introdued a modern set of Rules and Regulations, greatly simplifying the decision making process during General assemblies of the Society. Professor Malawski is undoubtedly a great successor to the active way of surgical thinking introduced by professor Adam Gruca. Professor Jerzy Król is among the greatest Polish orthopedic surgeons. He was born on 21st February 1926 in Baranowice (Nowogródek woiwodship). He graduated from high school in the underground schooling system during the Second World War, receiving his maturity exam in 1945 from the Konarski High Scool School of the Western Lands in Czestochowa. In 1945 the professor started his medical studies at Adam Mickiewicz University of Poznan, where he graduated in 1949. In 1950 he started his medical career in in Orthopedic Department of Poznan head by professor Wiktor Dega. Professor Król is the author of over 100 medical papers printed in national and international journals. His key fields of interest are congenital dislocation of the hip, hip arthroplasty, scoliosis and rehabilitaton and prosthesis problems. In 1968 he performed the first scoliosis correction with the Harrington rod in Poland as well as the implantation of the first McKee-Ferara hip prosthesis. He is the co-author of the text-book Orthopedics and Rehabilitation, Medical Rehabilitation and a number of WHO text books: Community Health Worker and Guide for prevention of Deformities in Poliomyelitis. He also took part in the publishing of the WHO text-book Rehabilitation Surgery, for which he received the Ministry of Health Award. He overlooked 7 Ph.D thesis and 4 papers qualifying for assistant professor. Between 1972 and 1995 professor Król worked as a WHO expert, as member of the Expert Committee for Rehabilitation. Between 1986-1987 head was the director of the Orthopedics and Rehabilitation Institute in Poznan. He resigned from this function due to his work with WHO in Madagaskar. After his return he was the head of the Orthopedic Department in Poznan University of Medical Sciennces until October 1996 when he retired. PMID:19241890

Nowakowski, Andrzej; Rapa?a, Kazimierz

380

NASA's Chandra Reveals Origin of Key Cosmic Explosions  

NASA Astrophysics Data System (ADS)

WASHINGTON -- New findings from NASA's Chandra X-ray Observatory have provided a major advance in understanding a type of supernova critical for studying the dark energy that astronomers think pervades the universe. The results show mergers of two dense stellar remnants are the likely cause of many of the supernovae that have been used to measure the accelerated expansion of the universe. These supernovae, called Type Ia, serve as cosmic mile markers to measure expansion of the universe because they can be seen at large distances, and they follow a reliable pattern of brightness. However, until now, scientists have been unsure what actually causes the explosions. "These are such critical objects in understanding the universe," said Marat Gilfanov of the Max Planck Institute for Astrophysics in Germany and lead author of the study that appears in the Feb. 18 edition of the journal Nature. "It was a major embarrassment that we did not know how they worked. Now we are beginning to understand what lights the fuse of these explosions." Most scientists agree a Type Ia supernova occurs when a white dwarf star -- a collapsed remnant of an elderly star -- exceeds its weight limit, becomes unstable and explodes. Scientists have identified two main possibilities for pushing the white dwarf over the edge: two white dwarfs merging or accretion, a process in which the white dwarf pulls material from a sun-like companion star until it exceeds its weight limit. "Our results suggest the supernovae in the galaxies we studied almost all come from two white dwarfs merging," said co-author Akos Bogdan, also of Max Planck. "This is probably not what many astronomers would expect." The difference between these two scenarios may have implications for how these supernovae can be used as "standard candles" -- objects of a known brightness -- to track vast cosmic distances. Because white dwarfs can come in a range of masses, the merger of two could result in explosions that vary somewhat in brightness. Because these two scenarios would generate different amounts of X-ray emission, Gilfanov and Bogdan used Chandra to observe five nearby elliptical galaxies and the central region of the Andromeda galaxy. A Type 1a supernova caused by accreting material produces significant X- ray emission prior to the explosion. A supernova from a merger of two white dwarfs, on the other hand, would create significantly less X-ray emission than the accretion scenario. The scientists found the observed X-ray emission was a factor of 30 to 50 times smaller than expected from the accretion scenario, effectively ruling it out. This implies that white dwarf mergers dominate in these galaxies. An open question remains whether these white dwarf mergers are the primary catalyst for Type Ia supernovae in spiral galaxies. Further studies are required to know if supernovae in spiral galaxies are caused by mergers or a mixture of the two processes. Another intriguing consequence of this result is that a pair of white dwarfs is relatively hard to spot, even with the best telescopes. "To many astrophysicists, the merger scenario seemed to be less likely because too few double-white-dwarf systems appeared to exist," said Gilfanov. "Now this path to supernovae will have to be investigated in more detail." In addition to the X-rays observed with Chandra, other data critical for this result came from NASA's Spitzer Space Telescope and the ground-based, infrared Two Micron All Sky Survey. The infrared brightness of the galaxies allowed the team to estimate how many supernovae should occur. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra's science and flight operations from Cambridge, Mass. More information, including images and other multimedia, can be found at: http://chandra.harvard.edu and http://chandra.nasa.gov

2010-02-01

381

Obituary: John Louis Africano III, 1951-2006  

NASA Astrophysics Data System (ADS)

The orbital debris, space surveillance, and astronomical communities lost a valued and beloved friend when John L. Africano passed away on July 27, 2006, at the young age of 55. John passed away in Honolulu, Hawaii, from complications following a heart attack suffered while playing racquetball, which was his avocation in life. Born on February 8, 1951, in Saint Louis, Missouri, John graduated with a B.S. in Physics from the University of Missouri at Saint Louis in 1973, and received a Master's degree in Astronomy from Vanderbilt University in 1974. John had a real love for astronomical observing and for conveying his many years of experience to others. He encouraged many young astronomers and mentored them in the basics of photometry and astronomical instrumentation. John was author or co-author on nearly one-hundred refereed publications ranging from analyses of cool stars to the timing of occultations to space surveillance. He was honored for his contributions to minor planet research when the Jet Propulsion Laboratory named Minor Planet 6391 (Africano) after him. John held operational staff positions at several major observatories including McDonald Observatory in Texas, Kitt Peak National Observatory in Arizona, and the Cloudcroft Telescope Facility in New Mexico. He observed at numerous observatories worldwide, including Cerro Tololo Inter-American Observatory (CTIO) in Chile, developing a world-wide network of friends and colleagues. John's ability to build diverse teams through his managerial and technical skills, not to mention his smiling personality, resulted in numerous successes in the observational astronomy and space surveillance arenas. As an astronomer for Boeing LTS Inc., he worked for many years at the Advanced Maui Optical and Space Surveillance site (AMOS) on Maui, Hawaii, where he contributed his operational and instrumental expertise to both the astronomy and space surveillance communities. He was also the co-organizer of the annual AMOS Technical Conference whose attendance expanded dramatically during his tenure. John moved to the NASA Johnson Space Center, Houston, Texas, in 1998 to work full time on orbital debris projects including the 3.0 meter Liquid Mirror Telescope and the CCD Debris Telescope in Cloudcroft, New Mexico. In 2000 he moved back to Colorado Springs, Colorado, to be closer to his family. From there he continued to support both the NASA Orbital Debris Program Office (ODPO) and AMOS. John was very instrumental in establishing cooperative programs between the ODPO and AMOS, which will benefit both organizations for many years to come. John left an indelible mark on his programs and all those who knew and loved him. The impact of his untimely departure will reverberate for many years. As John's wife Linda put it, "John is now visiting the stars and galaxies he adored from afar." John is survived by his wife, Linda Ann Africano; two sons, James Keith and Brian Michael; a daughter, Monica Lynn Africano; a sister, Diana Smith; and four grandchildren. The author acknowledges valuable input from Brian Africano (University of Colorado at Colorado Springs), Eugene Stansbery (NASA), Mark Mulrooney (NASA contractor), Tom Kelecy (Boeing LTS, Inc.), Paul Sydney (Boeing LTS, Inc.), Kira Abercromby (NASA contractor), and Patrick Seitzer (University of Michigan).

Barker, Edwin, S.

2007-12-01

382

BOOK REVIEW: Experimental Stochatics (2nd edition)  

NASA Astrophysics Data System (ADS)

Otto Moeschlin and his co-authors have written a book about simulation of stochastic systems. The book comes with a CD-ROM that contains the experiments discussed in the book, and the text from the book is repeated on the CD-ROM. According to the authors, the aim of the book is to give a quick introduction to stochastic simulation for `all persons interested in experimental stochastics'. To please this diverse audience, the authors offer a book that has four parts. Part 1, called `Artificial Randomness', is the longest of the four parts. It gives an overview of the generation, testing and basic usage of pseudo random numbers in simulation. Although algorithms for generating sequences of random numbers are fundamental to simulation, it is a slightly unusual choice to give it such weight in comparison to other algorithmic topics. The remaining three parts consist of simulation case studies. Part 2, `Stochastic Models', treats four problems---Buffon's needle, a queuing system, and two problems related to the kinetic theory of gases. Part 3 is called `Stochastic Processes' and discusses the simulation of discrete time Markov chains, birth--death processes, Brownian motion and diffusions. The last section of Part 3 is about simulation as a tool to understand the traffic flow in a system controlled by stoplights, an area of research for the authors. Part4 is called `Evaluation of Statistical Procedures'. This section contains examples where simulation is used to test the performance of statistical methods. It covers four examples: the Neymann--Pearson lemma, the Wald sequential test, Bayesian point estimation and Hartigan procedures. The CD-ROM contains an easy-to-install software package that runs under Microsoft Windows. The software contains the text and simulations from the book. What I found most enjoyable about this book is the number of topics covered in the case studies. The highly individual selection of applications, which may serve as a source of inspiration for teachers of computational stochastic methods, is the main contribution of this electronic monograph. However, both the book and software suffer from several severe problems. Firstly, I feel that the structure of the text is weak. Probably this is partly the result of the text from the CD-ROM being put into a book format, but the short paragraphs and poorly structured sentences destroy the reading experience. Secondly, although the software is functional, I believe that, like me, many users will be disappointed by the quality of the user interface and the visualizations. The opportunities to interact with the simulations are limited. Thirdly, the presentation is slightly old fashioned and lacking in pedagogical structure. For example, flow charts and Pascal programs are used to present algorithms. To conclude, I am surprised that this electronic monograph warranted a second edition in this form. Teachers may find the examples useful as a starting point, but students and researchers are advised to look elsewhere. JG was supported by KBN grant no 2 P03A 020 24.

Wiberg, P.

2004-05-01

383

The water cycle in a bottle: simulation of a hydrogeological basin  

NASA Astrophysics Data System (ADS)

THE WATER CYCLE IN A BOTTLE: simulation of a hydrogeological basin Author: Mª Roser Nebot (Institut Manuel Blancafort, La Garriga, Barcelona, Spain) Co-author: Sílvia Leiva Hevia (Institut Llicà d'Amunt, Lliça d'Amunt, Barcelona, Spain) The activity can be implemented in a great range of ages, because it has many different levels of depth. It is based on the construction of an analogical model of a hydrogeological basin using a 5L or 8L empty bottle. There are also other hands-on experiences that can be done in relation to the central one, such as creating a fountain, making a cloud, fog, a breeze… The use of a model that the students have to build and interact with enhances the possibility of cooperative and dialogic learning. The set of activities begins with an introduction to see what the students know about the water cycle and to focus on what they are going to work on. It also makes them think about underground water, which is frequently forgotten when drawing and studying the water cycle. Then, the building of the water cycle simulation from an empty bottle is presented, see http://www.xtec.cat/cirel/pla_le/nottingham/roser_nebot/index.htm (Unit 5). You will also find other activities related to the water cycle at the site. The students build the model, water the soil, and observe infiltration and the formation of a lake. Using a syringe they overexploit the well and dry the lake. By making the students label the underground water level and observe how water percolates through the holes in the aquifer we are making them aware that underground water doesn't circulate in rivers inside underground tunnels, but through the interconnected holes and crevices. Inside the bottle there is a little plant to observe evapotranspiration but, because it is very difficult to see the water droplets in the small plant that is inside the set-up, it is advisable to do a parallel experiment using bigger plants in a pot, covering them with a plastic bag tied around the stem, with the soil exposed to air, leaving some of them in the shade and some in the sun. The origin of condensation is thoroughly discussed so that the students understand that evapotranspiration comes from the addition of transpiration (plants) to evaporation. The students also add colouring to simulate contamination and salt to simulate marine intrusion. These activities, together with the overexploitation, help to understand how humans affect nature and how the effects are not the same in different parts of the world. To finish, there are different exercises to review, summarize and complement all that has been learnt through the lesson. To acknowledge the fact that many times underground water is forgotten, as homework they have to surf the net to see the many water cycle drawings and animations that don't show the water in the aquifers, and sometimes when the water is seen, the rocks that contain it are not depicted. They are also encouraged to realize that in water cycle representations, it never rains over the sea and that to adjust to what really happens and that there should also be rain over the oceans and seas. To finish, the idea that within the water cycle model there are many interrelated processes is discussed

Nebot Castelló, M. R.; Leiva Hevia, S.

2012-04-01

384

Late Cenozoic geology and lacustrine history of Searles Valley, Inyo and San Bernardino Counties, California  

NASA Astrophysics Data System (ADS)

George Smith’s career-long study of the surface geology of the Searles Valley was recently published by the USGS (Smith, 2009, online and printed). The co-authors of this abstract are the team responsible for completing the publication from the original materials. Searles Valley is an arid, closed basin lying 70 km east of the south end of the Sierra Nevada, California. During those parts of late Pliocene and Pleistocene time when precipitation and runoff from the east side of the Sierra Nevada into the Owens River were much greater than at present, a chain of as many as five large lakes was created, of which Searles Lake was third. The stratigraphic record left in Searles Valley when that lake expanded, contracted, or desiccated is fully revealed by cores taken from beneath the surface of Searles (dry) Lake and partly recorded by sediments cropping out around the edge of the valley. Although this outcrop record is discontinuous, it provides direct evidence of the lake’s water depths during each expansion, which the subsurface record does not. Maximum-depth lakes rose to the 2,280-ft (695 m) contour, the level of the spillway that led overflowing waters to Panamint Valley; that spillway is about 660 ft (200 m) above the present dry-lake surface. Most of this study concerns sediments of the newly described Searles Lake Formation, whose deposition spanned the period between about 150 ka and 2 ka. The outcrop record is documented in six geologic maps (scales: 1:50,000 and 1:10,000). The Searles Lake Formation is divided into seven main units. The depositional intervals of the units that make up the Searles Lake Formation are determined primarily by correlation with subsurface deposits that are dated by radiocarbon ages on organic carbon and U-series dates on salts. Shorelines, the most obvious geologic expressions of former lakes, are abundant around Searles Valley. Erosional shorelines have cut as much as 100 m into brecciated bedrock; depositional shorelines (beaches or tufa benches) are common, but their deposits tend to be thin. Combining the subsurface evidence of lake history with the outcrop record allows the history of lake fluctuations to be reconstructed for the period between about 150 ka and the present. Translating this record of lake fluctuations into paleohydrologic and paleoclimatic histories is complicated by uncertainties as to which of the several components of climate affected runoff volumes and lake-surface evaporation. A simplified model, however, suggests that the flow of the Owens River stayed between 2.5 and 4.5 times its present flow volume for most of the past 150 ky. Its flow exceeded this range only about 14 percent of the time, and it fell below this range only 4 percent of the time—which includes the present. In fact, the past 10 ky is clearly the driest period during the past 150 ky in the Owens River drainage. Smith, G.I., 2009, Late Cenozoic geology and lacustrine history of Searles Valley, Inyo and San Bernardino Counties, California: U.S. Geological Survey Professional Paper 1727, 115 p., 4 plates.

Nathenson, M.; Smith, G. I.; Robinson, J. E.; Stauffer, P. H.; Zigler, J. L.

2010-12-01

385

Essays on the Economics of Climate Change, Biofuel and Food Prices  

NASA Astrophysics Data System (ADS)

Climate change is likely to be the most important global pollution problem that humanity has had to face so far. In this dissertation, I tackle issues directly and indirectly related to climate change, bringing my modest contribution to the body of human creativity trying to deal with climate change. First, I look at the impact of non-convex feedbacks on the optimal climate policy. Second, I try to derive the optimal biofuel policy acknowledging the potential negative impacts that biofuel production might have on food supply. Finally, I test empirically for the presence of loss aversion in food purchases, which might play a role in the consumer response to food price changes brought about by biofuel production. Non-convexities in feedback processes are increasingly found to be important in the climate system. To evaluate their impact on the optimal greenhouse gas (GHG) abate- ment policy, I introduce non-convex feedbacks in a stochastic pollution control model. I numerically calibrate the model to represent the mitigation of greenhouse gas (GHG) emissions contributing to global climate change. This approach makes two contributions to the literature. First, it develops a framework to tackle stochastic non-convex pollu- tion management problems. Second, it applies this framework to the problem of climate change. This approach is in contrast to most of the economic literature on climate change that focuses either on linear feedbacks or environmental thresholds. I find that non-convex feedbacks lead to a decision threshold in the optimal mitigation policy, and I characterize how this threshold depends on feedback parameters and stochasticity. There is great hope that biofuel can help reduce greenhouse gas emissions from fossil fuel. However, there are some concerns that biofuel would increase food prices. In an optimal control model, a co-author and I look at the optimal biofuel production when it competes for land with food production. In addition oil is not exhaustible and output is subject to climate change induced damages. We find that the competitive outcome does not necessarily yield an underproduction of biofuels, but when it does, second best policies like subsidies and mandates can improve welfare. In marketing, there has been extensive empirical research to ascertain whether there is evidence of loss aversion as predicted by several reference price preference theories. Most of that literature finds that there is indeed evidence of loss aversion for many different goods. I argue that it is possible that some of that evidence seemingly supporting loss aversion arises because price endogeneity is not properly taken into account. Using scanner data I study four product categories: bread, chicken, corn and tortilla chips, and pasta. Taking prices as exogenous, I find evidence of loss aversion for bread and corn and tortilla chips. However, when instrumenting prices, the "loss aversion evidence" disappears.

Seguin, Charles

386

Obituary: Helen Dodson Prince, 1905-2002  

NASA Astrophysics Data System (ADS)

Helen Dodson Prince, a pioneer in the observation of solar flares, a pioneer in women's rise in the profession of astronomy, and a respected and revered educator of future astronomers, died on 4 February 2002 in Arlington, Virginia. Helen Dodson was born in Baltimore, Maryland, on 31 December 1905. Her parents were Helen Walter and Henry Clay Dodson. Helen went to Goucher College in nearby Towson with a full scholarship in mathematics. She turned to astronomy under the influence of a legendary teacher, Professor Florence P. Lewis, and she graduated in 1927. Funded by grants and private charity, she earned the Ph.D. in astronomy at the University of Michigan under the direction of Heber Doust Curtis in 1933. Dodson taught at Wellesley College from 1933 until 1943, when she went on leave to spend the last three years of World War II at the MIT Radiation Laboratory. She returned to Goucher after the war as professor of astronomy and mathematics, and in 1947 she came back to Michigan both as professor of astronomy and staff member of the McMath-Hulbert Observatory, of which she became associate director. In 1976 she retired from Michigan and spent her later years in Alexandria, Virginia. In 1932 Dodson held the Dean Van Meter fellowship from Goucher; in 1954 she received the Annie Jump Cannon Prize from the AAS; and in 1974 The University of Michigan honored her with its Faculty Distinguished Achievement Award. She published over 130 articles, mostly on her research specialty, solar flares. Dodson's interest in the Sun began at Michigan, although her dissertation was, like so many Michigan dissertations of the era, on stellar spectroscopy, "A Study of the Spectrum of 25 Orionis." She came to Michigan during the establishment and growth of the solar observatory at Lake Angelus, the creation of three gifted and industrious amateurs. Heber Curtis fostered the growth of the McMath-Hulbert enterprise and brought it into the University. Dodson's solar activity grew as a result of a number of summers spent, during her Wellesley years, at the solar observatory at Meudon, near Paris. When she returned to Michigan, Dodson became involved in the study of solar flares, based upon the long series of daily observations made with the tower telescopes at Lake Angelus and the improved spectroscopic equipment developed by Robert McMath, Orren Mohler, Leo Goldberg, Keith Pierce, and others. Her colleague during most of these years was Emma Ruth Hedeman, who co-authored many articles with her. Among her grea